Bedwetting isn't always due to problems with the bladder, according to new research by Wake Forest Baptist Medical Center. Constipation is often the culprit; and if it isn't diagnosed, children and their parents must endure an unnecessarily long, costly and difficult quest to cure nighttime wetting. Reporting online in the journal Urology, researchers found that 30 children and adolescents who sought treatment for bedwetting all had large amounts of stool in their rectums, despite the majority having normal bowel habits. After treatment with laxative therapy, 25 of the children (83 percent) were cured of bedwetting within three months.
"Having too much stool in the rectum reduces bladder capacity," said lead author Steve J. Hodges, M.D., assistant professor of urology at Wake Forest Baptist. "Our study showed that a large percentage of these children were cured of nighttime wetting after laxative therapy. Parents try all sorts of things to treat bedwetting -- from alarms to restricting liquids. In many children, the reason they don't work is that constipation is the problem."
Hodges said the link between bedwetting and excess stool in the rectum, which is the lower five to six inches of the intestine, was first reported in 1986. However, he said the finding did not lead to a dramatic change in clinical practice, perhaps because the definition of constipation is not standardized or uniformly understood by all physicians and lay people.
"The definition for constipation is confusing and children and their parents often aren't aware the child is constipated," said Hodges. "In our study, X-rays revealed that all the children had excess stool in their rectums that could interfere with normal bladder function. However, only three of the children described bowel habits consistent with constipation."
Hodges explained that guidelines of the International Children's Continence Society recommend asking children and their parents if the child's bowel movements occur irregularly (less often than every other day) and if the stool consistency is hard.
"These questions focus on functional constipation and cannot help identify children with rectums that are enlarged and interfering with bladder capacity," said Hodges. "The kind of constipation associated with bedwetting occurs when children put off going to the bathroom. This causes stool to back up and their bowels to never be fully emptied. We believe that treating this condition can cure bedwetting."
Children in the study ranged from 5 to 15 years old. The constipated children were treated with an initial bowel cleanout using polyethylene glycol (Miralax®), which softens the stools by causing them to retain water. In children whose rectums remained enlarged after this therapy, enemas or stimulant laxatives were used.
Hodges cautioned that any medical therapy for bedwetting should be overseen by a physician.
The study used abdominal X-rays to identify the children with excess stool in their rectums. Hodges and radiologists at Wake Forest Baptist developed a special diagnostic method that involves measuring rectal size on the X-ray. He said rectal ultrasound could also be used for diagnosis.
"The importance of diagnosing this condition cannot be overstated," Hodges said. "When it is missed, children may be subjected to unnecessary surgery and the side effects of medications. We challenge physicians considering medications or surgery as a treatment for bedwetting to obtain an X-ray or ultrasound first."
The study involved reviewing the charts of 30 consecutive patients treated for bedwetting. The authors cautioned that some cases may have improved on their own over time. They said a more accurate measure of the treatment's success would be to randomly assign constipated children to laxative therapy or an inactive therapy, an approach that would identify true response from cases that would resolve over time.
*Source: Wake Forest Baptist Medical Center
31 January 2012
Un experimento con ratones muestra la pérdida de capacidad de luchar por la supervivencia cuando resulta afectada una región del hipocampo
Los científicos que hacen experimentos con ratones saben que si meten animales sanos en un recipiente de agua, como una piscina a escala, intentan nadar, mantener la cabeza a flote y salvar la vida. Sin embargo, en un ensayo con unos ratones transgénicos específicos, en cuyo cerebro se expresa en demasía una proteína denominada Tau, los investigadores han constatado que esos roedores se abandonan, no se esfuerzan por sobrevivir, no hacen nada cuando se están ahogando, han perdido todo interés. Comer sí que comen, pero sin especial afán por el alimento. Es un comportamiento depresivo que ha sorprendido a los científicos, un equipo de expertos en Alzheimer del Centro de Biología Molecular Severo Ochoa, del CSIC y la Universidad Autónoma de Madrid (UAM).
Las proteínas Tau, que en condiciones normales están implicadas en la constitución del armazón de las neuronas, se convierten en uno de los daños clásicos del cerebro de quienes padecen Alzheimer al formar ovillos que llenan las células de regiones concretas del cerebro hasta matarlas. El otro elemento clave de la enfermedad son las placas.
Jesús Ávila, María Victoria Llorens-Martín, Félix Hernández han hecho unos ratones transgénicos en cuyo cerebro (en el lóbulo temporal, donde está el hipocampo), se producen demasiadas proteínas Tau humanas. Esos roedores de laboratorio no llegan a tener problemas cognitivos hasta edades avanzadas (un año), pero mucho antes, con solo tres meses, tienen un comportamiento típicamente depresivo. Para los investigadores ha sido una sorpresa y están ahora estudiando la causa. De momento, dan a conocer los resultados del experimento en la revista Neuroscience y recuerdan que la depresión está, en algunos casos, asociada al Alzheimer.
