Immune response in mice infected by Encephalitozoon cuniculi and suppressed by dexamethasone.

Several indicators of immune response were observed in immunocompetent mice of the ICR line and those suppressed by dexamethasone upon their experimental infection with the microsporidia of Encephalitozoon cuniculi. The mice were infected by one-shot intraperitoneal administration of 5 x 10(7) pathogenic spores. On Days 7, 14, 28 and 42 after infection, peripheral blood leukocyte phagocytic activity was determined and compared, including phagocytic index and the blastogenic response in spleen cells to mitogenic activation by concanavalin A and phytohaemagglutinin. The results point to the fact that E. cuniculi itself can cause a significant decrease in phagocytic activity of phagocytic leukocytes in the early stages of infection as well as a remarkable decrease in the proliferative response of spleen cells to T-cellular mitogens.

[The effect of supermethrin, an insecticide, on health status indicators in sheep during subchronic poisoning]. / Vplyv insekticídu supermetrín na niektoré ukazovatele zdravotného stavu oviec v podmienkach subchronickej intoxikácie.

The effect of supermethrin on the overall health with respect to weight gains, diet intake, triad values (body temperature, pulse rate and breathing rate) and potential intoxication signs was investigated in sheep of the Slovak Mertino breed (age of 8 months, males and females) during 6-week feeding of the insecticide supermethrin (Research Institute of Chemical Technology, Bratislava). This insecticide supermethrin contains a cyanide group in its molecule and can be included in the group of type II pyrethroids. It is an analog of cypermethrin and it has a different proportion of cis- and trans-isomers. Supermethrin mixed with molasses feed M was administered daily at a dose of 50 mg/kg (about 1/70 of LD50) to five sheep of experimental group I, at a dose of 200 mg/kg (about 1/15 of LD50) to five sheep of experimental group II, and the dose increased from 200 mg to 300 mg/kg l.w. (about 1/20 of LD50) since the fourth week of trial. The main signs of its toxic action involved depressive effects on weight gains (Fig. 4) Over the whole period of trial, the live weight rose by 5.44 +/- 1.94 kg in control group, by 2.66 +/- 1.48 kg in experimental group I, which equates a significant decrease by 51.10% and only 0.34 +/- 0.95 kg in experimental group II, which equates a decrease in weight gains by up to 93.75% against the control. We do not believe that the growth depression can be related to diet intake. There were no larger differences in feed intake between the experimental groups and the control. The growth depression was caused by incessant diarrhea. The patho-morphological examination did not reveal hyperemia and/or intestinal inflammation, the histological examination did not show any lesions of epithelium in the intestinal mucosa. An increase in supermethrin dose from 200 to 300 mg/kg l.w. resulted in signs coming from the CNS. Hypersensibility manifested by moderate unrest, head and neck shaking after auditory, and especially after touch stimuli was observed. This tremor was increasing to became spontaneous 3-4 days before trial termination. The above findings clearly suggest that supermethrin administration at lower doses has harmful effects primarily on the digestive tract, but at higher doses these effects are more intensive accompanied by the effects on the CNS. No negative effects on pulse rate (Fig. 1), breathing rate (Fig. 2) and internal body temperature (Fig. 3) were recorded.

[Toxicologic evaluation of supermethrin, a pyrethroid insecticide, in rabbits and pheasants]. / Toxikologické hodnotenie pyretroidného insekticídu supermetrínu u králikov a bazantov.

Basic information about a toxicologic hazard of the pyrethroid supermethrin (Research Institute of Chemical Technology, Bratislava) is presented in this paper for the conditions of acute intoxication in rabbits and pheasants and in the conditions of subacute intoxication in pheasants. The insecticide supermethrin under observation contains a cyanide groups in its molecule and can be included in the group of type II pyrethroids comprising among other substances also cypermethrin. Supermethrin is an analog of the latter and it has a different proportion of cis- and trans-isomers. At acute intoxication, supermethrin was applied to adult rabbits at doses of 2,000; 3,000; 4,000; 5,000 and 6,000 mg/kg and to adult pheasants at doses of 2,000; 4,000; 5,000 and 6,000 mg/kg live weight. Supermethrin dissolved in sunflower oil at a 1:2 ratio was administered in the above differentiated doses at single application by a peroral tube. Not even the highest supermethrin dose (6,000 mg/kg live weight) caused any clinical signs of intoxication in the birds. This fact suggests that its LD50 for rabbits and pheasants will apparently exceed the value of 6,000 mg/kg l.w. At subacute intoxication, supermethrin was applied as dissolved in sunflower oil (at a 1:2 ratio) by per os tube at a dose of 500 mg/kg l.w. once a day within five days. The subacute doses of supermethrin did not induce, besides mild diarrhea at the end of the trial, any other clinical signs of intoxication in the pheasants. The negative effect of supermethrin (even though negligible) on the digestive tract of pheasants is in agreement with the results determined in sheep in the conditions of subchronic intoxication (Neuschl et al., 1995), Supermethrin administration in sheep resulted in permanent and intensive diarrheas. These findings clearly indicate that supermethrin administered at lower doses primarily affects the function of digestive tract. Tab. 1 shows the effect of supermethrin on the live weight of pheasants in the conditions of subacute intoxication. The negligible decrease in live weight recorded at the end of the trial was not due to supermethrin effects. It was also recorded in the control group. There were no significant differences between the control and experimental group. It was probably induced by the stress resulting from daily applications of the tested substance. In case the guidelines for its areal application (140 g/ha) are observed, it will not be toxic for rabbits and pheasants nor probably for hares and/or other gallinaceous birds. Supermethrin seems to be a little toxic substance according to WHO (1975) classification.

