Social media for students' sleep health promotion - a health intervention report during COVID -19.

The COVID-19 pandemic has affected sleep health. Students' sleep health is essential for the performance of neuro-cognitive processes, as well as mental and physical balance. We assume the COVID19 pandemic has modified some sleep habits by prompting environmental and social interaction changes. In this study we surveyed a sample of 300 Brazilian students, with internet access, resident in the Federal District. They completed a questionnaire over two weeks in March 2020, i.e. the second and third week of the social isolation policy enacted in the Federal District due to COVID19. Valid responses from students aged18-24 years were analyzed. The sample was mostly female; 76,3% reported somnolence during the day, 70,2% anxiety and 87,8% worse sleep associated with stress and/or anxiety, which indicated the variables for an educational health intervention design in this context. Further, 53.2% made no effort to avoid screens before sleeping; 73.9% to avoid using the bed for work or watching television and 83.1% to avoid consuming heavy foods before sleeping. We then created an Instagram profile, @comodormimos, which focused on the main sleep issues revealed by participants in the survey. Posts on the profile were based on sleep-related subjects: sleep processes, sleep hygiene practices for students; sleep stages, function and regulation; and sleep-wake circadian rhythms. The profile gained 307 followers, mostly women (61,7%), 18-24 years old. We concluded that the Covid-10 pandemic period increased harmful sleep behavior in students. Further studies are needed to understand the impact of the COVID-19 pandemic on student sleep health.

The impact of obesity on venous insufficiency.

Association between chronic venous disease and obesity has recently been studied, with indications that it may worsen in obese patients. The aim of study was to correlate clinical classes of chronic venous disease according to Clinical Etiology Anatomy Pathophysiology (CEAP) classification and body mass index, as well as to compare the severity of chronic venous disease in obese and nonobese patients. This retrospective cross-sectional prevalence study was conducted at the Maringá State University and Belczak Vascular Center along a period of 2 years, consisting of a random sample of 482 patients with complaints compatible with chronic venous disease. Data obtained from patient's files included gender, age, weight and height (for calculating body mass index), and clinical class (C) of chronic venous disease according to CEAP classification. Statistical analysis included Spearman's correlation coefficient, Chi-square test (for comparing frequencies), and Student's t-test (for comparing means). Significant positive correlation between body mass index and clinical classes was established for women (0.43), but not for men (0.07). Obesity (body mass index : ≥ : 30.0) was significantly more frequent in patients with chronic venous disease in clinical classes 3 (p < 0.001) and 4 (p = 0.002) and less frequent in patients with chronic venous disease in clinical class 1 (p < 0.001). This study evidenced significant correlation between body mass index and clinical classes of chronic venous disease in women, but not in men. It also corroborated the negative impact of obesity on the clinical severity of chronic venous disease.

Tracing the origin of an outbreak of methicillin-resistant Staphylococcus aureus infections in a Portuguese hospital by molecular fingerprinting methods.

Seventy-six methicillin-resistant Staphylococcus aureus (MRSA) isolates were collected from July 1992 to May 1995 at a 400-bed district hospital in the northeast of Portugal. During the second half of the surveillance period, in July of 1994, an outbreak was detected in the orthopedic ward. Thirty-three (out of the 76) MRSA strains were recovered only in this ward during the outbreak period. All strains were characterized by a variety of genomic fingerprints. Hybridization of ClaI and SmaI restriction digests with the mecA- and Tn554-specific DNA probes was used to identify polymorphism and determine chromosomal location of these determinants, and pulsed-field gel electrophoretic analysis of SmaI digests was used to determine chromosomal backgrounds. All strains recovered during the outbreak in the orthopedic ward were found to belong to a single clone that carried the mecA polymorph I, Tn554 type E in a macrorestriction background called H (clone I::E::H1), which was identified in 18 patients, and 5 health care personnel and from a fomite sample, and was traced to a single transfer patient admitted to the hospital at the beginning of the outbreak. The new clone I::E::H1 differed only in the macrorestriction profile from the MRSA clone previously dominant in this hospital, known as Iberian epidemic clone I::E::A, which has already been identified in several Spanish and Portuguese hospitals.

Annexin V binding to the outer leaflet of small unilamellar vesicles leads to altered inner-leaflet properties: 31P- and 1H-NMR studies.

Calcium-dependent binding to phospholipid membranes is closely associated with annexin functional properties. In these studies, 31P- and 1H-nuclear magnetic resonance (NMR) experiments have been performed to study the effects of binding of recombinant rat annexin V to sonicated small unilamellar vesicles (SUVs). High-resolution 31P-NMR spectra of SUVs containing mixtures of synthetic phosphatidic acid (PA) and phosphatidylcholine (PC) show resolvable resonances corresponding to the inner-leaflet PA, outer-leaflet PA, and PC phosphoryl groups. When annexin binding occurs, the outer-leaflet PA 31P resonance shifts while that of PC is unaffected, consistent with selective binding of the protein to the phosphoryl moiety of the PA component. Further, annexin V binding to membrane outer-leaflet phospholipids has a measurable effect on inner-leaflet phospholipids of intact vesicles. 1H-NMR T1 relaxation measurements of SUVs containing acyl-chain-perdeuterated PC show no effects on the PA hydrocarbon-chain segmental motions upon annexin binding. Circular dichroism measurements indicate that the protein does not undergo a significant conformational change upon binding to the vesicles. The observed NMR changes do not correspond to proton or calcium gradients, nor to lateral segregation of extended patches of homogeneous phospholipids. The combined evidence suggests that selective, peripheral annexin-membrane interactions influence the environment of the inner vesicular surface. The mechanism proposed is a protein-induced change in vesicle morphology that corresponds to reduced curvature.

