Instrumentation and Measurement Strategy for the NOAA SENEX Aircraft Campaign as Part of the Southeast Atmosphere Study 2013.

Natural emissions of ozone-and-aerosol-precursor gases such as isoprene and monoterpenes are high in the southeast of the US. In addition, anthropogenic emissions are significant in the Southeast US and summertime photochemistry is rapid. The NOAA-led SENEX (Southeast Nexus) aircraft campaign was one of the major components of the Southeast Atmosphere Study (SAS) and was focused on studying the interactions between biogenic and anthropogenic emissions to form secondary pollutants. During SENEX, the NOAA WP-3D aircraft conducted 20 research flights between 27 May and 10 July 2013 based out of Smyrna, TN. Here we describe the experimental approach, the science goals and early results of the NOAA SENEX campaign. The aircraft, its capabilities and standard measurements are described. The instrument payload is summarized including detection limits, accuracy, precision and time resolutions for all gas-and-aerosol phase instruments. The inter-comparisons of compounds measured with multiple instruments on the NOAA WP-3D are presented and were all within the stated uncertainties, except two of the three NO2 measurements. The SENEX flights included day- and nighttime flights in the Southeast as well as flights over areas with intense shale gas extraction (Marcellus, Fayetteville and Haynesville shale). We present one example flight on 16 June 2013, which was a daytime flight over the Atlanta region, where several crosswind transects of plumes from the city and nearby point sources, such as power plants, paper mills and landfills, were flown. The area around Atlanta has large biogenic isoprene emissions, which provided an excellent case for studying the interactions between biogenic and anthropogenic emissions. In this example flight, chemistry in and outside the Atlanta plumes was observed for several hours after emission. The analysis of this flight showcases the strategies implemented to answer some of the main SENEX science questions.

Release of gas-phase halogens by photolytic generation of OH in frozen halide-nitrate solutions: an active halogen formation mechanism?

To better define the mechanisms by which condensed-phase halides may be oxidized to form gas-phase halogens under polar conditions, experiments have been conducted whereby frozen solutions containing chloride (1 M), bromide (1.6 x 10(-3) to 5 x 10(-2) M), iodide (<1 x 10(-5) M), and nitrate (0.01 to 1 M) have been illuminated by ultraviolet light in a continually flushed cell. Gas-phase products are quantified using chemical ionization mass spectrometry, and experiments were conducted at both 248 and 263 K. Br(2) was the dominant product, along with smaller yields of IBr and trace BrCl and I(2). The Br(2) yields were largely independent of the Br(-)/Cl(-) ratio of the frozen solution, down to seawater composition. However, the yields of halogens were strongly dependent on the levels of NO(3)(-) and acidity in solution, consistent with a mechanism whereby NO(3)(-) photolysis yields OH that oxidizes the condensed-phase halides. In support, we observed the formation of gas-phase NO(2), formed simultaneously with OH. Gas-phase HONO was also observed, suggesting that halide oxidation by HONO in the condensed phase may also occur to some degree. By measuring the production rate of condensed-phase OH, using benzoic acid as a radical trap, we determine that the molar yield of Br(2) formation relative to OH generation is 0.6, consistent with each OH being involved in halide oxidation. These studies suggest that gas-phase halogen formation should occur simultaneously with NO(x) release from frozen sea ice and snow surfaces that contain sufficient halides and deposited nitrate.

Daily treatment with esomeprazole is superior to that taken on-demand for maintenance of healed erosive oesophagitis.

BACKGROUND: On-demand therapy with esomeprazole is effective for long-term treatment of non-erosive gastro-oesophageal reflux disease, but it has not been evaluated in erosive gastro-oesophageal reflux disease. AIMS: To compare endoscopic and symptomatic remission over a 6-month period when patients with healed erosive gastro-oesophageal reflux disease are treated with esomeprazole 20 mg, either once daily or on-demand. METHODS: Patients with verified erosive reflux oesophagitis of Los Angeles grades A-D were enrolled. Following 4-8 weeks treatment with esomeprazole 40 mg daily, those who were endoscopically healed and had symptom control during the last week were randomized to maintenance therapy for 6 months with esomeprazole 20 mg, taken either once daily or on-demand. RESULTS: Of 539 enrolled patients, 494 (91%) were healed at 8 weeks and 477 were randomized to maintenance therapy with esomeprazole 20 mg, 243 once daily and 234 on-demand. After once daily treatment, 81% of patients were still in remission at 6 months, compared with only 58% who took on-demand treatment (P < 0.0001). A difference in remission was found irrespective of baseline grade of oesophagitis, but it was more pronounced for the more severe grades. There was no difference in overall symptomatic remission between the two treatments, although heartburn was significantly more prevalent in the on-demand group. CONCLUSIONS: Once daily esomeprazole 20 mg was better than that taken on-demand for maintaining healed erosive oesophagitis, regardless of baseline Los Angeles grade.

