CANNON GROUP

Loewi s discovery led to a chain reaction which resulted in the rapid spread of the principle of chemical transmission to all the peripheral synapses in the autonomic nervous system, and to the discovery of chemical transmission from the somatic motor nerve to the skeletal muscles and from one neuron to another, first in the autonomic and then in the central nervous system (studies of Samoilov, the classical experiments of the Dale and Cannon groups, the investigations of Ecdes, and many others). Finally, the chemical theory was confirmed by modem experiments using the latest methods electron microscopy, histochemical methods, the microelectrode technique, and others ... 

The dehydration reaction leads by an Ea process to 8 and is promoted by the tertiary, benzylic nature of the OH group at Ce and its antiperiplanar trans relationship to the H atom at Csg. Furthermore, one of the cannonical forms of the enolizable 0-dicarbonyl system present at Cn and Cia has a double bond in the C ring. Thus, dehydration leads to aromatization of the C ring, and this factor must provide some of the driving force for the reaction. 

The only information available for humans exposed to chlordecone pertains to a study of intermediate-to-chronic occupational exposures (exact durations not recorded) of one group of individuals employed at a facility in Hopewell, Virginia. Chlordecone was manufactured in this facility for 21--22 months because of poor hygiene at the facility, exposure by all routes was likely. In addition, concomitant exposure to a precursor was possible. Several studies have been published to describe the toxicity in this human population (Cannon et al. 1978 Taylor 1982, 1985), and results of these studies will be considered here. These results pertain to the chronic-duration exposure also. No deaths were reported (Cannon et al. 1978 Taylor et al. 1978). Skeletal muscle biopsy was conducted on six workers who experienced adverse neurological clinical signs (such as tremors) as well as muscle weakness and incoordination (Martinez et al. 1978). Abnormal histological and biochemical indices were revealed in this tissue. Joint pain was also reported (Taylor 1982, 1985). 

Cannon, J.J. in "Computational Group Theory" Academic Press London, 1984 pp 145-83. 

More than 30 years ago it became apparent that sandstones of the Athabasca Basin in Saskatchewan are host to significant deposits of uranium. Previous work elsewhere, primarily in the Colorado Plateau (Cannon 1964) and the former Soviet Union (Kovalevsky 1972), had shown that plants are capable of accumulating high concentrations of U. Surveys near the eastern margin of the Athabasca Group revealed an area of... 

Central sp carbon nuclei of ketenimines [355, 356] resonate at 190-195 ppm, while the terminal sp2 carbons appear at 30 60 ppm, depending on the number of alkyl groups attached to them (a and ft effects). Shielding of the terminal carbon reflects a significant contribution of cannonical formulae with carbanionic carbons. 

Carbon-fluorine coupling constants of fluorobenzene and selected substituted derivatives are collected in Table 4.60 [402], Benzenoid JCF couplings are about 245+15 Hz. They depend on both type and position of the substituents Electron withdrawing groups increase while electron releasing ones decrease one-bond carbon-fluorine coupling in fluorobenzene, particularly when they are ortho and para to fluorine. These observations can be explained by cannonical resonance formulae which take ( + )- and (-)-M effects into account. The data of fluoroanilines (( + )-M) and fluorobenzaldehydes (( — )-M) provide typical examples (Table 4.60). 

The process of rigidification has been extended, especially by Cannon s group, to include a large series of cis and trans fused octahydrobenzo[f] and octahydrobenzo[g]quinolines. Cannon et al. (27) recently summarized this work. It is certainly clear that incorporation of dopamine into a rigid framework can alter both specificity and potency. However, suitable explanations for some of the observed activities are still lacking. For example, the octahydrobenzo[g]quinoline XV (R=H or n-propyl) is inactive in the renal DA- receptor (27). No one has so far been able to explain why this is so, although a receptor model is offered later is this paper which can accommodate this finding. 

Cannon et al. demonstrated the possibility of controlling the eliminations by the proper choice of a base (22,89). According to molecular models, it seemed that, concerning the hydrogens trans to the ammonium group at positions 4 and 7, the hydrogen at C-4 appeared less hindered to approach of a base than the one... 

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