MPN Glossary

One of the biggest problems when it comes to understanding anything is knowing the language that is being used to send the message. Let’s face it, medicine and its nuances are really just a foreign language and just like when we visit new and exotic destinations, it pays to have a lexicon to help with all of the essential finer points.

Hence, the Glossary provided here is just a short list to better comprehend some of the more basic terms and jargon that might be applied from time to time in the field of MPNs.

Acute Myeloid Leukaemia (AML):

Also known as acute myelogenous leukaemia or acute non- lymphocytic leukemia. A quickly progressive malignant disease in which there are too many immature blood forming cells in the blood and bone marrow, the cells being specifically those destined to give rise to types of white blood cells that fight infections.

Agranulocyte: A leukocyte without definite cytoplasmic granules.

Agranulocytosis: Complete or nearly complete absence of the granular leukocytes from the blood and bone marrow.

Albumin: Major Blood protein. Monitors nutritional status, or sometimes kidney status in protein losing kidney problems.

Alkaline Phosphatase: A liver enzyme, elevated in obstructive conditions of the liver.

Alleles: Alternate forms or varieties of a gene. The alleles for a trait occupy the same locus or position on homologous chromosomes and thus govern the same trait. However, because they are different, their action may result in different expressions of that trait.

Alloantibody: A type of antibody directed against substances recognised as foreign to the host. (see Alloimmunisation)

Allogeneic or Allogeneic Blood: Blood from someone else that matches yours, usually from a volunteer Blood donor. Also referred to as homologous Blood.

Aleukemic Leukemia: A fatal condition of the blood forming

tissues, characterised by marked proliferation of

immature cells in the bone marrow, without their presence, in any great numbers, in the blood steam.

Anaemia: A condition in which the blood is deficient in quantity or quality of erythrocytes. Weakness, fatigue, and paleness resulting from a deficiency of red Blood cells or insufficient amounts of haemoglobin molecules within the red cells.

Anisocytosis: Condition which is characterised by a considerable variation in the size of cells, especially red Blood cells.

Apheresis: A procedure where whole Blood is removed from the body and desired component(s), such as plasma or platelets is retained and the remainder of the Blood is returned to the donor.

Aplastic Anaemia: An anaemia caused by deficient red Blood cell production by the bone marrow.

Autoimmune: The process of making antibodies against one’s self (one’s intrinsic antigens).

Anomaly: Abnormality.

Anoxemia: Lack of normal proportion of oxygen in the blood.

Anticoagulant: A substance that prevents the coagulation of blood.

Aplasia: Incomplete or defective blood development; cessation of blood cell formation.

Aplastic Anaemia: Anaemia characterised by incomplete or effective blood development.

Asynchronous: Uncoordinated development as in abnormal cell development.

Basket Cell: A degenerated primitive cell which has ruptured and in which the cell nucleus appears as a pale staining smear without prescribed form or shape.

Basopenia: An abnormal decrease in the number of basophils.

Basophil: A granular leukocyte, the granules of which have affinities for the basic dye of Wright stain (methylene blue). The granules are large, irregular and blueblack in color.

Basophilia: An abnormal increase in the number of basophils.

Basophilic: Staining readily with basic dyes, for example, blue with Ramanovsky type stains.

Binary Fission: Simple cell division.

Bleeding Time: The time required for a small standardized wound, made in the capillary bed of the finger or ear lobe, to stop bleeding.

Blood Cells: The red (erythrocytes) and white (leukocytes) Blood cells which comprise the minor portion of whole Blood.

Blood Count: The complete Blood count, (CBC), or Full Blood Count (FBC).

Blood Dyscrasia: A disease of the blood or blood-forming organs.

Blood type: Everyone’s Blood falls into one of four groups (4), or types: A, B, AB or O. The type depends on the presence or absence of certain substances on red Blood cells. Blood types are inherited.

Bone marrow: The soft tissue located in the cavities of bones which is responsible for Blood cell and platelet production.

