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Biomedical subjects

V V Gossain

Publications and source records attributed to V V Gossain.

18 recordsLinked to original sources

Treatment of hyperthyroidism in community hospital.

The preferred treatment of hyperthyroidism remains controversial. Most of this data is derived from large, university-based medical centers. We report here our experience with treatment of hyperthyroidism in a community setting. This involves 144 patients with hyperthyroidism who were seen over a 10 year period at Michigan State University Clinical Center and were treated in the community hospitals and private physicians' offices, and by community surgeons. Follow-up data were available on 119 of these patients; 105 of them were hyperthyroid because of Graves' disease and multinodular goiter. Patients were encouraged to make their own decisions regarding choice of therapy, as independently as possible. Sixty-five percent of these patients were treated by 131I, 18% by antithyroid drugs, and 17% by surgery. The mean follow-up period was 2.5 years (range 2 months to 19 years). Hyperthyroidism was controlled in 84% of the patients treated by 131I and 83% of the patients treated by surgery. Forty percent of the patients treated by 131I and 33% treated by surgery became hypothyroid. Fifty percent of the patients achieved remission when treated by antithyroid drugs alone. Our results indicate that when patients are encouraged to make their own decisions regarding the treatment of hyperthyroidism, their choices are similar to those of the thyroidologists. Secondly, the results obtained with different modalities of treatment for hyperthyroidism in a community setting are similar to those obtained in university medical centers.

Adolescent

Adrenal function in 15 dogs with insulin-dependent diabetes mellitus.

Pituitary-adrenal function was assessed by a combined dexamethasone suppression-ACTH stimulation test in 15 diabetic and 9 healthy dogs. In both groups, plasma cortisol concentrations decreased (P less than 0.001) after dexamethasone administration and increased (P less than 0.001) after ACTH administration. Differences between groups (P greater than 0.05) and group-by-time interactions were not significant (P greater than 0.05). Seemingly, adrenal function was not altered in well-regulated diabetic dogs.

Animals

Alteration of radioactive iodine uptake after treatment of hyperthyroidism with iodine 131.

To determine whether a therapeutic dose of iodine 131 affects the results of 24-hour radioactive iodine uptake (RAIU) testing, we reviewed records of hyperthyroid patients previously treated with 131I at Michigan State University and its affiliated hospitals. We identified 26 patients who had had clinical evaluation and determination of the serum thyroxine (T4) level, triiodothyronine resin uptake (T3RU), and RAIU (using 131I) within two weeks before and several months after the therapeutic dose of 131I. Before treatment, all patients had clinical hyperthyroidism, with an elevated T4 level and increased T3RU and RAIU. After treatment with 131I, eight patients (31%) had an RAIU that was discordant with their clinical and biochemical (T4 and T3RU) assessment. In six patients (23%) of the RAIU was inappropriately high, and in two patients (8%) it was inappropriately low. Since we did not identify any other factors known to interfere with the results of RAIU testing, we conclude that a therapeutic dose of 131I, may by itself increase or decrease a subsequent RAIU determination; therefore, after treatment with 131I, RAIU is not a good diagnostic index of thyroid activity.

Adult

Effect of thymosin (fraction 5) on the plasma levels of glucose and glucoregulatory hormones in humans.

Several interactions between thymosin (fraction 5) and the endocrine system have been described in animals, but its effects in humans have not been studied. Plasma levels of glucose, insulin and glucagon were obtained in response to a glucose load before and after treatment with thymosin in eight patients. The glucose tolerance was normal in all subjects and remained so following thymosin administration. No significant changes in the levels of glucagon and insulin were obtained. In six patients, baseline levels of plasma cortisol and ACTH were also obtained. Four out of six patients demonstrated an increase in ACTH levels although the mean differences did not achieve statistical significance. Plasma cortisol levels also did not change significantly. We conclude that thymosin given over a short term is unlikely to significantly influence carbohydrate metabolism. Since four out of six patients showed an increase in basal ACTH levels, it suggests that thymosin may affect the hypothalamic pituitary/adrenal axis. However, further study is needed for complete evaluation of these effects.

