Characterization of RNF43 frameshift mutations that drive Wnt ligand- and R-spondin-dependent colon cancer.

Loss-of-function mutations in RNF43 induce activation of Wnt ligand-dependent Wnt/ß-catenin signaling through stabilization of the Frizzled receptor, which is often found in microsatellite instability (MSI)-type colorectal cancer (CRC) that develops from sessile serrated adenomas. However, the mechanism underlying how RNF43 mutations promote tumorigenesis remains poorly understood. In this study, we established nine human CRC-derived organoids and found that three organoid lines carried RNF43 frameshift mutations associated with MSI-high and BRAFV600E mutations, suggesting that these CRCs developed through the serrated pathway. RNF43 frameshift mutant organoids required both Wnt ligands and R-spondin for proliferation, indicating that suppression of ZNRF3 and retained RNF43 function by R-spondin are required to achieve an indispensable level of Wnt activation for tumorigenesis. However, active ß-catenin levels in RNF43-mutant organoids were lower than those in APC two-hit mutant CRC, suggesting a lower threshold for Wnt activation in CRC that developed through the serrated pathway. Interestingly, transplantation of RNF43-mutant organoids with intestinal myofibroblasts accelerated the ß-catenin nuclear accumulation and proliferation of xenograft tumors, indicating a key role of stromal cells in the promotion of the malignant phenotype of RNF43-mutant CRC cells. Sequencing of subcloned organoid cell-expressed transcripts revealed that two organoid lines carried monoallelic RNF43 cis-mutations, with two RNF43 frameshift mutations introduced in the same allele and the wild-type RNF43 allele remaining, while the other organoid line carried two-hit biallelic RNF43 trans-mutations. These results suggest that heterozygous RNF43 frameshift mutations contribute to CRC development via the serrated pathway; however, a second-hit RNF43 mutation may be advantageous in tumorigenesis compared with a single-hit mutation through further activation of Wnt signaling. Finally, treatment with the PORCN inhibitor significantly suppressed RNF43-mutant cell-derived PDX tumor development. These results suggest a novel mechanism underlying RNF43 mutation-associated CRC development and the therapeutic potential of Wnt ligand inhibition against RNF43-mutant CRC. © 2022 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Partial Tracheal Defects Closure using Glutaraldehyde-Treated Autologous Pericardium.

BACKGROUND: The usefulness of autologous pericardium treated with glutaraldehyde (GA) for tracheal defect closure is unknown. This study preliminarily evaluated whether a GA-treated autologous pericardial graft can effectively close tracheal defects in a beagle model. METHODS: Defects of 10 mm × 10 mm were created on the trachea of 10 beagles and divided into a GA-treated group (n = 5), with tracheal reconstruction using GA-treated pericardium, and control group (n = 5), using fresh pericardium. Repair sites were evaluated through bronchoscopy and histology. Blood flows on graft were measured using laser Doppler technique on postoperative days (PODs) 0, 4, 7, 14, 28, and 56. Repair sites were histologically evaluated on POD 56. In addition, GA-treated pericardia of three other beagles were histologically evaluated 12 months postoperatively, for long-term follow-up. RESULTS: All animals survived; none developed anastomotic insufficiency. The mean suturing time and frequency of additional suture were significantly shorter and lower in the GA-treated group than in the control group (p = 0.002, 0.004). All animals in the control group exhibited graft contraction, whereas the GA-treated group healed with most graft residual and reepithelialization in the bronchoscopic and histological findings (p = 0.01, 0.004). Further, all long-term GA-treated pericardia of three beagles were confirmed as residual grafts with reepithelialization, without contraction, at 12 months postoperatively. Blood flows on graft using laser Doppler technique in the GA-treated group were detected at POD 14 or thereafter. CONCLUSION: GA-treated pericardium was easier to handle and provided favorable scaffolding, without graft contraction, compared with the nontreated pericardium at short- and long-term follow-up.

