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Biomedical subjects

G Ignatov

Publications and source records attributed to G Ignatov.

At least 19 recordsLinked to original sources
PubMed2000

[Post-gastrectomy reconstruction versus enteral alimentation--a one year follow-up study].

This is a report on various post-gastrectomy reconstructive procedures, proceeding from personal experience had with 14 patients undergoing gastrectomy for carcinoma of the stomach and five patients with operations of esophagus and stomach for various pathological conditions. An assessment is done of the reconstructive methods used on the ground of objective indicators. All patients are subjected to enteral alimentation through nutritive jejunostomy. In the pre- and postoperatived periods, the trophic state of patients is evaluated on basis of biochemical, anthropometric and immunologic study data. Postoperatively, in those with small-intestinal reservoir a lower degree negative symptomatology is established, along with life style improvement. Post-gastrectomy patients presenting I-II (UICC) stage of the oncological disease are indicated for small-intestinal reservoir formation. In the overall therapeutic approach to post-gastrectomy patients adequate clinical therapeutic feeding proves absolutely indispensable.

Aged↗
PubMed1987

[Use of gamma-globulins from the peritoneal fluid of cats with infectious peritonitis for the immunofluorescence demonstration of the TGE antigen].

Peritoneal exudate of a cat affected with feline infectious peritonitis (FIP) was used to isolate an IgG-globulin, employing affinity chromatography, and conjugate it with fluorescein isothiocyanate. The conjugate was tested on cross sections of the small intestine of a pig infected with strain Miller-3 of the transmissive gastroenteritis (TGE) virus, simultaneously with an anti-TGE conjugate of an SPF pig. Identical results were obtained with both conjugates, however, the anti-FIP conjugate had a several-times higher titer. Discussed are the possibilities and advantages of using the anti-FIP conjugate in the immunofluorescence demonstration of the TGE virus antigen.

Animals↗
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

[Mixed coli-rotavirus and Cryptosporidium infection in newborn piglets].

Complex morphologic, parasitologic, virologic, and bacteriologic studies on pigs and fecal samples from pigs were carried out on a farm where an enteritis infection in newborn pigs was recorded. A mixed coli-rotavirus and cryptosporidium infection was established in 10--20-day-old pigs of the Camborough hybrid with a clinically manifested enteritis syndrome. Morphologically, the cryptosporidium component of the infection substantiated atrophic and dystrophic changes in the intestinal epithelium. Developmental forms of the parasite were also found in the border wall of the enterocytes.

Animals↗
PubMed1987

[Pathomorphological changes in the small intestine of pigs with rotavirus diarrhea].

Studied were the pathohistological changes and the morphologic-structural injuries of intestinal mucosa of pigs (5-7 days old), spontaneously affected with rotavirus diarrhea, raised by traditional methods. Simultaneously with the rotavirus invasion was established Isospora suis. In spite of the early time of the disorder (the test was carried out 24 hours after the appearance of the first clinical symptoms) there were established different in degree and expression morphologic changes; atrophy and fusion of the fibrils, replacement of the cylindrical epithelium with cubic, dystrophy and exfoliation of the enterocytes with exposure of the lamina propria. The burden of the dystrophic processes, which has affected the intestinal mycosis, was registered by scanning electronic microscopy. The dystrophic processes start at the top of the intestinal fibrils, the fusion of the fibrils spreads over a big number of them, forming a conglomerate mass. Simultaneously with the fibrils, affected by dystrophy, were observed fibrils with normal shape and size. During immunofluorescent examinations also is observed focal distribution of enterocytes, containing antigen on some of the fibrils. Now is discussed the importance of the pathogenic microflora, in the intestinal track of pigs, raised by traditional methods, for the early appearance and for the burden of the morphologic-structural changes.

Animals↗
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

[The spread of enzootic bovine leukemia via the seminal fluid in certain breeds of bulls].

