A novel self-assembling peptide hemostatic gel as rescue therapy for fistula bleeding after endoscopic ultrasound-guided hepaticogastrostomy

The novel synthetic self-assembling peptide PuraStat has been approved for hemostasis in endoscopic procedures. Nakahara and colleagues describe their application of PuraStat for hemostasis of refractory fistula bleeding after endoscopic ultrasound-guided hepaticogastrostomy. The effective and technically easy procedure is a useful option when hemostasis cannot be achieved by other means.

Suprapapillary placement of plastic versus metal stents for malignant biliary hilar obstructions: a multicenter, randomized trial

BACKGROUND AND AIMS

The efficacy of the suprapapillary placement of inside plastic stents (iPSs) for unresectable malignant hilar biliary obstructions (MHOs) is unknown compared with that of uncovered inside metal stents (iMSs). This randomized controlled trial was designed to evaluate the outcomes of endoscopic placement of these stents for unresectable MHOs.

METHODS

This open-label, randomized study was conducted at 12 Japanese institutions. The enrolled patients with unresectable MHOs were allocated to iPS and iMS groups. The primary outcome was defined as the time to recurrent biliary obstruction in patients for whom the intervention was both technically and clinically successful.

RESULTS

Among 87 enrollments, 38 patients in the iPS group and 46 patients in the iMS group were analyzed. Technical success rates were 100% (38 of 38) and 96.6% (44 of 46), respectively (P = 1.00). After transferring 1 unsuccessful iMS-group patient to the iPS group (since iPSs were deployed), the clinical success rates were 90.0% (35 of 39) for the iPS group and 88.9% (40 of 45) for the iMS group from a per-protocol analysis (P = 1.00). Among the patients with clinical success, the median times to recurrent biliary obstruction were 250 (95% confidence interval, 85-415) and 361 (95% confidence interval, 107-615) days (log-rank test, P = .34). No differences were detected in rates of adverse events.

CONCLUSIONS

This Phase II randomized trial did not show any statistically significant difference in stent patency between suprapapillary plastic versus metal stents. Considering the potential advantages of plastic stents for malignant hilar obstruction, these findings suggest that suprapapillary plastic stents could be a viable alternative to metal stents for this condition.

Clinical outcomes and predictors of technical failure of endoscopic transpapillary gallbladder drainage in acute cholecystitis

BACKGROUND AND AIMS

Endoscopic transpapillary gallbladder drainage (ETGBD) has been performed as an alternative therapy against cholecystectomy in patients with acute cholecystitis. To date, few studies have reported the safety, efficacy, and factors affecting ETGBD. We evaluated the clinical outcomes and predictors of technical failure of ETGBD.

METHODS

Patients with acute cholecystitis who underwent ETGBD were retrospectively reviewed, and consecutive patients were included in the study. The technical success rate, clinical success rate, adverse events, and the predictors associated with the technical failure of ETGBD were investigated.

RESULTS

A total of 242 patients were enrolled in the study. The technical success rate of ETGBD and clinical success rate of technically successful ETGBD cases were 87% and 93%, respectively. We experienced cystic duct injury in 24 patients as an ETGBD-related adverse event, and pancreatitis in 12 patients as an endoscopic retrograde cholangiopancreatography-related adverse event. Multivariate analysis indicated that cystic duct injury was the independent predictor associated with the technical failure of ETGBD (odds ratio, 11; 95% confidence interval, 3.9-29; p < 0.001).

CONCLUSIONS

ETGBD was a safe and effective treatment method for acute cholecystitis with acceptable adverse events. There was no predictor based on the information from patient characteristics; however, cystic duct injury was associated with the technical failure of ETGBD.

Long-term outcomes of endoscopic transpapillary gallbladder drainage using a novel spiral plastic stent in acute calculus cholecystitis

BACKGROUND

Endoscopic transpapillary gallbladder stenting (EGBS) is considered for patients with contraindications to early surgery for acute calculus cholecystitis. However, evidence regarding the long-term outcomes of EGBS is insufficient to date. The aim of the study was to evaluate the feasibility of EGBS as a bridge to or alternative to surgery when there are contraindications.

METHODS

We reviewed the cases of patients who underwent EGBS using a novel spiral-shaped plastic stent for acute calculus cholecystitis between January 2011 and December 2019. We retrospectively evaluated the long-term outcomes of EGBS using a novel spiral-shaped plastic stent.

RESULTS

Forty-nine patients were included. The clinical success rate of EGBS was 97%. After EGBS, 25 patients (surgery group) underwent elective cholecystectomy and 24 patients did not (follow-up group). In the surgery group, the median period from EGBS to surgery was 93 days. There was a single late adverse event with cholecystitis recurrence. In the follow-up group, the median follow-up period was 236 days. Late adverse events were observed in eight patients, including recurrence of cholecystitis (four patients), duodenal penetration by the distal stent end (two patients), and distal stent migration (two patient). In the follow-up group, the time to recurrence of biliary obstruction was 527 days.

CONCLUSIONS

EGBS with a novel spiral-shaped plastic stent is safe and effective for long-term acute calculus cholecystitis. There is a possibility of EGBS to be a bridge to surgery and a surgical alternative for acute calculus cholecystitis in patients with contraindications to early cholecystectomy.

Incidence and management of cystic duct perforation during endoscopic transpapillary gallbladder drainage for acute cholecystitis

BACKGROUND AND AIM

Evidence regarding the incidence and clinical outcome of cystic duct perforation (CDP) during endoscopic transpapillary gallbladder drainage (ETGBD) is inadequate. The present study aimed to evaluate the incidence and management of CDP during ETGBD.

