Félix Junquera

Increased expression of angiogenic factors in human colonic angiodysplasia

OBJECTIVE:Angiodysplasia of the colon is a distinct vascular abnormality characterized by focal accumulation of ectatic vessels in the mucosa and submucosa. To investigate whether angiogenesis contributes to the pathogenesis of human colonic angiodysplasia, we examined the expression of basic fibroblast growth factor (bFGF) and vascular endothelial growth factor (VEGF), and its endothelial cell receptors flt-1 and KDR.METHODS:Immunohistochemistry was performed in sections of specimens obtained from 18 patients with colonic angiodysplasia and from eight patients with colon cancer and its adjacent, histologically normal margins of resection. We used affinity-purified rabbit polyclonal antibodies and a streptoavidin–biotin peroxidase method.RESULTS:We detected strong immunoreactivity for vascular endothelial growth factor, homogeneously distributed in the endothelial lining of blood vessels of all sizes in 16 (89%) specimens of colonic angiodysplasia and in seven (88%) patients with colon cancer. In contrast, very limited immunoreactivity was found in normal colon. Vascular staining for flt-1 was observed in eight (44%) and one (12.5%) of the colonic angiodysplasia or colon cancer specimens, respectively, but not in normal colon. Vascular immunoreactivity for basic fibroblast growth factor was observed in seven (39%) specimens from patients with colonic angiodysplasia, whereas either very limited or no immunostaining was found in sections from specimens of patients with colon cancer and its normal margins.CONCLUSIONS:In human colonic angiodysplasia, increased expression of angiogenic factors is likely to play a pathogenic role.

Long-term efficacy of octreotide in the prevention of recurrent bleeding from gastrointestinal angiodysplasia.

OBJECTIVES:Preliminary studies suggested that octreotide may be therapeutic in bleeding angiodysplasia. Our aim was to investigate the efficacy of long-term octreotide therapy in the prevention of rebleeding from gastrointestinal angiodysplasia.METHODS:A cohort of 32 patients diagnosed with bleeding from angiodysplasia was treated with octreotide 50 μ 12 h subcutaneously for a 1–2 yr period. This cohort was compared with an external control group (38 patients who had received placebo [1 tablet/day] in a concurrent randomized clinical trial for the same period.RESULTS:Two patients of the octreotide group were lost to follow-up. Treatment failure occurred in seven of 30 (23%) patients in the octreotide group and in 17 of 35 (48%) in the placebo group (three dropouts before first visit) (P = 0.043). The actuarial probability of remaining free of rebleeding at 1 and 2 yr of follow-up was 77% and 68%, respectively, for the octreotide group and 55% and 36%, respectively, for the placebo group (log rank P = 0.030). Multivariate proportional hazards-regression analysis showed that octreotide therapy and previous bleeding episodes were positive and negative predictors of efficacy, respectively. No significant differences between the groups were observed according to number of bleeding episodes (0.4 ± 0.7 vs 0.9 ± 1.5, P = 0.070) and transfusion requirements (1.1 ± 2.6 vs 0.7 ± 1.5 units); however, iron requirements were lower in the octreotide than in the placebo group (22 ± 62 vs 166 ± 267 units; P < 0.001). Likewise, major adverse events (1 vs 1) and mortality (0 vs 1) were similar between groups.CONCLUSIONS:This study suggests that octreotide treatment may be beneficial in preventing rebleeding from gastrointestinal angiodysplasia.

microRNA profiling in duodenal ulcer disease caused by Helicobacter pylori infection in a Western population

