Wnt4a Is Indispensable for Genital Duct Elongation but Not for Gonadal Sex Differentiation in the Medaka, Oryzias latipes.

In most vertebrates, the oviducts and sperm ducts are derived from the Müllerian ducts and Wolffian ducts, respectively. However, in teleosts, the genital ducts are formed by the posterior extension of gonads in both sexes. Whether the genital ducts of teleosts are newly evolved organs or variants of Müllerian ducts is an important question for understanding evolutionary mechanisms of morphogenesis. One of the genes essential for Müllerian duct formation in mice is Wnt4, which is expressed in the mesenchyme and induces invagination of the coelomic epithelium and its posterior elongation. Here, we addressed the above question by examining genital duct development in mutants of two Wnt4 genes in the medaka (wnt4a is orthologous to mouse Wnt4, and wnt4b is paralogous). The wnt4b mutants had a short body but were fertile with normal genital ducts. In contrast, both male and female wnt4a mutants had their posterior elongation of the gonads stopped within or just outside the coelom. The mutants retained the posterior parts of ovarian cavities or sperm duct primordia, which are potential target tissues of Wnt4a. The gonads of female scl mutants (unable to synthesize sex steroids) lacked these tissues and did not develop genital ducts. Medaka wnt4a was expressed in the mesenchyme ventral to the genital ducts in both sexes. Taken together, the data strongly suggest that the mouse Müllerian ducts and the medaka genital ducts share homologous developmental processes. Additionally, the wnt4a or wnt4b single mutants and the double mutants did not show sex-reversal, implying that both genes are dispensable for gonadal sex differentiation in the medaka.

Benefits and limitations of cap-fitted colonoscopy in screening colonoscopy.

BACKGROUND: Colonoscopy is widely used to detect colorectal cancer and to remove precancerous lesions to reduce the risk of colonic cancer. AIMS: To examine the benefits and limitations of cap-fitted colonoscopy compared to conventional colonoscopy in terms of technical performance and colorectal adenoma detection rate. METHODS: Screening colonoscopies performed from 2009 to 2010 with or without a transparent cap were retrospectively examined to compare the rate of successful intubation, cecal intubation time, and number, size, shape, and location of adenomas detected. An inclusion criterion was visualization of >95 % of the right colon. RESULTS: Data from 2,301 colonoscopies (1,165 with cap-fitted colonoscopy, 1,136 without the transparent cap) were retrospectively analyzed. Procedures were performed by four experienced endoscopists. The subjects' demographic characteristics and technical performances were similar between the two methods. The only significant difference in the technical performance between the two techniques was a shorter cecal intubation time with cap-fitted colonoscopy (5.3 vs. 6.6 min; p = 0.045) by one endoscopist. The total number of adenomas detected was significantly higher with cap-fitted colonoscopy than without the cap (586 vs. 484, respectively; p < 0.0001). Adenoma detection with cap-fitted endoscopy was significantly higher in the right colon than in the left colon (19 vs. 12 %, respectively; p = 0.0001). CONCLUSION: Cap-fitted colonoscopy did not improve the technical aspects of colonoscopy but significantly increased adenoma detection, especially in the right colon. It did not increase the detection rate of flat or depressed adenomas.

Hood-assisted colonoscopy is more effective in detection of colorectal adenomas than narrow-band imaging.

BACKGROUND & AIMS: Colonoscopy, using either a transparent retractable extension device or narrow band imaging, is thought to improve colon adenoma detection. We compared the abilities of a transparent retractable extension device and narrow band imaging to detect colorectal adenomas. METHODS: One hundred and seven patients with colonic adenomas that were detected by traditional colonoscopy were randomly assigned to groups that underwent a second colonoscopy that used either a transparent retractable extension or narrow band imaging; adenomas were removed. The principal outcome parameters were the number, size, shape, and location of adenomas detected. The patients' demographic characteristics, indications for colonoscopy, and cecal intubation times were similar between groups. RESULTS: Use of the transparent retractable extension resulted in detection of 31% more adenomas than the initial procedure (P < .0001). The majority of newly discovered adenomas were sessile (79%; 26/33) and less than 5 mm in size (73%; 24/33). There was no significant increase in adenoma detection (5%) between first colonoscopy and second colonoscopy using narrow band imaging. Additional adenomas were found in 40.7% of patients that were examined using the transparent hood (22/54) versus 13.2% of those examined using narrow band imaging (7/53) (P = .0028). CONCLUSIONS: Colonoscopy with a transparent retractable extension significantly improved the adenoma detection rate compared with repeat colonoscopy using narrow band imaging.

