碘过量大鼠仔鼠垂体促甲状腺激素细胞的组织学研究

目的探讨不同剂量碘过量对大鼠20日龄仔鼠垂体促甲状腺激素细胞的形态学影响。方法将断乳1个月的Wistar大鼠,雌雄各半,随机分为4组：NI组、10HI组、50HI组、100HI组。饲养3个月的雌雄大鼠1：1合笼交配产生仔鼠,断乳后的仔鼠喂养同上述大鼠。测定20日龄仔鼠垂体TSH细胞的体密度和面数密度。结果100HI组仔鼠垂体TSH细胞的体密度高于NI组,10HI、50HI与NI组相比无差异,各碘过量组的面数密度与NI组相比也无差别。结论大剂量碘过量可造成大鼠仔鼠乖体TSH细胞分泌颗粒蓄积,细胞体积增大。     

碘缺乏或碘过量对小鼠子二代生长发育的影响

目的探讨碘缺乏和碘过量所致的甲状腺功能低下对小鼠子二代生长发育的影响。方法将断乳1个月Baldb／c小鼠,随机分为5组（LI,NI,5HI,10HI,50H1）。给以不同浓度碘水喂养3个月后,连续传二代。观察碘缺乏和碘过量对子二代小鼠生长发育的影响。结果20日龄时,各组子二代鼠与NI组相比,LI组与50HI组的T4明显降低;LI组的体重明显降低,50HI组体重、身长、尾长、胸腺、脾均明显降低,脑相对重量增加。40日龄时,各组子二代鼠与NI组相比,LI组T4明显降低;碘缺乏组的体重、身长、胸腺、脾、肾上腺的重量均明显降低,脑相对重量明显增加;50HI组体重、身长、尾长明显降低。结论碘缺乏,高剂量碘过量均可引起甲状腺功能低下,使子二代鼠的生长发育延迟。碘缺乏对生长发育的影响比碘过量更为明显。但小鼠对碘过量有较强的耐受性,当碘摄入量为正常的50倍时,才会影响下一代的生长发育。     

碘过量对后代鼠脑NSE和GFAP表达的影响

目的观察碘过量对后代鼠神经元特异性烯醇化酶和胶质纤维酸性蛋白表达的影响。方法将断乳后一个月Wistar大鼠随机分为五组（NI、5HI、10HI、50HI和100HI）,饮用不同浓度的碘水,饲养3个月后雌雄合笼,取第二代60日龄鼠,测量血清甲状腺激素值,以NSE和GFAP为观察指标,研究后代鼠大脑的发育情况。结果各碘过量组甲状腺激素水平呈下降趋势,100HI组呈明显甲低状态;NSE的免疫组化和形态计量学显示：海马CA3区NSE阳性细胞的NA、VV,和灰度值随碘过量的严重程度而呈下降趋势,在100HI组呈明显的统计学差异。各组GFAP阳性星形胶质细胞阳性显色强弱未见明显不同。结论大鼠对碘摄入量的增高,只有在100HI组可以观察到以NSE表达降低为主要特点的脑发育障碍,其发病机理可能与碘过量所致的甲状腺功能低下有关。     

不同碘摄入水平对小鼠子二代鼠甲状腺功能和形态学的影响

目的研究不同碘摄入水平对小鼠子二代鼠甲状腺功能和形态学的影响。方法将断乳1个月Balb/c小鼠随机分为5组：低碘组LI、适碘组NI、5倍高碘组5HI、10倍高碘组10HI、50倍高碘组50HI。给以不同浓度碘水[〈0.25μg（LI）、1.5μg（NI）、7.5μg（5HI）、15μg（10HI）、75μg（50HI）]喂养3个月后,连续传2代。各组子二代鼠20,40日龄时处死,采用放射免疫法测定血清甲状腺激素水平,并作甲状腺形态学观察,用图文分析系统测定甲状腺滤泡的体视学参数：滤泡平均面积（SA）、滤泡腔平均面积（SB）、上皮细胞层厚度（L）和滤泡腔体积与滤泡体积之比（VA）,以期为甲状腺结构改变提供定量依据。结果 20日龄时,与NI组相比,LI组与50HI组T4明显降低;40日龄时,与NI组相比,LI组T4明显降低。形态学观察,NI组甲状腺多为中等大小滤泡,上皮细胞多为单层立方状;LI组甲状腺呈明显的滤泡增生,上皮呈柱状多为复层;50HI组甲状腺与适碘组比较,上皮细胞变扁平,腔内蓄积大量胶质。体视学参数测定：LI：L,SA均明显增大,VA明显减低;5HI组和10HI组与NI组比较各项指标之间均无统计学差异。50HI组,L明显减低,SA,SB,VA均明显增大。结论碘缺乏及高剂量碘过量均可引起子二代鼠的甲状腺功能低下。碘缺乏时子二代小鼠发生了明显的滤泡增生性甲状腺肿;高碘摄入时子二代小鼠发生了胶质蓄积性甲状腺肿,但肿大程度远不及缺碘所致的肿大。子二代小鼠对碘过量有较强耐受性,当碘摄入量为正常50倍时,才会明显影响到甲状腺的形态。     

