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Biomedical subjects

A G Bulychev

Publications and source records attributed to A G Bulychev.

At least 19 recordsLinked to original sources

[The influence of tumor growth on natural cytotoxicity and activity of some lysosomal enzymes of human effector cells and the C3HA mouse splenocytes].

In the course of malignant growth processes in patients with lung cancer, a decrease of natural cytotoxic activity of peripheral blood lymphocytes was observed. This process was accompanied by changes of activities of two lysosomal enzymes, arylsulfatase and acid phosphatase, suggesting participation of these enzymes in manifestation of effector functions of lymphocytes in cancer patients. The level of activity of granular enzyme, beta-glucuronidase, remained unchanged at all stages of disease. A study of natural killer activity of C3HA mice splenocytes after inoculation of transplantable hepatoma 22-a cells revealed a relative stability of the level of their cytotoxicity, and of the activities of lysosomal enzymes--arylsulfatase, acid phosphatase, alpha-mannosidase, acid lipase, N-acetyl-beta-D-glucosidase, and beta-galactosidase, beginning from the 3rd day after hepatoma implantation.

Acid Phosphatase↗

[Effect of immunosuppressors cyclophosphane and 5-fluorouracil on natural cytotoxicity and activity of lysosomal enzymes of splenocytes in C3HA mice].

Effects of two immunosuppressors, cyclophosphane abd 5-fluorouracyl, used in clinical practice for treatment of oncological diseases, were assessed in respect to cytotoxicity and activity of several lysosomal enzymes located in splenocyte granules of C3HA mice. 48 h after a single intraperitoneal injection, both preparations produced a marked decrease in their cytotoxic activity, which was accompanied by a pronounced splenopathy. Both preparations were shown to decrease activity of arylsulfatase. Administration of cyclophosphane brought about the rise of activity of acid lipase as compared to control. Activities of acid phosphatase, alpha-mannosidase, beta-galactosidase, and N-acetyl-beta-D-glucosidase did not change after administration of the used immunosuppressors. It may be suggested that only arylsulfatase and acid lipase are involved in performance and(or) manifestation of the natural killer activity in splenocytes of the C3HA mice after their administration with cyclophosphane or 5-fluorouracyl.

Animals↗

[Effect of polyamine synthesis inhibitors separately and in combination with epidermal growth factor on fusion of lysosomes with phagosomes and F-actin level in mouse peritoneal macrophages].

Effects of polyamine (PA) synthesis inhibitors--alpha-difluoromethylornithinchloride (DFMO) and alpha-methylornithinchloride (MO)--separately or in combination with the epidermal growth factor (EGF)--on lysosome-phagosome fusion (P-LF) and F-actin content in murine peritoneal macrophages were studied using fluorescent dye Acridine orange for lysosome labelling, FITC-phalloidin for F-actin, and yeast cells as a target. DFMO and MO significantly inhibited P-LF and decreased F-actin content in murine peritoneal macrophages. A combination of DFMO and MO with EGF failed to inhibit P-LF or to decrease F-actin content in these cells. The results obtained with DFMO and MO suggested new cellular targets of their effects. These results may be extended to cancer research to provide a rationale for clinical trials using combinations of EGF with DFMO or MO.

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[Effect of some DNA-intercalators and antioxidants on the phagosome- lysosome fusion and F-actin content in murine peritoneal macrophages].

Effect of DNA-intercalators ethidium bromide (EB, 0.005 and 0.015 mM) and dimidium bromide (DB, 0.005 and 0.010 mM) and antioxidative compounds acetylsalicylic acid (ASA, 0.05 and 0.50 mM) and beta-carotene (0.01, 0.02, 0.05 mM) on the phagosome-lysosome (P-L) fusion and F-actin content in murine peritoneal macrophages were studied. EB, DB, ASA and beta-carotene were found to stimulate P-L fusion and the effect depending on the concentration of compounds tested. The strongest influence as evoked by 0.5 mM of ASA and 0.05 mM of beta-carotene. The compounds tested enhanced the F-actin content in macrophages, especially by the action of beta-carotene (0.05 mM). The obtained data indicate a correlation between P-L fusion stimulation and F-actin content under the influence of compounds tested in murine peritoneal macropheages.

