电离测量法14C-尿素呼气试验诊断幽门螺杆菌的感染

目的建立一种电离测量法14G尿素呼气试验,用于快速检测幽门螺杆菌感染.方法口服14C尿素胶囊后,呼气14CO2直接采集于Ca(OH)2干粉垫上,14C吸收量以双盖勒计数检测.结果与经典液体闪烁测量法比较.81例幽门螺杆菌阳性和102例阴性病人接受验证试验.结果电离测量法诊断的准确性为略低于液体闪烁测量法的,但统计学差异无显著性(92.3%和96.2%,P＞0.05),标本重复测试结论变更率略高于液体闪烁测量,差异无显著性(6.0%和2.2%,P＞0.05).结论电离测量法14C-尿素呼气试验可用于医生办公室现场快速幽门螺杆菌感染诊断.     

体外~(14)C-尿素呼气试验检测胃内幽门螺杆菌感染研究

目的　建立诊断胃内幽门螺杆菌感染 (Hp)的体外 1 4 C-尿素呼气试验 (1 4 C- U BT)。方法　 47例 Hp阳性和 32例 Hp阴性患者接受测试 ,用口服微量胃液采集胶囊的办法收集胃液标本于一 10 m l无菌试管内 ,加入生理盐水 0 .5 m l和 18.5 k Bq1 4 C-尿素后立即加橡皮塞密封试管 ,室温放置反应 3h,注射器经橡皮塞注入 2 M H2 SO41.0 ml,使 1 4 CO2 释出。同一注射器回抽气体并立即注入装有 6 .5 ml的 1 4 CO2 搜集闪烁剂液闪瓶内搜集 1 4 CO2 ,最后在液体闪烁计数仪上作 1 4 C放射性测定。结果　 47例 Hp阳性病人 1 4 C放射性几何均数为 5 30 dpm,而 32例 Hp阴性者结果为 2 1dpm,二者相差 2 3倍 (Wilcoxon秩和检验 ,u=5 .5 976 ,P<0 .0 1)。以受试者工作特征曲线分析法得出判别阈值为 75 dpm ,对 Hp诊断的敏感性和特异性为 92 %(4 3/ 47)和 91% (2 9/ 32 )。结论　体外 1 4 C- UBT诊断 Hp感染具有高度的准确性 ,无放射性损伤之虞 ,可适用于临床诊断。     

体外^14C—尿素呼气试验检测胃内幽门螺杆菌感染研究

目的 建立诊断胃内幽门螺杆菌感染（Ｈｐ）的体外＾１４Ｃ－尿素呼气试验（＾１４Ｃ－ＵＢＴ）。方法 ４７例Ｈｐ阳性和３２例Ｈｐ阴性患者接受测试,用口服微量液采集胶囊的办法收集胃液标本于－１０ｍｌ无菌试管内,加入生理盐水０．５ｍｌ和１８．５ｋＢｑ＾１４Ｃ－尿素后立即加橡皮塞密封试管,室温放置反应３ｈ,注射器经橡皮塞注入２ＭＨ２ＳＯ３１．０ｍｌ,使＾１４ＣＯ＾２释出。同一注射器回抽气体并立即注入装有６．５ｍｌ的＾１４ＣＯ２搜集闪烁剂液闪瓶内搜集＾１４ＣＯ＾２,最后在液体闪烁计数仪上作＾１４Ｃ放射性测定。结果 ４７例Ｈｐ阳性病人＾１４Ｃ放射性几何均数为５３０ｄｐｍ,而３２例Ｈｐ阴性者结果为２１ｄｐｍ,二者相差２３倍（Ｗｉｌｃｏｘｏｎ铁和检验,ｕ＝５．５９７６,Ｐ〈０．０１）。以受试者工作特征曲线分析法得出判别阈值为７５ｄ     

