超声引导下细针穿刺检测甲状腺乳头状癌 ret/PTC基因重组突变

目的了解ret／PTC基因突变与超声、病理诊断在甲状腺乳头状癌诊断中的关系。方法术前超声检查，并在超声引导下细针穿刺，活体取材进行病理诊断和逆转录聚合酶链（RT-PCR）方法检测ret／PTC基因突变。结果在34例超声与病理诊断的甲状腺乳头状癌（PTC）患者中，16例分子生物学检测发现ret／PTC基因突变（47％），其中8例为PTC-1基因突变（50％），2例PTC-2基因突变（12．5％），2例PCT-3基因突变（12．5％），3例PTC-1和PTC-2突变同时存在（18．75％），1例PTC-1和PTC-3突变同时存在（6．25％）。结论ret／PTC基因重组突变可存在于散发的甲状腺乳头状癌中，主要表现PTC-1型。应用超声引导下细针穿刺与甲状腺乳头状癌基因突变的检测相结合是早期诊断甲状腺乳头状癌的有效方法。     

A dynamic regulation of GDNF-family receptors correlates with a specific trophic dependency of cranial motor neuron subpopulations during development

Glial cell line-derived neurotrophic factor (GDNF) family ligands promote the survival of developing motor neurons in vivo and in vitro. However, not all neurons survive with any single ligand in culture and GDNF null mutant mice display only a partial motor neuron loss. An interesting possibility is that subpopulations of motor neurons based on their function and/or their myotopic organization require distinct members of GDNF family ligands. Because responsiveness to the different ligands depends on the expression of their cognate ligand-binding receptor we have herein addressed this issue by examining the expression of GDNF-family receptors (gfr) during development and in the adult in cranial motor nuclei subpopulations. We have furthermore examined the in vivo role of GDNF for cranial motor neuron subpopulations. The shared ret receptor was expressed in all somatic, branchial and visceral cranial embryonic motor nuclei examined, showing that they are all competent to respond to GDNF family ligands during development. At early stages of development both the GDNF receptor, gfralpha1, and the neurturin (NTN) receptor, gfralpha2, were expressed in the oculomotor, facial and spinal accessory, and only gfralpha1 in the trochlear, superior salivatory, trigeminal, hypoglossal and weakly in the dorsal motor nucleus of the vagus and the ambiguous nucleus. The abducens nucleus was negative for both gfralpha1 and gfralpha2. The artemin (ART) receptor, gfralpha3, was expressed only in the superior salivatory nucleus. A motor neuron subnuclei-specific expression of gfralpha1 and gfralpha2 was seen in the facial and trigeminal nuclei which corresponded to their dependence on GDNF in null mutant mice. We found that the expression was dynamic in these nuclei, which may reflect developmental changes in their trophic factor dependency. Analysis of GDNF null mutant mice revealed that the dynamic receptor expression is regulated by the ligand in vivo, indicating that the attainment of changes in dependency could be ligand induced. Our results indicate that specific GDNF family ligands support selective muscle-motor neuron circuits during development.     

双黄连对呼吸道合胞病毒感染的气道上皮细胞炎症因子释放的影响

目的：探讨双黄连及其含药血清对呼吸道合胞病毒(RSV)感染的气道上皮细胞(A549)的炎症因子释放的影响及其药物作用机理。方法：以ELISA法测定炎症介质的含量，观察复方双黄连及其含药血清以不同的给药方式(Ⅰ组：感染前给药、Ⅱ组：感染时给药、Ⅲ组：感染后给药)对RSV刺激A549细胞引发的炎症介质IL-8、IL-6、TNF-α释放的作用。结果：RSV刺激气道上皮细胞A549后IL-8的分泌水平增加，而对IL-6、TNF-α影响不大；双黄连复方及其含药血清均能显降低RSV诱导A549释放的IL-8水平，并以感染前给药的途径下调IL-8的作用最为明显。结论：RSV能诱导气道上皮细胞释放炎症因子IL-8，双黄连可通过抑制RSV引起的IL-8释放，并在病毒感染的气道炎症控制中起着一定的作用。     

多发性内分泌腺瘤2A型家系中ret原癌基因突变的分子筛查

目的探寻2个多发性内分泌腺瘤2A型(MEN2A)家系发病的分子机制。方法提取1982年和1992年中山大学附属第一医院收集的2个MEN2A家系共9名成员外周血基因组DNA,对ret原癌基因21个外显子进行聚合酶链反应(PCR),PCR产物进行直接测序。结果家系1中2例患者存在ret原癌基因exon11的C634R突变,exon2的A45A和exon13的L769L2处多态性;家系2中1例患者存在ret原癌基因C634Y突变,exon2的A45A存在多态性,另外筛查出其子为该基因突变携带者。结论本研究2个家系存在exon11的C634位点突变,达到MEN2A基因水平上的诊断,对其临床治疗及其后代的早期诊断有重要指导意义。     

