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Biomedical subjects

R M Batt

Publications and source records attributed to R M Batt.

At least 73 records · Page 4Linked to original sources
PubMed1991

Effect of pancreatectomy on plasma activities of amylase, isoamylase, lipase and trypsin-like immunoreactivity in dogs.

The contribution of the pancreas to the plasma activities of amylase, isoamylase, lipase and the concentration of trypsin-like immunoreactivity (TLI) in the dog was examined by measuring the activities of these enzymes before and after total pancreatectomy. Pancreatectomy was followed by a decrease in the concentration of TLI (from 6.2 +/- 0.3 micrograms litre-1 to 1.2 +/- 0.3 micrograms litre-1; P less than 0.001) and activity of isoamylase peak 4 (from 1257 +/- 105 iu litre-1 to 894 +/- 171 iu litre-1; P less than 0.05). Though significantly reduced, the activities of peak 4 isoamylase were still within the normal range for control dogs. Pancreatectomy did not significantly alter the activities of amylase, lipase or isoamylase peaks 1, 2 and 3. These findings provide strong evidence that the pancreas is not the sole source of circulating amylase, isoamylase and lipase activities. In contrast the marked reductions in TLI to values close to the limits of assay sensitivity suggest that TLI is derived from the pancreas alone. The results indicate that assay of circulating TLI provides a more sensitive and specific indicator of pancreatic exocrine mass than plasma amylase, lipase or isoamylase activities.

Amylases↗
PubMed1991

Differential sugar absorption for the assessment of canine intestinal permeability: the cellobiose/mannitol test in gluten-sensitive enteropathy of Irish setters.

Intestinal permeability was assessed in Irish setters with gluten-sensitive enteropathy by oral administration of an isotonic solution of cellobiose and mannitol, and measurement of their urinary excretion ratio. The cellobiose/mannitol ratio was increased in affected Irish setters fed a wheat-containing diet compared both with littermates reared on a cereal-free diet, with no evidence of jejunal damage, and clinically healthy Irish setters. The ratio fell following six weeks on a gluten-free diet to be comparable with control values, and subsequently increased after six weeks gluten challenge. The results indicate that the cellobiose/mannitol test may be useful for the detection of mucosal damage and for monitoring the response to therapy.

Animals↗
PubMed1991

Relative IgA deficiency and small intestinal bacterial overgrowth in German shepherd dogs.

Serum immunoglobulin concentrations and densities of IgA-producing immunocytes in intestinal mucosa were compared in a group of clinically healthy dogs of various breeds, a group of clinically healthy German shepherd dogs, and a group of German shepherds with bacterial overgrowth in the proximal small intestine. Serum concentrations of IgA, but not IgM or IgG, were significantly lower in the clinically healthy German shepherd dogs than in other purebreed and mixbreed dogs, indicating that production of IgA by gut-associated lymphoid tissue might be relatively low in this breed. However, densities of IgA-producing cells were not significantly different comparing these two groups, suggesting that any impairment of mucosal IgA production is more likely to be related to defective synthesis or secretion of IgA than to reduced numbers of IgA-producing immunocytes. Comparable findings in German shepherd dogs with small intestinal bacterial overgrowth provided further indirect evidence that local immunity might be defective in this breed, since these luminal bacteria would be expected to stimulate mucosal IgA production. However, it is not clear whether such a defect is directly responsible for the overgrowth, or whether there is an indirect relationship between defective local immunity and bacterial overgrowth in German shepherd dogs.

Animals↗
PubMed1991

Incidence of common DNA sequences in bovine and porcine Escherichia coli strains causing diarrhoea.

Seventeen bovine and 56 porcine Escherichia coli isolates from cases of diarrhoea and from healthy animals were examined for DNA sequences homologous to the genes for verocytotoxins (VT), enterotoxins and human enterohaemorrhagic E coli/enteropathogenic E coli (EHEC EPEC) sequences. VT-1 was the most common toxin among the bovine isolates and VT-2 the most common in the porcine isolates. No isolates had homologous sequences to enteropathogenic adherence factor, but 71.2 per cent hybridised to the DNA probe encoding specific EHEC sequences, and 95.9 per cent showed homology with a 23 kb DNA fragment common to EHEC and EPEC plasmids.

Animals↗
PubMed1991

The prevalence of enteric pathogens in diarrhoeic thoroughbred foals in Britain and Ireland.

