Endoscopic Ultrasound-guided Transluminal Gallbladder Drainage in Patients With Acute Cholecystitis: A Prospective Multicenter Trial.

OBJECTIVE: To evaluate the safety and efficacy of endoscopic ultrasound-guided gallbladder drainage (EUS-GBD) using a lumen-apposing metal stent (LAMS). BACKGROUND: For patients with acute cholecystitis who are poor surgical candidates, EUS-GBD using a LAMS is an important treatment alternative to percutaneous gallbladder drainage. METHODS: We conducted a regulatory-compliant, prospective multicenter trial at 7 tertiary referral centers in the United States of America and Belgium. Thirty consecutive patients with mild or moderate acute cholecystitis who were not candidates for cholecystectomy were enrolled between September 2019 and August 2021. Eligible patients had a LAMS placed transmurally with 30 to 60-day indwell if removal was clinically indicated, and 30-day follow-up post-LAMS removal. Endpoints included days until acute cholecystitis resolution, reintervention rate, acute cholecystitis recurrence rate, and procedure-related adverse events (AEs). RESULTS: Technical success was 93.3% (28/30) for LAMS placement and 100% for LAMS removal in 19 patients for whom removal was attempted. Five (16.7%) patients required reintervention. Mean time to acute cholecystitis resolution was 1.6±1.5 days. Acute cholecystitis symptoms recurred in 10.0% (3/30) after LAMS removal. Five (16.7%) patients died from unrelated causes. Procedure-related AEs were reported to the FDA in 30.0% (9/30) of patients, including one fatal event 21 days after LAMS removal; however, no AEs were causally related to the LAMS. CONCLUSIONS: For selected patients with acute cholecystitis who are at elevated surgical risk, EUS-GBD with LAMS is an alternative to percutaneous gallbladder drainage. It has high technical and clinical success, with low recurrence and an acceptable AE rate. Clinicaltrials.gov, Number: NCT03767881.

Current landscape of therapeutic EUS: Changing paradigms in gastroenterology practice.

Therapeutic EUS has witnessed exponential growth in the last decade, but it has been considered investigational until recently. An increasing body of good-quality evidence is now demonstrating clear advantages over established alternatives, adding therapeutic EUS to management algorithms of complex hepato-pancreato-biliary (HPB) and gastrointestinal (GI) conditions. In this review, the available evidence and clinical role of therapeutic EUS in established and evolving applications will be discussed. A Graphical Summary for each scenario will provide (1) technical steps, (2) anatomical sketch, (3) best-supporting evidence, and (4) role in changing current and future GI practice. Therapeutic EUS has accepted well-established applications such as drainage of symptomatic peripancreatic fluid collections, biliary drainage in failed endoscopic retrograde cholangiopancreatography, and treatment of acute cholecystitis in unfit-for-surgery patients. In addition, good-quality evidence on several emerging indications (e.g., treatment of gastric outlet obstruction, local ablation of pancreatic solid lesions, etc.) is promising. Specific emphasis will be given to how these technical innovations have changed management paradigms and algorithms and expanded the possibilities of gastroenterologists to provide therapeutic solutions to old and emerging clinical needs. Therapeutic EUS is cementing its role in everyday practice, radically changing the treatment of different HPB diseases and other conditions (e.g., GI obstruction). The development of dedicated accessories and increased training opportunities will expand the ability of gastroenterologists to deliver highly effective yet minimally invasive therapies, potentially translating into a better quality of life, especially for oncological and fragile patients.

Endoscopic ultrasound-guided gastroenterostomy versus duodenal stenting for malignant gastric outlet obstruction: an international, multicenter, propensity score-matched comparison.

