Tissue preparation summary

Summary of Effects of Some Opioids in Isolated Tissue Preparations"... 

The current system terms prostanoid receptors P receptors, which is preceded by a letter to indicate the most potent natural prostanoid at that particular receptor (hence the receptor at which PGD, is the most potent natural agonist is called the DP receptor and so on). This system was based initially upon a rigorous quantitative comparison of the agonist potencies of each of the natural prostanoids in tissue preparations chosen to avoid the problems associated with multiple receptor types. In addition, being aware of the limitations of agonists in receptor classification (111), efforts were made to identify specific prostanoid-receptor antagonists. A summary of the current state of prostanoid receptor classification is shown in Table 6.2. 

Summary term for a number of steroid hormones and their precursors with differentiation-inducing activity in many tissues. As regards bone, three components are relevant cholecalciferol ( vitamin D ) 25-hydroxyvi-taminD3 (calcidiol) and 1,25-dihydroxy vitamin D3 (calcitriol). The latter is the biologically active form and increases both intestinal calcium absoiption and bone resorption. Vitamin D preparations are widely used for the treatment of osteoporosis. Daily supplementation with vitamin D reduces bone loss in postmenopausal women and hip fractures in elderly subjects. 

Although the metabolism of several phthalate esters has been studied in vitro, essentially all of the in vivo studies have involved DEHP. A summary of these experiments which involved exposure offish to aqueous - C-DEHP is presented in Table IV (11,12). Tissue C was isolated and separated into parent and the various metabolites by preparative thin layer chromatography on silica gel. Metabolites were hydrolyzed where appropriate and identified by gas chromatography-mass spectroscopy. In whole catfish, whole fathead minnow and trout muscle, the major metabolite was the monoester while in trout bile the major metabolite was the monoester glucuronide. The fact that in all cases the major metabolite was monoester or monoester glucuronide despite the differences in species, exposure level and duration, etc. represented by these data, suggests that hydrolysis of DEHP to monoester is important in the biotransformation of DEHP by fish. 

Analytical methods have been developed to measure benzene levels in exhaled breath, blood, and various body tissues. The primary method of analyzing for benzene in exhaled breath, body fluids and tissues is gas chromatography (GC) coupled with either flame ionization detection (FID), photoionization detection (PID), or mass spectrometry (MS). Rigorous sample collection and preparation methods must be followed when analyzing for benzene to prevent contamination of the sample. A summary of commonly used methods of measuring benzene in biological samples is presented in Table 6-1. 

In summary, for the determination of single OP compounds in blood or organic tissues, different GC methods in combination with various detection methods (MS, NPD, FPD) are used. For sample preparation, some authors prefer the traditional liquid-liquid extraction, others use SPE on conventional Cig materials. In addition to these methods, novel techniques... 

In addition to a tabular format for the determination of lindane in each of the myometrial tissue samples submitted, a method summary should be included. A one paragraph method summary serves to inform the reader as to how the samples were handled once they arrive in the analyst s laboratory. The summary should also provide a brief overview of the sample preparation and a brief description of the determinative technique used. The following report illustrates these concepts. 

In summary, preparation of tissues serves to enhance both the precision and the sensitivity of the RRA technique. Although general similarities in preparative procedures exist among assays, each RRA has been tailored to a specific purpose and the techniques established dunng the course of developing the assay should be adhered to with rigor... 

In order to minimize the risks of sensitizing recipients to exogenous proteins, it is desirable to prepare enzymes for replacement therapy from human sources. The first treatment by such means was that of a patient with Sandhoff-Jatzkewitz disease where hexosaminidase A was infused intravenously. This experiment demonstrated three major problems in the use of enzyme therapy. Firstly, the infused enzyme tends to concentrate in tissues such as the liver, and other affected tissues may accumulate little. Secondly, the enzyme is subject to rapid turnover so that the administered enzyme has virtually disappeared from the recipient after 24 h. Thirdly, the administered enzyme cannot pass the blood-brain barrier so that lipidoses with central nervous system impairment are untreatable by this means (Brady, 1977). Tay-Sachs disease and Fabry s disease have been treated by enzyme replacement with limited success (cf. Brady, 1978). Better results have been obtained in the treatment of Gaucher s disease. A beneficial effect has been observed and the results are of impressive duration. Moreover, a high-yield large-scale procedure is now available for the isolation of human placental gluco-cerebrosidase (cf. Brady, 1978, for summary of clinical trials). 

The CLA and 18 1 isomer composition in the milk and meat fat of ruminants is a mixture of numerous positional and geometric isomers, most of which are generated by specific rumen bacteria, or subsequently re-synthesized in tissues by specific enzymes. To understand their biosynthesis, with the aim of manipulating these biochemical processes, requires appropriate techniques to determine each of the individual isomers with confidence. Detailed chemical syntheses are presented in Chapter 3 to prepare appropriate standards Chapter 4 provides a summary of complementary gas-, adsorption-, and argentation-chromatographic techniques required for the analysis of all the CLA and trans- and af-18 l isomers Chapter 5 presents improved separations of the CLA isomers using modified silver ion and reverse phase HPLC techniques while Chapter 6 is devoted to a complete structural characterization of the methyl esters of CLA isomers using acetonitrile chemical ionization tandem mass spectrometry. 

The protocol presented here describes how to prepare collagen suitable for culturing embryonic and postnatal tissues and how to process it to make a three-dimensional gel in which tissue explants can be manipulated and embedded. The techniques used to isolate and embed tissue are described, as are the ways in which growth and differentiation factors can be presented to tissue explants within these gels. In addition, a summary is provided of the maimer in which such cultures can be manipulated to process by immunohistochemical or in-situ hybridization techniques to examine cell differentiation within tissue explants. 

In summary, for spectroscopic analysis of tissue samples, fresh or carefully prepared frozen tissue would be considered ideal, but FFPP tissue can be used successfully if deparaffinized using hexane. Other dewaxing agents and protocols can also be used successfully if the paraffin signals do not overlap with the spectral regions of interest. For analysis of cell samples, live cells would be considered ideal, but in cases where this is not possible or practical, fixed cells can be used. Formalin has been shown to provide good cellular preservation for spectroscopic analysis in many studies but some experimentation may be necessary to find the optimum fixative for each particular cell sample. For this optimization, fixed cell samples should be compared with live cell samples where possible. 

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