Biomedical subjects

W Baumgärtner

Publications and source records attributed to W Baumgärtner.

At least 19 recordsLinked to original sources

PubMed2006

An unusual mucinous osteoma with features of an ossifying fibroma in the nasal cavity of a horse.

A 4-month-old Warm-blooded colt presented with facial distorsion and an abnormal respiratory noise of 2 weeks' duration. A proliferative mass was found endoscopically and by computer tomography. Clinical differential diagnosis included cyst formation of the concha, malformation and neoplasia. Euthanasia was followed by post-mortem examination, which revealed a well-circumscribed, semi-solid, jelly like structure, measuring 14.5 x 9.0 x 12.0 cm, in the left posterior nasal cavity extending into the left frontal and maxillary sinus. Histologically, the mass consisted of trabeculae of woven bone, focal lamellar bone and fibroblast proliferation within a moderate fibro-vascular stroma. Abundant mucin production was noted within areas of fibroblastic differentiation. Some areas contained irregularly shaped spicules of osteoid rimmed by osteoblasts, randomly distributed within a moderately vascularized, fibro-osseous stroma. On the basis of the histopathological features, a nasal mucinous osteoma with focal ossifying fibroma-like structures was diagnosed.

Animals↗

PubMed2006

Pathological findings in harbour porpoises (Phocoena phocoena) from Norwegian and Icelandic waters.

A study of 37 by-caught harbour porpoises from Icelandic and Norwegian waters showed that most were in good or moderate nutritional condition and none was severely emaciated. Mild infection with lungworms (Halocercus invaginatus, Pseudalius inflexus, Torynurus convolutus) was found in 84% of the Icelandic and 91% of the Norwegian animals, usually associated with bronchopneumonia which was rarely severe. Most (91%) of the animals had parasites in the stomach and intestine (Anisakis simplex, Contracaecum osculatum, Pholeter gastrophilus), and Campula oblonga was present in the liver and pancreas of 88 and 21%, respectively. Oesophagitis, gastritis, cholangitis, pericholangitis, pancreatitis and lymphadenitis were almost exclusively associated with parasitic infection and usually mild. Bacterial isolates were obtained from 50 to 55% of the animals but were not considered to be clinically significant. There was no indication of morbillivirus infection. Icelandic and Norwegian animals showed a thicker blubber layer and a lower incidence of severe lesions, especially in the respiratory tract, as compared with reports of by-caught animals from the Baltic Sea.

Animals↗

PubMed2006

Metastasizing oral squamous cell carcinoma in an aged pig.

A 10-year-old, female, pot-bellied pig (Sus scrofa) experienced a 3-month history of reduced appetite, dysphagia, and weight loss. Clinical examination revealed a mass in the left part of the oral cavity extending from the hard to the soft palate. At necropsy, a firm, white, poorly demarcated ulcerated mass at the left hard and soft palate with metastases to the left retropharyngeal lymph node and the lung was observed. Additional findings included a uterine adenocarcinoma, a hepatocellular adenoma, and nodular hyperplasias in spleen and adrenal glands. Histologically, the poorly demarcated, infiltrative growing oral mass consisted of islands, cords, and single epithelial cells with moderate squamous differentiation. Cells were strongly positive for cytokeratin by immunohistochemistry. Similar cells were found in the left retropharyngeal lymph node and the lung. The present findings represent the first report of a metastasizing oral squamous cell carcinoma in a pig.

Animals↗

PubMed2006

A case of interface perianal dermatitis in a dog: is this an unusual manifestation of lupus erythematosus?

