Helicobacter pylori vacA and cagA genotypes in patients from northeastern Brazil with upper gastrointestinal diseases

Helicobacter pylori causes chronic gastric inflammation and significantly increases the risk of duodenal and gastric ulcer disease and distal gastric carcinoma. In this study, we evaluated the Helicobacter pylori vacA and cagA genotypes in patients from a Brazilian region where there is a high prevalence of gastric cancer. Polymerase chain reaction (PCR) was used to investigate vacA mosaicism and cagA status in the gastric mucosa of 134 H. pylori-positive patients, including 76 with gastritis: 28 with peptic ulcer disease and 30 with gastric cancer. The s1m1 variant was the predominant vacA genotype observed, whereas the s1 allele was more frequently observed in patients with more severe diseases associated with H. pylori infection [p = 0.03, odds ratio (OR) = 5.72, 95% confidence interval (CI) = 1.15-38.60]. Furthermore, all of the s1 alleles were s1b. Mixed vacA m1/m2 strains were found more frequently in patients with gastric cancer and a cagA-positive status was significantly associated with gastric cancer (p = 0.016, OR = 10.36, 95% CI = 1.35-217.31). Patients with gastric cancer (21/21, 100%, p = 0.006) or peptic ulcers (20/21, 95%, p = 0.02) were more frequently colonised by more virulent H. pylori strains compared to gastritis patients (41/61, 67.2%). In conclusion, in the northeastern of Brazil, which is one of the regions with the highest prevalence of gastric cancer in the country, infection with the most virulent H. pylori strains, carrying the cagA gene and s1m1 vacA alleles, predominates and is correlated with more severe H. pylori-associated diseases.

Hepatitis C virus quantification in serum and saliva of HCV-infected patients

The hepatitis C virus (HCV) can be detected in blood and other bodily fluids, such as saliva, semen and gastric juices. The aim of this study was to compare the HCV viral loads in the serum and saliva of infected patients. Twenty-nine patients with detectable HCV RNA in their serum and saliva were included in this study. The HCV viral loads were determined through quantitative real-time polymerase chain reactions. The median viral RNA levels were 5.78 log10 copies in the serum and 3.32 log10 copies in the saliva. We observed that the salivary HCV viral load was significantly lower than the viral load in the serum. Further studies are required to understand the role of saliva in the diagnosis, management and potential transmission of HCV.

Comparison of the infectivity of Trypanosoma cruzi insect-derived metacyclic trypomastigotes after mucosal and cutaneous contaminative challenges

Trypanosoma cruzi infects humans when infected triatomine vector excreta contaminate breaks in skin or mucosal surfaces. T. cruzi insect-derived metacyclic trypomastigotes (IMT) invade through gastric mucosa after oral challenges without any visible inflammatory changes, while cutaneous and conjunctival infections result in obvious local physical signs. In this study we compared the infectivity of T. cruzi IMT in mice after cutaneous and oral contaminative challenges simulating natural infections. The 50% infective dose (ID50) for oral challenge was 100 fold lower than the ID50for cutaneous challenge, indicating that oral mucosal transmission is more efficient than cutaneous transmission.

