Dieting postmenopausal women who want to avoid losing muscle as they lose fat should pay attention to a new University of Illinois study. Adding protein throughout the day not only holds hunger pangs at bay so that dieters lose more weight, it keeps body composition -- the amount of fat relative to muscle -- in better proportion. "A higher-protein weight-loss diet is more protective of muscle," said Ellen Evans, a former U of I associate professor of kinesiology and community health and member of the university's Division of Nutritional Sciences.
Scientists in Evans's Illinois lab wanted to study the way body composition relates to physical function because older women who diet risk losing muscle as well as fat.
"That loss can affect their strength, balance, and how well they perform everyday tasks, such as climbing stairs and getting up out of a chair," said Mina Mojtahedi, a researcher in Evans's laboratory.
The study shows that higher protein intake during weight loss can offset negative effects on muscle mass by maintaining more muscle relative to the amount of weight lost. Women who ate more protein lost 3.9 percent more weight and had a relative gain of 5.8 percent more thigh muscle volume than woman who did not, she said.
"When a woman has less weight to carry, even if she's lost a bit of lean mass in her legs, the effect is that she has better physical function," she said.
It's likely that such women will be better able to maintain their mobility and independence as they age, she added.
In the six-month double-blind study, 31 healthy, postmenopausal obese women were divided into two groups. Each group followed a 1,400-calorie weight-loss diet based on USDA's My Pyramid, but one group received a powdered whey protein supplement in the morning and again in the afternoon or evening; the other received a placebo that contained carbohydrates.
"We believe it's important to eat protein in the morning and through the day so those amino acids are always available. Unfortunately, American women tend not to eat much protein, especially when they're trying to cut calories. But it's easy to add protein powder into a smoothie or eat a high-protein snack and incorporate a healthier diet into a busy lifestyle," she said.
Both groups were encouraged to engage in light exercise (walking and stretching) and given diet education, including examples of healthy daily menus and a scale to measure portion size.
Before and after the study, participants were assessed for strength, balance, and the ability to perform such physical tasks as walking 50 feet, standing up five times from a chair, and lifting a book 12 inches above shoulder height.
Magnetic resonance imaging (MRI) was used at the beginning and end of the study to measure muscle volume of the right thigh, the amount of fat around the thigh, and the amount of fat within the thigh muscle.
In both groups, strength decreased as weight decreased. However, the study suggests that an increase in the amount of muscle relative to fat had beneficial effects on balance and performance, Evans noted.
And, even though weight loss in these older women had a negative effect on strength, their reduced weight helped with other aspects of physical function, she said.
"We hypothesize that more vigorous exercise -- in particular, resistance training -- would preserve even more muscle," she said.
**Source: University of Illinois College of Agricultural, Consumer and Environmental Sciences
11 August 2011
Nueva York impone la educación sexual en primaria y secundaria
Por primera vez en dos décadas, las escuelas públicas de secundaria de la ciudad de Nueva York ofrecerán este próximo curso clases de educación sexual en las que enseñará cómo usar un preservativo y cómo evitar embarazos no deseados y prevenir las enfermedades venéreas. Una coalición de grupos religiosos y conservadores se opuso a la educación sexual en Nueva York en los años ochenta y noventa, y consiguió eliminarla de los temarios de las escuelas públicas. El alcalde Michael Bloomberg la ha reinstaurado, con el argumento de que existe un elevado número de embarazos juveniles no deseados y de contagios de enfermedades venéreas, sobre todo en comunidades desfavorecidas de mayoría hispana o negra. Los alumnos del mayor sistema docente de EE UU (1,1 millones de alumnos y 1.700 centros) deberán estudiar educación sexual dos semestres: entre sexto y séptimo, y entre noveno y décimo; es decir, a partir de los 11 años.
20 de los 50 Estados norteamericanos, junto a la capital federal, incluyen algún tipo de educación sexual en los temarios de las escuelas públicas. Muchos de ellos, sin embargo, lo que hacen es enseñar abstinencia. Eso ha favorecido que, a nivel nacional, haya un millón de embarazos no deseados cada año y que un 25% de alumnos salga de la escuela sin haber recibido educación sobre cómo usar métodos de prevención sexual o cómo evitar la infección de enfermedades como la que provoca el VIH, según cifras del instituto Guttmacher.
