功能性促甲状腺激素受体在人微血管内皮细胞的表达

目的探讨促甲状腺激素受体(TSHR)在人微血管内皮细胞(HMEC-1)的表达及其活性。 方法体外培养HMEC-1,采用逆转录-聚合酶链反应(RT-PCR)法检测细胞TSHR mRNA的表达;将细胞接种在六孔板上,分空白对照组、低剂量组、中剂量组和高剂量组,空白对照组给予不含促甲状腺激素(TSH)的基础培养基培养,低剂量组、中剂量组和高剂量组分别给予0.10 U/L,1.00 U/L,10.00 U/L的TSH干预。24 h后采用酶联免疫吸附法(ELISA)检测细胞内环磷酸腺苷(cAMP)水平,研究HMEC-1细胞中的TSHR是否具有活性。显著性检验采用单因素方差分析,组间比较采用LSD-t法。 结果RT-PCR结果显示HMEC-1表达TSHR mRNA;ELISA结果显示TSH刺激HMEC-1后细胞内cAMP表达增加,低剂量组cAMP水平[(5.23±0.86)mmol/L]与空白对照组[(1.77±0.25)mmol/L]比较,差异有统计学意义(t＝3.47,P<0.01),并且此效应呈剂量依赖性(F＝92.36,P<0.01)。 结论HMEC-1细胞中存在TSHR,且该受体可与TSH特异性结合发挥作用。     

Identification of thyroid stimulating hormone receptor-specific T cells in Graves' disease thyroid using autoantigen-transfected Epstein-Barr virus-transformed B cell lines.

The importance of thyrotropin receptor (TSHR) agonist antibodies in the manifestations of Graves' disease (GD) is recognized. There are, however, no convincing reports of TSHR-specific T cells. We have previously cloned T cells specific for thyroglobulin and thyroid peroxidase (TPO) from GD lymphoid infiltrates and used autologous EBV-transformed B cell lines (EBVL) transfected with an expression vector encoding TPO to efficiently detect TPO-specific T cells. Here we used EBVL transfected with TSHR to seek TSHR-specific T cells in the GD infiltrates, after cloning the in vivo activated T cells without antigen. 3 out of 30 clones responded vigorously and reproducibly to EBVL-TSHR, with a mean stimulation index > 7. Their release of IL-2, IL-4, and IL-10 after stimulation with soluble anti-CD3 and phorbol ester was indistinguishable from the other clones from this thyroid. However, they produced relatively little IFN gamma (median IL-4/IFN gamma ratio of 0.80) compared with the other clones (median IL-4/IFN gamma ratio 0.06). Thus, this new potent method of antigen presentation, using autoantigen-transfected EBVL, has permitted the first unequivocal identification of TSHR T cells in GD thyroid, with distinct Th0/Th2 characteristics, unlike previously cloned TPO-responsive cells which have Th1 characteristics.     

促甲状腺激素抑制疗法在分化型甲状腺癌治疗中的作用

目的探讨促甲状腺激素(TSH)抑制疗法在分化型甲状腺癌患者术后治疗中的作用。方法 130例分化型甲状腺癌患者于甲状腺切除术后分别行TSH抑制治疗(观察组)和甲状腺素替代治疗(对照组),比较2组患者术后无复发和/或无转移率。结果观察组术后3、5、10年的无复发和/或无转移率分别为98.76%、93.21%及79.54%,对照组分别为92.17%、82.36%及51.25%,2组差异有统计学意义(P<0.05)。结论 TSH抑制疗法是分化型甲状腺癌患者行全或近全甲状腺切除术后的有效治疗手段。     

早孕期孕妇促甲状腺激素检测临床意义研究

目的：探讨孕21-三体综合征胎儿、孕18-三体综合征胎儿和孕健康胎儿孕妇早孕期血清促甲状腺激素（TSH）水平和游离β-人绒毛膜促性腺激素（β-hCG）之间的关系,评价TSH用于早孕期产前筛查的临床价值。方法分别比较26例孕21-三体综合征胎儿、19例孕18-三体综合征胎儿和6782例孕健康胎儿孕妇孕11～13周时的血清TSH和游离β-hCG水平。结果孕21-三体综合征胎儿孕妇血清 TSH 水平较低（0．72＆#177;0．31MoM）,而孕18-三体综合征胎儿孕妇血清TSH水平较高（1．48＆#177;0．57 MoM）。孕健康胎儿孕妇血清TSH和游离β-hCG水平具有负相关性（r＝-0．214,P＜0．05）,但在孕染色体非整倍体胎儿孕妇体内,二者无相关性（孕21-三体综合征胎儿孕妇：r＝-0．157,P＞0．05;孕18-三体综合征胎儿孕妇：r＝-0．176,P＞0．05）。结论早孕期筛查 TSH 并不能有效提高21-三体综合征胎儿和18-三体综合征胎儿的检出率。     

