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1.
Comput Biol Med ; 44: 44-56, 2014 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-24377688

RESUMEN

Magnetic fields have been shown to achieve excellent fabrication control and manipulation of conductive bio-polymer characteristics. To simulate magnetohydrodynamic effects on non-Newtonian electro-conductive bio-polymers (ECBPs) we present herein a theoretical and numerical simulation of free convection magneto-micropolar biopolymer flow over a horizontal circular cylinder (an "enrobing" problem). Eringen's robust micropolar model (a special case of the more general micro-morphic or "microfluid" model) is implemented. The transformed partial differential conservation equations are solved numerically with a powerful and new code based on NSM (Network Simulation Method) i.e. PSPICE. An extensive range of Hartmann numbers, Grashof numbers, micropolar parameters and Prandtl numbers are considered. Excellent validation is also achieved with earlier non-magnetic studies. Furthermore the present PSPICE code is also benchmarked with an implicit tridiagonal solver based on Nakamura's method (BIONAK) again achieving close correlation. The study highlights the excellent potential of both numerical methods described in simulating nonlinear biopolymer micro-structural flows.


Asunto(s)
Biopolímeros/química , Simulación por Computador , Conductividad Eléctrica , Campos Magnéticos , Modelos Químicos
2.
Heart ; 95(18): 1483-8, 2009 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-19451141

RESUMEN

OBJECTIVES: To identify the therapeutic regimens used at discharge in patients receiving oral anticoagulant therapy (OAT) who undergo stenting percutaneous coronary intervention and stent implantation (PCI-S), and to assess the safety and efficacy associated with different therapeutic regimens according to thromboembolic risk. DESIGN: A prospective multicentre registry. SETTING: In hospital, after discharge and follow-up by telephone call. PATIENTS AND METHODS: 405 patients (328 male/77 female; mean (SD) age 71 (9) years) receiving OAT who underwent PCI-S between November 2003 and June 2006 from nine catheterisation laboratories of tertiary care teaching hospitals in Spain and one in the United Kingdom were included. RESULTS: Three therapeutic regimens were identified at discharge: triple therapy (TT) -- that is, any anticoagulant (AC) plus double antiplatelet therapy (DAT; 278 patients (68.6%); AC and a single antiplatelet (AC+AT; 46 (11.4%)) and DAT only (81 (20%)). At 6 months, patients receiving TT showed the greatest rate of bleeding events. No patients receiving DAT at low thromboembolic risk presented a bleeding event (14.8% receiving TT, 11.8% receiving AC+AT and 0% receiving DAT, p = 0.033) or cardiovascular event (6.7% receiving TT, 0% receiving AC+AT and 0% receiving DAT, p = 0.126). The combination of AC+AT showed the worst rate of adverse events in the whole cohort, especially in patients at moderate-high thromboembolic risk. CONCLUSIONS: In patients receiving OAT, TT was the most commonly used regimen after PCI-S. DAT was associated with the lowest rate of bleeding events and a similar efficacy to TT in patients at low thromboembolic risk. TT should probably be restricted to patients at moderate-high thromboembolic risk.


Asunto(s)
Anticoagulantes/uso terapéutico , Enfermedad Coronaria/terapia , Inhibidores de Agregación Plaquetaria/uso terapéutico , Stents , Anciano , Angioplastia Coronaria con Balón/métodos , Enfermedad Crónica , Clopidogrel , Supervivencia sin Enfermedad , Quimioterapia Combinada , Femenino , Hemorragia/inducido químicamente , Heparina de Bajo-Peso-Molecular/uso terapéutico , Humanos , Masculino , Estudios Prospectivos , Sistema de Registros , Tromboembolia/prevención & control , Ticlopidina/análogos & derivados , Ticlopidina/uso terapéutico , Resultado del Tratamiento , Warfarina/uso terapéutico
6.
Eur Heart J ; 23(8): 633-40, 2002 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-11969278