Las proteínas Tau, que en condiciones normales están implicadas en la constitución del armazón de las neuronas, se convierten en uno de los daños clásicos del cerebro de quienes padecen Alzheimer al formar ovillos que llenan las células de regiones concretas del cerebro hasta matarlas. El otro elemento clave de la enfermedad son las placas.
Jesús Ávila, María Victoria Llorens-Martín, Félix Hernández han hecho unos ratones transgénicos en cuyo cerebro (en el lóbulo temporal, donde está el hipocampo), se producen demasiadas proteínas Tau humanas. Esos roedores de laboratorio no llegan a tener problemas cognitivos hasta edades avanzadas (un año), pero mucho antes, con solo tres meses, tienen un comportamiento típicamente depresivo. Para los investigadores ha sido una sorpresa y están ahora estudiando la causa. De momento, dan a conocer los resultados del experimento en la revista Neuroscience y recuerdan que la depresión está, en algunos casos, asociada al Alzheimer.
-Las proteínas Tau se convierten en uno de los daños clásicos del cerebro de quienes padecen Alzheimer
“La muerte de un tipo especial de células precursoras de las neuronas presentes en el cerebro, producida por la sobrexpresión de la proteína Tau, parece ocasionar en los ratones una pérdida de su capacidad de luchar por la supervivencia, lo cual es considerado un comportamiento semejante a la depresión humana”, explican los científicos. El hecho de que algunas regiones del cerebro sean especialmente sensibles a la expresión intensificada de esta proteína debe ser tenido en cuenta de cara a la prevención y tratamiento de las enfermedades neurodegenerativas, según un comunicado de la UAM.
¿Por qué se enfocan estas investigaciones en el hipocampo? “El cerebro posee una capacidad regeneradora necesaria para la prevención de ciertas enfermedades neurodegenerativas, capacidad que incluye el nacimiento de nuevas neuronas implicadas en los procesos de memoria y aprendizaje”, escriben los investigadores. Sin el nacimiento de nuevas neuronas el cerebro no sería capaz de almacenar nuevas memorias y esto parece estar relacionado con la aparición de procesos neurodegenerativos como el Alzheimer. Durante la vida adulta, el nacimiento de nuevas neuronas sólo se produce en algunas regiones del cerebro y en las personas, la más importante de estas regiones parece ser el hipocampo, relacionada con el aprendizaje y la memoria. Además, el hipocampo parece tener subregiones relacionadas también con el control de procesos emocionales.
“La muerte de un tipo especial de células precursoras de las neuronas presentes en el cerebro, producida por la sobrexpresión de la proteína Tau, parece ocasionar en los ratones una pérdida de su capacidad de luchar por la supervivencia, lo cual es considerado un comportamiento semejante a la depresión humana”, explican los científicos. El hecho de que algunas regiones del cerebro sean especialmente sensibles a la expresión intensificada de esta proteína debe ser tenido en cuenta de cara a la prevención y tratamiento de las enfermedades neurodegenerativas, según un comunicado de la UAM.
¿Por qué se enfocan estas investigaciones en el hipocampo? “El cerebro posee una capacidad regeneradora necesaria para la prevención de ciertas enfermedades neurodegenerativas, capacidad que incluye el nacimiento de nuevas neuronas implicadas en los procesos de memoria y aprendizaje”, escriben los investigadores. Sin el nacimiento de nuevas neuronas el cerebro no sería capaz de almacenar nuevas memorias y esto parece estar relacionado con la aparición de procesos neurodegenerativos como el Alzheimer. Durante la vida adulta, el nacimiento de nuevas neuronas sólo se produce en algunas regiones del cerebro y en las personas, la más importante de estas regiones parece ser el hipocampo, relacionada con el aprendizaje y la memoria. Además, el hipocampo parece tener subregiones relacionadas también con el control de procesos emocionales.
**Publicado en "EL PAIS"
Multiple births lead to weight gain and other problems for mouse moms and male offspring
Women have long bemoaned the fact that as they have more children, their weight gain from pregnancy becomes more difficult to lose. A new study using a mouse model that mimics the human effects of multiparity (giving birth more than once) has found that mouse moms who gave birth four times accrued significantly more fat compared to primiparous females (those giving birth once) of similar age. The study also found significantly more inflammation in the livers of multiparous animals. Multiparity's effect also extended to the male offspring, who showed significant weight gain during adulthood. Their primiparous counterparts did not, despite similar levels of food consumption. The findings are contained in a study entitled "Multiparity Leads to Obesity and Inflammation in Mothers and Obesity in Male Offspring," and appear in the American Journal of Physiology -- Endocrinology and Metabolism, published by the American Physiological Society.
