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BACKGROUND: Increasingly, circulating tumor DNA (ctDNA) is proposed as a tool for minimal residual disease (MRD) assessment. Digital PCR (dPCR) offers low analysis costs and turnaround times of less than a day, making it ripe for clinical implementation. Here, we used tumor-informed dPCR for ctDNA detection in a large colorectal cancer (CRC) cohort to evaluate the potential for post-operative risk assessment and serial monitoring, and how the metastatic site may impact ctDNA detection. Additionally, we assessed how altering the ctDNA-calling algorithm could customize performance for different clinical settings. PATIENTS AND METHODS: Stage II-III CRC patients (N = 851) treated with a curative intent were recruited. Based on whole-exome sequencing on matched tumor and germline DNA, a mutational target was selected for dPCR analysis. Plasma samples (8 ml) were collected within 60 days after operation and-for a patient subset (n = 246)-every 3-4 months for up to 36 months. Single-target dPCR was used for ctDNA detection. RESULTS: Both post-operative and serial ctDNA detection were prognostic of recurrence [hazard ratio (HR) = 11.3, 95% confidence interval (CI) 7.8-16.4, P < 0.001; HR = 30.7, 95% CI 20.2-46.7, P < 0.001], with a cumulative ctDNA detection rate of 87% at the end of sample collection in recurrence patients. The ctDNA growth rate was prognostic of survival (HR = 2.6, 95% CI 1.5-4.4, P = 0.001). In recurrence patients, post-operative ctDNA detection was challenging for lung metastases (4/21 detected) and peritoneal metastases (2/10 detected). By modifying the cut-off for calling a sample ctDNA positive, we were able to adjust the sensitivity and specificity of our test for different clinical contexts. CONCLUSIONS: The presented results from 851 stage II-III CRC patients demonstrate that our personalized dPCR approach effectively detects MRD after operation and shows promise for serial ctDNA detection for recurrence surveillance. The ability to adjust sensitivity and specificity shows exciting potential to customize the ctDNA caller for specific clinical settings.
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ADN Tumoral Circulante , Neoplasias Colorrectales , Humanos , ADN Tumoral Circulante/genética , ADN de Neoplasias/genética , Algoritmos , Neoplasias Colorrectales/diagnóstico , Neoplasias Colorrectales/genética , Dinamarca , Biomarcadores de Tumor/genética , Recurrencia Local de NeoplasiaRESUMEN
BACKGROUND: Although cardiac autonomic modulation has been studied in several respiratory diseases, the evidence is limited on lung transplantation, particularly on its acute and chronic effects. Thus, we aimed to evaluate cardiac autonomic modulation before and after bilateral lung transplantation (BLT) through a prospective study on patients enrolled while awaiting transplant. METHODS: Twenty-two patients on the waiting list for lung transplantation (11 women, age 33 [24-51] years) were enrolled in a prospective study at Ospedale Maggiore Policlinico Hospital in Milan, Italy. To evaluate cardiac autonomic modulation, ten minutes ECG and respiration were recorded at different time points before (T0) and 15 days (T1) and 6 months (T2) after bilateral lung transplantation. As to the analysis of cardiac autonomic modulation, heart rate variability (HRV) was assessed using spectral and symbolic analysis. Entropy-derived measures were used to evaluate complexity of cardiac autonomic modulation. Comparisons of autonomic indices at different time points were performed. RESULTS: BLT reduced HRV total power, HRV complexity and vagal modulation, while it increased sympathetic modulation in the acute phase (T1) compared to baseline (T0). The HRV alterations remained stable after 6 months (T2). CONCLUSION: BLT reduced global variability and complexity of cardiac autonomic modulation in acute phases, and these alterations remain stable after 6 months from surgery. After BLT, a sympathetic predominance and a vagal withdrawal could be a characteristic autonomic pattern in this population.
