For men with erectile dysfunction (ED), 65 percent are unable to have an orgasm and 58 percent have problems with ejaculation, according to new research led by physician-scientists at NewYork-Presbyterian Hospital/Weill Cornell Medical Center. The study followed 12,130 men with mild to severe ED and is the largest-ever analysis of orgasmic and ejaculatory dysfunction. Results are published in today's edition of the British Journal of Urology International.
Approximately 30 million American men, or half of all men aged 40 to 70, have trouble achieving or sustaining an erection. "While medications like Viagra or Cialis have been successful in helping many of these men, our research suggests there are other common sexual issues that remain largely unaddressed," says Dr. Darius Paduch, the study's lead author; male sexual medicine specialist at NewYork-Presbyterian Hospital/Weill Cornell Medical Center; and assistant professor of urology and reproductive medicine at Weill Cornell Medical College.
"We must expand the definition of quality of life when it comes to sexual performance," Dr. Paduch adds. "For the last few decades, we have focused on penile rigidity, with erection as a synonym of normal sexual function. However, many patients say that problems with ejaculation -- like decreased force or volume or decreased sensation of orgasm -- are just as critical.
"Despite the frequency of these issues, non-erectile sexual dysfunction is underreported and undertreated due to social stigma and misunderstandings about the physiology of male sexual response and orgasmic dysfunction in particular. For decades it was believed that only women had problems with orgasm; our study shows that orgasmic dysfunction could be as prevalent among men as it is among women."
While severity of dysfunctional ejaculation and orgasm correlated with ED severity, says Dr. Paduch, these issues were still surprisingly common in men with very mild ED: Orgasm dysfunction was reported by 26 percent in this group, and ejaculation dysfunction by 18 percent. "This suggests that non-erectile sexual dysfunction is a regular occurrence even in men without ED."
The study reported factors associated with increased risk of ejaculatory and orgasmic dysfunction which includes commonly prescribed antidepressant medications. Ejaculatory and orgasmic dysfunction can be caused by low testosterone and minor brain injury such as that sustained by motor vehicle accident victims, football players suffering from concussion, or by soldiers with combat-related blast head injuries.
The most common ejaculatory dysfunction is premature ejaculation, but the condition also describes delayed ejaculation, inability to ejaculate, painful ejaculation, retrograde ejaculation, as well as a reduced volume of ejaculate or diminished force of ejaculation. Orgasm dysfunction is defined as absence of an orgasm.
In the current study, Dr. Paduch and Alexander Bolyakov, a research associate at Weill Cornell Medical College, in collaboration with a research team from Eli Lilly and Company, analyzed questionnaires from 28 clinical trials of men with mild to moderate erectile dysfunction from a diverse, international cohort of patients enrolled in clinical trials for tadalafil (Cialis).
The study was supported by an educational grant from Eli Lilly and Company. Dr. Paduch and Bolyakov are paid investigators and/or consultants/advisers/speakers for the study sponsor. Additional co-authors included Dr. Anthony Beardsworth and Steven D. Watts -- both from Eli Lilly.
Going forward, Dr. Paduch and Bolyakov will use uniquely specialized equipment available in their lab at Weill Cornell to measure biological and subjective changes that occur in men during orgasm and ejaculation. They will look at whether testosterone-replacement therapy can help men who suffer from non-erectile sexual dysfunction.
"Sexual satisfaction is known to be linked to the likelihood of orgasm, which in turn affects emotional intimacy and relationship satisfaction. The high prevalence of both orgasmic and ejaculatory dysfunction warrants further clinical and translational research into new treatments to improve sexual health and overall quality of life for hundreds of thousands of affected men and their loved ones," says Dr. Paduch.
**Source: New York- Presbyterian Hospital/Weill Cornell Medical Center/Weill Cornell Medical College
24 August 2011
Scientists develop new approaches to predict the environmental safety of chemicals
Baylor University environmental researchers have proposed in a new study a different approach to predict the environmental safety of chemicals by using data from other similar chemicals. For many chemicals in use every day, scientists do not have enough information to understand all of the effects on the environment and human health. In response to this, the European Union enacted the REACH regulation, which places greater responsibility on industry to manage the risks from chemicals and to provide safety information on the substances. The Registration, Evaluation, Authorisation and Restriction of Chemical Substances (REACH) regulation was enacted in 2006 and requires manufacturers and importers to gather information on the properties of their chemical substances and to register the information in a central database. Regulators say the goal of REACH is to improve the protection of human health and the environment through better and earlier identification of the harmful properties of chemical substances.