Buffy Coat: The layer of leukocytes that collects immediately above the erythrocytes in sedimented or centrifuged whole blood.

Cabot’s Rings: Lines in the form of loops or figures of eight seen in erythrocytes in severe anaemias.

Cortisol: The body’s natural stress fighting and anti-inflammatory hormone.

Centriole: A minute cell organoid within the centrosome.

Centrosome: An area of condensed cytoplasm active in mitosis.

Chemotaxis: the phenomenon of movement of leukocytes caused by a chemical influence.

Chromatin: The more stainable portion of the cell nucleus contains genetic materials.

Clot Retraction: The rate and degree of contraction of the blood clot.

Coagulation Time: The time required for venous blood, in the absence of all tissue factors, to clot in glass tubes under controlled conditions.

Cocatalyst: A substance that works in tandem with another group of chemicals to accelerate a reaction velocity without being used up in the reaction.

Color Index: The ratio between the amount of hemoglobin and the number of red blood cells.

Complete Blood Count (CBC): A hematology study which consists of a red cell count, white cell count, platelets, haematocrit, haemoglobin, and blood smear study including differential white cell count.

Component Blood: is made up of different “parts” or components: red Blood cells, plasma, platelets and several types of white Blood cells. Donated Blood is often separated into components so that patients can be transfused only with the “part” of Blood needed.

Congenital: Born with a person; existing at or before birth.

Cooley & rsquo’s Anemia (Mediterranean Disease or Thalassemia): A chronic progressive anemia commencing early in life and characterised by many normoblasts in the blood, unusual facies, splenomegaly and familial and racial incidence. Target type red blood cells are often present in the peripheral blood.

Crenation: The scalloped or notched appearance of the periphery of erythrocytes found when the cells are suspended in a hypertonic solution. Also found in smears, caused by dirty glassware, slow drying, and poor smearing technique.

Creatinine: A measure of the kidneys’ ability to excrete waste. Comparing the excretion of creatinine to urea helps assess kidney function versus dehydration.

Cross Match: The finding of exact similarities between a patient’s Blood and a donor’s Blood. This process involves careful and exacting laboratory tests.

Cytoplasm: Protoplasm of a cell excluding the nucleus.

DNA: Deoxyribonucletic acid.

Differential Count: An enumeration of the types of white blood cells seen on a stained blood smear.

Discrete: Separate.

Dyscrasia: Abnormality.

Ecchymosis: Subcutaneous extraversion of blood covering a large area.

Endothelial Leukocyte: Monocyte.

Electrolytes: Electrolytes are a large category of substances dissolved in plasma. The balance of water and salt is critical to good health. Electrolyte testing reveals important indicators of the amount of water and salt in your body, including: sodium, potassium, calcium, chloride, bicarbonate (carbon dioxide) and magnesium. These chemicals are essential in many bodily functions including fluid balance, nerve conduction, muscle contraction (including the heart), Blood clotting and pH balance.

Engraftment: The process by which transplanted or transfused cells (for example, after a bone marrow transplant) begin to grow and reproduce themselves within the recipient.

Eosinopenia: An abnormal decrease in eosinophils.

Eosinophil: A granular leukocyte, the granules of which have an affinity for the acid dye of Wright & rsquo’s stain (eosin). The granules are large, round, uniform in size, red orange in colour and are shiny and retractile.

Eosinophilia: A relative or absolute leukocytosis in which the main increase is in eosinophils.

Eosinophilic: Readily stained with eaosin, redorange stain.

Epigastric: Pertaining to the upper middle portion of the abdomen.

Erythremia: A disease marked by persistent polycythemia and increased blood volume also polychythemia vera.

Erythrocyte: Red blood cell.

Erythrocytosis: An increase in the total number of erythrocytes.

Erythrogenic: Producing erythrocytes.

Erythroleukemia: An abnormal condition characterised by proliferation of erythroblastic and myeloblastic cells.

