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30 December 2011

Diet patterns may keep brain from shrinking

People with diets high in several vitamins or in omega 3 fatty acids are less likely to have the brain shrinkage associated with Alzheimer's disease than people whose diets are not high in those nutrients, according to a new study published in the December 28, 2011, online issue of Neurology®, the medical journal of the American Academy of Neurology. Those with diets high in omega 3 fatty acids and in vitamins C, D, E and the B vitamins also had higher scores on mental thinking tests than people with diets low in those nutrients. These omega 3 fatty acids and vitamin D are primarily found in fish. The B vitamins and antioxidants C and E are primarily found in fruits and vegetables.
In another finding, the study showed that people with diets high in trans fats were more likely to have brain shrinkage and lower scores on the thinking and memory tests than people with diets low in trans fats. Trans fats are primarily found in packaged, fast, fried and frozen food, baked goods and margarine spreads.
The study involved 104 people with an average age of 87 and very few risk factors for memory and thinking problems. Blood tests were used to determine the levels of various nutrients present in the blood of each participant. All of the participants also took tests of their memory and thinking skills. A total of 42 of the participants had MRI scans to measure their brain volume.
Overall, the participants had good nutritional status, but seven percent were deficient in vitamin B12 and 25 percent were deficient in vitamin D.
Study author Gene Bowman, ND, MPH, of Oregon Health & Science University in Portland and a member of the American Academy of Neurology, said that the nutrient biomarkers in the blood accounted for a significant amount of the variation in both brain volume and thinking and memory scores. For the thinking and memory scores, the nutrient biomarkers accounted for 17 percent of the variation in the scores. Other factors such as age, number of years of education and high blood pressure accounted for 46 percent of the variation. For brain volume, the nutrient biomarkers accounted for 37 percent of the variation.
"These results need to be confirmed, but obviously it is very exciting to think that people could potentially stop their brains from shrinking and keep them sharp by adjusting their diet," Bowman said.
The study was the first to use nutrient biomarkers in the blood to analyze the effect of diet on memory and thinking skills and brain volume. Previous studies have looked at only one or a few nutrients at a time or have used questionnaires to assess people's diet. But questionnaires rely on people's memory of their diet, and they also do not account for how much of the nutrients are absorbed by the body, which can be an issue in the elderly.

**Source: American Academy of Neurology

New clues as to why some older people may be losing their memory

New research links 'silent strokes,' or small spots of dead brain cells, found in about one out of four older adults to memory loss in the elderly. The study is published in the January 3, 2012, print issue of Neurology®, the medical journal of the American Academy of Neurology. "The new aspect of this study of memory loss in the elderly is that it examines silent strokes and hippocampal shrinkage simultaneously," said study author Adam M. Brickman, PhD, of the Taub Institute for Research on Alzheimer's Disease and the Aging Brain at Columbia University Medical Center in New York.
For the study, a group of 658 people ages 65 and older and free of dementia were given MRI brain scans. Participants also underwent tests that measured their memory, language, speed at processing information and visual perception. A total of 174 of the participants had silent strokes.
The study found people with silent strokes scored somewhat worse on memory tests than those without silent strokes. This was true whether or not people had a small hippocampus, which is the memory center of the brain.
"Given that conditions like Alzheimer's disease are defined mainly by memory problems, our results may lead to further insight into what causes symptoms and the development of new interventions for prevention. Since silent strokes and the volume of the hippocampus appeared to be associated with memory loss separately in our study, our results also support stroke prevention as a means for staving off memory problems," said Brickman.
The study was supported by the National Institutes of Health.

*Source: American Academy of Neurology

Lo peor y lo mejor de 2011 para Médicos sin Fronteras

En estos días es habitual recordar lo mejor y peor del año que termina y Médicos Sin Fronteras (MSF) ha hecho lo propio con un informe sobre las diez noticias más relevantes del año relacionadas con el acceso a los medicamentos. Y 2011 nos deja con un poco de todo:
Desde aquellas que han supuesto un importante avance en la salud, entre las que destaca la confirmación de que mediante el tratamiento precoz a personas con VIH no sólo se salvan vidas, sino que se puede reducir el riesgo de transmisión del virus hasta en un 96%.
Otras que, aunque buenas, tienen sus matices, como cuando los grandes compradores mundiales de vacunas hicieron públicos los precios a los que las adquirían, con lo que se espera que la competencia haga que se reduzcan los precios.
Y luego están las que sólo se pueden calificar de malas. Ejemplo de ellas fue cuando el Fondo Mundial de Luchas contra el Sida, la Tuberculosis y la Malaria cancelaba su ronda anual de financiación porque los donantes no habían desembolsado sus aportaciones correspondientes.

