Showing papers on "Breath test published in 2012"

A breath test for malignant mesothelioma using an electronic nose

Abstract: Malignant mesothelioma (MM) is a rare tumour which is difficult to diagnose in its early stages Earlier detection of MM could potentially improve survival Exhaled breath sampling of volatile organic compounds (VOCs) using a carbon polymer array (CPA) electronic nose recognises specific breath profiles characteristic of different diseases, and can distinguish between patients with lung cancer and controls With MM, the potential confounding effect of other asbestos-related diseases (ARDs) needs to be considered We hypothesised that as CPA electronic nose would distinguish patients with MM, patients with benign ARDs, and controls with high sensitivity and specificity 20 MM, 18 ARD and 42 control subjects participated in a cross-sectional, case-control study Breath samples were analysed using the Cyranose 320 (Smiths Detection, Pasadena, CA, USA), using canonical discriminant analysis and principal component reduction 10 MM subjects created the training set Smell prints from 10 new MM patients were distinguished from control subjects with an accuracy of 95% Patients with MM, ARDs and control subjects were correctly identified in 88% of cases Exhaled breath VOC profiling can accurately distinguish between patients with MM, ARDs and controls using a CPA electronic nose This could eventually translate into a screening tool for high-risk populations

Comparison of lactulose and glucose breath test for diagnosis of small intestinal bacterial overgrowth in patients with irritable bowel syndrome.

Abstract: Background and Aims: Validity of the lactulose breath test (LBT) to diagnose small intestinal bacterial overgrowth (SIBO) has been questioned Therefore, a study was planned to comp

Helicobacter pylori infection contributes to high risk of ischemic stroke: evidence from a meta-analysis

Abstract: Chronic infection of Helicobacter pylori (H. pylori) in ischemic stroke (IS) incidence has been previously studied in several publications; however, conflicting results have been reported. A meta-analysis was used to assess whether chronic infection of H. pylori was associated with risk of IS, and which of the following was more effective for predication of IS risk, antibody IgG of H. pylori (anti-H. pylori IgG), antibody IgG of cytotoxin-associated gene-A (anti-Cag A IgG) or the 13C-urea breath test. We searched the databases of Medline and Embase, and latest update was January 1, 2012. Case–control studies were considered to be eligible. The odds ratio (OR) and 95 % confidence interval (95 % CI) were calculated using the random-effect model. A total of 13 studies including 4,041 participants were included in this meta-analysis. Of these studies, ten, four and four studies were for anti-H. pylori IgG, anti-Cag A IgG and the 13C-urea breath test, respectively. Combined analysis indicated that positive anti-H. pylori IgG, anti-Cag A IgG and 13C-urea breath test were significantly associated with increased risk of IS, respectively, and positive anti-Cag A IgG was more effective for predication of IS risk [OR (95 % CI) = 1.60 (1.21–2.11), P heterogeneity = 0.001 for positive versus negative anti-H. pylori IgG; 2.33 (1.76–3.09), P heterogeneity = 0.71 for positive versus negative anti-Cag A IgG and 1.65 (1.11–2.47), P heterogeneity = 0.17 for positive versus negative 13C-urea breath test]. In addition, we found that positive anti-H. pylori IgG was closely associated with risk of IS caused by atherosclerosis and small artery disease, but not for cardioembolic IS. This meta-analysis indicated that chronic H. pylori infection was significantly associated with an increased risk of IS, especially for non-cardioembolic IS. Compared with anti-H. pylori IgG and the 13C-urea breath test, anti-Cag A IgG seemed more effective for prediction of risk of IS.

Evaluation of a Four‐drug, Three‐antibiotic, Nonbismuth–containing “Concomitant” Therapy as First‐line Helicobacter pylori Eradication Regimen in Greece

Abstract: Background: The eradication rates of Helicobacter pylori (H. pylori) with standard treatments are decreasing worldwide as in Greece. Studies with new antibiotic combinations are needed to find better methods of eradication. Therefore, the aim of this study was to evaluate efficacy and tolerability of a 10-day, four-drug, three-antibiotic, nonbismuth–containing concomitant regimen. Materials and Methods: This is a prospective, open-label, multicenter study that included 131 patients infected with H. pylori. All patients were diagnosed with peptic ulcer disease or nonulcer dyspepsia by endoscopy. H. pylori infection was established by at least two positive tests among rapid urease test, gastric histology, and 13C-urea breath test. For 10 days, all patients received esomeprazole 40 mg, amoxycillin 1000 mg, clarithromycin 500 mg, and metronidazole 500 mg, all b.d. eradication was assessed with 13C urea breath test 8 weeks after the start of treatment. Intention-to-treat and per-protocol eradication rates were determined. Results: One hundred and twenty-seven of the 131 patients completed the study. At intention-to-treat analysis, the eradication rate was 91.6% (95% confidence interval (CI), 85.5–95.7%). For the per-protocol analysis, the eradication rate was 94.5% (95% CI, 89–97.8%). Adverse events were noted in 42 of 131 (32.1%); drug compliance was excellent with 96.9% of the patients taking more than 90% of the prescribed medication. Conclusion: A 10-day concomitant regimen appears to be an effective, safe, and well-tolerated treatment option for first-line H. pylori eradication in Greece.

