140 results on '"Juan C Ramirez"'
Search Results
2. Serological based monitoring of a cohort of patients with chronic Chagas disease treated with benznidazole in a highly endemic area of northern Argentina
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Leticia L Niborski, Vanina Grippo, Sonia O Lafón, Gabriela Levitus, Facundo García-Bournissen, Juan C Ramirez, Juan M Burgos, Margarita Bisio, Natalia A Juiz, Vilma Ayala, María Coppede, Verónica Herrera, Crescencia López, Ana Contreras, Karina A Gómez, Juan C Elean, Hugo D Mujica, Alejandro G Schijman, Mariano J Levin, and Silvia A Longhi
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Trypanosoma cruzi ,chronic Chagas disease ,benznidazole treatment ,serological follow-up ,adverse effects ,Microbiology ,QR1-502 ,Infectious and parasitic diseases ,RC109-216 - Abstract
This study aimed to evaluate well-documented diagnostic antigens, named B13, 1F8 and JL7 recombinant proteins, as potential markers of seroconversion in treated chagasic patients. Prospective study, involving 203 patients treated with benznidazole, was conducted from endemic areas of northern Argentina. Follow-up was possible in 107 out of them and blood samples were taken for serology and PCR assays before and 2, 3, 6, 12, 24 and 36 months after treatment initiation. Reactivity against Trypanosoma cruzi lysate and recombinant antigens was measured by ELISA. The rate of decrease of antibody titers showed nonlinear kinetics with an abrupt drop within the first three months after initiation of treatment for all studied antigens, followed by a plateau displaying a low decay until the end of follow-up. At this point, anti-B13, anti-1F8 and anti-JL7 titers were relatively close to the cut-off line, while anti-T. cruzi antibodies still remained positive. At baseline, 60.8% (45/74) of analysed patients tested positive for parasite DNA by PCR and during the follow-up period in 34 out of 45 positive samples (75.5%) could not be detected T. cruzi DNA. Our results suggest that these antigens might be useful as early markers for monitoring antiparasitic treatment in chronic Chagas disease.
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- 2016
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3. Analytical performance of a multiplex Real-Time PCR assay using TaqMan probes for quantification of Trypanosoma cruzi satellite DNA in blood samples.
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Tomas Duffy, Carolina I Cura, Juan C Ramirez, Teresa Abate, Nelly M Cayo, Rudy Parrado, Zoraida Diaz Bello, Elsa Velazquez, Arturo Muñoz-Calderon, Natalia A Juiz, Joaquín Basile, Lineth Garcia, Adelina Riarte, Julio R Nasser, Susana B Ocampo, Zaida E Yadon, Faustino Torrico, Belkisyole Alarcón de Noya, Isabela Ribeiro, and Alejandro G Schijman
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Arctic medicine. Tropical medicine ,RC955-962 ,Public aspects of medicine ,RA1-1270 - Abstract
BACKGROUND: The analytical validation of sensitive, accurate and standardized Real-Time PCR methods for Trypanosoma cruzi quantification is crucial to provide a reliable laboratory tool for diagnosis of recent infections as well as for monitoring treatment efficacy. METHODS/PRINCIPAL FINDINGS: We have standardized and validated a multiplex Real-Time quantitative PCR assay (qPCR) based on TaqMan technology, aiming to quantify T. cruzi satellite DNA as well as an internal amplification control (IAC) in a single-tube reaction. IAC amplification allows rule out false negative PCR results due to inhibitory substances or loss of DNA during sample processing. The assay has a limit of detection (LOD) of 0.70 parasite equivalents/mL and a limit of quantification (LOQ) of 1.53 parasite equivalents/mL starting from non-boiled Guanidine EDTA blood spiked with T. cruzi CL-Brener stock. The method was evaluated with blood samples collected from Chagas disease patients experiencing different clinical stages and epidemiological scenarios: 1- Sixteen Venezuelan patients from an outbreak of oral transmission, 2- Sixty three Bolivian patients suffering chronic Chagas disease, 3- Thirty four Argentinean cases with chronic Chagas disease, 4- Twenty seven newborns to seropositive mothers, 5- A seronegative receptor who got infected after transplantation with a cadaveric kidney explanted from an infected subject. CONCLUSIONS/SIGNIFICANCE: The performing parameters of this assay encourage its application to early assessment of T. cruzi infection in cases in which serological methods are not informative, such as recent infections by oral contamination or congenital transmission or after transplantation with organs from seropositive donors, as well as for monitoring Chagas disease patients under etiological treatment.
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- 2013
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4. Non-integrative lentivirus drives high-frequency cre-mediated cassette exchange in human cells.
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Raul Torres, Aida García, Monica Payá, and Juan C Ramirez
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Medicine ,Science - Abstract
Recombinase mediated cassette exchange (RMCE) is a two-step process leading to genetic modification in a specific genomic target sequence. The process involves insertion of a docking genetic cassette in the genome followed by DNA transfer of a second cassette flanked by compatible recombination signals and expression of the recombinase. Major technical drawbacks are cell viability upon transfection, toxicity of the enzyme, and the ability to target efficiently cell types of different origins. To overcome such drawbacks, we developed an RMCE assay that uses an integrase-deficient lentivirus (IDLV) vector in the second step combined with promoterless trapping of double selectable markers. Additionally, recombinase expression is self-limiting as a result of the exchangeable reaction, thus avoiding toxicity. Our approach provides proof-of-principle of a simple and novel strategy with expected wide applicability modelled on a human cell line with randomly integrated copies of a genetic landing pad. This strategy does not present foreseeable limitations for application to other cell systems modified by homologous recombination. Safety, efficiency, and simplicity are the major advantages of our system, which can be applied in low-to-medium throughput strategies for screening of cDNAs, non-coding RNAs during functional genomic studies, and drug screening.
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- 2011
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5. A chemokine targets the nucleus: Cxcl12-gamma isoform localizes to the nucleolus in adult mouse heart.
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Raul Torres and Juan C Ramirez
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Medicine ,Science - Abstract
Chemokines are extracellular mediators of complex regulatory circuits involved principally in cell-to-cell communication. Most studies to date of the essential chemokine Cxcl12 (Sdf-1) have focused on the ubiquitously expressed secreted isoforms alpha and beta. Here we show that, unlike these isoforms and all other known chemokines, the alternatively transcribed gamma isoform is an intracellular protein that localizes to the nucleolus in differentiated mouse Cardiac tissue. Our results demonstrate that nucleolar transportation is encoded by a nucleolar-localization signal in the unique carboxy-terminal region of Sdf-1gamma, and is competent both in vivo and in vitro. The molecular mechanism underlying these unusual chemokine properties involves cardiac-specific transcription of an mRNA containing a unique short-leader sequence lacking the signal peptide and translation from a non-canonical CUG codon. Our results provide an example of genome economy even for essential and highly conserved genes such as Cxcl12, and suggest that chemokines can exert tissue specific functions unrelated to cell-to-cell communication.
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- 2009
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6. Sex differences in machine learning computed tomography-derived fractional flow reserve
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Mahmoud Al Rifai, Ahmed Ibrahim Ahmed, Yushui Han, Jean Michel Saad, Talal Alnabelsi, Faisal Nabi, Su Min Chang, Myra Cocker, Chris Schwemmer, Juan C. Ramirez-Giraldo, William A. Zoghbi, John J. Mahmarian, and Mouaz H. Al-Mallah
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Medicine ,Science - Abstract
Abstract Coronary computed tomography angiography (CCTA) derived machine learning fractional flow reserve (ML-FFRCT) can assess the hemodynamic significance of coronary artery stenoses. We aimed to assess sex differences in the association of ML-FFRCT and incident cardiovascular outcomes. We studied a retrospective cohort of consecutive patients who underwent clinically indicated CCTA and single photon emission computed tomography (SPECT). Obstructive stenosis was defined as ≥ 70% stenosis severity in non-left main vessels or ≥ 50% in the left main coronary. ML-FFRCT was computed using a machine learning algorithm with significant stenosis defined as ML-FFRCT
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- 2022
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7. Preclinical studies of efficacy thresholds and tolerability of a clinically ready lentiviral vector for pyruvate kinase deficiency treatment
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Susana Navarro, Oscar Quintana-Bustamante, Rebeca Sanchez-Dominguez, Sergio Lopez-Manzaneda, Isabel Ojeda-Perez, Aida Garcia-Torralba, Omaira Alberquilla, Kenneth Law, Brian C. Beard, Antonella Bastone, Michael Rothe, Mariela Villanueva, Juan C. Ramirez, Sara Fañanas-Baquero, Virginia Nieto-Romero, Andrea Molinos-Vicente, Sonia Gutierrez, Eileen Nicoletti, María García-Bravo, Juan A. Bueren, Jonathan D. Schwartz, and Jose-Carlos Segovia
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hematopoiesis ,gene therapy ,lentiviral vectors ,erythroid metabolic diseases ,pyruvate kinase deficiency ,biodistribution ,Genetics ,QH426-470 ,Cytology ,QH573-671 - Abstract
Pyruvate kinase deficiency (PKD) is a rare autosomal recessive disorder caused by mutations in the PKLR gene. PKD is characterized by non-spherocytic hemolytic anemia of variable severity and may be fatal in some cases during early childhood. Although not considered the standard of care, allogeneic stem cell transplantation has been shown as a potentially curative treatment, limited by donor availability, toxicity, and incomplete engraftment. Preclinical studies were conducted to define conditions to enable consistent therapeutic reversal, which were based on our previous data on lentiviral gene therapy for PKD. Improvement of erythroid parameters was identified by the presence of 20%–30% healthy donor cells. A minimum vector copy number (VCN) of 0.2−0.3 was required to correct PKD when corrected cells were transplanted in a mouse model for PKD. Biodistribution and pharmacokinetics studies, with the aim of conducting a global gene therapy clinical trial for PKD patients (RP-L301-0119), demonstrated that genetically corrected cells do not confer additional side effects. Moreover, a clinically compatible transduction protocol with mobilized peripheral blood CD34+ cells was optimized, thus facilitating the efficient transduction on human cells capable of repopulating the hematopoiesis of immunodeficient mice. We established conditions for a curative lentiviral vector gene therapy protocol for PKD.
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- 2021
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8. Sorafenib as a second-line treatment in metastatic renal cell carcinoma in Mexico: a prospective cohort study
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Ana Elena Martín-Aguilar, Haidé Núñez-López, and Juan C. Ramirez-Sandoval
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Kidney cancer ,Tyrosine kinase inhibitor ,Sunitinib ,Sorafenib ,Clear cell carcinoma ,Cohort ,Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 - Abstract
Abstract Background Sequential inhibition of the vascular endothelial growth factor (VEGF) pathway with sorafenib could be useful for patients with metastatic renal cell carcinoma (RCC). Our aim was to determine the activity and tolerability of sorafenib as a second-line therapy in advanced RCC initially treated with a different VEGF-tyrosine kinase inhibitor (TKI). Methods A prospective observational cohort in Mexico (2012–2019). We included 132 subjects with metastatic RCC and who had progression despite treatment with sunitinib. The primary end-point was time to disease progression as evaluated every 12–16 weeks. Results The mean age of the cohort was 59 years (interquartile range [IQR] 50–72), 96 (73%) were men, and 48 (36%) had a favorable prognosis according to the IMDC (International Metastatic RCC Database Consortium) prognostic model. The median progression-free survival (PFS) and overall-survival after the introduction of sorafenib treatment was 8.6 months (95% confidence interval [CI]: 6.7–10.5) and 40 months (95% CI: 34.5–45.4) respectively. The median overall survival from RCC diagnosis to death was 71 months (95% CI: 58.2–83.8). On multivariable analyses, age > 65 years was associated with a longer PFS (HR 0.51; 95% CI: 0.31–0.86; p = 0.018). The median PFS in subjects aged > 65 years was longer compared to subjects ≤65 years (14.0 [95% CI: 9.2–18.8] vs. 7.2 months [95% CI: 5.3–9.1]; p = 0.012). Adverse events grade ≥ 3 associated with sorafenib occurred in 38 (29%) patients. Conclusion Sequential inhibition of VEGF with sorafenib as a second-line treatment may benefit patients with metastatic RCC, especially in subjects > 65 years old.
