Impact of the COVID-19 pandemic on Gastroenterology Divisions in Italy: A national survey

BACKGROUND

In Italy, the spread of the COVID-19 pandemic has stressed the entire healthcare system and required a huge re-organization of many Divisions, including those of Gastroenterology.

AIMS

to assess the impact of COVID-19 pandemic on Gastroenterology Divisions across Italy.

METHODS

All members of the Italian Society of Gastroenterology (SIGE) were invited to answer a web-based survey.

RESULTS

Data of 121 hospitals from all 20 Italian regions were analyzed. Overall, 10.7% Gastroenterology Divisions have been converted to Covid Units. Outpatients consultations, endoscopic and ultrasound procedures were limited to urgencies and oncology indications in 85.1%, 96.2% and 72.2% of Units, respectively, and 46.7% of them suspended the screening for colorectal cancer. Moreover, 72.2% of the staff received a training for use of personal protective equipment, although 45.5% did not have sufficient devices for adequate replacement. Overall, 132 healthcare workers in 41 Gastroenterology Divisions were found to be infected.

CONCLUSION

This is the first study to evaluate, at a country level, the impact of COVID-19 outbreak on Gastroenterology Divisions. Substantial changes of practice and reduction of procedures have been recorded in the entire country. The long-term impact of such modifications is difficult to estimate but potentially very risky for many digestive diseases.

Membrane human equilibrative nucleoside transporter 1 is associated with a high proliferation rate and worse survival in resected intrahepatic cholangiocarcinoma patients not receiving adjuvant treatments

Human equilibrative nucleoside transporter 1 (hENT-1) is a membrane nucleoside transporter mediating the intracellular uptake of nucleosides and their analogues. hENT-1 was recently reported to have a predictive role in intrahepatic cholangiocarcinoma (iCC) patients receiving adjuvant gemcitabine-based chemotherapy, but its biological and clinical significance in iCC remains unsettled. This study investigated the role of hENT-1 in regulating tumour growth and predicting the survival of 40 resected iCC patients not receiving adjuvant treatments. hENT-1 expression was found to be significantly higher in iCC than in the matched non-tumoural liver. Patients harbouring hENT-1 localised on the tumour cell membrane had a worse overall survival than membrane hENT-1-negative patients (median 21.2 months vs 30.3 months, p = 0.031), with an adjusted hazard ratio of 2.8 (95% confidence interval 1.01-7.76). Moreover, membrane hENT-1-positive patients had a higher percentage of Ki67-positive cells in tumour tissue than membrane hENT-1-negative patients (median 23% vs 5%, p < 0.0001). Functional analyses in iCC cell lines revealed that hENT-1 silencing inhibited cell proliferation and induced apoptosis in HUH-28 cells expressing hENT-1 on the cell membrane, but not in SNU-1079 cells expressing the transporter only in the cytoplasm. Overall, these findings suggest that membrane hENT-1 is involved in iCC proliferation and associated with worse survival in resected iCC patients. Further prospective studies on larger cohorts are required to confirm these results and better define the potential prognostic role of membrane hENT-1 in this setting of patients.

Van-Gogh-like 2 antagonises the canonical WNT pathway and is methylated in colorectal cancers

Background:

Aberrant activation of the canonical WNT signaling is a feature of colorectal cancer (CRC). Van-Gogh-like 2 (VANGL2) belongs to the non-canonical WNT pathway whose activation inhibits canonical WNT signaling. In this study, we investigated the role of VANGL2 and its epigenetic regulation in CRC.

Methods:

Van-Gogh-like 2 expression and promoter methylation after 5-aza-2′-deoxycytidine (5-aza) treatment were evaluated in CRC cells. DNA samples from 418 sporadic CRCs were tested for VANGL2 promoter methylation and microsatellite instability (MSI). Proliferation, colony formation and activation of the WNT pathway were tested in cells after VANGL2 overexpression.

Results:

Van-Gogh-like 2 mRNA was significantly higher in 5-aza-treated RKO, LOVO and SW48, whereas no differences were found in SW480. Van-Gogh-like 2 was fully methylated in RKO, SW48, HCT116, DLD1 and Caco2; partially methylated in LOVO, LS174T and SW837; and unmethylated in SW480, SW620 and HT29. Higher expression of VANGL2 mRNA was found in the unmethylated cell lines. In CRC specimens (8.93% MSI), methylated VANGL2 was associated with MSI, higher grade, proximal colon location and BRAF mutation. Van-Gogh-like 2 overexpression in SW480 significantly decreased proliferation, colony formation and β-catenin levels.

