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Adenomatous hyperplasia of the thyroid gland in beluga whales (Delphinapterus leucas) from the St. Lawrence Estuary and Hudson Bay, Quebec, Canada.

We evaluated thyroid gland lesions in beluga whales (Delphinapterus leucas) from the St. Lawrence Estuary (n = 16) and Hudson Bay (n = 14). Follicular cysts and nodules of adenomatous hyperplasia of the thyroid gland were found in eight and nine adults from the St. Lawrence Estuary (n = 10), respectively, and in four and six adults from Hudson Bay (n = 14), respectively. The total volume of the lesions of thyroid adenomatous hyperplasia was positively correlated with age in both populations. Comparison between populations could not be performed because of differences in age structures of sample groups. Beluga whales from both populations have unique thyroid lesions among marine mammals.

Age Factors↗

[Selenium concentration in serum of women with thyroid gland disease].

The aim of this study was to estimate the concentration of total selenium in serum women with thyroid gland disease. Selenium was determined by atomic absorption spectrometry using the hydride generation technique (HG-AAS). Selenium was determined in 30 patients with thyroid gland disease and in 12 healthy controls. Selenium concentration of serum was variously in patients than in control group and patients with different thyroid gland disease. The average concentration of selenium in control group was 0.0694 microg/ml, in goiter group 0.0529 microg/ml, in hyperactivity group 0.0441 microg/ml, in hypofunction group 0.0520 microg/ml.g/ml.

Adult↗

Adenolipoma of the thyroid gland: report of a case.

We report a case of adenolipoma of the thyroid gland, which is very unusual because thyroid adenoma rarely contains mature adipose tissue. A 55-year-old Japanese woman presented with a 1-month history of a neck mass. A blinded fine-needle aspiration biopsy showed benign follicular cells with no adipose cells, and we performed a left hemithyroidectomy. The specimen measured 7.0 x 4.4 cm and weighed 59.9 g. The cut surface of the tumor revealed a solid yellowish mass, and hematoxylin-eosin staining showed that the solid tumor was well separated from the adjacent thyroid tissue by a thin fibrous capsule. The tumor was found to be follicular adenoma composed of epithelial cells arranged in monotonous microfollicular patterns, intermingled with mature adipose tissue. No adipose tissue was found outside the tumor, and there were no signs of amyloid deposits in the tumor or adjacent thyroid tissue. The pathological diagnosis was adenolipoma of the thyroid gland. We discuss the pathogenesis of this entity and review the previously documented cases.

Adipose Tissue↗

Partial purification and characterization of myosin light chain kinase from bovine thyroid gland.

Myosin light chain kinase has been purified approximately 1700-fold from bovine thyroid gland, using Affigel blue column chromatography, ammonium sulfate fractionation (0-60% saturation), Sepharose 6B gel filtration, and calmodulin-Sepharose affinity column chromatography. This partially purified kinase was Ca2+ and calmodulin dependent for its activity and specifically phosphorylated the 20,000-dalton light chain of chicken gizzard myosin. At higher CaCl2 concentration, thyroid myosin light chain kinase demonstrated a novel inhibition in the presence of calmodulin. The mechanism of this Ca2+-dependent inhibition is not clear at present. The existence of myosin light chain kinase in thyroid gland provides additional support for the role of the contractile system in the secretion of thyroid hormones.

Animals↗

[Morphological characteristics of the thyroid glands of Macaca rhesus monkeys normally and in different types of hypokinesia].

Thyroid glands and C-cells of Macaca rhesus were examined histologically, electron microscopically and morphometrically. The examinations were performed on 6 intact and 7 hypokinetic rhesus monkeys which were kept in a suspension device for 2 months, small cages for 2 months or in a head-down position (7 days in a horizontal position and then 11 days in a head-down position at -6 degrees). The experiment with a diminished motor activity and a normal support function of the lower limbs (maintenance in small cages), in spite of its long duration, produced no structural changes in the parenchyma or C-cells. The 18-day bed rest test was followed by a hypofunction of the thyroid gland, inhibition of hormonal synthesis and secretion without distinct changes in C-cells. Unlike previous experiments, the suspension study led to hyperplasia and hypertrophy of C-cells and increase of their nuclear volume. Activation of C-cells can be regarded as an adaptive reaction aimed at stabilizing bone calcium.

