Manipulating the functionality and structures of π-conjugated polymers utilizing intramolecular noncovalent interactions towards efficient organic photovoltaics.

Careful control of electronic properties, structural order, and solubility of π-conjugated polymers is central to the improvement of organic photovoltaic (OPV) performance. In this work, we designed and synthesized a series of naphthobisthiadiazole-quaterthiophene copolymers by systematically replacing the alkyl groups with ester groups and changing the position of the fluorine groups in the quaterthiophene moiety. These alterations lowered the HOMO and LUMO energy levels and systematically varied the combination of intramolecular noncovalent interactions such as O⋯S and F⋯S interactions in the backbone. More importantly, although the introduction of such noncovalent interactions often lowers the solubility owing to the interlocking of backbone linkages, we found that careful design of the noncovalent interactions afforded polymers with relatively high solubility and high crystallinity at the same time. As a result, the power conversion efficiency of OPV cells that used fullerene (PC61BM) and nonfullerene (Y12) as the acceptor was improved. Our work offers important information for the development of high-performance π-conjugated polymers for OPVs.

Temporal progression of pancreatic cancer computed tomography findings until diagnosis: A large-scale multicenter study.

BACKGROUND: Focal parenchymal atrophy and main pancreatic duct (MPD) dilatation have been identified as early signs of pancreatic ductal adenocarcinoma. However, limited evidence exists regarding their temporal progression due to previous study limitations with restricted case numbers. OBJECTIVE: To ascertain a more precise frequency assessment of suspicious pancreatic ductal adenocarcinoma findings as well as delineate the temporal progression of them. METHODS: A multicenter retrospective study was conducted on patients diagnosed with pancreatic ductal adenocarcinoma between 2015 and 2021. We included patients who had undergone at least one computed tomography (CT) scan ≥6 months before diagnosing pancreatic ductal adenocarcinoma. The temporal progression of suspicious pancreatic ductal adenocarcinoma findings on CT was investigated. RESULTS: Out of 1832 patients diagnosed with pancreatic ductal adenocarcinoma, 320 had a previous CT before their diagnosis. Suspicious pancreatic ductal adenocarcinoma findings were detected in 153 cases (47.8%), with focal parenchymal atrophy (26.6%) being the most common followed by MPD dilatation (11.3%). Focal parenchymal atrophy was the earliest detectable sign among all suspicious findings and became visible on average 2.7 years before diagnosis, and the next most common, MPD dilatation, 1.1 years before diagnosis. Other findings, such as retention cysts, were less frequent and appeared around 1 year before diagnosis. Focal parenchymal atrophy followed by MPD dilatation was observed in 10 patients but not in reverse order. Focal parenchymal atrophy was more frequently detected in the pancreatic body/tail. No significant relationship was found between the pathological pancreatic ductal adenocarcinoma differentiation or tumor stage and the time course of the CT findings. All cases of focal parenchymal atrophy progressed just prior to diagnosis, and the atrophic area was occupied by tumor at diagnosis. Main pancreatic duct dilatation continued to progress until diagnosis. CONCLUSION: This large-scale study revealed that the temporal progression of focal parenchymal atrophy is the earliest detectable sign indicating pancreatic ductal adenocarcinoma. These results provide crucial insights for early pancreatic ductal adenocarcinoma detection.

Pancreatic injury in patients treated with immune checkpoint inhibitors: a retrospective multicenterstudy.

BACKGROUND: Immune checkpoint inhibitor-related pancreatic injury (ICI-PI) is a rare occurrence, which has not been reported in detail. We conducted a retrospective multicenter study to determine the clinical characteristics, risk factors, and treatment of ICI-PI. METHODS: We reviewed the medical records of patients who received ICIs for malignant tumors between April 2014 and April 2019 at 16 participating hospitals. Patients with elevated pancreatic enzymes or pancreatitis were identified and classified using the Common terminology Criteria for Adverse Events (CTCAE) ver.5.0). The number of patients with pancreatic enzyme elevation was determined and those with pancreatic enzyme elevation of ≥ grade 3 according to CTCAE ver.5.0, or pancreatitis underwent detailed analysis for ICI-PI. RESULTS: The study enrolled 1069 patients. Nineteen patients (1.8%) had ICI-PI, 5 (0.5%) of whom also had pancreatitis. Four patients had mild pancreatitis, whereas 1 patient had severe pancreatitis, culminating in death. Steroid therapy was administered to 7 of 19 patients, which led to ICI-PI improvement in 5 patients. On the other hand, ICI-PI improved in 9 of 12 patients who were not administered steroid therapy. Six of the 14 patients with ICI-PI improvement were rechallenged with ICI, and ICI-PI relapse occurred in only 1 patient (16.7%), which improved with ICI discontinuation and steroid therapy. CONCLUSIONS: ICI-PI is a rare occurrence, with a low incidence of pancreatitis, which followed a very serious course in one patient. Although the benefit of steroid therapy for ICI-PI is unclear, ICI rechallenge is acceptable after improvement of ICI-PI without pancreatitis.

