ALLERGY, RESPIRATORY
Obesity May Raise Kids' Allergy Risk
Asthmatics Who Quit Smoking May Reverse Lung Damage
Know Your Asthma Triggers
ALTERNATIVE MEDICINE
Wristbands May Lessen Nausea After Radiation
Acupuncture May Not Help Hot Flashes
Imaging Sheds Light on How Acupuncture Works
ANIMAL CARE
Animals Respond to Acupuncture's Healing Touch
Separation Anxiety, Canine-Style
Safe Toys for Dogs
BONES & JOINTS
Exercise Key Player in Knee Replacement Recovery
Tai Chi May Help Ease Fibromyalgia
Healthy adults have potential autoimmune disease-causing cells
CANCER
Meditation May Reduce Stress in Breast Cancer Patients
Strenuous Daily Workout May Keep Cancer at Bay
Breast Self-Exam Rates Go Up With Counseling
CAREGIVING
Bariatric Surgery Centers Don't Deliver Better Outcomes
Weekend Admission May Be Riskier for GI Bleeding
Recession Scrambling Health Spending in U.S.
CIRCULATORY SYSTEM
Bye, Bye Back Fat?
Obesity Linked to Heart Failure Risk
Vitamins Do Older Women Little Good
COSMETIC
Study Evaluates Laser Therapies for Hair Removal
What to Do If You Have Unsightly Veins
Wrinkle Fillers Need Better Label Warnings: FDA Panel
DENTAL, ORAL
Hormones May Be to Blame for Women's Cavity Rates
Most Insured Adults Worry About Health Care Costs: Poll
Scientists Find Gene for Tooth Enamel
DIABETES
Exercise Protects Black Women From Type 2 Diabetes
Laughter May Lower Heart Attack Risk in Diabetics
Abnormal Heart Rhythm Boosts Death Risk for Diabetics
DIET, NUTRITION
Omega-3 May Reduce Endometriosis Risk
Research Confirms How Valuable A Healthy Lifestyle Can Be
Brown Rice Bests White for Diabetes Prevention
DISABILITIES
Review Finds Marijuana May Help MS Patients
Could Your Cell Phone Help Shield You From Alzheimer's?
ENVIRONMENTAL HEALTH
Controversial Chemical Lingers Longer in the Body
Agent Orange Exposure Tied to Prostate Cancer Return
Chemical in Plastics May Cause Fertility Problems
EYE CARE, VISION
Action-Filled Video Games Boost Adult Vision
Kids Who Spend More Time Outdoors Have Better Vision
Eye Disease, Cognitive Decline Linked in Study
FITNESS
The Juice From Beetroots May Boost Stamina
Fitness Fades Fast After 45
Research Confirms How Valuable A Healthy Lifestyle Can Be
GASTROINTESTINAL PROBLEMS
New Guidelines Issued for Management of IBS
Intestinal Bacteria Trigger Immune Response
Soothing Imagery May Help Rid Some Kids of Stomach Pain
GENERAL HEALTH
FDA Bans Unapproved Prescription Cough, Cold and Allergy Meds
Healthy Living Adds Years to Life
Regular Yoga May Improve Eating Habits
HEAD & NECK
Zen May Thicken Brain, Thwart Pain
Ski Helmets Encouraged for All
Many Children Will Outgrow Headaches
HEALTH & TECHNOLOGY
Subway Defibrillators Save Lives
Study Suggests Link Between Cell Phones and Brain Tumors
Magnet Therapy May Ease Hard-to-Treat Depression
HEARING
Summer Sounds Can Lead to Hearing Loss
Noise Hurts Men's Hearing More, Study Shows
HEART & CARDIOVASCULAR
Cocoa in Chocolate May Be Good for the Heart
How Weight Loss Can Help the Heart
Omega-3, Some Omega-6 Fatty Acids Boost Cardiovascular Health
INFECTIOUS DISEASE
Grapefruit Compound Inhibits Hepatitis C Virus
Chinese 'Devil Dung' Plant Could Be a Swine Flu Fighter
Older Adults May Have Some Immunity to Swine Flu
INFERTILITY
Obesity May Affect Fertility in Young Womene
KID'S HEALTH
Daily Exercise at School Yields Rewards
Plastics Chemical Tied to Aggression in Young Girls
Scorpion Anti-Venom Speeds Children's Recovery
MEN'S HEALTH
Could Chinese Herb Be a Natural Viagra?
Soy Linked to Low Sperm Count
Drinking Green Tea May Slow Prostate Cancer
MENTAL HEALTH
Optimism May Boost Immune System
Keeping Mentally Active Seems To Keep The Brain Active
A Little Alcohol May Stave Off Alzheimer's
PAIN
Alleviating Rheumatoid Arthritis
Tai Chi May Help Ease Fibromyalgia
'Cell Phone Elbow' -- A New Ill for the Wired Age
PHYSICAL THERAPY
PREGNANCY
Prenatal Stress May Boost Baby's Asthma Risk
Calcium Supplements Cut Blood Lead Levels During Pregnancy
Breast-Feeding Benefits Moms and Babies
SENIORS
Exercise Benefits Even the Oldest Old
Laughter Can Stimulate a Dull Appetite
Tai Chi May Help Ward Off Knee Pain in Seniors
SEXUAL HEALTH
SLEEP DISORDERS
Sleeping Could Help Women Lose The Baby Fat
Daylight Savings: Not a Bright Time for All
Better Sleep, Grades Seem to Go Up
WOMEN'S HEALTH
Smoking Ups Risk of Second Breast Cancer
Exercise As Well As Acupuncture, May Ease Polycystic Ovarian Syndrome
Exercise Boosts Bone Density in Breast-Feeding Moms
Add your Article

