Thyroid hormone induction of an autocrine growth factor secreted by pituitary tumor cells

Thyroid hormones stimulate the rate of cell division by poorly understood mechanisms. The possibility that thyroid hormones increase cell growth by stimulating secretion of a growth factor was investigated. Thyroid hormones are nearly an absolute requirement for the division of GH4C1 rat pituitary tumor cells plated at low density. Conditioned media from cells grown with or without L-triiodothyronine (T3) were treated with an ion exchange resin to remove T3 and were tested for ability to stimulate the division of GH4C1 cells. Conditioned medium from T3-treated cells was as active as thyroid hormone at promoting GH4C1 cell growth but did not elicit other thyroid hormone responses, induction of growth hormone, and down-regulation of thyrotropin-releasing hormone receptors, as effectively as T3 did. A substance or substances associated with T3-induced growth stimulatory activity migrated at high molecular weight at neutral pH and was different from known growth-promoting hormones induced by T3. The results demonstrate that thyroid hormones stimulate the division of GH4C1 pituitary cells by stimulating the secretion of an autocrine growth factor.     

甲状腺结节诊疗规范探讨

甲状腺结节是内分泌系统的常见病,发现甲状腺结节后需行影像学检查如B超等证实其客观存在,然后结合患者的症状、体征、实验室检查、影像学特点及细胞病理学检查结果以明确甲状腺结节性质,甲状腺结节诊断的关键是良、恶性的鉴别,对指导治疗具有非常重要的意义。良性结节选用手术、左甲状腺素（levothyroxine,L-T4）、¹³¹I、经皮酒精注射及中医中药等治疗,恶性结节可选用手术、¹³¹I、抑制促甲状腺激素（thyroid stimulating hormone,TSH）等治疗。     

Spot14基因研究进展

甲状腺激素响应Spot14蛋白(THRSP)是一种分子量较小的酸性蛋白,该蛋白能够对甲状腺激素迅速响应。Spot14基因在脂肪生成调控中起重要作用,是参与控制脂肪生成酶活性的转录因子。文章对该基因的结构、表达及其功能等方面的研究进展进行了综述。     

中华蟾蜍蝌蚪变态过程中甲状腺的组织学变化

【目的】研究中华蟾蜍(Bufo gargarizans)蝌蚪在不同发育阶段甲状腺的组织学变化。【方法】以处于变态高峰前后5期（28,33,38,42,46期）的中华蟾蜍蝌蚪为试验材料,用Motic BA300光学显微镜对各个发育时期蝌蚪的甲状腺进行组织学观察,测定蝌蚪的全长、体质量和肝质量等形态指标,并分析这些形态指标与甲状腺直径、滤泡平均直径及最大直径的线性相关性。【结果】在28期时,中华蟾蜍蝌蚪甲状腺出现但无分泌甲状腺激素的功能;33期时,甲状腺具备了分泌甲状腺激素的能力;此后甲状腺进一步发育,在蝌蚪前肢展开期甲状腺活性达到最强;至尾完全吸收期,甲状腺机能减弱。蝌蚪全长、体质量及肝质量与甲状腺直径及滤泡直径呈正线性相关。【结论】具有分泌机能的甲状腺出现的发育时期,与两栖动物变态类型相关;分泌高峰期出现的发育时期与幼体持续时间密切相关。中华蟾蜍蝌蚪的全长可以直观地反映其甲状腺的机能活性。     

氟对大鼠甲状腺结构和功能的影响

为探讨氟化物对大鼠甲状腺结构和功能的影响,将80只SD大鼠分为4组,每组20只,第1组为对照组,其他3组为低、中、高氟组,饮水中添加的氟化钠含量分另9为50、100、200mg·L^-1,饲养150d,复制氟中毒大鼠模型。制备甲状腺组织切片,观察甲状腺结构变化;采集大鼠血液,测定血清中TSH、FT3、FT4水平。结果成功地复制出大鼠氟中毒模型。光镜下可见氟中毒大鼠甲状腺滤泡增多,胶质浓集,间质毛细血管明显增生,甲状腺组织出现明显的增生性结节。与对照组相比,各氟中毒组TSH水平不同程度升高,其中高氟组升高显著（P〈0.05）;血清FT4水平与对照组相比高氟组显著降低（P〈0.05）。由此可知,氟化物可引起甲状腺胶质性及结节性肿大,并导致甲状腺代谢功能异常。     

