The restoration of dentine lost in deep caries lesions in teeth is a routine and common treatment that involves the use of inorganic cements based on calcium or silicon-based mineral aggregates. Such cements remain in the tooth and fail to degrade and thus normal mineral volume is never completely restored. Here we describe a novel, biological approach to dentine restoration that stimulates the natural formation of reparative dentine via the mobilisation of resident stem cells in the tooth pulp. Biodegradable, clinically-approved collagen sponges are used to deliver low doses of small molecule glycogen synthase kinase (GSK-3) antagonists that promote the natural processes of reparative dentine formation to completely restore dentine. Since the carrier sponge is degraded over time, dentine replaces the degraded sponge leading to a complete, effective natural repair. This simple, rapid natural tooth repair process could thus potentially provide a new approach to clinical tooth restoration.
Estimating the semantic similarity between text data is one of the challenging and open research problems in the field of Natural Language Processing (NLP). The versatility of natural language makes it difficult to define rule-based methods for determining semantic similarity measures. To address this issue, various semantic similarity methods have been proposed over the years. This survey article traces the evolution of such methods beginning from traditional NLP techniques such as kernel-based methods to the most recent research work on transformer-based models, categorizing them based on their underlying principles as knowledge-based, corpus-based, deep neural network–based methods, and hybrid methods. Discussing the strengths and weaknesses of each method, this survey provides a comprehensive view of existing systems in place for new researchers to experiment and develop innovative ideas to address the issue of semantic similarity.
Immunosuppression withdrawal from calcineurin inhibitors is only possible in ~20% of liver transplant recipients. However, mTOR inhibitors (sirolimus) appear to be more immunoregulatory and might promote a tolerant state for withdrawal. Our purpose was to determine if systemic (blood, marrow, allograft) signatures of immunoregulation are promoted by conversion from tacrolimus to sirolimus. We therefore performed the following serial assays before and after sirolimus conversion in liver transplant recipients to test for enhanced markers of immunoregulation: 1) Flow cytometry immunophenotyping of PBMC and bone marrow aspirates for regulatory T cells (Tregs: CD4+CD25+++FOXP3+) and regulatory dendritic cells (DCregs: ILT3+/4+); 2) liver biopsy immunohistochemical staining (FOXP3:CD3, CD4:CD8 ratios) and immunophenotyping of biopsy-derived Tregs after growth in culture; 3) effects of pre-vs. post-conversion sera on Treg generation in mixed lymphocyte reactions; 4) peripheral blood non-specific CD4 responses (Cylex® ImmuKnow); 5) peripheral blood gene transcripts and proteomic profiles. We successfully converted 20 non-immune, non-viremic recipients (age 57.2±8; 3.5±2.1 years post-LT) from tacrolimus to sirolimus for renal dysfunction. Our results demonstrated significant increases in Tregs in PBMC and marrow and DCregs in PBMC (p<0.01) following conversion. In biopsy immunohistochemistry, FOXP3:CD3 and CD4:CD8 ratios were significantly higher after conversion and a number of biopsy cultures developed new or higher FOXP3+ cell growth. Non-specific CD4 responses (Cylex® ImmuKnow) did not change. Both pre- and post-conversion sera inhibited mixed lymphocyte reactions, although only tacrolimus sera suppressed Treg generation. Finally, 289 novel genes and 22 proteins, several important in immunoregulatory pathways, were expressed after conversion. Conclusions Tacrolimus to sirolimus conversion increases systemic Tregs, DCregs and immunoregulatory proteogenomic signatures in liver transplant recipients and may therefore facilitate immunosuppression minimization or withdrawal.
In non-growing teeth, such as mouse and human molars, primary odontoblasts are long-lived post-mitotic cells that secrete dentine throughout the life of the tooth. New odontoblast-like cells are only produced in response to a damage or trauma. Little is known about the molecular events that initiate mesenchymal stem cells to proliferate and differentiate into odontoblast-like cells in response to dentine damage. The reparative and regenerative capacity of multiple mammalian tissues depends on the activation of Wnt/β-catenin signaling pathway. In this study, we investigated the molecular role of Wnt/β-catenin signaling pathway in reparative dentinogenesis using an in vivo mouse tooth damage model. We found that Axin2 is rapidly upregulated in response to tooth damage and that these Axin2-expressing cells differentiate into new odontoblast-like cells that secrete reparative dentine. In addition, the Axin2-expressing cells produce a source of Wnt that acts in an autocrine manner to modulate reparative dentinogenesis.
Background Human papillomaviruses (HPVs) are sexually transmitted human carcinogens that may play a role in the oncogenesis of penile cancer. Objectives To investigate the role of HPV infection and expression of the tumour suppressor protein p16 INK4A in the pathogenesis of penile cancer. Methods By means of polymerase chain reaction amplification and reverse hybridization line probe assay to detect HPV infection, and immunohistochemical staining for p16 INK4A and Ki67, we analysed 26 penile squamous cell carcinomas (SCCs) and 20 independent penile lichen sclerosus (LS) lesions from 46 patients. Results HPV DNA was found in 54% of penile SCCs and 33% of penile LS cases in single and multiple infections. High-risk HPV 16 was the predominant HPV type detected. No relationship between Ki67 expression and HPV infection was observed. Strong immunostaining for p16 INK4A correlated with HPV 16/18 infection in both penile LS and penile SCC. In our penile SCC series the cancer margins were also associated with penile LS in 13 of 26 lesions, and HPV was detected in seven of the 13 SCC cases associated with LS and in six of the 11 SCC lesions not involving LS. Conclusions Our study shows a high prevalence of HPV 16 and p16 INK4A expression in penile lesions, consistent with an active role for HPV in interfering with the retinoblastoma pathway. High-risk HPV infection could be involved in the tumorigenic process in 50% of penile cancers, and the use of prophylactic HPV vaccines has the potential to prevent these cancers.