Although the connection of microRNAs (miRNAs) to some diseases is well established, their involvement in chronic infections such as Helicobacter pylori has received less attention. The aim was to compare miRNA expression profiling in patients with duodenal ulcer (DU) due to H. pylori infection with that in infected patients without DU and in uninfected patients. The miRNA expression profile was determined by microarrays in antral mucosal samples from well-characterized dyspeptic patients (n = 46). The most significant set of miRNAs was subsequently analysed in an independent validation group of patients (n = 42). Transcripts for IL8, IL12p40, IL12p35 and IL23p19, the signalling molecules MYD88, GATA6, SOCS2 and STAT6 and H. pylori virulence factors cagA and VacA were analysed. Microarray experiments showed that 17 miRNAs were deregulated in the mucosa of H. pylori-infected patients. No significant differences were observed between normal and DU patients. PCR confirmed the up-regulation of miR-9, miR-146a, miR-155 and miR-650 and the down-regulation of miR-96 and miR-204 in the independent validation set of patients. Importantly, miR-9, miR-96, miR-146a and miR-650 expression was specific to chronic-active gastritis. H. pylori-infected patients showed higher levels of IL8 and IL12p40 mRNAs and lower levels of GATA6 and SOCS2 mRNAs. The antral mucosa of patients with non-active or chronic-active gastritis showed significantly lower levels of GATA6, MYD88, SOCS2 and STAT6 mRNAs compared with patients without gastritis. The down-regulation of these factors was not correlated with the expression of any of the validated miRNAs. The exact role of the miRNA changes observed will require further study.

Somatostatin plus isosorbide 5-mononitrate versus somatostatin in the control of acute gastro-oesophageal variceal bleeding: a double blind, randomised, placebo controlled clinical trial.

BACKGROUND Variceal bleeding is a severe complication of portal hypertension. Somatostatin reduces portal pressure by decreasing splanchnic blood flow, and nitrates by diminishing intrahepatic resistance. Experimental studies have shown that the combination of somatostatin and nitrates has an additive effect in decreasing portal pressure. AIM To compare the therapeutic efficacy of either intravenous infusion of somatostatin plus oral isosorbide 5-mononitrate or somatostatin alone in gastro-oesophageal variceal bleeding associated with liver cirrhosis. METHODS A unicentre, double blind, placebo controlled, clinical trial was conducted. Sixty patients bleeding from oesophageal or gastric varices were randomised to receive intravenous infusion of somatostatin (250 μg/hour) plus oral isosorbide 5-mononitrate (40 mg/12 hours) (group I) or somatostatin infusion plus placebo (group II) for 72 hours. RESULTS The two groups of patients had similar clinical, endoscopic, and haematological characteristics. Control of bleeding was achieved in 18 out of 30 patients (60%) in group I and 26 out of 30 patients (87%) in group II (p<0.05). There was no significant difference in mean transfusion requirements between the two groups: 2.6 (2.2)v 1.8 (1.6) respectively; means (SD). Mortality and side effects were similar in the two groups, but development of ascites was higher in group I (30%) than in group II (7%) (p<0.05). CONCLUSION In cirrhotic patients with acute gastro-oesophageal variceal bleeding, addition of isosorbide 5-mononitrate to somatostatin does not improve therapeutic efficacy, induces more adverse effects, and should not be used.

Increased plasma fibrinolytic activity in bleeding gastrointestinal angiodysplasia

Objective Gastrointestinal angiodysplasia is a major cause of recurrent bleeding. Haemostatic abnormalities have been implicated in the haemorrhage from these common vascular lesions but their precise contribution remains to be established. Our aim was to investigate whether bleeding angiodysplasia is associated with any specific coagulation disorder. Methods Clinical features and blood samples were prospectively obtained from 21 patients with bleeding gastrointestinal angiodysplasia 3 months after the last episode of haemorrhage. Plasma levels of von Willebrand factor, D-dimer, plasminogen activator inhibitor type 1 (PAI-1), tissue-plasminogen activator activity, tissue factor pathway inhibitor and activated factor VII (FVIIa-rTF) were measured. A group of 14 patients with bleeding duodenal ulcer were similarly studied as controls. Results Mean plasma von Willebrand factor levels were higher in angiodysplasia patients (208±12%) than in controls (143±11%) (P<0.05). D-dimer levels (661±80 ng/ml) and tissue-plasminogen activator activity levels (2.04±0.14 IU/ml) were also higher than in controls: 395±99 ng/ml and 1.6±0.1 IU/ml, respectively (P<0.05), whereas levels of PAI-1, FVIIa-rTF and tissue factor pathway inhibitor were similar in both groups. However, PAI-1 levels (31.5±11 ng/ml) were lower in high-bleeding-rate angiodysplasia (more than two bleeding episodes/year) than in low-bleeding-rate angiodysplasia (⩽2 bleeding episodes/year) (PAI-1 47±14 ng/ml) (P<0.05). In a multivariate regression analysis, the plasma level of PAI-1 was a predictor of haemorrhage from angiodysplasia (P<0.05). Conclusions Increased plasma fibrinolytic activity may contribute to bleeding from angiodysplasia. Low plasma PAI-1 levels constitute a risk factor for bleeding tendency in patients with angiodysplasia.

