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Biomedical subjects

A Pospischil

Publications and source records attributed to A Pospischil.

At least 73 records · Page 4Linked to original sources
PubMed1995

Panleukopenia-like syndrome of FeLV caused by co-infection with FeLV and feline panleukopenia virus.

To study the effect of interferon on feline leukemia virus (FeLV) infection, 30 specific pathogen free (SPF) cats were infected with the apathogenic FeLV A Glasgow. Unexpectedly, between 5 and 8 weeks after FeLV infection, all 19 cats with persistent FeLV infection but not the FeLV-negative cats died from a panleukopenia-like syndrome. No feline panleukopenia virus (FPLV) antigen was found in feces by latex agglutination, enzyme-linked immunosorbent assay (ELISA) or immunoelectron microscopy. No enteropathogenic bacteria were found. Histopathology revealed changes resembling those of FPLV infection such as destruction of crypts and pancytopenia of bone marrow. Neither clinical signs nor seroconversion to FPLV could be induced by transmitting intestinal extracts to two SPF cats. However, FPLV antigen was demonstrated by immunofluorescence assay in intestinal cryostat sections of diseased animals. FPLV could also be demonstrated in intestinal extracts by immunoelectron microscopy, by latex agglutination and ELISA after anti-FPLV antibodies were removed from immune-complexed FPLV by ultracentrifugation over a CsCl gradient at pH 2.0. From these experiments it was concluded that the panleukopenia-like syndrome of FeLV may not be caused by FeLV alone but at least in some cases by co-infection with FeLV and FPLV. In addition, some form of 'cooperation' between FeLV and FPLV must be postulated because neither virus alone induced symptoms.

Animals↗
PubMed1995

Diagnosis of fetal infection with porcine parvovirus by in situ hybridization.

In situ hybridization (ISH) for the diagnosis of fetal infection with porcine parvovirus (PPV) was compared with immune electron microscopy (IEM) and serology by immunofluorescence (IF) for its sensitivity and its applicability in a routine diagnostic laboratory. The technique was applied to the examination of sections of formalin-fixed paraffin-embedded tissues from 68 fetuses. Fifty-three of these fetuses were diagnosed serologically since they had a crown rump length of more than 17 cm, i.e. they were mature enough to mount a humoral immune response; 38 were positive and 15 negative. Eleven out of 15 smaller fetuses examined for the presence of viral antigen by immune electron microscopy (IEM) were positive and 4 were negative. Heart and lung were found to be the most suitable organs for in situ hybridization. In situ hybridization yielded a positive result in 8 of the 11 IEM positive fetuses and in 33 of the 38 serologically positive fetuses. No signal was detected in any of the 4 IEM or the 13 serologically negative fetuses. Expenses for IEM were estimated to be 179% of the expenses for ISH. Expenses for serology by IF on the other hand were 67% of the expenses for ISH. From this it was concluded that the most efficient way to diagnose a fetal infection with PPV was serology by IF, if possible with samples from several fetuses and that the other techniques, IEM or ISH, ought to be reserved for those cases where no immunocompetent fetuses were available for diagnosis.

Animals↗
PubMed1995

An immunohistochemical study of the distribution of border disease virus in persistently infected sheep.

Three seronegative sheep persistently infected with Border disease virus and six seropositive, non-viraemic sheep were examined for the cellular distribution of the agent. These animals originated from a closed flock which had been kept in an isolation facility for 5 years. They were killed and immediately necropsied. There were no gross abnormalities other than reduced body weight of the persistently infected sheep. Two samples of each major organ were collected. The first sample was fixed by immersion in formalin and processed for histological examination, which showed no lesions unequivocally attributable to the viral infection. The second sample was snap-frozen for immunohistochemical examination. This revealed viral antigen in all organs of the persistently infected, but in none of the seropositive animals. The infected cells included smooth muscle cells of hollow organs and blood vessels, epithelial cells of the alimentary tract and urogenital organs, lymphocytes in lymphoid organs, endocrine cells, neurons and glial cell.

Animals↗
PubMed1995

[Malignant melanoma in two cats].

