Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 31
Filtrar
1.
Rev Esp Cardiol (Engl Ed) ; 77(7): 566-573, 2024 Jul.
Artículo en Inglés, Español | MEDLINE | ID: mdl-38580141

RESUMEN

The practice of recreational scuba diving has increased worldwide, with millions of people taking part each year. The aquatic environment is a hostile setting that requires human physiology to adapt by undergoing a series of changes that stress the body. Therefore, physical fitness and control of cardiovascular risk factors are essential for practicing this sport. Medical assessment is not mandatory before participating in this sport and is only required when recommended by a health questionnaire designed for this purpose. However, due to the significance of cardiovascular disease, cardiology consultations are becoming more frequent. The aim of the present consensus document is to describe the cardiovascular physiological changes that occur during diving, focusing on related cardiovascular diseases, their management, and follow-up recommendations. The assessment and follow-up of individuals who practice diving with previous cardiovascular disease are also discussed. This document, endorsed by the Clinical Cardiology Association of the Spanish Society of Cardiology (SEC) and the SEC Working Group on Sports Cardiology of the Association of Preventive Cardiology, aims to assist both cardiologists in evaluating patients, as well as other specialists responsible for assessing individuals' fitness for diving practice.


Asunto(s)
Cardiología , Enfermedades Cardiovasculares , Buceo , Humanos , Buceo/efectos adversos , Buceo/fisiología , Enfermedades Cardiovasculares/terapia , Enfermedades Cardiovasculares/prevención & control , Sociedades Médicas , Consenso , España , Medicina Deportiva/métodos , Medicina Deportiva/normas , Recreación/fisiología
2.
Am J Cardiol ; 211: 9-16, 2024 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-37858663

RESUMEN

Lipoprotein(a) (Lp[a]) is an emerging risk factor for incident ischemic heart disease. However, its role in risk stratification in in-hospital survivors to an index acute myocardial infarction (AMI) is scarcer, especially for predicting the risk of long-term recurrent AMI. We aimed to assess the relation between Lp(a) and very long-term recurrent AMI after an index episode of AMI. It is a retrospective analysis that included 1,223 consecutive patients with an AMI discharged from October 2000 to June 2003 in a single-teaching center. Lp(a) was assessed during index admission in all cases. The relation between Lp(a) at discharge and total recurrent AMI was evaluated through negative binomial regression. The mean age of the patients was 67.0 ± 12.3 years, 379 (31.0%) were women, and 394 (32.2%) were diabetic. The index event was more frequently non-ST-segment elevation myocardial infarction (66.0%). The median Lp(a) was 28.8 (11.8 to 63.4) mg/100 ml. During a median follow-up of 9.9 (4.6 to 15.5) years, 813 (66.6%) deaths and 1,205 AMI in 532 patients (43.5%) occurred. Lp(a) values were not associated with an increased risk of long-term all-cause mortality (p = 0.934). However, they were positively and nonlinearly associated with an increased risk of total long-term reinfarction (p = 0.016). In the subgroup analysis, there was no evidence of a differential effect for the most prevalent subgroups. In conclusion, after an AMI, elevated Lp(a) values assessed during hospitalization were associated with an increased risk of recurrent reinfarction in the very long term. Further prospective studies are warranted to evaluate their clinical implications.


Asunto(s)
Infarto del Miocardio , Isquemia Miocárdica , Infarto del Miocardio sin Elevación del ST , Humanos , Femenino , Persona de Mediana Edad , Anciano , Masculino , Estudios Retrospectivos , Lipoproteína(a) , Infarto del Miocardio/epidemiología , Hospitalización , Factores de Riesgo
3.
J Clin Lipidol ; 17(5): 602-611, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37775463

