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Biomedical subjects

F Ehrensperger

Publications and source records attributed to F Ehrensperger.

At least 37 records · Page 2Linked to original sources
PubMed2000

Congenital hepatic fibrosis and cystic bile duct formation in Swiss Freiberger horses.

Congenital hepatic fibrosis with autosomal recessive or dominant inheritance has been described in humans, cats, piglets, and dogs. In horses, only two cases of congenital hepatic fibrosis have been previously reported. This retrospective study of records from the Institute for Animal Pathology, University of Berne, identified 30 foals with liver lesions compatible with congenital hepatic fibrosis. Anamnestic data revealed clinical signs of severe liver injury in most affected animals. Pathologic examination showed severely enlarged, firm livers with thin-walled cysts. Histologically, the livers showed diffuse porto-portal bridging fibrosis with many small, irregularly formed and sometimes cystic bile ducts. All foals belonged to the Swiss Freiberger breed. Pedigree analysis revealed that the diseased animals could be traced back to one stallion. These results strongly suggest that congenital hepatic fibrosis in Swiss Freiberger horses is a recessively inherited autosomal genetic defect.

Animals↗
PubMed1999

Intrauterine infection with bovine virus diarrhoea virus on alpine communal pastures in Switzerland.

This study involved 13 calves, one to 50 days of age, born to first calf heifers that had been pastured on one of seven alpine communal pastures in the canton of St. Gallen during the summer of 1995. Of a total of 993 cattle pastured, 61 were pregnant heifers that were negative for bovine virus diarrhoea (BVD) antigen and for BVD antibodies at the start of pasturing. Seroconversion occurred in 26 of these pregnant heifers during the pasture period. Blood samples and skin biopsy specimens of calves born to 13 of these were examined for BVD antigen by antigen-ELISA and by an immunohistochemical technique, respectively. Blood samples were positive for BVD antigen in four calves, questionable in one calf, negative in seven and missing in one prematurely born calf. The four calves that were positive for BVD antigen in the blood were also positive in skin biopsies. Of the seven calves with a negative or missing blood test, six had positive and two had negative skin samples. Based on the combined results of blood and skin testing, 11 of 13 calves were positive for BVD antigen. Of the 11 infected calves, six were normal at birth, four were smaller than normal and one was premature and weak and was euthanized on humane grounds. Of the four small calves, two developed diarrhoea and died within the first month of life. The two calves that were negative for BVD antigen were clinically normal. The results of this study not only demonstrate the occurrence of in-utero infection with BVD virus, but also stress the importance of alpine communal pasturing in the spread of BVD virus. Because the prevention of infection with BVD virus on communal pastures does not seem feasible, it is recommended that all calves born to cows from such pastures be tested for BVD antigen.

Animal Feed↗
PubMed1999

Lack of association between Borna disease virus infection and neurological disorders among HIV-infected individuals.

Viruses have been proposed as etiologic cofactors in the pathogenesis of HIV-related neurological disease. To investigate the etiologic potential of Borna disease virus (BDV) in these disorders, two populations were studied: (1) 27 prospectively identified patients with various neurological disorders were evaluated with BDV RT-PCR (CSF, PBMC), and BDV serology, and (2) a separate group of 25 retrospectively studied patients with AIDS dementia complex was evaluated using BDV serology only. A novel, BDV p40 gene RT-PCR assay was developed: conserved primers were used in a non-nested amplification, detecting less than 100 BDV RNA copies and all of nine wild-type, confirmed animal BDV infections. BDV seroprevalences were 12.5% and 8.0%, respectively, which are similar to the general HIV-infected population. None of the prospectively studied patients had detectable BDV RNA in their CSF or PBMC. Our findings do not support the hypothesis that BDV infections are responsible for HIV-related neurological disorders.

AIDS Dementia Complex↗
PubMed1999

[Borna disease in Switzerland and in the principality of Liechtenstein].

Borna disease (BD) is a rare immunopathological disorder of the central nervous system (CNS) caused by infection with Borna disease virus (BDV) and histologically characterized by mononuclear encephalomyelitis. BD primarily affects equines and sheep in well defined endemic areas of central Europe, but BDV infections have also been reported in other host species including humans, as well as in non endemic regions. In this paper recent data on the pathogenesis of BD are reviewed and the current situation in Switzerland and the Principality of Liechtenstein is summarized.

