Sessile serrated adenoma/polyp detection rate of water exchange, Endocuff, and cap colonoscopy: A network meta-analysis.

BACKGROUND AND AIM: Sessile serrated adenoma/polyp (SSA/P) may contribute to interval cancer. In a recent meta-analysis, water exchange (WE) was shown to be superior to Endocuff and cap colonoscopy at adenoma and advanced adenoma detection. The strong positive correlation between adenoma detection rate (ADR), advanced adenoma detection rate (AADR), and sessile serrated adenoma/polyp detection rate (SSA/PDR) prompted us to hypothesize that WE could significantly improve SSA/PDR compared with Endocuff and cap colonoscopy. METHODS: The literature was searched for all randomized controlled trials (RCTs) that reported SSA/PDR as an outcome and included the keywords colonoscopy, and water exchange, Endocuff, or cap. We performed traditional network meta-analyses with random effect models comparing SSA/PDR of each method using air insufflation as the control and reported the odds ratios (ORs) with 95% confidence interval (CI). Performances were ranked based on P-score. RESULTS: A total of 531 articles resulted from initial keywords search. Eleven RCTs were included in the analysis. A total of 7856 patients underwent air insufflation, WE, Endocuff, or cap colonoscopy. WE significantly increased SSA/PDR (OR 2.04; 95% CI 1.33-3.13). Endocuff (OR 1.15; 95% CI 0.94-1.41) and cap (OR 1.08; 95% CI 0.42-2.74) did not significantly impact SSA/P detection. P-scores for WE (0.96), Endocuff (0.49), cap (0.37), and air insufflation (0.17) suggested that WE had the highest SSA/PDR. The results did not change after adjusting for mean withdrawal time and indication for colonoscopy. CONCLUSION: Water exchange significantly increases SSA/PDR and is superior to Endocuff and cap colonoscopy at detecting SSA/P.

Adenoma and Advanced Adenoma Detection Rates of Water Exchange, Endocuff, and Cap Colonoscopy: A Network Meta-Analysis with Pooled Data of Randomized Controlled Trials.

BACKGROUND AND AIMS: A network meta-analysis showed that low-cost optimization of existing resources was as effective as distal add-on devices in increasing adenoma detection rate (ADR). We assessed the impacts of water exchange (WE), Endocuff, and cap colonoscopy on ADR and advanced adenoma detection rate (AADR). We hypothesized that WE may be superior at improving ADR and AADR. METHODS: The literature was searched for all randomized controlled trials (RCTs) that reported ADR as an outcome and included the keywords colonoscopy, and water exchange, Endocuff, or cap. We performed traditional network meta-analyses with random effect models comparing ADR and AADR of each method using air insufflation (AI) as the control and reported the odds ratios with 95% confidence interval. Performances were ranked based on P-score. RESULTS: Twenty-one RCTs met inclusion criteria. Fourteen RCTs also reported AADR. Both WE [1.46 (1.20-1.76)] and Endocuff [1.39 (1.17-1.66)] significantly increase ADR, while cap has no impact on ADR [1.00 (0.82-1.22)]. P-scores for WE (0.88), Endocuff (0.79), cap (0.17), and AI (0.17) suggest WE has the highest ADR. WE [1.38 (1.12-1.70)], but not Endocuff [0.96 (0.76-1.21)] or cap [1.06 (0.85-1.32)], significantly increases AADR. P-scores for WE (0.98), cap (0.50), AI (0.31), and Endocuff (0.21) suggest WE is more effective at increasing AADR. The results did not change after adjusting for age, proportion of males, and withdrawal time. CONCLUSION: WE may be the modality of choice to maximally improve ADR and AADR.

Structure and function of enterotoxigenic Escherichia coli fimbriae from differing assembly pathways.

Pathogenic enterotoxigenic Escherichia coli (ETEC) are the major bacterial cause of diarrhea in young children in developing countries and in travelers, causing significant mortality in children. Adhesive fimbriae are a prime virulence factor for ETEC, initiating colonization of the small intestinal epithelium. Similar to other Gram-negative bacteria, ETEC express one or more diverse fimbriae, some assembled by the chaperone-usher pathway and others by the alternate chaperone pathway. Here, we elucidate structural and biophysical aspects and adaptations of each fimbrial type to its respective host niche. CS20 fimbriae are compared with colonization factor antigen I (CFA/I) fimbriae, which are two ETEC fimbriae assembled via different pathways, and with P-fimbriae from uropathogenic E. coli. Many fimbriae unwind from their native helical filament to an extended linear conformation under force, thereby sustaining adhesion by reducing load at the point of contact between the bacterium and the target cell. CFA/I fimbriae require the least force to unwind, followed by CS20 fimbriae and then P-fimbriae, which require the highest unwinding force. We conclude from our electron microscopy reconstructions, modeling and force spectroscopy data that the target niche plays a central role in the biophysical properties of fimbriae that are critical for bacterial pathophysiology.

