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Biomedical subjects

C Hall

Publications and source records attributed to C Hall.

At least 325 records · Page 18Linked to original sources
PubMed1985

Gastric ulcer localization by direct in vivo labeling of sucralfate. Work in progress.

We developed and evaluated a new procedure for imaging gastric ulcer disease with technetium 99m-labeled sucralfate. The new method employs direct in vivo labeling of sucralfate instead of in vitro labeling using human serum albumin, as previously reported in the literature. Tests using hydrochloric acid and a rabbit ulcer model showed the efficacy of the direct in vivo labeling technique and the ability of the tagged material to bind to ulcers, respectively. In 26 studies using humans with sucralfate labeled directly in vivo, 15 gave true-negative results and 11 gave true-positive results. Of 14 studies using humans with in vitro labeled sucralfate, three gave true-negative results, three gave true-positive results, and the results of eight were either false-negative or could not be interpreted because of high levels of activity remaining in the stomach. We suggest that the direct in vivo labeling method significantly improves the sucralfate gastric ulcer imaging technique.

Aluminum↗
PubMed1985

Footnotes to food tables. 2. The underestimations of intakes of lesser B vitamins by pregnant and lactating women as calculated using the fourth edition of McCance and Widdowson's 'The composition of foods'.

In McCance & Widdowson's 'The composition of foods' many items lack information on the content of the lesser B vitamins, and dietary intakes can therefore be underestimated. The degree of this underestimation was assessed using data from a longitudinal study of the food intake of 63 pregnant and lactating mothers in Cambridge, UK, with a total of 3185 days of weighed diet records. The extra mean daily additional intake of each vitamin contributed by foods eaten by the mothers but lacking data in the food tables was estimated to be: vitamin B12, 0.1 micrograms, (1.5 per cent of total intake); vitamin B6, 0.04 mg (3.3 per cent); total folate, 10 micrograms (5.3 per cent); pantothenic acid, 0.6 mg (11.5 per cent); and biotin, 5 mg (14.3 per cent). Although many items in the tables lack data, most were eaten infrequently and made little contribution to vitamin intake. It was estimated that, if data were added for a limited number of frequently-eaten foods, namely, white toast, baked beans, biscuits, breakfast cereals and 'chicken with skin', then intakes of all five vitamins would be underestimated by less than 4 per cent.

Diet↗
PubMed1985

The effects of internal and external imagery on performing figures in figure skating.

The influence of mental imagery perspective on figure skating performance was investigated. Fifty-nine skaters, who were in attendance at the Canadian Figure Skating Association's National Singles Seminar, participated in the study. Subjects performed a modified senior level figure as a pre-test measure, and then were randomly assigned to one of four treatment groups: an internal kinesthetic imagery group, an internal visual imagery group, an external visual imagery group, and a control training group. All treatment groups underwent four training sessions. Post-test performance revealed no significant differences between the three types of imagery training, and imagery training subjects failed to perform significantly better than control subjects. However, senior skaters showed both greater performance improvements and were superior kinesthetic imagers than novice skaters.

Adolescent↗
PubMed1984

The relationship of the rat brain 68 kDa microtubule-associated protein with synaptosomal plasma membranes and with the Drosophila 70 kDa heat-shock protein.

A protein of molecular mass 68 kDa and pI5.6 is a major translation product of rat brain mRNA [Hall, Mahadevan, Whatley, Biswas & Lim (1984) Biochem. J. 219, 751-761]. In the rat brain this protein was associated with microtubule preparations and was present together with tubulin as a component of the synaptosomal plasma membranes, synaptic vesicles and post-synaptic structures. The brain mRNA for this protein was found to hybridize specifically to the Drosophila gene for the 70 kDa heat-shock protein, thus enabling its rapid isolation.

Animals↗
PubMed1984

Alterations in the relative amounts of specific mRNA species in the developing human brain in Down's syndrome.

Total cellular polyadenylated RNA [poly(A)+ RNA] was prepared after guanidinium thiocyanate extraction of frozen brain tissue from age-matched normal and Down's-syndrome (trisomy 21) human foetuses. Poly(A)+ RNA populations were analysed by translation in vitro, followed by two-dimensional gel analysis by using both isoelectric focusing (ISODALT system) and non-equilibrium pH-gradient electrophoresis (BASODALT system) as the first-dimension separation. The relative concentrations of poly(A)+ RNA species coding for seven translation products were significantly altered in Down's syndrome, as determined by both visual comparisons of translation-product fluorograms from normal and Down's-syndrome samples and by quantitative radioactivity determination of individual translation products. The relative concentrations of mRNA species coding for two proteins (68 kDa and 49 kDa) were increased in Down's syndrome and may represent genes located on chromosome 21. The relative concentrations of mRNA species coding for five proteins (37 kDa, 35 kDa, 25.5 kDa, 24.5 kDa, 23 kDa) were decreased in Down's syndrome, these probably representing secondary effects of the trisomy. Six Down's-syndrome-linked translation products (49 kDa, 37 kDa, 33 kDa, 25.5 kDa, 24.5 kDa, 23 kDa) did not migrate with appreciable amounts of cellular proteins on two-dimensional gels and hence may represent either proteins of high turnover rates or those that are post-translationally modified in vivo. One translation product (68 kDa) comigrated with a major cellular protein species, which was identified as a 68 kDa microtubule-associated protein by limited peptide mapping. The significance of these changes is discussed in relation to the mechanisms whereby the Down's-syndrome phenotype is expressed in the human brain.

