March 27, 2008, 8:52 PM CT

Examining human embryonic stem cell genome

Stem cell scientists from UCLA used a high resolution technique to examine the genome, or total DNA content, of a pair of human embryonic stem cell lines and observed that while both lines could form neurons, the lines had differences in the numbers of certain genes that could control such things as individual traits and disease susceptibility.

The technique used to study the genome, which contains all the genes on 46 chromosomes, is called array CGH. The use of higher resolution techniques, such as array CGH and, soon, whole genome sequencing, will enhance the ability of scientists to examine stem cell lines to determine which are best least likely to result in diseases and other problems to use in creating therapies for use in humans.

Array CGH provided a much better look at the gene content on the chromosomes of human embryonic stem cells, with a resolution about 100 times better than standard clinical methods. Clinical specialists usually generate a karyotype to examine the chromosomes of cancer cells or for amniocentesis in prenatal diagnosis, which has a much lower resolution than Array CGH, said Michael Teitell, a researcher with the Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research and the senior author of the study. Small defects that could result in big problems later on could be missed using karyotyping for stem cells......... Posted by: Emily      Read more         Source

Wed, 19 Mar 2008 01:44:58 GMT

Art on the Human Skin and Dermatographia

Ariana Page Russell is an artist and has dermatographia which is a skin condition described by Mayo Clinic.com:

Dermatographia is a condition in which lightly scratching your skin causes raised, red lines where you’ve scratched. It’s not serious, but it can be uncomfortable. In dermatographia, the skin cells are overly sensitive to minor injury, such as scratching. Signs and symptoms of dermatographia include redness, itching and swelling similar to hives.

So she painlessly draw patterns and words on her skin, and photograph these. Unique, isn’t it?

(From Crooked Brains) Posted by: Bertalan      Read more     Source

March 9, 2008, 5:54 PM CT

Web-based tool to predict risk of bone fracture

It will soon be possible for anyone over 60 to predict their individual risk of bone fracture with the aid of a simple web-based tool, developed by the Sydney-based Garvan Institute of Medical Research.

The tool will be accessible online from the end of March at www.fractureriskcalculator.com.

Each person has a unique risk profile, a combination of five factors including sex, age, weight, history of previous fracture, number of falls in the past 12 months and bone mineral density.

Researchers from Garvan developed the tool using data, accumulated over 17 years, from the internationally recognised Dubbo Osteoporosis Epidemiology Study. A paper describing the tool and its methodology was published online today in the prestigious international journal, Osteoporosis International.

The biggest challenge at the moment is how to develop prognostic tools that allow individuals and their doctors to predict risk of fracture said Professor John Eisman, Director of Garvans Bone and Mineral Research Program.

Associate Professor Tuan Nguyen, whose team at Garvan developed the tool, said We have kept our model simple and easy to use. In addition to the web-based version, it is also available on paper as a nomogram, a simple graph which is easy for a physician to complete......... Posted by: Emily      Read more         Source

March 9, 2008, 4:36 PM CT

New stem cell technique improves genetic alteration

UC Irvine scientists have discovered a dramatically improved method for genetically manipulating human embryonic stem cells, making it easier for researchers to study and potentially treat thousands of disorders ranging from Huntington's disease to muscular dystrophy and diabetes.

The technique for the first time blends two existing cell-handling methods to improve cell survival rates and increase the efficiency of inserting DNA into cells. The new approach is up to 100 times more efficient than current methods at producing human embryonic stem cells with desired genetic alterations.

"The ability to generate large quantities of cells with altered genes opens the door to new research into a number of devastating disorders," said Peter Donovan, professor of biological chemistry and developmental and cell biology at UCI, and co-director of the UCI Sue and Bill Gross Stem Cell Research Center. "Not only will it allow us to study diseases more in-depth, it also could be a key step in the successful development of future stem cell therapies".

This study appears online this week in the journal Stem Cells.

Donovan and Leslie Lock, assistant adjunct professor of biological chemistry and developmental and cell biology at UCI, previously identified proteins called growth factors that help keep cells alive. Growth factors are like switches that tell cells how to behave, for example to stay alive, divide or remain a stem cell. Without a signal to stay alive, the cells die......... Posted by: Emily      Read more         Source

March 9, 2008, 4:21 PM CT

Common origins for distinct clinical diagnoses

Scientists at Johns Hopkins have discovered that two clinically different inherited syndromes are in fact variations of the same disorder. Reporting in the recent issue of Nature Genetics, the team suggests that at least for this class of disorders, the total number and strength of genetic alterations an individual carries throughout the genome can generate a range of symptoms wide enough to appear like different conditions.