Conclusion:

Van-Gogh-like 2 is frequently methylated in MSI-CRCs with BRAF mutation and may act as a tumour suppressor gene, counteracting WNT/β-catenin signaling.

JC virus infects the enteric glia of patients with chronic idiopathic intestinal pseudo-obstruction

BACKGROUND AND AIMS

Chronic idiopathic intestinal pseudo-obstruction (CIIP) is characterised by severe impairment of intestinal propulsive motility that mimics bowel obstruction. JC virus (JCV) is a polyomavirus that can infect brain glial cells causing a fatal disease, but may also be found throughout the normal gastrointestinal tract. The hypothesis that JCV infects the myenteric plexuses of patients with CIIP was tested.

METHODS

10 patients with CIIP and 61 normal specimens (30 ascending colon and 31 ileum) from patients with uncomplicated colon cancer were studied. DNA was extracted from the myenteric plexuses, and JCV T antigen (TAg) DNA and the viral regulatory region were detected by PCR and sequencing. Immunohistochemistry was performed to detect JCV viral protein expression, neuronal and glial markers. Fluorescence in situ hybridisation was performed for cellular localisation of the JCV infection.

RESULTS

Clinical studies demonstrated neurogenic impairment, and pathological analyses showed neuropathy in each patient with CIIP. JCV TAg DNA was found in the myenteric plexuses of 8/10 (80%) of the patients with CIIP and 3/31 (9.7%) of the control patients (p<0.001). All samples were JCV Mad-1 strains. Seven of the 10 CIIP specimens expressed both JCV TAg and the JCV viral protein VP1, while none of the controls expressed either. JCV infection co-localised with glial fibrillary acidic protein expression, a marker of enteric glial cells.

CONCLUSION

JCV infection occurs in the myenteric plexuses of patients with CIIP. The JCV localisation in enteroglial cells suggests a possible pathological role for this virus in enteric neuropathy.

Cytokine gene polymorphisms in gastric cancer patients from two Italian areas at high and low cancer prevalence

Polymorphisms of interleukin-1beta (IL-1beta), IL-1 receptor antagonist (IL1-RN), and tumor necrosis factor-alpha (TNF-alpha) genes are supposed to be key determinants of gastric cancer risk. Our aim was to study the association between these polymorphisms and gastric cancer in two areas characterized by high (Pavia/Bologna, North Italy) and low (San Giovanni Rotondo, South Italy) gastric cancer prevalence. Genomic DNA was obtained from 216 healthy donors and 98 gastric cancer patients from Pavia and Bologna, and 146 healthy donors and 86 gastric cancer patients from San Giovanni Rotondo. Two SNP in IL-1beta (-511 C/T) and TNF-alpha (-308 G/A) as well as the VNTR polymorphism of IL-1RN locus were studied. A significant linkage disequilibrium was found between IL-1beta -511 and IL-1RN. Genotype and allele frequencies at the IL-1beta, IL-1RN, and TNF-alpha loci in gastric cancer cases were not significantly different from controls. An epistatic effect between IL-1beta -511 and IL-1RN was found with the IL-1beta -511C/IL-1RN*2 haplotype conferring a significant protection against the intestinal-type of gastric cancer in the Southern population. In conclusion, IL-1beta, IL1-RN, and TNF-alpha genotypes are not associated with gastric cancer in Italian patients. An epistatic interrelationship between IL-1beta -511 and IL-1RN confers protection against gastric cancer in low-risk Italian population.

Measuring dyspepsia: a new severity index validated in Bologna

BACKGROUND

Measurement of the severity of dyspepsia symptoms before and after treatment and determining what is a significant change is a major problem in designing dyspepsia treatment studies.

OBJECTIVES

To assess the reproducibility, validity and responsiveness to treatment of a dyspepsia questionnaire to be used in clinical and population-based studies.