Malignant melanomas with extensive metastasis in various organs were diagnosed in a 8-year-old European shorthair cat and a 10-year-old Persian cat. The primary tumor in the European shorthair cat was located within the eye. The clinical progress, gross pathology and histology are outlined. The possibility of an increase of melanomas in combination with FIV- or FeLV-infections is discussed.

Animals↗
PubMed1995

[Immunohistochemical determination of Chlamydia psittaci/pecorum and C.trachomatis in the piglet gut].

The jejunum, ileum, caecum and colon of 200 piglets were investigated immunohistochemically for the presence of Chlamydia psittaci and C. trachomatis using a vitelline IgY. Positive samples were later labelled using a commercial C. trachomatis polyclonal antiserum. Chlamydia were present in 33 (16.4%) of the animals, and 30 out of 33 were labelled by C. trachomatis polyclonal antiserum. Inclusions occurred predominantly (67%) in the large intestine. The serological results (CFT, ELISA) did not correlate well with immunohistochemical labelling in the gut. The incidence of Chlamydia rose from 6.9% in animals up to 4 weeks, to 41.8% in those over 4 weeks of age. A correlation between chlamydia and enteric disease was not obvious. Besides chlamydia, most of the diseased animals harboured other additional agents. In conclusion, intestinal chlamydiae in piglets, predominantly C. trachomatis, exist in Switzerland, although their pathogenic potential seems to be low.

Animals↗
PubMed1994

Access to the abomasum of sheep via a rumen fistula for follow-up studies during trichostrongylid infections.

A technique is described for the examination of the abomasum of adult sheep via a rumen fistula. The size of the fistula allowed a manual exploration of the rumen which was necessary to achieve an access to the abomasum. In four adult sheep, two of them infected with Haemonchus contortus, fibreoptic endoscopy was used to investigate the abomasal mucosa macroscopically as well as histopathologically and ultrastructurally by means of mucosal biopsy specimen. The acidity of the abomasal contents was measured directly by introducing an electrode into the abomasum or indirectly in abomasal fluid which was obtained via a stomach catheter through the rumen fistula. The measured values in all four sheep ranged between pH2 and 4. The fibreoptic examination of the abomasum did not influence the plasma pepsinogen and gastrin levels. The possibility of combining histological, serological and coprological data in follow-up studies on the pathophysiology of trichostrongylid infections in the abomasum of individual sheep seems to be useful for the investigation of primary and secondary infections and may contribute to a reduction of the number of experimental animals in such studies.

Abomasum↗
PubMed1994

[Diarrheal diseases in 1 to 4 week old suckling piglets from problem herds: microbial spectrum, histology, enzyme histochemistry].

Postmortem investigation was performed on 54 scouring (soon after onset of diarrhea) and 23 healthy suckling piglets. The animals were 1 to 4 weeks of age and were collected from 27 herds. In 21 herds diarrhea had been observed for a long time in piglets in this age group. Coccidia were found in 34 piglets, rotavirus in 2, cryptosporidia in 2, enterotoxigenic E. coli in 6, attaching and effacing E. coli in 1, Cl. perfringens type C in 1, Campylobacter coli in 53 and C. hyointestinalis in 8 piglets. Some of these microorganisms were isolated from healthy piglets as well. TGE- and PED-Virus antigen, as well as Salmonella were not recovered from any of the pigs. Results of the histopathological and enzyme histochemical investigations were in agreement with data from the literature. They confirmed and emphasized the role of coccidia as enteropathogenic agents in the animals examined. On the other hand evidence was shown, that C. coli is non-pathogenic. The role of C. hyointestinalis could not be fully elucidated. At least one sort of enteropathogenic agent was detected in about 68% (n = 37) of the scouring pigs or was present in 81% (n = 17) of the herds, respectively.

Animals↗
PubMed1993

Bacteriological, serological, histological and immunohistochemical findings in laying hens with naturally acquired Salmonella enteritidis phage type 4 infection.

Salmonella enteritidis phage type 4 was isolated from the reproductive tract of 10 (27 per cent) of 37 laying hens from three small flocks with a naturally acquired infection. The rapid slide agglutination test with Salmonella pullorum-antigen was positive in 24 (64.9 per cent) of the 37 hens including the six hens in which the ovary was colonised and the 10 in which the oviduct was colonised. By immunohistochemical labelling S enteritidis was demonstrated in seven of eight culture-positive hens on the surface of and within the epithelial cells in the lumen and in the tuberine glands of the oviduct.

