A modular and optimized single marker system for generating Trypanosoma brucei cell lines expressing T7 RNA polymerase and the tetracycline repressor.

Here, we present a simple modular extendable vector system for introducing the T7 RNA polymerase and tetracycline repressor genes into Trypanosoma brucei. This novel system exploits developments in our understanding of gene expression and genome organization to produce a streamlined plasmid optimized for high levels of expression of the introduced transgenes. We demonstrate the utility of this novel system in bloodstream and procyclic forms of Trypanosoma brucei, including the genome strain TREU927/4. We validate these cell lines using a variety of inducible experiments that recapture previously published lethal and non-lethal phenotypes. We further demonstrate the utility of the single marker (SmOx) TREU927/4 cell line for in vivo experiments in the tsetse fly and provide a set of plasmids that enable both whole-fly and salivary gland-specific inducible expression of transgenes.

Improvement of tissue-adhesive obliteration of bleeding gastric varices using adjuvant hypertonic glucose injection: a prospective randomized trial.

BACKGROUND AND STUDY AIMS: Rebleeding can occur after endoscopic injection of gastric varices with tissue adhesive. The aim of this study was to evaluate whether adjuvant hypertonic glucose solution injections enhance the effects of Histoacryl after successful initial variceal obliteration. PATIENTS AND METHODS: A total of 67 patients (37 men, 30 women; mean age +/- standard deviation [SD] 60 +/- 17 years) with initially successful Histoacryl obliteration of bleeding gastric varices were included in the study and randomly divided into two groups: a "combined" group of patients who had adjuvant injection of hypertonic glucose solutions in cases of residual gastric varices (F1 or less) and a "control" group of patients who did not receive such therapy. End points were either variceal recurrence/progression (F2 or more) requiring Histoacryl reinjection or rebleeding. RESULTS: Residual small varices were found in 56% of patients in the combined group and in 60% of patients in the control group. Adjuvant therapy was only performed in the combined group. During the follow-up period (mean duration +/- SD 37.9 +/- 18.5 months, range 19-56 months), two patients in the combined group showed gastric variceal progression, compared with nine patients showing progression in the control group, with two cases of rebleeding, both occurring in the control group. Two years after the first Histoacryl injection, the cumulative proportion of patients who did not have gastric variceal progression was significantly higher in the combined group than it was in the control group (92.8% vs. 71.4%, P = 0.029). There was no significant difference between the two groups with respect to their survival curves (P = 0.12). No marked immediate or delayed symptoms or complications were observed in the patients given hypertonic glucose injections. CONCLUSIONS: Adjuvant treatment with hypertonic glucose solution for residual small gastric varices is a safe and simple method. It helps reduce the recurrence or progression of gastric varices after tissue adhesive injections and can therefore reduce the risk of rebleeding.

Primary resistance to antibiotics and its clinical impact on the efficacy of Helicobacter pylori lansoprazole-based triple therapies.

AIM: To evaluate Helicobacter pylori primary resistance and its clinical impact on the efficacy of two lansoprazole-based eradication triple therapies. METHODS: H. pylori-positive patients (n=228) were randomized to receive one of the 1-week regimens: lansoprazole 30 mg, clarithromycin 500 mg and amoxicillin 1 g (LAC), or lansoprazole 30 mg, clarithromycin 500 mg and metronidazole 500 mg (LMC), each given twice daily. H. pylori status was assessed by 13C-urea breath test and culture at diagnosis and by 13C-urea breath test 6 weeks after therapy. Antibiotic susceptibility was determined by E-test (n=98). RESULTS: The eradication rates with per protocol/ intention-to-treat analyses were: LAC (n=95/114) 83%/69% and LMC (n=96/114) 85%/72%. Primary resistance was 11% for clarithromycin, 41% for metronidazole and 0% for amoxicillin. Eradication in metronidazole-susceptible/-resistant strains was 85%/82% in LAC and 83%/63% in LMC. Significantly lower cure rates were observed in clarithromycin-resistant patients treated with LAC (95% vs. 0%, P < 0.001) and LMC (86% vs. 0%, P < 0.001). CONCLUSIONS: One-week LAC and LMC are similarly effective therapies. Clarithromycin resistance significantly affected H. pylori eradication in both regimens.

