TRPC3 Regulates Islet Beta-Cell Insulin Secretion

Insulin release is tightly controlled by glucose-stimulated calcium (GSCa) through hitherto equivocal pathways. This study investigates TRPC3, a non-selective cation channel, as a critical regulator of insulin secretion and glucose control. TRPC3's involvement in glucose-stimulated insulin secretion (GSIS) is studied in human and animal islets. TRPC3-dependent in vivo insulin secretion is investigated using pharmacological tools and Trpc3-/- mice. TRPC3's involvement in islet glucose uptake and GSCa is explored using fluorescent glucose analogue 2-[N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl) amino]-2-deoxy-D-glucose and calcium imaging. TRPC3 modulation by a small-molecule activator, GSK1702934A, is evaluated in type 2 diabetic mice. TRPC3 is functionally expressed in human and mouse islet beta cells. TRPC3-controlled insulin secretion is KATP -independent and primarily mediated by diacylglycerol channel regulation of the cytosolic calcium oscillations following glucose stimulation. Conversely, glucose uptake in islets is independent of TRPC3. TRPC3 pharmacologic inhibition and knockout in mice lead to defective insulin secretion and glucose intolerance. Subsequently, TRPC3 activation through targeted small-molecule enhances insulin secretion and alleviates diabetes hallmarks in animals. This study imputes a function for TRPC3 at the onset of GSIS. These insights strengthen one's knowledge of insulin secretion physiology and set forth the TRPC3 channel as an appealing candidate for drug development in the treatment of diabetes.

Toward better characterization of restricted and repetitive behaviors in individuals with germline heterozygous PTEN mutations

This study aimed to further our understanding of restricted and repetitive behaviors (RRB) among individuals with germline pathogenic mutations in PTEN by providing multimethod characterization and comparison of key RRB subdomains across individuals with PTEN mutations with autism spectrum disorder (ASD) (PTEN-ASD), with PTEN mutations without ASD (PTEN-No ASD) and with ASD and macrocephaly but without PTEN mutations (Macro-ASD). Of 86 total research participants, 38 had PTEN-ASD (M_age  = 8.93 years, SD_age  = 4.75), 25 Macro-ASD (M_age  = 11.99 years; SD_age  = 5.15), and 23 PTEN-No ASD (M_age  = 8.94 years; SD_age  = 4.85). The Repetitive Behavior Scale-Revised (RBS-R) and the Autism Diagnostic Interview-Revised (ADI-R) were used as measures of distinct RRB domains. There were significant group differences in the RBS-R repetitive motor behaviors (RMB; F = 4.52, p = 0.014, ω²  = 0.08), insistence on sameness (IS; F = 4.11, p = 0.02, ω²  = 0.05), and circumscribed interests (CI; F = 7.80, p = 0.001, ω²  = 0.14) scales. Post hoc comparisons showed that the PTEN-No ASD group had significantly lower RMB, IS, and CI scores compared to both PTEN-ASD and Macro-ASD groups. Importantly, PTEN-No ASD group still showed elevated RRB levels. Furthermore, there was a portion of individuals in PTEN-No ASD group whose Full-Scale Intelligence Quotient (FSIQ) was >70 that did not show floor level scores in the RMB domain. After adjusting for age and FSIQ scores, group differences were no longer statistically significant. RMB, IS, and CI domains showed distinct association patterns with sex, age, and FSIQ. This investigation provides the largest and most comprehensive characterization of distinct RRB domains in individuals with PTEN mutations to date. Despite the limitations, our findings have important assessment and treatment implications.

The prevalence of screened trichotillomania in medical students of Saint-Joseph University

OBJECTIVES

Our study aims to determine the prevalence of trichotillomania among medical students. Furthermore, we aim to determine the perception of trichotillomania in this population.

METHODS

Our study is a cross-sectional study that aims to determine the prevalence and the perception of trichotillomania among medical students in, compared to a control population. The control population were non-medical students in the same university. The participants filled a questionnaire online, followed by a psychiatric assessment if needed to confirm the diagnosis. The questionnaire contained three parts that consist of demographic data, diagnostic criteria and two perception questions respectfully. All the individuals that had a positive questionnaire refused to undergo a psychiatric assessment. Consequently, our study is limited to the screening of trichotillomania.

RESULTS

In total, 489 answers were recorded. The prevalence of trichotillomania in the general population was estimated at 2.2% (N=11). A total of 215 medical students and 274 controls filled the form. The prevalence of trichotillomania in medical students was 0.9% (N=2), whereas in the control population, the prevalence was estimated at 3.3% (N=9). The difference was statistically insignificant (P=0.123). Among medical students, all the positive questionnaires were females. In the control population, seven of them were females and two of them were males. In total, the sex ratio would be 4.5 females for one male when both populations are combined. All the individuals that had a positive questionnaire either refused to undergo a psychiatric assessment or did not answer call-backs. Regarding the perception of trichotillomania, almost three quarters of the responders think that it is due to anxiety. There was a statistical difference between the medical students and the control population regarding the answer to the proposition "It is a psychiatric disease". Medical students (76.7%) tend to believe that more than the others do (48.9%) with a p-value less than 0.00001. In addition, the same difference is found when comparing medicals students that took psychiatric courses (86.2%) to those that did not (59.7%) with a p-value at 0.0001. Almost all students think trichotillomania is treatable.

CONCLUSION

The prevalence of trichotillomania among medical students is 0.9%. Medical students are not more or less affected by trichotillomania than other students. A screening tool must be considered for this disease, considering the lack. Medical students with psychiatric knowledge know more about trichotillomania than others. For this reason, awareness campaigns regarding this disease must be done to increase general knowledge.

