Colon cancer-associated B2 Escherichia coli colonize gut mucosa and promote cell proliferation

AIM:To provide further insight into the characterization of mucosa-associated Escherichia coli(E.coli)isolated from the colonic mucosa of cancer patients.METHODS:Phylogroups and the presence of cyclomodulin-encoding genes of mucosa-associated E.coli from colon cancer and diverticulosis specimens weredetermined by PCR.Adhesion and invasion experiments were performed with I-407 intestinal epithelial cells using gentamicin protection assay.Carcinoembryonic antigen-related cell adhesion molecule 6(CEACAM6)expression in T84 intestinal epithelial cells was measured by enzyme-linked immunosorbent assay and by Western Blot.Gut colonization,inflammation and procarcinogenic potential were assessed in a chronic infection model using CEABAC10 transgenic mice.Cell proliferation was analyzed by real-time mRNA quantification of PCNA and immunohistochemistry staining of Ki67.RESULTS:Analysis of mucosa-associated E.coli from colon cancer and diverticulosis specimens showed that whatever the origin of the E.coli strains,86%of cyclomodulin-positive E.coli belonged to B2 phylogroup and most harbored polyketide synthase(pks)island,which encodes colibactin,and/or cytotoxic necrotizing factor(cnf)genes.In vitro assays using I-407 intestinal epithelial cells revealed that mucosa-associated B2 E.coli strains were poorly adherent and invasive.However,mucosa-associated B2 E.coli similarly to Crohn’s disease-associated E.coli are able to induce CEACAM6expression in T84 intestinal epithelial cells.In addition,in vivo experiments using a chronic infection model of CEACAM6 expressing mice showed that B2 E.coli strain11G5 isolated from colon cancer is able to highly persist in the gut,and to induce colon inflammation,epithelial damages and cell proliferation.CONCLUSION:In conclusion,these data bring new insights into the ability of E.coli isolated from patients with colon cancer to establish persistent colonization,exacerbate inflammation and trigger carcinogenesis.     

Inhibition of tumor cell proliferation and motility by fibroblasts is both contact and soluble factor dependent

Normal human and murine fibroblasts can inhibit proliferation of tumor cells when cocultured in vitro. The inhibitory capacity varies depending on the donor and the site of origin of the fibroblast. We showed previously that effective inhibition requires formation of a morphologically intact fibroblast monolayer before seeding of the tumor cells. Here we show that inhibition is extended to motility of tumor cells and we dissect the factors responsible for these inhibitory functions. We find that inhibition is due to two different sets of molecules: (i) the extracellular matrix (ECM) and other surface proteins of the fibroblasts, which are responsible for contact-dependent inhibition of tumor cell proliferation; and (ii) soluble factors secreted by fibroblasts when confronted with tumor cells (confronted conditioned media, CCM) contribute to inhibition of tumor cell proliferation and motility. However, conditioned media (CM) obtained from fibroblasts alone (nonconfronted conditioned media, NCM) did not inhibit tumor cell proliferation and motility. In addition, quantitative PCR (Q-PCR) data show up-regulation of proinflammatory genes. Moreover, comparison of CCM and NCM with an antibody array for 507 different soluble human proteins revealed differential expression of growth differentiation factor 15, dickkopf-related protein 1, endothelial-monocyte-activating polypeptide II, ectodysplasin A2, Galectin-3, chemokine (C-X-C motif) ligand 2, Nidogen1, urokinase, and matrix metalloproteinase 3.The normal balance between epithelial cells and the surrounding stroma is disrupted during tumor development. Developing preneoplastic cells in the process of escaping from their intrinsic checkpoints that prevent illegitimate cell proliferation also have to overcome the microenvironmental forces that maintain the integrity of the normal tissue architecture. It is becoming increasingly clear that the normal microenvironment can restrict cancer development and progression (1–3). Inhibition of tumor cell growth by normal fibroblasts is one measurable manifestation of this multicomponential control. Part of this process is reflected by the ability of the tumor cell to corrupt the surrounding stroma and turn it from restrictive to supportive. The generation of cancer-associated fibroblasts (CAFs) that enhance angiogenesis and support tumor growth and spreading through the release of growth factors and cytokines is a case in point (1–5).We have departed from the observation of Stoker et al. that normal fibroblasts can inhibit the growth of admixed tumor cells upon contact (6). Having confirmed their findings, we have extended such findings into a high throughput microwell system and showed that the strength of the inhibition differs depending on the source of the fibroblasts. Moreover, such inhibition is contact dependent as well as requires an intact fibroblast monolayer (7, 8).Here we report the surprising finding that the inhibitory effect of normal fibroblasts is retained partially after fixation. We also show that live fibroblasts release soluble factors upon confrontation with tumor cells that increase their inhibitory effect and identify a number of the proteins and cytokines that could be involved in this intriguing process.     

