Siste publikasjoner

• Pederssen, Caroline Othilie Dedekam; Pham, Son Lam; Žugec, Paula; Homolak, Jan; Šutej, Ivana & Junges, Roger (2026). The impact of medical and dental education on student antimicrobial resistance literacy in Croatia. JAC-Antimicrobial Resistance (JAC-AMR). 8(4), s. 1–5. doi: 10.1093/jacamr/dlag183. Fulltekst i vitenarkiv
• Baker, Jonathon L.; Dahle, Ulf Reidar & Petersen, Fernanda Cristina (2026). mGem: Dentistry is strategically positioned yet underleveraged in the battle against antimicrobial resistance. mBio. ISSN 2161-2129. 17(9), s. e0064726–e0064726. doi: 10.1128/mbio.00647-26. Fulltekst i vitenarkiv
• Field, James; Vital, Sibylle; Murphy, Denis; Dixon, Jonathan; Kavadella, Argyro & Meisha, Dalia [Vis alle 34 forfattere av denne artikkelen] (2026). Exploring the Capabilities of a Graduating European Dentist: A Multistakeholder View. European journal of dental education. ISSN 1396-5883. doi: 10.1111/eje.70234. Fulltekst i vitenarkiv Vis sammendrag

  In 2026 the Association for Dental Education in Europe (ADEE) Graduating European Dentist (GED) taskforce held an international multi‐stakeholder event that explored opinions, perceived understanding, and clinical expectations around student progress and graduating student capabilities. This paper reports how the event was planned and conducted—and reports the opinions of the stakeholders relating to the importance of various clinical domains, evaluation/assessment metrics and markers when monitoring student progress and student capabilities.

• Rapp, Emma; Berset, Ingrid Prytz; Umu, Sinan Ugur; Bækkevold, Espen Sønderaal; Utheim, Karen Sivertsen & Dietrich, Alexander [Vis alle 13 forfattere av denne artikkelen] (2026). Longitudinal transcriptomic analysis of mucosa in ulcerative colitis after anti-tumor necrosis factor withdrawal compared to continued treatment. Journal of Crohn's and Colitis. ISSN 1873-9946. 20(8). doi: 10.1093/ecco-jcc/jjag121. Fulltekst i vitenarkiv Vis sammendrag

  Background and Aims Monoclonal antibodies against tumor necrosis factor (anti-TNF) are effective agents in the treatment of moderate-to-severe ulcerative colitis (UC). It is unclear whether such treatment can safely be discontinued without relapse. This study aimed to identify biomarkers to predict which patients can successfully stop anti-TNF treatment, and to increase our understanding of the pathogenesis of relapse after withdrawal and flare on continued therapy. Methods We analyzed longitudinal bulk RNA-sequencing data derived from rectal mucosal biopsies from 163 patients in the BIOSTOP study collected at baseline, after 2 years (end of study), and at flares or relapse points. Results In this cohort, pre-withdrawal transcriptomic profiles did not distinguish patients who later relapsed from those who remained in long-term remission. Longitudinal analysis of patients who relapsed or flared were both characterized by inflammatory gene expression profiles (eg, CXCL9, CXCL10, OSMR, SELE) and changes in cell-type composition typical for active UC (eg, monocytes/macrophages and THY1+ FAP+ PDPN+ activated fibroblasts). Both groups showed enrichment of T-cell-associated transcriptional signatures, including CD8 T-cell-related genes and IL-17-associated pathways. Additionally, both patient groups showed increased expression of targets of alternative therapeutic agents, suggesting potential treatment options for specific patient subgroups. Conclusions Our findings provide insights into the inflammatory mechanisms driving relapse after anti-TNF withdrawal and flare on continued treatment. The dataset offers a valuable resource for future research to improve personalized treatment strategies in UC.

• Giglio, Daniel; Ganesh, Divya; Bhattarai, Bishwa Prakash; Søland, Tine Merete; Sundberg, Jonas & Thorsell, Annika [Vis alle 9 forfattere av denne artikkelen] (2026). Biomarkers Correlating With the Development of Oral Squamous Cell Carcinoma From Leukoplakia. Oral Diseases. ISSN 1354-523X. doi: 10.1111/odi.70439. Fulltekst i vitenarkiv Vis sammendrag

  Background We assessed protein biomarkers expressed in oral leukoplakia (OL) that are associated with the risk of transformation into oral squamous cell carcinoma (OSCC). Methods Tissue sections of OL transforming into OSCC (leuko-ca), the corresponding OSCC and OL that did not progress to OSCC (leuko-nonca) were analyzed with global relative quantification to compare proteome profiles. Immunohistochemistry was performed to validate the expression of identified biomarkers. Results The top enriched biological pathways in OL transforming into OSCC within 5–26 months after diagnosis (short duration [SD]-leuko-ca) compared with leuko-nonca were pathways regulating remodeling of the extracellular matrix (ECM) and lipid and cholesterol metabolism/transport. Kininogen-1, apolipoprotein E (ApoE), collagen alpha-1 (XVIII) chain (COL18A1), sortilin, and perlecan were the most downregulated proteins, whereas EEF1D was the most upregulated in SD-leuko-ca compared with leuko-nonca. Immunohistochemistry confirmed the expression of kininogen-1, ApoE, perlecan, and EEF1D in OL and OSCC. In OSCC compared with leuko-ca, enriched biological pathways involved keratinocyte and epithelial differentiation and immune response regulation. Conclusion We identified biomarkers in OL that were associated with the risk of malignant transformation. Our study gives further support for the importance of the immune system, ECM remodeling, and lipoproteins and cholesterol metabolism in the progression of OL to OSCC.

• Sagen, Andreas Solberg; Shawrob, Kazi Shefaul Mulk; Salvadori, Gabriela & Junges, Roger (2026). Genetic and functional characterization of the natural transformation system in Streptococcus constellatus. Microbiology (Reading). ISSN 1350-0872. 172(6). doi: 10.1099/mic.0.001726. Fulltekst i vitenarkiv Vis sammendrag

  Streptococcus constellatus is an opportunistic pathogen frequently associated with abscess formation in various body sites. While the species has been shown to acquire exogenous DNA through natural transformation, functional analyses of its underlying mechanisms and optimized genetic editing protocols remain limited. Thus, our aim was to characterize the natural transformation system in S. constellatus and investigate environmental factors coordinating its activation. In addition, we sought to develop an optimized protocol for genome editing. Genomic analysis revealed that 73% of analyzed strains possess orthologs for essential competence regulon genes, with 58% harboring both a complete ComCDE-based operon and the putative transformation machinery required for natural competence. While all complete genomes harbored three copies of the master regulator sigX , the accessory regulator comW was seemingly absent. Lacking the peptide exporter comAB , we demonstrated that S. constellatus utilizes the bacteriocin transporter silED for competence-stimulating peptide export. Gene expression assays indicated system activation at peptide concentrations as low as 4 nM, with peak sigX expression obtained over 60 nM. With the goal of optimizing gene editing strategies, we developed a protocol utilizing rich media supplemented with BSA and calcium chloride, significantly increasing transformation frequencies. Furthermore, we observed that environmental stressors can upregulate the system, including hydrogen peroxide and subinhibitory concentrations of the antibiotics erythromycin, chloramphenicol and ampicillin. Given the increasing clinical relevance of the anginosus group, elucidating horizontal gene transfer mechanisms can provide critical insights into the evolutionary process and pathogenic potential of these species.

• Shawrob, K.S.M.; Sagen, A.S.; Lunde, Tracy Munthali; Sribasgaran, Biramitha; Ghafoor, Saba & Al-Haroni, M. [Vis alle 9 forfattere av denne artikkelen] (2026). Mapping Antibiotic Resistance Determinants in Oral Streptococci. Journal of Dental Research. ISSN 0022-0345. doi: 10.1177/00220345261462871. Fulltekst i vitenarkiv Vis sammendrag

  Antibiotic resistance is a global priority in health care. Leveraging thousands of whole-genome sequences, here we reveal the core resistance determinants of oral streptococci, focusing on assessing pattern variability and gene exchange across commensals and pathogens. Genomic information was obtained from the National Center for Biotechnology Information. Determinants of antibiotic resistance were identified using AMRFinderPlus and the Comprehensive Antibiotic Resistance Database. ICEscreen was employed for calling of integrative and conjugative elements. Variability and recombination in penicillin-binding protein sequences were assessed with MMseqs2 and fastGEAR. A total of 2,087 genomes from 15 species were included, representing the mitis, mutans, anginosus, salivarius, and bovis groups. We observed 3,576 hits from 55 unique resistance genes conferring resistance to 11 antibiotic classes. The species with the most resistance determinants per genome against unique antibiotic classes were Streptococcus mitis (2.7), Streptococcus oralis (2.5), Streptococcus parasanguinis (1.9), Streptococcus gallolyticus (1.3), and Streptococcus anginosus (1.2). The 2 latter species also presented the most diverse composition of determinants. Over 1,800 integrative and conjugative elements were predicted across all genomes, with nearly 17% carrying at least 1 antibiotic resistance gene. Penicillin-binding protein variation analyses showed a high diversity in the mitis group. Even though S. mitis and S. oralis composed less than 4% of the genomes included in the analyses, they were recognized as sources of DNA for over a third of recombination events in pbp1a and nearly half for both pbp2b and pbp2x in β-lactam-resistant isolates of Streptococcus pneumoniae . In summary, we show that tetracycline and macrolide resistance were highly abundant and tightly connected to integrative and conjugative elements. Further, recent recombination data in pbp loci show frequent genetic exchange from oral streptococci to β-lactam-resistant S. pneumoniae . Fundamentally, assessing triggers and the dynamics of genetic exchange across species is central to the development of strategies aiming to mitigate the impact of antibiotic resistance.

• Ganesh, Divya; Sundberg, Jonas; Dafar, Amal; Kjeller, Göran; Sapkota, Dipak & Öhman, Jenny [Vis alle 8 forfattere av denne artikkelen] (2026). Expression of intracellular toll-like receptors in leukoplakia and oral squamous cell carcinoma. Acta Odontologica Scandinavica. ISSN 0001-6357. 85, s. 96–103. doi: 10.2340/aos.v85.45423. Fulltekst i vitenarkiv Vis sammendrag

  Objective: Toll-like receptors (TLRs) are a group of pathogen recognition receptors expressed not only on immune cells but also cancer cells, where TLR activation may lead to tumour progression or suppression. At present, little is known about the role of TLRs and their connection with immune responses in precancerous lesions, such as oral leukoplakia (OL). In the present study, we have explored the immune activation and the expression of the intracellular TLRs – TLR3, TLR7, TLR8, and TLR9 in OL without and with dysplasia, and in oral squamous cell carcinoma (OSCC). Patients and methods: Immunohistochemistry was performed on 19 OL patients without dysplasia (OL-no) and 13 patients with dysplasia (OL-dys) and 10 OSCC patients. On digitalised images, TLR3-, TLR7-, TLR8- and TLR9-expressing cells were semi-quantitatively assessed, while the number of CD3- and CD8-expressing cells/mm2 was registered. Results: Nuclear TLR7 appeared in 31% of OL-dys but was absent in OL-no (p = 0.03). Cytoplasmic TLR8 was higher in OL-no than OL-dys (32% vs. 8%, p = 0.02). Similarly, cytoplasmic TLR9 was also higher OL-no than OL-dys (42% vs. 23%, p = 0.01). Conclusions: TLR3, TLR7, TLR8, and TLR9 are all expressed in OL-no, OL-dys, and OSCC. Also, the study provides evidence for possible nucleocytoplasmic shuttling of TLRs.

• Bhattarai, Bishwa Prakash; Singh, Ashutosh Kumar; Mastrogeorgiou, Michalis & Sapkota, Dipak (2026). Oral squamous cell carcinoma (OSCC): An overview. I Chaurasia, Akhilanand & Tavassoli, Mahvash (Red.), Microbiome in Head and Neck Cancer: Pathogenesis, Diagnosis and Therapeutic Implications: Part B. Elsevier. ISSN 9780443470561. s. 3–33. doi: 10.1016/bs.ai.2026.04.002. Fulltekst i vitenarkiv Vis sammendrag

  Oral cavity cancer comprises malignancies arising from anatomical sites within the oral cavity, including the gingiva, buccal mucosa, anterior two-thirds of the tongue (oral or mobile tongue), hard palate, floor of the mouth, retromolar area, and mucosal surface of the lip. More than 90% of oral cavity cancers are histologically squamous cell carcinomas (oral squamous cell carcinoma, OSCC). Combined with mucosal lip cancer, oral cavity cancer ranks as the 19th most common cancer globally, with approximately 390000 new cases and 190000 deaths annually. However, the burden of OSCC varies geographically, with Melanesia and South-Central Asia showing a much higher disease incidence. Despite advances in diagnostic and therapeutic approaches over recent decades, OSCC mortality has remained largely unchanged, with only approximately 55-60% of patients surviving 5 years after diagnosis. Tobacco use (both smoking and smokeless forms) and alcohol consumption are among the most important risk factors for OSCC. This book chapter aims to provide a general introduction to OSCC, including its epidemiology, associated etiological factors, a proposed model of molecular pathogenesis, the diagnostic pathway, common treatment modalities, and prognostic factors.

