27 research outputs found

    The cardiac veins and retrograde coronary venous perfusion

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    Study of retrograde coronary venous perfusion has been greatly overshadowed in the past decade by the advent and success of direct coronary artery revascularization. Recently there has been renewed interest in retrograde venous perfusion as a possible means of restoring myocardial circulation in selected patients. This paper reviews the anatomy and physiology of the cardiac venous system and the history of retrograde venous perfusion, with emphasis on recent experimental work and clinical trials involving retrograde coronary vein perfusion (RCVP)

    Superiority of bilateral internal thoracic artery grafting in long-term survival after coronary artery bypass through the lenses of a bedside risk score

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    Objective: Risk algorithms for the prediction of long-term survival after coronary artery bypass grafting (CABG) do not include the use of bilateral internal thoracic artery (BITA) grafting among the independent predictors. We sought to reveal the superiority of BITA grafting in the long-term outcome through the lenses of an existing bedside risk score (BRS). Methods: This study analyzed data from 5,666 consecutive patients undergoing isolated (n = 4,715 – BITA = 2,792) and combined (n = 951 – BITA = 246) CABG. The mean follow-up period was 10.3 years (interquartile range, 9.9 years). All the predictors of an existing BRS were available for analysis (age, body mass index, ejection fraction, unstable hemodynamic state, left main disease, cerebrovascular disease, peripheral arterial disease, congestive heart failure, malignant ventricular arrhythmia, chronic obstructive pulmonary disease, diabetes, and previous heart surgery). Furthermore, a modified BRS was constructed taking into account the use of BITA grafting and combined CABG. Results: The good discriminatory ability and satisfactory calibration of the BRS was confirmed in the isolated CABG subgroup. The modified BRS showed improved discriminatory ability and similar calibration. It showed a time-varying coefficient, and accordingly, we calculated the adjusted survival predictions up to 20 years after isolated and combined CABG with or without BITA grafting. Patients with BITA grafting in the low-risk quartile showed 68.4% and 65.5% predicted survival rates at 20 years in the isolated and combined CABG subgroups, respectively, versus the survival rates of 56.4% and 52.8% observed among patients without BITA grafting. Conclusion: The modified BRS is a useful simplified algorithm for clinicians in choosing treatment intervention for severe isolated or combined coronary artery disease. We clearly demonstrated the superiority of BITA grafting in long-term survival throughout the entire range of the modified BRS. © 2021 Hellenic Society of Cardiolog

    The Ross-Konno procedure as reoperative treatment in a young adult with congenital aortic stenosis

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    Mechanical and biological prostheses are valid options when aortic valve replacement is necessary. The Ross procedure is also an alternative solution, especially for young patients. We describe the case of a young patient with congenital aortic stenosis and bicuspid aortic valve who presented with dyspnea on exertion. An open commissurotomy was performed, and within 8 months the patient developed recurrent symptoms of severe aortic stenosis. He underwent redo sternotomy and a Ross-Konno procedure with an uneventful recovery. © 2012 Forum Multimedia Publishing, LLC

    Pediatric ependymoma: A proteomics perspective

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    Background/Aim: Proteomics based on highresolution mass spectrometry (MS) is the tool of choice for the analysis of protein presence, modifications and interactions, with increasing emphasis on the examination of tumor tissues. Application of MS-based proteomics offers a detailed picture of tumor tissue characteristics, facilitating the appreciation of different tumor entities, whilst providing reliable and fast results for therapeutic marker targeting and prognostic factor assessment. Through use of the high analytical resolution of nano-high-pressure liquid chromatography (nanoHPLC) and the high resolution of an Orbitrap Elite mass spectrometer, the present study aimed to provide knowledge on the proteome of the generally unknown entity of pediatric ependymal tumors. Materials and Methods: Ten resected specimens of childhood ependymoma were analyzed through a one-dimensional (1D) nanoLC-MS/MS approach. Method optimization steps were undertaken for both the sample preparation/protein extraction procedure and LC parameters, aiming to achieve the highest possible identification rates. Results: Following method optimization, each nanoLC-MS/MS run resulted in identification of more than 5,000 proteins and more than 25,000 peptides for every analyzed sample, thus detailing the greater part of the ependymoma proteome. Identified proteins were found to spread throughout all known tumor categories regarding their molecular function and subcellular localization. Conclusion: Through the proposed nanoLC-MS/MS method herein we report, for the firs time, the ependymoma proteome database. A large number of similarities regarding proteome content are revealed compared to other two pediatric brain tumor entities; astrocytomas and medulloblastomas. Furthermore, through our approach, the majority of currently proposed markers for ependymoma (e.g. nucleolin, nestin, Ki67 and laminin subunit A2) as well as all major key players of the phosphoinositide 3-kinase pathway (seemingly implicated in ependymoma), were definitely detected

