Effect of irradiation with different laser wavelengths on oxidative stress of non-hepatectomized rats

PURPOSE: To assess the effect of two laser wavelengths, either separate or combined, on intact rat livers. METHOD: Nineteen male Wistar rats (200-300 g) were submitted to laser irradiation at 5 different sites on the liver surface.Wavelengths 660 and 780 nm were used, with a dose of irradiation of 60 J/cm2/site.The animals were divided into the groups:control (C) and animals irradiated with 660 nm laser (L1), with 780 nm laser (L2) or withboth wavelengths (L3).Mitochondrial function, mitochondrial swelling, and hepatocellular malondialdehyde (MDA) levels were determined.Data were analyzed by the Mann-Whitney test, with the level of significance set at 5%. RESULTS: There was a reduction of ADP-activated respiration (state 3) in group L1 compared to group C (p=0.0016), whereas the values of group L2 were similar to control.Group L3 also showed a reduction of state 3 (p=0.0159).There was a reduction of RCR in group L1 compared to control (p=0.0001) and to group L2 (p=0.0040).Mitochondrial swelling only differed between group L3 and control (p=0.0286).There was a increase in MDA levels in group L3 compared to control (p=0.0476) and to group L2 (p=0.0286) and in group L1 compared to group L2 (p=0.0132). CONCLUSION: Although laser irradiation reduced mitochondrial function,it did not interfere with the hepatocellular energy status.

Hyperbaric oxygen therapy and ischemia and reperfusion: a valuable association to attenuate ischemic lesion and hepatic reperfusion

PURPOSE: To investigate the consequences of the association between hyperbaric oxygen therapy and hepatic ischemia / reperfusion. METHODS: Wistar rats were divided into three groups: SHAM, rats submitted to surgical stress and anesthetic but not hepatic ischemia or reperfusion, I / R, rats submitted to total hepatic pedicle ischemia for 30 min, followed by 5 min of reperfusion; HBO120, rats submitted to 120 min of hyperbaric oxygen therapy at two absolute atmospheres and immediately after submitted to the experimental protocol of ischemia and reperfusion. The preservation of the hepatic function was evaluated by determining mitochondrial swelling and malondialdehyde tissue level, as well as alanine aminotransferase and aspartate aminotranferase serum levels. The results were analyzed using the Mann-Whitney test and differences were considered significant for p<0.05. RESULTS: There were significant differences in values: mitochondrial swelling of the I / R group compared to SHAM and HBO120; malondialdehyde between SHAM vs. I / R, SHAM vs HBO120, and I / R vs HBO120, alanine aminotransferase between SHAM vs. I / R . There was no significant difference between groups in aspartate aminotransferase serum levels. CONCLUSION: The association between hyperbaric oxygen therapy and hepatic ischemia and reperfusion process was positive.

Morphologic evaluation of the use of a latex prosthesis in videolaparoscopic inguinoplasty: an experimental study in dogs / Avaliação morfológica da utilização de prótese de latex na inguinoplastia videolaparoscópica: estudo experimental em cães

PURPOSE: To evaluate the morphological aspects of the behavior of 4 types of latex biomembranes implanted in preperitoneal videolaparoscopic inguinoplasty. METHODS: Sixteen inguinoplasties were performed in 12 dogs: group 1 received an impermeable latex biomembrane in the right inguinal region and a prolene prosthesis, as control, in the contralateral inguinal region; groups 2, 3 and 4 received latex biomembranes respectively containing impermeable polyamide, 1-mm thick porous polyamide and 0.5-mm thick porous polyamide. Macro- and microscopic evaluations of the inguinal region and of the removed implants were made on the 7th, 14th, 21st and 28th days in group 1 and on the 28th postoperative day in the other groups. RESULTS: We observed absence of hematoma, seroma and infection; presence of tortuosities; induction of vascular neoformation, inflammatory reaction and collagen deposition, and full encystment of the latex biomembranes, except that with fine porous polyamide, which was partially incorporated, with the formation of microcysts. No latex biomembrane induced fibrosis as observed in the prolene control group. CONCLUSIONS: The biomembranes maintain induction of the healing process without fibrosis, are fully encysted and, except for the one with fine porous polyamide, are not incorporated into adjacent tissues. The latex biomembrane, with or without polyamide, is not recommended as a separate material for preperitoneal inguinoplasty.