• Bhattarai, Bishwa Prakash; Singh, Ashutosh Kumar & Sapkota, Dipak (2026). Oral potentially malignant disorders (OPMDs): An overview. I Chaurasia, Akhilanand & Tavassoli, Mahvash (Red.), Microbiome in Head and Neck Cancer: Pathogenesis, Diagnosis and Pathogenesis, Diagnosis and Therapeutic Implications: Part A. Elsevier. ISSN 9780443470523. s. 175–191. doi: 10.1016/bs.ai.2026.03.003. Fulltekst i vitenarkiv
• Majewska, Marta; Bhatia, Anil; Maździarz, Mateusz A.; Lepiarczyk, Ewa; Lipka, Aleksandra Katarzyna & Wiszpolska, Marta [Vis alle 12 forfattere av denne artikkelen] (2026). Severity-dependent metabolic rewiring in COVID-19 based on untargeted metabolomic profiling of patient plasma. PLOS ONE. 21(6), s. 0352437–0352437. doi: 10.1371/journal.pone.0352437. Fulltekst i vitenarkiv Vis sammendrag

  Coronavirus disease 2019 (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), remains a major global health challenge, characterised by a heterogeneous clinical spectrum. While metabolomic studies have identified disruptions in amino acid, lipid, nucleotide, and energy metabolism during COVID-19, these investigations often lack fine-grained clinical stratification. In this study, we performed untargeted metabolomic profiling of plasma from 25 participants, including five healthy controls and twenty COVID-19 patients classified into four severity groups (COV1–COV4) based on pulmonary involvement and the need for respiratory support. Using ultra-performance liquid chromatography coupled with mass spectrometry (UPLC-MS), 541 metabolites were detected and analysed across all samples. Principal component analysis revealed a progressive metabolic divergence corresponding to disease severity. Monocarboxylic acid dysregulation was predominant in early to moderate cases (COV1–COV3), whereas severe disease (COV4) demonstrated a shift toward pyrimidine metabolism enrichment, consistent with heightened nucleotide turnover driven by viral replication and immune cell proliferation. Phenylalanine metabolism emerged as a consistently enriched pathway in COV1–COV3, suggesting aromatic amino acid perturbations as early markers of metabolic stress and immune activation. In contrast, pyrimidine pathway activation in COV4 could reflect profound systemic metabolic reprogramming associated with critical illness. These findings provide novel insights into COVID-19 pathophysiology, highlighting stage-specific metabolic signatures and potential biomarkers for disease monitoring. Our results support the concept of metabolomics-guided precision medicine, offering a rationale for targeted therapeutic interventions based on disease stage and metabolic phenotype.

• Palotie, Ulla; Liukkonen, Mikko; Lingström, Peter; Felszeghy, Szabolcs; Huhtela, Outi & Al-Haroni, Mohammed [Vis alle 57 forfattere av denne artikkelen] (2026). Reimagining Dental Education: Integrating Digital Technologies for a Global, Digitally Native Generation—A Perspective. European Journal of Dentistry. ISSN 1305-7456. doi: 10.1055/s-0046-1823144. Fulltekst i vitenarkiv Vis sammendrag

  Abstract Digital technologies, such as artificial intelligence (AI), virtual reality (VR), and haptic simulation, are rapidly reshaping oral health education. Traditional phantom head and clinic-based teaching remain essential but no longer suffice alone for digital-native learners or for regulators who increasingly view digital competence as mandatory. Post-COVID evidence suggests immersive and hybrid approaches can enhance motivation, deepen learning, support well-being, and strengthen clinical competence when thoughtfully embedded into curricula. Done well, this integration can foster safer, patient-centered digital care. Sustainability concerns around traditional, resource-intensive methods are also growing; digital tools can reduce material waste and resource use, aligning dental education with the United Nations 2030 Agenda for Sustainable Development. However, access to these innovations is uneven, raising concerns about a digital divide in graduate readiness and patient care. Networks such as the American Dental Education Association (ADEA), the Association for Dental Education in Europe (ADEE), the Haptic and AI Digital Education Network for Excellence and Research (HAiDENERS) show how collaboration and benchmarking can democratize advanced simulation. Together with active communication involving global research bodies and industry, these developments enable a hybrid, evidence-informed, and equitable training ecosystem whose ultimate goal is improved, safer, and more predictable oral health care worldwide.

• Brox, Julie Marie Haabeth; Tulek, Amela; Khan, Qalbi; Sehic, Amer; Stein, Linda & Breivik, Anne [Vis alle 8 forfattere av denne artikkelen] (2026). Erosive tooth wear – knowledge and treatment preferences among dental hygienists. Acta Odontologica Scandinavica. ISSN 0001-6357. 85, s. 332–341. doi: 10.2340/aos.v85.46261. Fulltekst i vitenarkiv Vis sammendrag

  Objective: Erosive tooth wear (ETW) is generally recognized as a widespread condition and a rising concern within the oral healthcare system. This study aimed to investigate dental hygienists` experiences and treatment methods regarding ETW in young adults. Material and methods: A questionnaire was sent to 1,084 Norwegian dental hygienists working in both public and private dental services. In total, 313 responded (response rate 28.9%). After excluding 47 respondents who did not meet the inclusion criteria of working with young adults (15–30 years), 266 dental hygienists were included in the final analyses (24.5% of those invited). Results: In total, 96% of the study population of 266 dental hygienists reported recording ETW in the register, with the public dental service doing so more frequently than the private sector. Sports drinks, energy drinks and soft drinks were believed to be the primary risk indicators of ETW, analogously across groups. Furthermore, there was consensus that the most frequently performed preventive measures were dietary guidance and self-administration of fluoride rinse and/or tablets. Conclusions: Overall, this study suggests that, in our sample, dental hygienists possess substantial knowledge of ETW and hold strong views on potential improvements in their work as healthcare professionals.

• Belhaj, Imen; Åmellem, Ingrid; Tartanoglu, Can H.; Weidemann, Hanne Margrete; Vallenari, Evan Michael & Yang, Mingyi [Vis alle 10 forfattere av denne artikkelen] (2026). Lactate treatment improves brain biochemistry and cognitive function in transgenic Alzheimer’s and wild-type mice. Scientific Reports. 16(1). doi: 10.1038/s41598-026-48154-6. Fulltekst i vitenarkiv Vis sammendrag

  Lactate, a well-known metabolite and signalling molecule, holds therapeutic potential for neurodegenerative diseases. Here, we investigated the effects of chronic lactate treatment on cognition and molecular biomarkers in the 5XFAD mouse model of Alzheimer’s disease (AD) and in wild-type (WT) controls using behavioural testing alongside proteomic and transcriptomic analyses. Mice received lactate or vehicle injections 4 days per week for 11 weeks, with behavioural testing before and after the treatment period. Lactate improved working memory in late-treated AD mice, without eliciting anxiety-like behaviour. At the molecular level, lactate reduced Il1b expression, and in a sex-dependent manner, normalised NEFL, and enhanced synaptic integrity proteins (OPCML, PPFIA2, STXBP3, SYT1, VGLUT2, VSNL1) in AD mice, while also augmenting mitochondrial regulators (ATP5G2, GRPEL1, SLC25A23) across genotypes. Notably, lactate upregulated low-abundance ionotropic glutamate receptor mRNAs (Grik3, Grin2c, Grid2ip) in female AD mice, indicating enhanced glutamatergic signalling. In WT mice, lactate increased expression of neurotrophic factors (Bdnf, Igf1, Vegfa), anti-inflammatory cytokines (Il4 and Il13), and the neuronal lactate transporter Mct2, suggesting promoted neuronal resilience. Together, these findings indicate that lactate treatment can mitigate cognitive decline and enhance molecular pathways of resilience in AD, warranting larger, age-stratified studies to validate its therapeutic potential and elucidate underlying mechanisms.

• Kudowa, Evaristar; Tembo, Godwin; Chirwa, Anthony E.; Chikaonda, Tarsizio; Muyaya, Alfred & Makhaza, Lumbani [Vis alle 93 forfattere av denne artikkelen] (2026). Pooled analysis of PCV13 efficacy from controlled human infection trials in Malawi and the UK. npj Vaccines. 11. doi: 10.1038/s41541-026-01381-4. Fulltekst i vitenarkiv Vis sammendrag

  We conducted the first pooled analysis of two randomised controlled vaccine trials on experimental pneumococcal serotype 6B carriage, registered in Malawi (PACTR202008503507113) and the UK (ISRCTN45340436). This post-hoc exploratory study examined the sex-based differences in carriage, vaccine efficacy and vaccine-induced responses. PCV-13 reduced colonisation by 76% (p < 0.001) with non-significant interaction by sex (RR = 1.549, p = 0.413). Females showed a higher carriage rate than males (28% vs. 19%, p = 0.066). Baseline anti-6B Capsular Polysaccharide Immunoglobulin G (IgG) titres were higher in females, significantly in Malawi (2.62 µg/ml vs males 2.05 µg/ml, p = 0.015). Post-vaccination titres did not differ by sex. The pooled fold change in IgG pre-post vaccination, was higher in vaccinated females (5.47 vs 3.30, p = 0.053). This analysis demonstrates the utility and challenges of integrating CHIM data between diverse settings to evaluate vaccine efficacy, describe inter-setting differences, investigate biological and immunological factors influencing protection against pneumococcal carriage and ultimately inform future vaccine development strategies.

• Pati, Niladri Bhusan; Chung, Brian K.; Holm, Kristian; Sætre, Frank Ove; Reims, Henrik Mikael & Aasebø, Anders Theodor Michaelsen [Vis alle 12 forfattere av denne artikkelen] (2026). Ultra long-lived plasma cells in the human small intestine produce microbiota-reactive IgA antibodies. Beneficial Microbes. ISSN 1876-2883. s. 1–13. doi: 10.1163/18762891-bja00120. Fulltekst i vitenarkiv
• Thune, Noora Helene; Kristensen, Anna Tostrup; Hammer, Hugo Lewi; Khan, Qalbi; Utheim, Tor Paaske & Sehic, Amer (2026). Evaluating digital resources as a supplement to traditional anatomy teaching in dental education. Frontiers in Dental Medicine. 7. doi: 10.3389/fdmed.2026.1781318. Fulltekst i vitenarkiv
• Umu, Sinan U.; Karlsen, Victoria T; Bækkevold, Espen Sønderaal; Jahnsen, Frode L. & Domanska, Diana (2026). Easydecon: Efficient Cell Type Mapping for High-Definition Spatial Transcriptomic Data. bioRxiv (preprint article). doi: 10.1101/2025.04.08.647764. Fulltekst i vitenarkiv Vis sammendrag

  The emergence of high-resolution spatial transcriptomics platforms, such as VisiumHD, has enabled transcriptome-wide spatial profiling at near-single-cell resolution. However, existing analysis tools often lack scalability or compatibility with this new resolution, limiting their utility for multimodal cell type analysis. We present Easydecon, a lightweight and modular computational framework for spatial transcriptomics analysis using marker genes from single-cell RNA sequencing datasets. Easydecon uses a two-phase strategy, which firstly detects expression hotspots and then refines cell type assignments with similarity-based methods. We demonstrate its efficacy by resolving cell type subsets with high accuracy. Easydecon supports integration with segmentation tools and outperforms established methods in speed, usability and cell type recovery.

• Kristensen, Anna Tostrup; Thune, Noora Helene; Hammer, Hugo Lewi; Khan, Qalbi; Utheim, Tor Paaske & Kristoffersen, Camilla Sofia Miranda [Vis alle 8 forfattere av denne artikkelen] (2026). From Images to Specimens: The Impact of Tactile, Three-Dimensional Learning in Dental Anatomy. Dentistry Journal. 14(4). doi: 10.3390/dj14040245. Fulltekst i vitenarkiv
• Yazdani, Mazyar; Fineide, Fredrik; Badian, Reza; Khan, Ayyad Ahmad Zartasht; Rootwelt, Helge & Kvaløy, Jan Terje [Vis alle 7 forfattere av denne artikkelen] (2026). Dry eye disease symptoms and associated risk factors in a Norwegian clinical cohort. Acta Ophthalmologica. ISSN 1755-375X. 00, s. 1–10. doi: 10.1111/aos.70143. Fulltekst i vitenarkiv Vis sammendrag

  Background The relationship between dry eye disease (DED) symptoms and different demographic, clinical and lifestyle factors remains poorly understood. Norway's cold climate and dry indoor air may accelerate tear evaporation, contributing to a very high meibomian gland dysfunction prevalence, as found in multiple studies. This suggests that environmental factors and age converge to drive evaporative dry eye as a near-universal finding in the Norwegian population. This study aimed to assess demographic, clinical and lifestyle correlates of DED symptoms, with a focus on sex-related differences and diurnal variation. Methods Between September 2021 and December 2023, 1044 individuals (303 males, 741 females) with symptoms of DED were enrolled at the Norwegian Dry Eye Clinic. All participants completed the Ocular Surface Disease Index (OSDI) and the Dry Eye Questionnaire-5 (DEQ-5) questionnaires, as well as an in-house, un-validated questionnaire. Clinical examinations and history-taking were conducted in a standardized manner by two experts. Associations between questionnaire scores and variables were analysed using Chi-squared tests, Kruskal–Wallis tests, Spearman correlations and logistic regression. Results Symptomatic DED above clinical cut-off levels was more prevalent in females than in males. Symptom severity was lowest in the late morning, and significant differences in both OSDI and DEQ5 scores were observed between individuals with and without reported omega-3 supplementation (with slightly higher scores in those taking omega-3). Allergies were associated with time-of-day symptom severity. Multivariable logistic regression revealed female sex, age below 65, not wearing contact lenses and refractive lens exchange surgery as significant risk factors for reporting more severe symptoms among the individuals in the database. Conclusions Severity of dry eye symptoms in this symptomatic, clinic-based population was significantly associated with several demographic and clinical factors. Incorporating standardized timing of assessments may enhance diagnostic accuracy in both research and clinical settings for DED.

