THE INSECTICIDES—Their Hazard in Industry and in the Home Part II—Clinical Aspect

Within the past decade the chemist has evolved a new group of insecticides having a greater range of toxicity to insects—and to man. Since their use is ubiquitous, it is imperative that information be widely disseminated regarding proper cautionary measures as well as the early signs and symptoms of toxicity.     

The life stages and population dynamics of an arid zone scorpion Urodacus yaschenkoi (Birula 1903)

The arid zone scorpion Urodacus yaschenkoi (Birula 1903) is shown to have six instars. Instars can be recognized by measuring the claws and the carapace plus first five tail segments. A population study, carried out at Coombah, NSW, showed that the life history consisted of mating in September–October, 18 month gestation, birth in February-March, moult to second instar March-April and annual moults to sixth instar in December–February. The minimum generation time was 6 y, and the population appeared to be stable. The calendar of catches method was used to determine the population size (about 400 animals in 2240 m²) but required some extra assumptions to cope with loss of marks from individuals when they moulted.     

The formation of L-3-phosphoglyceric acid by ribulose-1,5-bisphosphate carboxylase

A sensitive and reliable method to determine the stereochemical composition of 3-phosphoglyceric acid is presented. Results obtained with this method show that 3-phosphoglyceric acid formed in the ribulose-1,5-bisphosphate carboxylase reaction is a mixture of 10% L-3-PGA and 90% D-3-PGA.     

Neuroleptic-like electroencephalographic changes in schizophrenics through biofeedback

Nine schizophrenic patients participated in a study which explored whether EEG feedback techniques could effect changes in the EEG similar to those associated with neuroleptic-induced improvement. During five sessions, each patient was presented feedback signals which continuously refected the discrepancy between characteristics of the patient's EEG power spectral profile and spectral profile characteristics associated by past research with neuroleptic induced clinical improvement. Significant within-session changes were observed for two of three EEG power spectrum bands of interest. No significant session-to-session EEG changes were observed. The results suggest that the EEG of schizophrenics can be temporarily altered, using feedback techniques, in a way that mimics the EEG changes that have been shown to occur with neuroleptic induced clinical improvement.The authors are indebted to Turan M. Itil, John W. Fredrickson, Michael Madwed, and Irene B. Francis. Senior authorship is shared equally.     

Position of the amino terminus of myosin light chain 1 and light chain 2 determined by electron microscopy with monoclonal antibody

The position of the N terminus of myosin light chain 1 (LC1) and myosin light chain 2 (LC2) of rabbit skeletal muscle was mapped on the myosin head with a monoclonal antibody (SI304), which recognized the amino acid sequence N-trimethylalanyl-prolyl-lysyl-lysyl at the N terminus of LC1 and LC2. The complex of the antibody and myosin was observed by electron microscopy. By selective cleavage of the N terminus of LC1 or LC2 with papain or chymotrypsin, the position of the N terminus of LC1 and LC2 was determined separately. The N terminus of LC2 is located at the head-rod junction. The N terminus of LC1 is 11 nm (+/- 3 nm, standard deviation) from the head-rod junction. This position is near the actin-binding site of the myosin head.     

Comparative analysis of the HBsAg level in human blood preparations

A total of 218 batches of blood preparations produced from different raw materials have been studied by means of enzyme immunoassay kits (Abbott Laboratories, USA). The assays have revealed that the preparations under study are nonstandard with respect to the content and isolation rate of HBsAg, the marker of hepatitis B virus. These data necessitate search for the ways of improving the quality of blood preparations.     

Identification of the functional site of erythrocyte protein 4.1 involved in spectrin-actin associations

Peptides produced by mild chymotryptic digestion of human erythrocyte protein 4.1 mimic the ability of intact 4.1 to promote the binding of spectrin to F-actin. This complex-promoting activity was found to reside in an 8-kDa peptide which was fully functional when dissociated from other protein 4.1-derived peptides, indicating that noncovalent complexes of multiple peptides were not essential for activity. The 8-kDa peptide was incorporated into a ternary complex with spectrin and F-actin in approximately stoichiometric amounts. Amino acid composition and two-dimensional peptide mapping show that the 8-kDa active peptide is located within the 10-kDa region of protein 4.1 which contains a cAMP-dependent phosphorylated site.