Depression and suicidal ideation in Mexican medical students during COVID-19 outbreak. A longitudinal study.

INTRODUCTION: The COVID-19 pandemic has been particularly difficult for populations at risk for mental health problems, such as healthcare professionals and medical students. In the present study, we evaluated the effect of the pandemic on mental health in a sample of Mexican medical students with and without a mental health diagnosis. METHOD: Longitudinal and descriptive study based on scales of suicidal ideation, depressive symptoms and risk of alcohol consumption, conducted in April and December 2020. RESULTS: Sample includes 247 medical students, 64.4% are women. Prevalence of depression increased between April and December from 19.84% to 40.08%. In the case of women from 23.67% to 42.60% (χ2 = 0.000) and in men from 11.54% to 34.62% (χ2 = 0.001). In April 16.92% of healthy students presented some sign of depression and in December the percentage increased to 40.80% (χ2 = 0.000). Regarding medicated students, the prevalence in April was 32.61% and in December it was 36.96% (χ2 = 0.662). In April, the medicated students with risk of suicidal ideation were 17 out of 46 (36.96%), compared to the students without a diagnosis of psychiatric illness were 29 out of 201 (13.43%) (χ2 = 0.000). For December, the non-medicated students at risk of suicidal ideation were 34 out of 201 (16.91%), and the medicated students were 12 out of 46 (26.09%) (χ2 = 0.149). CONCLUSIONS: The pandemic has increase the rate of depression in medical students, being more severe in women. Students under psychiatric treatment showed a higher prevalence of depression; however, the fact of being under treatment resulted in a protective factor for the increase in the prevalence of depression. It is important to deepen the understanding of the causes of depression and to disseminate among the university community the benefits of early detection and treatment of people with socio-emotional disorders.

Ovulation delay induced by blockade of the cholinergic system on dioestrus-1, is related to changes in dopaminergic activity of the preoptic anterior-hypothalamic area of the rat.

One hour after the injection of 100 mg/kg of atropine-sulphate at 1300 h of dioestrus-1, there was an abrupt increase of 17beta-oestradiol plasma level and a significant increase in dopaminergic neural activity in preoptic anterior-hypothalamic area, without changes in luteinizing hormone serum level, in comparison with the saline injected group. Animals injected with atropine-sulphate showed a second increase in dopaminergic neural activity in the preoptic anterior-hypothalamic at 1100 of dioestrus-2 (atropine-sulphate 0.471 +/- 0.7 vs. saline 0.241 +/- 0.03, p < 0.01). In this group of animals, the preovulatory surges of 17beta-oestradiol and luteinizing hormone occurred simultaneously at 1700 h of the expected day of oestrus; spontaneous ovulation was delayed until the expected day of dioestrus-1. Present results suggest that during dioestrus-1 there is a functional relationship between the cholinergic and dopaminergic systems in preoptic anterior-hypothalamic area, regulating the release of luteinizing hormone resulting in ovulation.

A less acidic human follicle-stimulating hormone preparation induces tissue-type plasminogen activator enzyme activity earlier than a predominantly acidic analogue in phenobarbital-blocked pro-oestrous rats.

Follicle-stimulating hormone (FSH) exists in multiple molecular forms. In both experimental animals and in humans the production and secretion of less acidic, short-lived FSH glycoforms significantly increase during the peri-ovulatory period. To gain further insights on the physiological role of these FSH variants, we analysed the ability of two FSH compounds, recombinant FSH (rFSH) and purified FSH from urinary origin (uFSH), (less acidic and acidic pattern of FSH charge isoform distributors respectively) to induce ovarian tissue-type plasminogen activator (tPA) enzyme activity in vivo. FSH produced by Chinese hamster ovary cells and highly purified uFSH were injected at 15:00 h on the pro-oestrous day into phenobarbital-blocked rats and the ovaries were analysed for tPA enzyme activity and tPA mRNA concentrations at different times after FSH injection. Induction of tPA enzyme activity by uFSH and rFSH showed distinct dynamics depending on the particular preparation administered. In animals treated with uFSH, maximum tPA enzyme activity was detected at 20:00 h, and maximum tPA mRNA concentrations were detected at 17:00 h. tPA enzyme activity induction by rFSH was at the maximum at 17:00 h, and maximum tPA mRNA concentration was at 16:00 h (P< 0.05 for uFSH versus rFSH). All animals in the uFSH- and rFSH-treated groups and none in phenobarbital-blocked, saline-treated controls ovulated. No significant differences were present in the number of ova shed by rats treated with uFSH or rFSH and spontaneously ovulating rats (10.7+/-1.7, 10.0+/-2.6 and 11.3+/-1.6 respectively). These data indicate that the increased biological activity exhibited by less acidic FSH glycovariants at the target cell level may compensate for the drawback imposed by their relatively short plasma half-life.