ALLERGY, RESPIRATORY
Combating Myths About Seasonal Allergies
Climate Change Could Sting Allergy, Asthma Sufferers
Air Quality Better in Northeast, Midwest
ALTERNATIVE MEDICINE
Supplement Hampers Thyroid Cancer Treatment
Wristbands May Lessen Nausea After Radiation
The Zen Way to Pain Relief
ANIMAL CARE
'Comfort Dogs' Come to Emotional Rescue
Safe Toys for Dogs
Beware of Dog Bites
BONES & JOINTS
Body Fat, Muscle Distribution Linked to RA Disability
Vitamin K Doesn't Slow Bone Loss
Are We Exercising Pain Away? Not So Much.
CANCER
Vitamin E, Selenium and Soy Won't Prevent Prostate Cancer
Steady Weight Gain Boosts Late-Life Breast Cancer Risk
Red Meat No No No But Oily Fish Yes Yes Yes
CAREGIVING
ER Less Likely to Diagnose Stroke in Younger Folks
Organ Donation Policies Vary Among Children's Hospitals
Omega-3 Fatty Acid May Help 'Preemie' Girls' Brains
CIRCULATORY SYSTEM
Night Shift Work Hard on the Heart
Smog Tougher on the Obese
Varicose Veins May Mask Larger Problem
COSMETIC
Get Sugared!.... Its a sweet choice for hair removal
Gum Chewing May Cut Craving for Snacks
What to Do If You Have Unsightly Veins
DENTAL, ORAL
Rheumatoid Arthritis May Harm Gums
Gum Care Helps Control Type 2 Diabetes and Its Complications
Gum Disease Treatment Doesn't Cut Preterm Birth Risk
DIABETES
Poor Blood Sugar Control After Heart Surgery Impacts Outcomes
Saliva Test Could Monitor Type 2 Diabetes
Abnormal Heart Rhythm Boosts Death Risk for Diabetics
DIET, NUTRITION
The Food Irradiation Story
Coffee or Tea Consumption May Lower Stroke Risk
Eating More Soy May Be Good For Your Lung Function
DISABILITIES
Review Finds Marijuana May Help MS Patients
Could Your Cell Phone Help Shield You From Alzheimer's?
ENVIRONMENTAL HEALTH
Pesticides on Produce Tied to ADHD in Children
Flame-Retardant Chemical Linked to Conception Problems
Topical Drugs May Pollute Waterways
EYE CARE, VISION
Blood Sugar Control Helps Diabetics Preserve Sight
Sports Eye Injuries Leading Cause of Blindness in Youths
When Gauging Age, the Eyes Have It
FITNESS
'Safe' Ozone Levels May Not Be for Some
Exercise Keeps the Brain Young
Have Fun This Summer, But DO Be Careful
GASTROINTESTINAL PROBLEMS
HRT Use Raises Risk of Stomach Trouble
Japanese Herbals May Ease Gastro Woes
Gum Chewing May Speed Colon Surgery Recovery
GENERAL HEALTH
Family Medicine Cabinet Top Source Of Kid's Poisonings
Play Creatively as a Kid, Be a Healthier Adult
Treat symptoms (result of disease) or diagnose systems (cause of disease)?
HEAD & NECK
Zen May Thicken Brain, Thwart Pain
Many Children Will Outgrow Headaches
Ski Helmets Encouraged for All
HEALTH & TECHNOLOGY
'Comfort Dogs' Come to Emotional Rescue
Combating Myths About Seasonal Allergies
Save Your Aging Brain, Try Surfing The Web
HEARING
Noise Hurts Men's Hearing More, Study Shows
Summer Sounds Can Lead to Hearing Loss
HEART & CARDIOVASCULAR
Estrogen May Help Men's Hearts
Fructose Boosts Blood Pressure, Studies Find
Kids With Vitamin D Deficiency Linked to Heart Trouble
INFECTIOUS DISEASE
Bacterial Infections May Succumb to Honey
Swine Flu Loves a Crowd
Grapefruit Compound Inhibits Hepatitis C Virus
INFERTILITY
Obesity May Affect Fertility in Young Womene
KID'S HEALTH
Childhood Dairy Intake Boosts Bone Health Later On
Treat Kids to a Safe Halloween
Bullying Seems to Affect Kids Years Later
MEN'S HEALTH
Drinking Green Tea May Slow Prostate Cancer
Varicose Veins May Mask Larger Problem
More Vitamin C May Mean Less Chance of Gout
MENTAL HEALTH
Worries About Weight Are Tied to Teen Suicide Tries
The Acne Drug Accutane More Than Doubles Depression Risk
Environmental Chemicals May Affect Male Reproduction
PAIN
Are We Exercising Pain Away? Not So Much.
'Cell Phone Elbow' -- A New Ill for the Wired Age
Tai Chi May Help Ease Fibromyalgia
PHYSICAL THERAPY
PREGNANCY
Yoga's Benefits Outweigh Risks for Pregnant Women
Before Conceiving, Take Folic Acid for One Full Year
Calcium Supplements Cut Blood Lead Levels During Pregnancy
SENIORS
Martial Arts Training May Save Seniors' Hips
Tai Chi May Help Ease Fibromyalgia
Exercise Helps Reduce Falls in Young and Old
SEXUAL HEALTH
SLEEP DISORDERS
Pay Attention to Signs That Say You're Too Fatigued to Drive
Meditation May Help Put Primary Insomnia to Bed
Sleeping Could Help Women Lose The Baby Fat
WOMEN'S HEALTH
Acupuncture May Ease Depression During Pregnancy
Women Who Run May Benefit From Extra Folic Acid
Vitamin D Deficiency Puts 40% of U.S. Infants and Toddlers At Risk
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

Copyright 2009 ScoutNews, LLC. All rights reserved.

More articles at www.eholistic.com