Effect of high NaCl intake on Na+ and K+ transport in the rabbit distal convoluted tubule

Morphological studies have demonstrated that a chronic increase in distal Na⁺ delivery causes hypertrophy of the distal convoluted tubule (DCT). To examine whether high NaCl-intake also causes functional changes in the well defined DCT, we measured transmural voltage (V _T), lumen-to-bath Na⁺ flux (J _Na(LB)), and net K⁺ secretion (J _K(net)) in DCTs obtained from control rabbits and those on high NaCl-intake diets. The lumen negativeV _T was significantly greater in the high NaCl group than in the control group. The net K⁺ secretion (pmol mm^–1 min^–1) was greater in the high NaCl-intake group (54.1±13.0 vs 14.7±5.6). The K⁺ permeabïlities in both luminal and basolateral DCT membranes, as assessed by the K⁺-induced transepithelial voltage deflection inhibitable with Ba²⁺, were increased in the experimental group. The lumen-to-bath²²Na flux (pmol mm^–1 min^–1) was also greater in the experimental group (726±119 vs 396±65). TheV _T component inhibitable with amiloride was also elevated in the high NaCl-intake group. Furthermore, Na⁺–K⁺-ATPase activity of the DCT was higher in the experimental than in the control group. We conclude that high NaCl intake increases both Na⁺ reabsorption and K⁺ secretion by the DCT. This phenomenon is associated with an increased Na⁺–K⁺-ATPase activity along with increased Na⁺ and K⁺ permeabilities of the luminal membrane, and an increase in the K⁺ permeability of the basolateral membrane. Cellular mechanisms underlying these functional changes remain to be established.     

A simple method for multiple fluid exchange

A simple device for fluid exchange is described, which allows the exchange of an unlimited number of solutions at low (10–1000 nl/min) constant perfusion rate. The applicability of the system has been tested in microperfusion experiments of rat distal tubules. At a luminal perfusion rate of 40 nl/min, the lag time was some 20 sec and 80 % fluid exchange time some 3 sec. Simple modification allows further reduction of the lag time. Under control conditions, the potential difference across the late distal tubule (PDte) approaches –19.4±2.5 mV (n = 27). Increase of luminal potassium concentration from 5.4 to 40 mmol/l hyperpolanzes PDte to –29.9±4.3 mV (n = 8). Amiloride (10 mol/l) leads to a reversible depolarization to –3.2±1.0 mV (n = 19), barium (1 mmol/l) to a reversible hyperpolarization to –25.8±2.6 mV (n = 19). As expected, PDte is largely created by amiloride sensitive sodium channels and is partially blunted by barium sensitive potassium channels.     

经皮微创植入锁定钢板治疗胫骨远端骨折

目的探讨应用胫骨远端锁定钢板经皮微创植入治疗胫骨远端骨折的疗效。方法自2010年1月~2012年12月应用小切口植入胫骨远端锁定钢板治疗32例胫骨远端骨折,男19例,女13例,年龄13~77岁,平均39.8岁。其中开放性骨折4例,闭合性骨折28例,均为新鲜骨折。结果 29例获得随访,随访时间6~15个月,平均11.7个月。所有骨折均愈合,平均愈合时间为13.6周,均无感染、骨不连、钢板松动等并发症。按照Mazur踝关节功能评分:优19例,良8例,可2例,优良率为93.1%。结论微创钢板内固定手术创伤小,固定可靠,骨折愈合率高,符合生物学固定原则。     

Conservative surgery in Zollinger-Ellison syndrome: report of a case with an eight-year follow-up

The patient described here, with malignant non-beta islet cell tumor of the head of the pancreas, was treated by resection of the tumor and metastases. Additional pathology of perforated duodenal ulcer and pyloric stenosis required vagotomy and pyloroplasty. The maintenance of normal gastrin levels after the operation indicates a good prognosis. We believe that the low-risk Zollinger-Ellison patient should be treated surgically and the tumor removed. When no tumor can be detected, parietal cell vagotomy should be performed to assist the pharmacological control of the gastric acid hypersecretion. Extensive surgery, such as total gastrectomy, is no longer the treatment of choice and is reserved for the so-called "cimetidine failure."     

Preoperative management of obese patients undergoing bariatric surgery: Role of endoscopy and Helicobacter eradication

BackgroundObesity is a pandemic disease associated to severe health problems. Management is usually multimodal, but many patients eventually need surgery to reduce weight. Many guidelines recommend endoscopy prior to surgery. This study reviews a series of patients undergoing sleeve gastrectomy to see whether endoscopy performance and histopathological findings influence surgery outcome.Material and methodsRetrospective series of patients undergoing sleeve gastrectomy as bariatric procedure at a single institution. We have reviewed the demographic data, the associated pathologies, endoscopic findings prior to surgery, histopathological findings in the surgical resection specimen and postoperative complication rate.Results259 patients fulfilled criteria for the study. Over 70% were women and the mean age was 46.9 (SD 9.8). Preoperative endoscopy was performed in 28.9% of the patients and biopsy only in 19.3%. Helicobacter pylori was detected in 28% of the patients undergoing endoscopy (either in the biopsy or the urease test) and eradicated before surgery in all the patients. Helicobacter pylori was present in 9.7% of the surgical resection specimens and its presence was significantly associated with the development of postoperative complications, mostly staple line leaks (p = 0.01).ConclusionOur study confirms that Helicobacter infection is significantly associated with postoperative complications after sleeve gastrectomy. It is therefore important to detect its presence and eradicate it before surgery.     