Brain↗
PubMed1984

An enveloped virus in stools of children and adults with gastroenteritis that resembles the Breda virus of calves.

Pleomorphic virus-like particles about 100 nm in diameter with a fringe of closely applied peplomers (7-9 nm in length) were observed by electron microscopy in the stools of 20 children and adults with gastroenteritis. In most of the samples no other viral or bacterial pathogens were detected. In form and under immune electron microscopy these virus-like particles resembled the Breda virus isolated from diarrhoeic calves. These objects may be a viral pathogen of humans.

Adult↗
PubMed1984

Characterization of translation products of the polyadenylated RNA of free and membrane-bound polyribosomes of rat forebrain.

Poly(A)+ RNA (polyadenylated RNA) isolated from membrane-bound and free polyribosomes was translated in reticulocyte lysates, and the products were analysed by two-dimensional gel electrophoresis. Several translation products were specific to membrane-bound polyribosomal mRNA, including polypeptides of 47kDa, 35kDa and 21 kDa, whereas others (e.g. of 37 kDa, 17 kDa and 14 kDa) were specific to free polyribosomal mRNA. Although many products were common to both mRNA species, cross-contamination could be ruled out on the basis of the presence of these and other specific products. The common products included a 68 kDa microtubule-associated protein, tubulin, actin, the brain form of creatine kinase, neuron-specific enolase and protein 14-3-3 and calmodulin, all of which were identified on the basis of two-dimensional gel and peptide analyses. The 35 kDa protein product of membrane-specific mRNA was co-translationally processed in vitro by microsomal membranes, resulting in its cleavage to 33 kDa (and partial glycosylation). The 33 kDa processed protein (but not the 35 kDa precursor) was integrated into both dog pancreas and rat brain microsomal membranes. The occurrence of the enzymes and calmodulin as products of membrane-bound polyribosomal mRNA is discussed in the light of their presence on rat brain synaptic plasma membranes [Lim, Hall, Leung, Mahadevan & Whatley (1983) J. Neurochem. 41, 1177-1182] and their existence in a specific component of axonal flow. It is suggested that some of these translation products of the rough endoplasmic reticulum may represent proteins destined for the plasma membrane. However, the identity and location of the 35 kDa membrane-specific product (or its processed form) still remain unestablished.

Animals↗
PubMed1984

Isolation and characterization of a mouse cDNA clone that expresses mast-cell growth-factor activity in monkey cells.

A cDNA sequence coding for mouse mast-cell growth-factor (MCGF) has been cloned from a cDNA library prepared from mRNA derived from a concanavalin A-activated mouse T-cell clone. Cloning was achieved using the pcD vector that permits expression of cDNA inserts in mammalian cells. The DNA sequence codes for a polypeptide of 166 amino acid residues including a putative signal peptide. The supernatant fluid obtained after transfection of COS-7 monkey cells with the pcD-MCGF plasmid had mouse MCGF activity. The MCGF amino acid sequence between amino acids 33 and 41, deduced from the nucleotide sequence of its cDNA, is identical to the NH2-terminal sequence of the mouse lymphokine, interleukin 3, suggesting that MCGF is related to interleukin 3.

Amino Acid Sequence↗
PubMed1984

Effect of ACE-Inhibition on regional blood flow during acute left ventricular failure in the dog. Preliminary report.

Acute left ventricular failure was induced in 7 anaesthetized dogs by embolization of the left coronary circulation with 57 micron plastic microspheres. The dogs were then subjected to ACE-inhibition with enalapril. In addition to hemodynamic measurements, tissue blood flow was measured with the radioactive microsphere method. Preliminary results are presented, showing the vasodilatory effects of enalapril to be greatest in stomach, muscle and brain while possibly compromising the renal circulation.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1983

Does 111indium-platelet deposition predict patency in prosthetic arterial grafts?

