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At least 919 records · Page 51Linked to original sources
PubMed1991

A serine esterase released by human alveolar macrophages is closely related to liver microsomal carboxylesterases.

We identified a 60-kDa diisopropylfluorophosphate-(DFP) reactive protein in human bronchoalveolar lavage fluid, at a yield of 50-100 pmol/lavage. The protein is associated with the cell-free lavage fluid sediment, which consists mainly of surfactant. [3H]DFP labeling is inhibited by heating to 56 degrees C, 2 mM phenylmethylsulfonylfluoride and 1 mM bis(4-nitrophenyl)-phosphate. An identical 60-kDa [3H]DFP-reactive protein is present in the insoluble fraction of alveolar macrophage-conditioned culture medium and in total membrane preparations of alveolar macrophages. The [3H]DFP-labeled protein was purified approximately 30-fold from lavage fluid sediment by size-exclusion (Sephacryl S-200) and ion-exchange (Mono-Q) chromatography. Cyanogen bromide treatment of the partially purified protein produced a major labeled peptide of 14 kDa with an NH2-terminal sequence 90% identical to a region of form 1 rabbit liver microsomal carboxylesterase. Esterase activity in unlabeled starting material, detected using p-nitrophenyl valerate as substrate, copurified with the [3H]DFP-labeled enzyme. Degenerate oligonucleotide primers were designed based on the partial amino acid sequence and on a highly conserved region of known liver carboxylesterase sequences. Polymerase chain reaction using these primers and reverse-transcribed human alveolar macrophage mRNA yielded a 354-base pair product which was then used to screen a human alveolar macrophage cDNA library. A complete esterase sequence was obtained from two incomplete, overlapping clones, and is virtually identical to human liver carboxylesterase partial sequences. Northern blot analysis demonstrated a single approximately 1.7-kilobase transcript in human monocytes and alveolar macrophages, with much higher levels in the latter. These data indicate that human alveolar macrophages both contain and release a serine esterase that is apparently identical to liver microsomal carboxylesterase. Its enzymatic profile suggests it is a major component of alveolar macrophage-nonspecific esterase activity. We hypothesize that it acts as a detoxication enzyme in the lung.

Adult↗
PubMed1975

Lipase and unspecific esterase activity in the fat body of Aedes aegypti L.

In the fat body of Aedes aegypti a very high unspecific esterase activity and a low lipolytic activity was found. The electrophoretic isozyme patterns of the unspecific esterases show only few changes in the different physiological stages. The activity of the unspecific esterases as well as of the lipase is especially high in young sugar fed and in blood fed mosquitoes which points to special energy requirements in these stages. The role of the unspecific esterases is discussed.

Aedes↗
PubMed1991

[Esterase activity of neutrophils and monocytes in patients with stenocardia and myocardial infarction].

Neutrophils and monocytes of coronary patients and healthy subjects were investigated for activity of alpha-naphthylacetate esterase, naphthol--AS--D+chloroacetate esterase, alpha-naphthylbutyrate esterase. This activity varied from healthy to coronary subjects, among anginal and MI sufferers, etc. The fact made the authors to suggest comprehensive evaluation of monocyte and neutrophil esterase activity as a diagnostic and prognostic indicator.

Adult↗
PubMed1985

Industrial exposure to organophosphorus compounds. Studies of a group of workers with a decrease in esterase-staining monocytes.

When an automated counting instrument using an esterase stain was employed, decreased monocyte counts were observed in a group of process workers exposed to organophosphate esters. Their monocyte counts were not found to be depressed with manual counting or with an automated counter using another staining method. The apparent depression was transient. In these workers and a comparison group, theoretical adverse consequences of decreased monocyte esterase and also possible changes in other esterases were explored. No anergy was seen with mumps or staphylococcal phage lysate hypersensitivity skin tests. Histology of the mumps reaction was similar in both groups. The depressed monocyte counts were significantly associated with a mild reduction in erythrocyte cell acetylcholinesterase, but no reduction was seen in plasma pseudocholinesterase or lymphocyte neurotoxic esterase.

Adult↗
PubMed1989

Flow-cytometric determination of intracellular pH, esterase activity and cell volume in human leukemic cell lines following in vitro incubation with cytostatic drugs.