En una carta enviada recientemente a los directores de las escuelas públicas de la ciudad, el jefe de educación local, Dennis Walcott, escribió: "Debemos esforzarnos para tener la certeza de que los alumnos de secundaria quedan expuestos a ese tipo de información, tan valiosa, para que aprendan a mantenerse sanos y seguros antes y durante su iniciación al sexo... Creo que el sistema educativo tiene un papel muy importante con respecto a la educación sexual de los niños y sobre las posibles consecuencias de mantener relaciones de riesgo". Para aplacar los ánimos de las organizaciones conservadoras y religiosas -el propio Papa calificó el pasado enero las clases de educación sexual de atentado a la libertad religiosa- el Departamento de Educación neoyorquino ha advertido a los padres de ese cambio en el temario, vigente en otoño, y les ha autorizado a dispensar a sus hijos en los días en que se enseñe sobre métodos anticonceptivos. Deberán acudir, sin embargo, a otras clases, como las de anatomía o reproducción.
Desde hace dos décadas, los institutos de Nueva York reparten condones a los estudiantes que los deseen. Solo a partir de ahora deberán explicarles a esos alumnos por mandato del Gobierno local para qué sirven y cómo se usan.
En España, la educación sexual en la escuela es cuestión de suerte. Los sucesivos Gobiernos han renunciado a imponerla como sí ha ocurrido en otros países como Holanda, así que la enseñanza del sexo se reduce básicamente a contenidos biológicos y algún taller externo. Y esa formación es insuficiente a tenor de los datos, incluso hoy que los alumnos tienen otras fuentes de información. 475 menores de 15 años y otras 14.464 chicas de 15 a 19 años abortaron en nuestro país en 2008 por embarazos no deseados, según el Instituto Nacional de Estadística (INE).
20 de los 50 Estados norteamericanos, junto a la capital federal, incluyen algún tipo de educación sexual en los temarios de las escuelas públicas. Muchos de ellos, sin embargo, lo que hacen es enseñar abstinencia. Eso ha favorecido que, a nivel nacional, haya un millón de embarazos no deseados cada año y que un 25% de alumnos salga de la escuela sin haber recibido educación sobre cómo usar métodos de prevención sexual o cómo evitar la infección de enfermedades como la que provoca el VIH, según cifras del instituto Guttmacher.
En una carta enviada recientemente a los directores de las escuelas públicas de la ciudad, el jefe de educación local, Dennis Walcott, escribió: "Debemos esforzarnos para tener la certeza de que los alumnos de secundaria quedan expuestos a ese tipo de información, tan valiosa, para que aprendan a mantenerse sanos y seguros antes y durante su iniciación al sexo... Creo que el sistema educativo tiene un papel muy importante con respecto a la educación sexual de los niños y sobre las posibles consecuencias de mantener relaciones de riesgo". Para aplacar los ánimos de las organizaciones conservadoras y religiosas -el propio Papa calificó el pasado enero las clases de educación sexual de atentado a la libertad religiosa- el Departamento de Educación neoyorquino ha advertido a los padres de ese cambio en el temario, vigente en otoño, y les ha autorizado a dispensar a sus hijos en los días en que se enseñe sobre métodos anticonceptivos. Deberán acudir, sin embargo, a otras clases, como las de anatomía o reproducción.
Desde hace dos décadas, los institutos de Nueva York reparten condones a los estudiantes que los deseen. Solo a partir de ahora deberán explicarles a esos alumnos por mandato del Gobierno local para qué sirven y cómo se usan.
En España, la educación sexual en la escuela es cuestión de suerte. Los sucesivos Gobiernos han renunciado a imponerla como sí ha ocurrido en otros países como Holanda, así que la enseñanza del sexo se reduce básicamente a contenidos biológicos y algún taller externo. Y esa formación es insuficiente a tenor de los datos, incluso hoy que los alumnos tienen otras fuentes de información. 475 menores de 15 años y otras 14.464 chicas de 15 a 19 años abortaron en nuestro país en 2008 por embarazos no deseados, según el Instituto Nacional de Estadística (INE).
**Publicado en "EL PAIS"
Heart patients could benefit from different drug, study shows
Patients with an irregular heart beat could benefit from a drug that is easier to administer than the current standard treatment. The condition, which is more common with older age and affects about 800,000 people in the UK, can lead to blood clots forming and significantly increases the risk of stroke.
A global study, led by the University of Edinburgh and the Duke University in North Carolina, America, compared the effects of warfarin, the standard treatment to prevent clotting for irregular heartbeats, with the drug rivaroxaban.
Rivaroxaban was found to be as effective as warfarin in reducing the risk of stroke, which can be four to six times higher in patients with irregular heart beats.
Both drugs work by reducing the clotting of the blood but, as a result, this can increase the risk of bleeding. The impact of warfarin can be affected by other medications and diet, and so patients taking it must be closely monitored to ensure they are receiving the correct dose.
Rivaroxaban does not need to be so closely monitored, nor the dose adjusted.
