PubMed Health⌕ Search

Biomedical subjects

T H Hsu

Publications and source records attributed to T H Hsu.

At least 55 records · Page 3Linked to original sources
PubMed1993

Silica stone--development due to long time oral trisilicate intake.

We report a case of a 30-year-old female who had a long-term history of trisilicate-containing antacid intake for gastric discomfort. She had experienced repeated attacks of renal colic. Neither intravenous pyelography nor ureteroscopy could define the presence of calculi. The metabolic evaluations were normal. However, X-ray diffraction revealed a silicate stone. We suggest that the attack of renal colic in those patients with long-term history of trisilicate intake should arouse the possibility of silica urolithiasis.

Administration, Oral↗
PubMed1992

Comparisons of different animal skins with human skin in drug percutaneous penetration studies.

The in vitro penetration of theophylline, sodium diclofenac and benzoic acid through artificial cellulose membrane and eight animal skins was investigated. The intact animal skins including stratum corneum (SC) and viable epidermis were taken from frog, snake with or without scales, nude mice, Sprague-Dawley rat, porcine and human prepuce and thigh skin. The results indicated that the penetration was fastest through cellulose membrane and frog skin and slowest through human prepuce and thigh skin. The snake skin with scales slowed down the penetration rate more significantly than the scaled skin. Benzoic acid was the fastest penetrant through all animal skins. The permeable behaviors of sodium diclofenac through SC and intact skin of snake, porcine and human were compared. In porcine, sodium diclofenac penetrated through SC at a rate 33 times higher than through intact skin, but in snake and human skin, the rate through SC was only 2.2 and 1.6 times higher than through intact ones. This implies that both viable epidermis and SC were the major rate limiting barriers in drug penetration. DSC thermograms and IR spectra showed that the SC of snake, porcine and human thigh were very similar in structure and components. The study suggests that snake skin, porcine skin and human prepuce skin could replace the human skin in in vitro drug penetration experiments.

Animals↗
PubMed1990

[Application and environmental impact of the biocontrol agent--Bacillus thuringiensis subsp. israelensis for vector control].

In 1976, Goldberg and Margalit found a potent isolate of Bacillus thuringiensis subsp. israelensis, which has great mosquitocidal activity and was commercialized within 5 years in the USA. It is now the only bio-control agent on the market for vector control worldwide. Because of concerns about environmental pollution and ecological preservation, vector control can no longer be solely dependent on the use of chemicals. It appears that the best strategy is to be integrated with biological control. When considering the value and future progress of BTI, it is important to evaluate applicability based on (1) production technology and economic considerations (2) standardization and quality control, and (3) field realization and environmental impacts. Finally, government policy and regulation limitations are the key factors which influence the availability of BTI in the vector control program.

Animals↗
PubMed1983

Hormonal responses to acute volume changes in anephric subjects.

The response of plasma aldosterone and cortisol concentrations to acute volume depletion was studied in 18 chronically anephric subjects and four recently nephrectomized subjects. Volume-depleting hemodialysis and hemodialysis without volume depletion produced insignificant changes in plasma aldosterone concentrations in chronically anephric subjects. Failure of volume depletion to increase plasma aldosterone concentrations in these subjects could not be attributed to reductions in plasma potassium concentrations and was in marked contrast to the effect on plasma cortisol concentrations, which increased significantly during volume depletion. Changes in plasma cortisol concentrations exhibited a negative correlation with changes in diastolic blood pressure (r = -0.712, P less than 0.001) and were shown to correspond to similar changes in plasma ACTH concentrations. Comparable increases in plasma cortisol and ACTH concentrations were also demonstrated in the studies on recently nephrectomized subjects, who, in contrast to chronically anephric subjects, exhibited increases in plasma aldosterone concentrations which were concordant with the changes in plasma cortisol and ACTH concentrations. These findings suggest that plasma aldosterone concentrations are regulated by a volume-sensitive mechanism in recently nephrectomized subjects but not in chronically anephric subjects. We interpret these data as evidence of aldosterone responsiveness to ACTH that persists for a limited time only after removal of the stimulus provided by the renin-angiotensin system. Volume-related changes in plasma cortisol and ACTH concentrations occur in the absence of stimulation by a functioning renin-angiotensin system.

