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Biomedical subjects

R Newton

Publications and source records attributed to R Newton.

At least 163 records · Page 9Linked to original sources
PubMed1983

Clinical findings in children with occipital spike-wave complexes suppressed by eye-opening.

We studied the EEG abnormality of occipital sharp and slow waves significantly or completely suppressed by eye-opening in 16 patients. All had seizures consisting of transient loss of consciousness. Most experienced additional grand mal, partial (simple or complex), or clonic fits. Response to treatment was poor initially in 9 and subsequently in 11. Learning difficulties were present in 10 children. The cases illustrate the wide range of clinical disorders that may accompany the EEG abnormality and indicate that the prognosis associated with this EEG pattern is not necessarily benign.

Child↗
PubMed1983

Testicular hormone concentration in men with varicoceles: immediate effects of varicocelectomy.

As part of an investigation of the role of gonadal steroid concentrations and testicular function, testosterone (T), estradiol (E2) and dehydroepiandrosterone sulfate (DHEA-S) were measured in bilateral testicular biopsies from infertile men with varicoceles. The biopsies were performed randomly either immediately before or 1 hour after varicocelectomy in an effort to detect acute changes in testicular hormone concentrations. No significant differences were noted between these two groups nor was there consistent evidence of disturbed in vivo Leydig cell function. A wide range of testicular hormone concentrations was found in these biopsies, which did not correlate well with morphologic findings. This suggests that many different pathophysiologic conditions may exist in association with the presence of a varicocele.

Biopsy↗
PubMed1981

Plasma and salivary pharmacokinetics of caffeine in man.

Plasma and salivary caffeine concentrations were measured by gas-liquid chromatography in 6 healthy caffeine-free volunteers following oral administration of 50, 300, 500 and 750 mg caffeine. Caffeine was also given to a single subject intravenously in doses of 300, 500 and 750 mg. Caffeine was rapidly absorbed and was completely available at all doses. The apparent first-order elimination rate constant decreased linearly with dose and was 0.163 +/- 0.081 h-1 for 50 mg and 0.098 +/- 0.027 h-1 for 750 mg. The total body clearance was unaffected by dose and was 0.98 +/- 0.38 ml/min/kg. There was a trend towards increasing apparent volume of distribution with increasing dose. A linear relationship existed between the area under the plasma concentration, time curve and dose and dose-normalised plasma concentration, time plots were superimposable. These findings suggest that caffeine obeys linear pharmacokinetics over the dose range investigated. Despite significant inter-individual differences in pharmacokinetic parameters there was good reproducibility within 5 subjects given 300 mg caffeine orally on 3 occasions. Salivary caffeine levels probably reflect the unbound plasma caffeine concentration and can be used to estimate the pharmacokinetic parameters of the drug. Overall the saliva/plasma concentration ratio was 0.74 +/- 0.08 but within subjects some time-dependence of the ratio was found with higher ratios initially (even after intravenous administration) and lower ratios at longer time intervals after the dose. Urinary elimination of caffeine was low and independent of dose: 1.83% of the dose was eliminated unchanged.

Adult↗
PubMed1981

A controlled study of trazodone, imipramine, and placebo in outpatients with endogenous depression.

A 4-wk double-blind controlled study of the antidepressant efficacy of the triazolopyridine derivative trazodone, in contrast to imipramine and placebo, was carried out in 30 endogenously depressed outpatients. Trazodone was found to be equivalent in efficacy to imipramine and statistically significantly superior to placebo. Trazodone showed a significant antidepressant effect relative to placebo when outcome was measured after only 7 days of treatment. This antidepressant effect was sustained for at least 5 mo as indicated by an open study phase following the double-bind study. Side effects, particularly anticholinergic properties, were significantly less apparent on trazodone compared to imipramine. A limited study of the relationship of trazodone plasma levels to therapeutic outcome revealed no simple linear relationship and represents a direction for future research.

Adult↗
PubMed1980

The effect of varicocelectomy on sperm count, motility, and conception rate.

One hundred and eighty-seven male partners of involuntarily infertile couples were evaluated and found to have dilatation of the left spermatic vein. One hundred and forty-nine underwent varicocelectomy and achieved a statistically significantly improved conception rate as compared with the nonoperated group. Although 70.5% of men whose wives subsequently conceived had improved semen count and motility postoperatively, no parameter distinguished these men from other patients with similar improvement who remained infertile.

Female↗
PubMed1980

Lack of anticholinergic side effects with a new antidepressent--trazodone.

An analysis was made of the occurrence of anticholinergic side effects in 15 multicenter studies of 379 patients with endogenous depression who received either trazodone, imipramine, or placebo. The incidence of 4 anticholinergic side effects was examined: dry mouth, blurred vision, bowel movement disturbance, and delayed urine flow. When the number of patients having each of the 4 symptoms was compared, there were no statistically significant differences in the incidence of side effects between the trazodone and placebo groups. However, comparisons between trazodone and imipramine indicated the incidence of side effects was significantly lower in the trazodone group.

Adult↗
PubMed1976

Serum luteinizing hormone, follicle-stimulating hormone, and testosterone responses to gonadotropin-releasing factor in males with varicoceles.

Five infertile males, ages 25 to 35, with oligospermia and varicocele had following gonadotropin-releasing hormone (LRF) infusion a rise of serum follicle-stimulating hormone, luteinizing hormone, and testosterone levels which was not different from that of normal fertile males. The response of these hormones to LRF infusion was unaltered by spermatic vein ligation, but a significant elevation of the sperm count occurred. Thus, improvement in sperm count following spermatic vein ligation is not mediated via changes in peripheral gonadotropin or testosterone concentrations.

Adult↗