Adaptation, Physiological↗

Nondiagnostic fine needle aspiration biopsy of the thyroid gland: a diagnostic dilemma.

OBJECTIVE: To evaluate all nondiagnostic fine needle aspiration biopsy (FNAB) specimens from the thyroid gland with subsequent histopathologic diagnoses at Ottawa Civic Hospital. The criterion for specimen adequacy used in our institution was also reexamined to determine if it was too stringent. STUDY DESIGN: Review of 114 nondiagnostic FNAB samples from 91 patients with subsequent histopathologic diagnoses formed the basis of this study. Specimen adequacy was determined by the presence of 8-10 fragments of well-preserved follicular cells on at least two smears. RESULTS: Review of the 91 surgical specimens found 50 nodular goiters, 23 follicular adenomas, 6 macrofollicular adenomas, 5 cases of thyroiditis, 5 true cysts, 1 papillary carcinoma and 1 minimally invasive follicular carcinoma. Forty-two percent of lesions showed cystic change. In addition, nine cases of papillary microcarcinoma were diagnosed. A considerable difference in the rate (22% vs. 45%) of inadequate thyroid FNAB samples was identified among different groups of physicians at our institution. CONCLUSION: Ninety-eight percent of the patients with nondiagnostic FNAB of the thyroid gland had benign lesions. This finding encouraged us to continue using our criteria for adequacy because of the importance of a negative report. The higher rate of nondiagnostic thyroid aspiration in our series may reflect the varied experience of the different aspirators at our institution and/or the cystic nature of many of the lesions.

Adenoma↗

Ectopic thyroid gland in the porta hepatis and lingua.

A rare case of an ectopic thyroid gland in the porta hepatis and in the tongue in an asymptomatic euthyroid 24-year-old woman is reported. A solitary inhomogeneous, hypoechogenic and hyperechogenic mass in the porta hepatis was accidentally discovered by ultrasonography. Subsequent computed tomography demonstrated a heterogeneous, well-defined tumor with small calcifications without signs of environmental invasion. A hemangioma and focal nodular hyperplasia were excluded by blood pool and hepatobiliary scintigraphy. Surprisingly, fine-needle aspiration cytology revealed normal thyroid tissue. (123)I-scintigraphy confirmed the presence of ectopic dual thyroid tissue in the hepatic porta and lingua. At clinical inspection the lingual thyroid gland was palpable and visible, and appeared solid and spheroidal. The subhepatic, ectopic thyroid mass was resected. Postoperatively, thyroid hormone replacement was started to prevent an enlargement of the lingual thyroid. Today, 4 years after surgery, the patient remains euthyroid.

Adult↗

[The so-called goiter of the accessory thyroid glands].

In the period of 1954-1966, 74 patients were operated on for goiter of the accessory thyroid glands (GATG). Of them, in 45 in histologic investigation, papillary adenoma or microfollicular, less often parenchymatous, goiter were revealed, in 29--papillary cancer or papillary adenoma at the state of malignization. The long-term follow-up (up to 30 years) of the patients with reoperations for GATG recurrences, or subsequent development of a "goiter" has shown that GATG presented a metastasis of papillary thyroid cancer into the lateral lymph nodes of a neck. At operation, the revision of a thyroid gland with intervention on it is mandatory. The term GATG we haven't used from 1966.

Adolescent↗

[Technique and use of fine needle puncture for thyroid gland (author's transl)].

Fine needle puncture of cold and warm thyroid gland nodes has its definite place in the diagnostic repertory of thyroid diseases. This method can be performed rapidly and easily. It has a low complication rate and imparts to the physician a maximum of information in association with in-vitro tests and scintigram. Indication and technique of fine needle puncture are described and discussed.

Adult↗

Discovery of a novel and alternate hydrogen peroxide generation machinery in the mammalian thyroid gland that modulates iodination of tyrosine.