Adolescent↗
PubMed1983

Clinical assessment of a radioimmunoassay for free thyroxine using a modified tracer.

A radioimmunoassay for measuring free thyroxine in plasma was introduced by Amersham using a I-125-labeled T4 derivative that does not bind significantly to the thyroxine-binding proteins. We evaluated this RIA for its clinical utility in assessing 278 patients with thyroid and nonthyroidal diseases. The precision of the Amerlex free T4 assay, expressed as coefficient of variation, was 20% at 0.16 ng/dl, 6.9% at 0.55 ng/dl, 4.2% at 1.08 ng/dl, 5.3% at 2.29 ng/dl, and 6.3% at 3.18 ng/dl. A reference range for free T4 was established as 0.68-1.8 ng/dl, n = 171. The correlation coefficients (r) of a dialysis method and a free thyroxine index were 0.871 and 0.911, respectively. Free T4 correctly classified 98% euthyroid, 92% hypothyroid, 100% hyperthyroid, 100% euthyroid with elevated TBG, and 87% of phenytoin patients. In addition, 80 patients with acute nonthyroidal illness were studied. Most of these patients have normal to low free T4, very low T3, and elevated rT3. We found this free T4 assay to be precise, easy to perform, and reliable in classifying thyroid status in most patients.

Evaluation Studies as Topic↗
PubMed1982

Frequency of abnormalities of cortisol secretion and water metabolism in patients with small cell carcinoma of the lung and other malignancies.

Previous studies have suggested that ectopic production of adrenocorticotropic hormone (ACTH) or antidiuretic hormone (ADH) may occur commonly in patients with small cell carcinoma of the lung (SCCL) and that evidence of such production may be elicited only by provocative tests of water excretion and adrenal function. We studied 28 patients with SCCL and 29 patients with other cancers. Adrenal function, assessed by measuring the 8 am plasma cortisol, the 8 am to 4 pm diurnal variation in plasma cortisol, and the suppressibility of the 8 am plasma cortisol following administration of 1 mg of dexamethasone, was found to be abnormal in 28.5, 71, and 25 percent, respectively, of the patients with SCCL, compared with 18, 65, and 29.5 percent in patients with other types of cancer (P greater than 0.3). The possibility of ectopic ADH secretion was assessed by a standard water loading test, which showed excretion impairment in 60 percent of patients with SCCL and 68 percent of patients with other cancers (P greater than 0.9). Neither the stage of neoplastic disease, sites of metastatic deposits, nor performance status of the patients correlated with abnormalities of water and cortisol metabolism, indicating that such abnormalities are common in patients with all types of cancer. These data do not suggest that subclinical disturbances of adrenal function or water excretion are characteristic of any histologic type of cancer. The precise mechanism(s) underlying these abnormalities are unknown.

Adrenocorticotropic Hormone↗
PubMed1982

Hypothalamic and pituitary dysfunction in obese males.

Previous studies have indicated dysfunction of the hypothalamic-hypophyseal axis in obesity. We have studied 12 obese males to further characterize the extent of this dysfunction. The hypothalamic-hypophyseal-gonadal axis is normal as determined by the testicular response to human chorionic gonadotropin (hCG), the pituitary response to 200 micrograms gonadotropin-releasing hormone (GnRH), and the hypothalamic-pituitary-testicular response to clomiphene. Although L-dopa suppresses prolactin normally, the ability of thyrotropin releasing hormone (TRH) to stimulate the release of prolactin and thyroid stimulating hormone (TSH) is blunted. These latter responses are inversely related to the degree of obesity. The response to chlorpromazine, a hypothalamic stimulus for prolactin secretion, is also blunted, and to a greater extent than the prolactin response to TRH. These data indicate that exogenous obesity in males is associated with more extensive hypothalamic and pituitary dysfunction than previously realized. The abnormalities with regard to prolactin and TSH release become progressively worse when body weight exceeds 200 percent of ideal. In addition, when evaluating pituitary function with regard to gonadotropin release, obese males may have an abnormal response to 100 micrograms GnRH but respond normally to 200 micrograms.

