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Biomedical subjects

A Pani

Publications and source records attributed to A Pani.

At least 55 records · Page 3Linked to original sources
PubMed1987

Characterization and role in morphogenesis of a new subviral particle (55S) isolated from poliovirus-infected cells.

A previously undetected subviral particle, designated the 55S particle because of its position in sucrose density gradients, has been found in cytoplasmic extracts of poliovirus-infected cells. It contains no RNA, is composed of equimolar amounts of the structural polypeptides P1AB, P1C, and P1D, and is stable in vitro under a variety of conditions: presence or absence of EDTA, dilution in low- or high-ionic-strength buffers, suspension in buffers up to pH 10, incubation at 37 degrees C, and centrifugation to equilibrium in CsCl gradients (where it bands at a density of 1.285 g/cm3). Conventional pulse-chase experiments show that 55S particles are the products of the assembly of 14S subunits and the precursors of virions. These data led to the formulation of a model of poliovirus morphogenesis in which the conversion of capsomers into 73S empty capsids does not occur directly, but through the formation of an intermediate structure, the 55S particle.

Cell Line↗
PubMed1986

A kinase able to phosphorylate exogenous protein synthesis initiation factor eIF-2 alpha is present in lysates of mengovirus-infected L cells.

Infection of mouse L929 cells by mengovirus resulted in the expression of a kinase activity that selectively phosphorylated the small, 38,000-molecular-weight subunit of eucaryotic initiation factor 2 and histone H2. This kinase activity was independent of host cell RNA synthesis and was located in the postribosomal supernatant (S-100 fraction) early after infection (up to 3 h). At later times after infection (5 h), kinase activity was also associated with the polysome fraction. The kinase present in the S-100 fraction bound strongly to DEAE-cellulose, its peak activity eluting at 0.5 M KCl. Kinase activity was independent of the presence of exogenous double-stranded RNA, and KCl at concentrations greater than 0.1 M inhibited eucaryotic initiation factor 2 phosphorylation. The 67,000-molecular-weight phosphoprotein activated in interferon-treated cells by double-stranded RNA was not detected by standard phosphorylation assays in lysates from mengovirus-infected cells. Labeling of this protein in vivo during 5 h of infection was also not detected. The DEAE-cellulose-purified mengovirus kinase inhibited protein synthesis in reticulocyte lysates, and the inhibition was not reversible by high concentrations of poly(I).poly(C).

Animals↗
PubMed1983

Variation in resistance of cells from inbred strains of mice to herpes simplex virus type 1.

By several criteria, replication of herpes simplex virus type 1 (HSV-1) in primary cell cultures from inbred strains of mice resistant (R) to this virus was less than in cultures from susceptible (S) strains. The difference was not obviously related to less efficient adsorption, to more efficient production of interferon or to a larger number of lysosomes. Except at high multiplicities of infection, cells from the F1 progeny of a cross between an R and an S strain replicated virus as well as cells from the S parent; this contrasts with strain-related resistance to intraperitoneal inoculation in vivo, which is inherited as a dominant characteristic. It is suggested that diminished ability of structural cells to replicate HSV-1 may contribute to resistance in the intact animal.

Animals↗
PubMed1981

Poliovirus morphogenesis. I. Identification of 80S dissociable particles and evidence for the artifactual production of procapsids.

The current model of poliovirus morphogenesis postulates a fundamental role for procapsid, 80S shells that, upon interaction with viral RNA and subsequent proteolytic cleavage, give rise to complete virus particles. Although 80S sedimenting particles can, indeed, be isolated from cytoplasmic extracts of infected cells, their physical properties differ from those reported for procapsids. Far from being stable structures, they can be dissociated by pH 8.5 and 0.1% sodium dodecyl sulfate into slower-sedimenting subunits. The reasons for this discrepancy were investigated, and two main modalities leading to the appearance of procapsids in vitro were identified. The first involves a temperature-mediated conversion of dissociable 80S particles into stable 80S procapsids, and the second involves the self-assembly of endogenous 14S subunits, also primed by an increase in the temperature of cytoplasmic extracts.

Capsid↗
PubMed1979

Glycyrrhizic acid inhibits virus growth and inactivates virus particles.

Screening investigations in antiviral action of plant extracts have revealed that a component of Glycyrrhiza glabra roots, found to be glycyrrhizie acid, is active against viruses. We report here that this drug inhibits growth and cytopathology of several unrelated DNA and RNA viruses, while not affecting cell activity and ability to replicate. In addition, glycyrrhizic acid inactivates herpes simplex virus particles irreversibly.

Antiviral Agents↗
PubMedDate not supplied

Combined treatment with steroids and azathioprine in IgA nephropathy: design of a prospective randomised multicentre trial.

Corticosteroids have had variable success in IgA nephropathy (IgAN). Our previous trial with a six-month course of steroids in IgAN patients showed they were effective in reducing the risk of renal function deterioration and proteinuria, but this effect seemed to decrease in the long term. This new randomised trial was designed to prospectively evaluate whether adding low-dose azathioprine to steroids improves long-term renal survival in adult biopsy-proven IgAN patients with proteinuria > or = 1 g/24 h and plasma creatinine < or = 2.0 mg/dl. The patients will be treated with steroids (methylprednisolone 1 g i.v. for three consecutive days at months 1, 3 and 5, plus oral prednisone 0.5 mg/kg every other day for six months) plus azathioprine 1.5 mg/kg/day for six months or steroids alone with the same schedule. Altogether a minimum of 346 patients should be enrolled within a four-year recruitment period. The planned duration of follow-up is five years.

Adolescent↗