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1.
J Intensive Care Med ; : 8850666241286484, 2024 Sep 19.
Artículo en Inglés | MEDLINE | ID: mdl-39295468

RESUMEN

The systematic review and meta-analysis performed by Kang et al about the effect of extended prone positioning in intubated COVID-19 patients with ARDS presents valuable findings on the effectiveness and safety of extended prone positioning, but also raises several concerns which require clarifications. The inclusion of observational studies without any control group, the use of crude rather than adjusted estimates in key variables from observational studies, an error in data extraction from randomized clinical trials, and the employment of odds ratios rather than risk ratios, may mislead interpretations of the aforementioned intervention.

2.
Ann Hepatol ; 29(4): 101511, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38710474

RESUMEN

INTRODUCTION AND OBJECTIVES: Patients with metabolic dysfunction-associated steatotic liver disease (MASLD) are at an increased cardiovascular risk. On the contrary, non-alcoholic fatty liver disease (NAFLD) is highly prevalent in patients with coronary heart disease (CHD). However, it is not known whether patients with significant CHD show a higher frequency of liver fibrosis. This study aimed to determine the frequency of MASLD and liver fibrosis in patients with CHD and to assess whether coronary stenosis is significantly associated with MASLD and fibrosis. PATIENTS AND METHODS: This observational and analytical study included adult patients without any known liver disease who underwent coronary angiography for suspected coronary artery disease (Jul 2021-Jul 2022). The presence of significant CHD (> 50% stenosis of at least one coronary artery) was determined. Liver elastography (FibroScan®) was performed up to 6 months after the coronary angiographic study to determine liver fibrosis, a measurement of liver stiffness (> 6.5 Kpa). Fisher's test, Mann-Whitney U test, and logistic regression models were used (p < 0.05). RESULTS: The study included 113 patients (76% men, average age: 63 years [standard deviation: 9.9]), of which 72% presented with significant CHD. The prevalence rate of MASLD was 52%. Liver fibrosis was present in 12% of the patients and all patients in the significant CHD group (p = 0.007). An increase in the number of vessels with significant CHD increased the probability of liver fibrosis (odds ratio, 1.79; 95% confidence interval, 1.06-3.04; p = 0.029). CONCLUSIONS: MASLD is highly prevalent in patients with significant CHD but without known liver damage. These data suggest that MASLD and liver fibrosis should be investigated in patients with CHD. The presence of confounding variables, especially the presence of type 2 diabetes mellitus, should be evaluated in further studies.


Asunto(s)
Angiografía Coronaria , Enfermedad de la Arteria Coronaria , Cirrosis Hepática , Humanos , Masculino , Persona de Mediana Edad , Femenino , Cirrosis Hepática/epidemiología , Cirrosis Hepática/diagnóstico por imagen , Cirrosis Hepática/complicaciones , Enfermedad de la Arteria Coronaria/diagnóstico por imagen , Enfermedad de la Arteria Coronaria/epidemiología , Factores de Riesgo , Anciano , Prevalencia , Enfermedad del Hígado Graso no Alcohólico/epidemiología , Enfermedad del Hígado Graso no Alcohólico/complicaciones , Enfermedad del Hígado Graso no Alcohólico/diagnóstico por imagen , Diagnóstico por Imagen de Elasticidad , Hígado Graso/diagnóstico por imagen , Hígado Graso/epidemiología , Hígado Graso/complicaciones , Estenosis Coronaria/diagnóstico por imagen , Estenosis Coronaria/epidemiología
3.
Crit Care ; 27(1): 457, 2023 11 24.
Artículo en Inglés | MEDLINE | ID: mdl-38001485

