Dopamine-induced ascorbate release from retinal neurons involves glutamate release, activation of AMPA/Kainate receptors and downstream signaling pathways

Ascorbate, the reduced form of Vitamin C, is one of the most abundant and important low-molecular weight antioxidants in living tissues. Most animals synthesize Vitamin C, but some primates, including humans, have lost this capacity due to disruption in L-gulono-gamma-lactone oxidase gene. Because of this incapacity, those animals must obtain Vitamin C from the diet. Ascorbate is highly concentrated in the central nervous system (CNS), including the retina, and plays essential roles in neuronal physiology. Ascorbate transport into cells is controlled by Sodium Vitamin C Co-Transporters (SVCTs). There are four SVCT isoforms and SVCT2 is the major isoform controlling ascorbate transport in the CNS. Regarding ascorbate release from retinal neurons, Glutamate, by activating its ionotropic receptors leads to ascorbate release via the reversion of SVCT2. Moreover, dopamine, via activation of D1 receptor/cyclic AMP/EPAC2 pathway, also induces ascorbate release via SVCT2 reversion. Because the dopaminergic and glutamatergic systems are interconnected in the CNS, we hypothesized that dopamine could regulate ascorbate release indirectly, via the glutamatergic system. Here we reveal that dopamine increases the release of D-Aspartate from retinal neurons in a way independent on calcium ions and dependent on excitatory amino acid transporters. In addition, dopamine-dependent SVCT2 reversion leading to ascorbate release occurs by activation of AMPA/Kainate receptors and downstream ERK/AKT pathways. Overall, our data reveal a dopamine-to-glutamate signaling that regulates the bioavailability of ascorbate in neuronal cells.This work was supported by grants from Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq), Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES), Fundação Carlos Chagas Filho de Amparo à Pesquisa do Estado do Rio de Janeiro (FAPERJ), and Pró-Reitoria de Pesquisa, Pós-Graduação e Inovação da Universidade Federal Fluminense (PROPPI/UFF). TGE, ID, and NAO were recipients of graduate student fellowships from CAPES. RPC is a research fellow from CNPq and FAPERJ. CCP and RS hold employment contracts financed by national funds through FCT – Fundação para a Ciência e a Tecnologia, I.P., in the context of the program-contract described in paragraphs 4, 5 and 6 of art. 23 of Law no. 57/2016, of August 29, as amended by Law no. 57/2017 of July 19

Seed grafting of hevea. I: Potential viability - Preliminary Results

Ensaios exploratórios conduzidos no Centro Nacional de Pesquisa da Seringueira- CNPSe (1976-77), usando extremidades apicais dos clones IAN 717, IAN 873 e Fx 3899, medindo 3-4 cm de comprimento, seccionadas em bisel duplo e enxertadas em sementes em fase de germinação (dois a cinco dias de germinadas), em secção vertical no eixo entre os dois pecíolos cotiledonários, mostraram ser possível a enxertia de plântulas de seringueira desde os primeiros estágios de germinação das sementes. Os melhores resultados foram obtidos quando foi permitido às duas gemas cotiledonárias brotarem e se desenvolverem, pois houve melhor pegamento dos enxertos e mais rápida formação do calo, sete dias após a enxertia. Aos 21 dias após a enxertia, deu-se a expansão foliar com início do primeiro fluxo de lançamento. O segundo lançamento foliar apresentou tamanho superior ao primeiro, em todos os casos, mostrando ter havido perfeita união dos tecidos entre enxerto e porta-enxerto e consequente continuidade de crescimento do clone enxertado.Cleft grafting of rubber trees have been tried with some promising results when apical parts 3-4 cm long were used as scions grafted on to seeds with two-five days after emergence of epicotyl. Better results were obtained when the two lateral cotyledonary buds were left to sprout and grow untill a good callus union was formed between scion and rootstock. In this case, callus was evident after seven days of the graft operation. Scion started flushing withing 21 days. As a result of the exhaustion of seed reserves, due to growth of lateral shoots, these first flushes showed a stunted growth. The second flushes were longer and more vigorous than the first ones, and this is interpreted as the result of the improvement of the graft union and better root growth

Absence of ferromagnetic order in high quality bulk Co-doped ZnO samples

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Bulk Zn(1-x)Co(x)O samples were synthesized via standard solid-state reaction route with different Co molar concentrations up to 21%. A detailed microstructural analysis was carried out to investigate alternative sources of ferromagnetism, such as secondary phases and nanocrystals embedded in the bulk material. Conjugating different techniques we confirmed the Zn replacement by Co ions in the wurtzite ZnO structure, which retains, however, a high crystalline quality. No segregated secondary phases neither Co-rich nanocrystals were detected. Superconducting quantum interference device magnetometry demonstrates a paramagnetic Curie-Weiss behavior with antiferromagnetic interactions. We discuss the observed room temperature paramagnetism of our samples considering the current models for the magnetic properties of diluted magnetic semiconductors. (C) 2010 American Institute of Physics. [doi: 10.1063/1.3459885]1083FAPEMIGConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)FAPEMIG_BrasilCNPq_BrasilFAPESP_Brasi

