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Biomedical subjects

V Dimov

Publications and source records attributed to V Dimov.

At least 19 recordsLinked to original sources
PubMed1993

Effect of oxadiarrhot on some mechanisms of the immune system.

The preliminary application of the preparation Oxadiarrhot has no effect on the progress and the result of bacterial and mixed (bacterial-viral) infections. In animals treated with the preparation antigen-reactive and antibody-productive cells show insignificant decrease in number. There is no essential influence of the preparation on the mononuclear phagocytes system--the alveolar macrophages and polymorphonuclears do not change their functions.

Animals↗
PubMed1993

Immunological and biochemical investigations of the infectious bovine rhinotracheitis. III. Alterations in pulmonary surfactant lipids.

The effect of experimental bovine herpes virus (BHV) type I rhinotracheitis on the surfactant system phospholipids in calves was examined. A stimulated exocytosis of pulmonary surfactant phospholipids in the acute phase of the disease was documented biochemically and ultrastructurally. The data presented were assumed as an evidence of the involvement of pulmonary surfactant in lung defense.

Animals↗
PubMed1993

Chemiluminescent activity of macrophages during phagocytosis of different bacterial forms.

Studies on the luminol-dependent chemiluminescent activity of rat peritoneal macrophages after in vitro interactions with E. coli WF+ L-form cells, their cytoplasmic membranes (CM) or parent bacterial cells were carried out. It was established that the phagocytosis of CM induce 20 time stronger light emission as compared to the L-form and 40 times compared to the parent bacterium cells respectively. Electron microscopical investigation of ultrathin sections of rat peritoneal macrophages after 24 h interaction in vitro with CM showed activation of the cell surfaces and vacuolisation of the cytoplasm. Inhibition of the phagolysosome fusion during phagocytosis of CM was observed. The mechanism of the immunostimulating activity of CM is discussed.

Animals↗
PubMed1992

Polyphenols from Bulgarian medicinal plants with anti-infectious activity.

Three Bulgarian medicinal plants--Geranium macrorrhizum L. and G. sanguineum L. (Geraniaceae), and Epilobium hirsutum L. (Onagraceae) were analyzed phytochemically. Different polyphenols like flavonoids and tannis have been found to be principal constituents of the plants. A series of water or alcohol extracts was obtained, and their anti-infectious activity was tested. A significant inhibitory effect of water-alcohol extract and of four fractions from the polyphenolic mixture of E. hirsutum on the reproduction of influenza viruses in vitro, in ovo, and in vivo was established. Four extracts from G. macrorrhizum and three extracts from G. sanguineum were studied for in vitro inhibition of the growth of some Gram-negative bacteria (Klebsiella pneumoniae, Proteus vulgaris, Escherichia coli, Pseudomonas aeruginosa), Gram-positive bacterium (Staphylococcus aureus), and fungus (Candida albicans). Some geranium extracts caused a strong increase of the survival rate in an infection with K. pneumoniae in mice. Augmentation of the nonspecific host resistance in relation to the influence of the extracts on the classical complement activation pathway was also studied.

Animals↗
PubMed1992

Immunomodulatory action of propolis: IV. Prophylactic activity against gram-negative infections and adjuvant effect of the water-soluble derivative.

The efficacy of the water-soluble derivative (WSD) of natural propolis (bee glue) was examined for augmentation of host resistance against experimental infections caused by Gram-negative pathogens (Klebsiella pneumoniae, Proteus vulgaris, Escherichia coli, Pseudomonas aeruginosa). The substance was found to induce significant non-specific protection, but did not inhibit the in vitro growth of the same strains. Pretreatment with WSD prior to the standard scheme for tumour necrosis factor (TNF) induction (BCG and two weeks later lipopolysaccharide (LPS)) provoked an interval-dependent reduction in the lytic capacity of serum against L 929 target cells. The replacement of the triggering or priming signal with WSD markedly increased TNF production. In vivo administration of WSD led to a rapid and route-dependent change in the alternative complement pathway haemolysis. The alteration in C1q complement component and total protein synthesis, and also in nitroblue tetrazolium reduction, suggests that macrophage activation makes a major contribution to the capacity of WSD to prevent infections.

Adjuvants, Immunologic↗
PubMed1990

[The immunostimulating action of suramin in infection with the infectious rhinotracheitis virus].

The immunostimulating antiviral preparation suramin has a favourable effect on the process and outcome of an experimental infection with the virus of infectious rhinotracheitis (bovine herpes virus type 1, BHV1), thus reducing the gravity of the clinical course and increasing the survival rate. The therapeutic protective effect of the preparation is expressed in the prevention of virus-induced immunosuppression which is markedly strong during the acute phase of the infection process. Suramin restored the number, viability, relative share in the bronchial lavage population, phagocytic and microbicidal capacity of the alveolar macrophages--a major factor of the local defence mechanisms of the lung. In a similar way suramin influenced some parameters of the systemic immunity (number and differential count of polymorphonuclear phagocytes, plaque- and rosette-forming cells). The application of suramin in doses lower than those used for virus inhibition and its considerable action on different mechanisms of the immune system suggested that the preparation's therapeutic effect could be related mainly to its immunostimulating properties.

