Twist在大肠癌中的表达及其与临床病理指标的关系

目的探讨肿瘤相关基因Twist表达在大肠癌临床病理诊断中的应用价值。方法应用鼠抗人Twist单克隆抗体采用S-P免疫组织化学方法检测112例不同类型大肠癌组织及40例正常肠粘膜组织中Twist的表达并与临床病理指标比较。结果在112例大肠癌组织中,Twist基因阳性表达78例;在正常组织中其阳性表达为15例,两者比较具有显著统计学差异(χ2=11.21,p=0.001);进一步综合临床病理资料统计分析,Twist在大肠癌组织中表达与肿瘤的分化程度、肿瘤浸润、淋巴结转移、Duke’s分期有关(p值分别为0.008、0.017、0.044、0.011),均有显著差异;而与病人年龄、性别无关(p值为0.286、0.887)。结论Twist基因表达检测能较好的判断大肠癌肿瘤分化程度、浸润、淋巴结转移等,在大肠癌诊断中作用明确,对临床病理学诊断有明确的指导作用。     

经圆窗径路导入正庚醇建立老年性聋模型的实验研究

目的 研究经耳后圆窗径路向C57BL/6Cnc小鼠内耳导入正庚醇对其听性脑干诱发电位(ABR)的影响,并建立老年性耳聋模型.方法 选取30只健康4周龄C57BL/6Cnc小鼠,随机分成实验组和对照组,每组15只.实验组经耳后圆窗径路缓慢导入正庚醇5μL,对照组经耳后圆窗径路缓慢导入0.9％氯化钠注射液5μL.各组小鼠分...     

局部晚期不可手术食管癌同步放化疗联合尼妥珠单抗的初步临床分析

目的:探讨局部晚期食管癌同步放化疗联合尼妥珠单抗治疗的不良反应及疗效。方法:回顾性分析北京大学肿瘤医院2015—2020年间使用同步放化疗联合尼妥珠单抗治疗的30例患者资料,采用 Kaplan- Meier法生存分析。 结果:中位随访时间22.5个月,总客观有效率为93%。1、2、3年...     

不稳定血红蛋白病Hb Alesha一例报告并文献复习

不稳定血红蛋白病(unstable hemoglobinopathy,UHb)是一类由于珠蛋白结构异常引起血红蛋白不稳定的疾病。90%以上的结构异常是由于编码珠蛋白基因单个核苷酸替代导致的错义突变,引起相应氨基酸的改变,使血红蛋白不稳定,红细胞易于被破坏。目前全球报道了150余种UHb[1],大部分属常染色体显性遗传,但也有不少患者无家族史。本文报道不稳定血红蛋白病Hb Alesha 1例并总结复习相关文献,以提高对该病的认识。     

乙肝口服液中三七、赤芍、延胡索、当归的薄层鉴别研究

目的::对乙肝口服液进行薄层色谱鉴别研究。方法:采用薄层色谱法对乙肝口服液中的三七、赤芍、延胡索、当归进行鉴别研究。结果:三七、赤芍、延胡索、当归薄层色谱图斑点清晰,重现性好,无干扰。结论:该方法快速,简便,专属性强,可用于乙肝口服液的质量控制。     

Effects of Internet-Based Nutrition and Exercise Interventions on the Prevention and Treatment of Sarcopenia in the Elderly

Effective nutrition and exercise interventions may improve sarcopenia in the elderly. The purpose of our study was to investigate the effectiveness of Internet-based nutrition and exercise interventions in the elderly with sarcopenia. Participants were divided into 4 groups: control, nutrition, exercise, and comprehensive (nutrition plus exercise) groups; there was at least 50 participants in each group. Our trial lasted 12 weeks. We conducted dietary and exercise interventions through an app and collected feedback from the participants every three weeks. Information on the diet, skeletal muscle mass, and muscle function was collected before and after the interventions. The comprehensive group had higher high-quality protein intake than the control (p = 0.017) and exercise (p = 0.012) groups. After the interventions, we obtained differences in skeletal muscle mass, skeletal muscle mass/height², skeletal muscle mass/weight, muscle mass/BMI, and skeletal muscle mass/body fat percentage (p < 0.05). Changes in average daily energy and total daily protein intakes were not significantly different; however, there was an overall improvement in the intervention groups relative to baseline data. There were no changes in the average daily time of moderate physical activity. The Internet was an effective tool of nutrition intervention in the elderly with sarcopenia. The Internet-based nutrition intervention improved high-quality protein intake and skeletal muscle mass in the elderly with sarcopenia.     

