Identifican 214 neurotóxicos que afectan al desarrollo neuronal de niños y adolescentes

30 10 2014

Los investigadores han identificado 214 neurotóxicos que tienen consecuencias negativas en el desarrollo cerebral de niños y adolescentes, incluso desde la etapa prenatal. Philipe Grandjean, profesor de la Escuela Médica de Harvard (Estados Unidos), habla de unaepidemia silenciosa”, que supone un gasto anual de 9.300 millones de euros en Europa por la pérdida de capacidad intelectual debido al mercurio, de los cuales 4.500 millones de euros en España.

B·Debate, una iniciativa de Biocat y la Obra Socialla Caixa”, reunió los pasados días 16 eta 17 de octubre a los mejores expertos en epidemiología y neurociencia en CosmoCaixa para discutir sobre las mejores técnicas en neuroimagen a la hora de analizar los efectos de los factores medioambientales en el desarrollo cerebral, desde la etapa prenatal hasta la adolescencia.

Queremos conocer si estos efectos medioambientales, como la polución del aire, la alimentación o los químicos, tienen un efecto sobre el desarrollo cerebral y la conducta de los niños y adolescentes”, resume Jordi Sunyer, líder científico de este B·Debate y codirector del Centro de Investigación en Epidemiología Ambiental (CREAL), centro de investigación ISGlobal.

Los elementos medioambientales afectan al coeficiente intelectual de los niños. Aunque la variación pueda ser pequeña, a nivel poblacional la distribución de esta capacidad cognitiva se desplaza, afectando a los grupos de los extremos. Mientras que el número de niños con problemas de aprendizaje pueden aumentar hasta un 50%, los niños superdotados disminuirían un 57%.

Los expertos han coincidido en la necesidad de incluir las técnicas de neuroimagen a los grandes estudios poblacionales para comprender los patrones normales de funcionamiento y desarrollo neuronal. “Los neurocientíficos de diferentes disciplinas necesitamos identificar la correlación entre los factores medioambiental y de neurodesarrollo”, dice sobre las ventajas de la neuroimagen Jordi Júlvez, coordinador científico de este B·Debate e investigador del CREAL.

 

 

Creal.cat [on-line] Barcelona (ESP): creal.cat, 30 de octubre de 2014 [ref. 17 de octubre de 2014] Interneten eskuragarri dagoen: http://www.creal.cat/es_noticies/349/cientificos-identifican-214-neurotoxicos-que-afectan-al-desarrollo-neuronal-de-ninos-y-adolescentes



New Discovery in Regulating Autoimmune Diseases

27 10 2014

A natural molecule delays disease onset and reverses disease progression

 

Photomicrograph of a demyelinating MS-Lesion. Image from Creative Commons

The main function of the immune system is to protect against diseases and infections. For unknown reasons our immune system attacks healthy cells, tissues and organs in a process called autoimmunity, which can result in diseases such as multiple sclerosis, Type 1 diabetes, lupus or rheumatoid arthritis. There are currently no existing cures for these diseases.

Now, in a new study by researchers at Brigham and Women’s Hospital, a potential treatment may be on the horizon. Researchers found that NAD+, a natural molecule found in living cells, plants and food, protects against autoimmune diseases by altering the immune response and turning “destructive” cells into “protective” cells. The molecule is also able to reverse disease progression by restoring damaged tissue caused by the autoimmunity process.

“Our study is the first to show that NAD+ can tune the immune response and restore tissue integrity by activating stem cells,” said Abdallah ElKhal, HMS instructor in surgery at Brigham and Women’s Division of Transplant Surgery and Transplantation Surgery Research Laboratory and senior study author. “These findings are very novel and may serve for the development of novel therapeutics.”

The study is published online October 7, 2014, in Nature Communications.

The scientists performed preclinical trials using experimental autoimmune encephalomyelitis, a preclinical model for human multiple sclerosis. They showed that NAD+ can block acute or chronic inflammation by regulating how immune cells, called CD4+ T cells, differentiate. Mice receiving CD4+ T cells along with NAD+ present had a significant delayed onset of disease, as well as a less severe form, therefore demonstrating the molecule’s protective properties.

“This is a universal molecule that can potentially treat not only autoimmune diseases but other acute or chronic conditions such as allergy, chronic obstructive pulmonary disease, sepsis and immunodeficiency,” said Stefan G. Tullius, HMS professor of surgery, Brigham and Women’s Hospital’s chief of Transplant Surgery, director of Transplantation Surgery Research and lead study author.