The GDNF/Neurturin-Ret multicomponent receptor system

Glial cell line-derived neurotrophic factor (GDNF) and neurturin (NTN) are structurally related neurotrophic factors that play crucial roles in the survival of peripheral sensory, sympathetic and dopaminergic neurons as well as motoneurons. Glial cell line-derived neurotrophic factordeficient mice showed lack of enteric neurons and renal agenesis or dysgenesis. Surprisingly, this phenotype was strikingly similar to that of ret proto-oncogene-deficient mice, suggesting that Ret tyrosine kinase might be a functional receptor for GDNF. Recent studies demonstrated that both GDNF and NTN were able to induce Ret tyrosine phosphorylation although they did not bind to Ret with high affinity, but novel glycosyl-phosphatidylinositol (GPI)-linked cell-surface proteins as ligand-binding components were required for Ret activation. Since GDNF and NTN are expected as therapeutic agents in neurodegenerative disorders such as Parkinson's disease and amyotrophic lateral sclerosis, the studies on the mechanisms of their biological actions through Ret would contribute to the development of new therapeutic strategies for these diseases.     

慢性酒精刺激对大鼠海马胶质源性神经营养因子及其功能性受体c-ret mRNA表达的影响

采用原位分子杂交方法观察了慢性酒精刺激对大鼠海马胶质源性神经营养因子 (GDNF)及其功能性受体 c-ret m RNA表达的影响。结果发现 :慢性酒精刺激 3 0 d时 ,GDNF与 c-retm RNA在海马的表达与对照组相比明显增加 ;慢性酒精刺激 60 d时 GDNF与 c-ret m RNA的表达与 3 0 d时相比显著下降。此结果提示 ,GDNF及其功能性受体 c-ret可能在慢性酒精刺激的早期对海马神经元具有保护作用     

甲状腺癌相关基因研究进展

甲状腺癌相关基因的检测对甲状腺癌早期诊治及预后判断有重要意义。近年来研究发现,ras基因的点突变在甲状腺肿瘤中发生率可高达40%;ret基因重排与甲状腺乳头状癌密切相关;抑癌基因p53的失活与甲状腺癌有关;erbB-2基因突变亦可在甲状腺癌中检测到,但其在甲状腺癌中的作用还不十分明了。甲状腺癌中检测到BRAF基因第15外显子-1 796位点T/A转换,且突变率可高达40%左右,国内尚无相关报道。     

甲状腺癌中ret/ptc癌基因表达的研究

目的探讨ret原癌基因活化形式ret/ptc癌基因在甲状腺癌发病机制中的作用和判断其生物学行为。方法应用RTnPCR方法检测了37例甲状腺癌ret/ptc癌基因的表达,包括乳头状癌为26例,滤泡癌8例,髓样癌2例,未分化癌1例。结果26例甲状腺乳状癌中有11例表达为阳性,阳性率为42.3%,8例滤泡癌、2例髓样癌和1例未分化癌均表达为阴性。组织学观察显示,ret/ptc阳性组病例多伴有淋巴细胞浸润(63.6%),显著高于阴性组病例(20.0%,P<0.05),临床病理资料显示,患者发病年龄平均为28.9岁,显著低于阴性组病例的45.9岁(P<0.05),而与患者性别,肿瘤大小,淋巴结转移无显著相关性,随访结果表明在复发病例中无ret/ptc阳性表达病例。结论我们认为ret原癌基因的活化与甲状腺乳头状癌的发生有关,具有ret/ptc癌基因阳性表达的患者一般发病年龄较小,肿瘤恶性程度不高,患者预后相对较好,可作为临床上诊断及判断其生物学行为的参考指标。     

Cancer-retina antigens as potential paraneoplastic antigens in melanoma-associated retinopathy

Melanoma-associated retinopathy is a rare paraneoplastic neurological syndrome characterized by retinopathy in melanoma patients. The main photoreceptor proteins have been found to be expressed as cancer-retina antigens in melanoma. Here we present evidence that these can function as paraneoplastic antigens in melanoma-associated retinopathy. Sera and one tumor cell line of such patients were studied and ret-transgenic mice spontaneously developing melanoma were used as a murine model for melanoma-associated retinopathy. Splenocytes and sera were used for adoptive transfer from tumor-bearing or control mice to wild-type mice. Retinopathy was investigated in mice by funduscopy, electroretinography and eye histology. Expression of photoreceptor proteins and autoantibodies against arrestin and transducin were detected in melanoma-associated retinopathy patients. In tumor-bearing ret-transgenic mice, retinopathy was frequently (13/15) detected by electroretinogram and eye histology. These pathological changes were manifested in degenerations of photoreceptors, bipolar cells and pigment epithelium as well as retinal detachment. Mostly these defects were combined. Cancer-retina antigens were expressed in tumors of these mice, and autoantibodies against arrestin were revealed in some of their sera. Adoptive transfer of splenocytes and sera from tumor-bearing into wild-type mice led to the induction of retinopathy in 4/16 animals. We suggest that melanoma-associated retinopathy can be mediated by humoral and/or cellular immune responses against a number of cancer-retina antigens which may function as paraneoplastic antigens in melanoma-associated retinopathy.