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Biomedical subjects

G Mathew

Publications and source records attributed to G Mathew.

At least 55 records · Page 3Linked to original sources
PubMed1994

Evaluation of 2% sodium fluoride iontophoresis as an alternative to lining in Class I cavity preparations--an in vivo study.

The study carried out on 110 permanent teeth in 44 randomly selected patients with age ranging from 8-14 years, to evaluate the efficacy of 2% sodium fluoride iontophoresis as an alternative to cavity lining in Class I preparations. 65 teeth were included in the experimental group (2% sodium fluoride iontophoresis) and 4 teeth in the control group (Zinc phosphate linings). Sensitivity gradings were done on a subjective discomfort scale. From the results, it was found that after cavity preparation, all the teeth (100%) were sensitive to air blast, water jet and probing in varying severity. But after iontophoresis and amalgam restoration the sensitivity reduced to 4.6%. Six months and nine months follow up revealed that all the teeth were vital and asymptomatic.

Adolescent↗
PubMed1993

Response to antituberculous chemotherapy after splenectomy.

A case of a 17-year-old Indian male with disseminated tuberculosis is reported. While on chemotherapy, he was detected to have splenic abscesses. The patient remained unresponsive to antituberculous drugs until a splenectomy was performed.

Abscess↗
PubMed1993

Handedness in mental handicap: investigation into populations of Down's syndrome, epilepsy and autism.

The handedness in three randomly sampled groups of people with learning disabilities consisting of patients with Down's syndrome, epilepsy, and autism were studied using a validated instrument. All subjects were controlled for neurological and other medical disorders. A statistically significant increase in left-handedness and ambiguous handedness compared with the general population was found in all groups. There was no significant difference in the rate of left-handedness between the three groups.

Adult↗
PubMed1992

Methyl parathion-induced sperm shape abnormalities in mouse.

Metacid 50, the commercial grade of methyl parathion (O,O-dimethyl-O-4-nitrophenyl phosphorothionate), a commonly used organophosphorus insecticide, was tested for its genotoxicity in Swiss albino mice using the sperm abnormality assay. Sperms of albino mice were examined at two time intervals, 1 week and 5 weeks after a single acute oral treatment with the pesticide at four dose levels, viz., 75.0, 37.5, 18.75 and 9.375 mg/kg body weight corresponding to 1/2 LD50, 1/4 LD50, 1/8 LD50 and 1/16 LD50 values respectively. A dose-related statistically significant increase in the percentage of abnormal sperm observed indicates the genotoxic potency of methyl parathion.

Animals↗
PubMed1990

In vivo genotoxic effects in mice of Metacid 50, an organophosphorus insecticide.

The genotoxic effect of methyl parathion, an organophosphorus insecticide commercially available as Metacid 50, was studied in Swiss albino mice using bone marrow and peripheral blood micronucleus tests. Single acute oral doses of the insecticide at concentrations of 75.0, 37.5, 18.75 and 9.375 mg/kg body weight, equivalent to 1/2 LD50, 1/4 LD50, 1/8 LD50 and 1/16 LD50, administered to female mice, elicited positive responses in bone marrow and peripheral blood micronuclei tests. Statistically significant increases in the frequency of micronuclei were observed at higher doses in both the tests performed. The data obtained for our experiments suggest that methyl parathion is a potent mutagen and so it is also likely to have a genotoxic effect in humans.

Animals↗
PubMed1977

The use of equilin as an internal standard to quantitate estriol in pregnancy urine.

The assay of pregnancy urine estriol by gas chromatography is most often carried out by adding cholesterol as an internal standard at the end of the extraction procedure. The reason for this is that cholesterol does not contain a phenolic ring, and would be lost during the extraction procedure for estriol. This does not allow for corrections of recovery loss, which would be the case if the internal standard was a phenolic steroid. This paper describes the utilization of equilin (delta 1,3,5,7-estratetraen-3-01-17-one) as the internal standard. The sample is hydrolyzed to remove sulfate and glucuronide groups and then the equilin is added. If equilin is added before hydrolysis, variable destruction takes place. Derivative studies indicate that room temperature silylation can be used with bis (trimethylsilyl)-trifluoroacetamide/trichlorosilane/trimethylsilylimidazole, 3:3:2 by weight. Results on control material containing a low, critical pregnancy concentration of estriol were as follows--listed value 5.0 mg/1, found 5.3 mg/1, co-efficient of variation %, 8.9% for 17 runs on different days.

17-Ketosteroids↗
PubMed1975

Chemosterilant (apholate)-induced ultrastructural changes during oogenesis in Aedes aegypti.

The effect of chemosterilant, apholate, on-oogenesis has been studied in Aedes aegypti. Treatment of larvae to 20 ppm of the chemical induced ultrastural changes in the presumptive and primary follicles of the adult ovary. These changes comprised condensation of chromatin, disruption of nuclear envelope and extensive degeneration as evidenced by numerous myelin figures and residual bodies. In some primary follicles, where cellular degeneration was restricted to epithelial cells, no arrest in development was observed. However, in comparison with controls, these follicles also were retarded. Larval treatment with 30 ppm apholate completely supressed ovariolar development. High incidence of autophagy was observed in tissues at both dose levels.

Aedes↗