A survey of 77 normal and 326 diarrhoeic foals in Britain and Ireland from 1987 to 1989 revealed a significantly higher prevalence of Group A rotaviruses and Aeromonas hydrophila in diarrhoeic foals. The prevalence of cryptosporidia, potentially pathogenic Escherichia coli, Yersinia enterocolitica and Clostridium perfringens was similar in normal or diarrhoeic foals. Rotaviruses had a similar prevalence in all age groups of scouring foals up to three months of age, with an overall prevalence of 37 per cent among diarrhoeic foals. The number of cases of diarrhoea varied considerably from year to year, but in all three years of the survey rotavirus was a significant pathogen. A comparison of diagnostic tests for rotavirus in the faeces showed electron microscopy (EM) and polyacrylamide gel electrophoresis (PAGE) to have similar sensitivity. The Rotazyme ELISA test kit was found to have the same sensitivity as a combination of EM and PAGE. A. hydrophila had an overall prevalence of 9 per cent among diarrhoeic foals, although its prevalence was higher in some age groups. A. hydrophila has not been established previously as a significant enteric pathogen in foals. Other putative pathogens found at very low prevalence were coronavirus, the putative picobirnavirus, Campylobacter spp. and Salmonella spp. No evidence was found of synergistic effects between rotavirus, cryptosporidia and potentially pathogenic E. coli. Neither coccidia nor non-Group A rotaviruses were found in any of the samples examined.

Aeromonas↗
PubMed1991

Abnormal permeability precedes the development of a gluten sensitive enteropathy in Irish setter dogs.

Intestinal permeability to 51Cr-EDTA was examined during the development of gluten sensitive enteropathy in dogs bred from affected Irish setters and reared on a normal wheat containing diet. Comparisons were made with litter mates reared on a gluten free diet and with a control group of age matched, clinically healthy Irish setters reared on the normal diet. Studies at 4, 6, 8, and 12 months of age were correlated with morphometric and biochemical examinations of peroral jejunal biopsy specimens. Permeability was increased at all ages in the group fed gluten free diet compared with control dogs, although there were no differences in villus height, intraepithelial lymphocyte density, and alkaline phosphatase activity. At four months, permeability in the normal diet group was greater than in controls, although comparable with that in the gluten free diet group. Permeability in the normal diet group increased further in conjunction with the development of partial villus atrophy and reduced alkaline phosphatase activity, and by 12 months permeability was significantly greater than in their gluten free diet litter mates and the control dogs. The findings suggest that an underlying permeability abnormality may be involved in the pathogenesis of gluten sensitive enteropathy in Irish setter dogs.

Alkaline Phosphatase↗
PubMed1990

Enhanced intestinal permeability to 51Cr-labeled EDTA in dogs with small intestinal disease.

Intestinal permeability in dogs with small intestinal disease was measured by quantitation of 24-hour urinary excretion of 51Cr-labeled EDTA following intragastric administration. Permeability was high in dogs with a variety of naturally acquired small intestinal diseases including wheat-sensitive enteropathy of Irish Setters, small intestinal bacterial over-growth, and giardiasis, and permeability was decreased after successful treatment. These findings indicate that the assessment of intestinal permeability may be a useful technique for detecting small intestinal disease and for monitoring the efficacy of treatment in dogs.

Animals↗
PubMed1990

Cellular localization of intrinsic factor in pancreas and stomach of the dog.

A cobalamin (vitamin B12)-binding protein has recently been identified in canine pancreatic juice which is biochemically, immunochemically and functionally similar to canine gastric intrinsic factor. However, the cellular sources of both this pancreatic intrinsic factor and gastric intrinsic factor in the dog are not known. Antisera raised against canine gastric intrinsic factor have been used to examine the distribution of intrinsic factors in the canine pancreas and stomach. Immunoreactivity was demonstrated in duct cells but not acinar or endocrine cells in the pancreas, and in fundic peptic and pyloric gastric pit cells in stomach. All immunostaining was abolished by preabsorption of the antisera with purified canine gastric and pancreatic intrinsic factors. A cellular source of pancreatic intrinsic factor has not been previously described, and the demonstration of intrinsic factor-like immunoreactivity in two cell types in the canine stomach contrasts with its localization in a single cell type in the gastric mucosa of other mammalian species. Furthermore, immunoreactivity in pancreatic duct cells was detected at much higher dilutions of antisera than those required for staining of peptic and gastric pit cells. This suggests a higher concentration of antigen, and supports previous evidence that the pancrease is a major source of intrinsic factor in the dog.

Animals↗
PubMed1990

Attaching effacement of the rabbit enterocyte brush border is encoded on a single 96.5-kilobase-pair plasmid in an enteropathogenic Escherichia coli O111 strain.