RESUMEN

BACKGROUND: In the acute distress respiratory syndrome (ARDS), specific lung regions can be exposed to excessive strain due to heterogeneous disease, gravity-dependent lung collapse and injurious mechanical ventilation. Computed tomography (CT) is the gold standard for regional strain assessment. An alternative tool could be the electrical impedance tomography (EIT). We aimed to determine whether EIT-based methods can predict the dynamic relative regional strain (DRRS) between two levels of end-expiratory pressure (PEEP) in gravity-non-dependent and dependent lung regions. METHODS: Fourteen ARDS patients underwent CT and EIT acquisitions (at end-inspiratory and end-expiratory) at two levels of PEEP: a low-PEEP based on ARDS-net strategy and a high-PEEP titrated according to EIT. Three EIT-based methods for DRRS were compared to relative CT-based strain: (1) the change of the ratio between EIT ventilation and end-expiratory lung impedance in arbitrary units ([ΔZAU low-PEEP/EELIAU low-PEEP]/[ΔZAU high-PEEP/EELIAU high-PEEP]), (2) the change of ΔZ/EELI ratio calibrated to mL ([ΔZml low-PEEP/EELIml low-PEEP]/[ΔZml high-PEEP/EELIml high-PEEP]) using CT data, and (3) the relative change of ∆ZAU (∆ZAU low-PEEP/∆ZAU high-PEEP). We performed linear regressions analysis and calculated bias and limits of agreement to assess the performance of DRRS by EIT in comparison with CT. RESULTS: The DRRS assessed by (ΔZml low-PEEP/EELIml low-PEEP)/(ΔZml high-PEEP/EELIml high-PEEP) and ∆ZAU low-PEEP/∆ZAU high-PEEP showed good relationship and agreement with the CT method (R2 of 0.9050 and 0.8679, respectively, in non-dependent region; R2 of 0.8373 and 0.6588, respectively, in dependent region; biases ranging from - 0.11 to 0.51 and limits of agreement ranging from - 0.73 to 1.16 for both methods and lung regions). Conversely, DRRS based on EELIAU ([ΔZAU low-PEEP/EELIAU low-PEEP]/[ΔZAU high-PEEP/EELIAU high-PEEP]) exhibited a weak negative relationship and poor agreement with the CT method for both non-dependent and dependent regions (R2 ~ 0.3; bias of 3.11 and 2.08, and limits of agreement of - 2.13 to 8.34 and from - 1.49 to 5.64, respectively). CONCLUSION: Changes in DRRS during a PEEP trial in ARDS patients could be monitored using EIT, based on changes in ΔZmL/EELIml and ∆ZAU. The relative change ∆ZAU offers the advantage of not requiring CT data for calibration.


Asunto(s)
Respiración con Presión Positiva , Síndrome de Dificultad Respiratoria , Humanos , Impedancia Eléctrica , Respiración con Presión Positiva/métodos , Pulmón/diagnóstico por imagen , Tomografía Computarizada por Rayos X/métodos , Síndrome de Dificultad Respiratoria/diagnóstico por imagen , Tomografía/métodos
4.
Am J Respir Crit Care Med ; 204(1): 34-43, 2021 07 01.
Artículo en Inglés | MEDLINE | ID: mdl-33823118

RESUMEN

Rationale: The role of and needs for extracorporeal membrane oxygenation (ECMO) at a population level during the coronavirus disease (COVID-19) pandemic have not been completely established. Objectives: To identify the cumulative incidence of ECMO use in the first pandemic wave and to describe the Nationwide Chilean cohort of ECMO-supported patients with COVID-19. Methods: We conducted a population-based study from March 3 to August 31, 2020, using linked data from national agencies. The cumulative incidence of ECMO use and mortality risk of ECMO-supported patients were calculated and age standardized. In addition, a retrospective cohort analysis was performed. Outcomes were 90-day mortality after ECMO initiation, ECMO-associated complications, and hospital length of stay. Cox regression models were used to explore risk factors for mortality in a time-to-event analysis. Measurements and Main Results: Ninety-four patients with COVID-19 were supported with ECMO (0.42 per population of 100,000, 14.89 per 100,000 positive cases, and 1.2% of intubated patients with COVID-19); 85 were included in the cohort analysis, and the median age was 48 (interquartile range [IQR], 41-55) years, 83.5% were men, and 42.4% had obesity. The median number of pre-ECMO intubation days was 4 (IQR, 2-7), the median PaO2/FiO2 ratio was 86.8 (IQR, 64-99) mm Hg, 91.8% of patients were prone positioned, and 14 patients had refractory respiratory acidosis. Main complications were infections (70.6%), bleeding (38.8%), and thromboembolism (22.4%); 52 patients were discharged home, and 33 died. The hospital length of stay was a median of 50 (IQR, 24-69) days. Lower respiratory system compliance and higher driving pressure before ECMO initiation were associated with increased mortality. A duration of pre-ECMO intubation ≥10 days was not associated with mortality. Conclusions: Documenting nationwide ECMO needs may help in planning ECMO provision for future COVID-19 pandemic waves. The 90-day mortality of the Chilean cohort of ECMO-supported patients with COVID-19 (38.8%) is comparable to that of previous reports.


Asunto(s)
COVID-19/terapia , Oxigenación por Membrana Extracorpórea/estadística & datos numéricos , Síndrome de Dificultad Respiratoria/terapia , Adulto , Anciano , COVID-19/complicaciones , COVID-19/diagnóstico , COVID-19/epidemiología , Chile/epidemiología , Femenino , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Evaluación de Necesidades , Síndrome de Dificultad Respiratoria/diagnóstico , Síndrome de Dificultad Respiratoria/epidemiología , Síndrome de Dificultad Respiratoria/virología , Estudios Retrospectivos , Índice de Severidad de la Enfermedad , Resultado del Tratamiento
5.
Acta Anaesthesiol Scand ; 65(2): 228-235, 2021 02.
Artículo en Inglés | MEDLINE | ID: mdl-33037607