A recently developed flow cytometric assay method using patient tumor cells allows the determination not only of their sensitivity to cytostatic drugs but also of biochemical and biophysical parameters after treatment, such as esterase concentration and intracellular pH of the living cells. DNA-content of the dead cells and cell volume of living and dead cells. The T-cell lines CEM, Molt4, Jurkat, the B-cell lines RPMI1788, Daudi, Raji and the promyelocytic line HL60 were incubated with: cytosine arabinoside (ara-C), L-asparaginase, daunorubicin, vincristine and prednisone for 48 h. Living cells then stained with esterase and pH-dye 1,4-diacetoxy-2,3-dicyanobenzene (ADB) and dead cells with DNA-dye propidium-iodide (PI). The esterase concentration, an index of metabolic activity, decreased in the T-cell lines under the influence of ara-C, daunorubicin and vincristine, whereas in the B-cell lines smaller changes in esterase concentration were observed (P less than 0.001). A decrease in intracellular pH was seen in the ara-C and daunorubicin-incubated cells Molt4, CEM and HL60, whereas in the B-cell lines no significant change in intracellular pH was found. In all lines except Jurkat the cell volume of the surviving cells increased under the influence of certain drugs (primarily ara-C and daunorubicin); B-cell lines showed a greater swelling than T-cell lines (P = 0.001).

Antineoplastic Agents↗
PubMed1989

Serum aspirin-esterase activity in epileptic patients receiving treatment with phenobarbital, phenytoin, carbamazepine and valproic acid.

Serum aspirin-esterase activity was studied in a group of epileptic patients under treatment with phenobarbital, phenytoin, carbamazepine and valproic acid, and a group of healthy controls. Serum rates of hydrolytic activity as well as serum esterase activity were found to be higher in epileptics (p less than 0.001) than in controls. The findings suggest that the above-mentioned antiepileptic drugs may induce plasma esterase activity, thus leading to increases in serum hydrolytic activity in epileptic subjects. On the other hand, no sex or albumin-related differences were observed in serum aspirin-esterase activity in the groups investigated.

Adult↗
PubMed1989

[The esterase activity of the peripheral blood in patients with foot mycoses].

Nonspecific esterase activities were measured in the peripheral blood phagocytes (neutrophils and monocytes) of 37 patients with mycoses of the soles. The measurements have revealed lowered potentials of alpha-naphthylacetate esterase, naphthol-AS-acetate esterase, and naphthol-AS-D-chloracetate esterase, which appears to be due to depressed leucocyte phagocytic activity. Diucifon therapy corrected this metabolic imbalance.

Adjuvants, Immunologic↗
PubMedDate not supplied

[The esterase activity of a pigmented bacterial group belonging to the Pseudomonas genus].

Bacteria belonging to the Pseudomonas genus and isolated from zonal soils in different geographical zones of the USSR as well as from the rhizosphere of cultivated and wild plants were tested for their esterase activity. The studied collection of cultures included 205 strains of different pigmented Pseudomonas species which, according to the conventional taxonomy, were assigned to the so-called "Pseudomonas fluorescens complex". As was shown in this study, many Pseudomonas species are potential producers of nonspecific esterases. P. maltophilia and P. geniculata synthesizing pyomelanin have the highest activity of esterase. The activity of esterase correlates with the formation of a melanin-like pigment in Pseudomonas cultures. It also correlates with the species to which a culture belongs, which makes it possible to use this property as an additional criterion for the identification of Pseudomonas species.

Esterases↗
PubMed1989

[Study on inhibiting effect of 14 insecticides on esterase of Culex tritaeniorhynchus from five geographic populations].

Isoelectrofocusing technique was used to study the inhibiting effect of 14 insecticides on esterase isozymes of Culex tritaeniorhynchus from natural populations in Fuzhou, Shanghai, Qingdao, Dalian and Beijing areas. Among 14 insecticides, organophosphates were good inhibitors to all esterase isozymes, but Allethrin, Propoxur, DDT, Dieldrin had no or almost no inhibiting effect on esterase. 26 esterase isozyme bands of Culex tritaeniorhynchus were revealed by isoelectrofocusing.

Animals↗
PubMed1986

Herpesvirus infection prevents activation of cytoplasmic cholesteryl esterase in arterial smooth muscle cells.