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Sistema Nervioso Autónomo/fisiopatología , Frecuencia Cardíaca , Corazón/inervación , Enfermedades Pulmonares/cirugía , Trasplante de Pulmón , Pulmón/cirugía , Respiración , Adulto , Electrocardiografía , Femenino , Humanos , Pulmón/fisiopatología , Enfermedades Pulmonares/diagnóstico , Enfermedades Pulmonares/fisiopatología , Trasplante de Pulmón/efectos adversos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Factores de Tiempo , Resultado del Tratamiento , Adulto JovenRESUMEN
In reconstructing the common evolutionary history of hosts and parasites, the current method of choice is the phylogenetic tree reconciliation. In this model, we are given a host tree H, a parasite tree P, and a function [Formula: see text] mapping the leaves of P to the leaves of H and the goal is to find, under some biologically motivated constraints, a reconciliation, that is a function from the vertices of P to the vertices of H that respects [Formula: see text] and allows the identification of biological events such as co-speciation, duplication and host switch. The maximum co-divergence problem consists in finding the maximum number of co-speciations in a reconciliation. This problem is NP-hard for arbitrary phylogenetic trees and no approximation algorithm is known. In this paper we consider the influence of tree topology on the maximum co-divergence problem. In particular we focus on a particular tree structure, namely caterpillar, and show that-in this case-the heuristics that are mostly used in the literature provide solutions that can be arbitrarily far from the optimal value. Then, we prove that finding the max co-divergence is equivalent to compute the maximum length of a subsequence with certain properties of a given permutation. This equivalence leads to two consequences: (1) it shows that we can compute efficiently in polynomial time the optimal time-feasible reconciliation and (2) it can be used to understand how much the tree topology influences the value of the maximum number of co-speciations.
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Algoritmos , Biología Computacional/métodos , Evolución Molecular , Modelos Genéticos , Filogenia , Animales , HumanosRESUMEN
INTRODUCTION: Elderly people with vitamin K antagonists (VKA) have a higher risk of potentially serious hemorrhagic complications. An education program for patients (EPP) aged > or = 75 years with VKA was set up in 2008 in a French geriatric hospital. It includes individual and group sessions conducted by a nurse and a geriatrician. OBJECTIVES: The aim of this study was to assess this EPP after 5 years. Strengths, weaknesses and difficulties of implementation were highlighted, and some improvements were proposed. METHODS: This study is an external audit conducted by a pharmacist trained in EPP. Files of consecutive patients included in the program between may 2008 and March 2013 were reviewed allowing the data collection of patients characteristics and results of the different sessions. The educational objectives were assessed by the rate of correct responses to the questionnaires during the program. The results are presented taking into account the changes made during the 5 years of the program. RESULTS: One hundred forty-three patients, mean age 83.3 +/- 6.5 years, were included in the EPP. 51 sessions were conducted (2.8 patients/session on average). 58% of selected patients were hospitalized. The mean time between the start of anticoagulant treatment and the incLusion in the program was 48.9 +/- 71 months. For 95 patients (66.4%) the medication management at home required a caregiver who was present for sessions in 82 cases (57.3%). The questionnaires form and the organisation of the sessions were gradually improved between 2008 and the end of 2010. Thus, the impact of the EPP has been estimated from November 2010 to March 2013. The correct responses rates before and after the sessions were respectively: 47.8% vs 91.3% for knowledge of INR target values, 25.4% vs 91.3% for knowledge of hemorrhagic signs, 14.9% vs 87.0% for knowledge of the situations or the medications that may disturb the INR equilibrium. Furthermore, the mean number of correct responses, for the 23 patients participating in the entire program, is statistically different between the educational diagnostic and immediate evaluation (3.7/7 vs 5.4/7 p = 0.023) and no significant difference is observed between immediate and distant evaluation (5.4/7 vs 5.8/7 p = 0.720). CONCLUSION: An improvement of patient knowledge was observed with regard to the main educational objectives. Some improvements are proposed: to disseminate information to general practitioners, to add the follow up of INR values to assess an impact on anticoagulant treatment stability. Furthermore, this program is now adapted to the new oral anticoagulants. It is the role of hospital or community pharmacists to initiate and/or assess this type of EPP.
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Anticoagulantes/uso terapéutico , Educación del Paciente como Asunto , Vitamina K/antagonistas & inhibidores , Anciano , Anciano de 80 o más Años , Anticoagulantes/efectos adversos , Femenino , Humanos , Masculino , Encuestas y CuestionariosRESUMEN
Neuropsychological testing is not a luxury in the management of patients with brain tumors. Regardless of the therapeutic approach selected in each case (but, especially in the case of awake surgery), it provides information on the status of language and other cognitive functions. This information can be used preoperatively to identify eloquent areas and to provide a baseline against which further examinations can be evaluated, intraoperatively to identify eloquent areas, and post-operatively and at follow-up to ascertain the short-term and long-term consequences of surgery, as well as those of other treatments (chemotherapy and radiotherapy), and to plan and monitor rehabilitative treatments.
