BACKGROUND: Titanium dioxide nanoparticles (TiO2NPs) are used in many commercial products, including paints, sunscreens and edible products, and can be used directly and indirectly in aquaculture. Due to the widespread application of these nanoparticles, the investigation of their possible effects on aquatic organisms is necessary. OBJECTIVES: The purpose of this study was to investigate the histopathological effects of waterborne TiO2NPs on the gills, liver and intestine of Caspian trout. METHODS: In this study, 126 fish (27.46±4.3 g) were tested in six concentrations of TiO2NPs (0, 0.01, 0.1, 1, 10 and 100 mg/L) for 4 days. At the end of the experiment, tissues were evaluated to determine the effects of tissue damage caused by TiO2NPs. RESULTS: The 96-h exposure to TiO2NPs did not cause fish mortality. Accordingly, investigated TiO2NPs are classified as "relatively non-toxic". The most important tissue changes caused by short-term exposure to TiO2NPs were hyperplasia and hypertrophy, lamellar fusion, necrosis in gills; foci of melanomacrophage deposits, aggregation of blood cell, hepatocytes with pycnotic nuclei, vacuolation, necrosis in liver; thickening of lamina propria, erosion of villi and necrosis in intestine. CONCLUSIONS: Although TiO2NPs are relatively non-toxic,  due to the tissue damage observed, these nanoparticles can be harmful to Caspian trout.

BACKGROUND: Ichthyophthiriasis induced by a freshwater teleost pathogen “Ichthyophthirius multifiliis” is one of the most important parasitic diseases with substantial economic losses to the aquaculture industry. Although malachite green, copper sulphate, formalin, and chloramine-T have been used to treat ichthyophthiriasis, there are  no chemicals that can be used safely and effectively to control this parasitic disease. As a result, application of natural, safe and strong components to prevent ichthyophthiriasis is of great importance. Objective: The aim of the present research is to determine the short-term effectiveness of tannic acid (TA) on the parasite theronts of I. multifiliis. Methods: In this study, TA as a main phenolic acid at different concentrations (0.0-7.0 mg/L) was applied to determine its acute toxicity against I. multifiliis theronts in various exposure times (1-3 h). The results were also statistically compared to the findings obtained from the control treatment and the positive control sample (15mg/L  formalin). Results: There was a significant and direct correlation between TA concentration and exposure time in order to enhance the mortality rate of I. multifiliis theronts. An increase in levels of TA and exposure time in the studied ranges can significantly intensify the mortality number (P<0.05). The used natural phenolic constituent similar to 15 mg/L formalin led to a significant reduction in number of these theronts (> 80%) at 60 min. Conclusions: Use of a standard phenolic agent such as TA at higher concentration and longer exposure time can potentially decrease the number of I. multifiliis theronts and control ichthyophthiriasis.

Recombinant bovine interferon alpha (rBoIFN-α) has been demonstrated to have antiviral activity. However, no conduct of acute or chronic toxicity tests has been reported.

Recombinant bovine interferon alpha (rBoIFN-α) has been demonstrated to have antiviral activity. However, no conduct of acute or chronic toxicity tests has been reported. Specific pathogen-free Sprague Dawley rats were administered doses at different concentrations through intraperitoneal or intravenous injection. After the administration (single for an acute toxicity test over 14 days or daily for a sub-chronic toxicity test over 30 days), the rats’ behaviour and other indicators and the degree of toxic reaction were continuously monitored. Blood was collected for haematological and serum biochemical examinations. At the end of the experiments, the rats were sacrificed for necropsy and histopathological tissue analysis. The external performance, behaviour characteristics, and changes in body temperature and body weight of the rats in each subgroup were comparable to the normal control subgroup. Except for a few cases, there were no lesions in the viscera’s pathological structures, and the blood parameters and biochemical indicators were not noticeably different from those of the control subgroup. This study suggests that rBoIFN-α seems to be safe for rats, and its use may foster the development of the cattle industry in China by protecting livestock health.

The pathogenicity and acute toxicity of Lactobacillus (L.) pentosus PL11 from eel (Anguilla japonica) were investigated using male and female Sprague-Dawley rats. The pathogenicity of L. pentosus PL11 was examined after treating the rats with 10∨11 CFU/mL, 10∨9 CFU/mL or 10∨7 CFU/mL doses of L. pentosus PL11 culture or 0.85% NaCl (Control) intragastrically. For acute toxicity studies, rats were treated with dried culture broth of L. pentosus PL11 at doses of 5,000 mg/mL, 2,500 mg/mL, 1,250 mg/mL or 625 mg/mL or Lactobacilli MRS broth (Control), and clinical signs or mortalities were monitored for two weeks. The results of the present investigation revealed no mortalities or obvious clinical signs in rats administered with the live bacterial cultures or dried culture broth at any investigated dose level. Also, no significant differences were observed in net body weight gain, gross pathological findings, feed and water consumption and body temperature among the different treatment groups and between the treated and control rats. It can be concluded from the above findings that L. pentosus PL11 is a safe probiotic strain with potential as feed additive to increase the feed efficiency or health of fish.