Herpesvirus infection has been shown to alter the cholesteryl ester cycle in avian arterial smooth muscle cells, resulting in cytoplasmic cholesteryl ester accumulation (Hajjar, D. P., Falcone, D. J., Fabricant, C. G., and Fabricant, J. (1985) J. Biol. Chem. 260, 6124-6128). In this study, we attempted to define some of the regulatory mechanisms associated with the control of cytoplasmic cholesteryl esterase in Marek's disease herpesvirus (MDV)-infected cells. We found that cholesteryl esterase activity in MDV-infected cells could not be activated by dibutyryl cyclic AMP, dibutyryl cyclic AMP added together with protein kinase, or agonists of adenylate cyclase. Activation of cytoplasmic cholesteryl esterase activity occurred in uninfected cells and in cells infected with a control virus, turkey herpesvirus. Furthermore, the rate of cholesterol efflux from arterial smooth muscle cells challenged with dibutyryl cyclic AMP was unchanged in MDV-infected cells as compared to uninfected or turkey herpesvirus-infected cells in which efflux was increased. We propose that the reduced cytoplasmic cholesteryl esterase activity in lipid-laden, herpesvirus-infected cells is due partly to its inability to be activated by the cyclic AMP-protein kinase mechanism. This may contribute to the pathologic changes seen in MDV-infected arterial cells, including accumulation of intracellular cholesteryl esters.

Animals↗
PubMed1988

Complete covalent structure of 60-kDa esterase isolated from 2,3,7,8-tetrachlorodibenzo-p-dioxin-induced rabbit liver microsomes.

The 60-kDa esterase was isolated from liver microsomes of 2,3,7,8-tetrachlorodibenzo-p-dioxin-induced rabbits and its complete amino acid sequence determined. Automated sequence analysis of intact protein, as well as characterization of the peptides obtained from enzymatic and chemical cleavages, led to the elucidation of the primary structure. The protein is a single polypeptide consisting of 539 residues and molecular weight 59,478. The active site serine is 195, and another diisopropylphospho binding site is at histidyl 441. Carbohydrate chains are attached at aspariginyl residues 61 and 363. Although 2,3,7,8-tetrachlorodibenzo-p-dioxin treatment induces this esterase severalfold, the amino acid sequence of the induced enzyme is identical to that of the enzyme isolated from liver microsomes of untreated rabbits. The sequence of the microsomal esterase is 30% identical with the sequences of human serum cholinesterase and the acetylcholinesterase from Torpedo californica. There is also a close homology between the 60-kDa esterase and the COOH-terminal domain of bovine thyroglobulin.

Acetylcholinesterase↗
PubMedDate not supplied

Zymographic characteristics of soluble and bound esterases in nervous tissues and brain tumors.

The Authors describe zymographic characteristics of non specific esterases in human and rat brain and in tumors of the nervous system. Bound and soluble esterases were evidenced using substrate and inhibitor systems in association with detergent extraction. In normal nervous tissues the results confirmed previous observations on the identity of the gray and white matter esterases, except for minor quantitative differences. In brain tumors some peculiar pattern was particularly useful for biological interpretation of tissue differentiation and cell metabolism. The Authors show that the use of Triton X-100 extraction associated with suitable effectors allows a more correct classification of non specific esterases.

Animals↗
PubMedDate not supplied

[Effect of precipitating antibodies to pancreatic kallikrein on arginine esterase contact activation in human and rabbit blood].

Effect of precipitating antibodies against pig pancreatic kallikrein on the BAEE-esterase activity was studied in human blood plasma and in rabbit blood serum, activated by kaolin. An inhibitory effect of the antibodies on the increased BAEE-esterase activity was observed within the first minute of incubation after treatment with kaolin. The inhibition of the BAEE-esterase activity constituted 65.1% in human blood plasma and 40.9% in rabbit serum. Possible mechanism is discussed on the inhibition of contact activation of arginine esterase in human and rabbit blood by antibodies against pancreatic kallikrein.

Animals↗
PubMed1972

Nongenetic determinants of human serum esterases.