A review of water exchange and artificial intelligence in improving adenoma detection.

Water exchange (WE) and artificial intelligence (AI) have made critical advances during the past decade. WE significantly increases adenoma detection and AI holds the potential to help endoscopists detect more polyps and adenomas. We performed an electronic literature search on PubMed using the following keywords: water-assisted and water exchange colonoscopy, adenoma and polyp detection, artificial intelligence, deep learning, neural networks, and computer-aided colonoscopy. We reviewed relevant articles published in English from 2010 to May 2020. Additional articles were searched manually from the reference lists of the publications reviewed. We discussed recent advances in both WE and AI, including their advantages and limitations. AI may mitigate operator-dependent factors that limit the potential of WE. By increasing bowel cleanliness and improving visualization, WE may provide the platform to optimize the performance of AI for colonoscopies. The strengths of WE and AI may complement each other in spite of their weaknesses to maximize adenoma detection.

Direct-acting Antiviral Therapy Improves the Outcome of Chronic Hepatitis C/intermediate-stage B Hepatocellular Carcinoma Patients.

BACKGROUND/AIM: The benefit of direct-acting antiviral therapy (DAA) in chronic hepatitis C (CHC) infected patients who received curative treatment for early-stage hepatocellular carcinoma (HCC) is well known, but is unclear for intermediate stage HCC. PATIENTS AND METHODS: CHC patients with Barcelona Clinic Liver Cancer (BCLC) stage B HCC receiving chemoembolization were identified. Univariate, multivariate analyses, and Kaplan-Meier curve were used to identify factors associated with survival outcomes. RESULTS: Among 113 included patients, the median survival of DAA treated group (n=14) and non-treated group (n=99) were 40.1 months and 22.9 months, respectively. Multivariate analysis showed that Eastern Cooperative Oncology Group (ECOG) score, DAA, and serum albumin were key independent factors associated with overall survival. Moreover, the time-to-complete remission (TTCR) was improved in the DAA treated group. CONCLUSION: ECOG, DAA, and serum albumin were prognostic factors for CHC/intermediate-stage HCC patients. DAA was also a beneficial factor for TTCR.

Optical High Content Nanoscopy of Epigenetic Marks Decodes Phenotypic Divergence in Stem Cells.

While distinct stem cell phenotypes follow global changes in chromatin marks, single-cell chromatin technologies are unable to resolve or predict stem cell fates. We propose the first such use of optical high content nanoscopy of histone epigenetic marks (epi-marks) in stem cells to classify emergent cell states. By combining nanoscopy with epi-mark textural image informatics, we developed a novel approach, termed EDICTS (Epi-mark Descriptor Imaging of Cell Transitional States), to discern chromatin organizational changes, demarcate lineage gradations across a range of stem cell types and robustly track lineage restriction kinetics. We demonstrate the utility of EDICTS by predicting the lineage progression of stem cells cultured on biomaterial substrates with graded nanotopographies and mechanical stiffness, thus parsing the role of specific biophysical cues as sensitive epigenetic drivers. We also demonstrate the unique power of EDICTS to resolve cellular states based on epi-marks that cannot be detected via mass spectrometry based methods for quantifying the abundance of histone post-translational modifications. Overall, EDICTS represents a powerful new methodology to predict single cell lineage decisions by integrating high content super-resolution nanoscopy and imaging informatics of the nuclear organization of epi-marks.

Characterization of the surfaceome of the metal-reducing bacterium Desulfotomaculum reducens.

