The epizootiology and pathogenesis of thyroid hyperplasia in coho salmon (Oncorhynchus kisutch) in Lake Ontario.
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The thyroid glands of coho salmon collected at different stages of their anadromous migration exhibited progressive and extensive hyperplasia and hypertrophy. The incidence of overt nodule formation rose from 5% in fish collected in August to 24% in fish collected in October. The histological picture of the goiters was similar to that found in thiourea-treated teleosts and thiouracil-treated mammals. There was a concomitant, significant decrease in serum thyroxine and triiodothyronine values between September and October (thyroxine, 1.0+/-0.3 mug/100 ml and 0.4 mug/100 ml in September and October, respectively; triiodothyronine, 400.3+/-51.6 ng/100 ml and 80.2 ng/100 ml in September and October, respectively) and marked hypertrophy and hyperplasia of thyrotrophs. These data indicate a progressive hypothyroid condition which, although it may be linked to iodide deficiency, may well be enhanced by other environmental factors. The evidence for involvement of other factors is discussed. (+info)
Measurement of serum TSH in the investigation of patients presenting with thyroid enlargement.
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In otherwise euthyroid patients presenting with thyroid enlargement, reduction in serum thyrotrophin (TSH) concentrations measured in a sensitive assay may be a marker of thyroid autonomy and may therefore indicate a benign underlying pathology. We investigated prospectively a cohort of 467 subjects presenting consecutively to our thyroid clinic with nodular or diffuse enlargement of the thyroid. Subjects were divided into those with normal (0.4-5.5 mU/l), low but detectable (0.1-0.39 mU/l) or undetectable (< 0.1 mU/l) serum TSH concentrations. The final pathological diagnosis was defined by fine-needle aspiration cytology and clinical follow-up of at least 2 years or by fine-needle aspiration cytology and histology following surgical treatment. Serum TSH concentrations below normal were found in 75 patients (16.1%), those with low serum TSH results having higher mean free T4 concentrations, were older and were more likely to be female. In those with undetectable serum TSH, no patient had a diagnosis of thyroid neoplasia and in those with low but detectable TSH, thyroid neoplasms were diagnosed in two patients (3.4%). In those with normal serum TSH, 12.0% had a final diagnosis of thyroid neoplasm (p = 0.013). Overall, thyroid malignancy was found in one patient (1.3%) of those with a serum TSH measurement below the normal range and 6.9% of those with normal serum TSH (p < 0.06). Reduction in serum TSH at presentation may identify a group which requires less intensive investigation and follow-up than those without biochemical evidence of thyroid autonomy. (+info)
Development of a thyroid function strategy for general practice.
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A study was carried out to investigate a thyroid stimulating hormone (TSH) frontline strategy that could potentially result in a more straightforward interpretation of thyroid function tests, a reduction in the number of inappropriate referrals to medical outpatients, an improvement in the 'turnaround time' of results, and a reduction in the number of unnecessary tests carried out, thereby reducing costs. (+info)
Autoimmunity resulting from cytokine treatment predicts long-term survival in patients with metastatic renal cell cancer.
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PURPOSE: In patients undergoing cytokine therapy, systemically applied interleukin-2 (IL-2) and/or interferon-alpha (IFN-alpha) have been reported to induce thyroid dysfunction as well as thyroid autoantibodies. We analyzed the correlation of thyroid autoimmunity with HLA phenotype, various other autoimmune parameters, and patient survival. PATIENTS AND METHODS: For this purpose, antithyroglobulin autoantibodies, antimicrosomal thyroid autoantibodies, thyroglobulin receptor autoantibodies, thyroid dysfunction, and multiple clinical parameters were determined in 329 unselected patients with metastatic renal cell cancer before and after systemic IL-2 and IFN-alpha2 therapy. For statistical analysis, we used both univariate and multivariate Cox proportional hazards models and the two-tailed Fisher's exact test. RESULTS: Antithyroglobulin autoantibodies and antimicrosomal thyroid autoantibodies were detected in 60 patients (18%); positive autoantibody titers of various other autoimmune parameters were statistically unrelated. The presence of thyroid autoantibodies was correlated with prolonged survival (P<.0001). There was a statistically significant difference in frequencies of HLA-Cw7 expression between thyroid autoantibody-positive and -negative patients (P< or =.05), and the Cw7 expression was associated with prolonged overall survival (P = .009). CONCLUSION: The evaluation of thyroid autoantibodies during cytokine therapy could be a useful prognostic marker for patients with renal cell carcinoma who benefit from cytokine treatment. IL-2- and IFN-alpha2-induced tumor control and prolonged survival may require breaking of immunologic tolerance against self-antigens. (+info)
Clinical presentation and early course of type 1 diabetes in patients with and without thyroid autoimmunity.
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OBJECTIVE: To evaluate the prevalence of thyroid autoimmunity (TAI) in patients with recent-onset type 1 diabetes and to determine the influence of TAI on the clinical presentation and evolution of type 1 diabetes. RESEARCH DESIGN AND METHODS: We studied 111 newly diagnosed type 1 diabetes patients > 13 years old. The diagnosis of TAI was based on medical history and measurement of thyroid peroxidase (microsomal) antibodies (TPOAs). Clinical presentation of diabetes, beta-cell autoimmune markers (GADAs and 1A2As), and evolution of insulin-secretory reserves and metabolic control during the first 2 years of follow-up were analyzed. Differences between groups were evaluated by Student's t test or the chi 2 test. The influence of TAI on follow-up data was evaluated by multiple logistic regression analysis. RESULTS: TAI was present in 31 patients (14 TPOA+ patients with normal thyroid function, 12 TPOA+ patients with thyroid dysfunction, and 5 patients with previously diagnosed TAI). TAI was more prevalent in women than in men (43.7 vs. 15.9%, P = 0.001). beta-Cell autoimmunity was more prevalent in patients with TAI than in those without TAI (93.5 vs. 76.3%, P = 0.03). The evolution of insulin requirements, metabolic control, and insulin-secretory reserves was comparable in the two groups. CONCLUSIONS: TAI is present in many type 1 diabetes patients at the time of diagnosis and is associated with a high prevalence of thyroid dysfunction. The clinical presentation of diabetes and the evolution of metabolic control and insulin-secretory reserves are not influenced by the presence of TAI. Patients with type 1 diabetes should be screened for TAI at diagnosis. (+info)
Thyroid disease in pregnancy.
