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R Rajatanavin

Publications and source records attributed to R Rajatanavin.

At least 19 recordsLinked to original sources
PubMed1992

Systematic inclusion of clinical and laboratory data improves diagnostic accuracy of fine-needle aspiration biopsy in solitary thyroid nodules.

In this study, we identified clinical and laboratory markers of malignant thyroid nodules and determined whether systematic inclusion of these data could improve diagnostic accuracy of fine-needle aspiration biopsy in solitary thyroid nodules. The patients were 24 men and 105 women who underwent surgical removal of solitary thyroid nodules and had adequate fine-needle aspiration biopsy performed prior to surgery. Including fine-needle aspiration biopsy's diagnosis of suspected of malignancy in the same category as malignancy, the sensitivity and specificity of fine-needle aspiration biopsy were 71.4% and 85.1%, respectively, with an accuracy of 82.2%. Using stepwise linear regression analysis, clinical data, i.e. increasing age, irregular nodule surface, hard consistency of nodule, and high serum thyroglobulin concentration, were associated with an increased risk of malignancy when the cytological result was excluded. When cytology was also considered, male sex, irregular nodule surface and high serum thyroglobulin concentration were found to be associated with an increased risk of malignancy. The diagnostic value of clinical data alone, even in combination with cytology or laboratory data, was inferior to that of fine-needle aspiration biopsy alone. The specificity and accuracy of fine-needle aspiration biopsy could be increased to 98.0% and 90.7%, respectively, whereas its sensitivity was decreased to 64.3% when these variables were considered in combination. Therefore, of fine-needle aspiration biopsy, clinical and laboratory data, fine-needle aspiration biopsy alone has the highest diagnostic value, which can be increased only when both clinical characteristics and serum thyroglobulin concentration are systematically included.

Adult↗
PubMed1992

Diabetes insipidus: another cause of hormonal hyperthermia.

Diabetes insipidus is not generally recognized as a possible cause of etiologically obscure fever. We describe a female patient who presented with fever and polyuria and was shown to have idiopathic partial neurogenic diabetes insipidus. The fever was subsequently demonstrated to be caused by diabetes insipidus per se. The mechanism for the production of fever in this patient was most likely a defect in peripheral heat dissipation secondary to inadequate hydration. We conclude that diabetes insipidus is another cause of hormonal hyperthermia and should be considered in the differential diagnosis of etiologically obscure fever.

Adolescent↗
PubMed1991

Variable prevalence of lymphocytic thyroiditis among diabetes-prone sublines of BB/W or rats.

The BB/Wor rat develops spontaneous autoimmune insulin-dependent diabetes mellitus (DM) and lymphocytic thyroiditis (LT). Six different inbred sublines of this rat model have been selected for studying the pathogenesis of DM and, thereby, the prevalence of DM has been carefully monitored and found to be relatively constant. In contrast, we have observed a striking difference in the prevalence and intensity of LT in these six sublines, varying from 100% in NB subline rats to 4.9% in BE subline rats at 105-110 days of age. Excess iodide administration frequently increases the prevalence of LT but did not do so in the two sublines (BB and BE) with the lowest frequency of spontaneous LT. In view of this variable prevalence of LT in the different BB/Wor sublines, it is imperative that investigators studying the pathogenesis and modulation of LT in this rat model select those sublines which express a desired frequency of spontaneous LT.

Aging↗
PubMed1990

The effect of amiodarone on the control of hyperthyroidism by propylthiouracil.

We studied the efficacy of amiodarone (800, 600, 400 and 200 mg orally daily during weeks 1, 2, 3 and 4, respectively) plus propylthiouracil (PTU, 100 mg orally every 8 h) in comparison to PTU alone in the early treatment (28 days) of Graves' disease patients. Circulating T3 and T4 decreased earlier and more markedly in the amiodarone plus PTU-treated group. An initial rise of circulating rT3 above the base-line value followed by a gradual decline was observed in the former group while only a decline below the base-line values was observed in the latter group. The resting pulse rate decreased and body weight increased significantly in the amiodarone plus PTU-treated group. In the PTU-treated group, significant weight gain was observed later in the course of treatment while no significant reduction in pulse rate was observed. No major side-effects of amiodarone were observed during the course of treatment. This study suggested that the combination of amiodarone and PTU was more efficacious than PTU alone in reducing circulating T3, T4 and clinical hyperthyroidism early in the course of treatment of patients with Graves' disease. This regimen has an additional potential advantage because of the antiarrhythmic property of amiodarone, especially in situations when a beta-blocker is contraindicated.

