The "Ram Effect": A "Non-Classical" Mechanism for Inducing LH Surges in Sheep

During spring sheep do not normally ovulate but exposure to a ram can induce ovulation. In some ewes an LH surge is induced immediately after exposure to a ram thus raising questions about the control of this precocious LH surge. Our first aim was to determine the plasma concentrations of oestradiol (E2) E2 in anoestrous ewes before and after the "ram effect" in ewes that had a "precocious" LH surge (starting within 6 hours), a "normal" surge (between 6 and 28h) and "late» surge (not detected by 56h). In another experiment we tested if a small increase in circulating E2 could induce an LH surge in anoestrus ewes. The concentration of E2 significantly was not different at the time of ram introduction among ewes with the three types of LH surge. "Precocious" LH surges were not preceded by a large increase in E2 unlike "normal" surges and small elevations of circulating E2 alone were unable to induce LH surges. These results show that the "precocious" LH surge was not the result of E2 positive feedback. Our second aim was to test if noradrenaline (NA) is involved in the LH response to the "ram effect". Using double labelling for Fos and tyrosine hydroxylase (TH) we showed that exposure of anoestrous ewes to a ram induced a higher density of cells positive for both in the A1 nucleus and the Locus Coeruleus complex compared to unstimulated controls. Finally, the administration by retrodialysis into the preoptic area, of NA increased the proportion of ewes with an LH response to ram odor whereas treatment with the α1 antagonist Prazosin decreased the LH pulse frequency and amplitude induced by a sexually active ram. Collectively these results suggest that in anoestrous ewes NA is involved in ram-induced LH secretion as observed in other induced ovulators

Recovery and prognostic value of myocardial strain in ST-segment elevation myocardial infarction patients with a concurrent chronic total occlusion

Objectives: Global left ventricular (LV) function is routinely used to assess cardiac function; however, myocardial strain is able to identify more subtle dysfunction. We aimed to determine the recovery and prognostic value of featuring tracking (FT) cardiovascular magnetic resonance (CMR) strain in ST-segment elevation myocardial infarction (STEMI) patients with a concurrent chronic total occlusion (CTO). Methods: In the randomized EXPLORE trial, there was no significant difference in global LV functio

The role of school nurses in adolescent mental health

Problématique : Les besoins en termes de santé mentale des personnes adolescentes ont augmenté, surtout depuis la pandémie de COVID-19. Les infirmières en santé scolaire sont des professionnelles de première ligne. Elles sont des actrices clés pour améliorer l’accès aux soins en santé mentale, surtout lorsqu’on considère que les jeunes passent la majorité de leur temps à l’école. Les infirmières ont notamment la responsabilité d’évaluer la condition physique et mentale et d’intervenir en fonction de celle-ci. Pourtant, particulièrement dans le domaine de la santé mentale, le rôle des infirmières est méconnu, et les données indiquent qu’il varie de manière importante entre les institutions et les régions. But : Ce projet de recherche a pour but de comprendre, de la perspective des infirmières scolaires elles-mêmes, le rôle qu’elles jouent en santé mentale auprès des personnes adolescentes de 14 ans et plus dans les écoles secondaires du Québec. Méthodologie : Une étude descriptive interprétative a été menée. La collecte de données s’est déroulée au moyen d’entretiens virtuels individuels semi-dirigés. Un échantillon de 15 infirmières scolaires de régions différentes du Québec a été obtenu. L’analyse comprend la codification des données puis un regroupement en thèmes en fonction de leurs similitudes ou de leurs différences. Résultats : Trois activités émergent, à la lumière des entretiens, pour décrire leur rôle en santé mentale : 1) repérer des signes cliniques de problèmes de santé mentale; 2) orienter vers des professionnels spécialisés en santé mentale; 3) promotion de la santé mentale par l’éducation sexuelle. Les influences sur l’exercice de leur rôle sont de deux natures, à la fois personnelles et organisationnelles. Conclusion : Ces résultats mettent en lumière le potentiel de l’infirmière scolaire d’être l’une des actrices principales auprès des personnes adolescentes en santé mentale dans les services de première ligne, et l’importance de développer des stratégies pour améliorer son rôle.Abstract : Introduction: The mental health needs of adolescents have been steadily increasing in recent years. School nurses can be a crucial frontline service to enhance access to mental health care, especially considering that young individuals spend most of their time in school. Nurses have the responsibility to assess physical and mental conditions and to intervene accordingly. However, particularly in the realm of mental health, the role of nurses is often underrecognized, and preliminary data indicates significant variation in their roles across institutions and regions. Objective: This research project aims to understand, from the perspective of school nurses themselves, the role they play in adolescent mental health care, specifically among those aged 14 and older in high schools in Quebec. Methodology: A descriptive interpretive study was conducted. Data collection involved individual semistructured virtual interviews. A sample of 15 school nurses from various regions of Quebec was obtained. Results: Three professional activities emerged from the interviews, delineating their role in mental health: 1) identification of clinical indicators of mental health problems; 2) referral to mental health professionals; 3) promotion of mental health through sexual education. Individual and organizational factors were found to influence the execution of their roles. Conclusion: These findings highlight the potential for nurses to be key players in adolescent mental health within frontline services and underscore the importance of developing strategies to enhance their role

