Successful treatment of recurrent cholangitis by constructing a hepaticojejunostomy with long Roux-en-Y limb in a long-term surviving patient after a Whipple procedure for pancreatic adenocarcinoma.

PubMed

Tsalis, Konstantinos; Antoniou, Nikolaos; Koukouritaki, Zambia; Patridas, Dimitrios; Sakkas, Leonidas; Kyziridis, Dimitrios; Lazaridis, Charalampos

2014-08-20

Female, 74. Recurrent cholangitis. -. -. -. Gastroenterology and Hepatology. Unusual clinical course. Cholangitis may result from biliary obstruction (e.g., biliary or anastomotic stenosis, or foreign bodies) or occur in the presence of normal biliary drainage. Although reflux of intestinal contents into the biliary tree after hepaticojejunostomy appears to be a rare complication, it is important to emphasize that there are few available surgical therapeutic techniques. A 74-year-old woman presented to our hospital after 17 years of episodes of cholangitis. The patient had undergone a pancreatoduodenectomy (Whipple procedure) 18 years earlier due to pancreatic adenocarcinoma. The reconstruction was achieved through the sequential placement of pancreatic, biliary, and retrocolic gastric anastomosis into the same jejunal loop. The postoperative course was uneventful and the patient received adjuvant chemotherapy. Approximately 6 months after the initial operation, the patient started having episodes of cholangitis. Over the next 17 years she experienced several febrile episodes presumed to be secondary to cholangitis. A computing tomography (CT) scan of the abdomen revealed intrahepatic bile ducts partially filled with orally administered contrast material (Gastrografin). Magnetic resonance cholangiopancreatography (MRCP) showed dilatation of the left intrahepatic bile ducts. A percutaneous transhepatic cholangiography showed that the bilioenteric anastomosis was normal, without stenosis. Based on these findings, a diagnosis of a short loop between the hepaticojejunostomy and the gastrojejunostomy permitting the reflux of intestinal juice into the biliary tree was made. During the re-operation, a new hepaticojejunal anastomosis in a 100-cm long Roux-en-Y loop was performed to prevent the reflux of the intestinal fluid into the biliary tree. The patient was discharged on postoperative day 10. One year after the second procedure, the patient enjoys good health and has been free of fever and abdominal pain and has not received any antibiotic therapy. Lengthening the efferent Roux-en-Y limb should be considered as a therapeutic option when treating a patient with recurrent episodes of cholangitis after hepaticojejunostomy.

Rejection of isolated pancreatic allografts in patients with with diabetes.

PubMed

Groth, C G; Lundgren, G; Arner, P; Collste, H; Hårdstedt, C; Lewander, R; Ostman, J

1976-12-01

Four patients with diabetes mellitus of juvenile onset but without uremia have been treated with segmental transplantation of the body and tail of pancreas. The indications were hyperlabile diabetes or progressive loss of vision. The grafts were procured from cadaveric donors four to 16 minutes after circulary arrest and were subsequently stored in the cold for approximately four hours. In one patient, the pancreatic duct was ligated, while in the other three, drainage was attained by suturing the transected end of the pancreas into a jejunal Roux-en-Y loop. Three of the grafts failed within six weeks as a result of irreversible refection, and one graft failed because of the early onset of venous thrombosis. The first sign of graft rejection was an increase in the postprandial blood sugar level, an increase in the fasting blood sugar level occurring several days later. Neither hyperamylasemia nor fever was observed. Radioisotope scans and angiograms were of great value in establishing the diagnosis of graft rejection. All of the patients survived after graft removal.

Post-cholecystectomy biliary injuries: one center experience.

PubMed

Fathy, Omar; Wahab, Mohamed Abdel; Hamdy, Emad; Elshoubary, Mohamed; Kandiel, Tharwat; Elraof, Ahmad Abd; Elhemaly, Mohamed; Salah, Tarek; Elhanafy, Ehab; Atef, Ehab; Sultan, Ahmad Mohamed; Elebiedy, Gamal; Anwar, Nabieh; Sultan, Ahmad

2011-01-01

Post-cholecystectomy bile duct injuries (BDIs) represent a challenge in diagnosis and management. From March 1995 to August 2009, 274 patients with post-cholecystectomy BDIs were managed at our center. All patients were subjected to laboratory tests, sonography, ERCP and MRCP. The management varied according to the type of injury. Seventy-one (25.9%) LC and 203 (74.1%) OC were performed; 8(2.9%) were detected intraoperatively; 270 patients were referred from other hospitals. From those discovered intraoperatively, 7 had hepatico-jejunostomy and one died from severe peritonitis; 11 (4%) presented with generalized and 112 (40.9%) with localized peritonitis. The leak site was the cystic duct (57 cases), accessory duct in the liver bed (5 cases), right hepatic duct (4 cases) and lateral tear in the CBD (12 cases). Endoscopic stenting was performed for all of them. The remaining 34 patients had a completely ligated distal duct and therefore had hepatico-jejunostomy Roux loop; 143 patients (52.2%) presented with early (79 cases) and late (64 cases) jaundice; 126 cases had hepatico-jejunostomy. The remaining 17 patients were treated by balloon dilatation. Endoscopic stenting can manage cases with cystic or accessory duct leak while, hepatico-jejunostomy Roux loop represents the golden procedure for management of transected or ligated CBD.

[Comparison of the safety and the costs between laparoscopic assisted or totally laparoscopic uncut Roux-en-Y and BillrothII(+Braun reconstruction--a single center prospective cohort study].

PubMed

Wang, Yinkui; Li, Ziyu; Shan, Fei; Zhang, Lianhai; Li, Shuangxi; Jia, Yongning; Chen, Yufan; Xue, Kan; Miao, Rulin; Li, Zhemin; Gao, Xiangyu; Yan, Chao; Li, Shen; Wu, Zhouqiao; Ji, Jiafu

2018-03-25

To compare the short-term safety and costs between laparoscopic assisted or totally laparoscopic uncut Roux-en-Y and Billroth II((BII() + Braun reconstruction after radical gastrectomy of distal gastric cancer. Clinical data from our prospective database of radical gastrectomy were systematically analyzed. The patients who underwent laparoscopic gastrectomy with uncut Roux-en-Y or BII(+ Braun reconstruction between March 1st, 2015 and June 30th, 2017 were screened out for further analysis. Both the reconstructions were completed by linear staplers. Uncut Roux-en-Y reconstruction was performed with a 45 mm no-knife linear stapler (ATS45NK) on the afferent loop below the gastrojejunostomy. Continuous variables were compared using independent samples t test or Mann-Whitney U. The frequencies of categorical variables were compared using Chi-squared or Fisher exact test. Eighty-one patients were in uncut Roux-en-Y group and 58 patients were in BII(+Braun group. There were no significant differences between uncut Roux-en-Y group and BII(+Braun group in median age (56.0 years vs. 56.5 years, P=0.757), gender (male/female, 52/29 vs. 46/12, P=0.054), history of abdominal surgery (yes/no, 10/71 vs. 4/54, P=0.293), neoadjuvant chemotherapy (yes/no, 21/60 vs. 11/47, P=0.336), BMI (thin/normal/overweight/obesity, 2/49/26/3 vs. 3/39/14/2, P=0.591), NRS 2002 score (1/2/3/4, 58/15/5/3 vs. 47/5/3/3, P=0.403), pathological stage (0/I(/II(/III(, 3/41/20/17 vs. 1/28/13/16, P=0.755), median tumor diameter in long axis (2.5 cm vs. 3.0 cm, P=0.278), median tumor diameter in short axis (2.0 cm vs. 2.0 cm, P=0.126) and some other clinical and pathological characteristics. There were no significant differences between uncut Roux-en-Y group and BII(+Braun group in morbidity of postoperative complication more severe than grade I([12.3% (10/81) vs. 17.2% (10/58), P=0.417], morbidity of anastomotic complication [1.2%(1/81) vs. 0, P=1.000] or hospitalization costs [(94000±14000) yuan vs.(95000±16000) yuan, P=0.895]. The median first time to liquid diet (57.1 hours vs. 70.8 hours, P=0.017) and median postoperative hospital stay (9 days vs. 11 days, P=0.003) of the patients in uncut Roux-en-Y group were shorter than those in BII(+Braun group. Laparoscopic assisted or totally laparoscopic uncut Roux-en-Y reconstruction after radical gastrectomy of distal gastric cancer is safe and feasible with better recovery than BII(+Braun reconstruction.

A new approach for Roux-en-Y reconstruction after pancreaticoduodenectomy.

PubMed

Xu, Meng; Wang, Min; Zhu, Feng; Tian, Rui; Shi, Cheng-Jian; Wang, Xin; Shen, Ming; Qin, Ren-Yi

2014-12-01

Postoperative pancreatic fistula remains the most common complication of pancreaticoduodenectomy (PD) and is potentially lethal. It contributes significantly to prolonged hospitalization and mortality. In this study, we introduced a new technical approach, a modified Roux-en-Y reconstruction and evaluated its safety and feasibility. We retrospectively reviewed the patients who had undergone PD with the modified Roux-en-Y reconstructive technique for periampullary malignancies from January 2011 to June 2012. The data on complications, hospital stay and outcomes after the modified Roux-en-Y reconstruction were analyzed. The reconstruction was performed in 171 patients, of whom 92 received pancreaticogastrostomy and 79 received pancreaticojejunostomy. The median duration of surgery was 4.0 hours (range 3.1-6.9) in all patients, and the median blood loss was 530 mL (range 200-2000). Sixty-nine patients were subjected to transfusions, with a median transfusion volume of 430 mL (range 200-1400). The median hospital stay of the patients was 14 days (range 11-38). Their operative mortality was zero and overall morbidity was 18.1% (31 patients). Only four patients (2.3%) developed pancreatic fistulas (grade A fistulas in two patients and grade B in two patients); no patients developed grade C fistula. None of the patients developed bile reflux gastritis. The modified Roux-en-Y reconstruction, which isolates biliary anastomosis from pancreatic, gastric or jejunal anastomosis, is a safe, reliable, and favorable technique. But it needs further investigation in randomized controlled trials.

Isolated Roux-en-Y anastomosis of the pancreatic stump in a duct-to-mucosa fashion in patients with distal pancreatectomy with en-bloc celiac axis resection.

PubMed

Okada, Ken-Ichi; Kawai, Manabu; Tani, Masaji; Hirono, Seiko; Miyazawa, Motoki; Shimizu, Atsushi; Kitahata, Yuji; Yamaue, Hiroki

2014-03-01

A pancreatic fistula is one of the most serious complications in distal pancreatectomy with en bloc celiac axis resection (DP-CAR), because the pancreatic transection is performed on the right side of the portal vein, which results in a large cross-section surface, and because post-pancreatectomy hemorrhage is hard to treat by interventional radiology. Therefore, a procedure to decrease the incidence of postoperative pancreatic fistula is urgently needed. Twenty-six consecutive patients who underwent DP-CAR between April 2008 and August 2012 were reviewed retrospectively. The first 13 consecutive patients underwent DP-CAR with no anastomosis, and the subsequent 13 consecutive patients were treated with Roux-en-Y pancreaticojejunostomy (PJ) in a duct-to-mucosa fashion. Extremely high amylase levels (>4000 IU/l) of all drainage fluid specimens on postoperative day (POD) 1, 3 and 4 were detected more frequently in cases with no anastomosis (n = 7) compared to those with PJ (n = 1) (P = 0.056). The incidence of grade B/C pancreatic fistulas was 15.4% in cases with isolated Roux-en-Y anastomosis of the pancreatic stump performed in a duct-to-mucosa fashion, and we are currently examining whether this anastomosis method reduces the pancreatic fistula rate in a multicenter, randomized controlled trial for distal pancreatectomy patients (ClinicalTrials.gov NCT01384617). © 2013 Japanese Society of Hepato-Biliary-Pancreatic Surgery.

Double-balloon endoscopy for retrograde cholangiography in patients with choledochojejunostomy and Roux-en-Y reconstruction.

PubMed

Pohl, J; May, A; Aschmoneit, I; Ell, C

2009-02-01

Choledochojejunal anastomoses with Roux-en-Y reconstruction excludes the biliary tract from conventional endoscopic retrograde cholangiography (ERC) with standard endoscopes due to the length of the interposed small bowel segment. Double-balloon enteroscopy (DBE) facilitates deep insertion into the small bowel and may be used to perform ERC in these patients. In the present case series we report our experience with diagnostic and therapeutic double-balloon ERC in patients with choledochojejunostomy to a long Roux-en-Y loop previously unavailable for standard length endoscopes. Between December 2004 and May 2008 15 patients (mean age: 60.2 years) with choledochojejunal anastomosis underwent a total of 25 DBE-ERC procedures. Cannulation of the bile ducts was achieved in 22 / 25 procedures (84 %). Twenty-one therapeutic interventions, including stone removal, biliary duct dilation, stent placement and removal of previously placed stents were performed during 16 procedures in 8 patients. The mean total duration time of the procedures was 74.6 +/- 25.0 minutes. Postinterventional self-limiting fever occurred after 4 procedures in 3 patients with cholangitis. After therapeutic interventions all patients had a significant drop of bilirubin levels and all except one patient were free of complaints (follow-up 10.4 +/- 8.6 months). The DBE system permits diagnostic and therapeutic ERC in surgically modified anatomy, previously unavailable for endoluminal access. In our experience this procedure is safe and has a high success rate with a favourable patient outcome.

Roux limb volvulus in laparoscopic Roux-en-Y gastric bypass due to Roux limb stabilization suture: case series.

PubMed

Marr, Brendan; Yenumula, Panduranga

2012-01-01

Complications after laparoscopic Roux-en-Y gastric bypass surgery may be related to the type of surgical technique employed. One technique, the placement of a Roux limb stabilization suture, presumably prevents kink at the gastrojejunal anastomosis. However, it can have an adverse effect and we studied a series of cases presenting with intestinal obstruction secondary to this stitch. A retrospective review of a prospectively collected database of laparoscopic Roux-en-Y gastric bypass cases who had reoperations for Roux limb volvulus was performed at a single bariatric center by a single surgeon. Out of 199 patients who underwent laparoscopic Roux en Y gastric bypass with placement of Roux limb stabilization suture, 4 patients (2.01%) presented with Roux limb volvulus postoperatively. BMI was 45.35 ± 2.95. The postoperative time to presentation was 11 ± 10.6 months. All four patients required surgical exploration to reduce the volvulus. In all cases, the Roux limb volvulus was directly attributable to the presence of the stabilization suture. In subsequent 250 cases where this suture was eliminated, there was no volvulus of Roux limb seen. The use of a stabilization suture can result in volvulus of the Roux limb causing intestinal obstruction and this complication can be prevented by avoiding this suture.

Laparoscopic revision of Billroth II with Braun anastomosis into Roux-en-Y anatomy in a patient with intestinal malrotation.

PubMed

Garofalo, Fabio; Abouzahr, Omar; Atlas, Henri; Denis, Ronald; Garneau, Pierre; Huynh, Hai; Pescarus, Radu

2018-01-01

Various reconstructions of the gastro-intestinal tract have been described in the past after distal gastrectomy. Among these, a Billroth II (BII) anastomosis can be performed with the addition of the Omega entero-enterostomy that may theoretically reduce the alkaline reflux. Given the significant complications associated with this procedure such as biliary reflux, marginal ulceration, and afferent loop syndrome, a revision into a Roux-en-Y anatomy is generally recommended. A 73-year-old healthy male was referred to our foregut surgery service for treatment of severe biliary gastritis. The patient previously underwent an open distal gastrectomy with a BII reconstruction followed by a Braun-type entero-enterostomy 6 months later. His main complaint was worsening daily biliary reflux with constant regurgitations, which were non-responsive to medical treatment. The preoperative endoscopy confirmed the diagnosis of severe biliary gastritis secondary to alkaline reflux. The distance between the gastro-jejunostomy and the Braun anastomosis was also measured with a pediatric colonoscope and the length of the efferent limb was estimated to be 80 cm. Identification of the afferent and efferent limb was complicated by the patient's incomplete intestinal malrotation with the angle of Treitz being present in the right hypochondrium. Intra-operative gastroscopy enabled visualization of the jejuno-jejunostomy and ensured correct interpretation of the anatomy. Subsequently, resection of the afferent limb completed the revision into a Roux-en-Y anatomy. The patient recovered well after the surgery and was discharged home on post-operative day 2. At 6 months follow-up, the patient's reflux symptoms have completely disappeared. BII reconstruction with or without Braun entero-enterostomy is a classic historical option following distal gastrectomy. Surgical revision of a BII into a Roux-en-Y anatomy is a good solution for severe biliary reflux and other long-term complications. Intra-operative endoscopy is a great adjunct to laparoscopic exploration in case of complex surgical procedures.

[The key points of prevention for special surgical complications after radical operation of gastric cancer].

PubMed

Xu, Hao; Wang, Weizhi; Li, Panyuan; Zhang, Diancai; Yang, Li; Xu, Zekuan

2017-02-25

Incidence of gastric cancer is high in China and standard radical operation is currently the main treatment for gastric cancer. Postoperative complications, especially some special complications, can directly affect the prognosis of patients, even result in the increase of mortality. But the incidences of these special complications are low, so these complications are often misdiagnosed and delayed in treatment owing to insufficient recognition of medical staff. These special complications include (1) Peterson hernia: It is an abdominal hernia developed in the space between Roux loop and transverse colon mesentery after Roux-Y reconstruction of digestive tract. Peterson hernia is rare and can quickly result in gangrenous ileus. Because of low incidence and without specific clinical symptoms, this hernia does not attract enough attention in clinical practice, so the outcome will be very serious. Once the diagnosis is made, an emergent operation must be performed immediately. Peterson space should be closed routinely in order to avoid the development of hernia. (2) Lymphatic leakage: It is also called chyle leakage. Cisterna chylus is formed by gradual concentration of extensive lymphatic net to diaphragm angle within abdominal cavity. Lymphadenectomy during operation may easily damage lymphatic net and result in leakage. The use of ultrasonic scalpel can decrease the risk of lymphatic leakage in certain degree. If lymphatic leakage is found during operation, transfixion should be performed in time. Treatment includes total parenteral nutrition, maintenance of internal environment, supplement of protein, and observation by clamp as an attempt. (3)Duodenal stump leakage: It is one of serious complications affecting the recovery and leading to death after subtotal gastrectomy. Correct management of duodenal stump during operation is one of key points of the prevention of duodenal stump leakage. Routine purse embedding of duodenal stump is recommend during operation. The key treatment of this complication is to promt diagnosis and effective hemostasis.(4) Blood supply disorder of Roux-Y intestinal loop: Main preventive principle of this complication is to pay attention to the blood supply of vascular arch in intestinal edge. (5) Anastomotic obstruction by big purse of jejunal stump: When Roux-en-Y anastomosis is performed after distal radical operation for gastric cancer, anvil is placed in the remnant stomach and anastomat from distal jejunal stump is placed to make gastrojejunal anastomosis, and the stump is closed with big purse embedding. The embedding jejunal stump may enter gastric cavity leading to internal hernia and anastomotic obstruction. We suggest that application of interruptable and interlocking suture and fixation of stump on the gastric wall can avoid the development of this complication.

Uncut Roux-en-Y reconstruction after totally laparoscopic distal gastrectomy with D2 lymph node dissection for early stage gastric cancer.

PubMed

Huang, Hua; Long, Ziwen; Xuan, Yi

2016-01-01

Roux Stasis Syndrome is a well-known complication after Roux-en-Y reconstruction. Uncut Roux-en-Y technique, would preserve unidirectional intestinal myoelectrical activity and diminish Roux Stasis Syndrome. A 61 years old woman with moderately differentiated adenocarcinoma of antrum who was diagnosed by gastroscopy and histological test, underwent totally laparoscopic distal gastrectomy (TLDG) with D2 lymph node dissection and uncut Roux-en-Y reconstruction (URYR). The length of operation was 190 min with bleeding of about 40 mL. The patient recovers well postoperation and discharged from hospital on the 7 th day. TLDG with intracorporeal uncut Roux-en-Y gastrojejunostomies using laparoscopic linear staplers was safe and feasible with minimal invasiveness.

Surgery for chronic pancreatitis. Drainage versus resection.

PubMed Central

Proctor, H J; Mendes, O C; Thomas, C G; Herbst, C A

1979-01-01

A retrospective study of 49 patients with chronic obstructive and chronic calcific pancreatitis is presented. All patients were operated upon and underwent either a partial pancreatectomy or internal drainage of the ductal system into a Roux-en-Y loop of jejunum. The criteria for selection of operation are discussed, and the follow-up of the two operative groups is given. In patients selected as described, internal drainage provided better relief of pain and was accomplished with a lower operative mortality and morbidity and with less postoperative pancreatic insufficiency. Images Fig. 1. Fig. 2. Fig. 3. PMID:443918

Gastrointestinal symptoms, motility, and transit after the Roux-en-Y operation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Perino, L.E.; Adcock, K.A.; Goff, J.S.

1988-04-01

Roux-en-Y patients have symptoms that vary from almost none to inability to tolerate oral feedings. This study was designed to determine whether there is a relationship between a patient's symptoms and the function of the gastric remnant or the Roux-limb. Gastric remnant and Roux-limb emptying were studied in eight patients with technetium-99m-labeled oatmeal and Roux-limb motor activity was measured with a water-perfused manometry system. We found that gastric emptying was rarely significantly slowed, but emptying of the Roux-limb was delayed in several patients. We also found that there was a rough correlation between the patient's symptoms and the degree ofmore » abnormal motility found in the Roux-limb. There is no known reason for these abnormalities in Roux-limb function in some patients after a Roux-en-Y, but our finding of worse abnormalities in those who had multiple previous gastric surgeries suggests that the symptoms and dysfunction may be related to the number of surgeries, as well as to the type of surgery.« less

Pancreaticojejunostomy, hepaticojejunostomy and double Roux-en-Y digestive tract reconstruction for benign pancreatic diseases.

PubMed

Jia, Chang-Ku; Lu, Xue-Fei; Yang, Qing-Zhuang; Weng, Jie; Chen, You-Ke; Fu, Yu

2014-09-28

Surgery such as digestive tract reconstruction is usually required for pancreatic trauma and severe pancreatitis as well as malignant pancreatic lesions. The most common digestive tract reconstruction techniques (e.g., Child's type reconstruction) for neoplastic diseases of the pancreatic head often encompass pancreaticojejunostomy, choledochojejunostomy and then gastrojejunostomy with pancreaticoduodenectomy, whereas these techniques may not be applicable in benign pancreatic diseases due to an integrated stomach and duodenum in these patients. In benign pancreatic diseases, the aforementioned reconstruction will not only increase the distance between the pancreaticojejunostomy and choledochojejunostomy, but also the risks of traction, twisting and angularity of the jejunal loop. In addition, postoperative complications such as mixed fistula are refractory and life-threatening after common reconstruction procedures. We here introduce a novel pancreaticojejunostomy, hepaticojejunostomy and double Roux-en-Y digestive tract reconstruction in two cases of benign pancreatic disease, thus decreasing not only the distance between the pancreaticojejunostomy and choledochojejunostomy, but also the possibility of postoperative complications compared to common reconstruction methods. Postoperatively, the recovery of these patients was uneventful and complications such as bile leakage, pancreatic leakage and digestive tract obstruction were not observed during the follow-up period.

In vitro motility changes in Roux limb after Roux-en-Y reconstruction.

PubMed

Dogan, N; Gokakin, A K; Koyuncu, A; Bagcivan, I; Aydin, C; Topcu, O; Yildirim, S

2014-01-01

The aim of this study is to compare the motility of Roux limb with that of normal segment. Rats were divided into 3 equal groups as control, Roux-en-Y (Group A) and Roux-en-Y with vagotomy (Group B). Only midline incision and manipulations were applied in control group. Following distal gastrectomy, Roux-en-Y reconstruction was applied in Group A, while vagotomy Roux-en-Y gastrojejunostomy was applied in Group B. Rats were sacrificed 1 month later by cervical dislocations under anesthesia. The obtained jejunal segments were cut into four equal parts. The bath was 37 °C warm while 95 % O2 and 5 % CO2 gases were supplied in 10 ml bicarbonate Krebs' solution. KCl responses were similar in all three groups. Acetylcholine contraction responses in the vagotomy and non-vagotomy Roux-en-Y groups was higher than in those in control group significantly (p < 0.05). This response in vagotomy Roux-en-Y group was also higher than that in non-vagotomy group (p < 0.05). The induced electrical field stimulation contraction response in the vagotomy + Roux-en-Y group was lower than those in control group and non-vagotomy group (p < 0.05). These results show that muscarinic receptor density and/or function may increase after vagotomy and non-vagotomy group operation, and vagotomy may contribute to this increase. The decrease in electrical signal response in vagotomy Roux-en-Y group may depend on the decrease in acetylcholine oscillation from the cholinergic nerve ending (Tab. 1, Fig. 5, Ref. 25).

Hemoptysis due to pulmonary pseudosequestration secondary to gastro-pulmonary fistula after a revisional bariatric operation.

PubMed

Santacruz, Carlos Cerdán; Rodríguez, María Conde; Sánchez-Pernaute, Andrés; García, Antonio José Torres

2014-10-01

We report the case of a patient with a history of a complicated revisional bariatric operation who developed a lung pseudosequestration secondary to a gastro-pulmonary fistula. As the patient presented with recurrent hemoptysis, she was initially submitted to embolization of the aberrant vessels and later to a definite operation, which consisted on a diversion of the gastric fistula into a Roux-en-Y intestinal loop. It is an exceptional case about late complications of bariatric surgery, and it underlines the importance of discarding these complications even when the clinical manifestations affect another anatomic region different from the operated abdomen.

Hemoptysis due to pulmonary pseudosequestration secondary to gastro-pulmonary fistula after a revisional bariatric operation

PubMed Central

Santacruz, Carlos Cerdán; Rodríguez, María Conde; Sánchez-Pernaute, Andrés; García, Antonio José Torres

2014-01-01

We report the case of a patient with a history of a complicated revisional bariatric operation who developed a lung pseudosequestration secondary to a gastro-pulmonary fistula. As the patient presented with recurrent hemoptysis, she was initially submitted to embolization of the aberrant vessels and later to a definite operation, which consisted on a diversion of the gastric fistula into a Roux-en-Y intestinal loop. It is an exceptional case about late complications of bariatric surgery, and it underlines the importance of discarding these complications even when the clinical manifestations affect another anatomic region different from the operated abdomen. PMID:25276245

A Peterson's hernia and subsequent small bowel volvulus: surgical reconstruction utilizing transverse colon as a new Roux-en-Y limb - 1 case.

PubMed

Jang, Jae Seong; Shin, Dong Gue

2013-12-01

Peterson's hernia is an internal hernia that can occur after Roux-en-Y anastomosis. It often accompanies small bowel volvulus and is prone to strangulation. Reconstruction of intestinal continuity after massive small bowel resection in a patient who undergoes near total gastrectomy and Roux-en-Y anastomosis can be difficult. A 74-year-old man who had undergone a near total gastrectomy and Roux-en-Y gastrojejunostomy for stomach cancer presented with abdominal pain. The preoperative computed tomography showed strangulated small bowel volvulus. During the emergent laparotomy, we found a strangulated Peterson's hernia with small bowel volvulus. After resection of the necrotized intestine, we made a new Roux-en-Y anastomosis connecting the remnant stomach and the jejunum with a transverse colon segment. We were safely able to connect the remnant stomach and the jejunum by making a new Roux-en-Y anastomosis utilizing a transverse colon segment as a new Roux-limb by two stage operation.

Abdominal Pain After Roux-En-Y Gastric Bypass for Morbid Obesity.

PubMed

Mala, Tom; Høgestøl, Ingvild

2018-05-01

Roux-en-Y gastric bypass is widely used as treatment of morbid obesity. Weight loss, effects on obesity-related co-morbidities and quality of life are well documented post Roux-en-Y gastric bypass. Other outcome measures are less well studied. This review explores aspects of prevalence, diagnostic evaluations, etiology, and treatment of abdominal pain specific to Roux-en-Y gastric bypass. The review is based on PubMed searches and clinical experience with Roux-en-Y gastric bypass. Symptoms in the early postoperative phase (<30 days) were not included. Based on limited evidence, up to about 30% of the patients may perceive recurrent abdominal pain post Roux-en-Y gastric bypass in the long term. A substantial subset of patients will need health-care evaluation for acute abdominal pain and hospital admission. The etiology of abdominal pain is heterogeneous and includes gallstone-related disease, intestinal obstruction, anastomotic ulcerations and strictures, intestinal dysmotility, dysfunctional eating, and food intolerance. Surgical treatment and guidance on diet and eating habits may allow symptom relief. The cause of pain remains undefined for a subset of patients. Impact of abdominal pain post Roux-en-Y gastric bypass on the perception of well-being, quality of life, and patient satisfaction with the procedure needs to be further evaluated and may be influenced by complex interactions between new symptoms post Roux-en-Y gastric bypass and relief of pre-existing symptoms. Abdominal pain should be part of follow-up consultations post Roux-en-Y gastric bypass. Future studies should focus on combined evaluations before and after surgery to enlighten potential casual relationships between abdominal pain and Roux-en-Y gastric bypass.

Manometry of the Upper Gut Following Roux-en-Y Gastric Bypass Indicates That the Gastric Pouch and Roux Limb Act as a Common Cavity.

PubMed

Björklund, Per; Lönroth, Hans; Fändriks, Lars

2015-10-01

The motility of the upper gut after Roux-en-Y gastric bypass (RYGBP) is underexplored. We aimed to investigate the oesophago-gastro-Roux limb motor activity during fasting and after food intake. Eighteen morbidly obese patients were examined at least 2 years after RYGBP. A high-resolution manometry catheter was positioned to straddle the oesophagogastric junction, the gastric pouch and the proximal Roux limb using transmucosal potential difference measurements. Three patients with vertical banded gastroplasty (VBG) were also studied. During the fasting state, the gastric pouch had low or no activity whereas the Roux limb exhibited regular migrating motility complexes (MMCs) being initiated just distal to gastroenteroanastomosis. Median cycle duration was 72 min, and the median propagating velocity of the phase III MMC phase was 2.7 cm/min (n = 8). When patients were asked to eat until they felt comfortably full, intraluminal pressure increased by 6 to 8 cmH₂O without any significant difference between gastric pouch and the Roux limb (n = 9). The increased intraluminal pressure following food intake correlated neither to weight loss nor to meal size or rate of eating. A successful RYGBP is associated with MMC in the Roux limb during fasting. The gastric pouch and the Roux limb behaved as a common cavity during food ingestion. Data do not support the hypothesis that the alimentary limb pressure in response to food intake influences either meal size or weight loss.

Laparoscopic diagnosis of retrograde peristalsis and intussusception in Roux-en-Y limb after laparoscopic gastrectomy: A case report.

PubMed

Yoshiyama, Shigeyuki; Toiyama, Yuji; Ichikawa, Takashi; Shimura, Tadanobu; Yasuda, Hiromi; Hiro, Jun-Ichiro; Ohi, Masaki; Araki, Toshimitsu; Kusunoki, Masato

2018-06-05

The cause of jejunojejunal intussusception, a rare complication after Roux-en-Y gastric surgery, remains unclear. Here, we present a case of retrograde jejunojejunal intussusception that occurred after laparoscopic distal gastrectomy with Roux-en-Y reconstruction. A 51-year-old woman who had undergone laparoscopic distal gastrectomy and Roux-en-Y reconstruction for early gastric cancer 6 years previously was admitted to our hospital with abdominal pain. Abdominal CT revealed the "target sign," and she was diagnosed as having small bowel intussusception. Laparoscopic surgery resulted in a diagnosis of retrograde intussusception of the distal jejunum of the Roux-en-Y anastomosis with retrograde peristalsis in the same area. The Roux-en-Y anastomosis site and intussuscepted segment were resected laparoscopically. To the best of our knowledge, this is the first report of laparoscopic diagnosis of retrograde peristalsis in the distal jejunum of a Roux-en-Y anastomosis. Additionally, relevant published reports concerning this unusual condition are discussed. © 2018 Japan Society for Endoscopic Surgery, Asia Endosurgery Task Force and John Wiley & Sons Australia, Ltd.

Antireflux Status Post Roux-en-Y anastomosis: An Experimental Study for Optimal Antireflux Technique.

PubMed

Verma, Ajay Kumar; Purbey, Om Prakash; Kureel, Shiv Narain; Gupta, Archika; Pandey, Anand; Sunil, Kanoujia; Chaubey, Digamber

2018-01-01

Roux-en-Y hepaticojejunostomy has been a gold standard to establish biliary-enteric anastomosis for various surgical indications, but associated with variable incidences of cholangitis. This experimental study was conducted to report a modification in Roux-en-Y anastomosis for possible better alternative to provide antireflux procedure after Roux-en-Y biliary-enteric anastomosis with the aim to minimize the possibility of reflux and its consequences. For experimental study, the required fresh segment of Lamb's small intestine was procured. Three sets of Roux-en-Y anastomosis were created for each experiment. In set 1, there was simple Roux-en-Y anastomosis. In set 2, Roux-en-Y anastomosis along with 4-5 cm long spur between the hepatic and duodenal limbs was created. In set 3, in addition to Roux-en-Y with creation of spur, additional antireflux mechanism was created at the junction of upper two-third and lower one-third of the hepatic limb. Saline mixed contrast was infused by infusion pump to raise the intraluminal pressure to more than 10 cm of H 2 O. X-ray was taken at that time. In set 1, all preparations demonstrated reflux of contrast in the hepatic limb. The set 2 also demonstrated the same findings of 100% reflux in the hepatic limb. In set 3, No reflux was observed in 8 (80%) preparations while remaining 2 (20%) preparations reveal partial reflux. This experimental study suggests that the provision of spur and additional valve may be able to decrease the possibility of reflux in Roux-en-Y biliary-enteric anastomosis.

Nutrient deficiency and obstetrical outcomes in pregnant women following Roux-en-Y gastric bypass: A retrospective Danish cohort study with a matched comparison group.

PubMed

Hammeken, Lianna Hede; Betsagoo, Ramsina; Jensen, Ann Nygaard; Sørensen, Anne Nødgaard; Overgaard, Charlotte

2017-09-01

Roux-en-Y gastric bypass surgery and small-for-gestational-age births are known to be associated although the etiology is not fully understood. This study aimed to investigate pregnancy outcomes and maternal nutritional status among pregnant women with a history of Roux-en-Y gastric bypass using maternal anemia and gestational weight gain as indicators of micronutrient and macronutrient deficiency in pregnancy. The study was designed as a retrospective matched cohort study. All Roux-en-Y-gastric-bypass-operated pregnant women (n=151) who were followed in the outpatient obstetric clinic at Aalborg University Hospital in Denmark and gave birth between 1 January 2010 and 31 December 2013 were included. Each Roux-en-Y-gastric-bypass-operated woman was closely matched with a non-Roux-en-Y-gastric-bypass-operated woman. Primary outcomes were small-for-gestational-age birth, maternal anemia and gestational weight gain. The two groups (matched 1:1) were compared by paired tests on all measures, conditional logistic regression for paired binary data and the paired t-test or Wilcoxon signed-rank test for paired continuous data. The risk of small-for-gestational-age birth (odds ratio (OR)=2.67, 95% confidence interval (CI); 1.04-6.82) and maternal anemia (OR=3.0, 95% CI; 1.09-8.25) were significantly increased for the Roux-en-Y gastric bypass group compared to the non-Roux-en-Y gastric bypass group. No significant difference was found in gestational weight gain (p=0.169) between women with a history of Roux-en-Y gastric bypass (11.51kg±8.97 standard deviation (SD)) and non- Roux-en-Y-gastric-bypass-operated women (12.18kg±6.28 SD). A history of Roux-en-Y gastric bypass surgery increases the risk of small-for-gestational-age birth and anemia, while a finding of differences in gestational weight gain is uncorroborated. Our findings suggest a role of micronutrient deficiency rather than reduced gestational weight gain in the etiology of small-for-gestational-age birth among women with a history of Roux-en-Y gastric bypass surgery. Copyright © 2017 Elsevier B.V. All rights reserved.

Three trocar laparoscopic Roux-en-y gastric bypass: a novel technique en route to the single-incision laparoscopic approach.

PubMed

Saber, Alan A; Elgamal, Mohamed H; El-Ghazaly, Tarek H; Elian, Alain R; Dewoolkar, Aditya V; Akl, Abir Hassan

2010-01-01

Laparoscopic Roux-en-Y gastric bypass is the gold standard bariatric procedure. Typically, the procedure necessitates five to seven small skin incisions for trocar placement. The senior author (AA Saber) has developed a three-trocar approach for laparoscopic Roux-en-Y gastric bypass. Sixteen patients underwent triple-incision laparoscopic Roux-en-Y gastric bypass between May 2009 and August 2009. The same surgeon performed all surgical interventions. The umbilicus was the main point of entry for all patients and the same operative technique and perioperative protocol were used in all patients. A total of sixteen triple-incision laparoscopic Roux-en-Y gastric bypasses were performed. The procedures were successfully performed in all patients. Mean operating time was 145.4 min. None of the patients required conversion to an open procedure. There were no mortalities or post-operative technical complications noted during the immediate post-operative period. Three trocar laparoscopic Roux-en-Y gastric bypass is safe, technically feasible and reproducible. This technique may be considered a "precursor" to single-incision laparoscopic Roux-en-Y gastric bypass. Copyright 2009 Surgical Associates Ltd. Published by Elsevier Ltd. All rights reserved.

Uncut Roux-en-Y reconstruction after distal gastrectomy for gastric cancer.

PubMed

Huang, Yuqin; Wang, Sen; Shi, Youquan; Tang, Dong; Wang, Wei; Chong, Yang; Zhou, Huaicheng; Xiong, Qingquan; Wang, Jie; Wang, Daorong

2016-12-01

Uncut Roux-en-Y gastrojejunostomy is a modification of the Billroth II procedure with Braun anastomosis, in which a jejunal occlusion is fashioned to avoid the Roux Stasis Syndrome. This review aimed to summarize the current knowledge about the uncut Roux-en-Y anastomosis operation, so that surgeons may be able to make informed decisions about its clinical application. Additionally, we hope that our findings will guide future research on this topic. Areas covered: The original uncut technique was associated with dehiscence or recanalization of the jejunal occlusion, and was therefore not widely applied. However, with recent improvements in the method of jejunal occlusion, the uncut Roux-en-Y reconstruction may be an appropriate alternative for digestive tract reconstruction after distal gastrectomy. This review summarizes the basic research on and clinical applications of uncut Roux-en-Y gastrojejunostomy from the following several aspects: origin of the uncut reconstruction technique, rationale for uncut reconstruction based on data from animal experiments, clinical results of the uncut reconstruction, recanalization and its countermeasures, and so on. Expert commentary: The uncut Roux-en-Y gastrojejunostomy is a controversial yet promising method of gastrointestinal reconstruction after distal gastrectomy. Prospective randomized controlled trials and long-term follow-up outcomes are required to support the modified technique in the future.

Effect of Laparoscopic Sleeve Gastrectomy vs Laparoscopic Roux-en-Y Gastric Bypass on Weight Loss in Patients With Morbid Obesity: The SM-BOSS Randomized Clinical Trial.

PubMed

Peterli, Ralph; Wölnerhanssen, Bettina Karin; Peters, Thomas; Vetter, Diana; Kröll, Dino; Borbély, Yves; Schultes, Bernd; Beglinger, Christoph; Drewe, Jürgen; Schiesser, Marc; Nett, Philipp; Bueter, Marco

2018-01-16

Sleeve gastrectomy is increasingly used in the treatment of morbid obesity, but its long-term outcome vs the standard Roux-en-Y gastric bypass procedure is unknown. To determine whether there are differences between sleeve gastrectomy and Roux-en-Y gastric bypass in terms of weight loss, changes in comorbidities, increase in quality of life, and adverse events. The Swiss Multicenter Bypass or Sleeve Study (SM-BOSS), a 2-group randomized trial, was conducted from January 2007 until November 2011 (last follow-up in March 2017). Of 3971 morbidly obese patients evaluated for bariatric surgery at 4 Swiss bariatric centers, 217 patients were enrolled and randomly assigned to sleeve gastrectomy or Roux-en-Y gastric bypass with a 5-year follow-up period. Patients were randomly assigned to undergo laparoscopic sleeve gastrectomy (n = 107) or laparoscopic Roux-en-Y gastric bypass (n = 110). The primary end point was weight loss, expressed as percentage excess body mass index (BMI) loss. Exploratory end points were changes in comorbidities and adverse events. Among the 217 patients (mean age, 45.5 years; 72% women; mean BMI, 43.9) 205 (94.5%) completed the trial. Excess BMI loss was not significantly different at 5 years: for sleeve gastrectomy, 61.1%, vs Roux-en-Y gastric bypass, 68.3% (absolute difference, -7.18%; 95% CI, -14.30% to -0.06%; P = .22 after adjustment for multiple comparisons). Gastric reflux remission was observed more frequently after Roux-en-Y gastric bypass (60.4%) than after sleeve gastrectomy (25.0%). Gastric reflux worsened (more symptoms or increase in therapy) more often after sleeve gastrectomy (31.8%) than after Roux-en-Y gastric bypass (6.3%). The number of patients with reoperations or interventions was 16/101 (15.8%) after sleeve gastrectomy and 23/104 (22.1%) after Roux-en-Y gastric bypass. Among patients with morbid obesity, there was no significant difference in excess BMI loss between laparoscopic sleeve gastrectomy and laparoscopic Roux-en-Y gastric bypass at 5 years of follow-up after surgery. clinicaltrials.gov Identifier: NCT00356213.

[[Estimation of bilio-oigestive and interintestinal anastomoses, formed in accordance to method of a high-frequency electric welding of tissues, in experiment].

PubMed

Hutsuliak, A I

2016-08-01

In the experiment on 50 rabbits cholecysto-entero and entero-entero anastomoses were formed on intestinal Roux loop. In 35 animals (the main group) a single layer evert- ing anastomoses by using high frequence (HF) electric welding method were formed, in 15 (the comparison group) single row suture anastomoses has been done. The anas- tomosis sufficiency were performed by using hydropressure, pneumopressure meth- ods and breakload test. It was established that all anastomoses formed by HF-electric welding method were passable and hermetic, also had strong sufficiency. Strength of weld joint in the postoperative period increased in a linear progression and after 3 weeks almost reached strength intact intestine (240-250 mm Hg).

Pancreatic transplantation for diabetes mellitus. Discussion of indications and surgical technique with reference to 3 cases.

PubMed

Lundgren, G; Arnep, P; Groth, C G; Hårdstedt, C; Lewander, R; Ringdén, O; Ostman, J

Three patients reveived segmental pancreatic transplants. In two the main indication was hyperlabile diabetes, and in the third progressive loss of vision. Vascular anastomoses were to the iliac vessels, the graft being placed extraperitoneally. The pancreatic duct was ligated in the first case, while the other two, the transected end of the pancreatic graft was implanted into a jejunal Roux-Y loop. Two of the patients had normal blood glucose levels without insulin administration for 40 and 35 days, respectively. The grafts then underwent rejection and were removed. In both cases the postoperative course was complicated by pancreatic fistulae. In the 3rd patient the graft failed on the day after operation, due to venous trombosis.

[Rare bile duct anatomy variant - Right bile duct intraparenchymal junction into the left bile duct].

PubMed

Gál, Adrián Róbert; Kalmár-Nagy, Károly; Fincsur, András; Horváth, Örs Péter; Vereczkei, András

2018-03-01

The authors present a case of a 67-year-old male patient, who previously had been diagnosed with a malignant liver tumor localized in segment II. He underwent bisegmentectomy (II and III) and partial IV segmentectomy. After the primary surgery jaundice developed, the level of bilirubin increased and after several imaging modalities reoperation was indicated. During the surgery a rare bile duct anatomy variant was found. The right hepatic duct joined the left duct in the parenchyma of the left lobe, and was ligated at the resection. As the liver hilum was not explored, the absence of the right duct was not discovered. Reconstruction of the biliary system was accomplished by a Roux-en-Y loop.

The Kirschner operation for cancer of the oesophagus.

PubMed Central

Mannell, A.

1982-01-01

In 1920 Kirschner described an operation to bypass oesophageal strictures. In this operation the stomach is brought to the neck by the subcutaneous route and the fundus anastomosed to the proximal end of the divided cervical oesophagus. The distal cervical oesophagus is closed and the intra-abdominal oesophagus is drained into a Roux-en-Y loop of jejunum. This paper reports the performance of this operation on 15 African patients with carcinoma of the oesophagus invading the tracheobronchial tree. There were no operative deaths and all the patients could eat a normal diet after the operation. Ten patients also received radiation therapy to the tumour. The technique of the operation and the late results of treatment are discussed. Images FIG. 1 FIG. 2 PMID:7092095

Elevated fasting and postprandial C-terminal telopeptide after Roux-en-Y gastric bypass.

PubMed

Maghsoodi, Negar; Alaghband-Zadeh, Jamshid; Cross, Gemma F; Werling, Malin; Fändriks, Lars; Docherty, Neil G; Olbers, Torsten; Dew, Tracy; Sherwood, Roy A; Vincent, Royce P; le Roux, Carel W

2017-07-01

Background Roux-en-Y gastric bypass increases circulating bile acid concentrations, known mediators of postprandial suppression of markers of bone resorption. Long-term data, however, indicate that Roux-en-Y gastric bypass confers an increased risk of bone loss on recipients. Methods Thirty-six obese individuals, median age 44 (26-64) with median body mass index at baseline of 42.5 (40.4-46) were studied before and 15 months after Roux-en-Y gastric bypass. After an overnight fast, patients received a 400 kcal mixed meal. Blood samples were collected premeal then at 30-min periods for 120 min. Pre and postmeal samples were analysed for total bile acids, parathyroid hormone and C-terminal telopeptide. Results Body weight loss post Roux-en-Y gastric bypass was associated with a median 4.9-fold increase in peak postprandial total bile acid concentration, and a median 2.4-fold increase in cumulative food evoked bile acid response. Median fasting parathyroid hormone, postprandial reduction in parathyroid hormone and total parathyroid hormone release over 120 min remained unchanged after surgery. After surgery, median fasting C-terminal telopeptide increased 2.3-fold, peak postprandial concentrations increased 3.8-fold and total release was increased 1.9-fold. Conclusions Fasting and postprandial total bile acids and C-terminal telopeptide are increased above reference range after Roux-en-Y gastric bypass. These changes occur in spite of improved vitamin D status with supplementation. These results suggest that post-Roux-en-Y gastric bypass increases in total bile acids do not effectively oppose an ongoing resorptive signal operative along the gut-bone axis. Serial measurement of C-terminal telopeptide may be of value as a risk marker for long-term skeletal pathology in patients post Roux-en-Y gastric bypass.

Spiral assisted ERCP is equivalent to single balloon assisted ERCP in patients with Roux-en-Y anatomy.

PubMed

Lennon, Anne Marie; Kapoor, Sumit; Khashab, Mouen; Corless, Erin; Amateau, Stuart; Dunbar, Kerry; Chandrasekhara, Vinay; Singh, Vikesh; Okolo, Patrick I

2012-05-01

Endoscopic retrograde cholangiopancreatography (ERCP) is often unsuccessful in patients with Roux-en-Y anatomy. Augmented enteroscopy allows deep insertion into the small bowel and can be useful in patients with Roux-en-Y anatomy. The aim of this study was to compare single balloon assisted ERCP (SBE-ERCP) and spiral assisted ERCP (SE-ERCP) in patients with Roux-en-Y anatomy in terms of diagnostic and therapeutic yield, procedure time, and complications. This is a retrospective cohort study of consecutive patients with Roux-en-Y anatomy who underwent SBE-ERCP or SE-ERCP between October 2007 and March 2011. Diagnostic yield was defined as successful duct cannulation. Therapeutic yield was defined as the ability to successfully carry out endoscopic therapy in those cannulated. Procedure time and complications were assessed. Thirty-four consecutive patients with Roux-en-Y anatomy underwent 54 ERCP procedures. The overall diagnostic yield was 44.4% with no significant difference between the diagnostic yield of SBE-ERCP (48.3%) and SE-ERCP (40%). The diagnostic yield was lower in patients with gastric by-pass (38.9%) compared with other types of Roux-en-Y anatomy (47.2%) but this was not statistically significant (P = 0.772). The overall therapeutic yield was 93.8%, with a therapeutic yield of 100% for SBE-ERCP and 87.5% for SE-ERCP (P = 1.0). There was one perforation during SBE-ERCP, giving a complication rate of 3.5%. The mean procedure time did not differ between the two techniques. Diagnostic and therapeutic yields are similar with SBE-ERCP and SE-ERCP in patients with Roux-en-Y anatomy with no significant difference in procedure time or complication rates.

Small intestinal volvulus following laparotomy for endometrial clear cell carcinoma in a woman with a past history of total gastrectomy and Roux-en-Y anastomosis for gastric carcinoma.

PubMed

Chin, Georgiana S M; Heng, Robert; Neesham, Deborah E; Petersen, Rodney W

2002-12-01

Small intestinal volvulus is a rare complication following Roux-en-Y anastomosis. A 63-year-old woman was diagnosed with small intestinal volvulus following laparotomy for clear cell carcinoma of the endometrium. Her past medical history included a total gastrectomy and antecolic Roux-en-Y anastomosis for Duke's B gastric carcinoma. Operative findings were of transmesenteric herniation of the ileum through the Roux-en-Y small intestinal mesenteric window, with metastatic deposits fixing the hernia at its base to create a volvulus. The proximal transverse colon was very dilated and thin due to partial obstruction by the volvulus. Her treatment involved adhesiolysis and unraveling of the small intestinal volvulus. This is the first case report of a small intestinal volvulus following a Roux-en-Y anastomosis involving a metastatic gynacological malignancy.

Hyperammonemic syndrome after Roux-en-Y gastric bypass.

PubMed

Fenves, Andrew Z; Shchelochkov, Oleg A; Mehta, Ankit

2015-04-01

Hyperammonemic encephalopathy is an uncommon but severe complication of the Roux-en-Y gastric bypass surgery for obesity. Mechanisms underlying this complication are incompletely understood, resulting in delayed recognition and management. This study evaluated common laboratory findings and possible etiology of hyperammonemic encephalopathy after successful Roux-en-Y gastric bypass surgery. A retrospective review of 20 patients identified through our own clinical practice was conducted, with the addition of similar cases from other institutions identified through the review of literature. Patients presenting with hyperammonemic encephalopathy after Roux-en-Y gastric bypass surgery presented with overlapping clinical and laboratory findings. Common features included: (1) weight loss following successful Roux-en-Y gastric bypass for obesity; (2) hyperammonemic encephalopathy accompanied by elevated plasma glutamine levels; (3) absence of cirrhosis; (4) hypoalbuminemia; and (5) low plasma zinc levels. The mortality rate was 50%. Ninety-five percent of patients were women. Three patients were diagnosed with proximal urea cycle disorders. One patient experienced improvement in the hyperammonemia after surgical correction of spontaneous splenorenal shunt. Hyperammonemic encephalopathy after Roux-en-Y gastric bypass surgery is a newly recognized, potentially fatal syndrome with diverse pathophysiologic mechanisms encompassing genetic and nongenetic causes. © 2015 The Obesity Society.

A modified uncut Roux-en-Y anastomosis in totally laparoscopic distal gastrectomy: preliminary results and initial experience.

PubMed

Ma, Jun-Jun; Zang, Lu; Yang, Annie; Hu, Wei-Guo; Feng, Bo; Dong, Feng; Wang, Ming-Liang; Lu, Ai-Guo; Li, Jian-Wen; Zheng, Min-Hua

2017-11-01

To investigate the safety and feasibility of totally laparoscopic uncut Roux-en-Y anastomosis in the distal gastrectomy with D2 dissection for gastric cancer. We also summarized the preliminary experience of totally laparoscopic uncut Roux-en-Y anastomosis. A retrospective analysis was done in 51 cases of total laparoscopic uncut Roux-en-Y anastomosis in the distant gastrectomy with D2 dissection for gastric cancer in our hospital from September 2014 to December 2015. All of 51 cases underwent total laparoscopic uncut Roux-en-Y anastomosis. All the procedures were performed successfully. There were neither conversions to open surgery nor intraoperative complications in all 51 cases. In this study, the median operative time was 170 (135-210) min and the median time of anastomosis was 27 (24-41) min. The blood loss was 60 (30-110) ml. The time to flatus and length of postoperative hospital stay were 2 (1-3) days, and 8 (7-12) days, respectively. The mean lymph node harvest was 34 (18-49). One anastomotic bleeding occurred postoperatively which was cured by conservative treatment. No major postoperative complication occurred, such as anastomotic leak, anastomotic stenosis, and Roux stasis syndrome. After a short-term follow-up, no recanalization or reflux gastritis was encountered by endoscopy. The totally laparoscopic uncut Roux-en-Y anastomosis in distal gastrectomy with lymph node dissection for gastric cancer is safe and feasible, with a very low rate of recanalization and reflux gastritis.

[Advantage investigation of totally laparoscopic modified Roux-en-Y reconstruction].

PubMed

Liu, Tianzhou; Ma, Zhiming; Sun, Pengda; Li, Jinlong; Fang, Xuedong; Tong, Ti; Zhu, Jiaming

2016-01-01

To investigate the clinical advantage of the application of modified Roux-en-Y reconstruction after totally laparoscopic total gastrectomy. Clinical data of 36 patients who underwent totally laparoscopic total gastrectomy with Roux-en-Y reconstruction by one medical team for gastric adenocarcinoma between January 2014 and December 2014 in the Second Hospital of Jilin University were retrospectively analyzed. Patients were divided into classic Roux-en-Y group (CRY, 16 cases) and modified Roux-en-Y group (MRY, 20 cases) according to reconstructive methods. The data concerning the intraoperative and postoperative situation in two groups were compared. Operation was successfully completed in all the cases without conversion to laparotomy. Compared to CRY group, MRY group had shorter mean operative time [(260.9 ± 21.2) min vs. (287.9 ± 19.0) min, P=0.000], shorter mean reconstruction duration [(32.4 ± 9.2] min vs. (45.4 ± 13.2) min, P=0.001] and less intraoperative bleeding [(50.9 ± 23.5) ml vs. (67.0 ± 20.5) ml, P=0.000]. Jejunum mesentery dissection and jejunum resection were not necessary in MRY group. However, there were no significant differences in lymph nodes harvested, time to flatus, hospital stay and postoperative complications between two groups. As compared to classic Roux-en-Y reconstruction, the modified Roux-en-Y reconstruction can simplify the surgical procedures and achieve similar efficacy. It is feasible and safe, and worth further promotion in clinical practice.

Antegrade bowel intussusception after remote Whipple and Puestow procedures for treatment of pancreas divisum.

PubMed

Gigena, Manuel; Villar, Hugo V; Knowles, Negar G; Cunningham, John T; Outwater, Erik K; Leon, Luis R

2007-11-28

To date, antegrade intussusception involving a Roux-en-Y reconstruction has been reported only once. We report a case of acute bowel obstruction due to an intussusception involving two Roux-en-Y limbs in a 40-year-old woman with a history of chronic pancreatitis due to pancreas divisum. Four years preceding this event, the patient had undergone a Whipple procedure, and three years prior to that, a Puestow operation. The patient was successfully treated with bowel resection and a side-to-side anastomosis between the most distal aspect of the bowel and the most distal Roux-en-Y reconstruction, which preserved both Roux-en-Y reconstructions.

Antegrade bowel intussusception after remote Whipple and Puestow procedures for treatment of pancreas divisum

PubMed Central

Gigena, Manuel; Villar, Hugo V; Knowles, Negar G; Cunningham, John T; Outwater, Erik K; Leon Jr, Luis R

2007-01-01

To date, antegrade intussusception involving a Roux-en-Y reconstruction has been reported only once. We report a case of acute bowel obstruction due to an intussusception involving two Roux-en-Y limbs in a 40-year-old woman with a history of chronic pancreatitis due to pancreas divisum. Four years preceding this event, the patient had undergone a Whipple procedure, and three years prior to that, a Puestow operation. The patient was successfully treated with bowel resection and a side-to-side anastomosis between the most distal aspect of the bowel and the most distal Roux-en-Y reconstruction, which preserved both Roux-en-Y reconstructions. PMID:17990363

Single Balloon Enteroscopy-Assisted Endoscopic Retrograde Cholangiopancreatography in Patients Who Underwent a Gastrectomy with Roux-en-Y Anastomosis: Six Cases from a Single Center.

PubMed

Soh, Jae Seung; Yang, Dong-Hoon; Lee, Sang Soo; Lee, Seohyun; Bae, Jungho; Byeon, Jeong-Sik; Myung, Seung-Jae; Yang, Suk-Kyun

2015-09-01

Patients with altered anatomy such as a Roux-en-Y anastomosis often present with various pancreaticobiliary problems requiring therapeutic intervention. However, a conventional endoscopic approach to the papilla is very difficult owing to the long afferent limb and acute angle of a Roux-en-Y anastomosis. Balloon-assisted enteroscopy can be used for endoscopic retrograde cholangiopancreatography (ERCP) in patients with altered anatomy. We experienced six cases of Roux-en-Y anastomosis with biliary problems, and attempted ERCP using single balloon enteroscopy (SBE). SBE insertion followed by replacement with a conventional endoscope was attempted in five of six patients. The papilla was successfully approached using SBE in all cases. However, therapeutic intervention was completed in only three cases because of poor maneuverability caused by postoperative adhesion. We conclude that in patients with Roux-en-Y anastomosis, the ampulla can be readily accessed with SBE, but longer dedicated accessories are necessary to improve this therapeutic intervention.

Optimal Roux-en-Y reconstruction after distal gastrectomy for early gastric cancer as assessed using the newly developed PGSAS-45 scale.

PubMed

Kawahira, Hiroshi; Kodera, Yasuhiro; Hiki, Naoki; Takahashi, Masazumi; Itoh, Seiji; Mitsumori, Norio; Kawashima, Yoshiyuki; Namikawa, Tsutomu; Inada, Takao; Nakada, Koji

2015-10-01

The optimal surgical procedure for distal gastrectomy with Roux-en-Y reconstruction (DGRY) remains to be determined. Recently, a self-report assessment instrument, the Postgastrectomy Syndrome Assessment Scale-45 (PGSAS-45), was compiled to evaluate symptoms, the living status and the quality of life of patients who have undergone gastrectomy. We used this scale to evaluate procedures used for DGRY. The subjects included 475 patients who underwent DGRY for stage IA/IB gastric cancer. We evaluated whether the size of the remnant stomach, length of the Roux limb, reconstruction route and anastomotic procedure affected the patients' symptoms, living status and quality of life assessed using the PGSAS-45. Patients with a residual stomach of more than half had significantly worse esophageal reflux scores than the patients with a smaller residual stomach (P = 0.0462); a residual stomach of one-third or one-fourth was favorable. A shorter length of the Roux limb was shown to be preferable to a longer Roux limb based on the results of the PGSAS-45. In addition, antecolic reconstruction and the anastomotic procedure using a linear stapler were found to be more favorable. The size of the remnant stomach and the length and route of the Roux limb significantly influence the patient-reported DGRY outcomes.

Nutrient re-routing and altered gut-islet cell crosstalk may explain early relief of severe postprandial hypoglycaemia after reversal of Roux-en-Y gastric bypass.

PubMed

Svane, M S; Toft-Nielsen, M B; Kristiansen, V B; Hartmann, B; Holst, J J; Madsbad, S; Bojsen-Møller, K N

2017-12-01

Roux-en-Y gastric bypass is associated with an increased risk of postprandial hyperinsulinaemic hypoglycaemia, but the underlying pathophysiology remains poorly understood. We therefore examined the effect of re-routing of nutrient delivery on gut-islet cell crosstalk in a person with severe postprandial hypoglycaemia after Roux-en-Y gastric bypass. A person with severe postprandial hypoglycaemia, who underwent surgical reversal of Roux-en-Y gastric bypass, was studied before reversal and at 2 weeks and 3 months after reversal surgery using liquid mixed meal tests and hyperinsulinaemic-euglycaemic clamps. The nadir of postprandial plasma glucose rose from 2.8 mmol/l to 4.1 mmol/l at 2 weeks and to 4.4 mmol/l at 3 months after reversal. Concomitant insulin- and glucagon-like peptide-1 secretion (peak concentrations and area under the curve) clearly decreased after reversal, while concentrations of glucose-dependent insulinotropic polypeptide and ghrelin increased. Insulin clearance declined after reversal, whereas clamp-estimated peripheral insulin sensitivity was unchanged. The person remained without symptoms of hypoglycaemia, but had experienced significant weight gain at 15-month follow-up. Accelerated nutrient absorption may be a driving force behind postprandial hyperinsulinaemic hypoglycaemia after Roux-en-Y gastric bypass. Re-routing of nutrients by reversal of the Roux-en-Y gastric bypass diminished postprandial plasma glucose excursions, alleviated postprandial insulin and glucagon-like peptide-1 hypersecretion and eliminated postprandial hypoglycaemia, which emphasizes the importance of altered gut-islet cell crosstalk for glucose metabolism after Roux-en-Y gastric bypass. © 2017 Diabetes UK.

Unusual Development of Iatrogenic Complex, Mixed Biliary and Duodenal Fistulas Complicating Roux-en-Y Antrectomy for Stenotic Peptic Disease of the Supraampullary Duodenum Requiring Whipple Procedure: An Uncommon Clinical Dilemma.

PubMed

Polistina, Francesco A; Costantin, Giorgio; Settin, Alessandro; Lumachi, Franco; Ambrosino, Giovanni

2010-10-23

Complex fistulas of the duodenum and biliary tree are severe complications of gastric surgery. The association of duodenal and major biliary fistulas occurs rarely and is a major challenge for treatment. They may occur during virtually any kind of operation, but they are more frequent in cases complicated by the presence of difficult duodenal ulcers or cancer, with a mortality rate of up to 35%. Options for treatment are many and range from simple drainage to extended resections and difficult reconstructions. Conservative treatment is the choice for well-drained fistulas, but some cases require reoperation. Very little is known about reoperation techniques and technical selection of the right patients. We present the case of a complex iatrogenic duodenal and biliary fistula. A 42-year-old Caucasian man with a diagnosis of postoperative peritonitis had been operated on 3 days earlier; an antrectomy with a Roux-en-Y reconstruction for stenotic peptic disease was performed. Conservative treatment was attempted with mixed results. Two more operations were required to achieve a definitive resolution of the fistula and related local complications. The decision was made to perform a pancreatoduodenectomy with subsequent reconstruction on a double jejunal loop. The patient did well and was discharged on postoperative day 17. In our experience pancreaticoduodenectomy may be an effective treatment of refractory and complex iatrogenic fistulas involving both the duodenum and the biliary tree.

Delayed gastric emptying following pancreatoduodenectomy with alimentary reconstruction according to Roux-en-Y or Billroth-II.

PubMed

Glowka, Tim R; Webler, Markus; Matthaei, Hanno; Schäfer, Nico; Schmitz, Volker; Kalff, Jörg C; Standop, Jens; Manekeller, Steffen

2017-03-20

Delayed gastric emptying (DGE) remains the most frequent complication following pancreatoduodenectomy (PD) with published incidences as high as 61%. The present study investigates the impact of bowel reconstruction techniques on DGE following classic PD (Whipple-Kausch procedure) with pancreatogastrostomy (PG). We included 168 consecutive patients who underwent PD with PG with either Billroth II type (BII, n = 78) or Roux-en-Y type reconstruction (ReY, n = 90) between 2004 and 2015. Excluded were patients with conventional single loop reconstruction after pylorus preserving procedures. DGE was classified according to the 2007 International Study Group of Pancreatic Surgery definition. Patients were analyzed regarding severity of DGE, morbidity and mortality, length of hospital stay and demographic factors. No difference was observed between BII and ReY regarding frequency of DGE. Overall rate for clinically relevant DGE was 30% (ReY) and 26% (BII). BII and ReY did not differ in terms of demographics, morbidity or mortality. DGE significantly prolongs ICU (four vs. two days) and hospital stay (20.5 vs. 14.5 days). Risk factors for DGE development are advanced age, retrocolic reconstruction, postoperative hemorrhage and major complications. The occurrence of DGE can not be influenced by the type of alimentary reconstruction (ReY vs. BII) following classic PD with PG. Old age and major complications could be identified as important risk factors in multivariate analysis. German Clinical Trials Register (DRKS) DRKS00011860 . Registered 14 March 2017.

J-pouch versus Roux-en-Y reconstruction after gastrectomy: functional assessment and quality of life (randomized trial).

PubMed

Zonča, Pavel; Malý, Tomáš; Ihnát, Peter; Peteja, Matus; Kraft, Otakar; Kuca, Kamil

2017-01-01

The aim of this study was to evaluate the quality of life and functional emptying of J-pouch versus Roux-en-Y reconstruction after total gastrectomy for malignancy. This study was designed as a prospective, nonblinded, randomized, parallel clinical trial (Trial Number: MN Ostrava, 200604). With informed consent, patients undergoing gastrectomy for malignancy were randomized to J-pouch or Roux-en-Y reconstruction. The time taken for a test semisolid meal labeled with 99m Tc-sulfur colloid to exit the reconstructed parts was measured by dynamic scintigraphy 1 year after resection. Quality of life was measured using the Eypasch questionnaire at the same time as functional emptying assessment. This trial was investigator-initiated. In all, 72 patients were included into the study. The time taken for the test meal to exit the postgastrectomy reconstruction was 16.5±10.0 minutes (mean ± standard deviation) in the Roux-en-Y group and 89.4±37.8 minutes in the "J-pouch" group; the difference was statistically significant ( P <0.001). Emptying of the J-pouch appeared to be a linear decreasing function compared to the exponential pattern seen in the Roux-en-Y group. The quality of life measurement showed scores of 106±18.8 points (mean ± standard deviation) in the Roux-en-Y group compared to 122±22.5 points in the J-pouch group; the difference was statistically significant ( P =0.0016). There were no important adverse events. After total gastrectomy, a J-pouch reconstruction empties more slowly and is associated with higher quality of life compared to Roux-en-Y reconstruction. Whether these two observations have a direct causative link remains unanswered.

A dual-loop adaptive control for minimizing time response delay in real-time structural vibration control with magnetorheological (MR) devices

NASA Astrophysics Data System (ADS)

Chen, Xi; Li, Yancheng; Li, Jianchun; Gu, Xiaoyu

2018-01-01

Time delay is a challenge issue faced by the real-time control application of the magnetorheological (MR) devices. Not to deal with it properly may jeopardize the effectiveness of the control, even lead to instability of the control system or catastrophic failure. This paper proposes a dual-loop adaptive control to address the response time delay associated with MR devices. In the proposed dual-loop control, the inner loop is designed to compensate the time delay of MR device induced by the PWM current driver. While the outer loop control can be any structural control algorithm with aims to reducing structural responses of a building during extreme loadings. Here an adaptive control strategy is adopted. To verify the proposed dual-loop control, a smart base isolation system employing magnetorheological elastomer base isolators is used as an example to illustrate the control effect. Numerical study is then conducted using a 5 -storey shear building model equipped with smart base isolation system. The result shows that with the implementation of the inner loop, the control current can instantly follow the control command which reduce the possibility of instability caused by the time delay. Comparative studies are conducted between three control strategies, i.e. dual-loop control, Lyapunov’s direct method based control and optimal passive base isolation control. The results of the study have demonstrated that the proposed dual-loop control strategy can achieve much better performance than the other two control strategies.

Duodenum inclusion in alimentary transit for preventing or correcting nutritional deficiencies resulting from Roux-en-y gastric bypass in obesity treatment.

PubMed

Ceneviva, Reginaldo

2016-01-01

Nutritional and metabolic complications can develop after Roux-en-Y gastric bypass (RYGB) when there is an exaggerated response to the anatomical and functional changes or when there is inadequate nutritional supplementation. Severe malnutrition is rare, but deficiencies of vitamin B12, iron, calcium and thiamin, metabolic bone disease and gallstones are common after RYGB. Shortage of vitamin B12, iron, calcium and also cholelithiasis are caused at least partially by excluding the duodenum and proximal jejunum from food transit. We designed a new procedure, with the maintenance of the duodenum and proximal jejunum in the gastrointestinal transit through interposition of jejunal loop, as a primary operation to prevent such deficiencies or as corrective surgery for severe malnutrition after RYGB with failure in responding to conservative treatment. Complicações nutricionais e metabólicas podem se desenvolver após a derivação gástrica em Y de Roux (DGYR) quando há uma resposta exagerada às mudanças anatômicas e funcionais ou quando há suplementação nutricional inadequada. A desnutrição grave é rara, mas deficiências de vitamina B12, ferro, cálcio e tiamina, doença óssea metabólica e cálculos biliares são comuns após a DGYR. Dessas deficiências mencionadas, a de vitamina B12, de ferro, de cálcio e também a colelitíase, são causadas, ao menos parcialmente, pela exclusão do duodeno e jejuno proximal. Um novo procedimento com a manutenção do duodeno e do jejuno proximal no trânsito gastrointestinal, mediante interposição de alça jejunal, foi idealizado como operação primária para prevenir essas deficiências ou como cirurgia corretiva de desnutrição grave após DGYR com falha na resposta a exaustivas tentativas de tratamento conservador.

Volatile (H2O, CO2) and Halogen (Cl) Systematics of SMAR MORB (44-52.5 ° S)

NASA Astrophysics Data System (ADS)

le Roux, P. J.; le Roex, A. P.; Hauri, E. H.

2013-12-01

New SIMS volatile (H2O, CO2) and halogen (Cl) concentration data are presented for fresh MORB glasses (>6wt% MgO) from the slow-spreading southern Mid-Atlantic Ridge (SMAR; 44-52.5 ° S). This data set complements previous data from the faster-spreading northern East Pacific Rise (EPR; 8-10 ° N and 12-14 ° N; le Roux et al., 2006). The selected MORB samples span the previously observed compositional range between enriched and depleted mantle source regions along this section of the SMAR (le Roux et al., 2002b), as well as the range of magma crystallization characteristics (le Roux et al., 2002a). The pre-eruption transit of MORB magmas through the upper oceanic crust can potentially result in compositional contamination through assimilation of e.g. sea-water altered crustal material and/or saline brines. This would most-noticeable through significant addition of sea-water derived Cl to a magma, resulting in excess Cl concentrations and elevated Cl/Nb ratios (>50) in erupted MORB lavas (le Roux et al., 2006; Michael & Cornell, 1998). Dissolved H2O (0.12-0.61wt%) and CO2 (69-230ppm) concentrations in the MORB glass samples provide pressure estimates of eruption initiation, and therefore the final crustal depth at which significant magma compositional modification occurred (Dsat; le Roux et al., 2006). Unlike the northern EPR region, no geophysical data are available for this section of the SMAR. A comparison of Dsat with the depth of imaged magma chambers, similar to results from the northern EPR (le Roux et al., 2006), is therefore not directly possible. However, estimates of the calculated pressures of MORB magma crystallization for these SMAR samples (le Roux et al., 2002a) can be compared with Dsat. The dissolved H2O and CO2 contents of the SMAR basalts are consistent with slow magma ascent allowing degassing to keep pace with decompression (Dsat 0-550m.b.s.l.). Observed Cl contents (15-170ppm) of these SMAR basalts are well-correlated with Nb and indicate the near absence of interaction of the magmas with hydrothermally-altered rocks in the crust (Cl/Nb 5.67-14.2). This may be due to the absence of long-lived hydrothermal systems linked to established sub-ridge magma chambers, as observed at the northern EPR where spreading rates and magma supply are both higher. le Roux et al. (2002a) CMP, 142, 582-602 le Roux et al. (2002b) EPSL, 203, 479-498 le Roux et al. (2006) EPSL, 251, 209-231 Michael; Cornell (1998) JGRes, 103, 18325-18356

To Roux or not to Roux: a comparison between Roux-en-Y and Billroth II reconstruction following partial gastrectomy for gastric cancer.

PubMed

Tran, Thuy B; Worhunsky, David J; Squires, Malcolm H; Jin, Linda X; Spolverato, Gaya; Votanopoulos, Konstantinos I; Cho, Clifford S; Weber, Sharon M; Schmidt, Carl; Levine, Edward A; Bloomston, Mark; Fields, Ryan C; Pawlik, Timothy M; Maithel, Shishir K; Norton, Jeffrey A; Poultsides, George A

2016-07-01

Although the extent of resection frequently dictates the method of reconstruction following distal subtotal gastrectomy, it is unclear whether Roux-en-Y gastrojejunostomy compared with Billroth II gastrojejunostomy is associated with superior perioperative outcomes. Patients who underwent resection for gastric cancer with Roux-en-Y or Billroth II reconstruction between 2000 and 2012 in seven academic institutions (US Gastric Cancer Collaborative) were identified. Patients who underwent total gastrectomy, gastric wedge, or palliative resections (metastatic disease or R2 resections) were excluded. Of a total of 965 patients, 447 met the inclusion criteria. A comparison between the Roux-en-Y (n = 257) and Billroth II (n = 190) groups demonstrated no differences in patient and tumor characteristics, except for Billroth II patients having a higher proportion of antral tumors (71 % vs. 50 %, p < 0.001). Roux-en-Y operations were slightly longer (244 min vs. 212 min, p < 0.001) and associated with somewhat higher blood loss (243 ml vs. 205 ml, p = 0.033). However, there were no significant differences in the length of hospital stay (8 days vs. 7 days), readmission rate (17 % vs. 18 %), 90-day mortality (5.1 % vs. 4.7 %), incidence (39 % vs. 41 %) and severity of complications, dependency on jejunostomy tube feeding at discharge (13 % vs. 12 %), same-patient decrease in serum albumin level from the preoperative to the postoperative value at 30, 60, and 90 days, receipt of adjuvant therapy (50 % vs. 53 %), or 5-year survival (44 % vs. 41 %). Although long-term quality-of-life parameters were not compared, this study did not show an advantage of Roux-en-Y gastrojejunostomy over Billroth II gastrojejunostomy in short-term perioperative outcomes. Both techniques should be regarded as equally acceptable reconstructive options following partial gastrectomy for gastric cancer.

The effect of laparoscopic Roux-en-Y gastric bypass on fibromyalgia.

PubMed

Saber, Alan A; Boros, Michael J; Mancl, Tara; Elgamal, Mohamed H; Song, Susrap; Wisadrattanapong, Therawat

2008-06-01

Fibromyalgia is a chronic debilitating disorder affecting 3-5% of the US population. Treatment of this disorder is a challenge. The incidental finding of improvement of fibromyalgia following laparoscopic Roux-en-Y gastric bypass stimulated us to study this phenomenon. A retrospective chart review of patients with fibromyalgia who underwent laparoscopic Roux-en-Y gastric bypass. Postoperative decrease in median of BMI from 49.4 to 29.7 was significant (p value = 0.0010). This was associated with statistically significant improvement in median of pain score (p value = 0.0010) and median points of tenderness (p value = 0.0010). Significant weight loss following laparoscopic Roux-en-Y gastric bypass is associated with resolution or improvement of fibromyalgia. Consequently, the bariatric surgeon should be a member of the multidisciplinary team approach for treating fibromyalgia.

The effects of bariatric surgical procedures on the improvement of metabolic syndrome in morbidly obese patients: Comparison of laparoscopic sleeve gastrectomy versus laparoscopic Roux-en-Y gastric bypass.

PubMed

Kafalı, Mehmet Ertuğrul; Şahin, Mustafa; Ece, İlhan; Acar, Fahrettin; Yılmaz, Hüseyin; Alptekin, Hüsnü; Ateş, Leyla

2017-01-01

The objective of this study was to evaluate patients who underwent laparoscopic Roux-en-Y gastric bypass and laparoscopic sleeve gastrectomy in terms of weight loss, metabolic parameters, and postoperative complications. Data on patients who underwent laparoscopic Roux-en-Y gastric bypass and laparoscopic sleeve gastrectomy with a diagnosis of morbid obesity between January 2012 and June 2014 were retrospectively evaluated. Patients were compared in terms of age, sex, body mass index, duration of operation, American Society of Anesthesiologists score, perioperative complications, length of hospital stay, and long term follow-up results. During the study period, 91 patients (45 laparoscopic Roux-en-Y gastric bypass and 46 laparoscopic sleeve gastrectomy) underwent bariatric surgery. There was no difference between the two groups in terms of preoperative patient characteristics. Both groups showed statistically significant weight loss and improvement in co-morbidities when compared with the preoperative period. Weight loss and improvement in metabolic parameters were similar in both groups. The duration of operation and hospital stay was longer in the laparoscopic Roux-en-Y gastric bypass group. Furthermore, the rate of total complications was significantly lower in the laparoscopic sleeve gastrectomy group. Laparoscopic sleeve gastrectomy is a safe and effective method with a significantly lower complication rate and length of hospital stay than laparoscopic Roux-en-Y gastric bypass, with similar improvement rates in metabolic syndrome.

Isolated and coupled superquadric loop antennas for mobile communications applications

NASA Technical Reports Server (NTRS)

Jensen, Michael A.; Rahmat-Samii, Yahya

1993-01-01

This work provides an investigation of the performance of loop antennas for use in mobile communications applications. The analysis tools developed allow for high flexibility by representing the loop antenna as a superquadric curve, which includes the case of circular, elliptical, and rectangular loops. The antenna may be in an isolated environment, located above an infinite ground plane, or placed near a finite conducting plate or box. In cases where coupled loops are used, the two loops may have arbitrary relative positions and orientations. Several design examples are included to illustrate the versatility of the analysis capabilities. The performance of coupled loops arranged in a diversity scheme is also evaluated, and it is found that high diversity gain can be achieved even when the antennas are closely spaced.

Congenital choledochal cyst: video-guided laparoscopic treatment.

PubMed

Farello, G A; Cerofolini, A; Rebonato, M; Bergamaschi, G; Ferrari, C; Chiappetta, A

1995-10-01

We report our first experience with a laparoscopic treatment of congenital choledochal cysts involving the total cyst resection and the reconstruction of the biliary and gastrointestinal tracts through a transmesocolic hepatic-jejunal Roux-en-Y loop anastomosis. The procedure was carried out in a 14-kg 6-year-old girl with a congenital choledochal cyst of the first type, according to the Alonso-Lej classification. The cyst was divided using a Multifire EndoGIA 30 stapler. Hepatic-jejunal and jejunojejunal anastomoses were made with 4.0 chrome catgut interrupted sutures. Intestinal recanalization occurred on the 2nd postoperative day and the postoperative course was uneventful. The laparoscopic approach affords several advantages: excellent intraoperative visualization of tiny structures and, therefore, great surgical accuracy; early resumption of peristalsis; no postoperative pain; no laparocele; prevention of adhesions; excellent esthetics; and quicker resumption of school and sports activities.

[Successful repair of complete pancreatic rupture and subtotal duodenal avulsion after blunt abdominal trauma in childhood--a case report].

PubMed

Knoop, M; Vorwerk, T

2003-03-01

We report the case of a 12-year-old boy who presented after a bicycle accident with handlebar injury of the epigastrium with clinical signs of hollow visceral injury and elevated pancreatic enzymes. Upon emergency laparotomy, a complete rupture of the pancreatic isthmus and a nearly total transsection of the postpyloric duodenum were encountered (Grade IV according to Lucas). Reconstruction consisted of reanastomosis of the proximal duodenum, closure of the distal end of the pancreatic head and internal drainage of the left pancreas into a Roux-en-Y jejunal loop. The postoperative course was uneventful. For rare traumatic pancreaticoduodenal lesions only individual surgical concepts are promising depending on the extent of damage. However, effort should be made to preserve as much pancreatic tissue as possible.

Comparison of double-balloon and single-balloon enteroscope for therapeutic endoscopic retrograde cholangiography after Roux-en-Y small bowel surgery.

PubMed

De Koning, Michael; Moreels, Tom G

2016-08-22

Roux-en-Y reconstructive surgery excludes the biliopancreatic system from conventional endoscopic access. Balloon-assisted enteroscopy allows therapeutic endoscopic retrograde cholangiopancreatography (ERCP) in these patients, avoiding rescue surgery. The objective of the current study is to compare success and complication rate of double-balloon (DBE) and single-balloon enteroscope (SBE) to perform ERCP in Roux-en-Y patients. Seventy three Roux-en-Y patients with suspected biliary tract pathology underwent balloon-assisted enteroscopy in a tertiary-care center. Retrospective analysis of 95 consecutive therapeutic ERCP procedures was performed to define and compare success and complication rate of DBE and SBE. Male-female ratio was 28/45 with a mean age of 58 ± 2 years. 30 (32 %) procedures were performed with DBE and 65 (68 %) with SBE. Overall ERCP success rate was 73 % for DBE and 75 % for SBE (P = 0.831). Failure was due to inability to reach or cannulate the intact papilla or bilioenteric anastomosis. Success rate was significantly higher when performed at the bilioenteric anastomosis (80 % success in 56 procedures) or at the intact papilla in short-limb Roux-en-Y (80 % in 15 procedures) as compared to the intact papilla in long-limb (58 % in 24 procedures; P = 0.040). Adverse event rates were 10 % (DBE) and 8 % (SBE) (P = 0.707) and mostly dealt with conservatively. ERCP after Roux-en-Y altered small bowel anatomy is feasible and safe using both DBE and SBE. Both techniques are equally competent with high success rates and acceptable adverse events rates. ERCP at the level of the intact papilla in long limb Roux-en-Y is less successful as compared to short-limb or bilioenteric anastomosis.

Alimentary Limb Ischemia During Roux-en-Y Gastric Bypass and its Management.

PubMed

Mittal, Tarun; Dey, Ashish; Nali, Abhilash; Taha Mustafa, Sheikh Mohammad; Malik, Vinod K

2018-05-01

Ischemia of the tip of the alimentary limb involving the gastrojejunostomy (GJ) is an unusual complication during Roux-en-Y gastric bypass (RYGB). Revision of the GJ may be needed to manage this complication. We present a case of inadvertent perforation of the jejunum by a gastric calibration tube, which was recognized on the table and appropriate measures are then taken. Repair of this enterotomy however then led to ischemia of the tip of alimentary limb extending to a portion of the GJ anastomosis. We present its subsequent management. Our patient is a morbidly obese female patient with a BMI value of 44.6 kg/msq undergoing RYGB. We performed an antecolic, antegastric linear-stapled gastrojejunostomy of 2.5 cm. After hand-sewn closure of the common enterotomy, we tried passing a 38-F Bougie through the anastomosis into the Roux limb. During this maneuver, the Bougie inadvertently perforated the Roux limb at the mesenteric border. Following the repair of this jejunal rent, the distal part of the Roux limb became dusky and involved a portion of the gastrojejunal anastomosis. The gastrojejunostomy was therefore completely revised. Intraoperatively, methylene blue dye test was done which showed no leak. Post-operative gastrografin study revealed no leak and liquids were started on POD1. Inadvertent injury by a Bougie is a rare but known complication in laparoscopic RYGB. Intraoperative recognition of the complication is essential to prompt the necessary repair. Revision of the gastrojejunostomy is necessary if the Roux limb or the anastomosis itself is ischemic and can be accomplished with good results.

