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J Bata

Publications and source records attributed to J Bata.

At least 19 recordsLinked to original sources
PubMed2001

Encephalitozoon cuniculi (Microspora): characterization of a phospholipid metabolic pathway potentially linked to therapeutics.

Phospholipid metabolism of the microsporidian Encephalitozoon cuniculi, an obligate intracellular parasite, has been investigated. Labeled precursor incorporation experiments have shown that phosphatidylserine decarboxylase and phosphatidylethanolamine N-methyltransferase are more active in cells infected by E. cuniculi than in uninfected cells. In contrast, no difference was observed in the activity of Kennedy pathway's enzymes, the mammalian pathway. This suggests the occurrence in microsporidia of a bacteria- and fungi-typical pathway for phospholipid synthesis, which is supported by the identification of two genes implicated in this pathway, the cds gene encoding the key enzyme CDP-diacylglycerol synthase (E.C. 2.7.7.41) and the pss gene for CDP-alcohol phosphatidyltransferase. The pss gene could encode phosphatidylserine synthase (E.C. 2.7.8.8.), which catalyses the de novo synthesis of phosphatidylserine in bacteria and fungi. The complete CDP-diacylglycerol synthase messenger has been isolated and shows very short 5' and 3' untranslated regions. This is strong evidence for the functionality of a metabolic pathway which could be a potential target against microsporidia which infect humans.

Amino Acid Sequence↗
PubMed2001

Lipids of three microsporidian species and multivariate analysis of the host-parasite relationship.

Sporal lipids of 3 microsporidia, Encephalitozoon cuniculi from mammals and Glugea atherinae and Spraguea lophii from fishes, were investigated. High phospholipid levels were found (54.8-64.5% of total lipids), which is in agreement with the presence of highly developed internal membranes in microsporidian spores. Sphingomyelin was not detected in G. atherinae. Triglycerides (less than 10% of total lipids), cholesterol, and free fatty acids were identified in all species. Analysis of fatty acids from the phospholipid fraction revealed the predominance of docosahexaenoic acid (30-40% of total phospholipid fatty acids) in G. atherinae and S. lophii and oleic acid (25.8% of total phospholipid fatty acids) in E. cuniculi. The 3 microsporidia possessed a significant amount of branched-chain fatty acids (iso and anteiso forms) not found in the hosts, supporting the existence of some parasite-specific metabolic steps for these fatty acids. On the basis of phospholipid fatty acid profiles, host-parasite relationships were investigated through correspondence factorial analysis. It shows 3 distinct clusters with the first corresponding to fishes, the second to fish parasites, and the third to E. cuniculi and its host cell. These data suggest that the mammal microsporidia developing within parasitophorous vacuoles are more dependent on host cells than the fish microsporidia that induce cystlike structures.

Animals↗
PubMed1996

Glycoside and polysaccharide hydrolase activity of the rumen anaerobic fungus Caecomyces communis (Sphaeromonas communis SENSU ORPIN) at early and final stages of the developmental cycle.

The rumen anaerobic fungus Caecomyces communis was grown in a fermentor in Lowe medium. We studied four polysaccharide hydrolases and three glycoside hydrolases at early and final stages. We found a difference in cell association for these enzymes depending on the developmental stage. The endocellulase and beta-D-fucosidase were early synthesized, and their activities decreased at the end of the developmental cycle. On the contrary, the beta-D-glucosidase, beta-D-xylosidase and xylanase activities increased during the cycle. The avicelase and the CM-cellulase activities linked with thalli increased, whereas the extracellular activities of these enzymes decreased.

Animals↗
PubMed1996

Polysaccharide hydrolase production by the rumen fungus Caecomyces communis.