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This review article provides a broad overview of thyroid disease and pregnancy. (+info)
Thyroid vascularity and blood flow are not dependent on serum thyroid hormone levels: studies in vivo by color flow doppler sonography.
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OBJECTIVE: Thyroid blood flow is greatly enhanced in untreated Graves' disease, but it is not known whether it is due to thyroid hormone excess or to thyroid hyperstimulation by TSH-receptor antibody. To address this issue in vivo patients with different thyroid disorders were submitted to color flow doppler sonography (CFDS). SUBJECTS AND METHODS: We investigated 24 normal subjects, and 78 patients with untreated hyperthyroidism (49 with Graves' hyperthyroidism, 24 with toxic adenoma, and 5 patients with TSH-secreting pituitary adenoma (TSHoma)), 19 patients with thyrotoxicosis (7 with thyrotoxicosis factitia, and 12 with subacute thyroiditis), 37 euthyroid patients with goitrous Hashimoto's thyroiditis, and 21 untreated hypothyroid patients with Hashimoto's thyroiditis. RESULTS: Normal subjects had CFDS pattern 0 (absent or minimal intraparenchimal spots) and mean intraparenchimal peak systolic velocity (PSV) of 4.8+/-1.2cm/s. Patients with spontaneous hyperthyroidism due to Graves' disease, TSHoma, and toxic adenoma had significantly increased PSV (P<0.0001, P=0.0004, P<0.0001 respectively vs controls) and CFDS pattern. Patients with Graves' disease had CFDS pattern II (mild increase of color flow doppler signal) in 10 (20%) and pattern III (marked increase) in 39 cases (80%). Mean PSV was 15+/-3cm/s. Patients with toxic adenoma had CFDS pattern I (presence of parenchymal blood flow with patchy uneven distribution) in 2 (8%), pattern II in 16 (70%) and pattern III in 5 (22%). Mean PSV was 11+/-2.4cm/s. Patients with TSHoma showed CFDS pattern I in one case (20%) and pattern II in 4 (80%). Mean PSV was 14.8+/-4.2cm/s. Patients with thyrotoxicosis had normal PSV (4.2+/-1. 1cm/s in subacute thyroiditis, 4+/-0.8cm/s in thyrotoxicosis factitia, P=not significant vs controls) and CFDS pattern 0. Untreated euthyroid patients with goitrous Hashimoto's thyroiditis had CFDS pattern 0, and mean PSV (4.3+/-0.9cm/s; P=not significant vs controls). Untreated hypothyroid patients with goitrous Hashimoto's thyroiditis had CFDS pattern I in 14 cases (67%), pattern II in 4 (19%) and pattern 0 in 3 (14%) and mean PSV (5.6+/-1. 4cm/s) was higher than that of controls (P=0.026). CONCLUSIONS: An increase in both intrathyroidal vascularity and blood velocity was observed in patients with spontaneous hyperthyroidism but not in thyrotoxicosis due to either ingestion of thyroid hormones or to a thyroidal destructive process. The slightly increased vascularity and blood velocity observed in patients with hypothyroid Hashimoto's thyroiditis suggests that thyroid stimulation by either TSH-receptor antibody or TSH is responsible for the increased thyroid blood flow. (+info)
Identification of thyroid hormone residues on serum thyroglobulin: a clue to the source of circulating thyroglobulin in thyroid diseases.
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Thyroglobulin (Tg) present in the serum of normal individuals and patients with thyroid disorders could be partly newly synthesized non-iodinated Tg and partly Tg containing iodine and hormone residues originating from the lumen of thyroid follicles. With the aim of examining the contribution of the latter source of Tg to the elevation of serum Tg concentration in thyroid pathophysiological situations, we devised a procedure to identify thyroxine (T4) and tri-iodothyronine (T3) residues on Tg from unfractionated serum. A two-step method, basedon (i)adsorption of Tg on an immobilized anti-human Tg (hTg) monoclonal antibody (mAb) and (ii)recognition of hormone residues on adsorbed Tg by binding of radioiodinated anti-T4 mAb and anti-T3 mAb, was used to analyze serum Tg from patients with either Graves' disease (GD), subacute thyroiditis (ST) or metastatic differentiated thyroid cancer (DTC). Purified hTg preparations with different iodine and hormone contents were used as reference. Adsorption of purified Tg and serum Tg on immobilized anti-hTg mAb ranged between 85 and 90% over a wide concentration range. Labeled anti-T4 and anti-T3 mAbs bound to adsorbed purified Tg in amounts related to its iodine content. Tg adsorbed from six out of six sera from ST exhibited anti-T4 and anti-T3 mAb binding activities. In contrast, significant mAb binding was only observed in one out of eight sera from untreated GD patients and in 1 out of 13 sera from patients with DTC. The patient with DTC, whose serum Tg contained T4 and T3, represented a case of hyperthyroidism caused by a metastatic follicular carcinoma. In conclusion, we have identified, for the first time, T4 and T3 residues on circulating Tg. The presence of Tg with hormone residues in serum is occasional in GD and DTC but is a common and probably distinctive feature of ST. (+info)