Brief Report: Role of Parent-Reported Executive Functioning and Anxiety in Insistence on Sameness in Individuals with Germline PTEN Mutations

This study aimed to characterize the relationship between insistence on sameness (IS), executive functioning (EF) and anxiety among individuals with PTEN mutations and individuals with macrocephalic ASD. The sample included 38 individuals with PTEN mutation and ASD diagnosis (PTEN-ASD; M_age = 8.93 years, SD_age = 4.75), 23 with PTEN mutation without ASD (PTEN-no ASD; M_age = 8.94 years; SD_age = 4.85) and 25 with ASD and macrocephaly but with no PTEN mutation (Macro-ASD; M_age = 11.99 years; SD_age = 5.15). The final model accounted for 45.7% of variance in IS, with Set-Shifting EF subdomain as a unique independent predictor (t = 4.12, p < 0.001). This investigation provides the first preliminary evidence for the EF-anxiety-IS interrelationship in individuals with PTEN mutations and with macrocephalic ASD.

Psychiatric Characteristics Across Individuals With PTEN Mutations

Germline heterozygous PTEN mutations have been associated with high prevalence of autism spectrum disorder (ASD) and elevated rates and severity of broadly defined behavioral problems. However, limited progress has been made toward understanding whether PTEN mutation is associated with specific psychiatric co-morbidity profiles when compared to idiopathic ASD. The current study aimed to utilize a cross-measure approach to compare concurrent psychiatric characteristics across children and adolescents with PTEN mutation with (PTEN-ASD; n = 38) and without ASD (PTEN-No ASD; n = 23), and ASD with macrocephaly but no PTEN mutation (macro-ASD; n = 25) using the Child Behavior Checklist (CBCL) and the Aberrant Behavior Checklist (ABC). There were significant group effects for the CBCL Internalizing and Externalizing broad symptom score, the majority of specific CBCL syndrome scores, and all ABC subscale scores. Post-hoc comparisons revealed greater behavioral symptoms in the ASD groups (PTEN-ASD and macro-ASD) compared to the PTEN-no ASD group on nearly all subtest scores examined. There were no statistically significant differences between the PTEN-ASD and macro-ASD groups; however, there was a trend for the macro-ASD group showing higher levels of aggressive behaviors. Our findings provide evidence of specific behavior profiles across PTEN-No ASD, PTEN-ASD, and macro-ASD groups and highlight the importance of early identification of behavioral vulnerabilities in individuals with PTEN mutations in order to provide access to appropriate evidence-based interventions.

Beneficial role of simvastatin in experimental autoimmune myositis

OBJECTIVE

Statins have immunomodulatory potential in autoimmune diseases but had not been studied as a disease-modifying agent in inflammatory myopathies. The objective of this study is to assess the effect of simvastatin in an experimental model of autoimmune myositis in mice on muscle strength and histopathology.

METHODS

Four groups of mice (n = 5 per group) were selected for experimentally induced myositis. Mice were immunized with 1.5 mg myosin in complete Freund's adjuvant weekly for two times and injected with 500 ng pertussis toxin twice immediately after each immunization. From day 1 before immunization to 10 days after the last immunization, mice were treated with oral simvastatin (10 or 20 or 40 mg/kg) diluted in DMSO. The control group mice were injected with complete Freund's adjuvant weekly for two times and did not receive treatment. Non-immunized mice (n = 5 per group) were treated either with simvastatin (5 mg/kg or 20 mg/kg or 40 mg/kg of simvastatin diluted in DMSO) or with DMSO.

RESULTS

Inflammation was observed in myositis groups with positive myositis-specific antibodies. Muscle strength dropped significantly after immunization. Immunized simvastatin 20 mg/kg treated group had significantly higher muscle strength versus non-treated myositis mice and versus other simvastatin doses. Besides, a trend toward higher serum Th17 percentage population was found in immunized non-treated mice, versus immunized simvastatin- treated mice, without significant difference.

CONCLUSION

Simvastatin at 20 mg/kg decreases the severity of myositis in experimental autoimmune myositis and is a candidate of being a disease-modifying agent in inflammatory myopathies.

Urging medical students to publish: Advantages, disadvantages and new challenges

As soon as they get accepted into medical school, students find themselves facing numerous expectations: coping with tremendous study burden, competing with others for the best rank, completing internships and participating in the race for publishing are only to name a few. This big juggle makes it hard for the medical student to focus on research. It is often easier to postpone publication and involvement in research to "later". In fact there are many advantages to publishing in the current publication system but there are many disadvantages as well. With the widespread of social media and open access systems, new challenges have arisen. The aim of this paper is to discuss the advantages and disadvantages of publishing in the current system while highlighting the new challenges that the students might need to overcome. Its aim is to provide medical students with information to enhance their understanding of the current publication system and thus most importantly, probe their desire to publish.

ALK-rearranged adenocarcinoma transformed to small-cell lung cancer: a new entity with specific prognosis and treatment?

Driving molecular mutations such as rearrangement of ALK and EGFR mutation is present in 5-10% of non-small-cell lung cancer. Tyrosine kinase inhibitors have shown good efficacy and thus become the standard of care. However, tumors have developed several resistance mechanisms against tyrosine kinase inhibitors, including transformation to small-cell lung carcinoma (SCLC). Transformation to SCLC after administration of anti-EGFR in EGFR-mutated adenocarcinoma has been well documented. Similarly, it appears that the same transformation happens in ALK-rearranged adenocarcinoma after the use of anti-ALK. In fact, to date eight cases have been reported in the literature. We aimed in this paper to focus on the characteristics, prognosis and treatment of these transformed SCLC.