Erythropenia: A decrease in the number of red cells in the blood.

Erythropoiesis: The production of erythrocytes.

Ethnic: Referring to people with origins from different parts of the world.

Etiology: The theory of the causation of a disease.

Extravascular: Occurring outside the blood vessels.

Extrinsic: Originating outside of the particular area.

False-negative: a Blood test result that is incorrectly normal in a person who has the suspected disease.

False-positive: a Blood test result that is incorrectly abnormal in a person who does not have the suspected disease.

Fibril: A microscopic filament often composed of fibrin.

Fibrin: The end product of the clotting mechanism that forms a network of fibers that enmesh the formed elements of blood.

Fibrinogen: The precursor of fibrin that is present normally in the plasma and produced by the liver.

FFP: Fresh Frozen Plasma; a part of whole Blood.

Folate: A B vitamin.

Formed Elements: The red and white Blood cells and platelets found in whole Blood.

Fragility Test (Osmotic): A test devised to measure the resistance of the erythrocytes to break down (hemolyze) when subjected to varying concentrations of hypotonic salt solutions.

Full Blood Count:

The full blood count (FBC) is one of the most commonly ordered tests and provides important information about the kinds and numbers of cells in the blood: red blood cells (RBC), white blood cells (WBC) and platelets. Abnormalities in any of these types of cells can indicate the presence of important medical disorders.

Golgi Apparatus: A meshwork of lipid containing fibrils within the cytoplasmic portion of a cell.

Granulocyte: A white blood cell that contains specific cytoplasmic granules (neutrophils, eosinophils, and basophils); these granules are peroxidase positive.

Granulocytosis: The presence of increased numbers of granulocytes in the blood.

Granulocytopenia (Granulopenia): A decrease in the number of granulocytes in the blood.

Granulopoiesis: The production of granulocytes.

Glucose: Blood sugar.

GOT, GPT (SGOT, SGPT): Liver enzymes. Elevated for a variety of reasons. Checked for suspected liver disease, also for suspected mononucleosis, or to monitor the effect of long term drug therapy on the liver.

Graft-Versus-Host-Disease (GVHD): A disease caused by the infusion or transplantation of immune cells from one individual into another.

Haplotypes: The genetic constitution of individuals with respect to one member of a pair of genes; sets of single alleles or closely linked genes that tend to be inherited together, such as those of the major histocompatibility complex; portions of phenotypes determined by genes located on one of a pair of chromosomes.

Hemacytometer: A calibrated chamber in which blood cells are counted.

Haematin: A brown or blueblack amorphous iron substance that unites with globin and forms hemoglobin.

Haematocrit: The packed cell volume (PVC) of red blood cells obtained by globin and forms haemoglobin.

Haematology: The branch of medicine that deals with the study of blood cells, blood producing organs and the manner in which these cells and organs are affected in disease.

Haematologist: A medical term referring to a Blood specialist.

Haematopoiesis (Haemopoiesis): The process of formation, development, and differentiation of the formed elements of whole Blood.

Haemoglobin: The coloring matter of the red blood cells. A complex ironbearing

pigment that carries oxygen and carbon dioxide.

Haemoglobinuria: The presence of free haemoglobin in the urine.

Haemolysis: The dissolution or dissolving of the erythrocytes.

Haemolytic Anaemia: That type of anemia characterised by excessive intravascular destruction of red cells.

Haemophilia: A hereditary disease characterised by a prolonged coagulation time and repeated haemorrhages, occurring only in males and transmitted only by females and affected males. The cause is a deficiency in a plasma factor (antihemophilic globulin or thromboplastinogen) resulting in a defect in thromboplastic activity.

Haemoptysis: The spitting of blood; coughing up blood.

Haemostasis: The checking of the flow of blood, especially from a vessel.

Haematoma: Subcutaneous effusion of blood with resulting swelling, pain, and discoloration, forming a tumorlike mass.

