An Invertebrate Model of the Developmental Neurotoxicity of Insecticides: Effects of Chlorpyrifos and Dieldrin in Sea Urchin Embryos and Larvae

Chlorpyrifos targets mammalian brain development through a combination of effects directed at cholinergic receptors and intracellular signaling cascades that are involved in cell differentiation. We used sea urchin embryos as an invertebrate model system to explore the cellular mechanisms underlying the actions of chlorpyrifos and to delineate the critical period of developmental vulnerability. Sea urchin embryos and larvae were exposed to chlorpyrifos at different stages of development ranging from early cell cleavages through the prism stage. Although early cleavages were unaffected even at high chlorpyrifos concentrations, micromolar concentrations added at the mid-blastula stage evoked a prominent change in cell phenotype and overall larval structure, with appearance of pigmented cells followed by their accumulation in an extralarval cap that was extruded from the animal pole. At higher concentrations (20-40 microM), these abnormal cells constituted over 90% of the total cell number. Studies with cholinergic receptor blocking agents and protein kinase C inhibitors indicated two distinct types of effects, one mediated through stimulation of nicotinic cholinergic receptors and the other targeting intracellular signaling. The effects of chlorpyrifos were not mimicked by chlorpyrifos oxon, the active metabolite that inhibits cholinesterase, nor by nonorganophosphate cholinesterase inhibitors. Dieldrin, an organochlorine that targets GABA(A )receptors, was similarly ineffective. The effects of chlorpyrifos and its underlying cholinergic and signaling-related mechanisms parallel prior findings in mammalian embryonic central nervous system. Invertebrate test systems may thus provide both a screening procedure for potential neuroteratogenesis by organophosphate-related compounds, as well as a system with which to uncover novel mechanisms underlying developmental vulnerability

The sea urchin embryo, an invertebrate model for mammalian developmental neurotoxicity, reveals multiple neurotransmitter mechanisms for effects of chlorpyrifos: Therapeutic interventions and a comparison with the monoamine depleter, reserpine

Lower organisms show promise for the screening of neurotoxicants that might target mammalian brain development. Sea urchins use neurotransmitters as embryonic growth regulatory signals, so that adverse effects on neural substrates for mammalian brain development can be studied in this simple organism. We compared the effects of the organophosphate insecticide, chlorpyrifos in sea urchin embryos with those of the monoamine depleter, reserpine, so as to investigate multiple neurotransmitter mechanisms involved in developmental toxicity and to evaluate different therapeutic interventions corresponding to each neurotransmitter system. Whereas reserpine interfered with all stages of embryonic development, the effects of chlorpyrifos did not emerge until the mid-blastula stage. After that point, the effects of the two agents were similar. Treatment with membrane permeable analogs of the monoamine neurotransmitters, serotonin and dopamine, prevented the adverse effects of either chlorpyrifos or reserpine, despite the fact that chlorpyrifos works simultaneously through actions on acetylcholine, monoamines and other neurotransmitter pathways. This suggests that different neurotransmitters, converging on the same downstream signaling events, could work together or in parallel to offset the developmental disruption caused by exposure to disparate agents. We tested this hypothesis by evaluating membrane permeable analogs of acetylcholine and cannabinoids, both of which proved effective against chlorpyrifos- or reserpine-induced teratogenesis. Invertebrate test systems can provide both a screening procedure for mammalian neuroteratogenesis and may uncover novel mechanisms underlying developmental vulnerability as well as possible therapeutic approaches to prevent teratogenesis

Images denoising in case impulse noise using spline approximation

Analytical equations of a new spline approximation method for filtering impulse noise in images are obtained. The proposed method differs from the known ones: when filtering images, one-dimensional sequential spline functions are used for direct and inverse transformations, and the processing is performed in rows and columns. In this work, experimental studies based on computer simulation using special test images on the background of impulse noise were conducted. Experimental studies have shown the operability and high efficiency of the developed method, which allow to improve the quality of image filtering by up to 10 dB. In this case, the properties of spline functions make it possible to abandon the use of various masks, that is, to abandon inefficient linear methods of image filtering. The method can be used to create digital image processing systems in the industry, to create autonomous robots, under observation conditions that complicate the registration process, and in the absence of a priori information about the form of background noise

Identification of television images in vision systems based on mathematical apparatus of cubic normalized B-splines