[Clinical research progress of mesenteric internal hernia after Roux-en-Y reconstruction].

PubMed

Xu, Zhengrong; Guo, Wenjun

2017-03-25

Postoperative internal hernia is a rare clinical complication which often occurs after digestive tract reconstruction. Roux-en-Y anastomosis is a common type of digestive tract reconstruction. Internal hernia after Roux-en-Y reconstruction, which occurs mainly in the mesenteric defect caused by incomplete closure of mesenteric gaps in the process of digestive tract reconstruction, is systematically called, in our research, as mesenteric internal hernia after Roux-en-Y reconstruction. Such internal hernia can be divided, according to the different structures of mesentric defect, into 3 types: the type of mesenteric defect at the jejunojejunostomy (J type), the type of Petersen's defect (P type), and the type of mesenteric defect in the transverse mesocolon (M type). Because of huge differences in the number of cases and follow-up time among existing research reports, the morbidity of internal hernia after LRYGB fluctuates wildly between 0.2% and 9.0%. Delayed diagnosis and treatment of mesenteric internal hernia after Roux- en-Y reconstruction may result in disastrous consequences such as intestinal necrosis. Clinical manifestations of internal hernia vary from person to person: some, in mild cases, may have no symptoms at all while others in severe cases may experience acute intestinal obstruction. Despite the difference, one common manifestation of internal hernia is abdominal pain. Surgical treatment should be recommended for those diagnosed as internal hernia. A safer and more feasible way to conduct the manual reduction of the incarcerated hernia is to start from the distal normal empty bowel and trace back to the hernia ring mouth, enabling a faster identification of hernia ring and its track. The prevention of mesenteric internal hernia after Roux-en-Y reconstruction is related to the initial surgical approach and the technique of mesenteric closure. Significant controversy remains on whether or not the mesenteric defect should be closed in laparoscopic Roux-en-Y anastomosis. This article is to review the reports and researches on internal hernia resulting from the mesenteric defect after Roux-en-Y digestive tract reconstruction in recent years, so as to promote understanding and attention on this disease. And more active preventive measures are strongly suggested to be taken in operations where digestive tract reconstruction is involved.

Mathematics Ab Ovo: Hans Driesch and Entwicklungsmechanik.

PubMed

Priven, Silvia Waisse; Alfonso-Goldfarb, Ana M

2009-01-01

One of the factors leading to the creation of embryology as a modern discipline at the end of the 19th century was Wilhelm Roux's formulation of the program of Entwicklungsmechanik (developmental mechanics). A look into the work of Hans Driesch, an equal contributor to developmental mechanics, may shed further light on this process. For Roux, developmental mechanics was an anatomical science, but for Driesch it was associated with a mathematical and physical approach to the natural world. Likewise, Roux used the concept of mechanics as an analogy, but Driesch used it literally. Driesch's generation had been trained in a pedagogic context that emphasized mathematics and physics, which may explain why he went a step further than Roux to state that a true "mechanics" of development required the reduction of morphogenetic problems to the known laws of physics. It is argued here that this difference in background is behind the enthusiastic adoption and further development of Roux's program by Driesch's generation, a generation that conceived Entwicklungsmechanik to be the reduction of embryological processes to "the laws of matter in motion." This same mathematical and physical mindset would underscore Driesch's later construction of entelechy as a regulating factor in embryogenesis, through mathematical analysis grounded on the notion of mathematical functions.

Effect of Billroth II or Roux-en-Y Reconstruction for the Gastrojejunostomy After Pancreaticoduodenectomy: Meta-analysis of Randomized Controlled Trials.

PubMed

Yang, Ji; Wang, Chao; Huang, Qiang

2015-05-01

This study aimed to compare Billroth II with Roux-en-Y reconstruction after pancreaticoduodenectomy (PD). A literature search was carried out to identify all randomized controlled trials (RCTs) comparing postoperative complications of Billroth II versus Roux-en-Y reconstruction following PD published from 1 January 1990 to 31 August 2014. Pooled risk ratios (RRs) with 95 % confidence intervals (CIs) were calculated using fixed effects or random effects models In total, three RCTs with 470 patients were included. Using International Study Group of Pancreatic Surgery (ISGPS) definitions, incidences of delayed gastric emptying (DGE) [grades B and C (3.9 versus 12.9 %; RR 0.30, 95 % CI 0.11-0.79; P = 0.01), DGE grade C (0.7 versus 9.6 %; RR 0.11, 95 % CI 0.02-0.61; P = 0.01)] were significantly lower in the Billroth II group than in the Roux-en-Y group, as was the length of hospital stay (weighted mean difference -4.72, 95 % CI -8.91, -0.53; P = 0.03). Meta-analysis revealed that the incidence of DGE (grades B and C) after PD can be decreased by using Billroth II rather than Roux-en-Y reconstruction.

[Comparative effects of Roux-en-Y gastric bypass procedures preserving different gastric volume on blood glucose in Goto-Kakizaki rats].

PubMed

Zou, Zhong-dong; Jiao, Ya-bin; Wang, Yi-bo; Wang, Chang; Liu, Bin; Wang, Yu; Huang, Sheng

2012-01-01

To compare the effects of Roux-en-Y gastric bypass (RYGBP)procedures preserving different gastric volume on blood glucose of rats with non-obese type 2 diabetes. A total of 36 Goto-Kakizaki rats randomly underwent one of the following procedures: gastric bypass with different types of anastomosis including the Roux-en-Y of total stomach excision(n=12), the Roux-en-Y of partial stomach excision(n=12) and the Roux-en-Y of stomach preservation(n=12). Rats were observed for 24 weeks after surgery. Body weight, food intake and fasting blood glucose level were tested at 0(preoperative), 1, 3, 6, 12, 24 weeks. Hemoglobin A1c(HbA1c) level was measured at 0, 12, 24 weeks and glucose tolerance test (OGTT) was performed in conscious rats before (baseline) and then 30, 60, 120, and 180 minutes. Change of blood glucose over time was depicted. Area under curve(AUC) of glucose tolerance were calculated. Compared with preoperative levels, the weight and food intake of all the rats were significantly decreased at 1 week after surgery(P<0.01). At 3 weeks after operation, the weight and food intake were significantly increased compared with 1 week after operation in the Roux-en-Y of partial stomach excision and the Roux-en-Y of stomach retention(P<0.01). In the Roux-en-Y of total stomach excision, the weight and food intake were significantly lower compared with other two groups(P<0.05). At 24 weeks after operation, the levels of fasting blood glucose were (7.3 ± 1.5), (7.5 ± 2.0) and (8.3 ± 1.3) mmol/L, which were lower than the preoperative levels [(13.2 ± 1.6), (13.6 ± 2.5) and (12.9 ± 2.0) mmol/L, P<0.01] in the three groups. There were no significant differences among the three groups(P>0.05). At 24 weeks after operation, the HbA1c levels were(6.3 ± 1.3)%, (6.4 ± 2.0)% and (7.0 ± 1.3)%, which were lower than the preoperative level[(10.2 ± 2.6)%, (9.6 ± 2.5) and (9.9 ± 2.0)%, P<0.01]. There were no significant differences among the three groups(P>0.05). The trend of the glucose tolerance test and AUC were similar in the three groups after operation. Roux-en-Y gastric bypass in non-obese diabetic rats is effective in terms of glucose control and the efficacy of gastric bypass has no obvious association with the stomach volume.

Activation of Latent Dihydroorotase from Aquifex aeolicus by Pressure*

PubMed Central

Hervé, Guy; Evans, Hedeel Guy; Fernado, Roshini; Patel, Chandni; Hachem, Fatme; Evans, David R.

2017-01-01

Elevated hydrostatic pressure was used to probe conformational changes of Aquifex aeolicus dihydroorotase (DHO), which catalyzes the third step in de novo pyrimidine biosynthesis. The isolated protein, a 45-kDa monomer, lacks catalytic activity but becomes active upon formation of a dodecameric complex with aspartate transcarbamoylase (ATC). X-ray crystallographic studies of the isolated DHO and of the complex showed that association induces several major conformational changes in the DHO structure. In the isolated DHO, a flexible loop occludes the active site blocking the access of substrates. The loop is mostly disordered but is tethered to the active site region by several electrostatic and hydrogen bonds. This loop becomes ordered and is displaced from the active site upon formation of DHO-ATC complex. The application of pressure to the complex causes its time-dependent dissociation and the loss of both DHO and ATC activities. Pressure induced irreversible dissociation of the obligate ATC trimer, and as a consequence the DHO is also inactivated. However, moderate hydrostatic pressure applied to the isolated DHO subunit mimics the complex formation and reversibly activates the isolated subunit in the absence of ATC, suggesting that the loop has been displaced from the active site. This effect of pressure is explained by the negative volume change associated with the disruption of ionic interactions and exposure of ionized amino acids to the solvent (electrostriction). The interpretation that the loop is relocated by pressure was validated by site-directed mutagenesis and by inhibition by small peptides that mimic the loop residues. PMID:27746403

High Torque-to-Inertia Servo System for Stabilizing Sensor Systems. Candidate Systems Include Missile Guidance, Surveillance, and Tracking

DTIC Science & Technology

1980-04-01

specifications ... 3-10 25. Typical isolation curve ... 3-12 26. Servo amp/motor/load frequency response (inner gimbal) ... 4-3 27. Slave loop ( open loop...slave loop ( open loop) frequency response (inner gimbal) . . . 4-4 30. Slave loop (closed loop) frequency response (inner gimbal) ... 4-5 3 . Slave...loop inner gimbal time response ... 4-5 32. Servo amp/motor/load frequency response (outer gimbal) ... 4-6 33. Slave loop ( open loop) uncompensated

Outcomes for jejunal interposition reconstruction compared with Roux-en-Y anastomosis: A meta-analysis.

PubMed

Fan, Kai-Xi; Xu, Zhong-Fa; Wang, Mei-Rong; Li, Dao-Tang; Yang, Xiang-Shan; Guo, Jing

2015-03-14

To compare the clinical outcomes between jejunal interposition reconstruction and Roux-en-Y anastomosis after total gastrostomy in patients with gastric cancer. A systematic literature search was conducted by two independent researchers on PubMed, EMBASE, the Cochrane Library, Google Scholar, and other English literature databases, as well as the Chinese Academic Journal, Chinese Biomedical Literature Database, and other Chinese literature databases using "Gastrostomy", "Roux-en-Y", and "Interposition" as keywords. Data extraction and verification were performed on the literature included in this study. RevMan 5.2 software was used for data processing. A fixed-effects model was applied in the absence of heterogeneity between studies. A random effects model was applied in the presence of heterogeneity between studies. Ten studies with a total of 762 gastric cancer patients who underwent total gastrostomy were included in this study. Among them, 357 received jejunal interposition reconstruction after total gastrostomy, and 405 received Roux-en-Y anastomosis. Compared with Roux-en-Y anastomosis, jejunal interposition reconstruction significantly decreased the incidence of dumping syndrome (OR = 0.18, 95%CI: 0.10-0.31; P < 0.001), increased the prognostic nutritional index [weighted mean difference (WMD) = 6.02, 95%CI: 1.82-10.22; P < 0.001], and improved the degree of postoperative weight loss [WMD = 2.47, 95%CI: -3.19-(-1.75); P < 0.001]. However, there is no statistically significant difference in operative time, hospital stay, or incidence of reflux esophagitis. Compared with Roux-en-Y anastomosis, patients who underwent jejunal interposition reconstruction after total gastrostomy had a lower risk of postoperative long-term complications and improved life quality.

Roux-en-Y gastric bypass improves glucose homeostasis, reduces oxidative stress and inflammation in livers of obese rats and in Kupffer cells via an AMPK-dependent pathway.

PubMed

Peng, Yanhua; Li, James Zongyu; You, Min; Murr, Michel M

2017-07-01

Oxidative stress and inflammation are implicated in the pathogenesis of steatohepatitis. We hypothesize that Roux-en-Y gastric bypass reduces oxidative stress and inflammation in the liver of obese rats via activation of AMPK-α. Obese Sprague-Dawley male rats underwent either sham operation or Roux-en-Y gastric bypass. Hepatic TNF-α, NF-κB, IRS-2, PI3 kinase, PKC-ζ, NOX2, and AMPK-α were measured. Mechanistic studies were done in a rat Kupffer cell line (RKC1) that was treated with free fatty acids to mimic lipotoxicity and then transfected with AMPK-α siRNA. Reactive oxygen species, TNF-α, NF-κB, AMPK-α, p-AMPK-α, PPAR-γ, and NOX2 were measured. A t test was used. Roux-en-Y gastric bypass lowered nonfasting serum glucose, improved the glucose tolerance test, and induced IRS2/PI3 kinase interaction. Additionally, Roux-en-Y gastric bypass decreased hepatic NOX2, PKC-ζ, TNF-α expression and activation of NF-κB. Free fatty acids increased reactive oxygen species, TNF-α protein, NOX2 protein, and activated NF-κB. Rosiglitazone attenuated the free fatty acids-induced increase in reactive oxygen species, TNF-α, NOX2, and NF-κB; blocking AMPK-α by siRNA abolished the effects of rosiglitazone. Roux-en-Y gastric bypass exhibits antidiabetic properties and is associated with downregulation of proinflammation genes and oxidative stress in the liver and within Kupffer cells via activation of AMPK-α. Copyright © 2017 Elsevier Inc. All rights reserved.

Revision Roux-en-Y Gastric Bypass to Biliopancreatic Long-Limb Gastric Bypass for Inadequate Weight Response: Case Series and Analysis.

PubMed

Buchwald, Henry; Oien, Danette M

2017-09-01

The long-limb Roux-en-Y gastric bypass (LLRYGB) was introduced in 1987 as a salvage operation for inadequate weight loss after a standard Roux-en-Y gastric bypass (RYGB). We report on 53 consecutive patients (44 females) with conversion of a failed RYGB to a LLRYGB performed by a single surgeon between 2002 and 2014. No patient had an ascertainable anatomic abnormality to explain his/her weight regain. LLRYGB revision consisted of a 75-cm to 100-cm alimentary Roux limb and a 75-cm to 100-cm common channel; after 2011, in suitable patients, the Roux limb was lengthened to greater than 250 cm. Average values for weight (lbs) were as follows: pre-original RYGB = 329; lowest measured after RYGB = 196; at time of LLRYGB = 285; and at 1, 2, 3, 4, >5 years post LLRYGB = 225, 207, 199, 197, 195, for a sustained weight loss >90 lbs. Average values for BMI (kg/m 2 ) were as follows: pre-original RYGB = 54.3; lowest measured after RYGB = 32.3; at time of LLRYGB = 47.2; and at 1, 2, 3, 4, >5 years post LLRYGB = 37.1, 34.4, 33.0, 32.8, 31.4, for a sustained BMI reduction >16.5 kg/m 2 . Zero operative mortality; 3 (5.7%) late deaths; 7 (13.2%) 30-day complications; 33 (62.3%) long-term complications with 23 (43.4%) needing TPN; and 14 (26.4%) requiring operative revision. A salvage LLRYGB procedure can be performed safely and is weight successful, but fraught with long-term nutritional problems and a high necessity for revision. A Roux segment over 250 cm may improve outcomes.

New anastomosis technique for (laparoscopic) instrumental small-diameter anastomosis.

PubMed

Schöb, O; Schmid, R; Schlumpf, R; Klotz, H P; Spiess, M; Largiadèr, F

1995-04-01

This study presents a new technique for visceral anastomosis. The principle consists of connecting the two parts to be anastomosed around a reabsorbable stent which is transluminally introduced into small-diameter viscus, where it is fixed. Advancing a larger tube along the axis of the machine, the larger, perforated viscus is inverted and pulled over the stent, and finally a rubber band pops off the machine endoluminally in order to fix the intestinal walls in seroserosal contact onto the stent. To evaluate this "micro" anastomosis, a biliary bypass (choledochojejunostomy and roux-en-y-loop) was performed in ten pigs. Nine of ten animals showed biliary bypass with good runoff in contrast radiography and completely reabsorbed stent after a 3-month follow-up. Weight gain, bilirubin, and alkaline phosphatase were normal. This technology demonstrates a safe and quick way to perform instrumental "micro" anastomosis without remnant foreign material.

Small-bowel volvulus in late pregnancy due to internal hernia after laparoscopic Roux-en-Y gastric bypass.

PubMed

Naef, Markus; Mouton, Wolfgang G; Wagner, Hans E

2010-12-01

Internal hernias are a specific cause of acute abdominal pain and are a well-known complication after laparoscopic Roux-en-Y gastric bypass for morbid obesity. Although internal hernias are a rare cause of intestinal obstruction, they may evolve towards serious complications, such as extensive bowel ischemia and gangrene, with the need for bowel resection and sometimes for a challenging reconstruction of intestinal continuity. The antecolic position of the Roux limb is associated with a decrease in the incidence of small-bowel obstruction and internal hernias. The best prevention of the formation of these hernias is probably by closure of potential mesenteric defects at the initial operation with a non-absorbable running suture. We present a patient in late pregnancy with a small-bowel volvulus following laparoscopic Roux-en-Y gastric bypass for morbid obesity and discuss the available literature. For a favorable obstetric and neonatal outcome, it is crucial not to delay surgical exploration and an emergency operation usually is mandatory.

Linitis plastica of the bypassed stomach 7 years after Roux-en-Y gastric bypass: a case report.

PubMed

Haenen, Filip Wn; Gys, Ben; Moreels, Tom; Michielsen, Maartje; Gys, Tobie; Lafullarde, Thierry

2017-12-01

Laparoscopic Roux-en-Y gastric bypass (RYGB) is currently the preferred surgical procedure to treat morbid obesity. It has proven its effects on excess weight loss and its positive effect on comorbidities. One of the main issues, however, is the post-operative evaluation of the bypassed gastric remnant. In literature, cancer of the excluded stomach after RYGB is rare. We describe the case of a 52-year-old woman with gastric linitis plastica in the bypassed stomach after Roux-en-Y gastric bypass, diagnosed by means of laparoscopy and Single-Balloon enteroscopy, and it is clinical importance. Linitis plastica of the excluded stomach after RYGB is a very rare entity. This case report shows the importance of long-term post-operative follow-up, and the importance of single-balloon enteroscopy for visualization of the bypassed stomach remnant, when other investigations remain without results. This case report is only the second report of a linitis plastica in the bypassed stomach after Roux-en-Y gastric bypass.

Deliver a set of tools for resolving bad inductive loops and correcting bad data.

DOT National Transportation Integrated Search

2012-04-01

This project prototyped and demonstrated procedures to find and mitigate loop detector errors, and to derive more valuable data from loops. Specifically, methods were developed to find and isolate out loop data which is "bad" or invalid, so that miti...

Deliver a set of tools for resolving bad inductive loops and correcting bad data

DOT National Transportation Integrated Search

2012-04-10

This project prototyped and demonstrated procedures to find and mitigate loop detector errors, and to derive more valuable data from loops. Specifically, methods were developed to find and isolate out loop data which is "bad" or invalid, so that miti...

Functional jejunal interposition, a reconstruction procedure, promotes functional outcomes after total gastrectomy.

PubMed

Ding, Xuewei; Yan, Fang; Liang, Han; Xue, Qiang; Zhang, Kuo; Li, Hui; Ren, Xiubao; Hao, Xishan

2015-04-15

Functional jejunal interposition (FJI) has been applied as a reconstruction procedure to maintain the jejunal continuity and duodenal food passage after total gastrectomy in patients with gastric cancer. The purpose of this study was to evaluate clinical efficacy of the FJI procedure by comparing the functional outcomes of FJI to Roux-en-Y after total gastrectomy in gastric cancer patients, and investigate physiologic mechanisms by which FJI exerts beneficial outcomes in beagles. Patients with stage I-IV gastric cancer without metastasis and recurrence one year after surgery were enrolled in this retrospective study. Seventy one patients received FJI and seventy nine patients received Roux-en-Y after total gastrectomy. We evaluated the nutritional status at three and twelve months and incidence of complications up to twelve months after surgery. Beagles receiving sham operation, FJI, or Roux-en-Y after total gastrectomy were sacrificed forty eight hours postoperatively. Beagles were gavaged with active carbon for evaluating the intestinal transit rate. Intestinal tissues from the duodenojejunal anastomosis were collected for examining interstitial cells of Cajal (ICC), inflammation, and apoptosis. Compared to the bodyweight before surgery, the bodyweight loss at three and twelve months after surgery in patients receiving FJI was significant less than that in patients with Roux-en-Y. Patients with the FJI procedure showed significant increase of blood hemoglobin and total protein, compared to those at one month after surgery, and the prognostic nutrition index scores at three and twelve months after surgery. The incidence rates of post-operative complications, including reflux esophagitis, dumping syndrome, and Roux-en-Y syndrome were decreased in patients with FJI. Compared to beagles receiving Roux-en-Y, more ICC in the intestinal submuocsa, less intestinal epithelial cell apoptosis, and decreased inflammation in serosal side of the intestine were found in the FJI group. The intestinal transit rate in FJI group was lower than that in Roux-en Y group, indicating that FJI benefits food storage. The FJI procedure promotes nutritional recovery and decreases post-operative complications in gastric cancer patients after total gastrectomy, which may be through ameliorating intestinal inflammation and damage and reducing ICC loss to preserve food reservoir function and intestinal motility.

Outcomes of Mini vs Roux-en-Y gastric bypass: A meta-analysis and systematic review.

PubMed

Wang, Fu-Gang; Yan, Wen-Mao; Yan, Ming; Song, Mao-Min

2018-05-10

Mini gastric bypass has been proved to be capable of achieving excellent metabolic results by numerous published studies. Compared to Roux-en-Y gastric bypass, mini gastric bypass is a technically simpler and reversible procedure. However, comparative outcomes of the effectiveness between Mini gastric bypass and Roux-en-Y gastric bypass remain unclear. A systematic literature search was performed in Pubmed, Embase, Cochrane library from inception to February 9, 2018. For assessment of method quality, NOS (Newcastle-Ottawa Scale) and Cochrane Collaboration's tool for assessing risk of bias were used for cohort study and randomized controlled trials, respectively. The meta-analysis was performed by RevMan 5.3 software. 10 cohort studies and 1 randomized controlled trial was included in our meta-analysis. The method quality of the 10 cohort studies was proved as high quality according to the Newcastle-Ottawa Scale. The randomized controlled trial was proved to have a low risk of bias according to Cochrane Collaboration's assessment. Patients receiving mini-gastric bypass had multiple advantageous indexes as compared with patients receiving Roux-en-Y gastric bypass. Examples include: a higher 1-year EWL% (P < 0.05), higher 2-year EWL% (P < 0.05), higher type 2 diabetes mellitus remission rate, as well as a shorter operation time (P < 0.05). No significant statistical difference was observed in hypertension remission rate, mortality, leakage rate, GERD rate, or hospital stay between mini gastric bypass and Roux-en-Y gastric bypass. Mini gastric bypass seems to be a simpler procedure with a better weight reduction effect. This seems to also be the case regarding remission rates of type 2 diabetes mellitus when using Mini gastric bypass in comparison to Roux-en-Y gastric bypass. A small sample size and biased data may have influenced the stability of our results. In light of this, surgeons should treat our results in a conservative way. Larger sample size and multi-center randomized control trials are needed to compare the effectiveness and safety between mini-gastric bypass and Roux-en-Y gastric bypass. Copyright © 2018. Published by Elsevier Ltd.

Biliary reconstruction options for bile duct stricture in patients with prior Roux-en-Y reconstruction.

PubMed

Shah, Mihir M; Martin, Benjamin M; Stetler, Jamil L; Patel, Ankit D; Davis, S Scott; Lin, Edward; Sarmiento, Juan M

2017-09-01

Comprehensive description with illustrations of the 4 biliary reconstruction options for bile duct injury in patients with history of Roux-en-Y gastric bypass. Copyright © 2017 American Society for Bariatric Surgery. Published by Elsevier Inc. All rights reserved.

"Candy cane syndrome:" an underappreciated cause of abdominal pain and nausea after Roux-en-Y gastric bypass surgery.

PubMed

Aryaie, Amir H; Fayezizadeh, Mojtaba; Wen, Yuxiang; Alshehri, Mohammed; Abbas, Mujjahid; Khaitan, Leena

2017-09-01

"Candy cane" syndrome (a blind afferent Roux limb at the gastrojejunostomy) has been implicated as a cause of abdominal pain, nausea, and emesis after Roux-n-Y gastric bypass (RYGB) but remains poorly described. To report that "candy cane" syndrome is real and can be treated effectively with revisional bariatric surgery SETTING: All patients underwent "candy cane" resection at University Hospitals of Cleveland. All patients who underwent resection of the "candy cane" between January 2011 and July 2015 were included. All had preoperative workup to identify "candy cane" syndrome. Demographic data; pre-, peri-, and postoperative symptoms; data regarding hospitalization; and postoperative weight loss were assessed through retrospective chart review. Data were analyzed using Student's t test and χ 2 analysis where appropriate. Nineteen patients had resection of the "candy cane" (94% female, mean age 50±11 yr), within 3 to 11 years after initial RYGB. Primary presenting symptoms were epigastric abdominal pain (68%) and nausea/vomiting (32%), particularly with fibrous foods and meats. On upper gastrointestinal study and endoscopy, the afferent blind limb was the most direct outlet from the gastrojejunostomy. Only patients with these preoperative findings were deemed to have "candy cane" syndrome. Eighteen (94%) cases were completed laparoscopically. Length of the "candy cane" ranged from 3 to 22 cm. Median length of stay was 1 day. After resection, 18 (94%) patients had complete resolution of their symptoms (P<.001). Mean body mass index decreased from 33.9±6.1 kg/m 2 preoperatively to 31.7±5.6 kg/m 2 at 6 months (17.4% excess weight loss) and 30.5±6.9 kg/m 2 at 1 year (25.7% excess weight loss). The average length of latest follow-up was 20.7 months. "Candy cane" syndrome is a real phenomenon that can be managed safely with excellent outcomes with resection of the blind afferent limb. A thorough diagnostic workup is paramount to proper identification of this syndrome. Surgeons should minimize the size of the blind afferent loop left at the time of initial RYGB. Copyright © 2017 American Society for Bariatric Surgery. Published by Elsevier Inc. All rights reserved.

Comparison Between Billroth-II with Braun and Roux-en-Y Reconstruction After Laparoscopic Distal Gastrectomy.

PubMed

In Choi, Chang; Baek, Dong Hoon; Lee, Si Hak; Hwang, Sun Hwi; Kim, Dae Hwan; Kim, Kwang Ha; Jeon, Tae Yong; Kim, Dong Heon

2016-06-01

This study aims to compare the effectiveness of Billroth-II with Braun and Roux-en-Y reconstruction after laparoscopic distal gastrectomy. From April 2010 to August 2012, 66 patients underwent laparoscopic distal gastrectomy (Billroth-II with Braun reconstruction, 26; Roux-en-Y, 40). The patients' data were collected prospectively and reviewed retrospectively. The mean operation and reconstruction times were statistically shorter for Billroth-II with Braun reconstruction than Roux-en-Y (198.1 ± 33.0 vs. 242.3 ± 58.1 min, p = 0.001). One case of postoperative stricture was observed in each group. One case each of intra-abdominal abscess and delayed gastric emptying occurred in the Billroth-II with Braun group. At 1 year postoperatively, gastric residue and reflux esophagitis were not significantly different between the groups. Gastritis and bile reflux were more frequently observed in the Billroth-II with Braun group (p = 0.004 and p < 0.001, respectively). At 2 years postoperatively, gastric residue was not significantly different, but gastritis, bile reflux, and esophagitis were more frequent in the Billroth-II with Braun group (p = 0.029, p < 0.001, and p = 0.036, respectively). The postoperative effectiveness of Roux-en-Y reconstruction may be superior to Billroth-II with Braun reconstruction after laparoscopic distal gastrectomy.

Jejunogastric intussusception after distal gastrectomy with Roux-en-Y reconstruction: A case report.

PubMed

Kawano, Fumiaki; Tashiro, Kousei; Nakao, Hironobu; Fujii, Yoshirou; Ikeda, Takuto; Takeno, Shinsuke; Nakamura, Kunihide; Nanashima, Atsushi

2018-01-01

Jejunogastric intussusception is a rare complication after gastric operation. Intussusception after gastric operation occurs mostly at the gastrojejunal anastomosis site and Braun anastomosis site of Billroth II reconstruction, and at the Y anastomosis site of Roux-en-Y reconstruction. However, jejunogastric intussusception after distal gastrectomy with Roux-en-Y reconstruction is very rare. We report a surgical case of jejunogastric intussusception after distal gastrectomy for gastric cancer treatment. An 82-year-old woman underwent laparoscopic distal gastrectomy for early gastric cancer treatment. Reconstruction was performed using Roux-en-Y anastomosis. Oral intake was started on postoperative day 4, however vomiting and high-grade fever occurred on postoperative day 12, after which oral intake became difficult. Anastomotic stenosis of the gastrojejunostomy was suspected, and various examinations were performed. Gastroendoscopy and computed tomography revealed an elevated lesion with ring-like folds protruding through the anastomosis site into the remnant stomach. Reoperation was performed on postoperative day 28 after a diagnosis of jejunogastric intussusception was made. It failed to reduce the intussusception, so partial resection of the gastrojejunal anastomosis was performed and Roux-en-Y reconstruction was repeated. Reconstruction was conducted after taking into consideration the recurrence of intussusception. Jejunogastric intussusceptions after distal gastrectomy is a rare complication; however, when it occurs, early diagnosis and appropriate management are necessary. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

Laparoscopic Conversion of One Anastomosis Gastric Bypass to a Standard Roux-en-Y Gastric Bypass.

PubMed

Amor, Imed Ben; Petrucciani, Niccolo; Kassir, Radwan; Al Munifi, Abdullah; Piche, Thierry; Debs, Tarek; Gugenheim, Jean

2017-05-01

One anastomosis gastric bypass (OAGB) demonstrated results similar to traditional Roux-en-Y procedures [1-3], in terms of weight loss and resolution of obesity-related comorbidities. The main controversy regarding OAGB is the concern for an association between biliary alkaline gastritis and esophageal or gastric cancer raised by some studies [4]. We present the case of a 51-year-old woman with a BMI of 41 kg/m2 who underwent a laparoscopic OAGB in 2014. One year later, she consulted for recurrent heartburns. An upper GI endoscopy showed pouchitis and bile reflux in the esophagus. Medical treatment of gastroesophageal reflux disease was ineffective. We decided to convert the OAGB to a Roux-en-Y gastric bypass (RYGB). In this video, we show how to revise an OAGB to treat chronic bile reflux, by converting the procedure to a standard RYGB. The intervention starts by restoring the normal anatomy of the small bowel, with the resection of the gastrojejunal anastomosis, which was located at 250-cm du Treitz's ligament. Then, the gastric pouch is created. A standard Roux-en-Y gastric bypass is performed. The resection of the gastrojejunal anastomosis allows fashioning the Roux-en-Y limb with the classical measures. This technique allows a conversion to a standard RYGB and is effective in treating the biliary reflux.

Vibration isolation using extreme geometric nonlinearity

NASA Astrophysics Data System (ADS)

Virgin, L. N.; Santillan, S. T.; Plaut, R. H.

2008-08-01

A highly deformed, slender beam (or strip), attached to a vertically oscillating base, is used in a vibration isolation application to reduce the motion of a supported mass. The isolator is a thin strip that is bent so that the two ends are clamped together, forming a loop. The clamped ends are attached to an excitation source and the supported system is attached at the loop midpoint directly above the base. The strip is modeled as an elastica, and the resulting nonlinear boundary value problem is solved numerically using a shooting method. First the equilibrium shapes of the loop with varying static loads and lengths are studied. The analysis reveals a large degree of stiffness tunability; the stiffness is dependent on the geometric configuration, which itself is determined by the supported mass, loop length, and loop self-weight. Free vibration frequencies and mode shapes are also found. Finally, the case of forced vibration is studied, and the displacement transmissibility over a large range of forcing frequencies is determined for varying parameter values. Experiments using polycarbonate strips are conducted to verify equilibrium and dynamic behavior.

A 10 year follow-up study after Roux-Elmslie-Trillat treatment for cases of patellar instability.

PubMed

Endres, Stefan; Wilke, Axel

2011-02-18

A retrospective study concerning patients presenting with patella instability, treated using a Roux-Elmslie-Trillat reconstruction operation and followed up for 10 years following surgery, is presented. Pre-operative and follow-up radiographic evaluation included the weight-bearing anteroposterior and merchant views. Evaluation was carried out using the Insall-Salvati index, sulcus and congruence angle. The Roux-Elmslie-Trillat reconstruction operation was performed on 18 patients. The clinical evaluation at follow-up was performed using the Knee-Society-Score (KSS) and Tegner-Score. Subjective results of the operation were classed as excellent or good in 16 of the 18 patients ten years after surgery; persistent instability of the patella was recorded in only one of the 18 patients. The majority of patients returned to the same level of sporting activity after surgery as they had participated in before injury. The Roux-Elmslie-Trillat procedure could be recommended in cases presenting with an increased q-angle, trochlea dysplasia or failed soft tissue surgery. In the present study the majority of patients report a return to previous sporting activity ten years after surgery.

A case of retrograde intussusception at Roux-en-Y anastomosis 10 years after total gastrectomy: review of the literature.

PubMed

Kitasato, Yuhei; Midorikawa, Ryuta; Uchino, Yoshihiro; Saku, Shuko; Minami, Taizan; Shirahama, Takahisa; Kiyomatsu, Kazumitsu; Okuda, Koji; Akagi, Yoshito; Tanaka, Hiroyuki

2016-12-01

A 63-year-old man, who had undergone total gastrectomy and Roux-en-Y reconstruction for gastric cancer 10 years previously, was admitted to our hospital with complaints of abdominal pain, palpable abdominal tumor, and hematemesis. On admission, the abdominal tenderness was improving and no abdominal tumor was palpable. Mild inflammatory changes and anemia were noted on blood examination. Abdominal computed tomography revealed a tumor with a layered structure in the left abdomen. The patient was diagnosed with intestinal obstruction secondary to intussusception, and surgery was performed. Retrograde intussusception was found at the site of the Y anastomosis. We conducted manual reduction using the Hutchinson procedure. The intestinal color after the reduction was good, and no intestinal resection was required. Postoperative recovery was uneventful, and the patient was discharged 12 days after surgery. Reports of jejunal intussusception after total gastrectomy with Roux-en-Y reconstruction are relatively rare. Here, we report a case of jejunal intussusception after total gastrectomy with Roux-en-Y reconstruction.

A Simple Technique for Jejunojejunal Revision in Laparoscopic Roux-en-Y Gastric Bypass.

PubMed

Spivak, Hadar

2015-12-01

The lengths of the bypassed segments in the initial laparoscopic roux-en-Y gastric bypass (LRYGB) are usually a matter of the individual surgeon's routine. The literature is inconclusive about the association between the Roux limbs' length and weight-loss or malabsorption (Stefanidis et al. Obes Surg. 21(1):119-24, 2011); (Rawlins et al. Surg Obes Relat Dis. 7(1):45-9, 2011). However, jejunojejunal anastomosis (JJ) "redo" and Roux limb length revision could be considered for patients with a very short Roux limb and weight loss failure or for short common channel and malabsorption. Complications of JJ may also require revision. In over 1000 LRYGBs since 2001, eight patients required JJ revision for failure to lose enough weight (n = 6), malabsorption (n = 1), and stricture (n = 1). Instead of completely taking down the JJ, a simple technique was evolved to keep the enteric limb continuity. In a following step, the biliopancreatic limbs have been transected from the JJ and reconnected proximal (for malabsorption) or distal (for weight loss failure). In this video, a step-by-step the laparoscopic technique for JJ revision and relocating the biliopancreatic limb is presented. Procedure takes 40-60 min to perform using four trocars and the hospital stay was 1-2 nights. No complications occurred during the procedures or postoperative period. Laparoscopic revision of JJ is feasible and safe and should be part of surgeons' options on the long-term management of patients post LRYGB.

Randomized controlled trial of uncut Roux-en-Y vs Billroth II reconstruction after distal gastrectomy for gastric cancer: Which technique is better for avoiding biliary reflux and gastritis?

PubMed

Yang, Dong; He, Liang; Tong, Wei-Hua; Jia, Zhi-Fang; Su, Tong-Rong; Wang, Quan

2017-09-14

To identify which technique is better for avoiding biliary reflux and gastritis between uncut Roux-en-Y and Billroth II reconstruction. A total of 158 patients who underwent laparoscopy-assisted distal gastrectomy for gastric cancer at the First Hospital of Jilin University (Changchun, China) between February 2015 and February 2016 were randomized into two groups: uncut Roux-en-Y (group U) and Billroth II group (group B). Postoperative complications and relevant clinical data were compared between the two groups. According to the randomization table, each group included 79 patients. There was no significant difference in postoperative complications between groups U and B (7.6% vs 10.1%, P = 0.576). During the postoperative period, group U stomach pH values were lower than 7 and group B pH values were higher than 7. After 1 year of follow-up, group B presented a higher incidence of biliary reflux and alkaline gastritis. However, histopathology did not show a significant difference in gastritis diagnosis ( P = 0.278), and the amount of residual food and gain of weight between the groups were also not significantly different. At 3 mo there was no evidence of partial recanalization of uncut staple line, but at 1 year the incidence was 13%. Compared with Billroth II reconstruction, uncut Roux-en-Y reconstruction is secure and feasible, and can effectively reduce the incidence of alkaline reflux, residual gastritis, and heartburn. Despite the incidence of recanalization, uncut Roux-en-Y should be widely applied.

Laparoscopic Conversion of One Anastomosis Gastric Bypass to Roux-en-Y Gastric Bypass for Chronic Bile Reflux.

PubMed

Facchiano, Enrico; Leuratti, Luca; Veltri, Marco; Lucchese, Marcello

2016-03-01

One anastomosis gastric bypass (OAGB) demonstrated similar results to traditional Roux-en-Y procedures. A possible concern is how to manage a chronic bile reflux when medical therapy results ineffective. Revision of the gastro-jejunal anastomosis, obtaining a Roux-en-Y reconstruction, has already been proposed, but technical details have not been elucidated yet. This video shows how to revise a 200-cm OAGB to treat chronic bile reflux, by converting the procedure to Roux-en-Y, having a short gastric pouch and a long efferent limb. A 51-year-old patient complained of recurrent heartburns 2 months after OAGB. A gastroscopy witnessed the presence of a 6-cm long gastric pouch with pouchitis and bile reflux in esophagus. Specific medications were ineffective. He underwent a revisional laparoscopic procedure. The efferent limb was measured and consisted of 650 cm. The afferent limb was then divided next to the previous gastro-jejunal anastomosis and a jejuno-jejunal anastomosis was performed distally at 70 cm on the alimentary limb. Total operative time was 50 min. The postoperative stay was uneventful and the patient was discharged in postoperative day four. At 6 months follow-up he is still free of medications without symptoms. The ideal scenario for the presented technique is the finding of a long efferent limb, in order to fashion a Roux-en-Y limb without the risk of postoperative malabsorption. To reach this goal, we suggest the measurement of the whole small bowel intra-operatively, in order to assess the length of the common channel left in place.

[A Case of Laparoscopic Repair of Internal Hernia after Laparoscope-Assisted Distal Gastrectomy with Antecolic Roux-en-Y Reconstruction].

PubMed

Maezawa, Yukio; Cho, Haruhiko; Kano, Kazuki; Nakajima, Tetsushi; Ikeda, Kousuke; Yamada, Takanobu; Sato, Tsutomu; Ohshima, Takashi; Rino, Yasushi; Masuda, Munetaka; Ogata, Takashi; Yoshikawa, Takaki

2017-10-01

A 72-year-old woman had undergone laparoscope-assisted distal gastrectomy with D1 plus lymph node dissection and antecolic Roux-en-Y reconstruction for early gastric cancer. She visited our department outpatient clinic with left upper abdominal pain 1 year and 9 months after the surgery. CT revealed a spiral sign of the superior mesenteric arteriovenous branch. An internal hernia was suspected on hospitalization. Although abdominal symptoms were relieved by conservative treatment, the hernia persisted. Laparoscopic surgery was performed and revealed that almost entire small intestine had been affected due to Petersen's defect. Since no ischemic changes were observed, the defect was repaired laparoscopically with suture closure. There has been no recurrence of internal hernia after the laparoscopic surgery. Internal hernia after distal gastrectomy is relatively rare. However, the risk of internal hernia is high due to the gap between the elevated jejunum and transverse colon mesentery in Roux-en-Y reconstruction and can lead to intestinal necrosis. Since an internal hernia can occur in patients who have undergone gastric resection with Roux-en-Y reconstruction, suture closure of Petersen's defect should be performed to prevent this occurrence.

Laparoscopic stomach-partitioning gastrojejunostomy with reduced-port techniques for unresectable distal gastric cancer.

PubMed

Hirahara, Noriyuki; Matsubara, Takeshi; Hyakudomi, Ryoji; Hari, Yoko; Fujii, Yusuke; Tajima, Yoshitsugu

2014-03-01

The improvement of quality of life is of great importance in managing patients with far-advanced gastric cancer. We report a new cure and less invasive method of creating a stomach-partitioning gastrojejunostomy in reduced-port laparoscopic surgery for unresectable gastric cancers with gastric outlet obstruction. A 2.5-cm vertical intraumbilical incision was made, and EZ Access (Hakko Co., Ltd., Tokyo, Japan) was placed. After pneumoperitoneum was created, an additional 5-mm trocar was inserted in the right upper abdomen. A gastrojejunostomy was performed in the form of an antiperistaltic side-to-side anastomosis, in which the jejunal loop was elevated in the antecolic route and anastomosed to the greater curvature of the stomach using an endoscopic linear stapler. The jejunal loop together with the stomach was dissected with additional linear staplers just proximal to the common entry hole so that a functional end-to-end gastrojejunostomy was completed. At the same time, the stomach was partitioned using a linear stapler to leave a 2-cm-wide lumen in the lesser curvature. Subsequently, jejunojejunostomy was performed 30 cm distal to the gastrojejunostomy, and the stomach-partitioning gastrojejunostomy resembling Roux-en Y anastomosis was completed. All patients resumed oral intake on the day of operation. Neither anastomotic leakage nor anastomotic stricture was observed. Our less invasive palliative operation offers the utmost priority to improve quality of life for patients with unresectable gastric cancer.

Solo Single-Incision Laparoscopic Resectional Roux-en-Y Gastric Bypass for Morbid Obesity with Metabolic Syndrome.

PubMed

Kang, So Hyun; Lee, Yoontaek; Park, Young Suk; Ahn, Sang-Hoon; Park, Do Joong; Kim, Hyung-Ho

2017-12-01

With the advancement of laparoscopic devices and surgical technology, the era of minimal invasive surgery has progressed to reduced-port surgery, and finally to single-incision laparoscopic surgery (SILS). Several reports show successful application of SILS to various types of bariatric surgery. Oftentimes, this requires a skilled and experienced scopist to perform the procedure. To overcome the technical difficulties of single-incision Roux-en-Y gastric bypass, a manual scope holder was used instead of an assistant scopist, greatly stabilizing the field of view. This allows the surgery to be performed at any time without being influenced by the need of a highly experienced scopist. In this report, we describe in detail the world's first solo single-incision laparoscopic resectional Roux-en-Y gastric bypass.

[Injuries of the extrahepatic bile ducts in laparoscopic cholecystectomy].

PubMed

Pătraşcu, Tr; Burcoş, Tr; Doran, H; Cristian, D; Brezean, I; Voiculescu, St; Catrina, E; Vereanu, I

2006-01-01

Laparoscopic cholecystectomy has become the "gold standard" for cholelithiasis. In laparoscopic technique, the incidence and the severity of injuries of the extrahepatic bile ducts are significantly higher (0-2,7%) than in open surgery (0,2-0,5%). The authors present a series of 18 patients with such lesions, operated between 1996 and 2005 in the surgical departments of 2 Clinical Hospitals: "Dr.I.Cantacuzino" and Coltea, from Bucharest. The injuries were: 2--of type A, 10--of type D and 6--of type E, according to Soper-Strasberg classification. There are analysed the causes and the circumstances in which these injuries have occurred, the clinical signs and imagistic findings and, most of all, their treatment. In complete transections of the common bile duct, a hepatico-jejuno-anastomosis using a Roux en Y-loop appears to be the best solution. It is emphasized the fact that an accurate diagnosis and surgical technique are essential for a favourable evolution. That's why these operations must be accomplished by experimented surgeons, from highly specialized departments.

Pancreaticojejuno anastomosis after pancreaticoduodenectomy: brief pathophysiological considerations for a rational surgical choice.

PubMed

Caronna, Roberto; Peparini, Nadia; Cosimo Russillo, Gabriele; Antonio Rogano, Adolfo; Dinatale, Giuseppe; Chirletti, Piero

2012-01-01

Introduction. The best pancreatic anastomosis technique after pancreaticoduodenectomy (PD) is still debated. Pancreatic fistula (PF) is the most important complication but is also related to postoperative bleedings and pancreatic remnant involution. We support pancreaticojejuno anastomosis (PJ) advantages describing our technique with brief technical considerations. Materials and Methods. 89 consecutive patients underwent PD with suprapyloric gastric resection and double loop reconstruction. Pancreaticojejunal end-to-end anastomosis was done by simple invagination with a single layer of interrupted pledget-supported Ticron stitches. Results. Pancreatic fistula occurred in seven patients (7.8%): six cases of grade A fistula resolved spontaneously, and in only one case of grade B fistula percutaneous drainage was necessary. Postoperative hemorrhage occurred in only two (2.2%) of 89 patients. Conclusion. Pancreaticojejunostomy with minor changes in anastomotic techniques can contribute to improvement of the outcome of Roux-en-Y reconstruction regarding PF and other related complications. The particular reconstruction reported seems also to preserve the pancreatic exocrine function.

Pancreaticojejuno Anastomosis after Pancreaticoduodenectomy: Brief Pathophysiological Considerations for a Rational Surgical Choice

PubMed Central

Caronna, Roberto; Peparini, Nadia; Cosimo Russillo, Gabriele; Antonio Rogano, Adolfo; Dinatale, Giuseppe; Chirletti, Piero

2012-01-01

Introduction. The best pancreatic anastomosis technique after pancreaticoduodenectomy (PD) is still debated. Pancreatic fistula (PF) is the most important complication but is also related to postoperative bleedings and pancreatic remnant involution. We support pancreaticojejuno anastomosis (PJ) advantages describing our technique with brief technical considerations. Materials and Methods. 89 consecutive patients underwent PD with suprapyloric gastric resection and double loop reconstruction. Pancreaticojejunal end-to-end anastomosis was done by simple invagination with a single layer of interrupted pledget-supported Ticron stitches. Results. Pancreatic fistula occurred in seven patients (7.8%): six cases of grade A fistula resolved spontaneously, and in only one case of grade B fistula percutaneous drainage was necessary. Postoperative hemorrhage occurred in only two (2.2%) of 89 patients. Conclusion. Pancreaticojejunostomy with minor changes in anastomotic techniques can contribute to improvement of the outcome of Roux-en-Y reconstruction regarding PF and other related complications. The particular reconstruction reported seems also to preserve the pancreatic exocrine function. PMID:22489265

Proximal bile duct tumors: surgical management with silastic transhepatic biliary stents.

PubMed Central

Cameron, J L; Broe, P; Zuidema, G D

1982-01-01

Over a nine-year period, 27 patients with proximal biliary tumors were operated upon. In ten of the 27 patients (37%) tumor resection including the hepatic bifurcation was possible, and bilateral hepaticojejunostomies were performed using silastic transhepatic biliary stents. In the remaining 17 patients the tumor was partially resected, dilated, or bypassed, and reconstruction to a Roux-en-Y-jejunal loop was carried out using silastic transhepatic biliary stents. Hospital mortality for those patients undergoing resection was zero, and for the entire group 4% (1/27). The mean bilirubin on admission was 13.2 mg/dl and after discharge fell to a mean of 1.5 mg/dl. Mean survival for the entire group is 18 months with 11 patients still alive. Mean survival for the first nine patients undergoing resection is 21 months with seven patients still alive (one for over 5 years). The 15 patients dying following discharge survived for a mean of 14 months. Images Fig. 1. Fig. 2. Fig. 3. PMID:7125728

Roux-en-Y duodenojejunostomy in the treatment of Bouveret syndrome.

PubMed

Erlandson, Michael D; Kim, Anthony W; Richter, Harry M; Myers, Jonathan A

2009-09-01

Bouveret syndrome is a rare complication of cholelithiasis occurring when a gallstone passes through a cholecystoduodenal or choledochoduodenal fistula and lodges in the pylorus or proximal duodenum causing a gastric outlet obstruction. The case of a 70-year-old male who developed Bouveret syndrome is presented, and the management of this presentation of gallstone ileus by Roux-en-Y duodenojejunostomy is discussed in detail.

Choledochoscopic high-frequency needle-knife electrotomy for treatment of anastomotic strictures after Roux-en-Y hepaticojejunostomy.

PubMed

Yang, Yu-Long; Zhang, Cheng; Wu, Ping; Ma, Yue-Feng; Li, Jing-Yi; Zhang, Hong-Wei; Shi, Li-Jun; Lin, Mei-Ju; Yu, Ying

2016-05-06

Anastomotic stricture is a complex and substantial complication following Roux-en-Y hepaticojejunostomy. Initially, endoscopic and percutaneous approaches are often attempted, but the gold standard remains surgical biliary reconstruction, especially for refractory stricture. However, this solution leaves much room for improvement, due to the challenging nature of the biliary reconstruction procedure, in which anastomotic stricture may still occur. To investigate the feasibility and effectiveness of choledochoscopic high-frequency needle-knife electrotomy as an intervention in the treatment of anastomotic strictures following Roux-en-Y hepaticojejunostomy. From February 2010 to October 2014, clinical data was collected and retrospectively compared for patients who underwent balloon dilation or/and choledochoscopic high-frequency needle-knife electrotomy for the treatment of anastomotic strictures after Roux-en-Y hepaticojejunostomy. A total of 38 patients underwent successful choledochoscopic treatment and all the anastomotic strictures were removed successfully, 19 of which were treated with electrotomy, 7 with balloon dilation, and 12 with both electrotomy and balloon dilation. Among these groups,the average operating times were 6.9 ± 2.4 min,10.1 ± 6.8 min, and 20.2 ± 13.5 min, respectively. The average stent supporting times were 6.3 ± 0.7 months, 6.5 ± 0.6 months, and 6.1 ± 0.4 respectively. The mean follow-up after stent removal was 42.1 ± 27.4 months, and in 26.3 % (5/19), 28.5 % (2/7) and 16.7 % (2/12) of cases, recurrent anastomotic stricture occurred. Of these 9 total patients with recurrent anastomotic, two patients were successfully rescued by full-covered self-expanding removable metal stents and 7 patients by electrotomy combined with balloon dilation. Choledochoscopic high-frequency needle-knife electrotomy is both feasible and safe in the treatment of anastomotic stricture after Roux-en-Y hepaticojejunostomy, with a similar long-term outcome to balloon dilation in treating anastomotic stricture after Roux-en-Y hepaticojejunostomy. A combination of choledochoscopic electrotomy concurrent with balloon dilation should be recommended based on the low rate of recurrence.

Design of PI Controlled Non Isolated Bidirectional DC to DC Converter for Electric Vehicle Application

NASA Astrophysics Data System (ADS)

Geetha, A.; Subramani, C.; Thamizh Thentral, T. M.; Krithika, V.; Usha, S.

2018-04-01

Non isolated Bidirectional DC-DC Converter (NIBDDC) is a good interface between DC source and inverter Fed induction motor drive. This paper deals with comparison between open loop and PI controlled Bidirectional DC to DC Converter Inverter System (BDDCIS). The modelling and control of BDDC is becomes an important issue. Open loop BDDCIS and closed loop PI controlled BDDCIS are designed, modelled and simulated using Matlab- simulink and their results are presented. The investigations indicate superior performance of PI controlled BDDCIS. The proposed BDDCIS has advantages like bidirectional power transfer ability, reduced hardware count and improved dynamic response.

Successful Treatment of an Unusual Case of FPLD2: The Role of Roux-en-Y Gastric Bypass-Case Report and Literature Review.

PubMed

Grundfest-Broniatowski, Sharon; Yan, JingLiang; Kroh, Matthew; Kilim, Holly; Stephenson, Andrew

2017-04-01

Familial partial lipodystrophy type 2 (FPLD2) is a rare disorder associated with LMNA gene mutations. It is usually marked by loss of subcutaneous fat on the limbs and trunk and severe insulin resistance. Scattered reports have indicated that Roux-en-Y bypass helps to control the diabetes mellitus in these patients. We present here a very unusual patient with FPLD2 who had life-threatening retroperitoneal and renal fat accumulation accompanied by bilateral renal cancers. Following cryotherapy of one renal cancer and a contralateral nephrectomy with debulking of the retroperitoneal fat, Roux-en-Y gastric bypass (RYGB) has successfully controlled the disease for 3 years. The clinical presentations and causes of FPLD are reviewed and the role of RYGB is discussed.

Routine upper gastrointestinal Gastrografin swallow after laparoscopic Roux-en-Y gastric bypass.

PubMed

Sims, Thomas L; Mullican, Mary A; Hamilton, Elizabeth C; Provost, David A; Jones, Daniel B

2003-02-01

Upper gastrointestinal (UGI) swallow radiographs following laparoscopic Roux-en-Y gastric bypass (LRYGBP) may detect an obstruction or an anastomotic leak. The aim of our study was to determine the efficacy of routine imaging following LRYGBP. Radiograph reports were reviewed for 201 consecutive LRYGBP operations between April 1999 and June 2001. UGI swallow used Gastrografin, static films, fluoroscopic video, and a delayed image at 10 minutes. Mean values with one standard deviation were tested for significance (P < 0.05) using the Mann-Whitney U test statistic. Of 198 available reports, UGI detected jejunal efferent (Roux) limb narrowing (n = 17), partial obstruction (n = 12), anastomotic leak (n = 3), complete bowel obstruction (n = 3), diverticulum (n = 1), hiatal hernia (n = 1), and proximal Roux limb narrowing (n = 1). A normal study was reported in 160 cases (81%). Partial obstruction resolved without intervention. Complete obstruction required re-operation. Compared to 6 patients who developed delayed leaks, early identification of a leak by routine UGI swallow resulted in a shorter hospital stay (mean 7.7 +/- 1.5 days vs 40.2 +/- 12.3 days, P < 0.03). Early intervention after UGI swallow may lessen morbidity. Routine UGI swallow following LRYGBP does not obviate the importance of close clinical follow-up.

Laparoscopic proximal Roux-en-Y gastrojejunal diversion in children: preliminary experience from a single center.

PubMed

Mattioli, Girolamo; Buffa, Piero; Gandullia, Paolo; Schiaffino, Maria Cristina; Avanzini, Stefano; Rapuzzi, Giovanni; Pini Prato, Alessio; Guida, Edoardo; Costanzo, Sara; Rossi, Valentina; Basile, Angelina; Montobbio, Giovanni; DellaRocca, Mirta; Mameli, Leila; Disma, Nicola; Pessagno, Alice; Tomà, Paolo; Jasonni, Vincenzo

2009-12-01

Neurologically impaired children (NIC) have a high risk of recurrence of gastroesophageal reflux (GER) following fundoplication. A postpyloric feeding tube may be useful when gastric emptying disorders occur; however, dislocation and difficulty in feeding management often require more aggressive procedures. Total esophagogastric dissociation (Bianchi's TEGD) is an alternative to the classic fundoplication procedure, whereas laparoscopic gastric bypass is a frequently performed procedure in morbid obesity, improving gastric outlet. The aim of this paper is to present a preliminary experience on the laparoscopic Roux-en-Y gastrojejunal bypass, associated with Nissen fundoplication and gastrostomy, to treat and prevent GER in NIC with gastric emptying disorders. Eight neurologically impaired children underwent surgical treatment because of feeding problems and pulmonary complications. The procedure included: 1) hiatoplasty, 2) Nissen fundoplication, 3) 20-cm Roux-en-Y gastrojejunal anastomosis and jejuno-jejunal anastomosis, and 4) gastrostomy. All cases were fed on postoperative day 3 without any intraoperative complications. One case developed an obstruction of the distal anastomosis due to adhesion and needed reoperation. Outcome was clinically evaluated with serial upper gastrointestinal contrast studies and endoscopies. Laparoscopic proximal Roux-en-Y gastrojejunal diversion, without gastric resection, is a safe, feasible procedure that improves gastric emptying and reduces the risk of GER recurrence. Yet, long-term results still have to be evaluated.

A single-centre experience of Roux-en-Y enteric drainage for pancreas transplantation.

PubMed

Amin, Irum; Butler, Andrew J; Defries, Gail; Russell, Neil K; Harper, Simon J F; Jah, Asif; Saeb-Parsy, Kourosh; Pettigrew, Gavin J; Watson, Christopher J E

2017-04-01

Exocrine drainage following pancreas transplantation can be achieved by drainage into the bladder or bowel, the latter typically by direct duodeno-jejunostomy; the use of Roux-en-Y enteric drainage is uncommon. We report a retrospective analysis of a single-centre experience of Roux-en-Y enteric drainage following pancreas transplantation. Over a 14-year period (2001-2015), 204 consecutive adult pancreas transplants were performed (96.6% simultaneous pancreas and kidney transplants), of which 26.0% were from donors after circulatory death (DCD). During a median follow-up of 67 months (range 13-183 months), 14 (6.9%) recipients experienced complications related to their enteric drainage. Complications during follow-up included early enteric anastomotic haemorrhage (five patients), non-anastomotic enteric bleeding (one patient), small bowel obstruction (four patients) and graft duodenal perforation (two within 6 weeks, five beyond 12 months). No recipient lost their graft as a direct result of complications related to enteric drainage. Patient and pancreas graft survival at 1 year was 99.0% and 94.0% and at 5 years 91.3% and 84.9%, respectively. We conclude that Roux-en-Y enteric drainage following pancreas transplantation is a safe and effective procedure and facilitates graft salvage in the event of graft duodenal perforation. © 2017 Steunstichting ESOT.

Development of a novel multi-layer MRE isolator for suppression of building vibrations under seismic events

NASA Astrophysics Data System (ADS)

Yang, Jian; Sun, Shuaishuai; Tian, Tongfei; Li, Weihua; Du, Haiping; Alici, Gursel; Nakano, Masami

2016-03-01

Protecting civil engineering structures from uncontrollable events such as earthquakes while maintaining their structural integrity and serviceability is very important; this paper describes the performance of a stiffness softening magnetorheological elastomer (MRE) isolator in a scaled three storey building. In order to construct a closed-loop system, a scaled three storey building was designed and built according to the scaling laws, and then four MRE isolator prototypes were fabricated and utilised to isolate the building from the motion induced by a scaled El Centro earthquake. Fuzzy logic was used to output the current signals to the isolators, based on the real-time responses of the building floors, and then a simulation was used to evaluate the feasibility of this closed loop control system before carrying out an experimental test. The simulation and experimental results showed that the stiffness softening MRE isolator controlled by fuzzy logic could suppress structural vibration well.

H. PYLORI INFECTION, ENDOSCOPIC, HISTOLOGICAL ASPECTS AND CELL PROLIFERATION IN THE GASTRIC MUCOSA OF PATIENTS SUBMITTED TO ROUX-EN-Y GASTRIC BYPASS WITH CONTENTION RING: a cross sectional endoscopic and immunohistochemical study.

PubMed

Nogueira, Thiago De Bortoli; Artigiani, Ricardo; Herani, Benedito; Waisberg, Jaques

2016-01-01

Morbid obesity treatment through vertical gastroplasty Roux-en-Y gastric bypass initially used a contention ring. However, this technique may create conditions to the development of potentially malign alterations in the gastric mucosa. Although effective and previously performed in large scale, this technique needs to be better evaluated in long-term studies regarding alterations caused in the gastric mucosa. To analyze the preoperative and postoperative endoscopic, histological and cell proliferation findings in the gastric antrum and body mucosa of patients submitted to the Roux-en-Y gastric bypass with a contention ring. We retrospectively evaluated all patients submitted to Roux-en-Y gastric bypass with a contention ring with more than 60 months of postoperative follow-up. We compared the preoperative (gastric antrum and body) and postoperative (gastric pouch) gastric mucosa endoscopic findings, cell proliferation index and H. pylori prevalence. We evaluated cell proliferation through Ki-67 antibody immunohistochemical expression. In the study period, 33 patients were operated with the Roux-en-Y gastric bypass using a contention ring. We found a chronic gastritis rate of 69.7% in the preoperative period (gastric antrum and body) and 84.8% in the postoperative (gastric pouch). H. pylori was present in 18.2% of patients in the preoperative period (gastric antrum and body) and in 57.5% in the postoperative (gastric pouch). Preoperative cell proliferation index was 18.1% in the gastric antrum and 16.2% in the gastric body, and 23.8% in the postoperative gastric pouch. The postoperative cell proliferation index in the gastric pouch was significantly higher (P=0.001) than in the preoperative gastric antrum and body. Higher cell proliferation index and chronic gastritis intensity were significantly associated to H. pylori presence (P=0.001 and P=0.02, respectively). After Roux-en-Y gastric bypass with contention ring, there was a higher chronic gastritis incidence and higher cell proliferation index in the gastric pouch than in the preoperative gastric antrum and body. Mucosa inflammation intensity and cell proliferation index in the postoperative gastric pouch were associated to H. pylori presence and were higher than those found in the preoperative gastric antrum and body mucosa.

CoolLoop® First: A First In Man Study To Test A Novel Circular Cryoablation System In Paroxysmal Atrial Fibrillation.

PubMed

Stuehlinger, Markus; Hoenig, Simon; Spuller, Karin; Koman, Christian; Stoeger, Markus; Poelzl, Gerhard; Ulmer, Hanno; Pachinger, Otmar; Steinwender, Clemens

2015-01-01

Pulmonary vein (PV) isolation is the mainstay of catheter treatment of paroxysmal atrial fibrillation (AF). The CoolLoop® cryoablation catheter (AFreeze® GmbH; Innsbruck, Austria) was developed to create wide and complete circular lesions around the PVs. In this study we evaluated feasibility and safety of this novel ablation system in humans. 10 patients (6M/4F; 57.6±7.6y) with paroxysmal AF were included in 2 referral centers. The CoolLoop® catheter was positioned at each PV antrum using a steerable transseptal sheath. Subsequently, 2-6 double-freezes over 5min were performed at each vein and PV-isolation was assessed thereafter using a circular mapping catheter. During cryoablation of the right PVs, pacing was used to monitor phrenic nerve function. The CoolLoop® catheter could be successfully positioned at each PV. A mean of 5.6±1.8 cryoablations were performed in the LSPV, 5.2±1.6 in the LIPV, 6.3±2.5 in the RSPV and 5.4±1.6 in the RIPV, respectively. Mean procedure time was 251±60min and mean fluoroscopy time was 44.0±13.2min. 6 / 10 LSPV, 6 / 10 LIPV, 5 / 10 RSPV and 6 / 10 RIPV could be isolated exclusively using the novel cryoablation system. One patient developed groin hematoma and a brief episode of ST-elevation due to air embolism was observed in another subject. No other clinical complications occurred during 3 months of follow up. PV-isolation for paroxysmal atrial fibrillation using the CoolLoop® catheter is feasible and appears safe. Clinical long term efficacy still needs to be evaluated and will be compared with established catheters used for AF ablation.

New totally intracorporeal reconstructive approach after robotic total gastrectomy: Technical details and short-term outcomes

PubMed Central

Parisi, Amilcare; Ricci, Francesco; Gemini, Alessandro; Trastulli, Stefano; Cirocchi, Roberto; Palazzini, Giorgio; D’Andrea, Vito; Desiderio, Jacopo

2017-01-01

AIM To show outcomes of our series of patients that underwent a total gastrectomy with a robotic approach and highlight the technical details of a proposed solution for the reconstruction phase. METHODS Data of gastrectomies performed from May 2014 to October 2016, were extracted and analyzed. Basic characteristics of patients, surgical and clinical outcomes were reported. The technique for reconstruction (Parisi Technique) consists on a loop of bowel shifted up antecolic to directly perform the esophago-enteric anastomosis followed by a second loop, measured up to 40 cm starting from the esojejunostomy, fixed to the biliary limb to create an enteroenteric anastomosis. The continuity between the two anastomoses is interrupted just firing a linear stapler, so obtaining the Roux-en-Y by avoiding to interrupt the mesentery. RESULTS Fifty-five patients were considered in the present analysis. Estimated blood loss was 126.55 ± 73 mL, no conversions to open surgery occurred, R0 resections were obtained in all cases. Hospital stay was 5 (3-17) d, no anastomotic leakage occurred. Overall, a fast functional recovery was shown with a median of 3 (3-6) d in starting a solid diet. CONCLUSION Robotic surgery and the adoption of a tailored reconstruction technique have increased the feasibility and safety of a minimally invasive approach for total gastrectomy. The present series of patients shows its implementation in a western center with satisfying short-term outcomes. PMID:28694670

Bayesian Action-Perception loop modeling: Application to trajectory generation and recognition using internal motor simulation

NASA Astrophysics Data System (ADS)

Gilet, Estelle; Diard, Julien; Palluel-Germain, Richard; Bessière, Pierre

2011-03-01

This paper is about modeling perception-action loops and, more precisely, the study of the influence of motor knowledge during perception tasks. We use the Bayesian Action-Perception (BAP) model, which deals with the sensorimotor loop involved in reading and writing cursive isolated letters and includes an internal simulation of movement loop. By using this probabilistic model we simulate letter recognition, both with and without internal motor simulation. Comparison of their performance yields an experimental prediction, which we set forth.

Current status of robotic bariatric surgery: a systematic review.

PubMed

Cirocchi, Roberto; Boselli, Carlo; Santoro, Alberto; Guarino, Salvatore; Covarelli, Piero; Renzi, Claudio; Listorti, Chiara; Trastulli, Stefano; Desiderio, Jacopo; Coratti, Andrea; Noya, Giuseppe; Redler, Adriano; Parisi, Amilcare

2013-11-07

Bariatric surgery is an effective treatment to obtain weight loss in severely obese patients. The feasibility and safety of bariatric robotic surgery is the topic of this review. A search was performed on PubMed, Cochrane Central Register of Controlled Trials, BioMed Central, and Web of Science. Twenty-two studies were included. Anastomotic leak rate was 8.51% in biliopancreatic diversion. 30-day reoperation rate was 1.14% in Roux-en-Y gastric bypass and 1.16% in sleeve gastrectomy. Major complication rate in Roux-en-Y gastric bypass resulted higher than in sleeve gastrectomy ( 4,26% vs. 1,2%). The mean hospital stay was longer in Roux-en-Y gastric bypass (range 2.6-7.4 days). The major limitation of our analysis is due to the small number and the low quality of the studies, the small sample size, heterogeneity of the enrolled patients and the lack of data from metabolic and bariatric outcomes. Despite the use of the robot, the majority of these cases are completed with stapled anastomosis. The assumption that robotic surgery is superior in complex cases is not supported by the available present evidence. The major strength of the robotic surgery is strongly facilitating some of the surgical steps (gastro-jejunostomy and jejunojejunostomy anastomosis in the robotic Roux-en-Y gastric bypass or the vertical gastric resection in the robotic sleeve gastrectomy).

Current status of robotic bariatric surgery: a systematic review

PubMed Central

2013-01-01

Background Bariatric surgery is an effective treatment to obtain weight loss in severely obese patients. The feasibility and safety of bariatric robotic surgery is the topic of this review. Methods A search was performed on PubMed, Cochrane Central Register of Controlled Trials, BioMed Central, and Web of Science. Results Twenty-two studies were included. Anastomotic leak rate was 8.51% in biliopancreatic diversion. 30-day reoperation rate was 1.14% in Roux-en-Y gastric bypass and 1.16% in sleeve gastrectomy. Major complication rate in Roux-en-Y gastric bypass resulted higher than in sleeve gastrectomy ( 4,26% vs. 1,2%). The mean hospital stay was longer in Roux-en-Y gastric bypass (range 2.6-7.4 days). Conclusions The major limitation of our analysis is due to the small number and the low quality of the studies, the small sample size, heterogeneity of the enrolled patients and the lack of data from metabolic and bariatric outcomes. Despite the use of the robot, the majority of these cases are completed with stapled anastomosis. The assumption that robotic surgery is superior in complex cases is not supported by the available present evidence. The major strength of the robotic surgery is strongly facilitating some of the surgical steps (gastro-jejunostomy and jejunojejunostomy anastomosis in the robotic Roux-en-Y gastric bypass or the vertical gastric resection in the robotic sleeve gastrectomy). PMID:24199869

Metabolic Changes After Roux-N-Y Bariatric Surgery In Hispanics.

PubMed

Hernández-Gil de Lamadrid, José; Nieves-Rivera, Juan J; Mora, Laura; Corretjer, Lisa; Altieri, Pablo I; Suárez, Albert; Banchs, Héctor L; Muñiz, Jesús; Soto, Marie Ivelisse; Escobales, Nelson; Crespo, María

2015-01-01

The objective was to describe the metabolic outcomes 12 months after bariatric surgery (Roux-N-Y) in morbidly obese Hispanic patients, and evaluate the correlation between weight loss and the observed changes. Medical records from a hundred-and-two Hispanic obese patients who underwent bariatric surgery were identified at the University of Puerto Rico (UPR) Hospital. The following variables were obtained before and 12 months after surgery: Body Mass Index (BMI), body weight, total cholesterol (TC), triglycerides, high density lipoprotein (HDL), low density lipoprotein (LDL), and fasting blood sugar (FBS). Ninety-seven percent of patients underwent Roux-N-Y surgery; 79.4% were females and 44% were diabetics. We observed statistically significant reductions (p < 0.05) 12 months after surgery in: BMI -14.3 (± 6.2) kg/m2, weight -86.1 (± 34.4) Ibs, TC -17.9 (± 32.4) mg/dL, triglycerides -28.7(± 40.6) mg/dL, LDL-15.4 (± 30.6) mg/dL, and FBS -11.3 (± 23.5) mg/dL. HDL, instead increased +5.22 (± 12.9) mg/dL (p < 0.0006). Gastric bypass surgery of the Roux-N-Y significantly improves the lipid profile and FBS levels in obese Hispanic patients. The poor correlation factor between weight loss and these variables suggests that other mechanisms, independent from weight loss, are responsible for these changes.

Repeated Duodenal Stump Perforation Using a Stapling Device Following Subtotal Gastrectomy With Roux-en-Y Reconstruction for Advanced Gastric Cancer: Lessons From a Rare Case.

PubMed

Furihata, Tadashi; Furihata, Makoto; Satoh, Naoki; Kosaka, Masato; Ishikawa, Kunibumi; Kubota, Keiichi

2015-04-01

Closure of the duodenal stump using a stapling device is commonly applied in Roux-en-Y reconstruction after gastrectomy. However, serious and possibly fatal duodenal stump perforation can develop in extremely rare cases. We describe a case of subtotal gastrectomy with Roux-en-Y reconstruction followed by repeated duodenal stump perforations. A 79-year-old man with a long history of diabetes and hypertension was admitted to our institution with epigastralgia and right hypochondralgia. Computed tomography and an upper gastrointestinal imaging series revealed remarkable wall thickening of the gastric antrum and corpus. Upper endoscopy also showed a giant ulcerative lesion in the same area. The lesion was confirmed by histology to be poorly differentiated adenocarcinoma. The patient underwent open subtotal gastrectomy with Roux-en-Y reconstruction. However, duodenal stump perforation occurred repeatedly on postoperative days 1, 3, and 19, which caused peritonitis. The patient was kept alive through duodenal stump repair, an additional resection using a stapling device, and repeated drainage treatments; but he suffered considerable morbidity due to these complications. We report a case of a life-threatening duodenal stump perforation after subtotal gastrectomy, highlighting lessons learned from the profile and clinical course. Abdominal surgeons should be aware of the possibility of this serious complication of duodenal stump perforation, and be able to perform immediate interventions, including life-saving reoperation.

EFFECT OF SIZE OF INTESTINAL DIVERSIONS IN OBESE PATIENTS WITH METABOLIC SYNDROME SUBMITTED TO GASTRIC BYPASS.

PubMed

Ramos, Rafael Jacques; Mottin, Cláudio Corá; Alves, Letícia Biscaino; Benzano, Daniela; Padoin, Alexandre Vontobel

There is no consensus on the ideal size of intestinal loops in gastric bypass of bariatric surgeries. To evaluate the metabolic outcome of patients submitted to gastric bypass with alimentary and biliopancreatic loops of different sizes. Was conducted a retrospective cohort study in diabetic obese patients (BMI≥35 kg/m2) with metabolic syndrome submitted to gastric bypass. The patients were divided into three groups according to the size of the intestinal loop: group 1, biliopancreatic limb 50 cm length and alimentary limb 100 cm length; group 2 , biliopancreatic limb 50 cm length and alimentary limb 150 cm length; and group 3, biliopancreatic limb 100 cm length and alimentary limb 150 cm length. The effect of gastric bypass with different sizes of intestinal loops in relation to the parameters that define metabolic syndrome was determined. Sixty-three patients were evaluated, and they had a mean age of 44.7±9.4 years. All were diabetics, with 62 (98.4%) being hypertensive and 51 (82.2%) dyslipidemic. The three groups were homogeneous in relation to the variables. In 24 months, there was a remission of systemic arterial hypertension in 65% of patients in group 1, 62.5% in group 2 and 68.4% in group 3. Remission of diabetes occurred in 85% of patients in group 1, 83% in group 2 and 84% in group 3. There was no statistical difference in %LEW between the groups, and waist measurements decreased in a homogeneous way in all groups. The size of loops also had no influence on the improvement in dyslipidemia. Variation in size of intestinal loops does not appear to influence improvement in metabolic syndrome in this group of patients. Não há consenso sobre o tamanho ideal das alças intestinais no bypass gástrico em Y-de-Roux em cirurgias bariátricas. Avaliar os desfechos metabólicos de pacientes submetidos ao bypass gástrico com alça intestinal alimentar e biliopancreática de tamanhos diferentes. Realizou-se coorte retrospectiva em pacientes obesos (IMC≥35 kg/m2) diabéticos com síndrome metabólica submetidos ao bypass gástrico em Y-de-Roux. Foram divididos em três grupos conforme a dimensão das alças intestinais: grupo 1, alça biliopancreática de 50 cm e alça alimentar de 100 cm; grupo 2, alça biliopancreática de 50 cm e alça alimentar de 150 cm e grupo 3, alça biliopancreática de 100 cm e alça alimentar de 150 cm. Foram avaliados os parâmetros que compõem a síndrome metabólica. Incluíram-se 63 pacientes, com média de idade de 44.7±9.4 anos. Todos eram diabéticos, 62 (98.4%) hipertensos e 51 (82.2%) dislipidêmicos. Os três grupos eram homogêneos em relação às variáveis estudadas. Em 24 meses houve remissão da hipertensão arterial sistêmica em 65% do grupo 1, 62.5% no grupo 2 e 68.4% no grupo 3. A remissão do diabete melito tipo 2 ocorreu em 85% dos pacientes do grupo 1, 83% no grupo 2, e 84% no grupo 3. Não houve diferença estatística na porcentagem de perda do excesso de peso entre os grupos e as medidas da cintura abdominal reduziram de forma homogênea em todos os grupos. A dimensão das alças também não influenciou na melhora da dislipidemia. A variação da dimensão das alças intestinais não influenciou na melhora da síndrome metabólica neste grupo de pacientes.

Roux-en-Y Esophagojejunostomy Ameliorates Renal Function Through Reduction of Renal Inflammatory and Fibrotic Markers in Diabetic Nephropathy.

PubMed

Wang, Cuifang; He, Bing; Piao, Dongxu; Han, Ping

2016-07-01

Roux-en-Y bariatric surgery has been shown to have a remarkable and sustainable improvement in type 2 diabetes. Recent clinical studies have shown that bariatric surgery can improve or halt the development of diabetic microvascular complications such as nephropathy. However, the exact underlying mechanisms of surgical procedures are unknown. Here, we have investigated the effects of Roux-en-Y esophagojejunostomy (RYEJ) on renal function and inflammation and fibrosis biomarkers for renal injury in type 2 diabetic rats. Sprague-Dawley rats with high fat diet and streptozotocin (STZ)-induced diabetes were randomly assigned into four groups: diabetic nephropathy (DN), DN treated with food restriction (DN-FR), DN treated with RYEJ surgery (DN-RYEJ), and DN-RYEJ sham (n = 6/group). Age-matched normal rats were assigned as control group. RYEJ and sham surgeries were performed. Hyperinsulinemic-euglycemic clamps with tracer infusion were completed to assess insulin sensitivity. Twenty-four hour urine albumin excretion rate (UAER) and glomerular filtration rate (GFR) were measured. The renal pathological injury was assessed by hematoxylin and eosin (HE) staining. Kidney messenger RNA (mRNA) and/or protein content/distribution of phospho-c-Jun NH2-terminal kinase (JNK), monocyte chemoattractant protein (MCP)-1, transforming growth factor (TGF)-β1, and mitogen-activated protein kinase phosphatase 5 (MKP5) were evaluated by real-time PCR and/or Western blotting/immunohistochemistry. Roux-en-Y esophagojejunostomy improved insulin sensitivity. RYEJ ameliorated renal function by improving UAER and GFR and attenuated glomerular hypertrophy after surgery. RYEJ also significantly downregulated the levels of JNK-mediated inflammatory response and upregulated the level of the anti-inflammatory mediator MKP5. Roux-en-Y esophagojejunostomy alleviates insulin resistance. RYEJ surgery ameliorated renal function and attenuated glomerular hypertrophy in a DN rat model. The considerable nephroprotective function may be mainly attributed to the reduced inflammatory and fibrotic biomarkers after RYEJ. The improvements in renal function and inflammation are not wholly dependent on the magnitude of weight loss.

Omentectomy added to Roux-en-Y gastric bypass surgery: a randomized, controlled trial.

PubMed

Dillard, Troy H; Purnell, Jonathan Q; Smith, Mark D; Raum, William; Hong, Dennis; Laut, Jamie; Patterson, Emma J

2013-01-01

Excess visceral adipose tissue predicts for incipient diabetes mellitus and cardiovascular disease. Human data are mixed regarding the benefits of selective visceral adipose tissue reduction. We investigated the effects of omentectomy added to laparoscopic Roux-en-Y gastric bypass on glucose homeostasis and lipids, inflammatory markers, and adipokines 90 days postoperatively in nondiabetic patients at the Legacy Good Samaritan Hospital and Oregon Health and Science University (Portland, OR). A single-blind, randomized study of laparoscopic Roux-en-Y gastric bypass plus omentectomy versus laparoscopic Roux-en-Y gastric bypass alone in 28 subjects (7 men and 21 women). The groups were matched at baseline for gender, age, and body mass index (BMI). The eligibility criteria included age ≥18 years, BMI ≥40 and <50 kg/m(2) without co-morbid conditions or BMI ≥35 and <50 kg/m(2) with co-morbid conditions. The primary outcome measures were changes in the fasting plasma glucose, insulin, and homostatic model assessment of insulin resistance. The secondary measures were BMI and the high-sensitivity C-reactive protein, tumor necrosis factor-α, interleukin, total and high-molecular-weight adiponectin, fibrinogen, and plasminogen activator inhibitor-1 levels. After surgery, the BMI decreased significantly in both groups and was not different at the follow-up point. Although many outcome parameters improved with weight loss in both groups postoperatively, only the omentectomy group experienced statistically significant decreases in fasting glucose (P < .05), total (P = .004) and very-low-density lipoprotein (P = .001) cholesterol, and an increase in the high-molecular-weight/total adiponectin ratio (P = .013). Omentectomy added to laparoscopic Roux-en-Y gastric bypass results in favorable changes in glucose homeostasis, lipid levels, and adipokine profile at 90 days postoperatively. These data support the hypothesis that selective ablation of visceral adipose tissue conveys metabolic benefits in nondiabetic humans. Copyright © 2013 American Society for Metabolic and Bariatric Surgery. Published by Elsevier Inc. All rights reserved.

Type 2 Diabetes Mellitus remission eighteen months after Roux-en-Y gastric bypass.

PubMed

Girundi, Marcelo Gomes

2016-01-01

to evaluate the effectiveness of Roux-en-Y gastric bypass in improving the glycemic profile of obese patients with type 2 Diabetes Mellitus (DM2) after 18 months of follow-up. four hundred sixty-eight pacients with DM2 and BMI ≥35 were submitted to Roux-en-Y gastric bypass, from 1998 to 2010. All patients were submitted to glycemic control analysis in the 3rd, 6th, 9th, 12th and 18th postoperative months. We considered: type 2 diabetic patients, the ones with fasting glucose ≥126mg/dl and HbA1C ≥6.5 in two dosages; high risk patients for diabetes, those who presented fasting glucose ≥ 100 to 125 mg/dl and HbA1C between 5.7%-6.4%; and normal patients, those presenting glucose <100mg/dl and HbA1C <5.7%. Such diagnostic criteria were based on the official position of Sociedade Brasileira de Diabetes, published in July, 2011. The remission of DM2 was seen in 410 (87.6%) out of 468 patients 18 months after the surgery, that being a meaningful difference, with p<0.001. Fourty-eight (10.3%) patients sustained criteria for the disease and ten (2.1%) continued at high risk for DM2. Roux-en-Y gastric bypass was effective in the promotion and maintaince of long-term glycemic control. There are evidences showing that the remission of DM2 is not only related to weight loss and that other enteroinsular axis mechanisms must be involved. avaliar a eficácia da gastroplastia com derivação em Y-de-Roux, em pacientes obesos e portadores de Diabetes Mellitus tipo 2 (DM2), na melhoria do perfil glicêmico após 18 meses de seguimento. foram submetidos à derivação gástrica em Y-de-Roux 468 pacientes com IMC ≥35 e portadores de DM2, no período de 1998 a 2010. Todos os pacientes tiveram a análise do controle glicêmico realizadas no terceiro, sexto, nono, 12o e 18o meses de pós-operatório. Os critérios diagnósticos de diabetes foram baseados no Posicionamento Oficial da Sociedade Brasileira de Diabetes, publicado em julho de 2011. observou-se a remissão do DM2 em 410 pacientes (87,6%) após 18 meses da cirurgia, sendo essa diferença significativa com p-valor <0,001. A doença se manteve inalterada em 48 pacientes (10,3%), e dez pacientes (2,1%) permaneceram com o risco aumentado para DM2. a gastroplastia com derivação em Y-de-Roux foi efetiva na promoção e manutenção do controle glicêmico em longo prazo.

