N-甲基亚硝基脲诱导小鼠胸腺淋巴瘤TCR基因重排分析

目的探讨N-甲基亚硝基脲（MNU）诱导的小鼠胸腺淋巴瘤的单克隆起源。方法采用巢式PCR方法,对8例MNU诱导的胸腺淋巴瘤组织进行T细胞受体β链（TCRβ）和γ链（TCRγ）克隆性基因重排分析,并对TCRγ基因重排的PCR产物直接测序。结果 8例胸腺淋巴瘤检测TCRβ和TCRγ均呈克隆性基因重排。DNA序列测定证实TCRγ基因PCR扩增产物为基因重排产物。结论巢式PCR TCR基因重排检测及DNA序列分析证实,MNU诱导的小鼠胸腺淋巴瘤是来源于T细胞的肿瘤。     

TCR基因重排在蕈样肉芽肿诊断中的应用

T细胞在成熟过程中通过T细胞表面受体基因重排,从而具有特异性识别抗原的能力,在这一过程中的任何失调都会导致疾病。蕈样肉芽肿是由于淋巴细胞的恶性增殖所导致的,病变组织表现出T细胞受体基因重排克隆性。通过Southern印迹分析技术和PCR技术来检测T细胞受体基因重排。T细胞受体基因重排的检测在蕈样肉芽肿的诊断的应用上有重要的参考价值。     

猪T细胞受体γ链基因的克隆及生物信息学分析

目的:克隆猪T细胞受体γ链(pTCR-γ)基因,用以研究猪T细胞受体分子结构与功能。方法与结果:以GenBank上登载的pTCR-γ基因为参考序列,用RT-PCR法从猪外周血淋巴细胞中克隆pTCR-γ基因。序列分析表明,pTCR-γ基因开放读框为1026bp,编码341个氨基酸残基,含有由23个氨基酸残基构成的信号肽序列;与参考序列相比,在核苷酸和推导氨基酸序列上的同源性分别为95.6%和88.8%;系统进化分析发现,该基因与绵羊、恒河猴、人、马、牛的同源性相对较高,与褐鼠、家犬、家鼠、家猫的同源性次之,而与禽类、鱼类的同源性最低;生物信息学结构预测表明猪T细胞受体γ链含2个结构域,其中1个为IG_LIKE1结构域(IGv结构域),由第14～114位共101个氨基酸残基组成;另一个为IG_LIKE2结构域(IGc结构域),由第143～238位共96个氨基酸残基组成。结论:克隆并应用生物信息学技术分析了猪T细胞受体γ链基因序列及编码蛋白的结构特征,为进一步研究γ链的结构与功能奠定了基础。     

Notch 1 在外周T 细胞淋巴瘤中的表达及基因突变 及其与临床生存期的相关性研究

目的:检测活化型notch1(NICD)蛋白在外周T细胞淋巴瘤组织中的表达情况,探讨活化型notch1对外周T细胞淋巴瘤患者生存时间的影响,分析其与NOTCH1基因突变之间的关系。方法:免疫组织化学法检测20例外周T细胞淋巴瘤(13例PTCLNOS、7例ALCL)及5例反应性增生患者病变组织活化型notch 1(NICD)抗体的表达,PCR-SSCP及基因测序法分析NOTCH1基因HD-N、HD-C、TAD、PEST片段的突变情况。结果:20例外周T细胞淋巴瘤NICD蛋白均为阳性,5例慢性淋巴结炎均为阴性,其中PTCL NOS组织较ALCL高表达NICD蛋白。淋巴瘤患者HD-N、HD-C、PEST片段存在基因点突变。结论:NOTCH1基因点突变可能为异常表达NICD的原因之一,异常表达的NICD影响外周T细胞淋巴瘤的生存时间。     

C-myc基因重排的套细胞淋巴瘤临床病理分析

目的 分析套细胞淋巴瘤(mantle cell lymphoma,MCL)的临床病理特征,探讨C-myc基因重排对预后影响.方法 收集40例套细胞淋巴瘤患者临床资料,以40例反应性淋巴结炎作为对照,对其进行免疫组织化学及基因检测.结果 40例MCL中C-myc表达水平≥20％有5例,其中3例伴有C-myc基因重排.3例...     

