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Biomedical subjects

J Hoorens

Publications and source records attributed to J Hoorens.

At least 37 records · Page 2Linked to original sources

Pathology of experimental CV777 coronavirus enteritis in piglets. I. Histological and histochemical study.

Sixteen cesarean-derived colostrum-deprived piglets were infected oronasally with CV777 coronavirus on the second or third day of life. Two uninfected piglets were controls. They were killed at 96 and 120 hours after birth. After an incubation period of 22 to 36 hours, all principals showed severe diarrhea. The principals were killed between 12 and 120 hours after infection. Exfoliation of enterocytes were seen first in the piglet killed 24 hours after infection (two hours after the diarrhea began). From that time on, shortening and fusion of villi was present in all small intestinal parts. Affected cells showed vacuolation. The histochemical study showed that infected piglets had decreased activity of all four enzymes studied. The light microscope showed no lesions in the absorptive colonic epithelium. The significance of the lesions in relation to intestinal dysfunction is discussed, and lesions are compared to those of transmissible gastroenteritis and porcine rotavirus infection.

Animals↗

Pathology of experimental CV777 coronavirus enteritis in piglets. II. Electron microscopic study.

Sixteen cesarean-derived, colostrum-deprived piglets were infected oronasally with CV777 coronavirus on the second or third day of life. Two uninfected piglets were controls. After an incubation period of 22 hours to 36 hours, all principals showed severe diarrhea. The piglets were killed at different time intervals. Viral particles were found in the jejunal villous epithelial cells from 18 hours after infection until four days after the beginning of diarrhea. In the colonic epithelial cells, viral particles and degenerative lesions were found only in the piglet killed 36 hours after onset of diarrhea. Degenerative lesions in the enterocytes began at 18 hours after infection and were most pronounced in the jejunum at the onset of clinical signs. From 24 hours on after the onset of clinical signs, three cell types were found: degenerated virus-containing enterocytes; cuboidal cells; and columnar, highly vacuolated cells containing lipid droplets.

Animals↗

Sequential pathological study of experimental porcine adenovirus enteritis.

The sequential enteric lesions of experimental porcine adenovirus strain 6618 infection were studied in 18 hysterotomy-derived, colostrum-deprived piglets, by histology, transmission electron microscopy, and an immunoperoxidase technique. Viral particles could be seen in altered epithelial cells of the lower small intestine from 24 hours until 16 days after inoculation. With the immunoperoxidase technique, viral antigen could be found in epithelial cells at 45 days after challenge. Destruction of epithelial cells and shortening of villi could be related directly to the presence of the virus. Histology of the lower jejunum and ileum, which demonstrates intranuclear inclusion bodies, is proposed as a useful diagnostic technique.

Adenoviridae Infections↗

Immunoperoxidase study of Aujeszky's disease in pigs.

Viral antigen was detected by an immunoperoxidase technique in histological sections from pigs with Aujeszky's disease. The antigen was found mainly in association with focal necrosis in the cerebellum, tonsils, oral and nasal mucosa, salivary glands, lungs, liver, kidneys, pancreas, spleen and adrenal glands. Cells at the margin of the necrotic foci especially were strongly positive. Viral antigen was also demonstrated in the cerebral cortex and in the brain stem. Two types of intranuclear inclusion bodies were found to contain viral antigen and one type also contained viral nucleic acids. Inflammatory cells usually contained no viral antigen. The possible significance of some of these infected tissues in the excretion of the virus is discussed.

Animals↗

Replication of porcine enteric adenoviruses in vivo.

The replication of an enteropathogenic porcine adenovirus in the intestinal epithelial cells of naturally and experimentally piglets has been studied by transmission electron microscopy (TEM) and by immunoperoxidase (Ip) staining of paraffin sections. Three types of intranuclear inclusion bodies were observed. Viral particles appeared to be assembled from electron dense crescents which seemed to originate from type II intranuclear inclusion bodies. Virus accumulated in the nucleus of infected cells. It formed paracrystalline arrays in the electron dense centre of the nucleus but was dispersed in the peripheral electron translucent zone. Virus was released from the cells after rupture of the nuclear and plasma membranes. The results are compared with published data on the replication of adenoviruses in cell cultures.

Adenoviridae↗

Adenovirus enteritis in pigs.

Experimental transmissions were done with adenovirus strain 6618 in hysterectomy-produced colostrum-deprived pigs. After an incubation period of 3 to 4 days, all inoculated animals had diarrhea. Histopathologically, many intranuclear inclusion bodies were present on short villi of the terminal parts of jejunum and ileum. With electron microscopy, the inclusion bodies were observed to contain numerous adenovirus particles. Immunoperoxidase-positive cells were seen on short villi of the terminal parts of jejunum and ileum. Adenovirus particles also were detected by negative staining of intestinal contents. In 1 pig (naturally occurring infection), adenovirus enteritis was studied by the aforementioned techniques. Similar intestinal lesions as described in the experimental pigs were observed.

Adenoviridae Infections↗

Coronavirus infection in a litter of pups.

An outbreak of a coronavirus infection in a litter of 10-week-old poodle pups from a commercial kennel is described. Coronavirus-like particles were demonstrated by electron microscopy in the intestinal contents and in the colonic mucosa. Treponemas and campylobacters were excreted in great numbers in the faeces. The gastrointestinal disturbances were complicated by hepatic and renal degeneration and severe bronchopneumonia.

Animals↗

An electron microscopic study of experimentally-induced HEV encephalitis.

A gnobiotic piglet, was inoculated intracerebrally with hemagglutinating encephalomyelitis virus (strain VW572). Mononuclear cells formed vascular cuffs and were disseminated in the brain parenchyma. A few neurons were surrounded by the same kind of cells. Virus particles morphologically similar to coronavirus particles were found in the cytoplasm of both chromatolytic light neurons and hyperchromic dark neurons. The particles were in vesicles of distended endoplasmic reticulum and in the hypertrophied Golgi apparatus.

Animals↗