Delayed gastric emptying determined using the 13C–octanoic acid breath test in patients with systemic sclerosis

Abstract: Objective To determine the prevalence of delayed gastric emptying using the 13C–octanoic acid breath test in unselected patients with systemic sclerosis (SSc), to evaluate whether findings of the 13C–octanoic acid breath test are associated with clinical digestive manifestations, gastric mucosal abnormalities detected by gastroscopy, motor activity dysfunction detected by antroduodenal manometry, and esophageal motor impairment and extradigestive manifestations of SSc, and to develop a risk prediction score of gastric emptying in SSc. Methods Consecutive patients with SSc (n = 57) underwent the 13C–octanoic acid breath test. All of the patients with SSc completed a questionnaire on digestive symptoms, and a global symptom score (GSS) was calculated. Results The prevalence of delayed gastric emptying was 47.4% in patients with SSc. A marked correlation was observed between a GSS of digestive symptoms ≥5 and the presence of delayed gastric emptying (P < 0.00001). The sensitivity of a GSS ≥5 for predicting delayed gastric emptying was as high as 0.93, while the specificity was 0.73. Moreover, a GSS ≥5, mucosal gastric abnormalities, severe esophageal motor impairment, and interstitial lung disease were factors that were independently associated with the presence of delayed gastric emptying, and these variables were used to create a risk prediction score. The area under the receiver operating characteristic curve for the risk prediction score was 0.90; the sensitivity of this score for the prediction of delayed gastric emptying was 0.93, while the specificity was 0.77. Conclusion The results indicate that delayed gastric emptying occurs often in patients with SSc. Interestingly, using risk models with routine clinical characteristics, a simple risk prediction score can be calculated, allowing prediction of the occurrence of delayed gastric emptying in patients with SSc.

Meta-analysis: the diagnostic accuracy of lactose breath hydrogen or lactose tolerance tests for predicting the North European lactase polymorphism C/T-13910.

Abstract: Aliment Pharmacol Ther 2012; 35: 429–440 Summary Background The diagnostic accuracy of two indirect tests of lactose digestion, lactose breath hydrogen and lactose tolerance tests, have not been systematically reviewed for comparison with available publications on genotype. Aim To perform a meta-analysis of available studies that compares the north-European genetic polymorphism C/T-13910 with the lactose breath hydrogen and the lactose tolerance tests, to determine their ability to predict geno/phenotype relationships. We examine the effects of lactose loading dose, inclusion of children and latitudes of study centre on comparative outcome. Methods An electronic database of the literature as well as individual references in articles were searched with the theme of genetics of lactase and comparisons with breath or lactose tolerance tests were carried out. Random effect and fixed effect models were used for breath and lactose tolerance tests respectively, to report summary accuracy measures with 95% confidence intervals (CI). Results The search revealed 19 studies: 17 evaluated breath hydrogen, five lactose tolerance test (3/17 overlapped). Overall sensitivity was 0.88 (CI, 0.85–0.90), specificity was 0.85 (CI, 0.82–0.87) for breath test. Heterogeneity was explored by adjusting for studies including children, high or low dose lactose and to some extent by site of study. The lactose tolerance test showed sensitivity of 0.94 (0.9–0.97) and specificity of 0.90 (0.84–0.95) with a nonsignificant heterogeneity. Conclusion The diagnostic accuracy of both tests individually reflects expected geno/phenotypes when the populations are well defined.

Evaluation of small intestine bacterial overgrowth in patients with functional dyspepsia through H2 breath test

