RESUMEN
Dual-species biofilms formed by Candida albicans and Staphylococcus aureus have high virulence and drug resistance. In this context, biosurfactants produced by Pseudomonas aeruginosa have been widely studied, of which a new derivative (RLmix_Arg) stands out for possible application in formulations. The objective of this study was to evaluate the antibiofilm activity of RLmix_Arg, both alone and incorporated in a gel prepared with Pluronic F-127, against dual-species biofilms of fluconazole-resistant C. albicans (FRCA) and methicillin-resistant S. aureus (MRSA) in impregnated catheters. Broth microdilution tests, MTT reduction assays of mature biofilms, impregnation of RLmix_Arg and its gel in peripheral venous catheters, durability tests and scanning electron microscopy (SEM) were performed. RLmix_Arg showed antimicrobial activity against Candida spp. and S. aureus, by reducing the cell viability of mixed biofilms of FRCA and MRSA, and preventing their formation in a peripheral venous catheter. The incorporation of this biosurfactant in the Pluronic F-127 gel considerably enhanced its antibiofilm activity. Thus, RLmix_Arg has potential application in gels for impregnation in peripheral venous catheters, helping to prevent development of dual-species biofilms of FRCA and MRSA.
Asunto(s)
Antiinfecciosos , Staphylococcus aureus Resistente a Meticilina , Fluconazol/farmacología , Candida albicans , Staphylococcus aureus , Resistencia a la Meticilina , Biopelículas , Poloxámero/farmacología , Pruebas de Sensibilidad Microbiana , Antiinfecciosos/farmacología , Catéteres , Antibacterianos/farmacologíaRESUMEN
BACKGROUND: This work proposes the development of new vesicular systems based on anesthetic compounds (lidocaine (LID) and capsaicin (CA)) and antimicrobial agents (amino acid-based surfactants from phenylalanine), with a focus on physicochemical characterization and the evaluation of antimicrobial and cytotoxic properties. METHOD: Phenylalanine surfactants were characterized via high-performance liquid chromatography (HPLC) and nuclear magnetic resonance (NMR). Different niosomal systems based on capsaicin, lidocaine, cationic phenylalanine surfactants, and dipalmitoyl phosphatidylcholine (DPPC) were characterized in terms of size, polydispersion index (PI), zeta potential, and encapsulation efficiency using dynamic light scattering (DLS), transmitted light microscopy (TEM), and small-angle X-ray scattering (SAXS). Furthermore, the interaction of the pure compounds used to prepare the niosomal formulations with DPPC monolayers was determined using a Langmuir balance. The antibacterial activity of the vesicular systems and their biocompatibility were evaluated, and molecular docking studies were carried out to obtain information about the mechanism by which these compounds interact with bacteria. RESULTS: The stability and reduced size of the analyzed niosomal formulations demonstrate their potential in pharmaceutical applications. The nanosystems exhibit promising antimicrobial activity, marking a significant advancement in pharmaceutical delivery systems with dual therapeutic properties. The biocompatibility of some formulations underscores their viability. CONCLUSIONS: The proposed niosomal formulations could constitute an important advance in the pharmaceutical field, offering delivery systems for combined therapies thanks to the pharmacological properties of the individual components.
Asunto(s)
Liposomas , Tensoactivos , Liposomas/química , Tensoactivos/química , Tensoactivos/farmacología , Aminoácidos/química , Antiinfecciosos/química , Antiinfecciosos/farmacología , Simulación del Acoplamiento Molecular , Anestésicos/química , Anestésicos/farmacología , Composición de Medicamentos , Pruebas de Sensibilidad MicrobianaRESUMEN
BACKGROUND: This risk analysis aimed to explore all modifiable factors associated with prolonged mechanical ventilation (lasting > 24 h) after liver transplantation, based on prospectively collected data from a clinical trial. METHODS: We evaluated 306 candidates. Ninety-three patients were excluded for low risk for transfusion (preoperative haemoglobin > 130 g.l-1), and 31 patients were excluded for anticoagulation therapy, bleeding disorders, familial polyneuropathy, or emergency status. Risk factors were initially identified with a log-binomial regression model. Relative risk was then calculated and adjusted for age, sex, and disease severity (Model for End-Stage Liver Disease [MELD] score). RESULTS: Early tracheal extubation was performed in 149 patients (84.7%), and 27 patients (15.3%) required prolonged mechanical ventilation. Reoperations were required for 6.04% of the early extubated patients and 44% of patients who underwent prolonged ventilation (p = 0.001). A MELD score > 23 was the main risk factor for prolonged ventilation. Once modifiable risk factors were adjusted for MELD score, sex, and age, three factors were significantly associated with prolonged ventilation: tranexamic acid (p = 0.007) and red blood cell (p = 0.001) infusion and the occurrence of postreperfusion syndrome (p = 0.004). The median (IQR) ICU stay was 3 (2-4) days in the early extubation group vs. 5 (3-10) days in the prolonged ventilation group (p = 0.001). The median hospital stay was also significantly shorter after early extubation, at 14 (10-24) days, vs. 25 (14-55) days in the prolonged ventilation group (p = 0.001). Eight patients in the early-extubation group (5.52%) were readmitted to the ICU, nearly all for reoperations, with no between-group differences in ICU readmissions (prolonged ventilation group, 3.7%). CONCLUSION: We conclude that bleeding and postreperfusion syndrome are the main modifiable factors associated with prolonged mechanical ventilation and length of ICU stay, suggesting that trials should explore vasopressor support strategies and other interventions prior to graft reperfusion that might prevent potential fibrinolysis. TRIAL REGISTRATION: European Clinical Trials Database (EudraCT 2018-002510-13,) and on ClinicalTrials.gov (NCT01539057).