Long-term effects of eradication of Helicobacter pylori on relapse and histology in gastric ulcer patients: a two-year follow-up study.

BACKGROUND: The main purpose of this study was to compare omeprazole (ome) plus two antibiotics (OMC) with omeprazole plus placebo (OP) with regard to gastric ulcer relapse for a period of 2 years in patients who were Helicobacter pylori-positive at inclusion. METHODS: Using double-blind randomization 125 patients with gastric ulcer were treated with either OMC (ome 20 mg b.i.d., metronidazole 400 mg b.i.d., clarithromycin 250 mg b.i.d.) (n = 64) or OP (ome 20 mg and placebo) (n = 61) for 1 week, followed by ome 20-40 mg o.d. until healing was confirmed endoscopically after 4, 8 or 12 weeks. Endoscopy and H. pylori diagnostics using culture, histology and serology were performed 6, 12 and 24 months after treatment or at symptomatic relapse. At inclusion, 35% of the OMC group and 38% of the OP group were taking non-steroidal anti-inflammatory drugs (NSAIDs). Nine percent (11/125) of the ulcers were malignant. RESULTS: The prevalence of H. pylori was 82% and the eradication rate 88% in the OMC group and 3% in the OP group. More than 90% of the ulcers were healed after 12 weeks. After 2 years, 76% of patients in the OMC group were in remission compared with 28% in the OP group (ITT) (P < 0.001). Sixty percent of patients in the OMC group that continued to take NSAIDs were in remission after 2 years compared with none in the OP group. Atrophy but not intestinal metaplasia decreased after treatment. CONCLUSIONS: Gastric ulcers are mainly caused by H. pylori, and relapse is effectively prevented by H. pylori eradication, even in patients on NSAIDs.

Meal size, satiety and cholecystokinin in gastrectomized humans.

A wealth of data supports the idea that the stomach and cholecystokinin octapeptide (CCK-8) normally play important roles in meal size and satiety. We studied long-term gastrectomized humans to further evaluate this possibility. Ten humans, who were gastrectomized 8 (3-12) years earlier, and eight controls ate a meal from a plate placed on a scale connected to a computer and estimated their satiety every minute using a computerized rating scale. Blood levels of CCK-8 were measured before and after the meal. There was no difference between the groups in the amount of food consumed or in the perception of satiety during the meal. Gastrectomized humans had higher blood levels of CCK-8 than controls before the meal; the levels increased after the meal in the controls but not in the gastrectomized subjects. It is suggested that although the stomach and CCK-8 normally are involved in the control of meal size and satiety, their roles are dispensable.

Bovine anti-Helicobacter pylori antibodies for oral immunotherapy.

BACKGROUND: Passive immunization with orally administered antibodies against specific pathogens has previously been successfully used therapeutically in both animal and human studies. We employed a similar strategy for experimental treatment of mice infected with the gastric pathogen Helicobacter pylori. METHODS: An anti-H. pylori bovine colostral hyperimmune immunoglobulin preparation (BIC) was generated and its efficacy was tested in different in vitro experiments, such as binding to the Lewis(b) blood group antigen, inhibition of adherence of H. pylori to human gastric mucosa tissue sections in situ and in a haemagglutination assay. The BIC preparation was also given in the drinking water to H. pylori-infected mice. RESULTS: An inhibition of 95% of the binding of H. pylori to Lewis(b) glycoconjugate was observed in vitro. Furthermore, a blocking activity of almost 90% was observed when the BIC was preincubated with H. pylori bacteria. Finally, the BIC preparation inhibited the haemagglutination of H. pylori and human red blood cells. Seven of 40 (17.5%) mice remained infected in the treatment group as compared with 25 of 45 (55.5%) in the control group. Hence, the cure rate was 66%, P = < 0.001. The mean number of colonies in the antibody-treated mice where eradication was not successful was also reduced (P < 0.05). In trials using FVB/N transgenic Lewis(b) expressing mice, a cure rate of 50%-66% was observed. CONCLUSION: Bovine colostral antibodies against H. pylori can be generated in high titres, inhibit binding in vitro and can eradicate or reduce the number of bacteria in infected mice.

