This study was performed at Hanoi University of Natural Sciences and National Institute of Malaria and Parasitology from April 2001 to May 2002. Biological trials on laboratory strains of An. dirus were carried out according to WHO/VCB/81.806; WHO/CDS/CPC/MAL/98.12 and WHO/VCB/89.981. Analyses were conducted by the method of fluid-fluid extraction with the solvent system of n-hexan. Fendona 10SC,Icon 2,5CS,K-othrin ISC, Imperator 50EC .soaked mosquito bednet had manifested insecticide effect. Their effect of killing An.dirus was maintained for 5 -6 months. The procedure of analysis of pyrethroide compounds in use for soaking mosquito bednet was established and the half live of 125-188 day long period for each compound was determined
Pyrethrins ; metabolism ; world health organization ;

Esfenvalerate is a kind of commonly used highly effective pyrethroid insecticide. It is common for people who are poisoned by contact or misuse, but rarely reported for people who are poisoned by intramuscular injection. This paper reports a case of intramuscular injection of esfenvalerate in the Department of Infection, West China Hospital of Sichuan University in November 2021. The patient was intramuscularly injected with about 20 ml of esfenvalerate, inducing the sense of swelling and tingling, degeneration and necrosis of striated muscle tissue at the injection site, also liver function damage and other manifestations. The patient was discharged from hospital after rehydration, accelerating poison metabolism, anti-infection, liver protection and local puncture.
Humans ; Insecticides ; Injections, Intramuscular ; Pyrethrins ; Nitriles/metabolism*

OBJECTIVETo investigate the effect of deltamethrin (DM) on production of reactive oxygen species (ROS) of rat pheochromocytoma (PC12) cells and its mechanism.

METHODSPC12 cells were treated with various dose of DM (0, 10 or 100 micromol/L) for 1, 6 or 12 h respectively. Furthermore, PC12 cells were treated with various dose of DM (0, 10 or 100 micromol/L) for 24 or 48 h, respectively. PC12 cells were pre-incubated with 10 mmol/L N-acetyl-L-cysteine (NAC) for 2 h, or with 500 micromol/L DL-Buthionine-[S, R]-Sulfoximine (BSO) for 16 h, or with 40 micromol/L tertiary butylhydroquinone (tBHQ) for 16 h, prior to exposure to DM and then with 10 micromol/L DM for 6 h. After treatment, ROS production in PC12 cells were measured by a molecular probe, 2', 7'-dichlorofluorescein diacetate (DCFH-DA).

RESULTSDM induced a dose-time dependent increase in ROS production (indicated by DCF fluorescence intensity). 10 micromol/L DM treatment for 6 h enhanced DCF fluorescence intensity that reached approximately 2.24 times of values of control group. Furthermore, a pretreatment with NAC, BSO or tBHQ significantly reduced the DM-enhanced DCF fluorescence intensity that reached approximately 22%, 62% or 38% of values of DM treatment, respectively (P < 0.05), indicating that all these pretreatments attenuate ROS production.

CONCLUSIONThe in vitro studies demonstrate that DM could enhance ROS production, and may be the influential factor for the decreased mercapto level and antioxidative function.

Animals ; Nitriles ; pharmacology ; PC12 Cells ; Pyrethrins ; pharmacology ; Rats ; Reactive Oxygen Species ; metabolism

OBJECTIVETo study the effects of pyrethroids on the activity of gamma-aminobutyric acid transferase (GABAT) in rat brain.

METHODThe coupled enzyme ultraviolet spectrophotography was applied to observe the effects of deltamethrin (DM) and permethrin (PM) on the activities of GABAT in rat cerebral cortex, hippocampus, corpus striatum and cerebellum in vitro and in vivo.

