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Biomedical subjects

R Ray

Publications and source records attributed to R Ray.

At least 253 records · Page 14Linked to original sources
PubMed1980

Lower limb anomalies in the thrombocytopenia absent-radius (TAR) syndrome.

We report a case of the TAR syndrome with severe abnormalities of the lower limbs. The syndrome of thrombocytopenia and radial deformities occasionally presents diagnostic difficulties when severe limb anomalies are present. Based on this case and 2 additional cases from the literature, reduction anomalies of the lower limbs should be considered part of the TAR syndrome.

Female↗
PubMed1979

Failure of serology in diagnosing chlamydial infections of the female genital tract.

Chlamydia trachomatis was recoved from 20% (36/180) of women attending a venereal disease clinic. All infected women had chlamydial antibodies in their serum and cervical secretions. However, the background rates of chlamydial antibody in chlamydia-negative women were very high. Measurement of antibodies in serum (complement fixation or immunoglobulin G [IgG] and IgM by microimmunofluorescence) or cervical secretion (IgG, IgM, IgA or secretory IgA classes) did not result in predictive values of greater than 32%. It is concluded that the detection of chlamydial antibodies in serum or cervical secretions cannot be substituted for agent isolation in diagnosing these infections.

Antibodies, Bacterial↗
PubMed1978

Psychosocial correlates of chronic cannabis use.

The psychosocial effects of chronic heavy use of cannabis were studied in a rural population of males in north India. The user group comprised thirty persons who had been taking only cannabis at least 11 times a month over a period of five years or more. The controls were fifty subjects selected from among the general population to which the users belonged. The controls had not been using any drugs. The subjects had similar age distribution, occupation, socioeconomic status, and educational background. Psychosocial adaptation was assessed by enquiries into such areas as self-aspiration, present occupation, occupational satisfaction, marital status, marital relationships, sexual behaviour, self-reported deviant behaviour, and future planning for children. On no variable were the present users found to be different from the non-user control group.

Adult↗
PubMed1977

The incidence of cervical cancer and duration of oral contraceptive use.

In a prospective study carried out on a cohort of 17,942 women belonging to the Kaiser Foundation Health Plan and living in suburban communities of the San Francisco Bay Area, a positive association was found between the incidence of cervical carcinoma and total duration of oral contraceptive use. The association was established while controlling for the effects of age, education, and selected infections. The association persists when incident cases of dysplasia are added to those of carcinoma. A further study, in which covariates relating to sexual behavior will also be taken into account, is in progress.

Adolescent↗
PubMed1976

Interactions of neurotoxins with the action potential NA + ionophore.

Four neurotoxins that activate the action potential Na+ionophore of electrically excitable neuroblastoma cells interact with two distinct classes of sites, one specific for the alkaloids veratridine, batrachotoxin, and aconitine, and the second specific for scorpion toxin. Positive heterotropic cooperativity is observed between toxins bound at these two classes of sites. Tetrodotoxin, a specific inhibitor of the action potential Na+ current, inhibits activation by each of these toxins in a noncompetitive manner (KI=4-8 nM). These results suggest the existence of three functionally separable components of the action potential Na+ionophore: two regulatory components which bind activating neurotoxins and interact allosterically in controlling the activity of a third ion-transport component, which binds tetrodotoxin. The dissociation constant for scorpion toxin binding is increased 10-fold by depolarization of the cells with K+, suggesting that the scorpion toxin binding site is located on a voltage-sensitive regulatory component of the ionophore.

Aconitine↗
PubMed1976

Membrane potential dependent binding of scorpion toxin to action potential Na+ ionophore.

Depolarization of neuroblastoma cells causes a 70-fold increase in the apparent dissociation constant KD for scorpion toxin enhancement of activation of the action potential Na+ ionophore by veratridine and a large increase in the rate of reversal of scorpion toxin action. Depolarization also inhibits binding of 125I-labeled scorpion toxin to a small number of saturable binding sites on electrically excitable neuroblastoma cells and increases the rate of dissociation of scorpion toxin from these sites. The results suggest that scorpion toxin binds to a regulatory component of the action potential Na+ ionophore whose conformation changes on depolarization.

Action Potentials↗