Animals↗
PubMed1998

Spontaneous Borna disease in sheep and horses: immunophenotyping of inflammatory cells and detection of MHC-I and MHC-II antigen expression in Borna encephalitis lesions.

Borna disease (BD) has been recognized as a virally induced T-cell dependent immunopathological disorder of the central nervous system (CNS), as shown by experimental infection of rats with Borna disease virus (BDV). In contrast to the rat model, little is known about the pathogenesis of spontaneous BD in sheep and horses. The present study describes the brain lesions of 12 ovine and 11 equine cases of naturally occurring BD. A set of monoclonal and polyclonal antibodies was used in order to determine the cells operative in encephalitic lesions and to detect expression of MHC-I and MHC-II products in the brains of affected animals. In all cases investigated, a reaction pattern similar to that reported for the acute phase of BD in experimentally infected rats was noted. In brief, the majority of inflammatory cells in perivascular infiltrates (PVI) as well as parenchymal and meningeal infiltrates were CD3 +. CD4 + cells outnumbered CD8 + cells in PVI as well as in the parenchyma. Macrophages (defined by lysozyme immunoreactivity) were seen less often and B-cells or plasma cells (cells positive for lambda or kappa light chains) were demonstrated at lower numbers. TCR-1 + cells were found on very rare occasions in PVI of some sheep. MHC-I and MHC-II products were constantly expressed on inflammatory cells but inconsistently on astrocytes and neurons. Neuronal degeneration was not a major feature.

Animals↗
PubMed1998

Lesion of the area postrema/nucleus of the solitary tract (AP/NTS) attenuates the anorectic effects of amylin and calcitonin gene-related peptide (CGRP) in rats.

The area postrema/nucleus of the solitary tract (AP/NTS) region plays an important role in the control of food intake since it receives peripheral satiety signals via splanchnic and vagal afferents. Due to the lack of the blood brain barrier in this region, blood borne signals can directly be monitored in the AP/NTS. Furthermore, receptors for anorectic peptides such as amylin or calcitonin gene-related peptide (CGRP) have been found in the AP/NTS. It was therefore the aim of the present study to investigate the role of the AP/NTS region in mediating the anorectic effects of these peptides. Thermal ablation of the AP/NTS resulted in a significant reduction of the anorectic effects of IP injected amylin (5 microg/kg) and CGRP (5 microg/kg) in food deprived rats. The anorectic actions of CCK and BBS were also reduced by the AP/NTS lesion which agrees with previous studies. We conclude that the AP/NTS region is an important brain site for mediating the anorectic effects of amylin and CGRP. It remains to be clarified whether this effect is due to amylin and CGRP action on receptors within the AP/NTS region or peripheral receptors on afferent nerves projecting to the AP/NTS.

Afferent Pathways↗
PubMed1998

Epidemiology of bovine virus diarrhoea in cattle on communal alpine pastures in Switzerland.

The goal of this study was to determine the influence of communal pasturing on the spread of bovine virus diarrhoea (BVD). The investigation involved 990 Swiss Braunvieh cattle from 149 different owners on seven communal pastures in the Swiss Alps. Prior to pasturing, blood samples were collected from all animals for examination for BVD antigen and antibodies. Serological examinations were also performed during and after pasturing to determine possible increases in seroprevalence and to determine whether seroprevalence was different on pastures with and without persistently infected cattle. At the start of pasturing, nine (0.9%) animals were persistently viraemic. On three alpine pastures, no persistently viraemic animals were detected. The prevalence of persistently infected cattle on the remaining four pastures varied from 0.3 to 3.9%. Of the 990 animals tested at the start of pasturing, 632 (63.3%) were seropositive. Seroprevalence differed among pastures and varied from 21.8 to 85.9%. During the summer, seroprevalence increased on all pastures surveyed, and at the end of the pasture season, 778 (80.1%) of the 971 cattle that were examined twice were seropositive. The incidence of seroconversion was significantly higher on pastures with persistently infected cattle compared with those without; it ranged from 32.7 to 100.0% in the former and from 6.0 to 22.2 in the latter. The results of this study suggest that communal alpine pasturing does play a role in the spread of BVD. The extent of this role depends on the presence of persistently infected animals.

Animal Feed↗
PubMed1998

Borna disease in a dog with lethal meningoencephalitis.

