PubMed Health⌕ Search

Biomedical subjects

K W Angus

Publications and source records attributed to K W Angus.

At least 55 records · Page 3Linked to original sources
PubMed1982

Pneumonia in sheep associated with dipping in carbolic dips.

Fourteen outbreaks of pneumonia in sheep following dipping in carbolic dips were investigated at seven laboratories. Deaths commonly occurred between one and three days after dipping and fat young sheep of the Suffolk and Border Leicester breeds were most usually involved in outbreaks. The pneumonia was characterised by hyperaemic, oedematous and cyanotic lungs, and the main histological features were hyperaemia, fluid and cellular exudation into alveolar spaces, and widespread epithelialisation of alveolar walls. The microscopic changes differed from pneumonic pasteurellosis and no significant organisms were recovered from any of the lungs. One of 27 Dorset Horn lambs dipped in a batch of dip which had been incriminated in some episodes developed an epithelialising interstitial pneumonia, while two out of three Suffolk lambs dipped in twice the recommended strength of the same batch of dip became ill with severe pneumonia, apparently following skin absorption.

Animals↗
PubMed1982

The therapeutic effect of 16 antimicrobial agents on Cryptosporidium infection in mice.

The therapeutic efficiency of 16 anti-microbial agents (Ethopabate, Nicarbazin, Sulphaquinoxaline, Furaltadone, Enterolyte-N, Sulphamethazine, Trinamide, Amprol, Phenamidine, Zoaquin, Halofuginone, Salinomycin, Monensin, Emtryl, Arprinocid and Amprolium) were examined against Cryptosporidium infections in mice. The Cryptosporidium was originally isolated from a field outbreak of calf diarrhoea. The drugs neither prevented nor modified the course of the infection as compared with infected, untreated mice.

Animals↗
PubMed1982

Experimental cryptosporidiosis in laboratory mice.

Eight strains of laboratory mice were susceptible to subclinical infections with Cryptosporidium sp. at 1 to 4 days of age, but only a transient infection could be established at 21 days of age or older. Immunosuppression of 21-day-old mice failed to render them more susceptible to infection. Laboratory storage conditions for Cryptosporidium sp. were investigated by titration in 1- to 4-day-old mice. Storage by freezing with a variety of cryoprotectants was unsuccessful, but storage at 4 degrees C in phosphate-buffered saline or 2.5% potassium dichromate was possible for 4 to 6 months.

Aging↗
PubMed1982

Experimental infection of lambs with Cryptosporidium isolated from a human patient with diarrhoea.

An inoculum containing Cryptosporidium oocysts obtained from an adult human patient with acute transient diarrhoea induced enteritis in two newborn specific pathogen free lambs. Three days after inoculation the lambs became depressed and diarrhoeic, their milk intake was reduced and Cryptosporidium oocysts were detected in their faeces. Mucosal changes observed in the small intestine of one infected lamb were consistent with but less severe than those induced experimentally in lambs by cryptosporidia isolated from calves and lambs.

Animals↗
PubMed1982

Intestinal lesions in specific-pathogen-free lambs associated with a cryptosporidium from calves with diarrhea.

Small and large intestines of seven specific pathogen-free lambs infected with cryptosporidia from calves with diarrhea were examined by scanning and transmission electron microscopy and by light microscopy. The small intestine was infected in all the lambs, and the cecum and colon in three. Small intestinal alterations were severe villous atrophy and dilatation of the crypts of Lieberkühn. Epithelial cross-bridging between contiguous villi caused much villous fusion. Epithelial cells constituting the bridges were connected by desmosomal junctions, and were continuous with the epithelial coverings of the associated villi. The lamina propria was heavily infiltrated with neutrophil leukocytes. Infected crypts in cecum and colon were dilated and devoid of mucus-secreting cells, while the ridges between crypts were hypertrophied, and the lamina propria was infiltrated by neutrophils. Cell vegetations with adherent bacteria were present in the surface intestinal epithelium of two lambs infected for 11 and 14 days, respectively. No adherent bacteria were seen in any site in lambs killed up to six days post-inoculation.

Animals↗
PubMed1982

Perinatal changes in lambs infected with Toxoplasma gondii.

Twenty-one lambs, born to ewes experimentally infected with Toxoplasma gondii during pregnancy, which were either stillborn or died soon after birth, were examined for pathological changes. In the brain perivascular cuffing by lymphoid cells and distinctive focal inflammation was widespread and common. In addition, focal leucoencephalomalacia, often associated with haemorrhages, was found in almost half the cases examined. The livers from 14 of the lambs displayed large accumulations of lymphoreticular cells in portal triads and foci of extramedullary haemopoietic cells were present in 10. Among other tissues examined the adrenal gland in 14 cases was infiltrated by eosinophils which were often associated with macrophages that contained pigment with the staining characteristics of lipofuscin. In bone marrow the myeloid-erythroid cell ratio was significantly less than that in control animals. It is concluded that intrauterine infection of the ovine fetus with T gondii causes characteristic neuropathological changes in the fetus and that anoxia due to cotyledonary damage plays a significant role in the cause of death.

