In this study, we have evaluated the ability of human satellite cells isolated from subjects aged from 5 days to 86 years to proliferate in culture. Cells were cultivated until they became senescent. The number of cell divisions was calculated by counting the number of cells plated in culture compared to the number of cells removed following proliferation. Telomere length, which is known to decrease during each round of cell division, has been used to analyze the in vitro replicative capacity and in vivo replicative history of human satellite cells at isolation. The rate of telomere shortening in myonuclei of these muscle biopsies was also examined. Our results show that both proliferative capacity and telomere length of satellite cells decreases with age during the first two decades but that the myonuclei of human skeletal muscle are remarkably stable because telomere length in these myonuclei remains constant from birth to 86 years. The lack of shortening of mean terminal restriction fragments (TRF) in vivo confirms that skeletal muscle is a stable tissue with little nuclear turnover and therefore an ideal target for cell-mediated gene therapy. Moreover, our results show that it is important to consider donor age as a limiting factor to obtain an optimal number of cells.
Our objective was to characterize both epidemiologically and clinically manifestations after severe scorpion envenomation and to define simple factors indicative of poor prognosis in children. We performed a retrospective study over 13 years (1990–2002) in the medical intensive care unit (ICU) of a university hospital (Sfax-Tunisia). The diagnosis of scorpion envenomation was based on a history of scorpion sting. The medical records of 685 children aged less than 16 years who were admitted for a scorpion sting were analyzed. There were 558 patients (81.5%) in the grade III group (with cardiogenic shock and/or pulmonary edema or severe neurological manifestation [coma and/or convulsion]) and 127 patients (18.5%) in the grade II group (with systemic manifestations). In this study, 434 patients (63.4%) had a pulmonary edema, and 80 patients had a cardiogenic shock; neurological manifestations were observed in 580 patients (84.7%), 555 patients (81%) developed systemic inflammatory response syndrome (SIRS), and 552 patients (80.6%) developed multi-organ failure. By the end of the stay in the ICU, evolution was marked by the death in 61 patients (8.9%). A multivariate analysis found the following factors to be correlated with a poor outcome: coma with Glasgow coma score ≤ 8/15 (odds ratio [OR] = 1.3), pulmonary edema (OR = 2.3), and cardiogenic shock (OR = 1.7). In addition, a significant association was found between the development of SIRS and heart failure. Moreover, a temperature > 39°C was associated with the presence of pulmonary edema, with a sensitivity at 20.6%, a specificity at 94.4%, and a positive predictive value at 91.7%. Finally, blood sugar levels above 15 mmol/L were significantly associated with a heart failure. In children admitted for severe scorpion envenomation, coma with Glasgow coma score ≤ 8/15, pulmonary edema, and cardiogenic shock were associated with a poor outcome. The presence of SIRS, a temperature > 39°C, and blood sugar levels above 15 mmol/L were associated with heart failure.
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