A Comparative Evaluation of Contact Angle and Depth of Penetration of Sodium Hypochlorite With Various Surfactants: An In Vitro Study.

OBJECTIVE: Sodium hypochlorite (NaOCl) is regarded as the most frequently used root canal irrigant. Its high surface tension prevents its penetration into complex canal anatomies. The present study assesses the contact angle and penetration depth of 2.5% NaOCl with 0.2% cetrimide and propylene glycol. MATERIAL AND METHODS: Sixty recently extracted mandibular premolars with a single root were obtained. Thirty were sectioned longitudinally, and the remaining 30 teeth were sectioned transversely. Acrylic blocks were used to mount the parts, and 5 µL of each of the following solutions was placed on the dentin surface: Group 1: 2.5% NaOCl (control), Group 2: 0.2% cetrimide + 2.5% NaOCl, and Group 3: propylene glycol + 2.5% NaOCl. Following this, contact angle analysis was made using a contact angle goniometer. We prepared and instrumented access cavities in 30 teeth to work up to the size of the ProTaper Gold F2 (Dentsply Tulsa Dental Specialties, Tulsa, OK). Samples were allocated to the three groups, and irrigation was done accordingly. They were sectioned at the coronal, middle, and apical thirds and then subjected to confocal laser scanning microscopy. The data were analyzed using a one-way ANOVA and a Tukey multiple comparison test. RESULTS: Group 2 had the least contact angle (35.20°) and the highest depth of penetration (DOP; 752.409 µm) when compared to Groups 1 and 3. The DOP decreased significantly from the coronal, middle, and apical thirds. No discernible variation in the contact angle was found between the radicular and coronal portions. CONCLUSION: 0.2% cetrimide improved the efficiency of 2.5% NaOCl as an irrigant by lowering its contact angle and increasing its DOP.

Literature-Based Discovery Predicts Antihistamines Are a Promising Repurposed Adjuvant Therapy for Parkinson's Disease.

Parkinson's disease (PD) is a movement disorder caused by a dopamine deficit in the brain. Current therapies primarily focus on dopamine modulators or replacements, such as levodopa. Although dopamine replacement can help alleviate PD symptoms, therapies targeting the underlying neurodegenerative process are limited. The study objective was to use artificial intelligence to rank the most promising repurposed drug candidates for PD. Natural language processing (NLP) techniques were used to extract text relationships from 33+ million biomedical journal articles from PubMed and map relationships between genes, proteins, drugs, diseases, etc., into a knowledge graph. Cross-domain text mining, hub network analysis, and unsupervised learning rank aggregation were performed in SemNet 2.0 to predict the most relevant drug candidates to levodopa and PD using relevance-based HeteSim scores. The top predicted adjuvant PD therapies included ebastine, an antihistamine for perennial allergic rhinitis; levocetirizine, another antihistamine; vancomycin, a powerful antibiotic; captopril, an angiotensin-converting enzyme (ACE) inhibitor; and neramexane, an N-methyl-D-aspartate (NMDA) receptor agonist. Cross-domain text mining predicted that antihistamines exhibit the capacity to synergistically alleviate Parkinsonian symptoms when used with dopamine modulators like levodopa or levodopa-carbidopa. The relationship patterns among the identified adjuvant candidates suggest that the likely therapeutic mechanism(s) of action of antihistamines for combatting the multi-factorial PD pathology include counteracting oxidative stress, amending the balance of neurotransmitters, and decreasing the proliferation of inflammatory mediators. Finally, cross-domain text mining interestingly predicted a strong relationship between PD and liver disease.

Student Performance on Course Objectives in a First-Year Medical School Foundational Science Course Correlate with USMLE Step 1 Scores.

Purpose: Early identification of students at risk for poor United States Medical Licensing Examination® (USMLE) Step 1 examination (Step 1) performance allows medical schools to provide targeted intervention for those students. Therefore, determination of metrics that identify struggling students is necessary for proper intervention. We hypothesize that; 1) student performance on pre-matriculation metrics will correlate with their Molecular and Cellular Foundations of Medicine (FDNS) course performance and 2) student performance in the FDNS course and on specific FDNS course objectives will correlate with their Step 1 performance. Methods: This was a retrospective cohort study analyzing data for students matriculating to the University of South Carolina School of Medicine Greenville in 2018 and 2019. Linear regression analysis was conducted to assess the correlation between pre-matriculation metrics, performance in the FDNS course, performance on FDNS objectives, and USMLE Step 1 performance. Adjusted R-squared (adjusted r2) values were compared with a p-value at <0.05. Results: The FDNS course grade correlated with pre-matriculation metrics of science undergraduate grade point average (uGPA), total uGPA, and the Medical College Admission Test (MCAT), adjusted r2 of 0.139, 0.121, 0.223, respectively. The FDNS course grade showed a stronger correlation to USMLE Step 1 performance (adjusted r2 = 0.257) than pre-matriculation metrics. USMLE Step 1 performance strongly correlated with FDNS course performance when two objectives, pertaining to anabolic and catabolic processes, regulation of cell cycle, and DNA replication and repair, were combined, adjusted r2 of 0.357. Conclusion: The FDNS course grade and performance on specific course objectives could serve as a predictor for USMLE Step 1 performance and provides a more targeted and concise approach to identification of low-performing students and subsequent intervention.

