Posts tagged diseases
Articles and news from the latest research reports.
Zebrafish Genome Found Strikingly Similar to Humans
According to a paper published in Nature, 70 per cent of protein-coding human genes are related to genes found in the zebrafish (Danio rerio), and 84 per cent of genes known to be associated with human disease have a zebrafish counterpart.
The team developed a high-quality annotated zebrafish genome sequence to compare with the human reference genome. Only two other large genomes have been sequenced to this high standard: the human genome and the mouse genome. The completed zebrafish genome will be an essential resource that drives the study of gene function and disease in people.
Zebrafish are remarkably biologically similar to people and share the majority of the same genes as humans, making them an important model for understanding how genes work in health and disease.
“Our aim with this project, like with all biomedical research, is to improve human health. This genome will allow researchers to understand how our genes work and how genetic variants can cause disease in ways that cannot be easily studied in humans or other organisms,” said study senior author Dr Derek Stemple of the Wellcome Trust Sanger Institute.
Zebrafish research has already led to biological advances in cancer and heart disease research, and is advancing our understanding of muscle and organ development. Zebrafish have been used to verify the causal gene in muscular dystrophy disorders and also to understand the evolution and formation of melanomas or skin cancers.
“The vast majority of human genes have counterparts in the zebrafish, especially genes related to human disease. This high quality genome is testament to the many scientists who worked on this project and will spur biological research for years to come. By modeling these human disease genes in zebrafish, we hope that resources worldwide will produce important biological information regarding the function of these genes and possibly find new targets for drug development,” explained senior author Prof Jane Rogers, also of the Wellcome Trust Sanger Institute.
The zebrafish genome has some unique features, not seen in other vertebrates. They have the highest repeat content in their genome sequences so far reported in any vertebrate species: almost twice as much as seen in their closest relative, the common carp. Also unique to the zebrafish, the team identified chromosomal regions that influence sex determination.
The zebrafish genome contains few pseudogenes – genes thought to have lost their function through evolution – compared to the human genome.
The team identified 154 pseudogenes in the zebrafish genome, a fraction of the 13,000 or so pseudogenes found in the human genome.
“To realize the benefits the zebrafish can make to human health, we need to understand the genome in its entirety – both the similarities to the human genome and the differences. Armed with the zebrafish genome, we can now better understand how changes to our genomes result in disease,” said Prof Christiane Nüsslein-Volhard, co-author and Nobel laureate from the Max Planck Institute for Developmental Biology.
“This genome will help to uncover the biological processes responsible for common and rare disease and opens up exciting new avenues for disease screening and drug development,” Dr Stemple said.
New Research Shows Music Improves Health and Disease
Music has been incorporated into medical practice since before the ancient Greeks. However, though practitioners have been convinced of music’s health benefits for thousands of years, there had been little peer-reviewed research to back them up. But recent studies are providing an empirical backbone for the anecdotal evidence. A 2012 scientific review, published in the journal Nutrition, collects information from a number of studies to support music’s influence on the hypothalamic-pituitary-adrenal (HPA) axis, the sympathetic nervous system (SNS) and the immune system. These results support the experiences of complementary practitioners, who have long used music to help heal.
“As an integrative physician and traditional Chinese medicine practitioner, the healing power of music has always been an important part of my practice and family life,” says integrative medicine pioneer Isaac Eliaz, M.D. “Harmony and tempo help synchronize the rhythms of the natural world with the music of the heart – each person’s individual energetic pattern, expressed in their pulse.”
Proven Medicine
The review highlighted a number of studies that confirm music’s healing potential. For example, music reduces levels of serum cortisol in the blood. An important player in the HPA axis, cortisol increases metabolic activity, suppresses the immune system and has been associated with both anxiety and depression. A number of studies have shown that exposing post-operative patients to music dramatically lowers their cortisol levels, enhancing their ability to heal.
Other studies in the review measured music’s impact on congestive heart failure, premature infants, immunity, digestive function and pain perception. In particular, music’s effects on the limbic and hypothalamic systems reduced the incidence of heart failure. Other studies showed that surgical patients required less sedation and post-operative pain medication.
“These results only confirm what I have observed for many years in my practice,” says Dr. Eliaz. “Music produces quantifiable healing. For example, my daughter Amity, a professional musician, regularly plays her songs for chronically ill patients who express how uplifting her music is. These performances do more than encourage good feelings, they help the body heal on a molecular level.”
Powerful Impact
Perhaps the most interesting aspect of music’s healing properties is how widespread they are. For example, music also aided recovery time following strenuous exercise. Other studies showed that fast-paced music can increase resting metabolism, which may prove helpful for people trying to lose weight.
“Modern science has just begun to scratch the surface of music and sound in terms of healing potential,” says Dr. Eliaz. “However, traditional medical systems from around the world have long revered the beneficial vibrations of music, harmony and rhythm for health and vitality. The effects are instant and tangible, but they are also powerful and long lasting.”
Researchers uncover major source of evolutionary differences among species
University of Toronto Faculty of Medicine researchers have uncovered a genetic basis for fundamental differences between humans and other vertebrates that could also help explain why humans are susceptible to diseases not found in other species.
