Mayor riesgo cardiovascular y ahora también más probabilidades de demencia. Según un estudio publicado en 'Neurology', las personas con diabetes son dos veces más propensas al deterioro cognitivo que aquellas que tienen niveles normales de azúcar.
Entre los estudios realizados hasta la fecha, algunos confirman la diabetes como un factor de riesgo independiente de cualquier tipo de demencia, otros sólo encuentran asociación con la enfermedad de Alzheimer y otros no confirman ninguna relación. Con el objetivo de resolver esta disparidad de resultados, señalan los autores de la actual investigación, "hemos realizado un análisis prospectivo con un total de 1.017 japoneses (a partir de los 60 años) durante 15 años (de 1988 a 2003)".
Se sometieron a pruebas de tolerancia a la glucosa para determinar si tenían diabetes y además, en el transcurso del estudio, también fueron monitorizados para evaluar su función cognitiva a través de técnicas de neuroimagen.
"El desarrollo de este tipo de estudios tan largos resulta muy difícil de hacer. Se trata de un buen trabajo que refuerza la hipótesis que vincula la intolerancia a la glucosa con el deterioro cognitivo", señala Ambrosio Miralles, jefe de sección de Neurología del Hospital Infanta Sofía de Madrid. Una de las pocas limitaciones que tiene, añade, es que las clasificaciones que utilizan para diagnosticar la demencia y la diabetes son de hace más de 20 años.
En total, 232 pacientes desarrollaron demencia (105 con Alzheimer, 65 con demencia vascular y 62 con otros tipos de demencia). Según las conclusiones de esta investigación, los individuos con diabetes tenían un riesgo casi del doble de sufrir deterioro cognitivo en los siguientes 15 años.
Los investigadores también valoraron la influencia que podían tener otros factores de riesgo, como la hipertensión, el colesterol, el índice de masa corporal, la actividad física, el tabaco o el consumo de alcohol, pero los resultados continuaron en la misma línea. "Las probabilidades de demencia seguían siendo más altas para las personas con diabetes y también para aquellas que no tenían esta enfermedad, pero sí un estado inicial de intolerancia a la glucosa".
La razón, tal y como explican los expertos, basándose en estudios previos, estriba en que "las personas con diabetes tienen alta cantidad de un tipo de toxinas que favorecen la formación de placas amiloide y ovillos característicos del Alzheimer". Otra de las hipótesis, apunta el neurólogo español, es que altos niveles de azúcar pueden producir daños vasculares responsables de la demencia vascular.
La asociación entre este último tipo de deterioro cognitivo y la diabetes se mostró más débil en este estudio, "puede deberse a los pocos casos que observamos de demencia vascular". En cualquier caso, añaden los autores, aunque queda claro su papel como factor independiente, "la diabetes, a través de otros desencadenantes como la hipertensión, sí que incrementa las probabilidades de esta alteración".
-Factor de riesgo modificable
Este hallazgo "subraya la necesidad de considerar la diabetes como un factor de riesgo independiente para todos los tipos de demencia y, probablemente también de la vascular", asegura el principal autor de la investigación, Yutaka Kiyohara, de la Universidad de Kyushu (Fukuoka, Japón). "Se trata de una alteración muy común que afecta cada vez a más personas".
Según la Encuesta Europea sobre Calidad de Vida de estos pacientes -presentada en el Congreso Europeo de Diabetes que se celebra estos días en Lisboa (Portugal)-, hasta un 40% de los afectados no tiene controlada su enfermedad.
"Están tratados, pero no controlados", explica Olga González, médico adjunto del servicio de Endocrinología del Hospital Ramón y Cajal de Madrid, que participa estos días en dicho congreso. "Bien por un cambio de tratamiento, a la hora de subir las dosis, por un mal cumplimiento de la dieta o la medicación o por la inercia de muchos médicos que a veces tardan varios años (una media de 2,3) en cambiar de fármaco".
Dado el riesgo cardiovascular que entraña y las probabilidades de demencia que conlleva, aseveran los investigadores japoneses, controlar la diabetes es ahora más importante que nunca.
