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1.
Braz J Med Biol Res ; 52(10): e8491, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31618368

RESUMO

Considering the recognized role of thyroid hormones on the cardiovascular system during health and disease, we hypothesized that type 2 deiodinase (D2) activity, the main activation pathway of thyroxine (T4)-to-triiodothyronine (T3), could be an important site to modulate thyroid hormone status, which would then constitute a possible target for ß-adrenergic blocking agents in a myocardial infarction (MI) model induced by left coronary occlusion in rats. Despite a sustained and dramatic fall in serum T4 concentrations (60-70%), the serum T3 concentration fell only transiently in the first week post-infarction (53%) and returned to control levels at 8 and 12 weeks after surgery compared to the Sham group (P<0.05). Brown adipose tissue (BAT) D2 activity (fmol T4·min-1·mg ptn-1) was significantly increased by approximately 77% in the 8th week and approximately 100% in the 12th week in the MI group compared to that of the Sham group (P<0.05). Beta-blocker treatment (0.5 g/L propranolol given in the drinking water) maintained a low T3 state in MI animals, dampening both BAT D2 activity (44% reduction) and serum T3 (66% reduction in serum T3) compared to that of the non-treated MI group 12 weeks after surgery (P<0.05). Propranolol improved cardiac function (assessed by echocardiogram) in the MI group compared to the non-treated MI group by 40 and 57%, 1 and 12 weeks after treatment, respectively (P<0.05). Our data suggested that the beta-adrenergic pathway may contribute to BAT D2 hyperactivity and T3 normalization after MI in rats. Propranolol treatment maintained low T3 state and improved cardiac function additionally.


Assuntos
Tecido Adiposo Marrom/metabolismo , Antagonistas Adrenérgicos beta/administração & dosagem , Iodeto Peroxidase/metabolismo , Infarto do Miocárdio/metabolismo , Propranolol/administração & dosagem , Tiroxina/sangue , Tri-Iodotironina/sangue , Tecido Adiposo Marrom/efeitos dos fármacos , Animais , Modelos Animais de Doenças , Iodeto Peroxidase/efeitos dos fármacos , Masculino , Ratos , Ratos Wistar , Tiroxina/efeitos dos fármacos , Tri-Iodotironina/efeitos dos fármacos
2.
Zhonghua Jie He He Hu Xi Za Zhi ; 42(8): 591-595, 2019 Aug 12.
Artigo em Chinês | MEDLINE | ID: mdl-31378020

RESUMO

Objective: To explore the change of hypothalamic-pituitary-thyroid axis hormones and it's role in depression in obstructive sleep apnea-hypopnea syndrome. Methods: Seventy-three male OSAHS patients [age (39±11) years] and 13 male controls [age (36±7.5) years] were enrolled from August 2013 to May 2017 in the 1(st) Hospital of China Medical University. Overnight polysomnography and depression were assessed. The serum TRH, TSH, FT4 and FT3 levels were measured on the next morning. The relationship between depression and hypothalamic-pituitary-thyroid axis was analyzed. Results: Compared with the control group, severe hypoxia group had higher serum FT3 level [(4.5±0.6) ng/L vs. (5.4±0.7)ng/L, P<0.05)] and depression score (30±7 vs. 40±10, P<0.05). Further analysis revealed that serum FT3 level (5.0±0.5 ng/L vs. 5.5±0.7ng/L, P<0.05) and FT4 level [(16.2±1.9) ng/L vs. (18.2±2.3) ng/L, P<0.05] were lower in the patients with depression than those without. Conclusion: The decrease of serum FT3 and FT4 levels in OSAHS patients with severe hypoxia was closely related to the occurrence of depression.


Assuntos
Depressão/psicologia , Sistema Hipotálamo-Hipofisário/patologia , Apneia Obstrutiva do Sono/psicologia , Glândula Tireoide/patologia , China , Humanos , Masculino , Polissonografia , Apneia Obstrutiva do Sono/diagnóstico , Apneia Obstrutiva do Sono/fisiopatologia , Tireotropina/sangue , Tiroxina/sangue , Tri-Iodotironina/sangue
3.
JAMA ; 322(7): 632-641, 2019 08 20.
Artigo em Inglês | MEDLINE | ID: mdl-31429897