Studied was the occurrence of enzootic bovine leukosis as dependent on the use of semen of leukosis-affected bulls for the artificial insemination of cows and heifers and their offsprings in the F1 generation on 16 farms. Semen was used of a total of 30 bulls of the Holstein-Friesian, American Brown, and European Black-and-white breeds. The agar gel immuno-diffusion test was employed to establish antibodies to the bovine leukosis virus in the sera of the bulls. On 9 farms with 2,997 cows and heifers that were negative for leukosis antibodies a total of 800 female calves (F1) were born. Serologic investigations of both dams and calves, aged 2 to 5 years revealed no leukosis antibodies. On other 7 farms with 1,717 cows and heifers, among which sporadic carriers of BLV-antibodies were discovered, 713 female offsprings (F1) were born. Seventeen (2.38 per cent) out of these responded positively for BLV antibodies. Twenty-two (3.0 percent) of the dams following calving also showed a positive reaction. Over the 1981-1985 period a total of 1,593 female calves were born as the offsprings of 4,714 cattle on all 16 farms. The percent of the positively responding to leukosis was 1.06, resp., 1.38. These results were considered indicative in ruling out the transmission of enzootic bovine leukosis with semen in the artificial insemination of cows and their F1 offsprings.

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↗
PubMed1984

[Pathomorphology of stachybotryotoxicosis in calves during the nursing period].

An enzootic of stachybotryotoxicosis was established on a dairy farm in 35-46-day-old calves due to the use of straw contaminated with Stachybotrys alternans. Studied were the epizootiology, the clinical picture, and chiefly the morphology of the disease. A characteristic clinical feature was the edema in the intermandibular space. Morphologically, there were numerous hemorrhages in the subcutaneous tissue, skeletal muscles, abomasal and intestinal mucosa, kidney cortex, and urinary bladder as well as ulcerous and erosive colitis, edematized mesenterial lymph nodes and occasionally catarrhal and necrotic stomatitis, icterus, and perirenal edema. Contrary to the gross lesion picture known there were no changes in the rumen, reticulum, and omasum which were not sufficiently developed during that period. Histologically, there were degenerative nephrosis, focal hemorrhagic glomerulonephritis (occasionally coupled with bacterial embolization and dystrophic calcification of the kidneys), granular degeneration of the liver and heart, hemorrhages and edema of the lungs, and edema, hyperemia, and thrombi in the brain.

Animals↗
PubMed1981

[Method of obtaining concentrated and purified chlamydial suspensions].

A method was worked out to obtain concentrated and purified chlamydial suspensions. Used were differential centrifugation and super-centrifugation, gel filtration on sepharose, and ultracentrifugation on saccharose substrate. The new method was successfully employed in electron microscopic, immunologic, and immunofluorescence investigations. As a result of its use in electron microscopy studies were carried out on the morphology of the purified chlamydial particles in ultra thin sections and negatively contrasting preparations. Immunologic studies led to the production of high-titer hyperimmune sera from guinea pigs. Such native sera were successfully used to obtain high-titer fluorescent sera.

Animals↗
PubMed1980

[Passive hemagglutination reaction with adenovirus antigen].

In a passive hemagglutination reaction (micromethod for detecting IBP antibodies) were used 4 types of cellularly cultivated, group specific antigens from a cattle adenovirus, serotype 1. The most appropriate for the reaction proved to be the antigen obtained by a complete destruction of the infected cells and deduction of the soluble viral hexen components. The production of th antibodies does not require a special equipment. A high-titre antigen is obtained, which can be well loaded passively on tanninized sheep erythrocytes. A much higher sensitivity of passive hemagglutination reaction was obtained in comparison with virus neutralizing reaction and immunodiffusion reaction. Therefore, for mass serological investigations if serums from calves suffering from bronchial pneumonia, a much larger quantity of seroreagents are detected, which remain undetected if immunodiffusion reaction is applied. Prospects are discussed for the implementation of this micromethod for mass serological investigations in detecting the dissemination of adenoviral infections with cattle.

Adenoviridae↗
PubMed1980

[Isolation of the IBR virus antigen for immunodiffusion].