Agglutination Tests↗
PubMed1993

[The infectious causes of abortion and stillbirth in swine in Switzerland].

Fetuses and placentae of 171 cases of porcine abortion, stillbirth and mummification were examined for pathological lesions, bacterial infections and PPV (porcine parvovirus) infection. Furthermore IgG (immunoglobulin G) levels were determined in fetal body fluids. Selected maternal sera were tested for antibodies against Leptospira, Aujeszky's disease and hog cholera. PPV infection was diagnosed in 29.2% of all cases. Bacterial abortion was diagnosed in 8.2%. Indications for an infectious agent were demonstrated in about 10% of the cases. The etiology of the abortion could not be identified in 52%. Inflammatory alterations in association with the isolation of bacteria consisted of neutrophilic infiltration and necrosis and were of particular value to differentiate bacterial contamination from infection. Infiltrations of mononuclear leucocytes in brain, leptomeninx, kidney or myocard were observed in about 50% of the fetuses with PPV infection. IgG levels were consistently elevated in fetuses serologically positive for PPV, but also in two fetuses, where no infectious agent could be identified.

Abortion, Veterinary↗
PubMed1993

[The postnatal development of porcine purine catabolism and the effect of the environmental temperature on turnover].

Experiments in piglets indicate that the catabolic metabolism of purines is only developed during the first 4 weeks of life. During this time the catalytic activity of uricase in liver homogenates is increased about 5.5 fold (p < 0.01). The counts of uricase-carrying peroxisomes and cores are increased to a similar degree (p < 0.01). In the same time the catalytic activity of cytosolic xanthine oxidase is elevated about 4.6 fold (p < 0.01), mainly in the second and third week. In blood plasma uric acid is decreased from 19 to 12 molar % during weeks 1 to 4, hypoxanthine, xanthine and allantoin remain relatively constant. In urine xanthine and uric acid are decreased, hypoxanthine and allantoin are increased. At the age of 2-3 days a decrease of ambient temperature from 32 to 20 degrees C caused an increase of the plasma pool (p < 0.01) and turnover (p < 0.05) of uric acid. Pool size and turnover of hypoxanthine are only slightly elevated. The results are discussed in view of the slow development of hepatic enzymes, the increase of uric acid pool at lowered ambient temperature and causal events leading to urate nephropathia.

Animals↗
PubMed1992

Specific diagnosis of parvovirus enteritis in dogs and cats by in situ hybridization.

In a retrospective study, the fixed intestines of 10 dogs and 10 cats with intestinal lesions characteristic of parvovirus infection were assayed for the presence of parvovirus by in situ hybridization and immunohistochemistry. Parvoviral nucleic acid was localized by in situ hybridization in intestinal tissue in all 10 dogs and in nine of the 10 cats, whereas antigen was detected only in seven of 10 canine and eight of 10 feline intestines by immunohistochemistry. We conclude that an aetiological diagnosis can be established with a high degree of certainty by routine histology. Demonstration of the infectious agent by in situ hybridization, however, proves to be a valuable specific tool which allows an exact cellular localization of parvovirus in formalin-fixed, paraffin wax-embedded tissue sections.

Animals↗
PubMed1992

Electron microscopy of the endometrium of camels in normal and some diseased conditions.