Biliary stenting in the management of large or multiple common bile duct stones.

BACKGROUND: Endoscopic biliary stenting with a plastic stent is often performed to prevent impaction of common bile duct (CBD) stones. The therapeutic effect of a plastic stent placement in terms of reduction in stone size and number has not been established. OBJECTIVE: The aim of this study was to study the effect of biliary stenting as therapy for CBD stones. DESIGN: Retrospective study. SETTING: Municipal hospital outpatients. INTERVENTIONS: Patients with large (> or = 20 mm) and/or multiple (> or = 3) stones had placement of a 7F double-pigtail plastic stent without stone extraction at the initial ERCP. Approximately 2 months later, stone removal was attempted. The number and size of CBD stones before and after stent placement, stone clearance, complications, and 180-day mortality were evaluated. RESULTS: Forty patients were studied. Stent placement averaged 65 days (range, 50-82 days). The median number (interquartile range) of stones per patient fell after stent placement (4.0 [3.0] before vs. 2.0 [1.0] after; P < .0001). Characteristically, larger stones became smaller and small stones disappeared (ie, the median stone index decreased from 4.6 [3.0] to 2.0 [1.5]; P < .0001). Stone clearance at the second ERCP was achieved in 37 out of 40 patients (93%). Complications included cholangitis (13%) and pancreatitis (5%) after the second ERCP. No 180-day mortality occurred. LIMITATIONS: A retrospective, single-center study. CONCLUSIONS: Stent placement for 2 months was associated with large and/or multiple CBD stones becoming smaller and/or disappearing without any complications. Stenting followed by a wait period may assist in difficult CBD stone removal.

Long-term luseogliflozin therapy improves histological activity of non-alcoholic steatohepatitis accompanied by type 2 diabetes mellitus.

A 60-year-old Japanese woman was referred to our hospital for further examination of persistent liver dysfunction. She had been suffering from type 2 diabetes mellitus since the age of 50 years. Her hemoglobin A1c (HbA1c) value was as high as 7.8% despite treatment with dipeptidyl peptidase-4 inhibitor, metformin, and sulfonylurea. After excluding viral hepatitis, alcohol or drug-induced liver injury, and autoimmune liver diseases, liver histology evidence of macrovesicular steatosis, hepatocyte ballooning, and pericellular fibrosis confirmed a diagnosis of non-alcoholic steatohepatitis (NASH). Luseogliflozin (2.5 mg/day), a sodium-glucose cotransporter 2 inhibitor (SGLT2I), was co-administered to strengthen glycemic control. Liver enzymes and HbA1c gradually improved without any adverse events. A second liver biopsy at 15 months after luseogliflozin commencement revealed improvements in steatosis, fibrosis, and overall histological activity score. This case demonstrates that long-term luseogliflozin may be a good therapeutic option for diabetic NAFLD/NASH patients. The merits of persistent SGLT2I administration for NAFLD/NASH patients warrant validation in future studies.

Legionella pneumophila in rainwater on roads.

During rain, transient puddles form on roads, and this water is splashed into the air by moving vehicles. To determine whether this water contains Legionella pneumophila, we collected samples from roads. We found that L. pneumophila are abundant in these puddles, especially during warm weather.

14-3-3sigma-dependent resistance to cisplatin.

BACKGROUND: A major factor that impedes the clinical success of cisplatin-based chemotherapy for cancer is cisplatin resistance by cancer cells. MATERIALS AND METHODS: The sensitivity of parental HCT116 human colon cancer cell line and its isogenic gene-knockout sub-lines to cisplatin was determined by clonogenicity assay; furthermore, p53 activation, p21 expression, cell cycle arrest and senescence in these cells after cisplatin treatment were investigated. RESULTS: Parental cells were six times more resistant than 14-3-3sigma-knockout (sigma-KO) cells to cisplatin. Moreover, activation of p53, p53-dependent expression of p21 and p21-dependent senescence were observed in sigma-KO, but not parental cells after a treatment with a low cisplatin dose. CONCLUSION: A 14-3-3sigma-dependent mechanism inhibits p53 activation in parental cells treated with a low cisplatin dose, thereby blocking p21 expression that is essential for senescence and consequently conferring to the parental cells a significant degree of resistance to cisplatin.