RESUMEN

BACKGROUND: Statins are the cornerstone of lipid-lowering therapy (LLT) for reduction of low-density lipoprotein cholesterol (LDLc) levels and high percentage of patients require LLT combinations or alternative treatments for adequate LDLc control. METHODS: We performed an intention-to-treat meta-analysis of published data of phase III trials evaluating LLT efficacy on major adverse cardiovascular events (MACE). The primary endpoint was MACE incidence, as reported in each trial, and secondary analyses included myocardial infarction, stroke and mortality. RESULTS: Eleven clinical trials and 135,688 patients were included; seven trials tested high intensity LLT and 4 LLT combinations. Intensive LLT reduced MACE risk by 15% (12.03% vs. 13.79%, HR: 0.85 95% CI 0.80-0.90; p<0.001). The number needed to treat was 56 patients. Meta-regression analyses showed a linear correlation between absolute LDLc reductions and the risk of MACE. Significant reductions in myocardial infarction (HR: 0.83, 95% CI 0.80-0.86) and stroke (HR: 0.81, 95% CI 0.75-0.87) were observed. Cardiovascular death rate was 3.32% in LLT treatment arm vs. 3.56% in controls, resulting in a HR: 0.94 (95% CI 0.88-0.99; p = 0.03); no effect on all-cause mortality was observed (HR: 0.97 95% CI 0.93-1.01; p = 0.09). The sensitivity analyses verified the lack of heterogeneity, except for MACE that was mainly driven by the divergent results of the 2 trials. Small study effect was detected for the assessment of mortality. CONCLUSIONS: Current evidence consistently supports the efficacy of available intensity LLT for LDLc decrease on MACE and cardiovascular mortality reduction.


Asunto(s)
Enfermedades Cardiovasculares , Inhibidores de Hidroximetilglutaril-CoA Reductasas , Infarto del Miocardio , Accidente Cerebrovascular , Humanos , Enfermedades Cardiovasculares/tratamiento farmacológico , Enfermedades Cardiovasculares/prevención & control , LDL-Colesterol , Inhibidores de Hidroximetilglutaril-CoA Reductasas/uso terapéutico , Accidente Cerebrovascular/prevención & control , Ensayos Clínicos Fase III como Asunto
4.
Am J Cardiol ; 205: 321-324, 2023 10 15.
Artículo en Inglés | MEDLINE | ID: mdl-37633067

RESUMEN

Bempedoic acid is a selective inhibitor of the adenosine triphosphate citrate lyase that reduces low-density lipoprotein cholesterol (LDLc) levels by 17% to 28%. Although the Evaluation of Major Cardiovascular Events in Patients With, or at High Risk for, Cardiovascular Disease Who Are Statin Intolerant Treated With Bempedoic Acid (CLEAR-OUTCOMES) trials demonstrated the efficacy on cardiovascular outcomes there is a controversy related to the possible net clinical benefit. Thereafter, we performed an intention-to-treat meta-analysis in line with recommendations from the Cochrane Collaboration and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. The primary outcome of the metanalysis was the incidence of major adverse cardiovascular events, defined by each study protocol. Secondary outcomes for the analyses were myocardial infarction, stroke, myocardial revascularization, cardiovascular death, and all-cause death. Results of 4 clinical trials evaluated contained a total of 17,324 patients; 9,236 received bempedoic acid for a median of 46.6 months. The mean baseline LDLc was 129.4 (22.8) mg/100 ml and treatment was associated with a mean LDLc reduction of 26.0 (12.6) mg/100 ml. Treatment with bempedoic acid significantly reduced the incidence of major adverse cardiovascular events (hazard ratio [HR] 0.88, 95% confidence interval [CI] 0.81 to 0.96), myocardial infarction (HR 0.76, 95% CI 0.66 to 0.89) and myocardial revascularization (HR 0.82, 95% CI 0.73 to 0.92); the crude incidence of stroke, cardiovascular or all-cause mortality were lower in patients in the bempedoic acid groups although no significant risk reduction was observed. No heterogeneity was observed in any of the end points. In conclusion, the metanalysis of the 4 clinical trials currently available with bempedoic acid provides reliable evidence of its clinical benefit with no signs of heterogeneity or harm.


Asunto(s)
Infarto del Miocardio , Accidente Cerebrovascular , Humanos , Ensayos Clínicos Controlados Aleatorios como Asunto , Ácidos Dicarboxílicos/uso terapéutico , Ácidos Grasos/uso terapéutico , Infarto del Miocardio/tratamiento farmacológico , Infarto del Miocardio/epidemiología
6.
J Cardiovasc Pharmacol ; 81(1): 70-75, 2023 01 01.
Artículo en Inglés | MEDLINE | ID: mdl-36219195