Breast cancer survivors benefit from practicing Mindfulness-based Stress Reduction



Women recently diagnosed with breast cancer have higher survival rates than those diagnosed in previous decades, according to the American Cancer Society. However, survivors continue to face health challenges after their treatments end. Previous research reports as many as 50 percent of breast cancer survivors are depressed. Now, University of Missouri researchers in the Sinclair School of Nursing say a meditation technique can help breast cancer survivors improve their emotional and physical well-being. Yaowarat Matchim, a former nursing doctoral student; Jane Armer, professor of nursing; and Bob Stewart, professor emeritus of education and adjunct faculty in nursing, found that breast cancer survivors' health improved after they learned Mindfulness-Based Stress Reduction (MBSR), a type of mindfulness training that incorporates meditation, yoga and physical awareness.
"MBSR is another tool to enhance the lives of breast cancer survivors," Armer said. "Patients often are given a variety of options to reduce stress, but they should choose what works for them according to their lifestyles and belief systems."
The MBSR program consists of group sessions throughout a period of eight to ten weeks. During the sessions, participants practice meditation skills, discuss how bodies respond to stress and learn coping techniques. The researchers found that survivors who learned MBSR lowered their blood pressure, heart rate and respiratory rate. In addition, participants' mood improved, and their level of mindfulness increased after taking the class. Armer says, for best results, participants should continue MBSR after the class ends to maintain the positive effects.
"Mindfulness-based meditation, ideally, should be practiced every day or at least on a routine schedule," Armer said. "MBSR teaches patients new ways of thinking that will give them short- and long-term benefits."
Armer says the non-pharmaceutical approach works best as a complement to other treatment options such as chemotherapy, radiation and surgery.
"Post diagnosis, breast cancer patients often feel like they have no control over their lives," Armer said. "Knowing that they can control something -- such as meditation -- and that it will improve their health, gives them hope that life will be normal again."
The study, "Effects of Mindfulness-Based Stress Reduction (MBSR) on Health Among Breast Cancer Survivors," was published in the Western Journal of Nursing Research.



EEUU: Una guía reordena cómo deben hacerse las pruebas de alergia

¿Su hijo/a acaba de iniciarse en el consumo de huevo y tras tomar un poco le ha dado una reacción cutánea, le pica la garganta o le duele el estómago? Si su respuesta es afirmativa, seguramente acuda a su pediatra y sea él quien le recomiende la visita a un alergólogo para que determine una posible alergia a este alimento.
Una guía, realizado por expertos de EEUU y publicado en el último 'Pediatrics' , aconseja ahora cómo debe realizarse el diagnóstico.
Los análisis de sangre y las pruebas de punción cutánea (una de las armas más antiguas del arsenal del alergólogo que consiste en colocar extractos de líquidos de alérgenos en el antebrazo del paciente y luego realizar punciones en la piel para comprobar si se produce alguna reacción) se han popularizado en los últimos años como los test que pueden conducir a un correcto diagnóstico de una alergia. Pese a ello, especialistas de EEUU insisten en la escasa utilidad de estas pruebas en ausencia de una historia clínica compatible con una reacción alergica.
Estas pruebas, según reconocen a ELMUNDO.es Robert Wood, del Hospital de Niños Johns Hopkins en Baltimore y Scott Sicherer, del Hospital Mount Sinai de Nueva York (ambos en EEUU), no pueden utilizarse como "los test de oro del diagnóstico de alergia y nunca, además se deben practicar en pacientes asintomáticos. Nuestro trabajo no es un estudio, sino un documento de asesoramiento clínico a los pediatras. El punto principal es que las pruebas sanguíneas y cutáneas deben usarse con cuidado, en su contexto, y no como herramientas independientes para el dictamen final".
Para ambos expertos si se sospecha de una alergia alimentaria, "el estándar de oro diagnóstico continúa siendo la provocación". Consiste en consumir pequeñas dosis del alérgeno sospechoso bajo supervisión del alergólogo.
Opiniones como ésta forman parte del nuevo documento para el diagnóstico de alergias que determina, además, quiénes deberían someterse a los test y quiénes no.
Para Mónica Rodríguez, de la Unidad de alergias del Hospital Universitario Clínico San Carlos de Madrid, el mensaje de los expertos de EEUU es claro. "Las pruebas de alergia son útiles en el diagnóstico de la alergia siempre y cuando se acompañen de una historia clínica compatible".
Esta experta insiste, no obstante, en que pese a que "defiendo la prueba de la provocación como la más adecuada, ésta puede resultar peligrosa en determinados casos, de ahí que sea necesario llevarla acabo sólo cuando esté indicada, bajo las condiciones adecuadas con una supervisión médica y en un servicio con el personal y la dotación adecuados, para poder actuar en caso de anafilaxia (reacción alérgica fuerte)".

