黑斑蛙变态过程中甲状腺发育及甲状腺激素分泌

系统研究了我国本土两栖动物种黑斑蛙（Rana nigromaculata）变态发育过程中甲状腺组织学和甲状腺激素水平的变化,为甲状腺生物学和甲状腺干扰研究提供基础数据。黑斑蛙蝌蚪发育的形态变化: 第26-40阶段,后腿芽生长并逐渐分化出五趾结构;42阶段,开始进入变态高峰期,前肢展开,尾吸收,蝌蚪身体发生巨大形变;46阶段,蝌蚪完全变态成小蛙。随着形态学的变化,甲状腺的组织结构也发生明显的变化: 26-37阶段,甲状腺体积较小,增长缓慢;38阶段甲状腺体积迅速膨大,进入高峰期,甲状腺的发育达到顶峰;随着变态完成,甲状腺又逐渐缩小。甲状腺组织学变化的同时,甲状腺激素水平也相应发生变化: 在变态前期,下颌中3,3',5-三碘代-L-甲腺原氨酸（T3）水平增长缓慢,进入变态期后,T3含量迅速升高,在变态高峰期达到峰值,随后下降。以上结果表明,黑斑蛙发育过程中甲状腺组织学的变化与甲状腺激素水平的波动相吻合。对黑斑蛙甲状腺系统的研究,可为日后使用黑斑蛙开展甲状腺干扰作用的研究提供基础。       

Graves' disease presented as painful goiter

Pain in the thyroid gland is rarely present in Graves' disease. We describe a 32-year-old female hyperthyroid Graves' disease patient with an initial manifestation of painful goiter. On physical examination, the thyroid gland was diffusely enlarged and tender. The laboratory examinations showed high serum thyroid hormone and low thyrotropin values. Serum inflammatory markers, including C-reactive protein and erythrocyte sedimentation rate, were elevated. Thyroid ultrasound revealed multiple focal hypoechoic areas. All these findings gave an initial impression of an acute inflammatory and destructive process in the thyroid gland. However, subsequent thyroid scintigraphy demonstrated a diffuse radioactive iodide uptake pattern with positive serum thyrotropin receptor antibodies. Fine-needle aspiration cytology showed only the presence of lymphocytes. She was diagnosed as having Graves' disease and was treated with propylthiouracil, and prednisolone was given for neck pain. Within a few days, the thyroid tenderness dramatically improved, and the erythrocyte sedimentation rate progressively normalized. However, follow-up thyroid function tests still showed high serum thyroid hormone levels. The possible etiologies of a painful thyroid gland in Graves' disease will be discussed.     

A case study on Hashimoto's thyroiditis induced electrolyte imbalance

Lymphocytic thyroiditis is an autoimmune condition where auto-antibodies are produced against the thyroid gland. Initially, there might be a hyperthyroidism condition where T3 and T4 levels are high and external inflammation of thyroid gland might be seen, but over the course of time the destruction of thyroid gland can result in hypothyroidism where the complete destruction of thyroid gland. Electrolyte imbalances notably hypokalemia and hypomagnesemia with Hashimoto thyroiditis is a rare condition, in this article we will discuss about the course of treatment a 40-year-old female patient who presented with atypical symptoms of Hashimoto thyroiditis during her stay in the hospital.     

Sex dimorphism in the thyroid gland. IV. Cytologic aspects of sex dimorphism in the rat thyroid gland

This study was designed to explain whether the sex-dependent differences in the structure of the thyroid gland of adult male and female rats depend on quantitative or qualitative changes in the thyroid follicular cells. Absolute thyroid gland weight was similar in male and female rats, but its relative weight was markedly higher in females however. Volume fractions of epithelium and stroma were higher and that of colloid lower in male than in female rats and the epithelium/colloid ratio was higher in the males. Also absolute the volumes (in mm3) of epithelium and stroma were higher in the males; the thyroid gland of females contained more colloid. The average volume of a thyroid follicular cell, estimated by stereology, was higher in males than in females, although the thyroid gland contained similar numbers of follicular cells in both sexes. Also, thyroid glands from both male and female rats contained a similar DNA quantity. Results of the present study show that the sex dimorphism in the rat thyroid depends upon a difference in the mean volume of thyroid follicular cells, with males having larger cells than females. However, in both sexes the thyroid gland contains a similar quantity of these cells.     

