A PTHrP Gradient Drives Mandibular Condylar Chondrogenesis via Runx2

The mandibular condylar cartilage (MCC) is an essential component of the temporomandibular joint, which orchestrates the vertical growth of the mandibular ramus through endochondral ossification with distinctive modes of cell differentiation. Parathyroid hormone-related protein (PTHrP) is a master regulator of chondrogenesis; in the long bone epiphyseal growth plate, PTHrP expressed by resting zone chondrocytes promotes chondrocyte proliferation in the adjacent layer. However, how PTHrP regulates chondrogenesis in the MCC remains largely unclear. In this study, we used a Pthrp-mCherry knock-in reporter strain to map the localization of PTHrP+ cells in the MCC and define the function of PTHrP in the growing mandibular condyle. In the postnatal MCC of PthrpmCherry/+ mice, PTHrP-mCherry was specifically expressed by cells in the superficial layer immediately adjacent to RUNX2-expressing cells in the polymorphic layer. PTHrP ligands diffused across the polymorphic and chondrocyte layers where its cognate receptor PTH1R was abundantly expressed. We further analyzed the mandibular condyle of PthrpmCherry/mCherry mice lacking functional PTHrP protein (PTHrP-KO). At embryonic day (E) 18.5, the condylar process and MCC were significantly truncated in the PTHrP-KO mandible, which was associated with a significant reduction in cell proliferation across the polymorphic layer and a loss of SOX9+ cells in the chondrocyte layers. The PTHrP-KO MCC showed a transient increase in the number of Col10a1+ hypertrophic chondrocytes at E15.5, followed by a significant loss of these cells at E18.5, indicating that superficial layer-derived PTHrP prevents premature chondrocyte exhaustion in the MCC. The expression of Runx2, but not Sp7, was significantly reduced in the polymorphic layer of the PTHrP-KO MCC. Therefore, PTHrP released from cells in the superficial layer directly acts on cells in the polymorphic layer to promote proliferation of chondrocyte precursor cells and prevent their premature differentiation by maintaining Runx2 expression, revealing a unique PTHrP gradient-directed mechanism that regulates MCC chondrogenesis.

Efficient NMR measurement and data analysis supported by the Bayesian inference: The case of the heavy fermion compound YbCo2Zn20

We propose a data-driven technique to infer microscopic physical quantities from nuclear magnetic resonance (NMR) spectra, in which the data size and quality required for the Bayesian inference are investigated. The 59Co-NMR measurement of YbCo2Zn20 single crystal generates complex spectra with 28 peaks. By exploiting the site symmetry in the crystal structure, the isotropic Knight shift Kiso and nuclear quadrupole resonance (NQR) frequency νQ were respectively estimated to be Kiso=0.7822±0.0090% and νQ=2.008±0.016 MHz (T=20 K and H≃10.2 T) by analyzing only 30 data points from one spectrum. The estimated νQ is consistent with the precise value obtained in the NQR experiment. Our method can significantly reduce the measurement time and the computational cost of data analysis in NMR experiments.

Comparison of 22-gauge standard and Franseen needles in EUS-guided tissue acquisition for diagnosing solid pancreatic lesions: a multicenter randomized controlled trial

BACKGROUND AND AIMS

This large multicenter randomized controlled trial compared the diagnostic yields of 22-gauge standard and 22-gauge Franseen needles for EUS-guided tissue acquisition (EUS-TA) of solid pancreatic lesions.

METHODS

Consecutive patients with solid pancreatic lesions were prospectively randomized to EUS-TA using standard or Franseen needles. Samples obtained with the first needle pass and with second and subsequent passes were evaluated separately. The primary endpoint was the rate of accuracy for diagnosis of malignancy. Other endpoints were technical success rate, sample cellularity, adverse events, diagnostic accuracy in patient subgroups, and the diagnostic accuracy and numbers of second and subsequent needle passes.

RESULTS

Of 523 patients undergoing EUS-TA, 260 were randomized to using standard 22-gauge needles and 263 to 22-gauge Franseen needles. The technical success rate in each group was 99.6%, with similar adverse event rates in the standard (1.5%) and Franseen (.8%) needle groups. First-pass EUS-TA using the Franseen needle resulted in significantly greater diagnostic accuracy (84.0% vs 71.2%, P < .001) and sensitivity (82.4% vs 66.7%, P < .001) than first-pass EUS-TA using a standard needle and also resulted in superior diagnostic accuracy in patients requiring immunostaining. Second and subsequent EUS-TA using Franseen needles showed significantly greater accuracy (94.7% vs 90.0%, P = .049) and sensitivity (94.0% vs 88.6%, P = .047) and required fewer needle passes (1.81 vs 2.03, P = .008) than using standard needles.