A number of physicochemical and immunoelectrophoretic investigations as well as tests were carried out for the standardization of an antigen for immunodiffusion prepared from an IBR virus. The antigen showed strict specificity and maximum activity at a concentration forming a 7.5-8.0 mm diffusion disc in a radical immunodiffusion. It is made up of two antigenic components and shows a pronounced lability. The antigen reacts more intensely with immunoglobulins of the IgM type but is also active with regard to IgG. The antigen makes positive all serums with virus neutralizing antibodies having a titre of 1:16 and above. It is susceptible to standardization and shows stability as regards preservation in a lyophilized state.

Antigens, Viral↗
PubMed1980

[Immunofluorescent diagnosis of bovine adenoviruses].

By applying the direct immunofluorescent method, a study was carried out on the appearance and accumulation of adenoviral antigen in cattle, in infected cellular cultures from the testes of calves and in epithelial cell obtained by smearing with nasal mucosa and conjunctiva of experimentally infected and spontaneously taken ill with adenoviral infection calves. A specific conjugate was obtained by the writers of the present study. In the cultures from calf testes, the earliest viral antigen was proved 36 hours after the infection in the form of a finely granulated nuclear fluorescence with a yellow-green colour. The highest quantity of fluorescent cells was observed after 72 hours. A specific nuclear fluorescence was observed as early as on the sixth day after the infection in the nasal mucosa of experimentally infected calves. An adenoviral antigen was detected on the tenth day in 30% of the cells, and in separate fields of vision the number of fluorescent cells predominated over the negative ones. During the next days the intensity of the nuclear fluorescence diminished, whereas in the cells obtained by smearing on the eighteenth and twenty fourth days of the infection of calves, it was no longer observed. No adenoviral antigen was proved in the first preparations produced from spontaneously ill calves. Such was proved after a second taking of nasal and conjunctival samples six days later. A conclusion was drawn that the immunofluorescent direct method allows the identification of an adenoviral antigen in cells of the epithelium of the upper respiratory routes during the first days of calves infected with adenoviruses.

Adenoviridae↗
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↗
PubMed1979

[Serological diagnosis of IBR. Comparative studies of cattle sera in the virus neurtalization and passive hemagglutination reactions].

Three hundred eighty six cattle serums were simultaneously investigated by virus neutralizing (VN) and passive hemagglutination (PSH) reactions. Results obtained by the two methods coincided in 94% of the sermums studied and all serums with VN antibodies had also antibodies which can be established by the PSH reaction. About 6% of the positive reagents for PSH reaction were negative for the VN reaction. These were serums containing early antibodies (IgM) or low-titer antibodies of the IgG class, and were subtreshold for the VN reaction. The antibody titers determined by the PSH reaction were 7 to 10 times higher than these determined by the VN reaction, while their mean titer in serums with minimum VN index 1.0 was 1:23. The conclusion is drawn that PSH can be used as an independent serological test.

Animals↗
PubMed1979

[Serological diagnosis of IBR. Passive hemagglutination microreaction].

The preparation and standardization of the ingredients for PHA is described in detail. Formalin treated erythrocites in a 10% concentration treated with 1:20 000 tannin were used. The antigen concentrated by ultracentrifugation properly sensibilizes the erythrocites and their titer does not change in case of its dilution up to 1:8. The non-concentrated virus antigen has a low covering potential only if it is either not diluted, or in a 1:2 dilution and sensibilizes the erythrocites to a lesser extent. The great advantage of the use of concentrated antigen is that it equalizes antigens obtained from various lots. The optimal time for loading by erythrocites is 1 h, and a longer sensibilization has no influence on the effect of loading. It was proven that the sensibilization of formalin treated erythrocites allows long storage of the produced antigen. The tannin treated formalinized erythrocites can be stored up to 20 days without any change in their ability to be antigen covered, while the sensibilized erythrocites are not changed for 6 days and up to the 30th day their titer is twice lower, but this is of no practical importance.

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↗