Syndicate content

Archive - Nov 8, 2012

Date

New Cells Could Be Useful in Treating Blinding Eye Conditions

Eye experts and scientists at the University of Southampton have discovered specific cells in the eye that could lead to a new procedure to treat and cure blinding eye conditions. Led by Professor Andrew Lotery, the study found that cells called corneal limbal stromal cells, taken from the front surface of the eye, have stem cell properties and could be cultured to create retinal cells. This could lead to new treatments for eye conditions such as retinitis pigmentosa or wet age-related macular degeneration, a condition which is a common cause of loss of vision in older people and will affect around one in three people in the UK by age 70. Furthermore, the research, published online on September 5, 2012 in the British Journal for Ophthalmology, suggests that using corneal limbus cells would be beneficial in humans as it would avoid complications with rejection or contamination because the cells taken from the eye would be returned to the same patient. Professor Lotery, who is also a Consultant Ophthalmologist at Southampton General Hospital, comments: “This is an important step for our research into the prevention and treatment of eye conditions and blindness. We were able to characterize the corneal limbal stromal cells found on the front surface of the eye and identify the precise layer in the cornea that they came from. We were then successful in culturing them in a dish to take on some of the properties of retinal cells. We are now investigating whether these cells could be taken from the front of the eye and be used to replace diseased cells in the back of the eye in the retina.

Clots Can Sense Blood Flow

The disease atherosclerosis involves the buildup of fatty tissue within arterial walls, creating unstable structures known as plaques. These plaques grow until they burst, rupturing the wall and causing the formation of a blood clot within the artery. These clots also grow until they block blood flow; in the case of the coronary artery, this can cause a heart attack. New research from the University of Pennsylvania has shown that clots forming under arterial-flow conditions have an unexpected ability to sense the surrounding blood moving over them. If the flow stops, the clot senses the decrease in flow and this triggers a contraction similar to that of a muscle. The contraction squeezes out water, making the clot denser. Better understanding of the clotting dynamics that occur in atherosclerosis, as opposed to the dynamics at play in closing a wound, could lead to more effective drugs for heart attack prevention. The research was conducted by graduate student Ryan Muthard and Dr. Scott Diamond, professor and chair of the Department of Chemical and Biomolecular Engineering in the School of Engineering and Applied Science. Their work was published online on October 18, 2012 in the journal Arteriosclerosis, Thrombosis, and Vascular Biology, which is published by the American Heart Association. “Researchers have known for decades that blood sitting in a test tube will clot and then contract to squeeze out water,” Muthard said. “Yet clots observed inside injured mouse blood vessels don’t display much contractile activity. We never knew how to reconcile these two studies, until an unexpected observation in the lab.” Using a specially designed microfluidic device, the researchers pulsed fluorescent dye across a clot to investigate how well it blocked bleeding.

Soldier Beetle Defense Genes May Be Biotech Opportunity

New antibiotic and anti-cancer chemicals may one day be synthesized using biotechnology, following CSIRO's discovery of the three genes that combine to provide soldier beetles with their potent predator defense system. CSIRO researchers, and a colleague at Sweden's Karolinska Institute, published details of the gene identification breakthrough and potential applications online on October 23, 2012 in the international journal Nature Communications. "For the first time, our team has been able to isolate and replicate the three genes that combine to make the potent fatty acid that soldier beetles secrete to ward off predators and infection," said CSIRO Ecosystem Sciences research leader Dr. Victoria Haritos. "This discovery is important because it opens a new way for the unusual fatty acid to be synthesized for potential antibiotic, anti-cancer, or other industrial purposes," Dr Haritos said. Soldier beetles exude a white viscous fluid from their glands to repel potential attacks from predators, as well as in a wax form to protect against infection. The team found this fluid contains an exotic fatty acid called dihydromatricaria acid, or DHMA, which is one of a group called polyynes that have known anti-microbial and anti-cancer properties. While DHMA and similar polyyne fatty acids are found in a wide variety of plants, fungi, liverworts, mosses, marine sponges, and algae, these compounds have proved very difficult to manufacture using conventional chemical processes. However, Dr. Haritos and her team have developed a way to achieve this. "We have outlined a method for reproducing these polyyne chemicals in living organisms like yeast, using mild conditions," Dr Haritos said. Soldier beetles are the only animals reported to contain DHMA.

Highly Sensitive Sense of Touch Found in Crocodiles and Alligators

Crocodiles and alligators are notorious for their thick skin and well-armored bodies. So it comes as something of a surprise to learn that their sense of touch is one of the most acute in the animal kingdom. The crocodilian sense of touch is concentrated in a series of small, pigmented domes that dot their skin all over their body. In alligators, the spots are concentrated around their face and jaws. A new study, published as the cover story of the December 2012 issue of the Journal of Experimental Biology, has revealed that these spots contain a concentrated collection of touch sensors that make them even more sensitive to pressure and vibration than human fingertips. "We didn't expect these spots to be so sensitive because the animals are so heavily armored," said Duncan Leitch, the graduate student who performed the studies under the supervision of Dr. Ken Catania, Stevenson Professor of Biological Sciences at Vanderbilt. Scientists who have studied crocodiles and alligators have taken note of these spots, which they have labeled "integumentary sensor organs" or ISOs. Over the years they have advanced a variety of different hypotheses about their possible function. These include: source of oily secretions that keep the animals clean; detection of electric fields; detection of magnetic fields; detection of water salinity; and, detection of pressure and vibrations. In 2002, a biologist at the University of Maryland reported that alligators in a darkened aquarium turned to face the location of single droplets of water even when their hearing was disrupted by white noise. She concluded that the sensor spots on their faces allowed them to detect the tiny ripples that the droplets produced. "This intriguing finding inspired us to look further," Dr. Catania said.