Relation between energy metabolism, glycolysis, noradrenaline release and duration of ischemia

We studied the effect of 12-36 min of global ischemia followed by 36 min of reperfusion in Langendorff perfused rabbit hearts (n = 26). Metabolism was determined in terms of peak and total release of purines (adenosine, inosine, hypoxanthine), lactate and noradrenaline during reperfusion; and myocardial content of nucleotides (ATP, ADP, AMP), glycogen and noradrenaline at the end of reperfusion. An inverse relationship (r = -0.79) existed between duration of ischemia and developed pressure post-ischemia. Early during reperfusion, after 12 min of ischemia, the purine concentration (peak release) increased 100x (p < 0.01), that of lactate and noradrenaline 10x (p < 0.05). Total purine release rose with progression of the ischemic period (30x after 36 min of ischemia; p < 0.01), concomitant with a reduction in nucleotide content. Lactate release was independent from the duration of ischemia, although glycogen had declined by 30\% (p < 0.01) after 36 min of ischemia. The acid insoluble glycogen fraction, which presumably contains proglycogen, increased substantially during short-term ischemia. Peak noradrenaline increased 100x, and 200x, (p < 0.05) after 24 and 36 min of ischemia, respectively. Total noradrenaline release due to various periods of ischemia mirrored its peak release. Function recovery was inversely related to total purine and noradrenaline efflux (both r = -0.81); it correlated with tissue nucleotide content (r = 0.84). In conclusion, larger amounts of noradrenaline are released only after a substantial drop in myocardial ATP. During severe ischemia ATP consumption more than limited ATP production by anaerobic glycolysis, is a key factor affecting recovery on subsequent reperfusion. In contrast to lactate efflux, purine and noradrenaline release are useful markers of ischemic and reperfusion damage

PERSPECTIVAS DOS/AS FILHOS/AS DE AGRICULTORES EM RELAÇÃO AO SEU FUTURO PROFISSIONAL: ESTUDO DE CASO DE COMUNIDADES RURAIS DE NOVA VENEZA - SC

O presente artigo é uma investigação sobre a perspectiva dos jovens rurais quanto ao seu futuro profissional. A pesquisa foi realizada na Escola Julieta Torres Gonçalves no município de Nova Veneza-SC, distrito de São Bento Baixo. A metodologia tem abordagem predominantemente quantitativa

Sex differences in arterial hypertension.

There is strong evidence that sex chromosomes and sex hormones influence blood pressure (BP) regulation, distribution of cardiovascular (CV) risk factors and co-morbidities differentially in females and males with essential arterial hypertension. The risk for CV disease increases at a lower BP level in females than in males, suggesting that sex-specific thresholds for diagnosis of hypertension may be reasonable. However, due to paucity of data, in particularly from specifically designed clinical trials, it is not yet known whether hypertension should be differently managed in females and males, including treatment goals and choice and dosages of antihypertensive drugs. Accordingly, this consensus document was conceived to provide a comprehensive overview of current knowledge on sex differences in essential hypertension including BP development over the life course, development of hypertension, pathophysiologic mechanisms regulating BP, interaction of BP with CV risk factors and co-morbidities, hypertension-mediated organ damage in the heart and the arteries, impact on incident CV disease, and differences in the effect of antihypertensive treatment. The consensus document also highlights areas where focused research is needed to advance sex-specific prevention and management of hypertension

Modelling survival : exposure pattern, species sensitivity and uncertainty

The General Unified Threshold model for Survival (GUTS) integrates previously published toxicokinetic-toxicodynamic models and estimates survival with explicitly defined assumptions. Importantly, GUTS accounts for time-variable exposure to the stressor. We performed three studies to test the ability of GUTS to predict survival of aquatic organisms across different pesticide exposure patterns, time scales and species. Firstly, using synthetic data, we identified experimental data requirements which allow for the estimation of all parameters of the GUTS proper model. Secondly, we assessed how well GUTS, calibrated with short-term survival data of Gammarus pulex exposed to four pesticides, can forecast effects of longer-term pulsed exposures. Thirdly, we tested the ability of GUTS to estimate 14-day median effect concentrations of malathion for a range of species and use these estimates to build species sensitivity distributions for different exposure patterns. We find that GUTS adequately predicts survival across exposure patterns that vary over time. When toxicity is assessed for time-variable concentrations species may differ in their responses depending on the exposure profile. This can result in different species sensitivity rankings and safe levels. The interplay of exposure pattern and species sensitivity deserves systematic investigation in order to better understand how organisms respond to stress, including humans

Clinical Significance of Serum Biomarkers in Pediatric Solid Mediastinal and Abdominal Tumors

Childhood cancer is the leading cause of death by disease among U.S. children between infancy and age 15. Despite successes in treating solid tumors such as Wilms tumor, disappointments in the outcomes of high-risk solid tumors like neuroblastoma have precipitated efforts towards the early and accurate detection of these malignancies. This review summarizes available solid tumor serum biomarkers with a special focus on mediastinal and abdominal cancers in children

Temporal relations of the endocrine response to hypotension with sodium nitroprusside.

Sodium nitroprusside was infused intravenously for 10 minutes in normal men, reclining at 45 degrees, in a dose sufficient to decrease the arterial pressure by 10 mmHg. The effect on a variety of plasma hormones was measured during the infusion and for 20 minutes afterwards. The heart rate increased to a maximum of 149\%. Norepinephrine rose to a maximum of 196\% in 5 minutes. Epinephrine reached a peak of 207\% after 10 minutes. Plasma renin activity reached a peak of 449\% at 10 minutes. Aldosterone did not change during the infusion, but increased to a maximum of 145\% 10 minutes later. Vasopressin increased sharply at the end of the infusion to 893\% and then rapidly decreased. Corticotropin, prolactin and growth hormone started to increase toward the end of the infusion, but reached their maxima during recovery. Corticotropin (225\%) and prolactin (288\%) peaked 10 minutes after the infusion, while growth hormone (414\%) appeared still to be rising 20 minutes after the end of the infusion. Cortisol also rose progressively during recovery to a level of 138\%. No significant changes were seen in the concentrations of insulin, glucagon, atrial natriuretic peptide, bombesin or neurotensin

Temporal relations of the endocrine response to exercise.

We have followed the hormonal response to exercise in twelve normal males cycling at a constant moderate load for ten minutes. Plasma concentrations of a variety of hormones were measured at set times before and during exercise and for twenty minutes afterward. The plasma concentration of norepinephrine and epinephrine and plasma activity of renin rose to a maximum at the end of exercise and then declined. The plasma concentrations of neurotensin and atrial natriuretic peptide followed a similar course. Plasma vasopressin rose to a peak at the end of exercise and then fell transiently below the initial value ten minutes after exercise. The plasma concentrations of aldosterone, prolactin and adrenocorticotropin increased during exercise but continued to do so, reaching a peak at ten minutes after exercise. Plasma growth hormone increased during exercise and continued to increase throughout the period of twenty minutes' recovery. Cortisol did not change during exercise but rose progressively during the recovery period. Plasma concentrations of glucagon did not change while that of insulin decreased during exercise. The plasma concentration of bombesin slowly increased during exercise and declined during recovery, reaching a basal value 10 minutes later