994 resultados para Thyroid Gland -- metabolism


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To investigate whether there is an increased incidence of chronic autoimmune thyroiditis (CAT) in individuals living in the vicinity of industrial plants that manufacture petroleum byproducts in the state of So Paulo, Brazil. Between 1989 and 2004, 6,306 patients of both sexes, from 5 to 78 years old were divided in two groups according to their home location: Group 1: 3,356 residents living near industrial plants that manufacture petroleum byproducts (Region A), and Group 2: 2,950 residents living far from Region A in an area with predominantly steel industries (Region B). For all patients, we measured the serum levels of antithyroglobulin antibody, antithyroperoxidase antibody, triiodothyronine, thyroxine, free thyroxine and thyrostimulating hormone. Sonographic scans of the thyroid gland were also conducted. The proportion of patients with CAT coming from Region A increased from 2.5 % (5 patients with CAT/200 total patients) in 1992 to 57.6 % (106 patients with CAT/184 total patients) in 2001. This striking increase was highly significant (p < 0.001). Similar findings were not observed in Region B. The difference in the number of patients with CAT between 1989 and 2004 coming from Region A and Region B was highly significant (p < 0.001), with 905 CAT patients (83.95 %) in Region A and 173 CAT patients (16.05 %) in Region B. Our results showed a striking increase in the incidence of CAT in residents in the vicinity of large industrial plants that manufacture petroleum byproducts compared with residents living near steel industries, which opens the field to new areas of research.

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Objective: To evaluate frequency, anatomic presentation, and quantities of supernumerary parathyroids glands in patients with primary hyperparathyroidism (HPT1) associated with multiple endocrine neoplasia type 1 (MEN1), as well as the importance of thymectomy, and the benefits of localizing examinations for those glands. Methods: Forty-one patients with hyperparathyroidism associated with MEN1 who underwent parathyroidectomy between 1997 and 2007 were retrospectively studied. The location and number of supernumerary parathyroids were reviewed, as well as whether cervical ultrasound and parathyroid SESTAMIBI scan (MIBI) were useful diagnostic tools. Results: In five patients (12.2%) a supernumerary gland was identified. In three of these cases (40%), the glands were near the thyroid gland and were found during the procedure. None of the imaging examinations were able to detect supernumerary parathyroids. In one case, only the pathologic examination could find a microscopic fifth gland in the thymus. In the last case, the supernumerary gland was resected through a sternotomy after a recurrence of hyperparathyroidism, ten years after the initial four-gland parathyroidectomy without thymectomy. MIBI was capable of detecting this gland, but only in the recurrent setting. Cervical ultrasound did not detect any supernumerary glands. Conclusion: The frequency of supernumerary parathyroid gland in the HPT1/MEN1 patients studied (12.2%) was significant. Surgeons should be aware of the need to search for supernumerary glands during neck exploration, besides the thymus. Imaging examinations were not useful in the pre-surgical location of these glands, and one case presented a recurrence of hyperparathyroidism.

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An 11-year-old girl presented with sudden sensory disturbance and left-sided muscle weakness. MRI revealed ischaemic change in the right lateral thalamus and the right internal capsule. During sonographic work-up of the cervical arteries, inflammation of the thyroid gland was noted. The results of the thyroid function tests and antibody titers confirmed Hashimoto thyroidits. Under high-dose corticosteroids, the girl had a full neurological recovery.

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In clinical diagnostics, it is of outmost importance to correctly identify the source of a metastatic tumor, especially if no apparent primary tumor is present. Tissue-based proteomics might allow correct tumor classification. As a result, we performed MALDI imaging to generate proteomic signatures for different tumors. These signatures were used to classify common cancer types. At first, a cohort comprised of tissue samples from six adenocarcinoma entities located at different organ sites (esophagus, breast, colon, liver, stomach, thyroid gland, n = 171) was classified using two algorithms for a training and test set. For the test set, Support Vector Machine and Random Forest yielded overall accuracies of 82.74 and 81.18%, respectively. Then, colon cancer liver metastasis samples (n = 19) were introduced into the classification. The liver metastasis samples could be discriminated with high accuracy from primary tumors of colon cancer and hepatocellular carcinoma. Additionally, colon cancer liver metastasis samples could be successfully classified by using colon cancer primary tumor samples for the training of the classifier. These findings demonstrate that MALDI imaging-derived proteomic classifiers can discriminate between different tumor types at different organ sites and in the same site.