RESUMEN

RATIONALE: Cyclic strain may be a determinant of ventilator-induced lung injury. The standard for strain assessment is the computed tomography (CT), which does not allow continuous monitoring and exposes to radiation. Electrical impedance tomography (EIT) is able to monitor changes in regional lung ventilation. In addition, there is a correlation between mechanical deformation of materials and detectable changes in its electrical impedance, making EIT a potential surrogate for cyclic lung strain measured by CT (StrainCT ). OBJECTIVES: To compare the global StrainCT with the change in electrical impedance (ΔZ). METHODS: Acute respiratory distress syndrome patients under mechanical ventilation (VT 6 mL/kg ideal body weight with positive end-expiratory pressure 5 [PEEP 5] and best PEEP according to EIT) underwent whole-lung CT at end-inspiration and end-expiration. Biomechanical analysis was used to construct 3D maps and determine StrainCT at different levels of PEEP. CT and EIT acquisitions were performed simultaneously. Multilevel analysis was employed to determine the causal association between StrainCT and ΔZ. Linear regression models were used to predict the change in lung StrainCT between different PEEP levels based on the change in ΔZ. MAIN RESULTS: StrainCT was positively and independently associated with ΔZ at global level (P < .01). Furthermore, the change in StrainCT (between PEEP 5 and Best PEEP) was accurately predicted by the change in ΔZ (R2 0.855, P < .001 at global level) with a high agreement between predicted and measured StrainCT . CONCLUSIONS: The change in electrical impedance may provide a noninvasive assessment of global cyclic strain, without radiation at bedside.


Asunto(s)
Pulmón , Tomografía , Impedancia Eléctrica , Humanos , Pulmón/diagnóstico por imagen , Respiración con Presión Positiva , Tomografía Computarizada por Rayos X
6.
Int J Clin Pract ; 75(12): e14919, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-34564929

RESUMEN

AIMS OF THIS STUDY: To describe the Latin American population affected by COVID-19, and to determine relevant risk factors for in-hospital mortality. METHODS: We prospectively registered relevant clinical, laboratory, and radiological data of adult patients with COVID-19, admitted within the first 100 days of the pandemic from a single teaching hospital in Santiago, Chile. The primary outcome was in-hospital mortality. Secondary outcomes included the need for respiratory support and pharmacological treatment, among others. We combined the chronic disease burden and the severity of illness at admission with predefined clinically relevant risk factors. Cox regression models were used to identify risk factors for in-hospital mortality. RESULTS: We enrolled 395 adult patients, their median age was 61 years; 62.8% of patients were male and 40.1% had a Modified Charlson Comorbidity Index (MCCI) ≥5. Their median Sequential Organ Failure Assessment (SOFA) score was 3; 34.9% used a high-flow nasal cannula and 17.5% required invasive mechanical ventilation. The in-hospital mortality rate was 14.7%. In the multivariate analysis, were significant risk factors for in-hospital mortality: MCCI ≥5 (HR 4.39, P < .001), PaO2 /FiO2 ratio ≤200 (HR 1.92, P = .037), and advanced chronic respiratory disease (HR 3.24, P = .001); pre-specified combinations of these risk factors in four categories was associated with the outcome in a graded manner. CONCLUSIONS AND CLINICAL IMPLICATIONS: The relationship between multiple prognostic factors has been scarcely reported in Latin American patients with COVID-19. By combining different clinically relevant risk factors, we can identify COVID-19 patients with high-, medium- and low-risk of in-hospital mortality.


Asunto(s)
COVID-19 , Adulto , Chile/epidemiología , Mortalidad Hospitalaria , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , SARS-CoV-2
7.
Malar J ; 18(1): 65, 2019 Mar 08.
Artículo en Inglés | MEDLINE | ID: mdl-30849984

RESUMEN

BACKGROUND: Optimal adoption of the malaria transmission-blocking strategy is currently limited by lack of safe and efficacious drugs. This has sparked the exploration of different sources of drugs in search of transmission-blocking agents. While plant species have been extensively investigated in search of malaria chemotherapeutic agents, comparatively less effort has been channelled towards exploring them in search of transmission-blocking drugs. Artemisia afra (Asteraceae), a prominent feature of South African folk medicine, is used for the treatment of a number of diseases, including malaria. In search of transmission-blocking compounds aimed against Plasmodium parasites, the current study endeavoured to isolate and identify gametocytocidal compounds from A. afra. METHODS: A bioassay-guided isolation approach was adopted wherein a combination of solvent-solvent partitioning and gravity column chromatography was used. Collected fractions were continuously screened in vitro for their ability to inhibit the viability of primarily late-stage gametocytes of Plasmodium falciparum (NF54 strain), using a parasite lactate dehydrogenase assay. Chemical structures of isolated compounds were elucidated using UPLC-MS/MS and NMR data analysis. RESULTS: Two guaianolide sesquiterpene lactones, 1α,4α-dihydroxybishopsolicepolide and yomogiartemin, were isolated and shown to be active (IC50 < 10 µg/ml; ~ 10 µM) against both gametocytes and intra-erythrocytic asexual P. falciparum parasites. Interestingly, 1α,4α-dihydroxybishopsolicepolide was significantly more potent against late-stage gametocytes than to early-stage gametocytes and intra-erythrocytic asexual P. falciparum parasites. Additionally, both isolated compounds were not overly cytotoxic against HepG2 cells in vitro. CONCLUSION: This study provides the first instance of isolated compounds from A. afra against P. falciparum gametocytes as a starting point for further investigations on more plant species in search of transmission-blocking compounds.


