Cocatalyst activity mapping for photocatalytic materials revealed by the pattern-illumination time-resolved phase microscopy.

Photocatalytic water-splitting represents a promising avenue for clean hydrogen production, necessitating an in-depth understanding of the photocatalytic reaction mechanism. The majority of the photocatalytic materials need cocatalysts to enhance the photo-oxidation or reduction reactions. However, the working mechanism, such as collecting charge carriers or reducing the reaction barrier, is not clear because they disperse inhomogeneously on a surface, and it is difficult to follow the local charge carrier behavior. This study employs the pattern-illumination time-resolved phase microscopy (PI-PM) method to unravel the spatial charge carrier behavior in photocatalytic systems, utilizing time-resolved microscopic image (refractive index change) sequences and their clustering analyses. This approach is robust for studying the change in local charge carrier behavior. We studied two major cocatalyst effects on photocatalysts: TiO2 with/without Pt and hematite with/without CoPi. The PI-PM method, supported by charge type clustering and the effects of scavengers, allowed for the analysis of local activity influenced by cocatalysts. This approach revealed that the introduction of cocatalysts alters the local distribution of charge carrier behavior and significantly impacts their decay rates. In TiO2 systems, the presence of Pt cocatalysts led to a local electron site on the micron scale, extending the lifetime to a few tens of microseconds from a few microseconds. Similarly, in hematite films with CoPi, we observed a notable accumulation of holes at cocatalyst sites, emphasizing the role of cocatalysts in enhancing photocatalytic efficiency. The study's findings highlight the complexity of charge carrier dynamics in photocatalytic processes and the significant influence of cocatalysts.

Brain Metastasis Mimicking Glioma on Imaging Appearance During Tyrosine Kinase Inhibitor Administration: A Case Series and Literature Review.

OBJECTIVE: Preoperative imaging diagnosis is critical to planning treatment strategies; however, it is occasionally challenging and sometimes misleading. The effects of molecularly targeted therapies on imaging appearances remain uncharted. We investigated the imaging characteristics of brain metastasis during tyrosine kinase inhibitor (TKI) administration. METHODS: We analyzed the 12 cases of brain metastasis from lung cancer in our institute, including a case of a 49-year-old woman under gefitinib. Additionally, we reviewed the cases of brain metastasis from lung cancer with gefitinib treatment in the literature. RESULTS: A woman during five-year gefitinib treatment for postoperative recurrence of lung adenocarcinoma was found to have a cerebellar tumoral lesion incidentally on magnetic resonance imaging (MRI). This lesion did not harbor any peritumoral edema, along with appearing hypometabolic on fluorodeoxyglucose (FDG) positron emission tomography (PET). This appearance was inconsistent with a typical metastatic appearance, and high-grade glioma was instead highly suspected, leading to a decision to proceed to gross total tumor resection. The pathological diagnosis, however, was brain metastasis from lung cancer. The other 11 cases without TKI treatment showed peritumoral edema on MRI and higher accumulation of FDG on PET. The two cases of brain metastasis with gefitinib in the literature showed no peritumoral edema on MRI. CONCLUSION: TKIs like gefitinib can affect tumor biology, leading to a loss of typical imaging findings such as peritumoral brain edema and hyper-metabolism. As preoperative imaging diagnosis guides us in surgical planning, including biopsy or resection, ongoing treatment information should be fully integrated into imaging interpretation.

Colon-cancer liver metastasis is effectively targeted by recombinant methioninase (rMETase) in an orthotopic mouse model.

BACKGROUND: Colorectal cancer liver metastasis (CCLM) is the most frequent cause of death of colorectal cancer. Development of novel new effective therapy is needed for CCLM patients to improve outcome. The aim of the present study was to investigate the efficacy of recombinant methioninase (rMETase) on a CCLM orthotopic mouse model of liver metastasis established using the human colon cancer cell line HT29 expressing red fluorescent protein (RFP). MATERIALS AND METHODS: Orthotopic CCLM nude mouse models were randomized into two groups: control group (n = 6, PBS 200 µl, i.p., daily); rMETase group (n = 6, 100 units/200 µl, i.p., daily). Tumor volume was measured on day 0 and day 15. Body weight was measured twice a week. All mice were sacrificed on day 15. RESULTS: rMETase significantly inhibited the increase of the liver metastasis as determined by RFP fluorescence area and intensity (p = 0.016 and 0.015, respectively). There was no significant difference of body weight between either group on any day. CONCLUSIONS: The present study suggests that rMETase has future potential therapy for CCLM in the clinic.

