Plant virus infection development as affected by heavy metal stress

The work was focused on the investigation of possible dependencies between the development of viral infection in plants and the presence of high heavy metal concentrations in soil. Field experiments have been conducted in order to study the development of systemic tobacco mosaic virus (TMV) infection in Lycopersicon esculentum L. cv. Miliana plants under effect of separate salts of heavy metals Cu, Zn and Pb deposited in soil. As it is shown, simultaneous effect of viral infection and heavy metals in tenfold maximum permissible concentration leads to decrease of total chlorophyll content in experiment plants mainly due to the degradation of chlorophyll a. The reduction of chlorophyll concentration under the combined influence of both stress factors was more serious comparing to the separate effect of every single factor. Plants' treatment with toxic concentrations of lead and zinc leaded to slight delay in the development of systemic TMV infection together with more than twofold increase of virus content in plants that may be an evidence of synergism between these heavy metal's and virus' effects. Contrary, copper although decreased total chlorophyll content but showed protective properties and significantly reduced amount of virus in plants.     

Extramedullary hematopoiesis in a case of benign mixed mammary tumor in a female dog: cytological and histopathological assessment

Backgroud  

Extramedullary hematopoiesis (EMH) is defined as the presence of hematopoietic stem cells such as erythroid and myeloid lineage plus megakaryocytes in extramedullary sites like liver, spleen and lymph nodes and is usually associated with either bone marrow or hematological disorders. Mammary EMH is a rare condition either in human and veterinary medicine and can be associated with benign mixed mammary tumors, similarly to that described in this case.     

The duration of the inhibitory effects with static stretching on quadriceps peak torque production

Although several studies have investigated the acute effect of static stretching exercises, the duration of exercises that negatively affects performance has not been ascertained. This study was conducted to determine the acute effect of different static stretching durations on quadriceps isometric and isokinetic peak torque production. The 50 participants were randomly allocated into five equivalent sized groups and were asked to perform a stretching exercise of different duration (no stretch, 10-second stretch, 20-second stretch, 30-second stretch, and 60-second stretch). The knee flexion range of motion and the isometric and concentric isokinetic peak torques of the quadriceps were measured before and after a static stretching exercise in the four experimental groups. The same parameters were examined in the control group (no stretch) without stretching, before and after a 5-minute passive rest. There were no significant differences among groups before the experimentation regarding their physical characteristics and performances (P > 0.05). These results reflect the different groups' homogeneity. Significant knee joint flexibility increases (P < 0.001) and significant isometric and isokinetic peak torque reductions (P < 0.05-0.001) have been shown to occur only after 30 and 60 seconds of quadriceps static stretching. Stretching reduced isometric peak torque by 8.5% and 16.0%, respectively. Concerning isokinetic peak torque after 30 and 60 seconds of stretching, it was reduced by 5.5% vs. 11.6% at 60 degrees/s and by 5.8% vs. 10.0% at 180 degrees/s. We suggest that torque decrements are related to changes of muscle neuromechanical properties. It is recommended that static stretching exercises of a muscle group for more than 30 seconds of duration be avoided before performances requiring maximal strength.     

New revival of an old biomarker: characterisation of buccal cells and determination of genetic damage in the isolated fraction of viable leucocytes

Buccal cells serve as targets to assess oral exposures. We have refined isolation methods to characterise yield, viabilities, types of cells and baseline levels of genetic damage. Buccal cells were isolated from mouthwashes of 27 volunteers. They were characterised microscopically and different methods (using antibody-labelled magnetic beads, filtration and gradient centrifugation) were compared to separate epithelial cells from leucocytes. Viability of cells, DNA damage, and activity of glutathione S-transferase (GST) were measured with dye exclusion, microgelelectrophoresis, and biochemically. Mouthwashes contained approximately equal amounts of epithelial cells and leucocytes with detectable GST-activities. Repetitive determinations with mouthwashes from four individuals yielded per sample (3.5+/-1.4)x10(6) epithelial cells and (4.7+/-3.9)x10(6) leucocytes with viabilities of 8 and 94%, respectively. Epithelial cells could not be isolated using antibody-labelled beads, but cell separation with the leukocyte-specific antibody CD45 succeeded, yielding 37% leucocytes with a purity of 95% and viability of 65%. Filtering the mouthwash through a 10 microm filter yielded 57% leucocytes, with 86% purity and 94% viability. When using density gradient centrifugation as the separation method, the recovery of leucocytes was low (22%), but good results were scored for purity (95%) and cell viability (88%). This method was used to isolate leucocytes, which were then subjected to a micro-scale comet assay-modification. It was found that buccal leucocytes obtained from smokers had more DNA damage than cells from non-smokers. In conclusion, suspensions of buccal cells consist in approximately equal parts of epithelial cells and leucocytes. Only leucocytes are sufficiently viable for measuring parameters of cytotoxicity and genotoxicity or for studying modulation of gene expression. The cells are useful targets of non-invasive biomarkers, which could be incorporated as tools in many types of intervention studies.     

Studies on the partial characterization of extracted glycosaminoglycans from fish waste and its potentiality in modulating obesity through in-vitro and in-vivo

Glycoconjugate Journal - Glycosaminoglycans (GAGs) are bioactive polysaccharides or glycoconjugates found in the fish waste having significant health impacts. In the present study it has been...     

Yield and quality of forage maize (<i>Zea mays</i> L.) with different levels of subsurface drip irrigation and plant density

The scarcity of water in arid and semiarid regions of the world is a problem that every day increases by climate change. The subsurface drip irrigation (SDI) and changes in population density of plants are alternatives that can be used to make a sustainable use of water. Therefore, the objectives of this study were to determine the combination that allows for an increased corn performance and efficient use of water without losing the quality of forage. Three different irrigation levels were applied through a system of a SDI at three different densities of forage maize plants in an arid region. The results demonstrated that by applying different levels of water, either enough or lack of soil moisture is created, which is directly reflected in crop yield, and its determining variables such as green forage and dry matter yield, and nutritional quality. The irrigation level to a 100% of potential evapotranspiration (PET), at a density of 80000 plants/ha, increased yield of green forage to 57664 kg/ha; crude protein was 8.59%, while the rest of the quality parameters decreased. This study allowed to conclude that the irrigation level was the major factor in the response of the crop.