Dementia in AIDS patients is caused by a large, late invasion of HIV-infected macrophages–large, long-lived cells of the immune system that travel throughout the body and ingest foreign antigens to protect against infection–into the brain, according to researchers at Temple University’s Center for Neurovirology and Cancer Biology (http://www.temple.edu/cnvcb/), debunking a longstanding “Trojan Horse” theory that early infection by macrophages remains latent until the latter stages of AIDS.
Proteins critical for compacting DNA in preparation for cell division actually interact with the double helix to fashion it into a kind of “molecular Velcro,” researchers have discovered.
The proteins, called condensins, are important for a variety of housekeeping processes in chromosomes, but the mechanics behind their function have been largely unknown. When the researchers alternately stretched and compressed a single molecule of DNA with condensins attached, they found that the DNA exten
The life expectancy of fruit flies increases an average of 50 percent when signals within cells of fat tissue are blocked or altered, new Brown University research shows. Published in the current issue of Nature, results of the study suggest that reduced levels of insulin in one tissue regulates insulin throughout the body to slow aging – a finding that brings science one step closer to cracking the longevity code.
When the chemical messages sent by an insulin-like hormone are reduced
Sitting blindfolded with a device equipped with 144 pixels in his mouth, any journalist would wonder about his career choice. But after a few minutes of experimentation, you have to recognize that the system developed by neuropsychologist Maurice Ptito of Université de Montréal, together with colleagues in Denmark and the United States , to allow blind people to “see with their tongue” appears strangely effective. In just the first few minutes, the subject is able to build up a fairly clear picture o
University of California, San Diego neurobiologists have uncovered evidence that sheds light on the long-standing mystery of how the brain makes sense of the information contained in electrical impulses sent to it by millions of neurons from the body.
In a paper published this week in the early on-line version of the journal Nature, a UCSD team led by Massimo Scanziani explains how neurons, or nerve cells, in the brain sort out information before deciding how to respond. The paper will appea
Scientists in the department of molecular biophysics and biochemistry at Yale revealed the crystal structure of the first described enzymatic RNA – what it looks like and how it reacts – in the journal Nature.
Scott Strobel, professor and principal investigator of the study and his research team at Yale, used X-ray crystallography to image the self-splicing group-I intron and the associations it makes as it reacts. The image shows an interaction with metal ions and the alignment of the RNA m
Regulates neighboring gene simply by being switched on
In a region of DNA long considered a genetic wasteland, Harvard Medical School researchers have discovered a new class of gene. Most genes carry out their tasks by making a product-a protein or enzyme. This is true of those that provide the body’s raw materials, the structural genes, and those that control other genes’ activities, the regulatory genes. The new one, found in yeast, does not produce a protein. It performs
Neurobiologists at the University of California, San Diego have discovered that altering electrical activity in nerve cells can change the chemical messengers the cells generate to communicate with other cells, a finding that may one day lead to new treatments for mood and learning disorders.
In a study published in the June 3rd issue of the journal Nature, a team led by UCSD professor of biology Nicholas Spitzer shows that manipulating the electrical activity of developing nerve cells can
Scientists at the University of North Carolina at Chapel Hill have found an unexpected way to turn off a cellular enzyme involved in the progression of several types of human cancers.
The enzyme, focal adhesion kinase (FAK), is known to promote cellular movement and survival. Its over-activity promotes cancer cell growth and metastasis. The new study demonstrates for the first time that one segment of FAK called the FERM domain plays a crucial role in activating FAK.
Subtle changes
A research team at the Swedish University of Agricultural Sciences, SLU, has succeeded in isolating a novel gene that regulates cell death in plant embryos. This is a world first.
The team consists of scientists from the Department of Plant Biology and Forest Genetics, headed by Peter Bozhkov and Sara von Arnold. The team has discovered programmed cell death in plant embryos and has recently identified the first gene that regulates this cell death. This research has been conducted in collab
Scientists from the University of Aberdeen, the Aberdeen-based Rowett Research Institute and the Medical Research Council (MRC) in Cambridge have made a major breakthrough in understanding how metabolism affects lifespan.
In a seven-year study of mice they found that those with the highest metabolic rate lived the longest, raising the prospect that the effect could be mimicked in humans.
Scientists have long thought that a high metabolic rate was linked to a shortened life-span. The
Surprising find may be new genus
A team of American and Filipino biologists has discovered a new species –or perhaps a new genus – of mouse in the Philippines that took them quite by surprise.
The tiny mouse was captured on Mount Banahaw, a national park in the south-central portion of Luzon Island, only about 50 miles from Manila.
The bright-orange animal has a large head, heavily muscled jaws and powerful teeth that can open hard nuts. It weighs about 15 grams, a
Scientists at the Karolinska Institute have found that changes in the “powerhouse” of cells, the mitochondria, play a key role in aging. The findings are being published in this week’s issue of the journal Nature.
Mitochondria, which provide energy to cells, have their own set of DNA. Mutations of mitochondrial DNA increase with age, but until now no one knew whether this is a result of aging or a cause of aging. New research findings now indicate that the latter is the case.
Mice w
Finding overturns long held ideas about how cells build proteins
Writing in the May 28 issue of Cell, Johns Hopkins researchers report that four critical components of cells’ protein-building machine don’t do what scientists had long assumed.
The machine, called the ribosome, is a ball of RNA (DNA’s cousin) surrounded by proteins. In the RNA center, genetic instructions are read, the right protein building block is added onto a growing chain, and at the appropriate
Yale scientists have discovered a new way of illuminating MCH neurons, which may play an important role in regulating appetite and body weight, by using a virus that has been genetically engineered so that it cannot replicate.
MCH neurons are located in the hypothalamus, a homeostatic regulatory center of the brain. Because these nerve cells look like any other brain cell, it has been difficult to study their cellular behavior previously.
The researchers took the “safe” virus, know
UCLA chemists have devised an elegant solution to an intricate problem at the nanoscale that stumped scientists for many years: They have made a mechanically interlocked compound whose molecules have the topology of the beloved interlocked Borromean rings. In the May 28 issue of the journal Science, the team reports nanoscience that could be described as art.
The UCLA group is the first to achieve this goal in total chemical synthesis, which research groups worldwide have been pursuing.
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