304 research outputs found
Efecto inhibitorio de extractos de Renealmia alpinia Rottb. Maas (Zingiberaceae) sobre el veneno de Bothrops asper (mapaná)
Introduction. Traditional medicine is an invaluable source of research into new medicines as asupplement for the treatment of snakebite, considered as a serious public health problem worldwide.The extracts of the medicinal plant, Renealmia alpina, have been used traditionally by indigenouspeople of Chocó (Colombia) against Bothrops asper snakebite, a snake responsible for the majority ofsnakebite accidents in Colombia.Objective. The ability of extracts of R. alpinia leaves was tested for its ability to neutralize thehemorrhagic, coagulant and proteolytic effects of the snakebite venom of B. asper.Materials and methods. The acute toxicity tests and analgesic activity of R. alpina were evaluated in vivo. In addition, tests were undertaken in in vitro conditions to demonstrate inhibition of coagulant,haemolytic and proteolytic activity of the B. asper venom.Results. Renealmia alpinia extracts had no toxic effects in experimental animals and also providedanalgesic and antiophidian effects and protection against the lethal effects of the venom of B. asper.Conclusion. Renealmia. alpinia was an effective therapeutic alternative in association with antivenomtreatment in the event of a B. asper snakebite accident. It was demonstrated to protect against thelethal effects and provided analgesic properties as well. doi: http://dx.doi.org/10.7705/biomedica.v32i3.591Introducción. La medicina tradicional es una invaluable fuente de investigación de nuevos remedioscomo complemento para el tratamiento del accidente ofídico, considerado como un grave problema desalud pública a nivel mundial.Objetivo. Este trabajo de investigación pretende comprobar la capacidad de neutralizar los efectoshemorrágicos, coagulantes y proteolíticos, de los extractos de hojas de Renealmia alpinia, usadatradicionalmente por los indígenas del Chocó (Colombia) contra la mordedura de la serpiente Bothropsasper, causante de la gran mayoría de los accidentes ofídicos en nuestro país.Materiales y métodos. Se llevaron a cabo ensayos de toxicidad aguda y de actividad analgésica in vivo de R. alpinia. Además, se hicieron ensayos in vitro sobre inhibición de las actividades coagulante,hemolítica y proteolítica del veneno de Resultados. El presente estudio demuestra que R. alpinia no produce efectos tóxicos en animales deexperimentación; además, presenta efectos analgésicos in vivo y antiofídicos in vitro, y protege contralos efectos letales del veneno de B. asper, in vivo.Conclusión. Renealmia alpinia puede ser una buena alternativa terapéutica como complemento altratamiento con antiveneno en el accidente ofídico, por sus efectos analgésicos y antiofídicos.doi: http://dx.doi.org/10.7705/biomedica.v32i3.591
CD45 Isoform Expression in Microglia and Inflammatory Cells in HIV-1 Encephalitis
CD45 is a membrane tyrosine phosphatase that modulates the function of the hematopoietic cells. In vitro, agonist antibodies to CD45RO or CD45RB isoforms have been shown to suppress microglial activation, but whether microglia in vivo express these isoforms in HIV encephalitis (HIVE) is unknown. Brain sections from control and HIVE were immunostained for CD45 isoforms using exon-specific antibodies (RA, RB, RC and RO). RA and RC were limited to rare lymphocytes, while RB expression was robust in microglia and inflammatory cells. RO was low in control microglia, but increased in HIVE. RO was also localized to macrophages and CD8+ T cells. Targeting CD45 in vivo with isoform-specific antibodies remains a therapeutic option for neuroinflammatory diseases
An Intelligent Decision Support System for the Detection of Meat Spoilage using Multispectral Images
In food industry, quality and safety are considered important issues worldwide that are directly related to health and social progress. The use of vision technology for quality testing of food production has the obvious advantage of being able to continuously monitor a production using non-destructive methods, thus increasing the quality and minimizing cost. The performance of an intelligent decision support system has been evaluated in monitoring the spoilage of minced beef stored either aerobically or under modified atmosphere packaging, at different storage temperatures (0, 5, 10, and 15 °C) utilising multispectral imaging information. This paper utilises a neuro-fuzzy model which incorporates a clustering pre-processing stage for the definition of fuzzy rules, while its final fuzzy rule base is determined by competitive learning. Initially, meat samples are classified according to their storage conditions, while identification models are then utilised for the prediction of the Total Viable Counts of bacteria. The innovation of the proposed approach is further extended to the identification of the temperature used for storage, utilizing only imaging spectral information. Results indicated that spectral information in combination with the proposed modelling scheme could be considered as an alternative methodology for the accurate evaluation of meat spoilage
AGT haplotype in ITGA4 gene is related to antibody-mediated rejection in heart transplant patients
[Abstract] Introduction.