Adult↗
PubMed1990

Postpartum thyroid dysfunction in Bangkok: a geographical variation in the prevalence.

To determine the prevalence of thyroid dysfunction in Thai postpartum women, we evaluated thyroid function and thyroid autoantibodies in 812 consecutive unselected women at 1.5 months post partum. At 3.5 months post partum 570 women without previous thyroid abnormality returned for a second set of thyroid function test. The prevalence of thyroid dysfunction was 1.1%, which was less than that reported from other countries. Various types of postpartum thyroid dysfunction, namely, transient thyrotoxicosis followed by transient hypothyroidism, transient thyrotoxicosis or hypothyroidism occurring alone or permanent hypothyroidism were encountered. Eight out of 9 patients with thyroid dysfunction had thyroid autoantibodies. Fine needle aspiration biopsy of the thyroid was done in 4 patients and all showed lymphocytic thyroiditis. Even though Bangkok is an iodine surfeit area, iodine intake is relatively lower than in other areas where the prevalence of postpartum thyroid dysfunction is much higher. The discrepancy in geographic prevalence of postpartum thyroid dysfunction may result from the interaction of immunogenetic heterogeneity of different ethnic background, environmental iodine intake, and other unidentified environmental factors.

Adult↗
PubMed1990

Comparison of basal serum TSH concentration by immunoradiometric assay and TRH stimulation test in the diagnosis of thyroid dysfunction.

The mean basal serum TSH (IRMA) concentrations and their increments after exogenous TRH stimulation in euthyroid subjects and patients with borderline and definite hypo or hyperthyroidism were reported. In euthyroid subjects, the increment of serum TSH (IRMA) after TRH stimulation was higher in females than in males. The measurement of basal serum TSH (IRMA) alone could discriminate euthyroid subjects from patients with thyroid dysfunction. Significant correlation between basal serum TSH (IRMA) concentrations and their corresponding increment of serum TSH (IRMA) at 30 minute after TRH stimulation in the whole group of patients was observed. Therefore, the measurement of basal serum TSH (IRMA) concentration had sufficient discriminatory value in differentiating patients with or without thyroid dysfunction and obviating the need to perform TRH stimulation test.

Adult↗
PubMed1989

Thyroid hormone antibodies and Hashimoto's thyroiditis in mongrel dogs.

Abnormally elevated serum T3 concentrations measured by RIA were observed in 19 clinically euthyroid or hypothyroid mongrel dogs. The serum T4 concentrations in these sera were low, normal, or high. Measurement of the intensity of thyroid hormone binding to serum proteins was determined by equilibrium dialysis. A marked decrease in the percent free T3 was observed in these abnormal sera. Polyacrylamide gel electrophoresis, pH 7.4, of normal dog serum enriched with tracer 125I-labeled thyroid hormones demonstrated binding of [125I]T4 to transthyretin, thyroid hormone-binding globulin, and albumin and of [125I]T3 primarily to thyroid hormone-binding globulin. In all abnormal sera, polyacrylamide gel electrophoresis demonstrated strikingly higher binding of T3 to immunoglobulin (Ig). Eleven of 16 abnormal sera had minimal to moderate binding of T4 to Ig. The percent free T4 was lower only in dogs whose sera demonstrated markedly increased binding of T4 to Ig. All abnormal sera tested had positive antithyroglobulin antibodies, consistent with the diagnosis of autoimmune lymphocytic thyroiditis. As in humans, antibodies to thyroid hormones in dogs are more common in the presence of Hashimoto's thyroiditis and should be considered when elevated serum thyroid hormone concentrations are observed in the absence of clinical thyrotoxicosis. When an antibody to only one thyroid hormone is present, a marked discrepancy in the serum concentrations of T3 and T4 will be observed.

Animals↗
PubMed1989

Salient clinical features of Sheehan's syndrome.

The natural history of Sheehan's syndrome is chronic. There is a long delay between peripartum hemorrhage and diagnosis. The majority of patients delivered at home and resided in rural areas where modern obstetric care was not readily attainable. The syndrome should be suspected in patients who present with asthenia-weakness, adrenal crisis and secondary amenorrhea. The symptoms that the patients usually had were secondary amenorrhea, asthenia-weakness, loss of axillary and pubic hair and failure to lactate. The important physical signs were loss of pubic and axillary hair, dry skin, slow relaxation phase of deep tendon reflex, hypopigmented areolar and pallor. The common laboratory features of the patients were anemia, eosinophilia, hypoalbuminemia, elevation of serum SGOT but not SGPT, hyponatremia and low fasting plasma glucose.