Researchers studied 14,000 patients with irregular heat beats and at risk of stroke -- a condition known as atrial fibrillation -- who were given either warfarin or rivaroxaban.
The study also found that the incidence of bleeding was similar for both drugs. The risk of fatal bleeding on the brain was halved (from 5 per thousand to approx 2 per thousand) among patients taking rivaroxaban.
Atrial fibrillation can affect adults of any age, but is more common as people get older affecting about 10 per cent of over-65s.
Professor Keith Fox, a British Heat Foundation-supported Professor at the University of Edinburgh, said: "We know that about a third of patients eligible for warfarin are not currently receiving it. This may be because they are too frail and may not be able to manage taking the drug appropriately, with the need for blood tests and dosage levels to be monitored closely. This study shows that an alternative drug for patients with irregular heart beats is just as effective while also easier to prescribe and take."
The study is published by the New England Journal of Medicine.
Manesh R. Patel, MD assistant Professor of Medicine at Duke University School of Medicine, said: "Warfarin has been a standard treatment for decades, but requires a rigorous monitoring schedule to ensure therapeutic dosing levels, and is subject to the potential of food and drug interactions that present treatment obstacles for patients and doctors alike. The results of this large global trial have convincingly shown rivaroxaban to be an alternative to warfarin in treating patients with atrial fibrillation and, importantly, with no increase in bleeding."
**Source: University of Edinburgh
A global study, led by the University of Edinburgh and the Duke University in North Carolina, America, compared the effects of warfarin, the standard treatment to prevent clotting for irregular heartbeats, with the drug rivaroxaban.
Rivaroxaban was found to be as effective as warfarin in reducing the risk of stroke, which can be four to six times higher in patients with irregular heart beats.
Both drugs work by reducing the clotting of the blood but, as a result, this can increase the risk of bleeding. The impact of warfarin can be affected by other medications and diet, and so patients taking it must be closely monitored to ensure they are receiving the correct dose.
Rivaroxaban does not need to be so closely monitored, nor the dose adjusted.
Researchers studied 14,000 patients with irregular heat beats and at risk of stroke -- a condition known as atrial fibrillation -- who were given either warfarin or rivaroxaban.
The study also found that the incidence of bleeding was similar for both drugs. The risk of fatal bleeding on the brain was halved (from 5 per thousand to approx 2 per thousand) among patients taking rivaroxaban.
Atrial fibrillation can affect adults of any age, but is more common as people get older affecting about 10 per cent of over-65s.
Professor Keith Fox, a British Heat Foundation-supported Professor at the University of Edinburgh, said: "We know that about a third of patients eligible for warfarin are not currently receiving it. This may be because they are too frail and may not be able to manage taking the drug appropriately, with the need for blood tests and dosage levels to be monitored closely. This study shows that an alternative drug for patients with irregular heart beats is just as effective while also easier to prescribe and take."
The study is published by the New England Journal of Medicine.
Manesh R. Patel, MD assistant Professor of Medicine at Duke University School of Medicine, said: "Warfarin has been a standard treatment for decades, but requires a rigorous monitoring schedule to ensure therapeutic dosing levels, and is subject to the potential of food and drug interactions that present treatment obstacles for patients and doctors alike. The results of this large global trial have convincingly shown rivaroxaban to be an alternative to warfarin in treating patients with atrial fibrillation and, importantly, with no increase in bleeding."
**Source: University of Edinburgh
Red meat linked to increased risk of type 2 diabetes
A new study by Harvard School of Public Health (HSPH) researchers finds a strong association between the consumption of red meat -- particularly when the meat is processed -- and an increased risk of type 2 diabetes. The study also shows that replacing red meat with healthier proteins, such as low-fat dairy, nuts, or whole grains, can significantly lower the risk. The study, led by An Pan, research fellow in the HSPH Department of Nutrition, will be published online in the American Journal of Clinical Nutrition on August 10, 2011 and will appear in the October print edition.
Pan, senior author Frank Hu, professor of nutrition and epidemiology at HSPH, and colleagues analyzed questionnaire responses from 37,083 men followed for 20 years in the Health Professionals Follow-Up Study; 79,570 women followed for 28 years in the Nurses' Health Study I; and 87,504 women followed for 14 years in the Nurses' Health Study II. They also conducted an updated meta-analysis, combining data from their new study with data from existing studies that included a total of 442,101 participants, 28,228 of whom developed type 2 diabetes during the study. After adjusting for age, body mass index (BMI), and other lifestyle and dietary risk factors, the researchers found that a daily 100-gram serving of unprocessed red meat (about the size of a deck of cards) was associated with a 19% increased risk of type 2 diabetes. They also found that one daily serving of half that quantity of processed meat -- 50 grams (for example, one hot dog or sausage or two slices of bacon) -- was associated with a 51% increased risk.