Asunto(s)
Enfermedad Hepática en Estado Terminal , Trasplante de Hígado , Humanos , Hemorragia , Unidades de Cuidados Intensivos , Tiempo de Internación , Trasplante de Hígado/efectos adversos , Respiración Artificial , Factores de Riesgo , Índice de Severidad de la Enfermedad , Ensayos Clínicos como Asunto , Masculino , FemeninoRESUMEN
Cationic surfactants carry antimicrobial activity, based on their interaction and disruption of cell membranes. Nonetheless, their intrinsic toxicity limits their applicability. To overcome this issue, a feasible strategy consists of using solid nanoparticles to improve their delivery. The zein nanoparticles were loaded with four cationic arginine-based surfactants: one single chain Nα-lauroyl-arginine (LAM) and three Gemini surfactants Nα Nω-Bis (Nα-lauroyl-arginine) α, ω-diamide) (C3(LA)2, C6(LA)2 and C9(LA)2). Blank and loaded zein nanoparticles were characterized in terms of size, polydispersity and zeta potential. Furthermore, the antimicrobial activity against bacteria and yeasts and the hemolytic activity were investigated and compared to the surfactants in a solution. Nanoparticles were found to be monodisperse, presenting a size of between 180-341 nm, a pdI of <0.2 and a positive zeta potential of between +13 and +53 mV, remaining stable over 365 days. The nanoencapsulation maintained the antimicrobial activity as unaltered, while the extensive hemolytic activity found for the surfactants in a solution was reduced drastically. Nuclear Magnetic Ressonance (NMR), molecular docking and monolayer findings indicated that zein entraps the surfactants, interfering in the surfactant-membrane interactions. Accordingly, the nanoepcasulation of arginine surfactants improved their selectivity, while the cationic charges were free to attack and destroy bacteria and fungi; the aliphatic chains were not available to disrupt the cellular membranes.
Asunto(s)
Antiinfecciosos , Nanopartículas , Zeína , Tensoactivos/farmacología , Tensoactivos/química , Arginina/química , Simulación del Acoplamiento Molecular , Bacterias , Antiinfecciosos/farmacología , Antiinfecciosos/químicaRESUMEN
The antimicrobial and antibiofilm properties of arginine-based surfactants have been evaluated. These two biological properties depend on both the alkyl chain length and the spacer chain nature. These gemini surfactants exhibit good activity against a wide range of bacteria, including some problematic resistant microorganisms such us methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa. Moreover, surfactants with a C10 alkyl chain and C3 spacer inhibit the (MRSA) and Pseudomonas aeruginosa biofilm formation at concentrations as low as 8 µg/mL and are able to eradicate established biofilms of these two bacteria at 32 µg/mL. The inhibitory activities of the surfactants over key enzymes enrolled in the skin repairing processes (collagenase, elastase and hyaluronidase) were evaluated. They exhibited moderate anti-collagenase activity while the activity of hyaluronidase was boosted by the presence of these surfactants. These biological properties render these gemini arginine-based surfactants as perfect promising candidates for pharmaceutical and biological properties.