Tunable Composite Metamaterials with Imbedded Coherently Controllable Atomic or Molecular Materials

DTIC Science & Technology

2010-10-07

using nanoporous alumina templates [G. Sauer, G. Brehm, and S. Schneider, “Highly ordered monocrystalline silver nanowire arrays” J. Appl...using stimulated Raman Scattering into the Stokes modes. Fig. 2: Left panel : A cross-sectional view of a typical unit cell of the plasmonic loop...Right panel : Magnetic response of an isolated loop inclusion illustrating the concentration of the magnetic field inside the loop at resonance, when

Morphological and functional changes after benzalkonium chloride treatment of the small intestinal Thiry-Vella loop in rats.

PubMed

Móricz, K; Gyetvai, B; Bárdos, G

1998-08-01

The aim of this work was to study the effects of benzalkonium chloride (BAC) treatment on the small intestine and its functioning in rats surgically prepared with Thiry-Vella intestinal loop. The loops were treated with either BAC, which ablated much of the myenteric plexus and extrinsic innervation, or with physiological saline (SAL). In vivo drinking experiments were performed to examine the effect on fluid intake and behavioral indices of distending the loop with a balloon. Spontaneous motility and its changes induced by acetylcholine (ACh) and histamine (His) were studied on isolated stripes in vitro. Finally, samples from the loops were examined histologically. Though reduction of the cell number was less than expected and no differences of the thickness of the muscular layer between the two groups was observed, BAC treatment altered the pattern of spontaneous activity and also the sensitivity to ACh and His in isolated stripes. In vivo distension of the SAL-treated loops reduced fluid intake and produced signs of aversivity; these effects were absent in the BAC-treated group. Our results show that despite the differences in the degree of ablation from those obtained by others, BAC treatment can be used to study the mechanisms underlying the effects of the enteral stimuli on the behavior.

Study on rejection characteristic of current loop to the base disturbance of optical communication system

NASA Astrophysics Data System (ADS)

Mao, Yao; Deng, Chao; Liu, Qiong; Cao, Zheng

2016-10-01

As laser has narrow transmitting beam and small divergence angle, the LOS (Line of Sight) stabilization of optical communication system is a primary precondition of laser communication links. Compound axis control is usually adopted in LOS stabilization of optical communication system, in which coarse tracking and fine tracking are included. Rejection against high frequency disturbance mainly depends on fine tracking LOS stabilization platform. Limited by different factors such as mechanical characteristic of the stabilization platform and bandwidth/noise of the sensor, the control bandwidth of LOS stabilization platform is restricted so that effective rejection of high frequency disturbance cannot be achieved as it mainly depends on the isolation characteristic of the platform itself. It is proposed by this paper that current loop may reject the effect of back-EMF. By adopting the method of electric control, high frequency isolation characteristic of the platform can be improved. The improvement effect is similar to increasing passive vibration reduction devices. Adopting the double closed loop control structure of velocity and current with the combining of the rejection effect of back-EMF caused by current loop is equivalent to reducing back-EMF coefficient, which can enhance the isolation ability of the LOS stabilization platform to high frequency disturbance.

Late intestinal obstruction due to an intestinal volvulus in a pregnant patient with a previous Roux-en-Y gastric bypass.

PubMed

Gazzalle, Anajara; Braun, Débora; Cavazzola, Leandro Totti; Wendt, Luiz Roberto; Navarini, Daniel; Fauri, Marcelo de Azevedo; Vitola, Santo Pascual

2010-12-01

This is a case of a 33 weeks pregnant woman, presented 2 years after laparoscopic Roux-en-Y gastric bypass, with abdominal pain for 2 days. A laparoscopic cholecystectomy was performed 1 day earlier in another hospital, without improving the pain. She presented at our hospital with acute abdominal pain and clinical signs of intestinal obstruction, undergoing an exploratory laparotomy that revealed a volvulus and necrosis of the jejunum from the gastroenteroanastomosis through the lateral enteroenterostomy, which was resected with the reconstruction of the Roux-en-Y limb performed at the same operation. Patient and neonate presented with improvement after surgery and the patient was discharged on postoperative day 15. Internal hernias after bariatric surgery have been reported as the cause of acute abdomen problems during pregnancy, which may progress to necrosis and perforation. The delay of surgical intervention could have brought a tragic outcome for mother and neonate.

Chronic biloma after right hepatectomy for stage IV hepatoblastoma managed with roux-en-Y biliary cystenterostomy

PubMed Central

Murphy, Andrew J.; Rauth, Thomas P.; Lovvorn, Harold N.

2012-01-01

We report the complex case of a 12-month-old female with stage IV hepatoblastoma accompanied by thrombosis and cavernous transformation of the portal vein. Following neoadjuvant chemotherapy, she underwent right hepatectomy, which was complicated by iatrogenic injury of her left hepatic duct, and subsequently developed a postoperative biloma and chronic biliocutaneous fistula. Concomitant with multiple percutaneous interventions to manage the biloma nonoperatively while the child completed her adjuvant chemotherapy, she progressed to develop chronic malnutrition, jaundice, and failure to thrive. Once therapy was completed and the child was deemed free of disease she underwent exploratory laparotomy with roux-en-Y biliary cyst-enterostomy for definitive management, resulting in resolution of her biliary fistula, jaundice, and marked improvement in her nutritional status. Roux-en-Y biliary cyst-enterostomy is a unique and efficacious management option in the highly selected patient population with chronic biliary leak refractory to minimally invasive management. PMID:23164033

Prototyping a compact system for active vibration isolation using piezoelectric sensors and actuators.

PubMed

Shen, Hui; Wang, Chun; Li, Liufeng; Chen, Lisheng

2013-05-01

Being small in size and weight, piezoelectric transducers hold unique positions in vibration sensing and control. Here, we explore the possibility of building a compact vibration isolation system using piezoelectric sensors and actuators. The mechanical resonances of a piezoelectric actuator around a few kHz are suppressed by an order of magnitude via electrical damping, which improves the high-frequency response. Working with a strain gauge located on the piezoelectric actuator, an auxiliary control loop eliminates the drift associated with a large servo gain at dc. Following this approach, we design, optimize, and experimentally verify the loop responses using frequency domain analysis. The vibration isolation between 1 Hz and 200 Hz is achieved and the attenuation peaks at 60 near vibration frequency of 20 Hz. Restrictions and potentials for extending the isolation to lower vibration frequencies are discussed.

Meta-analysis of Duct-to-duct versus Roux-en-Y biliary reconstruction following liver transplantation for primary sclerosing cholangitis.

PubMed

Pandanaboyana, Sanjay; Bell, Richard; Bartlett, Adam J; McCall, John; Hidalgo, Ernest

2015-04-01

This meta-analysis aimed to compare outcomes following bile duct reconstruction in patients with primary sclerosing cholangitis (PSC) undergoing liver transplantation depending on whether duct-to-duct or Roux-en-Y anastomosis was utilized. An electronic search was performed of the MEDLINE, EMBASE, PubMed databases using both subject headings (MeSH) and truncated word searches. Pooled risk ratios and mean difference were calculated using the fixed-effects and random-effects models for meta-analysis. Ten studies including 910 patients met the inclusion criteria. There was no difference in the overall incidence of biliary strictures between the two groups [odds ratio (OR) 1.06 (0.68, 1.66); (P = 0.80)]. The anastomotic stricture rate was similar, [OR 1.18 (0.56, 2.50); (P = 0.67)]. Ascending cholangitis was higher in the Roux-en-Y group [OR 2.91 (1.17, 7.23); (P = 0.02)]. Anastomotic bile leak rates, graft survival, PSC recurrence and number of patients diagnosed with cholangiocarcinoma following transplantation were comparable between both groups. Duct-to-duct and Roux-en-Y reconstruction had comparable outcomes. Both techniques are associated with similar incidence of biliary stricture. The bilioenteric reconstruction was associated with a higher risk of cholangitis. The incidence of de novo cholangiocarcinoma was similar in both groups. Duct-to-duct reconstruction should be considered when feasible in patients with PSC. © 2015 Steunstichting ESOT.

A CARE-compliant article: a case of retrograde intussusception with Uncut-Roux-en-Y anastomosis after radical total gastrectomy: Review of the literature.

PubMed

Zhou, Youxin; Wang, Fengfeng; Ji, Yong; Lv, Jian

2017-12-01

Postoperative intussusception is an unusual clinical entity and is rarely encountered as a complication following gastrectomy, especially radical total gastrectomy. A 74-year-old woman was admitted to our hospital with complaints of melena and hematemesis. And the endoscopic biopsy confirmed the poorly differentiated adenocarcinoma of the stomach. Radical total gastrectomy with Uncut Roux-en-Y reconstruction was performed. On the third postoperative day (POD3), the patient complained of paroxysmal pain around the umbilicus, accompanied by nausea and vomiting. Retrograde intussusceptions after radical total gastrectomy with Uncut Roux-en-Y reconstruction based on exploratory laparotomy. On POD4, the abdominal computed tomography (CT) showed small bowel dilatation and fluid accumulation in the upper abdominal cavity, as well as a small mass of soft tissue on the left side of the pelvis. Small bowel obstruction was considered, and exploratory laparotomy was performed. Retrograde intussusception started just below the jejunojejunal anastomosis with possible organic lesions, which was subsequently removed. The patient recovered well and was discharged 15 days after the second operation. This case report was written for 3 purposes: to increase awareness of this complication after radical total gastrectomy with Uncut-Roux-en-Y reconstruction; to emphasize early diagnosis through clinical manifestation, physical examination, and auxiliary examination with abdominal CT; and lastly, to emphasize that a reasonable surgical procedure should be performed immediately after diagnosis.

Duodenum-preserving resection and Roux-en-Y pancreatic jejunostomy in benign pancreatic head tumors.

PubMed

Yuan, Chun-Hui; Tao, Ming; Jia, Yi-Mu; Xiong, Jing-Wei; Zhang, Tong-Lin; Xiu, Dian-Rong

2014-11-28

This study was conducted to explore the feasibility of partial pancreatic head resection and Roux-en-Y pancreatic jejunostomy for the treatment of benign tumors of the pancreatic head (BTPH). From November 2006 to February 2009, four patients (three female and one male) with a mean age of 34.3 years (range: 21-48 years) underwent partial pancreatic head resection and Roux-en-Y pancreatic jejunostomy for the treatment of BTPH (diameters of 3.2-4.5 cm) using small incisions (5.1-7.2 cm). Preoperative symptoms include one case of repeated upper abdominal pain, one case of drowsiness and two cases with no obvious preoperative symptoms. All four surgeries were successfully performed. The mean operative time was 196.8 min (range 165-226 min), and average blood loss was 138.0 mL (range: 82-210 mL). The mean postoperative hospital stay was 7.5 d (range: 7-8 d). In one case, the main pancreatic duct was injured. Pathological examination confirmed that one patient suffered from mucinous cystadenoma, one exhibited insulinoma, and two patients had solid-pseudopapillary neoplasms. There were no deaths or complications observed during the perioperative period. All patients had no signs of recurrence of the BTPH within a follow-up period of 48-76 mo and had good quality of life without diabetes. Partial pancreatic head resection with Roux-en-Y pancreatic jejunostomy is feasible in selected patients with BTPH.

Laparoscopic Roux En Y Esophago-Jejunostomy for Chronic Leak/Fistula After Laparoscopic Sleeve Gastrectomy.

PubMed

Mahmoud, Maysoon; Maasher, Ahmed; Al Hadad, Mohamed; Salim, Elnazeer; Nimeri, Abdelrahman A

2016-03-01

Leak following laparoscopic sleeve gastrectomy (LSG) is one of the most serious and devastating complications. Endoscopic stents can treat most early LSG leaks, but is not as effective for chronic LSG leaks/fistulae. The surgical options to treat a chronic leak/fistula after LSG are laparoscopic Roux en Y esophago-jejunostomy (LRYEJ) or laparoscopic Roux en Y fistulo-jejunostomy. We reviewed our prospective database for all patients with leak after LSG treated with LRYEJ. We have described our algorithm for managing LSG previously. We prefer to optimize the nutritional status of patients with enteral rather than parenteral nutrition and drain all collections prior to LRYEJ. We have treated four patients utilizing our technique of LRYEJ. Initial endoscopic stent placement was attempted in all four patients (two failed to resolve (50 %) and two had distal stenosis at the incisura not amenable to endoscopic stenting). We utilized enteral feeding through either naso-jejunal (NJ) or jejunostomy tube feeding in 3/4 (75 %) of patients, and in one patient with stenosis, we could not introduce a NJ tube endoscopically due to tight stricture. This patient was placed on total parenteral nutrition (TPN) and went on to develop pulmonary embolism. None of the patient developed leak after LRYEJ. The only patient with stenosis (25 %) had antecolic LRYEJ. In contrast, all patients who had retrocolic LRYGB laparoscopically did not develop stenosis. Laparoscopic Roux en Y esophago-jejunostomy for chronic leak/fistula after is safe and effective. Preoperative enteral nutrition is important.

[FORMATION OF BILIODIGESTIVE AND INTERINTESTINAL ANASTOMOSES IN ENVIRONMENT OF BILIARY PERITONITIS, USING A HIGH FREQUENCY ELECTRIC WELDING IN EXPERIMENT].

PubMed

Nychytaylo, M Yu; Furmanov, Yu O; Gutsulyak, A I; Savytska, I M; Lopatkina, K G; Zagriychuk, M S; Goman, A V

2016-01-01

In experiment on 20 rabbits a diffuse biliary peritonitis was simulated, using intraabdominal injection of a laboratory culture of E. coli suspension and a medicinal bile. In 24 h on background of peritonitis on excluded loop of a small bowel in accordance to method of Roux, using a high frequency electric welding with the help of apparatus Patonmed EKB3-300 a one-layered everting cholecystoenteroanastomosis and enteroenteroanastomosis was formated. In a 6 mo postoperatively a connection line was not revealed from outside or from inside, the signs of stenosis were absent. In environment of a diffuse biliary peritonitis a welding technologies have permitted to form a hermetic and competent biliodigestive and interintestinal anastomoses, the processes of a welding suture regeneration postoperatively have a typical course. Using a high frequency-electric welding it is possible to perform a one-staged reconstructive interventions in environment of a pronounced inflammation of tissues due to subsequent precise conjunction of mucosal sheets of connected organs, preventing the anastomotic stricture formation.

The impact of Roux-en-Y gastric bypass surgery on normal metabolism in a porcine model

PubMed Central

Lindqvist, Andreas; Ekelund, Mikael; Garcia-Vaz, Eliana; Ståhlman, Marcus; Pierzynowski, Stefan; Gomez, Maria F.; Rehfeld, Jens F.; Groop, Leif; Hedenbro, Jan

2017-01-01

Background A growing body of literature on Roux-en-Y gastric bypass surgery (RYGB) has generated inconclusive results on the mechanism underlying the beneficial effects on weight loss and glycaemia, partially due to the problems of designing clinical studies with the appropriate controls. Moreover, RYGB is only performed in obese individuals, in whom metabolism is perturbed and not completely understood. Methods In an attempt to isolate the effects of RYGB and its effects on normal metabolism, we investigated the effect of RYGB in lean pigs, using sham-operated pair-fed pigs as controls. Two weeks post-surgery, pigs were subjected to an intravenous glucose tolerance test (IVGTT) and circulating metabolites, hormones and lipids measured. Bile acid composition was profiled after extraction from blood, faeces and the gallbladder. Results A similar weight development in both groups of pigs validated our experimental model. Despite similar changes in fasting insulin, RYGB-pigs had lower fasting glucose levels. During an IVGTT RYGB-pigs had higher insulin and lower glucose levels. VLDL and IDL were lower in RYGB- than in sham-pigs. RYGB-pigs had increased levels of most amino acids, including branched-chain amino acids, but these were more efficiently suppressed by glucose. Levels of bile acids in the gallbladder were higher, whereas plasma and faecal bile acid levels were lower in RYGB- than in sham-pigs. Conclusion In a lean model RYGB caused lower plasma lipid and bile acid levels, which were compensated for by increased plasma amino acids, suggesting a switch from lipid to protein metabolism during fasting in the immediate postoperative period. PMID:28257455

Outcomes of Endoscopic Retrograde Cholangiopancreatography (ERCP) and Sphincterotomy for Suspected Sphincter of Oddi Dysfunction (SOD) Post Roux-En-Y Gastric Bypass.

PubMed

Lim, Chin Hong; Jahansouz, Cyrus; Freeman, Martin L; Leslie, Daniel B; Ikramuddin, Sayeed; Amateau, Stuart K

2017-10-01

Sphincter of Oddi dysfunction (SOD) is thought to be a cause of chronic abdominal pain post Roux-en-Y gastric bypass, and current practice of performing endoscopic retrograde cholangiopancreatography (ERCP) with or without sphincterotomy is not supported by evidence. In addition to the complexity and risks of the procedure in patients with Roux-en-Y anatomy, the outcomes are uncertain and debatable. We performed a retrospective review and analysis of post-gastric bypass patients who had undergone ERCP with sphincterotomy to determine the effectiveness in patients with suspected SOD. Over a period of 5 years at the University of Minnesota, we retrospectively reviewed a prospectively collected database of a cohort of patients whom had a previous Roux-en-Y gastric bypass and whom had a subsequent ERCP for suspected SOD. Patients were categorized by modified Milwaukee classification, and outcomes were evaluated by patients' self-reporting of symptoms at follow-up. We identified 50 patients who underwent laparoscopic-assisted gastrostomy for endoscopic retrograde cholangiopancreatography post Roux-en-Y gastric bypass over the study period. Within this group, 35 patients (70%) were suspected to have SOD. Nine patients (25.7%) were classified as type I, 19 patients (54.3%) type II, and seven patients (20%) type III. Thirty-four patients (97.1%) had biliary sphincterotomy, and 17 patients (48.6%) had both biliary and pancreatic sphincterotomy. Fourteen (40%) had repeated ERCP. At median follow-up of 11.5 months, type I SOD had two responders (25%), type II had nine responders (52.9%), and type III had one responder (14.3%). A subgroup analysis did not show significant differences in improvement of symptoms between patients whom had single versus repeated ERCP or biliary sphincterotomy alone versus both biliary and pancreatic sphincterotomy. Three patients (9%) had post-ERCP pancreatitis. SOD in patients post Roux-en-Y gastric bypass is complex due to multiple confounding factors. Rome III and Milwaukee classification systems assist us in the diagnosis and treatment of sphincter dysfunction until we have a better way to predict treatment response post sphincterotomy. Current treatment is based on the type of disorder and anatomy of biliary ducts. Types I and II sphincter dysfunction particularly associated with dilated biliary duct on imaging have the best response to endoscopic sphincterotomy and therefore should be considered taking into account the risks and benefit. Repeated sphincterotomy and concurrent pancreatic sphincterotomy is generally not useful.

Numerical and experimental analysis of factors leading to suture dehiscence after Billroth II gastric resection.

PubMed

Cvetkovic, Aleksandar M; Milasinovic, Danko Z; Peulic, Aleksandar S; Mijailovic, Nikola V; Filipovic, Nenad D; Zdravkovic, Nebojsa D

2014-11-01

The main goal of this study was to numerically quantify risk of duodenal stump blowout after Billroth II (BII) gastric resection. Our hypothesis was that the geometry of the reconstructed tract after BII resection is one of the key factors that can lead to duodenal dehiscence. We used computational fluid dynamics (CFD) with finite element (FE) simulations of various models of BII reconstructed gastrointestinal (GI) tract, as well as non-perfused, ex vivo, porcine experimental models. As main geometrical parameters for FE postoperative models we have used duodenal stump length and inclination between gastric remnant and duodenal stump. Virtual gastric resection was performed on each of 3D FE models based on multislice Computer Tomography (CT) DICOM. According to our computer simulation the difference between maximal duodenal stump pressures for models with most and least preferable geometry of reconstructed GI tract is about 30%. We compared the resulting postoperative duodenal pressure from computer simulations with duodenal stump dehiscence pressure from the experiment. Pressure at duodenal stump after BII resection obtained by computer simulation is 4-5 times lower than the dehiscence pressure according to our experiment on isolated bowel segment. Our conclusion is that if the surgery is performed technically correct, geometry variations of the reconstructed GI tract by themselves are not sufficient to cause duodenal stump blowout. Pressure that develops in the duodenal stump after BII resection using omega loop, only in the conjunction with other risk factors can cause duodenal dehiscence. Increased duodenal pressure after BII resection is risk factor. Hence we recommend the routine use of Roux en Y anastomosis as a safer solution in terms of resulting intraluminal pressure. However, if the surgeon decides to perform BII reconstruction, results obtained with this methodology can be valuable. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

HIV-1 Clinical Isolates Resistant to CCR5 Antagonists Exhibit Delayed Entry Kinetics That Are Corrected in the Presence of Drug

PubMed Central

Putcharoen, Opass; Lee, Sun Hee; Henrich, Timothy J.; Hu, Zixin; Vanichanan, Jakapat; Coakley, Eoin; Greaves, Wayne; Gulick, Roy M.; Kuritzkes, Daniel R.

2012-01-01

HIV CCR5 antagonists select for env gene mutations that enable virus entry via drug-bound coreceptor. To investigate the mechanisms responsible for viral adaptation to drug-bound coreceptor-mediated entry, we studied viral isolates from three participants who developed CCR5 antagonist resistance during treatment with vicriviroc (VCV), an investigational small-molecule CCR5 antagonist. VCV-sensitive and -resistant viruses were isolated from one HIV subtype C- and two subtype B-infected participants; VCV-resistant isolates had mutations in the V3 loop of gp120 and were cross-resistant to TAK-779, an investigational antagonist, and maraviroc (MVC). All three resistant isolates contained a 306P mutation but had variable mutations elsewhere in the V3 stem. We used a virus-cell β-lactamase (BlaM) fusion assay to determine the entry kinetics of recombinant viruses that incorporated full-length VCV-sensitive and -resistant envelopes. VCV-resistant isolates exhibited delayed entry rates in the absence of drug, relative to pretherapy VCV-sensitive isolates. The addition of drug corrected these delays. These findings were generalizable across target cell types with a range of CD4 and CCR5 surface densities and were observed when either population-derived or clonal envelopes were used to construct recombinant viruses. V3 loop mutations alone were sufficient to restore virus entry in the presence of drug, and the accumulation of V3 mutations during VCV therapy led to progressively higher rates of viral entry. We propose that the restoration of pre-CCR5 antagonist therapy HIV entry kinetics drives the selection of V3 loop mutations and may represent a common mechanism that underlies the emergence of CCR5 antagonist resistance. PMID:22090117

Bowel obstruction rates in antecolic/antegastric versus retrocolic/retrogastric Roux limb gastric bypass: a meta-analysis.

PubMed

Al Harakeh, Ayman B; Kallies, Kara J; Borgert, Andrew J; Kothari, Shanu N

2016-01-01

Previous literature is varied with regard to rates of bowel obstruction after laparoscopic Roux-en-Y gastric bypass (LRYGB). Internal herniation through mesenteric defects is a common cause of bowel obstructions. There are advantages and disadvantages to routing the Roux limb via a retrocolic/retrogastric (RC/RG) versus an antecolic/antegastric (AC/AG) position. To review the literature comparing obstruction rates in RYGB using the antecolic versus retrocolic approach. Community-based integrated multispecialty health system with a teaching hospital serving 19 counties over a 3-state region. A literature search for articles published from 1994-2013 was completed. Articles were included if they reported an n>25, Roux limb route, obstruction rate by route, and follow-up duration. Statistical analysis included χ(2) test by patient number. The initial search identified 241 articles; 8 met inclusion criteria. There were 4805 patients in the AC/AG group, and 2238 in the RC/RG group. Follow-up ranged from 0 to 68 months. A linear stapled technique was reported in 4231 (88%) patients in the AC/AG group and 1541 (69%) of RC/RG group. Handsewn closure of mesenteric defects was reported in 2152 (45%) patients in the AC/AG group and 1012 (45%) patients in the RC/RG group. Bowel obstructions occurred in 68 (1.4%) patients in the AC/AG group and 117 (5.2%) patients in the RC/RG group (P<.001). Internal hernias were reported in 65 (1.3%) patients in the AC/AG group and 52 (2.3%) patients in the RC/RG group (P<.001). Two mortalities were reported in the AC/AG group. Increased rates of bowel obstruction and internal hernia were observed in the RC/RG group compared with the AC/AG group. A prospective, randomized trial would be necessary to definitively determine the impact of Roux limb position and routine closure of mesenteric defects on bowel obstruction rates after gastric bypass. Copyright © 2016 American Society for Bariatric Surgery. Published by Elsevier Inc. All rights reserved.

Factors affecting the operating time for complete cyst excision and Roux-en-Y hepaticojejunostomy in paediatric cases of congenital choledochal malformation: a retrospective case study in Southeast China

PubMed Central

Guo, Wan-liang; Zhan, Yang; Fang, Fang; Deng, Yan-bing; Zhao, Jun-gang

2018-01-01

Objective The aim of this study was to evaluate factors affecting the operating time for complete cyst excision and Roux-en-Y hepaticojejunostomy in paediatric cases of congenital choledochal malformation (CCM). Design A 3-year retrospective study was undertaken between January 2013 and December 2015 in four centres in China. Setting This involved a retrospective chart review of paediatric patients with CCM in four large hospitals in Southeast China. Participants Sixty-five paediatric patients with CCM were included in this study. We derived all available information on patient demographics, clinical characteristics, preoperative complications and surgical methods from the charts of all these patients. Interventions Univariate and multivariate logistic regression analyses were used to evaluate factors significantly affecting the operating time for complete cyst excision and Roux-en-Y hepaticojejunostomy in paediatric cases of CCM. Results Twenty-three of the 65 case surgeries were performed using laparoscopic technique, and 42 surgeries were performed by conventional open surgery. The median operating time was 215 min (range 120–430 min). The morphological subtype of CCM and the presence of cholecystitis or cholangitis were the only factors found to affect the operating time (p<0.05). Logistic regression analysis confirmed cholangitis as an independent risk factor. Conclusions The morphological subtype of CMM and the presence of cholecystitis or cholangitis are factors affecting the operating time for complete cyst excision and Roux-en-Y hepaticojejunostomy in paediatric cases of CCM, whereas cholangitis is an independent risk factor. PMID:29804066

Iatrogenic bile duct injury with loss of confluence.

PubMed

Mercado, Miguel-Angel; Vilatoba, Mario; Contreras, Alan; Leal-Leyte, Pilar; Cervantes-Alvarez, Eduardo; Arriola, Juan-Carlos; Gonzalez, Bruno-Adonai

2015-10-27

To describe our experience concerning the surgical treatment of Strasberg E-4 (Bismuth IV) bile duct injuries. In an 18-year period, among 603 patients referred to our hospital for surgical treatment of complex bile duct injuries, 53 presented involvement of the hilar confluence classified as Strasberg E4 injuries. Imagenological studies, mainly magnetic resonance imaging showed a loss of confluence. The files of these patients were analyzed and general data were recorded, including type of operation and postoperative outcome with emphasis on postoperative cholangitis, liver function test and quality of life. The mean time of follow-up was of 55.9 ± 52.9 mo (median = 38.5, minimum = 2, maximum = 181.2). All other patients with Strasberg A, B, C, D, E1, E2, E3, or E5 biliary injuries were excluded from this study. Patients were divided in three groups: G1 (n = 21): Construction of neoconfluence + Roux-en-Y hepatojejunostomy. G2 (n = 26): Roux-en-Y portoenterostomy. G3 (n = 6): Double (right and left) Roux-en-Y hepatojejunostomy. Cholangitis was recorded in two patients in group 1, in 14 patients in group 2, and in one patient in group 3. All of them required transhepatic instrumentation of the anastomosis and six patients needed live transplantation. Loss of confluence represents a surgical challenge. There are several treatment options at different stages. Roux-en-Y bilioenteric anastomosis (neoconfluence, double-barrel anastomosis, portoenterostomy) is the treatment of choice, and when it is technically possible, building of a neoconfluence has better outcomes. When liver cirrhosis is shown, liver transplantation is the best choice.

Prognostic value of intraventricular bleeding in spontaneous intraparenchymal cerebral hemorrhage of small volume: a prospective cohort study.

PubMed

Fortes Lima, Telmo Tiburcio; Prandini, Mirto Nelso; Gallo, Pasquale; Cavalheiro, Sérgio

2012-04-01

The literature is controversial on whether intraventricular bleeding has a negative impact on the prognosis of spontaneous intracerebral hemorrhage. Nevertheless, an association between intraventricular bleeding and spontaneous intracerebral hemorrhage volumes has been consistently reported. To evaluate the prognostic value of intraventricular bleeding in deep intraparenchymal hypertensive spontaneous hemorrhage with a bleeding volume <30 cm(3). Of the 320 patients initially evaluated, 33 met the inclusion criteria and were enrolled in this prospective study. The volume of intraparenchymal hemorrhage was calculated by brain computed tomography (CT) image analysis, and the volume of intraventricular bleeding was calculated by the LeRoux scale. Clinical data, including neurological complications, were collected daily during hospitalization. Neurological outcome was evaluated 30 days after the event by using the Glasgow outcome scale. Patients were assigned to 1 of 3 groups according to intraventricular bleeding: Control, no intraventricular bleeding; LR 1, intraventricular bleeding with LeRoux scale scores of 1 to 8; or LR 2, intraventricular bleeding with LeRoux scale scores >8. There were no significant differences among groups concerning age, mean blood pressure, and time from onset to brain CT scan. Patients with greater intraventricular bleeding presented lower initial Glasgow coma scale scores, increased ventricular index and width of temporal horns, increased number of clinical and neurological complications, and longer hospitalization. Furthermore, their relative risk for unfavorable clinical outcome was 1.9 (95% confidence interval 1.25-2.49). Intraventricular bleeding with a LeRoux scale score >8 appears to have a negative effect on deep spontaneous intraparenchymal cerebral hemorrhage of small volume.

Biliary bypass surgery - Analysis of indications & outcome of different procedures.

PubMed

Hussain Talpur, K Altaf; Mahmood Malik, Arshad; Iqbal Memon, Amir; Naeem Qureshi, Jawed; Khan Sangrasi, Ahmed; Laghari, Abdul Aziz

2013-05-01

This study reports the indications and outcome of various biliary bypass surgical procedures from a single centre over a period of 10 years. This is a prospective observational study conducted over a period of 10 years (January 2001-december 2010). A total of 1500 patients were included, who underwent pancreatico-biliary surgery due to common bile duct (CBD) stones, congenital anomalies of biliary tree, unoperable pancreatico-biliary malignancies, CBD strictures and cases who developed iatrogenic biliary injuries during cholecystectomy (both open & laproscopic) during this period of time. The patients who required biliary bypass surgery were further analysed for indications and outcome. Out of 1500 patients 83(5.53%) required biliary bypass surgical procedures. The CBD stones were observed as the most common indication (25.3%), followed by CBD injuries after open(10.84%) or laproscopic-cholecystectomy (14.46%), carcinoma head of pancreas (12.05%) and CBD obstruction(14.46%) either due to CBD strictures or unknown distal obstruction. Roux-en-Y-hepatico-jejunostomy (26.51%) was the most frequently performed procedure, followed by choledochoduodenostomy and Roux-en-Y choledocho-jejunostomy (i.e. 25.3% and 12.05% respectively). Roux-en-Y biliary bypass procedure was observed to be associated with better outcome in terms of rate of complications as well duration of hospital stay. Biliary bypass surgical procedures are the better options to restore the continuity of biliary system in patients with iatrogenic biliary tree injuries and un-operable pancreatico-biliary malignancy. Roux-en-Y biliary bypass procedure is safe and problem solving method in these cases.

Biliary bypass surgery – Analysis of indications & outcome of different procedures

PubMed Central

Hussain Talpur, K.Altaf; Mahmood Malik, Arshad; Iqbal Memon, Amir; Naeem Qureshi, Jawed; Khan Sangrasi, Ahmed; Laghari, Abdul Aziz

2013-01-01

Objectives: This study reports the indications and outcome of various biliary bypass surgical procedures from a single centre over a period of 10 years. Methods: This is a prospective observational study conducted over a period of 10 years (January 2001-december 2010). A total of 1500 patients were included, who underwent pancreatico-biliary surgery due to common bile duct (CBD) stones, congenital anomalies of biliary tree, unoperable pancreatico-biliary malignancies, CBD strictures and cases who developed iatrogenic biliary injuries during cholecystectomy (both open & laproscopic) during this period of time. The patients who required biliary bypass surgery were further analysed for indications and outcome. Results: Out of 1500 patients 83(5.53%) required biliary bypass surgical procedures. The CBD stones were observed as the most common indication (25.3%), followed by CBD injuries after open(10.84%) or laproscopic-cholecystectomy (14.46%), carcinoma head of pancreas (12.05%) and CBD obstruction(14.46%) either due to CBD strictures or unknown distal obstruction. Roux-en-Y-hepatico-jejunostomy (26.51%) was the most frequently performed procedure, followed by choledochoduodenostomy and Roux-en-Y choledocho-jejunostomy (i.e. 25.3% and 12.05% respectively). Roux-en-Y biliary bypass procedure was observed to be associated with better outcome in terms of rate of complications as well duration of hospital stay. Conclusion: Biliary bypass surgical procedures are the better options to restore the continuity of biliary system in patients with iatrogenic biliary tree injuries and un-operable pancreatico-biliary malignancy. Roux-en-Y biliary bypass procedure is safe and problem solving method in these cases. PMID:24353631

The gut hormone response following Roux-en-Y gastric bypass: cross-sectional and prospective study.

PubMed

Pournaras, Dimitrios J; Osborne, Alan; Hawkins, Simon C; Mahon, David; Ghatei, Mohammad A; Bloom, Steve R; Welbourn, Richard; le Roux, Carel W

2010-01-01

Bariatric surgery is the most effective treatment option for obesity, and gut hormones are implicated in the reduction of appetite and weight after Roux-en-Y gastric bypass. Although there is increasing interest in the gut hormone changes after gastric bypass, the long-term changes have not been fully elucidated. Thirty-four participants were studied cross-sectionally at four different time points, pre-operatively (n = 17) and 12 (n = 6), 18 (n = 5) and 24 months (n = 6) after laparoscopic Roux-en-Y gastric bypass. Another group of patients (n = 6) were studied prospectively (18-24 months). All participants were given a standard 400 kcal meal after a 12-h fast, and plasma levels of peptide YY (PYY) and glucagon-like peptide-1 (GLP-1) were correlated with changes in appetite over 3 h using visual analogue scores. The post-operative groups at 12, 18 and 24 months had a higher post-prandial PYY response compared to pre-operative (p < 0.05). This finding was confirmed in the prospective study at 18 and 24 months. There was a trend for increasing GLP-1 response at 18 and 24 months, but this did not reach statistical significance (p = 0.189) in the prospective study. Satiety was significantly reduced in the post-operative groups at 12, 18 and 24 months compared to pre-operative levels (p < 0.05). Roux-en-Y gastric bypass causes an enhanced gut hormone response and increased satiety following a meal. This response is sustained over a 24-month period and may partly explain why weight loss is maintained.

Bleeding duodenal ulcer after Roux-en-Y gastric bypass surgery: the value of laparoscopic gastroduodenoscopy.

PubMed

Issa, Hussain; Al-Saif, Osama; Al-Momen, Sami; Bseiso, Bahaa; Al-Salem, Ahmed

2010-01-01

Roux-en-Y gastric bypass is a common surgical procedure used to treat patients with morbid obesity. One of the rare, but potentially fatal complications of gastric bypass is upper gastrointestinal bleeding, which can pose diagnostic and therapeutic dilemmas. This report describes a 39-year-old male with morbid obesity who underwent a Roux-en-Y gastric bypass. Three months postoperatively, he sustained repeated and severe upper attacks of upper gastrointestinal bleeding. He received multiple blood transfusions, and had repeated upper and lower endoscopies with no diagnostic yield. Finally, he underwent laparoscopic endoscopy which revealed a bleeding duodenal ulcer. About 5 ml of saline with adrenaline was injected, followed by electrocoagulation to seal the overlying cleft and blood vessel. He was also treated with a course of a proton pump inhibitor and given treatment for H pylori eradication with no further attacks of bleeding. Taking in consideration the difficulties in accessing the bypassed stomach endoscopically, laparoscopic endoscopy is a feasible and valuable diagnostic and therapeutic procedure in patients who had gastric bypass.

Robotic assisted Roux-en-Y hepaticojejunostomy in a post-cholecystectomy type E2 bile duct injury

PubMed Central

Prasad, Arun; De, Sudipto; Mishra, Purak; Tiwari, Abhishek

2015-01-01

Roux-en-Y hepaticojejunostomy anastomosis is the treatment of choice for common hepatic duct injury type E2. It has been performed laparoscopically with the advancement of laparoscopic skill. Recently, a telemanipulative robotic surgical system was introduced, providing laparoscopic instruments with wrist-arm technology and 3-dimensional visualization of the operative field. We present a case of 36-year-old female patient who had undergone elective cholecystectomy 2 mo ago for gall stones and had a common bile duct injury during surgery. As the stricture was old and complete it could not be tackled endoscopically. We did a laparoscopic assisted adhesiolysis followed by robotic Roux-en-Y hepaticojejunostomy. No intraoperative complications or technical problems were encountered. Postoperative period was uneventful and she was discharged on the 4th postoperative day. At follow-up, she is doing well without evidence of jaundice or cholangitis. This is the first reported case of robotic hepaticojejunostomy following common bile duct injury. The hybrid technique gives the patient benefit of laparoscopic adhesiolysis and robotic suturing. PMID:25684934

Hybrid nodal loop metal: Unconventional magnetoresponse and material realization

NASA Astrophysics Data System (ADS)

Zhang, Xiaoming; Yu, Zhi-Ming; Lu, Yunhao; Sheng, Xian-Lei; Yang, Hui Ying; Yang, Shengyuan A.

2018-03-01

A nodal loop is formed by a band crossing along a one-dimensional closed manifold, with each point on the loop a linear nodal point in the transverse dimensions, and can be classified as type I or type II depending on the band dispersion. Here, we propose a class of nodal loops composed of both type-I and type-II points, which are hence termed as hybrid nodal loops. Based on first-principles calculations, we predict the realization of such loops in the existing electride material Ca2As . For a hybrid loop, the Fermi surface consists of coexisting electron and hole pockets that touch at isolated points for an extended range of Fermi energies, without the need for fine-tuning. This leads to unconventional magnetic responses, including the zero-field magnetic breakdown and the momentum-space Klein tunneling observable in the magnetic quantum oscillations, as well as the peculiar anisotropy in the cyclotron resonance.

UNRAVELLING THE COMPONENTS OF A MULTI-THERMAL CORONAL LOOP USING MAGNETOHYDRODYNAMIC SEISMOLOGY

DOE Office of Scientific and Technical Information (OSTI.GOV)

Prasad, S. Krishna; Jess, D. B.; Klimchuk, J. A.

Coronal loops, constituting the basic building blocks of the active Sun, serve as primary targets to help understand the mechanisms responsible for maintaining multi-million Kelvin temperatures in the solar and stellar coronae. Despite significant advances in observations and theory, our knowledge on the fundamental properties of these structures is limited. Here, we present unprecedented observations of accelerating slow magnetoacoustic waves along a coronal loop that show differential propagation speeds in two distinct temperature channels, revealing the multi-stranded and multithermal nature of the loop. Utilizing the observed speeds and employing nonlinear force-free magnetic field extrapolations, we derive the actual temperature variationmore » along the loop in both channels, and thus are able to resolve two individual components of the multithermal loop for the first time. The obtained positive temperature gradients indicate uniform heating along the loop, rather than isolated footpoint heating.« less

Development of a Microprocessor-Based Asynchronous Data Communications Line Tester.

DTIC Science & Technology

1981-12-01

either RS232 or 20 mA current loop 13. Current loop optically isolated 14. Current loop selectable for either active or pasive mode 15. Address...Executin Invoking the execution of the software is therefore a matter of power-up and reset. The software will wait for a response from the console (any key...SIO has two channels as previously mentioned. Addressing the SIO then is a matter of addressing these two channels. The port addrecses are user defined

The tethered bezoar as a delayed complication of laparoscopic Roux-en-Y gastric bypass: a case report.

PubMed

Pratt, Janey S A; Van Noord, Michael; Christison-Lagay, Emily

2007-05-01

Known complications of Roux-en-Y gastric bypass causing abdominal pain and obstructive symptoms include biliary colic, anastomotic ulcer, anastomotic stenosis, or internal hernia. This case report describes a new complication in a patient 15 months post-bypass: a bezoar at the gastrojejunal anastomosis, the nidus of which was a length of permanent suture material which had eroded through the gastric wall. We include endoscopic images of the bezoar, a review of the related gastric bypass literature, and describe the changes made in our practice as a result of this complication.

Laparoscopic Roux-en-Y gastric bypass in adolescents with severe obesity (AMOS): a prospective, 5-year, Swedish nationwide study.

PubMed

Olbers, Torsten; Beamish, Andrew J; Gronowitz, Eva; Flodmark, Carl-Erik; Dahlgren, Jovanna; Bruze, Gustaf; Ekbom, Kerstin; Friberg, Peter; Göthberg, Gunnar; Järvholm, Kajsa; Karlsson, Jan; Mårild, Staffan; Neovius, Martin; Peltonen, Markku; Marcus, Claude

2017-03-01

Severe obesity in adolescence is associated with reduced life expectancy and impaired quality of life. Long-term benefits of conservative treatments in adolescents are known to be modest, whereas short-term outcomes of adolescent bariatric surgery are promising. We aimed to compare 5-year outcomes of adolescent surgical patients after Roux-en-Y gastric bypass with those of conservatively treated adolescents and of adults undergoing Roux-en-Y gastric bypass, in the Adolescent Morbid Obesity Surgery (AMOS) study. We did a nationwide, prospective, non-randomised controlled study of adolescents (aged 13-18 years) with severe obesity undergoing Roux-en-Y gastric bypass at three specialised paediatric obesity treatment centres in Sweden. We compared clinical outcomes in adolescent surgical patients with those of matched adolescent controls undergoing conservative treatment and of adult controls undergoing Roux-en-Y gastric bypass. The primary outcome measure was change in BMI over 5 years. We used multilevel mixed-effect regression models to assess longitudinal changes. This trial is registered with ClinicalTrials.gov, number NCT00289705. Between April, 2006, and May, 2009, 100 adolescents were recruited to the study, of whom 81 underwent Roux-en-Y gastric bypass (mean age 16·5 years [SD 1·2], bodyweight 132·8 kg [22·1], and BMI 45·5 kg/m 2 [SD 6·1]). 80 matched adolescent controls and 81 matched adult controls were enrolled for comparison of outcomes. The change in bodyweight in adolescent surgical patients over 5 years was -36·8 kg (95% CI -40·9 to -32·8), resulting in a reduction in BMI of -13·1 kg/m 2 (95% CI -14·5 to -11·8), although weight loss less than 10% occurred in nine (11%). Mean BMI rose in adolescent controls (3·3 kg/m 2 , 95% CI 1·1-4·8) over the 5-year study period, whereas the BMI change in adult controls was similar to that in adolescent surgical patients (mean change -12·3 kg/m 2 , 95% CI -13·7 to -10·9). Comorbidities and cardiovascular risk factors in adolescent surgical patients showed improvement over 5 years and compared favourably with those in adolescent controls. 20 (25%) of 81 adolescent surgical patients underwent additional abdominal surgery for complications of surgery or rapid weight loss and 58 (72%) showed some type of nutritional deficiency; health-care consumption (hospital attendances and admissions) was higher in adolescent surgical patients compared with adolescent controls. 20 (25%) of 81 adolescent controls underwent bariatric surgery during the 5-year follow-up. Adolescents with severe obesity undergoing Roux-en-Y gastric bypass had substantial weight loss over 5 years, alongside improvements in comorbidities and risk factors. However, gastric bypass was associated with additional surgical interventions and nutritional deficiencies. Conventional non-surgical treatment was associated with weight gain and a quarter of patients had bariatric surgery within 5 years. Swedish Research Council; Swedish Governmental Agency for Innovation Systems; National Board of Health and Welfare; Swedish Heart and Lung Foundation; Swedish Childhood Diabetes Foundation; Swedish Order of Freemasons Children's Foundation; Stockholm County Council; Västra Götaland Region; Mrs Mary von Sydow Foundation; Stiftelsen Göteborgs Barnhus; Stiftelsen Allmänna Barnhuset; and the US National Institute of Diabetes, Digestive, and Kidney Diseases (National Institutes of Health). Copyright © 2017 Elsevier Ltd. All rights reserved.

[Pathogenic activity modulation of Escherichia coli TL+ toxin with an isolated protein of Giardia intestinalis and a synthetic peptide].

PubMed

Jiménez-Cardoso, E; Eligio-García, L; Jiménez-Cardoso, J M; Angeles-Anguiano, E; Tobilla-Mercado, J M; Castañeda, G

2001-01-01

It is know that a protein from Giardia intestinalis works as a substrate for V. cholerae and Escherichia coli. The toxic activity of both activates protein G form intestinal mucosa with a pathogenic activity results. In the present study, the pathogenic activity of subunit A of Vibrio cholerae toxin (ADP-ribosyltranferase) using isolated fragments from: Giardia intestinalis and a synthetic peptide were used as modulators in vivo. Adult Neo Zealand males rabbits with ileal loop were prepared and different mixtures of heat labile enterotoxin obtained from Escherichia coli H10407 and ARF protein isolated by electrofocusing from Giardia intestinalis Portland I were inoculated in the loops. The toxin activity was evaluated by luminal liquid secretion and cyclic AMP concentration in tissues (each loop). ADP ribosyltranferase activity was modulated, due to a decreased of luminal secretion and cAMP in tissues. Such results were seen when synthetic peptide and subunit A from Vibrio cholerae were used. The ADP ribosyltranferase activity of heat labile Escherichia coli and Vibrio cholerae toxins were modified by in vitro and in vivo interaction with ARF protein, which modified pathogenic effect over rabbits intestinal epithelium.

Periodic forcing of a shock train in a scramjet inlet-isolator at overspeed condition

NASA Astrophysics Data System (ADS)

Jiao, Xiaoliang; Chang, Juntao; Wang, Zhongqi; Yu, Daren

2018-02-01

Unsteady viscous numerical simulations are performed to explore the response of a shock train to downstream backpressure forcing in a scramjet inlet-isolator at the overspeed condition. A sinusoidal dynamic backpressure is applied at the exit of the isolator, thus leading a forced shock train oscillation. The results show that the shock train travels along a different path for the upstream and downstream movements. There is a clear hysteresis loop during the shock train oscillation. Under the low forcing frequency, the shock train travels in a clockwise loop. While it travels in a counter-clockwise loop under the high forcing frequency. Moreover, there is a lag between the shock train oscillation and the fluctuating backpressure. Especially for the high forcing frequency, the phase of the shock train oscillation is opposite to the fluctuating backpressure. The effects of the amplitude and frequency of the periodic fluctuating backpressure on the oscillation range of the shock train are also investigated. With the amplitude of the fluctuating backpressure increasing, the oscillation range of the shock train increases. With the frequency of the fluctuating backpressure increasing, the oscillation range of the shock train increases first and then decreases under high frequency.

Comparison of Virtual Nutri Plus® and Dietpro 5i® software systems for the assessment of nutrient intake before and after Roux-en-Y gastric bypass

PubMed Central

Marques da Silva, Mariane; Sala, Priscila Campos; Cardinelli, Camila Siqueira; Torrinhas, Raquel Suzana; Waitzberg, Dan Linetzky

2014-01-01

OBJECTIVES: The assessment of nutritional intake before and after bariatric surgery assists in identifying eating disorders, nutritional deficiencies and weight loss/maintenance. The 7-day record is the gold standard for such an assessment and is interpreted using specialized software. This study sought to compare the Virtual Nutri Plus® and Dietpro 5i® software systems in assessing nutrient intake in obese patients with type 2 diabetes mellitus who underwent a Roux-en-Y gastric bypass. METHODS: Nutritional intake was assessed in 10 obese women with type 2 diabetes mellitus before and 3 months after Roux-en-Y gastric bypass. The 7-day record was used to assess food intake and then, the Virtual Nutri Plus® and Dietpro 5i® software systems were used to calculate calorie, macronutrient and micronutrient intake based on validated food chemical composition databases. Clinicaltrials.gov: NCT01251016. RESULTS: During the preoperative period, deficits in the ingestion of total fiber and 15 out of 22 estimated micronutrients were observed when using the Virtual Nutri Plus®, compared to deficiencies in total fiber and 4 micronutrients when using the Dietpro 5i®. During the postoperative period, both the Virtual Nutri Plus® and Dietpro 5i® systems detected deficits in the ingestion of total fiber, carbohydrates and 19 micronutrients, but only the Virtual Nutri Plus® detected deficits in complex B vitamins (except B12) and minerals. CONCLUSION: Virtual Nutri Plus® was more sensitive than Dietpro 5i® for the identification of deficits in nutrient intake in obese, type 2 diabetes mellitus patients undergoing Roux-en-Y gastric bypass. PMID:25518027

Performance of the forward-view echoendoscope for pancreaticobiliary examination in patients with status post-upper gastrointestinal surgery

PubMed Central

Fusaroli, Pietro; Serrani, Marta; Lisotti, Andrea; D’Ercole, Maria Cristina; Ceroni, Liza; Caletti, Giancarlo

2015-01-01

Background and Objectives: Failures of endoscopic ultrasound (EUS) imaging of the head of the pancreas (HOP) and the common bile duct (CBD) have been reported in up to 50% of patients with status postsurgery (e.g., Billroth II and Roux-en-Y). This is attributable to inability to intubate the afferent limb or the duodenum. Recently, a forward-view (FV) echoendoscope has become available. The frontal endoscopic and ultrasound field of view theoretically allow easier manipulation throughout the gastrointestinal tract compared to the traditional echoendoscopes. The aim of our study was to evaluate the safety and performance of the FV echoendoscope for the investigation of the biliary tree and the pancreas, including fine-needle aspiration (FNA), in patients with surgically altered upper gastrointestinal anatomy. Patients and Methods: This was a retrospective evaluation of a prospectively maintained database. All EUS procedures were performed at our institution by one experienced endosonographer from March to September 2009 under conscious sedation. The FV echoendoscope was used for all procedures. Results: Twenty-five (25) out of 37 presented status post-Billroth II and 12 out of 37 with status post-Roux-en-Y surgery. Overall, HOP and CBD were adequately visualized in 28 out of 37 (75.7%). All the failures occurred in the Roux-en-Y patients. EUS-FNA was successfully performed in 16 patients. No adverse events were observed. Conclusions: The FV echoendoscope proved to be safe and effective in reaching the periampullary area in patients with previous Billroth II, allowing complete exploration of the HOP and the CBD and performance of EUS-FNA. However, FV EUS was unsuccessful in the majority of patients with Roux-en-Y, which still remains a challenging condition. PMID:26643703

Routine postoperative upper gastrointestinal series after Roux-en-Y gastric bypass: determination of whether it is necessary.

PubMed

Kolakowski, Stephen; Kirkland, Matt L; Schuricht, Alan L

2007-10-01

To evaluate the clinical utility of the routine use of postoperative barium swallow to diagnose postoperative complications in patients undergoing open or laparoscopic Roux-en-Y gastric bypass. A total of 417 consecutive patients undergoing Roux-en-Y gastric bypass at our institution between January 1, 2001, and December 31, 2002, were included. We performed 341 open procedures and 76 laparoscopic gastric bypasses. All patients received a limited postoperative fluoroscopic upper gastrointestinal series, except for the patients who exceeded the weight limitation of the radiologic equipment. Radiologic findings of anastomotic complications were anastomotic leak, delayed gastric emptying, gastric outlet obstruction, and gastrogastric fistula. We evaluated clinical signs and symptoms to obtain a list of criteria suggesting these complications. Patients were stratified into 2 groups: those with and those without radiographic anastomotic complications. Clinical and radiologic criteria were compared using univariate and multivariate logistic regression analysis. We noted 42 radiologic abnormalities during a routine postoperative barium swallow evaluation. Among our 417 patients, we documented 12 leaks (2.9%), 19 cases of delayed gastric emptying (4.6%), 4 gastric outlet obstructions (1.0%), and 7 gastrogastric fistulas (1.7%). The combination of fever, tachycardia, and tachypnea was the most specific indicator of a leak, at 0.99 (95% confidence limit, 0.99, 1.01). Nausea with vomiting was the most predictive indicator of delayed gastric emptying and gastric outlet obstruction, with a specificity of 0.99 (95% confidence limit, 0.98, 0.99) and 0.97 (95% confidence limit, 0.96, 0.99), respectively. Postoperative complications after Roux-en-Y gastric bypass surgery are predictable based on the patient's symptoms. The use of routine postoperative fluoroscopic upper gastrointestinal series is unnecessary in asymptomatic patients.

Iatrogenic bile duct injury with loss of confluence

PubMed Central

Mercado, Miguel-Angel; Vilatoba, Mario; Contreras, Alan; Leal-Leyte, Pilar; Cervantes-Alvarez, Eduardo; Arriola, Juan-Carlos; Gonzalez, Bruno-Adonai

2015-01-01

AIM: To describe our experience concerning the surgical treatment of Strasberg E-4 (Bismuth IV) bile duct injuries. METHODS: In an 18-year period, among 603 patients referred to our hospital for surgical treatment of complex bile duct injuries, 53 presented involvement of the hilar confluence classified as Strasberg E4 injuries. Imagenological studies, mainly magnetic resonance imaging showed a loss of confluence. The files of these patients were analyzed and general data were recorded, including type of operation and postoperative outcome with emphasis on postoperative cholangitis, liver function test and quality of life. The mean time of follow-up was of 55.9 ± 52.9 mo (median = 38.5, minimum = 2, maximum = 181.2). All other patients with Strasberg A, B, C, D, E1, E2, E3, or E5 biliary injuries were excluded from this study. RESULTS: Patients were divided in three groups: G1 (n = 21): Construction of neoconfluence + Roux-en-Y hepatojejunostomy. G2 (n = 26): Roux-en-Y portoenterostomy. G3 (n = 6): Double (right and left) Roux-en-Y hepatojejunostomy. Cholangitis was recorded in two patients in group 1, in 14 patients in group 2, and in one patient in group 3. All of them required transhepatic instrumentation of the anastomosis and six patients needed live transplantation. CONCLUSION: Loss of confluence represents a surgical challenge. There are several treatment options at different stages. Roux-en-Y bilioenteric anastomosis (neoconfluence, double-barrel anastomosis, portoenterostomy) is the treatment of choice, and when it is technically possible, building of a neoconfluence has better outcomes. When liver cirrhosis is shown, liver transplantation is the best choice. PMID:26527428

Hybrid laparoscopic-robotic management of type IVa choledochal cyst in the setting of prior Roux-en-Y gastric bypass: video case report and review of the literature.

PubMed

Chang, Julietta; Walsh, R Matthew; El-Hayek, Kevin

2015-06-01

Choledochal cysts are rare congenital disease of the biliary system. The recommended treatment of these lesions is surgical excision with biliary enteric reconstruction. In patients with normal anatomy, Roux-en-Y hepaticojejunostomy is preferred. However, different options in biliary reconstruction must be entertained in those with abnormal anatomy. Our patient is a 39-year-old female, who during workup for bariatric surgery two years prior to presentation, was found to have a 6 cm dilation of her common bile duct. She underwent a laparoscopic Roux-en-Y gastric bypass (LRYGB) in 2011 at an outside facility, with no planned intervention on her biliary tree. Ultimately, she developed right upper quadrant pain two years following her RYGB. Upon further workup including right upper quadrant ultrasound, an extrahepatic choledochal cyst was confirmed and she was referred to our institution for definitive care. The patient was taken to the operating room for resection of the choledochal cyst with hepatoenteric reconstruction. The dissection and resection of the cyst commenced laparoscopically. After performing a generous Kocher maneuver, we demonstrated that there was adequate mobilization of the duodenum to perform a tension free hepaticoduodenostomy, which was performed robotically. Her postoperative course was uneventful, and she was discharged home on postoperative day 3. At one month follow up, the patient was doing well with symptom resolution. Her final pathology revealed a choledochal cyst which was negative for dysplasia or carcinoma. Long-term follow up has been recommended with yearly alkaline phosphatase levels. Here we present a video of the technical considerations during a robot-assisted laparoscopic biliary reconstruction in a patient with a prior Roux-en-Y gastric bypass with a type IVA choledochal cyst.

Therapeutic peroral direct cholangioscopy using a single balloon enteroscope in patients with Roux-en-Y anastomosis (with videos).

PubMed

Yamauchi, Hiroshi; Kida, Mitsuhiro; Okuwaki, Kosuke; Miyazawa, Shiro; Matsumoto, Takaaki; Uehara, Kazuho; Miyata, Eiji; Hasegawa, Rikiya; Kaneko, Toru; Laopeamthong, Issaree; Lei, Yang; Iwai, Tomohisa; Imaizumi, Hiroshi; Koizumi, Wasaburo

2018-01-01

Peroral cholangioscopic lithotripsy is a useful procedure in patients with a normal gastrointestinal anatomy who have difficult-to-treat stones. We evaluated the usefulness of peroral direct cholangioscopy (PDCS) using single-balloon enteroscope (SBE) in patients with difficult-to-treat stones who had undergone Roux-en-Y reconstruction. Among 118 patients (169 sessions) who underwent SBE-assisted endoscopic retrograde cholangiopancreatography to treat biliary stones after Roux-en-Y reconstruction, patients in whom it was difficult to remove biliary stones via a transpapillary or transanastomotic approach and difficult to switch to ultra-slim endoscope, were retrospectively enrolled. The biliary insertion success rate, procedure success rate, procedure time, and procedural complications were assessed. The SBE was inserted into the bile-duct, first using a free-hand technique, second using a guide wire, and third using the large balloon anchoring and deflation (LBAD) technique. A total of 11 patients (14 sessions) were enrolled in this study. The biliary insertion success rate was 100%. Bile-duct insertion was performed using a free-hand technique in 4 sessions, a guide wire in 3 sessions (rendezvous technique, 2 sessions), and the LBAD technique in 7 sessions. The procedure success rate was 86% in first session, and 100% in second session. The median procedure time was 81 min (range 49-137). The median procedure time in the bile-duct was 21.5 min (range 6-60). Mild pancreatitis occurred as a complication in one patient. The median follow-up was 528 days (range 282-764). No patient had stone recurrence. PDCS using SBE is a useful procedure in patients with Roux-en-Y reconstruction. The LBAD technique is an useful technique of inserting SBE into the bile-duct.

A Retrospective Comparative Study of Primary Versus Revisional Roux-en-Y Gastric Bypass: Long-Term Results.

PubMed

Dardamanis, Dimitrios; Navez, Julie; Coubeau, Laurent; Navez, Benoit

2018-03-09

To compare the perioperative parameters and excess weight loss between patients operated by laporoscopic Roux-en-Y gastric bypass (LRYGB), as a primary operation or a revisional, for insufficient weight loss after vertical banded gastroplasty (VBG) or adjustable gastric banding (AGB). A retrospective analysis of all patients who underwent a LRYGB was performed for the period 2004-2011. Demographics, preoperative body mass index (BMI), co-morbidities, operation time, conversion rate, perioperative complications, hospitalization period, and % of excess BMI loss (%EBMIL) were investigated and compared between groups. Three hundred forty-two laparoscopic gastric bypass operations were performed, 245 were primary, and 97 revisional. Median follow-up was 30 months (range 0-108 months). Mean BMI (kg/m 2 ) before bypass was 45.2 for primary laparoscopic Roux-en-Y gastric bypass (pLRYGB) and 41.1 for revisional laparoscopic Roux-en-Y gastric bypass (rLRYGB). Median operative time and length of stay were longer for rLRYGB 157.5 versus 235 min (p < 0.001) and 6 versus 6.5 days (p = 0.05). Conversion to laparotomy was performed in eight patients, 0.4% of primary and 7.2% of revisional. Morbidity rate was 6.5% in pLRYGB versus 10% in rLRYGB (NS). There was one death in the primary group. Percentage of EBMIL was significantly lower in the revisional group at 12, 18, and 24 months of follow-up. Revisional and primary gastric bypass have no statistical differences in terms of morbidity. The % of excess BMI loss is lower after revisional gastric bypass during the first 2 years of follow-up. The trend of weight loss or weight regain was similar in both groups.

Randomized clinical trial comparing long-term quality of life for Billroth I versus Roux-en-Y reconstruction after distal gastrectomy for gastric cancer.

PubMed

Nakamura, M; Nakamori, M; Ojima, T; Iwahashi, M; Horiuchi, T; Kobayashi, Y; Yamade, N; Shimada, K; Oka, M; Yamaue, H

2016-03-01

Patients' quality of life (QoL) deteriorates remarkably after gastrectomy. Billroth I reconstruction following distal gastrectomy has the physiological advantage of allowing food to pass through the duodenum. It was hypothesized that Billroth I reconstruction would be superior to Roux-en-Y reconstruction in terms of long-term QoL after distal gastrectomy. This study compared two reconstructions in a multicentre prospective randomized clinical trial to identify the optimal reconstruction procedure. Between January 2009 and September 2010, patients who underwent gastrectomy for gastric cancer were randomized during surgery to Billroth I or Roux-en-Y reconstruction. The primary endpoint was assessment of QoL using the Functional Assessment of Cancer Therapy - Gastric (FACT-Ga) questionnaire 36 months after surgery. A total of 122 patients were enrolled in the study, 60 to Billroth I and 62 to Roux-en-Y reconstruction. There were no differences between the two groups in terms of postoperative complications or mortality, and no significant differences in FACT-Ga total score (P = 0·496). Symptom scales such as epigastric fullness (heaviness), diarrhoea and fatigue were significantly better in the Billroth I group at 36 months after gastrectomy (heaviness, P = 0·040; diarrhoea, P = 0·046; fatigue, P = 0·029). The rate of weight loss in the third year was lower for patients in the Billroth I group (P = 0·046). The choice of anastomotic reconstruction after distal gastrectomy resulted in no difference in long-term QoL in patients with gastric cancer. NCT01065688 (http://www.clinicaltrials.gov). © 2016 BJS Society Ltd Published by John Wiley & Sons Ltd.

Laparoscopic versus robotic-assisted Roux-en-Y gastric bypass: a retrospective, single-center study of early perioperative outcomes at a community hospital.

PubMed

Ahmad, Arif; Carleton, Jared D; Ahmad, Zoha F; Agarwala, Ashish

2016-09-01

The purpose of this study was to compare the operative and early perioperative outcomes of laparoscopic versus robotic-assisted Roux-en-Y gastric bypass procedures performed in a community hospital setting. The study was a chart review and analysis of the early perioperative outcomes of a total of 345 Roux-en-Y gastric bypass procedures performed by a single surgeon in a community hospital setting from January 2011 to October 2014. Of these, 173 procedures were performed laparoscopically and 172 were performed with robotic assistance utilizing the daVinci(®) surgical platform. Factors such as baseline patient characteristics, operative time, estimated blood loss (EBL), conversions to open procedure, complication rates, adverse events, length of stay (LOS), and return to the operating room for the two groups were retrospectively analyzed from a prospectively maintained database. Student's t test with unequal variances was used for statistical analysis, and a p value <0.05 was used for significance. There were no statistically significant differences in complication rates, EBL, or LOS between the two groups. There was a significant difference between the total operative times (135.30 ± 37.60 min for the laparoscopic procedure versus 154.84 ± 38.44 min for the robotic procedure, p < 0.05). There were no adverse intraoperative events, conversions to open procedures, leaks, strictures, returns to the operating room within 30 days, or mortalities in either group. Our study, which is the first of its kind to analyze the operative and early perioperative outcomes between laparoscopic and robotic-assisted Roux-en-Y gastric bypass procedures in the US community hospital setting, indicates that both are comparable in terms of safety, efficacy, and operative and early perioperative outcomes.

Identification of a high affinity nucleocapsid protein binding element within the Moloney murine leukemia virus Psi-RNA packaging signal: implications for genome recognition.

PubMed

D'Souza, V; Melamed, J; Habib, D; Pullen, K; Wallace, K; Summers, M F

2001-11-23

Murine leukemia virus (MLV) is currently the most widely used gene delivery system in gene therapy trials. The simple retrovirus packages two copies of its RNA genome by a mechanism that involves interactions between the nucleocapsid (NC) domain of a virally-encoded Gag polyprotein and a segment of the RNA genome located just upstream of the Gag initiation codon, known as the Psi-site. Previous studies indicated that the MLV Psi-site contains three stem loops (SLB-SLD), and that stem loops SLC and SLD play prominent roles in packaging. We have developed a method for the preparation and purification of large quantities of recombinant Moloney MLV NC protein, and have studied its interactions with a series of oligoribonucleotides that contain one or more of the Psi-RNA stem loops. At RNA concentrations above approximately 0.3 mM, isolated stem loop SLB forms a duplex and stem loops SL-C and SL-D form kissing complexes, as expected from previous studies. However, neither the monomeric nor the dimeric forms of these isolated stem loops binds NC with significant affinity. Longer constructs containing two stem loops (SL-BC and SL-CD) also exhibit low affinities for NC. However, NC binds with high affinity and stoichiometrically to both the monomeric and dimeric forms of an RNA construct that contains all three stem loops (SL-BCD; K(d)=132(+/-55) nM). Titration of SL-BCD with NC also shifts monomer-dimer equilibrium toward the dimer. Mutagenesis experiments demonstrate that the conserved GACG tetraloops of stem loops C and D do not influence the monomer-dimer equilibrium of SL-BCD, that the tetraloop of stem loop B does not participate directly in NC binding, and that the tetraloops of stem loops C and D probably also do not bind to NC. These surprising results differ considerably from those observed for HIV-1, where NC binds to individual stem loops with high affinity via interactions with exposed residues of the tetraloops. The present results indicate that MLV NC binds to a pocket or surface that only exists in the presence of all three stem loops. Copyright 2001 Academic Press.

Two-dimensional magnetohydrodynamic model of emerging magnetic flux in the solar atmosphere

NASA Technical Reports Server (NTRS)

Shibata, K.; Tajima, T.; Steinolfson, R. S.; Matsumoto, R.

1989-01-01

The nonlinear undular mode of the magnetic buoyancy instability in an isolated horizontal magnetic flux embedded in a two-temperature layered atmosphere (solar corona-chromosphere/photosphere) is investigated using a two-dimensional magnetohydrodynamic code. The results show that the flux sheet with beta of about 1 is initially located at the bottom of the photosphere, and that the gas slides down the expanding loop as the instability develops, with the evacuated loop rising as a result of enhanced magnetic buoyancy. The expansion of the magnetic loop in the nonlinear regime displays self-similar behavior. The rise velocity of the magnetic loop in the high chromosphere (10-15 km/s) and the velocity of downflow noted along the loop (30-50 km/s) are consistent with observed values for arch filament systems.

Towards isolation of the gene for X-linked retinitis pigmentosa (RP3)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dry, K.L.; Aldred, M.A.; Hardwick, L.J.

1994-09-01

Until recently the region of interest containing the gene for X-linked retinitis pigmentosa (RP3) was thought to lie between CYBB (Xp21.1) and the proximal end of the deletion in patient BB (JBBprox). This region was thought to span 100-150 kb. Here we present new mapping data to show that the distance between the 5{prime} (most proximal) end of CYBB and JBBprox is only 50 kb. Recently Roux et al. (1994) have described the isolation of a gene within this region but this showed no disease-associated changes. Further evidence from mapping the deletion in patient NF (who suffered from McLead`s syndromemore » and CGD but not RP) and from linkage analysis of our RP3 families with a new dinucleotide repeat suggests that the gene must extend proximally from JBBprox. In order to extend the region of search we have constructed a YAC contig spanning 800 kb to OTC. We are continuing our search for the RP3 gene using a variety of strategies including exon trapping and cDNA enrichment as well as direct screening of cDNA libraries with subclones from this region.« less

Matrix isolation infrared spectroscopic and theoretical study of 1,1,1-trifluoro-2-chloroethane (HCFC-133a)

NASA Astrophysics Data System (ADS)

Rodrigues, Gessenildo Pereira; Lucena, Juracy Régis; Ventura, Elizete; Andrade do Monte, Silmar; Reva, Igor; Fausto, Rui

2013-11-01

The molecular structure and infrared spectrum of the atmospheric pollutant 1,1,1-trifluoro-2-chloroethane (HCFC-133a; CF3CH2Cl) in the ground electronic state were characterized experimentally and theoretically. Excited state calculations (at the CASSCF, MR-CISD, and MR-CISD+Q levels) have also been performed in the range up to ˜9.8 eV. The theoretical calculations show the existence of one (staggered) conformer, which has been identified spectroscopically for the monomeric compound isolated in cryogenic (˜10 K) argon and xenon matrices. The observed infrared spectra of the matrix-isolated HCFC-133a were interpreted with the aid of MP2/aug-cc-pVTZ calculations and normal coordinate analysis, which allowed a detailed assignment of the observed spectra to be carried out, including identification of bands due to different isotopologues (35Cl and 37Cl containing molecules). The calculated energies of the several excited states along with the values of oscillator strengths and previous results obtained for CFCs and HCFCs suggest that the previously reported photolyses of the title compound at 147 and 123.6 nm [T. Ichimura, A. W. Kirk, and E. Tschuikow-Roux, J. Phys. Chem. 81, 1153 (1977)] are likely to be initiated in the n-4s and n-4p Rydberg states, respectively.

Adipocyte Size and Leptin Receptor Expression in Human Subcutaneous Adipose Tissue After Roux-en-Y Gastric Bypass.

PubMed

Tamez, Martha; Ramos-Barragan, Victoria; Mendoza-Lorenzo, Patricia; Arrieta-Joffe, Pablo; López-Martínez, Sergio; Rojano-Rodríguez, Martín E; Moreno-Portillo, Mucio; Frigolet, María E

2017-12-01

The molecular mechanisms implicated in pronounced weight loss and metabolic benefits after bariatric surgery are still unknown. Adipocyte phenotype and metabolism have not been entirely explored. However, some features of adipocyte function have been studied, such as adipocyte size and inflammation, which are both reduced after bariatric surgery. Adipocyte fat metabolism, which is partly regulated by leptin, is likely modified, since adipocyte area is decreased. Here, we show that leptin receptor expression is increased, while adipocyte size is decreased 8 months after Roux-en-Y gastric bypass. Thus, adipocyte function is possibly modified by improved leptin signaling after bariatric surgery.

Roux-en-Y gastric bypass augments the feeding responses evoked by gastrin releasing peptides

PubMed Central

Washington, Martha C.; Mhalhal, Thaer R.; Berger, Tanisha Johnson-Rouse Jose; Heath, John; Seeley, Randy; Sayegh, Ayman I.

2016-01-01

Background Roux-en-Y gastric bypass (RYGB) is the most effective method for the treatment of obesity and metabolic disease Roux-en-Y gastric bypass (RYGB) may reduce body weight by altering the feeding responses evoked by the short term satiety peptides. Materials and Methods Here, we measured meal size (MS, chow), intermeal interval (IMI) length and satiety ratio (SR, IMI/MS; food consumed per a unit of time) by the small and the large forms of gastrin releasing peptide (GRP) in rats, GRP-10 and GRP-29 (0, 0.1, 0.5 nmol/kg) infused in the celiac artery (CA, supplies stomach and upper duodenum) and the cranial mesenteric artery (CMA, supplies small and large intestine) in a RYGB rat model. Results GRP-10 reduced MS, prolonged the IMI and increased the SR only in the RYGB group, whereas GRP-29 evoked these responses by both routes and in both groups. Conclusion The RYGB procedure augments the feeding responses evoked by exogenous GRP, possibly by decreasing total food intake, increasing latency to the first meal, decreasing number of meals or altering the sites of action regulating MS and IMI length by the two peptides. PMID:27884350

Selection within organisms in the nineteenth century: Wilhelm Roux's complex legacy.

PubMed

Heams, Thomas

2012-09-01

Selectionism, or the extension of darwinian chance/selection dynamics beyond the individual level, has a long history in biological thought. It has generated important theories in immunology or neurology, and turns out to be a convincing framework to account for the intrinsic stochastic nature of core events in cellular biology. When looking back at the intellectual origins of selectionism, the essay by the German embryologist Wilhelm Roux, Der Kampf der Theile im Organismus (The Struggle of the Parts in the Organism - 1881) might be one, if not the earliest reference after the darwinian revolution. It describes the individual as a multilevel structure, where each level results from a 'darwinian' struggle of its parts (molecules, cells, tissues, organs). But Roux's theory, far from being a simple extension of natural selection, has complex and even conflictual relationships with darwinism. This essay is worth rediscovering as a subtle historical testimony of the evolutionary and developmental life sciences debates of its time. Moreover, some of its theses may also enrich some current debates among evolutionary biologists over levels of selection, and among cellular and molecular biologists over the status of determinism in biology today. Copyright © 2012 Elsevier Ltd. All rights reserved.

CLINICAL AND NUTRITIONAL ASPECTS IN OBESE WOMEN DURING THE FIRST YEAR AFTER ROUX-EN-Y GASTRIC BYPASS

PubMed Central

dos SANTOS, Tiago Dália; BURGOS, Maria Goretti Pessoa de Araújo; de LEMOS, Maria da Conceição Chaves; CABRAL, Poliana Coelho

2015-01-01

Background: Clinic care for morbid obesity is not very effective. Bariatric surgery is being considered the best way of intervention for this kind of obesity. Aim : Evaluate the clinical and nutritional evolution during the first year of obese women submitted to Roux-en-Y gastric bypass. Method : Retrospective series non-concurrent with 61 women. The variables were weight, BMI, weight loss percentage, loss of excessive weight percentage, waist circumference, hip circumference, lipid profile, daily use of supplements, practice of physical exercise, occurrence of sickness, nausea, constipation, diarrhea, asthenia, alopecia, dry skin, cramps and brittle nails. Results : They presented significant weight and IMC reduction as well as improvement in their lipid profile, in all consultations. After one year they presented 36,6% loss of the initial weight and 75% loss of excessive weight. The waist circumference also presented a considerable reduction on all the moments, decreasing from 122,1±13,4 cm to 94,1±10,6 cm. Regarding the intercurrences, the most frequent were alopecia, asthenia, dry skin and cramps. Conclusion : The Roux-en-Y gastric bypass was effective in promoting and maintenance weight loss during the period of the first postoperative year. PMID:26537276

Specialty Article: so You Think You Got a Bypass? A Case Series of Adventures in Bariatric Surgery.

PubMed

Wang, Eugene Y; Shope, Timothy R

2018-05-01

To raise awareness for surgeons encountering bariatric patients with anatomy that deviates from the standard Roux-en-Y gastric bypass (RYGB). This is a single-institution retrospective case series over 12 years (2003-2014) involving patients who believed they received RYGBs, but actually did not. Data was obtained reviewing physician encounters, imaging, and operative reports. There were six cases with confusing clinical pictures, found to have aberrant RYGB anatomy: (1) gastric bypass with jejuno-jejunostomy only without gastrojejunostomy, (2) distal partial vertical gastrectomy without expected prosthetic band, (3) inverse vertical banded gastroplasty, (4) non-divided gastric bypass with no gastrojejunostomy, (5) 20-cm Roux limb, with gastro-gastric fistula, and (6) 200-cm bilio-pancreatic limb similar to the traditional Scopinaro procedure. There are cases of "Roux-en-Y gastric bypasses" that have no resemblance to the named procedure at all. Adjunctive upper gastrointestinal studies and upper endoscopies help surgeons make diagnoses that are incongruent with the surgical history. It is important to keep in mind that there could be anatomic or surgical variations which were born out of necessity or based on other surgeons' creativities.

Improvements in the metabolic milieu following Roux-en-Y gastric bypass and the arrest of diabetic kidney disease.

PubMed

Docherty, Neil G; le Roux, Carel W

2014-09-01

Roux-en-Y gastric bypass (RYGB) is an efficacious intervention for morbid obesity and has a diabetes-remitting effect in patients with obesity and type 2 diabetes mellitus, which occurs prior to significant weight loss. Roux-en-Y gastric bypass is also associated with early and sustained reductions in the risk factor profile for the progression of diabetic complications. Attention is therefore now being placed on RYGB as a metabolic intervention with the capacity to yield therapeutic benefit in relation to the progression of diabetic complications, such as diabetic kidney disease. As alterations in gut anatomy following RYGB coincide with attendant shifts in downstream enteroendocrine signals with direct and indirect resolutionary effects on the kidney, the concept of an endocrine gut-kidney axis post-RYGB is growing. With the model of a gut-kidney axis in mind, this article summarizes emerging data on the effects of RYGB on risk factors for diabetic kidney disease (hyperglycaemia, dyslipidaemia and hypertension), highlighting a potential role for glucagon-like peptide 1 in risk factor reduction. © 2014 The Authors. Experimental Physiology © 2014 The Physiological Society.

Comparison of the effects of Roux-en-Y gastrojejunostomy and LRYGB with small stomach pouch on type 2 diabetes mellitus in patients with BMI<35 kg/m(2).

PubMed

Yi, Bo; Jiang, Juan; Zhu, Liyong; Li, Pengzhou; Im, Ibrahim; Zhu, Shaihong

2015-01-01

Based on distinct epidemiologic features of Chinese type 2 diabetes mellitus (T2DM) patients, who tend to have abdominal fat deposition, but with normal or mildly overweight epidemiologic features, our center initially had treated T2DM with body mass index (BMI)<35 kg/m² by performing laparoscopic Roux-en-Y gastrojejunostomy since 2008. This procedure is successful in treating abnormal glucose metabolism but not in improving abdominal visceral obesity. However, since 2011, laparoscopic Roux-Y gastric bypass (LRYGB) with a small stomach pouch has been performed at our center, with prominent resolution of abdominal visceral obesity and lower incidences of postoperative complications. The purpose of the present study was to formally compare these different procedures. From 2011 to 2013, 60 patients who met the NIH criteria were recruited and randomly assigned to undergo either laparoscopic Roux-en-Y gastrojejunostomy (n = 30) or LRYGB with a small stomach pouch (n = 30). All of the patients were followed for 12 months, and pre- and postoperative changes in BMI, waist circumference, fasting plasma glucose (FPG), postprandial plasma glucose (PBG), glycated hemoglobin (HbA1c), homoeostatic model assessment (HOMA-IR), the body fat rate and major complications were recorded. Both procedures were successful in reducing HbA1c, FPG, and PBG levels and HOMA-IR scores. However, LRYGB with a small stomach pouch resulted in a greater reduction in FPG, PBG, and HbA1c levels, and HOMA-IR scores compared with Roux-en-Y gastrojejunostomy. In addition, the reductions in BMI, body fat content, waist circumference, and the incidence of postoperative marginal ulcers in the small-stomach-pouch LRYGB were significant. Both procedures are effective treatments for T2DM patients with BMI<35 kg/m². However, the advantages of resolved abnormal glucose metabolism and abdominal visceral obesity and decreased incidences of surgical complications are more obvious for LRYGB with a small gastric pouch. Potentially, LRYGB with a small gastric pouch is more suitable for Chinese diabetic patients with BMI <35 kg/m². Copyright © 2015 American Society for Bariatric Surgery. All rights reserved.

Detailed molecular analyses of the hexon loop-1 and fibers of fowl aviadenoviruses reveal new insights into the antigenic relationship and confirm that specific genotypes are involved in field outbreaks of inclusion body hepatitis.

PubMed

Schachner, Anna; Marek, Ana; Grafl, Beatrice; Hess, Michael

2016-04-15

Forty-eight fowl aviadenoviruses (FAdVs) isolated from recent IBH outbreaks across Europe were investigated, by utilizing for the first time the two major adenoviral antigenic domains, hexon loop-1 and fiber, for compound molecular characterization of IBH-associated FAdVs. Successful target gene amplification, following virus isolation in cell culture or from FTA-card samples, demonstrated presence of FAdVs in all cases indicative for IBH. Based on hexon loop-1 analysis, 31 European field isolates exhibited highest nucleotide identity (>97.2%) to reference strains FAdV-2 or -11 representing FAdV-D, while 16 and one European isolates shared >96.0% nucleotide identity with FAdV-8a and -8b, or FAdV-7, the prototype strains representing FAdV-E. These results extend recognition of specific FAdV-D and FAdV-E affiliate genotypes as causative agents of IBH to the European continent. In all isolates, species specificity determined by fiber gene analysis correlated with hexon-based typing. A threshold of 72.0% intraspecies nucleotide identity between fibers from investigated prototype and field strains corresponded with demarcation criteria proposed for hexon, suggesting fiber-based analysis as a complementary tool for molecular FAdV typing. A limited number of strains exhibited inconsistencies between hexon and fiber subclustering, indicating potential constraints for single-gene based typing of those FAdVs. Within FAdV-D, field isolate fibers shared a high degree of nucleotide (>96.7%) and aa (>95.8%) identity, while FAdV-E field isolate fibers displayed greater nucleotide divergence of up to 22.6%, resulting in lower aa identities of >81.7%. Furthermore, comparison with FAdVs from IBH outbreaks outside Europe revealed close genetic relationship in the fiber, independent of the strains' geographic origin. Copyright © 2016 Elsevier B.V. All rights reserved.

Molecular differentiation and pathogenicity of Aviadenoviruses isolated during an outbreak of inclusion body hepatitis in South Africa.

