Adaptive Laboratory Evolution of Probiotics toward Oxidative Stress Using a Microfluidic-Based Platform.

Adaptive laboratory evolution (ALE) can be used to make bacteria less susceptible to oxidative stress. An alternative to large batch scale ALE cultures is to use microfluidic platforms, which are often more economical and more efficient. Microfluidic ALE platforms have shown promise, but many have suffered from subpar cell passaging mechanisms and poor spatial definition. A new approach is presented using a microfluidic Evolution on a Chip (EVoc) design which progressively drives microbial cells from areas of lower H2O2 concentration to areas of higher concentration. Prolonged exposure, up to 72 h, revealed the survival of adaptive strains of Lacticaseibacillus rhamnosus GG, a beneficial probiotic often included in food products. After performing ALE on this microfluidic platform, the bacteria persisted under high H2O2 concentrations in repeated trials. After two progressive exposures, the ability of L. rhamnosus to grow in the presence of H2O2 increased from 1 mm H2O2 after a lag time of 31 h to 1 mm after 21 h, 2 mm after 28 h, and 3 mm after 42 h. The adaptive strains have different morphology, and gene expression compared to wild type, and genome sequencing revealed a potentially meaningful single nucleotide mutation in the protein omega-amidase.

Encapsulation and stabilization of lactoferrin in polyelectrolyte ternary complexes.

Effective delivery of the bioactive protein, lactoferrin (LF), remains a challenge as it is sensitive to environmental changes and easily denatured during heating, restricting its application in functional food products. To overcome these challenges, we formulated novel polyelectrolyte ternary complexes of LF with gelatin (G) and negatively charged polysaccharides, to improve the thermal stability of LF with retained antibacterial activity. Linear, highly charged polysaccharides were able to form interpolymeric complexes with LF and G, while coacervates were formed with branched polysaccharides. A unique multiphase coacervate was observed in the gum Arabic GA-LF-G complex, where a special coacervate-in-coacervate structure was found. The ternary complexes made with GA, soy soluble polysaccharide (SSP), or high methoxyl pectin (HMP) preserved the protein structures and demonstrated enhanced thermal stability of LF. The GA-LF-G complex was especially stable with >90% retention of the native LF after treatment at 90 °C for 2 min in a water bath or at 145 °C for 30 s, while the LF control had only ~ 7% undenatured LF under both conditions. In comparison to untreated LF, LF in ternary complex retained significant antibacterial activity on both Gram-positive and Gram-negative bacteria, even after heat treatment. These ternary complexes of LF maintain the desired functionality of LF, thermal stability and antibacterial activity, in the final products. The ternary complex structure, particularly the multiphase coacervate, may serve as a template for the encapsulation and stabilization of other bioactives and peptides.

Diffusion-Convection Hybrid Microfluidic Platform for Rapid Antibiotic Susceptibility Testing.

Conventional antibiotic susceptibility testing (AST) assays such as broth microdilution and Kirby-Bauer disk diffusion are time-consuming (e.g., 24-72 h) and labor-intensive. Here, we present a microfluidic platform to perform AST assays with a broad range of antibiotic concentrations and controls. A culture medium stream was serially enriched with antibiotics along the length of the platform via diffusion and flow-directing mass convection mechanisms, generating a concentration gradient captured in a series of microchamber duplicates. We observed an agreement between the simulated and experimental concentration gradients and applicability to a variety of different molecules by changing the loading time according to a simple linear equation. The AST assay in our platform is based on bacterial metabolism, indicated by resazurin fluorescence. The small reaction volume enabled a minimum inhibitory concentration (MIC) to be determined in 4-5 h. Proof-of-concept functionality testing, using human isolates and clinically important antibiotics from different classes, indicated a high rate of agreement (94%: MIC within ±1 two-fold dilution of the reference method) of on-chip MICs and conventional broth microdilution. Overall, our results showed that this microfluidic platform is capable of determining antibiotic susceptibility in a rapid and reliable manner.

Continuing Medical Education Questions: July 2021.

Article Title: Nutrient drinking test as biomarker in functional dyspepsia.

Continuing Medical Education Questions: January 2020.

Article Title: Chronic Pancreatitis: Managing a Difficult Disease.

An Interface-Particle Interaction Approach for Evaluation of the Co-Encapsulation Efficiency of Cells in a Flow-Focusing Droplet Generator.

