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Cardiac autonomic function was studied in 23 alcohol dependent men by standard tests of autonomic function and measurement of 24 hour heart rate variability. In all there was peripheral or central nervous system damage or both. Standard tests of autonomic function showed vagal neuropathy in seven. The remainder had normal autonomic function tests. Twenty four hour heart rate variability was measured as the standard deviation of the successive differences between RR intervals from an ambulatory electrocardiogram recording. Twenty four hour heart rate variability was significantly lower in both alcohol dependent groups than in controls, but the results in the two alcohol dependent groups were not significantly different from each other. The results of standard tests of autonomic function did not distinguish between the alcohol dependent men with normal autonomic function and controls. The differences in heart rate variability between this group and the controls may have been the result of the ability of this method to detect small changes in autonomic integrity. Cardiomyopathy may also account for some of these differences and such abnormalities should be excluded before results are to be regarded as a reflection of vagal function. Twenty four hour measurement of heart rate variability may be a more useful index of cardiac vagal neuropathy than currently available tests of autonomic function. activity but this does not take into account that inputs of different frequencies produce the change in heart rate; those at lower frequencies are not necessarily autonomic in origin such as reflex mechanisms involved with continuing haemodynamic changes. Tests of autonomic function also tend to classify patients merely on the basis of the presence of neuropathy and give little scope for grading its severity.5 Measurement of short term (5 min) heart rate variability has been advocated as an indicator of autonomic neuropathy6; however, there is disagreement about whether the recording should be performed with the patient standing, sitting, or lying and about the best index for measuring heart rate variability.7 Ambulatory electrocardiographic (Holter) monitoring of heart rate variability may provide a more sensitive index of autonomic function than is currently available8 because it makes a large number of RR intervals available for the calculation of heart rate variability. Monitoring over 24 hours also provides an opportunity to examine autonomic function during normal daily activities without interference from investigators. It may enable disease progression in alcohol dependent patients to be monitored. Ewing and colleagues reported that heart rate variability was reduced in diabetic patients who had normal standard autonomic function tests.8 The present study was conducted to test whether similar results apply to alcohol dependent patients and whether 24 hour measurement of heart rate variability is a useful method for assessing cardiac autonomic changes in alcohol dependent patients.

Predicting epidemics of plant virus disease constitutes a challenging undertaking due to the complexity of the three-cornered pathosystems (virus, vector, and host) involved and their interactions with the environment. A complicated nomenclature is used to describe virus epidemiological models. This review explains how the nomenclature evolved and provides a historical account of the development of such models. The process and steps involved in devising models that incorporate weather variables and data retrieval and are able to forecast plant virus epidemics effectively are explained. Their application to provide user-friendly, Internet-based decision support systems (DSSs) that determine when and where control measures are needed is described. Finally, case studies are provided of eight pathosystems representing different scenarios in which modeling approaches have been used with varying degrees of effectiveness to forecast virus epidemics in parts of the world with temperate, Mediterranean, subtropical, and tropical climates.

Iron taken after elective hip or knee replacement surgery does not result in higher haemoglobin 10 weeks after surgery, or a faster rate of increase in haemoglobin than a control treatment.

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