Peripheral blood stem cell transplantation
A new technique in which stem cells are obtained from a patient’s blood and used in bone marrow transplantation.
Stem cells are small, round cells with a squat nucleus and scant surrounding cytoplasm. Although unremarkable in appearance, stem cells can perform what have been called “acts of biological resurrection.” Whereas other types of cells in the body have a limited lifespan and die after dividing their endowed number of times, a stem cell can reproduce forever. The stem cell is immortal (in cellular terms).
A stem cell can forgo immortality and turn into an ordinary blood cell, a red blood cell (an erythrocyte), a white blood cell (a leukocyte), or a large cell (a megakaryocyte) that fragments into the platelets needed for blood to clot.
A limited number of stem cells can miraculously repopulate the whole bone marrow, provide an endless supply of stem cells, reconstitute the entire repertory of blood cells, and restore the immune system.
To obtain the stem cells, the stem cells are lured out of the bone marrow by a special regimen of drugs. The blood is then filtered through a machine and the stem cells are skimmed off. The removal of the cells is termed pheresis or apheresis (from the Greek “aphairesis” for removal).
The stem cells then may be used right away for bone marrow transplant or stored in liquid nitrogen until needed.
Before the transplant is done, the patient receives high-dose chemotherapy and/or radiation therapy to destroy diseased cells (the leukemic cells, lymphoma cells, solid tumor cells, the diseased immune system cells in scleroderma, etc.) The stem cells are then returned to the patient, where they can produce new blood and immune cells and replace the cells destroyed by the treatment. The stem-cell preparation is infused into a vein and, once there in the blood stream, the stem cells act like homing pigeons and head straight for the bone marrow space.
Read Also:
- Peripheral iridectomy
A surgical procedure in which a hole is made in the periphery (outer part) of the iris by removing a full-thickness piece from the iris in order to treat a specific type of glaucoma called narrow-angle glaucoma (or angle-closure glaucoma).
- Peripheral nervous system
The portion of the nervous system that is outside the brain and spinal cord. Abbreviated PNS. The nerves in the PNS connect the central nervous system (CNS) to sensory organs, such as the eye and ear, and to other organs of the body, muscles, blood vessels, and glands. The peripheral nerves include the 12 cranial […]
- Peripheral neuropathy
A problem with the functioning of the nerves outside the spinal cord. Symptoms of peripheral neuropathy may include numbness, weakness, burning pain (especially at night), and loss of reflexes.
- Peripheral pulmonary stenosis with cholestasis
Also known as arteriohepatic dysplasia or Alagille syndrome, this ia a genetic disorder characterized by jaundice in the newborn period, liver disease with cholestasis, peripheral pulmonic stenosis and unusual face. Children with Alagille syndrome usually present with jaundice (yellowing of the skin and whites of the eyes) in the newborn period. Cholestasis (stagnant flow of […]
- Peripheral vascular disease
Peripheral artery disease; Varicose Veins & Spider Veins.