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J Sandula

Publications and source records attributed to J Sandula.

At least 37 records · Page 2Linked to original sources
PubMed1992

Enhancement of hematopoietic recovery in gamma-irradiated mice by the joint use of diclofenac, an inhibitor of prostaglandin production, and glucan, a macrophage activator.

The effects of diclofenac (inhibitor of prostaglandin production) and carboxymethylglucan (immunomodulator and an agent stimulating hematopoiesis), when given to mice 1 day before gamma-irradiation, were studied. Both of the agents were administered either alone or in combination. The investigations included the assessment of post-irradiation hematopoietic recovery in terms of bone marrow and spleen cellularity and endogenous spleen colony formation, as well as the determination of the survival of lethally irradiated mice. The results demonstrated at least additive radioprotective effects when mice were given diclofenac and carboxymethylglucan in combination. Experimental evidence provided by the increased 125iodo-deoxyuridine incorporation into the spleen and elevated hydroxyurea kill of endogenous spleen colony-forming units indicated that the beneficial action of the combined treatment could be a consequence of increased cell proliferation in the hematopoietic tissue. It is likely that the inhibition of prostaglandin production (diclofenac action) and the concomitant increased release of growth factors (glucan action) shift the regulatory balance towards the predominance of positive hematopoietic control.

Animals↗
PubMed1991

Treatment of leukemia L1210 and P388 by arabinosylcytosine-polysaccharide conjugates.

Conjugates of 1-beta-D-arabinofuranosylcytosine (araC) with two polysaccharides such as polygalacturonic acid (PGA) and carboxymethylated yeast beta-D-glucan (CMG) were tested for their antileukemic activity in vitro on a L1210 cell line in suspension culture, in soft agar assay and in vivo on L1210, L1210/araC- and P388-leukemia-bearing mice. Both conjugates showed high activity in vitro in soft agar assay, compared with araC. Single administration of PGA-araC or CMG-araC increased the survival time 1.5 x or 1.7 x, respectively, compared with araC in vivo in L1210-leukemia-bearing mice. The conjugates were not active against araC-resistant leukemia line L1210/araC. The marked effect of both PGA-araC and CMG-araC against leukemia L1210 and P388 is probably due to the prolonged release of free araC from conjugates caused by hydrolysis.

Animals↗
PubMed1991

Hemopoiesis stimulating and radioprotective effects of carboxymethylglucan.

Carboxymethylglucan, a novel soluble derivative of beta-1,3-glucan, was found to enhance hemopoietic recovery in sublethally gamma-irradiated mice and to increase survival in lethally irradiated animals when given 24 hours prior to irradiation. Postirradiation treatment with carboxymethylglucan also induced favourable effects in terms of survival when used in combination with preirradiation cystamine administration.

Animals↗
PubMed1991

Lipids in yeast cell wall glucans.

Lipids isolated from glucans of Saccharomyces cerevisiae were analysed by thin-layer chromatography, infrared spectroscopy and gas-liquid chromatography. Localization of glucan lipid in the polysaccharide net was observed by light and electron microscopy. Despite using Manner's method for glucan preparation, the residue of acidic lipid occupied a central position in the treated cells. Analysis showed the presence of free fatty acids in which a relatively high content of vaccenic acid was detected.

Cell Wall↗
PubMed1991

[Modulatory effect of glucans on the function of murine macrophages, NK-cells and lymphocytes].

The particulate glucan (G1), soluble glucan preparations (G2 to G5, and G7) isolated from Saccharomyces cerevisiae, and glucomanan prepared from culture fluid after cultivation of Candida utilis (G6) were tested for their immunomodulatory activity in vivo and in vitro. In tests in vivo three soluble glucans (G3, G4, and G7) injected s.c. to mice in the dose of 10 mg/kg increased the cytotoxic activity of peritoneal macrophages. The influence of glucans on natural killer cells was without significance. The lymphoproliferative reaction of spleen cells to polyclonal mitogens was inhibited by all the preparations used with the exception of soluble glucan G2. The mitogenic effect of the preparations, co-stimulatory tests and direct cytotoxicity to cells of cell lines used in cytotoxicity assays were assessed in vitro. The transformation index of glucans in the study was increased according to the glucan and dose tested. Inhibition of the lymphoproliferative reaction measured by the co-stimulatory test for optimal concentration of Concanavalin A occurred in a wide range of doses for the preparations G1 to G6. The preparation G7 increased the incorporation of 3HTdR under the same conditions. The use of a suboptimal concentration of Concanavalin A revealed co-stimulatory activity of all the preparations tested. Assessment of the cytotoxic activity of peritoneal macrophages and of the activity of natural killer cells induced in vitro was complicated by the direct cytotoxicity of particulate glucan and soluble glucan G5 (carboxymethylglucan) for target cells (YAC 1, and YAC 1 and K 562 resp.).