Adrenocorticotropic Hormone

Elevated beta-human chorionic gonadotropin and a search for cancer.

Elevated human chorionic gonadotropin levels may be an early, and occasionally the only, manifestation of embryonal cell carcinoma. A 24-year-old man presented with gynecomastia, galactorrhea, and elevated beta-human chorionic gonadotropin levels, which led to an extensive (but nonrevealing) search, including computed tomography and selective testicular vein catheterization, for malignancy. Since the testicle was considered as the most likely site of tumor, right orchiectomy and right common iliac lymph node biopsy were performed. The testicle was normal, but the lymph node contained elements of embryonal and choriocarcinoma. Following chemotherapy, beta-human chorionic gonadotropin levels were normalized and the patient appears "cured." This case emphasizes the need for an extensive search for malignancy and consideration of orchiectomy in such instances in order to achieve a favorable outcome.

Adult

Hormonal effects of smoking--II: Effects on plasma cortisol, growth hormone, and prolactin.

Effect of smoking on the plasma levels of cortisol, growth hormone, and prolactin was evaluated in a group of smokers and nonsmokers. Plasma levels of these hormones were measured under basal conditions and following a short burst of smoking. In addition, to determine the mechanism of action of nicotine on the release of these hormones, rat renal cortical slices were incubated with nicotine and the generation of cyclic AMP was measured in vitro. Increasing concentrations of nicotine in the incubation medium resulted in increased generation of cyclic AMP. Basal levels of plasma cortisol were similar for both smokers and nonsmokers. After smoking, the cortisol levels increased significantly among smokers only and the levels achieved were significantly higher compared with nonsmokers. Mean prolactin curves were higher among nonsmokers compared with smokers, whereas growth hormone levels were similar in the two groups. These data suggest that the effects of smoking on pituitary/adrenal hormones differ among smokers and nonsmokers and that these effects may be mediated through increased generation of cyclic AMP induced by nicotine.

Adult

Thyroid hormone levels during glucose tolerance test in euthyroid subjects.

Twelve normal, healthy, clinically and biochemically proven euthyroid volunteer subjects (age 19-35) were administered a standard glucose tolerance test (100 g glucose orally) and thyroxine (T4), triiodothyronine (T3) and reverse triiodothyronine (rT3) levels were determined by specific radioimmunoassays to determine the acute effect of glucose and insulin on peripheral monodeiodination of thyroxine. The fasting levels of T4, T3, rT3 and free thyroxine were 82.4 nmol/l, 1.7 nmol/l, 0.52 nmol/l, and 0.22 nmol/l, respectively, and these levels were unchanged during the 3 hours post-glucose load. The rise and fall of glucose and insulin levels were typical of the standard responses normally observed in the glucose tolerance test. The variations in insulin and glucose levels were not correlated with thyroid hormone concentrations at any interval during the test. It is therefore concluded that dietary glucose does not acutely cause shifts in peripheral monodeiodination of thyroxine in healthy euthyroid subjects.

Adult

Effect of tolbutamide on plasma renin activity.

The effect of tolbutamide on renin secretion in rats was studied in vivo, and in vitro. Administration of tolbutamide in doses of 12.5 and 25 mg/kg body wt ip to two groups of rats produced no significant change in plasma renin activity compared to the control group. In the in vitro experiments renal cortical slices were incubated with increasing concentrations of tolbutamide (0--4 mg/ml). No significant increase in the net renin production was observed, whereas the concentration of cyclic AMP increased significantly in the incubation medium. These findings suggest that in the intact rats tolbutamide does not increase plasma renin activity. In the renal cortical experiments although tolbutamide increased cyclic AMP production, the increase may not have been sufficient to stimulate the net renin production. These results are of biological significance because of the possible effects of tolbutamide and increased plasma renin activity on the cardiovascular system.

Animals

Plasma alpha-cell glucagon in primary hyperparathyroidism.

