Clonorchiasis for which no specific therapy is available has been recognized as one of the serious public health problems in terms of waste of human productivity in Korea today and an urgent consideration must be given to its prevention and control. For past several years, the author has been finding that the infection rate of liver fluke in fish from the Kum-Ho river which has long been recognized as the world's notorious prevalent area of the disease, has been decreasing gradually. Here the author formulated the hypothesis that the decreasing of infection rate might be influenced by the common use of pesticide in plants along the river. Basing this hypothesis, the effective use of pesticide may contribute to the control of the disease by cutting the life cycle of liver fluke. To test above hypothesis, molluscicidal effect on Parafossarulus manchouricus and cercariacidal effect of various pesticides in liver fluke have been determined and the following results were obtained. In molluscicidal effect, the most potent agent in low concentration was Bayer 73 which is 3 to 70 times stronger than other pesticides. When compared with NaPCP which has been widely used for the eradication of Onchomelania, Bayer 73 shows 5 to 10 times stronger effect. The order of pesticide in molluscicidal effect was: Bayer 73, Nicotin, NaPCP, Sevin, Parathion, Copper sulfate and Lindane. In cercariacidal effect, the most potent agent was Parathion which had 2 to 5 times stronger effect than Bayer 73 or NaPCP. The order of pesticide in the cercariacidal effect was: Parathion, Bayer73, NaPCP, Lindane, Nicotin,Sevin, and Copper sulfate. By applying the common used concentration of pesticides considering the toxicity to plants, Bayer 73 is most potent in molluscicidal effect and then Nicotin, NaPCP, Copper sulfate, Sevin, Parathion and Lindane in order. In cercariacidal effect, Parathion is the most potent and NaPCP, Bayer 73, Lindane, and Copper sulfate are followed. Considering with the toxicity to human body the most safe and effective pesticides were Bayer 73, Seven, NaPCP, and Copper sulfate but among those agents, Bayer 73 and NaPCP show relatively stronger effect in both Parafossarulus manchouricus and cercaria of liver fluke.
parasitology ; helminth ; trematode ; Clonorhcis sinensis ; chemotherapy ; Parafossarulus manchouricus ; Onchomelania ; cercaria ; toxicology ; Bayer 73 ; Nicotin ; NaPCP ; Sevin ; Parathion ; Copper sulfate ; Lindane

Air Pollutants, Occupational ; analysis ; Carbaryl ; analysis ; Chromatography, High Pressure Liquid ; methods ; Workplace

OBJECTIVETo analyse the male reproductive toxicity of carbaryl.

METHODSThirty-one male carbaryl exposure workers and 46 male administrators in the office in a pesticide factory were selected as the exposure group and internal control group respectively, and 22 male administrators in a center for disease control and prevention were served as the external control group. In order to evaluate the exposure levels, the concentrations of carbaryl, methyl isocyanate, ammonia and phenol in the ambient air of the work place in these three groups were monitored simultaneously for three consecutive days. Moreover, three workers in the exposure group and the external control group were selected to evaluate the amount of carbaryl of individual and dermal contamination for three consecutive days. After the semen were collected according to the standard method, the workers'semen qualities were analysed with WHO method, the sperm morphology and the sperm motility were evaluated using micro-cell slide spectrum technology and computer assisted sperm analysis (CASA) respectively.

RESULTSIn the exposure group, the concentrations of carbaryl and phenol (52.41 mg/m(3) and 0.08 mg/m(3) respectively) were significantly higher than those in the internal and external control group (P < 0.01 or P < 0.05). Furthermore, in the carbaryl exposure area the geometric mean concentration of carbaryl with the individual sampling was 7.38 mg/m(3), and the geometric mean of dermal contamination detected in the carbaryl exposure area was 862.47 mg/m(2). Carbaryl was not found in the external control area (P < 0.01). The seminal volume [(2.39 +/- 1.44) ml] and the sperm motility [(1.77 +/- 0.61) grade] were significantly lower than those in the external control group (P < 0.05), and sperm motion parameters such as linearity (LIN, 39.89% +/- 6.00%), straightness (STR, 71.51% +/- 11.22%), straight line velocity [VSL, (26.29 +/- 7.84) microm/s] and beat cross frequency [BCF, (3.99 +/- 1.55) Hz] were lower than those in the internal and external control group (P < 0.05), while the abnormal rates of viscidity, sperm motility and total aberration rate were higher than those in the external control group (P < 0.05).

