Colloidal systems blood

A lot of natural as well as technological objects of analytical control are colloidal systems, i.e. human blood, biological liquids, sol and suspension forming in different technological processes (ore-dressing, electrochemical deposition, catalysis and other), food, paint-and-lacquer materials, sewage water and other. 

SYNERESIS. The contraction of a gel with accompanying pressing out of the interstitial solution or serum. Observed in the clotting of blood, with silicic arid gels. etc. See also Colloid Systems. 

PPD induces one of the most severe edema both in humans and animal studies. The edema appears to be grossly specific and selectively localized in the head and neck. It was suggested that the toxic effect of the PPD might be produced by the conversion of the PPD on mucus surfaces to its oxidation product quinondi-mine, which is responsible for intense local irritation [13]. Some authors believed that PPD toxicity is due to some effect either on the blood colloids or on vascular permeability [15]. Also it was believed that the PPD toxicity is due to altered vascular permeability and involvement of the parasympathetic nervous system [13]. Deamination and formation of analine is claimed to be responsible in part for the toxic symptoms [12]. These different views as to the cause of PPD edema appear to be due to the fact that the exact number and nature of the oxidation products is not known [14]. 

Colloidal systems exist in both nature and industry and can consist of either solids or liquids dispersed in either fluids or gases. Blood is a dispersion of the red blood cells (which are similar to self-assembling colloids) in serum and emulsions or microemulsions (see Chapter 8) are dispersions of oil in water or water in oil. Fog, mist, and smoke are dispersions of small particles in gases, while pollution control deals with dispersions of solid particles in air. Foams (dispersion of liquid in a gas at relatively high volume fractions of liquid) are familiar from toothpastes to beer. Many industrial processes make use of colloidal dispersions of solid particles in fluids to tailor the hydrodynamic properties of the fluid or sometimes to produce a system with large amount of internal surface area for catalytic applications. 

Cytoplasm, blood, saliva, milk, and other biofluids, margarine, fruit juices, mayonnaise, bread, beer foam and whipped cream, pesticides, soils, pharmaceutical and cosmetic creams and lotions, paper, paint and ink, detergents, lubricants, and so on and so forth, are colloidal systems. 

Colloidal systems occur everywhere—in soils, seawater, foodstuffs, pharmaceuticals, paints, blood, biological cells, and microorganisms. Colloids and Interfaces in Life Sciences and Bionanotechnology, Second Edition, an expanded and updated version of Colloids and Interfaces in Life Sciences, gives a concise treatment of physicochemical principles determining interrelated colloidal and interfacial phenomena. 

Colloids, or, more generally, colloidal systems, are made of an ensemble of individual or integrated components with dimensions ranging between a nanometer (10 m) and a micrometer (10 m). Colloidal systems occur everywhere in the world around us—in soils, seawater, foodstuff, pharmaceuticals, paints, blood, biological cells, microorganisms, and so on. Because of their small dimensions, colloids represent a large surface area and, consequently, interfacial properties often determine colloidal behavior. The sciences of colloids and interfaces are therefore intimately related. 

Until the middle of the nineteenth century colloidal systems were regarded as being outside the realm of well behaved chemical systems because they did not behave in a manner expected of an aqueous solution. Such physico-chemical properties of colloidal solutions as the exhibition of osmotic pressure, electrolytic conductance, lowering of vapour pressure, elevation of boiling point, depression of freezing point etc. were different. Howwer, colloids must constitute extremely well behaved systems because life is a manifestation of various colloidal states. All protoplasm is in colloidal form. Most of the biologieal fluids, notably blood, lymph, milk, bile, and digestive secretions are colloidal solutions. Moreover, the biomembranes may themselves be considered to be a manifestation of the colloidal state. 

Properties of Colloidal Systems.—Colloidal solutions resemble true solutions in that they exert an osmotic pressure and have a lower freezing point than that of the solvent. Neither effect is as marked as in the true solution owing to the relatively greater size and smaller concentration of the dispersed particles. The osmotic pressure of the plasma proteins, however, is an important factor in maintaining the volume of blood, and in man has a normal value of 305-307 mm. HjO (0-03 atmospheres) at 22° C. In addition to these general properties, colloidal sj tems, especially suspensoids, exhibit special properties due to the surface and surface charge of the dispersed particles. These properties are —... 

Since the preparation of this edition has required the re-writing of about three-quarters of the entire book, it hardly seems necessary to specify more than the principal alterations. Solutions and Colloidal Systems, Steroids, Pigments (Pyrrole Derivatives, Caro-tinoids, Flavins), Tissue Respiration, and Internal Environment are now made the subject of special chapters. New analytical methods include the citrulline reaction for proteins and the diffusion test for acetone. Owing to the kindness of Dr. E. J. King I have been able to reprint three of his micro-methods for blood analysis. 

---