Blood Levels of Ammonia and Nitrogen Scavenging Amino Acids in Patients with Inherited Hyperammonemia

Plasma levels of glutamine (456 determinations), alanine (434 determinations), and asparagine (431 determinations) and corresponding ammonia levels (260 determinations) were retrospectively analyzed in 30 patients with hyperammonemia secondary to urea cycle disorders (including 3 patients with amino acid transport defects) and 5 patients with propionic acidemia (PA). All patients had elevated glutamine levels on one or more testing except for 2 patients with severe PA and 1 patient with a mild urea cycle disorder. All but 4 patients with urea cycle disorders showed a maximal glutamine level higher than 100 μmol/dl, and 3 patients had a maximal glutamine level of higher than 200 μmol/dl. The only exceptions were 2 asymptomatic ornithine transcarbamylase (OTC)-deficient females, 1 male with mild OTC deficiency, and 1 patient with citrullinemia (CIT) whose plasma glutamine levels were never above 100 μmol/L. Patients with CIT and argininosuccinic aciduria (ASA) showed statistically significant lower levels of glutamine than patients with other urea cycle disorders. However, the maximal glutamine level did not directly correlate with severity of the disorder and within disorders correlated inversely with severity of outcome. Patients with PA showed statistically significant lower glutamine, alanine, and asparagine levels than patients with urea cycle disorders and the severity of this disorder correlated inversely with plasma glutamine levels. Plasma ammonia levels showed a positive correlation with glutamine in patients with carbamyl phosphate synthetase I and OTC deficiency and a negative correlation in patients with PA. Although, most patients also showed elevated levels of alanine and asparagine, their levels generally did not show a good correlation with glutamine (R²= 0.25 and 0.34, respectively).     

应用SYBR实时荧光定量Real-Time PCR法检测人宫颈癌MCPH1mRNA表达

目的 应用SYBR实时荧光定量RT-PCR法检测MCPH1/BRIT1 mRNA的表达.方法 提取人宫颈癌总RNA,经逆转录PCR获得靶基因(MCPH1)及管家基因(GAPDH)的CDNA,采用SYBR Green 荧光实时定量法检测,以GAPDH基因作为内参,计算各组MCPH1 mRNA的相对表达量.结果 在31...     

肠道病毒71型实时荧光RT-PCR检测方法的建立及临床评价

目的利用实时荧光RT-PCR技术,并通过系统的分析性能和临床性能评价,建立一种早期快速检测肠道病毒71型（EV71）的方法。方法根据EV71基因组中编码衣壳蛋白VP1基因保守区序列设计一对引物和一条荧光探针,利用实时荧光RT-PCR技术建立了检测EV71的方法,并对扩增产物进行分析,同时进行灵敏度、特异性、精密度评价,在此基础上利用不同标本类型共1104例临床样本对本方法和RT-PCR方法进行对比分析。结果本方法可以特异性的检测EV71,而对种属相近的或引起症状相似的其他病毒均无交叉反应。本方法检测灵敏度达到9.22×102PFU/ml,不同浓度样本的Ct值的变异系数在1.4%～2.9%之间。1104例临床样本的研究显示本方法与RT-PCR方法检测结果的总符合率达到96.74%,阳性样本的检出率要高于RT-PCR方法。结论本方法检测EV71具有灵敏度高、特异性强、精密度高、快速简便的特点,并与RT-PCR方法具有很好的符合率,在手足口病的早期快速诊断和疫情监测方面具有很好的应用前景。     

Standardization of a Two-step Real-time Polymerase Chain Reaction Based Method for Species-specific Detection of Medically Important Aspergillus Species

Purpose: Standardization of Aspergillus polymerase chain reaction (PCR) poses two technical challenges (a) standardization of DNA extraction, (b) optimization of PCR against various medically important Aspergillus species. Many cases of aspergillosis go undiagnosed because of relative insensitivity of conventional diagnostic methods such as microscopy, culture or antigen detection. The present study is an attempt to standardize real-time PCR assay for rapid sensitive and specific detection of Aspergillus DNA in EDTA whole blood. Materials and Methods: Three nucleic acid extraction protocols were compared and a two-step real-time PCR assay was developed and validated following the recommendations of the European Aspergillus PCR Initiative in our setup. In the first PCR step (pan-Aspergillus PCR), the target was 28S rDNA gene, whereas in the second step, species specific PCR the targets were beta-tubulin (for Aspergillus fumigatus, Aspergillus flavus, Aspergillus terreus), gene and calmodulin gene (for Aspergillus niger). Results: Species specific identification of four medically important Aspergillus species, namely, A. fumigatus, A. flavus, A. niger and A. terreus were achieved by this PCR. Specificity of the PCR was tested against 34 different DNA source including bacteria, virus, yeast, other Aspergillus sp., other fungal species and for human DNA and had no false-positive reactions. The analytical sensitivity of the PCR was found to be 10² CFU/ml. Conclusion: The present protocol of two-step real-time PCR assays for genus- and species-specific identification for commonly isolated species in whole blood for diagnosis of invasive Aspergillus infections offers a rapid, sensitive and specific assay option and requires clinical validation at multiple centers.     