A Swedish study of chemoradiation in squamous cell carcinoma of the esophagus.

This multicenter study describes the development of a chemoradiation protocol for the treatment of non-metastatic squamous cell carcinoma of the esophagus. Eighty patients were treated with three courses of chemotherapy (cisplatinum and 5-fluorouracil) with concomitant radiotherapy (40 Gy) during the last two courses of chemotherapy. Esophagectomy was performed, when feasible. If no operation was performed, patients were planned to receive a target dose of 64 Gy. Toxicity was mainly attributable to hematological impairment and led to two adjustments of the treatment protocol (addition of filgrastim and lowering of the 5-fluorouracil dose). These changes made it possible to administer the planned treatment in a gradually higher proportion of patients (13/23 [57%] before changes of treatment compared with 30/36 [83%] after changes). Treatment-related mortality was 3.75% (3 patients, associated with leucopenic septicemia after chemotherapy). Fifty-four patients were resected. No per- or postoperative mortality was encountered. The complete response (pathological CR) rate in operated patients was 46% (27/59 patients) after chemoradiation. In the whole series the CR rate (including clinical CR for non-resected patients) was 44%. With a minimum follow-up of 37 months, the 3-year survival for the whole group was 31% compared with 57% for the CR patients. Total 5-year survival thus far (July 1999) is 26%.

Prospective randomised comparison of adjustable gastric banding and vertical banded gastroplasty for morbid obesity.

OBJECTIVE: To compare the clinical results of adjustable gastric banding and vertical banded gastroplasty for morbid obesity. DESIGN: Prospective randomised trial. SETTING: University hospital, Sweden. PATIENTS: 59 morbidly obese patients, listed for obesity surgery. INTERVENTIONS: Adjustable gastric banding (n = 29) or vertical banded gastroplasty (n = 30). MAIN OUTCOME MEASURES: Weight loss, complications, need for revisional surgery, reflux symptoms and the patient's own evaluation. RESULTS: Five years after surgery the mean (SEM) weight reduction for adjustable gastric banding was 43 (3.0) kg and for vertical banded gastroplasty 35 (4.8) kg. One patient in each group died of unrelated causes during follow-up and 3 and 2 patients, respectively, were lost to follow-up. One patient in the vertical banded group required reoperation for an anastomotic leak on the third postoperative day. A total of 3 patients in the adjustable group required reoperation and 11 in the vertical banded group. CONCLUSIONS: Adjustable gastric banding carries a smaller risk of reoperation than vertical banded gastroplasty and the weight reduction is in the same order of magnitude.

Effect of supplements with lactic acid bacteria and oligofructose on the intestinal microflora during administration of cefpodoxime proxetil.

Thirty healthy volunteers in three groups participated in a study of the effect on the intestinal microflora of oral supplementation with Bifidobacterium longum, Lactobacillus acidophilus and oligofructose, an indigestible oligosaccharide, during oral administration of cefpodoxime proxetil bd for 7 days. Those in group A also received an oral supplement with c.1011 cfu of B. longum BB 536 and L. acidophilus NCFB 1748 and 15 g oligofructose daily, those in group B received a supplement with oligofructose only and those in group C received placebo, for 21 days. In all three groups there was a marked decrease in aerobic microorganisms, involving mainly a rapid and almost complete disappearance of Escherichia coli (P: < 0.05) during antimicrobial administration and, thereafter, an overgrowth of enterococci (P: < 0.05). The number of intestinal yeasts also increased significantly (P: < 0.05) in groups A and B over the same period. There was a dramatic decrease in anaerobic microorganisms on day 4 of administration, mainly caused by loss of bifidobacteria (P: < 0.05) in all groups. The number of lactobacilli also decreased but was significantly higher in group A than in group C at the end of cefpodoxime proxetil administration. Clostridium difficile was found in only one person from group A, but six persons each in groups B and C. Of the bifidobacterial strains isolated from the faecal samples in group A, one was similar to the strain of B. longum administered, but most volunteers were colonized by several different strains of B. longum during the investigation period. The administered strain of L. acidophilus was recovered from six patients in group A.

Modes of adherence of Helicobacter pylori to gastric surface epithelium in gastroduodenal disease: a possible sequence of events leading to internalisation.