比目鱼类的眼睛移位和不对称的进化起源

比目鱼类外形不对称产生的机制引起人们兴趣已逾一个多世纪。从比目鱼类(鲽形目)的类群和分布、变态过程中眼睛移位机械力的来源、甲状腺激素调控眼睛移位的信号通路、比目鱼类外形左右不对称与内脏左右不对称两者调控机制之间的关系以及比目鱼类眼睛左右不对称的进化起源等5个方面,系统地介绍了比目鱼类变态发育过程中眼睛移位的研究历史。重点介绍了本实验室提出的关于眼睛移位的组织学模型,以及眼睛移位信号调控途径的最新研究进展。发现并证明眶下皮肤组织细胞分裂导致眼睛移动,而眼睛移动进一步导致额骨变形,纠正了以往假说的谬误。最后,对比目鱼类眼睛移位和不对称进化起源进行了探讨,提出了解释比目鱼类不对称进化起源的新假说。     

Mammary carcinoma: enzymatic block in disialoganglioside biosynthesis

The sialyl transferase of disialoganglioside formation is depressed in mammary tumors induced in the rat by 7,12-dimethylbenz[a]anthracene. Specific activities of other glycosyltransferases of the pathway ceramide to monosialo-ganglioside are unchanged or elevated so that the ganglioside GM(1) accumulates and higher gangliosides are depressed. These findings with a solid tumor are critical to an involvement of gangliosides in the cell-surface changes of tumorigenesis.     

褐牙鲆早期发育阶段CRH基因表达及 受甲状腺激素的影响

[目的]探析褐牙鲆仔鱼早期发育阶段促肾上腺皮质激素释放激素基因(CRH)的表达情况及受甲状腺激素的影响作用,为开展牙鲆的人工繁育提供科学依据.[方法]通过实时荧光定量PCR检测褐牙鲆早期发育阶段CRH基因表达量,以ELISA测定褐牙鲆仔鱼甲状腺激素(T3和T4)水平,并测定经外源T3浸泡处理后早期发育褐牙鲆仔鱼CRH基因表达量的变化情况,探究CRH和甲状腺激素在褐牙鲆早期发育阶段的影响及作用关系.[结果]1~8日龄褐牙鲆仔鱼CRH基因相对表达量呈先升高后降低的变化趋势,在5日龄达最高值,显著高于其他日龄的仔鱼(P<0.05,下同).10~42日龄褐牙鲆仔鱼CRH基因主要在其头部表达,尾部CRH基因的相对表达量随着生长发育的进程而逐渐增加.褐牙鲆仔鱼变态前期甲状腺激素T4含量逐渐增加,变态高峰期迅速升高,在变态后期呈下降趋势.较其他早期发育时期,甲状腺激素T3在褐牙鲆变态期维持高水平,但含量低于甲状腺激素T4.22日龄褐牙鲆仔鱼经50 nmol/L外源T3处理2 h后,其头部和尾部CRH基因的相对表达量显著升高;但以外源T3处理8 h后,无论是头部还是尾部,CRH基因的相对表达量均呈显著下降趋势.[结论]褐牙鲆早期变态发育需CRH基因高表达及甲状腺激素积累,二者对褐牙鲆早期变态发育阶段具有重要作用并呈互相代偿效应.     

Glycoproteins: isolation from cellmembranes with lithium diiodosalicylate

A glycoprotein has been extracted in water-soluble form from human red cell membranes with lithium diiodosalicylate. After extraction of the membranes and phosphocellulose chromatography a homogeneous preparation is obtained which was 60 percent carbohydrate and 40 percent protein (by weight). The preparation contains AB and MN blood group antigens, receptors for influenza virus, and various phytohemagglutinins.     