PubMed

Joubert, Hilda W; Aitchison, Henry; Maartens, Louis H; Venter, Estelle H

2014-11-05

Fowl adenovirus (FAdV) is a member of the genus Aviadenovirus and causes a number of economically important poultry diseases. One of these diseases, inclusion body hepatitis (IBH), has a worldwide distribution and is characterised by acute mortality (5% - 20%) in production chickens. The disease was first described in the United States of America in 1963 and has also been reported in Canada, the United Kingdom, Australia, France and Ireland, but until now, not in South Africa. Adenoviruses isolated from the first outbreak of IBH in South Africa were able to reproduce the disease in chicken embryo livers. The aim of the present study was to characterise the viruses and determine the pathogenicity of the FAdV strains responsible for the first reported case of IBH in South Africa. Polymerase chain reaction (PCR) amplification of the L1 loop region of the fowl adenovirus hexon gene using degenerate primer pair hexon A/B was used to identify the viruses that were isolated. Restriction fragment length polymorphism (RFLP) of the amplification products was used for the differentiation of 14 isolates of fowl adenovirus. Sequencing of the PCR products followed by amino acid comparison and phylogenetic analysis using the L1 loop region of the hexon protein was done to determine the identity of the isolates. Amino acid sequences of the hexon genes of all the South African isolates were compared with those of reference strains representing FAdV species. Amino acid comparison of 12 South Africa field isolates to FAdV reference strains revealed a high sequence identity (> 93.33%) with reference strains T8-A and 764. Two of the isolates had high sequence identity (93.40%) with reference strains P7-A, C2B and SR48. Phylogenetic analysis of the L1 loop region of the hexon protein of all 14 South African isolates was consistent with their RFLP clusters. The mortality rates of embryos challenged with 106 egg infective doses (EID50) FAdV 2 were 80% - 87% and mortality rates for embryos challenged with 105.95 (EID50) FAdV 8b were 65% - 80%.

A chicken intestinal ligated loop model to study the virulence of Clostridium perfringens isolates recovered from antibiotic-free chicken flocks.

PubMed

Parent, Eric; Archambault, Marie; Charlebois, Audrey; Bernier-Lachance, Jocelyn; Boulianne, Martine

2017-04-01

Necrotic enteritis (NE) is a major problem in antibiotic-free (ABF) chicken flocks and specific strains of Clostridium perfringens are known to induce NE. The objective of this study was to develop a chicken intestinal ligated loop model in order to compare the virulence of various C. perfringens strains recovered from consecutive ABF flocks with and without NE. Intestinal loops were surgically prepared in 10 anaesthetized specific-pathogen-free chickens and alternately inoculated with C. perfringens isolates or brain heart infusion (BHI) media. Histological lesion scoring was performed for each loop. All strains from NE-affected flocks induced histological lesions compatible with NE whereas inoculation of loops with a commensal C. perfringens strain or BHI did not. Among inoculated strains, CP0994 (netB-positive and cpb2-positive) and CP-2003-1256 (netB-positive) demonstrated mean histological lesion scores significantly higher (P < 0.01) than those obtained with a commensal strain or BHI whereas strain CP1073 (netB-negative and cpb2-positive) induced intestinal lesions without significantly higher scores. In loops where villi were colonized by Gram-positive rods, significantly higher (P < 0.01) mean histological lesion scores were observed. This result supports the hypothesis that colonization of the intestinal mucosa by C. perfringens is a critical step in the pathogenesis of NE. Finally, we demonstrated the importance of controlling virulent C. perfringens strains in ABF chicken flocks as a highly virulent strain can be present in consecutive flocks with NE and possibly affect multiple flocks.

Roux-en-Y gastric bypass: effects on feeding behavior and underlying mechanisms

PubMed Central

Manning, Sean; Pucci, Andrea; Batterham, Rachel L.

2015-01-01

Bariatric surgery is the most effective treatment for severe obesity, producing marked sustained weight loss with associated reduced morbidity and mortality. Roux-en-Y gastric bypass surgery (RYGBP), the most commonly performed procedure, was initially viewed as a hybrid restrictive-malabsorptive procedure. However, over the last decade, it has become apparent that alternative physiologic mechanisms underlie its beneficial effects. RYGBP-induced altered feeding behavior, including reduced appetite and changes in taste/food preferences, is now recognized as a key driver of the sustained postoperative weight loss. The brain ultimately determines feeding behavior, and here we review the mechanisms by which RYGBP may affect central appetite-regulating pathways. PMID:25729850

Stem-Loop V of Varkud Satellite RNA Exhibits Characteristics of the Mg2+ Bound Structure in the Presence of Monovalent Ions

PubMed Central

2015-01-01

The Varkud Satellite RNA contains a self-cleaving ribozyme that has been shown to function independently of its surroundings. This 160 nucleotide ribozyme adopts a catalytically active tertiary structure that includes a kissing hairpin complex formed by stem-loop I and stem-loop V (SLV). The five-nucleotide 5′-rUGACU loop of the isolated SLV has been shown to adopt a Mg2+-dependent U-turn structure by solution NMR. This U-turn hairpin is examined here by molecular dynamics simulations in the presence of monovalent and divalent ions. Simulations confirm on an all-atom level the hypotheses for the role of the Mg2+ ions in stabilizing the loop, as well as the role of the solvent exposed U700 base. Additionally, these simulations suggest the Mg2+-free stem-loop adopts a wide range of structures, including energetically favorable structures similar to the Mg2+-bound loop structure. We propose this structure is a “gatekeeper” or precursor to Mg2+ binding when those ions are present. PMID:26328924

Probing the closed-loop model of mRNA translation in living cells

PubMed Central

Archer, Stuart K; Shirokikh, Nikolay E; Hallwirth, Claus V; Beilharz, Traude H; Preiss, Thomas

2015-01-01

The mRNA closed-loop, formed through interactions between the cap structure, poly(A) tail, eIF4E, eIF4G and PAB, features centrally in models of eukaryotic translation initiation, although direct support for its existence in vivo is not well established. Here, we investigated the closed-loop using a combination of mRNP isolation from rapidly cross-linked cells and high-throughput qPCR. Using the interaction between these factors and the opposing ends of mRNAs as a proxy for the closed-loop, we provide evidence that it is prevalent for eIF4E/4G-bound but unexpectedly sparse for PAB1-bound mRNAs, suggesting it primarily occurs during a distinct phase of polysome assembly. We observed mRNA-specific variation in the extent of closed-loop formation, consistent with a role for polysome topology in the control of gene expression. PMID:25826658

VERTICAL GASTRECTOMY AND GASTRIC BYPASS IN ROUX-EN-Y INDUCE POSTOPERATIVE GASTROESOPHAGEAL REFLUX DISEASE?

PubMed Central

NASSIF, Paulo Afonso Nunes; MALAFAIA, Osvaldo; RIBAS-FILHO, Jurandir Marcondes; CZECZKO, Nicolau Gregori; GARCIA, Rodrigo Ferreira; ARIEDE, Bruno Luiz

2014-01-01

Background The association between obesity and gastroesophageal reflux disease has a high incidence and may be present in half of obese patients with surgical indication. Bariatric operations can also induce reflux alone - differently from BMI factors - and its mechanisms are dependent on the type of procedure performed. Objective To perform a literature review comparing the two procedures currently most used for surgical treatment of obesity and analyze their relationship with the advent of pre-existing reflux disease or its appearance only in postoperative period. Method The literature was reviewed in virtual database Medline/PubMed, SciELO, Lilacs, Embase and Cochrane crossing the following MeSH descriptors: gastric bypass AND / OR anastomosis, Roux-en-Y AND / OR gastroesophageal reflux AND / OR gastroenterostomy AND / OR gastrectomy AND / OR obesity AND / OR bariatric surgery AND / OR postoperative period. A total of 135 relevant references were considered but only 30 were used in this article. Also was added the experience of the authors of this article in handling these techniques on this field. Conclusion The structural changes caused by surgical technique in vertical gastrectomy shows greater commitment of antireflux mechanisms predisposing the induction of GERD postoperatively compared to the surgical technique performed in the gastrointestinal Bypass Roux-en-Y. PMID:25409970

Treatment of severe peptic esophageal stricture with Roux-en-Y partial gastrectomy, vagotomy, and endoscopic dilation. A follow-up study.

PubMed

Salo, J A; Ala-Kulju, K V; Heikkinen, L O; Kivilaakso, E O

1991-04-01

Eleven patients with dysphagia caused by severe esophageal stricture (length 2 to 10 cm) resulting from reflux esophagitis were treated with fibroendoscopic dilation (Eder-Puestow) and Roux-en-Y partial gastrectomy with vagotomy during 10 years (1979 to 1988). There was no operative mortality, but complications developed in three patients: One patient had a mediastinal abscess demanding thoracotomy as a result of esophageal perforation after dilatation; one had postoperative pneumonia; and one patient had ileus. After a mean follow-up of 4 years (range 1 to 10 years) esophagitis healed in all cases, as judged by endoscopy. Eight patients were asymptomatic, but three had slight transient dysphagia. Postoperatively one to eight dilations (average three to four) were needed to relieve dysphagia in the first postoperative year, but later the stricture healed in every case. Postoperative pH measurement was performed in six latest patients and showed complete absence of reflux in all cases. It is concluded that Roux-en-Y partial gastrectomy with vagotomy and endoscopic dilation is an effective, simple, and safe procedure in the management of severe peptic esophageal (acid or alkaline esophagitis) stricture. However, occasional postoperative dilations at the outpatient clinic are often needed in severe cases in the first postoperative year.

Double plication for spring-mediated intestinal lengthening of a defunctionalized Roux limb.

PubMed

Dubrovsky, Genia; Huynh, Nhan; Thomas, Anne-Laure; Shekherdimian, Shant; Dunn, James C Y

2017-12-26

Spring-mediated distraction enterogenesis has been shown to increase the length of an intestinal segment. The goal of this study is to use suture plication to confine a spring within an intestinal segment while maintaining luminal patency to the rest of the intestine. Juvenile mini-Yucatan pigs underwent placement of nitinol springs within a defunctionalized Roux limb of jejunum. A 20 French catheter was passed temporarily, and sutures were used to plicate the intestinal wall around the catheter at both ends of the encapsulated spring. Uncompressed springs placed in plicated segments and springs placed in nonplicated segments served as controls. The intestine was examined approximately 3 weeks after spring placement. In the absence of plication, springs passed through the intestine within a week. Double plication allowed the spring to stay within the Roux limb for 3 weeks. Compared to uncompressed springs that showed no change in the length of plicated segments, compressed springs caused a significant 1.7-fold increase in the length of plicated segments. Intestinal plication is an effective method to confine endoluminal springs. The confined springs could lengthen intestine that maintains luminal patency. This approach may be useful to lengthen intestine in patients with short bowel syndrome. Level I Experimental Study. Copyright © 2018. Published by Elsevier Inc.

Hepatic artery reconstruction with the jejunal artery of the Roux-en-Y limb in pediatric living donor liver re-transplantation.

PubMed

Wakiya, T; Sanada, Y; Mizuta, K; Umehara, M; Urahashi, T; Egami, S; Hishikawa, S; Nakata, M; Hakamada, K; Yasuda, Y; Kawarasaki, H

2012-05-01

When re-anastomosis and re-transplantation becomes necessary after LDLT, arterial reconstruction can be extremely difficult because of severe inflammation and lack of an adequate artery for reconstruction. Frequently, the recipient's HA is not in good condition, necessitating an alternative to the HA. In such cases, the recipient's splenic artery, right gastroepiploic artery or another vessel can be safely used for arterial reconstruction. There have, however, been few reports on using the jejunal artery. Herein, we report our experience with arterial reconstruction using the jejunal artery of the Roux-en-Y limb as an alternative to the HA. A three-yr-old girl who had developed graft failure due to early HA thrombosis after LDLT required re-transplantation. At re-transplantation, an adequate artery for reconstruction was lacking. We reconstructed the artery by using the jejunal artery of the Roux-en-Y limb, as we judged it to be the most appropriate alternative. After surgery, stent was deployed because hepatic blood flow had reduced due to kinking of the anastomosed site, and a favorable outcome was obtained. In conclusion, when an alternative to the HA is required, using the jejunal artery is a feasible alternative. © 2010 John Wiley & Sons A/S.

Predicted stem-loop structures and variation in nucleotide sequence of 3' noncoding regions among animal calicivirus genomes.

PubMed

Seal, B S; Neill, J D; Ridpath, J F

1994-07-01

Caliciviruses are nonenveloped with a polyadenylated genome of approximately 7.6 kb and a single capsid protein. The "RNA Fold" computer program was used to analyze 3'-terminal noncoding sequences of five feline calicivirus (FCV), rabbit hemorrhagic disease virus (RHDV), and two San Miguel sea lion virus (SMSV) isolates. The FCV 3'-terminal sequences are 40-46 nucleotides in length and 72-91% similar. The FCV sequences were predicted to contain two possible duplex structures and one stem-loop structure with free energies of -2.1 to -18.2 kcal/mole. The RHDV genomic 3'-terminal RNA sequences are 54 nucleotides in length and share 49% sequence similarity to homologous regions of the FCV genome. The RHDV sequence was predicted to form two duplex structures in the 3'-terminal noncoding region with a single stem-loop structure, resembling that of FCV. In contrast, the SMSV 1 and 4 genomic 3'-terminal noncoding sequences were 185 and 182 nucleotides in length, respectively. Ten possible duplex structures were predicted with an average structural free energy of -35 kcal/mole. Sequence similarity between the two SMSV isolates was 75%. Furthermore, extensive cloverleaflike structures are predicted in the 3' noncoding region of the SMSV genome, in contrast to the predicted single stem-loop structures of FCV or RHDV.

Better long-term outcomes with hilar ductoplasty and a side-to-side Roux-en-Y hepaticojejunostomy.

PubMed

Xia, Hong-Tian; Liu, Yang; Yang, Tao; Liang, Bin; Wang, Jing; Dong, Jia-Hong

2017-07-01

Whether a wide hilar hepaticojejunostomy after bile duct cyst (BDC) excision can prevent the development of postoperative complications remains an unanswered question. We compared our outcomes after a minimum of 2-y follow-up in patients with Todani type Ia choledochal cyst treated with hilar ductoplasty followed by a side-to-side Roux-en-Y hepaticojejunostomy (ductoplasty group) or radical cyst resection with an end-to-side Roux-en-Y hepaticojejunostomy (conventional group). We retrospectively reviewed the records of patients with Todani type Ia choledochal cyst who received radical cyst excision from January 1997 to December 2012, and we compared the groups' postoperative complications and surgical outcomes. The groups' baseline demographics were similar, except for age. The gender distribution and preoperative presenting symptoms were comparable in the ductoplasty (n = 72) and conventional (n = 53) groups (all P > 0.05). Average age was 37.0 y for the ductoplasty group and 41.8 y for the conventional group (P = 0.024). The short-term complication rate of the groups was not significantly different (conventional group, 13.2% [7/53]; ductoplasty group, 8.3% [6/72]; all P > 0.05). A significant between-group difference was found in the long-term complication rate of biliary-enteric anastomotic strictures (9.4% in the conventional group and 0% in the ductoplasty group, P = 0.012). The rates of satisfactory surgical outcomes were 91.1% and 77.1% in the ductoplasty and conventional groups, respectively (P = 0.036). The application of hilar ductoplasty with a side-to-side Roux-en-Y hepaticojejunostomy as the primary surgery for bile duct cyst excision significantly reduced the postoperative complication of biliary-enteric anastomotic stricture and greatly improved our patients' prognosis with regard to biliary function. Copyright © 2017 Elsevier Inc. All rights reserved.

Down-Regulation of Renal Gluconeogenesis in Type II Diabetic Rats Following Roux-en-Y Gastric Bypass Surgery: A Potential Mechanism in Hypoglycemic Effect

PubMed Central

Wen, Yi; Lin, Ning; Yan, Hong-Tao; Luo, Hao; Chen, Guang-Yu; Cui, Jian-Feng; Shi, Li; Chen, Tao; Wang, Tao; Tang, Li-Jun

2015-01-01

Objective This study was initiated to evaluate the effects of Roux-en-Y gastric bypass surgery on renal gluconeogenesis in type 2 diabetic rats and its relationship with hormonal parameters. Methods Diabetic rats were induced by intraperitoneal injection of streptozotocin (STZ; 35 mg/kg) combined with a high-fat diet. They were then randomly divided into three groups: diabetes model group (DM group, n = 8), sham Roux-en-Y gastric bypass group (SRYGB group, n = 8), and Roux-en-Y gastric bypass group (RYGB group, n = 14). Another 8 normal rats comprised the normal control group (NC group, n = 8). Body weight, glucose, serum lipid, insulin, glucagon-like peptide-1 (GLP-1), leptin, and adiponectin were measured pre- and postoperatively. Glucose-6-phosphatase (G6Pase), phosphoenolpyruvate carboxykinase (PEPCK), insulin receptor-α (IR-α), insulin receptor-β (IR-β), and glycogen synthase kinase 3 beta (Gsk3b) were measured in renal cortex by using RT-PCR and Western immune-blot analyses on the 4th week after operation. Results Following RYGB surgery, surgery-treated rats showed significantly improved oral glucose tolerance, dyslipidemia and insulin resistance as well as increased post-gavage insulin levels and serum circulating levels of GLP-1 and adiponectin. RT-PCR and Western immune-blot analyses showed PEPCK and G6Pase protein and mRNA to be significantly decreased in the renal cortex in the RYGB group (p < 0.05 vs. DM or SRYGB group); in addition, IR-α and Gsk3b phosphorylation levels increased in the RYGB group (p < 0.05 vs. DM or SRYGB group). Conclusion Down-regulation of renal gluconeogenic enzymes might be a potential mechanism in hypoglycemia. An improved insulin signal pathway in the renal cortex and increased circulating adiponectin concentrations may contribute to the decline of renal gluconeogenesis following RYGB surgery. PMID:25832593

Customization of biliopancreatic limb length to modulate and sustain antidiabetic effect of gastric bypass surgery.

PubMed

Pal, A; Rhoads, D B; Tavakkoli, A

2018-02-01

Although Roux-en-Y Gastric Bypass (RYGB) remains the most effective treatment for obesity and type 2 diabetes (T2D), many patients fail to achieve remission, or relapse. Increasing intestinal limb lengths of RYGB may improve outcomes, but the mechanistic basis for this remains unclear. We hypothesize biliopancreatic (BP) limb length modulates the antidiabetic effect of RYGB. Rats underwent RYGB with a 20-cm (RYGB-20cm) or 40-cm (RYGB-40cm) BP limb and were compared with control animals. After 2 and 4 wk, portal and systemic blood was sampled during intestinal glucose infusion. Portosystemic gradient was used to calculate intestinal glucose utilization (G util ), absorption (G absorp ), and hormone secretion. Intestinal morphology and gene expression were assessed. At 2 wk, G absorp progressively decreased with increasing BP limb length; this pattern persisted at 4 wk. G util increased ≈70% in both RYGB-20cm and -40cm groups at 2 wk. At 4 wk, G util progressively increased with limb length. Furthermore, Roux limb weight, and expression of hexokinase and preproglucagon, exhibited a similar progressive increase. At 4 wk, glucagon-like peptide-1 and -2 levels were higher after RYGB-40cm, with associated increased secretion. We conclude that BP limb length modulates multiple antidiabetic mechanisms, analogous to the dose-response relationship of a drug. Early postoperatively, a longer BP limb reduces G absorp . Later, G util , Roux limb hypertrophy, hormone secretion, and hormone levels are increased with longer BP limb. Sustained high incretin levels may prevent weight regain and T2D relapse. These data provide the basis for customizing BP limb length according to patient characteristics and desired metabolic effect. NEW & NOTEWORTHY Biliopancreatic limb length in gastric bypass modulates multiple antidiabetic mechanisms, analogous to the dose-response relationship of a drug. With a longer biliopancreatic limb, Roux limb hypertrophy, increased glucose utilization, reduced glucose absorption, and sustained high incretin levels may prevent weight regain and diabetes relapse.

Improved techniques for double-balloon-enteroscopy-assisted endoscopic retrograde cholangiopancreatography

PubMed Central

Osoegawa, Takashi; Motomura, Yasuaki; Akahoshi, Kazuya; Higuchi, Naomi; Tanaka, Yoshimasa; Hisano, Terumasa; Itaba, Souichi; Gibo, Junya; Yamada, Mariko; Kubokawa, Masaru; Sumida, Yorinobu; Akiho, Hirotada; Ihara, Eikichi; Nakamura, Kazuhiko

2012-01-01

AIM: To investigate the clinical outcome of double balloon enteroscopy (DBE)-assisted endoscopic retrograde cholangiopancreatography (DB-ERCP) in patients with altered gastrointestinal anatomy. METHODS: Between September 2006 and April 2011, 47 procedures of DB-ERCP were performed in 28 patients with a Roux-en-Y total gastrectomy (n = 11), Billroth II gastrectomy (n = 15), or Roux-en-Y anastomosis with hepaticojejunostomy (n = 2). DB-ERCP was performed using a short-type DBE combined with several technical innovations such as using an endoscope attachment, marking by submucosal tattooing, selectively applying contrast medium, and CO2 insufflations. RESULTS: The papilla of Vater or hepaticojejunostomy site was reached in its entirety with a 96% success rate (45/47 procedures). There were no significant differences in the success rate of reaching the blind end with a DBE among Roux-en-Y total gastrectomy (96%), Billroth II reconstruction (94%), or pancreatoduodenectomy (100%), respectively (P = 0.91). The total successful rate of cannulation and contrast enhancement of the target bile duct in patients whom the blind end was reached with a DBE was 40/45 procedures (89%). Again, there were no significant differences in the success rate of cannulation and contrast enhancement of the target bile duct with a DBE among Roux-en-Y total gastrectomy (88 %), Billroth II reconstruction (89%), or pancreatoduodenectomy (100%), respectively (P = 0.67). Treatment was achieved in all 40 procedures (100%) in patients whom the contrast enhancement of the bile duct was successful. Common endoscopic treatments were endoscopic biliary drainage (24 procedures) and extraction of stones (14 procedures). Biliary drainage was done by placement of plastic stents. Stones extraction was done by lithotomy with the mechanical lithotripter followed by extraction with a basket or by the balloon pull-through method. Endoscopic sphincterotomy was performed in 14 procedures with a needle precutting knife using a guidewire. The mean total duration of the procedure was 93.6 ± 6.8 min and the mean time required to reach the papilla was 30.5 ± 3.7 min. The mean time required to reach the papilla tended to be shorter in Billroth II reconstruction (20.9 ± 5.8 min) than that in Roux-en-Y total gastrectomy (37.1 ± 4.9 min) but there was no significant difference (P = 0.09). A major complication occurred in one patient (3.5%); perforation of the long limb in a patient with Billroth II anastomosis. CONCLUSION: Short-type DBE combined with several technical innovations enabled us to perform ERCP in most patients with altered gastrointestinal anatomy. PMID:23239923

Unique Structural Features of Influenza Virus H15 Hemagglutinin

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tzarum, Netanel; McBride, Ryan; Nycholat, Corwin M.

Influenza A H15 viruses are members of a subgroup (H7-H10-H15) of group 2 hemagglutinin (HA) subtypes that include H7N9 and H10N8 viruses that were isolated from humans during 2013. The isolation of avian H15 viruses is, however, quite rare and, until recently, geographically restricted to wild shorebirds and waterfowl in Australia. The HAs of H15 viruses contain an insertion in the 150-loop (loop beginning at position 150) of the receptor-binding site common to this subgroup and a unique insertion in the 260-loop compared to any other subtype. Here, we show that the H15 HA has a high preference for avianmore » receptor analogs by glycan array analyses. The H15 HA crystal structure reveals that it is structurally closest to H7N9 HA, but the head domain of the H15 trimer is wider than all other HAs due to a tilt and opening of the HA1 subunits of the head domain. The extended 150-loop of the H15 HA retains the conserved conformation as in H7 and H10 HAs. Furthermore, the elongated 260-loop increases the exposed HA surface and can contribute to antigenic variation in H15 HAs. Since avian-origin H15 HA viruses have been shown to cause enhanced disease in mammalian models, further characterization and immune surveillance of H15 viruses are warranted. IMPORTANCEIn the last 2 decades, an apparent increase has been reported for cases of human infection by emerging avian influenza A virus subtypes, including H7N9 and H10N8 viruses isolated during 2013. H15 is the other member of the subgroup of influenza A virus group 2 hemagglutinins (HAs) that also include H7 and H10. H15 viruses have been restricted to Australia, but recent isolation of H15 viruses in western Siberia suggests that they could be spread more globally via the avian flyways that converge and emanate from this region. Here we report on characterization of the three-dimensional structure and receptor specificity of the H15 hemagglutinin, revealing distinct features and specificities that can aid in global surveillance of such viruses for potential spread and emerging threat to the human population.« less

Series Connected Converter for Control of Multi-Bus Spacecraft Power Utility

NASA Technical Reports Server (NTRS)

Beach, Raymond F. (Inventor); Brush, Andy (Inventor)

1997-01-01

The invention provides a power system using series connected regulators. Power from a source, such as a solar array, is processed through the regulators and provided to corresponding buses used to charge a battery and supply loads. The regulators employ a bypass loop around a DC-DC converter. The bypass loop connects a hot input of the converter to a return output, preferably though an inductor. Part of the current from the source passes through the bypass loop to the power bus. The converter bucks or boosts the voltage from the source to maintain the desired voltage at the bus. Thus, only part of the power is processed through the converter. The converter can also be used without the bypass loop to provide isolation. All of the converters can be substantially identical.

Neural mechanisms of peristalsis in the isolated rabbit distal colon: a neuromechanical loop hypothesis.

PubMed

Dinning, Phil G; Wiklendt, Lukasz; Omari, Taher; Arkwright, John W; Spencer, Nick J; Brookes, Simon J H; Costa, Marcello

2014-01-01

Propulsive contractions of circular muscle are largely responsible for the movements of content along the digestive tract. Mechanical and electrophysiological recordings of isolated colonic circular muscle have demonstrated that localized distension activates ascending and descending interneuronal pathways, evoking contraction orally and relaxation anally. These polarized enteric reflex pathways can theoretically be sequentially activated by the mechanical stimulation of the advancing contents. Here, we test the hypothesis that initiation and propagation of peristaltic contractions involves a neuromechanical loop; that is an initial gut distension activates local and oral reflex contraction and anal reflex relaxation, the subsequent movement of content then acts as new mechanical stimulus triggering sequentially reflex contractions/relaxations at each point of the gut resulting in a propulsive peristaltic contraction. In fluid filled isolated rabbit distal colon, we combined spatiotemporal mapping of gut diameter and intraluminal pressure with a new analytical method, allowing us to identify when and where active (neurally-driven) contraction or relaxation occurs. Our data indicate that gut dilation is associated with propagating peristaltic contractions, and that the associated level of dilation is greater than that preceding non-propagating contractions (2.7 ± 1.4 mm vs. 1.6 ± 1.2 mm; P < 0.0001). These propagating contractions lead to the formation of boluses that are propelled by oral active neurally driven contractions. The propelled boluses also activate neurally driven anal relaxations, in a diameter dependent manner. These data support the hypothesis that neural peristalsis is the consequence of the activation of a functional loop involving mechanical dilation which activates polarized enteric circuits. These produce propulsion of the bolus which activates further anally, polarized enteric circuits by distension, thus closing the neuromechanical loop.

A voice coil actuator driven active vibration isolation system with the consideration of flexible modes.

PubMed

Park, Kyihwan; Choi, Dongyoub; Ozer, Abdullah; Kim, Sangyoo; Lee, Yongkwan; Joo, Dongik

2008-06-01

We develop a four-mount active vibration isolation system (AVIS) using voice coil actuators. The flexible body modes in the upper plate of the AVIS can cause an instability problem due to control signal whose frequency is close to the resonant frequency of the flexible modes. The loop shaping technique is applied to reduce the amplitude of the control signal. We investigate the performances of the active vibration isolation system proposed in the word in the time domain and frequency domain by comparing to the passive isolation system.

Estradiol increases body weight loss and gut-peptide satiation after Roux-en-Y gastric bypass in ovariectomized rats.

PubMed

Asarian, Lori; Abegg, Kathrin; Geary, Nori; Schiesser, Marc; Lutz, Thomas A; Bueter, Marco

2012-08-01

Despite the fact that ∼85% of bariatric operations are performed in women, the effects of the reproductive axis function on outcome of bariatric surgery remain to be determined. Here we developed the first published model of Roux-en-Y gastric bypass (RYGB) in female rats. We show in ovariectomized rats receiving estradiol or control treatment that (1) RYGB-induced body weight loss and (2) the satiating efficacy of endogenous glucagon-like peptide-1 and cholecystokinin satiation were significantly increased in estradiol-treated rats. These data are relevant to the care of obese women, in particular perimenopausal women, undergoing bariatric surgery. Copyright © 2012 AGA Institute. Published by Elsevier Inc. All rights reserved.

Evaluation of the reverse transcription loop-mediated isothermal amplification (RT-LAMP) as a screening method for the detection of influenza viruses in the fecal materials of water birds.

PubMed

Yoshida, Hiromi; Sakoda, Yoshihiro; Endo, Mayumi; Motoshima, Masayuki; Yoshino, Fumi; Yamamoto, Naoki; Okamatsu, Masatoshi; Soejima, Takahiro; Senba, Syouhei; Kanda, Hidetoshi; Kida, Hiroshi

2011-06-01

Migratory water birds are a natural reservoir for influenza A viruses. Viruses replicate in the intestines of ducks and are shed with the fecal materials. Virus isolation from collected fecal materials, therefore, is an integral part of the surveillance of avian influenza in water birds. In the present study, reverse transcription loop-mediated isothermal amplification (RT-LAMP) was assessed for its usefulness in detecting the RNA of influenza A viruses in fecal materials. It was found that, RT-LAMP specifically and sensitively detects the matrix gene of influenza A viruses. Influenza A viruses were isolated from the fecal materials in which viral RNA were detected by RT-LAMP in 35 min. The present findings indicate that RT-LAMP is useful as a high throughput screening method for field samples prior to virus isolation, allowing the processing of hundreds of samples per day.

Impact of magnetic isolation on pointing system performance in the presence of structural flexibility

NASA Technical Reports Server (NTRS)

Seller, J.

1985-01-01

The inertial pointing stability of a gimbal pointing system (AGS) was compared with a magnetic pointing/gimbal followup system (ASPS), under certain conditions of system structural flexibility and disturbance inputs from the gimbal support structure. Separate 3 degree-of-freedom (3DOF) linear models based on NASTRAN modal flexibility data for the gimbal and support structures were generated for the ASPS configurations. Using the models inertial pointing control loops providing 6dB of gain margin and 45 deg of phase margin were defined for each configuration. The pointing loop bandwidth obtained for the ASPS is more than twice the level achieved for the AGS configuration. The AGS limit is attributed to the gimbal and support structure flexibility. As a result of the higher ASPS pointing loop bandwidth and the disturbance rejection provided by the magnetic isolation ASPS pointing performane is significantly better than that of the AGS system. The low frequency peak of the ASPS transfer function from base disturbance to payload angular motion is almost 60dB lower than AGS low frequency peak.

Comparison of DNA Microarray, Loop-Mediated Isothermal Amplification (LAMP) and Real-Time PCR with DNA Sequencing for Identification of Fusarium spp. Obtained from Patients with Hematologic Malignancies.

PubMed

de Souza, Marcela; Matsuzawa, Tetsuhiro; Sakai, Kanae; Muraosa, Yasunori; Lyra, Luzia; Busso-Lopes, Ariane Fidelis; Levin, Anna Sara Shafferman; Schreiber, Angélica Zaninelli; Mikami, Yuzuru; Gonoi, Tohoru; Kamei, Katsuhiko; Moretti, Maria Luiza; Trabasso, Plínio

2017-08-01

The performance of three molecular biology techniques, i.e., DNA microarray, loop-mediated isothermal amplification (LAMP), and real-time PCR were compared with DNA sequencing for properly identification of 20 isolates of Fusarium spp. obtained from blood stream as etiologic agent of invasive infections in patients with hematologic malignancies. DNA microarray, LAMP and real-time PCR identified 16 (80%) out of 20 samples as Fusarium solani species complex (FSSC) and four (20%) as Fusarium spp. The agreement among the techniques was 100%. LAMP exhibited 100% specificity, while DNA microarray, LAMP and real-time PCR showed 100% sensitivity. The three techniques had 100% agreement with DNA sequencing. Sixteen isolates were identified as FSSC by sequencing, being five Fusarium keratoplasticum, nine Fusarium petroliphilum and two Fusarium solani. On the other hand, sequencing identified four isolates as Fusarium non-solani species complex (FNSSC), being three isolates as Fusarium napiforme and one isolate as Fusarium oxysporum. Finally, LAMP proved to be faster and more accessible than DNA microarray and real-time PCR, since it does not require a thermocycler. Therefore, LAMP signalizes as emerging and promising methodology to be used in routine identification of Fusarium spp. among cases of invasive fungal infections.

Decoupling capabilities of split-loop resonator structure for 7 Tesla MRI surface array coils

NASA Astrophysics Data System (ADS)

Hurshkainen, A.; Kurdjumov, S.; Simovski, C.; Glybovski, S.; Melchakova, I.; van den Berg, C. A. T.; Raaijmakers, A.; Belov, P.

2017-09-01

In this work we studied electromagnetic properties of one-dimentional periodic structures composed of split-loop res-onators (SLRs) and investigated their capabilities in decoupling of two dipole antennas for full-body magnetic resonance imaging (MRI). Two different finite structures comprising a single-SLR and a double-SLR constitutive elements were studied. Numerical simulations of the structures were performed to evaluate their decoupling capabilities. As it was demonstrated two dipole antennas equipped with either a single or a double-SLR structure exhibit high isolation even for an electrically short distance between the dipoles. Double-SLR structure while dramatically improving isolation of the dipoles keeps the field created by each of the decoupled dipoles comparable with one of a single dipole inside the target area.

Phage selection of peptide "microantibodies".

PubMed

Fujiwara, Daisuke; Fujii, Ikuo

2013-01-01

A bioactive peptide capable of inhibiting protein-protein interactions has the potential to be a molecular tool for biological studies and a therapeutic by disrupting aberrant interactions involved in diseases. We have developed combinatorial libraries of peptides with helix-loop-helix structure, from which the isolated peptides have the constrained structure to reduce entropy costs in binding, resulting in high binding affinities for target molecules. Previously, we designed a de novo peptide of helix-loop-helix structure that we termed a "microantibody." Using the microantibody as a library scaffold, we have constructed a phage-display library to successfully isolate molecular-targeting peptides against a cytokine receptor (granulocyte colony-stimulating factor receptor), a protein kinase (Aurora-A), and a ganglioside (GM1). Protocols in this article describe a general procedure for the library construction and the library screening.

The inheritance of fingerprint patterns.

PubMed

Slatis, H M; Katznelson, M B; Bonné-Tamir, B

1976-05-01

Analysis of the fingerprints of 571 members of the Habbanite isolate suggest inherited patterns and pattern sequences. A genetic theory has been developed; it assumes that the basic fingerprint pattern sequence is all ulnar loops and that a variety of genes cause deviations from this pattern sequence. Genes that have been proposed include: (1) a semidominant gene for whorls on the thumbs (one homozygote has whorls on both thumbs, the other has ulnar loops on both thumbs and the heterozygote usually has two ulnar loops or one ulnar loop and one whorl); (2) a semidominant gene for whorls on the ring fingers which acts like the gene for whorls on the thumbs; (3) a dominant gene for arches on the thumbs and often on other fingers; (4) one or more dominant genes for arches on the fingers; (5) a dominant gene for whorls on all fingers except for an ulnar loop on the middle finger; (6) a dominant gene for radial loops on the index fingers, frequently associated with an arch on the middle fingers; and (7) a recessive gene for radial loops on the ring and little fingers. These genes may act independently or may show epistasis.

The inheritance of fingerprint patterns.

PubMed Central

Slatis, H M; Katznelson, M B; Bonné-Tamir, B

1976-01-01

Analysis of the fingerprints of 571 members of the Habbanite isolate suggest inherited patterns and pattern sequences. A genetic theory has been developed; it assumes that the basic fingerprint pattern sequence is all ulnar loops and that a variety of genes cause deviations from this pattern sequence. Genes that have been proposed include: (1) a semidominant gene for whorls on the thumbs (one homozygote has whorls on both thumbs, the other has ulnar loops on both thumbs and the heterozygote usually has two ulnar loops or one ulnar loop and one whorl); (2) a semidominant gene for whorls on the ring fingers which acts like the gene for whorls on the thumbs; (3) a dominant gene for arches on the thumbs and often on other fingers; (4) one or more dominant genes for arches on the fingers; (5) a dominant gene for whorls on all fingers except for an ulnar loop on the middle finger; (6) a dominant gene for radial loops on the index fingers, frequently associated with an arch on the middle fingers; and (7) a recessive gene for radial loops on the ring and little fingers. These genes may act independently or may show epistasis. PMID:1266855

A case of gastrojejunocolic fistula with steatohepatitis.

PubMed

Omori, Teppei; Tokushige, Katsutoshi; Kinoshita, Fukiko; Ito, Ayumi; Taniai, Makiko; Taneichi, Mikiko; Iizuka, Bunei; Itabashi, Michio; Nagashima, Yoji; Yamamoto, Masakazu; Nakamura, Shinichi; Hashimoto, Etsuko

2017-02-01

A man in his 30s, who had undergone retrocolic Billroth II reconstruction for perforated duodenal ulcer, presented with watery diarrhea for 2 years and suspected fatty liver. He was referred to our hospital for management of chronic diarrhea, weight loss, hepatopathy and hypoalbuminemia. Initial upper and lower gastrointestinal endoscopies were negative. Since a small bowel lesion was suspected, peroral single-balloon enteroscopy was performed, which identified feces-like residue near the Billroth II anastomotic site and a connection to the colon separate from the afferent and efferent loops. Transanal single-balloon enteroscopy identified a fistula between the gastrojejunal anastomosis and transverse colon, with the scope reaching the stomach transanally. Barium enema confirmed flow of contrast medium from the transverse colon through the fistula to the anastomotic site, allowing the diagnosis of gastrojejunocolic fistula. Liver biopsy showed relatively severe steatohepatitis (Brunt's classification: stage 2-3, grade 3). Resection of the anastomotic site and partial transverse colectomy were performed to remove the fistula, followed by Roux-en-Y reconstruction. Postoperatively, watery diarrhea resolved and the stools became normal. Hepatopathy and hypoproteinemia improved. One year later, liver biopsy showed marked improvement of steatosis. This case demonstrated marked improvement of both diarrhea/nutritional status and steatohepatitis after treatment of gastrojejunocolic fistula, suggesting that the fistula caused non-alcoholic steatohepatitis.

Isolation and characterization of two cDNA clones encoding for glutamate dehydrogenase in Nicotiana plumbaginifolia.

PubMed

Ficarelli, A; Tassi, F; Restivo, F M

1999-03-01

We have isolated two full length cDNA clones encoding Nicotiana plumbaginifolia NADH-glutamate dehydrogenase. Both clones share amino acid boxes of homology corresponding to conserved GDH catalytic domains and putative mitochondrial targeting sequence. One clone shows a putative EF-hand loop. The level of the two transcripts is affected differently by carbon source.

Atomic force microscopy capable of vibration isolation with low-stiffness Z-axis actuation.

PubMed

Ito, Shingo; Schitter, Georg

2018-03-01

For high-resolution imaging without bulky external vibration isolation, this paper presents an atomic force microscope (AFM) capable of vibration isolation with its internal Z-axis (vertical) actuators moving the AFM probe. Lorentz actuators (voice coil actuators) are used for the Z-axis actuation, and flexures guiding the motion are designed to have a low stiffness between the mover and the base. The low stiffness enables a large Z-axis actuation of more than 700 µm and mechanically isolates the probe from floor vibrations at high frequencies. To reject the residual vibrations, the probe tracks the sample by using a displacement sensor for feedback control. Unlike conventional AFMs, the Z-axis actuation attains a closed-loop control bandwidth that is 35 times higher than the first mechanical resonant frequency. The closed-loop AFM system has robustness against the flexures' nonlinearity and uses the first resonance for better sample tracking. For further improvement, feedforward control with a vibration sensor is combined, and the resulting system rejects 98.4% of vibrations by turning on the controllers. The AFM system is demonstrated by successful AFM imaging in a vibrational environment. Copyright © 2017 Elsevier B.V. All rights reserved.

[Laparoscopic Roux-en-Y gastric bypass surgery for morbid obesity. Experience at the Nacional de Ciencias Médicas y Nutrición Salvador Zubirán].

PubMed

Romero-Lbargüengoitia, María Elena; Lerman-Garber, Israel; Herrera-Hernández, Miguel Francisco; Pablo-Pantoja, Juan; Sierra-Salazar, Mauricio; López-Rosales, Federico; Zamora-Barrón, Margarita; Vargas-Martínez, Angeles; García-García, Eduardo

2009-01-01

Morbid obesity is a serious health problem associated to a significant reduction in life expectancy. To evaluate the anthropometric and metabolic changes observed in obese patients, 3, 6 and 12 months after laparoscopic Roux-en-Y gastric bypass surgery and the complications associated with the procedure. Retrospective study that included 128 consecutive obese patients submitted for bariatric surgery at the INCMNSZ (2004-2006). Their mean age was 38 +/- 10 years, 83% were women with a BMI of 48 +/- 6 Kg/m2. 65% were hypertensives, 55% had hypertriglyceridemia and 34% diabetes. A year after surgery all patients had at least reduced 20% their body weight and the percentage of excess body weight loss was 73%. The prevalence of hypertension, hypertrigliceridemia and diabetes was reduced to 24%, 17% and 12%, respectively (p < 0.001). Four patients died (3%), all of them had a leak of the anastomosis and intra-abdominal abscess. One died because pulmonary embolism, another with a myocardial infarction (after surgical reinterventions) and the other two with sepsis. Laparoscopic Roux-en-Y gastric bypass surgery in morbid obese patients favors significant reductions in body weight and associated co morbidities. This surgery is not free of complications and mortality, reason why it must be done only by surgical and interdisciplinary groups with experience in these procedures.

[Nutritional status and dietary assessment of patients with gastrectomy].

PubMed

Kamiji, Mayra Mayumi; de Oliveira, Ricardo Brandt

2003-01-01

Nutrition is a crucial factor in gastric resection surgery and the most suitable alimentary canal reconstruction method must be considered in order to reduce the risk of malnutrition. The cause of postgastrectomy malnutrition has not been clearly determined, but the mechanisms behind malnutrition are evidently multifactorial. To evaluate the nutritional status of patients who underwent different reconstructive procedures after total or subtotal gastrectomy. Fifty patients who have undergone gastrectomy for 0.5-39 years were assessed. The surgical procedures used were Billroth I in 7, Billroth II in 26, Henley in 3 and Roux-en-Y in 14 of the patients. Twenty one of them have followed gastrectomy for cancer. The nutritional status was evaluated by subjective global assessment, dietary recall and anthropometry. According to subjective global assessment, 6 of 50 patients were mild malnourished. The mean body mass index was 22 4.75 kg/m2, the average daily calorie intake was 1624 477 Kcal. Of the patients operated for cancer, those who underwent subtotal gastrectomy followed by Roux-en-Y presented higher body mass index. No relationship between the period of time since surgery with body mass index or with calorie intake was found. Among patients operated for cancer, subtotal gastrectomy with Roux-en-Y reconstruction is associated with better nutritional status. Factors other than low calorie intake are the cause of weight loss in patients with gastrectomy.

Comparison of marginal ulcer rates between antecolic and retrocolic laparoscopic Roux-en-Y gastric bypass.

PubMed

Ribeiro-Parenti, Lara; Arapis, Konstantinos; Chosidow, Denis; Marmuse, Jean-Pierre

2015-02-01

Marginal ulcer can be a serious complication after laparoscopic gastric bypass surgery. The aim of this study was to compare the rates of marginal ulcer between the antecolic and the retrocolic technique, in a large cohort of patients. Over a near 10-year period, 1,142 patients underwent laparoscopic gastric bypass surgery. The antecolic and the retrocolic technique were used in respectively 572 and 570 consecutive patients. All procedures were performed using a circular stapled gastrojejunostomy. Patients were followed for 18 to 99 months (mean 48.8 months). During follow-up, 46 patients developed a marginal ulcer (4 %), 32 in the antecolic group (5.6 %) and 14 in the retrocolic group (2.5 %). Nineteen patients (3.3 %) in the antecolic group and eight patients in the retrocolic group (1.4 %) developed early marginal ulcer (i.e., within 3 months after surgery). The mean time to onset of anastomotic ulcer symptoms after surgery was 11 months (range 0.25-72). Forty-four patients were submitted to medical treatment, and 35 patients (79.5 %) had complete resolution of their symptoms. Patients with an antecolic Roux limb develop significantly more marginal ulcers (p = 0.007) and early marginal ulcer (p = 0.033) than the patients with a retrocolic Roux limb. The antecolic technique seems to be a risk factor for appearance of marginal ulcer.

Bio-isolated dc operational amplifier. [for bioelectric measurements

NASA Technical Reports Server (NTRS)

Lee, R. D. (Inventor)

1974-01-01

A bio-isolated dc operational amplifier is described for use in making bioelectrical measurements of a patient while providing isolation of the patient from electrical shocks. The circuit contains a first operational amplifier coupled to the patient with its output coupled in a forward loop through a first optic coupler to a second operational amplifier. The output of the second operational amplifier is coupled to suitable monitoring circuitry via a feedback circuit including a second optic coupler to the input of the first operational amplifier.

Alexandre Yersin (1863-1943): discoverer of the plague bacillus, explorer and agronomist.

PubMed

Hawgood, Barbara J

2008-08-01

Alexandre Yersin was born in French Switzerland and later took French nationality. While a medical student he worked in Paris with Emile Roux to discover the exotoxin produced by the diphtheria bacillus. Two years after graduation, he left Paris for French Indochina where he was the first European to explore and map the central highlands of Vietnam. As a member of the French Colonial Health Service he was sent to Hong Kong in 1894 to investigate the outbreak of bubonic plague. He isolated from buboes the causative bacillus that later was named Yersinia pestis in his honour. In Vietnam, Yersin established a Pasteur Institute at the coastal village of Nha Trang where he lived for the rest of his life. He developed vaccines and antisera for both men and animals and, as an agronomist, he introduced the Brazilian rubber tree and Peruvian cinchona tree (for quinine) into the country. In Vietnam, as in France, the name of Yersin continues to be venerated.

Intraabdominal abscess related fungaemia caused by Rhodotorula glutinis in a non-neutropenic cancer patient.

PubMed

Diktas, H; Gulec, B; Baylan, O; Oncul, O; Turhan, V; Acar, A; Gorenek, L

2013-01-01

Rhodotorula glutinis is a rare fungal infection that is especially observed in immune-compromised patients. It is common in the skin, faeces, nails, sputum, gastrointestinal system and adenoid tissue. However, the incidence of Rhodotorula glutinis is increased in both local and systemic infections in recent years. Presented here is a case of Rhodotorula glutinis fungaemia that isolated from subhepatic abscess formation and blood in a patient who was operated with Roux-en-Y technique due to gastric adenocarcinoma. Fungal sepsis is an important cause of fever resistant to antibiotic therapy that is often taken into marginal account. It should instead be particularly considered in patients with a history of intraabdominal surgery and non-neutropenic cancer patients. The case described illustrates an episode of systemic infection by Rhodotorula glutinis, correlated with the presence of intraabdominal abscess and without central venous catheters. This is the first case of fungaemia by Rhodotorula glutinis with an intraabdominal abscess source reported from Turkey.

Polarization Dependence Suppression of Optical Fiber Grating Sensor in a π-Shifted Sagnac Loop Interferometer

PubMed Central

Son, Jaebum; Lee, Min-Kyoung; Jeong, Myung Yung; Kim, Chang-Seok

2010-01-01

In the sensing applications of optical fiber grating, it is necessary to reduce the transmission-type polarization dependence to isolate the sensing parameter. It is experimentally shown that the polarization-dependent spectrum of acousto-optic long-period fiber grating sensors can be suppressed in the transmission port of a π-shifted Sagnac loop interferometer. General expressions for the transmittance and reflectance are derived for transmission-type, reflection-type, and partially reflecting/transmitting-type polarization-dependent optical devices. The compensation of polarization dependence through the counter propagation in the Sagnac loop interferometer is quantitatively measured for a commercial in-line polarizer and an acousto-optic long-period fiber grating sensor. PMID:22399884

Hedonic Changes in Food Choices Following Roux-en-Y Gastric Bypass.

PubMed

Hansen, Thea Toft; Jakobsen, Tine Anette; Nielsen, Mette Søndergaard; Sjödin, Anders; Le Roux, Carel W; Schmidt, Julie Berg

2016-08-01

It has been suggested that a shift in food choices leading to a diet with a lower energy density plays an important role in successful weight loss after Roux-en-Y gastric bypass (RYGB) surgery. A decreased hedonic drive to consume highly palatable foods may explain these changes in eating behavior. Here, we review the literature examining postoperative changes in mechanisms contributing to hedonic drive (food preferences, reinforcing value of food, dopamine signaling, and activity reward-related brain regions). The majority of studies reviewed support that RYGB decrease the hedonic drive to consume highly palatable foods. Still, in order to fully understand the complexity of these changes, we need studies combining sociological and psychological approaches with objective measures of actual food choices examining different measures of hedonic drive.

Proflavine sensitivity of RNA processing in isolated nuclei.

PubMed Central

Yannarell, A; Niemann, M; Schumm, D E; Webb, T E

1977-01-01

The intercalating agent proflavine inhibits the processing and subsequent release of preformed messenger RNA and ribosomal RNA from isolated liver nuclei to surrogate cytoplasm. The direct effect of proflavine on these processes, as monitored in a reconstituted cell-free system, supports the theory that base-paired segments (i.e. hairpin loops) in the precursor RNA's are involved as recognition sites in nuclear RNA processing. PMID:866181

Hardware-in-the-loop grid simulator system and method

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fox, John Curtiss; Collins, Edward Randolph; Rigas, Nikolaos

A hardware-in-the-loop (HIL) electrical grid simulation system and method that combines a reactive divider with a variable frequency converter to better mimic and control expected and unexpected parameters in an electrical grid. The invention provides grid simulation in a manner to allow improved testing of variable power generators, such as wind turbines, and their operation once interconnected with an electrical grid in multiple countries. The system further comprises an improved variable fault reactance (reactive divider) capable of providing a variable fault reactance power output to control a voltage profile, therein creating an arbitrary recovery voltage. The system further comprises anmore » improved isolation transformer designed to isolate zero-sequence current from either a primary or secondary winding in a transformer or pass the zero-sequence current from a primary to a secondary winding.« less

The structure of the L3 loop from the hepatitis delta virus ribozyme: a syn cytidine.

PubMed Central

Lynch, S R; Tinoco, I

1998-01-01

The structure of the L3 central hairpin loop isolated from the antigenomic sequence of the hepatitis delta virus ribozyme with the P2 and P3 stems from the ribozyme stacked on top of the loop has been determined by NMR spectroscopy. The 26 nt stem-loop structure contains nine base pairs and a 7 nt loop (5'-UCCUCGC-3'). This hairpin loop is critical for efficient catalysis in the intact ribozyme. The structure was determined using homonuclear and heteronuclear NMR techniques on non-labeled and15N-labeled RNA oligonucleotides. The overall root mean square deviation for the structure was 1.15 A (+/- 0.28 A) for the loop and the closing C.G base pair and 0.90 A (+/- 0.18 A) for the loop and the closing C.G base pair but without the lone purine in the loop, which is not well defined in the structure. The structure indicates a U.C base pair between the nucleotides on the 5'- and 3'-ends of the loop. This base pair is formed with a single hydrogen bond involving the cytosine exocyclic amino proton and the carbonyl O4 of the uracil. The most unexpected finding in the loop is a syn cytidine. While not unprecedented, syn pyrimidines are highly unusual. This one can be confidently established by intranucleotide distances between the ribose and the base determined by NMR spectroscopy. A similar study of the structure of this loop showed a somewhat different three-dimensional structure. A discussion of differences in the two structures, as well as possible sites of interaction with the cleavage site, will be presented. PMID:9461457

Gastric bypass surgery - discharge

MedlinePlus

... bypass - discharge; Gastric bypass - Roux-en-Y - discharge; Obesity gastric bypass discharge; Weight loss - gastric bypass discharge ... al. Bariatric surgery versus non-surgical treatment for obesity: a systematic review and meta-analysis of randomised ...

Dumping Syndrome

MedlinePlus

... also part of treatment for stomach cancer, esophageal cancer and other conditions. These surgeries include: Gastrectomy, in which a portion or all of your stomach is removed. Gastric bypass surgery (Roux-en-Y operation), which is ...

Efficacy and safety of bariatric surgery for craniopharyngioma-related hypothalamic obesity: a matched case-control study with 2 years of follow-up.

PubMed

Wijnen, M; Olsson, D S; van den Heuvel-Eibrink, M M; Wallenius, V; Janssen, J A M J L; Delhanty, P J D; van der Lely, A J; Johannsson, G; Neggers, S J C M M

2017-02-01

Hypothalamic obesity is a devastating consequence of craniopharyngioma. Bariatric surgery could be a promising therapeutic option. However, its efficacy and safety in patients with craniopharyngioma-related hypothalamic obesity remain largely unknown. We investigated the efficacy of bariatric surgery for inducing weight loss in patients with craniopharyngioma-related hypothalamic obesity. In addition, we studied the safety of bariatric surgery regarding its effects on hormone replacement therapy for pituitary insufficiency. In this retrospective matched case-control study, we compared weight loss after bariatric surgery (that is, Roux-en-Y gastric bypass and sleeve gastrectomy) between eight patients with craniopharyngioma-related hypothalamic obesity and 75 controls with 'common' obesity during 2 years of follow-up. We validated our results at 1 year of follow-up in a meta-analysis. In addition, we studied alterations in hormone replacement therapy after bariatric surgery in patients with craniopharyngioma. Mean weight loss after bariatric surgery was 19% vs 25% (difference -6%, 95% confidence of interval (CI) -14.1 to 4.6; P=0.091) at 2 years of follow-up in patients with craniopharyngioma-related hypothalamic obesity compared with control subjects with 'common' obesity. Mean weight loss was 25% vs 29% (difference -4%, 95% CI -11.6 to 8.1; P=0.419) after Roux-en-Y gastric bypass and 10% vs 20% (difference -10%, 95% CI -14.1 to -6.2; P=0.003) after sleeve gastrectomy at 2 years of follow-up in patients with craniopharyngioma-related hypothalamic obesity vs control subjects with 'common' obesity. Our meta-analysis demonstrated significant weight loss 1 year after Roux-en-Y gastric bypass, but not after sleeve gastrectomy. Seven patients with craniopharyngioma suffered from pituitary insufficiency; three of them required minor adjustments in hormone replacement therapy after bariatric surgery. Weight loss after Roux-en-Y gastric bypass, but not sleeve gastrectomy, was comparable between patients with craniopharyngioma-related hypothalamic obesity and control subjects with 'common' obesity at 2 years of follow-up. Bariatric surgery seems safe regarding its effects on hormone replacement therapy.

Roux-en-Y gastric bypass stands the test of time: 5-year results in low body mass index (30-35 kg/m(2)) Indian patients with type 2 diabetes mellitus.

PubMed

Lakdawala, Muffazal; Shaikh, Shehla; Bandukwala, Saifee; Remedios, Carlyne; Shah, Miloni; Bhasker, Aparna Govil

2013-01-01

Our objective was to evaluate the long-term results of laparoscopic Roux-en-Y gastric bypass on excess weight loss, remission of the metabolic syndrome, and complications in Indian patients with uncontrolled type 2 diabetes mellitus (T2DM) with a body mass index of 30-35 kg/m(2). The setting was a corporate hospital in Mumbai, India. The present prospective observational study was begun in January 2006. A total of 52 patients with uncontrolled T2DM and a body mass index of 30-35 kg/m(2) elected to undergo laparoscopic Roux-en-Y gastric bypass. The duration of T2DM was 3.5-14.5 years (median 8.4). Of the 52 patients, 61.5% had hypertension and 59.6% had dyslipidemia. Remission of T2DM and other components of the metabolic syndrome were assessed. All patients were followed up for 5 years. The median percentage of excess weight loss was 72.2% at 1 year and 67.8% at 5 years. Of the 52 patients, 84.6% had achieved euglycemia and 73.1% had achieved complete remission, 23.1% partial remission, and 3.84% no remission at 1 year. Weight regain occurred in 8 patients. They required antihypertensive drugs and statins, decreasing the complete remission rate to 57.7% and partial remission rate to 38.5% at 5 years. However, 96.2% improvement in metabolic status was found at the end of 5 years. Laparoscopic Roux-en-Y gastric bypass is a safe, efficacious, and cost-effective treatment for uncontrolled T2DM in patients with a body mass index of 30-35 kg/m(2). Early-onset T2DM, better weight loss, and greater C-peptide levels were predictors of success after surgery. The improvement after surgery in hyperglycemia, hypertension, and dyslipidemia could help in controlling the occurrence of micro- and macrovascular complications and decrease the morbidity and mortality associated with T2DM. Copyright © 2013 American Society for Metabolic and Bariatric Surgery. Published by Elsevier Inc. All rights reserved.

Passive-bending, short-type single-balloon enteroscope for endoscopic retrograde cholangiopancreatography in Roux-en-Y anastomosis patients.

PubMed

Yamauchi, Hiroshi; Kida, Mitsuhiro; Okuwaki, Kosuke; Miyazawa, Shiro; Iwai, Tomohisa; Tokunaga, Shuko; Takezawa, Miyoko; Imaizumi, Hiroshi; Koizumi, Wasaburo

2015-02-07

To evaluate short-type-single-balloon enteroscope (SBE) with passive-bending, high-force transmission functions for endoscopic retrograde cholangiopancreatography (ERCP) in patients with Roux-en-Y anastomosis. Short-type SBE with this technology (SIF-Y0004-V01; working length, 1520 mm; channel diameter, 3.2 mm) was used to perform 50 ERCP procedures in 37 patients with Roux-en-Y anastomosis. The rate of reaching the blind end, time required to reach the blind end, diagnostic and therapeutic success rates, and procedure time and complications were studied retrospectively and compared with the results of 34 sessions of ERCP performed using a short-type SBE without this technology (SIF-Y0004; working length, 1520 mm; channel diameter, 3.2 mm) in 25 patients. The rate of reaching the blind end was 90% with SIF-Y0004-V01 and 91% with SIF-Y0004 (P = 0.59). The median time required to reach the papilla was significantly shorter with SIF-Y0004-V01 than with SIF-Y0004 (16 min vs 24 min, P = 0.04). The diagnostic success rate was 93% with SIF-Y0004-V01 and 84% with SIF-Y0004 (P = 0.17). The therapeutic success rate was 95% with SIF-Y0004-V01 and 96% with SIF-Y0004 (P = 0.68). The median procedure time was 40 min with SIF-Y0004-V01 and 36 min with SIF-Y0004 (P = 0.50). The incidence of hyperamylasemia was 6.0% in the SIF-Y0004-V01 group and 14.7% in the SIF-Y0004 group (P = 0.723). The incidence of pancreatitis was 0% in the SIF-Y0004-V01 group and 5.9% in the SIF-Y0004 group (P > 0.999). The incidence of gastrointestinal perforation was 2.0% (1/50) in the SIF-Y0004-V01 group and 2.9% (1/34) in the SIF-Y0004 group (P > 0.999). SIF-Y0004-V01 is useful for ERCP in patients with Roux-en-Y anastomosis and may reduce the time required to reach the blind end.

Multi-Purpose Thermal Hydraulic Loop: Advanced Reactor Technology Integral System Test (ARTIST) Facility for Support of Advanced Reactor Technologies

DOE Office of Scientific and Technical Information (OSTI.GOV)

James E. O'Brien; Piyush Sabharwall; SuJong Yoon

2001-11-01

Effective and robust high temperature heat transfer systems are fundamental to the successful deployment of advanced reactors for both power generation and non-electric applications. Plant designs often include an intermediate heat transfer loop (IHTL) with heat exchangers at either end to deliver thermal energy to the application while providing isolation of the primary reactor system. In order to address technical feasibility concerns and challenges a new high-temperature multi-fluid, multi-loop test facility “Advanced Reactor Technology Integral System Test facility” (ARTIST) is under development at the Idaho National Laboratory. The facility will include three flow loops: high-temperature helium, molten salt, and steam/water.more » Details of some of the design aspects and challenges of this facility, which is currently in the conceptual design phase, are discussed« less

Spatiotemporal Dynamics of a Network of Coupled Time-Delay Digital Tanlock Loops

NASA Astrophysics Data System (ADS)

Paul, Bishwajit; Banerjee, Tanmoy; Sarkar, B. C.

The time-delay digital tanlock loop (TDTLs) is an important class of phase-locked loop that is widely used in electronic communication systems. Although nonlinear dynamics of an isolated TDTL has been studied in the past but the collective behavior of TDTLs in a network is an important topic of research and deserves special attention as in practical communication systems separate entities are rarely isolated. In this paper, we carry out the detailed analysis and numerical simulations to explore the spatiotemporal dynamics of a network of a one-dimensional ring of coupled TDTLs with nearest neighbor coupling. The equation representing the network is derived and we carry out analytical calculations using the circulant matrix formalism to obtain the stability criteria. An extensive numerical simulation reveals that with the variation of gain parameter and coupling strength the network shows a variety of spatiotemporal dynamics such as frozen random pattern, pattern selection, spatiotemporal intermittency and fully developed spatiotemporal chaos. We map the distinct dynamical regions of the system in two-parameter space. Finally, we quantify the spatiotemporal dynamics by using quantitative measures like Lyapunov exponent and the average quadratic deviation of the full network.

Vibration isolation and dual-stage actuation pointing system for space precision payloads

NASA Astrophysics Data System (ADS)

Kong, Yongfang; Huang, Hai

2018-02-01

Pointing and stability requirements for future space missions are becoming more and more stringent. This work follows the pointing control method which consists of a traditional spacecraft attitude control system and a payload active pointing loop, further proposing a vibration isolation and dual-stage actuation pointing system for space precision payloads based on a soft Stewart platform. Central to the concept is using the dual-stage actuator instead of the traditional voice coil motor single-stage actuator to improve the payload active pointing capability. Based on a specified payload, the corresponding platform was designed to be installed between the spacecraft bus and the payload. The performance of the proposed system is demonstrated by preliminary closed-loop control investigations in simulations. With the ordinary spacecraft bus, the line-of-sight pointing accuracy can be controlled to below a few milliarcseconds in tip and tilt. Meanwhile, utilizing the voice coil motor with the softening spring in parallel, which is a portion of the dual-stage actuator, the system effectively achieves low-frequency motion transmission and high-frequency vibration isolation along the other four degree-of-freedom directions.

Statistical evidence for the existence of Alfvénic turbulence in solar coronal loops

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Jiajia; McIntosh, Scott W.; Bethge, Christian

2014-12-10

Recent observations have demonstrated that waves capable of carrying large amounts of energy are ubiquitous throughout the solar corona. However, the question of how this wave energy is dissipated (on which timescales and length scales) and released into the plasma remains largely unanswered. Both analytic and numerical models have previously shown that Alfvénic turbulence may play a key role not only in the generation of the fast solar wind, but in the heating of coronal loops. In an effort to bridge the gap between theory and observations, we expand on a recent study by analyzing 37 clearly isolated coronal loopsmore » using data from the Coronal Multi-channel Polarimeter instrument. We observe Alfvénic perturbations with phase speeds which range from 250 to 750 km s{sup –1} and periods from 140 to 270 s for the chosen loops. While excesses of high-frequency wave power are observed near the apex of some loops (tentatively supporting the onset of Alfvénic turbulence), we show that this excess depends on loop length and the wavelength of the observed oscillations. In deriving a proportional relationship between the loop length/wavelength ratio and the enhanced wave power at the loop apex, and from the analysis of the line widths associated with these loops, our findings are supportive of the existence of Alfvénic turbulence in coronal loops.« less

Closed-Loop HIRF Experiments Performed on a Fault Tolerant Flight Control Computer

NASA Technical Reports Server (NTRS)

Belcastro, Celeste M.

1997-01-01

ABSTRACT Closed-loop HIRF experiments were performed on a fault tolerant flight control computer (FCC) at the NASA Langley Research Center. The FCC used in the experiments was a quad-redundant flight control computer executing B737 Autoland control laws. The FCC was placed in one of the mode-stirred reverberation chambers in the HIRF Laboratory and interfaced to a computer simulation of the B737 flight dynamics, engines, sensors, actuators, and atmosphere in the Closed-Loop Systems Laboratory. Disturbances to the aircraft associated with wind gusts and turbulence were simulated during tests. Electrical isolation between the FCC under test and the simulation computer was achieved via a fiber optic interface for the analog and discrete signals. Closed-loop operation of the FCC enabled flight dynamics and atmospheric disturbances affecting the aircraft to be represented during tests. Upset was induced in the FCC as a result of exposure to HIRF, and the effect of upset on the simulated flight of the aircraft was observed and recorded. This paper presents a description of these closed- loop HIRF experiments, upset data obtained from the FCC during these experiments, and closed-loop effects on the simulated flight of the aircraft.

Ion-irradiation-induced microstructural modifications in ferritic/martensitic steel T91

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Xiang; Miao, Yinbin; Li, Meimei

In this paper, in situ transmission electron microscopy investigations were carried out to study the microstructural evolution of ferritic/martensitic steel T91 under 1 MeV Krypton ion irradiation up to 4.2 x 10(15) ions/cm(2) at 573 K, 673 K, and 773 K. At 573 K, grown-in defects are strongly modified by black dot loops, and dislocation networks together with black-dot loops were observed after irradiation. At 673 K and 773 K, grown-in defects are only partially modified by dislocation loops; isolated loops and dislocation segments were commonly found after irradiation. Post irradiation examination indicates that at 4.2 x 1015 ions/cm(2), aboutmore » 51% of the loops were a(0)/2 < 111 > type for the 673 K irradiation, and the dominant loop type was a(0)< 100 > for the 773 K irradiation. Finally, a dispersed barrier hardening model was employed to estimate the change in yield strength, and the calculated ion data were found to follow the similar trend as the existing neutron data with an offset of 100-150 MPa. (C) 2017 Elsevier B.V. All rights reserved.« less

Evaluation of Safety and Efficacy of the EndoLift Liver Retractor

ClinicalTrials.gov

2015-08-03

Minimally Invasive Surgical Procedure; Laparoscopic Gastric Banding; Laparoscopic Roux-en-Y Gastric Bypass; Laparoscopic Sleeve Gastrectomy; Laparoscopic Fundoplication Procedure; Laparoscopic Heller Myotomy; Laparoscopic Paraesophageal Hernia Repair; Laparoscopic Gastric Resection

Upper gastrointestinal series after Roux-en-Y gastric bypass for morbid obesity: effectiveness in leakage detection. a systematic review of the literature.

PubMed

Quartararo, Giovanni; Facchiano, Enrico; Scaringi, Stefano; Liscia, Gadiel; Lucchese, Marcello

2014-07-01

The aim of this study is to evaluate the results of routine and selective postoperative upper gastrointestinal series (UGIS) after Roux-en-Y gastric bypass (RYGB) for morbid obesity in different published series to assessing its utility and cost-effectiveness. A search in PubMed's MEDLINE was performed for English-spoken articles published from January 2002 to December 2012. Keywords used were upper GI series, RYGB, and obesity. Only cases of anastomotic leaks were considered. A total of 22 studies have been evaluated, 15 recommended a selective use of postoperative UGIS. No differences in leakage detection or in clinical benefit between routine and selective approaches were found. Tachycardia and respiratory distress represent the best criteria to perform UGIS for early diagnosis of anastomotic leak after a RYGB.

Diagnosis and Management of Perforated Duodenal Ulcers following Roux-En-Y Gastric Bypass: A Report of Two Cases and a Review of the Literature.

PubMed

Iskandar, Mazen E; Chory, Fiona M; Goodman, Elliot R; Surick, Burton G

2015-01-01

Perforated duodenal ulcers are rare complications seen after roux-en-Y gastric bypass (RYGP). They often present as a diagnostic dilemma as they rarely present with pneumoperitoneum on radiologic evaluation. There is no consensus as to the pathophysiology of these ulcers; however expeditious treatment is necessary. We present two patients with perforated duodenal ulcers and a distant history of RYGP who were successfully treated. Their individual surgical management is discussed as well as a literature review. We conclude that, in patients who present with acute abdominal pain and a history of RYGB, perforated ulcer needs to be very high in the differential diagnosis even in the absence of pneumoperitoneum. In these patients an early surgical exploration is paramount to help diagnose and treat these patients.

Diagnosis and Management of Perforated Duodenal Ulcers following Roux-En-Y Gastric Bypass: A Report of Two Cases and a Review of the Literature

PubMed Central

Iskandar, Mazen E.; Chory, Fiona M.; Goodman, Elliot R.; Surick, Burton G.

2015-01-01

Perforated duodenal ulcers are rare complications seen after roux-en-Y gastric bypass (RYGP). They often present as a diagnostic dilemma as they rarely present with pneumoperitoneum on radiologic evaluation. There is no consensus as to the pathophysiology of these ulcers; however expeditious treatment is necessary. We present two patients with perforated duodenal ulcers and a distant history of RYGP who were successfully treated. Their individual surgical management is discussed as well as a literature review. We conclude that, in patients who present with acute abdominal pain and a history of RYGB, perforated ulcer needs to be very high in the differential diagnosis even in the absence of pneumoperitoneum. In these patients an early surgical exploration is paramount to help diagnose and treat these patients. PMID:25949843

The physiology of altered eating behaviour after Roux-en-Y gastric bypass.

PubMed

le Roux, Carel W; Bueter, Marco

2014-09-01

Obesity and its related comorbidities can be detrimental for the affected individual, as well as constituting a major challenge to public health systems worldwide. Currently, the most effective treatment option leading to clinically significant and maintained body weight loss and reduction in obesity-related morbidity and mortality is obesity surgery, which is recommended for patients with a body mass index of >40 kg m(-2), or >35 kg m(-2) if obesity-associated comorbidities, such as type 2 diabetes mellitus, are present. This report focuses on the altered eating behaviour after the most common of these operations, the Roux-en-Y gastric bypass. Animal and human experiments designed to understand the underlying physiological mechanisms of altered taste and appetite are discussed. © 2014 The Authors. Experimental Physiology © 2014 The Physiological Society.

[Application of damage control surgery idea in the treatment of severe pancreatic duodenal injury].

PubMed

Zhu, Ren-wu; Gu, Ye-chun; Jiang, Yang-gui; Zhao, Mao-sen; Shen, Xian

2013-12-01

To explore the significance of damage control surgery (DCS) in the treatments of severe pancreaticoduodenal injuries. Clinical data of 19 patients with severe pancreaticoduodenal injuries managed with DCS approach in Wenzhou Hospital of Integrated Traditional Chinese and Western Medicine and the First Affiliated Hospital of Wenzhou Medical College from March 2005 to January 2013 were analyzed retrospectively. Three cases were cured after damage control operation and postoperative ICU resuscitation treatment. Twelve cases underwent definite operations (distal pancreaticojejunal Roux-en-Y anastomosis, proximal duodenojejunal Roux-en-Y anastomosis or pancreaticoduodenectomy) after damage control operation and postoperative ICU resuscitation treatment and cured. Four cases died after damage control operation due to multiple organ failure and the mortality was 21.1%. Application of DCS approach can improve the prognosis of patients with severe pancreaticoduodenal injuries.

The Effect of Preoperative Type 2 Diabetes and Physical Fitness on Mental Health and Health-Related Quality of Life after Roux-en-Y Gastric Bypass

PubMed Central

Wimmelmann, Cathrine L.; Lund, Michael T.; Hansen, Merethe; Dela, Flemming; Mortensen, Erik L.

2016-01-01

Objective. To investigate the predictive value of type 2 diabetes and lack of physical activity for mental health and health-related quality of life after Roux-en-Y gastric bypass. Method. Forty severely obese patients undergoing Roux-en-Y gastric bypass were included in the GASMITO study. Information about physiological and psychological factors was prospectively assessed at four time points, two times prior to surgery and two times after surgery. Measures included oral and intravenous glucose tolerance tests, VO2max test, Symptoms Checklist (SCL-90), Short Form Health Survey 36 (SF-36), Body Image Questionnaire, and a questionnaire assessing sociodemographic factors and medical status. Results. Mean % excess weight loss was 65% (±12) at 18-month follow-up and 50% of the participants with diabetes experienced total remission. Also, significant improvements were observed with regard to physical fitness, mental distress, health-related quality of life, and weight-related body image (p < 0.05). The interaction between follow-up time and type 2 diabetes at baseline significantly predicted six of the thirteen psychological subscales (p < 0.05) and, across the follow-ups, physical fitness level made modest contributions to variations in mental symptoms and HRQOL but not weight-related body image. Conclusion. The results suggest that baseline difference in mental symptoms and physical HRQOL between diabetic and nondiabetic patients declines across follow-ups and resolves around the time of surgery. PMID:27379183

Logic analysis of complex systems by characterizing failure phenomena to achieve diagnosis and fault-isolation

NASA Technical Reports Server (NTRS)

Wong, J. T.; Andre, W. L.

1981-01-01

A recent result shows that, for a certain class of systems, the interdependency among the elements of such a system together with the elements constitutes a mathematical structure a partially ordered set. It is called a loop free logic model of the system. On the basis of an intrinsic property of the mathematical structure, a characterization of system component failure in terms of maximal subsets of bad test signals of the system was obtained. Also, as a consequence, information concerning the total number of failure components in the system was deduced. Detailed examples are given to show how to restructure real systems containing loops into loop free models for which the result is applicable.

Entropy of nonrotating isolated horizons in Lovelock theory from loop quantum gravity

NASA Astrophysics Data System (ADS)

Wang, Jing-Bo; Huang, Chao-Guang; Li, Lin

2016-08-01

In this paper, the BF theory method is applied to the nonrotating isolated horizons in Lovelock theory. The final entropy matches the Wald entropy formula for this theory. We also confirm the conclusion obtained by Bodendorfer et al. that the entropy is related to the flux operator rather than the area operator in general diffeomorphic-invariant theory. Supported by National Natural Science Foundation of China (11275207)

Unmixing Magnetic Hysteresis Loops

NASA Astrophysics Data System (ADS)

Heslop, D.; Roberts, A. P.

2012-04-01

Magnetic hysteresis loops provide important information in rock and environmental magnetic studies. Natural samples often contain an assemblage of magnetic particles composed of components with different origins. Each component potentially carries important environmental information. Hysteresis loops, however, provide information concerning the bulk magnetic assemblage, which makes it difficult to isolate the specific contributions from different sources. For complex mineral assemblages an unmixing strategy with which to separate hysteresis loops into their component parts is therefore essential. Previous methods to unmix hysteresis data have aimed at separating individual loops into their constituent parts using libraries of type-curves thought to correspond to specific mineral types. We demonstrate an alternative approach, which rather than decomposing a single loop into monomineralic contributions, examines a collection of loops to determine their constituent source materials. These source materials may themselves be mineral mixtures, but they provide a genetically meaningful decomposition of a magnetic assemblage in terms of the processes that controlled its formation. We show how an empirically derived hysteresis mixing space can be created, without resorting to type-curves, based on the co-variation within a collection of measured loops. Physically realistic end-members, which respect the expected behaviour and symmetries of hysteresis loops, can then be extracted from the mixing space. These end-members allow the measured loops to be described as a combination of invariant parts that are assumed to represent the different sources in the mixing model. Particular attention is paid to model selection and estimating the complexity of the mixing model, specifically, how many end-members should be included. We demonstrate application of this approach using lake sediments from Butte Valley, northern California. Our method successfully separates the hysteresis loops into sources with a variety of terrigenous and authigenic origins.

Identification of ochratoxin A producing Aspergillus carbonarius and A. niger clade isolated from grapes using the loop-mediated isothermal amplification (LAMP) reaction.

PubMed

Storari, M; von Rohr, R; Pertot, I; Gessler, C; Broggini, G A L

2013-04-01

To develop two assays based on the loop-mediated isothermal amplification (LAMP) of DNA for the quick and specific identification of Aspergillus carbonarius and ochratoxigenic strains of the Aspergillus niger clade isolated from grapes. Two sets of primers were designed based on the polyketide synthase genes involved or putatively involved in ochratoxin A (OTA) biosynthesis in A. carbonarius and A. niger clade. Hydroxynaphthol blue was used as indirect method to indicate DNA amplification. The limit of detection of both assays was comparable to that of a PCR reaction. Specificities of the reactions were tested using DNA from different black aspergilli isolated from grapes. The two LAMP assays were then used to identify A. carbonarius and ochratoxigenic A. niger and A. awamori grown in pure cultures without a prior DNA extraction. The two LAMP assays permitted to quickly and specifically identify DNA from OTA-producing black aspergilli, as well as isolates grown in pure culture. Monitoring vineyards for the presence of OTA-producing strains is part of the measures to minimize the occurrence of OTA in grape products. The two LAMP assays developed here could be potentially used to speed the screening process of vineyards for the presence of OTA-producing black aspergilli. © 2013 The Society for Applied Microbiology.

Fault Management Metrics

NASA Technical Reports Server (NTRS)

Johnson, Stephen B.; Ghoshal, Sudipto; Haste, Deepak; Moore, Craig

2017-01-01

This paper describes the theory and considerations in the application of metrics to measure the effectiveness of fault management. Fault management refers here to the operational aspect of system health management, and as such is considered as a meta-control loop that operates to preserve or maximize the system's ability to achieve its goals in the face of current or prospective failure. As a suite of control loops, the metrics to estimate and measure the effectiveness of fault management are similar to those of classical control loops in being divided into two major classes: state estimation, and state control. State estimation metrics can be classified into lower-level subdivisions for detection coverage, detection effectiveness, fault isolation and fault identification (diagnostics), and failure prognosis. State control metrics can be classified into response determination effectiveness and response effectiveness. These metrics are applied to each and every fault management control loop in the system, for each failure to which they apply, and probabilistically summed to determine the effectiveness of these fault management control loops to preserve the relevant system goals that they are intended to protect.

Semi-active control of helicopter vibration using controllable stiffness and damping devices

NASA Astrophysics Data System (ADS)

Anusonti-Inthra, Phuriwat

Semi-active concepts for helicopter vibration reduction are developed and evaluated in this dissertation. Semi-active devices, controllable stiffness devices or controllable orifice dampers, are introduced; (i) in the blade root region (rotor-based concept) and (ii) between the rotor and the fuselage as semi-active isolators (in the non-rotating frame). Corresponding semi-active controllers for helicopter vibration reduction are also developed. The effectiveness of the rotor-based semi-active vibration reduction concept (using stiffness and damping variation) is demonstrated for a 4-bladed hingeless rotor helicopter in moderate- to high-speed forward flight. A sensitivity study shows that the stiffness variation of root element can reduce hub vibrations when proper amplitude and phase are used. Furthermore, the optimal semi-active control scheme can determine the combination of stiffness variations that produce significant vibration reduction in all components of vibratory hub loads simultaneously. It is demonstrated that desired cyclic variations in properties of the blade root region can be practically achieved using discrete controllable stiffness devices and controllable dampers, especially in the flap and lag directions. These discrete controllable devices can produce 35--50% reduction in a composite vibration index representing all components of vibratory hub loads. No detrimental increases are observed in the lower harmonics of blade loads and blade response (which contribute to the dynamic stresses) and controllable device internal loads, when the optimal stiffness and damping variations are introduced. The effectiveness of optimal stiffness and damping variations in reducing hub vibration is retained over a range of cruise speeds and for variations in fundamental rotor properties. The effectiveness of the semi-active isolator is demonstrated for a simplified single degree of freedom system representing the semi-active isolation system. The rotor, represented by a lumped mass under harmonic force excitation, is supported by a spring and a parallel damper on the fuselage (assumed to have infinite mass). Properties of the spring or damper can then be controlled to reduce transmission of the force into the fuselage or the support structure. This semi-active isolation concept can produce additional 30% vibration reduction beyond the level achieved by a passive isolator. Different control schemes (i.e. open-loop, closed-loop, and closed-loop adaptive schemes) are developed and evaluated to control transmission of vibratory loads to the support structure (fuselage), and it is seen that a closed-loop adaptive controller is required to retain vibration reduction effectiveness when there is a change in operating condition. (Abstract shortened by UMI.)

Oxbows and Cutoffs in Idaeus Fossae

NASA Image and Video Library

2013-08-21

As rivers age they can meander and occasionally these meanders get so pronounced that the river cuts off these curving loops at their narrow end leaving them as isolated as oxbow lakes. Image from NASA Mars Reconnaissance Orbiter.

Loop-mediated isothermal amplification (LAMP) assay-A rapid detection tool for identifying red fox (Vulpes vulpes) DNA in the carcasses of harbour porpoises (Phocoena phocoena).

PubMed

Heers, Teresa; van Neer, Abbo; Becker, André; Grilo, Miguel Luca; Siebert, Ursula; Abdulmawjood, Amir

2017-01-01

Carcasses of wild animals are often visited by different scavengers. However, determining which scavenger caused certain types of bite marks is particularly difficult and knowledge thereof is lacking. Therefore, a loop-mediated isothermal amplification (LAMP) assay (target sequence cytochrome b) was developed to detect red fox DNA in carcasses of harbour porpoises. The MSwab™ method for direct testing without prior DNA isolation was validated. As a detection device, the portable real-time fluorometer Genie® II was used, which yields rapid results and can be used in field studies without huge laboratory equipment. In addition to in vitro evaluation and validation, a stranded and scavenged harbour porpoise carcass was successfully examined for red fox DNA residues. The developed LAMP method is a valuable diagnostic tool for confirming presumable red fox bite wounds in harbour porpoises without further DNA isolation steps.

