Attenuation of a DNA cruciform by a conserved regulator directs T3SS1 mediated virulence in Vibrio parahaemolyticus.

Pathogenic Vibrio species account for 3-5 million annual life-threatening human infections. Virulence is driven by bacterial hemolysin and toxin gene expression often positively regulated by the winged helix-turn-helix (wHTH) HlyU transcriptional regulator family and silenced by histone-like nucleoid structural protein (H-NS). In the case of Vibrio parahaemolyticus, HlyU is required for virulence gene expression associated with type 3 Secretion System-1 (T3SS1) although its mechanism of action is not understood. Here, we provide evidence for DNA cruciform attenuation mediated by HlyU binding to support concomitant virulence gene expression. Genetic and biochemical experiments revealed that upon HlyU mediated DNA cruciform attenuation, an intergenic cryptic promoter became accessible allowing for exsA mRNA expression and initiation of an ExsA autoactivation feedback loop at a separate ExsA-dependent promoter. Using a heterologous E. coli expression system, we reconstituted the dual promoter elements which revealed that HlyU binding and DNA cruciform attenuation were strictly required to initiate the ExsA autoactivation loop. The data indicate that HlyU acts to attenuate a transcriptional repressive DNA cruciform to support T3SS1 virulence gene expression and reveals a non-canonical extricating gene regulation mechanism in pathogenic Vibrio species.

Trends in the Utilization of Intragastric Balloons: a 5-Year Analysis of the MBSAQIP Registry.

PURPOSE: The use of intragastric balloons (IGBs) for the treatment of obesity was approved by the US Food and Drug Administration in 2015. This study aims to characterize preoperative factors and outcomes of patients undergoing IGB therapy compared to bariatric surgery (non-IGB) and evaluate 5-year trends in IGB use. METHODS: A retrospective cohort study was performed by extracting data from the MBSAQIP registry between 2015 and 2019. All non-IGB and IGB procedures were included while revisional and emergency surgeries were excluded. Multivariable logistic regression analysis was used to determine independent predictors of patient selection for IGB therapy. RESULTS: Of 652,927 patients identified, only 2910 (0.4%) underwent IGB therapy. Patients who underwent IGB therapy were older (46.7 ± 11.4 years vs 44.4 ± 12.0 years; p < 0.0001), had lower BMI at baseline (37.0 ± 6.2 kg/m2 vs 45.3 ± 7.8 kg/m2; p < 0.0001), and were overall healthier with fewer comorbidities and better functional status. The rate of early nonoperative reintervention was higher in the IGB cohort (7.7% vs 1.1%; p < 0.0001). Age was the only significant predictor of selection for IGB therapy (OR 1.32; 95% CI 1.24-1.37; p < 0.0001). The number of IGB procedures reported between 2016 and 2019 declined significantly (953 (0.62%) vs 418 (0.25%); p < 0.0001). CONCLUSIONS: Appropriate indications for IGBs appear to be increasingly limited. The ongoing role of IGBs in the treatment of obesity is unclear given the safety and efficacy of modern bariatric surgery and new pharmacological agents for weight loss.

Smoking in bariatric surgery: a systematic review.

BACKGROUND: The prevalence of smoking among patients undergoing bariatric surgery has been reported to be as high as 40%. The effect of smoking in the perioperative period has been extensively studied for various surgical procedures, but limited data are available for bariatric surgery. The objective of this study is to review the existing literature to assess: (1) the impact of smoking on postoperative morbidity and mortality after bariatric surgery, (2) the relationship between smoking and weight loss after bariatric surgery, and (3) the efficacy of smoking cessation in the perioperative period among bariatric surgery patients. METHODS: A comprehensive search of electronic databases including MEDLINE, EMBASE and the Cochrane Library from 1946 to February 2020 was performed to identify relevant articles. Following an initial screen of 940 titles and abstracts, 540 full articles were reviewed. RESULTS: Forty-eight studies met criteria for analysis: five structured interviews, three longitudinal studies, thirty-two retrospective studies and eight prospective studies. Smoking within 1 year prior to bariatric surgery was found to be an independent risk factor for increased 30-day mortality and major postoperative complications, particularly wound and pulmonary complications. Smoking was significantly associated with long-term complications including marginal ulceration and bone fracture. Smoking has little to no effect on weight loss following bariatric surgery, with studies reporting at most a 3% increased percentage excess weight loss. Rates of smoking recidivism are high with studies reporting that up to 17% of patients continue to smoke postoperatively. CONCLUSIONS: Although current best practice guidelines recommend only a minimum of 6 weeks of abstinence from smoking prior to bariatric surgery, the findings of this review suggest that smoking within 1 year prior to bariatric surgery is associated with significant postoperative morbidity. More investigation is needed on strategies to improve smoking cessation compliance among bariatric surgery patients in the perioperative period.

Oxidative stress enhances tumorigenicity and stem-like features via the activation of the Wnt/ß-catenin/MYC/Sox2 axis in ALK-positive anaplastic large-cell lymphoma.