Adult↗
PubMed1981

Cyproheptadine in the control of Cushing's disease.

A patient with Cushing's disease was treated with cyproheptadine with concomitant remission of the disease for 60 months. Despite clinical improvement and achievement of normal levels of cortisol excretions, her menstruation-related cyclic surge of cortisol secretion was supranormal. The mode of action of cyproheptadine was studied by the administration of metyrapone. Long-term administration of cyproheptadine appeared to normalize excessive adrenocorticotropic hormone (ACTH) production by reducing the frequency and the peak levels of episodic secretion of ACTH.

Adrenocorticotropic Hormone↗
PubMed1981

The Albright syndrome associated with acromegaly: report of a case and review of the literature.

The association of the Albright syndrome (polyostotic fibrous dysplasia of bone, hyperpigmented skin macules, and endocrine disorders) with acromegaly has been infrequently substantiated. The case of an 18-year-old girl with the classic Albright syndrome and acromegaly is described. The patient had a history of coarsening of acral and facial features, an insulin-resistant form of diabetes mellitus and elevated fasting growth hormone values. Neuro-endocrine studies demonstrated failure of growth hormone to suppress to less than 5 ng/ml during an oral glucose tolerance test, and the abnormal release of growth hormone upon injection of thyrotropin-releasing hormone. Although L-dopa failed to decrease growth hormone levels, bromocriptine produced a modest decline in growth hormone within two hours of ingestion. The patient had also experienced secondary amenorrhea with sub-normal follicle-stimulating-hormone (FSH) and luteinizing hormone (LH) levels, both of which demonstrated a prolonged sluggish response to an injection of gonadotropin-releasing hormone (GnRH); this response suggested hypogonadotropic hypogonadism, possibly on the basis of a tumor involving both pituitary and hypothalamus. Sellar polytomography demonstrated an enlarged sella with dorsal erosion and an asymmetric floor. Computerized tomography of the brain visualized a suprasellar mass extending into the hypothalamus. These findings suggest a hypersecretion of hypothalamic releasing factors, pituitary hormones, or both as an etiology for the endocrinopathy in this patient, and lend support to the theory that the endocrinopathies associated with the Albright syndrome result from over-production of hypothalamic-releasing hormones or autonomous secretion of pituitary hormones from an adenoma.

Acromegaly↗
PubMed1980

Blood gastrin levels in hyperthyroidism.

Serum gastrin concentrations were measured in 22 untreated and 10 treated thyrotoxic patients. In contrast to similar studies carried out in Japan, serum gastrin levels were normal in hyperthyroid subjects. The mean value in hyperthyroid subjects (94.8 +/- 34.5 pg/ml) was higher than that in the treated patients (73.6 +/- 33.2 pg/ml), but the difference was not significant (P greater than 0.05).

Adult↗
PubMed1980

Management of virilizing congenital adrenal hyperplasia with cyproheptadine.

Hyperandrogenism secondary to hypersecretion of ACTH in patients with congenital adrenal hyperplasia is frequently a problem in therapeutic management. Despite the use of steroids and antiandrogens, virilism often persists. This paper reports the beneficial effects of cyproheptadine in two adult patients with C-21 hydroxylase deficiency who had persistently increased secretion of androgens while on supraphysiologic doses of prednisone. When cyproheptadine was administered in addition to steroids, plasma androgen levels, ACTH, and urinary 17-ketosteroid and pregnanetriol excretion rates returned to normal and clinical improvement was observed. Discontinuation of cyproheptadine therapy in one patient resulted in prompt recurrence of hyperandrogenemia, which was again ameliorated with reinstitution of the drug. From these findings, I conclude that while glucocorticoids are the mainstay of management of virilizing congenital adrenal hyperplasia, cyproheptadine may be an effective adjunct in some patients with this disorder.

Adrenal Hyperplasia, Congenital↗
PubMed1979

The effects of L-dopa on in vitro and in vivo calcitonin release from medullary thyroid carcinoma.