• Golnarnik, Golnaz; Nieminen, Anni I.; Søland, Tine Merete; Galtung, Hilde & Haug, Trude M. (2026). Differential metabolic responses to hydrogen peroxide-induced oxidative stress in parotid and submandibular gland acinar cell lines. Biochemistry and Biophysics Reports. 46, s. 102596–102596. doi: 10.1016/j.bbrep.2026.102596. Fulltekst i vitenarkiv
• Quinn, Barry; Chau, Reinhard Chun Wang; Felszeghy, Szabolcs; Liukkonen, Mikko; Didilescu, Andreea Cristiana & Pasqualini, Damiano [Vis alle 29 forfattere av denne artikkelen] (2026). Immersive Technologies in Dental Education: Global Adoption Patterns From a 2025 Survey. Journal of Dental Education. ISSN 0022-0337. doi: 10.1002/jdd.70228. Fulltekst i vitenarkiv Vis sammendrag

  Purpose/Objectives Dental education is undergoing a digital transformation, yet the adoption of immersive technologies such as haptic virtual reality (HVR) remains limited. This study aimed to map global adoption trends, barriers, and opportunities for equitable integration of HVR in dental curricula. Methods A 73-item global survey (July–August 2025) was distributed to dental educators across 57 countries via professional networks and social media. The mixed-methods instrument, validated by experts, assessed simulation methods, usage, barriers, and perceptions. Descriptive and exploratory inferential statistics (e.g., one-way ANOVA, Kruskal–Wallis, and chi-square tests) were used to analyze quantitative data, while thematic analysis was used to analyze qualitative responses. Ethical approval was granted by a university ethics review board (No. 13/2023). Results Responses from 130 educators (115 institutions, 57 countries) showed traditional methods (phantom heads, n = 118; benchtop exercises, n = 84) dominating (∼80% clinical training time), while HVR (n = 42, primarily in undergraduate programs) and mixed reality (n = 14, primarily in undergraduate programs) were less prevalent, especially in postgraduate programs (10% HVR use). Barriers in implementing HVR simulators were mainly external, with a lack of resources (66.3%) and resistance from staff and students (21.3%), while personal barriers such as technological limits (9.0%), lack of training (2.2%), and lack of evidence (1.1%) were less common (total n = 89). Countries with higher socioeconomic status were found to use HVR more in undergraduate education than the less well-off countries (p = 0.002). Conclusion(s) Immersive technologies remain underutilized in dental education, particularly at the postgraduate level, creating potential gaps in clinical preparedness. Strategic integration, collaboration, and sustainability-focused adoption may enhance equity and clinical readiness, informing accreditation and policy reforms.

• Kristoffersen, Camilla Sofia Miranda; Ziesler, Camilla Elise Øxnevad; Thune, Noora Helene; Kristensen, Anna Tostrup; Utheim, Tor Paaske & Hammer, Hugo Lewi [Vis alle 9 forfattere av denne artikkelen] (2026). Histogenetics in Teaching the Complexity of Developmental Biology to Dental Students: A Study Merging Traditional and Current Approaches. Dentistry Journal. 14(3). doi: 10.3390/dj14030177. Fulltekst i vitenarkiv
• Afanou, Anani Komlavi; Sagen, Andreas Solberg; Barbero, Francesco; Zanoni, Ilaria; Costa, Anna & Haugen, Øyvind Pernell [Vis alle 7 forfattere av denne artikkelen] (2026). Microplastics amplify the pro-inflammatory response to fungal mycelial fragments and spores in neutrophil-like cells. Frontiers in Toxicology. 8. doi: 10.3389/ftox.2026.1718466. Fulltekst i vitenarkiv Vis sammendrag

  Microplastic pollution has emerged as a global environmental crisis with potential adverse consequences on human health. Mixtures of microplastics with fungal particles including mycelial fragments or spores are highly probable exposure scenarios occurring in various occupational settings or in moldy built indoor environments. However, immunotoxic outcomes associated with such exposure remain poorly characterized. Most studies have focused on single‐exposure components. Here, we investigated, for the first time, the immunotoxic effects of microplastics mixed with spores or mycelial fragments from Aspergillus fumigatus on human neutrophil-like cells. Differentiated HL60 neutrophil-like cells were exposed to 0–100 μg/mL HDPE microplastics mixed with 10 6 heat-inactivated mycelial fragments or spores for 24 h. HDPE combined with fungal fragments induced significant release of IL‐6 and IL‐8 while the mixtures with fungal spores induced only IL‐6 release from the neutrophil-like cells. Most importantly, we observed a trend of decreasing IL‐6 levels with increasing doses of HDPE microplastics in mixture with fungal particles, indicating possible dysregulation of the pro-inflammatory response. The tested doses of HDPE microplastics in mixture with fungal particles showed no significant acute effects on the cell viability. Using HEK293‐TLR reporter cells, we found no significant activation of TLR2 and TLR4 by HDPE microplastics, fungal particles, or their combination, suggesting that the release of IL‐6 and IL‐8 is induced through other innate immune-signaling pathways. Taken together, fungal particles as microbial contaminants, seem to be the main drivers of the immune responses triggered by exposure to mixed HDPE microplastics and fungal particles. Among these, fungal mycelial fragments appear to be the most potent compared to fungal spores that are typically monitored for risk assessments.

• Kristensen, Anna Tostrup; Thune, Noora Helene; Khan, Qalbi; Utheim, Tor Paaske; Hammer, Hugo Lewi & Sehic, Amer (2026). Student perspectives on integrating basic and clinical dental sciences: insights from three dental schools in Norway. Frontiers in Dental Medicine. 7. doi: 10.3389/fdmed.2026.1746468. Fulltekst i vitenarkiv
• Karlsen, Victoria T.; Majid, Umair; Lindholm, Håvard T.; Umu, Sinan U.; Vander-Elst, Karoline Rapp & Beitnes, Ann-Christin Røberg [Vis alle 13 forfattere av denne artikkelen] (2025). Single cell spatial transcriptomics identifies coordinated cellular programs associated with good prognosis in microsatellite stable colorectal cancer. bioRxiv (preprint article). doi: 10.1101/2025.03.31.646286. Fulltekst i vitenarkiv Vis sammendrag

  ABSTRACT It has been reported that microsatellite instable (MSI) tumors in colorectal cancer (CRC) exhibit stronger anti-tumor responses than microsatellite stable (MSS) tumors. Analyzing scRNA-seq data from 185 CRC patients we found that immune, structural, and cancer cells in MSS tumors with high numbers of tumor-infiltrating CD8 T cells and macrophages (TAMs; CD8 hi TAM hi ) and CD8 low TAM hi tumors were enriched for pathways associated with anti- and pro-tumor responses, respectively. In CD8 hi TAM hi tumors, TAMs expressed an IFN-induced phenotype (e.g. GBP1, CXCL9, IFITM3 ) and high infiltration of GBP1 + TAMs was associated with better overall survival (n=941). High-resolution spatial transcriptomics (Visium HD) revealed that GBP1 + TAMs clustered with CXCL13 + IFNG+PDCD1+ CD8 T cells in tumoral niches, suggesting that GBP1 + TAMs were involved in recruitment and activation of tumor-reactive CD8 T cells. Together, we uncovered coordinated cellular programs across cell types in the microenvironment of MSS tumors, based on simple classification variables, that were strongly associated with prognosis.

• Rued, Britta E.; Dhariwal, Achal; Covington, Brett C.; Seyedsayamdost, Mohammad R.; Krivograd, Sophie A. & Pesavento, Russell P. [Vis alle 8 forfattere av denne artikkelen] (2025). Impact of the RaS-RiPP tryglysin and culturing conditions on ex-vivo oral microbiomes. npj Biofilms and Microbiomes. 11(1). doi: 10.1038/s41522-025-00794-8. Fulltekst i vitenarkiv Vis sammendrag

  Abstract Natural products are ubiquitously produced by many species that we encounter during our daily lives. One genus, Streptococcus , can produce a wide array of quorum sensing linked natural products known as RaS-RiPPs (ribosomally synthesized and post-translationally modified peptides). Their production is triggered by the induction of an Rgg-SHP quorum sensing system, which senses the presence of SHPs (short hydrophobic peptides) and induces the gene expression of these operons. Previous work has found that streptococcal RaS-RiPPs modulate the growth of different streptococci and might play a role in antibiotic tolerance. This is of particular importance to the oral microbiome, where streptococci are a predominant genus. This study provides the first report on attempts to study the impact of the RaS-RiPP Tryglysin A on ex-vivo oral systems and explores important factors to consider when culturing these systems. We explore how medium selection, atmosphere, growth model, and saliva amount can impact the presence of both bacterial and fungal species. These studies provide the groundwork for determining how RaS-RiPP producing Streptococci might impact the composition and function of oral microbiome communities, as well as important aspects to consider when culturing ex-vivo oral systems.

• Ai, Ruixue; Mao, Lipeng; Jin, Xurui; Campos-Marques, Carlos; Zhang, Shi-qi & Pan, Junping [Vis alle 33 forfattere av denne artikkelen] (2025). NAD+ reverses Alzheimer’s neurological deficits via regulating differential alternative RNA splicing of EVA1C. Science Advances. 11(45). doi: 10.1126/sciadv.ady9811. Fulltekst i vitenarkiv Vis sammendrag

  Dysfunctional alternative splicing events (ASEs) in RNA are markers of aging and Alzheimer’s disease (AD). As a key neuronal resilience metabolite, the oxidized nicotinamide adenine dinucleotide (NAD+) slows down AD progression in preclinical studies with several clinical trials ongoing. However, the underlying molecular mechanisms around how NAD+ enhances neuronal resilience, especially whether it has any effect on ASEs, have remained elusive. This study shows that NAD+ augmentation corrects the ASEs of many genes via a key protein, EVA1C (epithelial V-like antigen 1 homolog C), which is involved in neuronal development and activities. EVA1C is reduced in the hippocampus in patients with AD compared to cognitively normal ones. NAD+-induced memory retention is partially dependent on EVA1C, as adeno-associated virus–based Eva1c knockdown in the hippocampal CA1 region annuls NAD+-induced memory improvement in pathological Tau–bearing mice. We propose that NAD+ reduces AD pathologies, at least partially, via amplification of the NAD+-EVA1C splicing axis, pointing to a potential splice-switching therapy for AD.

• Kennedy, Lauritz Hagen; Morland, Cecilie; Narum, Martine; Bergersen, Linda Hildegard & Rinholm, Johanne Egge (2025). Lactate Receptor HCAR1 Affects Axonal Development and Contributes to Lactate’s Protection of Axons and Myelin in Experimental Neonatal Hypoglycemia. eNeuro. 12(5). doi: 10.1523/eneuro.0563-24.2025. Fulltekst i vitenarkiv Vis sammendrag

  Lactate plays an important role in brain energy metabolism. It contributes to normal brain development and to neuroprotection in diabetic hypoglycemia, but its role in neonatal hypoglycemia is unclear. Moreover, lactate can work as a signaling substance via the lactate receptor HCAR1 (Hydroxycarboxylic acid receptor 1). Recent studies indicate that HCAR1 is protective in mouse models of neonatal hypoxic ischemia and has a role in metabolic regulation in glial cells during hypoglycemia. Here we have studied potential impacts of HCAR1 on axonal and myelin development in the cerebral cortex and corpus callosum of young (P21) wild-type (WT) mice and HCAR1 KO mice and in cortical organotypic brain slice cultures. The HCAR1 KO mice showed lower axonal area relative to WT in both cortex and corpus callosum. However, the myelin area was unaffected by HCAR1 KO. Using particle and colocalization analysis, we show that HCAR1 KO predominantly reduces axonal size in unmyelinated axons. Using an organotypic brain slice model of neonatal hypoglycemia, we find that lactate protects both axonal and myelin development in hypoglycemia, partially via HCAR1. Lastly, live imaging with a pH-sensitive dye on acute cortical brain slices indicates that cellular lactate uptake is influenced by HCAR1. In conclusion, our findings support a role of HCAR1 in axonal development and in lactate’s protective effects in hypoglycemia.

