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Biomedical subjects

C A Talacki

Publications and source records attributed to C A Talacki.

5 recordsLinked to original sources
PubMed1991

The Xmn I site (-158, C----T) 5' to the G gamma gene: correlation with the Senegalese haplotype and G gamma globin expression.

There are three major African haplotypes associated with the sickle mutation: Benin (#19), Senegalese (#3), and Central African Republic (#20). Previous studies have suggested that the Xmn I site (-158 bp 5' to the G gamma gene) is associated with elevated levels of G gamma and with the Senegalese haplotype, while other investigators questioned this association. In order to clarify the issue, we have determined beta haplotypes, tested for the presence of the Xmn I site, and measured Hb F and G gamma expression levels in 143 American Black patients with sickle cell anemia. Haplotypes were determined using eight polymorphic sites in the beta-like globin gene cluster: Hinc II 5' to epsilon, Hind III in IVS-II G gamma and A gamma, Hinc II within and 3' to psi beta, Ava II in IVS-II of beta, and Hpa I and Bam HI 3' to beta. The G gamma /A gamma ratio was analyzed by high performance liquid chromatography using a C18 column. The Xmn I site was present in all 31 chromosomes with the Sengalese haplotype. Of the remaining 255 chromosomes with other haplotypes, only 2 (0.8%) had the Xmn I site present. There was significant correlation between the presence of the Xmn I site and increased G gamma /A gamma ratio in a dose-dependent manner. The Hb F level was not significantly increased in the presence of the Xmn I site. The data indicate that the Xmn I site maintains a G gamma /A gamma ratio typical of fetal life but does not necessarily cause elevation of Hb F. The latter seems to depend on factors other than the Xmn I site.

Adolescent↗
PubMed1990

Modified method of exchange transfusion in sickle cell disease.

The treatment of various complications of sickle cell disease has included red cell exchange in the past, and the development of automated pheresis equipment has greatly simplified such exchanges. Traditionally, the patient's red cells have been exchanged while their plasma was returned to them. Recently, plasma factors have been thought to play a role in the pathogenesis of vasoocclusive events. Therefore, we performed whole blood exchange, which consisted of replacement of the patient's plasma with albumin and saline in addition to the usual replacement of erythrocytes. A total of 32 whole blood exchanges were performed on 12 patients with a variety of complications of their disease. The procedure was done using standard pheresis equipment and was relatively simple to perform. There were no serious complications and the clinical outcome was good with 10 out of 12 patients experiencing improvement.

Adolescent↗
PubMed1990

Beta-globin gene cluster haplotypes in Hb C heterozygotes.

Previous work has suggested that the beta C mutation arose on a relatively rare beta A chromosome with a unique haplotype, and these data have been used to postulate a single origin of the beta C allele. Most characteristic of this haplotype has been the absence of a Hpa I recognition site 3' to the beta-globin gene. We studied 40 patients with Hb SC, 11 with Hb AC, and one with Hb CC. Complete haplotyping was possible on 44 beta C alleles and 3' haplotyping was possible on an additional four beta C alleles. Our results support the predominence of a unique beta C haplotype which is characterized by the absence of the Hpa I site. However, one patient who was homozygous for Hb C had one beta C allele with an atypical haplotype which contained the Hpa I site. It is unclear at this time whether or not this represents a second origin of the beta C mutation.

Anemia, Sickle Cell↗
PubMed1989

The prevalence of avascular necrosis in sickle cell anemia: correlation with alpha-thalassemia.

The purpose of the present study was to investigate the effect of alpha-thalassemia on the prevalence of avascular necrosis in 52 adult patients with sickle cell anemia. alpha-Globin genotypes were determined by restriction endonuclease mapping of genomic DNA extracted from peripheral blood leukocytes. Radiographs of humeral and femoral heads were interpreted by two radiologists who were not aware of the clinical picture and the genotype of the patients in the study. We present data showing that there is a significant positive correlation between alpha-gene deletion and the prevalence and extent of avascular necrosis in our patient population.

Adult↗