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Biomedical subjects

G S Kidd

Publications and source records attributed to G S Kidd.

At least 37 records · Page 2Linked to original sources
PubMed1987

Fine needle aspiration of the thyroid. Use in an average health care facility.

Fine needle aspiration of the thyroid is suggested as an initial diagnostic procedure in the evaluation of thyroid nodules. Some proponents of the procedure, however, believe that fine needle aspiration should be restricted to centers in which each operator obtains at least 500 biopsy specimens annually. Reviewed were 155 biopsy specimens obtained over three and one-half years, and the sensitivity of fine needle aspiration was determined to be 100 percent, the specificity to be 47.4 percent, and the accuracy to be 73 percent. A review of the literature revealed the sensitivity in larger series to range between 92 and 98 percent, specificity to range between 52 and 99.5 percent, and accuracy to range between 56.1 and 91.3 percent. The surgical yield of carcinoma was 64 percent in patients evaluated with fine needle aspiration, whereas the yield was 26 percent in those who underwent surgery without fine needle aspiration. These results appear to justify the use of fine needle aspiration in the evaluation of nodular thyroid disease at average-sized health care centers.

Adult↗
PubMed1987

The role of calcitonin in the development and treatment of osteoporosis.

CT is a peptide hormone produced predominantly by thyroid C cells and probably to a lesser extent by extrathyroidal tissues. Although its physiological function has not yet been established, it is a pharmacological inhibitor of osteoclastic bone resorption. There is currently no convincing evidence that naturally occurring or iatrogenic CT deficiency is involved in the pathogenesis of osteoporosis; however, a selective examination of patients with various rates of bone turnover would help to resolve this issue. As a pharmacological inhibitor of bone resorption, CT has potential usefulness in the therapy of osteoporosis. CT has been shown to stabilize or modestly increase indices of cortical and trabecular bone mass and total body calcium when administered to patients with established osteoporosis for periods of 1-2 yr. The increments in bone mass seen in some studies appear to be transient and are likely due to reductions in bone resorption with bone formation remaining unaffected until remodeling spaces are filled. The duration and magnitude of these increases are probably limited by the eventual decline in bone formation as remodeling equilibrium is reestablished. Therefore, reduction in the rate of bone loss with maintenance of the existing skeletal mass, rather than significant sustained increases in bone mass, should be considered the most realistic therapeutic goal with this agent. Whether or not a reduction in the rate of bone loss persists for longer periods needs further evaluation as does the important issue of subsequent fracture rates. The identification of patients with increased bone resorption rates (high turnover osteoporosis) should help provide a basis for more selective treatment of those patients who would be most likely to respond to this form of therapy. Whether there is additional benefit to using intermittent CT concurrently or sequentially with bone formation stimulating agents (coherence therapy) also needs to be explored. CT may also be of benefit in the prevention of osteoporosis, particularly in postmenopausal women who are unable or unwilling to take estrogen replacement. These potential benefits must be weighed carefully against the current cost of CT and the inconvenience of it having to be given by injection, problems which should be solved by future research.

Calcitonin↗
PubMed1987

Ectopic thyroid tissue on thallium/technetium parathyroid scan.

The thallium 201/technetium 99m pertechnetate radionuclide study is becoming widely accepted as a means of localizing abnormal or aberrantly located parathyroid tissue. We describe a case in which ectopic retrosternal thyroid tissue appeared as a parathyroid adenoma on thallium-201/technetium-99m pertechnetate scan. Physicians who use this radionuclide study should be aware of the possibility of false-positive images within the mediastinum.

Adenoma↗
PubMed1987

Effects of hypothyroidism and short-term aging on whole blood thromboxane and arterial prostacyclin synthesis.