Selection of the simplest RNA that binds isoleucine

PubMed Central

LOZUPONE, CATHERINE; CHANGAYIL, SHANKAR; MAJERFELD, IRENE; YARUS, MICHAEL

2003-01-01

We have identified the simplest RNA binding site for isoleucine using selection-amplification (SELEX), by shrinking the size of the randomized region until affinity selection is extinguished. Such a protocol can be useful because selection does not necessarily make the simplest active motif most prominent, as is often assumed. We find an isoleucine binding site that behaves exactly as predicted for the site that requires fewest nucleotides. This UAUU motif (16 highly conserved positions; 27 total), is also the most abundant site in successful selections on short random tracts. The UAUU site, now isolated independently at least 63 times, is a small asymmetric internal loop. Conserved loop sequences include isoleucine codon and anticodon triplets, whose nucleotides are required for amino acid binding. This reproducible association between isoleucine and its coding sequences supports the idea that the genetic code is, at least in part, a stereochemical residue of the most easily isolated RNA–amino acid binding structures. PMID:14561881

Rupture loop annex ion exchange RLAIX vault deactivation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ham, J.E.; Harris, D.L., Westinghouse Hanford

This engineering report documents the deactivation, stabilization and final conditions of the Rupture Loop Annex Ion Exchange (RLAIX) Vault located northwest of the 309 Building`s Plutonium Recycle Test Reactor (PRTR). Twelve ion exchange columns, piping debris, and column liquid were removed from the vault, packaged and shipped for disposal. The vault walls and floor were decontaminated, and portions of the vault were painted to fix loose contamination. Process piping and drains were plugged, and the cover blocks and rain cover were installed. Upon closure,the vault was empty, stabilized, isolated.

Isolation of the new antigen receptor from wobbegong sharks, and use as a scaffold for the display of protein loop libraries.

PubMed

Nuttall, S D; Krishnan, U V; Hattarki, M; De Gori, R; Irving, R A; Hudson, P J

2001-08-01

The new antigen receptor (NAR) from nurse sharks consists of an immunoglobulin variable domain attached to five constant domains, and is hypothesised to function as an antigen-binding antibody-like molecule. To determine whether the NAR is present in other species we have isolated a number of new antigen receptor variable domains from the spotted wobbegong shark (Orectolobus maculatus) and compared their structure to that of the nurse shark protein. To determine whether these wNARs can function as antigen-binding proteins, we have used them as scaffolds for the construction of protein libraries in which the CDR3 loop was randomised, and displayed the resulting recombinant domains on the surface of fd bacteriophages. On selection against several protein antigens, the highest affinity wNAR proteins were generated against the Gingipain K protease from Porphyromonas gingivalis. One wNAR protein bound Gingipain K specifically by ELISA and BIAcore analysis and, when expressed in E. coli and purified by affinity chromatography, eluted from an FPLC column as a single peak consistent with folding into a monomeric protein. Naturally occurring nurse shark and wobbegong NAR variable domains exhibit conserved cysteine residues within the CDR1 and CDR3 loops which potentially form disulphide linkages and enhance protein stability; proteins isolated from the in vitro NAR wobbegong library showed similar selection for such paired cysteine residues. Thus, the New Antigen Receptor represents a protein scaffold with possible stability advantages over conventional antibodies when used in in vitro molecular libraries.

Effect of Laparoscopic Sleeve Gastrectomy vs Laparoscopic Roux-en-Y Gastric Bypass on Weight Loss at 5 Years Among Patients With Morbid Obesity: The SLEEVEPASS Randomized Clinical Trial.

PubMed

Salminen, Paulina; Helmiö, Mika; Ovaska, Jari; Juuti, Anne; Leivonen, Marja; Peromaa-Haavisto, Pipsa; Hurme, Saija; Soinio, Minna; Nuutila, Pirjo; Victorzon, Mikael

2018-01-16

Laparoscopic sleeve gastrectomy for treatment of morbid obesity has increased substantially despite the lack of long-term results compared with laparoscopic Roux-en-Y gastric bypass. To determine whether laparoscopic sleeve gastrectomy and laparoscopic Roux-en-Y gastric bypass are equivalent for weight loss at 5 years in patients with morbid obesity. The Sleeve vs Bypass (SLEEVEPASS) multicenter, multisurgeon, open-label, randomized clinical equivalence trial was conducted from March 2008 until June 2010 in Finland. The trial enrolled 240 morbidly obese patients aged 18 to 60 years, who were randomly assigned to sleeve gastrectomy or gastric bypass with a 5-year follow-up period (last follow-up, October 14, 2015). Laparoscopic sleeve gastrectomy (n = 121) or laparoscopic Roux-en-Y gastric bypass (n = 119). The primary end point was weight loss evaluated by percentage excess weight loss. Prespecified equivalence margins for the clinical significance of weight loss differences between gastric bypass and sleeve gastrectomy were -9% to +9% excess weight loss. Secondary end points included resolution of comorbidities, improvement of quality of life (QOL), all adverse events (overall morbidity), and mortality. Among 240 patients randomized (mean age, 48 [SD, 9] years; mean baseline body mass index, 45.9, [SD, 6.0]; 69.6% women), 80.4% completed the 5-year follow-up. At baseline, 42.1% had type 2 diabetes, 34.6% dyslipidemia, and 70.8% hypertension. The estimated mean percentage excess weight loss at 5 years was 49% (95% CI, 45%-52%) after sleeve gastrectomy and 57% (95% CI, 53%-61%) after gastric bypass (difference, 8.2 percentage units [95% CI, 3.2%-13.2%], higher in the gastric bypass group) and did not meet criteria for equivalence. Complete or partial remission of type 2 diabetes was seen in 37% (n = 15/41) after sleeve gastrectomy and in 45% (n = 18/40) after gastric bypass (P > .99). Medication for dyslipidemia was discontinued in 47% (n = 14/30) after sleeve gastrectomy and 60% (n = 24/40) after gastric bypass (P = .15) and for hypertension in 29% (n = 20/68) and 51% (n = 37/73) (P = .02), respectively. There was no statistically significant difference in QOL between groups (P = .85) and no treatment-related mortality. At 5 years the overall morbidity rate was 19% (n = 23) for sleeve gastrectomy and 26% (n = 31) for gastric bypass (P = .19). Among patients with morbid obesity, use of laparoscopic sleeve gastrectomy compared with use of laparoscopic Roux-en-Y gastric bypass did not meet criteria for equivalence in terms of percentage excess weight loss at 5 years. Although gastric bypass compared with sleeve gastrectomy was associated with greater percentage excess weight loss at 5 years, the difference was not statistically significant, based on the prespecified equivalence margins. clinicaltrials.gov Identifier: NCT00793143.

Structural basis of clade-specific HIV-1 neutralization by humanized anti-V3 monoclonal antibody KD-247.

PubMed

Kirby, Karen A; Ong, Yee Tsuey; Hachiya, Atsuko; Laughlin, Thomas G; Chiang, Leslie A; Pan, Yun; Moran, Jennifer L; Marchand, Bruno; Singh, Kamalendra; Gallazzi, Fabio; Quinn, Thomas P; Yoshimura, Kazuhisa; Murakami, Toshio; Matsushita, Shuzo; Sarafianos, Stefan G

2015-01-01

Humanized monoclonal antibody KD-247 targets the Gly(312)-Pro(313)-Gly(314)-Arg(315) arch of the third hypervariable (V3) loop of the HIV-1 surface glycoprotein. It potently neutralizes many HIV-1 clade B isolates, but not of other clades. To understand the molecular basis of this specificity, we solved a high-resolution (1.55 Å) crystal structure of the KD-247 antigen binding fragment and examined the potential interactions with various V3 loop targets. Unlike most antibodies, KD-247 appears to interact with its target primarily through light chain residues. Several of these interactions involve Arg(315) of the V3 loop. To evaluate the role of light chain residues in the recognition of the V3 loop, we generated 20 variants of KD-247 single-chain variable fragments with mutations in the antigen-binding site. Purified proteins were assessed for V3 loop binding using AlphaScreen technology and for HIV-1 neutralization. Our data revealed that recognition of the clade-specificity defining residue Arg(315) of the V3 loop is based on a network of interactions that involve Tyr(L32), Tyr(L92), and Asn(L27d) that directly interact with Arg(315), thus elucidating the molecular interactions of KD-247 with its V3 loop target. © FASEB.

Reconstruction Options for Pancreaticoduodenectomy in Patients with Prior Roux-en-Y Gastric Bypass.

PubMed

Shah, Mihir M; Martin, Benjamin M; Stetler, Jamil L; Patel, Ankit D; Davis, S Scott; Sarmiento, Juan M; Lin, Edward

2017-11-01

Patients with prior Roux-en-Y gastric bypass (RYGB) operations for weight loss present reconstruction challenges during a pancreaticoduodenectomy (PD). With over 60,000 RYGB performed annually, the increasing odds of encountering such patients during a PD make it imperative to understand the RYGB anatomy and anticipate reconstruction options. This article describes the possible reconstruction options and their rationale. We reviewed our PD reconstruction options, compared them to what have been described in the literature, and derived a consensus from internal conferences comprising bariatric and hepatopancreatobiliary surgeons to describe known reconstruction options. In general, reconstruction options can include one of three options: (1) remnant gastrectomy, (2) preservation of gastric remnant, or (3) reversal of gastric bypass. This article describes individualized reconstruction options for RYGB patients undergoing PD. The reconstruction options can be tailored to the needs of the patient.

Pancrelipase treatment in a patient with the history of Roux-en-Y gastric bypass operation that developed resistant hypocalcemia secondary to total thyroidectomy.

PubMed

Baldane, S; Ipekci, S H; Kebapcilar, L

2016-01-01

Roux-en-Y gastric bypass (RYGB) is an independent risk factor for moderate hypocalcaemia and may lead to the development of resistant hypocalcaemia following thyroid surgery. Subject and Results. A 35-year old female patient was referred to our hospital by her family physician for treatment of resistant hypocalcaemia. The patient underwent RYGB three years ago and a total thyroidectomy for a benign thyroid nodule one year ago. Calcitriol, calcium carbonate, magnesium oxide, and ergocalciferol therapeutic dosages were incremented. Despite dosage increments, the desired calcium levels were not achieved. In the sixth month after admission to our hospital, pancrelipase was added to patient's treatment scheme. On the following visit, a good calcium increase had been achieved. This report presents a case history of RYGB and resistant hypocalcaemia, which developed after thyroid surgery and positively responded to pancrelipase treatment.

Effect of proximal vagotomy and Roux-en-Y diversion on gastric emptying kinetics in asymptomatic patients.

PubMed

Urbain, J L; Penninckx, F; Siegel, J A; Vandenborre, P; Van Cutsem, E; Vandenmaegdenbergh, V; De Roo, M

1990-10-01

The role of the distal stomach in gastric emptying was studied. Ten patients with proximal gastric vagotomy (PV) and 10 age-matched patients with Roux-en-Y gastro-jejunostomy (R-Y) were compared with 10 healthy controls. Gastric emptying of solids and liquids was determined by the use of Tc-99m SC scrambled eggs and In-111 DTPA. In PV, gastric emptying of both solids and liquids was delayed; the prolongation with solids was mainly accounted for by an abnormal lag phase. In R-Y patients, no lag phase was observed, and the solid emptying curve pattern was characterized by early rapid emptying followed by very slow emptying. Both the solid and liquid phases were prolonged. The lag phase is affected by proximal vagotomy and is mainly determined by the distal stomach, which appears to be essential for normal emptying.

The Sleeping Remnant. Effect of Roux-En-Y Gastric Bypass on Plasma Levels of Gastric Biomarkers in Morbidly Obese Women: A Prospective Longitudinal Study.

PubMed

Marchesi, Federico; Tartamella, Francesco; De Sario, Giuseppina; Forlini, Clarissa; Caleffi, Alberta; Riccò, Matteo; Di Mario, Francesco

2017-07-01

Morpho-functional modifications of the gastric remnant after Roux-en-Y gastric bypass (RYGB) have not been completely defined, due to its inaccessibility for bioptic mapping. The aim of the study is to evaluate such modifications using Gastropanel®, a non-invasive blood test cross-checking four gastric biomarkers, able to provide a snapshot of mucosa conditions. Twenty-four women undergoing RYGB were prospectively enrolled. Gastropanel® parameters (pepsinogens, Gastrin-17 and immunoglobulins against Helicobacter pylori), biometrical/clinical data were collected preoperatively and at 6-months follow-up. All parameters showed significant reduction (p < 0.05). Pepsinogen I reduction correlated with BMI percent decrease. The exclusion of food transit is responsible for significant drop in gastric output, hardly representing a risk factor in the remnant carcinogenesis, being unexposed to alimentary carcinogenic agents.

Calcium oxalate crystal related kidney injury in a patient receiving Roux-en Y hepaticojejunostomy due to gall bladder cancer.

PubMed

Tsai, Jun-Li; Tsai, Shang-Feng

2017-03-29

Calcium oxalate nephropathy is rare in current practice. It was a common complication during jejunoileal bypass, but much less seen in modern gastric bypass surgery for morbid obesity. The major cause of it is enteric hyperoxaluria. We report on a patient here with acute kidney disease due to calcium oxalate nephropathy, rather than the conditions mentioned above. The male patient received a Roux-en Y hepaticojejunostomy and common bile duct drainage. In addition to enteric hyperoxaluria, chronic kidney disease related metabolic acidosis, chronic diarrhea related volume depletion, a high oxalate and low potassium diet, long term ascorbic acid intake and long term exposure to antibiotics, all predisposed him to having oxalate nephropathy. This is the first case with such conditions and we recommend that similarly diagnosed patients avoid all these predisposing factors, in order to avoid this rare disease and its undesired outcome.

Physiological adaptations following Roux-en-Y gastric bypass and the identification of targets for bariatric mimetic pharmacotherapy.

PubMed

Docherty, Neil G; Le Roux, Carel W

2015-12-01

The present opinion article provides an overview of the key improvements in metabolic and cardiovascular health following Roux-en-Y Gastric Bypass (RYGB). Some clinically important long-term complications of RYGB are also briefly described to contextualise the potential value of finding selective non-surgical means of replicating only the beneficial aspects of RYGB. Three biological responses linked to changes in gastrointestinal tract structure and function post-RYGB, that are implicated in the clinical efficacy of RYGB and that have actual or potential applications as non-surgical mimetic based approaches are addressed. These are (1) exaggerated post-prandial gut hormone responses; (2) local increases in undiluted bile in the gut lumen and augmented circulating bile acid and FGF19 concentrations and (3) compositional changes in the gut microbiota. Copyright © 2015 Elsevier Ltd. All rights reserved.

Giant perforated marginal ulcer after laparoscopic Roux-en-Y gastric bypass.

PubMed

Wang, Edward; Blackham, Ruth; Tan, Jeremy; Hamdorf, Jeffrey

2017-04-11

Perforation of a marginal ulcer (MU) is a complication of Roux -en-Y gastric bypass that can be life-threatening. We report a case of a perforated MU that presented 7 months after surgery with several interesting points for discussion. Firstly, the presentation of the ulcer was cryptic with unreliable investigations. Secondly, the ulcer presented again even after anastomotic revision surgery. Finally, the ulcer and the sepsis associated with perforation presented after months of poor nutritional intake with profound hypoalbuminaemia. Perforated MUs causing malnutrition pose clinicians with the difficult decision of which operation to offer; patch repair, revision of the anastomosis or reversal surgery. This case illustrates that primary reversal surgery for a perforated recurrent MU may be the most appropriate surgical management in this clinical situation. © BMJ Publishing Group Ltd (unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

The use of silastic transhepatic stents in benign and malignant biliary strictures.

PubMed Central

Cameron, J L; Gayler, B W; Zuidema, G D

1978-01-01

Between 1969 and 1978, 45 patients with biliary strictures have been managed surgically utilizing silastic transhepatic stents. In 25 patients the strictures were benign. After resection or dilatation of the benign stricture, an hepaticojejunostomy was performed to a Roux-en-Y loop. The anastomosis was stented with a large bore silastic tube with multiple side holes passed through the biliary tree, out the anterior surface of the liver, and then out through the abdominal wall. There was one hospital death. Most stents were left in place for one year. Of the 15 patients with long-term follow-up, all have had excellent results. In 20 patients the strictures were malignant and involved the common hepatic duct in 10 patients or its bifuraction in 10 patients. In 14 patients the tumor was thought to be primary in the biliary tree, and in six patients the tumor was felt to represent a metastasis or direct extension from another site. In three patients the tumors were resected, and in the remaining they were dilated or bypassed. After positioning a silastic transhepatic stent, a hepaticojejunostomy was carried out. There were two hospital deaths. Serum bilirubin on admission average 17.1 mg%, and after decompression 1.8 mg%. Five patients have survived over one year, and two over two years. Postoperative radiotherapy and a primary biliary tumor favored longer survival. Images Fig. 1. Fig. 2. Fig. 4. PMID:697437

High temperature annealing of ion irradiated tungsten

DOE PAGES

Ferroni, Francesco; Yi, Xiaoou; Arakawa, Kazuto; ...

2015-03-21

In this study, transmission electron microscopy of high temperature annealing of pure tungsten irradiated by self-ions was conducted to elucidate microstructural and defect evolution in temperature ranges relevant to fusion reactor applications (500–1200°C). Bulk isochronal and isothermal annealing of ion irradiated pure tungsten (2 MeV W + ions, 500°C, 1014 W +/cm 2) with temperatures of 800, 950, 1100 and 1400°C, from 0.5 to 8 h, was followed by ex situ characterization of defect size, number density, Burgers vector and nature. Loops with diameters larger than 2–3 nm were considered for detailed analysis, among which all loops had View themore » MathML source and were predominantly of interstitial nature. In situ annealing experiments from 300 up to 1200°C were also carried out, including dynamic temperature ramp-ups. These confirmed an acceleration of loop loss above 900°C. At different temperatures within this range, dislocations exhibited behaviour such as initial isolated loop hopping followed by large-scale rearrangements into loop chains, coalescence and finally line–loop interactions and widespread absorption by free-surfaces at increasing temperatures. An activation energy for the annealing of dislocation length was obtained, finding E a=1.34±0.2 eV for the 700–1100°C range.« less

Molecular determinants of the V3 loop of human immunodeficiency virus type 1 glycoprotein gp120 responsible for controlling cell tropism.

PubMed

Chavda, S C; Griffin, P; Han-Liu, Z; Keys, B; Vekony, M A; Cann, A J

1994-11-01

We and others have identified the major determinant of cell tropism in human immunodeficiency virus type 1 (HIV-1) as the V3 loop of glycoprotein gp120. We have conducted a detailed study of two molecularly cloned isolates of HIV-1, HIVJR-CSF and HIVNL4-3, that differ in their tropism for immortalized CD4+ cell lines, by constructing a series of site-directed mutations within the V3 loop of HIVJR-CSF based on the sequence of HIVNL4-3. The phenotypes of these mutants fall into two classes, those which are viable and those which are not. A spontaneous mutant with significantly altered growth properties was also recovered and found to have an additional single amino acid change in the V3 loop sequence. The carboxy-terminal beta-strand part of the V3 loop is the major determinant of cell tropism. However, the results presented here indicate that the functional role of the V3 loop sequences can only be interpreted properly in the context of the original gp120 backbone from which they were derived. These findings show that over-simplistic interpretation of sequence data derived from unknown mixtures of HIV variants in infected persons may be highly misleading.

Identification of Bacillus thuringiensis Cry3Aa toxin domain II loop 1 as the binding site of Tenebrio molitor cadherin repeat CR12.

PubMed

Zúñiga-Navarrete, Fernando; Gómez, Isabel; Peña, Guadalupe; Amaro, Itzel; Ortíz, Ernesto; Becerril, Baltazar; Ibarra, Jorge E; Bravo, Alejandra; Soberón, Mario

2015-04-01

Bacillus thuringiensis Cry toxins exert their toxic effect by specific recognition of larval midgut proteins leading to oligomerization of the toxin, membrane insertion and pore formation. The exposed domain II loop regions of Cry toxins have been shown to be involved in receptor binding. Insect cadherins have shown to be functionally involved in toxin binding facilitating toxin oligomerization. Here, we isolated a VHH (VHHA5) antibody by phage display that binds Cry3Aa loop 1 and competed with the binding of Cry3Aa to Tenebrio molitor brush border membranes. VHHA5 also competed with the binding of Cry3Aa to a cadherin fragment (CR12) that was previously shown to be involved in binding and toxicity of Cry3Aa, indicating that Cry3Aa binds CR12 through domain II loop 1. Moreover, we show that a loop 1 mutant, previously characterized to have increased toxicity to T. molitor, displayed a correlative enhanced binding affinity to T. molitor CR12 and to VHHA5. These results show that Cry3Aa domain II loop 1 is a binding site of CR12 T. molitor cadherin. Copyright © 2015 Elsevier Ltd. All rights reserved.

Transumbilical laparoscopic Roux-en-Y gastric bypass with hand-sewn gastrojejunal anastomosis.

PubMed

Fernández, José Ignacio; Ovalle, Cristian; Farias, Carlos; de la Maza, Jaime; Cabrera, Carolina

2013-01-01

Single-port laparoscopic surgery has undergone significant development over the past 5 years. Single port is used in various procedures, including bariatric surgery. The aim of this paper is to describe a surgical technique for gastric bypass with a transumbilical approach (transumbilical gastric bypass-TUGB) with hand-sewn gastrojejunostomy, in selected patients who may be benefited by a better cosmetic result. The procedure begins with a transumbilical vertical incision. We use the GelPOINT single-port device and a 5-mm assistant trocar in the left flank (in the first two cases, a 2-mm subxiphoid liver retractor was used). A gastric pouch is made and calibrated with a 36-Fr bougie. The gastrojejunal anastomosis is performed by hand-sewing in two layers. A Roux-en-Y with a biliary limb of 50 cm and an alimentary limb of 120 cm is performed with a stapler. Three women were subjected to TUGB. The women were aged 28, 31, and 42 years; they had body mass indexes of 40.3, 33, and 38.2; and the operating times were 150, 200, and 150 min, respectively. The first two women underwent a Roux-en-Y gastric bypass (RYGB), and the last woman underwent a RYGB with a resection of the stomach remnant. There were no conversions to open or multitrocar techniques. No complications or deaths occurred. The three patients were satisfied with the cosmetic result. The technique described for TUGB is a feasible procedure for surgeons who have previous experience with the transumbilical approach.

Physical Fitness and Body Composition Two Years after Roux-En-Y Gastric Bypass in Adolescents.

PubMed

Brissman, Markus; Ekbom, Kerstin; Hagman, Emilia; Mårild, Staffan; Gronowitz, Eva; Flodmark, Carl-Erik; Olbers, Torsten; Marcus, Claude

2017-02-01

We have previously shown promising results 2 years after Roux-en-Y gastric bypass surgery, within the Adolescence Morbid Obesity Surgery study (AMOS). The aim of the current study was to describe the 2-year outcome in cardiorespiratory fitness, body composition, and functional capacity in the Stockholm subset of the AMOS study. Forty-one adolescents (10 male, 31 female, age 14-18 years, body mass index 35-69 kg·m -2 ) were included. In addition to anthropometric measurements, participants performed a submaximal bicycle test, 6-min walk test, dual-energy X-ray absorptiometry, and a short interview at baseline, 1 and 2 years after surgery. Relative improvements in maximal oxygen consumption (VO 2 max) per kilogram body mass (+62 %) and per kilogram fat-free mass (+21 %), as well as walking distance (+13 %) were observed after 1 year, and persisted 2 years after surgery. Despite a reduction of fat-free mass (-15 %), absolute VO 2 max was maintained across the full group (+8 %, p = ns) and significantly increased in non-smokers. Body mass and fat mass were significantly decreased (-45.4 and -33.3 kg, respectively). Self-reported physical activity was significantly increased, and pain associated with movement was reduced. In adolescents with obesity, Roux-en-Y gastric bypass improved VO 2 max more than could be explained by fat mass loss alone. In combination with improved functional capacity and body composition, these results suggest that surgery in adolescence might add specific benefits of importance for future health.

Revision with Totally Hand-Sewn Gastrojejunostomy and Vagotomy for Refractory Marginal Ulcer after Laparoscopic Roux-en-Y Gastric Bypass.

PubMed

Chang, Po-Chih; Huang, Chih-Kun; Rajan, Mahendra; Hsin, Ming-Che

2016-05-01

Marginal ulcer is not infrequent after laparoscopic Roux-en-Y gastric bypass and could result in undesirable complications, such as intractability, bleeding, or perforation. Those patients who failed medical therapy, regarded as refractory marginal ulcers, may be considered as candidates for revisional surgery. Herein, we make a video presentation of a laparoscopic revisional procedure for refractory marginal ulcer. A 29-year-old morbidly obese woman (initial body mass index 37.1 kg/m(2)), a non-smoker, presented with persistent epigastric pain 3 months after initial laparoscopic Roux-en-Y gastric bypass at another institution. After an exhaustive work-up there, only the gastroendoscopy revealed a marginal ulcer and she underwent medical treatment (proton pump inhibitor and sucralfate) for 3 months, but the patient's symptom aggravated and the serial gastroendoscopies still confirmed the marginal ulcer without obvious resolution after a total of 4 months proton pump inhibitor therapy, suggesting failure of medical treatment and intractability. Laparoscopic revisional procedure with totally hand-sewn gastrojejunostomy and vagotomy was performed to relieve her intractable condition. The procedure took 130 min, without any intra-operative complications. Blood loss was 80 mL. The patient had an uneventful postoperative course, and the postoperative hospital stay was 3 days. She was relieved of her symptoms after this revisional surgery, and a subsequent gastroendoscopy 15 months later showed no marginal ulcers. Though long-term follow-up is needed to draw a definite conclusion, totally hand-sewn gastrojejunostomy and vagotomy remains a practicable revisional procedure to relieve refractory marginal ulcers.

The contribution of malabsorption to the reduction in net energy absorption after long-limb Roux-en-Y gastric bypass.

PubMed

Odstrcil, Elizabeth A; Martinez, Juan G; Santa Ana, Carol A; Xue, Beiqi; Schneider, Reva E; Steffer, Karen J; Porter, Jack L; Asplin, John; Kuhn, Joseph A; Fordtran, John S

2010-10-01

Roux-en-Y gastric bypass (RYGB) restricts food intake, and when the Roux limb is elongated to 150 cm, the procedure is believed to induce malabsorption. Our objective was to measure total reduction in intestinal absorption of combustible energy after RYGB and the extent to which this was due to restriction of food intake or malabsorption of ingested macronutrients. Long-limb RYGB was performed in 9 severely obese patients. Dietary intake and intestinal absorption of fat, protein, carbohydrate, and combustible energy were measured before and at 2 intervals after bypass. By using coefficients of absorption to measure absorptive function, equations were developed to calculate the daily gram and kilocalorie quantities of ingested macronutrients that were not absorbed because of malabsorption or restricted food intake. Coefficients of fat absorption were 92 ± 1.3% before bypass, 72 ± 5.5% 5 mo after bypass, and 68 ± 8.7% 14 mo after bypass. There were no statistically significant effects of RYGB on protein or carbohydrate absorption coefficients, although protein coefficients decreased substantially in some patients. Five months after bypass, malabsorption reduced absorption of combustible energy by 124 ± 57 kcal/d, whereas restriction of food intake reduced energy absorption by 2062 ± 271 kcal/d. Fourteen months after bypass, malabsorption reduced energy absorption by 172 ± 60 kcal/d compared with 1418 ± 171 kcal/d caused by restricted food intake. On average, malabsorption accounted for ≈6% and 11% of the total reduction in combustible energy absorption at 5 and 14 mo, respectively, after this gastric bypass procedure.

Factors associated with complications or failure of endoscopic balloon dilation of anastomotic stricture secondary to Roux-en-Y gastric bypass surgery.

PubMed

de Moura, Eduardo G H; Orso, Ivan R B; Aurélio, Eduardo F; de Moura, Eduardo T H; de Moura, Diogo T H; Santo, Marco A

2016-01-01

Roux-en-Y gastric bypass is a commonly used technique of bariatric surgery. One of the most important complications is gastrojejunal anastomotic stricture. Endoscopic balloon dilation appears to be well tolerated and effective, but well-designed randomized, controlled trials have not yet been conducted. Identify factors associated with complications or failure of endoscopic balloon dilation of anastomotic stricture secondary to Roux-en-Y gastric bypass surgery. Gastrointestinal endoscopy service, university hospital, Brazil. The records of 64 patients with anastomotic stricture submitted to endoscopic dilation with hydrostatic balloon dilation were reviewed. Information was collected on gastric pouch length, anastomosis diameter before dilation, number of dilation sessions, balloon diameter at each session, anastomosis diameter after the last dilation session, presence of postsurgical complications, endoscopic complications, and outcome of dilation. Comparisons were made among postsurgical and endoscopic complications; number of dilations, balloon diameter; anastomosis diameter before dilation; and dilation outcome. Success of dilation treatment was 95%. Perforation was positively and significantly associated with the number of dilation sessions (P = .03). Highly significant associations were found between ischemic segment and perforation (P<.001) and between ischemic segment and bleeding (P = .047). Ischemic segment (P = .02) and fistula (P = .032) were also associated with dilation failure. Ischemic segment and fistula were found to be important risk factors for balloon dilation failure. The greater the number of dilation sessions, the greater the number of endoscopic complications. Copyright © 2016 American Society for Metabolic and Bariatric Surgery. Published by Elsevier Inc. All rights reserved.

Technique and outcomes of laparoscopic-combined linear stapler and hand-sutured side-to-side esophagojejunostomy with Roux-en-Y reconstruction as a treatment modality in patients undergoing proximal gastrectomy for benign and malignant disease of the gastroesophageal junction.

PubMed

Esquivel, Carlos M; Ampudia, Carolina; Fridman, Abraham; Moon, Rena; Szomstein, Samuel; Rosenthal, Raul J

2014-02-01

Circular stapler and hand-sutured esophagojejunostomy has been the most popular technique utilized in patients undergoing proximal gastrectomy through Roux-en-Y reconstruction for disease processes of the gastroesophageal junction. In recent years, with the advent of laparoscopic bariatric surgical techniques and refined linear stapler cutters, surgeons have developed the linear stapler side-to-side technique as a valid option. The aim of this study is to describe our technique and review the outcomes using the Roux-en-Y reconstruction with linear staplers after laparoscopic proximal gastrectomy for malignant and benign disease. After Internal Review Board approval and with adherence to the Health Insurance Portability and Accountability Act guidelines, a retrospective review of a prospectively collected database was conducted. A total of 14 patients underwent proximal laparoscopic gastric resection at our institution during a 3-year period from January 2008 to January 2011. Sex, body mass index, prior surgeries, complications of the prior surgery, intraoperative complications, pathologic findings, postoperative complications, hospital stay, and outpatient follow-up were measured in the preoperative and postoperative period. Our patient population consisted of 9 women and 5 men, with a mean age and body mass index of 45.42 years and 35.64 kg/m, respectively. Indications for proximal gastrectomy was in 4 patients a leak at the angle of His secondary to sleeve gastrectomy for morbid obesity, 1 patient was a stricture after a vertical banded gastroplasty, 1 patient a revision of a eroded gastric band, 1 patient a revision of a eroded mesh secondary to a hiatal hernia repair, 1 patient a conversion of a failed Nissen, 3 patients had a total gastrectomy due to a stage 2 gastric cancer, and 1 patient a gastrointestinal stromal tumor. There were no intraoperative complications. All the procedures were completed laparoscopically. The mean operative time was 137.16 minutes. The mean hospital stay was 7.6 days. One patient had a postoperative stricture at the esophagojejunal anastomosis that required multiple dilatations. All patients with gastric cancer are free of tumor recurrence. The use of a laparoscopic proximal gastrectomy with Roux-en-Y reconstruction through combined side-to-side linear stapler and hand-sewn esophagojejunal anastomosis seems to be a feasible and safe approach.

Analysis of new isolates reveals new genome organization and a hypervariable region in infectious myonecrosis virus (IMNV).

PubMed

Dantas, Márcia Danielle A; Chavante, Suely F; Teixeira, Dárlio Inácio A; Lima, João Paulo M S; Lanza, Daniel C F

2015-05-04

Infectious myonecrosis virus (IMNV) has been the cause of many losses in shrimp farming since 2002, when the first myonecrosis outbreak was reported at Brazilian's northeast coast. Two additional genomes of Brazilian IMNV isolates collected in 2009 and 2013 were sequenced and analyzed in the present study. The sequencing revealed extra 643 bp and 22 bp, at 5' and 3' ends of IMNV genome respectively, confirming that its actual size is at least 8226 bp long. Considering these additional sequences in genome extremities, ORF1 can starts at nt 470, encoding a 1708 aa polyprotein. Computational predictions reveal two stem loops and two pseudoknots in the 5' end and a putative stem loop and a slippery motif located at 3' end, indicating that these regions can be involved in the start and termination of translation. Through a careful phylogenetic analysis, a higher genetic variability among Brazilian isolates could be observed, comparing with Indonesian IMNV isolates. It was also observed that the most variable region of IMNV genome is located in the first half of ORF1, coinciding with a region which probably encodes the capsid protrusions. The results presented here are a starting point to elucidate the viral's translational regulation and the mechanisms involved in virulence. Copyright © 2015 Elsevier B.V. All rights reserved.

Management of pancreatic trauma.

PubMed Central

Jones, R C

1978-01-01

Since 1950, 300 patients sustaining pancreatic injuries have been managed. Three-fourths of the injuries were due to penetrating trauma with a 20% mortality and one-fourth due to blunt trauma resulting in an 18% mortality. The pancreatic injury was responsible for death in only 3% of patients. Early onset of shock resulted in 38% mortality whereas only 4% of normotensive patients died. No patient died of an isolated pancreatic injury. Sepsis was the second most common cause of death following hemorrhage. Preoperative serum amylase was elevated more frequently following blunt trauma than penetrating trauma, but did not correlate with injury. There has been a tendency toward more frequent use of distal pancreatectomy for simple penetrating injuries without obvious ductal violation which increases operative time, blood loss and possible intra-abdominal abscess since resection usually requires splenectomy. Patients considered for an 80% distal resection are better managed with a Roux-en-Y limb to the distal pancreas since three patients developed diabetes following an 80% or greater resection. A conservative approach consisting of Penrose and sump drainage is adequate for most injuries. PMID:646495

Long-term (11+years) outcomes in weight, patient satisfaction, comorbidities, and gastroesophageal reflux treatment after laparoscopic sleeve gastrectomy.

PubMed

Arman, Gustavo A; Himpens, Jacques; Dhaenens, Jeroen; Ballet, Thierry; Vilallonga, Ramon; Leman, Guido

2016-12-01

More than 10 years of outcomes for sleeve gastrectomy (LSG) have not yet been documented. Analysis of>11 years of outcomes of isolated LSG in terms of progression of weight, patient satisfaction, and evolution of co-morbidities and gastroesophageal reflux disease (GERD) treatment. Two European private hospitals. Chart review and personal interview in consecutive patients who underwent primary isolated LSG (2001-2003). Of the 110 consecutive patients, complete follow-up data was available in 65 (59.1%). Mean follow-up was 11.7±.4 years. Two patients had died of non-procedure-related causes. Twenty (31.7%) patients required 21 reoperations: 14 conversions (10 duodenal switch (DS), 4 Roux-en-Y gastric bypass (RYGB), and 3 resleeve procedures) for weight issues and 2 conversions (RYGB), and 2 hiatoplasties for gastroesophageal reflux disease (GERD). For the 47 (74.6%) individuals who thus kept the simple sleeve construction, percentage of excess body mass index loss (%EBMIL) at 11+years was 62.5%, versus 81.7% (P = .015) for the 16 patients who underwent conversion to another construction. Mean %EBMIL for the entire cohort was 67.4%. At 11+years postoperatively, 30 patients versus 28 preoperatively required treatment for co-morbidities. None of the 7 patients preoperatively suffering from GERD were cured by the LSG procedure. Nine additional patients developed de novo GERD. Overall satisfaction rate was 8 (interquartile range 2) on a scale of 0-10. Isolated LSG provides a long-term %EBMIL of 62.5%. Conversion to another construction, required in 25% of the cases, provides a %EBMIL of 81.7% (P = .015). Patient satisfaction score remains good despite unfavorable GERD outcomes. Copyright © 2016 American Society for Bariatric Surgery. Published by Elsevier Inc. All rights reserved.

One-loop matching and running with covariant derivative expansion

DOE PAGES

Henning, Brian; Lu, Xiaochuan; Murayama, Hitoshi

2018-01-24

We develop tools for performing effective field theory (EFT) calculations in a manifestly gauge-covariant fashion. We clarify how functional methods account for one-loop diagrams resulting from the exchange of both heavy and light fields, as some confusion has recently arisen in the literature. To efficiently evaluate functional traces containing these “mixed” one-loop terms, we develop a new covariant derivative expansion (CDE) technique that is capable of evaluating a much wider class of traces than previous methods. The technique is detailed in an appendix, so that it can be read independently from the rest of this work. We review the well-knownmore » matching procedure to one-loop order with functional methods. What we add to this story is showing how to isolate one-loop terms coming from diagrams involving only heavy propagators from diagrams with mixed heavy and light propagators. This is done using a non-local effective action, which physically connects to the notion of “integrating out” heavy fields. Lastly, we show how to use a CDE to do running analyses in EFTs, i.e. to obtain the anomalous dimension matrix. We demonstrate the methodologies by several explicit example calculations.« less

Solution structure of an ATP-binding RNA aptamer reveals a novel fold.

PubMed Central

Dieckmann, T; Suzuki, E; Nakamura, G K; Feigon, J

1996-01-01

In vitro selection has been used to isolate several RNA aptamers that bind specifically to biological cofactors. A well-characterized example in the ATP-binding RNA aptamer family, which contains a conserved 11-base loop opposite a bulged G and flanked by regions of double-stranded RNA. The nucleotides in the consensus sequence provide a binding pocket for ATP (or AMP), which binds with a Kd in the micromolar range. Here we present the three-dimensional solution structure of a 36-nucleotide ATP-binding RNA aptamer complexed with AMP, determined from NMR-derived distance and dihedral angle restraints. The conserved loop and bulged G form a novel compact, folded structure around the AMP. The backbone tracing of the loop nucleotides can be described by a Greek zeta (zeta). Consecutive loop nucleotides G, A, A form a U-turn at the bottom of the zeta, and interact with the AMP to form a structure similar to a GNRA tetraloop, with AMP standing in for the final A. Two asymmetric G. G base pairs close the stems flanking the internal loop. Mutated aptamers support the existence of the tertiary interactions within the consensus nucleotides and with the AMP found in the calculated structures. PMID:8756406

One-loop matching and running with covariant derivative expansion

DOE Office of Scientific and Technical Information (OSTI.GOV)

Henning, Brian; Lu, Xiaochuan; Murayama, Hitoshi

We develop tools for performing effective field theory (EFT) calculations in a manifestly gauge-covariant fashion. We clarify how functional methods account for one-loop diagrams resulting from the exchange of both heavy and light fields, as some confusion has recently arisen in the literature. To efficiently evaluate functional traces containing these “mixed” one-loop terms, we develop a new covariant derivative expansion (CDE) technique that is capable of evaluating a much wider class of traces than previous methods. The technique is detailed in an appendix, so that it can be read independently from the rest of this work. We review the well-knownmore » matching procedure to one-loop order with functional methods. What we add to this story is showing how to isolate one-loop terms coming from diagrams involving only heavy propagators from diagrams with mixed heavy and light propagators. This is done using a non-local effective action, which physically connects to the notion of “integrating out” heavy fields. Lastly, we show how to use a CDE to do running analyses in EFTs, i.e. to obtain the anomalous dimension matrix. We demonstrate the methodologies by several explicit example calculations.« less

One-loop matching and running with covariant derivative expansion

NASA Astrophysics Data System (ADS)

Henning, Brian; Lu, Xiaochuan; Murayama, Hitoshi

2018-01-01

We develop tools for performing effective field theory (EFT) calculations in a manifestly gauge-covariant fashion. We clarify how functional methods account for one-loop diagrams resulting from the exchange of both heavy and light fields, as some confusion has recently arisen in the literature. To efficiently evaluate functional traces containing these "mixed" one-loop terms, we develop a new covariant derivative expansion (CDE) technique that is capable of evaluating a much wider class of traces than previous methods. The technique is detailed in an appendix, so that it can be read independently from the rest of this work. We review the well-known matching procedure to one-loop order with functional methods. What we add to this story is showing how to isolate one-loop terms coming from diagrams involving only heavy propagators from diagrams with mixed heavy and light propagators. This is done using a non-local effective action, which physically connects to the notion of "integrating out" heavy fields. Lastly, we show how to use a CDE to do running analyses in EFTs, i.e. to obtain the anomalous dimension matrix. We demonstrate the methodologies by several explicit example calculations.

Synthesis and evaluation of phase detectors for active bit synchronizers

NASA Technical Reports Server (NTRS)

Mcbride, A. L.

1974-01-01

Self-synchronizing digital data communication systems usually use active or phase-locked loop (PLL) bit synchronizers. The three main elements of PLL synchronizers are the phase detector, loop filter, and the voltage controlled oscillator. Of these three elements, phase detector synthesis is the main source of difficulty, particularly when the received signals are demodulated square-wave signals. A phase detector synthesis technique is reviewed that provides a physically realizable design for bit synchronizer phase detectors. The development is based upon nonlinear recursive estimation methods. The phase detector portion of the algorithm is isolated and analyzed.

Flavor-singlet baryons in the graded symmetry approach to partially quenched QCD

NASA Astrophysics Data System (ADS)

Hall, Jonathan M. M.; Leinweber, Derek B.

2016-11-01

Progress in the calculation of the electromagnetic properties of baryon excitations in lattice QCD presents new challenges in the determination of sea-quark loop contributions to matrix elements. A reliable estimation of the sea-quark loop contributions represents a pressing issue in the accurate comparison of lattice QCD results with experiment. In this article, an extension of the graded symmetry approach to partially quenched QCD is presented, which builds on previous theory by explicitly including flavor-singlet baryons in its construction. The formalism takes into account the interactions among both octet and singlet baryons, octet mesons, and their ghost counterparts; the latter enables the isolation of the quark-flow disconnected sea-quark loop contributions. The introduction of flavor-singlet states enables systematic studies of the internal structure of Λ -baryon excitations in lattice QCD, including the topical Λ (1405 ).

Rapid detection of newly isolated Tembusu-related Flavivirus by reverse-transcription loop-mediated isothermal amplification assay

PubMed Central

2011-01-01

Background From April 2010 to January 2011, a severe new viral disease had devastated most duck-farming regions in China. This disease affected not only laying ducks but also meat ducks, causing huge economic losses for the poultry industry. The objective of this study is to develop a one-step reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay for the detection of the new virus related to Tembusu-related Flavivirus. Results The RT-LAMP assay is very simple and rapid, and the amplification can be completed within 50 min under isothermal conditions at 63°C by a set of 6 primers targeting the E gene based on the sequences analysis of the newly isolated viruses and other closely related Flavivirus.The monitoring of gene amplification can also be visualized by using SYBR green I fluorescent dye. In addition, the RT-LAMP assay for newly isolated Tembusu-related Flavivirus showed higher sensitivity with an RNA detection-limit of 2 copies/μL compared with 190 copies/μL of the conventional RT-PCR method. The specificity was identified without cross reaction to other common avian pathogens. By screening a panel of clinical samples this method was more feasible in clinical settings and there was higher positive coincidence rate than conventional RT-PCR and virus isolation. Conclusion The RT-LAMP assay for newly isolated Tembusu-related Flavivirus is a valuable tool for the rapid and real-time detection not only in well-equipped laboratories but also in general conditions. PMID:22185513

Simple, rapid and sensitive detection of Orientia tsutsugamushi by loop-isothermal DNA amplification.

PubMed

Paris, Daniel H; Blacksell, Stuart D; Newton, Paul N; Day, Nicholas P J

2008-12-01

We present a loop-mediated isothermal PCR assay (LAMP) targeting the groEL gene, which encodes the 60kDa heat shock protein of Orientia tsutsugamushi. Evaluation included testing of 63 samples of contemporary in vitro isolates, buffy coats and whole blood samples from patients with fever. Detection limits for LAMP were assessed by serial dilutions and quantitation by real-time PCR assay based on the same target gene: three copies/microl for linearized plasmids, 26 copies/microl for VERO cell culture isolates, 14 copies/microl for full blood samples and 41 copies/microl for clinical buffy coats. Based on a limited sample number, the LAMP assay is comparable in sensitivity with conventional nested PCR (56kDa gene), with limits of detection well below the range of known admission bacterial loads of patients with scrub typhus. This inexpensive method requires no sophisticated equipment or sample preparation, and may prove useful as a diagnostic assay in financially poor settings; however, it requires further prospective validation in the field setting.

Bovine tuberculosis research: Immune mechanisms relevant to biomedical applications

USDA-ARS?s Scientific Manuscript database

Pioneer studies on infectious disease and immunology by Jenner, Pasteur, Koch, Von Behring, Nocard, Roux, and Ehrlich forged a path for the dual-purpose with dual benefit approach, clearly demonstrating the relevance of veterinary studies for biomedical applications. Tuberculosis (TB), primarily due...

Backbone dynamics of the antifungal Psd1 pea defensin and its correlation with membrane interaction by NMR spectroscopy.

PubMed

de Medeiros, Luciano Neves; Angeli, Renata; Sarzedas, Carolina G; Barreto-Bergter, Eliana; Valente, Ana Paula; Kurtenbach, Eleonora; Almeida, Fabio C L

2010-02-01

Plant defensins are cysteine-rich cationic peptides, components of the innate immune system. The antifungal sensitivity of certain exemplars was correlated to the level of complex glycosphingolipids in the membrane of fungi strains. Psd1 is a 46 amino acid residue defensin isolated from pea seeds which exhibit antifungal activity. Its structure is characterized by the so-called cysteine-stabilized alpha/beta motif linked by three loops as determined by two-dimensional NMR. In the present work we explored the measurement of heteronuclear Nuclear Overhauser Effects, R1 and R2 (15)N relaxation ratios, and chemical shift to probe the backbone dynamics of Psd1 and its interaction with membrane mimetic systems with phosphatidylcholine (PC) or dodecylphosphocholine (DPC) with glucosylceramide (CMH) isolated from Fusarium solani. The calculated R2 values predicted a slow motion around the highly conserved among Gly12 residue and also in the region of the Turn3 His36-Trp38. The results showed that Psd1 interacts with vesicles of PC or PC:CMH in slightly different forms. The interaction was monitored by chemical shift perturbation and relaxation properties. Using this approach we could map the loops as the binding site of Psd1 with the membrane. The major binding epitope showed conformation exchange properties in the mus-ms timescale supporting the conformation selection as the binding mechanism. Moreover, the peptide corresponding to part of Loop1 (pepLoop1: Gly12 to Ser19) is also able to interact with DPC micelles acquiring a stable structure and in the presence of DPC:CMH the peptide changes to an extended conformation, exhibiting NOE mainly with the carbohydrate and ceramide parts of CMH. Copyright 2009 Elsevier B.V. All rights reserved.

In vitro optimization of truncated stem-loop II variants of the hammerhead ribozyme for cleavage in low concentrations of magnesium under non-turnover conditions.

PubMed Central

Zillmann, M; Limauro, S E; Goodchild, J

1997-01-01

By truncating helix II to two base pairs in a hammerhead ribozyme having long flanking sequences (greater than 30 bases), the rate of cleavage in 1 mM magnesium can be increased roughly 100-fold. Replacing most of the nucleotides in a typical stem-loop II with 1-4 randomized nucleotides gave an RNA library that, even before selection, was more active in 1 mM magnesium than the parent ribozyme, but considerably less active than the truncated stem-loop II ribozyme. A novel, multiround selection for intermolecular cleavage was exploited to optimize this library for cleavage in low concentrations of magnesium. After three rounds of selection at sequentially lower concentrations of magnesium, the library cleaved substrate RNA 20-fold faster than the initial pool and was cloned. This pool was heavily enriched for one particular sequence (5'-CGUG-3') that represented 16 of 52 isolates (the next most common sequence was represented only six times). This sequence also represented the most active sequence, exceeding the activity of the short helix II variant under the conditions of the selection, thereby demonstrating the effectiveness of the selection technique. Analysis of the cleavage rates of RNAs made from eight isolates having different four-base insert sequences allowed assignment of highly preferred bases at each position in the insert. Analysis of pool clones having insert of differing lengths showed that, in general, activity decreased as the length of the insert decreased from 4 to 1. This supports the suggested role of stem-loop II in stabilizing the non-Watson-Crick interactions between the conserved bases of the catalytic core. PMID:9214657

Percentage of excess BMI lost correlates better with improvement of metabolic syndrome after Roux-en-Y gastric bypass in morbidly obese subjects: anthropometric indexes and gastric bypass.

PubMed

Rossi, Marçal; Serpa Neto, Ary; Rossi, Felipe Martin Bianco; Amarante, Rodrigo Dal Moro; Alcântara, Geraldo Chaves; da Silva, Renato Barretto Ferreira; Regina, Paulo Fernando

2009-01-01

The metabolic syndrome (MS) is a complex disorder characterized by a number of cardiovascular risk factors usually associated with central fat deposition and insulin resistance. Many different medical treatments are available for MS, including bariatric surgery, which improves all risk factors. The present study aimed to evaluate, at the Clinic of Gastroenterology and Obesity Surgery (Brazil), the accuracy of different anthropometric indexes and their correlation with improvement of the MS factors in the postoperative (6-month) period. This was a retrospective study of 140 patients who had undergone gastric bypass. Most of the patients were women (79.3%). The mean body mass index was 44.17 kg/m(2). We evaluated the weight of the subjects, the presence of diabetes mellitus and hypertension as co-morbidities, and the biochemical parameters. The anthropometric indexes tested included the percentage of excess weight loss, amount lost in kilograms, difference in the body mass index, percentage of initial weight lost, percentage of excess body mass index lost (%EBL), and percentage of initial fat mass lost. The %EBL had a Spearman's correlation coefficient of 0.55 (P <.0001) for the difference between the MS factors before and after Roux-en-Y gastric bypass. The receiver operating characteristic curve for the %EBL resulted in an area under the curve of 0.846 (P = 0.0001) and a sensitivity and specificity of 100% and 61.29%, respectively, for a cutoff value of 64.55%. The %EBL was the best method to report weight loss and the improvement in MS in morbidly obese subjects after Roux-en-Y gastric bypass.

Open total gastrectomy with Roux-en-Y reconstruction for a chronic fistula after sleeve gastrectomy.

PubMed

Bruzzi, Matthieu; Douard, Richard; Voron, Thibault; Berger, Anne; Zinzindohoue, Franck; Chevallier, Jean-Marc

2016-12-01

Surgery appears to be the best treatment option for a chronic fistula after laparoscopic sleeve gastrectomy (LSG). Conservative procedures (conversion into a Roux-en-Y gastric bypass, Roux-limb placement) have proven their feasibility and efficacy, but an open total gastrectomy (TG) is sometimes required in challenging situations. To assess outcomes from 12 consecutive patients who underwent surgery for a post-sleeve gastrectomy chronic fistula (PSGCF) between January 2004 and February 2012. University public hospital, France. Patients with a PSGCF who underwent surgery were included in this retrospective study. Mortality, morbidity (i.e., Clavien-Dindo score), weight loss, and nutritional status were assessed. Twelve of 57 patients (21%) with a post-LSG leak developed a PSGCF. There were 3 men (25%). Mean age was 39±9 years and mean preoperative body mass index was 35±5 kg/m 2 . All 12 patients underwent an open total gastrectomy with an esojejunostomy (TG). Conservative procedures were considered but not possible. The mean follow-up period was 38±11 months. The mean delay between LSG and TG was 12±6 months. Intraoperative discovery of multiple (>2) gastric fistulas was reported in 9 patients (75%). There were no deaths, but morbidity rate was 50%. Early postoperative fistula occurred in 3 patients (anastomosis n = 1, duodenal stump n = 2). None of these patients required further surgery. The median healing time of the fistula was 37 days (range 24-53). Promising results from weight loss and nutritional status were found at the end of the follow-up. A salvage open TG is a well-tolerated and reproducible salvage procedure for cases of a PSGCF, when conservative procedures are not possible. Copyright © 2016 American Society for Bariatric Surgery. Published by Elsevier Inc. All rights reserved.

Older Age Confers a Higher Risk of 30-Day Morbidity and Mortality Following Laparoscopic Bariatric Surgery: an Analysis of the Metabolic and Bariatric Surgery Quality Improvement Program.

PubMed

Haskins, Ivy N; Ju, Tammy; Whitlock, Ashlyn E; Rivas, Lisbi; Amdur, Richard L; Lin, Paul P; Vaziri, Khashayar

2018-04-17

There is a paucity of literature describing the association of age with the risk of adverse events following bariatric surgery. The purpose of this study is to investigate the association of age with 30-day morbidity and mortality following laparoscopic bariatric surgery using the Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program (MBSAQIP) database. All adult patients undergoing laparoscopic Roux-en-Y gastric bypass (RNGYB) or sleeve gastrectomy (SG) were identified within the MBSAQIP database. Patients were divided into five equal age quintiles. Binary outcomes of interest, including cardiac, pulmonary, wound, septic, clotting, and renal events, in addition to the incidence of related 30-day unplanned reintervention, related 30-day mortality, and a composite morbidity and mortality outcome were compared across the age quintiles and procedures. A total of 266,544 patients met inclusion criteria. Older age was associated with an increased risk of all morbidity outcomes except venous thromboembolism events, 30-day mortality, and the composite morbidity and mortality outcome. Patients who underwent Roux-en-Y gastric bypass had worse outcomes per quintile for almost every outcome of interest when compared to patients who underwent sleeve gastrectomy. Older patients and patients who undergo Roux-en-Y gastric bypass are at an increased risk of perioperative morbidity and mortality following laparoscopic bariatric surgery. Additional studies are needed to determine the association of age with long-term weight loss and cardiometabolic comorbidity resolution following bariatric surgery in order to determine if the increased perioperative risk is offset by improved long-term outcomes in older patients undergoing bariatric surgery.

Dietary assessment of adolescents undergoing laparoscopic Roux-en-Y gastric bypass surgery: macro- and micronutrient, fiber, and supplement intake.

PubMed

Jeffreys, Renee M; Hrovat, Kathleen; Woo, Jessica G; Schmidt, Marcia; Inge, Thomas H; Xanthakos, Stavra A

2012-01-01

Extremely obese adolescents are increasingly undergoing bariatric procedures, which restrict dietary intake. However, as yet, no data are available describing the change in caloric density or composition of the adolescent bariatric patient's diet pre- and postoperatively. Our objective was to assess the 1-year change in the dietary composition of adolescents undergoing bariatric surgery at a tertiary care children's hospital. A total of 27 subjects (67% female, 77% white, age 16.7 ± 1.4 yr, baseline body mass index 60.1 ± 14.1 kg/m(2)) were prospectively enrolled into an observational cohort study 1 month before undergoing laparoscopic Roux-en-Y gastric bypass from August 2005 to March 2008. The 3-day dietary intake was recorded at baseline (n = 24) and 2 weeks (n = 16), 3 months (n = 11), and 1 year (n = 9) postoperatively. The dietary record data were verified by structured interview and compared with the Dietary Reference Intake values for ages 14-18 years. By 1 year after surgery, the mean caloric intake, adjusted for body mass index was 1015 ± 182 kcal/d, a 35% reduction from baseline. The proportion of fat, protein, and carbohydrate intake did not differ from baseline. However, the protein intake was lower than recommended postoperatively. The calcium and fiber intake was also persistently lower than recommended. Calcium and vitamin B(12) supplementation increased the likelihood of meeting the daily minimal recommendations (P ≤ .02). At 1 year after Roux-en-Y gastric bypass, the adolescents' caloric intake remained restricted, with satisfactory macronutrient composition but a lower than desirable intake of calcium, fiber, and protein. Copyright © 2012 American Society for Metabolic and Bariatric Surgery. Published by Elsevier Inc. All rights reserved.

EUS-directed Transgastric ERCP (EDGE) Versus Laparoscopy-assisted ERCP (LA-ERCP) for Roux-en-Y Gastric Bypass (RYGB) Anatomy: A Multicenter Early Comparative Experience of Clinical Outcomes.

PubMed

Kedia, Prashant; Tarnasky, Paul R; Nieto, Jose; Steele, Stephen L; Siddiqui, Ali; Xu, Ming-Ming; Tyberg, Amy; Gaidhane, Monica; Kahaleh, Michel

2018-04-17

The standard of care for managing pancreaticobiliary disease in altered Roux-en-Y gastric bypass patients is laparoscopy-assisted endoscopic retrograde cholangiopancreatography (LA-ERCP), but is limited by cost and adverse events. Recently a minimally invasive, completely endoscopic approach using endoscopic ultrasound (EUS) directed transgastric ERCP (EDGE) has been described. We aim to compare EDGE to LA-ERCP in this study. Patients from May 2005 to June 2017 with Roux-en-Y gastric bypass anatomy having undergone LA-ERCP or EDGE at 4 tertiary centers were captured in a registry. Patient demographics, procedural details, and clinical outcomes were measured for each group. Seventy-two patients (n=29 EDGE, n=43 LA-ERCP) were included in this study. There was no significant difference in the technical success of EDGE gastrogastric fistula (96.5%) versus LA-gastrostomy creation (100%). The success rate of achieving therapeutic ERCP (EDGE 96.5% vs. LA-ERCP 97.7%) and number of ERCP (EDGE 1.2 vs. LA-ERCP 1.02) needed to achieve clinical resolution was similar between both groups. Adverse event rate for EDGE, 24% (7/29) and LA-ERCP, 19% (8/43) was similar. The total procedure time (73 vs. 184 min) and length of hospital stay (0.8 vs. 2.65 d) was significantly shorter for EDGE compared to LA-ERCP. The overall weight change after EDGE was -6.6 lbs at an average 28-week follow-up. This study suggests that the EDGE procedure has similar technical success and adverse events compared with LA-ERCP with the benefit of significantly shorter procedure times and hospital stay. EDGE may offer a minimally invasive, effective option, with less resource utilization, and without significant weight gain.

The incidence and risk factors associated with developing symptoms of hypoglycemia after bariatric surgery.

PubMed

Lee, Clare J; Brown, Todd T; Schweitzer, Michael; Magnuson, Thomas; Clark, Jeanne M

2018-06-01

Hypoglycemia after bariatric surgery is an increasingly recognized metabolic complication associated with exaggerated secretion of insulin and gut hormones. We sought to determine the incidence of hypoglycemic symptoms (hypo-sx) after bariatric surgery and characteristics of those affected compared with those unaffected. University hospital. We collected retrospective survey data from the patients who underwent bariatric surgery at a single center. Based on number and severity of postprandial hypo-sx in Edinburgh hypoglycemia questionnaire postoperatively, patients without preoperative hypo-sx were grouped into high versus low suspicion for hypoglycemia. We used multivariable logistic regression to examine potential baseline and operative risk factors for the development of hypo-sx after surgery. Among the 1119 patients who had undergone bariatric surgery who received the questionnaire, 464 (40.6%) responded. Among the 341 respondents without preexisting hypo-sx, 29% (n = 99) had new-onset hypo-sx, and most were severe cases (n = 92) with neuroglycopenic symptoms. Compared with the low suspicion group, the high suspicion group consisted of more female patients, younger patients, patients without diabetes, and those who underwent Roux-en-Y gastric bypass with a longer time since surgery and more weight loss. In multivariate analysis, factors independently associated with incidence of hypo-sx after bariatric surgery were female sex (P = .003), Roux-en-Y gastric bypass (P = .001), and absence of preexisting diabetes (P = .011). New onset postprandial hypoglycemic symptoms after bariatric surgery are common, affecting up to a third of those who underwent bariatric surgery. Many affected individuals reported neuroglycopenic symptoms and were more likely to be female and nondiabetic and to have undergone Roux-en-Y gastric bypass. Copyright © 2018 American Society for Bariatric Surgery. Published by Elsevier Inc. All rights reserved.

Roux-en-Y gastric bypass reversal: a systematic review.

PubMed

Shoar, Saeed; Nguyen, Thu; Ona, Mel A; Reddy, Madhavi; Anand, Sury; Alkuwari, Mohammed J; Saber, Alan A

2016-08-01

Due to the large number of Roux-en-Y gastric bypass surgeries performed over the last decade, reversal of the bypass to normal anatomy has been increasingly reported. University affiliated Teaching Hospital, United States. The aim of this systematic review was to summarize the literature data regarding the indications, technical considerations, and outcomes of gastric bypass reversal. PubMed/MEDLINE search was conducted for articles reporting reversal of gastric bypass to normal anatomy. Patients' demographic characteristics, primary reason for reversal, reversal technique, and postreversal events were retrieved and categorized from each eligible paper. Thirty-five articles encompassing a total of 100 patients were eligible. Malnutrition was the most common indication for reversal (12.3%), followed by severe dumping syndrome (9.4%), postprandial hypoglycemia (8.5%), and excessive weight loss (8.5%). Techniques for gastrogastrostomy were available in 42 patients, with the hand-sewn technique as the most common (67.4%) followed by the linear stapler (23.2%) and the end-to-end anastomosis stapler used in 3 patients (6.9%). The reversal technique was performed endoscopically and described in 3 studies (3 patients). Techniques for handling the Roux limb were described in 56 patients (56%); the limb was reconnected in 32 patients (57.2%) and resected in 24 patients (42.8%). Weight regain was the most prevalent postreversal event (28.8%), followed by severe gastroesophageal reflux diseases (10.2%) and persistent abdominal pain (6.8%). There was no reported mortality. Gastric bypass reversal is indicated for excessive weight loss, dumping syndrome, and postprandial hypoglycemia. The procedure is well tolerated and feasible when performed laparoscopically and has no reported mortality. Copyright © 2016 American Society for Bariatric Surgery. Published by Elsevier Inc. All rights reserved.

Does Robotic Roux-en-Y Gastric Bypass Provide Outcome Advantages over Standard Laparoscopic Approaches?

PubMed

Rogula, Tomasz; Koprivanac, Marijan; Janik, Michał Robert; Petrosky, Jacob A; Nowacki, Amy S; Dombrowska, Agnieszka; Kroh, Matthew; Brethauer, Stacy; Aminian, Ali; Schauer, Philip

2018-04-10

The aim was to compare clinical outcomes of patients treated with totally robotic Roux-en-Y gastric bypass (TRRYGB) with those treated with the different laparoscopic Roux-en-Y gastric bypass (LRYGB) techniques. The clinical benefit of the robotic approach to bariatric surgery compared to the standard laparoscopic approach is unclear. There are no studies directly comparing outcomes of TRRYGB with different LRYGB techniques. Outcomes of 578 obese patients who underwent RYGB between 2011 and 2014 at an academic center were assessed. Multivariable analysis and propensity matching were used for comparing TRRYGB to different LRYGB techniques, including 21-mm EEA circular-stapled gastrojejunal anastomosis (GJA, LRYGB-21CS), linear-stapled GJA (LRYGB-LS), and hand-sewn GJA (LRYGB-HS). The TRRYGB technique required a longer mean operative time compared to the other groups, respectively 204 ± 46 vs. 139 ± 30 min (LRYGB-21CS), 206 ± 37 vs. 158 ± 30 min (LRYGB-LS), and 210 ± 36 vs. 167 ± 30 min (LRYGB-HS). TRRYGB experienced a lower stricture rate (2 vs. 17%, P = 0.003), shorter hospital stay (2.6 ± 1.2 vs. 4.3 ± 5.5 days, P = 0.008), and lower readmission rate (12 vs. 28%, P = 0.009). No significant differences in outcomes were observed when comparing RRYGB to LRYGB-LS or LRYGB-HS. TRRYGB increases operative time compared to all LRYGB techniques. TRRYGB was superior to LRYGB-21CS in terms of significantly shorter hospital stay, lower readmission rate, and less frequent GJA stricture formation. TRRYGB provides no clinical advantages over the LRYGB-LS and LRYGB-HS techniques.

Correlates of Dietary Adherence and Maladaptive Eating Patterns Following Roux-en-Y Bariatric Surgery.

PubMed

Adler, Sarah; Fowler, Natasha; Robinson, Athena Hagler; Salcido, Lianne; Darcy, Alison; Toyama, Hannah; Safer, Debra Lynn

2018-04-01

Self-reported poor dietary adherence following bariatric surgery is associated with less successful weight loss outcomes. Poor dietary adherence is a global construct lacking specificity regarding its underlying, clinically targetable, maladaptive eating behaviors. Comprehensive online survey data were obtained from a sample of 274 adults who underwent Roux-en-Y surgery in the prior 1-12 years. Correlations between dietary adherence and six eating-related behaviors were calculated, with the frequency of each behavior reported on a 7-point scale. Linear regression modeling was applied. All six maladaptive eating behaviors were highly correlated with dietary adherence (Pearson's r > 0.5): grazing (r = - 0.565), mindless eating (r = - 0.572), loss of control eating (r = - 0.517), eating "more than is best" after dinner (r = - 0.518), eating foods off of one's plan (r = - 0.557), and "when I eat something off-plan, I feel like I have blown it and I give up and eat more" (r = - 0.574). The estimated regression coefficients in the linear model was statistically significant, [F(5, 261) = 60.006, p < 0.001] and accounted for approximately 54% of the variance of global dietary adherence (R 2  = 0.535, adjusted R 2  = 0.526). Six maladaptive eating behaviors accounted for a highly significant portion of post-Roux-en-Y patients' poor self- reported dietary adherence. Prospective studies are needed to investigate the relationship between targetable maladaptive eating behaviors and bariatric surgery outcomes.

Endoluminal Revision (OverStitch (TM) , Apollo Endosurgery) of the Dilated Gastroenterostomy in Patients with Late Dumping Syndrome After Proximal Roux-en-Y Gastric Bypass.

PubMed

Stier, Christine; Chiappetta, Sonja

2016-08-01

Dumping syndrome is a long-term postoperative complication of Roux-en-Y gastric bypass procedures. Morphologically, dumping syndrome usually correlates with a dilatation of the gastroenterostomy with accelerated pouch emptying. Conservative therapy includes diet changes, complementary pharmacotherapy and, if symptoms persist, surgical revision. Surgical options include endoscopic, endoluminal surgery to constrict the gastrojejunostomy using a novel endoscopic suturing device (OverStitch(TM), Apollo). In our study, we aimed to assess the viability, safety and efficacy of this procedure in patients with late dumping; 14 patients who had developed late dumping syndrome underwent surgery using an endoscopic suturing technique (OverStitch(TM), Apollo). Late dumping was confirmed by Sigstad score and an oral glucose tolerance test (OGTT). Prior to surgery, objective analysis of pouch emptying speed was assessed by gastric scintigraphy. Surgery was performed under general anaesthesia. None of the 14 patients suffered intra- or postoperative complications. No postsurgical increase in inflammation parameters was observed. The postinterventional pain scale (visual analogue scale) showed a mean score of 0.5 (range 0-10). In 13 of the 14 patients, no dumping was observed 1-month postsurgery. The postoperative Sigstad score (3.07 ± 2.06; range 1-9) showed an impressive reduction compared with the preoperative score (12.71 ± 4.18; range 7-24) (p < 0.001). Postoperative upper gastrointestinal gastrografin swallow revealed regular emptying in all the patients. The endoluminal endoscopic suturing technique-applied here for surgical revision of gastroenterostomy following Roux-en-Y gastric bypass-represents a promising, novel therapeutic option in late dumping syndrome involving minimal trauma and offering rapid reconvalescence.

Application of Roll-Isolated Inertial Measurement Units to the Instrumentation of Spinning Vehicles

DOE Office of Scientific and Technical Information (OSTI.GOV)

BEADER,MARK E.

Roll-isolated inertial measurement units are developed at Sandia for use in the instrumentation, guidance, and control of rapidly spinning vehicles. Roll-isolation is accomplished by supporting the inertial instrument cluster (gyros and accelerometers) on a single gimbal, the axis of which is parallel to the vehicle's spin axis. A rotary motor on the gimbal is driven by a servo loop to null the roll gyro output, thus inertially stabilizing the gimbal and instrument cluster while the vehicle spins around it. Roll-isolation prevents saturation of the roll gyro by the high vehicle spin rate, and vastly reduces measurement errors arising from gyromore » scale factor and alignment uncertainties. Nine versions of Sandia-developed roll-isolated inertial measurement units have been flown on a total of 27 flight tests since 1972.« less

Ni2+-binding RNA motifs with an asymmetric purine-rich internal loop and a G-A base pair.

PubMed Central

Hofmann, H P; Limmer, S; Hornung, V; Sprinzl, M

1997-01-01

RNA molecules with high affinity for immobilized Ni2+ were isolated from an RNA pool with 50 randomized positions by in vitro selection-amplification. The selected RNAs preferentially bind Ni2+ and Co2+ over other cations from first series transition metals. Conserved structure motifs, comprising about 15 nt, were identified that are likely to represent the Ni2+ binding sites. Two conserved motifs contain an asymmetric purine-rich internal loop and probably a mismatch G-A base pair. The structure of one of these motifs was studied with proton NMR spectroscopy and formation of the G-A pair at the junction of helix and internal loop was demonstrated. Using Ni2+ as a paramagnetic probe, a divalent metal ion binding site near this G-A base pair was identified. Ni2+ ions bound to this motif exert a specific stabilization effect. We propose that small asymmetric purine-rich loops that contain a G-A interaction may represent a divalent metal ion binding site in RNA. PMID:9409620

["Cholethorax" revealing injury to the common bile duct after celioscopic cholecystectomy].

PubMed

Lehur, P A; Guiberteau-Canfrère, V; Bury, A; Cloarec, D; Le Borgne, J

1992-01-01

The case-report describes the unusual formation of a bilious pleural effusion or "cholethorax" revealing a common bile duct injury secondary to laparoscopic cholecystectomy. Pleural drainage led to a diagnostic ERCP. Subsequently a Roux en Y hepatico-jejunostomy allowed a satisfactory outcome.

Internal hernia in late pregnancy after laparoscopic Roux-en-Y gastric bypass.

PubMed

Gruetter, Florian; Kraljević, Marko; Nebiker, Christian A; Delko, Tarik

2014-12-23

A 27-year-old patient in late pregnancy presented to the department of obstetrics with crampy abdominal pain located in the right flank, 3 years after a laparoscopic Roux-en-Y gastric bypass. Clinical investigation showed tenderness on palpation in the upper abdomen without signs of peritonitis. The cardiotocogram and blood tests were normal. The ultrasound showed a hydronephrosis on the right side, and a pigtail catheter was inserted. The abdominal symptoms did not abate and the abdominal surgeon was consulted 36 hours after admission. Diagnostic laparoscopy was performed promptly because of high suspicion of internal hernia (IH). Laparoscopy showed IH at the mesojejunal intermesenteric defect with a herniated common channel and volvulus of the anastomosis. Conversion to open reduction and complete closure with non-absorbable interrupted sutures was performed. Small bowel resection was avoided. The patient was discharged 10 days after the operation and a healthy boy was born 4 weeks later. 2014 BMJ Publishing Group Ltd.

Duct-to-duct biliary reconstruction after radical resection of Bismuth IIIa hilar cholangiocarcinoma.

PubMed

Wu, Wen-Guang; Gu, Jun; Dong, Ping; Lu, Jian-Hua; Li, Mao-Lan; Wu, Xiang-Song; Yang, Jia-Hua; Zhang, Lin; Ding, Qi-Chen; Weng, Hao; Ding, Qian; Liu, Ying-Bin

2013-04-21

At present, radical resection remains the only effective treatment for patients with hilar cholangiocarcinoma. The surgical approach for R0 resection of hilar cholangiocarcinoma is complex and diverse, but for the biliary reconstruction after resection, almost all surgeons use Roux-en-Y hepaticojejunostomy. A viable alternative to Roux-en-Y reconstruction after radical resection of hilar cholangiocarcinoma has not yet been proposed. We report a case of performing duct-to-duct biliary reconstruction after radical resection of Bismuth IIIa hilar cholangiocarcinoma. End-to-end anastomosis between the left hepatic duct and the distal common bile duct was used for the biliary reconstruction, and a single-layer continuous suture was performed along the bile duct using 5-0 prolene. The patient was discharged favorably without biliary fistula 2 wk later. Evidence for tumor recurrence was not found after an 18 mo follow-up. Performing bile duct end-to-end anastomosis in hilar cholangiocarcinoma can simplify the complex digestive tract reconstruction process.

Surgical Models of Roux-en-Y Gastric Bypass Surgery and Sleeve Gastrectomy in Rats and Mice

PubMed Central

Bruinsma, Bote G.; Uygun, Korkut; Yarmush, Martin L.; Saeidi, Nima

2015-01-01

Bariatric surgery is the only definitive solution currently available for the present obesity pandemic. These operations typically involve reconfiguration of gastrointestinal tract anatomy and impose profound metabolic and physiological benefits, such as substantially reducing body weight and ameliorating type II diabetes. Therefore, animal models of these surgeries offer unique and exciting opportunities to delineate the underlying mechanisms that contribute to the resolution of obesity and diabetes. Here we describe a standardized procedure for mouse and rat models of Roux-en-Y gastric bypass (80–90 minutes operative time) and sleeve gastrectomy (30–45 minutes operative time), which, to a high degree resemble operations in human. We also provide detailed protocols for both pre- and post-operative techniques that ensure a high success rate in the operations. These protocols provide the opportunity to mechanistically investigate the systemic effects of the surgical interventions, such as regulation of body weight, glucose homeostasis, and gut microbiome. PMID:25719268

Cystic Dilation of Extrahepatic Bile Ducts in Adulthood: Diagnosis, Surgical Treatment and Long. Term Results

PubMed Central

Rotondano, G.; D'Agostino, A.; Iannelli, A.; Marano, I.; Santangelo, M. L.

1998-01-01

To evaluate the long-term results of surgery for choledohal cyst in adulthood, a series of 13 patients over the age of 16 operated on for choledochal cyst during a period of six years and followed-up for a minimum of 3 years was analyzed. Patients with type I and IVa cysts underwent extrahepatic cyst resection and Roux-en-Y hepatico-jejunostomy. Choledochoceles (type III) were managed endoscopically. No operative mortality or morbidity occurred. Type I and III cysts showed almost ideal follow-up with no sign of stricture on HIDA scan. One type IVa cyst patients developed recurrent cholangitis due to anastomotic stricture, managed percutaneously. Whenever possible, complete cyst resection and Roux-en-Y reconstruction is the treatment of choice for all extrahepatic biliary cysts. Intra- and extrahepatic dilatations are adequately treated by extrahepatic resection and careful endoscopic or radiologic surveillance. Small choledochoceles can be safely managed by endoscopic sphincterotomy. PMID:9515236

Altered ghrelin secretion in mice in response to diet-induced obesity and Roux-en-Y gastric bypass

PubMed Central

Uchida, Aki; Zechner, Juliet F.; Mani, Bharath K.; Park, Won-mee; Aguirre, Vincent; Zigman, Jeffrey M.

2014-01-01

The current study examined potential mechanisms for altered circulating ghrelin levels observed in diet-induced obesity (DIO) and following weight loss resulting from Roux-en-Y gastric bypass (RYGB). We hypothesized that circulating ghrelin levels were altered in obesity and after weight loss through changes in ghrelin cell responsiveness to physiological cues. We confirmed lower ghrelin levels in DIO mice and demonstrated elevated ghrelin levels in mice 6 weeks post-RYGB. In both DIO and RYGB settings, these changes in ghrelin levels were associated with altered ghrelin cell responsiveness to two key physiological modulators of ghrelin secretion – glucose and norepinephrine. In DIO mice, increases in ghrelin cell density within both the stomach and duodenum and in somatostatin-immunoreactive D cell density in the duodenum were observed. Our findings provide new insights into the regulation of ghrelin secretion and its relation to circulating ghrelin within the contexts of obesity and weight loss. PMID:25353000

A Theory for Self-consistent Acceleration of Energetic Charged Particles by Dynamic Small-scale Flux Ropes

NASA Astrophysics Data System (ADS)

le Roux, J. A.; Zank, G. P.; Khabarova, O.; Webb, G. M.

2016-12-01

Simulations of charged particle acceleration in turbulent plasma regions with numerous small-scale contracting and merging (reconnecting) magnetic islands/flux ropes emphasize the key role of temporary particle trapping in these structures for efficient acceleration that can result in power-law spectra. In response, a comprehensive kinetic transport theory framework was developed by Zank et al. and le Roux et al. to capture the essential physics of energetic particle acceleration in solar wind regions containing numerous dynamic small-scale flux ropes. Examples of test particle solutions exhibiting hard power-law spectra for energetic particles were presented in recent publications by both Zank et al. and le Roux et al.. However, the considerable pressure in the accelerated particles suggests the need for expanding the kinetic transport theory to enable a self-consistent description of energy exchange between energetic particles and small-scale flux ropes. We plan to present the equations of an expanded kinetic transport theory framework that will enable such a self-consistent description.

Roux-en-Y Gastric Bypass and Vertical Banded Gastroplasty Induce Long-Term Changes on the Human Gut Microbiome Contributing to Fat Mass Regulation

PubMed Central

Tremaroli, Valentina; Karlsson, Fredrik; Werling, Malin; Ståhlman, Marcus; Kovatcheva-Datchary, Petia; Olbers, Torsten; Fändriks, Lars; le Roux, Carel W.; Nielsen, Jens; Bäckhed, Fredrik

2015-01-01

Summary Bariatric surgery is currently the most effective procedure for the treatment of obesity. Given the role of the gut microbiota in regulating host metabolism and adiposity, we investigated the long-term effects of bariatric surgery on the microbiome of patients randomized to Roux-en-Y gastric bypass or vertical banded gastroplasty and matched for weight and fat mass loss. The two surgical procedures induced similar and durable changes on the gut microbiome that were not dependent on body mass index and resulted in altered levels of fecal and circulating metabolites compared with obese controls. By colonizing germ-free mice with stools from the patients, we demonstrated that the surgically altered microbiota promoted reduced fat deposition in recipient mice. These mice also had a lower respiratory quotient, indicating decreased utilization of carbohydrates as fuel. Our results suggest that the gut microbiota may play a direct role in the reduction of adiposity observed after bariatric surgery. PMID:26244932

One-tube loop-mediated isothermal amplification combined with restriction endonuclease digestion and ELISA for colorimetric detection of resistance to isoniazid, ethambutol and streptomycin in Mycobacterium tuberculosis isolates.

PubMed

Lee, Mei-Feng; Chen, Yen-Hsu; Hsu, Hui-Jine; Peng, Chien-Fang

2010-10-01

In this study, we designed a simple and rapid colorimetric detection method, a one-tube loop-mediated isothermal amplification (LAMP)-PCR-hybridization-restriction endonuclease-ELISA [one-tube LAMP-PCR-HY-RE-ELISA] system, to detect resistance to isoniazid, ethambutol and streptomycin in strains of Mycobacterium tuberculosis isolated from clinical specimens. The clinical performance of this method for detecting isoniazid-resistant, ethambutol-resistant and streptomycin-resistant isolates of M. tuberculosis showed 98.9%, 94.3% and 93.8%, respectively. This assay is rapid and convenient that can be performed within one working day. One-tube LAMP-PCR-HY-RE-ELISA system was designed based on hot spot point mutations in target drug-resistant genes, using LAMP-PCR, hybridization, digestion with restriction endonuclease and colorimetric method of ELISA. In this study, LAMP assay was used to amplify DNA from drug-resistant M. tuberculosis, and ELISA was used for colorimetrical determination. This assay will be a useful tool for rapid diagnosis of mutant codons in strains of M. tuberculosis for isoniazid at katG 315 and katG 463, ethambutol at embB 306 and embB 497, and streptomycin at rpsL 43. Crown Copyright © 2010. Published by Elsevier B.V. All rights reserved.

Investigation on active vibration isolation of a Stewart platform with piezoelectric actuators

NASA Astrophysics Data System (ADS)

Wang, Chaoxin; Xie, Xiling; Chen, Yanhao; Zhang, Zhiyi

2016-11-01

A Stewart platform with piezoelectric actuators is presented for micro-vibration isolation. The Jacobi matrix of the Stewart platform, which reveals the relationship between the position/pointing of the payload and the extensions of the six struts, is derived by kinematic analysis. The dynamic model of the Stewart platform is established by the FRF (frequency response function) synthesis method. In the active control loop, the direct feedback of integrated forces is combined with the FxLMS based adaptive feedback to dampen vibration of inherent modes and suppress transmission of periodic vibrations. Numerical simulations were conducted to prove vibration isolation performance of the Stewart platform under random and periodical disturbances, respectively. In the experiment, the output consistencies of the six piezoelectric actuators were measured at first and the theoretical Jacobi matrix as well as the feedback gain of each piezoelectric actuator was subsequently modified according to the measured consistencies. The direct feedback loop was adjusted to achieve sufficient active damping and the FxLMS based adaptive feedback control was adopted to suppress vibration transmission in the six struts. Experimental results have demonstrated that the Stewart platform can achieve 30 dB attenuation of periodical disturbances and 10-20 dB attenuation of random disturbances in the frequency range of 5-200 Hz.

Performing Isoelectric Focusing and Simultaneous Fractionation of Proteins on A Rotary Valve Followed by Sodium Dodecyl – Polyacrylamide Gel Electrophoresis

PubMed Central

Wang, Wei; Lu, Joann J.; Gu, Congying; Zhou, Lei; Liu, Shaorong

2013-01-01

In this technical note, we design and fabricate a novel rotary valve and demonstrate its feasibility for performing isoelectric focusing and simultaneous fractionation of proteins, followed by sodium dodecyl – polyacrylamide gel electrophoresis. The valve has two positions. In one position, the valve routes a series of capillary loops together into a single capillary tube where capillary isoelectric focusing (CIEF) is performed. By switching the valve to another position, the CIEF-resolved proteins in all capillary loops are isolated simultaneously, and samples in the loops are removed and collected in vials. After the collected samples are briefly processed, they are separated via sodium dodecyl – polyacrylamide gel electrophoresis (SDS-PAGE, the 2nd-D separation) on either a capillary gel electrophoresis instrument or a slab-gel system. The detailed valve configuration is illustrated, and the experimental conditions and operation protocols are discussed. PMID:23819755

EVIDENCE FOR EVAPORATION-INCOMPLETE CONDENSATION CYCLES IN WARM SOLAR CORONAL LOOPS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Froment, C.; Auchère, F.; Bocchialini, K.

