Blood Component Removal: Any procedure in which blood is withdrawn from a donor, a portion is separated and retained and the remainder is returned to the donor.Blood Component Transfusion: The transfer of blood components such as erythrocytes, leukocytes, platelets, and plasma from a donor to a recipient or back to the donor. This process differs from the procedures undertaken in PLASMAPHERESIS and types of CYTAPHERESIS; (PLATELETPHERESIS and LEUKAPHERESIS) where, following the removal of plasma or the specific cell components, the remainder is transfused back to the donor.Blood Banks: Centers for collecting, characterizing and storing human blood.Blood Transfusion: The introduction of whole blood or blood component directly into the blood stream. (Dorland, 27th ed)Platelet Transfusion: The transfer of blood platelets from a donor to a recipient or reinfusion to the donor.Blood DonorsErythrocyte Transfusion: The transfer of erythrocytes from a donor to a recipient or reinfusion to the donor.Leukocyte Reduction Procedures: The removal of LEUKOCYTES from BLOOD to reduce BLOOD TRANSFUSION reactions and lower the chance of transmitting VIRUSES. This may be performed by FILTRATION or by CYTAPHERESIS.Plasma: The residual portion of BLOOD that is left after removal of BLOOD CELLS by CENTRIFUGATION without prior BLOOD COAGULATION.Piezosurgery: The use of HIGH-ENERGY SHOCK WAVES, in the frequency range of 20-30 kHz, to cut through mineralized tissue.Subgingival Curettage: Removal of degenerated and necrotic epithelium and underlying connective tissue of a periodontal pocket in an effort to convert a chronic ulcerated wound to an acute surgical wound, thereby insuring wound healing and attachment or epithelial adhesion, and shrinkage of the marginal gingiva. The term is sometimes used in connection with smoothing of a root surface or ROOT PLANING. (Jablonski; Illustrated Dictionary of Dentistry, 1982)Blood Preservation: The process by which blood or its components are kept viable outside of the organism from which they are derived (i.e., kept from decay by means of a chemical agent, cooling, or a fluid substitute that mimics the natural state within the organism).Blood Grouping and Crossmatching: Testing erythrocytes to determine presence or absence of blood-group antigens, testing of serum to determine the presence or absence of antibodies to these antigens, and selecting biocompatible blood by crossmatching samples from the donor against samples from the recipient. Crossmatching is performed prior to transfusion.Blood Cells: The cells found in the body fluid circulating throughout the CARDIOVASCULAR SYSTEM.Lasers, Solid-State: Lasers which use a solid, as opposed to a liquid or gas, as the lasing medium. Common materials used are crystals, such as YAG (YTTRIUM aluminum garnet); alexandrite; and CORUNDUM, doped with a rare earth element such as a NEODYMIUM; ERBIUM; or HOLMIUM. The output is sometimes additionally modified by addition of non-linear optical materials such as potassium titanyl phosphate crystal, which for example is used with neodymium YAG lasers to convert the output light to the visible range.Cytapheresis: Separation of one or more kinds of cells from whole blood with the return of other blood cell constituents to the patient or donor. This is accomplished with an instrument that uses centrifugation to separate the cells into different layers based on the differences in cell density (displacement) or drag coefficients in a current (elutriation). The procedure is commonly used in adoptive transfer to isolate NK cells, lymphocytes, or monocytes.Blood Group Incompatibility: An antigenic mismatch between donor and recipient blood. Antibodies present in the recipient's serum may be directed against antigens in the donor product. Such a mismatch may result in a transfusion reaction in which, for example, donor blood is hemolyzed. (From Saunders Dictionary & Encyclopedia of Laboratory Medicine and Technology, 1984).Blood: The body fluid that circulates in the vascular system (BLOOD VESSELS). Whole blood includes PLASMA and BLOOD CELLS.Blood Buffy Coat: The fraction of a blood sample, following CENTRIFUGATION, that is distinguished as a thin light-colored layer between the RED BLOOD CELLS, underneath it, and the PLASMA, above it. It is composed mostly of WHITE BLOOD CELLS and PLATELETS.Duty to Warn: A health professional's obligation to breach patient CONFIDENTIALITY to warn third parties of the danger of their being assaulted or of contracting a serious infection.Mandatory Reporting: A legal requirement that designated types of information acquired by professionals or institutions in the course of their work be reported to appropriate authorities.Smear Layer: Adherent debris produced when cutting the enamel or dentin in cavity preparation. It is about 1 micron thick and its composition reflects the underlying dentin, although different quantities