Showing papers by "Public Health Research Institute published in 1982"
TL;DR: Examination of sera from healthy donors aged 6 to 80 years in ATL‐endemic areas showed an age‐dependent increase of seropositive donors with a maximum of about 30% at 40 years of age, which was higher than that of healthy donors of patients with ATL.
Abstract: A nation-wide sero-epidemiologic survey of adult T-cell leukemia virus (ATLV), detected es anti-ATLA (ATLV-associated antigen), was made in Japan. Sera from adult donors in 15 different locations were screened for anti-ATLA. High incidences (6 to 37%) of antibody-positive donors were found in seven regions, one in northern Japan, and the others in southwestern regions. These areas are ATLV-endemic areas corresponding to ATL-endemic areas. Examination of sera from healthy donors aged 6 to 80 years in ATL-endemic areas showed an age-dependent increase of seropositive donors with a maximum of about 30% at 40 years of age. Anti-ATLA was found in all but two of 142 patients with ATL. Anti-ATLA-positive patients with ATL were mainly found in ATLV-endemic areas, and only a few in ATL-nonendemic areas. Six patients with cutaneous T-cell lymphoma in ATLV-nonendemic areas gave a negative reaction for anti-ATLA. The geometric mean titer of anti-ATLA of patients with ATL was higher than that of healthy donors.
593 citations
TL;DR: Results suggest the occurrence of natural plasmid transfer between staphylococci and soil bacilli, and rather unexpectedly, pBC16 is highly homologous to and incompatible with pUB110, an S. aureus plasmids specifying kanamycin resistance.
105 citations
TL;DR: The translational attenuation model is refined and extended, and both direct translational activation and kinetic trapping of a metastable active intermediate during transcription are proposed to explain basal synthesis of methylase and to rationalize the effects of certain regulatory mutants.
Abstract: ermC is a plasmid gene which specifies resistance to macrolide-lincosamide-streptogramin B antibiotics. The product of ermC was previously shown to be an inducible rRNA methylase, which is regulated translationally, and a mechanism for this regulation, termed the translational attenuation model, has been proposed. This model postulates that alternative inactive and active conformational states of the ermC mRNA are modulated by erythromycin-induced ribosome-stalling during translation of a leader peptide. In the present study the translational attenuation model was tested by constructing a series of deletants missing the ermC promoter and portions of the regulatory (leader) region. In these mutants, ermC transcription is dependent on fusion to an upstream promoter. Depending on the terminus of each deletion within the regulatory region, determined by DNA sequencing, ermC expression is observed to be either high level and inducible (like the wildtype), high level and noninducible, or low level and noninducible. The translational attenuation model predicts that as the deletions extend deeper into the leader region, successively masking and unmasking sequences required for translation of the methylase, an alternation of high and low level methylase expression will be observed. These predictions are confirmed. Based on this and other information, the model is refined and extended, and both direct translational activation and kinetic trapping of a metastable active intermediate during transcription are proposed to explain basal synthesis of methylase and to rationalize the effects of certain regulatory mutants.
64 citations
TL;DR: In this report, the Tsr mutants are shown to have primary replication defects, and the genetic complementation data are confirmed biochemically, and preliminary evidence is discussed suggesting that the pT181 replication rate is controlled at the level of synthesis of the repC protein.
Abstract: pT181 is a 4.4-kilobase plasmid from Staphylococcus aureus specifying tetracycline resistance and present in about 20 copies per cell. The existence of a diffusible pT181 product required for plasmid replication has been proposed on the basis of trans-complementable thermosensitive mutants defective in plasmid maintenance (phenotype Tsr). In this report, the Tsr mutants are shown to have primary replication defects, and the genetic complementation data are confirmed biochemically. All of five mutations are in a single cistron, the repC cistron; interruption of the plasmid DNA molecule at any of three neighboring restriction sites inactivates repC function. Analysis of the DNA sequence in this region reveals an open reading frame of 939 base pairs which encodes the repC product, a 313-amino acid protein. pT181 replication has been demonstrated in cell-free extracts to require specifically a pT181-coded protein of approximately the same size, and it is proposed that this protein is, indeed, the repC product. Preliminary evidence is discussed suggesting that the pT181 replication rate is controlled at the level of synthesis of the repC protein.
55 citations
TL;DR: Spectral data for filamentous viruses in the presence and absence of Ag+, together with other parameters, indicate that the DNA structures in two of the viruses, fd and Xf, are similar to each other but that these differ from two quite unusual and differentDNA structures in Pf1 and Pf3.
Abstract: Spectral data for filamentous viruses in the presence and absence of Ag+, together with other parameters, indicate that the DNA structures in two of the viruses, fd and Xf, are similar to each other but that these differ from two quite unusual and different DNA structures in Pf1 and Pf3.
31 citations
TL;DR: A system is described which permits the direct, positive selection of recombinant plasmids in Bacillus subtilis by inactivation of the pBD214 thy determinant by insertion of a DNA fragment, and its uses for molecular cloning are discussed.