CONCLUSIONS

EUS-TA with the Franseen needle is superior to EUS-TA with a standard needle with respect to diagnostic accuracy per pass, particularly in patients who require immunostaining, and number of passes when using macroscopic on-site evaluation. (Clinical trial registration numbers: UMIN000030634 and jRCTs052180062.).

Emergency Endoscopic Retrograde Cholangiopancreatography Did Not Increase the Incidence of Postprocedural Pancreatitis Compared With Elective Cases: A Prospective Multicenter Observational Study

OBJECTIVE

The aim of this study was to identify the incidence of and risk factors for post-endoscopic retrograde cholangiopancreatography pancreatitis (PEP) after emergency endoscopic retrograde cholangiopancreatography (ERCP).

METHODS

We performed a prospective multicenter observational study of 3914 patients who underwent ERCP. We compared the incidence of PEP after emergency and elective ERCP.

RESULTS

A total of 3410 patients were enrolled in this study. Post-ERCP pancreatitis occurred in 44 of 800 patients (5.5%) and in 190 of 2418 patients (7.9%) in the emergency and elective groups, respectively. No significant difference was noted between the groups (odds ratio [OR], 0.73; 95% confidence interval [CI], 0.52-1.03; P = 0.07). Multivariate analysis showed that the following factors increased the risk for PEP after emergency ERCP: contrast medium injection into the pancreatic duct (OR, 2.56; 95% CI, 1.30-5.03; P = 0.005), >4 cannulation attempts (OR, 5.72; 95% CI, 2.61-12.50; P < 0.001), and endoscopic papillary balloon dilatation (OR, 9.24; 95% CI, 2.13-40.10; P < 0.001).

CONCLUSIONS

No significant difference was noted in the incidence of PEP in patients after emergency and elective ERCP. We may prevent PEP even after emergency ERCP by avoiding contrast injection into the pancreatic duct, multiple cannulation attempts, and endoscopic papillary balloon dilatation.

Post-endoscopic retrograde cholangiopancreatography pancreatitis assessed using criteria for acute pancreatitis

Background and Aim

International consensus on the definition and classification of post-endoscopic retrograde cholangiopancreatography (ERCP) pancreatitis (PEP) has been reached. However, the diagnosis and severity of PEP are often assessed according to the diagnostic criteria and classification for acute pancreatitis (AP). This study determined the incidence, severity, and risk factors of PEP diagnosed according to the diagnostic criteria and classification for AP in a large cohort.

Methods

This prospective, multicenter, observational cohort study conducted at five high-volume centers included 1932 patients who underwent ERCP-related procedures. The incidence, severity, and risk factors for PEP were evaluated.

Results

PEP occurred in 142 patients (7.3%); it was mild in 117 patients (6.0%) and severe in 25 patients (1.3%). According to the Cotton criteria, PEP occurred in 87 patients (4.5%); it was mild in 54 patients (2.8%), moderate in 20 patients (1.0%), and severe in 13 patients (0.7%). In the multivariate analysis, female sex (odds ratio [OR] 2.239; 95% confidence interval [CI] 1.546-3.243), naïve papilla (OR 3.047; 95% CI 1.803-5.150), surgically-altered gastrointestinal anatomy (OR 2.538; 95% CI 1.342-4.802), procedure time after reaching the papilla (OR 1.009; 95% CI 1.001-1.017), pancreatic duct injection (OR 2.396; 95% CI 1.565-3.669), and intraductal ultrasonography (OR 1.641; 95% CI 1.024-2.629) were independent risk factors.

Conclusion

According to the diagnostic criteria and classification for AP, the incidence of PEP was higher than that according to the Cotton criteria and the severity of PEP tended to be severe.

