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Biomedical subjects

M G Varma

Publications and source records attributed to M G Varma.

At least 37 records · Page 2Linked to original sources

Cytopathic effect and plaque formation by arboviruses in a continuous cell line (XTC-2) from the toad Xenopus laevis.

Forty-six arboviruses were tested for c.p.e. and/or plaque formation in an amphibian cell line. C.p.e. was observed with a high proportion of the viruses tested. Comparative plaque assay, in the XTC-2 cells at 28 degrees C and Vero cells at 37 degrees C, suggests that these systems are comparable in sensitivity and susceptibility to infection. Practical uses of this cell line are discussed.

Animals↗

Infection of an Aedes aegypti cell line with infectious arbovirus-antibody complexes.

Aedes aegypti cells exposed to infectious complexes of WN or YF virus and homologous antiserum produced lower yields of virus over a 10-day observation period than were produced by Aedes aegypti cells treated with a comparable dose of virus mixed with non-immune serum. When Ae. aegypti cells were infected with WN virus mixed with MVE, NTA, DEN-2 or YF antisera the virus yield over 10 days was lower than in cell cultures infected at similar titres with mixtures of WN virus with non-immune serum. If Ae. aegypti cell cultures were infected with mixtures of YF virus and WN or DEN-2 antiserum the resulting production of virus was lower over 10 days than in virus mixed with non-immune serum. Human serum samples from the field were tested for the presence of antibody by preincubation of the serum with WN virus prior to inoculation on to mosquito cell cultures. The results indicated that this method is as sensitive in detecting antibody as a mouse neutralization test using regression analysis of average survival time.

Aedes↗

Infection of the mosquito Aedes aegypti with infectious West Nile virus-antibody complexes.

Aedes aegypti fed through chick skin membranes on West Nile virus-homologous antiserum mixtures shown by an anti-globulin neutralization test to be highly infectious complexes (in terms of plaque formation in tissue culture) failed to become infected. Control mosquitoes fed on West Nile virus--normal rabbit serum mixtures containing similar or smaller amounts of infectious virus were shown to become infected. Mosquitoes ingesting suspensions of West Nile virus previously incubated with Murray Valley encephalitis or Ntaya antiserum became infected at significantly lower rates (P = less than 0-05) than controls ingesting West Nile virus-normal rabbit serum mixtures. West Nile virus--17D yellow fever or dengue--2 antiserum mixtures did not produce significantly reduced infection rates in Ae. aegypti when compared to controls.

Aedes↗