RESUMEN

ABSTRACT: Low-density lipoprotein cholesterol (LDLc) is the lead effector of atherosclerosis and main treatment target. Bempedoic acid is a novel oral drug in the therapeutic armamentarium which is able to reduce LDLc. The objectives of this study were (1) to select the potential patients for administering bempedoic acid such as those with a very high cardiovascular risk in which objectives of LDLc were not achieved despite conventional treatment with PCSK9 inhibitors (PCSK9i) and/or statins and ezetimibe and (2) to estimate the cost-effectiveness of bempedoic acid in different scenarios. The methods used were a multicenter and retrospective study of 652 patients initiating treatment with any PCSK9 inhibitor in 17 different hospitals. Before and on-treatment LDLc cholesterol levels, medical treatments, clinical indication, and baseline characteristics were recorded. The results obtained from 443 subjects in secondary prevention were analyzed. The mean (±) LDLc level at baseline was 142.5 ± 46.4 mg/dL and 61.5 ± 40.5 mg/dL in the follow-up, with a reduction of 55.9% ( P < 0.0001); 71.6% of the patients reached the target of LDL < 55 mg/dL or >50% reduction. Of those patients treated with medium-intensity and low-intensity statins plus PCSK9 inhibitors (with or without ezetimibe), only 5.7% of them were able to reduce LDL below 55 mg/dL and the main LDLc reduction in this group was the lowest (42.9% on average). Patients with TG values >135 mg/dL represented 41.6% of the sample, of which approximately 10% of them were using fibrates. Assuming only LDLc reduction and the UK price, the incremental cost-effectiveness ratio was 88,359€; 83,117€; 82,378€; and 79,015€ for different discount rates. In conclusion, one-third of the patients could achieve the target LDL proposed in the 2019 ESC/EAS guidelines. Approximately 10% of them could also benefit from treating hypertriglyceridemia as indicated in the 2021 ESC guidelines on cardiovascular disease prevention. Patients with medium-intensity and low-intensity statins plus PCSK9i and ezetimibe would be the most benefited. Bempedoic acid could be a not cost-efficacy therapy in all the scenarios, but we need to wait for the CLEAR OUTCOMES Trial results.


Asunto(s)
Anticolesterolemiantes , Enfermedades Cardiovasculares , Inhibidores de Hidroximetilglutaril-CoA Reductasas , Humanos , Anticolesterolemiantes/efectos adversos , Enfermedades Cardiovasculares/diagnóstico , Enfermedades Cardiovasculares/tratamiento farmacológico , Enfermedades Cardiovasculares/epidemiología , LDL-Colesterol , Análisis de Costo-Efectividad , Ezetimiba/efectos adversos , Factores de Riesgo de Enfermedad Cardiaca , Inhibidores de Hidroximetilglutaril-CoA Reductasas/efectos adversos , Inhibidores de PCSK9 , Proproteína Convertasa 9 , Estudios Retrospectivos , Factores de Riesgo
8.
Glob Heart ; 17(1): 75, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36382159

RESUMEN

Background: Atherosclerotic cardiovascular diseases (ASCVD) including myocardial infarction, stroke and peripheral arterial disease continue to be major causes of premature death, disability and healthcare expenditure globally. Preventing the accumulation of cholesterol-containing atherogenic lipoproteins in the vessel wall is central to any healthcare strategy to prevent ASCVD. Advances in current concepts about reducing cumulative exposure to apolipoprotein B (apo B) cholesterol-containing lipoproteins and the emergence of novel therapies provide new opportunities to better prevent ASCVD. The present update of the World Heart Federation Cholesterol Roadmap provides a conceptual framework for the development of national policies and health systems approaches, so that potential roadblocks to cholesterol management and thus ASCVD prevention can be overcome. Methods: Through a review of published guidelines and research papers since 2017, and consultation with a committee composed of experts in clinical management of dyslipidaemias and health systems research in low-and-middle income countries (LMICs), this Roadmap identifies (1) key principles to effective ASCVD prevention (2) gaps in implementation of these interventions (knowledge-practice gaps); (3) health system roadblocks to treatment of elevated cholesterol in LMICs; and (4) potential strategies for overcoming these. Results: Reducing the future burden of ASCVD will require diverse approaches throughout the life-course. These include: a greater focus on primordial prevention; availability of affordable cholesterol testing; availability of universal cholesterol screening for inherited dyslipidaemias; risk stratification moving beyond 10-year risk to look at lifetime risk with adequate risk estimators; wider availability of affordable cholesterol-lowering therapies which should include statins as essential medications globally; use of adequate doses of potent statin regimens; and combination therapies with ezetimibe or other therapies in order to attain and maintain robust reductions in LDL-C in those at highest risk. Continuing efforts are needed on health literacy for both the public and healthcare providers, utilising multi-disciplinary teams in healthcare and applications that quantify both ASCVD risk and benefits of treatment as well as increased adherence to therapies. Conclusions: The adverse effects of LDL-cholesterol and apo B containing lipoprotein exposure are cumulative and result in ASCVD. These are preventable by implementation of different strategies, aimed at efficiently tackling atherosclerosis at different stages throughout the human life-course. Preventive strategies should therefore be updated to implement health policy, lifestyle changes and when needed pharmacotherapies earlier with investment in, and a shift in focus towards, early preventive strategies that preserve cardiovascular health rather than treat the consequences of ASCVD.


