João Baptista Rezende Neto

Hyperbaric oxygen therapy aggravates liver reperfusion injury in rats

PURPOSE To evaluate the effects of hyperbaric oxygen (HO) therapy in the protection against liver ischemia/reperfusion injury. METHODS Thirty-two male Wistar rats were divided into four groups of eight animals each: group A - laparotomy and liver manipulation, group B - liver ischemia and reperfusion, group C - HO pretreatment for 60 min followed by liver ischemia and reperfusion, and group D - pretreatment with ambient air at 2.5 absolute atmospheres for 60 min followed by liver ischemia and reperfusion. Plasma was assayed for aspartate aminotransferase (AST), alanine aminotransferase (ALT) and lactate dehydrogenase (LDH). Intra-arterial blood pressure was monitored continuously. Myeloperoxidase activity in the liver and lung was assessed 30 min after reperfusion. RESULTS Plasma AST, ALT and LDH increased after reperfusion in all animals. Plasma ALT values and myeloperoxidase activity in the liver parenchyma were higher in HO-pretreated animals than in groups A, B and D. HO had a negative hemodynamic effect during liver reperfusion. CONCLUSION Liver preconditioning with hyperbaric oxygen therapy aggravated liver ischemia/reperfusion injury in rats as demonstrated by plasma ALT and liver myeloperoxidase activity.

Abordagem do trauma renal - artigo de revisão: review of the literature

Trauma incidence is increasing nowadays. Kidney injuries occur in about 10% of patients with blunt or penetrating trauma, and those lesions add morbidity and mortality when not appropriate care is carried out. A literature review of the most recent papers was done by the authors to clarify diagnosis and final treatment. The correct management is a must to preserve and keep the kidney function, moreover, the quality of life after a trauma event.

Tratamento de hemorragia intestinal grave decorrente de hipertensão porta, por meio de esplenectomia subtotal e anastomose esplenorrenal proximal

OBJETIVO: Um dos maiores desafios no tratamento da hipertensao porta e o sangramento de varizes intestinais. O objetivo deste artigo e apresentar um novo tratamento para hemorragia enterica grave provocada por hipertensao porta cirrotica, utilizando a esplenectomia subtotal combinada com derivacao esplenorrenal proximal. TECNICA: Uma paciente de 64 anos apresentou sangramento intenso proveniente de varizes em alca jejunal em Y de Roux, para derivacao biliodigestiva, apos lesao coledociana, complicada com cirrose hepatica. O procedimento consistiu em esplenectomia subtotal, preservando o polo superior do baco, suprido apenas pelos vasos esplenogastricos, e anastomose termino-lateral da veia esplenica, em sua extremidade proximal, a veia renal esquerda. RESULTADOS: Esse procedimento foi seguro, sem sangramento maior, dificuldade tecnica ou complicacao. No acompanhamento de 30 meses, a paciente nao teve novos episodios de sangramento, a cirrose nao avancou e, atualmente, encontra-se bem, sob controle. CONCLUSAO: A esplenectomia subtotal combinada com derivacao esplenorrenal proximal e uma boa alternativa operatoria para tratar hemorragia proveniente de varizes intestinais, decorrentes de hipertensao porta.

Regional Blood Flow after Intravenous Administration of Scorpion Venom in Rats

The accidents by scorpion stings in Brazil, particularly in Belo Horizonte, capital of Minas Gerais state are caused by Tityus serrulatus species and accounts for fatal stings, especially in children and elderly people. The death in severe evenomation is caused by a circulatory shock, associated with respiratory and cardiovascular arrhythmias, cardiogenic shock, pulmonary edema, respiratory depression, acid-base disorders and serious coagulation disturbance. Our group has been involved in the study of several aspects of the mechanism of action of scorpion toxins injected in animals. However some aspects of the envenomation, such as, the regional blood flow distribution to several organs need further studies. The aim of the present work was to determine the flow to different organs after intravenous injection of the gamma fraction of toxins isolated from the T. serrulatus scorpion venom adding more information that would contribute to a better understanding of the pathophysiology of scorpion sting envenomation. The fluorescent microspheres deposition technique was used to evaluate the regional blood flow and regional vascular resistance of several organs in anesthetized rats after Tityus serrulatus scorpion venom (Tx) injection. Fluorescent microspheres of different colors were injected into the left ventricle through the carotid artery. Reference blood samples were collected from the left femoral artery at baseline (before) and 5, 15 and 30 min after toxin injection. Tissue samples from the adrenal gland, spleen, brain, heart, liver, ileum, mesentery, muscle, skin, lung and kidney were harvested and prepared for fluorescent measurements using a spectrophotometer. Hemodynamic parameters were monitored continuously. Blood flow variation was detected in the tissue samples and were different among the organs. The most common finding was a decrease in flow, varying with time and the severity of the intoxication. However, intrinsic mechanisms of auto-regulation of blood flow and vascular resistance possibly protect the heart and the brain from hypoperfusion after Tx injection.