"Clearly, the results from this study have huge public health implications given the rising type 2 diabetes epidemic and increasing consumption of red meats worldwide," said Hu. "The good news is that such troubling risk factors can be offset by swapping red meat for a healthier protein."
The researchers found that, for an individual who eats one daily serving of red meat, substituting one serving of nuts per day was associated with a 21% lower risk of type 2 diabetes; substituting low-fat dairy, a 17% lower risk; and substituting whole grains, a 23% lower risk.
Based on these results, the researchers advise that consumption of processed red meat -- like hot dogs, bacon, sausage, and deli meats, which generally have high levels of sodium and nitrites -- should be minimized and unprocessed red meat should be reduced. If possible, they add, red meat should be replaced with healthier choices, such as nuts, whole grains, low-fat dairy products, fish, or beans.
Worldwide, diabetes has reached epidemic levels, affecting nearly 350 million adults. In the U.S. alone, more than 11% of adults over age 20 -- 25.6 million people -- have the disease, according to the Centers for Disease Control and Prevention. Most have type 2 diabetes, which is primarily linked to obesity, physical inactivity, and an unhealthy diet.
Previous studies have indicated that eating processed red meats increases the risk of developing type 2 diabetes. Risks from unprocessed meats have been less clear. For instance, in 2010, HSPH researchers found no clear evidence of an association between eating unprocessed meats and increased risk for either coronary heart disease or type 2 diabetes, but that study was based on smaller samples than the current study, and the researchers recommended further study of unprocessed meats. Another HSPH study in 2010 linked eating red meat with an increased risk of heart disease -- which is strongly linked to diabetes -- but did not distinguish between processed and unprocessed red meats.
This new study -- the largest of its kind in terms of sample size and follow-up years -- finds that both unprocessed and processed meats pose a type 2 diabetes risk, thus helping to clarify the issue. In addition, this study is among the first to estimate the risk reduction associated with substituting healthier protein choices for red meat.
"Our study clearly shows that eating both unprocessed and processed red meat -- particularly processed -- is associated with an increased risk of type 2 diabetes," said Pan. He noted that the 2010 U.S. dietary guidelines continue to lump red meat together with fish, poultry, eggs, nuts, seeds, beans, and soy products in the "protein foods" group. But since red meat appears to have significant negative health effects -- increased risk of diabetes, cardiovascular disease, and even total mortality, as suggested by several recent studies -- Pan suggested the guidelines should distinguish red meat from healthier protein sources and promote the latter instead.
Support for the study was provided by the National Institutes of Health's National Institute of Diabetes and Digestive and Kidney Diseases and the National Heart, Lung, and Blood Institute.
**Source: Harvard School of Public Health
Pan, senior author Frank Hu, professor of nutrition and epidemiology at HSPH, and colleagues analyzed questionnaire responses from 37,083 men followed for 20 years in the Health Professionals Follow-Up Study; 79,570 women followed for 28 years in the Nurses' Health Study I; and 87,504 women followed for 14 years in the Nurses' Health Study II. They also conducted an updated meta-analysis, combining data from their new study with data from existing studies that included a total of 442,101 participants, 28,228 of whom developed type 2 diabetes during the study. After adjusting for age, body mass index (BMI), and other lifestyle and dietary risk factors, the researchers found that a daily 100-gram serving of unprocessed red meat (about the size of a deck of cards) was associated with a 19% increased risk of type 2 diabetes. They also found that one daily serving of half that quantity of processed meat -- 50 grams (for example, one hot dog or sausage or two slices of bacon) -- was associated with a 51% increased risk.
"Clearly, the results from this study have huge public health implications given the rising type 2 diabetes epidemic and increasing consumption of red meats worldwide," said Hu. "The good news is that such troubling risk factors can be offset by swapping red meat for a healthier protein."
The researchers found that, for an individual who eats one daily serving of red meat, substituting one serving of nuts per day was associated with a 21% lower risk of type 2 diabetes; substituting low-fat dairy, a 17% lower risk; and substituting whole grains, a 23% lower risk.
Based on these results, the researchers advise that consumption of processed red meat -- like hot dogs, bacon, sausage, and deli meats, which generally have high levels of sodium and nitrites -- should be minimized and unprocessed red meat should be reduced. If possible, they add, red meat should be replaced with healthier choices, such as nuts, whole grains, low-fat dairy products, fish, or beans.
Worldwide, diabetes has reached epidemic levels, affecting nearly 350 million adults. In the U.S. alone, more than 11% of adults over age 20 -- 25.6 million people -- have the disease, according to the Centers for Disease Control and Prevention. Most have type 2 diabetes, which is primarily linked to obesity, physical inactivity, and an unhealthy diet.
