[Application of ureteral access sheath in the operation of middle and lower ureteral calculi in patients with massive benign prostatic hyperplasia].

Objective: To examine the effectiveness and safety of application of the ureteral access sheath in the treatment of middle or lower ureteral calculi in patients with large-volume benign prostatic hyperplasia above grade Ⅲ, which is expected to avoid the simultaneous or staged treatment of benign prostatic hyperplasia via eliminate the difficult angle and resistance of ureteroscopy caused by severe prostatic hyperplasia. Methods: From April 2018 to December 2020, the clinical data of 27 patients with massive benign prostatic hyperplasia above grade Ⅲ and middle and lower ureteral calculi treated with indwelling ureteral access sheath plus ureteroscopy holmium laser lithotripsy at Department of Urology, Zhejiang Quhua Hospital were retrospectively analyzed and followed up. All the patients were male, aged (69.7±12.8) years (range: 55 to 87 years). Prostate volume measured by transrectal ultrasound was (94.8±16.2) cm3 (range: 85 to 186 cm3). The ureteral access sheath was indwelled in advance, and then the semirigid ureteroscopy was introduced through the working channel of the sheath. Holmium laser lithotripsy was performed, and intraoperative and postoperative complications were recorded. Urinary abdominal plain X-ray or CT urography were performed at 1-and 2-month postopaerative to evaluate the residual stones and clinical efficacy. Results: The ureteral access sheath was placed and holmium laser lithotripsy under a semirigid ureteroscopy was performed successfully in all the 27 patients. In 2 patients, a second session of auxiliary procedure was required due to the large load of preoperative stones and residual stones after surgery, among whom 1 patient received extracorporeal shock wave lithotripsy and 1 patient underwent extracorporeal shock wave lithotripsy plus ureteroscopic lithotripsy. The stone free rate at 1-and 2-month postoperative were 92.6% (25/27) and 100% (27/27), respectively. There were no severe complications such as ureteral avulsion and perforation, perirenal hematoma, septic shock, severe hematuria, urinary retention, iatrogenic ureteral stricture occurred during and after the surgery. The ureteral calculus was wrapped by polyps heavily in 1 patient, he was diagnosed as ureteral stenosis 1 month postoperative, receiving laparoscopic resection of ureteral stricture plus anastomosis 3 months postoperative. Conclusions: In the operations of middle and lower ureteral calculi in patients with large-volume prostatic hyperplasia above grade Ⅲ, the ureteral access sheath can be placed first to effectively eliminate the difficult angle and resistance of ureteroscopy caused by severe prostatic hyperplasia, and then semirigid ureteroscopic lithotripsy can be safely performed. It could avoid the treatment of benign prostatic hyperplasia at the same time or by stages.

Promoter mutation of tumor suppressor microRNA-7 is associated with poor prognosis of lung cancer.

The significance of promoter mutations of microRNAs (miRNAs) in lung cancer is poorly understood. Recent evidence demonstrated that miRNA-7 (miR-7), a unique member of the miRNA family, exhibited decreased expression and has emerged as an important regulator in lung tumorigenesis. However, the mechanism underlying the downregulation of miR-7 in lung cancer remains largely unknown. In this study, we investigated the sites of mutation of the miR-7 promoter in lung cancer tissues using DNA sequencing. We identified a G→C change at the -617 site (25/39, 64.1%) and an A→G change at the -604 site (20/39, 51.3%) in the miR-7 promoter region in lung cancer tissues. Moreover, the expression of miR-7 in cancer tissue with promoter site mutations was lower compared with that in cancer tissue without mutations (P<0.05). Furthermore, we demonstrated that mutations at these sites may decrease the activity of the miR-7 promoter and alter the expression of miR-7. Notably, mutations at these sites of the miR-7 promoter were found to be closely associated with poor prognosis of lung cancer patients (P=0.037). These data may provide novel insight on the altered expression of specific miRNA molecules in lung cancer and ultimately prove to be helpful in the development of prognostic and therapeutic strategies against lung cancer.

Evaluation of the purity of recombinant proteins and detection of residual protein contaminants via N-terminal microsequencing and database searching.

The N-terminal amino acid sequences of purified recombinant human gamma-interferon, alpha 2a-interferon and interleukin-2 expressed in E. coli were determined on an Applied Biosystems 477A Protein/Peptide Sequencer and 120A PTH Amino Acid Analyzer. From the raw chromatographic data of these samples, the identity, heterogeneity, amount of methionine-plus species remaining in the final products, and the probable process contaminants were evaluated with the help of computer methods including database searching. General methods to characterize trace contaminants in protein samples were also discussed. Among the sequenced samples, only gamma-interferon was shown to be N-terminal homogeneous. Methionine-containing species were found in interleukin-2 and alpha 2a-interferon. Chicken eggwhite lysozyme was detected in very small amounts in one batch of samples. These results provide valuable information for the development and improvement of preparation methods as well as regulatory responses to recombinant products.