A novel artificial anal sphincter system in an in vitro and in vivo experiment.

This paper presents some of the latest progress in the development of a novel artificial anal sphincter system (AASS) to treat severe fecal incontinence. We have redesigned and integrated an intelligent, remote-controlled artificial anal sphincter based on biological signal feedback mechanisms. The device consists of an external telemetry unit, an internal artificial anal sphincter (IAAS), and a transcutaneous energy transfer system (TETS). The mechanical medical micropump of the IAAS can realize bidirectional flow with a maximum flow rate of 8.5 ml/min and can build backpressure up to 170 kPa. The design of the prosthesis reduces occlusion pressure and allows for low inflation volumes (9 mL-10.5 mL); operating pressures between 4.05 kPa and 7.16 kPa indicate that the risk of ischemic injury to the bowel is minimal. Furthermore, the rechargeable battery based on TETS puts the operation time at an estimated 2 days. The performance characteristics of the AASS and its efficiency in achieving continence and sensing the stool inside the anorectum were evaluated in vitro and in vivo in a pig model. Experimental results confirm that the system can maintain continence and build the sense of defecation successfully. Moreover, this innovation can be integrated into not only severe fecal incontinence, erectile dysfunction, and therapy-resistant reflux disease, but also morbid adiposity therapeutic AASS applications.

Effect of parenteral and early intrajejunal nutrition on pancreatic digestive enzyme synthesis, storage and discharge in dog models of acute pancreatitis.

AIM: To study the effect of early intrajejunal nutrition on enzyme-protein synthesis and secretion during acute pancreatitis. METHODS: Fifteen dogs were randomly divided into parenteral nutrition (n = 7) and early intrajejunal nutrition groups (n = 8). An acute pancreatitis model was induced by injecting 5% sodium taurocholate and trypsin into the pancreas via the pancreatic duct. Intrajejunal nutrition was delivered with a catheter via a jejunostomy tube after the model was established for 24 h. On d 1 and 7 and at the beginning of nutritional support, radioactive tracing and electron microscopes were used to evaluate the enzyme-protein synthesis in acinar cells, the subcellular fractionation and the change in zymogen granules after 1.85 x 10(6) Bq L-(3)H phenylalanine was infused at 30, 60, 120, and 180 min. RESULTS: The 3H radioactivity in pancreatic acinar cells reached its peak level at 60 min, and the contents in the early intrajejunal nutrition group were higher than those in the parenteral nutrition group, which were then decreased. The mean number and area of zymogen granules did not show any significant statistical difference in both groups on d 1 or on d 7 (P > 0.05). CONCLUSION: Early intrajejunal nutrition might be effective in dogs with acute pancreatitis.

Restenosis following balloon dilation of benign esophageal stenosis.

AIM: To elucidate the mechanism of restenosis following balloon dilation of benign esophageal stenosis. METHODS: A total of 49 rats with esophageal stenosis were induced in 70 rats using 5 ml of 50% sodium hydroxide solution and the double-balloon method, and an esophageal restenosis (RS) model was developed by esophageal stenosis using dilation of a percutaneous transluminal coronary angioplasty (PTCA) balloon catheter. These 49 rats were divided into two groups: rats with benign esophageal stricture caused by chemical burn only (control group, n=21) and rats with their esophageal stricture treated with balloon catheter dilation (experimental group, n=28). Imaging analysis and immunohistochemistry were used for both quantitative and qualitative analyses of esophageal stenosis and RS formation in the rats, respectively. RESULTS: Cross-sectional areas and perimeters of the esophageal mucosa layer, muscle layer, and the entire esophageal layers increased significantly in the experimental group compared with the control group. Proliferating cell nuclear antigen (PCNA) was expressed on the 5th day after dilation, and was still present at 1 month. Fibronectin (FN) was expressed on the 1st day after dilation, and was still present at 1 month. CONCLUSION: Expression of PCNA and FN plays an important role in RS after balloon dilation of benign esophageal stenosis.

