Plasma, Extenders

Blood oxygenators Blood plasma Blood plasma extenders Blood proteins Bloodroot Blood serum... 

Dextran. This polysaccharide is produced from sucrose by certain species of l euconostoc (70). Dextran [9004-54-0] was the first commercial microbial polysaccharide. It was used as a blood plasma extender in the U.S. Army during the late 1940s and early 1950s. This program was discontinued in 1955. 

The above chemicals can be obtained by fermentation (qv) of other sugars. However, some compounds require sucrose as a unique feedstock. Examples are the polysaccharides dextran, alteman, andlevan, which are produced by specific strains of bacteria (48,54—56). Dextrans are used to make chromatographic separation media, and sulfated dextran derivatives are used as plasma extenders (41). Levans show promise as sweetness potentiators and, along with alteman, have potential as food thickeners and bulking agents in reduced-caloric foods (55,56) (see Carbohydrates). 

At another level, water-soluble polyphosphazenes are of interest as plasma extenders. In addition, specific polymers with pendent imidazolyl units have been studied as carrier macromolecules for heme and other iron porphyrins (structures and (44,45). (In structures M and the ellipse and Fe symbol represent heme, hemin, or a synthetic heme analog.)... 

There are large numbers of naturally occurring representatives, especially of pyrrole that include the important polypyrroles (porphyrins and corrins), and the nitropyrrole antibiotics such as pyr-rolomycins and pyrroxamycin. Derivatives of furan have been used as fungicides and A-vinylpyr-rolidone is an important monomer for the production of blood plasma extenders and for cosmetic applications. On account of the similarity in the pathways for the aerobic degradation of monocyclic furan, thiophene, and pyrrole, all of them are considered here. Anaerobic degradation of furans is discussed in Part 2 of this chapter. 

One of the most successful conjugate polymer systems was developed by Duncan and Kopecek (25). The polymer carrier used in their system is poly [N(2-hydroxypropyl) methacrylamide] a biocompatible polymer that was originally developed as a plasma extender. They have evaluated a number of polymer conjugated drugs for cancer chemotherapy with interesting results. The attachment of the drug is through a peptidyl spacer pendent to the polymer backbone. These peptides links are stable in aqueous media but are readily hydrolyzed intracellularly... 

Many of the coagulation factors measured by global coagulation tests have limited stability, and the time and temperature of storage of sample will affect their measurements. Concepts of analyte stability and half-life in plasma extend to markers measured by immunoassay. Markers of platelet activation are affected by artifactual activation in vitro upon collection of the blood specimen. This section will highlight some of the nonanalytical variables that, if uncontrolled, can lead to spurious results and thus affect the interpretation of laboratory data. 

Polysaccharides such as starch and vegetable gums have important pharmaceutical uses as excipients, binding agents for tablets, emulsifying agents and demulcents. Dextran finds employment as a plasma extender to maintain the osmotic pressure of blood. 

Therapeutic Function Plasma extender Chemical Name See structure Common Name -... 

Hammer RH (1995) Anticoagulants, Coagulants and Plasma Extenders. In Foye WO, Lemke TL, Williams DA (eds) Principles of Medicinal Chemistry. Waverly B1 PVt. Ltd., New Delhi, p 388... 

The ionization is achieved by a discharge between a cathode and an anode in which an exit hole is drilled. An intermediate electrode confines the discharge to a small region. The plasma extends through the anode aperture and the ions are extracted from the plasma surface by means of an extraction electrode. 

These bacterial polysaccharides have been considered to be slimes they are often in reality loose capsules that are produced extracellularly by the bacteria. It was found that low molecular weight L. mesenteroides NRRL B-512F dextran could be used as a blood plasma extender and was produced on a relatively large scale during the cold war , but also found uses as a gel-filtration material when cross-linked by epichlorohydrin to give a family of cross-linked dextrans [41]. 

Hydroxyethylation of starch, which is obtained from starch and ethylene oxide. This compound has been utilized in papermaking for sizing and coating, in textile manufacturing, and as a blood plasma extender. Hydroxypropylated starch has also practical applications. 

In typieal physiological conditions wherein the plasma volume gets diminished sharply, as in hypovolemic shock, the immediate replaeement tends to restore the blood pressure. The use of plasma-extenders in sueh eonditions to restore the blood pressure are not regarded as the true vasopressor drugs for obvious reasons as they fail to affeet vasoeonstriction. 

Safety considerations for products containing polymers are often related to the components of the products rather than the polymers, which are usually relatively safe ingredients. Protein polymers should be tested for sensitization however, such problems are not frequent for the types of protein hydrolysates used in hair care. Pure synthetic polymers (with no monomer contaminant) are generally mild ingredients of relatively low toxicity, one example being polyvinyl pyrrolidone originally used as a blood plasma extender in medicine. 

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