RESUMEN

AIMS: To assess the safety of direct coronary stenting, its influence on costs, duration of the procedure, radiation exposure, clinical outcome and angiographic restenosis. METHODS AND RESULTS: We randomized 416 patients (446 lesions) to direct stent implant or stent implant following balloon pre-dilation. Patients >75 years old, heavily calcified lesions, bifurcations, total occlusions, left main lesions and very tortuous vessels were excluded. Direct stenting was successful in 217/224 lesions (96.8%). No single loss or embolization of the stent occurred. All stents in the group with pre-dilation were effectively deployed. The immediate post-procedure angiographic results were similar with both techniques. Fluoroscopy and procedural time were significantly lower in direct stenting (6.4+/-0.3 and 21+/-0.9 min) than in pre-dilated stenting (9.1+/-0.4 and 27.5+/-1.1 min) (P>0.001). Major adverse cardiac events during hospitalization were one in direct and four in pre-dilated stenting (P=0.05) but there were no significant differences at follow-ups at 1, 6 and 12 months between the two groups. Angiographic reevaluation at 6 months was performed in 94% of the cases. Restenosis rate was 16.5% in direct stenting and 14.3% in pre-dilated stenting (P=ns). CONCLUSIONS: Direct stenting is as safe as pre-dilated stenting in selected coronary lesions. Acute angiographic results are similar but procedural costs, duration of the procedure and radiation exposure are lower in direct stenting. Overall success rate, mid-term clinical outcome and restenosis are similar with both techniques.


Asunto(s)
Angioplastia Coronaria con Balón , Vasos Coronarios/cirugía , Stents , Adulto , Anciano , Implantación de Prótesis Vascular , Angiografía Coronaria , Puente de Arteria Coronaria , Reestenosis Coronaria/etiología , Reestenosis Coronaria/mortalidad , Estenosis Coronaria/complicaciones , Estenosis Coronaria/mortalidad , Estenosis Coronaria/terapia , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Complicaciones Posoperatorias/etiología , Complicaciones Posoperatorias/mortalidad , Estudios Prospectivos , España , Análisis de Supervivencia , Factores de Tiempo , Resultado del Tratamiento
7.
Pflugers Arch ; 442(5): 662-7, 2001 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-11512021

RESUMEN

This study was conducted to determine the effects of triiodothyronine (T3) and bovine growth hormone (bGH) on the expression of glucose transporter-2 (GLUT-2) and of glucokinase (GK) from pancreatic islets of fetal and adult rats. Incubation of both sets of pancreatic islets with T3 did not modify GLUT-2 mRNA levels, but did reduce the content of GLUT-2 protein, while it reduced the expression of GK mRNAs in fetal and adult pancreatic islets. Treatment of fetal and adult pancreatic islets with 1 microg/ml bGH did not alter the expression of GLUT-2 mRNAs, but significantly increased GLUT-2 protein levels in adult islets by 50%. Also, bGH had no effect on the GK mRNA content of fetal and adult pancreatic islets whereas, in contrast, there was a significant reduction in the amount of GK protein in fetal islets cultured with that hormone but not in those corresponding to adult rats. These findings suggest that T3 and bGH are able to modulate the expression of GLUT-2 and GK mRNAs and proteins in pancreatic islets in a manner different from that in the liver, as previously reported by others. In addition, both hormones produced different responses in fetal and in adult pancreatic islets.


Asunto(s)
Expresión Génica/efectos de los fármacos , Glucoquinasa/genética , Hormona del Crecimiento/farmacología , Islotes Pancreáticos/fisiología , Proteínas de Transporte de Monosacáridos/genética , Triyodotironina/farmacología , Factores de Edad , Animales , Animales Recién Nacidos , Bovinos , Técnicas de Cultivo , Femenino , Glucoquinasa/metabolismo , Transportador de Glucosa de Tipo 2 , Islotes Pancreáticos/citología , Islotes Pancreáticos/efectos de los fármacos , Islotes Pancreáticos/embriología , Masculino , Proteínas de Transporte de Monosacáridos/metabolismo , Embarazo , ARN Mensajero/genética , ARN Mensajero/metabolismo , Ratas , Ratas Wistar
8.
Rev Esp Cardiol ; 54(6): 679-84, 2001 Jun.
Artículo en Español | MEDLINE | ID: mdl-11412773