胃内酸化消除胃内细菌过生长造成的14C-尿素呼气试验假阳性

目的 :观察胃内细菌过生长是否可以引起 1 4C-尿素呼气试验假阳性 ,同时胃内酸化是否能即刻消除这种影响。方法 :5 8名胃黏膜组织学 Hp阴性、常规 1 4C- UBT( U BT- 1)也阴性的溃疡样型功能性消化不良的病人口服雷贝拉唑 2 0 mg/ d、共 7d。于第 6天常规 1 4C- UBT( U BT- 2 )。U BT- 2阳性者于第 7天再进行一次改良的 1 4C- U BT( U BT- 3) ,方法是在服用 1 4C-尿素胶囊前 2 0 m in和服用胶囊时各加饮 15 0 m l0 .1mol/ L的柠檬酸水。比较三次 U BT的 1 4CO2 呼出率。结果 :雷贝拉唑明显增加 Hp阴性病人 1 4CO2 呼出率 ,U BT- 1为 ( 2 4 .0± 10 .8) dpm / mm ol CO2 ,U BT- 2为 ( 6 3.6± 16 .8) dpm / m mol CO2 ( ( t=2 .310 ,P<0 .0 5 )。U BT- 2有 9例假阳性 ( 9/ 5 8,16 % )。但胃内酸化后的 UBT- 3的 1 4CO2 呼出率又落至 ( 2 1.0± 7.8) dpm/mm ol CO2 ( ( t=2 .0 6 8,P<0 .0 5 ) ,9例假阳性者又恢复真阴性。结论 :胃内细菌过生长可以引起 1 4C-尿素呼气试验假阳性 ,同时胃内酸化能即刻消除这种影响     

慢性腹痛患儿C~(13)-尿素呼气试验与胃镜检查的临床意义

目的了解慢性腹痛患儿幽门螺杆菌(H.pylori)的感染状态及幽门螺杆菌感染患儿内镜下表现的特点。方法应用C13尿素呼气试验,对905例以慢性腹痛为主要症状的患儿进行检测,对C13呼气试验阳性者进行电子胃镜检查。结果905例慢性腹痛患儿中H.pylori呈阳性185例(20.44%),随年龄增长,其H.pylori阳性率升高,学年组已达高峰。对H.pylori阳性者进行胃镜检查结果显示十二指肠隆起病变47例占25.40%,结节性胃炎41例占22.1%,慢性浅表性`胃炎38例占20.5%,结节性胃炎伴十二指肠隆起病变23例占12.43%,十二指肠球部溃疡23例占12.4%。胃溃疡7例,占3.7%(其中包括1例复合性溃疡),结节性胃炎伴十二指肠炎6例,占3.2%。结论H.pylori感染为小儿慢性腹痛的主要原因之一,也是导致慢性胃炎及消化性溃疡的主要原因之一。C13尿素呼气试验方便,快速,无痛苦,无放射性,是一较好的H.pylori检测方法;对既有消化道症状同时C13呼气试验阳性者进行胃镜检查能够协助临床诊断及治疗。     

固相闪烁晶体用于液闪测量的评价

本文介绍两种固相闪烁晶体制样及测量方法并与乳化剂闪烁液相比较。 ³H, ¹⁴C, ¹²⁵I及 ³⁵S其计数效率(E％)分别达34.1％,89.9％,60.3％及77.4％。液相及两种固相闪烁体间的变异系数(CV％)范围为5.1％—10.3％,同系列样品对不同厂家型号的液闪谱仪,测量效率趋一致。其测量效率、精确度、平行度等近于或优于液相测量。对数波谱分析表明无需淬灭校正并可用于双标记测量。用固相闪烁体制样不需闪烁液,故无毒、无污染、污物体积小且使用方便,克服了液体闪烁测量的不足。因此是较理想的可推广的新型样品制备与测量技术。     

常规胃内酸化可提高14C-UBT诊断的准确性

目的观察在进行14C-尿素呼气试验(UBT)时常规进行胃内酸化是否可提高14C-UBT试验诊断的准确性。方法250例因消化不良需要进行胃镜检查的门诊患者分为传统14C-UBT组和酸化14C-UBT组。传统14C-UBT组按常规方法进行试验,酸化14C-UBT组的检测过程与传统14C-UBT基本相同,唯一的差别是以0.1 mol/L的柠檬酸水200 m l(加少量甜味剂)送服14C尿素胶囊。比较2次UBT的14CO2呼出量、诊断的敏感性、特异性及准确性。结果(1)2组幽门螺杆菌(H.pylori)阳性的患者平均14CO2呼出量酸化组高于传统组,而2组H.pylori阴性的患者平均14CO2呼出量酸化组低于传统组,且统计学上差异均有显著性(P<0.05)。(2)传统14C-UBT组诊断的准确性、特异性、敏感性分别为92%、91%、92%;而酸化14C-UBT组分别为98.5%、100%、98%。2组间的诊断准确性及特异性差异有显著性(P<0.05);敏感性差异无显著性(P>0.05)。结论在14C-尿素呼气试验时常规进行胃内酸化可提高诊断的准确性。     

