[Migration of Internal Pancreaticojejunostomy Stents into the Bile Ducts in Patients Undergoing Pancreaticoduodenectomy].

The patient was a 68-year-old male. Pancreaticoduodenectomy(PD)for papillary carcinoma was performed. Computed tomography(CT)3 months after surgery revealed the migration of a lost Pit-stent into the bile duct. However, there were no symptoms. On CT 2 years after surgery, the lost stent had spontaneously fallen off. However, hepaticolithiasis was observed, and lithotripsy was performed using endoscopic retrograde cholangiopancreatography(ERCP). A pancreatic fistula after PD is an important complication. To prevent pancreatic fistulae, pancreatic stenting at the site of PD is performed in many cases. The postoperative in vivo kinetics of a lost stent remains to be clarified. Several case reports on complications have been published. In this study, we report a patient in whom the migration of a lost Pit-stent into the intrahepatic bile duct after PD led to hepaticolithiasis, and review the literature.

Chylothorax following transsternal total thymectomy: a case report.

Herein, we report a case of chylothorax following total thymectomy. A 46-year-old woman having an anterior mediastinal tumor underwent a thymectomy via median sternotomy. Seven days after surgery, there was no massive pleural effusion. However, on post-operative day 17, a right massive pleural effusion was detected, and it was diagnosed as chylothorax. She was successfully treated with conservative therapy. Chylothorax following thymectomy is a very rare complication.

[A Patient with Small Intestinal Leiomyosarcoma and Intussusception Who Underwent Single Port Surgery].

The patient was a 33-year-old female. She was referred to our hospital from a previous clinic with abdominal pain and vomiting. Contrast-enhanced abdominal CT revealed intussusception, leading to a diagnosis of intussusception with a small intestinal tumor as an advanced part. Intestinal obstruction symptoms were observed, and emergency surgery was performed on the same day. As a technique, single port surgery was selected, and laparoscopic reduction was attempted. However, it was ineffective. The site of intussusception was induced outside the body through a small laparotomy wound, and reduction was performed using Hutchinson's procedure. As an adjacent lymph node was markedly swollen, the mesentery involving this lymph node was dissected in a fan shape, and the tumor was extirpated. The tumor measured 40 mm in long diameter, being a hemicircular, protruding lesion. Histologically, disarray of short spindle tumor cells was observed. Immunostaining showed Kit- and DOG1-negtive reactions and partially α-SMA and desmin-positive reactions, suggesting leiomyosarcoma. With the establishment of an immunostaining-test-based classification, leiomyosarcoma is currently rare. In this study, we report a patient in whom single port surgery for intussusception related to small intestinal leiomyosarcoma was successful.

[A Case of Preoperatively Diagnosed Early Cystic-Duct Carcinoma].

A 88-year-old man presented with abdominal discomfort. Computed tomography(CT)images showed gallbladder tumor, and the patient was referred to our hospital. In addition to the above, CT images showed a tense gallbladder and EUS showed papillary raised lesions mainly from the cystic duct to the gallbladder neck. Based on the above, we diagnosed cystic duct cancer and performed full-thickness cholecystectomy, extrahepatic bile duct resection, regional lymph node dissection at our department. Macroscopic findings of the resected specimen showed a Villous ridge in the cystic duct. Histopathological findings revealed well-differentiated adenocarcinoma with an irregular papillary structure centered on the cystic duct. The depth of invasion remained within the epithelium, and a diagnosis of primary early cystic duct cancer was made. Primary cystic duct cancer is a relatively rare disease and often does not lead to preoperative diagnosis. This time, we experienced a case in which cystic duct cancer was diagnosed preoperatively due to complaints of abdominal discomfort and could be surgically resected.

[A Case of Small Intestinal GIST Diagnosed by Intussusception].

