Endoscopic ultrasound-guided tissue sampling induced pancreatic duct leak resolved by the placement of a pancreatic stent:A case report

BACKGROUND Pancreatic ductal leaks complicated by endoscopic ultrasonography-guided tissue sampling(EUS-TS)can manifest as acute pancreatitis.CASE SUMMARY A 63-year-old man presented with persistent abdominal pain and weight loss.Diagnosis:Laboratory findings revealed elevated carbohydrate antigen 19-9(5920 U/mL)and carcinoembryonic antigen(23.7 ng/mL)levels.Magnetic resonance imaging of the pancreas revealed an approximately 3 cm ill-defined space-occupying lesion in the inferior aspect of the head,with severe encasement of the superior mesenteric artery.Pancreatic ductal adenocarcinoma was confirmed after pathological examination of specimens obtained by EUS-TS using the fanning method.Interventions and outcomes:The following day,the patient experienced severe abdominal pain with high amylase(265 U/L)and lipase(1173 U/L)levels.Computed tomography of the abdomen revealed edematous wall thickening of the second portion of the duodenum with adjacent fluid collections and a suspicious leak from either the distal common bile duct or the main pancreatic duct in the head.Endoscopic retrograde cholangiopancreatography revealed dye leakage in the head of the main pancreatic duct.Therefore,a 5F 7 cm linear plastic stent was deployed into the pancreatic duct to divert the pancreatic juice.The patient’s abdominal pain improved immediately after pancreatic stent insertion,and amylase and lipase levels normalized within a week.Neoadjuvant chemotherapy was then initiated.CONCLUSION Using the fanning method in EUS-TS can inadvertently cause damage to the pancreatic duct and may lead to clinically significant pancreatitis.Placing a pancreatic stent may immediately resolve acute pancreatitis and shorten the waiting time for curative therapy.When using the fanning method during EUSTS,ductal structures should be excluded to prevent pancreatic ductal leakage.

Current Status and Perspectives of External Versus Internal Pancreatic Duct Drainage during the Learning Curve of Laparoscopic Pancreaticoduodenectomy

Objectives: To summarize the current status and outlook of pancreatic duct drainage in the learning curve period of laparoscopic pancreaticoduodenectomy (LPD). Methods: By searching the literature related to the efficacy analysis of internal versus external pancreatic duct drainage in pancreaticoduodenectomy (OPD) and the learning curve period of laparoscopic pancreaticoduodenectomy in recent years at home and abroad and making a review. Results: Because of the complexity of the LPD surgical procedure, the high technical requirements and the high complication rate, it is necessary for the operator and his/her team to carry out a certain number of cases to pass through the learning curve in order to have a basic mastery of the procedure. In recent years, more and more pancreatic surgeons have begun to promote and use pancreatic duct drains. However, no consensus conclusion has been reached on whether to choose internal or external drainage for pancreatic duct placement and drainage in LPD. Conclusions: Intraoperative application of pancreatic duct drainage reduces the incidence of pancreatic fistula during the learning curve of laparoscopic pancreaticoduodenectomy. However, external pancreatic duct drainage and internal pancreatic duct drainage have both advantages and disadvantages, so when choosing the drainage method, one should choose the appropriate drainage method in conjunction with one’s own conditions, so as to reduce the incidence of complications.

Integrity of the pancreatic duct-acinar system in the pathogenesis of acute pancreatitis

BACKGROUND: Acute pancreatitis is an acute inflammatory process of the pancreas that frequently involves peripancreatic tissues and at times remote organ systems. For a long time, the etiology and pathogenesis of acute pancreatitis has been intensively investigated worldwide, but the pathogenetic theories are controversial. The integrity of the pancreatic duct-acinar system might play an important role in the pathogenesis of this disease. DATA SOURCES: Web of Science and PubMed databases were searched for published studies (between January 1966 and June 2009) to identify relevant articles using the keywords 'acinar hyperstimulation', 'pathogenesis', 'acute pancreatitis', 'pancreatic duct-acinar system', and 'pancreatic duct pressure'. Most of the relevant articles were reviewed. RESULTS: From critical reading of the relevant articles, we found that the underlying mechanisms involved in the pathogenesis of acute pancreatitis are still under debate and ill-understood. On the basis of the relevant studies, we propose a hypothesis for the pathogenesis of acute pancreatitis, in which the integrity of the pancreatic duct-acinar system plays an essential role in the onset and progression of various forms of the disease. CONCLUSIONS: In our hypothesis, pancreatic duct obstruction and hyperstimulation of the exocrine pancreas are preconditions for the onset of acute pancreatitis; under the common conditions of pancreatic duct obstruction and acinar hyperstimulation, acute pancreatitis arises and develops. This may be an important common pathophysiological mechanism causing various forms of acute pancreatitis. (Hepntobiliary Pancreat Dis Int 2010; 9: 242-247)