Asunto(s)
Antiprotozoarios/farmacología , Artemisia/química , Extractos Vegetales/farmacología , Plasmodium falciparum/efectos de los fármacos , Antiprotozoarios/química , Antiprotozoarios/aislamiento & purificación , Supervivencia Celular/efectos de los fármacos , Cromatografía Liquida , Concentración 50 Inhibidora , Espectroscopía de Resonancia Magnética , Pruebas de Sensibilidad Parasitaria , Extractos Vegetales/aislamiento & purificación , Espectrometría de Masas en Tándem
8.
J Thromb Thrombolysis ; 47(1): 166, 2019 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-30478721

RESUMEN

Unfortunately the author list in the original article is incomplete. The correct list of contributing authors is given in this Correction.

9.
Am J Hum Biol ; 30(1)2018 01.
Artículo en Inglés | MEDLINE | ID: mdl-28884861

RESUMEN

OBJECTIVES: Abdominal fat may be a better predictor than body mass index (BMI) for risk of metabolically-related diseases, such as diabetes, cardiovascular disease, and some cancers. We sought to validate the percent fat reported on dual energy X-ray absorptiometry (DXA) regional spine scans (spine fat fraction, SFF) against abdominal fat obtained from total body scans using the iDXA machine (General Electric, Madison, WI), as previously done on the Prodigy model. METHODS: Total body scans and regional spine scans were completed on the same day (N = 50). In alignment with the Prodigy-based study, the following regions of interest (ROI) were assessed from total body scans and compared to the SFF from regional spine scans: total abdominal fat at (1) lumbar vertebrae L2-L4 and (2) L2-Iliac Crest (L2-IC); (3) total trunk fat; and (4) visceral fat in the android region. Separate linear regression models were used to predict each total body scan ROI from SFF; models were validated by bootstrapping. RESULTS: The sample was 84% female, a mean age of 38.5 ± 17.4 years, and mean BMI of 23.0 ± 3.8 kg/m2 . The SFF, adjusted for BMI, predicted L2-L4 and L2-IC total abdominal fat (%; Adj. R2 : 0.90) and total trunk fat (%; Adj. R2 : 0.88) well; visceral fat (%) adjusted R2 was 0.83. Linear regression models adjusted for additional participant characteristics resulted in similar adjusted R2 values. CONCLUSIONS: This replication of the strong correlation between SFF and abdominal fat measures on the iDXA in a new population confirms the previous Prodigy model findings and improves generalizability.


Asunto(s)
Grasa Abdominal/diagnóstico por imagen , Absorciometría de Fotón/métodos , Columna Vertebral/diagnóstico por imagen , Imagen de Cuerpo Entero/veterinaria , Adulto , Arizona , Femenino , Humanos , Grasa Intraabdominal/diagnóstico por imagen , Masculino , Persona de Mediana Edad , Reproducibilidad de los Resultados , Adulto Joven
10.
Phys Rev Lett ; 118(14): 141101, 2017 Apr 07.
Artículo en Inglés | MEDLINE | ID: mdl-28430501

RESUMEN

Electromagnetic fields which solve the vacuum Maxwell equations in one spacetime are well known to also be solutions in all spacetimes with conformally related metrics. This provides a sense in which electromagnetism alone cannot be used to measure certain aspects of geometry. We show that there is actually much more which cannot be so measured; relatively little of a spacetime's geometry is in fact imprinted in any particular electromagnetic field. This is demonstrated by finding a much larger class of metric transformations-involving five free functions-which preserve Maxwell solutions both in vacuum, without local currents, and also for the force-free electrodynamics associated with a tenuous plasma. One consequence of this is that many of the exact force-free fields which have previously been found around Schwarzschild and Kerr black holes are also solutions in appropriately identified flat backgrounds. As a more direct application, we use our metric transformations to write down a large class of electromagnetic waves which remain unchanged by a large class of gravitational waves propagating "in the same direction."

