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K W Angus

Publications and source records attributed to K W Angus.

At least 73 records · Page 4Linked to original sources
PubMed1980

Mesangiocapillary glomerulonephritis in lambs: the ultrastructure and immunopathology of diffuse glomerulonephritis in newly born Finnish Landrace lambs.

Renal biopsies were obtained by laparotomy from eight newborn C3 deficient Finnish Landrace lambs, and examined by light, electron and immunofluorescence microscopy. The capillaries of all glomeruli contained numerous neutrophils and peripheral capillary walls were thickened and refractile at high magnifications. Almost continuous subendothelial electron-dense deposits were seen in peripheral capillary walls. Large amounts of C'3, and small amounts of IgM and IgA were also seen in these sits. No IgG was seen in these glomeruli. Four lambs died within 96 hr of birth. The remaining four lambs all had severe clinical mesangiocapillary glomerulonephritis (MCGN) by 21 to 42 days after birth. Amounts of C'3, IgM and IgA in glomeruli had increased by comparison with amounts at birth, and IgG was present in the deposits. It was concluded that the processes ultimately expressed as MCGN in these lambs were initiated before birth.

Animals↗
PubMed1980

Ultrastructure of the small intestine in astrovirus-infected lambs.

The ultrastructure of the small intestine of gnotobiotic lambs infected with lamb astrovirus was studied. The virus was observed from 14 to 28 h p.i. in mature columnar epithelial cells covering the apical two-thirds of villi. Crystalline arrays of virus particles with a centre to centre distance of approx. 29 nm were seen in the cytoplasm and virus particles were also observed in apical pits and tubules and in lysosomes. Macrophages containing virus particles in lysosome-like organelles were seen in the lamina propria. Virus particles were released by desquamated cells disintegrating in the gut lumen. Cuboidal cells lining villi appeared from 38 to 70 h p.i., and by 120 h p.i. the villi appeared normal.

Animals↗
PubMed1980

Haemonchus contortus: attempts to immunise lambs with irradiated larvae.

Two doses of irradiated Haemonchus contortus larvae stimulated firm resistance to challenge in adult worm-free sheep but not in two-month-old lambs. Parenteral administration of larval antigens in adjuvant together with the two doses of irradiated larvae did not reduce the susceptibility of the lambs. However four doses of the attenuated larvae stimulated three of six lambs to resist the challenge. Similar concentrations of serum IgG and mucosal IgA and IgG antibodies were detected in the sheep which had been vaccinated with irradiated larvae only, regardless of their immune status. The lambs which had been injected with worm antigens had much higher levels of circulating and mucosal IgG antibodies, but mucosal IgA concentrations were similar to those in the other immunised groups. Histological examination of the abomasal mucosa did not reveal any differences between resistant and susceptible vaccinates.

Animals↗
PubMed1979

Spontaneous renal disease resembling hyperoxaluria in young lambs.

Five out of 60 purebred Suffolk lambs died when four to six weeks old with a nephrosis characterised by heavy deposits of crystals resembling calcium oxalate in the tubules. The source of oxalate was not clearly identified but may have resulted from oxalate-forming mould contamination of concentrates fed to both ewes and lambs.

Animals↗
PubMed1979

Pathogenesis of diarrhoea caused by astrovirus infections in lambs.

Experimental infection of 2-day-old gnotobiotic lambs with lamb astrovirus produced mild diarrhoea after an incubation period of about 48 hours. No other clinical symptoms developed. Infection was studied by immunofluorescent and histological examination of tissues from the lambs. Astroviruses infected only mature villus epithelial cells and subepithelial macrophages in the small intestine, where they produced partial villus atrophy. Infected enterocytes were replaced with cuboidal cells from the crypts, and the lesion gradually healed by 5 days after infection. No serological relationship was detected by immunofluorescence between lamb astrovirus antigen in gut sections and antisera to either calf or human astrovirus.

Animals↗
PubMed1979

Small intestinal morphology and epithelial cell kinetics in lamb rotavirus infections.

Morphologic changes in the small intestine of rotavirus-infected gnotobiotic lambs were investigated by measurement of villi and crypts in histologic sections of jejunum, midgut, and posterior ileum. In midgut, villus atrophy developed within 12 hr of infection and was apparent until 72 hr after infection. Crypt hypertrophy was evident from 42 hr after infection until the end of the observation period (6 days after infection). Changes in posterior ileum were similar in extent, but jejunal changes were much less marked. The relatively mild effect in the jejunum is in accord with reports from other species, and provides a basis for questioning the assumption that human rotavirus affects mainly the foregut. Studies of epithelial cell kinetics were made on midgut using a microdissection and metaphase accumulation technique on sequential samples from anesthetized lambs. An increase in the cell production rate per crypt per hour from the overall control level of 5.8 was detected by 48 hr after infection. The maximum level of 21.2 was reached 8 days after infection, and this had returned to near normal by 15 days after infection. This large and sustained increase in crypt cell production probably underlies other previously described functional abnormalities.

Animals↗
PubMed1979

Chronic infection with Trichostrongylus vitrinus in sheep. Pathological changes in the small intestine.

Eight four-month-old sheep were infected daily for 90 days with 2500 Trichostrongylus vitrinus larvae. Infections were patent by week 3; mean faecal egg counts reached a peak of 645 epg at week 5, then subsequently declined. Mean worm burden at slaughter was 6100 (range 60--25,080). Two sheep had visible lesions in the small intestine at slaughter. In both sheep, numerous shallow red depressed areas extended for 5 to 7 metres distal to the pylorus while, in one, more extensive irregular depressed areas occupied the first 1.5 metres. Microtopographical examination and scanning electron microscopy showed that these affected areas were devoid of villi and contained numerous worms embedded in the mucosa. Histological examination revealed many similarities with the lesions caused by T colubriformis. Subtotal villous atrophy and crypt elongation were present in the intestines from five of the remaining six sheep, and in these the mucosa contained numerous mononuclear cells and intraepithelial globule leucocytes.

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