Bone mineral density in well-differentiated thyroid cancer patients treated with suppressive thyroxine: a systematic overview of the literature.

BACKGROUND: The effects of subclinical hyperthyroidism on bone mineral density (BMD) induced by suppressive thyroxine therapy in patients with well-differentiated thyroid cancer (WDTC) remains unclear. An overview of the current literature was undertaken to evaluate studies to date. METHODS: A systematic medline search yielded a total of 11 studies appropriate for review which included premenopausal women, postmenopausal women, and men on suppressive thyroxine post thyroidectomy for WDTC. Main outcome measures were bone mineral density and bone turnover markers. CONCLUSIONS: Although studies were limited by small numbers and varying degrees of control for confounding variables, results suggested no significant change in bone mineral density for premenopausal women or men. Findings for postmenopausal women remain unclear with two of the best controlled studies reporting opposing results. Further studies for this population are recommended to help guide clinical practice.     

The effect of GM1 ganglioside on coerulospinal, noradrenergic, adult neurons and on fetal monoaminergic neurons transplanted into the transected spinal cord of the adult rat

GM₁ ganglioside, thyroxine and hydrocortisone were tested for their ability to improve the survival and growth of fetal focus coeruleus noradrenergic neurons in the transected, adult spinal cord. GM₁ alone was also tested for its effect on fetal mesencephalic dopaminergic neurons implanted into a small dorsolateral cavity at the L2 region of the cord previously transected at the T9–T10 region. None of the substances tested had any measurable effect on either of the fetal implants. However, in the GM₁- and thyroxine-treated animals the somatic dendrites of the axotomized, noradrenergic, coerulospinal neurons appeared more robust, and more intensely fluorescent, compared to their appropriate controls. GM₁ also caused a pronounced sprouting of the axotomized monoaminergic (catecholaminergic and serotonergic) fibres in the rostral region of the cord adjacent to the transection site. All of the mesencephalic dopaminergic implants survived in both the GM₁-treated animals and their saline-injected controls. However, their development was apparently not influenced by GM₁. The results indicate that GM₁ and thyroxine can enhance those aspects of the reactive mechanisms of mature, axotomized, noradrenergic coerulospinal neurons that promote their regeneration. As such, GM₁ could become a useful tool in current attempts to foster the regeneration of damaged monoaminergic neurons in the mammalian CNS.     

Thyroid toxicity due to subchronic exposure to a complex mixture of 16 organochlorines, lead, and cadmium.

The human population in the industrialized world is ubiquitously exposed to complex mixtures of persistent pollutants that contaminate food, water, and air. A large number of these contaminants have been shown to cause significant toxicity to the hypothalamic-pituitary-thyroid (HPT) axis in laboratory animal studies, through a variety of mechanisms, although these effects occur at levels of exposure greatly in excess of common human exposure. While many of the mechanisms of thyroid toxicity of these substances are potentially complementary, little is known of the degree of interaction of common persistent contaminants on responses of the HPT axis. To investigate the potential effects of a complex, environmentally relevant mixture on the HPT axis, sexually mature male rats were administered a mixture of 16 common organochlorines (dichlorodiphenoxytrichloroethane [DDT], p,p'-dichlorodiphenoxydichloroethylene [p,p'-DDE], hexachlorobenzene [HCB], tetrachlorodibenzo-p-dioxin [TCDD], polychlorinated biphenyls [PCBs], methoxychlor, endosulfan, heptachlor, hexachlorocyclohexane, dieldrin, aldrin, mirex, and several chlorinated benzenes, and metal contaminants [lead, cadmium]). The doses of the mixture that were administered were related to minimum risk levels or tolerable daily intakes of these substances, as derived by risk assessment with the 1x, 10x, 100x, and 1000x groups receiving mixture components at doses equivalent to 1x, 10x, 100x, or 1000x the minimum risk level (or tolerable daily intake, reference dose), respectively. After 70 daily treatments by gavage, endpoints related to circulating thyroid hormone (serum thyroxine [T(4)], triiodothyronine [T(3)], thyroid stimulating hormone [TSH], and serum T(3) uptake [T(3)-up]), thyroid gland histomorphology (thyroid follicle cross sectional area, epithelial height, follicle roundness or aspect ratio, colloid/epithelial ratio) and hepatic metabolism of thyroid hormone (UDP-glucuronyl transferase [UGT] and outer-ring deiodinase [ORD]) were assessed. All examined endpoints were significantly altered by the mixture albeit with great variability between endpoints in the sensitivity. While most endpoints examined did not show significant changes at mixture doses below 1000x, 2 endpoints, TSH and hepatic outer ring deiodinase activity, were significantly increased and decreased, respectively, by 1x dose and showed dose-related increases in severity with increasing dose. Median thyroid follicle cross sectional area was also increased by the lowest dose of the mixture but decreased with subsequent increases in dose until, at the highest dose, this parameter was significantly reduced relative to control. The relative sensitivity of endpoints of thyroid function in detecting toxicity of the mixture was TSH = ORD = median follicle area > T(3) > all other endpoints. These results demonstrate that low doses of ubiquitous environmental contaminants can alter HPT physiology in sexually mature males.     