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- 2021
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9. Recurrent horizontal transfer identifies mitochondrial positive selection in a transmissible cancer
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Andrea Strakova, Thomas J. Nicholls, Adrian Baez-Ortega, Máire Ní Leathlobhair, Alexander T. Sampson, Katherine Hughes, Isobelle A. G. Bolton, Kevin Gori, Jinhong Wang, Ilona Airikkala-Otter, Janice L. Allen, Karen M. Allum, Clara L. Arnold, Leontine Bansse-Issa, Thinlay N. Bhutia, Jocelyn L. Bisson, Kelli Blank, Cristóbal Briceño, Artemio Castillo Domracheva, Anne M. Corrigan, Hugh R. Cran, Jane T. Crawford, Stephen M. Cutter, Eric Davis, Karina F. de Castro, Andrigo B. De Nardi, Anna P. de Vos, Laura Delgadillo Keenan, Edward M. Donelan, Adela R. Espinoza Huerta, Ibikunle A. Faramade, Mohammed Fazil, Eleni Fotopoulou, Skye N. Fruean, Fanny Gallardo-Arrieta, Olga Glebova, Pagona G. Gouletsou, Rodrigo F. Häfelin Manrique, Joaquim J. G. P. Henriques, Rodrigo S. Horta, Natalia Ignatenko, Yaghouba Kane, Cathy King, Debbie Koenig, Ada Krupa, Steven J. Kruzeniski, Marta Lanza-Perea, Mihran Lazyan, Adriana M. Lopez Quintana, Thibault Losfelt, Gabriele Marino, Simón Martínez Castañeda, Mayra F. Martínez-López, Bedan M. Masuruli, Michael Meyer, Edward J. Migneco, Berna Nakanwagi, Karter B. Neal, Winifred Neunzig, Sally J. Nixon, Antonio Ortega-Pacheco, Francisco Pedraza-Ordoñez, Maria C. Peleteiro, Katherine Polak, Ruth J. Pye, Juan C. Ramirez-Ante, John F. Reece, Jose Rojas Gutierrez, Haleema Sadia, Sheila K. Schmeling, Olga Shamanova, Alan G. Sherlock, Audrey E. Steenland-Smit, Alla Svitich, Lester J. Tapia Martínez, Ismail Thoya Ngoka, Cristian G. Torres, Elizabeth M. Tudor, Mirjam G. van der Wel, Bogdan A. Vițălaru, Sevil A. Vural, Oliver Walkinton, Alvaro S. Wehrle-Martinez, Sophie A. E. Widdowson, Irina Zvarich, Patrick F. Chinnery, Maria Falkenberg, Claes M. Gustafsson, and Elizabeth P. Murchison
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Science - Abstract
The competitive dynamics of mitochondrial haplotypes juxtaposed within the same cell are poorly studied. Here the authors show, in the context of a transmissible cancer, that one haplotype has recurrently entered cancer cells by horizontal transfer and appears to have a ‘selfish’ selective advantage.
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- 2020
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10. Development and evaluation of a duplex TaqMan qPCR assay for detection and quantification of Trypanosoma cruzi infection in domestic and sylvatic reservoir hosts
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Diana P. Wehrendt, Andrea Gómez-Bravo, Juan C. Ramirez, Carolina Cura, Angélica Pech-May, Janine M. Ramsey, Marcelo Abril, Felipe Guhl, and Alejandro G. Schijman
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Trypanosoma cruzi ,Chagas disease ,Mammalian reservoirs ,Molecular epidemiology ,Internal amplification standard ,Multiplex qPCR ,Infectious and parasitic diseases ,RC109-216 - Abstract
Abstract Background A question of epidemiological relevance in Chagas disease studies is to understand Trypanosoma cruzi transmission cycles and trace the origins of (re)emerging cases in areas under vector or disease surveillance. Conventional parasitological methods lack sensitivity whereas molecular approaches can fill in this gap, provided that an adequate sample can be collected and processed and a nucleic acid amplification method can be developed and standardized. We developed a duplex qPCR assay for accurate detection and quantification of T. cruzi satellite DNA (satDNA) sequence in samples from domestic and sylvatic mammalian reservoirs. The method incorporates amplification of the gene encoding for the interphotoreceptor retinoid-binding protein (IRBP), highly conserved among mammalian species, as endogenous internal amplification control (eIAC), allowing distinction of false negative PCR findings due to inadequate sample conditions, DNA degradation and/or PCR interfering substances. Results The novel TaqMan probe and corresponding primers employed in this study improved the analytical sensitivity of the assay to 0.01 par.eq/ml, greater than that attained by previous assays for Tc I and Tc IV strains. The assay was tested in 152 specimens, 35 from 15 different wild reservoir species and 117 from 7 domestic reservoir species, captured in endemic regions of Argentina, Colombia and Mexico and thus potentially infected with different parasite discrete typing units. The eIACs amplified in all samples from domestic reservoirs from Argentina and Mexico, such as Canis familiaris, Felis catus, Sus scrofa, Ovis aries, Equus caballus, Bos taurus and Capra hircus with quantification cycles (Cq’s) between 23 and 25. Additionally, the eIACs amplified from samples obtained from wild mammals, such as small rodents Akodon toba, Galea leucoblephara, Rattus rattus, the opossums Didelphis virginiana, D. marsupialis and Marmosa murina, the bats Tadarida brasiliensis, Promops nasutus and Desmodus rotundus, as well as in Conepatus chinga, Lagostomus maximus, Leopardus geoffroyi, Lepus europaeus, Mazama gouazoubira and Lycalopex gymnocercus, rendering Cq’s between 24 and 33. Conclusions This duplex qPCR assay provides an accurate laboratory tool for screening and quantification of T. cruzi infection in a vast repertoire of domestic and wild mammalian reservoir species, contributing to improve molecular epidemiology studies of T. cruzi transmission cycles.
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- 2019
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11. Effect of Kidney transplantation on cyst growth in autosomal dominant polycystic kidney disease
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Jorge E. Gaytan-Arocha, Aaron Pérez-Segovia, Estefania Reul-Linares, Elisa Naomi Hernández-Paredes, Mónica Chapa-Ibargüengoitia, Ricardo Correa-Rotter, Luis E. Morales-Buenrostro, and Juan C. Ramirez-Sandoval
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Nephrology ,General Medicine - Published
- 2023
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12. Optimizing peritoneal dialysis initiation: A comparative cohort study of catheter placement methods for shortening break‐in periods
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Hugo E. Chávez‐Chávez, Elisa Naomi Hernández‐Paredes, Gabriel Cojuc‐Konigsberg, Cecilia Vargas‐Rodríguez, Laura Margarita Díaz‐Canchola, Octavio Vergara‐Zavala, Alonso Fernández‐Venegas, Nadia Stephani Acevedo‐Juárez, Ricardo Correa‐Rotter, and Juan C. Ramirez‐Sandoval
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Nephrology ,Hematology - Published
- 2023
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13. Validation of an equation for free calcium estimation: accuracy improves after adjustment for phosphate and CO2
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Juan C. Ramirez-Sandoval, Pablo Diener-Cabieses, Fabián Gutiérrez-Valle, Sofía Ley-Tapia, Santiago Pastrana-Brandes, Pablo E. Galindo, Reynerio Fagundo, Mauricio Moreno-Yañez, Alfredo Adolfo Reza-Albarrán, and Ricardo Correa-Rotter
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Nephrology ,Urology - Published
- 2022
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14. Comparison of Radiation Dose and Image Quality of Pediatric High-Resolution Chest CT Between Photon-Counting Detector CT and Energy-Integrated Detector CT: A Matched Study
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Marilyn J. Siegel, Scott M. Bugenhagen, Adrian Sanchez, Stacy Kim, Andres Abadia, and Juan C. Ramirez-Giraldo
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Radiology, Nuclear Medicine and imaging ,General Medicine - Published
- 2023
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15. 'La Perla Del Mar': A Case Report on Subcutaneous Penile Implants
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Juan C Ramirez, Praveen D Wickremasinghe, Luis X Mayol-Velez, and Guillermo Izquierdo-Pretel
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General Engineering - Published
- 2023
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16. Community- and Hospital-Acquired Acute Kidney Injury in COVID-19: Different Phenotypes and Dismal Prognosis
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Olynka Vega-Vega, Nathan Berman-Parks, Jorge E. Gaytan-Arocha, Ricardo Correa-Rotter, R Angélica Méndez-Pérez, Juan C. Ramirez-Sandoval, Mauricio Arvizu-Hernandez, Roque A Comunidad-Bonilla, Juan M. Mejia-Vilet, Dheni A. Fernández-Camargo, Rigoberto D. Álvarez, Areli Flores-Camargo, and Armando J. Martínez-Rueda
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Adult ,Male ,medicine.medical_specialty ,medicine.medical_treatment ,urologic and male genital diseases ,Risk Factors ,Internal medicine ,medicine ,Humans ,Prospective Studies ,Mortality ,Prospective cohort study ,Aged ,Mechanical ventilation ,urogenital system ,SARS-CoV-2 ,business.industry ,Incidence ,Incidence (epidemiology) ,Mortality rate ,Age Factors ,Acute kidney injury ,COVID-19 ,Hematology ,General Medicine ,Emergency department ,Acute Kidney Injury ,Middle Aged ,Prognosis ,medicine.disease ,Comorbidity ,female genital diseases and pregnancy complications ,Hospitalization ,Nephrology ,Female ,SOFA score ,business ,Research Article - Abstract
Introduction: Acute kidney injury (AKI) is common in coronavirus disease 2019 (COVID-19). It is unknown if hospital-acquired AKI (HA-AKI) and community-acquired AKI (CA-AKI) convey a distinct prognosis. Methods: The study aim was to evaluate the incidence and risk factors associated with both CA-AKI and HA-AKI. Consecutive patients hospitalized at a reference center for COVID-19 were included in this prospective cohort study. Results: We registered 349 (30%) AKI episodes in 1,170 hospitalized patients, 224 (19%) corresponded to CA-AKI, and 125 (11%) to HA-AKI. Compared to patients with HA-AKI, subjects with CA-AKI were older (61 years [IQR 49–70] vs. 50 years [IQR 43–61]), had more comorbidities (hypertension [44 vs. 26%], CKD [10 vs. 3%]), higher Charlson Comorbidity Index (2 points [IQR 1–4] vs. 1 point [IQR 0–2]), and presented to the emergency department with more severe disease. Mortality rates were not different between CA-AKI and HA-AKI (119 [53%] vs. 63 [50%], p = 0.66). In multivariate analysis, CA-AKI was strongly associated to a history of CKD (OR 4.17, 95% CI 1.53–11.3), hypertension (OR 1.55, 95% CI 1.01–2.36), Charlson Comorbidity Index (OR 1.16, 95% CI 1.02–1.32), and SOFA score (OR 2.19, 95% CI 1.87–2.57). HA-AKI was associated with the requirement for mechanical ventilation (OR 68.2, 95% CI 37.1–126), elevated troponin I (OR 1.95, 95% CI 1.01–3.83), and glucose levels at admission (OR 1.05, 95% CI 1.02–1.08). Discussion/Conclusions: CA-AKI and HA-AKI portend an adverse prognosis in COVID-19. Nevertheless, CA-AKI was associated with a higher comorbidity burden (including CKD and hypertension), while HA-AKI occurred in younger patients by the time severe multiorgan disease developed.