We present findings of a cancer multidisciplinary-team (MDT) coordinated mainstreaming pathway of unselected 5-panel germline BRCA1/BRCA2/RAD51C/RAD51D/BRIP1 and parallel somatic BRCA1/BRCA2 testing in all women with epithelial-OC and highlight the discordance between germline and somatic testing strategies across two cancer centres. Patients were counselled and consented by a cancer MDT member. The uptake of parallel multi-gene germline and somatic testing was 97.7%. Counselling by clinical-nurse-specialist more frequently needed >1 consultation (53.6% (30/56)) compared to a medical (15.0% (21/137)) or surgical oncologist (15.3% (17/110)) (p < 0.001). The median age was 54 (IQR = 51–62) years in germline pathogenic-variant (PV) versus 61 (IQR = 51–71) in BRCA wild-type (p = 0.001). There was no significant difference in distribution of PVs by ethnicity, stage, surgery timing or resection status. A total of 15.5% germline and 7.8% somatic BRCA1/BRCA2 PVs were identified. A total of 2.3% patients had RAD51C/RAD51D/BRIP1 PVs. A total of 11% germline PVs were large-genomic-rearrangements and missed by somatic testing. A total of 20% germline PVs are missed by somatic first BRCA-testing approach and 55.6% germline PVs missed by family history ascertainment. The somatic testing failure rate is higher (23%) for patients undergoing diagnostic biopsies. Our findings favour a prospective parallel somatic and germline panel testing approach as a clinically efficient strategy to maximise variant identification. UK Genomics test-directory criteria should be expanded to include a panel of OC genes.
The canonical Wnt/β-catenin signaling pathway is crucial for reparative dentinogenesis following tooth damage, and the modulation of this pathway affects the rate and extent of reparative dentine formation in damaged mice molars by triggering the natural process of dentinogenesis. Pharmacological stimulation of Wnt/β-catenin signaling activity by small-molecule GSK-3 inhibitor drugs following pulp exposure in mouse molars results in reparative dentinogenesis. The creation of similar but larger lesions in rat molars shows that the adenosine triphosphate (ATP)–competitive GSK-3 inhibitor, CHIR99021 (CHIR), and the ATP noncompetitive inhibitor, Tideglusib (TG), can equally enhance reparative dentine formation to fully repair an area of dentine damage up to 10 times larger, mimicking the size of small lesions in humans. To assess the chemical composition of this newly formed dentine and to compare its structure with surrounding native dentine and alveolar bone, Raman microspectroscopy analysis is used. We show that the newly formed dentine comprises equal carbonate to phosphate ratios and mineral to matrix ratios to that of native dentine, both being significantly different from bone. For an effective dentine repair, the activity of the drugs needs to be restricted to the region of damage. To investigate the range of drug-induced Wnt-activity within the dental pulp, RNA of short-term induced (24-h) molars is extracted from separated roots and crowns, and quantitative Axin2 expression is assayed. We show that the activation of Wnt/β-catenin signaling is highly restricted to pulp cells in the immediate location of the damage in the coronal pulp tissue with no drug action detected in the root pulp. These results provide further evidence that this simple method of enhancement of natural reparative dentinogenesis has the potential to be translated into a clinical direct capping approach.
Background It is unclear if new co-stimulatory blockade agents, such as the CTLA-4 Ig molecule belatacept, promote or inhibit the potential for immunological tolerance in transplantation. We therefore tested the in vitro effects of BEL on human Tregs in mixed lymphocyte reactions (Treg-MLR), alone and in combination with maintenance agents used in transplant recipients. Methods Belatacept, mycophenolic acid (MPA) and sirolimus (SRL), either singly or in combination, were added to healthy volunteer Treg-MLR, testing:(a) 3H-TdR incorporation for inhibition of lymphoproliferation;(b) flow cytometry to analyze for newly generated CD4+CD25HighFOXP3+Tregs in CFSE labeled MLR responders. In addition, the modulatory effects of putative Tregs generated in presence of these drugs were also tested using the lymphoproliferation and flow cytometric assays. Results In comparison to medium controls, BEL dose-dependently inhibited both lymphoproliferation and Treg generation in HLA 2-DR matched and mismatched MLRs, either alone or in combination with MPA or SRL. However, MPA alone inhibited lymphoproliferation but significantly enhanced Treg generation at sub-therapeutic concentrations (p<0.01). In addition, purified CD4+CD127− cells generated in MLR in the presence of MPA and added as third component modulators in fresh MLRs significantly enhanced newly developed Tregs in the proliferating responder cells, compared to those generated with BEL or medium controls. Conclusions Belatacept alone and in combination with agents used in transplant recipients inhibits the in vitro generation of human Tregs. Belatacept might therefore be a less optimal agent for tolerance induction in human organ transplantation.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.