Cytotoxic Activity of Some Triterpenoid Saponins

The present note deals with the cytotoxic activity of purified saponins of hedera helix and of saponins isolated from other plants ( Calendula officinalis, C. arvensis and Sapindus mukurossi with a view to the detection of possible structure-activity relationships. The most active compounds are the monodesmosides which show some degree of cytotoxicity at concentrations of 10 micrograms/ml and above. Among them, alpha- and beta-hederin are the most potent substances

Impact of Collateral Circulation on Survival in ST-Segment Elevation Myocardial Infarction Patients Undergoing Primary Percutaneous Coronary Intervention With a Concomitant Chronic Total Occlusion

This study sought to compare long-term clinical outcome in ST-segment elevation myocardial infarction (STEMI) patients with a concomitant chronic total occlusion (CTO) with well-developed versus poorly developed collaterals toward the CTO. In STEMI patients, presence of a CTO is associated with increased morbidity and mortality. CTOs are often (partially) perfused by collateral vessels. Therefore, when the infarct-related artery (IRA) is the main donor vessel for the collateral blood supply of the CTO, infarct size may increase significantly. Well-developed collaterals to the infarct related vessel have been associated with improved clinical outcome after STEMI. However, the impact of well-developed collaterals toward a concomitant CTO in STEMI patients is unknown. Consecutive STEMI patients with a CTO in a non-IRA presenting for primary percutaneous coronary intervention (PCI) were divided according to the presence of angiographic, well-developed (grade 2 to 3) or poorly developed collaterals (grade 0 to 1). Between 2000 and 2012 we included 413 STEMI patients with a single concomitant CTO. Well-developed collaterals to the CTO were present in 53%. Associated with poorly developed collaterals to the CTO were cardiogenic shock (hazard ratio [HR]: 1.8; 95% confidence interval [CI]: 1.11 to 3.07; p = 0.02), CTO located in the left circumflex artery (HR: 1.9; 95% CI: 1.00 to 3.43; p = 0.05), CTO diameter ≤2.5 mm (HR: 2.1; 95% CI: 1.07 to 4.12; p = 0.03), and CTO tapering (HR: 1.9; 95% CI: 1.21 to 2.85; p <0.001). Patients with well-developed collaterals to the CTO had a better 5-year survival compared to those with poorly developed collaterals (74% vs. 63%; p = 0.01). The presence of well-developed collaterals to the CTO was independently associated with improved survival (HR: 1.5; 95% CI: 1.03 to 2.10; p = 0.04). In STEMI patients with a CTO in a non-IRA, the presence of well-developed collaterals to the CTO is associated with improved surviva

Electrocardiographic changes after successful recanalization of a chronic total coronary occlusion. A systematic review and meta-analysis

Background: Observational studies suggest that in patients with a CTO successful recanalization is associated with better clinical outcome. This could be related to a reduction in the occurrence of arrhythmias, which may result from modifications of the hibernating myocardium in a CTO region. Methods and results: We aimed to evaluate the effect of CTO PCI on electrophysiological parameters, and conducted a systematic review and meta-analysis according to the PRISMA guidelines. MEDLINE and EMBASE were searched. Titles and abstracts identified by the search strategy were independently screened by two investigators. Data were extracted and used for meta-analyses where possible. In total, eight studies incorporating 467 patients were included in this review, evaluating the effect of successful CTO PCI on various ECG parameters. Three studies showed a significant decrease in mean QT dispersion of 17.46 ms [95% CI 10.62–24.30] after successful CTO PCI. QTc dispersion also decreased significantly, with a mean decrease of 18.74 ms [95% CI 11.53–25.94]. In one trial a significant decrease in Tp-e interval in leads V2 and V5, and a significant decrease in Tp-e/QT ratio in leads V2 and V5 post-CTO PCI were observed. Conclusions: This first systematic review and meta-analysis suggests that successful CTO PCI is associated with an immediate decrease in ECG parameters that reflect heterogeneity in depolarization and repolarization, which could lead to a reduction in the risk for ventricular arrhythmias and sudden cardiac death. We raise the hypothesis that hibernating myocardium in a CTO region may not be as deeply “in sleep” as one would assume