Role of Helicobacter pylori in cirrhotic patients with dyspepsia: a 13C-urea breath test study.

The role of Helicobacter pylori in dyspeptic, cirrhotic patients remains unclear. This prospective outpatient study, conducted to assess the relationship of gastroduodenal disease and H. pylori as determined by the (13C) urea breath test, enrolled 109 consecutive cirrhotic patients with dyspepsia. All patients underwent upper-gastrointestinal endoscopy, which revealed respective prevalences of peptic ulcer, gastric ulcer, and duodenal ulcer of 41.3%, 23.9%, and 22.9%; H. pylori infection was found in 52.3%. The rate of peptic ulcer disease in the H. pylori-positive (45.6%) and -negative (36.5%) groups was not significantly different; neither was the prevalence of H. pylori in patients with or without portal hypertensive gastropathy and with or without esophageal varices. The relationship between peptic ulcer disease and H. pylori in dyspeptic patients with cirrhosis appears to be weak. Likewise, no significant relationship was evident between H. pylori and portal hypertensive gastropathy or esophageal varices. This organism may not be a major pathogenetic factor in gastroduodenal diseases in dyspeptic patients with cirrhosis.

The effect of jejunal meal feeding on gastroesophageal reflux.

BACKGROUND: Postprandial gastric distention is frequently associated with transient lower esophageal sphincter relaxation and gastroesophageal reflux (GER). Since the role of nutrient perfusion into the jejunum in inducing GER is not well understood, we studied the effect of jejunal feeding on GER through a percutaneous gastrojejunal tube in patients with and without reflux esophagitis. METHODS: Nine stroke patients with reflux esophagitis were fed through a percutaneous gastrojejunal tube with either a liquid meal (2 kcal/2 ml/min) or saline for 2 h randomly on 2 separate days. An esophageal pH probe was placed 5 cm above the gastroesophageal junction to detect acid reflux. Six stroke patients without esophagitis were enrolled as controls. RESULTS: In both the patients with esophagitis and the controls, esophageal acid exposure (15.3% (4.9%-28.2%) versus 2.7% (0.0%-10.8%), P=0.003; 5.9% (0.5%-6.7%) versus 0.0% (0.0%-1.5%), P = 0.01) and events of acid reflux (5 (1-16) versus 2 (0-8), P = 0.02; 12 (3-17) versus 1 (0-4), P = 0.02) were significantly greater during jejunal meal feeding than during saline infusion. Furthermore, in the reflux patients, but not in the controls, acid clearance time was also greater during jejunal meal feeding than during saline infusion (2.9 min (0.5-9.6 min) versus 0.7 min (0.0-4.3 min), P = 0.04). CONCLUSIONS: We therefore conclude that jejunal nutrient infusion without gastric distention can induce GER in both patients with reflux esophagitis and controls. This implies that GER induced by jejununal nutrients may in part explain the incapability of jejunal tube feeding to prevent gastropulmonary aspiration in patients at risk.

Felodipine does not increase the reflux episodes in patients with gastroesophageal reflux disease.

BACKGROUND/AIMS: Calcium channel blocking agents have been reported to increase the risk of gastroesophageal reflux. However, whether felodipine, a newer calcium channel blocker, increases reflux episodes and decreases esophageal acid clearance in patients with gastroesophageal reflux disease has never been studied. Therefore, the aim of this study was to evaluate whether felodipine increases the incidence of gastroesophageal reflux in patients with gastroesophageal reflux disorder. METHODOLOGY: Nine patients with gastroesophageal reflux disease, 6 men and 3 women, with a mean age of 62.6 +/- 14.4 years (range: 37-80 years) were studied. They received ambulatory esophageal pH monitoring for 45.7-48 hours (mean: 47.1 +/- 0.8 hours). Various pH parameters were evaluated during a similar interval of monitoring time before and after receiving 5 mg of felodipine. RESULTS: No significant difference was noted in any pH parameter by the Wilcoxon signed Ranks test, including reflux episodes (P = 0.552), reflux episodes longer than 5 min (P = 0.683), esophageal acid clearance (P = 0.663) and fraction time of pH < 4 (P = 0.752) before and after the use of felodipine. CONCLUSIONS: Felodipine does not increase reflux episodes or impair esophageal acid clearance in patients with gastroesophageal reflux disease.