OBJETIVO: Avaliar aspectos morfológicos do comportamento de 4 tipos de biomembranas de latex, colocadas pré-peritonealmente em cães, por inguinoplastia videolaparoscópica. MÉTODOS: Dezesseis inguinoplastias em 12 cães: grupo 1, com biomembrana de latex impermeável inguinal direita em quatro cães e prótese de prolene, como controle, contra-lateral; grupos 2, 3 e 4, com biomembrana de latex respectivamente de poliamida impermeável, poliamida porosa com 1mm de espessura e poliamida porosa com 0,5mm de espessura. Avaliou-se a região inguinal e as peças retiradas macro e microscopicamente, no grupo 1 no 7º, 14º, 21º e 28º dias e nos demais grupos no 28º dia pós-operatório. RESULTADOS: ausência de hematoma, seroma e infecção; presença de tortuosidade; indução de neoformação vascular, reação inflamatória, deposição de colágeno e encistamento total das biomembranas de latex, exceto com poliamida porosa fina que se incorporou apenas parcialmente, com formação de microcistos. Nenhuma biomembrana de latex induziu fibrose como no grupo controle prolene. CONCLUSÕES: As biomembranas mantêm indução do processo de cicatrização sem fibrose, sofrem encistamento e, exceto com poliamida porosa fina, não se incorporam aos tecidos vizinhos. A biomembrana de latex, com e sem poliamida, isoladamente não é recomendada para inguinoplastia pré-peritoneal.

Liver transplantation as a multidisciplinary strategy for undergraduate education / Transplante de fígado como estratégia multidisciplinar de ensino de graduação

The program of liver transplantation can contribute in an excellent manner to undergraduate educationon a daily basis, especially in the form of scientific initiation with studies of experimental investigation in the laboratory or as formal monitoring in experimental or clinical investigation. In the latter modality, the student helps his tutoring professor in activities more related to the ward and to the Surgical Center, with studies on the clinical follow-up of patients, or with case studies in both prospective and retrospective investigations. It is the task of the adviser to attribute balanced activities whose time of execution will not interfere with formal graduation hours. Similarly, it is the responsibility of the student to structure his free time in order to devote part of it to the exercise of scientific activity. On this basis, the medical student will have the opportunity to experience the most varied facets of transplantation, acquiring the necessary systemic view of the procedure as his knowledge expands. The importance of liver transplant is exactly this, i.e., to obtain a complete idea of the whole with daily contact along time starting from the complex parts that constitute the procedure, exposes the student to diverse clinical situations rarely encountered together in other specialties, permitting him to participate in situations and discussions that are not often addressed during the medical course.

O programa de transplante de fígado presta-se, no dia a dia, de forma excelente, ao ensino de graduação, especialmente na forma de iniciação científica com trabalhos de investigação experimental em laboratórios ou na forma de monitoria formal em investigação experimental ou clínica. Nesta segunda modalidade, o aluno auxilia o professor orientador em atividades mais ligadas à enfermaria e centro cirúrgico, com trabalhos de acompanhamento clínico dos doentes, ou estudos de casos em investigações tanto prospectivas como retrospectivas. Cabe ao orientador, atribuir atividades balanceadas, cujos horários de execução não colidam com os formais da graduação. Da mesma forma, cabe ao aluno estruturar suas horas livres para dedicar parte delas ao exercício da atividade científica. Assim, o aluno de graduação, terá a oportunidade de vivenciar as mais variadas facetas do transplante, tendo dele a necessária visão sistêmica, à medida que seu conhecimento se amplia. A importância do transplante é exatamente esta, com o contato diário, ao longo do tempo, formar a ideia plena do todo a partir das complexas partes que o constituem, propiciando ao graduando participar de situações e discussões que não são frequentemente abordadas durante a graduação.