Barbara Błońska-Fajfrowska

Feasibility of a breath test with a substrate of natural 13C-abundance and isotope-selective non-dispersive infrared spectrometry: A preliminary study

Background and Aims:  Isotope‐selective non‐dispersive infrared spectrometry (NDIRS) is a cheaper alternative to isotope ratio mass spectrometry (IRMS). We checked on the efficiency of NDIRS to perform a breath test with naturally 13C‐enriched maize starch.

How reproducible is cutaneous electrogastrography? An in-depth evidence-based study1

Abstract  Aim:  To check on reproducibility of parameters of the cutaneous electrogastrogram registered at a close or a distant time span.

13C-methacetin breath test reproducibility study reveals persistent CYP1A2 stimulation on repeat examinations

AIM To find the most reproducible quantitative parameter of a standard (13)C-methacetin breath test ((13)C-MBT). METHODS Twenty healthy volunteers (10 female, 10 male) underwent the (13)C-MBT after intake of 75 mg (13)C-methacetin p.o. on three occasions. Short- and medium-term reproducibility was assessed with paired examinations taken at an interval of 2 and 18 d (medians), respectively. RESULTS The reproducibility of the 1-h cumulative (13)C recovery (AUC(0-60)), characterized by a coefficient of variation of 10%, appeared to be considerably better than the reproducibility of the maximum momentary (13)C recovery or the time of reaching it. Remarkably, as opposed to the short gap between consecutive examinations, the capacity of the liver to handle (13)C-methacetin increased slightly but statistically significantly when a repeat dose was administered after two to three weeks. Regarding the AUC(0-60), the magnitude of this fixed bias amounted to 7.5%. Neither the time gap between the repeat examinations nor the gender of the subjects affected the (13)C-MBT reproducibility. CONCLUSION (13)C-MBT is most reproducibly quantified by the cumulative (13)C recovery, but the exactitude thereof may be modestly affected by persistent stimulation of CYP1A2 on repeat examinations.

Interference of acute cigarette smoking with [13C]methacetin breath test

It is essential to establish whether and how environmental factors affect the reliability of [13C]methacetin breath test (13C-MBT). In 12 healthy volunteers (smokers), a standard 13C-MBT with 75 mg [13C]methacetin was performed twice in random order: on a control day without smoking and on another day with smoking two cigarettes antecedently. A considerable flattening of the curve of the momentary 13C recovery within the expiratory air was observed when the 13C-MBT was performed after smoking. The maximum of the momentary 13C recovery, D max, decreased from 37.20±2.58 to 25.39±2.29% dose/h (p=0.00052). Moreover, the time to reach D max was prolonged after cigarette smoking (26.5±3.1 vs. 16.5±1.9 min, p=0.0199). The curve of the cumulative 13C recovery on the cigarette smoking day appeared to be shifted downwards, and statistically significant differences relative to the control situation were found between the 24th and 75th minute following [13C]methacetin administration. Smoking cigarettes immediately prior to the 13C-MBT diminishes the ability of the liver to handle methacetin, and hence a possibility of such an interaction should be excluded in order to interpret the results of the test correctly.

Exact profiles of 13CO2 recovery in breath air after per oral administration of [13C]methacetin in two groups of different ages

The aim of this study is to determine if age is a factor influencing the results of a [13C]methacetin breath test (13C-MBT). Two groups of healthy volunteers, each comprising six men and six women, but differing in average age (Y=young, 25.1±0.6 years, MA=middle-aged;, 46.0±2.1 years) orally took 75 mg [13C]methacetin. Samples of expiratory air for 13CO2 measurement were collected up to 48 h after intake of the substrate. A maximum momentary 13CO2 breath exhalation of 37.0±2.6%dose/h was observed at 18 min (median, range: 9–30 min) in the young subjects and of 38.4±2.5%dose/h at 18 min (median, range: 12–30 min) in the middle-age volunteers. The cumulative 13C elimination in expiratory air was statistically significantly higher in the MA compared with the Y group as from 75 min up to 180 min, indicating a greater microsomal metabolic efficiency of the liver in the middle-aged healthy subjects. Gender, use of hormonal contraception, cigarette smoking, or body mass index did not modify the age-related effect on the cumulative 13C elimination in breath air. The study results imply a necessity of composing control groups well matched with regard to the age structure for a proper interpretation of clinical 13C-MBT results.

Taste and appetite disorders of chronic hepatitis C patients.

Objective Decreased appetite is one of the main factors that influences quality of life of patients with chronic liver diseases. The reason for appetite disorders remains unclear but taste perturbations are one of the postulated causes. The potential role of taste alterations and, connected to these, appetite disorders in chronic hepatitis C (CHC) patients are poorly investigated. The aim of this study was to evaluate potential taste alterations (dysgeusia) including all five tastes (sweet, salty, bitter, sour and umami) in CHC patients. Methods Forty CHC patients (16 men and 24 women) infected with genotype 1 hepatitis C virus participated in this study. All the patients had a compensated liver disease and were being treated with any agents. One hundred and ten healthy volunteers were matched to the patients by age and sex. The study included gustatory tests (taste recognition threshold, taste intensity with hedonic perception) and analysis of the pleasure derived from eating. Results In CHC patients, the recognition threshold of umami taste was increased (P<0.01) and the intensity of sweet taste perception was higher (P<0.05). The hedonic response did not differ between the groups. A significant increase in declared pleasure derived from eating (P<0.001 to P<0.05) was also observed. Some differences in case of the patients with more advanced disease were also found. Conclusion Alterations in taste, especially umami and sweet taste disorders, may alter real food perception and lead to a reduction in food intake in some CHC patients.

Effect of single-dose administration of recombinant interferon-alpha2b on gastric myoelectrical activity in patients with chronic hepatitis C.