BACKGROUND: The phenomenon that malignant cells can acquire stemness under specific stimuli, encompassed under the concept of cancer cell plasticity, has been well-described in epithelial malignancies. To our knowledge, cancer cell plasticity has not yet been described in hematopoietic cancers. To illustrate and study cancer cell plasticity in hematopoietic cancers, we employed an in-vitro experimental model of ALK-positive anaplastic large-cell lymphoma (ALK+ALCL) that is based on the phenotypic and functional dichotomy of these cells, with cells responsive to a Sox2 reporter (i.e. RR cells) being significantly more stem-like than those unresponsive to the reporter (i.e. RU cells). METHODS: H2O2 was employed to trigger oxidative stress. GFP expression and luciferase activity, readouts of the Sox2 reporter activity, were quantified by using flow cytometry and luciferase activity assay, respectively. Doxorubicin-resistance and clonogenicity were assessed by using the MTS, methylcellulose colony formation and limiting dilution assays. Western blotting and quantitative PCR were used to assess the expression of various members of the Wnt/ß-catenin pathway. Pull-down studies using a Sox2 binding consensus sequence were used to assess Sox2-DNA binding. Quercetin and 10074-G5 were used to inhibit ß-catenin and MYC, respectively. siRNA was used to downregulate Sox2. RESULTS: Under H2O2-induced oxidative stress, a substantial fraction of RU cells was found to convert to RR cells, as evidenced by their acquisition of GFP expression and luciferase activity. Compared to the native RU cells, converted RR cells had significantly higher levels of doxorubicin-resistance, clonogenicity and sphere formation. Converted RR cells were characterized by an upregulation of the Wnt/ß-catenin/MYC/Sox2 signaling axis, previously found to be the key regulator of the RU/RR dichotomy in ALK+ALCL. Furthermore, Sox2 was found to bind to DNA efficiently in converted RR cells but not RU cells, and this finding correlated with significant elevations of several Sox2 downstream targets such as WNT2B and BCL9. Lastly, inhibition of ß-catenin, MYC or Sox2 in RU cells significantly abrogated the H2O2-induced RU/RR conversion. CONCLUSIONS: We have demonstrated that cancer cell plasticity exists in ALK+ALCL, a type of hematopoietic cancer. In this cancer type, the Wnt/ß-catenin/MYC/Sox2 axis is an important regulator of cancer cell plasticity.

Phosphorylation of Sox2 at Threonine 116 is a Potential Marker to Identify a Subset of Breast Cancer Cells with High Tumorigenecity and Stem-Like Features.

We have previously identified a novel phenotypic dichotomy in breast cancer (BC) based on the response to a SRR2 (Sox2 regulatory region 2) reporter, with reporter responsive (RR) cells being more tumorigenic/stem-like than reporter unresponsive (RU) cells. Since the expression level of Sox2 is comparable between the two cell subsets, we hypothesized that post-translational modifications of Sox2 contribute to their differential reporter response and phenotypic differences. By liquid chromatography-mass spectrometry, we found Sox2 to be phosphorylated in RR but not RU cells. Threonine 116 is an important phosphorylation site, since transfection of the T116A mutant into RR cells significantly decreased the SRR2 reporter luciferase activity and the RR-associated phenotype. Oxidative stress-induced conversion of RU into RR cells was accompanied by Sox2 phosphorylation at T116 and increased Sox2-DNA binding. In a cohort of BC, we found significant correlations between the proportion of tumor cells immuno-reactive with anti-phosphorylated Sox2T116 and a high tumor grade (p = 0.006), vascular invasion (p = 0.001) and estrogen receptor expression (p = 0.032). In conclusion, our data suggests that phosphorylation of Sox2T116 contributes to the tumorigenic/stem-like features in RR cells. Detection of phospho-Sox2T116 may be useful in identifying a small subset of tumor cells carrying stem-like/tumorigenic features in BC.

A Systematic Review and Meta-Analysis of Outcomes for Type 1 Diabetes after Bariatric Surgery.

Background. The utility of bariatric surgery in type 1 diabetes remains controversial. The aim of the present study is to evaluate glycemic control outcomes in obese patients with type 1 diabetes after bariatric surgery. Methods. A comprehensive search of electronic databases was completed. Inclusion criteria included human adult subjects with BMI ≥35 kg/m(2) and a confirmed diagnosis of type 1 diabetes who underwent a bariatric surgical procedure. Results. Thirteen primary studies (86 patients) were included. Subjects had a mean age of 41.16 ± 6.76 years with a mean BMI of 42.50 ± 2.65 kg/m(2). There was a marked reduction in BMI postoperatively at 12 months and at study endpoint to 29.55 ± 1.76 kg/m(2) (P < 0.00001) and 30.63 ± 2.09 kg/m(2) (P < 0.00001), respectively. Preoperative weighted mean total daily insulin requirement was 98 ± 26 IU/d, which decreased significantly to 36 ± 15 IU/d (P < 0.00001) and 42 ± 11 IU/d (P < 0.00001) at 12 months and at study endpoint, respectively. An improvement in HbA1c was also seen from 8.46 ± 0.78% preoperatively to 7.95 ± 0.55% (P = 0.01) and 8.13 ± 0.86% (P = 0.03) at 12 months and at study endpoint, respectively. Conclusion. Bariatric surgery in patients with type 1 diabetes leads to significant reductions in BMI and improvements in glycemic control.

Roux-en-Y Gastric Bypass in the Elderly: a Systematic Review.

The prevalence of severe obesity in the elderly is increasing. This systematic review reviews the literature in reference to the efficacy and safety of bariatric surgery on the elderly patient ≥ 65 years. A comprehensive search of electronic databases was completed. The data was limited to include only Roux-en-Y gastric bypass patients ≥ 65 years. Eight primary studies (1835 patients) were included, all case series. Mean age was 67.6 years. Mean excess weight loss at study endpoint was 66.2 %. Mean 30-day mortality was 0.14 %. The mean total post-operative complication rate was 21.1 %, with wound infections being the most common (7.58 %) followed by cardiorespiratory complications (2.96 %). Bariatric surgery is effective in producing marked weight loss in patients ≥ 65 years with an acceptable safety profile.