-El verdadero significado de una alergia
El informe destaca que "una prueba cutánea positiva o un resultado positivo en la analítica indican únicamente sensibilización, pero no una verdadera alergia", destacan los investigadores. Y ponen como ejemplo que estudios anteriores han encontrado que un 8% de los niños da positivo en los test sanguíneos o en las punciones de piel a los cacahuetes, pero sólo el 1% de ellos tiene síntomas clínicos.
"Una gran variedad de factores desencadenantes pueden ser la causa de las enfermedades alérgicas que se desarrollan en la edad pediátrica entre las que se incluyen el asma, la rinitis alérgica, la dermatitis atópica, la alergia a los alimentos y la anafilaxia", aclara el documento.
Las pruebas comunes de alérgenos específicos de inmunoglobina E (IgE, un tipo de anticuerpo presente sólo en mamíferos que está implicado en las alergias) se llevan a cabo mediante analíticas sanguíneas o inoculaciones en la piel y, "son excelentes para la identificación de un estado de sensibilización a un alérgeno específico, pero un resultado positivo no siempre equivale a una alergia clínica", agregan.
Los científicos determinan también que la decisión de "tratar a un niño debe basarse en la historia clínica y una correcta interpretación del resultado de las pruebas de alergia. En un paciente con historia de reacción y un resultado positivo en los test, cuantos más niveles de anticuerpos presenten, más probabilidad existe de alergia clínica".
Robert Wood y Scott Sicherer destacan que la falta de diagnóstico de una alergia puede ser peligroso e, incluso mortal, pero un diagnóstico incorrecto puede resultar igualmente negativo.
Porque tal y como explica la doctora Rodríguez, "conlleva implíctito alteraciones en la calidad de vida de los pacientes y sus familiares derivados de dietas restrictivas, ansiedad ante la posibilidad de reacciones por contactos inadvertidos, con tomar o tocar mínimas cantidades del alimento".

-Cuándo y a quién hacer las pruebas
El informe determina, además, que los test cutáneos y de sangre pueden y deben ser "utilizados para confirmar si existe una alergia después de observar las reacciones sospechosas. Por ejemplo, los niños con asma moderada o grave deben someterse a pruebas que determinen si existe sensibilización a alérgenos ambientales con lo que se tiene contacto de forma habitual en casa: polen, moho, polvo, animales...".
Se debe vigilar el curso de las "alergias alimentarias establecidas a través de pruebas periódicas. La evolución a largo plazo de los niveles de anticuerpos pueden ayudar a determinar si una persona sigue siendo alérgica o, por el contrario, si está superando la patología".
Es importante también descartar la "existencia de una alergia al veneno de insectos tras una picadura que causa reacciones potencialmente mortales como dificultad para respirar, mareos y urticaria".
En el caso de que un paciente haya presentado reacción alérgica a la administración de una vacuna "se aconseja realizar las pruebas cutáneas de vacunas", detalla el informe.