The patient was a 34-year-old female. She consulted our hospital with epigastric pain. Abdominal computed tomography (CT)revealed a small intestinal tumor, measuring 30 mm in diameter, with contrast effects. For detailed examination, enteroscopy was scheduled, but abdominal pain suddenly occurred. CT showed marked dilatation of the small intestine and intussusception, and emergency surgery was performed on the same day. Intussusception was observed on the anal side 70 cm from Treitz' ligament. The intestinal wall was black, and fissures of the serosa were partially noted. It was difficult to release the intussusception, and a 55 cm area of the jejunum involving the site of intussusception was resected. The patient was discharged on the 8th postoperative day. At the tip of the intussusception, a submucosal tumor measuring 25 mm in maximum diameter was present. Pathologically, the proliferation of spindle-shaped cells originating from the muscularis propria was observed, comprising an intricate structure. On immunostaining, KIT-positive and CD34, S-100, α-SMA-negative reactions were detected, leading to the diagnosis of a gastrointestinal stromal tumor(GIST). Nuclear divisions were noted in <5/50 visual fields. According to the risk classification, the risk was evaluated as low. The patient is being followed-up in accordance with guidelines.

[Patient with Monomorphic Epitheliotropic Intestinal T-Cell Lymphoma with Small Intestinal Perforation Development during Chemotherapy].

Monomorphic epitheliotropic intestinal T-cell lymphoma(MEITL)is classified under type Ⅱ enteropathy-associated T-cell lymphoma(EATL). It is a rare disease with a low incidence rate. This study reports a case of a patient with MEITL who developed small intestinal perforation during chemotherapy. The patient was a 55-year-old woman who presented to a previous clinic with epigastric pain. Enteroscopy results showed a map-like ulcer in the jejunum. Examination of the tissue specimen collected from this site suggested T-cell lymphoma. The patient was referred to our hospital for chemotherapy. Seven days following the initiation of chemotherapy, an abdominal computed tomography(CT)revealed free air, leading to a diagnosis of gastrointestinal perforation. Emergency surgery was performed. Intraoperatively, bowel perforation and a degenerative ulcer were observed at 95 cm and 80 to 115 cm from the Treitz' ligament, respectively. In addition, all-layer intestinal necrosis was noted 150 and 90 cm from the terminal ileum. Total resection and anastomosis were performed. Postoperatively, the patient developed sepsis due to chemotherapy-related pancytopenia but recovered. She was discharged on postoperative day 24. Subsequently, positron emission tomography(PET)-CT revealed residual intestinal tumor cells and peritoneal dissemination. Chemotherapy was initiated, but there was no response. The patient died after 6.5 months. A radical treatment for MEITL has not yet been established. More case reports are needed to improve the prognosis of this disease.

Cell Tracking Suggests Pathophysiological and Therapeutic Role of Bone Marrow Cells in Sugen5416/Hypoxia Rat Model of Pulmonary Arterial Hypertension.

BACKGROUND: The mechanism of vascular remodelling in pulmonary arterial hypertension (PAH) remains unclear. Hence, defining the origin of cells constituting intractable vascular lesions in PAH is expected to facilitate therapeutic progress. Herein, we aimed to evaluate the origin of intractable vascular lesions in PAH rodent models via bone marrow (BM) and orthotopic lung transplantation (LT). METHODS: To trace BM-derived cells, we prepared chimeric rats transplanted with BM cells from green fluorescent protein (GFP) transgenic rats. Male rats were transplanted with lungs obtained from female rats and vice versa. Pulmonary hypertension was induced in the transplanted rats via Sugen5416 treatment and subsequent chronic hypoxia (Su/Hx). RESULTS: In the chimeric Su/Hx models, GFP-positive cells were observed in the pulmonary vascular area. Moreover, the right ventricular systolic pressure was significantly lower compared with wild-type Su/Hx rats without BM transplantation (P = 0.009). PAH suppression was also observed in rats that received allograft transplanted BM transplantation. In male rats that received LT and Su/Hx, BM-derived cells carrying the Y chromosome were also detected in neointimal occlusive lesions of the transplanted lungs received from female rats. CONCLUSIONS: BM-derived cells participate in pulmonary vascular remodelling in the Su/Hx rat model, whereas BM transplantation may contribute to suppression of development of PAH.