The effects of endocrine-disrupting chemicals on thyroid hormone binding to Xenopus laevis transthyretin and thyroid hormone receptor.

We investigated the effects of medical, industrial and agricultural chemicals on 3,3',5-L-[125I]triiodothyronine ([125I]T3) binding to purified recombinant Xenopus laevis (X. laevis) transthyretin (xTTR), a plasma thyroid hormone-binding protein, and to the ligand-binding domain of thyroid hormone receptor-beta (xTR LBD). xTTR derived from X. laevis serum had about 80 times higher affinity for T3 than for L-thyroxine. The xTTR's relative affinities for diethylstilbestrol, pentachlorophenol and ioxynil were 10(-1)- to 10(-2)-fold less than that for T3. However, all chemicals investigated had either a weak or no influence on [125I]T3 binding to xTR LBD. The concentration of diethylstilbestrol, the most potent chemical, required for 50% inhibition of [125I]T3 binding to xTR LBD was 10(4) times greater than that of unlabeled T3. These results indicate the existence of several chemicals that interact with xTTR but not with xTR LBD.     

Thyroid hormone concentrations and inhibition of thyroid stimulating hormone secretion in euthyroid subjects with autonomous thyroid nodules

Abstract. Sixty-four euthyroid patients with autonomous thyroid nodules and normal thyroxine (T₄) concentrations and tri-iodothyronine resin uptake have been studied. The serum tri-iodothyronine (T₃) concentration of the patients was 2.24 (±0.67) ng/ml, significantly higher than in a group of fifty-seven euthyroid control subjects (1.58 ± 0.30 ng/ml). When no extranodular tissue was visible on the basal thyroid scan, the T₃ was 2.31 (±0.63) ng/ml, significantly higher than in patients with some extranodular uptake on the basal scan (1.91 ± 0.42 ng/ml). There was no significant difference in the serum T₄ concentrations of the patients (7.37 ± 2.10 μg/100 ml) compared to the control group (6.88 ± 1.89 μg/100 ml). The T₄ concentrations were not correlated with total or partial inhibition of the extranodular tissue. The thyroid hormone concentrations were not directly correlated to the size of the nodule assessed by scan imaging. The thyroid stimulating hormone (TSH) concentration of the patients (1.52 ± 0.38 μU/ml) was significantly lower than in normals (2.49 ± 0.96 μU/ml). No significant difference was found in the TSH concentrations of patients with partial or total inhibition of extranodular tissue irrespective of the T₃ concentration. A thyrotrophin releasing hormone stimulation test in twelve patients did not increase the serum TSH, irrespectively of the T₃ concentration.
These data show the high frequency of elevated serum T₃ concentrations despite normal serum T₄ concentration in euthyroid patients with autonomous thyroid nodules. They confirm that inhibition of TSH secretion can occur when thyroid hormone concentrations are in the normal range.     

Functional sensitivity of seven automated thyroid stimulating hormone immunoassays

