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J Peralta

Publications and source records attributed to J Peralta.

14 recordsLinked to original sources
PubMed1998

[Shock: concepts for a definition].

The shock syndrome has been classically considered as a consequence of both decreased tissue perfusion and O2 supply; however, in some types of shock like septic or traumatic ones, regional blood flows may be increased. A decade ago, mitochondrial alterations consistent with uncoupling of oxidative phosphorylation were reported in either endotoxemic or hemorrhagic experimental shock or in humans. Recently, the discovery of nitric oxide (NO) and its increase in the shock state, has opened new perspectives in the understanding of this problem. Nitric oxide produces vasodilatation and, at the same time, increases the mitochondrial production of O2 active species like superoxide anion. Both radicals react to form a strong oxidant that is able to nitrate the phenolic rings of proteins: peroxynitrite. This effect leads to the impairment of the activities of different mitochondrial enzymes like succinate dehydrogenase and ATPase and the mitochondrial function and finally, to decreased energy levels and to multiorgan failure. The increase in NO release is due to the effects of circulating peptides and of increased adhesion of neutrophils to the endothelium and to the positive effects of inflammatory mediators like TNF-alpha and cytokines on inducible NOS (iNOS) expression in endothelium and tissues. It is suggested that the shock state is the consequence of an imbalance between NO and O2 and their metabolites.

Adenosine Triphosphatases↗
PubMed1996

Oxidative stress in rodent closed duodenal loop pancreatitis.

CONCLUSION: Production of excited oxygen species is earlier in the liver than in the pancreas and could contribute to damage in a reflux model. Treatment with SOD could attenuate 59% light emission in pancreas, but did not modify serum enzyme levels or pancreatic edema, resulting as an insufficient isolated therapy. Unexpectedly, it was found an increased plasma antioxidant capacity that was related to total bilirubin levels, and declined at late stages probably denoting other circulating antioxidant consumption. BACKGROUND: Oxidative stress has been shown to play a role in different models of acute pancreatitis, although it has not been studied in the severe necrohemorrhagic model produced by closed duodenal loop pancreatitis. METHODS: We studied Sprague Dawley female rats in two groups: a closed duodenal loop pancreatitis group and a control, sham-operated group. In order to evidence the oxygen excited species production, in situ spontaneous chemiluminescence from living and naturally perfused pancreas and liver was measured at 0, 0.5, 1.5, 3, 6, 12, and 24 h after the duodenal ligature. Blood pancreatic amylase and aminotransferases levels were determined as expression of tissue damage in pancreas and liver. At the same time, plasma antioxidant capacity was measured by the peroxyl radical trapping capability of plasma samples compared to that of Trolox (synthetic analog of vitamin E), and results are expressed as Trolox equivalence. Bovine superoxide dismutase (SOD) was administered to attenuate oxygen free radicals activity at the beginning of the peroxidation chain and also as a therapeutic tool. RESULTS: The experimental procedure induced a severe pancreatitis, as evidenced by pancreatic enzymes that rose markedly in the early hours of disease and remained heightened throughout the experiment. The results show early light emission from the liver at 3 h and peak levels at 12 h, whereas in the pancreas, luminescence increased at 6 h and doubled later at 12 h, both returning to control levels at 24 h.

Acute Disease↗
PubMed1994

Oxidative stress in muscle and liver of rats with septic syndrome.

Sepsis, as infection associated to systemic manifestations, was produced in rats by cecal ligation and double perforation. Sham-operated rats were used as controls. The spontaneous chemiluminescence of rat adductor muscle and liver were measured at 6, 12, 24, and 30 h after the surgical procedure. Muscle chemiluminescence showed a maximal increase of about twofold (control emission 10 +/- 1 cps/cm2) after 6-12 h of sepsis, while liver chemiluminescence increased by about 80% (control emission: 11 +/- 1 cps/cm2) after 24 h of sepsis. The activities of muscle antioxidant enzymes were found maximally diminished after 12 h of sepsis: 46% decrease for Mn-superoxide dismutase, 83% decrease for catalase, and 55% decrease for glutathione peroxidase. In liver, only catalase activity showed a 52% decrease after 24 h of sepsis. State 3 oxygen uptake of muscle mitochondria with either malate-glutamate or succinate as substrates was 40% decreased after 12 h of sepsis in both cases. State 4 oxygen uptake of muscle mitochondria was not affected. The rate of H2O2 production of muscle mitochondria after 12 h of sepsis with either malate-glutamate or succinate as substrates was increased about 2.5 times but was not affected when assayed in the presence of as rotenone and antimycin. The oxygen uptake of liver mitochondria isolated from septic rats did not show differences as compared with those of control rats after 6 to 24 h of sepsis. Oxidative stress appears to occur in skeletal muscle early at the onset of the septic syndrome, with inhibition of active mitochondrial respiration and inactivation of antioxidant enzymes.(ABSTRACT TRUNCATED AT 250 WORDS)

