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1.
Nutr Neurosci ; 27(3): 271-288, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36947578

RESUMO

OBJECTIVES: In this study mice were fed a high-fat diet for 12 weeks to establish diet-induced obesity and syringic acid (SA) was assessed for anti-obese, neuroprotective, and neurogenesis. METHOD: Animals were given HFD for 12 weeks to measure metabolic characteristics and then put through the Barns-maze and T-maze tests to measure memory. Additionally, the physiology of the blood-brain barrier, oxidative stress parameters, the expression of inflammatory genes, neurogenesis, and histopathology was evaluated in the brain. RESULT: DIO raised body weight, BMI, and other metabolic parameters after 12 weeks of overfeeding. A reduced spontaneous alternation in behavior (working memory, reference memory, and total time to complete a task), decreased enzymatic and non-enzymatic antioxidants, oxidative biomarkers, increased neurogenesis, and impaired blood-brain barrier were all seen in DIO mice. SA (50 mg/kg) treatment of DIO mice (4 weeks after 8 weeks of HFD feeding) reduced diet-induced changes in lipid parameters associated with obesity, hepatological parameters, memory, blood-brain barrier, oxidative stress, neuroinflammation, and neurogenesis. SA also reduced the impact of malondialdehyde and enhanced the effects of antioxidants such as glutathione, superoxide dismutase (SOD), and total thiol (MDA). Syringic acid improved neurogenesis, cognition, and the blood-brain barrier while reducing neurodegeneration in the hippocampal area. DISCUSSION: According to the results of the study, syringic acid therapy prevented neurodegeneration, oxidative stress, DIO, and memory loss. Syringic acid administration may be a useful treatment for obesity, memory loss, and neurogenesis, but more research and clinical testing is needed.


Assuntos
Ácido Gálico/análogos & derivados , Obesidade , Sobrepeso , Camundongos , Animais , Obesidade/etiologia , Obesidade/prevenção & controle , Obesidade/tratamento farmacológico , Encéfalo/metabolismo , Antioxidantes/farmacologia , Dieta Hiperlipídica/efeitos adversos , Estresse Oxidativo , Transtornos da Memória , Neurogênese/fisiologia
2.
World J Microbiol Biotechnol ; 40(6): 168, 2024 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-38630156

RESUMO

Obesity is a growing epidemic worldwide. Several pharmacologic drugs are being used to treat obesity but these medicines exhibit side effects. To find out the alternatives of these drugs, we aimed to assess the probiotic properties and anti-obesity potentiality of a lactic acid bacterium E2_MCCKT, isolated from a traditional fermented rice beverage, haria. Based on the 16S rRNA sequencing, the bacterium was identified as Lactiplantibacillus plantarum E2_MCCKT. The bacterium exhibited in vitro probiotic activity in terms of high survivability in an acidic environment and 2% bile salt, moderate auto-aggregation, and hydrophobicity. Later, E2_MCCKT was applied to obese mice to prove its anti-obesity potentiality. Adult male mice (15.39 ± 0.19 g) were randomly divided into three groups (n = 5) according to the type of diet: normal diet (ND), high-fat diet (HFD), and HFD supplemented with E2_MCCKT (HFT). After four weeks of bacterial treatment on the obese mice, a significant reduction of body weight, triglyceride, and cholesterol levels, whereas, improvements in serum glucose levels were observed. The bacterial therapy led to mRNA up-regulation of lipolytic transcription factors such as peroxisome proliferator-activated receptor-α which may increase the expression of fatty acid oxidation-related genes such as acyl-CoA oxidase and carnitine palmitoyl-transferase-1. Concomitantly, both adipocytogenesis and fatty acid synthesis were arrested as reflected by the down-regulation of sterol-regulatory element-binding protein-1c, acetyl-CoA carboxylase, and fatty acid synthase genes. In protein expression study, E2_MCCKT significantly increased IL-10 expression while decreasing pro-inflammatory cytokine (IL-1Ra and TNF-α) expression. In conclusion, the probiotic Lp. plantarum E2_MCCKT might have significant anti-obesity effects on mice.


