10 research outputs found

    AQT-D: Demonstration of the Water Resistojet Propulsion System by the ISS-Deployed CubeSat

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    AQT-D (AQua Thruster-Demonstrator) is a 3U CubeSat for a demonstration of a water resistojet propulsion system developed by The University of Tokyo. AQT-D installed the 1U propulsion system using water as a propellant, named AQUARIUS-1U (AQUA ResIstojet propUlsion System 1U). We completed the design and assembly of the AQT-D flight model. AQUARIUS-1U was fired on a pendulum-type thrust balance, and its performance was directly characterized in both a stand-alone test and an integrated test using an entire spacecraft system. AQT-D is currently scheduled to be delivered to JAXA in July 2019 and launched to the International Space Station (ISS) in the middle of 2019 by the H-IIB rocket. AQT-D will be deployed from the Japanese Experiment Module (JEM), known as Kibo, and demonstrate water propulsion technology

    Three-stage laparoscopic surgery in a morbidly obese patient with Hinchey III diverticulitis: a case report

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    Abstract Background Perforated diverticulitis with purulent peritonitis (Hinchey III diverticulitis) has traditionally been treated with a Hartmann’s procedure in order to avoid the considerable postoperative morbidity and mortality associated with one-stage resection and primary anastomosis. Although there have been reports regarding laparoscopic lavage as the initial treatment of perforated Hinchey III diverticulitis, a formal treatment strategy has not been established yet. We performed a three-stage surgery, including laparoscopic lavage and drainage with diverting ileostomy (first stage), laparoscopic sigmoidectomy (second stage), and ileostomy closure (third stage) in a morbidly obese patient with Hinchey III diverticulitis. Case presentation A 31-year-old man who presented with abdominal pain was diagnosed with perforated diverticulitis and sent to our hospital for evaluation. He had morbid obesity (body mass index (BMI) 50 kg/m2), acute renal failure, and uncontrolled diabetes. We performed an emergency operation including laparoscopic lavage and drainage with a diverting ileostomy for this case of Hinchey III diverticulitis. Fifteen months after the first-stage surgery, we performed laparoscopic sigmoidectomy as the second stage. Finally, 5 months later, we performed ileostomy closure. The patient recovered without significant complications. Conclusion Three-stage surgery including early laparoscopic lavage and proximal diversion for morbidly obese, comorbid patients with Hinchey III diverticulitis may be indicated in the acute phase to avoid perioperative complications and permanent colostomy creation

    Successful subtotal gastrectomy and hepatectomy for HER2-positive gastric cancer with liver metastasis after trastuzumab-based chemotherapy: a case report

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    Abstract Background Conversion surgery (CS) after chemotherapy is weakly recommended as a promising tool for improving prognoses in patients with unresectable gastric cancer. Moreover, several investigators have demonstrated the clinical efficacy of subtotal gastrectomy (sTG) with a small remnant stomach for the nutritional status and surgical outcome compared with total gastrectomy. Here, we report a patient with liver metastasis from human epidermal growth factor receptor 2 (HER2)-positive gastric cancer who underwent sTG and hepatectomy after trastuzumab-based chemotherapy. Case presentation An 84-year-old male patient was diagnosed with HER2-positive gastric cancer with a single liver metastasis. He was treated with eight courses of trastuzumab in combination with S-1 and oxaliplatin as first-line chemotherapy. The primary tumor and liver metastasis shrank significantly. The metastatic liver lesion’s reduction rate was 65%. According to the Response Evaluation Criteria in Solid Tumors, the patient had a partial response. Therefore, he underwent an sTG with D2 lymphadenectomy and partial hepatectomy of segment 2. Histopathological examination revealed a grade 3 histological response without lymph node metastases from the primary tumor. No viable cancer cells were observed in the resected liver specimens. The patient received adjuvant chemotherapy with S-1. The postoperative quality of life (QOL) evaluated using the Postgastrectomy Syndrome Assessment Scale-45 was maintained, and the patient was still alive 8 months after the CS without recurrence. Conclusions An sTG with a small remnant stomach might be clinically useful for preventing a decline in QOL and improving prognoses in patients with stage IV gastric cancer after chemotherapy

    Potential association of LOXL1 with peritoneal dissemination in gastric cancer possibly via promotion of EMT.

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    BackgroundPeritoneal dissemination (PD) frequently occurs in gastric cancer (GC) and is incurable. In this study, we aimed to identify novel PD-associated genes and clarify their clinical and biological significance in GC.Materials and methodsWe identified LOXL1 as a PD-associated candidate gene by in silico analysis of GC datasets (highly disseminated peritoneal GC cell line and two freely available GC datasets, GSE15459 and TCGA). Next, we evaluated the clinical significance of LOXL1 expression using RT-qPCR and immunohistochemistry staining (IHC) in a validation cohort (Kyushu cohort). Moreover, we performed gene expression analysis, including gene set enrichment analysis (GSEA) with GSE15459 and TCGA datasets. Finally, we performed a series of in vitro experiments using GC cells.ResultsIn silico analysis showed that LOXL1 was overexpressed in tumor tissues of GC patients with PD and in highly disseminated peritoneal GC cells, relative to that in the control GC patients and cells, respectively. High expression of LOXL1 was a poor prognostic factor in the TCGA dataset. Next, IHC showed that LOXL1 was highly expressed in GC cells. High LOXL1 mRNA expression was associated with poorly differentiated histological type, lymph node metastasis, and was an independent poor prognostic factor in the Kyushu validation cohort. Moreover, LOXL1 expression was positively correlated with the EMT (epithelial-mesenchymal transition) gene set in GSEA. Finally, LOXL1-overexpressing GC cells changed their morphology to a spindle-like form. LOXL1 overexpression reduced CDH1 expression; increased the expression of VIM, CDH2, SNAI2, and PLS3; and promoted the migration capacity of GC cells.ConclusionsLOXL1 is associated with PD in GC, possibly through the induction of EMT

