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Biomedical subjects

A M Marshall

Publications and source records attributed to A M Marshall.

At least 19 recordsLinked to original sources
PubMed1989

Measurement of nuclear oestrogen receptors in human breast tumours.

Recent reports suggest that oestrogen receptors detected in the cytosolic fraction of homogenized human breast tumours might be mainly nuclear receptor released into the cytoplasm during tissue processing. This study thus compares the tumour content of steroid hormone receptors in conventional cytosolic receptor assays with direct measurements of receptor in the cell nucleus. Unoccupied cytoplasmic oestrogen receptors (cER), cytoplasmic progesterone receptors (cPR) and total (occupied plus unoccupied) nuclear oestrogen receptors (nER) have been measured in parallel in human breast tumour tissue using biochemical radioreceptor assay. Of 125 tumours, 62% and 61% were positive for cER and cPR, respectively, 50% contained nER with high affinity for oestradiol (nER I) and 13% expressed nER with low affinity for oestradiol (nER II). The concentration of cER correlated significantly with age, cPR and log nER I. A significant proportion of tumours which were positive for both cytosol receptors also possessed nuclear receptors with high and low affinity for oestrogen. It is possible that this group of tumours which are positive for cER, cPR, nER I and nER II will respond well to hormone therapy.

Breast Neoplasms↗
PubMed1984

Reducing self-injury and corresponding self-restraint through the strategic use of protective clothing.

We examined the use of protective clothing to reduce a retarded male's face-punching and leg-kicking and two corresponding forms of self-restraint--arm and leg self-restraint. The resident was observed each day in three sessions of randomly ordered conditions (one condition per session): without any protective clothing, with a padded helmet, and with a padded helmet and padded slippers. Use of the padded helmet substantially reduced face-punching and arm self-restraint. The addition of padded slippers reduced leg-kicking and leg self-restraint. These results suggest a practical and effective means of controlling self-injury and self-restraint. They are also consistent with the possibility that the resident's arm restraint was maintained in part by escape or avoidance of face-punching and that his leg restraint was maintained in part by escape or avoidance of leg-kicking.

Adolescent↗
PubMed1983

Factors affecting solubilized dopamine-sensitive adenylate cyclase.

Bovine striatal adenylate cyclase was solubilized with sodium cholate and assayed for its responsiveness to a variety of agents. Magnesium ions (0-20 mM), guanylyl-imidodiphosphate (10-50 microM), and striatal lipids were effective in increasing enzyme activity. The adenylate cyclase could be stimulated by dopamine, and neuroleptic drugs inhibited the effect of dopamine (50 microM) with potencies that paralleled their clinical potencies. The IC50 values for spiroperidol, haloperidol and chlorpromazine were 0.2, 3 and 500 nM respectively.

Adenylyl Cyclase Inhibitors↗
PubMed1983

The unit play manager as facilitator of purposeful activities among institutionalized profoundly and severely retarded boys.

Child care workers were trained in specified techniques (play manager routines) in an effort to increase purposeful activity among a group of profoundly and severely retarded institutionalized boys. A system of prompts, increasing the availability of toys and regular staff monitoring, were alternated with normal institutional routines in an ABA reversal design. On the average, activity level increased from 10% to a mean of 70% during treatment conditions. Correspondingly, stereotyped or harmful behaviors decreased from an average of 20% to 70% during treatment.

Adolescent↗
PubMed1982

Concerning the decarboxylation of 3-carboxysalsolinol.

3-Carboxysalsolinol (14C-COOH) was prepared from DOPA (1-14C). Both in vitro and in vivo studies were conducted to examine the possibility that this amino-acid tetrahydroisoquinoline is converted to salsolinol in a parallel manner to the formation of dopamine from its amino-acid precursor. The results showed that this is not so for DOPA is decarboxylated far more readily than is 3-carboxysalsolinol. Small quantities of carbon dioxide (14C) are liberated from 3-carboxysalsolinol (14C-COOH), but this may reflect non-enzymatic decarboxylation.

Animals↗
PubMed1980

Supersensitivity in rat caudate nucleus: effects of 6-hydroxydopamine on the time course of dopamine receptor and cyclic AMP changes.

The intranigral administration of 6-hydroxydopamine resulted in the destruction of dopaminergic nerve terminals in the rat caudate nucleus and a 98% decrease in dopamine content. The time courses of the effects of this treatment on dopamine stimulated cyclic 3',5'-AMP accumulation in slices of caudate nucleus and on dopamine receptors in two behaviorally distinct denervation syndromes were determined in an investigation of the mechanisms underlying supersensitivity in this system. The density of dopamine receptors was determined by measuring the high affinity binding of the dopamine receptor antagonist [3H]haloperidol. The density of dopamine receptors was decreased 4 days after the lesion surgery and this effect was probably due to the loss of presynaptic receptors. The density of dopamine receptors and the acumulation of cyclic AMP then increased, with a slower time course, reaching peak levels 10 days after lesioning. The maximal increase in density of dopamine receptors was 70% in both denervation syndromes, while the maximal increase in dopamine-stimulating cyclic 3',5'-AMP levels was 300% at maximally stimulating concentration. The equilibrium dissociation constant (Kd) for haloperidol remained unchanged for 3 weeks following denervation, but there was a slight increase in Kd 40 days post-surgery. The turning behaviour in both syndromes was correlated with a decrease in doapmine levels. The present results are consistent with the notion that the supersensitivity to dopamine that occurs in caudate nucleus following 6-hydroxydopamine lesions has both pre- and post-synaptic components in both syndromes.

Animals↗
PubMed1979

Action on alcohol.

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Alcohol Drinking↗
PubMed1979

Time delay: a technique to increase language use and facilitate generalization in retarded children.

Institutional breakfast-serving procedures were manipulated to assess what effect changes in that aspect of the environment would have on requests for food. During baseline, six severely retarded children were required to pick up their food trays and return to their seats. The first manipulation, delaying the giving of the food tray for 15 seconds, served as a cue to evoke meal requests by three of the six children. Two of the remaining three required a model of an appropriate meal request (i.e., "Tray, please.") at the end of the 15-second delay before they began requesting their meals. To evoke meal requests from the sixth child, an intensive training procedure, consisting of massed trials of delay and modeling, was required. Three different probes were administered to assess generalization across the people serving the meals, across mealtimes, and across both people and mealtimes. Typically, generalized responding in these new situations could be prompted by use of the 15-second delay procedure. Functional aspects of the delay procedure and its potential usefulness for evoking speech and facilitating generalization are discussed.

Adolescent↗