Discoid lupus erythematosus (DLE) is a well-known autoimmune disorder described in dogs and humans. In dogs, DLE is considered the second most common immune-mediated dermatitis and is usually localized to the nasal planum. DLE does not evolve to generalized disease, however lesions may spread to the bridge of the nose and less commonly may extend to periocular region, pinnae, distal limbs, and mucocutaneous junctions (lips, oral cavity, and genital region). A 4-year-old male Bavarian Mountain Scenthound developed a chronic, erosive, cutaneous lesion located exclusively in the perianal region without facial skin involvement. Clinical signs included erythema, depigmentation, severe alopecia, crusting, and ulceration. Histologically, the hallmarks of the changes were an interface dermatitis consisting of plasma cells, lymphocytes, neutrophils, and macrophages, hydropic degeneration of basal cells, few apoptotic cells in the basal layer, pigmentary incontinence, and a focal thickening of the basement membrane, which was characterized by linear deposition of IgG. Despite the unusual localization the lesion was diagnosed as DLE based on the characteristic histologic and immunohistologic features. Following diagnosis, corticosteroid therapy resulted in a complete resolution of perianal lesions.

Anal Canal↗

PubMed2006

[Pathological and histopathological findings in the joints of fattening turkeys].

This paper reports on pathological and histopathological findings in the joints of male turkeys (B.U.T. Big 6) reared in two different housing systems. Pathological investigations were conducted on all animals which died between the 6th week of life and the end of fattening (585 birds, 1170 hip, knee and intertarsal joints) from four fattening periods with 3000 birds each. This study included 297 birds kept in a conventional housing system (barn 2) with a stocking density of 2.8 birds/m2, and 288 birds from a barn (1) from which the animals had access to an outdoor scratching area (stocking density 2.5 birds/m2). In all, 157 (26.5%) of the 585 fallen turkeys (barn 1:93; barn 2:70) showed at least one pathological joint alteration. and there were macroscopically detectable changes in 274 (7.8%) of the 3510 investigated joints: 152 (7.8%) of the 1728 joints from barn 1, and 122 (8.8%) of the 1782 from barn 2. In both housing systems the most frequent pathological alterations were in the intertarsal joint affecting 16% (188) of these 1170 joints (barn 1:106; barn 2:82); next most frequent were changes in the knee joint with 4.5% (53) of the 1170 joints affected (barn 1:26; barn 2:27). In both barns, synovial alterations occurred predominantly in the intertarsal and the knee joints. Bacteriological investigation of altered synovial fluids (83) most frequently showed an infection with Staphylococcus spp. (44) and E. coli (15). Macroscopic investigation showed alterations in 31 (2.7%) of the 1170 hip joints (barn 1:19; barn 2:12); 2% (22) of these showed cartilage degenerations of the femoral head (barn 1:15; barn 2:7). Histological investigation of these cartilage lesions showed that they were predominantly (70%) due to osteochondrosis with complete epiphyseolysis affecting 16 femoral heads (barn 1:10; barn 2:6). Partial epiphysiolysis was found in 24% (5) of the femoral heads (barn 1:4; barn 2:1). Furthermore, 43% (9) of the 22 femoral heads with cartilage degeneration also had osteomyelitis and osteochondritis, as well (barn 1:6; barn 2:3). Histological investigation of the 104 femoral heads with no macroscopic findings (barn 1:56; barn 2:48), revealed osteochondrosis in 11 cases (10.6%) (barn 1:6; barn 2:5). Osteomyelitis and osteochondritis were found in 17 (16.3%) of these femoral heads (barn 1:9; barn 2:8). There were no significant (p < 0.05) differences between the two housing systems in the incidence and frequency of joint alterations. It is to be assumed that these joint alterations were the cause of acute, chronic pain.

Animals↗

PubMed2006

Roles of an extracellular matrix (ECM) receptor and ECM processing enzymes in demyelinating canine distemper encephalitis.

