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Biomedical subjects

R W Jones

Publications and source records attributed to R W Jones.

At least 145 records · Page 8Linked to original sources
PubMed1982

Restriction endonuclease maps of the beta-like globin gene cluster in the British and Greek forms of HPFH, and for one example of G gamma beta + HPFH.

We report here restriction endonuclease maps of the beta-like globin gene cluster for the British form of HPFH and for a case of G gamma beta + HPFH, and also confirm and extend previous reports of the map for the Greek form of HPFH. These results show that all these conditions belong to a group lacking any substantial deletion or rearrangement of DNA sequence in this gene cluster. The absence of any gross disruption of the structure of this region of the genome, together with evidence that the HPFH genotype is either allelic with, or closely linked to, the beta-like globin gene cluster, suggests that the responsible lesions are nearer to being purely regulatory in nature than in forms of HPFH due to substantial deletions. Thus these conditions promise to provide less equivocal evidence about the regulation of beta-like globin gene expression than has so far been available.

Chromosome Mapping↗
PubMed1982

The femininity and masculinity of partners in heterosexual and homosexual relationships.

This research addressed three questions: (1) Did partners in homosexual relationships perceive themselves as less stereotypically feminine or masculine than partners in heterosexual relationships? (2) Did partners complement or match each other in their self-perceived femininity and masculinity? (3) What was the correlation of partners' femininity and masculinity to their views on attachment and autonomy in their relationships? The high level of androgyny (87%) in the sample precluded making the intended comparisons. There was, however, some evidence in the heterosexual partners to support the assumption of feminine-masculine complementarity and some to support the link between masculinity and devaluation of attachment. In the discussion, questions were raised about the atypicality of the San Francisco Bay Area sample, about the validity and reliability of the Personal Attributes Questionnaire as a measure of social sex-role, and the basic adequacy of questionnaires that assume that self-knowledge is easily elicited from respondents.

Adult↗
PubMed1982

Benoxaprofen and its effect on serum alkaline phosphatase: a review.

Benoxaprofen is a nonsteroidal anti-inflammatory agent with a novel spectrum of pharmacological activity including regulatory effects on monocytes. It significantly reduces the serum alkaline phosphatase in patients with osteoarthritis, rheumatoid arthritis, and ankylosing spondylitis. The reduction usually has been within the normal range, but sometimes there has been a change from an abnormal to a normal value. The possible significance of this observation and ways of examining it further are discussed in this review. The reduction may be an effect on osteoblasts secondary to an effect on osteoclasts, cells known to be derived from monocyte precursors. If so, benoxaprofen should be effective in Paget's disease of the bone and preliminary data suggest this may be so.

Alkaline Phosphatase↗
PubMed1981

Restriction mapping of a new deletion responsible for G gamma (delta beta)o thalassemia.

DNA from individuals heterozygous for (G)gamma(deltabeta)(o) thalassaemia has been studied by restriction endonuclease analysis. The results reveal a new molecular defect associated with this condition. A total of three defects is now responsible for the one single phenotype, thereby emphasising the complex relationship between genotype and phenotype among the disorders of beta-like globin synthesis in man.

Chromosome Deletion↗
PubMed1981

The congenital varicella syndrome.

Two children, aged 18 months and 3 years, with the congenital varicella syndrome are described. Neuropathic bladder and lax abdominal wall musculature were present in one case. In the other, paralysis and marked hypoplasia of one arm, and an ipsilateral Horner's syndrome, were the main abnormalities. Extensive skin scarring corresponding to a dermatome distribution was present in both children. This constellation of abnormalities, which may best be explained on the basis of a developmental radiculopathy, emphasises the neuropathic effects on the fetus of varicella zoster (VZ) infection in early pregnancy.

Abnormalities, Multiple↗
PubMed1981

Endarterial urokinase in childhood hemolytic uremic syndrome.

Urokinase was given by unilateral infusion for 48-168 hours into the renal arteries of 8 children (0.2 to 13.0 years) with acute renal failure and impaired renal perfusion due to hemolytic uremic syndrome (HUS). Two children subsequently received a bilateral infusion. Immediate changes in renal perfusion were assessed by serial dynamic renal scanning in all patients and by repeat renal arteriography in 5. No improvement clearly attributable to urokinase was observed. In 4 surviving children assessment of divided renal function by static renal scanning 1 to 5 years after presentation showed no evidence of benefit from urokinase. Examination of the kidneys of 2 of the 3 children who died, and one who underwent bilateral nephrectomy prior to renal transplantation, showed no evidence of benefit from urokinase. Examination of the kidneys of 2 of the 3 children who died, and one who underwent bilateral nephrectomy prior to renal transplantation, showed no preservation of renal mass attributable to urokinase; in one of these children the infused kidney was considerably smaller than the untreated kidney. It is concluded that local infusion of urokinase had no beneficial effect on the course of HUS in these children.

