Teaching pre-clinical medical students remotely in Nigeria post Covid-19 pandemic: can past experiences shape future directions?

PURPOSE: Online teaching has gained popularity in recent years, but changes have been slower to implement in Lower or Medium Income Countries (LMIC). The aim of this research was to build upon educators' experiences of remote teaching during Covid-19 to inform the development of a blended learning approach for teaching pre-clinical subjects at the Faculty of Biomedical Sciences at Obafemi Awolowo University, Ile-Ife, Nigeria (OAU). METHODS: The Critical Incident Technique (CIT) was used in this exploratory study. Participants were invited to either complete an online qualitative questionnaire or take part in an online structured interview, which were hosted on Microsoft platforms. Data were obtained from eighteen educators and were analyzed using thematic analysis. RESULTS: Findings suggest that most educators (72%) continued to engage with remote teaching post-pandemic. All lab-based practical topics returned to being in-person, and teachers' experiences highlighted that a new blended learning approach should focus on asynchronized online teaching of didactic subjects. Five main themes captured educators' experiences and lessons learned regarding online teaching including: skills and training, teachers' motivation and attitudes, internet and connectivity, learners' behaviors, and socio-economic constraints. CONCLUSION: Findings provided additional evidence on the way in which educators in LMIC would like to build upon the positive aspects of online teaching and move towards a blended learning model. However, the implementation of such an approach should consider students' and faculty's needs and socio-economic constraints.

Memory state and hippocampal histomorphology in Wistar rat following monosodium glutamate-induced neurotoxicity; role of aqueous extract of Aloe Barbadensis

This study assessed the effect of varying doses of aqueous extract of Aloe barbadensis on the cellular changes of hippocampal cells, oxidative and memory state of Wistar rats following monosodium glutamate-induced neurotoxicity. Eighty Wistar rats (8 weeks) were randomly as-signed into 4 groups of 20 rats; Group 1 received 3 mL/kg of distilled water. Groups 2, 3 and 4 received 3 g/kg/day of MSG. In addition, groups 3 and 4 received 100 and 200 mg/kg/day of AB ex-tract respectively. Administration was done orally for 28 days in all groups. Five rats per group were sacrificed weekly over a 4-week period. Memory was assessed using radial arm maze on the last day of administration. Following brain harvest, one cerebral hemisphere was homogenized for oxidative state assessment, while the other was fixed in 10% neutral buffered formalin and stained with H&E for hippocampal histomorphology. Data obtained were analyzed using student t-test and p value < 0.05 was considered significant. Across the 4-week period, group 2 rats showed significant increase in time spent to identify baited arms, significant reduction in density of apparentlynormal neurons and oligodendrocyte in CA 1-3 regions of hippocampus, and significant increase in reduced glutathione when compared with other groups. However, no significant differences were noted between groups 1, 3 and 4 for the above stated parameters. The study concluded that MSG caused hippocampal neuronal and oligodendrocytes degeneration and impairment of memory. These anomalies are prevented by 100 and 200 mg/kg of Aloe barbadensis

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Assessment of the Effects of Graded Doses of Polyphenolic-Rich Fraction of Garcinia kola Seeds on Pituitary-Testicular Axis of Male Wistar Rats.