-...Y cuándo no
No se deben practicar las "pruebas como forma de chequeo general para detectar alergias en niños asintomáticos. Tampoco en los menores sin historia de reacciones alérgicas a alimentos específicos. En este caso, no agregan valor para el diagnóstico".
Y recuerdan que para las alergias a los medicamentos, en general, los "análisis de sangre y las pruebas cutáneas no detectan los anticuerpos específicos".
Como último consejo recomiendan a los padres ante la sospecha de una reacción alérgica: "Llevar al niño a un alergólogo que determinará qué pruebas son necesarias y si existe o no necesidad de sometele a una prueba de provocación para llegar al diagnóstico definitivo".

**Publicado en "EL MUNDO"

Gene identified in increasing pancreatic cancer risk

Mutations in the ATM gene may increase the hereditary risk for pancreatic cancer, according to data published in Cancer Discovery, the newest journal of the American Association for Cancer Research. Pancreatic cancer is one of the most morbid cancers, with less than 5 percent of those diagnosed with the disease surviving to five years. Approximately 10 percent of patients come from families with multiple cases of pancreatic cancer.
"There was significant reason to believe this clustering was due to genetics, but we had not, to this point, been able to find the causative genes that explained the cluster of pancreatic cancer for a majority of these families," said lead author Alison Klein, Ph.D., associate professor of oncology at the Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins and director of the National Familial Pancreas Tumor Registry.
Klein and colleagues used next-generation sequencing, including whole genome and whole exome analyses, and identified ATM gene mutations in two kindreds with familial pancreatic cancer.
When these initial findings were examined in a large series for patients, ATM mutations were present in four of 166 subjects with pancreatic cancer but were absent in 190 spousal control subsets.
Klein said that knowledge of the presence of the ATM gene could lead to better screening for pancreatic cancer, the fourth most common cause of cancer-related death. However, there are currently no recommended screening tests.
Many doctors use endoscopy as a screening tool for pancreatic cancer, but researchers are still evaluating this technique in clinical trials.

**Source: American Association for Cancer Research

Van Andel Research Institute findings provide more complete picture of kidney cancer

Two recent studies by Van Andel Research Institute scientists are providing a foundation for a more complete understanding of distinct kidney cancer subtypes, which could pave the way for better treatments. In a study published in Cancer Cell led by Kyle Furge, Ph.D. and Aikseng Ooi, Ph.D., researchers provide a more complete understanding of the biology of Type 2 papillary renal cell carcinoma (PRCC2), an aggressive type of kidney cancer with no effective treatment, which lays the foundation for the development of effective treatment strategies.
Despite obvious morphological, genetic, and clinical differences, hereditary PRCC2 is thought to share similar pathway deregulation due to genetic mutation with its counterpart, clear cell renal cell carcinoma (CCRCC), a subtype that accounts for 75% of all kidney cancers and that, unlike PRCC2, responds favorably to drugs targeting vascular endothelial growth factor (VEGF), a signal protein produced by cells that stimulate blood vessel formation.
The study, which included international collaboration with researchers from the National Cancer Centre Singapore, Génétique Oncologique EPFE-INSERM U753 and Faculté de Médecine Paris-Sud, Le Kremlin-Bicêtre and Institut de Cancérologie Gustave Roussy, Michigan State University, Northwestern Memorial Hospital, Cleveland Clinic, Singapore General Hospital, and The Wistar Institute, identified deregulation of the KEAP1-NRF2 signaling pathway as a factor that distinguishes PRCC2 from CCRCC, but links both hereditary and sporadic PRCC2.
In another study published in Cancer Research, led by Yan Ding, Ph.D., and Bin Tean Teh, Ph.D. and carried out in collaboration with the National Cancer Centre Singapore, researchers integrated gene expression profiling and RNAi screening data to identify genes involved in CCRCC development and progression.
In recent years, several molecularly targeted therapies such as sunitinib, sorafenib, and pazopanib, which target the receptor tyrosine kinases of VEGF have been approved for CCRCC. Although these therapies significantly extend overall survival, nearly all patients with advanced CCRCC eventually succumb to the disease.
Gene set enrichment analysis indicated that cell-cycle-related genes, in particular PLK1, were associated with disease aggressiveness. Further, the association of PLK1 in both disease aggression and in vitro growth prompted researchers to examine the effects of a small-molecule inhibitor in CCRCC cell lines. Their findings highlight PLK1 as a promising potential therapeutic target for CCRCC.

*Source: Van Andel Research Institute

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