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Biomedical subjects

H Kazazian

Publications and source records attributed to H Kazazian.

6 recordsLinked to original sources
PubMed1987

Linkage analysis of neurofibromatosis.

Linkage analysis of neurofibromatosis was performed using genes on chromosomes 1, 8, 11, and 12. No linkage was found between NF and C-myc, AT 3, IGF-1, PTH, and gamma globin genes. Evidence for linkage was found between C-ets 1, on the long arm of chromosome 11 and NF in two families with a lod score of 1.88 at theta = 0. More families are being studied to confirm this linkage.

Chromosomes, Human, Pair 11↗
PubMed1986

Chinese A gamma fetal hemoglobin: C to T substitution at position-196 of the A gamma gene promoter.

The molecular basis for the hereditary persistence of fetal hemoglobin (HPFH) phenotype was studied in a Chinese individual who was heterozygous for a nondeletion form of A gamma-HPFH. Both allelic A gamma-globin genes were isolated by molecular cloning and subjected to nucleotide sequence analysis. One A gamma gene promoter showed a cytosine to thymine transition at position -196, whereas the other promoter was normal. This mutation at position -196 has now ben found in unrelated individuals with the A gamma-HPFH phenotype from Italy, Sardinia, and China, suggesting that it may have arisen independently. The implications of this mutation for models of fetal globin gene switching are discussed.

Adult↗
PubMed1979

Oxygen transport in a woman with hemoglobin Hope/beta+ thalassemia.

Because their blood may "unload" oxygen more readily than normal, people with hemoglobin of low oxygen affinity might be expected to be anemic. We have studied a woman with hemoglobin Hope/beta+ thalassemia, whose hemoglobin level was 10.4 to 12.3 gm/dl (normal 14 +/- 2) despite a P50 of 41 mm Hg (normal 26). Her cardiac index was normal, yielding a calculated mixed venous PO2 of 51 mm Hg (normal 34 to 49). Oxygen transport in patients with low oxygen affinity can be maintained by a variety of homeostatic responses, only one of which is altered erythropoiesis.

Adult↗
PubMed1977

Postsynthetic deamidation of hemoglobin Providence (beta 82 Lys replaced by Asn, Asp) and its effect on oxygen transport.

Carriers of hemoglobin Providence have three types of beta chain in their hemolysates. The two abnormal chains have asparagine (Providence N, Prov N) or aspartic acid (Providence D) at position beta 82, instead of lysine. In vitro, only two beta chains are synthesized by reticulocytes of carriers, betaA and betaProv N. In vivo studies showed that the specific activity of Providence N was initially 10-fold higher than that of Providence D; the specific activities of the two labeled hemoglobins were approximately equal 5 wk after injection of isotope. Oxygen affinity of carriers' blood was somewhat increased, but they were not polycythemic. The affinity of the purified hemoglobins Providence was decreased. Addition of 2, 3 diphosphoglycerate had little effect on the affinity of either hemoglobin component, and addition of inositol hexaphosphate produced no change in the affinity of Providence D. These studies demonstrate that Providence N is deamidated to Providence D during the life span of the erythrocyte, and suggest this finding may represent only an easily observed prototype of posttranslational modification of proteins in general. Despite and abnormal P50 of the blood, oxygen transport is probably normal in carriers of the abnormal hemoglobins.

Adolescent↗