Adrenal Glands↗
PubMed1981

Diarrhea in young red deer associated with infection with Cryptosporidium.

In an outbreak of diarrhea among 82 artificially reared red deer calves, 56 developed the disease and 20 subsequently died. During the outbreak 80% of diarrheal and 50% of apparently healthy calves excreted cryptosporidial oocysts in feces. The coincidence of infection with Crytosporidium and clinical diarrhea suggested a causal relationship. Histologic examination of intestinal sections from a necropsied deer calf showed lesions consistent with field and experimental cryptosporidiosis in other species. The deer Cryptosporidium subclinically infected newborn mice; in indirect immunofluorescence tests, it could not be distinguished from a calf Cryptosporidium.

Animals↗
PubMed1981

Ovine systemic pasteurellosis caused by Pasteurella haemolytica biotype T.

A detailed study was made of lambs aged 5--7 months naturally infected with Pasteurella haemolytica biotype T. In addition to the well known features of such infections, previously unreported necrotic lesions of the tonsil, oesophagus, pharynx and adjacent areas were consistently seen. Large numbers of P. haemolytica were present in the tonsil, oesophageal lesions, lung, liver and spleen, but few or none in other tissues. The evidence indicated that the disease was not a true septicaemia. It is postulated that P. haemolytica biotype T already present in the tonsils multiplies and invades the adjacent tissues of the upper alimentary tract; groups of organisms from this site enter the blood stream as emboli, most of which lodge in the capillary beds of the lung and liver; rapid multiplication of organisms in these tissues leads to death from the effects of endotoxin.

Animals↗
PubMed1981

Diarrhea in lambs: experimental infections with enterotoxigenic Escherichia coli, rotavirus, and Cryptosporidium sp.

Thirteen gnotobiotic lambs, aged from a few hours to 8 days, were inoculated orally with single infections of enterotoxigenic Escherichia coli (ETEC) (four animals), lamb rotavirus (five animals), and Cryptosporidium (four animals). Six gnotobiotic and two specific-pathogen-free lambs were co-inoculated with either rotavirus and ETEC (four animals), rotavirus and Cryptosporidium (two animals), or ETEC and Cryptosporidium (two animals). Lambs 4 days of age and older became only subclinically infected with either rotavirus, ETEC (08:K87:K99 ST+), or both enteropathogens given simultaneously. Six-day-old lambs inoculated with Cryptosporidium became extremely depressed, anorectic, and had intermittent diarrhea. There was no difference in the clinical manifestations, level of disaccharidase activity in the small intestine, or extent of histological damage between lambs inoculated with Cryptosporidium alone or together with either of the other two agents. The results indicate that under the conditions of these experiments, lambs become clinically resistant to infection with ETEC, rotavirus, or both agents together, by 4 days after birth, whereas lambs 2 days old or younger were clinically susceptible to infection by these agents. In contrast, they remained clinically susceptible to infection with Cryptosporidium up to at least 6 days of age. Cryptosporidium infections were not aggravated by coinfection with either ETEC or rotavirus.

Animals↗
PubMed1981

Diarrhea due to Cryptosporidium infection in artificially reared lambs.

Severe diarrhea which lasted 7 to 12 days occurred in 40 of 48 artificially reared lambs within 5 to 12 days of birth, and 16 of them died. Of 16 diarrheic fecal samples examined, 10 contained Cryptosporidium oocysts and 1 contained rotavirus, but no other known enteropathogen was detected. Upon histological examination, cryptosporidia were found in the ilea of three affected lambs, and in one of them, villous atrophy and fusion, with epithelial cross-bridging between villi, were present in distal small intestine. Diarrhea was induced in two specific pathogen-free lambs by oral inoculation with fecal homogenate containing Cryptosporidium oocysts. Both the small and large intestines became infected with the organism, and associated lesions included stunting, fusion, and deformities of villi in the distal small intestine, with replacement of columnar enterocytes by immature cuboidal cells. Subclinical infections were induced in newborn specific pathogen-free mice and rats. Judged by these data, the lamb-derived Cryptosporidium sp. is similar to those recovered from calves, deer, and humans.

Animals↗
PubMed1981

Diarrhea in lambs experimentally infected with Cryptosporidium isolated from calves.

Two to 5 days after oral inoculation with Cryptosporidium obtained from infected calves, 7 newborn specific-pathogen-free lambs became depressed and anorectic and developed diarrhea. Four moribund lambs were killed within 3 days after onset of illness, and the 3 other lambs died after protracted intermittent diarrhea and reduced milk intake, which lasted up to 14 days. The small and large intestines were heavily infected with Cryptosporidium, with the terminal portion of the ileum being the most severely affected. Histologic examination revealed villous atrophy, with considerable fusion and epithelial cross-bridging between villi. Lambs infected at 5 to 20 days of age had less severe clinical signs of disease, with intermittent diarrhea, reduced milk intake, and growth retardation. Lambs infected at 30 days of age became infected with the organism, but did not develop clinical signs of disease or growth retardation.

Animals↗