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21.
Absence of Tau triggers age‐dependent sciatic nerve morphofunctional deficits and motor impairment 下载免费PDF全文
Sofia Lopes André Lopes Vítor Pinto Marco R. Guimarães Vanessa Morais Sardinha Sara Duarte‐Silva Sara Pinheiro João Pizarro João Filipe Oliveira Nuno Sousa Hugo Leite‐Almeida Ioannis Sotiropoulos 《Aging cell》2016,15(2):208-216
Dementia is the cardinal feature of Alzheimer's disease (AD), yet the clinical symptoms of this disorder also include a marked loss of motor function. Tau abnormal hyperphosphorylation and malfunction are well‐established key events in AD neuropathology but the impact of the loss of normal Tau function in neuronal degeneration and subsequent behavioral deficits is still debated. While Tau reduction has been increasingly suggested as therapeutic strategy against neurodegeneration, particularly in AD, there is controversial evidence about whether loss of Tau progressively impacts on motor function arguing about damage of CNS motor components. Using a variety of motor‐related tests, we herein provide evidence of an age‐dependent motor impairment in Tau?/? animals that is accompanied by ultrastructural and functional impairments of the efferent fibers that convey motor‐related information. Specifically, we show that the sciatic nerve of old (17–22‐months) Tau?/? mice displays increased degenerating myelinated fibers and diminished conduction properties, as compared to age‐matched wild‐type (Tau+/+) littermates and younger (4–6 months) Tau?/? and Tau+/+ mice. In addition, the sciatic nerves of Tau?/? mice exhibit a progressive hypomyelination (assessed by g‐ratio) specifically affecting large‐diameter, motor‐related axons in old animals. These findings suggest that loss of Tau protein may progressively impact on peripheral motor system. 相似文献
22.
Nina Tonn Sara C. Novais Cátia S. E. Silva Hugo A. Morais João P. S. Correia 《Marine Biology Research》2016,12(9):948-957
Animal welfare during handling and transportation to aquaculture facilities or public aquaria is commonly estimated by addressing injury and mortality levels. Although these procedures have been optimized for different species, data on individual species’ cellular capabilities to tolerate stress are still scarce. In the present study, several biomarkers related with oxidative stress and energy metabolism were assessed in Holothuria forskali during animal acclimation, pre-transport, transport and quarantine. Combined analyses confirmed that sea cucumbers experienced high oxidative stress during transport, but had the capability to deal with it using a complex of cellular defence mechanisms, which enabled recovery from oxidative stress without permanent damage. Through a better understanding of individual species and the development of optimal parameters, this approach has the potential to improve animal wellbeing during and after acclimation, transportation and recovery processes. 相似文献
23.
Sara Silva Eduardo M. Costa Bruno Horta Conceição Calhau Rui M. Morais 《Biofouling》2016,32(8):853-860
Phenolic acids are a particular group of small phenolic compounds which have exhibited some anti-biofilm activity, although the link between their activity and their intrinsic pH is not clear. Therefore, the present work examined the anti-biofilm activity (inhibition of biomass and metabolic activity) of phenolic acids in relation to the environmental pH, as well as other physico-chemical properties. The results indicate that, while Escherichia coli was not inhibited by the phenolic acids, both methicillin resistant Staphylococcus aureus and methicillin resistant Staphylococcus epidermidis were susceptible to the action of all phenolic acids, with the pH playing a relevant role in the activity: a neutral pH favored MRSE inhibition, while acidic conditions favored MRSA inhibition. Some links between molecular polarity and size were associated only with their potential as metabolic inhibitors, with the overall interactions hinting at a membrane-based mechanism for MRSA and a cytoplasmic effect for MRSE. 相似文献
24.
