Neurotrophic Factor Mediated Neurorestorative Effect of Pongamia pinnata Against Transient Cerebral Hypoperfusion and Reperfusion in Rats: Preliminary Histological and Molecular Level Evidence / Efecto Neurorestaurador Mediado por Factor Neurotrófico de Pongamia pinnata Contra la Hipoperfusión y Reperfusión Cerebral Transitoria en Ratas: Evidencia Preliminar de un Estudio a Nivel Histológico y Molecular

SUMMARY: Stroke is the leading cause of acquired physical disability in adults and second leading cause of mortality throughout the world. Treatment strategies to curb the effects of stroke would be of great benefit. Pongamia pinnata is a recent attraction in medicine, owing to its abundant medicinal benefits with minimal side effects. The present study aimed to examine acute and subacute effect of Pongamia pinnata leaf extract on transient cerebral hypoperfusion and reperfusion (tCHR) in Wistar rats. 24 adult Wistar rats (12 each for acute and subacute study) were divided in to four groups each viz normal control group, tCHR + NS group, tCHR + 200mg/kg bw and tCHR + 400mg/kg bw groups. Cerebral ischemia induction was carried out by bilateral common carotid artery occlusion and reperfusion. Ethanolic extract of Pongamia pinnata leaves were orally administered for 7 days and 21 days after the surgical procedure for acute and subacute study respectively. Behavioural analysis, histological assessment, and estimation of mRNA levels of HIF-1, GDNF, BDNF and NF-kB were performed. In both acute and subacute study, there was significant improvement in the beam walking assay, neuronal count, decreased neuronal damage in histological sections and higher mRNA expression of BDNF and GDNF in the treatment groups. There was no significant difference in the expression of HIF1 and NF-kB. Thus, Pongamia pinnata has excellent neurorestorative property reversing many of the effects of ischemic stroke induced by tCHR in rats with the underlying mechanism being an improvement in the expression of neurotrophic factors GDNF and BDNF.

El ataque cerebrovascular es la principal causa de discapacidad física adquirida en adultos y la segunda causa de mortalidad en todo el mundo. Las estrategias de tratamiento para frenar los efectos del ataque cerebrovascular serían de gran beneficio. Pongamia pinnata es una atracción reciente en la medicina, debido a sus abundantes beneficios medicinales con mínimos efectos secundarios. El presente estudio tuvo como objetivo examinar el efecto agudo y subagudo del extracto de hoja de Pongamia pinnata sobre la hipoperfusión y reperfusión cerebral transitoria (tCHR) en ratas Wistar. Se dividieron 24 ratas Wistar adultas (12 cada una para el estudio agudo y subagudo) en cuatro grupos, el grupo control normal, el grupo tCHR + NS, los grupos tCHR + 200 mg/kg de peso corporal y tCHR + 400 mg/kg de peso corporal. La inducción de la isquemia cerebral se llevó a cabo mediante oclusión y reperfusión bilateral de la arteria carótida común. El extracto etanólico de hojas de Pongamia pinnata se administró por vía oral durante 7 días y 21 días después del procedimiento quirúrgico para estudio agudo y subagudo respectivamente. Se realizaron análisis de comportamiento, evaluación histológica y estimación de los niveles de ARNm de HIF-1, GDNF, BDNF y NF-kB. Tanto en el estudio agudo como en el subagudo, hubo una mejora significativa en el ensayo de desplazamiento del haz, el recuento neuronal, una disminución del daño neuronal en las secciones histológicas y una mayor expresión de ARNm de BDNF y GDNF en los grupos con tratamiento. No hubo diferencias significativas en la expresión de HIF1 y NF-kB. Por lo tanto, Pongamia pinnata tiene una excelente propiedad neurorestauradora que revierte muchos de los efectos del ataque cerebrovascular isquémico inducido por tCHR en ratas, siendo el mecanismo subyacente una mejora en la expresión de los factores neurotróficos GDNF y BDNF.

Does Academic Performance Affect the Perceived Value of Mentorship, and Mentor s Influence on Student s Satisfaction? A Cross Sectional Study

An effective mentorship can greatly help medical students in achieving personal and professional success, and satisfaction. Mentorship efforts are therefore gaining increasing importance in medical education. It is important to make a realistic appraisal of factors that can affect the outcome of mentorship exercise, so that specific improvement in mentorship strategy can be made. Academic performance correlates with students’ ability to handle learning stress, and their professional and personal competence. This study aims at identifying the perceived value of mentorship in medical students. MethodsA cross-sectional survey was conducted among graduate medical students at the College of Medicine, Majmaah University, in October 2019. The mentees completed an anonymous questionnaire about the perceived quality of the mentorship. Academic performance was evaluated from Garde Point Average (GPA), whether the student has repeated one or more years in the college, and the number of academic papers published by the student. Kruskal–Wallis test was used to determine significant differences among groups. Two-tailed p-value was used to evaluate the statistical significance. ResultsThe questionnaire was sent to 337 mentees. The response rate was 67.7 % and the average age of mentees was 21.9 ± 1.4 years. 276 (98 %) mentees were unmarried and 171 (61 %) were men. 78 (27.7 %) mentees had a GPA of 4.5 - 5. 76 (27.0 %) mentees repeated one or more years in the college. 214 (75.9 %) mentees did not have any publication. More men than women had one or more published papers (men 29.2 % vs women 15.2 % , p = 0.04), The median score of Mentorship Relationship Structure (MRS) for the GPA 2 - 2.5 was 8 (IQR = 15) and it increased to 25 (IQR = 12.2) in the group with GPA 4.5 - 5 (p = 0.004). On MRS, there was no effect of repeating a year in college or the number of papers published (both, p > 0.05). ConclusionsThe mentees with extremely low and high GPA can have different perceived quality of the mentorship. The mentorship exercise should be customized to address the specific needs and motivational status of mentees with low and high GPA.