American scientists believe a new procedure to repair severed nerves could result in patients recovering in days or weeks, rather than months or years. The team used a cellular mechanism similar to that used by many invertebrates to repair damage to nerve axons. Their results were recently published in the Journal of Neuroscience Research.
"We have developed a procedure which can repair severed nerves within minutes so that the behavior they control can be partially restored within days and often largely restored within two to four weeks," said Professor George Bittner from the University of Texas. "If further developed in clinical trials this approach would be a great advance on current procedures that usually imperfectly restore lost function within months at best."
The team studied the mechanisms all animal cells use to repair damage to their membranes and focused on invertebrates, which have a superior ability to regenerate nerve axons compared to mammals. An axon is a long extension arising from a nerve cell body that communicates with other nerve cells or with muscles.
This research success arises from Bittner's discovery that nerve axons of invertebrates which have been severed from their cell body do not degenerate within days, as happens with mammals, but can survive for months, or even years.
The severed proximal nerve axon in invertebrates can also reconnect with its surviving distal nerve axon to produce much quicker and much better restoration of behaviour than occurs in mammals.
"Severed invertebrate nerve axons can reconnect proximal and distal ends of severed nerve axons within seven days, allowing a rate of behavioural recovery that is far superior to mammals," said Bittner. "In mammals the severed distal axonal stump degenerates within three days and it can take nerve growths from proximal axonal stumps months or years to regenerate and restore use of muscles or sensory areas, often with less accuracy and with much less function being restored."
The team described their success in applying this process to rats in two new research papers. The team were able to repair severed sciatic nerves in the upper thigh, with results showing the rats were able to use their limb within a week and had much function restored within 2 to 4 weeks, in some cases to almost full function.
"We used rats as an experimental model to demonstrate how severed nerve axons can be repaired. Without our procedure, the return of nearly full function rarely comes close to happening," said Bittner. "The sciatic nerve controls all muscle movement of the leg of all mammals and this new approach to repairing nerve axons could almost-certainly be just as successful in humans."
To explore the long term implications and medical uses of this procedure, MD's and other scientist- collaborators at Harvard Medical School and Vanderbilt Medical School and Hospitals are conducting studies to obtain approval to begin clinical trials.
"We believe this procedure could produce a transformational change in the way nerve injuries are repaired," concluded Bittner.
*Source: Wiley-Blackwell
05 February 2012
¿Qué es la Inseminación Artificial?
La Inseminación Artificial( IA) es una de las técnicas que existen actualmente en Reproducción Humana Asistida. Es el procedimiento más sencillo y consiste en depositar de forma artificial espermatozoides previamente seleccionados en el tracto reproductor femenino. De esta manera, se intenta acortar la distancia que separa óvulo y espermatozoide y facilitar el encuentro entre ambos.
Se habla de inseminación artificial conyugal( IAC) cuando se realiza con espermatozoides de la pareja y de Inseminación artificial donante( IAD) cuando el semen es de donante.
La IA consta de tres fases: estimulación hormonal del ovario para aumentar el número de ovocitos maduros, preparación del semen( seleccionando y concentrando los espermatozoides móviles) y, finalmente, la inseminación de la mujer.
Se habla de inseminación artificial conyugal( IAC) cuando se realiza con espermatozoides de la pareja y de Inseminación artificial donante( IAD) cuando el semen es de donante.
La IA consta de tres fases: estimulación hormonal del ovario para aumentar el número de ovocitos maduros, preparación del semen( seleccionando y concentrando los espermatozoides móviles) y, finalmente, la inseminación de la mujer.