METHODS

Between March 2011 and December 2019, 249 patients underwent initial ETGBD for acute cholecystitis. The incidence of CDP was retrospectively examined and the outcomes between the CDP and non-CDP groups were compared.

RESULTS

CDP during ETGBD occurred in 23 (9.2%) of 249 patients (caused by guidewire in 15 and cannula in 8). ETGBD was successful in 10 patients following CDP. In 13 patients who failed ETGBD, 11 underwent bile duct drainage during the same session; nine patients underwent gallbladder decompression by other methods, such as percutaneous drainage. Clinical resolution for acute cholecystitis was achieved in 20 patients, and no bile peritonitis was noted. ETGBD technical success rates (45.3% vs. 91.2%, p < 0.001), ETGBD procedure times (66.5 vs. 54.8 min, p = 0.041), and hospitalization periods (24.5 vs. 18.7 days, p = 0.028) were significantly inferior in the CDP group (n = 23) compared with the non-CDP group (n = 216). There were no differences in clinical success and adverse events other than CDP between both groups.

CONCLUSIONS

Cystic duct perforation reduced the ETGBD technical success rate. However, even in patients with cystic duct perforation, an improvement of acute cholecystitis was achieved by subsequent successful ETGBD or additional procedures, such as percutaneous drainage.

Clinical Outcomes of Early Endoscopic Transpapillary Biliary Drainage for Acute Cholangitis Associated with Disseminated Intravascular Coagulation

Acute cholangitis (AC) is often associated with disseminated intravascular coagulation (DIC), and endoscopic transpapillary biliary drainage (EBD) under endoscopic retrograde cholangiopancreatography (ERCP) is a treatment of choice. However, no evidence exists on the outcomes of EBD for AC associated with DIC. Therefore, we retrospectively evaluated the treatment outcomes of early EBD and compared endoscopic biliary stenting (EBS) and endoscopic nasobiliary drainage (ENBD). We included 62 patients who received early EBD (EBS: 30, ENBD: 32) for AC, associated with DIC. The rates of clinical success for AC and DIC resolution at 7 days after EBD were 90.3% and 88.7%, respectively. Mean hospitalization period was 31.7 days, and in-hospital mortality rate was 4.8%. ERCP-related adverse events developed in 3.2% of patients (bleeding in two patients). Comparison between EBS and ENBD groups showed that the ENBD group included patients with more severe cholangitis, and acute physiology and chronic health evaluation II score, systemic inflammatory response syndrome score, and serum bilirubin level were significantly higher in this group. However, no significant difference was observed in clinical outcomes between the two groups; both EBS and ENBD were effective. In conclusion, early EBD is effective and safe for patients with AC associated with DIC.

Efficacy of endoscopic large balloon dilation extended for 2 minutes in bile duct stone removal: A multicenter retrospective study

BACKGROUND/PURPOSE

There is no evidence regarding the optimal balloon dilation time during endoscopic papillary large balloon dilation (EPLBD). The study aim was to evaluate the efficacy of 2-minute extended balloon dilation for EPLBD.

METHODS

Two hundred and five patients who underwent EPLBD during endoscopic retrograde cholangiopancreatography (ERCP) for bile duct stones at three tertiary centers were included in the analysis. Clinical outcomes and the adverse events were compared between the 0-minute group (n = 94, balloon deflated immediately after waist disappearance) and the 2-minute group (n = 111, balloon dilation maintained for 2 minutes after waist disappearance). The risk factors of post-ERCP pancreatitis (PEP) after EPLBD were assessed.

RESULTS

There were no significant differences in the stone removal rates and hospitalization periods between the two groups. However, the total ERCP procedure time was significantly shorter in the 2-minute group (40.6 vs 48.9 min, P = .03). The incidence of PEP was 7.4% in the 0-minute group and significantly lower at 0.9% in the 2-minute group (P = .04). Multivariate analysis identified without 2-minute extended EPLBD as a significant risk factor of PEP (OR: 9.9, P = .045).

CONCLUSIONS

Extension of EPLBD for 2 minutes helped prevent PEP and shortened the procedure time.

Pancreatic duct guidewire placement for biliary cannulation as a risk factor for stone residue after endoscopic transpapillary stone removal

Background

Recent improvements in stone extraction implements and apparatus have lessened the complexity of the endoscopic bile duct stone treatment. However, despite confirmation of complete removal, cases of residual stones have been reported, which can result in recurrent biliary symptoms, cholangitis, and pancreatitis and considerably increase cost given the need for repeat imaging and/or procedures. To date, risk factors for residual bile duct stones following endoscopic retrograde cholangiopancreatography (ERCP) extraction have not been thoroughly evaluated. This study retrospectively investigated the incidence and risk factors of residual bile duct stones following extraction via ERCP.

Methods

We retrospectively reviewed all ERCP cases that underwent endoscopic bile duct stone extraction between April 2014 and March 2019. A total of 505 patients were enrolled and evaluated for the incidence and risk factors of residual bile duct stones after ERCP.

Results

The rate of residual stones was 4.8% (24/505). Residual stones were detected by computed tomography (12/24) or magnetic resonance cholangiopancreatography (12/24). In univariate analyses, a large number of stones (P = 0.01), long procedure time (P = 0.005), and performance of the pancreatic duct guidewire placement method (P-GW) for selective bile duct cannulation (P = 0.01) were the factors involved in residual stones. In multiple logistic regression analysis, performing P-GW was retained as the only independent factor of residual stones (adjusted odds ratio, 3.44; 95% CI, 1.19–9.88; P = 0.02).