Asunto(s)
Antiinfecciosos , Staphylococcus aureus Resistente a Meticilina , Hialuronoglucosaminidasa , Antiinfecciosos/farmacología , Arginina , Biopelículas , Elastasa Pancreática , Pseudomonas aeruginosaRESUMEN
INTRODUCTION: Cirrhosis and liver cancer are currently common causes of death worldwide. The global epidemic of obesity has increased the incidence of nonalcoholic fatty liver disease (NAFLD) and cirrhosis in recent years. Advanced fibrosis increases the morbimortality rate in NAFLD. The Mexican population has one of the highest prevalence of obesity and diabetes mellitus (DM) worldwide. AIM: To determine the prevalence of advanced liver fibrosis in Mexican general population. METHODS: Adult individuals, without a history of liver disease nor heavy alcohol consumption were randomly sampled from 20,919 participants of a health and nutrition survey applied to the general population. Clinical and laboratory evaluations were performed to calculate the NAFLD fibrosis score (NFS) (an extensively validated non-invasive method). Two cut-off points were used. Advanced fibrosis was defined as a result >0.676. RESULTS: In total 695 individuals were included. The mean age was 47.8±16.4. The majority were between 20 and 50 years (59%), 70.2% were female, 35.5% showed obesity and 15.8% DM. The 93% had normal serum ALT. Based on the NFS results, 56 individuals (8.1%) had a high probability of fibrosis. Most patients from this subgroup showed normal serum ALT (92.9%), 89.3% were >45yr. old, 52% were obese and 27% suffered from DM. CONCLUSIONS: Based on these results, 8.1% of Mexican general population without a history of liver disease is at high risk of having advanced liver fibrosis and complications and death derived from cardiovascular disease and cirrhosis. Most of them showed normal ALT serum levels.
Asunto(s)
Diabetes Mellitus Tipo 2/epidemiología , Enfermedad del Hígado Graso no Alcohólico/epidemiología , Obesidad/epidemiología , Adulto , Anciano , Alanina Transaminasa/sangre , Aspartato Aminotransferasas/sangre , Femenino , Humanos , Cirrosis Hepática , Masculino , Tamizaje Masivo , México/epidemiología , Persona de Mediana Edad , Enfermedad del Hígado Graso no Alcohólico/sangre , Enfermedad del Hígado Graso no Alcohólico/diagnóstico por imagen , Recuento de Plaquetas , Prevalencia , Albúmina Sérica/metabolismoRESUMEN
The surface activity, aggregates morphology, size and charge characteristics of binary catanionic mixtures containing a cationic amino acid-derived surfactant N(π), N(τ)-bis(methyl)-L-Histidine tetradecyl amide (DMHNHC14) and an anionic surfactant (the lysine-based surfactant Nα-lauroyl-Nεacetyl lysine (C12C3L) or sodium myristate) were investigated for the first time. The cationic surfactant has an acid proton which shows a strong pKa shift irrespective of aggregation. The resulting catanionic mixtures exhibited high surface activity and low critical aggregation concentration as compared with the pure constituents. Catanionic vesicles based on DMHNHC14/sodium myristate showed a monodisperse population of medium-size aggregates and good storage stability. According to Small-Angle X-Ray Scattering (SAXS), the characteristics of the bilayers did not depend strongly on the system composition for the positively charged vesicles. Negatively charged vesicles (cationic surfactant:myristate ratio below 1:2) had similar bilayer composition but tended to aggregate. The DMHNHC14-rich vesicles exhibited good antibacterial activity against Gram-positive bacteria and their bactericidal effectivity declined with the decrease of the cationic surfactant content in the mixtures. The hemolytic activity and cytotoxicity of these catanionic formulations against non-tumoral (3T3, HaCaT) and tumoral (HeLa, A431) cell lines also improved by increasing the ratio of cationic surfactant in the mixture. These results indicate that the biological activity of these systems is mainly governed by the cationic charge density, which can be modulated by changing the cationic/anionic surfactant ratio in the mixtures. Remarkably, the incorporation of cholesterol in those catanionic vesicles reduces their cytotoxicity and increases the safety of future biomedical applications of these systems.
Asunto(s)
Aminoácidos/química , Cationes/química , Agregado de Proteínas , Tensoactivos/química , Aminoácidos/farmacología , Aniones/química , Antibacterianos/química , Antibacterianos/farmacología , Cationes/farmacología , Bacterias Grampositivas/efectos de los fármacos , Ácido Mirístico/química , Dispersión del Ángulo Pequeño , Tensoactivos/farmacología , Difracción de Rayos XRESUMEN
Malignant hypertension is listed among the causes of secondary thrombotic microangiopathy, but pathogenic mutations in complement genes have been reported in patients with hypertension-induced thrombotic microangiopathy. Here we investigated the frequency and severity of hypertension in 55 patients with primary atypical hemolytic uremic syndrome (aHUS). A genetic analysis was performed in all patients, and funduscopic examination was performed in all the patients with Grades 2 and 3 hypertension. A cohort of 110 patients with malignant hypertension caused by diseases other than aHUS served as control. Thirty-six patients with aHUS presented Grade 2 or Grade 3 hypertension and funduscopic examination showed malignant hypertension in 19. Genetic abnormalities in complement were found in 19 patients (37% among patients with malignant hypertension). Plasmapheresis was performed in 46 patients and 26 received eculizumab. Renal and hematological responses were significantly lower after plasmapheresis (24%) than after eculizumab (81%). Renal survival was significantly higher in patients treated with eculizumab (85% at one, three and five years) compared to patients who did not receive this treatment (54%, 46% and 41%), respectively. Response to eculizumab was independent of hypertension severity and the presence of complement genetic abnormalities. Among patients with malignant hypertension caused by other diseases the prevalence of thrombotic microangiopathy was very low (5%). Thus, severe and malignant hypertension are common among patients with aHUS and eculizumab treatment leads to a higher renal survival when compared to plasmapheresis. However, thrombotic microangiopathy is uncommon among patients presenting with malignant hypertension caused by diseases other than aHUS.
