Optimal age to discontinue long-term surveillance of intraductal papillary mucinous neoplasms: comparative cost-effectiveness of surveillance by age

OBJECTIVE

Current guidelines recommend long-term image-based surveillance for patients with low-risk intraductal papillary mucinous neoplasms (IPMNs). This simulation study aimed to examine the comparative cost-effectiveness of continued versus discontinued surveillance at different ages and define the optimal age to stop surveillance.

DESIGN

We constructed a Markov model with a lifetime horizon to simulate the clinical course of patients with IPMNs receiving imaging-based surveillance. We calculated incremental cost-effectiveness ratios (ICERs) for continued versus discontinued surveillance at different ages to stop surveillance, stratified by sex and IPMN types (branch-duct vs mixed-type). We determined the optimal age to stop surveillance as the lowest age at which the ICER exceeded the willingness-to-pay threshold of US$100 000 per quality-adjusted life year. To estimate model parameters, we used a clinical cohort of 3000 patients with IPMNs and a national database including 40 166 patients with pancreatic cancer receiving pancreatectomy as well as published data.

RESULTS

In male patients, the optimal age to stop surveillance was 76-78 years irrespective of the IPMN types, compared with 70, 73, 81, and 84 years for female patients with branch-duct IPMNs <20 mm, =20-29 mm, ≥30 mm and mixed-type IPMNs, respectively. The suggested ages became younger according to an increasing level of comorbidities. In cases with high comorbidity burden, the ICERs were above the willingness-to-pay threshold irrespective of sex and the size of branch-duct IPMNs.

CONCLUSIONS

The cost-effectiveness of long-term IPMN surveillance depended on sex, IPMN types, and comorbidity levels, suggesting the potential to personalise patient management from the health economic perspective.

Balloon endoscopy-assisted endoscopic retrograde cholangiopancreatography for hepatolithiasis in patients with hepaticojejunostomy

BACKGROUND AND AIM

Balloon endoscopy-assisted endoscopic retrograde cholangiopancreatography (BE-ERCP) is an emerging procedure for pancreatobiliary diseases in patients with surgically altered anatomy. However, data on BE-ERCP for hepatolithiasis after hepaticojejunostomy (HJS) are still limited.

METHODS

Stone removal success, adverse events and recurrence were retrospectively studied in consecutive patients who underwent BE-ERCP for hepatolithiasis after HJS between January 2011 and October 2022. Subgroup analysis was performed to compare clinical outcomes between patients who had undergone HJS over 10 years before (past HJS group) and within 10 years (recent HJS group).

RESULTS

A total of 131 patients were included; 39% had undergone HJS for malignancy and 32% for congenital biliary dilation. Scope insertion and complete stone removal were successful in 89% and 73%, respectively. Early adverse events were observed in 9.9%. Four patients (3.1%) developed gastrointestinal perforation but could be managed conservatively. Hepatolithiasis recurrence rate was 17%, 20% and 31% in 1-year, 3-year, and 5-year after complete stone removal. The past HJS group was the only risk factor for failed stone removal (odds ratio 10.4, 95% confidence interval 2.99-36.5) in the multivariable analysis. Failed scope insertion (20%) and failed guidewire or device insertion to the bile duct (22%) were two major reasons for failed stone removal in the past HJS group.

CONCLUSIONS

BE-ERCP for hepatolithiasis was effective and safe in cases with HJS but the complete stone removal rate was low in the past HJS group. Recurrent hepatolithiasis was common and careful follow up study is needed even after complete stone removal.

The impact of biliary stents on the diagnostic yield of endoscopic ultrasound-guided fine needle aspiration for solid pancreatic lesions: A single-center retrospective study and meta-analysis

Background

Endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) is widely used for the pathological diagnosis of solid pancreatic lesions but in cases with obstructive jaundice, transpapillary sampling can be performed during endoscopic retrograde cholangiopancreatography with transpapillary biliary stent placement. Thus, it is still controversial whether EUS-FNA should be performed prior to endoscopic retrograde cholangiopancreatography with biliary stent placement or only after negative transpapillary sampling.

Methods

The accuracy, sensitivity, and specificity of EUS-FNA for solid pancreatic lesions with or without indwelling biliary stents were retrospectively studied in patients undergoing EUS-FNA between January 2017 and December 2021. We also conducted a meta-analysis including our data to compare the accuracy and sensitivity of EUS-FNA with or without biliary stents.

Results

A total of 509 patients (40 with biliary stents and 469 without biliary stents) were included. The accuracy (77.5% vs. 94.5%, p < 0.001) and sensitivity (71.0% vs. 91.7%, p < 0.001) were lower in EUS-FNA with biliary stents. A meta-analysis confirmed that accuracy (odds ratio [OR] of 0.43, 95% confidence interval [CI] 0.29-0.62, p < 0.001) and sensitivity (OR of 0.46, 95% CI 0.33-0.64, p < 0.001) were lower in EUS-FNA with biliary stents. There were no statistically significant differences between plastic stents and self-expandable metallic stents for accuracy or sensitivity.

Conclusions

The presence of biliary stents had a negative impact on the diagnostic performance of EUS-FNA, and EUS-FNA prior to endoscopic retrograde cholangiopancreatography with biliary stent placement should be considered in cases with obstructive jaundice.

Feasibility of comprehensive genomic profiling using endoscopic ultrasound-guided tissue acquisition with a 22-gauge Franseen needle

Aim

Comprehensive genomic profiling (CGP) test for solid tumors is now increasingly utilized in clinical practice, especially in pancreatobiliary cancer, and specimens obtained by endoscopic ultrasound-guided tissue acquisition (EUS-TA) are often submitted for tissue-based CGP test. In this study, we evaluated the feasibility of EUS-TA using a 22-gauge Franseen needle for the CGP test.

Methods

Consecutive patients with solid tumors who underwent EUS-TA using a 22-gauge Franseen needle, and whose tissue samples were pre-checked for suitability for CGP test, were included in this single-center, retrospective analysis. The success rates of appropriate sample collection for CGP evaluated by pathologists (1st quality control) and CGP test (2nd quality control) were evaluated. In addition, The EUS-TA slides were evaluated for the tissue area and tumor area content, using the image software.

Results

A total of 50 cases, with 78% of pancreatic cancer, were included in the analysis. A median of 3 passes of EUS-TA were performed with an adverse event rate of 4%. The success rates for 1st and 2nd quality control for CGP tests were 86% and 76%, respectively. The image analyses suggested EUS-TA specimen did not always fulfill CGP test criteria, with 18% of tissue area ≥16 mm2 and 38% of tumor area content ≥20%, even in cases with successful CGP tests. The suction method yielded a significantly larger amount of DNA but without a significant difference in the multivariate analysis.

Conclusions

The present study demonstrated the feasibility of EUS-TA using a 22-gauge Franseen needle for CGP test.

Fracture of the patella involving inferior pole is associated with postoperative patella baja - A retrospective multicenter study

BACKGROUND

The patella fracture involving of inferior pole fractures (IPF) may be associated with patella baja, However, the clinical impact of this condition remains unclear. This study aims to clarify 1) the incidence of patella baja following patellar fracture surgery, 2) the associated clinical outcomes with and without the presence of patella baja, and 3) the potential correlation between the detection of IPF on CT and the occurrence of patella baja.

METHODS

We conducted a retrospective multicenter study involving 251 patients who underwent surgical treatment for patellar fractures. Patients were divided into the patella baja (PB; n = 49) group and patella norma (PN; n = 202) group. Data collected included demographics, radiographic findings, surgical details, and postoperative complications. We compared these items between PB group and PN group. Logistic regression analyses were used to identify risk factors for patella baja.