甲烷氢呼气试验对原发性肾病综合征患儿小肠细菌过度生长的检测

通过甲烷氢呼气试验对原发性肾病综合征（PNS）患儿小肠细菌过度生长情况进行评估,探索PNS患儿小肠细菌情况。

本研究于2021年3月至2022年3月招募30例PNS患儿（PNS组）和34例体检者（对照组）为研究对象,采用甲烷氢呼气试验检测受试者小肠的菌群生长情况。分析PNS与小肠细菌生长情况的相关性。

PNS组共有16名PNS患儿合并小肠细菌过度生长（SIBO）,SIBO患病率为53.3%（95% CI：11.1%～89.7%）;而对照组有26.5%的儿童患有SIBO,组间差异有统计学意义（χ² = 4.831 4,P = 0.027 9）。两组儿童年龄、性别、常住地比较差异均无统计学意义（均P＞0.05）。PNS合并SIBO的患儿白细胞水平显著低于未合并SIBO的患儿（F = 6.279 7,P = 0.020 1）。Pearson分析显示,PNS组中SIBO阳性患儿服用乳果糖后呼出气体变化量与血清中胆固醇水平具有相关性（P＜0.05）。

PNS患儿更容易发生SIBO,临床可对此类患者进行针对性治疗。

     

一种适宜微量全血检测HBV-DNA裂解液的评价

通过核裂解液与氯仿／酚处理法以及与另四个生产厂家的裂解液对指尖全血处理法的比较,检测ＨＢＶ－ＤＮＡ的结果表明：该裂解液可更有效除去全血中对Ｔａｑ酶有抑制性作用的血卟啉,扩增结果与用血清作标本结果一致,表明指尖全血用这种裂解液处理完全替代血清标本用于ＨＢＶ－ＤＮＡ的ＰＣＲ检测。     

苦参水提液的杀菌效果

采用悬液定量杀菌试验,对苦参水提液的杀菌效果进行实验室研究。研究发现,苦参水提液对金黄色葡萄球菌、大肠埃希菌、枯草芽胞杆菌、白假丝酵母菌和黑曲霉均具有明显的杀菌作用。通过模拟现场试验,苦参水提液起到了显著地杀菌效果。     

13C-urea breath test to assess Helicobacter pylori bacterial load

BACKGROUND: Some authors have reported, using different protocols, that 13C-urea breath test (13C-UBT) is capable of assessing the intragastric Helicobacter pylori bacterial load, whereas others have not confirmed these data. Our aim is to evaluate the correlation between 13C-UBT values and H. pylori bacterial load. MATERIALS AND METHODS: One hundred ninety-two patients diagnosed H. pylori-positive by rapid urease test, histology, and 13C-UBT were enrolled. H. pylori bacterial load (H. pylori score) and gastritis activity (activity score) were evaluated according to the Updated Sydney System. 13C-UBT was performed according to the European Standard Protocol. Breath samples were obtained every 10 minutes for 60 minutes in 52 patients and at 30 minutes (T30) in 140 patients and analyzed by mass spectrometry. RESULTS: At T30, mean +/- SD excess delta 13CO2 excretion was 17.4 +/- 1.1, 29.9 +/- 2.2, and 48.7 +/- 4.8 in patients with H. pylori scores 1, 2, and 3, respectively. This difference was statistically significant: H. pylori score 1 versus 2, p < .005; score 1 versus 3, p < .05; score 2 versus 3, p < .05. A significant positive correlation (G = 0.59) was found between H. pylori score and activity score of chronic gastritis. At T40 and T50 significant correlation between mean excess delta 13CO2 excretion and bacterial load was achieved only in patients with H. pylori scores 1 and 3. CONCLUSIONS: 13C-UBT European Standard Protocol values correlate with H. pylori bacterial load and the activity of gastritis at T30 breath sampling time.     

