For many of the questions, key references are provided as a resource for those who want to further examine a particular issue.

We investigated atrial natriuretic factor (ANF) in humans, measuring plasma immunoreactive (ir) ANF (in femtomoles per milliliter), and renal, hormonal, and hemodynamic responses to ANF infusion, in normal subjects (NL) and congestive heart failure patients (CHF). Plasma irANF was 11±0.9 fmol/ml in NL and 71±9.9 in CHF (P < 0.01); the latter with twofold night ventricular increment (P < 0.05). In NL, ANF infusion of 0.10 ig/ kg per min (40 pmol/kg per min) induced increases (P < 0.05) of absolute (from 160±23 to 725±198 iseq/min) and fractional(1-4%) sodium excretion, urine flow rate (from 10±1.6 to 20±2.6 ml/min), osmolar (from 3.2±0.6 to 6.8±1.2 ml/min) and free water (from 6.8±1.6 to 13.6±1.6 ml/min) clearances, and filtration fraction (from 20±1 to 26±2%). Plasma renin and aldosterone decreased 33% and 40%, respectively (P < 0.01). Systolic blood pressure fell (from 112±3 to 104±5 mmHg, P < 0.05) in seated NL; but in supine NL, the only hemodynamic response was decreased pulmonary wedge pressure (from 11±1 to 7±1 mmHg, P < 0.05). In CHF, ANF induced changes in aldosterone and pulmonary wedge pressure, cardiac index, and systemic vascular resistance (all P < 0.05); however, responses of renin and renal excretion were attenuated. ANF infusion increased hematocrit and serum protein concentration by 5-7% in NL (P < 0.05) but not in CHF.

Juvenile (1 yr) and adult (3-5 yr) male rhesus monkeys (Macaca mulatta) and juvenile (1-4 yr) and adult (5-10 yr) male squirrel monkeys (Saimiri sciureus) were fed a diet at or near ad libitum levels based on recommended caloric intake for age and body weight or fed 30% less of the same diet with this restriction gradually introduced over a 3-mo period. Analysis of body weights among these respective control and experimental groups from the first year of the study indicated that the monkeys undergoing dietary restriction were gaining weight at a markedly slower rate compared to control values. Actual food intake among diet-restricted groups had been reduced 22-24% below control levels. Periodic analysis of hematology and blood chemistry measurements over the first year of the study detected few significant differences between control and experimental groups to indicate that diet restriction was not detrimental to general health. When values obtained from hematology and blood chemistry measurements of juvenile and adult groups (control and experimental groups combined) were compared to ad libitum fed old monkeys from each species (greater than 18 yr for rhesus; greater than 10 yr for squirrel monkeys), many significant age differences were noted. Among the largest and most consistent findings in both species were age-related decreases in concentrations of lymphocytes, serum glutamic oxalacetic transaminase, serum glutamic pyruvic transaminase, alkaline phosphatase, and phosphates as well as the albumin/globulin ratio and the blood urea nitrogen/creatinine ratio. Age-related increases in serum globulin and creatinine concentrations were also found. These parameters as well as many others being implemented in the study will be monitored further to determine if diet restriction affects the rate of development as well as aging as observed in numerous rodent studies applying such nutritional manipulations.

Patients with a diagnosis of SAH on their discharge records who initially presented through the emergency department of a hospital with a high volume of SAH cases had significantly lower mortality rates. Concentrating care for this disease in high-volume SAH treatment centers may improve overall survival.

No abstract