Examinando por Autor "Silva, Sandra Y."

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  • Publicación
    Acceso abierto
    Are nutrition-induced epigenetic changes the link between socioeconomic pathology and cardiovascular diseases?
    (2008-07) Lopez-Jaramillo, Patricio; Silva, Sandra Y.; Rodríguez Salamanca, Narella; Durán Hernández, Álvaro-Hernán; Mosquera, Walter; Castillo, Victor R.
    The prevalence of cardiovascular diseases (CVD) and diabetes mellitus type 2 (DM 2) is decreasing in developed countries despite the increase in the percentage of subjects with obesity and other wellrecognized cardiovascular risk factors. In contrast, the recent transition of the economic model experienced by developing countries, characterized by the adoption of a Western lifestyle, that we have named ‘‘socioeconomic pathology,’’ has led to an increase in the burden of CVD. It has been demonstrated that conventional cardiovascular risk factors in developed and developing countries are the same. Why then does the population of developing countries currently have a higher incidence of CVD than that of developed countries if they share the same risk factors? We have proposed the existence of a higher susceptibility to the development of systemic inflammation at low levels of abdominal obesity in the population of developing countries and the consequent endothelial dysfunction, insulin resistance, DM 2, and CVD. In contrast, an important percentage of obese people living in developed countries have a healthy phenotype and low risk of developing CVD and DM 2. Human epidemiologic studies and experimental dietary interventions in animal models have provided considerable evidence to suggest that nutritional imbalance and metabolic disturbances early in life may later have a persistent effect on an adult’s health that may even be transmitted to the next generations. Epigenetic changes dependent on nutrition could be key in this evolutionary health behavior, acting as a buffering system, permitting the adaptation to environmental conditions by silencing or increasing the expression of certain genes.
  • Publicación
    Restringido
    Double blind, randomized controlled trial, to evaluate the effectiveness of a controlled nitric oxide releasing patch versus meglumine antimoniate in the treatment of cutaneous leishmaniasis [NCT00317629]
    (2006-05-15) Silva, Sandra Y.; Rueda, Ligia C.; López Casillas, Marcos; Vélez, Iván D.; Rueda Clausen, Christian F.; Smith, Daniel J.; Muñoz, Gerardo; Mosquera, Hernando; Silva Sieger, Federico Arturo; Buitrago, Adriana; Díaz, Holger; Lopez-Jaramillo, Patricio
    Background: Cutaneous Leishmaniasis is a worldwide disease, endemic in 88 countries, that has shown an increasing incidence over the last two decades. So far, pentavalent antimony compounds have been considered the treatment of choice, with a percentage of cure of about 85%. However, the high efficacy of these drugs is counteracted by their many disadvantages and adverse events. Previous studies have shown nitric oxide to be a potential alternative treatment when administered topically with no serious adverse events. However, due to the unstable nitric oxide release, the topical donors needed to be applied frequently, making the adherence to the treatment difficult. The electrospinning technique has allowed the production of a multilayer transdermal patch that produces a continuous and stable nitric oxide release. The main objective of this study is to evaluate this novel nitric oxide topical donor for the treatment of cutaneous leishmaniasis. Methods and design: A double-blind, randomized, double-masked, placebo-controlled clinical trial, including 620 patients from endemic areas for Leishmaniasis in Colombia was designed to investigate whether this patch is as effective as meglumine antimoniate for the treatment of cutaneous leishmaniasis but with less adverse events. Subjects with ulcers characteristic of cutaneous leishmaniasis will be medically evaluated and laboratory tests and parasitological confirmation performed. After checking the inclusion/exclusion criteria, the patients will be randomly assigned to one of two groups. During 20 days Group 1 will receive simultaneously meglumine antimoniate and placebo of nitric oxide patches while Group 2 will receive placebo of meglumine antimoniate and active nitric oxide patches. During the treatment visits, the medicationswill be daily administered and the presence of adverse events assessed. During the follow-up, the research group will visit the patients at days 21, 45, 90 and 180. The healing process of the ulcer, the health of the participants, recidivisms and/or reinfection will also be assessed. The evolution of the ulcers will be photographically registered. In case that the effectiveness of the patches is demonstrated, a novel and safe therapeutic alternative for one of the most important public health problems in many countries will be available to patients.