Transpapillary incision of refractory circumscript pancreatic duct stricture using wire-guided snare forceps

Endoscopic therapy of pancreatic duct(PD)strictures using balloon dilation and pancreatic duct stent(PS) placement has been reported to improve the severity of abdominal pain in selected patients with chronic pancreatitis(CP).However,some strictures are refractory and require frequent PS exchange to control symptoms.We describe two cases of successful endoscopic PD incision for difficult PD stricture using a wireguided snare.The snare is partially opened within the strictured pancreatic duct while applying current,thus incising the duct.Although both cases were successful without complications we do not advocate that this method be used routinely because of the potential for severe complications,e.g.bleeding,ductal perforation or pancreatic parenchymal damage.In order to prevent these complications,we developed a wire-guided technique under fluoroscopic control.We think this procedure may be useful in patients with short,straight PD strictures.Although further study is required,this approach may have potential for selected patients with refractory PD strictures due to CP.

Endoscopic ultrasound-guided pancreaticogastrostomy for symptomatic pancreatic duct obstruction caused by migrated pancreatic stent

Endoscopic pancreatic stenting has been widely used in various pancreatic conditions. With the increasing use of pancreatic stents, many complications have been recognized. Especially, proximal stent migration presents a serious condition because of subsequent pancreatic duct obstruction, impaired drainage, ductal dilation, and pancreatic pain. Although endoscopic retrieval is the preferred treatment for proximally migrated pancreatic stents, it is not always successful, resulting in conversion to surgery. To date, endoscopic ultrasound-guided pancreatic duct drainage(EUS-PD) has never been reported for treatment of pancreatic duct obstruction caused by proximally migrated pancreatic stent. We herein describe a case of pancreatic duct rupture and obstruction caused by proximally migrated pancreatic stent that was successfully treated by EUS-guided pancreaticogastrostomy while keeping the former stent in situ after failed endoscopic retrograde cholangiopancreatography. We believe that this report adds to the increasing evidence of symptomatic pancreatic duct obstruction being successfully treated by EUS-PD.

Pancreatic duct stones in patients with chronic pancreatitis:surgical outcomes

BACKGROUND: Pancreatic duct stone (PDS) is a common complication of chronic pancreatitis. Surgery is a common therapeutic option for PDS. In this study we assessed the surgical procedures for PDS in patients with chronic pancreatitis at our hospital. METHOD: Between January 2004 and September 2009, medical records from 35 patients diagnosed with PDS associated with chronic pancreatitis were retrospectively reviewed and the patients were followed up for up to 67 months. RESULTS: The 35 patients underwent ultrasonography, computed tomography, or both, with an overall accuracy rate of 85.7%. Of these patients, 31 underwent the modified Puestow procedure, 2 underwent the Whipple procedure, 1 underwent simple stone removal by duct incision, and 1 underwent pancreatic abscess drainage. Of the 35 patients, 28 were followed up for 4-67 months. There was no postoperative death before discharge or during follow-up. After the modified Puestow procedure, abdominal pain was reduced in patients with complete or incomplete stone clearance (P>0.05). Steatorrhea and diabetes mellitus developed in several patients during a long-term follow-up. CONCLUSIONS: Surgery, especially the modified Puestow procedure, is effective and safe for patients with PDS associated with chronic pancreatitis. Decompression of intraductal pressure rather than complete clearance of all stones predicts postoperative outcome.