In the Baylor study, researchers suggest using data from other chemicals, such as what concentrations can cause toxicity in aquatic organisms to predict the toxicity of another chemical that scientists expect causes toxicity in the same way.
"This study proposes one approach to advance the three R's of sustainability -- reduce, replace, refine -- for studying biological impacts of chemicals in the environment," said study co-author Dr. Bryan Brooks, associate professor of environmental science and biomedical studies and director of environmental health science at Baylor. "Identifying, testing and implementing new approaches to leverage available information to support better environmental decision-making remains a critical need around the world."
Baylor researchers used statistical and mathematical techniques called chemical toxicity distributions to understand the relative potency of two groups of chemicals. They then used these findings to develop environmental safety values, which they hope will help determine the environmental impacts of chemical substances without unnecessary testing on animals.
"The biggest hurdle we face when protecting public health and the environment is the general lack of information," said study co-author Dr. Spencer Williams, a research scientist at Baylor. "The approach we propose should help prioritize the selection of chemicals and organisms for additional safety assessments. Instead of having to test similar chemicals on many organisms over and over again, scientists could estimate safety levels using fewer tests, which could be more efficient without compromising environmental safety."
The study appears online in the journal Environmental Toxicology and Chemistry.
**Source: Baylor University
In the Baylor study, researchers suggest using data from other chemicals, such as what concentrations can cause toxicity in aquatic organisms to predict the toxicity of another chemical that scientists expect causes toxicity in the same way.
"This study proposes one approach to advance the three R's of sustainability -- reduce, replace, refine -- for studying biological impacts of chemicals in the environment," said study co-author Dr. Bryan Brooks, associate professor of environmental science and biomedical studies and director of environmental health science at Baylor. "Identifying, testing and implementing new approaches to leverage available information to support better environmental decision-making remains a critical need around the world."
Baylor researchers used statistical and mathematical techniques called chemical toxicity distributions to understand the relative potency of two groups of chemicals. They then used these findings to develop environmental safety values, which they hope will help determine the environmental impacts of chemical substances without unnecessary testing on animals.
"The biggest hurdle we face when protecting public health and the environment is the general lack of information," said study co-author Dr. Spencer Williams, a research scientist at Baylor. "The approach we propose should help prioritize the selection of chemicals and organisms for additional safety assessments. Instead of having to test similar chemicals on many organisms over and over again, scientists could estimate safety levels using fewer tests, which could be more efficient without compromising environmental safety."
The study appears online in the journal Environmental Toxicology and Chemistry.
**Source: Baylor University
Células madre para desentrañar los misterios del Parkinson
Un grupo de científicos del Reino Unido ha desarrollado neuronas dopaminérgicas a partir de las células de la piel de un paciente con una forma de Parkinson de rápida progresión y un familiar sin este trastorno. Se trata de una vía que ayudará a desentrañar los mecanismos que generan esta patología que, hasta el momento, es una gran desconocida para los expertos.
La enfermedad de Parkison es el más frecuente de los trastornos neurodegenerativos. Se caracteriza por una pérdida progresiva de neuronas productoras de dopamina en la sustancia negra y la aparición de acumulaciones proteicas que se depositan en las neuronas formando estructuras que se denominan cuerpos de Lewy. Los modelos que existen para estudiar este trastorno en animales no son buenos porque no reproducen bien la enfermedad, así que cualquier avance en este sentido supone un paso más para, en un futuro, conocer mejor las causas que están detrás de esta enfermedad.
Sin embargo, con la llegada de las iPS, células de pluripotencialidad inducida, este panorama puede cambiar. Esta tecnología, desarrollada por el científico japonés Shinya Yamanaka, transforma células adultas (de la piel o de otras estructuras) en células madre similares a las embrionarias que luego pueden convertirse en otro tipo de células distintas de las originales. Si este procedimiento se utiliza en personas con enfermedades incurables o patologías raras, es posible investigar directamente sobre sus neuronas, no las de su cerebro sino las que se han producido a partir de una muestra de su piel.
"La tecnología de las iPS tiene el potencial de revolucionar nuestra compresión del Parkinson, porque ofrece la oportunidad de generar y estudiar células afectadas (por este trastorno) directamente de pacientes. Este enfoque ya ha sido utilizado para generar modelos celulares de diferentes trastornos neurológicos: esclerosis lateral amiotrófica, Parkinson esporádico, atrofia muscular espinal y disautonomía familiar", explican los autores del trabajo.
El estudio, realizado por investigadores de universidades de Edimburgo y Londres, utilizó células de la piel de un paciente con un tipo de Parkinson que progresa rápidamente y que puede diagnosticarse a los 30 años. Las personas con esta forma de la enfermedad tienen el doble del número de aquellos genes que producen la proteína, denominada alfa-sinucleina, que es la que se suele depositar en las neuronas.