Jessica Tauany Andrade Geisa Fantini de Figueiredo Luisa Ferreira Cruz Sarah Eliza de Morais Carla Daiane Ferreira Souza Flávia Carmo Horta Pinto Jaqueline Maria Siqueira Ferreira Marcelo Gonzaga de Freitas Araújo 《Revista iberoamericana de micología》2019,36(4):192-199
BackgroundCandida albicans is the main agent that causes vulvovaginal candidiasis. Resistance among isolates to azole antifungal agents has been reported.AimsDue to the well-known antifungal potential of curcumin, the purpose of this work was to evaluate the in vitro anticandidal activity of curcumin and its effect in the treatment of experimental vulvovaginal candidiasis.MethodsThe anticandidal activity of curcumin was investigated against eight Candida strains by the broth microdilution assay, and its mechanism of action was evaluated by testing the binding to ergosterol. Then, the effect of curcumin in the treatment of vulvovaginal candidiasis was evaluated in an immunosuppressed, estrogen treated rat model.ResultsCurcumin showed minimum inhibitory concentration values of 125–1000 μg/ml, and the best result was observed against Candida glabrata. The compound was shown to be able to bind to the ergosterol present in the membrane, event that may be the mechanism of action. In addition, in the in vivo model of vulvovaginal candidiasis with C. albicans, treatments reduced the vaginal fungal burden in infected rats after seven days of treatment with different doses.ConclusionsCurcumin could be considered a promising effective antifungal agent in the treatment of vulvovaginal candidiasis. 相似文献
25.
Francieli Chassot Tarcieli Pozzebon Venturini Fernanda Baldissera Piasentin Janio Morais Santurio Terezinha Inez Estivalet Svidzinski Sydney Hartz Alves 《Revista iberoamericana de micología》2019,36(1):44-47
Background
Candida parapsilosis may acquire resistance to echinocandins, a fact that prompts the search for new therapeutic options.Aims
The present study aimed to evaluate the in vitro activity of antifungal agents, alone and in combination, against four groups of C. parapsilosis strains: (1) echinocandin-susceptible (ES) clinical isolates (MIC ≤ 2 μg/ml), (2) anidulafungin-resistant strains (MIC ≥ 8 μg/ml), (3) caspofungin-resistant strains (MIC ≥ 8 μg/ml), and (4) micafungin-resistant strains (MIC ≥ 8 μg/ml).Methods
Antifungal interactions were evaluated by a checkerboard micro-dilution method. The determination of the MIC to each drug for every isolate according to the Clinical and Laboratory Standards Institute documents M27 (2017) and M60 (2017) was also done.Results
The echinocandins-resistant (ER) strains showed higher MICs to the tested antifungals than the ES strains, except for amphotericin B, for which the ER groups remained susceptible.Conclusions
Most combinations showed indifferent interactions. The use of monotherapy still seems to be the best option. As resistance to echinocandins is an emergent phenomenon, further studies are required to provide clearer information on the susceptibility differences between strains to these antifungal agents. 相似文献26.
27.
Wanderley-Nogueira AC Soares-Cavalcanti NM Morais DA Belarmino LC Barbosa-Silva A Benko-Iseppon AM 《Genetics and molecular research : GMR》2007,6(4):866-889
Resistance genes (R-genes) are responsible for the first interaction of the plant with pathogens being responsible for the activation (or not) of the defense response. Despite their importance and abundance, no tools for their automatic annotation are available yet. The present study analyzed R-genes in the sugarcane expressed sequence tags database which includes 26 libraries of different tissues and development stages comprising 237,954 expressed sequence tags. A new annotation routine was used in order to avoid redundancies and overestimation of R-gene number, common mistakes in previous evaluations. After in silico screening, 280 R-genes were identified, with 196 bearing the complete domains expected. Regarding the alignments, most of the sugarcane's clusters yielded best matches with proteins from Oryza sativa, probably due to the prevalence of sequences of this monocot in data banks. All R-gene classes were found except the subclass LRR-NBS-TIR (leucine-rich repeats, nucleotide-binding site, including Toll interleukin-1 receptors), with prevalence of the kinase (Pto-like) class. R-genes were expressed in all libraries, but flowers, transition root to shoot, and roots were the most representative, suggesting that in sugarcane the expression of R-genes in non-induced conditions prevails in these tissues. In leaves, only low level of expression was found for some gene classes, while others were completely absent. A high allelic diversity was found in all classes of R-genes, sometimes showing best alignments with dicotyledons, despite the great number of genes from rice, maize and other grasses deposited in data banks. The results and future possibilities regarding R-genes in sugarcane research and breeding are further discussed. 相似文献
28.
