In Recognizing Faces, the Whole Is Not Greater Than the Sum of Its Parts

How do we recognize a face? To date, most research has answered "holistically": We look at all the features -- eyes, nose, mouth -- simultaneously and, perceiving the relationships among them, gain an advantage over taking in each feature individually. Now a new study overturns this theory. The researchers -- Jason M. Gold and Patrick J. Mundy of the Indiana University and Bosco S. Tjan of the University of California Los Angeles -- found that people's performance in recognizing a whole face is no better than their performance with each individual feature shown alone. "Surprisingly, the whole was not greater than the sum of its parts," says Gold. The findings appear in the journal Psychological Science, which is published by the Association for Psychological Science.
To predict each participant's best possible performance in putting together the individual features, the investigators used a theoretical model called an "optimal Bayesian integrator" (OBI). The OBI measures someone's success in perceiving a series of sources of information -- in this case, facial features -- and combines them as if they were using the sources together just as they would when perceiving them one by one. Their score recognizing the combination of features (the whole face) should equal the sum of the individual-feature scores. If the whole-face performance exceeds this sum, it implies that the relationships among the features enhanced the information processing -- that is, "holistic" facial recognition exists.
In the first experiment participants were shown fuzzy images of three male and three female faces. Then either one feature -- a left or right eye, nose, or mouth -- or all four in proper face-like relationships appeared on the screen. That image would disappear and, if they saw an eye, all six eyes would appear; if a whole face, six whole faces. The participants clicked on the feature or face they'd just seen. In a second experiment, the whole-face images were superimposed on face-shaped ovals -- in case such context helps holistic recognition, as is often claimed. In both experiments, participants' performance with the whole faces was no better than with the isolated features -- and no better than the OBI -- indicating that the facial features were not processed holistically when shown in combination.
"The OBI offers a clearly defined mathematical framework for studying what historically has been a rather loosely defined set of concepts," says Gold.
The findings may offer promise in understanding the cognitive disorder prosopagnosia, the inability to recognize faces, and could also help in constructing better face-recognition software for security. But the real value, says Gold, is in basic research. "If you want to understand the complexities of the human mind, then understanding the basic processes that underlie how we perceive patterns and objects is an important part of that puzzle."

**Published in "SCIENCE DAILY"

La circuncisión podría proteger contra el cáncer de próstata según un estudio observacional

La circuncisión puede proteger a los varones de padecer ciertas enfermedades de transmisión sexual. Estas infecciones podrían estar detrás de ciertos casos de cáncer de próstata; ergo... ¿los varones circuncidados están más protegidos contra este tipo tumor? Un grupo de investigadores estadounidenses se planteó esta hipótesis y la respuesta es afirmativa.
El papel de ciertos virus en algunos casos de cáncer está más que establecido. Es así, por ejemplo, para el papilomavirus humano que desencadena el cáncer de cuello de útero en las mujeres. En el caso de los varones, ciertas evidencias sugieren que las infecciones de transmisión sexual son capaces de ocasionar una inflamación crónica de los tejidos, es decir, un entorno favorable para que se desarrollen las células tumorales.
El prepucio (que recubre el glande) es un tipo de tejido rico en células inmunes, más vulnerables a las infecciones. Además, es fácil que se produzcan pequeños desgarros a través de los cuales ciertos virus pueden acceder al organismo. De hecho, desde 2007, la Organización Mundial de la Salud (OMS) recomienda la circuncisión como método para prevenir nuevos casos de VIH, después de que varios estudios hayan demostrado su utilidad. Sin embargo, su papel en la prevención del cáncer prostático no se había abordado hasta ahora.