Retrospective analysis of 88 patients with pancreatic duct stone

BACKGROUND: Pancreatic duct stone is a rare disease, but there appears to be a rising trend in its incidence in recent years. Its pathogenesis remains unknown. The causes, diagnosis and treatment of pancreatic duct stone are reviewed through a retrospective analysis of the cases treated in our hospital. METHODS: The medical records of 88 patients with pancreatic duct stone treated in West China Hospital, Sichuan University from January 1, 1998 to November 30, 2004 were analyzed retrospectively in terms of clinical characteristics, diagnosis and treatment. RESULTS: Epigastric pain was the most common symptom in the 88 patients with an average age of 45.44 +/- 6.72 years. Various other symptoms were also observed. Eighty-one patients were subjected to B-ultrasonography, 51 to CT, and 47 to magnetic resonance cholangiopancreatography (MRCP). Fifty-six patients (63.64%) were operated on, 25 (28.41%) were treated with Chinese and Western medicine, and 7 (7.95%) abandoned treatment. Chronic pancreatitis was pathologically confirmed in all patients undergoing operation. CONCLUSIONS: B-ultrasonography is the first choice to check for pancreatic duct stone, while MRCP proves instructively useful for the diagnosis and treatment. Chronic pancreatitis is the most important cause of pancreatic duct stone, but whether there is not a direct correlation between stone formation and alcohol abuse needs further study in China. Surgery is the most curative method for pancreatic duct stone patients with severe symptoms or suspected pancreatic carcinoma, while individual treatment is emphasized, and microtraumatic surgery may be a developing option for treating pancreatic stone.

Clinical significance of main pancreatic duct dilation on computed tomography: Single and double duct dilation

AIM: To study the patients with main pancreatic duct dilation on computed tomography (CT) and thereby to provide the predictive criteria to identify patients at high risk of significant diseases, such as pancreatic cancer, and to avoid unnecessary work up for patients at low risk of such diseases. METHODS: Patients with dilation of the main pancreatic duct on CT at Emory University Hospital in 2002 were identified by computer search. Clinical course and ultimate diagnosis were obtained in all the identified patients by abstraction of their computer database records. RESULTS: Seventy-seven patients were identified in this study. Chronic pancreatitis and pancreatic cancer were the most common causes of the main pancreatic duct dilation on CT. Although the majority of patients with isolated dilation of the main pancreatic duct (single duct dilation) had chronic pancreatitis, one-third of patients with single duct dilation but without chronic pancreatitis had pancreatic malignancies, whereas most of patients with concomitant biliary duct dilation (double duct dilation) had pancreatic cancer. CONCLUSION: Patients with pancreatic double duct dilation need extensive work up and careful followup since a majority of these patients are ultimately diagnosed with pancreatic cancer. Patients with single duct dilation, especially such patients without any evidence of chronic pancreatitis, also need careful follow-up since the possibility of pancreatic malignancy, including adenocarcinoma and intraductal papillary mucinous tumors, is still high.

Internal compared with external drainage of pancreatic duct during pancreaticoduodenectomy: a retrospective study

Objective： To compare internal with external drainage of the pancreatic duct during pancreaticoduodenectomy with regard to the incidence of postoperative pancreatic fistula （POPF） and other complications. Methods： We retrospectively analyzed 316 patients who underwent pancreaticoduodenectomy with a placed drainage tube （external, n=128; internal, n=188） in the pancreatic duct from 1 January 1999 to 31 December 2011 in Tianjin Third Central Hospital of China. The incidence of POPF and some other complications were compared. Results： There was no difference in the incidence rates of POPF between those given an internal or external drainage tube （P=0.788）, but POPF was more severe in the former （P=0.014）. Intraperitoneal bleeding rate was also higher in the patients with internal drainage （P=0.040）, but operative time and postoperative hospitalization were longer in those with external drainage （P=0.002 and P=0.007, respectively）. There was no difference between the groups with regard to the incidence rates of gastrointestinal bleeding, delayed gastric emptying, pulmonary infection, or incision infection and in-hospital mortality. Conclusions： External drainage of the pancreatic duct during pancreaticoduodenectomy can decrease the severity of POPF, but operative time and postoperative hospitalization will be extended.

