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Biomedical subjects

L Haas

Publications and source records attributed to L Haas.

At least 19 recordsLinked to original sources
PubMed2006

[Genetic typing of classical swine fever viruses--a review].

Classical swine fever (CSF) is a notifiable disease of domestic pigs and wild boar. It is caused by the highly contagious CSF virus and in its acute form the disease generally results in high morbidity and mortality. Due to the great economical impact an outbreak can cause to the pig industry it is one of the most important swine diseases worldwide. To limit the damage in the case of a new outbreak it is necessary to identify the virus as fast as possible. This information helps epidemiologists to trace the origin of the virus and to follow the virus spread. Genetic typing revealed that CSF virus genotypes, subgroups and types show a regional distribution making it an important tool for epidemiologists. Meanwhile, besides epidemiological data and nucleotide sequences from European isolates, information from isolates from South- and Central America, the Caribbean, Asia and recently from South Africa have become available. The data are stored in a database in the EU Reference Laboratory for CSF, accessible by the WWW (http://viro08.tiho-hanno ver.de). A new module was implemented that allows efficient automated genotyping.

Animals↗
PubMed2006

[Case report: equine arteritis virus (EAV) as the cause of abortion in alpacas?].

Here we report a case of a late abortion of a primiparous alpaca where genome fragments of the equine viral arteritis virus (EAV) could be detected in fetal tissues using reverse transcription polymerase chain reaction (RT-PCR). All five alpacas of the herd had virus neutralizing antibodies against EAV. EAV thus must be regarded as a potential agent for abortions in alpacas. Possible routes of introduction of the virus are discussed.

Abortion, Veterinary↗
PubMed2006

[Case report: Ectopia cordis in a German Holstein calf].

A case of ectopia cordis pectoralis was diagnosed in a black and white coloured German Holstein calf. The heart and pericard were displaced through a fissure in the breastbone. The heart was connected with the thoracic cavity by its large vessels. Besides of the ectopia cordis no other defects of the heart were noticed. The liver was deformed and many organs showed passive hyperaemia. The calf was well developed and died under birth. The lungs were not ventilated. The malformed calf was inbred on a bull used for artificial insemination with an inbreeding coefficient of 3.125%. The ectopia cordis probably resulted from the fissure of the breastbone.

Animals↗
PubMed2006

[Aphakia in a German Holstein calf].

Aphakia and further malformations of both eyes were diagnosed in a female German Holstein calf. Besides aphakia of the left eye, the calf exhibited microphthalmia, glaucoma and a hypoplastic uveoscleral tissue. Additional findings in the right eye were buphthalmus and glaucoma. Instead of aphakia, pathohistological and investigations revealed a very small (microphakia) and luxated lens. Neither the clinical nor the pathological examination revealed further malformations of other organs. A BVD infection could be excluded as cause for the ocular malformations observed. A deficiency or excess of vitamine A was unlikely because this would have also applied to all other calves born at the same time on the farm. An inbreeding coefficient of 3.168% for the malformed calf and the exclusion of environmental causes for these malformations of the eyes let us suppose a hereditary problem.

Animals↗
PubMed2005

Implementation of two-step vaccination in the control of bovine viral diarrhoea (BVD).

Bovine viral diarrhoea (BVD) control/eradication programmes based on the test and removal of persistently infected cattle without use of vaccination were first introduced by the Scandinavian countries in the early 1990s. Within the last 10 years the programmes have proven to be very successful and have served as a blueprint for several other European regions. However, in areas with high cattle densities, intense animal trade and high BVD prevalence this control approach is risky, because there is a high probability that herds, which have been cleared of persistently infected (PI) animals and have become partly or fully susceptible to reintroduction of the virus, will come in contact with a BVD virus (BVDV) infected animal. A combination of the test and removal strategy with subsequent systematic vaccination of cattle could overcome this problem. The goals of vaccination in such a programme is protection against reintroduction of BVDV into herds free from PI cattle and foetal protection of pregnant animals accidentally exposed to the virus. Two-step vaccination is based on the use of inactivated BVDV-1 vaccine for priming followed by a live attenuated vaccine booster 4 weeks later. The immune response elicited by such a vaccination scheme has proven to be long lasting and foetal infection after challenge with BVDV-1 and BVDV-2 was prevented in pregnant animals 5 months after vaccination. These findings suggest that the implementation of a two-step vaccination in the initial phase of control programmes in addition to test and removal of PI animals in areas with high cattle densities and endemic BVD is practical and efficacious.

Animals↗
PubMed2005

[Analysis of bulk milk samples using polymerase chain reaction: an additional tool for bovine viral diarrhea monitoring].