Anti-PD-1 antibody monotherapy versus anti-PD-1 plus anti-CTLA-4 combination therapy as first-line immunotherapy in unresectable or metastatic mucosal melanoma: a retrospective, multicenter study of 329 Japanese cases (JMAC study)

Background

Anti-programmed cell death protein 1 (PD-1) antibody monotherapy (PD1) has led to favorable responses in advanced non-acral cutaneous melanoma among Caucasian populations; however, recent studies suggest that this therapy has limited efficacy in mucosal melanoma (MCM). Thus, advanced MCM patients are candidates for PD1 plus anti-cytotoxic T lymphocyte-associated antigen-4 (CTLA-4) combination therapy (PD1 + CTLA4). Data on the efficacy of immunotherapy in MCM, however, are limited. We aimed to compare the efficacies of PD1 and PD1 + CTLA4 in Japanese advanced MCM patients.

Patients and methods

We retrospectively assessed advanced MCM patients treated with PD1 or PD1 + CTLA4 at 24 Japanese institutions. Patient baseline characteristics, clinical responses (RECIST), progression-free survival (PFS), and overall survival (OS) were estimated using Kaplan–Meier analysis, and toxicity was assessed to estimate the efficacy and safety of PD1 and PD1 + CTLA4.

Results

Altogether, 329 patients with advanced MCM were included in this study. PD1 and PD1 + CTLA4 were used in 263 and 66 patients, respectively. Baseline characteristics were similar between both treatment groups, except for age (median age 71 versus 65 years; P < 0.001). No significant differences were observed between the PD1 and PD1 + CTLA4 groups with respect to objective response rate (26% versus 29%; P = 0.26) or PFS and OS (median PFS 5.9 months versus 6.8 months; P = 0.55, median OS 20.4 months versus 20.1 months; P = 0.55). Cox multivariate survival analysis revealed that PD1 + CTLA4 did not prolong PFS and OS (PFS: hazard ratio 0.83, 95% confidence interval 0.58-1.19, P = 0.30; OS: HR 0.89, 95% confidence interval 0.57-1.38, P = 0.59). The rate of ≥grade 3 immune-related adverse events was higher in the PD1 + CTLA4 group than in the PD1 group (53% versus 17%; P < 0.001).

Conclusions

First-line PD1 + CTLA4 demonstrated comparable clinical efficacy to PD1 in Japanese MCM patients, but with a higher rate of immune-related adverse events.

•

Anti-PD-1 plus anti-CTLA-4 antibody therapy (PD1 + CTLA4) is an option for patients with advanced mucosal melanoma (MCM).

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Data on the efficacy of PD1 + CTLA4 compared with PD-1 monotherapy (PD1) for MCM, however, are limited.

•

We retrospectively analyzed data from 329 Japanese patients with advanced MCM treated with PD1 or PD1 + CTLA4.

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No significant differences in objective response rate, progression-free survival, or overall survival were observed.

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Immune-related adverse events resulting in treatment cessation were higher in the PD1 + CTLA4 group.

Endoscopic placement of covered versus uncovered self-expandable metal stents for palliation of malignant gastric outlet obstruction

OBJECTIVE

Stenting is an established endoscopic therapy for malignant gastric outlet obstruction (mGOO). The choice of stent (covered vs uncovered) has been examined in prior randomised studies without clear results.

DESIGN

In a multicentre randomised prospective study, we compared covered (CSEMS) with uncovered self-expandable metal stents (UCSEMS) in patients with mGOO; main outcomes were stent dysfunction and patient survival, with subgroup analyses of patients with extrinsic and intrinsic tumours.

RESULTS

Overall survival was poor with no difference between groups (probability at 3 months 49.7% for covered vs 48.4% for uncovered stents; log-rank for overall survival p=0.26). Within that setting of short survival, the proportion of stent dysfunction was significantly higher for uncovered stents (35.2% vs 23.4%, p=0.01) with significantly shorter time to stent dysfunction. This was mainly relevant for patients with extrinsic tumours (stent dysfunction rates for uncovered stents 35.6% vs 17.5%, p<0.01). Subgrouping was also relevant with respect to tumour ingrowth (lower with covered stents for intrinsic tumours; 1.6% vs 27.7%, p<0.01) and stent migration (higher with covered stents for extrinsic tumours: 15.3% vs 2.5%, p<0.01).

CONCLUSIONS

Due to poor patient survival, minor differences between covered and uncovered stents may be less relevant even if statistically significant; however, subgroup analysis would suggest to use covered stents for intrinsic and uncovered stents for extrinsic malignancies.

