PubMed Health⌕ Search

Biomedical subjects

H M Koenig

Publications and source records attributed to H M Koenig.

At least 37 records · Page 2Linked to original sources
PubMed1986

Erythropoiesis in infants of diabetic mothers.

Neonatal polycythemia is a well-established perinatal complication in infants of diabetic mothers (IDM). To investigate the regulation of erythropoiesis in these infants, we measured cord blood erythropoietin (EP) levels by a sensitive radioimmune assay and examined the growth of erythroid progenitor colonies in a series of IDM and control infants. Fifteen of 18 diabetic mothers were managed on a protocol emphasizing careful glycemic control throughout pregnancy; 10 had glycosolated hemoglobin values within the normal, nondiabetic range during the third trimester. Cord blood EP was elevated in one of 18 IDM and in two of 13 controls (p = NS). In IDM, cord blood EP values were higher in infants delivered following maternal labor and were inversely correlated with umbilical artery pH (r = -0.72; p = 0.006). Growth of burst forming units-erythroid was similar in IDM and controls in the presence of 0.1 to 2.0 U of exogenous EP per ml of methylcellulose medium. Individual infants tended to respond consistently over the entire range of EP doses tested. The number of burst forming units-erythroid observed did not correlate with cord blood EP, birth weight, or neonatal hematocrits. We conclude that: umbilical cord blood EP levels are generally normal in IDM delivered by mothers in whom good glycemic control is maintained throughout gestation, cord blood EP values are strongly influenced by perinatal events, and the response of erythroid progenitors to EP is intrinsically normal in IDM. These data suggest that polycythemia is an adaptive response in IDM and is not associated with a primary abnormality in erythropoiesis.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Glucose↗
PubMed1983

Free erythrocyte protoporphyrin (FEP) I. Normal values for adults and evaluation of the hematofluorometer.

Since the early 1970s, measurement of free erythrocyte protoporphyrin (FEP) (by microextraction or by hematofluorometer) has been widely used to screen for lead poisoning and to evaluate microcytic red blood cell (RBC) disorders in children. However, published information on normal values for FEP, performance of the hematofluorometer, and usefulness of FEP in classifying microcytic RBC disorders in adults is scant. In an adult population with normal hematocrit and MCV and normal values for serum ferritin, blood lead level, and serum bilirubin, we obtained normal hematofluorometer FEP levels of less than 30 micrograms/dL for men, and less than 40 micrograms/dL levels for women. We have evaluated a hematofluorometer against a standard microextraction procedure and feel that the hematofluorometer is superior for clinical laboratories if elevated FEPs are confirmed by retesting with washed RBC. In the second part of this paper we demonstrate the usefulness of the FEP in classifying microcytic RBC disorders in adults.

Adult↗
PubMed1983

Free erythrocyte protoporphyrin (FEP) II. The FEP test is clinically useful in classifying microcytic RBC disorders in adults.

Microcytic red blood cells (RBC) are commonly encountered in clinical medicine and are caused by disorders of heme synthesis [usually iron deficiency anemia (IDA) or anemia of chronic disease (ACD)] or disorders of globin synthesis (usually thalassemia syndromes or HbE). Using the clinical history and standard laboratory tests (hematocrit, per cent saturation of transferrin (% sat), serum ferritin, Hb electrophoresis, HBA2, and HbF) we classified 198 adults with microcytic RBC as follows: 48 IDA, 11 probable IDA, 11 iron-deficient erythropoiesis without anemia, 13 ACD, 42 alpha-thalassemia trait, 35 probable alpha-thalassemia trait, 20 beta-thalassemia trait, and 15 unclassified. In addition, we demonstrated that the FEP test reliably (83-90% of the time, depending on FEP methodology) classifies microcytic RBC states into disorders of heme synthesis vs. disorders of globin synthesis. Because of reliability and ease of measurement, we recommend the hematofluorometer FEP as the first step in the clinical laboratory evaluation of microcytic RBC disorders in both adults and children.

Adolescent↗
PubMed1982

The laboratory evaluation of microcytic red blood cells.

Microcytic red blood cell states are common clinical problems in both adult and pediatric age groups. The recent widespread availability of electronic blood cell counters for performing routine blood counts has increased the detection of microcytic red blood cells. Physicians must workup both symptomatic and asymptomatic patients with microcytic red blood cells before they can initiate proper therapy and/or counseling. The purpose of this review is threefold: (1) to discuss the causes of microcytic red blood cells in terms of disorders of decreased heme production vs. disorders of decreased globin production, (2) to review the clinical laboratory tests useful in differentiating microcytic red blood cell states, and (3) to present a practical approach for the laboratory workup of microcytic red blood cells.

Adolescent↗
PubMed1980

Switching of the nonallelic forms of fetal hemoglobin during late gestation.