[The effect of bentazone TP, an herbicide, on hematologic indicators in sheep during acute and subchronic poisoning]. / Vplyv herbicídu bentazón TP na hematologické ukazovatele u oviec v podmienkach akútnej a subchronickej intoxikácie.

Hematological changes at poisoning with the bentazone herbicide manufactured by the Research Institute of Chemical Technology in Bratislava were investigated in sheep of the Slovak Merino breed. Acute intoxication in seven head of sheep was induced by a single application of bentazone with cannula at a sublethal dose of 1,450 mg/kg live weight. Bentazone was diluted with sunflower oil at a ratio 1:5. Subchronic intoxication was induced by an administration of bentazone in feed to the sheep for 84 days: a dose of 175 mg/kg live weight (1/10 of LD50) for the first experimental group (six head), and a dose of 97.5 mg/kg live weight (1/12 of LD50) for the second experimental group (six head). The control group did not receive any dietary bentazone. Acute intoxication with herbicide did not cause any statistically significant changes in hemoglobin, erythrocyte and leucocyte counts in the sheep within 120 hours after application. In comparison with the physiological standard, a slight increase in the percentage of neutrophils and a decrease in the lymphocyte percentage were observed. The values of eosinophils, basophils and monocytes remained unchanged. Observation of subchronic intoxication did not reveal any significant negative effect of the two doses of the herbicide within 84 days on the hematological parameters. Our experiments demonstrate that bentazone does not negatively influence blood formation.

[Acute oral toxicity of bentazon, an herbicide developed in Czechoslovakia, in pheasants and rabbits and the clinical symptoms of poisoning]. / Akútna orálna toxicita ceskoslovenského vývojového herbicídu bentazón u bazantov a králikov a klinická symptomatológia otravy.

Adult rabbits of the New Zealand White breed and pheasants were used to determine the rate of acute oral toxicity (LD50), clinical symptomatology of poisoning of organisms loaded with lethal doses, and the recovery of intoxicated individuals from the toxic effects of bentazon, Czechoslovak developmental herbicide (Research Institute of Chemical Technology, Bratislava), administered at sublethal doses within the framework of obligatory toxicological testing of this herbicide. The determined acute oral toxicity (LD50) was 1139 mg/kg in rabbits and 2918 mg/kg of live weight in pheasants. The table shows LD50 of the tested herbicide for various animal species. The LD50 values of bentazon produced abroad (Germany) are also shown for comparison in this table. If the LD50 values of both herbicides are compared, Czechoslovak developmental bentazon appears safer. The administration of lethal doses (1110 and 1170 mg/kg in rabbits, 2750 and 3100 mg/kg of live weight in pheasants) resulted in clinical symptoms of poisoning detected predominantly in the respiratory system. Shallow accelerated breathing and dyspnoea, CNS suppression, pronounced increase in body temperature, rapid onset and high intensity of rigor mortis were observed. Animals which died as a result of asphyxia induced by the sublethal doses (1000 mg/kg in rabbits and 2200 mg/kg in pheasants) were observed after 2-4 days. Difficult accelerated breathing and increased body temperature disappeared after 1-2 days while the remaining symptoms after 2-3 days. The loss of appetite persisted for 2-4 days.(ABSTRACT TRUNCATED AT 250 WORDS)

[The effect of bentazone, an herbicide produced in Czechoslovakia, on the invasiveness of intestinal nematodes in sheep]. / Vplyv herbicídu bentazón ceskoslovenskej proveniencie na invadovanost oviec gastroenteronematódami.