-Methodology
Researchers at the University of Cincinnati designed the study in two parts. In the first part, they established the mouse model that mimics multiparity-induced obesity in humans. In the second part, they examined male offspring of the multiparous females.
The researchers compared one group of mice that gave birth four times with a second group of mice that gave birth only once, some of these at the same age that the first group had its fourth litter and some at a younger age.
The researchers weighed these animals and assessed the size of their fat deposits. They also performed glucose tolerance tests in all the mice and measured biochemical markers of inflammation. Additionally, the researchers performed similar tests in the male offspring of primiparous and multiparous mice, and measured weight, fat deposits, and glucose tolerance. They also measured the expression levels of various genes involved in storing versus using fat.
-Results
The first part of the study showed that giving birth multiple times was a significant contributor to obesity regardless of age, with mice who gave birth multiple times being up to 45 percent heavier than those who had a single litter at the same age that the first animals had their fourth. The multiparous animals had fat deposits several times larger than those in typically-mated primiparous mice, as well as significantly larger glucose spikes after meals, a warning sign for diabetes. Multiparous moms also showed elevated markers for inflammation in numerous body tissues, a condition linked to heart disease, diabetes, cancer, and a variety of other diseases, as compared to the primiparous mice as well as age-matched females fed a high fat diet.
The second part of the study revealed that male offspring of multiparous mice weighed as much as 40 percent more than the male offspring of primiparous mice, despite eating no more food. Interestingly, the differences became apparent when the offspring were older, suggesting that excess energy was stored as fat only after growth rate slowed down. When the researchers examined genes responsible for storing versus using fat, the offspring of multiparous animals appeared to use less fat compared to those of the primiparous animals.
Importance, Implications of the Findings
These findings confirm that in mice, as in humans, giving birth multiple times, regardless of age, can lead to significant weight gain, and inflammation. The results also support the theory that multiple pregnancies induce metabolic stresses on females that have heritable consequences and may be part of an obesity cycle between mothers and offspring.
The authors suggest that finding effective ways to help women lose weight between pregnancies will assist in maintaining their health and that of their children, though additional interventions will likely be required as multiple pregnancies appear to have an adverse effect on women that is independent of her fat mass. "The current studies are important in supporting a healthier, less obese population in that we have defined specific metabolic pathways that are likely involved in the programming of obesity and can be targeted in either the mother or her offspring," the authors say.
**Source: American Physiological Society (APS)
-Methodology
Researchers at the University of Cincinnati designed the study in two parts. In the first part, they established the mouse model that mimics multiparity-induced obesity in humans. In the second part, they examined male offspring of the multiparous females.
The researchers compared one group of mice that gave birth four times with a second group of mice that gave birth only once, some of these at the same age that the first group had its fourth litter and some at a younger age.
The researchers weighed these animals and assessed the size of their fat deposits. They also performed glucose tolerance tests in all the mice and measured biochemical markers of inflammation. Additionally, the researchers performed similar tests in the male offspring of primiparous and multiparous mice, and measured weight, fat deposits, and glucose tolerance. They also measured the expression levels of various genes involved in storing versus using fat.
-Results
The first part of the study showed that giving birth multiple times was a significant contributor to obesity regardless of age, with mice who gave birth multiple times being up to 45 percent heavier than those who had a single litter at the same age that the first animals had their fourth. The multiparous animals had fat deposits several times larger than those in typically-mated primiparous mice, as well as significantly larger glucose spikes after meals, a warning sign for diabetes. Multiparous moms also showed elevated markers for inflammation in numerous body tissues, a condition linked to heart disease, diabetes, cancer, and a variety of other diseases, as compared to the primiparous mice as well as age-matched females fed a high fat diet.
The second part of the study revealed that male offspring of multiparous mice weighed as much as 40 percent more than the male offspring of primiparous mice, despite eating no more food. Interestingly, the differences became apparent when the offspring were older, suggesting that excess energy was stored as fat only after growth rate slowed down. When the researchers examined genes responsible for storing versus using fat, the offspring of multiparous animals appeared to use less fat compared to those of the primiparous animals.
Importance, Implications of the Findings
These findings confirm that in mice, as in humans, giving birth multiple times, regardless of age, can lead to significant weight gain, and inflammation. The results also support the theory that multiple pregnancies induce metabolic stresses on females that have heritable consequences and may be part of an obesity cycle between mothers and offspring.