Do Gut Hormones Contribute to Weight Loss and Glycaemic Outcomes after Bariatric Surgery?

Bariatric surgery is an effective intervention for management of obesity through treating dysregulated appetite and achieving long-term weight loss maintenance. Moreover, significant changes in glucose homeostasis are observed after bariatric surgery including, in some cases, type 2 diabetes remission from the early postoperative period and postprandial hypoglycaemia. Levels of a number of gut hormones are dramatically increased from the early period after Roux-en-Y gastric bypass and sleeve gastrectomy—the two most commonly performed bariatric procedures—and they have been suggested as important mediators of the observed changes in eating behaviour and glucose homeostasis postoperatively. In this review, we summarise the current evidence from human studies on the alterations of gut hormones after bariatric surgery and their impact on clinical outcomes postoperatively. Studies which assess the role of gut hormones after bariatric surgery on food intake, hunger, satiety and glucose homeostasis through octreotide use (a non-specific inhibitor of gut hormone secretion) as well as with exendin 9–39 (a specific glucagon-like peptide-1 receptor antagonist) are reviewed. The potential use of gut hormones as biomarkers of successful outcomes of bariatric surgery is also evaluated.     

Portomesenteric vein thrombosis following sleeve gastrectomy: Case report focusing on the role of pathogenetic factors

IntroductionSleeve gastrectomy has currently become the most commonly performed bariatric. procedure worldwide according to the last IFSO survey, overtaking gastric bypass with. a share of more than 50% of all primary bariatric-metabolic surgery. Gastric leak, intraluminal bleeding, bleeding from the staple-line and strictures are the most common complications. Portomesenteric vein thrombosis (PMVT)after sleeve gastrectomy is. another complication that has been increasingly reported in case-series in recent.years, although it remains uncommon. In this case report is described an extended portomesenteric vein thrombosis after. sleeve gastrectomy interesting splenic vein too with a favorable course and an. uneventful follow-up. We try to search in this case for pathogenetic factors involved in. this complication.Case reportA 42-year old man, with a body mass index (BMI) of 45 kg/m2, with a medical history of Obstructive Sleep Apnea Sindrome (OSAS) underwent laparoscopic sleeve gastrectomy. Early postoperative course was uneventful. Six days after discharge he complained abdominal pain and was admitted at the Emergency Department. A CT scan with intravenous contrast showed an occlusion of the portal vein, of the intrahepatic major branches and an extension to the superior mesenteric vein and the splenic vein. The patient received heparin and oral anticoagulation together with intravenous hydration and proton pump inhibitors. Considering the favourable course the patient was discharged after six days with long-term oral anticoagulation therapy. Anticoagulation with acenocumarol was continued for six months after a CT scan showed resolution of the PMVT without cavernoma. He had no recurrence of symptoms.DiscussionPorto-mesenteric thrombosis after sleeve gastrectomy is a rare complication but it has been increasingly reported over the last 10 years along with the extensive use of sleeve gastrectomy. Because PMVT is closely associated with sleeve gastrectomy in comparison with other bariatric procedures, we need to investigate what pathogenetic factors are involved in sleeve gastrectomy. Thrombophylic state, prolonged duration of surgery, high levels of pneumoperitoneum, thermal injury of the gastroepiploic vessels during greater curvature dissection, high intragastric pressure, inadequate antithrombotic prophylaxis and delayed mobilization of the patient after surgery have been reported as pathogenetic factors of portmesenteric vein thrombosis. Most of the cases presented in the literature such as our clinical case resolve with medical therapy, although portal vein thrombus extends into the superior mesenteric vein and the splenic vein.ConclusionPortomesenteric venous thrombosis is a rare but serious complication of bariatric surgery, especially associated with sleeve gastrectomy. Diagnosis is based on CT examination with intravenous contrast, and initial therapy is anticoagulation. Etiologic factors reported in the literature include a long duration of surgery, a high degree of pneumoperitoneum, high intragastric pressure after sleeve gastrectomy and thermal injury to the short gastric vessels and gastroepiploic arcade. Limited operative time, controlled values of pneumoperitoneum, careful dissection with energy device of gastric greater curvature, appropriate prophylaxis with low molecular weight heparin may be useful tools to prevent and limit this complication. Nonetheless we have to search which factors may condition the evolution of an extended PMVT as that described in this case towards resolution or to a further worsening clinical state. Early diagnosis? Correct treatment? Undiscovered patientrelated factors?     

24例胃大部切除术中损伤邻近器官的原因及对策

目的：分析胃大部切除术中邻近器官损伤的原因,提出防范措施和处理方法。方法：回顾分析24例胃大部切除术中邻近器官损伤的病例。结果：发现损伤的发生与溃疡病变严重、局部变形粘连解剖关系改变以及术操作不够规范、细致有关。结论：应重视胃大部切除术的基本要求和基本操作训练,熟悉解剖,从而避免或减少胃大部切除术中医源性损伤的发生。