Expression of Toll-like receptor 2, Dectin-1, and Osteopontin in murine model of pulpitis.

OBJECTIVES: This in vivo animal study aimed to develop a murine model of pulpitis induced by pulp exposure with or without application of zymosan in Naval Medical Research Institute (NMRI) mice and observe expressions of Toll-like receptor (TLR)-2, TLR-4, Dectin-1, Osteopontin (OPN), tumor necrosis factor alpha (TNF-α), interleukin (IL)-6, and IL-1ß. MATERIAL AND METHODS: A total of 168 NMRI mice were divided into two groups, i.e., group A (n = 84) (pulpitis induced by pulp exposure only) and group B (n = 84) (pulpitis induced by pulp exposure and zymosan application). Right maxillary molar pulps were exposed with » round bur, and animals were sacrificed at 0, 6, 9, 12, 24, 48, and 72 h. The exposed teeth were obtained for real-time polymerase chain reaction (qRT-PCR) analysis and histological and immunohistochemistry (IHC) analysis. RESULTS: Histological evaluation revealed a time-dependent steady increase in inflammation. Similar time-dependent increase in the expression of inflammatory cytokines was noted. Group A exhibited an increase in TLR-4, Dectin-1, and OPN at 6 h, while TLR-2 was expressed at 24 h. Group B expressed TLR-2, Dectin-1, and OPN at 9, 48, and 72 h, respectively (p ≤ 0.05). Expression of OPN and TNF-α exhibited a similar pattern in both groups. IHC also detected expression of TLR-2, Dectin-1, TLR4, and CD68 in some cells at 6 and 9 h. CONCLUSIONS: NMRI mice provided for a stable pulp inflammation model. Zymosan may be used to develop pulp inflammation model and study inflammatory response towards fungal antigens. Dental pulp expressed Dectin-1 receptor. OPN and TNF-α exhibited a similar expression pattern. CLINICAL RELEVANCE: Innate immunity of dental pulp is capable of detecting fungal pathogens.

A novel experimental model to investigate fungal involvement shows expression of Dectin-1 in periapical lesion pathogenesis.

BACKGROUND: Candida albicans is linked to persistent endodontic lesions. However, the recognition receptor that identifies it is not explored previously. OBJECTIVES: The aim of this study was to (1) establish a zymosan-induced model of apical periodontitis in mouse, (2) observe the expression of Dectin-1 and its possible relationship with toll-like receptor (TLR) 2 and (3) observe relationship between Osteopontin (OPN) and inflammatory cytokines. METHODS: A total of 138 Naval Medical Research Institute (NMRI) mice were randomly divided into; Experimental Group n = 69 and Zymosan Group n = 69. Periapical periodontitis was developed in right maxillary molar. The animals were sacrificed at 7, 21 and 42 days. Bone blocks containing the mesial root (n = 15 for qRT-PCR, n = 45 for enzyme-linked immune sorbent assay (ELISA)) were collected for mRNA expression and ELISA. While whole maxilla (n = 3 from each time interval) were used for histology and immunohistochemical analysis. One way analysis of variance (ANOVA) and Tuckey's posthoc was used for statistical analysis at p ≤ .05. RESULTS: TLR-2, Dectin-1 and TLR4-positive cells was detected at all time intervals in both groups. A strong positive correlation was observed between TLR-2 and Dectin-1 in both lesions (regular r = .680, p = .015, zymosan (r = .861, p < .001)). A significant correlation was found between OPN and tumour necrosis factor-alpha (TNF-α) in zymosan lesion (r = .827, p = .001). CONCLUSIONS: Immune cells of inflamed periapical tissue expressed Dectin-1 receptor in response to the microbial challenge from infected root canals and showed positive correlation with TLR-2 and OPN suggesting a possible receptor collaboration mediated by OPN. The expression of OPN and TNF-α showed positive correlation in response to fungal antigen, indicating a possible relationship.

Gene expression analysis of toll like receptor 2 and 4, Dectin-1, Osteopontin and inflammatory cytokines in human dental pulp ex-vivo.