Possible anthelmintic effects of the Czechoslovak herbicide bentazone (Research Institute of Chemical Technology, Bratislava) on gastrointestinal tract strongylates of common occurrence were investigated in sheep of the Slovak Merino breed (housed on deep bedding and put out to grass daily) during the autumn and spring seasons. Our orientation to the investigation of anthelmintic effects of the mentioned herbicide resulted from the fact that its possible intervention in the energy metabolism of helminths could not be excluded, as it was indirectly indicated by our toxicological studies under the conditions of acute and subacute intoxication. Bentazone was administered at a dose of 250 mg/kg live weight in autumn and 500 mg/kg live weight in the spring season. It was administered per os as a single dose in sunflower oil. A control coprological examination on day 10 following the administration of the herbicide in question indicates the lower invasiveness of sheep in comparison with findings prior to its application (Tab. I) in both experiments (autumn, spring). No marked dose-dependent differences of bentazone efficiency were recorded.

[The effect of bentazone manufactured in Czechoslovakia on the synthesis of bacterial proteins in the rumen of sheep]. / Vplyv bentazónu cs. výroby na syntézu bakteriálnych proteínov v bachore oviec.

The effect of the perorally ingested pesticide bentazone (195 mg.kg-1) of Czechoslovak origin on the amino acid composition of proteins of bacteria adhering to the ventral and dorsal ruminal wall investigated in six sheep. Proteosynthesis of adherent bacteria was studied by a modified and quantified elution method (elution of bacteria by an isotonic buffered solution at 4 degrees C). By the latter, a concentrate of undamaged bacteria a adhering to the sheep ruminal epithelium could be obtained. The yield of the method was estimated by scanning electrone microscopy and it was 93.3% (Legáth et al., 1990). The high correlation coefficient (r = 0.94, p < 0.01) suggested that in comparison with the control group of sheep, bentazone in the diet did not have a marked effect on the amount of amino acids in hydrolyzates of bacteria adhering to the dorsal and ventral ruminal epithelium. From the analysis of the single amino acids, it however follows that bentazone in the feeding ration caused significant changes in the concentrations of some amino acids in the proteins of bacteria adhering to the epithelium in the ventral and dorsal part of the rumen (p < 0.05) (Tab. I, II). In both topographico-anatomical parts of the rumen phenylalanine levels significantly increased whereas those of alanine and glycine decreased (Fig. 1). Pesticides can be one of the factors that negatively affect the biosynthetic processes in the rumen of ruminants.(ABSTRACT TRUNCATED AT 250 WORDS)

Clinical signs and mechanism of supermethrin intoxication in sheep.

Three Slovak Merino sheep, weighing 38, 40 and 41 kg, were given single doses of 1500, 2700 or 3000 mg supermethrin/kg body weight. Clinical signs of intoxication were observed, and after death or sacrifice free cyanide levels were determined in the rumen contents and liver. The sheep that received 3000 mg supermethrin/kg had 7.2 and 0.58 mg cyanide/kg in the rumen contents and liver, respectively; the sheep that received 2700 mg supermethrin/kg had 5.8 and 0.52 mg cyanide/kg in the rumen contents and liver, respectively; whereas the sheep given 1500 mg supermethrin/kg had no free cyanide detected in the rumen contents or liver.

[Levels of mercury in the organs and tissues of sheep after administration of very low doses]. / Koncentrácie ortute v orgánoch a tkanivách oviec po zátazi organizmu extrémne nízkymi jej dávkami.

Experiments were carried out with six sheep of the Slovak Merino breed, weighing 22-28 kg. For 28 days the animals were given 4 mg inorganic Hg2+ in the feed per animal/day. In contrast with the controls, the following residual mercury concentrations were determined in the single organs and tissues: liver 1.580 +/- 0.326 mg.kg-1 Hg2+ and 0.091 +/- 0.014 mg.kg-1 Hg2+, respectively muscle 0.064 +/- 0.009 mg.kg-1 Hg2+, and 0.026 +/- 0.006 mg.kg-1 Hg2+, resp. spleen 0.142 +/- 0.025 mg.kg-1 Hg2+, and 0.022 +/- 0.010 mg.kg-1 Hg2+, resp. kidney 9.054 +/- 3.794 mg.kg-1 Hg2+, and 0.128 +/- 0.080 mg.kg-1 Hg2+, resp. (Fig. 1), abomasal contents 0.309 +/- 0.069 mg.kg-1 Hg2+, and 0.021 +/- 0.007 mg.kg-1 Hg2+, resp. large intestinal contents 0.267 +/- 0.058 mg.kg-1 Hg2+, and 0.043 +/- 0.004 mg.kg-1 Hg2+, resp. The results suggest that the long-term ingestion of mercury with feed leads to a pronounced Hg accumulation in the kidneys and liver. Much lower levels were observed in the muscle tissue and spleen. The affinity of mercury to the kidney and liver is probably related to the preferential bonds of organic mercury compounds to the SH- groups of the plasma proteins in these organs. It is the bond to the sulphydryl groups of proteins that results in the inhibition of proteosynthesis and thus enzyme and antibody inhibition. Under the conditions of continuing chemical contamination of the environment, a permanent supply of low concentrations of heavy metals the animal organism is observed.(ABSTRACT TRUNCATED AT 250 WORDS)

