Blood components

Whole blood is seldom used ia modem blood transfusion. Blood is separated into its components. Transfusion therapy optimizes the use of the blood components, using each for a specific need. Red cell concentrates are used for patients needing oxygen transport, platelets are used for hemostasis, and plasma is used as a volume expander or a source of proteins needed for clotting of the blood. 

Table 1. Hematological Values of Human Blood Components...

Blood components are also collected through apheresis. In apheresis, advanced blood cell separators are used to collect one or more specific blood components from a donor. The cell separators collect blood iato a separation chamber, isolate the desired blood components, and return the blood components not needed to the donor. This procedure is performed on-line within one sterile disposable tubiag set. The two principal components collected through apheresis are plasma and siagle-donor platelets (SDP). 

Primary blood components iaclude plasma, red blood cells (erythrocytes), white blood cells (leukocytes), platelets (thrombocytes), and stem cells. Plasma consists of water dissolved proteias, ie, fibrinogen, albumins, and globulins coagulation factors and nutrients. The principal plasma-derived blood products are siagle-donor plasma (SDP), produced by sedimentation from whole blood donations fresh frozen plasma (FFP), collected both by apheresis and from whole blood collections cryoprecipitate, produced by cryoprecipitation of FFP albumin, collected through apheresis and coagulation factors, produced by fractionation from FFP and by apheresis (see Fractionation, blood-plasma fractionation). 

Each type of blood cell has its own distribution of mass densities (Fig. 2). Most blood cell separators are based on the formation of blood components into layers by density gradient only. Some cell separators, ie, Haemonetics MGS, apply methods based on a combination of mass density and cell size. 

Fig. 2. Mass density distribution of blood components A, platelets B, monocytes C, lymphocytes D, basophils E, neutrophils F, erythrocytes and G,...

A small (25-kg), portable apheresis system, available in 1993, is designed to meet a wide variety of blood cell separation needs. The role of the apheresis system is to control the behavior, separation, and collection of blood components from the bowl while maintaining maximum donor safety. The system controls the flow rates of blood and components through variable pump speeds. It directs the flow of components out of the bowl, by fully automatic opening and closing of valves based on the output of the system sensors. The system monitors the separation of blood components in the bowl by an optics system that aims at the shoulder of the bowl. A sensor on the effluent line monitors the flow of components out of the bowl. 

Each blood component has specific storage requirements in terms of optimal temperature, additives, expiration, and storage containers. Red blood cells (RBC) from whole blood, provided in 200 mL units, have an expiration of 42 days. Fro2en, deglycerolized RBC, in 170 mL containers, and washed red cells, in 200 mL containers, both expire 24 hours after thawing and washing, respectively leukocyte-reduced RBC, in 200 mL containers, are viable for 24 hours. 

Full details of this work were pubHshed (6) and the processes, or variants of them, were introduced in a number of other countries. In the United States, the pharmaceutical industry continued to provide manufacturing sites, treating plasma fractionation as a normal commercial activity. In many other countries processing was undertaken by the Red Cross or blood transfusion services that emerged following Wodd War II. In these organisations plasma fractionation was part of a larger operation to provide whole blood, blood components, and speciaUst medical services on a national basis. These different approaches resulted in the development of two distinct sectors in the plasma fractionation industry ie, a commercial or for-profit sector based on paid donors and a noncommercial or not-for-profit sector based on unpaid donors. 

Histamine in the Blood. After its release, histamine diffuses rapidly into the blood stream and surrounding tissues (12). Histamine appears in blood within 2.5 min after its release, peaks at 5 min, and returns to baseline levels by 15 to 30 min. In humans, the diurnal mean of plasma histamine levels is 0.13 ng/g. In urine, elevations of histamine or metaboUtes are more prolonged than plasma elevations. Consequendy, abnormahties are more easily detected by urinary histamine assay. About one-half of the histamine in normal blood is in basophils, one-third in eosinophils, and one-seventh in neutrophils the remainder is distributed among all the other blood components. Increases in blood histamine levels occur in several pathological... 

Center for Biologies Evaluation and Research (CBER). This center is responsible for the regulation and approval of ah biological products intended for use in the treatment, prevention, or cure of diseases or injuries to humans. A biological product is any vims, therapeutic semm, toxin, antitoxin, vaccine, blood or blood component or derivative, or analogous product (5). It also includes products produced by biotechnology, such as interferons and erythropoietins. 

Parliament and of the Council of 27 January 2003 setting standards of quality and safety for the collection, testing, processing, storage and distribution of human blood and blood components and amending Directive 2001/83/EC Amended by Commission Directive 2003/63/EC of 25 June 2003 amending Directive 2001/83/EC of the European Parliament and of the Council on the Community code relating to medicinal products for human use... 

Cytokines (e.g., interferons Blood and blood components (e.g., albumin. 

General Requirements for Blood, Blood Components and Blood Products Additional Standards for Human Blood and Blood Products Additional Standards for Diagnoshc Substances for Laboratory Tests Additional Standards for Miscellaneous Products... 

In the area of drug targeting, there needs to be continuing emphasis on understanding the interaction between polymeric particles and biological systems such as blood components, cell types (e.g., phagocytes), and cell receptors. 

The Newborn and the Laboratory. The wellbeing of the pre-mature infant can be ascertained by measuring blood pH, electrolytes and other blood components on a routine basis. The maintenance of these infants electrolyte balance and normal pH is shown in Figure 3. An infant placed on a high protein diet milk formula developed an acidosis, and when brought to normal pH... 

Natelson, S. Penniall, R. Crawford, W. L. and Munsey, F. A. Noncasein protein to casein ration of feeding formulas. Effect on blood component levels in normal infants. Am. J. Dis. Child. (1955), 89,... 

In Section 24.3, use of electrosorption for effluent purification was mentioned. The same principle of an electrochemically controlled hemosorption (sorptive blood purification) is used in modem toxicology to extract toxins from blood. By appropriate potential control of the carbon sorbent, particular toxins can be removed selectively without traumatizing the blood, that is, without removing essential blood components such as the thrombocytes. 

Ross, R (1981). Atherosclerosis a problem of the biology of arterial wall cells and their interactions with blood components. Arteriosclerosis 1, 293-311. 

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