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BACKGROUND: Continence issues due to organic causes including previous colorectal surgery or neurological issues might benefit from Transanal irrigation (TAI) that proved to be highly effective but with a number of limitations including a relatively high discontinuation rates. Our study was aimed at evaluating the efficacy of an advanced protocol tailored to each patient to prevent dropout and increase satisfaction, independence, and quality of life. MATERIALS AND METHODS: This was a prospective, interventional, multicenter, nonrandomized study involving children aged 4-18 years with bowel dysfunction unresponsive to conventional treatments who required TAI. TAI was performed in accordance to the best standards of care with a total irrigation volume that was determined based on low emission X-Ray barium enemas performed at the very beginning of the study. All patients underwent training and assessments of continence, patients' perspectives and quality of life were performed at different timepoints from enrollment (T0) up to 6 months since TAI was introduced (T3). RESULTS: A total of 78 patients were enrolled. Male to female ratio was 1.4:1. Mean age at enrollment was 106.1 ± 42.8 months. Discontinuation was reported by 3 patients (3.8 %). Continence, satisfaction and a number of other outcome measures increased from baseline (T0) to the last visit (T3). In particular, mean Rintala total score increased linearly from 7.8 to 14.8 during the study period (T0 to T3 timepoints). On a multivariate analysis, the only parameter that proved to be inversely associated with continence as well as with other outcome measures was the use of laxatives at enrollment and during the study. CONCLUSIONS: This study has demonstrated the high efficacy of this innovative patient-tailored TAI protocol across all assessed scores. Of note, given the negative impact of laxatives, our findings suggest limiting their use in this patient population to further increase the efficacy of the procedure.
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Canal Anal , Incontinencia Fecal , Satisfacción del Paciente , Calidad de Vida , Irrigación Terapéutica , Humanos , Niño , Masculino , Femenino , Estudios Prospectivos , Preescolar , Irrigación Terapéutica/métodos , Adolescente , Incontinencia Fecal/terapia , Resultado del Tratamiento , Educación del Paciente como Asunto/métodosRESUMEN
OBJECTIVE: Coronavirus disease 2019 (COVID-19) is an emerging infectious disease that was first reported in Wuhan, China, and has subsequently spread worldwide. An association between increased venous thromboembolism in patients with pneumonia-related to COVID-19 has not yet been well described. PATIENTS AND METHODS: We aimed to illustrate cases of pulmonary thromboembolism in patients with acute respiratory distress syndrome related to COVID-19 treated in our intensive care unit. The medical records of patients affected by COVID-19 with acute respiratory distress syndrome in our institute from 1/3/2020 to 31/3/2020 were retrospectively reviewed. RESULTS: Our center registered a high prevalence of thromboembolic events among 62 patients affected by acute respiratory distress syndrome related to COVID-19 despite a regular antithrombotic prophylaxis. Out of these, 32 patients were transferred to other hospitals, and 30 were treated in our center. Venous thromboembolism was registered in 12 (19.3%) cases. In particular, 11 diagnoses of pulmonary embolism and 1 diagnosis of deep vein thrombosis were formulated. We described a case series of venous thromboembolism in nine patients treated in our Intensive Care Unit (ICU). Main pulmonary arteries were always involved in these patients. None of them died. CONCLUSIONS: In conclusion, critically ill patients with ARDS related to COVID-19 may have an increased risk of VTE that could be a leading cause of mortality. These patients require a high index of clinical suspicion and an accurate diagnostic approach, in order to immediately start an appropriate anticoagulant treatment.