Canine distemper virus (CDV) belongs to the genus Morbillivirus of the Paramyxoviridae family. Due to the central nervous system (CNS) tropism of the virus and associated neuropathological changes, demyelinating canine distemper encephalitis (CDE) represents a relevant model for human demyelinating diseases like multiple sclerosis. The present review decribes the role of CD44 antigen (CD44), the principle cell surface receptor for hyaluronate and extracellular matrix (ECM) processing enzymes (matrix metalloproteinases [MMPs]) and their inhibitors (TIMPs) in the pathogenesis of demyelination. In acute and subacute CDE, a plaque-associated CD44 up-regulation is found that parallels astrocyte activation. Likewise, MMPs and TIMPs are prominently up-regulated in these lesions and are expressed mostly by astrocytes and microglia. In chronic lesions, CD44 expression declines together with the number of glial fibrillary acidic protein (GFAP) positive astrocytes. In addition, in this plaque type, CD44 is expressed on the cell membrane of perivascular mononuclear cells. In this phase, a decrease of MMP and TIMP expressions apart from MMP-11, -12, and -13 is obvious. In summary, CD44 and MMPs might be associated with the onset of demyelination and may interact to initiate ECM disturbances. Ligation of CD44 in the early phase may induce chemokines and cytokines and hence initiate and perpetuate the inflammatory process. In the chronic phase, it is conceivable that a MMP-TIMP imbalance may be the motor for lesion progression with a simultaneous influx of CD44-positive activated immune cells.

Animals↗

PubMed2005

A comparison of immunohistochemical and silver staining methods for the detection of diffuse plaques in the aged canine brain.

Plaques and amyloid angiopathy represent frequent findings in the aging canine brain, whereas neuritic (senile) plaques and neurofibrillary tangles, the hallmark of Alzheimer's disease in humans, have only rarely been described in this species. Most studies on canine age-related CNS changes have used the modified (mod.) Bielschowsky method. Therefore, it remains to be determined, whether results obtained represent species-specific age-related changes or are due to the use of inappropriate methods. Consequently, the aim of this study was to compare the usefulness of various methods for the detection of age-related changes in the canine CNS. In a preliminary study, 130 brains from dogs between 1 month and 18 years of age were screened for the presence of A-beta protein using a monoclonal antibody against the beta-amyloid peptide. Thereafter, 30 brains of aged dogs, 10-18 years of age, out of the 130, were comparatively investigated by immunohistochemistry and silver stains such as the method of Campbell-Switzer, Reusche, Gallyas, modified (mod.) Bielschowsky and mod. Bodian as well as the Congo red-stain. Vascular amyloid angiopathy, plaques and A-beta protein deposits in the hippocampus/dentate gyrus were an age-dependent process starting at the age of 8 years and increased in a linear fashion with age. In contrast, plaque density did not rise in a similar age-related fashion in aged dogs. Moreover, great individual variations were observed in aged animals. Immunohistology was by far the most sensitive method for detection of diffuse plaques and amyloid angiopathy, followed by the Campbell-Switzer, Reusche, mod. Bielschowsky, and mod. Bodian technique. Neurofibrillary tangles and Congo red positive neuritic plaques were not found with any method. Immunohistochemically, two plaque types, both resembling diffuse human plaques, occurring in the superficial or deep cortical layers, were detected. Cluster analysis suggested the presence of three subgroups such as aged dogs with a low, medium and high number of plaques. Summarized, detection of plaques depends strongly upon the method used and the aging canine brain displays diffuse plaques and amyloid angiopathy but lacks neurofibrillary tangles and classic/neuritic and Congo red positive plaques. Cluster analysis indicated, that genetic factors might be important as predisposition for the development of diffuse plaques in dogs. The observed findings substantiate previous observations, that the canine brain represents an important model to study the pathogenesis of diffuse plaques and amyloid angiopathy in the absence of other Alzheimer disease characteristic lesions.

Age Factors↗

PubMed2005

Ectodysplasin-1 deficiency in a German Holstein bull associated with loss of respiratory mucous glands and chronic rhinotracheitis.

A 2-year-old German Holstein bull was identified as a carrier of a mutation within the X-chromosomal ED1 gene, which encodes a TNF-related signalling molecule mainly involved in ectodermal development. The clinicopathological appearance was associated with hypotrichosis, hypodontia, and a reduced number of eccrine glands, in addition to chronic rhinotracheitis and partial squamous metaplasia. Furthermore, for the first time in an ED1-deficient animal, a complete lack of respiratory mucous glands was observed. This suggests that the ED1 gene plays a role in the development of mucous glands, the absence of which resembles a feature of X-linked anhidrotic ectodermal dysplasia (ED1) in human patients.

