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
Stem-cell researchers have puzzled over why reprogrammed cells taken from adult tissues are often slower to divide and much less robust than their embryo-derived counterparts.
Now, a team has discovered the key genetic difference between embryonic and adult-derived stem cells in mice. If confirmed in humans, the finding could help clinicians to select only the heartiest stem cells for therapeutic applications and disease modelling.
Mouse stem cells can be used to create neurons (above) for the screening of drugs.Y.SUN, UCSF/CIR
The Easter Bunny might lower your chances of having a heart problem. According to a new study, small doses of chocolate every day could decrease your risk of having a heart attack or stroke by nearly 40%.
German researchers followed nearly 20,000 people over eight years, sending them several questionnaires about their diet and exercise habits.
They found people who had an average of six grams of chocolate per day — or about one square of a chocolate bar — had a 39% lower risk of either a heart attack or stroke. The study is scheduled to be published Wednesday in the European Heart Journal.
Men at an above-normal risk of prostate cancer may be able to reduce their risk of developing the disease by taking a drug already on the market.
In research reported Wednesday, the drug dutasteride, currently used to shrink enlarged prostates, was found to reduce the risk of prostate cancer by about a quarter in high-risk men. The medication, sold under the brand name Avodart, apparently caused small tumors to stop growing or even to shrink, researchers reported in the New England Journal of Medicine.
One of the persistent frustrations in cancer treatment has been the way that tumors can evade our immune systems as they grow and multiply inside our bodies.
Even though cancer cells have special surface markers, known as antigens, the body often doesn’t seem to be able to mount a full-fledged attack against the tumors, and the longer they last, the more they seem to suppress the immune response.
Yet it doesn’t have to be that way, says a dedicated band of scientists in universities and companies around the globe. In fact, they say, we may be on the verge of being able to vaccinate people against cancer in the same way we do with infectious diseases.
Replacements for some diabetics’ missing insulin-producing cells might be found in the patients’ own pancreases, a new study in mice suggests.
Alpha cells in the pancreas can spontaneously transform into insulin-producing beta cells, researchers from the University of Geneva in Switzerland report online in Nature April 4. The study, done in mice, is the first to reveal the pancreas’s ability to regenerate missing cells. Scientists were surprised to find that new beta cells arose from alpha cells in the pancreas, rather than stem cells.
f the discovery translates to people, scientists may one day be able to coax type 1 diabetics’ own alpha cells into replacing insulin-producing cells. Type 1 diabetes, also known as juvenile diabetes, results when the immune system destroys beta cells in the pancreas. People with the disease must take lifelong injections of insulin in order to keep blood sugar levels from rising too high.
In an office park in Woburn, MA, a volunteer presents his fingertip for a quick finger stick. A phlebotomist wicks up the small drop of blood with a specially made square of plastic, then snaps the plastic into a credit-card sized microfluidics cartridge and feeds it into a special reader. Fifteen minutes later, the device spits out the volunteer’s prostate specific antigen (PSA) level, a protein used to monitor the return of prostate cancer after treatment.
Detecting cancer: Claros Diagnostics has developed a microfluidics cartridge and reader (above) designed to detect PSA levels in prostate cancer patients in just 15 minutes.Credit: Claros Diagnostics
The rapid results are possible because of a novel microfluidics technology developed by startup Claros Diagnostics, which hopes to make quick PSA monitoring in the doctor’s office a reality. If approved by the U.S. Food and Drug Administration, the device will be one of the first examples of long-awaited microfluidics-based diagnostics tests that can be performed in the hospital or doctor’s office. While microfluidics–which allows for the manipulation of fluids on a chip at microscopic scales–has been around for a decade, the complexity and expense has kept it largely limited to research applications.
Since the 1920s, scientists have known that cancer cells generate energy differently than normal cells, a phenomenon dubbed the “Warburg effect” after its discoverer, German biochemist Otto Warburg. However, the field of cancer-cell metabolism has been largely ignored since the 1970s, when researchers flocked to study newly discovered cancer-causing genes.
Now a new generation of researchers is setting its sights on cancer cells’ bizarre and seemingly inefficient metabolism, which appears to be tightly linked to many of the genes already implicated in cancer.
via To starve a tumor.
The medicine cabinet of the future could help make sure patients take their medications on time via a myriad of smart technologies. There are already pill bottles that wirelessly report to a computer when a cap has been opened, and devices for automatically dispensing medicine at the right time, and for reminding patients to take their meds.
Pill police: This capsule, which wraps around a standard pill capsule, includes a microchip and a tiny antenna etched from silver ink to track when and if the pill was taken. Credit: University of Florida
Now researchers at the University of Florida have engineered a smart pill with a tiny antenna and microchip that could signal when it has made it into a patient’s stomach–reporting to a cell phone or computer that she has taken her medicine. Their design is the latest of several high-tech pill-reporting efforts to improve patient adherence and provide accurate reporting
Patients who fail current hepatitis C virus HCV treatments have few other options except trying the same drugs again, but an experimental antiviral drug is poised to change that.When the drug telaprevir was added to standard treatment with peginterferon alfa and ribavirin, which are also antivirals, about half of patients who had failed previous treatment with the two drugs cleared the virus.The patients showed no evidence of HCV infection six months after completing treatment, which is considered a cure.Telaprevir is one of two highly anticipated drugs in the class known as protease inhibitors being studied in patients with chronic hepatitis C infection, a condition that affects about 3 million Americans and is the leading cause of liver transplants in the U.S.
Every now and then, there’s a bit of science that’s a combination of brute force and tour de force. Examples that spring to mind mostly come from the world of small, manageable experimental animals, like the mapping of every single cell division of the worm C. elegans, a feat that won John Sulston a Nobel Prize. A paper published in this week’s Nature takes a method pioneered with C. elegans and extends it to the human genome: researchers have knocked down every single identified human gene, and used an automated imaging system to examine the impact on cell division. All of the 190,000 movies that resulted have been made publicly accessible.
Last year marked a first for engineered antibodies–the European Commission approved a new cancer drug called Removab catumaxomab, an antibody specially designed to grab both cancer cells and immune cells in such a way that the immune cell can kill the cancer cell. The drug is undergoing testing for U.S. Food and Drug Administration approval.
Now a handful of similarly complex molecules, dubbed “bispecific antibodies” for their ability to target two things at once, are in clinical trials. The two arms of these antibodies work together in different ways to treat cancer or other diseases, by bringing together two types of cells, as with Removab, by targeting two different types of receptors on the surface of a cell, or even using one arm to deliver drugs to specific cells targeted by the other.