The anaerobic fungus Caecomyces communis was grown in a fermentor in either a discontinuous cultivation system or in a culture system with daily withdrawal and addition of fresh medium. Lowe and Orpin media were tested. The Lowe medium was best for the stimulation of enzyme production, the Orpin medium, for the stimulation of fungal growth and enzyme release. Xylanase activity was predominant among the polysaccharide hydrolases. Most of the enzymes studied were associated with cells except when the culture medium contained glucose or Ray grass hay. Enzymatic activities were constitutive, but their level was regulated by a carbon source. Cellulase production in both the cellular and extracellular fractions and the extracellular xylanase activity were stimulated by the presence of glucose. Cell-associated xylanase activity, however, was stimulated by glucose plus cellobiose. The presence of glucose enhanced enzyme release.

Animals↗
PubMed1994

On small genomes in eukaryotic organisms: molecular karyotypes of two microsporidian species (Protozoa) parasites of vertebrates.

Pulsed field gel electrophoresis (PFGE) was used to separate chromosome-sized DNA from two species of microsporidia of fishes. The molecular karyotype of Glugea atherinae exhibits 16 DNA bands from 420 to 2,700 kb, and that of Spraguea lophii 12 bands from 230 to 980 kb. Until now they represent respectively the largest and the smallest genomes visualized for microsporidia: 19.5 Mb for G. atherinae and 6.2 Mb for S. lophii (the smallest nuclear genome in eukaryotic organism). We have analysed separately five strains of G. atherinae (individual cysts), with this technique. The electrophoretic spectra are the same for these strains, except for the absence of the 2,380-kb band in one case. Therefore, the karyotype seems to be rather well conserved for this species.

Animals↗
PubMed1984

Distribution and characterization of cAMP-dependent protein kinase isoenzymes in bovine adrenal cells.

Subcellular localization and characterization of cAMP-kinase isoenzymes in fasciculata reticularis bovine adrenal cells has been investigated. Different subcellular fractions were purified on a Percoll gradient and characterized by marker enzymes. cAMP-kinase was located principally in cytosol and microsomes. In the low-speed particulate fractions cAMP-kinase was found associated mainly with plasma membrane but not with mitochondria. Characterization of isoenzyme patterns in subcellular fractions by conventional DEAE-cellulose chromatography and by anion-exchange HPLC gives essentially the same results. Isoenzyme I appears to be the main enzyme in cytosol whereas isoenzyme II predominates in solubilized microsome and plasma membrane enriched fraction. Photoaffinity labelling of chromatographic fractions demonstrated that HPLC separates both cAMP binding subunits. Photoaffinity labelling of the different subcellular fraction by 8-azido-[32P]cAMP confirmed the data obtained by anion-exchange chromatography. However, in microsomes this method revealed the presence of both isoenzymes and the preferential solubilization of isoenzyme II by Triton X-100. In summary, our results indicate a subcellular compartmentalization of cAMP-kinase in bovine adrenal cells with a preferential localization of isoenzyme I in cytosol and of isoenzyme II in membrane. However, the relation between the distribution and the role of each isoenzyme has so far not been documented.

Adrenal Glands↗
PubMed1981

[Intracellular cyclic AMP in vesicular stomatitis or Sendaï virus infected cells (author's transl)].

In KB cells, MRC5 and adult skin fibroblasts infected by low doses of Sendaï virus, intracellular cyclic AMP levels rose and fell in the first hours following infection, then remained lower than basal level during at least 2 days in KB cells and adult skin fibroblasts. When compared to other viruses or cAMP inducers previously described, this effect appeared specific of Sendaï virus. Mechanisms and roles of cAMP variations are discussed. VSV-infected KB cells showed slightly decreased cAMP levels during the first hours following infection.

Cells, Cultured↗
PubMed1981

Interaction between alpha 1 antitrypsin and lymphocyte surface proteases: immunoregulatory effects.

