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Biomedical subjects

P Jakeman

Publications and source records attributed to P Jakeman.

12 recordsLinked to original sources

Trends in leprosy in the Kingdom of Bhutan, 1982-1992.

An evaluation programme was undertaken 11 years after the introduction of multidrug therapy (MDT) into Bhutan, by examining the case notes of 3239 leprosy patients who had been under treatment at any time during the period. The registered prevalence was found to have fallen markedly, as expected, and this had been accompanied by a clear fall in the case detection rate as well. The lepromatous rate among new patients rose considerably, giving epidemiological hope that the disease may be coming under control. However, no concomitant fall in the proportion of child cases was seen. The disability rate at detection rose slightly, although numbers were small. New cases were increasingly likely to have more highly positive skin smears, and to be self-reported. Programme planners should give thought to the implications of these findings.

Bhutan

The effect of alcohol on physiological tremor.

Ethanol reduces the size of essential tremor. We here show that, contrary to a recent report, ethanol also causes a large decrease in the size of physiological tremor. As in the case of essential tremor, the frequency is not changed. The reduction in tremor probably explains the well-known link between certain types of skilled activity and alcohol consumption.

Acceleration

Evaluation of a multidrug therapy programme of leprosy control.

MDT programmes for leprosy control have two objectives, controlling leprosy in populations and controlling leprosy in individuals. Evaluation of such programmes needs to address both objectives and this can be done by a review of the trends in key indicators and by site visits. Site visits are more expensive and should be done less frequently, but they can reveal issues not apparent in routinely produced statistics. Evaluation on an annual basis is the responsibility of programme managers and programme funders. Evaluation by programme staff themselves should be encouraged and supported. Evaluation of an MDT programme's effectiveness in controlling leprosy in a population should be by analysis of case detection as a proxy for incidence. Prevalence rates will continue to be monitored because of the WHO elimination goal, but these do not reflect disease transmission. Case detection is a proxy measure of incidence and depends on consistency in case detection activities. Case detection data by age, gender, mode of detection, disability ratio and lepromatous (MB) rate need to be analysed over at least 5 years and preferably 10 years to give an indication of trends in incidence. Caution is needed, however, as the pattern seen when case detection deteriorates may resemble the pattern expected when transmission is reduced. The site visit is important in this situation in allowing examination of the case detection activities, as well as in looking for new, undetected cases in the population.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent

Effect of antioxidant vitamin supplementation on muscle function after eccentric exercise.

This study investigated the effects of antioxidant vitamin supplementation upon muscle contractile function following eccentric exercise and was performed double blind. Twenty-four physically active young subjects ingested either placebo (400 mg; n = 8), vitamin E (400 mg; n = 8) or vitamin C (400 mg; n = 8) for 21 days prior to and for 7 days after performing 60 min of box-stepping exercise. Contractile function of the triceps surae was assessed by the measurement of maximal voluntary contraction (MVC) and the ratio of the force generated at 20 Hz and 50 Hz tetanic stimulation before and after eccentric exercise and for 7 days during recovery. Following eccentric exercise, MVC decreased to 75 (4)% [mean (SE); n = 24; P < 0.05] of the preexercise values and the 20/50 Hz ratio of tetanic tension from 0.76 (0.01) to 0.49 (0.03) [mean (SE); n = 24; P < 0.05). Compared to the placebo group no significant changes in MVC were observed immediately post-exercise, though recovery of MVC in the first 24 h post-exercise was greater in the group supplemented with vitamin C. The decrease in 20/50 Hz ratio of tetanic tension was significantly less (P < 0.05) post-exercise and in the initial phase of recovery in subjects supplemented with vitamin C but not with vitamin E. These data suggest that prior vitamin C supplementation may exert a protective effect against eccentric exercise-induced muscle damage.

Adolescent

A longitudinal study of exercise metabolism during recovery from viral illness.

An élite athlete engaged in a longitudinal programme of physiological assessment suffered a loss of performance that was later ascribed to an asymptomatic viral illness. In this 15-month, single subject, repeated measures study it was possible to demonstrate a severe decrease of exercise performance following viral illness. The oxygen uptake equivalent to the onset of blood lactate accumulation of 4 mmol l-1 (OBLA) decreased by 17% following viral illness, then recovered slowly, but had not returned to pre-viral levels 50 weeks later. Steady state exercise metabolism was also affected. During prolonged exercise at 70% of VO2max the proportion of energy derived from carbohydrate metabolism increased and an inability to maintain euglycaemia was observed. In both the graded and prolonged exercise tests, a pronounced tachycardia was evident after viral illness, possibly as a result of a febrile response to the infection, or, a direct effect of the virus upon myocardial performance. These data provide some preliminary and unique findings of the effects of viral illness upon the physiological and metabolic responses to exercise in an élite athlete. The data also demonstrate the sensitivity of currently used laboratory measures of exercise performance to monitor the changes in physiological function during recovery from viral illness.

