Several synthetic substances are used in agricultural areas to combat insect pests; however, the indiscriminate use of these products may affect nontarget insects, such as bees. In Brazil, one of the most widely used insecticides is imidacloprid, which targets the nervous system of insects. Therefore, the aim of this study was to evaluate the effects of chronic exposure to sublethal doses of im...

Three applications of the polyanion pentosanpolysulphate about 2 months before infection of mice with scrapie completely protected animals infected with up to 100 LD50, and considerably prolonged the lifespan of those infected with 100 to 10,000 LD50. The clinical diagnosis was confirmed by immunoblot analysis for the protein of scrapie-associated fibrils.

INTRODUCTION PATHOPHYSIOLOGY Hematopoietic Syndrome Gastrointestinal Syndrome Neurovascular Syndrome DETERMINANTS OF RADIATION EFFECTS ON HUMANS Lethality Curve Influence of Trauma on LD50 Effect of Clinical Support on the LD50 Dose Effect Curve CLINICAL ASPECTS OF THE US CRITICALITY EXPERIENCE Clinical Course of the Criticality Cases CURRENT TREATMENT OF ACUTE RADIATION SYNDROME Supportive Car...

To identify which RNA segments of the California serogroup bunyaviruses determine virulence, we prepared reassortant viruses by coinfecting BHK-21 cells with two wild-type parents, La Crosse/original and Tahyna/181-57 viruses, which differed about 30,000-fold in virulence. The progeny clones were screened by polyacrylamide gel electrophoresis to ascertain the phenotype of the M and S RNA segmen...

1. Inventory of methods currently available From the regulatory point of view, the main objective of acute toxicity testing is basically to classify chemicals according to their intrinsic toxicity as required by the EEC directive on classification, packaging, and labelling of dangerous substances (Council Directive 67/548/EEC and subsequent amendments). This requirement aims to protect public h...