The hydrogen peroxide-dependent and peroxidase-mediated iodination of tyrosine, a pivotal step in the thyroxine biosynthesis in thyroid glands of mammals, has always been thought to be dependent on a glucose-glucose oxidase system to meet its demand for hydrogen peroxide. This report documents a novel and probably kinetically faster hydrogen peroxide-generating system operating in the thyroid gland cells involving the superoxide dismutase and superoxide anion radical. In the female cycling mice, the superoxide radical and superoxide dismutase activity are shown to be at persistently high levels, quite likely acting as a potent hydrogen peroxide synthesizer in the mammalian thyroid gland. The significance of this discovery in relation to the thyroid physiology is discussed.

Animals↗

[Effects of chronic administration of high doses of potassium iodide on iodine metabolism in the rat thyroid gland].

The effect of various doses of KI on iodine methabolism in rat thyroid gland was investigated. Treatment with 1, 3, 10, 100 and 500 physiological daily doses of KI for 14 days had no influence on blood level of thyroid hormones. However, increased administration of KI was accompanied by the increase of iodine in the thyroid gland tissue by 60-121% due to 35-108% and 94-128% increases of protein-bound and free fractions respectively. Chronic treatment with both low and high doses of KI was accompanied by oxidative stress. It is suggested that reactive oxygen species and highly iodinated proteins (particularly thyroglobulin) induced by chronic ingestion of high doses of KI can play the important role in the development of thyroid dysfunctions and autoimmune diseases.

Animals↗

Pathomorphology of thyroid gland lesions associated with radiation exposure: the Chernobyl experience and review of the literature.

The common sources of ionizing radiation exposure to the thyroid gland in humans are accidental environmental exposure and medical, therapeutic, or diagnostic irradiation. Radiation often induces notable histologic changes in the thyroid tissue and is a well-established risk factor for benign and malignant thyroid tumors. In this paper, we review the acute and chronic histologic changes in the thyroid gland subjected to irradiation, and characterize benign thyroid nodules and malignant tumors arising after exposure, with particular emphasis on thyroid lesions in the population exposed to ionizing radiation as a result of the Chernobyl nuclear accident.

Acute Disease↗

Immunoelectron microscopic localization of thyroglobulin in the human thyroid gland.

The microidentification of the organelles containing thyroglobulin (TG) in the follicular cells of human thyroid glands were studied by the immunoelectron microscopic method. Fresh human thyroid glands were used for the purification of TG. TG was purified by differential salt fractionation and DEAE-cellulose chromatography. Anti-human TG rabbit IgG antibody was obtained by immunization of this purified TG. F(ab')2 fragments of anti-TG rabbit IgG antibody were prepared by pepsin digestion. The specificity of the antibody was tested on an Ouchterlony immunodiffusion plate. Conjugation of the purified F(ab')2 fragments of anti-TG rabbit IgG antibody to horse radish peroxidase was performed in order to use the direct peroxidase labelled antibody method. Under immunohistochemical light microscopy, the luminal colloid and the follicular cells appeared heavily stained. Under immunoelectron microscopy, positive reactions were observed in the rough endoplasmic reticulum, the Golgi apparatus, and the apical cell border. To date, no clear direct evidence of the presence of TG in the rough endoplasmic reticulum and the Golgi apparatus of human thyroid cells has ever been reported in immunoelectron microscopic studies. This study indicates that the use of F(ab')2 fragments of anti-TG rabbit IgG antibody in immunoelectron microscopic study is useful for the identification of TG in organelles of human thyroid follicular cells.

Chromatography, DEAE-Cellulose↗

Metastases to the thyroid gland: diagnosis by aspiration cytology.

The purpose of this study was to document the incidence, nature and source of neoplasms metastatic to the thyroid gland, which were diagnosed by fine needle aspiration (FNA) cytology. In the seven year period from 1986 to 1992, 21 cases were identified with metastatic malignancies in FNA specimens from the thyroid. This represented 7.5% of neoplastic thyroid lesions aspirated in this unit. All patients presented clinically with thyromegaly or discrete nodules. Only five patients were known to have malignancies of other sites prior to FNA. The majority of metastatic nodules were bronchogenic in origin (nine). The gastrointestinal tract (five) and melanomas (two) were the next most frequent sources in the series. Single cases arose in the prostate, larynx, kidney (all carcinomas), and uterus (a leiomyosarcoma). One patient had a thyroid deposit of acute myeloblastic leukemia. This large study demonstrated that tumors of many histological types may involve the thyroid gland, and furthermore, may masquerade as primary thyroid malignancies. Recognition of an alien cell type not only prevents inappropriate thyroid surgery, but may also direct the search for the unsuspected or unknown primary. Metastases to the thyroid gland occur more frequently than is generally appreciated. FNA is the procedure of choice for evaluation of thyroid nodules in general, and thyroid metastases in particular.

