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E Rieder

Publications and source records attributed to E Rieder.

30 records · Page 2Linked to original sources
PubMed1994

Sequence of the S fragment of foot-and-mouth disease virus type A12.

The foot-and-mouth disease virus (FMDV) genome contains a 5' untranslated region (S fragment) capable of forming a stem-loop structure of over 350 bases, which is separated from the remainder of the genome by a homopolymeric cytidylic acid tract (poly(C)) of variable length. The sequence of the S fragment of serotype A12 appears more similar to those of type O1 or type C3 than to subtype A10. The relatively large difference between the S fragment sequences of two type A viruses suggests that the sequences per se of this region of the genome are not critical for the maintenance of function, and suggests the possibility of a relatively recent recombination event within the poly(C) region of the A12 genome.

Amino Acid Sequence↗
PubMed1994

Vaccines prepared from chimeras of foot-and-mouth disease virus (FMDV) induce neutralizing antibodies and protective immunity to multiple serotypes of FMDV.

The G-H loop of VP1 (residues 132 to 159) of foot-and-mouth disease virus (FMDV) is a prominent feature on the virion surface and has an important role in vaccine efficacy, generation of antigenic variants, and cell binding. Using an infectious cDNA of FMDV, we have constructed serotype A viruses in which the G-H loop has been substituted with the homologous sequences from serotype O or C. These chimeric viruses replicated to high titer and displayed plaque morphologies similar to those of wild-type viruses, demonstrating that the functions provided by the loop can be readily exchanged between serotypes. Monoclonal antibody analyses showed that epitopes contained within the loop were transferred to the chimeras and that epitopes encoded by the type A backbone were maintained. Chemically inactivated vaccines prepared from chimeric viruses induced antibodies in guinea pigs that neutralized both type A and either type O or type C viruses. Swine inoculated with the A/C chimera vaccine also produced cross-reactive antibodies, were protected from challenge with the type A virus, and partially protected against challenge with type C. These studies emphasize the importance of epitopes outside of the G-H loop in protective immunity in swine, which is a natural host of FMDV.

Amino Acid Sequence↗
PubMed1994

Animal-derived antigenic variants of foot-and-mouth disease virus type A12 have low affinity for cells in culture.

We recently have shown that binding of foot-and-mouth disease virus (FMDV) to cells in culture requires an arginine-glycine-aspartic acid (RGD) sequence in the G-H loop of the capsid protein VP1 (P. W. Mason, E. Rieder, and B. Baxt, Proc. Natl. Acad. Sci. USA 91:1932-1936, 1994). In this report, we show that FMDV type A12 viruses found in infected bovine tongue tissue (BTT) differ from their tissue culture-grown derivatives at amino acid residues near the RGD. Viruses genetically engineered to contain VP1 sequences found in animal tissue (BTT viruses) were antigenically different from their tissue culture derivatives and bound to BHK cells more poorly than did the tissue culture-adapted viruses. Passage of the genetically engineered BTT viruses in BHK cells resulted in the rapid selection of variants with cell-binding properties, antigenic characteristics, and sequences typical of tissue culture-adapted viruses. These data indicate that residues near the RGD are critical for cell binding and that interpretations of antigenic variation of FMDV can be affected by virus cultivation in vitro.

Amino Acid Sequence↗
PubMed1993

Genetically engineered foot-and-mouth disease viruses with poly(C) tracts of two nucleotides are virulent in mice.

To determine the role of the poly(C) tract found at the 5' end of the genome of foot-and-mouth disease virus, synthetic RNAs (in vitro transcripts) with poly(C) tracts of different lengths have been produced and evaluated. RNAs with poly(C) tracts of 35, 25, 16, 6, or 2 residues displayed similar specific infectivities in baby hamster kidney (BHK) cells. Viruses recovered from cells transfected with in vitro transcripts containing 6 to 35 Cs had properties similar to those of the wild-type virus in cell culture, and poly(C) tracts present in the synthetic RNA-derived viruses ranged from 75 to 140 bases in length. Viruses recovered from transcripts containing only two Cs showed very different properties. Specifically, viruses grew to much lower levels in cell culture and maintained a poly(C) tract of only two residues. The pool of viruses harvested from cells transfected with the synthetic C2 RNA also contained a small amount of a virus with a 42-base deletion in the region of the poly(C) tract, which appeared to have arisen by recombination. Taken together, these data suggest that recombination provides the mechanism of poly(C) elongation and that viruses with poly(C) tracts over 75 bases in length have a selective advantage in cell culture. Interestingly, all of the in vitro transcript-derived viruses [including viruses with poly(C) tracts of only two residues] were equally virulent in mice, indicating that poly(C) tract length has no effect on virulence in this animal model.

Animals↗
PubMed1984

Is loxapine more effective than chlorpromazine in paranoid schizophrenia?

The authors compared loxapine with chlorpromazine in inpatients with paranoid schizophrenia and found no difference in clinical efficacy. Thus a previous finding, based on retrospective analyses, that loxapine was superior to other neuroleptics in the treatment of paranoid schizophrenia was not verified in this prospective study.

Adolescent↗
PubMed1980

Autoradiographic localization of carbonic anhydrase in the developing chorioallantoic membrane.

Carbonic anhydrase was localized in the chorioallantoic membrane with labeled inhibitor autoradiography of 3H-acetazolamide at 11, 14 and 19 days of incubation. At 11 days carbonic anhydrase was present in low amounts only in the undifferentiated ectoderm cells. At 14 and 19 days, the enzyme was found in increased amounts in all three germ layers of the chorioallantois. In the chorionic ectoderm the villous cavity cells contained the highest level of carbonic anhydrase. This finding lends support to the theory of H+ production to solubilize the CaCO3 of the egg shell. Sinus covering cells showed a considerable lower concentration of the enzyme than did villous cavity cells. Carbonic anhydrase in these cells may be multifunctional, assisting in calcium transport, subserving HCO3- transport from egg shell to blood, and supporting gaseous exchange. In the allantoic endoderm carbonic anhydrase was found in granule-rich cells and might be involved in the transport of Na+ and Cl- ions from allantoic fluid into the blood. The enzyme in the undifferentiated endoderm cells may have a respiratory function. In the mesoderm carbonic anhydrase was detected in the endothelium and pericytes of blood vessels where it is interpreted to support respiratory function.

Allantois↗