RESUMO

Importance: Maternal hypothyroidism and hyperthyroidism are risk factors for preterm birth. Milder thyroid function test abnormalities and thyroid autoimmunity are more prevalent, but it remains controversial if these are associated with preterm birth. Objective: To study if maternal thyroid function test abnormalities and thyroid autoimmunity are risk factors for preterm birth. Data Sources and Study Selection: Studies were identified through a search of the Ovid MEDLINE, EMBASE, Web of Science, the Cochrane Central Register of Controlled Trials, and Google Scholar databases from inception to March 18, 2018, and by publishing open invitations in relevant journals. Data sets from published and unpublished prospective cohort studies with data on thyroid function tests (thyrotropin [often referred to as thyroid-stimulating hormone or TSH] and free thyroxine [FT4] concentrations) or thyroid peroxidase (TPO) antibody measurements and gestational age at birth were screened for eligibility by 2 independent reviewers. Studies in which participants received treatment based on abnormal thyroid function tests were excluded. Data Extraction and Synthesis: The primary authors provided individual participant data that were analyzed using mixed-effects models. Main Outcomes and Measures: The primary outcome was preterm birth (<37 weeks' gestational age). Results: From 2526 published reports, 35 cohorts were invited to participate. After the addition of 5 unpublished data sets, a total of 19 cohorts were included. The study population included 47 045 pregnant women (mean age, 29 years; median gestational age at blood sampling, 12.9 weeks), of whom 1234 (3.1%) had subclinical hypothyroidism (increased thyrotropin concentration with normal FT4 concentration), 904 (2.2%) had isolated hypothyroxinemia (decreased FT4 concentration with normal thyrotropin concentration), and 3043 (7.5%) were TPO antibody positive; 2357 (5.0%) had a preterm birth. The risk of preterm birth was higher for women with subclinical hypothyroidism than euthyroid women (6.1% vs 5.0%, respectively; absolute risk difference, 1.4% [95% CI, 0%-3.2%]; odds ratio [OR], 1.29 [95% CI, 1.01-1.64]). Among women with isolated hypothyroxinemia, the risk of preterm birth was 7.1% vs 5.0% in euthyroid women (absolute risk difference, 2.3% [95% CI, 0.6%-4.5%]; OR, 1.46 [95% CI, 1.12-1.90]). In continuous analyses, each 1-SD higher maternal thyrotropin concentration was associated with a higher risk of preterm birth (absolute risk difference, 0.2% [95% CI, 0%-0.4%] per 1 SD; OR, 1.04 [95% CI, 1.00-1.09] per 1 SD). Thyroid peroxidase antibody-positive women had a higher risk of preterm birth vs TPO antibody-negative women (6.6% vs 4.9%, respectively; absolute risk difference, 1.6% [95% CI, 0.7%-2.8%]; OR, 1.33 [95% CI, 1.15-1.56]). Conclusions and Relevance: Among pregnant women without overt thyroid disease, subclinical hypothyroidism, isolated hypothyroxinemia, and TPO antibody positivity were significantly associated with higher risk of preterm birth. These results provide insights toward optimizing clinical decision-making strategies that should consider the potential harms and benefits of screening programs and levothyroxine treatment during pregnancy.


Assuntos
Doenças Autoimunes/diagnóstico , Iodeto Peroxidase/imunologia , Complicações na Gravidez/diagnóstico , Nascimento Prematuro/etiologia , Doenças da Glândula Tireoide/diagnóstico , Testes de Função Tireóidea , Adulto , Autoanticorpos/sangue , Doenças Autoimunes/sangue , Doenças Autoimunes/complicações , Feminino , Idade Gestacional , Humanos , Hipotireoidismo/complicações , Hipotireoidismo/diagnóstico , Recém-Nascido , Gravidez , Complicações na Gravidez/sangue , Doenças da Glândula Tireoide/sangue , Doenças da Glândula Tireoide/complicações , Tireotropina/sangue , Tiroxina/sangue
4.
J Zoo Wildl Med ; 50(2): 461-465, 2019 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-31260215

RESUMO

Congenital hypothyroidism (CH) in humans is most commonly caused by disruption of thyroid gland development (dysgenesis) or an inherited defect in thyroid hormone biosynthesis (dyshormonogenesis). CH has not been previously documented in great apes. This report describes the clinical presentation, diagnosis, and treatment of CH in a 9-mo-old male Bornean orangutan (Pongo pygmaeus) and a 6-wk-old female Sumatran orangutan (Pongo abelii). Primary CH due to thyroid dysgenesis was confirmed in the Bornean orangutan using sonography and radioisotope scintigraphy. Although commercial thyroid immunoassays are not validated for use in orangutans, in comparison to age-matched controls, thyroid-stimulating hormone level was markedly elevated, and serum thyroxine (T4) and free T4 levels were markedly decreased in both cases. Oral supplementation with levothyroxine sodium resulted in noticeable clinical improvement in both orangutans within 30 days of initiating treatment.


Assuntos
Doenças dos Símios Antropoides/congênito , Hipotireoidismo Congênito/veterinária , Pongo/classificação , Tiroxina/uso terapêutico , Envelhecimento , Animais , Doenças dos Símios Antropoides/tratamento farmacológico , Doenças dos Símios Antropoides/patologia , Hipotireoidismo Congênito/diagnóstico , Hipotireoidismo Congênito/tratamento farmacológico , Feminino , Masculino , Especificidade da Espécie , Tireotropina/sangue , Tiroxina/sangue
5.
Rev Assoc Med Bras (1992) ; 65(6): 830-833, 2019 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-31340312

RESUMO

OBJECTIVE: Even though stress has been long known as a provocative factor for Graves' disease, its relationship with Hashimoto's thyroiditis is more controversial. Studies on this topic are scanty. This paper aims to report a case of stress-induced Hashitoxicosis. RESULTS: Here we report a case of Hashitoxicosis induced by a psychological stressful event in a 28-year-old woman with Hashimoto's thyroiditis. She had remained stably euthyroid for 12 years. She was first observed in April 2016, while euthyroid. She came back after 11 months because of fatigue and palpitations, in the absence of neck pain. Thyroid function tests revealed moderate thyrotoxicosis (undetectable TSH; FT4 36.94 pmol/L, normal values 9.0-24.46; FT3 13.50 pmol/L, normal values 3.07-6.14) with negative TSH-receptor antibodies. In the previous three months, she had experienced a psychological stressful event. Inflammatory markers were negative, and the white cell count was normal. Thyroid ultrasound revealed a modest increase in vascularization. Transient subclinical hypothyroidism ensued after seven weeks and spontaneously recovered. On the last visit, the patient was still on euthyroidism. (TSH 1.01 mU/L; FT4 9.22 pmol/L; FT3 3.98 pmol/L). We also performed HLA serotyping and genotyping. CONCLUSION: This case demonstrates that, similarly to Graves' disease, Hashitoxicosis can also be triggered by stressful life events.