METHODS

Seventy-three dyspeptic patients (35 male, 38 female; mean age 52 years) and 75 healthy volunteers (32 male, 43 female; mean age 52 years) were included. Subjects were interviewed for the presence/absence and severity/frequency of 19 gastrointestinal symptoms. Severity was measured on a 5-point scale. Frequency was also recorded on a 5-point scale. A global symptom index (severity x frequency) was calculated for the eight most severe symptoms; a mean global symptom index (8-MGSI) was considered for the evaluation of the instrument. To evaluate intra-observer variation, one author interviewed subjects (T0) and then repeated the interview 1 week later (T1). For inter-observer variation, two authors interviewed patients. VALIDITY was measured by comparing 8-MGSI of the dyspepsia patients to those of healthy volunteers. Responsiveness was assessed by comparing mean global symptom index before and 1 month after appropriate therapy.

RESULTS

Reproducibility: The mean 8-MGSI was 4.5 at T0 and 3.7 at T1 with a correlation coefficient of 0.62. As for inter-observer variation, the average 8-MGSI was 4.8 by the first author and 3.9 by the second with a correlation coefficient of 0.60.

VALIDITY

The mean 8-MGSI was, respectively, 1.4 in healthy volunteers and 4.8 in dyspeptic patients (p = 0.001). Responsiveness: After treatment, a significant improvement in 8-MGSI was detected (p = 0.001).

CONCLUSIONS

This questionnaire is a reliable, valid and responsive instrument for measuring the presence, severity and frequency of dyspepsia.

The VEPSY UPDATED Project: clinical rationale and technical approach

More than 10 years ago, Tart (1990) described virtual reality (VR) as a technological model of consciousness offering intriguing possibilities for developing diagnostic, inductive, psychotherapeutic, and training techniques that can extend and supplement current ones. To exploit and understand this potential is the overall goal of the "Telemedicine and Portable Virtual Environment in Clinical Psychology"--VEPSY UPDATED--a European Community-funded research project (IST-2000-25323, www.cybertherapy.info). Particularly, its specific goal is the development of different PC-based virtual reality modules to be used in clinical assessment and treatment of social phobia, panic disorders, male sexual disorders, obesity, and eating disorders. The paper describes the clinical and technical rationale behind the clinical applications developed by the project. Moreover, the paper focuses its analysis on the possible role of VR in clinical psychology and how it can be used for therapeutic change.

Endoscopic surveillance in Barrett's esophagus

Barrett's esophagus (BE), a complication of chronic gastroesophageal reflux disease (GORD), is a condition that is premalignant for adenocarcinoma of the esophagus and esophagogastric junction. Esophageal adenocarcinoma, once an uncommon entity, has been growing rapidly in incidence over the last two decades in several parts of the world. Barrett's esophagus is a change in the esophageal epithelium of any length that can be recognized at endoscopy and is confirmed to have intestinal metaplasia by biopsy (American College of Gastroenterology guidelines). Because of its premalignant nature, it is recommended that patients with BE undergo regular endoscopic surveillance. The recommendation for endoscopic surveillance is based on unproved and controversial assumptions including: 1) the assumption that Barrett's esophagus adversely influences survival; 2) the assumption that endoscopic surveillance can reliably detect early, curable neoplasia in the columnar lined esophagus. Moreover, the low incidence of adenocarcinoma (reported cancer incidence rates in prospective studies on BE range between 0.5% and 1.9%) is used to support an approach of not surveying patients with Barrett's esophagus. Despite these not convincing data, endoscopic surveillance is considered ''reasonable'' and ''desirable'' by the gastroenterological associations and consensus meetings. Endoscopic surveillance for cancer in Barrett's esophagus (BE) is performed primarily to seek dysplasia, to prevent the progression to invasive malignancy; however, one of the limitations of using dysplasia is a lack of understanding of its natural history. The efficacy of endoscopic surveillance for Barrett's esophagus is likely to remain unclear for a long time. The American College of Gastroenterology has recommended the following practice guidelines: a) for patients with no dysplasia, surveillance endoscopy is recommended at an interval of every 2 to 3 years; b) for patients with low grade dysplasia, surveillance endoscopy every 6 months for the first year is recommended, followed by yearly endoscopy if the dysplasia has not progressed in severity; c) for patients with high grade dysplasia, two alternatives are proposed after the diagnosis has been confirmed by an expert gastrointestinal pathologist. One alternative is intensive endoscopic surveillance until intramucosal cancer is detected at an interval of every 3-6 months. The other alternative is esophageal resection. In the situation of indeterminate dysplasia, whereas the pathologist can not come to definite diagnosis, control biopsies are proposed after 2 months of adequate acid suppression by means of proton pump inhibition. In all cases, the technique of random, four quadrant biopsies taken every 2 cm in the columnar-lined esophagus for standard histologic evaluation is recommended. Any grossly abnormal areas may be biopsied too. One can expect however that during the next future these protocol will change considering new data on dysplasia detection (biochemical markers, flow cytometry), new techniques to identify dysplasia (chromoendoscopy, endosonography, coherence optical tomography, fluorescence techniques) and development of better ablative techniques. At present a marker other than dysplasia identifying a high risk group for cancer on which to focus endoscopic surveillance has not yet been established.

