Effect of high-energy mechanical milling on the physicochemical and rheological properties of chayotextle (Sechium edule Sw.) starch.

This work evaluates the effect of high-energy mechanical milling time (7 levels, 20-80 min) on amylose content, crystallinity pattern, temperature and gelatinization enthalpy, morphology, and rheological properties of chayotextle (Sechium edule Sw.) starch. After 30 min of milling, granular structure was affected, and amylose values were the highest while crystallinity and gelatinization enthalpy decreased significantly. These changes allowed to obtain gels with viscoelastic properties where the elastic character (Ç´) prevailed upon the viscous modulus (Ǵ́). Native starch showed Tan δ values of 0.6, increased significantly (0.9) after 30 min of milling due to the surge in linear chains (amylose) and loss of granular structure. Native and modified starches showed high dependence on cutting or shear speed, presenting a non-Newtonian behavior (reofluidizers). These results indicate that mechanical grinding is an alternative to obtain modified starches with applications in the food industry.

The effectiveness of antioxidant vitamins C and E in reducing myocardial infarct size in patients subjected to percutaneous coronary angioplasty (PREVEC Trial): study protocol for a pilot randomized double-blind controlled trial.

BACKGROUND: Acute myocardial infarction (AMI) is the leading cause of mortality worldwide. Oxidative stress has been involved in the ischemia-reperfusion injury in AMI. It has been suggested that reperfusion accounts for up to 50% of the final size of a myocardial infarct, a part of the damage likely to be prevented.Therefore, we propose that antioxidant reinforcement through vitamins C and E supplementation should protect against the ischemia-reperfusion damage, thus decreasing infarct size.The PREVEC Trial (Prevention of reperfusion damage associated with percutaneous coronary angioplasty following acute myocardial infarction) seeks to evaluate whether antioxidant vitamins C and E reduce infarct size in patients subjected to percutaneous coronary angioplasty after AMI. METHODS/DESIGN: This is a randomized, 1:1, double-blind, placebo-controlled clinical trial.The study takes place at two centers in Chile: University of Chile Clinical Hospital and San Borja Arriarán Clinical Hospital.The subjects will be 134 adults with acute myocardial infarction with indication for percutaneous coronary angioplasty.This intervention is being performed as a pilot study, involving high-dose vitamin C infusion plus oral administration of vitamin E (Vitamin-treatment group) or placebo (Control group) during the angioplasty procedure. Afterward, the Vitamin-treatment group receives oral doses of vitamins C and E, and the Control group receives placebo for 84 days after coronary angioplasty.Primary outcome is infarct size, assessed by cardiac magnetic resonance (CMR), measured 6 and 84 days after coronary angioplasty.Secondary outcomes are ejection fraction, measured 6 and 84 days after coronary angioplasty with CMR, and biomarkers for oxidative stress, antioxidant status, heart damage, and inflammation, which will be measured at baseline, at the onset of reperfusion, 6 to 8 hours after revascularization, and at hospital discharge. DISCUSSION: The ischemia-reperfusion event occurring during angioplasty is known to increase myocardial infarct size. The cardioprotective benefits of high doses of vitamin C combined with vitamin E have not been fully explored. The PREVEC Trial seeks to determine the suitability of the therapeutic use of vitamins C and E against the reperfusion damage produced during angioplasty.Patient recruitment opened in February 2013. The trial is scheduled to end in March 2016. TRIAL REGISTRATION: ISRCTN56034553.

Costo-efectividad de reemplazo valvular aórtico percutáneo vs terapia conservadora en la estenosis aórtica de muy alto riesgo en un centro terciario chileno / Cost-effectiveness of trans aortic valve replacement vs. conservative treatment in high-risk patients with severe aortic stenosis in a referral hospital center in Santiago, Chile

Introducción: El objetivo fue evaluar la costo-efectividad del reemplazo valvular aórtico percutáneo (RVAP) contra terapia conservadora (TC) en pacientes con estenosis aórtica (EA) severa de muy alto riesgo, en un centro de derivación. Métodos: Los pacientes derivados entre Enero 2013 y Septiembre 2014, considerados de muy alto riesgo y candidatos a RVAP fueron incluidos. El costo de los recursos usados, de las readmisiones y la sobrevida fueron obtenidos para determinar el tiempo de vida ganado y la relación incremental de costo-efectividad (RICE) del RVAP Resultados: El grupo estudiado quedó compuesto por 39 pacientes, con edad promedio 82±7 años, más frecuentemente mujeres (74.4%), con elevado perfil de riesgo (STS score 11.4±5.6). Diecisiete pacientes (43.6%) fueron sometidos a RVAP y 22 (56.4%) a TC. Durante el seguimiento se registraron 25 rehospitalizaciones en el grupo de TC, a un costo promedio de $4.195.073 por paciente (7,027 dólares). Todos los pacientes sometidos a RAVP recibieron con éxito una prótesis Sapien XT y fueron egresados vivos. El costo promedio estimado del RVAP fue $20.000.000 (33,500 dólares). La sobrevida media fue de 54.5% (10 eventos) en grupo TC contra 94.1% (una muerte) en el grupo RVAP [285±204 días/seguimiento] (p<0.001). Así se pudo estimar que RVAP se asoció a un incremento de vida de al menos un año, lo cual resultó en una RICE de 26,470 dólares/año de vida ganado. Conclusión: El RAVP resultó costo-efectivo comparado con la TC en pacientes portadores de EA severa de muy alto riego tratados en la realidad de un centro de derivación nacional.

