Changes in structure, interstitial cajal-like cells and apoptosis of smooth muscle cells in congenital ureteropelvic junction obstruction

The goal of this study is to evaluate some structural changes in muscular, collagenous and neural components as well as expression of Cajal-like cells and apoptosis of smooth muscle cells in congenital ureteropelvic junction obstruction [UPJO]. Tissue specimens were obtained from 25 patients with UPJO and compared with normal ureteropelvic junction regions of 19 autopsies. In paraffin embedded sections the amount of Cajal-like cells, density of nerve fibers and smooth muscle cell apoptosis [using immunohistochemical staining] were determined. Collagen deposition and muscular components were stained by Trichrome-Masson staining and evaluated by image analysis techniques. Arrangement of muscular bundles was also evaluated qualitatively. The number of Cajal-like cells was significantly lower in patients than in controls. The apoptotic score and mean number of nerve fibers were not statistically different for the two groups. Arrangement of muscular fibers was more irregular in patients than in controls [P<0.001]. Collagen deposition was significantly higher in patients than in controls [P<0.001]. The mean amount of muscular component was lower in patients than in normal ones. [P= 0.09] We found significant pathologic changes in congenital ureteropelvic junction obstruction such as decrease in Cajal-like cells, increase in collagen deposition and irregular arrangement of muscle fibers

Alpha 1 antitrypsin deficiency in infants with neonatal cholestasis

Alpha 1-antitrypsin deficiency [A1ATD] is the most important indication for liver transplantation in children. The gene frequencies vary in different ethnic groups. In the present study, we attempt to determine the frequencies of the most common defective alleles, Z and S, in Iranian children suffering from idiopathic neonatal cholestasis. Eighty-seven infants were typed for Z and S alleles. In a single center study, 87 consecutive liver biopsies from infants with cholestasis were reviewed and patients with neonatal cholestasis enrolled in the study and cases with confirmed biliary tract atresia excluded. Formalin fixed paraffin embedded blocks were used for DNA extraction. AAT genotype was determined by polymerase chain reaction [PCR] assay and amplification of the two most common deficiency variants, S and Z alleles, and then sequencing of PCR products. There were 48 [55.2%] males and 39 [44.8%] females, with a median age of 60 days. Out of 87 of the study subject, 2 [2.2%] were heterozygous for the S allele, and no ZZ, SS or MZ individual was found in the patients. No other polymorphism was found in the sequencing results. In comparison to other populations, AAT deficiency seems not to be an important etiologic factor for neonatal cholestatic liver disease in Iran; however, further studies are recommended to estimate the true mutant gene frequencies