RESULTSIn vitro, DM and PM had no significant effects on the activities of GABAT in rat cerebral cortex, hippocampus, corpus striatum and cerebellum at the final concentration of 10(-9) - 10(-4) mol/L. When 37.5 mg/kg DM and 600 mg/kg PM were orally administrated to the rats at one time, the activities of GABAT in rat cerebral cortex, hippocampus and cerebellum in the DM group [(2.96 +/- 0.43), (2.13 +/-0.44), (5.12 +/- 1.36) nmol x mg pro(-1) x min(-1), respectively] were lower than those in the control group [(3.43 +/- 0.41), (2.68 +/- 0.47), (6.74 +/- 1.64) nmol x mg pro(-1) x min(-1)] (P < 0.05), and the activities of GABAT in rat cerebral cortex and hippocampus in the PM group [(4.57 +/- 0.30), (4.18 +/- 0.63) nmol.mg pro(-1) x min(-1), respectively] were higher than those in the control group (P < 0.05). When 12.5 mg/kg DM and 200 mg/kg PM were orally administrated to the rats once a day for consecutive five days, the two pesticides had no significant effects on the activities of GABAT in rat cerebral cortex, hippocampus, corpus striatum and cerebellum (P > 0.05).

CONCLUSIONSIn vitro, DM and PM had no significant effects on the activity of GABAT in rat brain; in vivo, DM and PM may have different effects on the activity of GABAT in rat brain, which deserve further study.

Animals ; Brain ; drug effects ; enzymology ; In Vitro Techniques ; Insecticides ; toxicity ; Male ; Pyrethrins ; toxicity ; Rats ; Spectrophotometry ; Transferases ; metabolism ; gamma-Aminobutyric Acid ; metabolism

OBJECTIVETo study the effects of deltamethrin (DM) on cell survival rate and intracellular Ca(2+) ([Ca(2+)]i) concentration in primary cultured astrocytes of rat.

METHODSThe cell survival rate was measured by Typan Blue assay; the intracellular [Ca(2+)]i concentration was determined by the fluorescent Ca(2+) indicator Fura-2/AM.

RESULTSThe survival rate of astrocytes was decreased to 91.9% after astrocytes were incubated with 1 x 10(-5) mol/L DM for 72 h (P < 0.05). The cell survival rates were 89.0%, 84.8%, 81.2% and 79.2% respectively when astrocytes were administered with 1 x 10(-4) mol/L DM for 4, 12, 24 and 72 h, which were remarkably lower than control groups (P < 0.01). Comparing with controls and before DM treatment, sharp increases in [Ca(2+)]i concentration [(451.4 +/- 42.3), (536.9 +/- 47.5) and (870.9 +/- 100.5) nmol/L respectively] were observed when astrocytes were incubated with 1 x 10(-7), 1 x 10(-6) and 1 x 10(-5) mol/L DM for 5 minutes (P < 0.01). After astrocytes were treated with 1 x 10(-8), 1 x 10(-7), 1 x 10(-6), 1 x 10(-5) mol/L DM for 15 minutes, the [Ca(2+)]i concentrations were decreased to (124.3 +/- 6.0), (131.3 +/- 19.1), (118.9 +/- 1.4), (136.6 +/- 3.8) nmol/L respectively, which were significantly different from those of controls and before treatment. And this situation was almost keeping stable to 30 min.

CONCLUSIONThe cell survival rate was decreased and the [Ca(2+)]i concentration was temporarily increased when astrocytes were treated with DM.

Animals ; Astrocytes ; cytology ; drug effects ; metabolism ; Calcium ; metabolism ; Cell Survival ; drug effects ; Cells, Cultured ; Insecticides ; toxicity ; Nitriles ; Pyrethrins ; toxicity ; Rats

OBJECTIVETo investigate the diversity of acetylcholinesterase (AChE) activity in variety classes and strains of Culex pipiens pallens and provide a basis for the insecticide-resistance detection of mosquito by biochemical method.

METHODSAChE insensitivity of single mosquito was determined, using acetythiocholine iodide (ATch) as the substrate, 5,5'-dithio-bis (2-nitrobenzoic acid) (DTNB) as the developer, and propoxur as the inhibitor.