Synergy of oral recombinant methioninase (rMETase) and 5-fluorouracil on poorly differentiated gastric cancer.

Gastric cancer is highly malignant and recalcitrant to first line chemotherapies that include 5-fluorouracil (5-FU). Cancer cells are addicted to methionine for their proliferation and survival. Methionine addiction of cancer is known as the Hoffman effect. Methionine restriction with recombinant methioninase (rMETase) has been shown to selectively starve cancer cells and has shown synergy with cytotoxic chemotherapy including 5-FU. The present study aimed to investigate the efficacy of rMETase alone and the combination with 5-FU on poorly differentiated human gastric cancer cell lines (MKN45, NUGC3, and NUGC4) in vitro and vivo. rMETase suppressed the tumor growth of 3 kinds of poorly differentiated gastric cancer cells in vitro. The fluorescence ubiquitination-based cell cycle indicator (FUCCI) demonstrated cancer cells treated with rMETase were selectively trapped in the S/G2 phase of the cell cycle. In the present study, subcutaneous MKN45 gastric cancer models were randomized into four groups when the tumor volume reached 100 mm3: G1: untreated control; G2: 5-FU (i.p., 50 mg/kg, weekly, three weeks); G3: oral-rMETase (o-rMETase) (p.o., 100 units/body, daily, three weeks); G4: 5-FU with o-rMETase (5-FU; i.p., 50 mg/kg, weekly, three weeks o-rMETase; p.o., 100 units/body, daily, three weeks). All mice were sacrificed on day 22. Body weight and estimated tumor volume were measured twice a week. 5-FU and o-rMETase suppressed tumor growth as monotherapies on day 18 (p = 0.044 and p = 0.044). However, 5-FU combined with o-rMETase was significantly superior to each monotherapy (p < 0.001 and p < 0.001, respectively) and induced extensive necrosis compared to other groups. The combination of 5-FU and o-rMETase shows promise for transformative therapy for poorly differentiated gastric cancer in the clinic.

Expression of Corticotropin-Releasing Hormone and Its Receptors May Be Associated With Survival Rate in Pancreatic Cancer.

Background and Aims: Corticotropin-releasing hormone (CRH) is a major regulator of the stress response to internal and external factors. CRH and its receptors (CRHR1 and CRHR2) are expressed in the central nervous system and some cancer cells, suggesting the importance of CRH signaling in pancreatic cancers. However, the clinicopathological significance of CRH remains unknown because the immunolocalization of CRH, CRHR1, and CRHR2 has not been examined in pancreatic carcinoma tissues. We clarified the correlation of the expression of CRH and its receptors with overall survival in pancreatic cancer. Methods: This study evaluated 96 patients with pancreatic cancer who underwent microscopic complete resection (R0) but not neoadjuvant chemotherapy from 1988 to 2007 at Tohoku University Hospital, Japan. CRH, CRHR1, and CRHR2 immunoreactivity were detected in the pancreatic carcinoma cells. Overall survival curves were generated according to the Kaplan-Meier method. Results: CRHR1 immunoreactivity was significantly associated with an increased risk of poorer prognosis in all patients (P = .038) and the adjuvant therapy group (P = .022). Overall survival was worse in the CRHR1-positive group than in the CRHR1-negative group among the 62 patients treated with gemcitabine hydrochloride (P = .046) and the 22 patients treated with other drugs (P = .047). CRHR1 expression was correlated with survival in univariate analysis but not in multivariate analysis. Conclusion: This study is the first to immunolocalize CRH, CRHR1, and CRHR2 in pancreatic carcinoma tissues and to examine the biological prognosis. This study revealed that survival in patients with pancreatic cancer was significantly associated with expression of CRHR1 by assessing biological progression according to CRH and the expression of its receptors. However, CRHR1 expression was correlated with survival in univariate analysis but not in multivariate analysis.