We have investigated various modes of adherence of Helicobacter pylori to the human gastric epithelium, using transmission electron microscopy, in biopsies from nine patients with peptic ulcer disease and from four patients with chronic active gastritis. H. pylori was demonstrated in abundance in all cases within the surface mucous layer. In all ulcer- and in one out of four gastritis patients H. pylori was shown in close proximity to the gastric epithelium, with concurrent alterations in the configuration of microvilli and the apical cytoplasmic region of gastric cells. Previously described modes of H. pylori adherence were confirmed, such as loose attachment with fibrillar-like strands, firm attachment with pedestal formation, invasion in the intercellular spaces, and invagination with "cup" formation. Moreover, in many cases a fusion between the bacterial outer layer and gastric cell membranes was evident. In four cases (31%; three with active and one with past ulcer disease) viable H. pylori was found in the cytoplasm of gastric mucous cells. Our results support the hypothesis that the different modes of adherence of H. pylori represent a stepwise, possibly sequential, process which in a significant number of cases leads to internalisation of the organism. The invariable occurrence of adhesion and more frequent internalisation of H. pylori in ulcer patients may suggest a link with the pathogenesis of peptic ulcer disease.

Curing Helicobacter pylori infection in patients with duodenal ulcer does not provoke gastroesophageal reflux disease.

BACKGROUND: It has been suggested that the incidence of gastroesophageal reflux disease (GERD) increases after successful eradication of Helicobacter pylori infection. We present data on development of GERD from a controlled study of H. pylori eradication in 165 duodenal ulcer patients. METHODS: Patients (mean age, 55 years; 102 men; current smokers; n = 74) were randomly assigned 2: 1 to receive omeprazole, 40 mg twice daily, in combination with either amoxicillin, 750 mg twice daily, or placebo. Endoscopy and dyspeptic symptoms, including heartburn, were assessed at inclusion and at 6, 12, and 24 months after treatment. In addition, symptoms were assessed at 18 months. Patients with erosive esophagitis or reflux symptoms requiring treatment at inclusion were not included in the study. RESULTS: Fifty-one of 145 (35%) evaluable patients developed heartburn, and 13 of 145 (9%) developed esophagitis during follow-up. The life-table analysis of the cumulated risk of developing heartburn showed that patients whose H. pylori infection was eradicated had a significantly lower risk for developing heartburn than those with persistent H. pylori infection. The groups did not show any difference in cumulative risk of developing esophagitis. CONCLUSION: Our data show that successful eradication of H. pylori infection does not increase the incidence of GERD in duodenal ulcer patients.

Comparative effects of omeprazole, amoxycillin plus metronidazole versus omeprazole, clarithromycin plus metronidazole on the oral, gastric and intestinal microflora in Helicobacter pylori-infected patients.

Fourteen patients with Helicobacter pylori infection were treated with 20 mg omeprazole, 1 g amoxycillin and 400 mg metronidazole bd for 7 days (OAM), and 16 patients were treated with 20 mg omeprazole, 250 mg clarithromycin and 400 mg metronidazole bd for 7 days (OCM). Saliva, gastric biopsies and faecal samples were collected before, during (day 7) and 4 weeks after treatment in order to analyse alterations of the normal microflora and to determine antimicrobial susceptibility. Both treatment regimens resulted in marked quantitative and qualitative alterations. A selection of resistant streptococcal strains were noticed in both treatment groups, most apparent in the OCM group where a shift from susceptible to resistant strains was recorded. In the OAM group, six patients had overgrowth of resistant enterobacteriaceae during treatment compared with none in the OCM group, in the gastric microflora. The MICs for Enterococcus spp. and Enterobacteriaceae in faeces increased significantly during treatment in both groups. Nine patients in the OAM group became intestinally colonized by yeasts during treatment. The total anaerobic microflora was strongly suppressed in both treatment groups, although most pronounced in the OCM group, where the frequency of clarithromycin-resistant bacteroides strains increased from 2 to 76% during treatment, and remained at 59% 4 weeks post-treatment. Even if the treatment outcome was better in the OCM group (100%) than in the OAM group (71%), the amoxycillin-based treatment might be preferable from an ecological point of view, since the qualitative alterations in terms of emergence and persistence of resistant strains seemed to be most pronounced in the clarithromycin-treated group.

The value of different detection methods of Helicobacter pylori during treatment.