Conclusions

When removing bile duct stones with a pancreatic guidewire in place, paying attention to residual stones is necessary.

Use of washing cytology from removed self-expandable metal stents for biliary strictures: a novel cytology method

Removability is one of the important features of biliary covered self-expandable metal stents (CSEMS). In this study, we evaluated the diagnostic ability of washing cytology of removed CSEMS. For 14 removed CSEMS that had been placed for the biliary strictures (12 malignant, 2 benign), the surface of CSEMS was washed with saline, and pathological examination of the washing liquid as cytology (CSEMS washing cytology) was performed. The specimen sampling rates and sensitivity for malignancy of CSEMS washing cytology were 92.9 % and 41.7 %, respectively. Sensitivity according to the primary disease was 60.0 % for bile duct cancer and 20 % for pancreatic cancer. Sensitivities based on the methods of stent removal were 16.7 % and 66.7 % for removal through the channel of the scope and with the scope, respectively. Therefore, it is possible that sensitivity of CSEMS washing cytology is higher in bile duct cancer and for removal with the scope. In conclusion, CSEMS washing cytology may have potential as a pathological diagnostic method.

Endoscopic transpapillary gallbladder stenting using a newly designed plastic stent for acute cholecystitis

Background and study aims Biliary plastic stents are generally substituted for gallbladder stents in endoscopic transpapillary gallbladder stenting (EGBS), there is no sufficient evidence about what type of plastic stent is suitable. We examined outcomes of EGBS using standard biliary stents and a novel stent for acute cholecystitis and evaluated the efficacy of the novel stent.

Patients and methods Seventy patients with acute cholecystitis in whom EGBS was performed were evaluated retrospectively. We performed EGBS in 23 patients using the novel stent (novel stent group) and 47 patients using standard biliary stents (pigtail: 35, straight: 12) (control group). In the two groups, we examined outcomes of EGBS.

Results There were no significant differences in patient backgrounds or rates of technical success, clinical success, or early adverse events (AE) between the novel stent group and the control groups. However, rates of late AEs were 4.3 % in the novel stent group (liver abscess: 1) and 40.4 % in the control group (stent migration: 15, recurrence of cholecystitis: 4), indicating a significantly higher rate in the control group (P = 0.004). The rate of stent migration was significantly higher in the control group (P = 0.006). Multivariate analysis identified a straight type stent as the risk factor for stent migration (odds ratio: 8.81, 95 % confidence interval: 1.66 – 46.83).

Conclusions The novel stent had significantly lower rates of late AEs and stent migration. Thus, for long-term stent placement, the novel stent was more effective than traditional biliary stents.

Efficacy of Combined Thrombomodulin and Antithrombin in Anticoagulant Therapy for Acute Cholangitis-induced Disseminated Intravascular Coagulation

Objective The efficacy and safety of concomitant use of antithrombin (AT) with recombinant human soluble thrombomodulin (rTM) for acute cholangitis-induced disseminated intravascular coagulation (AC-induced DIC) remains unclear. This study was conducted to investigate the efficacy of AT combined with rTM as anticoagulant therapy for AC-induced DIC. Methods One hundred patients with AC-induced DIC received anticoagulant therapy using rTM from April 2010 to December 2017. Of the 83 patients treated with rTM immediately after the diagnosis of DIC, excluding those who had not undergone biliary drainage or who had malignancies or a serum AT III level >70%, 56 patients were studied. Outcomes and adverse events (AEs) were retrospectively compared between the 16 patients treated with rTM alone (rTM group) and the 40 patients treated with rTM and AT (rTM+AT group). Results Patients' background characteristics did not differ markedly, except for a significantly higher serum D-dimer level in the rTM group than in the rTM+AT group (p=0.038). The DIC resolution rates on day 9 were 100% and 95.1% in the rTM and rTM+AT groups, respectively (p=0.909). The mean DIC scores were significantly lower in the rTM group than in the rTM+AT group on days 3 (p=0.012), 5 (p<0.001), 7 (p=0.033), and 9 (p=0.007). The incidence of AEs was 6.3% and 10.0% (p=0.941), and the in-hospital mortality rates was 0% and 5.0% (p=0.909) in the rTM and rTM+AT groups, respectively. Conclusion The concomitant use of AT with anticoagulant therapy using rTM for AC-induced DIC may not help improve the treatment outcome.

Crowned dens syndrome developed after an endoscopic retrograde cholangiopancreatography procedure

We present a unique case of crowned dens syndrome (CDS) that developed after endoscopic retrograde cholangiopancreatography (ERCP) in a patient who presented with fever and neck pain. Administration of non-steroidal anti-inflammatory drugs was extremely effective for relieving fever and neck pain, and in the improvement of inflammatory markers. To the best of our knowledge, this is the first case report of CDS caused by an ERCP procedure. In a patient with fever and neck pain after an ERCP procedure, CDS should be considered in the differential diagnosis.