High Incidence of Lymph-node Metastasis in a Pancreatic-cancer Patient-derived Orthotopic Xenograft (PDOX) NOG-Mouse Model.

BACKGROUND/AIM: Our laboratory pioneered the patient-derived orthotopic xenograft (PDOX) model. An important goal of PDOX-model development is facile visualization of metastasis in live mice. In the present report we evaluated tumor growth and metastasis in pancreatic cancer PDOX NOG [Non-obese diabetes (NOD)/Scid/IL2Rγnull]-and nude-mouse models using red fluorescent protein (RFP)-expressing tumor stroma to visualize the primary tumor and metastasis. MATERIALS AND METHODS: A patient-derived pancreatic cancer was initially implanted in transgenic RFP-expressing nude mice. Then, tumor fragments, which acquired RFP expressing stroma while growing in RFP-expressing nude mice were orthotopically implanted in nude and NOG mice. The primary pancreatic tumor and metastasis were observed 8 weeks after implantation. RESULTS: Lymph-node metastases expressing red fluorescence were detected only in NOG mice. Significantly faster growth of primary pancreatic tumors and a higher incidence of lymph-node metastasis occurred in NOG mice compared to nude mice. CONCLUSION: RFP-expressing tumor stroma, which traffics together with cancer cells to lymph nodes, is useful to observe tumor behavior, such as lymph-node metastasis in a PDOX NOG-mouse model which can be used for evaluation of novel anti-metastatic agents, as well as personalized therapy to identify effective drugs.

What is the impact of zinc deficiency for pancreatectomies in patients with pancreatic ductal adenocarcinoma?

BACKGROUND: and purpose: Zinc is an essential element for human health and plays an important role in metabolic, immunological and other biological processes. The present study was conducted to investigate the association between zinc deficiency (ZD) and the perioperative clinical course in patients with pancreatic ductal adenocarcinoma (PDAC). METHODS: Of 216 patients with PDAC who underwent elective pancreatectomy between 2013 and 2017 at our institution, 206 patients with sufficient clinical data were retrospectively reviewed. The perioperative variables were compared and the risk factors associated with infectious complications were identified. RESULTS: ZD was preoperatively present in 36 (17.5%) of 206 patients with PDAC. In the patients of the ZD group, a higher proportion of males, higher preoperative modified Glasgow prognostic scores, a higher neutrophil-to-lymphocyte ratio, and a higher occurrence of postoperative infectious complications after pancreatectomy were observed, compared to the non-ZD group. By a univariate analysis, three risk factors were significantly associated with infectious complications after pancreatectomy: ZD (vs non-ZD: p = 0.002), serum albumin <3.5 g/dl (vs ≥ 3.5 g/dl: p = 0.005), and the procedure of pancreaticoduodenectomy (vs others: p = 0.013). By multivariate logistic regression analysis, the occurrence of infectious complications was significantly associated with ZD (OR 3.430, 95%CI 1.570 to 7.490, p = 0.002) and the procedure of pancreaticoduodenectomy (OR 2.030, 95%CI 1.090 to 3.770, p = 0.025). CONCLUSIONS: The current study newly demonstrated that ZD could serve as a preoperative predictor of infectious complications after pancreatectomies in the patients with PDAC.

Impact of Tumor-Derived DNA Testing in Peritoneal Lavage of Pancreatic Cancer Patients with and Without Occult Intra-Abdominal Metastases.

