RESUMEN
Here we describe the first neutral wind sensor developed specifically for use on resource limited nano-satellite platforms. The instrument is a next generation redesign of the ram wind sensor flown on the Communications/Navigation Outage Forecasting System satellite for measurements of neutral velocity, temperature, and composition. Results of subsystem tests in vacuum conditions show low-power operation, promising design, and good resolution of measured parameters over the operational pressure and energy ranges expected in the low Earth orbit environment.
RESUMEN
The G1 glycoprotein of Punta Toro virus, a member of the bunyavirus family, accumulates in the Golgi complex when it is expressed from cloned cDNA. We previously reported that the information necessary for Golgi retention of the G1 protein is located within the transmembrane domain and a portion of the cytoplasmic domain adjacent to the transmembrane domain (Matsuoka, Y., Chen, S.-Y., and Compans, R. W. (1994) J. Biol. Chem. 269, 22565-22573). To determine the features of the amino acid sequence motif required for Golgi retention, we have introduced mutations including truncations and point mutations in the transmembrane and the cytoplasmic domains and examined the cellular localization of the expressed mutant proteins. The results from truncation mutants indicate that the crucial information appears to be located within the first 10 amino acids of the cytoplasmic domain. Within this region, mutation of a proline residue yielded a protein that was transported to the cell surface. A protein was also expressed on the cell surface when one of the threonine residues in the transmembrane domain was changed to leucine. Thus the transmembrane domain may have a supportive role in Golgi retention, possibly by promoting protein interactions through hydroxylated side chains.
Asunto(s)
Bunyaviridae/metabolismo , Aparato de Golgi/metabolismo , Glicoproteínas de Membrana/metabolismo , Proteínas del Envoltorio Viral/metabolismo , Secuencia de Aminoácidos , Compartimento Celular , Citoplasma/metabolismo , Relación Estructura-ActividadRESUMEN
The long-term efficacy and safety of ranitidine for the prevention of duodenal ulcer recurrence were studied in two sets of double-blind, randomized, multicenter clinical trials. Ranitidine 150 mg at bedtime was compared with either cimetidine 400 mg at bedtime or placebo in the United States and Europe. To meet one of the objectives of the studies (that is, to provide a mechanism for standardizing sponsored clinical research methodology on an international basis), several features were incorporated into the study protocol. These features included identical case report forms for all trials, central clinical laboratories in the United States and Europe, monitoring of all sites to ensure that the United States style was followed, and the all sites to ensure that the United States style was followed, and the completion in the United States of all data processing and analysis. Additionally, to overcome flaws in the design of earlier trials with similar drugs, patients were examined endoscopically at more frequent intervals to detect an ulcer recurrence without symptoms, and the data were analyzed for recurrence rates by the life-table method. This method more accurately reflects the true ulcer recurrence rate than the crude-rate method that was used in earlier trials.