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Neoplasias Encefálicas/complicaciones , Trastornos del Lenguaje/etiología , Pruebas del Lenguaje , HumanosRESUMEN
INTRODUCTION: The development in an extremely short time of an efficacious and safe vaccine against the pandemi A/H1N1 virus was a challenge that involved the entire scientific community. AIMS: To assess the immunological and clinical efficacy of the new H1N1v monovalent influenza vaccine (Focetria Novartis Vaccines, Siena, Italy) in a group of health care workers (HCWs). METHODS: A total of 148 volunteer HCWs were enrolled between Mid-Novembre 2009 and December 2009. After measuring antibody titers, a single intramuscular dose of 7.5 microg of Focetria monovalent vaccine against A/H1N1/2009 influenza virus with MF59C.1 adjuvant was administered. RESULTS: Antibody titers (median value) before and after a single dose of vaccine, measured by means of standard beam-agglutination inhibition test (HAI), increased from 32 to 256 (p < 0.001). After vaccination, 79.7% of the subjects showed antibody seroconversion, and in 97.3% seroprotection was achieved. The ratio between the geometric means of antibody titers (GMTR) was 6.69. For the 3 subjects who reported symptoms of ILI (Influenza-like illness), a regular nasal-pharyngeal swab sample was taken to identify the virus type by RT-PCR, the laboratory results of tests performed on these samples were negative for pandemic A/H1N1/2009 virus. During the entire follow-up period of 6 months no severe adverse events occurred. CONCLUSIONS: The vaccine against pandemic A/H1N1/2009 virus provided protection against the virus and not only contributed to a significant immunization (according to EMEA criteria), but kept all 148 subjects under study free from A/H1N1/2009 influenza illness.
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Anticuerpos Antivirales/sangre , Personal de Salud , Inmunización , Subtipo H1N1 del Virus de la Influenza A/inmunología , Vacunas contra la Influenza , Gripe Humana/prevención & control , Adulto , Anciano , Femenino , Humanos , Vacunas contra la Influenza/efectos adversos , Masculino , Persona de Mediana Edad , Seguridad , Adulto JovenRESUMEN
OBJECTIVE: Ustekinumab (UST) is an anti-IL12/23 antibody for the treatment of Crohn's Disease (CD). The aim of this study was to compare the efficacy and safety of UST in a large population-based cohort of CD patients who failed previous treatment with other biologics. PATIENTS AND METHODS: 194 CD patients (108 males and 86 females, mean age 48 years (range 38-58 years) were retrospectively reviewed. 147 patients were already treated with anti-TNFα (75.8%), and 47 (24.2%) patients were already treated with anti-TNFα and vedolizumab. Concomitant treatment with steroids was present in 177 (91.2%) patients. RESULTS: At week 12, clinical remission was achieved in 146 (75.2%) patients. After a mean follow-up of 6 months, clinical remission was maintained in 135 (69.6%) patients; at that time, mucosal healing was assessed in 62 (31.9%) patients, and it was achieved in 33 (53.2) patients. Three (1.5%) patients were submitted to surgery. Steroid-free remission was achieved in 115 (59.3%) patients. Both serum C-Reactive Protein and Fecal Calprotectin (FC) levels were significantly reduced with respect to baseline levels during follow-up. A logistic regression, UST therapy as third-line therapy (after both anti-TNFα and vedolizumab), FC >200 µg/g, and HBI ≥8 were significantly associated with lack of remission. Adverse events occurred in 5 (2.6%) patients, and four of them required suspension of treatment. CONCLUSIONS: UST seemed to be really effective and safe in CD patients unresponsive to other biologic treatments, especially when used as second-line treatment.
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Enfermedad de Crohn/tratamiento farmacológico , Ustekinumab/uso terapéutico , Adulto , Estudios de Cohortes , Femenino , Humanos , Italia , Modelos Logísticos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Ustekinumab/administración & dosificación , Ustekinumab/efectos adversosRESUMEN
Transcranial direct current stimulation (tDCS) has been proposed as an adjuvant technique to improve functional recovery after ischaemic stroke. This study evaluated the effect of tDCS over the left frontotemporal areas in eight chronic non-fluent post-stroke aphasic patients. The protocol consisted of the assessment of picture naming (accuracy and response time) before and immediately after anodal or cathodal tDCS (2 mA, 10 minutes) and sham stimulation. Whereas anodal tDCS and sham tDCS failed to induce any changes, cathodal tDCS significantly improved the accuracy of the picture naming task by a mean of 33.6% (SEM 13.8%).