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Infecciones por Coronavirus/diagnóstico , Neumonía Viral/diagnóstico , Síndrome de Dificultad Respiratoria/complicaciones , Tromboembolia Venosa/diagnóstico , Anciano , Betacoronavirus/aislamiento & purificación , COVID-19 , Infecciones por Coronavirus/complicaciones , Infecciones por Coronavirus/virología , Enfermedad Crítica , Femenino , Humanos , Unidades de Cuidados Intensivos , Italia , Masculino , Persona de Mediana Edad , Pandemias , Neumonía Viral/complicaciones , Neumonía Viral/virología , Embolia Pulmonar/complicaciones , Embolia Pulmonar/diagnóstico , Embolia Pulmonar/diagnóstico por imagen , Síndrome de Dificultad Respiratoria/diagnóstico por imagen , Estudios Retrospectivos , SARS-CoV-2 , Tomografía Computarizada por Rayos X , Tromboembolia Venosa/complicaciones , Trombosis de la Vena/complicaciones , Trombosis de la Vena/diagnósticoRESUMEN
Therapeutic monoclonal antibodies (mAbs) are highly complex proteins that must be exhaustively characterized according to the regulatory authorities' recommendations. MAbs display micro-heterogeneity mainly due to their post-translational modifications, but also to their susceptibility to chemical and physical degradations. Among these degradations, aggregation is quite frequent, initiated by protein denaturation and then dimer formation. Here, we investigated the nature and structure of the high molecular weight species (HMW) present at less than 1% in an unstressed formulated roledumab biopharmaceutical, as a model of high purity mAb. HMW species were first purified through preparative size-exclusion chromatography (SEC) and then analyzed by a combination of chromatographic methods (ion-exchange chromatography (IEX), SEC) coupled to native mass spectrometry (MS), as well as sodium dodecyl sulfate-polyacrylamide gel electrophoresis and capillary gel electrophoresis under non-reducing conditions. Both covalently and non-covalently bound dimers were identified at a proportion of 50/50. In-depth characterization of the HMW fraction by SEC and IEX hyphenated to native MS revealed the presence of three mAb dimer forms having the same mass, but differing by their charge and size. They were attributed to different compact and elongated dimers. Finally, high-resolution middle-up approaches using different enzymes (IdeS and IgdE) were performed to determine the mAb domains implicated in the dimerization. Our results revealed that the roledumab dimers were associated mainly by a single Fab-to-Fab arm-bound association.
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Anticuerpos Monoclonales , Multimerización de Proteína , Anticuerpos Monoclonales/química , Anticuerpos Monoclonales/aislamiento & purificación , Cromatografía en Gel , Cromatografía Líquida de Alta Presión , Cromatografía por Intercambio Iónico , Electroforesis Capilar , Humanos , Espectrometría de MasasRESUMEN
From January to December 2016, samples of milk and feeds of dairy cattle were monthly collected. The concentration of mycotoxins in all matrices was determined using the enzymatic immunoassay technique. The average concentration of aflatoxin B1 (AFB1), deoxynivalenol (DON) and zearalenone (ZEA) in feed was 3.01, 218.5 and 467â¯ug/kg, respectively. The average AFB1 carry-over rate was 0.84% with a variation between 0.05 to 5.93%. Particle size of the feed (Pâ¯=â¯0.030) and individual milk production (Pâ¯=â¯0.001) affected this rate. Mini-soft cheeses were produced using milk naturally contaminated with aflatoxin M1 (AFM1) as raw material to study its distribution both in whey and in cheese. The average level of AFM1 in milk was 0.014⯵g/l. None of milk samples exceeded the maximum level accepted for AFB1 by the Southern Common Market (MERCOSUR) legislation (0.5⯵g/l) and only 5.5% of samples exceeded the European Union (UE) regulations (0.05⯵g/l). After the cheese elaboration, the concentration of AFM1 was determined in whey and in cheese. The greatest proportion (60%) was detected in whey while 40% AFM1 remained in the cheese. However, the concentration of AFM1 was higher in the cheese compared to the original milk.