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- 2021
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17. In Vitro and In Vivo Genetic Disease Modeling via NHEJ-Precise Deletions Using CRISPR-Cas9
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Joanne C. Mountford, Rebeca Sanchez-Dominguez, Isabel Ojeda-Perez, Raul M. Torres, Gloria González-Aseguinolaza, Juan C. Ramirez, Aída Garcia-Torralba, Nerea Zabaleta, Sergio López-Manzaneda, Laura Torella, José C. Segovia, Emmanuel Olivier, Juan A. Bueren, and Omaira Alberquilla
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0301 basic medicine ,lcsh:QH426-470 ,Disease ,Computational biology ,Genome ,03 medical and health sciences ,Endonuclease ,0302 clinical medicine ,Genome editing ,Genetics ,medicine ,CRISPR ,lcsh:QH573-671 ,Molecular Biology ,Gene ,biology ,lcsh:Cytology ,medicine.disease ,lcsh:Genetics ,030104 developmental biology ,030220 oncology & carcinogenesis ,biology.protein ,Molecular Medicine ,Original Article ,Cellular model ,Pyruvate kinase deficiency - Abstract
The development of advanced gene and cell therapies for the treatment of genetic diseases requires reliable animal and cellular models to test their efficacy. Moreover, the availability of the target human primary cells of these therapies is reduced in many diseases. The development of endonucleases that can cut into specific sites of the cell genome, as well as the repair of the generated break by non-homologous end-joining, results in a variety of outcomes, insertions, deletions, and inversions that can induce the disruption of any specific gene. Among the many methods that have been developed for gene editing, CRISPR-Cas9 technology has become one of the most widely used endonuclease tools due to its easy design and its low cost. It has also been reported that the use of two guides, instead of just the one required, reduces the outcomes of non-homologous end joining mainly to the precise genomic sequences between the cutting sites of the guides used. We have explored this strategy to generate useful cellular and animal models. Different distances between the two guides have been tested (from 8 to 500 bp apart), and using the optimal range of 30–60 bp we have obtained a human primary cellular model of a genetic disease, pyruvate kinase deficiency, where the availability of the target cells is limited. We have also generated an in vivo model of glycolate oxidase (GO) deficiency, which is an enzyme involved in the glyoxylate metabolism following the same strategy. We demonstrate that the use of two-guide CRISPR-Cas9-induced non-homologous end joining is a feasible and useful tool for disease modeling, and it is most relevant to those diseases in which it is difficult to get the cells that will be genetically manipulated., Graphical Abstract, A CRISPR-Cas9 system generates precise deletions (up to 90% efficiency) when two guides are used simultaneously by means of non-homologous end joining. The PAM-in/PAM-in Cas9 orientation is the best combination to generate precise deletions. This gene-editing procedure facilitates the generation of homogeneously genetically defined cell and animal models.
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- 2020
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18. Coronary Artery Calcium Evaluation Using New Generation Photon-counting Computed Tomography Yields Lower Radiation Dose Compared With Standard Computed Tomography
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Fides R. Schwartz, Melissa A. Daubert, Lior Molvin, Juan C. Ramirez-Giraldo, Ehsan Samei, Daniele Marin, and Tina D. Tailor
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Pulmonary and Respiratory Medicine ,Radiology, Nuclear Medicine and imaging - Abstract
Prospective head-to-head comparison of coronary calcium scores between standard computed tomography (CT) and photon-counting CT show no significant differences, while photon-counting CT administers substantially lower radiation dose.
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- 2022
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19. Longitudinal Changes of Serum Creatine Kinase and Acute Kidney Injury among Patients with Severe COVID-19
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Juan M. Soto-Fajardo, Valeria J. Castillo-Avalos, Elisa Naomi Hernandez-Paredes, Airy Santillán-Cerón, Jorge E. Gaytan-Arocha, Olynka Vega-Vega, Norma Uribe, Ricardo Correa-Rotter, and Juan C. Ramirez-Sandoval
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Article Subject ,Nephrology ,urologic and male genital diseases ,female genital diseases and pregnancy complications - Abstract
Background. Acute kidney injury (AKI) is a common complication of COVID-19. Several etiologies have been identified, including pigment deposition likely associated with myopathic damage. Nevertheless, the relationship between longitudinal creatine-kinase trends and renal outcomes is uncertain. Aim. To correlate longitudinal changes in serum creatine-kinase levels with hospital-acquired AKI (beyond 48 h of hospital admission) in severe COVID-19 patients. Methods. This is a retrospective cohort study, and creatine-kinase levels were assessed over time in 1551 hospitalized patients with normal renal function at the time of hospital admission. Results. In subjects who developed hospital-acquired AKI (n = 126, 8.1%), the serum creatine-kinase concentration before AKI onset was not different when compared to patients without AKI (slope of log creatine-kinase/day = −0.09 [95% CI −0.17 to +0.19] vs. +0.03 [95% CI −0.1 to +0.1]). After AKI diagnosis, serum creatine-kinase levels showed a significantly ascendent slope (slope of log creatine-kinase/day after AKI diagnosis = +0.14; 95% CI + 0.05 to +0.3). The AKI evolution was the main factor associated with the creatine-kinase trend. Subjects with persistent AKI (n = 40, 32%) had rising creatine-kinase levels during hospitalization (slope of log creatine-kinase/day = +0.30 95% CI + 0.19 to +0.51). A rising creatine-kinase trend (n = 114, 8%) was associated with a 1.89-fold higher risk of in-hospital death (95% CI 1.14 to 3.16). Nevertheless, this association disappeared after adjusting AKI evolution and LDH baseline levels. Conclusion. In severe COVID-19 patients, a slight increase in creatine-kinase levels was observed after AKI occurrence but not before. Our results show that, at least for the appearance of hospital-acquired AKI, the CK rise does not meet the temporality criterion of causality regarding the occurrence of AKI. Rising creatine-kinase trends were associated with a higher risk of mortality, but this association was modified by AKI evolution and inflammation. There is a limited efficiency for AKI prognosis in the serial follow-up of CK levels in severe COVID-19 patients with normal renal function.
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- 2022
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20. Interoperator reliability of an on-site machine learning-based prototype to estimate CT angiography-derived fractional flow reserve
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Yushui Han, Ahmed Ibrahim Ahmed, Chris Schwemmer, Myra Cocker, Talal S Alnabelsi, Jean Michel Saad, Juan C Ramirez Giraldo, and Mouaz H Al-Mallah
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Fractional Flow Reserve, Myocardial ,Machine Learning ,Computed Tomography Angiography ,Coronary Stenosis ,Humans ,Reproducibility of Results ,Cardiology and Cardiovascular Medicine ,Coronary Angiography ,Severity of Illness Index - Abstract
BackgroundAdvances in CT and machine learning have enabled on-site non-invasive assessment of fractional flow reserve (FFRCT).PurposeTo assess the interoperator and intraoperator variability of coronary CT angiography-derived FFRCT using a machine learning-based postprocessing prototype.Materials and methodsWe included 60 symptomatic patients who underwent coronary CT angiography. FFRCT was calculated by two independent operators after training using a machine learning-based on-site prototype. FFRCT was measured 1 cm distal to the coronary plaque or in the middle of the segments if no coronary lesions were present. Intraclass correlation coefficient (ICC) and Bland-Altman analysis were used to evaluate interoperator variability effect in FFRCT estimates. Sensitivity analysis was done by cardiac risk factors, degree of stenosis and image quality.ResultsA total of 535 coronary segments in 60 patients were assessed. The overall ICC was 0.986 per patient (95% CI 0.977 to 0.992) and 0.972 per segment (95% CI 0.967 to 0.977). The absolute mean difference in FFRCT estimates was 0.012 per patient (95% CI for limits of agreement: −0.035 to 0.039) and 0.02 per segment (95% CI for limits of agreement: −0.077 to 0.080). Tight limits of agreement were seen on Bland-Altman analysis. Distal segments had greater variability compared with proximal/mid segments (absolute mean difference 0.011 vs 0.025, pConclusionA high degree of interoperator and intraoperator reproducibility can be achieved by on-site machine learning-based FFRCT assessment. Future research is required to evaluate the physiological relevance and prognostic value of FFRCT.
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- 2021
21. Molecular Imaging of Vulnerable Coronary Plaque with Radiolabeled Somatostatin Receptors (SSTR)
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Juan C. Ramirez, Luz Kelly Anzola, Fernando Mut, Alberto Signore, and Jose Nelson Rivera
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PET-CT ,Pathology ,medicine.medical_specialty ,business.industry ,Somatostatin receptor ,PET/CT ,activated macrophages ,General Medicine ,Disease ,Review ,Pathophysiology ,68Ga-DOTA-TATE ,Somatostatin ,Coronary plaque ,Medicine ,vascular inflammation ,Molecular imaging ,atherosclerosis ,business ,Receptor - Abstract
Atherosclerosis is responsible for the majority of heart attacks and is characterized by several modifications of the arterial wall including an inflammatory reaction. The silent course of atherosclerosis has made it necessary to develop predictors of disease complications before symptomatic lesions occur. Vulnerable to rupture atherosclerotic plaques are the target for molecular imaging. To this aim, different radiopharmaceuticals for PET/CT have emerged for the identification of high-risk plaques, with high specificity for the identification of the cellular components and pathophysiological status of plaques. By targeting specific receptors on activated macrophages in high-risk plaques, radiolabelled somatostatin analogues such as 68Ga-DOTA-TOC, TATE,0 or NOC have shown high relevance to detect vulnerable, atherosclerotic plaques. This PET radiopharmaceutical has been tested in several pre-clinical and clinical studies, as reviewed here, showing an important correlation with other risk factors.
