PubMed Health⌕ Search

Biomedical subjects

G Popov

Publications and source records attributed to G Popov.

At least 19 recordsLinked to original sources
PubMed1991

[A case report of visceral leishmaniasis].

A brief review of the spread of visceral leishmaniasis in Bulgaria and data about the disease are presented. A case of probably nonautochtonous form of visceral leishmaniasis is described. The clinical evolution of the disease is followed up and the large number of examinations which were carried out for the etiological diagnosis are presented. The diagnosis is based on the characteristic clinical symptoms, epidemiological history, positive serologic tests but with a negative myelogram. The diagnosis was proved ex juvantibus by the antimony treatment and the full recovery of the patient. This is the first case of visceral leishmaniasis in the 40 year history of the hospital.

Adult↗
PubMed1988

Five year study of rotavirus gastroenteritis in Bulgaria.

We tested by electron microscopy 7,530 samples from children admitted to different hospitals in Sofia between February 1981 and February 1986; from these, rotaviruses were found in 725 (9.6%) faecal samples. Electron microscopic analysis of 264 samples from 181 children admitted to the hospital of infectious diseases in Shumen between December 1984 to February 1986 revealed rotaviruses in 120 (66.6%) of the tested children. A part of the samples positive by electron microscopy was tested by ELISA and polyacrylamide gel electrophoresis for rotavirus RNA segment patterns. Rotaviruses with eight different electropherotypes were found in Bulgaria. The seasonal culmination of the rotavirus gastroenteritis in the winter months has been confirmed. Rotavirus antibodies were found in 73% of the sera from 152 children tested.

Bulgaria↗
PubMed1988

[Gamma-glutamyltransferase activity in the serum and the mean-cell erythrocyte volume of patients with chronic ethylism and chronic liver diseases (preliminary report)].

The dynamics of the enzyme gamma-glutamyltransferase (gamma GT) was followed up in 34 patients: 17 patients with liver cirrhosis, 9 patients with chronic hepatitis and 8 patients with liver steatosis. In the patients with alcoholic cirrhosis the activity of gamma GT rapidly fell in hospital conditions which is related to the forced abstinence. In the cirrhotic patients with nonalcoholic etiology no changes in gamma GT activity were found. In the patients with chronic hepatitis and liver steatosis with alcoholic etiology the gamma GT activity resembled that of alcoholic cirrhotic patients. The gamma GT activity fell most sharply in the patients with liver steatosis which is explained by the mild and reversible liver lesions characteristic for this disease. The mean erythrocyte volume determined by electronic blood cell counter shows a tendency toward macrocytosis in all chronic alcoholic patients. Macrocytosis is also found by ordinary microscopic examination of the blood cells.

Adult↗
PubMed1987

[Etiological study of viral gastroenteritis in swine].

Studied were the etiology and spread of nonbacterial gastroenteritis in pigs over a period of five years. Ascertained were cases of diarrhea caused by the virus of transmissive gastroenteritis, epizootic diarrhea, and rotaviruses. The transmissive gastroenteritis virus was found in 14.1 per cent of the investigated material, mostly in the winter months (67.8 per cent), which was 65.6 per cent of the positive cases. The number of cases and that of the farms involved abruptly rose in the last two years of the investigated period when as many as 73.4 per cent of the positive findings were recorded. Thirty to 37.7 per cent of the studied farms proved to be infected. Enzootic diarrhea was recorded on seven out of the 12 studied farms, whereas 30 to 50 per cent of the sampled material was positive. The serologic study of reconvalescent blood sera of pigs from three infected farms revealed that 90 up to 100 per cent of them contained antibodies. In a great part of the sera (from 15 to 68.9 per cent) there were transmissive gastroenteritis antibodies as well. In 6.8 per cent of the Investigated samples and on 30 per cent of the farms there were also findings of rotaviruses. Cases of rotavirus gastroenteritis were recorded the year round with a rising trend in the cold months. Antibodies to these viruses were established on a large scale--from 58.13 to 100 per cent. There were also mixed infections--corona- and rotaviruses or viruses and bacteria.

Animals↗
PubMed1987

[Demonstration of a reovirus in helicopter disease of broilers].

