21 research outputs found

    Effects of Payena dasyphylla (Miq.) on hyaluronidase enzyme activity and metalloproteinases protein expressions in interleukin-1beta stimulated human chondrocytes cells

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    Background: Hyaluronidases have been found as the target enzymes in the development of osteoarthritis (OA) disease. While there is still no curative treatment for this disease, recent studies on the treatment of OA were focused on the effectiveness of natural products which are expected to improve the symptoms with minimal side effects. The aim of this study was to screen selected Malaysian plants on their anti-hyaluronidase activity as well as to evaluate the active plant and its derived fractions on its potential anti-arthritic and antioxidant activities.Methods: A total of 20 methanolic crude extracts (bark and leaf) from ten different plants were screened using a colorimetric hyaluronidase enzymatic assay. The active plant extract (Payena dasyphylla) was then studied for its hyaluronidase inhibitory activity in the interleukin-1β (IL-1β) stimulated human chondrocytes cell line (NHAC-kn) using zymography method. The Payena dasyphylla methanolic bark extract was then fractionated into several fractions in where the ethyl acetate (EA) fraction was evaluated for its inhibitory effects on the HYAL1 and HYAL2 gene expressions using reverse transcription-polymerase chain reaction (RT-PCR) technique. While the MMP-3 and MMP-13 protein expressions were evaluated using western blot method. The phenolic and flavonoid contents of the three fractions as well as the antioxidant property of the EA fraction were also evaluated.Results: Bark extract of Payena dasyphylla (100 μg/ml) showed the highest inhibitory activity against bovine testicular hyaluronidase with 91.63%. The plant extract also inhibited hyaluronidase expression in the cultured human chondrocyte cells in response to IL-1β (100 ng/ml). Similarly, treatment with Payena dasyphylla ethyl acetate (EA) fraction (100 μg/ml) inhibited the HYAL1 and HYAL2 mRNA gene expressions as well as MMP-3 and MMP-13 protein expression in a dose dependent manner. Payena dasyphylla EA fraction has demonstrated the highest amount of phenolic and flavonoid content with 168.62 ± 10.93 mg GAE/g and 95.96 ± 2.96 mg RE/g respectively as compared to water and hexane fractions. In addition, the Payena dasyphylla EA fraction showed strong antioxidant activity with IC50 value of 11.64 ± 1.69 μg/mL.Conclusion: These findings have shown that Payena dasyphylla might contained potential phenolic compounds that inhibiting the key enzyme in osteoarthritis development, which is the hyaluronidase enzyme through interruption of HYAL1 and HYAL1 gene expressions. The degradation of cartilage could also be inhibited by the plant through suppression of MMP-3 and MMP-13 protein expressions. We also reported that the inhibitory effect of Payena dasyphylla on hyaluronidase activity and expression might be due to its anti-oxidant property

    Evidence-based Kernels: Fundamental Units of Behavioral Influence

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    This paper describes evidence-based kernels, fundamental units of behavioral influence that appear to underlie effective prevention and treatment for children, adults, and families. A kernel is a behavior–influence procedure shown through experimental analysis to affect a specific behavior and that is indivisible in the sense that removing any of its components would render it inert. Existing evidence shows that a variety of kernels can influence behavior in context, and some evidence suggests that frequent use or sufficient use of some kernels may produce longer lasting behavioral shifts. The analysis of kernels could contribute to an empirically based theory of behavioral influence, augment existing prevention or treatment efforts, facilitate the dissemination of effective prevention and treatment practices, clarify the active ingredients in existing interventions, and contribute to efficiently developing interventions that are more effective. Kernels involve one or more of the following mechanisms of behavior influence: reinforcement, altering antecedents, changing verbal relational responding, or changing physiological states directly. The paper describes 52 of these kernels, and details practical, theoretical, and research implications, including calling for a national database of kernels that influence human behavior