A panel of 1151 unselected individuals was screened by starch gel electrophoresis for serum esterase variants. Two types of variants were observed which were shown by family studies not to be genetically determined. No consistent disease process was correlated with the occurrence of these variants. Suggestive evidence has been obtained to support the hypothesis that these variant proteins were produced by the action of exogenous neuraminidase on the individuals' normal C, esterases. A third type of variant enzyme was observed in 1 patient. This enzyme was shown to be a substantially larger molecule than the C, esterase and it is suggested that this protein may be a polymer of the C, esterase.

Adult↗
PubMed1978

Histochemical studies on genetical control of hormonal enzyme inducibility in the mouse. I. Non-specific esterase activity and regional histology of the epididymis.

As a base line for future cell genetical studies the authors record the distribution of non-specific esterase reaction in the various histologically distinguishable cell types of the mouse epididymis. The findings are correlated with previous descriptions of the lobar structure of the organ. Assuming the sequence of lobes of the head to be as implied in these classical descriptions, the esterase activity of the epithelial cells gradates between strong to weak several times along the length of the epididymal duct. The relationship of the lobes to each other, as seen in transverse sections, is described. Methodological studies using different fixatives indicate that apparent similarity of esterase reaction at different sites may camouflage an underlying difference in the nature of the esterases at these sites.

Animals↗
PubMed1980

Distributive patterns of 5'-nucleotidase and simple esterase in the diencephalon and mesencephalon of the garden lizard (Calotes versicolor).

Different enzymatic patterns of 5'-nucleotidase and simple esterase have been observed in the diencephalon and mesencephalon of the garden lizard, Calotes versicolor. Most of the brain centers have shown the enzyme activities, ranging from negligible through very strong, in the neurons and neuropil. However, two brain centers, the DLH and NM, were found negative to 5'-nucleotidase. On the other hand, no brain center showed negative picture in the preparations of simple esterase. In general, it has been observed that the enzyme activity dominates in the neurons than the neuropil both for 5'-nucleotidase and simple esterase. The major fiber tracts have shown mild reaction product of 5'-nucleotidase except a solitary fiber bundle, the lateral forebrain bundle, which demonstrated, invariably, strong to very strong enzyme activity; the commissura colliculi superioris was, however, negative for the enzyme activity. On contrary, most of the fiber tracts showed strong to very strong activity of simple esterase. The significance of the distributive patterns of the two enzymes in relation to various brain centers and fiber tracts has been discussed.

5'-Nucleotidase↗
PubMed1984

Serum esterase activity during the surgical therapy of bronchogenic carcinoma.

Serum esterase activity was estimated in 148 patients with bronchogenic carcinoma and in 19 patients with pulmonary tuberculosis before operation, 1 week and 3 weeks after operation. We failed to prove significant differences between the patients with malignant and nonmalignant lung diseases. We failed also to prove significant differences between the mean esterase activity findings regarding to the extent of surgery. They were identical even of the performed thoracotomy was radical, palliative or explorative. The course of changes in esterase activity findings is quite individual. From the esterase activity we cannot conclude, if the tumor tissue was completely removed or not.

Carcinoma, Bronchogenic↗
PubMed1982

[Histochemical and biochemical investigations of the hippocampus and neocortex of the wistar rat. III. Electron-microscopic investigations on the localization of non-specific esterases in the hippocampus (author's transl)].

This report describes the ultrastructural localization of the non-specific esterases in the pyramidal cells of the CA3-region of rat hippocampus. The use of specific inhibitors allowed the differentiation between aryl-, carboxyl- and acetylesterases. The thiolacetic acid reaction at pH = 5.2 and 7.0 proved to be a favourable method for the conditions of the hippocampus. Liver tissue served for control purposes. In the pyramidal cells carboxylesterase could be demonstrated on membranes and cisternes of the endoplasmic reticulum on polysomes and in the nuclear envelope. Arylesterase was localized in numerous synaptic vesicles and in the myeline sheath of axons. In lysosomes and in mitochondria an esterase activity was demonstrable, which behaved like an acetylesterase. In the hippocampus carboxylesterase could be shown only at pH = 7.0, whereas in liver this enzyme also give a clear reaction at pH = 5.2. Aryl- and acetylesterase reacted at both pH-ranges in the hippocampus. Biochemical investigations showed that the tissue pretreatment, which is necessary for the ultrahistochemical demonstration of nonspecific esterases considerable decreased the enzyme activity. Formaldehyde and glutaraldehyde have thereby a different action on the several esterase types.

Animals↗