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Biomedical subjects

R C Marshall

Publications and source records attributed to R C Marshall.

At least 73 records · Page 4Linked to original sources
PubMed1978

An animal model for evaluating the local and systemic effects of topically applied corticosteroids on epidermal DNA synthesis.

A simple animal model for studying topically applied glucocorticosteroids for their effect on epidermal DNA synthesis is described. It is designed so that their potential for systemic side effects may be predicted and its usefulness in this respect is illustrated by the results obtained with two of the steroids investigated. One, a new formulation Temetex, is predicted to have considerable systemic potential. The other, Molivate, is remarkable for having moderate local, without demonstrable systemic activity.

Administration, Topical↗
PubMed1978

The effects on epidermal DNA synthesis of the butyrate esters of clobetasone and clobetasol, and the propionate ester of clobetasol.

An animal model for evaluating the effects of drugs on epidermal DNA synthesis has been used to determine the time of onset, period of maximum activity and duration of effect of two topically applied proprietary glucocorticosteroids, clobetasone butyrate and clobetasol propionate. Both drugs produced maximum inhibition of epidermal DNA synthesis by 24 h after application. Clobetasol propionate exhibited a significantly earlier onset (4 1/2 h) and longer duration (36 h) of activity than clobetasone butyrate (6 and 24 h respectively). A systemic effect was not observed at any time after the application of clobetasone butyrate but was observed for up to 24 h after the application of clobetasol propionate. Clobetasol butyrate was also assayed in this system and was found to be as potent as clobetasol propionate. It is concluded that the alcoholic, as opposed to the ketonic, grouping in the 11 positions of the steroid ring profoundly alters the potentials of this molecule for systemic activity.

Animals↗
PubMed1978

Assessment of cardiac performance with quantitative radionuclide angiocardiography. Effects of oral propranolol on global and regional left ventricular function in coronary artery disease.

The effect of incremental dosages of oral propranolol (mean peak dose of 165 +/- 13 mg/day) of left ventricular ejection fraction, ejection rate and regional wall motion was studied sequentially in 22 stable, resting patients with coronary artery disease using a geometry-independent first-pass radionuclide angiocardiographic technique. All patients improved clinically, in association with a fall in heart rate and therapeutic serum propranolol levels. No significant changes were noted in ejection fraction, ejection rate or regional wall motion. No patient developed a new regional wall motion disturbance. Thus, oral propranolol administered at clinically effective antianginal dosages in patients with stable coronary artery disease does not appear to have significant deleterious effects on resting left ventricular performance.

Administration, Oral↗
PubMed1978

Letter recognition ability of aphasic subjects.

This study examined the letter-recognition abilities of 44 aphasic and 10 normal subjects. On a 26-item letter recognition task normal subjects made no errors. Moderately aphasic subjects illustrated minimal difficulty but did not differ significantly in performance from normals. Severely aphasic subjects exhibited marked impairment and made significantly lower letter-recognition scores than moderate aphasic or normal subjects. Type of aphasia as determined by conversational speech fluency (fluent or nonfluent) seemed to affect the letter-recognition performance of the severely aphasic subjects. Fluent severely aphasic subjects made significantly lower scores than all groups; nonfluent severely aphasic subjects made significantly lower scores than all groups except the severe nonfluent group. The types of letter-recognition errors produced by the two severely aphasic groups offer some explanation as to their performance differences. Errors of the latter group were more likely to be related to the stimulus letter; errors from the former group tended to be random. Findings indicate the intactness of the aphasic subjects's semantic associational network is important to the letter-recognition process.

Adult↗
PubMed1977

Proteins of the hard keratins of echidna, hedgehog, rabbit, ox and man.

