Modification of spontaneous renal lesion of APA hamsters by streptozotocin-induced diabetes

Syrian hamsters of the APA strain (APA hamsters) develop spontaneous mesangial thickening in the renal glomeruli from an early age. They also develop focal and segmental glomerulosclerosis (FSG) at and after 6 months of age. In this study, histopathological, immunohistochemical and lectin histochemical examinations were conducted to clarify the modification of the spontaneous renal lesions of APA hamsters by streptozotocin(SZ)-induced diabetes. Histopathological analysis revealed that the expansion of the mesangial region was more prominent and the thickening of the glomerular basement membrane (GBM) was weaker in SZ-treated animals than in non-treated ones. Immunohistochemical analysis suggested that type IV collagen and laminin were involved in the expansion of the mesangial region and thickening of the GBM. In lectin histochemical analysis, podocytes, capillary endothelial cells, GBM and a part of mesangial region of SZ-treated animals were positive for RCA₁₂₀ and GSL-I with neuraminidase-pretreatment although they were negative for these lectins in non-treated animals. These results suggest that the spontaneous glomerular lesion of APA hamsters is modified qualitatively and quantitatively by SZ-induced diabetes.     

Possible hereditary Y-chromosome instability

A 9 year old boy, born to a phenotypically normal, non-consanguineous couple was referred for clinical examination due to radio-ulnar synostosis. We made cytogenetic analyses to investigate the genotype-phenotype correlation. Chromosomal studies on the boy and his father revealed a very small Y chromosome in both cases, probably due to loss of the heterochromatic long arm segment. Repeated cytogenetic analysis of the boy was made, using QFQ, CBG, DA/DAPI and fluorescence in situ hybridization (FISH) methods with DYZ1 and DYZ3 probes. The results showed a likely mosaicism of cell lines with either a small Y or a normal Y found in the boy. The small Y appeared to be composed of double centromeric regions, without the heterochromatic segment of the long arm of the Y chromosome. The father refused re-analysis. These findings indicate an inherent instability of the Y chromosome resulting in a familial small Y. The radio-ulnar synostosis may be associated with excessive Y short arms.