Epitelização de enxertos cutâneos em feridas recentes de coelhos tratados com membrana amniótica canina e/ou laserterapia / Skin graft epithelialization in rabbit fresh wounds treated with amniotic membrane and/or laser therapy

A enxertia cutânea é uma técnica cirúrgica simples e bastante útil para o reparo de feridas, principalmente aquelas onde existe dificuldade da aplicação do fechamento primário ou de outras técnicas reconstrutivas. Entretanto, para a sobrevivência do enxerto, é necessário que o leito da ferida esteja saudável e com presença de tecido de granulação exuberante. O objetivo do presente trabalho foi avaliar a aplicação da membrana amniótica e da laserterapia como potenciais estimulantes da cicatrização em enxertos aplicados em feridas sem tecido de granulação. Foram utilizados 42 coelhos, divididos em quatro grupos: grupo controle (GC), grupo membrana (GM), grupo laser (GL) e grupo membrana e laser (GML), submetidos a avaliações macro e microscópicas. Na avaliação macroscópica, foi possível notar que os pacientes dos grupos nos quais a membrana amniótica foi utilizada (GM e GML) apresentaram evidências associadas à acentuada reação inflamatória, à falha de integração do enxerto e à consequente necrose dele. Já os pacientes do GL apresentaram melhor aspecto do enxerto no último dia de avaliação. Na análise microscópica, observou-se intensa integração do enxerto à derme, reepitelização acentuada e escassas células inflamatórias no local do enxerto no GL. O contrário foi observado nos pacientes do GM e GML, nos quais aparentemente houve rejeição da membrana. A formação de colágeno não se correlacionou com outros fatores, como inflamação e necrose, em nenhum dos grupos de tratamento. Dessa forma, é possível afirmar que a laserterapia mostrou ser efetiva, contribuindo para o processo cicatricial e a integração do enxerto. Já a membrana amniótica canina não deve ser utilizada para esse fim, pois provoca intensa reação inflamatória, além de impedir a nutrição do enxerto.(AU)

Skin grafting is a simple surgical technique and useful to repair wounds, especially those where there is a difficulty to apply primary closure skin or other reconstructive techniques. However, for graft survival a healthy wound bed and the presence of an exuberant granulation tissue are necessary. This study aimed to evaluate the application of amniotic membrane and laser therapy as potential healing stimulants in grafts applied in wounds without granulation tissue. For this, we used 42 rabbits divided into four treatment groups, control group (CG), membrane group (MG), laser group (LG) and membrane and laser group (MLG), submitted to macroscopic and microscopic evaluation. The macroscopic examination showed that the patients of the groups where the amniotic membrane was used in order to stimulate re-epithelialization (MG and MLG) presented evidences associated with severe inflammatory reaction, graft integration failure and consequent necrosis. LG patients apparently had the best graph aspect in the last valuation date. Microscopic examination showed intense integration of the graft to the dermis, high re-epithelialization level, and scarce inflammatory cells in the graft site of LG patients. The opposite was observed in patients in the MG and MLG groups, where a rejection of the membrane was observed. Finally, collagen formation was not correlated with other factors such as inflammation and necrosis in any of the treatment groups. We can conclude that laser therapy was effective, contributing to the healing process and integration of the graft. Thus, canine amniotic membrane should not be used for this purpose because it causes intense inflammatory reaction besides avoiding graft nutrition.(AU)

Lysosome response and cytoskeleton alteration in cell cultures exposed to airborne lead.

The results indicate that the delay in acridine orange loss by lysosomes exposed to UV can serve as a sensitive probe to the lead content of the cell milieu and the induced responses. This lysosome stabilization is in agreement with the reported decreased release of lysosome enzymes by lead in rat cerebral tissue. The lead induced lysosome stabilization reported here is undoubtedly pathologic in view of the cytoskeleton alteration that usually accompanied the introduction of lead in the cell media either from laboratory sources or natural conditions.

[Studies on the effects of atrazine and simazine on the N-binding bacteria Azotobacter and Beijerinckia in the ferralitic soils of Cuba]. / Untersuchungen über den Einfluss von Atrazin und Simazin auf die N-bin-denden Bakterien Azotobacter und Beijerinckia in ferrallitischen Böden Kubas.

In two Cuban locations (Santiago de las Vegas and Jovellanos) the effect was investigated of increasing atrazin and simazin applications (0, 4, 8, 16 kg/ha) to the number of Azotobacter and Beijerinckia colonies in weakly ferrallitic soils 7 and 15 days after their application during the rainy and dry seasons. The results were as follows: 1. The number of the Beijerinckia colonies is higher in all variants than that of Azotobacter. 2. Beijerinckia and Azotobacter are stimulated up to 7 days, partly also up to 15 days, after application of the triazins. Atrazin exhibits a stronger and more lasting effect than simazin, and Azotobacter are influenced more strongly than Beijerinckia. 3. This stimulation can be adduced with a high degree of probability to the inhibition of organisms which have an antagonistic effect on N-binding bacteria.

[Methodical studies on determination of the number of micro-organisms in Cuban soils]. / Methodische Untersuchungen zur Bestimmung der Anzahl von Mikroorganismen in Böden Kubas.

In four Cuban soils (ferrallitic soil, non-calcareous and calcareous brown tropical soil, and fersiallitic sandy soil) the suitability was tested of 7 dispersion solutions and of 4 culture media for determining the total number of bacteria, fungi and actinomycetes. The results were as follows: (1) The dispersion solution and the culture medium most suitable for the most comprehensive determination of the number of microbes is dependent on the physical and chemical soil properties. (2) The optimum combination of dispersion solution and culture medium was found for the various soils as follows: -Na-pyrophosphate in the soil extract and concentrated agar bouillon, respectively, for ferrallitic soils, -Na-K-tartrate solution and concentrated soil extract, respectively, for non-calcareous brown tropical soils, -Na-pyrophosphate solution in water and concentrated bouillon or soil extract, respectively, for calcareous brown tropical soils, -soil extract as a dispersion solution and as culture medium in fersiallitic sandy soils.