The two surface glycoproteins S and HE of human coronavirus OC43 (HCV-OC43) were isolated from the viral membrane and purified. Only the S protein was able to agglutinate chicken erythrocytes, indicating that this viral protein is the major hemagglutinin of HCV-OC43. The receptor determinant recognized by this virus on the surface of erythrocytes is N-acetyl-9-O-acetylneuraminic acid (Neu5,9Ac2) which is also used by bovine coronavirus for attachment to cells. By analyzing erythrocytes containing different amounts of Neu5,9Ac2 in either of two linkage types, it was found that there are subtle differences in the affinity of both viruses for 9-O-acetylated sialic acid. Bovine coronavirus was more efficient in recognizing low amounts of Neu5,9Ac2 alpha 2,3 linked to galactose, whereas HCV-OC43 was superior with respect to the alpha 2,6 linkage. The gene coding for the S protein of HCV-OC43 was cloned and sequenced. A large open reading frame predicts a polypeptide of 150 kDa in the unglycosylated form. A protein of about 190 kDa is expected if the 20 potential glycosylation sites are used for attachment of N-linked oligosaccharide side chains. These predictions were confirmed by in vitro transcription and translation of the gene in the presence or absence of canine pancreatic microsomal membranes. A high degree of sequence homology was found between the S proteins of HCV-OC43 and bovine coronavirus. Structural and functional analyses of more strains should help to identify the location of the sialic acid-binding site.

The receptor-binding activity of strain CU (grown in MDCK I cells) and of strain VA (adapted to Vero cells) of human coronavirus OC43 was analyzed and compared with the binding activity of bovine coronavirus (BCV) and of the OC43 strain provided by the American Type Culture Collection (AT). Results obtained with resialylated erythrocytes indicated that the ability of the viruses to recognize 9-O-acetylated sialic acid in an alpha 2,6-linkage decreased in the following order: AT > CU > BCV > VA. Only minor differences were observed with respect to the alpha 2,3-linkage. The amino acid sequence of the S protein of strain CU and VA was derived from the nucleotide sequence of the cloned gene. Strain VA differed from strain CU in 34 positions, 18 in the S1 and 16 in the S2 subunit.

During the epidemic outbreak in the region of Greifswald in the winter 1974/75, we found influenza virus variants which showed differences in the electrophoretic mobility of HA. Among the 25 isolates 13 were of slower and 12 of higher mobility. HA1 of 6 isolates was studied by determining the number of the carbohydrate side chains and by direct sequencing of vRNA. Evidence is presented that variants showing a slower electrophoretic mobility of HA1 had consistently acquired a seventh carbohydrate side chain at Asn 126 in epitope A. All the isolates differed from the reference strain A/Port Chalmers/1/73 by the loss of the oligosaccharide at Asn 81. The field strain A/Dresden/3/71 possessed only 5 oligosaccharides in HA1. These results suggest that changes in glycosylation are an important mechanism in the structural variation underlying antigenic drift of HA.

The crystal structures of PbMe3I and BiPh2Cl have been determined by X-ray methods. Both compounds form polymeric chains via bent μ2-halogeno bridges and almost linear X-M-X units (X = I, Cl).PbMe3I: Space group P212121, Z = 2; lattice dimensions at -50 °C: a = 653.0(1), b = 1034.0(2), c = 1124.5(2) pm, R = 0.049.BiPh2Cl: Space group P42, Z = 4; lattice dimensions at -50 °C: a = b = 847.5(2), c = 1644.9(4) pm, R = 0.044

Background Public health systems and services research (PHSSR) examines the organization, financing, and delivery of public health services and the impact of these activities on population health. An accurate description of this PHSSR is needed to empower funding agencies and other stakeholders, to coordinate PHSSR activities, and to foster the development of the field. Purpose To characterize the emerging community of researchers engaged in PHSSR. This study 1) describes dynamics of this growing community; and 2) identifies distinct topics being researched, communities of practice within PHSSR, and collaboration among groups. Methods Co-authorship network visualization of selected research publications in the Medline bibliographic database. Results PHSSR has emerged gradually since 1988, with noticeable growth after 1994 and after 2004. The network of PHSSR research has a core-periphery structure. The core of this network includes highly collaborative researchers focusing on topics pertaining directly to PHSSR, such as the public health workforce, quality improvement and performance, law, and information infrastructure. The periphery consists of groups publishing either more generally on various health services research topics, or on epidemiologic, clinical, or health sciences topics. Conclusions While a nucleus group of productive and engaged individuals participate in PHSSR, most authors are also involved in general health services research, issues of population health, or health science topics unrelated to PHSSR. An overview of collaboration in PHSSR is an important step in advancing a coordinated research agenda and attracting sustainable funding streams for this field.