A competitive indirect enzyme-linked immunosorbent assay (ciELISA) for the organophosphorus insecticide acephate, O,S-dimethyl acetylphosphoramidothioate, was developed using a polyclonal antibody. Five different haptens mimicking the analyte were synthesized and conjugated with the carrier proteins bovine serum albumin (BSA) and keyhole limpet hemocyanin (KLH) by the N-hydroxysuccinimide active ester and diazotization methods. Polyclonal antibodies raised against hapten−KLH conjugates in rabbits and hapten−BSA conjugates as coating antigens were screened and selected for the assay in the homologous and heterologous ELISA systems. The effects of various assay conditions such as detergent, organic solvents, pH, and preincubation of the mixture of the polyclonal antibody and the analyte on the sensitivity were evaluated. The IC50 value for acephate was 25 ng/mL in an optimized heterologous system using hapten-4−BSA as a coating antigen and a polyclonal antibody no. 8377 against hapten-1−KLH, showing the det...

Development of an Enzyme-Linked Immunosorbent Assay for the Detection of the Organophosphorus Insecticide Acephate

In discussing the physiology of lactation, the following terminology introduced by Folley and his co-workers (Folley, 1947 b, 1949; Cowie, Folley, Cross, Harris, Jacobsohn, and Richardson, 1951; Cowie, Folley, and Richardson, 1954) will be adopted. This terminology has made an important contribution to our understanding of the subject because it separates two distinct processes -a) milk secretion and s) milk removal.

The Milk-Ejection Reflex and the Actions of Oxytocin, Vasopressin and Synthetic Analogues on the Mammary Gland

Throughout the history of pharmacology the exploration of antagonism and the use of antagonists has played an important role both in the development of theoretical concepts and interpretations and in experimental practice. The use of antagonists to interfere with the physiological or pathological effects of endogenous mediators forms an important branch of rational drug therapy. The first synthesis of a peptide hormone — oxytocin — by du Vigneaud and his coworkers (1953) opened the way to structurally modified synthetic hormone analogues including, it was reasonable to hope, antagonists of the natural hormones. Moreover, synthesis made available unexceptionably homogeneous preparations of the individual hormones, thereby eliminated some of the uncertainties attaching to much of the earlier work with materials purified from natural sources, and in consequence stimulated extensive physiological and pharmacological studies including work on antagonism.

H D Law

Papers

Oxytocin and 4-glycine oxytocin.