The present study was carried out to investigate the potential acute toxicity of CKD-602 by a single intravenous dose in Beagle dogs. The test chemical was administered intravenously to male and female Beagle dogs at dose levels of 0.3, 0.5, or 2.5 mg/kg. Mortalities, clinical findings, and body weight changes were monitored for the 14-day period following the administration. At the end of 14-day observation period, all animals were sacrificed and complete gross postmortem examinations were performed. All males and females of the 2.5 mg/kg dose group were found dead between the fourth and seventh day after the injection.

Investigation of acute and subchronic (chronic) toxicity of complexinates of trace elements in experiments with calves was realized in the conditions of the Republic of Belarus. The realized experiments were based on developed in Belarus veterinary preparations for the treatment and prevention of diseases connected with disorders of trace elements exchange containing chelate compounds of trace elements with sodium ethylene diamine acetate: Cuprovet (on the basis of CuNa); Cobalvet (on the basis of CoNa), Zinkovet (on the basis of ZnNa), and Feravet (on the basis of FeNa). There were the following indexes of ferrum in nephros - 55,3 +/- 2,26, in muscles - 134 +/- 26,6 mkg/g, and in liver - 565 +/- 35,5 mkg/g after administration of Feravet. There were the following index of zinc in nephros - 56,3 +/- 2,64, in muscles -25, 8 +/- 1,23 and in liver - 84,4 +/- 3,29 mkg/g after administration of Zinkovet. There were the following indexes of cuprum in nephros - 4,1 +/- 0,325, in muscles - 2,33 +/- 0,117, and in liver - 12,3 +/- 1,12 mkg/g after administration of Cuprovet. There were the following indexes of cobalt in nephros - 40,35 +/- 2,29, in muscles - 12,5 +/- 0,98, and in liver - 126,5 +/- 10,45 ng/g after administration of Cobalvet. Parameters of toxicity of all preparations were by the example of laboratory mice, rats and calves given. Content of trace elements in blood of calves in dynamics of the experiment was analyzed. There were determined parameters of acute toxicity of the analyzed preparations: they all could be referred to substance hazard category 4 (low-hazardous substances). The determined parameters of acute toxicity made it possible to recommend them for treatment and prophylaxis of microelementoses of cattle, as well as to use them as feed additives taking into consideration that defect action levels of the analysed preparations exceed the deficiency needs of cattle in case of their limited cumulation

Evaluation of safety and efficiency of application of immunostimulative drug Izambenum (C14H15IN2O) for stimulation of natural resistance (autarcesis) and immunologic responsiveness of chickens of laying breeds was realized in the conditions of the Republic of Belarus. Clinical and experimental investigation of Izambenum influence on poultry for the increasing of their resistance, activation of immunological response to vaccination against Newcastle disease, stimulation of their growth and development was realized. Research results showed that Izambenum influenced on level of morphological indexes of chicken blood: number of erythrocytes increased on 24%, hemoglobin - on 17%. Total protein in blood serum increased in all test period and number of lymphocytes increased and differential was 90-100%. Izambenum increased strains of post vaccination immunity to Newcastle disease. Bacterial growth-inhibitory activity decreased on the 27the day of life and increased at the same positions on the 34-41 days. Phagocyte activity of pseudoeosinophils increased in all test groups. Research results showed that Izambenum rendered growth and immunity stimulation action and increased their viability. Its immunostimulative action was conditioned by strengthening of cellular and to lower extent humoral immunity factors. Application of the preparation in period of Newcastle disease vaccination promoted the formation of long-lived immunity

Investigation of acute sub-acute toxicity of preparative forms (herbal infusion, tincture liquid extract and pulvis) of marsh cinquefoil (Comarum palustre) by the example of laboratory animals was realized in the conditions of the Republic of Belarus. White mice of both sexes with body weight of 18-20 g and white rats with body weight of 180-200 g were used in the experiment. Experimental preparations were administrated on empty stomach after 12 hours of absolute diet. The animals were supervised in course of 14 days. All changes in behavior were registered. Calculations of parameters of acute and average toxicity of all analyzed forms were presented. Research results showed that all analyzed preparative forms could be referred to the substances hazard category 4 (low-hazardous substances) with lethal dose 50 more than 5000 mg/kg of live weight. It was determined that the analyzed preparative forms proved to be highly effective against strongylatosis (Strongylata) of gastro-intestinal tract of sheep and calves