Adolescent↗
PubMed1981

Embryonic erythroid differentiation in the human leukemic cell line K562.

K562 human leukemia cells synthesize embryonic hemoglobins after culture in the presence of hemin. We have rigorously identified these hemoglobins by globin chain analysis and peptide mapping. No adult hemoglobin could be detected, and beta-globin synthesis was less than 2 ppm of total protein synthesis. Persistent embryonic globin gene expression is known to occur as a consequence of globin gene deletions. However, restriction endonuclease mapping showed that the globin gene complexes in K562 cells are indistinguishable from normal. Hemin increased the rate of embryonic globin synthesis. The pattern of hemoglobin synthesis proved to be stable when cells from different laboratories were compared. One line, however, synthesized large amounts of Hb X and very little Hb Portland in response to hemin. Hb X has been previously detected in human embryos; we show here that it has the composition epsilon 2 gamma 2 and is diagnostic of imbalanced chain synthesis or "zeta thalassemia." We have identified several agents that induce hemoglobin synthesis in K562 cells. Different inducers induced different patterns of embryonic hemoglobin synthesis but never any adult hemoglobin synthesis.

Cell Differentiation↗
PubMed1981

Rescue of noncultivatable human rotavirus by gene reassortment during mixed infection with ts mutants of a cultivatable bovine rotavirus.

Fastidious human rotaviruses that did not undergo productive infection in tissue culture were rescued by genetic reassortment during mixed infection with a temperature-sensitive (ts) mutant of a cultivatable bovine rotavirus. In this manner, the genes of the fastidious rotavirus that restricted growth in vitro were replaced by the corresponding genes from a tissue culture-adapted rotavirus. We recovered genetically reassorted viruses that grew to high titer and were neutralized specifically by hyperimmune guinea pig type 1 or type 2 human rotavirus antiserum. Preliminary RNA analysis of these clones disclosed that they were indeed viruses with reassorted genes.

Animals↗
PubMed1981

Nutritional management of chronic renal failure in childhood.

Protein malnutrition is common in children with chronic renal failure (CRF) and is especially severe in young infants. Growth is usually rapid in infants and CRF causes a reduction in cell mass associated with extreme growth retardation in this age group. Poor energy intake and altered energy metabolism are common in CRF and are associated with protein malnutrition and poor growth. Uraemic toxicity may reduce protein synthesis by altering energy metabolism or by a direct effect, low protein high energy diets improve growth and extremely low nitrogen intakes supplemented with essential amino acids and keto acids may be useful in selected children.

Amino Acids↗
PubMed1981

Body composition in children on regular hemodialysis.

Body composition was estimated in 12 pubertal and 7 pre-pubertal children (age range 7-17 years) on regular hemodialysis for chronic renal failure (CRF). The results were expressed as a ratio of observed/predicted. Total body water (TBW) was normal and extracellular water (ECW) was significantly increased in both groups. Intracellular water (ICW), which reflects body cell mass, was significantly decreased in the pre-pubertal children but not in the pubertal children. The deviation in ICW from predicted normal was significantly more marked in the prepubertal children compared with pubertal children. Similarly, fat-free solids (FFS) were significantly decreased in the pre-pubertal, but normal in the pubertal children. Total body fat, estimated from body water, correlated significantly with skinfold thickness measurements and was normal in both groups, with the pre-pubertal children having significantly higher body fat ratio than pubertal children. Body fat was increased in some of the patients whose body cell mass was decreased. It is suggested that these changes are the result of a failure of normal energy metabolism with consequent body protein depletion, and that energy supplements as carbohydrate, particularly in the pre-pubertal patients, will increase body fat without affecting cell mass.

Adolescent↗
PubMed1980

The mechanism of proton translocation driven by the respiratory nitrate reductase complex of Escherichia coli.