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A faithful characterization of nanomedicine (NM) is needed for a better understanding of their in vivo outcomes. Size and surface charge are studied with well-established methods. However, other relevant parameters for the understanding of NM behavior in vivo remain largely inaccessible. For instance, the reactive surface of nanomedicines, which are often grafted with macromolecules to decrease their recognition by the immune system, is excluded from a systematic characterization. Yet, it is known that a subtle modification of NMs' surface characteristics (grafting density, molecular architecture and conformation of macromolecules) is at the root of major changes in the presence of biological components. In this work, a method that investigates the steric hindrance properties of the NMs' surface coverage based on its capacity to exclude or allow adsorption of well-defined proteins was developed based on capillary electrophoresis. A series of proteins with different molecular weights (MW) were used as molecular probes to screen their adsorption behavior on nanoparticles bearing different molecular architectures at their surface. This novel strategy evaluating to some degree a functionality of NMs can bring additional information about their shell property and might allow for a better perception of their behavior in the presence of biological components. The developed method could discriminate nanoparticles with a high surface coverage excluding high MW proteins from nanoparticles with a low surface coverage that allowed high MW proteins to adsorb on their surface. The method has the potential for further standardization and automation for a routine use. It can be applied in quality control of NMs and to investigate interactions between proteins and NM in different situations.
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Electroforesis Capilar/métodos , Nanomedicina , Nanopartículas , Proteínas/química , Adsorción , Sondas Moleculares , Peso Molecular , Tamaño de la Partícula , Propiedades de SuperficieRESUMEN
Alzheimer's disease is a neurodegenerative disorder linked to oligomerization and fibrillization of amyloid ß peptides, with Aß1-42 being the most aggregative and neurotoxic one. We report herein the synthesis and conformational analysis of Aß1-42-amyloid related ß-hairpin peptidomimetics, built on a piperidine-pyrrolidine semi rigid ß-turn inducer and bearing two small recognition peptide sequences, designed on oligomeric and fibril structures of Aß1-42. According to these peptide sequences, a stable ß-hairpin or a dynamic equilibrium between two possible architectures was observed. These original constructs are able to greatly delay the kinetics of Aß1-42 aggregation process as demonstrated by thioflavin-T fluorescence, and transmission electron microscopy. Capillary electrophoresis indicates their ability to preserve the monomer species, inhibiting the formation of toxic oligomers. Furthermore, compounds protect against toxic effects of Aß on neuroblastoma cells even at substoichiometric concentrations. This study is the first example of acyclic small ß-hairpin mimics possessing such a highly efficient anti-aggregation activity. The protective effect is more pronounced than that observed with molecules which have undergone clinical trials. The structural elements made in this study provide valuable insights in the understanding of the aggregation process and insights to explore the design of novel acyclic ß-hairpin targeting other types of amyloid-forming proteins.
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BACKGROUND: In Germany medical students should gain proficiency and specific skills in the vaccination field. Especially important is the efficient communication of scientific results about vaccinations to the community, in order to give professional counseling with a complete overview about therapeutic options. AIM OF THE PROJECT: The aim of this project is to set up a vaccination-related curriculum in the Medical Faculty at the Ludwig-Maximilians-University in Munich. The structure of the curriculum is based on the National catalogue for competency-based learning objectives in the field of vaccination (Nationaler Kompetenzbasierter Lernzielekatalog Medizin NKLM). Through this curriculum, the students will not only acquire the classical educational skills concerning vaccination in theory and practice, but they will also learn how to become independent in the decision-making process and counseling. Moreover, the students will become aware of consequences of action related to this specific topic. METHODS: According to defined guidelines, an analysis was performed on courses, which are currently offered by the university. A separate analysis of the NKLM was carried out. Both analyses identified the active courses related to the topic of vaccination as well as the NKLM learning objectives. The match between the topics taught in current courses and the NKLM learning objectives identified gaps concerning the teaching of specific content. Courses were modified in order to implement the missing NKLM learning objectives. RESULTS: These analyses identified 24 vaccination-related courses, which are currently taught at the University. Meanwhile, 35 learning objectives on vaccination were identified in the NKLM catalogue. Four of which were identified as not yet part of the teaching program. In summary, this interdisciplinary work enabled the development of a new vaccination-related curriculum, including 35 learning objectives, which are now implemented in regular teaching courses by the Medical Faculty. CONCLUSIONS: This project successfully describes a method to develop and implement a competency-based teaching program on the topic of vaccination. Importantly, the process presented here can serve as a guide to develop and implement similar teaching programs on other subjects and Universities.