The relationship between the rate of 111In-platelet deposition on vascular grafts and subsequent thrombosis has been examined in patients undergoing femoropopliteal by-pass. Sixty-seven patients undergoing femoropopliteal by-pass using vein, Dacron or PTFE were randomized to aspirin plus dipyridamole (ASA/DPM) or placebo. Autologous 111In-platelets were injected in the second postoperative week and Thrombogenicity Index (TI) calculated as the mean daily rise in the ratio of radioactivity graft/contralateral thigh. Graft patency was assessed to 1 year. Mean (+s.e.m.) TI at 1 week in 21 grafts that occluded within 12 months was 0.19 +/- 0.018 compared with 0.07 +/- 0.009 in the 38 that remained patient (P less than 0.001). Grafts with a TI less or greater than the median had a 90 per cent or 39 per cent cumulative 1-year patency, respectively (P less than 0.001). In the prosthetic grafts ASA/DPM reduced mean TI from 0.17 +/- 0.02 to 0.11 +/- 0.01 (P less than 0.02) and enhanced 1-year patency from 36 to 67 per cent (P less than 0.05). Following femoropopliteal by-pass TI related to subsequent graft patency. Radiolabelled platelet deposition therefore provides a guide as to how new materials or antithrombotic drugs may influence clinical graft thrombosis. Platelet inhibition reduced both graft thrombogenicity and subsequent occlusion.

Aspirin↗
PubMed1983

Dazoxiben examined for platelet inhibitory effect in an artificial circulation.

1 Platelet inhibitory therapy may protect patency in prosthetic arterial grafts. 2 The effect of the thromboxane synthetase inhibitor dazoxiben (UK 37248) on 113Indium-labelled platelet deposition on Dacron arterial grafts was examined in an artificial circulation containing human blood which mimics the haemodynamics of femoropopliteal bypass. The influence of this drug on thromboxane production and platelet reactivity was measured during the experiment. The study was controlled and performed in two parts to assess in vitro and ex vivo drug effect. 3 Both in vitro and ex vivo dazoxiben reduced plasma thromboxane by about 80% and in citrated ex vivo blood increased mean (+/- s.e. mean) platelet aggregation threshold to collagen from control values of 4.8 +/- 1.7 mg/ml to 10.6 +/- 3.3 mg/ml (P less than 0.01). Dazoxiben, however, had no effect on platelet deposition on the arterial grafts. 4 Selective thromboxane inhibition failed to exert an antithrombotic effect in this model.

Adult↗
PubMed1983

A time for reflection.

The nursing profession in the United Kingdom is faced with great opportunities for significant developments. To make best use of these it is necessary to reflect on the past, to meditate on key issues which are current, to plan wisely and well for the future and then to press ahead with determination. Key issues highlighted are in the spheres of education, management and practice; the need for research is emphasized. The pay structure can either support or impede developments, as can the attitude of the medical profession; the nursing and medical professions are complementary and interdependent, understanding between them is essential and effective communications are core to its realization. A general goal identified is the achievement of a more cohesive profession, a modification of the divisions between education, management and practice which, it is contended, have intensified as developments have taken place in each of these spheres. Objectives for development are put forward in the context of current circumstances which, it is argued facilitate their promotion. Signs that the nursing profession now recognizes the need for unified action to achieve its objectives are seen as encouraging, and confidence is expressed that the profession will exploit the opportunities now within its grasp.

Education, Nursing↗
PubMed1983

Neurone-specific enolase and creatine phosphokinase are protein components of rat brain synaptic plasma membranes.

Neuron-specific enolase and creatine phosphokinase were found, by 2-dimensional gel analysis, in rat brain synaptic plasma membranes (SPM). The identity of these enzymes was confirmed by comigration with purified rat brain NSE and CPK and by peptide analysis. The specific enzymatic activities of enolase and creatine phosphokinase, as well as of pyruvate kinase, also present on the membranes, were comparable to those in the homogenates when these three enzymes were fully activated. In the SPM all three enzymes, particularly enolase, were partially cryptic in that enzymatic activities were very low unless the membranes were treated with Triton X-100. They were resistant to both low-salt and high-salt extraction and to trypsin, except when Triton X-100 was present. These results suggest that the enzymes are tightly bound protein components of the membrane and that they may constitute an assembly capable of generating ATP.

Animals↗
PubMed1983

The plasma membrane origin of liver-specific protein (LSP).

Liver-specific lipoprotein (LSP) is a potentially important target antigen for autoimmune liver cell injury, but the complexity of LSP "the preparation" has hindered investigation of anti-LSP immune responses. In the present study, rabbit LSP and isolated liver plasma membranes (LPM) were compared using electron microscopy and marker enzyme analysis to determine the subcellular site of origin of LSP. These results suggest that LSP "the preparation" is highly enriched with plasma membrane.

Animals↗