Biomedical subjects

L C Ward

Publications and source records attributed to L C Ward.

At least 109 records · Page 6Linked to original sources

PubMed1987

Protein synthesis in the tumour-bearing rat.

The rates of protein synthesis in liver, muscle and tumour of animals bearing either a rapidly growing (7288c) or slow-growing (5123c) hepatoma were determined. Liver protein synthesis was increased whilst, in contrast, protein synthesis in muscle decreased. Tumour protein synthesis comprised between 15% and 43% of total body protein synthesis. Since food intake of tumour-bearing animals was not significantly different from that of controls, these changes were not attributable to an anorexic component of the tumour-bearing state but may reflect a systemic tumour-mediated effect.

Animals↗

PubMed1987

Amino acid supply and protein metabolism in Ehrlich ascites tumour cells. 2. Incorporation of 14C-tyrosine.

The incorporation of 14C-tyrosine into protein of incubated Ehrlich ascites tumour cells was measured over a 10-fold range of external amino acid concentrations, the composition of which simulated that of mouse intraperitoneal fluid. Incorporation was linear with time and the rate of incorporation increased with increasing external amino acid concentration up to at least six times intraperitoneal concentrations. Further increases in external amino acid supply did not yield a concomitant increase in the rate of tyrosine incorporation, a maximum fractional protein synthetic rate of approximately 100% d-1 being achieved. The specific activity of tyrosine in intracellular fluid was approximately 95% of that of extracellular fluid, irrespective of the external amino acid concentration.

Amino Acids↗

PubMed1987

Amino acid supply and protein metabolism in Ehrlich ascites tumour cells. 1. Identification of limiting amino acids.

The uptake and intracellular accumulation of an amino acid mixture by incubated Ehrlich ascites tumour cells was studied. The composition of the amino acid mixture simulated that of mouse intraperitoneal fluid and amino acid uptake was studied over a range of concentrations between 0.0 (no added amino acids) and 10.0-times intraperitoneal concentrations. For most amino acids uptake into cells and intracellular accumulation occurred as concentrations were increased up to 6.0-times the intraperitoneal concentrations; further increases in external amino acid concentrations did not increase concomitantly with intracellular concentrations. These data, when analysed indicated a net protein synthetic rate of 20% d-1 and that the rate of protein synthesis may be limited by the availability of the amino acids lysine, threonine and methionine.

Amino Acids↗

PubMed1986

Estimation of MMPI scale scores from an improved comprehensibility short form.

Equations were derived for estimating MMPI scores from a short form that was developed for cognitively impaired individuals. Multiple regression analyses of the data on 300 patients demonstrated that prediction from a single short-form scale was acceptable and was little improved by the addition of other scales or sex of subject to the prediction equation. Substitution equations were constructed, and correlations of short-form scales with the full MMPI ranged from .82 to .96 with a median of .91.

Adult↗

PubMed1986

Identification of cystic fibrosis homozygotes and heterozygotes by isoelectric focusing of serum proteins.

Screening of 44 cystic fibrosis homozygotes, 17 heterozygotes and 36 normal controls, by identification of cystic fibrosis protein (CFP), was performed on sera using an improved isoelectric focusing technique. CFP was observed in 91% of homozygotes, 88% of heterozygotes and 8% of normal controls tested. Partial purification of CFP by chromatofocussing indicates that CFP has a molecular weight of about 52,000 u. It is speculated that CFP is a normal serum protein that exhibits a quantitative difference in concentration between CF homozygotes, heterozygotes and normals.

Blood Proteins↗

PubMed1986

Acetaldehyde and cardiac protein synthesis in the rat in vivo.

Protein synthesis was measured in the hearts of rats exposed to acetaldehyde vapour for 21 days. Exposure to acetaldehyde significantly increased heart weight (expressed as % body weight) but was without effect on the rate of synthesis of mixed cardiac proteins. Concentrations of RNA in the hearts were not altered by acetaldehyde exposure, indicating no change in RNA activity for protein synthesis.

Acetaldehyde↗

PubMed1986

Cellular energy charge in the heart and liver of the rat. The effects of ethanol and acetaldehyde.

The effects of ethanol and acetaldehyde upon adenine nucleotide concentrations in rat heart and liver were determined. Ethanol administered either acutely (8 g kg 0.73) or chronically (20% solution in drinking water for 21 d) significantly decreased ATP concentrations, adenylate energy charge (EC) and adenylate kinase mass action ratio (gamma AK) in liver but affected gamma AK only in heart. Acetaldehyde treatment elicited similar effects but of lesser magnitude.