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Educación Basada en Competencias/organización & administración , Curriculum , Educación Médica/organización & administración , Docentes Médicos , Implementación de Plan de Salud/organización & administración , Vacunación , Competencia Clínica , Alemania , Humanos , Comunicación Interdisciplinaria , Colaboración IntersectorialRESUMEN
BACKGROUND: Critically ill patients suffer from physiological sleep deprivation and have reduced blood melatonin levels. This study was designed to determine whether nocturnal melatonin supplementation would reduce the need for sedation in patients with critical illness. METHODS: A single-center, double-blind randomized placebo-controlled trial was carried out from July 2007 to December 2009, in a mixed medical-surgical Intensive Care Unit of a University hospital, without any form of external funding. Of 1158 patients admitted to ICU and treated with conscious enteral sedation, 82 critically-ill with mechanical ventilation >48 hours and Simplified Acute Physiology Score II>32 points were randomized 1:1 to receive, at eight p.m. and midnight, melatonin (3+3mg) or placebo, from the third ICU day until ICU discharge. Primary outcome was total amount of enteral hydroxyzine administered. RESULTS: Melatonin treated patients received lower amount of enteral hydroxyzine. Other neurological indicators (amount of some neuroactive drugs, pain, agitation, anxiety, sleep observed by nurses, need for restraints, need for extra sedation, nurse evaluation of sedation adequacy) seemed improved, with reduced cost for neuroactive drugs. Post-traumatic stress disorder prevalence did not differ between groups, nor did ICU or hospital mortality. Study limitations include the differences between groups before intervention, the small sample size, and the single-center observation. CONCLUSION: Long-term enteral melatonin supplementation may result in a decreased need for sedation, with improved neurological indicators and cost reduction. Further multicenter evaluations are required to confirm these results with different sedation protocols.
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Sedación Consciente/métodos , Cuidados Críticos/métodos , Hipnóticos y Sedantes/uso terapéutico , Melatonina/uso terapéutico , Anciano , Enfermedad Crítica , Método Doble Ciego , Femenino , Humanos , Hidroxizina/administración & dosificación , Unidades de Cuidados Intensivos , Masculino , Persona de Mediana Edad , Respiración ArtificialRESUMEN
BACKGROUND: Heparin and its analogs, mediating their anticoagulant activity through antithrombin (AT) activation, remain largely used for the preventive and curative treatment of thrombosis. The major adverse reaction of these drugs is the bleeding risk associated with overdose. Unfractionnated heparin (UFH) can be efficiently and rapidly neutralized by protamine sulfate, but this reversal partially neutralizes low-molecular-weight heparin (LMWH) and is inefficient in reversing fondaparinux. To secure administration of AT-mediated anticoagulants and counteract bleeding disorders, we previously designed a recombinant inactive AT as an antidote to heparin derivatives. OBJECTIVES: To get around the limited production level of recombinant AT, we propose in this study an alternative strategy to produce a chemically modified inactive AT, exhibiting increased heparin affinity, as an antagonist of heparin analogs. METHODS: Plasma-derived AT was chemically modified with 2,3 butanedione, a diketone known to specifically react with the arginine side chain. The chemical reaction was conducted in the presence of heparin to preserve basic residues within the heparin binding site from modifications. RESULTS: AT treated by butanedione and selected for its high heparin affinity (AT-BD) was indeed modified on reactive Arg393 and thus exhibited decreased anticoagulant activity and increased heparin affinity. AT-BD was able to neutralize anticoagulant activity of heparin derivatives in vitro and in vivo and was devoid of intrinsic anticoagulant activity, as assessed by activated partial thromboplastin time assay. CONCLUSIONS: AT-BD appears to be as efficient as protamine to neutralize UFH in vivo but could be more largely used because it also reverses fondaparinux and LMWH.