Ésta no es la primera investigación que emplea las iPS para estudiar el Parkinson, el pasado mes de marzo científicos de la Universidad de Standford (EEUU) publicaron un estudio en el que se había utilizado esta tecnología en otro tipo de Parkinson. Sin embargo, el trabajo que hoy se publica en la revista Nature Communications fija su atención en la forma de rápido progreso.
"Comprender esta forma progresiva del trastorno nos ayudará a entender otros tipos de Parkinson. Al mismo tiempo, al evolucionar rápidamente nos facilita seguir los efectos de los fármacos utilizados para prevenir el daño neuronal por la enfermedad", explica el doctor Michael Devine, del Instituto de Neurología de la University College London.
Por su parte, Kieran Breen, director de Investigación y Desarrollo de la Parkinson's UK (organización que patrocinó el estudio con 300.000 libras), ha señalado que "aunque la mutación genética que conduce a esta forma progresiva de Parkinson es rara, este apasionante estudio tiene el potencial de traernos una gran cantidad de avances en la investigación contra el Parkinson.
La enfermedad de Parkison es el más frecuente de los trastornos neurodegenerativos. Se caracteriza por una pérdida progresiva de neuronas productoras de dopamina en la sustancia negra y la aparición de acumulaciones proteicas que se depositan en las neuronas formando estructuras que se denominan cuerpos de Lewy. Los modelos que existen para estudiar este trastorno en animales no son buenos porque no reproducen bien la enfermedad, así que cualquier avance en este sentido supone un paso más para, en un futuro, conocer mejor las causas que están detrás de esta enfermedad.
Sin embargo, con la llegada de las iPS, células de pluripotencialidad inducida, este panorama puede cambiar. Esta tecnología, desarrollada por el científico japonés Shinya Yamanaka, transforma células adultas (de la piel o de otras estructuras) en células madre similares a las embrionarias que luego pueden convertirse en otro tipo de células distintas de las originales. Si este procedimiento se utiliza en personas con enfermedades incurables o patologías raras, es posible investigar directamente sobre sus neuronas, no las de su cerebro sino las que se han producido a partir de una muestra de su piel.
"La tecnología de las iPS tiene el potencial de revolucionar nuestra compresión del Parkinson, porque ofrece la oportunidad de generar y estudiar células afectadas (por este trastorno) directamente de pacientes. Este enfoque ya ha sido utilizado para generar modelos celulares de diferentes trastornos neurológicos: esclerosis lateral amiotrófica, Parkinson esporádico, atrofia muscular espinal y disautonomía familiar", explican los autores del trabajo.
El estudio, realizado por investigadores de universidades de Edimburgo y Londres, utilizó células de la piel de un paciente con un tipo de Parkinson que progresa rápidamente y que puede diagnosticarse a los 30 años. Las personas con esta forma de la enfermedad tienen el doble del número de aquellos genes que producen la proteína, denominada alfa-sinucleina, que es la que se suele depositar en las neuronas.
Ésta no es la primera investigación que emplea las iPS para estudiar el Parkinson, el pasado mes de marzo científicos de la Universidad de Standford (EEUU) publicaron un estudio en el que se había utilizado esta tecnología en otro tipo de Parkinson. Sin embargo, el trabajo que hoy se publica en la revista Nature Communications fija su atención en la forma de rápido progreso.
"Comprender esta forma progresiva del trastorno nos ayudará a entender otros tipos de Parkinson. Al mismo tiempo, al evolucionar rápidamente nos facilita seguir los efectos de los fármacos utilizados para prevenir el daño neuronal por la enfermedad", explica el doctor Michael Devine, del Instituto de Neurología de la University College London.
Por su parte, Kieran Breen, director de Investigación y Desarrollo de la Parkinson's UK (organización que patrocinó el estudio con 300.000 libras), ha señalado que "aunque la mutación genética que conduce a esta forma progresiva de Parkinson es rara, este apasionante estudio tiene el potencial de traernos una gran cantidad de avances en la investigación contra el Parkinson.
**Publicado en "EL MUNDO"
Células madre para desentrañar los misterios del Parkinson
Un grupo de científicos del Reino Unido ha desarrollado neuronas dopaminérgicas a partir de las células de la piel de un paciente con una forma de Parkinson de rápida progresión y un familiar sin este trastorno. Se trata de una vía que ayudará a desentrañar los mecanismos que generan esta patología que, hasta el momento, es una gran desconocida para los expertos.
