212 research outputs found
Body, Self and Consciousness according to Tirumūlar’s Tirumandiram: A comparative study with Kashmir Śaivism
Tirumular’s Tirumandiram is the earliest known Tamil treatise on yoga. This text is considered to be both, a devotional work as well as a tantric text. Unlike other major Siddha compositions, Tirumandiram does not contain any section on medicinal preparations or alchemy. It is the only Tamil text where the sections are named tanṭiram. In contrast to the popular pluralistic Śaiva Siddhānta, Tirumandiram, one of the twelve Saiva cannons (tirumurai), is monistic in its philosophy. This study, while elaborating on the metaphysics of the text Tirumandiram, also examines the shared philosophical thoughts between the monistic Kashmir Śaivism and Tamil Siddha mystics
Targeting cancer metabolism: a therapeutic window opens
Genetic events in cancer activate signalling pathways that alter cell metabolism. Clinical evidence has linked cell metabolism with cancer outcomes. Together, these observations have raised interest in targeting metabolic enzymes for cancer therapy, but they have also raised concerns that these therapies would have unacceptable effects on normal cells. However, some of the first cancer therapies that were developed target the specific metabolic needs of cancer cells and remain effective agents in the clinic today. Research into how changes in cell metabolism promote tumour growth has accelerated in recent years. This has refocused efforts to target metabolic dependencies of cancer cells as a selective anticancer strategy.Burroughs Wellcome FundSmith Family FoundationStarr Cancer ConsortiumDamon Runyon Cancer Research FoundationNational Institutes of Health (U.S.
Using C. elegans to decipher the cellular and molecular mechanisms underlying neurodevelopmental disorders
Prova tipográfica (uncorrected proof)Neurodevelopmental disorders such as epilepsy, intellectual disability (ID), and autism spectrum disorders (ASDs) occur in over 2 % of the population, as the result of genetic mutations, environmental factors, or combination of both. In the last years, use of large-scale genomic techniques allowed important advances in the identification of genes/loci associated with these disorders. Nevertheless, following association of novel genes with a given disease, interpretation of findings is often difficult due to lack of information on gene function and effect of a given mutation in the corresponding protein. This brings the need to validate genetic associations from a functional perspective in model systems in a relatively fast but effective manner. In this context, the small nematode, Caenorhabditis elegans, presents a good compromise between the simplicity of cell models and the complexity of rodent nervous systems. In this article, we review the features that make C. elegans a good model for the study of neurodevelopmental diseases. We discuss its nervous system architecture and function as well as the molecular basis of behaviors that seem important in the context of different neurodevelopmental disorders. We review methodologies used to assess memory, learning, and social behavior as well as susceptibility to seizures in this organism. We will also discuss technological progresses applied in C. elegans neurobiology research, such as use of microfluidics and optogenetic tools. Finally, we will present some interesting examples of the functional analysis of genes associated with human neurodevelopmental disorders and how we can move from genes to therapies using this simple model organism.The authors would like to acknowledge Fundação para a Ciência e Tecnologia (FCT) (PTDC/SAU-GMG/112577/2009). AJR and CB are recipients of FCT fellowships: SFRH/BPD/33611/2009 and SFRH/BPD/74452/2010, respectively
Microbiological, Physicochemical, and Histological Analyses of Broiler Carcasses with Cachexia
Interleukin-6 trans signalling enhances photodynamic therapy by modulating cell cycling
Photodynamic therapy (PDT) of solid tumours causes tissue damage that elicits local and systemic inflammation with major involvement of interleukin-6 (IL-6). We have previously reported that PDT-treated cells lose responsiveness to IL-6 cytokines. Therefore, it is unclear whether PDT surviving tumour cells are subject to regulation by IL-6 and whether this regulation could contribute to tumour control by PDT. We demonstrate in epithelial tumour cells that while the action of IL-6 cytokines through their membrane receptors is attenuated, regulation by IL-6 via trans-signalling is established. Soluble interleukin-6 receptor-α (IL-6Rα) (sIL-6Rα) and IL-6 were released by leucocytes in the presence of conditioned medium from PDT-treated tumour cells. Cells that