Scientists have wondered why vertebrate species, which look and behave very differently from one another, nevertheless share very similar repertoires of genes. For example, despite obvious physical differences, humans and chimpanzees share a nearly identical set of genes.
The team sequenced and compared the composition of hundreds of thousands of genetic messages in equivalent organs, such as brain, heart and liver, from 10 different vertebrate species, ranging from human to frog. They found that alternative splicing — a process by which a single gene can give rise to multiple proteins — has dramatically changed the structure and complexity of genetic messages during vertebrate evolution.
The results suggest that differences in the ways genetic messages are spliced have played a major role in the evolution of fundamental characteristics of species. However, the same process that makes species look different from one another could also account for differences in their disease susceptibility.
"The same genetic mechanisms responsible for a species’ identity could help scientists understand why humans are prone to certain diseases such as Alzheimer’s and particular types of cancer that are not found in other species," says Nuno Barbosa-Morais, the study’s lead author and a computational biologist in U of T Faculty of Medicine’s Donnelly Centre for Cellular and Biomolecular Research. "Our research may lead to the design of improved approaches to study and treat human diseases."
One of the team’s major findings is that the alternative splicing process is more complex in humans and other primates compared to species such as mouse, chicken and frog.
"Our observations provide new insight into the genetic basis of complexity of organs such as the human brain," says Benjamin Blencowe, Professor in U of T’s Banting and Best Department of Research and the Department of Molecular Genetics, and the study’s senior author.
"The fact that alternative splicing is very different even between closely related vertebrate species could ultimately help explain how we are unique."
We all have hundreds of DNA flaws, UK geneticists say
Everyone has on average 400 flaws in their DNA, a UK study suggests. Most are “silent” mutations and do not affect health, although they can cause problems when passed to future generations. Others are linked to conditions such as cancer or heart disease, which appear in later life, say geneticists.
The evidence comes from the 1,000 Genomes project, which is mapping normal human genetic differences, from tiny changes in DNA to major mutations.
In the study, 1,000 seemingly healthy people from Europe, the Americas and East Asia had their entire genetic sequences decoded, to look at what makes people different from each other, and to help in the search for genetic links to diseases.
The new research, published in The American Journal of Human Genetics, compared the genomes of 179 participants, who were healthy at the time their DNA was sampled, with a database of human mutations developed at Cardiff University.
It revealed that a normal healthy person has on average about 400 potentially damaging DNA variations, and two DNA changes known to be associated with disease.
"Ordinary people carry disease-causing mutations without them having any obvious effect," said Dr Chris Tyler-Smith, a lead researcher on the study from the Wellcome Trust Sanger Institute, Cambridge.
He added: “In a population there will be variants that have consequences for their own health.”
The research gives an insight into the “flaws that make us all different, sometimes with different expertise and different abilities, but also different predispositions in diseases,” said Prof David Cooper of Cardiff University, the other lead researcher of the study.
Computational Medicine Begins to Enhance the Way Doctors Detect and Treat Disease
Computational medicine, a fast-growing method of using computer models and sophisticated software to figure out how disease develops–and how to thwart it–has begun to leap off the drawing board and land in the hands of doctors who treat patients for heart ailments, cancer and other illnesses. Using digital tools, researchers have begun to use experimental and clinical data to build models that can unravel complex medical mysteries.
These are some of the conclusions of a new review of the field published in the Oct. 31 issue of the journal Science Translational Medicine. The article, “Computational Medicine: Translating Models to Clinical Care,” was written by four Johns Hopkins professors affiliated with the university’s Institute for Computational Medicine.
In recent years, “The field has exploded. There is a whole new community of people being trained in mathematics, computer science and engineering, and they are being cross-trained in biology,” said institute director Raimond Winslow. “This allows them to bring a whole new perspective to medical diagnosis and treatment. Engineers traditionally construct models of the systems they are designing. In our case, we’re building computational models of what we trying to study, which is disease.”
Global Genome Effort Seeks Genetic Roots of Disease
By decoding the genomes of more than 1,000 people whose homelands stretch from Africa and Asia to Europe and the Americas, scientists have compiled the largest and most detailed catalog yet of human genetic variation. The massive resource will help medical researchers find the genetic roots of rare and common diseases in populations worldwide.
The 1000 Genomes Project involved some 200 scientists at Washington University School of Medicine in St. Louis and other institutions. Results detailing the DNA variations of individuals from 14 ethnic groups are published Oct. 31 in the journal Nature. Eventually, the initiative will involve 2,500 individuals from 26 populations.
“With this resource, researchers have a roadmap to search for the genetic origins of diseases in populations around the globe,” says one of the study’s co-principal investigators, Elaine Mardis, PhD, co-director of The Genome Institute at Washington University. “We estimate that each person carries up to several hundred rare DNA variants that could potentially contribute to disease. Now, scientists can investigate how detrimental particular rare variants are in different ethnic groups.”