Helicobacter pylori and functional dyspepsia: review of previous studies and commentary on new data

Many studies have attempted to prove a link between Helicobacter pylori infection and functional dyspepsia but the results have been conflicting. Several mechanisms have been postulated for how H pylori associated inflammation disturbs antral and duodenal function but no pathophysiological explanation of how H pylori may cause dyspeptic symptoms is presently available.

Low-dose lansoprazole and clarithromycin plus metronidazole vs. full-dose lansoprazole and clarithromycin plus amoxicillin for eradication of Helicobacter pylori infection

AIM

To compare, in a randomized controlled trial, the efficacy and tolerability of two 1-week triple therapies for Helicobacter pylori eradication.

METHODS

One hundred and thirty-four consecutive patients with non-ulcer dyspepsia and H. pylori infection were randomized to receive lansoprazole 30 mg once daily, clarithromycin 250 mg twice daily, and metronidazole 500 mg twice daily (LCM group), or lansoprazole 30 mg twice daily, clarithromycin 500 mg twice daily, and amoxicillin 1000 mg twice daily (LCA group). H. pylori status was assessed by rapid urease test, histology and 13C-urea breath test before and after therapy.

RESULTS

At 3 months, H. pylori eradication (intention- to-treat/per protocol analysis) was 92.4%/93.8% in the LCM group and 83.1%/85.7% in the LCA group (P=N.S.). Side-effects were more frequently reported in the LCA group (37.9%) than in the LCM group (19.7%) (P < 0.05).

CONCLUSIONS

In this open, randomized controlled trial, eradication of H. pylori by low-dose lansoprazole and clarithromycin plus metronidazole was higher with significantly less side-effects than by full-dose lansoprazole and clarithromycin plus amoxicillin. This finding may be related to the stronger synergism of clarithromycin plus metronidazole, even at lower doses, than of clarithromycin plus amoxicillin. Considering the lower cost as well, LCM should be preferred to LCA in the eradication of H. pylori.

The Loiano-Monghidoro population-based study of Helicobacter pylori infection: prevalence by 13C-urea breath test and associated factors

OBJECTIVES

As part of a cross-sectional study on cholelithiasis, 1533 out of 1840 residents in Loiano/Monghidoro, a rural area in Northern Italy (792 men, 741 women, age range 28-80 years), agreed to be further evaluated in relation to their Helicobacter pylori status.

METHODS

Each participant performed a 13C-urea breath test (13C-UBT) and provided information on sociodemographic, lifestyle and clinical characteristics.

RESULTS

The 13C-UBT was positive in 1041 subjects (67.9%; men: 69%; women: 67%) and was positively associated with increasing age (P < 0.001), alcohol consumption (P < 0.01), a higher number of siblings (P < 0.001) and a personal history of peptic ulcer (P < 0.01), but inversely with a nonmanual occupation (P < 0.001). Overall, H. pylori infection was unrelated to smoking, house pets, and a family history of gastroduodenal diseases. The prevalence of H. pylori infection was 72% in subjects reporting one or more dyspeptic symptoms and 65% among asymptomatic participants (P < 0.001); a multivariate analysis showed that only epigastric pain was significantly, although weakly, associated with 13C-UBT positivity.

CONCLUSIONS

This large population-based study showed a prevalence of H. pylori infection higher than that reported by serologic surveys in urban areas. Current H. pylori infection was strongly associated with indicators of lower socioeconomic status, alcohol consumption and increasing age. A role of H. pylori infection in determining epigastric pain was suggested.