Previous studies have indicated that eating processed red meats increases the risk of developing type 2 diabetes. Risks from unprocessed meats have been less clear. For instance, in 2010, HSPH researchers found no clear evidence of an association between eating unprocessed meats and increased risk for either coronary heart disease or type 2 diabetes, but that study was based on smaller samples than the current study, and the researchers recommended further study of unprocessed meats. Another HSPH study in 2010 linked eating red meat with an increased risk of heart disease -- which is strongly linked to diabetes -- but did not distinguish between processed and unprocessed red meats.
This new study -- the largest of its kind in terms of sample size and follow-up years -- finds that both unprocessed and processed meats pose a type 2 diabetes risk, thus helping to clarify the issue. In addition, this study is among the first to estimate the risk reduction associated with substituting healthier protein choices for red meat.
"Our study clearly shows that eating both unprocessed and processed red meat -- particularly processed -- is associated with an increased risk of type 2 diabetes," said Pan. He noted that the 2010 U.S. dietary guidelines continue to lump red meat together with fish, poultry, eggs, nuts, seeds, beans, and soy products in the "protein foods" group. But since red meat appears to have significant negative health effects -- increased risk of diabetes, cardiovascular disease, and even total mortality, as suggested by several recent studies -- Pan suggested the guidelines should distinguish red meat from healthier protein sources and promote the latter instead.
Support for the study was provided by the National Institutes of Health's National Institute of Diabetes and Digestive and Kidney Diseases and the National Heart, Lung, and Blood Institute.
**Source: Harvard School of Public Health
Científicos españoles participan en el mayor estudio genético de la esclerosis múltiple
Un consorcio internacional de investigación, en el que han participado dos centros españoles, ha llevado a cabo el mayor estudio genómico sobre la esclerosis múltiple. Los científicos han hallado 29 nuevas variantes genéticas vinculadas a esta patología neurodegenerativa, han ratificado la presencia de otras 23 descritas previamente y han encontrado cinco más altamente sospechosas de desempeñar un papel relevante. La mayoría de los marcadores identificados están relacionados con el funcionamiento del sistema de defensa del organismo.
"Ahora está claro que la enfermedad es principalmente inmunológica y esto tiene implicaciones importantes para futuras estrategias terapéuticas", señala Alastair Compston, investigador de la Universidad de Cambridge (Reino Unido) que encabeza el trabajo que publica la última edición de 'Nature' .
La esclerosis múltiple es consecuencia del daño que se produce sobre las fibras nerviosas y su capa protectora (la vaina de mielina) en el cerebro y la médula espinal. Esto se traduce en una afectación de las estructuras neuronales responsables de acciones como ver, caminar o controlar la vejiga. El nuevo estudio ayudará a explicar el ataque devastador del sistema inmune sobre el cerebro y la médula espinal.
Pablo Villoslada, del Centro de Neuroinmunología del Hospital Clínic de Barcelona y firmante del estudio, considera que se ha logrado encontrar "la huella dactilar de la esclerosis múltiple en el genoma humano". Cada uno de los marcadores identificados contribuye muy poco al desarrollo de la enfermedad, pero en conjunto pueden tener un cometido crucial en el riesgo de padecerla.
En cuanto al hecho de que las variantes genéticas halladas estén relacionadas casi exclusivamente con el sistema inmune, Villoslada señala que no ha sido ninguna sorpresa. No obstante, puntualiza que hasta ahora no estaba muy claro si el sistema inmune era "la causa o la consecuencia". Todo parece apuntar a la primera posibilidad. Manuel Comabella, del Instituto de Investigación del Hospital Vall d'Hebron de Barcelona y también coautor de la investigación, recalca que "no se ha encontrado ningún gen vinculado al cerebro o la médula espinal", que son los órganos diana de la enfermedad.
El trabajo no sólo ha ratificado la implicación del sistema de defensa del organismo, sino también los mecanismos concretos que llevan a los daños que sufren los pacientes. Los principales culpables son los linfocitos T, que son un tipo de células de la sangre cuyo papel es organizar la respuesta inmunológica contra las sustancias extrañas, pero que cuando no 'funcionan' adecuadamente pueden atacar al propio organismo, desencadenando un proceso de autoinmunidad.
Los defectos genéticos que presenta el ADN de los afectados por esclerosis múltiple favorecen la migración de los linfocitos T hacia el cerebro, donde atacan a las vainas de mielina que protegen a las fibras nerviosas. En condiciones normales, este 'viaje' no es posible porque la denominada barrera hematoencefálica hace prácticamente infranqueable la entrada de cualquier elemento extraño al cerebro.