Abstract: CONTEXT: Functional dyspepsia is a condition in which symptoms are not related to organic underlying disease; its pathogenesis is not well known. The small intestinal bacterial overgrowth (SIBO) is characterized by the increase in the number and/or type of colonic bacteria in the upper gastrointestinal tract. The hypothesis of SIBO being associated to functional dyspepsia must be considered, since the impaired motility of the gastrointestinal tract is one of the main etiologic factors involved on both pathologies. OBJECTIVE: To determine if there is SIBO in patients with functional dyspepsia. METHODS: Case-control study, evaluating 34 patients: 23 functional dyspeptic and 11 non-dyspeptic (control group). Questionnaire applied based on Rome III criteria. The patients underwent H2-lactulose breath test, considered positive when: H2 peak exceeding 20 ppm, in relation to fasting, or two peaks exceeding 10 ppm sustained until 60 minutes. RESULTS: Of the 23 dyspeptic patients, 13 (56.5%) obtained positive results for SIBO trough the H2-lactulose breath test. On control group, SIBO was not observed. The association between the dyspeptic group and the control group regarding SIBO was statistically significant, with P = 0.0052. In the group of dyspeptic patients, 12 (52.2%) were using proton pump inhibitor; of these 9 (75%) were positive for SIBO. In the control group, none of the 11 patients used proton pump inhibitors and SIBO was not observed. The association of the dyspeptic group using proton pump inhibitor that were positive for SIBO and the control group was statistically significant, with P = 0.0011. CONCLUSION: It was found that, patients with functional dyspepsia presented SIBO, when they underwent to H2-lactulose breath test, compared to the non-dyspeptic. In addition, it was observed a higher prevalence of SIBO in dyspeptic patients that were using proton pump inhibitors, compared to control group.

Assessment of gastric motor function in childhood functional dyspepsia and obesity

Abstract: Background The aim was to compare gastric emptying rate and nutrient tolerance during a satiety drinking test in children with functional dyspepsia (FD) and obesity and to study the relationship between daily caloric intake and the satiety drinking test. Methods A total of 28 dyspeptic children (22 girls, mean age 12.5 ± 3.1 years) and 15 obese children (five girls, 13.3 ± 1.8 years) were studied. The patients underwent an octanoic acid gastric emptying breath test and a satiety drinking test. Prior to both tests, a dyspepsia questionnaire was filled out to calculate the mean calorie intake. Key Results The most prevalent dyspeptic symptoms were early satiety (96.4%), postprandial fullness (89.2%), and epigastric pain (78.6%), followed by nausea (50%). All dyspeptic and obese children (n = 43) started the satiety drinking test and 41 children completed the test until a score of 5 was reached. The maximum ingested volume in FD was significantly lower than in obesity or in age-matched healthy controls (252 ± 85 vs 479 ± 199 and 359 ± 29 mL respectively, both P < 0.05). As a group, dyspeptic children had significantly slower gastric emptying than obese children (89.7 ± 54.8 min vs 72.5 ± 26.0 min, P = 0.05). Daily calorie intake was significantly higher in obese children than that in dyspeptic children (2325 ± 469 vs 1503 ± 272 cal, P < 0.0001). The endpoint of the satiety drinking test was significantly correlated with body weight or BMI (both R = 0.41, P = 0.04), but not with daily calorie intake, gastric emptying rate or age. Conclusions & Inferences The satiety drinking test is a potentially useful non-invasive tool in the investigation of children with FD and obesity.

Current tuberculosis diagnostic tools & role of urease breath test

Abstract: Tuberculosis (TB) remains a significant public health issue worldwide especially in developing countries, where the disease is endemic, and effective TB diagnostic as well as treatment-monitoring tools are serious barriers to defeating the disease. Detection of pathogen-specific metabolic pathways offers a potential alternative to current methods, which focus on bacterial growth, bacterial nucleic acid amplification, or detection of host immune response to the pathogen. Metabolic pathway detection may provide rapid and effective new tools for TB that can improve TB diagnostics for children and HIV infected patients. Metabolic breath tests are attractive because these are safe, and provide an opportunity for rapid point of care diagnostics and tool for drug efficacy evaluation during clinical trials. Our group has developed a rabbit urease breath test model to evaluate the sensitivity and the specificity of urease based detection of Mycobacterium tuberculosis. TB infected rabbits were given stable isotopically labelled urea as the substrate. The urea tracer was metabolized to 13 C-CO 2 and detected in exhaled breaths using portable infrared spectrometers. The signal correlated with bacterial load both for primary diagnostics and treatment monitoring. Clinical trials are currently ongoing to evaluate the value of the test in clinical management settings. Urea breath testing may provide a useful diagnostic and biomarker assay for tuberculosis and treatment response.