RESULTS

Immediately following surgery, 36 (14.3%) patients presented with patella baja which increased to 49 cases (19.5%) at six months postoperatively. There is no statistically significant difference in the demographics, surgical details, clinical outcomes and complication between PB group and PN group. While, in the radiographical assessment, the prevalence of IPF on CT scan in the patella baja group was significantly higher than that in the patella norma group. By logistic regression analysis, IPFP on CT was identified as an independent risk factor for patella baja. (odds ratio 2.11, 95% confidence interval: 1.03-4.33, p = 0.042).

CONCLUSION

In patients with patellar fractures, the incidence of patella baja increased from 14.3% immediately post-surgery to 19.5% at the six-month check-up. No significant differences were observed in clinical outcomes between the patella baja group and the norma group. The patella fracture involving IPF on CT emerged as a predictive factor for patella baja.

Intraductal Papillary Mucinous Neoplasm Surveillance Leads to Early Diagnosis and Better Outcomes of Concomitant Cancer

OBJECTIVE

To examine whether long-term surveillance of intraductal papillary mucinous neoplasms (IPMNs) leads to early diagnosis and better clinical outcomes of pancreatic ductal adenocarcinomas (PDACs) developing concomitantly with IPMNs.

SUMMARY BACKGROUND DATA

Long-term image-based surveillance is recommended for patients with low-risk IPMNs. However, it is unknown whether the surveillance can improve surgical and survival outcomes of patients with concomitant PDACs.

METHODS

Using a prospective single-institutional cohort of 4,620 patients with pancreatic cysts including 3,638 IPMN patients, we identified 63 patients who developed concomitant PDAC during long-term surveillance. We compared overall survival (OS) of 46 cases with concomitant PDAC to that of 460 matched cases diagnosed with non-IPMN-associated PDAC at the same institution. Multivariable hazard ratios and 95% confidence intervals (CIs) for overall mortality were computed using the Cox regression model with adjustment for potential confounders.

RESULTS

Concomitant PDACs were identified at an earlier cancer stage compared to non-IPMN-associated PDACs with 67% and 38% cases identified at stage 2 or earlier, respectively (P<0.001) and 57% and 21% cases with R0 resection, respectively (P<0.001). Compared to non-IPMN-associated PDACs, concomitant PDACs were associated with longer OS (P=0.034) with a multivariable hazard ratio of 0.61 (95% CI, 0.39-0.96). The 5-year survival rate of patients with concomitant PDAC was higher compared to patients with non-IPMN-associated PDAC (34% vs. 18%, respectively; P=0.018).

CONCLUSIONS

The surveillance for patients with IPMNs was associated with early identification of concomitant PDACs and longer survival of patients diagnosed with this malignancy.

Retrospective comparative study of new slim-delivery and conventional large-cell stents for stent-in-stent methods for hilar malignant biliary obstruction

OBJECTIVES

Endoscopic management of unresectable hilar malignant biliary obstruction (HMBO) is technically challenging, and effectiveness of stent-in-stent using large-cell, metal stents was reported. A new, large-cell stent with a 6F tapered delivery system was recently developed. The aim of this study was to compare clinical outcomes of slim-delivery and conventional large-cell stents.

METHODS

This was a multicenter retrospective comparative study of stent-in-stent methods using slim-delivery stents (Niti-S Large Cell SR Slim Delivery [LC slim-delivery]) and conventional stents (Niti-S large-cell D-type; LCD) for unresectable HMBO.

RESULTS

Eighty-three patients with HMBO were included; 31 LC slim-delivery and 52 LCD. Overall technical and clinical success rates were 100% and 90% in LC slim-delivery group and 98% and 88% in LCD group. Use of the LC slim-delivery was associated with shorter stent placement time in the multiple regression analysis, with a stent placement time of 18 and 23 min in LC slim-delivery and LCD groups, respectively. The early adverse event (AE) rate of LC slim-delivery was 10%, with no cholangitis or cholecystitis as compared to 23% in the LCD group. Recurrent biliary obstruction (RBO) rates and time to RBO were comparable between the two groups: 35% and 44%, and 8.5 and 8.0 months in LC slim-delivery and LCD groups, respectively. The major cause of RBO was tumor ingrowth (82%) in the LC slim-delivery group and sludge (43%) and ingrowth (48%) in LCD group.

CONCLUSION

Stent-in-stent methods using LC slim-delivery shortened stent placement time with low early AE rates and comparable time to RBO in patients with HMBO.

Skeletal muscle status and survival among patients with advanced biliary tract cancer

BACKGROUND

Studies have demonstrated a prognostic role of sarcopenia (i.e., loss of skeletal muscle volume and functionality) in patients with various cancer types. In patients with biliary tract cancer, the quantity and quality of skeletal muscles and their serial changes have not been fully investigated in relation to survival outcomes.

METHODS

We identified 386 patients with unresectable or recurrent biliary tract cancer and calculated skeletal muscle index (SMI) and skeletal muscle density (SMD) to estimate muscular quantity and quality, respectively, based on computed tomography images. Using the Cox regression model with adjustment for potential confounders, we calculated hazard ratios (HRs) and 95% confidence intervals (CIs) for progression-free survival (PFS) and overall survival (OS) according to skeletal muscle status and its serial change.

RESULTS

Compared to patients without sarcopenia, patients with sarcopenia were associated with shorter PFS (multivariable HR, 1.60; 95% CI, 1.15-2.22; P = 0.005), but not with OS (P = 0.027) at the adjusted α level of 0.013. SMD at baseline was associated with OS (multivariable HR comparing the extreme quartiles, 1.52; 95% CI, 1.07-2.14; Ptrend = 0.012), but not with PFS (Ptrend = 0.13). A reduction in SMI rather than that in SMD was associated with OS. Progressive disease was a risk factor for reductions in SMI and SMD.

CONCLUSIONS

Skeletal muscle quantity and quality and their serial changes were associated with survival outcomes in patients with advanced biliary tract cancer. Our data highlight the importance of designing nutritional and physical interventions for improvements in skeletal muscle status.

Development and external validation of a nomogram for prediction of post-endoscopic retrograde cholangiopancreatography pancreatitis

BACKGROUND AND AIMS

Endoscopic retrograde cholangiopancreatography (ERCP) is widely performed for management of pancreatobiliary diseases; however, post-ERCP pancreatitis (PEP) remains as an unsolved problem. Although various risk factors for PEP have been reported, the prediction of PEP remains controversial. This study aimed to develop a predictive model for PEP.

METHODS

Consecutive patients undergoing ERCP for biliary indications at two centers were retrospectively studied. Using data from a training cohort, we utilized a multivariable model to select five variables to construct a nomogram. The predictive model was internally and externally validated. Based on the nomogram, the patients were categorized into low-, moderate-, and high-risk groups.

RESULTS

Using the data of 2224 patients in the training cohort, five variables were selected to generate a nomogram: 1) sex, 2) indication for ERCP, 3) difficult cannulation, 4) guidewire insertion into the pancreatic duct, and 5) endoscopic sphincterotomy or sphincteroplasty. The most significant risk factor was endoscopic papillary balloon dilation such as endoscopic sphincterotomy or sphincteroplasty. The bias-corrected concordance index was 0.72 in the training cohort and 0.72 in the validation cohort. Calibration curves for both cohorts demonstrated good agreement between the predicted and observed frequencies of the actual outcome. In the validation cohort, PEP developed in 5.0% and 14% of patients in the moderate- and high-risk groups, respectively.

