羊水原位培养法联合染色体微阵列分析在产前诊断中的应用

摘要:目的评估 羊水原位培养法联合染色体微阵列分析(CMA)技术在产前诊断检出胎儿染色体异常中的应用价值。方法回顾性分析2018年10月至2023年2月于怀化市妇幼保健院因不同产前诊断指征而行羊水穿刺术的3133例孕妇,比较羊.水原位培养法和CMA法在胎儿染色体异常方面的检出率和差异。结果在3133例样本中,双指征组的异常检出率均较单指征组分别增加0.95%(羊水原位培养法)和2.36% ( CMA);两种技术联合检测共检出796例异常(检出率25.41%),其中羊水原位培养法检出300例(9.58%) ,CMA法检出706例(22.53%)。两者均能检出145 例非整倍体异常和31例染色体结构异常,但CMA另增加检出169例提示致病或可能致病的染色体拷贝数变异(CNV)、杂合性缺失(L0H)、杂合性不存在( A0H)/纯合区域(ROH)及单亲体二倍体异常(UPD),而羊水原位培养法增加检出11 例染色体结构异常。两者联合检出嵌合体23例(0.73%)。结论羊水原位培养法与 CMA技术互为补充,联合应用可显著提高胎儿染色体异常的检出率,可为产前遗传咨.询提供更详细准确的信息,有助于孕妇决策是否终止妊娠。     

基因芯片技术检测恙虫病东方体DNA的方法建立

目的　研制用于东方体检测的基因芯片 ,建立快速、灵敏、特异的恙虫病诊断方法。方法　根据东方体 5 6kD外膜蛋白基因序列 ,设计群特异性引物及探针 ,制备寡核苷酸芯片。用Cy3标记的引物 ,利用不对称PCR技术扩增DNA片段 ,将扩增的DNA片段与芯片上的探针杂交 ,用荧光扫描仪检测并分析信号。结果　建立的基因芯片能够检测恙虫病东方体标准株DNA的特异性荧光信号。具有特异、灵敏、快速的优点。结论　成功制备的基因芯片有望应用于恙虫病东方体多种样本的检测 ,为恙虫病提供最为理想的诊断方法。     

1例染色体复杂结构异常患儿的遗传学病因分析

目的明确1例因肌张力低下,生长发育迟缓,反应迟钝就诊患儿的遗传学病因。方法用常规外周血淋巴细胞培养G显带对患儿及其父母进行核型分析,并采用SNP(single nucleotide polymorphisms)基因芯片进行染色体全基因组分析。结果G显带染色体分析初步判定患儿核型为46,XY,t(2; 12; 18; 14)(q31; p13; q21.3; q11.2),为4条染色体复杂易位; SNP芯片检测分析提示患儿染色体18q21.31-q22.3区域存在1.502 2×10~7bp的片段缺失。患儿父母染色体核型及芯片检测未见明显异常,患儿为新发复杂染色体结构异常。结论染色体18q21.31-q22.3微缺失及4条染色体的复杂易位可能是导致患儿疾病表型的重要原因。微阵列芯片有助于发现染色体易位时造成的亚显微结构异常。     

Hepatic gene expression profiles associated with fibrosis progression and hepatocarcinogenesis in hepatitis C patients

AIM: To determine fibrosis progression and hepatocellular carcinoma (HCC), using simultaneous gene expression analysis. METHODS: Total RNA samples were extracted from liver biopsies from 19 patients with hepatitis C virus (HCV) infection and 3 patients without HCV infection. Among the 19 HCV-infected patients, 7 and 12 patients had grade Fl-2 and F3-4 fibrosis, respectively. Of the 12 patients with F3-4 fibrosis, 8 had HCC. Gene expression in the liver samples was determined using an oligonucleotide microarray. The following comparisons were performed: normal livers vs HCV-infected livers; F1-2 vs F3-4; and F3-4 with HCC vs F3-4 without HCC. Genes that were differentially expressed between these groups were identified based on signal-to-noise ratios. RESULTS: In the HCV-infected livers, genes involved in immune responses were highly expressed. Expression levels of genes for plasma proteins and drug-metabolizing enzymes were decreased and those of genes involved in the cell cycle and oncogenesis were increased in the F3-4 cases as compared to the F1-2 cases. Among the F3-4 cases, genes involved in carbohydrate metabolism tended to be more highly expressed in patients with HCC than in patients without HCC. CONCLUSION: We identified genes that are associated with fibrosis progression and hepatocarcinogenesis. This information may be used to detect increased carcinogenic potential in the livers of patients with HCV infection.     

IL‐28B (IFN‐λ3) and IFN‐α synergistically inhibit HCV replication

Genetic variation in the IL‐28B (interleukin‐28B; interferon lambda 3) region has been associated with sustained virological response (SVR) rates in patients with chronic hepatitis C treated with peginterferon‐α and ribavirin. However, the mechanisms by which polymorphisms in the IL‐28B gene region affect host antiviral responses are not well understood. Using the HCV 1b and 2a replicon system, we compared the effects of IFN‐λs and IFN‐α on HCV RNA replication. The anti‐HCV effect of IFN‐λ3 and IFN‐α in combination was also assessed. Changes in gene expression induced by IFN‐λ3 and IFN‐α were compared using cDNA microarray analysis. IFN‐λs at concentrations of 1 ng/mL or more exhibited concentration‐ and time‐dependent HCV inhibition. In combination, IFN‐λ3 and IFN‐α had a synergistic anti‐HCV effect; however , no synergistic enhancement was observed for interferon‐stimulated response element (ISRE) activity or upregulation of interferon ‐ stimulated genes (ISGs). With respect to the time course of ISG upregulation, the peak of IFN‐λ3‐induced gene expression occurred later and lasted longer than that induced by IFN‐α. In addition, although the genes upregulated by IFN‐α and IFN‐λ3 were similar to microarray analysis, interferon‐stimulated gene expression appeared early and was prolonged by combined administration of these two IFNs. In conclusion, IFN‐α and IFN‐λ3 in combination showed synergistic anti‐HCV activity in vitro. Differences in time‐dependent upregulation of these genes might contribute to the synergistic antiviral activity.     

cDNA基因芯片数据分析软件的研发进展

数据分析与挖掘是基因芯片研究的关键和难点,而软件是数据分析方法实现的主要手段。我们从以下几个方面对cDNA基因芯片分析软件进行了综述。首先介绍了芯片数据的获取及分析的软件,然后概述了不同统计软件在芯片数据分析中的应用,并详细介绍几种常用的芯片数据分析软件,最后简述了基因网络分析及数据挖掘方面的软件。