30 citations
TL;DR: Pigs vaccinated with an attenuated Japanese encephalitis virus (JEV) vaccine and challenged with virulent JEV, either by subcutaneous injection or by exposure to infected mosquitoes, developed viremia and did transmit virus to mosquitoes which were allowed to bite them.
26 citations
TL;DR: Sedimentation coefficient and density increment values of Xf virus when combined with a value for the Xf translational diffusion coefficient are surprisingly similar, despite major differences in the DNA-protein packing between these viruses as well as fd virus.
Abstract: Measurements of the translational, DT, and rotational, DR, diffusion coefficients of Pf3 virus by low-angle polarized intensity fluctuation spectroscopy and field-free transient electric birefringence, respectively, give a length of 720 +/- 25 nm and diameter of 6.5 +/- 1.5 nm upon simultaneous solution of the Broersma equations for rigid rods. Sedimentation coefficient and density increment values obtained under solvent conditions identical with those of DT give a molecular weight of (13.4 +/- 0.8) x 10(6) g mol-1, which gives a mass per length of 18 600 +/- 1300 g mol-1 nm-1. Combining these results with the molecular weight of Pf3 DNA yields a number of protein subunits of 2500 +/- 160 and 2.38 +/- 0.14 nucleotides/protein subunit. Sedimentation coefficient and density increment values of Xf virus when combined with a value for the Xf translational diffusion coefficient [Chen, F. C., Koopmans, G., Wiseman, R. L., Day, L. A., & Swinney, H. L. (1980) Biochemistry 19, 1373] yield a molecular weight of (17.9 +/- 1.0) x 10(6) g mol-1, a number of protein subunits of 3590 +/- 230, 2.07 +/- 0.15 nucleotides/protein subunit, and a mass per length of 18 300 +/- 1200 g mol-1 nm-1. Thus, despite major differences in the DNA-protein packing between these viruses, as well as fd virus, the mass per lengths are surprisingly similar.
18 citations
TL;DR: Fiber diffraction data have been obtained for the filamentous bacteriophage Pf3 and the X-ray diffraction pattern resembles those of two other bacteriaiophages, Pf 1 and Xf, and therefore belongs to class II.
13 citations
TL;DR: In this article, a fluorimetric method for determining traces of atmospheric acrolein has been developed using molecular sieves 3A and 13X to collect the vapour and o-aminobiphenyl as the fluorescent reagent.
10 citations
TL;DR: It was found that, in addition to B cells, various T and nonT‐nonB lymphoblastoid cells responded well to Sendai virus infection to form IFN, the characterization of which has been recently reported.
Abstract: A number of human lymphoblastoid cells were examined concerning their ability to produce spontaneously liberated and virus-induced interferon (IFN). It was found that, in addition to B cells, various T and nonT-nonB lymphoblastoid cells responded well to Sendai virus infection to form IFN, the characterization of which has been recently reported (20). One B lymphoblastoid cell line from an infectious mononucleosis (IM) patient produced a large amount of IFN-alpha and might become an alternative source of IFN production. Among 68 cell lines examined, 35 cell lines liberated 10 U/ml or more of IFN spontaneously in culture fluid. The presence of Epstein-Barr virus (EBV) genome or its activation appears to have no correlation with the spontaneous liberation of IFN. Spontaneously produced IFN from three cell lines was characterized as IFN-alpha. Comparatively higher amounts of IFN were produced in cells from IM patients than those from Burkitt's lymphoma cases or healthy adults. Spontaneously produced IFN was detected more easily in cells transformed by EBV alone than in those transformed by EBV and a tumor promoter, TPA.
TL;DR: Considering the levels of these enzymes in brain and the amount of citrulline supplied via the circulation, they may play a role in the formation of arginine from citruLLine in normal brain metabolism.
Abstract: Argininosuccinase together with argininosuccinate synthetase occurs in the brain of all ureotelic species as well as in other tissuesl. Considering the levels of these enzymes in brain and the amount of citrulline supplied via the circulation, they may play a role in the formation of arginine from citrulline in normal brain metabolism.
TL;DR: Characteristics of the inactivated virion are similar to those of virions in the early stages of uncoating in HeLa cells, viz., loss of infectivity, sensitivity to proteases and detergents, change in isoelectric point, retention of intact genome, and in some instances, loss of VP4.
Abstract: Inactivation of poliovirus at subfreezing temperature in the presence of unusually low concentrations of urea (≤0.5m) was investigated. Whereas serotypes 1 and 2 are very sensitive, type 3 is resistant. Inactivation cannot be attributed to concentration of solutes since temperature must be reduced below −13°C for loss of infectivity. Characteristics of the inactivated virion are similar to those of virions in the early stages of uncoating in HeLa cells, viz., loss of infectivity, sensitivity to proteases and detergents, change in isoelectric point, retention of intact genome, and in some instances, loss of VP4. The molecular basis for inactivation is considered to be dissociation of water bound to capsid proteins thereby causing irreversible denaturation of native tertiary structure. The results of this study are discussed in terms of their relevance to the early stages of uncoatingin vivo.