Ileocecal valve dysfunction in small intestinal bacterial overgrowth: A pilot study

Abstract: Aim To explore whether patients with a defective ileocecal valve (ICV)/cecal distension reflex have small intestinal bacterial overgrowth. Methods Using a colonoscope, under conscious sedation, the ICV was intubated and the colonoscope was placed within the terminal ileum (TI). A manometry catheter with 4 pressure channels, spaced 1 cm apart, was passed through the biopsy channel of the colonoscope into the TI. The colonoscope was slowly withdrawn from the TI while the manometry catheter was advanced. The catheter was placed across the ICV so that at least one pressure port was within the TI, ICV and the cecum respectively. Pressures were continuously measured during air insufflation into the cecum, under direct endoscopic visualization, in 19 volunteers. Air was insufflated to a maximum of 40 mmHg to prevent barotrauma. All subjects underwent lactulose breath testing one month after the colonoscopy. The results of the breath tests were compared with the results of the pressures within the ICV during air insufflation. Results Nineteen subjects underwent colonoscopy with measurements of the ICV pressures after intubation of the ICV with a colonoscope. Initial baseline readings showed no statistical difference in the pressures of the TI and ICV, between subjects with positive lactulose breath tests and normal lactulose breath tests. The average peak ICV pressure during air insufflation into the cecum in subjects with normal lactulose breath tests was significantly higher than cecal pressures during air insufflation (49.33 ± 7.99 mmHg vs 16.40 ± 2.14 mmHg, P = 0.0011). The average percentage difference of the area under the pressure curve of the ICV from the cecum during air insufflations in subjects with normal lactulose breath tests was significantly higher (280.72% ± 43.29% vs 100% ± 0%, P = 0.0006). The average peak ICV pressure during air insufflation into the cecum in subjects with positive lactulose breath tests was not significantly different than cecal pressures during air insufflation 21.23 ± 3.52 mmHg vs 16.10 ± 3.39 mmHg. The average percentage difference of the area under the pressure curve of the ICV from the cecum during air insufflation was not significantly different 101.08% ± 7.96% vs 100% ± 0%. The total symptom score for subjects with normal lactulose breath tests and subjects with positive lactulose breath tests was not statistically different (13.30 ± 4.09 vs 24.14 ± 6.58). The ICV peak pressures during air insufflations were significantly higher in subjects with normal lactulose breath tests than in subjects with positive lactulose breath tests (P = 0.005). The average percent difference of the area under the pressure curve in the ICV from cecum was significantly higher in subjects with normal lactulose breath tests than in subjects with positive lactulose breath tests (P = 0.0012). Individuals with positive lactulose breath tests demonstrated symptom scores which were significantly higher for the following symptoms: not able to finish normal sized meal, feeling excessively full after meals, loss of appetite and bloating. Conclusion Compared to normal, subjects with a positive lactulose breath test have a defective ICV cecal distension reflex. These subjects also more commonly have higher symptom scores.

Improving diagnosis of adult-type hypolactasia in patients with abdominal complaints.

Abstract: Background: Adult-type hypolactasia is caused by genetic lactase non-persistence. It is the most common cause of lactose intolerance, which results in gastrointestinal symptoms after ingestion of dairy products. Currently, lactose intolerance is investigated by the hydrogen breath test (HBT), which is considered the preferred diagnostic test. Adult-type hypolactasia may also be diagnosed by genotyping. The single nucleotide polymorphism -13910C>T, which is located upstream of the lactase gene (LCT), is tightly associated with lactase persistence. Several other variants, mostly in non-European populations, can also lead to lactase persistence. This study investigated the accuracy of a modified, recently proposed algorithm which includes genotyping for the diagnosis of adult-type hypolactasia in a patient population with unexplained abdominal complaints. Methods: In 126 patients with unexplained abdominal symptoms or who were suspected to have adult-type hypolactasia, LCT genotyping by melting curve analysis on a LightCycler was performed. Those patients with CC (-13910) genotype (indicating loss of lactase expression) were directly referred to a dietician for a lactose-free diet. Those identified as CT(-13910) or TT(-13910) genotype underwent a HBT. Those who tested positive for hydrogen were also referred to a dietician for a lactose-free diet. The response to diet modification was recorded. Results: Genotype prevalences were: CC (-13910): 43 (34.1%); CT(-13910): 48 (38.1%); TT(-13910): 33 (26.2%); TG(-13915): 2 (1.6%). Eleven of 48 (23%) patients with CT(-13910)- genotype and 1/33 (3%) patients with TT(-13910)-genotype had a positive hydrogen breath test. They all improved after a lactose-free diet. Four of 43 (9%) patients with CC(-13910)-genotype still had symptoms after a lactose-free diet. Conclusions: The results show that lactase-genotype testing can be used as a first step to diagnose lactose intolerance in a patient population with unexplained abdominal complaints. It accurately identifies the group of patients sensitive to lactose, those who need further breath testing and those in whom adult-type hypolactasia can be excluded with high probability without performing a HBT. This algorithm would save hydrogen breath testing in more than 50% of the patients who present with unexplained abdominal symptoms.

Is there delayed gastric emptying in patients with multiple system atrophy? An analysis using the (13)C-acetate breath test.