Coughing and other respiratory symptoms improve within weeks of smoking cessation
If the proven long-term benefits of smoking cessation are not enough to motivate young adults to stop smoking, a new study shows that 18- to 24-year olds who stop smoking for at least two weeks report substantially fewer respiratory symptoms, especially coughing. The study findings are detailed in Pediatric Allergy, Immunology, and Pulmonology, a peer-reviewed journal published by Mary Ann Liebert, Inc. Karen Calabro, DrPH and Alexander Prokhorov, MD, PhD, The University of Texas MD Anderson Cancer Center, Houston, compared self-reported respiratory symptoms among two groups of college students who participated in programs designed to motivate them to stop smoking. One group achieved smoking cessation for two weeks or longer and the other group failed to stop smoking. More than half of the students smoked 5-10 cigarettes a day and had smoked for 1-5 years.
"That the benefit of stopping smoking starts in days to weeks-not years or decades-is important. Now health care providers can counsel young smokers that their breathing can feel better soon after they stop. This can help to motivate young adults to stop smoking before the severe damage is done," says Harold Farber, MD, MSPH, Editor of Pediatric Allergy, Immunology, and Pulmonology and Associate Professor of Pediatrics, Section of Pulmonology, Baylor College of Medicine, Houston, TX.
"That the benefit of stopping smoking starts in days to weeks-not years or decades-is important. Now health care providers can counsel young smokers that their breathing can feel better soon after they stop. This can help to motivate young adults to stop smoking before the severe damage is done," says Harold Farber, MD, MSPH, Editor of Pediatric Allergy, Immunology, and Pulmonology and Associate Professor of Pediatrics, Section of Pulmonology, Baylor College of Medicine, Houston, TX.
*Source: Mary Ann Liebert, Inc., Publishers
Gene related to fat preferences in humans found
A preference for fatty foods has a genetic basis, according to researchers, who discovered that people with certain forms of the CD36 gene may like high-fat foods more than those who have other forms of this gene. The results help explain why some people struggle when placed on a low-fat diet and may one day assist people in selecting diets that are easier for them to follow. The results also may help food developers create new low-fat foods that taste better.
"Fat is universally palatable to humans," said Kathleen Keller, assistant professor of nutritional sciences, Penn State. "Yet we have demonstrated for the first time that people who have particular forms of the CD36 gene tend to like higher fat foods more and may be at greater risk for obesity compared to those who do not have this form of the gene. In animals, CD36 is a necessary gene for the ability to both detect and develop preferences for fat. Our study is one of the first to show this relationship in humans."
Keller and a team of scientists from Penn State, Columbia University, Cornell University and Rutgers University examined 317 African-American males and females because individuals in this ethnic group are highly vulnerable to obesity and thus are at greatest risk for obesity-related diseases.
The team gave the participants Italian salad dressings prepared with varying amounts of canola oil, which is rich in long-chain fatty acids. The participants were then asked to rate their perceptions of the dressings' oiliness, fat content and creaminess on a scale anchored on the ends with "extremely low" and "extremely high."
The team also gave participants questionnaires aimed at understanding their food preferences. Participants rated how much they liked each food on a scale anchored with "dislike extremely" and "like extremely." Foods included on the questionnaire were associated with poor dietary intake and health outcomes, such as half-and-half, sour cream, mayonnaise, bacon, fried chicken, hot dogs, French fries, cheese, chips, cake, cookies and doughnuts.
The researchers collected saliva samples from the participants to determine which forms of CD36 they had. From the saliva samples, they extracted DNA fragments and examined differences in the CD36 gene contained within the fragments.
They found that participants who had the "AA" form of the gene -- present in 21 percent of the population -- rated the salad dressings as creamier than individuals who had other forms of the gene. These individuals reported that the salad dressings were creamier regardless of how much fat was actually in them. The researchers also found that "AA" individuals liked salad dressings, half-and-half, olive oil and other cooking oils more than those who had other forms of the gene. The results are published in a recent issue of the journal Obesity.
"It is possible that the CD36 gene is associated with fat intake and therefore obesity through a mechanism of oral fat perception and preference," said Keller. "In other words, our results suggest that people with certain forms of the CD36 gene may find fat creamier and more enjoyable than others. This may increase their risk for obesity and other health problems."
According to Keller, having certain forms of a gene that help in the perception and enjoyment of fats in foods might once have been an advantage.