[Left Metastatic Lung Tumor for a Patient with Scimitar Syndrome:Report of a Case].

Scimitar syndrome is a subtype of partial anomalous pulmonary venous connection, a rare congenital disorder associated with hypoplasia of the right lung. In addition to the difficulty of isolated lung ventilation, resection of the left lung is associated with the risk of developing right heart failure due to increased right-to-left shunts. We report a case of a left lung metastasis of a patient with scimitar syndrome. The patient, a 58-year-old male, was diagnosed with scimitar syndrome at the age of 26 but had never experienced any symptoms. He underwent chemoradiotherapy for mid-pharynx carcinoma and achieved complete response. During follow-up, a nodule appeared in the lower lobe of the left lung. Since right heart catheterization revealed a pulmonary blood flow/systemic blood flow ratio (Qp/Qs) ratio of 2.6, intra-cardiac blood flow was diverted prior to pulmonary resection. Stanford type A acute aortic dissection occurred intra-operatively, and total aortic arch replacement was performed. Three months later, partial pulmonary resection was performed with extracorporeal membrane oxygenation (ECMO) on standby. As oxygenation was maintained by placing a blocker in the left lower lobe bronchus and ventilating the left upper lobe with high frequency jet ventilation, the operation was completed without using ECMO. The nodule was pathologically diagnosed as metastasis of mid-pharynx carcinoma. He did not develop heart failure and was discharged on post operated day 15.

[Right Atrial Blood Cyst with Patent Foramen Ovale:Report of a Case].

A woman in 70s was diagnosed with lung cancer, and a right atrial mass was discovered incidentally during preoperative examination by contrast-enhanced computed tomography (CT). Transesophageal echocardiography revealed a 20-mm, stemmed, spherical mass with low internal echogenicity and partially high echogenicity extending from the junction of the inferior vena cava to the posterior wall of the right atrium. Patent foramen ovale( PFO) was also confirmed. To avoid embolization and obtain diagnosis, the patient was referred for right atrial tumor resection. Cardiopulmonary bypass was established; the right atrial tumor was removed while the patient was in cardiac arrest. The tumor membrane was thin and easily ruptured, revealing jelly-like blood content and calcified mass. The patient recovered well after surgery and was discharged on day 15. According to the pathological examination, the tumor was a blood cyst. This is an extremely rare case of a blood cyst with PFO.

A method to identify pulmonary intersegmental planes with intravenous vitamin B2 injection.

PURPOSE: The present study investigated whether the pulmonary intersegmental planes could be identified with the intravenous injection of vitamin B2 using a fluorescent camera and whether this method can be used instead of the inflation-deflation technique or the intravenous indocyanine green (ICG) method. METHODS: In experiment 1, the vitamin B2 was intravenously injected to visualize the pulmonary intersegmental plane and perform segmentectomy, and the visualized pulmonary intersegmental line was then compared to the inflation-deflation line in six pigs. In experiment 2, using six pigs, the fluorescent area and duration of fluorescence were compared after the intravenous injection of vitamin B2 and ICG in the same animals. RESULTS: In all animals in experiment 1, it was possible to clearly detect yellow-green fluorescence in the lung, in segments other than the one intended for resection, for at least 60 min. Moreover, the line visualized with vitamin B2 fluorescence matched the inflation-deflation line in all animals. In experiment 2, the area of vitamin B2 fluorescence corresponded to the area of ICG fluorescence in each animal. CONCLUSIONS: The visualization of fluorescence after the intravenous injection of vitamin B2 using a fluorescent camera was a simple, safe, and accurate method for detecting intersegmental planes in a pig model. This method can be an alternative to the inflation-deflation technique and the intravenous ICG method.

[Perioperative Management for Cardiovascular Surgery on the Patients with Pulmonary Dysfunction].

