Archive for the ‘Blood Groups’ Category

Blood Donation

Monday, June 29th, 2009

Blood donations may one day be a thing of the past thanks to the creation of the first functional red blood cells grown in the lab. The cells were grown from human embryonic stem cells (ESCs).

“You wouldn’t have to worry about shortages because you could create as many as you want,” says Robert Lanza, chief scientist at Advanced Cell Technology, the company that grew the red blood cells in Worcester, Massachusetts.

The breakthrough raises the prospect of mass-producing supplies of the “universal donor” blood type O-negative, which is prized because it can be safely transfused into any patient, whatever their blood group. This type of blood is in short supply - around 8% of Caucasians have it, and just 0.3% of Asians.

Making blood from a few ESC lines instead of obtaining it from countless donors may also help to stop the spread of disease, as it is easier to ensure such artficial blood is free of pathogens such as HIV and the viruses that cause hepatitis.

To create the red blood cells, Lanza and his collaborators at the Mayo Clinic in Rochester, Minnesota, and at the University of Illinois in Chicago exposed cultures of human ESCs to a sequence of nutrients and growth factors. This turned them first into haemangioblasts, which are precursors to blood cells, and then into mature red blood cells.

Blood Groups, Rh+ Blood, Rh- Blood

Friday, June 12th, 2009

Your blood group will be A, B, AB, or O. If you have “A” “B” or “O” blood group, you have antibodies in your blood plasma that destroy some of the other blood groups. If you have group “A” blood, you cannot receive blood that is group “B” and vice versa. If you have “O” blood, your body will create antibodies to fight “A” or “B” blood. If you have group “AB” blood however, your body will not create antibodies for any of the other blood groups.

Most of us are aware of our blood groups, which we inherit from our parents. We also know that blood transfusion is possible between two people if their blood groups are similar. But what determines our blood groups ? This is done by a protein complex called antigens on the surface of the red blood cells. These antigens are complex chemical substances found on the surface of red blood cells are different for each blood group. The two most important blood group systems in transfusion work are the ABO and Rhesus (Rh) systems.

Within the ABO system people can be one of four types - 0, A, B or AB, whilst in the Rh system they can be either Rh positive or Rh negative. Each system is inherited independently of the other. Thus, there are eight main blood groups.

Your Rh status will be listed as negative (-) or positive (+). If you have Rh- blood, your body may form antibodies against Rh+ blood and destroy it. In order for this to happen, you must first be exposed to Rh+ blood (i.e., through a blood transfusion or carrying an Rh+ fetus). This can be a problem if you have antibodies against Rh+ blood and are pregnant with an Rh+ fetus. However, there is medication that can prevent this reaction from occurring if it is given immediately after you are exposed to Rh+ blood.