Assuntos
Dieta Hiperlipídica , Obesidade , Masculino , Animais , Camundongos , Dieta Hiperlipídica/efeitos adversos , Camundongos Obesos , RNA Ribossômico 16S/genética , Ácidos Graxos
3.
J Appl Biomed ; 22(1): 49-58, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38505970

RESUMO

We have extracted and characterized Phasa fish (Setipinna phasa) oil for the first time to evaluate the anti-obesity and related anti-inflammatory effects on obese mice. Inbred male albino BALB/c mice were segregated into three categories: control (C), Obese control group (OC), and Phasa fish oil treated group (TX). To establish the potentiality of Setipinna phasa oil for its anti-obesity and anti-inflammatory properties, it was extracted and characterized using GC-MS method. To evaluate the anti-obesity effect, different parameters were considered, such as body weight, lipid composition, obesity, and obesity associated inflammation. The physicochemical characteristics of Phasa fish oil revealed that the oil quality was good because acid value, peroxide value, p-anisidine value, Totox value, refractive index, and saponification value were within the standard value range. The GC-MS study explored the presence of fatty acids beneficial to health such as Hexadec-9-enoic acid; Octadec-11-enoic acid; EPA, DHA, Methyl Linolenate, etc. The application of Setipinna phasa oil on the treated mice group acutely lowered body weight and serum lipid profile compared to the obese group. In connection with this, leptin, FAS, and pro-inflammatory cytokines TNF-α genes expression were downregulated in the treated group compared to the obese group. The Phasa oil treated group had an elevated expression of PPAR-α, adiponectin, LPL gene, and anti-inflammatory markers IL-10 and IL-1Ra compared to the obese group. This study suggests that Phasa fish oil, enriched with essential fatty acid, might be used as an anti-obesity and anti-inflammatory supplement.


Assuntos
Dieta Hiperlipídica , Obesidade , Masculino , Camundongos , Animais , Dieta Hiperlipídica/efeitos adversos , Camundongos Endogâmicos BALB C , Obesidade/tratamento farmacológico , Obesidade/metabolismo , Óleos de Peixe/farmacologia , Óleos de Peixe/uso terapêutico , Peso Corporal , Inflamação/tratamento farmacológico , Anti-Inflamatórios/farmacologia , Anti-Inflamatórios/uso terapêutico
4.
Int Microbiol ; 2023 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-38044417

RESUMO

Vibrio harveyi causes luminous vibriosis diseases in shrimp, which lead to shrimp mortalities. Considering the emergence of antibiotic-resistant bacteria, a Vibrio-infecting bacteriophage, VPMCC14, was characterized, and its lysis ability was evaluated on a laboratory scale. VPMCC14 was shown to infect V. harveyi S5A and V. harveyi ATCC 14126. VPMCC14 also exhibited a latent period of 30 min, with a burst size of 38 PFU/cell on its propagation strain. The bacteriophage was stable at a wide range of pHs (3-9), temperatures (0-45°C), and salinities (up to 40 ppt). VPMCC14 exhibited strict virulence properties as the bacteriophage entirely lysed V. harveyi S5A in liquid culture inhibition after 5 h and 4 h at very low MOIs such as MOI 0.1 and MOI 1, respectively. VPMCC14 could control V. harveyi infection in aquariums at MOI 1 and decrease the mortality of Penaeus monodon challenged by V. harveyi. VPMCC14 genome was 134,472 bp long with a 34.5 G+C% content, and 240 open reading frames. A unique characteristic of VPMCC14 was the presence of the HicB family antitoxin-coding open reading frame. Comparative genomic analyses suggested that VPMCC14 could be a representative of a new genus in the Caudoviricetes class. This novel bacteriophage, VPMCC14, could be applied as a biocontrol agent for controlling V. harveyi infection.

