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Biomedical subjects

E Schwartz

Publications and source records attributed to E Schwartz.

At least 343 records · Page 19Linked to original sources
PubMed1980

Depressed serum somatomedin activity in beta-thalassemia.

We have found bioassayable somatomedin activity to be subnormal in 20 of 32 children and adults with beta-thalassemia. The levels were comparable to values reported in growth hormone-deficient subjects. Since patients with thalassemia are not growth hormone deficient, the data suggest the possibility of defective hepatic biosynthesis of somatomedin. Increased iron stores in these patients, who have secondary hemosiderosis of many organs, including the liver, may depress somatomedin activity. Therapy for one year with daily subcutaneous infusions of the iron-chelating agent deferoxamine had no effect on mean bioassayable serum somatomedin activity.

Adolescent↗
PubMed1980

Clinical features of thalassemia.

The thalassemia syndromes are an important group of diseases in childhood, frequently encountered in many ethnic groups worldwide. Heterozygotes are frequently misdiagnosed as having iron deficiency anemia, and the more severely affected homozygotes present major problems in management. Advances in prenatal diagnosis offer hope for prevention, while progress in transfusion therapy, accuracy of prediction of value of splenectomy, and chelation therapy offer improved quality and, perhaps, duration of life.

Child↗
PubMed1980

Effect of cetiedil on erythrocyte sickling: new type of antisickling agent that may affect erythrocyte membranes.

The antisickling effect of cetiedil, alpha-cyclohexyl-3-thiopheneacetic acid 2-(hexahydro-1H-azepin-1-yl)-ethyl ester, has been investigated. The concentration of cetiedil required for 50% inhibition of erythrocyte sickling was about 140 micro M. An antisickling effect was achieved regardless of whether cetiedil was added before or after deoxygenation. The minimal gelling concentration of deoxy Hb S was increased by less than 10% in the presence of 218 micro M cetiedil. The oxygen equilibrium curves of Hb S were not significantly affected by cetiedil. Erythrocytes treated with high concentrations of cetiedil were swollen and became spheroidal. The antisickling effects of cetiedil might be due to an effect on erythrocyte membranes.

Antisickling Agents↗
PubMed1980

Linkage of alpha G-Philadelphia to alpha-thalassemia in African-Americans .

We have studied the inheritance of the alpha-chain hemoglobin variant Hb G-Philadelphia (alpha 2(68 Asn leads to Lys)Beta 2) in two African-American families. Expression of the alpha-globin loci was monitored by the percentage of Hb G in these individuals. The variant represented approximately 33% of the total adult hemoglobin in some and 50% in others. alpha-Globin gene fragments were analyzed by using restricton endonucleases that cleave outside (EcoRI), within (HindIII), and between (Bgl II) the normal duplicated alpha-globin loci (alpha alpha/alpha alpha). Individuals having 33% variant lack one functioning alpha gene (alpha G/alpha alpha); those with 50% variant lack two genes, one missing on each chromosome (alpha G/alpha). Inheritance of alpha G was therefore linked to that of a chromosome with only one functional alpha-globin gene locus. This locus is probably the result of a nonhomologous crossover. Our results also suggest equal expression of the alpha-globin loci in humans because the percentages of the variant could be explained solely on the basis of the total number of alpha genes present. The percentages of Hb G as well as other hematologic data all were consistent with the number of alpha-globin genes identified by restriction endonuclease mapping. Gene mapping yields a more precise determination of the number of alpha-globin genes than does study of globin synthesis.

Africa↗
PubMed1980

Inclusions in red blood cells containing Hb S or Hb C.

To demonstrate and characterize red cell inclusions in 101 persons with Hb S or Hb C disorders three methods were used: (1) examination of unstained blood smears by dark field microscopy (DFM), (2) examination of blood smears after acid elution and staining (AE), and (3) measurement of membrane-associated denatured haemoglobin (MADH) in ghosts. The control group had inclusions in less than 5% of red cells by DFM and AE and the mean percentage of MADH per total cellular Hb was 0.030+/-0.016%. The highest percentages of red cells with inclusions and of MADH were present in clinically severe haemoglobin disorders, e.g. homozygous sickle cell disease (Hb SS) with less than 10% Hb F and Hb SOArab, with successively lower percentages in moderate to severe disorders, e.g. Hb SS-alpha thalassaemia, Hb-S-beta0 thalassaemia, Hb SC disease, and Hb SS with more than 10% Hb F, indicating agreement in results by three methods. In asymptomatic or mild disorders, e.g. Hb-S-beta+ thalassaemia, Hb CC, Hb AC and Hb AS, the results by AE and measurements of MADH were the same or similar to those in controls, while those by DFM were different. Of 56 patients with Hb SS or Hb SC, the group with functional asplenia had higher percentages of MADH and of red cells with inclusions than those with functioning spleens. Our study suggests that inclusions in sickling disorders may be due to denatured Hb S, with AE being the more accurate method for visualizing these inclusions, as results by this method correlate better with the amount of MADH than those by DFM.

Adolescent↗
PubMed1980

alpha Thalassemia and the expression of hemoglobin G-Philadelphia.

