Heat shock induces variably the major heat shock proteins of CV1 clones

AbstractCV1 cells have been subcloned several times. Five of these clones were studied for the induction of the major heat shock proteins. These CV1 clones exhibit morphological differences as well as differences in SDS-PAGE protein profiles. These clones responded to heat shock variably as judged from the induction of the major heat shock proteins, 70, 72 and 92 kDa. Variable expression of the heat shock proteins suggests that the selective pressure for isolation of cell clones may affect gene expression differently

Effect of 910-MHz Electromagnetic Field on Rat Bone Marrow

Aiming to investigate the possibility of electromagnetic fields (EMF) developed by nonionizing radiation to be a noxious agent capable of inducing genotoxicity to humans, in the current study we have investigated the effect of 910-MHz EMF in rat bone marrow. Rats were exposed daily for 2 h over a period of 30 consecutive days. Studying bone marrow smears from EMF-exposed and sham-exposed animals, we observed an almost threefold increase of micronuclei (MN) in polychromatic erythrocytes (PCEs) after EMF exposure. An induction of MN was also observed in polymorphonuclear cells. The induction of MN in female rats was less than that in male rats. The results indicate that 910-MHz EMF could be considered as a noxious agent capable of producing genotoxic effects

Interactions of embryonic with neoplastic cells

Adhesive interactions of embryonic with neoplastic cells have been studied in cultures of 7 day old chick embryo neural retina cells and embryo hamster, baby hamster cell lines and some of their neoplastic derivative cell lines. Two futures of adhesion were studied, the alteration of neural retina cell adhesiveness by the conditioned media of the hamster cell lines and the mutual adhesiveness of the neural retina cells and the hamster cell linos. Experiments to test for conditioned media were done using either the Couette Viscometers or the collecting cell lawn assay. The results of these experiments indicate the presence of factors which affect the adhesiveness of 7 day old chick embryo neural retina cells. The results varied depending upon which technique was used. The mutual adhesiveness of the neural retina cells and the hamster cell lines was studied with the collecting cell lawn system and in two and three dimensional mixed cultures. The collecting ceil lawn assay indicates that the neural retina cells do not associate with the neoplastic cells as well as the normal cells and that the embryonic hamster cells associate better than the baby hamster cells. The results are discussed on the bases of a classification of the different cell types according to their origin as baby, embryonic or neoplastic cells. The two dimensional mixed cultures show that the neural retina cells and the hamster cells do not make any important contacts and that the increase by growth of the number of the hamster cells force the neural retina cells to come off the culture dishes. The three dimensional mixed cultures indicate that the neural retina cells associate to some extent with the normal baby and embryonic hamster cells but not with the neoplastic ones. In these mixed cultures two and three dimensional ones, the sorting out pattern observed was discussed in relation to the secretion effects. The results give support to the "morphogen theory" for the control of sorting out in mixed aggregates

Differential Micronuclei Induction in Human Lymphocyte Cultures by Imidacloprid in the Presence of Potassium Nitrate

Humans are exposed to pesticides as a consequence of their application in farming or their persistence in a variety of media, including food, water, air, soil, plants, animals, and smoke. The interaction of pesticides with environmental factors may result in the alteration of their physicochemical properties. Square wave cathodic stripping voltammetry (SW-CSV), a technique that simulates electrodynamically the cellular membrane, is used to investigate whether the presence of potassium nitrate (KNO3) in the culture medium interferes with the genotoxic behavior of imidacloprid. The cytokinesis block micronuclei (CBMN) method is used to evaluate imidacloprid's genotoxicity in the absence or presence of KNO3 in the culture medium and, as a consequence, its adsorption by lymphocytes. Comparing micronuclei (MN) frequencies in control and imidacloprid-treated blood cell cultures, statistically significant differences were not detected. KNO3 did not induce MN frequencies compared to control. Statistically significant differences in MN frequencies were observed when blood cell cultures were treated with imidacloprid in the presence of increasing concentrations of KNO3. SW-CSV revealed that by increasing KNO3 molarity, imidacloprid's concentration in the culture medium decreased in parallel. This finding indicates that imidacloprid is adsorbed by cellular membranes. The present study suggests a novel role of a harmless environmental factor, such as KNO3, on the genotoxic behavior of a pesticide, such as imidacloprid. KNO3 rendered imidacloprid permeable to lymphocytes, resulting in elevated MN frequencies

