Potential Functions of Plasma Prorenin; Regional Activation and Tissue Extraction

The fate of circulating inactive prorenin was examined in patients and volunteers. Prorenin was activated either by acid-dialysis with warming at pH 3.3 or with trypsin. The results were similar but omission of warming reduced the value by 13%. In 6 volunteers, 20 min forearm venous occlusion raised regional total (T) and inactive (I) plasma renin concentration (PRC) by 51% and 48% without change of active (A) renin. During intense foream exercise the ratio APRC:IPRC did not change in muscle or skin venous blood. Body anaerobic exercise increased APRC 3.7-fold without change in IPRC. These procedures activate plasminogen but are without effect on prorenin. In 18 patient with stable angina, TPRC was lower in coronary sinus than arterial blood (p<0.001) but APRC was not affected. A-V differences were not detected across the leg. Prorenin is apparently stable in the circulation but extracted by the heart.     

Hemodynamics in Childhood Hypertension

Children with elevated systolic blood pressure have a wide range of cardiac output. We investigated the mechanisms regulating resting and exercise blood pressure in 264 children who were selected from the low, middle, and upper quintile of the distribution of blood pressure of an entire school population. We identified patterns of response to exercise that correlated both with resting cardiac output and resting blood pressure. During isometric exercise, systolic blood pressure adjusted for age and body size increased in all groups. The low group mean pressure remained significantly lower than the high group's pressures throughout the entire exercise period. Body size adjusted group systolic and diastolic blood pressure level differences existed during dynamic exercise. The product of the systolic blood pressure times the heart rate in the high blood pressure group was significantly higher throughout dynamic exercise than in the other two groups. Elevated resting resistance was correlated with elevated resistance during isometric exercise and elevated diastolic blood pressure during dynamic exercise. Cardiac index had a significant negative correlation to age (r=-0.58) at all levels of blood pressure. This observation, in children, lends some support to the concept of evolution from a hyperkinetic circulation in early childhood to a circulation with lower cardiac output and more elevated systemic vascular resistance at an older age.     

Urinary Albumin Excretion during Exercise in Juvenile Diabetes a Provocation Test for Early Abnormalities

Urinary albumin excretion during exercise was measured with a radioimmunological method in a group of 13 young male diabetic patients and in a comparable control group. The duration of diabetes was 2–18 years; they had no proteinuria (Albustix®) and no other signs of renal disease. There was no difference in the basal albumin excretion. In the diabetics the average albumin excretion was doubled during exercise at 600 kpm/min for 20 min, from 9.1 μg/min to 18.7 μg/min (P<0.005). No significant change was seen in the controls. These results strongly suggest that abnormal glomerular filter properties are present in patients with relatively short duration of diabetes that is, in patients who are known to have thickened glomerular basement membrane. The exercise provocation test may be useful in other fields of renal pathophysiology.     

Increased Blood Oxygen Affinity and Physical Work Capacity in Man

Influence of altered blood oxygen affinity on work performance in man was investigated. Increased in vitro blood oxygen affinity was achieved in vivo by partial DPG depletion induced by 70 hours of acidosis followed by acute restoration of acid-base balance by intravenous NaHCO₃. Work performance tests with determination of submaximal and maximal oxygen uptake were performed at the two different DPG levels. Submaximal and maximal oxygen uptake remained unchanged when DPG decreased from 0.80 to 0.58 mol/mol Hb and P_{50 (7.4. BE=0)} (oxygen tension at half saturation of hemoglobin) decreased from 26.4 to 24.0 mm Hg. Thus a small increase of in vitro whole blood oxygen affinity does not impair work performance in man.     

Elder Abuse

The detection, treatment and prevention of elder abuse, although of concern to health care professionals, has not received over the past several years the attention it merits. While social service and health care dollars for elders decline or are redistributed, elder abuse may be on the upswing. As physical and occupational therapists move into home health care settings they are in opportune positions to detect instances of elder abuse and facilitate remedial or preventive services. This article reviews the current problem of elder abuse and describes some roles for the allied health professional in addressing the need.     

Exercise intervention and health checks for middle-aged men with elevated cardiovascular risk: A randomized controlled trial

Abstract

Objective. To study the effects of a health check by a nurse alone or combined with an exercise intervention in middle-aged men at increased cardiovascular risk. Design. A randomized controlled trial. Setting and intervention. Primary care in Kirkkonummi municipality with 36 000 inhabitants. A health check by a nurse alone or combined with an exercise intervention to controls with no intervention was compared. Subjects. A total of 168 men aged 35 to 45 years with at least two cardiovascular risk factors and physical activity (PA) frequency < 3 times a week. Main outcome measures. Metabolic syndrome (MetS) as defined by International Diabetes Federation/American Heart Association and self-reported PA frequency. Results. Overall, focusing on health increased physical activity frequency in middle-aged men. After one year, 19% had increased PA to ≥ 3 times a week (95% CI 12–26). All study groups increased PA to ≥ 3 times: 26% of men in the exercise intervention group, 15% of men in the health check group, and 16% of controls. The differences between the groups were not statistically significant. The intervention did not have any meaningful impact on MetS or other cardiovascular outcomes at one-year follow up. Conclusions. Physical activity increased in all study groups of middle-aged men in this health-promotion trial. The interventions had no effect on metabolic syndrome or other cardiovascular outcomes in the participants. The trial increased awareness and collaboration in physical activity promotion among municipal health care and exercise services.