Efeito de diferentes formas de cultivo na ação do óxido nítrico na maturação e na integridade da membrana plasmática de complexos cumulus-oócito em bovinos

The aim of the present study was to evaluate the influence of different forms of in vitro culture on the nitric oxide action in maturation and membrane integrity on bovine cumulus-oocyte complex. No significant effect was observed between different forms of culture (mineral oil vs plate; P &gt; 0.05), as much for membrane integrity as for expansion of the CC. However, it was observed that oocytes of the groups control and 10-3 M of SNP, cultivated in plate, had presented greater percentage of cell with maintenance of membrane integrity than same treatments cultivated in drop. The addition of 10-3 M of SNP showed an inhibitory effect on the expansion and membrane integrity of CC and oocytes in both, culture in drops under oil and plate (P < 0.05). The culture form did not intervene with the extrusion of the first polar corpuscle and the addition of 10-3 M of SNP inhibited this extrusion in the both systems (P < 0.05). There was a dose-response effect on the concentration of NO in the maturation medium in both types of cultivation (P < 0,05), and this was higher in the culture medium under oil, except when added 10-3 M of SNP, treatment in which there was no difference in the types of cultivation employed. (PO objetivo do presente estudo foi avaliar se diferentes formas de cultivo interferem no efeito do óxido nítrico (NO) sobre a maturação e a integridade da membrana plasmática do complexo cumulus-oócito de bovinos. Para tanto, realizou-se cultivo em gotas sob óleo mineral ou em placas de quatro poços com a adição de diferentes concentrações de nitroprussiato de sódio (SNP, doador de óxido nítrico). Não foi observada diferença (P &gt; 0,05) entre as formas de cultivo quando se avaliou a integridade de membrana plasmática e a expansão das células do cumulus (CC). Contudo, os oócitos dos grupos controle e os cultivados na presença de 10-3 M de SNP, ambos cultivados em placa, apresentaram maior porcentagem de membrana íntegra do que os mesmos tratamentos cultivados em óleo mineral (P &lt; 0,05). Observou-se que a adição de 10-3 M de SNP diminuiu o grau de expansão das CC e de integridade da membrana plasmática dos oócitos, tanto no cultivo em gota sob óleo quanto em placa, diferindo dos outros grupos (P &lt; 0,05). Semelhante à expansão, a forma de cultivo não interferiu na extrusão do primeiro corpúsculo polar, sendo que a adição de 10-3 M de SNP inibiu a extrusão em ambos os sistemas (P &lt; 0,05). Houve um efeito dose-resposta na concentração de NO no meio de maturação em ambos os tipos de cultivo (P &lt; 0,05), sendo que esta foi maior no meio de cultivo sob óleo, exceção feita quando se adicionou 10-3 M de SNP, tratamento no qual não houve diferença nos tipos de cultivo empregados. Estes dados mostram que o sistema de cultivo não interferiu na ação do NO na maturação in vitro de COC bovinos, mas interfere na integridade da membrana plasmática do oócito

High incidence of acquiring methicillin-resistant <i>Staphylococcus aureus</i> in Brazilian children with Atopic Dermatitis and associated risk factors

BACKGROUND: Methicillin-resistant Staphylococcus aureus (MRSA) colonization in Atopic Dermatitis (AD) patients can contribute to worsening their clinical condition. OBJECTIVE: A cohort study was carried out to determine the incidence of MRSA acquisition and its risk factors in AD children. METHODS: Patients with AD (2 months-14 years old) were followed up for about 1 year at a reference center for AD treatment in Rio de Janeiro, Brazil, from September 2011 to February 2014. Nasal swabs from patients and contacts were collected every 2 months. The SCORAD system assessed the severity of the AD. S. aureus isolates were evaluated to determine the methicillin resistance and the clonal lineages. RESULTS: Among 117 AD patients, 97 (82.9%) were already colonized with S. aureus and 26 (22.2%) had MRSA at the first evaluation. The incidence of MRSA acquisition in the cohort study was 27.47% (n = 25). The SCORAD assessments were: mild (46.15%), moderate (37.36%) or severe (16.48%). Risk factors were: colonized MRSA contacts (HR = 2.27; 95% CI: 1.16-7.54), use of cyclosporine (HR = 5.84; 95% CI: 1.70-19.98), moderate or severe AD (HR = 3.26; 95% CI: 1.13-9.37). Protective factors were: availability of running water (HR = 0.21; 95% CI: 0.049-0.96) and use of antihistamines (HR = 0.21; 95% IC: 0.64-0.75). MRSA isolates carried the SCCmec type IV and most of them were typed as USA800/ST5. CONCLUSIONS: The high incidence of MRSA acquisition found among AD patients and the risk factors associated show that an effective surveillance of MRSA colonization in these patients is needed

BRS 2022: híbrido duplo de milho.

bitstream/CNPMS-2010/22531/1/Com-174.pd

Adaptabilidade e estabilidade de híbridos de milho em 35 ambientes.

O objetivo deste trabalho foi avaliar a adaptabilidade e estabilidade de híbridos de milho em varias regiões do país