2015-07-10

Quasi-constant heating at the footpoints of loops leads to evaporation and condensation cycles of the plasma: thermal non-equilibrium (TNE). This phenomenon is believed to play a role in the formation of prominences and coronal rain. However, it is often discounted as being involved in the heating of warm loops because the models do not reproduce observations. Recent simulations have shown that these inconsistencies with observations may be due to oversimplifications of the geometries of the models. In addition, our recent observations reveal that long-period intensity pulsations (several hours) are common in solar coronal loops. These periods are consistent with thosemore » expected from TNE. The aim of this paper is to derive characteristic physical properties of the plasma for some of these events to test the potential role of TNE in loop heating. We analyzed three events in detail using the six EUV coronal channels of the Solar Dynamics Observatory/Atmospheric Imaging Assembly. We performed both a differential emission measure (DEM) and a time-lag analysis, including a new method to isolate the relevant signal from the foreground and background emission. For the three events, the DEM undergoes long-period pulsations, which is a signature of periodic heating even though the loops are captured in their cooling phase, as is the bulk of the active regions. We link long-period intensity pulsations to new signatures of loop heating with strong evidence for evaporation and condensation cycles. We thus simultaneously witness widespread cooling and TNE. Finally, we discuss the implications of our new observations for both static and impulsive heating models.« less

Heating mechanisms for intermittent loops in active region cores from AIA/SDO EUV observations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cadavid, A. C.; Lawrence, J. K.; Christian, D. J.

2014-11-01

We investigate intensity variations and energy deposition in five coronal loops in active region cores. These were selected for their strong variability in the AIA/SDO 94 Å intensity channel. We isolate the hot Fe XVIII and Fe XXI components of the 94 Å and 131 Å by modeling and subtracting the 'warm' contributions to the emission. HMI/SDO data allow us to focus on 'inter-moss' regions in the loops. The detailed evolution of the inter-moss intensity time series reveals loops that are impulsively heated in a mode compatible with a nanoflare storm, with a spike in the hot 131 Å signalsmore » leading and the other five EUV emission channels following in progressive cooling order. A sharp increase in electron temperature tends to follow closely after the hot 131 Å signal confirming the impulsive nature of the process. A cooler process of growing emission measure follows more slowly. The Fourier power spectra of the hot 131 Å signals, when averaged over the five loops, present three scaling regimes with break frequencies near 0.1 min{sup –1} and 0.7 min{sup –1}. The low frequency regime corresponds to 1/f noise; the intermediate indicates a persistent scaling process and the high frequencies show white noise. Very similar results are found for the energy dissipation in a 2D 'hybrid' shell model of loop magneto-turbulence, based on reduced magnetohydrodynamics, that is compatible with nanoflare statistics. We suggest that such turbulent dissipation is the energy source for our loops.« less

Looping tracks associated with tropical cyclones approaching an isolated mountain. Part I: Essential parameters

NASA Astrophysics Data System (ADS)

Huang, Yi-Chih; Lin, Yuh-Lang

2018-06-01

Essential parameters for making a looping track when a westward-moving tropical cyclone (TC) approaches a mesoscale mountain are investigated by examining several key nondimensional control parameters with a series of systematic, idealized numerical experiments, such as U/ Nh, V max/ Nh, U/ fL x , V max/ fR, h/ L x , and R/ L y . Here U is the uniform zonal wind velocity, N the Brunt-Vaisala frequency, h the mountain height, f the Coriolis parameter, V max the maximum tangential velocity at a radius of R from the cyclone center and L x is the halfwidth of the mountain in the east-west direction. It is found that looping tracks (a) tend to occur under small U/ Nh and U/ fL x , moderate h/ L x , and large V max/ Nh, which correspond to slow movement (leading to subgeostrophic flow associated with strong orographic blocking), moderate steepness, and strong tangential wind associated with TC vortex; (b) are often accompanied by an area of perturbation high pressure to the northeast of the mountain, which lasts for only a short period; and (c) do not require the existence of a northerly jet. The nondimensional control parameters are consolidated into a TC looping index (LI), {U2 R2 }/{V_{max 2 hLy }} , which is tested by several historical looping and non-looping typhoons approaching Taiwan's Central Mountain Range (CMR) from east or southeast. It is found that LI < 0.0125 may serve as a criterion for looping track to occur.

On the structure of solar and stellar coronae - Loops and loop heat transport

NASA Technical Reports Server (NTRS)

Litwin, Christof; Rosner, Robert

1993-01-01

We discuss the principal constraints on mechanisms for structuring and heating the outer atmospheres - the coronae - of stars. We argue that the essential cause of highly localized heating in the coronae of stars like the sun is the spatially intermittent nature of stellar surface magnetic fields, and that the spatial scale of the resulting coronal structures is related to the spatial structure of the photospheric fields. We show that significant constraints on coronal heating mechanisms derive from the observed variations in coronal emission, and, in addition, show that the observed structuring perpendicular to coronal magnetic fields imposes severe constraints on mechanisms for heat dispersal in the low-beta atmosphere. In particular, we find that most of commonly considered mechanisms for heat dispersal, such as anomalous diffusion due to plasma turbulence or magnetic field line stochasticity, are much too slow to account for the observed rapid heating of coronal loops. The most plausible mechanism appears to be reconnection at the interface between two adjacent coronal flux bundles. Based on a model invoking hyperresistivity, we show that such a mechanism naturally leads to dominance of isolated single bright coronal loops and to bright coronal plasma structures whose spatial scale transverse to the local magnetic field is comparable to observed dimensions of coronal X-ray loops.

Endo-β-D-1,4-mannanase from Chrysonilia sitophila displays a novel loop arrangement for substrate selectivity.

PubMed

Gonçalves, Ana Maria D; Silva, Catarina S; Madeira, Tânia I; Coelho, Ricardo; de Sanctis, Daniele; San Romão, Maria Vitória; Bento, Isabel

2012-11-01

The crystal structure of wild-type endo-β-D-1,4-mannanase (EC 3.2.1.78) from the ascomycete Chrysonilia sitophila (CsMan5) has been solved at 1.40 Å resolution. The enzyme isolated directly from the source shows mixed activity as both an endo-glucanase and an endo-mannanase. CsMan5 adopts the (β/α)(8)-barrel fold that is well conserved within the GH5 family and has highest sequence and structural homology to the GH5 endo-mannanases. Superimposition with proteins of this family shows a unique structural arrangement of three surface loops of CsMan5 that stretch over the active centre, promoting an altered topography of the binding cleft. The most relevant feature results from the repositioning of a long loop at the extremity of the binding cleft, resulting in a shortened glycone-binding region with two subsites. The other two extended loops flanking the binding groove produce a narrower cleft compared with the wide architecture observed in GH5 homologues. Two aglycone subsites (+1 and +2) are identified and a nonconserved tryptophan (Trp271) at the +1 subsite may offer steric hindrance. Taken together, these findings suggest that the discrimination of mannan substrates is achieved through modified loop length and structure.

Nuclear axial currents in chiral effective field theory

DOE PAGES

Baroni, Alessandro; Girlanda, Luca; Pastore, Saori; ...

2016-01-11

Two-nucleon axial charge and current operators are derived in chiral effective field theory up to one loop. The derivation is based on time-ordered perturbation theory and accounts for cancellations between the contributions of irreducible diagrams and the contributions owing to nonstatic corrections from energy denominators of reducible diagrams. Ultraviolet divergencies associated with the loop corrections are isolated in dimensional regularization. The resulting axial current is finite and conserved in the chiral limit, while the axial charge requires renormalization. As a result, a complete set of contact terms for the axial charge up to the relevant order in the power countingmore » is constructed.« less

Cyborg lectins: novel leguminous lectins with unique specificities.

PubMed

Yamamoto, K; Maruyama, I N; Osawa, T

2000-01-01

Bauhinia purpurea lectin (BPA) is one of the beta-galactose-binding leguminous lectins. Leguminous lectins contain a long metal-binding loop, part of which determines their carbohydrate-binding specificities. Random mutations were introduced into a portion of the cDNA coding BPA that corresponds to the carbohydrate-binding loop of the lectin. An library of the mutant lectin expressed on the surface of lambda foo phages was screened by the panning method. Several phage clones with an affinity for mannose or N-acetylglucosamine were isolated. These results indicate the possibility of making artificial lectins (so-called "cyborg lectins") with distinct and desired carbohydrate-binding specificities.

Closed-loop spontaneous baroreflex transfer function is inappropriate for system identification of neural arc but partly accurate for peripheral arc: predictability analysis

PubMed Central

Kamiya, Atsunori; Kawada, Toru; Shimizu, Shuji; Sugimachi, Masaru

2011-01-01

Abstract Although the dynamic characteristics of the baroreflex system have been described by baroreflex transfer functions obtained from open-loop analysis, the predictability of time-series output dynamics from input signals, which should confirm the accuracy of system identification, remains to be elucidated. Moreover, despite theoretical concerns over closed-loop system identification, the accuracy and the predictability of the closed-loop spontaneous baroreflex transfer function have not been evaluated compared with the open-loop transfer function. Using urethane and α-chloralose anaesthetized, vagotomized and aortic-denervated rabbits (n = 10), we identified open-loop baroreflex transfer functions by recording renal sympathetic nerve activity (SNA) while varying the vascularly isolated intracarotid sinus pressure (CSP) according to a binary random (white-noise) sequence (operating pressure ± 20 mmHg), and using a simplified equation to calculate closed-loop-spontaneous baroreflex transfer function while matching CSP with systemic arterial pressure (AP). Our results showed that the open-loop baroreflex transfer functions for the neural and peripheral arcs predicted the time-series SNA and AP outputs from measured CSP and SNA inputs, with r2 of 0.8 ± 0.1 and 0.8 ± 0.1, respectively. In contrast, the closed-loop-spontaneous baroreflex transfer function for the neural arc was markedly different from the open-loop transfer function (enhanced gain increase and a phase lead), and did not predict the time-series SNA dynamics (r2; 0.1 ± 0.1). However, the closed-loop-spontaneous baroreflex transfer function of the peripheral arc partially matched the open-loop transfer function in gain and phase functions, and had limited but reasonable predictability of the time-series AP dynamics (r2, 0.7 ± 0.1). A numerical simulation suggested that a noise predominantly in the neural arc under resting conditions might be a possible mechanism responsible for our findings. Furthermore, the predictabilities of the neural arc transfer functions obtained in open-loop and closed-loop conditions were validated by closed-loop pharmacological (phenylephrine and nitroprusside infusions) pressure interventions. Time-series SNA responses to drug-induced AP changes predicted by the open-loop transfer function matched closely the measured responses (r2, 0.9 ± 0.1), whereas SNA responses predicted by closed-loop-spontaneous transfer function deviated greatly and were the inverse of measured responses (r, −0.8 ± 0.2). These results indicate that although the spontaneous baroreflex transfer function obtained by closed-loop analysis has been believed to represent the neural arc function, it is inappropriate for system identification of the neural arc but is essentially appropriate for the peripheral arc under resting conditions, when compared with open-loop analysis. PMID:21486839

[Spontaneous perforation of the hepatic duct during biliary lithiasis complicated by acute pancreatitis].

PubMed

Assadourian, R; Chometowski, S; Bourde, J; Poitout, D; Lamy, J

1975-10-01

The association of perforation of the common bile duct, cholecystitis and acute pancreatitis, should be emphasized. Physiopathology of perforation of the bile duct may be compared with that of pancreatitis. Repair of the bile duct may be delicate requiring hepatico-jejunostomy on an isolated loop.

The Multi-Agent Tactical Sentry: Designing and Delivering Robots to the CF

DTIC Science & Technology

2008-08-01

believed that there is no substitute for having the man in the loop during military operations. After the World Trade Center and Tokyo subway attacks...and vibration isolation for the more sensitive components. Additional space was left to account for possible future changes to the primary sensors

Memoized Online Variational Inference for Dirichlet Process Mixture Models

DTIC Science & Technology

2014-06-27

breaking process [7], which places artifically large mass on the final component. It is more efficient and broadly applicable than an alternative trunction...models. In Uncertainty in Artificial Intelligence , 2008. [13] N. Le Roux, M. Schmidt, and F. Bach. A stochastic gradient method with an exponential

Bariatric surgery options.

PubMed

Woodward, Bryan G

2003-01-01

There are multiple surgical procedures used for weight loss. The concept of achieving malabsorption through manipulation of the gastrointestinal contract is briefly discussed. Various surgical options are considered with their advantages and disadvantages, namely vertical banded gastroplasty, gastric banding, Roux-en-y gastric bypass, distal gastric bypass billiopancreatic diversion, and duodental switch.

Energetic adaptations persist after bariatric surgery in severely obese adolescents

USDA-ARS?s Scientific Manuscript database

Energetic adaptations induced by bariatric surgery have not been studied in adolescents or for extended periods postsurgery. Energetic, metabolic, and neuroendocrine responses to Roux-en-Y gastric bypass (RYGB) surgery were investigated in extremely obese adolescents. At baseline and at 1.5, 6, and...

Upregulation of the PatAB Transporter Confers Fluoroquinolone Resistance to Streptococcus pseudopneumoniae

PubMed Central

Alvarado, María; Martín-Galiano, Antonio J.; Ferrándiz, María J.; Zaballos, Ángel; de la Campa, Adela G.

2017-01-01

We characterized the mechanism of fluoroquinolone-resistance in two isolates of Streptococcus pseudopneumoniae having fluoroquinolone-efflux as unique mechanism of resistance. Whole genome sequencing and genetic transformation experiments were performed together with phenotypic determinations of the efflux mechanism. The PatAB pump was identified as responsible for efflux of ciprofloxacin (MIC of 4 μg/ml), ethidium bromide (MICs of 8–16 μg/ml) and acriflavine (MICs of 4–8 μg/ml) in both isolates. These MICs were at least 8-fold lower in the presence of the efflux inhibitor reserpine. Complete genome sequencing indicated that the sequence located between the promoter of the patAB operon and the initiation codon of patA, which putatively forms an RNA stem-loop structure, may be responsible for the efflux phenotype. RT-qPCR determinations performed on RNAs of cultures treated or not treated with subinhibitory ciprofloxacin concentrations were performed. While no significant changes were observed in wild-type Streptococcus pneumoniae R6 strain, increases in transcription were detected in the ciprofloxacin-efflux transformants obtained with DNA from efflux-positive isolates, in the ranges of 1.4 to 3.4-fold (patA) and 2.1 to 2.9-fold (patB). Ciprofloxacin-induction was related with a lower predicted free energy for the stem-loop structure in the RNA of S. pseudopneumoniae isolates (−13.81 and −8.58) than for R6 (−15.32 kcal/mol), which may ease transcription. The presence of these regulatory variations in commensal S. pseudopneumoniae isolates, and the possibility of its transfer to Streptococcus pneumoniae by genetic transformation, could increase fluoroquinolone resistance in this important pathogen. PMID:29123510

Detection of Haemophilus parasuis isolates from South China by loop-mediated isothermal amplification and isolate characterisation.

PubMed

Zhang, Jian-Min; Shen, Hai-Yan; Liao, Ming; Ren, Tao; Guo, Li-Li; Xu, Cheng-Gang; Feng, Sai-Xiang; Fan, Hui-Ying; Li, Jing-Yi; Chen, Ji-Dang; Zhang, Bin

2012-04-24

Haemophilus parasuis is the etiological agent of Glässer's disease, which is characterised by fibrinous polyserositis, meningitis and polyarthritis, causing severe economic losses to the swine industry. In this study, a loop-mediated isothermal amplification (LAMP) test was developed to improve the specificity, facility and speed of diagnosis of H. parasuis isolates. The LAMP assay rapidly amplified the target gene within 50 min incubation at 63 °C in a laboratory water bath. The LAMP amplicon could be visualised directly in the reaction tubes following the addition of SYBR Green I dye. The detection limit of this LAMP method was 10 CFU/mL, which was 10 times more sensitive than the earlier 16S rRNA polymerase chain reaction (PCR) test conducted by Oliveira, Galina and Pijoan (2001), and no cross-reactivity was observed from other non-H. parasuis strains. This LAMP test was evaluated further on 187 clinical specimens from pigs suspected of being infected with H. parasuis. Forty-three were found positive by bacterial isolation of H. parasuis, as well as by the 16S rRNA PCR and LAMP tests. The 43 H. parasuis isolates were classified into 9 serovars and had 37 genetic patterns when analysed by pulsed-field gel electrophoresis (PFGE). This displayed that various H. parasuis serovars and genotypes were widely distributed in South China. Therefore, the speed, specificity and sensitivity of the LAMP test, the lack of a need for expensive equipment, and the visual readout showed great potential for a correct clinical diagnosis of H. parasuis in favour of controlling Glässer's disease.

Endoscopic placement of the small-bowel video capsule by using a capsule endoscope delivery device.

PubMed

Holden, Jeremy P; Dureja, Parul; Pfau, Patrick R; Schwartz, Darren C; Reichelderfer, Mark; Judd, Robert H; Danko, Istvan; Iyer, Lalitha V; Gopal, Deepak V

2007-05-01

Capsule endoscopy performed via the traditional peroral route is technically challenging in patients with dysphagia, gastroparesis, and/or abnormal upper-GI (UGI) anatomy. To describe the indications and outcomes of cases in which the AdvanCE capsule endoscope delivery device, which has recently been cleared by the Food and Drug Administration, was used. Retrospective, descriptive, case series. Tertiary care, university hospital. We report a case series of 16 consecutive patients in whom the AdvanCE delivery device was used. The study period was May 2005 through July 2006. Endoscopic delivery of the video capsule to the proximal small bowel by using the AdvanCE delivery device. Indications, technique, and completeness of small bowel imaging in patients who underwent endoscopic video capsule delivery. The AdvanCE delivery device was used in 16 patients ranging in age from 3 to 74 years. The primary indications for endoscopic delivery included inability to swallow the capsule (10), altered UGI anatomy (4), and gastroparesis (2). Of the 4 patients with altered UGI anatomy, 3 had dual intestinal loop anatomy (ie, Bilroth-II procedure, Whipple surgery, Roux-en-Y gastric bypass) and 1 had a failed Nissen fundoplication. In all cases, the capsule was easily deployed without complication, and complete small intestinal imaging was achieved. Small patient size. Endoscopic placement of the Given PillCam by use of the AdvanCE delivery device was safe and easily performed in patients for whom capsule endoscopy would otherwise have been contraindicated or technically challenging.

Microgravity Isolation Control System Design Via High-Order Sliding Mode Control

NASA Technical Reports Server (NTRS)

Shkolnikov, Ilya; Shtessel, Yuri; Whorton, Mark S.; Jackson, Mark

2000-01-01

Vibration isolation control system design for a microgravity experiment mount is considered. The controller design based on dynamic sliding manifold (DSM) technique is proposed to attenuate the accelerations transmitted to an isolated experiment mount either from a vibrating base or directly generated by the experiment, as well as to stabilize the internal dynamics of this nonminimum phase plant. An auxiliary DSM is employed to maintain the high-order sliding mode on the primary sliding manifold in the presence of uncertain actuator dynamics of second order. The primary DSM is designed for the closed-loop system in sliding mode to be a filter with given characteristics with respect to the input external disturbances.

HIV-1 sequence variation between isolates from mother-infant transmission pairs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wike, C.M.; Daniels, M.R.; Furtado, M.

1991-12-31

To examine the sequence diversity of human immunodeficiency virus type 1 (HIV-1) between known transmission sets, sequences from the V3 and V4-V5 region of the env gene from 4 mother-infant pairs were analyzed. The mean interpatient sequence variation between isolates from linked mother-infant pairs was comparable to the sequence diversity found between isolates from other close contacts. The mean intrapatient variation was significantly less in the infants` isolates then the isolates from both their mothers and other characterized intrapatient sequence sets. In addition, a distinct and characteristic difference in the glycosylation pattern preceding the V3 loop was found between eachmore » linked transmission pair. These findings indicate that selection of specific genotypic variants, which may play a role in some direct transmission sets, and the duration of infection are important factors in the degree of diversity seen between the sequence sets.« less

Enzymatic properties of a GH19 chitinase isolated from rice lacking a major loop structure involved in chitin binding.

PubMed

Tanaka, Jun; Fukamizo, Tamo; Ohnuma, Takayuki

2017-05-01

The catalytic domains of family GH19 chitinases have been found to consist of a conserved, α-helical core-region and different numbers (1-6) of loop structures, located at both ends of the substrate-binding groove and which extend over the glycon- and aglycon-binding sites. We expressed, purified and enzymatically characterized a GH19 chitinase from rice, Oryza sativa L. cv. Nipponbare (OsChia2a), lacking a major loop structure (loop III) connected to the functionally important β-stranded region. The new enzyme thus contained the five remaining loop structures (loops I, II, IV, V and C-term). The OsChia2a recombinant protein catalyzed hydrolysis of chitin oligosaccharides, (GlcNAc)n (n = 3-6), with inversion of anomeric configuration, indicating that OsChia2a correctly folded without loop III. From thermal unfolding experiments and calorimetric titrations using the inactive OsChia2a mutant (OsChia2a-E68Q), in which the catalytic residue Glu68 was mutated to glutamine, we found that the binding affinities towards (GlcNAc)n (n = 2-6) were almost proportional to the degree of polymerization of (GlcNAc)n, but were much lower than those obtained for a moss GH19 chitinase having only loop III [Ohnuma T, Sørlie M, Fukuda T, Kawamoto N, Taira T, Fukamizo T. 2011. Chitin oligosaccharide binding to a family GH19 chitinase from the moss, Bryum coronatum. FEBS J. 278:3991-4001]. Nevertheless, OsChia2a exhibited significant antifungal activity. It appears that loop III connected to the β-stranded region is important for (GlcNAc)n binding, but is not essential for antifungal activity. © The Author 2017. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Getting a New Liver: Facts about Liver Transplants

MedlinePlus

... a tube to the outside of your body. 6 o In some cases, a small piece of the intestine is connected to the new donor bile duct. This connection is called a Roux-en-Y. o It will take ... will take six to eight hours. After Your Operation You will ...

Effects of endocrine and inflammatory changes on markers of bone turnover following Roux-en-Y gastric bypass surgery

USDA-ARS?s Scientific Manuscript database

Bariatric surgery is associated with increased bone turnover. The mechanisms involved are unclear but may involve nutrition, mechanical unloading, altered secretion of gastrointestinal and adipose hormones and changes in inflammatory status leading to weight loss induced bone loss. We assessed marke...

Relevance of bovine tuberculosis research to the understanding of human disease: Historical perspectives, approaches, and immunologic mechanisms

USDA-ARS?s Scientific Manuscript database

Pioneer studies on infectious disease and immunology by Jenner, Pasteur, Koch, Von Behring, Nocard, Roux, and Ehrlich forged a path for the dual-purpose with dual benefit approach, demonstrating a profound relevance of veterinary studies for biomedical applications. Tuberculosis (TB), primarily due ...

An Integrated Programmable Wide-range PLL for Switching Synchronization in Isolated DC-DC Converters

NASA Astrophysics Data System (ADS)

Fard, Miad

In this thesis, two Phase-Locked-Loop (PLL) based synchronization schemes are introduced and applied to a bi-directional Dual-Active-Bridge (DAB) dc-dc converter with an input voltage up to 80 V switching in the range of 250 kHz to 1 MHz. The two schemes synchronize gating signals across an isolated boundary without the need for an isolator per transistor. The Power Transformer Sensing (PTS) method utilizes the DAB power transformer to indirectly sense switching on the secondary side of the boundary, while the Digital Isolator Sensing (DIS) method utilizes a miniature transformer for synchronization and communication at up to 100 MHz. The PLL is implemented on-chip, and is used to control an external DAB power-stage. This work will lead to lower cost, high-frequency isolated dc-dc converters needed for a wide variety of emerging low power applications where isolator cost is relatively high and there is a demand for the reduction of parts.

Effect of a Near Fault on the Seismic Response of a Base-Isolated Structure with a Soft Storey

NASA Astrophysics Data System (ADS)

Athamnia, B.; Ounis, A.; Abdeddaim, M.

2017-12-01

This study focuses on the soft-storey behavior of RC structures with lead core rubber bearing (LRB) isolation systems under near and far-fault motions. Under near-fault ground motions, seismic isolation devices might perform poorly because of large isolator displacements caused by large velocity and displacement pulses associated with such strong motions. In this study, four different structural models have been designed to study the effect of soft-storey behavior under near-fault and far-fault motions. The seismic analysis for isolated reinforced concrete buildings is carried out using a nonlinear time history analysis method. Inter-story drifts, absolute acceleration, displacement, base shear forces, hysteretic loops and the distribution of plastic hinges are examined as a result of the analysis. These results show that the performance of a base isolated RC structure is more affected by increasing the height of a story under nearfault motion than under far-fault motion.

Isolated Learners: Young Mature-Age Students, University Culture, and Desire for Academic Sociality

ERIC Educational Resources Information Center

Mallman, Mark; Lee, Helen

2017-01-01

The differentiated experiences of "young" mature-age students are under-researched and often unacknowledged in higher education literature and university policy. This article contends that, due to their age (early 20s to early 30s), many younger mature-age students feel "out of the loop" and "alienated" from…

Isolation, characterization, and expression analyses of plant elicitor peptides (pep) genes in maize

USDA-ARS?s Scientific Manuscript database

PROPEP1, PROPEP 2, and PROPEP3 genes appear to have roles in a feedback loop that amplifies defense signaling pathways initiated by pathogens. We present evidence to support the role of peptides derived from PROPEP genes as endogenous elicitors that are generated in response to pathogens. The preval...

ENVIRONMENTAL BENIGN MITIGATION OF MICROBIOLOGICALLY INFLUENCED CORROSION (MIC)

DOE Office of Scientific and Technical Information (OSTI.GOV)

J.R. Paterek; G. Husmillo; V. Trbovic

The overall program objective is to develop and evaluate environmental benign agents or products that are effective in the prevention, inhibition, and mitigation of microbially influenced corrosion (MIC) in the internal surfaces of metallic natural gas pipelines. The goal is one or more environmental benign, a.k.a. ''green'' products that can be applied to maintain the structure and dependability of the natural gas infrastructure. The technical approach for this quarter were isolation and cultivation of MIC-causing microorganisms from corroded pipeline samples, optimizing parameters in the laboratory-scale corrosion test loop system and testing the effective concentrations of Capsicum sp. extracts to verifymore » the extent of corrosion on metal coupons by batch culture method. A total of 22 strains from the group of heterotrophic, acid producing, denitrifying and sulfate reducing bacteria were isolated from the gas pipeline samples obtained from Northern Indiana Public Service Company in Trenton, Indiana. They were purified and will be sent out for identification. Bacterial strains of interest were used in antimicrobial screenings and test loop experiments. Parameters for the laboratory-scale test loop system such as gas and culture medium flow rate; temperature; inoculation period; and length of incubation were established. Batch culture corrosion study against Desulfovibrio vulgaris showed that one (S{sub 1}M) out of the four Capsicum sp. extracts tested was effective in controlling the corrosion rate in metal coupons by 33.33% when compared to the untreated group.« less

Explaining observed red and blue-shifts using multi-stranded coronal loops

NASA Astrophysics Data System (ADS)

Regnier, S.; Walsh, R. W.; Pearson, J.

2012-03-01

Magnetic plasma loops have been termed the building blocks of the solar atmosphere. However, it must be recognised that if the range of loop structures we can observe do consist of many ''sub-resolution'' elements, then current one-dimensional hydrodynamic models are really only applicable to an individual plasma element or strand. Thus a loop should be viewed is an amalgamation of these strands. They could operate in thermal isolation from one another with a wide range of temperatures occurring across the structural elements. This scenario could occur when the energy release mechanism consists of localised, discrete bursts of energy that are due to small scale reconnection sites within the coronal magnetic field- the nanoflare coronal heating mechanism. These energy bursts occur in a time-dependent manner, distributed along the loop/strand length, giving a heating function that depends on space and time. An important observational discovery with the Hinode/EIS spectrometer is the existence of red and blue-shifts in coronal loops depending on the location of the footpoints (inner or outer parts of the active region), and the temperature of the emission line in which the Doppler shifts are measured. Based on the multi-stranded model developed by Sarkar and Walsh (2008, ApJ, 683, 516), we show that red and blue-shifts exist in different simulated Hinode/EIS passbands: cooler lines (OV-SiVII) being dominated by red-shifts, whilst hotter lines (FeXV-CaXVII) are a combination of both. The distribution of blue-shifts depends on the energy input and not so much on the heating location. Characteristic Doppler shifts generated fit well with observed values. We also simulate the Hinode/EIS rasters to closely compare our simulation with the observations. Even if not statistically significant, loops can have footpoints with opposite Doppler shifts.

Understanding the molecular mechanism of the broad and potent neutralization of HIV-1 by antibody VRC01 from the perspective of molecular dynamics simulation and binding free energy calculations.

PubMed

Zhang, Yan; Pan, Dabo; Shen, Yulin; Jin, Nengzhi; Liu, Huanxiang; Yao, Xiaojun

2012-09-01

VRC01 is one of the most broadly and potently neutralizing HIV-1 antibodies known-it has been shown to neutralize 91 % of the tested primary isolate Env pseudoviruses by recognizing the viral envelope glycoprotein gp120. To explore the mechanism of HIV-1 neutralization by VRC01 and thus obtain valuable information for vaccine design, we performed molecular dynamics simulations and binding free energy calculations for apo-VRC01, apo-gp120, and the gp120-VRC01 complex. For gp120, residue energy decomposition analysis showed that the hotspot residues Asn280, Lys282, Asp368, Ile371, and Asp457 are located in three primary loops, including the CD4-binding loop, loop D, and loop V5. For VRC01, the hotspot residues Trp47, Trp50, Asn58, Arg61, Gln64, Trp100, and Tyr91 mainly come from CDR2 of the heavy chain. By decomposing the binding free energy into different components, intermolecular van der Waals interactions and nonpolar solvation were found to dominate the binding process. Principal component analysis of loops D and V5, which are related to neutralization resistance, indicated that these two areas have a larger conformational space in apo-gp120 compared to bound gp120. A comparison of three representative structures from the cluster analysis of loops D and V5 indicated that changes primarily occur at the tip of loop V5, and are caused by fluctuations in the terminal Glu1 residue of the antibody. This information can be used to guide the design of vaccines and small molecule inhibitors.

High-Throughput Microfluidic Labyrinth for the Label-free Isolation of Circulating Tumor Cells.

PubMed

Lin, Eric; Rivera-Báez, Lianette; Fouladdel, Shamileh; Yoon, Hyeun Joong; Guthrie, Stephanie; Wieger, Jacob; Deol, Yadwinder; Keller, Evan; Sahai, Vaibhav; Simeone, Diane M; Burness, Monika L; Azizi, Ebrahim; Wicha, Max S; Nagrath, Sunitha

2017-09-27

We present "Labyrinth," a label-free microfluidic device to isolate circulating tumor cells (CTCs) using the combination of long loops and sharp corners to focus both CTCs and white blood cells (WBCs) at a high throughput of 2.5 mL/min. The high yield (>90%) and purity (600 WBCs/mL) of Labyrinth enabled us to profile gene expression in CTCs. As proof of principle, we used previously established cancer stem cell gene signatures to profile single cells isolated from the blood of breast cancer patients. We observed heterogeneous subpopulations of CTCs expressing genes for stem cells, epithelial cells, mesenchymal cells, and cells transitioning between epithelial and mesenchymal. Labyrinth offers a cell-surface marker-independent single-cell isolation platform to study heterogeneous CTC subpopulations. Copyright © 2017 Elsevier Inc. All rights reserved.

K99 antigen-positive enterotoxigenic Escherichia coli from piglets with diarrhea in Sweden.

PubMed Central

Smyth, C J; Olsson, E; Moncalvo, C; Söderlind, O; Orskov, F; Orskov, I

1981-01-01

K88 antigen-negative enterotoxigenic Escherichia coli and non-enterotoxigenic strains isolated from piglets with diarrhea were examined for K99 antigen by agglutination tests after growth on Minca-IsoVitaleX (BBL Microbiology Systems, Cockeysville, Md.) agar medium. Of 64 K88-negative enterotoxigenic strains from as many piglets, 17 were found to be K99 positive. Of these, 10 were Swedish and 7 were of Norwegian origin. All 17 produced heat-stable enterotoxin detectable in the infant mouse assay, but only 2 gave positive ligated loop tests in 3- to 7-week-old piglets. Ligated loop tests in 5- to 12-day-old piglets were positive for each of the 15 K99-positive strains tested. Each of the Swedish K99-positive isolates was from a piglet of lesser than or equal to 7 days of age. One piglet harboring a K99-positive strain also harbored an O141:K88 enterotoxigenic strain producing only heat-stable enterotoxin. Five of the Swedish piglets yielding K99-positive isolates were from dams vaccinated wih a multicomponent bacterial vaccine containing K88 antigen. The K99 strains were O:K:H serotyped. The O serogroups represented were O8, O9, O64, O101, and O140. None of the 101 non-enterotoxigenic porcine isolates, representing 42 serogroups and non-O-groupable and rough strains, was found to be K99 positive. The findings indicate that so-called class 2 or atypical porcine enterotoxigenic E. coli should be routinely examined for the presence of K99 antigen. PMID:7009634

Mumps virus reinfection is not a rare event confirmed by reverse transcription loop-mediated isothermal amplification.

PubMed

Yoshida, Naoko; Fujino, Motoko; Miyata, Akiko; Nagai, Takao; Kamada, Makoto; Sakiyama, Hiroshi; Ihara, Toshiaki; Kumagai, Takuji; Okafuji, Teruo; Okafuji, Takao; Nakayama, Tetsuo

2008-03-01

Clinically apparent mumps reinfection is considered extremely rare, but several cases have been suspected of reinfection in an out-patient clinic. In this study, virological examination, virus isolation, the reverse transcription loop-mediated isothermal amplification (RT-LAMP), and IgG and IgM EIA antibodies, were examined in order to identify mumps reinfection. Patients were divided into three categories; the reinfection group comprised 29 patients with a history of natural infection, the vaccine-failure group consisted of 37 patients with an immunization history, and two patients had histories of both immunization and mumps infection. Another 25 patients were enrolled as a primary infection group. Mumps virus was isolated in 5 (17%) and the genome was detected in 12 (41%) of 29 in the reinfection group. Reinfection was confirmed in 21/28, demonstrating high avidity of IgG EIA. Mumps virus was isolated in 15 (41%) and there was a higher positivity of genome amplification in 25 (68%) of 37 patients in the vaccine-failure group. Among these, 23 were confirmed as secondary vaccine failure by high avidity IgG EIA serology. In the primary infection group, the isolation rate and genome detection rate was higher in 16 (64%) and in 18 (72%) of 25 patients, respectively. There was no significant difference in virus load among the three groups but high mumps virus load was suspected in the IgM EIA-positive group based on the shorter amplification time on RT-LAMP. Mumps virus reinfection was confirmed by RT-LAMP and an IgG avidity test and was not a rare event.

Spermine stimulation of a nuclear NII kinase from pea plumules and its role in the phosphorylation of a nuclear polypeptide

NASA Technical Reports Server (NTRS)

Datta, N.; Schell, M. B.; Roux, S. J.

1987-01-01

We have previously demonstrated that spermine stimulates the phosphorylation of a 47 kilodalton nuclear polypeptide from pea plumules (N Datta, LK Hardison, SJ Roux 1986 Plant Physiol 82: 681-684). In this paper we report that spermine stimulates the activity of a cyclic AMP independent casein kinase, partially purified from a chromatin fraction of pea plumule nuclei. This effect of spermine was substrate specific; i.e. with casein as substrate, spermine stimulated the kinase activity, and with phosvitin as substrate, spermine completely inhibited the activity. The stimulation by spermine of the casein kinase was, in part, due to the lowering of the Mg2+ requirement of the kinase. Heparin could partially inhibit this casein kinase activity and spermine completely overcame this inhibition. By further purification of the casein kinase extract on high performance liquid chromatography, we fractionated it into an NI and an NII kinase. Spermine stimulated the NII kinase by 5- to 6-fold but had no effect on the NI kinase. Using [gamma-32P]GTP, we have shown that spermine promotes the phosphorylation of the 47 kilodalton polypeptide(s) in isolated nuclei, at least in part by stimulating an NII kinase.

High Power Q-Switched Thulium Doped Fibre Laser using Carbon Nanotube Polymer Composite Saturable Absorber

PubMed Central

Chernysheva, Maria; Mou, Chengbo; Arif, Raz; AlAraimi, Mohammed; Rümmeli, Mark; Turitsyn, Sergei; Rozhin, Aleksey

2016-01-01

We have proposed and demonstrated a Q-switched Thulium doped fibre laser (TDFL) with a ‘Yin-Yang’ all-fibre cavity scheme based on a combination of nonlinear optical loop mirror (NOLM) and nonlinear amplified loop mirror (NALM). Unidirectional lasing operation has been achieved without any intracavity isolator. By using a carbon nanotube polymer composite based saturable absorber (SA), we demonstrated the laser output power of ~197 mW and pulse energy of 1.7 μJ. To the best of our knowledge, this is the highest output power from a nanotube polymer composite SA based Q-switched Thulium doped fibre laser. PMID:27063511

A girl with spina bifida, an extra leg, and ectopic intestinal loops--a "foetus in foetu" or a whim of the neural crest?

PubMed

Lende, G; Wendemu, W; Mørk, S; Wester, K

2007-10-01

This article describes a girl with an extra leg attached to her lower back, combined with a spina bifida and a myelomeningocele. Despite lacking sensory or motor functions, the leg grew proportionately with the rest of the body. The bony structures were almost normal. A cross section showed fat tissue with some centrally situated blood vessels, nerve bundles, and muscular fragments. Proximally, an isolated colon loop was found. The extra leg and intestine respected the dorsal fascia, without connection with the peritoneal or retroperitoneal compartments. The finding is discussed with reference to existing hypotheses for limb formation.

A Closed-tube Loop-Mediated Isothermal Amplification Assay for the Visual Endpoint Detection of Brucella spp. and Mycobacterium avium subsp. paratuberculosis.

PubMed

Trangoni, Marcos D; Gioffré, Andrea K; Cravero, Silvio L

2017-01-01

LAMP (loop-mediated isothermal amplification) is an isothermal nucleic acid amplification technique that is characterized by its efficiency, rapidity, high yield of final product, robustness, sensitivity, and specificity, with the blueprint that it can be implemented in laboratories of low technological complexity. Despite the conceptual complexity underlying the mechanistic basis for the nucleic acid amplification, the technique is simple to use and the amplification and detection can be carried out in just one step. In this chapter, we present a protocol based on LAMP for the rapid identification of isolates of Brucella spp. and Mycobacterium avium subsp. paratuberculosis, two major bacterial pathogens in veterinary medicine.

A Multiwavelength Study of Coronal Structure: A Simultaneous Observation from NIXT and YOHKOH

NASA Technical Reports Server (NTRS)

Golub, Leon

1998-01-01

Solar soft X-ray images taken simultaneously by the Yohkoh and the Normal Incidence X-ray Telescope (NIXT) reveal significantly different coronal structures. Coronal loops are more clearly seen in the Yohkoh images, and the isolated island-like structures seen in the NIXT image have been found to correspond to the footpoints of the Yohkoh loops. The difference is due to the difference in the temperature response of the telescopes: NIXT is sensitive to temperatures ranging from 0.9 to 3 MK, while Yohkoh is more sensitive to temperatures above 2.5 MK. The morphological differences reflect the multi-temperature (1-5 MK) nature of the solar coronal plasmas.

Transepithelial water and urea permeabilities of isolated perfused Munich-Wistar rat inner medullary thin limbs of Henle's loop.

PubMed

Nawata, C Michele; Evans, Kristen K; Dantzler, William H; Pannabecker, Thomas L

2014-01-01

To better understand the role that water and urea fluxes play in the urine concentrating mechanism, we determined transepithelial osmotic water permeability (Pf) and urea permeability (Purea) in isolated perfused Munich-Wistar rat long-loop descending thin limbs (DTLs) and ascending thin limbs (ATLs). Thin limbs were isolated either from 0.5 to 2.5 mm below the outer medulla (upper inner medulla) or from the terminal 2.5 mm of the inner medulla. Segment types were characterized on the basis of structural features and gene expression levels of the water channel aquaporin 1, which was high in the upper DTL (DTLupper), absent in the lower DTL (DTLlower), and absent in ATLs, and the Cl-(1) channel ClCK1, which was absent in DTLs and high in ATLs. DTLupper Pf was high (3,204.5 ± 450.3 μm/s), whereas DTLlower showed very little or no osmotic Pf (207.8 ± 241.3 μm/s). Munich-Wistar rat ATLs have previously been shown to exhibit no Pf. DTLupper Purea was 40.0 ± 7.3 × 10(-5) cm/s and much higher in DTLlower (203.8 ± 30.3 × 10(-5) cm/s), upper ATL (203.8 ± 35.7 × 10(-5) cm/s), and lower ATL (265.1 ± 49.8 × 10(-5) cm/s). Phloretin (0.25 mM) did not reduce DTLupper Purea, suggesting that Purea is not due to urea transporter UT-A2, which is expressed in short-loop DTLs and short portions of some inner medullary DTLs close to the outer medulla. In summary, Purea is similar in all segments having no osmotic Pf but is significantly lower in DTLupper, a segment having high osmotic Pf. These data are inconsistent with the passive mechanism as originally proposed.

CdiA Effectors from Uropathogenic Escherichia coli Use Heterotrimeric Osmoporins as Receptors to Recognize Target Bacteria

PubMed Central

Beck, Christina M.; Willett, Julia L. E.; Kim, Jeff J.; Low, David A.; Hayes, Christopher S.

2016-01-01

Many Gram-negative bacterial pathogens express contact-dependent growth inhibition (CDI) systems that promote cell-cell interaction. CDI+ bacteria express surface CdiA effector proteins, which transfer their C-terminal toxin domains into susceptible target cells upon binding to specific receptors. CDI+ cells also produce immunity proteins that neutralize the toxin domains delivered from neighboring siblings. Here, we show that CdiAEC536 from uropathogenic Escherichia coli 536 (EC536) uses OmpC and OmpF as receptors to recognize target bacteria. E. coli mutants lacking either ompF or ompC are resistant to CDIEC536-mediated growth inhibition, and both porins are required for target-cell adhesion to inhibitors that express CdiAEC536. Experiments with single-chain OmpF fusions indicate that the CdiAEC536 receptor is heterotrimeric OmpC-OmpF. Because the OmpC and OmpF porins are under selective pressure from bacteriophages and host immune systems, their surface-exposed loops vary between E. coli isolates. OmpC polymorphism has a significant impact on CDIEC536 mediated competition, with many E. coli isolates expressing alleles that are not recognized by CdiAEC536. Analyses of recombinant OmpC chimeras suggest that extracellular loops L4 and L5 are important recognition epitopes for CdiAEC536. Loops L4 and L5 also account for much of the sequence variability between E. coli OmpC proteins, raising the possibility that CDI contributes to the selective pressure driving OmpC diversification. We find that the most efficient CdiAEC536 receptors are encoded by isolates that carry the same cdi gene cluster as E. coli 536. Thus, it appears that CdiA effectors often bind preferentially to "self" receptors, thereby promoting interactions between sibling cells. As a consequence, these effector proteins cannot recognize nor suppress the growth of many potential competitors. These findings suggest that self-recognition and kin selection are important functions of CDI. PMID:27723824

Magnetic field homogeneity of a conical coaxial coil pair.

PubMed

Salazar, F J; Nieves, F J; Bayón, A; Gascón, F

2017-09-01

An analytical study of the magnetic field created by a double-conical conducting sheet is presented. The analysis is based on the expansion of the magnetic field in terms of Legendre polynomials. It is demonstrated analytically that the angle of the conical surface that produces a nearly homogeneous magnetic field coincides with that of a pair of loops that fulfills the Helmholtz condition. From the results obtained, we propose an electric circuit formed by pairs of isolated conducting loops tightly wound around a pair of conical surfaces, calculating numerically the magnetic field produced by this system and its heterogeneity. An experimental setup of the proposed circuit was constructed and its magnetic field was measured. The results were compared with those obtained by numerical calculation, finding a good agreement. The numerical results demonstrate a significant improvement in homogeneity in the field of the proposed pair of conical coils compared with that achieved with a simple pair of Helmholtz loops or with a double solenoid. Moreover, a new design of a double pair of conical coils based on Braunbek's four loops is also proposed to achieve greater homogeneity. Regarding homogeneity, the rating of the analyzed configurations from best to worst is as follows: (1) double pair of conical coils, (2) pair of conical coils, (3) Braunbek's four loops, (4) Helmholtz pair, and (5) solenoid pair.

Magnetic field homogeneity of a conical coaxial coil pair

NASA Astrophysics Data System (ADS)

Salazar, F. J.; Nieves, F. J.; Bayón, A.; Gascón, F.

2017-09-01

An analytical study of the magnetic field created by a double-conical conducting sheet is presented. The analysis is based on the expansion of the magnetic field in terms of Legendre polynomials. It is demonstrated analytically that the angle of the conical surface that produces a nearly homogeneous magnetic field coincides with that of a pair of loops that fulfills the Helmholtz condition. From the results obtained, we propose an electric circuit formed by pairs of isolated conducting loops tightly wound around a pair of conical surfaces, calculating numerically the magnetic field produced by this system and its heterogeneity. An experimental setup of the proposed circuit was constructed and its magnetic field was measured. The results were compared with those obtained by numerical calculation, finding a good agreement. The numerical results demonstrate a significant improvement in homogeneity in the field of the proposed pair of conical coils compared with that achieved with a simple pair of Helmholtz loops or with a double solenoid. Moreover, a new design of a double pair of conical coils based on Braunbek's four loops is also proposed to achieve greater homogeneity. Regarding homogeneity, the rating of the analyzed configurations from best to worst is as follows: (1) double pair of conical coils, (2) pair of conical coils, (3) Braunbek's four loops, (4) Helmholtz pair, and (5) solenoid pair.

Evaluation of in vivo and in vitro biological activity of a Vibrio cholerae 01 hemolysin.

PubMed

Arellano Galindo, José; Rodriquez Angeles, María Guadalupe; Guadarrama, Norma Valázquez; Esteban, Enrique Santos; Cerezo, Silvia Giono

2007-01-01

To evaluate the hemolysin effect by ileal loop model produced by Vibrio cholerae O1 strains, compared with the cellular lysis or cytotoxic activity (CA) observed in cell culture. We studied nine V. cholerae O1 strains, obtained during the Mexican outbreak of cholera (1990-1993), which had CA in Vero and CHO cells. Hemolysin was monitored with the hemolysis test. Titers of CA were calculated by CD50, and the association between CA and cholera toxin (CT) production was discarded by means of neutralization tests using an anti-CT polyclonal antibody. The CT production was measured with ELISA test. The LAL assay was performed in order to study relationships between the CA and bacterial lipopolysaccharide. Strains with CA were evaluated in rabbit and rat ileal loop models; hemorrhagic fluid was also measured. Tissues from ileal loop were included in paraffin to detect intestinal epithelial damage. The hemolysin CA was not neutralized with the anti-CT polyclonal antibody. However, the associated factor of CA was heat labile. CA in cell cultures was not related to the bacterial lipopolysaccharide. The ileal loop test exhibited the presence of hemorrhagic tissue with inflammation. The V. cholerae O1 strains isolated were able to secrete hemolysin which, in turn, caused CA in cell cultures and produced the hemorrhagic and inflammatory effects observed in the ileal loop of rabbit and rat models.

Condensed tannins: A proposed route to 2R,3R-(2,3-cis)-proanthocyanidins

Treesearch

Richard W. Hemingway; Peter E. Laks

1985-01-01

Roux,1 Haslam,2-4 and Stafford5-8 have proposed differing biogenetic schemes for the formation of proanthocyanidins (condensed tannins) in plants. All three schemes suffer from difficulties in explaining the formation of the 2R,3R-(2,3-cis)-proanthocyanidins that predominate in...

EARLY POSTOPERATIVE COMPLICATIONS IN ROUX-EN-Y GASTRIC BYPASS

PubMed Central

STOLL, Aluisio; ROSIN, Leandro; DIAS, Mariana Fernandes; MARQUIOTTI, Bruna; GUGELMIN, Giovana; STOLL, Gabriela Fanezzi

2016-01-01

ABSTRACT Background: Roux-en-Y gastric bypass is one of the most common bariatric surgery and leads to considerable weight loss in the first months. Aim: To quantify the main early postoperative complications in patients submitted to the gastric bypass. Method: Observational retrospective cohort. Data of 1051 patients with class II obesity associated with comorbidities or class III obesity submitted to the gastric bypass with 30 days of follow-up starting from the date of the surgery. Results: The age average was 36 years with a predominance of females (81.1%). The mean preoperative body mass index was 43 kg/m². The major complication was fistula (2.3%), followed by intestinal obstruction (0.5%) and pulmonary embolism (0.5%). Death occurred in 0.6% of the cases. Conclusion: In the period of 30 days after surgery the overall complication rate was 3.8%; reoperation was necessary in 2.6% and death occurred in 0.6%. Fistula was the main complication and the leading cause of hospitalization in intensive care unit, reoperation and death. PMID:27683781

Pancreatogenic choledocholithiasis in common bile duct stump after Roux-en-Y hepaticojejunostomy

PubMed Central

Jiang, Yuan-Hui; Zhang, An-Hong; Zhou, Shao-Jun

2017-01-01

Abstract Rationale: Choledocholithiasis in common bile duct (CBD) stump after Roux-en-Y hepaticojejunostomy (RYHJ) is incredibly rare and its pathophysiology is poorly understood. Patient concerns: A 79-year-old woman was admitted to our hospital with upper abdominal pain radiating through to the back in November 2016. Diagnoses: Abdominal computed tomography (CT) scan and magnetic resonance cholangiopancreatography (MRCP) revealed filling defects in CBD stump, chronic pancreatitis, and dilatation of CBD stump and main pancreatic duct (MPD). Interventions: During the endoscopic retrograde cholangiopancreatography (ERCP), cannulation proceeded easily from MPD to CBD through a variant pancreatic duct, and then white crushed stones extracted from the CBD stump. Elemental analysis and infrared spectrophotometry demonstrated that the main constituent of the calculi was calcium carbonate. Outcomes: After a therapeutic ERCP, the patient's symptoms disappeared, and a 9-month follow-up indicated no remaining stones or lithiasis relapse. Lessons: This type of choledocholithiasis in CBD stump after RYHJ has never been reported before. We nominated it as “pancreatogenic choledocholithiasis,” and pancreatobiliary reflux caused by a variant pancreatic duct may be the main cause. PMID:29145338

Enacting cultural boundaries in French and German diphtheria serum research.

PubMed

Klöppel, Ulrike

2008-06-01

The experimental development of a therapeutic serum against diphtheria between 1891 and 1894 was characterized by a scientific competition that pitted Emil Behring from the Institute for Infectious Diseases in Berlin against Emile Roux and Elie Metschnikoff from the Pasteur Institute in Paris. In general, their competition can be regarded as an extension of the fundamental differences that separated the research schools of Robert Koch and Louis Pasteur. However, to characterize the competition for a diphtheria-serum as "national rivalry" fails to account adequately for the mutual adoption of experimental practices by the Berlin and Parisian protagonists, whose contributions to the development of a therapeutic serum were intertwined in complex ways. Nor can it be characterized as "cooperation," given their fierce public disputes over scientific concepts and the fact that these disputes also shaped the peculiarities of the experimental procedures in Berlin and Paris. A close analysis reveals a complex picture of the dynamic interaction between the conceptual and experimental activities of Behring, Roux, and Metschnikoff- interaction that defined as well as bridged the "French" and "Prussian" experimental systems of diphtheria-serum research.

Stricture Rate after Laparoscopic Roux-en-Y Gastric Bypass with a 21-mm Circular Stapler versus a 25-mm Linear Stapler

PubMed Central

Vunnamadala, Kalyan; Sakharpe, Aniket; Wilhelm, B. Jakub; Aksade, Artun

2015-01-01

Background: Obesity is estimated to affect more than one and a half billion adults. Laparoscopic Roux-en-Y gastric bypass (LRYGB) has become one of the preferred weight loss procedures. However, complications can occur. Strictures at the gastrojejunal anastomosis lead to clinical symptoms such as vomiting, dysphagia, and patient discomfort. The stricture rate has been correlated with the size and type of stapler used. Methods: A retrospective review of the clinical records of patients who underwent LRYGB was performed between 2003 and 2010. A comparison was made between a 21-mm circular stapler technique and a 25-mm linear stapler technique. Results: The stricture rate for the 21-mm circular stapler group was 7.12% and comparable to the national average. Using the 25-mm linear stapler, this complication rate significantly decreased to 1.09% (p<0.0004; odds ratio 6.5; [95% confidence interval 1.96–33.83]). Conclusions: Stricture after LRYGB is a serious complication. This study found that with a change in technique, this complication can be decreased considerably. PMID:25830078

Excluded segmental duct bile leakage: the case for bilio-enteric anastomosis.

PubMed

Patrono, Damiano; Tandoi, Francesco; Romagnoli, Renato; Salizzoni, Mauro

2014-06-01

Excluded segmental duct bile leak is the rarest type of post-hepatectomy bile leak and presents unique diagnostic and management features. Classical management strategies invariably entail a significant loss of functioning hepatic parenchyma. The aim of this study is to report a new liver-sparing technique to handle excluded segmental duct bile leakage. Two cases of excluded segmental duct bile leak occurring after major hepatic resection were managed by a Roux-en-Y hepatico-jejunostomy on the excluded segmental duct, avoiding the sacrifice of the liver parenchyma origin of the fistula. In both cases, classical management strategies would have led to the functional loss of roughly 50 % of the liver remnant. Diagnostic and management implications are thoroughly discussed. Both cases had an uneventful postoperative course. The timing of repair was associated with a different outcome: the patient who underwent surgical repair in the acute phase developed no long-term complications, whereas the patient who underwent delayed repair developed a late stenosis requiring percutaneous dilatation. Roux-en-Y hepatico-jejunostomy on the excluded bile duct is a valuable technique in selected cases of excluded segmental duct bile leakage.

Stricture Rate after Laparoscopic Roux-en-Y Gastric Bypass with a 21-mm Circular Stapler versus a 25-mm Linear Stapler.

PubMed

Baccaro, Leopoldo M; Vunnamadala, Kalyan; Sakharpe, Aniket; Wilhelm, B Jakub; Aksade, Artun

2015-03-01

Background: Obesity is estimated to affect more than one and a half billion adults. Laparoscopic Roux-en-Y gastric bypass (LRYGB) has become one of the preferred weight loss procedures. However, complications can occur. Strictures at the gastrojejunal anastomosis lead to clinical symptoms such as vomiting, dysphagia, and patient discomfort. The stricture rate has been correlated with the size and type of stapler used. Methods: A retrospective review of the clinical records of patients who underwent LRYGB was performed between 2003 and 2010. A comparison was made between a 21-mm circular stapler technique and a 25-mm linear stapler technique. Results: The stricture rate for the 21-mm circular stapler group was 7.12% and comparable to the national average. Using the 25-mm linear stapler, this complication rate significantly decreased to 1.09% ( p <0.0004; odds ratio 6.5; [95% confidence interval 1.96-33.83]). Conclusions: Stricture after LRYGB is a serious complication. This study found that with a change in technique, this complication can be decreased considerably.

Gastrojejunal Anastomosis Complications and Their Management after Laparoscopic Roux-en-Y Gastric Bypass.

PubMed

Fringeli, Yannick; Worreth, Marc; Langer, Igor

2015-01-01

Complications at the gastrojejunal anastomosis after laparoscopic Roux-en-Y gastric bypass (LRYGB) are challenging in terms of diagnosis, therapy, and prevention. This study aims at identifying these complications and discussing their management. Data of 228 patients who underwent a LRYGB between October 2008 and December 2011 were reviewed retrospectively to evaluate the frequency and treatment of complications such as stenoses, marginal ulcers, perforated marginal ulcers, or anastomotic leaks related to the operation. Follow-up information was available for 209 patients (91.7%) with a median follow-up of 38 months (range 24-62 months). Of these patients 16 patients (7.7%) experienced complications at the gastrojejunostomy. Four patients (1.9%) had stenoses and 12 patients (5.7%) marginal ulcers, one of them with perforation (0.5%). No anastomotic leaks were reported. One case with perforated ulcer and one with recurrent ulcers required surgical revision. Gastrojejunal anastomotic complications are frequent and occur within the first few days or up to several years after surgery. Stenoses or marginal ulcers are usually successfully treated nonoperatively. Laparoscopic repair, meanwhile, is an appropriate therapeutic option for perforated ulcers.

Appetite, Glycemia, and Entero-Insular Hormone Responses Differ Between Oral, Gastric-Remnant, and Duodenal Administration of a Mixed-Meal Test After Roux-en-Y Gastric Bypass.

PubMed

Gero, Daniel; Steinert, Robert E; Hosa, Hanna; Cummings, David E; Bueter, Marco

2018-06-01

To examine the effect of different feeding routes on appetite and metabolic responses after Roux-en-Y gastric bypass (RYGB). A standard liquid meal was administered either orally, into the gastric remnant, or intraduodenally 6 months after RYGB. Changes in plasma glucose, insulin, glucagon-like peptide 1 (GLP-1), glucose-dependent insulinotropic peptide (GIP), peptide YY (PYY), and appetite were measured pre- and postprandially. Postprandial GLP-1 and PYY responses were similar, whereas glucose, insulin, and GIP levels differed markedly after oral versus intraduodenal feeding. Intraduodenal feeding prompted an intermediate appetite response (i.e., between oral and intragastric). For postprandial glucose, insulin, and GIP levels, the intraduodenal route was more similar to the intragastric than the oral route. Intragastric administration did not evoke changes in appetite, glucose, or insulin; however, it slightly increased GLP-1 and PYY and moderately increased GIP. Appetite and metabolic responses after RYGB depend on the route by which nutrients enter the gastrointestinal tract. © 2018 by the American Diabetes Association.

Reconfiguration of the small intestine and diabetes remitting effects of Roux-en-Y gastric bypass surgery.

PubMed

Docherty, Neil G; le Roux, Carel W

2016-03-01

Alterations in small intestinal physiology are proposed to play a causative role in the beneficial impact of Roux-en-Y gastric bypass on type 2 diabetes mellitus. The present article describes the key proposed mechanisms implicated with an emphasis on some of the newer findings in the field. Augmented incretin and diminished anti-incretin effects postsurgery are explored and a model proposed that reconciles the hindgut and foregut hypotheses of improved glycaemic control as being complementary rather than mutually exclusive. Synthesis of recent findings on postbypass changes in intestinal glucose handling then follows. Finally an updated view of the role of distal bile diversion and changes in the microbiota on enteroendocrine signalling is presented. A series of nonmutually exclusive changes in small intestinal physiology likely make a significant contribution to improved glycaemic control postgastric bypass. Longitudinal data indicate that these effects do not translate into a long-term cure. A number of surgery-induced changes, however, are amenable to device-based and pharmacology-based mimicry, and this is an area for prioritization of future research focus.

Roux-en-Y Gastric Bypass and Vertical Banded Gastroplasty Induce Long-Term Changes on the Human Gut Microbiome Contributing to Fat Mass Regulation.

PubMed

Tremaroli, Valentina; Karlsson, Fredrik; Werling, Malin; Ståhlman, Marcus; Kovatcheva-Datchary, Petia; Olbers, Torsten; Fändriks, Lars; le Roux, Carel W; Nielsen, Jens; Bäckhed, Fredrik

2015-08-04

Bariatric surgery is currently the most effective procedure for the treatment of obesity. Given the role of the gut microbiota in regulating host metabolism and adiposity, we investigated the long-term effects of bariatric surgery on the microbiome of patients randomized to Roux-en-Y gastric bypass or vertical banded gastroplasty and matched for weight and fat mass loss. The two surgical procedures induced similar and durable changes on the gut microbiome that were not dependent on body mass index and resulted in altered levels of fecal and circulating metabolites compared with obese controls. By colonizing germ-free mice with stools from the patients, we demonstrated that the surgically altered microbiota promoted reduced fat deposition in recipient mice. These mice also had a lower respiratory quotient, indicating decreased utilization of carbohydrates as fuel. Our results suggest that the gut microbiota may play a direct role in the reduction of adiposity observed after bariatric surgery. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

Fission Surface Power Technology Demonstration Unit Test Results

NASA Technical Reports Server (NTRS)

Briggs, Maxwell H.; Gibson, Marc A.; Geng, Steven M.; Sanzi, James L.

2016-01-01

The Fission Surface Power (FSP) Technology Demonstration Unit (TDU) is a system-level demonstration of fission power technology intended for use on manned missions to Mars. The Baseline FSP systems consists of a 190 kWt UO2 fast-spectrum reactor cooled by a primary pumped liquid metal loop. This liquid metal loop transfers heat to two intermediate liquid metal loops designed to isolate fission products in the primary loop from the balance of plant. The intermediate liquid metal loops transfer heat to four Stirling Power Conversion Units (PCU), each of which produce 12 kWe (48 kW total) and reject waste heat to two pumped water loops, which transfer the waste heat to titanium-water heat pipe radiators. The FSP TDU simulates a single leg of the baseline FSP system using an electrically heater core simulator, a single liquid metal loop, a single PCU, and a pumped water loop which rejects the waste heat to a Facility Cooling System (FCS). When operated at the nominal operating conditions (modified for low liquid metal flow) during TDU testing the PCU produced 8.9 kW of power at an efficiency of 21.7 percent resulting in a net system power of 8.1 kW and a system level efficiency of 17.2 percent. The reduction in PCU power from levels seen during electrically heated testing is the result of insufficient heat transfer from the NaK heater head to the Stirling acceptor, which could not be tested at Sunpower prior to delivery to the NASA Glenn Research Center (GRC). The maximum PCU power of 10.4 kW was achieved at the maximum liquid metal temperature of 875 K, minimum water temperature of 350 K, 1.1 kg/s liquid metal flow, 0.39 kg/s water flow, and 15.0 mm amplitude at an efficiency of 23.3 percent. This resulted in a system net power of 9.7 kW and a system efficiency of 18.7 percent.

Fission Surface Power Technology Demonstration Unit Test Results

NASA Technical Reports Server (NTRS)

Briggs, Maxwell H.; Gibson, Marc A.; Geng, Steven; Sanzi, James

2016-01-01

The Fission Surface Power (FSP) Technology Demonstration Unit (TDU) is a system-level demonstration of fission power technology intended for use on manned missions to Mars. The Baseline FSP systems consists of a 190 kWt UO2 fast-spectrum reactor cooled by a primary pumped liquid metal loop. This liquid metal loop transfers heat to two intermediate liquid metal loops designed to isolate fission products in the primary loop from the balance of plant. The intermediate liquid metal loops transfer heat to four Stirling Power Conversion Units (PCU), each of which produce 12 kWe (48 kW total) and reject waste heat to two pumped water loops, which transfer the waste heat to titanium-water heat pipe radiators. The FSP TDU simulates a single leg of the baseline FSP system using an electrically heater core simulator, a single liquid metal loop, a single PCU, and a pumped water loop which rejects the waste heat to a Facility Cooling System (FCS). When operated at the nominal operating conditions (modified for low liquid metal flow) during TDU testing the PCU produced 8.9 kW of power at an efficiency of 21.7% resulting in a net system power of 8.1 kW and a system level efficiency of 17.2%. The reduction in PCU power from levels seen during electrically heated testing is the result of insufficient heat transfer from the NaK heater head to the Stirling acceptor, which could not be tested at Sunpower prior to delivery to GRC. The maximum PCU power of 10.4 kW was achieved at the maximum liquid metal temperature of 875 K, minimum water temperature of 350 K, 1.1 kg/s liquid metal flow, 0.39 kg/s water flow, and 15.0 mm amplitude at an efficiency of 23.3%. This resulted in a system net power of 9.7 kW and a system efficiency of 18.7 %.

Biomolecular and structural analyses of cauliflower-like DNAs by ultraviolet, circular dichroism, and fluorescence spectroscopies in comparison with natural DNA.

PubMed

Gill, Pooria; Ranjbar, Bijan; Saber, Reza; Khajeh, Khosro; Mohammadian, Mehdi

2011-07-01

Cauliflower-like DNAs are stem-loop DNAs that are fabricated periodically in inverted repetitions from deoxyribonucleic acid phosphates (dNTPs) by loop-mediated isothermal amplification (LAMP). Cauliflower-like DNAs have ladder-shape behaviors on gel electrophoresis, and increasing the time of LAMP leads to multiplying the repetitions, stem-loops, and electrophoretic bands. Cauliflower-like DNAs were fabricated via LAMP using two loop primers, two bumper primers, dNTPs, a λ-phage DNA template, and a Bst DNA polymerase in 75- and 90-min periods. These times led to manufacturing two types of cauliflower-like DNAs with different contents of inverted repetitions and stem-loops, which were clearly indicated by two comparable electrophoresis patterns in agarose gel. LAMP-fabricated DNAs and natural dsB-DNA (salmon genomic DNA) were dialyzed in Gomori phosphate buffer (10 mM, pH 7.4) to be isolated from salts, nucleotides, and primers. Dialyzed DNAs were studied using UV spectroscopy, circular dichroism spectropolarimetry, and fluorescence spectrophotometry. Structural analyses indicated reduction of the molecular ellipticity and extinction coefficients in comparison with B-DNA. Also, cauliflower-like DNAs demonstrated less intrinsic and more extrinsic fluorescence in comparison with natural DNA. The overwinding and lengthening of the cauliflower-like configurations of LAMP DNAs led to changes in physical parameters of this type of DNA in comparison with natural DNA. The results obtained introduced new biomolecular characteristics of DNA macromolecules fabricated within a LAMP process and show the effects of more inverted repeats and stem-loops, which are manufactured by lengthening the process.

Input filter compensation for switching regulators

NASA Technical Reports Server (NTRS)

Kelkar, S. S.; Lee, F. C.

1983-01-01

A novel input filter compensation scheme for a buck regulator that eliminates the interaction between the input filter output impedance and the regulator control loop is presented. The scheme is implemented using a feedforward loop that senses the input filter state variables and uses this information to modulate the duty cycle signal. The feedforward design process presented is seen to be straightforward and the feedforward easy to implement. Extensive experimental data supported by analytical results show that significant performance improvement is achieved with the use of feedforward in the following performance categories: loop stability, audiosusceptibility, output impedance and transient response. The use of feedforward results in isolating the switching regulator from its power source thus eliminating all interaction between the regulator and equipment upstream. In addition the use of feedforward removes some of the input filter design constraints and makes the input filter design process simpler thus making it possible to optimize the input filter. The concept of feedforward compensation can also be extended to other types of switching regulators.

Solution structure of a GAAA tetraloop receptor RNA.

PubMed Central

Butcher, S E; Dieckmann, T; Feigon, J

1997-01-01

The GAAA tetraloop receptor is an 11-nucleotide RNA sequence that participates in the tertiary folding of a variety of large catalytic RNAs by providing a specific binding site for GAAA tetraloops. Here we report the solution structure of the isolated tetraloop receptor as solved by multidimensional, heteronuclear magnetic resonance spectroscopy. The internal loop of the tetraloop receptor has three adenosines stacked in a cross-strand or zipper-like fashion. This arrangement produces a high degree of base stacking within the asymmetric internal loop without extrahelical bases or kinking the helix. Additional interactions within the internal loop include a U. U mismatch pair and a G.U wobble pair. A comparison with the crystal structure of the receptor RNA bound to its tetraloop shows that a conformational change has to occur upon tetraloop binding, which is in good agreement with previous biochemical data. A model for an alternative binding site within the receptor is proposed based on the NMR structure, phylogenetic data and previous crystallographic structures of tetraloop interactions. PMID:9405377

Design Construction and Operation of a Supercritical Carbon Dioxide (sCO 2) Loop for Investigation of Dry Cooling and Natural Circulation Potential for Use in Advanced Small Modular Reactors Utilizing sCO 2 Power Conversion Cycles.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Middleton, Bobby D.; Rodriguez, Salvador B.; Carlson, Matthew David

This report outlines the work completed for a Laboratory Directed Research and Development project at Sandia National Laboratories from October 2012 through September 2015. An experimental supercritical carbon dioxide (sCO 2 ) loop was designed, built, and o perated. The experimental work demonstrated that sCO 2 can be uti lized as the working fluid in an air - cooled, natural circulation configuration to transfer heat from a source to the ultimate heat sink, which is the surrounding ambient environment in most ca ses. The loop was also operated in an induction - heated, water - cooled configuration that allows formore » measurements of physical parameters that are difficult to isolate in the air - cooled configuration. Analysis included the development of two computational flu id dynamics models. Future work is anticipated to answer questions that were not covered in this project.« less

The influence of nutrients, biliary-pancreatic secretions, and systemic trophic hormones on intestinal adaptation in a Roux-en-Y bypass model.

PubMed

Taqi, Esmaeel; Wallace, Laurie E; de Heuvel, Elaine; Chelikani, Prasanth K; Zheng, Huiyuan; Berthoud, Hans-Rudolph; Holst, Jens J; Sigalet, David L

2010-05-01

The signals that govern the upregulation of nutrient absorption (adaptation) after intestinal resection are not well understood. A Gastric Roux-en-Y bypass (GRYB) model was used to isolate the relative contributions of direct mucosal stimulation by nutrients, biliary-pancreatic secretions, and systemic enteric hormones on intestinal adaptation in short bowel syndrome. Male rats (350-400 g; n = 8/group) underwent sham or GRYB with pair feeding and were observed for 14 days. Weight and serum hormonal levels (glucagon-like peptide-2 [GLP-2], PYY) were quantified. Adaptation was assessed by intestinal morphology and crypt cell kinetics in each intestinal limb of the bypass and the equivalent points in the sham intestine. Mucosal growth factors and expression of transporter proteins were measured in each limb of the model. The GRYB animals lost weight compared to controls and exhibited significant adaptive changes with increased bowel width, villus height, crypt depth, and proliferation indices in the alimentary and common intestinal limbs. Although the biliary limb did not adapt at the mucosa, it did show an increased bowel width and crypt cell proliferation rate. The bypass animals had elevated levels of systemic PYY and GLP-2. At the mucosal level, insulin-like growth factor-1 (IGF-1) and basic fibroblast growth factor (bFGF) increased in all limbs of the bypass animals, whereas keratinocyte growth factor (KGF) and epidermal growth factor (EGF) had variable responses. The expression of the passive transporter of glucose, GLUT-2, expression was increased, whereas GLUT-5 was unchanged in all limbs of the bypass groups. Expression of the active mucosal transporter of glucose, SGLT-1 was decreased in the alimentary limb. Adaptation occurred maximally in intestinal segments stimulated by nutrients. Partial adaptation in the biliary limb may reflect the effects of systemic hormones. Mucosal content of IGF-1, bFGF, and EGF appear to be stimulated by systemic hormones, potentially GLP-2, whereas KGF may be locally regulated. Further studies to examine the relationships between the factors controlling nutrient-induced adaptation are suggested. Direct contact with nutrients appears to be the most potent factor in inducing mucosal adaptation. Copyright (c) 2010 Elsevier Inc. All rights reserved.

Metabolic and neuroendocrine responses to Roux-en-Y gastric bypass. I: energy balance, metabolic changes, and fat loss.

PubMed

Liu, X; Lagoy, A; Discenza, I; Papineau, G; Lewis, E; Braden, G; Romanelli, J; Braun, B; Silva, J E

2012-08-01

Obesity is a major health problem. Effective treatment requires understanding the homeostatic responses to caloric restriction. The aim was to study Roux-en-Y gastric bypass patients longitudinally for 6 months after surgery to identify major factors modulating fat loss. We studied 13 patients (11 females and two males) aged 41.2 ± 2 yr. Mean body mass index was 44.6 ± 1.2 kg/m(2), with 50 ± 1% body fat (58.3 kg). Selection excluded patients with confounding comorbidities or treatments. Caloric intake was reduced 742 ± 82 kcal/d by 1 month and 450 kcal/d between 2 and 4 months postoperatively. By 6 months, relative to baseline, body mass index decreased 24.8 ± 1.1%; percentage body fat, 37.3 ± 3.2% (21.7 kg); fat free mass (FFM), 9.7 ± 1.2%; and resting metabolic rate (RMR), 18.1 ± 4.3%. RMR correlated with FFM at all times (r = 0.71; P < 0.0001), but FFM explained no more than 50% of RMR variance. Exercise capacity (treadmill walking, 53 m/min with increasing grade) improved with time. Mean nonexercise physical activity level was low (1.2, or 20% of RMR), with considerable variance among individuals. Fat loss did not correlate with the aggregate energy deficit or its individual components. Resting or postexercise respiratory exchange ratio (RER) was lowest, whereas plasma β-OH-butyrate and glycerol were highest, between 1 and 2 months after surgery. RER increased linearly with mild exercise, and fat loss correlated positively with physical activity level and RER. Although the ultimate cause for weight loss is the energy deficit, the variance in fat loss correlated with glucose oxidation, suggesting that glucose partition between oxidation (muscle) and storage (adipose tissue) is an important factor affecting fat loss in individuals submitted to Roux-en-Y gastric bypass.

ANALYSIS OF FOOD TOLERANCE IN PATIENTS SUBMITTED TO BARIATRIC SURGERY USING THE QUESTIONNAIRE QUALITY OF ALIMENTATION.

PubMed

Stumpf, Matheo Augusto Morandi; Rodrigues, Marcos Ricardo da Silva; Kluthcovsky, Ana Claudia Garabeli Cavalli; Travalini, Fabiana; Milléo, Fábio Quirillo

2015-01-01

Due to the increased prevalence of obesity in many countries, the number of bariatric surgeries is increasing. They are considered the most effective treatment for obesity. In the postoperative there may be difficulties with the quality of alimentation, tolerance to various types of food, as well as vomiting and regurgitation. Few surveys are available to assess these difficulties in the postoperative. To perform a systematic literature review about food tolerance in patients undergoing bariatric surgery using the questionnaire "Quality of Alimentation", and compare the results between different techniques. A descriptive-exploratory study where the portals Medline and Scielo were used. The following headings were used in english, spanish and portuguese: quality of alimentation, bariatric surgery and food tolerance. A total of 88 references were found, 14 used the questionnaire "Quality of Alimentation" and were selected. In total, 2745 patients were interviewed of which 371 underwent to gastric banding, 1006 to sleeve gastrectomy, 1113 to Roux-en-Y gastric bypass, 14 to biliopancreatic diversion associated with duodenal switch, 83 were non-operated obese, and 158 non-obese patients. The questionnaire showed good acceptability. The biliopancreatic diversion with duodenal switch had the best food tolerance in the postoperative when compared to other techniques, but it was evaluated in a single article with a small sample. The longer the time after the operation, the better is the food tolerance. Comparing the sleeve gastrectomy and the Roux-en-Y gastric bypass, there are still controversial results in the literature. The gastric banding had the worst score of food tolerance among all the techniques evaluated. The questionnaire is easy and fast to assess the food tolerance in patients after bariatric surgery. Biliopancreatic diversion with duodenal switch had the best food tolerance in the postoperative when compared to sleeve gastrectomy and the Roux-en-Y gastric bypass. Gastric banding still remains in controversy, due it presented the worst score.

Protocol for a 1-year prospective, longitudinal cohort study of patients undergoing Roux-en-Y gastric bypass and sleeve gastrectomy: the BARI-LIFESTYLE observational study

PubMed Central

Jassil, Friedrich C; Carnemolla, Alisia; Kingett, Helen; Paton, Bruce; O’Keeffe, Aidan G; Doyle, Jacqueline; Morris, Stephen; Lewis, Neville; Kirk, Amy; Pucci, Andrea; Chaiyasoot, Kusuma; Batterham, Rachel L

2018-01-01

Introduction Roux-en-Y gastric bypass and sleeve gastrectomy are the two most common bariatric surgery performed in the UK that result in comparable weight loss and remission of obesity-associated comorbidities. However, there is a paucity of studies examining the impact of these procedures on body composition, physical activity levels, sedentary behaviour, physical function and strength, dietary intake, health-related quality of life and costs. Methods and analysis The BARI-LIFESTYLE observational study is a 1-year prospective, longitudinal cohort study within a real-world routine clinical care setting aiming to recruit 100 patients with severe obesity undergoing either primary Roux-en-Y gastric bypass or sleeve gastrectomy from two bariatric centres in London, UK. Participants will be followed up four times during the study period; presurgery baseline (T0) and at 3 (T1), 6 (T2) and 12 months (T3) postsurgery. In addition to the standard follow-up investigations, assessments including dual-energy X-ray absorptiometry scan, bioelectric impedance analysis, 6 min walk test, sit-to-stand test and handgrip test will be undertaken together with completion of questionnaires. Physical activity levels and sedentary behaviour will be assessed using accelerometer, and dietary intake will be recorded using a 3-day food diary. Outcome measures will include body weight, body fat mass, lean muscle mass, bone mineral density, physical activity levels, sedentary behaviour, physical function and strength, dietary intake, health-related quality of life, remission of comorbidities, healthcare resource utilisation and costs. Ethics and dissemination This study has been reviewed and given a favourable ethical opinion by London-Dulwich Research Ethics Committee (17/LO/0950). The results will be presented to stakeholder groups locally, nationally and internationally and published in peer-reviewed medical journals. The lay-person summary of the findings will be published on the Centre for Obesity Research, University College London website (http://www.ucl.ac.uk/obesity). PMID:29549212

Pancreatic and Intestinal Function Post Roux-en-Y Gastric Bypass Surgery for Obesity

PubMed Central

O’Keefe, Stephen J D; Rakitt, Tina; Ou, Junhai; El Hajj, Ihab I; Blaney, Elizabeth; Vipperla, Kishore; Holst, Jens-Jules; Rehlfeld, Jens

2017-01-01

Objectives: Despite the fact that the most effective treatment for morbid obesity today is gastric bypass surgery, some patients develop life-threatening nutritional complications associated with their weight loss. Methods: Here we examine the influence of the altered anatomy and digestive physiology on pancreatic secretion and fat absorption. Thirteen post Roux-en-Y gastric bypass (RYGB) patients who had lost >100 lbs in the first year following surgery and who gave variable histories of gastrointestinal (GI) dysfunction, were selected for study. Food-stimulated pancreatic enzyme secretion and GI hormone responses were measured during 2 h perfusions of the Roux limb with a standard polymeric liquid formula diet and polyethylene glycol marker, with collections of secretions from the common channel distal to the anastomosis and blood testing. Fat absorption was then measured during a 72 h balance study when a normal diet was given containing ~100 g fat/d. Results: Result showed that all patients had some fat malabsorption, but eight had coefficients of fat absorption <80%, indicative of steatorrhea. This was associated with significantly lower feed-stimulated secretion rates of trypsin, amylase, and lipase, and higher plasma peptide-YY concentrations compared with healthy controls. Five steatorrhea patients were subsequently treated with low quantities of pancreatic enzyme supplements for 3 months, and then retested. The supplements were well tolerated, and fat absorption improved in four of five patients accompanied by an increase in lipase secretion, but body weight increased in only three. Postprandial breath hydrogen concentrations were elevated with some improvement following enzyme supplementation suggesting persistent bacterial overgrowth and decreased colonic fermentation. Conclusions: Our investigations revealed a wide spectrum of gastrointestinal abnormalities, including fat malabsorption, impaired food stimulated pancreatic secretion, ileal brake stimulation, and bacterial overgrowth, in patients following RYGB which could be attributed to the breakdown of the normally highly orchestrated digestive anatomy and physiology. PMID:28771242

Treatment of late identified iatrogenic injuries of the right and left hepatic duct after laparoscopic cholecystectomy without transhepatic stent and Witzel drainage: Case report.

PubMed

Rifatbegovic, Zijah; Kovacevic, Maja; Nikic, Branka

2018-05-26

Most of the case reports about high type iatrogenic hepatic duct injuries reports how to treat and make Roux-en-Y hepaticojejunostomy below the junction of the liver immediately after this condition is recognised during surgical procedure when the injury was made. Hereby we present a case where we made Roux-en-Y hepaticojejunostomy without transhepatic billiary stent and also without Witzel drainage one month after the iatrogenic injury. A 21-year-old woman suffered from iatrogenic high transectional lesion of both hepatic ducts during laparoscopic cholecystectomy in a local hospital. Iatrogenic injury was not immediately recognized. Ten days later due to patient complaints and large amount of bile in abdominal drain sac, second surgery was performed to evacuate biloma. Symptoms reappeared again, together with bile in abdominal sac, and then patient was sent to our Clinical Center. After performing additional diagnostics, high type (Class E) of iatrogenic hepatic duct injury was diagnosed. A revision surgical procedure was performed. During the exploration we found high transection lesion of right and left hepatic duct, and we decided to do Roux-en-Y hepaticojejunostomy. We created a part of anastomosis between the jejunum and liver capsule with polydioxanone suture (PDS) 4-0 because of poor quality of the remaining parts of the hepatic ducts. We made two separate hepaticojejunal anastomoses (left and right) that we partly connected to the liver capsule, where we had a defect of hepatic ducts, without Witzel enterostomy and transhepatic biliary stent. There were no significant postoperative complications. Magnetic resonance cholangiopancreatography (MRCP) was made one year after the surgical procedure, which showed the proper width of the intrahepatic bile ducts, with no signs of stenosis of anastomoses. In most cases, treatment iatrogenic BDI is based on primary repair of the duct, ductal repair with a stent or creating duct-enteric anastomosis, often used and drainage by Witzel (Witzel enterostomy). Reconstructive hepaticojejunostomy is recommended for major BDIs during cholecystectomy. Considering that the biliary reconstruction with Roux-en-Y hepatojejunostomy is usually made with transhepatic biliary stent or Witzel enterostomy. What is interesting about this case is that these types of drainages were not made. We tried and managed to avoid such types of drainage and proved that in this way, without those types of drainage, we can successfully do duplex hepaticojejunal anastomoses and that they can survive without complications. Our case indicates that this approach can be successfully used for surgical repair of iatrogenic lesion of both hepatic ducts. Copyright © 2018. Published by Elsevier Ltd.