Asunto(s)
Síndrome Hemolítico Urémico Atípico/complicaciones , Proteínas del Sistema Complemento/genética , Hipertensión Maligna/epidemiología , Índice de Severidad de la Enfermedad , Adulto , Anticuerpos Monoclonales Humanizados/uso terapéutico , Síndrome Hemolítico Urémico Atípico/genética , Síndrome Hemolítico Urémico Atípico/terapia , Inactivadores del Complemento/uso terapéutico , Femenino , Humanos , Hipertensión Maligna/diagnóstico , Hipertensión Maligna/genética , Hipertensión Maligna/terapia , Incidencia , Masculino , Persona de Mediana Edad , Plasmaféresis , Estudios Retrospectivos , Adulto JovenRESUMEN
Imidazolium-based ionic liquids (ILs) containing cleavable carbonate linkages, 1-alkyloxycarbonyloxyethyl-3-methylimidazolium chlorides with alkyl chains of 10, 12, and 14 carbon atoms, were synthesized, and their self-assembly behavior and antimicrobial activity were investigated. Differential scanning calorimetry and polarized optical microscopy studies reveal that carbonate-functionalized ILs form stable thermotropic smectic liquid-crystalline phases over a wide range of temperature. The surface activity and aggregation behavior of these new ILs were investigated by tensiometry, conductometry, potentiometry, and spectrofluorimetry. The size of aggregates was examined by dynamic light scattering (DLS). Carbonate-functionalized ILs display a higher adsorption efficiency and a lower critical micelle concentration (cmc) than simple alkyl-chain-substituted ILs. The insertion of a carbonate ester moiety in the alkyl side chain favors adsorption at the air-water interface and micellization in the bulk solution when compared to nonfunctionalized ILs. DLS measurements show that small micellelike aggregates are spontaneously formed above the cmc. Furthermore, carbonate-functionalized ILs were examined for their antimicrobial activity against a panel of clinically relevant microorganisms. Biological activity was found to increase with hydrophobicity. The presence of a carbonate ester moiety significantly enhances the antimicrobial efficiency as compared to nonfunctionalized ILs, with the susceptibility of Staphylococcus sp. toward the action of these compounds being particularly remarkable. It has been demonstrated that the functionalization of the alkyl side chain of the imidazolium salts can not only modify the aggregation behavior but also lead to differences in both efficiency and the spectrum of antimicrobial activity of amphiphilic ILs.
Asunto(s)
Líquidos Iónicos , Antibacterianos , Carbonatos , Interacciones Hidrofóbicas e HidrofílicasRESUMEN
INTRODUCTION: Extended-spectrum beta-lactamase (ESBL) producing bacteria are infrequent pathogens of urinary tract infections in children. The objective of our study was to investigate the presence, clinically associated characteristics and risk factors for acquisition of urinary tract infection/acute pyelonephritis (UTI/APN) in hospitalised children <2years old caused by community-acquired ESBL. METHODS: A case-control study in a second level community hospital in Spain, in which 537 episodes of UTI/APN were investigated in a retrospective study between November 2005 and August 2014. Cases were patients with ESBL strains. For each case, four ESBL-negative controls were selected. A questionnaire with the variables of interest was completed for every patient, and the groups were compared. RESULTS: ESBL-positive strains were found in 19 (3,5%) cultures. Of these 16 (84%) were Escherichia coli. Vesicoureteral reflux (VUR) of any grade was more frequent in the ESBL group (60 vs. 29%), although without statistical significance. Relapses were more frequent in the ESBL group (42% vs. 18%) (P=.029; OR=3.2; 95%CI: 1.09-9.5). The prevalence of UTI/APN due to ESBL-positive strains increased slightly from 2.7% in the period 2005-2009 to 4.4% in the period 2010-2014. CONCLUSIONS: ESBL UTI/APN were associated with more frequent relapses. VUR of any grade was twice more frequent in the ESBL group. Piperacillin/tazobactam, fosfomycin and meropenem showed an excellent activity. Aminoglycosides may be a therapeutic option, and in our patients gentamicin was the antibiotic most used.