[The effect of Bentazone, a Czechoslovak developmental herbicide, on health status indicators in sheep during subchronic poisoning]. / Vplyv ceskoslovenského vývojového herbicídu bentazón na niektoré ukazovatele zdravotného stavu oviec v podmienkach subchronickej intoxikácie.

A three-month feeding trial was conducted with sheep of the Slovak Merino breed (13-14 months of age, males and females) as a part of the obligatory toxicological tests of the Czechoslovak developmental herbicide bentazone (Research Institute for Chemical Technology, Bratislava). Partial results are shown describing the action of this herbicide on the overall health of sheep with respect to weight gains, trias values and intrauterine foetus development. The sheep of the first experimental group were fed bentazone as an additive to molasses feed M at a daily rate of 195 mg/kg lwt. (1/10 from LD50), and the sheep of the second group were fed a rate of 97.5 mg/kg lwt. (1/20 from LD50). No symptoms of the toxic effects of bentazone were observed in the course of the experiment. There were no differences between the experimental and test animals in the dynamics of pulse value changes (Fig. 1), breathing value changes (Fig. 2) and body temperature value changes (Fig. 3) from the beginning till the end of the trial. A slight increase in the pulse and breathing values above the upper reference value observed in the experimental groups in the last two to three weeks of the trial cannot be associated with the bentazone action. This increase reflects the physiological condition of the animals in the given conditions because the identical changes were also found in the control group. We assume that the changes were evoked by the elevated temperature of the external environment due to the fact that the sheep were not sheared.(ABSTRACT TRUNCATED AT 250 WORDS)

[The effect of age on pharmacokinetic parameters of oxytetracycline and rolitetracycline in rabbits]. / Vplyv veku králikov na niektoré farmakokinetické parametre oxytetracyklínu a rolitetracyklínu.

The effect of rabbit age in the Californian White breed was investigated on oxytetracycline and rolitetracycline concentrations in the blood serum and soft tissues, and on the biological half-life of the given antibiotics. The animals were at the age shortly before sexual maturity or they had reached sexual maturity. Oxytetracycline was administered in form of the preparation Oxymykoin inj. a. u. v. Spofa and roliteracycline nitrate in form of the preparation Rolitetracycline inj. Spofa. These tetracyclines were administered intramuscularly at a single dose of 20 mg per kg liveweight. In comparison with adult animals, in young rabbits the starting concentrations of the two tetracyclines in the blood (first hour) were statistically insignificantly higher; they were resorbed in the systemic circulation in a shorter time and were excreted faster from the blood (mainly oxytetracycline). The significantly lower serum concentrations were recorded in the 6th, 12th and 24th hour after oxytetracycline administration, and in the 12th and 24th hour after rolitetracycline administration. At the same time a decrease was observed in the concentrations of the two oxytetracyclines in the organs and muscles of young animals.

[Comparison of pharmacokinetic parameters of tetracyclines which are most frequently used in veterinary medicine]. / Vergleich einiger pharmakokinetischer Parameter der in der Veterinärmedizin am häufigsten angewandten Tetrazykline.

40 adult White Californian rabbits were monitored for serum levels, soft tissue concentrations, and biological half-life of technical chlorotetracycline (Aureovit 12 C40 -- SPOFA), chlorotetracycline chloride (Farmitalia substance), tetracycline chloride (tetramyocine tablets for veterinary use -- SPOFA), and oxytetracycline chloride (oxymycoine in powder form for solution for veterinary use -- SPOFA), following application of 20 micrograms.kg-1. All tetracyclines tested were orally administered by gavage, following dissolution or suspension (Aureovit 12 C40). Statistically significant differences were found to exist among serum levels of various tetracyclines, with the 1st to 11th hours from administration, whereafter differences turned minimal between the 11th and 24th hours. Differences were found to exist also among concentrations in various organs.