It has been suggested that profound acid inhibition by proton pump inhibitors affects the accuracy of H. pylori detection. This report aims to evaluate H. pylori status during treatment with four different invasive detection methods and to investigate if histopathological alterations during treatment can be used as an early marker for H. pylori eradication. Twenty-eight H. pylori-positive patients were studied randomized into two treatment groups: 14 patients received omeprazole, 20 mg plus amoxicillin 1,000 mg b.i.d (OA), and 14 patients received omeprazole, 20 mg and placebo b.i.d (OP) for 14 days. Biopsies from antrum and corpus of the stomach were collected on days 0, 10 and 42. H. pylori status was based on rapid urease test, cultivation, histology, and polymerase chain reaction (PCR). The biopsies were also graded according to the Sidney classification. In the OP and the OA group, 17% (2/12) and 92% (12/13) of the patients were H. pylori negative when tested during treatment (day 10). Four weeks after treatment none of the patients (0%) in the OP group and 61% (8/13) in the OA group had their H. pylori infection eradicated. PCR was up to 34% more sensitive than the other tests to detect H. pylori during treatment. There was a decrease in histological inflammation and activity in the antrum already during treatment in the OA group, but the decrease did not discriminate for successful treatment. During treatment with omeprazole alone or in combination with amoxicillin, H. pylori detection is impaired regardless of the detection method used. However, PCR appears to be more sensitive than other tests. Early changes in the histological appearance of the gastric mucosa do not predict H. pylori treatment outcome.

Prolonged and profound acid inhibition is crucial in Helicobacter pylori treatment with a proton pump inhibitor combined with amoxicillin.

BACKGROUND: The aim was to investigate whether intragastric pH, meal-stimulated gastrin release, or demographic factors predict the outcome of Helicobacter pylori treatment. METHODS: Thirty-six patients with H. pylori infection were investigated with 24-h intragastric pH registration and meal-stimulated gastrin release before and during treatment with 20 mg omeprazole twice daily and 750 mg amoxicillin twice daily for 14 days. The influence of age, sex, smoking, ethnic origin, pH, and gastrin on treatment outcome were analysed with logistic regression. RESULTS: Eradication of H. pylori was achieved in 18 of 34 (53%) patients. The univariate analysis showed that age, ethnic origin, more than 84.2% of the time with pH above 4, and continuous periods longer than 156 min with intragastric pH above 6 were significantly associated with successful treatment of H. pylori. In the multivariate analysis only the two pH variables were found to be independent factors for predicting treatment outcome. CONCLUSION: The outcome of H. pylori treatment with omeprazole and amoxicillin may depend on several factors, such as age, ethnic origin, and a pronounced acid suppression. However, the only factor of independent importance in this study was prolonged and profound acid inhibition.

Comparison of the effect of lansoprazole and omeprazole on intragastric acidity and gastroesophageal reflux in patients with gastroesophageal reflux disease.

BACKGROUND: Lansoprazole (LAN) and omeprazole (OME) heal esophagitis effectively and to similar extents, but LAN has a faster effect on the relief of symptoms of gastroesophageal reflux. However, no strict comparison of the two proton pump inhibitors' effect on acid reflux and gastric acidity has been published. The aim of this study was to compare the effects of LAN and OME on gastroesophageal reflux with simultaneous measurements of gastric acidity in patients with established gastroesophageal reflux disease (GERD) and esophagitis. METHODS: Fourteen patients with endoscopically verified erosive esophagitis and with a pretreatment esophageal 24-h pH measurement showing acid reflux to the esophagus participated in the study. This was a double-blind, randomized study with crossover design. Before (day 0) and on the last day (day 5) of each treatment period with encapsulated 30 mg LAN or 20 mg OME daily, 24-h intraesophageal and intragastric acidity were measured with antimony electrodes connected to an ambulatory pH recording system. RESULTS: Ten of 14 patients completed the study. There were no differences in intragastric or intraesophageal acidity or the number of reflux episodes on day 0 between the two treatments. Both LAN and OME treatments increased the median and nocturnal intragastric pH and decreased the 24-h area under the time curve for intragastric acidity significantly and to about the same extent (79% and 69% acid inhibition by LAN and OME, respectively) (NS). However, the percentage of time with pH below 4 in the esophagus was significantly less during LAN treatment (1.92% +/- 2.29; mean +/- standard deviation) than during OME treatment (4.76% +/- 2.88%) on day 5 (P = 0.002). There were also significantly fewer reflux episodes >5 min during treatment with LAN (1.00 +/- 1.33) than with OME (2.90 +/- 2.42) at the end of the treatment period (P = 0.031). CONCLUSIONS: In this study lansoprazole and omeprazole had a comparable effect on gastric acidity in patients with established GERD with esophagitis. However, 30 mg lansoprazole daily reduced the acidity in the oesophagus and the number of refluxes more effectively than 20 mg omeprazole daily. This might indicate that proton pump inhibitors affect the esophageal clearance and/or influence the lower esophageal sphincter differently.