A dog was euthanatized because of progressive neurological signs. Histologically, a nonsuppurative meningoencephalitis was found. By immunohistochemistry, in situ hybridization, and nested PCR procedures, Borna disease virus (BDV) antigen and BDV-specific RNA were demonstrated in brain tissues of the dog. The nucleotide sequence of the PCR product showed 94 to 98% homology to published BDV sequences. This is the first description of Borna disease in a dog.

Animals↗
PubMed1998

[Pestivirus as causative agent of abortion and perinatal mortality in cattle and sheep in Switzerland].

The causal involvement of bovine viral diarrhoea virus (BVDV) and border disease virus (BDV) infection in bovine and ovine abortion and perinatal mortality remain unclear. From 1992 until 1994, 213 bovine and 31 ovine foetuses as well as 36 calves and 25 lambs which had died perinatally were investigated. Tissue samples were tested for the presence of pestiviruses and serum or fluid from the body cavities were analysed for the presence of pestivirus antibodies. Detection of pestiviruses was performed by (i) cell culture isolation, (ii) antigen ELISA and (iii) immunohistochemical staining for viral antigen. For antibody-testing an indirect ELISA was used. In nine bovine foetuses and in two calves BVDV was isolated. Pestiviruses, most likely BDV were detected in one ovine foetus and three lambs. In 6% of the bovine and 11% of the ovine foetuses anti-pestivirus antibodies were detected. However, clinical features and history of bovine cases did not show a correlation with the diagnostic results, In contrast, the presence of central nervous system signs in neonatal lambs and the detection of BDV was correlated.

Abortion, Veterinary↗
PubMed1998

[182 offspring of cows with bovine spongiform encephalopathy (BSE) in Switzerland. 1. Clinical findings].

This study involved 182 calves, heifers and cows that were the first generation progeny of cows with bovine spongiform encephalopathy (BSE). All animals underwent clinical and neurological examinations. Blood, milk, urine, ruminal fluid and cerebrospinal fluid samples were examined. Each cow underwent a specific examination for BSE which included assessment of behaviour, sensitivity and locomotion. This examination was performed twice, and there was very good agreement between the results. The most common symptom was nervousness (14 animals). In the first examination, 68 animals were mildly to moderately sensitive to touching of the head, 44 animals were hypersensitive to a halogen light and 35 animals were hypersensitive to a camera flash. Twenty-four animals reacted by kicking when the hindlimbs were touched with a broom. None of the animals had disturbances in locomotion. Based on the interpretation of all findings and the comparison of the results of the first and second examinations, 173 animals were diagnosed as free of BSE. In 9 animals, the disease could not be ruled out; however, it could not be confirmed in any of them. Histological and immunohistochemical examinations of the brain of all animals were negative for BSE (see Part 2 of the study for details). The results of this study indicate that abnormal clinical findings may occur in clinically healthy cattle. However, none of the progeny of cows with BSE exhibited clinical signs typical of BSE, such as disturbances in behaviour; sensitivity and locomotion.

Animals↗
PubMed1998

[182 offspring of cows with bovine spongiform encephalopathy (BSE) in Switzerland. 2. Epidemiology and pathological findings].

In order to detect lesions of a spongiform encephalopathy and/or accumulation of the protease resistant prion protein (PrPres), 182 offspring of cows affected with BSE were examined neuropathological and immunohistochemically. Neither spongiform encephalopathy nor PrPres accumulation were found. In seven animals other neuropathological lesions were seen, significant ones in three. Because of the small risk of exposure to contaminated feed in these animals, nearly all of which were born after the introduction of the protein feed ban for ruminants, the occurrence of spongiform encephalopathy in this series of BSE offspring would be suggestive of maternal transmission. However, the value of the study in this respect is quite limited. Only half of the animals were old enough to develop clinical and pathological evidence of the disease. If a maternal effect on the risk for the offspring is only to be expected during the last 6 months of the incubation of the dam as suggested by British investigations, only few animals in this study would fulfil the requirement of having been born during this critical period. Since it cannot be entirely excluded that the BSE agent transiently invades extraneural tissues in the early stages of infection, the above mentioned restriction to the final 6 months of the incubation time of the dam would not necessarily be applicable to all situations. We concluded that this study supports previous observations according to which maternal transmission of BSE is at best a rare event.