Prognostic significance of the renal resistive index in the primary prevention of type II diabetes

The renal resistive index has been demonstrated to predict the progression of renal disease and recurrence of major cardiac events in high‐risk cardiovascular patients, in addition to other comorbidities. We aimed to assess the prognostic significance of the renal resistive index in type 2 diabetic patients for primary prevention. From 2008 to 2011, patients with type 2 diabetes underwent cardiovascular evaluation, including renal resistive index assessment by renal Doppler ultrasound. The incidence of all‐cause death, cardiovascular events, dialysis requirement or a twofold increase in creatinine was recorded. Survival curves were estimated by the Kaplan‐Meier method. Two hundred sixty‐six patients were included; 50% of the patients were men, an HbA1C level of 8.1 ± 1.7% (65 ± 13.6 mmol/mol) and a serum creatinine level of 8 [7‐9] mg/L. The mean 24‐hour systolic blood pressure, 24‐hour diastolic blood pressure, and 24‐hour pulse pressure were 133.4 ± 16.7, 76.5 ± 9.4, and 56.9 ± 12.4 mm Hg, respectively. The median renal resistive index was 0.7 [0.6‐0.7] with a threshold of 0.7 predictive of monitored events. After adjustment of the 24‐hour pulse pressure, age and 24‐hour heart rate, a renal resistive index ≥0.70 remained associated with all‐cause death (hazard ratio: 3.23 (1.16‐8.98); P = .025) and the composite endpoint of major clinical events (hazard ratio: 2.37 (1.34‐4.18); P = .003). An elevated renal resistive index with a threshold of 0.7 is an independent predictor of a first cardiovascular or renal event in type 2 diabetic patients. This simple index should be implemented in the multiparametric staging of diabetes.     

Postprandial hyperglycaemia following insulin suspensions by the artificial pancreas: Implications for bolus calculators

Conventional bolus calculators apply negative prandial corrections when premeal glucose levels are low. However, no study has evaluated the need for this negative correction with closed-loop systems. We analysed data retrospectively from a cohort study evaluating a closed-loop artificial pancreas system conducted in a diabetes camp over a period of 11 days. Meal boluses with negative correction (n = 98) of 47 participants aged 8 to 22 years were examined. If there was no insulin-on-board from previous boluses at mealtime, the postprandial hyperglycaemia rate increased with increased duration of insulin suspension (P = .03), with odds ratios being exaggerated by 17% per 10 minutes of suspension. However, if there was insulin-on-board from previous boluses, the hyperglycaemia rate did not change with increased duration of insulin suspension (P = .24). When there was no insulin-on-board, the rate of hyperglycaemia after meals preceded by no suspension was 21% (3/14), compared with 52% (12/23) and 64% (9/14) after meals preceded by suspensions of ≥50 and ≥70 minutes, respectively. Meal size did not influence these results. We conclude that, in the absence of insulin-on-board, negative prandial corrections may not be necessary following long insulin suspensions.     