Hypothyroidism results in decreased platelet aggregation and has unique effects on the development of atherosclerosis and angina pectoris. Because prostacyclin and thromboxane A2 profoundly influence platelet function and vascular tone and are thought to be important in the development of atherosclerosis and angina pectoris, we studied the effects of hypothyroidism in rats on the in vitro elaboration of prostacyclin passively by aortic tissue and of thromboxane A2 by thrombin-stimulated whole blood. Hypothyroidism induced by iodine 131 (given at age 7 weeks) persistently caused a mild decrease in platelet count (P less than 0.01) and 30% decrease in immunoreactive thromboxane B2 (the hydrolysis product of thromboxane A2) generation per platelet (P less than 0.01) compared with age-matched euthyroid rats. Between 20 and 23 weeks of age immunoreactive 6-ketoprostaglandin F1 alpha (the hydrolysis product of prostacyclin) generation decreased by 30% in euthyroid rats. In hypothyroid rats less than 23 weeks of age, 6-ketoprostaglandin F1 alpha production was the same as that of age-matched euthyroid rats. With further aging, 6-ketoprostaglandin F1 alpha production did not decrease as it did in euthyroid rats. Hypothyroid rats more than 20 weeks old had, therefore, significantly greater 6-ketoprostaglandin F1 alpha production than age-matched euthyroid rats (P less than 0.005). L-Thyroxine given daily for 28 days to 23-week-old hypothyroid rats caused a rapid increase in platelet count and a delayed normalization of the thromboxane synthetic abnormality. 6-Ketoprostaglandin F1 alpha production transiently increased in response to L-thyroxine, but decreased to the euthyroid level after 28 days of therapy.(ABSTRACT TRUNCATED AT 250 WORDS)

6-Ketoprostaglandin F1 alpha↗
PubMed1987

Osteoporosis unmasked by hyperthyroidism in a young man with osteogenesis imperfecta.

A young man presented with a vertebral fracture and generalized osteopenia that was initially attributed to coexisting hyperthyroidism. However, the rarity of fractures in young men with hyperthyroidism and the finding of blue sclerae led to the diagnosis of osteogenesis imperfecta. Since vertebral fractures are uncommon in young men with osteogenesis imperfecta, we postulate that the combined effects of the two disorders contributed to his clinical presentation.

Adult↗
PubMed1986

Lithium-associated thyrotoxicosis.

Primary hypothyroidism developed in a 57-year-old woman treated for eight years with lithium carbonate for manic-depressive illness, and nine months later she became thyrotoxic. Although autoimmune disease appeared to be responsible, lithium was suspected to play a contributory role in both phases of her illness. This is the first reported case of hyperthyroidism following hypothyroidism in a lithium-treated patient. The 24 reported cases of lithium-associated thyrotoxicosis and the possible mechanisms that may explain this poorly understood phenomenon are also reviewed.

Autoimmune Diseases↗
PubMed1986

Hyperthyroidism following hypothyroidism.

Two patients are presented who developed autonomous thyrotoxicosis following a diagnosis of primary hypothyroidism. In one of these patients, antibodies to the TSH receptor were typical of Graves' disease when measured as thyrotropin binding inhibitor immunoglobulins (TBII) and as human thyroid adenylate cyclase stimulating (HTACS) activity, while a needle biopsy of the thyroid gland was consistent with lymphocytic thyroiditis. Twenty-one other reported cases of this unusual sequence found in the literature are reviewed. This occurrence is more common than is generally appreciated.

Adult↗
PubMed1986

Lactic acidosis in pheochromocytoma.

Lactic acidosis is not generally recognized as a complication of pheochromocytoma. We review three prior case reports of lactic acidosis in patients with pheochromocytoma and one report of lactic acidosis following epinephrine poisoning and describe an additional case report of a patient with lactic acidosis in whom an unsuspected pheochromocytoma was discovered at autopsy. The pathophysiology of lactic acidosis in pheochromocytoma is related to the effect of catecholamines on intermediary metabolism and the peripheral circulation. Although the possible development of lactic acidosis in persons with pheochromocytoma is underappreciated, the differential diagnosis of lactic acidosis should include this tumor.

Acidosis, Lactic↗
PubMed1984

Pure primary hyperaldosteronism due to adrenal cortical carcinoma.