BACKGROUND: Toll like receptors (TLR) 2 and 4 present on innate immune cells of the dental pulp detect cariogenic bacteria. Along with bacteria, C. albicans may also be present in dental caries. The presence of C. albicans can be detected by Dectin-1 a C type Lectin receptor. Expression of Dectin-1 in human pulpits has not been reported. Similarly, cytokines are released as a consequence of dental pulp inflammation caused by cariogenic bacteria. The T helper (Th) 1 inflammatory response leads to exacerbation of inflammation and its relationship with Osteopontin (OPN) is not known in pulp inflammation. OBJECTIVE: The aim of this study was to observe the expression of Dectin-1, TLR-2, OPN and pro-inflammatory cytokines in irreversibly inflamed human dental pulp and to observe relationship between Dectin-1/TLR-2 and OPN/Pro-inflammatory cytokines in the presence of appropriate controls. METHODS: A total of 28 subjects diagnosed with irreversible pulpitis were included in this ex-vivo study. Fifteen samples were subjected to standard hematoxylin and Eosin (H&E) and immunohistochemistry staining. Whereas, gene expression analysis was performed on 13 samples to observe mRNA expression of pro-inflammatory cytokines; tumor necrosis factor-alpha (TNF-α), interleukin (IL)-1 beta (ß), IL-6 Dectin-1, OPN, TLR-2 and TLR-4. SPSS version 21 was used for statistical analysis. One way analysis of variance (ANOVA), Pearson correlation and Chi-square test were used at p ≤ 0.05. RESULTS: Gene expressions of Dectin-1, TLR-2 and TLR-4 were observed in all samples. Dectin-1 and TLR-2 expressions were significantly correlated (r = 0.5587, p = 0.0002). Similarly, OPN and TNF-α expression showed a significant correlation (r = 0.5860, p = 0001). The agreement between histologic and clinical diagnosis was 69.2% in the cases of irreversible pulpitis. CONCLUSION: Dectin-1 was expressed by inflamed human dental pulp. Dectin-1 and TLR-2 expression pattern was suggestive of a collaborative receptor response in inflamed pulp environment. OPN and TNF-α expressions showed a positive correlation indicating a possible relationship.

Predicting Success: A Comprehensive Analysis of High School and Admission Test Scores on Future Academic Performance of Dental Students.

Introduction Dental school admissions in Pakistan traditionally rely on Higher Secondary School Certificate (HSSC), University of Health Sciences (UHS), and National Testing Service (NTS) scores, with limited research available on their predictive validity for dental school performance. This study aims to investigate the correlation between a student's first-year dental school performance and their HSSC, UHS, and NTS scores. Methods A total of 282 records, spanning the years 2016 to 2020, were obtained from a single private dental institution. The data included HSSC, UHS, and/or NTS scores, with the first professional examination results as the dependent variable. Statistical analysis was conducted using the Statistical Package for the Social Sciences (IBM SPSS Statistics for Windows, IBM Corp., Version 25.0, Armonk, NY), encompassing descriptive statistics, Pearson's correlation coefficients, and multiple regression analysis. Results Pearson's coefficients revealed weak to moderate positive correlations between the first professional examination and HSSC (r=0.209, p<.01), UHS (r=0.344, p<.01), and NTS (r=0.350, p<.01), all statistically significant at p < 0.01. Multiple regression analysis indicated that UHS scores contributed the highest explanatory power (R² = 0.146) in predicting first professional examination results. Conclusion A positive correlation between HSSC, UHS, and NTS scores with dental students' performance in the first professional examination is observed. However, the correlations are moderate, highlighting the importance of incorporating assessments that consider cognitive, behavioral, and skill-related aspects in admissions processes. Given the evolving landscape of dental education, these findings underscore the need for a holistic approach to identify candidates better equipped to serve the healthcare sector.

On Smart Gaze Based Annotation of Histopathology Images for Training of Deep Convolutional Neural Networks.

Unavailability of large training datasets is a bottleneck that needs to be overcome to realize the true potential of deep learning in histopathology applications. Although slide digitization via whole slide imaging scanners has increased the speed of data acquisition, labeling of virtual slides requires a substantial time investment from pathologists. Eye gaze annotations have the potential to speed up the slide labeling process. This work explores the viability and timing comparisons of eye gaze labeling compared to conventional manual labeling for training object detectors. Challenges associated with gaze based labeling and methods to refine the coarse data annotations for subsequent object detection are also discussed. Results demonstrate that gaze tracking based labeling can save valuable pathologist time and delivers good performance when employed for training a deep object detector. Using the task of localization of Keratin Pearls in cases of oral squamous cell carcinoma as a test case, we compare the performance gap between deep object detectors trained using hand-labelled and gaze-labelled data. On average, compared to 'Bounding-box' based hand-labeling, gaze-labeling required 57.6% less time per label and compared to 'Freehand' labeling, gaze-labeling required on average 85% less time per label.

Efficacy of 0.1% tacrolimus in long-term management of erosive lichen planus.

OBJECTIVES: This study documented the response of erosive oral lichen planus (OLP) to exclusive treatment with 0.1% topical tacrolimus over a 12-month period or until the patient became unresponsive to therapy. MATERIALS AND METHODS: A retrospective cohort design was used to acquire data on 12 patients with recalcitrant OLP that were prescribed 0.1% tacrolimus. These patients were prescribed 0.1% tacrolimus after failing to respond to conventional corticosteroid therapy. Information about their response to medication initially and on flare ups were included in this study. RESULTS: The sample consisted of nine women and three men. All patients were given 0.1% tacrolimus to be applied 3 times a day. Two patients did not respond to the treatment at all, 4 patients showed partial response to tacrolimus treatment. Six patients showed complete initial response to treatment. CONCLUSION: 50% of our patients showed a suboptimal response to 0.1% tacrolimus use for erosive OLP, thus, suggesting that in some cases 0.1% tacrolimus may be an ineffective option for managing erosive OLP.

