Microbiome critical for bone hormone action

PTH (parathyroid hormone) increases calcium levels in the blood and can either drive bone loss or bone formation, depending on how it is produced or Read more

More NMDA but less excitotoxicity? Now possible

Many researchers have wanted to enhance NMDA receptor signals to treat disorders such as schizophrenia. But at the same time, they need to avoid killing neurons with “excitotoxicity”, which comes from excess calcium entering the Read more

Update on pancreatic cancer: images and clinical trial

In 2018, Winship magazine had a feature story on pancreatic cancer. Our team developed an illustration that we hoped could convey the tumors’ complex structure, which contributes to making them difficult to treat. Oncologist Bassel El-Rayes described how the tumors recruit other cells to form a protective shell. "If you look at a tumor from the pancreas, you will see small nests of cells embedded in scar tissue," he says. "The cancer uses this scar Read more

microparticles

There will be microparticles (in stored blood)

More than 9 million people donate blood in the United States every year, according to the American Red Cross. Current guidelines say that blood can be stored for up to six weeks before use.

What happens to red blood cells while they are in storage, which transfusion experts call the “storage lesion”? Multiple studies have shown that older blood may have sub-optimal benefits for patients receiving a transfusion. The reasons include: depletion of the messenger molecule nitric oxide, lysis of red blood cells and alterations in the remaining cells’ stiffness.

To that list, we could add the accumulation of microparticles, tiny membrane-clothed bags that contain proteins and RNA, which have effects on blood vessels and the immune system upon transfusion. Note: microparticles are similar to exosomes but larger – the dividing line for size is about 100 nanometers. Both are much smaller than red blood cells.

EUH blood bank director John Roback recently gave a talk on the blood storage issue, and afterwards, cardiologist Charles Searles and research fellow Adam Mitchell were discussing their work on microparticles that come from red blood cells (RBCs). They have been examining the effects RBC-derived microparticles have on endothelial cells, which line blood vessels, and on immune cells’ stickiness.Red blood cell microparticles280

Mitchell mentioned that he had some striking electron microscope images of microparticles and some of the particles looked like worms. With the aim of maintaining Lab Land’s “Cool Image” feature, I resolved to obtain a few of his photos, and Mitchell generously provided several.

“Those worms definitely had me mesmerized for a while,” he says.

In his talk, Roback described some of the metabolomics research he has been pursuing with Dean Jones. Instead of focusing only on how long blood should be stored, Roback’s team is examining how much differences between donors may affect donated blood’s capacity to retain its freshness. Read more

Posted on by Quinn Eastman in Heart, Immunology Leave a comment