A case of Ménétrier's disease seemingly caused by hilar cholangiocarcinoma

A 54-year-old man presented to our department with abdominal discomfort and anorexia and was diagnosed as having Ménétrier's disease (MD) with hilar cholangiocarcinoma. Based on his clinical examination, there was no evidence of Helicobacter pylori or cytomegalovirus (CMV) infection. Although we administered proton pump inhibitor and high-calorie enteral nutrition, hypoproteinemia did not improve, and the refractory protein-losing enteropathy persisted. However, interestingly, MD improved immediately after resection of the hilar cholangiocarcinoma. Generally, the etiology of MD is unknown, but H. pylori and CMV infections have been implicated. To our knowledge, there has been no previous report indicating that a malignant tumor could be involved in the etiology of MD. Thus, we report an extremely rare case of MD which is seemingly caused by malignancy.

A Case of Ampullary Adenoma that Developed to Cancer 7 Years After Initial Diagnosis

Patient: Male, 81

Final Diagnosis: Ampullary cancer

Symptoms: Jaundice

Medication: —

Clinical Procedure: Endoscopy

Specialty: Gastroenterology and Hepatology

Enteral metallic stenting by balloon enteroscopy for obstruction of surgically reconstructed intestine

We present three cases of self-expandable metallic stent (SEMS) placement using a balloon enteroscope (BE) and its overtube (OT) for malignant obstruction of surgically reconstructed intestine. A BE is effective for the insertion of an endoscope into the deep bowel. However, SEMS placement is impossible through the working channel, because the working channel of BE is too small and too long for the stent device. Therefore, we used a technique in which the BE is inserted as far as the stenotic area; thereafter, the BE is removed, leaving only the OT, and then the stent is placed by inserting the stent device through the OT. In the present three cases, a modification of this technique resulted in the successful placement of the SEMS for obstruction of surgically reconstructed intestine, and the procedures were performed without serious complications. We consider that the present procedure is extremely effective as a palliative treatment for distal bowel stenosis, such as in the surgically reconstructed intestine.

A Novel Approach for Endoscopic Papillary Balloon Dilation with the Guidewire Left in the Pancreatic Duct to Ensure Pancreatic Stenting

BACKGROUND/AIMS

Endoscopic papillary balloon dilation (EPBD) was reported to be superior for preserving the function of the sphincter of Oddi and to cause fewer late complications than endoscopic sphincterotomy. If the early complication of post-EPBD pancreatitis can be prevented, EPBD might be useful as long-term outcomes. This study assessed the feasibility of a novel EPBD for the purpose of reliable post-EPBD pancreatic stenting.

METHODOLOGY

Among 1814 ER-CPs, in 17 patients undergoing biliary cannulation with pancreatic duct guidewire placement method, we performed EPBD with the guidewire left in the pancreatic duct by the two-devices-in-one-channel method. This approach employed in order to ensure pancreatic stenting.

RESULTS

Procedures were successfully performed without the guidewire displacement, and pancreatic stents were easily placed in all patients. Post-EPBD pancreatitis occurred in only 1 patient (5.9%), and the severity was mild. Asymptomatic hyperamylasemia occurred in 3 patients (17.6%). There were no other early complications. The mean serum amylase levels (mean ± SD) before, 1 day, and 2 days after procedure were 81.4 ± 61.9, 301.2 ± 273.0, and 220.0 ± 177.6 IU/L.

CONCLUSIONS

EPBD with a guidewire left in the pancreatic duct is useful method allowing reliable pancreatic stenting and may contribute to the prevention of pancreatitis.

Thrombomodulin in the management of acute cholangitis-induced disseminated intravascular coagulation

AIM: To evaluate the need for thrombomodulin (rTM) therapy for disseminated intravascular coagulation (DIC) in patients with acute cholangitis (AC)-induced DIC.

METHODS: Sixty-six patients who were diagnosed with AC-induced DIC and who were treated at our hospital were enrolled in this study. The diagnoses of AC and DIC were made based on the 2013 Tokyo Guidelines and the DIC diagnostic criteria as defined by the Japanese Association for Acute Medicine, respectively. Thirty consecutive patients who were treated with rTM between April 2010 and September 2013 (rTM group) were compared to 36 patients who were treated without rTM (before the introduction of rTM therapy at our hospital) between January 2005 and January 2010 (control group). The two groups were compared in terms of patient characteristics at the time of DIC diagnosis (including age, sex, primary disease, severity of cholangitis, DIC score, biliary drainage, and anti-DIC drugs), the DIC resolution rate, DIC score, the systemic inflammatory response syndrome (SIRS) score, hematological values, and outcomes. Using logistic regression analysis based on multivariate analyses, we also examined factors that contributed to persistent DIC.

RESULTS: There were no differences between the rTM group and the control group in terms of the patients’ backgrounds other than administration. DIC resolution rates on day 9 were higher in the rTM group than in the control group (83.3% vs 52.8%, P < 0.01). The mean DIC scores on day 7 were lower in the rTM group than in the control group (2.1 ± 2.1 vs 3.5 ± 2.3, P = 0.02). The mean SIRS scores on day 3 were significantly lower in the rTM group than in the control group (1.1 ± 1.1 vs 1.8 ± 1.1, P = 0.03). Mortality on day 28 was 13.3% in the rTM group and 27.8% in the control group; these rates were not significantly different (P = 0.26). Multivariate analysis identified only the absence of biliary drainage as significantly associated with persistent DIC (P < 0.01, OR = 12, 95%CI: 2.3-60). Although the difference did not reach statistical significance, primary diseases (malignancies) (P = 0.055, OR = 3.9, 95%CI: 0.97-16) and the non-use of rTM had a tendency to be associated with persistent DIC (P = 0.08, OR = 4.3, 95%CI: 0.84-22).