Assuntos
Antígenos HLA/genética , Doença de Hashimoto/psicologia , Estresse Psicológico/complicações , Adolescente , Feminino , Genótipo , Doença de Hashimoto/genética , Humanos , Sorogrupo , Estresse Psicológico/genética , Tireotropina/sangue , Tiroxina/sangue
6.
Environ Int ; 129: 389-399, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31150980

RESUMO

Serum perfluoroalkyl acids (PFAAs) have been linked to disruption of maternal thyroid hormone homeostasis, but results have varied between studies which we hypothesized was due to timing of the thyroid hormone measurements, variability in PFAA isomer patterns, or presence of other stressors. In a longitudinal study design, we investigated the time-dependency of associations between PFAA isomers and thyroid hormones during pregnancy and post-partum while considering thyroid peroxidase antibody (TPOAb) status and mercury (Hg) co-exposure. In participants of a prospective Canadian birth cohort (n = 494), free thyroxine (FT4), free triiodothyronine (FT3), thyroid stimulating hormone (TSH) and TPOAb were quantified in maternal plasma collected in each trimester and 3-months postpartum, and 25 PFAAs (15 linear and 10 branched) and Hg were quantified in samples collected during the second trimester. Perfluorohexane sulfonate (PFHxS) and total branched isomers of perfluorooctane sulfonate (PFOS) were positively associated with TSH in mixed-effect models, with strongest associations early in gestation. Throughout pregnancy and post-partum, PFHxS was inversely associated with FT4, consistent with elevated TSH, while Hg was inversely associated with FT3. In TPOAb-positive women, negative associations were found between PFUnA and FT4, and 1m-PFOS and TSH, supporting previous studies that thyroid disorder could increase susceptibility to PFAA-mediated hormone dysregulation. Hg did not confound associations but was a significant interaction term, revealing further positive associations between PFOS isomers (∑3m+4m-PFOS) and TSH. Higher perfluoroalkyl sulfonate exposures were associated with higher TSH and/or lower FT4, strongly suggestive that PFHxS and branched PFOS isomers are risk factors for subclinical maternal hypothyroidism. Isomer-specific analysis is important in future studies, as crude measures of 'total-PFOS' masked the associations of branched isomers. A concerning result was for PFHxS which had consistent negative associations with FT4 at all time points and a positive association with TSH in early pregnancy when fetal development is most sensitive to disruption.


Assuntos
Alcanossulfonatos/sangue , Poluentes Ambientais/sangue , Hipotireoidismo/induzido quimicamente , Complicações na Gravidez/induzido quimicamente , Hormônios Tireóideos/sangue , Adulto , Ácidos Alcanossulfônicos/sangue , Autoanticorpos/sangue , Canadá , Poluentes Ambientais/toxicidade , Feminino , Fluorcarbonetos/sangue , Humanos , Hipotireoidismo/sangue , Estudos Longitudinais , Gravidez , Complicações na Gravidez/sangue , Segundo Trimestre da Gravidez , Estudos Prospectivos , Tireotropina/sangue , Tiroxina/sangue , Tri-Iodotironina/sangue
8.
J Dairy Sci ; 102(7): 6679-6681, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31103299

RESUMO

Our previous published work demonstrated that feeding rumen-degradable valine to late-lactation dairy cows increased milk production compared with control-fed cows, with a response that was equivalent to that of recombinant bovine somatotropin. To further elucidate the response mechanism, we hypothesized that thyroxine (T4) and triiodothyronine (T3), which are important regulators of basal metabolism, may be involved. Previous short-term studies have demonstrated increased milk production when feeding iodinated casein. Eight multiparous Holstein dairy cows (255 ± 26.4 d in milk) were blocked by milk yield (34.1 ± 8.25 kg/d) and randomly assigned to 1 of 4 treatments using a replicated 4 × 4 Latin square design with 21-d periods (7 d for dietary adaptation and 14 d for data collection). Treatments were control (CON), a single injection of recombinant bovine somatotropin (rbST), and synthetic valine fed at 40 (V40) or 80 (V80) g/cow per day. Cows were fed a total mixed ration with a distillers dried grains carrier fed at 113.4 g/d containing no valine or added valine. Blood samples were collected twice during wk 2 and 3 of each period for T3 and T4 analysis. Concentrations of T4 (3.28, 3.90, 3.98, and 3.87 µg/dL for CON, rbST, V40, and V80, respectively) were increased for cows receiving rbST, V40, and V80 compared with CON cows. Concentrations of T3 (125.7, 140.7, 148.8, and 139.7 ng/dL) were increased for cows receiving rbST, V40, and V80 compared with CON cows, with cows receiving V40 having the highest T3 concentrations. In conclusion, feeding rumen-degradable valine increases plasma T4 and T3 concentrations, which would explain the mechanism leading to increased milk production.