Effects of Electromagnetic Fields on the Microstructure of Laser Cladding

The fast heating and quenching of laser cladding increase the internal stresses in the cladding layer. Moreover, the quick condensation of the molten pool leads to an uneven distribution of the internal elements and coarse grains of the structure. To address the above defects and increase the molding quality of laser cladding, an electromagnetic field was introduced into the laser cladding technique, and the effects of the external assisted electromagnetic field on the mixed metal fluid in the molten pool were explored. On this basis, the action of the electromagnetic field on the flow states of the molten pool was further analyzed. The results demonstrate that after introducing electromagnetic assistance, the material flow in the molten pool accelerated as a response to the periodic changes in electromagnetic forces and the influences of the electromagnetic field on crystallization, thus refining the grains and improving the grain distribution uniformity in the cladding layer. The dendritic crystals in the cladding layer decreased, while the isometric crystals and the cellular-like dendrites increased. The element distribution in the cladding layer increased in uniformity. Additionally, this method can decrease the dilution rate of the cladding layer and improve its overall hardness. A laser-cladding test of the Ni-based powder was carried out on the AISI 1045 steel surface under the coaxial powder-feeding mode. Moreover, the influences of the electromagnetic field on the microstructure of the laser-cladding layer were compared, and the causes of the changes were disclosed.     

Pore-Forming Cardiotoxin VVA2 (Volvatoxin A2) Variant I82E/L86K Is an Atypical Duplex-Specific Nuclease

VVA2 (volvatoxin A chain 2) is a cardiotoxic protein purified from Volvariella volvacea. Its biological activities include hemolysis, writhing reaction, neurotoxicity, and ventricular systolic arresting activity. The cytotoxicity of VVA2 was mainly considered due to its pore-forming activity. Here we report a novel biological activity of its variants VVA2 I82E/K86K as a duplex-specific nuclease. Recombinant VVA2 variant I82E/L86K (Re-VVA2 I82E/L86K), deprived of the oligomerization property, shows increased nuclease activity compared to VVA2. Re-VVA2 I82E/L86K converts supercoiled DNA (Replicative form I, RF I) into nicked form (RF II) and linear form (RF III) in the presence of Mg²⁺ or Mn²⁺. Besides plasmid DNA, it also exhibits nuclease activity on E. coli genomic DNA rather than ssDNA or RNA. Re-VVA2 I82E/L86K preferentially cleaves dG-dC-rich dsDNA regions and shows the best performance at pH 6–9 and 55 °C. Our structure–function study has revealed amino acid E111 may take an active part in nuclease activity through interacting with metal ions. Based on the sequences of its cleavage sites, a “double-hit” mechanism was thereby proposed. Given that Re-VVA2 I82E/L86K did not exhibit the conserved nuclease structure and sequence, it is considered an atypical duplex-specific nuclease.     

Decades of Genetic Research on Soybean mosaic virus Resistance in Soybean

This review summarizes the history and current state of the known genetic basis for soybean resistance to Soybean mosaic virus (SMV), and examines how the integration of molecular markers has been utilized in breeding for crop improvement. SVM causes yield loss and seed quality reduction in soybean based on the SMV strain and the host genotype. Understanding the molecular underpinnings of SMV–soybean interactions and the genes conferring resistance to SMV has been a focus of intense research interest for decades. Soybean reactions are classified into three main responses: resistant, necrotic, or susceptible. Significant progress has been achieved that has greatly increased the understanding of soybean germplasm diversity, differential reactions to SMV strains, genotype–strain interactions, genes/alleles conferring specific reactions, and interactions among resistance genes and alleles. Many studies that aimed to uncover the physical position of resistance genes have been published in recent decades, collectively proposing different candidate genes. The studies on SMV resistance loci revealed that the resistance genes are mainly distributed on three chromosomes. Resistance has been pyramided in various combinations for durable resistance to SMV strains. The causative genes are still elusive despite early successes in identifying resistance alleles in soybean; however, a gene at the Rsv4 locus has been well validated.     

常见革兰阳性细菌鉴定与耐药检测基因芯片的临床应用

目的利用基因芯片技术进行常见革兰阳性细菌的细菌鉴定和耐药性检测。方法用生理生化鉴定和药敏纸片法确定445份革兰阳性细菌菌株的细菌种类和耐药性,盲法进行革兰阳性细菌鉴定与耐药检测基因芯片的检测,用SPSS 10.0 for Windows软件统计分析。结果与临床常规方法相比,耐药检测基因芯片鉴定指标的灵敏度均>96%,特异度均>98%;耐药检测指标的灵敏度均>94%,特异度均>90%。χ2检验结果P值均>0.05,基因芯片检测结果与临床常用方法检测结果差异无统计学意义。Kappa值均>0.75,2种方法一致性较好。结论基因芯片技术对细菌鉴定和耐药检测有一定的临床应用价值。