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1.
Chemosphere ; 282: 131128, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34470167

RESUMO

We introduce a novel, efficient and fast method for the total and simultaneous removal of monomethylmercury, dimethylmercury, ethylmercury and Hg (II) from aquatic environments using magnetic core nanoparticles, coated with metallic nanomeric silver and functionalized with l-Cysteine. As far as the authors know, simultaneous removal has not been achieved previously. The experimental design was based on exploring a wide range of experimental conditions, including pH of the medium (2-12), contact time (up to 20 min), adsorbent dose (50-800 µL) and temperature (293-323 K), in order to achieve the highest adsorption efficiency. The results show that, for a pH equal to 6.2 at room temperature, 400 µL of nanoparticles is sufficient to achieve 100% adsorption efficiency for all the studied Hg species after a contact time of 30 s. The adsorbent was characterized by means of Scanning Electron Microscopy, Energy Dispersive X-ray Analysis, Fourier-Transform Infrared Spectroscopy and a BET test. Moreover, the procedure allows the total recovery and recycling of the nanoparticles using 50 µL of 0.01 M KI. As regards reuse, the adsorbent exhibits no loss of adsorption capacity during the first three adsorption cycles. Thermodynamics reveals that adsorption is of a physicochemical nature, the equilibrium isotherms being described by a Langmuir model for all the Hg species. The ability of the method to simultaneously adsorb all species of mercury present in water, achieving full adsorption in just a few seconds, along with the simple experimental conditions and its cost-effectiveness, strongly support the approach as an alternative to current procedures.


Assuntos
Nanopartículas de Magnetita , Mercúrio , Poluentes Químicos da Água , Adsorção , Cisteína , Concentração de Íons de Hidrogênio , Cinética , Projetos de Pesquisa , Prata , Espectroscopia de Infravermelho com Transformada de Fourier , Termodinâmica , Poluentes Químicos da Água/análise
3.
Sci Total Environ ; 709: 136111, 2020 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-31884287

RESUMO

Phosphate removal is an important factor that must be taken into account in eutrophized waters. For this reason, many studies on different ways of removing phosphates from water have been published nowadays. In this work, a comparative study between the use of graphene oxide (GO) and graphene oxide functionalized with silver nanoparticles (GO@AgNPs) as adsorbents to remove phosphates from water samples has been carried out. Experimental conditions, including the pH, adsorbent dose, contact time and temperature, have been analyzed to achieve the highest adsorption efficiency. Although both adsorbents can be considered suitable for removing phosphates from aqueous solutions, GO@AgNPs provided a maximum removal efficiency of 100%, reaching the equilibrium conditions instantaneously under straightforward experimental conditions. Moreover, a much lower adsorbent dose was necessary than with graphene oxide. When GO was used, the maximum removal efficiency was 75%, 9 min were necessary to reach the equilibrium conditions and 20 mg of adsorbent were needed. Both adsorbents can be regenerated in an acid medium, giving recovery percentages of 98% and 80% for GO and GO@AgNPs respectively, which allows them to be recycled and used again.

4.
Res Sports Med ; 24(3): 281-6, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27357919

RESUMO

Although all authors report beneficial health changes following training based on the Pilates method, no explicit analysis has been performed of its cardiorespiratory effects. The objective of this study was to evaluate possible changes in cardiorespiratory parameters with the Pilates method. A total of 45 university students aged 18-35 years (77.8% female and 22.2% male), who did not routinely practice physical exercise or sports, volunteered for the study and signed informed consent. The Pilates training was conducted over 10 weeks, with three 1-hour sessions per week. Physiological cardiorespiratory responses were assessed using a MasterScreen CPX apparatus. After the 10-week training, statistically significant improvements were observed in mean heart rate (135.4-124.2 beats/min), respiratory exchange ratio (1.1-0.9) and oxygen equivalent (30.7-27.6) values, among other spirometric parameters, in submaximal aerobic testing. These findings indicate that practice of the Pilates method has a positive influence on cardiorespiratory parameters in healthy adults who do not routinely practice physical exercise activities.