Droplet-based microfluidics offers significant advantages, such as high throughput and scalability, making platforms based on this technology ideal candidates for point-of-care (POC) testing and clinical diagnosis. However, the efficiency of co-encapsulation in droplets is suboptimal, limiting the applicability of such platforms for the biosensing applications. The homogeneity of the bioanalytes in the droplets is an unsolved problem. While there is extensive literature on the experimental setups and active methods used to increase the efficiency of such platforms, passive techniques have received less attention, and their fundamentals have not been fully explored. Here, we develop a novel passive technique for investigating cell encapsulation using the finite element method (FEM). The level set method was used to track the interfaces of forming droplets. The effects of walls and the droplet interfaces on relatively large cells were calculated to track them more accurately during encapsulation. The static surface tension force was used to account for the effects of the interfaces on cells. The results revealed that the pairing efficiency is highly sensitive to the standard deviation (SD) of the distance between the cells in the entrance channel. The pairing efficiency prediction error of our model differed by less than 5% from previous experiments. The proposed model can be used to evaluate the performance of droplet-based microfluidic devices to ensure higher precision for co-encapsulation of cells.

Continuing Medical Education Questions: June 2019.

Article Title: The Efficacy of Split-Dose Bowel Preparations for Polyp Detection: A Systematic Review and Meta-Analysis.

Continuing Medical Education Questions: January 2019.

To receive CME/MOC credit for this activity, please go to: http://acgjournalcme.gi.org/Article Title: Diagnosis and Management of Primary Biliary Cholangitis.

EUS versus magnetic resonance imaging in staging rectal adenocarcinoma: a diagnostic test accuracy meta-analysis.

BACKGROUND AND AIMS: EUS and magnetic resonance imaging (MRI) are both used for locoregional staging of rectal cancer, which determines treatment options. There is a lack of consensus on the best modality for locoregional staging, with studies supporting both EUS and MRI. In this study, we performed the first diagnostic test accuracy meta-analysis to compare the diagnostic accuracy, sensitivity, and specificity of EUS and MRI in the staging of rectal cancer. METHODS: A comprehensive electronic literature search up to June 2018 was performed to identify prospective cohort studies directly comparing the accuracy of EUS with MRI in staging nonmetastatic rectal cancer with surgical pathology as the reference standard. Quality of the included studies was measured by using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) tool. A bivariate hierarchical model was used to perform the meta-analysis of diagnostic test accuracy according to the Cochrane approved methodology. Summary receiver operating characteristics were developed, and the area under the curve was calculated for overall and individual T and N staging, for EUS, MRI, and head-to-head comparison. RESULTS: Six of 2475 studies including 234 patients were eligible. Pooled sensitivity and specificity in T staging were .79 (95% confidence interval [CI], .72-.85) and .89 (95% CI, .84-.93) for EUS and .79 (95% CI, .72-.85) and .85 (95% CI, .79-.90) for MRI, respectively. Pooled sensitivity and specificity in N staging were .81 (95% CI, .71-.89) and .88 (95% CI, .80-.94) for EUS and .83 (95% CI, .73-.90), and .90 (95% CI, .82-.95) for MRI, respectively. In area under the curve head-to-head analysis, EUS was superior to MRI in overall T staging (P < .05). EUS outperformed MRI in overall T, overall N, T1, and T3 staging (P < .01), after excluding studies using an endorectal coil for MRI. MRI was superior to EUS in T2 staging (P = .01) in both analyses. CONCLUSIONS: EUS and MRI both provide reasonable diagnostic accuracy in the staging of nonmetastatic rectal cancer. EUS was superior to MRI in overall T staging and overall T and N staging after adjusting for MRI technology. Practitioners should be aware of advantages and disadvantages of both modalities and choose appropriate methods while considering diagnostic accuracy of each test and institutional practices and limitations.

Endoscopic ultrasound-guided transmural approach versus ERCP-guided transpapillary approach for primary decompression of malignant biliary obstruction: a meta-analysis.

