Fluids, Body

The investigation of body fluids with respect to nutrient (essential) elements and toxic elements -which are challenging topics for analytical chemistry - include the determination of concentrations at the trace and ultratrace level. However, isotope variation and isotope effects (especially of lighter elements such as hydrogen, carbon, nitrogen, oxygen but also of iron and calcium) have also been studied.22 23 The most frequently applied mass spectrometric technique for the analysis of body fluids today, which fulfils all requirements and also results in accurate and precise data, is ICP-MS. 

Apart from the analysis of blood serum and urine, there are different applications of trace element analysis by ICP-MS, for instance on milk samples.24-28 

An accurate determination of copper and zinc traces in human serum samples from the International Measurement Evaluation Programme-17 launched by IRMM (Geel) has been made by isotope dilution TIMS.38 An analytical method for the multi-element determination of metals (Ti, V, Cr, Co, Ni and Mo) potentially released from dental implants and prostheses into human body fluids (in blood and urine) by ICP-MS (double-focusing sector field instrument and quadrupole instrument with octopole collision cell) for medical studies was developed in Sanz-Medel s group.39 The Cr and Co concentrations found in blood samples of patients with chromium-cobalt based alloy varied in the sub-p,gl 1 range and were not significantly higher than the basal levels found by other authors.40 

Biomonitoring of environmental and occupationally relevant trace and ultratrace metals (Al, Co, Cr, Cu, Fe, Mn, Ni, Pt, V and Zn) in human serum and urine was carried out using ICP-SFMS at different mass resolutions by Begerow et cd 41 Whereas the elements free from isobaric interferences (Cd, Mn, Pb, Pt and Tl) were measured at low mass resolution (ml Am = 300), the determination of Al, Co, Cr, Cu, Fe, Ni, V and Zn was performed in the medium mass resolution mode (m/Am = 3000).41 Trace metal concentrations (Al, Ba, Be, Bi, Cd, Co, Cr, Hg, Li, Mn, Mo, Ni, Pb, Sb, Sn, Sr, Tl, V, W and Zr) in serum and blood samples from patients with Alzheimer s disease and healthy individuals measured by ICP-SFMS were compared by et al42 An increment of Hg and Sn in serum, higher levels of Co, Li, Mn and Sn and lower levels of Mo in blood were found in Alzheimer s disease samples.42 

In clinical studies of trace elements in blood and serum using inorganic mass spectrometry, single element clinical applications dominate in the analytical literature 43 

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Sulfur is essential to life. It is a minor constituent of fats, body fluids, and skeletal minerals. 

Corticosteroids exhibit a wide range of physiological effects One important func tion IS to assist m maintaining the proper electrolyte balance m body fluids They also play a vital regulatory role m the metabolism of carbohydrates and m mediating the alter gic response... 

As we have seen in this chapter steroids have a number of functions in human physiology Cholesterol is a component part of cell mem branes and is found in large amounts in the brain Derivatives of cholic acid assist the digestion of fats in the small intestine Cortisone and its derivatives are involved in maintaining the electrolyte balance in body fluids The sex hormones responsible for mascu line and feminine characteristics as well as numerous aspects of pregnancy from conception to birth are steroids... 

In many applications in mass spectrometry (MS), the sample to be analyzed is present as a solution in a solvent, such as methanol or acetonitrile, or an aqueous one, as with body fluids. The solution may be an effluent from a liquid chromatography (LC) column. In any case, a solution flows into the front end of a mass spectrometer, but before it can provide a mass spectrum, the bulk of the solvent must be removed without losing the sample (solute). If the solvent is not removed, then its vaporization as it enters the ion source would produce a large increase in pressure and stop the spectrometer from working. At the same time that the solvent is removed, the dissolved sample must be retained so that its mass spectrum can be measured. There are several means of effecting this differentiation between carrier solvent and the solute of interest, and thermospray is just one of them. Plasmaspray is a variant of thermospray in which the basic method of solvent removal is the same, but the number of ions obtained is enhanced (see below). 

R. Walter and co-workers. Disturbances in Body Fluid Osmolality, American Physiological Society, Betbesda, Md., 1977, pp. 1—36. 

EIA was originally developed as a histological technique to localize specific ceUular sites using the specificity of an immunological reaction (23). The resulting fluorescent antibodies can be detected in animal tissues at levels as low as 1 /tg/mL of body fluid. Eluorophore-labeled antibodies have also been used widely for flow cytometry appHcations using fluorescein antibodies to cell surface markers to detect and quantify specific cells (24). 

Assay of Enzymes In body fluids, enzyme levels aie measured to help in diagnosis and for monitoiing treatment of disease. Some enzymes or isoenzymes are predominant only in a particular tissue. When such tissues are damaged because of a disease, these enzymes or isoenzymes are Hberated and there is an increase in the level of the enzyme in the semm. Enzyme levels are deterrnined by the kinetic methods described, ie, the assays are set up so that the enzyme concentration is rate-limiting. The continuous flow analyzers, introduced in the early 1960s, solved the problem of the high workload of clinical laboratories. In this method, reaction velocity is measured rapidly the change in absorbance may be very small, but within the capabiUty of advanced kinetic analyzers. 