甲状腺激素对胸腺上皮细胞CK19蛋白表达的影响

目的探讨甲状腺激素对胸腺的发育的影响及可能的机制。方法将12只怀孕4d的大鼠随机分成A组和B组,A组正常饮水,B组孕鼠供以含有0．02％甲巯咪唑的饮水制备仔鼠甲状腺功能低下动物模型,将A组的仔鼠随机分成对照组和甲状腺素钠组,将B组的仔鼠随机分成甲低组和甲低＋甲状腺素钠组。甲状腺素钠组和甲低＋甲状腺素钠组于出生后15d给予腹腔注射甲状腺素钠（0．5mg／kg体重,1次／d）,连续给药25d。所有动物于出生后40d麻醉处死,测定仔鼠的胸腺重量及脏器指数;采用放射免疫技术测定仔鼠血清中三碘甲状腺原氨酸（triiodothyronine,T3）、四碘甲状腺原氨酸（tetraiodothyronine,T4）、促甲状腺激素（thyroid—stimulating hormone,TSH）水平,免疫组织化学技术检测胸腺上皮细胞细胞角蛋白19（cytokeratin 19,CK19）蛋白的表达量。结果与对照组比较,甲状腺素钠组仔鼠血清中T3、T4显著升高,TSH减少,胸腺重量增大;甲低组仔鼠血清中T3、T4明显降低,TSH显著增高,胸腺重量降低,胸腺上皮细胞CK19蛋白表达减少。与甲低组比较,甲低＋甲状腺素钠组仔鼠血清中T3、T4升高,TSH降低,胸腺指数增大,胸腺上皮细胞CK19蛋白的表达明显增多。结论甲状腺激素可以通过影响胸腺上皮细胞CK19的表达量,使胸腺发育或退化。     

MiR-124对先天性甲低新生鼠神经元凋亡的影响

目的:探讨mi R-124在甲状腺功能低下新生大鼠海马神经元凋亡中的作用。方法:将16只孕SD雌鼠随机分为实验组和对照组,分别于两组仔鼠1、5、10、15日龄称重取血,用化学发光法测定血清游离三碘甲状腺原氨酸(FT3)、血清游离甲状腺素(FT4)及促甲状腺激素(TSH)水平。将大鼠用2%戊巴比妥钠腹腔注射麻醉后,固定在脑立体定位仪,处死后收集其海马,应用荧光定量PCR和免疫荧光技术检测agomir的干预效率,确定干预有效后进行建模。观察注射后大鼠行为学改变,NeuN染色法检测海马区脑组织神经元细胞凋亡情况。结果:实验组血清TSH水平明显高于对照组,而FT3、FT4水平明显低于对照组。同正常对照组相比,甲状腺功能减退组中阳性神经元数量明显减少、细胞轮廓模糊、不清晰。经mir-124模拟处理后,神经细胞的数量和形态明显改善。结论:mi R-124对先天性甲状腺功能低下新生鼠神经元凋亡起到保护作用。     

儿童单纯性肥胖小鼠模型的制作

目的通过调整窝仔数的方法建立幼儿单纯性肥胖模型,并与高脂饲料制备模型进行比较。方法48只雌性KM小鼠产仔鼠后,一半仔鼠数目为14～16只,一半仔鼠调整为6只（雌雄各3只）。仔鼠离乳时或第9周时仔鼠分别饲喂普通饲料或高脂饲料。仔鼠在15周后处死,称重,测量体长、腰围,生殖器重、脂肪重（肾周和生殖器周脂肪）,计算体脂比。结果①BD2组常规饲料饲喂至15周结束后,无论雌雄仔鼠,其体重与BDl组比较差异均有显著性（P〈0．05）,且BD2组体重超过BD1组体重雌性为26．3％,雄性为20．0％。同一处理方式,雌性仔鼠体脂比均高于雄性。②不同时间饲喂高脂饲料,无论调整窝仔数与否,高脂饲料各组仔鼠,无论雌雄,其各组仔鼠体重均比BD1组高（P均〈0．05）;HFD4组雌性和雄性仔鼠体重与BD2组相比差异均存在显著性（P〈0．05）。结论通过调整窝仔数的方法可以成功制备儿童单纯性肥胖模型。在儿童早期肥胖的情况下,成年后过度高脂饮食会导致机体储存更多的脂肪。     

