卡培他滨片联合奥沙利铂注射剂治疗晚期结肠癌患者的临床研究

目的观察卡培他滨片联合奥沙利铂注射剂治疗晚期结肠癌患者的临床疗效及安全性。方法将97例晚期结肠癌患者随机分为对照组49例和试验组48例。对照组给予130 mg·m^-2奥沙利铂,静脉滴注,于2~3 h内滴完,第1天;试验组在对照组治疗的基础上,给予1 250 mg·m^-2卡培他滨,bid,口服,第1~14天。2组患者均治疗6个疗程,每个疗程21 d。比较2组患者的临床疗效,血清癌基因ras产物P21蛋白(rasP21)和环氧化酶-2(COX-2)的水平,以及药物不良反应的发生情况。方法治疗后,试验组和对照组的总有效率分别为60.42%(29例/48例)和36.73%(18例/49例),差异有统计学意义(P<0.05)。治疗后,试验组和对照组的rasP21分别为(10.03±2.11)和(19.90±3.02)ng·mL^-1,COX-2分别为(3.11±1.10)和(6.70±2.01)ng·mL^-1,差异均有统计学意义(均P<0.05)。2组患者的药物不良反应均以恶心呕吐、白细胞减少、血小板减少、手足综合征、神经毒性和皮炎为主。试验组和对照组的总药物不良反应发生率分别为66.67%(32例/48例)和73.47%(36例/49例),差异无统计学意义(P>0.05)。结论卡培他滨片联合奥沙利铂注射剂治疗晚期结肠癌患者的临床疗效确切,其能明显降低血清rasP21和COX-2水平,且不增加药物不良反应的发生率。     

氟化钠对L02人正常肝细胞衰老及相关蛋白表达影响的实验研究

目的 研究氟化钠（NaF）是否会诱导人肝细胞 L02衰老及衰老相关标志蛋白水平的改变。方法 不同浓度 (0、1、2、3、4、5、6、7和8mmol/L) NaF 处理 L02人正常肝细胞,CCK-8 法检测细胞存活率的变化以筛选 NaF 的作用浓度;衰老标志物 β-半乳糖苷酶 (β-galactosidase, β-Gal) 染色检测衰老阳性细胞;实时荧光定量 PCR (Real-time PCR) 和蛋白免疫印迹 (Western Blot) 测定细胞衰老标志蛋白 p16,p21 mRNA 和蛋白的表达水平;流式细胞术分析细胞周期的变化情况。结果 CCK-8 结果显示,NaF 浓度为 1、4、7mmol/L时 L02细胞的存活率（87.38±0.93、66.72±2.81、52.17±2.04）均低于对照组［(100.00±0.00),均 P<0.01］,且每组之间的细胞存活率差异存在统计学意义（均 P<0.01）,因此 NaF 选用1、4、7 mmol/L 处理L02细胞作为低氟组、中氟组、高氟组开展研究;β-半乳糖苷酶染色结果显示,低、中、高氟组中细胞衰老率 (23.15±0.23、36.06±0.40、65.36±0.82)均高于正常组［(3.27±0. 27),P<0.01］;Real-time PCR 结果显示,p16、p21 mRNA在低、中、高氟组中表达(2.29±0.19、3.44±0.30、5.25±0.32;1.88±0.22、3.22±0.24、7.33±0.30)表达均高于正常对照组［(1.00±0.00;1.00±0.00),均P<0.01］。低、中、高氟组中p16蛋白水平(93.68±3.40、116.25±7.30、122.31±3.00)均高于对照组［(78.07±4.17),P<0.05,P<0.01,P<0.01),低、中、高氟组中p21蛋白水平(87.61±5.22、121.62±4.27、147.95±7.81)均高于对照组［(61.32±4.56),均P<0.01)］;流式结果显示,低、中、高氟组 L02 细胞周期均停滞在 G2 期,与对照组相比,差异具有统计学意义 (P<0.01)。结论 NaF 处理的人肝细胞 L02 中细胞衰老率及衰老标志蛋白 p16、p21 的 mRNA 和蛋白表达升高,这可能提示了 NaF 可导致 L02 细胞衰老,进一步说明细胞衰老在氟化物诱导的肝损伤中可能具有重要作用。     