La enfermedad de Parkison es el más frecuente de los trastornos neurodegenerativos. Se caracteriza por una pérdida progresiva de neuronas productoras de dopamina en la sustancia negra y la aparición de acumulaciones proteicas que se depositan en las neuronas formando estructuras que se denominan cuerpos de Lewy. Los modelos que existen para estudiar este trastorno en animales no son buenos porque no reproducen bien la enfermedad, así que cualquier avance en este sentido supone un paso más para, en un futuro, conocer mejor las causas que están detrás de esta enfermedad.
Sin embargo, con la llegada de las iPS, células de pluripotencialidad inducida, este panorama puede cambiar. Esta tecnología, desarrollada por el científico japonés Shinya Yamanaka, transforma células adultas (de la piel o de otras estructuras) en células madre similares a las embrionarias que luego pueden convertirse en otro tipo de células distintas de las originales. Si este procedimiento se utiliza en personas con enfermedades incurables o patologías raras, es posible investigar directamente sobre sus neuronas, no las de su cerebro sino las que se han producido a partir de una muestra de su piel.
"La tecnología de las iPS tiene el potencial de revolucionar nuestra compresión del Parkinson, porque ofrece la oportunidad de generar y estudiar células afectadas (por este trastorno) directamente de pacientes. Este enfoque ya ha sido utilizado para generar modelos celulares de diferentes trastornos neurológicos: esclerosis lateral amiotrófica, Parkinson esporádico, atrofia muscular espinal y disautonomía familiar", explican los autores del trabajo.
El estudio, realizado por investigadores de universidades de Edimburgo y Londres, utilizó células de la piel de un paciente con un tipo de Parkinson que progresa rápidamente y que puede diagnosticarse a los 30 años. Las personas con esta forma de la enfermedad tienen el doble del número de aquellos genes que producen la proteína, denominada alfa-sinucleina, que es la que se suele depositar en las neuronas.
Ésta no es la primera investigación que emplea las iPS para estudiar el Parkinson, el pasado mes de marzo científicos de la Universidad de Standford (EEUU) publicaron un estudio en el que se había utilizado esta tecnología en otro tipo de Parkinson. Sin embargo, el trabajo que hoy se publica en la revista Nature Communications fija su atención en la forma de rápido progreso.
"Comprender esta forma progresiva del trastorno nos ayudará a entender otros tipos de Parkinson. Al mismo tiempo, al evolucionar rápidamente nos facilita seguir los efectos de los fármacos utilizados para prevenir el daño neuronal por la enfermedad", explica el doctor Michael Devine, del Instituto de Neurología de la University College London.
Por su parte, Kieran Breen, director de Investigación y Desarrollo de la Parkinson's UK (organización que patrocinó el estudio con 300.000 libras), ha señalado que "aunque la mutación genética que conduce a esta forma progresiva de Parkinson es rara, este apasionante estudio tiene el potencial de traernos una gran cantidad de avances en la investigación contra el Parkinson".
La enfermedad de Parkison es el más frecuente de los trastornos neurodegenerativos. Se caracteriza por una pérdida progresiva de neuronas productoras de dopamina en la sustancia negra y la aparición de acumulaciones proteicas que se depositan en las neuronas formando estructuras que se denominan cuerpos de Lewy. Los modelos que existen para estudiar este trastorno en animales no son buenos porque no reproducen bien la enfermedad, así que cualquier avance en este sentido supone un paso más para, en un futuro, conocer mejor las causas que están detrás de esta enfermedad.
Sin embargo, con la llegada de las iPS, células de pluripotencialidad inducida, este panorama puede cambiar. Esta tecnología, desarrollada por el científico japonés Shinya Yamanaka, transforma células adultas (de la piel o de otras estructuras) en células madre similares a las embrionarias que luego pueden convertirse en otro tipo de células distintas de las originales. Si este procedimiento se utiliza en personas con enfermedades incurables o patologías raras, es posible investigar directamente sobre sus neuronas, no las de su cerebro sino las que se han producido a partir de una muestra de su piel.
"La tecnología de las iPS tiene el potencial de revolucionar nuestra compresión del Parkinson, porque ofrece la oportunidad de generar y estudiar células afectadas (por este trastorno) directamente de pacientes. Este enfoque ya ha sido utilizado para generar modelos celulares de diferentes trastornos neurológicos: esclerosis lateral amiotrófica, Parkinson esporádico, atrofia muscular espinal y disautonomía familiar", explican los autores del trabajo.