Boerhaave Syndrom: an unusual complication of acute vomiting in a child

Introduction: Boerhaave syndrome (BS) is a spontaneous esophageal perforation, described in aged, alcoholic males, secondary to forceful vomiting. BS has rarely been described in children. Case presentation: The patient is a 7-year-old Nigerian girl. She has a past history of clinical gastro-esophageal reflux (treated conservatively with prokinetics and good evolution), malaria at the age of 3 months and an episode of acute pancreatitis at 5 years. One week prior admission, she had stopped atovaquone-proguanil (AP) prophylaxis after a trip in an endemic area. Two days prior admission, she presented several bouts of isolated acute vomiting, without fever or diarrhea. On admission, she complained of chest pain. Cardiac auscultation revealed crepitus. No subcutaneous emphysema nor respiratory distress was present. Chest radiography and CT-scan confirmed a pneumomediastinum extending to the neck. Esophageal perforation was suspected. An upper gastrointestinal endoscopy was performed and showed a small esophageal tear, grade II-III esophagitis and a single gastric ulcer without any sign of H. Pylori infection. Enteral feeds were stopped and a nasogastric sucking tube inserted. The patient made a full recovery on intravenous antibiotics and conservative treatment. Of note a second episode of subclinical acute pancreatitis, treated conservatively, probably drug-induced. Discussion: BS is a complete rupture of all layers of the esophagus, secondary to an increased intra-abdominal pressure due to incomplete opening of the cricophayngeal sphincter occurring during vomiting or cough. Rarer causes include eosinophilic or Barrett's esophagitis, HIV and caustic ingestion. Esophageal perforation in children is rare, most of time secondary to necrotizing esophagitis in the newborn, medical intervention (endoscopy, sucking, or intubation) or trauma in the older child. Our patient had none of those risk factors and it is still unclear what predisposed her to this complication. However, we believe that preceding forceful vomiting with increased abdominal pressure acting on a weakened oesophagus due to esophagitis might be responsible. We could not find any association in the literature between AP and BS nor between BS and acute pancreatitis. The origin of her recurrent pancreatitis remains unclear, reason for which genetic testing for mutations in the trypsinogen, trypsin inhibitor and CFTR genes will be performed in case of a third episode.

Insights from paleomicrobiology into the indigenous peoples of pre-colonial America - A Review

This review investigates ancient infectious diseases in the Americas dated to the pre-colonial period and considers what these findings can tell us about the history of the indigenous peoples of the Americas. It gives an overview, but focuses on four microbial pathogens from this period: Helicobacter pylori, Mycobacterium tuberculosis, Trypanosoma cruzi and Coccidioides immitis, which cause stomach ulceration and gastric cancer, tuberculosis, Chagas disease and valley fever, respectively. These pathogens were selected as H. pylori can give insight into ancient human migrations into the Americas, M. tuberculosis is associated with population density and urban development, T. cruzi can elucidate human living conditions and C. immitis can indicate agricultural development. A range of methods are used to diagnose infectious disease in ancient human remains, with DNA analysis by polymerase chain reaction one of the most reliable, provided strict precautions are taken against cross contamination. The review concludes with a brief summary of the changes that took place after European exploration and colonisation.

Imprinting of tumor-suppressor genes in human placenta.

Transcriptional deregulation in cancer has been shown to be associated with epigenetic alterations, in particular to tumor-suppressor- gene (TSG) promoters. In contrast, DNA methylation of TSGs is not considered to be present in normal differentiated cells. Nevertheless, we previously showed that the promoter of the tumor-suppressor gene APC is methylated, for one allele only, in normal gastric cells. Recently, RASSF1A has been shown to be imprinted in normal human placenta. To clarify putative TSG methylation in the placenta, 23 normal placental tissues from the first trimester, both decidua and villi, and four normal non-gestational endometrium were screened for DNA methylation by methylation-sensitive single-strand conformation analysis (MS-SSCA) and sequencing after bisulfite modification, on a panel of 12 genes known to be implicated in carcinogenesis. In all placental villi, four TSG promoters-APC, SFRP2, RASSF1A and WIF1-were hypermethylated, whereas all decidua and normal endometrium did not show any methylation. Allele-specific methylation analysis revealed that this methylation was monoallelic. Furthermore, comparison with maternal DNA indicated that APC and WIF1 were methylated on the maternal allele, whereas SFRP2 was methylated on the paternal allele. Sequence analysis of WIF1 mRNA revealed that only the unmethylated paternal allele was transcribed. The imprinting status of these TSGs is conserved during pregnancy. These results indicate that TSG imprinting is pre-existent in normal human placenta and should not be confused with carcinogenesis or pathology-induced methylation.