Plasma glucose, insulin, and alpha-cell glucagon profiles were examined in ten adults with uncomplicated primary hyperparathyroidism before and 8-12 week after surgical removal of a single parathyroid adenoma. Treatment restored abnormal serum calcium and phosphorus concentrations to a normal range and reduced serum parathyroid hormone levels from 47 +/- 4 to 16 +/- 4 mu 1 Eq/ml (normal = 0-40). Plasma glucose curves during 100-g oral glucose tolerance, 30 min intravenous glucose (1.5 g/min), or arginine infusions (1.0 g/min) did not differ before and after surgery. However, basal and peak insulin concentrations were higher before treatment during these tests (p less than 0.05). Basal glucagon levels were unaffected by hyperparathyroidism (72 +/- 7 versus 77 +/- 7 pg/ml). Peak 30 min values after arginine provocation were also similar before and after treatment as was maximal suppression of basal glucagon during glucose infusions. Four patients also received 400 g lean beef meals. Glucose and glucagon responses over 240-min periods were nearly identical before and after surgery despite higher insulin levels before treatment. It is concluded that elevated serum parathyroid hormone and plasma insulin concentrations in primary hyperparathyroidism do not relate to abnormalities of plasma alpha-cell glucagon in the basal state or after glucose, arginine, or protein administration.

Adult

Drug-induced hyponatraemia in psychogenic polydipsia.

Two patients with psychogenic polydipsia developed hyponatraemia, one in association with administration of hydrochlorothiazide and the other with that of tolbutamide. It is suggested that the increased fluid intake in such patients may make them more susceptible to the development of hyponatraemia from thiazide or sulphonylurea compounds.

Humans

Increased free thyroxine in a euthyroid patient with thyroxine-binding globulin deficiency.

An unusual finding of elevated free thyroxine (FT4) concentration coexistent with familial low thyroxine-binding globulin (TBG) is described in a euthyroid patient. Clinical and other laboratory tests were normal and consistent with a clinical diagnosis of euthyroidism. Low TBG (TBG capacity 3-10 mug/100 ml) was confirmed by various electrophoretic procedures and by TBG immunoassay (0.9 mg/100 ml). Serum T4 concentration was low (2.0-5.5 mug/100 ml). Triiodothyronine (T3) resin uptake was increased (88-93%) and the free thyroxine index was normal. Twenty-four-hour thyroidal 131I uptake was normal and varied between 13-20%. Serum thyroid-stimulating hormone (less than 2 muunits) and T3 concentration (80 ng/100 ml) were also normal. Long-acting thyroid stimulator (LATS) was not present. Free T4 concentration measured by dialysis procedure was markedly elevated (9.2-12.1 ng/100 ml). Pulse T3 and T4 tracer kinetic studies by the single compartmental method revealed accelerated blood disappearance of T4 (t 1/2 = 3.7 days) but normal disappearance of T3 (t 1/2 = 2.1 days). Extrathyroidal hormonal iodine pool (569 mug) was in the range of normals. T4 degradation rate (144 mug/70 kg/day) was moderately elevated over the euthyroid mean values, but was still close to or within the upper normal range. T3 degradation was normal (34 mug/day). Failure to develop hyperthyroidism in the presence of elevated free T4 levels, but with normal T3 concentration and dynamics, may suggest that T3, not T4, plays a major role in regulating metabolic activity; alternatively, euthyroidism in this low-TBG patient despite elevated free T4 concentration may simply be explained on the basis of a daily T4 disposal rate which was not clearly abnormal.

Humans

Co-existent diabetes mellitus and diabetes insipidus, a familial disease.

Three male siblings with diabetes mellitus are described, two of whom also had coexistent diabetes insipidus. The co-existence of diabetes mellitus and insipidus appears to represent a single genetic abnormality and may or may not be accompanied by primary optic atrophy. Chlorpropamide was effective in controlling the symptoms of diabetes mellitus and diabetes insipidus.

Adult

Plasma renin activity in juvenile diabetes mellitus and effect of diazoxide.

