ABSTRACT
The best taxonomic results were obtained in the analysis of rhizomes of 9 species and 1 variety of Smilacaceae plants grown in Zhejiang Province by using pyrolysis-high resolution gas chromatography and numerical taxonomy. When compared with the result of thin layer chromatography, it was found that those by classical taxonomy were basically reasonable, but Smilax china should be divided into two types: one with big berries and the other with small berries.
Subject(s)
Plants, Medicinal/classification , Chromatography, Gas/methods , Chromatography, Thin Layer , Cluster AnalysisABSTRACT
Protein lambda 2 of reovirus serotype 3 has been purified to homogeneity from extracts of cells infected with hybrid vaccinia virus strain WR into whose TK gene of the reovirus L2 genome segment under the control of the CPV ATI protein gene promoter had been inserted. Protein lambda 2 is formed in large amounts (final purification factor about 180) as a monomer that shows no tendency to pentamerize into the reovirus core projections/spikes. Isolated protein lambda 2 is reversibly guanylylated by GTP (that is, it carries out the GTP-PPi exchange reaction) and can transfer the -GMP moiety to GTP to form GppppG, to GDP to form GpppG, and to 5'-pp-terminated RNA to form GpppG- caps. These studies confirm previous studies on reovirus cores that indicated that protein lambda 2 is the reovirus guanylyltransferase. Protein lambda 2 possesses neither nucleoside nor RNA triphosphatase activities, nor methyltransferase activities; thus it is the reovirus capping enzyme, but provides neither the required 5'-ppG-terminated substrate nor does it methylate the cap structure. These must be functions of lambda 2 pentamers or of other individual or complexed components of reovirus cores.
Subject(s)
Mammalian orthoreovirus 3/enzymology , Nucleotidyltransferases/metabolism , Viral Core Proteins/metabolism , Animals , Chromatography, Ion Exchange , Diphosphates/metabolism , Genetic Vectors , Guanosine Triphosphate/metabolism , Kinetics , L Cells , Mammalian orthoreovirus 3/genetics , Methionine/metabolism , Mice , Molecular Weight , Nucleotidyltransferases/genetics , Nucleotidyltransferases/isolation & purification , Plasmids , RNA, Messenger/genetics , RNA, Messenger/metabolism , Thymidine Kinase/genetics , Vaccinia virus/genetics , Viral Core Proteins/genetics , Viral Core Proteins/isolation & purificationABSTRACT
To detect inapparent infection with hepatitis A virus, serial sera were collected from patients with hepatitis A and their contacts in two waterborne epidemics in China. Epidemic 1 occurred in a rural village near Hangzhou during August 1978-January 1979, and epidemic 2 took place in a rural primary school in Pinghu County in Zhejiang in April-May 1985. These sera were tested for antibodies against hepatitis A virus (anti-HAV), serum glutamic pyruvic transaminase (SGPT) activity, and icteric index. Feces also were collected in epidemic 1 to test for hepatitis A virus antigen. Both anti-HAV immunoglobulin M (IgM) and total anti-HAV were assayed in sera from "healthy persons" (symptomless persons without icterus and with normal SGPT level) who were in close contact with hepatitis A patients. In epidemic 1, among 18 "healthy persons", 12 were anti-HAV IgM positive, two were immune, and four susceptibles escaped infection. In epidemic 2, among 32 "healthy children", three were anti-HAV IgM positive, five had been infected by hepatitis A virus in the past, and 24 were not infected. These results demonstrate that inapparent infections occur along with overt and subclinical infections during epidemics of hepatitis A. The proportions of inapparent, subclinical, and overt infections were, respectively, 34.3%, 45.7%, and 20% in epidemic 1, and 25%, 50%, and 25% in epidemic 2. In addition, hepatitis A virus particles were demonstrated in the feces of all infected subjects who were examined and who included all levels of clinical response. These particles were identified with immuno-electron microscopy and enzyme-linked immunoassay.
