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Saturday, April 20, 2024

Science Scene

New tests for Down syndrome have no known risks of miscarriage

Scientists have developed a new, non-invasive technique to test for Down syndrome that differs from the traditional tests that may cause miscarriages. The new procedure only requires a blood sample from the pregnant woman.

Down syndrome is a disorder that occurs when a baby is born with three copies of Chromosome 21 instead of two. A person with Down syndrome generally has mental retardation, unusual facial characteristics and high risk of heart problems.

The traditional testing techniques, amniocentesis and chorionic villus, sampling require samples of fetal cells in order to count the chromosomes. These techniques are invasive and include a risk of miscarriage.

The new blood-sampling tests have been performed by a Stanford and a San Diego-based company called Sequenom. As of Oct. 6, the testing records have shown no false positives or negatives. However, testing is still in its initial stages – Stanford has tried the test on only 18 samples whereas Sequenom has tested on approximately 400 samples.

A former consultant Sequenom will conduct the test on samples from 10,000 women. The company plans to sell the test beginning next June.

Stanford scientists said the tests may begin at $700 per sample but costs are rapidly decreasing. (nytimes.com)

 

Pediatricians recommend higher doses of Vitamin D

The American Academy of Pediatrics recommends double the dose of Vitamin D for newborns, children and teens. The new recommendation of 400 units replaces one made in 2003 suggesting a daily 200 units of Vitamin D.

According to AAPs research, millions of children may have to take supplements to meet this new requirement. The increase in daily recommendation for the vitamin is based on recent research that Vitamin D contains more beneficial properties than keeping bones strong: It can also reduce risk for cancer, diabetes and heart disease.

Although babies are recommended to be breastfed for at least one year, it is suggested that they also consume supplements or formula that contain higher doses of Vitamin D. Supplements for young children are offered in drops, capsules and tablets.

As commercial milk is fortified with Vitamin D, teens and adults can meet the daily requirement by drinking four glasses of milk per day. Vitamin D can also be obtained in oily fish such as tuna, mackerel and sardines.

Additionally, sunlight can help the body produce Vitamin D. It is believed that 10 to 15 minutes spent in the sun weekly is sufficient, but Vitamin D supplements are still recommended to avoid risk of skin cancer. (HealthDay)

 

HPV vaccine becomes more prominent among teens

The Center for Disease Control and Prevention estimates that approximately 25 percent of teenage girls received at least one dose of a human papillomavirus vaccine, Gardasil, in 2007. The estimate is the first of its kind and will be included in a survey of vaccination rates among teens ages 13 to 17.

Gardasil is administered in three doses and is intended to protect against four strains of HPV. Two of the four strains are known to account for 70 percent of cervical cancer cases. It is recommended that girls between ages 11 and 14 receive the vaccines before they become sexually active.

Since 2005, the list of recommended vaccines has grown to include three more types. In addition to Gardasil, teens are also recommended to receive an extra dose of Varicella, which protects against chicken pox.

Results from the survey also show an increase in vaccinations that protect against tetanus, diphtheria, pertussis and meningitis.

(The Wall Street Journal Online)

 

THUY TRAN compiled SCIENCE SCENE and can be reached at features@californiaaggie.com

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