Adult

Changes in plasma antioxidant status during eccentric exercise and the effect of vitamin supplementation.

Twenty-four healthy students undertook one hour of box-stepping exercise. Prior to exercise eight had received no medication (Group A), eight received 400 mg of vitamin C daily for three weeks before and one week after exercise (Group C) and eight received 400 mg of vitamin E for the same period (Group E). Groups C and E had significantly higher levels of vitamin C (p < 0.01) and vitamin E (p < 0.01) respectively than group A at the commencement of exercise. Plasma total antioxidant capacity rose significantly during exercise in all group (A - p < 0.05; C - p < 0.001; E - p < 0.001). This rise was accounted for by increases in plasma uric acid in all groups. In addition there were significant increases in vitamin C in group C (p < 0.001) and vitamin E in group E (p < 0.05). There were no significant changes in plasma malondialdehyde following exercise in any group. It is concluded that plasma antioxidant capacity rises in response to one hour of eccentric exercise and that the contribution of individual antioxidants to this change can be influenced by vitamin supplementation. The possible mechanisms of the antioxidant changes during exercise and their implications are discussed.

Adolescent

Precompetitive anxiety and motor performance: a psychophysiological examination.

Male volunteer subjects (27) completed a 5-week habituation period during which practise was undertaken on three motor performance tests. Tests were of serial reaction time, visuomotor ability and muscular power. Following stabilization of performance subjects entered an experimental period where they performed the tests before an evaluative audience on one occasion, and against a matched opponent, also before an evaluative audience on the final occasion. Preperformance measures were obtained of neuroendocrine activity, anticipatory heart rate and state anxiety. Significant precompetition elevations in state anxiety, heart rate and adrenaline levels were observed, supporting the notion that the exposure was perceived as stressful by subjects. Significant correlations were obtained between adrenaline levels and both state and trait anxiety scores. Results showed a significant increase in performance compared to habituation levels for all three tests in the audience condition. In the competitive situation against a matched opponent, performance level for the visuomotor and power tests declined significantly compared to the previous session performed before an audience. Serial reaction time performance showed a continuing upward trend, although failing to achieve significance. Changes in performance are discussed with reference to cue-utilization explanations and broader cognitive resource limitations.

Adolescent

Maximum oxygen uptake utilising different treadmill protocols.

The study compared five treadmill protocols (four utilising a motorised, and one a non-motorised, treadmill) on maximum oxygen uptake. The five male and five female subjects, all actively engaged in training, were assigned the tests in random order. Statistical analysis revealed no significant differences between the five protocols for maximal oxygen uptake, maximum ventilation, maximum heart rate and blood lactate inflection point, relative to maximal oxygen uptake. Significant differences were observed between the 3' protocol with incline increments of 1.5% and all other protocols on time to exhaustion (p = less than 0.01) and maximum blood lactate levels (HLA, p = less than 0.05). The results indicate that the protocols used in this study did not significantly influence the maximum oxygen uptake attained.

Exercise Test

Physiological changes and sleep responses during and following a world record continuous walking record.

Physiological changes, and subsequent sleep responses, were recorded in a male subject during and following 338 miles of continuous walking and consequent sleep deprivation. One hundred and thirty hours of walking and a seventy-two hours post-walk recovery period were monitored. The subject walked at approximately 55% of maximum oxygen uptake (VO2 max), heart rate ranged between 102-106 b/min, and blood lactate (LA) remained below the 2 mmol/l level. No electrocardiograph abnormalities were observed either during the walk or pre- and post-functional diagnostic graded exercise test (FDGXT). Creatine kinase (CK) and creatine kinase isoenzyme (CK-MB) levels rose throughout the walk but exhibited differing depletion patterns. The ratio of CK-MB to CK (MB/CK%) did not exceed levels which are suggestive of myocardial ischaemia. Haematological variables demonstrated signs of anaemia towards the end of the walk. Catecholamine levels rose throughout the walk, with greater rises being observed in nor-adrenaline and dopamine. During the post-walk recovery phase, adrenaline concentration remained elevated. Following this extreme period of exertion, the subject demonstrated very short sleep latency and rapid entry into slow wave sleep (SWS). These sleep patterns were compared to sleep recordings made over a similar period (72 h) six months post-walk, when the subject was not exercising. Nocturnal growth hormone (GH) levels were significantly raised on the post-walk nights.

Anemia