Metabolomic Analysis of Gastric Cancer Progression within the Correa’s Cascade Using Ultraperformance Liquid Chromatography–Mass Spectrometry

Gastric cancer (GC) is among the most common cancers worldwide. Gastric carcinogenesis is a multistep and multifactorial process beginning with chronic gastritis induced by Helicobacter pylori (H. pylori) infection. This process is often described via a sequence of events known as Correass cascade, a stepwise progression from nonactive gastritis, chronic active gastritis, precursor lesions of gastric cancer (atrophy, intestinal metaplasia, and dysplasia), and finally adenocarcinoma. Our aim was to identify a plasma metabolic pattern characteristic of GC through disease progression within the Correas cascade. This study involved the analysis of plasma samples collected from 143 patients classified in four groups: patients with nonactive gastritis and no H. pylori infection, H. pylori infected patients with chronic active gastritis, infected or noninfected patients with precursor lesions of gastric cancer, and GC. Independent partial least-squares-discriminant binary models of UPLC-ESI(+)-TOFMS metabolic profiles, implemented in a decision-directed acyclic graph, allowed the identification of tryptophan and kynurenine as discriminant metabolites that could be attributed to indoleamine-2,3-dioxygenase upregulation in cancer patients leading to tryptophan depletion and kynurenine metabolites generation. Furthermore, phenylacetylglutamine was also classified as a discriminant metabolite. Our data suggest the use of tryptophan, kynurenine, and phenylacetylglutamine as potential GC biomarkers.

Evaluación de la susceptibilidad de Helicobacter pylori a la rifaximina

Introduccion La infeccion por Helicobacter pylori afecta a mas de la mitad de la poblacion mundial y esta asociada al desarrollo de la gastritis cronica, ulceras pepticas y adenocarcinoma gastrico. La rifaximina es un nuevo antibiotico no absorbible de amplio espectro del grupo de la rifamicina que alcanza altas concentraciones en el tracto gastrointestinal. Objetivo Determinar in vitro la susceptibilidad de H. pylori frente a la rifaximina. Metodos Se estudiaron 31 cepas de H. pylori por el metodo de dilucion en agar. Como antibiotico control se utilizo la claritromicina. Como cepas control se utilizaron Staphylococcus aureus y Streptococcus pneumoniae . Las placas se leyeron a los 4 y a los 7 dias de incubacion. Se determinaron las CMI50 y las CMI90 para cada antibiotico. Se consideraron resistentes a la claritromicina las cepas con CMI > 1 μg/ml. Resultados Las CMI50 de la claritromicina a los 4 y 7 dias fueron de 0,125 μg/ml y las CMI90 a los 4 y 7 dias fueron de 8 y 16 μg/ml, respectivamente. Las CMI50 de la rifaximina a los 4 y 7 dias fueron de 1 y 2 μg/ml, respectivamente, y las CMI90 a los 4 y 7 dias fueron de 4 μg/ml. El 20% de las cepas de H. pylori fueron resistentes a la claritromicina. En estas cepas, el crecimiento de H. pylori fue inhibido a una concentracion maxima de rifaximina de 4 μg/ml. Conclusion Estos resultados indican que la rifaximina puede ser util en la erradicacion de la infeccion. Este nuevo antibiotico podria tener una mayor actividad en las cepas resistentes a la claritromicina y asi ser util en las combinaciones con este farmaco o en el tratamiento de los fracasos.