Enhanced access and isolation by simple modifications of dental armamentarium.

A good armamentarium facilitates the efficient working of the dentist which in turn improves the quality of treatment rendered to the patient. The present invention of the unit consisting of the flexible mirror attached to the suction and the dual suction tip aims at improving the clinical efficiency of dental treatments provided. This compact unit is designed to improve the visualization and isolation of the operating field. It is also easy to fabricate and alleviates the very relevant shortcomings of clinical work.

Evaluation of Aloe vera as matrix metalloproteinase inhibitor in human dentin with and without dentin-bonding agent: An in vitro study.

Background: Proper hybrid layer formation lays the foundation of resin-dentin bonding. The resin infiltration in demineralized dentin collagen couples with the adhesive/resin composites in the mineralized dentin surface. However, the activation of enzymatic activity in the collagen matrix can degrade the hybrid layer. Over the time, it leads to reduced bond strength. Mainly, the enzymes involved are matrix metalloproteinases (MMPs) which are involved in degrading most of the extracellular matrix components. Aloe vera is an herb with an anti-inflammatory effect, but its role in human dentin as an enzyme inhibitor has not been verified yet. Aims: The purpose of the study was designed for evaluating the inhibitory action of Aloe vera on MMP in human dentin with and without dentin bonding agents. Materials and Methods: A total of 15 freshly extracted healthy human teeth were collected and stored at 4°C until use. The roots were separated. The enamel and remnant pulp tissue were removed, and collected teeth were pulverized with liquid nitrogen in the minimum volume of 50-mM phosphate buffer to obtain dentin powder extract. The dentin powder extract is the source of MMPs, and therefore, the extract was treated with A. vera solution and incubated to assess the enzyme inhibition by the plate assay method and zymographic analysis. Results: A. vera treated sample with and without dentin bonding agent showed inhibition of dentin MMP's activity by plate assay method and confirmed by zymogram analysis. Conclusions: A. vera has the potential for inhibiting the MMPs enzyme activity of human dentin collagen with and without dentin bonding agents.

Experiences with stigma and discrimination among adolescents and young adults living with HIV in Bangkok, Thailand.

Thailand has identified stigma and discrimination as barriers to controlling their HIV epidemic. We aimed to explore the perspectives of young adults living with HIV in Bangkok regarding the influence of stigma and discrimination in education, employment, health care, personal relationships, and perceptions of self. Participants aged 15-24 years were conveniently and purposively sampled from local HIV clinics in Bangkok. Twenty-three individuals (14 female, 9 male; median age 20) were enrolled into the study between May and June 2017. Semi-structured qualitative interviews were conducted in Thai. Interview transcripts were translated into English and analyzed with Dedoose software (v7.6.12) using a framework analysis approach. Participants reported varied experiences with and beliefs about HIV-related stigma as they related to family, employment, education, and society. While few experienced discrimination, such as losing opportunities at work or school, all reported anticipating potential stigma and fearing negative repercussions from disclosure. Many participants reported that fear of disclosure negatively impacted their medication adherence. For the individuals interviewed, fear of stigma was a daily consideration. Many experienced HIV-related stigma in school, at work, within their communities, and in their inter-personal relationships. Anti-stigma efforts should include strategies that address the needs of young adults.

Piloting an HIV self-test kit voucher program to raise serostatus awareness of high-risk African Americans, Los Angeles.

BACKGROUND: Up to half of all new HIV cases in Los Angeles may be caused by the 20-30% of men who have sex with men (MSM) with unrecognized HIV infection. Racial/ethnic minority MSM are at particularly high risk for being sero-unaware and due to stigma and poor healthcare access might benefit from novel private, self-testing methods, such as the recently FDA-approved OraQuick® In-Home HIV Test. METHODS: From July-November 2013, we undertook a pilot study to examine the feasibility of a voucher program for free OraQuick® tests targeting African American MSM in Los Angeles. We determined feasibility based on: (1) the establishment of a voucher redemption and third-party payment system, (2) the willingness of community-based organizations (CBOs) to disseminate vouchers, and (3) the collection of user demographics, test and linkage-to-care results with an anonymous telephone survey. RESULTS: We partnered with Walgreens® to create a voucher and third-party reimbursement system for free OraQuick® tests. Voucher distribution was divided into two periods. In total, 641 vouchers were supplied to CBOs: 274 (42.7%) went to clients and of those 53 (19.3%) were redeemed. Fifty (18.2%) of the 274 clients were surveyed: 44 (88%) were African American, 39 (78%) reported being likely to repeat voucher use, 44 (88%) reported reviewing pre-test information, and 37 (74%) the post-test information. Three (6%) of 50 survey respondents reported newly testing HIV-positive of whom all (100%) reported seeking medical care. Two withheld their results, both of whom also sought medical care. CONCLUSIONS: Developing and partnering with a commercial pharmacy to institute a voucher system to facilitate HIV self-testing with linkage-to-care was feasible. Our findings suggest the voucher program was associated with increasing the identification of new cases of HIV infection with high rates of linkage to care. Expanded research and evaluation of voucher programs for HIV self-test kits among high-risk groups is warranted.