CONCLUSIONS

We successfully developed a good predictive model for PEP. The prevention of PEP in high risk patients should be investigated further.

Clinical trajectory of intraductal papillary mucinous neoplasms progressing to pancreatic carcinomas during long-term surveillance: a prospective series of 100 carcinoma cases

BACKGROUND

Trajectories of serological and morphological signatures have not been documented in pancreatic carcinogenesis related to intraductal papillary mucinous neoplasms (IPMNs).

METHODS

Using a prospective cohort of 3437 IPMN patients, we identified 100 IPMN patients who developed pancreatic carcinomas during long-term surveillance. We examined serial changes of blood markers (carbohydrate antigen 19-9 [CA19-9], hemoglobin A1c [HbA1c], and pancreatic enzymes) and morphological features (worrisome features and high-risk stigmata) during the prediagnostic period of pancreatic carcinomas, overall and by carcinoma types (IPMN-derived vs. concomitant pancreatic carcinomas).

RESULTS

CA19-9 elevation was observed in 39 patients and was associated with a metastatic stage. Compared to IPMN-derived carcinomas, concomitant carcinomas were more likely to represent CA19-9 elevation (60% vs. 30%, respectively; P = 0.005). HbA1c levels elevated only in 3 patients. Pancreatic enzyme elevation was observed in 18 patients with no differences in frequencies between the carcinoma types. All patients with elevated levels of blood markers had positive findings on cross-sectional imaging. High-risk stigmata or worrisome features were observed in all patients but one with concomitant carcinoma. The most common types of worrisome features were the main pancreatic duct dilatation and CA19-9 elevation in IPMN-derived and concomitant carcinomas, respectively. Compared to IPMN-derived carcinomas, concomitant carcinomas were less likely to harbor high-risk stigmata (16% vs. 86%, respectively; P < 0.001).

CONCLUSIONS

The usefulness of currently available blood biomarkers was limited in early detection of pancreatic carcinomas related to IPMNs. Morphological alterations were well correlated with long-term risk of IPMN-derived carcinomas, but not with that of concomitant carcinomas.

Second Covered and Uncovered Self-Expandable Metal Stents for Recurrent Gastric Outlet Obstruction: A Retrospective Comparative Study

Background: Endoscopic self-expandable metal stent (SEMS) placement is a current mainstay for malignant gastric outlet obstruction (GOO), but symptomatic recurrence due to initial SEMS dysfunction commonly occurs. We aimed to compare the safety and effectiveness of second SEMS for recurrent GOO (RGOO). Methods: Between April 2006 and December 2022, a total of 95 cases with malignant RGOO undergoing second endoscopic SEMS placement were enrolled. Technical and clinical success rates, RGOO, time to RGOO (TRGOO), stent patency rate, adverse events (AE), and overall survival (OS) were retrospectively compared between covered and uncovered SEMS (cSEMS/uSEMS) groups. Risk factors for TRGOO were also explored. Results: Baseline characteristics were well balanced between cSEMS (n = 48) and uSEMS (n = 47) groups, except for the causes of the initial SEMS dysfunction. High technical and clinical success rates with a similar incidence of AE (15% vs. 17%, p = 0.78) and OS (median of 101 vs. 102 days, p = 0.68) were achieved in both groups. There were no statistical differences in cumulative incidence of RGOO (19% vs. 13%, p = 0.58), TRGOO (median, not reached in both groups, p = 0.57), and stent patency rates at 1, 2, and 3 months between the groups (60%, 47% and 26%, respectively vs. 70%, 55% and 38%, respectively). However, TRGOO tended to be longer in cSEMS in cases with RGOO due to tumor ingrowth (median, not reached vs. 111 days, p = 0.19). A Cox regression analysis demonstrated that chemotherapy after second SEMS placement was significantly associated with an improved TRGOO (the hazard ratio of 0.27 [95% confidence interval, 0.08-0.93], p = 0.03). Conclusions: Regardless of the type of SEMS, second SEMS placement was similarly safe and effective for RGOO. The type of second SEMS might be considered based on the cause of initial SEMS dysfunction.

Clinical Outcomes of Intraductal Papillary Mucinous Neoplasms With Dilatation of the Main Pancreatic Duct

BACKGROUND & AIMS

Dilatation of the main pancreatic duct (MPD) has been a surgical indication for intraductal papillary mucinous neoplasms (IPMNs). Few studies have investigated long-term outcomes of IPMNs with MPD dilatation.

METHODS

Among 3610 patients diagnosed with pancreatic cysts between 1994 and 2021, we identified 2829 IPMN patients, including 282 patients with MPD ≥5 mm, and examined short-term (≤6 months) and long-term risks of pancreatic carcinoma. Utilizing competing risks proportional hazards models, we estimated subdistribution hazard ratios for incidence of pancreatic carcinoma with adjustment for potential confounders.

RESULTS

In analyses of short-term outcomes of the 282 patients with MPD dilatation, 72 (26%) patients were diagnosed with pancreatic carcinoma based on surgical or nonsurgical exploration. During long-term follow-up of 168 patients, we documented 24 (14%) patients diagnosed with pancreatic carcinoma (18 with IPMN-derived carcinoma and 6 with concomitant ductal adenocarcinoma). The patients with the MPD = 5-9.9 mm had cumulative incidence rates of pancreatic carcinoma diagnosis of 8.1% (95% confidence interval [CI], 4.3%-13.5%) and 10.0% (95% CI, 5.5%-15.9%) at 2 and 5 years, respectively; and the patients with the MPD ≥10 mm had the corresponding rates of 16.0% (95% CI, 3.6-36.5%) and 33.3% (95% CI, 10.3%-58.8%). The multivariable subdistribution hazard ratios were 2.78 (95% CI, 1.57-4.90) and 7.00 (95% CI, 2.58-19.0) for the MPD = 5-9.9 mm and ≥10 mm (vs <5 mm), respectively.

CONCLUSIONS

IPMNs with MPD dilatation at baseline were associated with higher prevalence and incidence of pancreatic carcinoma compared with IPMNs with no MPD dilatation.

Predictors of postoperative complications of tension band wiring techniques for patella fracture: A retrospective multicenter (TRON group) study

OBJECTIVE

The relationship between postoperative complications and operative techniques of tension band wiring (TBW) is not well studied. We aimed to evaluate the incidence of implant breakage, implant migration, and loss of reduction in patellar fractures treated with TBW and identify radiographic factors associated with these postoperative complications.

METHODS

This multicenter (named, TRON group) retrospective study included 224 patients who underwent open reduction and internal fixation of patella fractures using TBW from January 2016 to December 2020. Radiographic findings were evaluated by experienced orthopedic surgeons, and radiographic outcomes were assessed for K-wire migration, implant breakage, and loss of reduction. Logistic regression analysis was performed to identify radiographic factors associated with postoperative complications.

RESULTS

Implant migration occurred in 44 cases (19.6%), with bending of a single K-wire end identified as a significant risk factor (OR: 12.90; 95% CI: 4.99-33.30; P < 0.001). Implant breakage occurred in 43 cases (19.2%), with a large patella-tension band ratio (OR: 291.0; 95% CI: 19.60-4330; P < 0.001) and a wide distance between K-wires (OR: 1.15; 95% CI: 1.060-1.250; P = 0.001) identified as significant risk factors. Loss of reduction occurred in 5 cases (2.0%), but no significant risk factors were identified.