Water-induced modulation of Helicobacter pylori virulence properties

While the influence of water in Helicobacter pylori culturability and membrane integrity has been extensively studied, there are little data concerning the effect of this environment on virulence properties. Therefore, we studied the culturability of water-exposed H. pylori and determined whether there was any relation with the bacterium’s ability to adhere, produce functional components of pathogenicity and induce inflammation and alterations in apoptosis in an experimental model of human gastric epithelial cells. H. pylori partially retained the ability to adhere to epithelial cells even after complete loss of culturability. However, the microorganism is no longer effective in eliciting in vitro host cell inflammation and apoptosis, possibly due to the non-functionality of the cag type IV secretion system. These H. pylori-induced host cell responses, which are lost along with culturability, are known to increase epithelial cell turnover and, consequently, could have a deleterious effect on the initial H. pylori colonisation process. The fact that adhesion is maintained by H. pylori to the detriment of other factors involved in later infection stages appears to point to a modulation of the physiology of the pathogen after water exposure and might provide the microorganism with the necessary means to, at least transiently, colonise the human stomach.

Incrétines, sécrétion d'insuline et diabète

Nutrient ingestion triggers a complex hormonal response aimed at stimulating glucose utilization in liver, muscle and adipose tissue to minimize the raise in blood glucose levels. Insulin secretion by pancreatic beta cells plays a major role in this response. Although the beta cell secretory response is mainly controlled by blood glucose levels, gut hormones secreted in response to food intake have an important role in potentiating glucose-stimulated insulin secretion. These gluco-incretin hormones are GLP-1 (glucagon-like peptide-1) and GIP (gluco-dependent insulinotropic polypeptide). Their action on pancreatic beta cells depends on binding to specific G-coupled receptors linked to activation of the adenylyl cyclase pathway. In addition to their effect on insulin secretion both hormones also stimulate insulin production at the transcriptional and translational level and positively regulate beta cell mass. Because the glucose-dependent insulinotropic action of GLP-1 is preserved in type 2 diabetic patients, this peptide is now developed as a novel therapeutic drug for this disease.

Progression rate of self-propelled feeding tubes in critically ill patients.

OBJECTIVE: Gaining postpyloric access in ventilated, sedated ICU patients usually requires time-consuming procedures such as endoscopy. Recently, a feeding tube has been introduced that migrates spontaneously into the jejunum in surgical patients. The study aimed at assessing the rate of migration of this tube in critically ill patients. DESIGN: Prospective descriptive trial. SETTING: Surgical ICU in a tertiary University Hospital. PATIENTS: One hundred and five consecutive surgical ICU patients requiring enteral feeding were enrolled, resulting in 128 feeding-tube placement attempts. METHODS: A self-propelled tube was used and followed up for 3 days: progression was assessed by daily contrast-injected X-ray. Severity of illness was assessed with SAPS II and organ failure assessed with SOFA score. RESULTS: The patients were aged 55+/-19 years (mean+/-SD) with SAPS II score of 45+/-18. Of the 128 tube placement attempts, 12 could not be placed in the stomach; eight were accidentally pulled out while in gastric position due to the necessity to avoid fixation during the progression phase. Among organ failures, respiratory failure predominated, followed by cardiovascular. By day 3, the postpyloric progression rate was 63/128 tubes (49%). There was no association between migration and age, or SAPS II score, but the progression rate was significantly poorer in patients with hemodynamic failure. Use of norepinephrine and morphine were negatively associated with tube progression (P<0.001), while abdominal surgery was not. In ten patients, jejunal tubes were placed by endoscopy. CONCLUSION: Self-propelled feeding tubes progressed from the stomach to the postpyloric position in 49% of patients, reducing the number of endoscopic placements: these tubes may facilitate enteral nutrient delivery in the ICU.

Glucose-dependent insulinotropic polypeptide (GIP) and its receptor (GIPR): cellular localization, lesion-affected expression, and impaired regenerative axonal growth.