"Fats are essential in our diets," she said. "In our evolutionary history, people who were better able to recognize fats in foods were more likely to survive. Such forms of the gene, however, are less useful to us today as most of us no longer have to worry about getting enough fats in our diets."
In fact, she added, having such forms of a gene can be detrimental in today's world of fat-laden convenience foods.
"Our results may help explain why some people have more difficulty adhering to a low-fat diet than other people and why these same people often do better when they adopt high-fat, low-carbohydrate diets such as the Atkins diet," said Keller. "We hope these results will one day help people select diets that are easier for them to follow. We also think the results could help food developers create better tasting low-fat foods that appeal to a broader range of the population."
In the future, the team plans to expand the population they examine to include children.
"By the time we are adults it is very hard for us to change our eating behaviors," said Keller. "So if we can determine which children have forms of the CD36 gene, as well as other genes that are associated with greater liking of fats, we can help them develop healthier eating behaviors at a young age."
Keller also plans to incorporate novel techniques, such as functional magnetic resonance imaging (fMRI), to better understand why certain forms of the CD36 gene are linked to higher fat preferences.
"We plan to scan children while they are tasting high-fat foods and beverages so that we can see how their brains react to fats," she said. "By doing this, we may be able to develop foods that are perceived by the brain as palatable high-fat treats, even though in reality, they are low-fat and healthy."
**Source: Penn State
"Fat is universally palatable to humans," said Kathleen Keller, assistant professor of nutritional sciences, Penn State. "Yet we have demonstrated for the first time that people who have particular forms of the CD36 gene tend to like higher fat foods more and may be at greater risk for obesity compared to those who do not have this form of the gene. In animals, CD36 is a necessary gene for the ability to both detect and develop preferences for fat. Our study is one of the first to show this relationship in humans."
Keller and a team of scientists from Penn State, Columbia University, Cornell University and Rutgers University examined 317 African-American males and females because individuals in this ethnic group are highly vulnerable to obesity and thus are at greatest risk for obesity-related diseases.
The team gave the participants Italian salad dressings prepared with varying amounts of canola oil, which is rich in long-chain fatty acids. The participants were then asked to rate their perceptions of the dressings' oiliness, fat content and creaminess on a scale anchored on the ends with "extremely low" and "extremely high."
The team also gave participants questionnaires aimed at understanding their food preferences. Participants rated how much they liked each food on a scale anchored with "dislike extremely" and "like extremely." Foods included on the questionnaire were associated with poor dietary intake and health outcomes, such as half-and-half, sour cream, mayonnaise, bacon, fried chicken, hot dogs, French fries, cheese, chips, cake, cookies and doughnuts.
The researchers collected saliva samples from the participants to determine which forms of CD36 they had. From the saliva samples, they extracted DNA fragments and examined differences in the CD36 gene contained within the fragments.
They found that participants who had the "AA" form of the gene -- present in 21 percent of the population -- rated the salad dressings as creamier than individuals who had other forms of the gene. These individuals reported that the salad dressings were creamier regardless of how much fat was actually in them. The researchers also found that "AA" individuals liked salad dressings, half-and-half, olive oil and other cooking oils more than those who had other forms of the gene. The results are published in a recent issue of the journal Obesity.
"It is possible that the CD36 gene is associated with fat intake and therefore obesity through a mechanism of oral fat perception and preference," said Keller. "In other words, our results suggest that people with certain forms of the CD36 gene may find fat creamier and more enjoyable than others. This may increase their risk for obesity and other health problems."
According to Keller, having certain forms of a gene that help in the perception and enjoyment of fats in foods might once have been an advantage.
"Fats are essential in our diets," she said. "In our evolutionary history, people who were better able to recognize fats in foods were more likely to survive. Such forms of the gene, however, are less useful to us today as most of us no longer have to worry about getting enough fats in our diets."
In fact, she added, having such forms of a gene can be detrimental in today's world of fat-laden convenience foods.