CONCLUSION

This study highlights the importance of bending both ends of the K-wires and proper placement of the tension band and K-wires in reducing postoperative complications in patellar fractures treated with TBW. Further research is needed to better understand the risk factors associated with loss of reduction.

Increased risk of biliary infection after biliary stent placement in users of proton pump inhibitors

OBJECTIVES

Proton pump inhibitors (PPIs) are widely prescribed medications for gastric acid-induced diseases. Despite the effectiveness of PPIs, recent evidence suggested an increased risk of various bacterial infections in PPI users. The current study was conducted to evaluate the risk of biliary infection after endoscopic biliary stent placement in regular users of PPIs.

METHODS

Consecutive patients with a native papilla who underwent endoscopic retrograde cholangiopancreatography and stent placement for biliary stricture between January 2010 and August 2019 were included in this retrospective study. The cumulative incidences of biliary infection were compared between regular and non-regular PPI users.

RESULTS

During the study period, 270 regular PPI users and 146 non-regular PPI users were included in the analyses. Age, gender, and indication of endoscopic retrograde cholangiopancreatography were not different between the two groups. The incidences of biliary infection were 43% in regular PPI users and 36% in non-regular PPI users but the time to biliary infection was significantly shorter in regular PPI users than in non-regular users (28 vs. 87 days, p = 0.01). The cumulative incidence of biliary infection was significantly higher in regular PPI users compared with non-regular users (p = 0.008). The multivariable Cox regression analysis also showed a significantly higher hazard ratio of biliary infection in regular PPI users (1.62 [95% confidence interval 1.16-2.26; p = 0.005]).

CONCLUSIONS

Regular PPI use was associated with a higher risk of biliary infection after endoscopic biliary drainage. Inappropriate PPI use should be avoided.

Early skeletal muscle mass decline is a prognostic factor in patients receiving gemcitabine plus nab-paclitaxel for unresectable pancreatic cancer: a retrospective observational study

PURPOSE

Patients with pancreatic cancer often have cancer cachexia at diagnosis. Recent studies suggested that loss of skeletal muscle mass was related to cancer cachexia, which hindered continuance of chemotherapy and could be one of prognostic factors in pancreatic cancer, however the association remains unclear in patients receiving gemcitabine and nab-paclitaxel (GnP).

METHODS

We retrospectively studied 138 patients with unresectable pancreatic cancer receiving first-line GnP at the University of Tokyo from January 2015 to September 2020. We calculated body composition in CT images before chemotherapy and at initial evaluation, and evaluated the association of both body composition before chemotherapy and its changes at initial evaluation.

RESULTS

Compared by skeletal muscle mass index (SMI) change rate between pre-chemotherapy and initial evaluation, there were statistically significantly differences in the median OS: 16.3 months (95%CI 12.3-22.7) and 10.3 months (95%CI 8.3-18.1) between SMI change rate ≥ -3.5% and < -3.5% groups (P = 0.01). By multivariate analysis for OS, CA19-9 (HR 3.34, 95%CI 2.00-5.57, P < 0.01), PLR (HR 1.68, 95%CI 1.01-2.78, P = 0.04), mGPS (HR 2.32, 95%CI 1.47-3.65, P < 0.01) and relative dose intensity (HR 2.21, 95%CI 1.42-3.46, P < 0.01) were significantly poor prognostic factors. SMI change rate (HR 1.47, 95%CI 0.95-2.28, P = 0.08) showed a trend to poor prognosis. Sarcopenia before chemotherapy was not significantly associated with PFS or OS.

CONCLUSION

Early skeletal muscle mass decline was associated with poor OS. Further investigation is warranted whether the maintenance of skeletal muscle mass by nutritional support would improve prognosis.

Combination of serum human satellite RNA and miR-21-5p levels as a biomarker for pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) has a poor prognosis due to the difficulty of its diagnosis. Because human satellite II (HSATII) RNA, a satellite repeat RNA, is highly and specifically expressed in human PDAC, the serum HSATII RNA level may be a biomarker of PDAC. To measure the serum HSATII RNA level with high sensitivity and reproducibility, we previously developed a convenient method, tandem repeat amplification by nuclease protection (TRAP) combined with droplet digital PCR (ddPCR). Here, we refined the original method by simultaneously measuring the serum miR-21-5p level to enhance the detection of PDAC. The resulting PDAC-Index, constructed using serum HSATII RNA and miR-21-5p levels, discriminated patients with PDAC with high accuracy. We verified the clinical usefulness of the PDAC-Index as a supportive test in difficult-to-diagnose cases. The PDAC-Index has satisfactory diagnostic performance and may routinely be applied for detecting PDAC.

MNX1-HNF1B Axis Is Indispensable for Intraductal Papillary Mucinous Neoplasm Lineages

BACKGROUND & AIMS

Chromatin architecture governs cell lineages by regulating the specific gene expression; however, its role in the diversity of cancer development remains unknown. Among pancreatic cancers, pancreatic ductal adenocarcinoma (PDAC) and intraductal papillary mucinous neoplasms (IPMN) with an associated invasive carcinoma (IPMNinv) arise from 2 distinct precursors, and their fundamental differences remain obscure. Here, we aimed to assess the difference of chromatin architecture regulating the transcriptional signatures or biological features in pancreatic cancers.

METHODS

We established 28 human organoids from distinct subtypes of pancreatic tumors, including IPMN, IPMNinv, and PDAC. We performed exome sequencing (seq), RNA-seq, assay for transposase-accessible chromatin-seq, chromatin immunoprecipitation-seq, high-throughput chromosome conformation capture, and phenotypic analyses with short hairpin RNA or clustered regularly interspaced short palindromic repeats interference.

RESULTS

Established organoids successfully reproduced the histology of primary tumors. IPMN and IPMNinv organoids harbored GNAS, RNF43, or KLF4 mutations and showed the distinct expression profiles compared with PDAC. Chromatin accessibility profiles revealed the gain of stomach-specific open regions in IPMN and the pattern of diverse gastrointestinal tissues in IPMNinv. In contrast, PDAC presented an impressive loss of accessible regions compared with normal pancreatic ducts. Transcription factor footprint analysis and functional assays identified that MNX1 and HNF1B were biologically indispensable for IPMN lineages. The upregulation of MNX1 was specifically marked in the human IPMN lineage tissues. The MNX1-HNF1B axis governed a set of genes, including MYC, SOX9, and OLFM4, which are known to be essential for gastrointestinal stem cells. High-throughput chromosome conformation capture analysis suggested the HNF1B target genes to be 3-dimensionally connected in the genome of IPMNinv.

CONCLUSIONS

Our organoid analyses identified the MNX1-HNF1B axis to be biologically significant in IPMN lineages.

Endoscopic Ultrasound-Guided Tissue Acquisition by 22-Gauge Franseen and Standard Needles for Solid Pancreatic Lesions

Background/Aims

Recently, a three-plane symmetric needle with Franseen geometry was developed for endoscopic ultrasound-guided fine needle biopsy (EUS-FNB). In this retrospective study, tissue acquisition per pass was compared between 22-gauge Franseen FNB and standard fine needle aspiration (FNA) needles in patients with solid pancreatic lesions.

Methods

Consecutive patients who underwent EUS-FNA or EUS-FNB for solid pancreatic lesions between October 2014 and March 2018 were retrospectively studied. The tissue acquisition rate and the diagnostic performance per session, per pass, and at first pass were compared.