Una tercera parte de los genes identificados en esta investigación se habían descrito previamente en relación con otras dolencias autoinmunes, como la enfermedad de Crohn o la diabetes tipo 1. Esto indica que dichas patologías podrían compartir los mismos procesos biológicos.
El nuevo trabajo proporciona claves importantes para conocer mejor la enfermedad y desarrollar tratamientos cada vez más eficaces. No obstante, los investigadores advierten de que sólo se trata de una pieza más del puzle. Al fin y al cabo, es una patología compleja en la que el componente genético -determinado por múltiples genes- no es el único elemento importante. También son fundamentales los factores ambientales, entre los que descollan el déficit de vitamina D y las infecciones víricas, y especialmente las producidas por el virus de Epstein-Barr.
Según Villoslada, "este trabajo supone una aplicación directa del Proyecto Genoma Humano al estudio de las enfermedades". Se ha basado en el uso de las nuevas tecnologías para buscar las bases genéticas de la esclerosis múltiple. Los investigadores han analizado el ADN de más de 9.700 pacientes y 17.300 personas sanas. "Gracias a los métodos de secuenciación masiva hemos podido ver el genoma con mucho detalle", recalca el investigador. Este despliegue de medios garantiza "que las asociaciones genéticas encontradas son definitivas".
**Publicado en "EL MUNDO"
"Ahora está claro que la enfermedad es principalmente inmunológica y esto tiene implicaciones importantes para futuras estrategias terapéuticas", señala Alastair Compston, investigador de la Universidad de Cambridge (Reino Unido) que encabeza el trabajo que publica la última edición de 'Nature' .
La esclerosis múltiple es consecuencia del daño que se produce sobre las fibras nerviosas y su capa protectora (la vaina de mielina) en el cerebro y la médula espinal. Esto se traduce en una afectación de las estructuras neuronales responsables de acciones como ver, caminar o controlar la vejiga. El nuevo estudio ayudará a explicar el ataque devastador del sistema inmune sobre el cerebro y la médula espinal.
Pablo Villoslada, del Centro de Neuroinmunología del Hospital Clínic de Barcelona y firmante del estudio, considera que se ha logrado encontrar "la huella dactilar de la esclerosis múltiple en el genoma humano". Cada uno de los marcadores identificados contribuye muy poco al desarrollo de la enfermedad, pero en conjunto pueden tener un cometido crucial en el riesgo de padecerla.
En cuanto al hecho de que las variantes genéticas halladas estén relacionadas casi exclusivamente con el sistema inmune, Villoslada señala que no ha sido ninguna sorpresa. No obstante, puntualiza que hasta ahora no estaba muy claro si el sistema inmune era "la causa o la consecuencia". Todo parece apuntar a la primera posibilidad. Manuel Comabella, del Instituto de Investigación del Hospital Vall d'Hebron de Barcelona y también coautor de la investigación, recalca que "no se ha encontrado ningún gen vinculado al cerebro o la médula espinal", que son los órganos diana de la enfermedad.
El trabajo no sólo ha ratificado la implicación del sistema de defensa del organismo, sino también los mecanismos concretos que llevan a los daños que sufren los pacientes. Los principales culpables son los linfocitos T, que son un tipo de células de la sangre cuyo papel es organizar la respuesta inmunológica contra las sustancias extrañas, pero que cuando no 'funcionan' adecuadamente pueden atacar al propio organismo, desencadenando un proceso de autoinmunidad.
Los defectos genéticos que presenta el ADN de los afectados por esclerosis múltiple favorecen la migración de los linfocitos T hacia el cerebro, donde atacan a las vainas de mielina que protegen a las fibras nerviosas. En condiciones normales, este 'viaje' no es posible porque la denominada barrera hematoencefálica hace prácticamente infranqueable la entrada de cualquier elemento extraño al cerebro.
Una tercera parte de los genes identificados en esta investigación se habían descrito previamente en relación con otras dolencias autoinmunes, como la enfermedad de Crohn o la diabetes tipo 1. Esto indica que dichas patologías podrían compartir los mismos procesos biológicos.
El nuevo trabajo proporciona claves importantes para conocer mejor la enfermedad y desarrollar tratamientos cada vez más eficaces. No obstante, los investigadores advierten de que sólo se trata de una pieza más del puzle. Al fin y al cabo, es una patología compleja en la que el componente genético -determinado por múltiples genes- no es el único elemento importante. También son fundamentales los factores ambientales, entre los que descollan el déficit de vitamina D y las infecciones víricas, y especialmente las producidas por el virus de Epstein-Barr.