• Osman, Tarig Al-Hadi; Rikardsen, Oddveig Gjertrud; Teh, Muy-Teck; Sapkota, Dipak; Liang, Xiao & Neppelberg, Evelyn [Vis alle 11 forfattere av denne artikkelen] (2025). Identification of Phenotypically Distinct Cancer Stem Cell Subpopulations in Oral Squamous Cell Carcinoma. Cancers. 17. doi: 10.3390/cancers17213547. Fulltekst i vitenarkiv Vis sammendrag

  Background: Several markers have been shown to define subpopulations enriched for cancer stem cells (CSCs) and correlate with poor clinical outcomes in oral squamous cell carcinoma (OSCC). Objective: To investigate the pattern of expression and correlation with clinical parameters of two CSC markers, namely p75NTR and ALDH1A1, in both patient samples and cell lines. Methods: Archival formalin-fixed paraffin-embedded samples from normal human oral mucosa (NHOM, n = 31), oral dysplasia (OD, n = 10) and OSCC (n = 177) were subjected to multiple immunohistochemistry and some to qRT-PCR for expression of CSC and proliferation-related markers, BMI1 and Ki67. Correlations between CSC marker expression and clinical parameters were investigated. Primary cells and cell lines derived from NHOM, OD or OSCC were FACS-analyzed for the same markers. Results: A higher frequency of cells positive for CSC markers was detected in OD and OSCC compared to NHOM. Co-localization of the two markers was a rare finding in OSCC as compared to NHOM or OD and was more heterogeneous in OSCC cell lines than in OD and NHOM cells. Cells positive for p75NTR exhibited higher expression of proliferative and self-renewal markers in comparison to ALDH1A1+ or double ALDH1A1+/p75NTR+ cells. Cells positive for p75NTR were more frequent in small-size tumors and poorly to moderately differentiated tumors and correlated with poor survival of patients otherwise (clinically) deemed as of better prognosis. Higher frequency of ALDH1A1+ cells was found to be associated with lymph node metastasis. Both p75NTR+ cells and ALDH1A1+ cells could emerge de novo from the respective negative subpopulation after FACS and in vitro growth, but with different kinetics. Conclusions: Here, we show that several stem cell subpopulations with distinct phenotypes co-exist in a tumor, each having impact on different clinical parameters. The cell subpopulations identified by the use of different CSC markers were found to be dynamic populations, able to switch between phenotypes. In addition, our data suggest that the stem cell heterogeneity is acquired and evolves parallel with carcinoma progression.

• Thune, Noora Helene; Kristensen, Anna Tostrup; Khan, Qalbi; Utheim, Tor Paaske; Hammer, Hugo Lewi & Sehic, Amer (2025). Retention of skull anatomy knowledge in dental education: a comparative study. Frontiers in Dental Medicine. 6, s. 1–9. doi: 10.3389/fdmed.2025.1596610. Fulltekst i vitenarkiv Vis sammendrag

  There is limited evidence regarding the retention of essential basic science knowledge among dental students and professionals. Understanding the anatomy of the skull, osteology, is crucial as it provides the structural framework essential for comprehending head anatomy, where various soft tissue components are organized. This study aims to evaluate and compare the retention of osteological knowledge across different stages of dental education and professional practice. Specific anatomical structures on selected skull bones and the complete cranium, taught at the pre-clinical level and including clinically and radiographically significant landmarks, were marked for assessment. The study evaluated the ability of second year and f ifth year undergraduate dental students, as well as postgraduate students at various stages of specialist training in different dental fields, to independently identify these marked anatomical structures. The study demonstrated significantly higher identification accuracy among second year students compared to fifth year and postgraduate students (p<0.05). Second year students achieved over 90% accuracy for individual skull bones, with slightly lower accuracy for the entire cranium (85.9%). Fifth year students showed markedly lower retention, with accuracy below 50%, ranging from 20.8% (cranium) to 48.3% (mandible). Postgraduate students performed similarly to f ifth year students, notably with only 11.8% accuracy for the sphenoid bone. Significant differences in accuracy were observed among postgraduate specialties (p <0.05), with oral surgery and oral medicine specialists achieving the highest accuracy (81.2% for the mandible). However, no significant correlation between years of experience and accuracy was observed among the postgraduate groups (p=0.45). Our results indicate that clinically and radiologically relevant anatomical knowledge is better retained over time, while overall osteological knowledge significantly declines. This highlights the need for strategies beyond initial learning to enhance long-term retention. Integrating clinical, radiological, and surface anatomy into continuing dental education could substantially improve knowledge retention. Furthermore, our f indings suggest potential benefits from increased vertical integration and encourage broader discussion regarding the traditional separation between pre-clinical and clinical training phases.

• Søland, Tine Merete; Ljunggren, A; Abuharb, A; Alaref, F; Kelppe, J & Reibel, J [Vis alle 14 forfattere av denne artikkelen] (2025). Odontogenic tumors in Sweden, Norway, Finland, and Denmark. A multicenter study. Journal of Oral Pathology & Medicine. ISSN 0904-2512. 54(5), s. 360–370. doi: 10.1111/jop.13635. Fulltekst i vitenarkiv Vis sammendrag

  Background Updated and comprehensive epidemiological data on odontogenic tumors are not available for the Nordic countries. The aim of the study was to retrospectively examine the prevalence and clinical and radiological characteristics of primary odontogenic tumors over a 10-year period in Sweden, Norway, Finland, and Denmark. Methods Primary odontogenic tumors diagnosed by oral pathologists from 2010 to 2020 at nine different diagnostic laboratories in Sweden, Norway, Finland, and Denmark were identified. Using histopathology referrals and their corresponding histopathological reports, age and sex, anatomic site, clinical and radiological findings, tentative diagnosis, histopathological diagnosis, and recurrence of the tumors were recorded. Range, mean, and median for continuous variables and frequency tabulation for discrete variables were used. Results In total, 1139 primary odontogenic tumors (598 in males and 540 in females) were identified during the study period, giving an annual incidence rate of 4.2/million. The mean age of all patients was 29 years. Ninety-nine percent of the tumors were benign, and the mandible was the predominant location. Odontoma, ameloblastoma, and odontogenic fibroma were the three most common tumors. The mixed epithelial and mesenchymal benign odontogenic tumors were more common at a younger age compared with the epithelial tumors and the mesenchymal tumors (mean age 22, 44, and 35 years, respectively). Information on variables other than sex, age, and tumor site was missing in most referrals. Conclusion The annual incidence of 4.2 cases per million indicates that odontogenic tumors are uncommon in Nordic countries. Better practices to improve the quantity and quality of clinical information in the pathology referrals are needed.

• Juvkam, Inga; Zlygosteva, Olga; Schreurs, Olaf Joseph Franciscus; Edin, Nina Frederike Jeppesen; Galtung, Hilde & Malinen, Eirik [Vis alle 7 forfattere av denne artikkelen] (2025). Regional atrophy, cellular plasticity, and regenerative potential in irradiated murine salivary glands. Acta Oncologica. ISSN 0284-186X. 64, s. 927–938. doi: 10.2340/1651-226x.2025.44012. Fulltekst i vitenarkiv Vis sammendrag

  Background and purpose: Radiotherapy of head and neck cancer may cause detrimental late side effects such as fibrosis and hyposalivation. We investigated mouse salivary glands after fractionated irradiation, with the aim to elucidate cellular plasticity and potential regeneration. Methods: 12-week-old female C57BL/6JRj mice were irradiated with X-rays to a total dose of 66 Gy, given in 10 fractions over 5 days. The radiation field covered the oral cavity and major salivary glands. The submandibular (SMG), sublingual (SLG), and parotid glands (PG) were dissected at day 100 after finishing irradiation. Using different histological staining techniques, morphological, cellular, and molecular changes were investigated in irradiated and control SMG, SLG, and PG. Results: Atrophy of acinar cells was observed in irradiated SMG and SLG, but not in PG. Surprisingly, the acinar atrophy was confined to one region of each irradiated gland. These atrophic regions showed distinct cellular and molecular compositions compared to non-atrophic regions and control glands. Increased expression of the ductal cell markers keratin 5 and 19 (K5 and K19), along with increased percentages of proliferating myofibroblasts, fibroblasts, leukocytes, and acinar cells (Nkcc1+) were observed in the atrophic regions compared to controls. In addition, some of the K19+ and K5+ duct-like cells also co-expressed Nkcc1. Interpretation: Through a detailed histological assessment of the cellular and molecular changes in the major salivary glands of irradiated mice, we observed signs of cellular plasticity where ductal cells adopt an acinar cell phenotype upon irradiation. This suggests a regenerative potential of salivary glands after irradiation.

• Haugsten, Helene Rygvold; Kristoffersen, Anne Karin; Enersen, Morten; Thiede, Bernd; Søland, Tine Merete & Haug, Trude M. [Vis alle 7 forfattere av denne artikkelen] (2025). Bacterial extracellular vesicles from Porphyromonas gingivalis – proteomic profile and influence on oral fibroblasts. Archives of Oral Biology. ISSN 0003-9969. 181. doi: 10.1016/j.archoralbio.2025.106424. Fulltekst i vitenarkiv Vis sammendrag

  Objectives In this study, we aimed to explore the protein content of bacterial extracellular vesicles (bEVs) from three strains of Porphyromonas gingivalis, an anaerobic gram-negative bacterium closely associated with periodontitis. Additionally, we aimed to investigate the effects of bEV uptake on human oral fibroblasts, to better understand the role of these vesicles in the pathogenesis of periodontitis. Design Liquid chromatography-mass spectrometry was performed on bEVs from three strains of P. gingivalis with different virulence: ATCC 33277, A7A1–28, and W83. Three key proteins associated with virulence were validated using dot blot. Proliferation and viability of human oral fibroblasts after incubation with bEVs were assessed at different timepoints and different concentrations of bEVs. Results A total of 307 proteins were identified in the bEVs from the three strains of P. gingivalis. Among those were several relevant for virulence, for example gingipains, fimbriae, and peptidyl-arginine deiminase (PPAD). When oral fibroblasts were exposed to bEVs from A7A1–28 or W83, proliferation was significantly affected after 12 and 24 h at one bEV concentration. Furthermore, viability was significantly affected by bEVs from W83 at several timepoints and bEV concentrations. bEVs from ATCC 33277 did not induce any significant changes. Conclusion Several proteins associated with virulence were detected in bEVs from all three strains of P. gingivalis, with varying abundance. Uptake of these bEVs can influence human cells, as exemplified by changes in viability and proliferation.

• Haugsten, Helene Rygvold; Lipka, Aleksandra Katarzyna; Kristoffersen, Anne Karin; Enersen, Morten; Nieminen, Anni & Søland, Tine Merete [Vis alle 8 forfattere av denne artikkelen] (2025). Metabolic Changes in Oral Fibroblasts After Exposure to Bacterial Extracellular Vesicles From Three Strains of Porphyromonas gingivalis. Cellular Microbiology. ISSN 1462-5814. 2025(1). doi: 10.1155/cmi/7515004. Fulltekst i vitenarkiv Vis sammendrag

  Aims Porphyromonas gingivalis is a keystone pathogen in periodontitis that releases bacterial extracellular vesicles (bEVs) with a content derived from the membrane and cytosol of the bacteria itself. The bEVs are taken up by host tissue cells, such as oral fibroblasts, yet their effects on human cells remain incompletely understood. Methods The aim of this study was to investigate the impact of bEVs on human oral fibroblasts. Targeted liquid chromatography–mass spectrometry was used to assess changes in the metabolome of these cells following exposure to bEVs from three strains of P. gingivalis (ATCC 33277, A7A1-28, and W83). Metabolite content of the bEVs from each strain was also characterized. Result Metabolomic analyses revealed both common and strain-specific metabolites in the bEVs from these strains. Additionally, pathways mainly associated with amino acid metabolism were enriched for all. Following exposure to bEVs, the fibroblasts exhibited a metabolic shift in energy metabolism. In particular, fibroblasts incubated with bEVs from ATCC 33277 had a unique profile of enriched pathways after 10 min. However, after 24 h, this profile changed and became more similar to the profile in fibroblasts incubated with bEVs from the two more pathogenic strains. Pathway analysis revealed enrichment of glycerophospholipid and butanoate metabolism for fibroblasts exposed to all the bEVs. Additionally, altered sphingolipid metabolism was observed in fibroblasts following exposure to bEVs from ATCC 33277. Conclusion Our findings demonstrate that bEVs derived from P. gingivalis strains can induce changes in cellular processes in fibroblasts. This suggests a role of bEVs in the pathogenesis of periodontitis.

• Tansirichaiya, Supathep; Songsomboon, Kittikun; Wigand, Johannes; Winje, Endre; Chaianant, Nichamon & Leartsiwawinyu, Wasawat [Vis alle 7 forfattere av denne artikkelen] (2025). Geographic signatures in the oral resistome: a comparative metagenomic analysis of healthy individuals from Thailand and Norway. Journal of Oral Microbiology. 17(1). doi: 10.1080/20002297.2025.2589656. Fulltekst i vitenarkiv Vis sammendrag

  Background The oral cavity is an important yet understudied reservoir of antimicrobial resistance genes (ARGs), potentially shaped by geographic variation in antibiotic usage. Objective To compare the oral resistomes of healthy adults from Thailand and Norway, two countries with contrasting antimicrobial use practices, using shotgun metagenomic sequencing. Design Stimulated saliva samples were collected from healthy adults in Thailand (n = 43) and Norway (n = 50). ARGs were identified with AMRPlusPlus against the MEGARes database, and microbial taxonomy was profiled with KrakenUniq. Diversity metrics, ordination, and clustering analyses assessed resistome and microbiome structures. Results Thai samples exhibited significantly greater ARG richness, evenness, and diversity (p < 0.001), driven by higher abundances of multi-biocide, nucleoside, and copper resistance genes. Norwegian samples were enriched in aminoglycoside, sulfonamide, and quaternary ammonium compound resistance genes. Both cohorts shared core oral genera, but Thai samples showed greater taxonomic richness without differences in overall microbiome diversity. Non-metric multidimensional scaling and PERMANOVA revealed stronger geographic separation for resistomes (R² = 0.639) than microbiomes (R² = 0.382). Co-occurrence networks highlighted structured associations between ARG groups and bacterial genera, suggesting ecological influences beyond taxonomic composition. Conclusions These results reveal distinct geographic signatures in the oral resistome that are not fully explained by microbiome structure, reflecting the influence of local ecological and societal factors, including antimicrobial exposure. The findings highlight the oral cavity as a dynamic ARG reservoir and support its inclusion in regional antimicrobial resistance surveillance to inform public health strategies.