Programmes for the eradication and control of infections with bovine viral diarrhea virus (BVDV) concentrate on the identification and elimination of persistently infected (PI) animals. The identification of these animals is mainly based on the detection of viral antigen using ELISA techniques. Protocols detecting viral nucleic acid using RT-PCR have been described recently. Due to high costs the German model recommends screening of animals of 9 up to 36 months of age. Screening of bulk milk samples using RT-PCR technology would allow a system independent of age. The aim of the present study was to test whether bulk milk samples (1433 including max. 50 animals each) collected in four counties of Lower Saxony are suitable for a complementary identification of PI animals via RT-PCR. Thirty-one bulk milk samples derived from 27 dairy herds were BVDV positive, corresponding to 2.3 % of the herds analysed in this study. Two samples first scored doubtful. Follow up tests revealed lactating PI animals in most cases (18). In other cases the epidemiological status of the herd, i.e. high sero-prevalence and/or presence of PI animals among non-lactating cattle, suggested a transient infection detected in the first bulk milk sample. These results demonstrate that monitoring of lactating cattle of any age using RT-PCR is a very sensitive, economically effective additional method for the identification of PI animals.

Animals↗
PubMed2004

Rabies in red foxes (Vulpes vulpes) experimentally infected with European bat lyssavirus type 1.

The susceptibility of red foxes (Vulpes vulpes) to European bat lyssavirus type 1 (EBLV-1) infection was examined. Eight foxes were inoculated intramuscularly (i.m.) with 10(4.9) foci-forming units (FFU) (n = 4) and 10(5.1) FFU (n = 4) and observed for up to 90 days. All foxes showed manifestations of a neurologic disorder (e.g. seizures, myoclonus, agitation), starting as early as 5 days post-infection (p.i.). Subsequently, all animals showed improvement followed by one or more relapses. One fox was killed 3 days after it recovered, 26 days post-infection. Two other foxes were also killed 38 and 54 days post-infection after severe neurologic signs returned. All foxes developed a humoral immune response against EBLV-1 as determined in serum and brain tissues. However, no rabies virus antigen was detected in the brain, other tissues and secretions examined (e.g. salivary gland, saliva, tonsils, lungs) by using different standard diagnostic techniques [fluorescent antibody test, reverse transcription polymerase chain reaction (RT-PCR), rabies tissue culture inoculation test], with the exception of one fox in which EBLV-1 RNA was detected by RT-PCR in only the spinal cord. Brain tissues showed moderate to severe multifocal, mononuclear encephalomyelitis in the three foxes that were killed during the observation period, although no EBLV-1 virus was detectable in these tissues.

Animals↗
PubMed2002

Spontaneous human herpes virus type 1 infection in a chinchilla (Chinchilla lanigera f. dom.).

A 1-year-old male chinchilla with a 2-week history of conjunctivitis suffered subsequently from neurological signs comprising seizures, disorientation, recumbency and apathy. After 3 weeks of progressive central nervous disease the animal was killed in view of the poor prognosis. A non-suppurative meningitis and polioencephalitis with neuronal necrosis and intranuclear inclusion bodies were observed at necropsy and by light microscopy. The brain stem and cerebral cortices were most severely affected. Both eyes displayed ulcerative keratitis, uveitis, retinitis and retinal degeneration, and optical neuritis. Additionally, a purulent rhinitis with focal erosions, epithelial degeneration and intranuclear inclusion bodies was present. Ultrastructurally, herpes virus particles were detected in neurons of the brain. Immunohistochemistry with antisera specific for human herpes virus types 1 and 2 resulted in viral antigen labeling in neurons, glial cells and in neuronal processes. Viral antigen was found in the rhinencephalon, cerebral cortices, hippocampus, numerous nuclei of the brain stem, single foci in the cerebellum, and in a solitary erosive lesion of the right nasal vestibulum. Viral antigen was not detected in the eyes. The virus was isolated from the CNS, and nucleic acid sequence analysis of the glycoprotein B and the DNA polymerase revealed a sequence homology with human herpes virus type 1 of 99% and 100%, respectively. The clinical signs, the distribution of the lesions and the viral antigen suggest a primary ocular infection with subsequent spread to the CNS. Chinchillas are susceptible to human herpes virus 1 and may play a role as a temporary reservoir for human infections.

Animals↗
PubMed2002

Induction of apoptotic cellular death in lymphatic tissues of cattle experimentally infected with different strains of rinderpest virus.