Según Villoslada, "este trabajo supone una aplicación directa del Proyecto Genoma Humano al estudio de las enfermedades". Se ha basado en el uso de las nuevas tecnologías para buscar las bases genéticas de la esclerosis múltiple. Los investigadores han analizado el ADN de más de 9.700 pacientes y 17.300 personas sanas. "Gracias a los métodos de secuenciación masiva hemos podido ver el genoma con mucho detalle", recalca el investigador. Este despliegue de medios garantiza "que las asociaciones genéticas encontradas son definitivas".
**Publicado en "EL MUNDO"
MS research doubles number of genes associated with the disease, increasing the number to over 50
Dr. John Rioux, researcher at the Montreal Heart Institute, Associate Professor of Medicine at the Université de Montréal and original co-founder of the International Multiple Sclerosis Genetics Consortium is one of the scientists who have identified 29 new genetic variants linked to multiple sclerosis, providing key insights into the biology of a very debilitating neurological disease. Many of the genes implicated in the study are relevant to the immune system, shedding light onto the immunological pathways that underlie the development of multiple sclerosis. The research, involving an international team of investigators led by the Universities of Cambridge and Oxford, and funded by the Wellcome Trust, was published August 10 in the journal Nature. This is the largest MS genetics study ever undertaken and includes contributions from almost 250 researchers as members of the International Multiple Sclerosis Genetics Consortium and the Wellcome Trust Case Control Consortium.
Multiple sclerosis is one of the most common neurological conditions among young adults, affecting around 2.5 million individuals worldwide. The disease results from damage to nerve fibres and their protective insulation, the myelin sheath, in the brain and spinal cord. The affected pathways -- responsible in health for everyday activities such as seeing, walking, feeling, thinking and controlling the bowel and bladder -- are prevented from 'firing' properly and eventually are destroyed. The new findings focus attention on the pivotal role of the immune system in causing the damage and help to explain the nature of the immune attack on the brain and spinal cord.
In this multi-population study, researchers studied the DNA from 9,772 individuals with multiple sclerosis and 17,376 unrelated healthy controls. They were able to confirm 23 previously known genetic associations and identified a further 29 new genetic variants (and an additional five that are strongly suspected) conferring susceptibility to the disease.
A large number of the genes implicated by these findings play pivotal roles in the workings of the immune system, specifically in the function of T-cells (one type of white blood cell responsible for mounting an immune response against foreign substances in the body but also involved in autoimmunity) as well as the activation of 'interleukins' (chemicals that ensure interactions between different types of immune cell). Interestingly, one third of the genes identified in this research have previously been implicated in playing a role in other autoimmune diseases (such as Crohn's Disease and Type 1 diabetes) indicating that, perhaps as expected, the same general processes occur in more than one type of autoimmune disease.
Previous research has suggested a link between Vitamin D deficiency and an increased risk of multiple sclerosis. Along with the many genes which play a direct role in the immune system, the researchers identified two involved in the metabolism of Vitamin D, providing additional insight into a possible link between genetic and environmental risk factors.
Dr. Alastair Compston from the University of Cambridge who, on behalf of the International Multiple Sclerosis Genetics Consortium, who led the study jointly with Dr. Peter Donnelly from the Wellcome Trust Centre for Human Genetics, University of Oxford, said: "Identifying the basis for genetic susceptibility to any medical condition provides reliable insights into the disease mechanisms. Our research settles a longstanding debate on what happens first in the complex sequence of events that leads to disability in multiple sclerosis. It is now clear that multiple sclerosis is primarily an immunological disease. This has important implications for future treatment strategies."
Dr. Donnelly added: "Our findings highlight the value of large genetic studies in uncovering key biological mechanisms underlying common human diseases. This would simply not have been possible without a large international network of collaborators, and the participation of many thousands of patients suffering from this debilitating disease."
Dr. John Rioux, holder of the Canada Research Chair in Genetics and Genomic Medicine, furthermore stated that "the integration of the genetic information emerging from studies of this and other chronic inflammatory diseases such as Crohn's disease, ulcerative colitis, arthritis and many others is revealing what is shared across these diseases and what is disease-specific. This is but one of the key bits of information emerging from these studies that will guide the research of disease biology for years to come and be the basis for the development of a more personalized approach to medicine."
**Source: University of Montreal
Multiple sclerosis is one of the most common neurological conditions among young adults, affecting around 2.5 million individuals worldwide. The disease results from damage to nerve fibres and their protective insulation, the myelin sheath, in the brain and spinal cord. The affected pathways -- responsible in health for everyday activities such as seeing, walking, feeling, thinking and controlling the bowel and bladder -- are prevented from 'firing' properly and eventually are destroyed. The new findings focus attention on the pivotal role of the immune system in causing the damage and help to explain the nature of the immune attack on the brain and spinal cord.
