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D Radivojević

Publications and source records attributed to D Radivojević.

24 records · Page 2Linked to original sources

[Results of kidney transplantation at the Institute of Urology and Nephrology of the Serbian Clinical Center in Belgrade].

UNLABELLED: Over the period 1980-1992 256 kidney transplantations were carried out in the Institute of Urology and Nephrology, Clinical Centre, Belgrade: 105 (41%) from cadaveric and 151 (59%) from alive related donors. The first kidney transplantation was performed in our Institution in 1974; however, in the first decade only 27 kidney transplantations were performed. Since 1987, thanks to an increasing number of living kidney donors, the number of transplantations continually increased, and after that period an average of 30 kidney transplantations are performed annually (Figure 1). The aim of the study was to establish the survival of patients and grafts, and factors influencing this survival, as well as to determine the causes of patients' death and graft loss. All the patients were followed-up in our outpatient department within at least 5 years to maximum 17 years. Drug combination therapies were changed in the observation period. From 1983 cyclosporin A (CyA) was added to azathioprine (Aza) and prednisolone (Pr). An increasing number of patients with high immunological risks necessitated the strongest initial immunosuppressive treatment with ALG in addition to Aza and Pr. CyA in a dose of 8 mg/kg b.w. was introduced when serum creatinine concentration fell below 300 mumol/L. The triple treatment including CyA, Aza and Pr was the most common maintenance immunosuppressive therapy in our patients. RESULTS: One and five years survived 95% and 75% of patients, and 84% and 52% of grafts. In assessing the impact of donor source, the year of transplantation, and age of donors we obtained the following results: Living related grafts survived better than cadaver grafts, especially during the first posttransplantation year (Figure 2). Furthermore, graft survival rates from 1987 to 1992 were significantly better than those from early period i.e. 1980 to 1986 (Figure 3). The significantly worse survival rate for grafts from donors older than 60 was noted than for grafts from younger donors. Searching for factors influencing the survival, non immunological and immunological differences between donors and recipients were analyzed. Our analysis showed that 50 living related donors were older than 60. In addition, the majority of them were 20 years older than their graft recipients. Two and more HLA mismatches were observed in 46% of our transplant patients, and 20 patients were highly sensitized. However, the immunological risks were higher in living related transplantations: different ABO blood groups, historical positive cross match reaction between donors and recipients (Table 1). A multivariate analysis using Cox proportional hazards model was performed to determine the important independent predictors of graft survival, and it revealed the following factors (Table 2): number of acute rejections, graft function at the end of the first month and until the end of the first posttransplant year, donors' age, and age and sex differences between donors and recipients. The occurrence of acute rejection at any time had a significant negative effect on graft survival. Since better HLA matching is likely to mean less early rejection it could be concluded that HLA matching influenced graft function and survival in our patients. Absence of acute rejection and delayed graft function or acute tubular necrosis were associated with an improvement of the graft function based on serum creatinine concentration, indicating that delayed graft function also influenced graft survival. The relative risk of graft loss was 2 times higher for patients receiving graft from donors older than 60. Until December 1997, when our analysis was done, of 256 kidney transplant patients 156 lost their grafts. The major causes of graft loss (Table 3) in the early period from 1980 to 1986 were non immunological such as acute tubular necrosis, vascular thrombosis and patients death with functioning graft. (ABSTRACT TRUNCATED)

Adolescent↗

[Deletions in the dystrophin gene and its phenotype expression].

About 60% of both Duchenne's muscular dystrophy (DMD) and Becker's muscular dystrophy (BMD) is due to deletions of dystrophin gene. For cases with deletion mutations the "reading frame" hypothesis predicts that deletions which result in disruption of the translation reading frame prevent production of stable protein and are associated with DMD. In contrast, intragenic deletions that involve exons encoding an integral number of triplet codons maintain proper reading frame. The resulting abnormal proteins are stable and partially functional, resulting in a milder and more variable BMD phenotype. To test the validity of this theory,we analyzed 40 patients-19 independent deletions at the DMD/BMD locus. Clinical/molecular correlations based on the altera-tions of the reading frame were valid in 69.2% of cases. After exclusion of: --2 patients with del 3-6 (with no consistent clinical expression); --1 DMD patient with large in-frame deletion; --2 patients that were too young to be classified; --4 patients in whom it was impossible to identify the extent of deletion (del 47 and del 44-45), the correlation between deletion and clinical severity was as predicted in 92.4% of cases. The present data should be useful in establishing the prognosis in individual patients even in sporadic cases with no affected relatives.

Dystrophin↗

[Relation between gene mutations and pancreatic exocrine function in patients with cystic fibrosis].

Cystic fibrosis (CF), is the most common autosomal-recessive disease in Caucasians, with an incidence of approximately 1:2500 live births and a carrier frequency of approximately 4-5%. Causes of the disease are mutations in the CF gene which is located on chromosome 7 (region 7q31). Although a single mutation, a deletion of phenylalanine at position 508 (DF508) in exon 10, accounts for almost 70% of all CF chromosomes, over 900 other mutations have been identified in this large gene. CF gene encodes a membrane protein, which functions as aion channel- CFTR (cystic fibrosis transmembrane regulator protein). The exocrine pancreas is a gland that secretes water, enzymes and electrolytes into the intestinal lumen. These enzymes are needed for the normal digestion of food, and their reduced secretion in cystic fibrosis will cause malabsortion and malnutrition in CF patients. Pancreatic dysfunction in CF begins in uteri. Most patients with CF typically present insufficient pancreatic exocrine function (PI phenotype) and 10-15% of CF patients are pancreatic sufficient (PS phenotype). It has been shown elsewhere that the pancreatic function status in CF could be correlated to mutations in the CFTR gene. To determine the relation between genotype and pancreatic status, we analyzed 32 CF patients in whom both CF gene mutant alleles were identified (Table 1). Patients included in this study attended the Paediatric Department of Mother and Child Health Institute in Belgrade. The diagnosis was based on typical clinical manifestations and high levels of sweat chloride concentration (higher than 60 mmol/L). Of the 32 patients studied, only one (3.12%) was PS and the rest (96.88%) had PI phenotype. For each CF genotype the number of patients who were PI or PS is given in Table 1. The most striking observation was that all given genotypes correlated with either PI or PS, but not with both. On the basis of both preceding hypotheses and our present data (Table 2 and Table 3), it was possible to classify mutations as "severe" or "mild" with respect to pancreatic function (Table 4). This study strengthens the hypothesis that pancreatic function status in CF is genetically determined by specific mutations at the CF locus. Our data also strongly support the hypothesis that, with respect to pancreatic function, "mild" mutant alleles confer a higher residual CFTR activity than do "severe" mutant alleles. Although PS occurs in patients who have one or two "mild" mutations, PI occurs in patients who are homozygous or who are genetic compounds of two "severe" mutant alleles.

Adult↗