**publicado en "EL MUNDO"
20 September 2011
Mammography use up for US immigrants
While mammography rates have improved among foreign-born women residing in the United States, these women are still less likely to have undergone breast cancer screening than native-born U.S. women. These study results were presented at the Fourth AACR Conference on The Science of Cancer Health Disparities, held Sept. 18-21, 2011, in Washington, D.C.
Researchers at Pennsylvania State University believe that lack of access to health insurance and a regular source of health care are important factors related to the lower percentage of mammography screening among U.S. immigrants.
"There is progress, overall, in use of mammography among foreign-born women in the United States, but there is still a lot of work to do to improve their use of recommended breast cancer screening," said the study's lead researcher Nengliang (Aaron) Yao, a doctoral student in health policy and administration.
Yao and colleagues used data from the 2000 and 2008 National Health Interview Survey, conducted by the National Center for Health Statistics and administered by the U.S. Census Bureau, to look at mammography screening among immigrants and factors associated with use. Information on immigrants' legal status was not included in the survey.
Screening rates among immigrants increased from about 60.2 percent in 2000 to 65.5 percent in 2008, and disparities in the use of mammography between immigrants and native women narrowed from 11.2 percent in 2000 to 3.4 percent in 2008.
Immigrants who resided in the United States a decade or longer had markedly higher mammography rates compared to those who had been in the country less than a decade (64.7 percent versus 39.3 percent in 2000; 67.9 percent versus 55.7 percent in 2008).
Insurance coverage played an important role in predicting who would receive screening. By 2008, immigrant women with public insurance had odds of receiving a mammogram that were twice those of uninsured immigrant women, Yao said, and those with private insurance had odds more than 2.5 times higher than uninsured women.
In addition, having a regular source of health care also became a more important predictor of mammography use over time. In 2008, women with a regular source of care had odds of receiving screening that were more than twice as high as those for women without a regular source of care.
Yao added that there has been an increase in "culturally and linguistically appropriate subsidized programs," such as those developed by the CDC's National Breast and Cervical Cancers Early Detection Program that encourage foreign-born women to seek a mammogram, which may have led to increased use of the test.
"As much progress as we have made, we still need to improve access to mammography screening for immigrant women, as well as for women overall," he said.
*Source: American Association for Cancer Research
Researchers at Pennsylvania State University believe that lack of access to health insurance and a regular source of health care are important factors related to the lower percentage of mammography screening among U.S. immigrants.
"There is progress, overall, in use of mammography among foreign-born women in the United States, but there is still a lot of work to do to improve their use of recommended breast cancer screening," said the study's lead researcher Nengliang (Aaron) Yao, a doctoral student in health policy and administration.
Yao and colleagues used data from the 2000 and 2008 National Health Interview Survey, conducted by the National Center for Health Statistics and administered by the U.S. Census Bureau, to look at mammography screening among immigrants and factors associated with use. Information on immigrants' legal status was not included in the survey.
Screening rates among immigrants increased from about 60.2 percent in 2000 to 65.5 percent in 2008, and disparities in the use of mammography between immigrants and native women narrowed from 11.2 percent in 2000 to 3.4 percent in 2008.
Immigrants who resided in the United States a decade or longer had markedly higher mammography rates compared to those who had been in the country less than a decade (64.7 percent versus 39.3 percent in 2000; 67.9 percent versus 55.7 percent in 2008).
Insurance coverage played an important role in predicting who would receive screening. By 2008, immigrant women with public insurance had odds of receiving a mammogram that were twice those of uninsured immigrant women, Yao said, and those with private insurance had odds more than 2.5 times higher than uninsured women.
In addition, having a regular source of health care also became a more important predictor of mammography use over time. In 2008, women with a regular source of care had odds of receiving screening that were more than twice as high as those for women without a regular source of care.
Yao added that there has been an increase in "culturally and linguistically appropriate subsidized programs," such as those developed by the CDC's National Breast and Cervical Cancers Early Detection Program that encourage foreign-born women to seek a mammogram, which may have led to increased use of the test.