One of the main problems involved in heart transplantation (HT) is antibody-mediated rejection
(AMR). Many aspects of AMR are still unresolved, including its etiology, diagnosis and
treatment. In this project, we hypothesize that variants in genes involved in B-cell biology in
HT patients can yield diagnostic and prognostic information about AMR.
Methods.
Genetic variants in 61 genes related to B-cell biology were analyzed by next generation
sequencing in 46 HT patients, 23 with and 23 without AMR.
Results.
We identified 3 single nucleotide polymorphisms in ITGA4 gene (c.1845G>A, c.2633A>G,
and c.2883C>T) that conformed the haplotype AGT-ITGA4. This haplotype is associated
with the development of AMR. Moreover, AMR patients with the haplotype AGT-ITGA4
present lower levels of integrin α-4 in serum samples compared to the reference GAC haplotype
in control patients.
Conclusion.
We can conclude that polymorphisms in genes related to the biology of B-cells could have
an important role in the development of AMR. In fact, the AGT haplotype in ITGA4 gene
could potentially increase the risk of AMR.Instituto de Salud Carlos III; PI13/0217
Natural polymorphisms in C. elegans HECW-1 E3 ligase affect pathogen avoidance behaviour
available in PMC 2012 June 22.Heritable variation in behavioural traits generally has a complex genetic basis1, and thus naturally
occurring polymorphisms that influence behaviour have been defined in only rare instances2,3.
The isolation of wild strains of Caenorhabditis elegans has facilitated the study of natural genetic
variation in this species4 and provided insights into its diverse microbial ecology5. C. elegans
responds to bacterial infection with conserved innate immune responses6-8 and, while lacking the
immunological memory of vertebrate adaptive immunity, exhibits an aversive learning response to
pathogenic bacteria9. Here, we report the molecular characterization of naturally occurring coding
polymorphisms in a C. elegans gene encoding a conserved HECT domain-containing E3 ubiquitin
ligase, HECW-1. We show that two distinct polymorphisms in neighbouring residues of HECW-1
each affect C. elegans behavioural avoidance of a lawn of Pseudomonas aeruginosa. Neuronspecific
rescue and ablation experiments, and genetic interaction analysis suggest that HECW-1
functions in a pair of sensory neurons to inhibit P. aeruginosa lawn avoidance behaviour through
inhibition of the neuropeptide receptor NPR-110, which we have previously shown promotes P.
aeruginosa lawn avoidance behaviour11. Our data establish a molecular basis for natural variation
in a C. elegans behaviour that may undergo adaptive changes in response to microbial pathogens.National Institutes of Health (U.S.) (NIH Grant GM084477
PPARβ activation inhibits melanoma cell proliferation involving repression of the Wilms’ tumour suppressor WT1
Peroxisome proliferator-activated receptors (PPARs) are ligand-activated transcription factors that strongly influence molecular signalling in normal and cancer cells. Although increasing evidence suggests a role of PPARs in skin carcinogenesis, only expression of PPARγ has been investigated in human melanoma tissues. Activation of PPARα has been shown to inhibit the metastatic potential, whereas stimulation of PPARγ decreased melanoma cell proliferation. We show here that the third member of the PPAR family, PPARβ/δ is expressed in human melanoma samples. Specific pharmacological activation of PPARβ using GW0742 or GW501516 in low concentrations inhibits proliferation of human and murine melanoma cells. Inhibition of proliferation is accompanied by decreased expression of the Wilms’ tumour suppressor 1 (WT1), which is implicated in melanoma proliferation. We demonstrate that PPARβ directly represses WT1 as (1) PPARβ activation represses WT1 promoter activity; (2) in chromatin immunoprecipitation and electrophoretic mobility shift assays, we identified a binding element for PPARβ in the WT1 promoter; (3) deletion of this binding element abolishes repression by PPARβ and (4) the WT1 downstream molecules nestin and zyxin are down-regulated upon PPARβ activation. Our findings elucidate a novel mechanism of signalling by ligands of PPARβ, which leads to suppression of melanoma cell growth through direct repression of WT1
Anthropometric and glucometabolic changes in an aged mouse model of lipocalin-2 overexpression