一种基于高斯匹配滤波法的视网膜图像血管中轴线快速提取算法

目的：研制快速、精确的视网膜血管中轴线（ｖｅｓｓｅｌ ａｘｉａｌ ｓｋｅｌｅｔｏｎ ＶＡＳ）提取算法，以定量分析眼底血管形态改变的细微变化。方法：１．图像预处理（去噪、增强）。２．以经二值化及膨胀后的梯度图像为模板，进行基于高斯匹配滤波法的快速血管提取。３．后处理（细化等）。结果：分别采用本文方法及传统方法对视网膜ＶＡＳ进行提取与结果比较。结论：本文方法具有快速、精确、抗噪声能力强及提取出的ＶＡＳ     

TCT联合HPV检测与多基因甲基化检测在宫颈病变诊断中应用价值分析

目的 分析液基薄层细胞学检测(TCT)联合人乳头瘤病毒(HPV)检测与多基因甲基化检测在宫颈病变诊断中的应用价值.方法 将2018年6月至2020年5月于成都医学院第二附属医院核工业四一六医院妇科就诊的298例宫颈病变高风险患者作为研究对象,均进行TCT联合HPV检测、多基因甲基化检测和阴道镜下宫颈病理活检,以病理结果...     

两种人乳头状瘤病毒检测方法的比较

目的 评价导流杂交和实时荧光定量（real-time）PCR对宫颈癌患者HPV感染检测的临床意义.方法 采用导流杂交和real-time PCR分别对190例患者进行HPV感染检测,并对检测结果进行分析.结果 在190例检测标本中,导流杂交法检测出113例HPV阳性,阳性检出率为59.5％,筛查宫颈癌的敏感度为58.1％,特异度为39.2％,阳性预测值为47.8％,阴性预测值为49.4％.real-time PCR检测出106例阳性,阳性检出率为55.8％,筛查宫颈癌的敏感度为54.8％,特异度为43.3％,阳性预测值为48.1％,阴性预测值为50.0％.导流杂交和real-time PCR检出的HPV阳性率差异无统计学意义,而且一致性检验显示两种方法具有较高的一致性（符合率为87.9％）.结论 本研究结果表明,导流杂交和real-time PCR方法检测HPV未表现出较大的差异,在宫颈癌筛查中可以将两种方法结合使用,以提高检测的准确性,降低漏诊率.     

多重实时荧光定量PCR对9种常见呼吸道病原体检测

目的探讨多重实时荧光定量PCR(MRT-PCR)检测9种常见呼吸道病原体的临床应用价值。方法采用Primer Express3.0(ABI)和Primer3 Input 4.0设计引物和探针建立MRT-PCR法,通过构建质粒标准品分析该方法的最低检出限和特异性。并对204例临床标本中副流感病毒1、2、3型、肺炎支原体、肺炎衣原体、呼吸道合胞病毒、腺病毒、甲型流感病毒、乙型流感病毒进行回顾性检测。结果 MRT-PCR法检测病原体的最低检出限达103copies/m L,特异性达100%,无交叉反应。204例咽拭子标本中,MRT-PCR检出呼吸道合胞病毒23例,副流感病毒1、2、3型13例,腺病毒15例,肺炎支原体15例,肺炎衣原体3例,甲型流感病毒13例与乙型流感病毒6例。该结果与其他试剂报告结果完全一致。结论多重实时荧光定量PCR具有快速、准确、特异性强等特点,在呼吸道病原体检测方面有重要价值。     

基于微电子阻抗技术实时细胞监测系统在细胞凋亡检测时点选择中的应用

目的 探讨基于微电子阻抗技术的实时细胞监测系统用于确定细胞凋亡最佳检测时间点.方法 应用顺铂诱导胶质瘤细胞U251凋亡,使用实时细胞监测系统连续74 h监测不同药物浓度作用于U251后细胞指数的动态变化,根据药物作用时间与细胞指数关系曲线确定凋亡最佳检测时间点,采用流式细胞仪分析细胞凋亡率.结果 通过实时监测发现,2.5μg/mL、5 μg/mL、10μg/mL顺铂分别在作用49 h、60 h和74 h,U251细胞指数值达到最低;在这些时间点,流式细胞仪检测细胞凋亡率分别达到高峰(15.6±1.4)％,(34.2±7.6)％,(63.9±4.6)％.结论 应用实时细胞监测系统可进行细胞凋亡最佳检测时间点的辅助判断.     