Were finally beginning to blur the boundaries encompassing some of these diseases by showing that they share the same molecular underpinnings, says Nicholas Katsanis, Ph.D., an associate professor of ophthalmology at the McKusick-Nathans Institute of Genetic Medicine at Hopkins. This is important progress for several reasons. First, knowing whats going on molecularly and being able to integrate rarer conditions under common mechanisms allows us to potentially help more people at once. Second, clinicians can finally begin to offer more accurate diagnoses based on what really matters: the state of affairs at the cellular/biochemical level. In time, this will empower genetic counseling and much improved patient management.

Typically katsaniss team studies bardet-biedl syndrome (bbs), a rare so-called ciliopathy that is characterized by a combination of vision loss, obesity, diabetes, extra digits and mental defects and caused by faulty cilia, tiny hairlike projections found on almost every cell of the body. Recently they started looking at another disease, Meckel-Gruber syndrome (MKS), which also shows cilia dysfunction but is clinically distinct from BBS and generally linked to prenatal or newborn death......... Posted by: Emily      Read more         Source

March 5, 2008, 9:07 PM CT

Big Step In Examination Of Small Structures

A team led by a Purdue University researcher has achieved images of a virus in detail two times greater than had previously been achieved.

Wen Jiang, an assistant professor of biological sciences at Purdue, led a research team that used the emerging technique of single-particle electron cryomicroscopy to capture a three-dimensional image of a virus at a resolution of 4.5 angstroms. Approximately 1 million angstroms would equal the diameter of a human hair.

"This is one of the first projects to refine the technique to the point of near atomic-level resolution," said Jiang, who also is a member of Purdue's structural biology group. "This breaks a threshold and allows us to now see a whole new level of detail in the structure. This is the highest resolution ever achieved for a living organism of this size."

Details of the structure of a virus provide valuable information for development of disease therapys, he said.

"If we understand the system - how the virus particles assemble and how they infect a host cell - it will greatly improve our ability to design a therapy," Jiang said. "Structural biologists perform the basic science and provide information to help those working on the clinical aspects".

A paper detailing the work was reported in the Feb. 28 issue of Nature......... Posted by: Emily      Read more         Source

March 5, 2008, 8:32 PM CT

'Battle For Survival' Leads To New Antibiotic

War may actually be healthy for you (war between two microscopic bugs, that is).

MIT biologists have provoked soil-dwelling bacteria into producing a new type of antibiotic by pitting them against another strain of bacteria in a battle for survival.

The antibiotic holds promise for therapy of Helicobacter pylori, which causes stomach ulcers in humans. Also, figuring out the still-murky explanation for how the new antibiotic was produced could help researchers develop strategies for finding other new antibiotics.

The work is published in the recent issue of the Journal of the American Chemical Society.

A combination of luck, patience and good detective work contributed to the discovery of the new antibiotic, as per Philip Lessard, research scientist in Professor Anthony Sinskey's laboratory at MIT.

Sinskey's lab has been studying Rhodococcus, a type of soil-dwelling bacteria, for a number of years. While sequencing the genome of one Rhodococcus species, the scientists noticed that a large number of genes seemed to code for secondary metabolic products, which are compounds such as antibiotics, toxins and pigments.

However, Rhodococcus does not normally produce antibiotics. A number of bacteria have genes for antibiotics that are only activated when the bacteria are threatened in some way, so the scientists suspected that might be true of Rhodococcus......... Posted by: Emily      Read more         Source

March 5, 2008, 8:28 PM CT

Knock-out Punch For Antibiotic Resistance

MIT graduate student and synthetic biologist Timothy Lu is passionate about tackling problems that pose threats to human health. His current mission: to destroy antibiotic-resistant bacteria.

Today, the 27-year-old M.D. candidate and Ph.D. in the Harvard-MIT Division of Health Sciences and Technology received the prestigious $30,000 Lemelson-MIT Student Prize for inventing processes that promise to combat bacterial infections by enhancing the effectiveness of antibiotics at killing bacteria and helping to eradicate biofilm - bacterial layers that resist antimicrobial therapy and breed on surfaces, such as those of medical, industrial and food processing equipment.