Acetaldehyde↗

PubMed1986

Nutritional rehabilitation in cystic fibrosis: controlled studies of effects on nutritional growth retardation, body protein turnover, and course of pulmonary disease.

The effects of a sustained increase in energy and protein intake on weight gain, growth, body protein metabolism, and the course of pulmonary disease were studied in 10 undernourished patients with cystic fibrosis unable to maintain nutrition and growth by the oral route and with declining nutritional and pulmonary status in the year prior to study. A 1-year course of nutrient supplementation using a semielemental high-nitrogen formula was delivered by nocturnal intragastric feeding or as an orally administered supplement; progress was compared with that of 14 height-, sex- and FEV1-matched patients with cystic fibrosis receiving conventional therapy. Supplementation resulted in a catch-up weight gain and sustained improvement in linear growth, with fewer pulmonary infections per year than during the initial observation period. Better weight gain and linear growth than in the comparison group were observed, as well as a significant reversal of the trend for deteriorating lung function. Compared with data from healthy children, 15N-glycine kinetics demonstrated increased protein breakdown and negligible net protein deposition in the treatment group prior to supplementation. After supplementation, synthesis in excess of breakdown, with net protein accretion, occurred by 1 month of supplementation. By 6 to 12 months a significant reduction in the previously high rate of mean synthesis and breakdown was observed, with maintenance of net anabolism. These dynamic changes in whole-body protein turnover reflect a long-term improvement in energy and protein intake, which can favorably affect nutrition, growth, and the course of pulmonary disease in problem cases of cystic fibrosis.

Adolescent↗

PubMed1986

MMPI item subtlety research: current issues and directions.

This article examines the methodology from recent item subtlety research with the Minnesota Multiphasic Personality Inventory (MMPI). The Christian, Burkhart, and Gynther (1978) ratings, used in this research, define item subtlety as the perceived degree of psychopathology associated with individual items rather than specifying subtlety in relation to qualities characteristic of individual scales. Consequently, the ratings often violate commonsense notions of subtlety, and the results of research with the ratings are difficult to interpret. Studies with the ratings also contain procedural defects which limit generality. It is recommended that future investigators give greater consideration to the operational definition of item subtlety, to the intended applications of the MMPI, and to item properties other than simple correlations with criteria that can enhance the predictive and discriminative powers of MMPI scales.

Humans↗

PubMed1986

Ornithine decarboxylase activity and actin polymerization in testosterone--stimulated mouse kidney.

Renal hypertrophy was induced in mice by injection of testosterone. Associated with an increase in renal tissue mass were increases in the concentrations of spermine and spermidine and in the activity of ornithine decarboxylase (ODC), the rate limiting enzyme in their synthesis. The increased activity of ODC was shown to be due to an increase in tissue ODC content. Total tissue actin was not altered by testosterone treatment although the proportion of unpolymerized (soluble) actin was increased significantly. These data are discussed in relation to the postulated mechanism of polyamine stimulation of actin polymerization.

Actins↗

PubMed1986

Acute effects of ethanol on protein synthesis in the rat.

The effect of ethanol, administered acutely (75 mmol kg-1), on protein synthesis in the whole body and in the tissues of the rat was investigated. Ethanol decreased whole-body protein synthesis by 41% and also that in individual tissues (liver: 60%; muscle: 75%; heart: 45%; kidney: 59%; spleen: 73%; plasma protein: 44%; lung: 64%). These data indicate a generalised effect upon protein synthesis and are discussed in relation to the possible mode of action of ethanol.

Animals↗

PubMed1985

Ethanol and brain protein synthesis in the rat in vivo.

The effect of ethanol consumption (27% of calories) for 21 days, concomitant with a low-protein (6% calories) or a normal protein diet (17.5% calories), on tyrosine kinetics and protein synthesis in the brain, was investigated. Ethanol consumption did not affect tyrosine concentrations in the plasma, cerebellum, forebrain or olfactory bulb but increased significantly the rate of synthesis of total mixed protein in the forebrain and cerebellum. This effect was observed in rats fed on both dietary protein regimes.

Alcoholism↗

PubMed1985

Interrelationships of locus of control content dimensions and hopelessness.