Asunto(s)
Aterosclerosis , Enfermedades Cardiovasculares , Dislipidemias , Inhibidores de Hidroximetilglutaril-CoA Reductasas , Humanos , Colesterol , Inhibidores de Hidroximetilglutaril-CoA Reductasas/uso terapéutico , Aterosclerosis/diagnóstico , Lipoproteínas/uso terapéutico , Apolipoproteínas B/uso terapéutico , Enfermedades Cardiovasculares/epidemiología , Enfermedades Cardiovasculares/prevención & control , Enfermedades Cardiovasculares/diagnóstico
9.
J Geriatr Cardiol ; 19(5): 377-392, 2022 May 28.
Artículo en Inglés | MEDLINE | ID: mdl-35722032

RESUMEN

In recent decades, life expectancy has been increasing significantly. In this scenario, health interventions are necessary to improve prognosis and quality of life of elderly with cardiovascular risk factors and cardiovascular disease. However, the number of elderly patients included in clinical trials is low, thus current clinical practice guidelines do not include specific recommendations. This document aims to review prevention recommendations focused in patients ≥ 75 years with high or very high cardiovascular risk, regarding objectives, medical treatment options and also including physical exercise and their inclusion in cardiac rehabilitation programs. Also, we will show why geriatric syndromes such as frailty, dependence, cognitive impairment, and nutritional status, as well as comorbidities, ought to be considered in this population regarding their important prognostic impact.

10.
J Clin Med ; 10(22)2021 Nov 12.
Artículo en Inglés | MEDLINE | ID: mdl-34830548

RESUMEN

Direct oral anticoagulants (DOACs) have been demonstrated to be more effective and safer than vitamin-K antagonist (VKA) for stroke prevention in patients with nonvalvular atrial fibrillation (AF). This meta-analysis aims to assess the effect of DOACS vs. VKA in patients ≥ 80 and AF. Primary endpoints were stroke or systemic embolism and all-cause death. Secondary endpoints included major bleeding, intracranial bleeding, and gastrointestinal bleeding. A random-effects model was selected due to significant heterogeneity. A total of 147,067 patients from 16 studies were included, 71,913 (48.90%) treated with DOACs and 75,154 with VKA (51.10%). The stroke rate was significantly lower in DOACs group compared with warfarin group (Relative risk (RR): 0.72; 95% confidence interval (CI): 0.63-0.82; p < 0.001). All-cause mortality was significantly lower in DOACs group compared with warfarin group (RR: 0.82; 95% CI: 0.70-0.96; p = 0.012). Compared to warfarin, DOACs were not associated with reductions in major bleeding (RR: 0.85, 95% CI 0.69-1.04; p = 0.108) or gastrointestinal bleeding risk (RR: 1.08, 95% CI 0.76-1.53; p = 0.678) but a 43% reduction of intracranial bleeding (RR: 0.47, IC 95% 0.36-0.60; p < 0.001) was observed. Our meta-analysis demonstrates that DOACs are effective and safe with statistical superiority when compared with warfarin in octogenarians with AF.