El estudio, realizado por investigadores de universidades de Edimburgo y Londres, utilizó células de la piel de un paciente con un tipo de Parkinson que progresa rápidamente y que puede diagnosticarse a los 30 años. Las personas con esta forma de la enfermedad tienen el doble del número de aquellos genes que producen la proteína, denominada alfa-sinucleina, que es la que se suele depositar en las neuronas.
Ésta no es la primera investigación que emplea las iPS para estudiar el Parkinson, el pasado mes de marzo científicos de la Universidad de Standford (EEUU) publicaron un estudio en el que se había utilizado esta tecnología en otro tipo de Parkinson. Sin embargo, el trabajo que hoy se publica en la revista Nature Communications fija su atención en la forma de rápido progreso.
"Comprender esta forma progresiva del trastorno nos ayudará a entender otros tipos de Parkinson. Al mismo tiempo, al evolucionar rápidamente nos facilita seguir los efectos de los fármacos utilizados para prevenir el daño neuronal por la enfermedad", explica el doctor Michael Devine, del Instituto de Neurología de la University College London.
Por su parte, Kieran Breen, director de Investigación y Desarrollo de la Parkinson's UK (organización que patrocinó el estudio con 300.000 libras), ha señalado que "aunque la mutación genética que conduce a esta forma progresiva de Parkinson es rara, este apasionante estudio tiene el potencial de traernos una gran cantidad de avances en la investigación contra el Parkinson".
**Publicado en "EL MUNDO"
2-year-old children understand complex grammar
Psychologists at the University of Liverpool have found that children as young as two years old have an understanding of complex grammar even before they have learned to speak in full sentences. Researchers at the University's Child Language Study Centre showed children, aged two, sentences containing made-up verbs, such as 'the rabbit is glorping the duck', and asked them to match the sentence with a cartoon picture. They found that even the youngest two-year-old could identify the correct image with the correct sentence, more often than would be expected by chance.
The study suggests that infants know more about language structure than they can actually articulate, and at a much earlier age than previously thought. The work also shows that children may use the structure of sentences to understand new words, which may help explain the speed at which infants acquire speech.
Dr Caroline Rowland, from the University's Institute of Psychology, Health and Society, said: "When acquiring a language, children must learn not only the meaning of words but also how to combine words to convey meaning. Most two year olds rarely combine more than two words together. They may say 'more juice' or 'no hat', but don't know how to form full sentences yet.
"Studies have suggested that children between the ages of two and three start to build their understanding of grammar gradually from watching and listening to people. More recent research, however, has suggested that even at 21 months infants are sensitive to the different meanings produced by particular grammatical construction, even if they can't articulate words properly.
"We tested this theory by showing two-year-old children pictures of a cartoon rabbit and duck. One picture was the rabbit acting on the duck, lifting the duck's leg for example, and the other was an image of the animals acting independently, such as swinging a leg. We then played sentences with made-up verbs -- the rabbit is glorping the duck -- over a loudspeaker and asked them to point to the correct picture. They picked out the correct image more often than we would expect them to by chance.
"Our work suggests that the words that children say aren't necessarily the extent of what they actually know about language and grammar. The beginnings of grammar acquisition start much earlier than previously thought, but more importantly it demonstrates that children can use grammar to help them work out the meaning of new words, particularly those that don't correspond to concrete objects such as 'know' and 'love'. Children can use the grammar of sentence to narrow down possible meanings, making it much easier for them to learn."
The research is published in the journal Cognitive Science.
**Source: University of Liverpool
The study suggests that infants know more about language structure than they can actually articulate, and at a much earlier age than previously thought. The work also shows that children may use the structure of sentences to understand new words, which may help explain the speed at which infants acquire speech.
Dr Caroline Rowland, from the University's Institute of Psychology, Health and Society, said: "When acquiring a language, children must learn not only the meaning of words but also how to combine words to convey meaning. Most two year olds rarely combine more than two words together. They may say 'more juice' or 'no hat', but don't know how to form full sentences yet.
"Studies have suggested that children between the ages of two and three start to build their understanding of grammar gradually from watching and listening to people. More recent research, however, has suggested that even at 21 months infants are sensitive to the different meanings produced by particular grammatical construction, even if they can't articulate words properly.
"We tested this theory by showing two-year-old children pictures of a cartoon rabbit and duck. One picture was the rabbit acting on the duck, lifting the duck's leg for example, and the other was an image of the animals acting independently, such as swinging a leg. We then played sentences with made-up verbs -- the rabbit is glorping the duck -- over a loudspeaker and asked them to point to the correct picture. They picked out the correct image more often than we would expect them to by chance.