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- 2021
22. ORIGINAL ARTICLEVery Low Vitamin D Levels are a Strong Independent Predictor of Mortality in Hospitalized Patients with Severe COVID-19
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Airy Santillan-Ceron, Roopa Mehta, Juan C. Ramirez-Sandoval, Armando Paz-Cortes, Ricardo Correa-Rotter, Valeria Jocelyne Castillos-Ávalos, and Sergio Hernández-Jiménez
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medicine.medical_specialty ,Coronavirus disease 2019 (COVID-19) ,Hospitalized patients ,business.industry ,SARS-CoV-2 ,Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) ,COVID-19 ,Retrospective cohort study ,General Medicine ,medicine.disease ,Independent predictor ,25-hydroxyvitamin D ,mortality ,vitamin D deficiency ,Article ,Pneumonia ,Internal medicine ,medicine ,Vitamin D and neurology ,Humans ,Hospital Mortality ,length of hospital stay ,Vitamin D ,business ,Retrospective Studies - Abstract
Background . There is controversy regarding the association between hypovitaminosis D and COVID-19 outcomes. Aim of the study . We assessed the association between 25-hydroxyvitamin D levels and COVID-19 outcomes in hospitalized subjects with severe SARS-CoV-2 infection. Methods . Retrospective cohort study. Serum 25-hydroxyvitamin D levels of subjects with severe COVID-19 pneumonia were measured at hospital admission, between March 17th, 2020, and March 1st, 2021. Results . Out of 2,908 patients, 571 (19.6%) had vitamin D deficiency (defined as a serum 25-hydroxyvitamin D level
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- 2021
23. Algoritmo de diagnóstico y tratamiento del hiperparatiroidismo secundario en la enfermedad renal crónica avanzada
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Ricardo Correa-Rotter, Rafael Valdez-Ortiz, Magdalena Madero, Odette Díaz, Gregorio T. Obrador-Vera, Juan C. Ramirez-Sandoval, Antonio Méndez-Durán, and Ernesto Lopez-Almaraz
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Special situations and conditions ,Hiperparatiroidismo. Enfermedad renal crónica. Calcio. Fósforo. Hormona paratiroidea. Fracturas ,RC952-1245 - Abstract
El hiperparatiroidismo secundario grave relacionado con la enfermedad renal crónica avanzada es una complicación acompañada de morbimortalidad cuyo diagnóstico y tratamiento son complejos. La interpretación de las mediciones de la hormona paratiroidea molécula intacta y las opciones terapéuticas con calcimiméticos, vitamina D, paratiroidectomía o maniobras mixtas se presentan en un algoritmo clínico para los pacientes con enfermedad renal crónica avanzada sin diálisis y para aquellos bajo tratamiento sustitutivo de la función renal.
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- 2021
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24. Inter-Operator Reliability of an Onsite Machine Learning-Based Prototype to Estimate Ct Angiography-Derived Fractional Flow Reserve
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Yushui Han, Ahmed Ibrahim Ahmed, Chris Schwemmer, Myra Cocker, Talal S Alnabelsi, Jean michel Saad, Juan C Ramirez Giraldo, and Mouaz H Al-Mallah
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Background: Advances in computed tomography (CT) and machine learning have enabled on-site non-invasive assessment of fractional flow reserve (FFRCT). Purpose: To assess the inter-operator variability of Coronary CT Angiography–derived FFRCT using a machine learning based post-processing prototype.Materials and Methods: We included 60 symptomatic patients who underwent coronary CT angiography. FFRCT was calculated by 2 independent operators after training using a machine learning based on-site prototype. FFRCT was measured 1 cm distal to the coronary plaque or in the middle of the segments if no coronary lesions were present. Intraclass correlation coefficient (ICC) and Bland-Altman analysis were used to evaluate inter-operator variability effect in FFRCT estimates. Sensitivity analysis was done by cardiac risk factors, degree of stenosis and image quality. Results: A total of 535 coronary segments in 60 patients were assessed. The overall ICC was 0.986 per patient (95% CI: 0.977 - 0.992) and 0.972 per segment (95% CI: 0.967 - 0.977). The absolute mean difference in FFRCT estimates was 0.012 per patient (95% CI for limits of agreement: -0.035 - 0.039) and 0.02 per segment (95% CI for limits of agreement: -0.077 - 0.080). Tight limits of agreement were seen on Bland-Altman analysis. Distal segments had greater variability compared to proximal/mid segments (absolute mean difference 0.011 vs 0.025, pConclusion: A high degree of inter-operator reproducibility can be achieved by onsite machine learning based FFRCT assessment. Future research is required to evaluate the physiological relevance and prognostic value of FFRCT.
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- 2021
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25. Epigenetic reprogramming of primary pancreatic cancer cells counteracts their in vivo tumourigenicity
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Hossein Baharvand, Mehdi Totonchi, Raul Torres, Alexandra Aicher, Reyhaneh Khoshchehreh, Juan C. Ramirez, Christopher Heeschen, and Marzieh Ebrahimi
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Male ,0301 basic medicine ,Cancer Research ,endocrine system diseases ,Carcinogenesis ,Primary Cell Culture ,Mice, Nude ,Biology ,Article ,Epigenesis, Genetic ,Mice ,03 medical and health sciences ,0302 clinical medicine ,Pancreatic cancer ,microRNA ,Genetics ,medicine ,Animals ,Humans ,Epigenetics ,Neoplasm Metastasis ,Molecular Biology ,Cells, Cultured ,Regulation of gene expression ,Mice, Inbred BALB C ,HEK 293 cells ,Cellular Reprogramming ,Embryo, Mammalian ,medicine.disease ,Gene Expression Regulation, Neoplastic ,Mice, Inbred C57BL ,Pancreatic Neoplasms ,Transplantation ,HEK293 Cells ,030104 developmental biology ,030220 oncology & carcinogenesis ,Cancer cell ,Cancer research ,Reprogramming ,Carcinoma, Pancreatic Ductal - Abstract
Pancreatic ductal adenocarcinoma (PDAC) arises through accumulation of multiple genetic alterations. However, cancer cells also acquire and depend on cancer-specific epigenetic changes. To conclusively demonstrate the crucial relevance of the epigenetic programme for the tumourigenicity of the cancer cells, we used cellular reprogramming technology to reverse these epigenetic changes. We reprogrammed human PDAC cultures using three different techniques – (1) lentivirally via induction of Yamanaka Factors (OSKM), (2) the pluripotency-associated gene OCT4 and the microRNA mir-302, or (3) using episomal vectors as a safer alternative without genomic integration. We found that induction with episomal vectors was the most efficient method to reprogram primary human PDAC cultures as well as primary human fibroblasts that served as positive controls. Successful reprogramming was evidenced by immunostaining, alkaline phosphatase staining, and real-time PCR. Intriguingly, reprogramming of primary human PDAC cultures drastically reduced their in vivo tumourigenicity, which appeared to be driven by the cells’ enhanced differentiation and loss of stemness upon transplantation. Our study demonstrates that reprogrammed primary PDAC cultures are functionally distinct from parental PDAC cells resulting in drastically reduced tumourigenicity in vitro and in vivo. Thus, epigenetic alterations account at least in part for the tumourigenicity and aggressiveness of pancreatic cancer, supporting the notion that epigenetic modulators could be a suitable approach to improve the dismal outcome of patients with pancreatic cancer.
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- 2019
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26. Radiation-Induced Malignant Transformation of Preneoplastic and Normal Breast Primary Epithelial Cells
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David Soler, Teresa Anglada, Mariona Terradas, Juan C. Ramirez, Anna Genescà, and Joan Repullés
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0301 basic medicine ,Cancer Research ,Neoplasms, Radiation-Induced ,Cell ,Breast Neoplasms ,medicine.disease_cause ,Ionizing radiation ,Malignant transformation ,03 medical and health sciences ,Transduction (genetics) ,0302 clinical medicine ,medicine ,Humans ,Telomerase reverse transcriptase ,Neoplastic transformation ,Breast ,Molecular Biology ,Chemistry ,Cancer ,Epithelial Cells ,medicine.disease ,Cell Transformation, Neoplastic ,030104 developmental biology ,medicine.anatomical_structure ,Oncology ,030220 oncology & carcinogenesis ,Cancer research ,Female ,Carcinogenesis ,Precancerous Conditions - Abstract
Radiation is used in multiple procedures as a therapeutic and diagnostic tool. However, ionizing radiation can induce mutations in the DNA of irradiated cells, which can promote tumorigenesis. As malignant transformation is a process that takes many years, there are intermediate stages of cells that have initiated the process but have not yet evolved into cancer. The study here aimed to investigate the effect of ionizing radiation on normal and partially transformed human mammary epithelial cells. Breast primary epithelial cells were derived from normal breast tissue from two different donors and modified by transduction with the SV40 small and large T antigen and hTERT genes to obtain partially transformed cells and also with HRAS to completely and experimentally transform them. After exposure to different doses of ionizing radiation, oncogenic features were analyzed by means of an anchorage-independent growth assay and 3D cell culture. The addition of radiation exposure resulted in an increase in the number and size of colonies formed in each of the conditions analyzed and in the reduction of the capacity of partially transformed cells to form properly polarized 3D structures. Moreover, partially transformed cells require lower doses of radiation than healthy cells to enhance anchorage-independent growth capacity. Although cells from different donors have a different degree of sensitivity in the response to radiation, a higher sensitivity to the radiation-induced cell transformation process was observed in those cells that had already initiated the oncogenic process, which require higher doses of radiation to complete the transformation process. Implications: Individuals carrying accumulation of genetic alterations may have an increased susceptibility to radiation-induced neoplastic transformation.
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- 2019
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27. Cholecalciferol supplementation increases FGF23 in peritoneal dialysis patients with hypovitaminosis D: a randomized clinical trial
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Luis J Rojas-Concha, Fagundo Reynerio, Mauricio Arvizu-Hernandez, Luis Tamez, Cristino Cruz, Ricardo Correa-Rotter, Juan C. Ramirez-Sandoval, F. Enrique Gomez, and Barbara Vazquez-Cantu
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Adult ,Male ,Nephrology ,medicine.medical_specialty ,medicine.medical_treatment ,Osteocalcin ,030232 urology & nephrology ,030204 cardiovascular system & hematology ,Carotid Intima-Media Thickness ,Gastroenterology ,vitamin D deficiency ,End stage renal disease ,law.invention ,Peritoneal dialysis ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Double-Blind Method ,Randomized controlled trial ,law ,Internal medicine ,Vitamin D and neurology ,Humans ,Medicine ,Prospective Studies ,Renal Insufficiency, Chronic ,Vitamin D ,Dialysis ,Aged ,Cholecalciferol ,Interleukin-6 ,business.industry ,Osteoprotegerin ,Vitamins ,Middle Aged ,Vitamin D Deficiency ,medicine.disease ,Fibroblast Growth Factors ,Fibroblast Growth Factor-23 ,chemistry ,Parathyroid Hormone ,Dietary Supplements ,Female ,Osteopontin ,business ,Peritoneal Dialysis ,Biomarkers - Abstract
Vitamin D deficiency is common in peritoneal dialysis (PD) patients, so its supplementation has been advocated as potentially beneficial.Double-blind, placebo-controlled, randomized clinical trial. Subjects on PD treated with high calcium peritoneal dialysate (Ca 3.5 mEq/l) and serum levels of 25-hydroxi vitamin D (25D) 20 ng/ml were randomized to receive cholecalciferol (4800 IU/daily) or placebo for 16 weeks. The outcome measures were the effects on the osteogenic biomarkers osteoprotegerin (primary endpoint), intact fibroblast growth factor-23 (iFGF23), osteocalcin, osteopontin, iPTH, 1,25-dyhydroxivitamin D (1,25D), and interleukin-6.Fifty-eight subjects were randomly assigned. Baseline characteristics were similar in both groups. Cholecalciferol supplemented subjects had a significant increase in serum 25D (from 11.4 ± 5.0 to 28.3 ± 10.3 ng/ml), 1,25D and iFGF23 compared with placebo group. iFGF23 levels increased an average of 10,875 pg/ml per month (95% CI 11,778-88,414) in the cholecalciferol group and was unchanged in the placebo group (2829 pg/ml, 95% CI - 2181 to 14,972). Extremely high iFGF23 levels ( 30,000 pg/ml) were observed in 74% of subjects receiving cholecalciferol although iFGF23 returned to baseline values after 32 weeks of withdrawal. The observed changes in iFGF23 correlated with 1,25D levels and were not modified by other variables. No difference was observed between groups in osteoprotegerin or other osteogenic biomarkers levels.Cholecalciferol supplementation increases serum 25D levels in subjects on PD exposed to high calcium dialysate, yet it induces an exponential increase of iFGF23 in most patients, which disappear after withdrawal of supplementation and may be a major concern for this maneuver.
