Growth factors and goitrogenesis. (1/220)

By combining data from studies of multinodular non-toxic goitre (MNTG) with data from rat models of goitre induction and in vitro models, a map of the growth factors involved in goitrogenesis has been constructed. We have addressed the roles of the insulin-like growth factors, transforming growth factors, fibroblast growth factors, endothelins, etc. We hypothesise that an imbalance in the interactions between the various growth factor axes exists in MNTG which favours cell replication. Thyrotrophin, although not significantly elevated in MNTG, exerts critical effects through interactions with autocrine and paracrine factors and their receptors. Expansion of the thyroidal vascular bed through angiogenesis is closely co-ordinated with follicular cell expansion and folliculoneogenesis, and while the integrated paracrine actions of fibroblast growth factors, vascular endothelial growth factor and endothelin probably play central roles, additional, as yet elusive, factors are probably involved. The combination of in vitro and in vivo approaches, designed to address specific questions, will undoubtedly continue to prove invaluable in dissecting further the complex interactions that exist between these growth factors, their binding proteins and receptors in goitrogenesis.  (+info)

A new rapid technique for the fixation of thyroid gland surgical specimens. (2/220)

One of the main diagnostic problems in thyroid pathology is to distinguish between follicular adenoma and follicular carcinoma. Thorough sampling of the nodule's capsule is recommended in order to identify capsular invasion. However, during the hardening of the tissue, by the usual fixatives the capsule shrinks and rolls downwards and sometimes the capsule separates from the remaining tissue. The present work evaluates the use of "Lymph Node Revealing Solution" (LNRS) for the rapid fixation (2h) of different thyroid lesions as compared to that of formalin. Fifty-one unselected consecutive cases of thyroid nodules, which included various benign and malignant lesions, were examined. Each specimen was cut in two equal parts; one was fixed in LNRS, the other in formalin. Fixation in LNRS for 2 hours gave adequate results in sectioning and staining of the tissue, and excellent immunostains. Its advantage over formalin is the conservation of the natural relationship between the capsule and the rest of the tissue, on the same plane, as well as the short time required for the final diagnosis.  (+info)

Tissue inhibitor of metalloproteinases-1 (TIMP-1) mRNA is elevated in advanced stages of thyroid carcinoma. (3/220)

Tumour cell invasion and metastasis is a multistep process that involves the degradation of extracellular matrix proteins by matrix metalloproteinases (MMPs). Tissue inhibitors of metalloproteinases (TIMPs) act as negative regulators of MMPs and thus prevent tumour cell invasion and metastasis by preserving extracellular matrix (ECM) integrity. In the present study we examined the expression of one member of TIMPs, TIMP-1, in 39 thyroid tumour specimens and two thyroid carcinoma cell lines (NPA and SW579). We also investigated the effect of high TIMP-1 expression on the invasive potential of NPA cells. Northern blot analysis showed that TIMP-1 mRNA levels correlated directly with tumour aggressiveness: the highest number of TIMP-1 transcripts was found in stages III and IV vs benign goitre (P < 0.0001). However, TIMP-1 expression was not increased in NPA and SW579 cells, both of which are derived from poorly differentiated thyroid tumours. Immunohistochemical study showed strong TIMP-1 staining in the stroma cells of advanced stages of carcinomas. Overexpression of TIMP-1 by gene transfer resulted in a significant suppression of the malignant phenotype of NPA cells as judged by an in vitro tumour invasion assay. These results suggest that high levels of TIMP-1 transcripts in advanced stages of thyroid carcinoma likely come from stroma rather than thyroid cancer cells, and TIMP-1 may function as a thyroid tumour invasion/metastasis suppressor.  (+info)

Nocardia thyroiditis: unusual location of infection. (4/220)

Nocardia asteroides complex is an important opportunistic agent in immunocompromised hosts. Usually, primary pulmonary infection occurs and is followed by dissemination of the pathogen to the central nervous system and soft tissues. As described in the literature, almost every organ can be infected, but to our knowledge, Nocardia has been described as a pathogen responsible for thyroid abscess in only one report, which was published in 1993. The present report is the second case report of Nocardia thyroiditis. The patient was under immunosuppressor treatment following a combined liver-kidney transplant and presented with a preexisting nodular goiter which was probably a predisposing factor to the start and development of the thyroid infection.  (+info)

A case of extraadrenal pheochromocytoma associated with adrenal cortical nodular hyperplasia and papillary thyroid carcinoma. (5/220)

A 64-year-old woman was admitted in November, 1996 for fluctuating blood pressure. There was multinodular goiter in her neck. High urine VMA and serum aldosterone were noted. Computed tomography showed an oval lesion in the left adrenal gland. Left adrenalectomy was performed and the pathology was proved to be adrenal cortical nodular hyperplasia. Fluctuating blood pressure and high urine VMA persisted after the operation. CT scan of the abdomen revealed a soft tissue mass in lower abdomen. The patient was admitted again in September, 1997. Laboratory examinations showed normal serum aldosterone, normal plasma renin activity and high urine VMA. Aspiration cytology of the thyroid gland disclosed papillary thyroid carcinoma. [131I]-metaiodobenzylguanidine image revealed a high uptake lesion in the right L-3 paravertebral area. Tumor excision and thyroidectomy were performed. The pathology was reported as extraadrenal pheochromocytoma and papillary thyroid carcinoma. Papillary thyroid carcinoma is rarely associated with pheochromocytoma. To our knowledge, this paper is the first report of a patient with extraadrenal pheochromocytoma associated with papillary thyroid carcinoma and adrenal cortical nodular hyperplasia.  (+info)