RESULTThere were significant differences in AChE activity among the four types of IV instar larvae and 3-day-old adult female of sensitive strain mosquito (P<0.01). The AChE activity of the 3-day-old adult female was higher than that of IV instar larvae of the four types of sensitive strain mosquito (P<0.01). The AChE activity of anti-DDVP (Rd) and anti-propoxur (Rp) strains of Culex pipiens pallens was significantly higher than that of sensitive (S) strain (P<0.01), while the AChE activity of anti-cypermethrin (Rc) strain of Culex pipiens pallens was similar to that of S strain (P>0.05). The individual frequency of insensitive AChE of Rd and Rp strains of Culex pipiens pallens was significantly higher than that of sensitive (S) strain (P<0.01), while the individual frequency of insensitive AChE of Rc strain of Culex pipiens pallens was similar to that of S strain(P>0.05).

CONCLUSIONThe AChE activity determination can be used to examine the insecticide-resistance of mosquito.

Acetylcholinesterase ; metabolism ; Animals ; Culex ; classification ; enzymology ; Dichlorvos ; pharmacology ; Female ; Insecticide Resistance ; Propoxur ; pharmacology ; Pyrethrins ; pharmacology ; Species Specificity

OBJECTIVETo evaluate the influence on the synaptic protein expression in different brain regions of ICR mice after lambda-cyhalothrin (LCT) exposure during postnatal period.

METHODSTwo male and 4 female healthy ICR mice were put in one cage. It was set as pregnancy if vaginal plug was founded. Offspring were divided into 5 groups randomly, and exposed to LCT (0.01% DMSO solution) at the doses of 0.1, 1.0 and 10.0 mg/kg by intragastric rout every other day from postnatal days (PND) 5 to PND13, control animals were treated with normal saline or DMSO by the same route. The brains were removed from pups on PND 14, the synaptic protein expression levels in cortex, hippocampus and striatum were measured by western blot.

RESULTSGFAP levels of cortex and hippocampus in the LCT exposure group increased with doses, as compared with control group (P < 0.05), while Tuj protein expression did not change significantly in the various brain regions of ICR mice. GAP-43 protein expression levels in the LCT exposed mouse hippocampus and in female ICR mouse cortex increased with doses, as compared with control group (P < 0.05). Presynaptic protein (Synapsin I) expression levels did not change obviously in various brain regions. However, postsynaptic density protein 95 (PSD95) expression levels of the hippocampus and striatum in male offspring of 10.0 mg/kg LCT group, of cortex of female LCT groups, and of female offspring in all exposure groups, of striatum, in 1.0 or 10.0 mg/kg LCT exposure groups significantly decreased (P < 0.05).

CONCLUSIONSEarly postnatal exposure to LCT affects synaptic protein expression. These effects may ultimately affect the construction of synaptic connections.

Animals ; Animals, Newborn ; Brain ; drug effects ; metabolism ; Corpus Striatum ; drug effects ; metabolism ; Female ; Hippocampus ; drug effects ; metabolism ; Male ; Mice ; Mice, Inbred ICR ; Nitriles ; toxicity ; Pyrethrins ; toxicity ; Synapsins ; metabolism

OBJECTIVETo explore the effect of deltamethrin (DM) on production of free radical and transcription factor Nrf2 in rats' brain tissue.

METHODS8 male rats were randomly assigned to four groups and administered with 1% W/W tertiary butylhydroquinone (tBHQ) or olive oil for 3 days, prior to exposure to DM and then with 12.50 mg or 0mg DM/Kg BW for 5 days. The level of free radical in rats' hippocampus tissue was detected by electron spin resonance (ESR) spectroscopy. 18 male rats were randomly assigned to three groups and administered with i.p. (daily dose was respectively 0, 3.13, 12.50 mg/kg DM) for five days. After treatment, Nrf2 protein levels in the cytoplasmic and nuclear fractions of both cerebral cortex and hippocampus tissue were measured by western blot.