A 47-year-old woman is described who had pure primary hyperaldosteronism due to an adrenal cortical carcinoma. This may represent the first such case in which modern laboratory tests allowed specific diagnosis and exclusion of hypersecretion of other adrenal steroids, and also the first reported case in which modern localizing procedures have been utilized. Other interesting facets of the case include calcification of the tumor, visualization with 131l iodomethylnorcholesterol , metaplastic histologic changes, and coexistent bilateral renal artery fibromuscular disease.

Adrenal Cortex Neoplasms↗
PubMed1983

Radioiodine-induced thyroid storm. Case report and literature review.

Thyroid storm developed following radioiodine therapy in a 43-year-old man with Graves' disease, weight loss, myopathy, severe thyrotoxic hypercalcemia, and a pituitary adenoma. The hypercalcemia may have been a significant, and previously unreported, predisposing factor for the radioiodine-associated thyroid storm. This case and 15 other well-documented cases of radioiodine-associated storm found in the literature are reviewed, as are several other cases of less severe exacerbations of thyrotoxicosis associated with radioiodine therapy. Although not often seen, these complications are often fatal. High-risk patients, such as the elderly, those with severe thyrotoxicosis, and those with significant underlying diseases, may benefit from preventive measures such as the judicious use of thyrostatic medications during the periods before and after isotope administration.

Adenoma↗
PubMed1983

Reduced bone mineral content in totally thyroidectomized patients: possible effect of calcitonin deficiency.

To further investigate the relationship between calcitonin deficiency and osteoporosis, we have measured bone mineral content (BMC) by single photon absorptiometry in patients made iatrogenically calcitonin deficient by prior total thyroidectomy for thyroid cancer. Compared to sex-, age-, height-, and weight-matched normal controls, male patients had a significantly lower mean BMC at the midradius (1.162 +/- 0.02 vs. 1.301 +/- 0.05 g/cm; P less than 0.02) and the distal radius (1.180 +/- 0.04 vs. 1.338 +/- 0.04 g/cm; P less than 0.01). Female patients also had a significantly lower BMC at the midradius compared to those of a similarly matched group of normal controls and a group of patients on L-T4 suppression for nodular goiters (0.791 +/- 0.04 vs. 0.896 +/- 0.05 vs. 0.891 +/- 0.03 g/cm; P less than 0.025). We conclude that calcitonin deficiency from surgical thyroidectomy is associated with significant decreases in bone mineral content in both sexes. This lends further support to the concept that calcitonin deficiency may be an important causative factor in the development of osteoporosis.

Adult↗
PubMed1982

The effects of pyridoxine on pituitary hormone secretion in amenorrhea-galactorrhea syndromes.

Six patients with amenorrhea, five of whom had galactorrhea and elevated PRL levels, were evaluated on a metabolic ward. All had normal sella tomograms, normal thyroid functions, and routine laboratory evaluations. None of the patients had taken any medication in the previous 6 months. On alternate days, five patients received 500 microgram of TRH iv with the measurement of PRL, TSH, FSh, LH, and hGH; 500 mg L-dopa orally with the measurement of PRL, FSH, and LH; a bolus infusion of 300 mg pyridoxine (B6) with measurement of PRL, hGH, TSH, FSH, and LH; and 25 mg chlorpromazine (CPZ) im with the measurement of PRL, LH, and FSH. The patients were then discharged on 600 mg oral pyridoxine/day and were readmitted for a repeat of the complete protocol 21 days later. The patients were continued on 600 mg oral pyridoxine for 3-4 months with monthly evaluations of serum PRL, LH, and FSH levels. These evaluations continued for 3 months after discontinuing pyridoxine. There was no demonstrable change in serum PRL after acute or chronic B6 therapy, mor was there a significant change in the response of PRL to CPZ, L-dopa, or TRH. The mean basal PRL was 97.5 +/- 9.7 ng/ml and after 3-4 months of oral pyridoxine was 97.1 +/- 14.8. In addition, there was no significant change in LH or FSH levels in response to acute or chronic B6, TRH, L-dopa, or CPZ. Neither acute B6 infusion nor chronic B6 therapy had any effect on TSH or the TSH response to TRH. Finally, acute B6 infusion had no effect on hGH levels and there were no paradoxical hGH responses to TRH. Two patients began having regular menses while on chronic pyridoxine. Their hormonal responses did not differ from those of the group, however.