The presence, type, and extent of cellular death in lymphatic tissues of cattle experimentally infected with rinderpest virus strains of different virulence was investigated morphologically. Cells with DNA strand breaks were identified in histological sections of palatine tonsil, spleen, and mesenteric and mandibular lymph nodes by the TUNEL (terminal desoxynucleotidyl transferase-mediated dUTP nick end labelling) assay. In addition, representative samples of lymphatic tissues were examined by transmission electron microscopy. The results indicated that cellular disassembly in lymphatic tissues was caused by both apoptosis and oncosis. Cells with DNA strand breaks were observed in follicular and parafollicular areas of lymphatic tissues and their numbers were determined. A significant correlation was found between the number of TUNEL-positive cells and viral virulence. These results suggest that, in addition to oncosis, apoptotic cellular death in lymphatic tissues contributes substantially to the pathogenesis of rinderpest.

Animals↗
PubMed2002

Intraoperative treatment strategy to reduce the incidence of postcardiopulmonary bypass atrial fibrillation.

PURPOSE: Postcardiopulmonary bypass atrial fibrillation remains a constant complication associated with coronary revascularization, the incidence of which occurs from 20% to 35%. Previous studies have addressed this problem in the postoperative setting utilizing pharmacological agents, but the results have been variable. The purpose of this study was to evaluate a novel intraoperative strategy to reduce the incidence of postcardiopulmonary bypass atrial fibrillation. We theorized that leukocyte depletion by filtration with the addition of aprotinin would reduce the systemic inflammatory effects of bypass and reduce the incidence of atrial fibrillation. METHODS: One hundred and twenty-two patients participated in this randomized study. Only isolated primary coronary revascularization procedures on cardiopulmonary bypass were included. The control group (n=55) received standard moderate hypothermic blood cardioplegia cardiopulmonary bypass. The treatment group (n=65) received similar cardiopulmonary bypass with the addition of strategic leukocyte depletion with Pall Biomedical Products (East Hills, NY) leukodepletion filters and full-dose aprotinin. RESULTS: The intraoperative addition of leukocyte depletion by filtration with aprotinin reduced the incidence of postcardiopulmonary bypass atrial fibrillation by 72%. The incidence.of atrial fibrillation in the control group was 27% (15 of 55). In contrast, the occurrence of atrial fibrillation in the treated group was only 7.6% (5 of 65) (p<0.025). CONCLUSIONS: This novel intraoperative treatment strategy of both mechanical (leukocyte filtration) and pharmacological (aprotinin) intervention appears to markedly reduce the incidence of postcardiopulmonary bypass atrial fibrillation. To our knowledge, this is the first study to combine these two treatment strategies. A previous study has noted a decline in atrial fibrillation with aprotinin in the animal model, but not to the extent observed in our study. The beneficial effects of the reduction of atrial fibrillation include reduced risk of emboli formation and the incidence of ischemia in the heart, lung and brain. In addition, a decrease in length of hospital stay, recovery time and overall cost occurred.

Aprotinin↗
PubMed2001

The hemagglutinin of canine distemper virus determines tropism and cytopathogenicity.

Canine distemper virus (CDV) and measles virus (MV) cause severe illnesses in their respective hosts. The viruses display a characteristic cytopathic effect by forming syncytia in susceptible cells. For CDV, the proficiency of syncytium formation varies among different strains and correlates with the degree of viral attenuation. In this study, we examined the determinants for the differential fusogenicity of the wild-type CDV isolate 5804Han89 (CDV(5804)), the small- and large-plaque-forming variants of the CDV vaccine strain Onderstepoort (CDV(OS) and CDV(OL), respectively), and the MV vaccine strain Edmonston B (MV(Edm)). The cotransfection of different combinations of fusion (F) and hemagglutinin (H) genes in Vero cells indicated that the H protein is the main determinant of fusion efficiency. To verify the significance of this observation in the viral context, a reverse genetic system to generate recombinant CDVs was established. This system is based on a plasmid containing the full-length antigenomic sequence of CDV(OS). The coding regions of the H proteins of all CDV strains and MV(Edm) were introduced into the CDV and MV genetic backgrounds, and recombinant viruses rCDV-H(5804), rCDV-H(OL), rCDV-H(Edm), rMV-H(5804), rMV-H(OL), and rMV-H(OS) were recovered. Thus, the H proteins of the two morbilliviruses are interchangeable and fully functional in a heterologous complex. This is in contrast with the glycoproteins of other members of the family Paramyxoviridae, which do not function efficiently with heterologous partners. The fusogenicity, growth characteristics, and tropism of the recombinant viruses were examined and compared with those of the parental strains. All these characteristics were found to be predominantly mediated by the H protein regardless of the viral backbone used.