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A 7-month-old male kitten was presented with chronic constipation and retarded growth. Clinical examination revealed disproportional dwarfism with mild skeletal abnormalities and a palpable thyroid gland. The presumptive diagnosis of congenital hypothyroidism was confirmed by low serum total thyroxine (tT(4)) concentration prior to and after the administration of thyroid stimulation hormone (TSH), increased endogenous TSH concentration and abnormal thyroid scintigraphic scan. The kitten had abnormal liver function tests and decreased insulin-like growth factor 1 (IGF-1) concentration, both of which returned to normal in correspondence with an improvement of the clinical signs after 6 weeks of thyroxine therapy. Congenital hypothyroidism is a rare disease that may present with considerable variation in clinical manifestation. In cases in which clinical signs are ambiguous, disorders such as portosystemic shunt and hyposomatotropism have to be taken into account as differential diagnosis. As hypothyroidism may be associated with abnormal liver function tests and low IGF-1 concentrations, test results have to be interpreted carefully.

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The Chernobyl tragedy was the biggest accident since the beginning of the nuclear power industry. The aim of this study was to determine the role of immunological mechanisms in the development of autoimmune disorders (thyroiditis and cataract) and cancers among those workers who participated in clean-up operations in 1986. Blood samples from 165 clean-up workers aged 30-65 from Minsk and Kiev who underwent prophylactic medical examinations and from 80 healthy donors were investigated for the presence of autoimmune reactions and the appearance of onco-foetal antigens. The sera of clean-up workers were found to include the thyroid gland antigen, auto-antibodies to thyroid gland and eye antigens, and immune complexes which are normally absent or found in much lower quantities. The appearance of the clinically unmanifested thyroid gland antigen made it possible to generate a concept describing the mechanism for induction and long-term maintenance of auto-antibody production in an organism after irradiation. Lymphocytes from clean-up workers showed normally absent onco-foetal antigens (PSG and CEA). The data obtained indicate that clean-up workers represent a high risk group for autoimmune and cancer diseases. Immunological findings reveal the long-lasting effects of low doses of irradiation and may be used in prognosis and monitoring of human health.

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STUDY DESIGN: A prospective case control study design was conducted. OBJECTIVES: The purpose of the current study was to determine the intraoperative radiation hazard to spine surgeons by occupational radiation exposure during percutaneous vertebroplasty and possible consequences with respect to radiation protection. SUMMARY OF BACKGROUND DATA: The development of minimally invasive surgery techniques has led to an increasing number of fluoroscopically guided procedures being done percutaneously such as vertebroplasty, which is the percutaneous cement augmentation of vertebral bodies. METHODS: Three months of occupational dose data for two spine surgeons was evaluated measuring the radiation doses to the thyroid gland, the upper extremities, and the eyes during vertebroplasty. RESULTS: The annual risk of developing a fatal cancer of the thyroid is 0.0025%, which means a very small to small risk. The annual morbidity (the risk of developing a cancer including nonfatal ones) is 0.025%, which already means a small to medium risk. The dose for the eye lens was about 8% of the threshold dose to develop a radiation induced cataract (150 mSv); therefore, the risk is very low but not negligible. The doses measured for the skin are 10% of the annual effective dose limit (500 mSv) recommended by the ICRP (International Commission on Radiologic Protection); therefore, the annual risk for developing a fatal skin cancer is very low. CONCLUSION: While performing percutaneous vertebroplasty, the surgeon is exposed to a significant amount of radiation. Proper surgical technique and shielding devices to decrease potentially high morbidity are mandatory. Training in radiation protection should be an integral part of the education for all surgeons using minimally invasive radiologic-guided interventional techniques.