Glucose-dependent insulinotropic polypeptide (GIP) was initially described to be rapidly regulated by endocrine cells in response to nutrient ingestion, with stimulatory effects on insulin synthesis and release. Previously, we demonstrated a significant up-regulation of GIP mRNA in the rat subiculum after fornix injury. To gain more insight into the lesion-induced expression of GIP and its receptor (GIPR), expression profiles of the mRNAs were studied after rat sciatic nerve crush injury in 1) affected lumbar dorsal root ganglia (DRG), 2) spinal cord segments, and 3) proximal and distal nerve fragments by means of quantitative RT-PCR. Our results clearly identified lesion-induced as well as tissue type-specific mRNA regulation of GIP and its receptor. Furthermore, comprehensive immunohistochemical stainings not only confirmed and exceeded the previous observation of neuronal GIP expression but also revealed corresponding GIPR expression, implying putative modulatory functions of GIP/GIPR signaling in adult neurons. In complement, we also observed expression of GIP and its receptor in myelinating Schwann cells and oligodendrocytes. Polarized localization of GIPR in the abaxonal Schwann cell membranes, plasma membrane-associated GIPR expression of satellite cells, and ependymal GIPR expression strongly suggests complex cell type-specific functions of GIP and GIPR in the adult nervous system that are presumably mediated by autocrine and paracrine interactions, respectively. Notably, in vivo analyses with GIPR-deficient mice suggest a critical role of GIP/GIPR signal transduction in promoting spontaneous recovery after nerve crush, insofar as traumatic injury of GIPR-deficient mouse sciatic nerve revealed impaired axonal regeneration compared with wild-type mice.

Disruption of GIP/GIPR axis in human adipose tissue is linked to obesity and insulin resistance.

CONTEXT Glucose-dependent insulinotropic peptide (GIP) has a central role in glucose homeostasis through its amplification of insulin secretion; however, its physiological role in adipose tissue is unclear. OBJECTIVE Our objective was to define the function of GIP in human adipose tissue in relation to obesity and insulin resistance. DESIGN GIP receptor (GIPR) expression was analyzed in human sc adipose tissue (SAT) and visceral adipose (VAT) from lean and obese subjects in 3 independent cohorts. GIPR expression was associated with anthropometric and biochemical variables. GIP responsiveness on insulin sensitivity was analyzed in human adipocyte cell lines in normoxic and hypoxic environments as well as in adipose-derived stem cells obtained from lean and obese patients. RESULTS GIPR expression was downregulated in SAT from obese patients and correlated negatively with body mass index, waist circumference, systolic blood pressure, and glucose and triglyceride levels. Furthermore, homeostasis model assessment of insulin resistance, glucose, and G protein-coupled receptor kinase 2 (GRK2) emerged as variables strongly associated with GIPR expression in SAT. Glucose uptake studies and insulin signaling in human adipocytes revealed GIP as an insulin-sensitizer incretin. Immunoprecipitation experiments suggested that GIP promotes the interaction of GRK2 with GIPR and decreases the association of GRK2 to insulin receptor substrate 1. These effects of GIP observed under normoxia were lost in human fat cells cultured in hypoxia. In support of this, GIP increased insulin sensitivity in human adipose-derived stem cells from lean patients. GIP also induced GIPR expression, which was concomitant with a downregulation of the incretin-degrading enzyme dipeptidyl peptidase 4. None of the physiological effects of GIP were detected in human fat cells obtained from an obese environment with reduced levels of GIPR. CONCLUSIONS GIP/GIPR signaling is disrupted in insulin-resistant states, such as obesity, and normalizing this function might represent a potential therapy in the treatment of obesity-associated metabolic disorders.

Evaluation of the speed-oligo direct Mycobacterium tuberculosis assay for molecular detection of mycobacteria in clinical respiratory specimens.