Assuntos
Adaptação Fisiológica , Técnicas de Exercício e de Movimento , Condicionamento Físico Humano/fisiologia , Adolescente , Adulto , Teste de Esforço , Feminino , Frequência Cardíaca , Humanos , Masculino , Consumo de Oxigênio , Troca Gasosa Pulmonar , Espirometria , Adulto Jovem
5.
Pediatr. catalan ; 76(2): 67-70, abr.-jun. 2016. tab
Artigo em Catalão | IBECS | ID: ibc-156636

RESUMO

Introducció: lhiperinsulinisme (HI) és la causa més freqüent dhipoglucèmia neonatal mantinguda. Es pot dividir en transitori o secundari i persistent o congènit. Es presenta una revisió del tema, a partir de quatre casos diagnosticats a la nostra unitat durant set anys. Observació clínica: dels quatre casos, tres són transitoris o secundaris i un persistent. Els factors predisposants dels transitoris són la pèrdua del benestar fetal i la diabetis gestacional. El persistent, amb una ressonància magnètica (RM) cranial i un estudi genètic normals, no va respondre al tractament amb diazòxid (DI) i va millorar amb dextrinomaltosa i alimentació contínua. Cap cas va presentar seqüeles neurològiques. Comentaris: els nostres casos compleixen els criteris diag-nòstics dHI. La incidència dHI al nostre centre és d1/4.500 nascuts vius i la dHI persistent d1/20.000 nascuts vius en set anys. LHI transitori o secundari es relaciona amb lasfíxia neonatal, el retard del creixement intrauterí i la diabetis gestacional. Els casos descrits presen-ten pèrdua del benestar fetal i diabetis. El tractament inicial és laportació de glucosa. Després, el fàrmac de primera línia és el DI. LHI persistent acostuma a no respondre al tractament i pot ser focal o difús, el primer dels quals es pot beneficiar de cirurgia. El màxim objectiu és la prevenció de seqüeles neurològiques. És fonamental el maneig conjunt amb un especialista endocrinòleg


Introducción. El hiperinsulinismo (HI) es la causa más frecuente de hipoglucemia neonatal mantenida. Se puede dividir en transitorio o secundario y persistente o congénito. Se presenta una revisión del tema, a partir de cuatro casos diagnosticados en nuestra unidad durante siete años. Observación clínica. De los cuatro casos, tres son transitorios o secundarios y uno persistente. Los factores predisponentes de los transitorios son la pérdida del bienestar fetal y la diabetes gestacional. El persistente, con una resonancia magnética (RM) craneal y un estudio genético normales, no respondió al diazóxido (DI) y mejoró con dextrinomaltosa y alimentación continua. Ningún caso presentó secuelas neurológicas. Comentarios. Nuestros casos cumplen los criterios diagnósticos de HI. La incidencia de HI en nuestro centro es de 1/4.500 nacidos vivos y la de HI persistente de 1/20.000 nacidos vivos en siete años. El HI transitorio o secundario se relaciona con la asfixia neonatal, el retraso del crecimiento intrauterino y la diabetes gestacional. Los casos descritos presentan pérdida del bienestar fetal y diabetes. El tratamiento inicial es el aporte de glucosa. Después, el fármaco de primera linea es el DI. El HI persistente acostumbra a no responder al tratamiento y puede ser focal o difuso, el primero de los cuales puede beneficiarse de cirugía. El máximo objetivo es la prevención de secuelas neurológicas. Es fundamental el manejo conjunto con un especialista endocrinólogo (AU)