  • Publicación
    Restringido
    Double blind, randomized, placebo controlled clinical trial for the treatment of diabetic foot ulcers, using a nitric oxide releasing patch : PATHON
    (2007-09-26) Silva, Sandra Y.; Rueda, Ligia C.; Márquez, Gustavo; López Casillas, Marcos; Smith, Daniel J.; Calderón, Carlos A.; Castillo, Juan C.; Matute, Jaime; Rueda Clausen, Christian F.; Orduz, Arturo; Silva Sieger, Federico Arturo; Kampeerapappun, Piyaporn; Bhide, Mahesh; Lopez-Jaramillo, Patricio
    Background: Diabetes Mellitus constitutes one of the most important public health problems due to its high prevalence and enormous social and economic consequences. Diabetic foot ulcers are one of the chronic complications of diabetes mellitus and constitute the most important cause of non-traumatic amputation of inferior limbs. It is estimated that 15% of the diabetic population will develop an ulcer sometime in their lives. Although novel therapies have been proposed, there is no effective treatment for this pathology. Naturally produced nitric oxide participates in the wound healing process by stimulating the synthesis of collagen, triggering the release of chemotactic cytokines, increasing blood vessels permeability, promoting angiogenic activity, stimulating the release of epidermical growth factors, and by interfering with the bacterial mitochondrial respiratory chain. Topically administered nitric oxide has demonstrated to be effective and safe for the treatment of chronic ulcers secondary to cutaneous leishmaniasis. However, due to their unstable nitric oxide release, the topical donors needed to be applied frequently, diminishing the adherence to the treatment. This difficulty has led to the development of a multilayer polymeric transdermal patch produced by electrospinning technique that guarantees a constant nitric oxide release. The main objective of this study is to evaluate the effectiveness and safety of this novel nitric oxide releasing wound dressing for the treatment of diabetic foot ulcers. Methods and design: A double-blind, placebo-controlled clinical trial, including 100 diabetic patients was designed. At the time of enrollment, a complete medical evaluation and laboratory tests will be performed, and those patients who meet the inclusion criteria randomly assigned to one of two groups. Over the course of 90 days group 1 will receive active patches and group 2 placebo patches. The patients will be seen by the research group at least every two weeks until the healing of the ulcer or the end of the treatment. During each visit the healing process of the ulcer, the patient's health status and the presence of adverse events will be assessed. Should the effectiveness of the patches be demonstrated an alternative treatment would then be available to patients.
  • Publicación
    Acceso abierto
    Hyperinsulinemia is a predictor of new cardiovascular events in colombian patients with a first myocardial infarction
    (2011-04-01) García, Ronald G.; Rincón, Melvin Y.; Arenas, William D.; Silva, Sandra Y.; Reyes, Laura M.; Ruiz, Silvia L.; Ramírez, Fabián; Camacho López, Paul Anthony; Luengas, Carlos; Saaibi, José F.; Balestrini, Sebastián; Morillo, Carlos; Lopez-Jaramillo, Patricio
    Background: Acute Myocardial Infarction (AMI) is one of the main causes of mortality and disability in Colombia. The factors associated to a new event in surviving subjects to a first AMI in our population have not yet been fully identified. Methods: Two hundred and ninety five surviving subjects to a first AMI (58.8±12.6 years) were included in a prospective cohort study between 2000 and 2006. Lipid profile, glycemia and plasma insulin levels were measured. Deaths of cardiovascular origin, a new AMI, unstable angina, heart failure, stroke, new myocardial revascularization or angioplasty were considered new cardiovascular events. Results: The study included 61 (20.6%) women and 234 (79.4%) men. The mean follow up time was 50± 30 months with a 38.9% incidence of new events. Fifty five patients (18.6%) were diabetic. Bi-varied analysis identified as risk factors for a new cardiovascular event the presence of: hypertension, anterior descending coronary artery stenosis, intrahospital cardiac failure, age over 55, low income, lack of education, Killip III–IV, heart rate over 76 bpm, pulse pressure over 80 mm Hg, total cholesterol over 200 mg/dl and insulin over 10 IU/ml. After logistic regression analysis, the log values of insulin remained as the only significant predictor for new cardiovascular events. Conclusions: Hyperinsulinism was the most important factor associated to the occurrence of new cardiovascular events in Colombian patients with AMI, which emphasizes the pivotal role of insulin resistance in the physiopathologic mechanisms of atherosclerosis, especially in undeveloped countries.
  • Publicación
    Restringido
    Leishmaniasis cutánea diseminada. Reporte de dos casos en Santander, Colombia
    (2009-01) Rincón, Melvin Y.; Silva, Sandra Y.; Dueñas, Ruby E.; Lopez-Jaramillo, Patricio
    Leishmaniasis is a zoonosis produced by the transmission of the protozoan leishmania caused by the bite of sand-flies from the Lutzomya specie. Several clinical manifestations present themselves, depending on the infecting strain and the host’s immune response; the most frequent variety is localised cutaneous leishmaniasis. Atypical forms sometimes develop, such as the diffuse variety, in which the number of ulcers is greate than 10, thereby affecting several body areas requiring special considerations in its diagnosis and management. This article reports two cases of patients from endemic areas of Santander suffering from diffuse cutaneous leishmaniasis produced by the L. panamensis strain. Protocols for the active search of this type of case in endemic areas throughout Colombia should be implemented.