PubMed Health⌕ Search

Biomedical subjects

Kh Kharalambiev

Publications and source records attributed to Kh Kharalambiev.

12 recordsLinked to original sources
PubMed1979

[Purification of coronaviruses from contaminated cattle feces].

A scheme was worked out for the obtaining of purified Corona viruses from fecal extracts, which include: centrifugation in an discontinued gradient of sucrose 20--45 per cent, gel filtration through a Sephadex 4B column, and centrifugation in a linear gradient of sucrose 10--50 per cent. By means of such purification the virions remain morphologically intact in sucrose density of 1.11--1.14 gr/cm3, containing no ballast proteins. As many as five polypeptides are demonstrated in polyacrylamide electrophoresis.

Animals↗
PubMed1978

[Corona- and rotavirus enteritis in newborn calves in Bulgaria].

In the course of investigations into enteritis enzootics in newly-born calves, 55 fecal samples have been studied through direct electron microscopy by the negative contrast method. Rota viruses were found in eight of them, corona viruses in 38.2 per cent of the cases, and both rota- and corona viruses in 49.1 per cent of the cases. Two types of rota-viral particles were observed: with and without supercapsids. Also two types of corona-viral particles were established. The first type was relatively monomorphic, having an average diameter of 120 nm, and length of the surface spikes of 20 nm. The second type was pleomorphic with length of the spikes of 11 nm. Most of the fecal samples, containing corona viruses, agglutinate mice, rat and hamster erythrocytes. On studying the physical and chemical properties of the hemagglutinine, ist gradient density and antigenic patterns it was shown that it is related to the intact corona-virions. With the hemagglutination-inhibition test developed, antibodies against corona-viruses in the sera of a considerable number of the cows have been demonstrated. A precipitating antigen has been shown in a part of the fecal samples, containing rota-viruses. By studying the physical and chemical properties, its gradient density and its comparison with a refernce antigen, it has been shown that the antigen was conditioned by degraded fragments of rota-viruses. With the aid of the immunodiffusion method with a fecal antigen evolved, precipitating antibodies have been shown in 18 to 46 per cent of the cows and calves.

Animals↗
PubMed1978

[Trials to obtain a hyperimmune serum against bovine mucosal disease-virus diarrhea].

Obtained are two types of hyperimmune sera against the virus of the mucous disease--viral diarrhea (MD--VD) by means of subcutaneous and venous hyperimmunization of cattle with a live viral suspension: (a) A polyvariant hyperimmune serum, obtained by the use of four local and reference strains of the MD--VD virus with a neutralization titre against the Nadl strain of 1 : 1280. (b) Monovariant hyperimmune serum, prepared by the use of a reference strain of the MD--VD virus with a neutralization titre against the Nadl strain of 1 : 1280. On testing experimental calves and application in practice, it has not been established that the polyvariant serum possesses a marked protective effect at a dose of 1 cm3/kg.

Animals↗
PubMed1977

[Immunoprophylaxis of infectious bovine rhinotracheitis].

The live attenuated vaccine against infectious rhinotracheitis (LAV), the live trivaccine against infectious rhinotracheitis (LT), the concentrated etanolsaponin vaccine against infectious rhinotracheitis (CESV) and the ethanol-saponin vaccine against infectious rhinotracheitis (ESV) can all be used as immunoprophylactic means in the control of infectious rhinotracheitis in cattle. The first two live vaccines are applied to calves in infection foci, and the two inactivated vaccines are used with cows. The comparative testing of CESV and ESV in experimental conditions on calves has shown that the first possesses higher immunogenicity--used in a twice lower dose it produces several times higher level of the neutralizing antibodies against the infectious rhinotracheitis virus. The use of LAV and LT in the practice under the conditions of established infections of infectious rhinotracheitis in calves has given good results. The immunization of calves at the immediate menace of this infection has lowered the morbidity rate, and death cases were no longer observed. The use of CESV and ESV with pregnant cows on a prophylactic basis against infectious rhinotracheitis has also given good results manifested in the full suppression of abortions.

Animals↗
PubMed1976

[Studies of the complement fixation reaction in infectious rhinotracheitis in cattle].

The complement-fixation reaction was used in the diagnosis of infectious bovine rhinotracheitis establishing its specificity and effectiveness. Highest titers of the antigens tested (up to 1:16) showed antigens that were concentrated with the use of poly ethylene glycol. In performing the test both the antigen and the complement were used in a dose that contained two units of each of them. Thus the use of the complement-fixation test proved instrumental in determining specific complement-fixing antibodies in animals that had recovered from the disease, or animals that had latent infection or had been vaccinated. The titers established usually ranged from 1:2 to 1:8, and in single cases they reached 1:128. On the infected farms some animals presented both complement-fixing and neutralizing antibodies. In Herds with positive reagents was also isolated the virus of bovine rhinotracheitis.

Animals↗
PubMed1976

[Study of one enzootic of viral diarrhea in calves].

Described is the course of a virus diarrhea in calves aged from 40 up to 180 days, the morbidity rate reaching 50 per cent and the mortality rate--28 per cent. The morphologic survey established erosions and inflammatory lesions in the mouth, abomasum, rumen, and intestines. Histologically, there was balooning degeneration of the cells involved as well as karyopycnosis. Virus strains were isolated from the spleen of diseased calves. They were identified as the causative agent of the virus diarrhea-mucosal disease complex. It was found through immunodiffusion that a specific viral antigen exists in the involved mucous membranes of the intestinal tract. The live vaccine was found to be promising of the immunoprophylactic means tested.

Animals↗