Endoscopic treatment of bleeding gastric varices by N-butyl-2-cyanoacrylate (Histoacryl) injection: long-term efficacy and safety.

BACKGROUND: The long-term efficacy and safety of the endoscopic injection of N-butyl-2-cyanoacrylate (Histoacryl) were evaluated to define its role as the initial treatment for bleeding gastric varices. METHODS: Ninety patients with bleeding gastric varices underwent endoscopic injections of Histoacryl for hemostasis within a 6-year period. Histoacryl was injected intravariceally as a 1:1 mixture with Lipiodol. Among the 90 patients, 5 had active bleeding and 85 had recent bleeding. Most of the varices were large (F2 or F3, 85 cases). The most common locations were the fundus and the posterior wall of the proximal body (94.4%). After Histoacryl injection, patients were followed endoscopically with retreatment as necessary. RESULTS: The rate of hemostasis at 1 week was 94.4%. Recurrent bleeding occurred in 23.3% of the patients from 3 days to 16 months after the initial injection. Recurrent bleeding was stopped with reinjections of Histoacryl in 16.7% of the patients. The rate of definitive hemostasis was 93.3% (84 of 90). The treatment failure-related mortality rate was 2.2% (2 of 90). To date, 35 patients have died, mostly as a result of malignancy or liver failure, and 55 are still alive. The determining factor for long-term survival was the underlying disease leading to portal hypertension. There were few long-term complications except for Histoacryl cast extrusion-related mucosal defects. CONCLUSIONS: Endoscopic injection of Histoacryl is highly effective for the treatment of bleeding gastric varices, with rare complications both acutely and long term. This treatment modality is appropriate as the first choice for bleeding gastric varices.

Nasogastric lansoprazole is effective in suppressing gastric acid secretion in critically ill patients.

AIM: To evaluate the effect of nasogastric lansoprazole on acid suppression in critically ill patients. METHODS: Patients were eligible for the study if they had a nasogastric tube in place and had not received acid-suppressive agents for 3 days prior to enrolment into the study. Patients with active gastrointestinal bleeding or a baseline gastric pH > 4.0 were excluded. Patients served as their own controls during a 24 h lead-in period. Lansoprazole 30 mg was administered once daily with water through a nasogastric tube for 2 days. Intragastric pH was measured by continuous 24 h pH-metry for 3 days. RESULTS: Fifteen patients were enrolled into the study. The baseline median 24 h intragastric pH was 2.25 +/- 1.01, and increased to 6.70 +/- 0.82 (P= 0.001) after 2 days of lansoprazole. Mean percentage of time intragastric pH was > or = 4.0 was 25 +/- 13% at baseline, and increased to 84 +/- 14% (P=0. 001) after 2 days of lansoprazole. CONCLUSIONS: Nasogastric lansoprazole 30 mg daily is effective in suppressing gastric acid secretion in critically ill patients.

Correlation between Helicobacter pylori infection and gastrointestinal symptoms in pregnancy.

Nausea, vomiting, and other dyspeptic symptoms are common in pregnancy. This hospital-based, cross-sectional study was designed to determine the role of Helicobacter pylori infection in gastrointestinal (GI) symptoms during pregnancy. Standardized verbal scales were used to evaluate the frequency and severity of GI symptoms in 54 women whose pregnancies were in the first 16 gestational weeks. H. pylori infection was defined as a positive serum immunoglobulin G result on an immunochromatographic assay. The H. pylori seropositivity rate was higher in the pregnant women (69%) than in the general population (approximately 50%-55%), but seropositivity did not correlate with clinical symptoms. Moreover, no specific patterns of GI symptoms were uncovered in the H. pylori-infected patients. Maternal age, body weight, parity, gestational week, and educational level were not associated with H. pylori infection; neither were the prevalence and severity of GI symptoms.

Heterogeneous Helicobacter pylori isolates from H. pylori-infected couples in Taiwan.