Abstract: Autonomic failure is one of the criteria according to the second consensus statement for the diagnosis of multiple system atrophy (MSA). Gastrointestinal symptoms are frequent complaints in patients with MSA and may be associated with reduced gastrointestinal motility due to autonomic nervous system dysfunction. However, there are few reports on gastric emptying in patients with MSA. We investigated gastric emptying in 25 patients with MSA, 20 patients with sporadic adult-onset ataxia of unknown etiology (SAOA), and 20 healthy volunteers using the 13C-acetate breath test. Gastric emptying function is estimated by this test as the half-emptying time (HET) and peak time of the 13C-%-dose-excess curve (Tmax), with expirations collected for 4 h after a test meal and determination of 13CO2 content using an infrared (IR) spectrophotometer. The HET and Tmax of gastric emptying were significantly delayed in patients with MSA as compared to those in SAOA and controls (p < 0.01). The HET and Tmax were not significantly different between SAOA and controls. No correlation existed between the HET or Tmax and the duration or severity of the disease in MSA patients. These results suggested that gastric emptying was significantly delayed in patients with MSA, and the delay already appeared in the early stage of the disease. Delayed gastric emptying is one of the autonomic failures and may be a clinical marker of MSA.

Prediction of clopidogrel low responders by a rapid CYP2C19 activity test

Abstract: Aim: Clopidogrel, an essential drug for the prevention of stent thrombosis, is a prodrug activated by CYP enzyme family including CYP2C19. It is known that activity-defective polymorphisms of CYP2C19 (CYP2C19*2 and*3) are associated with reduced clopidogrel efficacy and poor prognosis. Recently, the 13C-pantoprazole breath test is developed to evaluate the CYP2C19 activity. The aim of this study is to evaluated the efficiency of the CYP2C19 activity test as a predictor of antiplatelet effect of clopidogrelMethods: The CYP2C19 activity and the antiplatelet effect of clopidogrel were evaluated in 27 healthy volunteers. Change of the carbon isotope ratios (13CO2/12CO2) in expiration gas between before and after 13C-pantoprazole intake was evaluated as delta over baseline (DOB) ratio (‰). Results: DOB at 30 min was significantly lower in poor metabolizers (PMs) than extensive metabolizers (EMs) and intermediate metabolizers (IMs) (EM vs. PM, p=0.0108; IM vs. PM, p=0.016). The antiplatelet effect of clopidogrel was significantly different in three groups (inhibition of platelet aggregation: p=0.0148, P2Y12 reaction unit: p=0.0241). DOB at 30 min was correlated with the antiplatelet effect of clopidogrel. A cut-off value of DOB at 30 min below 1.0‰ predicted PMs with 96% specificity and 100% sensitivity.Conclusions: The 13C-pantoprazole breath test can detect CYP2C19 PMs and predict low responders to clopidogrel rapidly.

Effects of Emptying Function of Remaining Stomach on QOL in Postgastrectomy Patients

Abstract: Attention has recently focused on decreased quality of life (QOL) that occurs in postgastrectomy patients. We verified how gastric emptying function affected QOL. Subjects were 72 consecutive patients after gastrectomy for cancer, including 25 after distal gastrectomy (DG), 18 after proximal gastrectomy (PG), 16 after pylorus-preserving gastrectomy (PpG), and 13 after total gastrectomy (TG). Using the 13C breath test method, 13CO2 levels in breath were measured over 2 h, and T max was determined. Questionnaires (Japanese versions of the Short-Form 36 [SF-36] and Gastrointestinal Symptom Rating Scale [GSRS]) were used to analyze QOL and correlations between questionnaire results and T max. Mean T max (min) for each procedure was 15.4 for DG, 21.1 for PG, 41.3 for PpG, and 10.4 for TG. T max differed between procedures, but not between survey periods. SF-36 was not correlated with T max, whereas GSRS showed a difference in diarrhea and total score between procedures, but not between survey periods. In addition, GSRS correlated with T max for abdominal pain, indigestion, and total score. The total scores showed a significant symptom aggregation in patients with T max less than 21 min. Gastrointestinal symptoms in postgastrectomy patients were associated with the function of the remaining stomach. The 13C breath test is useful for objectively assessing such symptoms.