A reovirus was isolated from 5-13-day-old broiler birds with signs of the so-called helicopter disease--one of the forms of the malabsorption syndrome. A number of organs were investigated (trachea, liver, spleen, bursa of Fabricius, proventricular stomach, and tendon sheath of musculus gastrocnemius). The virus was isolated from the proventricular stomach and the tendon sheath in cell cultures of chick embryo kidney as well as in 5-7-day-old chick embryos inoculated in the yolk sac. The remaining organs proved virologically negative. All organs, including the primarily positive ones, were shown to be virologically negative upon the inoculation of chick embryo fibroblast cultures and of chorioallantoic membranes of 10-11-day-old chick embryos. The isolate was identified as an avian reovirus, and was denoted with the initials R-85--on the grounds of its biologic and physico-chemical properties, of its morphology (negative-contrast electron microscopy), and of its morphogenesis (ultrathin electron-microscopic cross sections). Investigated were the histopathologic changes in chick embryos inoculated with the R-85 reovirus and the pathologic changes in the liver of spontaneously affected birds.

Animals↗
PubMed1987

[Electron microscopic methods for the rapid diagnosis of Q fever in animals].

Methods have been worked out for the electron-microscopic diagnosis of Q-fever. A characteristic feature with them is the use of clinical, pathological, and experimental material that is investigated through negative contrast and ultra thin sections for the detection of rickettsial cells and inclusions. It is underlined that the methods referred to are readily applicable, economic, highly effective, and hazardless. They are described for the first time and could be adopted into the diagnostic and epizootiologic practice as well as in experimental investigations.

Abortion, Veterinary↗
PubMed1986

[Rotavirus infections in pigs].

Rotaviruses were found in the study of 123 pigs and 132 fecal samples from animals with diarrhea. Employed were the method of immunofluorescence and the high concentration of virions (10(4) up to 10(9)/cm3). As high as 57.3 per cent of the fecal extracts proved positive for rotaviruses. In 14.3 per cent of the extracts a group-specific rotavirus antigen was established via the agar gel immunodiffusion, and 30.9 per cent of the intestinal cross sections were positive as demonstrated through immunofluorescence. Conditionally, the cases of rotavirus gastroenteritis are divided into two types--early and late. The first ones have been seen in sucking piglest at the age of 10-15 days, and with the growing of the epizootic wave--in 3-day-old ones, too. The second type of rotavirus gastroenteritis have been described in young pigs fifteen days after weaning, The death rate with sucking pigs was found to vary from 7 to 17 per cent, and it was 5 per cent with weaned ones. High mortality rate (82 per cent) was observed on a farm where a mixed infection with transmissive gastroenteritis was noted. The diagnosed cases of rotavirus enteritis prevailed in the cold months of the year (autumn-winter). On two farms the disease was established in the summer. The serologic examination of the blood sera of sows revealed group-specific antibodies to rotaviruses in 71 per cent of the cases. The percent of seroagents with the young sows ranged from 50 to 63.3 per cent, while with the adult ones it was 87 to 100 per cent. Discussed is the link between the low titer of natural immunity and the aspects of the epizootic process with rotavirus diarrhea.

Animals↗
PubMed1986

[Epizootic enteritis in pigs].

Studied was the etiology of diarrhea in sucking pigs, using animals aged up to seven days, that had suffered from the disease not longer than 24 hours on 12 farms. There were cases of diarrhea induced by the virus of epidemic diarrhea. The virus was characterized morphologically through electron microscopy, and antigenically through direct immunofluorescence and serologic investigation. The disease was distinguished from transmissive gastroenteritis via differential diagnosis. Demonstrated was the lack of cross antigenic relation between the two viruses.

Animals↗
PubMed1985

[Experiments to purify and concentrate the foot-and-mouth disease virus].

Experiments were carried out for the purification and concentration of the foot-and-mouth disease virus. For the purpose the virus suspensions were treated with chloroform and 8 per cent polyethylene glycol. The precipitated virus was eluated with phosphate buffer (of pH 7.6) up to 1:100 of the initial volume. The concentrated virus was subjected to gradient ultracentrifugation on gradient of CsCl. The fractions obtained were investigated through radial immunodiffusion reaction with early sera, containing IgM antibodies. The fractions that formed circles of precipitation were studied under electron microscope at negative contrasting. It was found that the fractions taken from between the CsCl layer of 1.42 g/cm3 density and the underlying CsCl layer of 1.50 g/cm3 density, which produced precipitation circles in the radial immunodiffusion test, contained purified virions of intact structure in concentration of 10(9).

Animals↗
PubMed1985

[Use of a concentrated and purified vaccine against chlamydial abortion in sheep].