免疫球蛋白重链可变段和T细胞受体可变段的分子进化研究

为阐明免疫球蛋白(Ig)和T细胞受体(TCR)在抗体多样性产生机理上的异同,作者比较了Ig重链可变段(Ig V_H)和TCR可变段(TCR V)的密码子替代率和协同进化,并分析异同的原因。共搜集8种鼠和3种人的TCR α链可变段(V_α),11种鼠和1种人的TCRβ链可变段(V_β),以及2种鼠和4种人的T细胞γ链可变段;同时搜集11种鼠、3种人、3种南美鳄鱼和1种鲨鱼的Ig V_(H_(o))研究结果揭示:(1)对编码蛋白质的密码子来说,TCR V(包括V_α和V_β)的核苷酸替代率为Ig V_H的2.4倍,说明前者有更高的替代率。(2)以协同进化而言,TCR V和Ig V_H的基因重复率分别为1.7×10~(-6)和1.6×10~(-6)/基因年。两者几乎相同,均系低速保持者。TCR V的数目(V_α为100,V_β为30)远少于Ig V_H(数目为300),原因是前者受到主要组织相容性复合体的制约,即受到负选择,这与中性学说观点相一致。文章还讨论了体细胞突变和DNA重排对两类抗体多样性产生上的作用,并探讨了IgV_H和TCR V的假基因问题。     

细胞蜡块诊断淋巴瘤18例

目的探讨18例浆膜腔积液中细胞学诊断淋巴瘤的临床病理学特征、免疫表型、诊断及鉴别诊断、治疗及预后。方法收集武汉大学人民医院2016年1月—2018年12月间由浆膜腔积液诊断为淋巴瘤患者18例,通过常规液基涂片、制作细胞蜡块、HE染色及免疫细胞化学染色,个别病例采用基因重排检测或流式细胞学检查,并部分对照其细胞学诊断和活检组织病理诊断的符合率。结果 18例均行免疫细胞化学检测,结果均为非霍奇金淋巴瘤。其中无淋巴瘤病史的有12例:包括4例弥漫性大B细胞淋巴瘤;1例淋巴浆细胞样淋巴瘤;1例浆细胞瘤;2例T淋巴母细胞淋巴瘤;1例NK/T细胞淋巴瘤;1例外周T细胞淋巴瘤,非特殊类型;2例T细胞淋巴瘤。其余6例均有淋巴瘤病史,其中4例为弥漫性大B细胞淋巴瘤,2例为血管免疫母细胞性T细胞淋巴瘤。结论浆膜腔积液是淋巴瘤的较常见并发症,细胞病理学诊断淋巴瘤难度虽相对较大,但通过制备细胞蜡块,在镜下观察肿瘤细胞成分单一,表现为大量散在分布的不成熟淋巴样细胞,细胞之间无黏附性,同时结合免疫细胞化学染色等相关检测方法,可明确诊断,值得推广。     

儿童急性淋巴细胞白血病特异性标记物的精准检测方法研究

目的：T细胞和免疫球蛋白重链基因重排是微小残留病灶水平的特异性标记物,而微小残留病灶的水平与儿童急性淋巴细胞白血病的复发强烈相关。应用传统的聚合酶链式反应方法来监测IgH／TCR基因重排不仅耗时、耗人力,而且敏感度较低。本研究旨在探索一种更为高效和敏感与实用的监测IgH／TCR基因重排的精准检测方法。方法：应用多重PCR技术检测26个患有急性淋巴细胞白血病的儿童的外周血样品中的标记物,这些儿童是在中国哈尔滨市最近两年内被诊断的患者。分别应用基因扫描和毛细血管电泳方法检测IgH（FRI,FRII,FRⅢ）／TCR（TCRB,TCRγ）基因重排和分析PCR产物的片段。结果：IgH／TCR基因重排和对IgH基因重排的阳性率分别为92．3％和75％,在26个病例中,4个复发病人的IgH的三个片段（FRI,FRII,FRⅢ）基因重排显示阳性。进一步分析显示复发与ign基因重排呈线性相关。结论：实验与临床应用表明,基因扫描这种方法对于IgH／TCR基因重排的检测是可靠的、实用的,因而可用于儿童急性淋巴细胞白血病的诊断和随访。     

树突状表皮T细胞在胸腺内发育的研究进展

树突状表皮T淋巴细胞(DETC),特异性分布在表皮组织内,在皮肤免疫监视,皮肤伤面愈合中发挥重要作用.小鼠DETC发育仅涉及胚胎14.5 ～ 18 d这一短暂时间窗,而后则不再产生这类细胞.本综述拟从DETC T细胞受体(TCR)基因重排特点及调控机制,DETC在胸腺中的阳性选择及调控机制等方面进行论述,以期对DETC...     

γδT细胞及其治疗感染性疾病的研究进展

γδT细胞是一种高度异质性的T淋巴细胞群,根据其表面抗原受体(TCR)γ、δ链的不同可分为多个亚群.γδT细胞有特殊的发育调控模式,不同类型的γδT细胞在迁移到外周组织之前主要在胸腺中产生.除了在肿瘤、自身性免疫疾病中有重要作用之外,γδT细胞亦参与了细菌、真菌、病毒和寄生虫等感染性疾病的防治进程,是抵抗病原体的第一道...     

