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Biomedical subjects

R W Jones

Publications and source records attributed to R W Jones.

At least 163 records · Page 9Linked to original sources
PubMed1980

Oral essential amino acid supplements in children with advanced chronic renal failure.

The effects on growth, nitrogen balance, and body composition of a protein-restricted diet supplemented with oral essential amino acids (EAA) were studied in seven children with advanced chronic renal failure. The diet was designed to provide minimum protein requirements for height-age, half in unselected form and half as an EAA supplement. Energy from carbohydrate and fat were increased to give a protein/energy ratio of 1.25 G:100 kcal. Nitrogen balance, studied in five children before and after 6 to 8 months of EAA treatment, was improved in each case. intracellular water (total body water minus bromide space) increased in four children but fell in three children during treatment. No significant improvement in growth, expressed as height or height velocity standard deviation scores in relation to bone age, was observed. Serum urea and urea/creatinine ratio fell after institution of EAA treatment, but the fall was not sustained. Although the EAA preparation proved acceptable to the children, dietary assessments indicated that the desired dietary aims were rarely achieved. It is concluded that, in this pediatric age group, the long-term application of a protein restricted diet with EAA supplements is of limited value.

Adolescent↗
PubMed1980

Q fever endocarditis in a 6-year-old child.

A 6-year-old boy with a congenital bicuspid aortic valve presented with finger clubbing and hypertrophic osteoarthopathy, and subsequently he developed severe hypertension. The hypertension was successfully treated by nephrectomy, at which a thrombosed mycotic aneurysm of the renal artey was found. Echocardiography showed the presence of aortic valve vegetations. Blood cultures were sterile, but high antibody titres to the phase 1 and 2 antigens of Coxiella burneti strongly suggested Q fever infection. We believe this is the first reported case of Q fever endocarditis in early childhood.

Child↗
PubMed1980

Hypertension in a four-year-old child: gas chromatographic and mass spectrometric evidence for deficient hepatic metabolism of steroids.

A 4-yr-old boy with hypertension and hypokalaemic alkalosis had low plasma aldosterone levels and renin activity. The hypertension and hypokalemia responded to spironolactone and triamterene therapy. A partial response to dexamethasone was observed. Analysis of urinary steroid metabolites by gas chromatography-mass spectrometry showed that the excretion of metabolites of deoxycorticosterone and aldosterone was subnormal, and there was no evidence for sizeable excretion of unusual steroids with potential mineralocorticoid activity. The cortisol excretion rate, however, was subnormal, and the relative excretions of individual metabolites of this hormone were not typical. In particular, the excretion of tetrahydrocortisone was markedly reduced, and the excretions of allotetrahydrocortisol and free cortisol and metabolites were elevated. These findings suggest that modified or deficient metabolism of adrenal steroids could give rise to elevated blood pressure. It is not known whether the inappropriate production of unusual cortisol metabolites were responsbile for the high blood pressure or whether the altered metabolism is indicative of similar abnormality in the metabolism of other adrenal steroids, resulting in hyperproduction or extended half-life of minor but highly active mineralocorticoids of unknown structures.

Aldosterone↗
PubMed1980

The alcoholic social worker: a survey.

This paper presents data on 50 alcoholic social workers who had successfully stopped drinking for one year or more. In spite of the fact that these social workers were in many cases visibly in trouble with 63 arrests, 120 inpatient admissions, 13 suicide attempts, and a high reported incidence of addiction to other drugs, they found that collaegues and superiors as well as professionals from whom they sought individual treatment were extremely reluctant to confront the alcoholism problem directly. The authors urge social workers to consider ways of offering help to colleagues in a more systematic manner than is currently available.

Adult↗
PubMed1980

The pharmacokinetics and acceptability of benoxaprofen following rectal administration.

The bioavailability of a single 300 mg dose of benoxaprofen was compared after rectal and oral administration in 5 subjects. The total absorption rectally from a suppository was 83% of that achieved orally from a capsule. Six further subjects took a 300 mg benoxaprofen suppository twice daily for 12 d. Steady state plasma levels (mean level 94 microgram/ml) were reached at about 120 h, while the elimination half-life for benoxaprofen was approximately 38 h in this study. The suppositories were well tolerated. The plasma levels obtained compared very favorably with theoretically expected levels and levels obtained after comparable oral doses.

Absorption↗
PubMed1979

Prostaglandin and thromboxane production by human and guinea-pig macrophages and leucocytes.

The ability of partially purified human and guinea-pig haematogenous cell populations, when cultured in vitro, to metabolise arachidonic acid (AA) has been studied. Supernatants from 24 hour cell culture have been subjected to analysis for products of AA metabolism by gas chromatography with electron-capture detection. The cell types studied were human peripheral blood monocytes (both glass adherent and non-adherent), neutrophils, eosinophils and leukemia leucocytes; thoracic duct lymphocytes and lung alveolar macrophages. From the guinea-pig, induced and non-induced macrophage or neutrophil enriched peritoneal exudate populations, lymph node cells, peritoneal eosinophils and peripheral blood platelets were examined. Supernatants were assayed for the presence of PGE2, PGD2, PGF2 alpha, TXB2 and 6-keto-PGF1 alpha. In all types studied PGE2 and TXB2 were the major products formed. The identification of PGE2 and TXB2 was confirmed by GC/MS with multiple ion monitoring. The results have been compared with other reports and their possible significance discussed in relation to the proposed role of prostaglandins as mediators and modulators in immunopathology.

