Microalbuminuria and coronary heart disease in NIDDM: an incidence study

In most survival studies in NIDDM, microalbuminuria (urinary albumin excretion rate 20-200 microg/min) predicts early mortality; in cross-sectional studies, it is associated with coronary heart disease (CHD) morbidity. It is unclear, however, whether microalbuminuria is a risk factor for the development of CHD or the result of it, and little is known of the factors that predispose to the development of microalbuminuria in NIDDM. We examined these issues in a 7-year prospective study of a hospital-based cohort comprising 146 white NIDDM patients without clinical albuminuria. Microalbuminuria was a significant risk factor for both all-cause mortality (relative risk 3.94, 95% CI 2.04-7.62) and CHD mortality (relative risk 7.40, 95% CI 2.94-18.7) when adjusted for age only. Its independent predictive power did not persist, however, in age-adjusted multivariable survival analysis that allowed for the other significant risk factors: male sex, preexisting CHD, high levels of glycated hemoglobin, and high serum cholesterol. Among men free of CHD at baseline, the independent risk factors for CHD morbidity and mortality were microalbuminuria, current smoking, high diastolic blood pressure, and high serum cholesterol (all P < 0.05). For the 100 NIDDM patients with normoalbuminuria at baseline, the incidence of microalbuminuria was 29% over the 7-year period. In that group, fasting plasma glucose, current smoking, preexisting CHD, and high initial urinary albumin excretion rate were risk factors for the development of microalbuminuria (all P < 0.05). When men and women were analyzed separately, preexisting CHD was a significant risk factor in men only. These results demonstrate that microalbuminuria predicts incident clinical CHD in men with NIDDM. Preexisting CHD is also a risk factor for incident microalbuminuria in men, however, suggesting that microalbuminuria and CHD are not causally related but rather reflect common determinants.

In search of better route guidance instructions

Safety concerns have prompted designers of in-vehicle route guidance and information systems (IVRGIS) to make more use of an 'audible interface' to convey guidance instructions. Previous research has shown that, contrary to expectations, detailed guidance instructions can have a detrimental effect upon wayfinding performance, particularly for elderly individuals. In response to these findings a second series of experiments was carried out to try to improve the effectiveness of route guidance. Using the same procedure, 40 male and 40 female drivers aged 18-35 years watched video footage of journeys through an unfamiliar area, while hearing guidance that linked direction instructions to landmarks visible at the decision point. Results showed that those who heard these amended instructions performed significantly better than other groups at a wide range of tasks designed to measure the spatial knowledge that they had acquired. This group performed better than groups who heard nothing, and groups who heard full guidance. The results support the view that, whereas full guidance instructions can have a negative impact upon wayfinding performance, less complex instructions that link landmarks to directions have the capacity to enhance wayfinding performance. This is because instructions of this form strengthen the associations made between directions to be taken and the spatial location of these turns, resulting in the formation of a strong representation of the route. The results also showed that those who had been driving for 1 year or less were significantly less accurate at these tasks than those with more driving experience. This result has important implications for the widespread implementation and use of IVRGIS: suggesting that, for newly qualified drivers, who have not yet developed the ability to attend to and process information while controlling the vehicle, attending to route guidance instructions might have a detrimental effect upon driver safety.

Measurement of arterial oxygen-haemoglobin saturation in newborn lambs by pulse oximetry