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Anomia/terapia , Afasia de Broca/terapia , Infarto Cerebral/complicaciones , Terapia por Estimulación Eléctrica/métodos , Lóbulo Frontal/fisiopatología , Lóbulo Occipital/fisiopatología , Lóbulo Temporal/fisiopatología , Anciano , Anomia/fisiopatología , Afasia de Broca/fisiopatología , Infarto Cerebral/fisiopatología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Reconocimiento Visual de Modelos/fisiología , Tiempo de Reacción/fisiología , Semántica , Medición de la Producción del Habla , Resultado del TratamientoRESUMEN
A considerable number of studies has been conducted on switchgrass (Panicum virgatum L.) as a bioresource for energy over the last few years. Nonetheless, some important issues concerning the agro-technique are still open. This research examines the long-term total dry matter yield (TDM) and ash content of two lowland (L) and two upland (U) switchgrass cytotypes, as affected by one or two-cut system, under southern EU climatic conditions (44 degrees 33' N). Overall, L produced higher TDM than U (on average 14.9 and 11.7 Mg ha(-1), respectively); two-cut system allowed to produce higher biomass yields (especially in U) than single harvest during the two first years, but it also drastically reduced plant vigour and productivity of all cytotypes in the following two years. Moreover, under two-cut system almost total seasonal biomass derived from the early harvest, while the second cut slightly contributed to the total seasonal biomass, nor it appeared to offset the additional harvest costs. Biomass quality was also significantly affected by cutting frequency, with two-cut system leading to a considerably higher ash content of biomass. Therefore, it is perceived that two-cut system is not worthwhile with U and L cytotypes as bioresource for energy production under southern EU conditions.
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Fuentes Generadoras de Energía/economía , Panicum/crecimiento & desarrollo , Agricultura/métodos , Biomasa , Clima , Eficiencia , Fuentes Generadoras de Energía/estadística & datos numéricos , Geografía , Panicum/clasificación , Estaciones del AñoRESUMEN
Solid-Phase Peptide Synthesis (SPPS) is a rapid and efficient methodology for the chemical synthesis of peptides and small proteins. However, the assembly of peptide sequences classified as "difficult" poses severe synthetic problems in SPPS for the occurrence of extensive aggregation of growing peptide chains which often leads to synthesis failure. In this framework, we have investigated the impact of different synthetic procedures on the yield and final purity of three well-known "difficult peptides" prepared using oxyma as additive for the coupling steps. In particular, we have comparatively investigated the use of piperidine and morpholine/DBU as deprotection reagents, the addition of DIPEA, collidine and N-methylmorpholine as bases to the coupling reagent. Moreover, the effect of different agitation modalities during the acylation reactions has been investigated. Data obtained represent a step forward in optimizing strategies for the synthesis of "difficult peptides".
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Péptidos/síntesis química , Pregnadienos/química , Agregado de Proteínas , Técnicas de Síntesis en Fase Sólida , Acilación , Secuencia de Aminoácidos , Etilaminas/química , Morfolinas/química , Péptidos/química , Péptidos/genética , Piperidinas/química , Piridinas/químicaRESUMEN
Activated C protein resistance is a common coagulation defect caused by factor V Leiden mutation and is associated with an augmented risk of predominantly venous thrombosis. Augmented tendency to arterial thrombosis is sporadically reported. This case report describes femoropopliteal thrombosis in a young patient with heterozygous V Leiden factor mutation. Progressive thrombotic occlusion required amputation of the forefoot which resulted in stump dehiscence. Poor blood supply to the perilesional substrate delayed wound healing. An optimal though not yet definitive result was achieved after months of accurate medication. The criticality of lower limb ischemia in an otherwise healthy young patient underscores the grave impact this condition can have on the patient's quality of life and on health care costs.
