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Biomedical subjects

R L Young

Publications and source records attributed to R L Young.

At least 19 recordsLinked to original sources
PubMed1992

A randomized, double-blind, placebo-controlled comparison of the impact of low-dose and triphasic oral contraceptives on follicular development.

OBJECTIVE: This investigation tests the hypothesis that triphasic oral contraceptives are associated with the development of large, persistent ovarian cysts. STUDY DESIGN: Weekly vaginal ultrasonography was used in a randomized, double-blind, placebo-controlled, parallel-group, single-center study that compared the incidence, risk, size, and time to resolution of ovarian follicles in healthy women who took Estrostep or Loestrin oral contraceptives (manufactured by Parke-Davis) or a placebo during three consecutive menstrual cycles. RESULTS: Sixty-three percent of placebo-treated subjects developed follicles greater than 18 mm, compared with 39% and 23% in the Estrostep and Loestrin groups. The risks for each group of developing a large follicle during a single cycle were not different. No dominant follicle persisted for greater than 2 weeks for any subject. CONCLUSION: These results demonstrate that follicular development continues during treatment with oral contraceptives. In addition, the findings fail to support the hypothesis that triphasic oral contraceptives result in persistent ovarian cysts.

Adult↗
PubMed1992

Calcitonin gene-related peptide: mechanisms of modulation of antral endocrine cells and cholinergic neurons.

Actions of human calcitonin-gene related peptide (hCGRP) on acetylcholine (ACh) discharge and gastrin and somatostatin release from rat antral mucosal-submucosal fragments were examined in both dynamic perifusion experiments and short-term static incubation studies. The principal findings of the dynamic perifusion experiments were that hCGRP exerted a dual or biphasic effect on ACh discharge and gastrin release. Initial exposure of antral tissues to hCGRP (1 x 10(-8) M) resulted in stimulation of both ACh and gastrin release that was of brief duration. Continued hCGRP perifusion caused subsequent inhibition of ACh and gastrin release that was substantially greater in duration and magnitude than the initial stimulatory responses. Static incubation studies indicated that hCGRP (10(-10) to 10(-7) M) stimulated somatostatin and inhibited gastrin release in a dose-dependent manner. Inhibition of gastrin and ACh release by hCGRP appeared to be an indirect effect that was mediated by somatostatin as suggested by studies with pertussis toxin (200 ng/ml). Furthermore, studies with atropine (1 x 10(-6) M) and tetrodotoxin (1 x 10(-6) M) indicated that CGRP-induced stimulation of somatostatin release and inhibition of ACh discharge occurred independent of muscarinic receptor activation and nerve excitation. In conclusion, results of these studies indicate that CGRP is capable of exerting both stimulatory and inhibitory effects on ACh release from mucosal-submucosal neurons and gastrin release from antral mucosal G cells in in vitro studies. These data suggest that the inhibitory effects of CGRP on cholinergic discharge and gastrin release are due to the paracrine effects of somatostatin released from antral D cells by direct action of CGRP.

Acetylcholine↗
PubMed1992

Selected aspects of polycystic ovarian disease.

Although there is general agreement about the polycystic ovary as an anatomic entity, a classic description of an associated syndrome remains elusive. This lack of definition, however, has not impeded clinical investigation. This article focuses on the diagnosis, pathogenesis, hypotheses, and treatment of polycystic ovarian disease.

Adrenal Cortex Hormones↗
PubMed1979

The treatment of benign thyroid disease.

The treatment of benign forms of thyroid disease is reviewed. Endemic goiter is a public health problem preventable by the addition of iodine to the food or water supply. Endemic and familial goiters are treated with replacement doses of I-thyroxine, as are sporadic colloid goiters and goiters resulting from chronic thyroiditis. Hyperfunctioning autionomous nodules without thyrotoxicosis and cystic nodules require no specific therapy. Prophylaxis against diffuse or nodular goiter after radiation to the head or neck for therapeutic purposes with thyroxine replacement therapy is debatable. All forms of hypothyroidism, including incipient types, require replacement thyroxine therapy, but this should be undertaken cautiously in older patients and in those with evidence of ischemic myocardial disease. Myxedema coma requires vigorous treatment and detailed supervision because of dismal mortality rates. Iodine 131 is the treatment of choice in diffuse toxic goiter, but alternative forms.

Adolescent↗
PubMed1979

Alcohol-induced Cushingoid syndrome.

A 35-year-old woman with alcoholic liver disease presented with physical stigmas and laboratory confirmation of Cushing's syndrome. With discontinuance of alcohol, her signs of Cushing's syndrome resolved and the urinary free cortisol and the urinary 17-hydroxycorticosteroid response to dexamethasone returned to normal. These findings broaden the spectrum of deranged glucocorticoid chemistry that can occur in alcohol-induced cushingoid syndrome.

Adult↗
PubMed1979

Glucose-insulin response to oral glucose in a healthy obese population.

The characteristics of the glucose and insulin responses during the glucose tolerance test (GTT) in obese people as a group have not been established. We analyzed glucose and insulin levels during GTT in 160 healthy obese patients who averaged 42% over ideal body weight. Statistical upper limit of normal for 2-h glucose was 260 mg/dl in women and 206 mg/dl in men. Although there was a significant correlation between insulin and glucose levels in both sexes and between insulin and degree of obesity in women, r values were relatively low (r less than 0.4 for all). High insulin levels and delayed peak insulin were present in the majority of patients with normal GTT and absent in many of the most obese patients. Results indicate that upper limits of normal glucose for GTT in the obese are much higher than currently accepted criteria.