CONCLUSION: The add-on effects of rTM are anticipated in the treatment of AC-induced DIC, although biliary drainage for AC remains crucial.

Endoscopic retrograde cholangiography using an anterior oblique-viewing endoscope in patients with altered gastrointestinal anatomy

BACKGROUND

Endoscopic retrograde cholangiopancreatography (ERCP) is technically more challenging in patients who have undergone gastrointestinal (GI) reconstruction.

AIMS

The aim of this study was to evaluate the utility of the anterior oblique-viewing endoscope (AOE) for ERCP in patients with a retained major duodenal papilla after GI reconstruction.

METHODS

This was a retrospective study involving 40 patients (50 procedures) with a retained papilla after GI reconstruction who underwent ERCP using AOE. Reconstruction consisted of Billroth II gastrectomy (BII) in 25 patients (30 procedures) and Roux-en-Y anastomosis (RY) in 15 patients (20 procedures). In RY cases, the long single-balloon enteroscope (LSBE) was exchanged with AOE after reaching the papilla.

RESULTS

The overall rate of reaching the papilla using AOE was 90.0 % (45/50) [BII; 86.7 % (26/30), RY; 95.0 % (19/20)]. The overall rate of biliary cannulation was 97.8 % (44/45) [BII; 100 % (26/26), RY; 94.7 % (18/19)], and the rate of biliary cannulation for intact papilla was 96.6 % (28/29) [BII; 100 % (14/14), RY; 93.3 % (14/15)]. Treatment success rate in cases of successful biliary cannulation was 97.7 % (43/44) [BII; 100 % (26/26), RY; 94.4 % (17/18)]. The rate of adverse events was 6.0 % (3/50) [BII; 3.3 % (1/30), RY; 10.0 % (2/20)], with mild pancreatitis occurring in 3 cases.

CONCLUSIONS

High biliary cannulation and treatment rates can be achieved during ERCP using AOE in altered GI anatomy cases with a retained papilla, as long as the papilla can be reached. In RY cases, exchanging AOE with LSBE is useful after reaching the papilla.

Need for pancreatic stenting after sphincterotomy in patients with difficult cannulation

AIM: To investigate the need for pancreatic stenting after endoscopic sphincterotomy (EST) in patients with difficult biliary cannulation.

METHODS: Between April 2008 and August 2013, 2136 patients underwent endoscopic retrograde cholangiopancreatography (ERCP)-related procedures. Among them, 55 patients with difficult biliary cannulation who underwent EST after bile duct cannulation using the pancreatic duct guidewire placement method (P-GW) were divided into two groups: a stent group (n = 24; pancreatic stent placed) and a no-stent group (n = 31; no pancreatic stenting). We retrospectively compared the two groups to examine the need for pancreatic stenting to prevent post-ERCP pancreatitis (PEP) in patients undergoing EST after biliary cannulation by P-GW.

RESULTS: No differences in patient characteristics or endoscopic procedures were observed between the two groups. The incidence of PEP was 4.2% (1/24) and 29.0% (9/31) in the Stent and no-stent groups, respectively, with the no-stent group having a significantly higher incidence (P = 0.031). The PEP severity was mild for all the patients in the stent group. In contrast, 8 had mild PEP and 1 had moderate PEP in the no-stent group. The mean serum amylase levels (means ± SD) 3 h after ERCP (183.1 ± 136.7 vs 463.6 ± 510.4 IU/L, P = 0.006) and on the day after ERCP (209.5 ± 208.7 vs 684.4 ± 759.3 IU/L, P = 0.002) were significantly higher in the no-stent group. A multivariate analysis identified the absence of pancreatic stenting (P = 0.045; odds ratio, 9.7; 95%CI: 1.1-90) as a significant risk factor for PEP.

CONCLUSION: In patients with difficult cannulation in whom the bile duct is cannulated using P-GW, a pancreatic stent should be placed even if EST has been performed.

[Three cases of liver abscess associated with the Streptococcus anginosus group]

Reports of pyogenic liver abscess (PLA) caused by the Streptococcus anginosus group (SAG) have increased. Coinfection with SAG and anaerobic bacteria enhances the tendency for abscess formation. Furthermore, it has been reported that SAG infection results in pylethrombophlebitis as a complication. We experienced 3 cases of PLA caused by SAG: one case was complicated by the development of pylethrombophlebitis and the other 2 cases had coinfection with anaerobic bacteria. We report these cases together with bibliographic consideration of 23 cases previously reported in Japan.

COX-2 Gene Promoter Methylation in Patients Infected with Helicobacter Pylori

Cyclooxygenase (COX) plays a critical role in peptic ulcer development. COX-2 contains CpG islands in promoter area, which suggests possible epigenetic mechanisms of gene silencing. We evaluated COX-2 gene promoter methylation levels in the gastric mucosa of patients with various gastric diseases. DNA was extracted from endoscopic biopsy materials collected from the gastric mucosa. The methylation levels of the COX-2 gene promoter were measured quantitatively by using pyrosequencing. COX-2 mRNA expression in Kato III and AGS cells was measured using real-time PCR. COX-2 gene promoter methylation levels were significantly higher in Helicobacter pylori (HP)-positive cases than in HP-negative cases (27.5% vs. 8.1%, respectively, P < 0.001). COX-2 gene promoter methylation levels in patients in whom HP was successfully eradicated were significantly lower than those in HP-positive cases (18.7% vs. 27.5%, respectively, P < 0.01). We then investigated the effects of COX-2 gene promoter methylation on its mRNA expression in vitro. COX-2 mRNA expression was not observed in Kato III cells, despite the addition of the protein kinase C stimulator α-phorbol 12,13-dibutyrate (PDBu). COX-2 expression was observed after the addition of the demethylating agent 5-Aza-dC and was enhanced by PDBu. HP infection caused a significant increase in the methylation levels of the COX-2 gene promoter in the gastric mucosa. In addition to transcriptional regulation, COX-2 expression is regulated through epigenetic mechanisms.