The findings presented for these two families help to explain the inheritance of alpha thalassemia, alpha-chain variants, and the relative expression of alpha genes. An 18.0-kb EcoRI fragment contains only one functional alpha gene, whereas a 20.5-kb fragment contains two. Individuals homozygous for the 18.0-kb EcoRI fragment also lack the 4.1-kb HindIII fragment that normally connects the centers of the duplicated alpha genes. These findings are consistent with a deletion involving the 5' alpha-gene locus. Presence of alpha G-Philadelphia in both families was found in association with the 18.0-kb EcoRI fragment; this short fragment was also found in an individual with alpha A. Inheritance of alpha G-Philadelphia at one alpha-gene locus was therefore also linked to the inheritance of alpha thalassemia due to a deletion involving the second alpha gene. The high percentage (46% to 48%) of alpha G found in some family members was due to alpha-thalassemia trait, or deletion of two alpha genes (-alpha G/-alpha); others with levels of variant of 32% to 34% were shown to have three functional alpha genes (-alpha G/alpha alpha). The genetic expression of the four normal alpha genes therefore appears to be equal and furthermore implies the existence of separate independently functioning transcriptional units for each of these genes in humans. It would be interesting to analyze the alpha genes in Afro-Americans reported to have alpha G-Philadelphia in the 20% to 25% range to determine whether the inheritance of alpha G can be linked to a normal alpha gene.

Base Sequence↗
PubMed1980

Aggregation of hemoglobin S and hemoglobin CHarlem with nonsickle hemoglobin in concentrated phosphate buffer.

The effect of HbA and HbF on both the aggregation and deaggregation of deoxy HbS and deoxy HbCHarlem in concentrated phosphate buffers was studied by a turbidimetric method. Although pure deoxy HbA is fully soluble in 2.4 M potassium phosphate buffer, the same concentration of deoxy HbAS was insoluble in the same buffer. Since there was little dissolved hemoglobin in the solute of a mixture of HbA and HbS, and since the intensity of turbidity was approximately twice that which would be expected from deoxy HbS alone, deoxy HbA must have coaggregated with deoxy HbS. Similar studies with mixtures of HbS and HbF showed different results. The rates of aggregation of deoxygenated mixtures of HbS and HbF were much slower than those of similar mixtures of HbS and HbA. Measurements of the absorption spectrum of the solute after centrifugation and the electrophoresis of both the aggregates and the solutes showed that a portion of the HbF was coaggregated with HbS, while some of the HbS was still in solution. The solubility of HbS and mixtures of sickle and nonsickle hemoglobins in 2.2 M phosphate buffer increased in the order of HbS, HbACHarlem, HbAS, HbCHarlem, HbSF, and HbFCHarlem.

Blood Protein Electrophoresis↗
PubMed1980

Application of gibberelic acid (GA) alone or together wih cytostatics in treatment of lung cancer.

Gibberelic acid (GA) was used alone or in combination with cytostatics (Vincristine, Cyclophosphamide, HN3), surgical treatment or radiotherapy, in treatment of 65 patients with lung cancer. The patinets were followed up from the end of 1972 until the end of 1977. It was found that the administration of GA, at the given doses, did not cause toxic effects in treated patients and it improved for shorter or longer period of time some metabolic functions and activity of hemopoiesis. Some analgetic effect(2) of GA was also registered.

Adult↗
PubMed1980

Alpha-gene deletions in black newborn infants with Hb Bart's.

The presence of increased Hb Bart's (gamma 4) in cord blood is believed to be an indication of alpha-thalassemia. We have used restriction endonuclease nalyses of DNA to compare the number of alpha-genes with the percentage of Hb Bart's in 6 older children who had Hb Bart's at birth and 17 newborns. Four children with > 2% Hb Bart's had Eco R1 alpha-gene patterns and hematologic data consistent with the presence of two alpha-genes, one per chromosome. Of the remaining 19 children, all of whom had < 2% Hb Bart's, 8 had 3, while 11 had 4 alpha-genes. Three infants with Hb Bart's between 1% or less Hb Bart's. infants with 3 alpha-genes may therefore have elevated or normal levels of Hb Bart's at birth. DNA analysis is the definitive method for the determination of heterozygous alpha-thalassemia syndromes in newborns.

Black People↗
PubMed1980

[The in vivo influence of gibberellic acid (GA3) on the phagocytic properties of peritoneal macrophages (author's transl)].

Different concentrations of gibberellin acid GA3 - 10.0 mg, 1.0 mg and 0.1 mg - were applied intraperitoneally to white mice of the SPF strain on four consecutive days. Following the last application we injected E. coli, P. aerug. and Pr. vulg. intraperitoneally into the peritoneum of these animals, in a quantity of 1.5-2.0 X 10(6)/0.5 ml of sterile phosphate buffer. The peritoneal macrophages obtained by puncturing the peritoneum of the animals killed under chloroform anaesthesia showed, as compared with those of the control animals statistically most significantly higher values (P < 0.001) of the phagocytic factor and phagocytic index as well as of the activity of the acid phosphatase. In the test animals which received gibberellin acid, the inhibition of the lysosomal activity of peritoneal macrophages as a result of the application of trypan blue did not reach the level which was found to exist in the control animals and those infected with B CG - Praha.

Animals↗