BACKGROUND: Endoscopic duodenal stenting is the current standard treatment for malignant gastric outlet obstruction (GOO) in patients with limited life expectancy. However, duodenal stenting is prone to stent dysfunction. Endoscopic ultrasound-guided gastroenterostomy (EUS-GE) is a novel technique with potentially superior stent patency. We compared clinical success, safety, and stent dysfunction of EUS-GE and duodenal stenting in patients with malignant GOO using propensity score matching. METHODS: This international, multicenter, retrospective study analyzed consecutive patients undergoing EUS-GE or duodenal stenting for GOO between 2015 and 2021 in three European centers. Primary outcomes were clinical success (GOO scoring system [GOOSS] ≥ 2) and stent dysfunction (GOOSS ≤ 1 after initial clinical success). A propensity score matching (1:1) analysis was performed using age, sex, underlying disease, disease stage, ascites, and peritoneal carcinomatosis as variables. RESULTS: 214 patients underwent EUS-GE (n = 107) or duodenal stenting (n = 107). After propensity score matching, 176 patients were matched and compared. Technical success rates for EUS-GE and duodenal stenting were 94 % (95 %CI 89 %-99 %) vs. 98 % (95 %CI 95 %-100 %), respectively (P = 0.44). Clinical success rates were 91 % (95 %CI 85 %-97 %) vs. 75 % (95 %CI 66 %-84 %; P = 0.008). Stent dysfunction occurred in 1 % (95 %CI 0-4 %) vs. 26 % (95 %CI 15 %-37 %) of patients (P < 0.001). Adverse event rate was 10 % (95 %CI 4 %-17 %) vs. 21 % (95 %CI 12 %-29 %; P = 0.09). CONCLUSION: EUS-GE had higher clinical success and lower stent dysfunction, with similar safety, compared with duodenal stenting, suggesting that EUS-GE may be preferred over duodenal stenting in patients with malignant GOO.

Therapeutic endoscopic ultrasound: European Society of Gastrointestinal Endoscopy (ESGE) Technical Review.

1: ESGE recommends a prolonged course of a prophylactic broad-spectrum antibiotic in patients with ascites who are undergoing therapeutic endoscopic ultrasound (EUS) procedures.Strong recommendation, low quality evidence. 2: ESGE recommends placement of partially or fully covered self-expandable metal stents during EUS-guided hepaticogastrostomy for biliary drainage in malignant disease.Strong recommendation, moderate quality evidence. 3: ESGE recommends EUS-guided pancreatic duct (PD) drainage should only be performed in high volume expert centers, owing to the complexity of this technique and the high risk of adverse events.Strong recommendation, low quality evidence. 4: ESGE recommends a stepwise approach to EUS-guided PD drainage in patients with favorable anatomy, starting with rendezvous-assisted endoscopic retrograde pancreatography (RV-ERP), followed by antegrade or transmural drainage only when RV-ERP fails or is not feasible.Strong recommendation, low quality evidence. 5: ESGE suggests performing transduodenal EUS-guided gallbladder drainage with a lumen-apposing metal stent (LAMS), rather than using the transgastric route, as this may reduce the risk of stent dysfunction.Weak recommendation, low quality evidence. 6: ESGE recommends using saline instillation for small-bowel distension during EUS-guided gastroenterostomy.Strong recommendation, low quality evidence. 7: ESGE recommends the use of saline instillation with a 19G needle and an electrocautery-enhanced LAMS for EUS-directed transgastric endoscopic retrograde cholangiopancreatography (EDGE) procedures.Strong recommendation, low quality evidence. 8: ESGE recommends the use of either 15- or 20-mm LAMSs for EDGE, with a preference for 20-mm LAMSs when considering a same-session ERCP.Strong recommendation, low quality evidence.

Therapeutic endoscopic ultrasound: European Society of Gastrointestinal Endoscopy (ESGE) Guideline.

1: ESGE recommends the use of endoscopic ultrasound-guided biliary drainage (EUS-BD) over percutaneous transhepatic biliary drainage (PTBD) after failed endoscopic retrograde cholangiopancreatography (ERCP) in malignant distal biliary obstruction when local expertise is available.Strong recommendation, moderate quality evidence. 2: ESGE suggests EUS-BD with hepaticogastrostomy only for malignant inoperable hilar biliary obstruction with a dilated left hepatic duct when inadequately drained by ERCP and/or PTBD in high volume expert centers.Weak recommendation, moderate quality evidence. 3: ESGE recommends that EUS-guided pancreatic duct (PD) drainage should only be considered in symptomatic patients with an obstructed PD when retrograde endoscopic intervention fails or is not possible.Strong recommendation, low quality evidence. 4: ESGE recommends rendezvous EUS techniques over transmural PD drainage in patients with favorable anatomy owing to its lower rate of adverse events.Strong recommendation, low quality evidence. 5: ESGE recommends that, in patients at high surgical risk, EUS-guided gallbladder drainage (GBD) should be favored over percutaneous gallbladder drainage where both techniques are available, owing to the lower rates of adverse events and need for re-interventions in EUS-GBD.Strong recommendation, high quality of evidence. 6: ESGE recommends EUS-guided gastroenterostomy (EUS-GE), in an expert setting, for malignant gastric outlet obstruction, as an alternative to enteral stenting or surgery.Strong recommendation, low quality evidence. 7: ESGE recommends that EUS-GE may be considered in the management of afferent loop syndrome, especially in the setting of malignancy or in poor surgical candidates. Strong recommendation, low quality evidence. 8: ESGE suggests that endoscopic ultrasound-directed transgastric ERCP (EDGE) can be offered, in expert centers, to patients with a Roux-en-Y gastric bypass following multidisciplinary decision-making, with the aim of overcoming the invasiveness of laparoscopy-assisted ERCP and the limitations of enteroscopy-assisted ERCP.Weak recommendation, low quality evidence.