Assuntos
Ração Animal , Bovinos/sangue , Dieta/veterinária , Tiroxina/sangue , Tri-Iodotironina/sangue , Valina/farmacologia , Animais , Feminino , Hormônio do Crescimento/administração & dosagem , Hormônio do Crescimento/metabolismo , Lactação/fisiologia , Leite , Distribuição Aleatória , Rúmen/metabolismo , Valina/administração & dosagem
9.
Am J Vet Res ; 80(6): 565-571, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31140852

RESUMO

OBJECTIVE: To investigate the effect of high doses of orally administered levothyroxine sodium (LT4) on serum concentrations of triiodothyronine (T3) and thyroxine (T4) in euthyroid horses. ANIMALS: 12 healthy adult horses. PROCEDURES: 10 horses initially received water (vehicle) or 240 mg (5X treatment) or 480 mg (10× treatment) of LT4, and blood samples were collected at baseline (0 hours) and 0.5, 1, 2, 4, 6, 8, 10, 12, 18, 24, 48, 72, 96, and 120 hours after treatment to measure serum T3 and T4 concentrations. Three horses then received 480 mg of LT4 for 14 days, and T4 concentration was measured on days 0, 14, 21, 28, and 35. Changes in T3 and T4 concentrations were compared over time and among treatments. RESULTS: One-time administration of LT4 resulted in variable but significant increases in both T3 and T4 concentrations for up to 120 hours; however, T3 and T4 concentrations rarely exceeded reference intervals with either treatment. Prolonged administration of 480 mg of LT4 resulted in a 15-fold increase in T4 concentration after 14 days, but concentration returned to day 0 values within 21 days after LT4 administration was discontinued. CONCLUSIONS AND CLINICAL RELEVANCE: In euthyroid horses, administration of a high dose of LT4 resulted in mild increases in thyroid hormone concentrations; however, prolonged administration of high doses of LT4 resulted in markedly increased thyroid hormone concentrations that returned to pretreatment values within 3 weeks after discontinuation of LT4 administration. These results indicated complex kinetics of LT4 and suggested a possible saturation of T4 excretion in euthyroid horses.


Assuntos
Cavalos/sangue , Tiroxina/farmacologia , Tri-Iodotironina/sangue , Animais , Relação Dose-Resposta a Droga , Feminino , Masculino , Valores de Referência , Hormônios Tireóideos/sangue , Tiroxina/sangue
10.
J Coll Physicians Surg Pak ; 29(6): 574-576, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31133159

RESUMO

An enlarging thyroid normally extends into the mediastinum, resulting in a presternal or substernal goiter, depending on its migration anteriorly or posteriorly, respectively. The first one was a rare entity in medical literature, being previously reported in only 6 cases worldwide. The present case reports a 54-year woman with a presternal goiter. She had a history of partial thyroidectomy due to a colloid goiter in 2004. Her thyroid function revealed subclinical hypothyroidism. No other abnormalities were present in physical exam or in laboratory tests. A resection of the remaining thyroid tissue was made, with great postsurgical recovery. The anatomopathological study revealed a colloid goiter. Such case porpoise is to remember physicians that unusual presentations of ordinary diseases can occur. This report differs on literature, which demonstrated that papillary thyroid carcinoma is the most important cause of presternal goiter. Moreover, unlike previous reports with normal thyroid function, this case is the only one reported with subclinical hypothyroidism.


Assuntos
Bócio/cirurgia , Glândula Tireoide/diagnóstico por imagem , Tireoidectomia/métodos , Transtornos de Deglutição/etiologia , Dispneia/etiologia , Feminino , Humanos , Hipotireoidismo/complicações , Pessoa de Meia-Idade , Tireotropina/sangue , Tiroxina/sangue , Tomografia Computadorizada por Raios X , Resultado do Tratamento , Ultrassonografia
11.
Arch Endocrinol Metab ; 63(4): 351-357, 2019 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-31038589

RESUMO

OBJECTIVE: In this study, we aimed to describe the prevalence and distribution of positive antithyroperoxidase antibodies (TPOAb) according to sex, age strata, and presence of thyroid dysfunction using baseline data from the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil). MATERIALS AND METHODS: Thyroid hormone tests were obtained from each study participant at baseline. Levels of thyroid-stimulating hormone (TSH) and free thyroxine (FT4) were measured using a third-generation immunoenzymatic assay. Antithyroperoxidase antibodies were measured by electrochemiluminescence and were considered to be positive when ≥ 34 IU/mL. RESULTS: The prevalence of TPOAb among 13,503 study participants was 12%. Of participants with positive TPOAb, 69% were women. Almost 60% of the individuals with positive TPOAb were white. The presence of positive TPOAb was associated with the entire spectrum of thyroid diseases among women, but only with overt hyperthyroidism and overt hypothyroidism in men. CONCLUSION: The distribution of positive TPOAb across sex, race, age, and thyroid function in the ELSA-Brasil study is aligned with the worldwide prevalence of positive TPOAb reported in iodine-sufficient areas. In women, the presence of TPOAb was related to the entire spectrum of thyroid dysfunction, while in men, it was only related to the occurrence of overt thyroid disease.


