Histopathological changes in thymus in broiler poisoned with nitrates

This study was carried out on 90 broiler chicks which divided into three groups. The first group has been given 0.75 g/L potassium nitrate and the second group was given 1 g/L potassium nitrate with drinking water for 30 days, While the third group was regarded as a control. The birds were reared in same keeping house and feeded with the same ration without any additives and no vaccinations were applied. All birds were sacrificed and examined by naked eye. Then the thymus gland was fixed by formalin and stained microscopic sections were examined by microscope. The histological changes in the birds which dosed by 1 g/L and 0.75 g/L of nitrate were similar and the observed changes were the small size of cortex in some lobules, and the cortex were separated from bulb with increase the number of Hassall bodies in the bulb region, also there were vacuoles and reticular cells in different stages of degeneration and edema in the connective tissues in comparison with control group. These results confirmed that nitrate had toxic effects on the tissues of thymus, and as a sequence reduced the number of T cells which lead to decrease the resistance and Immune response of the birds and retarded the growth rate.

Comparison between the concentrations of some pollutants in drinking water from distribution system and bottled water

Alsin Spring is the most important water sources in Syrian coastal area, due to it is the source of drinking water for the main cities and towns in the Syrian coast. This research aimed to study some contaminant indicators in Alsin spring and some taps of distribution system of Alsin drinking water, and compare the Indicators with samples of bottled drinking water from Alsin spring and three other water sources (Drekish, Bukkeen, and Alfigeh). The study included determining the concentrations of nitrates, nitrites and some heavy metals including lead, cadmium and nickel in water samples. The results showed that all water sources contain varying concentrations of lead, while the nickel and cadmium were vary in drinking water samples; The concentrations of nickel and cadmium in some samples were low while were under the detection limits in other samples. The analysis of samples of bottled drinking water showed that the samples from Alfigeh spring were the lesser contamination with heavy metals, while the samples from Alsin spring were contain highest concentrations of lead and nickel. The samples of bottled water from Bukkeen spring contain the highest level of cadmium. The results showed that the concentrations of nitrate, nitrite and heavy metals differ depending on the water source. However, all these concentrations were lower and within the acceptable limits of Syrian standard for drinking water. The study concluded that water resources in the coastal area are distinguished with their higher pure.

Choising the alternative conditions for the continuity of the work of the nitrate-selective electrode

Due to the absence of operational requirements and its unidentified solutions ,this study presented definition alternative analytical and technical conditions for the continuation of nitrate-selective electrode working. Many electrolytes were tested (ammonium sulfate, ammonium acetate and ammonium chloride). The technical and analytical conditions shows that the best response which give the Nernst slope of the electrode had been obtained by adding 0.5ml of ammonium sulfate (3mol / l), and the response time was 20sec, by the time that values stabilized for 15sec. The study of pH effect on the electrode response also showed that electrode works within the range (2-8) of pH and that the best response was at pH = 5.5 by using acetic acid-sodium acetate buffer. The effect of temperature on the potential electrode was studied ,it showed that the Nernest electrode response realized within the range (18-37) C0of temperature.While Studying the effect of some interfering ions such as (OH-, HCO3 -, CO3 2-,Cl-,NO2 -) on the work of the electrode showed low values of the coefficient of selectivity, which did not exceed 3×10-2 that the electrode was not affected by the presence of these ions. The chosen conditions were experimented on standard solutions, which showed that the electrode is working within the range (10-4-10-1) mol / l of concentrations. When the concentrations was about 10-5mol/l or less than that, it was necessary to soak the electrode in solution which has low concentration for at least one hour, and diluted the taken volumes ten times . These technical and analytical conditions was applied on standard solutions and environmental samples(water), which showed the accuracy ,correctly and authenticity of the measurements.