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- 2019
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28. Validation of an equation for free calcium estimation: accuracy improves after adjustment for phosphate and CO
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Juan C, Ramirez-Sandoval, Pablo, Diener-Cabieses, Fabián, Gutiérrez-Valle, Sofía, Ley-Tapia, Santiago, Pastrana-Brandes, Pablo E, Galindo, Reynerio, Fagundo, Mauricio, Moreno-Yañez, Alfredo Adolfo, Reza-Albarrán, and Ricardo, Correa-Rotter
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Cohort Studies ,Humans ,Calcium ,Carbon Dioxide ,Serum Albumin ,Phosphates ,Retrospective Studies - Abstract
Free calcium is the gold standard for diagnosis of calcium disorders, although calcium assessment is routinely performed by albumin-adjusted calcium. Our objective was to develop a novel-specific correction equation for free calcium employing serum total calcium and other analytes.Retrospective single-center cohort study. A new equation for free calcium assessment was formulated from data of hospitalized patients (n = 3481, measurements = 7157) and tested in a validation cohort (n = 3218, measurements = 6911). All measurements were performed simultaneously from the same blood draw.Total COThe novel equation proposed for prediction of free calcium could be useful when free calcium is not available. The conventional formulas misclassify many patients, in particular when phosphate or bicarbonate disturbances are present.
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- 2021
29. Inter-Operator Reliability of an Onsite Machine Learning-Based Prototype to Estimate Ct Angiography-Derived Fractional Flow Reserve
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Han, Yushui, primary, Ahmed, Ahmed Ibrahim, additional, Schwemmer, Chris, additional, Cocker, Myra, additional, Alnabelsi, Talal S, additional, Saad, Jean michel, additional, Giraldo, Juan C Ramirez, additional, and Al-Mallah, Mouaz H, additional
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- 2021
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30. (E)-1,1-Diphenyl-2-(thiophen-2-ylmethylidene)hydrazine
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Blanca M. Cabrera-Vivas, Marcos Flores-Alamo, Ruth Meléndrez-Luévano, Lidia Meléndez-Balbuena, and Juan C. Ramirez
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Crystallography ,QD901-999 - Abstract
The asymmetric unit of the title compound, C17H14N2S, consists of two crystallographically independent molecules with similar conformations. The dihedral angles between the phenyl rings are 89.32 (5) and 82.80 (5)° in the two molecules. In the crystal, molecules are linked by C—H...π interactions, forming a three-dimensional network.
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- 2014
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31. (E)-1-(2,4-Dinitrobenzylidene)-2,2-diphenylhydrazine
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Ruth Meléndrez-Luévano, Blanca M. Cabrera-Vivas, Marcos Flores-Alamo, Juan C. Ramirez, and Pedro Conde-Sánchez
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Crystallography ,QD901-999 - Abstract
In the crystal of the title compound, C19H14N4O4, the asymmetric unit consists of two discrete molecules. The C=N bonds in both molecules show an E conformation. The dihedral angles between the C atoms of the 2,4-dinitrobenzene rings and the C=N—N planes are 13.52 (9) and 13.82 (9)° for the two molecules. In the crystal, C—H...O hydrogen bonds, mainly between the phenyl ring and the nitro group along the b axis.
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- 2013
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32. Clinical factors associated with early and persistent hypocalcaemia after parathyroidectomy in patients on dialysis with severe hyperparathyroidism
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Juan Pablo Pantoja-Millán, Miguel F. Herrera, Luis J Rojas-Concha, Airy Santillan-Ceron, Luis Tamez-Pedroza, Jorge I Fonseca-Correa, Mauricio Sierra-Salazar, David Velázquez-Fernández, Carlos Nava-Santana, Juan C. Ramirez-Sandoval, Armando Paz-Cortes, and Ricardo Correa-Rotter
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musculoskeletal diseases ,Parathyroidectomy ,Adult ,Male ,medicine.medical_specialty ,Time Factors ,endocrine system diseases ,medicine.medical_treatment ,030232 urology & nephrology ,030204 cardiovascular system & hematology ,Tertiary hyperparathyroidism ,Gastroenterology ,Severity of Illness Index ,End stage renal disease ,Cohort Studies ,03 medical and health sciences ,0302 clinical medicine ,Postoperative Complications ,Renal Dialysis ,Risk Factors ,Internal medicine ,medicine ,Humans ,Hypocalcaemia ,Dialysis ,Retrospective Studies ,Hyperparathyroidism ,Hypocalcemia ,business.industry ,General Medicine ,Middle Aged ,medicine.disease ,Nephrology ,Female ,business ,Hypophosphatemia ,Primary hyperparathyroidism - Abstract
AIM Severe hypocalcaemia following parathyroidectomy for secondary or tertiary hyperparathyroidism (SHPT/THPT) is scarcely studied. We aimed to describe and identify risk factors for early and persistent hypocalcaemia after parathyroidectomy. METHODS Retrospective pair-matched cohort study. We assessed 87 dialysis patients with SHPT (n = 73) or THPT (n = 14) paired with 146 subjects with primary hyperparathyroidism (PHPT) who underwent parathyroidectomy and were followed for 12 months. Early severe hypocalcaemia was defined as a free Ca ≤0.8 mmol/L [3.2 mg/dl] or corrected Ca ≤1.87 mmol/L [7.5 mg/dl] within 48 h. After parathyroidectomy and persistent hypocalcaemia, as an elemental Ca intake >3.0 g/day to achieve corrected Ca >2 mmol/L [8.0 mg/dl]. RESULTS Early severe hypocalcaemia occurred in 77% (67/87) versus 6.8% (10/146) of subjects with SHPT/THPT and PHPT, respectively (p
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- 2021
33. Adequate Lubrication As the First (and Often Only) Line of Defense Against Dust Explosions in Grain Elevators
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Kamal Aljazireh, James F. Lane, and Juan C. Ramirez
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Defense industry ,Elevator ,Mining engineering ,law ,Lubrication ,Environmental science ,Grain elevator ,Line (text file) ,Dust explosion ,law.invention - Abstract
Finely divided solid materials (e.g., dusts and fines), when dispersed in the air, can fuel particularly violent and destructive explosions. In this paper we will discuss a case study involving a dust explosion in a grain elevator and how a careful bearing greasing policy could have avoided it. We present the most common conditions that lead to bearing overheating which can serve as the ignition source for a dust explosion. Additionally, we stress the need to raise awareness among operators about the wide variety of greases available, and given this wide variety, it is critical for facilities to ensure they use a grease with characteristics as close as possible as these recommended by the equipment manufacturer.
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- 2020
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34. P1396EFFECT OF MIXED VERSUS ANIMAL-BASED LOW PHOSPHORUS DIETS IN DIALYSIS PATIENTS ON INTACT FGF23 LEVELS: A RANDOMIZED CLINICAL TRIAL
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Jorge Sánchez-Silva, Ricardo Correa-Rotter, Juan C. Ramirez-Sandoval, Miguel León, Ximena Atilano-Carsi, Luis Tamez-Pedroza, Cristino Cruz, Celene Viridiana Arce-Santander, Pamela Basulto-Sosa, and Ángeles Espinosa-Cuevas
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Fibroblast growth factor 23 ,Transplantation ,medicine.medical_specialty ,business.industry ,medicine.medical_treatment ,Phosphorus ,chemistry.chemical_element ,Dialysis patients ,medicine.disease ,Gastroenterology ,Peritoneal dialysis ,law.invention ,chemistry ,Randomized controlled trial ,Nephrology ,law ,Internal medicine ,medicine ,Vitamin D and neurology ,Hemodialysis ,business ,Hypophosphatemia - Abstract
Background and Aims The FGF23-lowering effect of different phosphate-sources (vegetable versus animal) in low-phosphorus diets are scarcely known. In this trial, we assess the effect on intact FGF23 (iFGF23) of two low-phosphorus diets, animal versus mixed (vegetable + animal), in dialysis patients. Method A randomized, two-center, open-label, clinical trial was performed. Subjects on stable dialysis for >6 months with P>4.5 mg/dL were randomized into a mixed-based (3 ounces equivalent of animal protein + 3 ounces equivalent of legumes) vs. animal-based (6 ounce equivalent of animal protein) low phosphorus diet with equivalent nutrients (phosphorus Results 556 subjects were screened, only 57 subjects (37 hemodialysis[HD] and 18 peritoneal dialysis[PD]) were randomized. Age, sex, phosphate-binders use, and other baseline characteristics were similar between groups. Baseline iFGF23 levels were 7394 (IQR 2379-16629) and 6859 (1543-17521) ng/mL in mixed-based and animal-based groups respectively (p=0.62). Both groups had a significant decrease in iFGF23 after 12 weeks of intervention (iFGF23 change: -285 [IQR -3002 to 227] ng/mL, p Conclusion Dietary phosphorus restriction for 12 weeks with animal-based or mixed-based phosphorus sources similarly decreases iFGF23 concentration in HD or PD patients.