RESUMEN

BACKGROUND AND OBJECTIVE: Octogenarian patients with unstable angina are usually managed more conservatively despite having a worse prognosis. Studies of balloon angioplasty in the elderly have demonstrated a higher incidence of adverse events but the new advances (mainly stenting) have improved the results. We evaluated the efficacy and safety of an invasive approach in octogenarians with unstable angina. PATIENTS AND METHOD: From January 1996 to October 1999, 100 patients at least 80 years old with unstable angina were admitted to our unit and among these, 74 (74%) underwent percutaneous revascularization. We evaluated immediate results, in-hospital events and clinical follow-up. RESULTS: A total of 145 lesions were treated in 74 patients. The stent implantation rate was 79%. The success rate was 92%. Two patients died during hospitalization due to cardiac causes and 1 patient had a non-Q infarction. At follow-up, 24 +/- 12 months (range: 4 -50 months) 14 patients died (19.4%). New revascularization was performed in 10 patients (13.5%), 9 with PTCA and 1 with surgery. The survival rate free of death and infarction in the first year was 89.2%. At the end of follow-up 58 patients were alive (78.4%), 45 asymptomatic and 13 had stable angina, class I or II. CONCLUSIONS: The results of stent implantation in octogenarians were good with a 92% procedural success. Ninety-six percent of patients were free of death and infarction during hospitalization and 78.4% of the patients remained alive, most of them asymptomatic at the end of follow-up.


Asunto(s)
Angina Inestable/cirugía , Factores de Edad , Anciano , Anciano de 80 o más Años , Procedimientos Quirúrgicos Cardíacos/métodos , Femenino , Estudios de Seguimiento , Humanos , Masculino , Factores de Riesgo
10.
Yeast ; 18(4): 323-4, 2001 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-11223941

RESUMEN

In this paper we compare the sequence of the gene HSP150/PIR2, independently determined by two different groups, with that present in the yeast database as YJL159w, determined within the Yeast Sequencing Project. Although YJL159w is believed to encode Hsp150/Pir2, there are important differences between the amino acid sequence coded by this ORF and that of HSP150/PIR2. To find out if this divergence is due to strain polymorphism or to a possible sequencing error, we have analysed the diverging zone of this ORF in three strains and have found it entirely consistent with the sequence reported as HSP150/PIR2, concluding that the divergence is probably due to a sequencing error in YJL159w.


Asunto(s)
Genes Fúngicos , Glicoproteínas , Proteínas de Choque Térmico/genética , Proteínas de Saccharomyces cerevisiae , Saccharomyces cerevisiae/genética , Artefactos , Secuencia de Bases , Bases de Datos Factuales , Proteínas Fúngicas/genética , Datos de Secuencia Molecular , Secuencias Repetitivas de Aminoácido
11.
Eur J Biochem ; 268(3): 514-20, 2001 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-11168389

RESUMEN

The expression of glucagon-like peptide-1 (GLP-1) receptor and the effects of GLP-1-(7-36) amide (t-GLP-1) on glucose metabolism and insulin release by pancreatic islets during rat development were studied. GLP-1 receptor mRNA was found in significant amounts in pancreatic islets from all age groups studied, GLP-1 receptor expression being maximal when pancreatic islets were incubated at physiological glucose concentration (5.5 mM), but decreasing significantly when incubated with either 1.67 or 16.7 mM glucose. Glucose utilization and oxidation by pancreatic islets from fetal and adult rats rose as a function of glucose concentration, always being higher in fetal than in adult islets. The addition of t-GLP-1 to the incubation medium did not modify glucose metabolism but gastric inhibitory polypeptide and glucagon significantly increased glucose utilization by fetal and adult pancreatic islets at 16.7 mM glucose. At this concentration, glucose produced a significant increase in insulin release by the pancreatic islets from 10-day-old and 20-day-old suckling rats and adult rats, whereas those from fetuses showed only a significant increase when glucose was raised from 1.67 to 5.5 mM. t-GLP-1 elicited an increase in insulin release by pancreatic islets from all the experimental groups when the higher glucose concentrations were used. Our findings indicate that GLP-1 receptors and the effect of t-GLP-1 on insulin release are already present in the fetus, and they therefore exclude the possibility that alterations in the action of t-GLP-1 are responsible for the unresponsiveness of pancreatic beta cells to glucose in the fetus, but stimulation of t-GLP-1 release by food ingestion in newborns may partially confer glucose competence on beta cells.