Percentage arterial oxygen saturation (SpO2) was measured in 69 neonatal lambs at one, five and 10 minutes after birth using a pulse oximeter applied to the tail. The lambs were given a subjective vitality score from 1 to 4, with 1 being normal and 4 being stillborn. Of the 42 lambs born after a normal parturition, 19 were measured after one minute, 29 after five minutes and 24 after 10 minutes; the mean (sd) SpO2 values of these groups were 67 (15) per cent, 84 (9) per cent and 83 (9) per cent, respectively. Of the 27 lambs born after dystocia, 16 were measured after one minute, 18 after five minutes and 12 after 10 minutes; the mean (sd) SpO2 values of these groups were 61 (15) per cent, 69 (16) per cent and 69 (19) per cent, respectively. The values measured in the lambs born after dystocia were significantly lower than those in the lambs born normally at five and 10 minutes (P < 0.005 and P < 0.05, respectively). Of the lambs born with a vitality score of 1, 24 were measured after one minute, 33 after five minutes and 26 after 10 minutes; they had mean SpO2 values of 72 (11), 82 (10) and 81 (12) per cent, respectively. Of the lambs born with vitality scores of 2 or 3, 11 were measured after one minute, 14 after five minutes and 10 after 10 minutes; they had mean SpO2 values of 48 (6), 68 (17) and 72 (20) per cent, respectively. The SpO2 values of the lambs with vitality scores of 2 or 3 were significantly lower than those of the lambs with a vitality score of 1 at one and five minutes after birth (P < 0.0001 and P < 0.05, respectively).

Oesophageal injury associated with the administration of an anthelmintic bolus to calves

Six of 18 calves from a suckler herd which were dosed with a sustained-release anthelmintic bolus, using appropriate equipment, developed clinical signs related to oesophageal perforation. Two died as a direct result of the injuries sustained, one required surgical removal of the paraoesophageal bolus and the remaining three were managed medically. The calves were in the approximate weight range advised by the manufacturers as suitable for dosing, but some were younger than the minimum recommended age. These animals were of a fractious nature having been relatively little handed.

A double-blind crossover trial of atenolol, enalapril and the fixed combination of atenolol and nifedipine in mild and moderate hypertension

Sixty-three patients with mild to moderate hypertension completed a double-blind, randomised crossover trial of atenolol 100 mg daily, enalapril 20 mg daily and the fixed combination atenolol 50 mg and nifedipine retard 20 mg (Tenif) once daily. In the three areas of efficacy that the study compared-24-hour post dose blood pressure, control of blood pressure over the dosing period with particular reference to the waking day and attenuation of systolic blood pressure on exercise-atenolol and the fixed combination demonstrated greater efficacy than enalapril.

A primary demyelinating disorder of young cattle

The clinical signs and neuropathological changes are described in six Limousin X calves that, at about one month after birth, showed signs of blindness, nystagmus, rotation of the eyes, opisthotonos, hyperprotraction of the forelegs and, in one case, apparent seizures. Pathologically there was necrosis of the optic chiasma and focal areas of myelin sheath vacuolation or demyelination in certain areas of the brain, especially in the cerebellar peduncles. In one animal, kept alive for 7 months, there was remyelination by Schwann cells of some demyelinated axons in the focal cerebellar lesions, while other axons remained demyelinated. There was no evidence of oligodendrocyte remyelination. The cause of the condition was not determined but a genetic association is likely.

Cardiomyopathy in adult Holstein Friesian cattle in Britain

The clinical signs, pathology and breeding data of two cases of cardiomyopathy of an unusual kind in adult Holstein Friesian cattle in Britain are reported and compared with those in similar entities in Switzerland, Japan and Canada. The principal and primary lesions affect the heart and these produce secondary changes, particularly in the liver, and result in fatal congestive heart failure. The cardiac lesions consist of extensive myocyte vacuolation, endomysial and perimysial fibrosis and focal cardiac myocyte degeneration, atrophy and hypertrophy resulting in an extended range of myocyte size. Lesions affected all four heart chambers but were most severe in the ventricles. Vascular lesions, particularly moderate medial hypertrophy and intimal thickening of arterioles and arteries, occurred in heart, lung, kidney and lymph nodes. The liver showed severe fibrosis, chronic congestion and hepatocyte loss. There was a chronic multifocal nephritis. The cause is unknown, but the affected animals were full brother and sister and have a common ancestor in the male and female line five generations earlier.

