172 research outputs found
ANALYTISCHE ANWENDUNG DER PYRIDIN-RHODANID-KOMPLEXE ZWEIWERTIGER METALLE NACH EINEM IR-SPEKTROSKOPISCHEN VERFAHREN : (ANALYSE VON KUPFER-NICKEL-MANGAN-LEGIERUNGEN)
ANALYTISCHE ANWENDUNG DER PYRIDIN-RHODANID-KOMPLEXE ZWEIWERTIGER METALLE NACH EINEM IR-SPEKTROSKOPISCHEN VERFAHREN (ANALYSE VON KUPFER-ZINK-LEGIERUNGEN)
UNTERSUCHUNG DER BEI HOCHTEMPERATUR-FESTKĂRPERREAKTIONEN VON KALIUMKARBONAT UND VERSCHIEDENEN OXIDEN ENTSTEHENDEN PRODUKTE MITTELS INFRAROT-SPEKTROSKOPIE
The Role of the Substantia Nigra Pars Compacta in Regulating Sleep Patterns in Rats
Background. As of late, dopaminergic neurotransmission has been recognized to be involved in the generation of sleep disturbances. Increasing evidence shows that sleep disturbances in Parkinson's disease (PD) patients are mostly related to the disease itself, rather than being a secondary phenomenon. Evidence contained in the literature lends support to the hypothesis that the dopaminergic nigrostriatal pathway is closely involved in the regulation of sleep patterns. Methodology/Principal Findings. To test this hypothesis we examined the electrophysiological activity along the sleep-wake cycle of rats submitted to a surgically induced lesion of the SNpc by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). We demonstrated that a 50% lesion of the substantia nigra pars compacta (SNpc) suffices to produce disruptions of several parameters in the sleep-wake pattern of rats. A robust and constant decrease in the latency to the onset of slow wave sleep (SWS) was detected throughout the five days of recording in both light [F((22.16)) = 72.46, p<0.0001] and dark [F((22.16)) = 75.0, p<0.0001] periods. Also found was a pronounced increase in the percentage of sleep efficiency during the first four days of recording [F((21.15)) = 21.48, p<0.0001], in comparison to the sham group. Additionally, the reduction in the SNpc dopaminergic neurons provoked an ablation in the percentage of rapid eye movement sleep (REM) during three days of the sleep-wake recording period with a strong correlation (r = 0.91; p<0.0001) between the number of dopaminergic neurons lost and the percentage decrease of REM sleep on the first day of recording. On day 4, the percentage of REM sleep during the light and dark periods was increased, [F((22.16)) = 2.46, p<0.0007], a phenomenon consistent with REM rebound. Conclusions/Significance. We propose that dopaminergic neurons present in the SNpc possess a fundamental function in the regulation of sleep processes, particularly in promoting REM sleep.AFIPCoordenação de Aperfeiçoamento de Pessoal de NĂvel Superior (CAPES)Fundação de Amparo Ă Pesquisa do Estado de SĂŁo Paulo (FAPESP)Universidade Federal de SĂŁo Paulo, Dept Psicobiol, SĂŁo Paulo, BrazilUniv Fed Parana, Dept Farmacol, BR-80060000 Curitiba, Parana, BrazilUniversidade Federal de SĂŁo Paulo, Dept Psicobiol, SĂŁo Paulo, BrazilFAPESP: 98/14.303-3Web of Scienc
Hypoxia Reduces Arylsulfatase B Activity and Silencing Arylsulfatase B Replicates and Mediates the Effects of Hypoxia
This report presents evidence of 1) a role for arylsulfatase B (ARSB; N-acetylgalactosamine-4-sulfatase) in mediating intracellular oxygen signaling; 2) replication between the effects of ARSB silencing and hypoxia on sulfated glycosaminoglycan content, cellular redox status, and expression of hypoxia-associated genes; and 3) a mechanism whereby changes in chondroitin-4-sulfation that follow either hypoxia or ARSB silencing can induce transcriptional changes through galectin-3. ARSB removes 4-sulfate groups from the non-reducing end of chondroitin-4-sulfate and dermatan sulfate and is required for their degradation. For activity, ARSB requires modification of a critical cysteine residue by the formylglycine generating enzyme and by molecular oxygen. When primary human bronchial and human colonic epithelial cells were exposed to 10% O2Ă1 h, ARSB activity declined by âŒ41% and âŒ30% from baseline, as nuclear hypoxia inducible factor (HIF)-1α increased by âŒ53% and âŒ37%. When ARSB was silenced, nuclear HIF-1α increased by âŒ81% and âŒ61% from baseline, and mRNA expression increased to 3.73 (±0.34) times baseline. Inversely, ARSB overexpression reduced nuclear HIF-1α by âŒ37% and âŒ54% from baseline in the epithelial cells. Hypoxia, like ARSB silencing, significantly increased the total cellular sulfated glycosaminoglycans and chondroitin-4-sulfate (C4S) content. Both hypoxia and ARSB silencing had similar effects on the cellular redox status and on mRNA expression of hypoxia-associated genes. Transcriptional effects of both ARSB silencing and hypoxia may be mediated by reduction in galectin-3 binding to more highly sulfated C4S, since the galectin-3 that co-immunoprecipitated with C4S declined and the nuclear galectin-3 increased following ARSB knockdown and hypoxia
Cephalopod-omics: emerging fields and technologies in cephalopod biology
14 pages, 1 figure.-- This is an Open Access article distributed under the terms of the Creative Commons Attribution LicenseFew animal groups can claim the level of wonder that cephalopods instill in the minds of researchers and the general public. Much of cephalopod biology, however, remains unexplored: the largest invertebrate brain, difficult husbandry conditions, and complex (meta-)genomes, among many other things, have hindered progress in addressing key questions. However, recent technological advancements in sequencing, imaging, and genetic manipulation have opened new avenues for exploring the biology of these extraordinary animals. The cephalopod molecular biology community is thus experiencing a large influx of researchers, emerging from different fields, accelerating the pace of research in this clade. In the first post-pandemic event at the Cephalopod International Advisory Council (CIAC) conference in April 2022, over 40 participants from all over the world met and discussed key challenges and perspectives for current cephalopod molecular biology and evolution. Our particular focus was on the fields of comparative and regulatory genomics, gene manipulation, single-cell transcriptomics, metagenomics, and microbial interactions. This article is a result of this joint effort, summarizing the latest insights from these emerging fields, their bottlenecks, and potential solutions. The article highlights the interdisciplinary nature of the cephalopod-omics community and provides an emphasis on continuous consolidation of efforts and collaboration in this rapidly evolving fieldPeer reviewe
Hochfrequenzmessungen der KapazitÀt von Ionenaustauschern und deren Chlormethylderivaten
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