Introduction. The solution to the problem of television images identification under the creation of autonomous robots, vision systems, and noisy image analysis systems is considered. The question is, for example, on severe observing conditions hindering the registration process, and null aprior information on the type of background noise. The work objective is to develop and evaluate the efficiency of the method for image edge detection (two-dimensional signal) against the background of pulse noise using the mathematical apparatus of cubic B-splines. Materials and Methods. Involving intense background noise, spline-approximation of discrete values of signals and images is usually unproductive and leads to raw errors. In this case, the method of differentiating the image line against the noise background allows calculating the signal derivative with sufficient accuracy. Taking into account the information on the behavior of the first derivative, local maxima in the image line against the noise background are defined. The task of television image edge detection is solved by a new technique of spline-differentiation. For this, the image matrix is divided into lines and columns; the differentiation is performed; and then the edge extraction operators are calculated. Unlike the known approaches, the differentiation takes into account data on the intensity in the whole image line. This minimizes the noise effect. Image edges are defined using an intensity gradient. The resulting spline-differentiation algorithm is used for mathematical modeling. Research Results. The authors of the paper for the first time propose a high-precision method of digital differentiation of two-dimensional signals. This approach allows calculating values of the two-dimensional signal derivative and its gradient with sufficiently high accuracy. With that, there is no need to use standard numerical differentiation procedures which are incorrect in themselves. Lena test image distorted by pulse noises of “dead pixels” and “salt-pepper” is processed by the Sobel operator and the spline-differentiation method. Values of еско , SNR and SNRF are tabulated and analyzed. For the Lena test image, the gain in decibels was as follows: according to the MSD (mean-square deviation) - 1.6 ÷ 2.7; relative to peak signal/ SNR noise ratio - 8 ÷ 9.4; relative to peak signal/ MSD noise of SNRF background - 11 ÷ 12. Discussion and Conclusions. Under the conditions of rapid development of microtechnology, the problems solved with the help of vision systems take a new way of application. This proves the relevance of research in the field of increasing the efficiency and stability of methods and algorithms for digital processing of two-dimensional signals. The experiments show that the presented technique has considerably higher noise immunity than algorithms based on standard differentiation procedures

Images denoising in case impulse noise using spline approximation

Analytical equations of a new spline approximation method for filtering impulse noise in images are obtained. The proposed method differs from the known ones: when filtering images, one-dimensional sequential spline functions are used for direct and inverse transformations, and the processing is performed in rows and columns. In this work, experimental studies based on computer simulation using special test images on the background of impulse noise were conducted. Experimental studies have shown the operability and high efficiency of the developed method, which allow to improve the quality of image filtering by up to 10 dB. In this case, the properties of spline functions make it possible to abandon the use of various masks, that is, to abandon inefficient linear methods of image filtering. The method can be used to create digital image processing systems in the industry, to create autonomous robots, under observation conditions that complicate the registration process, and in the absence of a priori information about the form of background noise

Development of Thermal Installation on the Basis of the Cascade Heat Pump for Ensuring All Thermal and Refrigerating Needs of the Consumer

This article describes the developed and manufactured multifunctional heat point, which allows to supply heat and refrigeration energy to consumers. For effective operation, the heat point contains an automated control system that allows to direct heat flows in an optimal way. Development of this thermal point began because in Russia there are no complex researches on creation of systems of power supply on the basis of heat pumps now. There are some works which actually copy the western technologies. At the same time, features of climatic zones are not considered that is extremely important for the development of similar power stations. That is, earlier nobody created a product which equally well works in the conditions of the Southern regions and Far North. Thermal and hydraulic calculations of thermal point were executed. Coefficients of performance and resistance of the contours of the heat pumping plant were the results of these calculations. These calculations showed that the transformation coefficient on all contours is in the range from3.352 to 4.884. Now starting tests of the thermal point which showed a regularity of the chosen design decisions and operability of the installation are carried out.The received results will be useful at projection of similar systems as the main characteristics of cascade heatpumping plants are received by a calculated path.The concrete received results of a research are as follows:– the multipurpose thermal point allowing to carry out heating – 25 kW, hot water supply – 5 kW, conditioning – 16 kW, ventilation of 25 kW is developed;– key indicators of thermal effectiveness of the power station, such as transformation coefficient, thermal rating etc are defined;– capacity of compact accumulators of warmth is determined. Heating with the temperature of 35 оС, within 12 hours of night-time requires the boiler tank of 2500 l whereas the accumulator on change phase of 300–500 l;– on the basis of the analysis of available renewable and secondary energy sources the structure of heat fluxes of the standard consumer with sources of excess warmth and points of its consumption is develope