and qualities of smear layer can be produced by the various instrumentation techniques. Its function is presumed to be protective, as it lowers dentin permeability. However, it masks the underlying dentin and interferes with attempts to bond dental material to the dentin.White Muscle Disease: A myodegeneration most frequent in calves and lambs whose dams have been fed during gestation or longer on feeds, especially legumes (FABACEAE), grown in certain areas where selenium is either deficient or unavailable in the soil. It has been recorded in many countries. It has been produced experimentally in several species of animals on low-selenium intake. A similar myopathy occurs naturally in goats, deer, foals, and dogs but proof of the etiology is lacking. (Merck Veterinary Manual, 5th ed)Plateletpheresis: The preparation of platelet concentrates with the return of red cells and platelet-poor plasma to the donor.United States Food and Drug Administration: An agency of the PUBLIC HEALTH SERVICE concerned with the overall planning, promoting, and administering of programs pertaining to maintaining standards of quality of foods, drugs, therapeutic devices, etc.Blood Cell Count: The number of LEUKOCYTES and ERYTHROCYTES per unit volume in a sample of venous BLOOD. A complete blood count (CBC) also includes measurement of the HEMOGLOBIN; HEMATOCRIT; and ERYTHROCYTE INDICES.Blood Coagulation Disorders: Hemorrhagic and thrombotic disorders that occur as a consequence of abnormalities in blood coagulation due to a variety of factors such as COAGULATION PROTEIN DISORDERS; BLOOD PLATELET DISORDERS; BLOOD PROTEIN DISORDERS or nutritional conditions.Hematocrit: The volume of packed RED BLOOD CELLS in a blood specimen. The volume is measured by centrifugation in a tube with graduated markings, or with automated blood cell counters. It is an indicator of erythrocyte status in disease. For example, ANEMIA shows a low value; POLYCYTHEMIA, a high value.Isoantibodies: Antibodies from an individual that react with ISOANTIGENS of another individual of the same species.Erythrocytes: Red blood cells. Mature erythrocytes are non-nucleated, biconcave disks containing HEMOGLOBIN whose function is to transport OXYGEN.Rh-Hr Blood-Group System: Erythrocyte isoantigens of the Rh (Rhesus) blood group system, the most complex of all human blood groups. The major antigen Rh or D is the most common cause of erythroblastosis fetalis.Tooth Root: The part of a tooth from the neck to the apex, embedded in the alveolar process and covered with cementum. A root may be single or divided into several branches, usually identified by their relative position, e.g., lingual root or buccal root. Single-rooted teeth include mandibular first and second premolars and the maxillary second premolar teeth. The maxillary first premolar has two roots in most cases. Maxillary molars have three roots. (Jablonski, Dictionary of Dentistry, 1992, p690)Blood Platelets: Non-nucleated disk-shaped cells formed in the megakaryocyte and found in the blood of all mammals. They are mainly involved in blood coagulation.Acute Lung Injury: A condition of lung damage that is characterized by bilateral pulmonary infiltrates (PULMONARY EDEMA) rich in NEUTROPHILS, and in the absence of clinical HEART FAILURE. This can represent a spectrum of pulmonary lesions, endothelial and epithelial, due to numerous factors (physical, chemical, or biological).Automatic Data Processing: Data processing largely performed by automatic means.Hemoglobins: The oxygen-carrying proteins of ERYTHROCYTES. They are found in all vertebrates and some invertebrates. The number of globin subunits in the hemoglobin quaternary structure differs between species. Structures range from monomeric to a variety of multimeric arrangements.Disease Transmission, Infectious: The transmission of infectious disease or pathogens. When transmission is within the same species, the mode can be horizontal or vertical (INFECTIOUS DISEASE TRANSMISSION, VERTICAL).Leukocytes: White blood cells. These include granular leukocytes (BASOPHILS; EOSINOPHILS; and NEUTROPHILS) as well as non-granular leukocytes (LYMPHOCYTES and MONOCYTES).Wounds and Injuries: Damage inflicted on the body as the direct or indirect result of an external force, with or without disruption of structural continuity.Retrospective Studies: Studies used to test etiologic hypotheses in which inferences about an exposure to putative causal factors are derived from data relating to characteristics of persons under study or to events or experiences in their past. The essential feature is that some of the persons under study have the disease or outcome of interest and their characteristics are compared with those of unaffected persons.Leukocyte Count: The number of WHITE BLOOD CELLS per unit volume in venous BLOOD. A differential leukocyte count measures the relative numbers of the different types of white cells.