Asunto(s)
Proteínas Bacterianas/análisis , Infecciones Comunitarias Adquiridas/epidemiología , Infecciones Urinarias/epidemiología , Resistencia betalactámica , beta-Lactamasas/análisis , Estudios de Casos y Controles , Infecciones Comunitarias Adquiridas/microbiología , Comorbilidad , Escherichia coli/enzimología , Escherichia coli/aislamiento & purificación , Infecciones por Escherichia coli/epidemiología , Infecciones por Escherichia coli/microbiología , Femenino , Fiebre/etiología , Hospitales Comunitarios/estadística & datos numéricos , Humanos , Lactante , Pacientes Internos , Masculino , Pielonefritis/epidemiología , Pielonefritis/microbiología , Estudios Retrospectivos , Factores de Riesgo , España/epidemiología , Encuestas y Cuestionarios , Infecciones Urinarias/microbiología , Reflujo Vesicoureteral/epidemiologíaRESUMEN
OBJECTIVES: The 2009-2010 influenza A (H1N1pdm09) pandemic caused substantial morbidity and mortality among young patients; however, mortality estimates have been confounded by regional differences in eligibility criteria and inclusion of selected populations. In 2013-2014, H1N1pdm09 became North America's dominant seasonal influenza strain. Our objective was to compare the baseline characteristics, resources, and treatments with outcomes among critically ill patients with influenza A (H1N1pdm09) in Mexican and Canadian hospitals in 2014 using consistent eligibility criteria. DESIGN: Observational study and a survey of available healthcare setting resources. SETTING: Twenty-one hospitals, 13 in Mexico and eight in Canada. PATIENTS: Critically ill patients with confirmed H1N1pdm09 during 2013-2014 influenza season. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The main outcome measures were 90-day mortality and independent predictors of mortality. Among 165 adult patients with H1N1pdm09-related critical illness between September 2013 and March 2014, mean age was 48.3 years, 64% were males, and nearly all influenza was community acquired. Patients were severely hypoxic (median PaO2-to-FIO2 ratio, 83 mm Hg), 97% received mechanical ventilation, with mean positive end-expiratory pressure of 14 cm H2O at the onset of critical illness and 26.7% received rescue oxygenation therapy with prone ventilation, extracorporeal life support, high-frequency oscillatory ventilation, or inhaled nitric oxide. At 90 days, mortality was 34.6% (13.9% in Canada vs 50.5% in Mexico, p < 0.0001). Independent predictors of mortality included lower presenting PaO2-to-FIO2 ratio (odds ratio, 0.89 per 10-point increase [95% CI, 0.80-0.99]), age (odds ratio, 1.49 per 10 yr increment [95% CI, 1.10-2.02]), and requiring critical care in Mexico (odds ratio, 7.76 [95% CI, 2.02-27.35]). ICUs in Canada generally had more beds, ventilators, healthcare personnel, and rescue oxygenation therapies. CONCLUSIONS: Influenza A (H1N1pdm09)-related critical illness still predominantly affects relatively young to middle-aged patients and is associated with severe hypoxemic respiratory failure. The local critical care system and available resources may be influential determinants of patient outcome.
Asunto(s)
Enfermedad Crítica/terapia , Subtipo H1N1 del Virus de la Influenza A , Gripe Humana/fisiopatología , Gripe Humana/terapia , Unidades de Cuidados Intensivos/estadística & datos numéricos , Corticoesteroides/economía , Corticoesteroides/uso terapéutico , Adulto , Anciano , Antivirales/economía , Antivirales/uso terapéutico , Canadá/epidemiología , Enfermedad Crítica/epidemiología , Oxigenación por Membrana Extracorpórea/economía , Oxigenación por Membrana Extracorpórea/métodos , Femenino , Gastos en Salud , Humanos , Gripe Humana/economía , Gripe Humana/epidemiología , Masculino , México/epidemiología , Persona de Mediana Edad , Respiración Artificial/economía , Respiración Artificial/métodos , Insuficiencia Respiratoria/fisiopatología , Insuficiencia Respiratoria/terapiaRESUMEN
Mixtures of natural and biodegradable surfactants and ionic polysaccharides have attracted considerable research interest in recent years because they prosper as antimicrobial materials for medical applications. In the present work, interactions between the lysine-derived biocompatible cationic surfactant N(ε)-myristoyl-lysine methyl ester, abbreviated as MKM, and the sodium salt of hyaluronic acid (NaHA) are investigated in aqueous media by potentiometric titrations using the surfactant-sensitive electrode and pyrene-based fluorescence spectroscopy. The critical micelle concentration in pure surfactant solutions and the critical association concentration in the presence of NaHA are determined based on their dependence on the added electrolyte (NaCl) concentration. The equilibrium between the protonated (charged) and deprotonated (neutral) forms of MKM is proposed to explain the anomalous binding isotherms observed in the presence of the polyelectrolyte. The explanation is supported by theoretical model calculations of the mixed-micelle equilibrium and the competitive binding of the two MKM forms to the surface of the electrode membrane. It is suggested that the presence of even small amounts of the deprotonated form can strongly influence the measured electrode response. Such ionic-nonionic surfactant mixtures are a special case of mixed surfactant systems where the amount of the nonionic component cannot be varied independently as was the case for some of the earlier studies.
