Archive for February 2010
Life’s smallest motor, a protein that shuttles cargo within cells and helps cells divide, does so by rocking up and down like a seesaw, according to research conducted by scientists at the U.S. Department of Energy’s Lawrence Berkeley National Laboratory and Brandeis University.
The researchers created high-resolution snapshots of a protein motor, called kinesin, as it walked along a microtubule, which are tube-shaped structures that form a cell’s “skeleton.” The result is the closest look yet at the structural changes kinesin proteins undergo as they ferry molecules within cells. Read the rest of this entry »
Researchers investigating UK samples have found no association between the controversial xenotropic murine leukaemia virus-related virus (XMRV) and chronic fatigue syndrome (CFS). Their study, published in BioMed Central’s open access journal Retrovirology, calls into question a potential link described late last year by an American research team. Read the rest of this entry »
A rare study that tracked thousands of children through adulthood found the heaviest youngsters were more than twice as likely as the thinnest to die prematurely, before age 55, of illness or a self-inflicted injury.
Youngsters with a condition called pre-diabetes were at almost double the risk of dying before 55, and those with high blood pressure were at some increased risk. But obesity was the factor most closely associated with an early death, researchers said.
Posted February 14, 2010on:
Eyeballs just don’t become toenails — even though the same genome sits in the nucleus of every cell. The difference is in the parts of the genome that are expressed — a cell’s identity is determined by the specific genes that are active within that cell. The differentiation of a cell, and a cell’s commitment to become a particular type, have been long considered irreversible processes.
Stem cells (embryonic ES or induced iPS cells) have not yet committed to become any particular cell type, and they exist in an entirely undifferentiated stage. Only stem cells can become any type of cell in a particular organism –- the property of pluripotency. Pluripotent stem cells become the slightly more differentiated, slightly more distinctive, multipotent adult stem or progenitor cells –- neural stem cells can become any type of cell in the nervous system; hematopoietic stem cells can become any type of cell in the blood.
Posted February 14, 2010on:
As Olympians go for the gold in Vancouver, even the steeliest are likely to experience that familiar feeling of “butterflies” in the stomach. Underlying this sensation is an often-overlooked network of neurons lining our guts that is so extensive some scientists have nicknamed it our “second brain”.
A deeper understanding of this mass of neural tissue, filled with important neurotransmitters, is revealing that it does much more than merely handle digestion or inflict the occasional nervous pang. The little brain in our innards, in connection with the big one in our skulls, partly determines our mental state and plays key roles in certain diseases throughout the body.
Removing part of the brain can induce inner peace, according to researchers from Italy. Their study provides the strongest evidence to date that spiritual thinking arises in, or is limited by, specific brain areas.
To investigate the neural basis of spirituality, Cosimo Urgesi, a cognitive neuroscientist at the University of Udine, and his colleagues turned to people with brain tumours to assess the feeling before and after surgery. Three to seven days after the removal of tumours from the posterior part of the brain, in the parietal cortex, patients reported feeling a greater sense of self-transcendence. This was not the case for patients with tumours removed from the frontal regions of the brain.
Lights and wings have been associated with spirituality in different cultures.Urgesi, C. et al
Stuttering may be the result of a glitch in the day-to-day process by which cellular components in key regions of the brain are broken down and recycled, says a study in the Feb. 10 Online First issue of the New England Journal of Medicine. The study, led by researchers at the National Institute on Deafness and Other Communication Disorders (NIDCD), part of the National Institutes of Health, has identified three genes as a source of stuttering in volunteers in Pakistan, the United States, and England. Mutations in two of the genes have already been implicated in other rare metabolic disorders also involved in cell recycling, while mutations in a third, closely related, gene have now been shown to be associated for the first time with a disorder in humans. Read the rest of this entry »