This study evaluated the ameliorative and prophylactic effects of 2 different doses of polyphenolic-rich fraction of Garcinia kola (PPRFGk) seeds on the histology and hormones of pituitary-testicular axis of male Wistar rats. Thirty-five male Wistar rats (150-200 g) were divided into 7 groups of 5 rats each. Groups I and II were given distilled water (0.5 mL/day) for 8 days followed by propylene glycol (0.2 mL/d) and 600 mg/kg of PPRFGk, respectively, for 21 days. Group III received sodium arsenate (8 days), left untreated for 21 days. Groups IV and V received sodium arsenate (20 mg/kg) for 8 days followed by PPRFGk (300 and 600 mg/kg, respectively) for 21 days. Groups VI and VII received PPRFGk (300 and 600 mg/kg, respectively) for 21 days followed by sodium arsenate (20 mg/kg) for 8 days. Rats were killed by cervical dislocation 24 hours after the last dose and their blood collected through cardiac puncture. Blood sera were assayed for the levels of follicle-stimulating hormone (FSH), luteinizing hormone (LH), and testosterone using immunoassay techniques. Histology of the pituitary gland and testes was carried out. A significant reduction was observed in the concentration of FSH in groups IV, V, VI, and VII in comparison with groups I and II. The concentrations of both LH and testosterone showed significant decreases in groups IV, V, VI, and VII in comparison with group I. Group III presented with the lowest serum hormonal concentrations. Photomicrographs of the pituitary gland revealed greatly reduced basophils in group III and mildly reduced basophils in groups IV, VI, and VII in comparison with groups I and II. Group V revealed hypercellularized and distorted basophils. Photomicrographs of the testes showed detachment of the seminiferous tubules from the basement membrane and disruption of the interstitial space which was worse in group III, moderate in groups V and VI, and mild in group VII. In conclusion, PPRFGk effected a dose-dependent reversal and prevention of the perturbations caused by arsenate in rats.

Cortical Oligodendrocytes in Kaolin-Induced Hydrocephalus in Wistar Rat: Impact of Degree and Duration of Ventriculomegaly.

BACKGROUND: Oligodendrocytes are critical to the function of the brain. They generate the myelin sheath which ensures saltatory conduction, which is a more energy saving and efficient means of axonal impulse transmission. Ventriculomegaly results in neuronal degeneration and astrogliosis. PURPOSE: The effect of the degree of ventriculomegaly on oligodendrocyte in kaolin-induced hydrocephalus and the timeline have not been extensively documented, hence this study. METHODS: A total of 81 rats that were 3 weeks old were divided into 4 groups each consisting of control and experimental subgroups. Kaolin suspension was intracisternally injected to induce hydrocephalus and the animal sacrificed post-induction at 1, 2, 3, and 4 weeks. Two 1-mm-thick coronal slices at optic chiasma level were fixed in 10% buffered formal-saline and Karnovsky's fixative for light and transmission electron microscopy (TEM), respectively. The former slices were processed and stained with hematoxylin and eosin for glial density, cortical thickness, and oligodendrocyte evaluations. Subcortical white matter region of the latter were processed by conventional techniques for TEM. RESULTS: Compared with their corresponding control rats, thickness of the dorsolateral cortex was significantly reduced across the 2-4 week post-induction (WPI), glial density was significantly increased in the mild and moderate ventriculomegaly subgroups 1 WPI but only in mild ventriculomegaly subset 2 WPI. In the 4 WPI group, there was significant increase in glial density across the 3 ventriculomegaly subsets. Early hydropic changes of oligodendrocytes were noted in the inner pyramidal layer mostly in the 4 WPI experimental rats. Dilation of the endoplasmic reticulum precedes that of mitochondria, while mitochondrial crista disruption was noted in the 3 and 4 WPI rats. The nuclear membrane of the oligodendrocytes was progressively deformed from the 2nd to 4th WPI. CONCLUSION: This study reported degenerative changes of oligodendrocytes and its organelles in kaolin-induced hydrocephalus. Degeneration was worse with duration and in the deep cortical layers.

Myelin Sheath Injury in Kaolin-Induced Hydrocephalus: A Light and Electron Microscopy Study.

BACKGROUND: In hydrocephalus, the impairment of cognitive and motor functions is thought to be partly due to injury to the myelin sheath of axons in the central nervous system. The exact nature of this injury is not completely understood. METHODS: We induced hydrocephalus in 3-week-old rats with an intracisternal injection of kaolin suspension (0.04 ml of 200 mg/ml) and examined paraffin and ultrathin sections of the subcortical white matter from coronal slices of the cerebrum obtained at the level of the optic chiasm after sacrifice at weekly intervals for 4 weeks. RESULTS: Over time, there was a progression of injury to the myelin sheath consisting of attenuation, lamella separation and accumulation of myelin debris, focal degeneration, and the appearance of casts and loops. CONCLUSION: The results suggest that myelin injury in kaolin-induced hydrocephalus progresses with the duration and severity of ventriculomegaly.