ABSTRACT
Authors performed investigation on "antigen-antibody" interaction of chicken infectious bronchitis coronavirus (IBV) by a method based on the surface plasmon resonance (SPR). Presence of space-size effect related to a difference between antigen and antibody particle sizes has been theoretically grounded and experimentally proven. Herewith, the difference between responses of the SPR-sensor to specific and non-specific interactions is considerably less (up to 6.3 times) than the expected one (8 - 11 times). An impact of functionalization of sensor's sensitive element surface, as well as acidity of buffer solution on the activity of antigen-antibody interaction was studied here. The difference between sensor's responses to specific and non-specific interactions increased two-fold from 200 to 432ang sec due to this treatment. When changing the acidity of analyzed solution from pH7.3 to pH6.8, the corresponding difference between sensor's responses increased by 6.3 times from 194 up to 1235ang.sec. Thus, an impact of space-size effect on interaction between IBV antigen and specific antibody can be considerably (almost in 3 times) decreased by reducing the acidity of used buffer solution. The results of our investigation can be successfully applied to develop new methods for detection of pathogens and specific antibodies using SPR.
Subject(s)
Coronavirus Infections , Infectious bronchitis virus , Animals , Antibodies , Chickens , Coronavirus Infections/veterinary , Surface Plasmon ResonanceABSTRACT
OBJECTIVE: To study the influence of long-term gamma-irradiation with low dose rate (13×10-6 cGy/s) on the body, testes and ventral prostate, development of laboratory rats, as well as quantitative parameters of sperm production along with kinetic characteristics of spermatozoa. MATERIALS AND METHODS: The experiments were performed on laboratory white rats of 2,5 months in age. Animals were irradiated in gamma-field of "Ethalon" device in a dose range 0.1-1.0 Gy. Testicles, epididymises, ventral prostate were retrieved from decapitated animal, each organ weight being determined for every exposure dose. Sperm quantities in testicles and epididymises were identified with aid of phase-contrast microscopy after tissue homogenization in saline containing Troton X-100 and NaN3. Kinetic characteristics of spermatozoa were analyzed by video recording at 37 ºC. RESULTS: The long-term gamma-irradiation with low dose rate was shown to cause no effect on the dynamics of animal weight and weight of epididymis changes. However the testes weight was noticed to diminish at doses 0.1, 0.3, 0.6 and 1.0 Gy, the latter dose being stimulative for the ventral prostate growth and weight accumulation. Total sperm quantities in testicles and epididymices along with daily sperm production declined in gamma-irradiated rats compared to control. However curvilinear and straight line spermatozoid velocity as well as the frequency of tail oscillations tended to increase. CONCLUSIONS: Long-term gamma-irradiation of rat whole body with low dose rate just insignificantly affects the development of testes and ventral prostate. Apart from this, radiation effects showed up in sperm production slight suppression, from the on hand, and sperm velocity along with tail oscillations intensification, from the other hand.
ABSTRACT
OBJECTIVE: To study dynamics of natural antioxidant levels and antioxidant enzymes activities in rabbit seminal fluid in conditions of single total body X-ray irradiation in different doses. Materials and methods. Soviet Shinshilla white rabbit males 30-36 months old were taken into investigation. Sperm was collected by artificial vagina. Seminal fluid was purified from spermatozoa by centrifugation at 2500g during 12 min. Animals were irradiated by X-rays on RUM-17 device (Russia) in doses 1.0; 2.0; 5.0 and 7.0 Gy with dose rate 2.8x10-3 Gy/sec. Sperm was gathered on 10th and 90th day after irradiation. Free glutathione and thiol concentration were assessed by spectrophotometry using 2.2-dithiobisnitrobenzoic acid, lipid peroxidation was evaluated by measuring of TBA-active products concentration. Enzymatic activities of superoxiddismutase, catalase, glutathionperoxidase and glutathionreductase were estimated in substrate specific reactions spectrophotometrically. Results. Dose-dependant up-regulation of antioxidant enzymatic activity of seminal fluid on the 10th day after exposure to 1.0-7.0 Gy dose range of total X-ray irradiation was shown. This effect was accompanied by the decrease of free thiols concentration, from the one hand, and both TBA-active products and oxidized glutathione contents elevation, from the other hand. This seminal plasma state was shown to be temporal and partially normalized on 90th day after exposure. Conclusions. Total X-ray irradiation of rabbits leads to significant up-regulation of antioxidant processes of both enzymatic and non-enzymatic type on the 10th day after radiation exposure in seminal plasma. This effect was shown to be dose-dependant. Then antioxidant activity dropped and metabolic activities gradually normalized according to studied parameters within 90 days after exposure in 1.0 and 2.0 Gy.