The in vivo and in vitro effects of the dopamine precursor L-dopa on basal and stimulated calcitonin release from medullary thyroid carcinoma have been studied. In six studies of five patients, including 7- to 8-h control and test periods, oral L-dopa depressed basal calcitonin secretion by an average of 35%; the peak effects occurred within 30 min of drug administration and lasted for as long as 4 h. In seven of eight patients with medullary thyroid carcinoma (three infused with calcium and five with pentagastrin), L-dopa inhibited to varying degrees peak levels of stimulated calcitonin release and total calcitonin secretion; basal calcitonin levels, where directly tested, also again generally fell after L-dopa by an average of 50%. In a short term organ culture system using medullary thyroid carcinoma tissues, calcitonin secretion into the medium was linear with time for 2 h and could be stimulated by dibutyryl cAMP and pentagastrin. L-Dopa, in concentrations from 0.5--3.0 mM, inhibited basal calcitonin secretion (ranging from 25--55%). Addition of the L-dopa decarboxylase inhibitor, alpha-methyldopa, abolished the inhibitory effects of L-dopa. Another L-dopa decarboxylase inhibitor, carbidopa, stimulated calcitonin secretion in vitro; this effect may be independent of the L-dopa decarboxylase-inhibiting properties of this drug since alpha-methyldopa alone did not stimulate calcitonin secretion. It is concluded that the amine precursor L-dopa inhibits calcitonin release in patients with medullary thyroid carcinoma; the in vitro studies suggest that a portion of this effect may involve direct metabolism of L-dopa to dopamine in the tumor tissue itself. The importance of considering the uptake of amine precursors and the subsequent metabolism of these compounds as a modulating site for peptide hormone release from peripheral endocrine tissues is stressed.

Calcitonin↗
PubMed1979

Hypoglycemic coma with ketoacidosis in nondiabetic alcoholics.

Five nondiabetic, chronically alcoholic patients presented in a comatose state during a two month prospective study and were found to be ketoacidotic. All of the patients were men, 28 to 59 years old. The usual history was one of chronic heavy, daily alcohol consumption until one to three days before presentation, when persistent anorexia, abdominal distress, nausea and vomiting commenced, with abstention from food thereafter. The patients were found to be in hypoglycemic coma, with diaphoresis, tachypnea and tachycardia, and immediately awoke when intravenous infusion of glucose was started. Serum glucose ranged between 19 and 27 mg per dl, the average arterial pH was 7.19 and the mean anion gap was 25 mEq per liter. Reaction with Acetest tablets was positive for ketones in both serum and urine in three of the patients. Serum beta-hydroxybutyrate was elevated in the four patients in whom it was measured. Lactic acidosis was not present. All patients were managed with prolonged intravenous infusions of glucose and saline solutions, and within 12 to 18 hours they were feeling well and findings on serum chemistry studies were normal. Follow-up after three months showed no repeated difficulties. The combination of alcoholic ketoacidosis and hypoglycemic coma in nondiabetic persons has not been described in the literature as a clinical entity; it may, however, represent a common but unrecognized syndrome. Therefore, because of its potentially serious consequences and because treatment is simple and effective, this entity must be thought of in alcoholic patients with altered mental status.

Acidosis↗
PubMed1979

A study of age-dependent changes in thyroid function tests in adults.

Total serum thyroxine (T4), triiodothyronine (T3), T3 resin uptake (T3U), thyrotrophin (TSH), and reverse T3 (rT3) were measured in 209 healthy adults 20--89 yr old. Mean T4 values for men were stable throughout life, but in females under age 60, T4 values were significantly higher than in older women. Values for T3U in males were significantly higher than in females throughout all decades, although females had a significant increase in T3U after age 60. TSH values increased significantly in females over age 60. Throughout all decades, males had stable TSH levels that were slightly higher than the female results before age 60 and lower thereafter. Mean serum T3 declined similarly for both sexes with increasing age, although not to the extent previously reported. Men had significantly higher mean rT3 values over all decades than females, although female rT3 levels decreased after age 50 whereas males maintained stable values. The physiologic reasons for these findings may be due to sex-related changes in binding proteins and alterations in metabolic clearance rates, production, and degradation of these hormones with increasing age.

Adult↗