Analysis of Variance↗
PubMed1994

Liver oxygen uptake dependence and mitochondrial function in septic rats.

Defective oxygen consumption and a pathological dependence of oxygen uptake on O2 supply have been considered important events in sepsis. To relate these features with tissue and mitochondrial metabolism, we studied oxygen uptake in whole isolated and perfused rat liver at two O2 supply levels, in the same liver slices, and in isolated liver mitochondria. Experimental sepsis in rats was induced by cecal ligation and double-gauge puncture. The results showed that liver and tissue slices from septic animals had a 60% greater O2 uptake than that of controls and that, during sepsis, liver O2 uptake was markedly dependent on O2 supply. Concomitantly, mitochondrial O2 uptake was nearly 30% greater with malate-glutamate as substrate, but not with succinate; lowering O2 concentration in the medium did not alter the enhanced function. In submitochondrial, only NADH-dehydrogenase activity was 100% higher in septic samples. At least, in some tissues, O2 dependence is a function of O2 availability, sensitized by increased mitochondrial O2 uptake related to changes in respiratory enzymes.

Adenosine Diphosphate↗
PubMed1994

[Hypothermia: a non renal indication for peritoneal dialysis].

Accidental hypothermia, a condition seldomly seen in Chile, is defined as a spontaneous core temperature reduction to less than 35 degrees C and is associated with great morbidity and mortality. We report a 16 years old female intoxicated with liquefied petroleum gas that was admitted in coma, hypothermic, with severe hemodynamic derangement, lactic acidosis, rhabdomyolysis and iliofemoral phlebothrombosis. Peritoneal dialysis with solutions at 27 degrees C was used as a quick and safe means to revert hypothermia and avoid its complications.

Adolescent↗
PubMed1987

Ambroxol plus amoxicillin in the treatment of exacerbations of chronic bronchitis.

Twenty-three patients with exacerbations of chronic bronchitis were divided in two groups in a randomized fashion receiving either amoxicillin 1500 mg/d (n = 13) or amoxicillin 1500 mg/d associated with the mucolytic drug ambroxol 90 mg/d (n = 10). The improvement in cough, expectoration difficulties and sputum purulence was statistically more evident and occurred earlier in the ambroxol + amoxicillin group than in the amoxicillin only group. Although amoxicillin plasma and sputum levels were similar in both groups, the differences in daily sputum volume, which was also statistically greater in patients receiving ambroxol, suggests that this drug favours the bronchial mucus clearance of the antibiotic which could be related to the more favourable clinical evolution. No changes were observed in lung function tests and blood gases.

Adult↗
PubMed1979

Multifocal adenocarcinoma of the jejunum.

We report on an 89-year-old female admitted with signs of intestinal obstruction in whom three independent adenocarcinomas of the proximal jejunum were found. Multiple foci of pyloric gland metaplasia, glandular hyperplasia and dysplasia, carcinoma-in-situ, and several varieties of adenocarcinoma were identified on microscopic examination of 14 cm of excised jejunum. Multifocal adenocarcinoma of the small intestine is extremely rare. We are not aware of any case harboring the complex changes described herein.

Adenocarcinoma↗
PubMed1977

Dilatation and curettage for second-trimester abortions.

This study reports the outcome of 2,500 consecutive second-trimester abortions performed with the dilatation and curettage methods. Of the abortions, 99.2 per cent were for gestations between the fifteenth and eighteenth menstrual weeks of pregnancy. We determined that this procedure is both safer and less traumatic than intrauterine saline or prostaglandin instillation. The low incidence of uterine perforation (0.08 per cent) and over-all morbidity (2.8 per cent) and the short duration of hospitalization (average 1.1 days per patient per procedure), as well aa the absence of any death in our series, substantiate this premise.

Abortion, Induced↗