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Biomedical subjects

D Barton

Publications and source records attributed to D Barton.

At least 55 records · Page 3Linked to original sources
PubMed1990

Amniotic fluid ingestion enhances opioid-mediated but not nonopioid-mediated analgesia.

Ingestion of amniotic fluid or placenta by rats has been shown to enhance several types of opioid-mediated analgesia: that induced by morphine, footshock, vaginal/cervical stimulation, and late pregnancy. This enhancement has also been blocked by administration of opioid antagonists. The present study was designed to examine further the specificity of the enhancement effect for opioid-mediated analgesia by testing for enhancement following administration of aspirin, a nonopioid analgesic. The formalin test was used as the pain threshold assay. Amniotic fluid or beef bouillon was administered by orogastric tube to rats that were treated either with morphine sulfate or saline, or pretreated with naltrexone, then treated with aspirin or vehicle. Both morphine and aspirin treatments produced analgesia. Amniotic fluid significantly enhanced the analgesia produced by morphine, but did not enhance the analgesia produced by aspirin, further suggesting that the enhancing effect of amniotic fluid ingestion is specific for opioid-mediated analgesia, such as that existing at the start of parturition.

Amniotic Fluid↗
PubMed1990

Flying Squad response to medical emergencies.

The Flying Squad of the Accident and Emergency Department, of the Derbyshire Royal Infirmary, was established in 1955 by Collins. The initial function was to provide emergency care to victims of industrial accidents. However, the spectrum of emergencies they now respond to has expanded and includes predominantly road traffic accidents and medical emergencies. Despite the proliferation of Flying Squads their benefit has been difficult to quantify even in a trauma setting (Robertson & Steedman, 1985; Gorman & Coals, 1983). The outcome in medical emergencies is reported as dismal (Robertson & Steedman, 1985; Rowley & Collins, 1979) yet the number of calls for the flying squad to attend medical emergencies are many. Previous reports have recorded 20-30% of Squad calls responding to medical emergencies (Gorman & Coals, 1983; Rowley & Collins, 1979; Steedman & Robertson, 1986; Harrop & Bodiwala, 1983).

Cardiopulmonary Resuscitation↗
PubMed1990

An audit of road traffic accident victims requiring admission to hospital.

In this retrospective study, the case notes of all road traffic accident (RTA) victims admitted to one hospital during a 12 month period (1986-1987) were analysed. One hundred and twenty five patients were identified. The male/female ratio was 2:1 and the mean age was 34 years. The peak time of hospital arrival was midnight-1 am (18 cases, 15.6%) followed by the period 21.00-22.00 (10 cases, 18.6%. A total of 84 cases (73%) arrived between 17.00-8.00. The mean time spent in the accident and emergency department was 180 minutes. The severity of the victims' injuries was evaluated, using the Injury Severity Score (ISS). The mean ISS score was 9, with a range 1-75. There was a 33% mortality for patients with an ISS of 12 or more. Initial assessment of the RTA victims was performed by the SHO in 77% and by the registrar in 23% of cases. It is paramount that RTA victims with multiple injuries are rapidly transferred to an appropriate centre with the necessary expertise and facilities.

Abbreviated Injury Scale↗
PubMed1989

Adrenal glucocorticoids regulate adipsin gene expression in genetically obese mice.

Adipsin expression at the protein and mRNA levels is greatly reduced in several distinct syndromes of obesity in the mouse: genetic obesity due to the db/db and ob/ob genes, and a chemically induced model secondary to neonatal exposure to monosodium glutamate. We considered first the possibility that the adipsin gene might be identical to the db or ob locus and the lowered expression of this protein might result from a mutation in this gene. We show here that the adipsin structural gene is located on chromosome 10 and hence is physically distinct from any obesity genes so far identified in the mouse. A major role for the adrenal gland and adrenal glucocorticoids in the aberrant regulation of adipsin in these models of obesity is indicated by several experiments. Adrenalectomy of the ob/ob mouse raises the circulating levels of adipsin protein and the amount of this mRNA in epididymal fat pads (5-fold), although neither is increased to the levels seen in lean controls. Exogenous administration of corticosterone completely blocks the effects of adrenalectomy on adipsin, suggesting that the effect of this endocrine ablation is through reduction of adrenal glucocorticoids. Corticosterone administration also causes suppression in the levels of adipsin mRNA and protein in lean mice, although this decrease is never as severe as that seen in obese mice. The effect of exogenous corticosterone in lean mice occurs within 2 days and hence is not secondary to the obesity which these hormones eventually elicit. These results indicate that glucocorticoids can regulate adipsin expression in vivo and strongly suggest that the hyperglucocorticoid state seen in certain obese models plays a significant role in lowering adipsin mRNA and protein levels. Quantitative analysis of these experiments suggests that other as yet unknown neuroendocrine factors also function to suppress adipsin in obesity.