The authors suggest that finding effective ways to help women lose weight between pregnancies will assist in maintaining their health and that of their children, though additional interventions will likely be required as multiple pregnancies appear to have an adverse effect on women that is independent of her fat mass. "The current studies are important in supporting a healthier, less obese population in that we have defined specific metabolic pathways that are likely involved in the programming of obesity and can be targeted in either the mother or her offspring," the authors say.
**Source: American Physiological Society (APS)
Las referencias al sexo en las redes pueden indicar el momento de iniciación
Saber el momento en el que un hijo o una hija está dispuesto a perder su virginidad es un dato que muchos padres querrían conocer. Ahora lo tienen más fácil gracias a las redes sociales. Al menos eso es lo que se desprende de una nueva investigación que demuestra que las publicaciones públicas de referencias sexuales en Facebook pueden indicar el momento de inicio en el sexo.
Megan Moreno, de la Universidad de Wisconsin (EEUU), es la autora principal del estudio, que ha visto la luz en el 'Journal of Sexual Research' .
"Las redes sociales son inmensamente populares entre los adolescentes y adultos jóvenes, la mayoría tiene acceso a Internet, y la mayoría hace uso diario de él... El contenido sexual forma parte de los perfiles de los adolescentes de muchas de estas redes. De hecho, aproximadamente una cuarta parte de los jóvenes tiene referencias al sexo en su perfil de acceso público. Un ejemplo: 'Marck se puso ayer por la noche...'. O mediante la publicación de sus fotografías en ropa interior. Las redes sociales pueden representar un nuevo lugar en el que explorar el comportamiento sexual de los adolescentes", introducen los autores en su ensayo.
-Experimentación y riesgos
La adolescencia suele ser el "momento de la experimentación y del desarrollo de la identidad, y esta experimentación también puede formar parte de la personalidad que se presenta en los perfiles. Estudios previos muestran que, aproximadamente un 41% de los perfiles contiene referencias al abuso de sustancias y un 24% habla sobre sexo, aunque este último tipo de comentarios puede acarrear consecuencias. Estudios previos han demostrado que la información personal o sexual en internet eleva el riesgo de acoso o 'ciberbullying'", aclaran.
Los científicos llevaron a cabo la investigación mediante el rastreo de perfiles de estudiantes en Facebook con referencias públicas. El trabajo se realizó finalmente con 85 chicos y chicas [la mayoría del sexo femenino (56%) y de origen caucásico (67%)].
El grupo de la doctora Moreno calificó de 'exhibidores' a aquéllos que tenían una o más referencias públicas sexuales en su perfil y como 'no-exhibidores' a los que obviaron este tipo de información.
A todos ellos les remitieron un cuestionario a su email que permitió evaluar su intención de mantener una relación sexual y los comportamientos de riesgo.
En aquéllos que "confesaron no haber tenido nunca encuentros íntimos se evaluó la intención sexual con otro test: aplazamiento de relaciones sexuales (IPS, sus siglas en inglés) que contiene 12 ítems y que ha demostrado su fiabilidad y validad para determinar la intención de iniciarse en el sexo. Los otros test estaban relacionados con la experiencia sexual (oral, vaginal y anal) y con el uso de preservativo", destaca el trabajo.
De los 85 perfiles analizados, 18 contenían referencias sexuales (exhibidores) y la mayoría era de chicos. "Los datos revelan que la intención de iniciarse en el sexo vaginal fue estadísticamente más significativa en los exhibidores que en los no exhibidores. No obstante, no hubo diferencias entre la prevalencia de vida sexual o el número de parejas sexuales entre unos y otros", indican los investigadores.
"La introducción de referencias de sexo en los perfiles de las redes sociales se asocia positivamente con la intención de informar sobre el deseo de iniciar relaciones sexuales. Facebook puede representar un espacio cultural innovador para identificar a los adolescentes que están considerando perder la virginidad y pueden beneficiarse de mensajes educativos sobre las prácticas sexuales de riesgo", determinan los autores.
Padres y médicos siempre buscan pistas para saber cuándo es el momento adecuado para tener 'la charla' sobre sexo con los adolescentes, ha señalado Moreno. Pues, "nuestro estudio sugiere que, si se ha apreciado contenido sexual en las páginas de sus perfiles en las redes sociales, es definitivamente el momento de hablar".
**Publicado en "EL MUNDO"
Megan Moreno, de la Universidad de Wisconsin (EEUU), es la autora principal del estudio, que ha visto la luz en el 'Journal of Sexual Research' .