BACKGROUND: Primary decompression in patients with malignant biliary obstruction can be achieved via endoscopic retrograde cholangiopancreatography (ERCP) with transpapillary stenting, or, more recently, via transmural endoscopic ultrasound-guided biliary drainage (EUS-BD). It is unclear whether either approach is superior in terms of clinical success or adverse events in the primary setting. METHODS: A comprehensive systematic electronic search was performed for studies comparing EUS-BD and ERCP as the primary approach with respect to clinical success and any other outcome(s). Pooled relative risks (RRs) and weighted mean differences were obtained as appropriate using DerSimonian and Laird random effects models. Sensitivity analyses were also performed. RESULTS: 5 out of 776 studies with a total of 396 patients were included. Overall clinical success was not significantly different between EUS-BD and ERCP (RR 0.98, 95 % confidence interval [CI] 0.93 to 1.03). There was no significant difference in overall adverse events (RR 0.84, 95 %CI 0.35 to 2.01), though results suggested that EUS-BD may be associated with a reduced risk of pancreatitis (RR 0.22, 95 %CI 0.05 to 1.02). There were no significant differences between EUS-BD and ERCP in terms of procedure time or the risk of stent occlusion. CONCLUSIONS: EUS-BD had similar clinical success rates and occlusion rates to ERCP in the primary decompression of malignant biliary obstruction from meta-analysis including a modest number of patients. EUS-BD may be a practical alternative to the ERCP-guided approach in such patients, but further well-designed prospective studies with larger numbers of patients are required to more clearly delineate potential differences in adverse events and cost.

Non-invasive diagnostic tests for Helicobacter pylori infection.

BACKGROUND: Helicobacter pylori (H pylori) infection has been implicated in a number of malignancies and non-malignant conditions including peptic ulcers, non-ulcer dyspepsia, recurrent peptic ulcer bleeding, unexplained iron deficiency anaemia, idiopathic thrombocytopaenia purpura, and colorectal adenomas. The confirmatory diagnosis of H pylori is by endoscopic biopsy, followed by histopathological examination using haemotoxylin and eosin (H & E) stain or special stains such as Giemsa stain and Warthin-Starry stain. Special stains are more accurate than H & E stain. There is significant uncertainty about the diagnostic accuracy of non-invasive tests for diagnosis of H pylori. OBJECTIVES: To compare the diagnostic accuracy of urea breath test, serology, and stool antigen test, used alone or in combination, for diagnosis of H pylori infection in symptomatic and asymptomatic people, so that eradication therapy for H pylori can be started. SEARCH METHODS: We searched MEDLINE, Embase, the Science Citation Index and the National Institute for Health Research Health Technology Assessment Database on 4 March 2016. We screened references in the included studies to identify additional studies. We also conducted citation searches of relevant studies, most recently on 4 December 2016. We did not restrict studies by language or publication status, or whether data were collected prospectively or retrospectively. SELECTION CRITERIA: We included diagnostic accuracy studies that evaluated at least one of the index tests (urea breath test using isotopes such as 13C or 14C, serology and stool antigen test) against the reference standard (histopathological examination using H & E stain, special stains or immunohistochemical stain) in people suspected of having H pylori infection. DATA COLLECTION AND ANALYSIS: Two review authors independently screened the references to identify relevant studies and independently extracted data. We assessed the methodological quality of studies using the QUADAS-2 tool. We performed meta-analysis by using the hierarchical summary receiver operating characteristic (HSROC) model to estimate and compare SROC curves. Where appropriate, we used bivariate or univariate logistic regression models to estimate summary sensitivities and specificities. MAIN RESULTS: We included 101 studies involving 11,003 participants, of which 5839 participants (53.1%) had H pylori infection. The prevalence of H pylori infection in the studies ranged from 15.2% to 94.7%, with a median prevalence of 53.7% (interquartile range 42.0% to 66.5%). Most of the studies (57%) included participants with dyspepsia and 53 studies excluded participants who recently had proton pump inhibitors or antibiotics.There was at least an unclear risk of bias or unclear applicability concern for each study.Of the 101 studies, 15 compared the accuracy of two index tests and two studies compared the accuracy of three index tests. Thirty-four studies (4242 participants) evaluated serology; 29 studies (2988 participants) evaluated stool antigen test; 34 studies (3139 participants) evaluated urea breath test-13C; 21 studies (1810 participants) evaluated urea breath test-14C; and two studies (127 participants) evaluated urea breath test but did not report the isotope used. The thresholds used to define test positivity and the staining techniques used for histopathological examination (reference standard) varied between studies. Due to sparse data for each threshold reported, it was not possible to identify the best threshold for each test.Using data from 99 studies in an indirect test comparison, there was statistical evidence of a difference in diagnostic accuracy between urea breath test-13C, urea breath test-14C, serology and stool antigen test (P = 0.024). The diagnostic odds ratios for urea breath test-13C, urea breath test-14C, serology, and stool antigen test were 153 (95% confidence interval (CI) 73.7 to 316), 105 (95% CI 74.0 to 150), 47.4 (95% CI 25.5 to 88.1) and 45.1 (95% CI 24.2 to 84.1). The sensitivity (95% CI) estimated at a fixed specificity of 0.90 (median from studies across the four tests), was 0.94 (95% CI 0.89 to 0.97) for urea breath test-13C, 0.92 (95% CI 0.89 to 0.94) for urea breath test-14C, 0.84 (95% CI 0.74 to 0.91) for serology, and 0.83 (95% CI 0.73 to 0.90) for stool antigen test. This implies that on average, given a specificity of 0.90 and prevalence of 53.7% (median specificity and prevalence in the studies), out of 1000 people tested for H pylori infection, there will be 46 false positives (people without H pylori infection who will be diagnosed as having H pylori infection). In this hypothetical cohort, urea breath test-13C, urea breath test-14C, serology, and stool antigen test will give 30 (95% CI 15 to 58), 42 (95% CI 30 to 58), 86 (95% CI 50 to 140), and 89 (95% CI 52 to 146) false negatives respectively (people with H pylori infection for whom the diagnosis of H pylori will be missed).Direct comparisons were based on few head-to-head studies. The ratios of diagnostic odds ratios (DORs) were 0.68 (95% CI 0.12 to 3.70; P = 0.56) for urea breath test-13C versus serology (seven studies), and 0.88 (95% CI 0.14 to 5.56; P = 0.84) for urea breath test-13C versus stool antigen test (seven studies). The 95% CIs of these estimates overlap with those of the ratios of DORs from the indirect comparison. Data were limited or unavailable for meta-analysis of other direct comparisons. AUTHORS' CONCLUSIONS: In people without a history of gastrectomy and those who have not recently had antibiotics or proton ,pump inhibitors, urea breath tests had high diagnostic accuracy while serology and stool antigen tests were less accurate for diagnosis of Helicobacter pylori infection.This is based on an indirect test comparison (with potential for bias due to confounding), as evidence from direct comparisons was limited or unavailable. The thresholds used for these tests were highly variable and we were unable to identify specific thresholds that might be useful in clinical practice.We need further comparative studies of high methodological quality to obtain more reliable evidence of relative accuracy between the tests. Such studies should be conducted prospectively in a representative spectrum of participants and clearly reported to ensure low risk of bias. Most importantly, studies should prespecify and clearly report thresholds used, and should avoid inappropriate exclusions.