The gamma chains of human fetal hemoglobin occur in two nonallelic forms, designated G gamma and A gamma, which differ from one another in having either glycine or alanine as their 136th residue respectively. In newborns, G gamma comprises about 75% of the total gamma chains, while in adults, G gamma comprises about 40% of the total gamma chains. The timing of the switching events that lead to the alteration of the rates of production of G gamma and A gamma are still unknown. Umbilical cord red blood cells from term infants were separated by density gradient fractionation into four age-dependent fractions. Red blood cell size and reticulocyte content decreased and the percent fetal hemoglobin increased with increasing gradient densities, confirming age-dependent density separation. The percent G gamma was determined by two methods on fractionated cord red blood cells to determine if the switch in the production ratio of the nonallelic forms of gamma chains began during late gestation. The G gamma content of fetal hemoglobin was found to decrease with decreasing red blood cell age, demonstrating that the switch from predominately glycine-containing gamma chains to predominately alanine-containing gamma chains begins during late gestation.

Blood Protein Electrophoresis↗
PubMed1980

Unequal crossing-over: a common basis of single alpha-globin genes in Asians and American blacks with hemoglobin-H disease.

The alpha-globin genes of five black Americans, two Chinese, and five Filipinos with HbH disease (an alpha-thalassemia state in which there is a single functional alpha gene) were analyzed by restriction endonuclease techniques. All subjects were found to have one chromosome 16, lacking both alpha genes, and another containing a single alpha gene (--/-alpha). Restriction endonuclease patterns of the DNA obtained from all 12 subjects were identical and compatible with unequal crossing-over as the mechanism of origin of the single alpha gene in these individuals.

Black People↗
PubMed1980

Bone marrow and lymph node findings in a fatal case of Kawasaki's disease.

Since the initial description in 1967, the clinical and laboratory features of Kawasaki's disease (KD) have been well documented. We studied a patient with KD who recovered from the acute phase of the disease, but who subsequently died at home from coronary arteritis. We describe this patient because of bone marrow and lymph node findings that have previously received little attention in the English-language literature.

Arteritis↗
PubMed1979

Platelet-associated immunoglobulin G in childhood idiopathic thrombocytopenic purpura.

Childhood ITP is an acquired hemorrhagic disorder with a heterogeneous clinical course. We measured PAIgG levels in 20 children with ITP (7 acute, 13 chronic). Both groups had significantly greater PAIgG values than age-matched normal subjects and thrombocytopenic controls (P less than 0.001). In addition, PAIgG values in chronic ITP were significantly lower than those in acute ITP (P less than 0.003). Serial PAIgG values were obtained in some patients; most returned to normal in association with clinical recovery. The measurement of PAIgG is useful in the diagnosis and follow-up of childhood ITP. PAIgG values may assist in differentiating acute and chronic disease in children.

Acute Disease↗
PubMed1979

Heterogeneity of fetal hemoglobin in severe alpha-thalassemia.

The heterogeneity of residue 136 of the gamma-chain of human hemoglobin has been determined for a patient afflicted with severe alpha-thalassemia. Separation of the cord blood sample into the various constituent hemoglobins A, F, FI and Bart's were done on a column packed with DEAE Sephadex. The amount of glycine or alanine at position 136 was determined for hemoglobins F, FI and Bart's. The ratios determined for all three hemoglobins indicated that the G gamma/A gamma ratio is the same for all three fractions and is similar to that observed in normal cord blood samples.

Adult↗
PubMed1979

Immune suppression of erythropoiesis in transient erythroblastopenia of childhood.

Serum and IgG from four children with transient erythroblastopenia of childhood (TEC) was tested to see what effect it would have on development of erythroid colonies from bone marrow mononuclear cells. Serum and IgG specimens obtained at the time of diagnosis uniformly suppressed erythroid colony development from CFU-E. Washed bone marrow mononuclear cells from a child with TEC failed to grow in the presence of his own serum, but grew normally in the presence of isologous serum. Serum specimens obtained from patients after recovery from TEC had no effect on erythroid colony development. The anemia of TEC appears to be due to transient immune suppression of erythroid colony development.

Anemia, Aplastic↗
PubMed1979

Alpha-thalassemia in blacks is due to gene deletion.

We used molecular hybridization to test if alpha-thalassemia is due to gene deletion in the black. In 10 families with clinically well-defined alpha-thalassemia-1 (alpha-thal-1), hydribization of alpha-globin cDNA was reduced to the same level as that found in Asians with alpha-thal-1, where two of the four normally present alpha-globin genes are deleted. A black child with hemoglobin H (Hb H) disease also has three globin genes deleted, as do Asian patients with Hb H disease. We conclude that alpha-thalassemia in the black is most commonly due to gene deletion.

Black People↗
PubMed1978

Prenatal diagnosis of hemoglobin H disease.

Hemoglobin H disease was diagnosed prior to the twenty-second week of gestation in a pregnancy at risk for homozygous alpha-thalassemia using the technique of DNA-DNA hybridization. Fetal DNA was obtained from amniotic fluid fibroblasts obtained during the thirteenth week of gestation and grown in culture. The fetal fibroblast DNA was hybridized to radioactive alpha-globin cDNA. The number of alpha-globin genes present in the fetus was determined by comparing results of hybridization studies on the fetal DNA to similar studies on subjects with well-defined alpha-thalassemia syndromes and with normal subjects. The diagnosis of hemoglobin H disease was confirmed at birth by studies of the cord blood. This study confirms the ability of DNA-DNA hybridization techniques to distinguish the three-gene defect of hemoglobin H disease from the lethal four-gene defect of homozygous alpha-thalassemia.

Alpha-Globulins↗