Pancreatic duct guidewire placement for biliary cannulation in a single-session therapeutic ERCP

AIM: To investigate the technical success and clinical complication rate of a cannulated pancreatic duct with guidewire for biliary access. METHODS: During a five-year study period, a total of 2843 patients were included in this retrospective analysis. Initial biliary cannulation method consisted of single-guidewire technique (SGT) for up to 5 attempts, followed by double-guidewire technique (DGT) when repeated unintentional pancreatic duct cannulation had taken place. Pre-cut papillotomy technique was reserved for when DGT had failed or no pancreatic duct cannulation had been previously achieved. Main outcome measurements were defined as biliary cannu-lation success and post-endoscopic retrograde cholangiopancreatography (ERCP) complication rate. RESULTS: SGT (92.3% success rate) was characterized by statistically significant enhanced patient outcome compared to either the DGT (43.8%, P < 0.001), pre-cut failed DGT (73%, P < 0.001) or pre-cut as first step method (80.6%, P = 0.002). Pre-cut as first step method offered a statistically significantly more favorable outcome compared to the DGT (P < 0.001). The incidence of post-ERCP pancreatitis did not differ in a statistically significant manner between either method (SGT: 5.3%, DGT: 6.1%, Pre-cut failed DGT: 7.9%, Pre-cut as first step: 7.5%) or with patients' gender. CONCLUSION: Although DGT success rate proved not to be superior to SGT or pre-cut papillotomy, it is considered highly satisfactory in terms of safety in order to avoid the risk of a pre-cut when biliary therapy is necessary in difficult-to-cannulate cases.

Endoscopic pancreatic duct stent placement for inflammatory pancreatic diseases

The role of endoscopic therapy in the management of pancreatic diseases is continuously evolving; at present most pathological conditions of the pancreas are successfully treated by endoscopic retrograde cholangio- pancreatography （ERCP） or endoscopic ultrasound （EUS）, or both. Endoscopic placement of stents has played and still plays a major role in the treatment of chronic pancreatitis, pseudocysts, pancreas divisum, main pancreatic duct injuries, pancreatic fistulae, complications of acute pancreatitis, recurrent idiopathic pancreatitis, and in the prevention of post-ERCP pancreatitis. These stents are currently routinely placed to reduce intraductal hypertension, bypass obstructing stones, restore lumen patency in cases with dominant, symptomatic strictures, seal main pancreatic duct disruption, drain pseudocysts or fluid collections, treat symptomatic major or minor papilla sphincter stenosis, and prevent procedure-induced acute pancreatitis. The present review aims at updating and discussing techniques, indications, and results of endoscopic pancreatic duct stent placement in acute and chronic inflammatory diseases of the pancreas.

Magnetic resonance cholangiopancreatography for the detection of pancreatic duct stones in patients with chronic pancreatitis

AIM:To assess the role of magnetic resonance cholangiopancreatography(MRCP) in detection of pancreatic duct stones(PDS) in patients with chronic pancreatitis(CP).METHODS:Clinical data of 78 CP patients who were treated at the First Affi liated Hospital of Xi'an Jiaotong University(China) between January 2004 and July 2008 were retrospectively analyzed.A predictive model of pancreatic duct stones was established through logistic regression and its effectiveness was verifi ed.Among these patients, MRCP was performed in 60 patients who served as a control group, while 44 patients with a higher predictive value than the entry threshold of the predictive model served as an experimental group.RESULTS:The positive rate of PDS in the 78 patients with CP was 19.2%(15/78).The predictive entry threshold of the predictive model was 5%(P < 0.05).The possibility of existence of PDS could be predicted according to the following 4 indexes:gastrointestinal symptoms, intermittent abdominal pain, diabetes mellitus(DM)/impaired glucose tolerance(IGT) and positive B-mode ultrasound results.The incidence of PDS in the experimental group was higher than that in the control group(P < 0.05).CONCLUSION:MRCP is strongly suggested for the detection of PDS in patients with gastrointestinal symptoms, intermittent abdominal pain, DM/IGT and positive B-mode ultrasound results.