The interaction of the thyroid gland, pineal gland and immune system in chicken

The interaction of immunological system, thyroid and pineal gland was studied in 5-week old males of Gallus domesticus. Several morphometrical parameters in pineal and thyroid glands were measured after bird immunization with human red blood cells and/or treatment with melatonin or seduxen, melatonin receptor blocker. The peak of the thyroid activity was found on Day 7 after immunization. The immune system appears to directly activate the thyroid gland only in the presence of certain level of melatonin. We suggest that the melatonin mechanism of action includes the enhancement of thyroid gland sensitivity to immune factors. Seduxen prevented the stimulatory influence of the immune system on the thyroid gland.     

METASTATIC CARCINOMA OF THE THYROID GLAND AS THE INITIAL MANIFESTATION OF THE DISEASE

During the past 38 years, 260 patients with thyroid carcinoma have been operated upon at the University of California Hospital. In 26 of these patients the first symptom was a mass distant from the thyroid gland, and the gland was considered normal on clinical examination.In all but three of the 26 cases a small carcinoma of the thyroid gland was observed at operation or in pathological examination.Radical neck dissection with either total lobectomy or total thyroidectomy would seem to be the operation of choice in the treatment of these patients.The ultimate prognosis, even in the presence of metastases, is relatively good.Primary carcinoma of the thyroid gland should be considered in the presence of tumors of the side of the neck even in the absence of palpable nodules in the gland itself.     

Daily variation in antioxidant enzymes lipid peroxidation in thyroid and plasma level thyroxine and triiodothyronine levels of a tropical bird Perdicula asiatica during reproductively active and inactive phases

The aim of this work was to study the variations in the interference of neuroendocrine pineal gland and metabolically active thyroid gland in a tropical bird, Perdicula asiatica. Maximum pineal gland activity (pineal weight and melatonin level), minimum thyroid gland activity (weight, T3/T4 and thymidine kinase activity) along with less oxidative load (MDA level, SOD, CAT and ABTS activity) were observed during reproductively inactive phase (RIP) was observed. Further, a robust and significant rhythmicity was noted in melatonin levels during RIP and RAP, but no significant rhythmicity was noted in T4/T3 level by cosinor analysis. Overall, melatonin and thyroid circadian profile suggested that melatonin might be acting as an antioxidant molecule with time of the day effect in rescuing thyroid gland from free radical load in birds.     

Microbial adjuvant and autoimmunity. II. Production of lesions in mice immunized with syngeneic tissue extracts together with the capsular polysaccharide of Klebsiella pneumoniae.

The target organs of mice immunized with the respective syngeneic tissue extracts together with the capsular polysaccharide of Klebsiella pneumoniae (CPS-K) as a powerful adjuvant were examined for production of lesions. In 15 out of 24 mice injected three times or more with syngeneic eyeball extracts and CPS-K adjuvant at intervals approximately 30 days, severe eyeball lesions developed in which the normal structure was almost completely lost. A large part of the eyeball tissue of these mice was replaced by infiltration with cells such as lymphocytes, plasma cells and other mononuclear cells and by connective tissue. No definite eye lesions developed in mice injected with CPS-K alone, eyeball extracts alone or eyeball extracts emulsified in complete Freund's adjuvant (CFA). In all of mice injected four times with thyroid gland extracts and CPS-K at intervals of approximately 30 days, definite thyroid gland lesions were produced. In three out of five mice of this group, the thyroid lesions were so severe that the normal thyroid follicular structure was almost completely lost, and a large part of the thyroid gland was replaced by infiltration with lymphocytes, plasma cells and other mononuclear cells and in part by connective tissue. In only one out of five mice injected with thyroid gland extracts emulsified in CFA, definite but milder thyroid gland lesions developed. No definite thyroid lesions developed in the remaining four mice of this group and also in any of the mice injected with thyroid gland extracts alone or CPS-K alone. Repeated injections of lymphoid tissue extracts and CPS-K also induced pathological changes in the spleen and lymph nodes, although less marked than those in the cases of the eyes and thyroid gland. The most remarkable change was a decrease in numbers of small lymphocytes at the areas surrounding the central arterioles in the white pulp of the spleen and the post-capillary venules in the cortex of the lymph nodes. From these results it has been concluded that our system can provide new and useful models for autoimmune diseases in man.     