Adult↗
PubMed1980

Skeletal responsiveness in pseudohypoparathyroidism. A spectrum of clinical disease.

Three cases of pseudohypoparathyroidism with roentgenographic evidence of hyperparathyroid bone disease are described. Renal resistance to exogenous parathyroid hormone (PTH), the hallmark of pseudohypoparathyroidism, was documented by markedly blunted or absent urinary phosphate and cyclic AMP responses to parathyroid extract. At the time of diagnosis all patients were hypocalcemic and hyperphosphatemic with elevated serum alkaline phosphatase levels and subperiosteal resorption noted on skeletal films. Bone biopsy in one patient revealed a histologic appearance consistent with hyperparathyroidism. Serum PTH levels, measured in two patients while they were hypocalcemic, were elevated. None of the patients had short stature, brachydactyly, subcutaneous calcification or mental deficiency. These cases are compared to the 15 well-documented cases previously reported. The presently available information on pseudohypoparathyroidism indicates a variable skeletal response to PTH mediated by several factors extrinsic to bone and suggests that pseudohypoparathyroidism with hyperparathyroid bone disease is one extreme of a clinical spectrum of skeletal responsiveness to PTH. This disorder is part of an expanding clinical picture which makes pseudohypoparathyroidism a diagnostic consideration in any patient with unexplained hypocalcemia, hyperphosphatemia, elevated alkaline phosphatase levels or metabolic bone disease.

Adolescent↗
PubMed1979

Mild chronic watery diarrhea-hypokalemia syndrome associated with pancreatic islet cell hyperplasia. Elevated plasma and tissue levels of gastric inhibitory polypeptide and successful management with nicotinic acid.

A 46 year old woman is described who had a 13 half year history of watery diarrhea associated with hypokalemia and hypochlorhydria. The diarrhea was secretory as measured by triple lumen tube perfusion and was associated with an increased concentration of fasting plasma immunoreactive gastric inhibitory polypeptide (GIP) of 750 pg/ml which was stimulated to 4,000 pg/ml after a standard meal. The diarrhea decreased after partial pancreatectomy. Diffuse pancreatic islet cell hyperplasia was present and, although GIP was unmeasureable in the pancreas of normal subjects, it was at least 83 ng/g wet weight in this patient. Postoperatively, the patient's diarrhea responded dramatically to the oral administration of nicotinic acid.

Achlorhydria↗
PubMed1979

The hypothalamic-pituitary-testicular axis in thyrotoxicosis.

The hypothalamic-pituitary-testicular axis was evaluated in seven men with thyrotoxicosis due to Graves' disease. Loss of libido and decreased potency were present in 71% and 56%, respectively. All patients had normal testicular volume (25 ml in all) and gynecomastia was detected in two of seven patients. Total sperm counts were less than 40 million in four of the five men tested. There was an inverse correlation between basal serum 17 beta-estradiol (E2) levels and total sperm count (r = -0.87; P less than 0.05). Mean (+/- SE) total testosterone (T) and E2 levels (1008 +/- 104 ng/100 ml and 104 +/- 16 pg/ml) were significantly higher than in normal men (P less than 0.05). Free T (13.6 +/- 2.4 ng/100 ml) was indistinguishable from normal (15.3 +/- 1.5 ng/100 ml). The mean (+/- SE) response of serum T to hCG administration was blunted (80 +/- 40%) compared to controls (193 +/- 19%; P less than 0.02). Basal plasma LH levels (15.5 +/- 1.5 mIU/ml) were significantly higher (P less than 0.05) than in normal men (9.1 +/- 0.6 mIU/ml) and hyperresponded to 100 microgram LRH iv in five of seven patients. Basal plasma FSH levels and the FSH response to LRH were normal. These results suggest that men with hyperthyroidism have 1) partial Leydig cell failure, 2) impairment of spermatogenesis, and 3) blunting of the feedback effects of E2.

Adult↗