Diagnostic accuracy of EUS compared with MRCP in detecting choledocholithiasis: a meta-analysis of diagnostic test accuracy in head-to-head studies.

BACKGROUND AND AIMS: There is a wide range of reported sensitivity and specificity for EUS and MRCP in the diagnosis of choledocholithiasis, with lack of a proper meta-analysis of diagnostic test accuracy by using head-to-head comparison. Here, we aimed to compare the diagnostic accuracy of EUS and MRCP in detecting choledocholithiasis by using appropriate methodology recommended by the Cochrane Collaboration. METHODS: A comprehensive electronic literature search up to January 2017 was done by 2 reviewers for prospective cohort studies comparing EUS and MRCP to a reference standard for detecting choledocholithiasis. The acceptable reference standards were considered ERCP, intraoperative cholangiography, or clinical follow-up >3 months for negative cases. Quality of the included studies was measured by using the QUADAS-2 tool. A bivariate hierarchical model was used to perform the meta-analysis of diagnostic test accuracy. Summary receiver operating characteristics were developed and the area under the curve was calculated. RESULTS: A total of 5 of 32 studies were included. No study presented a high risk of bias. The pooled sensitivity and specificity were 0.97 (range, 0.91-0.99) and 0.90 (range, 0.83-0.94) for EUS and 0.87 (range, 0.80-0.93) and 0.92 (range, 0.87-0.96) for MRCP. The overall diagnostic odds ratio of EUS was significantly higher than the one with MRCP (162.5 vs 79.0, respectively; P = .008). Further analysis showed that this was mainly due to the significantly higher sensitivity of EUS as compared with that of MRCP (P = .006). The specificity was not significantly different between 2 modalities (P = .42). CONCLUSION: Both EUS and MRCP provide good diagnostic accuracy, with EUS providing statically better diagnostic accuracy and sensitivity, with comparable specificity. EUS should be incorporated in the diagnostic algorithm in patients suspected of choledocholithiasis whenever appropriate.