Pythagoras project: Development of an innovative training package on Indoor Environment Quality

The aim of the Pythagoras project is the development and assessment of Greek national training material in the sector of indoor environmental quality. The need for education in this specific sector is dictated by the significant indoor environment deterioration and associated health hazards, which are caused by low ventilation levels, combined with the use of many modern building materials that aggravate pollutants emissions. Early in the project, a review is undertaken of the international literature and the syllabuses of foreign research and educational institutions active in indoor environment quality issues. At the same time, the requirements of the Greek educational and broader society, related to issues of indoor pollution and health, are determined. A training methodology is consequently developed, with the objective to optimally cover all the parameters associated with the indoor environment quality, for trainees of various disciplines. The training material is produced both in printed (book) and integrated electronic (e-learning) format. Additionally, four seminars are organized covering the respective sections of the training package. The training package is being assessed both by the trainees but also by international experts in the sector of indoor environment quality

The use of premature chromosome condensation to study in interphase cells the influence of environmental factors on human genetic material

Nowadays, there is a constantly increasing concern regarding the mutagenic and carcinogenic potential of a variety of harmful environmental factors to which humans are exposed in their natural and anthropogenic environment. These factors exert their hazardous potential in humans' personal (diet, smoking, pharmaceuticals, cosmetics) and occupational environment that constitute part of the anthropogenic environment. It is well known that genetic damage due to these factors has dramatic implications for human health. Since most of the environmental genotoxic factors induce arrest or delay in cell cycle progression, the conventional analysis of chromosomes at metaphase may underestimate their genotoxic potential. Premature Chromosome Condensation (PCC) induced either by means of cell fusion or specific chemicals, enables the microscopic visualization of interphase chromosomes whose morphology depends on the cell cycle stage, as well as the analysis of structural and numerical aberrations at the G1 and G2 phases of the cell cycle. The PCC has been successfully used in problems involving cell cycle analysis, diagnosis and prognosis of human leukaemia, assessment of interphase chromosome malformations resulting from exposure to radiation or chemicals, as well as elucidation of the mechanisms underlying the conversion of DNA damage into chromosomal damage. In this report, particular emphasis is given to the advantages of the PCC methodology used as an alternative to conventional metaphase analysis in answering questions in the fields of radiobiology, biological dosimetry, toxicogenetics, clinical cytogenetics and experimental therapeutics

A Firefly Algorithm for the Heterogeneous Fixed Fleet VRP

Abstract: Vehicle routing is a key success factor in logistics problems. A variation of Vehicle Routing problem (VRP), the heterogeneous fixed fleet VRP in which the vehicles available for distribution activities are characterized by different capacities and costs, is tackled. A hybrid firefly algorithm for optimizing the routing of heterogeneous fixed fleet of vehicles in logistics distribution systems is presented. The principles and key steps of the proposed firefly algorithm are introduced in detail. Experimental results from solving the heterogeneous fixed fleet vehicle routing problem when tested on benchmark datasets are demonstrated. Moreover, the algorithm is compared with other algorithms solving similar problems in order to prove the effectiveness of the proposed hybrid firefly algorithm

Dynamic Analysis of DNA Damage by Flow Cytometry and FISH

The micronucleus assay, developed to assess DNA damage induced by noxious agents, supplies information on whether the damage is due to clastogenic or aneugenic action. Although it is the test that can be used to assess agents' toxicity, it cannot provide information on the molecular events that result in the induction of micronuclei. To study the molecular events, the combination of both microscopic and analytical techniques is required. Flow-sorting induced micronuclei, based on their DNA content, in combination with chromosomal FISH and other molecular techniques, may provide information on these events