Use of antithrombin and thrombomodulin in the management of disseminated intravascular coagulation in patients with acute cholangitis

Background/Aims

To evaluate the usefulness and safety of treating disseminated intravascular coagulation (DIC) complicating cholangitis primarily with antithrombin (AT) and thrombomodulin (rTM).

Methods

A DIC treatment algorithm was determined on the basis of plasma AT III levels at the time of DIC diagnosis and DIC score changes on treatment day 3. Laboratory data and DIC scores were assessed prospectively at 2-day intervals.

Results

DIC reversal rates >75% were attained on day 7. In the DIC reversal group, statistically significant differences from baseline were observed in interleukin-6 and C-reactive protein levels within 5 days. Patients with no DIC score improvements after treatment with AT alone experienced slow improvement on a subsequent combination therapy with rTM. Although a subgroup with biliary drainage showed greater improvement in DIC scores than did the nondrainage subgroup, the mean DIC score showed improvement even in the nondrainage subgroup alone. Gastric cancer bleeding that was treated conservatively occurred in one patient. As for day 28 outcomes, three patients died from concurrent malignancies.

Conclusions

Although this algorithm was found to be useful and safe for DIC patients with cholangitis, it may be better to administer rTM and AT simultaneously from day 1 if the plasma AT III level is less than 70%.

Role of nuclear background and in vivo environment in variable segregation behavior of the aging-dependent T414G mutation at critical control site for human fibroblast mtDNA replication

Previous work had shown a large accumulation (up to 50% of mtDNA) of a noninherited T414G transversion at a critical control site for mtDNA replication in skin fibroblasts from the majority of human subjects above 65 years old, and its absence in younger individuals. In the present studies, long-term in vitro culture of several fibroblasts populations carrying the heteroplasmic T414G mutation revealed an outgrowth of the mutant cells by wild-type cells. This observation supported the previous conclusion that the mutation accumulation is an in vivo phenomenon, while, at the same time, indicating intrinsic physiological differences between mutant and wild-type cells. Furthermore, subcloning experiments revealed a striking mosaic distribution of the mutation in the original fibroblasts populations, as shown by its presence, in heteroplasmic or homoplasmic form, in a fraction (18-32%) of the fibroblasts, and its absence in the others. In other investigations, transfer of mitochondria from mutation-carrying fibroblasts into mtDNA-less 143B.TK- rho0 206 cells revealed the persistence of the mosaic distribution of the mutation, however, with a near-complete shift to homoplasmy. The generality of the latter phenomenon would exclude a founder effect by one or few mitochondria in the transformation experiments, and would rather point to the important role of the nuclear background in the in vitro behavior of the T414G mutation. The stability of the homoplasmic mutation in rho0 cell transformants provides a powerful tool for analyzing its biochemical effects.

Muscle-specific mutations accumulate with aging in critical human mtDNA control sites for replication

The recently discovered aging-dependent large accumulation of point mutations in the human fibroblast mtDNA control region raised the question of their occurrence in postmitotic tissues. In the present work, analysis of biopsied or autopsied human skeletal muscle revealed the absence or only minimal presence of those mutations. By contrast, surprisingly, most of 26 individuals 53 to 92 years old, without a known history of neuromuscular disease, exhibited at mtDNA replication control sites in muscle an accumulation of two new point mutations, i.e., A189G and T408A, which were absent or marginally present in 19 individuals younger than 34 years. These two mutations were not found in fibroblasts from 22 subjects 64 to 101 years of age (T408A), or were present only in three subjects in very low amounts (A189G). Furthermore, in several older individuals exhibiting an accumulation in muscle of one or both of these mutations, they were nearly absent in other tissues, whereas the most frequent fibroblast-specific mutation (T414G) was present in skin, but not in muscle. Among eight additional individuals exhibiting partial denervation of their biopsied muscle, four subjects >80 years old had accumulated the two muscle-specific point mutations, which were, conversely, present at only very low levels in four subjects < or =40 years old. The striking tissue specificity of the muscle mtDNA mutations detected here and their mapping at critical sites for mtDNA replication strongly point to the involvement of a specific mutagenic machinery and to the functional relevance of these mutations.

Aging-dependent large accumulation of point mutations in the human mtDNA control region for replication

Progressive damage to mitochondrial DNA (mtDNA) during life is thought to contribute to aging processes. However, this idea has been difficult to reconcile with the small fraction of mtDNA so far found to be altered. Here, examination of mtDNA revealed high copy point mutations at specific positions in the control region for replication of human fibroblast mtDNA from normal old, but not young, individuals. Furthermore, in longitudinal studies, one or more mutations appeared in an individual only at an advanced age. Some mutations appeared in more than one individual. Most strikingly, a T414G transversion was found, in a generally high proportion (up to 50 percent) of mtDNA molecules, in 8 of 14 individuals above 65 years of age (57 percent) but was absent in 13 younger individuals.