Introduction. Hyperinsulinism (HI) is the most frequent cause of sustained neonatal hypoglycemia; it can be transient (secondary) or persistent (congenital). We describe four cases of neonatal HI seen in a neonatal unit over a seven-year period. Clinical observation. Three of the four cases were transient or secondary, and the other was persistent. Loss of fetal wellbeing and gestational diabetes were the predisposing factors in the three transient cases. The case of persistent HI had normal brain magnetic resonance imaging and genetics; it did not respond to treatment wth diazoxide (DI) but improved with continuous feeding and dextrinomaltose. All four cases recovered with no neurological sequelae. Comments. Our fours cases met the diagnosis criteria for HI. Over the seven-year period, the overall incidence of HI was 1 in 4,500 live births, while the incidence of persistent HI was 1 in 20,000 live births. Transient or secondary HI is related to birth asphyxia, intrauterine growth retardation, and gestational diabetes. The initial treatment of HI is with glucose and DI. Persistent or congenital HI seldom responds to treatment and it can be the result of focal or diffuse pancreatic disease, the first of which anomalies could benefit from surgery. Prevention of neurological sequelae is the main objective of the treatment. A multidisciplinary management with endocrinology is recommended (AU)


Assuntos
Humanos , Masculino , Feminino , Recém-Nascido , Lactente , Pré-Escolar , Criança , Hiperinsulinismo/sangue , Hiperinsulinismo/complicações , Hiperinsulinismo/diagnóstico , Hipoglicemia/complicações , Hipoglicemia/diagnóstico , Diazóxido/uso terapêutico , Glucose/uso terapêutico , Imageamento por Ressonância Magnética/métodos , Estatísticas de Sequelas e Incapacidade
6.
J Phys Condens Matter ; 25(13): 135404, 2013 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-23470526

RESUMO

The pressure dependences of the structural, thermoelastic and vibrational properties of SnO2 in its rutile phase are studied, as well as the pressure-induced transition to a CaCl2-type phase. These studies have been performed by means of ab initio (AI) density functional theory calculations using the localized basis code SIESTA. The results are employed to develop a shell model (SM) for application in future studies of nanostructured SnO2. A good agreement of the SM results for the pressure dependences of the above properties with the ones obtained from present and previous AI calculations as well as from experiments is achieved. The transition is characterized by a rotation of the Sn-centered oxygen octahedra around the tetragonal axis through the Sn. This rotation breaks the tetragonal symmetry of the lattice and an orthorhombic distortion appears above the critical pressure P(c). A zone-center phonon of B1g symmetry in the rutile phase involves such rotation and softens on approaching Pc. It becomes an Ag mode which stabilizes with increasing pressure in the CaCl2 phase. This behavior, together with the softening of the shear modulus (C11-C12)/2 related to the orthorhombic distortion, allows a precise determination of a value for Pc. An additional determination is provided by the splitting of the basal plane lattice parameters. Both the AI and the experimentally observed softening of the B(1g) mode are incomplete, indicating a small discontinuity at the transition. However, all results show continuous changes in volume and lattice parameters, indicating a second-order transition. All these results indicate that there should be sufficient confidence for the future employment of the shell model.

7.
J Phys Condens Matter ; 21(1): 015501, 2009 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-21817222

RESUMO

In this work, we study theoretically the elastic properties of the orthorhombic (Pnma) high-pressure phase of IV-B group oxides: titania, zirconia and hafnia. By means of the self-consistent SIESTA code, pseudopotentials, density functional theory in the LDA and GGA approximations, the total energies, hydrostatic pressures and stress tensor components are calculated. From the stress-strain relationships, in the linear regime, the elastic constants C(ij) are determined. Derived elastic constants, such as bulk, Young's and shear modulus, Poisson coefficient and brittle/ductile behavior are estimated with the polycrystalline approach, using Voigt-Reuss-Hill theories. We have found that C(11), C(22) and C(33) elastic constants of hafnia and zirconia show increased strength with respect to the experimental values of the normal phase, P 2(1)/c. A similar situation applies to titania if these constants are compared with its normal phase, rutile. However, shear elastic constants C(44), C(55) and C(66) are similar to the values found in the normal phase. This fact increases the compound anisotropy as well as its ductile behavior. The dependence of unit-cell volumes under hydrostatic pressures is also analyzed. P-V data, fitted to third-order Birch-Murnaghan equations of state, provide the bulk modulus B(0) and its pressure derivatives B'(0). In this case, LDA estimations show good agreement with respect to recent measured bulk moduli of ZrO(2) and HfO(2). Thermo-acoustic properties, e.g. the propagation speed of transverse, longitudinal elastic waves together with associated Debye temperatures, are also estimated.

