Causes of anorexia in untreated hyperthyroidism: a prospective study.
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Seventeen consecutive patients (mean (SD) 46 (11) years) with untreated hyperthyroidism and anorexia and 29 patients (35 (9) years) with untreated hyperthyroidism without anorexia were studied. The study was conducted at the thyroid clinic of the PUMC Hospital, Beijing, China from March to August 1997. The patients' ages, serum free calcium, liver function and emotional state, specifically the level of anxiety (using the self anxiety scale, Chinese version), were compared before and/or after antithyroid drug treatment in the two groups. This prospective study suggested that the causes of anorexia in untreated hyperthyroidism are complicated. Older age, abnormal liver function, and the level of anxiety are significantly related to anorexia in untreated hyperthyroidism, but hypercalcaemia was not confirmed to be related to anorexia in the study. (+info)
Neuromuscular findings in thyroid dysfunction: a prospective clinical and electrodiagnostic study.
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OBJECTIVES: To evaluate neuromuscular signs and symptoms in patients with newly diagnosed hypothyroidism and hyperthyroidism. METHODS: A prospective cohort study was performed in adult patients with newly diagnosed thyroid dysfunction. Patients were evaluated clinically with hand held dynamometry and with electrodiagnosis. The clinical features of weakness and sensory signs and the biochemical data were evaluated during treatment. RESULTS: In hypothyroid patients 79% had neuromuscular complaints, 38% had clinical weakness (manual muscle strength testing) in one or more muscle groups, 42% had signs of sensorimotor axonal neuropathy, and 29% had carpal tunnel syndrome. Serum creatine kinase did not correlate with weakness. After 1 year of treatment 13% of the patients still had weakness. In hyperthyroid patients 67% had neuromuscular symptoms, 62% had clinical weakness in at least one muscle group that correlated with FT4 concentrations, but not with serum CK. Nineteen per cent of the patients had sensory-motor axonal neuropathy and 0% had carpal tunnel syndrome. The neuromuscular signs developed rapidly, early in the course of the disorder and were severe, but resolved rapidly and completely during treatment (average time 3.6 months). CONCLUSIONS: Neuromuscular symptoms and signs were present in most patients. About 40% of the hypothyroid patients and 20% of the hyperthyroid patients had predominantly sensory signs of a sensorimotor axonal neuropathy early in the course of thyroid disease. Weakness in hyperthyroidism evolved rapidly at an early stage of the disorder and resolved completely during treatment, suggesting a functional muscle disorder. Hand held dynamometry is sensitive for the detection of weakness and for the clinical evaluation of treatment effects. Weakness in hypothyroidism is more difficult to treat, suggesting myopathy. (+info)
Neural and hormonal control of expression of myogenic regulatory factor genes during regeneration of Xenopus fast muscles: myogenin and MRF4 mRNA accumulation are neurally regulated oppositely.
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With the aim to investigate the influence of both innervation and thyroid hormone, on the expression of the MRFs during muscle regeneration, we performed cardiotoxin injury-induced regeneration experiments on fast muscles of adult Xenopus laevis subjected to different experimental conditions, including denervation and T3 treatment, and analyzed the accumulation of the four myogenic regulatory factors (MRFs) using RT-PCR and in situ hybridization. We show here that manipulation of hormone levels or innervation resulted in differential alterations of MRF expression. Denervation and T3 treatment transiently down-regulated Myf-5 mRNA levels at the beginning of the regeneration process. Myf-5 was the only myogenic factor subject to thyroid hormone influence. Muscle denervation persistently reduces the levels of MRF4 transcripts as early as the first stages of regeneration, whereas the levels of myogenin mRNA were increased in the late stages of regeneration. This suggests that MRF4 expression may be induced by innervation and hence may be involved in mediating transcriptional responses to innervation and that myogenin expression may compensate for the down-regulation of MRF4 gene. This switch in MRF gene expression following denervation could have important consequences for the ability of Xenopus regenerating muscles to recover function after denervation. (+info)
Tissue-specific regulation of thyroid hormone receptor mRNA isoforms and target gene proteins in domestic ducks.