The factors influencing the pulmonary function after cardiovascular surgery are decreased compliance of thorax due to sternotomy, phrenic nerve injury, wound pain and decreased blood flow after internal mammary artery harvest on coronary artery bypass grafting (CABG). Another factor is systemic inflammatory response syndrome (SIRS) associated with cardio-pulmonary bypass. So, we should take care of pulmonary function after surgery not only on the patients with pulmonary dysfunction but also on the patients with normal pulmonary function. Because the results after cardiovascular surgery for the patients with pulmonary dysfunction depends on the severity of the pulmonary function, preoperative assessment of it is important. The predictor for adverse results are chronic obstructive lung disease(COPD) itself and FEV1.0%<50% and so on. Even of the patients has no history of pulmonary disease, preoperative evaluation is necessary. For the patients with pulmonary dysfunction, we should consider fast-track recovery after operation, meaning early extubation, choice of less invasive surgery procedure and change of surgical procedure. Prohibition of smoking for more than 4 weeks, pre- and post-operatively pulmonary rehabilitation are also important for improve the operative results.

[Surgical Treatment of Pectus Excavatum in Patients with Marfan Syndrome Associated with Vertebral or Cardiovascular Disease].

Surgical treatment is often required in patients with Marfan syndrome presenting with scoliosis or cardioaortic disease. If these patients present with pectus excavatum, surgery for spinal deformity correction or chest wall closure during cardioaortic surgery can cause thoracic organ compression secondary to narrowing of the thorax resulting in hemodynamic and respiratory compromise. Cardiovascular complications serve as prognostic factors in patients with Marfan syndrome, and surgical treatment is often required in these cases. In our case series involving 4 patients, 2 patients with pectus excavatum and scoliosis underwent a Nuss procedure followed by safe and successful spinal correction surgery 6 months later. A Nuss procedure was also performed in a patient complicated with sinus of Valsalva dilatation, and thoracotomy was performed before cardioaortic surgery. Another patient with a complication of pectus excavatum and acute deterioration of cardiac status underwent concomitant repair with sternal elevation using an AO plate and cardioaortic surgery. In patients with Marfan syndrome presenting with pectus excavatum complicated by scoliosis or cardioaortic disease, it is necessary to consider concomitant or staged repair depending on the disease condition.

[Coil Embolization for an Aberrant Left Subclavian Artery Aneurysm with Kommerell's Diverticulum;Report of a Case].

A 67-year-old woman encountered a traffic accident and had chest computed tomography(CT) examination. It revealed a 24 mm Kommerell's diverticulum associated with a right-sided aortic arch and a 15 mm saccular aneurysm of an aberrant left subclavian artery. We performed intra-aneurysmal coil embolization for the left subclavian artery aneurysm after a balloon occlusion test of the left subclavian artery. The postoperative course was uneventful.

Clinical characteristics of spontaneous isolated visceral artery dissection.

OBJECTIVE: Spontaneous isolated visceral artery dissection (SIVAD) involving the celiac artery or superior mesenteric artery is rare, but it can be fatal. Given its rare incidence, the clinical characteristics of SIVAD are not fully understood. Therefore, the aim of this study was to investigate the clinical characteristics and prognosis of SIVAD. METHODS: We retrospectively reviewed 39 consecutive patients diagnosed with SIVAD from January 2007 to December 2016. Demographic characteristics, symptoms, vital signs, blood examination results, and computed tomography findings were retrieved through medical record review. RESULTS: The median age of the patients was 52 years; 94.9% were male, and 64.1% were symptomatic. Median follow-up duration was 11 months. Overall, hypertension (48.7%) and smoking (79.5%) were frequently observed. There were significant differences between symptomatic and asymptomatic patients in white blood cell count and creatine kinase level but not in fibrin degradation products or D-dimer level. There was a significant correlation between symptoms and length of dissection on computed tomography (P < .01). Conservative treatment was performed in 32 patients (82.1%), and only 7 patients required open surgery or intravascular intervention. Notably, the diameter of affected vessels decreased spontaneously with no rupture or symptom recurrence during follow-up, and mortality was 0% at both 30 days and 1 year. CONCLUSIONS: The utility of blood examination, especially for fibrin degradation products and D-dimer levels, for diagnosis of SIVAD is limited. A high index of suspicion is warranted in patients presenting with persistent severe abdominal pain. Conservative treatment should be considered first-line therapy in patients without any signs of bowel ischemia or rupture.