Diagnosis of adult-type hypolactasia/lactase persistence: genotyping of single nucleotide polymorphism (SNP C/T-13910) is not consistent with breath test in Colombian Caribbean population

Abstract: CONTEXT: Genotyping of single nucleotide polymorphism (SNP C/T-13910) located upstream of the lactase gene is used to determine adult-type hypolactasia/lactase persistence in North-European Caucasian subjects. The applicability of this polymorphism has been studied by comparing it with the standard diagnostic methods in different populations. OBJECTIVE: To compare the lactose hydrogen breath test with the genetic test in a sample of the Colombian Caribbean population. METHODS: Lactose hydrogen breath test and genotyping of SNP C/T-13910 were applied to 128 healthy individuals (mean age 35 ± 1). A positive lactose hydrogen breath test was indicative of hypolactasia. Genotyping was done using polymerase chain reaction/restriction fragment length polymorphism. The kappa index was used to establish agreement between the two methods. RESULTS: Seventy-six subjects (59%) were lactose-maldigesters (hypolactasia) and 52 subjects (41%) were lactose-digesters (lactase persistence). The frequencies of the CC, CT and TT genotypes were 80%, 20% and 0%, respectively. Genotyping had 97% sensitivity and 46% specificity. The kappa index = 0.473 indicates moderate agreement between the genotyping of SNP C/T-13910 and the lactose hydrogen breath test. CONCLUSION: The moderate agreement indicates that the genotyping of the SNP C/T-13910 is not applicable to determine adult-type hypolactasia/lactase persistence in the population participating in this study.

Influence of Different Proton Pump Inhibitors on Activity of Cytochrome P450 Assessed by [13C]-Aminopyrine Breath Test

Abstract: Aminopyrine is metabolized by cytochrome P450 (CYP) in the liver. The investigators evaluated influences of different PPIs on CYP activity as assessed by the [(13)C]-aminopyrine breath test ([(13)C]-ABT). Subjects were 15 healthy volunteers with different CYP2C19 status (5 rapid metabolizers [RMs], 5 intermediate metabolizers [IMs], and 5 poor metabolizers [PMs]). Breath samples were collected before and every 15 to 30 minutes for 3 hours after oral ingestion of [(13)C]-aminopyrine 100 mg on day 8 of each of the following regimens: control; omeprazole 20 mg and 80 mg, lansoprazole 30 mg, and rabeprazole 20 mg. Changes in carbon isotope ratios in carbon dioxide ((13)CO(2)/(12)CO(2)) in breath samples were measured by infrared spectrometry and expressed as delta-over-baseline (DOB) ratios (‰). Mean areas under the curve of DOB from 0 to 3 h (AUC(0-3h) of DOB) were significantly decreased by omeprazole 20 mg and lansoprazole 30 mg but not by rabeprazole 20 mg. Conversely, higher PPI dose (ie, omeprazole 80 mg) seemed to further decrease AUC(0-3h) of DOB in RMs but increased it in PMs. Omeprazole and lansoprazole at the standard doses inhibit CYP activity but rabeprazole does not, whereas high-dose omeprazole seems to induce CYPs.

Vehicle Interlocking System and Method Based on Detection of Analytes in Exhaled Breath

Abstract: A drug interlock for vehicles based on exhaled breath directed onto said SERS-active substrate, wherein a detected drug substance in exhaled breath of a subject locks said vehicle from use for at least a pre-determined time or a repeated exhaled breath test where no drugs are detected. A collecting surface has a Surface Enhanced Raman Spectroscopy (SERS)-active layer that comprises at least one SERS-active material. The collecting surface is arranged as an outer surface of a waveguide for contact with exhaled breath, such that at least traces of said at least one drug substance in said exhaled breath can contact said SERS-active layer for read-out of a Raman shift spectrum that is detected in-situ for said detecting the presence or determining the quantitative amount of said at least one drug substance from said exhaled breath.

Applicability of a short/rapid 13C-urea breath test for Helicobacter pylori: retrospective multicenter chart review study.

Abstract: Background: Carbon labeled urea breath tests usually entail a two point sampling with a 20 to 30-minute gap. Our aim was to evaluate the duration of time needed for diagnosing Helicobacter pylori by the BreathID ® System. Methods: This is a retrospective multicenter chart review study. Test location, date, delta over baseline, and duration of the entire test were recorded. Consecutively 13 C urea breath tests results were extracted from the files over a nine year period. Results: Of the 12,791 tests results, 35.1% were positively diagnosed and only 0.1% were inconclusive. A statistically significant difference in prevalence among the countries was found: Germany showing the lowest, 13.3%, and Israel the highest, 44.1%. Significant differences were found in time to diagnosis: a positive diagnosis had the shortest and an inconclusive result had the longest. Overall test duration averaged 15.1 minutes in Germany versus approximately 13 minutes in other countries. Diagnosis was achieved after approximately 9 minutes in Israel, Italy and Switzerland, but after 10 on average in the others. The mean delta over baseline value for a negative diagnosis was 1.03 ± 0.86, (range, 0.9 - 5), versus 20.2 ± 18.9, (range, 5.1 - 159.4) for a positive one. Conclusions: The BreathID ® System used in diagnosing Helicobacter pylori can safely shorten test duration on average of 10-13 minutes without any loss of sensitivity or specificity and with no test lasting more than 21 minutes.

