30 research outputs found

    Ruthenium-catalysed Z-selective cross metathesis of allylic-substituted olefins

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    The Z-selective cross metathesis of allylic-substituted olefins is explored with recently developed ruthenium-based metathesis catalysts. The reaction proceeds with excellent stereoselectivity for the Z-isomer (typically >95%) and yields of up to 88% for a variety of allylic substituents. This includes the first synthesis of Z-α,β-unsaturated acetals by cross metathesis and their elaboration to Z-α,β-unsaturated aldehydes. In addition, the reaction is tolerant of a variety of cross partners, varying in functionality and steric profile

    New ruthenium-​based catalysts for Z-​selective metathesis of hindered olefins

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    A series of new ruthenium-based metathesis catalysts with varying N-heterocyclic carbene (NHC) substituents and their reactivity toward hindered olefins are reported. Through systematic variation of the sterics and electronics of the NHC substituents, metathesis activity and Z-selectivity are related to structure, resulting in catalysts that perform cross metathesis of a wide variety of allylic-substituted olefins in high yield and excellent Z-selectivity. Further insights into reactivity are obtained from the solid-state structures and soln. dynamics of the catalysts

    Structure and activity in cyclometallated Ru-based Z-selective metathesis catalysts

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    Previously, our group has reported a series of cyclometallated Ru- based Z- selective catalysts, where the N- aryl group was key to the selectivity obsd. Here, systematic variation of the N- aryl group provides insight into the steric and electronic contributions to both activity and selectivity in these catalysts. In addn., an unusual interaction is obsd. between certain substituents of the aryl ring and the alkylidene moiety and this interaction is studied both in soln. and the solid- state. The insights into structure and activity have allowed improved reactivity with a series of hindered olefin substrates

    Construction and Evaluation of a Subcutaneous Splenic Injection Port for Serial Intraportal Vein Cell Delivery in Murine Disease Models

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    The liver is the largest internal organ and the center of homeostatic metabolism. Liver-directed cell transplantation is, therefore, an attractive therapeutic option to treat various metabolic disorders as well as liver diseases. Although clinical liver-directed cell transplantation requires multiple cell injections into the portal venous system, a mouse model is lacking which allows us to perform repetitive cell injections into the portal venous system. Here, we propose a surgical model that utilizes the spleen as a subcutaneous injection port. Mouse spleens were translocated under the skin with intact vascular pedicles. Human placental stem cell transplantations were performed one week following this port construction and repeated three times. Cell distribution was analyzed by quantifying human DNA using human Alu-specific primers. About 50% of the transplanted cells were located homogeneously in the liver one hour after the splenic port injection. Fluorescent-labeled cell tracking and antihuman mitochondrion immunohistochemistry studies demonstrated that the cells localized predominantly in small distal portal branches. A similar cell distribution was observed after multiple cell injections. These data confirm that the subcutaneous splenic injection port is suitable for performing repetitive cell transplantation into the portal venous system of mouse models

    Single-nuclei multiomic analyses identify human cardiac lymphatic endothelial cells associated with coronary arteries in the epicardium

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    Summary: Cardiac lymphatic vessels play important roles in fluid homeostasis, inflammation, disease, and regeneration of the heart. The developing cardiac lymphatics in human fetal hearts are closely associated with coronary arteries, similar to those in zebrafish hearts. We identify a population of cardiac lymphatic endothelial cells (LECs) that reside in the epicardium. Single-nuclei multiomic analysis of the human fetal heart reveals the plasticity and heterogeneity of the cardiac endothelium. Furthermore, we find that VEGFC is highly expressed in arterial endothelial cells and epicardium-derived cells, providing a molecular basis for the arterial association of cardiac lymphatic development. Using a cell-type-specific integrative analysis, we identify a population of cardiac lymphatic endothelial cells marked by the PROX1 and the lymphangiocrine RELN and enriched in binding motifs of erythroblast transformation specific (ETS) variant (ETV) transcription factors. We report the in vivo molecular characterization of human cardiac lymphatics and provide a valuable resource to understand fetal heart development

    Malignancy during pregnancy in Japan: an exceptional opportunity for early diagnosis

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    Abstract Background Malignancy during pregnancy has become a significant cause of maternal death in developed countries, likely due to both an older pregnant population, and increases of cervical cancer in younger women. Our aim is to investigate the clinical aspects of malignancy during pregnancy in Japan and to use this information to identify opportunities for earlier detection and treatment. Methods We provided a questionnaire to 1508 secondary or tertiary care hospitals in Japan. We reviewed the clinical characteristics of cases with malignancy during pregnancy for the period of January to December, 2008. From the 760 institutions which responded, we obtained clinical information for 227 unique cases. The questionnaire provided clinical information, including disease site, pregnancy outcome and how the disease was detected. Results The most common type of malignancy was cervical cancer (n = 162, 71.4%) followed by ovarian (n = 16, 7.0%) and breast cancer (n = 15, 6.6%). Leukemia (n = 7, 3.1%), colon cancer (n = 5, 2.2%), gastric cancer (n = 5, 2.2%), malignant lymphoma (n = 4, 1.8%), thyroid cancer (n = 3, 1.3%), brain cancer (n = 3, 1.3%), endometrial cancer (n = 2, 0.9%), and head and neck cancer (n = 2, 0.9%) accounted for the remaining cases. Overall, gynecological malignancies accounted for 79.3% (95% confidence interval 74.0–84.6) of pregnancy associated malignancies diagnosed in the present study. The majority of cervical cancers, 149 (92.0%) of 162, were diagnosed by a Pap (Papanicolaou) smear during early gestation. Ten (62.5%) of the ovarian cancer cases were diagnosed by ultrasonography during a prenatal checkup or at the time of initial pregnancy diagnosis. Out of 14 breast cancers, only one (7.1%) was diagnosed by screening breast exam. Conclusions From this study, we reaffirm the clear and significant benefits of prenatal checkups starting at an early gestational age for the detection of gynecological cancers during pregnancy. Conversely, breast cancer detection during pregnancy was poor, suggesting new strategies for early identification of this disease are required

    Comprehensive Serum Glycopeptide Spectra Analysis (CSGSA): A Potential New Tool for Early Detection of Ovarian Cancer

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    Objectives: To conduct a comprehensive glycopeptide spectra analysis of serum between cancer and non-cancer patients to identify early biomarkers of epithelial ovarian cancer (EOC). Methods: Approximately 30,000 glycopeptide peaks were detected from the digested serum glycoproteins of 39 EOC patients (23 early-stage, 16 advanced-stage) and 45 non-cancer patients (27 leiomyoma and ovarian cyst cases, 18 endometrioma cases) by liquid chromatography mass spectrometry (LC−MS). The differential glycopeptide peak spectra were analyzed to distinguish between cancer and non-cancer groups by employing multivariate analysis including principal component analysis (PCA), orthogonal partial least squares discriminant analysis (OPLS-DA) and heat maps. Results: Examined spectral peaks were filtered down to 2281 serum quantitative glycopeptide signatures for differentiation between ovarian cancer and controls using multivariate analysis. The OPLS-DA model using cross-validation parameters R2 and Q2 and score plots of the serum samples significantly differentiated the EOC group from the non-cancer control group. In addition, women with early-stage clear cell carcinoma and endometriomas were clearly distinguished from each other by OPLS-DA as well as by PCA and heat maps. Conclusions: Our study demonstrates the potential of comprehensive serum glycoprotein analysis as a useful tool for ovarian cancer detection
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