8.
Phys Rev Lett ; 101(5): 056601, 2008 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-18764413

RESUMO

We study relaxation in two-dimensional Coulomb glasses up to macroscopic times. We use a kinetic Monte Carlo algorithm especially designed to escape efficiently from deep valleys around metastable states. We find that, during the relaxation process, the site occupancy follows a Fermi-Dirac distribution with an effective temperature much higher than the real temperature T. Long electron-hole excitations are characterized by T(eff), while short ones are thermalized at T. We argue that the density of states at the Fermi level is proportional to T(eff) and is a good thermometer to measure it. T(eff) decreases extremely slowly, roughly as the inverse of the logarithm of time, and it should affect hopping conductance in many experimental circumstances.

9.
J Phys Condens Matter ; 17(37): 5795-5811, 2005 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-32397049

RESUMO

The SIESTA approach based on pseudopotentials and a localized basis set is used to calculate the electronic, elastic and equilibrium properties of P 21/c, Pbca, Pnma, Fm3m, P42nmc and Pa3 phases of HfO2. Using separable Troullier-Martins norm-conserving pseudopotentials which include partial core corrections for Hf, we tested important physical properties as a function of the basis set size, grid size and cut-off ratio of the pseudo-atomic orbitals (PAOs). We found that calculations in this oxide with the LDA approach and using a minimal basis set (simple zeta, SZ) improve calculated phase transition pressures with respect to the double-zeta basis set and LDA (DZ-LDA), and show similar accuracy to that determined with the PPPW and GGA approach. Still, the equilibrium volumes and structural properties calculated with SZ-LDA compare better with experiments than the GGA approach. The bandgaps and elastic and structural properties calculated with DZ-LDA are accurate in agreement with previous state of the art ab initio calculations and experimental evidence and cannot be improved with a polarized basis set. These calculated properties show low sensitivity to the PAO localization parameter range between 40 and 100 meV. However, this is not true for the relative energy, which improves upon decrease of the mentioned parameter. We found a non-linear behaviour in the lattice parameters with pressure in the P 21/c phase, showing a discontinuity of the derivative of the a lattice parameter with respect to external pressure, as found in experiments. The common enthalpy values calculated with the minimal basis set give pressure transitions of 3.3 and 10.8 GPa for [Formula: see text] and [Formula: see text], respectively, in accordance with different high pressure experimental values.