"Our results may help explain why some people have more difficulty adhering to a low-fat diet than other people and why these same people often do better when they adopt high-fat, low-carbohydrate diets such as the Atkins diet," said Keller. "We hope these results will one day help people select diets that are easier for them to follow. We also think the results could help food developers create better tasting low-fat foods that appeal to a broader range of the population."
In the future, the team plans to expand the population they examine to include children.
"By the time we are adults it is very hard for us to change our eating behaviors," said Keller. "So if we can determine which children have forms of the CD36 gene, as well as other genes that are associated with greater liking of fats, we can help them develop healthier eating behaviors at a young age."
Keller also plans to incorporate novel techniques, such as functional magnetic resonance imaging (fMRI), to better understand why certain forms of the CD36 gene are linked to higher fat preferences.
"We plan to scan children while they are tasting high-fat foods and beverages so that we can see how their brains react to fats," she said. "By doing this, we may be able to develop foods that are perceived by the brain as palatable high-fat treats, even though in reality, they are low-fat and healthy."
**Source: Penn State
Se celebró en Málaga la Reunión Nacional de Consultas de Esterilidad
Unos 150 especialistas en Ginecología de toda España han participado en Málaga en la Reunión Nacional de Consultas de Esterilidad, organizada por Merck Serono con el apoyo del Hospital Quirón de Málaga. El tema principal fde debate fue la situación actual de la Inseminación Artificial en España, considerada una de las técnicas más exitosas para un perfil determinado de parejas que tienen problemas para ser padres.
En Málaga cada año se producen unas 2.500 por esterilidad, cifra que a la hora de la verdad es mayor "por razones de miedo o vergüenza a la hora de exponer su problema", según afirmó el doctor Enrique Pérez de la Blanca( de la Unidad de Reproducción Asistida del Hospital Quirón de Málaga. En la provincia hay 18 Centros de Reproducción Humana Asistida acreeditados, que realizan unas 2.000 inseminaciones artificialesd por año. En 2010 nacieron 250 bebés en ña provincia gracias a esta técnica.
Para la doctora Olga Ramón( de la Unidad de Reproducción Humana del Hospital Cruces de Bilbao) "esta técnica es menos costosa y, en un elevado porcentaje, se trata a las pacientes utilizando medicamentos con una innovadora biotecnología recombinante, como ocurre en la FIV. Mujeres con una adecuada reserva ovárica y al menos una trompa permeable, cuyo compañero cuente con una recuperación de espermatozoidez móviles igual o superior a 5.000.000, son perfectas candidatas para logar el embarazo mediante inseminación artificial".
Los problemas de fertilidad afectan en España a una de cada seis parejas. El retraso en la maternidad aparece como uno de los principales factores que influyen en esto. El doctor Eleuterio Hernández( del Centro de Reproducción FIV-Madrid) indicó "que en el Registro de la SEF( Sociedad Española de Fertilidad) se observa que el 40% de los tratamientos de Reproducción Asistidad en España son inseminaciones artificiales conyugales. La tasa de embarazo por paciente tras 4 o 6 ciclos consecutivos puede llegar casi al 50%".
En Málaga cada año se producen unas 2.500 por esterilidad, cifra que a la hora de la verdad es mayor "por razones de miedo o vergüenza a la hora de exponer su problema", según afirmó el doctor Enrique Pérez de la Blanca( de la Unidad de Reproducción Asistida del Hospital Quirón de Málaga. En la provincia hay 18 Centros de Reproducción Humana Asistida acreeditados, que realizan unas 2.000 inseminaciones artificialesd por año. En 2010 nacieron 250 bebés en ña provincia gracias a esta técnica.
Para la doctora Olga Ramón( de la Unidad de Reproducción Humana del Hospital Cruces de Bilbao) "esta técnica es menos costosa y, en un elevado porcentaje, se trata a las pacientes utilizando medicamentos con una innovadora biotecnología recombinante, como ocurre en la FIV. Mujeres con una adecuada reserva ovárica y al menos una trompa permeable, cuyo compañero cuente con una recuperación de espermatozoidez móviles igual o superior a 5.000.000, son perfectas candidatas para logar el embarazo mediante inseminación artificial".