Asunto(s)
Materiales Biocompatibles/química , Ácido Hialurónico/química , Lisina/química , Tensoactivos/química , Cationes , Modelos Teóricos , Espectrometría de FluorescenciaRESUMEN
A chiral selection process in a self-assembled soft monolayer of an achiral amphiphile as a consequence of its interaction with chiral species dissolved in the aqueous subphase, is reported. The extent of the chiral selection is statistically measured in terms of the enantiomorphic excess of self-assembled submillimeter domains endowed with well-defined orientational chirality that is unambiguously resolved using optical microscopy. Our results show that the emergence of chirality is mediated by electrostatic interactions and significantly enhanced by hydrophobic effects. This chiral chemical effect can be suppressed and even reversed by opposing a macroscopic physical influence, such as vortical stirring. This result gives evidence for the crucial role of hydrodynamic effects in supramolecular aggregation.
Asunto(s)
Modelos Moleculares , Estereoisomerismo , Modelos Químicos , Fenómenos Físicos , Electricidad EstáticaRESUMEN
The phase behavior of an ad hoc synthesized surfactant, sodium 8-hexadecylsulfate (8-SHS), and its mixtures with didecyldimethylammonium bromide (DiDAB) in water is reported. We dealt with dilute concentration regimes, at a total surfactant content of <30 mmol kg(-1) where vesicular aggregates may be formed. The high synergistic behavior of such catanionic mixtures is concomitant with strongly negative interaction parameters, ß (≈-18 kBT), significant gain in the free energy of association, ΔGagg, and much lower association concentration compared to the pure surfactants. Vesicle size and ζ-potential depend on the mixture composition. Hydrodynamic diameters increase by progressive addition of oppositely charged surfactants to the one in excess. Counter-intuitively, the ζ-potential becomes more negative at DiDAB molar fractions close to 0.2. The same holds in the reverse case, the ζ-potential becomes more positive after small additions of 8-SHS; anyhow, the effect is more significant in anionic-rich mixtures. This phenomenon was explained by assuming a significant release of counterions and an asymmetric distribution of the two surfactants in the inner and outer vesicle leaflets. The equimolar mixtures form a cubic phase rather than the expected lamellar one. The effect of NaBr concentration on the stability of catanionic vesicles was also investigated. At high NaBr concentrations, all systems are destabilized. For DiDAB-rich vesicles, flocculation is observed, while for 8-SHS-rich ones, lamellar domains are formed at the bottom of the samples. The role played by NaBr depends on whether it is added before or after mixing the surfactants. In particular, preformed catanionic vesicles show a great kinetic stability towards addition of NaBr compared to those obtained by other procedures.
RESUMEN
In the current study, a smart release system responsive to temperature was developed to improve the efficiency of tetracycline (TC) in antibacterial therapy. The nanovesicles designed consist of a non-ionic surfactant, SPAN60, cholesterol and a phase change material (PCM) as a thermoresponsive gating material. Niosomes were prepared using an increasing amount of PCM and characterized in terms of size, zeta potential, colloidal stability and thermoresponsive properties. The vesicles that developed were homogenous in size, had good biocompatibility and stability for up to 3 months and demonstrated thermoresponsive behavior. A low drug leakage was observed at 37 °C, while a rapid release occurred at 42 °C, due to the faster diffusion rate of the drug trough the melted PCM. This controllable drug release capacity allows us to avoid premature drug release, minimizing unwanted and toxic effects and ensuring a long retention time in the nanodevice so that it reaches the infected sites. In addition, TC-loaded niosomes were screened to investigate their antibacterial activity against various Gram-positive and Gram-negative bacteria by minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) assays. An interesting temperature-dependent antibacterial activity was observed against some bacterial strains: the niosomes activity against S. epidermis, for example, was improved by the temperature increase, as suggested by a reduction in MIC values from 112.81 to 14.10 µM observed at 37 and 42 °C, respectively. Taken together, the thermoresponsive platform developed allows us to use lower antibiotic amounts while ensuring therapeutic efficacy and, so, will advance the development of a novel antibacterial agent in clinical practice.
