Acute hemodynamic responses to weightlessness in humans

As NASA designs space flights requiring prolonged periods of weightlessness for a broader segment of the population, it will be important to know the acute and sustained effects of weightlessness on the cardiovascular system since this information will contribute to understanding of the clinical pharmacology of drugs administered in space. Due to operational constraints on space flights, earliest effects of weightlessness have not been documented. We examined hemodynamic responses of humans to transitions from acceleration to weightlessness during parabolic flight on NASA's KC-135 aircraft. Impedance cardiography data were collected over four sets of 8-10 parabolas, with a brief rest period between sets. Each parabola included a period of 1.8 Gz, then approximately 20 seconds of weightlessness, and finally a period of 1.6 Gz; the cycle repeated almost immediately for the remainder of the set. Subjects were semi-supine (Shuttle launch posture) for the first set, then randomly supine, sitting and standing for each subsequent set. Transition to weightlessness while standing produced decreased heart rate, increased thoracic fluid content, and increased stroke index. Surprisingly, the onset of weightlessness in the semi-supine posture produced little evidence of a headward fluid shift. Heart rate, stroke index, and cardiac index are virtually unchanged after 20 seconds of weightlessness, and thoracic fluid content is slightly decreased. Semi-supine responses run counter to Shuttle crewmember reports of noticeable fluid shift after minutes to hours in orbit. Apparently, the headward fluid shift commences in the semi-supine posture before launch. is augmented by launch acceleration, but briefly interrupted immediately in orbit, then resumes and is completed over the next hours.

[Use of Rokitamycin dry syrup in cases of upper deep cervical lymphadenitis and otitis media with exudatives]

Dry syrup of Rokitamycin (RKM.DS), a new macrolide antibiotic with 16-membered ring developed by Toyo Jozo Co., Ltd., was used on cases of upper deep cervical lymphadenitis (UDCL) and of otitis media with exudatives (OME) likely caused by chlamydia infections, and its clinical effects were investigated. 1) In four cases of UDCL (C. psittaci infections), daily doses of 20.0-28.6 mg/kg were administered for 10-42 consecutive days and good efficacies were observed with two cases of excellent results and two cases of good results. 2) In one case of OME (C. trachomatis infection) a daily dose of 30.0 mg/kg was administered for 15 consecutive days and good effectiveness was observed. 3) No side effect was observed in any of the cases. From the above results, it became clear that RKM.DS could effectively used as a therapeutic agent for UDCL and OME in children.

GTP-binding proteins in etiolated epicotyls of Pisum sativum (Alaska) seedlings

Seven fractions of GTP-binding proteins separated by gel filtration of an extract of epicotyls of Pisum sativum seedlings were partially characterized. Seven fractions of GTP-binding proteins tentatively designated GP1 to GP7 had the capacity to be ADP-ribosylated by pertussis toxin. Pooled fractions of GP2 to GP7 showed Km values 2, 20, 50, 10, 3 and 1 nM, respectively. The binding of [35S]GTP gamma S to GTP-binding proteins was prevented competitively in the presence of 0.1 mM GTP and also prevented in the presence of 0.1 mM ATP. Binding of [35S]GTP gamma S to the proteins produced a decrease in their molecular weights.