Reducing the risk of developing walled-off necrosis in patients with acute necrotic collection using recombinant human soluble thrombomodulin

BACKGROUND/PURPOSE

The purpose of the present study was to investigate the possibility of reducing clinical impacts of acute necrotic collection (ANC) on patients with acute pancreatitis (AP) using recombinant human soluble thrombomodulin (rTM).

METHODS

In this retrospective multicenter study, 233 consecutive AP patients with ANC and acute peripancreatic fluid collection (APFC) from 2012 to 2016 were enrolled. To assess clinical impacts of ANC, severity on admission (JPN score, JPN CT grade, and Modified CT severity index), development of walled-off necrosis (WON), imaging costs for follow-up, and mortality were recorded. Finally, we investigated whether rTM could reduce the clinical impacts, adjusting the severity using propensity analysis with Inverse probability of treatment weighting.

RESULTS

Patients with ANC developed WON with higher ratio than APFC (58/98 [59.2%] vs 20/135 [14.8%], OR = 8.3, P < .01]. Severity on admission and imaging costs for follow-up in ANC patients were significantly higher than those in APFC (P < .01). However, regarding mortality, there was no significant difference between patients with ANC and APFC (P = .41). Adjusting severity, it was revealed that rTM administration significantly reduced the risk of ANC developed WON (OR = 0.23, P = .01).

CONCLUSIONS

While ANC had a higher clinical impact than that of APFC, we found that early administration of rTM may reduce the impact.

[A case of concomitant pancreatic neuroendocrine neoplasm and intraductal papillary mucinous neoplasm in which preoperative diagnosis was difficult]

A 75-year-old male patient has been followed-up for mixed-type intraductal papillary mucinous neoplasm (IPMN) in the tail of the pancreas for about 20 years. Upon close examination, he was diagnosed of high-risk stigmata due to a nodule having a contrast effect of 5mm or more in the tumor. Based on this, a distal pancreatectomy was performed. Histopathological analysis revealed concomitant IPMN (low-grade) and pancreatic neuroendocrine neoplasm (PNEN) (G1). This prompted us to report a very rare case of coexisting PNEN and IPMN with an interesting pathological finding that might suggest its pathogenic mechanism.

[Prediction of pancreatitis following endoscopic retrograde cholangiopancreatography]

OBJECTIVE

The aim of this study was to determine if the difference in serum amylase levels prior to, and two hours following, an endoscopic retrograde cholangiopancreatography (ERCP), or the ratio of the two-hour post-ERCP amylase level to the pre-ERCP amylase level was a better predictor of post-ERCP pancreatitis (PEP).

METHODS

This was a retrospective, single-center study of consecutive patients, who underwent ERCP between April 2015 and August 2018. Serum amylase was measured before and two hours following ERCP. We compared the difference and the ratio of the two levels in predicting PEP using a receiver operating characteristic (ROC) curve analysis.

RESULTS

A total of 1029 patients underwent ERCP, with PEP occurring in 118 (11.5%). Multivariate analysis revealed that an elevated two-hour post-ERCP serum amylase level was a significant predictor of PEP. ROC analysis of the difference and the ratio of the two levels found good performance for both parameters, with an area under the curve (AUC) of 0.861 (95% confidence interval [CI], 0.823-0.900) and 0.847 (95% CI, 0.809-0.886), respectively. The difference between the values was a significantly more effective predictor of PEP, based on the AUC analysis (P = 0.011).

CONCLUSION

The difference between pre and two-hour post-ERCP amylase levels is a better predictor of PEP than the ratio of the two.

[Vitamin K deficiency caused by nutritional malabsorption accompanying afferent loop obstruction:a case report]

This case involves a 73-year-old man who visited a clinic because he was experiencing dyspnea on exertion and acid reflux. He was diagnosed with anemia and referred for a medical check-up and treatment by his primary care physician. Iron deficiency anemia and prolonged prothrombin time were confirmed with a blood test and an abdominal enhanced CT revealed marked expansion of the afferent loop after a gastrectomy. The medical check-up revealed abnormal blood coagulation due to afferent loop obstruction, which resulted in vitamin K deficiency. He was supplemented with vitamin K, and surgery was performed for the afferent loop obstruction. Postoperatively, his anemia, nutritional status, serum vitamin K levels, and prothrombin time improved steadily. In conclusion, nutrient malabsorption may occur in cases of afferent loop obstruction and abnormal blood coagulation due to vitamin K deficiency.