A New Method for the Visualization of Living Dopaminergic Neurons and Prospects for Using It to Develop Targeted Drug Delivery to These Cells

This is the first study aiming to develop a method for the long-term visualization of living nigrostriatal dopaminergic neurons using 1-(2-(bis(4-fluorophenyl)methoxy)ethyl)-4-(3-phenylpropyl)piperazine-BODIPY (GBR-BP), the original fluorescent substance, which is a derivative of GBR-12909, a dopamine uptake inhibitor. This method is based on the authors’ hypothesis about the possibility of specifically internalizing into dopaminergic neurons substances with a high affinity for the dopamine transporter (DAT). Using a culture of mouse embryonic mesencephalic and LUHMES cells (human embryonic mesencephalic cells), as well as slices of the substantia nigra of adult mice, we have obtained evidence that GBR-BP is internalized specifically into dopaminergic neurons in association with DAT via a clathrin-dependent mechanism. Moreover, GBR-BP has been proven to be nontoxic. As we have shown in a primary culture of mouse metencephalon, GBR-BP is also specifically internalized into some noradrenergic and serotonergic neurons, but is not delivered to nonmonoaminergic neurons. Our data hold great promise for visualization of dopaminergic neurons in a mixed cell population to study their functioning, and can also be considered a new approach for the development of targeted drug delivery to dopaminergic neurons in pathology, including Parkinson’s disease

GPR55 Receptor Activation by the N-Acyl Dopamine Family Lipids Induces Apoptosis in Cancer Cells via the Nitric Oxide Synthase (nNOS) Over-Stimulation

GPR55 is a GPCR of the non-CB1/CB2 cannabinoid receptor family, which is activated by lysophosphatidylinositol (LPI) and stimulates the proliferation of cancer cells. Anandamide, a bioactive lipid endocannabinoid, acts as a biased agonist of GPR55 and induces cancer cell death, but is unstable and psychoactive. We hypothesized that other endocannabinoids and structurally similar compounds, which are more hydrolytically stable, could also induce cancer cell death via GPR55 activation. We chemically synthesized and tested a set of fatty acid amides and esters for cell death induction via GPR55 activation. The most active compounds appeared to be N-acyl dopamines, especially N-docosahexaenoyl dopamine (DHA-DA). Using a panel of cancer cell lines and a set of receptor and intracellular signal transduction machinery inhibitors together with cell viability, Ca2+, NO, ROS (reactive oxygen species) and gene expression measurement, we showed for the first time that for these compounds, the mechanism of cell death induction differed from that published for anandamide and included neuronal nitric oxide synthase (nNOS) overstimulation with concomitant oxidative stress induction. The combination of DHA-DA with LPI, which normally stimulates cancer proliferation and is increased in cancer setting, had an increased cytotoxicity for the cancer cells indicating a therapeutic potential

GPR55 Receptor Activation by the <i>N</i>-Acyl Dopamine Family Lipids Induces Apoptosis in Cancer Cells via the Nitric Oxide Synthase (nNOS) Over-Stimulation

GPR55 is a GPCR of the non-CB1/CB2 cannabinoid receptor family, which is activated by lysophosphatidylinositol (LPI) and stimulates the proliferation of cancer cells. Anandamide, a bioactive lipid endocannabinoid, acts as a biased agonist of GPR55 and induces cancer cell death, but is unstable and psychoactive. We hypothesized that other endocannabinoids and structurally similar compounds, which are more hydrolytically stable, could also induce cancer cell death via GPR55 activation. We chemically synthesized and tested a set of fatty acid amides and esters for cell death induction via GPR55 activation. The most active compounds appeared to be N-acyl dopamines, especially N-docosahexaenoyl dopamine (DHA-DA). Using a panel of cancer cell lines and a set of receptor and intracellular signal transduction machinery inhibitors together with cell viability, Ca2+, NO, ROS (reactive oxygen species) and gene expression measurement, we showed for the first time that for these compounds, the mechanism of cell death induction differed from that published for anandamide and included neuronal nitric oxide synthase (nNOS) overstimulation with concomitant oxidative stress induction. The combination of DHA-DA with LPI, which normally stimulates cancer proliferation and is increased in cancer setting, had an increased cytotoxicity for the cancer cells indicating a therapeutic potential