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BACKGROUND: Endoderm organ primordia become specified between gastrulation and gut tube folding in Amniotes. Although the requirement for RA signaling for the development of a few individual endoderm organs has been established a systematic assessment of its activity along the entire antero-posterior axis has not been performed in this germ layer. METHODOLOGY/PRINCIPAL FINDINGS: RA is synthesized from gastrulation to somitogenesis in the mesoderm that is close to the developing gut tube. In the branchial arch region specific levels of RA signaling control organ boundaries. The most anterior endoderm forming the thyroid gland is specified in the absence of RA signaling. Increasing RA in anterior branchial arches results in thyroid primordium repression and the induction of more posterior markers such as branchial arch Hox genes. Conversely reducing RA signaling shifts Hox genes posteriorly in endoderm. These results imply that RA acts as a caudalizing factor in a graded manner in pharyngeal endoderm. Posterior foregut and midgut organ primordia also require RA, but exposing endoderm to additional RA is not sufficient to expand these primordia anteriorly. We show that in chick, in contrast to non-Amniotes, RA signaling is not only necessary during gastrulation, but also throughout gut tube folding during somitogenesis. Our results show that the induction of CdxA, a midgut marker, and pancreas induction require direct RA signaling in endoderm. Moreover, communication between CdxA(+) cells is necessary to maintain CdxA expression, therefore synchronizing the cells of the midgut primordium. We further show that the RA pathway acts synergistically with FGF4 in endoderm patterning rather than mediating FGF4 activity. CONCLUSIONS/SIGNIFICANCE: Our work establishes that retinoic acid (RA) signaling coordinates the position of different endoderm organs along the antero-posterior axis in chick embryos and could serve as a basis for the differentiation of specific endodermal organs from ES cells.

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Although abundant in well-differentiated rat thyroid cells, Rap1GAP expression was extinguished in a subset of human thyroid tumor-derived cell lines. Intriguingly, Rap1GAP was downregulated selectively in tumor cell lines that had acquired a mesenchymal morphology. Restoring Rap1GAP expression to these cells inhibited cell migration and invasion, effects that were correlated with the inhibition of Rap1 and Rac1 activity. The reexpression of Rap1GAP also inhibited DNA synthesis and anchorage-independent proliferation. Conversely, eliminating Rap1GAP expression in rat thyroid cells induced a transient increase in cell number. Strikingly, Rap1GAP expression was abolished by Ras transformation. The downregulation of Rap1GAP by Ras required the activation of the Raf/MEK/extracellular signal-regulated kinase cascade and was correlated with the induction of mesenchymal morphology and migratory behavior. Remarkably, the acute expression of oncogenic Ras was sufficient to downregulate Rap1GAP expression in rat thyroid cells, identifying Rap1GAP as a novel target of oncogenic Ras. Collectively, these data implicate Rap1GAP as a putative tumor/invasion suppressor in the thyroid. In support of that notion, Rap1GAP was highly expressed in normal human thyroid cells and downregulated in primary thyroid tumors.

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Sample preparation procedures for AMS measurements of 129I and 127I in environmental materials and some methodological aspects of quality assurance are discussed. Measurements from analyses of some pre-nuclear soil and thyroid gland samples and of a systematic investigation of natural waters in Lower Saxony, Germany, are described. Although the up-to-now lowest 129I/127I ratios in soils and thyroid glands were observed, they are still suspect to contamination since they are significantly higher than the pre-nuclear equilibrium ratio in the marine hydrosphere. A survey on all available 129I/127I isotopic ratios in precipitation shows a dramatic increase until the middle of the 1980s and a stabilization since 1987 at high isotopic ratios of about (3.6–8.3)×10−7. In surface waters, ratios of (57–380)×10−10 are measured while shallow ground waters show with ratios of (1.3–200)×10−10 significantly lower values with a much larger spread. The data for 129I in soils and in precipitation are used to estimate pre-nuclear and modern 129I deposition densities.