Preoperative soluble cluster of differentiation 40 ligand level is associated with outcome of pulmonary endarterectomy.

Objective: Soluble CD40 ligand (sCD40L) is associated with some pathobiological states. However, whether sCD40L in patients with chronic thromboembolic pulmonary hypertension (CTEPH) who underwent pulmonary endarterectomy (PEA) is associated with perioperative pulmonary hemodynamics and surgical outcomes has not been elucidated. Here we aimed to investigate whether sCD40L is a useful serologic biomarker of poor surgical outcome of PEA in patients with CTEPH. Methods: Ninety patients with CTEPH who underwent PEA were enrolled. Independent preoperative parameters were examined, including sCD40L related to lower cardiac index (CI), higher pulmonary vascular resistance (PVR), and poor surgical outcomes after PEA, according to the multivariate logistic regression analysis. In addition, the area under the curve (AUC) value of sCD40L to predict poor surgical outcomes was compared with the AUCs of D-dimer and C-reactive protein (CRP). The generalizability of this study model was tested by a 5-fold cross-validation analysis. Results: Multivariate logistic regression analysis showed that high sCD40L level was related to postoperative lower CI, higher PVR, and poor surgical outcomes independent of other preoperative parameters. The AUC value of sCD40L to predict poor surgical outcomes was higher than those of D-dimer and CRP. A sCD40L cutoff value of 1.45 ng/mL predicted poor surgical outcomes with 79.3% sensitivity and 67.3% specificity. The 5-fold cross-validation analysis showed the effectiveness of our model's performance. Conclusions: Preoperative sCD40L level could be a promising serologic biomarker associated with poor surgical outcomes in CTEPH. In addition to known preoperative parameters, the biomarker might have the potential to identify patients at high risk of PEA, thereby reducing the mortality rates.

[An Early Gastric Cancer with Sarcoid Reactions of the Regional Lymph Nodes].

The patient was a 73-year-old male who was referred to our hospital for detailed examination because computed tomography(CT)revealed lymph node swelling. Upper gastrointestinal endoscopy revealed a 0-Ⅱc lesion in the greater curvature of the middle gastric body. The periphery of the lesion site was not reached using endoscopy. CT revealed lymph node swelling, but positron emission tomography(PET)-CT did not show abnormal accumulation in any area other than the lesion site involving the lymph nodes. Under a diagnosis of cT2N0M0, Stage Ⅰ tumor, total gastrectomy via laparotomy and lymph node dissection(D2+No.10)was performed. The histopathological diagnosis suggested early gastric cancer pT1b (SM)N0M0, Stage ⅠA. Although lymph node metastasis was not observed, the outgrowth of non-caseating epithelioid cell granulomas was observed in all lymph nodes. There was no granulomatous lesion at any other site, including the lung, leading to a diagnosis of sarcoid reactions. The"sarcoid reaction"refers to non-caseating epithelioid cell granuloma formation in a local area or the regional lymph nodes of a malignant tumor through reactions to extraneous foreign bodies in the absence of the general condition or signs as sarcoidosis. Sarcoid reactions to early gastric cancer are rare. In this study, we report a patient with early gastric cancer who showed sarcoid reactions of the regional lymph nodes and review the literature.

[A Case of Elective Laparoscopic Resection for Sigmoid Colon Cancer with Irreducible Intussusception].