• Vevik, Kristina; Sribasgaran, Biramitha; Cai, Kun; Naemi, Ali-Oddin; Kaspersen, Håkon & Uhlig, Silvio [Vis alle 8 forfattere av denne artikkelen] (2025). TrkA of Streptococcus mitis CCUG31611 binds cyclic di-adenosine monophosphate and is required for growth in low potassium conditions. Microbiology (Reading). ISSN 1350-0872. 171(8). doi: 10.1099/mic.0.001597. Fulltekst i vitenarkiv Vis sammendrag

  Cyclic di-adenosine monophosphate (c-di-AMP) is a bacterial second messenger regulating many physiological processes in bacteria. In the oral commensal species Streptococcus mitis, c-di-AMP is involved in regulating metabolism, growth, colony morphology, chain length, biofilm formation and DNA stress tolerance. However, no c-di-AMP-regulated effector proteins have yet been characterized in S. mitis. In this study, we first show that a ΔcdaA mutant, unable to produce c-di-AMP, grows slowly under low environmental potassium conditions. Growth of the cdaA mutant was not restored by reintroducing cdaA in the original locus (KBcdaA). Whole-genome sequencing of multiple KBcdaA isolates revealed secondary mutations in a putative potassium transporter. The mutations were predicted to result in the truncation of the protein or the alteration of a conserved glycine residue essential for selective potassium uptake, disrupting protein function. A Δpde2 mutant overproducing c-di-AMP survived poorly under high environmental sodium concentrations. We then characterized the potassium transporter regulator protein TrkA. Biochemical analyses of the purified recombinant TrkA protein revealed that it specifically binds c-di-AMP with high affinity in vitro. Using deletion mutants of trkA, we demonstrate that TrkA is essential for growth under low environmental potassium conditions. Ultra-high-performance liquid chromatography coupled to tandem mass spectrometry revealed lower c-di-AMP concentration in the ΔtrkA mutant compared to the WT. This was not due to transcriptional regulation of the expression of the c-di-AMP turnover proteins CdaA, Pde1 or Pde2. C-di-AMP production is not affected by the extracellular potassium concentrations under the conditions tested. We also demonstrate a potential role of TrkA in UV stress tolerance but do not characterize the mechanism in this study.

• Breivik, Anne; Kopperud, Simen E.; Mulic, Aida Gacic; Stein, Linda; Yitayew, Teferi Mekonnen & Hadler-Olsen, Elin Synnøve [Vis alle 7 forfattere av denne artikkelen] (2025). Risk Indicators Associated with Root Caries and Oral Health-Related Quality of Life among Older Adults: The Tromsø7 Study. Caries Research. ISSN 0008-6568. s. 13–13. doi: 10.1159/000547745. Fulltekst i vitenarkiv Vis sammendrag

  Introduction: This study aimed to investigate risk indicators associated with root caries in older adults aged 65 years and above in Norway. A secondary aim was to explore whether root caries was associated with oral health-related quality of life (OHRQoL). Methods: This cross-sectional study included 1,075 participants aged ≥65 from the population-based Tromsø Study (Tromsø7) conducted in Northern Norway in 2015–2016. All inhabitants aged 40 years and older in Tromsø municipality (32,591) were invited, of whom 21,083 participated. The participants underwent clinical and radiographic examinations and answered extensive questionnaires. Root caries was registered on four surfaces per tooth and graded D_3-5. For analysis, prevalence of root caries was dichotomised into (1) no (if the participants had no root caries) and (2) yes (if root caries was registered on at least one surface). Characteristics of the study population were described with percentages and frequencies for the categorical variables and mean and standard deviation (SD) for continuous variables for the whole cohort and stratified on presence of root caries and OHRQoL impact. The statistical significance of differences was assessed with the Pearson χ2 test and independent sample T test. Factors associated with root caries and OHRQoL were explored using logistic regression. The significance level was set to p < 0.05 for all analysis. Results: Men had higher odds of root caries than women (OR: 1.70, 95% CI [1.08, 2.70]) and those who were smokers had a higher odds of root caries than those who had never smoked (OR: 1.83, 95% CI [1.13, 2.94]). Participants with root caries had 1.67 times higher odds of having reduced OHRQoL than those without root caries (95% CI: 1.02, 2.72). Conclusion: This study found that being male and smoking were risk indicators of root caries. Additionally, root caries had a negative impact on OHRQoL. The results could be useful for oral health professionals to guide individual and targeted root caries preventive measures in older adults.

• Huynh, Bao Ngoc; Kakar, Manish; Zlygosteva, Olga; Juvkam, Inga; Edin, Nina Frederike Jeppesen & Tomic, Oliver [Vis alle 8 forfattere av denne artikkelen] (2025). CNN-based prediction using early post-radiotherapy MRI as a proxy for toxicity in the murine head and neck. Acta Oncologica. ISSN 0284-186X. 64, s. 1312–1320. doi: 10.2340/1651-226X.2025.44020. Fulltekst i vitenarkiv Vis sammendrag

  Background and purpose: Radiotherapy (RT) of head and neck cancer can cause severe toxicities. Early identification of individuals at risk could enable personalized treatment. This study evaluated whether convolutional neural networks (CNNs) applied to Magnetic Resonance (MR) images acquired early after irradiation can predict radiation-induced tissue changes associated with toxicity in mice. Patient/material and methods: Twenty-nine C57BL/6JRj mice were included (irradiated: n = 14; control: n = 15). Irradiated mice received 65 Gy of fractionated RT to the oral cavity, swallowing muscles and salivary glands. T2-weighted MR images were acquired 3–5 days post-irradiation. CNN models (VGG, MobileNet, ResNet, EfficientNet) were trained to classify sagittal slices as irradiated or control (n = 586 slices). Predicted class probabilities were correlated with five toxicity endpoints assessed 8–105 days post-irradiation. Model explainability was assessed with VarGrad heatmaps, to verify that predictions relied on clinically relevant image regions. Results: The best-performing model (EfficientNet B3) achieved 83% slice-level accuracy (ACC) and correctly classified 28 of 29 mice. Higher predicted probabilities of the irradiated class were strongly associated with oral mucositis, dermatitis, reduced saliva production, late submandibular gland fibrosis and atrophy of salivary gland acinar cells. Explainability heatmaps confirmed that CNNs focused on irradiated regions. Interpretation: The high CNN classification ACC, the regions highlighted by the explainability analysis and the strong correlations between model predictions and toxicity suggest that CNNs, together with post-irradiation magnetic resonance imaging, may identify individuals at risk of developing toxicity.

• Farooq, Samiya; Talat, Absar; Dhariwal, Achal; Petersen, Fernanda Cristina & Khan, Asad U. (2025). Transgenerational gut dysbiosis: Unveiling the dynamics of antibiotic resistance through mobile genetic elements from mothers to infants. International Journal of Antimicrobial Agents. ISSN 0924-8579. 65(5). doi: 10.1016/j.ijantimicag.2025.107458. Fulltekst i vitenarkiv
• Rotta, Isadora dos Santos; Bitencourt, Fernando Valentim; Collares, Fabrício Mezzomo; Junges, Roger; Samuel, Susana Maria Werner & Toassi, Ramona Fernanda Ceriotti [Vis alle 7 forfattere av denne artikkelen] (2025). Monitoring career impact and satisfaction in a graduate program in dentistry. Frontiers in Dental Medicine. 6. doi: 10.3389/fdmed.2025.1566272. Fulltekst i vitenarkiv
• Lipka, Aleksandra; Søland, Tine Merete; Nieminen, Anni I.; Sapkota, Dipak; Haug, Trude Marie & Galtung, Hilde (2025). The effect of extracellular vesicles derived from oral squamous cell carcinoma on the metabolic profile of oral fibroblasts. Frontiers in Molecular Biosciences. 12. doi: 10.3389/fmolb.2025.1492282. Fulltekst i vitenarkiv Vis sammendrag

  Introduction: Oral cancer is one of the most common forms of head and neck cancers. Oral squamous cell carcinoma (OSCC) accounts for more than 90% of the oral malignancies. The molecular pathogenesis of OSCC is complex as it involves altered expression of specific genes and proteins, but also comprises changes in metabolic processes. It is suggested that extracellular vesicles (EVs) released by cancer cells may contribute to cancer development and metastasis by recruiting and changing phenotype of normal cells that surround the tumor. Methods: The aim of the project was to characterize the effect of OSCC EVs on the metabolic profile of normal oral fibroblasts (NOFs). Targeted liquid chromatography mass spectrometry metabolic profiling was performed on control cells and NOFs exposed to OSCC EVs for 24 and 48 h. Results: Analysis of detected metabolites revealed that OSCC EVs affected NOFs the most after 24 h of exposure. Among metabolites that were significantly altered at 24 h, pyruvate, ATP, UTP, coenzyme A, and dihydroxyacetone phosphate were upregulated, while fatty acids such as nervonic acid, linoleate, oleate, palmitoleic acid, and docosahexaenoic acid were downregulated. These findings were supported by Western blotting of pyruvate kinase M2 (PKM2) and aldolase, fructose-bisphosphate A (ALDOA). Conclusion: The metabolic pathways of glycolysis, citric acid cycle, and amino acid metabolism were enriched, suggesting that OSCC EVs cause phenotype switch in NOFs that may contribute to acquiring a pro-tumorigenic phenotype.

• Staubo, Sara Cecilie; Fuskevåg, Ole Martin; Toft, Mathias; Lie, Ingeborg Haugesag; Alvik, Kirsti Margrete Johansen & Jostad, Pål [Vis alle 13 forfattere av denne artikkelen] (2025). Impulse control and correlation to dopamine agonist serum concentrations in people with Parkinson's disease. Journal of Neurology. ISSN 0340-5354. 272(2). doi: 10.1007/s00415-024-12870-8. Fulltekst i vitenarkiv
• Thune, Noora Helene; Kristensen, Anna Tostrup; Sehic, Amer; Brox, Julie Marie Haabeth; Utheim, Tor Paaske & Hammer, Hugo Lewi [Vis alle 7 forfattere av denne artikkelen] (2025). Comparing the Effectiveness of Human Extracted Teeth and Plastic Teeth in Teaching Dental Anatomy. Dentistry Journal. 13(3). doi: 10.3390/dj13030105. Fulltekst i vitenarkiv
• Golnarnik, Golnaz; Thiede, Bernd; Søland, Tine Merete; Galtung, Hilde & Haug, Trude Marie (2025). Hydrogen peroxide-induced oxidative stress alters protein expression in two rat salivary acinar cell lines. Archives of Oral Biology. ISSN 0003-9969. 175. doi: 10.1016/j.archoralbio.2025.106254. Fulltekst i vitenarkiv Vis sammendrag

  Objectives: This study aimed to investigate the impact of hydrogen peroxide-induced oxidative stress on the protein expression profiles of submandibular and parotid acinar cells using a proteomic approach. We sought to evaluate how oxidative stress might contribute to salivary gland dysfunction and whether the two glands respond differently.<p> <p>Design: Immortalized rat parotid gland (PG) and submandibular gland (SMG) acinar epithelial cell lines were exposed to 50 µM and 150 µM hydrogen peroxide for 24 hr, followed by protein identification and quantification via liquid chromatography-mass spectrometry. Immunofluorescence microscopy and western blot analysis validated selected protein expressions, and cell viability was assessed using trypan blue exclusion assays. <p>Results: Compared to controls, histone H4 expression increased in both cell types after hydrogen peroxide exposure, whereas voltage-dependent anion-selective channel 1, keratin 7, and keratin 8 increased only in parotid gland cells. Conversely, mitochondrial aldehyde dehydrogenase and kidney isoform glutaminase were downregulated in parotid gland cells. Basal expression of mitochondrial aldehyde dehydrogenase and catalase was higher in submandibular gland cells. At higher hydrogen peroxide concentrations, antioxidant proteins expression and cell viability were greater in submandibular gland cells compared to parotid gland cells. <p>Conclusions: Our results suggest that submandibular gland acinar cells exhibit greater resistance to oxidative stress compared to parotid gland cells, potentially due to distinct antioxidant and metabolic coping strategies. Understanding these gland-specific responses may contribute to future approaches to protect salivary glands from oxidative damage under pathological conditions.