Animals↗

PubMed2005

Primary endocardial malignant spindle-cell sarcoma in the right atrium of a dog resembling a malignant peripheral nerve sheath tumour.

An unusual malignant spindle-cell sarcoma in the right atrium of a 7-year-old male hunting terrier is described. The neoplasm arose from the endocardium, protruded into the lumen of the right atrium, was covered with endothelium, and showed local invasive growth into the atrial wall. The tumour was composed of interlacing bundles of spindle cells, sometimes arranged in whorls resembling the Antoni type A pattern. The extracellular matrix showed abundant reticulin fibres. Immunohistochemistry revealed an intense labelling of tumour cells for vimentin, and a partial labelling for neuron-specific enolase, S100 protein, and Melan-A. The morphology of the tumour indicated a primary malignant peripheral nerve sheath tumour, resembling a neoplasm described in rats.

Animals↗

PubMed2004

Metastatic esthesioneuroblastoma in a horse.

A 17-year-old horse developed severe proptosis of the left eye over a period of 1.5 years. At post-mortem examination a neoplasm was found involving the left ethmoid bone, left maxillary sinus, left orbit, left superior turbinate, and the left eye. Tumour cells were arranged in nests separated by a fine fibrovascular stroma. Immunohistochemically, the tumour cells were labelled by antibodies against neurofilament protein, synaptophysin, glial fibrillary acidic protein and S-100 protein antigen, but were negative for chromogranin A, cytokeratin and desmin. Electronmicroscopically, the cells showed neurosecretory granules with an electron-dense centre and a light halo, and microfilaments. On the basis of macroscopical, light microscopical and ultrastructural findings a diagnosis of a metastatic esthesioneuroblastoma was made.

Animals↗

PubMed2004

Development of a lymphocyte-transformation-assay for peripheral blood lymphocytes of the harbor porpoise and detection of cytokines using the reverse-transcription polymerase chain reaction.

Impairment of immune function is suggested to play a contributing role for the increasing incidence of infectious diseases in the harbor porpoise (Phocoena phocoena) of the North and Baltic Seas. Both, lymphocyte-transformation-assay of peripheral blood lymphocytes (PBMC) and detection of cytokine expression are important tools for the characterization of the cellular immune response. To evaluate optimal parameters for the lymphocyte-transformation-assay isolated blood lymphocytes from four healthy harbor porpoises were stimulated with different concentrations of concanavalin A (Con A), phytohemagglutinin (PHA) and pokeweed mitogen (PWM). Cell proliferation was measured photometrically after 72 h using 5-bromo-deoxyuridine-assay and stimulation indices were calculated. The expression of pro- and anti-inflammatory cytokines such as interleukin (IL)-2, IL-4, IL-6, IL-10, transforming growth factor (TGF)-beta, and tumor necrosis factor (TNF)-alpha was investigated in control and mitogen-stimulated lymphocytes using reverse-transcription polymerase chain reaction (RT-PCR). Primers for IL-2, IL-4 and IL-6 were selected from published cDNA-sequences of other cetaceans. Established canine and human primers were taken for the detection of TNF-alpha, TGF-beta, IL-10 and the house keeping transcript glyceraldehyde-3-phosphate dehydrogenase (GAPDH), respectively. Specificity of the amplicon was confirmed by DNA sequence analysis and comparison with nucleotide sequences of other marine and terrestrial mammals. Con A and PHA represented the most powerful mitogens for harbor porpoise lymphoid cells at concentrations of 5 and 2 microg/ml, respectively, while PWM induced a comparatively low maximum proliferation at a concentration of 2 microg/ml. GAPDH was amplified in non-stimulated and all mitogen-stimulated cells. With the exception of IL-10 none of the other cytokines were detected in non-stimulated cells. Transcription of IL-4, IL-6, IL-10, TNF-alpha and TGF-beta-mRNA was observed after incubation with all the three phytomitogens, whereas IL-2 was only detected in Con A and PWM treated cells. Lymphocyte-transformation-assay and RT-PCR for detection of cytokines will allow to investigate possible impaired immune function in the harbor porpoise in future studies.

