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Biomedical subjects

L C Ward

Publications and source records attributed to L C Ward.

At least 127 records · Page 7Linked to original sources
PubMed1984

The utility of an improved readability short form of the MMPI with elderly male patients.

Compared an improved readability short form of the MMPI (IRF) with the FAM and the MMPI-168 in a sample of 100 male veterans, aged 60 and over. The three forms were found to perform acceptably well in terms of measures commonly used to evaluate the statistical validity of MMPI short forms. Median correlations of short form estimates with the MMPI standard scales were .91, .90, and .89 for the FAM, MMPI-168, and the IRF, respectively. In comparison with the other two forms, the IRF was intermediate in the frequency of codetype matches, but was highest in rate of correct validity decisions. The IRF also showed the fewest significant differences between the means of the estimated MMPI scale scores and those that actually were obtained. It was concluded that although the results demonstrated no strong statistical advantage for any short form, the IRF, because of increased comprehensibility, might have a wider applicability, particularly among patients with whom short forms would be used most often.

Aged↗
PubMed1984

Protein synthesis in isolated perfused rat skeletal muscle. Contribution of intra- and extracellular amino acid pools.

Protein synthesis was measured in perfused rat skeletal muscle using [14C]lysine in the presence of increasing amounts of lysine in the perfusate. The results obtained clearly indicated that both the extracellular and intracellular pools of amino acids act as direct precursors for protein synthesis and analysis of the data, according to O'Hara et al. (J. molec. cell. Cardiol. 13, 925-940, 1981) further indicated that extracellular sources of lysine supplied 64 and 81% of the lysine incorporated in the absence and presence of insulin, respectively. The rate of protein synthesis were assessed to be 0.22 mumol lysine incorporated g-1 muscle per 3 hr of perfusion increasing to 1.0 mumol g-1 3 hr-1 in the presence of insulin.

Amino Acids↗
PubMed1984

A radiochemical method for determination of ethanol oxidation.

A radiochemical method for the measurement of ethanol oxidation by tissue preparations is described. Ethanol oxidation is determined from the production of [14C]acetaldehyde, quantified as the semicarbazone derivative, from [1-14C]ethanol. The assay is quantitative, reproducible and highly correlated with the NADH-enzymic-spectrophotometric procedure.

Animals↗
PubMed1983

Protein synthesis in the early stages of cardiac hypertrophy.

Cardiac hypertrophy, induced in rats by either tri-iodothyronine or isoproterenol, administered daily for 7 days, was monitored using several parameters. Both treatments increased RNA concentrations 24 hr after the first injection, while heart weight increased following 2 injections to 46% above control after 7 days. Cardiac protein synthetic activity, as determined by the rate of peptidyl-puromycin formation, was increased by both tri-iodothyronine and isoproterenol 24 hr after a single injection, implying an increase in the number of functional ribosomes. RNA activity (the rate of peptidyl-puromycin formation per unit RNA) remained constant, suggesting that neither accelerated rates of initiation or translation nor increased activation of pre-existing, non-translating ribosomes was involved in the observed increase in protein synthetic activity. In contrast, constant infusion of [14C] tyrosine indicated no change in protein synthetic rate 24 hr after a single tri-iodothyronine injection and decreased protein synthetic rate after isoproterenol injection. It is concluded that the use of [3H]puromycin to estimate protein synthetic activity may be a more sensitive procedure for detecting early changes in protein synthesis in cardiac hypertrophy than constant isotope infusion, owing to the problems associated with determining the precise precursor pool for protein synthesis in this latter method.

Animals↗
PubMed1983

Changes in body composition and muscle protein degradation during nutritional supplementation in nutritionally growth-retarded children with cystic fibrosis.