RESUMEN
To explore preoperative and operative risk factors for red blood cell (RBC) transfusion requirements during liver transplantation (LT) and up to 24 h afterwards. We evaluated the associations between risk factors and units of RBC transfused in 176 LT patients using a log-binomial regression model. Relative risk was adjusted for age, sex, and the model for end-stage liver disease score (MELD) (adjustment 1) and baseline hemoglobin concentration (adjustment 2). Forty-six patients (26.14%) did not receive transfusion. Grafts from cardiac-death donors were used in 32.61% and 31.54% of non-transfused and transfused patients, respectively. The transfused group required more reoperation for bleeding (P = 0.035), longer mechanical ventilation after LT (P < 0.001), and longer ICU length of stay (P < 0.001). MELD and hemoglobin concentrations determined RBC requirements. For each unit of increase in the MELD score, 2% more RBC units were transfused, and non-transfusion was 0.83-fold less likely. For each 10-g/L higher hemoglobin concentration at baseline, 16% less RBC transfused, and non-transfusion was 1.95-fold more likely. Ascites was associated with 26% more RBC transfusions. With an increase of 2 mm from the baseline in the A10FIBTEM measurement of maximum clot firmness, non-transfusion was 1.14-fold more likely. A 10-min longer cold ischemia time was associated with 1% more RBC units transfused, and the presence of post-reperfusion syndrome with 45% more RBC units. We conclude that preoperative correction of anemia should be included in LT. An intervention to prevent severe hypotension and fibrinolysis during graft reperfusion should be explored.Trial register: European Clinical Trials Database (EudraCT 2018-002,510-13) and ClinicalTrials.gov (NCT01539057).
Asunto(s)
Trasplante de Hígado , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Transfusión Sanguínea , Enfermedad Hepática en Estado Terminal/cirugía , Transfusión de Eritrocitos , Hemoglobinas/metabolismo , Hemoglobinas/análisis , Tiempo de Internación , Trasplante de Hígado/efectos adversos , Trasplante de Hígado/métodos , Factores de RiesgoRESUMEN
Objectives: Preeclampsia (PE) is a complication of pregnancy that might increase progeny risk of cardiovascular and metabolic problems, mainly in males. Renin angiotensin aldosterone system is known to be involved. (Pro) renin/renin receptor ((P)RR) has been shown to participate in cardiovascular pathology. The aim of this work was to evaluate (P)RR expression and function upon cardiovascular and renal tissues from PE dams' offspring. Materials and Methods: We used offspring from normal pregnant and preeclamptic rats, evaluating body, heart, aorta and kidney weight, length, and blood pressure along 3 months after birth. Subsets of animals received handle region peptide (HRP) (0.2 mg/Kg, sc). Another group received vehicle. Animals were sacrificed at first, second, and third months of age, tissues were extracted and processed for immunoblot to detect (P)RR, PLZF, ß-catenin, DVL-1, and PKCα. (P)RR and PLZF were also measured by RT-PCR. Results: We found that offspring developed hypertension. Male descendants remained hypertensive throughout the whole experiment. Female animals tended to recover at second month and returned to normal blood pressure at third month. HRP treatment diminished hypertension in both male and female animals. Morphological evaluations showed changes in heart, aorta, and kidney weight, and HRP reverted this effect. Finally, we found that (P)RR, PLZF, and canonical WNT transduction pathway molecules were stimulated by PE, and HRP treatment abolished this increase. Conclusion: These findings suggest that PE can induce hypertension in offspring, and (P)RR seems to play an important role through the canonical WNT pathway and that gender seems to influence this response.
RESUMEN
Aim: The present study investigated the antimicrobial effectiveness of a rhamnolipid complexed with arginine (RLMIX_Arg) against planktonic cells and biofilms of methicillin-resistant Staphylococcus aureus (MRSA). Methodology: Susceptibility testing was performed using the Clinical & Laboratory Standards Institute protocol: M07-A10, checkerboard test, biofilm in plates and catheters and flow cytometry were used. Result: RLMIX_Arg has bactericidal and synergistic activity with oxacillin. RLMIX_Arg inhibits the formation of MRSA biofilms on plates at sub-inhibitory concentrations and has antibiofilm action against MRSA in peripheral venous catheters. Catheters impregnated with RLMIX_Arg reduce the formation of MRSA biofilms. Conclusion: RLMIX_Arg exhibits potential for application in preventing infections related to methicillin-resistant S. aureus biofilms.
[Box: see text].