Results

A total of 663 passes (300 by the FNB needle and 363 by the standard FNA needle) were performed in 154 patients (71 FNB and 83 FNA). The tissue acquisition rate per session and at first pass in the FNB and FNA groups was 100% and 95% (p=0.13) and 87% and 69% (p=0.007), respectively. The multivariate analysis revealed that among the patients, EUS-FNB (odds ratio, 3.07; p=0.01) was associated with a higher first-pass tissue acquisition rate. While the tissue acquisition rate reached a plateau after the 4th pass with FNA, it reached a plateau after the 2nd pass with FNB. Among the 129 malignant cases, the histological tissue acquisition rate per session was similar (100% and 94%), but the sensitivity by histology alone per session was higher for FNB than for FNA (93% and 73%, p<0.01).

Conclusions

The results of our retrospective analysis indicated that compared with a standard FNA needle, a 22-gauge Franseen FNB needle was associated with a higher first-pass tissue acquisition rate.

ABO Blood Group and Risk of Pancreatic Carcinogenesis in Intraductal Papillary Mucinous Neoplasms

BACKGROUND

ABO blood group has been associated with risks of various malignancies, including pancreatic cancer. No study has evaluated the association of ABO blood group with incidence of pancreatic carcinogenesis during follow-up of patients with intraductal papillary mucinous neoplasms (IPMN).

METHODS

Among 3,164 patients diagnosed with pancreatic cysts at the University of Tokyo (Tokyo, Japan) from 1994 through 2019, we identified 1,815 patients with IPMN with available data on ABO blood group. We studied the association of ABO blood group with incidence of pancreatic carcinoma, overall and by carcinoma types [IPMN-derived carcinoma or concomitant pancreatic ductal adenocarcinoma (PDAC)]. Utilizing competing-risks proportional hazards models, we estimated subdistribution hazard ratios (SHR) for incidence of pancreatic carcinoma with adjustment for potential confounders, including cyst characteristics.

RESULTS

During 11,518 person-years of follow-up, we identified 97 patients diagnosed with pancreatic carcinoma (53 with IPMN-derived carcinoma and 44 with concomitant PDAC). Compared with patients with blood group O, patients with blood groups A, B, and AB had multivariable SHRs (95% confidence intervals) for pancreatic carcinoma of 2.25 (1.25-4.07; P = 0.007), 2.09 (1.08-4.05; P = 0.028), and 1.17 (0.43-3.19; P = 0.76), respectively. We observed no differential association of ABO blood group with pancreatic carcinoma incidence by carcinoma types.

CONCLUSIONS

In this large long-term study, patients with IPMN with blood group A or B appeared to be at higher risk of pancreatic carcinoma compared with those with blood group O.

IMPACT

ABO blood group can be a biomarker for pancreatic cancer risk among patients with IPMNs.

Double Guidewire Technique Using an Uneven Double Lumen Catheter for Endoscopic Ultrasound-Guided Interventions

BACKGROUND

Endoscopic ultrasonography (EUS)-guided interventions are often performed using a single guidewire (SGW), but there are a few reports on the use of double guidewire (DGW) technique to facilitate multiple drainage placement during EUS-guided drainage of pancreatic fluid collections. This DGW technique may have advantages other than multiple drainage placement during EUS-guided interventions such as scope stabilization, support for stone extraction and device insertion.

METHODS

Consecutive patients who underwent EUS-guided interventions between Feb 2012 and Apr 2019 were retrospectively reviewed. The rate and reasons of DGW technique, and clinical outcomes were evaluated. DGW technique was performed, using an uneven double lumen cannula (UDLC), which facilitates insertion of 0.025-in. and 0.035-in. guidewires.

RESULTS

A total of 249 EUS-guided interventions were analyzed, and DGW technique was utilized primarily in 65 cases (25.7%) and as a salvage after failed SGW technique in 18 cases (7.1%). The reasons for DGW technique were 60 multiple drainage placement, 10 scope stabilization, 7 device insertion, 5 safety guidewire, and 4 antegrade stone removal. Insertion of UDLC and DGW was successful in 100%. Technical success rate of preplanned interventions was 92.7% (96.9% in primary DGW and 77.8% in salvage DGW technique). Adverse events were observed in 19.5% after DGW but were not related to DGW technique.

CONCLUSIONS

DGW technique using UDLC during EUS-guided interventions was technically feasible and safe. In addition to multiple drainage insertion, it can potentially support complex EUS-guided interventions.

The impact of age and comorbidity in advanced or recurrent biliary tract cancer receiving palliative chemotherapy

BACKGROUND AND AIM

Limited data are available on age and comorbidity assessment in patients with biliary tract cancer (BTC). This study aimed to evaluate the association of age and comorbidity burden with clinical outcomes of chemotherapy for BTC.

METHODS

Consecutive 197 BTC patients undergoing first-line chemotherapy between 2007 and 2017 were retrospectively studied. Patients were classified to three groups according to the age-adjusted Charlson comorbidity index (ACCI) excluding the score about BTC and progression-free survival, overall survival (OS), and safety were compared.

RESULTS

Fifty-one patients (26%) were elderly (≥ 75 years), and ACCI was 0-2 in 73 patients (37%), 3-4 in 98 (50%), and ≥ 5 in 26 (13%). ACCI was associated with the administration of first-line combination chemotherapy (89% in 0-2, 80% in 3-4, and 64% in ≥ 5, P < 0.01) and second-line chemotherapy (67% in 0-2, 51% in 3-4, and 35% in ≥ 5, P = 0.01). ACCI was prognostic for OS in addition to performance status, disease status, and CA19-9: The hazard ratios in ACCI of 3-4 and ≥ 5 were 1.39 and 1.79, compared with ACCI of 0-2 (P = 0.04). While overall safety profile did not differ by ACCI, higher ACCI score group developed Grade 3-4 neutropenia more frequently (26% in 0-2, 42% in 3-4, and 46% in ≥ 5, P = 0.04).

CONCLUSION

Age and comorbidity burden did affect OS and safety profile in BTC patients undergoing first-line palliative chemotherapy. ACCI can be a simple and useful tool to evaluate the age and comorbidity burden in these patients.

Screening Strategy of Pancreatic Cancer in Patients with Diabetes Mellitus

The incidence of pancreatic cancer (PCa) is increasing worldwide and has become one of the leading causes of cancer-related death. Screening for high risk populations is fundamental to overcome this intractable malignancy. Diabetes mellitus (DM) is classically known as a risk factor for PCa. Recently the reverse causality is in the spotlight, that is to say, DM is considered to be a manifestation of PCa. Numbers of epidemiological studies clarified that new-onset DM (≤2-year duration) was predominant in PCa patients and the relative risk for PCa inversely correlated with duration of DM. Among patients with new-onset DM, elder onset, weight loss, and rapid exacerbation of glycemic control were reported to be promising risk factors and signs, and the model was developed by combining these factors. Several pilot studies disclosed the possible utility of biomarkers to discriminate PCa-associated DM from type 2 DM. However, there is no reliable biomarkers to be used in the practice. We previously reported the application of a multivariate index for PCa based on the profile of plasma free amino acids (PFAAs) among diabetic patients. We are further investigating on the PFAA profile of PCa-associated DM, and it can be useful for developing the novel biomarker in the near future.