BackgroundUpper abdominal complaints during interferon therapy may result from impaired gastric motility and/or evacuatory function. We examined the effect of acute administration of interferon on gastric myoelectrical activity (GMA) with the use of surface electrogastrography.MethodsThe study population comprised 25 patients with chronic hepatitis C. All of them were naïve to interferon. On 2 days, after a 25-min basal GMA registration, in group A (5 men, 7 women, aged 44.3 ± 2.8 years) placebo or 5 million i.u. recombinant interferon alpha-2b (IFNA) was administered s.c. and the GMA was recorded in the interdigestive state for two periods (2 h and 4 h), separated by a 15-min break. In group B (7 men, 6 women, aged 44.7 ± 3.9 years) placebo or 5 million i.u. IFNA was injected s.c. after the ingestion of a semiliquid test meal of 364 kcal. Subsequently, the postprandial GMA was recorded for two periods (2 h and 4 h), separated by a 15-min break.ResultsA typical flu-like syndrome was observed in 91.7% of patients in group A, and in 92.3% of patients in group B, thus providing evidence of the pharmacodynamic efficiency of the IFNA administration. In the fasted state, IFNA brought about a negligible increase in the rhythmicity and power of the gastric slow waves. IFNA did not elicit any statistically significant effect on gastric slow-wave activity postprandially.ConclusionsAcute administration of interferon does not involve any deterioration of GMA that could be linked to the previously reported upper abdominal symptoms in patients undergoing treatment with this drug.

Unreliability of Breath Methane as a Candidate Indicator of Functional Bowel Disorders

BACKGROUND/AIMS The aim of this study was to examine the reproducibility of methane and hydrogen in exhaled air breath after a per-oral load of lactulose. METHODS Methane was present in the exhaled breath of 21 of 50 healthy subjects recruited by advertisement. Three methane breath tests were performed in 12 women (aged 23.6+/-0.5 years, mean+/-SEM) after they consumed 10 g of lactulose dissolved in 300 ml of water. Short- and medium-term reproducibilities were assessed by paired examinations taken 3 and 17 days (median) apart, respectively. RESULTS High values of coefficients of variation for paired examinations (CV(p)) indicated a poor short-term reproducibility of parameters characterizing either the methane or hydrogen excretion in breath air: CV(p) values of the maximum net increments over baseline in methane (max CH(4_net)), and in hydrogen (max H(2_net)), were 34% and 41%, respectively. Moreover, the reproducibility consistently deteriorated with increasing time gap between repeat measurements (CV(p): 60% for max CH(4_net) and 64% for max H(2_net)). CONCLUSIONS The low reproducibility of parameters characterizing quantitative methane breath excretion suggests that caution is necessary when judging the clinical usefulness of the methane breath test after a per-oral lactulose load for the purpose of diagnosing and classifying functional bowel disorders.

High-resolution Manometry in Patients with Gastroesophageal Reflux Disease Before and After Fundoplication.

Background/Aims The study aimed to determine pre- and post-fundoplication esophagogastric junction (EGJ) pressure and esophageal peristalsis by high-resolution manometry (HRM) in patients with gastroesophageal reflux disease (GERD). Methods Pre-operative and post-operative HRM data from 25 patients with GERD were analyzed using ManoView version 2.0.1. with updated software for Chicago classification and pressure topography. The study involved swallowing water boluses of 10 mL in the upright position. Results Significant increase of mean basal EGJ pressure and minimal basal EGJ pressure was found in post-operative as compared with preoperative patients (P < 0.05 and P < 0.001, respectively). Integrated relaxation pressure (IRP) reached higher values in post-operative patients than in pre-operative patients (P < 0.001). Intra-bolus pressure (IBP) was significantly higher (P < 0.05) and contractile front velocity (CFV) was slower (P < 0.01) in post-operative patients than in pre-operative patients. Moreover significant increase of distal contractile integral (DCI) was found in post-operative patients (P < 0.05). Hiatal hernia was detected by HRM in 11 pre-operative patients. Fifteen out of 25 post-operative patients complained of dysphagia. Conclusions Fundoplication restores the antireflux barrier by reinforcing EGJ basal pressures, repairing hiatal hernias, and enhances peristaltic function of the esophagus by increasing DCI. However slight IRP elevation found in post-fundoplication patients may result in bolus pressurization and motility disorders.

Alterations in taste perception as a result of hyperbaric oxygen therapy.

The present study evaluates the effect of hyperbaric oxygen therapy on taste sensitivity, hedonic perception of taste, and food preferences. The studied groups included 197 people in total (79 in the study group; 118 in the control group). All patients from the study group were treated with hyperbaric oxygen therapy due to chronic non-healing wounds. The control group consisted of healthy people, who did not receive hyperbaric oxygen therapy. The taste intensity, recognition thresholds, and hedonic perception were examined using gustatory tests. The aqueous solutions of sucrose for sweet, sodium chloride for salty, citric acid for sour, quinine hydrochloride for bitter, and monosodium glutamate for umami taste were used. The participants fulfilled the questionnaire to examine pleasure derived from eating certain types of dishes. Gustatory tests and analyses of the pleasure derived from eating in the study group were carried out before the first exposure to hyperbaric oxygen and then at the end of therapy, after at least 25 sessions of treatment. In the control group, examination of perception of taste sensations was conducted only once. The results of comparing patients with non-healing wounds with healthy people are characterized by reduced taste sensitivity. After participation in hyperbaric oxygen therapy, the improvement in perception of taste sensations and changes in hedonic evaluation have occurred among patients with non-healing wounds. In terms of food preference, a decreased desire for eating sweet desserts, chocolate, and crisps was observed in those patients who received hyperbaric oxygen therapy.