"As much progress as we have made, we still need to improve access to mammography screening for immigrant women, as well as for women overall," he said.
*Source: American Association for Cancer Research
Londres: Termina con éxito la separación de dos bebés sudaneses unidos por la cabeza
Los médicos del hospital londinense Great Ormond Street han conseguido separar con éxito a dos niñas siamesas sudanesas de once meses de edad que estaban unidas por la cabeza, según informó este lunes el diario británico «The Guardian».
Ritag y Rital Gaboura han sido sometidas a cuatro operaciones de alto riesgo, dos en mayo, una en julio y la última el pasado 15 de agosto. Las dos niñas habían nacido mediante cesárea el 22 de septiembre de 2010 en Jartum, capital de Sudán, y fueron trasladadas el pasado mes de abril en un avión a Londres gracias al apoyo de la organización caritativa Facing the World.
Los nacimientos de bebés unidos por la cabeza («craneópagos») suceden en uno de cada 2,5 millones de nacimientos. La operación de separación es particularmente peligrosa por la gran cantidad de sangre que fluye entre los dos cerebros.
No obstante, si no se opera los riesgos son también grandes, dado que la sangre casi nunca circula de forma uniforme y cabe la posibilidad de que el corazón del hermano más fuerte acabe succionando la sangre del otro.
Según Facing the World, la tasa de supervivencia de este tipo de siameses después de la infancia es de uno por cada diez millones, El corazón de Ritag, añadió, ya había empezado a sufrir problemas graves cuando la familia llegó a Reino Unido.
«La supervivencia de los gemelos en estas condiciones es extremadamente escasa», declaró el cirujano jefe, David Dunaway. «La operación presentaba innumerables problemas y todos éramos conscientes de nuestra responsabilidad ante la familia y ante las dos pequeñas», agregó.
Las operaciones, pese a su éxito y pese a que no presentó complicaciones especiales, pueden dejar secuelas neurológicas, pero los expertos esperan que Rital y Ritag gocen de buena salud.
«Dentro de algunos días, las gemelas regresarán a la planta normal y jugarán como siempre», declaró Sarah Driver-Jowitt, de Facing the World. Los dos padres -cuyas identidades no han sido reveladas- regresarán pronto a casa «con dos niñas sanas y separadas», manifestó.
Ritag y Rital Gaboura han sido sometidas a cuatro operaciones de alto riesgo, dos en mayo, una en julio y la última el pasado 15 de agosto. Las dos niñas habían nacido mediante cesárea el 22 de septiembre de 2010 en Jartum, capital de Sudán, y fueron trasladadas el pasado mes de abril en un avión a Londres gracias al apoyo de la organización caritativa Facing the World.
Los nacimientos de bebés unidos por la cabeza («craneópagos») suceden en uno de cada 2,5 millones de nacimientos. La operación de separación es particularmente peligrosa por la gran cantidad de sangre que fluye entre los dos cerebros.
No obstante, si no se opera los riesgos son también grandes, dado que la sangre casi nunca circula de forma uniforme y cabe la posibilidad de que el corazón del hermano más fuerte acabe succionando la sangre del otro.
Según Facing the World, la tasa de supervivencia de este tipo de siameses después de la infancia es de uno por cada diez millones, El corazón de Ritag, añadió, ya había empezado a sufrir problemas graves cuando la familia llegó a Reino Unido.
«La supervivencia de los gemelos en estas condiciones es extremadamente escasa», declaró el cirujano jefe, David Dunaway. «La operación presentaba innumerables problemas y todos éramos conscientes de nuestra responsabilidad ante la familia y ante las dos pequeñas», agregó.
Las operaciones, pese a su éxito y pese a que no presentó complicaciones especiales, pueden dejar secuelas neurológicas, pero los expertos esperan que Rital y Ritag gocen de buena salud.
«Dentro de algunos días, las gemelas regresarán a la planta normal y jugarán como siempre», declaró Sarah Driver-Jowitt, de Facing the World. Los dos padres -cuyas identidades no han sido reveladas- regresarán pronto a casa «con dos niñas sanas y separadas», manifestó.
