755 research outputs found

    A novel method for gene-specific enhancement of protein translation by targeting 5’UTRs of selected tumor suppressors

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    Background Translational control is a mechanism of protein synthesis regulation emerging as an important target for new therapeutics. Naturally occurring microRNAs and synthetic small inhibitory RNAs (siRNAs) are the most recognized regulatory molecules acting via RNA interference. Surprisingly, recent studies have shown that interfering RNAs may also activate gene transcription via the newly discovered phenomenon of small RNA-induced gene activation (RNAa). Thus far, the small activating RNAs (saRNAs) have only been demonstrated as promoter-specific transcriptional activators. Findings We demonstrate that oligonucleotide-based trans-acting factors can also specifically enhance gene expression at the level of protein translation by acting at sequence-specific targets within the messenger RNA 5’-untranslated region (5’UTR). We designed a set of short synthetic oligonucleotides (dGoligos), specifically targeting alternatively spliced 5’UTRs in transcripts expressed from the THRB and CDKN2A suppressor genes. The in vitro translation efficiency of reporter constructs containing alternative TRβ1 5’UTRs was increased by up to more than 55-fold following exposure to specific dGoligos. Moreover, we found that the most folded 5’UTR has higher translational regulatory potential when compared to the weakly folded TRβ1 variant. This suggests such a strategy may be especially applied to enhance translation from relatively inactive transcripts containing long 5’UTRs of complex structure. Significance This report represents the first method for gene-specific translation enhancement using selective trans-acting factors designed to target specific 5’UTR cis-acting elements. This simple strategy may be developed further to complement other available methods for gene expression regulation including gene silencing. The dGoligo-mediated translation-enhancing approach has the potential to be transferred to increase the translation efficiency of any suitable target gene and may have future application in gene therapy strategies to enhance expression of proteins including tumor suppressors

    PHARMACOGNOSTIC AND PHYTOCHEMICAL EVALUATION OF TREMA ORIENTALIS LEAF

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    Trema orientalis (Ulmaceae) is native to India. This tree species has been of interest to researchers because it is a medicinal plant employed in the Indian indigenous system of medicine. Pharmacognostic standardization, physic-chemical evaluation of the leafs of Trema orientalis was carried out to determine its macro-and micro-scopical characters and also some insoluble ash and sulphated ash values, alcohol-and water-soluble extractive values were determined for phytochemical evaluations. Preliminary phytochemical screening was also done to detect different phytoconstituents. Microscopically, Leaf showed trichomes, Lamina, midrib regions, stomata and calcium oxalate crystals. Powder microscopy showed mesophyll region, abundant xylem vessels with annular thickenings and xylem vessels, Unicellular, multiseriate covering trichomes and glandular trichomes, Rosette and prism shape calcium oxalate crystals, Anomocytic stomata. Total ash was approximately two times and four times more than acid insoluble and water soluble as, respectively Ethanol soluble extractive was approximately two times higher than water soluble extractive. TLC of petroleum ether and ethanol extract showed five spots using Hexane: Ethyl acetate (12:4) and four spot using Choloroform: Ethyl acetate (5:4). Phytochemically, root exhibited phytosterols, Flavanoids, Tannin and phenolic compounds

    Task-related enhancement in corticomotor excitability during haptic sensing with the contra- or ipsilateral hand in young and senior adults

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    <p>Abstract</p> <p>Background</p> <p>Haptic sensing with the fingers represents a unique class of manipulative actions, engaging motor, somatosensory and associative areas of the cortex while requiring only minimal forces and relatively simple movement patterns. Using transcranial magnetic stimulation (TMS), we investigated task-related changes in motor evoked potential (MEP) amplitude associated with unimanual haptic sensing in two related experiments. In Experiment I, we contrasted changes in the excitability of the hemisphere controlling the task hand in young and old adults under two trial conditions, i.e. when participants either touched a fine grating (<it>smooth trials</it>) or touched a coarse grating to detect its groove orientation (<it>grating trials</it>). In Experiment II, the same contrast between tasks was performed but with TMS applied over the hemisphere controlling the resting hand, while also addressing hemispheric (right vs. left) and age differences.</p> <p>Results</p> <p>In Experiment I, a main effect of <it>trial type </it>on MEP amplitude was detected (p = 0.001), MEPs in the task hand being ~50% larger during grating than smooth trials. No interaction with age was detected. Similar results were found for Experiment II, <it>trial type </it>having a large effect on MEP amplitude in the resting hand (p < 0.001) owing to selective increase in MEP size (~2.6 times greater) for grating trials. No interactions with age or side (right vs. left) were detected.</p> <p>Conclusions</p> <p>Collectively, these results indicate that adding a haptic component to a simple unilateral finger action can elicit robust corticomotor facilitation not only in the working hemisphere but also in the opposite hemisphere. The fact that this facilitation seems well preserved with age, when task difficulty is adjusted, has some potential clinical implications.</p

    Survey of Deoxyribonucleic Acid Motif Finding Algorithms

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    An important task in biology is to identify binding sites in DNA for transcription factors. These binding sites are short DNA segments which are called motifs. Given a set of DNA sequences, the motif finding problem is to detect overrepresented motifs that are good candidates for being transcription factor binding sites. The current study is a survey of motif finding algorithms. The study shows that a sensible approach to detect motif is to search for statistically overrepresented motifs in the promoter region of a set of co-regulated genes. The weak point of the available motif finding algorithms is that they tend to be sensitive to the noise, i.e., the presence of upstream sequences in data set that do not contain the motif. We conclude that instead of relying on a single motif finding tool, biologists should use a few complementary tools and pursue the top few predicted motifs of each.Computer Science Departmen

    The complex TIE between macrophages and angiogenesis

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    Macrophages are primarily known as phagocytic immune cells, but they also play a role in diverse processes, such as morphogenesis, homeostasis and regeneration. In this review, we discuss the influence of macrophages on angiogenesis, the process of new blood vessel formation from the pre-existing vasculature. Macrophages play crucial roles at each step of the angiogenic cascade, starting from new blood vessel sprouting to the remodelling of the vascular plexus and vessel maturation. Macrophages form promising targets for both pro- and anti-angiogenic treatments. However, to target macrophages, we will first need to understand the mechanisms that control the functional plasticity of macrophages during each of the steps of the angiogenic cascade. Here, we review recent insights in this topic. Special attention will be given to the TIE2-expressing macrophage (TEM), which is a subtype of highly angiogenic macrophages that is able to influence angiogenesis via the angiopoietin-TIE pathway

    Comparing early treatment outcomes of MDR-TB in a decentralised setting with a centralised setting in KwaZulu-Natal, South Africa.

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    Setting—In KwaZulu-Natal, South Africa, a TB and HIV endemic setting, prolonged hospitalisation for the treatment of the growing number of MDR-TB patients is not possible or effective. Objective—We compared early treatment outcomes in patients with MDR-TB, with and without HIV co infection, at a central, urban, referral hospital with four decentralised rural sites. Design—This is an operational, prospective cohort study of patients between 1 July 2008 to 30 November 2009, where culture conversion, time-to-culture-conversion, survival and predictors of these outcomes were analysed. Results—Of the 860 patients with MDR-TB, 419 were at the decentralised sites and 441 at the central hospital. Overall, 71% were HIV co-infected
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