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The effect of gamma radiation with 0, 200, 250, 300, 350, 400, and 450 Gy intensities on the longevity, total number of eggs, and the percent of hatched eggs laid by irradiated females of Tetranychus urticae Koch (Tetranychidae) was evaluated. Two different groups (0–24 h old and 48–72 h old) of adult females were irradiated. The results showed that 350 and 300 Gy doses significantly reduced the longevity of the 0–24 h old females and the 48–72 h old females. The younger females were more tolerant at lower dose rates than the older females. There was a quadratic relationship between dose rates and young females, while it was linear in older females. The total number of eggs laid by females of both ages was significantly reduced with a linear trend by 250 Gy irradiation. The eggs laid by females of both the 0–24 h olds and the 48–72 h olds lost their hatchability when the dose rate was 350 Gy. It was concluded, that applying a dose rate of 320 Gy on one of the mates (male or female) before mating, or a 300 Gy on both of them, would be sufficient to cause sterility in adult mites.
Turkish fermented sausages are one of the commonly consumed meat products in Turkey. In this study the effects of low dose gamma irradiation (1, 2 and 3 kGy) on the microbiological quality properties of Turkish fermented sausages have been investigated. The numbers of total aerobic mesophilic bacteria, coliform, Staphylococcus aureus, mould, yeast, lactic acid bacteria, and sulphite reducing Clostridia were analyzed. In sausage samples it was determined the number of microorganisms decreased or were eliminated according to the increased doses of gamma irradiation. The dose of 1 kGy was sufficient to eliminate the yeasts and sulphite reducing Clostridia. Coliforms and moulds were reduced to under detectable values after the application of 2 kGy irradiation doses, Staphylococcus aureus and lactic acid bacteria by the application 3 kGy. It was concluded that the 2 kGy dose was sufficient to control bacterial population to maintain Turkish fermented sausages within designated standards for this product.
The protective action of passive saline filled ("empty") phosphatidylcholine liposomes (PCL) on endothelial function was examined in thoracic aortas obtained from gamma irradiated (6 Gy) Chinchilla rabbits, and then verified in experiments on non-anesthetized and anesthetized rats. Acetylcholine (ACh)-induced vascular relaxant responses in isolated vascular tissues rats were used as the test of endothelial integrity and its functional ability. It was shown that when added to the bath solution (100 µg/ml), PCL effectively restored endothelium-dependent ACh relaxations of isolated vascular rings damaged resulting from -irradiation but had no effect on endothelium-independent vascular responses to therapeutic nitric oxide (NO) donors. The liposomes were also without protective effect when injected to the rabbits intraperitoneally (30 mg/kg) 1 hour before irradiation. In contrast, PCL, being injected at the same dose 1 hour after radiation impact, promote normalization of both endothelium-dependent vascular responses to ACh and nitric oxide (NO) donors. PCL restored also the sensitivity of vascular tissues to authentic NO (aqueous NO solution) that was surprisingly increased after irradiation, and normalized relationship between ACh-stimulated NO release and relaxant response amplitudes in irradiated aortas. Experiments on non-anesthetized and anesthetized rats demonstrated that irradiation led to significant elevation in the level of arterial blood pressure without any changes in cardiac contractility. PCL administration (25 mg/kg, i.v.) effectively normalized an increased arterial blood pressure in irradiated animals. In conclusion, it appears that PCL due to its ability to normalize NO- dependent vascular tone control mechanisms might be worthwhile therapeutic approach in case of ionizing irradiation accident. These result support the concept that the depression of endothelium-dependent vascular responses after irradiation may be result of decreased NO bioavailability due to its conversion to less potent vasodilators during irradiation-induced oxidative attack.
Wheat grain was exposed to gamma ionising irradiation at selected doses between 0.05-10 kGy and microwave radiation from 45 to 180 sec. The sensory evaluation of a grain odour proved that both applied treatments, gamma and microwave irradiation, did not cause significant changes in the grain odour in comparison to control samples of grain with the exclusion of maximum irradiation dose 10 kGy, and maximum microwave heating time 180 sec. The results obtained after measurement of the grain reflected-light showed that gamma 60Co irradiation did not cause any changes in grain colour. The grain after microwave heating at 90, 120, 180 sec was characterised by significantly higher lightness (L*) value. The total colour difference (E) between microwave irradiated samples and the control ones was increasing gradually, with the increase in temperature.
The main aim of this study was to compare the reaction of quiescent and proliferating, i.e. phytohemagglutinin (PHA)-stimulated, human peripheral blood mononuclear cells (PBMCs) to γ-radiation, and analyse changes of proteins related to repair of DNA damage and apoptosis, such as γH2A.X, p53, p53 phosphorylation at serines-15 and -392, and p21 and their dose dependence. Freshly isolated PBMCs in peripheral blood are predominantly quiescent, in G0phase, and with very low amounts of proteins p53 and p21. Using confocal microscopy we detected dose dependent (0.5–5 Gy) induction of foci containing γH2A.X (1 h after γ-ray exposure), which are formed around radiation-induced double strand breaks of DNA. Apoptosis was detected from 24 h after irradiation by the dose of 4 Gy onwards by Annexin V binding and lamin B cleavage. Seventy two hours after irradiation 70% of CD3+lymphocytes were A+. Neither increase in p53 nor its phosphorylation on serine-392 after irradiation was detected in these cells. However, massive increase in p21 (cyclin-dependent kinase inhibitor 1A) was detected after irradiation, which can be responsible for late occurrence of apoptosis in these quiescent cells. PHA-stimulation itself (72 h) caused an increase in early apoptosis (A+PI–) in comparison to non-stimulated PBMCs (38% A+resp. 13.4%). After PHA-stimulation also the amount of γH2A.X, p53, and p21 increased, but no phosphorylation of p53 on serine-392 or -15 was detected. Reaction to γ-radiation was different in PHA-stimulated lymphocytes: the p53 pathway was activated and p53 was phosphorylated on serines-15 and -392 4 h after irradiation by the dose of 4 Gy. Phosphorylation of p53 at serine-15 increased in a dose-dependent manner in the studied dose range 0.2–7.5 Gy. Also the amount of p21 increased after irradiation. Seventy two hours after irradiation of PHA-stimulated CD3+T lymphocytes by the dose of 4 Gy 65% of cells were A+.
The present study was carried out to induce morphological mutation in chilli (Capsicum annuum L.) var k1. The seeds were subjected to different treatment levels of gamma rays are 20, 30, 40, 50, 60 and 70Kr along with control. The treated and untreated seeds were raised in a randomized block design to observe the different morphological characters in M2 generation. Several unique and interesting mutants were isolated in this investigation, these independent mutants have differ from control, the most distinct mutants included tall, dwarf, bushy , flower, sterile and pod mutant, was observed in M2 generation.
The amount of all bases, except for 5,6-dihydroxyuracil were significantly increased in rat DNA upon cobalt-60 y-irradiation. Control values were recovered 12 h after irradiation. The extent of DNA damage and repair was different for particular bases.
A new mathematical equation was developed by which whole-body exposure to gamma radiation may be used to predict the survival characteristic of the intestinal crypt in mice pretreated with N-nitrosodiethylamine (NDEA). A computer fitting procedure showed the best agreement between predicted and observed curves. The results suggest that less cells may survive in crypts after gamma irradiation of NDEA-treated mice.
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