Coronary heart disease and urinary albumin excretion rate in type 2 (non-insulin-dependent) diabetic patients

Associations between overnight urinary albumin excretion rate and prevalent coronary heart disease and its major risk factors were examined in a cross-sectional study of 141 Type 2 (non-insulin-dependent) diabetic patients. Mean albumin excretion rate was higher in men (geometric mean 13.5 micrograms/min; 95% confidence interval 10.3-17.6) than women (7.5 micrograms/min; 5.7-9.8, p less than 0.01). In diabetic men and women mean albumin excretion rate was higher in those with electrocardiographic and/or symptomatic evidence of coronary heart disease than in those without (men, 23.1 micrograms/min; 95% confidence interval 13.7-39.0 versus 10.6 micrograms/min; 7.9-14.2, p less than 0.01, women, 13.7 micrograms/min; 8.0-23.5 versus 5.4 micrograms/min; 4.2-6.8, p less than 0.01). Multiple logistic regression analysis was used to allow for confounding between variables. In the diabetic group as a whole, raised albumin excretion rate (p less than 0.001), gender (p less than 0.05) and systolic blood pressure (p = 0.06) entered the "best" model for coronary heart disease prediction. In women, albumin excretion rate alone (p less than 0.01) and in men albumin excretion rate (p less than 0.01) and age (p = 0.05) entered the "best" models. We conclude that albumin excretion rate is significantly associated with coronary heart disease morbidity after taking into account the confounding effects of raised blood pressure and other cardiovascular risk factors.

Lipid peroxidation and malondialdehyde in the synovial fluid and plasma of patients with rheumatoid arthritis

The concentration of lipid peroxides in the plasma and synovial fluid of 65 arthritic patients was determined using a new ion-pairing reverse phase HPLC technique. Patients with rheumatoid arthritis receiving only non-steroidal anti-inflammatory drugs, had a significantly higher mean concentration of lipid peroxides in synovial fluid samples (162 +/- 22.0 micrograms/l) than osteoarthritic patients (40.0 +/- 8.0 micrograms/l, p less than 0.0001). Mean concentrations in both groups correlated strongly with the level of beta-glucuronidase activity as a measure of lysosomal enzyme release (r = 0.71, p less than 0.0001). Contrary to previous reports by investigators using less specific methods, we were unable to demonstrate any increase in plasma levels of lipid peroxides in the rheumatoid patient. Treatment of rheumatoid arthritis with D-penicillamine was associated with a significant reduction of lipid peroxide levels (83.2 +/- 11.5 micrograms/ml, p less than 0.002), suggesting that this drug may function as an oxygen radical scavenger in the joint cavity. These results give further support to the concept of oxygen-free radicals playing an important role in the pathogenesis of chronic inflammatory disorders.

Quantitation of malondialdehyde (MDA) in plasma, by ion-pairing reverse phase high performance liquid chromatography

An ion-pairing high performance liquid chromatography method is described for the separation and quantitation of malondialdehyde in plasma. The MDA is determined as the thiobarbiturate chromogen formed by reaction of the plasma with 2-thiobarbituric acid under acid and heating conditions. However, under these conditions other interfering chromogens can also be formed. Using DEAE-cellulose chromatography followed by ion-pairing HPLC, we have been able to separate and quantitate the levels of MDA-TBA chromogen formed in plasma from other interfering chromogens. Measurements of MDA levels in the plasma of six normal individuals by HPLC gives a mean value of 4.57 +/- 0.33 nmole/ml, whereas the spectrophotometric determined value is 8.83 +/- 1.15 nmole/ml. These data suggest that some reevaluation of the numerous papers published on MDA levels in plasma using spectrophotometric methods may be necessary.

Persistent vaginal haemorrhage in five mares caused by varicose veins of the vaginal wall

Persistent bleeding from the vulva was the only presenting clinical sign in five non-pregnant pluriparous mares varying in age from eight to 20 years. These were two hunter types, one shire, one thoroughbred and one Arab pony. The haemorrhage originated from ulcerated varicose veins present on the dorsal wall of the vagina adjacent to the vestibulovaginal junction. All five mares were successfully treated, by submucosal resection (two), ligation of vessels (two) or diathermy (one). In four mares there was evidence of vulval incompetence caused by depression of the perineum. The importance of this and the role of impaired venous return during and after pregnancy are discussed.