Role of 13C-urea breath test in experimental model of Helicobacter pylori infection in mice

Background: Animal models have been widely used to study Helicobacter pylori infection. Evaluation of H. pylori infection status following experimental inoculation of mice usually requires euthanasia. The ¹³C‐urea breath test (¹³C‐UBT) is both sensitive and specific for detection of H. pylori in humans. Thus, it would be very useful to have such a test with the same accuracy for the follow‐up of this infection in animal models of gastric infection. Accordingly, the purpose of this study was to develop and evaluate a ¹³C‐UBT method for following the course of H. pylori infection in a mouse model. Material and Methods: A total of 50 female C57BL/6 mice were gavaged three times with either 10⁸ colony‐forming units of H. pylori (n = 29) or saline solution only (n = 21). After 2 months of infection, mice were fasted for 14 hours and ¹³C‐UBT was performed using 300 μg of ¹³C‐urea. The mice were killed, and the stomach was removed and processed for immunohistochemistry and PCR. Results: The optimal time for breath sample collection in mice was found to be 15 minutes. The ¹³C‐UBT cutoff was set at 3.0‰δPDB. Using PCR as the gold standard, the sensitivity of ¹³C‐UBT and immunohistochemistry was 96.6 and 72.4%, respectively, while the specificity was 85.7 and 95.2%, respectively. Conclusions: ¹³C‐UBT was shown to be a reliable method for the detection of H. pylori infection in C57BL/6 mice and was even more accurate than immunohistochemistry. The use of ¹³C‐UBT in the mouse model of H. pylori infection can be very useful to detect the bacterium without the need to kill the animals in long‐term time course studies.     

13C-urea breath test results in pigs challenged with Helicobacter pylori or other urease producing bacteria

The gastric bacterial flora and its influence on the 13C-urea breath test (UBT) for detection of Helicobacter pylori infection was studied in a pig model. Seven SPF minipigs were used. H. pylori or a mix of other urease positive bacteria were administered orally. UBT, serum and biopsies for histology and culture were collected. Our results show that UBT is not specific for H. pylori in pigs as the gastric bacterial flora is responsible for the high UBT values observed. Furthermore, the Ellegaard G?ttingen SPF minipigs are not useful in an animal model for H. pylori studies.     

13C-urea breath test during hospitalization for the diagnosis of Helicobacter pylori infection in peptic ulcer bleeding

Objective: To evaluate the accuracy of ¹³C‐urea breath test (UBT) to detect Helicobacter pylori infection in patients hospitalized with peptic ulcer bleeding and treated with proton pump inhibitors (PPIs). Methods: Patients hospitalized with peptic ulcer bleeding, and treated with omeprazole, had a first UBT performed the day after resuming oral feeding. Patients with a negative UBT during hospitalization underwent a repeated UBT 15 days after stopping PPIs. Results: The first UBT during hospitalization was positive in 86% of 131 patients. Time between admission and performance of the test was longer in patients with negative versus positive UBT (5.2 ± 0.7 versus 4.3 ± 0.5 days; p < .001). The repeated UBT became positive in 15 of 18 (83%) patients with a negative first UBT. In the multivariate analysis, the only variable associated with a negative first UBT was the time elapsed between admission and performance of the test (odds ratio = 6.6; 95%CI = 2.9–15.1). Conclusion: Most H. pylori‐positive patients with ulcer bleeding have a positive UBT (performed just after resuming oral feeding) despite previous treatment with high‐dose PPIs. Nevertheless, to preclude false‐negative results due to PPI therapy, the UBT should be performed as early as possible. If the infection cannot be demonstrated with this first UBT, H. pylori still needs to be definitively excluded with a second UBT performed after stopping PPIs.     

13C-urea breath test for the diagnosis of Helicobacter pylori infection in children: a systematic review and meta-analysis

Background: The ¹³C‐urea breath test (¹³C‐UBT) is a safe, noninvasive and reliable method for diagnosing H. pylori infection in adults. However, the test has shown variable accuracy in the pediatric population, especially in young children. We aimed to carry out a systematic review and meta‐analysis to evaluate the performance of the ¹³C‐UBT diagnostic test for H. pylori infection in children. Methods: We conducted a systematic review of the PubMed, Embase and Liliacs databases including studies from January 1998 to May 2009. Selection criteria included studies with at least 30 children and reporting the comparison of ¹³C‐UBT against a gold standard for H. pylori diagnosis. Thirty‐one articles and 135 studies were included for analysis. Children were stratified in subgroups of <6 and ≥6 years of age, and we considered variables such as type of meal, cutoff value, tracer dose, and delta time for the analysis. Discussion: The ¹³C‐UBT performance meta‐analyses showed 1, good accuracy in all ages combined (sensitivity 95.9%, specificity 95.7%, LR+ 17.4, LR? 0.06, diagnostic odds ratio (DOR) 424.9), 2, high accuracy in children >6 years (sensitivity 96.6%, specificity 97.7%, LR+ 42.6, LR? 0.04, DOR 1042.7), 3, greater variability in accuracy estimates and on average a few percentage points lower, particularly specificity, in children ≤6 years (sensitivity 95%, specificity 93.5%, LR+ 11.7, LR? 0.12, DOR 224.8). Therefore, the meta‐analysis shows that the ¹³C‐UBT test is less accurate for the diagnosis of H. pylori infection in young children, but adjusting cutoff value, pretest meal, and urea dose, this accuracy can be improved.     

