Piperlongumine-Eluting Gastrointestinal Stent Using Reactive Oxygen Species-Sensitive Nanofiber Mats for Inhibition of Cholangiocarcinoma Cells

BACKGROUND

The aim of this study is to fabricate drug-eluting gastrointestinal (GI) stent using reactive oxygen species (ROS)-sensitive nanofiber mats for treatment of cholangiocarcinoma (CCA) cell. A ROS-producing agent, piperlongumine (PL)-incorporated nanofiber mats were investigated for drug-eluting stent (DES) application.

METHODS

Selenocystamine-conjugated methoxy poly(ethylene glycol) (MePEG) was conjugated with poly(L-lactide) (PLA) to produce block copolymer (LEse block copolymer). Various ratios of poly(ε-caprolactone) (PCL) and LEse block copolymer were dissolved in organic solvent with PL, and then nanofiber mats were fabricated by electro-spinning techniques.

RESULTS

The higher amount of LEse in the blend of PCL/LEse resulted in the formation of granules while PCL alone showed fine nanofiber structure. Nanofiber mats composed of PCL/LEse polymer blend showed ROS-sensitive drug release, i.e., PL release rate from nanofiber mats was accelerated in the presence of hydrogen peroxide (H₂O₂) while nanofiber mats of PCL alone have small changes in drug release rate, indicating that PL-incorporated nanofiber membranes have ROS responsiveness. PL itself and PL released from nanofiber mats showed almost similar anticancer activity against various CCA cells. Furthermore, PL released from nanofiber mats properly produced ROS generation and induced apoptosis of CCA cells as well as PL itself. In HuCC-T1 cell-bearing mice, PL-incorporated nanofiber mats showed improvement in anticancer activity.

CONCLUSION

PL-incorporated ROS-sensitive nanofiber mats were coated onto GI stent and showed improved anticancer activity with ROS responsiveness. We suggested PL-incorporated ROS-sensitive nanofiber mats as a promising candidate for local treatment of CCA cells.

Gastric squamous papilloma in a 52-year-old female patient

A papilloma is a benign epithelial lesion characterized by finger-like projections of tissue lined by an overgrowth of squamous cells and a core of connective tissue. We report a case of squamous papilloma on the cardia in a 52-year-old asymptomatic female. Endoscopy showed a 1-cm sized is polyp with hyperemic change originating from the cardia adjacent to the esophagogastric junction, the biopsy of which suggested a diagnosis of squamous papilloma. Endoscopic mucosal resection was performed to obtain a definite diagnosis and the polyp was completely removed. The histological result was compatible with squamous papilloma, and its surrounding tissues showed foveolar epithelium, which suggested a stomach origin. This is the first report of endoscopic resection of a gastric squamous papilloma. Squamous papilloma should be considered in the differential diagnosis of a gastric polyp, especially one in the cardia. As the prognostic value of a squamous papilloma is not well known, we recommend endoscopic resection to treat a gastric squamous papilloma, when possible.

Importance of the time interval between bowel preparation and colonoscopy in determining the quality of bowel preparation for full-dose polyethylene glycol preparation

Background/Aims

The quality of bowel preparation (QBP) is the important factor in performing a successful colonoscopy. Several factors influencing QBP have been reported; however, some factors, such as the optimal preparation-to-colonoscopy time interval, remain controversial. This study aimed to determine the factors influencing QBP and the optimal time interval for full-dose polyethylene glycol (PEG) preparation.

Methods

A total of 165 patients who underwent colonoscopy from June 2012 to August 2012 were prospectively evaluated. The QBP was assessed using the Ottawa Bowel Preparation Scale (Ottawa) score according to several factors influencing the QBP were analyzed.

Results

Colonoscopies with a time interval of 5 to 6 hours had the best Ottawa score in all parts of the colon. Patients with time intervals of 6 hours or less had the better QBP than those with time intervals of more than 6 hours (p=0.046). In the multivariate analysis, the time interval (odds ratio, 1.897; 95% confidence interval, 1.006 to 3.577; p=0.048) was the only significant contributor to a satisfactory bowel preparation.

Conclusions

The optimal time was 5 to 6 hours for the full-dose PEG method, and the time interval was the only significant contributor to a satisfactory bowel preparation.

[A case of tuberculous liver abscess developed during chemotherapy for tuberculous peritonitis as paradoxical response]

Tuberculous liver abscesses are rare. Paradoxical response in tuberculosis is common and occurred between 2 weeks and 12 weeks after anti-tuberculous medication. We report here a case of tuberculous liver abscess that developed in a paradoxical response during chemotherapy for tuberculous peritonitis in a 23-year-old male. He was hospitalized, complaining of ascites, epigastric pain. He was diagnosed tuberculous peritonitis by expiratory laparoscopic biopsy and took medication for tuberculosis. After 2 months, a hepatic lesion was detected with CT scan incidentally. Chronic granulomatous inflammation was seen in ultrasound-guided liver biopsy, and tuberculous liver abscess was diagnosed. It was considered as paradoxical response, rather than treatment failure or other else because clinical symptoms of peritoneal tuberculosis and CT scan improved. After continuing initial anti-tuberculous medication, he was successfully treated. Herein, we report a case of tuberculous liver abscess as paradoxical response while treating peritoneal tuberculosis without changing anti-tuberculous treatment regimen.

Rice 1Cys-peroxiredoxin over-expressed in transgenic tobacco does not maintain dormancy but enhances antioxidant activity

Possible functions that have been proposed for the plant 1Cys-peroxiredoxin, include activity as a dormancy regulator and as an antioxidant. The transcript level of rice 1Cys-peroxiredoxin (R1C-Prx) rapidly decreased after imbibition of rice seeds, but the protein was detected for 15 days after imbibition. To investigate the function of this protein, we generated transgenic tobacco plants constitutively expressing the R1C-Prx gene. The transgenic R1C-Prx plants showed a germination frequency similar to control plants. However, the transgenic lines exhibited higher resistance against oxidative stress, suggesting that antioxidant activity may be its primary function.