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- 2020
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35. Prolonged Intermittent Renal Replacement Therapy for Acute Kidney Injury in COVID-19 Patients with Acute Respiratory Distress Syndrome
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Jorge E. Gaytan-Arocha, Carlos Torruco-Sotelo, Mauricio Arvizu-Hernandez, Olynka Vega-Vega, Pedro Xolalpa-Chávez, Ricardo Correa-Rotter, Eduardo Rivero-Sigarroa, Juan M. Mejia-Vilet, and Juan C. Ramirez-Sandoval
- Subjects
Adult ,Male ,ARDS ,Continuous Renal Replacement Therapy ,Critical Care ,medicine.medical_treatment ,030232 urology & nephrology ,Comorbidity ,030204 cardiovascular system & hematology ,Intermittent Renal Replacement Therapy ,law.invention ,Diabetes Complications ,03 medical and health sciences ,Norepinephrine ,0302 clinical medicine ,Interquartile range ,law ,medicine ,Humans ,Vasoconstrictor Agents ,Renal replacement therapy ,Prospective Studies ,Aged ,Mechanical ventilation ,Respiratory Distress Syndrome ,business.industry ,SARS-CoV-2 ,Acute kidney injury ,COVID-19 ,Hematology ,General Medicine ,Acute Kidney Injury ,Middle Aged ,medicine.disease ,Intensive care unit ,Respiration, Artificial ,Treatment Outcome ,Tolerability ,Respiratory failure ,Nephrology ,Anesthesia ,Hypertension ,Female ,Hypotension ,business - Abstract
Introduction: Patients with acute respiratory distress syndrome (ARDS) secondary to COVID-19 frequently develop severe acute kidney injury (AKI). Although continuous renal replacement therapy is the standard of care for critically ill patients, prolonged intermittent renal replacement therapy (PIRRT) may be a feasible option. We aimed to describe the tolerability and security of PIRRT treatments in COVID-19 patients with ARDS who required mechanical ventilation and developed severe AKI. Methods: We prospectively analyzed patients who underwent PIRRT treatments at a COVID-19 reference hospital in Mexico City. Intradialytic hypotension was defined as a systolic blood pressure decrease of ≥20 mm Hg or an increase of 100% in vasopressor dose. Results: We identified 136 AKI cases (60.7%) in 224 patients admitted to the intensive care unit. Among them, 21 (15%) underwent PIRRT (130 sessions) due to stage 3 AKI. The median age of the cohort was 49 (range 36–73) years, 17 (81%) were male, 7 (33%) had diabetes, and the median time between symptoms onset and PIRRT initiation was 12 (interquartile range [IQR] 7–14) days. The median of PIRRT procedures for each patient was 5 (IQR 4–9) sessions. In 108 (83%) PIRRT sessions, the total ultrafiltration goal was achieved. In 84 (65%) PIRRT procedures, there was a median increase in norepinephrine dose of +0.031 mcg/kg/min during PIRRT (IQR 0.00 to +0.07). Intradialytic hypotensive events occurred in 56 (43%) procedures. Fifteen (12%) PIRRT treatments were discontinued due to severe hypotension. Vasopressor treatment at PIRRT session onset (OR 6.2, 95% CI 1.4–28.0, p: 0.02) and a pre-PIRRT lactate ≥3.0 mmol/L (OR 4.63, 95% CI 1.3–12.8, p: 0.003) were independently and significantly associated with the risk of hypotension during PIRRT. During follow-up, 11 patients (52%) recovered from AKI and respiratory failure and 9 (43%) died. Several adaptations to our PIRRT protocol during the COVID-19 outbreak are presented. Conclusions: PIRRT was feasible in the majority of COVID-19 patients with ARDS and severe AKI, despite frequent transitory intradialytic hypotensive episodes. PIRRT may represent an acceptable alternative of renal replacement therapy during the COVID-19 outbreak.
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- 2020
36. In vitro and In vivo Genetic Disease Modelling via NHEJ-precise deletions using CRISPR/Cas9
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Sergio López-Manzaneda, Laura Torella, Raul M. Torres, Isabel Ojeda-Perez, Nerea Zabaleta, José C. Segovia, Juan C. Ramirez, Juan A. Bueren, Omaira Alberquilla, Rebeca Sanchez-Dominguez, Joanne C. Mountford, Aída Garcia-Torralba, Emmanuel Olivier, and Gloria González-Aseguinolaza
- Subjects
Endonuclease ,biology ,In vivo ,Base pair ,Cas9 ,biology.protein ,medicine ,CRISPR ,Computational biology ,medicine.disease ,Gene ,Genome ,Pyruvate kinase deficiency - Abstract
Development of advanced gene and cell therapies for the treatment of genetic diseases requires confident animal and cellular models to test their efficacy and is crucial in the cases where no primary samples from patients are available. CRISPR/Cas9 technology, has become one of the most spread endonuclease tools for editing the genome at will. Moreover, it is known that the use of two guides tends to produce the precise deletion between the guides via NHEJ. Different distances between guides were tested (from 8 to 500 base pairs). We found that distances between the two cutting sites and orientation of Cas9 protein-DNA interaction are important for the efficiency within the optimal range (30-60 bp), we could obtain new genetically reproducible models for two rare disease, a Pyruvate Kinase Deficiency model, using human primary cells, and a (forin vivoprimary hyperoxaluria therapeutic mouse model. We demonstrate that the use of a 2-guideRNAs at the optimal distance and orientation is a powerful strategy for disease modelling in those diseases where the availability of primary cells is limited.
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- 2020
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37. Lentiviral Gene Therapy for the Correction of Congenital Dyserythropoietic Anemia Type II
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Veronica Venturi, Paola Bianchi, Juan C. Ramirez, Sara Fañanas-Baquero, José C. Segovia, Mercedes Dessy-Rodriguez, Cristian Tornador, Mayka Sanchez, Oscar Quintana Bustamante, Salvador Payan, and Gonzalo Hernández
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Congenital dyserythropoietic anemia type II ,business.industry ,Genetic enhancement ,Immunology ,Cancer research ,Medicine ,Cell Biology ,Hematology ,business ,medicine.disease ,Biochemistry - Abstract
Congenital dyserythropoietic anemias (CDAs) are a group of inherited anemias that affect the development of the erythroid lineage. CDA type II is the most common one: it accounts for around 60% of all cases, and more than 600 cases have been reported so far. CDA II is caused by biallelic mutations in the SEC23B gene and is characterized by ineffective erythropoiesis with morphologic abnormalities of erythroblasts, hemolysis, and secondary iron overload, which is the most frequent complication. Patients usually suffer from variable degrees of jaundice, splenomegaly, and absolute reticulocyte count inadequate depending on the degree of anemia. Hydrops fetalis, aplastic crisis and gallstones are other associated clinical signs. CDA II bone marrow is characterized by the presence of more than 10% mature binucleated erythroblasts. Another distinctive feature of CDA II erythrocytes is hypoglycosylation of membrane proteins. The management of CDA II is generally limited to blood transfusion and iron chelation. Splenectomy has proved to reduce the number of transfusions in CDA II patients. However, allogenic hematopoietic stem cell transplant (HSCT) represents the only curative option for this disease. Autologous HSCT of genetically corrected cells will mean a definitive treatment for CDA II, overcoming the limitations of allogeneic HSCT, such as limited availability of HLA-matched donors, infections linked to immunosuppression or development of graft versus host disease. This strategy has been used to treat many inherited hematological diseases, including red blood cell diseases such as β-thalassemia, sickle cell disease or pyruvate kinase deficiency. Therefore, we have addressed a similar strategy to be applied to CDAII patients. Two different lentiviral vectors carrying either wild type or codon optimized versions of SEC23B cDNA (wtSEC23B LV or coSEC23B LV, respectively) under the control of human phosphoglycerate kinase promoter (PGK) have been developed. Taking advantage of a CDA II model, in which SEC23B knock-out was done in human hematopoietic progenitors through gene editing, we have determined the most effective SEC23B LV version and the most suitable multiplicity of infection (MOI) to compensate protein deficiency. SEC23B knock out human hematopoietic progenitors (CD34 + cells; 80% frame shift mutations; SEC23BKO) showed a sharp reduction in SEC23B protein level. Those SEC23BKO hematopoietic progenitors were transduced with both lentiviral vectors at MOIs ranged from 3 to 25. We observed that SEC23B protein reached physiological or even supraphysiological levels. In addition, the reduction in the number of erythroid colony forming units (CFUs) identified in SEC23BKO CD34 + cells, was partially restored in the LV transduced SEC23BKO progenitors. Significantly, we observed a clear correlation between the used MOI and the vector copy number (VCN) in the CFUs derived from transduced SEC23BKO CD34 + cells. Furthermore, SEC23BKO hematopoietic progenitors were subjected to an in vitro erythroid differentiation protocol. A sharp decrease in the cell growth throughout erythroid differentiation was observed in SEC23BKO condition. However, the transduction with any of SEC23B LVs at MOIs above 10 was able to recover cell expansion to values equal to wild type cells. Interestingly, total level of protein glycosylation during erythroid differentiation was enhanced after SEC23B LV transduction. Glycosylation level in wtSEC23B LV transduced SEC23BKO cells was most similar to the level in wild type cells. Then, we transduced peripheral blood-derived hematopoietic progenitors (PB-CD34 + cells) from a CDA II patient with wtSEC23B LV at MOI 25 and differentiated in vitro to erythroid cells. A complete restauration of SEC23B protein expression and a cell growth increase of wtSEC23B transduced CDAII was observed with vector copy numbers of 0.3 after 14 days under erythroid conditions. More importantly, we could find a decrease in the percentage of bi-/multinucleated erythroid cells generated in vitro after wtSEC23B LV transduction. In summary, SEC23B LV compensate the SEC23B deficiency in SEC23BKO and in CDAII hematopoietic progenitor cells, paving the way for gene therapy of autologous hematopoietic stem and progenitor cell as an alternative and feasible treatment for CDA II. Disclosures Bianchi: Agios pharmaceutics: Consultancy, Membership on an entity's Board of Directors or advisory committees. Sanchez: Bloodgenetics: Other: Co-Founder and promoter; UIC: Current Employment. Ramirez: VIVEBiotech: Current Employment. Segovia: Rocket Pharmaceuticals, Inc.: Consultancy, Research Funding. Quintana Bustamante: Rocket Pharmaceuticals, Inc.: Current equity holder in publicly-traded company.
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- 2021
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38. Capillary leak syndrome as a complication of antibody-mediated rejection treatment: a case report
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Luis E. Morales-Buenrostro, Juan C. Ramirez-Sandoval, and Ricardo Varela-Jimenez
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business.industry ,medicine.medical_treatment ,Acute kidney injury ,Case Report ,General Medicine ,030230 surgery ,medicine.disease ,Pancytopenia ,Capillary leak ,03 medical and health sciences ,0302 clinical medicine ,Edema ,Heart failure ,Anesthesia ,Medicine ,030212 general & internal medicine ,Hemodialysis ,Hypoalbuminemia ,medicine.symptom ,business ,Capillary Leak Syndrome - Abstract
We report a case of capillary leak that developed during treatment of antibody-mediated rejection in a kidney transplant recipient. A 53-year-old female transplant recipient experienced an increase in serum creatinine from 1.1 to 1.8 mg/dL. Antibody-mediated rejection was diagnosed by graft biopsy. She was treated with five plasmapheresis sessions (on alternate days with albumin replacement), five doses of immunoglobulin (5 g/dose at 100 mg/kg), a single dose of rituximab (500 mg), and four doses of bortezomib on days 1, 4, 7, and 10 (1.72 mg/dose at 1.3 mg/m2 body surface area). During treatment, edema, slight diarrhea, pancytopenia, hypoalbuminemia, peripheral neuropathy, and postural hypotension were noted. Despite control of liquids, she presented with edema progressing to an increase of more than 10 kg body weight. Prerenal acute graft dysfunction associated with hypotension was diagnosed on day 12, heart failure or other infectious complications being discounted. On day 13, daily hemodialysis was prescribed, and a stable volume status was reached after five hemodialysis sessions. On day 20, the patient recovered diuresis and the edema and diarrhea abated, but she remained on chronic hemodialysis. After excluding other causes of distributive shock, the diagnosis of capillary leak syndrome was based on the presence of hypotension, generalized edema, and hypoalbuminemia in the absence of significant proteinuria. The concomitant presence of diarrhea, peripheral neuropathy, and pancytopenia, suggest a possible causal role for bortezomib. Awareness by clinicians of capillary leak syndrome associated with bortezomib-based treatment of AMR is paramount, despite its rarity.