BACKGROUND: The fractional abundance of tumor-derived DNA in body fluids depends on the metastatic sites and the degree of expansion. We aimed to assess the clinical significance of tumor-derived DNA testing in the peritoneal lavage of patients with pancreatic cancer. METHODS: The prevalence and abundance of tumor-derived DNA was assessed in 204 subjects with ascites by peritoneal lavage (AS) and the evaluable paired plasma (PL) from 149 pancreatic cancer patients undergoing abdominal exploration. Genetic profiles were evaluated by next-generation sequencing, and prognostic impact was assessed using Cox proportional hazard models. RESULTS: Of 204 subjects, AS samples from patients with peritoneal dissemination (PER+) and positive cytology (CY+) showed significantly higher prevalence and abundance of tumor-derived DNA than those with negative counterparts. Tumor-derived DNA prevalence and abundance in AS were more likely to be higher than in paired PL in a subgroup of patients with PER+ and CY+, respectively. Next-generation sequencing revealed concordant or discrepant mutational patterns between the AS and PL samples. Multivariate analysis showed that both tumor-derived DNA in AS (hazard ratio [HR] 3.940, p = 0.009) and PL (HR 2.936, p = 0.026) were independently associated with poor survival in treatment-naïve patients. In patients who underwent resection, tumor-derived DNA positivity in the AS was more predictive of early recurrence than in PL. CONCLUSIONS: Tumor-derived DNA in AS can serve as characterizing the genetic profiles of tumor cells attributable to the development of PER+ and predicting the minimal residual disease and early recurrence in patients with pancreatic cancer.

Probiotic-related bacteremia after major hepatectomy for biliary cancer: a report of two cases.

BACKGROUND: Probiotics have been reported to be beneficial for the prevention of postoperative complications and are often used during the perioperative period. Among the probiotic-related adverse events, bacteremia is rare. Here, we report two cases of probiotic-related bacteremia after major hepatectomy for biliary cancer. CASE PRESENTATION 1: A 74-year-old man was referred to our hospital to be treated for gallbladder cancer. Neoadjuvant chemotherapy, two courses of gemcitabine plus S-1 combination therapy, was administered. Extended right hepatectomy with caudate lobectomy, extrahepatic bile duct resection and biliary reconstruction were performed 3 weeks after chemotherapy. Probiotics, Clostridium butyricum (C. butyricum) MIYAIRI 588, were administered 6 days before surgery and continued after surgery. Sepsis of unknown origin occurred 17 days after surgery and developed into septic shock. C. butyricum was detected in blood cultures at postoperative day 26 and 45. After stopping the probiotic agent, C. butyricum was undetectable in the blood cultures. The patient died due to an uncontrollable sepsis 66 days after surgery. CASE PRESENTATION 2: A 63-year-old man with diabetes mellitus whose past history included total colectomy, papillectomy, and Frey's operation at the age of 19, 34 and 48, respectively, was referred to our hospital to be treated for perihilar cholangiocarcinoma. Extended left hepatectomy with caudate lobectomy, extrahepatic bile duct resection and reconstruction of bile duct were performed. Probiotics were administered during the perioperative period. Combined probiotics that included lactomin, amylolytic bacillus and C. butyricum, were given before surgery. C. butyricum MIYAIRI 588 was given after surgery. Sepsis occurred 16 days after surgery and developed to respiratory failure 8 days later. Blood culture at postoperative day 25 revealed Enterococcus faecalis and C. butyricum. After the probiotics were stopped at postoperative day 27, C. butyricum was not detected in the blood culture. The general condition improved with intensive care. The patient was transferred to another hospital for rehabilitation at postoperative day 156. CONCLUSION: It should be noted that the administration of probiotics in severe postoperative complications can lead to probiotic-related bacteremia.

Utility of monitoring the serum levetiracetam concentration for intraoperative seizure control during awake craniotomy.

