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Biomedical subjects

R Stewart

Publications and source records attributed to R Stewart.

At least 19 recordsLinked to original sources
PubMed1992

The effects of melanocortins and electrical fields on neuronal growth.

The effects of the neuropeptide molecules, adrenocorticotrophic hormone or alpha-melanocyte stimulating hormone, on various parameters of in vitro nerve growth, have been studied in the presence and absence of a small applied electric field. Striking effects on rates of nerve growth occurred. Selected concentrations of either substance alone, produced a three- to fourfold increase in nerve growth rate; other concentrations were inhibitory. The applied electric field alone increased rates of growth threefold. Further augmented rates of growth were seen when either neuropeptide was present simultaneously with an applied field. Under these latter conditions, galvanotropic (cathodal) orientation persisted, while nerve branching was suppressed. Given the clinical interest in melanocortin-stimulated nerve regeneration, perhaps a combined electrical and neuropeptide approach would be warranted.

Adrenocorticotropic Hormone↗
PubMed1992

Xamoterol in hypertrophic cardiomyopathy: effects on diastolic function and heart rate.

The aims of this study were to determine the effects of the partial beta 1-adrenergic agonist, xamoterol, on diastolic function and ambulatory heart rate in hypertrophic cardiomyopathy. Eleven patients with non-obstructive hypertrophic cardiomyopathy were studied with cross-sectional and Doppler echocardiography and 24-h Holter monitoring before and after a single intravenous dose of xamoterol. Resting heart rate (mean +/- SD) increased from 76 +/- 16 before, to 83 +/- 15 beats/min 15 min after xamoterol, p = 0.03. In the 4-h period after xamoterol, maximum heart rate was reduced (127 +/- 21 to 112 +/- 19, p = 0.01) and minimum heart increased (60 +/- 16 to 67 +/- 17, p = 0.04) compared to the same 4-h period of the previous day. There were no significant changes in cross-sectional or Doppler echocardiographic measurements of left ventricular function following xamoterol. Xamoterol stabilises the heart rate in hypertrophic cardiomyopathy. The absence of a significant effect on Doppler measurements does not preclude a beneficial effect on diastolic function. This initial study suggests that xamoterol should be further investigated as a new medical therapy for hypertrophic cardiomyopathy.

Adolescent↗
PubMed1979

The nature of needs assessment in community mental health.

Confusion in defining needs assessment is discussed. A tripartite model of needs assessment is proposed: an identification of a problem; a statement about priorities; and a chosen solution. The parts can be used independently or linked together to plan new or altered services. Various needs assessment techniques are examined for their usefulness in each area. Two examples of needs assessment processes are given.

Community Mental Health Services↗
PubMed1979

Updated in vivo methods for evaluating topical antimicrobial agents on human skin.

Updated and expanded in vivo quantitative testing procedures to determine the efficacy of topical antimicrobial agents are presented. The occlusion test measures the ability of an agent to prevent the expansion of the resident microflora which occurs when an impermeable dressing is applied to the forearm. Measurements are made at 24 and 48 hr. The expanded flora test measures the ability of an agent to suppress a dense population of micro-organisms produced by expansion of the resident flora of the forearm by prior application of an impermeable occlusive dressing. Measurements are made at 6, 24 and 48 hr or after 10 min in the case for agents designed for immediate degerming. The persistence test measures the ability of an agent to establish a reservoir in skin and exert an antimicrobial effect up to 3 days after the last application of the test material. The ecological shift test determines any major alteration in cutaneous microbial ecology following several applications of the material under occlusive dressings. The serum inactivation test determines whether the presence of serum proteins interferes with antimicrobial activity.

Adult↗
PubMed1979

Neighborhood health center patients who use minor tranquilizers.

Thirty-four ambulatory medical patients who had used minor tranquilizers for varying lengths of time were interviewed to determine their medical and psychiatric statuses, and to learn their own perspective of their medical care. The population was elderly of lower socioeconomic status, and chronically ill (a significant minority with serious and disabling illness). Depressive equivalents, depression, and anxiety were prominent, but clinical states requiring psychiatric care were not. Slightly less than one-half were alcoholic. Forty-one percent took the medications for target symptoms other than anxiety, and 76% believed these agents were efficacious. Chronic users had significantly more chronic medical illness, and significantly more somatization, anxiety, and fatigue.