"Our work suggests that the words that children say aren't necessarily the extent of what they actually know about language and grammar. The beginnings of grammar acquisition start much earlier than previously thought, but more importantly it demonstrates that children can use grammar to help them work out the meaning of new words, particularly those that don't correspond to concrete objects such as 'know' and 'love'. Children can use the grammar of sentence to narrow down possible meanings, making it much easier for them to learn."
The research is published in the journal Cognitive Science.
**Source: University of Liverpool
Científicos británicos trabajan en un prometedor líquido que regenera el diente picado sin necesidad de perforar ni rellenar
Si hay alguien a quien los niños, y no tan niños, tienen más miedo que al «coco» ese es el dentista. Sobre todo cuando el taladro está de por medio. Solo el ruido de la herramienta ya pone a muchos de los nervios. Pero esta desagradable práctica puede tener los días contados.
Investigadores de la Universidad de Leeds han descubierto un tratamiento que, según aseguran sus creadores, acaba con las caries y reconstruye el diente de forma natural e indolora.
La caries comienza cuando el ácido producido por la placa disuelve el mineral de los dientes, causando agujeros microscópicos que van aumentando en tamaño y número. Finalmente, el diente dañado tiene que ser perforado y rellenado, o incluso extraído.
El miedo al dolor hace que muchos pacientes no vayan al dentista cuando notan dolores o detectan alguna pequeña caries en su dentadura. Ignorarlo no frena su desarrollo y al final tenemos que enfrentarnos a un tratamiento más complejo y molesto que en un principio.
Para evitar estas situaciones, los investigadores de la Universidad de Leeds han desarrollado un revolucionario fluido, a base de un tipo de un péptido, que se aplica en la superficie de los dientes para tratar los primeros signos de la caries. Esta tecnología, basada en la formación natural del diente, estimula la regeneración de la pieza defectuosa.
«Esto suena demasiado bien para ser verdad, pero nosotros lo que hacemos, básicamente, es ayudar a los dientes a autoregenerarse. Es un proceso reparador no quirúrgico, totalmente natural e indoloro», asegura la profesora Jennifer Kirkham, que ha liderado el desarrollo de esta nueva técnica en el Instituto Dental de la Universidad de Leeds.
-Cómo actúa
El líquido «mágico», como lo denominan sus creadores, ha sido diseñado por científicos de la Facultad de Químicas de la misma universidad. Contiene un péptido conocido como P 11-4 que, bajo ciertas condiciones, se ensambla entre las fibras. En la práctica, el líquido, en contacto con el diente, se convierte en un gel que, fijado como un «andamio», atrae el calcio y remineraliza la pieza dental desde el interior, de forma natural.
Este tratamiento ha sido probado recientemente en un pequeño grupo de adultos que presentaban los primeros síntomas de la caries. Los resultados de este pequeño ensayo han revelado que el péptido P 11-4 puede revertir el daño y regenerar el tejido del diente.
«Los resultados de nuestros tests son muy prometedores», afirma el profesor Paul Brunton, que supervisa las pruebas con pacientes. En este sentido, el investigador señala que, si estos resultados se pueden repetir en un grupo de pacientes más grande, «en dos o tres años esta técnica estará disponible en las consultas de los dentistas».
Un tratamiento que, si sale adelante, acabaría con el vínculo entre dentista y dolor y permitiría a los pacientes mantener sus dientes naturales.
**Publicado en "ABC"
Interventional cardiologists' exposure to radiation prompts cellular changes that may protect body from harm
Cardiologists who perform heart operations using x-ray guided catheters are exposed to ionising radiation at levels two to three times higher per year than those experienced by radiologists. Now, new research has found the first evidence that these constant, high levels of exposure cause changes at cell level that might represent the body’s way of protecting itself against the harmful effects of radiation. The research, published online today in the European Heart Journal, found that among ten interventional cardiologists who were regularly exposed to x-rays for their work, levels of two chemicals rose: one, glutathione, an anti-oxidant that protects against cell damage from oxygen-containing molecules called ‘reactive oxygen species’ (ROS), and the other, hydrogen peroxide, which indicates the amount of oxidative stress caused by the ROS.
In addition, lymphocyte cells showed increased levels of an enzyme called caspase-3, which is involved in programmed cell death (known as apoptosis) and which indicated an increased susceptibility of these cells (which are part of the body’s immune system) to apoptosis. The authors of the research, led by Dr Eugenio Picano, director of the Institute of Clinical Physiology at the Italian National Research Council (CNR) in Pisa, Italy, believe that these changes indicate that the radiation was inducing potentially harmful changes at the cellular level (as indicated by the three-fold increase in hydrogen peroxide), but that this in turn prompted a protective response, reflected by an almost two-fold increase in the antioxidant glutathione and an increased susceptibility of white blood cells to apoptosis, which could be the body’s way of killing off damaged and potentially cancerous cells.
