AMS اتحاد العلوم الطبيه المساعده

Introduction Idiopathic thrombocytopenic purpura, which is also called ITP, is an autoimmune disorder that causes very low platelet counts. An autoimmune disorder is one in which a person produces antibodies against his or her own tissues. What is going on in the body? Platelets, which are made by the bone marrow, are essential for blood clotting. In ITP, the body produces antibodies that attack the platelets and destroy them. Normally the body makes antibodies to fight infections. In ITP, the body for some reason makes antibodies against its own tissues, called autoantibodies. These autoantibodies act to destroy platelets. The result is a low platelet count, known as thrombocytopenia. The cause of ITP is unknown. But certain viral infections seem to cause some cases of ITP. This in turn creates antibodies that attack the platelets, which are then removed from the bloodstream. Normal platelet counts are between 150,000 and 450,000. People with ITP may have very l...

Introduction The direct Coombs' test detects antibodies, which are proteins that react against other molecules, on the surface of an individual's red blood cells. Who is a candidate for the test? The direct Coombs' test is usually done to see if a person is making antibodies against his or her own red blood cells. These antibodies are called "autoantibodies." How is the test performed? To perform the direct Coombs' test, a blood sample is taken from a vein on the forearm or hand. To get a blood sample, the skin over the vein is cleaned with an antiseptic. Next, a strong rubber tube, or "tourniquet," is wrapped around the upper arm. This enlarges the veins in the lower arm by restricting blood flow through them. A fine needle is gently inserted into a vein, and the tourniquet is removed. Blood flows from the vein through the needle and is collected in a syringe or vial for testing in the laboratory. After the needle is withdrawn...

Introduction Chemotherapy refers to medicines that can kill or control cancer. Chemotherapy medicines target and treat a specific area affected by cancer. These medicines travel to all parts of the body through the bloodstream. Chemotherapy is a systemic treatment, which means it is a treatment that affects the whole body. There are many kinds of chemotherapy. The medicine chosen will depend on the type and the extent of the cancer, as well as the potential side effects of the medicine. Each medicine will have its own specific side effects. Most of the time, chemotherapy is given as an outpatient procedure in a clinic or a doctor's office. People generally do not need to stay overnight in the hospital to receive chemotherapy. Who is a candidate for the procedure? Following are some of the common uses of chemotherapy: Some types of cancer respond better to chemotherapy than others. Leukemia, lymphoma, breast cancer, and colorectal cancer are often tre...

Introduction Cancer in the throat occurs in the passages from the neck to the rest of the body. This includes the voice box, or larynx, and the areas behind the oral cavity, known as the pharynx. What is going on in the body? The throat is exposed to every substance a person takes into the body whether by breathing, drinking, or eating. Some of these substances, especially tobacco, can cause severe damage to the cells lining the throat. Damage over time may cause cells to undergo changes that lead to cancer. The person may have more than one cancer develop at a time in this area because the damage affects the whole area. After a cell becomes cancerous, it will begin to grow and divide uncontrollably. The cancer cells will then form a tumor. The tumor spreads by invading the tissue around it. Some of the cancer cells will enter the system that drains fluids into lymph nodes in the neck. The lymph nodes filter the blood and help fight infections. When a cancer cel...

Introduction A food allergy is an abnormal response of the immune system that is caused by the protein in certain foods. A food allergy is not the same as food intolerance. A person with food intolerance may have symptoms, such as abdominal distress, after eating a certain food. However, this response is not caused by the immune system. What is going on in the body? A food allergy occurs when an immune response occurs. An immune response is a normal response of the body to something it sees as abnormal. Usually the response is to bacteria, viruses, and toxins. Sometimes the body will recognize certain foods as abnormal. When foods are recognized as abnormal, the body produces an antibody known as IgE. IgE reacts with mast cells, which are part of the immune system. The reaction affects mast cells in many areas of the body, including the following: lungs nose and throat skin stomach and bowels When the IgE reacts with the mast cells, histamine is produced. ...