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Biomedical subjects

B P Sagik

Publications and source records attributed to B P Sagik.

11 recordsLinked to original sources
PubMed1979

Method of soil column preparation for the evaluation of viral transport.

A method for packing soil columns to investigate viral transport phenomena is described. The columns were 10 cm in diameter and ranged from 33 to 100 cm in length. Field conditions of the soil, including bulk density and profile, were reproduced in columns. Ionic gradients resulting from sequential applications of wastewater and distilled water affected the movement of poliovirus I (Chat) through soil. Compared with 33-cm- and 66-cm-length columns, lower concentrations of infectious virions were observed in the percolates from 100-cm soil columns. These results may be attributed to the greater pore volume in the longer columns (the greater volume of soil contained in these columns), whereas the volume of liquid applied was constant for all columns.

Microbiological Techniques↗
PubMed1979

Procedure for the recovery of airborne human enteric viruses during spray irrigation of treated wastewater.

Because of the relatively low number of indigenous enteric viruses recovered from secondary wastewater effluents, their presence in air (aerosols) as a result of wastewater spray irrigation requires extensive sampling. Methodology to allow the recovery of indigenous enteroviruses from aerosols generated at an operational wastewater irrigation site was tested under both laboratory and field conditions.

Aerosols↗
PubMed1979

The effect of membrane-active agents on Sindbis virus morphogenesis.

In chicken cells infected by Sindbis virus and exposed to a variety of membrane-active compounds, virus release was inhibited. In infected cells exposed to antiserum directed against the virion glycoproteins E1 or E2, retinol, cortisone, Pb++ or insulin, the processing of two Sindbis virus precursor polypeptides which lead to the formation of virion polypeptides was inhibited. The B-protein, which is the precursor to both envelope proteins, accumulated in cells treated by these compounds. This precursor is generally not detected in chicken cells, presumably because it is processed rapidly. The cleavage of the precursor PE2 to the envelope glycoprotein E2 was also inhibited. E2 was also absent in cells exposed to menadione or to antiserum prepared against uninfected chicken cells. Since each of the compounds tested interfered with Sindbis virus polypeptide cleavage, despite their diverse mechanisms of action, it suggests that perturbation of normal membrane fluidity can interfere with Sindbis virus budding.

Animals↗
PubMed1977

Interaction of Sindbis virus glycoproteins during morphogenesis.

In cells infected with the Sindbis temperature-sensitive mutants ts-23 and ts-10 (complementation group D), which contain a defect in the envelope glycoprotein E1, the precursor polypeptide PE2 is not cleaved to the envelope glycoprotein E2 at the nonpermissive temperature. This defect is phenotypically identical to the defect observed in the complementation group E mutant, ts-20. The lesion in ts-23 is reversible upon shift to permissive temperature, whereas that of ts-10 is not. Antiserum against whole virus, E1, or E2 also prevents the cleavage of PE2 in cells infected with wild-type Sindbis virus. Because the cleavage of PE2 is inhibited by the lesion in mutants that are genotypically distinct and by anti-E1 or -E2 serum, it appears that PE2 and E1 exist as a complex in the membrane of the infected cell.

Cell Membrane↗
PubMed1977

Virus-directed post-translational cleavage in Sindbus virus-infected cells.

The viral polypeptides synthesized in cells coinfected with group C and group D or E Sindbis virus mutants were studied. Cleavage of the ts2 protein occurs in cells coinfected with ts2 and ts20. Since the ts2 protein fails to chase in cells infected with ts2 alone, the activity effecting this cleavage must be, at least in part, virus specified.

Animals↗
PubMed1976

Genetic exclusion and stable complementation of Sindbis virus.

In an effort to enhance genetic interactions by eliminating spatial or physical barriers between variants of Sindbis virus MgCl2 was used to aggregate infecting viral particles. Mixing viral samples in a 1:1 ratio with 0.5 M MgCl2 produced maximal reduction in plaque forming units (PFU) with minimal cell damage due to MgCl2. Aggregate size was determined to be about 7 PFU. Samples taken at 3,5 and 10 hours after infection with mixed aggregates composed of large and small plaque forming virus indicated that only one type of genome was represented among the progeny particles. In addition, aggregation enhanced complementation and the progeny were stable after several cycles of sonication and passage.

Culture Techniques↗
PubMed1976

Poliovirus survival and movement in a sandy forest soil.

Movement of poliovirus I (Chat) through nonsterile core samples of a sandy forest soil was monitored, using several regimens of loading with either dechlorinated final effluent from an operating activated sludge treatment plant or distilled water. Stimulated cycles of rainfall and effluent applications, resulting in ionic gradients, were shown to affect virus movement. Such studies indicate that poliovirus applied in effluents may move considerable distances through this soil after rainfall. Survival of poliovirus in the soil at 4 and 20 C has been monitored for 84 days. During this period, the capacity of the virus to migrate is unchanged.

Hydrogen-Ion Concentration↗
PubMed1975

Association of enteroviruses with natural and artificially introduced colloidal solids in water and infectivity of solids-associated virions.

Encephalomyocarditis viruses adsorb to introducted organic and inorganic solids in water over a wide range of pH and with various concentrations and species of metal cations. Visible flocculation of solids was not a prerequisite for significant virus association. Virus adsorption to natural solids in various types of natural waters was significant but variable. Clay-adsorbed virus retained its infectivity in tissue culture monolayers. These solids-associated viruses also retained infectivity in mice.

Adsorption↗