Alpha 1 antitrypsin (alpha 1-AT) is the major plasma protease inhibitor. Radioiodinated alpha 1-AT binds to human lymphocytes. The binding is fast and reversible, and the cells can be saturated with a maximum of approximately 1.2 x 10(6) molecules of alpha 1-AT per lymphocyte. The receptor for alpha 1-AT is a surface-associated protease. Addition of alpha 1-AT completely inhibits cell surface proteolytic activity. Furthermore alpha 1-AT decreases 3H-thymidine incorporation into lymphocytes stimulated by B or T cell mitogens or by allogeneic cells. Since alpha 1-AT was shown to be produced by activated monocytes and to bind to lymphocytes, it is likely to represent a mediator of monocyte-lymphocyte interactions.

Animals↗
PubMed1978

[alpha-Amylase activity in lysosomes of Aspergillus oryzae (author's transl)].

The alpha-amylase of mycelial cells of Aspergillus oryzae exists in a particular form in 8000 g pellet. The lysosomal localization of acid phosphatase is confirmed by electron microscopy. The purification of lysosomes by discontinuous gradient of sucrose in D2O shows that alpha-amylase activity is bound to these particles.

Acid Phosphatase↗
PubMed1978

[The humoral immune response in recent pulmonary tuberculosis (author's transl)].

The average serum concentration of immunoglobulins, alpha-1-antitrypsin, haptoglobin and alpha-2-macroglobulin, calculated in 45 adults with pulmonary tuberculosis increased in a variable way for each of the six parameters studied. Tuberculosis does not induce new correlations between the parameters but modifies the intensity of existing links.

Adult↗
PubMed1977

[Optimal conditions of alpha-amylase production by Aspergillus oryzae in liquid media].

The alpha-amylase secretion in a mineral culture medium containing starch and glucose follow the lysis of mycelium. This lysis seems to result from the hydrolysing action of dextranase and levulanase on cell wall. Cell lysis and amylase secretion are greatly enhanced by pH elevation of culture medium (optimal pH 8,8). In such conditions of production the amylase is not stable but can be stabilized by addition of starch. A method is described using pH and starch content modifications, which allows to obtain an amylase production three times greater than in standard culture medium.

Amylases↗
PubMed1977

[Study of various serum proteins in lung cancer. Immunoglobulins A, G, M, haptoglobin, alpha-1-antitrypsin, alpha-2-macroglobulin].

A statistical study of the plasma concentration of immunoglobulin, alpha-1-antitrypsin, haptoglobin, and alpha-2-macroglobulin in 153 patients with primary carcinoma of the lung showed a strong increase in alpha-1-antitrypsin, haptoglobin and A and C immunoglobulins, whilst alpha-2-macroglobulin increases very moderately, and IgM does not vary. The relationships between variables are also modified, thus there appears a correlation between IgA and IgG to the detriment of the IgG/IgM relationship. Furthermore the coefficient of the correlation IgG/alpha-2-macroblobulin is lower in cancer patients.

Female↗
PubMed1969

[Farmer's lung].

Explore the source record for details and available documents.

Adult↗
PubMedDate not supplied

Modification of lymphocyte DNA synthesis by alpha 1-antitrypsin.

Purified human alpha 1-antitrypsin (alpha 1-AT) was shown to inhibit 3H-thymidine incorporation into mouse or human lymphocytes stimulated by various mitogens or by allogeneic cells. In the mouse, both B- and T-cell responses were affected. In the human, proliferative responses of peripheral blood lymphocytes, thymocytes and T-enriched tonsillar lymphocytes to phytohaemagglutinin were inhibited as well as that of tonsillar lymphocytes to Salmonella typhi-murium lipopolysaccharide. Spontaneous 3H-thymidine incorporation was moderately and inconstantly decreased, without evidence of altered cell viability. The inhibitory effect of alpha 1-AT appears to be related to its protease inhibitory capacity. These data bring further evidence for the role of proteolytic enzymes in the early events of lymphocyte activation, and support the hypothesis that serum inhibitors of proteases may contribute to the modulation of the immune response.

Animals↗