Haematopoietic (Hemopoietic): Blood forming.

Hemogram: The blood picture.

Hepatic: Originating from the liver.

Heterozygous: Derived from germ cells unlike in respect to one or more factors.

HLA Type: Antigens present on most cells of the body which are unique to the individual. It may be considered to be the individual’s genetic fingerprint.

Homeostasis: Stability in normal body states.

Homologous Chromosomes: Chromosomes that are paired during meiosis. Such chromosomes are alike with regard to size and also position of the centromere. They also have the same genes, but not necessarily the same alleles, at the same locus or location.

Homozygous: Derived from germ cells that are alike.

Howell Jolly Bodies: Small basophilic particles sometimes found in erythrocytes, remnants of nuclear material.

Hygroscopic: Readily taking up and retaining water.

Hypercalcemia: An excess of calcium in the Blood.

Hyperplasia: An increase in cell formation.

Hypertonic: Greater than isotonic concentration.

Hypertrophy: Enlargement of an organ or part due to increase in the size of the constituent cells.

Hypocalcemia: A deficiency of calcium in the Blood.

Hypochromia: A decrease in colour of the erythrocytes, hence a decrease in their haemoglobin content.

Hypoplasia: A decrease in cell formation.

Hypothermia: A condition of characterized by low body temperature.

Hypotonic: Less than isotonic concentration.

Hypovolemia: An abnormally low volume of Blood circulating through the body. It may result in hypovolemic shock.

Hypoxemia: Low oxygen levels in the Blood.

Idiopathic: Disease of unknown cause.

Immunosuppressed: A condition brought about by disease or chemotherapy where the individual is highly susceptible to infection.

Inclusion: Usually lifeless, an accumulation of fats, proteins, crystals pigments or secretory granules within a cell cytoplasm.

Inhibitor: A substance, directed against a coagulation factor or factors, which interferes with the coagulation process.

Irradiated Red Blood Cells: Red Blood cells treated with exposure to radiation in order to inactivate white Blood cells which may cause graft-versus-host-disease.

Intravascular: Occurring within the blood vessels.

Intrinsic: Situated within the particular part.

In Vitro: Within a test tube (glass, etc.).

In Vivo: Within the living organism, as in life.

Isotonic: Solutions with the same osmotic pressure.

Jaundice: Yellow mass of the skin and eyes due to the presence of blood pigments in the blood; follows excessive destruction of the blood, obstruction of the bile passage, diffuse liver disease, certain infections, toxic chemical agents and drugs.

Juvenile Cell: In the Schilling classification, the cell between the myelocyte and band forms; also metamyelocyte.

Karyolysis: Apparent destruction of the nucleus of a cell.

Karyorrhexis: Fragmentation of the nucleus; a degenerative process usually followed by karyolysis.

L.E. Cell: A large segmented neutrophil or eosinophil that contains ingested autolyzed nuclear fragments in its cytoplasm.

Leukaemia: An ultimately fatal disease of the blood-forming organs characterised by increased numbers of leukocytes and associated anaemia.

Leukemoid Crisis or Reaction: A temporary appearance of immature leukocytes in the blood stream, with a marked increase in the total white count. In the laboratory sometimes temporarily indistinguishable from leukaemia.

Leukocyte: White blood cell.

Leukocytosis: An increase in leukocytes in the blood.

Leukoreduced: Removal of white Blood cells from products in order to prevent certain transfusion reactions such as fever, chills, and alloimmunisation.

Leukopenia: A reduction in the number of leukocytes in the blood.

Leukopoiesis: The production of leukocytes.

Liver Enzymes: Most often SGPT, SGOT; or alkaline phosphatase. Injury to the liver from infection or obstruction of bile flow causes damage to the cells; they leak various enzymes into the Bloodstream; their detection in increased amounts most often means injury to the liver.