[Successful biliary drainage by percutaneous transhepatic puncture common bile duct and rendezvous technique for a case of recurrent biliary pancreatitis with a Roux-en-Y reconstruction and without extension of the bile duct]

A 92-year-old woman was hospitalized with upper abdominal pain. She had a history of acute biliary pancreatitis and chronic heart failure and had undergone gastrectomy with Roux-en-Y reconstruction. She was admitted with recurrent pancreatitis and an exacerbation of heart failure. Biliary drainage could not successfully be achieved endoscopically or with percutaneous transhepatic biliary drainage and EUS-guided biliary drainage because of the Roux-en-Y reconstruction and non-dilation of bile duct. We successfully accomplished biliary drainage in one session with percutaneous transhepatic puncture of the common bile duct with ultrasound guidance and the rendezvous technique. We report this case because it is rare.

[A case of relapsed hemosuccus pancreaticus successfully treated with interventional radiology]

A 67-year-old male with chronic pancreatitis presented with upper abdominal pain and melena. Abdominal dynamic computed tomography revealed a splenic artery aneurysm in the main pancreatic duct. Esophagogastroduodenoscopy showed active bleeding from Vater's papilla. The patient was diagnosed with hemosuccus pancreaticus (HP) due to rupture of the aneurysm and treated with interventional radiology (IVR). The patient's poor lung function did not allow for a radical operation and a follow-up examination was recommended. The HP relapsed 7 months later and was successfully retreated with IVR. Although IVR is associated with a high recurrence rate, it is less invasive and therefore effective for treating relapsing HP in patients with a poor general condition.

Phase I/II clinical trial to assess safety and efficacy of intratumoral and subcutaneous injection of HVJ-E in castration-resistant prostate cancer patients

Inactivated Sendai virus particles (hemagglutinating virus of Japan envelope (HVJ-E)) have a novel antitumor effect: HVJ-E fused to prostate cancer cells via cell surface receptor causes apoptosis of prostate cancer cells in vitro and in vivo. HVJ-E also induces antitumor immunity by activating natural killer (NK) cells and cytotoxic T cells and suppressing regulatory T cells in vivo. We conducted an open-label, single-arm, phase I/II clinical trial in patients with castration-resistant prostate cancer (CRPC) to determine the safety and efficacy of intratumoral and subcutaneous injection of HVJ-E. Patients with CRPC who were docetaxel-resistant or could not receive docetaxel treatment were eligible. HVJ-E was injected directly into the prostate on day 1 and subcutaneously on days 5, 8 and 12 in two 28-day treatment cycles using a 3+3 dose-escalation design. The primary end points were to evaluate safety and tolerability of HVJ-E. The secondary end points were to analyze tumor immunity and antitumor effect. The study is registered at UMIN Clinical Trials Registry, number UMIN000006142. Seven patients were enrolled, and six patients received HVJ-E. Grade 2 or 3 adverse events (Common Terminology Criteria for Adverse Events Ver. 4.0) were urinary retention and lymphopenia from which the patients recovered spontaneously. No Grade 4 adverse events were observed. Radiographically, three patients had stable disease in the low-dose group, and one patient had stable disease and two had progressive disease in the high-dose group. The prostate-specific antigen (PSA) declined from 14 to 1.9 ng ml^-1 in one patient in the low-dose group after two cycles of HVJ-E treatment, and the PSA response rate was 16.6%. NK cell activity was elevated from day 12 to day 28 after HVJ-E administration, whereas serum interleukin-6, interferon (IFN)-α, IFN-β and IFN-γ levels were not affected by HVJ-E treatment. Intratumoral and subcutaneous injections of HVJ-E are feasible and PSA response was observed in a subgroup of CRPC patients.

Diagnostic performance of a new endoscopic scraper for malignant biliary strictures: a multicenter prospective study

BACKGROUND AND AIMS

The efficacy of ERCP for histologic diagnosis of malignant biliary strictures is disappointingly low. The aim of this study was to investigate the diagnostic performance of a newly developed endoscopic device with scraping loops in combination with conventional biopsy forceps.