Assuntos
Anticorpos/sangue , Iodeto Peroxidase/sangue , Doenças da Glândula Tireoide/epidemiologia , Adulto , Distribuição por Idade , Idoso , Índice de Massa Corporal , Brasil/epidemiologia , Brasil/etnologia , Estudos Transversais , Grupo com Ancestrais do Continente Europeu/estatística & dados numéricos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prevalência , Distribuição por Sexo , Doenças da Glândula Tireoide/sangue , Tireotropina/sangue , Tiroxina/sangue
12.
BMJ ; 365: l2006, 2019 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-31088853

RESUMO

CLINICAL QUESTION: What are the benefits and harms of thyroid hormones for adults with subclinical hypothyroidism (SCH)? This guideline was triggered by a recent systematic review of randomised controlled trials, which could alter practice. CURRENT PRACTICE: Current guidelines tend to recommend thyroid hormones for adults with thyroid stimulating hormone (TSH) levels >10 mIU/L and for people with lower TSH values who are young, symptomatic, or have specific indications for prescribing. RECOMMENDATION: The guideline panel issues a strong recommendation against thyroid hormones in adults with SCH (elevated TSH levels and normal free T4 (thyroxine) levels). It does not apply to women who are trying to become pregnant or patients with TSH >20 mIU/L. It may not apply to patients with severe symptoms or young adults (such as those ≤30 years old). HOW THIS GUIDELINE WAS CREATED: A guideline panel including patients, clinicians, and methodologists produced this recommendation in adherence with standards for trustworthy guidelines using the GRADE approach. THE EVIDENCE: The systematic review included 21 trials with 2192 participants. For adults with SCH, thyroid hormones consistently demonstrate no clinically relevant benefits for quality of life or thyroid related symptoms, including depressive symptoms, fatigue, and body mass index (moderate to high quality evidence). Thyroid hormones may have little or no effect on cardiovascular events or mortality (low quality evidence), but harms were measured in only one trial with few events at two years' follow-up. UNDERSTANDING THE RECOMMENDATION: The panel concluded that almost all adults with SCH would not benefit from treatment with thyroid hormones. Other factors in the strong recommendation include the burden of lifelong management and uncertainty on potential harms. Instead, clinicians should monitor the progression or resolution of the thyroid dysfunction in these adults. Recommendations are made actionable for clinicians and their patients through visual overviews. These provide the relative and absolute benefits and harms of thyroid hormones in multilayered evidence summaries and decision aids available in MAGIC (https://app.magicapp.org/) to support shared decisions and adaptation of this guideline.


Assuntos
Hipotireoidismo/tratamento farmacológico , Hormônios Tireóideos/uso terapêutico , Adulto , Idoso , Índice de Massa Corporal , Tomada de Decisões , Técnicas de Apoio para a Decisão , Depressão/tratamento farmacológico , Depressão/etiologia , Fadiga/tratamento farmacológico , Fadiga/etiologia , Feminino , Humanos , Hipotireoidismo/sangue , Hipotireoidismo/complicações , Hipotireoidismo/diagnóstico , Qualidade de Vida , Hormônios Tireóideos/efeitos adversos , Tireotropina/sangue , Tiroxina/sangue , Incerteza
13.
Food Chem Toxicol ; 128: 212-222, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30991129

RESUMO

Perchlorate, as an oxidizer, has many applications such as explosives and pyrotechnics, especially in rocket propellants and missile motors. Because it was found in water including wells and drinking water in the US, its effect on human health was being noted. However, the reproductive toxic effect on perchlorate is still unclear. In present study, the effects of repeated exposure to perchlorate on reproductive toxicity were evaluated in Wistar rats. The rats were treated orally with perchlorate at doses of 0.05, 1.00 or 10.00 mg/kg body weight (b.w.) daily for 8 weeks. The levels of T3 and T4 hormones in the rat serum were detected by radioimmunoassay kit. The indexes of reproduction, percentage of organ in body weight (%) and frequency of abnormal sperm cells were also analyzed in this study. DNA damage in testicular cells was evaluated by Comet assay. The levels of MDA, GSH and SOD were examined in testicle tissues of rats by ELISA. The expression of c-fos and fas protein was examined in testicle tissues by immunohistochemistry. The results showed that perchlorate did not affect the body weight of rats. Perchlorate also significantly decreased indexes of live birth and weaning in the groups of 1.00 and 10.00 mg/kg, and viability index only in the 10.00 mg/kg group (P < 0.05). Perchlorate also significantly decreased the serum level of T3 in male rats of 1.00 and 10.00 mg/kg groups, increased the rate of sperm abnormality (10.00 mg/kg), potentially caused DNA damage in testicular cells and altered the status of oxidative stress in male rats. In addition, because of the increase in the expression of fas and c-fos protein in testicle tissues, perchlorate could induce apoptosis in spermatogenesis. Thus, these findings indicate that perchlorate could cause DNA damage in testicular tissues and reduce testicular spermatogenic ability, resulting in reproductive toxicity.


