26 research outputs found

    Prenatal inhibition of the tryptophan–kynurenine pathway alters synaptic plasticity and protein expression in the rat hippocampus

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    Glutamate receptors sensitive to N-methyl-d-aspartate (NMDA) are important in early brain development, influencing cell proliferation and migration, neuritogenesis, axon guidance and synapse formation. The kynurenine pathway of tryptophan metabolism includes an agonist (quinolinic acid) and an antagonist (kynurenic acid) at these receptors. Rats were treated in late gestation with 3,4-dimethoxy-N-[4-(3-nitrophenyl)thiazol-2-yl]-benzene-sulphonamide (Ro61-8048), an inhibitor of kynurenine-3-monoxygenase which diverts kynurenine metabolism to kynurenic acid. Within 5 h of drug administration, there was a significant decrease in GluN2A expression and increased GluN2B in the embryo brains, with changes in sonic hedgehog at 24 h. When injected dams were allowed to litter normally, the brains of offspring were removed at postnatal day 21 (P21). Recordings of hippocampal field excitatory synaptic potentials (fEPSPs) showed that prenatal exposure to Ro61-8048 increased neuronal excitability and paired-pulse facilitation. Long-term potentiation was also increased, with no change in long-term depression. At this time, levels of GluN2A, GluN2B and postsynaptic density protein PSD-95 were all increased. Among several neurodevelopmental proteins, the expression of sonic hedgehog was increased, but DISC1 and dependence receptors were unaffected, while raised levels of doublecortin and Proliferating Cell Nuclear Antigen (PCNA) suggested increased neurogenesis. The results reveal that inhibiting the kynurenine pathway in utero leads to molecular and functional synaptic changes in the embryos and offspring, indicating that the pathway is active during gestation and plays a significant role in the normal early development of the embryonic and neonatal nervous system

    Isolation, characterization, and application of nanocellulose from oil palm empty fruit bunch fiber as nanocomposites

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    Nanocomposites, consisting of a polymeric matrix and nanosized elements as reinforcement, have attracted significant scientific attention because of their high mechanical performance. A large variety of nanocomposites have been prepared using bio-based materials as a matrix and nanoreinforcement, so that it can reduce the dependence on nondegradable products and move to a sustainable materials basis. The objective of this study was to isolate nanocellulose from empty fruit bunch (EFB) fiber and their reinforcing effect on polyvinyl alcohol (PVA)/starch blend films. A series of PVA/starch films with different content of nanocellulose were prepared by solution casting method. Nanocellulose fiber with diameters ranging from 4 to 15 nm has been successfully prepared. On the other hand, PVA/starch films reinforced with nanocellulose fiber possess significantly improved properties compared to unreinforced film. From the results, PVA/starch films with the addition of 5% (v/v) of nanocellulose exhibited best combination of properties. This nanocomposite was found to have tensile strength at about 5.694 MPa and elongation at break was 481.85%. In addition to good mechanical properties, this nanocomposite has good water resistance and biodegradabilit

    Bioindication of megalopolis park ecosystems under aerotechnogenic loading

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    This study focuses on the influence of motor transport on various indicators of park ecosystems and Taraxacum officinale Web., as well as on their applicability to the bioindication of the urban environments in the largest megalopolis of Ukraine, namely, Kyiv. Our investigations were carried out in 14 park ecosystems exposed to different levels of aerotechnogenic loading: low pollution level in Pushcha-Vodytsya (park) and outskirts, average pollution level alongseven roads with medium traffic and high pollution level along eight highways. Pollen indication, integration and statistical methods were used to identify the most sensitive indicators of the impact of air pollutants. The aim is to assess the impact of vehicle emissions on the state of park ecosystems in the metropolis using bioindication and GIS technologies. The effects of air pollution on green infrastructure at the level of cells, organisms, groups and ecosystems in time and space are revealed. Under the influence of aerotechnogenic pollution, there is a deterioration of trees, their drying, defoliation of crowns and deterioration of integral indicators of park ecosystems. Using QGIS (Free open source geographic information system, version 3.12.3 „București”, May 15, 2020), we have created maps for the spread of air pollutants. The highest levels of air pollution and damage to parks were concentrated in the central part of the city with dense buildings and near heavy traffic roads. The average daily maximum allowable concentration (MAC) of phytotoxicants exceeded 1.5 MACa.d. and depended on the terrain and directions of the prevailing winds. We registered degradation of the megalopolis ecological state by 19.3% for 7 years

    In vitro inhibitory effect of Rubraxanthone isolated from Garcinia psrvifolia on platelet- Activating factor receptor binding

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    Rubraxanthone and isocowanol isolated from Garcinia parvifolia Miq. were investigated for their inhibitory effects on platelet-activating factor (PAF) binding to rabbit platelets using 3H-PAF as a ligand. Rubraxanthone showed a strong inhibition with IC 50 value of 18.2 microM. The IC 50 values of macluraxanthone, 6-deoxyjacareubin, 2-(3-methylbut-2-enyl)-1,3,5-trihydroxyxanthone, 2-(3-methylbut-2-enyl)-1,3,5,6-tetrahydroxyxanthone and 1,3,5-trihydroxy-6,6'-dimethylpyrano(2',3':6,7)-4-(1,1-dimethylprop-2-enyl)-xanthone were also determined for comparison. In the course of our study on structure-activity relationship of xanthones, the results revealed that a geranyl group substituted at C-8 was beneficial to the binding while a hydroxylated prenyl group at C-4 resulted in a significant loss in binding to the PAF receptor

