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Biomedical subjects

S Rogers

Publications and source records attributed to S Rogers.

At least 235 records · Page 13Linked to original sources

Effect of uridine on hepatic galactose-1-phosphate uridyltransferase.

Uridine sugar nucleotides are important intermediates in galactose metabolism and may play a role in the long-term galactose toxicity in human galactose-1-phosphate uridyltransferase deficiency galactosemia. Since administration of uridine, a precursor of uridine nucleotides, has been considered as a therapeutic measure, we have investigated the effects of this compound on the activity of rat hepatic transferase. Uridine has been found to be an inhibitor of the enzyme in in vitro studies and to cause an increase in galactose-1-phosphate in liver perfused with galactose which is consistent with physiologic inhibition of the enzyme. Uridine is a partial linear competitive inhibitor of UDPglucose and an uncompetitive inhibitor of galactose-1-phosphate. These findings suggest caution should be applied in giving the compound to subjects with genetically limited transferase activity because of the possibility of inhibiting the small amount of residual enzyme.

Aging↗

The effects of intravenous clomipramine on neurohormones in normal subjects.

The neuroendocrine effects of iv administration of clomipramine (CMI), a serotonin reuptake inhibitor, were studied in normal subjects. Under double blind, placebo-controlled conditions, single 10- and 20-mg doses of CMI were administered. Ten milligrams of CMI led to significant increases in plasma PRL and cortisol concentrations; plasma ACTH increased slightly but not significantly. In contrast, plasma GH, melatonin, and norepinephrine concentrations did not increase. Plasma PRL, ACTH, and cortisol levels increased significantly after 20 mg CMI; again, there were no significant changes in plasma GH, melatonin, or norepinephrine concentrations. All subjects tolerated the 10-mg dose well, but the 20-mg dose caused nausea in three of six subjects. Desmethylclomipramine, a metabolite that inhibits reuptake of norepinephrine, was not detectable in plasma after either CMI dose. These results support the hypothesis that serotonin is involved in the regulation of PRL, cortisol, and ACTH in humans.

Adrenocorticotropic Hormone↗

Risk factors for neuropsychological impairment in alcoholics: antisocial personality, age, years of drinking and gender.

One hundred eighty-two alcoholics were studied using subtests from the Halstead-Reitan Neuropsychological Battery, Wechsler Adult Intelligence Scale and the Wechsler Memory Scale. Alcoholics who displayed antisocial personality disorder (ASPD) were more impaired on the Brain Age Quotient, a summary measure of neuropsychological impairment. Multivariate analyses indicated that presence of ASPD contributed significantly to this impairment, independent of age, length of drinking history or gender. Discriminant analysis using these variables as predictors allowed for clinically useful levels of prediction of neuropsychological impairment in individual subjects.

Adult↗

Merging nursing research and practice: a case of multiple identities.

Although using research to guide nursing practice has been a long-standing goal for the nursing discipline, the actual merger of research and practice is not yet widespread. There are many possible explanations for the limited progress that has been made in this arena. In this paper, it is suggested that the multiple identities taken on by nurses may stifle actualizing a merger between research and practice. Diverging responsibilities and orientations among identities are depicted by considering the nurse as researcher, clinician, educator and administrator. In addition to elucidating differences among these various nurse identities, the paper addresses their commonalities, the most obvious and important of which is that of nurse. If individuals retain the identity of nurse as the generic and salient characteristic, the multiple nurse identities have the potential to become a complementary array of diverse resources that can empower rather than thwart merging research and practice.

Humans↗

Field evaluation of the Copal UA-231 automatic sphygmomanometer.

