The acute oral LD50s of several inorganic arsenicals are listed in Table 23. Trivalent inorganic arsenic is generally more toxic than pentavalent inorganic arsenic. The oral LD50 of As2O3 (As2O3), a trivalent arsenical, administered to three strains of mice, ranges from 26 to 36 mg As/kg body weight (Harrison et al., 1958; Kaise et al., 1985). Because of the low solubility of As2O3 in water, Ha...

Aedes aegypti (L.) (Diptera: Culicidae) is the primary vector of both dengue and yellow fever. Use of insecticides is one of the primary ways to control this medically important insect pest. However, few new insecticides have been developed for mosquito control in recent years. As a part of our collaborative effort to search for new insecticides to control mosquitoes, piperidine was used as bas...

The aim of this study was to determine the effect of acute intoxication with chlorfenvinphos on the liver reduced glutathione (GSH) level and the activities of two enzymes involved in glutathione metabolism, as well as the activity of catalase (CAT), glucose-6-phosphate dehydrogenase (G6PDH) and the level of liver hydrogen peroxide. The concentration of malondialdehyde (MDA) was determined as l...

Infection with Escherichia coli O157:H7 may develop into hemorrhagic colitis, or hemolytic uremic syndrome (HUS), which usually causes kidney failure or even death. The adhesion and toxins are the important virulent factors. In this study, a novel vaccine candidate rSOBGs was constructed based on the bacterial ghost (BG). rSOBGs maintained the integrity of cellular morphology and displayed the ...

A gel bait-resistant German cockroach, Blattella germanica (L.), strain Cincy was collected in Cincinnati, OH. This strain exhibited a high level of behavioral resistance to Avert (0.05% abamectin) and Maxforce FC (0.01% fipronil) gel baits. Topical application assays indicated moderate levels of physiological resistance of the Cincy strain to abamectin and fipronil. Resistance ratios (based on...

This study tested susceptibilities of Anopheles minimus mosquitoes to deltamethrin during each of 19 generations (although technical problems excluded selective pressure experiments during generations 11-13). The ultimate goal was to establish a pyrethroid resistant colony of this important malaria vector in Thailand. Resistance was selected for by exposing, using the World Health Organization ...

1. OECD guidelines for the Testing of Chemicals are periodically reviewed in the light of scientific progress or changing assessment practices. The concept of the up-and-down testing approach was first described by Dixon and Mood (1)(2)(3)(4). In 1985, Bruce proposed to use an up-and-down procedure (UDP) for the determination of acute toxicity of chemicals (5). There exist several variations of...

The effects of DEHP on sperm morphology and on peripheral blood micronuclei were studied for 12 weeks following five subacute IP injections of DEHP at 1/6, 1/12, and 1/60 of the LD50 per day. Sperm morphology was examined in both adult mice and rats, while peripheral blood micronuclei were scored in mice up to 4 weeks after treatment. In mice, DEHP at 1/6 LD50 significantly depressed body weigh...

Six laboratory experiments were carried out to investigate the effect of the fungicide Benomyl on pure cultures of some plant growth promoting bacteria (PGPB) and some fungi. The highest LD50 was recorded for Bacillus circulans and proved to be the most resistant to the fungicide, followed by Azospirillum braziliense, while Penicillium sp. was the most affected microorganism. LD50 values for th...

Present study was undertaken to determine the median lethal dose (LD50) of β-cyfluthrin (β-cyf), a synthetic (type II) pyrethroid pesticide in male and female Swiss albino mice. The calculation of LD 50 is an initial screening step in the assessment and evaluation of the toxic characteristic of a chemical substance. The selected single doses of β-cyfluthrin based on the pilot study were 200, 22...