Biological inhibition

Cellulases can also be eliminated fiom a mixture with xylanases by selective thermal inactivation. Cellulases are more thermolabile than xylanases in tiie cdlulolytic systems of the fungus Y-94 (79), T. harzianum 20), and Tkermoascus aurantiacus (77), but not in the Trickoderma reesei system (Biely, P. and Vrsanska, M., Slovak Academy of Sciences, Bratislava, unpublished results). Since cellulase thoixud inactivation causes a significant loss of xylanase also, a more convenient way to eliminate cellulase activity is by selective chemical or biological inhibition or inactivation. There appear, however, to be no reports on the existence of natural inhibitors that would be specific for cellulases. Such inhibitors of amylases and pectinases are known to occur in plants (27). 

At 3 and 6% by vol. industrial waste combination, slight to no biological inhibition was caused either to the fixed-film or activated sludge system. The results of sample analysis from the inhibitory runs showed that in two of the three cases, the possible cause of inhibition was the... 

Camptothecin, a quinoline alkaloid from Camp-totheca acuminata (Nyssaceae), is derived from strictosi-dine through stiictosamide (Fig. 41). Originally isolated in 1966, it biologically inhibits topoisomerase I, and in 1996, two derivatives, topotecan and irinotecan, were approved for the treatment of ovarian cancer and colon cancer, respectively. Other derivatives are in clinical trial. 

Substances which act in a biologically inhibiting or toxic manner must be rendered inactive. If the elimination of such substances also brings about... 

Koch R, Williamson ML, and Donnell GN (1966) A cooperative study of two methods for phenylalanine determination McCaman-Robins fluorimetric and micro-biologic inhibition methods. Journal of Pediatrics 68 905-911. 

Prepare the aqueous waste for biological treatment by removing excessive load or components that will inhibit the biological processes. 

There are, indeed, many biological implications that have been triggered by the advent of fullerenes. They range from potential inhibition of HIV-1 protease, synthesis of dmgs for photodynamic therapy and free radical scavenging (antioxidants), to participation in photo-induced DNA scission processes [156, 157, 158, 159, 160, 161, 162 and 163]. These examples unequivocally demonstrate the particular importance of water-soluble fullerenes and are summarized in a few excellent reviews [141, 1751. 

The number of known cytokines, as well as the diversity of biological functions, have led to a very complex and often confusing picture of the immunologic and nonimmunologic processes involved. The role of cytokiaes in local or systemic homeostatic mechanisms related to physiological functions may be utilized therapeutically for treatment of cancer and a variety of other diseases (2). Pharmaceutical research and development efforts surrounding lL-1 are typical examples of the cytokine inhibition approach to chronic inflammation research (2). 

Biological activities also may correlate with electronic substituent factors alone, eg, the inhibition of acetylcholinesterase by six diethyl phenyl phosphates (36) gave r = 0.95 for... 

Enzyme Inhibition. Some materials produce toxic effects by inhibition of biologically vital enzyme systems, leading to an impairment of normal biochemical pathways. The toxic organophosphates, for example, inhibit the cholinesterase group of enzymes. An important factor in thek acute toxicity is the inhibition of acetylocholinesterase at neuromuscular junctions, resulting in an accumulation of the neurotransmitter material acetylcholine and causing muscle paralysis (29) (see Neuroregulators). 

In general, penicillins exert thek biological effect, as do the other -lactams, by inhibiting the synthesis of essential structural components of the bacterial cell wall. These components are absent in mammalian cells so that inhibition of the synthesis of the bacterial cell wall stmcture occurs with Htde or no effect on mammalian cell metaboHsm. Additionally, penicillins tend to be kreversible inhibitors of bacterial cell-wall synthesis and are generally bactericidal at concentrations close to thek bacteriostatic levels. Consequently penicillins have become widely used for the treatment of bacterial infections and are regarded as one of the safest and most efficacious classes of antibiotics. 

---