Amylase in drain fluid for the diagnosis of pancreatic leak in post-pancreatic resection.

BACKGROUND: The treatment of people with clinically significant postoperative pancreatic leaks is different from those without clinically significant pancreatic leaks. It is important to know the diagnostic accuracy of drain fluid amylase as a triage test for the detection of clinically significant pancreatic leaks, so that an informed decision can be made as to whether the patient with a suspected pancreatic leak needs further investigations and treatment. There is currently no systematic review of the diagnostic test accuracy of drain fluid amylase for the diagnosis of clinically relevant pancreatic leak. OBJECTIVES: To determine the diagnostic accuracy of amylase in drain fluid at 48 hours or more for the diagnosis of pancreatic leak in people who had undergone pancreatic resection. SEARCH METHODS: We searched MEDLINE, Embase, the Science Citation Index Expanded, and the National Institute for Health Research Health Technology Assessment (NIHR HTA) websites up to 20 February 2017. We searched the references of the included studies to identify additional studies. We did not restrict studies based on language or publication status, or whether data were collected prospectively or retrospectively. We also performed a 'related search' and 'citing reference' search in MEDLINE and Embase. SELECTION CRITERIA: We included all studies that evaluated the diagnostic test accuracy of amylase in the drain fluid at 48 hours or more for the diagnosis of pancreatic leak in people who had undergone pancreatic resection excluding total pancreatectomy. We planned to exclude case-control studies because these studies are prone to bias, but did not find any. At least two authors independently searched and screened the references produced by the search to identify relevant studies. DATA COLLECTION AND ANALYSIS: Two review authors independently extracted data from the included studies. The included studies reported drain fluid amylase on different postoperative days and measured at different cut-off levels, so it was not possible to perform a meta-analysis using the bivariate model as planned. We have reported the sensitivity, specificity, post-test probability of a positive and negative drain fluid amylase along with 95% confidence interval (CI) on each of the different postoperative days and measured at different cut-off levels. MAIN RESULTS: A total of five studies including 868 participants met the inclusion criteria for this review. The five studies included in this review reported the value of drain fluid amylase at different thresholds and different postoperative days. The sensitivities and specificities were variable; the sensitivities ranged between 0.72 and 1.00 while the specificities ranged between 0.73 and 0.99 for different thresholds on different postoperative days. At the median prevalence (pre-test probability) of 15.9%, the post-test probabilities for pancreatic leak ranged between 35.9% and 95.4% for a positive drain fluid amylase test and ranged between 0% and 5.5% for a negative drain fluid amylase test.None of the studies used the reference standard of confirmation by surgery or by a combination of surgery and clinical follow-up, but used the International Study Group on Pancreatic Fistula (ISGPF) grade B and C as the reference standard. The overall methodological quality was unclear or high in all the studies. AUTHORS' CONCLUSIONS: Because of the paucity of data and methodological deficiencies in the studies, we are uncertain whether drain fluid amylase should be used as a method for testing for pancreatic leak in an unselected population after pancreatic resection; and we judge that the optimal cut-off of drain fluid amylase for making the diagnosis of pancreatic leak is also not clear. Further well-designed diagnostic test accuracy studies with pre-specified index test threshold of drain fluid amylase (at three times more on postoperative day 5 or another suitable pre-specified threshold), appropriate follow-up (for at least six to eight weeks to ensure that there are no pancreatic leaks), and clearly defined reference standards (of surgical, clinical, and radiological confirmation of pancreatic leak) are important to reliably determine the diagnostic accuracy of drain fluid amylase in the diagnosis of pancreatic leak.

Diagnostic accuracy of different imaging modalities following computed tomography (CT) scanning for assessing the resectability with curative intent in pancreatic and periampullary cancer.