Life without the Neurobeachin Protein
Scientists at Freie Universität, Universität Hohenheim, and Katholieke Universiteit Leuven Breed Fruit Flies for First Time without the Neurobeachin Protein and Facilitate Study of Nervous Diseases in Humans
In experiments on the brain of the fruit fly Drosophila, scientists at Freie Universität Berlin have advanced the research on brain function and diseases in humans. Neuroscientists in the Emmy Noether Junior Research Group “Biological Memory Systems” headed by Dr. Martin Schwärzel and based at Freie Universität succeeded in breeding fruit flies without the neurobeachin protein. Among other things, BEACH proteins affect the development and function of the brain in animals and humans. The results were published in the most recent issue of The Journal of Neuroscience. In the future such animal models could be of particular importance for the understanding of certain diseases in humans, such as autism. Scientists from the University of Hohenheim and the Belgian Katholieke Universiteit Leuven were also involved.
Up to now there were no animal models suitable for understanding the significance of neurobeachin proteins in the functioning of the nervous system, for example in memory formation. Mice that are lacking the neurobeachin protein die shortly after birth. Fruit flies, on the other hand, can be alive and well without neurobeachin. The scientists also found in experiments on the flies that neurobeachin has a function in learning as the flies exhibit characteristic learning disabilities due to the absence of the protein.
The flies were also found to have a number of other abnormalities with regard to the development and function of the nervous system. Through a “genetic rescue experiment,” the researchers were able to localize the distribution of these defects in the brain. The function of the lacking neurobeachin gene was reintroduced in certain areas of the nervous system. With this procedure, the researchers were able to show, among other things, that certain features of the neurobeachin protein in flies and mice are identical.
(Source: fu-berlin.de)
Scientists Identify New Stem Cells with Therapeutic Potential
The discovery, published in the journal PLOS Biology, offers new opportunities in the treatment of cardiovascular diseases, cancer and many other diseases.
The growth of new blood vessels – angiogenesis – occurs during the repair of damaged tissue and organs in adults. However, malignant tumors also grow new blood vessels in order to receive oxygen and nutrients. As such, angiogenesis is both beneficial and detrimental to health, depending on the context, requiring therapeutic approaches that can either help to stimulate or prevent it. Therapeutics that aim to prevent the growth of new blood vessels are already in use, but the results are often more modest than predicted.
For more than a decade, Prof Petri Salvén of the University of Helsinki and his colleagues have studied the mechanisms of angiogenesis to discover how blood vessel growth could be prevented or accelerated effectively.
“We succeeded in isolating endothelial cells with a high rate of division in the blood vessel walls of mice. We found these same cells in human blood vessels and blood vessels growing in malignant tumors in humans. These cells are known as vascular endothelial stem cells. In a cell culture, one such cell is capable of producing tens of millions of new blood vessel wall cells,” Prof Salvén said.
From their studies in mice, the team was able to show that the growth of new blood vessels weakens, and the growth of malignant tumors slows, if the amount of these cells is below normal. Conversely, new blood vessels form where these stem cells are implanted.
Controlling Brains With a Flick of a Light Switch
Using the new science of optogenetics, scientists can activate or shut down neural pathways, altering behavior and heralding a true cure for psychiatric disease.
Stopped at a red light on his drive home from work, Karl Deisseroth contemplates one of his patients, a woman with depression so entrenched that she had been unresponsive to drugs and electroshock therapy for years. The red turns to green and Deisseroth accelerates, navigating roads and intersections with one part of his mind while another part considers a very different set of pathways that also can be regulated by a system of lights. In his lab at Stanford University’s Clark Center, Deisseroth is developing a remarkable way to switch brain cells off and on by exposing them to targeted green, yellow, or blue flashes. With that ability, he is learning how to regulate the flow of information in the brain.
Deisseroth’s technique, known broadly as optogenetics, could bring new hope to his most desperate patients. In a series of provocative experiments, he has already cured the symptoms of psychiatric disease in mice. Optogenetics also shows promise for defeating drug addiction. When Deisseroth exposed a set of test mice to cocaine and then flipped a switch, pulsing bright yellow light into their brains, the expected rush of euphoria—the prelude to addiction—was instantly blocked. Almost miraculously, they were immune to the cocaine high; the mice left the drug den as uninterested as if they had never been exposed.
Pill for healthy ageing ‘available within a generation’
Dame Linda Partridge, a geneticist at University College London, claimed drugs will soon be available which can lower the risk of diseases like cancer and dementia by tackling the root cause – age itself.
Rather than promising immortality, taking the drugs from middle age or earlier could dramatically shorten the period of illness and frailty that we typically experience before we die.
Speaking at the EMBO life sciences meeting in Nice, France this week Dame Linda said several existing drugs have already been shown to have unexpected and welcome side effects, such as aspirin which reduces the risk of cancer.
Other therapies will be produced that mimic the effects of a severely restricted diet, which animal studies suggest can protect against a host of age-related conditions including heart disease and diabetes, she said.
Speaking after her keynote lecture, she told The Daily Telegraph: “One obvious approach in trying to deal with the very rapidly increasing incidence of age related diseases is to tackle the underlying aging process itself, because it is the major risk factor.