Discovery of Surfactant-Like Peptides from a Phage-Displayed Peptide Library.

Peptides with specific affinities for various materials have been identified in the past three decades and utilized in materials science and engineering. A peptide's capability to specifically interact with materials is not naturally derived but screened from a biologically constructed peptide library displayed on phages or cells. To date, due to limitations in the screening procedure, the function of screened peptides has been primarily limited to the affinity for target materials. Herein, we demonstrated the screening of surfactant-like peptides from a phage-displayed peptide library. A screened phage clone displaying a peptide showed high activity for accumulating at emulsion surfaces with certain assembled structures, resulting in stable emulsions. The surface tension for the solution of the chemically synthesized peptide decreased with increasing peptide concentration, demonstrating certain surface activity, which corresponded to the ability to decrease the surface tension of liquids (e.g., water), owing to the accumulation of molecules at the air-liquid or liquid-liquid interface. Peptides with a randomized sequence did not lower the surface tension, indicating the essential role of amino acid sequences in surface activity. Our strategy for identifying novel functional peptides from a phage-displayed peptide library can be used to expand the applicability of peptidyl materials and biosurfactants.

Absorbable barbed suture device for laparoscopic peritoneal closure after hernia repair via the transabdominal preperitoneal approach: A single-center experience with 257 cases.

INTRODUCTION: The laparoscopic transabdominal preperitoneal approach requires peritoneal closure and technically skilled knotting. We have started to use a barbed running suturing device (V-Loc 180) without knotting for transabdominal preperitoneal repair of hernias. This study aimed to determine whether using V-Loc 180 was safe and shortened the time for laparoscopic peritoneal closure. METHODS: Between December 2010 and February 2017, 3-0 V-Loc 180 and a multifilament absorbable running suture (3-0 Vicryl) were used for three-port transabdominal preperitoneal repair of inguinal hernia in 363 cases. Data including peritoneal closure time and the complications were retrospectively recorded. RESULTS: Factors identified as significantly prolonging the peritoneal closure time were the hernia side (P = 0.0269), the type of hernia (P = 0.001), the suture device used (P < 0.0001), and the surgeon's experience (P < 0.0001). Use of the barbed suture was associated with a significantly shorter peritoneal closure time than the multifilament suture (mean closure time: 10.2 and 12.7 min, respectively). While there were no postoperative complications in the barbed suture group, there were two cases (1.9%) of postoperative complications in the multifilament suture group (P = 0.0272). CONCLUSION: We demonstrated that the use of the barbed suturing device for laparoscopic peritoneal closure was safe and feasible.

Single-incision laparoscopic cholecystectomy with an additional needle grasper: a novel technique.

BACKGROUND: Single-incision laparoscopic surgery has gained increasing attention due to its potential to improve the benefits of laparoscopic surgery. However, the technique remains technically challenging for most surgeons. We developed a new technique utilizing a needle grasper held in the surgeon's left hand as an alternative to conventional single-incision laparoscopic cholecystectomy (SILC). PATIENTS AND METHODS: From August 2011 through May 2013, 29 patients at Nippon Medical School Musashi Kosugi Hospital, with gallbladder stones or polyps underwent single-incision laparoscopic cholecystectomy (SILC) with an additional needle grasper that was held in the surgeon's left hand (SILCAN) and introduced in the right subcostal region without a trocar. We analyzed intraoperative and postoperative outcomes of 29 patients for whom SILCAN was performed and retrospectively compared these outcomes to those of 32 patients who underwent conventional 4-port laparoscopic cholecystectomy (CLC) from January 2011 through May 2013. RESULTS: No differences in patient characteristics or intraoperative/postoperative outcomes were observed between the groups. None of the patients in either group required conversion to an open procedure or additional ports. In the SILCAN group, no patients had complications within the first 4 weeks after surgery, with the exception of 1 patient with severe chronic cholecystitis in whom bile duct stenosis developed due to inadvertent clipping of the common hepatic duct. The frequency of postoperative analgesic use was similar in both groups, although none of the patients in the SILCAN group received analgesics for pain from the small, inconspicuous wound in the right subcostal region. CONCLUSIONS: SILCAN is a safe and feasible alternative to SILC which does not compromise the qualities of CLC. It is less technically challenging, and postoperative pain and cosmesis are comparable to those of conventional SILC.

A case of nonfunctioning pancreatic endocrine tumor with atypical imaging findings due to prominent fibrosis of the tumor stroma.

The patient, a 56-year-old woman, was found during routine checkup to have a disorder of hepatic function. Abdominal ultrasonography showed an ill-defined hypoechoic mass in the head and body of the pancreas; however, no blood-flow signal was observed within the tumor on Doppler ultrasonography. Abdominal computed tomography showed a low-density area in the arterial and portal venous phases. The lesion was visualized as an area of low signal intensity on both T1- and T2-weighted magnetic resonance images, whereas fluorodeoxyglucose positron emission tomography showed fluorodeoxyglucose accumulation in the tumor. Although a preoperative diagnosis was difficult to make, a rapid cytologic examination revealed evidence of a pancreatic endocrine tumor, and subtotal stomach-preserving pancreaticoduodenectomy with portal vein resection was performed. Histopathological examination showed tumor cell nests scattered in abundant fibrotic tissue; the tumor cells had proliferated in a cord-like fashion and showed immunostaining for chromogranin A. Staining for fibroblast activation protein α was seen in the fibroblastic cells contained within the fibrous stroma surrounding the tumor cell nests, whereas both the fibroblastic cells in the tumor and those in the stroma showed a high rate of staining for thrombospondin. We presume that tumor-associated fibroblasts were involved in the fibrosis of the tumor stroma.