BACKGROUND: Periampullary cancer includes cancer of the head and neck of the pancreas, cancer of the distal end of the bile duct, cancer of the ampulla of Vater, and cancer of the second part of the duodenum. Surgical resection is the only established potentially curative treatment for pancreatic and periampullary cancer. A considerable proportion of patients undergo unnecessary laparotomy because of underestimation of the extent of the cancer on computed tomography (CT) scanning. Other imaging methods such as magnetic resonance imaging (MRI), positron emission tomography (PET), PET-CT, and endoscopic ultrasound (EUS) have been used to detect local invasion or distant metastases not visualised on CT scanning which could prevent unnecessary laparotomy. No systematic review or meta-analysis has examined the role of different imaging modalities in assessing the resectability with curative intent in patients with pancreatic and periampullary cancer. OBJECTIVES: To determine the diagnostic accuracy of MRI, PET scan, and EUS performed as an add-on test or PET-CT as a replacement test to CT scanning in detecting curative resectability in pancreatic and periampullary cancer. SEARCH METHODS: We searched MEDLINE, Embase, Science Citation Index Expanded, and Health Technology Assessment (HTA) databases up to 5 November 2015. Two review authors independently screened the references and selected the studies for inclusion. We also searched for articles related to the included studies by performing the "related search" function in MEDLINE (OvidSP) and Embase (OvidSP) and a "citing reference" search (by searching the articles that cite the included articles). SELECTION CRITERIA: We included diagnostic accuracy studies of MRI, PET scan, PET-CT, and EUS in patients with potentially resectable pancreatic and periampullary cancer on CT scan. We accepted any criteria of resectability used in the studies. We included studies irrespective of language, publication status, or study design (prospective or retrospective). We excluded case-control studies. DATA COLLECTION AND ANALYSIS: Two review authors independently performed data extraction and quality assessment using the QUADAS-2 (quality assessment of diagnostic accuracy studies - 2) tool. Although we planned to use bivariate methods for analysis of sensitivities and specificities, we were able to fit only the univariate fixed-effect models for both sensitivity and specificity because of the paucity of data. We calculated the probability of unresectability in patients who had a positive index test (post-test probability of unresectability in people with a positive test result) and in those with negative index test (post-test probability of unresectability in people with a positive test result) using the mean probability of unresectability (pre-test probability) from the included studies and the positive and negative likelihood ratios derived from the model. The difference between the pre-test and post-test probabilities gave the overall added value of the index test compared to the standard practice of CT scan staging alone. MAIN RESULTS: Only two studies (34 participants) met the inclusion criteria of this systematic review. Both studies evaluated the diagnostic test accuracy of EUS in assessing the resectability with curative intent in pancreatic cancers. There was low concerns about applicability for most domains in both studies. The overall risk of bias was low in one study and unclear or high in the second study. The mean probability of unresectable disease after CT scan across studies was 60.5% (that is 61 out of 100 patients who had resectable cancer after CT scan had unresectable disease on laparotomy). The summary estimate of sensitivity of EUS for unresectability was 0.87 (95% confidence interval (CI) 0.54 to 0.97) and the summary estimate of specificity for unresectability was 0.80 (95% CI 0.40 to 0.96). The positive likelihood ratio and negative likelihood ratio were 4.3 (95% CI 1.0 to 18.6) and 0.2 (95% CI 0.0 to 0.8) respectively. At the mean pre-test probability of 60.5%, the post-test probability of unresectable disease for people with a positive EUS (EUS indicating unresectability) was 86.9% (95% CI 60.9% to 96.6%) and the post-test probability of unresectable disease for people with a negative EUS (EUS indicating resectability) was 20.0% (5.1% to 53.7%). This means that 13% of people (95% CI 3% to 39%) with positive EUS have potentially resectable cancer and 20% (5% to 53%) of people with negative EUS have unresectable cancer. AUTHORS' CONCLUSIONS: Based on two small studies, there is significant uncertainty in the utility of EUS in people with pancreatic cancer found to have resectable disease on CT scan. No studies have assessed the utility of EUS in people with periampullary cancer.There is no evidence to suggest that it should be performed routinely in people with pancreatic cancer or periampullary cancer found to have resectable disease on CT scan.

Differential Expression of Hox and Notch Genes in Larval and Adult Stages of Echinococcus granulosus.