12.
Nature ; 471(7337): 216-9, 2011 Mar 10.
Artículo en Inglés | MEDLINE | ID: mdl-21390129

RESUMEN

Humans differ from other animals in many aspects of anatomy, physiology, and behaviour; however, the genotypic basis of most human-specific traits remains unknown. Recent whole-genome comparisons have made it possible to identify genes with elevated rates of amino acid change or divergent expression in humans, and non-coding sequences with accelerated base pair changes. Regulatory alterations may be particularly likely to produce phenotypic effects while preserving viability, and are known to underlie interesting evolutionary differences in other species. Here we identify molecular events particularly likely to produce significant regulatory changes in humans: complete deletion of sequences otherwise highly conserved between chimpanzees and other mammals. We confirm 510 such deletions in humans, which fall almost exclusively in non-coding regions and are enriched near genes involved in steroid hormone signalling and neural function. One deletion removes a sensory vibrissae and penile spine enhancer from the human androgen receptor (AR) gene, a molecular change correlated with anatomical loss of androgen-dependent sensory vibrissae and penile spines in the human lineage. Another deletion removes a forebrain subventricular zone enhancer near the tumour suppressor gene growth arrest and DNA-damage-inducible, gamma (GADD45G), a loss correlated with expansion of specific brain regions in humans. Deletions of tissue-specific enhancers may thus accompany both loss and gain traits in the human lineage, and provide specific examples of the kinds of regulatory alterations and inactivation events long proposed to have an important role in human evolutionary divergence.


Asunto(s)
Evolución Biológica , ADN/genética , Genoma Humano/genética , Características Humanas , Secuencias Reguladoras de Ácidos Nucleicos/genética , Eliminación de Secuencia/genética , Animales , Encéfalo/anatomía & histología , Encéfalo/metabolismo , Cromosomas de los Mamíferos/genética , Secuencia Conservada/genética , ADN Intergénico/genética , Elementos de Facilitación Genéticos/genética , Evolución Molecular , Genes Supresores de Tumor , Humanos , Masculino , Ratones , Especificidad de Órganos , Pan troglodytes/genética , Pene/anatomía & histología , Pene/metabolismo , Especificidad de la Especie , Transgenes/genética
13.
Ann Oncol ; 27(11): 2039-2045, 2016 11.
Artículo en Inglés | MEDLINE | ID: mdl-27793849

RESUMEN

BACKGROUND: Risk models of chemotherapy-induced (CIN) and febrile neutropenia (FN) have to date focused on determinants measured at the start of chemotherapy. We extended this static approach with a dynamic approach of CIN/FN risk modeling at the start of each cycle. DESIGN: We applied predictive modeling using multivariate logistic regression to identify determinants of CIN/FN episodes and related hospitalizations and chemotherapy disturbances (CIN/FN consequences) in analyses at the patient ('ever' during the whole period of chemotherapy) and cycle-level (during a given chemotherapy cycle). Statistical dependence of cycle data being 'nested' under patients was managed using generalized estimation equations. Predictive performance of each model was evaluated using bootstrapped c concordance statistics. RESULTS: Static patient-level risk models of 'ever' experiencing CIN/FN adverse events and consequences during a planned chemotherapy regimen included predictors related to history, risk factors, and prophylaxis initiation and intensity. Dynamic cycle-level risk models of experiencing CIN/FN adverse events and consequences in an upcoming cycle included predictors related to history, risk factors, and prophylaxis initiation and intensity; as well as prophylaxis duration, CIN/FN in prior cycle, and treatment center characteristics. CONCLUSIONS: These 'real-world evidence' models provide clinicians with the ability to anticipate CIN/FN adverse events and their consequences at the start of a chemotherapy line (static models); and, innovatively, to assess risk of CIN/FN adverse events and their consequences at the start of each cycle (dynamic models). This enables individualized patient treatment and is consistent with the EORTC recommendation to re-appraise CIN/FN risk at the start of each cycle. Prophylaxis intensity (under-, correctly-, or over-prophylacted relative to current EORTC guidelines) is a major determinant. Under-prophylaxis is clinically unsafe. Over-prophylaxis of patients administered chemotherapy with intermediate or low myelotoxicity levels may be beneficial, both in patients with and without risk factors, and must be validated in future studies.


Asunto(s)
Biosimilares Farmacéuticos/efectos adversos , Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos/patología , Neutropenia Febril/patología , Filgrastim/administración & dosificación , Adulto , Anciano , Biosimilares Farmacéuticos/administración & dosificación , Neutropenia Febril/inducido químicamente , Femenino , Filgrastim/efectos adversos , Factor Estimulante de Colonias de Granulocitos/metabolismo , Humanos , Modelos Logísticos , Masculino , Persona de Mediana Edad , Modelos Estadísticos , Factores de Riesgo
14.
Allergy ; 71(5): 593-610, 2016 05.
Artículo en Inglés | MEDLINE | ID: mdl-26644231

RESUMEN

We reviewed 24 'real-life' effectiveness studies of omalizumab in the treatment of severe allergic asthma that included 4117 unique patients from 32 countries with significant heterogeneity in patients, clinicians and settings. The evidence underscores the short- and long-term benefit of anti-IgE therapy in terms of the following: improving lung function; achieving asthma control and reducing symptomatology, severe exacerbations and associated work/school days lost; reducing healthcare resource utilizations, in particular hospitalizations, hospital lengths of stay and accident specialist or emergency department visits; reducing or discontinuing other asthma medications; and improving quality of life - thus confirming, complementing and extending evidence from randomized trials. Thus, omalizumab therapy is associated with signal improvements across the full objective and subjective burden of illness chain of severe allergic asthma. Benefits of omalizumab may extend up to 2-4 years, and the majority of omalizumab-treated patients may benefit for many years. Omalizumab has positive short- and long-term safety profiles similar to what is known from randomized clinical trials. Initiated patients should be monitored for treatment response at 16 weeks. Those showing positive response at that time are highly likely to show sustained treatment response and benefit in terms of clinical, quality of life and health resource utilization outcomes.