Awake craniotomy is an established procedure for resecting brain tumors in eloquent lesions, and intraoperative seizure is one of the most important complications. Phenytoin is normally used to control intraoperative seizures. Recently, phenytoin was replaced with levetiracetam at our institution because the latter has fewer side effects. While the phenytoin dose is calibrated in accordance with the serum concentration, there is currently no consensus on a method of monitoring the serum concentration of levetiracetam or the effective concentration range needed to control intraoperative seizures during awake craniotomy. The present study therefore aimed to determine whether monitoring the serum levetiracetam concentration is useful for controlling intraoperative seizures during awake craniotomy. The intraoperative serum concentration of levetiracetam during awake craniotomy was measured in 34 patients and compared with that of phenytoin in 33 patients undergoing the same procedure. The levetiracetam concentration inversely correlated with body surface area (BSA) and estimated glomerular filtration rate (eGFR). Levetiracetam was superior to phenytoin in terms of the correlation between the serum concentration and the dose adjusted for BSA and eGFR (correlation coefficient, 0.49 vs 0.21). Furthermore, the serum levetiracetam concentration in patients with intraoperative seizures was below the 95% confidence interval (CI) of the regression line whereas the serum phenytoin concentration of two patients with seizures was within the 95% CI, indicating that evaluating the serum levetiracetam concentration against the BSA and eGFR-adjusted dosage may be useful in preventing intraoperative seizures during awake craniotomy by allowing prediction of the seizure risk and enabling more accurate dosage calibration.

Increased neutrophil-lymphocyte ratio predicts recurrence in patients with well-differentiated pancreatic neuroendocrine neoplasm based on the 2017 World Health Organization classification.

BACKGROUND: The prognostic values of inflammation-based markers in well-differentiated pancreatic neuroendocrine neoplasms, diagnosed according to the new 2017 World Health Organization classification, have remained unclear. Therefore, we assessed the ability to predict the recurrence of such markers after curative resection in patients with these neoplasms. METHODS: Circulating/systemic neutrophil-lymphocyte, monocyte-lymphocyte, platelet-lymphocyte, and platelet-white cell ratios were evaluated in 120 patients who underwent curative resection for well-differentiated pancreatic neuroendocrine neoplasms without synchronous distant metastasis between 2001 and 2018. Recurrence-free-survival and overall survival were compared using Kaplan-Meier analysis and log-rank tests. Univariate or multivariate analyses, using a Cox proportional hazards model, were used to calculate hazard ratios with 95% confidence intervals. RESULTS: Univariate analysis demonstrated that preoperative neutrophil-lymphocyte ratio, tumor size, European Neuroendocrine Tumor Society TMN classification, 2017 World Health Organization classification, and venous invasion were associated with recurrence. The optimal preoperative neutrophil-lymphocyte ratio cut-off value was 2.62, based on receiver operating characteristic curve analysis. In multivariate analysis, a higher preoperative neutrophil-lymphocyte ratio (HR = 3.49 95% CI 1.05-11.7; P = 0.042) and 2017 World Health Organization classification (HR = 8.81, 95% CI 1.46-168.2; P = 0.015) were independent recurrence predictors. CONCLUSIONS: The circulating/systemic neutrophil-lymphocyte ratio is a useful and convenient preoperative prognostic marker of recurrence in patients with well-differentiated pancreatic neuroendocrine neoplasm based on the 2017 World Health Organization classification.

Oral recombinant methioninase combined with paclitaxel arrests recalcitrant ovarian clear cell carcinoma growth in a patient-derived orthotopic xenograft (PDOX) nude-mouse model.

PURPOSE: Advanced ovarian clear cell carcinoma (OCCC) is a recalcitrant disease, often resistant to the first-line platinum-based therapy. Using a novel patient-derived orthotopic xenograft (PDOX) nude-mouse model of OCCC, we tested whether oral-recombinant methioninase (o-rMETase) could enhance the efficacy of paclitaxel (PTX). METHODS: The OCCC PDOX model was established and passaged in nude mice. The OCCC PDOX models were randomized into 5 groups. G1: untreated control; G2: paclitaxel (PTX) (20 mg/kg, intraperitoneal (i.p.) injection, weekly); G3: o-rMETase (100 units, oral, daily); G4: PTX (20 mg/kg, i.p. injection, weekly) + carboplatinum (CBDCA) (40 mg/kg, i.p. injection weekly); G5: PTX (20 mg/kg, i.p. injection, weekly) + o-rMETase (100 units, oral, daily). The treatment period was 2 weeks. RESULTS: The combination of PTX and o-rMETase arrested OCCC tumor growth (relative tumor volume: 1.09 ± 0.63 (mean ± SD)) compared with the untreated control (relative tumor volume: 3.92 ± 1.04 (mean ± SD)) (p < 0.0001). There was no significant difference in relative tumor volume between PTX plus o-rMETase and PTX plus CBDCA (relative tumor volume: 1.39 ± 0.37 (mean ± SD)) (p = 0.93). CONCLUSION: PTX plus o-rMETase arrested the OCCC tumor growth. o-rMETase is readily administered and can greatly enhance first-line therapy of a recalcitrant cancer. The novel and effective treatment strategy in the present report has future clinical potential for patients with OCCC, especially for patients who cannot well tolerate platinum-based therapy.