An 85-year-old man was hospitalized for a right greater trochanteric fracture. Rectal intussusception was found by diagnostic imaging but left untreated because of minor gastrointestinal symptoms. As a result of work-up for persistent mucous stool, he was diagnosed with sigmoid colon cancer with intussusception. The intussusception could not be reduced during barium enema examination but could undergo elective laparoscopic surgery with a good postoperative course. Adult intussusception may be asymptomatic and require no emergency treatment. In such a case, elective surgery can be performed. Many facilities employ laparotomy as a standard of care for intussusception. With the recent technological advances in endoscopic surgeries, laparoscopic surgery can be considered as a treatment option.

[A Case of Goblet Cell Carcinoid].

The patient was a 26-year-old female who had undergone conservative treatment for acute appendicitis at another clinic and was referred to our hospital for interval appendectomy. We performed a single-incision laparoscopic appendectomy, and the patient was diagnosed with goblet cell carcinoid(GCC)based on the postoperative pathological examination. Since GCC is considered a high-grade tumor, we performed a laparoscopic ileocolic resection with D3 lymphadenectomy. There was no residual disease or lymph node metastasis detected in the resected specimen. Patients with advanced GCC typically have poor prognosis, because GCC is characterized by peritoneal dissemination and lymph node metastasis. However, our findings suggested that an additional laparoscopic surgery could be one of the curative and safe treatment options for selected pa- tients with GCC.

Direct Experimental Evidence for Markedly Enhanced Surface Proton Activity Inherent to Water Ice.

Autoionization and subsequent proton transfer processes determine the proton activity inherent to water molecular systems. In this study, we provide direct experimental evidence that the proton activity is markedly enhanced at the surface of crystalline ice, on the basis of the simultaneous observation of H/D exchange of water molecules at the surface and in the interior of well-defined double-layer ice films composed of H2O and D2O. Thermal desorption mass spectrometry showed clear signatures derived from the surface H/D exchange equilibrium, whereas infrared absorption spectroscopy indicated no appreciable H/D exchange progress in the interior. Detailed kinetic analyses revealed that the rate of H/D exchange at the surface is at least 3 orders of magnitude higher than in the interior. This drastic enhancement of the proton activity suggests an extremely high concentration of surface-hydrated protons in comparison with those in the bulk. Our results also highlight the impact of the local hydrogen-bond structure on the autoionization of water molecules.

Thickness dependent homogeneous crystallization of ultrathin amorphous solid water films.

The crystallization mechanism and kinetics of amorphous materials are of paramount importance not only in basic science but also in the application field because they are closely related to their thermal stability. In the case of amorphous nanomaterials, thermal stability distinctively different from that of bulk materials often emerges. Despite intensive studies in the past, a thorough understanding of the stability at the molecular level has not been reached particularly on how crystallization processes depend on size and are influenced by their surface and interface. In this article, we report the film-size-dependent crystallization of thermally relaxed nonporous ASW ultrathin films on a Pt(111) surface as a benchmark system of amorphous molecular films. The crystallization processes at the surface and interior of the ASW ultrathin films are monitored simultaneously with thermal desorption and infrared reflection absorption, respectively, as a function of the film thickness. Here, we demonstrate that the crystallization is initiated solely by "homogeneous nucleation" irrespective of the film thickness while the crystallization rate remarkably depends on the thickness; the rate of 5-layer (∼1.5 nm) ASW films is one order of magnitude higher than that of 20-layer (∼6 nm) films. Moreover, we found a clear correlation between the film-thickness-dependent crystallization kinetics and microscopic structural disorder associated with the broad distribution of hydrogen-bond lengths between water molecules.

[Resection of Synchronous Liver Metastasis from Ascending Colon Cancer with Aplastic Anemia-A Case Report].

