Plasma sodium-osmotic dissociation and hormonal interaction with drinking-induced hypervolemia at 2800 m altitude.

PURPOSE: To study hormonal factors that may account for the dissociation between beverage-induced plasma sodium p[Na+] and osmotic p[Osm] concentrations that appear to refute the high theoretical correlation between p[Na+] and p[Osm]. METHODS: Ten men (24 +/- SD 3 yr of age) sat reclining (head up) for 12 h in a chamber (21-23 degrees C dry bulb, 25-33% relative humidity) at 2800 m (9184 ft, 539 mm Hg) altitude (ALT), and at 321 m (1053 ft, 732 mm Hg) on the ground (GND). During 1000-1030 hours they consumed 3 fluids (12 ml x kg(-1),X = 948 ml x d(-1)) with large differences in sodium and osmotic contents: AstroAde (AA) with 185 mEq x L(-1) Na+ and 283 mOsm x kg(-1), Performance 1 (Shaklee) (P1) with 22 mEq x L(-1) Na+ and 365 mOsm kg(-1), or H2O at ALT; and only H2O on the GND. RESULTS: After drinking: plasma volume (PV) increased at 1200 hours by 8.3% (p < 0.05) with AA but was not significantly (NS) changed in the other sessions (Xdelta = +0.9%, range -0.9 to 2.8%); p[Na+] and p[Osm] were unchanged. Urinary rates and free-water clearances were attenuated with AA and P1 vs. those with H2O. Correlations between and among p[Na+] and p[Osm] suggest that the pNa+ ion is more tightly controlled than pOsm; and that there was no clear hormonal response that could account for this dissociation from theoretical considerations. CONCLUSIONS: There is significant dissociation between plasma sodium and osmotic concentrations after fluid intake. Induction and maintenance of hypervolemia requires increased (near isotonic) drink Na+ osmols rather than increased non-ionic osmols.

Normal T cell subsets in homosexual men living in a community without endemic AIDS.

The cause of the abnormal T lymphocyte subsets reported in healthy homosexual men is not known. Frequent sexually transmitted infections including human T cell lymphotropic virus type III/lymphadenopathy-associated virus (HTLV-III/LAV) are possible causes. To determine if the T lymphocyte subsets were abnormal in this population in an area without endemic acquired immune deficiency syndrome (AIDS), T lymphocyte subsets of 52 homosexual men in Rochester, New York, were enumerated, and evidence of infections known to cause these abnormalities was sought. Unlike the findings in previous reports, relative numbers of T helper and T suppressor cells and helper/suppressor T cell ratios were normal. Prevalence of cytomegalovirus infection (86 percent) was similar to that found in analogous populations, but only 9 percent had seropositive results for HTLV-III/LAV. Men with serologic evidence of nonprimary cytomegalovirus disease had lower helper/suppressor T cell ratios (1.5 +/- 0.2 versus 2.2 +/- 0.2; p less than 0.01). Hence, despite frequent infections with cytomegalovirus and other sexually transmitted pathogens, T cell subsets are normal in homosexual men in an area without endemic AIDS. Therefore, HTLV-III/LAV is primarily responsible for the T cell abnormalities observed elsewhere.

Vending machines and the self-care concept.

PIP: For the past 3 years (1980-83), students at the University of Rochester in Rochester, New York, have had 24-hour access to a vending machine which dispenses over the counter medicines and contraceptives. The machine is located in a small health facility near the undergraduate residence halls. The health facility is staffed by a registered nurse who provides treatment for minor illnesses, health education information, and referrals to the university's medical center. The facility stresses self-care, and a bulletin board located near the vending machine provides numerous health education brochures. The vending machine program represents a continuation of the emphasis on self-care. Instead of fostering dependency on the nursing staff the vending machine helps the students become self-reliant in reference to assessing their own health needs. Items dispensed by the machine include condoms, condoms and foam, aspirin, Sudafed, Robitussin, Acetaminiphen, Chlortrimeton, Cepacol, bandages, and thermometers. The items are sold to the students at cost. Condoms are the most popular item, and in 1982-83, 404 condom packages, priced at US$.50, were sold. Students who know what kind of medicine or health aid they want no longer are required to obtain these items by visiting the nursing staff. The image of the nurses at the facility is no longer that of a dispenser of over the counter drugs but that of someone who provides counseling, health education, and referrals. A survey conducted in 1983 revealed that the majority of the student body knew about the vending machine. This awareness reached 100% among senior class males. The purpose of the vending machine project is to make nonprescription medicines readily available to students, to make contraceptives available on a 24-hour basis, and to emphasize that the primary role of the facility's nursing staff is to provide education, counseling, and referral services.^ieng