Incidence and recurrence rates of colorectal adenomas in first-degree asymptomatic relatives of patients with colon cancer

OBJECTIVES

Subjects with one first-degree relative affected with colorectal cancer are considered to be at increased risk of colorectal adenomas. We compared the recurrence and incidence rates of colorectal adenomas among subjects with one first-degree relative with colorectal cancer and those without family history.

METHODS

A series of consecutive asymptomatic subjects successfully underwent a colonoscopy, were found to have either normal results or at least one adenoma, provided a detailed family history, and were offered a second colonoscopy 3 yr later; 190 out of 436 subjects accepted, 134/172 with one or more adenomas and 56/264 with no abnormalities at the initial examination. A first-degree family history was reported by 43/134 and 26/56, respectively.

RESULTS

By multivariate analysis, the presence of adenomas at follow-up examination was significantly associated with a positive family history of colorectal cancer in both subgroups, those with a previously resected adenoma (odds ratio = 2.23, 95% CI = 1.04-4.79) and those without (odds ratio = 8.95, CI = 1.29-62.22).

CONCLUSION

A history of one first-degree relative with colorectal cancer is associated with a significant increase in 3-yr cumulative incidence and recurrence rates of adenomas.

Mad-1 is the exclusive JC virus strain present in the human colon, and its transcriptional control region has a deleted 98-base-pair sequence in colon cancer tissues

JC virus (JCV), along with other members of the polyomavirus family, encodes a class of highly conserved proteins, T antigens, that are capable of inducing aneuploidy in cultured cells. We have previously isolated T-antigen DNA variants of JCV from both colon cancer tissues and the corresponding nonneoplastic gastrointestinal tissues, raising new questions about the role of JCV in the development of chromosomal instability of the colon. Based on the sequence of the transcriptional control region (TCR), JCV can be classified as archetype or tandem repeat variants. Among the latter, Mad-1, the prototype virus first isolated from a patient with progressive multifocal leukoencephalopathy, is characterized by lacking the 23- and 66-bp sequences that are present in the archetype and by duplication of a 98-bp sequence. In this study, we evaluated differences in the TCR of JCV isolated from colon cancer tissues and nonneoplastic epithelium. To characterize JCV variants, we first treated eight pairs of DNA samples from colon cancers and noncancerous tissue with topoisomerase I and then amplified and cloned the JCV TCR. We obtained 285 recombinant clones from the JCV TCR, 157 from nonneoplastic samples, and 128 from colon cancer tissues. Of these clones, 262 spanned the length of the JCV Mad-1 TCR: 99.3% from nonneoplastic samples and 82.8% from colon cancer tissues. In sequencing 54 clones in both directions, we did not find archetype JCV either in the nonneoplastic tissue or in the cancer samples. From all colon cancer tissues, 18 clones had a deletion of one 98-bp tandem repeat. This deleted strain was not detected in any of the nonneoplastic tissues (14 versus 0% [chi(2) = 23.6; P < 0.001]). Our study demonstrates that the only JCV strain present in the human colon is Mad-1, and the variant with a single 98-bp sequence is found exclusively in the cancer tissues. This strain may be involved in the development of chromosomal instability.

Genetic heterogeneity in familial juvenile polyposis

Juvenile polyposis syndrome (JPS) is an autosomal dominant syndrome characterized by multiple gastrointestinal hamartomatous polyps in the absence of the extraintestinal features that are classic for other hamartomatous polyposis syndromes, such as Bannayan-Riley-Ruvalcaba syndrome (BRRS) and Cowden disease (CD). About 50% of BRRS and >80% of CD demonstrate germ-line mutations in the tumor suppressor and dual phosphatase, PTEN. Germ-line mutation of PTEN as a cause for JPS in a child is controversial because extraintestinal manifestations that would exclude JPS could appear after adolescence, altering the clinical diagnosis. Here, we investigated a family in which the 55-year-old father, who lacks thyroid or skin findings characteristic of CD, demonstrated a germ-line mutation in PTEN that was passed to identical twin daughters, who both manifested JPS. The mutation was a deletion of five bases beginning seven bases from the start of exon 4 of PTEN, which caused aberrant transcripts by reverse transcription-PCR that were absent from a normal individual. Thus, mutations in PTEN are associated with JPS in addition to CD and some BRRS families, although the incidence of PTEN germ-line mutations in JPS might be more rare than that reported for SMAD4, a gene found to be mutated in approximately one-half of the JPS families investigated.