Temperature-dependent parasitic relationship between Legionella pneumophila and a free-living amoeba (Acanthamoeba castellanii).

We analyzed the effects of temperature on the interaction of Legionella pneumophila with Acanthamoeba castellanii. At <20 degrees C, overexpression of type 1 metacaspase, a stimulator of A. castellanii encystation, was associated with a reduced number of bacteria within amoeba. At low temperatures, A. castellanii seems to eliminate L. pneumophila by encystation and digestion.

Comparison of newly found polyps after removal of small colorectal polyps with cold or hot snare polypectomy.

BACKGROUND AND STUDY AIMS: There are limited data regarding polyp recurrence following cold or hot snare polypectomy for small colorectal polyps. The aim of this study was to evaluate the prevalence of newly found polyp after cold or hot snare polypectomy and the predictive factors. PATIENTS AND METHODS: This was a retrospective case-control study at a single municipal hospital. Patients undergoing cold or hot snare polypectomy for colorectal polyps≤8 mm included in a previous study (Digestion 2011; 84:78) were enrolled. Newly found polyps were defined as polyps detected at follow-up colonoscopy within 3 years. Predictive factors for new polyps were assessed by multivariate analysis using logistic regression. RESULTS: A total of 72 patients (female 22, mean age 68) with 184 polyps were enrolled. Eighty-nine polyps (mean size±SD, 5.3±2 mm) were resected with cold snare while 95 polyps (mean size 5.5±6 mm) were resected with hot snare polypectomy. Twenty-four new polyps (<5 mm) were found at follow-up. No polypectomy scars were detected in the vicinity of the new polyps. The prevalence of new polyps was similar (i.e., cold vs. hot snare polypectomy; 23% vs. 19%, P=0.68). Multivariate analysis revealed that the removal of ≥4 polyps was an independent predictor associated with new polyps (odds ratio:7.8, 95% confidence interval: 2.1-32, P=0.0022). CONCLUSIONS: Diminutive polyps were newly found with similar prevalence after cold or hot snare polypectomy, but there were no recurrent polyps detected.

[Clinical study of the combination of small amount of nedaplatin (CDGP)/5-FU with radiation for the treatment of esophageal cancer].

Recently chemoradiotherapy for esophageal cancer has been drawing public attention to the issue of quality of life maintenance for patients. Although the standard method of chemoradiotherapy is CDDP/5FU, it has been claimed that CDGP (a derivative of CDDP) alone is more effective than CDDP for the treatment of esophageal cancer due to its low nephro- and digestive toxicity. We used a small amount of CDGP/5-FU in combination with radiation instead of CDDP, for the treatment of esophageal cancer and performed clinical examination of patients. The partial response rate was 80% and the complete response rate was 50%. Major side-effects were leukopenia, neutropenia, thrombocytopenia and anemia. Further study of dosage and schedule is necessary, however, CDGP/5-FU combined with radiation therapy could be used as choices of chemoradiotherapy for esophageal cancer in the future.

Safety and effectiveness of propofol sedation during and after outpatient colonoscopy.

AIM: To study the safety and effectiveness of propofol sedation for outpatient colonoscopy. METHODS: Propofol was given by bolus injection with an age-adjusted standard protocol consisting of 60 mg for patients < 70 years old, 40 mg for patients age 70-89 years, and 20 mg for those ≥ 90 years, and additional injections of 20 mg propofol were given up to a maximum of 200 mg. The principal parameters were the occurrence of adverse events within 24 h after colonoscopy and overall satisfaction for this procedure. Secondary parameters included successful procedure, respiratory depression, and other complications. RESULTS: Consecutive patients were entered prospectively and all 2101 entered successfully completed outpatient colonoscopy. The mean dose of propofol used was 96.4 mg (range 40-200 mg). Younger patients required higher doses of propofol than older patients (20-40 years vs ≥ 61 years: 115.3 ± 32 mg vs 89.7 ± 21 mg, P < 0.001). Transient supplemental oxygen supply was needed by five patients (0.2%); no other complications occurred. The questionnaires were completed by 1820 (87%) of 2101 patients and most rated their overall satisfaction as excellent (80%) or good (17%). The majority (65%) of patients drove home or to their office after their colonoscopy. Most (99%) were willing to repeat the same procedure. No incidents occurred within 24 h after colonoscopy. CONCLUSION: Propofol sedation using a dose < 200 mg proved both safe and practical for outpatient colonoscopy.