Role for dopamine in malonate-induced damage in vivo in striatum and in vitro in mesencephalic cultures

Defects in mitochondrial energy metabolism have been implicated in the pathology of several neurodegenerative disorders. In addition, the reactive metabolites generated from the metabolism and oxidation of the neurotransmitter dopamine (DA) are thought to contribute to the damage to neurons of the basal ganglia. We have previously demonstrated that infusions of the metabolic inhibitor malonate into the striata of mice or rats produce degeneration of DA nerve terminals. In the present studies, we demonstrate that an intrastriatal infusion of malonate induces a substantial increase in DA efflux in awake, behaving mice as measured by in vivo microdialysis. Furthermore, pretreatment of mice with tetrabenazine (TBZ) or the TBZ analogue Ro 4-1284 (Ro-4), compounds that reversibly inhibit the vesicular storage of DA, attenuates the malonate-induced DA efflux as well as the damage to DA nerve terminals. Consistent with these findings, the damage to both DA and GABA neurons in mesencephalic cultures by malonate exposure was attenuated by pretreatment with TBZ or Ro-4. Treatment with these compounds did not affect the formation of free radicals or the inhibition of oxidative phosphorylation resulting from malonate exposure alone. Our data suggest that DA plays an important role in the neurotoxicity produced by malonate. These findings provide direct evidence that inhibition of succinate dehydrogenase causes an increase in extracellular DA levels and indicate that bioenergetic defects may contribute to the pathogenesis of chronic neurodegenerative diseases through a mechanism involving DA.     

Scurvy in capybaras bred in captivity in Argentine

In order to determine if the absence of vitamin C in the diet of capybaras (Hydrochoerus hydrochaeris) causes scurvy, a group of seven young individuals were fed food pellets without ascorbic acid, while another group of eight individuals received the same food with 1 g of ascorbic acid per animal per day. Animals in the first group developed signs of scurvy-like gingivitis, breaking of the incisors and death of one animal. Clinical signs appeared between 25 and 104 days from the beginning of the trial in all individuals. Growth rates of individuals deprived of vitamin C was considerably less than those observed in the control group. Deficiency of ascorbic acid had a severe effect on reproduction of another population of captive capybaras. We found that the decrease in ascorbic acid content in the diet affected pregnancy, especially during the first stages. The results obtained suggest that it is necessary to supply a suitable quantity of vitamin C in the diet of this species in captivity.     

Changes in lactate dehydrogenase activity in chicken tissues in hyperthyreosis in ontogenesis

The lactate dehydrogenase activity in reactions of lactate oxidation and synthesis was studied in subfractions of the chicken brain, heart and liver at the embryonal, early postembryonal and adult stages of development after thyroxine administration. It has been shown that during embryogenesis thyroxine predominantly enhanced the rate of lactate oxidation in the mitochondrial tissues. A marked increase in the lactate synthesis was found in cytoplasm of the adult chicken tissues. Specificity of enzyme activity alterations was detected in the chicken brain during ontogenesis after thyroxine administration.     

SSTR5 ablation in islet results in alterations in glucose homeostasis in mice

Somatostatin (SST) peptide is a potent inhibitor of insulin secretion and its effect is mediated via somatostatin receptor 5 (SSTR5) in the endocrine pancreas. To investigate the consequences of gene ablation of SSTR5 in the mouse pancreas, we have generated a mouse model in which the SSTR5 gene was specifically knocked down in the pancreatic beta cells (betaSSTR5Kd) using the Cre-lox system. Immunohistochemistry analysis showed that SSTR5 gene expression was absent in beta cells at three months of age. At the time of gene ablation, betaSSTR5Kd mice demonstrated glucose intolerance with lack of insulin response and significantly reduced serum insulin levels. Insulin tolerance test demonstrated a significant increase of insulin clearance in vivo at the same age. In vitro studies demonstrated an absence of response to SST-28 stimulation in the betaSSTR5Kd mouse islet, which was associated with a significantly reduced SST expression level in betaSSTR5Kd mice pancreata. In addition, betaSSTR5Kd mice had significantly reduced serum glucose levels and increased serum insulin levels at 12 months of age. Glucose tolerance test at an older age also indicated a persistently higher insulin level in betaSSTR5Kd mice. Further studies of betaSSTR5Kd mice had revealed elevated serum C-peptide levels at both 3 and 12 months of age, suggesting that these mice are capable of producing and releasing insulin to the periphery. These results support the hypothesis that SSTR5 plays a pivotal role in the regulation of insulin secretion in the mouse pancreas.