Laparoscopic versus EUS-guided gastroenterostomy for gastric outlet obstruction: an international multicenter propensity score-matched comparison (with video).

BACKGROUND AND AIMS: In the management of gastric outlet obstruction (GOO), EUS-guided gastroenterostomy (EUS-GE) seems to be safe and more effective than enteral stent placement. However, comparisons with laparoscopic GE (L-GE) are scarce. Our aim was to perform a propensity score-matched comparison between EUS-GE and L-GE. METHODS: An international, multicenter, retrospective analysis was performed of consecutive EUS-GE and L-GE procedures in 3 academic centers (January 2015 to May 2020) using propensity score matching to minimize selection bias. A standard maximum propensity score difference of .1 was applied, also considering underlying disease and oncologic staging. RESULTS: Overall, 77 patients were treated with EUS-GE and 48 patients with L-GE. By means of propensity score matching, 37 patients were allocated to both groups, resulting in 74 (1:1) matched patients. Technical success was achieved in 35 of 37 EUS-GE-treated patients (94.6%) versus 100% in the L-GE group (P = .493). Clinical success, defined as eating without vomiting or GOO Scoring System ≥2, was achieved in 97.1% and 89.2%, respectively (P = .358). Median time to oral intake (1 [interquartile range {IQR}, .3-1.0] vs 3 [IQR, 1.0-5.0] days, P < .001) and median hospital stay (4 [IQR, 2-8] vs 8 [IQR, 5.5-20] days, P < .001) were significantly shorter in the EUS-GE group. Overall (2.7% vs 27.0%, P = .007) and severe (.0% vs 16.2%, P = .025) adverse events were identified more frequently in the L-GE group. CONCLUSIONS: For patients with GOO, EUS-GE and L-GE showed almost identical technical and clinical success. However, reduced time to oral intake, shorter median hospital stay, and lower rate of adverse events suggest that the EUS-guided approach might be preferable.

A biodegradable non-covered self-expandable stent to treat pancreatic duct strictures in chronic pancreatitis: a proof of principle.

BACKGROUND AND AIMS: In chronic pancreatitis (CP), fibrotic pancreatic duct (PD) strictures pose a therapeutic challenge, because endoscopic dilatation requires multiple procedures with suboptimal results. Biodegradable self-expandable stents (BD-SESs) may serve as an alternative in this setting. METHODS: Patients with CP were eligible for this proof-of-principle study if at least 6 months of endoscopic dilatation with plastic stents had failed to resolve their PD stricture. The non-covered BD-SESs were expected to degrade within 3 to 6 months. Patients were followed at 3-monthly intervals for 1 year. Placement success and safety were the primary outcome parameters. Stricture resolution was assessed by ERCP after 6 months. RESULTS: BD-SESs were successfully placed in all 19 patients without adverse events. In 2 cases, stent occlusion with sludge and stones was treated by a balloon swipe. One stent disintegrated during this procedure, after which placement of the plastic stent was resumed. A hyperplastic response was observed in 2 patients but did not result in functional obstruction. Stricture resolution was accomplished in 11 patients (technical success rate 58%). Six patients required further treatment of their PD stricture, 4 endoscopically and 2 surgically. Three additional patients underwent surgery for other reasons: 2 Whipple procedures for CP-related adverse events and one tail resection for an intraductal papillary mucinous neoplasm. The remaining 10 patients did not require further PD drainage (clinical success rate 52%). CONCLUSIONS: These preliminary results show that BD-SESs are safe to use and able to resolve fibrotic PD strictures in CP. These encouraging outcomes warrant further testing.