Occult constrictive pericardial disease emerging 40 years after chest radiation therapy: a case report.

BACKGROUND: The main etiology of constrictive pericarditis (CP) has changed from tuberculosis to therapeutic mediastinal radiation and cardiac surgery. Occult constrictive pericardial disease (OCPD) is a covert disease in which CP is manifested in a condition of volume overload. CASE PRESENTATION: A 60-year-old patient with a history of thoracic radiation therapy for non-Hodgkin's lymphoma (40 years earlier) was transferred to our hospital for treatment of repeated congestive heart failure. For a preoperative hemodynamic study, pre-hydration with intravenous normal saline (50 mL/hour) was used to manifest the pericardial disease and prevent contrast-induced nephropathy. The hemodynamic study showed a right ventricular dip-plateau pattern and discordance of right and left ventricular systolic pressures during inspiration, which was not seen in the volume-controlled state. These responses were concordant with OCPD. A pericardiectomy, aortic valve replacement, and mitral and tricuspid valve repair were performed. Postoperatively, the heart failure was controlled with standard medication. CONCLUSIONS: This case revealed a volume-induced change in hemodynamics in OCPD with severe combined valvular heart disease, which suggests the importance of considering OCPD in patients who had undergone radiation therapy 40 years before.

Analysis of Computational Fluid Dynamics and Particle Image Velocimetry Models of Distal-End Side-to-Side and End-to-Side Anastomoses for Coronary Artery Bypass Grafting in a Pulsatile Flow.

BACKGROUND: Intimal hyperplasia (IH) is a major cause of graft failure. Hemodynamic factors such as stagnation and disturbed blood flow are involved in IH formation. The aim of this study is to perform a comparative analysis of distal-end side-to-side (deSTS) and end-to-side (ETS) anastomoses using computational fluid dynamics (CFD) after validating the results via particle image velocimetry (PIV).Methods and Results:We investigated the characteristics of our target flow fields using CFD under steady and pulsatile flows. CFD via PIV under steady flow in a 10-times-actual-size model was validated. The CFD analysis revealed a recirculation zone in the heel region in the deSTS and ETS anastomoses and at the distal end of the graft, and just distal to the toe of the host artery in the deSTS anastomoses. The recirculation zone sizes changed with the phase shift. We found regions of low wall shear stress and high oscillating shear index in the same areas. The PIV and CFD results were similar. CONCLUSIONS: It was demonstrated that the hemodynamic characteristics of CFD and PIV is the difference between the deSTS and ETS anastomoses; that is, the deSTS flow peripheral to the distal end of the graft, at the distal end and just distal to the toe of the host artery is involved in the IH formation.

Overview of the 81st Annual Scientific Meeting of the Japanese Circulation Society　- Cardiovascular Medicine for the Next Generation.

The 81stAnnual Scientific Meeting of the Japanese Circulation Society was held in Kanazawa, Japan, on March 17-19, 2017 under a miraculously clear sky. The frontlines of healthcare and medicine are dramatically changing. Thus, "Cardiovascular Medicine for Next Generation" was chosen as the main theme of this meeting. The program was constructed around major identified issues, including renewal of our understanding of basic cardiovascular medicine, translational research, and preventive molecular medicine, all of which are anticipated to transcend the medical field over the next generation. Despite the provincial location, 15,672 participants, including more than 400 from overseas countries, attended the 3-day meeting, and there were in-depth discussions in the various sessions. In particular, to our great pleasure, Her Imperial Highness Princess Takamado kindly attended the opening ceremony and extended congratulations to us. The meeting successfully completed and we sincerely appreciate the great cooperation and support from all affiliates.