Moreover, the researchers demonstrated that NAD+ can restore tissue integrity which may benefit patients that have advanced tissue damage caused by autoimmune diseases. In terms of next steps, ElKhal notes that the lab is currently testing additional pathways and the clinical potential of NAD+.

“Since this is a natural molecule found in all living cells, including our body, we hope that it will be well-tolerated by patients,” said ElKhal. “Thus, we hope that its potential as a powerful therapeutic agent for the treatment of autoimmune diseases will facilitate its use in future clinical trials.”

The Transplant Surgery Research Laboratory and Dr. ElKhal’s work is supported by the National Institutes of Health and the Carlos Slim Foundation.

 

 

By MARJORIE MONTEMAYOR-QUELLENBERG

 

Hms.harvard.edu [on-line] Cambridge, MA (USA): hms.harvard.edu, 27 de octubre de 2014 [ref. 14 de octubre de 2014] Interneten eskuragarri dagoen: http://hms.harvard.edu/news/new-discovery-regulating-autoimmune-diseases



Nueva Técnica Endoscópica de Cirugía Fetal en Espina Bífida

23 10 2014

Vall d’Hebron opera prenatalmente a fetos afectados de espina bífida con una nueva técnica endoscópica que permite reducir la prematuridad y las secuelas posteriores de la enfermedad

 

Cirujanos pediátricos y obstetras que forman parte del Programa de Cirugía Fetal del Hospital Universitario Vall d’Hebron, y con la colaboración de la Unidad de Espina Bífida, hace tres años que operan con éxito a los fetos diagnosticados de mielomeningocele o espina bífida, un desorden congénito que afecta al sistema nervioso central y que produce parálisis de las extremidades inferiores, con dificultad o incapacidad para andar así como incontinencia de esfínteres, por la lesión progresiva del tejido neural expuesto al líquido amniótico durante la gestación. El tratamiento estándar para estas intervenciones, de una elevada complejidad, es la cirugía fetal abierta. Es necesario abrir el útero de la madre a la mitad de la gestación como si se tratase de una cesárea, exponer la espalda del feto para operar y corregir quirúrgicamente el defecto. Después, hay que volver a cerrar el útero.

Desde hace un año, un equipo multidisciplinario del Hospital con especialistas en cirugía fetal, obstetricia, neurocirugía, ortopedia, anestesia, radiología, neonatología, rehabilitación, urología, enfermería, etc., realiza estas intervenciones por vía fetoscópica; una técnica mínimamente invasiva (cirugía no abierta) que consiste en entrar en el útero de la madre por dos pequeños orificios (sin necesidad de abrirlo) para llegar a la zona lumbar del feto y operar la malformación. Una vez liberada la médula en el defecto del feto, se protege con unos parches biocompatibles que sustituyen las capas que faltan. Después se cierra la zona del defecto con un bioadhesivo sellador que protege la médula espinal del contacto con el líquido amniótico. A medida que el feto va creciendo, la piel acaba sustituyendo el adhesivo y cubriendo el parche. Cuando el niño nace, el defecto, que ha sido protegido, puede estar cerrado y recubierto de piel. Esta técnica innovadora para sellar el defecto del feto fue ideada y desarrollada por el  Grupo de Bioengenieria, Ortopedia y Cirugía Pediátrica de Vall d’Hebron Instituto de Investigación  tras años de experimentación de cirugía en modelos animales.

 

La combinación de estas dos técnicas pioneras —operar por fetoscopia al feto y proteger su médula espinal colocándole un parche especial que permitirá cerrar el defecto aprovechando las ventajas de la cicatrización fetal— ha dado buenos resultados en los 9 casos en que se ha realizado hasta ahora, ya que 6 de ellos han nacido a término (reducción de la prematuridad), se han reducido las complicaciones en la madre así como las secuelas en el feto. Con esta intervención prenatal se evita el deterioro ulterior de los nervios y su función, para conseguir la mejora de la marcha y, Era berean,, parece mejorar la malformación de Chiari II, la hidrocefalia y, beraz,, el riesgo de deterioro mental.

Dos centros más en el mundo realizan estas intervenciones por vía fetoscòpica; pero el Hospital Vall d’Hebron es el único que está desarrollando una técnica experimental (fetoscopia y parche especial sobre el defecto en la médula del feto) que permite operar antes a las pacientes, en la semana 20 de la gestación, y con resultados preliminares positivos.

El próximo paso será validar estos resultados en otros pacientes y contrastarlos a través de un estudio prospectivo comparativo con los resultados conseguidos con la cirugía fetal abierta, juntamente con el Children’s Hospital de Cincinnati, para estandarizar la técnica.