5.
J Chem Phys ; 159(22)2023 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-38078523

RESUMO

Coarse-grained (CG) molecular dynamics can be a powerful method for probing complex processes. However, most CG force fields use pairwise nonbonded interaction potentials sets, which can limit their ability to capture complex multi-body phenomena such as the hydrophobic effect. As the hydrophobic effect primarily manifests itself due to the nonpolar solute affecting the nearby hydrogen bonding network in water, capturing such effects using a simple one CG site or "bead" water model is a challenge. In this work, we systematically test the ability of CG one site water models for capturing critical features of the solvent environment around a hydrophobe as well as the potential of mean force (PMF) of neopentane association. We study two bottom-up models: a simple pairwise (SP) force-matched water model constructed using the multiscale coarse-graining method and the Bottom-Up Many-Body Projected Water (BUMPer) model, which has implicit three-body correlations. We also test the top-down monatomic (mW) and the Machine Learned mW (ML-mW) water models. The mW models perform well in capturing structural correlations but not the energetics of the PMF. BUMPer outperforms SP in capturing structural correlations and also gives an accurate PMF in contrast to the two mW models. Our study highlights the importance of including three-body interactions in CG water models, either explicitly or implicitly, while in general highlighting the applicability of bottom-up CG water models for studying hydrophobic effects in a quantitative fashion. This assertion comes with a caveat, however, regarding the accuracy of the enthalpy-entropy decomposition of the PMF of hydrophobe association.

6.
J Plant Res ; 136(2): 265-276, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36680680

RESUMO

Plants' ability to sense and respond to gravity is a unique and fundamental process. When a plant organ is tilted, it adjusts its growth orientation relative to gravity direction, which is achieved by a curvature of the organ. In higher, multicellular plants, it is thought that the relative directional change of gravity is detected by starch-filled organelles that occur inside specialized cells called statocytes, and this is followed by signal conversion from physical information to physiological information within the statocytes. The classic starch statolith hypothesis, i.e., the starch accumulating amyloplasts movement along the gravity vector within gravity-sensing cells (statocytes) is the probable trigger of subsequent intracellular signaling, is widely accepted. Acharya Jagadish Chandra Bose through his pioneering research had investigated whether the fundamental reaction of geocurvature is contractile or expansive and whether the geo-sensing cells are diffusedly distributed in the organ or are present in the form of a definite layer. In this backdrop, a microscopy based experimental study was undertaken to understand the distribution pattern of the gravisensing layer, along the length (node-node) of the model plant Alternanthera philoxeroides and to study the microrheological property of the mobile starch-filled statocytes following inclination-induced graviception in the stem of the model plant. The study indicated a prominent difference in the pattern of distribution of the gravisensing layer along the length of the model plant. The study also indicated that upon changing the orientation of the plant from vertical position to horizontal position there was a characteristic change in orientation of the mobile starch granules within the statocytes. In the present study for the analysis of the microscopic images of the stem tissue cross sections, a specialized and modified microscopic illumination setup was developed in the laboratory in order to enhance the resolution and contrast of the starch granules.


Assuntos
Microscopia , Amido , Sensação Gravitacional/fisiologia , Gravitação , Plastídeos/ultraestrutura , Gravitropismo/fisiologia
7.
Phytother Res ; 37(7): 3097-3120, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37246823

RESUMO

Phytoestrogens are plant secondary metabolite that is structurally and functionally similar to mammalian estrogens, which have been shown to have various health benefits in humans. Isoflavones, coumestans, and lignans are the three major bioactive classes of phytoestrogens. It has a complicated mechanism of action involving an interaction with the nuclear estrogen receptor isoforms ERα and ERß, with estrogen agonist and estrogen antagonist effects. Depending on their concentration and bioavailability in various plant sources, phytoestrogens can act as estrogen agonist or antagonists. Menopausal vasomotor symptoms, breast cancer, cardiovascular disease, prostate cancer, menopausal symptoms, and osteoporosis/bone health have all been studied using phytoestrogens as an additional standard hormone supplemental remedy. The botanical sources, techniques of identification, classification, side effects, clinical implications, pharmacological and therapeutic effects of their proposed mode of action, safety issues, and future directions for phytoestrogens have all been highlighted in this review.


Assuntos
Neoplasias da Mama , Isoflavonas , Neoplasias da Próstata , Animais , Masculino , Humanos , Fitoestrógenos/farmacologia , Fitoestrógenos/uso terapêutico , Estrogênios/uso terapêutico , Receptores de Estrogênio/metabolismo , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Próstata/tratamento farmacológico , Isoflavonas/farmacologia , Isoflavonas/uso terapêutico , Mamíferos/metabolismo
8.
Behav Brain Sci ; 46: e388, 2023 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-38054301

RESUMO

Psychologically faithful deep neural networks (DNNs) could be constructed by training with psychophysics data. Moreover, conventional DNNs are mostly monocular vision based, whereas the human brain relies mainly on binocular vision. DNNs developed as smaller vision agent networks associated with fundamental and less intelligent visual activities, can be combined to simulate more intelligent visual activities done by the biological brain.