Comprehensive, rapid and sensitive detection of sequence variants of human mitochondrial tRNA genes

In the present study, a comprehensive, rapid and sensitive method for screening sequence variation of the human mitochondrial tRNA genes has been developed. For this purpose, the denaturing gradient gel electrophoresis (DGGE) technique has been appropriately modified for simultaneous mutation analysis of a large number of samples and adapted so as to circumvent the problems caused by the anomalous electrophoretic behavior of DNA fragments encoding tRNA genes. Eighteen segments of mitochondrial DNA (mtDNA), each containing a single uniform melting domain, were selected to cover all tRNA-encoding regions using the computer program MELT94. All 18 segments were simultaneously analyzed by electrophoresis through a single broad range denaturing gradient gel under rigorously defined conditions, which prevent band broadening and other migration abnormalities from interfering with detection of sequence variants. All base substitutions tested, which include six natural mutations and 14 artificially introduced ones, have been detected successfully in the present study. Several types of evidence strongly suggest that the anomalous behavior in DGGE of tRNA gene-containing mtDNA fragments reflects their tendency to form temporary or stable alternative secondary structures under semi-denaturing conditions. The high sensitivity of the method, which can detect as low as 10% of mutant mtDNA visually, makes it valuable for the analysis of heteroplasmic mutations.

An acrosomal protein, sp32, in mammalian sperm is a binding protein specific for two proacrosins and an acrosin intermediate

An acrosomal protein, sp32, was completely purified from acid extracts of ejaculated porcine sperm. Purified sp32 gave a single 32-kDa protein band on SDS-polyacrylamide gel electrophoresis and was characterized as a binding protein specific for 55-, 53-, and 49-kDa forms of (pro)acrosin. This protein was not capable of binding a 43-kDa acrosin intermediate and 35-kDa mature acrosin. sp32 significantly accelerated autoactivation of proacrosin at a basic pH in vitro and affected the maturation pathway of proacrosin. In the presence of sp32, the 49-kDa acrosin intermediate from the 55- and 53-kDa proacrosins was accumulated, instead of the 43-kDa acrosin intermediate. These results suggest that sp32 interacts with both the amino- and carboxyl-terminal sequences of the 53-kDa proacrosin. The cDNA clones coding for porcine and guinea pig sp32 have been identified from testis cDNA libraries in lambda gt11. The deduced amino acid sequence indicates that sp32 is initially synthesized as a 61-kDa precursor protein with a putative signal peptide at the amino terminus. The carboxyl-terminal half of the precursor molecule corresponds to the mature sp32. Thus, sp32 is produced by post-translational modification of the precursor. The binding of sp32 to proacrosin may be involved in packaging the acrosin zymogen into the acrosomal matrix.

Structure and organization of the gene encoding a mouse mitochondrial stress-70 protein

We have previously found that an antigenic protein specific for C3H strain mouse (C3H strain-specific antigen, CSA) is identical to peptide-binding protein 74 (PBP74). PBP74/CSA is a novel member of the stress-70 protein family in mitochondria. In this study, mouse genomic clones encoding PBP74/CSA, including the 5'- and 3'-flanking regions of the gene, have been isolated and sequenced. The PBP74/CSA gene contained 17 exons interrupted by 16 introns. Two dimeric repeats of the consensus sequence of the heat-shock element are present in the 5'-flanking region of the PBP74/CSA gene. Moreover, the first intron is interrupted within the amino-terminal leader sequence, the pattern of which is similar to that of cytochrome c1 located in the mitochondria.

Antigenic protein specific for C3H strain mouse is a mitochondrial stress-70 protein

Cells derived from C3H strain mouse produce an antigenic protein (CSA) specific for this strain [Kusakabe, M., et al. (1988) J. Cell Biol. 107, 257-265]. To examine the molecular basis of CSA, cDNA cloning of the antigenic protein was carried out. The deduced amino acid sequence demonstrates that CSA is the same protein as peptide-binding protein 74 (PBP74), a novel member of the stress-70 family. However, comparison of the PBP74/CSA sequences between C3H/HeN and BALB/c strain mice reveals the substitution of two amino acids in the substrate-recognition domain of the stress-70 protein. Western blot analysis indicates that one out of these two residues, arginine at residue 578 in the PBP74/CSA sequence of C3H mouse, contributes to the immunogenicity of CSA. Moreover, the subcellular localization of PBP74/CSA in mitochondria is also demonstrated by immunohistochemical analysis using anti-CSA monoclonal antibody. Thus, it is interesting that a genetic marker sequence in mice is located on the gene encoding a mitochondrial stress-70 protein.

An endoplasmic reticulum protein, calreticulin, is transported into the acrosome of rat sperm