Animals↗
PubMed1979

1028 neonatal electrocardiograms.

Electrocardiograms were recorded from 1028 (99.4%) of 1034 consecutively born babies on the 1st or 2nd day of life. Abnormalities of cardiac rhythm or conduction were found in 49 (4.8%) babies. 17 babies had single or multiple premature beats during the recordings, and 7 babies showed sudden increases in R-R interval possibly due to sinoatrial node dysfunction. One baby had sinus or junctional bradycardia of less than 80 beats/min. One baby had an incessant reciprocating tachycardia and subsequently required digoxin for heart failure. Continuous 24-hour ECG monitoring in 25 babies with abnormalities of the screening ECG, and 25 babies without such abnormalities, failed to show any additional tachyarrhythmias or bradyarrhythmias warranting treatment. In view of the uncertain clinical significance of many neonatal arrhythmias and cardiac conduction disorders, more information concerning their natural history and relationship to sudden unexpected death in infancy is needed before recommending that neonatal ECG screening be generally adopted.

Arrhythmias, Cardiac↗
PubMed1978

Preparation of chromatin containing ribosomal deoxyribonucleic acid from the macronucleus of Tetrahymena pyriformis.

A method is described that enables a chromatin fraction containing ribosomal DNA (DNA containing sequences coding for rRNA) to be prepared from the macronuclei of growing or stationary cultures of Tetrahymena pyriformis. This material is obtained in yields of between 25 and 75% of the theoretical maximum. The DNA in this fraction was identified as ribosomal DNA on the basis of its density and molecular weight, and it appears not to be appreciably contaminated by other DNA. The method relies on the approximate assumption that ribosomal DNA is the smallest species of DNA in chromatin in the nucleus, and avoids the use of mechanical force, or enzyme action, to fractionate chromatin.

Animals↗
PubMed1978

Histone composition of a chromatin fraction containing ribosomal deoxyribonucleic acid isolated from the macronucleus of Tetrahymena pyriformis.

The histone compositions of a chromatin fraction containing ribosomal DNA and of the remaining macronuclear chromatin of Tetrahymena pyriformis was analysed by gel electrophoresis. These chromatin fractions were used as models for transcriptionally active and inactive chromatin respectively. The extent of histone modification, as indicated by the distribution of histone between differently charged subspecies in acid-urea gels, is not grossly different in the two chromatin fractions. However, histone H1 is present, but may be differently modified in the two chromatin fractions. The histone/DNA ratio in ribosomal chromatin, measured after sodium dodecyl sulphate/polyacrylamide-gel electrophoresis of samples of chromatin, was found to be the same whether chromatin was extracted from growing or stationary organisms, and to be approx. 40% of this ratio in the remaining macronuclear chromatin. The implications of these results for the possible structure of transcriptionally active chromatin are discussed.

Animals↗
PubMed1978

Satisfaction in male homosexual couples.

Little information exists regarding factors in the satisfaction and stability of male homosexual relationships. On the basis of interviews with 14 male couples an open-ended questionnaire was developed concerning gay couples' relationships. This questionnaire and a modified version of the Marital Relationship Inventory, called here the Couples Relationship Inventory (CRI), were administered to 28 couples who described themselves as in a primary, relatively long-term relationship. Couples' descriptions of the successfulness of their relationships in conventional, heterosexual-oriented terms on the CRI were similar to their descriptions on the more homosexual-oriented, open-ended questionnaire. The study is seen as providing a point of departure for future research on gay relationships and the behavior transactions that may differentiate satisfying from unsatisfying relationships.

Adaptation, Psychological↗
PubMed1977

Sites and specificity of the reaction of bipyridylium compounds with anaerobic respiratory enzymes of Escherichia coli. Effects of permeability barriers imposed by the cytoplasmic membrane.

The ability of the oxidized and singly reduced species of several bipyridylium cations to cross the cytoplasmic membrane of Escherichia coli was studied to locate the sites of reaction of the dyes with anaerobic respiratory enzymes. Benzyl Viologen radical crossed the membrane rapidly, whereas the oxidized species did not. The oxidized or radical species of Methyl Viologen, Morfamquat or Diquat did not rapidly cross the membrane. It was also shown that the dithionite anion does not cross the cytoplasmic membrane of E. coli. Diquat radical donates electrons to the nitrate reductase pathway at the periplasmic aspect of the membrane, whereas Benzyl Viologen radical reacted directly with nitrate reductase itself (EC 1.7.99.4) at the cytoplasmic aspect of the membrane. Thus the pathway of electron transfer in the nitrate reductase pathway is transmembranous. Formate hydrogenlyase (EC 1.2.1.2) and an uncharacterized nitrite reductase activity react with bipyridylium dyes at the periplasmic aspect of the membrane. Fumarate reductase (succinate dehydrogenase; EC 1.3.99.1) reacts with bipyridylium radicals, and formate dehydrogenase (cytochrome) (EC 1.2.2.1) with ferricyanide, at the cytoplasmic aspect of the membrane. The differing charge and membrane permeation of oxidized and radical species of bipyridylium dyes greatly complicate their use as potentiometric mediators in suspensions of cells or membrane vesicles.

Aldehyde Oxidoreductases↗