**AGENCIAS Y FOTO DE "REUTERS"
To ditch dessert, feed the brain
If the brain goes hungry, Twinkies look a lot better, a study led by researchers at Yale University and the University of Southern California has found. Brain imaging scans show that when glucose levels drop, an area of the brain known to regulate emotions and impulses loses the ability to dampen desire for high-calorie food, according to the study published online September 19 in The Journal of Clinical Investigation.
"Our prefrontal cortex is a sucker for glucose," said Rajita Sinha, the Foundations Fund Professor of Psychiatry, and professor in the Department of Neurobiology and the Yale Child Study Center, one of the senior authors of the research.
The Yale team manipulated glucose levels intravenously and monitored changes in blood sugar levels while subjects were shown pictures of high-calorie food, low-calorie food and non-food as they underwent fMRI scans.
When glucose levels drop, an area of the brain called the hypothalamus senses the change. Other regions called the insula and striatum associated with reward are activated, inducing a desire to eat, the study found. The most pronounced reaction to reduced glucose levels was seen in the prefrontal cortex. When glucose is lowered, the prefrontal cortex seemed to lose its ability to put the brakes upon increasingly urgent signals to eat generated in the striatum. This weakened response was particularly striking in the obese when shown high-calorie foods.
"This response was quite specific and more dramatic in the presence of high-calorie foods," Sinha said.
"Our results suggest that obese individuals may have a limited ability to inhibit the impulsive drive to eat, especially when glucose levels drop below normal," commented Kathleen Page, assistant professor of medicine at the University of Southern California and one of the lead authors of the paper.
A similarly robust response to high-calorie food was also seen in the striatum, which became hyperactive when glucose was reduced. However, the levels of the stress hormone cortisol seemed to play a more significant role than glucose in activating the brain's reward centers, note the researchers. Sinha suggests that the stress associated with glucose drops may play a key role in activating the striatum.
"The key seems to be eating healthy foods that maintain glucose levels," Sinha said. "The brain needs its food."
"Our prefrontal cortex is a sucker for glucose," said Rajita Sinha, the Foundations Fund Professor of Psychiatry, and professor in the Department of Neurobiology and the Yale Child Study Center, one of the senior authors of the research.
The Yale team manipulated glucose levels intravenously and monitored changes in blood sugar levels while subjects were shown pictures of high-calorie food, low-calorie food and non-food as they underwent fMRI scans.
When glucose levels drop, an area of the brain called the hypothalamus senses the change. Other regions called the insula and striatum associated with reward are activated, inducing a desire to eat, the study found. The most pronounced reaction to reduced glucose levels was seen in the prefrontal cortex. When glucose is lowered, the prefrontal cortex seemed to lose its ability to put the brakes upon increasingly urgent signals to eat generated in the striatum. This weakened response was particularly striking in the obese when shown high-calorie foods.
"This response was quite specific and more dramatic in the presence of high-calorie foods," Sinha said.
"Our results suggest that obese individuals may have a limited ability to inhibit the impulsive drive to eat, especially when glucose levels drop below normal," commented Kathleen Page, assistant professor of medicine at the University of Southern California and one of the lead authors of the paper.
A similarly robust response to high-calorie food was also seen in the striatum, which became hyperactive when glucose was reduced. However, the levels of the stress hormone cortisol seemed to play a more significant role than glucose in activating the brain's reward centers, note the researchers. Sinha suggests that the stress associated with glucose drops may play a key role in activating the striatum.
"The key seems to be eating healthy foods that maintain glucose levels," Sinha said. "The brain needs its food."
**Source: Yale University
NIH scientists find earliest known evidence of 1918 influenza pandemic
Examination of lung tissue and other autopsy material from 68 American soldiers who died of respiratory infections in 1918 has revealed that the influenza virus that eventually killed 50 million people worldwide was circulating in the United States at least four months before the 1918 influenza reached pandemic levels that fall. The study, using tissues preserved since 1918, was led by Jeffery K. Taubenberger, M.D., Ph.D., of the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health. The researchers found proteins and genetic material from the 1918 influenza virus in specimens from 37 of the soldiers, including four who died between May and August 1918, months before the pandemic peaked. These four cases are the earliest 1918 pandemic influenza cases they know to be documented anywhere in the world, the scientists say.