CONCLUSIONOccupational exposure to carbaryl production can affect the workers'sperm and semen quality to certain extent.

Adult ; Carbaryl ; adverse effects ; Humans ; Insecticides ; adverse effects ; Male ; Occupational Exposure ; Semen ; drug effects ; Sperm Motility ; drug effects ; Spermatozoa ; abnormalities ; drug effects

OBJECTIVETo investigate the effects of carbaryl on serum steroid hormone and function of antioxidant system in female Sprague Dawley rats.

METHODSCarbaryl was administrated to the adult female rats at doses of 0, 1.028, 5.140 and 25.704 mg x kg(-1) x d(-1) for 30 d. Vaginal smears of rats were taken to determine estrous cycle. Serum 17beta-estradiol (E(2)) and progesterone (P(4)) concentrations were measured by radioimmunoassay. The activities of superoxide dismutase (SOD) and glutathione-s-transferase (GST), and the levels of malondialdehyde (MDA) and glutathione (GSH) were measured by spectrophotometry.

RESULTSThe number of estrous cycle in exposed groups were obviously lower than in control group (P < 0.05, P < 0.01). Body weight gain in high dose group (25.704 mg x kg(-1) x d(-1)) was significantly lower than that in control. Meanwhile, the organ coefficient of ovary and uterus declined in a dose-dependent manner. Serum E(2) level [(19.93 +/- 2.21) nmol/L] in 25.704 mg group was lower than in control group [(28.76 +/- 6.12) nmol/L, P < 0.05], and P(4) level (1.21 +/- 0.40) nmol/L in 1.028 mg group was higher than that in control group [(0.63 +/- 0.39) nmol/L, P < 0.05]. The activity of SOD first reduced then rose in ovary, and first rose then reduced in serum. The contents of MDA increased in ovary, while decreased in the serum. GSH contents and GST activity increased in ovary, while in serum GSH contents decreased and GST activity first increased then decreased.

CONCLUSIONCarbaryl could disrupt estrous cycle and affect serum steroid hormone, and the function of antioxidant system in female SD rats.

Animals ; Antioxidants ; metabolism ; Carbaryl ; toxicity ; Estradiol ; blood ; Female ; Glutathione ; blood ; Glutathione Transferase ; blood ; Malondialdehyde ; blood ; Progesterone ; blood ; Rats ; Rats, Sprague-Dawley ; Superoxide Dismutase ; blood

A modified electrometric method was described and validated for measurement of plasma and erythrocyte cholinesterase activities in 6~18 months old goats. The enzymatic reaction mixture contained 3 ml distilled water, 3 ml barbital-phosphate buffer (pH 8.1), 0.2 ml plasma or erythrocytes and 0.1 ml acetylthiocholine iodide (7.5%) as a substrate. The mixture was incubated at 37 degrees C for 40 minutes. The pH of the reaction mixture was determined by a pH meter before and after the incubation. The initial pH was measured before the substrate addition. The enzyme activity was expressed as deltapH/40 min. The coefficients of variation of the described method in measuring plasma and erythrocyte cholinesterase activities were 4 and 2%, respectively. Preliminary reference values (n = 14) of the mean cholinesterase activity (deltapH/40 min) and 95% confidence interval in the plasma were 0.194 and 0.184~ 0.204, respectively, and those of the erythrocytes were 0.416 and 0.396~0.436, respectively. The pseudocholinesterase activity of the plasma cholinesterase was 63.5% as determined by quinidine sulfate inhibition. The organophosphorus insecticides dichlorvos and diazinon at 0.5~4 micrometer and the carbamate insecticide carbaryl at 5~20 micrometer in the reaction mixture significantly inhibited plasma (13.7~85.5%) and erythrocyte (16.4~71.9%) cholinesterases in vitro in a concentration-dependent manner. The results suggest that the described electrometric method is simple, precise and efficient in measuring blood cholinesterase activity in goats.
Acid-Base Equilibrium/physiology ; Animals ; Carbaryl/pharmacology ; Cholinesterase Inhibitors/pharmacology ; Cholinesterases/*blood/drug effects ; Diazinon/pharmacology ; Dichlorvos/pharmacology ; Enzyme Activation/drug effects/physiology ; Erythrocytes/metabolism ; Goats/*blood ; Plasma/metabolism