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Anticoagulantes/química , Antitrombinas/uso terapéutico , Antagonistas de Heparina/química , Polisacáridos/antagonistas & inhibidores , Animales , Antitrombinas/química , Arginina/química , Diacetil/química , Diseño de Fármacos , Femenino , Fondaparinux , Hemorragia , Heparina/química , Humanos , Espectrometría de Masas , Ratones , Tiempo de Tromboplastina Parcial , Polisacáridos/química , Proteínas Recombinantes/química , RiesgoRESUMEN
BACKGROUND: Warfarin directly inhibits the vitamin K 2,3-epoxide reductase complex subunit 1 (VKORC1) enzyme to effect anticoagulation. VKORC1 function has historically been assessed in vitro using a dithiothreitol (DTT)-driven vitamin K 2,3-epoxide reductase (VKOR) assay. Warfarin inhibits wild-type VKORC1 function by the DTT-VKOR assay. However, VKORC1 variants with warfarin resistance-associated missense mutations often show low VKOR activities and warfarin sensitivity instead of resistance. OBJECTIVES: A cell culture-based, indirect VKOR assay was developed and characterized that accurately reports warfarin sensitivity or resistance for wild-type and variant VKORC1 proteins. METHODS: Human coagulation factor (F)IX and VKORC1 variants were coexpressed in HEK 293T cells under standardized conditions at various warfarin concentrations. Secreted FIX activity served as surrogate marker to report wild-type and variant VKORC1 inhibition by warfarin. RESULTS AND CONCLUSIONS: Warfarin dose-response curves fit to the secreted FIX activity data for coexpressed hVKORC1 wild-type, Val29Leu, Val45Ala and Leu128Arg variants. The corresponding calculated IC50 values were 24.7, 136.4, 152.0 and 1226.4 nm, respectively. Basal activities in the absence of warfarin for all VKORC1 variants were similar to that of wild-type VKORC1. Ranked IC50 values from the cell culture-based assay accurately reflect elevated warfarin dosages for patients with VKORC1 missense mutation-associated warfarin resistance.
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Anticoagulantes/farmacología , Ditiotreitol/farmacología , Errores Innatos del Metabolismo , Vitamina K Epóxido Reductasas/metabolismo , Warfarina/farmacología , Células HEK293 , Humanos , Concentración 50 Inhibidora , Mutación Missense , Fenotipo , Vitamina K Epóxido Reductasas/genéticaRESUMEN
BACKGROUND AND AIMS: Specific Suppressor of Cytokine Signaling (SOCS) members, such as SOCS7, may play a role in the development of insulin resistance (IR) owing to their ability to inhibit insulin signaling pathways. The objective was to explore the association between common variants and related haplotypes in SOCS7 gene and metabolic traits related to obesity, lipid metabolism and IR. METHODS AND RESULTS: 780 unrelated men were included in a cross-sectional study. We selected three tagged SNPs that capture 100% of SNPs with minor allele frequency ≥ 0.10. Analyses were done separately for each SNP and followed up by haplotype analysis. rs8074124C was associated with both obesity (p = 0.005) and abdominal obesity (p = 0.002) and allele C carriers showed, in comparison with TT carriers, lower BMI (p = 0.001) and waist circumference (p = 0.001). rs8074124CC- carriers showed lower fasting insulin (p = 0.017) and HOMA-IR (p = 0.018) than allele T carriers. rs12051836C was associated with hypertriglyceridemia (p = 0.009) and hypertriglyceridemic waist (p = 0.006). rs12051836CC- carriers showed lower fasting insulin (p = 0.043) and HOMA-IR (p = 0.042). Haplotype-based association analysis (rs8074124 and rs12051836 in that order) showed associations with lipid and obesity -related phenotypes, consistent with single locus analysis. Haplotype analysis also revealed association between haplotype CT and both decreased HDL-C (p = 0.026) and HDL-C (p = 0.014) as a continuous variable. CONCLUSIONS: We found, for the first time, significant associations between SOCS7 common variants and related haplotypes and obesity, IR and lipid metabolism disorders.