10.
Nutr. clín. diet. hosp ; 24(1): 15-21, ene. 2004. tab
Artigo em Es | IBECS | ID: ibc-31540

RESUMO

Justificación: el Ramadán se caracteriza por un período de ayuno acompañado de restricción hídrica durante el día, cambiando la ingesta de sólidos y líquidos a la noche durante un mes lunar. El propósito de este estudio ha sido valorar en un grupo de escolares adolescentes, la influencia del ayuno del Ramadán en el equilibrio hidrosalino. Metodología: para ello se seleccionaron de forma aleatoria un grupo de adolescentes escolarizados en centros multiconfesionales de la Ciudad Autónoma de Ceuta, que tras ser convenientemente informados aceptaron participar voluntariamente en el estudio. Se han analizado parámetros fisiológicos como peso, talla, frecuencia cardíaca, presión arterial, electrolitos en plasma y orina, osmolaridad, volumen plasmático y concentraciones hormonales de renina, aldosterona y vasopresina o ADH. Dichos parámetros se determinaron antes (A), durante (B y C) y después (D) del Ramadán. Resultados: los valores de aldosterona disminuyeron en la primera semana del Ramadán (B) y se elevaron considerablemente en las siguientes (A: 410,6ñ47,65; B: 278,2ñ27,60; C: 528,12ñ50,37 y D: 578,12ñ78,24 pg/mL), mientras que la ADH no se modificó significativamente en la primera semana de ayuno (B), disminuyendo en las posteriores (A: 9,1ñ0,78; B:8,9ñ0,79; C: 5,65ñ0,08 y D: 6,22ñ0,32 pg/mL). Los niveles plasmáticos de Na+ y K+ y sus fracciones de excreción mostraron variaciones coherentes con las de dichas hormonas. Conclusiones: la hiperhidratación debida a la ingesta excesiva de agua antes de salir el sol, provoca una hemodilución con disminución de la osmolaridad y mantenimiento del volumen plasmático y presión arterial (PA) a expensas de la inhibición de vasopresina o ADH y de Renina. El aumento en los niveles de K+ plasmáticos, sería responsable de la secreción significativamente elevada de aldosterona (p<0,05), observada el día 21de ayuno (C) y del aumento concomitante de la fracción de excreción de K+ (p<0,05) (AU)


Assuntos
Adolescente , Masculino , Humanos , Equilíbrio Hidroeletrolítico , Homeostase , Islamismo , Jejum/sangue , Hemodinâmica , Fenômenos Fisiológicos da Nutrição do Adolescente , Espanha , Estudos de Casos e Controles , Estudos de Coortes , Aldosterona/sangue , Religião
11.
Adv Perit Dial ; 18: 200-5, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-12402619

RESUMO

Treatment with recombinant human erythropoietin (rHuEPO) in dialysis patients has been associated with improvement of nutritional and immune status through an increase of cytokine production [such as tumor necrosis factor alpha (TNF alpha)]. The high cytokine production can be a double-edged sword owing to the relationship of cytokines with the systemic inflammatory process, which has been associated with many complications of uremic status. Our aim was to analyze the medium-long term effects of rHuEPO treatment on uremic inflammatory markers. We studied 45 peritoneal dialysis (PD) patients divided in two groups: a rHuEPO group (40-70 subcutaneous units/kg weekly) and a control group (no rHuEPO). The treated group was analyzed in four periods. Period 1 (rHuEPO-1) included 24 patients who had been using rHuEPO at long-term. Period 2 (rHuEPO-2; n = 21) looked at the patients 2 months after rHuEPO withdrawal. Period 3 (rHuEPO-3; n = 19) looked at the patients after 2 months under rHuEPO therapy. Period 4 (rHuEPO-4; n = 17) looked at the patients after 4 months on rHuEPO treatment. With the reintroduction of rHuEPO, we observed a progressive, statistically significant (p < 0.05), and temporary increase in TNF alpha plasma levels, from 44 +/- 24 pg/mL (rHuEPO-2) to 76.8 +/- 25 pg/mL (rHuEPO-3), and then to 83 +/- 27 pg/mL (rHuEPO-4). But in the long term, TNF alpha decreased [33.5 +/- 10 pg/mL (rHuEPO-1)]. Similarly, albumin increased in the short term (3.73 +/- 0.5 g/dL to 4 +/- 0.5 g/dL, and then to 4 +/- 0.43 g/dL), and then decreased (3.8 +/- 0.44 g/dL). The normalized protein catabolic rate (nPCR) increased from 1 +/- 0.2 g/kg daily to 1.12 +/- 0.3 g/kg daily (rHuEPO-4). Long term, nPCR decreased to 1.06 +/- 0.3 g/kg daily. Leptin initially increased (60.1 +/- 48 ng/mL to 42.8 +/- 22 ng/mL, and then to 38 +/- 18.2 ng/mL); it also increased in the long term (62 +/- 50.9, p < 0.05). At baseline, we found a significant positive linear correlation (p < 0.05) between TNF alpha and leptin (r = 0.52), TNF alpha and C-reactive protein [(CRP) r = 0.4], CRP and leptin (r = 0.49), fibrinogen and CRP (r = 0.78, p < 0.01), fibrinogen and leptin (r = 0.37), and leptin and body mass index [(BMI) r = 0.67]. In conclusion, rHuEPO induces a temporary, non inflammatory immune hyperactivity mediated by TNF alpha, without the adverse effects associated with that cytokine. By decreasing leptin, rHuEPO could increase food intake and improve the nutritional status of PD patients. At baseline, we confirm the existence of a chronic inflammatory process in uremia.