Ultrastructure of the camel's endometrium in normal and diseased conditions, was studied using the electron microscope. The samples were obtained from 6 normal uteri and 10 uteri with inflammatory lesions. Three ovaries of the latter 10 uteri showed ovarian cysts. All the animals were non-pregnant. No cyclic changes were taken in consideration because the camel is an induced ovulator animal. The surface and the glandular epithelium of the normal uteri consisted of one layer of tall columnar cells, resting on an undulating membrane. The free borders of cells showed microvilli, motile cilia and zeiotic blebs. Desmosomes and gap junctions were seen as means of connections between the neighboring cells. The nuclei were large, oval and situated in the lower half of the cells. Two types of mitochondria were seen. One type was small, rounded and dilated, and the other was large and elongated. Many lipid droplets and scanty glycogen granules were common findings in the normal cells. Granulated bodies similar to those described in the epithelium of the human uterus and containing acid phosphatase were found. Many other cytoplasmic organelles and granules were seen. The endometrial stroma consisted mainly of stromal cells of irregular shape, and collagen fibres. The collagen fibres were present in amounts larger than many other species. In the diseased uteri, the changes in the epithelium consisted mainly of hyperplasia of the cells and marked increase of all cytoplasmic inclusions and vacuoles. There was also marked increase in the number of the crossing lymphocytes through the epithelial layer. The collagen fibres of the stroma increased in amount and the stromal cells became similar in shape to the fibroblasts. A large number of mast cells as well as other types of inflammatory cells infiltrated the stroma. Non-specific bacterial infections were detected on bacteriological examination of the inflamed uteri. Neither bacteria nor other microbial agents could be seen ultrastructurally. In an uterus associated with ovarian cysts, the microvilli of its epithelium showed marked changes in their shape and length.

Animals↗
PubMed1992

[Causes of prenatal foal loss in Switzerland].

In Switzerland during the foaling season 1988 and 1989 the cause of abortion in 60 foals was investigated. Special attention was paid to infections with equine herpesvirus 1 (EHV 1). Diagnosis were based on post-mortem, histopathological, bacteriological and immunofluorescence investigation. The results confirm data from other countries, that EHV 1 is the most prevalent viral (20%) cause of abortion, followed by various bacterial agents (12%). Other causes were umbilical torsion, twin pregnancy and malformations. In 18% of the cases the investigation of fetuses did not give any results as to the cause of abortion, suggesting maternal factors as only cause of abortion.

Abortion, Veterinary↗
PubMed1992

[Infections with enteropathogenic Escherichia coli (EPEC) in cattle. 1. Comparison of different animal models and a cell culture system for the establishment of a detection system for "attaching and effacing" (AE) lesions].

In several animals species, enteropathogenic Escherichia coli (EPEC) were described as agents causing diarrhea. The histopathogenic pattern of EPEC is due to a typical adherence to enterocytes, called "attaching and effacing" (AE). This lesions are characterized by the formation of pedestals, cups and a marked loss of microvilli on enterocytes. In view of using an "in vitro system" (HeLa-cell culture) to test the adherence of EPEC, we first tested bovine EPEC in several laboratory animals. Various strains of mice, one day chicks (peroral) and a three day old calf (ligated intestinal loops) were inoculated with a bovine pathogenic EPEC (S 102-9). The adherence of EPEC "in vivo" was histologically, electron microscopically and bacteriologically investigated and compared to adherence to HeLa cell cultures. AE-lesions were found on calf enterocytes as well as on HeLa-cells, no lesions were seen in mice and chicks. The ligated intestinal loop test seems to be a useful model to compare "in vivo" to "in vitro" adherence.

Animals↗
PubMed1991

Immunohistochemical detection of chlamydiae in formalin-fixed tissue sections: comparison of a monoclonal antibody with yolk derived antibodies (IgY).

Immunohistological detection of chlamydiae in formalin-fixed and paraffin-embedded sections of various organs from several species is described. In a retrospective study, two antisera, a commercially available monoclonal murine antibody (IgMur) and vitelline immunoglobulins (IgY), extracted from the egg yolk of immunized hens, were compared and tested for their applicability under routine condition. Both antisera were applied to tissues from which chlamydiae had been isolated or in which the presence of chlamydiae had been suspected in specially stained sections. Antigen labelling was optimal with the monoclonal antibody. Vitelline immunoglobulins produced some unspecific reactions, especially in lung tissue sections. Because of the antigenic relationship between the vitelline antibodies and tissues of birds, IgY are not suitable for the detection of psittacosis on avian substrates, when using an indirect immunological method. Staining in other tissues e.g. intestine or placenta was of equal quality as that attained with monoclonal antibodies. Depending on the advantages and disadvantages in every individual case, one of the two antibodies may be chosen for further studies. Vitelline antibodies should be preferred with respect to animal welfare.

Animals↗