Helicobacter pylori strain diversity was investigated in 55 H. pylori seropositive couples in Taiwan in biopsy samples from the antrum and corpus. Two DNA typing methods were used to characterize 90 isolates from 25 couples. In only 1 of the 25 couples was the same strain colonized from both partners. Comparison of isolates from 2 sites in each of 40 patients showed that 9 pairs were distinct but might be related. Peptic ulcer occurred in 77.8% of these 9 patients compared with 29% of 31 patients with the same predominant strain in 2 biopsies (P=.025). Random amplified polymorphic DNA and sequence analyses of 2 closely related isolates from 1 patient support the hypothesis that development of genetic diversity of H. pylori results from horizontal genetic exchange during long-term colonization of mixed bacterial populations.

The effect of intragastric acidity on Helicobacter pylori eradication with bismuth-metronidazole-amoxicillin.

BACKGROUND/AIMS: Adding an acid secretion inhibitor to anti-H. pylori regimens may be potentially valuable for enhancing the effectiveness of antimicrobials that exhibit markedly reduced activity at low pH. This study was conducted to evaluate intragastric acidity as a factor in H. pylori eradication with bismuth-based triple therapy. METHODOLOGY: Forty patients with duodenal ulcer and H. pylori infection were included. The patients were divided into 2 groups--normacid (n = 20) and hyperacid (n = 20)--based on the amount of time that 24-hour intragastric pH took to reach the level pH > or = 3. All patients received bismuth subsalicylate (600 mg 3 times daily), metronidazole (500 mg 3 times daily) and amoxicillin (500 mg 3 times daily) for 2 weeks. Then, all patients continued treatment with ranitidine (150 mg twice daily) for 8 weeks prior to the follow-up examination. Blood samples were collected before treatment for measurement of fasting gastrin and pepsinogen-I. RESULTS: Nine patients (45%) in the normacid group and 8 patients (40%) in the hyperacid group reported side effects. However, there were only 2 patients (10%) in each group who withdrew from the study due to intolerance of side-effects. There was no difference in the H. pylori eradication rate between the normacid and hyperacid groups (16/18, 88.9% vs. 15/18, 83.3%). CONCLUSIONS: Without co-administration of anti-secretary agents, intragastric acid is not a significant factor in the effectiveness of H. pylori eradication with bismuth-based triple therapy.

Interaction between Helicobacter pylori and non-steroidal anti-inflammatory drugs in peptic ulcer bleeding.

BACKGROUND: Helicobacter pylori and non-steroidal anti-inflammatory drugs (NSAIDs) are the two primary causes of peptic ulcer disease. How H. pylori and NSAIDs interact and influence the development of ulcer bleeding is still not clear. METHODS: A hospital-based, age- and sex-matched case-control study was conducted. Multivariate and stratified analyses were performed for further evaluation of the interaction between H. pylori and NSAIDs. RESULTS: Ninety-seven patients (52 gastric ulcers, 45 duodenal ulcers) and 97 non-ulcer controls were enrolled in the study. H. pylori and NSAIDs were both found to be independent risk factors for ulcer bleeding (H. pylori odds ratio, 2.22; 95% confidence interval (CI), 1.23-4.01; NSAIDs odds ratio, 4.57; 95% CI, 2.50-8.35). There was no synergistic effect. In contrast, a negative interaction was observed in the logistic regression and stratified analysis, although the difference was not significant (H. pylori adjusted odds ratio, 3.47; 95% CI, 1.73-6.95; NSAID adjusted odds ratio, 6.16; 95% CI, 3.14-12.09). CONCLUSION: H. pylori increases the risk of peptic ulcer bleeding but may play a protective role in NSAID users.

Electrogastrographic study of the effect of transcatheter arterial chemoembolization on gastric myoelectric activity.

