Significance of antibodies to the recombinant E2 protein of hepatitis G virus in haemodialysis patients.

Patients on maintenance haemodialysis represent a high-risk group for parenterally transmitted viral infections, such as hepatitis B, C and G. In addition to hepatitis G virus (HGV) (GBV-C) RNA, analysed in previous studies, we characterized the seroprevalence rates of antibodies to the putative E2 protein (anti-E2) of HGV in a German cohort of patients on maintenance dialysis (n = 72) in comparison to healthy blood donors (n = 100). The presence of anti-E2 and/or HGV RNA as indicators of present or past HGV infection could be demonstrated in 34.7% of patients and in 16% of the blood donors (P < 0.01). The infection rates with HGV seem to increase only during the first 6 years of haemodialysis. The simultaneous presence of viraemia and anti-E2 was found very rarely in patients and controls. Therefore, the emergence of anti-E2 indicates clearance of HGV viraemia. In conclusion, patients on haemodialysis are at high risk of acquiring HGV infection, but a chronic carrier state with viraemia is rare. The risk of infection is not strictly correlated with the duration of dialysis.

Validity of skinfold thickness measures of formerly obese adults.

UNLABELLED: To assess the validity of skinfold thickness estimates of body fatness in formerly morbid obese adults, 23 patients (17 women, 6 men) who had completed a protein-sparing modified fast were studied. Mean +/- SD weight loss was 60.7 +/- 20.6 kg for men and 42.6 +/- 11.5 kg for women. Body density and percent body fatness were determined after weight loss according to four commonly used skinfold equations: Pollock (P); Durnin-Rahaman (D-R); Durnin-Womersley (D-W); and, Jackson-Pollock (J-P). The validity of these measurements was assessed by hydrostatic weighing, which revealed a percent body fatness of 20.4 +/- 6.5 for men and 29.8 +/- 8.4 for women. The mean difference and total error (square root of the mean of squared deviations) between skinfold predicted and hydrostatically-determined percent body fatness for each skinfold equation were: P, 2.0 and 4.9; D-R, 4.2 and 6.6; D-W, 7.1 and 8.4; and, J-P, 0.7 and 4.4. With the exception of the latter equation, all significantly overestimated (p less than 0.01) hydrostatically-determined percent body fatness. CONCLUSION: Select skinfold equations may result in a marked overestimation of body fatness in formerly obese patients.

Physiological profile of national-class National Collegiate Athletic Association fencers.

Selected physiological characteristics of seven national-class fencers (1983 National Collegiate Athletic Association Division I champions) were studied and the results compared with those for normal persons and athletes of similar age. Evaluation included maximal oxygen uptake during arm and leg ergometry, serum lipids, body composition, and standard spirometry. Maximal oxygen uptake during arm work (34.2 mL X kg-1 X min-1) was 68% of that observed during leg work (50.2 mL X kg-1 X min-1). Mean serum triglyceride, total cholesterol, and high-density-lipoprotein cholesterol levels were 68.5, 187, and 54.5 mg/dL, respectively. Hydrostatically determined percent body fat averaged 12.2%. Results of pulmonary function studies were normal. The aerobic capacity of National Collegiate Athletic Association fencers is only slightly higher than active men of comparable age, and substantially lower than world-class endurance athletes. These data suggest that success in fencing may depend more on technique, speed, and agility as opposed to a high aerobic capacity and low percent body fatness.

Metabolic cost of extremely slow walking in cardiac patients: implications for exercise testing and training.

To assess metabolic cost of extremely slow walking, nine patients with coronary heart disease (means age, 56.1 yr) underwent multistage treadmill testing using standard open circuit calorimetry techniques. Heart rate, blood pressure, minute ventilation, and oxygen uptake in METS (1MET = 3.5 ml/kg/min) were determined at rest and at six submaximal work loads: 0.8, 1.0, 1.5, 2.0, 3.0 and 3.5mph, 0% grade. The oxygen uptake versus walking speed (0.8 to 3.5mph) relationship was y = 0.2064 (x)2 + 0.0180 (x) + 1.7260 (y = METS and x = speed in mph), r = 0.99. Results indicate that low-level exercise test protocols employing work loads between 0.8 and 2.0 mph impose similar metabolic and cardiac demands. Extremely slow walking approximates 2METS and may impose metabolic loads sufficient for exercise training in select patients with coronary heart disease.