The lethal effects of bleomycin and its derivative, peplomycin, were determined for HeLa S3 cells grown in multicell spheroids cocultured with human diploid fibroblasts. Both drugs were less effective for cells in spheroids than for cells grown exponentially in monolayers. However, HeLa cells from spheroids exposed to the drugs in single-cell suspension were more sensitive to the drugs than wer...

Vascular dysfunction has been reported in human cases of anthrax, in mammalian models of Bacillus anthracis, and in animals injected with anthrax toxin proteins. To examine anthrax lethal toxin effects on intact blood vessels, we developed a zebrafish model that permits in vivo imaging and evaluation of vasculature and cardiovascular function. Vascular defects monitored in hundreds of embryos e...

Anticoagulant rodenticides may pose a secondary poisoning hazard to non-target predators and scavengers because of the time-delay between ingestion of a lethal dose and death of a target rodent. We investigated some pre-lethal effects of an anticoagulant rodenticide on the behaviour of wild rats in cages and in enclosures. We found that social interactions shortened time to death, that most rat...

The specimens of Oreochromis niloticus were exposed to Malathion to determine the lethal concentration (LC50) value and effects of sub-lethal concentrations on haematological and biochemical parameters. The LC50 value was registered as 1.06 mg/l. Fishes exposed to sub-lethal concentrations (0.12, 0.23 and 0.46 mg/l) for 6 weeks revealed that the pesticide causes alterations in various blood par...

The sequence of events from the time of application of herbicidal concentrations of 2,4-dichlorophenoxyacetic acid until the death of the plant has been elucidated by the use of a variety of plants by numerous investigators (4, 5 and others). A number of papers concerning the action of nonherbicidal concentrations of the growth-regulator have appeared (1, 2, 6, 7) but few have endeavored to tra...

The pathological actions of anthrax toxin require the activities of its edema factor (EF) and lethal factor (LF) enzyme components, which gain intracellular access via its receptor-binding component, protective antigen (PA). LF is a metalloproteinase with specificity for selected mitogen-activated protein kinase kinases (MKKs), but its activity is not directly lethal to many types of primary an...

The sedge Cyperus iria, a common weed in rice, contains large amounts of the insect hormone (10R) juvenile hormone III (JH III). Given its widespread distribution in Asia and Africa, we examined the possibility that C. iria could be used as a safe, inexpensive, and readily available mosquito larvicide. Plants of varying ages were harvested and leaves tested for lethal effects on larvae of the y...

Cardiotoxic and lethal effects of Listeria monocytogenes hemolysin were studied in CD-1 mice injected with varying doses of hemolysin. Intravenous injection of 100 complete hemolytic units (CHU) caused 100% lethality within 4 to 5 min. Doses ranging from 40 to 50 CHU caused death of approximately 50% of the animals. Adrenergic blocking agents and antihistamine failed to protect mice against let...

Glyphosate (GLY) is a herbicide that is widely used in agriculture for weed control. Although reports about the impact of GLY in snails, crustaceans and amphibians exist, few studies have investigated its sub-lethal effects in non-target organisms such as the honeybee Apis mellifera, the main pollen vector in commercial crops. Here, we tested whether exposure to three sub-lethal concentrations ...