Asunto(s)
Antiasmáticos/uso terapéutico , Asma/tratamiento farmacológico , Omalizumab/uso terapéutico , Adulto , Antiasmáticos/administración & dosificación , Antiasmáticos/efectos adversos , Asma/diagnóstico , Asma/inmunología , Estudios Clínicos como Asunto , Recursos en Salud , Humanos , Inmunoglobulina E/inmunología , Omalizumab/administración & dosificación , Omalizumab/efectos adversos , Aceptación de la Atención de Salud , Proyectos de Investigación , Índice de Severidad de la Enfermedad , Resultado del Tratamiento
15.
Br J Cancer ; 112(8): 1301-5, 2015 Apr 14.
Artículo en Inglés | MEDLINE | ID: mdl-25791875

RESUMEN

BACKGROUND: The combination of nab-paclitaxel plus gemcitabine (NAB-P+GEM) has shown superior efficacy over GEM monotherapy in metastatic pancreas cancer (MPC). Independent cost-effectiveness/utility analyses of NAB-P+GEM from the payer perspective have not been conducted for the UK. METHODS: A Markov model simulating the health outcomes and total costs was developed to estimate the life years gained (LYG) and quality-adjusted life years gained (QALY) and incremental cost-effectiveness (ICER) and cost-utility ratios (ICUR) for patients with MPC in a base case and in a probabilistic (PSA) sensitivity analysis. Total cost included the cost of supportive care medications, administration, chemotherapy, disease monitoring, and adverse reactions; and was discounted at 3.5% per year. A full lifetime horizon and third party payer perspective was chosen. RESULTS: The total cost of NAB-P+GEM was £5466 higher than the cost for GEM. Respectively, LYGs were 0.97 vs 0.79 and QALYs were 0.52 vs 0.45, with ICER of £30 367/LYG and ICUR of £78 086/QALY, confirmed by PSA. CONCLUSIONS: The superior survival efficacy of NAB-P+GEM over GEM in the management of MPC is associated with positive cost-effectiveness and cost-utility.


Asunto(s)
Antimetabolitos Antineoplásicos/economía , Protocolos de Quimioterapia Combinada Antineoplásica/economía , Desoxicitidina/análogos & derivados , Neoplasias Pancreáticas/tratamiento farmacológico , Adulto , Albúminas/administración & dosificación , Albúminas/economía , Antimetabolitos Antineoplásicos/administración & dosificación , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Análisis Costo-Beneficio , Desoxicitidina/administración & dosificación , Desoxicitidina/economía , Humanos , Cadenas de Markov , Persona de Mediana Edad , Modelos Económicos , Metástasis de la Neoplasia , Paclitaxel/administración & dosificación , Paclitaxel/economía , Neoplasias Pancreáticas/economía , Años de Vida Ajustados por Calidad de Vida , Análisis de Supervivencia , Reino Unido , Gemcitabina
16.
Malar J ; 14: 54, 2015 Feb 05.
Artículo en Inglés | MEDLINE | ID: mdl-25651815

RESUMEN

BACKGROUND: Plasmodium falciparum is the most pathogenic of the human malaria parasite species and a major cause of death in Africa. It's resistance to most of the current drugs accentuates the pressing need for new chemotherapies. Polyamine metabolism of the parasite is distinct from the human pathway making it an attractive target for chemotherapeutic development. Plasmodium falciparum spermidine synthase (PfSpdS) catalyzes the synthesis of spermidine and spermine. It is a major polyamine flux-determining enzyme and spermidine is a prerequisite for the post-translational activation of P. falciparum eukaryotic translation initiation factor 5A (elF5A). The most potent inhibitors of eukaryotic SpdS's are not specific for PfSpdS. METHODS: 'Dynamic' receptor-based pharmacophore models were generated from published crystal structures of SpdS with different ligands. This approach takes into account the inherent flexibility of the active site, which reduces the entropic penalties associated with ligand binding. Four dynamic pharmacophore models were developed and two inhibitors, (1R,4R)-(N1-(3-aminopropyl)-trans-cyclohexane-1,4-diamine (compound 8) and an analogue, N-(3-aminopropyl)-cyclohexylamine (compound 9), were identified. RESULTS: A crystal structure containing compound 8 was solved and confirmed the in silico prediction that its aminopropyl chain traverses the catalytic centre in the presence of the byproduct of catalysis, 5'-methylthioadenosine. The IC50 value of compound 9 is in the same range as that of the most potent inhibitors of PfSpdS, S-adenosyl-1,8-diamino-3-thio-octane (AdoDATO) and 4MCHA and 100-fold lower than that of compound 8. Compound 9 was originally identified as a mammalian spermine synthase inhibitor and does not inhibit mammalian SpdS. This implied that these two compounds bind in an orientation where their aminopropyl chains face the putrescine binding site in the presence of the substrate, decarboxylated S-adenosylmethionine. The higher binding affinity and lower receptor strain energy of compound 9 compared to compound 8 in the reversed orientation explained their different IC50 values. CONCLUSION: The specific inhibition of PfSpdS by compound 9 is enabled by its binding in the additional cavity normally occupied by spermidine when spermine is synthesized. This is the first time that a spermine synthase inhibitor is shown to inhibit PfSpdS, which provides new avenues to explore for the development of novel inhibitors of PfSpdS.


