Archive for April 2010
Genomic data will soon become a commodity; the next challenge — linking human genetic variation with physiology and disease — will be as great as the one genomicists faced a decade ago, says J. Craig Venter.
Two new studies add to evidence that older people with low levels of vitamin D may be more likely to suffer from cognitive impairment.
The hope is that vitamin D supplements may be able to slow mental decline — an intervention that one research team plans to put to the test this summer.
Vitamin D is best known for helping the body absorb calcium, which restores and strengthens bone, protecting against fracture.
But vitamin D also seems to have anti-inflammatory effects that may help keep blood vessels healthy, ensuring nutrient- and oxygen-rich blood flow to brain cells, says Amie Peterson, MD, of Oregon Health & Science University in Portland.
In addition, the presence of vitamin D receptors throughout the brain suggests that it may directly affect brain tissue, she tells WebMD.
Why does a commercial dairy cow produce four times as much milk as most other mammals? Why do we look like our cousins? Why do roses come in so many different colors? The answers to these and other questions about the diversity of living things involve processes that occur at the level of genes.
Essentials of Genetics is a brief guide through the core concepts of how genes are structured and how they drive biological diversity. This course can be used as a guide for introductory biology students, as a reference for advanced students, or as a self-guided exploration for general science enthusiasts. Topics covered include the nature of DNA and its relationship to the physical characteristics of organisms; the passage of DNA from organism to organism; and the variation of DNA within and across populations of organisms. Essentials of Genetics also connects these core concepts to the scientific process by discussing the key tools used to study DNA in the laboratory. Alongside each concept are links to biographies of scientists who made major contributions to the field, as well as to a broad set of detailed readings on advanced topics in modern genetics. Finally, Essentials of Genetics combines its descriptions of various core concepts with high-quality video animations of molecular processes to stimulate an intuitive physical understanding of genetics.
IF a lover breaks your heart, tissue engineers can’t fix it. But if sticks and stones break your bones, scientists may be able to grow custom-size replacements.
Gordana Vunjak-Novakovic, a professor of biomedical engineering at Columbia University, has solved one of many problems on the way to successful bone implants: how to grow new bones in the anatomical shape of the original.
Dr. Vunjak-Novakovic and her research team have created and nourished two small bones from scratch in their laboratory. The new bones, part of a joint at the back of the jaw, were created with human stem cells. The shape is based on digital images of undamaged bones.
Television’s Six Million Dollar Man foresaw a future when man and machine would become one. New research at Tel Aviv University is making this futuristic “vision” of bionics a reality.
Prof. Yael Hanein of Tel Aviv University’s School of Electrical Engineering has foundational research that may give sight to blind eyes, merging retinal nerves with electrodes to stimulate cell growth. Successful so far in animal models, this research may one day lay the groundwork for retinal implants in people.
But that’s a way off, she says. Until then, her half-human, half-machine invention can be used by drug developers investigating new compounds or formulations to treat delicate nerve tissues in the brain. Prof. Hanein’s research group published its work recently in the journal Nanotechnology.
Like many people, rats are happy to gorge themselves on tasty, high-fat treats. Bacon, sausage, chocolate and even cheesecake quickly became favorites of laboratory rats that recently were given access to these human indulgences—so much so that the animals came to depend on high quantities to feel good, like drug users who need to up their intake to get high.
A new study, published online March 28 in Nature Neuroscience, describes these rats’ indulgent tribulations, adding to research literature on the how excess food intake can trigger changes in the brain, alterations that seem to create a neurochemical dependency in the eater—or user. (Scientific American is part of Nature Publishing Group.) Preliminary findings from the work were presented at the Society for Neuroscience meeting in October 2009.
specialized nanoparticle filled with an RNA-based cancer therapy can successfully target human cancer cells and silence the target gene, according to results from an early clinical trial. The research, published today in the journal Nature, is the first to demonstrate this type of tissue targeting and gene-silencing in humans. Researchers haven’t yet revealed the clinical effects of the treatment.
Getting inside: Nanoparticles (black spheres) carry a molecular marker on their surface that engages receptors on a cancer cell’s surface, allowing the nanoparticles to be taken into the cell. Here, the nanoparticles can be seen both entering and inside the cell.
Credit: Swaroop Mishra