-Antes del debut sexual
Por eso, el equipo dirigido por Jonathan Wright, del centro de cáncer Fred Hutchinson de Washington (EEUU), llevó a cabo un amplio análisis para comprobar si la circuncisión otorga a los varones cierta protección antitumoral (precisamente porque reduce su incidencia de infecciones). Sus resultados se publican en la revista 'Cancer'.
Para su estudio analizaron a 3.399 varones; cerca de la mitad de ellos sanos y, el resto, diagnosticados con cáncer de próstata. Según su análisis, aquellos que habían sido circuncidados antes de su primera relación sexual tenían un 15% menos de riesgo de cáncer que los varones que mantenían su prepucio intacto.
Esta protección derivada de la circuncisión se mantuvo tanto para los casos de cáncer de próstata más benignos (12% menos de riesgo) como para los tumores más agresivos (18% de reducción). Sin embargo, no fue así para quienes habían sido circuncidados después de su debut sexual. "Creemos que esta cirugía resulta protectora en aquellos casos de cáncer en los que existe un mecanismo infeccioso a través de la vía sexual", resume Wright a ELMUNDO.es, "de manera que después de la primera relación sexual, la circuncisión no tendría este efecto puesto que el contacto con el agente infeccioso ya se habría producido".
Jesús García Mata, miembro de la Sociedad Española de Oncología Médica (SEOM), considera que el estudio es interesante, "aunque habrá que seguir estudiando el papel de las infecciones genitourinarias en el cáncer de próstata". Según el jefe del servicio de Oncología del Complejo Hospitalario de Orense, la reducción del 15% de riesgo que se observa en el estudio es importante teniendo en cuenta que el cáncer de próstata es una patología frecuente en varones.
No obstante, Rogelio González Sarmiento, del Centro de Investigación del Cáncer de Salamanca (CIC), es cauto en su interpretación. "Aunque las diferencias son significativas, no queda claro si se pueden atribuir a la circuncisión o a la infección", explica a ELMUNDO.es.
Por otra parte, añade, "dependiendo de los programas de detección precoz, la población que se incluye en este tipo de investigaciones no siempre es homogénea. Además, en estos estudios influyen los hábitos sexuales e higiénicos de las diferentes poblaciones, por lo que estos resultados no son extrapolables". El propio autor es cauto en sus palabras con este periódico: "Son resultados observacionales, podemos sugerir los mecanismos, pero no probar la causalidad".
De hecho, el estudio no aborda en profundidad los mecanismos por los que esta cirugía, que consiste en retirar el prepucio del pene, podría proteger contra el cáncer. "Aunque se trata de un trabajo observacional, los datos sugieren un mecanismo biológico plausible"; de hecho, citan numerosos trabajos en los que se demuestra que algunos virus e infecciones son capaces de generar una respuesta inflamatoria en los tejidos que crea un entorno favorable para las células malignas. Se calcula, por ejemplo, que los virus están detrás del 17% de los diagnósticos.
Por ejemplo, algunos virus son capaces de generar cambios malignos directamente en las células, integrándose en su ADN. En otros casos, "alteran el microambiente de los tejidos, generando daños oxidativos y favoreciendo la proliferación celular que da origen a un tumor", explican.

**Publicado en "EL MUNDO"

New Approach to Treating Type 1 Diabetes? Transforming Gut Cells Into Insulin Factories

A study by Columbia researchers suggests that cells in the patient's intestine could be coaxed into making insulin, circumventing the need for a stem cell transplant. Until now, stem cell transplants have been seen by many researchers as the ideal way to replace cells lost in type I diabetes and to free patients from insulin injections.
The research -- conducted in mice -- was published 11 March 2012 in the journal Nature Genetics.
Type I diabetes is an autoimmune disease that destroys insulin-producing cells in the pancreas. The pancreas cannot replace these cells, so once they are lost, people with type I diabetes must inject themselves with insulin to control their blood glucose. Blood glucose that is too high or too low can be life threatening, and patients must monitor their glucose several times a day.
A longstanding goal of type I diabetes research is to replace lost cells with new cells that release insulin into the bloodstream as needed. Though researchers can make insulin-producing cells in the laboratory from embryonic stem cells, such cells are not yet appropriate for transplant because they do not release insulin appropriately in response to glucose levels. If these cells were introduced into a patient, insulin would be secreted when not needed, potentially causing fatal hypoglycemia.
The study, conducted by Chutima Talchai, PhD, and Domenico Accili, MD, professor of medicine at Columbia University Medical Center, shows that certain progenitor cells in the intestine of mice have the surprising ability to make insulin-producing cells. Dr. Talchai is a postdoctoral fellow in Dr. Accili's lab.
The gastrointestinal progenitor cells are normally responsible for producing a wide range of cells, including cells that produce serotonin, gastric inhibitory peptide, and other hormones secreted into the GI tract and bloodstream.
Drs. Talchai and Accili found that when they turned off a gene known to play a role in cell fate decisions -- Foxo1 -- the progenitor cells also generated insulin-producing cells. More cells were generated when Foxo1 was turned off early in development, but insulin-producing cells were also generated when the gene was turned off after the mice had reached adulthood. "Our results show that it could be possible to regrow insulin-producing cells in the GI tracts of our pediatric and adult patients," Dr. Accili says.
"Nobody would have predicted this result," Dr. Accili adds. "Many things could have happened after we knocked out Foxo1. In the pancreas, when we knock out Foxo1, nothing happens. So why does something happen in the gut? Why don't we get a cell that produces some other hormone? We don't yet know."
Insulin-producing cells in the gut would be hazardous if they did not release insulin in response to blood glucose levels. But the researchers say that the new intestinal cells have glucose-sensing receptors and do exactly that.
The insulin made by the gut cells also was released into the bloodstream, worked as well as normal insulin, and was made in sufficient quantity to nearly normalize blood glucose levels in otherwise diabetic mice.
"All these findings make us think that coaxing a patient's gut to make insulin-producing cells would be a better way to treat diabetes than therapies based on embryonic or iPS stem cells," Dr. Accili says. The location of the cells in the gut may also prevent the diabetes from destroying the new insulin-producing cells, since the gastrointestinal tract is partly protected from attack by the immune system.