Asunto(s)
Glucagón/farmacología , Insulina/metabolismo , Islotes Pancreáticos/metabolismo , Fragmentos de Péptidos/farmacología , Precursores de Proteínas/farmacología , Receptores de Glucagón/biosíntesis , Factores de Edad , Animales , Southern Blotting , ADN Complementario/metabolismo , Relación Dosis-Respuesta a Droga , Femenino , Péptido 1 Similar al Glucagón , Receptor del Péptido 1 Similar al Glucagón , Glucosa/farmacología , Secreción de Insulina , Islotes Pancreáticos/embriología , Masculino , Reacción en Cadena de la Polimerasa , ARN Mensajero/metabolismo , Ratas , Ratas Wistar , Factores de Tiempo
14.
FEMS Yeast Res ; 1(3): 241-5, 2001 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-12702350

RESUMEN

Here we present evidence that Hsp150/Pir2, a member of the Pir family of cell wall proteins, can be extracted from the purified cell walls of Saccharomyces cerevisiae by treatment with beta-mercaptoethanol, demonstrating that at least part of this protein is attached to the cell wall through disulfide bridges. We also present evidence that Pir4, another member of this family, is partly secreted to the growth medium. Finally we propose a hypothesis to explain the relationship between the differently localized forms of particular members of the Pir family of cell wall proteins.


Asunto(s)
Pared Celular/metabolismo , Disulfuros/química , Proteínas Fúngicas/metabolismo , Glicoproteínas , Proteínas de Choque Térmico/metabolismo , Proteínas de Saccharomyces cerevisiae , Saccharomyces cerevisiae/metabolismo , Proteínas Fúngicas/genética , Proteínas de Choque Térmico/genética , Mercaptoetanol/farmacología
15.
Am J Cardiol ; 85(3): 327-32, 2000 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-11078301

RESUMEN

Stent restenosis constitutes a therapeutic challenge affecting an increasing number of patients. Conventional angioplasty and debulking techniques are currently used in these patients. However, the potential role of a second stent implantation in this setting (stenting the stent) remains unknown. Therefore, 65 consecutive patients (12 women, aged 62 +/- 11 years) undergoing stent implantation (42 elective and 23 unplanned) for the treatment of in-stent restenosis (diffuse [> 10 mm] in 39 [60%]) were studied. Angiographic success was obtained in all patients. Three patients developed hospital complications: 1 died from refractory heart failure and 2 suffered non-Q-wave myocardial infarctions. During follow-up (mean 17 +/- 11 months) 1 patient died (noncardiac cause) and only 9 (14%) required target vessel revascularization. Kaplan-Meier event-free survival (freedom from death, myocardial infarction, and target vessel revascularization) at 1 year was 84%. Using Cox analysis, patients with unstable symptoms, a short time to stent restenosis, nonelective stenting, and B2-C lesions tended to have poorer prognosis. After adjustment, nonelective stenting was associated (adjusted RR 2.9, 95% confidence interval [CI] 0.82 to 10.3, p = 0.09) with an adverse clinical outcome. On quantitative angiography (core lab) restenosis was found in 13 of 43 patients (30%) (75% of those eligible). Logistic regression analysis identify restenosis length (adjusted RR 1.43, 95% CI 1.04 to 2.14, p = 0.04), and time to restenosis (adjusted RR 0.67, 95% CI 0.47 to 0.94, p = 0.01) as the only independent predictors of recurrent restenosis. Thus, repeat coronary stenting is a safe and efficacious strategy for the treatment of patients with in-stent restenosis. Both elective and nonelective stenting provide excellent initial results. The long-term clinical and angiographic outcome of these patients is also favorable.


Asunto(s)
Angiografía Coronaria , Oclusión de Injerto Vascular/mortalidad , Oclusión de Injerto Vascular/cirugía , Revascularización Miocárdica , Stents , Supervivencia sin Enfermedad , Femenino , Estudios de Seguimiento , Humanos , Modelos Logísticos , Masculino , Persona de Mediana Edad , Modelos de Riesgos Proporcionales , Reoperación , España/epidemiología
16.
Rev Esp Cardiol ; 53(10): 1335-41, 2000 Oct.
Artículo en Español | MEDLINE | ID: mdl-11061714