Effect of bilateral denervation of the immature rat testis on testicular gonadotropin receptors and in vitro androgen production.

We have studied the effect of superior spermatic nerve (SSN) section on testicular gonadotropin receptors and in vitro androgen production by immature rat testis. Bilateral testicular denervation had no effect on testicular weight, serum androgens, LH, FSH and PRL levels. Denervation resulted in a significant inhibition of hCG stimulated in vitro androgen production. A reduction in the number of testicular LH receptors was observed after SSN section, while FSH binding sites remained unchanged. These results indicate that the number of LH receptors and testicular steroidogenic response to hCG are influenced by nerves reaching the testis.

Coexistence of gamma-aminobutyric acid type A and type B receptors in testicular interstitial cells.

The existence of specific gamma-aminobutyric acid (GABA)ergic receptors in testicular interstitial cells was investigated in the present study. Specific binding of [3H]GABA to interstitial cell membranes was found to be time- and temperature-dependent and varied according to Ca2+ concentration present in the incubation medium. We analyzed the ability of different GABAergic agonists and antagonists to displace the bound radioactivity. In the absence of Ca2+ (1 mM EDTA), GABA and the GABAergic agonist isoguvacine displaced the bound radioactivity. When the radioligand assay was performed in the presence of 2.5 mM CaCl2, the [3H]GABA specifically bound increased twofold. Under such conditions, the specific GABAergic agonist baclofen, as well as GABA and isoguvacine, displaced the [3H]GABA bound. Saturation analysis revealed the presence of a population of GABAA binding sites with a KD value of 45.2 nM and a maximal number of binding sites of 57.4 fmol/mg of protein. The maximal binding increased on addition of 2.5 mM CaCl2 to 102 fmol/mg of protein, indicating the existence of a second population of GABAergic receptors, i.e., type B, with essentially the same affinity. In addition, the incubation of testicular interstitial cells with GABA and baclofen resulted in an increase in androgen production. These results support a functional role of GABA in the neuroendocrine control of the male gonad.

Effect of long term diazepam administration on testicular benzodiazepine receptors and steroidogenesis.

We evaluated the effect of acute and chronic diazepam administration on testicular peripheral type benzodiazepine receptors (PBZD-R), serum testosterone and LH levels and the "in vitro" androgen production in response to Ro 5-4864, a PBZD-R agonist. The chronic diazepam treatment induced a significant fall in plasma testosterone concentration while LH levels remained unchanged. The number of PBZD-R was reduced by 37% and low concentrations (10(-8)-10(-6) M) of Ro 5-4864 failed to stimulate "in vitro" androgen production. The acute diazepam administration caused a significant increase in plasma testosterone levels while no changes were observed in LH concentrations and testicular PBZD-R. These results further suggest a modulatory role of PBZD-R on testicular steroidogenic activity.

Catecholamine distribution in adult rat testis.

Catecholamine distribution in the adult rat testis was examined using a sensitive radioenzymatic method. Norepinephrine was present in the capsule and the interstitial fluid, in higher concentrations than dopamine, while in the interstitial cell preparations only norepinephrine was found. Epinephrine was undetectable in all testicular compartments investigated. No catecholamines were found in the seminiferous tubules. Testicular denervation caused a significant decrease in capsular catecholamines, confirming the neural origin of these amines.

Serotonergic innervation of the rat testis.

The presence of 5-hydroxytryptamine (5-HT) was determined by h.p.l.c. in perchloric extracts of each isolated compartment of the adult rat testis. The testicular capsule, interstitial cells and interstitial fluid contained 5-HT, but 5-HT was not detected in the tubular compartment. In a group of adult rats, one testis was unilaterally denervated, and the contralateral testis used as control. The superior spermatic nerve, arising from the renal plexus, was excised and 1 week after surgery 5-HT content was measured in the capsule and interstitial fluid of both testes. Denervation caused a significant fall (34%) in 5-HT content. These results indicate that at least part of the testicular 5-HT derives from a serotonergic innervation of the gonad.

Effect of GABA and benzodiazepines on testicular androgen production.

We have evaluated the effect of Ro5-4864, a selective probe to label peripheral type benzodiazepine receptor, on "in vitro" testicular androgen production. Decapsulated testes from adult rats showed a significant increase in the basal and hCG-stimulated testosterone secretion into the medium in response to 10(-5) M, 10(-6) M, and 10(-7) M Ro5-4864. In addition, we have studied the changes in testicular GABA content at three different ages and we found its highest concentration at 31 days of age. When we evaluated the effect of GABA on "in vitro" androgen production at different stages of gonadal maturation we observed that the highest concentration of GABA (10(-6) M) was able to modify the basal and hCG-stimulated androgen production from adult (60 days) and pubertal (45 days) testes. In addition, when prepubertal testes (31 days) were incubated under basal conditions, 10(-6) M GABA induced a significant increment of androstanediol production, while the stimulatory effect of hCG was reduced in the presence of the same GABA concentration. The present results suggest that GABA plays a physiological role in the regulation of rat testicular androgen production depending on the stage of sexual maturation.