Animals↗

PubMed2004

Disseminated Mycobacterium avium-intracellulare Infection in a Persian cat.

This report describes a disseminated infection with mycobacteria of the avium/intracellulare complex in a Persian cat in the absence of cutaneous lesions. Postmortem examination revealed severe granulomatous inflammation with numerous intrahistiocytic acid-fast bacilli in multiple organs. A gastrointestinal port of entry seems likely, as the ileocaecal lymph node was most severely affected.

Animals↗

PubMed2004

Immunohistochemical detection of CD4-, CD8- and MHC II-expressing immune cells and endoglin in the canine corpus luteum at different stages of dioestrus.

Specific immunohistochemical methods were applied to detect the presence of CD4-, CD8- and major histocompatibility complex II (MHC II)-expressing immune cells and of endoglin in the canine corpus luteum between days 15 and 75, after ovulation. Corpora lutea were obtained from groups of three clinically healthy beagle bitches, ovariohysterectomized at the respective days. For all four parameters, the effect of time was highly significant. Quantitative evaluation yielded high values on day 15, followed by a decrease on day 30 (CD4, CD8 and endoglin) and day 45 (MHC II). While there were no further changes for cells staining positive for CD4 and endoglin, CD8-positive immune cells increased from day 45 to day 60 to drop again on day 75; MHC II-positive staining increased from day 45 to days 60-75. These data suggest an involvement of the immune system in control of luteal function also in the dog that may have both stimulatory and inhibiting effects.

Animals↗

PubMed2004

Histopathology and immunohistochemistry of canine distemper virus-induced footpad hyperkeratosis (hard Pad disease) in dogs with natural canine distemper.

Hard pad disease represents an uncommon manifestation of canine distemper virus (CDV) infection with a still uncertain pathogenesis. To study the pathogenesis of this uncommon, virally induced cutaneous lesion, the footpads of 19 dogs with naturally occurring distemper were investigated for histologic changes and distribution pattern of CDV antigen. All dogs displayed clinical signs of distemper, which had lasted from 10 to 75 days. Overt digital hyperkeratosis was observed in 12 animals (group A), whereas the footpads of the remaining seven dogs appeared normal macroscopically (group B). Orthokeratotic hyperkeratosis (12/12; 100%), irregular acanthosis (11/12; 92%), thickened rete ridges (10/12; 83%), and mild mononuclear perivascular (10/ 12; 83%) and periadnexal (7/12; 58%) dermatitis were the most common findings in dogs with hard pad disease. Surprisingly, orthokeratotic hyperkeratosis (5/7; 71%), irregular acanthosis (5/7; 71%), and thickened rete ridges (4/7; 57%) were also seen in the dogs without clinical evidence of digital hyperkeratosis. CDV-specific inclusion bodies and ballooning degeneration were not observed in the footpad epidermis of the 19 dogs. Immunohis-tochemistry revealed that CDV antigen was most frequently found in the stratum spinosum and granulosum and in the epithelial cells of the eccrine sweat glands and only rarely in the basal layer. Fibroblasts, pericytes, endothelial cells, and hair follicles were also positive in some animals. Despite the obvious difference regarding the macroscopic picture, the microscopic changes were less prominent between the animal groups. The selective infection of keratinocytes in the stratum spinosum might be the key event for the development of hard pad disease in the dog.

Animals↗

PubMed2004

Oligodendroglioma in the cervical spinal cord of a dog.

