血清胃蛋白酶原检测联合FICE染色内镜在萎缩性胃炎及胃癌诊断中的应用

目的:探讨胃蛋白酶原Ⅰ (Pepsinogen Ⅰ,PGⅠ)、胃蛋白酶原Ⅱ(Pepsinogen Ⅱ,PG Ⅱ)、PGⅠ/PGⅡ(PGR)水平变化结合FICE内镜(Fuji Intelligent ChromoEndoscope,FICE)对提高萎缩性胃炎及胃癌诊断的价值.方法:将856例疾病组患者随机分为两组——白光内镜组和FICE组,以PGI≤70μg/L和PCⅡ≤3为筛查指标,应用ELASA法测定了856例患者的血清胃蛋白酶原,其中血清胃蛋白酶原(Pepsinogen,PG)降低的患者,白光内镜组不作染色按肉眼判断常规取活检,FICE组内镜组在FICE染色后在可疑病灶处取活检.以400例未检测PG的患者作为对照组(仅作白光内镜检查,按肉眼判断常规取活检).结果:HCE组中检出萎缩性胃炎及胃癌的检出率为5.43％;白光组阳性率为3.56％,对照组阳性率为2.5％,三组检出率差异有统计学意义(P＜0.05).结论:血清PGⅠ、PGⅡ、PGR检测结合FICE染色内镜可显著提高萎缩性胃炎及胃癌的检出率.两项技术联合应用,有助于胃癌筛查.     

Eu-Chelate Construct Ultrasensitive Time-Resolved Fluoroimmunoassay-Assay of Pepsinogen Ⅰ

Eu-chelate were used to construct a two-site sandwich-type assay for pepsinogen I (PGI) with time-resolved flu-oroimmunoassay (TRFIA) as a detection technique. On the noncompetitive assay, captured monoclonal antibodies (McAbs) coated on wells were directed against a specific antigenic site on the PGI. Another McAbs, called as labeling McAbs, were prepared with the Eu-chelate of N-(p-isothiocyanatobenzyl)-diethylenetriamine-N, N, N, N-tetraacetie acid and directed against a different antigenic site on the PGI. The fluorescence counts of bound Eu³⁺ -McAbs were measured with the auto DELFIA₁₂₃₅ system. The PGI in sera from healthy volunteers were determined by PGI-TRFIA. The within-run and between-run CVs of the PGI-TRFIA were 1.9% and 4.7%, respectively, and the recovery rate was 102.65%. The assay had a detection limit of 0.05 μg·L⁻¹. The PGI-TRFIA provided a linear response from 3.5 to 328 μg·L⁻¹. The cross-reacting rate with pepsinogen II was negligible. The linear correlation of PGI-TRFIA and radioimmunassay measurements resulted in a correlation coefficient of 0.977. The means of healthy volunteers were 154 ± 43 μg·L⁻¹ for serum PGI. The availability of a highly sensitive, reliable, and convenient method for quantifying PGI will allow investigations into the possible diagnostic value of this analyte in various clinical conditions, including gastric carcinoma, duodenal ulcer, gastritis and severe atrophic gastritis.     

薄膜Lamb波传感器用于胃蛋白酶原I检测

为满足大规模胃癌早期筛查对胃蛋白酶原I(PGI)检测高灵敏度、高效率、操作简单、样品量少的需求,本文构建了一种PGI抗体功能化薄膜型Lamb波生物传感器。对传感器检测腔薄膜进行PGI抗体自组装修饰,传感器检测腔表面修饰的PGI抗体将样品中PGI抗原特异性的捕获并固定在检测腔薄膜表面,Lamb波传感器薄膜表面质量增加导致其A0模式中心频率发生移动,且频率移动量与检测腔表面吸附物质质量增加量正相关,实现对样本中PGI抗原浓度的检测。实验结果表明:PGI抗体功能化薄膜Lamb波生物传感器对PGI抗原实测灵敏度约为102.114 Hz/ng/mL,理论最低检测限(LOD)为0.176ng/mL,单个样本检测时间为40min,与现有基于光学检测法PGI检测技术相比,具有检测系统简单、操作简单、不需要专业人员操作等显著优势,且比多数光学检测法LOD更低,比电化学法PGI检测技术LOD低两个数量级。结果表明,本文提出的PGI抗体免疫功能化薄膜型Lamb波生物传感器对PGI检测且具有检测下限低、灵敏度高、检测效率高、操作简单、无需样品预处理等特点,满足大规模早期胃癌筛查的基本需求。     

Effect of Bifidobacterium bifidum fermented milk on Helicobacter pylori and serum pepsinogen levels in humans

Helicobacter pylori infection is an important risk factor for gastric diseases. Some probiotics are useful for suppressing H. pylori infection. Bifidobacterium bifidum YIT 4007 can improve the experimental gastric injury in rats and the disease stages on the gastric mucosa in peptic ulcer patients. We evaluated the fermented milk using a clone (BF-1) having the stronger ability to survive in the product than this parent strain to clarify the in vitro suppressive effect of BF-1 on H. pylori and the in vivo efficacy of BF-1 fermented milk on H. pylori and gastric health. In the mixed culture assay of BF-1 and H. pylori, the number of pathogens was decreased such that it was not detected after 48 h in the Brucella broth with a decrease in pH values. In the cell culture experiment with human gastric cells, the H. pylori infection-induced IL-8 secretion was suppressed by the preincubation of BF-1. In a human study of 12-wk ingestion (BF-1 group, n = 40; placebo group, n = 39) with a randomized double-blind placebo-control design, the H. pylori urease activity and gastric situation were evaluated using a urea breath test (UBT) and the serum pepsinogen (PG) levels as biomarkers for inflammation or atrophy, respectively. In the H. pylori-positive subjects, the difference (ΔUBT) of the UBT value from the baseline value in the BF-1 group (n = 34) was lower than that in the placebo group (n = 35) at 8 wk. The baseline UBT values showed a negative correlation with ΔUBT values at 8 and 12 wk in the BF-1 group but not in the placebo. In the PG-positive subjects classified by the PG test method, the BF-1 group was lower in ΔUBT values than the placebo group at 8 and 12 wk. In the active gastritis class by PG levels, the BF-1 group was lower in their ΔUBT values than the placebo at 8 and 12 wk. The PG I levels in the BF-1 group were lower than the placebo at 12 wk. The PG II levels in the BF-1 group did not change during the ingestion period, but the placebo was increased. The PG I/II ratios slightly decreased from baseline at 12 and 20 wk in the BF-1 and placebo groups. These patterns were also observed in the H. pylori-positive subjects. The improving rates of upper gastrointestinal symptomatic subjects and total symptom numbers in the BF-1 group were higher than those in the placebo. These results indicate that BF-1 fermented milk may affect H. pylori infection or its activity, gastric mucosal situation, and the emergence of upper gastrointestinal symptoms.