Misplaced Pages

#168831

25-415: Side effects are very common. They can include low blood cell counts , vomiting, loss of appetite, diarrhea, hair loss, and fever. Other severe side effects include allergic reactions and low blood pressure . Use during pregnancy will likely harm the fetus. Etoposide is in the topoisomerase inhibitor family of medication. It is believed to work by damaging DNA. Etoposide was approved for medical use in

50-569: A compatible donor cannot be found, immunosuppressive therapy is also common. Antilymphocyte globulin (ALG) or antithymocyte globulin (ATG) is mixed with cyclosporine to promote cell growth. Blood cell A blood cell (also called a hematopoietic cell , hemocyte , or hematocyte ) is a cell produced through hematopoiesis and found mainly in the blood . Major types of blood cells include red blood cells (erythrocytes), white blood cells (leukocytes), and platelets (thrombocytes). Together, these three kinds of blood cells add up to

75-432: A decrease in function of platelets (thrombasthenia), or an increase in the number of platelets (thrombocytosis). There are disorders that reduce the number of platelets, such as heparin-induced thrombocytopenia (HIT) or thrombotic thrombocytopenic purpura (TTP), that typically cause thromboses, or clots, instead of bleeding. Platelets release a multitude of growth factors including platelet-derived growth factor (PDGF),

100-443: A microscope. Today, this process is generally automated by use of an automated analyzer, with only approximately 10-20% of samples now being examined manually. Abnormally high or low counts may indicate the presence of many forms of disease, and hence blood counts are amongst the most commonly performed blood tests in medicine, as they can provide an overview of a patient's general health status. In 1658 Dutch naturalist Jan Swammerdam

125-422: A nucleus). The condition of having too few red blood cells is known as anemia , while having too many is polycythemia . Erythrocyte sedimentation rate (ESR) is the rate at which RBCs sink to the bottom (when placed in a vertical column after adding an anticoagulant). Normal values of ESR are: • 3 to 5 mm per hour in males. • 4 to 7 mm per hour in females. White blood cells or leukocytes , are cells of

150-448: A platelet is normally just 5 to 9 days. Platelets are a natural source of growth factors. They circulate in the blood of mammals and are involved in hemostasis, leading to the formation of blood clots. Platelets release thread-like fibers to form these clots. The normal range (99% of population analyzed) for platelets is 150,000 to 450,000 per cubic millimeter. If the number of platelets is too low, excessive bleeding can occur. However, if

175-663: A potent chemotactic agent, and TGF beta , which stimulates the deposition of extracellular matrix. Both of these growth factors have been shown to play a significant role in the repair and regeneration of connective tissues. Other healing-associated growth factors produced by platelets include basic fibroblast growth factor (bFGF), insulin-like growth factor 1 (IGF-1), platelet-derived epidermal growth factor, and vascular endothelial growth factor (VEGF). Local application of these factors in increased concentrations through platelet-rich plasma (PRP) has been used as an adjunct to wound healing for several decades. A complete blood count (CBC)

200-427: A process known as erythropoiesis . In adults, about 2.4 million RBCs are produced each second. The normal RBCs count is 4.5 to 5 millions per cu.mm. RBCs have a lifespan of approximately 100-120 days. After they have completed their lifespan, they are removed from the bloodstream by the spleen . Mature red blood cells are unique among cells in the human body in that they lack a nucleus (although erythroblasts do have

225-447: A ternary complex with DNA and the topoisomerase II enzyme, which is an enzyme that aids in relaxing negative or positive supercoils in DNA. Topoisomerase II normally will form a double-stranded break in one DNA double-strand, allow another to pass through, and re-ligate the broken strands. Etoposide's binding prevents topoisomerase II from re-ligating the broken DNA strands, which causes

250-444: A total 45% of the blood tissue by volume, with the remaining 55% of the volume composed of plasma , the liquid component of blood. Red blood cells or erythrocytes pors carry oxygen and collect carbon dioxide through the use of hemoglobin . Hemoglobin is an iron -containing protein that gives red blood cells their color and facilitates transportation of oxygen from the lungs to tissues and carbon dioxide from tissues to

275-461: Is a test panel requested by a doctor or other medical professional that gives information about the cells in a patient's blood. A scientist or lab technician performs the requested testing and provides the requesting medical professional with the results of the CBC. In the past, counting the cells in a patient's blood was performed manually, by viewing a slide prepared with a sample of the patient's blood under

SECTION 10

#1732909629169

300-532: Is also sometimes used in a conditioning regimen prior to a bone marrow or blood stem cell transplant. It is given intravenously (IV) or orally in capsule or tablet form. If the drug is given IV, it must be done slowly over a 30- to 60-minute period because it can lower blood pressure as it is being administered. Blood pressure is checked often during infusing, with the speed of administration adjusted accordingly. Common are: Less common are: When given with warfarin , it may cause bleeding. Etoposide forms