邻苯二甲酸酯染毒哺乳期母鼠对雄性仔鼠睾丸Leydig细胞形态及功能的影响

目的:观察邻苯二甲酸二乙基己基酯(DEHP)对哺乳期雄性仔鼠睾丸子Leydig细胞(PLC)形态和功能的影响及作用机制。方法:SD孕鼠20只,随机均分为4组(n=5):正常对照组,低剂量组,中剂量组,高剂量组。仔鼠出生第1天起分别以0、10、100、750 mg/(kg·d)DEHP灌胃染毒母鼠,直到仔鼠出生后21 d。用化学发光法检测雄性仔鼠血清睾酮(T)水平;测量体重、睾丸重量、肛生殖器距离(AGD);光镜及电镜下观察睾丸Leydig细胞形态结构;免疫组化方法检测睾丸类固醇激素合成急性调节蛋白(St AR)表达;Real-time PCR法检测睾丸胰岛素样生长因子Ⅰ(IGF-Ⅰ)mRNA的表达。结果:与正常组比较,低剂量组T无明显变化,中、高剂量组血清T水平明显降低(P0.01)。低剂量组睾丸重量增加(P0.05),高剂量组睾丸重量、仔鼠体重明显下降(P0.01);中、高剂量组AGD明显缩短(P0.01)。低剂量组睾丸Leydig细胞明显增生,呈簇状分布;中、高剂量组睾丸Leydig细胞灶区轻度增生,高剂量组部分生精小管生精细胞层次减少、生精细胞凋亡并脱落。电镜观察各给药组Leydig细胞胞浆脂质颗粒减少,线粒体、内质网减少。低剂量组IGF-ⅠmRNA表达增高(P0.05);中、高剂量组睾丸St AR蛋白表达降低(P0.05)。结论:哺乳期染毒DEHP可干扰仔鼠PLC的睾酮合成,St AR蛋白的降低和Leydig细胞的损伤可能是其机制。     

术前血清促甲状腺激素水平与甲状腺结节相关性的研究

目的:探讨术前血清促甲状腺激素(TSH)水平与甲状腺结节良恶性的关系。方法:回顾性分析了1499例甲状腺结节手术切除患者术前血清TSH、甲状腺B超,手术记录、术后病理诊断报告。根据术后病理报告判定甲状腺结节良恶性,分析术前血清TSH水平在甲状腺良恶性结节中的不同分布。结果:分化型甲状腺癌(DTC)患者术前血清TSH水平明显高于甲状腺良性结节组(2.179±2.017vs1.259±0.884μIU/mL),P<0.001;在DTC患者中,有淋巴结转移较无淋巴结转移、TNM分期III、IV期较I、II期以及肿瘤直径≥1cm较<1cm的患者术前血清TSH明显升高(均P<0.001)。结论:术前血清TSH水平是预测甲状腺结节良恶性的重要指标。     

哺乳期过度喂养对幼鼠肥胖和肠道菌群结构的影响

目的 研究哺乳期过度喂养对幼鼠肠道细菌组成的影响以及肠道细菌与哺乳期过度喂养导致的幼年肥胖的相关性.方法 将正常出生体重的4日龄雄性ICR仔鼠分为正常喂养组(NF组,每8只由1只母鼠喂养)和哺乳期过度喂养组(OF组,每4只由1只母鼠喂养),哺乳至3周龄时,对仔鼠进行口服糖耐量试验(OGTT),称量体重、各种器官和脂肪组织的重量,用基于细菌16S rRNA基因的变性梯度凝胶电泳(DGGE)和实时定量PCR分析仔鼠的粪便细菌组成,对细菌类群数量与表型数据进行相关分析.结果 OF组仔鼠从10日龄起体重显著高于NF组,3周龄时附睾和肾周脂肪垫重量显著高于NF组,两组仔鼠的空腹血糖以及OGTT血糖曲线下面积比较差异无统计学意义.对DGGE图谱的主成分分析表明两组仔鼠的菌群结构比较差异有统计学意义.定量PCR显示,OF组仔鼠粪便中产生内毒素的肠杆菌科细菌和产生破坏肠屏障功能的H2S的硫酸盐还原菌的数量显著高于NF组,而双歧杆菌、乳杆菌和丁酸盐产生菌的数量在两组仔鼠之间差异无统计学意义.粪便硫酸盐还原菌的数量与内脏脂肪的重量显著正相关.结论 哺乳期过度喂养增加了肠道中肠杆菌科细菌和硫酸盐还原菌的数量,这些细菌的增加与仔鼠幼年期肥胖相关.     

