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Biomedical subjects

M H Jonah

Publications and source records attributed to M H Jonah.

16 recordsLinked to original sources
PubMed1994

African-American factor VII-deficient variants in Georgia (FVII variants).

We studied African-American Factor (FVII)-deficient variants and carriers in Georgia by measuring their levels of FVII antigen (FVIIAG) and FVII procoagulant (FVIIC). Factor VIIAG was determined using enzyme-linked immunoassay (ELISA), whereas FVIIC was measured in two ways: 1) by fibrin clotting methods that employed human recombinant (HRFVIIC), human placental (HPFVIIC), rabbit brain (RBFVIIC), and bovine brain (BBFVIIC) thromboplastins; and 2) by an amidolytic method (AMFVIIC). Prothrombin time tests (PT) were also performed by standard methods. These 4 FVII-deficient patients and 3 carriers demonstrated the following results: PT: 18.2 +/- 6.5 sec; FVIIAG: 73.0 +/- 14.9%; HRFVIIC: 30.6 +/- 20.3%; HPFVIIC: 30.5 +/- 21.4%; RBFVIIC: 25.3 +/- 21.4%; BBFVIIC: 30.6 +/- 17.5%; AMFVIIC: 44.1 +/- 18.3%. We conclude that a group of clinically mild African-American FVII-deficient variants exists in Georgia. This group is characterized by the presence of FVIIAG and decreased FVIIC, using a variety of thromboplastins; and excellent correlation was noted for both human thromboplastins.

Antibodies↗
PubMed1992

Failure of microchromatographic measurement of fetal hemoglobin in beta zero thalassemia-hereditary persistence of fetal hemoglobin.

We report microchromatographic measurement of fetal hemoglobin (HbF) proportions in a 36-year-old African-American multigravida woman. At 34 weeks she delivered a 630-g male infant who subsequently did well. Hemoglobin electrophoresis of the hemolysate revealed nearly 100% HbF without HbA, an extremely unusual naturally occurring sample. Family studies revealed a combination of hereditary persistence of fetal hemoglobin (HPFH) and beta zero-thalassemia minor. Southern blot technique confirmed heterozygous alpha 2 thalassemia and HPFH but failed to identify the beta thalassemic lesion. The absence of HbA and the very high amounts of HbF led us to measure HbF by several methods to confirm the accuracy of microchromatography of HbF at values approaching 100%. HPLC revealed a 14% F1 suggestive of microchromatographic underestimation due to glycated HbF. We conclude that cation-exchange microchromatography and the Betke method of alkali denaturation underestimate HbF values as they approach 100% and do not recommend these procedures in this rare situation.

Adult↗
PubMed1986

Densitometry and microchromatography compared for determination of the hemoglobin C and A2 proportions in hemoglobin C and hemoglobin SC disease and in hemoglobin C trait.

Using both densitometry and anion-exchange microchromatography, we measured hemoglobin C (Hb C) and Hb A2 proportions in 11 patients, eight of whom had Hb AC, two Hb SC, and one Hb CC. For one patient with Hb SC, we made the determinations before and after a transfusion. The mean (and SD) for the sum of Hb C + Hb A2 by densitometry and anion-exchange microchromatography for the nine patients with Hb AC and Hb CC were 45 (18) and 40 (18)%, respectively (p greater than 0.1, r = 0.98); for the three determinations involving the two Hb SC patients, the respective proportions were 40 (9.9) and 38 (6.6)% (r = 0.88). Electrophoretic analysis of microchromatographic eluates from the Hb AC and Hb CC patients showed that 6% of the absorbance of the late high-ionic-strength eluate was due to Hb C, which was responsible for the statistically insignificant difference between densitometric and chromatographic values for Hb C + A2 values. Electrophoresis on cellulose acetate of concentrated eluates of the Hb C + A2 fraction from the two Hb SC patients revealed no contamination by Hb S. Evidently, microchromatography can be used to determine Hb C + A2 in patients with Hb C or Hb SC disease or Hb C trait.

Anemia, Sickle Cell↗
PubMed1985

The microchromatographic measurement of fetal hemoglobin levels in hemoglobin C-associated conditions.

We report the microchromatographic estimation of fetal hemoglobin (Hb F) in 3 conditions associated with hemoglobin C: hemoglobin C-hereditary persistence of fetal hemoglobin (Hb C-HPFH), homozygous hemoglobin C disease, and hemoglobin SC disease. In the case of Hb C-HPFH (Case 1) the Hb F level by alkali denaturation was 32.5% while the Hb F level by microchromatography was 35.3%. In both cases of homozygous Hb C disease and Hb SC disease the Hb F level by alkali denaturation was less than 1% and the microchromatographic Hb F level was 0.7%. We conclude that microchromatographic methods for determination of Hb F levels can be employed in the Hb C-HPFH, homozygous Hb C, and Hb SC conditions. To our knowledge, the microchromatographic determination of Hb F levels has not been applied previously to the Hb C-HPFH condition or Hb C disease.

Adolescent↗
PubMed1985

Estimation of highly increased concentrations of fetal hemoglobin in Fanconi's anemia.

We report a case of Fanconi's anemia with an extremely high proportion of fetal hemoglobin (Hb F). A three-year-old girl with multiple birth defects, mental retardation, and aplastic anemia consistent with Fanconi's anemia showed Hb AF by electrophoresis; the Kleihauer smear showed Hb F in 70% of her erythrocytes. Total Hb concentration was 34 g/L, mean corpuscular volume 119 fL. The proportion of Hb F was 45% by densitometry, 36% by radial immunodiffusion, and 30% by cation-exchange microchromatography. The Hb A2 was 0.5%; glycated Hb was 7.8% by affinity chromatography. Sample volume was insufficient for alkali denaturation. As exemplified with this patient, we recommend microchromatographic cation-exchange assay when Hb F exceeds 30% by densitometry. Here the effect of contamination by Hb A1 was lessened by the high proportion of Hb F. Cation-exchange microchromatography provides clinically relevant Hb F values more quickly than radial immunodiffusion and more conveniently than alkali denaturation.

Abnormalities, Multiple↗
PubMed1983

Proportion of glycosylated hemoglobin in erythrocytes of a person with hemoglobins A, S, and G Philadelphia.

The apparent proportion of column-chromatographically measured glycosylated hemoglobin in erythrocytes from an individual with hemoglobins A, S, and G was only 2.3% because the slow glycosylated variant hemoglobins were retarded in the column. In contrast, the value for glycosylated hemoglobin was 7.8% by a new cellulose acetate electrophoretic method that includes use of dextran sulfate buffer. The erythrocyte metalloprotein, carbonic anhydrase B, was shown to co-migrate with glycosylated hemoglobin by this technique, however. Thus carbonic anhydrase B, HbF, and HbA all have weak attraction for negative charges at acid pH. We believe that carbonic anhydrase B should contribute significantly (at least 10-20% absorbance) to the HbA1 by this electrophoretic method. We conclude that microcolumn chromatography should remain the method of choice for HbA1 determination, that subject-based reference intervals should be used for HbS or HbC heterozygotes, and that electrophoretic HbA1 methods should be reserved for use with both HbS and HbC homozygotes and HbSC disease.

Adult↗