**Published in "SCIENCE DAILY"

Según un estudio alemán el ejercicio podría no prevenir el riesgo de caídas en ancianos

Realizar un programa de ejercicio regular podría ayudar a los mayores a moverse mejor, pero no aumentaría necesariamente su estabilidad o les ayudaría a perder el miedo a caerse, según un estudio de la Friedrich-Alexander-Universitat Erlangen-Nurnberg, en Alemania, publicado en Journal of the American Geriatrics Society. Según la coordinadora del estudio, Ellen Freiberger, «no se puede dar por supuesto que si se mejora la actividad física eso se traslade a la dimensión psicológica».
El equipo de Freiberger se propuso comparar diferentes tipos de ejercicio y qué impacto, si tiene alguno, tiene sobre el rendimiento físico, las caídas y el miedo a caer entre los mayores. Para ello, reclutaron a 280 personas mayores de 70 años que todavía vivían independientes en Erlangen, Alemania.
Programa de ejercicios
Entre 2003 y 2006, los participantes fueron divididos en cuatro grupos y seguidos durante dos años. Un grupo no hizo ningún ejercicio, otros tres realizaron ejercicios de fuerza y equilibrio, pero sólo dos de ellos incluyeron ejercicios de resistencia, que los investigadores utilizaron para valorar el estado físico de los participantes o un programa formativo para medir su miedo a las caídas. El régimen final del grupo incluyó elementos de programas formativos diseñados para reducir el miedo a las caídas y ejercicios mentales para mejorar la concentración y la memoria a corto plazo.
Todos los miembros de los grupos de ejercicio que han participado en el estudio asistieron a dos sesiones de una hora semanales durante 16 semanas. Cada sesión tenía menos de 15 participantes. Al final, no hubo diferencias entre los cuatro grupos en las puntuaciones que controlaron las caídas o el miedo a caer, sólo una leve mejora del tiempo que tardaban en caminar seis metros.

*AGENCIAS

Antidepressant Shows Promise as Cancer Treatment

An antidepressant combined with a drug derived from vitamin A could be used to treat a common adult form of leukemia, according to laboratory research led by a team at The Institute of Cancer Research (ICR).