• Voloshyna, Tetyana; Holte, Christopher Florian; Pospísil, Jakub; Szafranska, Karolina; Fuskevåg, Ole Martin & Strand, Sabina Prochazkova [Vis alle 15 forfattere av denne artikkelen] (2025). PACA nanoparticles target and deliver sildenafil to rejuvenate aged mouse liver sinusoidal endothelial cells. Nanotheranostics. 9(2), s. 155–170. doi: 10.7150/ntno.103000. Fulltekst i vitenarkiv Vis sammendrag

  Ageing is established as the most significant risk factor for disease. About 75% of people over 75 years have diabetes or pre-diabetes and/or hyperlipidaemia which are established risk factors for cardiovascular outcomes, and risk factors for age-related conditions such as dementia, sarcopenia, frailty and osteoporosis. Age-related changes in the liver microcirculation, in particular relating to the cells lining the blood vessels, the liver sinusoidal endothelial cells (LSEC), are a potential cause for dyslipidaemia and insulin resistance in old age. There is also loss of LSEC mediated waste clearance functions essential for homeostasis. Finding ways to reverse these age-related changes in the LSEC will fill a significant gap in therapeutic options available for the treatment of ageing disorders. Such therapies may also benefit patients with fibrotic livers, since LSEC changes in this disease resemble those seen in the ageing LSEC in many aspects. Nanoparticles that access systemic circulation frequently accumulate in the liver. This could be utilized as a promising strategy for targeted drug delivery to the liver. The present study assessed if poly(alkyl-cyanoacrylate) nanoparticles (PACA NPs) are a suitable vector for the targeted transport of such therapeutics to LSEC, to reverse age-related changes such as fenestration/porosity loss. Mice were co-injected with PACA NPs and formaldehyde denatured serum albumin (FSA) and their livers were then examined by microscopy. PACA and FSA co-localised to LSEC, including at the sub-cellular level in endocytic vesicles. Isolated LSEC were challenged with Nile Red (NR668) labelled PACA NPs, which were rapidly internalized. HEK293 cells overexpressing stabilin-2 internalized PACA NPs, suggesting that stabilin-2 mediates PACA uptake on LSEC. Cultured LSEC from aged mice were challenged with PACA NPs containing sildenafil and examined with scanning electron microscopy to determine effects on fenestrations. Sildenafil PACA reversed age-related changes LSEC fenestration frequency and porosity at 3-fold lower sildenafil concentrations than sildenafil alone. If sildenafil PACA induces similar changes in vivo, age-related reduction of LSEC porosity could be reversed by the targeted delivery of sildenafil via PACA NPs.

• Døving, Mats; Galteland, Pål; Næss, Ingar; Sehic, Amer; Dalby, Marius & Utheim, Tor Paaske [Vis alle 10 forfattere av denne artikkelen] (2025). Craniofacial Soft Tissue Injuries: An Observational Study of Bicycling Injuries from a Level 1 Trauma Center. The Journal of craniofacial surgery (Print). ISSN 1049-2275. 36(8), s. 2696–2700. doi: 10.1097/SCS.0000000000011409. Fulltekst i vitenarkiv Vis sammendrag

  Craniofacial injuries in bicycling accidents are common, yet limited information exists on associated soft tissue injuries. This study aims to investigate the prevalence and anatomic patterns of such injuries, and their association with helmet use and craniofacial fractures. The study included 1543 patients with bicycle injuries from a level 1 trauma center. Retrospective chart review was conducted for patients with craniofacial soft tissue injuries. Craniofacial soft tissue injuries were identified in 646 cyclists (41.9%). Odds of injury increased with years of age [aOR 1.02 (1.01–1.02), P<0.001], and women were at a higher risk compared with men [aOR 1.35 (1.05–1.75), P=0.02]. Injuries were distributed across the scalp (19%), upper third (56%), midface (69%), and lower third (32%) of the face. Helmets were used by 38% of the patients with soft tissue injuries. Helmet use reduced the odds of craniofacial soft tissue injuries overall [aOR 0.49 (0.39–0.62), P<0.001], scalp injuries [aOR 0.17 (0.10–0.28), P<0.001], and upper facial injuries [aOR 0.41 (0.31–0.54), P<0.001]. Conversely, helmet use increased the odds of lower facial injuries [aOR 1.48 (1.07–2.05), P=0.018]. Strong associations were found between lower face soft tissue injuries and mandible fractures [aOR 29.27 (15.50–55.30), P<0.001] and between soft tissue injuries of the midface and nasal bone fractures [aOR 22.70 (12.52–41.16), P<0.001]. Thus, craniofacial soft tissue injuries in cyclists are influenced by age, sex, and helmet use. Helmet use is associated with decreased odds of soft tissue injury of the upper face but with increased odds of soft tissue injury of the lower facial third.

• Brox, Julie Marie Haabeth; Tulek, Amela; Sehic, Amer; Mulic, Aida Gacic; Utheim, Tor Paaske & Khan, Qalbi (2025). Comparative analysis of the protective effects of fluoride compounds on dental erosion in mouse model. BMC Oral Health. 25(1), s. 1–10. doi: 10.1186/s12903-025-05767-z. Fulltekst i vitenarkiv Vis sammendrag

  Background Dental erosion development is affected by various factors such as types and amounts of acids, drinking habits and lifestyle choices. To prevent the onset and progression, identification of early erosive lesions as well as increased knowledge of the preventive treatment possibilities is of the importance. The aim of this study is to compare the protective effects of various fluoride compounds against dental erosion utilizing an established mouse model. Methods Three groups of ten young CD-1 mice were provided cola drink ad libitum during six weeks. Fluoride solutions containing metal components, TiF₄ (0.5 mol/l, pH 1.2, 9500 ppm F) and SnF₂ (0.5 mol/l, pH 2.6, 9500 ppm F), and a non-metal fluoride, NaF (0.5 mol/l, pH 8, 9500 ppm F) were applied to the molars under sedation twice a week. Additionally, one positive (acidic drink) and one negative (distilled water) control group were included. Mandibular molars were thereafter dissected and analyzed using scanning electron microscopy (SEM). The first molars were transversely ground, observed by SEM, and tooth height and dental hard tissue loss were measured. Further, pulp structure was described. Results The application of metal fluorides, TiF₄ and SnF₂, resulted in the formation of a protective coating layer on the molars. The overall protective effects of fluoride compounds on the development of dental erosion were evident in increasing succession from NaF, TiF₄ to SnF₂. Molars applied NaF showed a 6% reduction in tooth tissue loss compared to the untreated positive control molars. TiF₄ and SnF₂ treated molars continued to display decreased tooth tissue loss by 37% and 67%, respectively. Conclusions The metal fluorides offer superior protection against dental erosion compared to the traditional fluoride compound. The results particularly emphasize the protective effect of SnF₂, which was most effective in preserving enamel structure and minimizing dentin exposure. This suggests that SnF₂ could be an effective option for preventing dental erosions.

• Breivik, Anne; Kopperud, Simen E.; Khan, Qalbi; Mulic, Aida Gacic & Stein, Linda Maria (2025). Preventive measures and perceived challenges in delivering oral health care for elderly patients: a survey of dental hygienists in Norway. Acta Odontologica Scandinavica. ISSN 0001-6357. 84, s. 1–9. doi: 10.2340/aos.v84.42581. Fulltekst i vitenarkiv Vis sammendrag

  Objective: This study aimed to gain knowledge of general oral health preventive measures with a specific focus on root caries preventive measures for patients ≥65 years old, performed by Norwegian dental hygienists in public and private dental health services. A secondary aim was to investigate differences and challenges in prevention practices. <p> <p>Materials and methods: An electronic survey was conducted among the sample in 2022. A total of 365 dental hygienists were included in the analyses. Chi-square tests were used to analyze differences between private and public dental hygienists regarding preventive measures and perceived challenges. <p> <p>Results: The most frequently reported general oral health preventive measures were oral hygiene instruction, professional tooth cleaning and scaling. Oral hygiene instruction and application of fluoride varnish were the most performed root caries preventive measure, and reduced manual dexterity in patients was the most perceived challenge. Public dental hygienists perceived challenges to a greater extent than private dental hygienists, particularly related to reduced mobility and ergonomic difficulties in patients. <p> <p>Conclusion: This study confirms dental hygienists’ important role in oral health promotion and showed that Norwegian dental hygienists performed a wide range of preventive measures for patients ≥65 years old. However, a number of challenges were identified in the preventive work.

• Shawrob, Kazi Shefaul Mulk; Dhariwal, Achal; Salvadori, Gabriela; Gladstone, Rebecca Ashley & Junges, Roger (2025). Large-scale global molecular epidemiology of antibiotic resistance determinants in Streptococcus pneumoniae. Microbial Genomics. 11(7). doi: 10.1099/mgen.0.001444. Fulltekst i vitenarkiv Vis sammendrag

  Streptococcus pneumoniae is a leading pathogen in terms of deaths attributable to or associated with antimicrobial resistance globally. Thus, monitoring antibiotic resistance determinants constitutes a key aspect of surveillance efforts for this microbe. Leveraging publicly available whole-genome sequencing (WGS) data, we aimed to investigate the presence and distribution patterns of antibiotic resistance determinants in S. pneumoniae with a focus on multidrug resistance (MDR) and serotype distribution. Metadata and genomes were obtained from the National Center for Biotechnology Information Pathogen Detection database. Curation and harmonization were performed in R and SPSS. Data on resistance patterns were defined according to AMRFinderPlus, and a combination of prediction tools was employed for in silico serotyping. Analyses involved 75,161 genomes totalling 122,673 gene/allele counts from 14 antibiotic classes. MDR was observed in 16.7% of isolates, with the highest increasing rates in Asia and South America. Within antibiotic classes, an increase in macrolide resistance genes was highlighted, particularly in the proportion of genomes presenting mef(A)/msr(D). Over a third of isolates with serotypes 19F, 23F, 15A, 6B and 19A showed MDR. We further observed the highest significant increases in the presence of resistance in 33F, 22F, 10A and 23A. Serotype 13, not included in any vaccine formulation, presented high MDR rates with a strong increasing trend. The findings of this study highlight variations in resistance determinants globally and across serotypes over time. Collectively, these data underscore the added value of utilizing public WGS data to investigate the effectiveness and repercussions of treatment and vaccination strategies on managing antibiotic resistance.

• Kakar, Manish; Bao, Ngoc Huynh; Zlygosteva, Olga; Juvkam, Inga; Edin, Nina Frederike Jeppesen & Tomic, Oliver [Vis alle 8 forfattere av denne artikkelen] (2025). Attention-based Vision Transformer Enables Early Detection of Radiotherapy-Induced Toxicity in Magnetic Resonance Images of a Preclinical Model. Technology in Cancer Research & Treatment (TCRT). ISSN 1533-0346. 24. doi: 10.1177/15330338251333018. Fulltekst i vitenarkiv
• Champagne, Julien; Nielsen, Morten Milek; Feng, Xiaodong; Navarro, Jasmine Montenegro; Pataskar, Abhijeet & Voogd, Rhianne [Vis alle 24 forfattere av denne artikkelen] (2025). Adoptive T cell therapy targeting an inducible and broadly shared product of aberrant mRNA translation. Immunity. ISSN 1074-7613. 58(1), s. 247–262.e9. doi: 10.1016/j.immuni.2024.12.004. Fulltekst i vitenarkiv Vis sammendrag

  Prolonged exposure to interferon-gamma (IFNγ) and the associated increased expression of the enzyme indoleamine 2,3-dioxygenase 1 (IDO1) create an intracellular shortage of tryptophan in the cancer cells, which stimulates ribosomal frameshifting and tryptophan to phenylalanine (W>F) codon reassignments during protein synthesis. Here, we investigated whether such neoepitopes can be useful targets of adoptive T cell therapy. Immunopeptidomic analyses uncovered hundreds of W>F neoepitopes mainly presented by the HLA-A∗24:02 allele. We identified a T cell receptor (TCRTMBIM6W>F.1) possessing high affinity and specificity toward TMBIM6W>F/HLA-A∗24:02, the inducible W>F neoepitope with the broadest expression across cancer cell lines. TCRTMBIM6W>F.1 T cells are activated by tryptophan-depleted cancer cells but not by non-cancer cells. Finally, we provide in vivo proof of concept for clinical application, whereby TCRMART1 T cells promote cancer cell killing by TCRTMBIM6W>F.1 T cells through the generation of W>F neoepitopes. Thus, neoepitopes arising from W>F substitution present shared and highly expressed immunogenic targets with the potential to overcome current limitations in adoptive T cell therapy.

• Kristoffersen, Camilla Sofia Miranda; Ziesler, Camilla Elise Øxnevad; Thune, Noora Helene; Kristensen, Anna Tostrup; Sehic, Amer & Utheim, Tor Paaske [Vis alle 7 forfattere av denne artikkelen] (2025). Towards a Modernized Framework of Histology Teaching to Integrate Genetics: Pedagogical Perspectives for Oral Histology. Genes. 16(5). doi: 10.3390/genes16050512. Fulltekst i vitenarkiv

Se alle arbeider i NVA

• Ma, Siyao; Hong, Quan Nha; Levine, Alissa; Benali, Safaë; Petersen, Fernanda Cristina & Dawson, Aimee [Vis alle 11 forfattere av denne artikkelen] (2026). Antimicrobial Resistance Awareness and One Health Understanding among Dental Students in Quebec. Fulltekst i vitenarkiv
• Dhariwal, Achal; Salvadori, Gabriela; Åmdal, Heidi Aarø; Dutta, Anirban; Mande, Sharmila & Nangia, Sushma [Vis alle 7 forfattere av denne artikkelen] (2026). Exploring Resistomes in Low-Microbial-Biomass Airway Microbiomes Using Functional Metagenomics. Fulltekst i vitenarkiv
• Seferowicz, Maria (2026). Hva er egentlig et forsvarlig alkoholinntak? Fulltekst i vitenarkiv Vis sammendrag

  Konklusjonen i Aftenpostens kommentar bør tas med en god klype salt – helst uten medfølgende tequila.