    Prenatal activation of Toll-like receptors-3 by administration of the viral mimetic poly(I:C) changes synaptic proteins, N-methyl-D-aspartate receptors and neurogenesis markers in offspring

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    Background - There is mounting evidence for a neurodevelopmental basis for disorders such as autism and schizophrenia, in which prenatal or early postnatal events may influence brain development and predispose the young to develop these and related disorders. We have now investigated the effect of a prenatal immune challenge on brain development in the offspring. Pregnant rats were treated with the double-stranded RNA polyinosinic:polycytidylic acid (poly(I:C); 10 mg/kg) which mimics immune activation occurring after activation of Toll-like receptors-3 (TLR3) by viral infection. Injections were made in late gestation (embryonic days E14, E16 and E18), after which parturition proceeded naturally and the young were allowed to develop up to the time of weaning at postnatal day 21 (P21). The brains of these animals were then removed to assess the expression of 13 different neurodevelopmental molecules by immunoblotting. Results - Measurement of cytokine levels in the maternal blood 5 hours after an injection of poly(I:C) showed significantly increased levels of monocyte chemoattractant protein-1 (MCP-1), confirming immune activation. In the P21 offspring, significant changes were detected in the expression of GluN1 subunits of NMDA receptors, with no difference in GluN2A or GluN2B subunits or the postsynaptic density protein PSD-95 and no change in the levels of the related small GTPases RhoA or RhoB, or the NMDA receptor modulator EphA4. Among presynaptic molecules, a significant increase in Vesicle Associated Membrane Protein-1 (VAMP-1; synaptobrevin) was seen, with no change in synaptophysin or synaptotagmin. Proliferating Cell Nuclear Antigen (PCNA), as well as the neurogenesis marker doublecortin were unchanged, although Sox-2 levels were increased, suggesting possible changes in the rate of new cell differentiation. Conclusions - The results reveal the induction by prenatal poly(I:C) of selective molecular changes in the brains of P21 offspring, affecting primarily molecules associated with neuronal development and synaptic transmission. These changes may contribute to the behavioural abnormalities that have been reported in adult animals after exposure to poly(I:C) and which resemble symptoms seen in schizophrenia and related disorders

    Prenatal activation of Toll-like receptors-3 by administration of the viral mimetic poly(I:C) changes synaptic proteins, N-methyl-D-aspartate receptors and neurogenesis markers in offspring

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    Abstract Background There is mounting evidence for a neurodevelopmental basis for disorders such as autism and schizophrenia, in which prenatal or early postnatal events may influence brain development and predispose the young to develop these and related disorders. We have now investigated the effect of a prenatal immune challenge on brain development in the offspring. Pregnant rats were treated with the double-stranded RNA polyinosinic:polycytidylic acid (poly(I:C); 10 mg/kg) which mimics immune activation occurring after activation of Toll-like receptors-3 (TLR3) by viral infection. Injections were made in late gestation (embryonic days E14, E16 and E18), after which parturition proceeded naturally and the young were allowed to develop up to the time of weaning at postnatal day 21 (P21). The brains of these animals were then removed to assess the expression of 13 different neurodevelopmental molecules by immunoblotting. Results Measurement of cytokine levels in the maternal blood 5 hours after an injection of poly(I:C) showed significantly increased levels of monocyte chemoattractant protein-1 (MCP-1), confirming immune activation. In the P21 offspring, significant changes were detected in the expression of GluN1 subunits of NMDA receptors, with no difference in GluN2A or GluN2B subunits or the postsynaptic density protein PSD-95 and no change in the levels of the related small GTPases RhoA or RhoB, or the NMDA receptor modulator EphA4. Among presynaptic molecules, a significant increase in Vesicle Associated Membrane Protein-1 (VAMP-1; synaptobrevin) was seen, with no change in synaptophysin or synaptotagmin. Proliferating Cell Nuclear Antigen (PCNA), as well as the neurogenesis marker doublecortin were unchanged, although Sox-2 levels were increased, suggesting possible changes in the rate of new cell differentiation. Conclusions The results reveal the induction by prenatal poly(I:C) of selective molecular changes in the brains of P21 offspring, affecting primarily molecules associated with neuronal development and synaptic transmission. These changes may contribute to the behavioural abnormalities that have been reported in adult animals after exposure to poly(I:C) and which resemble symptoms seen in schizophrenia and related disorders.</p

    Multimodalities Element in the Cartoon Work Through Linguistic Modes and Visual Modes

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    In cartoons, meanings and messages are generated either through two semiotic modes that are verbal and visual or solely through visual modes. Interaction between language and cartoon images is often regarded as a straightforward and easy-to-process way to convey a message. This study aims to show that the meaning and cartoon messages are not always easy to understand, therefore readers should observe the language and visual information of each cartoon. This study is aimed at identifying the linguistic modes and the visual modes in the cartoons to convey the meaning and the explicit message or implied message. For this purpose, two theories are adopted; Systemic Functional Linguistics Theory by Halliday (1994) to analyze linguistic modes and multimodal approach by Kress and Van Leeuwen (1996, 2006) to analyze visual modes or images in cartoons. The research data was obtained from Usik-Usik cartoon book (Cynical Collection of the World of Education). The findings indicate that language text is a linguistic modes that acts as an effective multimodal element and complement the visual modes in the cartoon work. Furthermore, the findings of the study also show that the role of linguistic modes is to provide the context in the cartoon work as additional information so that the reader can understand the messages to be communicated more clearly
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