Effect of hyperbaric oxygenation on random rat skin flaps vascularization

ABSTRACT Purpose: To evaluate the effect of hyperbaric oxygenation (HBO) on angiogenesis in random rat skin flaps, by immunoexpression of vascular endothelial growth factor A (VEGF-A). Methods: Forty adult rats were divided into four groups: GE) epilated; GE/HBO) epilated subjected to HBO; GER) epilated submitted to dorsal skin flap; GER/HBO) epilated subjected to dorsal skin flap + HBO. HBO was performed with rats inside a chamber under atmosphere close to 100% oxygen and pressure of 2.4 absolute atmospheres, 2h per day during seven consecutive days. GE and GER groups were placed in the hyperbaric chamber without HBO. Then, under anesthesia, skin flaps were removed and separated into three portions relative to pedicle fixation. The samples were fixed in formalin and processed for paraffin embedding. Histological sections were submitted to immunohistochemistry for VEGF-A detection. The number of immunostained-blood vessels were counted under light microscopy. Results: GE and GE/HBO groups showed normal and similar skin morphology in the three flap portions. A fibrin-leukocyte crust, along with denatured collagen and intense leukocyte infiltrate, was mainly observed in the dermis of the medial and distal flap portions of GER group. Meanwhile, the GER/HBO group presented more regions with intact collagen and small areas of leukocyte infiltrate in the three flap regions. VEGF-A-immunostained blood vessels were largely seen in all regions of GE and GE/HBO groups, whereas no significant differences were found between these groups. A decrease in vascularization was noticed in GER and GER/HBO groups, which was more evident in the most distal portion of the flaps. However, the number of VEGF-A-immunostained blood vessels in GER/HBO group was significantly higher when compared to GER group. Conclusions: Hyperbaric oxygenation was associated with increased angiogenesis and improved viability of rat skin flaps.

Action of hyperbaric oxygenation in the rat skin flap

PURPOSE: To evaluate the morphology, necrotic area and collagen content in skin flaps of rats subjected to hyperbaric oxygenation (HBO). METHODS: Forty adult rats were divided into four groups: GEC - epilated; GE/HBO - epilated subjected to HBO; GER - epilated submitted to skin flap (2 cm in width /8 cm length in the dorsal area) and GER/HBO - epilated, subjected to skin flap and HBO. HBO (2.4 ATA) was performed for two hours during seven consecutive days. In the eighth day, the rats were anesthetized and the skin flaps were removed and separated into three portions, relative to pedicle fixation. The material fixed in 10% formalin was processed for paraffin embedding; sections were stained by H.E and subjected to picrosirius-red method. The slides examined under light microscopy for evaluation of the collagen content in polarized light microscope and ImageLab(r) software (Bio-Rad). RESULTS: The data showed larger area of necrosis and lower levels of collagen in the three regions of the GER group, whereas in the GER/HBO group the collagen content was similar to the GEC and GE/HBO groups. CONCLUSION: Hyperbaric oxygenation reduced the area of necrosis and preserved the morphology and collagen content in skin flaps of rats. .

Síndrome inapropriada do hormônio antidiurético (SIADH) pós-abdominoplastia / Syndrome of inappropriate secretion of antidiuretic hormone (SIADH) post abdominoplasty

Este é um caso de síndrome inapropriada do hormônio antidiurético (SIADH) em umamulher, 39 anos, hígida, sem comorbidades importantes, submetida a abdominoplastia semlipoaspiração associada, que desenvolveu, 30 horas após a cirurgia, hiponatremia aguda(sódio 114,9 mEq/L-1), com importantes manifestações neurológicas. O difícil diagnósticoprecoce desta situação clínica grave, em pacientes saudáveis, pode causar importantes sequelasneurológicas e até mesmo o óbito. O diagnóstico precoce e a instituição de tratamentode reposição corretos são a chave para evitar lesões cerebrais irreversíveis.