BackgroundSerum thyroid stimulating hormone (TSH) measurements are useful for detecting clinical and subclinical primary hypo- and hyperthyroidism in ambulatory patients. For diagnosis of hyperthyroidism, the functional sensitivity (FS) is an important performance criterion, and current guidelines recommend an FS of ≤ 0.02 m IU/l for “third” generation performance.MethodsWe evaluated TSH FS for the Access 2, Advia Centaur, Architect i2000, Dimension ExL Modular Analytics E170, Immulite 2000 and Dimension Vista 1500 automated immunoassays using serum pools tested over a 6 week period using 2 reagent lots and 2 calibrations. FS was determined by fitting a power function to the imprecision data using KaleidaGraph software.ResultsThe FS (m IU/l) for Access 2, ADVIA Centaur, ARCHITECT i2000, Dimension ExL, Modular Analytics E170, Immulite 2000, and Dimension Vista 1500 systems were determined to be 0.039, 0.006, 0.007, 0.003, 0.008, 0.003, and 0.003, respectively. The lowest and next to lowest pools had overall mean TSH concentrations of 0.012 m IU/l and 0.020 m IU/l, respectively and a range of concentrations of 0.005 to 0.022 m IU/l and 0.007 to 0.077 m IU/l, respectively.ConclusionsAll assays showed excellent performance in FS consistent with a “third” generation claim except for the Access 2 system. Further harmonization of TSH immunoassays is required, especially at lower concentrations.     

甲状腺过氧化物酶抗体和孕妇甲状腺功能障碍的筛查

目的探讨产前孕妇甲状腺过氧化物酶抗体和促甲状腺素筛查的重要性。方法根据甲状腺功能测定结果,将孕妇分为甲状腺功能紊乱组(Ⅰ组)53例,非甲状腺功能紊乱组(Ⅱ组)49例,采用电化学方法检测孕妇血清TPO-Ab和甲状腺激素TSH水平。结果Ⅰ组TOP-Ab阳性率高达79.24%,Ⅱ组TOP-Ab阳性率高达10.20%;47例孕妇TPOAb阳性,其中有10例TSH异常(21.3%),55例TPOAb阴性,其中4例TSH异常(7.5%)。结论 TPOAb阳性孕妇甲状腺功能紊乱明显增加,TPOAb阳性孕妇的甲状腺功能有向亚临床甲状腺功能减退的趋势。     

Genotyping of resistance to thyroid hormone in South American population. Identification of seven novel missense mutations in the human thyroid hormone receptor β gene

Thyroid Hormone Receptor β (THRB) defects, typically transmitted as autosomal dominant traits, cause Resistance to Thyroid Hormone (RTH). We analyzed the THRB gene in thirteen South American patients with clinical evidence RTH from eleven unrelated families. Sequence analysis revealed seven novel missense mutations. Four novel mutations were identified in exon 9. The first, a c.991A>G transition which originates a substitution of asparagine by aspartic acid (p.N331D). The second nucleotide alteration consists of a guanine to cytosine transversion at position 1003 (c.1003G>C) and results in substitution of the alanine at codon 335 by proline (p.A335P). The third mutation, a c.1022T>C transition produces a change of leucine by proline (p.L341P). The fourth mutation detected in exon 9 was a c.1036C>T transition which replaces the leucine at codon 346 by phenylalanine (p.L346F). The sequencing of the exon 10 detected three novel missense mutations. The first, a c.1293A>G transition changing isoleucine 431 for methionine (p.I431M). The second, the cytosine at position 1339 was replaced by adenine (c.1339C>A) resulting in the replacement of proline by threonine (p.P447T). The third mutation detected in exon 10 was a c.1358C>T transition resulting in the substitution of proline at codon 453 by leucine (p.P453L). Finally, sequencing analysis of the THRB gene revealed three substitutions previously described (p.A268G, p.P453T and p.F459C). The p.P453T was found in two patients.In conclusion, we report thirteen patients with RTH caused by heterozygous mutations of the THRB gene. Seven of the identified mutations correspond to novel substitutions.     

Establishment of a serum thyroid stimulating hormone (TSH) reference interval in healthy adults. The importance of environmental factors, including thyroid antibodies.

It has previously been shown that thyroid antibodies affect thyroid stimulating hormone (TSH) concentrations in men and women and that TSH levels are predictive of future thyroid disease. We investigated the validity of the National Academy of Clinical Biochemistry (NACB) guidelines regarding the TSH reference interval by studying 1512 individuals. Two hundred and fifty had at least one thyroid antibody, 121 were taking medications other than estrogens and occasional analgesics, and 105 reported a family history of thyroid disease. Serum TSH, thyroid peroxidase antibodies (TPOab) and thyroglobulin antibodies (Tgab) were determined on AutoDELFIA and TSHRab by a radioreceptor assay (RRA) from Brahms Diagnostica. For individuals without thyroid antibodies and other risk factors, no effect of age and gender was seen for serum TSH. Neither medication nor the presence of Tgab alone had any influence on serum TSH. TPOab alone or in combination with Tgab were associated with an increased serum TSH level. The 'cumulative percentage distributions' of subgroups, as well as the combined population, was In-Gaussian distributed. The central 95% of the population was within the 95% CI in rankit-plots. Consequently, a common reference interval for serum TSH of 0.58-4.07 mlU/l for all adults between 17 and 66 years of age was established. This reference interval is much higher than expected from the NACB-guidelines.     