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[The effect of biologically active compounds on lysosome fusion with phagosomes and the F-actin content in mouse peritoneal macrophages and on the status of the lysosomal membranes in mouse hepatocytes].

Effects of biologically active compounds bilirubin (BR, 0.1 and 0.2 mM), chelerythrine (CR, 0.1 and 0.5 mM) and farmorubicin (FR, 0.6 and 6.0 mM) on the phagosome-lysosome fusion (P-LF) were studied using fluorescent dye acridine orange for lysosomal labelling and yeast cells as a target. To investigate mechanisms of these effects, changes in fluidity of lysosomal membranes from murine liver were studied by measuring of fluorescence intensity, lifetime and polarization of the fluorescent membrane probes: DPH (1,6-diphenyl-1,3,5-hexatriene) and TMA-DPH [1-(4-triphenylamino)-6-phenyl-1,3,5-hexatriene] incorporated in isolated murine liver lysosomes. In order to characterize the induced cytoskeleton changes, the F-actin content in murine peritoneal macrophages was determined. It was found that all three compounds tested enhanced P-LF. Our results demonstrate that BR induces a decrease in DPH and TMA-DPH fluorescence polarization, FR increases DPH and TMA-DPH fluorescence polarization, and CR causes an increase in TMA-DPH fluorescence polarization in lysosomal membranes. All the three compounds increase F-actin content in peritoneal macrophages. Thus, the action of BR extended on P-LF is associated with increasing lysosomal membranes fluidity and cytoskeleton changes. The enhancement of P-LF under the action of FR and CR can be most likely explained by changes of cytoskeleton.

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[The vacuolar apparatus and membrane fusion in the cell].

Current literature on the structure of vacuolar apparatus and its involvement in the process of intracellular transport has been reviewed. Modern views on endocytosis and its particular steps are described. Special attention is paid to one of important steps of endocytosis-the phagosome-lysosome fusion, its disturbance under the action of pathogenic microorganisms, its inhibition and stimulation by some chemical factors and biologically active compounds. The authors widely used their own experimental data. Much attention is paid to the current notions on the fusion pore structure and function, as well as on fusion mechanisms of biological membranes and factors regulating this process.

Animals↗

Effects of spermidine on function and ultrastructure of alveolar macrophages.

It is known that spermidine and other naturally occurring polyamines accumulate in rat lung slices by an energy-dependent uptake process and that alveolar macrophages (AM) have a greater rate of uptake than has the total lung cell population. In the present study rat AMs were incubated with spermidine, which resulted in a marked and significant (P < 0.002) decrease in phagocytosis of heat-killed yeast cells at concentrations 0.2 and 0.5 mM and a tendency to decrease at 0.05 mM. The number of microtubules surrounding the centrioles was measured using electron microscopy and appeared to be decreased at concentrations 0.2 and 0.5 mM. There was no affect on phagolysosomal pH. The results suggest that spermidine might affect the defense against inhaled pollutants and microbes, especially when spermidine levels are increased, as they are under conditions with high mitotic activity, e.g., in tumors.

Animals↗

[The protein spectrum and thermostability of the lysosomal hydrolases in heat-resistant sublines of Chinese hamster cells].

It has been shown by electrophoresis that the earlier obtained thermoresistant sublines of the CHO-K1 cell line do not accumulate heat shock proteins when cultured at 37 degrees C. The thermostability of two lysosomal proteins--acid lipase and acid phosphatase--were higher in the thermoresistant cells than in the parental cells, whereas no differences in thermostability of galactosidase were found between heat resistant and parental lines. Thus, it is concluded that changes in the level of conformational flexibility of protein molecules may be one of the mechanisms of cell adaptation to growth at higher temperatures.

Animals↗

[The effect of different antitubercular agents on phagosome fusion with lysosomes, on the F-actin content in mouse peritoneal macrophages and on G-actin polymerization in vitro].