Lupus-like anticoagulant: A circulating anticoagulant that arises spontaneously in patients with a variety of conditions (originally found in patients with lupus erythematosus) and directed against phospholipid components of the reagents used in laboratory tests for clotting factors. See

antiphospholipid antibody.

Lymphadenopathy: Abnormal enlargement of lymph nodes.

Lymphoblast: A lymphocytic precursor cell found in the bone marrow. The cell is 10—20 μm in diameter and has a high nuclear/cytoplasmic ratio. The nucleus has a fine (lacy) chromatin pattern with one or two nucleoli. The cytoplasm is agranular and scant. It stains deep blue with romanowsky stain. The cell contains terminal deoxynucleotidyltransferase (TdT) but no peroxidase, lipid, or esterase.

Lymphocyte: A white blood cell having a round or oval nucleus and sky blue cytoplasm. The nuclear chromatin is densely clumped but separated by many clear areas giving a “hill and valley” effect. A few redpurple (azurophilic) granules may be present in the cytoplasm.

Lymphocytosis: A relative or absolute increase in the number of circulating lymphocytes.

Lymphokines: Substances released by sensitized lymphocytes and responsible for activation of macrophages and other lymphocytes.

Lymphoma: Malignant proliferation of lymphocytes. Most cases arise in lymph nodes, but it can begin at many extranodal sites. The lymphomas are classified as to B or T cell and low, intermediate, or high grade.

Lymphopenia: An abnormal decrease in the number of lymphocytes.

Lysis: Destruction by a specific agent.

Macrocyte: An erythrocyte larger than normal.

Macrocytosis: An increase in the number of macrocytes.

Magnesium: An essential Blood salt. Necessary for nerve function. Most usually ordered in newborns.

Malignant neoplasm: A clone of identical, anaplastic (dedifferentiated), proliferating cells. Malignant cells can metastasize.

Mast Cell: A basophil or a true tissue cell.

Maturation Factor: A substance that will cause cells to ripen and care to maturity.

Mean Corpuscular Haemoglobin (MCH): The average amount of haemoglobin in the red blood cell.

Mean Corpuscular Haemoglobin Concentration (MHC): The average percent haemoglobin saturation in the red blood cell.

Mean cell volume (MCV): An indicator of the average volume of individual erythrocytes reported in femtoliters. The reference interval for MCV is 80—100 fl. This parameter is useful when evaluating erythrocyte morphology on a stained blood smear. The MCV usually will correlate with the diameter of the erythrocytes observed microscopically. The MCV can be calculated from the hematocrit and erythrocyte count: MCV (fl) = hematocrit (L/L) divided by Erythrocyte count (X 1012/L) X 1000.

Mean platelet volume: Mean volume of a platelet population; analogous to the MCV of erythrocytes.

Medullary haematopoiesis: Blood cell production and development in the bone marrow.

Meiosis: Cell division in specialised tissues of ovaries and testes which results in the production of sperm or ova. Meiosis involves two divisions and results in four daughter cells, each containing only half the original number of chromosomes23 in the case of humans. These cells can develop into gametes.

Megakaryoblast: The parent cell of the megakaryocytic series.

Megakaryocyte: An extremely large cell with an irregular lobed, ring or dough nut shaped nucleus that stains bluish purple. The cytoplasm is abundant, light blue and is packed with fine azurophilic granules. This cell gives rise to thrombocytes.

Megaloblast: The type of red cell precursor found in pernicious anaemia. This differs from the normal erythrocyte precursor (normoblast) in that the megaloblast is larger and the nuclear chromatin has a fine meshwork or scroll

design.

M.E. Ratio: The ratio of myeloid to erythroid cells in the bone marrow.

Mesentery: The fold of peritoneum that attaches the intestine to the posterior abdominal wall.

Metabolic: Pertaining to all chemical functions within the body.

Metamyelocyte: Juvenile cell of Schilling.