Successful application of endoscopic ultrasound-guided fine needle biopsy to establish pancreatic patient-derived tumor xenografts: a pilot study.

Background and study aim: Typically, pancreatic patient-derived tumor xenografts (PDXs) are established by transplanting large tumor biopsies obtained through invasive surgery approaches into immunocompromised mice. We aimed to develop pancreatic PDXs by transplanting tumor tissue acquired by endoscopic ultrasound (EUS)-guided fine needle biopsies (FNB), assess take rates compared to surgery-derived PDXs, and demonstrate the histological and genetic resemblance to the original tumor. Patients and methods: Biopsies of untreated pancreatic carcinoma were collected at surgery and during EUS and processed to generate PDXs. Results: By centrifugation of FNB-derived tissue prior to engraftment, we achieved an engraftment rate of 60 % (6/10). Despite a decrease in stromal tissue, the general morphology of FNB-derived PDXs was conserved as assessed by histopathology. At the genetic level, somatic mutation and copy number profiles were largely similar to the primary tumor. Conclusion: We show that it is technically feasible to establish pancreatic PDXs using a minimally invasive sampling technique, such as EUS-FNB. Although only a limited amount of tumor tissue was acquired, we obtained results similar to those from surgery-derived PDXs.

CD14(+) macrophages that accumulate in the colon of African AIDS patients express pro-inflammatory cytokines and are responsive to lipopolysaccharide.

BACKGROUND: Intestinal macrophages are key regulators of inflammatory responses to the gut microbiome and play a central role in maintaining tissue homeostasis and epithelial integrity. However, little is known about the role of these cells in HIV infection, a disease fuelled by intestinal inflammation, a loss of epithelial barrier function and increased microbial translocation (MT). METHODS: Phenotypic and functional characterization of intestinal macrophages was performed for 23 African AIDS patients with chronic diarrhea and/or weight loss and 11 HIV-negative Africans with and without inflammatory bowel disease (IBD). AIDS patients were treated with cotrimoxazole for the prevention of opportunistic infections (OIs). Macrophage phenotype was assessed by flow cytometry and immuno-histochemistry (IHC); production of proinflammatory mediators by IHC and Qiagen PCR Arrays; in vitro secretion of cytokines by the Bio-Plex Suspension Array System. Statistical analyses were performed using Spearman's correlation and Wilcoxon matched-pair tests. Results between groups were analyzed using the Kruskal-Wallis with Dunn's post-test and the Mann-Whitney U tests. RESULTS: None of the study participants had evidence of enteric co-infections as assessed by stool analysis and histology. Compared to healthy HIV-negative controls, the colon of AIDS patients was highly inflamed with increased infiltration of inflammatory cells and increased mRNA expression of proinflammatory cytokine (tumour necrosis factor (TNF)-α, interleukin (IL)-1ß, IFN-γ, and IL-18), chemokines (chemokine (C-C motif) ligand (CCL)2 and chemokine (C-X-C) motif ligand (CXCL)10) and transcription factors (TNF receptor-associated factor (TRAF)6 and T-box (TXB)21). IHC revealed significant co-localization of TNF-α and IL-1ß with CD68(+) cells. As in IBD, HIV was associated with a marked increase in macrophages expressing innate response receptors including CD14, the co-receptor for lipopolysaccharide (LPS). The frequency of CD14(+) macrophages correlated positively with plasma LPS, a marker of MT. Total unfractionated mucosal mononuclear cells (MMC) isolated from the colon of AIDS patients, but not MMC depleted of CD14(+) cells, secreted increased levels of proinflammatory cytokines ex vivo in response to LPS. CONCLUSIONS: Intestinal macrophages, in the absence of overt OIs, play an important role in driving persistent inflammation in HIV patients with late-stage disease and diarrhea. These results suggest intensified treatment strategies that target inflammatory processes in intestinal macrophages may be highly beneficial in restoring the epithelial barrier and limiting MT in HIV-infected patients.

Polymerase chain reaction amplifying mycobacterial DNA from aspirates obtained by endoscopic ultrasound allows accurate diagnosis of mycobacterial disease in HIV-positive patients with abdominal lymphadenopathy.