Assuntos
Eritropoetina/efeitos adversos , Diálise Peritoneal , Adulto , Idoso , Idoso de 80 Anos ou mais , Índice de Massa Corporal , Proteína C-Reativa/análise , Eritropoetina/uso terapêutico , Feminino , Humanos , Inflamação/sangue , Leptina/sangue , Masculino , Pessoa de Meia-Idade , Diálise Peritoneal Ambulatorial Contínua , Proteínas/metabolismo , Proteínas Recombinantes , Albumina Sérica/análise , Fator de Necrose Tumoral alfa/metabolismo
12.
Geriátrika (Madr.) ; 18(6): 125-129, jun. 2002.
Artigo em Es | IBECS | ID: ibc-13260

RESUMO

En este trabajo se ha analizado la relación entre el estilo de vida y el perfil lipídico, como factor de riesgo para la salud. Se han seleccionado 15 sujetos deportistas “senior” sanos, atletas especialistas en carrera de fondo, con una media de edad de 51 años, 69 Kg como peso medio y 1,69m como estatura media. Su participación en el estudio fue voluntaria, junto a la de otros 12 sujetos sedentarios y de similares características socioculturales, que configuraron el grupo control, con una media de edad de 49 años, un peso medio de 83 Kg y una talla de 1,72 m. Se ha utilizado el cuestionario de estilos de vida de Heyward sobre hábitos relacionados con la bebida, tabaco, ejercicio físico y dieta, así como la determinación de los niveles de lípidos en sangre (TG, Colesterol total, HDL, LDL, VLDL, y cociente LDL/ HDL Se han comparado los niveles basales de lípidos en ambos grupos con relación al estilo de vida. Los resultados de nuestro trabajo muestran hábitos menos saludables en el grupo de sujetos sedentarios, con mayor ingesta de alcohol y tabaco y significativamente menor realización de ejercicio físico que en el grupo de atletas. El perfil lipídico muestra valores inferiores de colesterol total, triglicéridos, LDL,VLDL, LDL/HDL y mayores de HDL en el grupo de atletas cuyo consumo de alcohol es menor, no consumen tabaco y entrenan de forma regular. El ejercicio físico en nuestro estudio se constituye como el hábito de mayor relevancia en la configuración de unas características antropométricas y un perfil lipídico óptimos para la promoción de la salud y desarrollo de estilos de vida saludables (AU)


Assuntos
Pessoa de Meia-Idade , Humanos , Estilo de Vida , Lipídeos/sangue , Esportes , Consumo de Bebidas Alcoólicas , Tabagismo , Dieta , Fatores de Risco
13.
Nefrologia ; 20(2): 139-44, 2000.
Artigo em Espanhol | MEDLINE | ID: mdl-10853194