Adipose Tissue↗
PubMed1989

Radiological assessment of atlanto-axial injuries.

Injury to the cervical spine is a potentially lethal condition, and the accurate detection of such injury is essential. Plain cervical radiography remains the first line of investigation, despite well documented difficulty with interpretation. There have been many studies demonstrating unreliability of plain cervical radiography in detecting atlanto-axial injuries. We report a group of patients in which false-positive interpretation of such injuries occurred.

Accidents↗
PubMed1989

Chromosomal localization of the gene for the human trifunctional enzyme, methylenetetrahydrofolate dehydrogenase-methenyltetrahydrofolate cyclohydrolase-formyltetrahydrofolate synthetase.

A trifunctional protein in man, 5,10-methylenetetrahydrofolate dehydrogenase-5,10-methenyltetrahydrofolate cyclohydrolase-10-formyltetrahydrofolate synthetase, catalyzes three consecutive steps in the interconversion of tetrahydrofolate derivatives; these derivatives supply one-carbon units for intermediary metabolism. Somatic cell hybridization and in situ hybridization were used to localize the functional gene coding for this protein--to human chromosome 14q24, near the c-fos and TGF-beta 3 loci. A second hybridizing sequence, possibly a pseudogene, was identified near the centromere of the X chromosome, at Xp11.

Aminohydrolases↗
PubMed1988

The metabolic impact of active ulcerative colitis. Energy expenditure and nitrogen balance.

Resting energy expenditure and nitrogen balance were measured shortly after admission and shortly before discharge or colectomy in eight adult males hospitalized for active ulcerative colitis. The measured resting energy expenditure was 19% higher than that predicted by the Harris-Benedict formula (p less than 0.01). Fecal and urinary nitrogen losses were 2.1 +/- 1.5 g/day and 13.6 +/- 3.8 g/day, respectively. During the early hospitalization period, daily intakes of calories (1,826 +/- 1,050 kcal) and protein (1.5 +/- 0.4 g/kg) were not sufficient to maintain energy (-548 +/- 964 kcal/day) and nitrogen (-1.5 +/- 3.9 g/day) balances. Energy expenditure and nitrogen losses at the end of the study were similar to the values obtained on admission, but because of a voluntary increase in caloric (by 42%) and protein (by 37%) intake during the hospitalization both energy balance (+434 +/- 409 kcal/day) and nitrogen balance (+4.6 +/- 6.5 g/day) (p less than 0.05) improved. These results suggest that, although the metabolic impact of active ulcerative colitis is mild, it does result in negative energy and nitrogen balances. Dietary intake can be voluntarily increased during hospitalization to improve energy and nitrogen equilibrium.

Adult↗
PubMed1988

Comparison of nonerythroid alpha-spectrin genes reveals strict homology among diverse species.

The spectrins are a family of widely distributed filamentous proteins. In association with actin, spectrins form a supporting and organizing scaffold for cell membranes. Using antibodies specific for human brain alpha-spectrin (alpha-fodrin), we have cloned a rat brain alpha-spectrin cDNA from an expression library. Several closely related human clones were also isolated by hybridization. Comparison of sequences of these and other overlapping nonerythroid and erythroid alpha-spectrin genes demonstrated that the nonerythroid genes are strictly conserved across species, while the mammalian erythroid genes have diverged rapidly. Peptide sequences deduced from these cDNAs revealed that the nonerythroid alpha-spectrin chain, like the erythroid spectrin, is composed of multiple 106-amino-acid repeating units, with the characteristic invariant tryptophan as well as other charged and hydrophobic residues in conserved locations. However, the carboxy-terminal sequence varies markedly from this internal repeat pattern and may represent a specialized functional site. The nonerythroid alpha-spectrin gene was mapped to human chromosome 9, in contrast to the erythroid alpha-spectrin gene, which has previously been assigned to a locus on chromosome 1.

