Bioelectrical impedance analysis in the measurement of the body composition of surgical patients

The evaluation of nutritional status in surgical patients remains a difficult problem. Bioelectrical impedance analysis (BIA) is a new method of body composition analysis which is easily performed at the bedside. This study determined the accuracy of BIA in the measurement of total body water (TBW) and potassium (TBK) in a heterogeneous group of surgical patients. The resistance and reactance components of impedance were measured with a whole body impedance analyser. Tritiated water dilution and whole body monitoring were the reference methods for TBW and TBK analysis. With the BIA technique the coefficient of variation for the estimation of TBW was 8.1 per cent and for TBK was 6.4 per cent. Allowing for the errors of the reference methods these results show that BIA is of limited value in the estimation of TBW but may provide a useful index of TBK.

The effect of isoprinosine and levamisole on factors relevant to protection of calves against respiratory disease

Experiments to characterize the effects of two immunomodulators, namely, isoprinosine and levamisole, on factors relevant to the resistance of calves to respiratory infection were undertaken. Daily oral doses of isoprinosine decreased the influx of neutrophils into the respiratory tract, increased membrane immunoglobulin and complement receptor expression on cells from bronchoalveolar lavage samples and decreased the severity of respiratory disease. Additional intravenous doses produced similar effects on neutrophil migration to the respiratory tract and on membrane receptor expression, but the changes were no greater than those seen with oral isoprinosine alone. No significant changes in the anti-bacterial activity of cells in bronchoalveolar lavage samples followed isoprinosine treatment. In vitro incubation of pulmonary alveolar macrophages harvested from normal calves with isoprinosine increased their expression of immunoglobulin and complement receptors. Levamisole did not affect neutrophil migration to the lower respiratory tract or membrane receptor expression by pulmonary alveolar macrophages after in vivo or in vitro treatment. The immunomodulatory effects of isoprinosine beneficially increase the resistance of calves to respiratory disease, and are potentially useful in the control of infectious diseases of farm animals.

Calibration of a prompt neutron activation analysis facility for the measurement of total body protein

Prompt neutron activation analysis with 252Cf has been used to measure total body protein. Since simultaneous irradiation and detection generated a high count rate at the detectors the nucleonic system was optimised to reduce distortions in the gamma ray energy spectrum. Tissue-equivalent phantoms were used to calibrate the apparatus. A total of 53 studies was performed on 39 normal subjects. Ratios of total body protein to fat-free mass agreed well with those from other centres and with cadaver studies. Duplicate measurements of 14 subjects gave a coefficient of variation of +/- 2.9% for a measurement of total body protein, which is close to that calculated from the known errors of the technique of +/- 2.7%. The whole body dose equivalent was 0.17 mSv.

Factors responsible for the introduction and spread of Campylobacter jejuni infection in commercial poultry production

Campylobacter jejuni and related thermophilic campylobacters were not found in a hatchery or in chicks aged less than seven days. However, an increasing proportion of chicks aged two weeks and older shed campylobacters in their droppings. It was shown that a likely source of C jejuni for young chicks was the environment in the immediate vicinity of the rearing houses, and that infection could readily be introduced on the footwear and clothing of farm staff. Thermophilic campylobacters were found in the air, litter and drinking water containers in the rearing and finishing houses.

Absorbed dose from 14C xylose and 14C mannose

Tissue distribution and excretion studies have been performed in rats and mice for up to 1 week after oral administration of 14C xylose and 14C mannose. The effective dose-equivalent is calculated to be 15 microSv/MBq for xylose and 120 microSv/MBq for mannose. Since there was no clearance of mannose during the period of the study, the effective dose-equivalent for mannose is almost entirely dependent upon the assumptions made about expected lifetime exposure.

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.

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.

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.

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.

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.

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.

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.

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.