骨肉瘤N—ras,c—myc基因异常及其蛋白产物的表达

目的：探讨癌基因Ｎ－ｒａｓ，ｃ－ｍｙｃ及其蛋白表达与骨肉瘤的关系，方法：Ｓｏｕｔｈｅｒｎｂｌｏｔ和免疫组织化学（ＬＳＡＢ法）同步检查９例人骨肉瘤Ｎ－ｒａｓ，ｃ－ｍｙｃ癌基因和其ｐ２１ｒａｓｃ－ｍｙｃ蛋白产物表达，结果：Ｎ－ｒａｓ基因１例有为失改变，检出率１１％（１／９），ｃ－ｍｙｃ基因有３例为扩增改变，检出率３３％（３／９），ｐ２１ｒａｓ，ｃ－ｍｙｃ基因蛋白表达阳性率分别为７８％（７例），８９％（     

MicroRNA, the putative molecular control for mid-life decline

In a society experiencing an accelerating increase in the middle- and old-age population, there is an urgent need to address age-dependent frailties by a paradigm shift, i.e. a new medical strategy to combat middle-age decline at the stage before incipient old-age problems develop into full-blown diseases. We suggest that a decline in cellular health status occurs at mid-life, and that this decline may involve a universal or system-specific programmatic shift of signaling control. This decline, although sub-clinical and asymptomatic, may precipitate increased risk of late-life diseases. The putative control for this mid-life cellular decline may be governed by a recently discovered group of molecular species, the microRNAs, small RNAs of approximately 22 nucleotide bases. In general microRNAs, while themselves not coding for any protein product, negatively regulate the expression of target genes by either degrading their message or inhibiting translation by binding to their 3'-untranslated region (UTR). Thus, possible derailment of these negative regulators for gene expression in mid-life may be the putative force inducing molecular frailty in individual cell signaling, and in time leading to tissue-wide dysfunction. A challenge for future research is then to identify these dysfunctional microRNAs, in order to develop advance diagnosis and therapy to combat mid-life decline, a preventive medicine approach to block, delay or reduce the risk of old-age diseases.     

Molecular characterization of rare bovine group A rotavirus G15P[11] and G15P[21] strains from eastern India: identification of simian SA11-like VP6 genes in G15P[21] strains

During a surveillance study (November 2001-March 2005), one rare G15P[11] and two rare G15P[21] bovine group A rotavirus strains were detected in diarrhoeic calves in Eastern India. Sequence analysis of the VP8*, VP6, NSP4 and NSP5 genes of the G15P[11] strain confirmed its bovine origin. Although the NSP4 and NSP5 genes of the two G15P[21] strains were of bovine origin, their VP6 genes shared higher nucleotide and amino acid identities with simian strain SA11 (92.5-93.1% and 98.5-98.7%) than bovine strains (88.5-88.9% and 97-97.2%), and by phylogenetic analysis, exhibited clustering with SA11, distantly related to bovine strains. All these pointed towards a possible reassortment event of VP6 gene between bovine and simian (SA11-like) strains. Therefore, the present study provided molecular evidence for bovine origin of G15 strains and revealed a rare instance of genetic diversity in the bovine VP6 gene, otherwise conserved in group A rotavirus strains from cattle.     

转化生长因子-β1的Smad4非依赖性途径对胰腺癌细胞生长的影响

目的探讨转化生长因子(TGF)-β1过表达对Smad4纯合性缺失的胰腺癌细胞生长的影响。方法将含TGF-β1的真核表达载体转染到人胰腺癌细胞BxPC3中,通过流式细胞仪、生长曲线以及细胞迁移试验观察其对BxPC3生物学行为的影响。用Western印迹法检测TGF-β1对BxPC3细胞中p21WAF/CLIP1表达的影响。结果转染TGF-β1基因的BxPC3细胞的形态发生明显改变,其生长速度自第4天开始较转染空载体pcDNA3的阴性对照组减慢。发现BxPC3细胞组S期细胞(27.53±0.02)%与pcDNA3组(26.32±0.01)%的比例均高于TGF-β1组(17.01±0.03)%,P<0.01,表明TGF-β1阻止细胞进入S期。细胞迁移试验表明转染的细胞运动能力明显增加。Western印迹法检测表明p21WAF/CLIP1的表达也相应增高。结论TGF-β1的Smad4非依赖性途径通过增强p21WAF/CLIP1的表达使细胞阻滞于G-G期,从而抑制细胞生长,并且该通路能诱导上皮细胞向间叶细胞转变。     