The first author of the study, Dr Gian Luigi Russo, a senior research scientist at the CNR’s Institute of Food Sciences in Avellino (Italy), said: “Our findings clearly emphasise for the first time that exposure to a level of radiation, which is considered ‘safe’ by regulatory standards for interventional cardiologists, can induce a profound biochemical and cellular adaptation whereby increases in the levels of reactive oxygen species in these workers are balanced by an improvement in antioxidant defences. We also observed an increased susceptibility of lymphocytes to apoptosis, which may represent a compensatory mechanism to efficiently remove genetically damaged cells. “It remains unclear whether these changes are adaptive, beneficial modifications or the harbinger of clinically relevant adverse changes, since increased DNA damage, oxidative stress and apoptotic activity have been involved in the development of a variety of diseases.
” Interventional cardiologists are part of a larger population of about 23 million people worldwide (excluding military personnel) who are exposed professionally to ionising radiation. About seven million are medical workers who can be exposed to x-rays (e.g. interventional cardiologist) or to gamma-rays (e.g. workers in nuclear medicine). Over the past 20 years the interventional cardiologists’ exposure to radiation has risen as the number of x-ray guided interventions has increased; in the USA cardiac catheterisation procedures have increased from 2.45 million in 1993 to 4.6 million in 2006, with similar trends seen in Europe. Dr Picano said: “Each procedure involves a large radiation exposure to the patient, which may range from the equivalent of 300 to 5,000 chest x-rays and more, with an average dose of 750 chest X-rays for a percutaneous coronary intervention or a cardiac radiofrequency ablation. Interventional cardiologists must work close to the source of x-rays, and this explains why their own professional exposure is three times higher than that of radiologists, and can be equivalent to the dose of 250 chest x-rays per head per year. After 30 years of work, this corresponds to a lifetime’s increased risk of developing cancer of approximately one in 100, although there is still some uncertainty in these risk estimates.” The researchers compared 10 interventional cardiologists with 10 health workers who were not exposed to radiation. Information on the cardiologists’ exposure to radiation was obtained from their radiation badges and their lifetime exposure calculated from these data. The researchers took blood samples in order to test for glutathione, hydrogen peroxide and caspase-3.
Dr Russo concluded: “Our findings have clinical and scientific implications. Interventional cardiologists should make every effort in their daily practice to minimise their exposure, as we know that if there is a radioprotection culture in the catheterisation laboratory, then the same activity can be done with a dose reduction of 90% for doctors, staff and patients. From the scientific perspective, invasive cardiologists today have a unique opportunity to clarify the effects of chronic low dose exposure. A large study, called the Healthy Cath Lab study, is being conducted in Italy to address this question. It is done by interventional cardiologists on interventional cardiologists and for interventional cardiologists, with the aim to clarify the cancer and non-cancer effects of chronic low dose radiation exposure. “A good cardiologist should not be afraid of life-saving radiation, but must be afraid of radiation unawareness and negligence.” In an accompanying editorial [2], Professor Thomas Münzel and Dr Tommaso Gori from the Department of Cardiology at the University Medical Centre of Mainz (Mainz, Germany), point to some of the limitations of the study (its small size, incomplete insight on the mechanisms involved, differences in body mass index and lack of information on other cardiovascular risk factors) but write that despite this, the study is interesting. “While interventionalists were subject to more radiation-induced oxidative stress (or rather, in response to radiation-induced stress), fortunately they developed (partial) counter-regulatory antioxidant defences.” They agreed with Dr Russo about the need for both more research and more awareness of protective measures by cardiologists. “In conclusion, more research is necessary, both at the level of basic science to understand the interaction between toxic . . . effects of ionizing radiations and hormesis phenomena, and at the level of epidemiology. While the effects of ionizing radiation remain incompletely understood, it is our responsibility as physicians to take all precautions in reducing any potential hazard to our patients, our colleagues and ourselves. The beauty of modern medical images, the personal sense of self-achievement that follows a complex, prolonged interventional procedure, must be balanced by their costs, clinical utility and risks – not least, that of prolonged operator’s exposure to radiations,” they write in their editorial.