Asunto(s)
Antimaláricos/aislamiento & purificación , Antimaláricos/farmacología , Inhibidores Enzimáticos/aislamiento & purificación , Inhibidores Enzimáticos/farmacología , Plasmodium falciparum/enzimología , Espermidina Sintasa/antagonistas & inhibidores , Antimaláricos/química , Inhibidores Enzimáticos/química , Concentración 50 Inhibidora , Simulación de Dinámica Molecular , Unión Proteica
17.
Phys Rev Lett ; 113(26): 261103, 2014 Dec 31.
Artículo en Inglés | MEDLINE | ID: mdl-25615299

RESUMEN

Many of the technical complications associated with the general theory of relativity ultimately stem from the nonlinearity of Einstein's equation. It is shown here that an appropriate choice of dynamical variables may be used to eliminate all such nonlinearities beyond a particular order: Both Landau-Lifshitz and tetrad formulations of Einstein's equation are obtained that involve only finite products of the unknowns and their derivatives. Considerable additional simplifications arise in physically interesting cases where metrics become approximately Kerr or, e.g., plane waves, suggesting that the variables described here can be used to efficiently reformulate perturbation theory in a variety of contexts. In all cases, these variables are shown to have simple geometrical interpretations that directly relate the local causal structure associated with the metric of interest to the causal structure associated with a prescribed background. A new method to search for exact solutions is outlined as well.

18.
Biochem J ; 449(1): 175-87, 2013 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-23039077

RESUMEN

Malaria tropica is a devastating infectious disease caused by Plasmodium falciparum. This parasite synthesizes vitamin B6 de novo via the PLP (pyridoxal 5'-phosphate) synthase enzymatic complex consisting of PfPdx1 and PfPdx2 proteins. Biosynthesis of PLP is largely performed by PfPdx1, ammonia provided by PfPdx2 subunits is condensed together with R5P (D-ribose 5-phosphate) and G3P (DL-glyceraldehyde 3-phosphate). PfPdx1 accommodates both the R5P and G3P substrates and intricately co-ordinates the reaction mechanism, which is composed of a series of imine bond formations, leading to the production of PLP. We demonstrate that E4P (D-erythrose 4-phosphate) inhibits PfPdx1 in a dose-dependent manner. We propose that the acyclic phospho-sugar E4P, with a C1 aldehyde group similar to acyclic R5P, could interfere with R5P imine bond formations in the PfPdx1 reaction mechanism. Molecular docking and subsequent screening identified the E4P hydrazide analogue 4PEHz (4-phospho-D-erythronhydrazide), which selectively inhibited PfPdx1 with an IC50 of 43 µM. PfPdx1 contained in the heteromeric PLP synthase complex was shown to be more sensitive to 4PEHz and was inhibited with an IC50 of 16 µM. Moreover, the compound had an IC50 value of 10 µM against cultured P. falciparum intraerythrocytic parasites. To analyse further the selectivity of 4PEHz, transgenic cell lines overexpressing PfPdx1 and PfPdx2 showed that additional copies of the protein complex conferred protection against 4PEHz, indicating that the PLP synthase is directly affected by 4PEHz in vivo. These PfPdx1 inhibitors represent novel lead scaffolds which are capable of targeting PLP biosynthesis, and we propose this as a viable strategy for the development of new therapeutics against malaria.