An enteropathogenic Escherichia coli (EPE) O111 serotype a,b,H- strain carried the following four plasmids: pLV501 (96.5 kilobase pairs [kbp]) specifying resistance to chloramphenicol, tetracycline, and kanamycin; pLV502 (8 kbp) specifying ampicillin resistance; pLV503 (1.9 kbp) specifying streptomycin resistance; and pLV504 (80 kbp) with no resistance markers. This EPEC attached to HEp-2 cells to produce localized clumps of bacteria (localized adhesion) and attached intimately to the enterocyte surface, leading to loss of the brush border (attaching effacement). Plasmid pLV501 was also found to specify the ability to produce localized adhesion on HEp-2 cells and attaching effacement in a rabbit ileal explant model system. Restriction maps showed considerable dissimilarities between pLV501 and pMAR-2, an EPEC plasmid carrying the EPEC adherence factor (EAF) genes. Furthermore, pLV501 did not hybridize with the EAF probe, whereas pLV504 did. There was sequence homology between pLV501 and large plasmids in all seven other well-characterized EPEC, only five of which hybridized with the EAF probe. These findings indicate that pLV501 carries at least one of the genes responsible for production of the brush border damage characteristic of EPEC.

Animals↗
PubMed1990

Development of wheat-sensitive enteropathy in Irish Setters: biochemical changes.

Biochemical changes in the small intestine during development of naturally acquired wheat-sensitive enteropathy of Irish Setters were investigated. To distinguish primary biochemical abnormalities from secondary effects of intestinal damage, progeny of affected dogs reared on a normal wheat-containing diet were compared with their own littermates reared on a cereal-free diet and with age-matched clinically normal Irish Setters fed the same wheat-containing diet. Peroral jejunal biopsy specimens were sequentially obtained between weaning and 1 year of age; specific activity and reorientating sucrose density-gradient distribution of organelle marker enzymes were determined. Major primary biochemical abnormalities were not detected in affected progeny. In affected dogs fed wheat, there was a selective, but secondary, loss of the brush border alkaline phosphatase and aminopeptidase N activities. This loss was associated with the development of partial villus atrophy, but represented a specific effect of dietary wheat on the brush border, not merely a nonspecific effect of mucosal damage, because other brush border enzymes, including disaccharidases, were not similarly affected. Increased soluble activities of lysosomal and peroxisomal marker enzymes late in the disease process may represent alterations in these 2 organelles as a secondary consequence of mucosal damage.

Alkaline Phosphatase↗
PubMed1990

Effects of exocrine pancreatic insufficiency and replacement therapy on the bacterial flora of the duodenum in dogs.

The influence of pancreatic secretions on the bacterial flora of the small intestine in 6 dogs was investigated by determining effects of exocrine pancreatic insufficiency on numbers and types of bacteria in duodenal juice, and by examining the subsequent response to dietary supplementation with bovine pancreatic extract. Exocrine pancreatic insufficiency was induced by ligation of pancreatic ducts and was confirmed by indirect assessment of exocrine pancreatic function. Duct ligation was followed by large increases (P less than 0.01) in total numbers of bacteria, reflecting increased numbers particularly of Lactobacillus spp and Streptococcus spp, in 3 dogs accompanied by obligate anaerobes. Total numbers of aerobes and anaerobes decreased markedly (P less than 0.05) after supplementation with bovine pancreatic extract to values that were not significantly different from those determined before duct ligation. Exocrine pancreatic insufficiency therefore resulted in small intestinal bacterial overgrowth that was reversed by pancreatic replacement therapy, indicating that pancreatic secretions can have an important influence on the small intestinal bacterial flora of dogs.

Animals↗
PubMed1990

Development of wheat-sensitive enteropathy in Irish Setters: morphologic changes.

Morphologic changes in the small intestine were investigated during development of naturally acquired wheat-sensitive enteropathy in Irish Setters. To distinguish underlying morphologic abnormalities from nonspecific effects of intestinal damage, progeny of affected dogs reared on a normal wheat-containing diet were compared with their own littermates reared on a cereal-free diet and with age-matched clinically normal Irish Setters fed the same wheat-containing diet. Peroral jejunal biopsy specimens were taken sequentially between 4 months and 1 year of age. At 4 months of age, there were no differences in villus height, comparing the 3 groups, but increased numbers of intraepithelial lymphocytes and goblet cells were already present in biopsy specimens from the affected Irish Setters fed wheat. Dietary wheat resulted in a progressive reduction in villus height in the jejunum of affected Irish Setters from 6 months onward. Underlying morphologic abnormalities were not found, and the characteristic morphologic changes of this enteropathy were secondary to the presence of dietary wheat. However, development of partial villus atrophy was preceded by increased numbers of intraepithelial lymphocytes and goblet cells.

Age Factors↗