Recent advances in the study of Kaposi's sarcoma-associated herpesvirus replication and pathogenesis

It has now been over twenty years since a novel herpesviral genome was identified in Kaposi's sarcoma biopsies. Since then, the cumulative research effort by molecular biologists, virologists, clinicians, and epidemiologists alike has led to the extensive characterization of this tumor virus, Kaposi's sarcoma-associated herpesvirus(KSHV; also known as human herpesvirus 8(HHV-8)), and its associated diseases. Here we review the current knowledge of KSHV biology and pathogenesis, with a particular emphasis on new and exciting advances in the field of epigenetics. We also discuss the development and practicality of various cell culture and animal model systems to study KSHV replication and pathogenesis.     

A Unique Protease Cleavage Site Predicted in the Spike Protein of the Novel Pneumonia Coronavirus (2019-nCoV) Potentially Related to Viral Transmissibility

正Dear Editor,In December 2019, a novel human coronavirus caused an epidemic of severe pneumonia(Coronavirus Disease 2019,COVID-19) in Wuhan, Hubei, China(Wu et al. 2020; Zhu et al. 2020). So far, this virus has spread to all areas of China and even to other countries. The epidemic has caused 67,102 confirmed infections with 1526 fatal cases     

Curcuminoids as inhibitors of thioredoxin reductase: A receptor based pharmacophore study with distance mapping of the active site

Curcumin is the yellow pigment of turmeric that interacts irreversibly forming an adduct with thioredoxin reductase (TrxR), an enzyme responsible for redox control of cell and defence against oxidative stress. Docking at both the active sites of TrxR was performed to compare the potency of three naturally occurring curcuminoids, namely curcumin, demethoxy curcumin and bis-demethoxy curcumin. Results show that active sites of TrxR occur at the junction of E and F chains. Volume and area of both cavities is predicted. It has been concluded by distance mapping of the most active conformations that Se atom of catalytic residue SeCYS498, is at a distance of 3.56 from C13 of demethoxy curcumin at the E chain active site, whereas C13 carbon atom forms adduct with Se atom of SeCys 498. We report that at least one methoxy group in curcuminoids is necessary for interation with catalytic residues of thioredoxin. Pharmacophore of both active sites of the TrxR receptor for curcumin and demethoxy curcumin molecules has been drawn and proposed for design and synthesis of most probable potent antiproliferative synthetic drugs.     

The structure, reproduction and taxonomy of Vidalia and Osmundaria (Rhodophyta, Rhodomelaceae)

Comprises species occurring mostly in subtidal habitats in tropical, subtropical and warm-temperate areas of the world. An analysis of the type species, V. spiralis (Sonder) Lamouroux ex J. Agardh, a species from Australia, establishes basic characters for distinguishing species in the genus. These characters are (1) branching patterns of thalli, (2) flat blades that may be spiralled on their axis, (3) width of the blade, (4) primary or secondary derivation of sterile and fertile branchlets and (5) position of sterile and fertile branchlets on the thalli. Application of the latter two characters provides an important basic method for separation of species into three major groups. Osmundaria , a genus known only in southern Australia, was studied in relation to Vidalia , and its separation from the Vidalia assemblage is not accepted. Species of Vidalia therefore are transferred to the older genus name, Osmundaria. Two new species, Osmundaria papenfussii and Osmundaria oliveae are described from Natal. Confusion in the usage of the epithet, Vidalia fimbriala Brown ex Turner has been clarified, and Vidalia gregaria Falkenberg, described as an epiphyte on Osmundaria pro/ifera Lamouroux, is revealed to be young branches of the host, Osmundaria prolifera.     

New or rare chromosome counts in Artemisia L. (Asteraceae, Anthemideae) and related genera from Kazakhstan

Fifteen chromosome counts of six Artemisia taxa and one species of each of the genera Brachanthemum, Hippolytia, Kaschgaria, Lepidolopsis and Turaniphytum are reported from Kazakhstan. Three of them are new reports, two are not consistent with previous counts and the remainder are confirmations of very scarce (one to four) earlier records. All the populations studied have the same basic chromosome number, x = 9, with ploidy levels ranging from 2x to 6x. Some correlations between ploidy level, morphological characters and distribution are noted.