Herpesvirus antigens on cell membranes detected by centrifugation of membrane-antibody complexes

Herpesviruses specify new glycoproteins that bind to cell membranes and also appear in the envelope of the virion. Incubation of purified smooth membranes from infected cells with antiviral antibody results in an increase in the density of the membranes as determined by flotation in sucrose density gradients. The magnitude of this increase depends on the amount of antibody used; densities as high as 1.16 grams per cubic centimeter have been obtained (the density of the untreated membranes is 1.08 grams per cubic centimeter). Antiviral antibody does not increase the density of uninfected cell membranes nor do saline or normal rabbit serum change the densities of infected or uninfected cell mnembranes. Viral antigens-presumably the glycoproteins specified by the virus-are probably on the surface of the infected cell membranes and bind to them strongly enough to withstand the hydrodynamic forces applied to them in the sucrose gradient.     

柑橘果实囊衣发育与化渣性的形成

【目的】揭示柑橘果实囊衣发育和化渣性形成的规律,为改良柑橘果实化渣性品质提供理论依据。【方法】以‘爱媛30’杂柑、‘诺瓦’杂柑、‘兴津’温州蜜柑、‘园丰’脐橙、‘纽荷尔’脐橙、‘安江’香柚和‘江永’香柚等不同类型柑橘果实为材料,在细胞及生理生化水平通过比较不同类型柑橘果实囊衣的超微结构、发育过程中囊衣的发育规律,分析囊衣细胞壁主要生理生化指标。【结果】不同类型柑橘果实囊衣均表现出外侧面粗糙而内侧面光滑的特征;囊衣内侧面表面蜡质层明显,其下1—2层细胞排列整齐、细胞壁增厚,囊衣细胞排列致密度由内侧面向外侧面逐渐降低。内侧面蜡质层及其下1—2层细胞形态变化、排列特征的显现是囊衣发育成熟的标志。柚类果实囊衣最厚、化渣性最差,主要原因是其囊衣细胞层数多、细胞体积大、果胶含量高。果实发育过程中,不同柑橘类型果实在花蕾至落花期,其子房内部已分化出心室,未来形成囊衣的心室间隔细胞大小一致且排列紧密,尚无明显的囊衣细胞排列特征。随着果实的膨大及成熟,‘沙田柚’（Citrus grandis Osbeck cv. Shatianyou）果实囊衣发育成熟后细胞壁增厚期最长,厚度最厚且细胞层数多,果胶含量显...     

甲状腺球蛋白免疫组化对甲状腺肿瘤的诊断价值

用免疫组化A B C法对60例甲状腺病理标本进行了甲状腺球蛋白检查,结果表明源于甲状腺滤泡上皮细胞的肿瘤,均呈阳性或弱阳性反应。大部分甲状腺癌呈弱阳性反应。作者认为甲状腺球蛋白可作为鉴别甲状腺滤泡上皮细胞源性与非滤泡上皮细胞源性的良好标记。     

Identification of a thyroid hormone receptor that is pituitary-specific

Three cellular homologs of the v-erbA oncogene were previously identified in the rat; two of them encode high affinity receptors for the thyroid hormone triiodothyronine (T3). A rat complementary DNA clone encoding a T3 receptor form of the ErbA protein, called r-ErbA beta-2, was isolated. The r-ErbA beta-2 protein differs at its amino terminus from the previously described rat protein encoded by c-erbA beta and referred to as r-ErbA beta-1. Unlike the other members of the c-erbA proto-oncogene family, which have a wide tissue distribution, r-erbA beta-2 appears to be expressed only in the anterior pituitary gland. In addition, thyroid hormone downregulates r-erbA beta-2 messenger RNA but not r-erbA beta-1 messenger RNA in a pituitary tumor-derived cell line. The presence of a pituitary-specific form of the thyroid hormone receptor that may be selectively regulated by thyroid hormone could be important for the differential regulation of gene expression by T3 in the pituitary gland.     