Suppressive therapy with levothyroxine for euthyroid diffuse and nodular goiter. (6/220)

In this study, 35 patients with euthyroid diffuse goiter and 35 patients with euthyroid nodular goiter were treated with Levothyroxine (L-T4) for six months. The aim was to evaluate the efficacy of treatment on thyroid and nodule volumes and to evaluate the correlation between volume changes and thyroglobulin levels. Serum thyroid hormones, TSH, thyroglobulin, thyroid and nodule volumes were measured at the initial visit and after 6 months. Radioactive iodine uptakes of the thyroid gland were evaluated before treatment. The mean decrease of thyroid volume at six months was about 20% (20.4 +/- 8.8 ml vs. 16 +/- 7.9 ml, P<0.001) in patients with diffuse goiter. All patients with diffuse goiter showed some decrement in their goiter sizes. Thyroid nodules, in response to thyroid hormone treatment, showed a variable behavior. A reduction of 50% or more in volume was detected in 31% (11/35) of the patients. 54% of the patients (19/35) showed a 10-49% decrease in nodule volume. Five of the patients were found to be insensitive to the therapy. Their nodule volumes either increased or did not change during therapy. Free T4 and free T3 levels increased and TSH levels decreased with L-T4 treatment in all patient groups. Patients with higher TSH levels (within normal limits) showed more volume reduction in the diffuse goiter group. No uniform correlation was found between volume changes and thyroglobulin levels in either of the patient groups. In conclusion, suppressive thyroxine treatment is effective in reducing the size of the goiter, and nodules and thyroglobulin levels cannot be taken as an indicator of the efficacy of L-T4 therapy.  (+info)

Power Doppler ultrasonographic assistance in percutaneous ethanol injection of autonomously functioning thyroid nodules. (7/220)

The purpose of this study was to explore the potential role of power Doppler sonography in guiding percutaneous ethanol injection of autonomously functioning thyroid nodules. Thirty-two patients with pretoxic adenoma and 15 with toxic adenoma underwent percutaneous ethanol injection under power Doppler sonographic guidance. All patients with pretoxic adenoma and 13 of 15 patients with toxic adenoma were treated successfully (normalization of circulating thyroid hormones and thyroid stimulating hormone levels and disappearance of nodular hyperactivity with complete recovery of extranodular tracer uptake at scintigraphy). Power Doppler sonography showed the progressive reduction of the intranodular blood flow until its extinction after 6 to 12 months. Nodular shrinkage was obtained in all patients (from 10.85 +/-1.04 to 2.9 +/- 0.3 ml in pretoxic adenoma and from 15.4 +/- 1.8 to 4.2 +/- 0.7 ml in toxic adenoma. Power Doppler sonographic guidance seems to improve the outcome of percutaneous ethanol injection, allowing detection of blood flow even in very small vessels, permitting the ethanol to be guided toward the main afferent vessels of the nodules, and making it possible to monitor the diffusion and the effects of ethanol on nodular vascularization.  (+info)

Psychoses associated with thyrotoxicosis - 'thyrotoxic psychosis.' A report of 18 cases, with statistical analysis of incidence. (8/220)

OBJECTIVE: To report a series of newly diagnosed thyrotoxic patients with concurrent acute psychosis, and to assess the association between the two disorders. DESIGN: Retrospective study of thyrotoxic patients with associated psychosis ('thyrotoxic psychosis'; TP) requiring inpatient psychiatric care. New Zealand thyrotoxicosis annual incidence figures and first psychiatric admission rates for affective psychosis were utilised to statistically assess the co-occurrence of thyrotoxicosis and affective psychosis. PATIENTS AND METHODS: During the 20-year study period, 18 inpatients (16 women and 2 men), mean age 54 years, with TP were identified. No patient had a past history of thyrotoxicosis, but four had required psychiatric inpatient care many years earlier. Thyrotoxicosis was documented by radioimmunoassay of thyroid hormone levels, and thyroid scintiscan. Psychiatric manifestations were classified using ICD9 criteria. RESULTS: Thyroid hormone levels were markedly elevated in more than half of our TP patients. All younger patients had Graves' disease, and most older patients toxic nodular goitre. All patients were treated with antithyroid drugs, and all but one subsequently received (131)I therapy. Two patients were not mentally ill when thyrotoxicosis was diagnosed, but suffered major mood swings when thyroid hormone levels were falling. There was no specific psychiatric clinical picture but affective psychoses were commonest - seven depression, seven mania. The other diagnoses were two schizophreniform, one paranoid, and one delirium. Initially, neuroleptic medication was used in all but one patient, and during long-term follow-up (median 11 years) more than half our series had remained well with no further psychiatric problems. Statistical analysis was restricted to thyrotoxic patients with first psychiatric hospital admission for affective psychosis. During the 20-year period, there were nine thyrotoxic patients (95% confidence interval 4.5-17.1) with concurrent affective psychosis requiring first admission, and the calculated expected number was only 0.36. These findings indicate a clear association well above chance co-occurrence. CONCLUSION: TP is not a specific clinical picture, but affective psychoses are commonest. Statistical analysis of thyrotoxic patients with concurrent affective psychoses showed an incidence well above chance co-occurrence. It appears that thyrotoxicosis may be a precipitant of acute affective psychosis.  (+info)