Detection of K-ras gene mutation at codon 12 by pancreatic duct brushing for pancreatic cancer

OBJECTIVE: To assess the diagnostic value of endoscopic pancreatic duct brushing in detecting mutation of the K-ras gene at codon 12 in cytologic specimens from patients with pancreatic cancer. METHODS: Thirty-five patients treated at Changhai Hospital, Shanghai between 1999 and 2001 were enrolled. Their cells obtained by pancreatic duct brushing during endoscopic retrograde tholangiopancreatography (ERCP) were suspended with phosphate buffer solution (PBS). DNA of the cells was extracted and mutation of the K-ras gene at codon 12 detected by means of PCR-SSCP. RESULTS: The K-ras gene mutation rate of pancreatic cancer was 70%, which was higher than that of chronic pancreatitis (14%, P<0.05). K-ras gene mutation was not found in patients with pancreatic cystorcarcinoma and duodenum carcinoma. As to the location of pancreatic cancer, no significant difference was observed between the head, the body and tail. The sensitivity, specificity, accuracy of pancreatic duct brushing in detecting pancreatic cancer was 70%, 94%, and 83%, respectively. CONCLUSION: K-ras analysis of pancreatic brushing samples is helpful in the diagnosis of patients with early pancreatic cancer.

Pancreatic duct disruption and nonoperative management: the SEALANTS approach

Pancreatic-duct disruption (PDD) can be difficult to manage, with diverse etiologies and sequelae in a heterogeneous population. Common etiologies include pancreatitis, iatrogenic injury, and trauma. Sequelae of PDD include pseudocyst, pancreatic ascites,

Percutaneous transluminal angioplasty balloons for endoscopic ultrasound-guided pancreatic duct interventions

BACKGROUND Endoscopic ultrasound(EUS)-guided main pancreatic duct(PD)access may be used when conventional endoscopic retrograde cholangiopancreatography(ERCP)techniques fail.The use of a percutaneous transluminal angioplasty balloon(PTAB),originally developed for vascular interventions,can be used to facilitate transmural(e.g.,transgastric)PD access and to dilate high-grade pancreatic strictures.AIM To describe the technique,efficacy,and safety of PTABs for EUS-guided PD interventions.METHODS Patients who underwent EUS with use of a PTAB from March 2011 to August 2021 were retrospectively identified from a tertiary care medical center supply database.PTABs included 3-4 French angioplasty catheters with 3-4 mm balloons designed to use over a 0.018-inch guidewire.The primary outcome was technical success.Secondary outcomes included incidence of adverse events(AEs)and need for early reintervention.RESULTS A total of 23 patients were identified(48%female,mean age 55.8 years).Chronic pancreatitis was the underlying etiology in 13(56.5%)patients,surgically altered anatomy(SAA)with stricture in 7(30.4%),and SAA with post-operative leak in 3(13.0%).Technical success was achieved in 20(87%)cases.Overall AE rate was 26%(n=6).All AEs were mild and included 1 pancreatic duct leak,2 cases of post-procedure pancreatitis,and 3 admissions for post-procedural pain.No patients required early re-intervention.CONCLUSION EUS-guided use of PTABs for PD access and/or stricture management is feasible with an acceptable safety profile and can be considered in patients when conventional ERCP cannulation fails.

Comparison of postoperative complications between internal and external pancreatic duct stenting during pancreaticoduodenectomy: a meta-analysis