Aim: to evaluate cost-effectiveness of Transcatheter Aortic Valve Replacement (TAVR) compared to conservative treatment in patients with very high risk severe aortic stenosis (AS) referred to a tertiary center in Santiago, Chile Methods: Patients with high surgical risk and severe AS referred between January 2013 and September 2014 were included. Cost of resources, readdmissions, life-years gained and incremental cost-effectiveness of TAVI were calculated Results: Thirty-nine patients were finally included. Mean age was 82±7 years old, more commonly women (74%) with a mean STS score of 11.4±5.6 that confirmed their high-risk. Seventeen patients (43.6%) had TAVR and 22 (56.4%) underwent conventional medical therapy. All patients in the TAVR group - treated with Sapien XT® device - survived the procedure and were discharged alive. Mean cost of the procedure was approximately US$ 33,500. After a mean follow-up period of 285±204 days, mean survival rate in the control group was 54.5% (10 deaths) as compared to 94.1% in the TAVR group (1 death, p<0.001). Therefore, a gain of al least one year was obtained with TAVR resulting in an incremental cost effectiveness of US$ 26.470 per year of life gained. Conclusion: TAVR resulted costly-effective compared to conventional therapy in patients with severe AS and high surgical risk in a Chilean referral center.

Complicaciones cardiovasculares por uso de cocaína / Cardiovascular complications due to cocaine

La cocaína es la segunda droga ilegal de mayor consumo en Chile, ya sea como clorhidrato o como pasta base de cocaína. Hemos reportado que el 6 por ciento de los pacientes que ingresaron con Infarto Agudo del Miocardio con supradesnivel del ST (IAMSDST) declararon haber consumido cocaína en la semana previa al evento y la cifra real podría ser mayor. Los efectos cardiovasculares de la cocaína son causados por la inhibición de la recaptura de la noradrenalina en las terminaciones simpáticas, causando vasoespasmo, trombosis coronaria, cardiotoxicidad y aumento del consumo de O2 por taquicardia e hipertensión arterial. Los pacientes con IAM secundario al uso de cocaína son con frecuencia jóvenes que han consumido cocaína en las últimas 24 horas. El diagnóstico de isquemia o infarto en estos pacientes es difícil; el electrocardiograma puede no ser específico hasta en el 60 por ciento delos casos. Se deben utilizar troponinas como marcadores de necrosis, pues las CK-MB dan falsos positivos. El tratamiento incluye hospitalización, benzodiazepinas, morfina IV, nitratos, calcioantagonistas y oxígeno. Debe evitarse el uso de betabloqueadores, porque aumentan la vasoconstricción al liberar el tono a adrenérgico. Ante un IAMSDST, los trombolíticos deben ser usados con precaución, pues se ha reportado una mayor incidencia de hemorragia cerebral. La mejor terapia de reperfusión coronaria en estos casos es la angioplastía primaria.

Cocaine is the second most commonly used drug of abuse in Chile. We reported that 6 percent of patients with STEMI have used cocaine during the week previous to the event, number that could be higher. Cocaine inhibits catecholamine reuptake, resulting in a hyperadrenergic state, which may induce vasospasm, coronary thrombosis, cardiotoxicity, increased myocardial O2 consumption and severe hypertension. Patients with cocaine induced chest pain are frequently young men that had consumed the drug during the last 24 hours. The ECG is specific only in about 60 percent of cases. Troponins should be used to confirm AMI; CK-MB may give false positive results. Treatment of cocaine induced chest pain includes hospitalization, benzodiazepines, nitroglycerin, calcium channel blockers, IV morphine and O2. beta-blockers should not be used because they could increase vasospasm, due to unopposed alpha adrenergic tone. When STEMI is diagnosed, primary angioplasty is the preferred reperfusion method. Thrombolysis is not a first option due to increased rates of intracerebral hemorrhage in cocaine users.