Hassall

Hassall, K.A. (1990). A readable student text, particularly useful for the metabolism and mode of action of herbicides and fungicides. 

The following brief account identifies only major groups of herbicides not mentioned elsewhere in the text, and is far from comprehensive. Their mode of action is only dealt with in a superficial way. From an ecotoxicological point of view, there has not been as much concern about their sublethal effects upon plants as there has been in the case of mammals, and there has not been a strong interest in the development of biomarker assays to establish their effects. The major concern has been whether weeds, or nontarget plants, have been removed following herbicide application—a rather easy matter to establish as plants are fairly sedentary. For a more detailed account of herbicide chemistry and biochemistry, see Hassall (1990). 

Inhibition of electron These herbicides have Hassall (1990), 0... 

Distorted growth patterns 2,4-D, MCPA, CMPP, and Hassall (1990) ... 

Hassall, C. W., The Baeyer-Villiger oxidation of aldehydes and ketones. Organic Reactions. 9, 73-106, 1957. 

K.A. Hassall, The Biochemistry and Uses of Pesticides, second edition, VCH, Weinheim (1990). 

Purine nucleoside phosphorylase (PNP) deficiency engenders a combined immunodeficiency and neurologic abnormalities and is usually fatal in childhood (G4). Patients with PNP deficiency have profound lymphopenia and a small thymus with poorly formed Hassall corpuscles. Lymphocyte enumeration shows markedly decreased numbers of T cells and T-cell subsets, with normal percentages of B cells. Point mutations and a splicing mutation have been identified in some PNP-deficient patients (H4). 

Acknowledgments We wish to thank Nicola Koyama, Minna Lyons, Cathal O Siochru and Sanjeevani Perera for their help with participant recruitment Tom Heyes for his technical and laboratory expertise Christopher Hassall and Alexandra Wall for their assistance with data collection Jan Havlicek, Jane Hurst and Tristram Wyatt for helpful comments and advice on an earlier draft and the University of Liverpool for funding this work. 

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