11.
Polymers (Basel) ; 13(13)2021 Jun 24.
Artículo en Inglés | MEDLINE | ID: mdl-34202848

RESUMEN

Among the different ways to reduce the secondary effects of antineoplastic drugs in cancer treatment, the use of nanoparticles has demonstrated good results due to the protection of the drug and the possibility of releasing compounds to a specific therapeutic target. The α-isoform of the folate receptor (FR) is overexpressed on a significant number of human cancers; therefore, folate-targeted crosslinked nanoparticles based on BSA and alginate mixtures and loaded with paclitaxel (PTX) have been prepared to maximize the proven antineoplastic activity of the drug against solid tumors. Nanometric-range-sized particles (169 ± 28 nm-296 ± 57 nm), with negative Z-potential values (between -0.12 ± 0.04 and -94.1± 0.4), were synthesized, and the loaded PTX (2.63 ± 0.19-3.56 ±0.13 µg PTX/mg Np) was sustainably released for 23 and 27 h. Three cell lines (MCF-7, MDA-MB-231 and HeLa) were selected to test the efficacy of the folate-targeted PTX-loaded BSA/ALG nanocarriers. The presence of FR on the cell membrane led to a significantly larger uptake of BSA/ALG-Fol nanoparticles compared with the equivalent nanoparticles without folic acid on their surface. The cell viability results demonstrated a cytocompatibility of unloaded nanoparticle-Fol and a gradual decrease in cell viability after treatment with PTX-loaded nanoparticle-Fol due to the sustainable PTX release.

12.
Int J Pharm ; 554: 337-351, 2019 Jan 10.
Artículo en Inglés | MEDLINE | ID: mdl-30439492

RESUMEN

In this study, a new alternative of ionic crosslinked nanoparticles (NPs) based on chitosan (C) and bovine serum albumin (A; BSA) was evaluated as drug delivery system for antitumour compounds (doxorubicin hydrochloride as a model). The different responses to the pH of the medium were determined by the electrostatic interactions induced by each polymeric combination (C50/A50; C80/A20; C20/A80). NPs revealed a nanoscale size (167-392 nm) and a positive net charge (12-26 mV), modulated by doxorubicin (DOX) loading. Drug loading capacity was higher than 5.2 ±â€¯1.8 µgDOX/mgNP (Encapsulation efficiency = 34%), and an initial burst release was followed by a sustained delivery. Cellular uptake assays confirmed the entry of NPs in three human tumor cells (MCF7, T47D and Hela), triggering antioxidant responses (superoxide dismutase, catalase, glutathione reductase and total glutathione content) in those cells. This was also consistent with the decreased in IC50 values observed after the incubation of these cells with C20/A80-DOX and C50/A50-DOX NPs (1.90-3.48 µg/mL) compared with free DOX (2.36-6.025 µg/mL). In vivo results suggested that the selected proportions of chitosan-BSA created nonhemolytic and biocompatible stable NPs at the selected dose of 20 mg/kg. Despite the different formulations, this study demonstrated that these NPs could serve as safe drug carriers in further in vivo investigations.


Asunto(s)
Doxorrubicina/administración & dosificación , Portadores de Fármacos/química , Sistemas de Liberación de Medicamentos , Nanopartículas , Administración Intravenosa , Animales , Antibióticos Antineoplásicos/administración & dosificación , Antibióticos Antineoplásicos/farmacología , Antibióticos Antineoplásicos/toxicidad , Línea Celular Tumoral , Química Farmacéutica/métodos , Quitosano/química , Reactivos de Enlaces Cruzados/química , Preparaciones de Acción Retardada , Doxorrubicina/farmacología , Doxorrubicina/toxicidad , Femenino , Humanos , Concentración de Iones de Hidrógeno , Concentración 50 Inhibidora , Ratas , Ratas Wistar , Albúmina Sérica Bovina/química
13.
J Dermatolog Treat ; 29(4): 393-399, 2018 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-28956675

RESUMEN

INTRODUCTION: The aim of the study was to evaluate the results on effectiveness and safety of topical treatment for actinic keratosis (AK) with ingenol mebutate gel (IMG) in real-life conditions and to perform an analysis of the factors that may influence the treatment outcomes. MATERIALS AND METHODS: Retrospective study of patients with non-hyperkeratotic AK lesions prescribed with IMG in Spain according to clinical practice. Dermatologists reported the characteristics of patients and AK at baseline, and the findings observed up to 60 d after treatment. RESULTS AND CONCLUSIONS: A total of 260 treatments in 246 patients with a mean (SD) age 70.6 (10.4) years were reviewed. The number of clinically visible AK in the treated area decreased from 6.16 (3.02) to 1.22 (2.02) (p < .001) lesions with an average reduction of 84%. Univariate analysis showed higher reduction rates when IMG was applied in the face/scalp (p = .026), in women (p = .041), and in patients under 70 years of age (p = .033). According to multivariate analysis, advanced age was associated with worse clearance rates (p = .038). However, besides statistical significance, we can conclude that gender (female) and age (under 70 years-old) show a tendency to have better efficacy outcomes but without clinical relevance. Topical IMG was generally well tolerated and had positive cosmetic results after 60 d. Age influences on IMG effectiveness for AK and LSRs were correlated with higher effectiveness ratios.


