Enhancement of cellular activity in hyperglycemic mice dermal wounds dressed with chitosan-alginate membranes

The use of specially designed wound dressings could be an important alternative to facilitate the healing process of wounds in the hyperglycemic state. Biocompatible dressings combining chitosan and alginate can speed up wound healing by modulating the inflammatory phase, stimulating fibroblast proliferation, and aiding in remodeling phases. However, this biomaterial has not yet been explored in chronic and acute lesions of diabetic patients. The aim of this study was to evaluate the effect of topical treatment with a chitosan-alginate membrane on acute skin wounds of hyperglycemic mice. Diabetes mellitus was induced by streptozotocin (60 mg · kg-1 · day-1 for 5 days, intraperitoneally) and the cutaneous wound was performed by removing the epidermis using a surgical punch. The results showed that after 10 days of treatment the chitosan and alginate membrane (CAM) group exhibited better organization of collagen fibers. High concentrations of interleukin (IL)-1α, IL-1β, granulocyte colony-stimulating factor (G-CSF), and tumor necrosis factor-alpha (TNF-α) were detected in the first and second days of treatment. G-CSF and TNF-α level decreased after 5 days, as well as the concentrations of TNF-α and IL-10 compared with the control group (CG). In this study, the inflammatory phase of cutaneous lesions of hyperglycemic mice was modulated by the use of CAM, mostly regarding the cytokines IL-1α, IL-1β, TNF-α, G-CSF, and IL-10, resulting in better collagen III deposition. However, further studies are needed to better understand the healing stages associated with CAM use.

Polypropylene meshes coated with chitosan/polyethylene glycol for the reconstruction of the abdominal wall: an experimental study in rats / Telas de polipropileno revestidas com o filme de quitosana/polietilenoglicol para a reconstrução da parede abdominal: estudo experimental em ratos

The aim of this study was to characterize the tissue reactions triggered by the polypropylene mesh coated with chitosan and polyethylene glycol film, and if it's able to prevent the formation of peritoneal adhesions. Defects in the abdominal wall of rats were induced and polypropylene meshes coated with chitosan/polyethylene glycol (CPEG group, n= 12) and uncoated (PP control group, n= 12) were implanted. On the fourth and forty-fifth postoperative day the formation of adhesion and the tissue reaction to the biomaterial was evaluated through histological and histochemical analysis. The area (P= 0.01) and severity (P= 0.002) of the adhesion was significatively less in the CPEG group. On the fourth day the foreign body reaction was less intense in CPEG group (P= 0.018) and the production of collagen fibers was more intense in this group (P= 0.041). The tissue reactions caused by the biomaterials were similar on the 45th day, with the exception of the high organization of collagen fibers in the CPEG group. The CPEG meshes did not fully prevent the formation of adhesions, but minimized the severity of the process. The foreign body reaction promoted by polypropylene meshes coated with CPEG is less intense than that triggered by uncoated polypropylene meshes.(AU)

O objetivo deste estudo foi caracterizar as reações tissulares desencadeadas pela tela de polipropileno revestida com o filme de quitosana e polietilenoglicol e verificar se ela é capaz de prevenir a formação de aderências peritoneais. Um defeito na parede abdominal dos ratos foi realizado, e as telas de polipropileno revestidas com quitosana/polietilenoglicol (grupo CPEG, n= 12) e sem revestimento (grupo controle PP, n= 12) foram implantadas. No quarto e no 45º dia pós-operatório, avaliou-se a formação de aderências e a reação tecidual ao biomaterial por análise histológica e histoquímica. A área (P= 0,01) e a severidade (P= 0,002) da aderência peritoneal foram significativamente menores no grupo CPEG no 45º dia. No quarto dia, observou-se que a reação do corpo estranho foi menor no grupo CPEG (P= 0,018), e a produção de fibras de colágeno mais intensa (P= 0,041). As reações tissulares causadas pelos biomateriais implantados foram semelhantes no 45º dia, com exceção da melhor organização das fibras colágenas no grupo CPEG. As telas CPEG não impediram completamente a formação de aderências, porém minimizaram a gravidade do processo. A reação de corpo estranho promovida por telas de polipropileno revestidas com CPEG é menos intensa do que a desencadeada por telas de polipropileno não revestidas.(AU)

Baccilary angiomatosis: negative results using normal Balb/c and Balb/c nude mice

Baccilary angiomatosis has recently been described as a disease that can spread systematically and that is potentially fatal. It is caused by Bartonella henselae and B. quintana, and presents as especially pronounced signs and symptoms in patients suffering from acquired immunodeficiency syndrome (AIDS). To clarify the pathogenesis of the disease and to try to define the relationships among baccilary angiomatosis, cat scratch disease and Carrión's bartonellosis, the authors of this study have attempted to develop an experimental model using mice that were immunocompetent as well as those that had their cellular immunity genetically compromised. A know concentration of B. henselae was inoculated intradermally in Balb/c an isogenic mice or an athymic group of the same lineage. Blood samples were taken on days-0, 3, 7, 10, 14, 28, and 60 after inoculation for indirect immunofluorescence antibody testing. On the 21st and 60th day, one animal from each group was sacrificed and a post mortem carried out including histological evaluation of the liver, spleen, lymph nodes, skin and other organs. Hemocultures of the sacrificed animals were collected. All results of serologic response, cultures and histologic examination were negative. The authors discuss the methodology, especially the use of isogenic animals of the same lineage in B. henselae infection, with and without immunodeficiency, and the resources for the negative results of histopathology, serology and cultures.

Insulin resistance in psoriasis

The oral glucose tolerance test (OGTT) and intravenous insulin tolerance test (15-min ITT) were applied to ten patients with psoriasis and to 11 control subjects. No significant differences in mean plasma glucose levels were detected between psoriatic patients and normal individuals. In contrasts, serum insulin levels were significantly higher for the psoriatic patients as compared to the controls at 30, 60 and 120 min during the OGTT (P<0.05). The glucose disappearance rate during the 15-min ITT was lower in patients with psoriasis than in controls (5.1 + or - 0.5 percent min vs 7.5 + or - 0.4 percent/min, P<0.05), demonstrating a state of insulin resistance. Interestingly, the reduction in serum potassium levels during the ITT was also lower in the patients than in the controls (0.6 + or - 0.06 mEq/l vs 1.06 + or - 0.07 mEq/l,P<0.05), suggesting that the insulin resistance observed in psoriasis is not only related to glucose metabolism, but also to another important action of insulin, namely extrarenal potassium homeostasis

Piodermite vegetante: estudo clínico e terapêutico / Pyodermitis vegetans: clinical and therapeutic study

Os autores apresentam um caso de piodermite vegetante, ou piodermite semelhante à blastomicose, dermatose rara e de difícil diagnóstico clínico e laboratorial em nosso meio.Manifesta-se com morfologia exuberante e comum a várias dermatoses infecciosas. Trata-se de provável resposta tecidual proliferativa e alteraçäo imunológica individuais à presença dos agentes infecciosos encontados. A resposta terapêutica à corticoterapia foi relevante, pórem introduzida somente após exaustiva procura dos prováveis diagnósticos diferenciais

Estrongiloidíase: caso fatal por peritonite secundária à perfuraçäo intestinal / Strongyloidiasis: fatal case due to peritonitis secondary to intestinal perforation

Descreve-se um caso de estrongiloidíase complicado por peritonite secundária a perfuraçäo intestinal, com evoluçäo fatal, na vigência de terapêutica imunossupressora (corticoterapia)