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- 2018
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39. Efficient Recreation of t(11;22) EWSR1-FLI1+ in Human Stem Cells Using CRISPR/Cas9
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Julio Castaño, Juan C. Cigudosa, Raúl Torres-Ruiz, Marta Martinez-Lage, Sandra Rodriguez-Perales, Clara Bueno, Aida Garcia, Juan C. Ramirez, María C. Martín, Pablo Menendez, Instituto de Salud Carlos III, and European Regional Development Fund (ERDF/FEDER)
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0301 basic medicine ,Oncogene Proteins, Fusion ,Induced Pluripotent Stem Cells ,Sarcoma, Ewing ,Computational biology ,Biology ,Biochemistry ,Translocation, Genetic ,Genome engineering ,MSC ,03 medical and health sciences ,chemistry.chemical_compound ,Genetics ,Humans ,CRISPR ,cancer translocation ,Cas9 ,Induced pluripotent stem cell ,lcsh:QH301-705.5 ,Ribonucleoprotein ,lcsh:R5-920 ,iPSC ,disease model ,Mesenchymal stem cell ,Mesenchymal Stem Cells ,Cell Biology ,human stem cells ,HEK293 Cells ,030104 developmental biology ,lcsh:Biology (General) ,chemistry ,Gene Targeting ,cancer modeling ,CRISPR-Cas Systems ,Stem cell ,genome engineering ,lcsh:Medicine (General) ,Ewing sarcoma ,DNA ,Developmental Biology - Abstract
Efficient methodologies for recreating cancer-associated chromosome translocations are in high demand as tools for investigating how such events initiate cancer. The CRISPR/Cas9 system has been used to reconstruct the genetics of these complex rearrangements at native loci while maintaining the architecture and regulatory elements. However, the CRISPR system remains inefficient in human stem cells. Here, we compared three strategies aimed at enhancing the efficiency of the CRISPR-mediated t(11;22) translocation in human stem cells, including mesenchymal and induced pluripotent stem cells: (1) using end-joining DNA processing factors involved in repair mechanisms, or (2) ssODNs to guide the ligation of the double-strand break ends generated by CRISPR/Cas9; and (3) all-in-one plasmid or ribonucleoprotein complex-based approaches. We report that the generation of targeted t(11;22) is significantly increased by using a combination of ribonucleoprotein complexes and ssODNs. The CRISPR/Cas9-mediated generation of targeted t(11;22) in human stem cells opens up new avenues in modeling Ewing sarcoma. This work was supported by funds from the Spanish National Research and Development Plan, Instituto de Salud Carlos III, and FEDER (PI14/01884 to S.R.-P. and PI12/00425 to J.C.C.). R.T.-R. was supported by an international fellowship from Lady Tata Memorial Trust during 2016–2017. Sí
- Published
- 2017
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40. Cover Image, Volume 7, Issue 7
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Andres Rivera‐Garcia, Liliana Santos‐Ferro, Juan C. Ramirez‐Orejel, Lourdes T. Agredano‐Moreno, Luis F. Jimenez‐Garcia, David Paez‐Esquiliano, Eduardo Andrade‐Esquivel, and Jose A. Cano‐Buendia
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Cover Image ,Food Science - Abstract
The cover image is based on the Original Research The eff ect of neutral electrolyzed water as a disinfectant of eggshells arficially contaminated with Listeria monocytogenes by Andres Rivera‐Garcia et al., DOI: 10.1002/fsn3.1053. [Image: see text]
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- 2019
41. Lentiviral Vectors Come of Age? Hurdles and Challenges in Scaling Up Manufacture
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Juan C. Ramirez
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Risk analysis (engineering) ,Computer science ,Scaling - Published
- 2019
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42. 19th International Conference on Dialysis, Advances in Chronic Kidney Disease 2017, February 1-3, 2017, Las Vegas, NV: Abstracts
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Graziella D'Arrigo, Zhonghua Liu, José F. Pessanha, Xiaoling Ye, Inne Hendrickx, Stephan Thijssen, Zhen Cheng, George A. Kaysen, Schantel Williams, Antoine G. Schneider, Seung Duk Hwang, Druckerei Stückle, Jorge Cerdá, Sandra Wray, Aashish Sharma, Edmundo I. Cabrera-Fischer, Soo Jeong Choi, Silvia De Rosa, Pierre Schläpfer, Michael J. Connor, Sri Lekha Tummalapalli, Tsering Dhondup, Chris Anstey, Jin Kuk Kim, Abdulmecit Yildiz, Vanja Persic, Mariele Gobo-Oliveira, Jay L. Koyner, Sabrina Milan Manani, Yuxin Nie, Marta Proglio, Mark D. Okusa, Claudio Ronco, Michelle M.Y. Wong, Xinghua Chen, Azra Bihorac, Rodolfo Valtuille, Shi-xiang Wang, Hanjie Zhang, Zhen Zhang, Laura M. Rosales, Yanna Dou, Marcee Bonner, Ling Yu, Bo Shen, Huiming Wang, Xiaohong Chen, Peter Kotanko, Fiorella Gastaldon, Abhilash Koratala, Jianzhou Zou, André Luis Balbi, Xuesen Cao, Rinaldo Bellomo, Bo Yeon Kim, Cintia Galli, Daniel Marsh, Anna Meyring-Wösten, Amir Kazory, Rocco Ferrandino, Lili Chan, Ahmed Kayssi, Anja Kruse, Francesco Galli, Viola Van Gorp, Davide Bolignano, Alberto Ortiz, Richard F. Neville, Daniel Bia, Lilia Rizo-Topete, Patrick M. Honore, Rajit K. Basu, Kent Doi, Zoltan H. Endre, Giovanni Tripepi, Anitha Vijayan, Mitchell H. Rosner, Sarah Faubel, Ladan Golestaneh, Nathan W. Levin, Jie Ma, Maggie Han, Kinsuk Chauhan, Yanina Zócalo, D.J. Askenazi, Magdalena Madero, Priti Poojary, Herbert D. Spapen, Yuedong Wang, Rossella Baggetta, Paul Martin, Gianluca Villa, Elisabeth De Waele, Aparna Saha, Ricardo L. Armentano, Adrian Covic, Xiaoqiang Ding, Jinbo Yu, Girish N. Nadkarni, Yalcin Solak, Jouke De Regt, Michel Jadoul, Alessandra Brocca, Hisako Saito, Han Li, Mehmet Kanbay, Débora M. Soares, Yujuan Wang, Juan C Ramirez-Sandoval, Michael Heung, Laura Rosales, L. Gabriela Sánchez-Lozada, Mahmut Ilker Yilmaz, Masayuki Tanemoto, Cristiano Chiappa, Grazia Maria Virzì, Len A. Usvyat, Georges Ouellet, Sun Young Jang, Sara Samoni, Viktoriya Kuntsevich, Jean-Daniel Durovray, Dimitrie Siriopol, Candace Young, Qi Qian, Il Sang Shin, Jili Zhu, Rita Jacobs, Valery Plouhinec, Daniela Ponce, Yu Ishimoto, and Cesar Flores Gama
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Gerontology ,medicine.medical_specialty ,Las vegas ,business.industry ,medicine.medical_treatment ,Hematology ,General Medicine ,medicine.disease ,Nephrology ,Emergency medicine ,medicine ,business ,Dialysis ,Kidney disease - Published
- 2017
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43. Uric Acid, Vascular Stiffness, and Chronic Kidney Disease: Is There a Link?
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Magdalena Madero, L. Gabriela Sánchez-Lozada, and Juan C Ramirez-Sandoval
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musculoskeletal diseases ,medicine.medical_specialty ,Vascular smooth muscle ,Hyperuricemia ,030204 cardiovascular system & hematology ,medicine.disease_cause ,03 medical and health sciences ,chemistry.chemical_compound ,Vascular Stiffness ,0302 clinical medicine ,Internal medicine ,Humans ,Medicine ,030212 general & internal medicine ,Renal Insufficiency, Chronic ,Kidney ,business.industry ,Surrogate endpoint ,Hematology ,General Medicine ,medicine.disease ,Uric Acid ,medicine.anatomical_structure ,Endocrinology ,chemistry ,Nephrology ,Arterial stiffness ,Cardiology ,Uric acid ,business ,Oxidative stress ,Kidney disease - Abstract
Controversy exists with regard to the causal role of hyperuricemia in chronic kidney disease. Vascular stiffness may be the link that explains the relation between hyperuricemia and kidney disease. Hyperuricemia is associated with a number of effects on the vascular endothelium and vascular smooth muscle cells, including an increase in oxidative stress, production of vasoconstrictors, and changes on the structural properties of the large artery wall. Observational evidence in large epidemiological cross-sectional studies suggests that there is an independent association between uric acid and arterial stiffness. The limited evidence from cohort studies or clinical trials does not support treatment of hyperuricemia to reduce vascular stiffness in order to prevent kidney disease. Nevertheless, vascular stiffness may be a valid, reproducible, and useful surrogate endpoint. At this point there seems to be sufficient evidence to warrant larger clinical trials to determine whether lowering uric acid concentrations would be useful for prevention or treatment of vascular stiffness and, subsequently, of cardiovascular and kidney diseases. Video Journal Club ‘Cappuccino with Claudio Ronco' at http://www.karger.com/?doi=452726.
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- 2017
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44. Bicarbonate Values for Healthy Residents Living in Cities Above 1500 Meters of Altitude: A Theoretical Model and Systematic Review
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Olynka Vega-Vega, Juan C. Ramirez-Sandoval, Michael Wagner, José Gotés-Palazuelos, Juan C Vázquez-García, María Fernanda Castilla-Peón, Ricardo Correa-Rotter, Rodolfo Rincón-Pedrero, and Carlos A Merelo-Arias
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Adult ,Male ,0301 basic medicine ,Gerontology ,Physiology ,Acclimatization ,Bicarbonate ,030204 cardiovascular system & hematology ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Altitude ,Reference Values ,Humans ,Cities ,Sea level ,Acid-Base Equilibrium ,Public Health, Environmental and Occupational Health ,General Medicine ,Models, Theoretical ,Effects of high altitude on humans ,Healthy Volunteers ,Bicarbonates ,030104 developmental biology ,Geography ,chemistry ,Healthy individuals ,Female ,Demography - Abstract
Ramirez-Sandoval, Juan C., Maria F. Castilla-Peón, José Gotés-Palazuelos, Juan C. Vázquez-García, Michael P. Wagner, Carlos A. Merelo-Arias, Olynka Vega-Vega, Rodolfo Rincón-Pedrero, and Ricardo Correa-Rotter. Bicarbonate values for healthy residents living in cities above 1500 m of altitude: a theoretical model and systematic review. High Alt Med Biol. 17:85-92, 2016.-Plasma bicarbonate (HCO3(-)) concentration is the main value used to assess the metabolic component of the acid-base status. There is limited information regarding plasma HCO3(-) values adjusted for altitude for people living in cities at high altitude defined as 1500 m (4921 ft) or more above sea level. Our aim was to estimate the plasma HCO3(-) concentration in residents of cities at these altitudes using a theoretical model and compare these values with HCO3(-) values found on a systematic review, and with those venous CO2 values obtained in a sample of 633 healthy individuals living at an altitude of 2240 m (7350 ft). We calculated the PCO2 using linear regression models and calculated plasma HCO3(-) according to the Henderson-Hasselbalch equation. Results show that HCO3(-) concentration falls as the altitude of the cities increase. For each 1000 m of altitude above sea level, HCO3(-) decreases to 0.55 and 1.5 mEq/L in subjects living at sea level with acute exposure to altitude and in subjects acclimatized to altitude, respectively. Estimated HCO3(-) values from the theoretical model were not different to HCO3(-) values found in publications of a systematic review or with venous total CO2 measurements in our sample. Altitude has to be taken into consideration in the calculation of HCO3(-) concentrations in cities above 1500 m to avoid an overdiagnosis of acid-base disorders in a given individual.
