Effects of triiodothyronine on the development of GFAP-immunoreactivity and cat-activity in monolayer cultures of embryonal rat forebrain cells

Dose-dependent actions of triiodothyronine were studied in serum-containing primary cultures of embryonal rat forebrain cells. Triiodothyronine at concentrations exceeding the normal medium concentration by 2 and 5 nM failed to cause significant changes in the development of CAT-activity and GFAP-immunoreactivity. In the presence of additional 10 and 20 nM T₃, however, CAT-activity was increased and GFAP-immunoreactivity was decreased in comparison to cultures maintained with ‘normal’ (10% FCS-containing) media.     

SIL—2R和T3对ACST病情及预后的评估

目的 探讨重症急性胆管炎（ＴＣＳＴ）患者可溶性白细胞介素２受体（ＳＩＬ－２Ｒ）、三碘甲状腺原氨酸（Ｔ３）变化及意义。方法 采用酶联免疫吸附试验和放射免疫法研究了２７例ＡＣＳＴ（Ａ组）和１０８例单纯胆囊结石（Ｂ组）患者的ＳＩＬ－２Ｒ和甲状腺激素。结果 术前和术后Ａ组ＳＩＬ－２Ｒ显著高于Ｂ组（Ｐ〈０．０１），Ｔ３显著低于Ｂ组（Ｐ〈０．０１）。两例死亡ＡＣＳＴ患者ＳＩＬ－２Ｒ大于１０００Ｕ／ｍｌ，Ｔ３低     

Hormonal correlations at transition from reproduction to molting in an annual life cycle of Humboldt penguins (Spheniscus humboldti)

To understand the hormonal mechanism behind a unique strategy of breeding and molting in Humboldt penguins, six pairs of captive Humboldt penguins kept in an outdoor open display pen were observed and blood collected weekly for a year. They all molted between the middle of June and the middle of August within 10 days except one pair that molted about a month later. The late pair had been rearing a hatchling until July due to the successful second clutch after the first clutch failed. A peak of plasma levels of thyroxine and triiodothyronine, respectively, overlapped a period of molting in both sexes. Plasma testosterone concentrations in the males and females were lowest for two month during a period of pre-molt and molting. Plasma concentrations of estradiol were also lowest during the molt in both sexes. Except for the period of molting, sex steroid hormone concentrations were high although there was great individual variation. During the molt, the birds were forced to fast since they did not enter the pool in the display pen where they usually forage live fish. To compensate this forced fasting, they took more food than usual during pre-molting period and gained body mass to about 20% more than the baseline value. Increased flipper thickness was parallel to increased body mass indicating that the gained body mass attributed to fat reservoir. These data indicate that rapid molting in Humboldt penguins is correlated with a drastic increase and decrease of thyroid hormones during the period of lowest concentrations in sex steroid hormones.     

老年低三碘甲状腺原氨酸综合征患者血清三碘甲状腺原氨酸水平与冠状动脉病变的相关性分析

目的 探讨合并低三碘甲状腺原氨酸(T3)综合征的老年冠心病患者冠状动脉病变特点,并分析血清T3激素水平与冠状动脉病变的相关性.方法 选取符合低T3综合征诊断的老年冠心病患者986例为低T3组,游离T3(FT3)、游离甲状腺素(FT4)、促甲状腺激素(TSH)均正常的老年冠心病患者1074例为对照组.测定两组FT3、FT4、TSH水平,根据冠状动脉造影结果以病变支数及Gensini积分评价冠状动脉病变程度,分析血清T3水平与冠状动脉病变的相关性. 结果 低T3组患者年龄比对照组高(P＜0.05),总胆固醇及低密度脂蛋白胆固醇水平比对照组高(均P＜0.05).血清FT3值,低T3组低于对照组[(1.0±0.6) pmol/L与(4.1±0.5)pmol/L,P＜0.05)],血清FT4、TSH两组差异无统计学意义.低T3组Gensini总积分高于对照组[(43.5±18.3)分与(24.5±10.1)分,P＜0.05)].两组冠状动脉病变特点比较,低T3组中3支血管病变发生率高于对照组(P＜0.05).低T3组中,冠状动脉重度狭窄(3支主要血管任意1支狭窄超过75％)和完全闭塞(3支主要血管任意1支完全闭塞)发生率高于对照组(均P＜0.05).多因素Logistic回归分析结果显示,年龄和低FT3与冠状动脉病变支数及病变程度相关.结论 低T3综合征的老年冠心病患者以多支病变和双支病变为主,冠状动脉病变累及范围广、程度重.     

Low serum T3 levels are associated with false-positive results when using the risk of ovarian malignancy algorithm (ROMA) in women with benign ovarian disease

ObjectiveWe investigated factors that could cause false-positive results when using the risk of ovarian malignancy algorithm (ROMA) for assessing ovarian cancer risk.Materials and methodsROMA scores were calculated from patients followed surgery to remove a pelvic mass. We compared a false-positive group with a true-negative group of ROMA scores.ResultsWe analyzed 324 patients using medical records. There were 22 with an epithelial ovarian cancer (EOC), 15 with a borderline ovarian tumor, and 287 with benign disease. Twenty-nine (10.1%) of the patients with benign disease showed high-risk ROMA score (false positive) and 13/37 (35%) patients with EOC, or borderline ovarian tumor showed low ROMA scores (false negatives). The median serum triiodothyronine (T3) level of the false-positive ROMA group in patients with benign disease was lower than in the true-negative ROMA group (p < 0.001) and the estimated glomerular filtration rate (eGFR) was also lower (p = 0.001) in the false-positive ROMA group. Median serum T3 levels in the true-positive ROMA group among patients with EOC, or borderline ovarian tumor were lower than in the false-negative ROMA group (p = 0.043).ConclusionMedian serum T3 level and eGFR in the false-positive ROMA group in patients with benign ovarian disease were lower than in the true-negative group.     