A 7-year-old male castrated Yorkshire Terrier dog developed slowly progressive neurologic disturbances consisting of difficulties in moving the neck, lack of proprioception, and tetraparesis 4 months prior its death. Neurologic examination, computer tomography, and myelography resulted in the tentative diagnosis of intramedullary cervicothoracic spinal cord lesion. At necropsy, an intramedullary cervical spinal cord mass between C5 and C6 was noticed. Histologically, cells of this well-demarcated, nonencapsulated neoplasm were arranged in sheaths or cords separated by a fine fibrovascular stroma. The polygonal to round tumor cells were characterized by moderate pale, basophilic, and vacuolar cytoplasm and round to slightly oval, centrally located nuclei with fine-stippled heterochromatin, a single nucleolus, and a very low mitotic activity. Tumor cells lacked glial fibrillary acidic protein, vimentin, factor VIII-related, and cytokeratin antigen expression. Histologic and immunohistochemical findings led to the diagnosis of a cervical spinal cord oligodendroglioma.

Animals↗

PubMed2004

[Case report. Restrictive cardiomyopathy with chylothorax in a cat: the pathogenesis].

A 8.5 year old castrated female domestic short-haired cat was presented because of progressive dyspnea, inappetence and weight loss. Special examinations revealed a chylothorax. In addition a restrictive cardiomyopathy was suspected. The cat was euthanized. The histopathologic examination of the heart confirmed the diagnosis of restrictive cardiomyopathy. The examination of the ductus thoracicus showed a intramural fibrosis with additional edema and a interstitial partly perivascular inflammation. The coherence between feline cardiopathy and chylothorax was discussed speculatively in previous reports. In this report we show a possible aetiopathology.

Animals↗

PubMed2003

Unusual manifestation of hepatic encephalopathy in two Irish wolfhound siblings.

In hepatic encephalopathy the brain lesions are usually characterised by polymicrocavitation, preferentially in the white matter, and the occurrence of Alzheimer type II cells. This paper describes an unusual manifestation of hepatic encephalopathy in two Irish wolfhound siblings in which the white matter was not involved predominantly. Both puppies had developed progressive neurological disturbances and signs of blindness. Histologically, there were widespread spongiform changes in the neuropil and fibre bundles interspersed within the grey matter, and there were some neuronal vacuoles. In both animals, the regions of the brain mainly affected were the nucleus caudatus, amygdala, cerebellar nuclei, mesencephalon, thalamus, hypothalamus and medulla oblongata. An astrogliosis characterised by Alzheimer type II-like cells was also observed. Electron microscopy revealed a splitting of the myelin sheath. No infectious agents such as rabies virus, canine distemper virus or prion proteins were detected. The main findings in the portal regions of the liver consisted of a dilatation of the lymphatic vessels and increased numbers of small arteries, indicating that a portosystemic shunt was the probable cause of the spongiform brain lesions.

Animals↗

PubMed2003

Non-cytocidal infection of keratinocytes by canine distemper virus in the so-called hard pad disease of canine distemper.

A late, but not uncommon sequel to canine distemper virus (CDV) infection of dogs is thickening of footpads and nasal planum, the so-called hard pad disease, originally described as vacuolar degeneration of epidermal keratinocytes with inclusion body formation and massive hyperkeratosis. However, in a recent study of footpads of naturally CDV-infected dogs only hyperkeratosis was observed without any of the other changes. Instead, acanthosis was frequently noticed. CDV nucleoprotein was present in the suprabasal keratinocytes and eccrine epithelial glands only. No CDV nucleoprotein was present in basal keratinocytes. This observation in combination with lack of obvious cytocidal changes strongly suggested the possibility of a restricted viral infection with presence of viral mRNA but without protein expression. Therefore, the presence of CDV nucleoprotein mRNA was investigated using in situ hybridization and compared to the localization of the nucleoprotein in footpads of clinically healthy and distemper dogs. Viral nucleoprotein and nucleoprotein mRNA in nearly all cases co-localized to the same compartments and basal keratinocytes did not contain nucleoprotein mRNA. These findings dispute the idea of a restricted viral infection of footpad keratinocytes in dogs with natural CDV infection. Instead, a migration of the virus to the epidermal surface along with the proliferating and differentiating epithelium is the most likely explanation for the lack of virus antigen in basal keratinocytes.

Animals↗