Secondary change

FIGURE 15.7 Secondary changes in the total group composition of soluble organic matter as a result of simulated water washing extracts of the Miocene lignite and shale (both of the Bechatow open cast mine, Poland), the Upper Devonian shale (the Holy Cross Mountains, Poland), and the Upper Carboniferous bituminous coal (the Upper Silesia Coal Basin, Poland). 

Since cellular immunity results in the release of chemotactic lymphocytes that in turn enhance phagocytosis, a deficiency in cellular immunity may also result in chronic infections. Cellular immunity is mediated by T cells, macrophages, and NK cells involved in complex compensatory networks and secondary changes. Immunosuppressive agents may act directly by lethality to T cells, or indirectly by blocking mitosis, lymphokine synthesis, lymphokine release, or membrane receptors to lymphokines. In addition, cellular immunity is involved in the production and release of interferon, a lymphokine that ultimately results in blockage of viral replication (Table 15.4). Viruses are particularly susceptible to cytolysis by T cells since they often attach to the surface of infected cells. Thus, immunosuppression of any of the components of cellular immunity may result in an increase in protozoan, fungal, and viral infections as well as opportunistic bacterial infections. 

Both the inhaled and the intravenous anesthetics can depress spontaneous and evoked activity of neurons in many regions of the brain. Older concepts of the mechanism of anesthesia evoked nonspecific interactions of these agents with the lipid matrix of the nerve membrane (the so-called Meyer-Overton principle)—interactions that were thought to lead to secondary changes in ion flux. More recently, evidence has accumulated suggesting that the modification of ion currents by anesthetics results from more direct interactions with specific nerve membrane components. The ionic mechanisms involved for different anesthetics may vary, but at clinically relevant concentrations they appear to involve interactions with members of the ligand-gated ion channel family. 

Table 2.1.9 Changes of blood amino acids in various primary inherited defects and as a result of secondary changes. ASA Argininosuccinic acid, CPS carbamoyl phosphate synthase, LPI Lysinuric protein intolerance, MAD multiple acyl-CoA dehydrogenation, MSUD maple syrup urine disease, NAGS N-acetylglutamate synthase, NKH nonketotic hyperglycinemia, NTBC 2-(2-nitro-4-3 trifluoro-methylbenzoyl)-1,3-cyclohexanedione, OCT Ornithine carbamoyltransferase,...

During ripening, three primary biochemical events occur, glycolysis, lipolysis and proteolysis. The products of these primary reactions undergo numerous modifications and interactions. The primary reactions are fairly well characterized but the secondary changes in most varieties are more or less unknown. An overview of the principal biochemical changes follows. 

In establishing the character of a complex (or a double) salt, it is necessary to determine the nature and number of the constituent ions. It is usually simpler to determine if a given metal is in the positive or negative ion by investigating the changes of concentration of the liquid about the electrodes during electrolysis. Allowances have to be made for secondary changes. 

Uniformly, within this group of cations, perchlorate ion accompanying the transition-element cation is replaced by nitrate (7,31), thiocyanate (7,52), or halide (7,6). Nitrate is probably replaced by thiocyanate, but a secondary change takes place in many systems, which makes direct comparison difficult (see below). If one then makes the further reasonable assumption that solvent interference can be used as an inverse measure of tendency to bind to the central metal cations, thiocyanate, whose competition with alcohol is less efficient (52) than that of chloride (6), should be somewhat replaceable with chloride. Comparisons between chloride and thiocyanate in acetonitrile show also that the formation of a complex with a given anion/cation ratio takes place much more readily with chloride than with thiocyanate (55, 34). By the same criterion, from experiments in alcoholic solution (55), bromide should replace chloride, and an extrapolation of the behavior to iodide seems reasonable. 

Koporulin, V. I., Types of Secondary Change of the Sandstones and Gravel-ites of the Irkutsk Coal Basin, Izvest. AN SSSR, Ser. Geol. (1962) (3) 30-40. 

By extrapolation of the changes in the chemical shifts in the NMR spectrum of epi-inositol, the stability constant of the calcium complex has been calculated to be ca. 3M"1—i.e., about 70% of the cyclitol is present as a cationic complex in 1M calcium chloride solution. However, the extrapolation cannot be accurately carried out because there are secondary changes in chemical shifts caused by weaker complexing at two oxygen atoms. 

This method gives exact and concordant results, which are not obtained by direct incineration or other methods. Indeed, during direct combustion and incineration of the bread, reactions occur between the sodium chloride and the natural components of the bread which result in the evolution of hydrochloric acid and other secondary changes leading to marked alteration of the final results. 

Tucker MJ (1999) Pituitary Toxicology Direct Toxicity, Secondary Changes and Effects on Distal Target Tissues. In Harvey PW, Rush KC, Cockbum A (eds) Endocrine and Hormonal Toxicology. John Wiley Sons, England, pp 15-32... 

Reisine T, Bell GI (1995) Molecular biology of somatostatin receptors. Endocrine Reviews 16 427 Trainer PJ, Holly J, Medbak S, Rees LH, Besser GM (1994) The effect of recombinant IGF-I on anterior pituitary function in healthy volunteers. Clin Endocrinol (Oxf) 41 801 Tucker MJ (1999) Pituitary Toxicology Direct Toxicity, Secondary Changes and Effects on Distal Target Tissues. In Harvey PW, Rush KC, Cockburn A (eds) Endocrine and Hormonal Toxicology. John Wiley Sons, England, pp 15-32... 

The biosynthesis of extractives is controlled genetically and hence each wood species tends to produce specific substances. As a result of secondary changes, heartwood contains a large variety of phenolic substances. From the chemotaxonomical point of view, chemical structures of various flavonoids, lignans, stilbenes, and tropolones are of interest. For example, species within genera such as Pinus, Acacia, and Eucalyptus can be classified according to their characteristic composition of phenolic substances. 

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