"Las redes sociales son inmensamente populares entre los adolescentes y adultos jóvenes, la mayoría tiene acceso a Internet, y la mayoría hace uso diario de él... El contenido sexual forma parte de los perfiles de los adolescentes de muchas de estas redes. De hecho, aproximadamente una cuarta parte de los jóvenes tiene referencias al sexo en su perfil de acceso público. Un ejemplo: 'Marck se puso ayer por la noche...'. O mediante la publicación de sus fotografías en ropa interior. Las redes sociales pueden representar un nuevo lugar en el que explorar el comportamiento sexual de los adolescentes", introducen los autores en su ensayo.
-Experimentación y riesgos
La adolescencia suele ser el "momento de la experimentación y del desarrollo de la identidad, y esta experimentación también puede formar parte de la personalidad que se presenta en los perfiles. Estudios previos muestran que, aproximadamente un 41% de los perfiles contiene referencias al abuso de sustancias y un 24% habla sobre sexo, aunque este último tipo de comentarios puede acarrear consecuencias. Estudios previos han demostrado que la información personal o sexual en internet eleva el riesgo de acoso o 'ciberbullying'", aclaran.
Los científicos llevaron a cabo la investigación mediante el rastreo de perfiles de estudiantes en Facebook con referencias públicas. El trabajo se realizó finalmente con 85 chicos y chicas [la mayoría del sexo femenino (56%) y de origen caucásico (67%)].
El grupo de la doctora Moreno calificó de 'exhibidores' a aquéllos que tenían una o más referencias públicas sexuales en su perfil y como 'no-exhibidores' a los que obviaron este tipo de información.
A todos ellos les remitieron un cuestionario a su email que permitió evaluar su intención de mantener una relación sexual y los comportamientos de riesgo.
En aquéllos que "confesaron no haber tenido nunca encuentros íntimos se evaluó la intención sexual con otro test: aplazamiento de relaciones sexuales (IPS, sus siglas en inglés) que contiene 12 ítems y que ha demostrado su fiabilidad y validad para determinar la intención de iniciarse en el sexo. Los otros test estaban relacionados con la experiencia sexual (oral, vaginal y anal) y con el uso de preservativo", destaca el trabajo.
De los 85 perfiles analizados, 18 contenían referencias sexuales (exhibidores) y la mayoría era de chicos. "Los datos revelan que la intención de iniciarse en el sexo vaginal fue estadísticamente más significativa en los exhibidores que en los no exhibidores. No obstante, no hubo diferencias entre la prevalencia de vida sexual o el número de parejas sexuales entre unos y otros", indican los investigadores.
"La introducción de referencias de sexo en los perfiles de las redes sociales se asocia positivamente con la intención de informar sobre el deseo de iniciar relaciones sexuales. Facebook puede representar un espacio cultural innovador para identificar a los adolescentes que están considerando perder la virginidad y pueden beneficiarse de mensajes educativos sobre las prácticas sexuales de riesgo", determinan los autores.
Padres y médicos siempre buscan pistas para saber cuándo es el momento adecuado para tener 'la charla' sobre sexo con los adolescentes, ha señalado Moreno. Pues, "nuestro estudio sugiere que, si se ha apreciado contenido sexual en las páginas de sus perfiles en las redes sociales, es definitivamente el momento de hablar".
**Publicado en "EL MUNDO"
Grape seed extract kills head and neck cancer cells, leaves healthy cells unharmed
Nearly 12,000 people will die of head and neck cancer in the United States this year and worldwide cases will exceed half a million. A study published this week in the journal Carcinogenesis shows that in both cell lines and mouse models, grape seed extract (GSE) kills head and neck squamous cell carcinoma cells, while leaving healthy cells unharmed.
"It's a rather dramatic effect," says Rajesh Agarwal, PhD, investigator at the University of Colorado Cancer Center and professor at the Skaggs School of Pharmaceutical Sciences.
It depends in large part, says Agarwal, on a healthy cell's ability to wait out damage.
"Cancer cells are fast-growing cells," Agarwal says. "Not only that, but they are necessarily fast growing. When conditions exist in which they can't grow, they die."
Grape seed extract creates these conditions that are unfavorable to growth. Specifically, the paper shows that grape seed extract both damages cancer cells' DNA (via increased reactive oxygen species) and stops the pathways that allow repair (as seen by decreased levels of the DNA repair molecules Brca1 and Rad51 and DNA repair foci).
"Yet we saw absolutely no toxicity to the mice, themselves," Agarwal says.
Again, the grape seed extract killed the cancer cells but not the healthy cells.
"I think the whole point is that cancer cells have a lot of defective pathways and they are very vulnerable if you target those pathways. The same is not true of healthy cells," Agarwal says.
The Agarwal Lab hopes to move in the direction of clinical trials of grape seed extract, potentially as an addition to second-line therapies that target head and neck squamous cell carcinoma that has failed a first treatment.