Automated sphygmomanometers should be evaluated in field studies before being recommended for epidemiological use. In this study an automated sphygmomanometer, the Copal UA-231, was evaluated on the basis of duplicate blood pressure measurements, one with this machine and one with a Hawksley random zero machine, taken on 1536 participants in a health survey. The Copal-random zero differences had a mean of 2.3 mm Hg for systolic blood pressure and 1.9 mm Hg for diastolic pressure, the Copal reading higher than the random zero. The standard deviations of these differences were similar to the standard deviations of the differences between two random zero measurements taken on subjects in a separate survey. However, Copal-random zero differences varied systemically with blood pressure levels. In this study a 10 mm Hg increase in systolic blood pressure was associated with a 1.22 mm Hg increase in the Copal-random zero difference and a 10 mm Hg increase in diastolic blood pressure was associated with a 1.15 mm Hg increase in the Copal-random zero difference. The Copal UA-231 is recommended for use in field surveys, but it should be recognised that a small systematic increase in Copal-random zero difference with increasing blood pressure may complicate interpretation of epidemiological associations.

Adolescent↗

Organisation of community nursing services.

The Cumberlege Report proposal for a neighbourhood nursing service is attractive, but does it need more nurse managers? Sheila Rogers and Lex Barr argue that it does not.

Administrative Personnel↗

Nutritional determinants of haemostatic factors in the Caerphilly Study.

A study of possible nutritional determinants of certain haemostatic factors (heparin-neutralizing activity, fibrinogen and antithrombin III) was conducted in the Caerphilly cohort of 2512 men. Data on diet were obtained in a sub-sample of 665 men by a 7-d weighed dietary inventory and in the complete cohort by questionnaire. All the associations between major nutrients and haemostatic factors were weak and few achieved statistical significance. There were significant associations between two of the blood tests and total energy intake which suggests that, in general, relationships between nutritional variables and thrombosis-related factors should be standardized for total energy intake. Negative associations between alcohol, fibrinogen and antithrombin III and positive associations between fibre, polyunsaturated fat and antithrombin III are of possible clinical or public health importance. However, nutritional factors appear to explain only about 3 per cent of the variance in the distributions of the haemostatic factors examined. The extent to which uncertainties in the measurement of dietary intake will have led to the underestimate of the true association is, of course, unknown. At the same time it is of relevance that in similar studies of dietary determinants of plasma cholesterol only about 3 per cent of the variance of cholesterol levels can be explained.

Antithrombin III↗

Neuroendocrine response to 5-hydroxytryptophan in seasonal affective disorder.

A double-blind random-ordered comparison of the effects of placebo and 5-hydroxytryptophan (200 mg, orally) in ten depressed patients with seasonal affective disorder (SAD) and ten controls disclosed slightly but significantly higher basal levels of serum prolactin and a trend toward higher basal levels of serum cortisol in the patients with SAD compared with controls. After administration of 5-HTP, the cortisol level significantly increased and the prolactin level significantly decreased in both patients and controls. No differences in the melatonin level, growth hormone level, blood pressure, or pulse rate and no side effects were noted between patients and controls in the two study conditions; the timing of basal and 5-hydroxytryptophan-stimulated hormonal secretions was similar for both groups. These results are discussed with reference to current hypotheses of the cause of SAD.

5-Hydroxytryptophan↗

Comparative pharmacokinetics of levonorgestrel and ethinyloestradiol following intravenous, oral and vaginal administration.

The plasma concentrations of levonorgestrel (LNG) and ethinyloestradiol (EE2) have been measured in a random crossover study in five healthy female volunteers given a combination oral contraceptive tablet (250 micrograms LNG and 50 micrograms EE2) by the oral route and per vaginum and also receiving the same dose intravenously. The fractional bioavailability of LNG after oral administration was 1.00 +/- 0.16 (mean +/- S.D.) and after vaginal insertion 0.88 +/- 0.16. The time to peak (tmax) was significantly longer and the peak concentration (Cmax) significantly reduced following vaginal administration. The fractional bioavailability of EE2 after oral dosing was 0.62 +/- 0.11 and after vaginal insertion 0.74 +/- 0.16; tmax was prolonged, hence absorption was slower from the vagina. The reduced rate of absorption was evident in the differences seen in the area under the curve for early time periods for both steroids. However, overall bioavailability is not reduced for either steroid when a single tablet is inserted into the vagina.