João Paulo Araújo Fernandes de Queiroz João Batista Freire de Souza Jr Vanessa Raquel de Morais Oliveira Thibério de Souza Castelo Maiko Roberto Tavares Dantas Leonardo Lelis de Macedo Costa 《Biological Rhythm Research》2019,50(2):232-244
This study aimed to evaluate the diurnal variation of the sensible heat transfer in red-rumped agoutis (Dasyprocta leporina) bred in captivity in a semi-arid environment. In addition, we seek to identify thermal windows by infrared thermography during the daytime period (07:00, 09:00, 11:00, 14:00, and 16:00). The body surface temperature was higher in the pinna (36.84 ± 0.11 °C), followed by the hind limbs (36.55 ± 0.11 °C). These body regions were primarily responsible for heat loss by radiation (which was 10.13 ± 1.17 W m?2 and 11.19 ± 1.17 W m?2, respectively), and acted like biological thermal windows. Heat transfer by convection was more intense in the body trunk and hind limbs at all times of the day. Thus, sensible heat transfer is important for maintaining homeothermy in red-rumped agouti in hot environments. In conclusion, these rodents use specialized body regions (pinna and hind limbs) for heat transfer. 相似文献
29.
Letícia Helena dos Santos Marques Luciana Inácia Gomes Iara Caixeta Marques da Rocha Thaís Almeida Marques da Silva Edward Oliveira Maria Helena Franco Morais Ana Rabello Mariangela Carneiro 《PLoS neglected tropical diseases》2012,6(12)
Background
An important issue associated with the control of visceral leishmaniasis is the need to identify and understand the relevance of asymptomatic infection caused by Leishmania infantum. The aim of this study was to follow the course of asymptomatic L. infantum infection in children in an area of Brazil where it is endemic. The children were assessed twice during a 12-month period.Methodology
In this population study, 1875 children, ranging from 6 months to 7 years of age, were assessed. Blood samples were collected on filter papers via finger prick and tested by ELISA (L. infantum soluble antigen and rk39). Seropositives samples (n = 317) and a number of seronegatives samples (n = 242) were subjected to qPCR. After 12 months, blood samples were collected from a subgroup of 199 children and tested for Leishmania spp. to follow the course of infection.Principal Findings
At baseline qPCR testing identified 82 positive samples. The prevalence rate, as estimated for 1875 children based on the qPCR results, was 13.9%. The qPCR testing of whole blood samples collected from a cohort of children after 12 months (n = 199) yielded the following results: of the 44 (22.1%) children with positive qPCR results at baseline, only 10 (5.0%) remained positive, and 34 (17.1%) became negative; and of the 155 (77.9%) children with negative qPCR results, 131 (65.8%) remained negative, and 24 (12.1%) became positive at the follow-up measurement. The samples with positive findings at baseline (n = 82) had a mean of 56.5 parasites/mL of blood; and at follow-up the mean positive result was 7.8 parasites/mL.Conclusions
The peripheral blood of asymptomatic children had a low and fluctuating quantity of Leishmania DNA and a significant decrease in parasitemia at 1-year follow-up. Quantitative PCR enables adequate monitoring of Leishmania infection. 相似文献30.
Cserháti T Forgács E Morais H Mota T 《Journal of biochemical and biophysical methods》2000,45(2):221-229
Silica gel, aluminium oxide, diatomaceous earth, polyamide, cyano, diol and amino plates have been tested for their capacity to separate the color pigments of six chili powders of different origin by both adsorption and reversed-phase thin-layer chromatography. The plates were evaluated at 340 and 440 nm wavelengths. Best separation of color pigments was obtained on impregnated diatomaceous earth layer using acetone-water 17:3 v/v eluent. It was found that the pigment composition of chili powders showed marked differences. Principal component analysis employed for the classification of the chili powders according to their pigment composition indicated that these differences can be used for the determination of the similarity or dissimilarity of the chili powders. 相似文献