This work was supported by the R01 grants AT003623 from the National Center for Complementary and Alternative Medicine and CA91883 from the National Cancer Institute, NIH.
**Source: University of Colorado Denver
"It's a rather dramatic effect," says Rajesh Agarwal, PhD, investigator at the University of Colorado Cancer Center and professor at the Skaggs School of Pharmaceutical Sciences.
It depends in large part, says Agarwal, on a healthy cell's ability to wait out damage.
"Cancer cells are fast-growing cells," Agarwal says. "Not only that, but they are necessarily fast growing. When conditions exist in which they can't grow, they die."
Grape seed extract creates these conditions that are unfavorable to growth. Specifically, the paper shows that grape seed extract both damages cancer cells' DNA (via increased reactive oxygen species) and stops the pathways that allow repair (as seen by decreased levels of the DNA repair molecules Brca1 and Rad51 and DNA repair foci).
"Yet we saw absolutely no toxicity to the mice, themselves," Agarwal says.
Again, the grape seed extract killed the cancer cells but not the healthy cells.
"I think the whole point is that cancer cells have a lot of defective pathways and they are very vulnerable if you target those pathways. The same is not true of healthy cells," Agarwal says.
The Agarwal Lab hopes to move in the direction of clinical trials of grape seed extract, potentially as an addition to second-line therapies that target head and neck squamous cell carcinoma that has failed a first treatment.
This work was supported by the R01 grants AT003623 from the National Center for Complementary and Alternative Medicine and CA91883 from the National Cancer Institute, NIH.
**Source: University of Colorado Denver
Oxford, Harvard y otras 30 organizaciones coordinan sus bases de datos científicas
La Ciencia, ayudada por las nuevas tecnologías, genera una inmensa cantidad de datos, la mayor parte de las veces heterogéneos y, por eso, difícilmente comparables o accesibles. Por eso, unas 30 organizaciones científicas de todo el mundo se han puesto de acuerdo para crear un nuevo estandard común para la descripción de esta información almacenada en bases de datos sobre temas tan dispares como la genética o el medioambiente.
Los miembros de esta iniciativa, liderada por la Universidad de Oxford (Reino Unido) y el Instituto de Células Madre de Harvard (EEUU), explican esta semana en 'Nature Genetics' la necesidad de adoptar "tecnologías que faciliten la interoperabilidad y promuevan el crecimiento de la cultura del 'open data' común".
"Ahora estamos trabajando juntos para obtener los medios para manejar cantidades enormes de datos que de otra forma serían incompatibles", ha explicado Susanna-Assunta Sansone, líder de grupo del proyecto en la universidad británica. De momento, han puesto en marcha una web a través de la que se podrá acceder a toda la información: ISA Commons.
"Un ejemplo de cómo funciona esto en el Instituto de Células Madre de Harvard es que ahora podemos encontrar la relación entre experimentos con células madre de la sangre de los peces y tumores infantiles", señala Wilson Hide, director de la división de Bioinformática de este organismo.
La columna vertebral de esta nueva forma de archivar información la forman tres categorías que deben utilizar los participantes: "investigación (el contexto del proyecto) , estudio (unidad de investigación) y ensayo (medición analítica)". Sobre ellas "se articulan el descubrimiento, el intercambio y la integración de los datos", explican los responsables del proyecto.
La herramienta podría ser de gran utilidad para las grandes organizaciones, pero también para grupos pequeños que "podrán empezar a almacenar sus datos de laboratorio utilizando este sistema, siguiendo los estándares de la comunidad, sin necesidad de tener un apoyo bioinformático propio", ha subrayado Jules Griffin, de la Universidad de Cambridge. "Es como si Facebook nos permitiera a todos nuestra propia página web; de repente, no necesitas ser un experto en ordenadores para mostrar tu información al resto del mundo".
Los miembros de esta iniciativa, liderada por la Universidad de Oxford (Reino Unido) y el Instituto de Células Madre de Harvard (EEUU), explican esta semana en 'Nature Genetics' la necesidad de adoptar "tecnologías que faciliten la interoperabilidad y promuevan el crecimiento de la cultura del 'open data' común".
"Ahora estamos trabajando juntos para obtener los medios para manejar cantidades enormes de datos que de otra forma serían incompatibles", ha explicado Susanna-Assunta Sansone, líder de grupo del proyecto en la universidad británica. De momento, han puesto en marcha una web a través de la que se podrá acceder a toda la información: ISA Commons.
"Un ejemplo de cómo funciona esto en el Instituto de Células Madre de Harvard es que ahora podemos encontrar la relación entre experimentos con células madre de la sangre de los peces y tumores infantiles", señala Wilson Hide, director de la división de Bioinformática de este organismo.