In this multi-population study, researchers studied the DNA from 9,772 individuals with multiple sclerosis and 17,376 unrelated healthy controls. They were able to confirm 23 previously known genetic associations and identified a further 29 new genetic variants (and an additional five that are strongly suspected) conferring susceptibility to the disease.
A large number of the genes implicated by these findings play pivotal roles in the workings of the immune system, specifically in the function of T-cells (one type of white blood cell responsible for mounting an immune response against foreign substances in the body but also involved in autoimmunity) as well as the activation of 'interleukins' (chemicals that ensure interactions between different types of immune cell). Interestingly, one third of the genes identified in this research have previously been implicated in playing a role in other autoimmune diseases (such as Crohn's Disease and Type 1 diabetes) indicating that, perhaps as expected, the same general processes occur in more than one type of autoimmune disease.
Previous research has suggested a link between Vitamin D deficiency and an increased risk of multiple sclerosis. Along with the many genes which play a direct role in the immune system, the researchers identified two involved in the metabolism of Vitamin D, providing additional insight into a possible link between genetic and environmental risk factors.
Dr. Alastair Compston from the University of Cambridge who, on behalf of the International Multiple Sclerosis Genetics Consortium, who led the study jointly with Dr. Peter Donnelly from the Wellcome Trust Centre for Human Genetics, University of Oxford, said: "Identifying the basis for genetic susceptibility to any medical condition provides reliable insights into the disease mechanisms. Our research settles a longstanding debate on what happens first in the complex sequence of events that leads to disability in multiple sclerosis. It is now clear that multiple sclerosis is primarily an immunological disease. This has important implications for future treatment strategies."
Dr. Donnelly added: "Our findings highlight the value of large genetic studies in uncovering key biological mechanisms underlying common human diseases. This would simply not have been possible without a large international network of collaborators, and the participation of many thousands of patients suffering from this debilitating disease."
Dr. John Rioux, holder of the Canada Research Chair in Genetics and Genomic Medicine, furthermore stated that "the integration of the genetic information emerging from studies of this and other chronic inflammatory diseases such as Crohn's disease, ulcerative colitis, arthritis and many others is revealing what is shared across these diseases and what is disease-specific. This is but one of the key bits of information emerging from these studies that will guide the research of disease biology for years to come and be the basis for the development of a more personalized approach to medicine."
**Source: University of Montreal
40 millones de niños menores de cinco años sufren sobrepeso u obesidad en todo el mundo
Alrededor de 40 millones de niños menores de cinco años de todo el mundo sufren sobrepeso u obesidad, mientras que la desnutrición mata cada año a otros cuatro millones de pequeños. Así lo advirtió este miércoles la Organización Mundial de la Salud (OMS), que ha lanzado una web para proporcionar información a los gobiernos y a los trabajadores de la salud sobre las distintas formas de malnutrición.
Con ella, la OMS tratará de ayudar a combatir la desnutrición, la deficiencia de vitaminas y minerales, el sobrepeso y la obesidad. Según datos de esta agencia de la ONU, casi cuatro millones de niños mueren cada año por desnutrición. Al mismo tiempo, 40 millones de menores de cinco años sufren de sobrepeso u obesidad.
Entre otras cuestiones, la web proporciona claves en el tratamiento de la desnutrición aguda (frente a emergencias como las que sufre actualmente el Cuerno de África), y subraya la importancia de la lactancia materna durante los primeros seis meses de vida de un bebé.
Entre otras cuestiones, ofrece información sobre las raciones recomendadas de micronutrientes, vitaminas y minerales en polvo en la dieta de los niños de entre seis y 23 meses, y sobre los suplementos recomendados para las mujeres embarazadas.
Con ella, la OMS tratará de ayudar a combatir la desnutrición, la deficiencia de vitaminas y minerales, el sobrepeso y la obesidad. Según datos de esta agencia de la ONU, casi cuatro millones de niños mueren cada año por desnutrición. Al mismo tiempo, 40 millones de menores de cinco años sufren de sobrepeso u obesidad.
Entre otras cuestiones, la web proporciona claves en el tratamiento de la desnutrición aguda (frente a emergencias como las que sufre actualmente el Cuerno de África), y subraya la importancia de la lactancia materna durante los primeros seis meses de vida de un bebé.
Entre otras cuestiones, ofrece información sobre las raciones recomendadas de micronutrientes, vitaminas y minerales en polvo en la dieta de los niños de entre seis y 23 meses, y sobre los suplementos recomendados para las mujeres embarazadas.
**Publicado por "SERVIMEDIA"
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