实时荧光定量PCR技术在致病菌检测中的应用

目的本文将实时荧光定量PCR(Real-time Q-PCR)法检查致病菌与细菌培养法作比较,探讨对指导临床诊断治疗的意义。方法采用Real-time Q-PCR法和细菌培养法对100份标本进行6个微生物项目的检测,并比较两种方法的灵敏度、特异性和准确性。结果 Real-time Q-PCR法检测结果与细菌培养法,除完全符合的19例标本之外,另有8例用细菌培养法为阴性的标本,用Real-time Q-PCR法检测为阳性。结论 Real-time Q-PCR法较细菌培养法具有准确性好、灵敏度高、特异性强和检测快速等优点,是快速筛查致病菌的理想检测方法之一。     

放射深度的快速算法

在一般情况下,我们使用的深度剂量数据及其它数据都是在假定受照目标的组织密度是均匀的情况下得到的,然而实际上,射线束照射患者时,射线可能是经过脂肪,骨头,肌肉,肺组织及空气等层次,这些组织的密度是不一样的,是不均匀的,从而使这些组织对剂量的分布产生了影响,故必须进行了人体不均匀组织对剂量影响的校正,而在校正方法中,放射深度的计算是一个十分重要的环节,本文对方向深度的算法进行了研究,并提出了一种快速算     

显微图象的快速拼接

作者提出了基于图象匹配的显微图象快速拼接的新方法。拼接分三步完成：１．生成利于配准的梯度图象。２．基于金字塔数据结构的快速匹配。３．进行边界处清除图象拼接处的阶梯。优点是：拼接由计算机自动完成，速度快、精度高，消除了人为误差，并且能提供人工无法实现的拼接处光滑连接。     

Gamma Interferon Release Assays for Detection of Mycobacterium tuberculosis Infection

SUMMARY

Identification and treatment of latent tuberculosis infection (LTBI) can substantially reduce the risk of developing active disease. However, there is no diagnostic gold standard for LTBI. Two tests are available for identification of LTBI: the tuberculin skin test (TST) and the gamma interferon (IFN-γ) release assay (IGRA). Evidence suggests that both TST and IGRA are acceptable but imperfect tests. They represent indirect markers of Mycobacterium tuberculosis exposure and indicate a cellular immune response to M. tuberculosis. Neither test can accurately differentiate between LTBI and active TB, distinguish reactivation from reinfection, or resolve the various stages within the spectrum of M. tuberculosis infection. Both TST and IGRA have reduced sensitivity in immunocompromised patients and have low predictive value for progression to active TB. To maximize the positive predictive value of existing tests, LTBI screening should be reserved for those who are at sufficiently high risk of progressing to disease. Such high-risk individuals may be identifiable by using multivariable risk prediction models that incorporate test results with risk factors and using serial testing to resolve underlying phenotypes. In the longer term, basic research is necessary to identify highly predictive biomarkers.     

缓释bFGF微球体外降解和释药性质研究

通过体外降解释药实验,初步探索bFGF微球在体外的降解释药特点.以PBS液为体外降解和释药介质,初步研究bFGF微球体外降解和释药特点.bFGF微球与空白微球体外降解和质量丧失趋势一致,各个指标之间差异无显著性.约在10d时PLGA的重均分子相对质量下降一半,14～18d时微球质量下降一半,说明微球质量丧失滞后于重均分子相对质量下降.突释期内微球体外释放度仅为19.26%,21d后体外累积释放度高达85.46%,释出bFGF浓度稳定,其平均浓度为(72.47±6.26)ng·mL-1,微球的体外释药规律符合Higuichi方程(r=0.9978).本实验bFGF微球与空白微球降解和吸收趋势一致.聚合物的质量和形态结构变化相对滞后于重均分子相对质量的下降,降解可能主要发生在分子链断裂.     

在体实时血液粘度的测量研究

传统的血液粘度测定方法均采用离体测量方式、存在着测量时间长，测量过程中干扰困素多，测量后的血样被破坏等缺点，因此在测量速度、精度及重复性方面均不令人满意。为此我们提出了一种快速实时测量新鲜血液粘度的新方法，即利用特制针头作为测量毛细管，在采血过程中实现血液粘度的测量。这种新方法具有用血量少、测量快速，重复性好的优点，具有很重要的临床应用价值。