The aplastic anemia(AA)syndrome is characterized by pancytopenia and bone marrow hypoplasia. Although anemia, bleeding tendency, and susceptibility to infection are issues of concern during surgery, few reports have been published on the perioperative management, and management methods have not been established. A 77-year-old woman visited our hospital with chief complaints of melena and fatigability. Marked pancytopenia was observed at the first visit. After a detailed examination, she was diagnosed with ascending colon cancer accompanied by AA and solitary liver metastasis. As AA responded poorly to treatment, without improvement in pancytopenia, we decided to perform colectomy. The perioperative management, including blood transfusion and administration of a G-CSF preparation, was performed in collaboration with a hematologist, followed by right hemicolectomy and hepatic lateral segmentectomy. She was transferred to the department of hematology on hospital day 8 without complications. In conclusion, a highly invasive surgery, as in the present case, can be performed safely with an appropriate perioperative management even in cases complicated by AA.

[A Case of Mesenteric Undifferentiated Pleomorphic Sarcoma].

Undifferentiated pleomorphic sarcoma develops in adult soft tissues and has a poor prognosis. It often recurs in the limbs and trunk, but is rare in the mesentery. Complete resection of the tumor is the first-line treatment, and there are previously reported cases of the usefulness of chemotherapy and radiation therapy; however, several factors remain to be clarified. We report a case of undifferentiated pleomorphic sarcoma originating in the ascending mesocolon.

Protective role of endothelial progenitor cells stimulated by riociguat in chronic thromboembolic pulmonary hypertension.

BACKGROUND: Pulmonary endothelial damage has a negative impact on the maintenance of normal pulmonary vascular function. Such damage results in delayed thrombus dissolution and vascular remodeling in chronic thromboembolic pulmonary hypertension (CTEPH). Although endothelial progenitor cells (EPCs) may be incorporated into neovasculature during vascular repair, their function in CTEPH remains unclarified, especially under the augmentation of soluble guanylate cyclase (sGC) activity. METHODS AND RESULTS: We evaluated the effect of EPCs on endothelial function and compared the effect of riociguat, a sGC stimulator, on the number and function of circulating EPCs in two groups of CTEPH patients. The two groups consisted 16 CTEPH patients who were treatment naïve (Naïve group), and 14 CTEPH patients who were being treated with riociguat, a sGC stimulator (Riociguat group). The number of circulating EPCs in the Riociguat group was significantly higher than that in the Naïve group. Gene expression levels associated with angiogenesis were significantly higher in EPCs of the Riociguat group. EPC-stimulated tube formation and migration of human pulmonary microvascular endothelial cell (hPMVEC) in the Riociguat group exceeded that in the Naïve group. The angiogenic ability of hPMVECs stimulated by EPCs in the Riociguat group was enhanced compared to that of the sGC stimulator, BAY 41-2272. CONCLUSION: These findings indicate that riociguat may induce EPCs to play a protective role via modulation of endothelial functions associated with CTEPH. TRANSLATION ASPECT OF THE WORK: Endothelial dysfunction exacerbates CTEPH. Riociguat enhanced the protective role of EPCs via neovascularization, which prevented vascular remodeling and alleviated CTEPH.

[Spontaneous Disappearance of Undifferentiated Pleomorphic Primary Mesenteric Sarcoma-A Case Report].

The patient was a 49-year-old man with persistent fever since the introduction of hemodialysis(HD). Vomiting and abdominal swelling appeared 4 months after initiating hemodialysis. Computed tomography(CT)scan revealed a tumor measuring 9 cm, and disorders of passage from the jejunum. Surgery was performed, and resection was impossible because of peritoneal dissemination. Histopathological examination of the disseminated nodes suggested an undifferentiated pleomorphic sarcoma. Postoperatively, drainage from the gastric fistula was approximately 2,000mL/day. Chemotherapy was considered impossible because of HD, and palliative therapy was selected. However, the volume of drainage from the gastric fistula gradually decreased, and the disorders of passage reduced. CT scan confirmed marked reduction in the size of the intraperitoneal tumor and its subsequent disappearance. At the 2-year-and-5-month postoperative follow-up, no relapses were observed, and the course had been uneventful. Undifferentiated pleomorphic sarcomas develop in the soft tissue of adults and have a poor prognosis. However, mesenteric development is rare. Total tumorectomy is the first choice of treatment. A consensus on the usefulness of chemotherapy or radiotherapy has not been reached. Furthermore, no studies have reported spontaneous tumor disappearance in the absence of treatment. Here, we report a case of minor undifferentiated primary mesenteric sarcoma and its spontaneous disappearance and review the literature.