JC virus DNA sequences are frequently present in the human upper and lower gastrointestinal tract

BACKGROUND & AIMS

JC virus (JCV), a human polyomavirus, has been found in a limited number of normal human tissues and cancers. The oncogenic potential of this virus is mediated by a transforming protein, the T antigen (TAg). We have previously demonstrated the presence of JCV-TAg in colorectal cancers, in adjacent normal colonic mucosa from these patients, and in the human colon cancer cell line SW480. The mode of transmission of this virus is unclear, and we hypothesized that the gastrointestinal (GI) tract may be a reservoir for the virus.

METHODS

DNA was extracted from 129 normal GI tissue samples collected from 33 patients. Topoisomerase I-assisted polymerase chain reaction (PCR) was used to detect the virus using exact and degenerate primers. Nested PCR and Southern blot analysis confirmed the identity of the PCR products. Single-stranded conformation polymorphism (SSCP) analysis and sequencing were used to evaluate the presence of viral quasispecies.

RESULTS

JCV sequences were found in 75.8% of patients (70.6% of upper GI and 81.2% of colonic samples); no significant differences in rates of infection were found by site. The use of degenerate primers combined with topoisomerase I treatment led to viral detection in 58.9% of samples, compared with 27.9% of samples using exact primers and topoisomerase I (P < 0.01). SSCP and sequencing analysis confirmed the amplification of viral quasispecies and the authenticity of TAg sequences.

CONCLUSIONS

The results show that JCV DNA sequences are highly prevalent in the human upper and lower gastrointestinal tract of immunocompetent individuals.

Steady-state regulation of the human DNA mismatch repair system

Steady-state levels of human DNA mismatch repair (MMR) transcripts and proteins were measured in MMR-proficient and -deficient cell lines by the newly developed competitive quantitative reverse transcription- polymerase chain reaction and Western analysis normalized with purified proteins. In MMR-proficient cells, hMSH2 is the most abundant MMR protein and is expressed 3 to 5 times more than hMLH1. The hMLH1 protein was expressed 1.5 to 2.5 times more than hPMS2. Steady-state levels of mRNA expression correlated well with protein expression. hMSH2-mutated LoVo cells did not express detectable hMSH3 or hMSH6 proteins. Similarly, hMLH1-mutated HCT116 cells did not express detectable hMLH1 or hPMS2 protein, whereas in hMLH1-restored HCT116+ch3 cells, hPMS2 protein was re-expressed. In hMSH6-mutated HCT15 cells, both hMSH3 protein and mRNA were increased. In SV40-transformed lung fibroblasts, all MMR mRNAs and proteins examined were expressed at levels 1.5-5-fold higher than in their nontransformed counterpart. The steady-state levels of MMR proteins indicate that substantially more hMutS proteins, which are involved in DNA mismatch recognition, are present in comparison with the hMutL proteins. Stability of hMSH3 and hMSH6 proteins appears to depend upon the presence of the hMSH2 protein, and, similarly, the stability of the hPMS2 protein depends upon hMLH1. When the hMSH6 is mutationally inactivated, hMSH3 increases by both transcriptional up-regulation and enhanced protein stability. A balanced up-regulation of all of the components was seen after viral transformation in a fibroblast model. Quantitative changes of the MMR components are a potential mechanism to modify the DNA MMR capabilities of a cell.

Validation of the 13C-urea breath test for the diagnosis of Helicobacter pylori infection in children: a multicenter study

OBJECTIVE

The 13C-urea breath test (13C-UBT) is a safe, noninvasive, and accurate test for the detection of Helicobacter pylori (H. pylori) infection in adults. The aim of this study was to evaluate sensitivity and specificity of 13C-UBT in children using different types of test meal, doses of 13C-urea and breath sampling intervals. As yet, a validated, standardized 13C-UBT protocol for children has not been formulated.

METHODS

13C-UBT was performed in 115 children and repeated within 3 days, modifying the test meal or the dose of 13C-urea. H. pylori status was assessed by histology and rapid urease test. 13C-UBT was performed using 100 mg or 50 mg of 13C-urea and a fatty test meal (100 FA; 50 FA), 50 mg of 13C-urea, and a carbohydrate test meal (50 CA). Breath samples were collected every 10 min for 60 min.