Background：Two types of pancreatic duct stents are used to improve postoperative outcomes of pancreatic anastomosis.The aim of this meta-analysis was to evaluate and compare the postoperative outcomes of patients with internal or external stenting during pancreaticoduodenectomy（PD）.Methods：We searched Pub Med,EMBASE,the Cochrane Library and Web of Science databases until the end of December,2014.Studies comparing outcomes of external vs.internal stent placement in PD were eligible for inclusion.Included literature was extracted and assessed by two independent reviewers.Results：Seven articles were identified for inclusion：three randomized controlled trials（RCTs）and four observational clinical studies（OCS）.The meta-analyses revealed that use of external stents had advantage on reducing the incidences of pancreatic fistula（PF）in total[odds ratio（OR）=0.69;95%confidence interval（CI）,0.48-0.99;P=0.04],PF in soft pancreas（OR=0.30;95%CI,0.16-0.56;P=0.0002）and delayed gastric emptying（DGE）（OR=0.58;95%CI,0.38-0.89;P=0.01）compared with internal stents.There were no significant differences in other postoperative outcomes between two stenting methods,including postoperative morbidity（OR=0.93;95%CI,0.39-2.23;P=0.88）,overall mortality（OR=0.70;95%CI,0.22-2.25;P=0.55）,and intra-abdominal collections（OR=0.67;95%CI,0.26-1.71;P=0.40）.Conclusions：Based upon this meta-analysis,the use of external pancreatic stents might have potential benefit in reducing the incidence of PF and DGE.Due to the limited number of original studies,more RCTs are needed to further support our result and clarify the issue.

Small serotonin-positive pancreatic endocrine tumors caused obstruction of the main pancreatic duct

We report 2 cases of pancreatic endocrine tumors that caused obstruction of the main pancreatic duct(MPD).A 49-year-old asymptomatic man was referred to our institution because dilation of the MPD was revealed by abdominal ultrasonography(US).No tumor was detected by endoscopic ultrasonography,computed tomography(CT),and magnetic resonance imaging(MRI).The diameter of the MPD was > 20 mm at the body,and no dilation was noted at the head.Although malignancy was not confirmed through cytology or imaging,pancreatic cancer was strongly suspected.Pancreaticoduo-denectomy was performed.Pathological and immunohistochemical examination revealed a 5 mm × 3 mm serotonin-positive endocrine tumor.Fibrosis was present around the MPD and seemed to cause stricture.A 32-year-old asymptomatic man had elevated serum amylase,and US demonstrated dilation of the MPD.No tumor was detected by CT and MRI.Pancreatic cancer was suspected due to stricture and dilation of the MPD.Pancreatectomy of middle part of pancreas was performed.Pathological and immunohistochemical examination revealed a serotonin-positive endocrine tumor sized 5 mm × 4 mm.We report 2 cases of serotonin-positive pancreatic endocrine tumors that caused stricture of the MPD in spite of the small size of the tumor.

Induction of pancreatic duct cells of neonatal rats into insulin-producing cells with fetal bovine serum: A natural protocol and its use for patch clamp experiments

AIM： To induce the pancreatic duct cells into endocrine cells with a new natural protocol for electrophysiological study. METHODS： The pancreatic duct cells of neonatal rats were isolated, cultured and induced into endocrine ceils with 15% fetal bovine serum for a period of 20 d. During this period, insulin secretion, MTT value, and morphological change of neonatal and adult pancreatic islet cells were comparatively investigated. Pancreatic β-cells were identified by morphological and electrophysiological characteristics, while ATP sensitive potassium channels （KATP）, voltage-dependent potassium channels （Kv）, and voltage-dependent calcium channels （KcA） in β-cells were identified by patch clamp technique. RESULTS： After incubation with fetal bovine serum, the neonatal duct cells budded out, changed from duct-like cells into islet clusters. In the first 4 d, MTT value and insulin secretion increased slowly （MTT value from 0.024 ±0.003 to 3.028±0.003, insulin secretion from 2.6±0.6 to 3.1±0.8 mIU/L）. Then MTT value and insulin secretion increased quickly from d 5 to d 10 （MTT value from 0.028 ±0.003 to 0.052±0.008, insulin secretion from 3.1±0.8 to 18.3±2.6 mIU/L）, then reached high plateau （MTT value 〉0.052±0.008, insulin secretion 〉18.3±2.6 mIU/L）. In contrast, for the isolated adult pancreatic islet cells, both insulin release and MTT value were stable in the first 4 d （MTT value from 0.029±0.01 to 0.031±0.011, insulin secretion from 13.9±3.1 to 14.3±3.3 mIU/L）, but afterwards they reduced gradually （MTT value 〈0.031 ±0.011, insulin secretion 〈8.2±1.5 mIU/L）, and the pancreatic islet cells became dispersed, broken or atrophied correspondingly. The differentiated neonatal cells were identified as pancreatic islet cells by dithizone staining method, and pancreatic β-cells were further identified by both morphological features and electrophysiological characteristics, i.e. the existence of recording currents from KATP, Kv, and KCA. CONCLUSION： Islet cells differentiated from neonatal pancreatic duct cells with the new natural protocol are more advantageous in performing patch clamp study over the isolated adult pancreatic islet cells.