Role of noninvasive tests (C-urea breath test and stool antigen test) as additional tools in diagnosis of Helicobacter pylori infection in patients with atrophic body gastritis

BACKGROUND: Detection of Helicobacter pylori infection in atrophic body gastritis (ABG) is difficult, as during progression of body atrophy, H. pylori disappears. AIM: To increase the diagnostic yield of detection of active H. pylori infection in atrophic body gastritis patients by using noninvasive tests such as (13)C-Urea Breath Test ((13)C-UBT) and H. pylori stool antigen test (HpSA) would be useful. PATIENTS: 27 consecutive patients with newly-diagnosed atrophic body gastritis (19F/7M, age 27-73 years). METHODS: Gastroscopy with biopsies (antrum n = 3, body n = 3) and histology according to updated Sydney system, H. pylori IgG serology, (13)C-UBT, and HpSA. RESULTS: All tests used in the diagnosis of H. pylori infection were in agreement in 9/27 atrophic body gastritis patients (33.3%), being all positive in four (14.8%) and all negative in five patients (18.5%). Ten of the 27 (37%) patients were Giemsa stain-positive and serology-positive (group I). Seventeen of the 27 (63%) patients were Giemsa stain-negative: 5/17 with positive serology (group II) and 12/17 with negative serology (group III). In group I, 5/10 (50%) were (13)C-UBT positive and 4/10 (40%) HpSA positive. In group II, two patients were (13)C-UBT positive, but all were HpSA negative. Also in group III, all patients were HpSA negative, but one had a positive (13)C-UBT. CONCLUSIONS: In atrophic body gastritis patients, neither (13)C-UBT nor HpSA per se add useful information regarding active H. pylori infection, but these noninvasive tests may be important in combination with histology and serology to define the H. pylori status in some atrophic body gastritis patients.     

Serology and urea breath test in the diagnosis ofH. pylori infection

Helicobacter pylori is a chronic infection that has the potential for causing and initiating serious gastric-disease. Specific treatment can be successful in eradication of the infection but is currently complex which hampers essential patient compliance. Therefore, the accurate detection ofH. pylori and. importantly, the post-treatment check for cure is vital in the effective management of this infection. This is especially true in cases of asymptomatic individuals. Serology is now a simple ELISA with a high degree of accuracy and has been shown to be useful as a screening tool prior to endoscopy in selected cases. The urea breath test, either using C¹³ or C¹⁴. is a sensitive test easily applied and is the test of choice for post-treatment check for cure. It is also the gold standard for the validation of serology in different populations.     

Hydrogen breath test as a simple noninvasive method for evaluation of carbohydrate malabsorption during exercise

The aim of this study was to examine hydrogen (H₂) production with the hydrogen breath test (HBT) after ingesting primarily digestible carbohydrate (CHO) during 3 h of 75% maximal oxygen consumption exercise. This was done to indicate CHO overflow in the colon which may occur when gastric emptying, intestinal transit and CHO absorption are not matched and CHO accumulates in the colon where it is subject to bacterial degradation. Further, this study was designed to assess breath H₂ production as a function of the type of CHO ingested and the type of exercise. A group of 32 male triathletes performed three exercise trials at 1-week intervals with either a semi-solid (S) intake, an equal energy fluid intake (F) or a fluid placebo (P). Each trial consisted of cycling (sessions 1 and 3) and running (sessions 2 and 4). The mixed-expired H₂ concentrations in the resting and recovery periods (5 min after each session) did not change significantly in. time and did not differ among intakes. There were also no significant differences in H₂ concentrations between resting and recovery conditions. During exercise, H₂ concentrations decreased three to six-fold in comparison to resting and recovery levels and differed among intakes (ANOVA;P < 0.05). The H₂ on concentrations were almost continuously lower with P than with F and S. The H₂ concentrations were significantly higher during running than during cycling. During exercise, we found that CHO overflow could be compared among intakes and between exercise types by using the HBT, provided the influence of other factors on H₂ excretion — ventilation and intestinal blood flow — was similar for each condition.