325-444: Is caused by an autoimmune disease when your body produces antibodies to destroy the healthy blood cells. Refractory cytopenia is caused by bone marrow not producing healthy blood cells, and can be a result of cancer. The symptoms of cytopenia vary depending on the type. The symptoms of anemia include: The symptoms of leukopenia include: The symptoms of thrombocytopenia include: Cytopenias can be caused by anything that decreases

350-444: The immune system involved in defending the body against both infectious disease and foreign materials. They are produced and derived from multipotent cells in the bone marrow known as hematopoietic stem cells . Leukocytes are found throughout the body, including the blood and lymphatic system . There are a variety of types of white blood cells that serve specific roles in the human immune system. WBCs constitute approximately 1% of

375-548: The DNA breaks made by topoisomerase II to stay broken, and also prevents the topoisomerase II molecule from leaving the site and relieving tension elsewhere. This results in a double-strand break in the DNA that can have various deleterious effects on the cell, and depletion of topoisomerase II available to relieve further tension. Cancer cells rely on this enzyme more than healthy cells, since they divide more rapidly. Therefore, this causes errors in DNA synthesis and promotes apoptosis of

400-540: The United States in 1983. It is on the World Health Organization's List of Essential Medicines . Etoposide is used as a form of chemotherapy for cancers such as Kaposi’s sarcoma , Ewing's sarcoma , lung cancer , testicular cancer , lymphoma , nonlymphocytic leukemia , and glioblastoma multiforme . It is often given in combination with other drugs (such as bleomycin in treating testicular cancer). It

425-409: The aim of creating less toxic derivatives of podophyllotoxin. The substance is a white to yellow-brown, crystalline powder. It is soluble in organic solvents. It is used in form of its salt etoposide phosphate. Etoposide was first synthesized in 1966 and U.S. Food and Drug Administration approval was granted in 1983. The nickname VP-16 likely comes from a compounding of the last name of one of

450-440: The blood volume. White blood cells are divided into granulocytes and agranulocytes , distinguished by the presence or absence of granules in the cytoplasm. Granulocytes include basophils , eosinophils , neutrophils , and mast cells . Agranulocytes include lymphocytes and monocytes . The condition of having too few white blood cells is leukopenia , while having too many is leukocytosis . There are individual terms for

475-449: The cancer cell. Etoposide is a semisynthetic derivative of podophyllotoxin from the rhizome of the mayapple (or "American mandrake", Podophyllum peltatum ). More specifically, it is a glycoside of podophyllotoxin with a D - glucose derivative. It is chemically similar to the anti-cancer drug teniposide , being distinguished only by a methyl group where teniposide has a thienyl . Both these compounds have been developed with

500-548: The chemists who performed early work on the drug (von Wartburg) and podophyllotoxin. Another scientist who was integral in the development of podophyllotoxin-based chemotherapeutics was the medical pharmacologist Hartmann F. Stähelin . Cytopenia Cytopenia is a reduction in the number of mature blood cells . It can have many causes, and commonly occurs in people with cancer being treated with radiation therapy or chemotherapy . There are also two general causes of cytopenia: autoimmune and refractory. Autoimmune cytopenia

525-454: The lack or overabundance of specific types of white blood cells. The number of white blood cells in circulation is commonly increased in the incidence of infection . Many hematological cancers are based on the inappropriate production of white blood cells. Platelets , or thrombocytes , are very small, irregularly shaped clear cell fragments, 2–3 μm in diameter, which derive from fragmentation of megakaryocytes . The average lifespan of

SECTION 20

#1732909629169

550-412: The lungs to be exhaled. Red blood cells are the most abundant cell in the blood, accounting for about 40-45% of its volume. Red blood cells are circular, biconcave, disk-shaped and deformable to allow them to squeeze through narrow capillaries. They do not have a nucleus. Red blood cells are much smaller than most other human cells. RBCs are formed in the red bone marrow from hematopoietic stem cells in

575-433: The number of platelets is too high, blood clots can form thrombosis, which may obstruct blood vessels and result in such events as a stroke , myocardial infarction , pulmonary embolism , or blockage of blood vessels to other parts of the body, such as the extremities of the arms or legs. An abnormality or disease of the platelets is called a thrombocytopathy, which can be either a low number of platelets ( thrombocytopenia ),

600-563: The production of blood cells or increases the destruction of blood cells. This includes, but is not limited to: The treatments for cytopenia vary depending on the type of cytopenia. The treatment for anemia is rest and a diet consisting of high iron foods. Medication can also be used such as: People with thrombocytopenia are advised to avoid contact with people who are ill, monitor closely for signs of infection, and take antibiotics when appropriate. Bone marrow and stem cell transplantation are effective for all types of cytopenias. However, when

625-448: Was the first person to observe red blood cells under a microscope, and in 1695, microscopist Antoni van Leeuwenhoek , also Dutch, was the first to draw an illustration of "red corpuscles", as they were called. No further blood cells were discovered until 1842 when French physician Alfred Donné discovered platelets. The following year leukocytes were first observed by Gabriel Andral , a French professor of medicine, and William Addison ,

#168831