Ultrasonic scan of the thyroid gland during the treatment of endemic goiter with L-thyroxine

Forty three adolescents of both sexes (26 female, 17 male) aged between 16 and 19 years with struma diffusa juvenilis were treated with L-thyroxine for 16 months. Size of the thyroid gland was classified according to WHO. The percentage of stages was the following; Ia-12%, Ib-69%, and II-19%. The patients were given L-thyroxine in a daily dose of 100 micrograms. Patients' compliance and the results of therapy were controlled every 4 months, measuring thyroid gland size with ultrasound scan and determining T3, T4 and TSH in serum. It was found that: 1. L-Thyroxine significantly reduces the volume of thyroid gland with insignificant changes in serum T3, T4, and TSH levels. 2. Ultrasound volumetry of the thyroid gland is a precise morphometric technique, reproducible with high degree of specificity. 3. Monotherapy with L-thyroxine given for at least one year is effective in endemic goitre. The authors discuss also literature on ultrasound volumetry of the thyroid gland and therapies in comparison with own results.     

Morphological study of the neurosecretory hypothalamo-hypophyseal system and thyroid gland in intestinal carcinogenesis]

Pathomorphology of the neurosecretory hypothalamo-hypophyseal system and the thyroid gland of 150 rats of both sexes was investigated in intestinal carcinogenesis induced by 1.2-dimethyl hydrazine. Inhibition of the neurosecretory activity of paraventricular and supraoptical nuclei as well as atrophic changes in th: thyroid gland were found to be associated with the latent period of carcinogenesis. The arising of the intestinal tumor is accompanied by hypertrophy of neurons and their nuclei, by a decrease in the neurosecretory substance content and the thyroid gland tendency to return to normal. The tumor spreading provoked neuron hypertrophy and the reduction of the neurosecretory substance as well and pronounced atrophic changes in the thyroid gland.     

Oncogene expression in a medullary thyroid carcinoma

We report the expression of Ha-ras, fos, c-myc and N-myc mRNA in a human medullary carcinoma of the thyroid gland, both in primary tumor and lymph node metastasis, as demonstrated by in situ hybridization and Northern blot analysis. A significant difference in the oncogene expression in the primary tumor and the metastasis was not observed. Tumor tissue revealed a significant overexpression of Ha-ras, c-myc and N-myc mRNA as compared to the normal thyroid gland. The amount of fos mRNA expression in non tumorous thyroid gland did not significantly differ from tumor tissue, sis, fms and abl mRNA expression was not detectable in tumor tissue and non tumorous thyroid gland. We conclude, that the (over)expression of the oncogenes Ha-ras, c-myc and N-myc may be associated with initiation and progression of medullary thyroid carcinoma. Similar studies on additional cases of human medullary thyroid carcinoma will be necessary to reveal further information.     

Histo-morphology of the thyroid gland during the larval development of Pleurodema borellii (Anura,Leptodactylidae)

The thyroid gland is essential in anurans, since thyroid hormones (TH) are the main regulators of larval development. Its absence or inactivity interrupts development and precludes metamorphosis. Histological changes are important diagnostic criteria for evaluating thyroid gland activity. However, there is a large larval diversity where the development of the thyroid gland development has not been studied. Pleurodema borellii is an anuran from northwest of Argentina with typical omnivorous pond tadpoles that can be easily raised in captivity. This study explores the histo-morphological changes of the thyroid gland architecture during larval development. Histological parameters indicate peak glandular activity in parallel with the intensity of the metamorphic transformations. These parameters regress towards the end of metamorphosis, indicating low TH release. P. borellii's thyroid gland does not appear to have relevant activity in post-metamorphic juvenile stages. This study is a first step towards understanding endocrine regulation during the development of Pleurodema borellii, and a reference to future studies in this species involving thyroid-dependent processes.     