METHODS

We performed a multicenter single-arm prospective study. Between February 2013 and December 2014, 123 patients with suspected malignant biliary strictures were enrolled in the study. The new device and conventional biopsy forceps were applied for histologic diagnosis by ERCP. The primary outcome was to evaluate cancer detectability by biopsy forceps, the new device, and their combined use.

RESULTS

Of the 123 patients, 119 were diagnosed with a malignant stricture. Sufficient samples were collected in 83.7% (103/123), 93.5% (115/123), and 95.9% (118/123) of patients using biopsy forceps, the new device, and their combination, respectively. Cancer detectability of forceps biopsy, the new device, and their combination were 51.3% (61/119), 64.7% (77/119), and 74.8% (89/119), respectively. The new device had a significantly higher sample yield and cancer detectability than biopsy forceps (P < .01 and P = .018, respectively, McNemar test). Complementary use of the new device with biopsy forceps demonstrated a significantly additive effect in both sample yield and cancer detection (P < .01 each, McNemar test). The new device detected 48.3% (28/58) of cancers that were not diagnosed as malignant by biopsy forceps.

CONCLUSIONS

The new endoscopic scraper demonstrated a large sample yield and high cancer detectability. It could be a first-line tissue-sampling device for biliary strictures. (University Hospital Medical Information Network Clinical Trial Registry [UMIN-CTR] (http://www.umin.ac.jp/ctr/index.htm) registration number: UMIN000009895.).

Morphological and Immunohistochemical Features of Cryptosporidium andersoni in Cattle

Light and electron microscopic features and immunohistochemical features of Cryptosporidium andersoni ( C. andersoni) and host reaction in the mucosa were studied. Although the affected cattle demonstrated no apparent clinical signs, a severe infection of C. andersoni was observed in the abomasum. C. andersoni were round in shape, measured 6-8 μm in size and were mainly observed to be freely located in the gastric pits, being attached in occasional cases to the surface of the abomasum epithelium. Frequent inflammatory cells had infiltrated the lamina propria of the affected mucosa, and frequent mitotic figures were observed in epithelial cells at the dilated isthmus. To access the cell kinetics, the number of epithelial cells infected with C. andersoni were counted and compared with noninfected cattle. The number of gastric pit cells in infected cattle was significantly higher than that in the controls. The number of proliferative cells determined by the Ki-67 antigen in C. andersoni infected cattle was also significantly higher than that in the controls. Transmission electron microscopy and scanning electron microscopy revealed that the morphology of the C. andersoni organism was common to those of other Cryptosporidium spp. immunohistochemically, several commercial antibodies against Cryptosporidium spp. showed positive reactions at the wall of these oocysts or parasitophorous vacuoles. This report is possibly the first to discuss the prominent hyperplasia of the abomasum mucosa, as well as morphologic features of C. andersoni in cattle.

Magnifying narrow-band imaging with acetic acid to diagnose early colorectal cancer

AIM: To evaluate the diagnostic characteristics of magnifying endoscopy with acetic acid spray and narrow-band imaging (MA-NBI) for early colorectal cancer.

METHODS: We conducted a prospective study to evaluate the diagnostic characteristics of MA-NBI in differentiating early colorectal adenocarcinomas from adenomas. To compare the results, we used magnifying endoscopy with NBI (M-NBI) and magnifying endoscopy with crystal violet staining (M-CV). The study was performed in 2 phases. In phase 1, 10 colonoscopists at our institution were shown still photographs of 35 colorectal polyps (24 adenocarcinomas and 11 adenomas) in M-NBI, MA-NBI, and M-CV. They made diagnostic predictions using a five-grade scoring evaluation. We plotted receiver operating characteristic curves and compared the areas under the curves (AUCs). In phase 2, colorectal polyps measuring ≥ 8 mm were prospectively enrolled. During real-time colonoscopy, one of the 7 colonoscopists scored the lesion as an adenocarcinoma or an adenoma and assigned a level of confidence to the prediction (high or low). We calculated the accuracy, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for each method and compared the proportions of high-confidence predictions.