Abdominal lymphadenopathy in human immunodeficiency virus (HIV) infection remains a diagnostic challenge. We performed a prospective cohort study by recruiting 31 symptomatic HIV + patients with abdominal lymphadenopathy and assessing the diagnostic yield of endoscopic ultrasound fine-needle aspiration (EUS-FNA). Mean age was 38 years; 52% were female; and mean CD4 count and viral load were 124 cells/µL and 4 log, respectively. EUS confirmed additional mediastinal nodes in 26%. The porta hepatis was the most common abdominal site. Aspirates obtained by EUS-FNA were subjected to cytology, culture and polymerase chain reaction (PCR) analysis. Mycobacterial infections were confirmed in 67.7%, and 31% had reactive lymphadenopathy. Cytology and culture had low sensitivity, whereas PCR identified 90% of mycobacterial infections. By combining the appearance of aspirates obtained by EUS-FNA and cytologic specimens, we developed a diagnostic algorithm to indicate when analysis with PCR would be useful. PCR performed on material obtained by EUS-FNA was highly accurate in confirming mycobacterial disease and determining genotypic drug resistance.

Impaired CD4+ T-cell restoration in the small versus large intestine of HIV-1-positive South Africans receiving combination antiretroviral therapy.

BACKGROUND: Human immunodeficiency virus type 1 (HIV-1) infection is associated with a massive depletion of intestinal CD4(+) T cells that is only partially reversed by combination antiretroviral therapy (cART). Here, we assessed the ability of nucleoside reverse-transcriptase inhibitor/nonnucleoside reverse-transcriptase inhibitor treatment to restore the CD4(+) T-cell populations in the intestine of South African patients with AIDS. METHODS: Thirty-eight patients with advanced HIV-1 infection who had chronic diarrhea (duration, >4 weeks) and/or unintentional weight loss (>10% decrease from baseline) of uncertain etiology were enrolled. Blood specimens were collected monthly, and gastrointestinal tract biopsy specimens were collected before cART initiation (from the duodenum, jejunum, ileum, and colon), 3 months after cART initiation (from the duodenum), and 6 months after cART initiation (from the duodenum and colon). CD4(+), CD8(+), and CD38(+)CD8(+) T cells were quantified by flow cytometry and immunohistochemistry analyses, and the HIV-1 RNA load was determined by the Nuclisens assay. RESULTS: CD4(+) T-cell and HIV-1 RNA levels were significantly lower, whereas CD8(+) T-cell levels, including activated CD38(+)CD8(+) T cell levels, were higher in the duodenum and jejunum, compared with the colon. After 6 months of cART, a significant but incomplete recovery of CD4(+) T cells was detected in the colon and peripheral blood but not in the duodenum. Failed restoration of the CD4(+) T-cell count in the duodenum was associated with nonspecific enteritis and CD8(+) T-cell activation. CONCLUSIONS: Strategies that target inflammation and immune activation in the small intestine may be required to expedite CD4(+) T-cell recovery and improve therapeutic outcomes.

Activated intestinal macrophages in patients with cirrhosis release NO and IL-6 that may disrupt intestinal barrier function.

BACKGROUND & AIMS: Bacterial infections commonly occur in decompensated cirrhosis resulting from bacterial translocation from the intestine. We studied the role of intestinal macrophages and the epithelial barrier in cirrhosis. METHODS: Forty-four patients with NASH/ASH cirrhosis (decompensated n=29, compensated n=15) and nineteen controls undergoing endoscopy were recruited. Serum was obtained and LPS and LBP levels determined. Intestinal macrophages were characterized by flow cytometry, immunohistochemistry, and nitric oxide (NO) production measured in supernatant of cultured duodenal samples. Quantitative RT-PCR was performed on duodenal biopsies assessing 84 inflammatory genes. Protein levels of cytokines/chemokines were assessed in serum and supernatant. The duodenal wall was assessed by electron microscopy, tight junction protein expression determined by RT-PCR, immunohistochemistry, and Western blot and, functional analysis performed by transepithelial resistance measurement and permeability studies. RESULTS: Increased plasma LPS, LBP levels and higher numbers of duodenal CD33(+)/CD14(+)/Trem-1(+) macrophages, synthesizing iNOS and secreting NO were present in decompensated cirrhosis. Upregulation of IL-8, CCL2, CCL13 at the transcriptional level, and increased IL-8, and IL-6 were detected in supernatant and serum in cirrhosis. IL-6 and IL-8 co-localised with iNOS(+) and CD68(+), but not with CD11c(+) cells. Electron microscopy demonstrated an intact epithelial barrier. Increased Claudin-2 was detected by Western blot and immunohistochemistry, while decreased transepithelial resistance and increased duodenal permeability were detected in decompensated cirrhosis. CONCLUSIONS: Our study shows the presence of activated CD14(+)Trem-1(+)iNOS(+) intestinal macrophages, releasing IL-6, NO, and increased intestinal permeability in patients with cirrhosis, suggesting that these cells may produce factors capable of enhancing permeability to bacterial products.

