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Biomedical subjects

J Hannan

Publications and source records attributed to J Hannan.

33 records · Page 2Linked to original sources

Effects of formalin footbathing on foot disease and claw quality in dairy cows.

Two experiments on the effect of routine footbathing in 5 per cent formalin in preventing foot diseases and improving claw horn quality of dairy cows are described. Treatment four times a week significantly (P less than 0.05) reduced the incidence of interdigital lesions but had no significant effect on the incidence of the individual interdigital lesions or on the incidence of individual or overall diseases of the claw horn. A two year study using a divided footbath demonstrated significant improvements in some aspects of claw quality in digits footbathed in formalin. Formalin treated digits had a lower incidence and severity of erosio ungulae (P less than 0.001) a lower moisture content (P less than 0.001) and a reduced severity of haemorrhage of the sole at some sites in the claw compared with untreated digits. Formalin treatment, however, had no significant effect on the incidence of either clinical or subclinical lesions of the claw horn. The improvement in the horn quality of claws treated with formalin for six months did not increase with a further year of treatment.

Animals↗

Ageing changes in the bovine kidney.

A study of macroscopically normal bovine kidneys from three age groups (neonatal calves, 2.5- to 3-year-old bullocks and cull cows), with no abnormalities on urine analysis, was carried out by light microscopy, immunofluorescence and electron microscopy. There was a slight increase in the proportion of involuted nephrons with increasing age but the proportion of nephrons affected was not greater than 10 per cent in any age group. In contrast to the findings of earlier workers, no evidence of diffuse proliferative glomerulonephritis was found in the material examined. It was concluded that the above techniques should be applied to the investigation of renal disease in cattle, as has already been done in man and small domestic animals.

Aging↗

Gastrointestinal flora in iron-deficient piglets.

The pH and microflora of the contents of the stomach and small intestine were studied in iron-treated and iron-deficient piglets. Compared with their iron-treated littermates, the gut contents at several sites in iron-deficient animals had a higher pH and contained greater numbers of coliforms, lactobacilli, total aerobes and total anaerobes. The possible relationship of these findings to previous findings in such animals and to their high incidence of diarrhoea is discussed.

Anemia, Hypochromic↗

Long-term effects of cold cardioplegic myocardial protection in the rat.

The long-term histologic effects of the use of two cold cardioplegic solutions (St. Thomas' and saline) were studied and compared in a model of heterotopic cardiac transplantation in rats of isogeneic strain. After cold cardioplegic arrest, hearts were stored for varying times ("minimal," 30, or 90 minutes) in one of the solution prior to transplantation, giving a total of six groups (five animals in each group). Early assessment of myocardial injury 48 hours after transplantation was by the uptake of technetium 99m pyrophosphate and by measurement of serum creatine kinase activity. Late assessment of myocardial injury at 3 months after transplantation was by quantitative histologic examination. The findings indicated that significant myocardial fibrosis occurred in hearts stored in both solutions for the longest storage period (90 minutes) and that St. Thomas' cardioplegic formula conferred better myocardial protection after 90 minutes' storage than did cold saline, as judged by the degree of histologic injury at 3 months (p less than 0.025). Significant correlation was found between long-term histologic changes at 3 months and the uptake of technetium 99m pyrophosphate (p less than 0.001) and serum creatine kinase activity (p less than 0.05) assessed at 48 hours. Uptake of technetium 99m pyrophosphate and increased serum creatine kinase activity was demonstrated 48 hours after injury in animals having no detectable histologic injury at 3 months. These observations indicate that there may be technetium 99m pyrophosphate uptake and enzyme release from reversibly damaged myocardial cells.

Animals↗

Intestinal absorption and structure in iron deficient piglets.

Absorption of D xylose by iron deficient piglets from three litters was as rapid as in their iron treated littermates, except when they were affected by diarrhoea. The dry matter content of the faeces of iron deficient piglets was marginally decreased, but the fat content of the faeces was significantly increased in two tests out of four. Diarrhoea in iron deprived piglets was associated with a small decrease in dry matter content and a large increase in fat content of the dry matter of the faeces and in fat excreted per kg bodyweight. Frank villous atrophy was evident histologically in iron deficient piglets which had diarrhoea when they were killed. Morphometric analysis of small intestinal specimens showed a significant decrease in villous length, villus-to-crypt ratio and mucosal complexity among iron deficient piglets. Crypt depth was not reduced.

Animals↗

Abattoir survey of bovine kidney disease.

A survey of the prevalence and type of renal disease was carried out at a Dublin abattoir in 1979-80. Of 4166 cattle surveyed, 173 (4.2 per cent) had kidneys rejected for gross abnormalities. The rejection rate was 7.7, 1.7, 2.2 and 28 per cent for cows, bullocks, heifers and bulls, respectively. The most common reason for rejection was focal interstitial nephritis (60.1 per cent of rejected kidneys). Other lesions included cysts (26.0 per cent), pigmentation (6.4 per cent), pyelonephritis (3.5 per cent), amyloidosis (2.9 per cent), glomerulonephritis (0.6 per cent), renal atrophy (0.6 per cent) and agonal haemorrhage.

Abattoirs↗

A study of cold cardioplegic myocardial protection in rats: an experimental model using the uptake of technetium 99m pyrophosphate and enzyme activity as parameters of injury.

This study compares the use of St Thomas' cardioplegia and cold saline cardioplegia at 4 degrees C for protection against global myocardial ischaemia in a model of heterotopic cardiac transplantation in rats of isogeneic strain. The parameters of myocardial injury applied were the uptake of Technetium 99m pyrophosphate (Tc 99m Pyp) in the transplanted heart and the measurement of serum total creatine kinase (CK) and creatine kinase MB (CK:MB) isoenzyme activity. The findings indicate that St Thomas' cardioplegic solution confers improved myocardial protection compared with normal saline as judged by statistically significant differences between: (a) the uptake of Tc 99m Pyp between the two solutions at 30 min storage: and (b) the peak total serum creatine kinase enzyme activity at 90 min storage. Excellent correlation was present between the uptake of Tc 99m Pyp and peak total serum creatine kinase activity. Further application of this model is described.

Animals↗

Gastric structure and function in iron-deficient piglets.

Gastric motility, secretion and structure were studied in piglets which were weaned at two weeks of age and reared in iron-free cages on a low-iron diet. Piglets which were not given iron parenterally rapidly developed iron deficiency anaemia. Gastric motility was studied fluoroscopically after dosing the piglets with barium sulphate. Gastric secretion was studied in piglets with gastric cannulae after stimulation with betazole hydrochloride. There was no difference between iron-treated and iron-deprived pigs in the motility of the stomach but in iron-deprived animals there was marked impairment of acid and chloride secretion from an early age and histological evidence of atrophic gastritis.

Anemia, Hypochromic↗