Relapse and side effects of steroid therapy beyond 3 years in autoimmune pancreatitis: A multicenter retrospective study.

BACKGROUND: The impact of extended steroid administration on patients with autoimmune pancreatitis after a 3-year maintenance period remains poorly understood. This study analyzed the advantage and disadvantage of continuing steroid therapy beyond 3 years. METHODS: In this retrospective multicenter study across 17 institutions, patients who successfully completed 3 years of maintenance therapy without experiencing relapse were categorized into two groups: the maintenance therapy discontinuation group, who discontinued steroid therapy after the initial 3-year period, and maintenance therapy continuation group, who continued steroid therapy beyond 3 years. The cumulative relapse rate after 3 years of maintenance therapy was the primary outcome. Relapse predictors were compared using the Gray test for cumulative relapse incidence by specific factor. RESULTS: Of 211 patients, 105 experienced no relapse during the 3-year maintenance therapy and were divided into two groups: 69 in the maintenance therapy discontinuation group and 36 in the maintenance therapy continuation group. The relapse rate was lower in the maintenance therapy continuation group than in the maintenance therapy discontinuation group (P = 0.035). Predictors of relapse after 3 years included cessation of maintenance therapy (hazard ratio [HR] = 3.76; 95 % confidence interval [CI] = 1.07-13.3, P = 0.040) and renal involvement (HR = 2.88; 95 % CI = 1.04-7.99, P = 0.042). The maintenance therapy continuation group showed a significantly higher prevalence of macrovascular complications, compared with the maintenance therapy discontinuation group (P = 0.005). CONCLUSIONS: Cessation of steroid maintenance therapy and renal involvement were predictors of relapse after 3 years of maintenance therapy. However, the long-term use of steroids may increase the risk of macrovascular complications.

Simple π-Conjugated Polymers Based on Bithiazole for Nonfullerene Organic Photovoltaics.

Thiazole, as a family of five-membered heteroaromatic rings, is an interesting building unit that can play a role in coplanarizing the backbone as well as deepening the HOMO energy level, which is beneficial for the design of π-conjugated polymers for the photoactive materials in organic photovoltaics (OPVs). Here, we designed and synthesized π-conjugated polymers with simple chemical structures, which consist of 2,2'-bithiazole or 5,5'-bithiazole and alkylthiophenes as the polymer backbone. In fact, the polymers can be easily synthesized in much fewer steps compared to the typical high-performance polymers based on fused heteroaromatic rings. Interestingly, PTN5 exhibited a markedly higher ordered structure than PTN2. This was likely ascribed to the more coplanar and rigid backbone of PTN5 than that of PTN2 originating in the effectively arranged S···N interaction. As a result, the nonfullerene photovoltaic cell based on PTN5 showed a PCE of 12.2%, which was much higher than the cell based on PTN2 (4.3%) and was high for the polymers consisting of only nonfused rings. These results demonstrate that thiazole-based polymers are promising photoactive materials for OPVs and emphasize the importance of careful molecular design utilizing noncovalent interactions.

A novel fully covered metal stent for unresectable malignant distal biliary obstruction: results of a multicenter prospective study.

Background/Aims: Endoscopic self-expandable metal stent (SEMS) placement is currently the standard technique for treating unresectable malignant distal biliary obstructions (MDBO). Therefore, covered SEMS with longer stent patency and fewer migrations are required. This study aimed to assess the clinical performance of a novel, fully covered SEMS for unresectable MDBO. Methods: This was a multicenter single-arm prospective study. The primary outcome was a non-obstruction rate at 6 months. The secondary outcomes were overall survival (OS), recurrent biliary obstruction (RBO), time to RBO (TRBO), technical and clinical success, and adverse events. Results: A total of 73 patients were enrolled in this study. The non-obstruction rate at 6 months was 61%. The median OS and TRBO were 233 and 216 days, respectively. The technical and clinical success rates were 100% and 97%, respectively. Furthermore, the rate of occurrence of RBO and adverse events was 49% and 21%, respectively. The length of bile duct stenosis (<2.2 cm) was the only significant risk factor for stent migration. Conclusions: The non-obstruction rate of a novel fully covered SEMS for MDBO is comparable to that reported earlier but shorter than expected. Short bile duct stenosis is a significant risk factor for stent migration.