had lost their membrane receptor IL-6Rα due to PDT responded to treatment with the IL-6R–IL-6 complex (Hyper-IL-6) with activation of signal transducers and activator of transcription (STAT3) and ERK. Photodynamic therapy-treated cells, which were maintained during post-PDT recovery in presence of IL-6 or Hyper-IL-6, showed an enhanced suppression of proliferation. Cytokine-dependent inhibition of proliferation correlated with a decrease in cyclin E, CDK2 and Cdc25A, and enhancement of p27kip1 and hypophosphorylated Rb. The IL-6 trans-signalling-mediated attenuation of cell proliferation was also effective in vivo detectable by an improved Colon26 tumour cure by PDT combined with Hyper-IL-6 treatment. Prevention of IL-6 trans-signalling using soluble gp130 reduced curability. The data suggest that the post-PDT tumour milieu contains the necessary components to establish effective IL-6 trans-signalling, thus providing a means for more effective tumour control
In Vivo Deficiency of Both C/EBPβ and C/EBPε Results in Highly Defective Myeloid Differentiation and Lack of Cytokine Response
The CCAAT/enhancer binding proteins (C/EBPs) are transcription factors involved in hematopoietic cell development and induction of several inflammatory mediators. Here, we generated C/EBPβ and C/EBPε double-knockout (bbee) mice and compared their phenotypes to those of single deficient (bbEE and BBee) and wild-type (BBEE) mice. The bbee mice were highly susceptible to fatal infections and died within 2–3 months. Morphologically, their neutrophils were blocked at the myelocytes/metamyelocytes stage, and clonogenic assays of bone marrow cells indicated a significant decrease in the number of myeloid colonies of the bbee mice. In addition, the proportion of hematopoietic progenitor cells [Lin(−)Sca1(+)c-Kit(+)] in the bone marrow of the bbee mice was significantly increased, reflecting the defective differentiation of the myeloid compartment. Furthermore, microarray expression analysis of LPS- and IFNγ-activated bone marrow-derived macrophages from bbee compared to single knockout mice revealed decreased expression of essential immune response-related genes and networks, including some direct C/EBP-targets such as Marco and Clec4e. Overall, the phenotype of the bbee mice is distinct from either the bbEE or BBee mice, demonstrating that both transcription factors are crucial for the maturation of neutrophils and macrophages, as well as the innate immune system, and can at least in part compensate for each other in the single knockout mice
Prostaglandin E2 Signals Through PTGER2 to Regulate Sclerostin Expression
The Wnt signaling pathway is a robust regulator of skeletal homeostasis. Gain-of-function mutations promote high bone mass, whereas loss of Lrp5 or Lrp6 co-receptors decrease bone mass. Similarly, mutations in antagonists of Wnt signaling influence skeletal integrity, in an inverse relation to Lrp receptor mutations. Loss of the Wnt antagonist Sclerostin (Sost) produces the generalized skeletal hyperostotic condition of sclerosteosis, which is characterized by increased bone mass and density due to hyperactive osteoblast function. Here we demonstrate that prostaglandin E2 (PGE2), a paracrine factor with pleiotropic effects on osteoblasts and osteoclasts, decreases Sclerostin expression in osteoblastic UMR106.01 cells. Decreased Sost expression correlates with increased expression of Wnt/TCF target genes Axin2 and Tcf3. We also show that the suppressive effect of PGE2 is mediated through a cyclic AMP/PKA pathway. Furthermore, selective agonists for the PGE2 receptor EP2 mimic the effect of PGE2 upon Sost, and siRNA reduction in Ptger2 prevents PGE2-induced Sost repression. These results indicate a functional relationship between prostaglandins and the Wnt/β-catenin signaling pathway in bone
Space- and time-resolved investigation on diffusion kinetics of human skin following macromolecule delivery by microneedle arrays
Microscale medical devices are being developed for targeted skin delivery of vaccines and the extraction of biomarkers, with the potential to revolutionise healthcare in both developing and developed countries. The effective clinical development of these devices is dependent on understanding the macro-molecular diffusion properties of skin. We hypothesised that diffusion varied according to specific skin layers. Using three different molecular weights of rhodamine dextran (RD) (MW of 70, 500 and 2000 kDa) relevant to the vaccine and therapeutic scales, we deposited molecules to a range of depths (0–300 µm) in ex vivo human skin using the Nanopatch device. We observed significant dissipation of RD as diffusion with 70 and 500 kDa within the 30 min timeframe, which varied with MW and skin layer. Using multiphoton microscopy, image analysis and a Fick’s law analysis with 2D cartesian and axisymmetric cylindrical coordinates, we reported experimental trends of epidermal and dermal diffusivity values ranging from 1–8 µm2 s-1 to 1–20 µm2 s-1 respectively, with a significant decrease in the dermal-epidermal junction of 0.7–3 µm2 s-1. In breaching the stratum corneum (SC) and dermal-epidermal junction barriers, we have demonstrated practical application, delivery and targeting of macromolecules to both epidermal and dermal antigen presenting cells, providing a sound knowledge base for future development of skin-targeting clinical technologies in humans