Adenocarcinoma↗

Comparison of potential protective effects of melatonin, indole-3-propionic acid, and propylthiouracil against lipid peroxidation caused by potassium bromate in the thyroid gland.

Potassium bromate (KBrO3) is a prooxidant and carcinogen, inducing thyroid tumors. Melatonin and indole-3-propionic acid (IPA) are effective antioxidants. Some antioxidative effects of propylthiouracil (PTU)--a thyrostatic drug--have been found. The aim of the study was to compare protective effects of melatonin, IPA, and PTU against lipid peroxidation in the thyroids, collected from rats treated with KBrO3, and in homogenates of porcine thyroids, incubated in the presence of KBrO3. Wistar rats were administered KBrO3 (110 mg/kg b.w., i.p., on the 10th day of the experiment) and/or melatonin, or IPA (0.0645 mmol/kg b.w., i.p., twice daily, for 10 days), or PTU (0.025% solution in drinking water, for 10 days). Homogenates of porcine thyroids were incubated for 30 min in the presence of KBrO3 (5 mM) plus one of the antioxidants: melatonin (0.01, 0.1, 0.5, 1.0, 5.0, 7.5 mM), or IPA (0.01, 0.1, 0.5, 1.0, 5.0, 7.5, 10.0 mM), or PTU (0.01, 0.1, 0.5, 1.0, 5.0, 7.5, 10.0 mM). The level of lipid peroxidation products (MDA + 4-HDA) was measured spectrophotometrically in thyroid homogenates. In vivo pretreatment with either melatonin or with IPA or with PTU decreased lipid peroxidation caused by KBrO3--injections in rat thyroid gland. Under in vitro conditions, PTU (5.0, 7.5, and 10.0 mM), but neither melatonin nor IPA, reduced KBrO3-related lipid peroxidation in the homogenates of porcine thyroids. In conclusion, melatonin and IPA may be of great value as protective agents under conditions of exposure to KBrO3.

Animals↗

The oxyphil and C cells of the human thyroid gland. A cytochemical and histopathologic review.

The C and oxyphil cells of the human thyroid are analyzed in the light of recent advances in cellular biology, cytochemistry, and histopathology. The C cell is present in the normal human thyroid, where its identification is cardinally by means of argyrophilic cytoplasmic granules. The morphology, topography and argyrophilia of C cells are discussed with reference to tumor, cyst, and teratoma formation in the thyroid gland. Oxyphil cells of the thyroid are cytochemically akin to C cells but arise from follicular cells. They occur in the thyroid and other protein-producing organs, but are themselves inefficient producers of proteins and glycoproteins. Speculation is made on their morphological characteristics, and consideration is given to DNA-RNA involvement in the functional and morphological alterations of this follicular cell type.

Adenoma↗

Thyroid Peroxidase Expression in Diseased Human Thyroid Glands.

Histoenzymologic studies of the human thyroid have been restricted to attempts to differentiate benign from malignant tumors and, to our knowledge, there is no systematic study on the distribution and behavior of enzymes for several types of lesions of the thyroid gland. The aim of the present study was to investigate thyroid peroxidase (IPO) expression in diseased thyroids, as well as to study the role of this enzyme as a parameter to define the biological behavior of thyroid lesions. A total of 1 17 neoplastic and nonneoplastic lesions of the thyroid were evaluated. The expression of TPO was determined by the analysis of at least 200 cells/specimen. A rate of 80% of positive cells was considered a threshold for TPO positivity. TPO expression was detected in all nonneoplastic lesions of thyroid as well as in 78.8% of the adenomas. We also observed positivity for TPO in 20% of malignant lesions. Therefore, these findings do not allow separation of benign and malignant lesions of the thyroid based in the expression of TPO.

Journal Article↗