RESULTS

The 13C-UBT in children was highly sensitive and specific with all three protocols used. The best combination of sensitivity (97.92%) and specificity (97.96%) was obtained with Protocol 50 FA at 30 min with a cut-off of 3.5 per mil.

CONCLUSIONS

The 13C-UBT is an accurate test for the detection of H. pylori infection also in children. Administration of 50 mg of 13C-urea, a fatty test meal, and breath sampling at 30 min appears to be the most convenient protocol.

Helicobacter pylori: optimum diagnosis and test of cure

The fact that about 50% of the world's population is infected with Helicobacter (H.) pylori and the important role that this bacterium plays in public health have been important incentives in the search for accurate diagnostic methods. A large number of invasive and non-invasive methods have been used to diagnose H. pylori infection. Each method has its advantages and disadvantages and each practitioner should choose the best diagnostic method according to the facilities available. Non-invasive tests for the diagnosis of H. pylori infection are largely used in clinical practice and in management of patients with gastroduodenal disease. Serology is the most widespread test but its use is not advised in the post-treatment follow-up. The Urea Breath Test is a simple, safe and highly accurate method ideal for evaluating the short-term follow-up of H. pylori eradication after therapy.

Efficacy of lansoprazole in eradicating Helicobacter pylori: a meta-analysis

BACKGROUND

The combination of lansoprazole with antibiotics either as double or triple therapy has demonstrated an H. pylori eradication rate of between 80 and 90%. With the aim of providing a complete revision of the results of these clinical studies and a quantification of the efficacy of lansoprazole in eradicating H. pylori and healing peptic ulcers, we have undertaken a meta-analysis of all the controlled studies published in the literature.

METHODS

This meta-analysis reviewed all randomized, controlled clinical trials published as full text articles in English between 1993 and 1996 that reported the efficacy of lansoprazole treatment as monotherapy or in combination with antibiotics in the treatment of peptic ulcer and in eradicating H. pylori. Articles were identified from the literature, which included both manual and computerized research (MEDLINE) and references provided by articles in this area. In order to compare the efficacy of triple therapy comprising lansoprazole vs. another PPI, data from abstracts (n = 5) were used, as no full text articles were located.

RESULTS

This systematic review of the literature documents that lansoprazole has a high degree of efficacy in eradicating H. pylori, above all when used within treatment schemes including amoxicillin or clarithromycin, and metronidazole or tinidazole. This efficacy is comparable to that of other PPIs.

CONCLUSIONS

Triple therapy allows the eradication of H. pylori in more than 85% of cases in patients with peptic ulcer. In addition, there is a substantial comparability of the efficacy of lansoprazole and omeprazole when they are used together with other anti-infective agents. Thus, lansoprazole appears to offer an option in the eradication of H. pylori.

Efficacy and safety of three 7-day Helicobacter pylori eradication regimens containing ranitidine bismuth citrate

BACKGROUND

This multicentre, randomized study was designed to assess the clinical efficacy, safety and tolerability of three novel 7-day triple therapies containing ranitidine bismuth citrate (RBC) and two antibiotics.

METHODS

We studied patients with non-ulcer dyspepsia and gastritis who were randomly assigned to one of three treatment regimens given for 7 days in a b.d. dosing schedule: RBC 400 mg plus clarithromycin 250 mg and tinidazole 500 mg (RBCCT): RBC 400 mg plus clarithromycin 500 mg and amoxycillin 1 g (RBCCA); RBC 400 mg plus tinidazole 500 mg and amoxycillin 1 g (RBCTA). H. pylori status was determined by CLO-test, histology and 13C-urea breath test. A repeat breath test was performed at least 28 days after completion of therapy to assess eradication.

RESULTS

One hundred and fifty-seven patients were eligible for intention-to-treat analysis (ITT) and 140 patients completed the study and returned for assessment of eradication. Intention-to-treat cure rates were 78% with RBCCT, 71% with RBCCA and 61% with RBCTA. An all-patients-treated analysis (APT), performed on evaluable patients, demonstrated eradication rates of 85% with RBCCT, 81% with RBCCA and 70% with RBCTA. No statistically significant difference was found between treatment groups. Twenty-four patients experienced side-effects, but in only seven cases was treatment discontinued due to adverse events.