RESULTS: In phase 1, the mean ± SD AUCs were 0.64 ± 0.031 in M-NBI, 0.71 ± 0.066 in MA-NBI, and 0.76 ± 0.059 in M-CV (P < 0.05 for M-NBI vs MA-NBI, P < 0.001 for M-NBI vs M-CV, and not significant for MA-NBI vs M-CV). In phase 2, 84 patients with 91 lesions (46 adenocarcinomas and 45 adenomas) were enrolled. The diagnostic characteristics were as follows: 73% accuracy, 85% sensitivity, 60% specificity, 68% PPV, and 79% NPV in M-NBI; 73% accuracy, 80% sensitivity, 64% specificity, 70% PPV, and 76% NPV in MA-NBI; and 73% accuracy, 83% sensitivity, 62% specificity, 69% PPV, and 78% NPV in M-CV. The proportions of high-confidence predictions were 57% in M-NBI, 75% in MA-NBI, and 76% in M-CV (P < 0.005 for M-NBI vs MA-NBI, P < 0.0005 for M-NBI vs M-CV, and P = 1.0 for MA-NBI vs M-CV).

CONCLUSION: MA-NBI is useful for differentiating early colorectal adenocarcinomas from adenomas.

Effectiveness of a simulated patient training programme based on trainee response accuracy and appropriateness of feedback

INTRODUCTION

Simulated patients (SPs) need education and training in required skills to be effective resources in education. This study was conducted to examine the effectiveness of an SP training programme based on the accuracy of trainee responses and the appropriateness of their feedback.

METHODS

Thirty-two applicants to the training programme and 35 experienced SPs were included in this study. The experienced SPs served as a reference group. The rate of accurate responses and the rate of appropriate feedback were assessed with pre- and post-training tests, and these two outcome measures were compared with those of the experienced SPs.

RESULTS

No significant differences were found in trainee response accuracy or appropriateness of feedback between pre- and post-training tests. The response accuracy rate of the trainees on the pre-training test was significantly lower than that of SPs with 1-2 years of experience, whilst there was no significant difference between these SPs and the trainees on the post-training test.

CONCLUSIONS

Although our study suggests that more training is needed to improve the skills of SPs, the training programme may contribute to helping trainees reach a novice level in the skill of providing accurate responses. SP training should be encouraged to contribute to the effectiveness of such teaching and to establish the validity of the assessment.

[A patient with sepsis and a gas-forming liver abscess caused by Clostridium perfringens treated with continuous perfusion drainage]

A 64-year-old man presented with diarrhea, fever, and disturbance of consciousness; he was subsequently diagnosed with acute renal and hepatic disorder. Abdominal computed tomography identified a gas-forming liver abscess, and the patient underwent emergency drainage. However, his condition did not improve, and Clostridium perfringens was observed in his blood culture. Continuous perfusion drainage was performed by placing an additional drainage tube, which resulted in abscess shrinkage and improved the patient's general condition. Despite the low survival rate in patients with gas-forming liver abscesses caused by C. perfringens, therapy was successful in this patient.

Prognostic nomogram for nonresectable pancreatic cancer treated with gemcitabine-based chemotherapy

Background:

A nomogram is progressively being used as a useful predictive tool for cancer prognosis. A nomogram to predict survival in nonresectable pancreatic cancer treated with chemotherapy has not been reported.

Methods:

Using prospectively collected data on patients with nonresectable pancreatic cancer receiving gemcitabine-based chemotherapy at five Japanese hospitals, we derived a predictive nomogram and internally validated it using a concordance index and calibration plots.

Results:

In total, 531 patients were included between June 2001 and February 2013. The American Joint Committee on Cancer (AJCC) TNM stages were III and IV in 204 and 327 patients, respectively. The median survival time of the total cohort was 11.3 months. A nomogram was generated to predict survival probabilities at 6, 12, and 18 months and median survival time, based on the following six variables: age; sex; performance status; tumour size; regional lymph node metastasis; and distant metastasis. The concordance index of the present nomogram was higher than that of the AJCC TNM staging system at 12 months (0.686 vs 0.612). The calibration plots demonstrated good fitness of the nomogram for survival prediction.

Conclusions:

The present nomogram can provide valuable information for tailored decision-making early after the diagnosis of nonresectable pancreatic cancer.

Multi-charged heavy ion acceleration from the ultra-intense short pulse laser system interacting with the metal target

Experimental demonstration of multi-charged heavy ion acceleration from the interaction between the ultra-intense short pulse laser system and the metal target is presented. Al ions are accelerated up to 12 MeV/u (324 MeV total energy). To our knowledge, this is far the highest energy ever reported for the case of acceleration of the heavy ions produced by the <10 J laser energy of 200 TW class Ti:sapphire laser system. Adding to that, thanks to the extraordinary high intensity laser field of ∼10(21) W cm(-2), the accelerated ions are almost fully stripped, having high charge to mass ratio (Q/M).