Acute Disease↗
PubMed1978

The G and BBB syndromes: case presentations, genetics, and nosology.

Hypertelorism and hypospadias are described in four unrelated boys; bilateral cleft lip and cleft palate were also present in two of the boys and mild mental retardation in another. These features are compatible with both the G and BBB syndromes. When present, laryngotracheoesophageal anomalies or respiratory and swallowing difficulties are characteristic features of the G syndrome; otherwise facial features may be useful in distinguishing the G and BBB syndromes. Cases 1 and 2 had anteverted nares and a broad and flat nasal bridge, and Case 1 had shortened palpebral fissures, all consistent with the G syndrome. In contrast, Cases 3 and 4 had a high and broad nasal bridge as previously described in the BBB syndrome. The father of Case 1 had mild hypertelorism and first-degree hypospadias, demonstrating autosomal dominant inheritance in the G syndrome. The mothers of Cases 2, 3, and 4 all had mild hypertelorism consistent with autosomal dominant inheritance and partial male-sex limitation, as previously proposed for both the G and BBB syndromes.

Abnormalities, Multiple↗
PubMed1978

Anterolateral rotatory instability of the knee joint. An early analysis of the Ellison procedure.

Our experience with the Ellison procedure for the control of anterior subluxation of the lateral tibial plateau includes fifty-two knees in which we used this procedure either alone or in combination with other reconstructive procedures. The results directly attributable to the Ellison procedure itself after follow-ups of six months or more could be evaluated in fifteen patients who had only the Ellison procedure for anterolateral instability and in thirteen who had both this procedure and a pes anserinus transfer for combined anterolateral and anteromedial instability. Of the twenty-eight patients so evaluated, only sixteen (57 per cent) had good or excellent results. The pivot-shift phenomenon, present in all twenty-eight knees preoperatively, had been eliminated in only four at follow-up. A positive anterior drawer sign was present in all patients both before operation and at follow-up. The subjective and functional improvement did not correlate well with the clinical and roentgenographic findings. From this study it is our impression that the results of this operation are disappointing and that it should be used only as an adjunctive procedure in lateral reconstruction in young patients.

Adolescent↗
PubMed1977

New uses for benzoyl peroxide: a broad-spectrum antimicrobial agent.

Benzoyl peroxide is a useful agent in the treatment of acne, chronic ulcers, tinea pedis, and tinea versicolor, probably because of its antimicrobial power. 2.5% concentration is almost as active as 5%. Although potential irritancy and allergic reaction have not been a problem on the face, benzoyl peroxide should be used judiciously in chronically inflamed or ulcerated skin. Several potential uses are mentioned.

Benzoyl Peroxide↗
PubMed1977

Failure of tyramine to induce migraine.

In a double-blind study of 80 migraine patients, headache was precipitated by ingestion of 200 mg tyramine and not by placebo in eight individuals, but retesting of seven of these patients did not produce the same results. Placebo produced as severe headache as tyramine and in an even larger number of patients. It is concluded that dietary tyramine alone is rarely, if ever, the major precipitant of a migraine attack, although the possibility remains that it has such a role in the presence of particular physiologic states.

Adult↗
PubMed1977

Urinary ammonia and ammonia-producing microorganisms in infants with and without diaper dermatitis.

Free ammonia was determined in diaper squeezings from 26 infants with "ammoniacal dermatitis" and in 82 controls. No significant difference was found (402 ppm in diaper dermatitis compared to 465 in controls). The groups did not differ with regard to the incidence of organisms capable of splitting ammonia from urea. Experimental application of highly ammoniacal urine on intact infant and adult skin failed to provoke a dermatitis. Erythema could be induced only when ammoniacal urine was applied occlusively to scarified skin. These findings do not support the notion that ammonia is a primary factor in common diaper rash, but do not exclude a possible role for further irritation in an already existent condition.

Ammonia↗