Los problemas de fertilidad afectan en España a una de cada seis parejas. El retraso en la maternidad aparece como uno de los principales factores que influyen en esto. El doctor Eleuterio Hernández( del Centro de Reproducción FIV-Madrid) indicó "que en el Registro de la SEF( Sociedad Española de Fertilidad) se observa que el 40% de los tratamientos de Reproducción Asistidad en España son inseminaciones artificiales conyugales. La tasa de embarazo por paciente tras 4 o 6 ciclos consecutivos puede llegar casi al 50%".
Primer multicanal de contenido educativo en Youtube
GuíaInfantil.com, la revista digital líder en contenidos de educación y salud infantil ha creado en youtube un red de canales de recursos educativos. Ahora los niños van a poder disfrutar de un profesor en la web, ya que junto a sus padres o profesores tendrán a su disposición un amplio abanico de contenidos.
El objetivo de esta nueva red es ofrecer guías infantiles online con una amplia variedad de contenidos educativos dirigidos a España y el mundo hisponohablante, y entre los que se encuentran vídeos sobre educación (idiomas, deportes, educación artística...), entretenimiento (cuentos para niños, recetas), salud (embarazo, pediatría, psicología, salud dental y visual), etc.
GuíaInfantil Network está abierta a todos los canales de empresas, instituciones y profesionales que produzcan contenido original de educación infantil y entretenimiento familiar y temáticas afines como embarazo, bebés, salud, educación y ocio infantil.
Para más información: guiainfantil.net
El objetivo de esta nueva red es ofrecer guías infantiles online con una amplia variedad de contenidos educativos dirigidos a España y el mundo hisponohablante, y entre los que se encuentran vídeos sobre educación (idiomas, deportes, educación artística...), entretenimiento (cuentos para niños, recetas), salud (embarazo, pediatría, psicología, salud dental y visual), etc.
GuíaInfantil Network está abierta a todos los canales de empresas, instituciones y profesionales que produzcan contenido original de educación infantil y entretenimiento familiar y temáticas afines como embarazo, bebés, salud, educación y ocio infantil.
Para más información: guiainfantil.net
Bikram yoga: entrenar cuerpo y mente a 40 grados
La sensación es agradable al cruzar la puerta. Arropada por 36 grados de temperatura, recorre con los pies desnudos la sala. La respiración es la única que habla (lo llaman «pranayama»). Y cada vez es más profunda, más intensa... Los grados suben, 37... 39... 40ºC. Los músculos se van relajando a medida que se realizan las diferentes posturas. El 45 por ciento de humedad que envuelve la habitación amansa la tensión, dando paso a la energía, que comienza su desfile por el cuerpo al tiempo que las gotas de sudor descienden por la frente, por el cuello, por la espalda, por el pecho...
-Concéntrate y respira.
Noventa minutos en los que la agresividad de la vida diaria pierde fuelle.Es el yoga caliente, o Bikram yoga, un entrenamiento que mejora no sólo la fuerza física sino también la flexibilidad y el equilibrio, al tiempo que aumenta la claridad mental y la concentración. Paloma Jiménez, maestra de esta disciplina en el Bikram Yoga College of India Madrid explica que «la base de 84 posturas (asanas) originarias para trabajar todo el cuerpo se redujo a 26 más dos ejercicios del ya mencionado pranayama. Todas se realizan dos veces». Y cada una de ellas se centra en los distintos sistemas del cuerpo, (aparato digestivo, circulatorio, respiratorio, óseo, nervioso...). Con voz serena, Paloma dirige: «Manos hacia el suelo, detrás de los talones, pecho a las rodillas, respiramos... Relajamos los brazos y la cabeza». Y ahora, una de equilibrio. Subimos la pierna y con los dedos entrelazados cogemos el talón... Cada uno hasta donde pueda. Y al practicarlo con calor, hay menos riesgo de lesiones y se trabaja con mayor profundidad y seguridad. Aumenta la circulación de la sangre, incrementa la energía, y se eliminan toxinas».
