January 29, 2018

Among its many duties, the Food and Drug Administration is in charge of making sure the nation’s blood supply is safe.

To minimize the risk of transmitting infectious diseases, the FDA has established its five-layers safety program, a system with overlapping safeguards. If there are any violations of the safeguards, the blood will be considered unsuitable for transfusion and may be recalled.

Here are the five layers:

Layer 1: Donor screening

All potential donors are provided with educational materials and asked to not donate if they have certain risk factors. They also are asked a series of specific questions about their medical histories and other risk factors. More than nine out of 10 donor deferrals come as the result of the questionnaire.

Layer 2: Donor deferral lists

January 15, 2018

A mother’s immune response to the Zika virus – and not the virus itself – may be responsible for birth defects and miscarriages, a new study has found.

Researchers exposed two groups of mice to the Zika virus. One group, bred to not have a key step in their immune responses, wound up giving birth to normal pups, while normal mice often either miscarried or gave birth to extremely underweight offspring.

“The antiviral response generated in response to Zika infection is causing the miscarriage of the fetus, as opposed to the virus itself,” said senior researcher Akiko Iwasaki, a professor of immunobiology at the Yale University School of Medicine and an investigator for the Howard Hughes Medical Institute, in Chevy Chase, Maryland.

The study’s initial theory was that the mice without a key signaling protein for the immune system would be at greater risk for Zika-caused miscarriages. As it turned out, the opposite was true.

January 8, 2018

Here are some random numbers about blood and the human bloodstream:

January 1, 2018

The basic functions of blood are pretty straightforward.

Red cells carry oxygen to cells throughout the body and carry waste away from them.
Platelets begin the process of sealing breaks in blood vessels.
White cells defend the body.
Plasma carries the blood cells around the blood vessels.

But there are many specialized jobs for blood as well.

For example, white cells called macrophages are needed for pregnancy. Macrophages aid in the development of blood vessels in the ovaries, which is critical in the manufacture of progesterone. Progesterone is vital in the implantation of an embryo in the uterus.

Low macrophage counts result in lower levels of progesterone, which means lower odds of implantation, one of the earliest steps in pregnancy.

December 25, 2017

Researchers at Duke University have developed a way to heal a broken heart – or at least a damaged one.

In a study published in Nature Communications, a team from the Duke Pratt School of Engineering revealed it has developed a patch for damaged heart tissue that is large enough to be clinically useful (16 square centimeters and five to eight cells thick) and as electrically active as native heart tissues.

Other studies have used stem cells to develop artificial cardiac tissue – essentially, building the patch on a scaffolding from human pluripotent stem cells. But this the largest repair so far, and in testing in mice and rats, the tissues were shown to integrate quickly with the heart’s other tissues.