Se trata de un paso más en la consolidación del Programa de Cirugía Fetal del Hospital, gracias a la implementación de técnicas nuevas, la colaboración con proyectos de investigación y la experiencia de sus profesionales.

 

 

La espina bífida es la segunda causa de discapacidad en la infancia

El mielomeningocele más conocido como espina bífida es una malformación congénita muy compleja que afecta al cierre de la columna vertebral, la médula espinal y todos sus nervios que, al estar en contacto con el líquido amniótico durante el embarazo, sufre un deterioro añadido que empeora el nivel de parálisis. Aún hoy, representa la segunda causa de discapacidad física en la infancia y las secuelas más frecuentes son: en el ámbito motor (problemas para caminar), de esfínteres (no control de los esfínteres de la orina y de las heces) y cerebral, hidrocefalia y malformación de Chiari II (acumulación de líquido cefalorraquídeo en el cerebro y herniación del cerebelo). En España esta malformación afecta a 1 de cada 1.000 nacidos vivos.

El tratamiento clásico del mielomeningocele es el cierre postnatal (al poco tiempo de nacer) del defecto, pero el problema es que el daño ya está hecho porque los nervios han quedado deteriorados y ya no funcionan. Horrela, se hace un tratamiento prenatal (antes de nacer, cuando el feto está dentro del útero de la madre), previo diagnóstico por ecografía y resonancia magnética, que consiste en cerrar el defecto tapando la médula para que no esté en contacto con el líquido amniótico y no se estropee. También para evitar la fuga del líquido cefalorraquídeo, que empeora las malformaciones cerebrales.

 

 

La importancia del diagnóstico y el tratamiento prenatal

El diagnóstico de esta patología se realiza mediante ecografía y se suele hacer en la ecografía de la semana 20, que es la de cribado morfológico. Ante una alteración tan severa como ésta, hasta ahora solo podíamos ofrecer la reparación postnatal o la interrupción de la gestación. En cambio, ahora podemos ofrecer un tratamiento prenatal. Es necesario decir, sin embargo, que en estos momentos el tratamiento prenatal mejora mucho el pronóstico de estos casos, pero no consigue todavía una curación al 100%. Esto hace que estos niños y niñas tengan que ser seguidos en la Unidad de Espina Bífida; una unidad multidisciplinaria y sin límite de edad para hacer el control integral del paciente y la rehabilitación que va encaminada tanto a la mejora de la marcha, como la del control de esfínteres. Esta unidad funciona desde hace 30 años y conceptualmente es la única en todo el Estado.

 

 

 

 

 

Vhebron.net [on-line] Barcelona (ESP): vhebron.net, 23 de octubre de 2014 [ref. 08 de octubre de 2014] Interneten eskuragarri dagoen: http://www.vhebron.net/es/actualidades/-/asset_publisher/gCy8/content/vall-d-hebron-opera-prenatalment-els-fetus-afectats-d-espina-bifida-amb-una-nova-tecnica-endoscopica-que-permet-reduir-la-prematuritat-i-les-sequeles-/10165;jsessionid=49EA8D7340D7B482293379CF9BBDD3F0?redirect=http%3A%2F%2Fwww.vhebron.net%2Fes%2Factualidades%3Bjsessionid%3D49EA8D7340D7B482293379CF9BBDD3F0%3Fp_p_id%3D101_INSTANCE_gCy8%26p_p_lifecycle%3D0%26p_p_state%3Dnormal%26p_p_mode%3Dview%26p_p_col_id%3Dcolumn-2%26p_p_col_pos%3D1%26p_p_col_count%3D2



IEEE Predicts Top Technologies for 2022

20 10 2014

Machine learning, computational biology, bioinformatics, nanotechnology and the Internet of things are on IEEE’s list of top technologies for 2022.

Curious about what the technology landscape will look like in 2022? The Institute of Electrical and Electronics Engineers (IEEE), which represents more than 400,000 engineers, has come up with a report that looks to the future and predicts what the hot technologies of 2022 will be.

 

Indeed, nine technologists led by IEEE Computer Society President Dejan Milojicic spent a large part of this year pondering this question. The results can be found in the IEEE CS 2022 Report, which looks at 23 future technologies that could change the world by 2022. The report can be found here.

 

These technologies, tied into what we call seamless intelligence, present a view of the future,” said IEEE’s Milojicic, in a statement. “Technology is the enabler. What humanity takes out of it really depends on human society.

 

The following contributed to sections of the report: Mohammed AlQuraishi, Harvard Medical School; Angela Burgess, IEEE Computer Society; David Forsyth, Cornell University; Hiroyasu Iwata, Waseda University; Rick McGeer, Communications and Design Group, SAP America; and John Walz, retired from Lucent/AT&T.