Asunto(s)
Diterpenos/uso terapéutico , Queratosis Actínica/tratamiento farmacológico , Administración Tópica , Adulto , Factores de Edad , Anciano , Anciano de 80 o más Años , Diterpenos/química , Cara/patología , Femenino , Geles/química , Humanos , Masculino , Persona de Mediana Edad , Análisis Multivariante , Satisfacción del Paciente , Estudios Retrospectivos , Cuero Cabelludo/patología , Resultado del Tratamiento
14.
Colloids Surf B Biointerfaces ; 136: 222-31, 2015 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-26402420

RESUMEN

Nanotoxicology has emerged as an important subdiscipline of nanotechnology due to the new healthy risks associated with the use of nanosystems for therapy and diagnostic. The biocompatibility of four stimuli-responsive nanohydrogel (NG) formulations based on different proportions of N-isopropylacrylamide (NIPA), N-hydroxyethyl acrylamide (HEAA) and 2-acrylamidoethyl carbamate (2AAECM), and cross-linked with N,N-cystaminebisacrylamide (CBA) or N-methylenebisacrylamide (NMBA) has been evaluated after intravenous injection in Wistar rats. All nanohydrogels were pH-sensitive, and those with CBA were also glutathione-responsive. Haematological and coagulation parameters revealed most nanogel formulations did not cause modification, only the NHA 80/15/5-CBA formulation induced a transitory light increase in platelets. Prothrombin time was in the reference normal range, there were no modifications of fibrinogen concentration and an increase in antithrombin III was observed on the last day of the study. Blood biochemical parameters such as AST, ALT, ALP, BUN, and creatinine were in the standard range for rats. The activity of enzyme antioxidant defences (SOD, CAT and GSSG-R) and total glutathione were evaluated in liver, kidney and spleen samples. Nanohydrogels cross-linked with the disulphide reducible CBA-cross-linker caused a decrease in GSSG/GSH content and an increase in GSSG-R activity in the spleen. The antioxidant response is also reflected by modifications of SOD activity in liver and kidney of NHA 80/15/5-CBA and NHA 80/10/10-NMBA groups. Histology showed no tissue damage, inflammation or morphological change in liver, kidney and spleen. Overall, the results demonstrated modifications of antioxidant defences; however, no acute or very significant changes in biomarkers of liver or kidney damage were observed.


Asunto(s)
Materiales Biocompatibles , Glutatión/química , Hidrogeles , Nanoestructuras , Animales , Pruebas de Coagulación Sanguínea , Catalasa/metabolismo , Glutatión/metabolismo , Glutatión Reductasa/metabolismo , Concentración de Iones de Hidrógeno , Inyecciones Intravenosas , Ratas , Ratas Wistar , Superóxido Dismutasa/metabolismo
15.
Int J Pharm ; 492(1-2): 10-9, 2015 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-26160666

RESUMEN

Most antitumor drugs usually affect not only rapidly dividing cells, such as those in tumors, but also highly proliferative cells in normal tissues. This nonspecific drawback could be successfully solved by using nanocarriers as controlled drug delivery systems. In this work, pH and redox-responsive nanohydrogels (NG) based on N-isopropylacrilamide (NIPA), N-hydroxyethyl acrylamide (HEEA) 2-acrylamidoethyl carbamate (2AAECM) and N,N'-cystaminebisacrylamide (CBA) as crosslinker were evaluated as bioreducible paclitaxel (PTX) nanocarriers for improving the accumulation of the drug within the tumor tissue and avoiding its conventional side effects. A single dose of PTX solution, unloaded-NHA 80/15/5CBA NG and PTX-loaded NHA 80/15/5-CBA NG (30 mg/kg PTX equivalent) were subcutaneously injected in female athymic nude mice bearing HeLa human tumor xenografts. PTX-loaded nanohydrogels showed higher antitumor activity than free PTX, as tumor evolution and Ki67 detection demonstrated. Histological tumor images revealed a higher content of defective mitotic figures and apoptotic bodies in PTX- treated tumors than in control or unloaded NG treated tumor samples. Nanohydrogels injection did not change any biochemical blood parameters, which means no liver or kidney damage after NG injection. However, differences in antioxidant defenses in MPS systems (liver, kidney and spleen) were observed among treatments, which may indicate an oxidative stress response after PTX injection.