[Cardiac Surgery for Patients with Liver Cirrhosis].

Liver cirrhosis has emerged as a serious risk factor for cardiac surgery due to the higher mortality and morbidity that these patients display compared with the non-cirrhotic cardiac surgery population. Child-Pugh classification and model for end-stage liver disease score( MELD) score are useful to assess perioperative risk in patients with cirrhosis. According to recent research, cardiac surgery could be offered to patients with Child-Pugh A and a low MELD score with only mild increase in the risk of mortality. However, for patients with more advanced cirrhosis, risk of mortality is extremely high. To decrease mortality, careful patient selection, meticulous consideration of surgical strategy and perioperative treatment are vital for the recovery of cirrhotic patients.

[Utility of Partial Splenic Embolization Prior to Lung Resection in Patients Demonstrating Platelet Transfusion Refractoriness Due to Hypersplenism].

It is often difficult to control perioperative bleeding in patients with liver cirrhosis and concurrent thrombocytopenia and coagulation factor deficiency. Partial splenic embolization (PSE), an auxiliary treatment strategy in management of liver cirrhosis and hepatocellular carcinoma, can not only increase platelets but also improve liver function. With advances in interventional radiology, PSE is a safer and more reliable procedure compared to a splenectomy. We present the case of a 69-year-old man diagnosed with left lung cancer, with thrombocytopenia, and hepatitis C virus-related cirrhosis. Although he was administered prophylactic platelet transfusion prior to operation, he was noted to be refractory to platelet transfusion. PSE was performed to improve his thrombocytopenia, following which we could safely perform left upper lobectomy of the lung and ND2a-1 lymph node dissection without any major bleeding. PSE is useful induction therapy to provide a wider choice of treatment options for patients with thrombocytopenia.

[Congenital Bronchial Atresia Requiring Differentiation from Intralobar Sequestration].

We reported a case of bronchial atresia requiring differentiation from the intralobar sequestration. A 42-year-old man was referred to our institution with suspicion of intralobar sequestration, based on a 3-dimensional computed tomography (CT) angiography that showed abnormal blood vessels from the right inferior phrenic artery flowing into the right lower lobe. CT revealed a lesion between S9 and S10 wherein there were refluxed blood vessels from A9 without an accompanying bronchus, with polycysts and emphysematous changes. Ventilation-perfusion scintigraphy revealed a reduction in uptake in the same sites. He was diagnosed as congenital bronchial atresia preoperatively, and we performed a right basal segmentectomy. Pathological examination confirmed the bronchiectasis and emphysematous changes in the lung parenchyma, but malignant findings were not confirmed.

[A Recurrent Case of Thymic Adenocarcinoma Effectively Treated with S-1 Over a Long-Term Period].

A 61-year-old woman with an abnormal radiograph shadow in her anterior mediastinum was admitted to our hospital and underwent an extended thymectomy. The pathological diagnosis of the tumor was a non-papillary adenocarcinoma of the thymus in pathological stage IV b using the Masaoka classification owing to mediastinal lymph node metastasis. We found parasternal lymph node metastases 5 months after her first operation, and subsequently, she underwent surgery and adjuvant radiotherapy. We found systemic lymph node metastases and metastatic lesions in distant organs, including her lungs, brain, and kidney 27 months after her first operation. Systemic chemotherapy, such as carboplatin plus paclitaxel and an ADOC regimen were not very effective, so we performed immunohistochemical staining of the primary thymic adenocarcinoma. The levels of both thymidylate synthase and dihydropyrimidine dehydrogenase were low; therefore, we started S-1 100mg/body (2 weeks of administration, 1 week of withdrawal)31 months after her first operation. She entered complete remission 6 months after the initiation of S-1. We surgically resected her solitary lung metastasis 13 months after initiation of S-1, and then continued the S-1 treatment. There was no recurrence for more than 2 years after the lung surgery. We believe that when the expression levels of thymidylate synthase or dihydropyrimidine dehydrogenase are low in cases of recurrent thymic adenocarcinoma, S-1 may be able to induce an effective response.

