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Evaluation Of Genetoxic Effect Of Radiation Over Vegetal Embryos In Species With Different Radiosensibilities

Abstract

This study presents the effects induced by X-rays, medium doses (20-70 Gy), over the meristematic tissues of three cereal species: one of barley and two of wheat. The cytogenetic investigation was based on the response of young seedlings during their very early ontogenetic stages to the ionizing radiation exposure. The study was focused on the identification and counting of the chromosomal aberrations for various doses compared to the control samples. Qualitative evaluation revealed: interchromatidian bridges, expulsed chromosomes or chromosome fragments, and complex aberrations (combination of the already mentioned ones). The different behavior of these three species was discussed over the mitotic index, the number of abnormal ana-telophases and over the percentages of the mitosis phases. In each case, the mitotic index was increased in comparison with the control, and also the number of aberrations was found increased; however no evident mathematical correlations with applied doses could be established.

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Assessment of Potential Clastogenic Effect of the Insecticide Mospilan® 20SP in Human Peripheral Blood Lymphocytes After in Vitro Exposure

Abstract

Acetamiprid, that is known as the commercial formulation Mospilan® 20SP is the part of the neonicotinoid insecticide group and is widely used against various pests. In our study we assessed the potential clastogenic effects of Mospilan® in human peripheral blood lymphocytes in vitro using a chromosome aberration test. The lymphocytes were treated with acetamiprid in the concentration range of 5, 10, 25 and 50 µg.ml−1 for 24 and 48 h. After 24 h exposure, the insecticide induced statistically significant higher levels of chromosome aberrations from the concentration of 10 µg.ml−1 (P < 0.05 and P < 0.001) and a significant decrease in mitotic index (MI) at the concentrations of 25 and 50 µg.ml−1 (P < 0.05 and P < 0.01), respectively. After a 48 h exposure, we found a dose dependent increase in the percentage of chromosome aberrations at all concentrations (P < 0.05; P < 0.01 and P < 0.001) and a decrease in MI at concentrations of 25 and 50 µg.ml−1 (P < 0.05 and P < 0.01). Our results indicated that neonicotinoid insecticide formulations containing acetamiprid may have potential cytotoxic and genotoxic effects.

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Responses of Two Barley Subspecies to In vitro-Induced Heavy Metal Stress: Seeds Germination, Seedlings Growth and Cytotoxicity Assay

Abstract

In this work three heavy metals: cadmium (as CdSO4), cobalt (as CoCl2) and zinc (as ZnSO4), were used to determine and compare their toxicity towards two subspecies of barley (Hordeum vulgare subsp. vulgare L. and Hordeum vulgare subsp. distichum L.), focusing on seeds germination, seedlings growth, and cytological parameters. The results indicate that the effect of these heavy metals depends on the metal kind, the metal concentrations and the plant subspecies. Generally, in the case of H. vulgare, the heavy metal salts understudy did not influence significantly seed germination and seedling growth parameters. However, these metal salts influence significantly these parameters for H. distichum. The cytological test showed significant decrease (p < 0.05) in the mitotic index among the increase of the heavy metal concentrations when evaluated with the control for H. vulgare and H. distichum. Consequently, H. vulgare seemed to be more tolerant of the increase of the three heavy metals concentrations than H. distichum.

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The Dynamics of Cell Division in Some Local Potato Varieties Cultivated in Vitro on Micropropagation Medium

Abstract

This study was performed to reveal the changes in cell division, as a result of the prolonged period of subculture on micropropagation medium, of five local varieties of Solanum tuberosum L. maintained on in vitro collection at Suceava Genebank, Romania. For this purpose it was used the Murashige-Skoog medium (MS- 1962) with addition of 40 g/l sucrose, and 6 mg/l daminozide. The effect of prolonged period of subculture up to two and 12 months was expressed as mitotic index and frequency of cells with abnormal division. Mitotic index ranged from 20.1 to 22.1% after 12 days, between 15.5 - 17.7% after two months and between 17.7 - 19.2% after 12 months of subculture. The results obtained showed that the frequency of aberrant cells increased with the preservation time on the in vitro cultures and their accumulation rate depended on the genotype. Were identified interphases with micronuclei, metaphases with retarded chromosomes, ana-telophases with chromosomal bridges, retarded chromosomes and chromosomal fragments, but their percentage was low in all the genotypes.

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Disturbance of Cell Proliferation in Response to Mobile Phone Frequency Radiation

Disturbance of Cell Proliferation in Response to Mobile Phone Frequency Radiation

The aim of study was to determine the influence of mobile phone frequency radiation on the proliferation, cytoskeleton structure, and mitotic index of V79 cells after 1 h, 2 h, and 3 h of exposure. V79 cells were cultured in standard laboratory conditions and exposed to continuous-wave (CW) RF/MW radiation of 935 MHz, electric field strength of (8.2±0.3) V m-1, and specific absorption rate (SAR) of 0.12 W kg-1. To identify proliferation kinetics, the cells were counted for each hour of exposure 24 h, 48 h, 72 h, and 96 h after respective exposures. Microtubule proteins were determined using specific immunocytochemical methods. Cell smears were analysed under a fluorescent microscope. The study included negative and positive controls. Mitotic index was determined by estimating the number of dividing cells 24 h after exposure and dividing it with the total number of cells. In comparison to the controls, cell proliferation declined in cells exposed for three hours 72 h after irradiation (p<0.05). Microtubule structure was clearly altered immediately after three hours of irradiation (p<0.05). The mitotic index in RF/MW-exposed cells did not differ from negative controls. However, even if exposure did not affect the number of dividing cells, it may have slowed down cell division kinetics as a consequence of microtubule impairment immediately after exposure.