Asunto(s)
Antibacterianos , Arginina , Biopelículas , Staphylococcus aureus Resistente a Meticilina , Pruebas de Sensibilidad Microbiana , Tensoactivos , Biopelículas/efectos de los fármacos , Biopelículas/crecimiento & desarrollo , Staphylococcus aureus Resistente a Meticilina/efectos de los fármacos , Arginina/farmacología , Arginina/química , Antibacterianos/farmacología , Antibacterianos/química , Humanos , Tensoactivos/farmacología , Tensoactivos/química , Glucolípidos/farmacología , Glucolípidos/química , Infecciones Estafilocócicas/microbiología , Infecciones Estafilocócicas/prevención & control , Infecciones Estafilocócicas/tratamiento farmacológico , Oxacilina/farmacología , Sinergismo FarmacológicoRESUMEN
PURPOSE: HER2-targeted therapies have dramatically improved outcomes of patients with HER2-positive breast cancer (BC), as demonstrated in neoadjuvant trials. This study aims to provide real-world evidence on the use and effectiveness of combined pertuzumab, trastuzumab and chemotherapy (CT) in early-stage HER2-positive BC. METHODS: A retrospective, multicentre study was conducted on patients diagnosed with HER2-positive early BC treated with neoadjuvant pertuzumab and trastuzumab plus CT at 13 Spanish sites. The primary endpoint was pathological complete response (pCR). RESULTS: A total of 310 patients were included. Pertuzumab and trastuzumab were combined with anthracyclines and taxanes, carboplatin and docetaxel, and taxane-based CT in 77.1%, 16.5%, and 6.5% of patients, respectively. Overall, the pCR rate was 62.2%. The pCR was higher amongst patients with hormone receptor-negative tumours and with tumours expressing higher levels of Ki-67 (> 20%). After postoperative adjuvant treatment, 13.9% of patients relapsed. Those patients who did not achieve pCR, with tumours at advanced stages (III), and with node-positive disease were more likely to experience distant relapse. Median overall survival (OS) and distant disease-free survival (D-DFS) were not reached at the study end. The estimated mean OS and D-DFS times were 7.5 (95% CI 7.3-7.7) and 7.3 (95% CI 7.1-7.5) years, respectively (both were significantly longer amongst patients who achieved pCR). Grade 3-4 anti-HER2 related toxicities were reported in six (1.9%) patients. CONCLUSION: Neoadjuvant pertuzumab and trastuzumab plus CT achieve high pCR rates in real-life patients with HER2-positive early BC, showing an acceptable safety profile. Innovative adjuvant strategies are essential in patients at high risk of distant disease recurrence.
Asunto(s)
Anticuerpos Monoclonales Humanizados , Protocolos de Quimioterapia Combinada Antineoplásica , Neoplasias de la Mama , Terapia Neoadyuvante , Receptor ErbB-2 , Trastuzumab , Humanos , Femenino , Neoplasias de la Mama/tratamiento farmacológico , Neoplasias de la Mama/patología , Neoplasias de la Mama/metabolismo , Trastuzumab/uso terapéutico , Trastuzumab/administración & dosificación , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Persona de Mediana Edad , Estudios Retrospectivos , Receptor ErbB-2/metabolismo , Anticuerpos Monoclonales Humanizados/uso terapéutico , Anticuerpos Monoclonales Humanizados/administración & dosificación , Adulto , Anciano , Carboplatino/administración & dosificación , Carboplatino/uso terapéutico , Taxoides/administración & dosificación , Taxoides/uso terapéutico , Docetaxel/administración & dosificación , Docetaxel/uso terapéutico , Estadificación de NeoplasiasRESUMEN
BACKGROUND AND OBJECTIVE: Reproductive history influences breast cancer risk. We analysed its association with tumour subtype and survival in premenopausal women. PATIENTS AND METHODS: Retrospective, observational study of premenopausal women with stage I-III breast carcinoma in the last 20 years. Review of reproductive history, clinical data, and treatments in health records. RESULTS: In 661 premenopausal women (32.40% of 1377 total cases), median age was 47 years (19-53), menarche 12 (7-17), first delivery 28 (16-41) and number of deliveries 2 (0-9). One hundred and eleven (18.20%) were nulliparous. Three hundred and fifty-nine (58.80%) used natural lactation, with a median duration of 6 months. Anovulatory drugs were used by 271 (44.40%), with a median duration of 36 months. Associations were found between menarche <10 years and lower risk of luminal subtype (OR: 0.52, 95% CI: 0.28-0.94; P=.03), between menarche >11 years and lower risk of HER2 subtype (OR: 0.50, 95% CI: 0.26-0.97; P=.04) and between first birth >30 years and lower risk of triple negative subtype (OR: 0.40, 95% CI: 0.17-0.93; P=.03). The 20-year overall and disease-free survival probabilities were 0.80 (95% CI: 0.71-0.90) and 0.72 (95% CI: 0.64-0.79) respectively. Patients with ≥1 delivery had better overall survival than nulliparous patients (HR: 0.51, 95% CI: 0.27-0.96, P=.04). CONCLUSIONS: The findings suggest an association between age at menarche and age at first delivery and breast cancer subtype. Nulliparity is associated with worse survival.