Adolescent↗
PubMed1987

A four generation study of familial dysalbuminemic hyperthyroxinemia: diagnosis in the presence of an acquired excess of thyroxine-binding globulin.

We have studied the largest kindred with familial dysalbuminemic hyperthyroxinemia (FDH) thus far reported, comprising thirty-three blood relations in four generations and three of their spouses. Our objective was to complement previous evidence concerning the precise mode of inheritance of FDH and to detect any other features of the disorder that had not yet been noted. Among the thirty three, there were thirteen patients with FDH, eight males and five females, in all of whom the abnormality appeared to be fully expressed. Within the kindred, no affected female has borne a female child, but transmission from female to male, male to male, and male to female has been observed. Among the offspring of individuals with FDH, the overall observed frequency of FDH in three filial generations was 12/22, or 54.5 per cent, yielding a computed penetrance ratio of 1.09. Four of the patients with FDH had been investigated for hyperthyroidism, and two of them had mistakenly been treated. Of particular interest were two women with FDH who were receiving oral contraceptives and whose serum thyroxine-binding globulin (TBG) concentrations were increased. The results of their thyroid function tests differed from those of patients with FDH whose TBG concentrations were normal and mainly suggested the presence of only a high TBG state. The diagnosis of FDH in these two patients was obscured, and probably would not have been made were it not for the present investigation, which led to the electrophoretic demonstration of increased binding of T4 by serum albumin.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1986

The effect of methimazole on the development of spontaneous lymphocytic thyroiditis in the diabetes-prone BB/W rat.

UNLABELLED: Methimazole (MMI) administration decreases the incidence and intensity of experimentally induced lymphocytic thyroiditis (LT) in the female August rat and male A/J mouse. Spontaneous LT frequently occurs in the insulin-dependent type-I diabetic (DM) BB/W rat. Experiments were carried out to determine whether MMI administration to BB/W rats from 30 to 120 days of age would affect the incidence and intensity of spontaneous LT and the incidence of spontaneous DM. A total of 870 ng MMI/gm BW or saline (C) were administered ip daily to 77 BB/W rats beginning at age 30 days. Rats were killed at 120 days, blood obtained for measurement of serum T4, TSH, and anti-Tg Ab (ELISA), and thyroids removed for histology. MMI administration was associated with a decrease in the incidence of LT (31% vs. 55%; p less than 0.05) but no difference in the severity of the LT. Serum T4 was similar in the MMI and C groups, but serum TSH was slightly but significantly higher in MMI treated rats [43 +/- 6 (mean +/- SE) microU/ml vs. 30 +/- 2.5; p less than 0.05]. Serum anti-Tg Ab levels increased with age but MMI administration did not affect this rise. There was no significant difference in the incidence of insulin-dependent DM between the MMI and C rats (MMI, 56%; C, 74%). CONCLUSION: MMI administration to the genetically predisposed insulin-dependent diabetes and LT prone BB/W rat during the age when LT spontaneously occurs reduced the incidence of LT.

Animals↗
PubMed1986

Seasonal changes in serum thyroid hormone binding proteins in the woodchuck (Marmota monax).

To evaluate the role of serum T4- and T3-binding proteins in the elevation of serum T4 and T3 concentrations in the woodchuck in the fall and winter, blood was collected from woodchucks during the four seasons of the year (seasonal study) and from 2-week fasted woodchucks in the summer (fasting study) and the serum concentrations of total T4 and T3 were measured. The distribution of [125I]4 and [125I]T3 tracers among the serum binding proteins and the serum T4-binding globulin (TBG) binding capacity for T4 was determined by polyacrylamide gel electrophoresis. Plasma concentrations of both T4 and T3 were highest in the winter. The major T4-binding protein in the woodchuck is TBG. There was an increase in both [125I]T4 and [125I]T3 tracer binding to serum TBG in fall and winter, and TBG binding capacity for T4 was 2-fold higher in winter than in summer. There were increases in TBG binding and in the TBG T4 binding capacity in the 2-week starved animals. The increased binding of T4 and T3 by TBG in the fall and winter may be partially responsible for the increased serum concentrations of T4 and T3 in the fall and winter in the woodchuck, a time when secretion of T4 and T3 by the thyroid gland is very low. This may be facilitated by the low or absent food consumption at these times of the year.