Metarubricyte: An erythrocyte with a pyknotic, contracted nucleus. Also called orthochromatophilic normoblast.

Methemoglobin: A spectroscopically detected compound of haemoglobin found in nitrobenzol, and other poisonings. The blood is a chocolate brC1.oln colour to the eye.

Microcyte: An erythrocyte smaller than normal.

Microcytosis: An increase in the number of microcytes

Micron: One thousandth of a millimeter, the common unit of microscopic measure.

Mitochondria: Granular components of a cell cytoplasm active in oxidative processes.

Mitosis: A series of changes through which the nucleus passes in indirect cell division. A tissue showing many cells in mitosis indicates rapid growth of that tissue.

Monoblast: The parent cell of the monocytic series.

Monocyte: A large white blood cell with a pale bluegray cytoplasm containing fine azurophilic granules. The nucleus is spongy and lobulated.

Monocytosis: A relative or absolute increase in the number of circulating monocytes.

Mucosa: Mucous membrane.

Multiple myeloma: Plasma cell malignancy characterized by increased plasma proteins. Mutation Any change in the nucleotide sequence of DNA. In instances where large sequences of nucleotides are missing, the alteration is referred to as a deletion.

Myeloblast :The first microscopically identifiable granulocyte precursor. It is normally found in the bone marrow. The cell is large (15—20 μm) with a high nuclear/cytoplasmic ratio. The nucleus has a fine chromatin pattern with a nucleoli. There is moderate amount of blue, agranular cytoplasm.

Myelocyte: A granulocytic precursor cell normally found in the bone marrow. The cell is 12—18 μm in diameter with a pinkish granular cytoplasm. There are both primary and secondary granules present.

Myelodysplastic syndromes (MDS): A group of primary neoplastic pluripotential stem cell disorders characterized by one or more cytopenias in the peripheral blood together with prominent maturation abnormalities (dysplasia) in the bone marrow.

Myelofibrosis with myeloid metaplasia: A myeloproliferative disorder characterised by excessive proliferation of all cell lines as well as progressive bone marrow fibrosis and blood cell production at sites other than the bone marrow, such as the liver and spleen. Also called agnogenic myeloid metaplasia and primary myelofibrosis.

Myeloid Cells: The granular leukocytes and their stem cells.

Myelopoiesis: Formation of bone marrow and the blood cells that originate in the bone marrow.

Myeloproliferative: Rapid production of bone marrow constituents.

Necrosis: The death of a circumscribed portion of tissue. Simple necrosis is degeneration of the cytoplasm and nucleus without change in the gross appearance of the tissue.

Neoplastic Disease: Another term for cancer.

Neurologic: Refers to the brain, spinal cord, and nerves.

Neutropenia: A decrease in the number of neutrophils in the blood.

Neutrophilia: An increase in neutrophils.

Nonhemolytic: Refers to transfusion reactions where the red Blood cell is not destroyed.

Normoblast: The nucleated precursor of the normal red blood cell. Also called a rubriblast.

Normocyte (Erythrocyte): A red blood cell of normal size.

NRBC: Nucleated red cell, usually a metarubricyte when seen in the peripheral blood smear.

Nucleolus: An intra-nuclear pale blue body, surrounded: by a dense condensation of chromatin.

Occult Blood: The presence of blood that cannot be detected except by special chemical tests.

Oligochromemia: A decrease in haemoglobin.

Oligocythaemia: A decrease in the number of erythrocytes.

Oncologic and Oncology: Terms referring to the study of cancer.

Organoid: Structures present in cells resembling organs.

Ovalocyte: An elliptical erythrocyte.

Oxyhaemoglobin: The bright red haemoglobin that is loosely combined with oxygen and found in arterial blood.

Pancytopenia: A reduction in all three formed elements of the blood, namely, the erythrocytes, leukocytes and thrombocytes.

Pathology: The treatment of the essential nature of disease, particularly structural and functional changes in tissues and organs of the body caused by disease.