• Sagen, Andreas Solberg; Shawrob, Kazi Shefaul Mulk; Lunde, Tracy Munthali; Sribasgaran, Biramitha; Ghafoor, Saba & Al-Haroni, Mohammed [Vis alle 9 forfattere av denne artikkelen] (2026). Mobile Genetic Elements Drive Antibiotic Resistance in Oral Streptococci. Fulltekst i vitenarkiv
• Brox, Julie Marie Haabeth (2026). Prevention is better than cure - NIOM. [Internet]. NIOM webpage. Fulltekst i vitenarkiv
• Aasland, Cecilie; Brox, Julie Marie Haabeth & Mulic, Aida Gacic (2026). Tannleger advarer: – Det er mange som ikke vet hvor skadelig det er. [Journal]. ABC Nyheter. Fulltekst i vitenarkiv Vis sammendrag

  Feil bitt, irreversible skader og behov for fasetter eller nye tenner – dette er skadene energidrikke kan føre til.

• Eftedal, Randi Krog; Brox, Julie Marie Haabeth & Mulic, Aida Gacic (2026). Når fotballen samler – og samtidig selger usunne varer. Fulltekst i vitenarkiv Vis sammendrag

  KRONIKK: Fotball-VM er først og fremst en global arena for glede, fellesskap og sterke emosjoner. Samtidig fungerer turneringen i økende grad som en kommersiell plattform der disse samme emosjonene brukes strategisk i markedsføring.

• Sapkota, Dipak (2026). Oral Epithelial Dysplasia: Old and New. Fulltekst i vitenarkiv
• Sapkota, Dipak (2026). Fibroblast functional status is crucial in regulating the phenotype of dysplastic oral keratinocytes in 3D organotypic models. doi: https:/interceptoralcancer.com/news/5th-opmday. Fulltekst i vitenarkiv
• Majewska, Marta; Maździarz, Mateusz A.; Lepiarczyk, Ewa; Lipka, Aleksandra Katarzyna; Wiszpolska, Marta & Moczulska, Beata [Vis alle 11 forfattere av denne artikkelen] (2026). Correction: Severity-dependent metabolic rewiring in COVID-19 based on untargeted metabolomic profiling of patient plasma. PLOS ONE. 21(7), s. 0354449–0354449. doi: 10.1371/journal.pone.0354449. Fulltekst i vitenarkiv
• Brox, Julie Marie Haabeth & Mulic, Aida Gacic (2026). Stor brustest: – Det er skremmende. [TV]. TV2. Fulltekst i vitenarkiv Vis sammendrag

  Da forskerne ga brus til mus skjedde det noe oppsiktsvekkende. Nå har TV 2 testet drikke for å se hvilke som er verst.

• Brox, Julie Marie Haabeth (2026). En forsker i Oslo har latt mus få drikke så mye Coca-Cola de ville. [Journal]. Forskning.no. Fulltekst i vitenarkiv Vis sammendrag

  Dette skjedde med tennene.

• Brox, Julie Marie Haabeth (2026). Ekspert advarer: Kan påvirke både helse og prestasjon. [Journal]. Aftenposten. Fulltekst i vitenarkiv Vis sammendrag

  Mange tyr til energigels og sportsdrikke for å prestere bedre. Nå advarer tannlege mot at det kan ha motsatt effekt.

• Skjerve, Hilde; Strand, Martin Frank Fjeldbu; Sørensen, Anette; Braaum, Lars Erik & Hasle, Emil Trygve (2026). Course-Aligned AI Chatbot in Higher Education. Fulltekst i vitenarkiv
• Afanou, Anani Komlavi; Sagen, Andreas Solberg; Haugen, Øyvind Pernell & Zienolddiny-Narui, Shan (2026). HDPE microplastics and fungal particle mixtures: pro-inflammatory responses in neutrophil-like cells. Fulltekst i vitenarkiv Vis sammendrag

  Objective: Microplastic pollution represents a growing environmental and public health concern, yet the immunotoxic effects of microplastics in combination with microbial contaminants remain largely unexplored. In occupational settings and moldy indoor environments, co-exposure to microplastics and fungal particles represents a plausible scenario. Methods: This study investigated the pro-inflammatory effects of high-density polyethylene (HDPE) microplastics mixed with heat-inactivated spores or mycelial fragments from Aspergillus fumigatus using differentiated HL60 neutrophil-like cells. Cells were exposed to HDPE microplastics (0–100 μg/mL) in combination with 10⁶ fungal particles for 24 hours, and cytokine release, cell viability, and Toll-like receptor (TLR) activation were assessed. Results: HDPE microplastics combined with mycelial fragments induced significant release of both IL-6 and IL-8, whereas mixtures with fungal spores induced only IL-6 release. Notably, IL-6 levels decreased with increasing HDPE concentrations in fungal particle mixtures, suggesting potential dysregulation of pro-inflammatory responses. No significant acute cytotoxicity was observed at the tested concentrations. Using HEK293 TLR reporter cells, neither HDPE microplastics, fungal particles, nor their combinations significantly activated TLR2 or TLR4, indicating involvement of alternative innate immune signaling pathways. These findings demonstrate that fungal particles, particularly mycelial fragments, are the primary drivers of pro-inflammatory responses in microplastic-fungal particle mixtures. Conclusion: Our results suggest that mycelial fragments may pose greater immunotoxic risks than spores, which are typically the focus of current risk assessments, and highlight the need for further investigation of realistic co-exposure scenarios in environmental health research.

• Dhariwal, Achal (2025). Web Tool for Microbiome and Resistome Analysis. Fulltekst i vitenarkiv
• Petersen, Fernanda Cristina (2025). Nasopharyngeal Metagenomics Reveals Trajectories Shaped by Antibiotics and a Specific Outbreak in Preterm Infants. Fulltekst i vitenarkiv
• Petersen, Fernanda Cristina (2025). Early-Life Perturbations and the Shaping of the Infant Airway Microbiome. Fulltekst i vitenarkiv
• Seferowicz, Maria (2025). Alkohol -en podkast fra spesialisthelsetjenesten. Fulltekst i vitenarkiv Vis sammendrag

  for pasienter og pårørende og helsepersonell laget av spesialisthelsetjenesten i Helse Sør-Øst.

• Brox, Julie Marie Haabeth (2025). Høstkonferansen Norsk Tannpleierforening avdeling Oslo og Akershus. doi: https:/kurs.tannpleier.no/?sort=0. Fulltekst i vitenarkiv Vis sammendrag

  45 min foredrag om doktorgradsprosjektene

• Brox, Julie Marie Haabeth (2025). ECOSEP | ECOSEP 9th Congress, November 2025, Düsseldorf-Germany. Fulltekst i vitenarkiv
• Brox, Julie Marie Haabeth & Holm, Ingrid Eline (2025). Politisk tannpine: Kan vi stoppe energi­drikkens syrlige skadevirkninger? Forskersonen.no. Fulltekst i vitenarkiv Vis sammendrag

  KRONIKK: I mars 2025 publiserte Helse- og omsorgsdepartementet forslag til en ny forskrift om forbud mot salg av energidrikk til barn under 16 år. Hva vil egentlig et forbud som dette løse?

• Sapkota, Dipak (2025). Medikamentrelatert osteonekrose i kjevene: Et økende problem som krever mer oppmerksomhet. Fulltekst i vitenarkiv
• Sapkota, Dipak (2025). Allergiske reaksjoner mot odontologiske biomaterialer. Fulltekst i vitenarkiv
• Sapkota, Dipak (2025). Allergiske reaksjoner mot odontologiske biomaterialer. Den norske tannlegeforenings Tidende. ISSN 0029-2303. Fulltekst i vitenarkiv
• Sapkota, Dipak (2025). Why Should care about oral leukoplakia? Fulltekst i vitenarkiv
• Sapkota, Dipak (2025). Can we predict the malignant potential of oral leukoplakia? Fulltekst i vitenarkiv
• Sagen, Andreas Solberg (2025). Environmental triggers of competence in Streptococcus constellatus. Fulltekst i vitenarkiv
• Sagen, Andreas Solberg; Junges, Roger & Shawrob, Kazi Shefaul Mulk (2025). External stimuli modulating the development of competence in Streptococcus constellatus. Fulltekst i vitenarkiv
• Petersen, Fernanda Cristina & Dahle, Ulf R (2025). Antimicrobial resistance: “Wake-up call” or “Dream on”? - Faculty of Dentistry. Fulltekst i vitenarkiv Vis sammendrag

  This crucial question framed the recent symposium organized by the NORSE and RESISFORCE networks in collaboration with the AMR Centre at the Norwegian Institute of Public Health (NIPH). The symposium was initiated by Fernanda Petersen, Professor at the faculty of Dentistry and the head of the RESISFORCE network and Ulf Dahle, the project leader of the NORSE-network and Head of the AMR Centre at NIPH.

• Petersen, Fernanda Cristina & Dahle, Ulf R (2025). The RESISFORCE Network. Fulltekst i vitenarkiv
• Shawrob, Kazi Shefaul Mulk; Dhariwal, Achal; Salvadori, Gabriela; Gladstone, Rebecca Ashley & Junges, Roger (2025). Global Dynamics of Antibiotic Resistance in Streptococcus pneumoniae. Fulltekst i vitenarkiv
• Dhariwal, Achal & Petersen, Fernanda Cristina (2025). Early-life Antibiotics and Hospitalization Influence Nasopharyngeal Microbiome Dynamics in preterm infants. Fulltekst i vitenarkiv
• Petersen, Fernanda Cristina; Nicolau, Belinda Farias & Junges, Roger (2025). Antimicrobial Resistance in Oral Health Care: A Global Call to Action. Fulltekst i vitenarkiv
• Bhattarai, Bishwa Prakash; Singh, Ashutosh Kumar; Singh, Rabindra; Chaulagain, Rajib; Søland, Tine Merete & Hasséus, Bengt [Vis alle 7 forfattere av denne artikkelen] (2025). Kombinasjon av lasereksisjon og fordamping kan redusere forekomsten av residiv ved oral leukoplaki. Den norske tannlegeforenings Tidende. ISSN 0029-2303. doi: 10.56373/6836e846c55bc. Fulltekst i vitenarkiv
• Dietrichs, Erik Sveberg (2025). Har forskningsformidling den impacten vi ønsker? [Radio]. Forskerrådet (podcast). Fulltekst i vitenarkiv
• Dietrichs, Erik Sveberg (2025). Ønsker seg en insentiv­ordning for formidling. [Internet]. Khrono. Fulltekst i vitenarkiv
• Eftedal, Randi Krog & Brox, Julie Marie Haabeth (2025). Barn trenger ikke barer, geler og sportsdrikker. Fulltekst i vitenarkiv
• Brox, Julie Marie Haabeth & Eftedal, Randi Krog (2025). Ukritisk vinkling på økt sukkerforbruk blant dagens idrettsungdom. Fulltekst i vitenarkiv
• Høiseth, Marikken; Bjørndal, Mathea; Hafell, Bjørnar; Fjelnset, Nina; Robertsen, Cecilie Yttervik & Eftedal, Randi Krog [Vis alle 11 forfattere av denne artikkelen] (2025). Webinar: 2x2 - Ung munnhelse på nye måter. Fulltekst i vitenarkiv
• Høiseth, Marikken; Hafell, Bjørnar; Robertsen, Cecilie Yttervik; Bøthun, Silje; Eftedal, Randi Krog & Børsting, Torunn (2025). Webinar: Undervisningsopplegg om tann/munnhelse for 8.trinn - En introduksjon til 2x2-timen. Fulltekst i vitenarkiv Vis sammendrag

  Undervisningsopplegg om tann/munnhelse for 8.trinn: En introduksjon til 2x2-timen Vi går gjennom 2x2-timen - et undervisningsopplegg om tann/munnhelse for 8.trinn   Webinaret er særlig rettet mot de som jobber på tannklinikk og jobber utadrettet med helsefremming for ungdom. Gjennomgangen holdes blant annet av Cecilie Yttervik Robertsen, folkehelsekoordinator i Trøndelag Fylkeskommune.    2x2-timen er utviklet som en del av forsknings- og innovasjonsprosjektet #Care4YoungTeeth

• Eftedal, Randi Krog; Høiseth, Marikken; Hafell, Bjørnar; Robertsen, Cecilie Yttervik & Nermo, Hege (2025). Munnhelsen påvirker hele livskvaliteten. Fulltekst i vitenarkiv
• Golnarnik, Golnaz (2026). The Impact of Oxidative Stress on Salivary Gland Acinar Cells: Ca2+ Signaling Pathways, Proteomic Changes, and Metabolomic Shifts. Universitetet i Oslo. ISSN 9788283271065. Fulltekst i vitenarkiv Vis sammendrag