    Molecular proteomic characterization of a pediatric medulloblastoma xenograft

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    Background/Aim: Medulloblastoma (MBL), an archetypal primitive neuroectodermal tumor of the cerebellum, is the most common pediatric central nervous system malignancy representing approximately 20% of all childhood brain tumors. Herein, we report on a new xenotransplantable tumor cell line, derived from a 6-yearold female patient with cerebellar medulloblastoma, and the completele proteome molecular characterization of subsequent tumors from MBL xenotrasplanted mice. Materials and Methods: Tumors were grown in nude mice as subcutaneous xenografts (MBLX) composed of small round cells with hyperchromatic nuclei and scant cytoplasm. Tumor specimen were extracted from animals upon their sacrifice and their molecular proteomic content was analyzed by 2-DE coupled to MALDI-TOF MS analysis. Results: Altogether 350 single-gene products were identified through the current approach, reported as the MBLX database. Conclusion: This new xenotransplantable tumor model, offers the scientific community valuable insight on the validity of xenografts altogether, while providing the means for a novel experimental model towards the study of human MBL

    Molecular proteomic characterization of a pediatric medulloblastoma xenograft

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    Background/Aim: Medulloblastoma (MBL), an archetypal primitive neuroectodermal tumor of the cerebellum, is the most common pediatric central nervous system malignancy representing approximately 20% of all childhood brain tumors. Herein, we report on a new xenotransplantable tumor cell line, derived from a 6-yearold female patient with cerebellar medulloblastoma, and the completele proteome molecular characterization of subsequent tumors from MBL xenotrasplanted mice. Materials and Methods: Tumors were grown in nude mice as subcutaneous xenografts (MBLX) composed of small round cells with hyperchromatic nuclei and scant cytoplasm. Tumor specimen were extracted from animals upon their sacrifice and their molecular proteomic content was analyzed by 2-DE coupled to MALDI-TOF MS analysis. Results: Altogether 350 single-gene products were identified through the current approach, reported as the MBLX database. Conclusion: This new xenotransplantable tumor model, offers the scientific community valuable insight on the validity of xenografts altogether, while providing the means for a novel experimental model towards the study of human MBL

    Anandamide metabolism by Tetrahymena pyriformis in vitro. Characterization and identification of a 66 kDa fatty acid amidohydrolase

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    Fatty acid amidohydrolase, a membrane-bound enzyme found in a variety of mammalian cells, is responsible for the catabolism of neuromodulatory fatty acid amides, including anandamide. In an earlier study we reported that Tetrahymena pyriformis was able to secrete a FAAH-like activity in starvation medium (Karava V., Fasia L., Siafaka-Kapadai A., FEBS Lett. 508 (2001) 327-331). In this study the endocannabinoid anandamide, was found to be metabolized by T. pyriformis homogenate by the action of a FAAH-like enzyme, in a time- and concentration-dependent manner. The main metabolic products of [ 3H]anandamide hydrolysis were [3H]arachidonic acid and ethanolamine. Amidohydrolase activity was maximal at pH 9-10, it was inhibited by phenylmethylsulfonyl fluoride and arachidonyltrifluoromethyl ketone and was Ca2+ and Mg2+-independent. Kinetic experiments demonstrated that the enzyme had an apparent Km of 2.5 μM and Vmax of 20.6:nmol/min mg. Subcellular fractionation of T. pyriformis homogenate showed that the activity was present in every subcellular fraction with highest specific activity in the microsomal as well as in non-microsomal membrane fraction. Immunoblot analysis of selected subcellular fractions, using an anti-FAAH polyclonal antibody, revealed the presence of an immunoreactive protein with a molecular mass ~66:kDa similar to the molecular mass of the mammalian enzyme. In conclusion, this study demonstrates that a FAAH similar to the mammalian enzyme is present in a unicellular eukaryote, indicating the importance of FAAH activity throughout evolution. It also supports the notion that Tetrahymena species may be a suitable model for metabolic studies on endocannabinoids, as well as for the study of drugs targeted towards FAAH

    Aprikalim a potassium adenosine triphosphate channel opener reduces neurologic injury in a rabbit model of spinal cord ischemia

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    Background: Potassium adenosine triphosphate (KATP) channel openers have been involved in the enhancement of ischemic tolerance in various tissues. The purpose of the present study is to evaluate the effects of aprikalim, a specific KATP channel opener, on spinal cord ischemic injury. Methods: Fifty-four rabbits were randomly assigned to three groups: group 1 (n = 18, sham operation), group 2 (n = 18, 30 min of normothermic aortic cross-clamping) and group 3 (n = 18, aprikalim 100 μg/kg was administered 15 min before 30 min of normothermic aortic cross-clamping). Neurologic evaluation was performed according to the modified Tarlov scale. Six animals from each group were sacrificed at 24, 48 and 168 h postoperatively. The lumbar spinal cords were harvested and examined histologically. The motor neurons were counted and the histologic lesions were scored (0-3, 3: normal). Results: Group 3 (aprikalim group) had better Tarlov scores compared to group 2 at all-time points (P < 0.025). The histologic changes were proportional to the Tarlov scores and group 3 had better functional outcome as compared to group 2 at 168 h (number of neurons: 21.2 ± 4.9 vs. 8.0 ± 2.7, P < 0.001 and histologic score: 1.67 ± 1.03 vs. 0.50 ± 0.55, P = 0.03). Although aprikalim exhibited improved effect on clinical and histologic neurologic outcome when compared to normothermic spinal cord ischemia, animals in group 3 had worse Tarlov score, reduced number of motor neurons and worse histologic score when compared to group 1 (sham operation) at 168 h (P = 0.003, P = 0.001 and P = 0.019 respectively). Conclusion: Aprikalim reduces the severity of spinal cord ischemic injury in a rabbit model of spinal cord ischemia. © 2013 Surgical Associates Ltd
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