Gastric cancers of Western European and African patients show different patterns of genomic instability.

BACKGROUND: Infection with H. pylori is important in the etiology of gastric cancer. Gastric cancer is infrequent in Africa, despite high frequencies of H. pylori infection, referred to as the African enigma. Variation in environmental and host factors influencing gastric cancer risk between different populations have been reported but little is known about the biological differences between gastric cancers from different geographic locations. We aim to study genomic instability patterns of gastric cancers obtained from patients from United Kingdom (UK) and South Africa (SA), in an attempt to support the African enigma hypothesis at the biological level. METHODS: DNA was isolated from 67 gastric adenocarcinomas, 33 UK patients, 9 Caucasian SA patients and 25 native SA patients. Microsatellite instability and chromosomal instability were analyzed by PCR and microarray comparative genomic hybridization, respectively. Data was analyzed by supervised univariate and multivariate analyses as well as unsupervised hierarchical cluster analysis. RESULTS: Tumors from Caucasian and native SA patients showed significantly more microsatellite instable tumors (p < 0.05). For the microsatellite stable tumors, geographical origin of the patients correlated with cluster membership, derived from unsupervised hierarchical cluster analysis (p = 0.001). Several chromosomal alterations showed significantly different frequencies in tumors from UK patients and native SA patients, but not between UK and Caucasian SA patients and between native and Caucasian SA patients. CONCLUSIONS: Gastric cancers from SA and UK patients show differences in genetic instability patterns, indicating possible different biological mechanisms in patients from different geographical origin. This is of future clinical relevance for stratification of gastric cancer therapy.

Increased osteoclast formation and activity by peripheral blood mononuclear cells in chronic liver disease patients with osteopenia.

UNLABELLED: Osteoporosis is a common complication of chronic liver disease, and the underlying mechanisms are not understood. We aimed to determine if osteoclasts develop from osteoclast precursors in peripheral blood mononuclear cells (PBMCs) of chronic liver disease patients with osteopenia compared with controls. PBMCs were isolated and fluorescence-activated cell sorting was performed to quantify the activated T lymphocyte population and receptor activator of nuclear factor kappabeta ligand (RANKL) expression. The activated T lymphocyte populations were comparable for all 3 groups, and RANKL was not detectable. The percentage of CD14+CD11b+ cells containing osteoclast precursors was comparable between the 3 groups. To assess the formation and functional activity of osteoclasts formed from circulating mononuclear cells, PBMCs were cultured (1) without addition of cytokines, (2) with macrophage colony-stimulating factor (M-CSF), (3) with M-CSF and osteoprotegerin, and (4) with M-CSF and RANKL. The number of tartrate-resistant acid phosphatase-positive multinucleated cells and bone resorption was assessed. PBMCs from chronic liver disease patients with osteopenia formed more osteoclast-like cells, which, when cultured in the presence of M-CSF and RANKL resorbed more bone than controls. The number of osteoclast-like cells and the amount of bone resorption correlated with lumbar bone densities. Addition of M-CSF increased numbers of osteoclast-like cells formed in healthy controls; however, this was not observed in either of the chronic liver disease groups. Plasma levels of M-CSF were elevated in both patient groups compared with healthy controls. CONCLUSION: Circulating mononuclear cells from chronic liver disease patients with osteopenia have a higher capacity to become osteoclasts than healthy controls or chronic liver disease patients without osteopenia. This could partially be due to priming with higher levels of M-CSF in the circulation.

A population genetics pedigree perspective on the transmission of Helicobacter pylori.