RESULTSThe level of free radical in hippocampus tissue of rats administered by DM and pretreatment with tBHQ prior to DM were increased to a 2.45-fold and 2.97-fold of values of control group, respectively (P < 0.05). Nrf2 protein levels in the cytoplasmic fractions of cerebral cortex of both low and high dose group were significantly increased, 1.68- fold and 1.34- fold of values of control group, respectively. Nrf2 protein levels in the nuclear fractions of cerebral cortex of both low and high dose group were increased in a dose- dependent model, 1.51-fold and 2.29-fold of values of control group, respectively (P < 0.01). Nrf2 protein levels in the cytoplasmic fractions of hippocampus tissue of both low and high dose group were increased in a dose- dependent model, 2.26-fold and 3.58-fold of values of control group, respectively. Nrf2 protein levels in the nuclear fractions of hippocampus tissue of both low and high dose group were increased, 2.42-fold and 2.45-fold of values of control group, respectively (P < 0.01).

CONCLUSIONThe studies in vivo demonstrate that DM treatment could induce free radical production and expression of Nrf2 protein in both cerebral cortex and hippocampus tissue and activate Nrf2.

Animals ; Brain ; drug effects ; metabolism ; Free Radicals ; metabolism ; Male ; NF-E2-Related Factor 2 ; metabolism ; Nitriles ; toxicity ; Pyrethrins ; toxicity ; Rats ; Rats, Sprague-Dawley

Animals ; Cells, Cultured ; Interleukin-1beta ; pharmacology ; Male ; Neurons ; drug effects ; metabolism ; Nitric Oxide ; metabolism ; Nitriles ; toxicity ; Pyrethrins ; toxicity ; Rats ; Rats, Sprague-Dawley ; Sodium-Potassium-Exchanging ATPase ; metabolism

OBJECTIVETo study the effect of deltamethrin on the apoptotic rate and the expression of caspase-3 in rat neural cells.

METHODSMale Wistar rats were randomly divided into 5 groups: control, 5 h, 24 h, 48 h and 5 d exposed groups. Apoptotic rate and the expression of caspase-3 were measured by FACS420 Flow Cytometer; Ac-DEVD-pNa was used as a substrate to detect the activity of caspase-3.

RESULTSApoptotic rates in 24 h, 48 h and 5 d exposed groups in hippocampus and cerebral cortex [hippocampus: (8.45 +/- 1.02)%, (9.44 +/- 1.14)%, (7.58 +/- 0.75)%; cerebral cortex: (7.90 +/- 0.49)%, (8.01 +/- 0.87)%, (7.97 +/- 0.41)% respectively] were higher than those in the control [hippocampus: (2.97 +/- 0.36)%; cerebral cortex: (3.50 +/- 0.48)%] (P < 0.01); the activity of caspase-3 in 5 h, 24 h and 48 h exposed groups (A(405) nm in hippocampus: 0.389 +/- 0.038, 0.472 +/- 0.041, 0.295 +/- 0.049; A(405) nm in cerebral cortex: 0.321 +/- 0.068, 0.429 +/- 0.077, 0.344 +/- 0.047) and 5 d group of hippocampus (0.246 +/- 0.065) were all higher than those of the control (hippocampus: 0.184 +/- 0.054; cerebral cortex: 0.198 +/- 0.049) (P < 0.05, P < 0.01); the expression of caspase-3 in 5 h, 24 h and 48 h exposed groups increased apparently while 5 d group did not.

CONCLUSIONExposure to high dose of deltamethrin would affect the apoptosis, the activity and expression of caspase-3 in rat neural cells. The increase in caspase-3 activity and expression occurred before the rising of neuronal apoptotic rate may be the upstream event of apoptosis.

Animals ; Apoptosis ; drug effects ; Caspase 3 ; Caspases ; metabolism ; Cerebral Cortex ; enzymology ; pathology ; Hippocampus ; enzymology ; pathology ; Insecticides ; pharmacology ; Male ; Nitriles ; pharmacology ; Pyrethrins ; pharmacology ; Random Allocation ; Rats ; Rats, Wistar