La columna vertebral de esta nueva forma de archivar información la forman tres categorías que deben utilizar los participantes: "investigación (el contexto del proyecto) , estudio (unidad de investigación) y ensayo (medición analítica)". Sobre ellas "se articulan el descubrimiento, el intercambio y la integración de los datos", explican los responsables del proyecto.
La herramienta podría ser de gran utilidad para las grandes organizaciones, pero también para grupos pequeños que "podrán empezar a almacenar sus datos de laboratorio utilizando este sistema, siguiendo los estándares de la comunidad, sin necesidad de tener un apoyo bioinformático propio", ha subrayado Jules Griffin, de la Universidad de Cambridge. "Es como si Facebook nos permitiera a todos nuestra propia página web; de repente, no necesitas ser un experto en ordenadores para mostrar tu información al resto del mundo".
**Publicado en "EL MUNDO"
Genetics study reveals how bacteria behind serious childhood disease evolve to evade vaccines
Genetics has provided surprising insights into why vaccines used in both the UK and US to combat serious childhood infections can eventually fail. The study, recently published in Nature Genetics, which investigates how bacteria change their disguise to evade the vaccines, has implications for how future vaccines can be made more effective. Pneumococcus (Streptococcus pneumoniae) causes potentially life-threatening diseases including pneumonia and meningitis. Pneumococcal infections are thought to kill around a million young children worldwide each year, though the success of vaccination programmes has led to a dramatic fall in the number of cases in countries such as the UK and US. These vaccines recognise the bacteria by its polysaccharide, the material found on the outside of the bacterial cell. There are over ninety different kinds -- or 'serotypes' -- of the bacteria, each with a different polysaccharide coating.
In 2000, the US introduced a pneumococcal vaccine which targeted seven of the ninety serotypes. This '7-valent' vaccine was extremely effective and had a dramatic effect on reducing disease amongst the age groups targeted. Remarkably, the vaccine has also prevented transmission from young children to adults, resulting in tens of thousands fewer cases of pneumococcal disease each year. The same vaccine was introduced in the UK in 2006 and was similarly successful.
In spite of the success of the vaccine programmes, some pneumococcal strains managed to continue to cause disease by camouflaging themselves from the vaccine. In research funded by the Wellcome Trust, scientists at the University of Oxford and at the Centers for Disease Control and Prevention in Atlanta studied what happened after the introduction of this vaccine in the US. They used the latest genomic techniques combined with epidemiology to understand how different serotypes of the pneumococcus bacteria evolve to replace those targeted by the initial vaccine.
The researchers found bacteria that had evaded the vaccine by swapping the region of the genome responsible for making the polysaccharide coating with the same region from a different serotype, not targeted by the vaccine. This effectively disguised the bacteria, making it invisible to the vaccine. This exchange of genome regions occurred during a process known as recombination, whereby one of the bacteria replaces a piece of its own DNA with a piece from another bacterial type.
Dr Rory Bowden, from the University of Oxford, explains: "Imagine that each strain of the pneumococcus bacteria is a class of schoolchildren, all wearing the school uniform. If a boy steals from his corner shop, a policeman -- in this case the vaccine -- can easily identify which school he belongs to by looking at his uniform. But if the boy swaps his sweater with a friend from another school, the policemen will no longer be able to recognise him and he can escape. This is how the pneumococcus bacteria evade detection by the vaccine."
Dr Bowden and colleagues identified a number of recombined serotypes that had managed to evade the vaccine. One in particular grew in frequency and spread across the US from east to west over several years. They also showed that during recombination, the bacteria also traded a number of other parts of the genome at the same time, a phenomenon never before observed in natural populations of pneumococcus. This is of particular concern as recombination involving multiple fragments of DNA allows rapid simultaneous exchange of key regions of the genome within the bug, potentially allowing it to quickly develop antibiotic resistance.
The original 7-valent vaccine in the US has now been replaced by a 13-valent vaccine, which targets thirteen different serotypes, including the particular type which had escaped the original vaccine. In the UK, the 7-valent vaccine resulted in a substantial drop in disease overall. This overall effect was a mixture of a large drop in frequency of the serotypes targeted by the vaccine with some growth in serotypes not targeted by the vaccine. The 13-valent vaccine was introduced in the UK in 2010.
Derrick Crook, Professor of Microbiology at the University of Oxford and Infection Control Doctor at the Oxford University Hospitals NHS Trust, adds: "Childhood vaccines are very effective at reducing disease and death at a stage in our lives when we are susceptible to serious infections. Understanding what makes a vaccine successful and what can cause it to fail is important. We should now be able to understand better what happens when a pneumococcal vaccine is introduced into a new population. Our work suggests that current strategies for developing new vaccines are largely effective but may not have long term effects that are as successful as hoped."