The inference of transmission pathways for medicinally important bacteria is important to our understanding of pathogens. Here we report analyses of transmission in Helicobacter pylori, a major carcinogen. Our study is novel in that the focal community comprises detailed family pedigrees and has a high prevalence of H. pylori. To infer transmission, we performed high-resolution analyses of nucleotide sequences for three genes and accounted for the occurrence of mutation and recombination through the use of simulation modeling. Our results demonstrate that transmission has a strong nonfamilial component potentially the result of a large proportion of infections derived from the community. These results are interesting from both a medical and an evolutionary standpoint. First, efficient control measures and beliefs about the sources of H. pylori infection should be reevaluated. Evolutionarily, our results contradict the hypothesis of strict vertical transmission, presented as an explanation for the strong correlation between human population history and H. pylori diversity. Thus the paradox of persistent phylogenetic structure, despite a permissive mode of transmission and high recombination rates, must be solved elsewhere. Here we consider the potential for recombination events to maintain genetic structure in light of horizontal transmission.

Effect of rapamycin on hepatic osteodystrophy in rats with portasystemic shunting.

AIM: To study if T-cell activation related to portasystemic shunting causes osteoclast-mediated bone loss through RANKL-dependent pathways. We also investigated if T-cell inhibition using rapamycin would protect against bone loss in rats. METHODS: Portasystemic shunting was performed in male Sprague-Dawley rats and rapamycin 0.1 mg/kg was administered for 15 wk by gavage. Rats received powderized chow and supplemental feeds to prevent the effects of malnutrition on bone composition. Weight gain and growth was restored after surgery in shunted animals. At termination, biochemical parameters of bone turnover and quantitative bone histology were assessed. Markers of T-cell activation, inflammatory cytokine production, and RANKL-dependent pathways were measured. In addition, the roles of IGF-1 and hypogonadism were investigated. RESULTS: Portasystemic shunting caused low turnover osteoporosis that was RANKL independent. Bone resorbing cytokine levels, including IL-1, IL-6 and TNFalpha, were not increased in serum and TNFalpha and RANKL expression were not upregulated in PBMC. Portasystemic shunting increased the circulating CD8+ T-cell population. Rapamycin decreased the circulating CD8+ T-cell population, increased CD8+ CD25+ T-regulatory cell population and improved all parameters of bone turnover. CONCLUSION: Osteoporosis caused by portasystemic shunting may be partially ameliorated by rapamycin in the rat model of hepatic osteodystrophy.

Incidence of Helicobacter felis and the effect of coinfection with Helicobacter pylori on the gastric mucosa in the African population.

Helicobacter pylori and Helicobacter felis are two of the Helicobacter spp. that infect humans. H. pylori has been linked to significant gastric pathology. Coinfection with Helicobacter spp. may influence infectious burden, pathogenesis, and antibiotic resistance; however, this has not been studied. The aims of this study were to identify the incidence of H. felis and to analyze the effects of coinfection with both organisms on gastric pathology in a well-characterized South African population. Biopsy samples from the gastric corpora and antra of volunteers (n = 90) were subjected to histological examination and PCR for the identification of H. pylori and H. felis. We further investigated the effect of global strain type on the occurrence of precursor lesions by assigning nucleotide sequences derived from PCR amplification of three genes to global groupings (ancestral Africa1, ancestral Africa2, ancestral Europe, ancestral Asia, and mixed). H. pylori was detected in 75 (83.3%), H. felis in 23 (25.6%), and coinfection in 21 (23.3%) of the volunteers by PCR. H. felis was randomly distributed among adults and children but clustered within families, suggesting intrafamilial transmission. Analysis of histopathology scores revealed no differences in atrophy, activity, and helicobacter density between H. felis-positive and H. felis-negative volunteers. H. pylori substrains common to southern Africa showed no differences in inflammation or atrophy scores. The incidences of H. felis and coinfection with H. pylori in the African population are high. H. felis infection, however, does not influence specific gastric pathology in this population.

Absence of Helicobacter pylori within the oral cavities of members of a healthy South African community.

Our study aimed to evaluate the oral cavity as a reservoir from where Helicobacter pylori may be transmitted. Histology and PCR amplification were performed. Eighty-four percent of the stomach biopsies tested positive; however, H. pylori was not detected in dental samples, indicating the absence of H. pylori within the oral cavity.