This investigation aimed to evaluate the differential expression of HoxB7 and notch genes in different developmental stages of Echinococcus granulosus sensu stricto. The expression of HoxB7 gene was observed at all developmental stages. Nevertheless, significant fold differences in the expression level was documented in the juvenile worm with 3 or more proglottids, the germinal layer from infected sheep, and the adult worm from an experimentally infected dog. The notch gene was expressed at all developmental stages of E. granulosus; however, the fold difference was significantly increased at the microcysts in monophasic culture medium and the germinal layer of infected sheep in comparison with other stages. The findings demonstrated that the 2 aforementioned genes evaluated in the present study were differentially expressed at different developmental stages of the parasite and may contribute to some important biological processes of E. granulosus.

Incidence and predictors of post-ERCP pancreatitis in patients with suspected sphincter of Oddi dysfunction undergoing biliary or dual sphincterotomy: results from the EPISOD prospective multicenter randomized sham-controlled study.

BACKGROUND AND STUDY AIM: Pancreatitis following endoscopic retrograde cholangiopancreatography (ERCP) is a significant and potentially life-threatening adverse event and is common in patients with suspected sphincter of Oddi dysfunction (SOD). Here we aimed to identify predictors of the risk in this population. PATIENTS AND METHODS: The Evaluating Predictors and Interventions in SOD (EPISOD) study prospectively enrolled 214 post-cholecystectomy patients with SOD type III in seven US centers. Patients were randomized, using a 2:1 allocation, to sphincterotomy or sham procedure, irrespective of the results of sphincter of Oddi manometry. Patients in the sphincterotomy arm who had elevated pancreatic sphincter pressure were randomized to biliary only or to dual (biliary and pancreatic) sphincterotomy. All but one patient received prophylactic pancreatic stents, but none received pharmacological prophylaxis. Post ERCP pancreatitis (PEP) was defined as acute pancreatitis within the subsequent 7 days. Blinded research coordinators at each site called patients at 1 week post-procedure. RESULTS: PEP occurred in 26 patients, in 10.6 % (15/141) in the sphincterotomy arm and 15.1 % (11/73) in the sham arm; unadjusted relative risk 0.71 (95 % confidence interval [95 %CI] 0.34 - 1.46). PEP rate was not significantly different in patients who received sphincterotomy compared with those undergoing sham treatment. In addition, the proportion was not statistically different in those who received biliary sphincterotomy alone (12/94; 12.8 % [95 %CI 6.0 % - 19.5 %]) compared with dual sphincterotomy (3/47; 6.4 % [95 %CI 0.0 % - 13.4 %]). Multivariate analysis identified an interaction between duration of ERCP and sedation type (P < 0.02). CONCLUSION: The performance of biliary or dual sphincterotomy does not increase the risk of PEP in patients suspected of SOD. However, the high rate of PEP in patients with suspected SOD, despite pancreatic stenting in expert centers, is confirmed in this prospective study. The combined effect of duration of ERCP and sedation type on the development of PEP should be further explored.Clinicaltrials.gov registration: NCT00688662.

Sphincter of Oddi Dysfunction: Updates from the Recent Literature.

Sphincter of Oddi dysfunction (SOD) has long been a controversial topic, starting with whether it even exists, as a sphincterotomy-responsive entity to treat, for either: (1) post-cholecystectomy abdominal pain and/or (2) idiopathic recurrent acute pancreatitis (IRAP). Many of its aspects had required further research to better prove or refute its existence and to provide proper recommendations for physicians to diagnose and treat this condition. Fortunately, there has been major advancement in our knowledge in several areas over the past few years. New studies on challenging the classification, exploring alternative diagnostic methods, and quantifying the role of sphincterotomy in treatment of SOD for post-cholecystectomy pain and for IRAP were recently published, including a randomized trial in each of the two areas. The goal of this paper is to review recent literature on selected important questions and to summarize the results of major trials in this field.

Human Dental Pulp Stem Cells Differentiate into Oligodendrocyte Progenitors Using the Expression of Olig2 Transcription Factor.