Effects of triiodothyronine on morphology, growth behavior, and the actin cytoskeleton in mouse osteoblastic cells (MC3T3-E1)

We investigated the effects of thyroid hormone treatment on morphology, growth behavior, and cytoskeletal structures of long-term cultured MC3T3-El cells. Morphological investigations were carried out on native cells by phase contrast microscopy and on epon-embedded semithin sections. The area covered by the cell and matrix layers (tissue-like area), percent extracellular matrix, average height of tissue-like area, and length and height of single cells were measured histomorphometrically on the cross sections. F-actin was analyzed histochemically and quantitated after fluorochrome-labeled phalloidin staining using confocal microscopy and fluorometry. Significant differences between control and T₃-treated cells were found after confluency, but not in subconfluent cultures. Control cells continued to proliferate forming multilayers, and produced increasing amounts of extracellular matrix. In contrast, T₃-treated cells stopped to proliferate forming two cell layers at the maximum. These cells were flattened, distinctly enlarged, and polygonal in shape. Histochemical staining for F-actin revealed three different staining patterns, depending on the position of the cell within the multilayer of control cultures. Basal cells contained a large number of thick stress fibers in parallel arrangement. Intermediate cells exhibited only a few thick actin filament bundles located at the outermost periphery. The superficial cells were characterized by a large number of thin, parallel-oriented microfllament bundles extending across the entire cytoplasm. The actin pattern of T₃-treated cells resembled that of the basal cell layer of the control cells. The amount of F-actin increased with the prolonged T₃ treatment. We conclude from these data that the known specific cellular responses to T₃ treatment are accompanied by significant morphological alterations indicating pivotal effects of thyroid hormones on osteoblastic differentiation.     

Localization of thyroid hormone receptor β2 in the ventral medullary neurons that synthesize thyrotropin-releasing hormone

Altered thyroid statuses are associated with autonomic disorders. Thyrotropin-releasing hormone (TRH) synthesized in medullary raphe pallidus (Rpa), raphe obscurus (Rob) and the parapyramidal regions (PPR) regulates vagal and sympathetic preganglionic motoneurons. Hypothyroidism increased TRH gene expression and c-Fos immunoreactivity (IR) in these nuclei. Whether these increases represent a direct action of thyroid hormone was studied by detecting the presence of thyroid hormone receptor β2 (TRβ2) in pro-TRH-synthesizing neurons in the Rpa, Rob and the PPR using immunohistochemistry with specific TRβ2 antiserum and in situ hybridization with digoxigenin-labeled pro-TRH cRNA probe. TRβ2 IR was widely distributed throughout the medulla and primarily localized within the cell nuclei. Particularly intense immunostaining was presented in the Rpa, Rob and the PPR neurons. The combination of immunohistochemistry with in situ hybridization revealed that all pro-TRH mRNA-positive neurons in these ventral medullary nuclei were also TRβ2 IR positive. The numbers of TRβ2 IR-positive neurons in each nucleus were identical in both euthyroid rats and hypothyroid rats induced by 6-n-propyl-2-thiouracil in drinking water for 4 weeks. The finding that TRβ2 localized in pro-TRH-synthesizing neurons in the ventral medullary nuclei provides an anatomical substrate for a direct thyroid hormone action on these neurons in the regulation of TRH gene expression, which may contribute to the altered autonomic activity in different thyroid statuses.     

The effect of acute nicotine administration on plasma levels of the thyroid hormones and corticosterone in the rat

The effects of a single intraperitoneal injection of nicotine hydrogen tartrate (200 μg/kg) on the plasma levels of thyroxine, triiodothyronine and corticosterone were monitored over a 24 hour period. Nicotine did not alter the plasma levels of either of the thyroid hormones but did produce a significant increase in plasma corticosterone, an effect which peaked at 20 min post-injection and lasted for 45 min.     

甲状腺功能低下时大鼠脑内甲状腺激素受体的变化

用放射自显影术观察了甲状腺功能低下大鼠脑内甲状腺激素(T_3)受体的变化。结果表明:甲状腺功能低下时大鼠脑内T_3受体普遍增多,但各脑区增多的程度不同,大脑皮质、小脑、下丘脑及松果体等处受体的增多最为明显。本文还对脑内T_s受体的分布特点、功能意义及甲状腺功能低下时脑内T_3受体增多的原因进行了讨论。     

Ornithine decarboxylase activity in the isolated perfused rat heart.

Ornithine decarboxylase activity in rat hearts perfused by the Langendorff technique decreased by 50% after 1 h. Pyridoxal-5-phosphate, amino acids, cycloheximide, isoprenaline and insulin, when added to the perfusion medium, did not significantly affect myocardial ornithine decarboxylase activity. Growth hormone, T₃ and dibutyryl 3′,5′-cAMP were each able to prevent a loss of enzyme activity in hearts perfused for 1 h. When both T₃ and cycloheximide were added to the perfusion medium the ornithine decarboxylase activity was similar to that of hearts perfused with a medium containing T₃ alone. The results suggested that the biosynthesis of ornithine decarboxylase stopped with the onset of perfusion. The elevated enzyme activity after perfusion with growth hormone, T₃ or dibutyryl 3′,5′-cAMP was probably due to a decreased degradation of the enzyme protein.