Comparative effects of cefadroxil and phenoxymethylpenicillin on the normal oropharyngeal and intestinal microflora.

The ecological effects on the commensal microflora in saliva and stool samples were studied during administration of two commonly used antibiotics: cefadroxil 500 mg b.i.d. for 10 days and phenoxymethylpenicillin 1 g b.i.d. for 10 days. Twenty healthy volunteers participated in the study. In the oropharyngeal microflora the aerobic microflora was significantly suppressed during administration of cefadroxil while no significant changes were noticed in the anaerobic microflora. Administration of phenoxymethylpenicillin caused a strong decrease in the number of viridans streptococci and an overgrowth of Neisseria cocci. The total numbers of anaerobic oropharyngeal microorganisms were suppressed during phenoxymethylpenicillin administration. In the intestinal microflora the variation in numbers of aerobic and anaerobic microorganisms was minor in both groups. The microflora became normalised 2 weeks after withdrawal of the drugs. It was concluded that peroral administration of cefadroxil to healthy volunteers resulted in minor ecological disturbances in the oropharyngeal and intestinal microflora, which were in the same range as for phenoxymethylpenicillin.

Comparative effects of levofloxacin and ofloxacin on the normal oral and intestinal microflora.

The aim of the study was to study the ecological effects of levofloxacin, compared to that of ofloxacin, on the oral and intestinal human microflora. 10 healthy volunteers received levofloxacin (500 mg) and 10 subjects were given ofloxacin (400 mg) perorally, once daily for 7 days. Saliva and stool samples were obtained prior to drug administration, during administration (days 2, 4 and 7), and after withdrawal of the agents (days 9, 11, 14 and 21). The concentrations of levofloxacin and ofloxacin in the saliva and faecal samples, respectively, were assayed, and quantitative and qualitative microbiological analyses were performed. Oral administration of levofloxacin and ofloxacin led to low drug concentrations in the saliva, which corresponded with mild disturbances in the oral microflora. High drug levels were obtained in the intestinal tract, and both agents caused a selective reduction in the normal microflora, mainly directed towards aerobic Gram-negative bacteria. There was no significant difference between levofloxacin and ofloxacin, regarding ecological effects on the normal oral and intestinal microflora. From an ecological point of view, these agents acted favourably, since no major selection of resistant strains occurred in the normal microflora during administration.

Accurate detection of Helicobacter pylori infection with a simplified 13C urea breath test.

The urea breath test (UBT) has been shown to be a reliable non-invasive method for detection of H. pylori infection. There is widespread use of a test meal in the 13C UBT, but to what extent exclusion of the test meal actually influences the accuracy of the test has been poorly investigated. In addition, there is variability between test protocols in breath sampling frequency. In this evaluation, 91 patients with dyspeptic symptoms were investigated in an out-patient endoscopy ward, using a simplified 13C UBT without a test meal, and a single point breath evaluation after ingestion of 13C-labelled urea. Helicobacter pylori infection was diagnosed on upper endoscopy by histology and rapid urease tests on biopsies from the antrum and corpus mucosa of the stomach. Fifty-four percent of the patients had H. pylori infection. With the chosen cut-off level, the sensitivity and specificity of the 13C UBT were 92% and 95%, respectively. We conclude that this simplified 13C UBT is easy to perform and a very reliable test for detecting H. pylori infection, making it a suitable test in routine clinical work.

Adenocarcinoid of the liver arising within an area of hamartoma with predominant bile duct component.

Malignant transformation in bile duct hamartomas has been previously reported in very rare instances. Here, we describe a unique case of a neuroendocrine tumor of the liver arising within an area of unusually large hamartoma with predominant bile duct component, hitherto unreported and distinct from the conventional von Meyenburg complex. The tumor was apparently secreting gastrin and chromogranin, with associated gastrinoma syndrome over several years. The histologic picture was reminiscent of a moderately differentiated adenocarcinoid, with positive mucin staining in a signet ring pattern. Tumor cells showed positive staining for neuron-specific enolase, chromogranin A, gastrin, and serotonin. Staining for pancreatic hormone peptides was negative. Resection of the tumor was apparently curative, with complete resolution of the patient's symptoms.