After inorganic mercuric salts are absorbed and dissociated into the body fluids and in the blood, they are distributed between the plasma and erythrocytes. Aryl mercuric compounds and alkoxy mercuric compounds are decomposed to mercuric ions, which behave similarly. 

AletabolicFunctions. The chlorides are essential in the homeostatic processes maintaining fluid volume, osmotic pressure, and acid—base equihbria (11). Most chloride is present in body fluids a Htde is in bone salts. Chloride is the principal anion accompanying Na" in the extracellular fluid. Less than 15 wt % of the CF is associated with K" in the intracellular fluid. Chloride passively and freely diffuses between intra- and extracellular fluids through the cell membrane. If chloride diffuses freely, but most CF remains in the extracellular fluid, it follows that there is some restriction on the diffusion of phosphate. As of this writing (ca 1994), the nature of this restriction has not been conclusively estabUshed. There may be a transport device (60), or cell membranes may not be very permeable to phosphate ions minimising the loss of HPO from intracellular fluid (61). 

Florfenicol concentrations in tissues and body fluids of male veal calves were studied after 11 mg/kg intramuscular doses adininistered at 12-h intervals (42). Concentrations of florfenicol in the lungs, heart, skeletal muscle, synovia, spleen, pancreas, large intestine, and small intestine were similar to the corresponding semm concentrations indicating excellent penetration of florfenicol into these tissues. Because the florfenicol concentration in these tissues decreased over time as did the corresponding semm concentrations, it was deemed that florfenicol equiUbrated rapidly between these tissues and the blood. Thus semm concentrations of florfenicol can be used as an indicator of dmg concentrations in these tissues. 

To be biocompatible is to interact with all tissues and organs of the body in a nontoxic manner, not destroying the cellular constituents of the body fluids with which the material interfaces. In some appHcations, interaction of an implant with the body is both desirable and necessary, as, for example, when a fibrous capsule forms and prevents implant movement (2). 

J. Elkinton and T. Danowski, The Body Fluids, Williams Wilkins, Baltimore, Md., 1955. 

Body fluids are analyzed for T and T by a variety of radioimmunoassay procedures (31) (see Immunoassays). The important clinical parameter for estimating thyroid function, the protein-bound iodine (PBI), is measured as described in treatises of clinical chemistry. High performance Hquid chromatographic (hplc) methods have replaced dc (32,33). 

It is important to appreciate that the magnitude of the absorbed dose, the relative amounts of bio transformation product, and the distribution and elimination of metaboUtes and parent compound seen with a single exposure, may be modified by repeated exposures. For example, repeated exposure may enhance mechanisms responsible for biotransformation of the absorbed material, and thus modify the relative proportions of the metaboUtes and parent molecule, and thus the retention pattern of these materials. Clearly, this could influence the likelihood for target organ toxicity. Additionally, and particularly when there is a slow excretion rate, repeated exposures may increase the possibiUty for progressive loading of tissues and body fluids, and hence the potential for cumulative toxicity. 

Pharmacokinetic studies are designed to measure quantitatively the rate of uptake and metaboHsm of a material and determine the absorbed dose to determine the distribution of absorbed material and its metaboHtes among body fluids and tissues, and their rate of accumulation and efflux from the tissues and body fluids to determine the routes and relative rates of excretion of test material and metaboHtes and to determine the potential for binding to macromolecular and ceUular stmctures. 

The microbial assay is based on the growth of l ctobacillus casei in the natural (72) or modified form. The lactic acid formed is titrated or, preferably, the turbidity measured photometrically. In a more sensitive assay, l euconostoc mesenteroides is employed as the assay organism (73). It is 50 times more sensitive than T. casei for assaying riboflavin and its analogues (0.1 ng/mL vs 20 ng/mL for T. casei). A very useful method for measuring total riboflavin in body fluids and tissues is based on the riboflavin requirement of the proto2oan cHate Tetrahjmenapyriformis which is sensitive and specific for riboflavin. 

The discovery and biological properties of lincomycin (1, R = OH, R = H) were described ia 1962 (1). This antibiotic is active in vitro and in vivo against most of the common gram-positive pathogens. Resistance by Staphylococci is developed slowly ia a stepwise manner, based on in vitro serial subculture experiments, and its activity is not iafluenced by body fluids up to concentrations of 50% ia the assay medium (2). 

Clinical chemistry analy2ets ate automated instmments used for measuring concentrations of the various chemical constituents of blood or other body fluids. For a discussion of the related category of instmments used for the measurement of blood cell parameters, see Automated instruments, HEMATOLOGY. 

In the treatment of poisoning by lead or other metal ions, higher concentrations of chelant can be safely obtained in humans by administering Na2CaEDTA rather than Na EDTA. The metal ion is bound by displacing small amounts of Ca " that the body can tolerate. Use of Na EDTA would result in calcium chelation and thus serious depletion of calcium in the body fluids (44). Removal of iron in Cooley s anemia is accompHshed by using chelants that are relatively specific for iron (45). 

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