Assuntos
Percloratos/toxicidade , Compostos de Amônio Quaternário/toxicidade , Reprodução/efeitos dos fármacos , Animais , Ensaio Cometa , Dano ao DNA , Feminino , Masculino , Estresse Oxidativo/efeitos dos fármacos , Percloratos/administração & dosagem , Proteínas Proto-Oncogênicas c-fos/metabolismo , Compostos de Amônio Quaternário/administração & dosagem , Ratos , Ratos Wistar , Espécies Reativas de Oxigênio/metabolismo , Espermatogênese/efeitos dos fármacos , Testículo/efeitos dos fármacos , Testículo/metabolismo , Tiroxina/sangue , Tri-Iodotironina/sangue , Receptor fas/metabolismo
14.
Mol Med Rep ; 19(5): 4514-4522, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30942410

RESUMO

Thyroid stimulating hormone (TSH) consists of an α­subunit and a unique ß­subunit. The first in­frame TSHß splice variant produced by the cells of immune system was identified in 2009. The TSHß splice variant and native TSHß exhibit different expression profiles, and research has been conducted to elucidate the role of the TSHß splice variant in different diseases. However, understanding of the fundamental physiological characteristics of the TSHß splice variant is currently limited. To verify whether the TSHß splice variant has the potential to induce thyroid follicular cells to synthesize thyroid hormone, in vivo and in vitro stimulation experiments were conducted in the present study. A total of 60 C57BL/6 mice were divided into control­, 5 and 10 µg TSHß splice variant­treated groups at random. Mice were sacrificed at 0.5, 1 and 4 h after intraperitoneal injection, and serum levels of tri­iodothyronine (T3) and thyroxine (T4) were determined using a radioimmunoassay. Thyroid follicular cells were isolated from the thyroids of mice, and stimulated with 2 µg/ml TSHß splice variant. Supernatants were collected, and the levels of T3 and T4 were detected. The protein expression levels of the sodium­iodide symporter, thyroperoxidase and thyroglobulin in thyroid follicular cells were quantified using western blot analysis. To verify whether the TSHß splice variant expression was regulated by the hypothalamus­pituitary­thyroid (HPT) axis, similar to native TSHß, a total of 60 C57BL/6 mice were equally divided into control, 2 mg/kg T3 intraperitoneal injection and 0.05 mg/kg thyroid­releasing hormone intraperitoneal injection groups at random. Mice were sacrificed at 1 and 4 h after injection. Alterations in the expression of the TSHß splice variant in the pituitary, thyroid, peripheral blood leukocytes and spleen tissues were detected using western blot analysis. The present study demonstrated that the TSHß splice variant is not regulated by the HPT axis and may affect thyroid hormone synthesis. Modifications in the expression of the TSHß splice variant may occur in a uniquely regulated manner to provide peripheral immunological compartments with a source of activated cells, particularly under immune stress.


Assuntos
Hormônios Tireóideos/biossíntese , Tireotropina Subunidade beta/genética , Animais , Células Epiteliais/citologia , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/metabolismo , Feminino , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Processamento de RNA , Proteínas Recombinantes de Fusão/biossíntese , Proteínas Recombinantes de Fusão/isolamento & purificação , Proteínas Recombinantes de Fusão/farmacologia , Simportadores/metabolismo , Tireoglobulina/metabolismo , Glândula Tireoide/citologia , Glândula Tireoide/metabolismo , Tireotropina Subunidade beta/metabolismo , Tiroxina/sangue , Tri-Iodotironina/sangue
15.
Int J Pediatr Otorhinolaryngol ; 122: 12-17, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30928865

RESUMO

INTRODUCTION: The investigation of amplitudes of otoacoustic emissions in congenital hypothyroidism can provide information on cochlear function with more sensibility, when compared to other methods of auditory evaluation. AIM: To investigate cochlear function through the amplitude of distortion product otoacoustic emissions in individuals with congenital hypothyroidism and to correlate with clinical aspects. METHODS: An exploratory, analytical, cross-sectional study with a convenience sample, composed of 50 individuals with congenital hypothyroidism and a group of 42 individuals without the disease, mean age of 8.4 (±3.1) years. The subjects of the research were evaluated by means of tonal and speech audiometry, immittance and distortion product otoacoustic emissions (DPOAEs). Continuous variables were described as mean or median and standard deviation. The Spearman test evaluated the correlations between the variables. RESULTS: Otoacoustic emission amplitudes were significantly reduced in the exposed group, with congenital hypothyroidism, when compared to the group of individuals without the disease, especially in the medium frequencies. The Spearman test showed a slight correlation between the amplitude values of the otoacoustic emissions of some frequencies and the variables: disease time, diagnostic age, irregular serum free thyroxine hormone levels and thyroid stimulating hormone, especially in the condition of less treatment, whose correlation was negative. CONCLUSION: There was a correlation between the levels of signal amplitudes of otoacoustic emissions with clinical conditions and hormonal follow-up, suggesting probable subclinical auditory impairment in this population, as well as influence of some clinical aspects of congenital hypothyroidism on auditory function.