Es bueno también contra el insomnio y el estreñimiento. Los primeros 60 minutos, tras calentar la columna, se realizan posturas de pie trabajando el equilibrio, «y cada una de ellas prepara para la siguiente», aclara Jiménez. Los 30 minutos restantes «se practican en el suelo con un trabajo de espalda que finaliza con media torsión de la columna y una respiración final: Kapalabhati», una técnica que facilita la limpieza de las vías respiratorias y calma la mente. Y hay quienes aseguran, además, que ayuda incluso a perder peso.
Pero no todos están dispuestos a soportar tanto calor y desconfían de los beneficios que el ejercicio a 40ºC pueda reportar. Y en algunos casos, no resulta recomendable. Por ejemplo, para personas que sufren lesiones obstructivas vasculares y no están controladas. «Pese a que el yoga es un ejercicio estático, no dinámico, exige un esfuerzo y supone una sobrecarga cardiovascular, aumenta la frecuencia cardiaca y la tensión arterial», por lo que no está aconsejado en hipertensos, explica Araceli Boraita, cardióloga del Consejo Superior de Deportes y vocal de las sociedades filiales de la Sociedad Española de Cardiología. Si, además, la persona «toma medicamentos vasodilatadores, el efecto del calor se suma y puede generar hipotensión».
Y los expertos señalan que aquellas personas que tienen varices deben tener cuidado, pues «el retorno venoso con esa temperatura se vuelve más dificultoso». Y hay que estar bien hidratado, dicen «porque el sudor durante 90 minutos puede producir deshidratación si no se vigila».
Manuel Rabadán, jefe del Departamento de Fisiología del Consejo Superior de Deportes matiza que «generalmente, en verano prescribimos el ejercicio bien a primera hora de la mañana o a última de la tarde para evitar precisamente las horas más calurosas». Ambos especialistas señalan que, si bien «las personas sanas pueden practicarlo, siempre que uno no se encuentre totalmente bien, deben consultar antes a su especialista, y más si se está tomando medicación».
-Los profesores tienen esto muy en cuenta.
De hecho, la profesora del Bikran College of India de Madrid aclara que en líneas generales, «incluso quienes no han practicado nunca deporte pueden hacerlo a su nivel. Pero es cierto que quienes tengan la tensión alta y tomen medicación o bien aquellos que hayan sido operados deben hablar antes con su médico». Así lo hizo Bárbara, que tiene nada menos que 72 años y «aunque tengo problemas vertebrales vengo todas las semanas desde el pasado mes de agosto y me viene genial. Hago hasta donde puedo y me noto mucho mejor, sobre todo en las piernas». A Bárbara la apuntó su propio hijo al ver lo terapéutico de esta práctica. Y Alejandra comenzó recomendada por sus suegros. «Ellos lo practicaban y vine por la recuperación de mi primer embarazo. Luego cogí el hábito y la verdad es que engancha. Siento un gran equilibrio físico, más energía y más tranquilidad».
-Crecimiento personal
Y se debe al beneficio psicológico de este tipo de disciplina. Según explica la psicóloga Almudena Sánchez Mazarro, «enseña a contactar con los propios límites y a aceptarlos desde la humildad». Así, poco a poco, «con esta actitud de respeto y autoaceptación de las limitaciones, se avanza en la práctica». Sánchez Mazarro señala que el yoga «ayuda a desarrollar la tolerancia a la frustración y a centrarse en uno mismo, modificar las posturas y adaptarlas a las necesidades de cada uno (no estar preocupado por cómo la hace el compañero). El yoga concede más importancia «a la calidad del movimiento que a su cantidad, y a la conciencia del proceso más que a la meta».
**Publicado en "LA RAZON"
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