Microbiologic characteristics and in vitro susceptibility to antimicrobials in a large population of patients with cardiovascular implantable electronic device infection

Microbiologic Characteristics and In Vitro Susceptibility to Antimicrobials. Introduction: The incidence of cardiovascular implantable electronic device (CIED) infection is steadily increasing. However, no consensus has been reached with respect to the type and duration of antimicrobial therapy in this specific population of patients. The role played by new anti‐Staphylococcus agents has not been defined. The aims of this study were to describe the microbiological characteristics of a large population of patients with CIED infections and to test the in vitro susceptibility of the various strains to different antimicrobials. Methods: Two hundred eighty‐six patients with CIED infection were included. The minimal inhibitory concentrations of 9 antimicrobials, including linezolid, tigecycline, and daptomycin were measured against all strains of staphylococci isolated. Results: Microbiologic confirmation was obtained in 252 (88%) patients, the vast majority were from Staphylococcus species (86%), 90% of these were coagulase negative strains and 10% were Staphylococcus aureus; 30.5% were methicillin‐resistant. All strains were susceptible to vancomycin, nearly 15% of coagulase negative strains were nonsusceptible to teicoplanin, and nearly 100% of the strains were susceptible to the 3 new antimicrobials. Conclusions: In this large contemporary study, we show that Staphylococcus is by far the most common cause of CIED infections, with the majority due to coagulase negative strains. Methicillin‐resistance is common in this population. Currently, we would recommend vancomycin as first‐line empirical therapy. However, given that not all patients tolerate vancomycin, we believe that newer antimicrobial therapies should now be tested in clinical trials to establish their clinical effectiveness in treating patients with device infections.     

Pudendal Neurolysis by Laparoscopy

Study ObjectiveTo show how pudendal neurolysis can be managed safely with a laparoscopic approach.DesignStepwise demonstration of the technique with narrated video footage.SettingThe pudendal nerve is formed from spinal roots at levels S2, S3, and S4. It passes through the pelvis parallel to the pudendal vein and artery. This nerve exits the pelvis between the sacrospinous and sacrotuberous ligaments then passes through Alcock's canal. It can be compressed and responsible for pain in the gluteal and perineal regions.After confirmation of the diagnosis by positive analgesic block with computed tomography infiltration of the pudendal nerve, surgical decompression may be considered.The usual access procedures are the transglutal and transischiorectal ways.InterventionsThis video shows a total laparoscopic approach for a right pudendal neurolysis. It is a step-by-step didactic video.This technique of decompression of the right pudendal nerve by laparoscopy by means of dissection of the ischiorectal fossa along the right internal obturator muscle, after visualization of the obturator vessels and identification of the pudendal nerve, allowed the section of the right sacrospinous ligament and complete removal with repositioning of the nerve in its path. The nerve was followed until it passed freely through Alcock's canal. The procedure went well and without complications, with clinical improvement on waking up.ConclusionPudendal nerve neurolysis by laparoscopic technique is a reproducible and safe method for treating pudendal neuralgia, allowing good visualization and dissection of the entire pelvis toward the ischiorectal fossa.     

Emerging technologies to study glial cells

Development, physiological functions, and pathologies of the brain depend on tight interactions between neurons and different types of glial cells, such as astrocytes, microglia, oligodendrocytes, and oligodendrocyte precursor cells. Assessing the relative contribution of different glial cell types is required for the full understanding of brain function and dysfunction. Over the recent years, several technological breakthroughs were achieved, allowing “glio-scientists” to address new challenging biological questions. These technical developments make it possible to study the roles of specific cell types with medium or high-content workflows and perform fine analysis of their mutual interactions in a preserved environment. This review illustrates the potency of several cutting-edge experimental approaches (advanced cell cultures, induced pluripotent stem cell (iPSC)-derived human glial cells, viral vectors, in situ glia imaging, opto- and chemogenetic approaches, and high-content molecular analysis) to unravel the role of glial cells in specific brain functions or diseases. It also illustrates the translation of some techniques to the clinics, to monitor glial cells in patients, through specific brain imaging methods. The advantages, pitfalls, and future developments are discussed for each technique, and selected examples are provided to illustrate how specific “gliobiological” questions can now be tackled.