Scorpion stings are the main cause of human envenomation in Brazil and, for the treatment of victims, the World Health Organization (WHO) recommends the use of antivenoms. The first step to achieve effective antivenom is to use a good quality venom pool and to evaluate it, with LD50 determination as the most accepted procedure. It is, however, time-consuming and requires advanced technical trai...

Benzimidazoles are the most commonly used anthelmintic drugs for the chemical control of sheep strongylidoses in Bulgaria. The intensive and not always proper application could be able to cause a reduction of their efficacy. To establish benzimidazole resistances among gastrointestinal strongylids, two in vitro assays were performed – Egg Hatch Assay (EHA) and Larval Development Assay (LDA). Th...

• Limit dose test – this is the preferred test when toxicity is expected to be low and lethality is unlikely at the limit dose. The limit dose must be adequate for assessment purposes, and it is usually 2000 mg/kg body-weight. • Full test: LD50-only test – this is the preferred test when an estimate of the median lethal dose is required but neither the slope of the dose response curve or the co...

BACKGROUND Acute toxicity means the ability of a substance to cause adverse effects within a short period following dosing or exposure, which is usually the first step in the toxicological investigations of unknown substances. The median lethal dose, LD50, is frequently used as a general indicator of a substance's acute toxicity, and there is a high demand on developing non-animal-based predict...

Ultraviolet (UV) radiations present in sunlight are a major etiologic factor for many skin diseases and induce DNA damage through formation of cyclobutane pyrimidine dimer (CPD). This study was conducted to determine the toxicological effects of different wavelengths (250, 270, 290, and 310 nm) and doses of UV radiation on cell viability, DNA structure, and DNA damage repair mechanisms in a PC1...

Naja sumatrana is the dominant cobra species in Malaysia, Singapore, Borneo, and Sumatra, and it does not have specific antivenom. The Haffkine antivenom has been advocated instead. This study aims to determine the efficacy of this antivenom against Naja sumatrana envenoming using a mouse model. Methods. Male Swiss albino mice were used. Intravenous LD50 was first determined separately for Naja...

The present study evaluated the dose-response effects of subacute exposure to sublethal doses of the organophosphorus (OP) chemical warfare nerve agent (CWNA) sarin (GB) on the operant behavior of guinea pigs. Dietary restricted guinea pigs, trained to respond for food under a progressive ratio (PR) schedule of reinforcement, were injected five times per week (Monday-Friday) for 2 weeks with fr...

BACKGROUND A number of studies published during the last 15 years showed the occurrence of insecticide resistance in Triatoma infestans populations. The different toxicological profiles and mechanisms of resistance to insecticides is due to a genetic base and environmental factors, being the insecticide selective pressure the best studied among the last factors. The studies on insecticide resis...

Using dialyzed allantoic fluid suspensions of meningopneumonitis virus, Crocker (1954) studied the ratio of numbers of virus particles, as determined by electron microscopy, to egg infectivity. He reported the number of particles per egg LDso to vary from 200 to 1000. Zahler and Moulder (1953) used the method of Gogolak (1953), in which stained virus particles are counted by light microscopy, t...

An amplified enzyme-linked immunosorbent assay (ELISA) for the detection of Clostridium botulinum complex neurotoxins was evaluated for its ability to detect these toxins in food. The assay was found to be suitable for detecting type A, B, E, and F botulinum neurotoxins in a variety of food matrices representing liquids, solid, and semisolid food. Specific foods included broccoli, orange juice,...