Mechanistic considerations for the relevance of animal data on thyroid neoplasia to human risk assessment

There are two basic mechanisms whereby chemicals produce thyroid gland neoplasia in rodents. The first involves chemicals that exert a direct carcinogenic effect in the thyroid gland and the other involves chemicals which, through a variety of mechanisms, disrupt thyroid function and produce thyroid gland neoplasia secondary to hormone imbalance. These secondary mechanisms predominantly involve effects on thyroid hormone synthesis or peripheral hormone disposition. There are important species differences in thyroid gland physiology between rodents and humans that may account for a marked species difference in the inherent susceptibility for neoplasia to hormone imbalance. Thyroid gland neoplasia, secondary to chemically induced hormone imbalance, is mediated by thyroid-stimulating hormone (TSH) in response to altered thyroid gland function. The effect of TSH on cell proliferation and other aspects of thyroid gland function is a receptor mediated process and the plasma membrane surface of the follicular cell has receptors for TSH and other growth factors. Small organic molecules are not known to be direct TSH receptor agonists or antagonists; however, various antibodies found in autoimmune disease such as Graves' disease can directly stimulate or inhibit the TSH receptor. Certain chemicals can modulate the TSH response for autoregulation of follicular cell function and thereby increase or decrease the response of the follicular cell to TSH. It is thus important to consider mechanisms for the evaluation of potential cancer risks. There would be little if any risk for non-genotoxic chemicals that act secondary to hormone imbalance at exposure levels that do not disrupt thyroid function. Furthermore, the degree of thyroid dysfunction produced by a chemical would present a significant toxicological problem before such exposure would increase the risk for neoplasia in humans.     

Measurement of thyroid hormone in the rat thyroid gland by radioimmunoassay

The present paper describes (i) a hydrolysis technique with Pronase and leucine aminopeptidase using one rat thyroid gland, resulting in maximum release of thyroid hormones and minimum deiodination, and (ii) a simple and rapid procedure for thyroid hormone radioimmunoassays in thyroid hydrolysates using commercial kits intended for serum thyroid hormone determinations. The procedure is used to determine T4, T3, and rT3 concentrations and hormonal molar ratios in a thyroid gland from a male Wistar rat. The reliability of the method is also studied.     

Relationship of biochemical and morphological changes in rat thyroid and proton spin-relaxation of the tissue water.

The effect was studied of biochemical and morphological changes induced by antithyroid substances (PTU, C10(-4)) on proton spin-relaxation properties of rat thyroid gland. It was found that thyroid stimulated by PTU (0.05%) or C10(-4) (1.0%) exhibit marked morphological changes (hyperplasia and epithelial hypertrophy) with alteration of the soluble iodoprotein pattern (content and composition.). Both relaxation times spin-lattice (T1) and spin-spin (T2) were increasing with the lenght of treatment with antithyroid drugs. Reversibility of the process was noted in accordance with biochemical and morphological data. The relaxation rate (formula: see text) for thyroid tissue water was in positive correlation with the suluble protein concentration and particularly with the TG content in the gland. There was no difference in relaxation times between normal thyroid and gland of rats treated chronically with excess iodide. The observed difference in T1 between normal glands and glands of PTU,-C10(-4)--treated rats was comparable with that found in cases of human thyroid cancer. This finding is of importance when the diagnostic potential of NMR in the detection of malignancy is considered. In conclusion, a strong correlation was found between microstructural and biochemical changes of the thyroid gland and proton magnetic relaxation of tissue water. The striking difference between the proton spin-relaxation times in normal and in goiter thyroid glands of rats suggests that pulsed NMR spectroscopy could be a method for evaluation of some disturbances in thyroid gland.     