Parenteral versus early intrajejunal nutrition: effect on pancreatitic natural course, entero-hormones release and its efficacy on dogs with acute pancreatitis.

AIM: To evaluate the effect of early intrajejunal nutrition (EIN) on the natural course, entero-hormone secretion and its efficacy on dogs with acute pancreatitis. METHODS: An acute pancreatitis model was induced by injecting 1 ml/kg of combined solution (2.5% sodium taurocholate and 8,000-10,000 BAEE units trypsin/ml) into the pancreas via pancreatic duct. Fifteen dogs were divided into parenteral nutrition (PN) group and EIN group. Two groups were isonitrogenous and isocaloric. EIN was used at postoperative 24 h. Serum glucose, calcium, amylase and lysosomal enzymes were determined before and 1, 4, 7 d after acute pancreatitis was induced. All the dogs were injected 50 uCi 125I-BSA 4 h before sacrificed on the 7th day. The 125I -BSA index of the pancreas/muscle, pancreas/blood, and pancreas pathology score (PPS) were determined. The peripheral plasma cholecystokinin (CCK), secretin (SEC) and gastrin were measured by ELISA and RIA, and was quantitative analysis of pancreatic juice and amylase, pancreatolipase and HCO3-, Cl-, Na+ and K+ performed by an autochemical analyzer at 30, 60, 120 and 180 min after beginning PN or EIN on the first day. RESULTS: There was no difference between two groups in the contents of serum calcium, amylase and lysosomal enzymes, 125I-BSA index of pancreas/muscle and pancreas/blood and PPS. The contents of CCK and gastrin in EIN were higher than those in PN group at 60 and 120 min (P<0.05). The content of SEC post-infusion of nutrition solution was higher than that of pre-infusion of nutrition solution in both groups, and only at 60 min SEC in EIN group was higher than that in PN group. The content of gastrin in EIN was higher than that in PN group at 120 and 180 min (P<0.05). The changes of pancreatic juice, amylase, pancreatolipase and HCO3-, Cl-, Na+ and K+ between two groups did not reach significantly statistical difference (P>0.05). CONCLUSION: EIN does not stimulate entero-hormone and pancreatic juice secretion, and enzyme-protein synthesis and release. EIN has no effect on the natural course of acute pancreatitis.

[Effects of enteral nutrition on uptake of amino acid and enzyme-protein synthesis of pancreatic acinar cell in acute pancreatic dogs].

OBJECTIVE: To evaluate the effect of intrajejunal nutrition on uptake of amino acid and enzyme-protein synthesis in pancreatic acinar cell and subcellular fractionation and zymogen granules in dogs with acute pancreatitis. METHODS: Fifteen dogs were induced acute pancreatitis by retrograde injection of 5% sodium-taurocholate into the pancreatic duct. Radioactive tracing and electron microscope were used to evaluate the change of amino acid uptake, enzyme-protein synthesis in acinar cell, subcellular fractionation, the quantitative analysis of mean zymogen granule number and mean zymogen granule area after injection L-(3)H-phenylalanine 30, 60, 120 1nd 180 min on the 7(th) day. RESULTS: The radioactivity of L-(3)H phenylalanine uptake by pancreatic acinar cells and incorporations of L-(3)H phenylalanine into newly synthesized enzyme-protein peaked at 60 min. In enteral nutrition (EN) group it was higher that that in parenteral nutrition (PN) group (P < 0.05), and then gradually declined. The radioactivity peaked at 60 min in zymogen granule, lysosomal-mitochondria and microsomal subcellular fractionation. The latter two decreased, bat there was no significant difference (P > 0.05). The change of the mean number and mean area of zymogen granules were not significant different between the EN group and PN group (P > 0.05). CONCLUSION: EN or PN do not stimulate pancreatic acinar uptake amino acid and enzyme-protein synthesis in acinar cell and subcellular fractionation.