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To evaluate the value of signs and symptoms in children for the radiological diagnosis of acute sinusitis.

In recent UVCS/SOHO White Light Channel (WLC) observations we found quasi-periodic variations in the polarized brightness (pB) in the polar coronal holes at heliocentric distances of 1.9 to 2.45 solar radii. The motivation for the observation is the 2.5D MHD model of solar wind acceleration by nonlinear waves, that predicts compressive fluctuations in coronal holes. In February 1998 we performed new observations using the UVCS/WLC in the coronal hole and obtained additional data. The new data corroborate our earlier findings with higher statistical significance. The new longer observations show that the power spectrum peaks in the 10–12 minute range. These timescales agree with EIT observations of brightness fluctuations in polar plumes. We performed preliminary LASCO/C2 observations in an effort to further establish the coronal origin of the fluctuations.

New photographic observations of the eclipsing binary KT Hya are presented. The full extent of primary minimum is seen for the first time. New elements based on these observations are calculated, and a provisional classification of this variable's light curve as an Algol-type can be made.

Two substrains of NZB mice were developed by selective matings according to chromosome breakage frequencies in direct bone marrow preparations: HB, a line with increased chromosome breakage, and LB, a line with low or normal breakage rates. The serum of NZB mice from the HB strain contains a chromosome breaking factor that produces chromosome abnormalities in human lymphocytes. This clastogenic substance could not be detected in serum of NZB mice from the LB line. Nor does it exist in serum of Balb, C3H, C57 B1, Swiss, or AKR mice, in which no chromosomal breakage was observed in bone marrow. The breakage factor has a molecular weight between 1000 and 10,000 daltons.

Human endothelin (ET) A receptor (hETAR) is a G-protein-mediated receptor that binds ET1 with high affinity and ET2 and ET3 with lower affinities. ET1 is the most potent endogenous vasoconstrictor known at this time. When expressed in Xenopus laevis oocytes, hETAR is rapidly desensitized after stimulation with ET1. This desensitization lasts 90-110 min. Human neurokinin A (hNKAR) and human serotonin type 2 receptors were also expressed in the Xenopus system for comparison to hETAR. hNKAR desensitizes for 25-35 min, while the serotonin receptor does not appear to desensitize. To examine the role of the cytoplasmic tail of hETAR in desensitization, deletion mutations were constructed which remove 11, 36, and 51 amino acids from the cytoplasmic tail. The mutations removing 11 and 36 residues were functional, but the mutation removing 51 amino acids was not functional. The two functional mutations have a resensitization time similar to that of hETAR. In summary, the prolonged desensitization time of hETAR is unique for G-protein-mediated receptors and may attenuate the adverse physiological effects of the endothelin family. In addition, the cytoplasmic tail of hETAR does not appear to play a role in desensitization or resensitization of this receptor.

Prolonged exposure to abused drugs such as opiates causes decreased response to the drug; this reduced sensitivity is thought to be due to the loss of receptors, or down-regulation. The molecular mechanism of the opiate receptor down-regulation is not known. In order to address this, we generated a number of mutants of the delta opiate receptor COOH-terminal tail. When expressed in the Chinese hamster ovary cells, both the wild type and the receptor with a deletion of 37 COOH-terminal residues bind diprenorphine with comparable affinities and show similar decreases in cAMP levels in response to D-Ala2, D-Leu5, enkephalin (DADLE). However, the truncated receptor does not show down-regulation from the cell surface upon prolonged exposure (2-48 h) to DADLE. In contrast, both the wild type receptor and the receptor with the deletion of only 15 COOH-terminal residues show substantial down-regulation upon long term DADLE treatment. These results suggest that the region located between 15 and 37 residues from the COOH terminus is involved in the receptor down-regulation. In order to identify residues that play a key role in down-regulation, point mutations of residues within this region were examined for their ability to modulate receptor down-regulation. The receptor with a mutation of Thr353 to Ala does not down-regulate, whereas the receptor with a mutation of Ser344 to Gly down-regulates with a time course similar to that of the wild type receptor. Taken together, these results suggest that the COOH-terminal tail is not essential for functional coupling but is necessary for down-regulation and that Thr353 is critical for the agonist-mediated down-regulation of the delta opiate receptor.

The development of type 2 parainfluenza virus in HeLa and stable human amnion cells was examined by use of antisera labeled with fluorescein and ferritin. Serum containing antibody predominantly to soluble viral antigen gave specific fluorescence which was first detectable in small cytoplasmic foci 8 to 10 hr after initiation of infection. By 20 to 24 hr, when the production of infective virus and hemagglutinin was maximal, large perinuclear aggregates of fluorescence were observed which corresponded in distribution and time of appearance to the eosinophilic inclusions seen in similar preparations stained with azure eosin. The inclusions, examined by electron microscopy, were composed of fibrils, presumably viral ribonucleoprotein, which specifically bound the antibody labeled with ferritin. With antiserum to concentrated virus, on the other hand, specific fluorescence was most marked at the surface of infected cells. Foci of fluorescence at the surface represented segments of membrane which had become differentiated morphologically and antigenically to resemble the viral envelope. These were the sites where mature virions appeared. The latter exhibited marked pleomorphism; in some instances, particles were formed which lacked recognizable internal fibrils but which possessed an enclosing membrane bearing viral antigen. Filamentous forms showing an organized internal structure were also observed at the cell surface, but were never encountered in negatively stained preparations. No clear relationship between these filaments and the spherical or oval forms could be established. In negatively stained preparations, nucleocapsid released by rupture of viral particles was similar in appearance to that reported for other paramyxoviruses. It seems probable that this component has a helical configuration.

Zusammenfassung: In der vorliegenden Arbeit wird das Auftreten von Neoantigenen im Rahmen der Transformation durch SV40-Viren in Hamsterfibrosarkomzellen verfolgt. Neben den bekannten Transplantationsantigenen und dem T-Antigen im Kern konnte ein intracytoplasmatisches, bisher unbekanntes Neoantigen beschrieben und auf mikrosomaler Ebene lokalisiert werden. Aufgrund enzymchemischer Spaltungsprozesse handelt es sich dabei um wenigstens drei verschiedene Gruppen, die mglicherweise durch die Prparationstechnik aus einem Makromolekl hervorgegangen sind. Das angegebene Modell gestattet, den Antigenbestand und die Immunittslage von Tumortrgern zu studieren.

de Vaux St. Cyr, C. Columbia University, New York, N.Y.),and C. Howe. Immunochemical study of parainfluenza virus (type 2) in amnion cells. J. Bacteriol. 91:1911–1916. 1966.—Immunoelectrophoretic analysis of stable amnion cells in which parainfluenza virus (type 2) was being actively synthesized revealed at least three precipitating antigens not found in normal cells. These “new” antigens differed from viral neuraminidase and hemagglutinin in both specificity and electrophoretic mobility; their identity and function remain to be elucidated.