Metabolome analysis for pancreatic cancer risk in nested case-control study: Japan Public Health Center-based prospective Study.

Discovery of a high-risk group for pancreatic cancer is important for prevention of pancreatic cancer. The present study was conducted as a nested case-control study including 170 pancreatic cancer cases and 340 matched controls of our population-based cohort study involving 30 239 subjects who answered a baseline questionnaire and supplied blood samples. Twelve targeted metabolites were quantitatively analyzed by gas chromatography/tandem mass spectrometry. Odds ratios (OR) and their corresponding 95% confidence intervals (CI) were calculated using conditional logistic regression models. Statistically significant P-value was defined as P < .05. Increasing 1,5-anhydro-d-glucitol (1,5-AG) levels were associated with a decreasing trend in pancreatic cancer risk (OR of quartile 4 [Q4], 0.50; 95% CI, 0.27-0.93; P = .02). Increasing methionine levels were also associated with an increasing trend of pancreatic cancer risk (OR of Q4, 1.79; 95% CI, 0.94-3.40: P = .03). Additional adjustment for potential confounders attenuated the observed associations of 1,5-AG and methionine (P for trend = .06 and .07, respectively). Comparing subjects diagnosed in the first 0-6 years, higher levels of 1,5-AG, asparagine, tyrosine and uric acid showed a decreasing trend for pancreatic cancer risk (P for trend = .04, .04, .04 and .02, respectively), even after adjustment for potential confounders. We found that the 12 target metabolites were not associated with pancreatic cancer risk. However, metabolic changes in the subjects diagnosed in the first 0-6 years showed a similar tendency to our previous reports. These results might suggest that these metabolites are useful for early detection but not for prediction of pancreatic cancer.

Pancreatic inflammation and atrophy are not associated with pancreatic cancer concomitant with intraductal papillary mucinous neoplasm.

BACKGROUND: Inflammation-induced carcinogenesis in pancreatic ductal adenocarcinoma (PDAC) has been reported; however, its involvement in PDAC with intraductal papillary mucinous neoplasm (IPMN) remains unclear. We herein investigated the relationship between pancreatic atrophy and inflammation and the incidence of PDAC concomitant with IPMN. METHODS: This study included 178 consecutive patients who underwent surgical resection for PDAC with IPMN (N = 21) and IPMN (N = 157) between April 2001 and October 2016. A multivariable logistic regression analysis was conducted to assess the relationship between pancreatic inflammation and atrophy and the incidence of PDAC concomitant with IPMN, with adjustments for clinical characteristics and imaging features. Pathological pancreatic inflammation and atrophy were evaluated in resected specimens. RESULTS: High degrees of pancreatic inflammation and atrophy were not associated with the incidence of PDAC with IPMN (multivariable odds ratio [OR] = 0.5, 95% confidence interval [CI] = 0.07 to 3.33, P = .52, adjusted by clinical characteristics, OR = 0.9, 95% CI = 0.10 to 5.86, P = .91, adjusted by imaging studies; OR = 0.2, 95% CI = 0.009 to 1.31, P = .10, adjusted by clinical characteristics, OR = 0.2, 95% CI = 0.01 to 1.43, P = .12, adjusted by imaging studies, respectively). CONCLUSIONS: Pancreatic inflammation and atrophy were not associated with pancreatic cancer concomitant with IPMN.

Identification of highly sensitive biomarkers that can aid the early detection of pancreatic cancer using GC/MS/MS-based targeted metabolomics.

BACKGROUND: To improve prognosis of pancreatic cancer (PC) patients, the discovery of more reliable biomarkers for the early detection is desired. METHODS: Blood samples were collected by 2 independent groups. The 1st set was included 55 early PC and 58 healthy volunteers (HV), and the 2nd set was included 16 PC and 16HV. The 16 targeted metabolites were quantitatively analyzed by gas chromatography/tandem mass spectrometry together with their corresponding stable isotopes. In the 1st set, the levels of these metabolites were evaluated, and diagnostic models were constructed via multivariate logistic regression analysis, leading to validation using the 2nd set. RESULTS: In the 1st set, model X consisting of 4 candidates based on our previous report possessed higher sensitivity (74.1%) than carbohydrate antigen 19-9 (CA19-9). Model Y, consisting of 2 metabolites newly selected from 16 metabolites via stepwise method possessed higher sensitivity (70.4%) than CA19-9. Furthermore, combining model Y with CA19-9 increased its sensitivity (90.7%) and specificity (89.5%). In the 2nd set, combining model Y with CA19-9 displayed high sensitivity (81.3%) and specificity (93.8%). In particular, it displayed very high sensitivity (100%) for resectable PC. CONCLUSIONS: Quantitative analysis confirmed that metabolomics-based diagnostic methods are useful for detecting PC early.