 

IEEE said the intent of the report is to predict the future disruptive technologies, aid researchers in understanding the future impact of various technologies and help laymen understand where technology is evolving.

 

Some of the predictions include that multicore will allow users to recharge their smartphones only once a month. The Internet of things will enable people to dress in clothes that monitor all their activities. Nanotechnology will enable lives to be saved by digestible cameras and machines made from particles 50,000 times as small as a human hair. And with the exponential growth of big data there will be increasing concerns about balancing convenience and privacy.

 

The report also recognizes the importance of quantum computing and indicates that universal memory replacements for DRAM will cause a tectonic shift in architectures and software. In addition, 3D printing will create a revolution in fabrication, with many opportunities to produce designs that would have been prohibitively expensive, the study showed.

 

According to the report, machine learning will play an increasingly important role in the lives of peoplewhether it is ranking search results, recommending products or building better models of the environment. And medical robotics will lead to new lifesaving innovations, from autonomous delivery of hospital supplies to telemedicine and advanced prostheses.

 

 

Bien bitartean, with energy consumption increasing along with the world’s population, electric cars, LEDs, smart grids, smart cities, dark silicon, new battery technology, and new ways of cooling data centers are some areas where advances in sustainability are expected. Silicon photonics will address bandwidth, latency and energy challenges, and developments at all levels of the network stack will continue to drive research and the Internet economy, the report said. And in the area of software-defined networks, OpenFlow and SDN will make networks more secure, transparent, flexible and functional.

 

The Open Intellectual Property movement, according to the report, will influence everything from academic publishing and educational models to software, standards, and programming languages. Massively Online Open Courses (MOOCs) also threaten to change the role of faculty, students, and teaching assistants as more institutions embrace the new learning platforms.

 

The 2022 Report covers security, cross-cutting issues, open intellectual prop­erty movement, sustainability, massively online open courses, quantum computing, device and nanotechnology, 3D integrated circuits, multicore, pho­tonics, universal memory, networking and interconnectivity, software-defined networks, high-performance computing, cloud computing, the Internet of things, natural user interfac­es, 3D printing, big data and analytics, machine learning and intelligent systems, computer vision and pattern recognition, life sciences, computational biology and bioinformatics, and robotics for medical care.

 

The report’s authors include Hasan Alkhatib of SSN Services LLC; Paolo Faraboschi of HP Labs, Spain; Eita Frachtenberg of Facebook; Hironori Kasahara of Waseda University; Danny Lange of Microsoft; Phil Laplante of Pennsylvania State University; Arif Merchant of Google; Dejan Milojicic of HP Labs, Palo Alto, and Karsten Schwan of Georgia Tech.

By Darryl K. Taft

 

Eweek.com [on-line] Foster City, CA (USA): eweek.com, 20 de octubre de 2014 [ref. 02 Iraila 2014] Interneten eskuragarri dagoen: http://www.eweek.com/innovation/ieee-predicts-top-technologies-for-2022.html



¿Es posible un Test Diagnóstico del Síndrome del Intestino Irritable?

16 10 2014

Un equipo de investigadores del Vall d’Hebron Institut de Recerca (VHIR), dirigido por la Dra. María Vicario y el Dr. Javier Santos, ha descubierto que los pacientes con síndrome de intestino irritable (SII) y diarrea tienen más actividad inmunitaria en su intestino delgado que las personas sin esta enfermedad. Los resultados del estudio han sido publicados recientemente en la revista Gut y destacados en Nature Reviews, Gastroenterology and Hepatology.

 

De izquierda a derecha: Bruno Rodiño, César Sevillano, Maria Vicario, Javier Santos, Ana Gonzalez, Eloisa Salvo

Sorprendentemente, hemos detectado que los pacientes con esta enfermedad tienen más células productoras de anticuerpos en su yeyuno que las personas sanas, explica la Dra. Vicario. La mayoría de estos anticuerpos son inmunoglobulinas del tipo lgG, que son más eficaces que otros tipos de anticuerpos, y se producen cuando algún antígeno estimula a las células productoras.

 

Para detectar la presencia de los anticuerpos en el intestino, los investigadores realizaron un análisis de expresión de genes que reveló alteraciones a nivel molecular y celular que no se habían descrito antes y que están asociadas a la gravedad de la sintomatología. Hemos descubierto que cuanto más activadas tienen los pacientes las defensas de su intestino, más síntomas sufren, destaca la Dra. Vicario. Los principales síntomas del SII son dolor o incomodidad en la parte inferior del abdomen y modificaciones en la forma o en la frecuencia de las deposiciones.

