Biomedical subjects

L Franklin

Publications and source records attributed to L Franklin.

14 recordsLinked to original sources

PubMed1992

Morbidity among bathers exposed to polluted seawater. A prospective epidemiological study.

As the first phase of a major programme to develop epidemiologically derived recreational water quality criteria for South Africa, a preliminary epidemiological-microbiological study was conducted in Cape Town during February and March 1990. Serial trials were carried out at a clean and at a relatively polluted beach over weekends. Participants were recruited at the beach, at which time information on swimming status and sociodemography was obtained. This provided for a beach-going but non-swimming control group. Symptoms which developed subsequent to the beach visit were obtained by follow-up telephone interviews conducted 3-4 days later. Water samples collected on trial days both before and during maximum swimming activity, were analysed for enterococci, faecal coliforms, staphylococci, coliphages and F-male-specific bacteriophages. Significant differences in the indicator levels at the beaches were observed. An excess in gastro-intestinal, respiratory and skin symptoms were found among swimmers relative to non-swimmers at the polluted beach. Although not statistically significant, the results are suggestive of a relationship between swimming-associated illness and water quality. The study demonstrated the feasibility of the methodology and the results of the overall programme will form the basis for the development of epidemiologically derived recreational water quality criteria for South African beaches.

Bathing Beaches↗

PubMed1992

Changes in body composition of patients with subnormal spontaneous secretion of growth hormone, during the first year of treatment with growth hormone.

The effects of 1 year of growth hormone (GH) therapy were studied in 10 subjects with subnormal spontaneous secretion of GH, whose ages ranged from 6.5 to 12.4 years. Height, weight, body fat percentage, total body potassium (TBK), and extracellular water (ECW) were measured prior to initiating the treatment, and thereafter at 6 months (period 1) and 12 months (period 2). Height velocity almost doubled during the year of treatment: 7.8 +/- 0.8 and 7.1 +/- 0.7 cm/yr (P less than .0001) during periods 1 and 2, respectively, as compared with 3.9 +/- 0.6 cm/yr pretreatment. Body fat percentage decreased during period 1 to 18.2% +/- 4.9%, versus 16.3% +/- 4.5% (P less than .02), but stabilized thereafter (16.3% +/- 4.9%). Mid-arm muscle circumference (MAMC) and TBK increased in accordance with the predicted values for age. Body mineral density (BMD) increased both in absolute and standardized terms. No changes were found in ECW during treatment. We concluded that GH treatment in children with subnormal spontaneous secretion of GH has mainly a lipolytic effect on body composition, and that resistance to the lipolytic effect develops during the course of therapy.

Anthropometry↗

PubMed1992

Maudsley reactive (MR/Har) and nonreactive (MNRA/Har) rats: performance in an operant conflict paradigm.

The present studies were designed to characterize the behavior of Maudsley reactive (MR/Har) and nonreactive (MNRA/Har) rats in a modification of the Geller-Seifter operant conflict paradigm. Food-restricted (85% of free-feeding weights) female MR/Har and MNRA/Har rats were trained to lever press for food reinforcement in a multiple-schedule operant conflict paradigm. In the absence of a tone, a fixed ratio-30 (FR-30) schedule for reinforcement only was in effect (i.e., every 30th lever press resulted in the delivery of a 45-mg food pellet). During the presence of a tone, a fixed ratio-1 (FR-1) schedule of both reinforcement (food) and punishment (0.20 mA footshock applied for 500 ms) was in effect (i.e., each lever press resulted in both food and shock delivery). The tone periods were 27 s in duration and were presented on a variable interval (VI)-120-s schedule (approximately 20 tones/40-min session). Behavioral testing was conducted 5 days/week for 35 weeks. Initially, punished responding between the MR/Har and MNRA/Har rat strains did not differ dramatically. However, over the course of many weeks of conflict testing, rats of the MNRA/Har strain came to accept significantly more shocks than did subjects of the MR/Har strain. A direct examination of footshock sensitivity in these rats revealed that this difference in conflict behavior over time was not due to strain differences in shock sensitivity. The mechanism for this time-dependent difference in conflict behavior between the MR/Har and MNRA/Har rats remains undetermined.

Animals↗

PubMed1988

Depletion of central catecholamines reduces pressor responses to arginine vasopressin.

Previous reports that central administration of arginine vasopressin (AVP) increases turnover of brain catecholamines raise the possibility that the pressor responses which follow central administration of AVP may be mediated, in part, by central catecholamines. To test this hypothesis, rats were given intraventricular injections of vehicle, or of the neurotoxin, 6-hydroxydopamine, which resulted in significant depletions of hypothalamic and medulla oblongata noradrenalin and hypothalamic dopamine, but not of medullary dopamine or of hypothalamic and medullary 5-hydroxytryptamine. Following a one week recovery, these conscious rats, fitted with indwelling arterial catheters, were given intraventricular injections of AVP; the increases in arterial pressure and heart rate were significantly reduced in the catecholamine-depleted animals. These data support the hypothesis that the pressor and tachycardia responses to intraventricular AVP are mediated, in part, by central catecholamine-containing neurons.

Animals↗

PubMed1986

Comparison of three cholesterol-lowering diets in normolipidemic men.

Saturated fatty acids and cholesterol in the diet raise the plasma cholesterol concentration, and a reduction in these constituents is recommended widely. However, there is not general agreement as to which nutrients should replace saturated fatty acids. Several different substitute nutrients are possible. In this study, three cholesterol-lowering diets were compared in nine men living in a domiciliary. On a typical American diet at baseline, cholesterol levels were in the normal range. One replacement diet was high in polyunsaturated fatty acids (High Poly); another had 30% fat and corresponded to the American Heart Association's (AHA) recommended diet for the general public (AHA phase I); the third diet had 20% fat, equivalent to the AHA phase III diet for treatment of hypercholesterolemia. Compared with baseline levels, all diets caused similar reductions in total cholesterol and low-density lipoprotein cholesterol levels, but the High Poly and AHA phase III diets lowered the high-density lipoprotein cholesterol level more than the AHA phase I diet. Thus, for the limited number of patients in this study, the diet recommended for the general public appeared as effective for lowering of cholesterol levels as diets containing more polyunsaturates or more carbohydrates.

Aged↗

PubMed1973