Intracholecystic papillary neoplasm arising in the cystic duct and extending into common bile duct: a case report.

An 83-year-old man without specific symptoms was referred to our hospital for further evaluation and treatment of apparent double primary tumors of the cystic duct and common bile duct. Computed tomography showed contrast-enhanced solid tumors in the cystic duct and common bile duct. Magnetic resonance imaging showed that the bile duct tumor was isointense on T1-weighted images and had low intensity on T2-weighted images. In addition, the bile duct tumor showed high intensity on diffusion-weighted images. Endoscopic ultrasonography revealed the tumor of the common bile duct and endoscopic retrograde cholangiopancreatography demonstrated a filling defect in the bile duct. The cystic duct was not identified on endoscopic ultrasonography or endoscopic retrograde cholangiopancreatography. Transpapillary biopsy of the bile duct tumor showed adenocarcinoma. The patient was diagnosed with double primary tumors of the cystic duct and the common bile duct and underwent subtotal stomach-preserving pancreaticoduodenectomy. Microscopic examination with molecular profiling of the tumors revealed a high-grade noninvasive intracholecystic papillary neoplasm of the cystic duct extending into the common bile duct and forming a tubulopapillary neoplasm with invasion of the common bile duct.

[A Successful Case of Pancreaticoduodenectomy after Neoadjuvant Therapy for Pancreatic Head Cancer with Acute Pancreatitis Due to Iatrogenic Injury of the Pancreatic Duct].

A 64-year-old woman was referred to our hospital for treatment of pancreatic head cancer with acute pancreatitis due to iatrogenic injury of the pancreatic duct during endoscopic retrograde cholangiopancreatography. In addition to a 28 mm pancreatic head tumor, soft tissue shadow and fluid collection surrounding the superior mesenteric artery(SMA)due to pancreatitis were observed in the abdominal CT scan. The tumor was histologically diagnosed as adenocarcinoma by endoscopic ultrasound-guided fine needle aspiration. Neoadjuvant chemotherapy with gemcitabine and S-1 was performed to control the progression of the pancreatic cancer and improve the inflammatory changes for reduction of the operative risk. After 2 courses of neoadjuvant chemotherapy, abdominal CT scan revealed stable disease according to the Response Evaluation Criteria in Solid Tumors and attenuation of the inflammatory changes surrounding the SMA. Then, subtotal stomach- preserving pancreaticoduodenectomy was performed without the difficulty of peeling around the SMA in spite of the old inflammatory changes. Histological examination of the resected specimen showed R0 resection. The patient was discharged 18 days after surgery without any complications and is surviving 9 months postoperatively without any recurrence. Neoadjuvant chemotherapy was helpful for disease control and improvement of the inflammatory changes.

[Reconstruction of Portal Vein and Superior Mesenteric Vein Using Superficial Femoral Vein Graft in Surgical Resection of Pancreatic Head Cancer-A Case Report].