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Resistencia a la Insulina/genética , Metabolismo de los Lípidos/genética , Proteínas Nucleares/genética , Obesidad/genética , Proteínas Supresoras de la Señalización de Citocinas/genética , Adolescente , Adulto , Anciano , Argentina , Presión Sanguínea , Índice de Masa Corporal , Estudios Transversales , Frecuencia de los Genes , Haplotipos , Humanos , Modelos Lineales , Masculino , Persona de Mediana Edad , Obesidad/sangre , Fenotipo , Polimorfismo de Nucleótido Simple , Autoinforme , Circunferencia de la Cintura , Adulto JovenRESUMEN
We propose a concept of very specific immune-sensing platform dedicated to the quantification of biomarkers of Alzheimer disease (AD) in biological fluids. High sensitivity is required for the earliness of AD diagnostic, mainly based on clinical evaluation at present time. Accordingly, a controlled and adaptative surface functionalization of a silicon wafer with carboxylated alkyltrichlorosilane has been developed. The surface has extensively been characterized by AFM and X-ray Photoemissive Spectroscopy. The surface modification has been chemically assessed by XPS at each functionalization step. The survey spectra of silicon surface, after, 1, 3, 6 and 24 h of silanisation, highlight a significant enhancement of the functionalization efficiency upon time. The oxidation reaction has also been investigated by XPS and showed components related to the carboxylic group. AFM measurements pointed out a morphological modification consistent with a homogenous development of the carboxylic group and an almost protein monolayer on the surface. Moreover, we evaluated the biological activity of the grafted antibodies involved in (AD) biomarker detection onto this silanized surface by fluorescent microscopy. A sandwich immunoassay dedicated to the sensitive detection of one biomarker of Alzheimer disease (AD), the amyloid peptide 1-42 (Aß 1-42), was carried out. The results demonstrated that the controlled silanized surface provides a novel and viable way to detect biomarkers with high specificity and open the route to an original development of immune-sensing applications on such surfaces.
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Enfermedad de Alzheimer/diagnóstico , Enfermedad de Alzheimer/metabolismo , Péptidos beta-Amiloides/análisis , Técnicas Biosensibles/instrumentación , Inmunoensayo/instrumentación , Fragmentos de Péptidos/análisis , Biomarcadores/análisis , Diseño de Equipo , Análisis de Falla de Equipo , Humanos , Reproducibilidad de los Resultados , Sensibilidad y EspecificidadAsunto(s)
Enfermedad de Alzheimer/tratamiento farmacológico , Péptidos beta-Amiloides/química , Cianoacrilatos/química , Nanopartículas/química , Polietilenglicoles/química , Cianoacrilatos/uso terapéutico , Electroforesis Capilar , Humanos , Cinética , Nanopartículas/uso terapéutico , Polietilenglicoles/uso terapéuticoRESUMEN
We investigated the mechanisms involved in the retention of various peptides on a stationary phase embedded with a quaternary ammonium group (BS C23), by high-performance liquid chromatography. This was compared with peptide retention on a conventional reversed-phase C18 (RP C18) column under isocratic conditions, to understand better the various mechanisms involved. Chromatographic characterization of the two stationary phases with "model" compounds showed that BS C23 is less hydrophobic than RP C18 and induces electrostatic interaction (attraction or repulsion) with ionized compounds. If reversed-phase partitioning was the predominant retention phenomenon, for both stationary phases, the retention mechanisms in BS C23 provided different selectivity to that of RP C18. Electrostatic attraction or repulsion was clearly observed between peptides and the permanent positively charged group embedded in BS C23 depending on the pH. For most of the peptides, a weak anion-exchange mechanism was observed on the quaternary ammonium-embedded stationary phase if mobile phases at neutral pH and low ionic strengths were employed.