Dr Bernard Beall, a scientist at the Centers for Disease Control and Prevention commented: "The current vaccine strategy of targeting predominant pneumococcal serotypes is extremely effective, however our observations indicate that the organism will continue to adapt to this strategy with some measurable success."
The Wellcome Trust, which part-funded this research, views combating infectious disease and maximising the health benefits of genetic research as two of its strategic priorities. Dr Michael Dunn, Head of Molecular and Physiological Sciences at the Wellcome Trust commented: "New technologies allow us to rapidly sequence disease-causing organisms and see how they evolve. Coupled with collaborations with epidemiologists, we can then track how they spread and monitor the potential impact this will have on vaccine efficiency. This will provide useful lessons for vaccine implementation strategies."
** Source: Wellcome Trust
In 2000, the US introduced a pneumococcal vaccine which targeted seven of the ninety serotypes. This '7-valent' vaccine was extremely effective and had a dramatic effect on reducing disease amongst the age groups targeted. Remarkably, the vaccine has also prevented transmission from young children to adults, resulting in tens of thousands fewer cases of pneumococcal disease each year. The same vaccine was introduced in the UK in 2006 and was similarly successful.
In spite of the success of the vaccine programmes, some pneumococcal strains managed to continue to cause disease by camouflaging themselves from the vaccine. In research funded by the Wellcome Trust, scientists at the University of Oxford and at the Centers for Disease Control and Prevention in Atlanta studied what happened after the introduction of this vaccine in the US. They used the latest genomic techniques combined with epidemiology to understand how different serotypes of the pneumococcus bacteria evolve to replace those targeted by the initial vaccine.
The researchers found bacteria that had evaded the vaccine by swapping the region of the genome responsible for making the polysaccharide coating with the same region from a different serotype, not targeted by the vaccine. This effectively disguised the bacteria, making it invisible to the vaccine. This exchange of genome regions occurred during a process known as recombination, whereby one of the bacteria replaces a piece of its own DNA with a piece from another bacterial type.
Dr Rory Bowden, from the University of Oxford, explains: "Imagine that each strain of the pneumococcus bacteria is a class of schoolchildren, all wearing the school uniform. If a boy steals from his corner shop, a policeman -- in this case the vaccine -- can easily identify which school he belongs to by looking at his uniform. But if the boy swaps his sweater with a friend from another school, the policemen will no longer be able to recognise him and he can escape. This is how the pneumococcus bacteria evade detection by the vaccine."
Dr Bowden and colleagues identified a number of recombined serotypes that had managed to evade the vaccine. One in particular grew in frequency and spread across the US from east to west over several years. They also showed that during recombination, the bacteria also traded a number of other parts of the genome at the same time, a phenomenon never before observed in natural populations of pneumococcus. This is of particular concern as recombination involving multiple fragments of DNA allows rapid simultaneous exchange of key regions of the genome within the bug, potentially allowing it to quickly develop antibiotic resistance.
The original 7-valent vaccine in the US has now been replaced by a 13-valent vaccine, which targets thirteen different serotypes, including the particular type which had escaped the original vaccine. In the UK, the 7-valent vaccine resulted in a substantial drop in disease overall. This overall effect was a mixture of a large drop in frequency of the serotypes targeted by the vaccine with some growth in serotypes not targeted by the vaccine. The 13-valent vaccine was introduced in the UK in 2010.
Derrick Crook, Professor of Microbiology at the University of Oxford and Infection Control Doctor at the Oxford University Hospitals NHS Trust, adds: "Childhood vaccines are very effective at reducing disease and death at a stage in our lives when we are susceptible to serious infections. Understanding what makes a vaccine successful and what can cause it to fail is important. We should now be able to understand better what happens when a pneumococcal vaccine is introduced into a new population. Our work suggests that current strategies for developing new vaccines are largely effective but may not have long term effects that are as successful as hoped."
Dr Bernard Beall, a scientist at the Centers for Disease Control and Prevention commented: "The current vaccine strategy of targeting predominant pneumococcal serotypes is extremely effective, however our observations indicate that the organism will continue to adapt to this strategy with some measurable success."
The Wellcome Trust, which part-funded this research, views combating infectious disease and maximising the health benefits of genetic research as two of its strategic priorities. Dr Michael Dunn, Head of Molecular and Physiological Sciences at the Wellcome Trust commented: "New technologies allow us to rapidly sequence disease-causing organisms and see how they evolve. Coupled with collaborations with epidemiologists, we can then track how they spread and monitor the potential impact this will have on vaccine efficiency. This will provide useful lessons for vaccine implementation strategies."
** Source: Wellcome Trust
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