RESUMO

The presence of genetic prothrombotic factors (factor V Leiden and the prothrombin II20210 mutation) was investigated in 38 patients with glomerulonephritis with or without a history of thrombotic events and/or nephrotic syndrome. We found an increased prevalence (36%) of heterozygous factor V Leiden in those patients with a history of thrombotic events. This is ten times the prevalence in the normal Spanish population. Carrier status for this mutation may be a determining factor in the development of thrombotic events along with the acquired disorders of coagulation to which these patients are prone. We found only one patient who was a carrier of the G-A II20210 mutation of the prothrombin gene; this patient had no history of venous thrombosis or embolism. Our findings suggest the need to measure activated protein C resistance and to look for the most frequent genotype causing it, Factor V Leiden, in patients with glomerulonephritis to identify those at risk who may benefit from prophylaxis against thrombosis.


Assuntos
Resistência à Proteína C Ativada/genética , Fator V/genética , Glomerulonefrite/complicações , Glomerulonefrite/genética , Protrombina/genética , Trombose/complicações , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Mutação , Prevalência
14.
Nefrología (Madr.) ; 20(2): 139-144, mar. 2000.
Artigo em Es | IBECS | ID: ibc-6183

RESUMO

Se investigó de forma prospectiva en 38 pacientes portadores de nefropatías glomerulares, con o sin antecedentes de síndrome nefrótico y/o manifestaciones tromboembólicas, la presencia de factores protrombóticos de base genética (factor V Leiden y mutación 1120210 de la protrombina), comprobando una elevada prevalencia de factor V Leiden (36 por ciento) en aquellos que tenían antecedentes de manifestaciones trombóticas, 10 veces superior a la de la población normal en nuestra Área de Salud (4 por ciento), y similar a la de pacientes no nefrológicos con enfermedad tromboembólica venosa. La situación de portador de esta mutación podría ser un factor determinante en la aparición de trombosis, en asociación con otros trastornos adquiridos de la coagulación que tienen lugar en estos pacientes. Por lo que respecta a la mutación 11202,0 de la protrombina estuvo presente sólo en un caso aunque en ausencia de manifestaciones de enfermedad tromboembólica venosa. Creemos aconsejable, por tanto, la determinación de la resistencia a la proteína C activada y su genotipo más frecuente, el factor V Leiden, en enfermos con glomerulonefritis con vistas a posibles actuaciones de profilaxis tromboembólica (AU)


Assuntos
Pessoa de Meia-Idade , Adulto , Idoso , Masculino , Feminino , Humanos , Trombose , Prevalência , Mutação , Protrombina , Resistência à Proteína C Ativada , Fator V , Glomerulonefrite
15.
Perit Dial Int ; 19 Suppl 2: S161-6, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10406511

RESUMO

Clinical effects of recombinant human erythropoietin (rHuEPO) such as thrombosis, convulsions, hyperviscosity, hypertension, and angiogenic effect in culture cells have been described. We studied the rHuEPO effect on endothelial damage markers and endothelial function markers: tissue-type plasminogen activator (t-PA), nitrate (NO3), thrombomodulin (TM), and von Willebrand factor (vWF). Twenty-six peritoneal dialysis patients treated with rHuEPO and 19 controls were included. The study design for rHuEPO patients consisted of four periods: long-term treatment (rHuEPO-1); 2 months of withdrawal (rHuEPO-2); and 4 months on 5000 IU/week rHuEPO subcutaneously, with markers being measured after 2 months (rHuEPO-3) and after 4 months (rHuEPO-4). After 2 months of rHuEPO withdrawal, a decrease in hemoglobin level appeared (11+/-1.8 g/dL to 9.2+/-1.5 g/dL, p < 0.01). After rHuEPO reintroduction, this value reached 10.6+/-1.5 g/dL at two months, and 11.1+/-1.4 g/dL at four months. A significant increase in t-PA ratio was observed from two months without rHuEPO to two months on rHuEPO, returning to previous values after four months. Similarly, TM increased for patients with creatinine clearances (CrC) < 5 mL/min. No changes in the higher-than-normal plasma vWF levels were found during the various periods. A statistically significant lower value was found in controls compared with rHuEPO-4 patients. A statistically significant increase in NO3 levels was observed in the pre-venous occlusion (VO) test immediately after the re-introduction of rHuEPO. This increment returned to prior values four months after rHuEPO was reintroduced. Our results show that rHuEPO treatment causes an increase in some endothelial damage markers (TM, t-PA) and modifies endothelial function markers (t-PA ratio, NO3). These changes might favor thrombosis and atherosclerosis.