Effects of various antituberculosis remedies (ATR)--isoniazid (INA), saluzid (SA), streptosaluzid (SS), ethambutol (EB), sodium para-aminosalicylate (SPAS) on phagosome-lysosome (PL) fusion, on F-actin content in mouse macrophages and on G-actin polymerization in vitro were studied. The ATR of choice have been shown to stimulate the PL fusion. INA (0.2 mM), SA (0.02 mM), SS (0.05 mM), EB (0.08 mM) and SPAS (0.5 mM) increased the F-actin content and changed its localization within macrophages. ATR changed the character of G-actin polymerization in vitro. Possible mechanisms of interrelation between cytoskeleton (actin part) changes and PL fusion are discussed. The results obtained suggest to use the ATR-induced changes in PL fusion and F-actin content in the cells for estimating therapeutic effects of respective antituberculosis remedies.

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[Autoradiographic and biochemical studies of protein synthesis in nucleated erythrocytes during the formation of their segregation apparatus].

It has been shown that during novocaine (4.6 x 10(-3) M) induced formation of the segregation apparatus (SA) the total protein synthesis decreases, the synthesis of certain proteins being characterized by a high rate turnover. In the intact erythrocytes, 1 x 10(-2) cycloheximide (CHM) inhibits the novocaine induced formation of segregation apparatus (SA) and protein synthesis by 90%. The combined action of novocaine and CHM on erythrocytes is accompanied by a decrease in CHM inhibiting effect on protein synthesis. This effect retains for 1.5 h during the action of both compounds. Some vacuoles of SA disposed cytochemically exposed acid phosphatase (AP), which enabled us to consider these as lysosomes. According to AP distribution in lysosomes, they can be classified into 3 groups. In group 1 AP is distributed along the membrane of vacuoles, in group 2 it is associated with the material inside the lysosome, and in group 3 the enzyme is both distributed along the membrane and associated with the material enclosed within the segregation vacuole. Such a mode of AP distribution reflects presumably the functional heterogeneity of lysosomes.

Acid Phosphatase↗

[The effect of chemical agents on lysosome fusion with phagosomes and on the F-actin content in murine peritoneal macrophages].

The influence of natural and synthetic polyamines, phalloidin, cytochalasin D, vinblastine, colchicine, puromycin, chlorpromazine, urea, glutaraldehyde, and ethanol on the phagosome-lysosome fusion and the content of F-actin in murine peritoneal macrophages has been studied. Fluorescent phallotoxin FITC-phalloidin was used to stain F-actin. Natural polyamines (spermine, spermidine, putrescine), phalloidin, ethanol (0.1 M) stimulated the phagosome-lysosome fusion and increased the mid-content of F-actin in macrophages. Cytochalasin D, vinblastine, colchicine, puromycin, chlorpromazine, urea, glutaraldehyde, ethanol (0.15 and 0.2 M) inhibited this process and decreased the mid-content of F-actin. Possible mechanisms of the interconnection of cytoskeleton and the phagosome-lysosome fusion are discussed.

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[The role of phagocytic cells in the pathogenesis of idiopathic fibrosing alveolitis].

The paper deals with the examination of the role of phagocytes--alveolar macrophages and neutrophils--and peripheral monocytes, in the pathogenesis of idiopathic fibrosing alveolitis (IFA). As the disease aggravates, activation of the absorbing capacity of monocyte-macrophagal cells corresponds to a sharp rise in the level of circulating immune complexes in the blood of IFA patients. Higher activities of elastase and collagenase are observed in the IFA patients' bronchial lavage fluid.

Adult↗

[The effect of diamines on the process of lysosome fusion with phagosomes in mouse peritoneal macrophages].

Diamines (DA), characterized by a general formula H2N-(CH2) n-NH2 in which n varies from 2 to 10, inhibit the phagosome-lysosome fusion in murine peritoneal macrophages. The DA concentration was 0.2, 0.5 and 1.0 mM. The inhibitory effect increased with increasing the number of CH2-groups in the DA molecule. It was suggested that DA could influence the lysosomal membrane state. An additional proof of such changes was obtained with 1,6-diphenyl-1,3,5-hexatrien (DPH) as a fluorescent probe. Lysosomes isolated from murine peritoneal macrophages by differential centrifugation were used. It was found that DPH fluorescence intensity in lysosomal membrane increased under the influence of DA.