Pathologic Increase (Or Decrease): Due to abnormal function or disease, as contrasted to physiological (due to normal body function).

Pernicious Anaemia: A chronic, macrocytic anaemia caused by a defect in a deficiency in the production of red blood cells through a lack of vitamin B₁₂. There is accompanying megaloblastic erythropoiesis, poikilocytosis, granulocytic hyper-segmentation, achlorhydia, and neurological disturbances.

Peripheral Stem Cell Collection and Processing: The removal, separation and freezing of peripheral Blood or marrow, which contain stem cells, for later reinfusion to restore a patient’s Blood manufacturing capability after radiation or chemotherapy.

Petichiae: Small spots on the skin formed by subcutaneous effusion of blood (also purpura and ecchymoses).

Phagocytosis: The destruction of organisms and extraneous matter by a process of envelopment and absorption.

Phlebotomy: To puncture a vein for the purpose of withdrawing Blood; having to do with Blood transfusion, diagnosis, or experiment, and treatment.

Plasma: The fluid portion of the blood composed of serum and fibrinogen, obtained when an anticoagulant is used.

Plasma Cell: A lymphocyte like cell with an eccentrically placed deep staining nucleus. The nuclear chromatin is distributed in a “wheelspoke” fashion. The cytoplasm is deep blue with a lighter halo about the nucleus.

Platelets (PLTs – Thrombocytes): Cytoplasmic fragments of megakaryocytes (bone marrow cells). Platelets contain cytoplasmic granules; however, they lack nuclei and are part of the formed elements of Blood. They are colourless cells whose main function is to control bleeding. Platelets are essential to normal Blood clotting. They can be destroyed during treatment for cancer, leukaemia, aplastic anaemia and other diseases.

Platelet Transfusion Refractoriness: The inability of platelet transfusions to adequately increase the platelet count.

Pooling: The mixing together, in a vat, of the Blood plasma that has been separated from the whole Blood donated by thousands to tens of thousands of Blood donors for purposes of facilitating further treatment and ease of management of resources.

Poikilocyte: A red blood cell having abnormal shape (pearshape, sickle shape, etc.).

Poikilocytosis: Increased number of abnormally shaped erythrocytes.

Polychromasia: Diffuse basophilia of the erythrocytes.

Polychromatophilia: The presence in the stained blood smear of immature, nonnucleated, bluishstaining red blood cells.

Polycythaemia (rubra) Vera (PV): An increase in the total number of erythrocytes. (See erythremia.).

Precursor: A substance from which another substance is formed.

Promyelocyte: The precursor of the myelocyte having nonspecific azurophilic (redpurple) cytoplasmic granules.

Prophylactic: Preventative.

Prorubricyte: The second stage of development of the red cell.

Protein Electrophoresis: A Blood test to determine the levels of the immune proteins (globulins, or antibodies), and albumin.

Protime (PT): Prothrombin time. A test of the Blood clotting system and a general test of the liver’s capacity to synthesize needed Blood proteins.

Prothrombin: The inactive precursor of thrombin that is formed in the liver and present normally in the plasma. Its formation depends upon adequate vitamin K.

Punctate Basophilia: Small basophilic aggregates in the erythrocytes that stain blue with the basic dye of Wright’s stain; also basophilic stippling.

Purpura: Small spots on the skin formed by subcutaneous effusion of blood.

Pyknosis: A condensation and reduction in size of the cell and its nucleus.

Reduced Haemoglobin: A combination of haemoglobin and carbon dioxide that is found in venous blood.

Renal :Relating to the kidney.

Reticulocyte: A red blood cell showing a reticulum or network when stained with vital dyes (for example, brilliant cresyl blue). The stage between the nucleated red cell and the mature erythrocyte.

Reticulocytosis: An increase above normal values of reticulocytes in†peripheral blood.

RNA: Ribonucleic acid.