Animals↗
PubMed1985

Fasting induces the generation of serum thyronine-binding globulin in Zucker rats.

Five-month-old lean and obese Zucker rats were fasted for up to 7 days (lean rats) or 28 days (obese rats), and serum total and free T4 and T3 concentrations, percent free T4 and T3 by equilibrium dialysis, and the binding of [125I] T4 to serum proteins by gel electrophoresis were measured. In the lean rats, a 4- or 7-day fast resulted in significant decreases in serum total and free T4 and T3 concentrations. There was a decrease in the percent free T3 after 7 days of starvation. In contrast, a 4- or 7-day fast did not alter any of these variables in the obese rats. However, after 14 or more days of starvation, serum total T4 and T3 concentrations increased, and the percent free T4 and T3 decreased, resulting in no change in the serum free T4 or T3 concentrations in the obese rats. The percent of [125I]T4 bound to serum thyronine-binding globulin increased and the percent bound to thyronine-binding prealbumin decreased with the duration of the fast in both the lean and obese rats. The increase in serum thyronine-binding globulin binding of T4 can explain the increase in serum total T4 and T3 concentrations, the decrease in percent free T4 and T3, and the normal free hormone concentration in the long term fasted obese rats. The findings in the lean rats appear to be due to a combination of the known central hypothyroidism that occurs during 4-7 days of fasting and the fasting-induced changes in T4 binding in serum. Changes in T4 and T3 binding in serum during fasting in the rat must be considered when the effects of fasting on serum concentrations of the thyroid hormones, thyroid hormone kinetics, and the peripheral action of the thyroid hormones are evaluated.

Animals↗
PubMed1985

Euthyroid hyperthyroxinemia and thyroxine-binding prealbumin excess in islet cell carcinoma.

This manuscript describes euthyroid hyperthyroxinemia secondary to elevated serum T4-binding prealbumin (TBPA) concentrations in a patient with islet cell carcinoma and reports serum TBPA measurements in other patients with islet cell carcinoma. A 73-yr-old man with a 17-yr history of metastatic islet cell carcinoma was found to have hyperthyroxinemia. His total serum T4 concentration was 18.5 micrograms/dl (normal, 5.5-11.5). Eight years previously, his serum T4 concentration was normal. His free T4 concentration, as determined by equilibrium dialysis, was 1.3 ng/dl (normal, 0.9-2.1). Serum T3, TSH, and T4-binding globulin (TBG) concentrations were normal, as was the TSH response to TRH administration. Polyacrylamide gel electrophoresis of the patient's serum in the presence of tracer amounts of [125I]T4 revealed that, compared to normal sera, [125I]T4 binding to TBPA was increased from 30.0 +/- 6.0% (mean +/- SD) to 52.0%. The distribution of [125I]T3 amont albumin, TBG, and TBPA was normal in this electrophoretic procedure. The concentration of TBPA in the patient's serum was 189 mg/dl. In contrast, the mean serum TBPA concentration in normal men was 40 +/- 4 (mean +/- SD) mg/dl, and that in normal women was 18 +/- 4 mg/dl. Sera from the patient's daughter, his brother, 2 sisters, and 2 male paternal cousins contained normal amounts of TBPA, ranging from 34-47 mg/dl in his male relatives and from 26-30 mg/dl in his female relatives. Serum free T4 index determinations in his relatives also were normal. Serum TBPA concentrations were determined in 14 additional patients with islet cell carcinoma. In 1 of these patients, a man with an insulinoma, serum TBPA was elevated (66 mg/dl). This patient's serum T4 level was 7.3 micrograms/dl, and his free T4 index was 7.0. These data and another study suggest that islet cell carcinoma may rarely produce a TBPA-like protein resulting in an elevated serum TBPA concentration. Markedly elevated serum TBPA is associated with euthyroid hyperthyroxinemia.

Adenoma, Islet Cell↗
PubMed1985

Radiation-associated recurrent parathyroid adenoma.

Recurrent parathyroid adenoma occurred in a patient who had received radiation treatments to the lateral aspect of the pharynx for lymphoid hyperplasia at the age of 10 years. The interval between the development of the first and second adenomas was 20 years. Although an association between head and neck irradiation and primary hyperparathyroidism is known, we believe this to be the first report of recurrent hyperparathyroidism in an irradiated patient.

Adenoma↗