Alloxan diabetes alters the tensile strength, morphological and morphometric parameters of abdominal wall healing in rats

To investigate the effects of alloxan diabetes on the abdominal wall healing of rats undergoing laparotomy. METHODS: Ninety-six male Wistar rats weighing between 200 and 300 grams, divided into two groups: non-diabetic group (G1) and another with untreated diabetes (G2). Three months after diabetes induction, the animals underwent a 5cm-long- laparotomy and 5.0 nylon monofilament suture. After the surgery, 12 animals from each group were euthanized on days 4, 14, 21 and 30 corresponding to the moments M1, M2, M3 and M4. In each moment a fragment of the abdominal wall containing the scar was removed for tensile strength measurement, histological and morphometric study. Clinical and biochemical parameters were also analyzed. RESULTS: G2 animals showed parameters compatible with severe diabetes and decreased plasma levels of insulin. The tensile strength in G2 was significantly smaller in M2 and M4, with a tendency to fall in the other two. Through light microscope, diabetic animals showed more difficulty to increase collagen density and contraction. G2 animals showed high cellularity of fibroblasts in later healing moments, with collagen thinning in M2 and M4. CONCLUSION: The abdominal wound healing in untreated diabetic animals was altered and led to a higher incidence of dehiscence and infections.(AU)

Nephrocalcinosis induced by hyperoxaluria in rats

PURPOSE: To investigate nephrocalcinosis due to hyperoxaluria induced by two different inducing agents in rats. METHODS: Forty Sprague-Dawley male rats were randomly distributed into four groups: Group1 (Clinical control, n = 10); Group 2 (0.5% Ethylene Glycol + Vitamin D3, n = 10); Group 3 (1.25% Ethylene Glycol, n = 10); and Group 4 (5%Hydroxy L-proline, n = 10). Five animals from each group were euthanized after one week of follow-up (M1 Moment) and the remaining, after four weeks (M2 Moment). All animals underwent 24h urine dosages of calcium, oxalate, uric acid, citrate and serum creatinine. Histology and histomorphometric analyses were performed using Image J program in the hematoxylin-eosin stains. Calcium deposits in the renal parenchyma were quantified by PIXE technique (Proton Induced X-Ray Emission). RESULTS: 24h urinary parameters did not show any significant variations after 28 days of experiment except by hyperoxaluria that was significantly higher in Group 3. Histomorphometric analyses showed a significantly higher nephrocalcinosis in Group 2 (p<0.01). The calcium deposits in the renal parenchyma were 10 and 100 times higher in Group 2 in comparison to other groups in the M1 and M2 moments, respectively. CONCLUSION: The Group 2 (vitamin D3+Ethylene Glycol 0.5%) was the best model to induce nephrocalcinosis in rats after 28 days.(AU)

Correlation between the immunohistochemical expressions of MMP-1, MMP-7 and VEGF and prognostic factors in colorectal adenocarcinoma / Correlação entre as expressões imunohistoquímicas da MMP-1, MMP-7 e do VEGF no adenocarcinoma colorretal com fatores prognósticos

PURPOSE: To analyze the expression of metalloproteinase-1, metalloproteinase-7 and vascular endothelial growth factor (VEGF) in colorectal adenocarcinoma, and to correlate these with the clinical-pathological prognostic factors. METHODS: Tumor tissue from 82 patients was fixed in formalin and embedded in paraffin blocks. These samples were analyzed by means of the streptavidin-biotin immunohistochemical method, using the tissue microarray technique. Marker positivity was evaluated using categorical scores that determined cutoff percentages of stained tumor cells. Protein tissue expression was correlated with the variables of degree of cell differentiation, staging, disease-free interval, recurrence, survival and specific mortality. The Fisher exact and Kaplan-Meier tests were used to assess associations between the markers and the study variables. The log-rank and Wilcoxon tests were used to assess the significance of differences between curves of disease-free interval and survival. RESULTS: All tumors were positive for metalloproteinase-1; 50 (61 percent) were positive and 32 (39 percent) were negative for metalloproteinase-7; and 60 (74.1 percent) were positive and 21 (25.9 percent) were negative for VEGF. Correlation of marker expression, both in groups and individually, did not show statistical significance in relation to the degree of cell differentiation, staging, disease-free interval, survival or specific mortality. Recurrence showed a statistically significant correlation with positive expression of the three markers, when analyzed as a group (p = 0.038). CONCLUSION: The associated expression of metalloproteinase-1, metalloproteinase-7 and VEGF in colorectal adenocarcinoma is related to the incidence of disease recurrence.(AU)

OBJETIVO: Analisar as expressões da metaloproteinase-1, metaloproteinase-7 e do fator de crescimento endotelial vascular no adenocarcinoma colorretal e correlacionar com os fatores prognósticos clínico-patológicos. MÉTODOS: Foram analisados tecidos fixados em formol e dispostos em blocos de parafina dos tumores de 82 pacientes, por imunohistoquímica, pelo método da estreptavidina-biotina, usando-se a técnica de arranjo em matriz de amostras teciduais (tissue microarray). Na avaliação da positividade dos marcadores foi utilizado um escore categórico, que predeterminou o valor de corte na percentagem de células coradas do tumor. As expressões teciduais das proteínas foram correlacionadas com as varáveis representadas pelo grau de diferenciação celular, estadiamento, tempo livre de doença, recidiva, sobrevida e mortalidade específica. Foram empregados os testes exato de Fisher e de Kaplan-Meier para verificar as associações dos marcadores com as varáveis estudadas. Para testar a significância das diferenças entre as curvas do tempo livre de doença e da sobrevida foram utilizados os testes de longrank e Wilcoxon. RESULTADOS: A metaloproteinase-1 foi positiva em todos os tumores. A metaloproteinase-7 foi positiva em 50 (61 por cento) e negativa em 32 (39 por cento) tumores. O fator de crescimento endotelial vascular foi positivo em 60 (74,1 por cento) e negativo em 21 (25,9 por cento) tumores. A correlação das expressões dos marcadores realizada separadamente e em conjunto não apresentou significância estatística com o grau de diferenciação celular, estadiamento, tempo livre de doença, sobrevida e mortalidade específica. A recidiva apresentou correlação estatística significante com a expressão positiva dos três marcadores, quando foram analisados em conjunto (p = 0,038). CONCLUSÃO: As expressões associadas da metaloproteinase-1, metaloproteinase-7 e do fator de crescimento endotelial vascular no adenocarcinoma colorretal se relacionam com ...(AU)