  Saliva secretion is regulated by autonomic nerve signals through Ca²⁺-dependent ion transport in acinar cells, a finely tuned process that can be disrupted by oxidative stress. Such disruption is a major driver of salivary gland dysfunction and hyposalivation, as it alters cellular homeostasis and impairs glandular function early in disease progression. Understanding how oxidative stress alters Ca²⁺ signaling and redox-regulatory pathways is essential for identifying mechanisms of salivary gland dysfunction and for developing strategies to preserve gland function in diseases and in conditions such as irradiation treatment, where oxidative stress plays a central role. The overall aim of this thesis was to investigate the effects of oxidative stress on key components of the Ca²⁺ signaling system in salivary glands and to compare the proteomic and metabolomic alterations induced by oxidative stress in two major salivary gland acinar cell types. Rat-derived immortalized acinar epithelial cell lines from the parotid gland (PG) and submandibular gland (SMG) were exposed to varying concentrations of hydrogen peroxide for 24 hours to model oxidative stress. In Paper I, cell viability and intracellular ROS were measured, mRNA expression of key Ca²⁺ signaling components were analyzed by Quantitative Reverse Transcription PCR (RT-qPCR), while protein expression was assessed by western blotting and immunofluorescence microscopy. In Paper II, proteins were identified and quantified using liquid chromatography–mass spectrometry (LC-MS), and selected findings were validated by western blotting and immunofluorescence microscopy. In Paper III, metabolite profiles were analyzed using LC-MS, and succinate levels were confirmed with a biochemical assay. Together, these complementary approaches provided a multi-level analysis of oxidative stress effects on salivary gland acinar cells. In Paper I, PG cells showed impaired Ca²⁺ regulation and a greater loss of store-operated calcium entry (SOCE) components compared with SMG cells. In Paper II, proteomic analysis demonstrated reduced antioxidant enzyme expression in PG, whereas SMG maintained the level of enzymes such as catalase and ALDH2 and upregulated protective pathways including glutathione and fatty acid metabolism. In Paper III, metabolomics showed succinate accumulation in PG, while SMG preserved NADPH production and maintained redox balance. Together, these findings indicate distinct gland￾specific strategies for coping with oxidative stress, with PG cells being more vulnerable and SMG cells showing greater resilience. Overall, this thesis provides new insights into how oxidative stress affects salivary gland acinar cells at the Ca²⁺ signaling, proteomic, and metabolomic levels, highlighting molecular pathways that may contribute to gland-specific vulnerability and pointing to potential biomarkers and therapeutic targets for protecting salivary gland function in diseases.

• Haugsten, Helene Rygvold (2026). Bacterial extracellular vesicles from Porphyromonas gingivalis - a secret weapon in periodontitis? Universitetet i Oslo. ISSN 9788283271041. Fulltekst i vitenarkiv Vis sammendrag

  The bacterium Porphyromonas gingivalis (P. gingivalis) is a keystone pathogen in the development of periodontitis, a chronic disease of the periodontium affecting people worldwide. Like all eukaryotic and prokaryotic cells, P. gingivalis releases extracellular vesicles to the surrounding environment. This thesis aimed to explore the role of bacterial extracellular vesicles (bEVs) from P. gingivalis in the development of periodontitis. Three strains of P. gingivalis with different clinical virulence capacities were cultured. T hen, the bEVs were separated from the culturing medium using ultrafiltration and size exclusion chromatography before they were characterised with nano tracking analysis, transmission electron microscopy, and flow cytometry (Pa per I). Presence of the important virulence factor gingipain was detected in the bEVs and its enzymatic activity was studied in an enzyme assay. The uptake or binding of bEVs to human oral fibroblasts, an essential component of the periodontium, was observed using confocal microscopy. The bEVs were shown to contain the virulence factor gingipain and to be taken up by human gingival fibroblasts. Thereafter, metabolomic analysis was performed on human oral fibroblasts at two distinct time points after exposure to bEVs from three strains of P. gingivalis (Pa per II). Metabolic changes in the fibroblasts, indicating an early and late response to bEV exposure, were found. Additionally, the metabolic profile of bEVs themselves was analysed, and both common and strain-specific metabolites were found. Metabolites mainly associated with amino acid metabolism were common for bEVs from all three strains, which is relevant for the bacteria as they obtain their energy primarily from the metabolism of amino acids. Finally, proteomic analyses were performed on the bEVs from the same three bacterial strains (Pa per III). Here, several proteins associated with virulence were detected. Additionally, the impact of bEVs from P. gingivalis on human oral fibroblast viability and proliferation was investigated. Fibroblast response was examined at three distinct time points after their incubation with bEVs at three different concentrations. bEVs from the three strains of P. gingivalis induced varying effects on viability and proliferation depending on the strain, timepoint of exposure, and concentration of bEVs used, demonstrating that the bEVs can influence human cells. Taken together, considering the virulence factors present in the bEVs and the observed effect on fibroblasts, the data obtained in these studies indicate a role of bEVs in the development and progression of periodontitis since they contain many of the same components as the bacteria do and, thus, may be as active and pathogenic as the bacteria itself. The findings in the present thesis could serve as a framework for further detailed studies on the role of bEVs in the pathogenesis of periodontitis. In the future, the insight gained from such work may contribute both to improved monitoring of the disease and even to the treatment of periodontitis.

• Brox, Julie Marie Haabeth (2026). Dental erosion: Onset, Progression, and Prevention Strategies in a Mouse Model. Universitetet i Oslo. ISSN 9788283271034. Fulltekst i vitenarkiv Vis sammendrag

  Syreskader defineres som et irreversibelt tap av tennenes hardvev som ikke er forårsaket av bakterier, og forekommer primært som følge av inntak av sure matvarer og drikker. Ingen matvarer havner oftere i handlekurven til nordmenn enn brus, juice, energidrikker og vann med smak. 38–59 % av norske ungdommer mellom 16 og 18 år har syreskader. En viktig forklaring kan være det økende forbruket av energidrikker. Over halvparten av ungdom mellom 13 og 18 år drikker energidrikk, og blant disse gjør om lag seks av ti det ukentlig eller oftere, mens rundt én av ti drikker daglig. En konsekvens av syreskader kan være nedsatt tyggefunksjon, estetiske utfordringer, smerter og økt følsomhet. Bakgrunnen for denne avhandlingen var å utforske forebyggende strategier for økt beskyttelse mot syreskader. Det ble benyttet en allerede etablert musemodell for å studere erosjonsprosessen i detalj, ved bruk av skanning elektronmikroskop. Den første studien i denne avhandlingen beskriver utviklingen av syreskader, basert på forsøk der mus fikk drikke syreholdig drikk (Coca-Cola) i henholdsvis 2, 4 og 6 uker. I den andre studien ble ulike laboratoriefremstilte fluoridforbindelser undersøkt for deres beskyttende effekt mot syreskader hos mus som ble utsatt for Coca-Cola i 6 uker. I den siste studien ble forskjellen i beskyttende effekt mellom to kommersielt tilgjengelige fluoridforbindelser vurdert hos mus som ble eksponert for Coca-Cola i 6 uker. Resultatene fra den første studien viste akselerert tap av tannsubstans allerede etter 2 ukers eksponering for Coca-Cola. Dette fremhever betydningen av tidlig påvisning av syreskader, slik at forebyggende tiltak kan iverksettes. Den andre studien indikerte at metallfluorider gir bedre beskyttelse mot syreskader enn en tradisjonell fluoridforbindelse, særlig tinnfluorid. Resultatene fra den siste studien avdekket at sølvfluoridløsning gir bedre beskyttelse mot syreskader enn en standard fluoridlakk, og at den også kan være gunstig i behandling av overfølsomhet i tennene.

• Cai, Kun (2025). Identification and characterization of cyclic-di-AMP receptors proteins in Streptococcus mitis. Universitetet i Oslo. Fulltekst i vitenarkiv Vis sammendrag

  Streptococcus mitis er en av de dominerende bakterieartene i den orale mikrobiota og fungerer som et tidlig opphav til biofilmen som dannes på tannoverflater. Cyklisk di-adenosinmonofosfat (c-di-AMP) er et signalmolekyl i en rekke bakteriearter. Det inngår i reguleringen av et bredt spekter av fysiologiske prosesser, inkludert bakteriell vekst, koloniseringsevne og respons på ulike former for cellulært stress. Tidligere undersøkelser har bidratt til å avdekke de fysiologiske funksjonene til c-di-AMP i S. mitis, og det er påvist at c-di-AMP-signalsystemet spiller en avgjørende rolle i reguleringen av vekst, metabolisme, biofilmdannelse, reparasjon av DNA-skader samt opprettholdelse av integriteten i celleveggen under stressbetingelser. Hensikten med dette arbeidet har vært å identifisere c-di-AMP-bindende molekyler med sikte på å belyse de molekylære mekanismene ved c-di-AMP-signalsystemet i S. mitis. Særlig oppmerksomhet har vært rettet mot tre antatte c-di-AMP-bindende proteiner, nemlig CbpB, RecA og TrkA, hvor målet har vært å karakterisere deres respektive funksjoner og roller i denne sammenhengen. I avhandlingens første del ble det utviklet og etablert en LC-MS/MS-basert metode for semikvantitativ bestemmelse av intracellulære nivåer av c-di-AMP. Metoden ble senere ytterligere raffinert og optimalisert i en separat studie. I den påfølgende delen av arbeidet kunne det påvises at både CbpB og TrkA fungerer som c-di-AMP-bindende proteiner i S. mitis. CbpB viste seg å være involvert i opprettholdelsen av intracellulær homeostase av c-di-AMP gjennom interaksjon med guanosin(penta)tetrafosfat ((p)ppGpp) signalsystemet, mens TrkA ble identifisert som essensiell for vekst under betingelser med lav tilgjengelighet av kalium, i tillegg til å ha en potensiell funksjon i toleranse mot UV-indusert stress. RecA viste derimot ingen bindingsaffinitet til c-di-AMP under de eksperimentelt testede betingelsene. Likevel antyder resultatene at RecA og c-di-AMP deltar i parallelle, men uavhengige signalveier som regulerer cellens respons på DNA-skader og syrestress. Samlet sett bidrar funnene presentert i denne avhandlingen til å utvide den eksisterende forståelsen av c-di-AMP-signalisering, og peker samtidig på nye mulige tilnærminger for utvikling av målrettede terapeutiske strategier rettet mot biofilm-assosierte infeksjoner.

• Breivik, Anne; Khan, Qalbi; Stein, Linda; Mulic, Aida Gacic & Kopperud, Simen E. (2025). Prevention of root caries among elderly in Norway. Universitetet i Innlandet. ISSN 9788283805512. Fulltekst i vitenarkiv Vis sammendrag

  Fremskritt innen medisin og odontologi har ført til en betydelig forbedring av den generelle og orale helsen i befolkningen, som gjør at levealderen har økt og at flere beholder sine naturlige tenner inn i alderdommen. Karies, og spesielt rotkaries, er en stor utfordring i denne aldersgruppen i tannhelsetjenesten. Det overordnede målet for avhandlingen er derfor å øke kunnskap om forebygging av rotkaries blant eldre i Norge, noe som er avgjørende for å kunne forbedre og planlegge fremtidens ressursbehov i tannhelsetjenesten. Et laboratorieeksperiment og to tverrsnittstudier ble gjennomført. Laboratorieeksperimentet fant sted på Nordisk Institutt for Odontologiske Materialer (NIOM). Formålet i denne studien var å kvantitativt evaluere Streptococcus Mutans biofilm akkumulering på human emalje og rotoverflater, samt vurdere mengden av biofilm som ble fjernet ved bruk av (1) eksperimentell tannkrem og (2) vann, i et lukket system i flow chamber. I den første tverrsnittstudien benyttet vi oss av data fra Tromsø7 undersøkelsen, hvor 1075 deltakere over 65 år ble inkludert. Studien hadde som formål å undersøke hvilke risikoindikatorer som var assosiert med rotkaries hos eldre over 65 år. Et sekundært formål var å undersøke hvorvidt rotkaries var assosiert med oral helse-relatert livskvalitet (OHRQoL). I den andre tverrsnittstudien ble det gjennomført en nettbasert spørreundersøkelse blant 365 tannpleiere i offentlig og privat sektor, hvor formålet var å øke kunnskap om hvilke forebyggende tiltak som ble utført blant eldre over 65 år, med spesielt søkelys på forebyggelse av rotkaries. Et sekundært formål var å undersøke forskjeller og utfordringer i det forebyggende arbeidet. Laboratoriestudien (Paper I) viste at mindre biofilm ble fjernet fra rotoverflatene sammenlignet med emalje. I dataen fra Tromsøundersøkelsen (Paper II) fant vi at menn og røykere hadde høyere risiko for å utvikle rotkaries. Vi fant også at rotkaries var signifikant assosiert med oral helse-relatert livskvalitet. Resultatene fra spørreundersøkelsen (Paper III) viste at tannpleierne utførte en rekke forebyggende tiltak for eldre, selv om det opplevdes som krevende. Avhandlingen understreker betydningen av forebygging av rotkaries blant eldre og indikerer et behov for mer ressurser og økt prioritering av forebyggende strategier i tannhelsetjenesten som samsvarer med tannhelsebehovene til den aldrende befolkningen i Norge. Forskningen adresserer omfattende og viktig informasjon som bør tas i betraktning av tannhelsepersonell og beslutningstakere i det forebyggende arbeidet for denne gruppen.

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