A retinoid called all-trans retinoic acid (ATRA), which is a vitamin A-derivative, is already used successfully to treat a rare sub-type of acute myeloid leukemia (AML) *, however this drug has not been effective for the more common types of AMLs.
Team leader Dr Arthur Zelent and colleagues at the ICR, with principal funding from leukemia & Lymphoma Research, have been working to unlock the potential of retinoids to treat other patients with AML. In a paper recenlty published in Nature Medicine, they show that the key could be an antidepressant called tranylcypromine (TCP).
"Retinoids have already transformed one rare type of fatal leukemia into a curable disease. We've now found a way to harness these powerful drugs to treat far more common types of leukemia," senior author Dr Zelent, from the ICR, said. "Until now, it's been a mystery why the other forms of AML don't respond to this drug. Our study revealed that there was a molecular block that could be reversed with a second drug that is already commonly used as an antidepressant. We think this is a very promising strategy, and if these findings can be replicated in patients the potential benefits are enormous."
ATRA works by encouraging the leukemia cells to mature and die naturally. The team thinks the failure of AML to respond to this drug may be due to genes that ATRA normally targets becoming switched off. In their search for a drug that could be used to reboot the activity of ATRA, the team looked to an emerging area of research called epigenetics. Epigenetic drugs do not target genes directly but instead target whether genes are switched on or off. They discovered that inhibiting an enzyme called LSD1, using TCP, could switch these genes on again and make the cancer cells susceptible to ATRA.
Along with collaborators at the University of Münster in Germany, the team have already started a Phase II clinical trial of the drug combination in acute myeloid leukemia patients.
Co-author Dr Kevin Petrie from the ICR says: "Both the retinoid ATRA and the antidepressant TCP are already available in the UK and off-patent, so these drugs should not be expensive for the health service. AML remains very difficult to treat and sadly is often fatal, with rates of the disease projected to increase significantly as the population ages, so it is particularly pleasing to have identified this new treatment approach. Importantly, we believe these drugs are targeting only the cancer cells and leaving normal healthy cells largely untouched, so we are hopeful that they would have fewer side-effects for patients than standard drugs. We look forward to seeing the results of the clinical trials."
Each year, more than 2,200 people in the UK are diagnosed with acute myeloid leukemia, a type of cancer characterised by the uncontrolled growth of immature white blood cells in the bone marrow.
Professor Chris Bunce, Research Director at leukemia & Lymphoma Research, said: "These results are extremely significant. Current drugs for AML are very aggressive and many older patients have a poor outlook as they cannot tolerate treatment. ATRA has been a major success story in recent years in treating a particular subtype of AML. In finding a way to expand its use, we would have the potential to save thousands of lives a year."

**published in "SCIENCE DAILY"

La cirugía de aumento de los senos es una de las más demandadas por las pacientes, según un estudio

El exceso de peso y el tamaño del pecho son los problemas estéticos que más preocupan a las españolas, según una encuesta que revela que el 61% de las consultas que reciben las clínicas de cirugía y medicina estética son para informarse sobre tratamientos para adelgazar o remodelar la silueta. Así se desprende de un sondeo realizado entre 2.642 mujeres, que desvela que la preocupación por el sobrepeso se ha visto incrementada en los últimos años.
El doctor Fernando Saenger, director médico de Clínica Opción Médica y fundador de Clínica Londres, promotoras de este sondeo, cree que esto puede deberse en parte a los cambios alimenticios derivados de la crisis económica.
La cesta de la compra se ha llenado ahora con alimentos más económicos como féculas, grasas y productos industriales en detrimento de pescados, carnes magras, frutas o verduras. "Hemos descuidado nuestros hábitos", ha matizado el experto.
Por debajo de la inquietud por reducir el volumen corporal, el tamaño y la forma de los pechos ocupan el segundo lugar con un 13,73% del total de las peticiones de información.
De entre las cirugías mamarias, la más solicitada es la de aumento, con un 80%, seguida de la mastopexia, para corregir la ptosis mamaria o caída de los senos, que representa más del 15% de las solicitudes, y la reducción de mamas, mucho menos demandada, con un 3,3%.
La medalla de bronce es para los tratamientos antienvejecimiento, que suponen un 7,5% de las consultas en las clínicas estéticas, siendo el bótox y los rellenos faciales los más populares y demandados.

-«Ganar en seguridad y confianza»
"La sociedad actual nos exige cuidarnos más y preocuparnos más por nuestra imagen. Cuando los pacientes llaman a nuestras consultas para solicitar información, lo que buscan es sentirse bien con su aspecto físico y ganar en confianza y seguridad", ha explicado Saenger.
El especialista ha comentado que la cirugía y la medicina estética han evolucionado mucho durante los últimos años y hoy en día se pueden satisfacer las "necesidades reales" de cada paciente, "logrando cumplir las expectativas e ilusiones depositadas en el procedimiento".
Pese a la crisis económica, los tratamientos medico-estéticos están en auge y suponen más del 35% de las solicitudes de información que reciben los centros médicos dedicados al sector de la estética. "Son una alternativa más económica que cualquier cirugía y, aunque nunca ofrecerán los mismos resultados, son muy eficaces para pequeños retoques", ha sentenciado Saenger.
De hecho, según datos de la Sociedad Española de Medicina Estética (SEME), el pasado año se abrieron en España un 20% más de clínicas de medicina estética. Otros de los tratamientos más demandados son la fotodepilación médica láser y el abordaje terapéutico de varices y arañas vasculares, según los datos de la encuesta.