We report a case of reconstruction of the portal vein(PV)and superior mesenteric vein(SMV)using a superficial femoral vein graft in total pancreatectomy for pancreatic cancer. A 62-year-old man visited a previous hospital due to epigastric pain and bilirubinuria and was diagnosed with pancreatic cancer. The patient was referred to our hospital for further examination and treatment. Abdominal CT scan revealed a 30 mm pancreatic head tumor with an abutment of almost 360 degrees around the superior mesenteric artery(SMA)and extensive involvement from the PV to branches of the SMV, radiologically classified as locally advanced unresectable pancreatic cancer. Although gemcitabine plus nab-paclitaxel combination therapy(GnP)was performed, the patient developed drug-induced lung injury after 3 courses. GnP was stopped, and chemoradiation therapy with S-1 was performed. After chemoradiation therapy, the tumor shrank to 14 mm, while no change of the abutment around SMA was observed. After 8 months from the initial diagnosis, total pancreatectomy and resection of the PV/SMV were performed. Approximately 70 mm of the PV/SMV was surgically removed and was reconstructed using a graft from the left superficial femoral vein in consideration of the length and diameter. Although delayed gastric emptying was postoperatively observed, the patient was discharged 39 days after operation, then received adjuvant therapy with S-1. The patient is alive without recurrence and the patency of PV/SMV was well maintained.

Staging laparoscopy is mandatory for the treatment of pancreatic cancer to avoid missing radiologically negative metastases.

PURPOSE: Staging laparoscopy is considered useful for determining treatment plans for advanced pancreatic cancer. However, the indications for staging laparoscopy are not clear. This study aimed to evaluate the safety of staging laparoscopy and its usefulness for detecting distant metastases in patients with pancreatic cancer. METHODS: A total of 146 patients with pancreatic cancer who underwent staging laparoscopy between 2013 and 2019 were analyzed. Staging laparoscopy was performed in all pancreatic cancer patients in whom surgery was considered possible. RESULTS: In this cohort, 42 patients (29%) were diagnosed with malignant cells on peritoneal lavage cytology, 9 (6%) had peritoneal dissemination, and 11 (8%) had liver metastases. A total of 48 (33%) had radiologically negative metastases. On a multivariate analysis, body and tail cancer [odds ratio (OR) 5.00, 95% confidence interval (CI) 2.15-11.6, p < 0.001], high CA19-9 level [OR 4.04, 95% CI 1.74-9.38, p = 0.001], and a resectability status of unresectable (OR 2.31, 95% CI 1.03-5.20, p = 0.04) were independent risk factors for radiologically negative metastases. CONCLUSIONS: Staging laparoscopy can be safely performed and is useful for the diagnosis of radiologically negative metastases. Staging laparoscopy should be routinely performed for the accurate diagnosis of pancreatic cancer patients before pancreatectomy and/or local treatment, such as radiotherapy.

Liver resections in patients with prior bilioenteric anastomosis are predisposed to develop organ/space surgical site infections and biliary leakage: results from a propensity score matching analysis.

PURPOSE: The aims of this study were to compare the perioperative outcomes after hepatectomy with prior bilioenteric anastomosis to those without prior anastomosis, and to elucidate the mechanisms and preventative measures of its characteristic complications. METHODS: The demographic data and perioperative outcomes of 525 hepatectomies performed between January 2007 and December 2018, including 40 hepatectomies with prior bilioenteric anastomosis, were retrospectively analyzed. RESULTS: A propensity score matching analysis demonstrated that hepatectomies with prior bilioenteric anastomosis were associated with a higher frequency of major complications (p = 0.015), surgical site infection (p = 0.005), organ/space surgical site infection (p = 0.003), and bile leakage (p = 0.007) compared to those without. A multivariate analysis also elucidated that prior bilioenteric anastomosis was one of the independent risk factors of organ/space surgical site infection. In the patients with prior bilioenteric anastomosis, bile leakage was associated with organ/space surgical site infection at a significantly higher rate than those without prior bilioenteric anastomosis (p < 0.001). CONCLUSIONS: Prior bilioenteric anastomosis is a strong risk factor for organ/space surgical site infections, which might be induced by bile leakage. To prevent infectious complications after hepatectomy with prior bilioenteric anastomosis, meticulous liver transection to reduce bile leakage rate is thus considered to be mandatory.

Genetic Characteristics of Mismatch Repair-deficient Glioblastoma.