Asunto(s)
Antineoplásicos Fitogénicos/administración & dosificación , Hidrogeles/administración & dosificación , Nanoestructuras/administración & dosificación , Paclitaxel/administración & dosificación , Animales , Antineoplásicos Fitogénicos/química , Antineoplásicos Fitogénicos/uso terapéutico , Catalasa/metabolismo , Femenino , Glutatión/metabolismo , Disulfuro de Glutatión/metabolismo , Células HeLa , Humanos , Hidrogeles/química , Hidrogeles/uso terapéutico , Concentración de Iones de Hidrógeno , Riñón/efectos de los fármacos , Riñón/metabolismo , Hígado/efectos de los fármacos , Hígado/metabolismo , Ratones Desnudos , Nanoestructuras/química , Nanoestructuras/uso terapéutico , Neoplasias/tratamiento farmacológico , Neoplasias/patología , Paclitaxel/química , Paclitaxel/uso terapéutico , Bazo/efectos de los fármacos , Bazo/metabolismo , Superóxido Dismutasa/metabolismo , Resultado del Tratamiento , Carga Tumoral/efectos de los fármacos , Ensayos Antitumor por Modelo de Xenoinjerto
16.
Anticancer Drugs ; 25(6): 641-51, 2014 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-24590166

RESUMEN

Microspheres of different proportions of poly-(D,L-lactide-co-glycolide) and poly-(D,L-lactide) were formulated by spray drying as a drug-delivery system for the treatment of breast cancer with tamoxifen. These systems had been evaluated previously in vitro and showed very positive results that have led to further assessment in vivo. This work evaluates the performance of these systems in an organism by carrying out a study in female Wistar rats. Microspheres were subcutaneously injected into the back of rats for the assessment of not only the biocompatibility but also the release of the drug contained and its biodistribution. As, in vitro, these systems could release the drug under physiological conditions; different plasma concentrations of tamoxifen and one of its metabolites, 4-hydroxy-tamoxifen, were achieved depending on the polymer composition. Microspheres could reduce the accumulation of the drug in different nontarget organs and presented good biocompatibility.


Asunto(s)
Antineoplásicos Hormonales/farmacocinética , Antagonistas de Estrógenos/farmacocinética , Poliésteres/química , Poliglactina 910/química , Tamoxifeno/farmacocinética , Animales , Antineoplásicos Hormonales/administración & dosificación , Neoplasias de la Mama/tratamiento farmacológico , Portadores de Fármacos , Antagonistas de Estrógenos/administración & dosificación , Femenino , Microesferas , Ratas , Ratas Wistar , Tamoxifeno/administración & dosificación , Distribución Tisular
17.
Colloids Surf B Biointerfaces ; 116: 247-56, 2014 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-24491841

RESUMEN

pH and glutathion (GSH)- responsive nanogels (NGs) based on poly-N-isopropylacrilamide (NIPA), N-hydroxyethyl acrylamide (HEAA) and tert-butyl 2-acrylamidoethyl carbamate (2AAECM) were synthesized by a microemulsion polymerization method using N, N'-cystaminebisacrylamide (CBA) as a crosslinking agent and evaluated for passive targeting of paclitaxel (PTX). Physicochemical characterizations of unloaded and PTX-loaded NGs, such as particle size, morphology, encapsulation efficiency and in vitro PTX release were also assessed. Electron microscopy techniques (SEM and TEM) as well as dynamic light scattering (DLS) analysis showed nanosized spherical hydrogels. FTIR spectra confirmed the synthesis of nanogels by free radical polymerization among vinyl groups of monomers. In vitro release was analyzed by high-performance liquid chromatography (HPLC) and differences between two NG formulations were obtained. Nanogels released almost 64% of PTX after 50h at GSH concentrations equivalent to that in the cellular cytosol, whereas less PTX was released from NGs at pH and GSH levels similar to plasma. Cellular uptake and cytotoxicity were also demonstrated by using coumarin-6 and MTT assays, respectively, for three tumor cell lines (MCF7, HeLa and T47D). Cellular uptake assays revealed rapid uptake within 2h and intracellular accumulation of coumarin-6-loaded nanogels after 48 h incubation. MTT assays showed changes in cell viability at different concentrations of PTX formulations, as well as pure PTX (10 µM, 20 µM and 30 µM). To investigate PTX effect on cell viability, changes in cell cycle were examined by flow cytometry and a G2/M cell arrest was demonstrated. Overall, synthesized nanogels may be used as potential carriers for hydrophobic anticancer drugs.