Animals↗
PubMed2001

Classification and identification of Pfiesteria and Pfiesteria-like species.

Dinoflagellates can be classified both botanically and zoologically; however, they are typically put in the botanical division Pyrrhophyta. As a group they appear most related to the protistan ciliates and apicomplexans at the ultrastructure level. Within the Pyrrhophyta are both unarmored and armored forms of the dominant, motile flagellated stage. Unarmored dinoflagellates do not have thecal or wall plates arranged in specific series, whereas armored species have plates that vary in thickness but are specific in number and arrangement. In armored dinoflagellates, the plate pattern and tabulation is a diagnostic character at the family, subfamily, and even genus levels. In most cases, the molecular characterization of dinoflagellates confirms the taxonomy on the basis of external morphology; this has been demonstrated for several groups. Together, both genetic and morphological criteria are becoming increasingly important for the characterization, separation, and identification of dinoflagellates species. Pfiesteria and Pfiesteria-like species are thinly armored forms with motile dinospore stages characterized by their distinct plate formulae. Pfiesteria piscicida is the best-known member of the genus; however, there is at least one other species. Other genetically and morphologically related genera, now grouped under the common names of "Lucy," "Shepherd's crook," and cryptoperidiniopsoid, are being studied and described in separate works. All these other heterotrophic dinoflagellate groups, many of which are thought to be benign, co-occur in estuarine waters where Pfiesteria has been found.

Animals↗
PubMed2000

Epizootiological investigations of canine distemper virus in free-ranging carnivores from Germany.

Canine distemper virus (CDV) infects a broad range of carnivores. To assess whether wild carnivores may play a role in the epidemiology of CDV in domestic dogs in Germany, the seroprevalence of CDV was determined. In sera from red foxes (30 of 591 (5%)) and stone martens (2 of 10 (20%)) antiviral antibodies were detected using a neutralization assay, whereas sera of raccoons, two mink, one pine marten and one raccoon dog were negative. In foxes, there was a significantly higher prevalence in urban and suburban compared to rural regions. When testing lung and spleen tissue samples (fox, badger, stone marten, polecat, raccoon dog) 13 of 253 (5.1%) foxes, 2 of 13 (15.4%) stone martens and 2 of 6 (33%) badgers were virus positive using RT-PCR. Phylogenetic analysis based on partial sequences of the F gene revealed a distinct relatedness to canine CDV isolates. Together, the data support the concept of transmission of CDV between domestic dogs and wild carnivores.

Amino Acid Sequence↗
PubMed2000

Complementary and alternative medicine and gastrointestinal diseases.

Complementary and alternative medicine (CAM) is becoming increasingly utilized as a form of health care, with recent studies suggesting that over 40% of Americans use some form of CAM. This has major financial implications for the health care industry. Traditional physicians frequently are unaware of CAM use by their patients, and there are potential interactions between CAM and traditional forms of medical therapy. Many of the medicinal CAM agents have been used for their postulated anti-inflammatory and/or antifibrotic effects. CAM is especially frequently used in patients with chronic diseases. This review discusses CAM use in three types of chronic gastrointestinal diseases--liver disease, irritable bowel syndrome and dyspepsia, and inflammatory bowel disease.

Journal Article↗
PubMed1999

Analysis of the H gene, the central untranslated region and the proximal coding part of the F gene of wild-type and vaccine canine distemper viruses.

This paper summarizes the results of the genetic analysis of several parts of the genome of canine distemper virus (CDV) field isolates and vaccine viruses. The haemagglutinin (H) gene analysis showed that recent viruses did not differ significantly from vaccine strains. The analysis of the long untranslated region between the matrix (M) and fusion (F) gene revealed distinct genetic heterogeneity. The putative F protein start codon AUG461 of vaccine strain Onderstepoort was found to be mutated in all wild-type isolates and in another vaccine strain. The proximal coding part of the F gene was well conserved. Phylogenetic analysis of this segment showed the presence of several cocirculating CDV genotypes.

Animals↗
PubMed1999

Preliminary characterization of a reovirus isolated from golden ide Leuciscus idus melanotus.

Some characteristics of a reovirus recently isolated from golden ide Leuciscus idus melanotus and tentatively designated as golden ide reovirus (GIRV) were determined. Spherical non-enveloped particles with an outer capsid of about 70 nm and an inner capsid of about 50 nm were observed by electron microscopy. The density of the virus determined in CsCl gradients was 1.36 g ml-1. The genome contained 11 segments of dsRNA. GIRV differed from other aquareoviruses by a slight reduction of infectivity after treatment with chloroform and by the absence of forming syncytia in cell monolayers.

Animals↗