We present the first evaluation of a novel molecular assay, the Speed-oligo Direct Mycobacterium tuberculosis (SO-DMT) assay, which is based on PCR combined with a dipstick for the detection of mycobacteria and the specific identification of M. tuberculosis complex (MTC) in respiratory specimens. A blind evaluation was carried out in two stages: first, under experimental conditions on convenience samples comprising 20 negative specimens, 44 smear- and culture-positive respiratory specimens, and 11 sputa inoculated with various mycobacterium-related organisms; and second, in the routine workflow of 566 fresh respiratory specimens (4.9% acid-fast bacillus [AFB] smear positives, 7.6% MTC positives, and 1.8% nontuberculous mycobacteria [NTM] culture positives) from two Mycobacterium laboratories. SO-DMT assay showed no reactivity in any of the mycobacterium-free specimens or in those with mycobacterium-related organisms. Compared to culture, the sensitivity in the selected smear-positive specimens was 0.91 (0.92 for MTC and 0.90 for NTM), and there was no molecular detection of NTM in a tuberculosis case or vice versa. With respect to culture and clinical data, the sensitivity, specificity, and positive and negative predictive values for the SO-DMT system in routine specimens were 0.76 (0.93 in smear positives [1.0 for MTC and 0.5 for NTM] and 0.56 in smear negatives [0.68 for MTC and 0.16 for NTM]), 0.99, 0.85 (1.00 in smear positives and 0.68 in smear negatives), and 0.97, respectively. Molecular misidentification of NTM cases occurred when testing 2 gastric aspirates from two children with clinically but not microbiologically confirmed lung tuberculosis. The SO-DMT assay appears to be a fast and easy alternative for detecting mycobacteria and differentiating MTC from NTM in smear-positive respiratory specimens.

Prise en charge nutritionnelle préopératoire. [Preoperative nutritional support.]

Undernutrition is an independent factor of postoperative morbidity and mortality The aim of a preoperative nutritional support is to enhance immune muscular and cognitive functions, and to support wound healing This nutritional support (e g dietary management enteral or parenteral nutrition) should be limited to high risk situations with a beneficial effect of nutrition for the patient undernutrition major surgery and elderly Preoperative nutritional support should be scheduled for atleast 7 to 10 days before the surgery During the preoperative period the type and route of an eventual postoperative nutritional assistance should be anticipated In the case of emergency surgery nutritional assessment of the patient should be done as soon as possible before surgery or in the 48 h postoperative period Finally, in elective surgery, preoperative fasting should be limited to 2-3 hours for clear liquids and 6 hours for solids (C) 2010 Published by Elsevier Masson SAS

Combined laparoscopic-endoscopic method using an omental plug for therapy of gastroduodenal ulcer perforation.

BACKGROUND: Laparoscopic techniques have been proposed as an alternative to open surgery for therapy of peptic ulcer perforation. They provide better postoperative comfort and absence of parietal complications, but leakage occurs in 5% of cases. We describe a new method combining laparoscopy and endoluminal endoscopy, designed to ensure complete closure of the perforation. METHODS: Six patients with anterior ulcer perforations (4 duodenal, 2 gastric) underwent a concomitant laparoscopy and endoluminal endoscopy with closure of the orifice by an omental plug attracted into the digestive tract. RESULTS: All perforations were sealed. The mean operating time was 72 minutes. The mean hospital stay was 5.5 days. There was no morbidity and no mortality. At the 30-day evaluation all ulcers but one (due to Helicobacter pylori persistence) were healed. CONCLUSIONS: This method is safe and effective. Its advantages compared with open surgery or laparoscopic patching as well as its cost-effectiveness should be studied in prospective randomized trials.

Chronic potassium depletion increases adrenal progesterone production that is necessary for efficient renal retention of potassium.

Modern dietary habits are characterized by high-sodium and low-potassium intakes, each of which was correlated with a higher risk for hypertension. In this study, we examined whether long-term variations in the intake of sodium and potassium induce lasting changes in the plasma concentration of circulating steroids by developing a mathematical model of steroidogenesis in mice. One finding of this model was that mice increase their plasma progesterone levels specifically in response to potassium depletion. This prediction was confirmed by measurements in both male mice and men. Further investigation showed that progesterone regulates renal potassium handling both in males and females under potassium restriction, independent of its role in reproduction. The increase in progesterone production by male mice was time dependent and correlated with decreased urinary potassium content. The progesterone-dependent ability to efficiently retain potassium was because of an RU486 (a progesterone receptor antagonist)-sensitive stimulation of the colonic hydrogen, potassium-ATPase (known as the non-gastric or hydrogen, potassium-ATPase type 2) in the kidney. Thus, in males, a specific progesterone concentration profile induced by chronic potassium restriction regulates potassium balance.