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Cromatografía Liquida/métodos , Modelos Químicos , Péptidos/aislamiento & purificación , Compuestos de Amonio Cuaternario/química , Fenómenos Químicos , Concentración de Iones de Hidrógeno , Interacciones Hidrofóbicas e Hidrofílicas , Concentración Osmolar , Mapeo Peptídico , Electricidad EstáticaRESUMEN
Intensive Care Unit (ICU) patients almost uniformly suffer from sleep disruption. Even though the role of sleep disturbances is not still adequately understood, they may be related to metabolic, immune, neurological and respiratory dysfunction and could worsen the quality of life after discharge. A harsh ICU environment, underlying disease, mechanical ventilation, pain and drugs are the main reasons that underlie sleep disruption in the critically ill. Polysomnography is the gold standard in evaluating sleep, but it is not feasible in clinical practice; therefore, other objective (bispectral index score [BIS] and actigraphy) and subjective (nurse and patient assessment) methods have been proposed, but their adequacy in ICU patients is not clear. Frequent evaluation of neurological status with validated tools is necessary to avoid excessive or prolonged sedation in order to better titrate patient-focused therapy. Hypnotic agents like benzodiazepines can increase total sleep time, but they alter the physiological progression of sleep phases, and decrease the time spent in the most restorative phases compared to the phases normally mediated by melatonin; melatonin production is decreased in critically ill patients, and as such, exogenous melatonin supplementation may improve sleep quality. Sleep disruption and the development of delirium are frequently related, both because of sleep scarcity and inappropriate dosing with sedatives. Delirium is strongly related to increased ICU morbidity and mortality, thus the resolution of sleep disruption could significantly contribute to improved ICU outcomes. An early evaluation of delirium is strongly recommended because of the potential to resolve the underlying causes or to begin an appropriate therapy. Further studies are needed on the effects of strategies to promote sleep and on the evaluation of better sleep in clinical outcomes, particularly on the development of delirium.
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Delirio , Unidades de Cuidados Intensivos , Trastornos del Sueño-Vigilia , Enfermedad Crítica , Delirio/etiología , Delirio/prevención & control , Humanos , Trastornos del Sueño-Vigilia/etiología , Trastornos del Sueño-Vigilia/prevención & controlRESUMEN
A simple and rapid capillary zone electrophoresis (CZE) method with UV detection has been developed for the determination of famotidine and its potential impurities in pharmaceutical formulations. The electrophoretic separation of these compounds was performed using a fused silica capillary and 37.5mmolL(-1) phosphate buffer pH 3.5 as the electrolyte. Under the optimised conditions, six impurities could be resolved from the famotidine peak in less than 7min. The calibration curves obtained for the seven compounds were linear over the concentration range investigated (from 1.5 to 78.5microg mL(-1)). The intra- and inter-day relative standard deviations for the migration times and corrected peak areas were less than 2% and 5%, respectively. The detection limits were found to be 0.09microg mL(-1) for famotidine, and from 0.1 to 0.62microg mL(-1) depending on the impurities. The method has been successfully applied to the determination of famotidine in commercial dosage forms.