Lenvatinib-induced acute acalculous cholecystitis in a patient with hepatocellular carcinoma

The patient was a 67-year-old man with advanced hepatocellular carcinoma (HCC) due to chronic hepatitis B. Due to refractoriness to radiofrequency ablation and transcatheter arterial chemoembolization, lenvatinib, a new oral mutikinase inhibitor, was started with a daily dose of 12 mg. However, on day 6 the patient developed acute-onset, right upper quadrant pain associated with fever; laboratory tests revealed leukocytosis and liver dysfunction. CT scan showed the swollen gallbladder with wall thickening with no evidence of gallstones, and the diagnosis of acute acalculous cholecystitis was made. After the resolution of cholecystitis by antibiotics and endoscopic nasogallbladder drainage placement, lenvatinib was resumed at a reduced daily dose of 4 mg. However, acute acalculous cholecystitis recurred, supporting lenvatinib as a cause of acute acalculous cholecystitis. Using the Naranjo adverse drug reaction probability scale, a score of 6 was derived, which indicates that this adverse event was probably caused by lenvatinib. In summary, we present a patient with advanced HCC who underwent repeated episodes of acute acalculous cholecystitis as a rare adverse event associated with lenvatinib.

Long-term Risk of Malignancy in Branch-Duct Intraductal Papillary Mucinous Neoplasms

BACKGROUND & AIMS

Long-term outcomes of patients with branch-duct intraductal papillary mucinous neoplasms (IPMNs), particularly those after 5 years of surveillance, have not been fully evaluated in large studies. We analyzed incidences of IPMN-derived carcinoma and concomitant ductal adenocarcinoma (pancreatic ductal adenocarcinoma [PDAC]) over 20 years in a large population of patients.

METHODS

We identified 1404 consecutive patients (52% women; mean age, 67.5 years) with a diagnosis of branch-duct IPMN, from 1994 through 2017, at the University of Tokyo in Japan. Using a competing risk analysis, we estimated cumulative incidence of pancreatic carcinoma, overall and by carcinoma type. We used competing risks proportional hazards models to estimate subdistribution hazard ratios (SHRs) for incidences of carcinomas. To differentiate IPMN-derived and concomitant carcinomas, we collected genomic DNA from available paired samples of IPMNs and carcinomas and detected mutations in GNAS and KRAS by polymerase chain reaction and pyrosequencing.

RESULTS

During 9231 person-years of follow-up, we identified 68 patients with pancreatic carcinomas (38 patients with IPMN-derived carcinomas and 30 patients with concomitant PDACs); the overall incidence rates were 3.3%, 6.6%, and 15.0% at 5, 10, and 15 years, respectively. Among 804 patients followed more than 5 years, overall cumulative incidence rates of pancreatic carcinoma were 3.5% at 10 years and 12.0% at 15 years from the initial diagnosis. The size of the IPMN and the diameter of the main pancreatic duct associated with incidence of IPMN-derived carcinoma (SHR 1.85; 95% confidence interval 1.38-2.48 for a 10-mm increase in the IPMN size and SHR 1.56; 95% confidence interval 1.33-1.83 for a 1-mm increase in the main pancreatic duct diameter) but not with incidence of concomitant PDAC.

CONCLUSIONS

In a large long-term study of patients with branch-duct IPMNs, we found the 5-year incidence rate of pancreatic malignancy to be 3.3%, reaching 15.0% at 15 years after IPMN diagnosis. We observed heterogeneous risk factor profiles between IPMN-derived and concomitant carcinomas.

Natural history of asymptomatic bile duct stones and association of endoscopic treatment with clinical outcomes

BACKGROUND

Due to increasing opportunities for abdominal imaging studies, bile duct stones are occasionally diagnosed without any symptoms. However, there has been no consensus on the management of asymptomatic bile duct stones. We conducted a retrospective longitudinal cohort study to investigate the natural history of asymptomatic bile duct stones and clinical outcomes according to the timing of endoscopic removal.

METHODS

We identified consecutive patients who were diagnosed with asymptomatic common bile duct stones and categorized into those who were followed up with stones in situ (wait-and-see group) and those who received early endoscopic stone removal (intervention group). Cumulative incidence functions of biliary complications were estimated and compared between the groups.

RESULTS

We included 191 patients (114 patients in the wait-and-see group and 77 patients in the intervention group). In the wait-and-see group, the cumulative incidence of biliary complications was 6.1% at 1 year, 11% at 3 years, and 17% at 5 years. Asymptomatic disappearance of stones was observed in 22 patients (19%). Procedure-related adverse events of early endoscopic stone removal of asymptomatic stones were observed in 25 (32%) patients including 4 (5.2%) with severe pancreatitis. The cumulative incidence function of biliary complications did not differ by treatment strategies (P = 0.55).

CONCLUSIONS

Biliary complications occurred in a substantial proportion of patients with asymptomatic bile duct stones, but early endoscopic removal appeared to have little effect on the prevention of further biliary complications. Given the risk of procedure-related pancreatitis, the wait-and-see strategy may become a management option of asymptomatic stones.

A case of laparoscopic fenestration surgery for pelvic lymphocele occurring after laparoscopic radical prostatectomy

A 76-year-old Japanese man visited a nearby medical clinic complaining of abdominal distention. He had undergone extraperitoneal laparoscopic prostatectomy at our institution 5 months before the onset of abdominal distention. An imaging study revealed a large cystic lesion, and biochemical examination of a sample obtained via cyst puncture led to a diagnosis of lymphocele. As the lymphocele was resistant to puncture, drainage, and sclerotherapy with minomycin, laparoscopic fenestration was performed. Although the patient developed an adhesive ileus postoperatively, the cyst has not recurred. Fenestration surgery is a feasible option for lymphocele refractory to various conservative therapies.

Second-line chemotherapy in patients with advanced or recurrent biliary tract cancer: a single center, retrospective analysis of 294 cases

Purpose The survival benefit of first-line chemotherapy (CT1) for biliary tract cancer (BTC) is now established but the role of second-line chemotherapy (CT2) has not been fully elucidated yet. Methods Consecutive advanced BTC patients receiving CT1 between 2000 and 2016 were retrospectively studied. We investigated the safety and efficacy of CT2, prognostic factors for residual survival after CT1, and explored subgroups who would benefit from CT2. Results Among 294 patients receiving CT1 for advanced BTC, CT2 was given in 139 patients (47%). CT2 provided a response rate of 4%, a disease control rate of 52%, a median progression-free survival of 2.8 and overall survival of 7.7 months, respectively. CT2 was associated with longer residual survival after CT1 (hazard ratio [HR] 0.61, p < 0.01), as well as PS of 0-1 (HR 0.53, p < 0.01), best response to CT1 of PD (HR 1.46, p = 0.01), and CEA ≥5.0 ng/mL (HR 1.69, p < 0.01). The effects of CT2 were homogeneous across almost all subgroups but were more prominent in patients with age ≥ 70 years (HR 0.32, p for interaction =0.02), CA19-9 ≥ 200 IU/mL (HR 0.41, p for interaction = 0.08) and CEA ≥5.0 ng/mL (HR 0.41, p for interaction = 0.06). Conclusions The introduction rate of CT2 was 47%. Although the efficacy of CT2 was modest in terms of tumor response, it was associated with better survival. Further investigations are necessary both to develop more effective regimens and to select patients who will benefit from CT2.