BACKGROUND: Transcatheter arterial chemoembolization (TACE) of the hepatic artery is frequently used in the treatment of inoperable hepatocellular carcinoma (HCC). TACE causes not only effective tumor tissue necrosis in patients with hepatoma but also adverse effects on extrahepatic abdominal organs. There are no published reports on the effect of TACE on the gastric myoelectric activity. In this study, using cutaneous electrogastrography (EGG), we evaluated the effect of TACE on gastric myoelectric activity in patients with HCC. METHODS: A total of 27 patients (24 men and 3 women, aged 22 to 78 years) with hepatoma, admitted for TACE, were included in this study. Furthermore, 28 patients (24 men and 4 women, aged 26 to 75 years), admitted for diagnostic angiography of the liver, served as the control group. Cutaneous EGG was performed before and after TACE or angiography. RESULTS: In the TACE group there were significant changes in dominant frequency (DF) and percentages of DF in the defined normal range, bradygastric range, and tachygastric range on post-meal EGG. On fasting EGG, only the dominant frequency and percentages of DF in the bradygastric range changed significantly. However, there was no correlation between the occurrence of nausea/vomiting and the degree of change in the EGG variables, during both fasting and postprandial states. In the control group there were no significant differences in EGG variables before and after angiography. CONCLUSIONS: TACE can affect gastric myoelectric activity in HCC patients. Nevertheless, the relationship between changes in myoelectric activity and the occurrence of gastrointestinal symptoms needs further investigation.

Effect of cisapride on gastric dysrhythmia and emptying of indigestible solids in type-II diabetic patients.

BACKGROUND: Abnormal gastric slow-wave frequencies have been observed in diabetic gastroparesis. To evaluate the effect of cisapride on gastric dysrhythmia and emptying of indigestible solids, 20 type-II diabetic patients with symptoms suggestive of gastroparesis were enrolled in this study. METHODS: Cutaneous electrogastrography, gastric emptying of radiopaque markers, and evaluation of upper gastrointestinal symptoms were performed before and after administration of an 8-week course of cisapride. RESULTS: The fasting-state percentages of dominant frequency in normal and tachygastric ranges improved significantly after an 8-week course of cisapride treatment (P < 0.01 and P < 0.05, respectively). The post-meal percentages of dominant frequency in the tachygastric range also improved significantly after cisapride treatment (P < 0.05). The upper gastrointestinal symptoms score decreased significantly, and gastric emptying of radiopaque markers also increased significantly after 8 weeks of cisapride treatment (P < 0.01). CONCLUSIONS: In conclusion, this study showed that cisapride can improve gastric dysrhythmia during both fasting and post-meal phases in patients with diabetic gastroparesis. In addition, upper GI symptoms and gastric emptying of indigestible solids may also show significant improvement after 8 weeks of cisapride treatment.

Radionuclide imaging in primary amyloidosis with liver involvement.

A 74-year-old man with hepatomegaly, hyperglycemia, and proteinuria was diagnosed with primary amyloidosis with liver involvement, proven by biopsy. Abnormal distribution of tracer in the liver on Tc-99m phytate liver-spleen imaging and abnormal tracer uptake by the liver on Tc-99m pyrophosphate whole body imaging were observed. Scintigraphic imaging studies may be used noninvasively to evaluate the involvement of organs in patients with primary amyloidosis, reducing the risk of bleeding caused by biopsy.

Correlation between patterns of antral contractility and gastric emptying of radiopaque markers.

OBJECTIVES: Gastric clearance of radiopaque markers (ROMs) has been proposed as an easy and noninvasive technique for assessment of gastric emptying. This study was conducted to evaluate the role of antral obliterating contractions in gastric emptying of ROMs in healthy volunteers. METHODS: Fifteen healthy volunteers, 12 males and three females, aged 21-38 yr, were enrolled in this study. Simultaneous recording of scintigraphic solid phase gastric emptying, gastric clearance of ROMs, and gastric manometry were performed after an overnight fast. The data of scintigraphic solid phase gastric emptying were expressed by half-emptying time (t1/2). The ROMs remaining in the stomach were counted fluoroscopically 2.5 and 4.5 h after the test meal. The time for the appearance of antral obliterating contractions after the meal was calculated. RESULTS: Six subjects (40%) passed all 10 ROMs after 4.5 h of recording. Among these six subjects, five had antral obliterating contractions 190-251 min (mean 232.2 +/- 24.3 min) after the test meal. There was no significant difference in t1/2 between subjects with or without antral obliterating contractions within the 4.5 h of recording. CONCLUSIONS: There was a considerable intersubject variation in the time of first antral obliterating contraction after the test meal. In the healthy volunteers, all ROMs were passed when there was a postprandial antral obliterating contraction. However, some of the ROMs still passed from the stomach in the absence of antral obliterating contractions.