Animals↗
PubMed1997

Prion (PrPSc)-specific epitope defined by a monoclonal antibody.

Prions are infectious particles causing transmissible spongiform encephalopathies (TSEs). They consist, at least in part, of an isoform (PrPSc) of the ubiquitous cellular prion protein (PrPC). Conformational differences between PrPC and PrPSc are evident from increased beta-sheet content and protease resistance in PrPSc. Here we describe a monoclonal antibody, 15B3, that can discriminate between the normal and disease-specific forms of PrP. Such an antibody has been long sought as it should be invaluable for characterizing the infectious particle as well as for diagnosis of TSEs such as bovine spongiform encephalopathy (BSE) or Creutzfeldt-Jakob disease (CJD) in humans. 15B3 specifically precipitates bovine, murine or human PrPSc, but not PrPC, suggesting that it recognizes an epitope common to prions from different species. Using immobilized synthetic peptides, we mapped three polypeptide segments in PrP as the 15B3 epitope. In the NMR structure of recombinant mouse PrP, segments 2 and 3 of the 15B3 epitope are near neighbours in space, and segment 1 is located in a different part of the molecule. We discuss models for the PrPSc-specific epitope that ensure close spatial proximity of all three 15B3 segments, either by intermolecular contacts in oligomeric forms of the prion protein or by intramolecular rearrangement.

Amino Acid Sequence↗
PubMed1997

Immunohistochemical diagnosis of pestivirus infection associated with bovine and ovine abortion and perinatal death.

OBJECTIVE: To establish a reliable, rapid, economical method for detection of pestivirus infection in bovine and ovine fetuses and to examine participation of these viruses in abortions and neonatal mortality. ANIMALS: 213 bovine and 31 ovine fetuses, as well as 36 newborn calves and 25 lambs, which had died within 3 days after birth, were tested for bovine viral diarrhea virus (BVDV) and border disease virus by use of different methods. PROCEDURE: Detection of BVDV in fetuses was performed by immunohistochemical methods, using a panel of monoclonal antibodies against pestivirus antigens on cryostat and paraffin sections and by virus isolation in cell culture; in some instances, an antigencapture ELISA was performed. Results of the various methods were compared. RESULTS: Sensitivity of BVDV detection by immunohistochemical methods and virus isolation in cell culture was equal; however, it decreased in association with autolysis. In autolytic fetuses, use of formalin-fixed, paraffin-embedded brain sections was the most favorable method. Antigen detection by ELISA was less sensitive. CONCLUSIONS: Immunohistochemical analysis of cryostat sections of brain, skin, thyroid gland, abomasum, and placenta is a rapid, sensitive method for detecting pestiviruses in fetuses. In the presence of advanced autolysis, this method used on formalin-fixed, paraffin-embedded brain sections is recommended over the other described methods.

Abortion, Veterinary↗
PubMed1996

[Congenital bile duct cysts and liver fibrosis in a foal].

A three-week-old foal was submitted to the clinic because of a minor traumatic injury at the lower jaw. At admission the foal exhibited diarrhea, a distended abdomen and reduced general condition. These findings could not be associated with the injury. On abdominal radiography decreased abdominal detail and a dorsocaudal displacement of the intestine was present. Ultrasonographically multiple fluid-filled cystic structures of several centimeters in diameter were identified. These cystic structures appeared to be associated with the liver. At laparotomy and at necropsy the liver was markedly enlarged and firm and had large, thin-walled, with a bile-like fluid filled cysts, 4-20 centimeters in diameter. Histological lesions were characterized by proliferation of small bile ducts and of interlobular connective tissue as well as focal subacute cholangitis. Gross and histological findings were considered to be consistent with congenital polycystic liver disease and fibrosis with ascending cholangitis.

Animals↗
PubMed1996

[Immunohistology as a reliable and efficient method for the diagnosis of BVDV infections].

Persistent infection with the Bovine Viral Diarrhea/ Mucosal Disease Virus (BVDV) can be detected using immunohistological methods. The experiments show that the LSAB (Labeled Streptavidin Biotin) peroxidase method is suitable to detect the BVDV in cryostat sections of unfixed tissue. For the diagnostic work up in living animals, skin biopsies give reliable results. In dead animals, organs such as thyroid gland, skin, mucosa of the mouth, esophagus and abomasum are well suitable for immunohistological BVDV detection.

Animals↗