The helix-loop-helix transcription factor Olig2 is essential for lineage determination of oligodendrocytes. Differentiation of stem cells into oligodendrocytes and transplanting them is a novel strategy for the repair of different demyelination diseases. Dental pulp stem cells (DPSCs) are of great interest in regenerative medicine due to their potential for repairing damaged tissues. In this study, DPSCs were isolated from human third molars and transfected with the human Olig2 gene as a differentiation inducer for the oligodendrogenic pathway. Following the differentiation procedure, the expression of Sox2, NG2, PDGFRα, Nestin, MBP, Olig2, Oct4, glial fibrillary acidic protein and A2B5 as stage-specific markers was studied by real-time RT-qPCR, immunocytochemistry and Western blot analysis. The cells were transplanted into a mouse model of local sciatic damage by lysolecithin as a model for demyelination. Oligodendrocyte progenitor cells (OPCs) actively remyelinated and recovered the lysolecithin-induced damages in the sciatic nerve as revealed by treadmill exercise, the von Frey filament test and hind paw withdrawal in response to a thermal stimulus. Recovery of behavioral reflexes occurred 2-6 weeks after OPC transplantation. The results demonstrate that the expression of Olig2 in DPSCs reduces the expression of stem cell markers and induces the development of oligodendrocyte progenitors as revealed by the emergence of oligodendrocyte markers. DPSCs could be programmed into oligodendrocyte progenitors and considered as a simple and valuable source for the cell therapy of neurodegenerative diseases.

Isolation of copper oxide (CuO) nanoparticles resistant Pseudomonas strains from soil and investigation on possible mechanism for resistance.

The present study deals with isolation and characterization of copper oxide nanoparticles resistant Pseudomonas strains that were isolated from the soil collected from mining and refining sites of Sarcheshmeh copper mine in the Kerman Province of Iran. The three isolates were selected based on high level of copper oxide nanoparticles (CuO NPs) resistance. The isolates were authentically identified as Pseudomonas fluorescens CuO-1, Pseudomonas fluorescens CuO-2 and Pseudomonas sp. CuO-3 by morphological, biochemical and 16S rDNA gene sequencing analysis. The growth pattern of these isolates with all the studied CuO NPs concentrations was similar to that of control (without CuO NPs) indicating that CuO NPs would not affect the growth of isolated strains. A reduction in the amount of exopolysaccharides was observed after CuO NPs-P. fluorescens CuO-1 culture supernatant interaction. The Fourier transform infrared spectroscopy (FT-IR) peaks for the exopolysaccharides extracted from the bacterial culture supernatant and the interacted CuO NPs were almost similar. The exopolysaccharide capping of the CuO NPs was confirmed by FT-IR and X-ray diffraction analysis. The study of bacterial exopolysaccharides capped CuO NPs with E. coli PTCC 1338 and S. aureus PTCC 1113 showed less toxicity compared to uncoated CuO NPs. Our study suggests that the capping of nanoparticles by bacterially produced exopolysaccharides serve as the probable mechanism of tolerance.

Association of rs4516035 Polymorphism with Osteoporosis in the Southeastern Iranian Population: A Case-Control Study.

BACKGROUND: Genetic polymorphisms are known to play a crucial role in the development of osteoporosis. Vitamin D3 regulates bone homeostasis through the vitamin D receptor (VDR). Reduced VDR activity increases osteoporosis risk. Study Design: A case-control study. METHODS: This case-control study investigated the potential association between six single-nucleotide polymorphisms (SNPs) within the VDR gene (rs11568820, rs4516035, rs2228570, rs1544410, rs7975232, and rs731236) and the occurrence of osteoporosis in Kerman province. The genotypes of the SNPs were analyzed using polymerase chain reaction-restriction fragment length polymorphism, tetra primer amplification refractory mutation system-PCR, and sequencing in two groups of osteoporosis patients (n=40) and controls (n=42). Additionally, the levels of calcium and vitamin D3 in the serum of the patients were measured, and the in silico analysis of the VDR structure and interaction was performed using I-TASSER, ProSA, PROCHECK, GeneMANIA, GTEx, and GPS 6.0. RESULTS: None of the patients exhibited calcium or vitamin D3 deficiencies. Among the six SNPs, only the T allele in rs4516035, which leads to a shorter variant called VDRA, showed a significant association with susceptibility to osteoporosis (odds ratio=3.061, P=0.007). The in silico analysis demonstrated that the 3D structure, expression, and post-transcriptional modification of VDRA are distinct from those of the more extended variant, VDRB1. VDRB1 is upregulated in sun-exposed skin, and its interactions with its partners differ from those of VDRA. CONCLUSION: Despite adequate vitamin D levels, the VDRA variant, which has lower activity, could increase the predisposition to osteoporosis in the studied population. These findings clarify the importance of genetic screening for personalized medicine and the effectiveness of prevention and treatment strategies.