Liver involvement in hereditary hemorrhagic telangiectasia: can breath test unmask impaired hepatic first-pass effect?

Abstract: Hepatic arteriovenous malformations (HAVMs) in hereditary hemorrhagic telangiectasia (HHT) have long been considered to have scarce clinical significance in most cases. Nevertheless, data are lacking regarding the influence of HAVMs on the liver first-pass effect on drugs in HHT patients. To gain insight into the effect of HAVMs on hepatic drug clearance by means of two specific 13C-labeled probes, namely the 13C-methacetin and 13C-aminopyrine, 46 HHT patients and 44-matched healthy controls were enrolled. The liver first-pass effect was studied by the 13C-based breath test using methacetin and aminopyrine. The methacetin breath test showed statistically significant reduced metabolism rates (p < 0.0001) in HHT when compared with controls, both in patients with and without CT-detectable HAVMs, and when expressed both as cumulative 13C-percentage dose per hour and as 13C-percentage peak after 15 min. In contrast, no significant difference was found between HHT and controls regarding aminopyrin metabolism rates. In HHT, 13C%-methacetin breath test values are significantly lower than those found in normal subjects, probably due to the effect of hepatic shunts. A reduced perfusion and an impaired hepatic metabolism might affect hepatic drug clearance in HHT. Therefore, an appropriate dosage adjustments should be considered when high-hepatic-metabolism drugs are administered to HHT patients.

Biomarkers of small intestinal mucosal damage induced by chemotherapy: an emerging role for the 13C sucrose breath test.

Abstract: Gastrointestinal mucosal toxicity is extremely common following cytotoxic therapies. The alimentary mucosa is particularly susceptible to injury and dysfunction, leading to many debilitating complications. Despite much research, there is currently no single noninvasive biomarker to detect gut injury. Several biomarkers have been investigated in the context of gastrointestinal diseases, which may prove useful in the oncology arena. Identification of a biomarker that is easy to obtain and measure and that accurately identifies mucosal damage would allow for improved patient diagnosis of toxicities and for personalized treatment regimens. In this review, we highlight the effectiveness of urine and breath tests as potential clinically effective biomarkers, with significant focus placed on the emerging role of the carbon-13 sucrose breath test (13C SBT). The 13C SBT provides a simple, noninvasive, and integrated measure of gut function. The 13C SBT also has the potential to monitor gut function in the setting of cytotoxic therapy-induced mucositis, or in the assessment of the efficacy of antimucositis agents.

Is (+)-[13C]-pantoprazole better than (±)-[ 13C]-pantoprazole for the breath test to evaluate CYP2C19 enzyme activity?

Abstract: Recently, we have shown that the (+)-[13C]-pantoprazole is more dependent on CYP2C19 metabolic status than (?)-[13C]-pantoprazole. In this study, we tested the hypothesis that (+)-[13C]-pantoprazole is a more sensitive and selective probe for evaluating CYP2C19 enzyme activity than the racemic mixture. (+)-[13C]-pantoprazole (95?mg) was administered orally in a sodium bicarbonate solution to healthy volunteers. Breath and plasma samples were collected before and up to 720?min after dosing. The 13CO2?in exhaled breath samples was measured by infrared spectrometry. Ratios of 13CO2/12CO2?after (+)-[13C]-pantoprazole relative to 13CO2/12CO2?at baseline were expressed as delta over baseline (DOB). (+)-[13C]-pantoprazole concentrations were measured by HPLC. Genomic DNA extracted from whole blood was genotyped for CYP2C19*2, *3 and *17 using Taqman assays. Statistically significant differences in the area under the plasma concentration time curve (AUCplasma(0-?)?(p < 0.001) and oral clearance (<0.01) of (+)-[13C]-pantoprazole as well as in the breath test indices (delta over baseline, DOB30; and area under the DOB versus time curve, AUCDOB(0?120)) (p < 0.01) were observed among poor, intermediate and extensive metabolizer of CYP2C19. DOB30?and AUCDOB(0?120)?adequately distinguished poor metabolizer from intermediate and extensive metabolizer of CYP2C19. Breath test indices significantly correlated with plasma elimination parameters of (+)-[13C]-pantoprazole (Pearson correlations:??0.68 to??0.73). Although relatively higher breath test indices were observed after administration of (+)-[13C]-pantoprazole (this study) than after (?)-[13C]-pantoprazole (previous study), the performance of the racemic and the enantiomer as marker of CYP2C19 activity remained similar. Our data confirm that the metabolism of (+)-[13C]-pantoprazole is highly dependent on CYP2C19 metabolic status, but the breath test derived from it is not superior to the racemic [13C]-pantoprazole in evaluating CYP2C19 activity in vivo. Thus, racemic [13C]-pantoprazole which is relatively easy to synthesize and more stable than (+)-[13C]-pantoprazole is adequate as a probe of this enzyme.