Irreversible hypothyroidism following prolonged use of lithium

A 66-year-old white man developed hypothyroidism after 5 years of lithium therapy. The condition persisted after switching to carbamazepine. Thyroid hormone substitution improved the response to psychotropic drugs and has helped to maintain stable mood.     

Hyperthyroxinemia is positively associated with prevalent and incident type 2 diabetes mellitus in two population-based samples from Northeast Germany and Denmark

Background and Aims

A potential causal relationship between thyroid function and type 2 diabetes mellitus is currently under debate, but the current state of research is limited. Our aim was to investigate the association of thyroid hormone levels with prevalent and incident type 2 diabetes mellitus (T2DM) in two representative studies.

游离甲状腺素化学发光免疫分析方法的建立

目的 采用二抗-甲状腺素抗体固相两步包被法,使用鲁米诺-双氧水-辣根过氧化物酶化学发光体系作为检测体系,建立测定血清中游离甲状腺素的化学发光免疫分析方法.方法 利用竞争法建立游离甲状腺素的检测体系,分别对该体系进行分析性能评估、2016年度内分泌室间质评,并与进口全自动发光试剂盒检测结果进行一致性检验.结果在4~64pmol/L的校准曲线范围内相关系数0.9995,最低检出限为0.54pmol/L,批内和批间精密度均小于7.0%,稳定性结果良好,不影响检测结果.2016年全国室间质评测定结果均在允许范围内,与进口西门子发光试剂盒有很好的临床符合性,两种试剂盒的样本测值差异不具有统计学意义.结论 本方法利用二抗-甲状腺素抗体固相两步包被法,在节约包被原料的同时改善了精密度且提高了灵敏度,最后通过临床血样的一致性评价,与参比试剂盒具有同等的临床使用价值.     

An unmasking phenomenon in an observational post-licensure safety study of adolescent girls and young women

Our recent experience in a post-licensure safety study of autoimmune conditions following the quadrivalent human papillomavirus vaccine in 189,629 girls and young women ages 9-26 years led us to question the adequacy of the exclusion of Day 0 events to prevent the erroneous association of prevalent conditions with vaccination. Of the 18 confirmed cases of Graves' disease diagnosed in days 1-60 following vaccination, only 6 cases appeared to be truly new onset. Among the remaining 12 cases, 2 cases had abnormal thyroid stimulating hormone or thyroxine labs drawn prior to or on Day 0 but had no documented pre-existing symptoms. The other 10 cases had mention of symptoms of hyperthyroidism referencing a period prior to first HPV-4 dose. This 'unmasking' phenomenon, due to health care visits that include vaccination and new workups of preexisting symptoms, may not be adequately controlled through the exclusion of Day 0 events.     

喹硫平对精神分裂症患者糖脂代谢及内分泌的影响

目的：探讨喹硫平对精神分裂症患者血糖、血脂、甲状腺素及催乳素水平的影响。方法对40例精神分裂症患者口服喹硫平治疗,观察8周。于治疗前后监测患者血糖、血脂、甲状腺素及催乳素水平的变化。结果治疗8周末患者空腹血糖及催乳素无显著变化,三碘甲状腺原氨酸、游离甲状腺素较治疗前显著下降（P＜0．01）,三酰甘油较治疗前显著升高（P＜0．01）;甲状腺素与血清总胆固醇呈显著负相关（P＜0．05）,游离三碘甲状腺原氨酸与高密度脂蛋白胆固醇显著正相关（P＜0．05）。结论喹硫平对精神分裂症患者血糖、催乳素水平无明显影响;对甲状腺素及血脂水平均有不同程度的影响,且甲状腺素水平与脂代谢有一定的相关性。     

肺心病患者血清甲状腺素含量变化及其临床意义

目的探讨75例无甲状腺疾病的肺心病患者血清三碘甲状腺原氨酸(T3)、血清甲状腺素(T4)和血清促甲状腺激素(TSH)的含量变化及其关系.方法检测75例肺心病患者血清T3、T4和TSH含量,另选80例健康体检者作为正常对照组.结果肺心病患者血清T3降低,与正常对照组比较,P＜0.01,血清T4与正常对照组比较P＞0.05.有肺性脑病、消化道出血严重并发症时,低T3血症尤为显著,P＜0.01.且多伴有低T4血症,P＜0.05.血清T4血症越低,病死率越高.结论血清T3、T4含量可作为判断肺心病轻重和预后指标之一.