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Biomedical subjects

J Hoorens

Publications and source records attributed to J Hoorens.

At least 19 recordsLinked to original sources
PubMed1995

Accumulation of protoporphyrin isomers I and III, and multiple decarboxylation products of uroporphyrin in a case of porphyria in a slaughtered pig.

Pathological and biochemical examinations were made on tissues from a case of porphyria in a slaughtered pig. Bones, kidneys, teeth and lymph nodes showed a mahogany discoloration. Histologically, the pigment was negative on staining for iron (Gomori) and showed a strong red-orange fluorescence under UV light proving it to be porphyrin. Biochemical studies on the kidney, lymph nodes, bone and bone marrow revealed a 'mixed' erythropoietic protoporphyria-coproporphyria. This indicates that the case presented probably represented both a uroporphyrinogen decarboxylase and uroporphyrinogen-III-cosynthase dysfunction.

Abattoirs↗
PubMed1992

Actinobacillosis in bovine caesarean sections.

An infection with Actinobacillus lignieresii, which was spread by a veterinary surgeon, caused problems after caesarean sections in cows on several farms. The wounds became hard about six weeks after the operation, and a few weeks later small abscesses developed and later the wounds were covered with small and large granulomas. The general health of about 20 per cent of the affected cows was poor and in these cows multiple granulomas could be detected in the abdomen by rectal palpation.

Actinobacillosis↗
PubMed1989

Determination of beta-adrenoceptors and cAMP in muscle from normal and splayleg Belgian Landrace pigs.

beta-Adrenoceptors were identified and characterized by [3H]dihydroalprenolol ([ 3H]DHA) binding experiments in muscle membrane preparations from piglets. The [3H]DHA binding was rapid, reversible and stereoselective. Catecholamines competed for specific binding with a rank order of potency (-)-isopropylnoradrenaline greater than (-)-epinephrine much greater than (-)-norepinephrine, indicating a beta 2-subtype of adrenoceptor. Saturation binding experiments with [3H]DHA showed no significant difference for either the number of binding sites or the equilibrium dissociation constants in normal and splayleg pigs. Adenylate cyclase assays indicated that the basal adenylate cyclase activity and the prostaglandin E1 (PGE1)-, (-)-isopropylnoradrenaline (ISO)-, 5'-guanylyl-imidodiphosphate (GppNHp)- and sodium fluoride (NaF)-stimulated values were not significantly different in normal and splayleg pigs. In both groups, PGE1 did not affect basal activity, whereas ISO and GppNHp stimulated adenylate cyclase activity significantly (p less than 0.001) to about 40% above basal level. NaF induced a significant (p less than 0.001) increase of cAMP in normal and splayleg pigs amounting to 48% and 61% respectively. Significant correlations between absolute adenylate cyclase responses to ISO (r = 0.83***), NaF (r = 0.72**) and GppNHp (r = 0.61*) and basal activity in the splayleg pigs were the most striking findings. In contrast, these correlations could not be detected in the normal pigs. Whether or not this observation reflects an alteration in the signal transduction system needs to be further investigated. To the best of our knowledge this is the first biochemical study which relates an altered beta-adrenoceptor function and porcine splayleg.

Adenylyl Cyclases↗
PubMed1989

Type A2 congenital tremor in piglets.

A neonatal congenital tremor (CT) syndrome that sporadically occurs in Belgian piglets is described. The results of an epidemiologic follow-up survey on affected farms is presented. Experimental trials to provoke this syndrome by inoculation of a brain suspension, derived from CT-piglets, in pregnant sows by intramuscular and intrauterine way, partly succeeded. Histological and biochemical studies on brain tissue of these piglets indicated that this form of CT should be classified as an A2 form. Using serologic and virologic examinations we were however not able to identify the probably infectious CT-agent.

Animals↗
PubMed1989

Morphometric evaluation of myofibrillar hypoplasia in splayleg piglets.

A morphometric method was applied to evaluate the EMS (extramyofibrillar space) in cross-sections of the musculus adductor as a parameter for the grading of the myofibrillar hypoplasia in splayleg piglets. Although there was a great variability between the individual piglets for the EMS values, a highly significant difference between normal and splayleg piglets was noted. Using this method it was found that myofibrillar hypoplasia indeed is associated with the splayleg syndrome.

Animals↗
PubMed1988

Effect of experimentally-induced villus atrophy on adhesion of K88ac-positive Escherichia coli in just-weaned piglets.

