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Biomedical subjects

J M Webster

Publications and source records attributed to J M Webster.

53 records · Page 3Linked to original sources
PubMed1974

Immunofluorescent cell-counting assay for lymphocytic choriomeningitis virus.

A quantitative assay for lymphocytic choriomeningitis virus was developed and standardized. The assay is based on direct immunofluorescent staining of infected L-929 cell monolayers and enumeration of cells containing fluorescent viral antigens. Maximal adsorption of virus to cells occurred within 1 h. Observations on the sequential development of viral antigens within cells showed that specific cytoplasmic fluorescence appeared within 10 h. The optimal time for enumerating fluorescent cells was from 18 to 20 h after addition of virus. A linear relationship was demonstrated between the number of infected cells and the relative virus concentration. Fluorescent cells were distributed randomly in infected cover slip cell monolayers. The immunofluorescent cell-counting assay for lymphocytic choriomeningitis virus was highly precise and reproducible.

Adsorption↗
PubMed1974

Neutralizing antibody response of guinea pigs to lymphocytic choriomeningitis virus.

A 24-h neutralization test that is based on fluorescent cell counting was used for the detection and quantitative determination of serum-neutralizing antibody against lymphocytic choriomeningitis virus. The earliest manifestation of serum-neutralizing antibody in guinea pigs was shown to occur within 1 week after inoculation with lymphocytic choriomeningitis virus. Within 11 weeks, serum-neutralizing antibody increased from 20- to 300-fold. Neutralizing end points of serum samples, obtained from 3 through 11 weeks, were enhanced as much as sevenfold by complement. Anti-guinea pig immunoglobulin G or anti-whole guinea pig serum potentiated the neutralizing activity of serum as much as 20- and 40-fold, respectively.

Animals↗
PubMedDate not supplied

The effect of intravenous metformin on glucose metabolism during hyperglycaemia in type 2 diabetes.

A stepped intravenous metformin infusion was used in conjunction with the hyperglycaemic clamp technique to study the dose-response relationship of plasma metformin concentration with hepatic glucose production and peripheral glucose disposal in nine patients with Type 2 diabetes. The study was of double-blind crossover design, using NaCl infusion as control. Plasma metformin concentrations spanning the therapeutic range (1.64 +/- 0.13 mg l-1 and 6.57 +/- 0.61 mg l-1) were achieved. No differences in peripheral glucose disposal were demonstrated when compared with NaCl infusion (3.4 +/- 0.1 vs 3.6 +/- 0.2 (+/- SE) mg kg-1 min-1 and 3.4 +/- 0.2 vs 3.3 +/- 0.2 mg kg-1 min-1, respectively). There was also no difference in basal hepatic glucose production during metformin and NaCl infusion (2.7 +/- 0.3 vs 2.8 +/- 0.2 mg kg-1 min-1). No acute effect of metformin on hepatic glucose production or peripheral glucose disposal was observed, implying that a chronic persistent effect is more important in these respects than immediate effects consequent upon changes in plasma drug level.

Blood Glucose↗