Adjuvants, Immunologic↗
PubMed1990

[Immunosuppression in an experimental infection with the infectious rhinotracheitis virus].

The changes in the immune status of the calves infected with bovine herpes virus-1 inducing infectious rhinotracheitis were studied. The virus was introduced by intratracheal inoculation of 5 cm3 suspension with minimal concentration of 10(-7) CPU50 per 1 cm2 from the Cervena voda strain cultivated in calf kidney culture. An infection of moderate seriousness and characteristic clinical manifestations was caused. On the 2nd, 5th, 10th and 15th day after the infection lung lavage was carried out and samples were taken from the peripheral blood. The number, viability and differential distribution of the alveolar macrophages and phagocytic and microbicidal ability showed a tendency to decrease during the acute phase of the infection (the 2nd-5th day) followed by a slow restoration in the period of convalescence (the 15th day). Some parameters of the systemic immunity--number of the plaque-forming and the rosette-forming cells, differential and absolute number of leucocytes in the peripheral blood--also had similar dynamics. The changes in the local and in the systemic, in the cell and humoral immunity were connected to the pathogenesis of the infection and the immune suppressive properties of the agent. The rhinotracheitis infection is indicative of the character of changes in the immune status at herpes virus infections and, on the other hand, it can be used as a model for testing immunostimulators of recovery effect.

Animals↗
PubMed1983

Analysis of prostaglandins formed from endogenous and exogenous arachidonic acid in homogenates of human reproductive tissues.

Isotope-labelled arachidonic acid has been used to study in vitro formation of prostaglandins and other products in mammalian tissue. Quantitative conclusions about cyclooxygenase activity have been drawn from such studies. However, arachidonic acid is present in all tissues, free and esterified, and therefore it can be expected that endogenous arachidonate would interfere with transformation of the radioactive exogenous substrate. (1-14C)-labelled arachidonate was, therefore, incubated with homogenates of various human tissues (amnion, chrorion, placenta and myometrium), and the two molecular forms, 12C and 14C, of arachidonic acid as well as of prostaglandin E2 and prostaglandin F2 alpha were quantitated, before and after 30 min of incubation, using gas chromatography-mass spectrometry with multiple ion detection. The results demonstrate a substantial release of arachidonic acid into the medium during incubation. There was no correlation between either the initial concentration of [12C]arachidonic acid and initial concentration of [12C]prostaglandin E2 or the percent increase of those compounds during incubation. The net formation of [12C]prostaglandin E2 and [14C]prostaglandin E2 from endogenous and exogenous precursor, respectively, were also very different. The study shows that by simply incubating (1-14C)-labelled arachidonic acid in tissue homogenates and measuring the amount of radioactivity transformed into various prostaglandins only qualitative conclusions can be drawn.

Amnion↗
PubMed1983

Gas chromatographic--mass spectrometric quantitation of 16, 16-dimethyl-trans-delta 2-PGE1.

Di-deuterated and di-tritiated 16,16-dimethyl-trans-delta 2-PGE1 has been synthesized and used for development of a GC-MS method for quantitation of corresponding unlabelled drug in patient plasma. Although these carrier/internal standard molecules only contain 2 deuterium atoms the lower limit of detection at each injection is as low as about 40 pg. The maximum plasma levels of this drug following administration of vaginal suppositories used in clinical studies (1 mg 16,16-dimethyl-trans-delta 2-PGE1 methyl ester in 0.8 g Witepsol S-52) were 100-350 pg/ml i.e. in the same order of magnitude as earlier seen for 16,16-dimethyl-PGE2.

Alprostadil↗
PubMed1983

[Results of impregnating cows and heifers on consolidated farms and the methods for synchronizing their estrus].

Studied were the conception rate, milk productivity, calving period, and age at first conception with 3265 cows of 12 herds and 3 breed groups--Bulgarian Red Cattle (BRC), Holstein-Friesian Cattle (HFC), and HFC X BRC. The effect was followed up of the enzyme preparations Cytochrome 'C' and Beta-glucuronidase on the conception rate of cows. Tested was the action of prostaglandin F2 alpha and its analogues Equimate, Luteolysine, and Panazelen on the synchronization of the estrus and the conception. It was found that there was a considerable delay in the calving of the heifers (29 months). The calving period of the cows was prolonged and ranged in days from 369.17 +/- 3.17 up to 381.26 +/- 8.61 for BRC, 378.09 +/- 3.56 to 393.21 +/- 14.85--for HFC, and 339.75 +/- 6.56 to 390.42 +/- 3.51--for HFC X BRC. The use of Beta-glucuronidase and Cytochrome 'C' in the artificial insemination of the cows with deep-frozen semen raised the conception rate at first insemination by about 8-10 per cent.

Animals↗