Ecological properties of shoot- and single seeds in a hardwood, Zelkova serrata

The data presented in this paper is supporting the research article　“Variable seed behavior increases recruitment success of a hardwood tree, Zelkova serrata, in spatially heterogeneous forest environments” (Oyama et al., 2018) [1]. We provided the data of several ecological properties of the two types of the seeds (i.e. shoot seeds vs. single seeds) with distinctly different dispersal behaviors. We provide data of terminal velocity, which was measured by releasing 50 replicates of each seed type from a height of 5.0 m in dead air space in a gymnasium. We also show the data of germination cue [i.e. red:far-red (R:FR) ratios], which was examined in plant growth chambers that received three distinct R:FR ratios (0.1, 0.4, and 1.0; 16 h photoperiod) or no illumination. Further, we show the data of the rates of multi-locus outcrossing rates and biparental inbreeding in each of single- and shoot seeds. The mating system parameters were estimated by assaying a total of 80 shoot seeds and 70 single seeds that were randomly collected from Parent 1 and Parent 2 for five microsatellite loci. Finally, we show the data of hemispherical canopy photographs, which were taken at different distance from the adults using a digital camera equipped with a fisheye lens.

An In Vitro Human Liver Model by iPSC-Derived Parenchymal and Non-parenchymal Cells

During liver development, hepatoblasts and liver non-parenchymal cells (NPCs) such as liver sinusoidal endothelial cells (LSECs) and hepatic stellate cells (HSCs) constitute the liver bud where they proliferate and differentiate. Accordingly, we reasoned that liver NPCs would support the maturation of hepatocytes derived from human induced pluripotent stem cells (hiPSCs), which usually exhibit limited functions. We found that the transforming growth factor β and Rho signaling pathways, respectively, regulated the proliferation and maturation of LSEC and HSC progenitors isolated from mouse fetal livers. Based on these results, we have established culture systems to generate LSECs and HSCs from hiPSCs. These hiPSC-derived NPCs exhibited distinctive phenotypes and promoted self-renewal of hiPSC-derived liver progenitor cells (LPCs) over the long term in the two-dimensional culture system without exogenous cytokines and hepatic maturation of hiPSC-derived LPCs. Thus, a functional human liver model can be constructed in vitro from the LPCs, LSECs, and HSCs derived from hiPSCs.

Community-based screening intervention for depression affects suicide rates among middle-aged Japanese adults

BACKGROUND

It has been suggested that screening interventions may be effective for suicide prevention. Few studies, however, have reported their effects on outcome measures, including death by suicide among middle-aged adults.

METHOD

We used a quasi-experimental parallel cluster design with matched community-based intervention and control municipalities (total eligible population: 90 000) in Japan. At-risk residents within the intervention area were invited for universal depression screening and subsequent care/support. We compared changes in suicide incidence of adults aged 40-64 years for the 4-year pre- and post-implementation periods in the intervention group with the control group and the whole country. Incidence rate ratios (IRRs) of the outcomes were adjusted for age group, gender and interaction terms, using mixed-effects negative binomial regression models. Suicide rates among intervention and control subgroups were compared.

RESULTS

The screening procedure was offered to 52% of the intervention group, and 61% of those contacted responded over the implementation period. Suicide rates decreased more in the intervention group [IRR 0.57, 95% (CI) 0.41-0.78; F 1,36 = 12.52, p = 0.001] than the control group (IRR proportion 1.63, 95% CI 1.06-2.48; F 1,82 = 5.20, p = 0.025) or the whole country (IRR proportion 1.64, 95% CI 1.16-2.34; F 1,42 = 8.21, p = 0.006). Sensitivity analyses confirmed the results from the primary analysis. There were lower suicide rates among both respondents and non-respondents to the screening than in the control group during the implementation period.

CONCLUSIONS

Prevention efforts involved in the depression screening intervention were probably successful in reducing suicide rates.

The Figure-L Unilateral Mini-Sternotomy for Anterior Mediastinal Tumor

We performed a figure-L unilateral mini-sternotomy for anterior mediastinal tumor resection in ten patients. Pathological diagnosis among the ten included six thymomas, three mature teratomas including one with a seminoma component, and one thymic cyst. Mean tumor length was 7 x 5 x 4 cm. The required skin incision was 8 cm in mean length. The third intercostal space was transected in six cases, the fourth intercostal space in four cases. Bilateral internal thoracic arteries were preserved in all cases. All tumors were completely resected without complications during the procedure. Mean operating time was 106 minutes (range 85 to 120 minutes). Postoperative hospital stay ranged from three to seven days without any complications. All patients were alive at the end of a mean follow-up period of 39 months (range 3 to 60 months). The figure-L unilateral mini-sternotomy is considered an effective and useful minimally invasive approach for anterior mediastinal tumors.

Haptic reproduction and interactive visualization of a beating heart for cardiovascular surgery simulation

This paper aims to achieve haptic reproduction and real-time visualization of a beating heart for cardiac surgery simulation. Unlike most forgoing approaches, the authors focus on time series datasets and propose a new framework for interactive simulation of active tissues. The framework handles both detection and response of collisions between a manipulator and a beating virtual heart. Physics-based force feedback of autonomous cardiac motion is also produced based on a stress-pressure model, which is adapted to elastic objects filled with fluid. Time series datasets of an adult man were applied to an integrated simulation system with a force feedback device. The system displays multi-dimensional representation of a beating heart and provides a basic training environment for surgical palpation. Finally, results of measurement and medical assessment confirm the achieved quality and performance of the presented framework.

Haptic reproduction and interactive visualization of a beating heart based on cardiac morphology

A goal of this work is proposal and construction of simulation methods of haptic reproduction and interactive visualization of a beating heart in cardiovascular surgical training and education. The data for the beating heart model was obtained from ECG-gated 3D MRI of a normal volunteer. The elastic information was assumed as a uniform value with clinically experienced elasticity. Using a real-time 3D graphics and a haptic device, a simulation environment of the beating heart was designed and implemented. After the construction, some cardiovascular surgeons evaluated the implemented system. Its visualization and haptic expression were scored excellent, but some details in haptic interface were remained to be improved. Finally, for more realistic cardiovascular surgical simulation, future development of the method is discussed.

Inhibitor complexes of the Pseudomonas serine-carboxyl proteinase

Crystal structures of the serine-carboxyl proteinase from Pseudomonas sp. 101 (PSCP), complexed with a number of inhibitors, have been solved and refined at high- to atomic-level resolution. All of these inhibitors (tyrostatin, pseudo-tyrostatin, AcIPF, AcIAF, and chymostatin, as well as previously studied iodotyrostatin and pseudo-iodotyrostatin) make covalent bonds to the active site Ser287 through their aldehyde moieties, while their side chains occupy subsites S1-S4 of the enzyme. The mode of binding of the inhibitors is almost identical for their P1 and P2 side chains, while significant differences are observed for P3 and P4 (if present). Kinetic parameters for the binding of these nanomolar inhibitors to PSCP have been established and correlated with the observed mode of binding. The preferences of this enzyme for a larger side chain in P2 as well as Tyr or Phe in P1 are explained by the size, shape, and characteristics of the S2 and S1 regions of the protein structure, respectively. Networks of hydrogen bonds involving glutamic and aspartic acids have been analyzed for the atomic-resolution structure of the native enzyme. PSCP contains a calcium-binding site that consists of Asp328, Asp348, three amide carbonyl groups, and a water molecule, in almost perfect octahedral coordination. The presence of Ca(2+) cation is necessary for the activity of the enzyme.