This is a case of syndrome of inappropriate anti-diuretic hormone (SIADH) in a healthy woman,39 years old without comorbites, with developed postoperative acute hyponatremia (sodium 114mEq/L-1) after abdominoplasty without liposuction with important neurologic manifestations.The initial diagnosis of this syndrome in normal patients could avoid permanent neurologicdamage. The early recognition and correct treatment are vital to avoid a poor cerebral outcome.

A proposal of multiplace hyperbaric chamber for animal experimentation and veterinary use / Uma proposta de câmara hiperbárica para uso em animal de experimentação e uso veterinário

PURPOSE: To develop a project of hyperbaric chamber that allows its safe and reliable use in veterinary and animal experimentation. METHODS: Based on the technical specifications for the construction of hyperbaric chambers for human beings, it has been developed a design of a chamber with dimensions and characteristics for the use of a midsize animal, (dog or pig), as well as a multiple chamber for the use in small animals (mice, rats, hamsters, rabbits or cats). The technical specifications allowed that the chamber could be used both for veterinary use and for use in experiments on Health Sciences. RESULTS: A chamber with the following characteristics was built: ASTM A36 steel for the manufacture of the master cylinder and rear cover; front door built in 5052 aluminum; internal diameter of 50.5 cm and 83.0 cm in length; weight 160Kg and internal area of 150cm³; internal space to accommodate 2 acrylic baskets; 150mm high, 280mm wide and 690mm in length. It was capable of supporting a maximum of hydrostatic pressure test of 3.0 to 4.0 BAR ACT and maximum working pressure of 2.0 BAR or 3.0 ACT; equipped with security devices and valves that triggers with load of 2.2 BAR or 3.2 ACT. Tests for engineering and biological use on animals showed the effectiveness of the device. CONCLUSION: The development of the project enabled the construction of a hyperbaric chamber with security features and reliability comparable to those required by the legal and technical specifications of a hyperbaric chamber human use.

OBJETIVO: Desenvolver um projeto de câmara hiperbárica que permita o seu uso seguro e confiável em veterinária e em animais de experimentação de pequeno e médio porte. MÉTODOS: Baseados em especificações técnicas de construção de câmaras hiperbáricas de seres humanos, foi desenvolvido uma adaptação de projeto de uma câmara com dimensões e características para uso em animal de médio porte (cão ou porco), assim como câmara múltipla para animais de pequeno porte (camundongos, ratos, hamsters, coelhos ou gatos). O atendimento às especificações técnicas deve permitir a sua utilização tanto para uso veterinário quanto para uso em experimentação em Ciências da Saúde. RESULTADOS: Uma câmara com as seguintes características foi construída: aço ASTM A36 para a confecção do cilindro principal e tampo traseiro, tampo frontal (porta) construído em alumínio 5052, diâmetro interno de 50,5cm e 83,0cm de comprimento; peso de 160Kg e espaço interno de 150cm³; espaço para acomodar 2 cestas de acrílico de 150mm de altura, 280mm de largura e 690mm de comprimento; capacidade para suportar um máximo de pressão hidrostática teste de 3,0BAR ou 4,0 ACT e uma pressão máxima de trabalho de 2,0 BAR ou 3,0 ACT; equipado com dispositivos e válvulas de segurança que disparam com carga de 2,2 BAR ou 3,2 ACT. Os testes de engenharia e de uso biológico com animais mostraram a efetividade do equipamento. CONCLUSÃO: O desenvolvimento do projeto permitiu a confecção de uma câmara hiperbárica com características de segurança e confiabilidade comparável às exigidas pelas especificações técnicas e legais de uma câmara para tratamento hiperbárico.

Revisäo da técnica das suturas mecânicas do aparelho digestivo / Review of mechanic suture in gastrointestinal system

Os autores fazem um estudo a respeito das técnicas de sutura mecânica no aparelho digestivo desde o seu surgimento até os dias atuais. Apresentam aspectos históricos da sutura mecânica bem como os tipos de aparelhos utilizados para as suturas de aparelho digestivo. São feitos comentários das desvantagens, bem como de suas complicações