Low concentrations (1-50mum) of ubiquinol(1) were rapidly oxidized by spheroplasts of Escherichia coli derepressed for synthesis of nitrate reductase using either nitrate or oxygen as electron acceptor. Oxidation of ubiquinol(1) drove an outward translocation of protons with a corrected -->H(+)/2e(-) stoichiometry [Scholes & Mitchell (1970) J. Bioenerg.1, 309-323] of 1.49 when nitrate was the acceptor and 2.28 when oxygen was the acceptor. Proton translocation driven by the oxidation of added ubiquinol(1) was also observed in spheroplasts from a double quinone-deficient mutant strain AN384 (ubiA(-)menA(-)), whereas a haem-deficient mutant, strain A1004a, did not oxidize ubiquinol(1). Proton translocation was not observed if either the protonophore carbonyl cyanide m-chlorophenylhydrazone or the respiratory inhibitor 2-n-heptyl-4-hydroxyquinoline N-oxide was present. When spheroplasts oxidized Diquat radical (DQ(+)) to the oxidized species (DQ(++)) with nitrate as acceptor, nitrate was reduced to nitrite according to the reaction: [Formula: see text] and nitrite was further reduced in the reaction: [Formula: see text] Nitrite reductase activity (2) was inhibited by CO, leaving nitrate reductase activity (1) unaffected. Benzyl Viologen radical (BV(+)) is able to cross the cytoplasmic membrane and is oxidized directly by nitrate reductase to the divalent cation, BV(++). In the presence of CO, this reaction consumes two protons: [Formula: see text] The consumption of these protons could not be detected by a pH electrode in the extra-cellular bulk phase of a suspension of spheroplasts unless the cytoplasmic membrane was made permeable to protons by the addition of nigericin or tetrachlorosalicylanilide. It is concluded that the protons of eqn. (3) are consumed at the cytoplasmic aspect of the cytoplasmic membrane. Diquat radical, reduced N-methylphenazonium methosulphate and its sulphonated analogue N-methylphenazonium-3-sulphonate (PMSH) and ubiquinol(1) are all oxidized by nitrate reductase via a haem-dependent, endogenous quinone-independent, 2-n-heptyl-4-hydroxyquinoline N-oxide-sensitive pathway. Approximate-->H(+)/2e(-) stoichiometries were zero with Diquat radical, an electron donor, 1.0 with reduced N-methylphenazonium methosulphate or its sulphonated analogue, both hydride donors, and 2.0 with ubiquinol(1) (QH(2)), a hydrogen donor. It is concluded that the protons appearing in the medium are derived from the reductant and the observed-->H(+)/2e(-) stoichiometries are accounted for by the following reactions occurring at the periplasmic aspect of the cytoplasmic membrane.: [Formula: see text]

Escherichia coli↗
PubMed1980

The role of the membrane-bound hydrogenase in the energy-conserving oxidation of molecular hydrogen by Escherichia coli.

H2-dependent reduction of fumarate and nitrate by spheroplasts from Escherichia coli is coupled to the translocation of protons across the cytoplasmic membrane. The leads to H+/2e- stoicheiometry (g-ions of H+ translocated divided by mol of H2 added) is approx. 2 with fumarate and approx. 4 with nitrate as electron acceptor. This proton translocation is dependent on H2 and a terminal electron acceptor and is not observed in the presence of the protonophore carbonyl cyanide m-chlorophenylhydrazone and the respiratory inhibitor 2-n-heptyl-4-hydroxyquinoline N-oxide. H2-dependent reduction of menadione and ubiquinone-1 is coupled to a protonophore-sensitive, but 2-n-heptyl-4-hydroxy-quinoline N-oxide-insensitive, proton translocation with leads to H+/2e- stoicheiometry of approx. 2. H2-dependent reduction of Benzyl Viologen (BV++) to its radical (BV+) liberates protons at the periplasmic aspect of the cytoplasmic membrane according to the reaction: H2 + 2BV++ leads to 2H+ + 2BV+. It is concluded that the effective proton translocation observed in the H2-oxidizing segment of the anaerobic respiratory chain of Escherichia coli arises as a direct and inevitable consequence of transmembranous electron transfer between protolytic reactions that are spatially separated by a membrane of low proton-permeability.

Escherichia coli↗
PubMed1980

The effects of anabolic steroids on growth, body composition, and metabolism in boys with chronic renal failure on regular hemodialysis.

Eight boys aged 9.5 to 17 years, on regular hemodialysis for chronic renal failure, were treated for 0.4 to 1.3 years with the anabolic steroid oxandrolone. The effects on linear growth, skeletal maturation, cell mass, and the fasting levels and response to intravenous glucose of BG, IRI, NEFA, BCAA, and IRG were measured. Following treatment there was a significant increase in mean growth velocity, growth velocity standard deviation score related to bone age, and cell mass. Overall skeletal maturation was not accelerated, and only a small advance in pubertal status was seen. There was a decrease in fasting levels of BG and NEFA; fasting BCAA and IRG were increased. The response to intravenous glucose was altered; there was a decrease in peak BG response, an increase in peak IRI response, and a more marked fall in plasma NEFA and BCAA levels. Fasting IRG levels correlated with fasting BG levels, and fell significantly following intravenous glucose both before and after treatment. Hepatotoxicity, which was reversible, was seen in a ninth boy who did not complete the study. The only other side effect, salt and water retention, was controlled by a reduction in oxandrolone dosage. These preliminary results suggest that anabolic steroids may be useful to stimulate anabolism and growth in uremic children, and that their effect is mediated by an increase in insulin secretion and/or an improvement in tissue sensitivity to insulin. Further studies with careful monitoring are required to substantiate the effect on final height and the risks involved.

Adolescent↗