Assuntos
Doenças Cocleares/fisiopatologia , Hipotireoidismo Congênito/fisiopatologia , Emissões Otoacústicas Espontâneas , Audiometria de Tons Puros , Audiometria da Fala , Estudos de Casos e Controles , Criança , Pré-Escolar , Doenças Cocleares/etiologia , Hipotireoidismo Congênito/complicações , Estudos Transversais , Humanos , Tireotropina/sangue , Tiroxina/sangue
16.
BMC Genomics ; 20(1): 316, 2019 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-31023219

RESUMO

BACKGROUND: Though intensive genetic selection has led to extraordinary advances in growth rate and feed efficiency in production of meat-type chickens, endocrine processes controlling these traits are still poorly understood. The anterior pituitary gland is a central component of the neuroendocrine system and plays a key role in regulating important physiological processes that directly impact broiler production efficiency, though how differences in pituitary gland function contribute to various growth and body composition phenotypes is not fully understood. RESULTS: Global anterior pituitary gene expression was evaluated on post-hatch weeks 1, 3, 5, and 7 in male broiler chickens selected for high (HG) or low (LG) growth. Differentially expressed genes (DEGs) were analyzed with gene ontology categorization, self-organizing maps, gene interaction network determination, and upstream regulator identification to uncover novel pituitary genes and pathways contributing to differences in growth and body composition. A total of 263 genes were differentially expressed between HG and LG anterior pituitary glands (P ≤ 0.05 for genetic line-by-age interaction or main effect of line; ≥1.6-fold difference between lines), including genes encoding four anterior pituitary hormones. Genes involved in signal transduction, transcriptional regulation, and vesicle-mediated transport were differentially expressed and are predicted to influence expression and secretion of pituitary hormones. DEGs involved in immune regulation provide evidence that inflammation and response to cellular stressors may compromise pituitary function in LG birds, affecting their ability to adequately produce pituitary hormones. Many DEGs were also predicted to function in processes that regulate organ morphology and angiogenesis, suggesting pituitary gland structure differs between the divergently selected lines. CONCLUSIONS: The large number of DEGs within the anterior pituitary gland of birds selected for high or low body weight highlights the importance of this gland in regulating economically important traits such as growth and body composition in broiler chickens. Intracellular signaling, transcriptional regulation, and membrane trafficking are important cellular processes contributing to proper hormone production and secretion. The data also suggest that pituitary function is intimately tied to structure, and organization of the gland could influence hypothalamic and systemic metabolic inputs and delivery of hormones regulating growth and metabolism into peripheral circulation.


Assuntos
Galinhas/genética , Redes Reguladoras de Genes , Hipófise/metabolismo , Transcriptoma , Animais , Peso Corporal , Fenótipo , Hipófise/patologia , RNA Mensageiro/metabolismo , Tiroxina/sangue , Tri-Iodotironina/sangue
17.
Diabetes Res Clin Pract ; 151: 114-119, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30935929

RESUMO

PURPOSE: The objective of this study was to estimate the combined effect of serum ferritin (SF) concentration and free thyroxine (fT4) levels on the risk of gestational diabetes mellitus (GDM). METHODS: Women presented for antenatal care at a tertiary hospital in Shanghai, China were included in this study from December 2012 to March 2014. Women were divided into six groups according to the SF and fT4 level. Multiple logistical regression model was used to estimate odds ratio (OR) among different groups. Relative excess risk of interaction (RERI), the attributable proportion (AP) of the interaction and the synergy index (SI) were applied to evaluate the additive interaction of SF concentration and fT4 level. RESULTS: A total of 6542 qualifying pregnant women were included in this study. We observed that a high SF concentration in early pregnancy was related to an increased risk of GDM (OR = 1.21, 95%CI: 1.02-1.43); while a low fT4 level was not (OR = 1.18, 95%CI: 0.89-1.58). There is no addictive interaction between SF and fT4 level on the presence of GDM. CONCLUSIONS: The study suggests that only high serum ferritin concentration is associated with an increased risk of GDM in early pregnancy. The level of fT4 in early pregnancy might have no effect on the association between high SF and risk of GDM.


Assuntos
Diabetes Gestacional/sangue , Diabetes Gestacional/diagnóstico , Ferritinas/sangue , Testes de Função Tireóidea/métodos , Tiroxina/sangue , Adulto , Diabetes Gestacional/patologia , Feminino , Humanos , Gravidez , Primeiro Trimestre da Gravidez/sangue , Adulto Jovem
18.
Environ Health ; 18(1): 33, 2019 04 11.
Artigo em Inglês | MEDLINE | ID: mdl-30975138

