Neurotoxic effect of dermally-applied chlorpyrifos and cypermethrin in Wistar rats.

The aim of the study was to evaluate the neurotoxic effect of a dermally-applied mixture of chlorpyrifos and cypermethrin in rats based on cognitive function, activity of the blood cholinesterase and brain acetylcholinesterase, as well as histologic brain examination. Nurelle D 550 EC (500 g of chlorpyrifos and 50 g of cypermethrin) was used in the study. The application liquid was in the form of a water solution. The investigation covered eight groups of animals: six experimental groups and two control groups, of 15 rats each. Experimental groups received 5.6 mg/cm2 chlorpyrifos and 0.5 mg/cm2 cypermethrin, or 27.8 mg/cm2 chlorpyrifos and 2.7 mg/cm2 cypermethrin dermally, for one day, one week and four weeks, except for Saturdays and Sundays. The preparations examined were applied to the tail skin of rats. The animals were anaesthetized at the end of exposure period. Plasma cholinesterase and brain acetylcholinesterase activities were determined. The brain for histological examination was perfused with a solution of methanol, formalin and glacial acetic acid, and the sections stained by the Nissel method. The behaviour of the animals was evaluated in the open field test four times: before exposure, and after one, two and four weeks of the experiment. The results of the study showed that chlorpyrifos and cypermethrin applied in a mixture caused an inhibition of cholinesterase and acetylcholinesterase activity and elicited the pycnosis of brain neurocytes.

Oral toxicity of deltamethrin and fenvalerate in Swiss mice.

The study was conducted on female and male Swiss mice with body mass of 20-30 g. The experimental animals were administered deltamethrin in concentrations of 5 mg/kg b.m. (1/10 LD50) and 25 mg/kg b.m. (1/2 LD50), or fenvalerate in the doses of 10 mg/kg b.m. (1/10 LD50) and 50 mg/kg b.m. (1/2 LD50). Pyrethroids were administered intragastrically once a day for 28 days. Parallel studies were conducted in two control groups. The following organs were taken for histologic examinations: liver, kidney, lung, heart and spleen. Blood was taken from the heart for hematologic tests. The total number of erythrocytes and leukocytes, the percentage of neutrophils and lymphocytes, as well as the level of hemoglobin and hematocrit were determined. Deltamethrin and fenvalerate caused degenerative changes in the liver and kidneys in Swiss mice. Changes were more intense in male mice which were administered deltamethrin, and in female mice which received fenvalerate. Irrespective of the dose, the pyrethroids examined stimulated erythropoiesis and synthesis of hemoglobin in male Swiss mice, while in female mice the administration of deltamethrin in the dose of 1/10 LD50 resulted in the suppression of erythropoiesis and hemoglobin synthesis. Both in male and female mice, deltamethrin and fenvalerate--irrespective of the dose--caused a general increase in the number of leukocytes.

Subacute toxicity of orally applied alpha-cypermethrin in Swiss mice.

The effect of a synthetic pyrethroid - alpha-cypermethrin administered per os for 28 days to Swiss mice was examined on phagocytic and bactericidal activity of neutrophils, and leukocytic image, IL-12 p70 level in blood plasma, as well as histologic and ultrastructural picture of the liver, heart, kidneys, lung and spleen. A synthetic pyrethroid alpha-cypermethrin, [(R,S)-alpha-cyano-3-phenoxybenzyl (R,S)-cis,trans-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylate], produced by the Chemical Plant in Jaworzno was used in the study. The preparation for the application per os was used in doses 1/2 LD(50) (25 mg/kg body mass) and 1/5 LD(50) (10 mg/kg body mass). The results were presented as mean (x) +/- standard error (SEM) and subjected to statistical analysis by the parametric t-Student test. Subacute poisoning of mice with alpha-cypermethrin in doses 1/2 LD(50) and 1/5 LD(50) resulted in decreased bactericidal activity of neutrophils. The dose 10 mg/kg body mass had a stronger stimulatory effect on phagocytic activity than 25 mg/kg body mass. Significantly higher numbers of monocytes and lymphocytes were observed in the blood of male mice poisoned with 1/5 LD(50) alpha-cypermethrin. The administration of alpha-cypermethrin resulted for both doses in the decrease in IL-12 p70 serum secretion. The lowest IL-12 p70 level (pg/ml) was noted among female mice administered 1/2 LD(50) of the preparation. The results of the study may indicate that the pyrethroid in the study had a suppressive effect on Il-12 p70 production. In mice administered 1/5 LD(50) or 1/2 LD(50) of the preparation examined, histopathologic and ultrastructural changes were observed in the liver and kidneys.

[Mode of delivery in twin gestations from material at the Department of Obstetrics in the District hospital of Lublin]. / Przebieg porodów blizniaczych w materiale Oddzialu Polozniczego Samodzielnego Publicznego Szpitala Wojewódzkiego im. Jana Bozego w Lublinie.

The aim of this study was to review 39 twin deliveries in the Department of Obstetrics in District Hospital in Lublin in 1998. The incidence of twin pregnancies was 2.01%. Eighteen patients (46.15%) were term at delivery whereas 21 (53.8%) were premature (mean gestational age at delivery 35 weeks). Vertex presentation of both twins was the most common with an incidence of 48.7% followed by vertex-nonvertex (25.6%) and non-vertex presentation of first twin (15.4%). Twenty patients (51.28%) delivered vaginally and 19 women (48.7%) underwent cesarean section including 2 cesarean birth of second twin after vaginal delivery of first twin. In our results, we conclude that the techniques of twin delivery, whether vaginal or by cesarean section, would depend on the judgement and expertise of the labour in twin gestations.