Low plasma renin activity (PRA) has been reported in patients with long-term diabetes mellitus complicated by hypertension and nephropathy. We have assayed PRA in twelve normal subjects and in eight age- and sex-matched juvenile diabetics of greater than twelve years' duration without hypertension and nephropathy under control conditions and following stimulation with diazoxide. During control conditions PRA did not decrease with time in the diabetics as it did in the normals. Following diazoxide infusion, PRA increased in both groups, and although the levels were often higher in diabetics than in normals, the mean differences were not statistically significant. The findings are consistent with the suggestion that PRA is normal or possibly elevated in clinically uncomplicated insulin-dependent diabetes mellitus and decreases with establishment of hypertension and nephropathy.

Adult

Hyperparathyroidism and pregnancy: case report and review.

In pregnant women with symptomatic hyperparathyroidism, parathyroidectomy should be undertaken during the second trimester. We feel that the woman who is initially diagnosed well into the third trimester should be treated medically unless the hypercalcemia worsens or other complications occur. Since the treatment of asymptomatic hyperparathyroidism itself is controversial, it is even more difficult to define the treatment plan for an asymptomatic pregnant patient who has primary hyperparathyroidism. However, a recent consensus panel recommended that young patients with asymptomatic hyperparathyroidism be treated surgically. Accordingly, we believe that the asymptomatic pregnant patient should also be treated surgically, preferably in the second trimester. Whether a patient is treated medically or surgically in these situations, the pregnancy should be considered high-risk. The neonate should be monitored carefully for signs of hypocalcemia or impending tetany. If the mother is treated medically to term (or if spontaneous or elective abortion occurs), the mother should be monitored for hyperparathyroid crisis postpartum. Sudden worsening of hypercalcemia can result from the loss of the placenta (active placental calcium transport may be somewhat protective) and dehydration. Finally, every effort should be made to make the definitive diagnosis early in pregnancy in order to initiate optimal management. The diagnosis should be suspected during pregnancy if the following conditions exist: appropriate clinical signs or symptoms (especially nephrolithiasis or pancreatitis), hyperemesis beyond the first trimester, history of recurrent spontaneous abortions/stillbirths or neonatal deaths, neonatal hypocalcemia or tetany, or a total serum calcium concentration greater than 10.1 mg/dL (2.52 mmol/L) or 8.8 mg/dL (2.2 mmol/L) during the second or third trimester, respectively.

Abortion, Spontaneous

Effect of pregnancy on thyroxine binding globulin (TBG) in partial TBG deficiency.

An unusual opportunity was afforded to study the effect of endogenous increase in estrogen on thyroxine binding globulin (TBG) throughout pregnancy in a partially TBG-deficient female who conceived subsequent to initial examination. TBG binding of 125I-thyroxine (T4) before and up to four months of pregnancy was low in comparison to normal. Starting from six months and up to the end of pregnancy, TBG activity showed a definite increase although still below normal. TBG binding capacity increased from a low value of 4.2 microgram T4/100 ml ,efore pregnancy to a value 9.3 microgram T4/100 ml in the last month of pregnancy. This was accompanied by an increase in immunoassayable TBG from less than 1 mg/100 ml in the second month of pregnancy to 1.9 mg/100 ml in the last month, and an increase of T4 from 3.1 microgrom/100 ml to 4.3 microgram/100 ml. Two weeks after delivery, TBG binding of 125I-T4 showed a precipitous decline to the abnormally low distribution noted prior to and during the early months of pregnancy. TBG binding activity was normal in the cord blood of the infant. These studies provide the first direct evidence that increase in endogenous estrogen results in detectable increases in TBG concentration in the human with partial TBG deficiency.

Adult

Essential hypernatremia.

Described is a patient who presented with hypernatremia in the absence of dehydration. Further investigation revealed a tumor in the hypothalamic area, and evidence of anterior pituitary hypofunction. Water loading did not correct hypernatremia, and the results of the water-loading test suggested that hypernatremia had resulted from an elevated "osmotic set point" for the release of antidiuretic hormone, ie, "essential hypernatremia."

Adolescent