RESUMO
OBJECTIVES: Concentrations of O(2) and CO(2) in the fetal circulation differ to that in maternal blood. Previous studies done in algae demonstrate the functional role of Rh antigen as CO(2) transporter. As a preliminary study, it was the aim of this project to compare the expression of Rh polypeptides on cord and adult red blood cell progenitors during ex vivo proliferation and differentiation of CD34(+) cells during erythropoeisis. MATERIALS AND METHODS: CD34 positive hematopoeitic progenitor cells were isolated from umbilical cord blood and adult peripheral blood using an immunomagnetic system and cultured in serum free medium containing erythropoietin in order to compel them along the erythroid lineage. Cultured cells were analyzed for cell surface marker expression by flow cytometry, using monoclonal antibodies to RhAG, Glycophorin A, Rh polypeptides, CD47 and Band 3. Cytospin analysis was also done to study the morphology of cultured cells. RESULTS: The appearance of cell surface markers analyzed on different days of culture varied slightly between samples. There was no evidence to suggest that RhAG, GPA, CD47 and Band 3 expression was any different between adult and cord derived cells. Nevertheless, the results of Rh antigenic expression suggest a reasonable difference between the two groups with adult sample derived cells showing higher and earlier expression than cord blood derived cells. These preliminary findings require further investigation. CONCLUSION: Comparing the expression of cell surface markers especially Rh polypeptides between adult and cord blood derived erythroid progenitors might assist in discerning their functions and could be valuable in the study of erythropoeisis.
RESUMO
Renal biopsy is indicated in all cases of renal transplants showing renal dysfunction. This not only helps in the diagnosis but also in the institution of proper management. Study of sequential biopsies is essential for establishing the cause of renal dysfunction, evaluation of the effect of treatment and the progress of the disease. This report is based on the study of 14 samples (including three nephrectomy specimens) belonging to six patients who underwent two or more sequential renal transplant biopsies at the Salmaniya Medical Centre, Bahrain, between 1995-2000 because of deteriorating renal functions. Based on the sequential biopsies, the graft dysfunction was attributed to rejection in four cases and recurrence of primary glomerular disease in two. An important finding in this series is one case of type I membranoproliferative glomerulonephritis due to hepatitis C noticed five years after transplant and two cases of acute vascular rejection superimposed upon chronic rejection.