Administration, Intravaginal↗

Effects of a fish oil supplement on serum lipids, blood pressure, bleeding time, haemostatic and rheological variables. A double blind randomised controlled trial in healthy volunteers.

Sixty male volunteers were randomised to take 10-16 ml of a fish oil supplement (MaxEPA) or 10-16 ml of olive oil for a period of 3-6 weeks. A fall in serum triglyceride of 54% (P less than 0.01) and a fall in diastolic blood pressure of 7% (P less than 0.05) was attributable to taking fish oil supplements. The bleeding time was prolonged by 12%, but this did not reach conventional levels of statistical significance. A global test of heparin-neutralising activity, the heparin thrombin clotting time, increased by 14% (P = 0.05) but there was no demonstrable effect on thrombin time, fibrinogen or (intraplatelet) platelet factor 4. A fall in red cell pore transit time of 23% was attributable to fish oil, but was not statistically significant. There was no convincing evidence of an effect of fish oil supplementation on total serum cholesterol, HDL-cholesterol, blood counts or platelet aggregation. A beneficial effect of fish oil on the cardiovascular risk profile was confirmed in this study. However, with this regime changes in total cholesterol, HDL-cholesterol and platelet aggregation are of unlikely clinical importance.

Adult↗

Word recognition and comprehension skills in hyperlexic children.

Five hyperlexic boys (4-5 to 10-1 years), who had been diagnosed with infantile autism or pervasive developmental delay in early childhood, were evaluated. Measures of intelligence, single-word recognition and comprehension, and picture naming were administered to determine the precocity or deficiency of reading recognition and comprehension, the underlying mechanisms of oral reading, and possible parallels with the acquired dyslexia subtypes. The results indicated that hyperlexia may be operationalized as unexpected reading precocity as compared to IQ; however, reading comprehension was not unexpectedly deficient. The phonological route to reading appeared to be preferred to the lexical route, and the overall pattern of performance most closely paralleled that of the surface dyslexic subtype.

Autistic Disorder↗

Microinjection of ubiquitin: changes in protein degradation in HeLa cells subjected to heat-shock.

Ubiquitin was radiolabeled by reaction with 125I-Bolton-Hunter reagent and introduced into HeLa cells using erythrocyte-mediated microinjection. The injected cells were then incubated at 45 degrees C for 5 min (reversible heat-shock) or for 30 min (lethal heat-shock). After either treatment, there were dramatic changes in the levels of ubiquitin conjugates. Under normal culture conditions, approximately 10% of the injected ubiquitin is linked to histones, 40% is found in conjugates with molecular weights greater than 25,000, and the rest is unconjugated. After heat-shock, the free ubiquitin pool and the level of histone-ubiquitin conjugates decreased rapidly, and high molecular weight conjugates predominated. Formation of large conjugates did not require protein synthesis; when analyzed by two-dimensional electrophoresis, the major conjugates did not co-migrate with heat-shock proteins before or after thermal stress. Concomitant with the loss of free ubiquitin, the degradation of endogenous proteins, injected hemoglobin, BSA, and ubiquitin was reduced in heat-shocked HeLa cells. After reversible heat-shock, the decrease in proteolysis was small, and both the rate of proteolysis and the size of the free ubiquitin pool returned to control levels upon incubation at 37 degrees C. In contrast, neither proteolysis nor free ubiquitin pools returned to control levels after lethal heat-shock. However, lethally heat-shocked cells degraded denatured hemoglobin more rapidly than native hemoglobin and ubiquitin-globin conjugates formed within them. Therefore, stabilization of proteins after heat-shock cannot be due to the loss of ubiquitin conjugation or inability to degrade proteins that form conjugates with ubiquitin.

Autoradiography↗