Assuntos
Endotélio Vascular/metabolismo , Eritropoetina/farmacologia , Diálise Peritoneal , Adulto , Idoso , Idoso de 80 Anos ou mais , Arteriosclerose/fisiopatologia , Endotélio Vascular/fisiopatologia , Eritropoetina/efeitos adversos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Nitratos/sangue , Óxido Nítrico/metabolismo , Proteínas Recombinantes , Trombomodulina/sangue , Ativador de Plasminogênio Tecidual/sangue , Fator de von Willebrand/análise
17.
J Laparoendosc Adv Surg Tech A ; 8(6): 417-23, 1998 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-9916595

RESUMO

The aim of this study was to examine the fibrinolytic activity in laparoscopic cholecystectomy (LC) to determine whether changes occur that might indicate a greater risk of thrombosis. The study was carried out in 20 patients who had undergone laparoscopic surgery for cholelithiasis without complications. The average age was 59.4 years (34-77 years). Seventy-five percent were women. The mean operating time was 70 minutes (35-120 minutes). Pneumoperitoneum at 14 mm Hg was maintained in all patients, and they were in 30 degrees reverse Trendelenburg position. Postoperative mobilization was obtained before 24 hours, and patients were discharged 48 hours after surgery. The control group was composed of 12 patients, evenly distributed by age, sex, and length of surgery, who had undergone Bassini herniorrhaphy without complications or relapses. The following hemostatic parameters were studied: plasma fibrinolytic activity (PFA), euglobulin fibrinolytic activity (EFA), tissue-type plasminogen activator (t-PA), fast-acting plasminogen activator inhibitor-1 (PAI-1), and D-dimer (D-D). Samples were obtained at the following times: (1) under basal conditions the day before surgery, (2) preoperatively, (3) at the end of surgery, (4) 24 hours after surgery, and (5) on the seventh day following surgery. No patient had clinical manifestations of thromboembolic disease immediately after surgery or during an average follow-up period of 16 months (range 15-18 months). Analysis of the results of global fibrinolysis showed that fibrinolytic activity was enhanced only in the postoperative period (third sample) of the LC patients. The fraction of euglobulins enhances fibrinolytic activity in both groups in the third sample with regard to the other determinations; the LC patients showed a higher degree of significance (p<0.005). A significant increase of postoperative t-PA in both groups was found, being more significant in the LC group (p<0.005). In the PAI-1 values, no significant differences existed between either determinations or groups. A significant increase in D-dimer (p<0.05) occurred in the immediate postoperative period (third sample) and 24 hours later (fourth sample), returning to normal basal values on the seventh day. No significant differences were found between the two groups. These results seem to indicate that LC produces an increase in the fibrinolytic activity in plasma as a result of the liberation of tissue plasminogen activator from the venous endothelium, which could indicate hypocoagulability during the immediate postoperative period and, therefore, signify less thrombotic risk for patients undergoing this procedure.


Assuntos
Colecistectomia Laparoscópica/efeitos adversos , Fibrinólise/fisiologia , Trombose/etiologia , Adulto , Idoso , Antifibrinolíticos/metabolismo , Estudos de Casos e Controles , Feminino , Produtos de Degradação da Fibrina e do Fibrinogênio/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade , Inibidor 1 de Ativador de Plasminogênio/sangue , Fatores de Risco , Ativador de Plasminogênio Tecidual/sangue
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