Browsing by Author "Ramirez, Pablo"

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    Balloon pulmonary angioplasty for the treatment of chronic thromboembolic pulmonary hypertension
    (SOC MEDICA SANTIAGO, 2019) Sepulveda, Pablo; Ortega, Juan; Armijo, German; Torres, Jose; Ramirez, Pablo; Backhouse, Christian; Vargas, Cesar; Lopez, Leonel; Gonzalez, Felipe; Puentes, Angel; Donoso, Hernan; Bellet, Augusto; Godoy, Diego; Araya, Mario; Luz Andrade, Carmen; Pablo Molina, Juan; Nazzal, Carolina
    Background: Balloon pulmonary angioplasty (BPA) is a therapeutic alternative for patients with inoperable chronic thromboembolic pulmonary hypertension (CTEPH). Aim: To report the initial experience with the "refined BPA technique" with the use of intravascular images. Patients and Methods: Between June 2015 and June 2016 we selected fourteen patients with CTEPH who were considered candidates for BPA. Lesions targeted for treatment were further analyzed using intravascular imaging with optical frequency domain imaging (OFDI). We report the immediate hemodynamic results and four weeks of follow-up of the first eight patients of this series. Results: We performed 16 BPA in eight patients aged 61 +/- 14 years (88% women). Mean pulmonary artery pressure (PAPm) was 48.6 +/- 5.8 mmHg. Success was achieved in seven patients (88%). A mean of 2.3 segments per patient were intervened in 11 sessions (1.6 sessions/patient). Only one patient developed lung reperfusion injury. No mortality was associated with the procedure. After the last BPA session, PAPm decreased to 37.4 +/- 8.6 mmHg (p=0.02). Pulmonary vascular resistance (RVP) decreased from 858,6 +/- 377,0 at baseline to 516,6 +/- 323,3 Dynes/sec/cm(-5) (p<0.01) and the cardiac index increased from 2.4 +/- 0.6 at baseline to 2.8 +/- 0.3 L/min/m(2) (p=0.01). At 4 weeks after the last BPA, WHO functional class improved from 3.3 +/- 0.5 to 2.5 +/- 0.5 (p<0,01) and six minutes walking distance from 331 +/- 92 to 451 +/- 149 m (p=0.01). Conclusions: BPA guided by OFDI for the treatment of inoperable CTEPH patients is a safe alternative with excellent immediate hemodynamic and clinical results.
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    Bone Marrow Stromal Cells Modulate Mouse ENT1 Activity and Protect Leukemia Cells from Cytarabine Induced Apoptosis
    (PUBLIC LIBRARY SCIENCE, 2012) Macanas Pirard, Patricia; Leisewitz, Andrea; Broekhuizen, Richard; Cautivo, Kelly; Barriga, Francisco M.; Leisewitz, Francisco; Gidi, Victoria; Riquelme, Erick; Montecinos, Viviana P.; Swett, Pilar; Besa, Pelayo; Ramirez, Pablo; Ocqueteau, Mauricio; Kalergis, Alexis M.; Holt, Matthew; Rettig, Michael; DiPersio, John F.; Nervi, Bruno
    Background: Despite a high response rate to chemotherapy, the majority of patients with acute myeloid leukemia (AML) are destined to relapse due to residual disease in the bone marrow (BM). The tumor microenvironment is increasingly being recognized as a critical factor in mediating cancer cell survival and drug resistance. In this study, we propose to identify mechanisms involved in the chemoprotection conferred by the BM stroma to leukemia cells.
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    Hematopoietic stem cell transplantation: clinical use and perspectives
    (SOC BIOLGIA CHILE, 2012) Barriga, Francisco; Ramirez, Pablo; Wietstruck, Angelica; Rojas, Nicolas
    Hematopoietic stem cell transplantation is the accepted therapy of choice for a variety of malignant and non-malignant diseases in children and adults. Initially developed as rescue therapy for a patient with cancer after high doses of chemotherapy and radiation as well as the correction of severe deficiencies in the hematopoietic system, it has evolved into an adoptive immune therapy for malignancies and autoimmune disorders. The procedure has helped to obtain key information about the bone marrow environment, the biology of hematopoietic stem cells and histocompatibility. The development of this new discipline has allowed numerous groups working around the world to cure patients of diseases previously considered lethal. Together with the ever growing list of volunteer donors and umbilical cord blood banks, this has resulted in life saving therapy for thousands of patients yearly. We present an overview of the procedure from its cradle to the most novel applications, as well as the results of the HSC transplant program developed at our institution since 1989.
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    MID-TERM FOLLOW UP OF BALLOON PULMONARY ANGIOPLASTY FOR INOPERABLE CHRONIC THROMBOEMBOLIC PULMONARY HYPERTENSION: INITIAL MULTICENTER EXPERIENCE IN CHILE
    (ELSEVIER SCIENCE INC, 2020) Andres Sepulveda, Pablo; Hameau, Rene; Backhouse, Christian; Charme, Gustavo; Ramirez, Pablo; Pacheco, Francisco; Fuensalida, Alberto; Quitral, Jorge; Martinez Sepulveda, Alejandro; Martinez, Gonzalo
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    Prophylaxis against cytomegalovirus infection in pediatric and adult patients undergoing solid organ and hematopoietic stem cells transplantation
    (SOC CHILENA INFECTOLOGIA, 2012) Ferres, Marcela; Nervi, Bruno; Ramirez, Pablo
    CMV is one of the main infectious problems for SOT and HSCT. The severity of the complications are mainly associated with the type of transplant and immune status against the virus of the transplant donor and the transplant recipient. It is important to prevent exposure, using safe blood transfusion CMV seronegative donors (B1) and/or use of blood leucocytes-depleted by filtration (A1). In addition to preventing exposure, there are two widely used prevention strategies: universal prophylaxis with antiviral therapy or "pre-emptive" strategy based on the use of antivirals only to the early detection of CMV replication in blood. The first option is most used in the SOT management, especially for those identified as the high risk group of CMV disease: R (+), with D (+) or D (-) (A1), where the recommended drug is ganciclovir or valganciclovir. The second approach is preferable for HSCT, which recommends weekly monitoring for CMV viral load from day 10 to 100 post transplant (A3). This strategy requires having a viral laboratory support (A2). The selected antiviral in the case of pre emptive therapy is intravenous ganciclovir (A1).