Platelet enzyme abnormalities in leukemias.

Aim of the Study: The aim of this study was to evaluate platelet enzyme activity in cases of leukemia. Materials and Methods: Platelet enzymes glucose-6-phosphate dehydrogenase (G6PD), pyruvate kinase (PK) and hexokinase (HK) were studied in 47 patients of acute and chronic leukemia patients, 16 patients with acute myeloid leukemia (AML)(13 relapse, three in remission), 12 patients with acute lymphocytic leukemia (ALL) (five in relapse, seven in remission), 19 patients with chronic myeloid leukemia (CML). Results: The platelet G6PD activity was significantly low in cases of AML, ALL and also in CML. G6PD activity was normalized during AML remission. G6PD activity, although persistently low during ALL remission, increased significantly to near-normal during remission (P < 0.05) as compared with relapse (P < 0.01). Platelet PK activity was high during AML relapse (P < 0.05), which was normalized during remission. Platelet HK however was found to be decreased during all remission (P < 0.05). There was a significant positive correlation between G6PD and PK in cases of AML (P < 0.001) but not in ALL and CML. G6PD activity did not correlate with HK activity in any of the leukemic groups. A significant positive correlation was however seen between PK and HK activity in cases of ALL remission (P < 0.01) and CML (P < 0.05). Conclusions: Both red cell and platelet enzymes were studied in 36 leukemic patients and there was no statistically significant correlation between red cell and platelet enzymes. Platelet enzyme defect in leukemias suggests the inherent abnormality in megakaryopoiesis and would explain the functional platelet defects in leukemias.

Isoenzyme and molecular characterization of Entamoeba histolytica and Entamoeba dispar isolates from symptomatic and asymptomatic subjects.

AIM: To correlate the clinical features of amebic infections with the characteristics of Entamoeba culture isolates of stools. METHODS: Isolates from seven irritable bowel syndrome (IBS) patients, four asymptomatic cyst passers (ACP) and five patients with invasive amebic disease were subjected to hexokinase polyacrylamide electrophoresis (HK-PAGE) and their DNA subjected to restriction fragment (RF) analysis of amplified polymerase chain reaction (PCR) products. These findings were correlated with anti-amebic serology. Two axenic pathogenic strains (HM1:IMSS, NIH:200) and one xenic nonpathogenic strain (SAW1734) were used as standards. RESULTS: All isolates from IBS patients as well as ACP had slow-moving (nonpathogenic) band pattern, whereas those from patients with invasive disease had fast-moving (pathogenic) band pattern on HK-PAGE. Serological data using EIA and RF patterns of PCR-amplified genome corroborated these results. CONCLUSIONS: Our results support the view that there are two species of Entamoeba infecting humans--E. histolytica(pathogenic) and E. dispar (nonpathogenic), and HK-PAGE of culture isolates can differentiate between them.

Differences in enzyme activity and biological behavior of three leishmania promastigotes isolated from patients with zoonotic cutaneous leishmaniasis

Zoonotic cutaneous leishmaniasis [ZCL] is reported to cause a spectrum of clinical manifestations. To unravel some of the mechanisms associated with different disease manifestations, enzyme activities were compared among the promastigotes of leishmania isolated from three clinically different forms of ZCL from Isfahan, central Iran. Specific activities of glucose-6-phosphate dehydrogenase, hexokinase, lactate dehydrogenase and acid phosphatase in the promastigotes isolated from a scaly flat ulcer were 5.5, 2.2, 1.6 and 2.6 folds greater respective to those isolated from a small papular lesion. The activity of these enzymes in the promastigotes isolated from a volcano-shaped lesion was notably higher than those isolated from a papular lesion, but lower than those isolated from a scaly flat ulcer. Significant differences were not observed in alkaline phosphatase activity of different isolates. These results may indicate that differences in the clinical manifestation of the lesions in ZCL might be related to certain metabolic pathways of the parasites, growth kinetics in NNN medium and the course of infection in BALB/C mice

Caracterizaçäo isoenzimática da hexoquinase no desenvolvimento de Plebeia droryana (Hymenoptera, Apidae) e sua relaçäo com a atividade de vôo / Isoenzymatic characterization of hexokinase in the development of Plebeia droryana (Hymenoptera, Apidae) and its relation with flight activity

A enzima Hexoquinase foi estudada em P. droryana por meio de eletroforese em gel de amido agarose. Três regiöes anódicas com atividade enzimática foram observadas durante o desenvolvimento. A hexoquinase-1 (HK-1), cuja intensidade de coloraçäo aumenta de larva até adulto, provavelmente relacionada ao fornecimento de energia para os músculos torácicos de vôo e, conseqüentemente, com a atividade de vôo nesta espécie. A hexoquinase-2 (HK-2), que alcança intensidade máxima em pupa de olho marrom claro e hexoquinase-3 (HK-3), que alcança seu pico máximo de intensidade em imago e näo é observada na fase adulta. Esta isoenzima deve ter funçäo importante na metamorfose desta espécie.

Variations in isoenzymes of cloned & uncloned axenic Entamoeba histolytica without bacterial association.

Five clones of axenic E. histolytica (HMI) grown as discrete colonies in semisolid agar medium were adapted in liquid medium and labelled as HMI-C121, HMI-C131, HMI-C143, HMI-C144 and HMI-C145. Isoenzymes of these 5 clones of E. histolytica (HMI) were investigated in starch gel electrophoresis. There were no differences in the electromobility of maleate NADP oxidoreductase and glucosephosphoisomerase amongst the five clones and uncloned cultures of axenic E. histolytica. The relative electromobility (rf) of a single phosphoglucomutase (PGM) band of uncloned Mexican E. histolytica (HMI) and Indian axenic E. histolytica (KCG: 0986: 11) cultures and cloned E. histolytica HMI-C121, HMI-C145 was 0.087 while a single PGM band of uncloned E. histolytica (NIH: 200) and cloned E. histolytica HMI-C131, HMI-C143 and HMI-C144 cultures had rf of 0.075. Isoenzyme characterization of four cloned HMI-C121, HMI-C131, HMI-C143, HMI-C144 cultures of axenic E. histolytica (HMI) revealed existence of three bands of hexokinase (HK). The additional third band of HK was located close to the place of application of lysate and had rf ranging from 0.11-0.14. The data indicated that parent axenic E. histolytica (HMI) consisted of several populations and each population expressed different isoenzyme pattern without an association of amoebic cultures with any bacterial species.

Isoenzyme analyses of Malaysian Schistosoma, S. mekongi and S. japonicum by isoelectric focusing in polyacrylamide gel.

Isoenzyme patterns of adult Malaysian Schistosoma, S. mekongi and S. japonicum strains were analysed by isoelectric focusing (IEF) in polyacrylamide gel. Enzyme patterns obtained from Malaysian Schistosoma homogenates differed from those of S. mekongi and S. japonicum strains. Malaysian Schistosoma was found to differ from S. japonicum by 8 enzymes, namely phosphoglucomutase, phosphoglucoisomerase, malate dehydrogenase, acid phosphatase, hydroxy-butyrate dehydrogenase, hexokinase and alkaline phosphatase, and from S. mekongi by phosphoglucomutase, malate dehydrogenase, aldolase and alkaline phosphatase. These results and the distinct biology of the parasite suggest that Malaysian Schistosoma is a new species in the S. japonicum complex.