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Allium cepa root meristem cells under osmotic (sorbitol) and salt (NaCl) stress in vitro

Abstract

The effects of various concentrations of sorbitol (100, 200 and 360 mM) and NaCl (100, 200 and 300 mM) on root meristem cells of in vitro-cultured Allium cepa L. were analyzed after 10 and 20 days. Both root meristem cell cross-section area and nuclear volume decreased under osmotic and salt stress. The osmotic component of applied stresses had a greater impact on cell shrinkage, while ionic stress perturbed cell functioning, resulting in cell cycle arrest and various aberrations, affecting nucleus integrity. A concentration of 300 mM of NaCl in the culture medium caused complete inhibition of mitotic activity in onion root tip cells after 20 days of exposure. Analysis of the action of iso-osmotic concentrations of NaCl (200 mM) and sorbitol (360 mM) showed stronger mitodepressive effects of salt stress in comparison to osmotic stress.

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Malignant Pilomatricoma in a Young Dog

Abstract

Malignant pilomatricoma is malignant follicular tumor with only matrical differentiation. Malignant pilomatricoma is rare in dogs. There is little information about sex, breed and age predisposition. There are a few reports of canine malignant pilomatricoma in middle to old age dogs. However, this neoplasm was resected from 1-year-old intact male miniature poodle. The neoplasm was found in the dorsal part of the neck. The mass was firm and protruded. On gross findings the size of the mass was 3×2×1.5cm. The mass was located in the deep dermis and subcutaneous layer. The mass was composed of several lobules of grey-white chalky material. Microscopically, the mass was composed of several large and small lobules. There were basophilic round to oval basaloid cells at the periphery of the lobules. The basophilic cells showed abrupt keratinization. Numerous ghost cells were observed in the center of the mass. The ghost cells had abundant eosinophilic cytoplasm without a nucleus. The basophilic basaloid cells showed numerous atypical mitotic figures. Cellularity was high and pleomorphism was remarkable. No lymphatic metastasis was observed. We reported a rare case of malignant pilomatricoma in a 1-year-old young dog.

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Assessment of genotoxicity of vincristine, vinblastine and vinorelbine in human cultured lymphocytes: a comparative study

chromatids are darkly stained), and M3 phase cells contain a mixture of lightly stained, darkly stained and differentially stained chromatids [ 26 ]. Cell Kinetics Analysis The mitotic index was calculated by analyzing at least 1000 cells from each subject and scoring the cells that were in metaphase as previously described [ 26 ]. For the cell proliferation index, 100 metaphase cells from each donor were scored. The proliferation index was calculated using the following formula: (1 X M1 + 2 X M2 + 3 X ≥ M3)/100, where M1, M2 and M3 are the number of cells at the

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Detection of Chromosomal Breaks Induced by Thiacloprid in Human Lypmhocytes and Detection of Double-Strand Breaks Based on γH2AX Histone Phosphorylation

Abstract

Thiacloprid, a neonicotinoid insecticide, is widely used to control various species of pests in the current agriculture of today. The potential genotoxic effects of thiacloprid on human peripheral blood lymphocytes were investigated in vitro by chromosome aberrations (CA), and double-strand breaks (DSB), which were detected by the phosphorylation of γH2AX histone. Human peripheral blood lymphocytes were exposed to 30, 60, 120, 240, 480 µg.ml−1 doses for the last 24 and 48 hours of culture. Thiacloprid increased CA at the concentrations of 240, 480 μg.ml−1 (P < 0.05), but these results did not confirm genotoxicity. The mitotic index (MI) was important to us; it served as a basis for the confirmation of the cytotoxicity of this insecticide. During 48 hours of culture, at the concentration of 480 µg.ml−1, its value rapidly decreased (0.42) (P < 0.001), which did not allow us to analyse the results because of the high cytotoxic response.

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Evaluation of the Genotoxic Effect of the Commercial Fungicide Tango® Super on Bovine Lymphocytes

Abstract

This study investigated the potential genotoxic effects of the fungicide Tango® Super using methods of conventional cytogenetic analysis, fluorescence in situ hybridization (FISH) and detection of DNA fragmentation in bovine lymphocytes. After exposure of two donor cell cultures to several concentrations of fungicide (0.5, 3.0 and 15.0 mg.ml-1 for conventional cytogenetic analysis; 0.5 and 3.0 mg.ml-1 for FISH) we detected the insignificant occurrence of chromosome and chromatid breakages. In both donors we observed a significant decrease in mitotic index (MI) percentage with increasing concentrations of fungicide (P < 0.01; P < 0.001), which indicated a cytotoxic effect of the preparation. Electrophoretic analysis of DNA fragmentation in lymphocytes exposed to increasing concentrations (0.5; 1.5; 3.0; 6.0 and 15.0 mg.ml-1) of this preparation showed its ability to induce formation of fragments, which is a characteristic manifestation of the last stage of apoptosis.

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