Recently, we purified a Ca(2+)-binding protein from rat spermatogenic cells [Biochem. Biophys. Res. Commun. 176, 135-1364, 1991]. In the present study, this protein was identified as calreticulin, which is a resident protein of the endoplasmic reticulum (ER). Immunohistochemical studies revealed that calreticulin was present in the acrosome of both round spermatids and mature sperm. However, under immunoelectron microscopy, gold-particles were seen over other subcellular structures of spermatocytes, spermatids, and Sertoli cells. When the labeling density in subcellular structures of spermatids was analyzed, the acrosome was found to be most heavily labeled and the Golgi apparatus was second. The complete amino acid sequence of calreticulin, deduced from the cDNA sequence, shares a high degree of identity with that of the analogous mouse protein. The cDNA encoded a protein of 416 amino acids, including a 17-residue NH2-terminal signal sequence. The mature protein contains a KDEL sequence as an ER signal at the COOH terminus. Sperm calreticulin contained no glycosyl moiety. Northern blot analysis of RNAs from purified populations of rat spermatogenic cells indicated that the calreticulin mRNA was present in both pre- and postmeiotic cells. Immunoblot analysis of calreticulin during developmental stages showed that calreticulin was detected in the testis between the ages of 5 and 50 days. Furthermore, purified rat calreticulin contained two Ca(2+)-binding sites, a low affinity/high capacity site and a high affinity/low capacity site. These results suggest that calreticulin, which is not specific to testis, is closely associated with spermatogenesis of rats. This ER protein may be incorporated into the acrosomal vesicle via the Golgi apparatus, without glycosylation, during spermiogenesis, and may play an important role in the regulation of cell functions such as sperm motility and acrosome reaction.

Calreticulin is present in the acrosome of spermatids of rat testis

We have already succeeded in purifying a calcium-binding protein (CalBP) from rat spermatogenic cells [Nakamura et al., Biochem. Biophys. Res. Commun., 176 (1991) 1358]. In this study, the location of this protein within rat testis was examined, using a rabbit antisera for this protein. The antigen was localized on the developing acrosomes during spermiogenesis. The NH2-terminal amino acid sequence obtained for rat CalBP was identical to that of calreticulin obtained for the skeletal muscle of mice and closely resembled that for rabbit calreticulin. On the immunoblot analysis, the purified rat CalBP reacted with an antibody raised against rabbit skeletal muscle calreticulin. The results indicate that calreticulin is present in the acrosome of spermatids of rat testes.

Activation and maturation mechanisms of boar acrosin zymogen based on the deduced primary structure

We have isolated cDNA clones encoding boar acrosin, a serine protease participating in the initial stage of fertilization, from boar testis lambda gt11 cDNA libraries. Nucleotide sequencing of the overlapping clones indicates that the composite cDNA inserts contain 1,391 base pairs coding for a 5'-untranslated region, an open reading frame, a stop codon, a 3'-untranslated region, and a poly(A)+ tail. A polyadenylation signal, AATAAA, is located 33 bases upstream from the start of the poly(A)+ tail. The amino acid sequence deduced from the cDNAs shows that boar acrosin is initially synthesized as a prepro-protein with a 16-residue signal peptide at the NH2 terminus. This signal sequence is followed by a 399-residue sequence corresponding to the acrosin zymogen. COOH-terminal sequence analysis of boar sperm 55-kDa proacrosin and its processed forms indicates that the mature acrosin molecule contains 322 amino acid residues in two polypeptide chains, a 23-residue light chain and a 299-residue heavy chain, with a combined molecular mass of 35,735 Da, and that the 55-kDa proacrosin molecule has 14-, 18-, and 43-residue segments as COOH-terminal extensions that are removed during proacrosin maturation. The COOH-terminal 43-residue segment is rich in proline residues, including an unusual repeat of 23 consecutive prolines. The deduced amino acid sequence of boar acrosin shows a high degree of identity with major portions of other serine proteases, including the active site region and the location of cysteine residues. We conclude that boar acrosin is synthesized as a single-chain polypeptide with the regions corresponding to the light and heavy chains covalently connected by two disulfide bonds, and that the single-chain molecule is autoactivated by cleavage of the Arg23-Val24 bond after removal of the COOH-terminal 14-residue segment, resulting in the formation of the light and heavy chains. This two-chain molecule is then converted to the mature enzyme by removal of the COOH-terminal 18- and 43-residue segments.

Proacrosin activation in the presence of a 32-kDa protein from boar spermatozoa

A 32-kDa protein was purified from acrosomal extracts of ejaculated boar spermatozoa as a complex with 55- and 53-kDa proacrosins. In the presence of the 32-kDa protein, these proacrosins were sequentially converted by autoactivation to a 49-kDa intermediate, a 43-kDa intermediate, and then a 35-kDa mature acrosin. This activation process was consistent with that in the absence of the 32-kDa protein, but differed in producing the 49-kDa form as the predominant acrosin intermediate. Thus, the 32-kDa protein may be a regulatory protein for proacrosin activation. The 49-kDa intermediate was a two-chain polypeptide with the amino-terminal sequences corresponding to those of the light and heavy chains of mature acrosin, whereas the carboxyl-terminal sequence of its heavy chain was identical with that of the 53-kDa proacrosin. These results suggest that the 49-kDa intermediate is produced from 53-kDa proacrosin during proacrosin activation by the cleavage of the peptide bond between Arg-23 and Val-24, which results in the formation of the light and heavy chains.

Activation of boar proacrosin is effected by processing at both N- and C-terminal portions of the zymogen molecule

A mixture of 55 and 53 kDa boar proacrosins was autoactivated at pH 8.5 to produce a 43 kDa intermediate form and a 35 kDa mature acrosin, and each of four forms of (pro)acrosins was isolated. Analysis of the N-terminal sequences of the two proacrosins indicated the existence of a segment corresponding to the acrosin light chain at the N-terminal end of the zymogen. Two N-terminal sequences identical with those of the light and heavy chains were found in the intermediate form and mature acrosin. The proacrosins and the intermediate contained many more proline residues than the mature enzyme. These results indicate that the activation of boar acrosin zymogen is achieved by the removal of a C-terminal segment rich in proline residues and by the cleavage of the Arg23-Val24 bond leading to the formation of the light and heavy chains.