Body fluids chemical composition

Infected body materials must be sampled, if at all possible or practical, before the institution of antimicrobial therapy, for two reasons. First, a Gram stain of the material may reveal bacteria, or an acid-fast stain may detect mycobacteria or actinomycetes. Second, a delay in obtaining infected fluids or tissues until after therapy is started may result in falsenegative culture results or alterations in the cellular and chemical composition of infected fluids. 

The gross appearance (macrostructure) of a kidney is recognizable to most people, even those who have no detailed knowledge of mammalian physiology. Furthermore, many people would be able to state that the role of the kidneys is to excrete waste materials in the urine. What is less likely to be so widely appreciated is the importance and complexity of action of the kidney in regulating the chemical composition and volume of the body fluids, a key aspect of homeostasis. Receiving approximately 25% of cardiac output per minute, the kidneys are adapted to monitoring blood pressure. 

It may not be possible to detect GHB and related compounds with common urine or serum (body fluid) tests. In cases where an unused portion of the drug cannot be recovered, gas chromatography-mass spectrometry (a high-technology instrument that separates a chemical mixture and identifies its composition) can be used to detect GHB and related compounds from a sample of serum, plasma, blood, or urine. 

Forensic biochemists perform blood typing and enzyme tests on body fluids in cases involving assault, and also in paternity cases. Even tiny samples of blood, saliva, or semen may be separated by electrophoresis and subjected to enzymatic analysis. In the case of rape, traces of semen found on clothing or on the person become important evidence the composition of semen varies from person to person. Some individuals excrete enzymes such as acid phosphatase and other proteins that are seldom found outside seminal fluid, and these chemical substances are characteristic of their semen samples. The presence of semen may be shown by the microscopic analysis for the presence of spermatozoa or by a positive test for prostate specific antigen. 

Chemically bonded ceramics are more resorbable and surface reactive as compared to sintered counterparts. This is because they are more soluble within the body fluids as compared to the sintered ceramics. By controlling the composition, their solubility can be tailored to the desired value. 

Isotopic studies relating to nutrition and diet have originated from two diverse fields bio-medical research and archaeology Numerous studies have been reported by researchers in the areas of biochemistry and medicine using either isotopically enriched compounds or the natural variations in isotopic abundances Such studies usually involve a specific chemical as a tracer of biochemical pathways, and in these studies soft tissues or body fluids are analyzed Recent work in nutrition has begun to examine the isotopic composition of carbon in macronutrients in diets and their disposition in body tissues (1 2) The isotopic composition of hard tissue (i e bone) however has been largely ignored in biochemical studies ... 

Table 4 The chemical composition of diverse body fluids. Blank entries indicate that no data have been found to date in the literature. For entries where an average value and ranges are... 

The potential application of mPC-CE coupled to a mass spectrometer (mPC-CE-MS) in the clinical diagnosis of disease states is substantial. In part, this is due to the fact that the technique can be utilized in the direct analysis of any physiologically derived body fluid. This is demonstrated by the direct mPC-CE-MS analysis of aqueous humor obtained from a patient undergoing eye-surgery. The chemical composition of human aqueous humor is still poorly understood, mainly due to the limited sample amounts that can be collected. It has been suggested that the chemical content of this fluid may play a role in drainage of the human eye. In particular, the protein content of aqueous humor may contain important factors in this process. Hence, any method that can readily determine the protein content of aqueous humor would be of great benefit. 

Hendry, E.B. The osmotic pressure and chemical composition of human body fluids. Clin. Chem. 1962, 8, 246-265. 

Our environment has many examples of chemical equilibria. Even when systems are not in equilibrium, they are continuously changing in an effort to reach equilibrium. Equilibria control the composition of Earth s atmosphere, oceans, and lakes, as well as the composition of our body fluids. Even soot provides an example of an equilibrium. 

The kidneys regulate and maintain the constant optimal chemical composition of the blood and the interstitial and intracellular fluids throughout the body. The mechanisms of differential reabsorption and secretion, located in the tubule of a nephron, are the effectors of regulation. The mechanisms operate under a complex system of control in which both extrarenal and intrarenal humoral factors participate. 

Other control parameters included both chemical reactions and physical interactions (Figure 9). Variation of these properties caused a concomitant change in mechanical properties and water absorption. Such control eillows the composite to be "tailored to a specific use. This material can be easily fabricated and adapted to a number of different socket geometries while allowing bone growth into the porous material. Initial studies have shown that neither the biocompatibility of the material nor the resistance to body fluid diffusion are affected to a major extent by this crosslinking method. Long term implantation studies are presently underway to determine the ultimate effect of the material on the implant area. 

General Tissue-Fluid Interactions. The exact response of the body to any implant depends not only on the chemical composition of the implant but also on the form of the polymer (sheet, fiber, foam, etc.), the shape of the implant, whether the implant can move, and the location of the implant within the body. (Infection can also occur if proper sterilization techniques are not used.) The reaction of the body can vary from a relatively benign acceptance of the implant to an outright rejection of the material with an attempt, by the body, to extrude the implant and/or to destroy the implant by chemical means. Chemical destruction is usually... 

Due to the (recently) recognized importance of lipids, many different analytical methods to assess the composition of an unknown sample (e.g. an organic extract of a body fluid) are available. Based on the available information, all these techniques can be sorted into methods providing primarily (a) chemical or... 

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