A combination of MTAP and BAP1 immunohistochemistry is effective for distinguishing sarcomatoid mesothelioma from fibrous pleuritis.

OBJECTIVES: Histologic diagnosis of malignant pleural mesothelioma (MPM) is not always straightforward. Loss of BRCA1-associated protein 1 (BAP1) expression as detected by immunohistochemistry (IHC) (BAP1 IHC) and homozygous deletion (HD) of 9p21 as detected by fluorescencein situ hybridization (FISH) (9p21 FISH) are effective for distinguishing malignant mesothelial proliferation from benign proliferation. We have previously reported that immunohistochemical expression of the protein product of the methylthioadenosine phosphorylase (MTAP) gene, which is localized in the 9p21 chromosomal region, is correlated with the deletion status of 9p21 FISH in MPM tissues. In this study, we investigated whether a combination of MTAP and BAP1 IHC could distinguish sarcomatoid MPM from fibrous pleuritis. MATERIALS AND METHODS: We examined IHC expressions of MTAP and BAP1 and 9p21 FISH in sarcomatoid/desmoplastic (n = 18) and biphasic MPM (n = 12) and in fibrous pleuritis (n = 17). In biphasic MPM, only sarcomatoid components were evaluated for IHC and FISH. The sensitivity and specificity of each detection assay for discriminating MPM cases from fibrous pleuritis was determined. In addition, we compared the IHC expression of MTAP with the deletion status of 9p21 FISH. RESULTS: MTAP IHC and BAP1 IHC showed 80% and 36.7% sensitivity, respectively, and both showed 100% specificity in differentiating MPM from fibrous pleuritis. A combination of MTAP and BAP1 IHC yielded greater sensitivity (90%) than that detected for MTAP IHC alone or BAP1 IHC alone. Moreover, a high degree of concordance was observed between the results of MTAP IHC and HD of 9p21 FISH (κ = 0.63). CONCLUSIONS: With an accurate interpretation of results, combined MTAP and BAP1 IHC is a reliable and effective method for distinguishing sarcomatoid MPM from fibrous pleuritis.

Long-Term Outcome of Chronic Thromboembolic Pulmonary Hypertension at a Single Japanese Pulmonary Endarterectomy Center.

BACKGROUND: Several new treatments for chronic thromboembolic pulmonary hypertension (CTEPH) have appeared in recent years, which have led to changes in the treatment algorithm. Changes in survival rates and prognostic factors, however, have not been estimated so far.Methods and Results:Two hundred and eighty patients were diagnosed with CTEPH at Chiba University Hospital between June 1986 and June 2016. Survival rate was investigated by date of treatment initiation (group 1, 1986-1998; group 2, 1999-2008; group 3, 2009-2016). Survival rates were also evaluated by treatment strategy: balloon pulmonary angioplasty (BPA), pulmonary endarterectomy (PEA), and medical treatment. Group 3 had significantly better disease-specific survival than groups 1 and 2 (5-year survival: 91.9% vs. 67.1%, 77.0%, respectively). For the non-PEA (BPA+medication) strategy, group 3 had better disease-specific survival than groups 1 and 2 (5-year survival: 94.9% vs. 54.6%, 74.2%, respectively). The PEA strategy had significantly better survival than the medication strategy in groups 1 and 2, whereas no difference was observed between the BPA, PEA, and medication strategies in group 3. CONCLUSIONS: Survival in CTEPH in the recent era has significantly improved, especially in non-PEA patients. BPA and selective pulmonary vasodilators could improve survival in the non-PEA group. In the present study, no difference in survival was found between PEA and non-PEA.