 

En la actualidad, el diagnóstico del SII se establece únicamente por criterios clínicos y tras la exclusión de otras enfermedades. No existen biomarcadores fiables y por ello, el Dr. Santos insiste en que los resultados de este estudio abren la puerta al diseño de una prueba que permita diagnosticar la enfermedad, mediante la detección de la actividad inmunitaria en el intestino de los pacientes. La elevada actividad inmunitaria solo se detecta en el yeyuno de los pacientes, y no en su sangre, por lo que se trata de un fenómeno local que explica porqué los análisis rutinarios de los pacientes suelen salir absolutamente normales.

 

Vhir.org [on-line] Barcelona (ESP): vhir.org, 16 de octubre de 2014 [ref. 01 de octubre de 2014] Interneten eskuragarri dagoen: http://www.vhir.org/salapremsa/mitjans/mitjans_detall.asp?any=2014&num=199&mv1=5&mv2=1&Idioma=es&titol=Las+personas+con+s%EDndrome+del+



ADHD brain study finds slower development of key connections

13 10 2014

Slow to mature, quick to distract: ADHD brain study finds slower development of key connections.

Brain networks to handle internal & external tasks mature more slowly in ADHD.

A peek inside the brains of more than 750 children and teens reveals a key difference in brain architecture between those with attention deficit hyperactivity disorder and those without.

 

The new research may help lead to the development of a ‘neuromarker’ — a way to use brain imaging to improve diagnosis and treatment of ADHD.

Kids and teens with ADHD, a new study finds, lag behind others of the same age in how quickly their brains form connections within, and between, key brain networks.

The result: less-mature connections between a brain network that controls internally-directed thought (such as daydreaming) and networks that allow a person to focus on externally-directed tasks. That lag in connection development may help explain why people with ADHD get easily distracted or struggle to stay focused.

What’s more, the new findings, and the methods used to make them, may one day allow doctors to use brain scans to diagnose ADHDand track how well someone responds to treatment. This kind of neuroimaging “biomarker” doesn’t yet exist for ADHD, or any psychiatric condition for that matter.

The new findings come from a team in the University of Michigan Medical School’s Department of Psychiatry. They used highly advanced computing techniques to analyze a large pool of detailed brain scans that were publicly shared for scientists to study. Their results are published in the Proceedings of the National Academy of Sciences.

Lead author Chandra Sripada, M.D., Ph.D., and colleagues looked at the brain scans of 275 kids and teens with ADHD, and 481others without it, using “connectomic” methods that can map interconnectivity between networks in the brain.

The scans, made using function magnetic resonance imaging (fMRI) scanners, show brain activity during a resting state. This allows researchers to see how a number of different brain networks, each specialized for certain types of functions, were “talking” within and amongst themselves.

The researchers found lags in development of connection within the internally-focused network, called the default mode network or DMN, and in development of connections between DMN and two networks that process externally-focused tasks, often called task-positive networks, or TPNs. They could even see that the lags in connection development with the two task-related networksthe frontoparietal and ventral attention networks  were located primarily in two specific areas of the brain.

 

The new findings mesh well with what other researchers have found by examining the physical structure of the brains of people with and without ADHD in other ways.

Such research has already shown alterations in regions within DMN and TPNs. So, the new findings build on that understanding and add to it.

The findings are also relevant to thinking about the longitudinal course of ADHD from childhood to adulthood. For instance, some children and teens “grow out” of the disorder, while for others the disorder persists throughout adulthood. Future studies of brain network maturation in ADHD could shed light into the neural basis for this difference.

“We and others are interested in understanding the neural mechanisms of ADHD in hopes that we can contribute to better diagnosis and treatment,” says Sripada, an assistant professor and psychiatrist who holds a joint appointment in the U-M Philosophy department and is a member of the U-M Center for Computational Medicine and Bioinformatics. “But without the database of fMRI images, and the spirit of collaboration that allowed them to be compiled and shared, we would never have reached this point.”

Sripada explains that in the last decade, functional medical imaging has revealed that the human brain is functionally organized into large-scale connectivity networks. These networks, and the connections between them, mature throughout early childhood all the way to young adulthood. “It is particularly noteworthy that the networks we found to have lagging maturation in ADHD are linked to the very behaviors that are the symptoms of ADHD,” he says.

Studying the vast array of connections in the brain, a field called connectomics, requires scientists to be able to parse through not just the one-to-one communications between two specific brain regions, but the patterns of communication among thousands of nodes within the brain. This requires major computing power and access to massive amounts of data – which makes the open sharing of fMRI images so important.