CONCLUSIONS

A 7-day course of RBC, clarithromycin and either tinidazole or amoxycillin provides a good rate of H. pylori eradication. Three novel RBC-based triple therapies proved to be safe and well tolerated, with discontinuations due to side-effects occurring in less than 5% of cases.

Evaluation of short-term low-dose triple therapy for the eradication of Helicobacter pylori by factorial design in a randomized, double-blind, controlled study

BACKGROUND

Studies demonstrating the efficacy of short-term low-dose triple therapies including omeprazole (O), clarithromycin (C) and a nitroimidazole (tinidazole, T) for Helicobacter pylori eradication have largely been open and uncontrolled, and have not assessed antibiotic sensitivity. Simpler regimens using the component drugs have not been evaluated.

AIM

To evaluate the OCT regimen in a randomized, controlled trial, testing for pre- and post-treatment antibiotic resistance and comparing, in a factorial design, the OCT regimen with simpler combinations of its components.

METHODS

One hundred and twenty-eight patients (68 males, 60 females, age 22-80 years, mean 53 years) with H. pylori gastritis were randomly assigned to one of the following four treatment groups: (C) clarithromycin 250 mg b.d.; (OC) omeprazole 20 mg o.d. + clarithromycin 250 mg b.d.; (CT) clarithromycin 250 mg b.d. + tinidazole 500 mg b.d.; (OCT) omeprazole 20 mg q.d.s. + clarithromycin 250 mg b.d. + tinidazole 500 mg b.d. The drugs were administered for 1 week. Medical interview, upper gastrointestinal endoscopy (with four antral and four corpus biopsies) and the 13C-urea breath test were carried out for all patients prior to and 4 weeks after treatment. Biopsy specimens were used for the urease test, histology, and culture and sensitivities.

RESULTS

All but one patient completed treatment. Side-effects were rare and mild in all groups. The eradication rate was 93.8% in group OCT, 59.4% in group CT, 31.3% in group OC and 6.3% in group C. Pre-treatment metronidazole resistance was 12.8%, clarithromycin 1.1% and, to both antibiotics, 2.1%. In patients with pre-treatment metronidazole resistance, the eradication rate was 75% in group OCT and 33% in group CT. Post-treatment resistance to clarithromycin was induced in 28.5% of the failures in group C, but in none of group OC. Resistance to both antibiotics occurred in 22.2% of the failures in group CT and in none of group OCT.

CONCLUSIONS

(i) The high efficacy of the OCT regimen is proved and each of the individual components of the regimen is essential to the result, possibly via a synergistic effect. (ii) Pre-treatment metronidazole resistance is scarcely relevant to the outcome. (iii) Acquired resistance is essentially nil if omeprazole is part of the regimen.

Urea breath tests for the detection of Helicobacter pylori infection

BACKGROUND

Helicobacter pylori is recognized as an important human pathogen. The urea breath test, using either 13C or 14C, provides a noninvasive diagnostic method for the detection of active H. pylori infection.

METHODS

We review the data regarding the utility of the urea breath test in the diagnosis and follow-up of patients with suspected H. pylori infection.

RESULTS

Following its ingestion, labeled urea is hydrolyzed by H. pylori urease, producing ammonia and labeled CO2, which is absorbed and can be detected in expired breath. The urea breath test provides a semiquantitative assessment of the load of H. pylori and overcomes the problem of the sampling error due to the patchy distribution of the infection. 13C-urea breath test has an advantage over the 14C version, because the 13C isotope is a nonradioactive natural isotope; therefore, a user's license is unnecessary, making simple the handling and mailing of samples. The 13C-urea breath test is preferred in children and expectant mothers.

CONCLUSION

The high sensitivity, and specificity of the 13C-urea breath test are such that it can be considered a clinical gold standard against which other diagnostic methods can be validated. This test can be used as the sole method for evaluating the effectiveness of treatment of H. pylori infection.

Fine structure of active ribosomal genes

The structure of active ribosomal genes in the newt Notophthalmus viridescens has been studied at the higher resolution permitted by negative staining. Spherical particles, 70 A to 100 A in diameter are seen on the non-transcribing "spacer" regions, but were absent from certain regions of the transcribing "matrix". The matrix core often appears thicker than a double strand of DNA. These results are discussed in the light of the recently discovered subunit structure of chromatin, and in relation to the question of the disposition of histones during transcription.