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Skeletal muscles are important target tissues for thyroid hormone action. The present study examines the influence of thyroid status on muscle growth and tissue-specific expression of thyroid receptor (TR) mRNA isoforms in a commercial strain of the domestic duck (Anas platyrhynchos). Four groups (n=5) of 1-week-old ducklings were rendered either hypothyroid by treatment with methimazole (6 mg 100 g(-1) body mass or 12 mg 100 g(-1) body mass), or hyperthyroid by treatment with methimazole (6 mg 100 g(-1) body mass) in combination with thyroid hormones (5 microg thyroxine (T(4)) and tri-iodothyronine (T(3)) 100 g(-1) body mass or 10 microg T(4) and T(3) 100 g(-1) body mass). Serum and tissue samples (cardiac, pectoralis and semimembranosus leg muscle, liver, pituitary and cerebral cortex) were collected from these four groups, and from a group of untreated controls, at 8 weeks of age. Development of duckling morphology was retarded in methimazole-treated birds compared with that in euthyroid controls, as evidenced by differences in skeletal dimensions, primary feather length, and body and muscle masses. Body mass was lower by 18%, and relative masses of cardiac and pectoralis muscles were lower by 28% and 32% respectively. Heterologous oligonucleotides for TR alpha, TR beta 0, TR beta2 and the housekeeping gene beta-actin were derived from chicken sequences. RT-PCR showed that TR alpha mRNA was expressed in all tissues but was not significantly affected by any of the experimental treatments. TR beta 0 mRNA expression was significantly lower in the leg muscles of ducklings treated with 12 mg methimazole 100 g(-1) body mass (0.109+/-0.047 TR:beta-actin ratio, P<0.05) compared with that in euthyroid controls (0.380+/-0.202), but was unaltered in the pectoralis and cardiac muscles. Expression of TR beta 0 mRNA was significantly higher in pectoralis (by 3.5-fold, P<0. 05), cardiac (by 4.2-fold, P=0.003) and leg (by 4.0-fold, P<0.001) muscles of ducklings treated with thyroid hormones compared with those in euthyroid controls (0.098+/-0.019, 0.822+/-0.297 and 0. 38+/-0.202 TR:beta-actin respectively). Only the pituitary gland expressed significant levels of TR beta 2 mRNA. (+info)
Lymphocyte populations in peripheral blood in hyperthyroid and euthyroid subjects.
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Thymus-derived and non-thymus-derived peripheral blood lymphocytes were examined by means of E- and EAC-rosette tests. The frequency of these lymphocyte populations was the same in hyperthyroid and euthyroid individuals. It was also demonstrated that PHA responsiveness of lymphocytes from hyperthyroid patients was equal to that of lymphocytes from euthyroid controls and did not change after treatment with 131I. (+info)
Hyperthyroidism presenting as dysphagia.
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A 65-year-old man presented with hyperthyroidism associated with thyrotoxic dysphagia. Treatment with thiamazole improved his symptoms promptly. Although dysphagia is a rare manifestation of thyrotoxicosis, it should be emphasized that the possibility of hyperthyroidism must be discussed in unexplained dysphagia because it is readily treatable. (+info)
Thyroid cancer prevalence after radioiodine treatment of hyperthyroidism.
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The definitive treatment of hyperthyroidism in Europe is quite different from that in the United States. In Europe, the surgical approach is often preferred and considered safer than radioiodine treatment. European doctors usually prefer to surgically remove the thyroid and perform a pathologic examination of it. They consider it to be an essential diagnostic tool to identify possible diseases that might be associated with hyperthyroidism and even to detect the rare thyroid tumors that might be associated with thyroid hyperfunction. The aim of this study was to evaluate whether radioiodine therapy could be a risk factor for the misdiagnosis of thyroid cancer. METHODS: We performed a retrospective revision of data we collected from 6647 patients (1171 [17.5%] men, 5476 [82.5%] women), all of whom underwent 1311 therapy for hyperthyroidism from 1970 to 1997. Of the whole group, 6.5% were younger than 40 y, 33.5% were 40-60 y old, and 60% were older than 60 y. Moreover, 5061 (76%) patients had either an autonomously functioning node or a toxic multinodular goiter. The other 1586 (24%) patients had Graves' disease. RESULTS: After treatment, thyroid cancer was discovered in 10 (0.15%) patients, none of whom belonged to the group of patients with Graves' disease. Five of these patients were treated during a period from 1970 to 1980, when sonography was not routinely available. The incidence of thyroid cancer in the series of radioiodine-treated patients (150/100,000 over a 27-y period) was not significantly different from its incidence in the general population. The expected rate is 124.88 per 100,000 over a 27-y period. CONCLUSION: An accurate preliminary evaluation (clinical examination, sonography, and cytologic evaluation of fine-needle aspiration) is fundamental for a proper choice between radioiodine and surgical therapy. (+info)
Multicolour FISH detection of radioactive iodine-induced 17cen-p53 chromosomal breakage in buccal cells from therapeutically exposed patients.
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Simultaneous labelling of 17cen and the p53 locus by multicolour FISH was used to monitor radioactive iodine-induced structural and numerical chromosome abnormalities in buccal cells from 29 hyperthyroidism and thyroid cancer patients sampled before and after therapeutic treatment. This novel methodology allowed the efficient detection of 17p deletions leading to p53 allelic deletions, 17p gains and whole chromosome 17 numerical abnormalities in epithelial cells. Highly significant increases in the frequency of cells with (i) 17p abnormalities (1.8-fold; P < 0.001), including p53 monoallelic deletions (2.1-fold; P < 0.001) and 17p gains (3.5-fold; P < 0.001); (ii) chromosome 17 numerical abnormalities (2-fold; P < 0.001); and (iii) simultaneous 17p breakage and chromosome 17 numerical abnormalities (2.3-fold; P < 0.001), were observed after radioactive iodine treatment. As expected, the major contribution to these increases was detected in hyperthyroidism patients compared with thyroid cancer patients who suffered thyroidectomy before radioactive iodine exposure and, therefore, experienced a rapid elimination of the radioisotope. Considering that both the genetic endpoints and the target tissue are extremely relevant in carcinogenesis, it is suggested that the observed genetic damage could contribute to the reported increase in cancer risk of people therapeutically or accidentally exposed to radioactive iodine. (+info)