“The results of this study set the stage for the next phase of this research, which is to examine individual components of the networks that have the maturational lag,” he says. “This study provides a coarse-grained understanding, and now we want to examine this phenomenon in a more fine-grained way that might lead us to a true biological marker, or neuromarker, for ADHD.”

Sripada also notes that connectomics could be used to examine other disorders with roots in brain connectivity – including autism, which some evidence has suggested stems from over-maturation of some brain networks, and schizophrenia, which may arise from abnormal connections. Pooling more fMRI data from people with these conditions, and depression, anxiety, bipolar disorder and more could boost connectomics studies in those fields.

 

Volunteers needed for research:

To develop such a neuromarker, Sripada has embarked on follow-up research. One study is enrolling children between the ages of 7 and 17 who have ADHD and a comparison group of those without it; information is at http://umhealth.me/adhdchild. Another study is enrolling adults between the ages of 18 and 35 who have ADHD and a comparison group of those without it; information is at http://umhealth.me/adhdadult. Of note, fMRI scans do not expose a person to radiation. Anyone interested in these studies can email Psych-study@med.umich.edu or call (734) 232-0353; for the study of children, parents should make the contact and consent to research on behalf of their children.

Besides Sripada, the study’s authors are Psychiatry computer specialists Daniel Kessler and Mike Angstadt. Kessler, a graduate of U-M with a degree in neuroscience and statistics, helped develop the key connectomic methods used in the study and plans to pursue this research further in a graduate program starting in 2015. The research was funded by a National Institutes of Health grant (AA020297), a UMCCMB pilot grant, and the John Templeton Foundation. It used fMRI scans from the ADHD-200 and ABIDE projects.

Reference: www.pnas.org/cgi/doi/10.1073/pnas.1407787111

 

By ANN ARBOR

 

 

Uofmhealth.org [on-line] Ann Arbor, MI (USA): uofmhealth.org, 13 de octubre de 2014 [ref. 15 Iraila 2014] Interneten eskuragarri dagoen: http://www.uofmhealth.org/news/archive/201409/slow-mature-quick-distract-adhd-brain-study-finds-slower



Why live vaccines may be most effective for preventing Salmonella infections

9 10 2014

Vaccines against Salmonella that use a live, but weakened, form of the bacteria are more effective than those that use only dead fragments because of the particular way in which they stimulate the immune system, according to research from the University of Cambridge published today.

 

The BBSRC-funded researchers used a new technique that they have developed where several populations of bacteria, each of which has been individually tagged with a unique DNA sequence, are administered to the same host (in this case, a mouse). This allows the researchers to track how each bacterial population replicates and spreads between organs or is killed by the immune system. Combined with mathematical modelling, this provides a powerful tool to study infections within the host. The findings are published today in the journal PLOS Pathogens

 

“We effectively ‘barcode’ the bacteria so that we can see where in the body they go and how they fare against the immune system,” explains Dr Pietro Mastroeni from the Department of Veterinary Medicine at the University of Cambridge, who led the study. “This has provided us with some important insights into why some vaccines are more effective than others.”

 

The multidisciplinary research team led by Dr Mastroeni used the new technique to look at the effectiveness of vaccines against infection by the bacterium Salmonella enterica, which causes diseases including typhoid fever, non-typhoidal septicaemia and gastroenteritis in humans and animals world-wide. Current measures to control S. enterica infections are limited and the emergence of multi-drug resistant strains has reduced the usefulness of many antibiotics. Vaccination remains the most feasible means to counteract S. enterica infections.

 

There are two main classes of vaccine: live attenuated vaccines and non-living vaccines. Live attenuated vaccines use a weakened form of the bacteria or virus to stimulate an immune response – however, there are some concerns that the weakened pathogen may become more virulent when used in patients with compromised immune systems, for example people infected with HIV, malaria or TB. Non-living vaccines, on the other hand, are safer as they usually use inactive bacteria or viruses, or their fragments – but these vaccines are often less effective. Both vaccines work by stimulating the immune system to recognise a particular bacterium or virus and initiate the fight back in the event of future infection.

 

Using their new technique, Dr Mastroeni and colleagues showed that live Salmonella vaccines enhance the ability of the immune system to prevent the bacteria from replicating and spreading to other organs. They can also prevent the spread of the bacteria into the bloodstream, which causes a condition known as bacteraemia, a major killer of children in Africa.

 

They also found that the antibody response induced by live vaccines enhances the ability of immune cells known as phagocytes to kill bacteria in the very early stages of infection, but that a further type of immune cell known as the T-cell – again stimulated by the live vaccine – is subsequently necessary for control and clearance of the bacteria from the blood and tissues. The killed vaccine, whilst able to boost the phagocyte response via the production of antibodies, did not stimulate a protective form of T-cell immunity and was unable to prevent the subsequent bacterial growth in infected organs or the development of bacteraemia, and was unable to control the spread of the bacteria in the body.