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Part 1: 1881-1888 On Some Points in the Etiology and Pathology of Ulcerative Endocarditis, 1881 On Certain Parasites in the Blood of the Frog, 1883 The Third Corpuscle of the Blood, 1883 On the Use of Arsenic in Certain Forms of Anaemia, 1886 Antifebrin, 1887 Case of Arterio-Venous Aneurism of the Axillary Artery and Vein of Fourteen Year's Duration, 1887 Typhilitis and Appendicitis, 1888 Part 2: 1889-1892 Annual Address - License to Practice 1889 Case of Syphiloma of the Cord of the Cauda Equina-Death From Diffuse Central Myelitis, 1889 On a Case of Simple Idiopathic Muscular Atrophy, Involving the Face and the Scapulo-Humeral Muscles, 1889 Note on Intra-Thoracic Growths Developing from the Thyroid Gland, 1889 On the Value of Laveran's Organisms in the Diagnosis of Malaria, 1889 On the Form of Convulsive Tic Associated with Corprolalia, Etc., 1890 A Case of Sensory Aphasia Word-blindness with Hemianopsia, 1891 Rudolf Virchow: The Man and the Student, 1891 The Healing of Tuberculosis, 1892 The Cold-Bath Treatment of Typhoid Fever, 1892 Part 3: 1893 Remarks on the Varieties of Chronic Chorea, and a Report Upon Two Families of the Hereditary Form, With One Autopsy, 1893 Note on Arsenical Neuritis Following the use of Fowler's Solution, 1893 Note on a Remarkable House Epidemic of Typhoid Fever, 1893 Cases of Sub-Phrenic Abscess, 1893 On Sporadic Cretinism in America, 1893 Notes on Tuberculosis in Children, 1893 Part 4: 1849-1895 Parotitis in Pneumonia, Case of Pericarditis Treated by Incision and Drainage, 1894 The Army Surgeon, 1894 Introductory Remarks to Course of Clinical Demonstrations on Typhoid Fever, 1894 Cancer of the Stomach with Very Rapid Course, 1895 Case of Sporadic Cretinism (Infantile Myxcedema) Treated Successfully with Thyroid Extract, 1895 Visible Contractile Tumour of the Pylorus Following Ulcer of the Stomach, 1895 On the Association of Enormous Heart Hypertrophy, Chronic Proliferative Peritonitis, and Recurring Ascites, with Adherent Pericardium, 1895 Teaching and Thinking the Two Functions of a Medical School, 1895 The Practical Value of Laveran's Discoveries, 1895 Part 5 1896 Addison's Disease, 1896 On Six Cases of Addison's Disease, 1896 Hemiplegia in Typhoid Fever Thomas Dover (of Dover's Powder) Physician and Buccaneer, 1896 John Keats The Apothecary Poet, 1896 On The Classification of the Tics or Habit Movements, 1896 The Cerebral Complication of Raynaud's Disease, 1896 Part 6: 1897 On Certain Features in the Prognosis of Pneumonia, 1897 Clinical Lecture on Mitral Stenosis - Sudden Death - Ball Thrombus in the Left Auricle, 1897 The Diagnosis of Malarial Fever, 1897 The Functions of a State Faculty (President's Address), 1897 A Clinical Lecture on The Ball-Valve Gall-Stone in the Common Duct, 1897 Pneumonia (Review of Cases studied), 1897 Internal Medicine as a Vocation, 1897 Back Notes

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Murine Hoxd-3 (Hox 4.1) genomic DNA and cDNA and Hoxa-3 (Hox 1.5) cDNA were cloned and sequenced. The homeodomains of Hoxd-3 and Hoxa-3 and regions before and after the homeodomain are highly conserved. Both Hoxa-3 and Hoxa-3 proteins have a proline-rich region that contains consensus amino acid sequences for binding to Src homology 3 domains of some signal transduction proteins. Northern blot analysis of RNA from 8- to 11-day-old mouse embryos revealed a 4.3-kb species of Hoxd-3 RNA, whereas a less abundant 3.0-kb species of Hoxd-3 RNA was found in RNA from 9- to 11-day-old embryos. Two species of Hoxd-3 poly(A)+ RNA, 4.3 and 6.0 kb in length, were found in poly(A)+ RNA from adult mouse kidney, but not in RNA from other adult tissues tested. Hoxd-3 mRNA was detected by in situ hybridization in 12-, 14-, and 17-day-old mouse embryos in the posterior half of the myelencephalon, spinal cord, dorsal root ganglia, first cervical vertebra, thyroid gland, kidney tubules, esophagus, stomach, and intestines.