Rouleaux Formation: The arrangement of red cells with their flat surfaces facing, in which they appear as figures resembling stacks of coins.

Rubricyte: Polychromatophilic normoblast.

Saline: A solution comprised primarily of salt water.

Sedimentation Rate, Erythrocyte (ESR): The rate at which red cells will settle out in their own plasma in a given time under controlled conditions.

Serum: The fluid portion of the blood, after clot formation.

Shift to the Left: A term used to designate that condition in which the immature forms of the neutrophils are increased above their normal number.

Shift to the Right: Increase in mature, pyknotic, and hypersegmented neutrophils.

Sickle Cell: A sickle or crescent shaped erythrocyte.

Sickle Cell Anaemia: This is a hereditary and familial form of chronic, haemolytic anaemia essentially peculiar to Negroes. It is characterised clinically by symptoms of anaemia, joint pains, leg ulcers, acute attacks of abdominal pain and is distinguished haematologically by the presence of distinct haemoglobin, peculiar sickleshaped and oatshaped red corpuscles, and signs of excessive blood destruction and active blood formation.

Smudge Cell: A ruptured white cell; also basket cell, or degenerated cell.

Spherocyte: A red blood cell that is more spherical, smaller, darker, and more fragile than normal.

Stasis: A stoppage of blood flow.

Supravital Stain: A stain of low toxicity that will not cause death to living cells or tissues.

Synchronous: Occurring at the sane time and in a regular pattern.

Target Cell (Leptocyte): An abnormal, thin erythrocyte characteristic of Cooley’s or Mediterranean anaemia.

Transfusion: Replacing Blood or Blood components a body has lost in surgery, through an accident, or as a result of medical treatment such as chemotherapy.

Transient Ischaemic Attack (TIA):

A transient ischaemic attack happens when the blood supply to your brain is blocked temporarily. When the blood supply is stopped, the brain cells in the area start dying, and you experience signs that something is wrong.

If the blockage clears and the blood supply starts again, the brain gets the oxygen and nutrients it needs and the signs disappear. This makes a TIA different to a stroke, where the brain cells die and your brain is permanently damaged.

After a TIA, your risk of stroke is higher. Stroke can lead to death or disability. A TIA is a warning that you may have a stroke and an opportunity to prevent this from happening.

Triturate: To grind together.

Thrombin: This is an enzyme formed from prothrombin that converts fibrinogen to fibrin. This is not present in circulating blood.

Thrombocyte: A blood platelet.

Thrombocytopenia: A decrease in blood platelets; also thrombopenia.

Thrombocytosis: An increase in blood platelets, (Thrombocytes).

Thromboplastin: The substance that initiates the process of blood clotting. It is released from injured tissue and/or formed by the disintegration of platelets in combination with several plasma factors.

Thrombopoiesis: The production of thrombocytes.

Thrombosis: Formation of a thrombus, or blood clot.

Vacuole: A space or cavity formed in the protoplasm of a cell.

Venipuncture: The act of puncturing a vein in order to remove a sample of blood.

Viscous Metamorphosis: Friction between molecules resulting in a structural change.

Vitamin K: A vitamin constituent of the normal diet requiring bile salts for absorption. The liver in the production of prothrombin utilises this vitamin.

Von Willebrand Disease: A Blood clotting disorder.

Warfarin Effect: Refers to the effect of thinning of the Blood by a medication known as warfarin or coumadin.

White Blood Cells (WBCs or Leukocytes): Spherical shaped cells which contain nuclei and comprise the smaller number of cells of the formed elements of whole Blood. The major portion of the buffy coat is composed of white Blood cells. White Cells are protective cells in the Bloodstream. They attack bacteria by squeezing through capillary walls to reach the area of infection. (see Leukocytes)

Whole Blood: A general description for a sample of Blood taken from the venous or arterial circulation. It is composed of Blood cells, platelets, and plasma.

Xanthochromia: A yellowish discolouration, usually associated with spinal fluid.