Safer endoscopic gastric mucosal resection: preoperative proton pump inhibitor administration.

BACKGROUND AND AIM: Control of bleeding is crucial in improving the safety of endoscopic mucosal resection (EMR), and intragastric acidity has a great impact on hemostasis and blood coagulation. Proton pump inhibitors (PPI) are potent suppressors of gastric acid; however, PPI need to be continuously administered orally for several days, and thus initial effects may be insufficient if PPI is only administered immediately after EMR. The aim of this study was to determine whether preoperative administration of PPI prior to EMR can elevate intragastric acidity, facilitate better control of intraoperative bleeding (complete coagulation and hemostasis), prevent postoperative bleeding, and facilitate healing of artificial ulcers. METHODS: A randomized clinical study was conducted in which EMR was performed with or without 1 week of preoperative PPI administration. RESULTS: Artificial ulcers created by EMR healed more rapidly in patients who received preoperative PPI. CONCLUSIONS: The results of the study suggest that preoperative administration of PPI before EMR is useful for controlling and preventing bleeding, and for facilitating the healing of artificial ulcers.

One-milliliter wet-digestion for inductively coupled plasma mass spectrometry (ICP-MS): determination of platinum-DNA adducts in cells treated with platinum(II) complexes.

Platinum (Pt)-DNA adducts formed by the anti-tumor agent cisplatin are recognized by the DNA mismatch repair (MMR) system. To investigate the involvement of MMR proteins including hMLH1 in the removal of these adducts, we developed a mL-scale wet-digestion method for inductively coupled plasma mass spectrometry (ICP-MS). The detection limit was 0.01 ng mL(-1) Pt, which corresponded to 2 pg Pt/microg DNA when 10 microg of DNA was used. The mean relative errors were 5.4% or better for a dynamic range of 0.01-10 ng mL(-1) Pt. DNA (approximately 500 microg) had no matrix effect. To improve the accuracy, DNA preparations were treated with ribonuclease and the apparent reduction in the concentration of Pt was corrected using cellular DNA levels, which were determined with Hoechst 33258. No significant differences were observed, in terms of the formation of Pt-DNA adducts or their removal over 6 h, between hMLH1-deficient HCT116 cells, a human colorectal cancer cell line, and hMLH1-complemented HCT116+ch3 cells (n=5; P>0.05), indicating that the hMLH1-dependent DNA repair systems contribute to neither the formation nor the removal of the adducts at detectable levels. In addition, approximately 19% of the adducts were removed within 6 h in both cell lines. A time course analysis (~24 h) suggested that the removal of cisplatin-generated Pt-DNA adducts follows first-order kinetics (t(1/2)=32 h). The amount of Pt-DNA adduct formed by oxaliplatin in 1 h was 56% (ratio of means) of that generated by an equimolar concentration of cisplatin in HCT116. The proposed procedure could be useful for determining Pt-DNA adducts formed by Pt(II) complexes.

Factors influencing survival of Legionella pneumophila serotype 1 in hot spring water and tap water.

The factors involved in the survival of Legionella pneumophila in the microcosms of both hot spring water and tap water were studied by examining cultivability and metabolic activity. L. pneumophila could survive by maintaining metabolic activity but was noncultivable in all microcosms at 42 degrees C, except for one microcosm with a pH of <2.0. Lower temperatures supported survival without loss of cultivability. The cultivability declined with increasing temperature, although metabolic activity was observed at temperatures of up to 45 degrees C. The optimal range of pH for survival was between 6.0 and 8. The metabolic activity could be maintained for long periods even in microcosms with high concentrations of salt. The cultivability of organisms in the post-exponential phase in a tap water microcosm with a low inoculum size was more rapidly reduced than that of organisms in the exponential phase. In contrast, the loss of cultivability in microcosms of a high inoculum size was significant in the exponential phase. Random(ly) amplified polymorphic DNA analysis of microcosms where cultivability was lost but metabolic activity was retained showed no change compared to cells grown freshly, although an effect on the amplified DNA band pattern by production of stress proteins was expected. Resuscitation by the addition of Acanthamoeba castellanii to the microcosm in which cultivability was completely lost but metabolic activity was maintained was observed only in part of the cell population. Our results suggest that L. pneumophila cell populations can potentially survive as free organisms for long periods by maintaining metabolic activity but temporarily losing cultivability under strict environments and requiring resuscitation by ingestion by amoebas.