Changes in body composition and muscle protein degradation were studied in seven nutritionally growth-retarded children with cystic fibrosis (CF) before and after nutritional supplementation and in eight healthy children who served as controls. Supplemental feedings consisted of a peptide formula that increased dietary protein and energy intakes approximately 20-40% over a 6-month period, delivered either as oral supplement or overnight intragastric feeding. Body composition was assessed by anthropometric data and measurements of whole body potassium (40K) and creatinine excretion. Muscle protein degradation was measured by urinary 3-methylhistidine excretion, an index of myofibrillar protein catabolism. Compared with controls, CF children had significantly reduced body mass, body fat, and muscle mass, and a significantly increased rate of myofibrillar protein degradation. With nutritional supplementation, significant catch-up weight gain and improved linear growth were observed with evidence of accretion of lean body mass and muscle mass, and in all but one severely malnourished patient with progressive disease, there was normalization of the high rate of muscle protein degradation. Thus, this form of nutritional therapy has significant benefits in terms of body protein accretion and myofibrillar protein degradation.

Adolescent↗
PubMed1983

Prediction of Wiggins content scale scores from 168- and 399-item abbreviations of the MMPI.

Multiple regression equations for estimating Wiggins content scores from 399- and 168-item abbreviations of Form R of the Minnesota Multiphasic Personality Inventory (MMPI) were derived for 100 patients and cross-validated in a separate sample of 50 patients. Across samples, Rs between 399-item short form scales and corresponding full scales were very high (median = .98 for the total sample), and the equations predicted accurately in cross-validation. Rs in estimating from 168 items were lower (median = .91 for the total sample), but the equations estimated mean content scores well in cross-validation. These results were viewed as indicating that there may be little loss in estimating from 399 items but that error in prediction may be unacceptably high for some of the 168-item short form scales. The correspondence of Wiggins scales and standard MMPI scales was also studied through regression analyses, and it was concluded that, although there is considerably overlap in the two sets of scales, inferences as to self-report content from the standard scales are not always simple or especially accurate.

Adult↗
PubMed1982

Amino acid supply and protein metabolism in isolated perfused rat skeletal muscle.

The uptake of amino acids by the perfused rat hind-limb at increasing perfusate amino acid concentrations was studied both in the presence and absence of insulin. The uptake of the essential amino acids could be correlated with their concentrations in muscle protein. A net protein synthetic rate was calculated from the predicted incorporation of phenylalanine and was 33 nmol h-1g-1, a value in good agreement with those obtained in other studies. The possible significance of the supply of leucine in the regulation of muscle protein synthesis is considered.

Amino Acids↗
PubMed1982

Pseudoseizures: diagnostic evaluation.

A prospective study of pseudoseizures using prolonged video-electroencephalographic (EEG) recording was carried out in 60 patients. Of 33 patients with episodes of uncertain mechanism, a diagnosis based on recorded episodes was made in 18 (55%). Twelve (36%) had pseudoseizures; 6 (18%) had epileptic seizures. Ten additional patients had epileptiform EEGs compatible with epilepsy. Of 27 patients with presumably uncontrolled epileptic seizures, 4 (15%) had recorded pseudoseizures. Prediction of the nature of the episode by the admitting neurologist was accurate in 67% of cases. Determination from observations of unit personnel and neurologists was correct in less than 80% of episodes. These data suggest that pseudoseizures occur frequently in patients being evaluated for epilepsy or suspected epilepsy. The clinical differentiation between epileptic seizures and pseudoseizures is often inaccurate. This differentiation is facilitated by prolonged video-EEG recording.

Adolescent↗
PubMed1982

Effect of height on nerve conduction velocity.

The effect of height on nerve conduction velocity (NCV) was studied in 41 normal subjects. Peroneal and sural NCV correlated inversely with height and with estimated axonal length, whereas median motor and sensory NCV failed to show any significant relationship to height. These findings are consistent with the hypothesis of abrupt distal axonal tapering in the lower extremities. Recognition of height effect in the legs is clinically significant, since diagnostic sensitivity of NCV determinations is improved when corrected for height differences. Multiple regression equations derived from the sample data allow satisfactory estimation of peroneal NCV, sural NCV, H-reflex latency, and F-wave latency from height (or axonal length), age, and other important predictors.