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Factor V/genética , Arteria Femoral , Mutación , Arteria Poplítea , Trombosis/genética , Resistencia a la Proteína C Activada/genética , Adulto , Amputación Quirúrgica/efectos adversos , Amputación Quirúrgica/métodos , Heterocigoto , Humanos , Masculino , Trombosis/complicaciones , Trombosis/cirugía , Cicatrización de HeridasRESUMEN
INTRODUCTION: Switching from fluindione, an indanedione vitamin K antagonist derivative, to warfarin, a coumarin one, or vice versa, requires to know the relationships between dosages of these two molecules. METHODS: We conducted a prospective study in 288 consecutive patients aged 70 years and over, converted from fluindione to warfarin. Patients who were retained for the analysis were those for whom maintenance dosages were obtained for both vitamin K antagonists. RESULTS: Eighty-two patients, mean aged 83 ± 6 years, were analysed. The average daily maintenance dosages were 13.8 ± 6.7 mg (range 5-35) and 3.7 ± 1.7 mg (range 1-8) for fluindione and warfarin, respectively. Using a linear regression model, we built a transition algorithm for the maintenance dosages of warfarin and fluindione. CONCLUSION: This is the first study to propose a conversion algorithm to help prescribers to estimate the maintenance dosage when it is necessary for a patient to switch from fluindione to warfarin or conversely.
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Anticoagulantes/administración & dosificación , Cálculo de Dosificación de Drogas , Nomogramas , Fenindiona/análogos & derivados , Trombosis/prevención & control , Warfarina/administración & dosificación , Anciano , Anciano de 80 o más Años , Envejecimiento/metabolismo , Algoritmos , Anticoagulantes/farmacocinética , Relación Dosis-Respuesta a Droga , Sustitución de Medicamentos , Femenino , Humanos , Masculino , Fenindiona/administración & dosificación , Fenindiona/farmacocinética , Equivalencia Terapéutica , Trombosis/metabolismo , Warfarina/farmacocinéticaRESUMEN
Two blood pressure (BP) measurements separated by 3 months were performed according to international guidelines on 2976 students (11 to 19 years) of different economic levels. Obesity was defined based upon height and weight. With the first measurements, 59th and 95th percentile value distribution curves were defined. Systolic hypertension (SH) was found in 9.5%; 10.2% were males and 8.9% females. The sample showed that 8.1% were obese (240 cases); among them the incidence of SH increased to 28.8% (69 cases) (p less than 0.01). In the entire sample, diastolic hypertension (DH) was 4.3%; males, 2.7%, and females, 5.5% (p less than 0.01). Among obese students, DH increased to 8.3% (20 cases) (p less than 0.01), and showed prevalence figures of 5.8% for obese males and 10.3% (14 cases) for obese females. After a second measurement, DH for the sample decreased to 1.8%. Salt intake and familial antecedents of high BP showed differences between hypertensive and normal populations.
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Presión Sanguínea , Servicios de Salud Escolar , Población Urbana , Adolescente , Adulto , Niño , Chile , Diástole , Femenino , Humanos , Hipertensión/epidemiología , Hipertensión/genética , Masculino , Riesgo , Factores Sexuales , SístoleRESUMEN
Between 1 March and 30 April (1994) we recorded the errors detected by the physician, the radiographer or the physicist during prescription, preparation and execution phases of 227 treatment plans. The radiation treatment modalities used were the following: (i) single or opposed fields, moulded or not; and (ii) multiple fields or kinetic techniques. The total number of sessions performed is 1613 with the cobalt unit and 2131 with the linear accelerator (total, 3744). The total number of wrong data is 155, consisting of 24/227 (10.5%) in compilation, 22/3744 (0.58%) in execution and 109/3744 (2.9%) in registration phases. The number of missing data is 140, consisting of 10/227 (4.4%) in compilation, 9/3744 (0.2%) in execution and 121/3744 (3.2%) in registration phases. Wrong data of compilation, even if in high rate (10.5%), were all found during the same compilation phase or at the first treatment, so that they did not alter the exactness of the treatment plan. Wrong and missing data, found in the registration phase (2.9% and 3.2%, respectively), depend on the repetition of daily treatment and on the registration of data on the chart after having digitized them on the display.
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Registros Médicos , Planificación de Atención al Paciente , Radioterapia , Radioisótopos de Cobalto/administración & dosificación , Radioisótopos de Cobalto/uso terapéutico , Estudios de Evaluación como Asunto , Control de Formularios y Registros , Física Sanitaria , Humanos , Grupo de Atención al Paciente , Oncología por Radiación , Radiografía , Radiometría , Dosificación Radioterapéutica , Radioterapia de Alta Energía/métodosRESUMEN
We illustrate a radiotherapy treatment chart elaborated to fulfil the necessity for clarity in reporting information about radiotherapeutic treatment. The schematic configuration of the chart results from the experience and the cooperation of physicists, physicians and technicians, and an effort has been made to satisfy Levels 2/3 of the ICRU 50 recommendations. The chart has been divided into four sections corresponding to different kinds of information: a cover sheet, a section containing data about the treatment planning geometry and the console parameters adopted, a section showing dosimetric data, and a section showing treatment data. The chart seems to give a good level of accuracy in reporting treatment plan information.
