Response patterns and

Chronic animal studies of organophosphates are few in number, but those that do exist provide a useful base from which to draw toxicological insight. In rats and mice exposed orally to tricresyl phosphate for 2 years, endocrine effects were found in a dose-response pattern and hepatic effects were found. Ovarian interstitial hyperplasia was also observed but was not dose related. No chronic-duration MRLs could be derived because of the limited number of studies. Tricresyl phosphate, a component of certain hydraulic fluids, produced no evidence of carcinogenic activity in assays with rats and mice (NTP 1994). However, another component, tributyl phosphate, was associated with an increased incidence of bladder tumors in rats and mice (FMC 1994a, 1994b). 

Dhar S, Nygren P, Liminga G, et al. Relationship between cytotoxic drug response patterns and activity of drug efflux transporters mediating multidrug resistance. Eur J Pharmacol 1998 346(2-3) 315-322. 

Vaughn DW, Green S, Kalayanarooj S, Innis BL, Nimmannitya S, Suntayakom S, Endy TP, Raengsakulrach B, Rothman AL, Ennis FA, Nisalak A (2000) Dengue viremia titer, antibody response pattern, and virus serotype correlate with disease severity. J Infect Dis 181(l) 2-9 Wu SJ, Hanson B, Paxton H, Nisalak A, Vaughn DW, Rossi C, Henchal EA, Porter KR, Watts DM, Hayes CG (1997) Evaluation of a dipstick enzyme-linked immunosorbent assay for detection of antibodies to dengue virus. Clin Diagn Lab Immunol 4(4) 452-457... 

Harrison, T.A. and Scott, J.W. (1986) Olfactory bulb responses to odor stimulation Analysis of response pattern and intensity relationships. J. Neurophysiol., 56, 1571-1589... 

Henderson, P. R., Bakal, D. A., Dunn, B. E. (1990). Cardiovascular response patterns and speech A study of air traffic controllers. Psychosomatic Medicine, 52,27 1. 

As a result Clark went on to operate on a second patient who had been deaf for 17 years. He was able to show that the speech coding strategy was not unique to one person s brain response patterns, and that the memory for speech sounds could persist for many years after the person became deaf. 

Drug-Receptor Interaction. Figure 2 Relationships between affinity and efficacy with different agonist response patterns, (a) For partial agonists, differences in maximal responses between agonists relate to differences in efficacy. Differences in the location parameter of the concentration-response curve (potency) indicate differences in affinity, (b) For full agonists, differences in potency indicate differences in either affinity, efficacy or both. 

FIGURE 6-24 Response pattern of an amperometric sensor array for various carbohydrates. The array comprised carbon-paste electrodes doped with CoO (1), Cu20 (2), NiO (3) and Ru02 (4). (Reproduced with permission from reference 84.)... 

Phenomenological evidence for the participation of ionic precursors in radiolytic product formation and the applicability of mass spectral information on fragmentation patterns and ion-molecule reactions to radiolysis conditions are reviewed. Specific application of the methods in the ethylene system indicates the formation of the primary ions, C2H4+, C2i/3+, and C2H2+, with yields of ca. 1.5, 1.0, and 0.8 ions/100 e.v., respectively. The primary ions form intermediate collision complexes with ethylene. Intermediates [C4iZ8 + ] and [CJH7 + ] are stable (<dissociation rate constants <107 sec.-1) and form C6 intermediates which dissociate rate constants <109 sec. l). The transmission coefficient for the third-order ion-molecule reactions appears to be less than 0.02, and such inefficient steps are held responsible for the absence of ionic polymerization. 

The ability to predict runoff and water availability is critical to water resources planners. However, the complex non-linearities of the hydrologic cycle make this an extremely difficult process. Even where precipitation is fairly well known, runoff prediction is a non-trivial problem, as land surface response depends as much (or more) on precipitation patterns and timing as on precipitation amount. The historical record of monthly rainfall and inflow at the Serpentine Dam, near Perth, Western Australia, provides an illustration of this sensitivity (Fig. 6-11a and b). 

Various animals show spontaneous epilepsy or seizures that can be readily induced by sensory stimulation (see Jobe et al. 1991). Tottering mice display seizures that resemble absence attacks behaviourally, in their EEG pattern and response to drugs. DBA/2 mice show reflex seizures to audiogenic stimuli while photically-induced seizures can be obtained in the Senegalese baboon, Papiopapio, which are similar to generalised tonic-clonic epilepsy. 

Phytoestrogens may elicit their biological effects by binding to estrogen receptors (ERs). Until recently, only a single ER isoform, ERa, had been identified however, a second receptor termed ERp has also been identified (Enmark et al, 1997, 1999 Saunders et al, 2000, 2001). It has been shown that the ERs have different intracellular and tissue distribution patterns and are responsible for different biological effects (see Table 5.1). A number of spliced variants of both ERa and ERp have also been identified (Inoue et al, 2000 Ogawa et al, 1998 Vladusic et al, 1998). 

Water-soluble root exudates are most frequently collected by immersion of root systems into aerated trap solutions for a defined time period (Fig. 1 A). The technique is easy to perform and permits kinetic studies by repeated measurements over time using the same plants. While it is possible to get a first impression about qualitative exudation patterns and even quantitative changes in response to different preculture conditions, the technique also includes several restrictions that should be taken into account for the interpretation of experimental data. 

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