 

Dr Chris Coward, first author on the study, says: “We have used a collaboration between experimental science and mathematical modelling to examine how vaccines help the immune system control infection. We found that, for Salmonella infections, the immune response induced by a killed vaccine initially kills a proportion of the invading bacteria but the surviving bacteria then replicate resulting in disease. The live vaccine appears superior because it induces a response that both kills the bacteria and restrains their growth, leading to elimination of the infection.

 

Dr Mastroeni adds: “There is a big push towards the use of non-living vaccines, which are safer, particularly in people with compromised immune systems – and many of the infections such as Salmonella are more prevalent and dangerous in countries blighted by diseases such as HIV, malaria and TB. But our research shows that non-living vaccines against Salmonella may be of limited use only and are not as effective as live vaccines. Therefore more efforts are needed to improve the formulation and delivery of non-living vaccines if these are to be broadly and effectively used to combat systemic bacterial infections. We have used Salmonella infections as a model, but our research approaches can be extended to many pathogens of humans and domestic animals.”

 

The research was carried out Dr Mastroeni, Dr Coward and colleagues Dr Andrew Grant, Dr Oliver Restif, Dr Richard Dybowski and Professor Duncan Maskell. It was funded by the Biotechnology and Biological Sciences Research Council, which has recently awarded Dr Mastroeni funding  to extend this research to the study of how antibiotics work. The new research aims to optimise treatments and reduce the appearance of antibiotic resistance.

 

Professor Melanie Welham, BBSRC’s Science Director, said: “To protect our health and the health of animals we rely on, such as livestock, effective vaccines are needed against disease. This new technique provides unique insights that will help us compare vaccines produced in different ways to ensure the best disease prevention strategies.

 

Reference

Coward, C et al. The Effects of Vaccination and Immunity on Bacterial Infection Dynamics In Vivo. PLOS Pathogens; 18 Sept 2014

 

 

Cam.ac.uk [on-line] Cambridge (UK): cam.ac.uk, 09 de octubre de 2014 [ref. 18 Iraila 2014] Interneten eskuragarri dagoen: http://www.cam.ac.uk/research/news/why-live-vaccines-may-be-most-effective-for-preventing-salmonella-infections



Individual’s unique microbial ‘fingerprint’ drastically affects home environment

6 10 2014

A person’s home is their castle, and they populate it with their own subjects: millions and millions of bacteria.

 

A recent study investigated the complex interplay between the teeming communities of microbes that are unique to each person and the bacteria found in their homes. Courtesy of Argonne National Laboratory

A study published last week in Science provides a detailed analysis of the microbes that live in houses and apartments. The study was conducted by researchers from the U.S. Department of Energy’s Argonne National Laboratory and the University of Chicago.

 

The results shed light on the complicated interaction between humans and the microbes that live on and around us. Mounting evidence suggests that these microscopic, teeming communities play a role in human health and disease treatment and transmission.

 

“We know that certain bacteria can make it easier for mice to put on weight, for example, and that others influence brain development in young mice,” said Argonne microbiologist Jack Gilbert, who led the study. “We want to know where these bacteria come from, and as people spend more and more time indoors, we wanted to map out the microbes that live in our homes and the likelihood that they will settle on us.

 

“They are essential for us to understand our health in the 21st century,” he said.

 

The Home Microbiome Project followed seven families, which included eighteen people, three dogs and one cat, over the course of six weeks. The participants in the study swabbed their hands, feet and noses daily to collect a sample of the microbial populations living in and on them. They also sampled surfaces in the house, including doorknobs, light switches, floors and countertops.

 

Then the samples came to Argonne, where researchers performed DNA analyses to characterize the different species of microbes in each sample.

 

“We wanted to know how much people affected the microbial community on a house’s surfaces and on each other,” Gilbert said.

 

They found that people substantially affected the microbial communities in a house—when three of the families moved, it took less than a day for the new house to look just like the old one, microbially speaking.

 

Regular physical contact between individuals also mattered—in one home where two of the three occupants were in a relationship with one another, the couple shared many more microbes. Married couples and their young children also shared most of their microbial community.

 

Within a household, hands were the most likely to have similar microbes, while noses showed more individual variation.

 

Adding pets changed the makeup as well, Gilbert said—they found more plant and soil bacteria in houses with indoor-outdoor dogs or cats.