5, 8, 11, 14-eicosatetraynoic acid suppresses CCL2/MCP-1 expression in IFN-γ-stimulated astrocytes by increasing MAPK phosphatase-1 mRNA stability
<p>Abstract</p> <p>Background</p> <p>The peroxisome proliferator-activated receptor (PPAR)-α activator, 5,8,11,14-eicosatetraynoic acid (ETYA), is an arachidonic acid analog. It is reported to inhibit up-regulation of pro-inflammatory genes; however, its underlying mechanism of action is largely unknown. In the present study, we focused on the inhibitory action of ETYA on the expression of the chemokine, CCL2/MCP-1, which plays a key role in the initiation and progression of inflammation.</p> <p>Methods</p> <p>To determine the effect of ETYA, primary cultured rat astrocytes and microglia were stimulated with IFN-γ in the presence of ETYA and then, expression of CCL2/MCP-1 and MAPK phosphatase (MKP-1) were determined using RT-PCR and ELISA. MKP-1 mRNA stability was evaluated by treating actinomycin D. The effect of MKP-1 and human antigen R (HuR) was analyzed by using specific siRNA transfection system. The localization of HuR was analyzed by immunocytochemistry and subcellular fractionation experiment.</p> <p>Results</p> <p>We found that ETYA suppressed CCL2/MCP-1 transcription and secretion of CCL2/MCP-1 protein through up-regulation of MKP-1mRNA levels, resulting in suppression of c-Jun N-terminal kinase (JNK) phosphorylation and activator protein 1 (AP1) activity in IFN-γ-stimulated brain glial cells. Moreover, these effects of ETYA were independent of PPAR-α. Experiments using actinomycin D revealed that the ETYA-induced increase in MKP-1 mRNA levels reflected an increase in transcript stability. Knockdown experiments using small interfering RNA demonstrated that this increase in MKP-1 mRNA stability depended on HuR, an RNA-binding protein known to promote enhanced mRNA stability. Furthermore, ETYA-induced, HuR-mediated mRNA stabilization resulted from HuR-MKP-1 nucleocytoplasmic translocation, which served to protect MKP-1 mRNA from the mRNA degradation machinery.</p> <p>Conclusion</p> <p>ETYA induces MKP-1 through HuR at the post-transcriptional level in a receptor-independent manner. The mechanism revealed here suggests eicosanoids as potential therapeutic modulators of inflammation that act through a novel target.</p
Cancer Risk in Diabetic Patients Treated with Metformin: A Systematic Review and Meta-analysis
BACKGROUND: A growing body of evidence has suggested that metformin potentially reduces the risk of cancer. Our objective was to enhance the precision of estimates of the effect of metformin on the risk of any-site and site-specific cancers in patients with diabetes. METHODS/PRINCIPAL FINDINGS: We performed a search of MEDLINE, EMBASE, ISI Web of Science, Cochrane Library, and ClinicalTrials.gov for pertinent articles published as of October 12, 2011, and included them in a systematic review and meta-analysis. We calculated pooled risk ratios (RRs) for overall cancer mortality and cancer incidence. Of the 21,195 diabetic patients reported in 6 studies (4 cohort studies, 2 RCTs), 991 (4.5%) cases of death from cancer were reported. A total of 11,117 (5.3%) cases of incident cancer at any site were reported among 210,892 patients in 10 studies (2 RCTs, 6 cohort studies, 2 case-control studies). The risks of cancer among metformin users were significantly lower than those among non-metformin users: the pooled RRs (95% confidence interval) were 0.66 (0.49-0.88) for cancer mortality, 0.67 (0.53-0.85) for all-cancer incidence, 0.68 (0.53-0.88) for colorectal cancer (n = 6), 0.20 (0.07-0.59) for hepatocellular cancer (n = 4), 0.67 (0.45-0.99) for lung cancer (n = 3). CONCLUSION/SIGNIFICANCE: The use of metformin in diabetic patients was associated with significantly lower risks of cancer mortality and incidence. However, this analysis is mainly based on observational studies and our findings underscore the more need for long-term RCTs to confirm this potential benefit for individuals with diabetes
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