    N-Cadherin mRNA Levels in Peripheral Blood Could Be a Potential Indicator of New Metastases in Breast Cancer: A Pilot Study

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    Background: There is growing evidence that patients with metastatic breast cancer whose disease progresses from a new metastasis (NM) have a worse prognosis than that of patients whose disease progresses from a pre-existing metastasis. The aim of this pilot study is to identify a blood biomarker predicting NM in breast cancer. Methods: The expression of epithelial (cytokeratin 18/19) or mesenchymal (plastin-3, vimentin, and N-cadherin) markers in the peripheral blood (PB) of recurrent breast cancer patients undergoing chemotherapy with eribulin or S-1 was measured over the course of treatment by RT-qPCR. The clinical significance of preoperative N-cadherin expression in the PB or tumor tissues of breast cancer patients undergoing curative surgery was assessed by RT-qPCR or using public datasets. Finally, N-cadherin expression in specific PB cell types was assessed by RT-qPCR. Results: The expression levels of the mesenchymal markers N-cadherin and vimentin were high in the NM cases, whereas that of the epithelial marker cytokeratin 18 was high in the pre-existing metastasis cases. High preoperative N-cadherin expression in PB or tumor tissues was significantly associated with poor recurrence-free survival. N-cadherin was expressed mainly in polymorphonuclear leukocytes in PB. Conclusion: N-cadherin mRNA levels in blood may serve as a novel prognostic biomarker predicting NM, including recurrence, in breast cancer patients

    Impaired tumor immune response in metastatic tumors is a selective pressure for neutral evolution in CRC cases.

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    A Darwinian evolutionary shift occurs early in the neutral evolution of advanced colorectal carcinoma (CRC), and copy number aberrations (CNA) are essential in the transition from adenoma to carcinoma. In light of this primary evolution, we investigated the evolutionary principles of the genome that foster postoperative recurrence of CRC. CNA and neoantigens (NAG) were compared between early primary tumors with recurrence (CRCR) and early primary tumors without recurrence (precancerous and early; PCRC). We compared CNA, single nucleotide variance (SNV), RNA sequences, and T-cell receptor (TCR) repertoire between 9 primary and 10 metastatic sites from 10 CRCR cases. We found that NAG in primary sites were fewer in CRCR than in PCRC, while the arm level CNA were significantly higher in primary sites in CRCR than in PCRC. Further, a comparison of genomic aberrations of primary and metastatic conditions revealed no significant differences in CNA. The driver mutations in recurrence were the trunk of the evolutionary phylogenic tree from primary sites to recurrence sites. Notably, PD-1 and TIM3, T cell exhaustion-related molecules of the tumor immune response, were abundantly expressed in metastatic sites compared to primary sites along with the increased number of CD8 expressing cells. The postoperative recurrence-free survival period was only significantly associated with the NAG levels and TCR repertoire diversity in metastatic sites. Therefore, CNA with diminished NAG and diverse TCR repertoire in pre-metastatic sites may determine postoperative recurrence of CRC

    High Pretreatment Mean Corpuscular Volume Can Predict Worse Prognosis in Patients With Esophageal Squamous Cell Carcinoma who Have Undergone Curative Esophagectomy

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    Objective:. To establish the prognostic value of mean corpuscular volume (MCV) in patients with esophageal squamous cell carcinoma (ESCC) who have undergone esophagectomy. Background:. The MCV increases in patients with high alcohol and tobacco consumption. Such a lifestyle can be a risk factor for malnutrition, comorbidities related to those habits, and multiple primary malignancies, which may be associated with frequent postoperative morbidity and poor prognosis. Methods:. This study included 1673 patients with ESCC who underwent curative esophagectomy at eight institutes between April 2005 and November 2020. Patients were divided into normal and high MCV groups according to the standard value of their pretreatment MCV. Clinical background, short-term outcomes, and prognosis were retrospectively compared between the groups. Results:. Overall, 26.9% of patients had a high MCV, which was significantly associated with male sex, habitual smoking and drinking, multiple primary malignancies, and malnutrition, as estimated by the body mass index, hemoglobin and serum albumin values, and the Geriatric Nutritional Risk Index. Postoperative respiratory morbidity (P = 0.0075) frequently occurred in the high MCV group. A high MCV was an independent prognostic factor for worse overall survival (hazard ratio, 1.27; 95% confidence interval, 1.049–1.533; P = 0.014) and relapse-free survival (hazard ratio, 1.23; 95% confidence interval, 1.047–1.455; P = 0.012). Conclusions:. A high MCV correlates with habitual drinking and smoking, malnutrition, and multiple primary malignancies and could be a surrogate marker of worse short-term and long-term outcomes in patients with ESCC who undergo esophagectomy
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