Items from three locus of control (LOC) tests and the Beck Hopelessness Scale were administered to 197 college students. Factor analyses produced multiple factors for each LOC test, but the Beck scale proved to be unidimensional. Factor scales were constructed for each test, and scores were factor analyzed to discover common content. Each LOC test contained a salient dimension that described belief in luck, chance, or fate, and corresponding scales were well correlated. Internal control was the second common theme, with variations according to whether control was attributed to oneself or to people in general. The third common component expressed a personal helplessness or powerlessness. Each common factor was loaded by the Hopelessness Scale, which also correlated with all but one LOC factor scale.

Factor Analysis, Statistical↗

PubMed1985

Ethanol and leucine oxidation--I. Leucine oxidation by the rat in vivo.

The effect of ethanol upon the oxidation of leucine by the rat in vivo was determined. The rate of leucine oxidation was not significantly altered by chronic administration of ethanol (20% v/v solution as drinking water for 28 days). Ethanol administered acutely (8 g kg 0.73) significantly decreased leucine oxidation by the rat in vivo. This decrease appeared to be independent of a more general depression of oxidation metabolism. Decrease in leucine oxidation by ethanol is discussed in relation to the regulation of tissue leucine pool sizes in vivo.

Aminoisobutyric Acids↗

PubMed1985

Ethanol and leucine oxidation--II. Leucine oxidation by rat tissue in vitro.

The effect of ethanol upon leucine oxidation by rat tissues in vitro is reported. The activities of branched chain amino acid aminotransferase and 2-oxo acid dehydrogenase were decreased by chronic administration of ethanol (20% v/v solution as drinking water for 35 d) in muscle and kidney but were increased, although not significantly, in liver. Acute administration of ethanol (8 g kg-1 body-weight 0.73) did not affect enzyme activities. Tissue NAD+:NADH ratios, calculated from lactate:pyruvate ratios, were significantly decreased in the liver and kidney of rats receiving ethanol acutely. These data are consistent with the view that ethanol decreases leucine oxidation by decreasing availability of NAD+ when given acutely and by decreasing enzyme activity when administered chronically.

Animals↗

PubMed1985

Inhibition by ethanol of cardiac protein synthesis in the rat.

Protein synthesis and degradation were measured in the hearts of rats fed on diets containing 27% of calories as ethanol. Feeding of ethanol decreased the rate of synthesis of mixed cardiac proteins but was without effect on the rate of breakdown of myofibrillar and sarcoplasmic proteins. Concentrations of RNA in the hearts were not altered by ethanol feeding, indicating a decrease in RNA activity for protein synthesis.

Animals↗

PubMed1985

Whole body protein turnover in malnourished cystic fibrosis patients and its relationship to pulmonary disease.

To investigate the effect of pulmonary disease in cystic fibrosis (CF), total body protein synthesis and catabolism were determined in eight CF children with acute exacerbations of pulmonary infection at the time of study (CF I), a group of CF children (n = 7) with chronic but stable pulmonary disease (CF II) and a group (n = 8) of healthy children. Protein synthesis was determined by the method of Waterlow et al (1978) using a single oral dose of 15N glycine and protein catabolism derived from nitrogen balance. Protein synthesis was markedly decreased (p less than 0.001) in the CF I group (1.01 +/- 0.10 g kg-1 10 h-1) compared with that of controls (2.02 +/- 0.08) and with CF children with chronic but stable pulmonary disease (CF II) (2.36 +/- 0.17). Protein catabolism was increased (p less than 0.01) in the CF II group compared with both controls and CF I. These findings contrast strongly to studies in normal children and those with mild protein-energy malnutrition (PEM) and infection, where infection increased protein synthesis, but are consistent with the observed decrease in protein turnover where severe PEM is accompanied by infection. We conclude that repeated pulmonary infection can adversely affect protein-energy balance and that adequate nutritional support should be considered in management during and after each episode.

Adolescent↗

PubMed1984

Non-overlapping factor scales for the Mini-Mult.

Performed a principal axes factor analysis on Mini-Mult item data obtained from 249 medical and psychiatric patients. Six factors were extracted and after Varimax rotation were labeled Psychoticism, Alienation and Low Morale, Somatization, Shyness, Dysphoria, and Defensiveness. Corresponding to these factors, non-overlapping summative scales were constructed and their reliabilities evaluated. Alpha coefficients were satisfactory for three scales, but the remaining scales, which contained fewer items, had less adequate reliabilities. The scales were recommended for applications in which it is desirable to avoid the excessive item overlap of the standard Mini-Mult scales.

Community Mental Health Services↗