Prognostic and predictive significance of long interspersed nucleotide element-1 methylation in advanced-stage colorectal cancer.

BACKGROUND: Hypomethylation of Long Interspersed Nucleotide Element-1 (LINE-1) is associated with worse prognosis in colorectal cancer (CRC). However, little is known about the relevance of this marker for the prognosis and response to chemotherapy of metastatic and recurrent (advanced-stage) CRC. Our aim was therefore to investigate whether tumor LINE-1 hypomethylation correlates with patient survival and with response to 5-fluorouracil (5-FU)/ oxaliplatin (FOLFOX) chemotherapy in advanced-stage CRC. METHODS: The study included 40 CRC patients who developed metastasis or local recurrence after surgery and subsequently underwent FOLFOX therapy. Progression-free and overall survival were estimated using the Kaplan-Meier method. LINE-1 methylation levels in formalin-fixed and paraffin-embedded primary tumor tissues were measured by MethyLight assay and correlated with patient survival. In vitro analyses were also conducted with human colon cancer cell lines having different LINE-1 methylation levels to examine the effects of 5-FU and oxaliplatin on LINE-1 activity and DNA double-strand-breaks. RESULTS: Patients with LINE-1 hypomethylation showed significantly worse progression-free (median: 6.6 vs 9.4 months; P = 0.02) and overall (median: 16.6 vs 23.2 months; P = 0.01) survival following chemotherapy compared to patients with high methylation. LINE-1 hypomethylation was an independent factor for poor prognosis (P = 0.018) and was associated with a trend for non-response to FOLFOX chemotherapy. In vitro analysis showed that oxaliplatin increased the LINE-1 score in LINE-1-expressing (hypomethylated) cancer cells, thereby enhancing and prolonging the effect of 5-FU against these cells. This finding supports the observed correlation between tumor LINE-1 methylation and response to chemotherapy in CRC patients. CONCLUSIONS: Tumor LINE-1 hypomethylation is an independent marker of poor prognosis in advanced-stage CRC and may also predict non-response to combination FOLFOX chemotherapy. Prospective studies are needed to optimize the measurement of tumor LINE-1 methylation and to confirm its clinical impact, particularly as a predictive marker.

Lymph node ratio as a prognostic factor in patients with pathological N2 non-small cell lung cancer.

BACKGROUND: The aim of this study was to investigate whether the lymph node ratio (LNR) was associated with the prognosis of patients, who underwent surgery for pathological N2 non-small cell lung cancer (NSCLC). METHODS: A total of 182 patients were diagnosed with pathological N2 disease and underwent complete resection surgeries with systematic lymphadenectomies. We counted the number of positives and removed lymph nodes to calculate a ratio between them (LNR). We also investigated the association between skip mediastinal lymph node metastasis and survival. RESULTS: Univariate analysis of survival in patients with N2 NSCLC showed that the T factor, clinical N factor, and LNR were significant prognostic factors. Multivariate analyses showed that the clinical N stage and LNR were significant independent prognostic factors for patients with pathological N2 NSCLC. Patients with a clinical lymph node status of 0 (cN0) and LNR ≤0.22 showed a significantly higher survival rate than patients with a cN1-2 and LNR ≥0.22 and 5-year survival rates were 47.1 and 10.3%, respectively (p < 0.0001). CONCLUSIONS: LNR is an important prognostic factor for poor outcome following surgery in patients with N2 disease. The combination of the LNR and cN status provides a valuable prognostic tool.