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Biomedical subjects

A B Vaidya

Publications and source records attributed to A B Vaidya.

At least 73 records · Page 4Linked to original sources
PubMed1982

Effect of activated charcoal on the pharmacokinetics of high-dose methotrexate.

The serum methotrexate (MTX) concentrations were estimated in two groups of patients after 6-hour iv infusion of 1 g/m2 of MTX and leucovorin rescue. One group (seven patients) received 25 g of activated charcoal orally at 12, 18, 24, 36, and 48 hours, while the other group served as a control (eight patients). Pharmacokinetic analysis revealed a significant reduction in the area under concentration curve from 18 hours until the serum MTX levels reached 10(-8) M. The MTX concentrations were significantly lower in the group that received charcoal than in the control group, at 18, 24, 36, 48, 60, and 72 hours from the end of infusion. First and second half-life values for the control and the charcoal-treated groups did not differ significantly. The data suggest that charcoal aids in the elimination of MTX from the body by interruption of the enterohepatic circulation of the drug. Activated charcoal did not cause any undesirable effects.

Adolescent↗
PubMed1980

Mycoplasmal infection of lymphocyte cell cultures: infection with M. salivarium.

Many conclusions concerning cell culture mycoplasmas are based on data from studies in fibroblast cultures. Some conclusions may not be valid in other types of differentiated cell cultures. M. salivarium was isolated from 35 human lymphocyte cultures (HLC), 34 from the same laboratory. The organism grew to more than 10(8) colony forming units (CFU) per ml of lymphocyte suspensions and was readily detectable by microbiological culture, uridine phosphorylase, and uridine/uracil assays. Direct mycoplasmal assays on HLC by DNA fluorochrome staining and scanning electron microscopy (SEM) yielded artifacts that interfered with diagnosis. For DNA and SEM of HLC, inoculation into indicator cell cultures is recommended. M. salivarium infection of HLC did not produce any immediate difference in growth rates; however, infected cultures eventually died 14 to 29 passages after infection in contrast to uninfected controls. The same organism in 3T6 fibroblasts effected a 60% decrease in growth rate. Although M. salivarium is a frequent isolate from the oral cavity, it is a rare cell culture isolate. M. salivarium was able to initiate growth over a wide pH range, grew as well in cell cultures as in cell-free media, and was resistant to 50 microgram per ml of gentamycin, tylocine, kanamycin, and erythromycin. By Cot1/2 analysis, M. salivarium had a genomic molecular weight of 4.2 X 10(6) daltons. M. salivarium did not increase chromosome aberrations in one HLC. Some of these results have application to infection of HLC by other mycoplasmal species.

Anti-Bacterial Agents↗
PubMed1979

Bioactivities and the effect of dilution on various milk-borne murine mammary tumor viruses.

Infectivity titrations of milk-borne murine mammary tumor virus (MuMTV) from different sources or prepared in different ways or stored for periods of time have been compared. Titration curves were in general reproducible for MuMTVs of different sources or handled in different ways and for different methods of measurement, such as hyperplastic alveolar nodule (HAN) development, tumor development, or MuMTV antigen secretion in third-lactation milk, The curves had characteristic shapes with a low incidence of infection at low dilutions of milk, high incidences at intermediate dilutions, and low incidences at high dilutions. Infectivity incidences were unaffected by dilution over the range 10(-2) to 10(-5). The curves did not change appreciably with time of storage of milk at liquid N2 temperature for periods up to 3 years. Rate zonal fractionation of RIII milk gave zones with bioactivities which were not proportional to B-particle content. Upon dilution, the bioactivity of Zone 3, rich in B particles, and Zone 5, poor in B particles, increased, while the bioactivity of all the other zones usually decreased with dilution. The low incidence of infection at low dilutions may have been due, in part, to an immune response of the inoculated mouse. Administration of inactivated virions 4 h prior to or with MuMTV inoculations gave some evidence in support of this hypothesis but the complexity of the bioassay system for MuMTV lends uncertainty to interpretation of results.

Age Factors↗
PubMed1977

Phase 1 tolerability and searching dose studies with 4-isothiocyanato-4'-nitrodiphenylamine (C.9333-Go/CGP 4540), a new anthelmintic.

1 Phase 1 and 2 studies were carried out in thirteen volunteers and thirty patients with hookworm anaemia with a new anthelmintic, 4-isothiocyanato-4'-nitrodiphenylamine (C.9333-Go/CGP 4540). Single and multiple doses were administered by mouth under careful supervision by the staff of the clinical pharmacology unit. 2 4-Isothiocyanato-4'-nitrodiphenylamine (C.9333-Go/CGP 4540) was well tolerated in volunteers up to a single dose of 1750 mg and in patients up to 3000 mg in divided doses. Side effects were rare, transient and mild. One patient had moderate giddiness for 24 h after the compound. The laboratory investigations did not show any adverse effects on organ functions. Transient non-specific changes in the T-wave were occasionally observed in the e.c.g. 3 Multiple doses (125 mg, 250 mg or 1000 mg X 3) of the compound were highly effective in eradicating hookworm infection, as judged by almost 100% reduction in faecal egg counts and significant recovery of parasites from 24 h stool samples. The compound also showed activity against A. lumbricoides, T. trichiura and E. vermicularis. The compound appears to be promising and more studies, in a field situation, are desirable.

Adolescent↗
PubMed1977

Clinical trials of a new anthelmintic, 4-isothiocyanato-4'-nitrodiphenylamine (C.9333-Go/CGP 4540), for the cure of hookworm infection.

A new compound, 4-isothiocyanato-4'-nitrodiphenylamine (C.9333-Go/CGP 4540), was tried in 39 hospitalized patients with hookworm infection, using several treatment schedules. At effective dose schedules (125 mg X 3 given 4-hourly; 250 mg X 3, 8-hourly; 1,000 mg X 3, 12-hourly), the egg reduction was 96% to 100%; the zero egg-counts were confirmed by coproculture for larvae. The compound was very well tolerated. Transient and mild side effects--giddiness, diarrhea and sweating--were observed in only three patients. No toxic effects were seen as judged by serial organ function tests, except a transient and mild asymptomatic elevation of transaminases in one patient.

Adult↗