Background:: Lipocalin-2 (LCN2) is widely expressed in the organism with pleiotropic roles. In particular, its overexpression correlates with tissue stress conditions including inflammation, metabolic disorders, chronic diseases and cancer. Objectives:: To assess the effects of systemic LCN2 overexpression on adipose tissue and glucose metabolism. Subjects:: Eighteen-month-old transgenic mice with systemic LCN2 overexpression (LCN2-Tg) and age/sex-matched wild-type mice. Methods:: Metabolic cages; histology and real-time PCR analysis; glucose and insulin tolerance tests; ELISA; flow cytometry; microPET and serum analysis. Results:: LCN2-Tg mice were smaller compared to controls but they ate (P = 0.0156) and drank (P = 0.0057) more and displayed a higher amount of visceral adipose tissue. Furthermore, LCN2-Tg mice with body weight 6520 g showed adipocytes with a higher cell area (P < 0.0001) and altered expression of genes involved in adipocyte differentiation and inflammation. In particular, mRNA levels of adipocyte-derived Pparg (P 64 0.0001), Srebf1 (P < 0.0001), Fabp4 (P = 0.056), Tnfa (P = 0.0391), Il6 (P = 0.0198), and Lep (P = 0.0003) were all increased. Furthermore, LCN2-Tg mice displayed a decreased amount of basal serum insulin (P = 0.0122) and a statistically significant impaired glucose tolerance and insulin sensitivity consistent with Slc2a2 mRNA (P 64 0.0001) downregulated expression. On the other hand, Insr mRNA (P 64 0.0001) was upregulated and correlated with microPET analysis that demonstrated a trend in reduced whole-body glucose consumption and MRGlu in the muscles and a significantly reduced MRGlu in brown adipose tissue (P = 0.0247). Nevertheless, an almost nine-fold acceleration of hexokinase activity was observed in the LCN2-Tg mice liver compared to controls (P = 0.0027). Moreover, AST and ALT were increased (P = 0.0421 and P = 0.0403, respectively), which indicated liver involvement also demonstrated by histological staining. Conclusions:: We show that LCN2 profoundly impacts adipose tissue size and function and glucose metabolism, suggesting that LCN2 should be considered as a risk factor in ageing for metabolic disorders leading to obesity
Protein Phosphatase 2A Interacts with the Na+,K+-ATPase and Modulates Its Trafficking by Inhibition of Its Association with Arrestin
Background: The P-type ATPase family constitutes a collection of ion pumps that form phosphorylated intermediates during ion transport. One of the best known members of this family is the Na +,K +-ATPase. The catalytic subunit of the Na +,K +-ATPase includes several functional domains that determine its enzymatic and trafficking properties. Methodology/Principal Findings: Using the yeast two-hybrid system we found that protein phosphatase 2A (PP2A) catalytic C-subunit is a specific Na +,K +-ATPase interacting protein. PP-2A C-subunit interacted with the Na +,K +-ATPase, but not with the homologous sequences of the H +,K +-ATPase. We confirmed that the Na +,K +-ATPase interacts with a complex of A- and C-subunits in native rat kidney. Arrestins and G-protein coupled receptor kinases (GRKs) are important regulators of G-protein coupled receptor (GPCR) signaling, and they also regulate Na +,K +-ATPase trafficking through direct association. PP2A inhibits association between the Na +,K +-ATPase and arrestin, and diminishes the effect of arrestin on Na +,K +-ATPase trafficking. GRK phosphorylates the Na +,K +-ATPase and PP2A can at least partially reverse this phosphorylation. Conclusions/Significance: Taken together, these data demonstrate that the sodium pump belongs to a growing list of io
Changes in Lysozyme Flexibility upon Mutation Are Frequent, Large and Long-Ranged
We investigate changes in human c-type lysozyme flexibility upon mutation via a Distance Constraint Model, which gives a statistical mechanical treatment of network rigidity. Specifically, two dynamical metrics are tracked. Changes in flexibility index quantify differences within backbone flexibility, whereas changes in the cooperativity correlation quantify differences within pairwise mechanical couplings. Regardless of metric, the same general conclusions are drawn. That is, small structural perturbations introduced by single point mutations have a frequent and pronounced affect on lysozyme flexibility that can extend over long distances. Specifically, an appreciable change occurs in backbone flexibility for 48% of the residues, and a change in cooperativity occurs in 42% of residue pairs. The average distance from mutation to a site with a change in flexibility is 17–20 Å. Interestingly, the frequency and scale of the changes within single point mutant structures are generally larger than those observed in the hen egg white lysozyme (HEWL) ortholog, which shares 61% sequence identity with human lysozyme. For example, point mutations often lead to substantial flexibility increases within the β-subdomain, which is consistent with experimental results indicating that it is the nucleation site for amyloid formation. However, β-subdomain flexibility within the human and HEWL orthologs is more similar despite the lowered sequence identity. These results suggest compensating mutations in HEWL reestablish desired properties
Task Selection and Workload: A Focus on Completing Easy Tasks Hurts Long-Term Performance
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