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Biomedical subjects

H Kaplan

Publications and source records attributed to H Kaplan.

At least 199 records · Page 11Linked to original sources
PubMed1979

Myeloproliferative disorders terminating in acute micromegakaryoblastic leukaemia.

Two cases of myeloproliferative disorder--one of myelofibrosis with agnogenic myeloid metaplasia and one of chronic granulocytic leukaemia terminating in acute micromegakaryoblastic leukaemia--are presented. The clinical course is described, and results are reported of morphological, cytometric, cytochemical and cytogenetic studies, as well as cell culture of blood cells in soft agar and in fluid medium.

Adolescent↗
PubMed1979

Unusual chemical properties of the amino groups of insulin: implications for structure-function relationship.

The chemical properties of the three amino groups of insulin were obtained at 10 and 37 degrees C using the competitive labelling technique with acetic anhydride as the labelling reagent. At 10 degrees C, pK values of 7.9, 7.2, and 7.8 were found for the glycyl A1, phenylalanyl B1, and lysyl B29 amino groups. When compared with standard amino compounds by means of a Brønsted plot, the two amino-termini were found to be 'super-reactive' and the lysyl epsilon-amino group buried. In the presence of carbon dioxide at physiological pH values, all three amino groups became much less reactive indicating that they had reacted to form carbamino derivatives. Above pH 8 the reactivities of the glycyl amino terminus and epsilon-amino group increase sharply indicating that insulin is undergoing a conformational change which is most likely a change in its association state. At 37 degrees C the amino groups do not titrate normally but exhibit sharp increases in reactivity over the physiological pH range with the midpoints in the pH reactivity profiles between pH values of 7.0 and 7.3. This behaviour is interpreted as a rapid disaggregation of insulin to form monomers as a result of the ionization of the amino groups. It is concluded that at physiological pH and temperature all three amino groups are deprotonated.

Acetic Anhydrides↗
PubMed1979

Pseudo-Chediak-Higashi anomaly in acute myeloid leukaemia. An electron microscopical study.

2 cases of acute myeloid leukaemia with inclusion bodies are presented. The inclusions were found mainly in the blast cells but could also be encountered in lymphocytes and plasma cells. Cytochemical and ultrastructural studies showed a great resemblance of these inclusions to the ones found in Chediak-Higashi anomaly, i.e., high acid phosphatase activity, varying in size of inclusions from clusters of small granules to hugh inclusion, sometimes found in vacuoles, featuring fusion of lysosomes.

Acid Phosphatase↗
PubMed1979

Phagocytosis of chrysotile fibers by pleural mesothelial cells in culture.

Pleural mesothelial cells (PMC) from the parietal pleura of rats were incubated in culture with UICC A chrysotile fibers. The sequence of events in phagocytosis was studied by electron microscopy: phases of attachment sequestration, and degranulation of lysosomal content into the phagocytic vacuole were observed. This demonstrates that PMC can engage in phagocytosis of chrysotile fibers.

Animals↗
PubMed1979

Hematologic values in healthy older people in the Negev area.

Of 1,500 volunteers aged 65 or more selected at random in the Negev area, 224 were found to be healthy and available for further examination. The population represented broadly the various ethnic groups among Jews in Israel. The mean hemoglobin level, hematocrit, red and white blood cell counts and differential count showed no differences other than those due to chance when compared with the corresponding values in a younger (20 to 48 years of age) group. The differences between men and women were similar to those found in the comparison group, with men having higher mean values for hemoglobin, hematocrit, and red blood cell count; in the study group, serum iron, total iron-binding capacity and percent saturation were higher in men in all age groups. No differences were found in mean values of white blood cell count and differential count within the study population. However, mean serum iron was lower, and mean platelet count, higher than in the younger comparison group. This survey supports the use of normal standards for adults when elderly patients are examined, regardless of different ethnic origin. However, the higher than normal platelet counts in subjects from Asia, Africa and Eastern Europe should be taken into account.

Age Factors↗
PubMed1978

Activation of teratocarcinoma-derived hemoglobin genes in teratocarcinoma-Friend cell hybrids.

Hybrid cells formed by the fusion of murine teratocarcinoma and Friend erythroleukemia cells synthesize hemoglobin in the presence of chemical inducers such as dimethylsulfoxide (DMSO). By making use of the fact that the parental teratocarcinoma and Friend cells carried different alleles at the locus coding for the alpha chain of hemoglobin, it was possible to demonstrate that the teratocarcinoma-derived genes for the globin alpha chains are genetically active in hemoglobin-synthesizing hybrid cells. In addition, evidence is presented suggesting that the teratocarcinoma-derived genes for the beta-globin chains may also be expressed in the hybrids. Apparently the teratocarcinoma-derived genome has become reprogrammed to express erythroid functions following fusion of the teratocarcinoma cell to the Friend cell.

Alleles↗
PubMed1978

A new double-labelling procedure for determination of amino acid composition: application to bacteriorhodopsin.

A new double-labelling procedure for amino acid analysis which requires only routine chromatographic equipment is described. When 1-fluoro-2,4-dinitro[3H]benzene is reacted with a mixture of 14C-labelled amino acids followed by reaction with the same 14C-labelled amino acid mixture diluted with an unlabelled sample of amino acids, the 3H:14C ratio in the resulting 2,4-dinitrophenyl (DNP) amino acid derivatives of the diluted sample will be increased in proportion to the quantity of unlabelled amino acid in the diluted sample. This procedure gave reliable results when applied to the known proteins insulin and lysozyme. The procedure is most advantageous when applied to amino acids which are unstable during acid hydrolysis or present in low molar fractions. When applied to the analysis of the bacteriorhodopsin in Halobacterium cutirubrum, this procedure showed the presence of one histidine residue and four tryptophan residues per mole protein but no cystine or cysteine; in general, the analyses obtained were consistent with those originally reported by Oesterhelt, D. and Stoeckenius, W. (1971) (Nature (London) New Biol. 233, 149-152) for bacteriorhodopsin of H. halobium.

Amino Acids↗
PubMed1978

Culture procedure of mesothelial cells from the rat parietal pleura.

Cultures were made of mesothelial cells obtained by scraping the parietal pleura of the adult rats. The growth was restricted to close polyhedric epithelial-like cells, forming a monolayer. The cellular proliferation continued until the 7th day, followed by a stationary phases. In subcultures the mesothelial cells kept their epithelial type. The cultures were stopped on the 20th day.

Animals↗
PubMed1977

A multicenter trial of sulindac in osteoarthritis of the hip.

Sulindac (cis-5-fluoro-2-methyl-l-[(p-methyl sulfinyl)-benzylidene]-indene-3-acetic acid) is a new nonsteroidal antirheumatic drug recently evaluated in a double-blind trial of 91 patients with hip osteoarthritis. Consecutive patients with documented flare following previous drug withdrawal were randomly assigned to one of 3 treatment groups: (1) sulindac given twice daily, (2) sulindac given 4 times daily, and (3) placebo. The dosage of sulindac, 100 to 300 mg daily, was adjusted according to patient global response and tolerance at 3- to 7-day intervals over 3 wk. Of 15 efficacy measurements evalulated, there was no difference between sulindac given 2 or 4 times daily, but differences were disclosed between one or both sulindac treatment groups and placebo in 11 of the 15 efficacy measurements (p less than 0.05, less than 0.01). The frequency of adverse reactions was of the same order for each treatment group. These included gastrointestinal upset, rash, and dizziness, usually transient and mild to moderate in severity. Serial laboratory studies revealed no evidence of renal, hepatic, or hematopoietic toxicity.

Adult↗