Animals↗

[Lysosomal enzymes and natural killer activity].

The natural killer activity (NKA) of human mononuclear cells and the activity of the lysosomal enzymes of these cells (arylsulfatase, acid phosphatase and beta-glucuronidase) has been studied in norm and under human lung cancer. The mononuclear cells were isolated from peripheral blood of 10 healthy donors and 20 patients with lung cancer of II-III stages. Under the action of mononuclear cells on the target cells (human erythroleukosis cells K-562 labeled with 3H-uridine) the NKA of mononuclear cells of patients was seen to decrease (cytotoxic index = 54.8 +/- 6.4%), in comparison with that of healthy donors (cytotoxic index = 65.1 +/- 4.5%). Simultaneously a decrease in arylsulfatase activity (0.05 +/- 0.01 nmoles/10(6) cells/min) was found in comparison with the control value (0.11 +/- 0.01 nmoles/10(6) cells/min). In 2-3 weeks after the operation the NKA value (cytotoxic index = 50.2 +/- 5.8%) was restored and arylsulfatase activity (0.09 +/- 0.02 nmoles/10(6) cells/min) was increased. There was no correlation between the NKA value and the activities of acid phosphatase and beta-glucuronidase. The parallelism observed between changes in NKA value and arylsulfatase activity may suggest a possible participation of this enzyme in the killing mechanism at the stage of cerebroside sulfate ester degradation of the target cell membrane to initiate the lytic events.

Acid Phosphatase↗

[The effect of oligomycin and cycloheximide on the ultrastructure of the segregation apparatus and on protein synthesis in the erythrocytes of the common frog].

The incubation of frog erythrocytes in the Ringer solution with novocaine (4.6 x 10(-3) M) during 24 hours at 10 degrees C provoked vacuole formation (segregation zones). Changes of the novocaine solution for a fresh Ringer solution and the following 48 hour incubation was accompanied by a decrease in the number of vacuoles both electron-translucent and containing membranous material. Simultaneously, the number of vacuoles with amorphous material only and with amorphous and membranous substances was seen to increase. Under the action of cycloheximide (1.10(-2) M) or oligomycin (2.5 x 10(-6) M) on erythrocytes with preformed vacuoles for 48 hours the total number of vacuoles and their dimensions decreased, with numerous amorphous inclusions appearing. Vacuoles with amorphous and membranous material increased in size. Similar ultrastructural changes in the segregation zones under the influence of both the inhibitors were observed showing the appearance of thick threads and a decreased share of electron-translucent vacuoles. A specific effect of cycloheximide, compared to that of oligomycin, involved the expansion of smooth endoplasmic reticulum cisternae. Under the influence of novocaine, 3H-leucin incorporation in proteins of frog erythrocytes was intensified. However, this incorporation was considerably inhibited by cycloheximide. Erythrocytes with segregation zones were more inhibitor susceptible than erythrocytes without vacuoles. The inhibitory effect was stronger early after their administration to the incubation medium, compared to the later periods.

Animals↗

[The effect of polyamines on lysosome fusion with phagosomes in mouse peritoneal macrophages].

The influence of polyamines on the phagosome-lysosome fusion in murine peritoneal macrophages and on polymerization of G-actin from the rabbit muscle in vitro has been studied. Both natural polyamines (spermin, spermidin, putrescin) and synthetic phenyl derivates of polyamines (3,3'-diaminobensidin, 1,5-naphtalin diamine, 4,4'-diaminodiphenilmetan, dancylcadaverin) were used. Unlike the phenyl derivates of polyamines and putrescin, spermin and spermidin stimulate the phagosome-lysosome fusion to induce G-actin polymerization. Possible mechanisms of action of the above polyamines are discussed.

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