Asunto(s)
Antimaláricos/farmacología , Plasmodium falciparum/efectos de los fármacos , Complejo Piruvato Deshidrogenasa/antagonistas & inhibidores , Animales , Antimaláricos/química , Humanos , Ácidos Hidroxámicos/química , Ácidos Hidroxámicos/farmacología , Plasmodium falciparum/fisiología , Complejo Piruvato Deshidrogenasa/química , Especificidad por Sustrato , Fosfatos de Azúcar/química , Fosfatos de Azúcar/farmacología
19.
Eur J Cancer Care (Engl) ; 23(3): 370-9, 2014 May.
Artículo en Inglés | MEDLINE | ID: mdl-24152297

RESUMEN

Erlotinib has been shown to prolong progression-free (PFS) and overall survival (OS) in patients with advanced non-small cell lung cancer (NSCLC). We report here on effectiveness data on the subsample of 261 patients from 40 centres in Belgium involved in the TRUST study. Median age was 63 years. Most (69.0%) were male and current/former smokers (84.7%); with Eastern Cooperative Oncology Group (ECOG) performance status (PS) of 0 or 1 (74.3%), stage IV disease (75.1%) and adenocarcinoma by histology (54.0%). Erlotinib was administered mainly as second- (47.1%) or third-line treatment (48.3%). Response rate was 6.5%; disease control rate 58.3%. Median PFS was 2.2 months. Better PS (P = 0.0384), stage IIIB disease (P = 0.0018) and presence of rash (P < 0.0001) were associated with longer PFS. OS rates at 1, 2 and 3 years were 26.4%, 10.9% and 6.4% respectively. Median OS was 5.9 months. Female gender (P = 0.007), better PS (P < 0.0001), stage IIIB disease (P = 0.0355) and presence of rash (P < 0.0001) were associated with longer OS. The findings confirm the therapeutic benefit of erlotinib in a broad range of patients in a sample from a country with a historically high lung cancer morbidity and mortality burden. Several determinants of PFS and OS are identified.


Asunto(s)
Adenocarcinoma/tratamiento farmacológico , Carcinoma de Células Grandes/tratamiento farmacológico , Carcinoma de Pulmón de Células no Pequeñas/tratamiento farmacológico , Carcinoma de Células Escamosas/tratamiento farmacológico , Receptores ErbB/antagonistas & inhibidores , Neoplasias Pulmonares/tratamiento farmacológico , Inhibidores de Proteínas Quinasas/uso terapéutico , Quinazolinas/uso terapéutico , Adenocarcinoma/mortalidad , Adenocarcinoma/patología , Anciano , Carcinoma de Células Grandes/mortalidad , Carcinoma de Células Grandes/patología , Carcinoma de Pulmón de Células no Pequeñas/mortalidad , Carcinoma de Pulmón de Células no Pequeñas/patología , Carcinoma de Células Escamosas/mortalidad , Carcinoma de Células Escamosas/patología , Supervivencia sin Enfermedad , Clorhidrato de Erlotinib , Femenino , Humanos , Neoplasias Pulmonares/mortalidad , Neoplasias Pulmonares/patología , Masculino , Persona de Mediana Edad , Tasa de Supervivencia , Resultado del Tratamiento
20.
Eur Rev Med Pharmacol Sci ; 28(3): 1144-1154, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38375720

RESUMEN

OBJECTIVE: Oxidative stress represents a ruthless complication of ß-thalassemia that worsens the severity of that medical condition. There is no conclusive evidence on the best antioxidant used for that issue. Our earlier clinical study concluded that omega-3 and Manuka honey add-on to the conventional therapy had a potential therapeutic impact on reducing oxidative stress. However, there is no research evaluating their cost-effectiveness. This paper compares the cost-effectiveness of Omega-3 and Manuka honey supplementation to conventional therapy in treating oxidative stress among children with ß-thalassemia major. SUBJECTS AND METHODS: Cost-effectiveness evaluation of daily supplementation of Omega-3-Manuka honey and Manuka honey alone to the conventional therapy was performed. The economic evaluation was performed on data from a prospective 10-month randomized clinical trial. Fifty patients were recruited into the Omega-3-Manuka honey plus conventional therapy group, 50 patients were included in the Manuka honey alone plus conventional therapy group, and 50 patients receiving the conventional therapy alone served as a control group. Effectiveness measures from the randomized clinical trial were used to determine incremental effectiveness. Cost estimates were calculated from the healthcare payer's perspective. The analysis considered the improvement in oxidative stress biomarkers presented here as a percent change from baseline to determine the incremental effectiveness and cost for the treatment by both interventions. RESULTS: Adding Omega-3 or Manuka honey to conventional therapy was a more cost-effective add-on than conventional treatment alone. Omega-3-Manuka honey was more cost-effective than Manuka honey alone in treating oxidative stress in that condition. Oxidative stress biomarkers were significantly reduced with both experimental medications compared to the conventional therapy alone. CONCLUSIONS: The present study showed that using Manuka honey and Omega-3 as add-on treatments for oxidative stress in pediatric ß-thalassemia disease could have significant cost-saving and clinical improvement.


Asunto(s)
Miel , Talasemia beta , Humanos , Niño , Talasemia beta/tratamiento farmacológico , Análisis de Costo-Efectividad , Estudios Prospectivos , Estrés Oxidativo , Biomarcadores
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