In the accompanying paper it has been shown that two major groups of proteins (low-sulphur and high-sulphur) of ovine wool, horn, and hoof contain similar components although the overall proportions of the groups of proteins and the relative proportions of components within the groups may show significant differences. In the present paper it has been shown for five other species (echidna, hedgehog, rabbit, ox and man) that the hard keratins produced by one animal contain the same groups of protein components but in different relative proportions. The wide apparent differences in the type and relative proportions of the the low-sulphur components which comprise the major constituent proteins of the microfibrils suggest that microfibrils can tolerate a considerable variation in the constituent proteins and still produce functional structures. The low-sulphur protein components are sufficiently well resolved by sodium dodecyl sulphate-polyacrylamide gel electrophoresis to make this procedure potentially useful for animal identification and classification.

Amino Acids, Sulfur↗
PubMed1977

Imposed delay of response: effects on aphasics auditory comprehension of visuality and non-visually cued material.

Two groups of aphasics were administered an auditory comprehension task under conditions of 0-, 5-, and 10-sec. imposed delay of response. The auditory-visual group received auditory and visual cues; the auditory group received only auditory cues. Comprehension for the auditory-visual group was significantly better than for the auditory group. Increase in delay time significantly improved comprehension for the auditory-visual group but not for the auditory group.

Adult↗
PubMed1976

Word retrieval of aphasic adults.

This study determined (1) the types of word retrieval behaviors employed by aphasic adults in conversation and (2) the degree to which identified behaviors were successful in prompting production of intended words. Five retrieval behaviors--delay, semantic association, phonetic association, description, and generalization--were identified. It was possible to organize the retrieval behaviors of 18 aphasic subjects in a hierarchical order of efficiency. Use of a particular behavior and the success with which it facilitated production of an intended word appeared strongly related to severity of aphasia. Findings again bring to focus the significance of the associational processes to the problem of word retrieval in aphasia.

Adult↗
PubMed1976

Relaxation training: effects on the communicative ability of aphasic adults.

A verbal test battery (VTB) of four 15-item tests was administered to 16 aphasic adults following a period of relaxation training and a control period. Results indicate that verbal communication of aphasic persons is positively influenced by relaxation training. Subjects had significantly higher overall VTB scores and naming test scores following relaxation. Findings are discussed in terms of the use of relaxation procedures as an adjunct to conventional language therapy approaches for the aphasic adult.

Adult↗
PubMed1976

High-sulphur proteins from alpha-keratins. I. Heterogeneity of the proteins from mouse hair.

The heterogeneity of the reduced and S-carboxymethylated high-sulphur protein fraction from mouse hair has been examined by chromatography and polyacrylamide gel electrophoresis at pH values above and below the isoelectric region. Considerable heterogeneity is observed both in size (molecular weight range 12000-45000) and in charge. Amino acid analysis of a number of column chromatographic fractions shows the high-sulphur proteins to be largely composed of proteins with a carboxymethylcysteine content above 25 residues and a pronounced heterogeneity in arginine content. Their chromatographic behaviour is similar to that observed for the ultra-high-sulphur proteins from wool.

Amino Acids↗
PubMed1976

High-sulphur proteins from alpha-keratins. II. Isolation and partial characterization of purified components from mouse hair.

The present paper continues the study of the reduced and S-carboxymethylated high-sulphur proteins from mouse hair. Fractions have been obtained in a substantially purified form by fractional precipitation with ammonium sulphate at pH 6, followed by ion exchange chromatography on cellulose phosphate at pH 2.6. Approximately 80% by weight of the high-sulphur proteins fall into the ultra-high-sulphur category (carboxymethylcysteine content greater than 26 residues per 100 residues), and they cover a molecular weight range of 17000-28000. The components show a remarkable diversity in amino acid composition; for example the contents of arginine and glycine each vary by about 3:1. The remainder of the proteins contain 17-20 residues per 100 residues of carboxymethylcysteine, are smaller in size (molecular weight 11500), and also show great diversity in overall amino acid composition. Molecular weights were determined by chromatography on controlled-pore glass and confirmed by gel filtration on Sephadex G-100 and Sepharose 6B. A comparison of the results suggests that the values obtained should be reliable to within 10%.

Amino Acids↗