Influence of sexual maturity and gonadectomy on cardiac electrical activity in male and female rabbits

Es bien conocida la existencia de diferencias en la actividad eléctrica cardíaca asociadas al sexo. Si bien estas diferencias habitualmente se relacionan al efecto de la madurez y de las hormonas sexuales gonadales, todavía existen controversias al respecto. El objetivo de este trabajo fue evaluar el efecto que la madurez sexual y la castración producen sobre los distintos parámetros del electrocardiograma de superficie y de la duración de los potenciales de acción (DPA). Se utilizaron conejos jóvenes (menores de un mes de edad) y adultos (mayores de seis meses de edad). Las diferencias obtenidas en las hembras se observan en la repolarización tardía, mientras que en los machos ocurren en la repolarización temprana. Existiría una relación entre las diferencias observadas en la duración desde el pico máximo hasta el fin de la onda T (Ttpf) y las observadas en la DPA al 90% de la repolarización (DPA90) en las hembras, mientras que en los machos la relación existe entre la duración desde el punto J hasta el pico máximo de la onda T (JTp) y la DPA al 30 y 50% de la repolarización (DPA30 y DPA50). Si bien existen diferencias que podrían ser debidas a factores hormonales otras serían debidas a factores no hormonales.Sex-associated differences in cardiac electrical activity have already been documented. Even though these differences are usually associated with the effect of maturity and sex hormones, there are still some controversial points to this respect. The aim of this study was to evaluate the effects of maturity and gonadectomy on the different parameters of surface electrocardiogram and the duration of the action potential in young and adult rabbits. The differences obtained in females were observed in late repolarization, whereas in males took place in early repolarization. There was a relationship between the differences observed in the duration from the peak to the end of the T wave and those observed in the duration of the action potential to 90% of repolarization in females, whereas in males the relationship exists between the duration from the point J to the peak of the T wave and the duration of the action potential at 30 and 50% of repolarization. Differences could be related to hormonal or non-hormonal factors.Fil: Eizikovits, Gabriela Yael. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Médicas; ArgentinaFil: Casal, Carolina. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Médicas; ArgentinaFil: Arini, Pedro David. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Saavedra 15. Instituto Argentino de Matemática Alberto Calderon; ArgentinaFil: Bertran, Guillermo Claudio. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Médicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Smoking in Systemic Sclerosis: a Longitudinal European Scleroderma Trials and Research Group Study

Objective: Data on the role of tobacco exposure in systemic sclerosis (SSc; scleroderma) severity and progression are scarce. We aimed to assess the effects of smoking on the evolution of pulmonary and skin manifestations, based on the European Scleroderma Trials and Research group database. Methods: Adult SSc patients with data on smoking history and a 12\u201324-month follow-up visit were included. Associations of severity and progression of organ involvement with smoking history and the Comprehensive Smoking Index were assessed using multivariable regression analyses. Results: A total of 3,319 patients were included (mean age 57 years, 85% female); 66% were never smokers, 23% were ex-smokers, and 11% were current smokers. Current smokers had a lower percentage of antitopoisomerase autoantibodies than previous or never smokers (31% versus 40% and 45%, respectively). Never smokers had a higher baseline forced expiratory volume in 1 second/forced vital capacity (FEV1/FVC) ratio than previous and current smokers (P < 0.001). The FEV1/FVC ratio declined faster in current smokers than in never smokers (P = 0.05) or ex-smokers (P = 0.01). The baseline modified Rodnan skin thickness score (MRSS) and the MRSS decline were comparable across smoking groups. Although heavy smoking (>25 pack-years) increased the odds of digital ulcers by almost 50%, there was no robust adverse association of smoking with digital ulcer development. Conclusion: The known adverse effect of smoking on bronchial airways and alveoli is also observed in SSc patients; however, robust adverse effects of smoking on the progression of SSc-specific pulmonary or cutaneous manifestations were not observed. \ua9 2018, American College of Rheumatolog