Attempts were made to immunize sheep against chlamydial abortion with a purified, concentrated, and absorbed vaccine. The latter proved innocuous and unreactive, and was applied at rates of 0.5 to 1.00 cm3. It was found that at a single vaccination of the sheep with 0.5 cm3 as many as 91.42 per cent responded with the production of antichlamydial complement-fixing antibodies on the 45th day of 1:8 to 1:512 titers; 96.43 per cent of the animals responded on the 111th day, the titers ranging from 1:8 to 1:256. At twofold vaccination on the 1st and the 45th day with 0.5 and 1.00 cm3 vaccine, respectively, 100% of the sheep showed antibodies on the 111th day, the titers being within the 1:16 to 1:256 range 49.69 per cent showed antibodies on the 260th day within the 1:4 to 1:512 range. No abortions, stillbirths, and birth of underdeveloped lambs were seen.

Abortion, Veterinary↗
PubMed1985

[Chlamydial infection in pericarditis in pigs].

An etiologic study was carried out for the presence of Chlamydia in the case of pericarditis in pigs on a large swine-breeding complex. Investigated were some clinical, epizootiologic, and morphologic aspects of the disease. A strain of Chlamydia psittaci was isolated in chick embryos from pericardial liquids of affected animals. It was identified through electron-microscopic and antigenic studies. Elementary and initial bodies of Chlamydia were seen in ultrathin sections of the infected yolk sacs. Eatherial-and-acetone group-specific antigens that were purified on Sepharose 2B and 4B were obtained. The disease was contracted chiefly by pigs at the age of 30-70 days. The clinical picture was not strictly indicative. Disease cases were recorded in all seasons of the year. Both the gross lesions and the histologic findings spoke of serofibrinous pericarditis.

Animals↗
PubMed1984

[Clinical etiological findings in chlamydial urethritis in men].

120 patients with abacterial urethritis were studied for chlamydia. Clinical, cytological, serologic and electronenmicroscopic tests were performed. 66.60% of the tested persons were seropositive for C. trachomatis, 32.50% of all patients and 48.80% of the seropositive patients showed positive cytological tests. Direct electron microscopy of biopsy material of the urethra of 30 patients revealed chlamydial bodies in high concentrations. The incubation period was about 1-2 weeks. Oxytetracycline was used for 8 days, but had to be one- to four times repeated in resistent cases.

Adult↗
PubMed1984

[Our experience in the preparation and use of group-specific chlamydial antigens].

Described is a modified method for the production of etherial-acetone antigens used in the complement-fixation test (CFT). It is characterized by a two-fold etherial extraction and an electron-microscopic control over the strains and the chlamydial suspensions to be used as initial material. The antigens obtained by the modified method are said to have high titers, stability, and high specific activity, are long-lasting, and do not produce anticomplement reactions. A new method has been worked out for the production of concentrated and purified chlamydial antigens for CFT, employing column chromatography on Sepharose 2B or 4B. The antigens obtained are highly active and specific. Results have shown that the use of the highly purified chlamydial antigens for CFT is very promising.

Animals↗
PubMed1984

[Morphology and morphogenesis of Aujeszky's disease virus (the viral mutant MK-35 and virulent strain 2)].

Ultrastructural studies were carried out on the morphology and morphogenesis of the Aujeszky's disease avirulent immunogenic mutant strain MK 35 and the virulent parental strain 2. It was found that MK 35 had a delayed cycle of replication, lasting about 10 hours as against the virulent strain 2. It also induced specific cytomorphology of the infected cells as well as the synthesis of a predominantly virus antigen in the form of empty viral capsids of tubular shape. THe culturing of the virulent strain in cell cultures in the presence of the antimetabolite 5-brom-desoxiuridine led to the synthesis of a limited amount of mature viral particles. Characteristic proved, the production, although in small amounts, of empty viral capsids. This process was observed after the 24th hour of infection of the cell cultures.

Animals↗
PubMed1983

[A method of production of concentrated and purified vaccine against Chlamydia abortion in sheep and its testing in guinea pigs].

A method was developed for the production of a new, present day, concentrated depot-vaccine against the chlamydial abortion of sheep. Employed were a number of methods -- those with chick embryos, freezing and thawing with the use of liquid nitrogen, inactivation with formalin, purifying and concentration through differential centrifugation and supercentrifugation, with the use of an aluminum hydroxide ingredient, electron microscopy, and the respective control series, etc. The vaccine is characterized by low dosing, complete innocuity, and unreactiveness. Guinea pigs immunized singly responded with the production of complement-fixing antibodies on the 30th day of an average titer ranging from 1:32 to 1:64. Two-fold immunization on the 1st and 30th day led to the production of antibodies of average titers within the 1:256-1:512 range as established by means of CFT. The vaccine was shown to have a low prime cost.

Abortion, Veterinary↗