Automated feature detection in dental periapical radiographs by using deep learning.

OBJECTIVE: The aim of this study was to investigate automated feature detection, segmentation, and quantification of common findings in periapical radiographs (PRs) by using deep learning (DL)-based computer vision techniques. STUDY DESIGN: Caries, alveolar bone recession, and interradicular radiolucencies were labeled on 206 digital PRs by 3 specialists (2 oral pathologists and 1 endodontist). The PRs were divided into "Training and Validation" and "Test" data sets consisting of 176 and 30 PRs, respectively. Multiple transformations of image data were used as input to deep neural networks during training. Outcomes of existing and purpose-built DL architectures were compared to identify the most suitable architecture for automated analysis. RESULTS: The U-Net architecture and its variant significantly outperformed Xnet and SegNet in all metrics. The overall best performing architecture on the validation data set was "U-Net+Densenet121" (mean intersection over union [mIoU] = 0.501; Dice coefficient = 0.569). Performance of all architectures degraded on the "Test" data set; "U-Net" delivered the best performance (mIoU = 0.402; Dice coefficient = 0.453). Interradicular radiolucencies were the most difficult to segment. CONCLUSIONS: DL has potential for automated analysis of PRs but warrants further research. Among existing off-the-shelf architectures, U-Net and its variants delivered the best performance. Further performance gains can be obtained via purpose-built architectures and a larger multicentric cohort.

Cancer Image Quantification With And Without, Expensive Whole Slide Imaging Scanners.

Automated analysis of digitized pathology images in tele-health applications can have a transformative impact on under-served communities in the developing world. However, the vast majority of existing image analysis algorithms are trained on slide images acquired via expensive Whole-Slide-Imaging (WSI) scanners. High scanner cost is a key bottleneck preventing large-scale adoption of digital pathology in developing countries. In this work, we investigate the viability of automated analysis of slide images captured from the eyepiece of a microscope via a smart phone. The mitosis detection application is considered as a use case.Results indicate performance degradation when using (lower-quality) smartphone images; as expected. However, the performance gap is not too wide (F1-score smartphone=0.65, F1-score WSI=0.70) demonstrating that smartphones could potentially be employed as image acquisition devices for digital pathology at locations where expensive scanners are not available.

Novel Clonal t(2;4) (q23;p14) Secondary Cytogenetic Abnormality in a Primary Myxoid Liposarcoma.

Myxoid liposarcomas are malignant lipomatous tumors with a predilection for young adults. They are characterized by the presence of reciprocal translocation between the CHOP (DDIT3) gene on chromosome 12 and the FUS gene on chromosome 16, t(12;16)(q13;p11.2) in >95% of cases, or less commonly, a translocation between the DDIT3 and EWSR1 genes, t(12;22)(q13;q12). Secondary aberrations involving trisomy 8 and chromosomes 1 and 16 have been reported. Herein, we report for the first time a novel secondary clonal translocation, t(2;4) (q23;p14) in addition to t(12;16)(q13; p11.2) in a 30-year-old woman with myxoid liposarcoma on the left posterior thigh region without any prior chemoradiation therapy. The significance of this translocation remains to be established.

Clinical and biochemical studies support smokeless tobacco's carcinogenic potential in the human oral cavity.

In 2007, the International Agency for Research on Cancer presented compelling evidence that linked smokeless tobacco use to the development of human oral cancer. Although these findings imply vigorous local carcinogen metabolism, little is known about levels and distribution of phase I, II, and III (drug egress) enzymes in human oral mucosa. In this study here, we integrated clinical data, and imaging and histopathologic analyses of an oral squamous cell carcinoma that arose at the site of smokeless tobacco quid placement in a patient. Immunoblot and immunohistochemical (IHC) analyses were used to identify tumor and normal human oral mucosal smokeless tobacco-associated metabolic activation and detoxification enzymes. Human oral epithelium contains every known phase I enzyme associated with nitrosamine oxidative bioactivation with approximately 2-fold interdonor differences in protein levels. Previous studies have confirmed approximately 3.5-fold interdonor variations in intraepithelial phase II enzymes. Unlike the superficially located enzymes in nonreplicating esophageal surface epithelium, IHC studies confirmed that oral mucosal nitrosamine metabolizing enzymes reside in the basilar and suprabasilar region, which notably is the site of ongoing keratinocyte DNA replication. Clearly, variations in product composition, nitrosamine metabolism, and exposure duration will modulate clinical outcomes. The data presented here form a coherent picture consistent with the abundant experimental data that link tobacco-specific nitrosamines to human oral cancer.