Influenza virus effects on cell membrane proteins

During infection by influenza virus, viral proteins become firmly attached to (or part of) host cell plasma membrane, nuclear membranes, mitochondrial, and microsomal membranes. Purified virus particles contain less than I percent host cell protein. Virus envelope proteins completely replace host membrane proteins in those discrete spots on the plasma membrane from which progeny virions bud out.     

Thyroid hormone influence upon lung surfactant metabolism

Thyroid administration and thyroidectomy in the rat profoundly affect the morphological characteristics of the type II pneumonocyte and the quantitative harvest of lung surfactant obtained from alveolar washings. The correlation of the ultrastructural changes with quantitative alterations in lung surfactant is evidence that the lamellar bodies within this cell are the source of the surface-active phospholipids utilized at the air-liquid interphase of lung alveoli. Our findings suggest that in the rat, L-thyroxine may be a potent regulator of lung surfactant metabolism.     

Cyclic guanosine and adenosine 3',5'-monophosphates in canine thyroid: localization by immunofluorescence

When guanosine 3',5'-monophosphate (cyclic GMP) and adenosine 3',5'-monophosphate (cyclic AMP) are localized in canine thyroid by a flurescence Immunocytochemical procedure, distinct staining patterns for each nucleotide are seen: Cyclic AMP is distributed throughout the follicular cell cytoplasm before and after administration of thyroid-stimulating hormone, while cyclic GMP is localized to the follicular cell mumbrane in the control state, and increased cytoplasmic fluorescence is visualized after acetylcholine. These data provide histological evidence that correlates with cyclic nucleotide tissue measurements, sugesting diverse roles of the two nucleotides in thyroid function.     

Direct evidence that endogenous GM1 ganglioside can mediate thymocyte proliferation

The B subunit of cholera toxin, which is multivalent and binds exclusively to a specific ganglioside, GM1, was mitogenic for rat thymocytes. When exposed to the B subunit, the cells proliferated, as measured by 3H-labeled thymidine incorporation. Mitogenesis depended on the direct interaction of the B subunit with GM1 on the surface of the cells. This demonstrates that endogenous plasma membrane gangliosides can mediate proliferation in lymphocytes.     

番鸭(Cairina moschata)甲状腺的显微与亚微结构

番鸭甲状腺实质由大小不一、近似球形的滤泡组成,其上皮细胞呈低立方形至扁平形.电镜下的滤泡上皮细胞,胞质内存在多量由被吞饮的胶状质与溶酶体相结合的胶质滴,线粒体外围有以核糖体规律排列的粗面内质网,网腔内多被低密度的无定形内容物所扩大.番鸭甲状腺实质存在滤泡旁细胞(C细胞).经Ehrlich苏木素染色的滤泡旁细胞呈球形、体积大、染色较浅,单个散在或2个并列位于滤泡外围的结缔组织内,不与滤泡腔接触,可明显与滤泡上皮细胞相区别.     

牙鲆胚后发育过程中Ⅰ型脱碘酶基因的原位表达谱

甲状腺激素T3在鱼类胚后发育与变态发育过程中发挥着重要作用,甲状腺激素T4通过Ⅰ型甲状腺氨酸脱碘酶(Dio1)生成T3,因此,调查Dio1基因在胚后发育包括变态发育过程中原位表达谱,有助于理解T3在胚后发育中的具体作用。利用RNA整体原位杂交技术,发现Dio1主要在牙鲆肠道、鳃、肝、肌肉、鳍、眼睛周围等器官和组织表达,鳃、肠道、奇鳍中的Dio1原位表达谱有一定的规律性,尤其在生骨肌细胞向鳍褶中迁移、臀鳍和背鳍(包括冠状幼鳍)的鳍条和支鳍骨的发生过程中,Dio1可能通过影响这些组织器官的T3水平而发挥重要作用。