Adult↗
PubMed1978

Treatment of genital herpes simplex virus infection with photodynamic inactivation.

A double-blind randomized study to evaluate the effect of proflavine in the treatment of genital herpesvirus infection was conducted. One hundred fifty-seven women were studied, of whom 75 were treated with proflavine (treated women) and 82 were treated with placebo (control group). There were 62 women with primary disease and 95 with recurrent infection. Under the conditions by which this study was conducted, there was no apparent difference in the time of healing of lesions, development of recurrences, or virus isolation following treatment in the proflavine-treated and control groups.

Acridines↗
PubMed1978

Delayed cure of Cushing's disease after transsphenoidal surgery of pituitary microadenomas. Report of two cases.

Transsphenoidal microdissection has been proposed as a preferred means of treating Cushing's disease. This procedure allows the surgeon to remove a pituitary microadenoma and at the same time to preserve normal tissue. Two cases described here were treated by this method. An interesting and important observation was that neither patient appeared to be cured for 2 to 6 weeks after surgery, as assessed by dexamethasone suppression. Later, normal suppressibility occurred and the course of each patient was compatible with cure. Patients treated by this method should not be automatically retreated because of adrenocorticotropic hormone (ACTH) non-suppressibility in the early postoperative period.

Adenoma, Chromophobe↗
PubMed1978

T4-thyrotoxicosis.

A 41-year-old man had thyrotoxicosis, diffuse goiter, exophthalmos, high titer of antithyroglobulin antibodies but undetectable long-acting thyroid stimulator. Initially, he had both elevated serum thyroxine (T4) and reverse triiodothyronine (rT3) levels, but normal serum triiodothyronine (T3) and free triiodothyronine (FT3) levels and 24-hour radioactive iodine uptake. Observations prior to radioactive iodine therapy uptake. Observations prior to radioactive iodine therapy showed a persistently normal T3 level in spite of development of atrial fibrillation. Iodine excess was not present, nor were any drugs or systemic illnesses that cause preferential monodeiodination of T4 to rT3 instead of T3. The data support the concept that (1) thyroxine is not just a prohormone for triiodothyronine but is metabolically active itself; (2) Graves' disease can be a cause of T4-thyrotoxicosis. We conclude that a normal serum T3 level does not rule out thyrotoxicosis.

Adult↗
PubMed1978

The increasing incidence of hypothyroidism within one year after radioiodine therapy for toxic diffuse goiter.

Patients treated with 10 mCi of I-131 for toxic diffuse goiter in the period January 1974--June 1976 were evaluated for development of hypothyroidism. Fifty percent were hypothyroid within 3 mo and 69% within 1 yr of treatment. Our data suggest that there is a higher incidence of hypothyroidism after standard doses of I-131 in the 1970s as contrasted with treatment groups in the 1950s and 1960s. The pathophysiology of this increased incidence is not known with certainty; however, infrequent use of thionamide medication, together with recent increases in dietary iodine, may render the gland more radiosensitive.

Adolescent↗
PubMed1977

Radioimmunoassay of the anticonvulsant agent clonazepam.

A simple and specific radioimmunoassay was developed for the determination of the anticonvulsant agent clonazepam directly in plasma without extraction. Antibodies to clonazepam were produced in rabbits after immunization with an immunogen prepared by covalently linking the 3-hemisuccinyloxy derivative of clonazepam to bovine serum albumin. When employing 3H-clonazepam as the tracer, the radioimmunoassay has a limit of sensitivity of 5 ng/ml using a 0.1-ml sample of plasma. The antibodies exhibited a high degree of specificity for clonazepam; no cross-reactivity was observed with its 7-amino and 7-acetylamino metabolites nor with a number of other widely prescribed anticonvulsant agents that might be administered in conjuction with clonazepam. Satisfactory agreement was obtained for the plasma levels of clonazepam in humans when samples were assayed by the radioimmunoassay and an established electron-capture GC technique. By virtue ot its simplicity, the radioimmunoassay offers a distinct advantage to the clinician for monitoring plasma clonazepam levels and the compliance of patients undergoing anticonvulsant therapy with the drug.

Animals↗
PubMed1977

Painless thyroiditis and transient hyperthyroidism without goiter.

Eight women had painless thyroiditis, transient thyrotoxicosis, and low radioactive iodine uptakes but were without goiter; they constituted 15% of all thyrotoxicosis cases that we saw during the past year. Standard antithyroid antibody tests by tanned erythrocyte hemagglutination, complement fixation, and colloid and microsomal fluorescence, if present initally, were only weakly psotivie and became negative by 9 months. However, human antithyroglobulin antibody levels by a sensitive radioimmunoassay were elevated initially in all patients. In general, these radioimmunoassayable antibody levels fell, but they had not returned to normal by 9 months. Serial thyroid function tests and standard antithyroid antibody tests were most compatible with subactue thyroidtis. However, the persistence of radioimmunoassayable antithyroblobulin antibodies and recent reports of histologic evidence of lymphocyte thyroiditis in similar patients with goiter leaves open the possibility that this is a previously unrecognized presentation of chronic lymphocytic thyroiditis. Neither the cause nor the ultimate course of this syndrome is known.

Adult↗