The clinical disease and tissue damage seen in the pre-pandemic cases were indistinguishable from those evident in cases that occurred during the height of the pandemic. This suggests, says Dr. Taubenberger, that over the course of the pandemic, the virus did not undergo a dramatic change that could explain the unusually high mortality it ultimately caused.
In the current study, the autopsy materials showed that the virus replicated not only in the upper respiratory tract but also the lower respiratory tract, in a pattern very similar to that of the 2009 pandemic influenza virus. The team also found evidence that two virus variants were circulating in 1918. In one, a key viral protein called hemagglutinin bound well to receptors on human respiratory cells, while the hemagglutinin from the other variant bound less efficiently. Despite this difference in binding ability, both viruses caused similar disease symptoms and replicated in a similar pattern within cells lining the respiratory tract, suggesting that differences in hemagglutinin binding capacity alone do not fully explain the unusually high mortality seen in the 1918 pandemic.
Bacterial co-infections were found in all 68 cases studied, the researchers noted. The role played by bacterial co-infections, such as bacterial pneumonia, in contributing to deaths in the 1918 pandemic was previously described by Dr. Taubenberger and his colleagues in a 2008 study. According to the study authors, the new data underscore the crucial role that bacterial infections can play in conjunction with any influenza virus, whether historic or future, and the need for public health officials to prepare to prevent, detect and treat bacterial co-infections during future influenza outbreaks.
**Source: NIH/National Institute of Allergy and Infectious Diseases
The clinical disease and tissue damage seen in the pre-pandemic cases were indistinguishable from those evident in cases that occurred during the height of the pandemic. This suggests, says Dr. Taubenberger, that over the course of the pandemic, the virus did not undergo a dramatic change that could explain the unusually high mortality it ultimately caused.
In the current study, the autopsy materials showed that the virus replicated not only in the upper respiratory tract but also the lower respiratory tract, in a pattern very similar to that of the 2009 pandemic influenza virus. The team also found evidence that two virus variants were circulating in 1918. In one, a key viral protein called hemagglutinin bound well to receptors on human respiratory cells, while the hemagglutinin from the other variant bound less efficiently. Despite this difference in binding ability, both viruses caused similar disease symptoms and replicated in a similar pattern within cells lining the respiratory tract, suggesting that differences in hemagglutinin binding capacity alone do not fully explain the unusually high mortality seen in the 1918 pandemic.
Bacterial co-infections were found in all 68 cases studied, the researchers noted. The role played by bacterial co-infections, such as bacterial pneumonia, in contributing to deaths in the 1918 pandemic was previously described by Dr. Taubenberger and his colleagues in a 2008 study. According to the study authors, the new data underscore the crucial role that bacterial infections can play in conjunction with any influenza virus, whether historic or future, and the need for public health officials to prepare to prevent, detect and treat bacterial co-infections during future influenza outbreaks.
**Source: NIH/National Institute of Allergy and Infectious Diseases
Científicos catalanes diseñan una vacuna preventiva con fragmentos de proteínas capaces de detener el VIH
El SIDA se controla bien pero no tiene curación y las tasas de infección se mantienen casi intactas desde hace treinta años. Por este motivo, más allá del tratamiento farmacológico con inhibidores, los esfuerzos de los investigadores se han centrado en hallar una vacuna eficaz capaz de prevenir la enfermedad y combatirla. Investigadores del Hivacat —proyecto de Investigación de la Vacuna del VIH en Cataluña que codirigen los doctores Josep Maria Gatell (Hospital Clínic-Idibaps) y Bonaventura Clotet (Irsi-Caixa) y en el que participan los laboratorios Esteve y la Generalitat— han dado un paso importante al hallar un antígeno capaz de estimular una amplia respuesta inmunitaria eficaz contra el virus causante de la enfermedad. El alto potencial de este nuevo candidado a vacuna, que se está experimentando en animales (ya se ha probado con éxito en ratones, ahora se ensayará con cerdos y conejos) y en dos años saltará a humanos, es que combina dos reacciones: estimula mecanismos de inmunidad que hacen que el cuerpo genere anticuerpos, y, a su vez, hace que se activen células del sistema inmunitario capaces de destruir el VIH.