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Registros Médicos , Radioterapia , Humanos , Radioterapia/normas , Dosificación RadioterapéuticaRESUMEN
Local delivery of antimicrobial agents in inflamed periodontal pocket has been shown to be effective in reducing periodontopathic microorganisms. This research focuses on developing and characterizing bioerodible formulations based on auto-catalyzed poly(ortho esters) (POExLAy) for modulated release of tetracycline over 2 weeks. POExLAy are a new versatile family of POE-containing lactoyl lactyl dimers in the polymer backbone. By modifying the proportion of lactic acid in the polymer, viscous or solid materials having different degradation rate can be produced. The formulations can be either injected or placed as a solid device directly into the periodontal pocket. Tetracycline-free base incorporated into these materials was released within 10-14 days depending on polymer structure. Increase in lactic acid content in the polymer tended to increase the drug release rate and to reduce the initial lag time. Tetracycline release from such bioerodible delivery system occurs predominantly by surface erosion of the polymeric matrix, leading to kinetics which can be zero order. This periodontal drug delivery system is designed to be used as an adjunct in the treatment of periodontal diseases. Clinical studies are currently in progress.
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Materiales Biocompatibles , Bolsa Periodontal/tratamiento farmacológico , Bolsa Periodontal/fisiopatología , Polímeros/química , Tetraciclina/administración & dosificación , Tetraciclina/química , Catálisis , Cromatografía Líquida de Alta Presión , Preparaciones de Acción Retardada , Portadores de Fármacos , Estabilidad de Medicamentos , Humanos , Ácido Láctico , Estructura Molecular , Espectrometría de Masa por Ionización de Electrospray , Relación Estructura-ActividadRESUMEN
AIMS: With the complex demodulation (CDM) method, we assessed the instantaneous amplitude and frequency of cardiovascular (CV) and respiratory oscillations, and the instant phase (IP) between the CV and respiratory signals using respiration as a periodic forced stimulation. We hypothesised a possible lack of synchronisation between CV and respiratory signals under regular breathing at different frequencies. METHODS: RR interval (ECG), blood pressure (SBP/DBP, Finapress), respiration (Respitrace) were monitored during two random-order periods of voluntary paced-breathing (0.15 Hz/0.25 Hz) in 10 moderate CHF patients and 10 age-matched controls. The CDM method provides the amplitude and frequency of a particular spectral component as a function of time in both LF and HF bands. IP between CV and respiratory oscillations was assessed using the real modulating breathing rate. RESULTS: (i) Continuous phase variations between CV oscillations and the respiratory signal were evidenced in CHF patients, the slower the breathing rate, the greater the phase variation (RR/Resp; 0.25 Hz, 23+/-17 degrees; 0.15 Hz, 46+/-57 degrees, P<0.01; RR/Resp at 0.15 Hz 6+/-3 vs. 46+/-57 P<0.01 controls vs. CHF). Phase was constant in controls. (ii) In patients, the instant amplitude of the cardiovascular oscillations in the high frequency domain is more markedly altered when the breathing rate was slowed down as compared to controls. CONCLUSION: The lack of synchronisation between physiological signals during voluntary breathing in CHF patients highlights a central uncoupling between CV and respiratory neuronal activities.