Adult↗
PubMed1981

Comparison of hemagglutination inhibition test and enzyme-linked immunosorbent assay for determining antibody to rubella virus.

The hemagglutination inhibition test (HAI) and the enzyme-linked immunosorbent assay (ELISA) for detecting antibody to rubella virus were compared by testing 25 sets of paired sera taken before and after infection and 10 sets of sera taken during acute and convalescent stages of the disease and by screening 700 serum samples from the Collaborative Perinatal Project, NIH/NINCDS. The tests were found to be comparable in their ability to detect positive and negative sera, rises in titers, and seroconversions. When a purified antigen and carefully prepared reagents were used, ELISA was found to be as accurate and reliable as HAI. ELISA required no pretreatment of serum, could easily be automated, and was less time-consuming than HAI.

Antibodies, Viral↗
PubMed1981

Peripheral neuropathy in epileptic patients.

The prevalence of peripheral neuropathy in 186 epileptic patients was 16.7%. The neuropathy was characterized by stocking hypesthesia and reduced Achilles reflexes, and it occurred with all anticonvulsant agents. Electrophysiologic tests indicated slowing of peroneal and sural nerve conduction velocity and prolongation or absence of H reflexes and F responses. The prevalence of neuropathy was not greater in patients receiving phenytoin, and there was no relationship between clinical or electrical abnormalities and blood levels or duration of treatment for either phenytoin or phenobarbital. We did not find a specific relationship between phenytoin usage and peripheral neuropathy in epileptic patients.

Epilepsy↗
PubMed1980

Dietary protein intake and 3-methylhistidine excretion in the rat.

1. Rats were fed for 14 d on diets containing 50, 150 or 250 g/kg casein as the protein source. The daily excretion of Nt-methylhistidine (His(tau Me)), a non-re-utilized amino acid, was determined. 2. His(tau Me) excretion/100 g body-weight appeared to be unaffected by increasing the concentration of dietary protein from 150 to 250 g/kg. Assuming no change in the proportion of muscle in the animals these results are indicative of no change in myofibrillar protein catabolic rate. The excretion rate/100 g body-weight of the animal given 50 g/kg casein was lower than the other two treatments, especially towards the end of the 14 d treatment period. Thus at this time the myofibrillar protein catabolic rate was lower than in the animals fed on the higher protein diet. 3. In the animals fed on the high protein diet there was a tendency for this (tau Me) excretion rate/100 g body-weight to increase with age. 4. Nitrogen balance and creatinine excretion results are also presented.

Animals↗
PubMed1980

Conversion equations for modified scoring of the MMPI-168.

For a sample of 300 patients who had been administered the Minnesota Multiphasic Personality Inventory (MMPI), the MMPI-168 was extracted from the full MMPI and scored to incorporate those items normally excluded by Form R keys. MMPI-168 correlations with the full MMPI ranged from .80 to .97 with a mean of .90, indicating satisfactory statistical validity, and modified scoring was shown to improve predictability for Pa and Sc. Using these data, substitution equations for transforming MMPI-168 raw scores to estimates of full-scale scores were calculated. These transformations did not differ greatly from those reported in previous research except on Pa and Sc, where additional items increase scale length substantially.

Journal Article↗
PubMed1979

The kinetics of myofibrillar protein breakdown in perfused rat skeletal muscle.

Nt-Methylhistidine, a non-reutilised amino acid present in some myofibrillar proteins, was radioactively labelled in vivo with [Me-3H]methionine. The specific radioactivities of protein-bound methylhistidine and free methylhistidine in perfusate after perfusion of rat hind limbs taken from prelabelled rats was determined. The decrease in urinary methylhistidine activity with time was determined for rats similarly labelled. Comparison of the specific activities of free and bound methylhistidine and the non-linear semilogarithmic plot of urinary methylhistidine activity suggest that the myofibrillar protein catabolism, as indicated by methylhistidine release, may not be a simple exponential process. The possibility of non-random decay is discussed and an alternative model proposed.

Animals↗