Epidemiology of suicidal ideation and help-seeking behaviors among the elderly in Japan

This study offers an analysis of the elderly (over 65 years of age) among a general community population in terms of the percentages of: (i) persons with recurring thoughts of death and/or of committing suicide, and (ii) people who have consulted others, including medical professionals, with regard to these problems. Among 433 elderly over the age of 65 in one community in a town in Aomori Prefecture, 358 agreed to participate in the project. Forty-four participants (12.3%) responded that they had either 'thoughts of death' or 'thoughts of suicide', and these thoughts had continued for more than 2 weeks in 12 participants (3.4%). Only 15 of the 44 suicidal elderly responded that they had consulted someone about their problems. Although there are many elderly people exhibiting a subclinical depressive state with recurring thoughts of death or thoughts of suicide, the number of people who consult family members, professionals, or others is very low. This suggests the importance of community networking through educational activities so that people can more readily talk to and support one another.

Usefulness of endoscopic ultrasonographic analysis of variceal hemodynamics for the treatment of esophageal varices

The correlation of between the endoscopic findings of esophageal varices and endoscopic ultrasound findings of the collaterals outside the esophageal wall in patients with portal hypertension remains unclear. We investigated the relationship between esophageal varices and the collaterals by endoscopy and endoscopic ultrasound. Moreover, we investigated the correlation between the collaterals around the esophagus and recurrence of esophageal varices in patients with portal hypertension who had undergone endoscopic injection sclerotherapy. The collaterals were divided into two groups: 1; those with peri-esophageal collateral veins (peri-ECVs) adjacent to the muscularis externa of the esophagus, and 2; those with para-esophageal collateral veins (para-ECVs) distal to the esophageal wall without contact with the muscularis externa. Peri- and para-ECVs were scored as mild or severe according to the stage of development. According to endoscopy, the varix form was significantly larger in severe peri-ECVs group than in mild peri-ECVs group. In contrast, the varix form did not differ significantly between the mild and severe para-ECVs group. The prevalence of perforating veins increased according to the varix form. With regard to variceal recurrence, in patients with variceal recurrences, EUS findings included a significantly higher incidence of severe-type peri-ECVs, a significantly larger number of perforating veins, and a significantly larger diameter of perforating veins compared with patients without recurrence. Moreover, when EUS found the abnormalities when no endoscopic recurrence was found, the results were the almost same as the findings when EUS was performed at the same time when endoscopic recurrence was found. In conclusion, the presence of severe peri-ECVs and large perforating veins in the esophageal wall strongly correlates with occurrence and recurrence of esophageal varices in patients with portal hypertension. An understanding of these EUS abnormalities on the basis of hemodynamics around the esophagus is thought to be important for management of esophageal varices in patients with portal hypertension.

[Adenomatoid tumor of testicular tunica albuginea: a case report]

Adenomatoid tumors are uncommon neoplasms of the paratesticular tissues. We report a case of an adenomatoid tumor of the testicular tunica albuginea. A 54-year-old man presented with a painless right intrascrotal mass. Serum levels of HCG-beta and AFP were within normal limits. Scrotal ultrasonography showed an oval-shaped low echoic lesion located on the surface of the testis. The patient underwent right partial orchiectomy. Histological examination revealed adenomatoid tumor of the tunica alubuginea testis. Adenomatoid tumors of the testicular tunica alubuginea are rare. Examination of tumor markers, ultrasound studies and diagnoses of frozen sections can prevent needless orchiectomy.

[A case of cardiac myxoma with multiple brain hemorrhage]

A case of cardiac myxoma with multiple brain hemorrhage is reported. A 57-year-old male had complained of lower abdominal pain, diarrhea and fever for 3 days. On admission, he was in a condition of disseminated intravascular coagulation and sepsis. An abdominal CT scan showed infarction in the right kidney and spleen and an echocardiogram also showed myxoma in the left atrium. Although he presented no neurological symptoms, the brain CT showed multiple brain hemorrhage in the bilateral brain hemispheres. Total resection of the tumor was carried out for the improvement of the patient's general condition. Vimentin, S-100 protein and neuron specific enolase was positive in immunological staining and the pathological diagnosis was myxoma. Postoperative recovery of consciousness was poor and left hemiparesis developed. CT showed the increase of hematoma but angiography showed no cerebral aneurysm. The symptoms improved with conservative therapy. However the enhanced lesion remained in the right parietal lobe and an operation was performed 5 months later. The myxoma cell could not be found in the pathological examination, so tumor embolism, cerebral infarction, hemorrhagic infarction due to DIC, hematoma enlargement caused by heparinization during operation were suspected to have occurred in this order without tumor growth.

Carboxyl proteinase from Pseudomonas defines a novel family of subtilisin-like enzymes

The crystal structure of a pepstatin-insensitive carboxyl proteinase from Pseudomonas sp. 101 (PSCP) has been solved by single-wavelength anomalous diffraction using the absorption peak of bromide anions. Structures of the uninhibited enzyme and of complexes with an inhibitor that was either covalently or noncovalently bound were refined at 1.0-1.4 A resolution. The structure of PSCP comprises a single compact domain with a diameter of approximately 55 A, consisting of a seven-stranded parallel beta-sheet flanked on both sides by a number of helices. The fold of PSCP is a superset of the subtilisin fold, and the covalently bound inhibitor is linked to the enzyme through a serine residue. Thus, the structure of PSCP defines a novel family of serine-carboxyl proteinases (defined as MEROPS S53) with a unique catalytic triad consisting of Glu 80, Asp 84 and Ser 287.

Cloning and rational mutagenesis of kexstatin I, a potent proteinaceous inhibitor of Kex2 proteinase

Kexstatin I is a potent proteinaceous inhibitor of Kex2 proteinase (EC 3.4.21.61). In the present study we show the molecular cloning, primary structure determination and expression of the gene encoding kexstatin I. We also demonstrate its enhanced activity and specificity for Kex2 proteinase inhibition by rational mutagenesis. The cloned kexstatin I gene encoded a protein of 145 amino acid residues, including the 35-residue signal sequence for secretion. The amino acid sequence showed 52% identity with those of the Streptomyces subtilisin inhibitors (SSIs). Thus kexstatin I is the first SSI-family member that can inhibit Kex2 proteinase. The reactive site of the inhibitor was determined to be -Thr(69)-Lys(70) downward arrowGlu(71)-, where downward arrow indicates the reactive site. Because Kex2 proteinase generally shows the highest affinity for substrates with basic amino acid residues at the P(1) and P(2) sites, conversion of the Thr(69)-Lys(70) segment of the inhibitor into dibasic motifs was expected to result in enhanced inhibitory activities. Thus we constructed kexstatin I mutants, in which the Thr(69)-Lys(70) sequence was replaced by the Thr(69)-Arg(70), Lys(69)-Lys(70) and Lys(69)-Arg(70) sequences using PCR-based mutagenesis, and analysed them kinetically. Among these mutants, the Lys(69)-Arg(70) mutant was the most potent inhibitor. The K(i) for Kex2 proteinase was 3.2x10(-10) M, which was 140-fold lower than that of the inhibitor with the Thr(69)-Lys(70) sequence. Although kexstatin I could also inhibit subtilisin, the enhancement of inhibitory activity upon such mutations was specific for Kex2 proteinase inhibition.

[A case of arteriovenous malformation associated with venous malformation]

A case of arteriovenous malformation associated with venous malformation is reported. A 35-year-old male patient suffered intracerebral hemorrhage in the left occipital with acute subdural hematoma. Angiography showed an arteriovenous malformation fed by the left middle cerebral artery. The hematoma and nidus was operatively removed. He also had a venous malformation in the left temporal lobe. This rare case is reported with some discussion.