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Sistema Cardiovascular/fisiopatología , Insuficiencia Cardíaca/fisiopatología , Sistema Respiratorio/fisiopatología , Adulto , Presión Sanguínea/fisiología , Enfermedad Crónica , Electrocardiografía , Femenino , Insuficiencia Cardíaca/terapia , Ventilación de Alta Frecuencia , Humanos , Masculino , Persona de Mediana Edad , Variaciones Dependientes del Observador , Respiración , Sístole/fisiología , Factores de TiempoRESUMEN
BACKGROUND: We assessed the behavior of the baroreflex (BR) gain in chronic heart failure (CHF) patients using the spectral analysis method during application of a forcing stimulus, i.e. respiration. METHODS: Simultaneous RR interval and arterial pressure fluctuation recordings were obtained during two random-order periods of voluntary paced-breathing (0.15 Hz and 0.25 Hz) in seven patients with moderate CHF (NYHA class II/III; EF, 30+/-9%; peak VO(2), 18+/-5 ml kg(-1) min(-1)) and six age-matched controls. BR gain was assessed in the time (sequential method) and frequency (cross-spectral gain in the low and high frequency) domains. RESULTS: Slower breathing was associated with a BR gain decrease in CHF patients whereas a BR gain increase was evidenced in controls (BR gain: 6+/-5 ms mmHg(-1) at 0.25 Hz vs. 4+/-3 ms mmHg(-1) at 0.15 Hz, P<0.05 in CHF; BR gain: 12+/-7 ms mmHg(-1) at 0.25 Hz vs. 15+/-7 ms mmHg(-1) at 0.15 Hz, P<0.05 in controls). CONCLUSIONS: Voluntary breathing, which involves cortical centers in the brain, had major effects on cardiovascular system controller gain in CHF patients, indicating an impairment of the central neural regulation of the autonomic outflow.
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Insuficiencia Cardíaca/fisiopatología , Presorreceptores/fisiopatología , Ventilación Pulmonar/fisiología , Adulto , Sistema Nervioso Autónomo/fisiopatología , Biorretroalimentación Psicológica/fisiología , Presión Sanguínea/fisiología , Enfermedad Crónica , Femenino , Insuficiencia Cardíaca/diagnóstico , Humanos , Masculino , Persona de Mediana EdadRESUMEN
Since behavioural symptoms (tremor, irritability, pilo-erection and shaking) induced by imidazole (IMID) in rats suggested an underlying modification of arousal and/or emotionality, further studies were performed in order to extend the range of behavioural influences of IMID. In the open-field test, IMID (37.5-300 mg/kg IP) inhibited crossing and rearing in a dose-dependent fashion, this effect being long lasting (about 3 h at 75 mg/kg). Yohimbine (YOH) (1, 5 and 10 mg/kg IP), described as anxiogenic and fear-inducing in animals and in man, when investigated in this same test, inhibited the activity of rats similarly to IMID. Since diazepam (0.5 and 1 mg/kg) but not clonidine (0.075 and 0.150 mg/kg IP) pretreatment reversed IMID- and YOH-induced hypomotility, the hypothesis that IMID effects in the open field might reflect an anxiety-like state was investigated by means of social interaction and x-maze, two tests considered highly specific for anxiety studies. The data obtained show that IMID depresses social interactions only at doses inhibiting motor activity; YOH, in our experimental conditions, produced a similar effect. In an elevated x-maze, with alternate open and closed arms, IMID (37.5 and 75 mg/kg) decreased the proportion of open-arm entries and the time spent in them, an effect prevented by diazepam pretreatment (1 mg/kg IP). Finally, mean arterial pressure (MAP) was assessed in anesthetized rats treated with IMID and YOH at doses equivalent as regards behavioural effects. MAP was increased by IMID whether IP or IV and decreased by YOH; moreover, YOH, as expected, antagonized clonidine-induced hypotension, while IMID was ineffective.(ABSTRACT TRUNCATED AT 250 WORDS)
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Ansiedad/psicología , Conducta Animal/efectos de los fármacos , Imidazoles/farmacología , Animales , Nivel de Alerta/efectos de los fármacos , Presión Sanguínea/efectos de los fármacos , Clonidina/farmacología , Diazepam/farmacología , Emociones/efectos de los fármacos , Hemodinámica/efectos de los fármacos , Masculino , Actividad Motora/efectos de los fármacos , Ratas , Ratas Endogámicas , Conducta Social , Yohimbina/farmacologíaRESUMEN
A quick formula is proposed for calculating equivalent squares of irregularly shaped photon fields. No complex calculations are required. Three different energies (60Co; 6 MV and 18 MV x-rays) were investigated. Comparison with results utilizing the Clarkson technique (60Co) and with experimental measurements (6 MV and 18 MV x-rays) indicates that the method is accettable in a wide variety of clinical situations. The applied procedure introduces an indetermination lower than 4%, with maximum absolute percentage errors of 3%, 2.7%, and 3.6% for 6 MV, 18 MV, and 60Co photon fields respectively.