Magnetic Memory from Site Isolated Dy(III) on Silica Materials

PubMed Central

2017-01-01

Achieving magnetic remanence at single isolated metal sites dispersed at the surface of a solid matrix has been envisioned as a key step toward information storage and processing in the smallest unit of matter. Here, we show that isolated Dy(III) sites distributed at the surface of silica nanoparticles, prepared with a simple and scalable two-step process, show magnetic remanence and display a hysteresis loop open at liquid 4He temperature, in contrast to the molecular precursor which does not display any magnetic memory. This singular behavior is achieved through the controlled grafting of a tailored Dy(III) siloxide complex on partially dehydroxylated silica nanoparticles followed by thermal annealing. This approach allows control of the density and the structure of isolated, “bare” Dy(III) sites bound to the silica surface. During the process, all organic fragments are removed, leaving the surface as the sole ligand, promoting magnetic remanence. PMID:28386602

Magnetic memory from site isolated Dy(III) on silica materials

DOE Office of Scientific and Technical Information (OSTI.GOV)

Allouche, Florian; Lapadula, Giuseppe; Siddiqi, Georges

Achieving magnetic remanence at single isolated metal sites dispersed at the surface of a solid matrix has been envisioned as a key step toward information storage and processing in the smallest unit of matter. Here, we show that isolated Dy(III) sites distributed at the surface of silica nanoparticles, prepared with a simple and scalable two-step process, show magnetic remanence and display a hysteresis loop open at liquid 4He temperature, in contrast to the molecular precursor which does not display any magnetic memory. This singular behavior is achieved through the controlled grafting of a tailored Dy(III) siloxide complex on partially dehydroxylatedmore » silica nanoparticles followed by thermal annealing. This approach allows control of the density and the structure of isolated, “bare” Dy(III) sites bound to the silica surface. Throughout the process, all organic fragments are removed, leaving the surface as the sole ligand, promoting magnetic remanence.« less

Magnetic memory from site isolated Dy(III) on silica materials

DOE PAGES

Allouche, Florian; Lapadula, Giuseppe; Siddiqi, Georges; ...

2017-02-22

Achieving magnetic remanence at single isolated metal sites dispersed at the surface of a solid matrix has been envisioned as a key step toward information storage and processing in the smallest unit of matter. Here, we show that isolated Dy(III) sites distributed at the surface of silica nanoparticles, prepared with a simple and scalable two-step process, show magnetic remanence and display a hysteresis loop open at liquid 4He temperature, in contrast to the molecular precursor which does not display any magnetic memory. This singular behavior is achieved through the controlled grafting of a tailored Dy(III) siloxide complex on partially dehydroxylatedmore » silica nanoparticles followed by thermal annealing. This approach allows control of the density and the structure of isolated, “bare” Dy(III) sites bound to the silica surface. Throughout the process, all organic fragments are removed, leaving the surface as the sole ligand, promoting magnetic remanence.« less

Umbilical Stiffness Matrix Characterization and Testing for Microgravity Science Payloads

NASA Technical Reports Server (NTRS)

Engberg, Robert C.

2003-01-01

This paper describes efforts of testing and analysis of various candidate cables and umbilicals for International Space Station microgravity science payloads. The effects of looping, large vs. small displacements, and umbilical mounting configurations were assessed. A 3-DOF stepper motor driven fixture was used to excite the umbilicals. Forces and moments were directly measured in all three axes with a 6-DOF load cell in order to derive suitable stiffness matrices for design and analysis of vibration isolation controllers. Data obtained from these tests were used to help determine the optimum type and configuration of umbilical cables for the International Space Station microgravity science glovebox (MSG) vibration isolation platform. The data and procedures can also be implemented into control algorithm simulations to assist in validation of actively controlled vibration isolation systems. The experimental results of this work are specific in support of the Glovebox Integrated Microgravity Isolation Technology (g-LIMIT) isolation platform, to be located in the microgravity science glovebox aboard the U.S. Destiny Laboratory Module.

Microgravity isolation system design: A modern control analysis framework

NASA Technical Reports Server (NTRS)

Hampton, R. D.; Knospe, C. R.; Allaire, P. E.; Grodsinsky, C. M.

1994-01-01

Many acceleration-sensitive, microgravity science experiments will require active vibration isolation from the manned orbiters on which they will be mounted. The isolation problem, especially in the case of a tethered payload, is a complex three-dimensional one that is best suited to modern-control design methods. These methods, although more powerful than their classical counterparts, can nonetheless go only so far in meeting the design requirements for practical systems. Once a tentative controller design is available, it must still be evaluated to determine whether or not it is fully acceptable, and to compare it with other possible design candidates. Realistically, such evaluation will be an inherent part of a necessary iterative design process. In this paper, an approach is presented for applying complex mu-analysis methods to a closed-loop vibration isolation system (experiment plus controller). An analysis framework is presented for evaluating nominal stability, nominal performance, robust stability, and robust performance of active microgravity isolation systems, with emphasis on the effective use of mu-analysis methods.

Mammalian DNA enriched for replication origins is enriched for snap-back sequences.

PubMed

Zannis-Hadjopoulos, M; Kaufmann, G; Martin, R G

1984-11-15

Using the instability of replication loops as a method for the isolation of double-stranded nascent DNA, extruded DNA enriched for replication origins was obtained and denatured. Snap-back DNA, single-stranded DNA with inverted repeats (palindromic sequences), reassociates rapidly into stem-loop structures with zero-order kinetics when conditions are changed from denaturing to renaturing, and can be assayed by chromatography on hydroxyapatite. Origin-enriched nascent DNA strands from mouse, rat and monkey cells growing either synchronously or asynchronously were purified and assayed for the presence of snap-back sequences. The results show that origin-enriched DNA is also enriched for snap-back sequences, implying that some origins for mammalian DNA replication contain or lie near palindromic sequences.

A real-time simulator of a turbofan engine

NASA Technical Reports Server (NTRS)

Litt, Jonathan S.; Delaat, John C.; Merrill, Walter C.

1989-01-01

A real-time digital simulator of a Pratt and Whitney F100 engine has been developed for real-time code verification and for actuator diagnosis during full-scale engine testing. This self-contained unit can operate in an open-loop stand-alone mode or as part of closed-loop control system. It can also be used for control system design and development. Tests conducted in conjunction with the NASA Advanced Detection, Isolation, and Accommodation program show that the simulator is a valuable tool for real-time code verification and as a real-time actuator simulator for actuator fault diagnosis. Although currently a small perturbation model, advances in microprocessor hardware should allow the simulator to evolve into a real-time, full-envelope, full engine simulation.

Note: A dual temperature closed loop batch reactor for determining the partitioning of trace gases within CO2-water systems.

PubMed

Warr, Oliver; Rochelle, Christopher A; Masters, Andrew J; Ballentine, Christopher J

2016-01-01

An experimental approach is presented which can be used to determine partitioning of trace gases within CO2-water systems. The key advantages of this system are (1) The system can be isolated with no external exchange, making it ideal for experiments with conservative tracers. (2) Both phases can be sampled concurrently to give an accurate composition at each phase at any given time. (3) Use of a lower temperature flow loop outside of the reactor removes contamination and facilitates sampling. (4) Rapid equilibration at given pressure/temperature conditions is significantly aided by stirring and circulating the water phase using a magnetic stirrer and high-pressure liquid chromatography pump, respectively.

THE CONTEXTUAL EFFECT OF THE PREVALENCE OF LIQOUR STORES AND BARS ON INTAKE OF HARD LIQOUR

EPA Science Inventory

The Contextual Effect of the Prevalence of Liquor Stores and Bars on Intake of Hard Liquor

Kimberly B. Morland PhD?, Steve Wing PhD?, Ana Diez Roux MD PhD?

?Department of Epidemiology, University of North Carolina, Chapel Hill, NC; ?The Department of Epidemiology an...

A Phenomenological Study of Vocational Experiences in Adult College Graduates with Autism Spectrum Disorders

ERIC Educational Resources Information Center

Lizotte, Michelle Cora

2016-01-01

Individuals with autism spectrum disorder (ASD) remain unemployed and underemployed at greater rates than individuals in all other disability groups (Shattuck et al., 2012; Roux et al., 2013). It is well documented that competitive employment outcomes for adults with ASD are poor when compared not only to the general population but also when…

Type Theory, Computation and Interactive Theorem Proving

DTIC Science & Technology

2015-09-01

postdoc Cody Roux, to develop new methods of verifying real-valued inequalities automatically. They developed a prototype implementation in Python [8] (an...he has developed new heuristic, geometric methods of verifying real-valued inequalities. A python -based implementation has performed surprisingly...express complex mathematical and computational assertions. In this project, Avigad and Harper developed type-theoretic algorithms and formalisms that

[Reconstructive surgery in iatrogenic bile duct injuries].

PubMed

Krawczyk, M; Kania, M; Zieniewicz, K; Nyckowski, P; Patkowski, W; Karwowski, A

1997-01-01

The paper presents the results of surgical treatment performed in 54 patients with iatrogenic injury of biliary tract. All cases of injury were made during open and laparoscopic cholecystectomy. We concluded that Roux-en-Y hepatico-jejunostomy should be recommended. There were no deaths after surgery. This technic was successful therapeutic management more than 95% of cases.

Multiple injection mode with or without repeated sample injections: Strategies to enhance productivity in countercurrent chromatography.

PubMed

Müller, Marco; Wasmer, Katharina; Vetter, Walter

2018-06-29

Countercurrent chromatography (CCC) is an all liquid based separation technique typically used for the isolation and purification of natural compounds. The simplicity of the method makes it easy to scale up CCC separations from analytical to preparative and even industrial scale. However, scale-up of CCC separations requires two different instruments with varying coil dimensions. Here we developed two variants of the CCC multiple injection mode as an alternative to increase the throughput and enhance productivity of a CCC separation when using only one instrument. The concept is based on the parallel injection of samples at different points in the CCC column system and the simultaneous separation using one pump only. The wiring of the CCC setup was modified by the insertion of a 6-port selection valve, multiple T-pieces and sample loops. Furthermore, the introduction of storage sample loops enabled the CCC system to be used with repeated injection cycles. Setup and advantages of both multiple injection modes were shown by the isolation of the furan fatty acid 11-(3,4-dimethyl-5-pentylfuran-2-yl)-undecanoic acid (11D5-EE) from an ethyl ester oil rich in 4,7,10,13,16,19-docosahexaenoic acid (DHA-EE). 11D5-EE was enriched in one step from 1.9% to 99% purity. The solvent consumption per isolated amount of analyte could be reduced by ∼40% compared to increased throughput CCC and by ∼5% in the repeated multiple injection mode which also facilitated the isolation of the major compound (DHA-EE) in the sample. Copyright © 2018 Elsevier B.V. All rights reserved.

Development of "ultrasound-assisted dynamic extraction" and its combination with CCC and CPC for simultaneous extraction and isolation of phytochemicals.

PubMed

Zhang, Yuchi; Liu, Chunming; Li, Jing; Qi, Yanjuan; Li, Yuchun; Li, Sainan

2015-09-01

A new method for the extraction of medicinal herbs termed ultrasonic-assisted dynamic extraction (UADE) was designed and evaluated. This technique was coupled with counter-current chromatography (CCC) and centrifugal partition chromatography (CPC) and then applied to the continuous extraction and online isolation of chemical constituents from Paeonia lactiflora Pall (white peony) roots. The mechanical parameters, including the pitch and diameter of the shaft, were optimized by means of mathematical modeling. Furthermore, the configuration and mechanism of online UADE coupled with CCC and CPC were elaborated. The stationary phases of the two-phase solvent systems from CCC and CPC were utilized as the UADE solution. The extraction solution was pumped into the sample loop and then introduced into the CCC column; the target compounds were eluted with the lower aqueous phase of the two-phase solvent system. During the CCC separation, the extraction solution was continuously fed in the sample loop by turning the ten-port valve; the extraction solution was then pumped into the CPC column and eluted by the mobile phase of the two-phase solvent system mentioned above. When the first cycle of the UADE/CCC/CPC was completed, the second cycle experiment could be carried out, and so on. Four target compounds (albiflorin, benzoylpaeoniflorin, paeoniflorin, and galloylpaeoniflorin) with purities above 94.96% were successfully extracted and isolated online using the two-phase solvent system comprising ethyl acetate-n-butanol-ethanol-water (1:3.5:2:4.5, v/v/v/v). Compared with conventional extraction methods, the instrumental setup of the present method offers the advantages of automation and systematic extraction and isolation of natural products. Crown Copyright © 2015. Published by Elsevier B.V. All rights reserved.

A programmable broadband low frequency active vibration isolation system for atom interferometry.

PubMed

Tang, Biao; Zhou, Lin; Xiong, Zongyuan; Wang, Jin; Zhan, Mingsheng

2014-09-01

Vibration isolation at low frequency is important for some precision measurement experiments that use atom interferometry. To decrease the vibrational noise caused by the reflecting mirror of Raman beams in atom interferometry, we designed and demonstrated a compact stable active low frequency vibration isolation system. In this system, a digital control subsystem is used to process and feedback the vibration measured by a seismometer. A voice coil actuator is used to control and cancel the motion of a commercial passive vibration isolation platform. With the help of field programmable gate array-based control subsystem, the vibration isolation system performed flexibly and accurately. When the feedback is on, the intrinsic resonance frequency of the system will change from 0.8 Hz to about 0.015 Hz. The vertical vibration (0.01-10 Hz) measured by the in-loop seismometer is reduced by an additional factor of up to 500 on the basis of a passive vibration isolation platform, and we have proved the performance by adding an additional seismometer as well as applying it in the atom interferometry experiment.

Multistage position-stabilized vibration isolation system for neutron interferometry

NASA Astrophysics Data System (ADS)

Arif, Muhammad; Brown, Dennis E.; Greene, Geoffrey L.; Clothier, R.; Littrell, K.

1994-10-01

A two stage, position stabilized vibration isolation system has been constructed and is now in operation at the Cold Neutron Research Facility of the National Institute of Standards and Technology, Gaithersburg, MD. The system employs pneumatic isolators with a multiple input/multiple output pneumatic servo system based upon pulse width modulation control loops. The first stage consists of a 40,000 kg reinforced concrete table supported by pneumatic isolators. A large environmentally isolated laboratory enclosure rests on the concrete table. The second stage consists of a 3000 kg granite optical table located within the enclosure and supported by another set of pneumatic isolators. The position of the two stages is monitored by proximity sensors and inclinometers with 12 degrees of freedom. The system controls 12 independent pneumatic airsprings. The signals from these sensors are fed into a personal computer based control system. The control system has maintained the position of the two stages to better than 1 micrometers in translation and 5 (mu) rad in orientation for a period of a few months. A description of the system and its characteristics is given.

Preservation of duodenal passage as a determinant of short- and long-term quality of life in gastric cancer patients after total gastrectomy.

PubMed

Olesiński, Tomasz; Szpakowski, Marek; Saramak, Piotr; Rutkowski, Andrzej; Jeziorski, Krzysztof

2017-10-01

The aim of this prospective study was to compare subjective and objective quality of life (QoL) of gastric cancer patients after total gastrectomy with and without preservation of the duodenal passage during short- and long-term follow-up. The study included 68 patients, among them 37 (54%) persons subjected to total gastrectomy with Roux-Y reconstruction (R-Y group) and 31 (46%) individuals in whom gastrectomy was followed by formation of Henley-Longmire loop (H-L group). Subjective and objective QoL was determined 1 and 10 years postsurgery. During each visit, subjective QoL was determined with EORTC QLQ-C30 questionnaire, along with markers of nutritional status and self-reported incidence of symptoms specific to postgastrectomy syndrome. The two groups did not differ significantly in terms of their subjective QoL and markers of nutritional status at 1 and 10 years postsurgery, and none of these parameters underwent significant changes between the first and second evaluation. Patients from R-Y group reported subjective weight loss significantly more often during both visits, and individuals from H-L group significantly more often complained on postprandial diarrhea during long-term follow-up. Moreover, both groups showed an increase in the incidence of postprandial vomiting between the first and second evaluation. QoL of gastric cancer patients subjected to total gastrectomy stabilizes at relatively high level within a year from the surgery. Preservation of the duodenal passage does not exert a beneficial effect on both objective and subjective QoL after total gastrectomy.

Automated stopped-in-dual-loop flow analysis system for catalytic determination of vanadium in drinking water.

PubMed

Teshima, Norio; Kuno, Masami; Ueda, Minoru; Ueda, Hisashi; Ohno, Shinsuke; Sakai, Tadao

2009-07-15

An automated stopped-in-dual-loop flow analysis (SIDL-FA) system is proposed for the determination of vanadium in drinking water. The chemistry is based on the vanadium-catalyzed oxidation reaction of p-anisidine by bromate in the presence of Tiron as an activator to produce a dye (lambda(max)=510 nm). A SIDL-FA system basically consists of a selection valve, three pumps (one is for delivering of standard/sample, and others are for reagents), two six-way injection valves, a spectrophotometric detector and a data acquisition device. A 100-microL coiled loop around a heated device is fitted onto each six-way injection valve. A well-mixed solution containing reagents and standard/sample is loaded into the first loop on a six-way valve, and then the same solution is loaded into the second loop on another six-way valve. The solutions are isolated by switching these two six-way valves, so that the catalytic reaction can be promoted. The net waste can be zero in this stage, because all pumps are turned off. Then each resulting solution is dispensed to the detector with suitable time lag. A touchscreen controller is developed to automatically carry out the original SIDL-FA protocol. The proposed SIDL-FA method allows vanadium to be quantified in the range of 0.1-2 microg L(-1) and is applied to the determination of vanadium in drinking water samples.

Design of Test Loops for Forced Convection Heat Transfer Studies at Supercritical State

NASA Astrophysics Data System (ADS)

Balouch, Masih N.

Worldwide research is being conducted to improve the efficiency of nuclear power plants by using supercritical water (SCW) as the working fluid. One such SCW reactor considered for future development is the CANDU-Supercritical Water Reactor (CANDU-SCWR). For safe and accurate design of the CANDU-SCWR, a detailed knowledge of forced-convection heat transfer in SCW is required. For this purpose, two supercritical fluid loops, i.e. a SCW loop and an R-134a loop are developed at Carleton University. The SCW loop is designed to operate at pressures as high as 28 MPa, temperatures up to 600 °C and mass fluxes of up to 3000 kg/m2s. The R-134a loop is designed to operate at pressures as high as 6 MPa, temperatures up to 140 °C and mass fluxes in the range of 500-6000 kg/m2s. The test loops designs allow for up to 300 kW of heating power to be imparted to the fluid. Both test loops are of the closed-loop design, where flow circulation is achieved by a centrifugal pump in the SCW loop and three parallel-connected gear pumps in the R-134a loop, respectively. The test loops are pressurized using a high-pressure nitrogen cylinder and accumulator assembly, which allows independent control of the pressure, while simultaneously dampening pump induced pressure fluctuations. Heat exchangers located upstream of the pumps control the fluid temperature in the test loops. Strategically located measuring instrumentation provides information on the flow rate, pressure and temperature in the test loops. The test loops have been designed to accommodate a variety of test-section geometries, ranging from a straight circular tube to a seven-rod bundle, achieving heat fluxes up to 2.5 MW/m2 depending on the test-section geometry. The design of both test loops allows for easy reconfiguration of the test-section orientation relative to the gravitational direction. All the test sections are of the directly-heated design, where electric current passing through the pressure retaining walls of the test sections provides the Joule heating required to heat up the fluid to supercritical conditions. A high-temperature dielectric gasket isolates the current carrying parts of the test section from the rest of the assembly. Temperature and pressure drop data are collected at the inlet and outlet, and along the heated length of the test section. The test loops and test sections are designed according to American Society of Mechanical Engineers (ASME) Pressure Piping B31.1, and Boiler and Pressure Vessel Code, Section VIII-Division 1 rules. The final test loops and test sections assemblies are certified by Technical Standards and Safety Authority (TSSA). Every attempt is made to use off-the-shelf components where possible in order to streamline the design process and reduce costs. Following a rigorous selection process, stainless steel Types 316 and 316H are selected as the construction materials for the test loops, and Inconel 625 is selected as the construction material for the test sections. This thesis describes the design of the SCW and R-134a loops along with the three test-section geometries (i.e., tubular, annular and bundle designs).

C-band radar pulse Doppler error: Its discovery, modeling, and elimination

NASA Technical Reports Server (NTRS)

Krabill, W. B.; Dempsey, D. J.

1978-01-01

The discovery of a C Band radar pulse Doppler error is discussed and use of the GEOS 3 satellite's coherent transponder to isolate the error source is described. An analysis of the pulse Doppler tracking loop is presented and a mathematical model for the error was developed. Error correction techniques were developed and are described including implementation details.

Arcjet power supply and start circuit

NASA Technical Reports Server (NTRS)

Gruber, Robert P. (Inventor)

1988-01-01

A dc power supply for spacecraft arcjet thrusters has an integral automatic starting circuit and an output averaging inductor. The output averaging inductor, in series with the load, provides instantaneous current control, and ignition pulse and an isolated signal proportional to the arc voltage. A pulse width modulated converter, close loop configured, is also incorporated to give fast response output current control.

Loss of a single N-linked glycan allows CD4-independent human immunodeficiency virus type 1 infection by altering the position of the gp120 V1/V2 variable loops.

PubMed

Kolchinsky, P; Kiprilov, E; Bartley, P; Rubinstein, R; Sodroski, J

2001-04-01

The gp120 envelope glycoprotein of primary human immunodeficiency virus type 1 (HIV-1) promotes virus entry by sequentially binding CD4 and the CCR5 chemokine receptor on the target cell. Previously, we adapted a primary HIV-1 isolate, ADA, to replicate in CD4-negative canine cells expressing human CCR5. The gp120 changes responsible for CD4-independent replication were limited to the V2 loop-V1/V2 stem. Here we show that elimination of a single glycosylation site at asparagine 197 in the V1/V2 stem is sufficient for CD4-independent gp120 binding to CCR5 and for HIV-1 entry into CD4-negative cells expressing CCR5. Deletion of the V1/V2 loops also allowed CD4-independent viral entry and gp120 binding to CCR5. The binding of the wild-type ADA gp120 to CCR5 was less dependent upon CD4 at 4 degrees C than at 37 degrees C. In the absence of the V1/V2 loops, neither removal of the N-linked carbohydrate at asparagine 197 nor lowering of the temperature increased the CD4-independent phenotypes. A CCR5-binding conformation of gp120, achieved by CD4 interaction or by modification of temperature, glycosylation, or variable loops, was preferentially recognized by the monoclonal antibody 48d. These results suggest that the CCR5-binding region of gp120 is occluded by the V1/V2 variable loops, the position of which can be modulated by temperature, CD4 binding, or an N-linked glycan in the V1/V2 stem.

Analytical interferences of mercuric chloride preservative in environmental water samples: Determination of organic compounds isolated by continuous liquid-liquid extraction or closed-loop stripping

USGS Publications Warehouse

Foreman, W.T.; Zaugg, S.D.; Falres, L.M.; Werner, M.G.; Leiker, T.J.; Rogerson, P.F.

1992-01-01

Analytical interferences were observed during the determination of organic compounds in groundwater samples preserved with mercuric chloride. The nature of the interference was different depending on the analytical isolation technique employed. (1) Water samples extracted with dichloromethane by continuous liquid-liquid extraction (CLLE) and analyzed by gas chromatography/mass spectrometry revealed a broad HgCl2 'peak' eluting over a 3-5-min span which interfered with the determination of coeluting organic analytes. Substitution of CLLE for separatory funnel extraction in EPA method 508 also resulted in analytical interferences from the use of HgCl2 preservative. (2) Mercuric chloride was purged, along with organic contaminants, during closed-loop stripping (CLS) of groundwater samples and absorbed onto the activated charcoal trap. Competitive sorption of the HgCl2 by the trap appeared to contribute to the observed poor recoveries for spiked organic contaminants. The HgCl2 was not displaced from the charcoal with the dichloromethane elution solvent and required strong nitric acid to achieve rapid, complete displacement. Similar competitive sorption mechanisms might also occur in other purge and trap methods when this preservative is used.

Quantifying the ice-albedo feedback through decoupling

NASA Astrophysics Data System (ADS)

Kravitz, B.; Rasch, P. J.

2017-12-01

The ice-albedo feedback involves numerous individual components, whereby warming induces sea ice melt, inducing reduced surface albedo, inducing increased surface shortwave absorption, causing further warming. Here we attempt to quantify the sea ice albedo feedback using an analogue of the "partial radiative perturbation" method, but where the governing mechanisms are directly decoupled in a climate model. As an example, we can isolate the insulating effects of sea ice on surface energy and moisture fluxes by allowing sea ice thickness to change but fixing Arctic surface albedo, or vice versa. Here we present results from such idealized simulations using the Community Earth System Model in which individual components are successively fixed, effectively decoupling the ice-albedo feedback loop. We isolate the different components of this feedback, including temperature change, sea ice extent/thickness, and air-sea exchange of heat and moisture. We explore the interactions between these different components, as well as the strengths of the total feedback in the decoupled feedback loop, to quantify contributions from individual pieces. We also quantify the non-additivity of the effects of the components as a means of investigating the dominant sources of nonlinearity in the ice-albedo feedback.

Lateral vibration control of a precise machine using magneto-rheological mounts featuring multiple directional damping effect

NASA Astrophysics Data System (ADS)

Kim, Hyung Tae; Jeong, An Mok; Kim, Hyo Young; An, Jong Wook; Kim, Cheol Ho; Jin, Kyung Chan; Choi, Seung-Bok

2018-03-01

In a previous work, magneto-rheological (MR) dampers were originally designed and implemented for reducing the vertical low-frequency vibration occurring in precise semi-conductor manufacturing equipment. To reduce the vibrations, an isolator levitated the manufacturing machine from the floor using pneumatic pressure which cut off the external vibration, while the MR damper was used to decrease the transient response of the isolator. However, it has been found that the MR damper also provides a damping effect on the lateral vibration induced by the high-speed plane motions. Therefore, in this work both vertical and lateral vibrations are controlled using the yield and shear stresses of the lateral directions generated from the MR fluids by applying a magnetic field. After deriving a vibration control model, an overall control logic is formulated considering both vertical and lateral vibrations. In this control strategy, a feedback loop associated with the laser sensor is used for vertical vibration control, while a feed-forward loop with the motion information is used for lateral vibration control. The experimental results show that the proposed concept is highly effective for lateral vibration control using the damping effect on multiple directions.

CHMP6 and VPS4A mediate recycling of Ras to the plasma membrane to promote growth factor signaling

PubMed Central

Zheng, Ze-Yi; Cheng, Chiang-Min; Fu, Xin-Rong; Chen, Liuh-Yow; Xu, Lizhong; Terrillon, Sonia; Wong, Stephen T.; Bar-Sagi, Dafna; Songyang, Zhou; Chang, Eric C.

2011-01-01

While Ras is well-known to function on the plasma membrane (PM) to mediate growth factor signaling, increasing evidence suggests that Ras has complex roles in the cytoplasm. To uncover these roles, we screened a cDNA library and isolated H-Ras-binding proteins that also influence Ras functions. Many isolated proteins regulate trafficking involving endosomes; CHMP6/VPS20 and VPS4A, which interact with ESCRT-III, were chosen for further study. We showed that the binding is direct and occurs in endosomes. Furthermore, the binding is most efficient when H-Ras has a functional effector-binding-loop and is GTP-bound and ubiquitylated. CHMP6 and VPS4A also bound N-Ras, but not K-Ras. Repressing CHMP6 and VPS4A blocked Ras-induced transformation, which correlated with inefficient Ras localization to the PM as measured by cell fractionation and photobleaching. Moreover, silencing CHMP6 and VPS4A also blocked EGFR recycling. These data suggest that Ras interacts with key ESCRT-III components to promote recycling of itself and EGFR back to the PM to create a positive feedback loop to enhance growth factor signaling. PMID:22231449

Development and application of loop-mediated isothermal amplification for detection of the F167Y mutation of carbendazim-resistant isolates in Fusarium graminearum

PubMed Central

Duan, Yabing; Zhang, Xiaoke; Ge, Changyan; Wang, Yong; Cao, Junhong; Jia, Xiaojing; Wang, Jianxin; Zhou, Mingguo

2014-01-01

Resistance of Fusarium graminearum to carbendazim is caused by point mutations in the β2-tubulin gene. The point mutation at codon 167 (TTT → TAT, F167Y) occurs in more than 90% of field resistant isolates in China. To establish a suitable method for rapid detection of the F167Y mutation in F. graminearum, an efficient and simple method with high specificity was developed based on loop-mediated isothermal amplification (LAMP). A set of four primers was designed and optimized to specially distinguish the F167Y mutation genotype. The LAMP reaction was optimal at 63°C for 60 min. When hydroxynaphthol blue dye (HNB) was added prior to amplification, samples with DNA of the F167Y mutation developed a characteristic sky blue color after the reaction but those without DNA or with different DNA did not. Results of HNB staining method were reconfirmed by gel electrophoresis. The developed LAMP had good specificity, stability and repeatability and was suitable for monitoring carbendazim-resistance populations of F. graminearum in agricultural production. PMID:25403277

Detection of Goss's Wilt Pathogen Clavibacter michiganensis subsp. nebraskensis in Maize by Loop-Mediated Amplification.

PubMed

Yasuhara-Bell, Jarred; de Silva, Asoka; Heuchelin, Scott A; Chaky, Jennifer L; Alvarez, Anne M

2016-03-01

The Goss's wilt pathogen, Clavibacter michiganensis subsp. nebraskensis, can cause considerable losses in maize (Zea mays) production. Diagnosis of Goss's wilt currently is based on symptomology and identification of C. michiganensis subsp. nebraskensis, following isolation on a semiselective medium and/or serological testing. In an effort to provide a more efficient identification method, a loop-mediated amplification (LAMP) assay was developed to detect the tripartite ATP-independent periplasmic (TRAP)-type C4-dicarboxylate transport system large permease component and tested using strains of C. michiganensis subsp. nebraskensis, all other C. michiganensis subspecies and several genera of nontarget bacteria. Only strains of C. michiganensis subsp. nebraskensis reacted positively with the LAMP assay. The LAMP assay was then used to identify bacterial isolates from diseased maize. 16S rDNA and dnaA sequence analyses were used to confirm the identity of the maize isolates and validate assay specificity. The Cmm ImmunoStrip assay was included as a presumptive identification test of C. michiganensis subsp. nebraskensis at the species level. The Cmn-LAMP assay was further tested using symptomatic leaf tissue. The Cmn-LAMP assay was run in a hand-held real-time monitoring device (SMART-DART) and performed equally to in-lab quantitative polymerase chain reaction equipment. The Cmn-LAMP assay accurately identified C. michiganensis subsp. nebraskensis and has potential as a field test. The targeted sequence also has potential application in other molecular detection platforms.

Novel Human Adenovirus Causing Nosocomial Epidemic Keratoconjunctivitis▿

PubMed Central

Ishiko, Hiroaki; Shimada, Yasushi; Konno, Tsunetada; Hayashi, Akio; Ohguchi, Takeshi; Tagawa, Yoshitsugu; Aoki, Koki; Ohno, Shigeaki; Yamazaki, Shudo

2008-01-01

In 2000, we encountered cases of nosocomial infections with epidemic keratoconjunctivitis (EKC) at a university hospital in Kobe, in the western part of Japan. Two human adenovirus (HAdV) strains, Kobe-H and Kobe-S, were isolated from patients with nosocomial EKC infection. They were untypeable by existing neutralizing antisera; however, the isolate was neutralized with homologous antisera. We then encountered several cases of EKC due to nosocomial infections in eye clinics in different parts of Japan. A total of 80 HAdVs were isolated from patients with EKC at eight different hospitals. The partial hexon gene sequences of the isolates were determined and compared to those of the prototype strains of 51 serotypes. All isolates had identical partial hexon nucleotide sequences. Phylogenetic analysis classified these isolates into species of HAdV-D. The isolates showed 93.9 to 96.7% nucleotide identity with HAdV-D prototype strains, while all 32 HAdV-D prototype strains ranged from 93.2 to 99.2% identity. The sequences of the loop 2 and fiber knob regions from the representative strain, Kobe-H, were dissimilar in all prototype strains of 51 serotypes. We believe that this virus is a novel serotype of HAdV that causes EKC. PMID:18385435

Impact of lipopolysaccharide-induced acute inflammation on baroreflex-controlled sympathetic arterial pressure regulation

PubMed Central

Tohyama, Takeshi; Kawada, Toru; Kishi, Takuya; Yoshida, Keimei; Nishikawa, Takuya; Mannoji, Hiroshi; Kamada, Kazuhiro; Sunagawa, Kenji; Tsutsui, Hiroyuki

2018-01-01

Background Lipopolysaccharide (LPS) induces acute inflammation, activates sympathetic nerve activity (SNA) and alters hemodynamics. Since the arterial baroreflex is a negative feedback system to stabilize arterial pressure (AP), examining the arterial baroreflex function is a prerequisite to understanding complex hemodynamics under LPS challenge. We investigated the impact of LPS-induced acute inflammation on SNA and AP regulation by performing baroreflex open-loop analysis. Methods Ten anesthetized Sprague-Dawley rats were used. Acute inflammation was induced by an intravenous injection of LPS (60 μg/kg). We isolated the carotid sinuses from the systemic circulation and controlled carotid sinus pressure (CSP) by a servo-controlled piston pump. We matched CSP to AP to establish the baroreflex closed-loop condition, whereas we decoupled CSP from AP to establish the baroreflex open-loop condition and changed CSP stepwise to evaluate the baroreflex open-loop function. We recorded splanchnic SNA and hemodynamic parameters under baroreflex open- and closed-loop conditions at baseline and at 60 and 120 min after LPS injection. Results In the baroreflex closed-loop condition, SNA continued to increase after LPS injection, reaching three-fold the baseline value at 120 min (baseline: 94.7 ± 3.6 vs. 120 min: 283.9 ± 31.9 a.u.). In contrast, AP increased initially (until 75 min), then declined to the baseline level. In the baroreflex open-loop condition, LPS reset the neural arc (CSP-SNA relationship) upward to higher SNA, while shifted the peripheral arc (SNA-AP relationship) downward at 120 min after the injection. As a result, the operating point determined by the intersection between function curves of neural arc and peripheral arc showed marked sympatho-excitation without substantial changes in AP. Conclusions LPS-induced acute inflammation markedly increased SNA via resetting of the baroreflex neural arc, and suppressed the peripheral arc. The balance between the augmented neural arc and suppressed peripheral arc determines SNA and hemodynamics in LPS-induced acute inflammation. PMID:29329321

Impact of lipopolysaccharide-induced acute inflammation on baroreflex-controlled sympathetic arterial pressure regulation.

PubMed

Tohyama, Takeshi; Saku, Keita; Kawada, Toru; Kishi, Takuya; Yoshida, Keimei; Nishikawa, Takuya; Mannoji, Hiroshi; Kamada, Kazuhiro; Sunagawa, Kenji; Tsutsui, Hiroyuki

2018-01-01

Lipopolysaccharide (LPS) induces acute inflammation, activates sympathetic nerve activity (SNA) and alters hemodynamics. Since the arterial baroreflex is a negative feedback system to stabilize arterial pressure (AP), examining the arterial baroreflex function is a prerequisite to understanding complex hemodynamics under LPS challenge. We investigated the impact of LPS-induced acute inflammation on SNA and AP regulation by performing baroreflex open-loop analysis. Ten anesthetized Sprague-Dawley rats were used. Acute inflammation was induced by an intravenous injection of LPS (60 μg/kg). We isolated the carotid sinuses from the systemic circulation and controlled carotid sinus pressure (CSP) by a servo-controlled piston pump. We matched CSP to AP to establish the baroreflex closed-loop condition, whereas we decoupled CSP from AP to establish the baroreflex open-loop condition and changed CSP stepwise to evaluate the baroreflex open-loop function. We recorded splanchnic SNA and hemodynamic parameters under baroreflex open- and closed-loop conditions at baseline and at 60 and 120 min after LPS injection. In the baroreflex closed-loop condition, SNA continued to increase after LPS injection, reaching three-fold the baseline value at 120 min (baseline: 94.7 ± 3.6 vs. 120 min: 283.9 ± 31.9 a.u.). In contrast, AP increased initially (until 75 min), then declined to the baseline level. In the baroreflex open-loop condition, LPS reset the neural arc (CSP-SNA relationship) upward to higher SNA, while shifted the peripheral arc (SNA-AP relationship) downward at 120 min after the injection. As a result, the operating point determined by the intersection between function curves of neural arc and peripheral arc showed marked sympatho-excitation without substantial changes in AP. LPS-induced acute inflammation markedly increased SNA via resetting of the baroreflex neural arc, and suppressed the peripheral arc. The balance between the augmented neural arc and suppressed peripheral arc determines SNA and hemodynamics in LPS-induced acute inflammation.

Rationale and design of the Aquapheresis Versus Intravenous Diuretics and Hospitalization for Heart Failure (AVOID-HF) trial.

PubMed

Costanzo, Maria Rosa; Negoianu, Daniel; Fonarow, Gregg C; Jaski, Brian E; Bart, Bradley A; Heywood, J Thomas; Nabut, Jose L; Schollmeyer, Michael P

2015-09-01

In patients hospitalized with acutely decompensated heart failure, unresolved signs and symptoms of fluid overload have been consistently associated with poor outcomes. Regardless of dosing and type of administration, intravenous loop diuretics have not reduced heart failure events or mortality in patients with acutely decompensated heart failure. The results of trials comparing intravenous loop diuretics to mechanical fluid removal by isolated venovenous ultrafiltration have yielded conflicting results. Studies evaluating early decongestive strategies have shown that ultrafiltration removed more fluid and was associated with fewer heart failure-related rehospitalization than intravenous loop diuretics. In contrast, when used in the setting of worsening renal function, ultrafiltration was associated with poorer renal outcomes and no reduction in heart failure events. The AVOID-HF trial seeks to determine if an early strategy of ultrafiltration in patients with acutely decompensated heart failure is associated with fewer heart failure events at 90 days compared with a strategy based on intravenous loop diuretics. Study subjects from 40 highly experienced institutions are randomized to either early ultrafiltration or intravenous loop diuretics. In both treatment arms, fluid removal therapies are adjusted according to the patients' hemodynamic condition and renal function. The study was unilaterally terminated by the sponsor in the absence of futility and safety concerns after the enrollment of 221 subjects, or 27% of the originally planned sample size of 810 patients. The AVOID-HF trial's principal aim is to compare the safety and efficacy of ultrafiltration vs that of intravenous loop diuretics in patients hospitalized with acutely decompensated heart failure. Because stepped treatment approaches are applied in both ultrafiltration and intravenous loop diuretics groups and the primary end point is time to first heart failure event within 90 days, it is hoped that the AVOID-HF trial, despite its untimely termination by the sponsor, will provide further insight on how to optimally decongest patients with fluid-overloaded heart failure. Copyright © 2015. Published by Elsevier Inc.

Generic isolated horizons in loop quantum gravity

NASA Astrophysics Data System (ADS)

Beetle, Christopher; Engle, Jonathan

2010-12-01

Isolated horizons model equilibrium states of classical black holes. A detailed quantization, starting from a classical phase space restricted to spherically symmetric horizons, exists in the literature and has since been extended to axisymmetry. This paper extends the quantum theory to horizons of arbitrary shape. Surprisingly, the Hilbert space obtained by quantizing the full phase space of all generic horizons with a fixed area is identical to that originally found in spherical symmetry. The entropy of a large horizon remains one-quarter its area, with the Barbero-Immirzi parameter retaining its value from symmetric analyses. These results suggest a reinterpretation of the intrinsic quantum geometry of the horizon surface.

Exposure of Epitope Residues on the Outer Face of the Chikungunya Virus Envelope Trimer Determines Antibody Neutralizing Efficacy

PubMed Central

Fong, Rachel H.; Banik, Soma S. R.; Mattia, Kimberly; Barnes, Trevor; Tucker, David; Liss, Nathan; Lu, Kai; Selvarajah, Suganya; Srinivasan, Surabhi; Mabila, Manu; Miller, Adam; Muench, Marcus O.; Michault, Alain; Rucker, Joseph B.; Paes, Cheryl; Simmons, Graham; Kahle, Kristen M.

2014-01-01

ABSTRACT Chikungunya virus (CHIKV) is a reemerging alphavirus that causes a debilitating arthritic disease and infects millions of people and for which no specific treatment is available. Like many alphaviruses, the structural targets on CHIKV that elicit a protective humoral immune response in humans are poorly defined. Here we used phage display against virus-like particles (VLPs) to isolate seven human monoclonal antibodies (MAbs) against the CHIKV envelope glycoproteins E2 and E1. One MAb, IM-CKV063, was highly neutralizing (50% inhibitory concentration, 7.4 ng/ml), demonstrated high-affinity binding (320 pM), and was capable of therapeutic and prophylactic protection in multiple animal models up to 24 h postexposure. Epitope mapping using a comprehensive shotgun mutagenesis library of 910 mutants with E2/E1 alanine mutations demonstrated that IM-CKV063 binds to an intersubunit conformational epitope on domain A, a functionally important region of E2. MAbs against the highly conserved fusion loop have not previously been reported but were also isolated in our studies. Fusion loop MAbs were broadly cross-reactive against diverse alphaviruses but were nonneutralizing. Fusion loop MAb reactivity was affected by temperature and reactivity conditions, suggesting that the fusion loop is hidden in infectious virions. Visualization of the binding sites of 15 different MAbs on the structure of E2/E1 revealed that all epitopes are located at the membrane-distal region of the E2/E1 spike. Interestingly, epitopes on the exposed topmost and outer surfaces of the E2/E1 trimer structure were neutralizing, whereas epitopes facing the interior of the trimer were not, providing a rationale for vaccine design and therapeutic MAb development using the intact CHIKV E2/E1 trimer. IMPORTANCE CHIKV is the most important alphavirus affecting humans, resulting in a chronic arthritic condition that can persist for months or years. In recent years, millions of people have been infected globally, and the spread of CHIKV to the Americas is now beginning, with over 100,000 cases occurring in the Caribbean within 6 months of its arrival. Our study reports on seven human MAbs against the CHIKV envelope, including a highly protective MAb and rarely isolated fusion loop MAbs. Epitope mapping of these MAbs demonstrates how some E2/E1 epitopes are exposed or hidden from the human immune system and suggests a structural mechanism by which these MAbs protect (or fail to protect) against CHIKV infection. Our results suggest that the membrane-distal end of CHIKV E2/E1 is the primary target for the humoral immune response to CHIKV, and antibodies targeting the exposed topmost and outer surfaces of the E2/E1 trimer determine the neutralizing efficacy of this response. PMID:25275138

Kinematic and Dynamic Studies of Microbursts in the Subcloud Layer Derived from Jaws Dual-Doppler Radar for a Colorado Thunderstorm

DTIC Science & Technology

1988-01-01

Severe Local Strms, Tulsa, Amer. Meteor. Soc., 261-264. Chong, M., F. Rous, and J. Testud , 1980: A New Filtering and * Interpolating Method for Processing...Mesoscale Studies. Tellus, 27, 157-167. Roux, F., J. Testud , M. Payen, and B. Pinty, 1984: Pressure and Temperature Fields Retrieved from Dual-Doppler Radar

The Effect of a Perceptual-Motor Intervention Programme on Learning Readiness of Grade R Learners from South African Deprived Environments

ERIC Educational Resources Information Center

Erasmus, Myrtle; Janse van Rensburg, Ona; Pienaar, Anita E.; Ellis, Suria

2016-01-01

South Africa consists of developed and developing contexts. This article reports on a study undertaken to determine the effect of a Perceptual--motor Intervention Programme in learning readiness of Grade R learners from deprived environments. Le Roux's Group Test for School Readiness was used as baseline assessments to establish the school…

Catastrophic Bleeding From a Marginal Ulcer After Gastric Bypass

PubMed Central

Sidani, Shafik; Akkary, Ehab

2013-01-01

Marginal ulceration at the gastrojejunal anastomosis is a common complication following Roux-Y gastric bypass (RYGB). Hemodynamically significant hemorrhagic marginal ulcers are usually treated either endoscopically or surgically. We describe a unique case of life-threatening hemorrhagic marginal ulcer eroding into the main splenic artery. This condition was initially managed with angiographic embolization, followed by surgical intervention. PMID:23743389

[Routine fluoroscopic investigations after primary bariatric surgery].

PubMed

Gärtner, D; Ernst, A; Fedtke, K; Jenkner, J; Schöttler, A; Reimer, P; Blüher, M; Schön, M R

2016-03-01

Staple line and anastomotic leakages are life-threatening complications after bariatric surgery. Upper gastrointestinal (GI) tract X-ray examination with oral administration of a water-soluble contrast agent can be used to detect leaks. The aim of this study was to evaluate the impact of routine upper GI tract fluoroscopy after primary bariatric surgery. Between January 2009 and December 2014 a total of 658 bariatric interventions were carried out of which 442 were primary bariatric operations. Included in this single center study were 307 sleeve gastrectomies and 135 Roux-en-Y gastric bypasses. Up to December 2012 upper GI tract fluoroscopy was performed routinely between the first and third postoperative days and the detection of leakages was evaluated. In the investigation period 8 leakages (2.6 %) after sleeve gastrectomy, 1 anastomotic leakage in gastrojejunostomy and 1 in jejunojejunostomy after Roux-en-Y gastric bypass occurred. All patients developed clinical symptoms, such as abdominal pain, tachycardia or fever. In one case the leakage was detected by upper GI fluoroscopy and in nine cases radiological findings were unremarkable. No leakages were detected in asymptomatic patients. Routine upper GI fluoroscopy is not recommended for uneventful postoperative courses after primary bariatric surgery.

Endoscopic treatment of Roux-en-Y gastric bypass-related gastrocutaneous fistulas using a novel biomaterial.

PubMed

Maluf-Filho, Fauze; Hondo, Fabio; Halwan, Bhawna; de Lima, Marcelo Simas; Giordano-Nappi, José Humberto; Sakai, Paulo

2009-07-01

Roux-en-Y gastric bypass (RYGB) is amongst the commonest surgical intervention for weight loss in obese patients. Gastrocutaneous fistula, which usually occurs along the vertical staple line of the pouch, is amongst its most alarming complications. Medical management comprised of wound drainage, nutritional support, acid suppression, and antibiotics may be ineffective in as many as a third of patients with this complication. We present outcomes after endoscopic application of SurgiSIS, which is a novel biomaterial for the treatment of this complication. A case series of 25 patients. Twenty-five patients who had failed conservative medical management of gastrocutaneous fistula after RYGB underwent endoscopic application of SurgiSIS--an acellular fibrogenic matrix biomaterial to help fistula healing. Fistula closure as assessed by upper gastrointestinal imaging and endoscopic examination. In patients who had failed medical management lasting 4-25 (median, 7) weeks, closure of the fistulous tract was successful after one application in six patients (30%), two applications in 11 patients (55%), and three applications in three patients (15%). There were no procedure-related complications. Endoscopic application of SurgiSIS-an acellular fibrogenic matrix--is safe and effective for the treatment of gastrocutaneous fistula after RYGB.

Roux-en-Y gastric bypass does not affect daily water intake or the drinking response to dipsogenic stimuli in rats.

PubMed

Marshall, Anikó; Santollo, Jessica; Corteville, Caroline; Lutz, Thomas A; Daniels, Derek

2014-07-15

Bariatric surgery is currently the most effective treatment for severe obesity, and Roux-en-Y gastric bypass (RYGB) is the most common approach in the United States and worldwide. Many studies have documented the changes in body weight, food intake, and glycemic control associated with the procedure. Although dehydration is commonly listed as a postoperative complication, little focus has been directed to testing the response to dipsogenic treatments after RYGB. Accordingly, we used a rat model of RYGB to test for procedure-induced changes in daily water intake and in the response to three dipsogenic treatments: central administration of ANG II, peripheral injection of hypertonic saline, and overnight water deprivation. We did not find any systematic differences in daily water intake of sham-operated and RYGB rats, nor did we find any differences in the response to the dipsogenic treatments. The results of these experiments suggest that RYGB does not impair thirst responses and does not enhance any satiating effect of water intake. Furthermore, these data support the current view that feedback from the stomach is unnecessary for the termination of drinking behavior and are consistent with a role of orosensory or postgastric feedback.

The Treatment of Achalasia in Obese Patients.

PubMed

Wesp, Julie A; Farrell, Timothy M

2018-04-01

Epidemiological studies have demonstrated that obesity is frequently associated with esophageal motility disorders. Morbid obesity and achalasia may coexist in the same patient. The management of the morbidly obese patient with achalasia is complex and the most effective treatment remains controversial. The aim of this study is to review the pathophysiology, clinical presentation, diagnostic evaluation, and treatment of achalasia in morbidly obese patients. PubMed search from January 1990 to July 2017, including the following terms: achalasia, morbid obesity, bariatric, and treatment. Achalasia in the setting of morbid obesity may be successfully treated by endoscopic or surgical methods. Surgeons may choose to add a bariatric procedure, with various strategies present in the literature. A review of the present literature suggests that the preferred approach to achalasia in the morbidly obese patient is to address both disease processes simultaneously with a laparoscopic Heller myotomy and a Roux-en-Y gastric bypass. Roux-en-Y gastric bypass is cited by most experts as the bariatric procedure of choice, given its antireflux benefits. A well-powered study, comparing the various approaches to the treatment of achalasia in the setting of morbid obesity, is required to establish a consensus.

Assessment of routine elimination of postoperative nasogastric decompression after Roux-en-Y gastric bypass.

PubMed

Huerta, Sergio; Arteaga, James R; Sawicki, Mark P; Liu, Carson D; Livingston, Edward H

2002-11-01

Anastomotic disruption after surgical intervention is an infrequent complication, but may lead to severe morbidity and mortality when it occurs. Of the various gastric procedures, the Roux-en-Y gastric bypass (RYGB) has one of the highest risks for anastomotic leakage. Consequently, a nasogastric tube (NGT) is frequently placed when these operations are performed. Most studies examining the outcomes for patients without postoperative NGTs have been relatively small with groups of patients undergoing a variety of operations. Assessing the incidence of anastomotic leaks by routine elimination of postoperative NGTs requires a large number of patients. In this study, we assessed the safety and efficacy of routine elimination of NGTs in a large cohort of patients undergoing a single operation. We reviewed our experience with 1067 patients who underwent RYGB at the UCLA medical center. Fifty-six patients had NGTs routinely placed before the implementation of a standard protocol, which eliminated postoperative NGT decompression. The complication rate for the RYGB patient cohort with and without postoperative NGT was compared. We found no difference in the complication rates between the 2 groups (Fisher exact test; P =.21). Our findings suggest that routine placement of an NGT after RYGB is unnecessary.

Roux-En Y Gastric Bypass Results in Long-Term Remission of Hepatocyte Apoptosis and Hepatic Histological Features of Non-alcoholic Steatohepatitis.

PubMed

Schneck, Anne-Sophie; Anty, Rodolphe; Patouraux, Stéphanie; Bonnafous, Stéphanie; Rousseau, Déborah; Lebeaupin, Cynthia; Bailly-Maitre, Beatrice; Sans, Arnaud; Tran, Albert; Gugenheim, Jean; Iannelli, Antonio; Gual, Philippe

2016-01-01

The long-term effects of bariatric surgery on non-alcoholic steatohepatitis (NASH), focusing on liver injury and hepatocyte apoptosis, are not well-established. We here performed a longitudinal study with paired liver biopsies of nine morbidly obese women (median BMI: 42 [38.7; 45.1] kg/m(2)) with NASH with a median follow-up of 55 [44; 75] months after laparoscopic Roux-en-Y gastric bypass (LRYGB) surgery. LRYGB surgery was associated with significant weight loss (median BMI loss -13.7 [-16.4; -9.5] kg/m(2)), improved hepatic steatosis in all patients (55.5% with total resolution), and resolution of hepatic inflammation and hepatocyte ballooning in 100 and 88.8% of cases, respectively. Alanine aminotransferase levels dropped to normal values while hepatic activated cleaved caspase-3 levels strongly decreased after a median follow-up of 55 months. Hepatocyte apoptosis, as evaluated by serum caspase-generated keratin-18 fragment, improved within the first year following LRYGB and these improvements persisted for at least 55 months. LRYGB in morbidly obese patients with NASH is thus associated with a long-lasting beneficial impact on hepatic steatohepatitis and hepatocyte death.

Dinitroanilines Bind α-Tubulin to Disrupt Microtubules

PubMed Central

Morrissette, Naomi S.; Mitra, Arpita; Sept, David; Sibley, L. David

2004-01-01

Protozoan parasites are remarkably sensitive to dinitroanilines such as oryzalin, which disrupt plant but not animal microtubules. To explore the basis of dinitroaniline action, we isolated 49 independent resistant Toxoplasma gondii lines after chemical mutagenesis. All 23 of the lines that we examined harbored single point mutations in α-tubulin. These point mutations were sufficient to confer resistance when transfected into wild-type parasites. Several mutations were in the M or N loops, which coordinate protofilament interactions in the microtubule, but most of the mutations were in the core of α-tubulin. Docking studies predict that oryzalin binds with an average affinity of 23 nM to a site located beneath the N loop of Toxoplasma α-tubulin. This binding site included residues that were mutated in several resistant lines. Moreover, parallel analysis of Bos taurus α-tubulin indicated that oryzalin did not interact with this site and had a significantly decreased, nonspecific affinity for vertebrate α-tubulin. We propose that the dinitroanilines act through a novel mechanism, by disrupting M-N loop contacts. These compounds also represent the first class of drugs that act on α-tubulin function. PMID:14742718

Degradation pattern of photosystem II reaction center protein D1 in intact leaves. The major photoinhibition-induced cleavage site in D1 polypeptide is located amino terminally of the DE loop.

PubMed

Kettunen, R; Tyystjärvi, E; Aro, E M

1996-08-01

Photoinhibition-induced degradation of the D1 protein of the photosystem II reaction center was studied in intact pumpkin (Cucurbita pepo L.) leaves. Photoinhibition was observed to cause the cleavage of the D1 protein at two distinct sites. The main cleavage generated an 18-kD N-terminal and a 20-kD C-terminal degradation fragment of the D1 protein. this cleavage site was mapped to be located clearly N terminally of the DE loop. The other, less-frequent cleavage occurred at the DE loop and produced the well-documented 23-kD, N-terminal D1 degradation product. Furthermore, the 23-kD, N-terminal D1 fragment appears to be phosphorylated and can be detected only under severe photoinhibition in vivo. Comparison of the D1 degradation pattern after in vivo photoinhibition to that after in vitro acceptor-side and donor-side photoinhibition, performed with isolated photosystem II core particles, gives indirect evidence in support of donor-side photoinhibition in intact leaves.

Dislocation loop formation by swift heavy ion irradiation of metals.

PubMed

Khara, Galvin S; Murphy, Samuel T; Duffy, Dorothy M

2017-07-19

A coupled two-temperature, molecular dynamics methodology is used to simulate the structural evolution of bcc metals (Fe and W) and fcc metals (Cu and Ni) following irradiation by swift heavy ions. Electronic temperature dependent electronic specific heat capacities and electron-phonon coupling strengths are used to capture the full effects of the variation in the electronic density of states. Tungsten is found to be significantly more resistant to damage than iron, due both to the higher melting temperature and the higher thermal conductivity. Very interesting defect structures, quite different from defects formed in cascades, are found to be created by swift heavy ion irradiation in the bcc metals. Isolated vacancies form a halo around elongated interstitial dislocation loops that are oriented along the ion path. Such configurations are formed by rapid recrystallization of the molten cylindrical region that is created by the energetic ion. Vacancies are created at the recrystallization front, resulting in excess atoms at the core which form interstitial dislocation loops on completion of crystallization. These unique defect structures could, potentially, be used to create metal films with superior mechanical properties and interesting nanostructures.

Dislocation loop formation by swift heavy ion irradiation of metals

NASA Astrophysics Data System (ADS)

Khara, Galvin S.; Murphy, Samuel T.; Duffy, Dorothy M.

2017-07-01

A coupled two-temperature, molecular dynamics methodology is used to simulate the structural evolution of bcc metals (Fe and W) and fcc metals (Cu and Ni) following irradiation by swift heavy ions. Electronic temperature dependent electronic specific heat capacities and electron-phonon coupling strengths are used to capture the full effects of the variation in the electronic density of states. Tungsten is found to be significantly more resistant to damage than iron, due both to the higher melting temperature and the higher thermal conductivity. Very interesting defect structures, quite different from defects formed in cascades, are found to be created by swift heavy ion irradiation in the bcc metals. Isolated vacancies form a halo around elongated interstitial dislocation loops that are oriented along the ion path. Such configurations are formed by rapid recrystallization of the molten cylindrical region that is created by the energetic ion. Vacancies are created at the recrystallization front, resulting in excess atoms at the core which form interstitial dislocation loops on completion of crystallization. These unique defect structures could, potentially, be used to create metal films with superior mechanical properties and interesting nanostructures.

Escherichia coli tatC mutations that suppress defective twin-arginine transporter signal peptides.

PubMed

Strauch, Eva-Maria; Georgiou, George

2007-11-23

In vitro studies have suggested that the TatBC complex serves as the receptor for signal peptides targeted for export via the twin-arginine translocation (Tat) pathway. Substitution of the hallmark twin-arginine dipeptide with two lysines abrogates export of physiological substrates in all organisms. We report the isolation and characterization of suppressor mutations that allow export of an ssTor(KK)-GFP-SsrA tripartite fusion. We identified two amino acid suppressor mutations in the first cytoplasmic loop of TatC. In addition, two other amino acids in the first cytoplasmic loop exhibit epistatic suppression. Surprisingly, we also identified a suppressor mutation predicted to lie within the second periplasmic loop of TatC, a region that is not expected to interact directly with the signal peptide. The suppressor mutations allowed export of the native Esherichia coli Tat substrate trimethylamine N-oxide reductase with a twin-lysine substitution in its signal sequence. The cytoplasmic suppressor mutations conferred SDS sensitivity and partial filamentation, indicating that Tat export of authentic substrates was impaired.

Development of a cryogenic capillary pumped loop

NASA Astrophysics Data System (ADS)

Kroliczek, Edward J.; Cullimore, Brent

1996-03-01

This paper describes the initial development of a promising new cryogenic technology. Room temperature capillary pumped loops (CPLs), a derivative of heat pipe technology, have been under development for almost two decades and are emerging as a design solution for many spacecraft thermal control problems. While cryogenic capillary pumped loops have application to passive spacecraft radiators and to long term storage of cryogenic propellants and open-cycle coolants, their application to the integration of spacecraft cryocoolers has generated the most excitement. Without moving parts or complex controls, they are able to thermally connect redundant cryocoolers to a single remote load, eliminating thermal switches and providing mechanical isolation at the same time. Development of a cryogenic CPL (CCPL) presented some unique challenges including start-up from a super-critical state, the management of parasitic heat leaks and pressure containment at ambient temperatures. These challenges have been overcome with a novel design that requires no additional devices or preconditioning for start-up. This paper describes the design concept and development and results conducted under SBIR Phase I and Phase II.

Note: A dual temperature closed loop batch reactor for determining the partitioning of trace gases within CO{sub 2}-water systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Warr, Oliver, E-mail: oliver.warr@earth.ox.ac.uk; Ballentine, Christopher J.; Rochelle, Christopher A.

An experimental approach is presented which can be used to determine partitioning of trace gases within CO{sub 2}-water systems. The key advantages of this system are (1) The system can be isolated with no external exchange, making it ideal for experiments with conservative tracers. (2) Both phases can be sampled concurrently to give an accurate composition at each phase at any given time. (3) Use of a lower temperature flow loop outside of the reactor removes contamination and facilitates sampling. (4) Rapid equilibration at given pressure/temperature conditions is significantly aided by stirring and circulating the water phase using a magneticmore » stirrer and high-pressure liquid chromatography pump, respectively.« less

Mitigation of steam generator tube rupture in a pressurized water reactor with passive safety systems

DOEpatents

McDermott, D.J.; Schrader, K.J.; Schulz, T.L.

1994-05-03

The effects of steam generator tube ruptures in a pressurized water reactor are mitigated by reducing the pressure in the primary loop by diverting reactor coolant through the heat exchanger of a passive heat removal system immersed in the in containment refueling water storage tank in response to a high feed water level in the steam generator. Reactor coolant inventory is maintained by also in response to high steam generator level introducing coolant into the primary loop from core make-up tanks at the pressure in the reactor coolant system pressurizer. The high steam generator level is also used to isolate the start-up feed water system and the chemical and volume control system to prevent flooding into the steam header. 2 figures.

Mitigation of steam generator tube rupture in a pressurized water reactor with passive safety systems

DOEpatents

McDermott, Daniel J.; Schrader, Kenneth J.; Schulz, Terry L.

1994-01-01

The effects of steam generator tube ruptures in a pressurized water reactor are mitigated by reducing the pressure in the primary loop by diverting reactor coolant through the heat exchanger of a passive heat removal system immersed in the in containment refueling water storage tank in response to a high feed water level in the steam generator. Reactor coolant inventory is maintained by also in response to high steam generator level introducing coolant into the primary loop from core make-up tanks at the pressure in the reactor coolant system pressurizer. The high steam generator level is also used to isolate the start-up feed water system and the chemical and volume control system to prevent flooding into the steam header. 2 figures.

[Treatment of postoperative abdominal hernias with polypropylene endoprosthesis].

PubMed

Chakhvadze, B Iu; Nakashidze, D Kh

2009-06-01

The results of the surgical treatment of 82 patients with postoperative abdominal hernias were analysed. All of the patients underwent surgery with polypropylene endoprosthesis. The choice of a hernioplasty method depended on relative volume of postoperative hernia. Middle-sized hernias were indications for reconstructive surgery (complete adaptation of muscular and aponeurotic layers was maintained). The large and gigantic hernias were indications for correcting surgery (specified diastasis of muscular and aponeurotic layers was maintained). In case of lacking of peritoneum (30 patients) greater omentum was used for isolation of the net from intestinal loops. It is concluded that greater omentum provides good extraperitonisation of transplant from intestinal loop and prevents complications due to contact of net with abdominal organs. Postoperative complications mainly were local and seen in 29% cases. There were no lethal outcomes.

[Effect of heterozygosity for insertions of homogeneously stained regions in chromosome 1 of the house mouse on synapsis in meiotic prophase].

PubMed

Borodin, P M; Ladygina, T Iu; Gorlov, I P

1989-02-01

Electron microscope analysis of surface-spread synaptonemal complexes (SC) in oocytes and spermatocytes from double cis heterozygotes for Is(HSR; 1C5)1Icg and Is(HSR; 1E3)2Icg was carried out. Aberrant chromosomes were isolated from the feral population of Mus musculus musculus of Novosibirsk. They contain homogeneously stained regions of total length of about 30% of Chr 1 mitotic metaphase. Heteromorphic bivalents of Chr1 with different lengths of the lateral elements of SC and the loop in the intermedial position were revealed in 4.4% spermatocytes and 20% oocytes of heterozygous animals. The loop size depends on the stage of meiosis: it is maximal at late zygotene and decreases up to disappearance during pachytene.

Detection and differentiation of Fusarium oxysporum f. sp. lycopersici race 1 using loop-mediated isothermal amplification with three primer sets.

PubMed

Ayukawa, Y; Komatsu, K; Kashiwa, T; Akai, K; Yamada, M; Teraoka, T; Arie, T

2016-09-01

Fusarium oxysporum f. sp. lycopersici (Fol) causes tomato wilt. Based on the difference in pathogenicity towards tomato cultivars, Fol is classified into three races. In this study, a rapid method is developed for the detection and discrimination of Fol race 1 using a loop-mediated isothermal amplification (LAMP) assay with two primer sets targeting a region of the nucleotide sequence of the SIX4 gene specific for race 1 and a primer set targeting the SIX5 gene, conserved in all known Fol isolates. Upon LAMP reaction, amplification using all three primer sets was observed only when DNA of Fol race 1 was used as a template, and not when DNA of other Fol races or other fungal species was used. This method could detect 300 fg of Fol race 1 DNA, a 100-fold higher sensitivity than that obtained by conventional PCR. The method can also detect DNA extracted from soil artificially infested with Fol race 1. It is now possible to detect Fol race 1 in colonies and infected tomato stems without DNA isolation. This method is a rapid and simple tool for discrimination of Fol race 1. This study developed a loop-mediated isothermal amplification (LAMP) assay for detection and differentiation of Fusarium oxysporum f. sp. lycopersici (Fol) race 1 by using three primer sets targeting for the SIX4 and SIX5 genes. These genes are present together only in Fol race 1. This method can detect Fol race 1 in infected tomato stems without DNA extraction, affording an efficient diagnosis of Fusarium wilt on tomatoes in the field. © 2016 The Society for Applied Microbiology.

Study of the neovascularisation of prefabrication of flaps using a silicone sheet and an isolated arterial pedicle: experimental study in rabbits.

PubMed

Nguyen, The Hoang; Kloeppel, Marcus; Staudenmaier, Rainer; Werner, Jürgen; Biemer, Edgar

2005-01-01

Use of an isolated artery as an implanted pedicle in prefabricated flaps has rarely been reported either clinically or experimentally. In Chinchilla Bastard rabbits (n = 36), we dissected an isolated arterial pedicle from the femoral and saphenous artery, anastomosed it end-to-end to the femoral vein at the inguinal ligament and created an isolated arterial loop pedicle. This was implanted and fixed with polyglactin 9/0 under a random-pattern vascularised abdominal fasciocutaneous flap. The neovascularisation in the prefabricated flaps was evaluated macroscopically, by blood analysis, selective microangiography, and histology. The results showed a progressive degree of neovascularisation that corresponded to the increasing length of time that the pedicle was implanted in the flaps. Twenty days after prefabrication, the abdominal fasciocutaneous flap was readily perfused by the blood supply from the arterial pedicle. The capacity of the vessels in this group as seen on angiograms had increased to 258 vessels (108%) compared with the control group (239 vessels, 100%).

Actuator with built-in viscous damping for isolation and structural control

NASA Astrophysics Data System (ADS)

Hyde, T. Tupper; Anderson, Eric H.

1994-05-01

This paper describes the development and experimental application of an actuator with built-in viscous damping. An existing passive damper was modified for use as a novel actuation device for isolation and structural control. The device functions by using the same fluid for viscous damping and as a hydraulic lever for a voice coil actuator. Applications for such an actuator include structural control and active isolation. Lumped parameter models capturing structural and fluid effects are presented. Component tests of free stroke, blocked force, and passive complex stiffness are used to update the assumed model parameters. The structural damping effectiveness of the new actuator is shown to be that of a regular D-strut passively and that of a piezoelectric strut with load cell feedback actively in a complex testbed structure. Open and closed loop results are presented for a force isolation application showing an 8 dB passive and 20 dB active improvement over an undamped mount. An optimized design for a future experimental testbed is developed.

Verification of Loop Diagnostics

NASA Technical Reports Server (NTRS)

Winebarger, A.; Lionello, R.; Mok, Y.; Linker, J.; Mikic, Z.

2014-01-01

Many different techniques have been used to characterize the plasma in the solar corona: density-sensitive spectral line ratios are used to infer the density, the evolution of coronal structures in different passbands is used to infer the temperature evolution, and the simultaneous intensities measured in multiple passbands are used to determine the emission measure. All these analysis techniques assume that the intensity of the structures can be isolated through background subtraction. In this paper, we use simulated observations from a 3D hydrodynamic simulation of a coronal active region to verify these diagnostics. The density and temperature from the simulation are used to generate images in several passbands and spectral lines. We identify loop structures in the simulated images and calculate the loop background. We then determine the density, temperature and emission measure distribution as a function of time from the observations and compare with the true temperature and density of the loop. We find that the overall characteristics of the temperature, density, and emission measure are recovered by the analysis methods, but the details of the true temperature and density are not. For instance, the emission measure curves calculated from the simulated observations are much broader than the true emission measure distribution, though the average temperature evolution is similar. These differences are due, in part, to inadequate background subtraction, but also indicate a limitation of the analysis methods.

Predictive Modelling of Operative Performance by Means of Personality Traits - Implications for Selection of Personnel

DTIC Science & Technology

2010-06-02

Inc., Hillsdale. Matsumoto , D., & LeRoux, J. (2003). Measuring the psychological engine of intercultural adjustment: The Intercultural Adjustment...Report 3. DATES COVERED (From – To) 12 September 2007 - 12-Sep-09 4. TITLE AND SUBTITLE Cognitive and Personality Determinants of Cultural ...training since long form corner stones for effective military operations. 15. SUBJECT TERMS EOARD, Psychology , Cognition 16

Evaluation of the learning curve of laparoscopic choledochal cyst excision and Roux-en-Y hepaticojejunostomy in children: CUSUM analysis of a single surgeon's experience.

PubMed

Wen, Zhe; Liang, Huiying; Liang, Jiankun; Liang, Qifeng; Xia, Huimin

2017-02-01

Laparoscopic cyst excision and Roux-en-Y hepaticojejunostomy is gaining popularity as a treatment for choledochal cyst (CDC) in children. However, the learning curve for this challenging laparoscopic procedure has not been addressed. The aim of this study is to determine the characteristics of the learning curve of this procedure. This may guide the training in institutions currently not using this technique. A prospectively collected database comprising all medical records of the first 104 consecutive patients undergoing laparoscopic CDC excision and Roux-en-Y hepaticojejunostomy performed by one surgeon was studied. Multifactorial linear/logistic regression analysis was performed to identify patient-, surgeon-, and procedure-related factors associated with operating times, rates of adverse event, and length of postoperative stay. Cumulative sum analysis demonstrated a learning curve for laparoscopic choledochal cyst excision of 37 cases. Comparing the early with the late experiences (37 vs. 67 cases), the surgeon-specific outcomes significantly improved in terms of operating times (352 vs. 240 min; P < 0.001), postoperative complication rate (13.5 vs. 1.5 %; P = 0.02), and the length of hospital stay (9.4 vs. 7.8 days; P = 0.01). After multivariate analyses, independent predictors of operating times included the completion of the learning curve (CLC) (OR 0.68, 95 % CI 0.63-0.73) and adhesion score (OR middle 1.25, 95 % CI 1.08-1.45; OR high 1.40, 95 % CI 1.20-1.62; compared with the low score); significant predictors of perioperative adverse outcomes were CLC (OR 0.07, 95 % CI 0.02-0.34) and comorbidities prior to the surgery (OR 30.65, 95 % CI 1.71-549.63). The independent predictors of length of postoperative stay included CLC, preoperative comorbidities, and perioperative adverse events. CLC for laparoscopic choledochal cyst excision is 37 cases. After CLC, not only the operative time is reduced, the complications, adverse results, and the length of hospital stay all decreased significantly. The learning curve can be used as the basis for performance guiding the training.

Activation of natriuretic peptides and the sympathetic nervous system following Roux-en-Y gastric bypass is associated with gonadal adipose tissues browning

PubMed Central

Neinast, Michael D.; Frank, Aaron P.; Zechner, Juliet F.; Li, Quanlin; Vishvanath, Lavanya; Palmer, Biff F.; Aguirre, Vincent; Gupta, Rana K.; Clegg, Deborah J.

2015-01-01

Objective Roux-en-Y gastric bypass (RYGB) is an effective method of weight loss and remediation of type-2 diabetes; however, the mechanisms leading to these improvements are unclear. Additionally, adipocytes within white adipose tissue (WAT) depots can manifest characteristics of brown adipocytes. These ‘BRITE/beige’ adipocytes express uncoupling protein 1 (UCP1) and are associated with improvements in glucose homeostasis and protection from obesity. Interestingly, atrial and B-type natriuretic peptides (NPs) promote BRITE/beige adipocyte enrichment of WAT depots, an effect known as “browning.” Here, we investigate the effect of RYGB surgery on NP, NP receptors, and browning in the gonadal adipose tissues of female mice. We propose that such changes may lead to improvements in metabolic homeostasis commonly observed following RYGB. Methods Wild type, female, C57/Bl6 mice were fed a 60% fat diet ad libitum for six months. Mice were divided into three groups: Sham operated (SO), Roux-en-Y gastric bypass (RYGB), and Weight matched, sham operated (WM-SO). Mice were sacrificed six weeks following surgery and evaluated for differences in body weight, glucose homeostasis, adipocyte morphology, and adipose tissue gene expression. Results RYGB and calorie restriction induced similar weight loss and improved glucose metabolism without decreasing food intake. β3-adrenergic receptor expression increased in gonadal adipose tissue, in addition to Nppb (BNP), and NP receptors, Npr1, and Npr2. The ratio of Npr1:Npr3 and Npr2:Npr3 increased in RYGB, but not WM-SO groups. Ucp1 protein and mRNA, as well as additional markers of BRITE/beige adipose tissue and lipolytic genes increased in RYGB mice to a greater extent than calorie-restricted mice. Conclusions Upregulation of Nppb, Npr1, Npr2, and β3-adrenergic receptors in gonadal adipose tissue following RYGB was associated with increased markers of browning. This browning of gonadal adipose tissue may underpin the positive effect of RYGB on metabolic parameters and may in part be mediated through upregulation of natriuretic peptides. PMID:25973390

Structural, metamorphic and geochronological insights on the Variscan evolution of the Alpine basement in the Belledonne Massif (France)

NASA Astrophysics Data System (ADS)

Fréville, Kévin; Trap, Pierre; Faure, Michel; Melleton, Jérémie; Li, Xian-Hua; Lin, Wei; Blein, Olivier; Bruguier, Olivier; Poujol, Marc

2018-02-01

A structural and petrochronological study was carried out in the southern part of the Belledonne crystalline massif. A first tectonometamorphic event, Dx, corresponds to the eastward thrusting of the Chamrousse ophiolitic complex characterized by a low-temperature-moderate-pressure metamorphism reaching 0.535 ± 0.045 GPa and 427.5 ± 17.5 °C. A subsequent D1 deformation is defined by a penetrative S1 foliation that mostly dips toward the west and displays an E-W- to NE-SW-trending mineral and stretching lineation L1. D1 is associated with a top-to-the east shearing and is responsible for the crustal thickening accommodated by the eastward nappe stacking and the emplacement of the Chamrousse ophiolitic complex upon the Rioupéroux-Livet unit. This event is characterized by an amphibolite facies metamorphism (0.58 GPa ± 0.06; 608 ± 14 °C) that attains partial melting at the base of the nappe pile (0.78 ± 0.07 GPa; 680.5 ± 11.5 °C). LA-ICP-MS U-Pb dating of monazite grains from the mica schists of the Rioupéroux-Livet unit constrain the age of D1 to 337 ± 7 Ma. The D2 tectono-metamorphic event is characterized by NE-SW trending, upright to NE-verging synfolial folding. Folding associated with D2 is pervasively developed in all lithotectonic units with the development of a steeply-dipping S2 foliation. In particular, D2 involves the uppermost weakly metamorphosed Taillefer unit. LA-ICP-MS U-Pb dating performed on detrital zircon grains shows that the Taillefer conglomerates was deposited during the Visean. A zircon SIMS U-Pb age of 352 ± 1 Ma from a plagioglase-rich leucocratic sill of the Rioupéroux-Livet unit is interpreted as the age of magmatic emplacement. Our results suggest that the D2 event took place between 330 Ma and 310 Ma. We propose a new interpretation of the tectonometamorphic evolution of the southern part of the Belledonne massif, focusing on the Middle Carboniferous stages of the Variscan orogeny.

Roux-en-Y gastric bypass reverses the effects of diet-induced obesity to inhibit the responsiveness of central vagal motoneurones.

PubMed

Browning, Kirsteen N; Fortna, Samuel R; Hajnal, Andras

2013-05-01

Diet-induced obesity (DIO) has been shown to alter the biophysical properties and pharmacological responsiveness of vagal afferent neurones and fibres, although the effects of DIO on central vagal neurones or vagal efferent functions have never been investigated. The aims of this study were to investigate whether high-fat diet-induced DIO also affects the properties of vagal efferent motoneurones, and to investigate whether these effects were reversed following weight loss induced by Roux-en-Y gastric bypass (RYGB) surgery. Whole-cell patch-clamp recordings were made from rat dorsal motor nucleus of the vagus (DMV) neurones in thin brainstem slices. The DMV neurones from rats exposed to high-fat diet for 12-14 weeks were less excitable, with a decreased membrane input resistance and decreased ability to fire action potentials in response to direct current pulse injection. The DMV neurones were also less responsive to superfusion with the satiety neuropeptides cholecystokinin and glucagon-like peptide 1. Roux-en-Y gastric bypass reversed all of these DIO-induced effects. Diet-induced obesity also affected the morphological properties of DMV neurones, increasing their size and dendritic arborization; RYGB did not reverse these morphological alterations. Remarkably, independent of diet, RYGB also reversed age-related changes of membrane properties and occurrence of charybdotoxin-sensitive (BK) calcium-dependent potassium current. These results demonstrate that DIO also affects the properties of central autonomic neurones by decreasing the membrane excitability and pharmacological responsiveness of central vagal motoneurones and that these changes were reversed following RYGB. In contrast, DIO-induced changes in morphological properties of DMV neurones were not reversed following gastric bypass surgery, suggesting that they may be due to diet, rather than obesity. These findings represent the first direct evidence for the plausible effect of RYGB to improve vagal neuronal health in the brain by reversing some effects of chronic high-fat diet as well as ageing. Vagovagal neurocircuits appear to remain open to modulation and adaptation throughout life, and understanding of these mechanisms may help in development of novel interventions to alleviate environmental (e.g. dietary) ailments and also alter neuronal ageing.

Protocol for a 1-year prospective, longitudinal cohort study of patients undergoing Roux-en-Y gastric bypass and sleeve gastrectomy: the BARI-LIFESTYLE observational study.

PubMed

Jassil, Friedrich C; Carnemolla, Alisia; Kingett, Helen; Paton, Bruce; O'Keeffe, Aidan G; Doyle, Jacqueline; Morris, Stephen; Lewis, Neville; Kirk, Amy; Pucci, Andrea; Chaiyasoot, Kusuma; Batterham, Rachel L

2018-03-16

Roux-en-Y gastric bypass and sleeve gastrectomy are the two most common bariatric surgery performed in the UK that result in comparable weight loss and remission of obesity-associated comorbidities. However, there is a paucity of studies examining the impact of these procedures on body composition, physical activity levels, sedentary behaviour, physical function and strength, dietary intake, health-related quality of life and costs. The BARI-LIFESTYLE observational study is a 1-year prospective, longitudinal cohort study within a real-world routine clinical care setting aiming to recruit 100 patients with severe obesity undergoing either primary Roux-en-Y gastric bypass or sleeve gastrectomy from two bariatric centres in London, UK. Participants will be followed up four times during the study period; presurgery baseline (T0) and at 3 (T1), 6 (T2) and 12 months (T3) postsurgery. In addition to the standard follow-up investigations, assessments including dual-energy X-ray absorptiometry scan, bioelectric impedance analysis, 6 min walk test, sit-to-stand test and handgrip test will be undertaken together with completion of questionnaires. Physical activity levels and sedentary behaviour will be assessed using accelerometer, and dietary intake will be recorded using a 3-day food diary. Outcome measures will include body weight, body fat mass, lean muscle mass, bone mineral density, physical activity levels, sedentary behaviour, physical function and strength, dietary intake, health-related quality of life, remission of comorbidities, healthcare resource utilisation and costs. This study has been reviewed and given a favourable ethical opinion by London-Dulwich Research Ethics Committee (17/LO/0950). The results will be presented to stakeholder groups locally, nationally and internationally and published in peer-reviewed medical journals. The lay-person summary of the findings will be published on the Centre for Obesity Research, University College London website (http://www.ucl.ac.uk/obesity). © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Weight loss, weight regain, and conversions to Roux-en-Y gastric bypass: 10-year results of laparoscopic sleeve gastrectomy.

PubMed

Felsenreich, Daniel M; Langer, Felix B; Kefurt, Ronald; Panhofer, Peter; Schermann, Martin; Beckerhinn, Philipp; Sperker, Christoph; Prager, Gerhard

2016-11-01

With promising short-term results, laparoscopic sleeve gastrectomy (SG) has become the second most frequently performed bariatric procedure worldwide. Aside from a growing number of reports covering up to 10 years of follow-up, only limited data have been published so far on long-term results. The aim of the study was to present a 10-year follow-up for SG. University hospital setting, Austria. We present the first complete 10-year follow-up of 53 consecutive patients who underwent SG before 2006. In this multicenter study, weight loss success, weight regain, and revisional surgery were analyzed beside Bariatric Analysis and Reporting Outcome System (BAROS) scores. A mean maximum percent excess weight loss of 71±25% (percent total weight loss: 28±15%) was reached at a median of 12 (range 12-120) months after SG. At 10 years, a mean percent excess weight loss of 53±25% was achieved by 32 patients, corresponding to a percent total weight loss of 26.3±13.4%. Nineteen of the 53 patients (36%) were converted to Roux-en-Y gastric bypass (n = 18) or duodenal switch (n = 1) due to significant weight regain (n = 11), reflux (n = 6), or acute revision (n = 2) at a median of 36 months. Two patients died at 3 and 101 months postoperatively, unrelated to SG. A total of 31 patients (59%) suffered from weight regain of 10 kg or more, among them 24 patients (45%) with 15 kg or more, 16 patients (30%) with 20 kg or more, and 7 patients (13%) with 25 kg or more weight regain from nadir. Mean BAROS score was 2.4±2.2 at 10 years follow-up, classifying SG as "fairly efficient." Within a long-term follow-up of 10 years or more after SG, a high incidence of both significant weight regain and intractable reflux was observed, leading to conversion, most commonly to Roux-en-Y gastric bypass. Copyright © 2016 American Society for Bariatric Surgery. Published by Elsevier Inc. All rights reserved.

Roux-en-Y gastric bypass reverses the effects of diet-induced obesity to inhibit the responsiveness of central vagal motoneurones

PubMed Central

Browning, Kirsteen N; Fortna, Samuel R; Hajnal, Andras

2013-01-01

Diet-induced obesity (DIO) has been shown to alter the biophysical properties and pharmacological responsiveness of vagal afferent neurones and fibres, although the effects of DIO on central vagal neurones or vagal efferent functions have never been investigated. The aims of this study were to investigate whether high-fat diet-induced DIO also affects the properties of vagal efferent motoneurones, and to investigate whether these effects were reversed following weight loss induced by Roux-en-Y gastric bypass (RYGB) surgery. Whole-cell patch-clamp recordings were made from rat dorsal motor nucleus of the vagus (DMV) neurones in thin brainstem slices. The DMV neurones from rats exposed to high-fat diet for 12–14 weeks were less excitable, with a decreased membrane input resistance and decreased ability to fire action potentials in response to direct current pulse injection. The DMV neurones were also less responsive to superfusion with the satiety neuropeptides cholecystokinin and glucagon-like peptide 1. Roux-en-Y gastric bypass reversed all of these DIO-induced effects. Diet-induced obesity also affected the morphological properties of DMV neurones, increasing their size and dendritic arborization; RYGB did not reverse these morphological alterations. Remarkably, independent of diet, RYGB also reversed age-related changes of membrane properties and occurrence of charybdotoxin-sensitive (BK) calcium-dependent potassium current. These results demonstrate that DIO also affects the properties of central autonomic neurones by decreasing the membrane excitability and pharmacological responsiveness of central vagal motoneurones and that these changes were reversed following RYGB. In contrast, DIO-induced changes in morphological properties of DMV neurones were not reversed following gastric bypass surgery, suggesting that they may be due to diet, rather than obesity. These findings represent the first direct evidence for the plausible effect of RYGB to improve vagal neuronal health in the brain by reversing some effects of chronic high-fat diet as well as ageing. Vagovagal neurocircuits appear to remain open to modulation and adaptation throughout life, and understanding of these mechanisms may help in development of novel interventions to alleviate environmental (e.g. dietary) ailments and also alter neuronal ageing. PMID:23459752

Early effects of ageing on the mechanical performance of isolated locomotory (EDL) and respiratory (diaphragm) skeletal muscle using the work-loop technique.