Assuntos
Redes Neurais de Computação , Visão Monocular , Humanos , Encéfalo , Inteligência , Psicofísica
9.
Biol Cybern ; 116(1): 5-21, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34635954

RESUMO

A varying contrastive context filter (VCCF)-based model of brightness perception has been proposed. It is motivated first by a recently proposed difference of difference-of-Gaussian (DDOG) filter. Alongside, it is also inspired from the fact that the nature evolves various discrete systems and mechanisms to carry out many of its complex tasks. A weight factor, used for the linear combination of two filters representing the magnocellular and parvocellular channels in the central visual pathway, has been defined and termed as the factor of contrastive context (FOCC) in the present model. This is a binary variable that lends a property of discretization to the DDOG filter. By analyzing important brightness contrast as well as brightness assimilation illusions, we arrive at the minimal set of values (only two) for FOCC, using which one is able to successfully predict the direction of brightness shift in both situations of brightness contrast, claimed and categorized here as low contrastive context, and those of brightness assimilation, claimed and categorized here as high contrastive context perception, depending upon whether the initial M-channel-filtered stimulus is above or below a threshold of the contrastive context. As distinct from Michelson/Weber/RMS contrast, high or low, the contrastive context claimed is dependent on the edge information in the stimulus determined by the Laplacian operator, also used in the DDOG model. We compared the proposed model against the already well-established oriented difference-of-Gaussian (ODOG) model of brightness perception. Extensive simulations suggest that though for most illusions both ODOG and VCCF produce correct output, for certain intricate cases in which the ODOG filter fails to correctly predict the illusory effect, our proposed VCCF model continues to remain effective.


Assuntos
Sensibilidades de Contraste , Ilusões , Humanos , Distribuição Normal , Estimulação Luminosa , Vias Visuais , Percepção Visual
10.
Arch Virol ; 166(6): 1795-1799, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33839920

RESUMO

In this study, bacteriophage BSP7, a novel Bacillus subtilis-infecting member of the family Siphoviridae, was isolated from a Korean soybean-based fermented food, Deonjang, using B. subtilis ATCC 21336 as a host. The genome is 55,455 bp long with 39.92% G+C content. A total of 70 ORFs with no tRNA were detected in the genome. A distinct feature of the BSP7 genome among B. subtilis-infecting Siphoviridae family phages is the presence of putative ORFs related to biosynthesis of 7-cyano-7-deazaguanine (PreQ0), a precursor of queuosine and archaeosine biosynthesis. Bioinformatic analysis revealed that the genome of BSP7 does not exhibit any significant similarities to other phages with sequences in the NCBI database. A comparative genomic analysis also confirmed the uniqueness of BSP7 within the family Siphoviridae.


Assuntos
Bacillus subtilis/virologia , Genoma Viral , Guanina/análogos & derivados , Siphoviridae/genética , Sequência de Bases , DNA Viral/genética , Regulação Viral da Expressão Gênica/fisiologia , Guanina/biossíntese , Siphoviridae/isolamento & purificação , Proteínas Virais/genética , Proteínas Virais/metabolismo
11.
Phys Chem Chem Phys ; 22(17): 9616-9629, 2020 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-32324181

RESUMO

Determination of global minimum structures and elucidation of reaction paths or minimum energy paths between low-lying minima are of great chemical importance. To that end, we have used our own Adaptive Mutation Simulated Annealing method to determine the global minimum and the minimum energy paths for various isomerisation reactions for small to moderate-sized (MgO)n (n = 6-27) clusters, using the Born-Mayer potential with suitable parameter values. The minimum energy structures obtained by us match well with previously reported data and are used as guess structures for further optimisation at the DFT level (using the B3LYP functional and DGDZVP basis set). Our optimised structures are found to match very well with the further DFT optimised structures, where the comparison is done by determining the root mean square deviation values as well as the radial distribution function profiles. A scheme is proposed to determine the minimum energy paths for isomerisation reactions for some cluster sizes where the transition state/s obtained by us, at very low computational cost, match well with those obtained from further optimisation using DFT calculations. We have shown the efficacy of our method in determining the reaction pathways, even for cases that involve multi-step reactions.