 

In at least one case, the researchers tracked a potentially pathogenic strain of bacteria called Enterobacter, which first appeared on one person’s hands, then the kitchen counter and then another person’s hands.

 

“This doesn’t mean that the countertop was definitely the mode of transmission between the two humans, but it’s certainly a smoking gun,” Gilbert said.

 

“It’s also quite possible that we are routinely exposed to harmful bacteria—living on us and in our environment—but it only causes disease when our immune systems are otherwise disrupted.”

 

Home microbiome studies also could potentially serve as a forensic tool, Gilbert said. Given an unidentified sample from a floor in this study, he said, “we could easily predict which family it came from.”

 

The research also suggests that when a person (and their microbes) leaves a house, the microbial community shifts noticeably in a matter of days.

“You could theoretically predict whether a person has lived in this location, and how recently, with very good accuracy,” he said.

 

Researchers used Argonne’s Magellan cloud computing system to analyze the data; additional support came from the University of Chicago Research Computing Center.

 

The study was funded by the Alfred P. Sloan Foundation. Additional funding also came from the National Institutes of Health, the Environmental Protection Agency and the National Science Foundation.

 

Other Argonne researchers on the study included Argonne computational biologist Peter Larsen, postdoctoral researchers Daniel Smith, Kim Handley and Nicole Scott, and contractors Sarah Owens and Jarrad Hampton-Marcell. UChicago graduate students Sean Gibbons and Simon Lax contributed to the paper, as well as collaborators from Washington University in St. Louis and the University of Colorado at Boulder.

 

 

 

News.uchicago.edu [on-line] Chicago, IL (USA): news.uchicago.edu, 06 de octubre de 2014 [ref. 02 Iraila 2014] Interneten eskuragarri dagoen: http://news.uchicago.edu/article/2014/09/02/individuals-microbial-fingerprint-affects-home-environment-study-finds



Implante óseo en amputados femorales

2 10 2014

Se comercializa el implante creado en el Hospital de Mataró que mejora las condiciones de vida de los amputados femorales.

El dispositivo facilita que las personas amputadas tengan más autonomía y puedan hacer vida fuera de casa, ya que pueden tener la prótesis más tiempo, se cansan menos cuando caminan y no sufren tanto dolor.

Con el nuevo implante, una persona a quien se le ha amputado la pierna a la altura de fémur puede recorrer mucha más distancia en dos minutos que antes -122,5 metros con implante, 98,4 metros sin- y lo puede hacer más rápidamente. Concretamente, si la media de la marcha de un paciente amputado sin el implante es de 49,2 metros por minuto, con este dispositivo puede llegar a los 61,3.

 

Más horas con prótesis y menos dolor

Las personas que llevan el implante también pueden llevar la prótesis durante más tiempo, hasta las 13 horas: la media en los amputados femorales es de 10 horas. A pesar del aumento del tiempo, el dolor es inferior al que se sentiría si no se llevara. El pacientes incluidos en el estudio para probar el implante femoral calificaron el dolor que sentían habitualmente en torno al 3 sobre 10, una puntuación que con el implante se reducía al 0,4.

 

Buenos resultados

El implante ha conseguido el marcador CE, que autoriza su comercialización, a raíz de la realización de un ensayo clínico, todavía abierto, realizado en el Servicio de Rehabilitación del Hospital de Mataró-que es quien ha diseñado el implante con la colaboración del Servicio de Cirugía Vascular y el Servicio de Traumatología. En el estudio participan una treintena de pacientes del Hospital de Mataró, del Hospital La Fe de Valencia y del Hospital Nuestra Señora de la Candelaria de Tenerife, con edades comprendidas entre los 30 y los 87 años. La fabricación del implante lo ha realizado la empresa valenciana TEQUIR SL.

 

Ensayo clínico en dos fases

La primera fase del ensayo ha consistido en la colocación del dispositivo, que se implanta dentro del hueso y permite apoyar el peso de la pierna amputada en el encaje de la prótesis. El paciente, una vez dado de alta al cabo de dos días, está 14 meses en seguimiento y asiste a varias sesiones de rehabilitación.

En una segunda fase, que comenzará dentro de unos meses, se realizará la colocación externa, sin necesidad de ingreso, de un segundo dispositivo, también diseñado por el equipo de Rehabilitación del Hospital de Mataró. El objetivo de este segundo dispositivo es conectarse directamente a la prótesis sin necesidad de encaje, que es lo que causa la mayor parte de las molestias y las llagas en los amputados.

 

 

Csdm.es [on-line] Mataró (ESP): csdm.es, 02 de octubre de 2014 [ref. 10 de julio de 2014] Interneten eskuragarri dagoen: http://www.csdm.es/