The incidence of reflux esophagitis among the Chinese.

OBJECTIVES: Very few epidemiological data on reflux esophagitis in Chinese are available in the literature. METHODS: To evaluate the incidence of reflux esophagitis, upper gastrointestinal endoscopies were performed on 2044 patients (male 1266, female 778; age range 16-82 yr) during a 6-month period. RESULTS: The overall incidence of reflux esophagitis was 5%, and most of the patients (86.3%) had a mild grade of esophagitis. Hiatal hernia was found in 44 patients (2.2%); those patients were significantly older than those without hiatal hernia (60.3 +/- 10.8 vs. 49.4 +/- 12.1 yr, p < 0.05). Patients with symptoms suggesting gastroesophageal reflux (acid regurgitation, heartburn, and belching) had higher incidence of esophagitis (22.9%, 22.5%, and 24.7%, respectively). The body mass index was significantly higher in patients with esophagitis than in those without esophagitis (25.7 +/- 3.1 vs. 24.0 +/- 3.6, p < 0.05). The male:female ratio for esophagitis was 5.6:1. No esophagitis was found in patients who were less than 21 yr old. However, there was a difference in age group distribution for the incidence of esophagitis. The habit of coffee or tea drinking does not contribute to the development of esophagitis. CONCLUSIONS: Based on the results of this study, the incidence of endoscopic reflux esophagitis among the Chinese is 5%, which is lower than in Western countries.

Enteric-coated peppermint-oil capsules in the treatment of irritable bowel syndrome: a prospective, randomized trial.

To determine the efficacy and tolerability of an enteric-coated peppermint-oil formulation (Colpermin), we conducted a prospective, randomized, double-blind, placebo-controlled clinical study in 110 outpatients (66 men/44 women; 18-70 years of age) with symptoms of irritable bowel syndrome. Patients took one capsule (Colpermin or placebo) three to four times daily, 15-30 min before meals, for 1 month. Fifty-two patients on Colpermin and 49 on placebo completed the study. Forty-one patients on Colpermin (79%) experienced an alleviation of the severity of abdominal pain (29 were pain-free); 43 (83%) had less abdominal distension, 43 (83%) had reduced stool frequency, 38 (73%) had fewer borborygmi, and 41 (79%) less flatulence. Corresponding figures for the placebo group were: 21 patients (43%) with reduced pain (4 were pain-free), 14 (29%) with reduced distension, 16 (32%) with reduced stool frequency, 15 (31%) with fewer borborygmi, and 11 (22%) with less flatulence. Symptom improvements after Colpermin were significantly better than after placebo (P < 0.05; Mann-Whitney U-test). One patient on Colpermin experienced heartburn (because of chewing the capsules) and one developed a mild transient skin rash. There were no significant changes in liver function test results. Thus, in this trial, Colpermin was effective and well tolerated.

Relationship between C14 urea breath test values and solid-phase gastric emptying time in non-ulcer dyspepsia patients.

BACKGROUND: Non-ulcer dyspepsia (NUD) is a poorly understood syndrome often found with endoscopic evidence of gastritis; Helicobacter pylori (Hp) is a common and important cause of gastritis. In the recent literature, gastric hypomotility is thought to be a cause of NUD. Thus, this investigation studied the relationship between Hp and delayed gastric emptying in NUD patients. METHODS: Using a radionuclide-labelled solid meal to calculate gastric emptying time (GET) of 78 NUD patients. The carbon-14 urea breath test (C14 UBT) was used to quantitate Hp infection. RESULTS: The prevalence of Hp infection in patients with NUD reached 59%. There was a strong association of Hp infection with advanced age (p = 0.0091). There was no significant difference between solid-phase GET and C14 UBT values among three different age groups (young, middle, old) of NUD patients. There was no difference among sex, age, body weight and solid-phase GET between Hp-positive and Hp-negative NUD patients. However the solid-phase GET was significantly prolonged in patients with NUD, compared with the controls. CONCLUSIONS: Solid-phase GET is not correlated with the C14 UBT values, and Hp gastric colonization does not account for dyspeptic syndrome in NUD patients.