12.
Arch Virol ; 164(3): 875-878, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30506469

RESUMO

Bacillus subtilis-infecting phage BSP38 was isolated from a sewage sample. Morphologically, BSP38 was found to be similar to members of the subfamily Spounavirinae, family Myoviridae. Its genome is 153,268 bp long with 41.8% G+C content and 254 putative open reading frames (ORFs) as well as six tRNAs. A distinguishing feature for this phage among the reported B. subtilis-infecting phages is the presence of an encoding ORF, putative tRNAHis guanylyltransferase-like protein. Genomic comparisons with the other reported phages strongly suggest that BSP38 should be considered a member of a new genus in the subfamily Spounavirinae.


Assuntos
Fagos Bacilares/genética , Bacillus subtilis/virologia , Genoma Viral , Myoviridae/genética , Fagos Bacilares/classificação , Fagos Bacilares/isolamento & purificação , Composição de Bases , Sequência de Bases , Dados de Sequência Molecular , Myoviridae/classificação , Myoviridae/isolamento & purificação , Filogenia , Análise de Sequência de DNA , Esgotos/virologia
13.
FASEB J ; 31(11): 5087-5101, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-28765172

RESUMO

In visceral leishmaniasis, we found that the antileishmanial drug Amp B produces a higher level of IL-1ß over the infected control. Moreover, administering anti-IL-1ß antibody to infected Amp B-treated mice showed significantly less parasite clearance. Investigation revealed that Leishmania inhibits stimuli-induced expression of a multiprotein signaling platform, NLRP3 inflammasome, which in turn inhibits caspase-1 activation mediated maturation of IL-1ß from its pro form. Attenuation of NLRP3 and pro-IL-1ß in infection was found to result from decreased NF-κB activity. Transfecting infected cells with constitutively active NF-κB plasmid increased NLRP3 and pro-IL-1ß expression but did not increase mature IL-1ß, suggesting that IL-1ß maturation requires a second signal, which was found to be reactive oxygen species (ROS). Decreased NF-κB was attributed to increased expression of A20, a negative regulator of NF-κB signaling. Silencing A20 in infected cells restored NLRP3 and pro-IL-1ß expression, but also increased matured IL-1ß, implying an NF-κB-independent A20-modulated IL-1ß maturation. Macrophage ROS is primarily regulated by mitochondrial uncoupling protein 2 (UCP2), and UCP2-silenced infected cells showed an increased IL-1ß level. Short hairpin RNA-mediated knockdown of A20 and UCP2 in infected mice independently documented decreased liver and spleen parasite burden and increased IL-1ß production. These results suggest that Leishmania exploits A20 and UCP2 to impair inflammasome activation for disease propagation.-Gupta, A. K., Ghosh, K., Palit, S., Barua, J., Das, P. K., Ukil, A. Leishmania donovani inhibits inflammasome-dependent macrophage activation by exploiting the negative regulatory proteins A20 and UCP2.


Assuntos
Inflamassomos/metabolismo , Leishmania donovani/metabolismo , Leishmaniose Visceral/metabolismo , Ativação de Macrófagos , Macrófagos/metabolismo , Proteína 3 Induzida por Fator de Necrose Tumoral alfa/biossíntese , Proteína Desacopladora 2/biossíntese , Animais , Inflamassomos/genética , Interleucina-1beta/biossíntese , Interleucina-1beta/genética , Leishmaniose Visceral/genética , Leishmaniose Visceral/patologia , Macrófagos/parasitologia , Macrófagos/patologia , Camundongos , NF-kappa B/genética , NF-kappa B/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/genética , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Espécies Reativas de Oxigênio/economia , Espécies Reativas de Oxigênio/metabolismo , Proteína 3 Induzida por Fator de Necrose Tumoral alfa/genética , Proteína Desacopladora 2/genética
14.
Biol Cybern ; 112(3): 237-251, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29354875

RESUMO

We present a parsimonious model of brightness induction which can account for various brightness illusions of both brightness-contrast and brightness-assimilation types. Our model is based on a difference of difference-of-Gaussian filter and a two-pass model of attentive vision based on the parallel channels in the central visual pathway. It overcomes some of the problems that could not be addressed by the well-known oriented difference of Gaussian model like those associated with Mach band and checkerboard illusions. This model attempts to provide insight to the mechanism of attention in brightness perception through the two major complimentary visual channels, viz. the magnocellular and the parvocellular.