Mismatch repair (MMR) gene deficiency is rarely observed in gliomas, a constitutional defect is associated with tumorigenesis in Lynch syndrome, and an acquired defect is associated with hypermutation after temozolomide treatment. However, the meaning of MMR gene deficiency in gliomas is unclear. Two cases of MMR-deficient glioblastomas are reported, and mutational status of oncogenes was compared between primary and recurrent tumor samples in a glioblastoma patient with Lynch syndrome. Additionally, the characteristics of MMR-deficient glioblastomas were analyzed using public glioma datasets to determine the meaning of MMR deficiency in gliomas. Case 1 was a glioblastoma patient with Lynch syndrome, and treatment with pembrolizumab for the recurrent tumor was temporarily effective for a short period. Comparison of mutational changes between primary and recurrent tumor samples showed many additional mutated genes associated with multiple signaling pathways in the recurrent tumor. Tumor recurrence and chemoresistance could be associated with intratumoral heterogeneity and accelerated tumor progression due to defects of multiple signaling pathways. Case 2 was a glioblastoma patient with acquired MMR gene deficiency, and she died of rapid progression of bone marrow metastases. This rare clinical course was considered to be associated with gene expression changes and heterogeneity that resulted from MMR gene deficiency. Two cases of MMR gene-deficient glioblastomas were presented, and their genetic characteristics suggested that their clinical courses could be associated with MMR gene deficiency.

Triple-Methyl Blockade With Recombinant Methioninase, Cycloleucine, and Azacitidine Arrests a Pancreatic Cancer Patient-Derived Orthotopic Xenograft Model.

OBJECTIVES: Methionine addiction is a fundamental and general hallmark of cancer caused by enhanced methyl flux. In the present study, we effected a novel methionine-methylation blockade to target a patient-derived orthotopic xenograft model of pancreatic cancer. METHODS: The pancreatic cancer patient-derived orthotopic xenograft mouse models were randomized into 6 groups of 8 mice each and treated for 2 weeks: untreated control; azacitidine; oral recombinant methioninase (o-rMETase); o-rMETase plus cycloleucine; o-rMETase plus cycloleucine plus azacitidine (triple-methyl blockade therapy); and gemcitabine (positive control). RESULTS: Triple-methyl blockade therapy arrested tumor growth (mean relative tumor volume, 1.03 [standard deviation, 0.36]) and was significantly more effective compared with azacitidine (P = 0.0001); o-rMETase (P = 0.007); or o-rMETase plus cycloleucine (P = 0.04). Gemcitabine alone also inhibited but did not arrest tumor growth (mean relative tumor volume, 1.50 [standard deviation, 0.30]). The percentage of cancer cells that were negative for 5-methylcytosine staining in immunohistochemistry, indicating reduction of DNA methylation, increased with triple-methyl blockade therapy (37.5%), compared with gemcitabine (1.8%); o-rMETase (2.8%); azacitidine (9.0%); or o-rMETase plus cycloleucine (10.6%). CONCLUSIONS: This new concept of triple-methyl blockade therapy has clinical potential for pancreatic cancer, which is currently a recalcitrant disease.

A novel patient-derived orthotopic xenograft (PDOX) mouse model of highly-aggressive liver metastasis for identification of candidate effective drug-combinations.

Liver metastasis is a recalcitrant disease that usually leads to death of the patient. The present study established a unique patient-derived orthotopic xenograft (PDOX) nude mouse model of a highly aggressive liver metastasis of colon cancer. The aim of the present study was to demonstrate proof-of-concept that candidate drug combinations could significantly inhibit growth and re-metastasis of this recalcitrant tumor. The patient's liver metastasis was initially established subcutaneously in nude mice and the subcutaneous tumor tissue was then orthotopically implanted in the liver of nude mice to establish a PDOX model. Two studies were performed to test different drugs or drug combination, indicating that 5-fluorouracil (5-FU) + irinotecan (IRI) + bevacizumab (BEV) and regorafenib (REG) + selumetinib (SEL) had significantly inhibited liver metastasis growth (p = 0.013 and p = 0.035, respectively), and prevented liver satellite metastasis. This study is proof of concept that a PDOX model of highly aggressive colon-cancer metastasis can identify effective drug combinations and that the model has future clinical potential.