Smoking Status and the Incidence of Pancreatic Cancer Concomitant With Intraductal Papillary Mucinous Neoplasm.

OBJECTIVES: The effect of smoking status on the incidence of pancreatic ductal adenocarcinoma (PDAC) concomitant with intraductal papillary mucinous neoplasm (IPMN) has not been clarified. This study investigated the association of smoking status with PDAC concomitant with IPMN. METHODS: The subjects were 124 consecutive patients undergoing resection of IPMNs (intraductal papillary mucinous adenoma (IPMA): N = 77, invasive IPMN: N = 31, and PDAC with IPMN: N = 16) between April 2008 and October 2015. The associations between smoking status (never/former/current smoker) or cumulative pack-years (0-19/20-39/≥40) and the incidence of PDAC concomitant with IPMN or invasive IPMN were evaluated. RESULTS: Current smoking, not former smoking, was associated with the incidence of PDAC concomitant with IPMN (PDAC with IPMN vs IPMN alone; P = 0.004, PDAC with IPMN vs IPMA; P = 0.004, PDAC with IPMN vs invasive IPMN; P = 0.04, respectively), but not that of invasive IPMN (invasive IPMN vs IPMA; P = 0.85). Cumulative pack-years were higher in patients who had PDAC concomitant with IPMN than in patients with invasive IPMN (P = 0.04). Cumulative pack-years were not associated with smoking status (current vs former). CONCLUSIONS: Current smoking, not former smoking, was associated with the incidence of PDAC concomitant with IPMN. Cessation of smoking may be recommended for patients with IPMN.

Association between serum SPan-1 and lymph node metastasis in invasive intraductal papillary mucinous neoplasm of the pancreas.

BACKGROUND AND AIM: Lymph node metastasis predicts poorer prognoses in patients with invasive intraductal papillary mucinous neoplasms of the pancreas (IPMNs). Factors associated with lymph node metastasis of invasive IPMN remain unclear. Therefore, this study aimed to define factors associated with lymph node metastasis of invasive IPMN. METHODS: Between June 2000 to August 2015, 156 consecutive patients with IPMN underwent surgical resection at Kobe University Hospital, and were enrolled in this study. The relationship between lymph node metastasis and clinical characteristics, including imaging studies and serum tumor markers, was evaluated. A multivariate logistic regression analysis was performed to assess the relationship between serum tumor markers and the presence of lymph node metastasis of IPMN, adjusted for clinical characteristics. RESULTS: Lymph node metastasis was observed in 7.7% (12/156) of IPMNs via a pathological examination. The multivariate logistic regression analysis revealed that serum SPan-1 was associated with the presence of lymph node metastasis of IPMN (odds ratio [OR] = 7.32; 95% confidence interval [CI] = 1.10 to 56.0; P = 0.04). In addition, survival was poorer among serum SPan-1-positive patients than SPan-1 negative patients (Log-rank test; P = 0.0002). Lymph node enlargement was detected preoperatively on computed tomography scans in only 16.7% (2/12) of cases that were positive for lymph node metastasis. CONCLUSIONS: Elevated serum SPan-1 was associated with lymph node metastasis in this cohort of patients who underwent resection for invasive IPMN.

Pancreatic cancer screening using a multiplatform human serum metabolomics system.

AIM: To examine a novel screening method for pancreatic cancer involving gas chromatography/mass spectrometry and liquid chromatography/mass spectrometry-based metabolomics analysis. MATERIALS & METHODS: Sera from pancreatic cancer patients (n = 59) and healthy volunteers (n = 59) were allocated to the training set or validation set. Serum metabolome analysis was carried out using our multiplatform metabolomics system. A diagnostic model was constructed using a two-phase screening method that was newly advocated. RESULTS: When the training set was used, the constructed diagnostic model exhibited high sensitivity (100%) and specificity (80%) for pancreatic cancer. When the validation set was used, the model displayed high sensitivity (84.1%) and specificity (84.1%). CONCLUSION: We successfully developed a diagnostic model for pancreatic cancer using a multiplatform serum metabolomics system.