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Electroforesis Capilar/métodos , Famotidina/análisis , Calibración , Estándares de Referencia , Reproducibilidad de los Resultados , Sensibilidad y EspecificidadRESUMEN
Retention behaviour of biological peptides was investigated on a stationary phase bearing an embedded quaternary ammonium group in a C21 alkyl chain by both high-performance liquid chromatography (HPLC) and capillary electrochromatography (CEC). In HPLC experiments, variation of acetonitrile (ACN) content in the mobile phase showed that peptides are mainly separated by RP mechanism. The weak or negative retention factors observed as compared to C18 silica stationary phase suggested the involvement of an electrostatic repulsion phenomenon in acidic conditions. Comparison of HPLC and CEC studies indicated that (i) ion-exclusion phenomenon is more pronounced in HPLC and (ii) higher ACN percentage in mobile phase induce for some peptides an increase of retention in CEC, pointing out the existence of mechanisms of retention other than partitioning mainly involved in chromatographic process. This comparative study demonstrated the critical role of electric field on peptide retention in CEC and supports the solvatation model of hydrolytic pillow proposed by Szumski and Buszewski for CEC using mixed mode stationary phase in CEC.
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Electrocromatografía Capilar/métodos , Cromatografía Líquida de Alta Presión/métodos , Péptidos/aislamiento & purificación , Angiotensinógeno/aislamiento & purificación , Electrocromatografía Capilar/instrumentación , Cromatografía Líquida de Alta Presión/instrumentación , Eledoisina/aislamiento & purificación , Factor de Crecimiento Epidérmico/aislamiento & purificación , Gastrinas/aislamiento & purificaciónRESUMEN
Multiple clinical and physiopathological studies as well as genetic analysis, suggest that diabetic retinopathy (DR) is a consequent of interactions between environmental factors, especially hyperglycaemia, and several genetic factors. The genes of aldose reductase (AR), inducible nitric oxide synthase (NOS2A), endothelial nitric oxide synthase (NOS3), vascular endothelial growth factor (VEGF), pigmented epithelium-derived factor (PEDF), protein kinase C-beta (PKC-beta) and receptor for advanced glycation end products (RAGE) implicated in the pathogenesis of DR. The only genetic marker associated with risk of DR in several studies is a microsatellite (A-C)n at 5'end of AR. The synergistic combination of conventional approaches (e.g. candidate gene association studies) with new emerging technologies (e.g. biochips) will be a key factor in the elucidation of the genetic aspects of DR.
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Retinopatía Diabética/genética , Aldehído Reductasa/genética , Predisposición Genética a la Enfermedad/genética , Humanos , Óxido Nítrico Sintasa/genética , Óxido Nítrico Sintasa de Tipo II , Óxido Nítrico Sintasa de Tipo III , Factor A de Crecimiento Endotelial Vascular/genéticaRESUMEN
OBJECTIVES: To investigate if a dipeptide made of glutamine and alanine is able to contribute to the recovery from insulin-induced hypoglycaemia in type 1 diabetes. RESEARCH DESIGN AND METHODS: Fifteen adult type 1 patients were randomly assigned to study group (n=7): intravenous infusion of 20 g Dipeptiven in normal saline (i.e., 8 g alanine and 13 g glutamine), or control group (n=8): same infusion, normal saline only. A 150 min gradual hypoglycaemic hyperinsulinemic clamp was administered after 2 h of infusion. Counterregularory hormones, symptoms, and cognitive function (4 choice reaction test) were regularly measured during the study. RESULTS: Blood glucose and glucose infusion rates were similar in the 2 groups. Circulating levels of alanine and glutamine peaked at 90 min and remained elevated throughout the test. This was associated with significant differences in: glucagonemia 107 +/- 20 vs 58 +/- 8 pg/ml, and neuroglycopenic symptoms scores: 7 +/- 3 vs 18 +/- 13, at t 150 min, in study and control group, p<0.05. Dysautonomic symptoms, cognitive tests as well as epinephrine, norepinephrine, cortisol and growth hormone were similar between groups. CONCLUSION: Intravenous infusion of a dipeptide made of alanine and glutamine is capable to reactivate glucagon secretion during insulin-induced hypoglycaemia and to reduce hypoglycaemic symptoms.