Occult H. pylori infection partially explains ‘false-positive’ results of 13C-urea breath test

Background In a previous study, UBiT-100 mg, (Otsuka, Spain), a commercial 13C-urea breath test omitting citric acid pre-treatment, had a high rate of false-positive results; however, it is possible that UBiT detected low-density ‘occult’ infection missed by other routine reference tests. We aimed to validate previous results in a new cohort and to rule out the possibility that false-positive UBiT were due to an ‘occult’ infection missed by reference tests. Methods Dyspeptic patients (n = 272) were prospectively enrolled and UBiT was performed, according to the manufacturer’s recommendations. Helicobacter pylori infection was determined by combining culture, histology and rapid urease test results. We calculated UBiT sensitivity, specificity, positive and negative predictive values (with 95% CI). In addition, we evaluated ‘occult’ H. pylori infection using two previously-validated polymerase chain reaction (PCR) methods for urease A (UreA) and 16 S sequences in gastric biopsies. We included 44 patients with a false-positive UBiT, and two control groups of 25 patients each, that were positive and negative for all H. pylori tests. Results UBiT showed a false-positive rate of 17%, with a specificity of 83%. All the positive controls and 12 of 44 patients (27%) with false-positive UBiT were positive for all two PCR tests; by contrast, none of our negative controls had two positive PCR tests. Conclusions UBiT suffers from a high rate of false-positive results and sub-optimal specificity, and the protocol skipping citric acid pre-treatment should be revised; however, low-density ‘occult’ H. pylori infection that was undetectable by conventional tests accounted for around 25% of the ‘false-positive’ results.

Inter and intra-observer concordance for the diagnosis of portal hypertension gastropathy

INTRODUCTION At present there is no fully accepted endoscopic classification for the assessment of the severity of portal hypertensive gastropathy (PHG). Few studies have evaluated inter and intra-observer concordance or the degree of concordance between different endoscopic classifications. OBJECTIVES To evaluate inter and intra-observer agreement for the presence of portal hypertensive gastropathy and enteropathy using different endoscopic classifications. METHODS Patients with liver cirrhosis were included into the study. Enteroscopy was performed under sedation. The location of lesions and their severity was recorded. Images were videotaped and subsequently evaluated independently by three different endoscopists, one of whom was the initial endoscopist. The agreement between observations was assessed using the kappa index. RESULTS Seventy-four patients (mean age 63.2 years, 53 males and 21 females) were included. The agreement between the three endoscopists regarding the presence or absence of PHG using the Tanoue and McCormack classifications was very low (kappa scores = 0.16 and 0.27, respectively). CONCLUSIONS The current classifications of portal hypertensive gastropathy have a very low degree of intra and inter-observer agreement for the diagnosis and assessment of gastropathy severity.

Identification of circulating microRNAs for the diagnosis of early-stage gastric cancer.

33Background: The development of gastric cancer (GC) is a stepwise progression from non-active gastritis (NAG), chronic active gastritis (CAG) and precursor lesions of GC (PLGC: atrophy, metaplasia). Early detection of GC improves survival rates. Recent evidence has proposed circulating microRNAs (c-miRNAs) as biomarkers. The aim was to explore the c-miRNA profile of a cohort of non-GC and GC patients in order to identify early biomarkers of GC. Methods: Thirty-eight patients were enrolled: ten with NAG, nine with H. pylori infected with CAG, eight with PLGC, and ten with GC. GC patients were at TNM stages I and II. As quality controls, synthetic RNA was added during the isolation, cDNA synthesis, and PCR steps. MiRNA profiling was performed using Exiqon Human Panel I. Exploratory significance was set at P<0.05 with fold change (FC)≥1.6. Results: Of the total of 372 miRNAs analyzed, 154 miRNAs were detected in all samples. miR-185-5p was used to normalize. Compared to NAG individuals, GC patients showed d...