RESUMO

BACKGROUND: Adequate maternal thyroxine (T4) concentrations during the first half of pregnancy are fundamental to the embryo's or fetus' neural development. Organophosphate pesticides (OP) can act as thyroid disruptors and genetic polymorphisms for paraoxonase 1 (PON1), an enzyme that detoxifies OP, could be involved in individual's susceptibility to them. We assessed the association between para-occupational exposure to pesticides, including OP, during pregnancy and maternal hypothyroxinemia, as well as the potential genetic susceptibility conferred by PON1 polymorphisms. METHODS: We analyzed information from 381 healthy pregnant women (< 17 gestational weeks), who lived in a floricultural region of Mexico where pesticides, including OP, are routinely used. Women who were para-occupationally exposed to pesticides were those whose partner had an occupation involving contact with these products. Thyroid-Stimulating Hormone (TSH) and free T4 concentrations were determined using ELISA, and hypothyroxinemia was defined as free T4 concentrations <0.76 ng/dL. PON1192QR, PON155LM and PON1-108CT polymorphisms were determined through Polymerase Chain Reaction (PCR). The association between para-occupational exposure and genetic polymorphisms and hypothyroxinemia was estimated using logistic regression models. RESULTS: One hundred and sixty two women (42.52%) were classified as para-occupationally exposed to pesticides. Hypothyroxinemia prevalence was 54%, and it was not significantly associated with pesticide para-occupational exposure (OR: 1.21 95% CI 0.75-1.94). Independently of para-occupational exposure, the likelihood of hypothyroxinemia was higher among women who were carriers of PON155MM than in those with PON155LL genotype (OR MM vs LL: 3.03; 95%CI 1.62, 5.70). PON1192 RR (OR RR vs QQ: 1.72; 95%CI 0.93, 3.17) and PON1-108TT (OR TT vs CC: 1.60; 95%CI 0.90, 2.70) genotypes were marginally associated with hypothyroxinemia. No significant interaction was observed between pesticides para-occupational exposure and PON1 polymorphisms. CONCLUSIONS: These results suggest that PON1 polymorphisms could affect thyroid function during pregnancy in women living in areas where pesticides, including OP, are routinely used. Low exposure variability in this population, could be a possible explanation for the lack of association between para-occupational exposure and thyroid function.


Assuntos
Arildialquilfosfatase/genética , Exposição Materna , Compostos Organofosforados , Praguicidas , Tireotropina/sangue , Tiroxina/sangue , Adolescente , Adulto , Agricultura , Feminino , Humanos , México , Polimorfismo Genético , Gravidez , Adulto Jovem
19.
BMC Neurol ; 19(1): 54, 2019 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-30953462

RESUMO

BACKGROUND: Serum triiodothyronine (T3) concentration was reported to be associated with the prognosis after acute ischemic stroke. The aim of this study was to evaluate the effect of age on the prognostic value of thyroid-related hormones after an acute ischemic stroke. METHODS: This was a retrospective study involving the review of 1072 ischemic stroke patients who had been consecutively admitted to the hospital within 72 h of symptom onset. Total triiodothyronine (T3), total thyroxine (T4), free T3, free T4, and thyroid-stimulating hormone (TSH) were assessed to determine their values for predicting functional outcome at the first follow-up clinic visits, which usually occurred 2 to 4 weeks after discharge from the hospital. RESULTS: A total of 768 patients were finally included in the study and divided into two age groups: a younger group (age < 65 years) and an older group (age ≥ 65 years). On univariate analysis, four factors-lower total T3, free T3 concentrations, higher scores on the National Institute of Health Stroke Scale (NIHSS) and the presence of atrial fibrillation-were associated with poor functional outcomes in both groups. In addition, older age, female gender, higher free T4, and lower TSH levels were also associated with poor function in the older group. On multiple logistic regression analysis, higher NIHSS scores (odds ratio [OR] =1.95; 95% confidence interval [CI], 1.66-2.30; P ≤ .001) and lower total T3 concentrations (OR = 0.06; 95% CI, 0.01-0.68; P = .024) remained independently associated with poor functional outcome in the older group. However, the independent association with poor function of lower total T3 was not confirmed in the younger group. CONCLUSIONS: The prognostic value of low total T3 is age-associated and more meaningful in an older population.


Assuntos
Biomarcadores/sangue , Isquemia Encefálica/sangue , Acidente Vascular Cerebral/sangue , Tri-Iodotironina/sangue , Fatores Etários , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Razão de Chances , Prognóstico , Estudos Retrospectivos , Acidente Vascular Cerebral/diagnóstico , Tireotropina/sangue , Tiroxina/sangue
20.
Medicine (Baltimore) ; 98(14): e15055, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30946351

RESUMO

In this study, we evaluated the association between thyroid echogenicity on ultrasonography (US) and thyroid function in pediatric and adolescent Hashimoto's thyroiditis (HT) patients.In 86 pediatric and adolescent HT patients, the association between echogenicity and thyroid function and microsomal autoantibody status was evaluated. Among patients with overt hypothyroidism, 89.2% (33/37) showed a US grade of 3 or 4. All of the patients at grade 4 presented with overt hypothyroidism. In contrast, 97.8% (44/49) of the patients with subclinical hypothyroidism or euthyroidism showed grades 1 or 2. Patients with increased thyroid-stimulating hormone titer also tended to have increased US grades (P < .001). In contrast, free thyroxine levels were significantly decreased with increasing US grade (P < .001).In conclusion, patients with higher US grades had decreased thyroid function (P < .001).


Assuntos
Doença de Hashimoto/diagnóstico por imagem , Doença de Hashimoto/fisiopatologia , Glândula Tireoide/diagnóstico por imagem , Ultrassonografia Doppler em Cores , Adolescente , Criança , Pré-Escolar , Progressão da Doença , Feminino , Doença de Hashimoto/classificação , Humanos , Masculino , Estudos Retrospectivos , Método Simples-Cego , Testes de Função Tireóidea , Tireotropina/sangue , Tiroxina/sangue
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