In addition, lymphocyte cells showed increased levels of an enzyme called caspase-3, which is involved in programmed cell death (known as apoptosis) and which indicated an increased susceptibility of these cells (which are part of the body’s immune system) to apoptosis. The authors of the research, led by Dr Eugenio Picano, director of the Institute of Clinical Physiology at the Italian National Research Council (CNR) in Pisa, Italy, believe that these changes indicate that the radiation was inducing potentially harmful changes at the cellular level (as indicated by the three-fold increase in hydrogen peroxide), but that this in turn prompted a protective response, reflected by an almost two-fold increase in the antioxidant glutathione and an increased susceptibility of white blood cells to apoptosis, which could be the body’s way of killing off damaged and potentially cancerous cells.
The first author of the study, Dr Gian Luigi Russo, a senior research scientist at the CNR’s Institute of Food Sciences in Avellino (Italy), said: “Our findings clearly emphasise for the first time that exposure to a level of radiation, which is considered ‘safe’ by regulatory standards for interventional cardiologists, can induce a profound biochemical and cellular adaptation whereby increases in the levels of reactive oxygen species in these workers are balanced by an improvement in antioxidant defences. We also observed an increased susceptibility of lymphocytes to apoptosis, which may represent a compensatory mechanism to efficiently remove genetically damaged cells. “It remains unclear whether these changes are adaptive, beneficial modifications or the harbinger of clinically relevant adverse changes, since increased DNA damage, oxidative stress and apoptotic activity have been involved in the development of a variety of diseases.
” Interventional cardiologists are part of a larger population of about 23 million people worldwide (excluding military personnel) who are exposed professionally to ionising radiation. About seven million are medical workers who can be exposed to x-rays (e.g. interventional cardiologist) or to gamma-rays (e.g. workers in nuclear medicine). Over the past 20 years the interventional cardiologists’ exposure to radiation has risen as the number of x-ray guided interventions has increased; in the USA cardiac catheterisation procedures have increased from 2.45 million in 1993 to 4.6 million in 2006, with similar trends seen in Europe. Dr Picano said: “Each procedure involves a large radiation exposure to the patient, which may range from the equivalent of 300 to 5,000 chest x-rays and more, with an average dose of 750 chest X-rays for a percutaneous coronary intervention or a cardiac radiofrequency ablation. Interventional cardiologists must work close to the source of x-rays, and this explains why their own professional exposure is three times higher than that of radiologists, and can be equivalent to the dose of 250 chest x-rays per head per year. After 30 years of work, this corresponds to a lifetime’s increased risk of developing cancer of approximately one in 100, although there is still some uncertainty in these risk estimates.” The researchers compared 10 interventional cardiologists with 10 health workers who were not exposed to radiation. Information on the cardiologists’ exposure to radiation was obtained from their radiation badges and their lifetime exposure calculated from these data. The researchers took blood samples in order to test for glutathione, hydrogen peroxide and caspase-3.
Dr Russo concluded: “Our findings have clinical and scientific implications. Interventional cardiologists should make every effort in their daily practice to minimise their exposure, as we know that if there is a radioprotection culture in the catheterisation laboratory, then the same activity can be done with a dose reduction of 90% for doctors, staff and patients. From the scientific perspective, invasive cardiologists today have a unique opportunity to clarify the effects of chronic low dose exposure. A large study, called the Healthy Cath Lab study, is being conducted in Italy to address this question. It is done by interventional cardiologists on interventional cardiologists and for interventional cardiologists, with the aim to clarify the cancer and non-cancer effects of chronic low dose radiation exposure. “A good cardiologist should not be afraid of life-saving radiation, but must be afraid of radiation unawareness and negligence.” In an accompanying editorial [2], Professor Thomas Münzel and Dr Tommaso Gori from the Department of Cardiology at the University Medical Centre of Mainz (Mainz, Germany), point to some of the limitations of the study (its small size, incomplete insight on the mechanisms involved, differences in body mass index and lack of information on other cardiovascular risk factors) but write that despite this, the study is interesting. “While interventionalists were subject to more radiation-induced oxidative stress (or rather, in response to radiation-induced stress), fortunately they developed (partial) counter-regulatory antioxidant defences.” They agreed with Dr Russo about the need for both more research and more awareness of protective measures by cardiologists. “In conclusion, more research is necessary, both at the level of basic science to understand the interaction between toxic . . . effects of ionizing radiations and hormesis phenomena, and at the level of epidemiology. While the effects of ionizing radiation remain incompletely understood, it is our responsibility as physicians to take all precautions in reducing any potential hazard to our patients, our colleagues and ourselves. The beauty of modern medical images, the personal sense of self-achievement that follows a complex, prolonged interventional procedure, must be balanced by their costs, clinical utility and risks – not least, that of prolonged operator’s exposure to radiations,” they write in their editorial.
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