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- 2016
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45. Precision immunology for discovery and development of the Precision Vaccines Program (PVP)-037 small molecule series: imidazopyrimidine adjuvants identified via age-specific human in vitro modeling
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Dheeraj Soni, Francesco Borriello, David A Scott, Al Ozonoff, Spencer Brightman, Jennifer Smith, Caroline Shamu, Juan C Ramirez, Lindsey Robert Baden, Wing Ki Cheng, Simon Daniel van Haren, Matthew Pettengill, David J Dowling, and Ofer Levy
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Immunology ,Immunology and Allergy - Abstract
Infection is a significant cause of mortality and immunization is the most promising biomedical intervention to reduce this burden. However, multiple booster doses are often required to protect those with distinct immunity such as the young, elders, and immunocompromised individuals. Adjuvants are molecules that potentiate vaccine responses. There is a need for a larger toolbox of adjuvants, since Alum is the only adjuvant currently incorporated into licensed vaccines in the pediatric setting. We utilized a unique in vitro approach to discover new adjuvants, screening a ~10k small molecule library via a no-wash 384-well quantitative TNF immunoassay in peripheral blood mononuclear cells (PBMCs) from 3 adult healthy human donors. Preliminary hits were based on induced TNF production in at least two of the three donors screened. We identified a novel imidazopyrimidine (IMP) scaffold named PVP-037 which demonstrated efficacy, potency, and adjuvanticity. PVP-037 demonstrated broad age-independent immune-stimulatory ability in human PBMCs and dendritic cells, including key Th-polarizing cytokines such as IL-12, and significant enhancement murine humoral responses to recombinant hemagglutinin (rHA) proteins in the quadrivalent influenza. PVP-037 further demonstrated limited activity in several common cell lines (THP-1) and murine/porcine primary leukocytes. Structure activity relationship (SAR) studies identified the analog PVP-144-3 with greater in vitro efficacy across species (porcine, non-human primates) and murine in vivo adjuvanticity. Overall, we discovered an IMP adjuvant via high throughput screening of human mononuclear cells in vitro which correlated with enhanced influenza immunization in mice.
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- 2020
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46. Cartas científicas
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Mario Beretta, Fernando Mut, Miguel Kapitan, Andrea López, and Juan C. Ramirez
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General Medicine - Published
- 2018
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47. Independence screening for high dimensional nonlinear additive ODE models with applications to dynamic gene regulatory networks
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Shuang Wu, Hulin Wu, Juan C. Ramirez Idarraga, Yichao Wu, and Hongqi Xue
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Statistics and Probability ,Clustering high-dimensional data ,Epidemiology ,Computer science ,0206 medical engineering ,Gene regulatory network ,Feature selection ,02 engineering and technology ,01 natural sciences ,Article ,010104 statistics & probability ,Applied mathematics ,Humans ,Computer Simulation ,Gene Regulatory Networks ,0101 mathematics ,Models, Statistical ,Quantitative Biology::Molecular Networks ,Ode ,Nonlinear system ,Nonlinear Dynamics ,Ordinary differential equation ,020602 bioinformatics ,Smoothing ,Algorithms ,Mathematics ,Curse of dimensionality - Abstract
Mechanism-driven low-dimensional ordinary differential equation (ODE) models are often used to model viral dynamics at cellular levels and epidemics of infectious diseases. However, low-dimensional mechanism-based ODE models are limited for modeling infectious diseases at molecular levels such as transcriptomic or proteomic levels, which is critical to understand pathogenesis of diseases. Although linear ODE models have been proposed for gene regulatory networks (GRNs), nonlinear regulations are common in GRNs. The reconstruction of large-scale nonlinear networks from time-course gene expression data remains an unresolved issue. Here, we use high-dimensional nonlinear additive ODEs to model GRNs and propose a 4-step procedure to efficiently perform variable selection for nonlinear ODEs. To tackle the challenge of high dimensionality, we couple the 2-stage smoothing-based estimation method for ODEs and a nonlinear independence screening method to perform variable selection for the nonlinear ODE models. We have shown that our method possesses the sure screening property and it can handle problems with non-polynomial dimensionality. Numerical performance of the proposed method is illustrated with simulated data and a real data example for identifying the dynamic GRN of Saccharomyces cerevisiae.
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- 2018
48. Treatment of Hyperuricemia in Chronic Kidney Disease
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Juan C, Ramirez-Sandoval and Magdalena, Madero
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Febuxostat ,Allopurinol ,Weight Loss ,Disease Progression ,Humans ,Hyperuricemia ,Renal Insufficiency, Chronic ,Exercise ,Life Style ,Diet ,Gout Suppressants ,Randomized Controlled Trials as Topic - Abstract
Hyperuricemia may be a major contributor to the development or progression of chronic kidney disease (CKD). Although there is no clear cutoff uric acid (UA) value associated to the risk for kidney damage, it appears to be an increased risk as UA rises. Lifestyle interventions such as exercise, weight reduction, low consumption of purine-rich meat, or avoiding high fructose intake are recommended for all hyperuricemic patients. Lowering urate drugs such as allopurinol or febuxostat may be an option as a renoprotective agent; yet, randomized clinical trials evaluating the safety and efficacy of these drugs are limited to a small number of single-center studies. Several ongoing clinical trials aim to evaluate the safety and efficacy of these drugs. As of today, there is insufficient evidence to recommend the widespread use of UA-lowering therapy to prevent or slow down the progression of CKD. The purpose of this review is to summarize the evidence and future perspectives about the treatment of hyperuricemia in the prevention and progression of CKD.
- Published
- 2018
49. The miR-17-92 cluster counteracts quiescence and chemoresistance in a distinct subpopulation of pancreatic cancer stem cells
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Irene Miranda-Lorenzo, Michele Cioffi, Sara Trabulo, Jorge Dorado, Alexandra Aicher, Juan C. Ramirez, Stephan A. Hahn, Manuel Hidalgo, Catarina R. Vieira, Yolanda Sanchez-Ripoll, Enza Lonardo, Bruno Sainz, Christopher Heeschen, European Research Council, European Commission, Ministerio de Economía y Competitividad (España), Instituto de Salud Carlos III, and Fundación La Caixa
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TUMORIGENICITY ,Bioinformatics ,Deoxycytidine ,Epigenesis, Genetic ,Metastasis ,PATHWAY ,Transcriptome ,Mice ,0302 clinical medicine ,Cell Self Renewal ,DOWNSTREAM TARGET ,0303 health sciences ,PROLIFERATION ,Gastroenterology ,TBX3 ,SOLID TUMORS ,Activins ,3. Good health ,Gene Expression Regulation, Neoplastic ,Cell Transformation, Neoplastic ,Gene Knockdown Techniques ,030220 oncology & carcinogenesis ,Neoplastic Stem Cells ,Female ,RNA, Long Noncoding ,Stem cell ,Carcinoma, Pancreatic Ductal ,Signal Transduction ,Cyclin-Dependent Kinase Inhibitor p21 ,EXPRESSION ,Antimetabolites, Antineoplastic ,Nodal Protein ,Down-Regulation ,Mice, Nude ,Biology ,Transforming Growth Factor beta1 ,03 medical and health sciences ,Downregulation and upregulation ,Cancer stem cell ,Pancreatic cancer ,microRNA ,medicine ,Animals ,Humans ,Epigenetics ,Cyclin-Dependent Kinase Inhibitor p57 ,030304 developmental biology ,IDENTIFICATION ,Correction ,Cell Cycle Checkpoints ,medicine.disease ,Gemcitabine ,MICRORNA CLUSTER ,Pancreatic Neoplasms ,MicroRNAs ,SELF-RENEWAL ,Drug Resistance, Neoplasm ,Cancer research ,T-Box Domain Proteins - Abstract
Objective Cancer stem cells (CSCs) represent the root of many solid cancers including pancreatic ductal adenocarcinoma, are highly chemoresistant and represent the cellular source for disease relapse. However the mechanisms involved in these processes still need to be fully elucidated. Understanding the mechanisms implicated in chemoresistance and metastasis of pancreatic cancer is critical to improving patient outcomes. Design Micro-RNA (miRNA) expression analyses were performed to identify functionally defining epigenetic signatures in pancreatic CSC-enriched sphere-derived cells and gemcitabine-resistant pancreatic CSCs. Results We found the miR-17-92 cluster to be downregulated in chemoresistant CSCs versus non-CSCs and demonstrate its crucial relevance for CSC biology. In particular, overexpression of miR-17-92 reduced CSC self-renewal capacity, in vivo tumourigenicity and chemoresistance by targeting multiple NODAL/ACTIVIN/TGF-beta 1 signalling cascade members as well as directly inhibiting the downstream targets p21, p57 and TBX3. Overexpression of miR-17-92 translated into increased CSC proliferation and their eventual exhaustion via downregulation of p21 and p57. Finally, the translational impact of our findings could be confirmed in preclinical models for pancreatic cancer. Conclusions Our findings therefore identify the miR-17-92 cluster as a functionally determining family of miRNAs in CSCs, and highlight the putative potential of developing modulators of this cluster to overcome drug resistance in pancreatic CSCs. CH: ERC Advanced Investigator Grant (Pa-CSC 233460), European Community's Seventh Framework Programme (FP7/2007-2013) under grant agreement No 256974 (EPC-TM-NET) and No 602783 (CAM-PaC), the Subdireccion General de Evaluacion y Fomento de la Investigacion, Fondo de Investigacion Sanitaria (PS09/02129 \& PI12/02643), and the Programa Nacional de Internacionalizacion de la I+D, Subprogramma: FCCI 2009 (PLE2009-0105; Ministerio de Economia y Competitividad, Spain). MC: La Caixa Predoctoral Fellowship. Sí
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- 2015
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50. The Use of Innovative Tools to Reproduce Human Cancer Translocations: Lessons from the CRISPR/Cas System
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Juan C. Ramirez, Sandra Rodriguez-Perales, and Raul M. Torres
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Marketing ,Pharmacology ,Genetics ,Organizational Behavior and Human Resource Management ,Strategy and Management ,Drug Discovery ,Pharmaceutical Science ,CRISPR ,Biology ,Human cancer - Published
- 2015
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