Asunto(s)
Antineoplásicos/administración & dosificación , Portadores de Fármacos/química , Glutatión/química , Hidrogel de Polietilenoglicol-Dimetacrilato/química , Paclitaxel/administración & dosificación , Antineoplásicos/química , Antineoplásicos/farmacología , Ciclo Celular/efectos de los fármacos , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Cumarinas/química , Relación Dosis-Respuesta a Droga , Portadores de Fármacos/síntesis química , Glutatión/síntesis química , Células HeLa , Humanos , Hidrogel de Polietilenoglicol-Dimetacrilato/síntesis química , Concentración de Iones de Hidrógeno , Células MCF-7 , Paclitaxel/química , Paclitaxel/farmacología , Tamaño de la Partícula , Relación Estructura-Actividad , Propiedades de Superficie , Tiazoles/química
18.
Biol Trace Elem Res ; 149(3): 405-11, 2012 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-22581110

RESUMEN

Modifications in the enzyme activity of lysozyme, a protein implied in the defence barrier of the organism, can be a good biomarker of alterations in the immune system as a result of exposure to toxic metal, such as lead. The aim of this work was to evaluate the effect of a 200 ppm dose of lead on lysozyme activity in blood, kidney, and lung, and also on tissue structure. Previously, the effect of lead acetate on lysozyme activity in vitro was determined; the in vitro results indicated that lead produced a decrease in enzyme activity. The activity loss was 16 % at 200 ppm of lead. Lead acetate was administered to Wistar rats by oral and intraperitoneal injections. An increase in lysozyme activity was observed in blood when lead was administered by introperitoneal route and in kidney by the oral route. The possible immunostimulation in kidney was discarded because of the structural alterations observed in the tissue. In lung, the decrease in specific lysozyme activity, for both routes of lead exposure, seems to indicate immunosupression, which was in accordance with the structural alterations observed in this tissue.


Asunto(s)
Riñón/enzimología , Plomo/administración & dosificación , Plomo/farmacología , Pulmón/enzimología , Muramidasa/metabolismo , Administración Oral , Animales , Activación Enzimática/efectos de los fármacos , Inyecciones Intraperitoneales , Masculino , Muramidasa/sangre , Ratas , Ratas Wistar
19.
J Microencapsul ; 29(4): 309-22, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22251238

RESUMEN

Nanoparticles (NP) from mixtures of two poly(D,L-lactide-co-caprolactone) (PLC) copolymers, PLC 40/60 and PLC 86/14, with poly(D,L-lactide) (PDLLA) and PCL were prepared: PLC 40/60-PCL (25:75), PLC 86/14-PCL (75:25) and PLC 86/14-PLA (75:25). Tamoxifen was loaded with encapsulation efficiency between 65% and 75% (29.9-36.3 µg TMX/ mg NP). All selected systems showed spherical shape and nano-scale size. TMX-loaded NPs were in the range of 293-352 nm. TMX release from NP took place with different profiles depending on polymeric composition of the particles. After 60 days, 59.81% and 82.65% of the loaded drug was released. The cytotoxicity of unloaded NP in MCF7 and HeLa cells was very low. Cell uptake of NP took place in both cell types by unspecific internalization in a time dependent process. The administration of 6 and 10 µm TMX by TMX-loaded NP was effective on both cellular types, mainly in MCF7 cells.


Asunto(s)
Composición de Medicamentos/métodos , Tamoxifeno/administración & dosificación , Antineoplásicos Hormonales/administración & dosificación , Materiales Biocompatibles/química , Neoplasias de la Mama/tratamiento farmacológico , Neoplasias de la Mama/patología , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Preparaciones de Acción Retardada , Sistemas de Liberación de Medicamentos , Femenino , Células HeLa , Humanos , Ensayo de Materiales , Microscopía Electrónica de Rastreo , Nanocápsulas/química , Nanocápsulas/ultraestructura , Nanotecnología , Poliésteres/química
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA