A novel electronic nose for the detection and classification of pesticide residue on apples

Excessive pesticide residues are a serious problem faced by food regulatory authorities, suppliers, and consumers. To assist with this challenge, this work aimed to develop a method of detecting and classifying pesticide residue on fruit samples using an electronic nose, through the application of three different data-recognition algorithms. The apple samples carried various concentrations of two known pesticides, namely cypermethrin and chlorpyrifos. Data collection was performed using a PEN3 electronic nose equipped with 10 metal oxide semiconductor (MOS) sensors. In order to classify and analyze these pesticide residues on the apple samples, principal component analysis (PCA), linear discriminant analysis (LDA), and support vector machine (SVM) results were combined with sensor output responses to realize MOS sensor array data visualization. The results indicated that all three data-recognition algorithms accurately identified the pesticide residues in the apple samples, with the PCA algorithm exhibiting the best classification and discrimination ability. Consequently, this work has shown that the MOS electronic nose, in combination with data-recognition algorithms, can provide support for the rapid and non-destructive identification of pesticide residues in fruits and can provide an effective tool for the detection of pesticide residues in agricultural products.

The MOS electronic nose in combination with data-recognition algorithms can provide an effective tool for the detection of pesticide residues in agricultural products.     

Determination of oligosaccharides in Pompe disease by electrospray ionization tandem mass spectrometry.

BACKGROUND: The development of therapies for lysosomal storage disorders has created a need for biochemical markers to monitor the efficacy of therapy and methods to quantify these markers in biologic samples. In Pompe disease, the concentration of a tetrasaccharide, consisting of four glucose residues, is reputedly increased in urine and plasma, but faster and more sensitive methods are required for the analysis of this, and other oligosaccharides, from biologic fluids. METHODS: We optimized the derivatization of storage oligosaccharides with 1-phenyl-3-methyl-5-pyrazolone for the measurement, by electrospray ionization tandem mass spectrometry, of oligosaccharide concentrations in urine (n = 6), plasma (n = 11), and dried-blood spots (n = 17) from Pompe-affected individuals. Age-matched control samples of urine (n = 10), plasma (n = 28), and blood spots (n = 369) were also analyzed. RESULTS: The mean tetrasaccharide concentration was increased in urine from infantile-onset (0.69-12 mmol/mol of creatinine) and adult-onset (0.22-3.0 mmol/mol of creatinine) Pompe individuals compared with age-matched controls. In plasma samples, an increased tetrasaccharide concentration was observed in some infantile patients (up to 22 micromol/L) compared with age-matched controls (mean, 2.2 micromol/L). The method developed was sensitive enough to determine oligosaccharide concentrations in a single 3-mm blood spot, but no differences were observed between blood spots from control and Pompe-affected individuals. CONCLUSIONS: Measurements of oligosaccharide concentrations in urine by this new method have potential application for the diagnosis and monitoring of patients with Pompe disease. Plasma analysis may have limited application for infantile patients, but analysis of blood spots does not discriminate between controls and affected individuals.     

False-positive microhematuria in dipsticks urinalysis caused by the presence of semen in urine

OBJECTIVES: Positive readings of blood in dipstick urinalysis may indicate trauma or imbalance in hemostasis associated with drug treatment. We evaluated the possibility that the presence of semen in urine may cause false-positive hematuria. DESIGN AND METHODS: Semen specimens obtained from 25 healthy men were directly applied on urine dipsticks for evaluation of the presence of blood. Isolated sperm cells and seminal fluid were also tested. Dipstick analyses were further performed with semen samples diluted in normal urine.Four healthy male volunteers provided urine samples before and immediately after having had sexual relationships. These samples were dipstick tested for the presence of blood. RESULTS: Semen, spermatozoa and seminal fluid gave false positive results for microhematuria following direct application of samples on dipsticks as well as after their suspension in urine (p < 0.00001).Three out of four postcoital urine specimens yielded positive results for blood. CONCLUSIONS: In men, postcoital urine may be falsely "positive" for microhematuria. This may have implication on the management of male patients in emergency situations such as acute coronary syndromes.     

Reagent- and separation-free measurements of urine creatinine concentration using stamping surface enhanced Raman scattering (S-SERS)

We report a novel reagent- and separation-free method for urine creatinine concentration measurement using stamping surface enhanced Raman scattering (S-SERS) technique with nanoporous gold disk (NPGD) plasmonic substrates, a label-free, multiplexed molecular sensing and imaging technique recently developed by us. The performance of this new technology is evaluated by the detection and quantification of creatinine spiked in three different liquids: creatinine in water, mixture of creatinine and urea in water, and creatinine in artificial urine within physiologically relevant concentration ranges. Moreover, the potential application of our method is demonstrated by creatinine concentration measurements in urine samples collected from a mouse model of nephritis. The limit of detection of creatinine was 13.2 nM (0.15 µg/dl) and 0.68 mg/dl in water and urine, respectively. Our method would provide an alternative tool for rapid, cost-effective, and reliable urine analysis for non-invasive diagnosis and monitoring of renal function.OCIS codes: (240.6695) Surface-enhanced Raman scattering, (280.1415) Biological sensing and sensors, (170.5660) Raman spectroscopy     

定量测定HCG的斑点金免疫渗滤试验的临床评价

目的　评价斑点金免疫渗滤试验 (DGIFA)定量测定血清和尿液人绒毛膜促性腺激素 (HCG)的可靠性。方法　分别用化学发光免疫分析法 (CLIA)和DGIFA定量测定HCG试剂盒 (HCG DOT)及DGIFA定量仪测定 4 0份血清样品的HCG含量 ,分别用胶体金免疫层析定性试验 (GICA)和HCG DOT及DGIFA定量仪测定2 70份尿液样品的HCG水平 ;作回收试验和不精密度试验。结果　CLIA和DGIFA定量测定血清样品HCG的相关性好 ;GICA检测阴性的 16 2份尿液样品用HCG DOT测定有 9份为背景红色所致的假阳性 ,1份为血尿导致的假阳性 ,另 2份为阳性 ;GICA检测阳性的 95份和可疑阳性的 13份尿液样品用HCG DOT测定 ,结果均为阳性 ;HCG DOT定量测定高、低浓度HCG血清样品和HCG尿液样品的变异系数 (CV)分别为 5 .38%、4 .13%和 4 .73%、6 .0 1% ;HCG DOT定量测定血清和尿液的HCG回收率分别为 94 .7%和 89.9%。结论　DGIFA定量测定尿液HCG ,对尿液GICA结果可疑者可在妊娠早期作出明确的判断 ;DGIFA定量检测血清和尿液HCG的精密度良好 ,回收率较高 ,适合门急诊应用。     

电子交叉配血技术在手术备血中的应用研究

目的探讨电子交叉配血技术在手术备血中的临床应用。方法 2012年1月-12月分别对供血者和申请手术备血患者进行ABO/RhD血型检测以及抗体筛查。供血者血型正确,抗体筛查阴性,患者二次血型鉴定一致,抗体筛查阴性,按电子交叉配血规则进行配血,完成备血程序。同时用传统血清学交叉配血方法为患者备血,确保血液的相容性并比较两种备血方法的优缺点。结果 7 721份患者血样中7 647份符合电子交叉配血规则,由计算机系统实施电子交叉配血未发现ABO/RhD血型不相容。平均用时3 min,占用血液为手术备血数的50%。用传统血清学方法对7 647份患者血样与供血者血样进行交叉配血,未发现血液不相容。平均用时10 min,占用血液为手术备血数的100%。结论电子交叉配血技术用于手术备血,能节约人力、物力,优化操作流程,提高工作效率与输血安全性,临床应用意义重大。     

Biological Monitoring of Exposure to Metallic Mercury

Abstract

The concentration of mercury was analysed in 418 paired blood and urine samples from 185 workers at three chlorine-alkali plants. The correlation between the concentration of mercury in blood and urine and their dependence on age were examined. There is a considerably larger variability of the mercury levels in urine than in blood. In more than 90% of paired samples, the mercury concentration was higher in urine than in blood. The ratio between the mercury concentration in blood and urine tends to increase with age indicating a weak tendency to age-correlated reduction of renal mercury excretion. As an indicator of exposure to mercury vapour, the mercury content of blood is preferable to that of urine. Active control measures are recommended when the mercury content of blood exceeds 150 nmol/1. When the blood level exceeds 300 nmol/1 occupational mercury exposure ought to be stopped until the level has decreased to below 100 nmol/1.     

头孢抗生素对干化学法检测尿红细胞的影响

目的观察尿中各类头孢抗生素对干化学法检测尿红细胞定性实验的干扰作用。方法将尿液、红细胞、各类头孢抗生素按一定比例配制,用尿液干化学分析仪进行测定。结果尿中各类头孢抗生素浓度达到10mg／ml时,可使尿测定为“＋”的红细胞降低为“±”。当尿中头孢浓度达20mg/ml,可致假阴性;＂-3尿中浓度头孢抗生素达10mg／ml时,可使原测定“＋＋”的红细胞降低为“＋”,当尿中头孢浓度达20mg／ml或超过20mg／ml,可使结果降低为“±”,甚至出现假阴性;当尿中头孢浓度达20mg/ml,可使原测定为“＋＋＋”的红细胞结果降低。结论尿液中的头孢抗生素浓度严重影响干化学法检测红细胞的定性结果,并随着尿液中头孢类药物浓度的增加,干扰度随之增加,甚至可致尿红细胞检测呈假阴性。     

两种尿沉渣自动分析仪的结果比较

目的比较AVE-763全自动尿液有形成分分析仪（简称AVE-763）和IQ-200全自动尿沉渣分析仪（简称IQ-200）的结果比较,评价AVE-763性能及临床应用价值。方法用人工配制的高、低值标本测定仪器的携带污染率,并随机收集653例住院患者的中段尿标本,分别用AVE-763和IQ-200检测白细胞、红细胞、上皮细胞及管型并作对比分析,同时对AVE-763进行人工辅助判断前后的比较。结果 AVE-763检测红细胞、白细胞的携带污染率均≤2%,AVE-763和IQ-200对白细胞、红细胞、上皮细胞、管型的检测阳性率无明显差异。从AVE-763对白细胞、红细胞、上皮细胞、管型检测人工辅助判断前后比较说明此功能对保证结果准确有着重要作用。结论 AVE-763结果稳定、操作简便,为一款较好的尿沉渣检测过筛仪器。     

尿液分析试纸在腹水感染中的诊断价值

目的 研究尿液分析试纸在腹水感染中的诊断价值.方法 选择不同病因形成的腹水标本33例,应用尿液分析试纸对腹水标本进行白细胞检测,同时与手工计数法作比较,并作统计学分析.结果 尿试纸检验结果阳性率为54.5%,传统方法结果阳性率为57.6%.两种方法阳性率比较,差异无统计学意义(P>0.05).应用尿液分析试纸结果的敏感性78.95%,特异性78.57%,阳性预测值83.33%,阴性预测值73.33%,尿液分析试纸对诊断腹水感染的敏感性及特异性均较高.计算kappa值为0.57,尿液分析试纸与手工计数法两种方法一致性较好.结论 尿液分析试纸检测法具有快速、操作简单、结果比较可靠等优势,在临床上应用于腹水感染的初步筛检有一定的可行性.     

荧光定量PCR检测UCA1mRNA方法学建立及临床评估

目的建立荧光定量体外检测UCA1mRNA的实验方法。方法用已构建的peDNA3．1／UCA1重组质粒作为标准品,建立实时荧光定量PCR检测尿液、血液标本UCA1RNA的方法,并进行方法学评价。应用此方法检测24例膀胱癌组、30例泌尿系统非膀胱癌组（包括。肾癌、前列腺癌）以及20例健康对照组的尿液和血液中UCA1mRNA的表达,并进行临床评估。结果膀胱癌患者血、尿标本的阳性符合率分别为91．67％和87．50％,而泌尿系统非膀胱癌患者血、尿标本的阳性符合率为63．33％和66．67％,10份消化系统肿瘤（肝癌、胃癌、食管癌、直肠癌）患者全血标本、10份肺癌患者的全血标本、20份健康人标本全血和尿液标本均为阴性。膀胱癌组阳性率高于其它系统肿瘤和健康对照组（P〈0．01）。在膀胱癌组中,UCA1mRNA的表达与临床分期和病理分级有显著的相关性（P〈0．05）。结论本研究成功建立了可用生物体液（如血液、尿液等）检测UCA1mRNA的技术。     

IQ200ELITE尿沉渣分析仪检测红细胞的方法学评价

目的评价IQ200 ELITE尿沉渣分析仪的性能,探讨其临床应用价值。方法使用IQ200 ELITE尿沉渣分析仪和Fast-Read尿沉渣计数板计数血细胞悬液和尿样标本中红细胞数并进行统计分析。结果 IQ200检测红细胞的线性范围大致为7~3 800,批内精密度为3.8%,批间精密度为4.7%,日间精密度为5.6%,总重复性为4.91%,携带污染率在0.00%~0.31%之间,平均0.21%,与Fast-Read尿沉渣计数板计数红细胞数比较不存在明显恒定的系统误差,但易受小圆形草酸钙的干扰。结论 IQ200具有良好的线性,较宽的线性范围,精密度较高,携带污染率极低,不存在明显恒定的系统误差,可用于过筛检查和治疗监控,具有较高的临床应用价值。     

透明质酸测定鉴别诊断肾细胞癌和移行细胞癌

目的:探讨并评价血、尿透明质酸的测定在肾癌、肾盂癌鉴别诊断中的价值。方法:采集41份血液和尿液样本,其中肾癌17例,肾盂癌14例,正常人10例;采用酶联免疫法(ELISA)测定尿液和血液样本中透明质酸的浓度;采用化学发光法测定尿液中蛋白浓度,用SPSS 11.0分析血液、校正尿液的透明质酸浓度及其比值。结果:在41份血液样本中,各组数据间差异无统计学意义;41份尿液样本中,比较经尿蛋白浓度校正后的尿透明质酸浓度,肾癌组与肾盂癌组差异有统计学意义(P<0.01);比较41例样本的血尿透明质酸浓度比值,肾癌组与肾盂癌组差异有统计学意义(P<0.01)。结论:肾盂癌患者尿液中校正透明质酸浓度明显高于正常人和肾癌患者。尿液透明质酸浓度可作为移行细胞癌的肿瘤标志物,用于肾盂癌的诊断及其与肾癌的鉴别诊断。     

西安市6000例健康体检者尿液检测结果分析

目的了解西安市健康体检人群中尿液分析异常结果的检出率。方法对6 000例尿液标本进行干化学分析,对各项结果进行分类统计。结果尿液分析阳性(±~++++)检出排序为:白细胞、血、蛋白质、胆红素、酮体、葡萄糖、亚硝酸盐。弱阳性(±或trace)检出排序为:血、白细胞、酮体、蛋白质、胆红素,葡萄糖和亚硝酸盐未发现弱阳性。检测阳性项目总计1 023项,弱阳性项目总计879项。在检测项目中,白细胞、血、蛋白质、亚硝酸盐等阳性率在不同性别和不同年龄间差异有统计学意义(P<0.05)。结论尿液分析是不可缺少的重要检测项目,适用于健康普查及疾病的早期发现。     

Relationship of blood pressure to sodium and potassium excretion in Japanese women

The cross-sectional association of blood pressure with urinary sodium and potassium excretion was investigated with a stepwise regression analysis. Spot urine of 7441 females between 40 and 69 years was collected from 169 municipalities (88 urban and 81 rural) covering all prefectures in Japan. The filter paper sampling technique for urine was used to collect samples of subjects from March to December in 1985. Spot urine samples were analyzed for sodium, potassium and creatinine. In addition, 24-hr sodium and potassium excretions were estimated by predictive equations. Blood pressure, sodium excretion and sodium potassium ratios were higher in rural areas than in urban areas. Consistent positive correlations between urinary sodium and blood pressure, and negative correlations between urinary potassium and blood pressure were observed in the whole country of Japan, in both urban and rural areas, and also in separate observations of twelve regions in Japan with some exceptions. When compared in standardized partial regression coefficients, relative effects of potassium on systolic blood pressure were higher than those of sodium in the whole of Japan, in urban and rural areas, and in five among the twelve regions. The present Japanese study confirmed a positive within-population relationship between sodium excretion and blood pressure and a negative relationship between potassium excretion and blood pressure.     

Automated urinalysis: first experiences and a comparison between the Iris iQ200 urine microscopy system, the Sysmex UF-100 flow cytometer and manual microscopic particle counting.

BACKGROUND: Automated analysis of insoluble urine components can reduce the workload of conventional microscopic examination of urine sediment and is possibly helpful for standardization. We compared the diagnostic performance of two automated urine sediment analyzers and combined dipstick/automated urine analysis with that of the traditional dipstick/microscopy algorithm. METHODS: A total of 332 specimens were collected and analyzed for insoluble urine components by microscopy and automated analyzers, namely the Iris iQ200 (Iris Diagnostics) and the UF-100 flow cytometer (Sysmex). RESULTS: The coefficients of variation for day-to-day quality control of the iQ200 and UF-100 analyzers were 6.5% and 5.5%, respectively, for red blood cells. We reached accuracy ranging from 68% (bacteria) to 97% (yeast) for the iQ200 and from 42% (bacteria) to 93% (yeast) for the UF-100. The combination of dipstick and automated urine sediment analysis increased the sensitivity of screening to approximately 98%. CONCLUSIONS: We conclude that automated urine sediment analysis is sufficiently precise and improves the workflow in a routine laboratory. In addition, it allows sediment analysis of all urine samples and thereby helps to detect pathological samples that would have been missed in the conventional two-step procedure according to the European guidelines. Although it is not a substitute for microscopic sediment examination, it can, when combined with dipstick testing, reduce the number of specimens submitted to microscopy. Visual microscopy is still required for some samples, namely, dysmorphic erythrocytes, yeasts, Trichomonas, oval fat bodies, differentiation of casts and certain crystals.     