Assuntos
Simulação por Computador , Sensibilidades de Contraste/fisiologia , Modelos Biológicos , Fluxo Óptico/fisiologia , Algoritmos , Humanos , Ilusões/fisiologia , Estimulação Luminosa , Psicofísica
15.
Food Microbiol ; 76: 196-203, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30166141

RESUMO

While the detrimental effect of bacteriophages on lactic acid bacterial fermentation is well documented, the importance of Bacillus subtilis phages in soybean-based fermented foods is not. In this study, we show for the first time that 100% of Korean soybean-based fermented foods (Doenjang, Gochujang, and Cheonggukjang) and 70% of raw materials (Meju and rice straw) were contaminated with B. subtilis-infecting phages (as high as 3.7 × 104 PFU g-1). Among 15 isolated B. subtilis-infecting phages, BSP18 was selected for further studies due to its specificity to and relatively broad host infectivity (34%) against B. subtilis. This Myoviridae family phage, BSP18 could infect all of the tested wild-type and commercially-used strains for soybean-based fermented food preparation. Furthermore, artificial contamination of as low as 102 PFU g-1 of BSP18 significantly inhibited B. subtilis growth during Cheonggukjang fermentation. Moreover, phage-treated samples contained considerably more degraded γ-PGA which could negatively affect the functional property of Cheonggukjang. We also present the data, strongly suggesting BSP18-encoded, not bacterial, γ-PGA hydrolase was responsible for γ-PGA degradation. In conclusion, B. subtilis phages are widespread in Korean soybean-based fermented foods and it should be of great concern as phages may hamper the bacterial growth during fermentation and yield poor quality products.


Assuntos
Bacillus subtilis/crescimento & desenvolvimento , Bacillus subtilis/virologia , Bacteriófagos/isolamento & purificação , Myoviridae/isolamento & purificação , Alimentos de Soja/virologia , Bacillus subtilis/metabolismo , Bacteriófagos/metabolismo , República Democrática Popular da Coreia , Fermentação , Microbiologia de Alimentos/métodos , Myoviridae/genética , Oryza/microbiologia , Oryza/virologia , Ácido Poliglutâmico/análogos & derivados , Ácido Poliglutâmico/análise , Prevalência , Alimentos de Soja/microbiologia
16.
Arch Virol ; 162(7): 2145-2148, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28324178

RESUMO

Bacteriophage StAP1 was isolated from a soil sample infecting Staphylococcus aureus and S. xylosus. Its genome was found to be 135,502 base pairs (bp) long with 30.00 mol% G+C content and 192 open reading frames. While no tRNA encoding genes were identified, 7 mobile elements were found to interrupt five StAP1 open reading frames. Comparative genomic and proteomic analysis consistently supports the establishment of a new species in the genus Silviavirus.


Assuntos
Filogenia , Fagos de Staphylococcus/classificação , Staphylococcus aureus/virologia , Composição de Bases , Fases de Leitura Aberta , Proteômica , Análise de Sequência de DNA , Microbiologia do Solo , Fagos de Staphylococcus/genética , Fagos de Staphylococcus/ultraestrutura , Proteínas Virais/genética
17.
Biol Cybern ; 110(2-3): 229-36, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-27016101

RESUMO

The present work proposes a unified model to explain two previously reported properties of the Mach band illusion. The first is the frequently referenced fact that Mach bands are prominently visible at ramps, but practically vanish at intensity steps. The second property, less studied, on the other hand may also be related to the first. It concerns the fact that the width of the illusory Mach bands appears to be a function of the slope of the ramp itself. The model proposed here combines the difference of Gaussians (DOG) model of lateral inhibition in receptive fields with the models of feature detection, based on a holistic approach. The sharpness of discontinuity (SOD) concept for Mach band stimulus has been defined and is related to the slope of the ramp. It is suggested that calculation of SOD leads to an adaptive change in inhibitory surround, a notion that has the support of physiological experiments too.