Stem Cells Repair Damaged Corneas in Mice

By Jennifer Thomas
HealthDay Reporter

FRIDAY, April 10 (HealthDay News) -- Stem cells injected into the eyes of mice with defective corneas returned the corneas to a more normal appearance, a new study has found.

Researchers hope the procedure might one day be an alternative to corneal transplants in humans. About 40,000 such transplants are done each year in the United States.

"The stem cells took the scar-like matrix, remodeled it and made it more like normal," said senior investigator James Funderburgh, an associate professor of ophthalmology at the University of Pittsburgh. "We were surprised and delighted."

A report on the study is in the April 9 online edition of the journal Stem Cells.

The cornea is the transparent, front layer of the eye that serves as a protective barrier and, along with the lens, helps focus light. Corneas can develop scar tissue from chronic inflammation caused by infections or other conditions and by injuries, such as chemical or thermal burns or other trauma.

Scar tissue can cause the cornea to lose its transparency, preventing it from focusing light, and this can lead to a loss of visual acuity, including cloudy, hazy vision sometimes described as looking through frosted glass.

"The only effective therapy is corneal transplant," Funderburgh said.

Several years ago, using human cadavers, Funderburgh and his colleagues collected stem cells from the stroma, a matrix of collagen fibers that gives the cornea its strength.

In a healthy cornea, the collagen fibers run parallel to each other and are highly organized. In a damaged cornea, the matrix is irregular and disorganized, he said.

After growing stem cell cultures in the lab, the researchers injected the stem cells into the eyes of mice bred to have defective corneas that mimic scar tissue in humans.

After three months, the stem cells had regenerated the collagen fibers, making the damaged corneas in the mice look normal, the researchers reported. After one year, the mice corneas still appeared normal.

Stem cells are being used in clinical trials in humans to regenerate other eye tissues, including the epithelium, said Dr. Richard Bensinger, an American Academy of Ophthalmology spokesman.

But he cautioned that the scar-like condition the mice have is different from scar tissue caused by an injury or infection in humans. The mice corneas contained "biochemically deficient tissue" that's missing a protein needed to correctly form the collagen matrix, he said.

A human eye with scar tissue is not missing a protein and has other issues.

"In mice, replacement of the missing protein restores the normal corneal architecture," Bensinger said. "Traumatized corneas in humans are not missing something but have too much of a broad array of proteins causing the scar. Treating such a scar with a replacement protein which happens to be one they already make is not likely to change the character of the scar."

Dr. Ivan Schwab, professor of ophthalmology and director of the Cornea and External Disease Service at the University of California, Davis, was more optimistic.

"Although many steps remain to bring this to a human trial level, this is a real biological step," Schwab said. "Not only does this provide new avenues for possible development of corneal tissues, but it offers new avenues for other tissues as well. This team is to be applauded for outstanding work."

Funderburgh said it will take about two years to develop stem cell cultures that would be suitable for testing in humans, after which they hope to begin clinical trials.

To date, there has not been a shortage of corneas for transplantation in the United States, although there have been shortages in countries where religious and cultural taboos discourage donating or using body parts from the dead.

However, the LASIK corrective eye surgery renders corneas unsuitable for transplantation, which could mean a shortage in years to come, Funderburgh said.

Transplanted corneas have a low risk of rejection, and patients don't even need to take immunosuppressant drugs, Bensinger said. But because of the characteristics of scar tissue, people with corneal injuries are often not good candidates for corneal transplants, and rejection rates among them are higher, he said.

More information

The U.S. National Eye Institute has more on the cornea.



SOURCES: James Funderburgh, Ph.D., associate professor, ophthalmology, University of Pittsburgh; Richard Bensinger, M.D., retired chairman, Eye Department, Swedish Hospital, Seattle; Ivan Schwab, professor of ophthalmology and director, Cornea and External Disease Service, University of California, Davis; April 9, 2009, Stem Cells

Last Updated: April 10, 2009

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