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Biomedical subjects

R Bryant

Publications and source records attributed to R Bryant.

At least 55 records · Page 3Linked to original sources
PubMed1987

Kinetic assessment of manganese using magnetic resonance imaging in the dually perfused human placenta in vitro.

The transfer and distribution of paramagnetic manganese was investigated in the dually perfused human placenta in vitro (using 10, 20, 100 microM Mn with and without 54Mn) using magnetic resonance imaging (MRI) and conventional radiochemical techniques. The human placenta concentrated 54Mn rapidly during the first 15 min of perfusion and by 4 hr was four times greater than the concentrations of Mn in the maternal perfusate, while the concentration of Mn in the fetal perfusate was 25% of the maternal perfusate levels. Within placentae, 45% of the 54Mn was free in the 100,000g supernatant, with 45% in the 1,000g pellet. The magnetic field dependence of proton nuclear spin-lattice relaxation time (T1) in placental tissue supports this Mn binding. Mn primarily affected the MRI partial saturation rather than spin-echo images of the human placenta, which provided for the separation of perfusate contributions from those produced by Mn. The washout of the Mn from the placenta was slow compared with its uptake, as determined by MRI. Thus, Mn was concentrated by the human placenta, but transfer of Mn across the placenta was limited in either direction. These studies also illustrate the opportunity for studies of human placental function using magnetic resonance imaging as a noninvasive biomarker.

Female↗
PubMed1986

The metabolic effects of thiazide therapy in the elderly: a population study.

The metabolic consequences of thiazide diuretics are well known. The elderly to whom these agents are widely prescribed may be particularly susceptible. To quantify this metabolic risk, plasma and intracellular electrolytes and plasma glucose were measured in the elderly population of a Somerset village. Highly significant reductions in both plasma and cellular magnesium and potassium were found in the 47 thiazide-treated people. Forty-eight per cent of the thiazide-treated group were hypomagnesaemic and 28% were hypokalaemic. Thus, magnesium and potassium depletion are commonly associated with thiazide therapy in the elderly. These metabolic effects should be considered carefully prior to the use of these agents.

Aged↗
PubMed1986

Chronic osteomyelitis caused by Staphylococcus aureus: controlled clinical trial of nafcillin therapy and nafcillin-rifampin therapy.

A controlled trial of treatment of chronic osteomyelitis caused by Staphylococcus aureus compared nafcillin alone with nafcillin plus rifampin for a six-week period. Treatment was well tolerated, the only adverse effect being mild neutropenia in four of 18 patients; no toxicity was observed from rifampin. Eight of ten patients in the combined treatment group had a favorable clinical response (with follow-up of two to four years) as compared to four of eight in the nafcillin group (P = .2). Despite the failure to show a statistically significant advantage of rifampin plus nafcillin, we conclude that the combination, along with appropriate surgery, should be considered for patients with chronic staphylococcal osteomyelitis.

Administration, Oral↗
PubMed1985

Anorexia nervosa: aetiological theories and treatment methods.

There is a rapidly developing but confusing body of research on anorexia nervosa. For the non-specialist, trends in research are obscured by a diversity of definitions and variations in the proposed locus of pathology: the individual, the family or the socio-cultural environment. While anorexia is a disorder which particularly needs research from a wide range of perspectives, it is vital that the different trends are frequently reviewed and, in the treatment process, integrated. This review summarizes the most significant developments in research on anorexia, and serves as an overview for clinicians wishing to consult the literature selectivity and in more depth.

Anorexia Nervosa↗
PubMed1985

A survey of ovine dermatophilosis in Western Australia.

A random sample of 200 Merino sheep owners was interviewed by telephone during April 1983 and asked questions relating to the prevalence of ovine dermatophilosis in their flocks, methods used for prevention and treatment of dermatophilosis, management strategies employed and the location and annual rainfall of each farm. The response rate was 99.5%. During the previous 12 months 62.3% of farmers had observed dermatophilosis in their flocks. The prevalence within flocks was highest in hoggets (mean 2.2%, range 0 to 75%) followed by lambs (mean 0.8%, range 0 to 25%), ewes (mean 0.6%, range 0 to 20%) and wethers (0.2%, range 0 to 20%). The mean weight of wool identified as affected by dermatophilosis was 58 kg (range 0 to 882 kg). Preventive measures were used on 57% of farms and the most common methods were changes in dipping practice (23.6%) and culling of affected sheep (21%). An average of 13.7 sheep per farm were culled for dermatophilosis and of these, 82% were sold and the remainder (18%) were killed on the farm. Antibiotics, of which most were combinations of penicillin and streptomycin were used to treat dermatophilosis on 8.5% of farms and treatments other than antibiotics were used on 10% of farms. The prevalence of dermatophilosis and its relationship to various environmental and management factors varied with the age and sex of sheep. Discriminant analysis indicated that of the factors studied, average annual rainfall, month of lambing, average fibre diameter and the month ewes were shorn were related to the prevalence of dermatophilosis in lambs.(ABSTRACT TRUNCATED AT 250 WORDS)

Age Factors↗
PubMed1981

Some isometric embedding and rigidity results for Riemannian manifolds.

In this note, we announce some new results concerning rigidity and isometric embeddings of Riemannian manifolds. A special case of the main result states that a general M(n) [unk] R(n+r), r</=(n - 1)(n - 2)/2, is uniquely determined up to finitely many constants by its induced ds(2).

Journal Article↗
PubMed1980

Leukocyte adherence in atopic dermatitis: diminished responses to histamine and isoproterenol.

Leukocyte adherence was examined in atopic and normal subjects and the influence of histamine and the beta-adrenergic agonist, isoproterenol, evaluated. Atopics included patients with mild to severe atopic dermatitis and patients with asthma and hayfever. No inter-group differences in leukocyte adherence of untreated leukocytes could be demonstrated, but there was a significantly smaller histamine and isoproterenol effect on the adherence of cells from patients with atopic dermatitis and hayfever. The induced inhibition of leukocyte adherence by histamine could be blocked by the H-2 histamine receptor antagonist, metiamide, suggesting that this effect may be mediated via cAMP. Our findings support the hypothesis that atopic dermatitis patients may have a defect or blockade of their cellular response to histamine.

Dermatitis, Atopic↗