**Publicado en "VOCENTO"

New transplant method may allow kidney recipients to live life free of anti-rejection medication

New ongoing research published March 7 in the journal Science Translational Medicine suggests organ transplant recipients may not require anti-rejection medication in the future thanks to the power of stem cells, which may prove to be able to be manipulated in mismatched kidney donor and recipient pairs to allow for successful transplantation without immunosuppressive drugs. Northwestern Medicine® and University of Louisville researchers are partnering on a clinical trial to study the use of donor stem cell infusions that have been specially engineered to "trick" the recipients' immune system into thinking the donated organ is part of the patient's natural self, thus gradually eliminating or reducing the need for anti-rejection medication. "The preliminary results from this ongoing study are exciting and may have a major impact on organ transplantation in the future," said Joseph Leventhal, MD, PhD, transplant surgeon at Northwestern Memorial Hospital and associate professor of surgery and director of kidney and pancreas transplantation at Northwestern University Feinberg School of Medicine. "With refinement, this approach may prove to be applicable to the majority of patients receiving the full spectrum of solid organ transplants."
Leventhal authored the study along with Suzanne Ildstad, MD, director of the Institute of Cellular Therapeutics at the University of Louisville. It is the first study of its kind where the donor and recipient do not have to be related and do not have to be immunologically matched. Previous studies involving stem cell transplants for organ recipients have included donors and recipients who are siblings and are immunologically identical, something that only occurs in about 25 percent of sibling pairs.
"Being a transplant recipient is not easy. In order to prevent rejection, current transplant recipients must take multiple pills a day for the rest of their lives. These immunosuppressive medications come with serious side effects with prolonged use including high blood pressure, diabetes, infection, heart disease and cancer, as well as direct damaging effects to the organ transplant," said Ildstad. "This new approach would potentially offer a better quality of life and fewer health risks for transplant recipients."
In a standard kidney transplant, the donor agrees to donate their kidney. In the approach being studied, the individual is asked to donate part of their immune system as well. The process begins about one month before the kidney transplant, when bone marrow stem cells are collected from the blood of the kidney donor using a process called apheresis. The donor cells are then sent to the University of Louisville to be processed, where researchers enrich for "facilitating cells" believed to help transplants succeed. During the same time period, the recipient undergoes pre-transplant "conditioning," which includes radiation and chemotherapy to suppress the bone marrow so the donor's stem cells have more space to grow in the recipient's body.
Once the facilitating cell-enriched stem cell product has been prepared, it is transported back to Northwestern, where the recipient undergoes a kidney transplant. The donor stem cells are then transplanted one day later and prompt stem cells to form in the marrow from which other specialized blood cells, like immune cells, develop. The goal is to create an environment where two bone marrow systems exist and function in one person. Following transplantation, the recipient takes anti-rejection drugs which are decreased over time with the goal to stop a year after the transplant.
"This is something I have worked for my entire life," said Ildstad, who pioneered the approach and is known for her discovery of the "facilitating" cell.
Less than two years after her successful kidney transplant, 47-year-old mother and actress Lindsay Porter of Chicago, is living a life that most transplant recipients dream of -- she is currently free of anti-rejection medications and says at times, she has to remind herself that she had a kidney transplant. "I hear about the challenges recipients have to face with their medications and it is significant. It's almost surreal when I think about it because I feel so healthy and normal." Doctors are hopeful that Porter will not need immunosuppressive drugs long-term, given her progress thus far.
In order to qualify for this type of experimental kidney transplant, the donor and recipient pairs must be blood-type compatible and have a negative cross-match, which means that testing has been done to confirm the recipient does not have antibodies in the blood that would cause rejection of the kidney.
The clinical trial is ongoing. Researchers are also planning a second clinical trial, which would offer similar treatment for subjects who have already undergone a living donor kidney transplant.
Dr. Suzanne Ildstad has equity interest in Regenerex LLC, a collaborating entity on this study. Personnel from Regenerex are involved in the processing of the donor cells and provide guidance regarding development, regulatory and manufacturing issues related to the study.

**Source: Northwestern Memorial Hospital