Amino Acid Sequence↗
PubMed1988

An endostomal tracheostomy tube for leakproof retention of the Blom-Singer stomal valve.

Patients in whom fistula speech has developed after laryngectomy usually have to occlude their stoma with a finger to talk. This prevents the air that is needed to activate the fistula from being exhaled through the stoma. In order to free the hand, Blom and Singer devised a diaphragm-valved stomal device known as the tracheostoma valve. This device snaps into a flexible retention housing that must be carefully cemented to the skin. Some patients who have undergone near-total laryngectomy (and others with tracheo-esophageal voice prostheses) are unable to use their devices because the moisture and pressure around their stomas break the seal. Since air that is used to produce voice with the valve tends to lift the housing away from the stoma, a better housing design would assure that this motion would improve the seal.

Aged↗
PubMed1987

Isolation of cDNA clones coding for rat isovaleryl-CoA dehydrogenase and assignment of the gene to human chromosome 15.

Rat liver mRNA encoding the cytoplasmic precursor of mitochondrial isovaleryl-CoA dehydrogenase was highly enriched by polysome immunopurification using a polyclonal monospecific antibody. The purified mRNA was used to prepare a plasmid cDNA library which was screened with two oligonucleotide mixtures encoding two peptides in the amino-terminal portion of mature rat isovaleryl-CoA dehydrogenase. Thirty-one overlapping cDNA clones, spanning a region of 2.1 kbp, were isolated and characterized. The cDNA sequence of a 5'-end clone, rIVD-13 (155 bp), predicts a mitochondrial leader peptide of 30 amino acid residues and the first 18 amino acids of the mature protein. These consecutive 18 residues completely matched the amino-terminal peptide determined by automated Edman degradation of the rat enzyme. The leader peptide contains six arginines, has no acidic residues, and is particularly rich in leucine, alanine, and proline residues. Southern blot analysis of DNAs from human-rodent somatic cell hybrids with an isolated rat cDNA (2 kbp) assigned the isovaleryl-CoA dehydrogenase gene to the long arm of chromosome 15, region q14----qter. The chromosomal assignment was confirmed and further refined to bands q14----q15 by in situ hybridization of the probe to human metaphase cells. This location differs from that of the gene for medium-chain acyl-CoA dehydrogenase, a closely related enzyme, which has been previously assigned to chromosome 1.

Animals↗
PubMed1985

Prepubertal testicular torsion: subsequent fertility.

Eighteen patients were reviewed 7 to 23 years after prolonged unilateral testicular torsion. They had all undergone surgical untwisting with replacement of the nonviable testis in the scrotum during prepubertal period. Five patients were now married and had fathered one or more children. Thirteen patients were unmarried. There was absence of testis on the affected side in 14 of 18 patients. Four patients had severe testicular atrophy on the affected side (testicular volume less than 1 mL). The contralateral side showed either a normal testicular volume or a compensatory hypertrophy (testicular volume greater than 25 mL). Seminal analysis was done in 13 unmarried men and it was completely normal in 10 patients. Two patients had low sperm density but normal semen volume and motility. One patient had pathologic semen analysis. IgG and IgA specific mixed agglutination reaction (MAR) test did not show evidence of sperm autoantibodies in any patient. Our clinical experience shows that, after prepubertal torsion, the contralateral testis undergoes normal development. Furthermore, torsion in the prepubertal male does not cause autosensitization and diminished fertility in adult life.

Adolescent↗
PubMed1983

Isolation of a polymorphic DNA segment unique to human chromosome 7 by molecular cloning of hybrid cell DNA.

DNA isolated from a rodent-human hybrid cell line containing human chromosomes 3, 7, 9, 10, 14 and 22 was cloned in the plasmid vector pAT153. Recombinant plasmids containing inserts of human origin were identified by colony hybridization to 32P-labelled human DNA under conditions in which only repetitive sequences interact. Single- and low-copy sequences were liberated from these plasmids by restriction endonuclease digestion and used as hybridization probes against human DNA and DNA isolated from a panel of Chinese hamster-human hybrids. One single-copy probe was shown to react with a genomic sequence unique to human chromosome 7 and to recognize an apparent restriction fragment size polymorphism in human DNA.

Animals↗