Localization and role of leptin in the thyroid gland of the lizard Podarcis sicula (Reptilia, Lacertidae)

Leptin, the product of the ob gene, is a hormone secreted by adipocytes that regulates food intake and energy expenditure. The hypothalamus-pituitary-thyroid axis is markedly influenced by the metabolism status, being suppressed during food deprivation. The present study was designed to ascertain whether (1) lizard thyroid gland expresses the long form of leptin receptor (Ob-Rb) and (2) the leptin administration affects the thyroid gland activity in this species (and to verify whether leptin plays a similar role in reptiles as observed in the other vertebrates). The presence of leptin receptor in the thyroid gland of Podarcis sicula was demonstrated by immunohistochemical technique (avidin-biotin-peroxidase complex--ABC method). The role of leptin in the control of thyroid gland activity was studied in vivo using light microscopy (LM) technique coupled to a specific radioimmunoassay for thyroid-stimulating hormone (TSH) and thyroid hormones (T4 and T3). Leptin (0.1 mg/100 g body wt)/day increased T4 and T3 release for 3 days but decreased the plasma concentration of TSH; using LM clear signs of stimulation in the thyroid gland were observed. These findings suggest that systemic administration of leptin stimulates the morphophysiology of the thyroid gland in the lizard through a direct mechanism involving Ob-Rb.     

Complex estimation of thyroid gland state in tundra voles, inhabiting the natural radioactive polluted sites

Behow is presented the complex state of thyroid gland of tundra voles living in high level natural radioactivity conditions (Ukhta region of Komi Republic) by morphological and functional criteria. High sensitivity of thyroid gland under natural chronic irradiation of whole organism is noticed. The essential changes in the morphological structure and in the hormone level of the thyroid gland are found in animals, which live for a long time in the conditions of the radioactive pollution. It is determined, that the inside population processes influence on the structure and on the funcition of the thyroid gland.     

Metastatic Renal Cell Carcinoma to the Thyroid Gland

ObjectiveTo examine the presentation, diagnosis, and appropriate management of renal clear cell carcinoma metastasis to the thyroid gland.MethodsWe describe a clinical case of solitary thyroid metastasis from renal clear cell carcinoma and present a comprehensive review of the related English-language literature. Common patterns of presentation and generalized overall management recommendations are evaluated and summarized.ResultsEight years after nephrectomy for renal carcinoma at age 61 years, a man presented with a thyroid mass. Cytology and histopathologic surgical findings were consistent with a solitary metastasis most compatible with metastatic clear cell carcinoma from his previous renal carcinoma. After left thyroid lobectomy and isthmusectomy, the patient remains disease-free 5 years later. Although uncommon, nearly 150 cases of clinically recognized metastatic renal cell carcinoma to the thyroid have been reported in the English-language literature. Metastatic disease from the kidney to the thyroid gland can occur more than 20 years after nephrectomy with the average time interval being 7.5 years. Obtaining a full clinical history in any patient who presents with a thyroid nodule is essential to allow consideration of possible metastatic disease from previous primary tumor. Metastatic disease to the thyroid gland can be correctly diagnosed preoperatively. If metastatic renal cancer is limited to the thyroid gland only, prompt, appropriate surgical intervention can be curative.ConclusionMetastatic renal carcinoma to the thyroid should be considered in any patient presenting with a thyroid mass and a medical history of renal cell carcinoma. (Endocr Pract. 2008;14:1040-1046)     

Response of the thyroid gland of the lizard Podarcis sicula to endothelin-1

Although endothelins were originally discovered as peptides with vasoconstrictor activity, recent studies have indicated a number of endothelin (ET) induced hormonal functions in various tissues. We have studied the interaction of ET-1 with thyroid gland of the lizard Podarcis sicula. The effects of ET-1 administration on the plasma levels of the thyroid hormones (T3 and T4) and TSH were stimulatory. Morphological changes in the thyroid after treatment with ET-1 were also detected: the height of the epithelial cells slightly increased and the apical surface acquired microvilli protruding into the follicular lumen. The colloid filled up the lumen and showed a rich peripheral vacuolation. In conclusion, a modulatory role in the control of the reptilian thyroid gland is suggested for ET-1. This is the first report on the interaction of ET-1 with the thyroid gland of reptilian.