Gatell recordó que el Hivacat trabaja con otros candidatos a vacuna, dos de ellos en fase de prueba con humanos. Avanzó también que Barcelona será la sede de Congreso mundial de la vacuna en 2013. Por su parte, Françoise Barré-Sinoussi, Nobel de Medicina en 2008 por descubrir el VIH, reconoció que su gran sueño es vivir lo suficiente para ver una vacuna eficaz. «Sea la que sea, —dijo— debe tener los componentes de la del Hivacat».
**Publicado en "VOCENTO"
Gatell recordó que el Hivacat trabaja con otros candidatos a vacuna, dos de ellos en fase de prueba con humanos. Avanzó también que Barcelona será la sede de Congreso mundial de la vacuna en 2013. Por su parte, Françoise Barré-Sinoussi, Nobel de Medicina en 2008 por descubrir el VIH, reconoció que su gran sueño es vivir lo suficiente para ver una vacuna eficaz. «Sea la que sea, —dijo— debe tener los componentes de la del Hivacat».
**Publicado en "VOCENTO"
Association found between stress and breast cancer aggressiveness
Psychosocial stress could play a role in the etiology of breast cancer aggressiveness, particularly among minority populations, according to study results presented at the Fourth AACR Conference on The Science of Cancer Health Disparities, held here from Sept. 18-21, 2011. "We found that after diagnosis, black and Hispanic breast cancer patients reported higher levels of stress than whites, and that stress was associated with tumor aggressiveness," said Garth H. Rauscher, Ph.D., associate professor of epidemiology in the division of epidemiology and biostatistics at the School of Public Health, University of Illinois at Chicago.
Rauscher and colleagues studied patient-reported perceptions of fear, anxiety and isolation, together referred to as psychosocial stress, and associations with breast cancer aggressiveness. He cautioned that patients' stress levels were examined two to three months post-diagnosis.
The study included 989 breast cancer patients who were recently diagnosed; of those, 411 were non-Hispanic black, 397 were non-Hispanic white, and 181 were Hispanic. Results showed that psychosocial stress scores were higher for both black and Hispanic patients compared to white patients.
"Those who reported higher levels of stress tended to have more aggressive tumors. However, what we don't know is if we had asked them the same question a year or five years before diagnosis, would we have seen the same association between stress and breast cancer aggressiveness?
"It's not clear what's driving this association. It may be that the level of stress in these patients' lives influenced tumor aggressiveness. It may be that being diagnosed with a more aggressive tumor, with a more worrisome diagnosis and more stressful treatments, influenced reports of stress. It may be that both of these are playing a role in the association. We don't know the answer to that question," Rauscher said.
**Source: American Association for Cancer Research
Rauscher and colleagues studied patient-reported perceptions of fear, anxiety and isolation, together referred to as psychosocial stress, and associations with breast cancer aggressiveness. He cautioned that patients' stress levels were examined two to three months post-diagnosis.
The study included 989 breast cancer patients who were recently diagnosed; of those, 411 were non-Hispanic black, 397 were non-Hispanic white, and 181 were Hispanic. Results showed that psychosocial stress scores were higher for both black and Hispanic patients compared to white patients.
"Those who reported higher levels of stress tended to have more aggressive tumors. However, what we don't know is if we had asked them the same question a year or five years before diagnosis, would we have seen the same association between stress and breast cancer aggressiveness?
"It's not clear what's driving this association. It may be that the level of stress in these patients' lives influenced tumor aggressiveness. It may be that being diagnosed with a more aggressive tumor, with a more worrisome diagnosis and more stressful treatments, influenced reports of stress. It may be that both of these are playing a role in the association. We don't know the answer to that question," Rauscher said.
**Source: American Association for Cancer Research
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