Desulfotomaculum reducens strain MI-1 is a Gram-positive, sulfate-reducing bacterium also capable of reducing Fe(III). Metal reduction in Gram-positive bacteria is poorly understood. Here, we investigated Fe(III) reduction with lactate, a non-fermentable substrate, as the electron donor. Lactate consumption is concomitant to Fe(III) reduction, but does not support significant growth, suggesting that little energy can be conserved from this process and that it may occur fortuitously. D. reducens can reduce both soluble [Fe(III)-citrate] and insoluble (hydrous ferric oxide, HFO) Fe(III). Because physically inaccessible HFO was not reduced, we concluded that reduction requires direct contact under these experimental conditions. This implies the presence of a surface exposed reductase capable of transferring electrons from the cell to the extracellular electron acceptor. With the goal of characterizing the role of surface proteins in D. reducens and of identifying candidate Fe(III) reductases, we carried out an investigation of the surface proteome (surfaceome) of D. reducens. Cell surface exposed proteins were extracted by trypsin cell shaving or by lysozyme treatment, and analyzed by liquid chromatography-tandem mass spectrometry. This investigation revealed that the surfaceome fulfills many functions, including solute transport, protein export, maturation and hydrolysis, peptidoglycan synthesis and modification, and chemotaxis. Furthermore, a few redox-active proteins were identified. Among these, three are putatively involved in Fe(III) reduction, i.e., a membrane-bound hydrogenase 4Fe-4S cluster subunit (Dred_0462), a heterodisulfide reductase subunit A (Dred_0143) and a protein annotated as alkyl hydroperoxide reductase but likely functioning as a thiol-disulfide oxidoreductase (Dred_1533).

Combined scanning transmission X-ray and electron microscopy for the characterization of bacterial endospores.

Endospores (also referred to as bacterial spores) are bacterial structures formed by several bacterial species of the phylum Firmicutes. Spores form as a response to environmental stress. These structures exhibit remarkable resistance to harsh environmental conditions such as exposure to heat, desiccation, and chemical oxidants. The spores include several layers of protein and peptidoglycan that surround a core harboring DNA as well as high concentrations of calcium and dipicolinic acid (DPA). A combination of scanning transmission X-ray microscopy, scanning transmission electron microscopy, and energy dispersive spectroscopy was used for the direct quantitative characterization of bacterial spores. The concentration and localization of DPA, Ca(2+) , and other elements were determined and compared for the core and cortex of spores from two distinct genera: Bacillus subtilis and Desulfotomaculum reducens. This micro-spectroscopic approach is uniquely suited for the direct study of individual bacterial spores, while classical molecular and biochemical methods access only bulk characteristics.

Neurokinin B induces c-fos transcription via protein kinase C and activation of serum response factor and Elk-1 in immortalized GnRH neurons.

Mutations in neurokinin B (NKB) and its receptor, NK3R, were identified in human patients with hypogonadotropic hypogonadism, a disorder characterized by lack of puberty and infertility. Further studies have suggested that NKB acts at the level of the hypothalamus to control GnRH neuron activity, either directly or indirectly. We recently reported that treatment with senktide, a NK3R agonist, induced GnRH secretion and expression of c-fos mRNA in GT1-7 cells. Here, we map the responsive region in the murine c-fos promoter to between -400 and -200 bp, identify the signal transducer and activator of transcription (STAT) (-345) and serum response element (-310) sites as required for induction, a modulatory role for the Ets site (-318), and show that induction is protein kinase C dependent. Using gel shift and Gal4 assays, we further show that phosphorylation of Elk-1 leads to binding to DNA in complex with serum response factor at serum response element and Ets sites within the c-fos promoter. Thus, we determine molecular mechanisms involved in NKB regulation of c-fos induction, which may play a role in modulation of GnRH neuron activation.

Neurokinin B causes acute GnRH secretion and repression of GnRH transcription in GT1-7 GnRH neurons.

Genetic studies in human patients with idiopathic hypogonadotropic hypogonadism (IHH) identified mutations in the genes that encode neurokinin B (NKB) and the neurokinin 3 receptor (NK3R). However, determining the mechanism whereby NKB regulates gonadotropin secretion has been difficult because of conflicting results from in vivo studies investigating the luteinizing hormone (LH) response to senktide, a NK3R agonist. NK3R is expressed in a subset of GnRH neurons and in kisspeptin neurons that are known to regulate GnRH secretion. Thus, one potential source of inconsistency is that NKB could produce opposing direct and indirect effects on GnRH secretion. Here, we employ the GT1-7 cell model to elucidate the direct effects of NKB on GnRH neuron function. We find that GT1-7 cells express NK3R and respond to acute senktide treatment with c-Fos induction and increased GnRH secretion. In contrast, long-term senktide treatment decreased GnRH secretion. Next, we focus on the examination of the mechanism underlying the long-term decrease in secretion and determine that senktide treatment represses transcription of GnRH. We further show that this repression of GnRH transcription may involve enhanced c-Fos protein binding at novel activator protein-1 (AP-1) half-sites identified in enhancer 1 and the promoter, as well as chromatin remodeling at the promoter of the GnRH gene. These data indicate that NKB could directly regulate secretion from NK3R-expressing GnRH neurons. Furthermore, whether the response is inhibitory or stimulatory toward GnRH secretion could depend on the history or length of exposure to NKB because of a repressive effect on GnRH transcription.