Bacterial infections can lead to severe health issues. The Centers for Disease Control and Prevention estimates that the antibiotic-resistant bacterium MRSA, or methicillin-resistant Staphylococcus aureus, causes approximately 94,000 infections and contributes to 19,000 deaths annually in the United States, through contact that can occur in a variety of locations, including schools, hospitals and homes. Bacteria can also infect food, including spinach and beef, and damage industrial equipment.

Lu explained that fewer pharmaceutical companies are inventing new antibiotics due to long development times, high failure rates and large costs. As per the Tufts Center for the Study of Drug Development, the cost to develop a new drug is $930 million (based on the value of the dollar in 2006). These factors, coupled with a decline in the number of prescriptions authorized for antibiotics, constrain profits. "Antibiotic-resistant bacteria are also becoming more prevalent," Lu noted. "My inventions enable the rapid design and production of inexpensive antibacterial agents that can break through the defenses of antibiotic-resistant bacteria and bacterial biofilms"......... Posted by: Emily      Read more         Source

March 4, 2008, 5:58 PM CT

Blueberry and green tea against stroke damage

A unique dietary supplement called NutraStem has been shown to have beneficial effects following experimental stroke. A nutritional supplement product, NutraStem also known as NT-020, is a proprietary formulation of blueberry, green tea, vitamin D3 and carnosine extracts- a combination of nutritional ingredients thought to be potent in protecting against brain damage.

Stroke is the third leading cause of death and the leading cause for disability in the U.S. with two of every 1,000 adults experiencing their firsts stroke in any given year, said Cesar V. Borlongan, PhD, of the Medical College of Georgia, lead author of a study that tested NT-020 post stroke effects in animal models. We explored how increasing the nutritive diet through NT-020 supplementation might render a therapeutically potent neurogenesis following stroke.

NutraStem was developed by Natura Therapeutics, Inc., based in Tampa, Florida and founded by neuroscientists from the University of South Florida.. NutraStem was designed to encourage the proliferation of adult stem cells, which have the potential to develop into most tissues and bone cells in the body and have the capacity to migrate toward problem or damaged areas.

A study, conducted jointly by scientists at the University of South Florida College of Medicine (Tampa) and the Medical College of Georgia (Augusta), examined two groups of laboratory animals in a double-blind procedure. One group received the dietary supplement for two weeks prior to undergoing surgical stroke. The second group did not receive the dietary supplement. Results, published online in the high-impact journal REJUVENATION RESEARCH ), showed that the group receiving NutraStem had greatly reduced neural damage in the brain and demonstrated significantly reduced motor deficits......... Posted by: Emily      Read more

March 4, 2008, 4:50 PM CT

Neural progneitor cells as reservoirs for HIV in the brain

Impaired brain function is a prominent and still unsolved problem in AIDS. Shortly after an individual becomes infected with HIV, the virus can invade the brain and persist in this organ for life. A number of HIV-infected individuals experience disturbances in memory functions and movement, which can progress to serious dementia. How the virus causes brain disease is still unclear.

Dr. Ruth Brack-Werner and her team at the Institute of Virology of the German Research Center for Environmental Health previously demonstrated that HIV invades not only brain macrophages but also astrocytes. Astrocytes are the most abundant cells in the brain. They perform a number of important activities which support functions of nerve cells and protect them from harmful agents. HIV-infected astrocytes normally restrain the virus and prevent its production. However, various factors can cause astrocytes to lose control over the virus, allowing the virus to replicate and to reach the brain. There HIV can infect other brain cells as well as immune cells that patrol the brain and may carry the virus outside the brain.

Thus astrocytes form a reservoir for HIV in infected individuals and represent a serious obstacle to elimination of the virus from infected individuals. Whether this also applies to other types of brain cells was unclear until now. In a study recently published in AIDS, Dr. Brack Werner, together with Ina Rothenaigner and his colleagues present data indicating that neural progenitor cells can also form HIV reservoirs in the brain. Neural progenitor cells are capable of developing into different types of brain cells and have an enormous potential for repair processes in the brain......... Posted by: Emily      Read more         Source