A neuroendocrinological study in female migraineurs: prolactin and thyroid stimulating hormone responses

To evaluate the change of the neurotransmitter function in migraine, a neuroendocrinological study was performed in eleven female migraineurs and nine female controls. Thyrotropin releasing hormone, luteinizing hormone releasing hormone, and insulin were simultaneously loaded (the Triple test). Before and after loading, serum glucose, prolactin (PRL), thyroid stimulating hormone (TSH), luteinizing hormone, follicle stimulating hormone, adrenocorticotropic hormone, cortisol, human growth hormone and beta-endorphin were measured. The Triple test produced an increase of PRL in both migraine and control groups, but in migraineurs the increase was significantly larger than in controls. TSH also increased in response to the test, but the TSH response in patients was less than in controls, although not significantly so. The responses of other substances showed no significant differences between the two groups. Although dopaminergic hypofunction in migraine has been proposed by some authors, the present findings rather suggest a serotonergic hyperfunction.     

Thyroid hormone resistance syndrome. Inhibition of normal receptor function by mutant thyroid hormone receptors.

Thyroid hormone (T3) resistance is inherited in most cases in an autosomal dominant manner. The disorder is characterized by elevated free thyroid hormone levels and partial resistance to thyroid hormone at the cellular level. Distinct single amino acid substitutions in the ligand binding domain of the beta form of the thyroid hormone receptor have been described in two kindreds with this disorder. We used transient expression assays to characterize the functional properties of these receptor mutants, one containing a Gly to Arg change at amino acid 340 (G340R) and the other a Pro to His change at amino acid 448 (P448H). A nine amino acid carboxy terminal deletion (delta 448-456), analogous to an alteration that occurs in v-erbA, was also studied for comparison with the mutations that occur in the T3 resistance syndrome. None of the receptor mutants were able to mediate thyroid hormone dependent activation (TreTKCAT) or repression (TSH alpha CAT) of reporter genes when compared with the wild type receptor. In addition, the mutants inhibited the activity of normal alpha and beta receptor isoforms when examined in coexpression assays. This activity, referred to as dominant negative inhibition, was manifest with respect to both the positively and negatively regulated reporter genes. Although mutant receptor binding to DNA was unaffected, ligand binding studies showed that the G340R and delta 448-456 mutants failed to bind T3, whereas the P448H mutant bound hormone with reduced affinity (approximately 10% of normal) compared to the wild type receptor. Consistent with this finding, the P448H mutant receptor was partially active at higher T3 concentrations. Furthermore, the dominant negative inhibition elicited by the P448H receptor mutant at higher T3 concentrations was reversed in the presence of high doses of T3. These findings indicate that mutant beta receptors in patients with thyroid hormone resistance have reduced affinity for T3 and are functionally deficient, but impair the activity of normal receptors, thereby providing a mechanism for the dominant mode of inheritance in this disorder.     

Serum thyroxine, triiodothyronine and thyroid stimulating hormone after prolonged heavy exercise

Serum thyroxine (T4), triiodothyronine (T3) and thyroid stimulating hormone (TSH) was measured before, immediately after and on the following days after a 70 km cross-country ski race in two groups of ten well-trained men, one aged 21--29 years, taking 5.01--7.03 h, and one aged 51--57 years, taking 6.07--7.38 h. T4 was definitely increased immediately after the race, but fell to below the initial level on the following day and was not restored to the pre-race level until 4 days after the race. T3 showed essentially the same pattern, though less pronounced, a major part of the changes being possibly due to plasma volume variations. TSH showed a tendency to rise immediately after the race, but rose further to 175% of the initial level on the following day and was not restored to the initial level 4 days after the race. The pattern of changes were independent of age. It is suggested that the prolonged rise in TSH is probably due to an exercise-induced increased peripheral need for thyroid hormone.