肾移植后BK病毒感染者实时荧光定量PCR检测

背景：对于BK病毒感染、BK病毒相关性肾病的认识缺乏规范的实验室诊断程序和标准化的无创性检验方法。目的：建立肾移植后患者尿液和外周血BK病毒感染负荷实时荧光定量PCR检测方法。方法：针对BK病毒基因组,自主设计特异性引物BKV-F和BKV-R,Taqman荧光探针BKV-P,Taqman荧光探针BKV-P的5’端标记有荧光基团,在除5’端外的任意一个位置上标记有淬灭基团;然后处理待测样本,进行PCR反应。结果与结论：将检测阳性的扩增产物进行基因测序,测序结果经BLAST比对后证实为BK病毒基因序列;利用上述方法对56份样本进行检测,其中,20份BK病毒血清样本及20份BK病毒尿液样本检测均为阳性,有S型扩增曲线。动态范围测定显示在103～1010copies/mL之间标准曲线具有良好的相关性。5份健康人尿液样本,5份血液样本及6份临床常见的其他病原体血液样本检测均为阴性,无S型扩增曲线。结果表明该方法可进行定性、定量检测,特异性好,反应快速,一般30min即可得到反应结果,并且成本低、假阳性少。     

肾移植后BK病毒感染者实时荧光定量PCR检测

背景:对于BK病毒感染、BK病毒相关性肾病的认识缺乏规范的实验室诊断程序和标准化的无创性检验方法.目的:建立肾移植后患者尿液和外周血BK病毒感染负荷实时荧光定量PCR检测方法.方法:针对BK病毒基因组,自主设计特异性引物BKV-F和BKV-R,Taqman荧光探针BKV-P,Taqman荧光探针BKV-P的5'端标记有荧光基团,在除5'端外的任意一个位置上标记有淬灭基团;然后处理待测样本,进行PCR反应.结果与结论:将检测阳性的扩增产物进行基因测序,测序结果经BLAST比对后证实为BK病毒基因序列;利用上述方法对56份样本进行检测,其中,20份BK病毒血清样本及20份BK病毒尿液样本检测均为阳性,有S型扩增曲线.动态范围测定显示在103~1010 copies/mL之间标准曲线具有良好的相关性.5份健康人尿液样本,5份血液样本及6份临床常见的其他病原体血液样本检测均为阴性,无S型扩增曲线.结果表明该方法可进行定性、定量检测,特异性好,反应快速,一般30 min即可得到反应结果,并且成本低、假阳性少.     

Urine flow cytometry and detection of glomerular hematuria.

BACKGROUND: The UF-100 is a flow cytometer designed for automated cellular urinalysis. In this study, the usefulness of the UF-100 in laboratory investigation into the origin of hematuria was evaluated. METHODS: Results from flow cytometric urinalysis were used to classify urinary red blood cells (RBCs) according to glomerular and non-glomerular origin and the classification was compared to the patient's clinical diagnosis as the gold standard. In parallel, microscopic sediment analysis was carried out. RESULTS: A total of 206 urine samples from 129 patients were analyzed (127 from patients with glomerular hematuria, 79 from patients with non-glomerular hematuria). Of these, 136 samples (92 patients) showed overt hematuria (>or=20 RBC/microL). Urine flow cytometry correctly classified 61% (sediment analysis 69%) of urine samples with overt hematuria. If inconclusive results are excluded, the UF-100 correctly diagnosed 85% (sediment analysis 98%) of urine samples with overt hematuria. The UF-100 and microscopic sediment analysis both showed sensitivity of 99% for the detection of glomerular hematuria. The specificity of the UF-100 for the detection of glomerular bleeding was lower (42%) than the specificity of microscopic sediment analysis (93%). CONCLUSIONS: Owing to its low specificity, the UF-100 showed limited capacity to discriminate glomerular from non-glomerular causes of hematuria in a population with a high incidence of renal disease. Therefore, extensive microscopic urinalysis remains necessary to assess the origin of hematuria.