PubMed

Tallis, Jason; James, Rob S; Little, Alexander G; Cox, Val M; Duncan, Michael J; Seebacher, Frank

2014-09-15

Previous isolated muscle studies examining the effects of ageing on contractility have used isometric protocols, which have been shown to have poor relevance to dynamic muscle performance in vivo. The present study uniquely uses the work-loop technique for a more realistic estimation of in vivo muscle function to examine changes in mammalian skeletal muscle mechanical properties with age. Measurements of maximal isometric stress, activation and relaxation time, maximal power output, and sustained power output during repetitive activation and recovery are compared in locomotory extensor digitorum longus (EDL) and core diaphragm muscle isolated from 3-, 10-, 30-, and 50-wk-old female mice to examine the early onset of ageing. A progressive age-related reduction in maximal isometric stress that was of greater magnitude than the decrease in maximal power output occurred in both muscles. Maximal force and power developed earlier in diaphragm than EDL muscle but demonstrated a greater age-related decline. The present study indicates that ability to sustain skeletal muscle power output through repetitive contraction is age- and muscle-dependent, which may help rationalize previously reported equivocal results from examination of the effect of age on muscular endurance. The age-related decline in EDL muscle performance is prevalent without a significant reduction in muscle mass, and biochemical analysis of key marker enzymes suggests that although there is some evidence of a more oxidative fiber type, this is not the primary contributor to the early age-related reduction in muscle contractility. Copyright © 2014 the American Physiological Society.

YghJ, the secreted metalloprotease of pathogenic E. coli induces hemorrhagic fluid accumulation in mouse ileal loop.

PubMed

Tapader, Rima; Bose, Dipro; Pal, Amit

2017-04-01

YghJ, also known as SslE (Secreted and surface associated lipoprotein) is a cell surface associated and secreted lipoprotein harbouring M60 metalloprotease domain. Though the gene is known to be conserved among both pathogenic and commensal Escherichia coli isolates, the expression and secretion of YghJ was found to be higher among diverse E. coli pathotypes. YghJ, secreted from intestinal pathogens such as enterotoxigenic E. coli (ETEC) and enteropathogenic E. coli (EPEC) has been demonstrated to possess mucinase activity and hence facilitates colonization of these enteric pathogens to intestinal epithelial cells. Importantly, YghJ is also reported to be secreted from extraintestinal pathogenic E. coli isolates. In our previous study we have shown that YghJ, purified from a neonatal septicemic E. coli isolate could trigger induction of various proinflammatory cytokines in vitro. This led us to investigate the role of YghJ in causing in vivo tissue hemorrhage. In the present study, we validate the earlier in vitro finding and have showed that YghJ can cause extensive tissue damage in mouse ileum and is also able to induce significant fluid accumulation in a dose dependent manner in a mouse ileal loop (MIL) assay. Hence, our present study not only confirms the pathogenic potential of YghJ in sepsis pathophysiology but also indicates the enterotoxic ability of YghJ which makes it an important virulence determinant of intestinal pathogenic E. coli. Copyright © 2017 Elsevier Ltd. All rights reserved.

Hydropericardium Hepatitis Syndrome Emerged in Cherry Valley Ducks in China.

PubMed

Chen, H; Dou, Y; Zheng, X; Tang, Y; Zhang, M; Zhang, Y; Wang, Z; Diao, Y

2017-08-01

Since June 2015, a highly pathogenic disease occurred in duck flocks in China, causing pericardial effusion, enlarged discoloured liver, renal enlargement and haemorrhagic lung with a mortality ranging from 5% to 20%. Previous study confirmed that Fowl adenovirus group C (FAdV-C) and some field FAdVs isolates had been identified as causative agents of hydropericardium hepatitis syndrome (HHS) in chickens and geese world widely. In this study, we firstly report the isolation of FAdV-C from ducks with HHS. The two isolates, designated as SDSX and SDJX, were separated from liver samples using 9-day-old SPF chicken embryos and could cause severe cytopathic effects in duck and chicken embryonic kidney cells. The entire ORF sequences of hexon gene of the two isolates were amplified, sequenced and analysed by restriction fragment length polymorphism. Phylogenetic analysis of loop 1 sequences of hexon gene of FAdVs revealed that the two isolates were closely related to FAdV-C isolates, which could cause HHS in chickens. Experimental infection indicated that the isolate was high pathogenicity to 20-day-old ducks. Our study shows that the recently emerged HHS in ducks was caused by FAdV-C and may possess a potential risk to other poultry flocks. © 2016 Blackwell Verlag GmbH.

A lab-on-a-chip system with integrated sample preparation and loop-mediated isothermal amplification for rapid and quantitative detection of Salmonella spp. in food samples.

PubMed

Sun, Yi; Quyen, Than Linh; Hung, Tran Quang; Chin, Wai Hoe; Wolff, Anders; Bang, Dang Duong

2015-04-21

Foodborne disease is a major public health threat worldwide. Salmonellosis, an infectious disease caused by Salmonella spp., is one of the most common foodborne diseases. Isolation and identification of Salmonella by conventional bacterial culture or molecular-based methods are time consuming and usually take a few hours to days to complete. In response to the demand for rapid on line or on site detection of pathogens, in this study, we describe for the first time an eight-chamber lab-on-a-chip (LOC) system with integrated magnetic bead-based sample preparation and loop-mediated isothermal amplification (LAMP) for rapid and quantitative detection of Salmonella spp. in food samples. The whole diagnostic procedures including DNA isolation, isothermal amplification, and real-time detection were accomplished in a single chamber. Up to eight samples could be handled simultaneously and the system was capable to detect Salmonella at concentration of 50 cells per test within 40 min. The simple design, together with high level of integration, isothermal amplification, and quantitative analysis of multiple samples in short time, will greatly enhance the practical applicability of the LOC system for rapid on-site screening of Salmonella for applications in food safety control, environmental surveillance, and clinical diagnostics.

Development of a reverse transcription loop-mediated isothermal amplification method for the rapid detection of avian influenza virus subtype H7.

PubMed

Bao, Hongmei; Wang, Xiurong; Zhao, Yuhui; Sun, Xiaodong; Li, Yanbing; Xiong, Yongzhong; Chen, Hualan

2012-01-01

A rapid and sensitive reverse transcription loop-mediated isothermal amplification (RT-LAMP) method for the detection of the H7 avian influenza virus (H7 AIV) isotype was developed. The minimum detection limit of the RT-LAMP assay was 0.1-0.01 PFU per reaction for H7 AIV RNA, making this assay 100-fold more sensitive than the conventional RT-PCR method. This RT-LAMP assay also has the capacity to detect both high- and low-pathogenic H7 AIV strains. Using a pool of RNAs extracted from influenza viruses corresponding to all 15 HA subtypes (in addition to other avian pathogenic viruses), the RT-LAMP system was confirmed to amplify only H7 AIV RNA. Furthermore, specific pathogen free (SPF) chickens were infected artificially with H7 AIV, throat and cloacal swabs were collected, and viral shedding was examined using viral isolation, RT-PCR and RT-LAMP. Shedding was detected following viral isolation and RT-LAMP one day after infection, whereas viral detection using RT-PCR was effective only on day 3 post-infection. These results indicate that the RT-LAMP method could facilitate epidemiological surveillance and the rapid diagnosis of the avian influenza subtype H7. Copyright © 2011 Elsevier B.V. All rights reserved.

A Sensor Failure Simulator for Control System Reliability Studies

NASA Technical Reports Server (NTRS)

Melcher, K. J.; Delaat, J. C.; Merrill, W. C.; Oberle, L. G.; Sadler, G. G.; Schaefer, J. H.

1986-01-01

A real-time Sensor Failure Simulator (SFS) was designed and assembled for the Advanced Detection, Isolation, and Accommodation (ADIA) program. Various designs were considered. The design chosen features an IBM-PC/XT. The PC is used to drive analog circuitry for simulating sensor failures in real-time. A user defined scenario describes the failure simulation for each of the five incoming sensor signals. Capabilities exist for editing, saving, and retrieving the failure scenarios. The SFS has been tested closed-loop with the Controls Interface and Monitoring (CIM) unit, the ADIA control, and a real-time F100 hybrid simulation. From a productivity viewpoint, the menu driven user interface has proven to be efficient and easy to use. From a real-time viewpoint, the software controlling the simulation loop executes at greater than 100 cycles/sec.

Modeling and stability of segmented reflector telescopes - A decentralized approach

NASA Technical Reports Server (NTRS)

Ryaciotaki-Boussalis, Helen A.; Ih, Che-Hang Charles

1990-01-01

The decentralization of a segmented reflector telescope based on a finite-element model of its structure is considered. The decentralization of the system at the panel level is considered. Each panel is originally treated as an isolated subsystem so that the controller design is performed independently at the local level, and then applied to the composite system for stability analysis. The panel-level control laws were designed by means of pole placement using local output feedback. Simulation results show a better 1000:1 vibration attenuation in panel position when compared to the open-loop system. It is shown that the overall closed-loop system is exponentially stable provided that certain conditions are met. The advantage to the decentralized approach is that the design is performed in terms of the low-dimensionality subsystems, thus drastically reducing the design computational complexities.

High temperature skin friction measurement

NASA Technical Reports Server (NTRS)

Tcheng, Ping; Holmes, Harlan K.; Supplee, Frank H., Jr.

1989-01-01

Skin friction measurement in the NASA Langley hypersonic propulsion facility is described. The sensor configuration utilized an existing balance, modified to provide thermal isolation and an increased standoff distance. For test run times of about 20 sec and ambient-air cooling of the test section and balance, the modified balance performed satisfactorily, even when it was subjected to acoustic and structural vibration. The balance is an inertially balanced closed-loop servo system where the current to a moving-coil motor needed to restore or null the output from the position sensor is a measure of the force or skin friction tending to displace the moving element. The accuracy of the sensor is directly affected by the position sensor in the feedback loop, in this case a linear-variable differential transformer which has proven to be influenced by temperature gradients.

The shuttle orbiter cabin atmospheric revitalization systems

NASA Technical Reports Server (NTRS)

Ward, C. F.; Owens, W. L.

1975-01-01

The Orbiter Atmospheric Revitalization Subsystem (ARS) and Pressure Control Subsystem (ARPCS) are designed to provide the flight crew and passengers with a pressurized environment that is both life-supporting and within crew comfort limitations. The ARPCS is a two-gas (oxygen-nitrogen) system that obtains oxygen from the Power Reactant Supply and Distribution (PRSD) subsystem and nitrogen from the nitrogen storage tanks. The ARS includes the water coolant loop; cabin CO2, odor, humidity and temperature control; and avionics cooling. Baseline ARPCS and ARS changes since 1973 include removal of the sublimator from the water coolant loop, an increase in flowrates to accommodate increased loads, elimination of the avionics bay isolation from the cabin, a decision to have an inert vehicle during ferry flight, elimination of coldwall tubing around windows and hatches, and deletion of the cabin heater.

A sensor failure simulator for control system reliability studies

NASA Astrophysics Data System (ADS)

Melcher, K. J.; Delaat, J. C.; Merrill, W. C.; Oberle, L. G.; Sadler, G. G.; Schaefer, J. H.

A real-time Sensor Failure Simulator (SFS) was designed and assembled for the Advanced Detection, Isolation, and Accommodation (ADIA) program. Various designs were considered. The design chosen features an IBM-PC/XT. The PC is used to drive analog circuitry for simulating sensor failures in real-time. A user defined scenario describes the failure simulation for each of the five incoming sensor signals. Capabilities exist for editing, saving, and retrieving the failure scenarios. The SFS has been tested closed-loop with the Controls Interface and Monitoring (CIM) unit, the ADIA control, and a real-time F100 hybrid simulation. From a productivity viewpoint, the menu driven user interface has proven to be efficient and easy to use. From a real-time viewpoint, the software controlling the simulation loop executes at greater than 100 cycles/sec.

Isolation of bacterial metabolites as natural inducers for larval settlement in the marine polychaete Hydroides elegans (Haswell).

PubMed

Harder, Tilmann; Lau, Stanley Chun Kwan; Dahms, Hans-Uwe; Qian, Pei-Yuan

2002-10-01

The bacterial component of marine biofilms plays an important role in the induction of larval settlement in the polychaete Hydroides elegans. In this study, we provide experimental evidence that bacterial metabolites comprise the chemical signal for larval settlement. Bacteria were isolated from biofilms, purified and cultured according to standard procedures. Bacterial metabolites were isolated from spent culture broth by chloroform extraction as well as by closed-loop stripping and adsorption of volatile components on surface-modified silica gel. A pronounced biological activity was exclusively observed when concentrated metabolites were adsorbed on activated charcoal. Larvae did not respond to waterbome metabolites when prevented from contacting the bacterial film surface. These results indicate that an association of the chemical signal with a sorbent-like substratum may be an essential cofactor for the expression of biological activity. The functional role of bacterial exopolymers as an adsorptive matrix for larval settlement signals is discussed.

Design and control of six degree-of-freedom active vibration isolation table.

PubMed

Hong, Jinpyo; Park, Kyihwan

2010-03-01

A six-axis active vibration isolation system (AVIS) is designed by using the direct driven guide and ball contact mechanisms in order to have no cross-coupling between actuators. The point contact configuration gives an advantage of having an easy assembly of eight voice coil actuators to an upper and a base plate. A voice coil actuator is used since it can provide a large displacement and sufficient bandwidth required for vibration control. The AVIS is controlled considering the effect of flexible vibration mode in the upper plate and velocity sensor dynamics. A loop shaping technique and phase margin condition are applied to design a vibration controller. The performances of the AVIS are investigated in the frequency domain and finally validated by comparing with the passive isolation system. The scanning profiles of the specimen are compared together by using the atomic force microscope. The robustness of the AVIS is verified by showing the impulse response.

Design and control of six degree-of-freedom active vibration isolation table

NASA Astrophysics Data System (ADS)

Hong, Jinpyo; Park, Kyihwan

2010-03-01

A six-axis active vibration isolation system (AVIS) is designed by using the direct driven guide and ball contact mechanisms in order to have no cross-coupling between actuators. The point contact configuration gives an advantage of having an easy assembly of eight voice coil actuators to an upper and a base plate. A voice coil actuator is used since it can provide a large displacement and sufficient bandwidth required for vibration control. The AVIS is controlled considering the effect of flexible vibration mode in the upper plate and velocity sensor dynamics. A loop shaping technique and phase margin condition are applied to design a vibration controller. The performances of the AVIS are investigated in the frequency domain and finally validated by comparing with the passive isolation system. The scanning profiles of the specimen are compared together by using the atomic force microscope. The robustness of the AVIS is verified by showing the impulse response.

Central pancreatectomy for benign pancreatic pathology/trauma: is it a reasonable pancreas-preserving conservative surgical strategy alternative to standard major pancreatic resection?

PubMed

Johnson, Maria A; Rajendran, Shanmugasundaram; Balachandar, Tirupporur G; Kannan, Devy G; Jeswanth, Satyanesan; Ravichandran, Palaniappan; Surendran, Rajagopal

2006-11-01

The aim of this study was to assess the technical feasibility, safety and outcome of central pancreatectomy (CP) with pancreaticogastrostomy or pancreaticojejunostomy in appropriately selected patients with benign central pancreatic pathology/trauma. Benign lesions/trauma of the pancreatic neck and proximal body pose an interesting surgical challenge. CP is an operation that allows resection of benign tumours located in the pancreatic isthmus that are not suitable for enucleation. Between January 2000 and December 2005, eight central pancreatectomies were carried out. There were six women and two men with a mean age of 35.7 years. The cephalic pancreatic stump is oversewn and the distal stump is anastomosed end-to-end with a Roux-en-Y jejunal loop in two and with the stomach in six patients. The indications for CP were: non-functional islet cell tumours in two patients, traumatic pancreatic neck transection in two and one each for insulinoma, solid pseudopapillary tumour, splenic artery pseudoaneurysm and pseudocyst. Pancreatic exocrine function was evaluated by a questionnaire method. Endocrine function was evaluated by blood glucose level. Morbidity rate was 37.5% with no operative mortality. Mean postoperative hospital stay was 10.5 days. Neither of the patients developed pancreatic fistula nor required reoperations or interventional radiological procedures. At a mean follow up of 26.4 months, no patient had evidence of endocrine or exocrine pancreatic insufficiency, all the patients were alive and well without clinical and imaging evidence of disease recurrence. When technically feasible, CP is a safe, pancreas-preserving pancreatectomy for non-enucleable benign pancreatic pathology/trauma confined to pancreatic isthmus that allows for cure of the disease without loss of substantial amount of normal pancreatic parenchyma with preservation of exocrine/endocrine function and without interruption of enteric continuity.

Xenin Augments Duodenal Anion Secretion via Activation of Afferent Neural Pathways

PubMed Central

Kaji, Izumi; Akiba, Yasutada; Kato, Ikuo; Maruta, Koji; Kuwahara, Atsukazu

2017-01-01

Xenin-25, a neurotensin (NT)-related anorexigenic gut hormone generated mostly in the duodenal mucosa, is believed to increase the rate of duodenal ion secretion, because xenin-induced diarrhea is not present after Roux-en-Y gastric bypass surgery. Because the local effects of xenin on duodenal ion secretion have remained uninvestigated, we thus examined the neural pathways underlying xenin-induced duodenal anion secretion. Intravenous infusion of xenin-8, a bioactive C-terminal fragment of xenin-25, dose dependently increased the rate of duodenal HCO3− secretion in perfused duodenal loops of anesthetized rats. Xenin was immunolocalized to a subset of enteroendocrine cells in the rat duodenum. The mRNA of the xenin/NT receptor 1 (NTS1) was predominantly expressed in the enteric plexus, nodose and dorsal root ganglia, and in the lamina propria rather than in the epithelium. The serosal application of xenin-8 or xenin-25 rapidly and transiently increased short-circuit current in Ussing-chambered mucosa-submucosa preparations in a concentration-dependent manner in the duodenum and jejunum, but less so in the ileum and colon. The selective antagonist for NTS1, substance P (SP) receptor (NK1), or 5-hydroxytryptamine (5-HT)3, but not NTS2, inhibited the responses to xenin. Xenin-evoked Cl- secretion was reduced by tetrodotoxin (TTX) or capsaicin-pretreatment, and abolished by the inhibitor of TTX-resistant sodium channel Nav1.8 in combination with TTX, suggesting that peripheral xenin augments duodenal HCO3− and Cl− secretion through NTS1 activation on intrinsic and extrinsic afferent nerves, followed by release of SP and 5-HT. Afferent nerve activation by postprandial, peripherally released xenin may account for its secretory effects in the duodenum. PMID:28115552

Anemia Outcome After Laparascopic Mini Bypass : Analysis of 107 Consecutive Patients.

PubMed

Mokhber, S; Nikoyan, P; Kabir, A; Jesmi, F; Pishgahroudsari, M; Abdolhosseini, M; Alibeigi, P; Rezvani, M; Pazouki, A

2016-01-01

The prevalence of obesity has dramatically increased globally. Weight loss procedures are known to be an effective and reliable method with relatively low complication rate and satisfactory results. Laparoscopic mini-gastric bypass (LMGB) is known as a modified Mason loop procedure with compatible results to laparoscopic Roux-en-Y gastric bypass (LRYGB), and is believed to have even less complication rate. Despite adequate and meticulous supplement therapy, anemia is one of the challenges in patients undergoing LMGB. Thus, we aimed to review the prevalence and severity of anemia in patients undergoing LMGB. A prospectively-maintained database of patients referring to Hazrat Rasoul Akram hospital who underwent LMGB from December 2013 to October 2014 was reviewed retrospectively. A total of 113 consecutive patients were included in the study. The mean age was 38.7 ± 9.8 years. Mean Body mass index (BMI) was 45.5 ± 6.1 kg/m2 preoperatively and 36.7 ± 5.5 kg/m2 and 33.0 ± 5.3 kg/m2 three and six months after the procedure, respectively. (P = 0.001) Mean excess body weight loss after the procedure was 20% and 53% at three and six months post operatively. Serum hemoglobin (Hb) level decreased significantly in three months (P = 0.036) and remained unchanged in six months compared to 3-month (P = 0.385). Vitamin B12 level increased significantly in three months (P = 0.010) and then decrease in six months to the preoperative level (P = 0.889). LMGB is a safe, feasible and an effective alternative weight loss procedure. Simply, anemia can be prevented by utilizing therapeutic dose of multivitamin in patients who underwent this procedure. © Acta Gastro-Enterologica Belgica.

It's positive to be negative: Achilles tendon work loops during human locomotion.

PubMed

Zelik, Karl E; Franz, Jason R

2017-01-01

Ultrasound imaging is increasingly used with motion and force data to quantify tendon dynamics during human movement. Frequently, tendon dynamics are estimated indirectly from muscle fascicle kinematics (by subtracting muscle from muscle-tendon unit length), but there is mounting evidence that this Indirect approach yields implausible tendon work loops. Since tendons are passive viscoelastic structures, when they undergo a loading-unloading cycle they must exhibit a negative work loop (i.e., perform net negative work). However, prior studies using this Indirect approach report large positive work loops, often estimating that tendons return 2-5 J of elastic energy for every 1 J of energy stored. More direct ultrasound estimates of tendon kinematics have emerged that quantify tendon elongations by tracking either the muscle-tendon junction or localized tendon tissue. However, it is unclear if these yield more plausible estimates of tendon dynamics. Our objective was to compute tendon work loops and hysteresis losses using these two Direct tendon kinematics estimates during human walking. We found that Direct estimates generally resulted in negative work loops, with average tendon hysteresis losses of 2-11% at 1.25 m/s and 33-49% at 0.75 m/s (N = 8), alluding to 0.51-0.98 J of tendon energy returned for every 1 J stored. We interpret this finding to suggest that Direct approaches provide more plausible estimates than the Indirect approach, and may be preferable for understanding tendon energy storage and return. However, the Direct approaches did exhibit speed-dependent trends that are not consistent with isolated, in vitro tendon hysteresis losses of about 5-10%. These trends suggest that Direct estimates also contain some level of error, albeit much smaller than Indirect estimates. Overall, this study serves to highlight the complexity and difficulty of estimating tendon dynamics non-invasively, and the care that must be taken to interpret biological function from current ultrasound-based estimates.

Novel poly-uridine insertion in the 3'UTR and E2 amino acid substitutions in a low virulent classical swine fever virus.

PubMed

Coronado, Liani; Liniger, Matthias; Muñoz-González, Sara; Postel, Alexander; Pérez, Lester Josue; Pérez-Simó, Marta; Perera, Carmen Laura; Frías-Lepoureau, Maria Teresa; Rosell, Rosa; Grundhoff, Adam; Indenbirken, Daniela; Alawi, Malik; Fischer, Nicole; Becher, Paul; Ruggli, Nicolas; Ganges, Llilianne

2017-03-01

In this study, we compared the virulence in weaner pigs of the Pinar del Rio isolate and the virulent Margarita strain. The latter caused the Cuban classical swine fever (CSF) outbreak of 1993. Our results showed that the Pinar del Rio virus isolated during an endemic phase is clearly of low virulence. We analysed the complete nucleotide sequence of the Pinar del Rio virus isolated after persistence in newborn piglets, as well as the genome sequence of the inoculum. The consensus genome sequence of the Pinar del Rio virus remained completely unchanged after 28days of persistent infection in swine. More importantly, a unique poly-uridine tract was discovered in the 3'UTR of the Pinar del Rio virus, which was not found in the Margarita virus or any other known CSFV sequences. Based on RNA secondary structure prediction, the poly-uridine tract results in a long single-stranded intervening sequence (SS) between the stem-loops I and II of the 3'UTR, without major changes in the stem- loop structures when compared to the Margarita virus. The possible implications of this novel insertion on persistence and attenuation remain to be investigated. In addition, comparison of the amino acid sequence of the viral proteins E rns , E1, E2 and p7 of the Margarita and Pinar del Rio viruses showed that all non-conservative amino acid substitutions acquired by the Pinar del Rio isolate clustered in E2, with two of them being located within the B/C domain. Immunisation and cross-neutralisation experiments in pigs and rabbits suggest differences between these two viruses, which may be attributable to the amino acid differences observed in E2. Altogether, these data provide fresh insights into viral molecular features which might be associated with the attenuation and adaptation of CSFV for persistence in the field. Copyright © 2017 Elsevier B.V. All rights reserved.

Bariatric Outcomes and Obesity Modeling: Study Meeting

DTIC Science & Technology

2010-09-17

to obesity. 15. SUBJECT TERMS Bariatric Surgery , Cost Effectiveness, Surgical Outcome 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF a. REPORT...EFFECTIVENESS MODEL OVERVIEW  Two parts: 1) Decision Tree and 2) Natural History Model  Results: Bariatric Surgery is cost-effective compared to no...9,300 for AGB $10,600 for LRYGB AGB: Adjustable gastric banding LRYGB: laparoscopic Roux-en-Y gastric bypass A Financial Model of Bariatric Surgery for

Effects of Sleeve Gastrectomy vs. Roux-en-Y Gastric Bypass on Eating Behavior and Sweet Taste Perception in Subjects with Obesity.

PubMed

Nance, Katie; Eagon, J Christopher; Klein, Samuel; Pepino, Marta Yanina

2017-12-24

The goal of this study was to test the hypothesis that weight loss induced by Roux-en-Y gastric bypass (RYGB) has greater effects on taste perception and eating behavior than comparable weight loss induced by sleeve gastrectomy (SG). We evaluated the following outcomes in 31 subjects both before and after ~20% weight loss induced by RYGB ( n = 23) or SG ( n = 8): (1) sweet, savory, and salty taste sensitivity; (2) the most preferred concentrations of sucrose and monosodium glutamate; (3) sweetness palatability, by using validated sensory testing techniques; and (4) eating behavior, by using the Food Craving Inventory and the Dutch Eating Behavior Questionnaire. We found that neither RYGB nor SG affected sweetness or saltiness sensitivity. However, weight loss induced by either RYGB or SG caused the same decrease in: (1) frequency of cravings for foods; (2) influence of emotions and external food cues on eating behavior; and (3) shifted sweetness palatability from pleasant to unpleasant when repetitively tasting sucrose (all p -values ≤ 0.01). Therefore, when matched on weight loss, SG and RYGB cause the same beneficial effects on key factors involved in the regulation of eating behavior and hedonic component of taste perception.

Very low-calorie diet mimics the early beneficial effect of Roux-en-Y gastric bypass on insulin sensitivity and β-cell Function in type 2 diabetic patients.

PubMed

Jackness, Clifton; Karmally, Wahida; Febres, Gerardo; Conwell, Irene M; Ahmed, Leaque; Bessler, Marc; McMahon, Donald J; Korner, Judith

2013-09-01

Marked improvement in glycemic control occurs in patients with type 2 diabetes mellitus shortly after Roux-en-Y gastric bypass surgery (RYGB) and before there is major weight loss. The objective of this study was to determine whether the magnitude of this change is primarily due to caloric restriction or is unique to the surgical procedure. We studied eleven subjects who underwent RYGB and fourteen subjects mean-matched for BMI, HbA1c, and diabetes duration who were admitted to our inpatient research unit and given a very low-calorie diet (VLCD) of 500 kcal/day with a macronutrient content similar to that consumed by patients after RYGB. Frequently sampled intravenous glucose tolerance tests were performed before and after interventions. Both groups lost an equivalent amount of weight over a mean study period of 21 days. Insulin sensitivity, acute insulin secretion after intravenous glucose administration, and β-cell function as determined by disposition index improved to a similar extent in both groups. Likewise, changes in fasting glucose and fructosamine levels were similar. Based on these data, VLCD improves insulin sensitivity and β-cell function just as well as RYGB in the short term.

Water-soluble upper GI based on clinical findings is reliable to detect anastomotic leaks after laparoscopic gastric bypass.

PubMed

Katasani, V G; Leeth, R R; Tishler, D S; Leath, T D; Roy, B P; Canon, C L; Vickers, S M; Clements, R H

2005-11-01

Anastomotic leak after laparoscopic Roux-en-Y gastric bypass (LGB) is a major complication that must be recognized and treated early for best results. There is controversy in the literature regarding the reliability of upper GI series (UGI) in diagnosing leaks. LGB was performed in patients meeting NIH criteria for the surgical treatment of morbid obesity. All leaks identified at the time of surgery were repaired with suture and retested. Drains were placed at the surgeon's discretion. Postoperatively, UGI was performed by an experienced radiologist if there was a clinical suspicion of leak. From September 2001 until October 2004, a total of 553 patients (age 40.4 +/- 9.2 years, BMI 48.6 +/- 7.2) underwent LGB at UAB. Seventy-eight per cent (431 of 553) of patients had no clinical evidence suggesting anastomotic leak and were managed expectantly. Twenty-two per cent (122 of 553) of patients met at least one inclusion criteria for leak and underwent UGI. Four of 122 patients (3.2%) had a leak, two from anastomosis and two from the perforation of the stapled end of the Roux limb. No patient returned to the operating room without a positive UGI. High clinical suspicion and selectively performed UGI based on clinical evidence is reliable in detecting leaks.

Roux-en-Y gastric bypass in the treatment of non-classic congenital adrenal hyperplasia due to 11-hydroxylase deficiency.

PubMed

Kalani, Amir; Thomas, Nithin; Sacerdote, Alan; Bahtiyar, Gül

2013-03-18

Non-classic adrenal hyperplasia (NCAH) has been associated with insulin resistance (IR). Therapies such as metformin, thiazolidinediones and lifestyle alterations improve IR and also ameliorate the biochemical and clinical abnormalities of NCAH, much as they do in polycystic ovarian syndrome (PCOS). More recently, bariatric surgery, such as Roux-en-Y gastric bypass (RYGBP), has also been associated with improvement in IR and amelioration of PCOS and may, therefore, be beneficial in NCAH. We report a case of a 39-year-old, deaf-mute, obese woman with NCAH due to 11-hydroxylase deficiency who underwent RYGBP followed by improvement of NCAH manifestations. She was initially treated with metformin and pioglitazone, which lowered serum 11-deoxycortisol from 198 ng/dl (<51) to 26 ng/dl. Five weeks after undergoing RYGBP her body mass index fell from 44.18 kg/m(2) to 39.54 kg/m(2) and, despite not taking metformin or pioglitazone, serum 11-deoxycortisol remained normal at <40 ng/dl. Concurrently and subsequently, her NCAH symptoms, for example, alopecia, hirsutism and irregular menses normalised as well. We conclude that RYGBP, like other interventions that reduce IR, may be another way of treating non-classic 11-hydroxylase deficiency in selected patients.

De-novo cholangiocarcinoma in native common bile duct remnant following OLT for primary sclerosing cholangitis.

PubMed

Landaverde, Carmen; Ng, Vivian; Sato, Alisa; Tabibian, James; Durazo, Francisco; Busuttil, Ronald

2009-01-01

Primary sclerosing cholangitis (PSC) is a chronic, progressive, inflammatory and obstructive disease of the intra- and extra-hepatic bile ducts of unknown etiology. Currently, orthotopic liver transplantation (OLT) is the only definitive treatment for PSC-related end-stage liver disease. However, PSC has been known to recur in the grafted liver. Roux-en-Y hepaticojejunostomy is more commonly performed than choledochocholedochostomy for PSC, although choledochocholedochostomy has been found to be safe and efficacious for PSC if the distal common bile duct is uninvolved at the time of OLT. Our case is unique in that it describes a patient who developed de-novo cholangiocarcinoma in the remnant portion of the native common bile duct six years after OLT with choledochocholedochostomy for PSC-associated end-stage liver disease without having PSC recurrence. In conclusion, our case report indicates that choledochocholedochostomy may not be desirable in PSC due to an increased risk of developing cholangiocarcinoma in the native common bile duct. This risk exists as well with a Roux-en-Y hepaticojejunostomy in the remaining intra-duodenal and intra-pancreatic biliary epithelium, although in theory to a lesser extent. Therefore, the risk of developing cholangiocarcinoma in the recipient common bile duct can only be completely eliminated by performing a Whipple procedure at the time of OLT.

Effects of Roux-en-Y gastric bypass on energy and glucose homeostasis are preserved in two mouse models of functional glucagon-like peptide-1 deficiency☆ab

PubMed Central

Mokadem, Mohamad; Zechner, Juliet F.; Margolskee, Robert F.; Drucker, Daniel J.; Aguirre, Vincent

2013-01-01

Glucagon-like peptide-1 (GLP-1) secretion is greatly enhanced after Roux-en-Y gastric bypass (RYGB). While intact GLP-1exerts its metabolic effects via the classical GLP-1 receptor (GLP-1R), proteolytic processing of circulating GLP-1 yields metabolites such as GLP-1(9–36)amide/GLP-1(28–36)amide, that exert similar effects independent of the classical GLP-1R. We investigated the hypothesis that GLP-1, acting via these metabolites or through its known receptor, is required for the beneficial effects of RYGB using two models of functional GLP-1 deficiency – α-gustducin-deficient (α-Gust−/−) mice, which exhibit attenuated nutrient-stimulated GLP-1 secretion, and GLP-1R-deficient mice. We show that the effect of RYGB to enhance glucose-stimulated GLP-1 secretion was greatly attenuated in α-Gust−/− mice. In both genetic models, RYGB reduced body weight and improved glucose homeostasis to levels observed in lean control mice. Therefore, GLP-1, acting through its classical GLP-1R or its bioactive metabolites, does not seem to be involved in the effects of RYGB on body weight and glucose homeostasis. PMID:24634822

A patient-centered electronic tool for weight loss outcomes after Roux-en-Y gastric bypass.

PubMed

Wood, G Craig; Benotti, Peter; Gerhard, Glenn S; Miller, Elaina K; Zhang, Yushan; Zaccone, Richard J; Argyropoulos, George A; Petrick, Anthony T; Still, Christopher D

2014-01-01

BACKGROUND. Current patient education and informed consent regarding weight loss expectations for bariatric surgery candidates are largely based on averages from large patient cohorts. The variation in weight loss outcomes illustrates the need for establishing more realistic weight loss goals for individual patients. This study was designed to develop a simple web-based tool which provides patient-specific weight loss expectations. METHODS. Postoperative weight measurements after Roux-en-Y gastric bypass (RYGB) were collected and analyzed with patient characteristics known to influence weight loss outcomes. Quantile regression was used to create expected weight loss curves (25th, 50th, and 75th %tile) for the 24 months after RYGB. The resulting equations were validated and used to develop web-based tool for predicting weight loss outcomes. RESULTS. Weight loss data from 2986 patients (2608 in the primary cohort and 378 in the validation cohort) were included. Preoperative body mass index (BMI) and age were found to have a high correlation with weight loss accomplishment (P < 0.0001 for each). An electronic tool was created that provides easy access to patient-specific, 24-month weight loss trajectories based on initial BMI and age. CONCLUSIONS. This validated, patient-centered electronic tool will assist patients and providers in patient teaching, informed consent, and postoperative weight loss management.

Symptomatic marginal ulcer disease after Roux-en-Y gastric bypass: incidence, risk factors and management.

PubMed

Coblijn, Usha K; Lagarde, Sjoerd M; de Castro, Steve M M; Kuiken, Sjoerd D; van Wagensveld, Bart A

2015-05-01

One of the long-term complications of laparoscopic Roux-and-Y gastric bypass (LRYGB) is the development of marginal ulcers (MU). The aim of the present study is to assess the incidence, risk factors, symptomatology and management of patients with symptomatic MU after LRYGB surgery. A consecutive series of patients who underwent a LRYGB from 2006 until 2011 were evaluated in this study. Signs of abdominal pain, pyrosis, nausea or other symptoms of ulcer disease were analysed. Acute symptoms of (perforated) MU such as severe abdominal pain, vomiting, melena and haematemesis were also collected. Patient baseline characteristics, medication and intoxications were recorded. Statistical analysis was performed to identify risk factors associated with MU. A total of 350 patients underwent a LRYGB. Minimal follow-up was 24 months. Twenty-three patients (6.6%) developed a symptomatic MU of which four (1.1%) presented with perforation. Smoking, the use of corticosteroids and non-steroidal anti-inflammatory drugs (NSAIDs) was significantly associated with the development of MU. Five out of 23 patients (22%) underwent surgery. All other patients could be treated conservatively. Marginal ulcers occurred in 6.6% of the patients after a LRYGB. Smoking, the use of corticosteroids and the use of NSAIDs were associated with an increased risk of MU. Most patients were managed conservatively.

Bile duct injury: management options during and after gallbladder surgery.

PubMed

Vecchio, R; MacFadyen, B V; Ricardo, A E

1998-06-01

Proper management of iatrogenic bile duct injuries is mandatory to avoid immediate or late life threatening sequelae. Results of surgery depend mainly on the type of injury, the detection of the injury, and the timing of the surgery. Lesions detected during cholecystectomy should be repaired immediately, preferably with an end-to-side biliary anastomosis, a Roux-en-Y bilio-enteric anastomosis, or by the insertion of a T-tube. Bile duct injuries detected in the postoperative phase require a multidisciplinary approach and an algorithm for treatment of each type of lesion is proposed. In bile peritonitis with biliary obstruction and/or transection and in tight long strictures, which develop several months after cholecystectomy, a Roux-en-Y hepatico-jejunostomy is the most commonly performed operation. Other surgical techniques include a "mucosal graft" procedure and intrahepatic biliary enteric anastomoses, which may be required in difficult high-biliary lesions. Endoscopy and/or interventional radiology offer the best treatment options in bile duct leaks and in short ductal strictures that involve less than 50% of the bile duct lumen. In these injuries, surgical management should be performed only in the failure of nonsurgical methods. Because these lesions involve complicated biliary surgery, therapeutic endoscopy, and interventional radiology, treatment should be performed where there is expertise in all three areas. Copyright 1998 W.B. Saunders Company.

Failure of mesenteric defect closure after Roux-en-Y gastric bypass.

PubMed

Hope, William W; Sing, Ronald F; Chen, Albert Y; Lincourt, Amy E; Gersin, Keith S; Kuwada, Timothy S; Heniford, B Todd

2010-01-01

Bowel obstructions following Roux-en-Y gastric bypass (RYGB) are a significant issue often caused by internal herniation. Controversy continues as to whether mesenteric defect closure is necessary to decrease the incidence of internal hernias after RYGB. Our purpose was to evaluate the effectiveness of closing the mesenteric defect at the jejunojejunostomy in patients who underwent RYGB by examining this potential space at reoperation for any reason. We retrospectively reviewed medical records of patients undergoing surgery after RYGB from August 1999 to October 2008 to determine the status of the mesentery at the jejunojejunostomy. Eighteen patients underwent surgery 2 to 19 months after open (n=8) or laparoscopic (n=10) RYGB. All patients had documented suture closure of their jejunojejunostomy at the time of RYGB. Permanent (n=12) or absorbable (n=6) sutures were used for closures. Patients lost 23.6 kg to 62.1 kg before a reoperation was required for a ventral hernia (n=8), cholecystectomy (n=4), abdominal pain (n=4), or small bowel obstruction (n=2). Fifteen of the 18 patients had open mesenteric defects at the jejunojejunostomy despite previous closure; none were the cause for reoperation. Routine suture closure of mesenteric defects after RYGB may not be an effective permanent closure likely due to the extensive fat loss and weight loss within the mesentery.

Mechanism Underlying the Weight Loss and Complications of Roux-en-Y Gastric Bypass. Review.

PubMed

Abdeen, G; le Roux, C W

2016-02-01

Various bariatric surgical procedures are effective at improving health in patients with obesity associated co-morbidities, but the aim of this review is to specifically describe the mechanisms through which Roux-en-Y gastric bypass (RYGB) surgery enables weight loss for obese patients using observations from both human and animal studies. Perhaps most but not all clinicians would agree that the beneficial effects outweigh the harm of RYGB; however, the mechanisms for both the beneficial and deleterious (for example postprandial hypoglycaemia, vitamin deficiency and bone loss) effects are ill understood. The exaggerated release of the satiety gut hormones, such as GLP-1 and PYY, with their central and peripheral effects on food intake has given new insight into the physiological changes that happen after surgery. The initial enthusiasm after the discovery of the role of the gut hormones following RYGB may need to be tempered as the magnitude of the effects of these hormonal responses on weight loss may have been overestimated. The physiological changes after RYGB are unlikely to be due to a single hormone, or single mechanism, but most likely involve complex gut-brain signalling. Understanding the mechanisms involved with the beneficial and deleterious effects of RYGB will speed up the development of effective, cheaper and safer surgical and non-surgical treatments for obesity.

The physiology underlying Roux-en-Y gastric bypass: a status report

PubMed Central

Bueter, Marco

2014-01-01

Obesity and its related comorbidities can be detrimental for the affected individual and challenge public health systems worldwide. Currently, the only available treatment options leading to clinically significant and maintained body weight loss and reduction in obesity-related morbidity and mortality are based on surgical interventions. This review will focus on two main clinical effects of Roux-en-Y gastric bypass (RYGB), namely body weight loss and change in eating behavior. Animal experiments designed to understand the underlying physiological mechanisms of these post-gastric bypass effects will be discussed. Where appropriate, reference will also be made to vertical sleeve gastrectomy. While caloric malabsorption and mechanical restriction seem not to be major factors in this respect, alterations in gut hormone levels are invariably found after RYGB. However, their causal role in RYGB effects on eating and body weight has recently been challenged. Other potential factors contributing to the RYGB effects include increased bile acid concentrations and an altered composition of gut microbiota. RYGB is further associated with remarkable changes in preference for different dietary components, such as a decrease in the preference for high fat or sugar. It needs to be noted, however, that in many cases, the question about the necessity of these alterations for the success of bariatric surgery procedures remains unanswered. PMID:25253084

Effect of weight loss after Roux-en-Y gastric bypass, on renal function and blood pressure in morbidly obese patients.

PubMed

Serpa Neto, Ary; Bianco Rossi, Felipe Martin; Dal Moro Amarante, Rodrigo; Alves Buriti, Nara; Cunha Barbosa Saheb, Gabriel; Rossi, Marçal

2009-01-01

Morbid obesity (MO) is associated with increased renal plasma flow (RPL) and glomerular filtration rate (GFR). This type of obesity usually does not respond to medical treatment, with bariatric surgery being the current treatment of choice. The present study aimed to evaluate whether weight loss may reverse the glomerular hyperfiltration of MO patients. This was a retrospective study of 140 patients submitted to Roux-en-Y gastric bypass (31.5% men, mean body mass index 46.17 +/- 5). Renal glomerular function and anthropometric and biochemical parameters were studied in patients before and 8 months after the surgery. GFR was determined by 24-hour urine samples. In the obese group, GFR before surgery was 148.7 +/- 35.2 ml/min. After the weight loss, GFR decreased to 113.8 +/- 31.7 ml/min (p<0.0001). Homeostasis model assessment-insulin resistance and glycosylated hemoglobin values were higher in MO with hyperfiltration. Weight loss was associated with reduction in blood pressure and GFR. It was found that the variation in systolic and diastolic blood pressure was a predictor of change in GFR. This study shows that obesity-related glomerular hyperfiltration ameliorates after weight loss. The improvement in hyperfiltration may prevent the development.

Degenerate RNA packaging signals in the genome of Satellite Tobacco Necrosis Virus: implications for the assembly of a T=1 capsid.

PubMed

Bunka, David H J; Lane, Stephen W; Lane, Claire L; Dykeman, Eric C; Ford, Robert J; Barker, Amy M; Twarock, Reidun; Phillips, Simon E V; Stockley, Peter G

2011-10-14

Using a recombinant, T=1 Satellite Tobacco Necrosis Virus (STNV)-like particle expressed in Escherichia coli, we have established conditions for in vitro disassembly and reassembly of the viral capsid. In vivo assembly is dependent on the presence of the coat protein (CP) N-terminal region, and in vitro assembly requires RNA. Using immobilised CP monomers under reassembly conditions with "free" CP subunits, we have prepared a range of partially assembled CP species for RNA aptamer selection. SELEX directed against the RNA-binding face of the STNV CP resulted in the isolation of several clones, one of which (B3) matches the STNV-1 genome in 16 out of 25 nucleotide positions, including across a statistically significant 10/10 stretch. This 10-base region folds into a stem-loop displaying the motif ACAA and has been shown to bind to STNV CP. Analysis of the other aptamer sequences reveals that the majority can be folded into stem-loops displaying versions of this motif. Using a sequence and secondary structure search motif to analyse the genomic sequence of STNV-1, we identified 30 stem-loops displaying the sequence motif AxxA. The implication is that there are many stem-loops in the genome carrying essential recognition features for binding STNV CP. Secondary structure predictions of the genomic RNA using Mfold showed that only 8 out of 30 of these stem-loops would be formed in the lowest-energy structure. These results are consistent with an assembly mechanism based on kinetically driven folding of the RNA. Copyright © 2011 Elsevier Ltd. All rights reserved.

In silico analysis of surface structure variation of PCV2 capsid resulting from loop mutations of its capsid protein (Cap)

PubMed Central

Wang, Aibing; Zhang, Lijie; Khayat, Reza

2016-01-01

Outbreaks of porcine circovirus (PCV) type 2 (PCV2)-associated diseases have caused substantial economic losses worldwide in the last 20 years. The PCV capsid protein (Cap) is the sole structural protein and main antigenic determinant of this virus. In this study, not only were phylogenetic trees reconstructed, but variations of surface structure of the PCV capsid were analysed in the course of evolution. Unique surface patterns of the icosahedral fivefold axes of the PCV2 capsid were identified and characterized, all of which were absent in PCV type 1 (PCV1). Icosahedral fivefold axes, decorated with Loops BC, HI and DE, were distinctly different between PCV2 and PCV1. Loops BC, determining the outermost surface around the fivefold axes of PCV capsids, had limited homology between Caps of PCV1 and PCV2. A conserved tyrosine phosphorylation motif in Loop HI that might be recognized by non-receptor tyrosine kinase(s) in vivo was present only in PCV2. Particularly, the concurrent presence of 60 pairs of the conserved tyrosine and a canonical PXXP motif on the PCV2 capsid surface could be a mechanism for PXXP motif binding to and activation of an SH3-domain-containing tyrosine kinase in host cells. Additionally, a conserved cysteine in Loop DE of the PCV2 Cap was substituted by an arginine in PCV1, indicating potentially distinct assembly mechanisms of the capsid in vitro between PCV1 and PCV2. Therefore, these unique patterns on the PCV2 capsid surface, absent in PCV1 isolates, might be related to cell entry, virus function and pathogenesis. PMID:27902320

In silico analysis of surface structure variation of PCV2 capsid resulting from loop mutations of its capsid protein (Cap).

PubMed

Wang, Naidong; Zhan, Yang; Wang, Aibing; Zhang, Lijie; Khayat, Reza; Yang, Yi

2016-12-01

Outbreaks of porcine circovirus (PCV) type 2 (PCV2)-associated diseases have caused substantial economic losses worldwide in the last 20 years. The PCV capsid protein (Cap) is the sole structural protein and main antigenic determinant of this virus. In this study, not only were phylogenetic trees reconstructed, but variations of surface structure of the PCV capsid were analysed in the course of evolution. Unique surface patterns of the icosahedral fivefold axes of the PCV2 capsid were identified and characterized, all of which were absent in PCV type 1 (PCV1). Icosahedral fivefold axes, decorated with Loops BC, HI and DE, were distinctly different between PCV2 and PCV1. Loops BC, determining the outermost surface around the fivefold axes of PCV capsids, had limited homology between Caps of PCV1 and PCV2. A conserved tyrosine phosphorylation motif in Loop HI that might be recognized by non-receptor tyrosine kinase(s) in vivo was present only in PCV2. Particularly, the concurrent presence of 60 pairs of the conserved tyrosine and a canonical PXXP motif on the PCV2 capsid surface could be a mechanism for PXXP motif binding to and activation of an SH3-domain-containing tyrosine kinase in host cells. Additionally, a conserved cysteine in Loop DE of the PCV2 Cap was substituted by an arginine in PCV1, indicating potentially distinct assembly mechanisms of the capsid in vitro between PCV1 and PCV2. Therefore, these unique patterns on the PCV2 capsid surface, absent in PCV1 isolates, might be related to cell entry, virus function and pathogenesis.

Whole-loop mitochondrial DNA D-loop sequence variability in Egyptian Arabian equine matrilines

PubMed Central

Hudson, William

2017-01-01

Background Egyptian Arabian horses have been maintained in a state of genetic isolation for over a hundred years. There is only limited genetic proof that the studbook records of female lines of Egyptian Arabian pedigrees are reliable. This study characterized the mitochondrial DNA (mtDNA) signatures of 126 horses representing 14 matrilines in the Egyptian Agricultural Organization (EAO) horse-breeding program. Findings Analysis of the whole D-loop sequence yielded additional information compared to hypervariable region-1 (HVR1) analysis alone, with 42 polymorphic sites representing ten haplotypes compared to 16 polymorphic sites representing nine haplotypes, respectively. Most EAO haplotypes belonged to ancient haplogroups, suggesting origin from a wide geographical area over many thousands of years, although one haplotype was novel. Conclusions Historical families share haplotypes and some individuals from different strains belonged to the same haplogroup: the classical EAO strain designation is not equivalent to modern monophyletic matrilineal groups. Phylogenetic inference showed that the foundation mares of the historical haplotypes were highly likely to have the same haplotypes as the animals studied (p > 0.998 in all cases), confirming the reliability of EAO studbook records and providing the opportunity for breeders to confirm the ancestry of their horses. PMID:28859174

Joint Services Electronics Program

NASA Astrophysics Data System (ADS)

Tinkham, Michael

1989-07-01

Topics addressed include: Electronic Theory of Semiconductor Alloys and Superlattices; Pressure Dependence of Photo Luminescence Excitation in GaAs/Al(x)Ga(1-x)As Multi-Quantum Wells; X Ray Surface Characterization; High Temperature Superconductivity; Quantum and Charging Phenomena in Mesoscopic Josephson Junctions; Nonlinear Dynamics of Electronic Neural Networks; Structural and Electronic Studies of Semiconductor Interfaces and Surfaces; Interaction of Ultrashort Laser Pulses with Semiconductor Surfaces; Multiphoton Vibrational Excitation of Molecules; Analytical and Numerical Determination of the Fields of Antennas near an Interface Between Two Half-Spaces with Significantly Different Wave Numbers; Theoretical Study of Lateral-Wave Propagation in Horizontally-Layered Media; Lateral Electromagnetic Waves from a Horizontal Antenna for Remote Sensing in the Ocean; Lateral Electromagnetic Pulses Generated by Horizontal and Vertical Dipoles on the Boundary Between Two Dielectrics; Theoretical Study of Isolated and Coupled Strip Antennas; Theoretical Study of Electromagnetic Pulses with a Slow Rate of Decay; Experimental Study of Electromagnetic Pulses with a Slow Rate of Decay; Properties of Closed Loops of Pseudodipoles; Asymptotic Solution for the Charge and Current Near the Open End of a Linear Tubular Antenna; Closed Loops of Parallel Coplanar Dipoles - Electrically Short Elements; Harmonic Generation in High-Temperature Superconductors and Resonant Closed Loops of Dipoles.

Non-Canonical G-quadruplexes cause the hCEB1 minisatellite instability in Saccharomyces cerevisiae

PubMed Central

Piazza, Aurèle; Cui, Xiaojie; Adrian, Michael; Samazan, Frédéric; Heddi, Brahim; Phan, Anh-Tuan; Nicolas, Alain G

2017-01-01

G-quadruplexes (G4) are polymorphic four-stranded structures formed by certain G-rich nucleic acids in vitro, but the sequence and structural features dictating their formation and function in vivo remains uncertain. Here we report a structure-function analysis of the complex hCEB1 G4-forming sequence. We isolated four G4 conformations in vitro, all of which bear unusual structural features: Form 1 bears a V-shaped loop and a snapback guanine; Form 2 contains a terminal G-triad; Form 3 bears a zero-nucleotide loop; and Form 4 is a zero-nucleotide loop monomer or an interlocked dimer. In vivo, Form 1 and Form 2 differently account for 2/3rd of the genomic instability of hCEB1 in two G4-stabilizing conditions. Form 3 and an unidentified form contribute to the remaining instability, while Form 4 has no detectable effect. This work underscores the structural polymorphisms originated from a single highly G-rich sequence and demonstrates the existence of non-canonical G4s in cells, thus broadening the definition of G4-forming sequences. DOI: http://dx.doi.org/10.7554/eLife.26884.001 PMID:28661396

Pathophysiology and Toxicokinetic Studies of Blue-Green Algae Intoxication in the Swine Model

DTIC Science & Technology

1987-08-31

bovine aer, albamin caused similar reductions !u toxicity, suggesting nonspecific protein binding. Saturation at the N-methyldehydroalanine of MCYST-A...need to conserve toxin and the goal of creating a model for naturally occurring toxicosis caused us to evaluate the oral administration of microcystin...the isolated ileal loop preparation. Pancreatic enzymes and protein-binding were examined as 2 possible causes for the low oral toxicity of MCYST-A

Integrated passive/active vibration absorber for multi-story buildings

NASA Technical Reports Server (NTRS)

Lee-Glauser, Gina J.; Ahmadi, Goodarz; Horta, Lucas G.

1995-01-01

Passive isolator, active vibration absorber, and an integrated passive/active (hybrid) control are studied for their effectiveness in reducing structural vibration under seismic excitations. For the passive isolator, a laminated rubber bearing base isolator which has been studied and used extensively by researchers and seismic designers is considered. An active vibration absorber concept, which can provide guaranteed closed-loop stability with minimum knowledge of the controlled system, is used to reduce the passive isolator displacement and to suppress the top floor vibration. A three-story building model is used for the numerical simulation. The performance of an active vibration absorber and a hybrid vibration controller in reducing peak structural responses is compared with the passively isolated structural response and with absence of vibration control systems under the N00W component of El Centro 1940 and N90W component of the Mexico City earthquake excitation records. The results show that the integrated passive/active vibration control system is most effective in suppressing the peak structural acceleration for the El Centro 1940 earthquake when compared with the passive or active vibration absorber alone. The active vibration absorber, however, is the only system that suppresses the peak acceleration of the structure for the Mexico City 1985 earthquake.

Evaluation and control of microbial and chemical contamination in dialysis water plants of Italian nephrology wards.

PubMed

Totaro, M; Casini, B; Valentini, P; Miccoli, M; Giorgi, S; Porretta, A; Privitera, G; Lopalco, P L; Baggiani, A

2017-10-01

Patients receiving haemodialysis are exposed to a large volume of dialysis fluid. The Italian Society of Nephrology (ISN) has published guidelines and microbial quality standards on dialysis water (DW) and solutions to ensure patient safety. To identify microbial and chemical hazards, and evaluate the quality of disinfection treatment in DW plants. In 2015 and 2016, water networks and DW plants (closed loop and online monitors) of nine dialysis wards of Italian hospitals, hosting 162 dialysis beds overall, were sampled on a monthly basis to determine the parameters provided by ISN guidelines. Chlorinated drinking water was desalinated by reverse osmosis and distributed to the closed loop which feeds all online monitors. Disinfection with peracetic acid was performed in all DW plants on a monthly basis. Over the 24-month study period, seven out of nine DW plants (78%) recorded negative results for all investigated parameters. Closed loop contamination with Burkholderia cepacia was detected in a DW plant from January 2015 to March 2015. Pseudomonas aeruginosa was isolated from March 2016 to May 2016 in the closed loop of another DW plant. These microbial contaminations were eradicated by shock disinfection with sodium hypochlorite and peracetic acid, followed by water flushing. These results highlight the importance of chemical and physical methods of DW disinfection. The maintenance of control measures in water plants hosted in dialysis wards ensures a microbial risk reduction for all dialysis patients. Copyright © 2017 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

The cysteines of the extracellular loop are crucial for trafficking of human organic cation transporter 2 to the plasma membrane and are involved in oligomerization.

PubMed

Brast, Sabine; Grabner, Alexander; Sucic, Sonja; Sitte, Harald H; Hermann, Edwin; Pavenstädt, Hermann; Schlatter, Eberhard; Ciarimboli, Giuliano

2012-03-01

Human organic cation transporter 2 (hOCT2) is involved in transport of many endogenous and exogenous organic cations, mainly in kidney and brain cells. Because the quaternary structure of transmembrane proteins plays an essential role for their cellular trafficking and function, we investigated whether hOCT2 forms oligomeric complexes, and if so, which part of the transporter is involved in the oligomerization. A yeast 2-hybrid mating-based split-ubiquitin system (mbSUS), fluorescence resonance energy transfer, Western blot analysis, cross-linking experiments, immunofluorescence, and uptake measurements of the fluorescent organic cation 4-(4-(dimethylamino)styryl)-N-methylpyridinium were applied to human embryonic kidney 293 (HEK293) cells transfected with hOCT2 and partly also to freshly isolated human proximal tubules. The role of cysteines for oligomerization and trafficking of the transporter to the plasma membranes was investigated in cysteine mutants of hOCT2. hOCT2 formed oligomers both in the HEK293 expression system and in native human kidneys. The cysteines of the large extracellular loop are important to enable correct folding, oligomeric assembly, and plasma membrane insertion of hOCT2. Mutation of the first and the last cysteines of the loop at positions 51 and 143 abolished oligomer formation. Thus, the cysteines of the extracellular loop are important for correct trafficking of the transporter to the plasma membrane and for its oligomerization.

Development of real-time PCR and loop-mediated isothermal amplification (LAMP) assays for the differential detection of digital dermatitis associated treponemes.

PubMed

Anklam, Kelly; Kulow, Megan; Yamazaki, Wataru; Döpfer, Dörte

2017-01-01

Bovine digital dermatitis (DD) is a severe infectious cause of lameness in cattle worldwide, with important economic and welfare consequences. There are three treponeme phylogroups (T. pedis, T. phagedenis, and T. medium) that are implicated in playing an important causative role in DD. This study was conducted to develop real-time PCR and loop-mediated isothermal amplification (LAMP) assays for the detection and differentiation of the three treponeme phylogroups associated with DD. The real-time PCR treponeme phylogroup assays targeted the 16S-23S rDNA intergenic space (ITS) for T. pedis and T. phagedenis, and the flagellin gene (flaB2) for T. medium. The 3 treponeme phylogroup LAMP assays targeted the flagellin gene (flaB2) and the 16S rRNA was targeted for the Treponeme ssp. LAMP assay. The real-time PCR and LAMP assays correctly detected the target sequence of all control strains examined, and no cross-reactions were observed, representing 100% specificity. The limit of detection for each of the three treponeme phylogroup real-time PCR and LAMP assays was ≤ 70 fg/μl. The detection limit for the Treponema spp. LAMP assay ranged from 7-690 fg/μl depending on phylogroup. Treponemes were isolated from 40 DD lesion biopsies using an immunomagnetic separation culture method. The treponeme isolation samples were then subjected to the real-time PCR and LAMP assays for analysis. The treponeme phylogroup real-time PCR and LAMP assay results had 100% agreement, matching on all isolation samples. These results indicate that the developed assays are a sensitive and specific test for the detection and differentiation of the three main treponeme phylogroups implicated in DD.

Isolated quasi-axisymmetric sunspots

NASA Astrophysics Data System (ADS)

Koutchmy, Serge; Le Piouffle, Vincent

2009-04-01

We briefly review the question of the origin, during a sunspot cycle, of well isolated sunspots. This includes big sunspots like the one observed in Nov. 2006. An overall axi-symmetric morphology is not perfectly observed when the morphological details of both the umbra and of the penumbra are considered. This is especially the case of umbral dots always present inside the core of a sunspot and also of penumbral filaments with non radial parts. However, the distribution of the surrounding fields, including deep layers, the occurrence of persistent coherent running penumbral waves, the magnetic moat behavior, the bright ring phenomena, etc. seem to justify a revival of the naive former but revised (converging motions are considered) Larmor model of a sunspot (as suggested by Lorrain et al. 2006). To discuss the “emergence” of single isolated sunspots from deep layers we performed a quasi-statistical analysis limited to cycle 23. It is based on MDI data taken in the continuum, using the accompanying magnetograms to check our assertion. Surprisingly, single sunspots are definitely and preferably found to occur at low latitude and during the descending branch of the cycle. To explain our observations we speculate about the behavior of the deeply seated magnetic loop, following the original idea of H. Alfven (with whirl rings which follow the global dipolar field when approaching the surface). It could lead to a closed loop approximately orthogonal to the local radius, similar to “smoke rings” arriving at the surface of the Sun and sometimes also called a plasmoid. The ring will only very weakly feel the destabilizing Coriolis force, when emerging at very low latitudes, which seems consistent with our observations.

Development of real-time PCR and loop-mediated isothermal amplification (LAMP) assays for the differential detection of digital dermatitis associated treponemes

PubMed Central

Kulow, Megan; Yamazaki, Wataru; Döpfer, Dörte

2017-01-01

Bovine digital dermatitis (DD) is a severe infectious cause of lameness in cattle worldwide, with important economic and welfare consequences. There are three treponeme phylogroups (T. pedis, T. phagedenis, and T. medium) that are implicated in playing an important causative role in DD. This study was conducted to develop real-time PCR and loop-mediated isothermal amplification (LAMP) assays for the detection and differentiation of the three treponeme phylogroups associated with DD. The real-time PCR treponeme phylogroup assays targeted the 16S-23S rDNA intergenic space (ITS) for T. pedis and T. phagedenis, and the flagellin gene (flaB2) for T. medium. The 3 treponeme phylogroup LAMP assays targeted the flagellin gene (flaB2) and the 16S rRNA was targeted for the Treponeme ssp. LAMP assay. The real-time PCR and LAMP assays correctly detected the target sequence of all control strains examined, and no cross-reactions were observed, representing 100% specificity. The limit of detection for each of the three treponeme phylogroup real-time PCR and LAMP assays was ≤ 70 fg/μl. The detection limit for the Treponema spp. LAMP assay ranged from 7–690 fg/μl depending on phylogroup. Treponemes were isolated from 40 DD lesion biopsies using an immunomagnetic separation culture method. The treponeme isolation samples were then subjected to the real-time PCR and LAMP assays for analysis. The treponeme phylogroup real-time PCR and LAMP assay results had 100% agreement, matching on all isolation samples. These results indicate that the developed assays are a sensitive and specific test for the detection and differentiation of the three main treponeme phylogroups implicated in DD. PMID:28542573

Dephasing Catastrophe in 4-ε Dimensions: A Possible Instability of the Ergodic (Many-Body-Delocalized) Phase.

PubMed

Liao, Yunxiang; Foster, Matthew S

2018-06-08

In two dimensions, dephasing by a bath cuts off Anderson localization that would otherwise occur at any energy density for fermions with disorder. For an isolated system with short-range interactions, the system can be its own bath, exhibiting diffusive (non-Markovian) thermal density fluctuations. We recast the dephasing of weak localization due to a diffusive bath as a self-interacting polymer loop. We investigate the critical behavior of the loop in d=4-ε dimensions, and find a nontrivial fixed point corresponding to a temperature T^{*}∼ε>0 where the dephasing time diverges. Assuming that this fixed point survives to ε=2, we associate it with a possible instability of the ergodic phase. Our approach may open a new line of attack against the problem of the ergodic to many-body-localized phase transition in d>1 spatial dimensions.

Dephasing Catastrophe in 4 -ɛ Dimensions: A Possible Instability of the Ergodic (Many-Body-Delocalized) Phase

NASA Astrophysics Data System (ADS)

Liao, Yunxiang; Foster, Matthew S.

2018-06-01

In two dimensions, dephasing by a bath cuts off Anderson localization that would otherwise occur at any energy density for fermions with disorder. For an isolated system with short-range interactions, the system can be its own bath, exhibiting diffusive (non-Markovian) thermal density fluctuations. We recast the dephasing of weak localization due to a diffusive bath as a self-interacting polymer loop. We investigate the critical behavior of the loop in d =4 -ɛ dimensions, and find a nontrivial fixed point corresponding to a temperature T*˜ɛ >0 where the dephasing time diverges. Assuming that this fixed point survives to ɛ =2 , we associate it with a possible instability of the ergodic phase. Our approach may open a new line of attack against the problem of the ergodic to many-body-localized phase transition in d >1 spatial dimensions.

Detection and identification of Brettanomyces/Dekkera sp. yeasts with a loop-mediated isothermal amplification method.

PubMed

Hayashi, Nobuyuki; Arai, Ritsuko; Tada, Setsuzo; Taguchi, Hiroshi; Ogawa, Yutaka

2007-01-01

Primer sets for a loop-mediated isothermal amplification (LAMP) method were developed to specifically identify each of the four Brettanomyces/Dekkera species, Dekkera anomala, Dekkera bruxellensis, Dekkera custersiana and Brettanomyces naardenensis. Each primer set was designed with target sequences in the ITS region of the four species and could specifically amplify the target DNA of isolates from beer, wine and soft drinks. Furthermore, the primer sets differentiated strains of the target species from strains belonging to other species, even within the genus Brettanomyces/Dekkera. Moreover, the LAMP method with these primer sets could detect about 1 x 10(1) cfu/ml of Brettanomyces/Dekkera yeasts from suspensions in distilled water, wine and beer. This LAMP method with primer sets for the identification of Brettanomyces/Dekkera yeasts is advantageous in terms of specificity, sensitivity and ease of operation compared with standard PCR methods.

Organization of feed-forward loop motifs reveals architectural principles in natural and engineered networks.

PubMed

Gorochowski, Thomas E; Grierson, Claire S; di Bernardo, Mario

2018-03-01

Network motifs are significantly overrepresented subgraphs that have been proposed as building blocks for natural and engineered networks. Detailed functional analysis has been performed for many types of motif in isolation, but less is known about how motifs work together to perform complex tasks. To address this issue, we measure the aggregation of network motifs via methods that extract precisely how these structures are connected. Applying this approach to a broad spectrum of networked systems and focusing on the widespread feed-forward loop motif, we uncover striking differences in motif organization. The types of connection are often highly constrained, differ between domains, and clearly capture architectural principles. We show how this information can be used to effectively predict functionally important nodes in the metabolic network of Escherichia coli . Our findings have implications for understanding how networked systems are constructed from motif parts and elucidate constraints that guide their evolution.

Model Predictive Control-based Optimal Coordination of Distributed Energy Resources

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mayhorn, Ebony T.; Kalsi, Karanjit; Lian, Jianming

2013-01-07

Distributed energy resources, such as renewable energy resources (wind, solar), energy storage and demand response, can be used to complement conventional generators. The uncertainty and variability due to high penetration of wind makes reliable system operations and controls challenging, especially in isolated systems. In this paper, an optimal control strategy is proposed to coordinate energy storage and diesel generators to maximize wind penetration while maintaining system economics and normal operation performance. The goals of the optimization problem are to minimize fuel costs and maximize the utilization of wind while considering equipment life of generators and energy storage. Model predictive controlmore » (MPC) is used to solve a look-ahead dispatch optimization problem and the performance is compared to an open loop look-ahead dispatch problem. Simulation studies are performed to demonstrate the efficacy of the closed loop MPC in compensating for uncertainties and variability caused in the system.« less

Model Predictive Control-based Optimal Coordination of Distributed Energy Resources

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mayhorn, Ebony T.; Kalsi, Karanjit; Lian, Jianming

2013-04-03

Distributed energy resources, such as renewable energy resources (wind, solar), energy storage and demand response, can be used to complement conventional generators. The uncertainty and variability due to high penetration of wind makes reliable system operations and controls challenging, especially in isolated systems. In this paper, an optimal control strategy is proposed to coordinate energy storage and diesel generators to maximize wind penetration while maintaining system economics and normal operation performance. The goals of the optimization problem are to minimize fuel costs and maximize the utilization of wind while considering equipment life of generators and energy storage. Model predictive controlmore » (MPC) is used to solve a look-ahead dispatch optimization problem and the performance is compared to an open loop look-ahead dispatch problem. Simulation studies are performed to demonstrate the efficacy of the closed loop MPC in compensating for uncertainties and variability caused in the system.« less

Organization of feed-forward loop motifs reveals architectural principles in natural and engineered networks

PubMed Central

Grierson, Claire S.

2018-01-01

Network motifs are significantly overrepresented subgraphs that have been proposed as building blocks for natural and engineered networks. Detailed functional analysis has been performed for many types of motif in isolation, but less is known about how motifs work together to perform complex tasks. To address this issue, we measure the aggregation of network motifs via methods that extract precisely how these structures are connected. Applying this approach to a broad spectrum of networked systems and focusing on the widespread feed-forward loop motif, we uncover striking differences in motif organization. The types of connection are often highly constrained, differ between domains, and clearly capture architectural principles. We show how this information can be used to effectively predict functionally important nodes in the metabolic network of Escherichia coli. Our findings have implications for understanding how networked systems are constructed from motif parts and elucidate constraints that guide their evolution. PMID:29670941

LAMP-PCR detection of ochratoxigenic Aspergillus species collected from peanut kernel.

PubMed

Al-Sheikh, H M

2015-01-30

Over the last decade, ochratoxin A (OTA) has been widely described and is ubiquitous in several agricultural products. Ochratoxins represent the second-most important mycotoxin group after aflatoxins. A total of 34 samples were surveyed from 3 locations, including Mecca, Madina, and Riyadh, Saudi Arabia, during 2012. Fungal contamination frequency was determined for surface-sterilized peanut seeds, which were seeded onto malt extract agar media. Aspergillus niger (35%), Aspergillus ochraceus (30%), and Aspergillus carbonarius (25%) were the most frequently observed Aspergillius species, while Aspergillus flavus and Aspergillus phoenicis isolates were only infrequently recovered and in small numbers (10%). OTA production was evaluated on yeast extract sucrose medium, which revealed that 57% of the isolates were A. niger and 60% of A. carbonarius isolates were OTA producers; 100% belonged to A. ochraceus. Only one isolate, morphologically identified as A. carbonarius, and 3 A. niger isolates unstably produced OTA. A polymerase chain reaction (PCR)-based identification and detection assay was used to identify A. ochraceus isolates. Using the primer sets OCRA1/OCRA2, 400-base pair PCR fragments were produced only when genomic DNA from A. ochraceus isolates was used. Recently, the loop-mediated isothermal amplification assay using recombinase polymerase amplification chemistry was used for A. carbonarius and A. niger DNA identification. As a non-gel-based technique, the amplification product was directly visualized in the reaction tube after adding calcein for naked-eye examination.

Characterization and Performance Comparison of Low-Voltage, High-Speed, Push-Pull and Traveling-Wave Silicon Mach-Zehnder Modulators

DTIC Science & Technology

2014-03-27

2Fieeexplore.ieee.org%2Fxpls%2Fabs all.jsp%3Farnumber%3D5875447 [7] D. Marris- Morini , L. Vivien, G. Rasigade, J.-M. Fedeli, E. Cassan, X. Le Roux, P. Crozat...3rd ed., B. Zobrist, Ed. Wiley, 2002. [26] M. Ziebell, D. Marris- Morini , G. Rasigade, P. Crozat, J.-M. Fedeli, E. Cassan, and L. Vivien, “Low-loss and

Targeting Paclitaxel-Loaded Nanoparticles to Ovarian Cancer

DTIC Science & Technology

2010-05-01

nanoparticle of »20 nm in aqueous solutions as determined by dynamic light scattering (2) Figure 1. Figure 1 In our studies, this new nanoparticle...Selective Integrin avb3 Antagonists. J Am Chem Soc. 1996;118:7461-72. 11. Jolimaitre P , Poirier C, Richard A, Blanpain A, Delord B, Roux D, et al...Tissue-penetrating delivery of compounds and nanoparticles into tumors. Cancer Cell. 2009;16:510-20. 15. Laakkonen P , Porkka K, Hoffman JA, Ruoslahti

Data Investigation of Bariatric Surgery Outcome and Economic Savings

DTIC Science & Technology

2010-12-15

Age, squared Age as well as interactions for Sex/Age, Sex/BMI and BMI/Age. Data were from the NCHS National Health Interview Survey ( NHIS ...National Health and Nutrition Examination Survey NHIS – National Health Interview Survey OLS – Ordinary Least Squares ORYGB – Open Roux en Y Gastric...a household are reported by a single household member.76 The sampling frame is the National Household Interview Survey ( NHIS ). The NHIS sample

Carving nature at its joints or cutting its effective loops? On the dangers of trying to disentangle intertwined mental processes.

PubMed

Goldstone, Robert L; de Leeuw, Joshua R; Landy, David H

2016-01-01

Attention is often inextricably intertwined with perception, and it is deployed not only to spatial regions, but also to sensory dimensions, learned dimensions, and learned complex configurations. Firestone & Scholl's (F&S)'s tactic of isolating visual perceptual processes from attention and action has the negative consequence of neglecting interactions that are critically important for allowing people to perceive their world in efficient and useful ways.

Optical interferometer testbed

NASA Technical Reports Server (NTRS)

Blackwood, Gary H.

1991-01-01

Viewgraphs on optical interferometer testbed presented at the MIT Space Research Engineering Center 3rd Annual Symposium are included. Topics covered include: space-based optical interferometer; optical metrology; sensors and actuators; real time control hardware; controlled structures technology (CST) design methodology; identification for MIMO control; FEM/ID correlation for the naked truss; disturbance modeling; disturbance source implementation; structure design: passive damping; low authority control; active isolation of lightweight mirrors on flexible structures; open loop transfer function of mirror; and global/high authority control.

Development of Loop-Mediated Isothermal Amplification (LAMP) Assays for Rapid Detection of Ehrlichia ruminantium

PubMed Central

2010-01-01

Background The rickettsial bacterium Ehrlichia ruminantium is the causative agent of heartwater, a potential zoonotic disease of ruminants transmitted by ticks of the genus Amblyomma. The disease is distributed in nearly all of sub-Saharan Africa and some islands of the Caribbean, from where it threatens the American mainland. This report describes the development of two different loop-mediated isothermal amplification (LAMP) assays for sensitive and specific detection of E. ruminantium. Results Two sets of LAMP primers were designed from the pCS20 and sodB genes. The detection limits for each assay were 10 copies for pCS20 and 5 copies for sodB, which is at least 10 times higher than that of the conventional pCS20 PCR assay. DNA amplification was completed within 60 min. The assays detected 16 different isolates of E. ruminantium from geographically distinct countries as well as two attenuated vaccine isolates. No cross-reaction was observed with genetically related Rickettsiales, including zoonotic Ehrlichia species from the USA. LAMP detected more positive samples than conventional PCR but less than real-time PCR, when tested with field samples collected in sub-Saharan countries. Conclusions Due to its simplicity and specificity, LAMP has the potential for use in resource-poor settings and also for active screening of E. ruminantium in both heartwater-endemic areas and regions that are at risk of contracting the disease. PMID:21087521

Simultaneous subtyping and pathotyping of avian influenza viruses in chickens in Taiwan using reverse transcription loop-mediated isothermal amplification and microarray

PubMed Central

WANG, Lih-Chiann; HUANG, Dean; CHEN, Hui-Wen

2016-01-01

The H6N1 avian influenza virus has circulated in Taiwan for more than 40 years. The sporadic activity of low pathogenic H5N2 virus has been noted since 2003, and highly pathogenic H5N2 avian influenza virus has been detected since 2008. Ressortant viruses between H6N1 and H5N2 viruses have become established and enzootic in chickens throughout Taiwan. Outbreaks caused by Novel highly pathogenic H5 avian influenza viruses whose HA genes were closely related to that of the H5N8 virus isolated from ducks in Korea in 2014 were isolated from outbreaks in Taiwan since early 2015. The avian influenza virus infection status is becoming much more complicated in chickens in Taiwan. This necessitates a rapid and simple approach to detect and differentiate the viruses that prevail. H6N1, H5N2 and novel H5 viruses were simultaneously subtyped and pathotyped in this study using reverse transcription loop-mediated isothermal amplification and microarray, with detection limits of 10°, 101 and 10° viral copy numbers, respectively. The microarray signals were read by the naked eye with no expensive equipment needed. The method developed in this study could greatly improve avian influenza virus surveillance efficiency. PMID:27086860

Detailed flow, hydrometeor and lightning characteristics of an isolated thunderstorm during COPS

NASA Astrophysics Data System (ADS)

Schmidt, K.; Hagen, M.; Höller, H.; Richard, E.; Volkert, H.

2012-04-01

The three-hour life-cycle of the isolated thunderstorm on 15 July 2007 during the Convective and Orographically-induced Precipitation Study (COPS) is documented in detail, with a special emphasis on the rapid develpment and mature phases. Remote sensing techniques as 5-minute rapid scans from geostationary satellites, combined Doppler-retrievals from up to four Doppler-radars, the polarimetric determination of hydrometeors and spatio-temporal occurrences of lightning strokes are employed to arrive at a synoptic quantification of the physical parameters of this, for the COPS period, rare event. Inner cloud flow fields are available, gridded on a 500-m-mesh, at four consecutive times separated by 15 minute-intervals (14:35, 14:50, 15:05, 15:20). They contain horizontal winds of up to 15 m/s and updrafts exceeding 4 m/s, the latter collocated with lightning strokes. Profiles of flow and hydrometeor statistics over the entire cloud volume provide reference data for high-resolution, real-world, episode-type numerical weather predicition runs in research mode. Exemplary results are obtained by applying the Meso-NH modelling system in a four-fold nested configuration with a horizontal mesh-size of 500 m. The study embarks from two multi-channel time-lapse movie-loops from geostationary satellite imagery, which provide an intuitive distinction of six phases making up the entire life-cycle of the tunderstorm. It concludes with a triple image-loop, juxtaposing a close-up of the cloud motion seen by Meteosat, simulated brightness temperatures (as a proxy for clouds seen by the infrared satellite channel), and a perspective view on the model generated system of cloud cells. By employing the motion-geared human visual system, such multiple image loops provide a high, and as yet hardly utilised potential for a well-grounded selection of further sensitivity experiments in the modelling community.

Overproduction of active efflux pump and variations of OprD dominate in imipenem-resistant Pseudomonas aeruginosa isolated from patients with bloodstream infections in Taiwan.

PubMed

Kao, Cheng-Yen; Chen, Shu-Sheng; Hung, Kuei-Hsiang; Wu, Hsiu-Mei; Hsueh, Po-Ren; Yan, Jing-Jou; Wu, Jiunn-Jong

2016-06-13

The emergence of imipenem-resistant Pseudomonas aeruginosa (IRPA) has become a great concern worldwide. The aim of this study was to investigate resistance mechanisms associated with bloodstream isolated IRPA strains in Taiwan. A total of 78 non-duplicated IRPA isolates were isolated from patients with bloodstream infection. The average prevalence of imipenem-resistance in those isolates was 5.9 % during a 10-year longitudinal surveillance in Taiwan. PFGE results showed high clonal diversity among the 78 isolates. VIM-2, VIM-3, OXA-10, and OXA-17 β-lactamases were identified in 2 (2.6 %), 3 (3.8 %), 2 (2.6 %), and 1 (1.3 %) isolates, respectively. Active efflux pumps, AmpC β-lactamase overproduction, and extended-spectrum AmpC cephalosporinases (ESACs) were found in 58 (74.4 %), 25 (32.1 %) and 15 (19.2 %) of IRPA isolates, respectively. oprD mutations with amino acid substitution, shortened putative loop L7, premature stop codon caused by point mutation, frameshift by nucleotide insertion or deletion, and interruption by insertion sequence were found in 19 (24.4 %), 18 (23.1 %), 15 (19.2 %), 14 (17.9 %), and 10 (12.8 %) of isolates, respectively. This study suggests that alterations in the OprD protein and having an active efflux pump are the main mechanisms associated with bloodstream isolated IRPA. Overproduction of AmpC, ESACs, and the presence of VIM- and OXA-type β-lactamases play additional roles in reduced susceptibility to imipenem in P. aeruginosa isolates in Taiwan.

Outcomes on quality of life, weight loss, and comorbidities after Roux-en-Y gastric bypass.

PubMed

Costa, Roberto Coelho Netto da Cunha; Yamaguchi, Nagamassa; Santo, Marco Aurelio; Riccioppo, Daniel; Pinto-Junior, Paulo Engler

2014-01-01

Bariatric surgery has become the most effective method for producing weight loss in obese patients. The evaluation of improvement of comorbidities and changes in the quality of life are important outcome factors; however, it is necessary to investigate whether they persist over the long term. A cross-sectional study was conducted on 143 obese patients from our institution from February 2007 to February 2008. These patients were divided into five independent groups, one being a control group, plus four other groups with 1, 2, 3, 4 or more years following surgical Roux-en-Y gastric bypass with a silicon ring banded. quality of life forms and anthropometric measurements were performed and its scores correlated with social factors, weight loss success, and status of obesity-related conditions. For the group that was 1 year postoperative, a significant percentage of excess body weight loss (EBWL%) of 81.7% was observed. The groups with 2, 3, 4 or more years of post-surgical follow-up showed a EBWL decline, but without significant difference. The main comorbidity percentages in all patients who had the surgery was as follows: 69.7% for hypertension; 88.2% for diabetes mellitus; and 27.5% for arthropathy. There was a significant decrease in the rate for diabetes resolution (P = 0.035) observed by evolutionary assessment of the comorbidity resolution. The results obtained by BAROS were good, very good, or excellent in more than 96% of patients in all evaluations that were performed. The use of the Moorehead-Ardelt Questionnaire (M/A) demonstrated improvement in the quality of life. Moreover, the quality of life, when evaluated through SF-36, also showed improvement in all related areas after 1 year; however, after 4 years, improvement remained elevated only in the areas of general state of health and functional capacity. The Roux-en-Y gastric bypass procedure was able to achieve EBWL of 81.7% after 1 year following surgery, remaining steady with little decline after this period. Important resolution of comorbidities, such as hypertension and diabetes, was also seen. Immediate surgical outcomes assessed by SF-36 and M/A in the area of quality of life were satisfactory, but the general state of health and functional capacity areas were sustained satisfactory at a later time only.