Measurements of electron-induced neutrons as a tool for determination of electron temperature of fast electrons in the task of optimization laser-produced plasma ions acceleration

High intensity laser-plasma interaction has attracted considerable interest for a number of years. The laser-plasma interaction is accompanied by generation of various charged particle beams, such as high-energy proton and ions with high charge to mass ratio (Q/M; same as multi-charged ions). Results of simultaneous novel measurements of electron-induced photonuclear neutrons (photoneutron), which are a diagnostic of the laser-plasma interaction, are proposed to use for optimization of the laser-plasma ion generation. The proposed method is demonstrated by the laser irradiation with the intensity of 1 × 10(21) W/cm(2) on the metal foil target. The photoneutrons are measured by using NE213 liquid scintillation detectors. Heavy-ion signal is registered with the CR-39 track detector simultaneously. The measured signals of the electron-induced photoneutrons are well reproduced by using the Particle and Heavy Ion Transport code System. The results obtained provide useful approach for analyzing the various laser based ion beams.

Covered self-expandable metal stents with an anti-migration system improve patency duration without increased complications compared with uncovered stents for distal biliary obstruction caused by pancreatic carcinoma: a randomized multicenter trial

OBJECTIVES

The requirements of biliary stents used in the palliation of malignant biliary obstruction are a long duration of patency and minimal adverse effects. Covered self-expandable metal stents (SEMSs) have been shown to prevent tumor ingrowth, which is the most frequent complication of uncovered SEMSs. However, because they are prone to migration, the superiority of covered SEMS has yet to be convincingly demonstrated. The aim of this study was to evaluate the superiority of covered over uncovered SEMSs in the palliation of distal biliary obstruction due to unresectable pancreatic carcinoma, using both stent types with relatively low axial force and uncovered flared ends to prevent their migration.

METHODS

From April 2009 to December 2010, 120 patients who were admitted to 22 tertiary-care centers because of distal biliary obstruction from unresectable pancreatic carcinomas were enrolled in this prospective randomized multicenter study. Patients were randomly assigned to receive a covered or uncovered SEMS deployed at the site of the biliary stricture during endoscopic retrograde cholangiopancreatography. Stent patency time, patient survival time, patient survival time without stent dysfunction (time to stent dysfunction or patient death), cause of stent dysfunction (ingrowth, overgrowth, migration, or sludge formation), and serious adverse events were compared between covered and uncovered SEMS groups.

RESULTS

Patient survival time in the two groups did not significantly differ (median: 285 and 223 days, respectively; P=0.68). Patient survival time without stent dysfunction was significantly longer in the covered than in the uncovered SEMS group (median: 187 vs. 132 days; P=0.043). Stent patency was also significantly longer in the covered than in the uncovered SEMS group (mean±s.d.: 219.3±159.1 vs. 166.9±124.9 days; P=0.047). Reintervention for stent dysfunction was performed in 14 of 60 patients with covered SEMSs (23%) and in 22 of 60 patients with uncovered SEMSs (37%; P=0.08). Stent dysfunction was caused by tumor ingrowth, tumor overgrowth, and sludge formation in 0 (0%), 3 (5%), and 11 (18%) patients in the covered SEMSs group, and in 15 (25%), 2 (3%), and 6 (10%) patients in the uncovered SEMSs group, respectively. Stent migration was not observed in either group. Rates of tumor overgrowth and sludge formation did not significantly differ between the two groups, whereas the rate of tumor ingrowth was significantly lower in the covered than in the uncovered SEMS group (P<0.01). Acute pancreatitis occurred in only one patient in the covered SEMS group. Acute cholecystitis occurred in one patient in the covered SEMS group and in two patients in the uncovered SEMS group. There was no significant difference between the two groups in the incidence of serious adverse events.

CONCLUSIONS

By preventing tumor ingrowth and migration, covered SEMSs with an anti-migration system had a longer duration of patency than uncovered SEMSs, which recommends their use in the palliative treatment of patients with biliary obstruction due to pancreatic carcinomas.