Assuntos
Ilusões/fisiologia , Modelos Neurológicos , Distribuição Normal
19.
J Basic Microbiol ; 54 Suppl 1: S142-51, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23832828

RESUMO

An endoglucanase from Aspergillus fumigatus ABK9 was purified from the culture extract of solid-state fermentation and its some characteristics were evaluated. The molecular weight of the purified enzyme (56.3 kDa) was determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, zymogram analysis and confirmed by MALDI-TOF mass spectrometry. The enzyme was active optimally at 50 °C, pH 5.0 and stable over a broad range of pH (4.0-7.0) and NaCl concentration of 0-3.0 M. The pKa1 and pKa2 of the ionizable groups of the active sites were 2.94 and 6.53, respectively. The apparent Km , Vmax , and Kcat values for carboxymethyl cellulose were 6.7 mg ml(-1), 775.4 µmol min(-1) , and 42.84 × 10(4) s(-1), respectively. Thermostability of the enzyme was evidenced by the high activation energy (91.45 kJ mol(-1)), large enthalpy for activation of denaturation (88.77 kJ mol(-1)), longer half-life (T1/2) (433 min at 50 °C), higher melting temperature (Tm ) (73.5 °C), and Q10 (1.3) values. All the characteristics favors its suitability as halotolerant and thermostable enzyme during bioprocessing of lignocellulosic materials.


Assuntos
Aspergillus fumigatus/enzimologia , Celulase/química , Celulase/metabolismo , Carboximetilcelulose Sódica/metabolismo , Celulase/isolamento & purificação , Eletroforese em Gel de Poliacrilamida , Estabilidade Enzimática , Concentração de Íons de Hidrogênio , Cinética , Peso Molecular , Cloreto de Sódio/metabolismo , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Temperatura
20.
J Infect Dis ; 207(6): 1016-25, 2013 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-23255562

RESUMO

The aim of this study was to evaluate and characterize the therapeutic potential of curdlan, a naturally occurring ß-glucan immunomodulator, against visceral leishmaniasis, a fatal parasitic disease. Curdlan eliminated the liver and spleen parasite burden in a 45-day BALB/c mouse model of visceral leishmaniasis at a dosage of 10 mg/kg/day as determined by Giemsa-stained organ impression smears. Curdlan was associated with production of the disease-resolving T-helper (Th) 1 and Th17-inducing cytokines interleukin (IL)-6, IL-1ß, and IL-23, as well as with production of Th17 cytokines IL-17 and IL-22, as determined by enzyme-linked immunosorbent assay (ELISA) and real time polymerase chain reaction (RT-PCR). Reversal of curdlan-mediated protection by anti-IL-17 and anti-IL-23 monoclonal antibodies showed the importance of Th17 cytokines. Significantly decreased production of both IL-17 and IL-22 by mice that received anti-IL-23 antibody suggested the essential role of IL-23 in Th17 differentiation. Although administration of recombinant IL-17 or IL-23 caused significant suppression of the organ parasite burden, with marked generation of interferon γ and nitric oxide (NO), effects were much faster for IL-17. These results documented that although both IL-23 and IL-17 play major roles in the antileishmanial effect of curdlan, the effect of IL-23 may occur indirectly, through the induction of IL-17 production.


Assuntos
Fatores Imunológicos/farmacologia , Interleucina-17/imunologia , Interleucina-23/imunologia , Leishmaniose Visceral/tratamento farmacológico , Células Th17/metabolismo , beta-Glucanas/farmacologia , Animais , Anticorpos Monoclonais/farmacologia , Modelos Animais de Doenças , Fatores Imunológicos/uso terapêutico , Interferon gama/metabolismo , Interleucina-1/metabolismo , Interleucina-17/metabolismo , Interleucina-1beta/metabolismo , Interleucina-23/metabolismo , Interleucinas/imunologia , Interleucinas/metabolismo , Leishmania donovani/efeitos dos fármacos , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Óxido Nítrico/metabolismo , Células Th1/metabolismo , Células Th17/efeitos dos fármacos , beta-Glucanas/uso terapêutico , Interleucina 22
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