RESUMEN

INTRODUCTION AND OBJECTIVES: Direct stenting is a safe and feasible technique in selected lesions yielding excellent angiographic results. However, there are no studies providing intravascular ultrasonographic examination after direct stenting. The aim of this study was to evaluate direct stent expansion with ultrasonography and to know whether there are differences in the results based on lesion types. METHODS: Patients with amenable lesions for direct stenting were enrolled; including patients with no occlusion, no calcification, no significant tortuosity or angulation, a length 15 mm and a reference lumen diameter 2.5 mm. Intravascular ultrasonography was performed after stent implantation. The ultrasonographic criteria for optimal expansion were: complete apposition and a minimal intrastent lumen area > 80% of the average reference luminal area and 90% of the distal reference lumen area. RESULTS: We included 40 patients (50 lesions). The final angiographic result was good in all the patients but in one case an additional stent was used due to dissection. The ultrasonographic examination did not show significant differences between type A and B lesions. Optimal expansion was achieved in 14/21 (66%) of type A lesions and 17/29 (58%) of type B lesions (p = 0.5). The balloon/artery ratio was the only factor significantly related to ultrasonographic results. When this ratio was 1.1-1.2 (25 cases), 76% of the stents were optimally expanded and when the ratio was < 1. 1 (25 cases) only in a 48% an optimal result was achieved (p < 0.05). CONCLUSIONS: Direct stenting in selected lesions provides ultrasonographic results comparable to those expected with conventional stenting and these results could be even improved if a balloon artery ratio 1.1-1.2 is used. Taking into consideration the selection criteria the differences observed between lesion types A and B are not significant.


Asunto(s)
Enfermedad Coronaria/diagnóstico por imagen , Enfermedad Coronaria/cirugía , Stents , Ultrasonografía Intervencional , Femenino , Humanos , Masculino , Persona de Mediana Edad
18.
Am J Cardiol ; 85(8): 1028-30, A8, 2000 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-10760351

RESUMEN

The present study shows that direct stent implantation without predilatation in selected lesions provides angiographic and ultrasonographic results that could be comparable to those expected with conventional stenting. These results may even safely improve if a balloon-artery ratio of 1.1 to 1.2 is used in combination with implantation pressures of 12 to 16 atm.


Asunto(s)
Enfermedad Coronaria/terapia , Stents , Ultrasonografía Intervencional , Enfermedad Coronaria/diagnóstico por imagen , Dilatación , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Implantación de Prótesis/métodos
20.
J Am Coll Cardiol ; 34(5): 1498-506, 1999 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-10551699

RESUMEN

OBJECTIVE: The purpose of this study was to test the hypothesis that stent implantation in de novo coronary artery lesions would result in lower restenosis rates and better long-term clinical outcomes than balloon angioplasty. BACKGROUND: Placement of an intracoronary stent, as compared with balloon angioplasty, has proven to reduce the rate of restenosis. However, the long-term clinical benefit of stenting over angioplasty has not been assessed in large randomized trials. METHODS: We randomly assigned 452 patients with either stable (129 patients) or unstable (323 patients) angina pectoris to elective stent implantation (229 patients) or standard balloon angioplasty (223 patients). Coronary angiography was performed at baseline, immediately after the procedure and six months later. End points were the rate of restenosis at six months and a composite of death, myocardial infarction (MI) and target vessel revascularization over four years of follow-up. RESULTS: Procedural success rate was achieved in 84% and 95% (balloon angioplasty vs. stent, respectively). The increase in the minimal luminal diameter was greater in the stent group both after the intervention (2.02 +/- 0.6 mm vs. 1.43 +/- 0.6 mm in the angioplasty group; p < 0.0001), and at six-month follow-up (1.98 +/- 0.7 mm vs. 1.63 +/- 0.7 mm; p < 0.001). The corresponding restenosis rates were 22% and 37%, respectively (p < 0.002). After four years, no differences in mortality (2.7% vs. 2.4%) and nonfatal MI (2.2% vs. 2.8%) were found between the stent and the angioplasty groups, respectively. However, the requirement for further revascularization procedures of the target lesions was significantly reduced in the stent group (12% vs. 25% in the angioplasty group; relative risk 0.49, 95% confidence interval 0.32 to 0.75, p = 0.0006); most of the repeat procedures (84%) were carried out within six months of entry into the study. CONCLUSIONS: Patients who received an intracoronary stent showed a lower rate of restenosis than those treated with conventional balloon angioplasty. The benefit of stenting was maintained four years after implantation, as manifested by a significant reduction in the need for repeat revascularization.


Asunto(s)
Angioplastia Coronaria con Balón , Enfermedad Coronaria/terapia , Stents , Anciano , Angiografía Coronaria , Enfermedad Coronaria/diagnóstico por imagen , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Recurrencia , Resultado del Tratamiento
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