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Thyrotropin is the primary hormone that, via one heptahelical receptor, regulates thyroid cell functions such as secretion, specific gene expression, and growth. In human thyroid, thyrotropin receptor activation leads to stimulation of the adenylyl cyclase and phospholipase C cascades. However, the G proteins involved in thyrotropin receptor action have been only partially defined. In membranes of human thyroid gland, we immunologically identified alpha subunits of the G proteins Gs short, Gs long, Gi1, Gi2, Gi3, G(o) (Go2 and another form of Go, presumably Go1), Gq, G11, G12, and G13. Activation of the thyrotropin (TSH) receptor by bovine TSH led to increased incorporation of the photoreactive GTP analogue [alpha-32P]GTP azidoanilide into immunoprecipitated alpha subunits of all G proteins detected in thyroid membranes. This effect was receptor-dependent and not due to direct G protein stimulation because it was mimicked by TSH receptor-stimulating antibodies of patients suffering from Grave disease and was abolished by a receptor-blocking antiserum from a patient with autoimmune hypothyroidism. The TSH-induced activation of individual G proteins occurred with EC50 values of 5-50 milliunits/ml, indicating that the activated TSH receptor coupled with similar potency to different G proteins. When human thyroid slices were pretreated with pertussis toxin, the TSH receptor-mediated accumulation of cAMP increased by approximately 35% with TSH at 1 milliunits/ml, indicating that the TSH receptor coupled to Gs and G(i). Taken together, these findings show that, at least in human thyroid membranes, in which the protein is expressed at its physiological levels, the TSH receptor resembles a naturally occurring example of a general G protein-activating receptor.

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The micronutrient selenium is essential to human physiology. As the amino acid selenocysteine, it is inserted into selenoproteins with a wide range of functions including antioxidant capacity, thyroid hormone metabolism, improvement of immune system, brain function, fertility and reproduction. Low selenium status has been associated with increased risk for chronic diseases, such as cancer, type-2 diabetes and cardiovascular disease. In this context, several studies have been conducted in order to investigate if selenium supplementation could reduce the risk of such diseases. However, genetic variations may interfere in the response of individuals to a dietary intervention and must be considered as a important source of inter-individual variation. Therefore, this study was conducted was conducted to investigate the influence of genetic variations in selenoproteins genes on the response to an intervention with Brazil nuts, the richest source of selenium known in nature. The study included 130 healthy volunteers with both genders, aged 20 to 60 years old selected in University of São Paulo. They received nuts for 8 weeks, eating one nut a day, and did a washout period for more 8 weeks. All volunteers had a blood sampling collection every 4 weeks during 4 months, in a total of 5. The following analysis were done: anthropometric measurements, lipid profile, plasma malondialdehyde, plasma and erythrocyte Se, selenoprotein P, plasma and erythrocyte GPx activity, gene expression of GPX1, SEPP1, SELS and SEP15. The volunteers were also genotyped for SNPs rs1050450, rs3811699, rs1800699, rs713041, rs3877899, rs7579, rs34713741 and rs5845. Each unit of Brazil nut provided an average of 300 µg of selenium. All 130 volunteers completed the protocol. The concentrations of total cholesterol and glucose decreased after 8 weeks of supplementation. Moreover, HDL concentrations were higher for carriers of the variant T allele for GPX4_rs713041. The frequencies of the variant genotypes were 5,4% for rs1050450, rs3811699 e rs1088668, 10% for rs3877899, 19,2% for rs713041 e rs7579, 11,5% for rs5845 and 8,5% for rs34713741. The levels of the five biomarkers increased significantly after supplementation. In addition, erythrocyte GPx activity was influenced by rs1050450, rs713041 and rs5845; erythrocyte selenium was influenced by rs5845 and plasma selenium by rs3877899. Gene expression of GPX1, SEPP1 and SEP15 were higher after supplementation. The SNP rs1050450 influenced GPX1 mRNA expression and rs7579 influenced SEPP1 mRNA expression. Therefore, it can be concluded that the supplementation with one of Brazil nut for 8 weeks was efficient to reduce total cholesterol and glucose levels and to increase the concentrations of the main biomarkers of selenium status in healthy adults. Furthermore, our results suggest that GPX4_rs713041 might interfere on HDL concentrations and GPx1 activity, GPX1_rs1050450 might interfere on GPx1 activity, SEP15_rs5845 might interfere on GPx1 activity and erythrocyte selenium and SEPP1_3877899 might interfere on plasma Se levels. Therefore, the effect of genetic variations should be considered in future nutritional interventions evaluating the response to Brazil nut supplementation.

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Trabalho Final do Curso de Mestrado Integrado em Medicina, Faculdade de Medicina, Universidade de Lisboa, 2014