Comparison of abdominal bloating severity between Irritable Bowel Syndrome patients with high and low levels of breath hydrogen excretion in a lactulose breath test.

Abstract: Background: There is growing evidence that gut flora plays a role in the development of Irri- table Bowel Syndrome (IBS). Abdominal bloating is a common symptom in these patients and the severity of this symptom could be related to the variations in their fermentative profiles, obtained by measuring the levels of breath hydrogen excretion after lactulose ingestion. Aims: Our objective was to determine the difference in abdominal bloating severity between IBS patients with high vs low levels of breath hydrogen excretion after lactulose administration. Methods: Lactulose breath tests were carried out on IBS patients in our institution between July 2009 and August 2010. Patients were requested to fill out a validated questionnaire to assess the severity of their symptoms. Abdominal bloating severity score was compared among patients with high and low breath hydrogen levels. Results: A total of 234 patients were enrolled. There was a statistically significant difference in the abdominal bloating severity score between groups: 7.0 (5.7-8.0) vs 6.5 (5.0-7.5), p=0.001. The comparison among IBS patients with constipation (IBS-C) in both groups also showed a statistically significant difference: 7.5 (6.0-8.5) vs 5.8 (3.5-7.2), p=0.0051. Conclusions: Those patients with a low level of breath hydrogen excretion after lactulose inges- tion presented with significantly greater abdominal bloating than those with a high level of breath hydrogen excretion. © 2011 Asociacion Mexicana de Gastroenterologia. Published by Masson Doyma Mexico S.A. All rights reserved.

13C-phenylalanine breath test detects altered phenylalanine kinetics in schizophrenia patients.

Abstract: 13 C-phenylalanine breath test detects altered phenylalanine kinetics in schizophrenia patients

Does domperidone, a D2-antagonist alter gastric emptying rates and appetite sensations in healthy adults with high-fat meal? A block-randomised, single-blind placebo-controlled study.

Abstract: Accelerated gastric emptying (GE) may lead to reduced satiation, increased food intake and is associated with obesity and type 2 diabetes. Domperidone is a dopamine 2 (D2) receptor antagonist with claims of gastrointestinal tract pro-kinetic activity. In humans, domperidone is used as an anti-emetic and treatment for gastrointestinal bloating and discomfort. To determine the effect of acute domperidone administration on GE rate and appetite sensations in healthy adults. A single-blind block randomised placebo-controlled crossover study assessed 13 healthy adults. Subjects ingested 10 mg domperidone or placebo 30 min before a high-fat (HF) test meal. GE rate was determined using the 13CO2 octanoic acid breath test. Breath samples and subjective appetite ratings were collected in the fasted and during the 360 min postprandial period. Gastric emptying half-time was similar following placebo (254 ± 54 min) and 10 mg domperidone (236 ± 65 min). Domperidone did not change appetite sensations during the 360 min postprandial period (P > 0.05). In healthy adults, acute administration of 10 mg domperidone did not change GE or appetite sensations following a HF test meal (NCT01347814).

Estimation of Insulin Resistance in Mexican Adults by the [(13)C]Glucose Breath Test Corrected for Endogenous Total CO(2) Production.

Abstract: Objective. To evaluate the efficacy of the [ 13C]glucose breath test for measuring insulin resistance in Mexican adults with different glycemic states. Research Design and Methods. Fifty-eight adults underwent a [ 13C]glucose breath test with simultaneous measurement of total CO 2 production by indirect calorimetry, at baseline and 90 minutes after the ingestion of 15 g of dextrose and 25 mg of [ 13C]glucose. HOMA was used as a marker of insulin resistance. Results. We found an inverse correlation between HOMA and the breath test δ13CO 2 (‰), ( ). After adjusting for total CO 2 production, correlations between HOMA and fasting glucose were less strong but remained significant. An ROC curve was constructed using δ13CO 2 (‰) and HOMA values; the cut-off point was 9.99‰ δ13CO 2, corresponding to a sensitivity of 80.0 (95% CI: 51.9, 95.7) and a specificity of 67.4 (95% CI: 51.5, 80.9). Conclusions. The [ 13C]glucose breath test is a simple noninvasive procedure but was not sufficiently robust for an accurate diagnosis of insulin resistance. Our findings suggest that the test might be helpful in identifying individuals who are not IR, which in turn may contribute to improved diabetes prevention.