Adjuvants, Immunologic↗
PubMed1990

Immunochemical and structural analysis of the cell wall mannan as the basis of the taxonomic reidentification of a yeast strain.

The immunochemical properties and structural features of D-mannans from two Candida parapsilosis strains were studied. Weak cross-reactivity of D-mannans with antisera produced to C. parapsilosis strains was observed, as well as significant differences in the mannans structures were found by means of methylation analysis, acetolysis and 1H-NMR spectroscopy. In view of the discrepancies found, new taxonomic identification of one strain was carried out. On the basis of assimilation of potassium nitrate and formation of hat-shaped spores as well as other differences found by investigation of physiological characteristics, one strain of C. parapsilosis was reidentified as Hansenula anomala. This work demonstrates that immunochemical and structural investigations of cell-wall polysaccharide components can serve as a basis for taxonomic identification of yeast strains.

Candida↗
PubMed1990

Preparation, properties and antileukemic activity of arabinosylcytosine polysaccharide conjugates.

1. Conjugates of 1-beta-D-arabinofuranosylcytosine (araC) with polysaccharides containing carboxyl groups, such as polygalacturonic acid (PGA) and carboxymethylated yeast beta-D-glucan (CMG) were prepared. 2. Activation of the polysaccharidic carboxyl group by isobutylchloroformiate and formation of a peptide bond via 4-NH2 group of araC was used for a coupling reaction. 3. Elementary analysis, u.v. and i.r. spectra confirmed the structures of the conjugates. 4. The conjugates were most stable against the hydrolysis under the mild acid conditions. 5. It was also shown that under the physiological conditions trypsin catalyze the conjugate hydrolysis and the catalytic effect is higher than that of chymotrypsine. 6. It is suggested that trypsin or trypsin-like proteases could participate in the hydrolysis of the conjugates in vivo. PGA-araC and CMG-araC showed 1.5- or 2.5-times higher antileukemic activity than both free araC or polysaccharides.

Animals↗
PubMed1988

Novel structure of the cellular mannan of the pathogenic yeast Candida krusei.

On the basis of methylation analysis, 13C- and 1H-n.m.r. spectroscopic data, and the results of immunological methods, a new structure for the cell-wall alpha-D-mannan of the pathogenic yeast Candida krusei is proposed. In contrast to the alpha-D-mannans of other pathogenic yeasts of the Candida species, which have (1----6)-linked main chains and many (1----2)- and/or (1----3)-linked side chains, the C. krusei mannan is lightly branched and contains (1----2) and (1----6) linkages in the ratio 3:1.

Acetylation↗
PubMed1986

Modulatory effect of glucans on the functional and biochemical activities of guinea-pig macrophages.

The particulate and soluble glucan preparations isolated from Saccharomyces cerevisiae and Candida albicans affected various activities of guinea-pig macrophages. The stimulation of INT reduction and superoxide production were observed in the presence of all insoluble and some soluble glucans in vitro, but most of the preparations under study had an inhibitory effect on phagocytic activity. On the other hand, the stimulation of both metabolic and functional activities was obtained in vivo. Macrophages from guinea-pigs treated with glucans exerted an increased ability to reduce INT and to produce superoxide. Their candidacidal capacity was rapidly elevated, and peritoneal macrophages had raised phagocytic activity as well. A more pronounced stimulatory effect was observed in the presence of insoluble rather than soluble glucans, and this was more expressive in vitro than in vivo.

Animals↗