Effect of 21-aminosteroid on extracellular energy-related metabolites and amino acids after compression injury of rat spinal cord

We evaluated in a rat model of severe spinal cord compression the effect of the 21-aminosteroid tirilazad on extracellular levels of energy metabolites and amino acids, until 3 h after injury. The compound was given i.v. 30 min before injury (3 mg/kg) and hourly thereafter (1.5 mg/kg). The findings were compared with previously reported effects of methylprednisolone. Both treated and untreated rats with spinal cord compression showed, at 10 min after injury, a five-to sixfold elevation of extracellular lactate above the preinjury level. There was no significant difference for lactate, pyruvate or lactate/pyruvate ratio between the treated and untreated injured groups at any time point after trauma. Glutamate was significantly elevated both in treated and untreated injured rats for 20 min after trauma. The mean glutamate level was lower in animals treated with 21-aminosteroid. However, there was no statistically significant difference between the treated and untreated rats at any time after trauma. There was no statistically significant difference between the groups for aspartate, serine, glutamine, histidine, glycine, threonine, taurine, alanine and tyrosine. In conclusion our findings indicate that, in the injured spinal cord, methylprednisolone and the 21-aminosteroid have differences and similarities, regarding their effects on energy and amino acid metabolism. The lowering of the lactate and arginine levels early after trauma seen with methylprednisolone pretreatment was absent after 21-aminosteroid pretreatment. However, the mean extracellular level of glutamate was lower with both methyl-prednisolone and 21-aminosteroid after injury, although the difference was not statistically significant between treated and untreated rats.     

Screening for mutations by expressing patient cDNA segments in E. coli: homocystinuria due to cystathionine beta-synthase deficiency.

Deficiency of cystathionine beta-synthase (CBS) causes the most common form of inherited homocystinuria. We developed a simple CBS expression system in E. coli to screen for pathogenic mutations in affected individuals. Portions of patient cDNAs were amplified by PCR and used to replace the corresponding segments of normal human CBS cDNA in the bacterial expression plasmid pHCS3. Hybrid CBS was expressed in E. coli and the segments of patient's cDNA which extinguished CBS activity were sequenced to identify the mutation. The first study of a pyridoxine-responsive patient using this screen revealed that of the clones which contained either the middle or the 3'-portion of his cDNA, about half were devoid of catalytic activity. Subsequent sequencing of the affected segments confirmed a compound heterozygosity for a maternal T833-->C transition (I278T) and for a paternal A-->C transversion in the intron 11 splice acceptor. The latter mutation leads to an in-frame deletion of exon 12 (nt 1224-1358, amino acids W408 to G453). This bacterial expression system proved to be a rapid screening method for localizing pathogenic mutations in CBS, allowing us to sequence the affected portions of mutant cDNA within 7-10 days of harvesting cultured fibroblasts.     

Mutation in ribosomal protein L21 underlies hereditary hypotrichosis simplex

Hereditary hypotrichosis simplex (HHS) is a form of nonsyndromic inherited hair loss disorders without characteristic hair shaft changes, which has marked genetic and clinical heterogeneity. After mapping the locus to 13q12.12-12.3 in a Chinese family with a generalized variant of autosomal dominant HHS (ADHHS), exome sequencing was performed in an affected individual. The cause of the disease in this family was identified as a c.95G>A (p.Arg32Gln) mutation in the RPL21 gene, which encoding the ribosomal protein L21. This mutation cosegregated completely with the disease phenotype and was not observed in unaffected family members, 200 normal controls, the dbSNP database, the YH database or pilot data from the 1000 Genomes Project. Additionally, this mutation was found in two patients from another unrelated Chinese family with HHS. To the best of our knowledge, this is the first report describing the involvement of a ribosomal protein gene mutation in a non-syndromic hair loss disorder.