    Cancer Biomarker Discovery: The Entropic Hallmark

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    Background: It is a commonly accepted belief that cancer cells modify their transcriptional state during the progression of the disease. We propose that the progression of cancer cells towards malignant phenotypes can be efficiently tracked using high-throughput technologies that follow the gradual changes observed in the gene expression profiles by employing Shannon's mathematical theory of communication. Methods based on Information Theory can then quantify the divergence of cancer cells' transcriptional profiles from those of normally appearing cells of the originating tissues. The relevance of the proposed methods can be evaluated using microarray datasets available in the public domain but the method is in principle applicable to other high-throughput methods. Methodology/Principal Findings: Using melanoma and prostate cancer datasets we illustrate how it is possible to employ Shannon Entropy and the Jensen-Shannon divergence to trace the transcriptional changes progression of the disease. We establish how the variations of these two measures correlate with established biomarkers of cancer progression. The Information Theory measures allow us to identify novel biomarkers for both progressive and relatively more sudden transcriptional changes leading to malignant phenotypes. At the same time, the methodology was able to validate a large number of genes and processes that seem to be implicated in the progression of melanoma and prostate cancer. Conclusions/Significance: We thus present a quantitative guiding rule, a new unifying hallmark of cancer: the cancer cell's transcriptome changes lead to measurable observed transitions of Normalized Shannon Entropy values (as measured by high-throughput technologies). At the same time, tumor cells increment their divergence from the normal tissue profile increasing their disorder via creation of states that we might not directly measure. This unifying hallmark allows, via the the Jensen-Shannon divergence, to identify the arrow of time of the processes from the gene expression profiles, and helps to map the phenotypical and molecular hallmarks of specific cancer subtypes. The deep mathematical basis of the approach allows us to suggest that this principle is, hopefully, of general applicability for other diseases

    Stereotypic horses (Equus caballus) are not cognitively impaired

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    Stereotypies in animals are thought to arise from an interaction between genetic predisposition and sub-optimal housing conditions. In domestic horses, a well-studied stereotypy is crib-biting, an abnormal behaviour that appears to help individuals to cope with stressful situations. One prominent hypothesis states that animals affected by stereotypies are cognitively less flexible compared to healthy controls, due to sensitization of a specific brain area, the basal ganglia. The aim of this study was to test this hypothesis in crib-biting and healthy controls, using a cognitive task, reversal learning, which has been used as a diagnostic for basal ganglia dysfunction. The procedure consisted of exposing subjects to four learning tasks; first and second acquisition, and their reversals. For each task, we measured the number of trials to reach criterion and heart rate and heart-rate variability. Importantly, we did not try to prevent crib-biters from executing their stereotypic behaviour. We found that the first reversal learning task required the largest number of trials, confirming its challenging nature. Interestingly, the second reversal learning task required significantly fewer trials to reach criterion, suggesting generalisation learning. However, we did not find any performance differences across groups; both stereotypic and control animals required a similar numbers of trials and did not differ in their physiological responses. Our results thus challenge the widely held belief that crib-biting horses, and stereotypic animals more generally, are cognitively impaired. We conclude that cognitive underperformance may occur in stereotypic horses if they are prevented from crib-biting to cope with experienced stress.PostprintPeer reviewe

    NHE8 Is Essential for RPE Cell Polarity and Photoreceptor Survival

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    A new N-ethyl-N-nitrosourea (ENU)-induced mouse recessive mutation, identified by fundus examination of the eye, develops depigmented patches, indicating retinal disorder. Histology data show aberrant retinal pigment epithelium (RPE) and late-onset photoreceptor cell loss in the mutant retina. Chromosomal mapping and DNA sequencing reveal a point mutation (T to A) of the Slc9a8 gene, resulting in mutant sodium/proton exchanger 8 (NHE8)-M120K protein. The lysine substitution decreases the probability of forming the 3(rd) transmembrane helix, which impairs the pore structure of the Na(+)/H(+) exchanger. Various RPE defects, including mislocalization of the apical marker ezrin, and disrupted apical microvilli and basal infoldings are observed in mutant mice. We have further generated NHE8 knockout mice and confirmed similar phenotypes, including abnormal RPE cells and late-onset photoreceptor cell loss. Both in vivo and in vitro data indicate that NHE8 co-localizes with ER, Golgi and intracellular vesicles in RPE cells. Thus, NHE8 function is necessary for the survival of photoreceptor cells and NHE8 is important for RPE cell polarity and function. Dysfunctional RPE may ultimately lead to photoreceptor cell death in the NHE8 mutants. Further studies will be needed to elucidate whether or not NHE8 regulates pH homeostasis in the protein secretory pathways of RPE

    Student Motivation and Resistance in Active Learning Classrooms

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    Although the positive effects of active learning (AL) on students’ learning and attitudes are well documented, there seems to be an equally large amount of evidence suggesting that students resist AL. In this chapter, we explore this AL paradox by describing a study that employed a novel AL approach aligned with reform documents and a consensus definition of AL in order to uncover sources of motivation from and resistance to AL. The purpose of the chapter is to aid college science instructors in recognizing these sources of motivation and resistance in their own classrooms so that they are able to emphasize the former and address the latter

    Opportunism or aquatic specialization? Evidence of freshwater fish exploitation at Ohalo II- A waterlogged Upper Paleolithic site

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