A Streptomyces lusitanus DMZ-3 strain with potential to synthesize both insoluble and soluble melanins was detected. Melanins are quite distinguished based on their solubility for varied biotechnological applications. The present investigation reveals the enhanced production of insoluble and soluble melanins in tyrosine medium by a single culture. Streptomyces lusitanus DMZ-3 was characterized ...

2,3,7,8-Tetrachlorodibenzo-p-dioxin (T'CDD) is reported to be one of the most toxic chemicals known. There has been variation in such reported toxic parameters as single oral LD50 dose, range of time interval from dosing until death, and toxic manifestations which an animal exhibits (1-4). It seemed most appropriate, therefore, that the mean values and ranges of these and other general biologic...

Light-stick is a light attractor used in longline fishing which is often dumped or lost into the ocean after used, becoming a potential pollutant to marine organisms. In the present study, toxicity was evaluated by exposing Artemia to light-stick contents. The effects were observed on the survival of nauplii and hatchability of cysts. The LC50 was 0.063mLL−1 after 24h of exposure, whilst hatcha...

Mosquitoes that transmit human diseases are of major importance to the international public health community. Pesticides remain a major component of integrated programs to control these medically important species. However, very few types of pesticides are currently registered for mosquito control. A high-throughput screening method using first-instar larvae of Aedes aegypti was created and eva...

A new series of fused triazolo- and tetrazolopyrimidine derivatives 2-14 were synthesized and their anti-inflammatory and ulcerogenic activities were evaluated. The pharmacological screening showed that many of these obtained compounds have good anti-inflammatory activities, comparable to the reference drug. The toxicity of the compounds was also assayed via the determination of their LD50 valu...

Dear Editor, Acute toxicity of a drug can be determined by the calculation of LD50, i.e., the dose that will kill 50% of animals of a particular species. Recently, we reported the LD50 of thymoquinone, an active principle of Nigella sativa, in mice and rats by the method described by Miller and Tainter, 1944. Since then some post-graduate students and investigators have asked us to explain the ...

In Morocco, the resistance monitoring of Anopheles labranchiae larvae to temephos is done using discriminating concentration of 0.125 mg, which is half of the WHO recommended dose for Anopheles. However, this dosage seemed to be too high to allow an early detection of the resistance and its revision was found necessary. The present study was carried out during May-June 2008 and 2009 in nine pro...

Synthesis of 2-(2-hydroxy-3-amino)propyl derivatives of 4-alkoxy-6-methyl-1H-pyrrolo[3,4-c]pyridine-1,3(2H)-diones (24-35) is described. The chlorides used in the above synthesis exist mainly in the cyclic forms (18, 20-23). Only chloride with benzhydryl substituent at the nitrogen atom of piperazine has the chain structure (19). Among the studied imides the most active analgesics in the "writh...

Horn fly immatures were raised in media containing different concentrations of diflubenzuron in order to verify their susceptibility to this insect growth regulator (IGR). The 50% and 95% lethal concentrations of diflubenzuron for the population (LC50, LC95) were determined as well as the effect of this IGR on the different immature horn fly stages. The tests were performed using the progeny of...

Colonies of Trioxys pallidus Haliday (Hymenoptera: Aphidiidae) were collected from California walnut orchards during 1985-86 and screened for variability of responses to azinphosmethyl. Variability was found and laboratory selection was initiated with four colonies. All colonies responded to selection; after 7 to 12 selections, three colonies were combined (Select colony) and selection was cond...