Three- to four-week-old, just-weaned piglets were infected with transmissible gastroenteritis (TGE) virus and the next day with K88ac+ enterotoxigenic Escherichia coli (ETEC). Histological examination of caudal jejunum and ileum of piglets killed 2-3 days after virus challenge (1-2 days after ETEC infection) revealed severe villus atrophy especially in the jejunum compared with controls (P less than 0.05). Four-5 days after TGE virus infection villus length increased and after 7 days it was near normal. Villi scraped from jejunal and ileal mucosa of the piglets were incubated in vitro with K88ac+ E. coli and the number of bacteria adhering to 250 micron villus brush border was counted. Attachment of bacteria to villi of piglets killed 2-3 days after TGE virus infection was significantly decreased in comparison with adhesion to villi of non-infected piglets or of piglets killed 7 days after the virus infection. Correlation between in vitro adhesion and villus height was 0.6649 (P less than 0.001). The results suggest that the experimentally-induced villus atrophy was attended with a temporarily diminished susceptibility of villus enterocytes to adhesion of K88ac+ E. coli.

Animals↗
PubMed1985

Immunoperoxidase study of adenovirus pneumonia in dogs.

The pathology of adenovirus pneumonia in 16 dogs is described. Clinically, these dogs had been severely ill, with severe dyspnoea and listlessness, but only faint coughing. Histopathological lesions could be associated directly with the presence of adenovirus antigens in the lungs of these dogs by using an unlabelled immunoperoxidase technique on paraffin tissue sections. The lesions were focal and located in alveoli and bronchioles. Infected cells were mostly alveolar macrophages and less frequently type 1 and 2 pneumocytes and bronchiolar epithelial cells. Infiltrating neutrophils and lymphocytes were not observed to be infected. This type of pneumonia appears to be a fairly well defined clinical and pathological entity in kennel dogs.

Adenoviridae Infections↗
PubMed1984

Space occupying lesions of cranial nerves in calves with facial paralysis.

Clinical and pathological data of a recently discovered neurological disorder in young calves were studied. The symptoms were those of a paralysis of the nervus facialis and a dysfunction of the nervus vestibulocochlearis. Macroscopically, space occupying lesions were found at the roots of these two cranial nerves and in some cases further on their course into the os petrosum. On histological examination, these legions contained multiple nodules with mainly histiocytic cells, some plasma cells and multinucleated giant cells. Around these nodules, dense bands of connective tissue with fusocellular fibroblasts, some plasma cells and small blood capillaries were present. The nodular lesions were usually in close contact with the nerve. Ultrastructurally, a variety of cells, predominantly histiocytes and some plasma cells, were seen next to Schwann cells which contained degenerating axons.

Animals↗
PubMed1984

Significance of lysosomes in the morphogenesis of coronaviruses.

Virus-containing electron-dense membrane-bound cytoplasmic bodies are described in tracheal epithelial cells of chickens infected with Infectious Bronchitis Virus and in intestinal epithelial cells of swine infected with Porcine Epidemic Diarrhea Virus. Using silver-methenamine staining, phosphotungstic acid staining and acid phosphatase enzyme cytochemical staining of ultra-thin sections, these bodies were shown to be virus-containing secondary lysosomes and residual bodies. The accumulation of viral particles in the lysosomes is suggested to possibly represent an intracellular defense mechanism. However, no morphological alterations were found indicating a destruction of the viruses by the lytic lysosomal enzymes.

Animals↗
PubMed1984

Demonstration of pseudorabies viral antigen in thick and ultrathin tissue sections of young pigs using an immunogold method.

Pseudorabies (Aujeszky's) virus antigens were labeled in thick and ultrathin tissue sections of young pig brain and liver tissue, using an indirect immunogold method. Antigens were tagged with 20 nm gold particles. Controls proved the specificity of the reaction in paraffin sections and ultrathin epoxy sections. Immunogold staining was compared with immunoperoxidase staining in paraffin sections. In ultrathin sections stained with the immunogold method, the gold particles were present on viral nucleocapsids and viral envelopes, as well as on a number of other intracellular structures. These included the inner nuclear membrane, the nucleoplasm, intranuclear filaments, the endoplasmic reticulum, and free cytoplasmic polyribosomes. Gold particles were absent on mitochondria and microtubules. In paraffin sections, immunogold labeling for pseudorabies virus antigen was less sensitive than immunoperoxidase staining. Immunogold staining of ultrathin tissue sections can yield additional information on virus-host cell interactions.

Animals↗
PubMed1983

Immunoperoxidase study of canine distemper virus pneumonia.

Forty-two cases of canine pneumonia were examined for the presence of canine distemper virus. For that purpose canine distemper virus inclusion bodies were located. The histopathological lesions were related to the presence of canine distemper antigen, as demonstrated with an immunoperoxidase technique. This technique was more sensitive for detecting canine distemper infection in lung tissue than was the study of inclusion bodies. Attention was also paid to combined infection with canine adenovirus and Bordetella bronchiseptica.

Adenoviridae Infections↗
PubMed1982

Dual adenovirus and distemper virus pneumonia in a dog.

A case of simultaneous infection of the lungs of a dog with canine distemper virus (CDV) and canine adenovirus (CAV) is described. The techniques employed are histological stains, immunoperoxidase technique, and transmission electron microscopy. Two viruses are shown to infect the same cells. The significance of dual infection of the same cells is discussed in comparison with literature data on in vitro experiments.

Adenoviridae Infections↗