Characterization of H^+ and HCO_3^- transporters in CFPAC-1 human pancreatic duct cells

AIM： To characterize H^＋ and HCO3^- transporters in polarized CFPAC-1 human pancreatic duct cells, which were derived from a cystic fibrosis patient with the AF508 CFTR mutation. METHODS： CFPAC-1 cells were seeded at high density onto permeable supports and grown to confluence. The cells were loaded with the pH-sensitive fluorescent dye BCECF, and mounted into a perfusion chamber, which allowed the simultaneous perfusion of the basolateral and apical membranes. Transmembrane base flux was calculated from the changes in intracellular pH and the buffering capacity of the cells. RESULTS： Our results showed differential permeability to HCO3^＋/CO2 at the apical and basolateral membranes of CFPAC-1 cells. Na^＋/HCO3^- co-transporters （NBCs） and Cl^-/HCO3^- exchangers （AEs） were present on the basolateral membrane, and Na＋/H＋ exchangers （NHEs） on both the apical and basolateral membranes of the cells. Basolateral HCO3 uptake was sensitive to variations of extracellular K^＋ concentration, the membrane permeable carbonic anhydrase （CA） inhibitors acetazolamide （100 μmol/L） and ethoxyzolamide （100 μmol/L）, and was partially inhibited by H2-DIDS （600 μmol/L）. The membrane-impermeable CA inhibitor 1-N-（4-sulfamoylphenylethyl）-2,4,6-trimethylpyridine perchlorate did not have any effect on HCO3^- uptake.The basolateral AE had a much higher activity than that in the apical membrane, whereas there was no such difference with the NHE under resting conditions. Also, 10 μmol/L forskolin did not significantly influence Cl^-/HCO3^- exchange on the apical and basolateral membranes. The administration of 250 μmol/L H2-DIDS significantly inhibited the basolateral AE. Amiloride （300 μmol/L） completely inhibited NHEs on both membranes of the cells. RT-PCR revealed the expression of pNBC1, AE2, and NHE1 mRNA. CONCLUSION： These data suggest that apart from the lack of CFTR and apical Cl^-/HCO3^- exchanger activity, CFPAC-1 cells express similar H^＋ and HCO3^- transporters to those observed in native animal tissue.

Air in the main pancreatic duct:A case of innocent air

Air in the main pancreatic duct has been reported only rarely and might be associated with either a spontane- ous or a surgically induced alteration of the anatomy of the biliary tract. We report a case of ＂innocent＂ air found incidentally in the main pancreatic duct. To our knowledge, this is only the third such case reported. A 54-year-old woman presented with hemoptysis that had lasted for 3 d. She underwent a chest computed tomography scan, which revealed not only focal bron- chiectasis in the left lower lobe, but also air in the main pancreatic duct and dilatation of the common bile duct. She was managed conservatively for the hemop- blsis and no further problems developed. She had no specific gastrointestinal symptoms and had no history of surgery or medication. Her laboratory parameters were normal. Magnetic resonance cholangiopancrea- tography also demonstrated air in the main pancreatic duct and a dilated common bile duct （CBD）. Duode- noscopy revealed separate biliary and pancreatic ori-rices with patulous openings and some air bubbles ap- pearing in the pancreatic orifice. Endoscopic retrograde cholangiopancreatography （ERCP） showed the dilated CBD and pancreatic duct with some air bubbles, but no other abnormal lesions. She was discharged with no further problems. Most patients with air in the main pancreatic duct have had a pancreatobiliary disease, or a history of pancreatobiliary disease, pancreatobiliary surgery or sphincterotomy. If the air is innocent, as in our case, ERCP should be performed to evaluate any altered sphincteric function or anatomy such as patu- Ious openings.