1,167 research outputs found

    Expanding the Entamoeba Universe: New Hosts Yield Novel Ribosomal Lineages.

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    Removing the requirement for cell culture has led to a substantial increase in the number of lineages of Entamoeba recognized as distinct. Surveying the range of potential host species for this parasite genus has barely been started and it is clear that additional sampling of the same host in different locations often identifies additional diversity. In this study, using small subunit ribosomal RNA gene sequencing, we identify four new lineages of Entamoeba, including the first report of Entamoeba from an elephant, and extend the host range of some previously described lineages. In addition, examination of microbiome data from a number of host animals suggests that substantial Entamoeba diversity remains to be uncovered

    Anionic Magnesium and Calcium Hydrides : Transforming CO into Unsaturated Disilyl Ethers

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    OA-artikkeli, mutta ladattaessa tulee hieman erinäköinen versio (esim. ei lisenssiä). Tallennettu kuitenkin OA-artikkelina.The synthesis, characterisation and reactivity of two isostructural anionic magnesium and calcium complexes is reported. By X-ray and neutron diffraction techniques, the anionic hydrides are shown to exist as dimers, held together by a range of interactions between the two anions and two bridging potassium cations. Unlike the vast proportion of previously reported dimeric group 2 hydrides, which have hydrides that bridge two group 2 centres, here the hydrides are shown to be “terminal”, but stabilised by interactions with the potassium cations. Both anionic hydrides were found to insert and couple CO under mild reaction conditions to give the corresponding group 2 cis-ethenediolate complexes. These cis-ethenediolate complexes were found to undergo salt elimination reactions with silyl chlorides, allowing access to small unsaturated disilyl ethers with a high percentage of their mass originating from the C1 source CO.Peer reviewe

    Anthracenyl isoxazole amides (AIMs) stabilize quadruplex DNA structures in telomeric and c-MYC promotor sequences

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    Approximately 23,000 people are affected by malignant brain and CNS tumors in the United States each year and those afflicted have a median survival rate of only 12–15 months due to the limited treatment options available. The anthracenyl isoxazole amides (AIMs) are a novel class of compounds that have been shown to possess significant anti tumor activity in the NCI 60 cell line panel and to inhibit growth of SNB-19 glioblastoma cells at low micromolar and nanomolar concentrations. The goal of our current research is to characterize the mechanism underlying the anti tumor activity of the AIMs. We hypothesize the mechanism of growth inhibition to involve binding and stabilization of a DNA tertiary structure known as a guanine quadruplex. Various regulatory regions of DNA, such the c-MYC oncogene promoter sequence and repeating sequences formed at the end of telomeres, adopt the quadruplex conformation. Stabilization of quadruplex structures by small-molecule binding ligands has been reported to modulate the expression of genes and inhibit telomerase activity. Down-regulation of certain oncogenes or the inhibition of telomerase can cause tumor cells to undergo apoptosis or become unable to efficiently replicate. To establish whether interactions between the AIMs and quadruplex-forming sequences act to stabilize the quadruplex tertiary structure, circular dichroism spectroscopy (CD) was employed. CD is a method that utilizes the differential absorbance of left and right circularly polarized light to examine the chiral structure of molecules. CD thermal melting studies were conducted to determine whether the AIMs would increase the melting temperature of quadruplex forming sequences as an indication of increased stability. Our results demonstrated the AIMs, at two equivalents, increase the melting temperature (Tm) of both the c-MYC promoter and telomeric sequences by approximately 2–3 °C with strong statistical significance and reproducibility. Utilizing CD allows the use of low micromolar concentrations of DNA and this method will be used in the future to rapidly develop additional structure-activity relationships between novel AIMs and quadruplex forming sequences. Our laboratory has also shown chemical shifts in the imino region upon treatment with the AIMs for both the c-MYC promotor and telomeric sequence by NMR, providing additional evidence of the AIMs interaction with quadruplex structures. Interestingly, fluorescence microscopy of SNB-19 cells treated with AIMs show their localization is primarily in the mitochondria, and mitochondrial DNA contains several other important quadruplex forming sequences. Mitochondrial-dependent apoptosis has been suggested for other quadruplex binding ligands and therefore our future work will examine the potential stabilization of mitochondrial quadruplexes by these and other novel AIMs

    Genetic diversity of blastocystis in livestock and zoo animals.

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    Blastocystis is a common unicellular anaerobic eukaryote that inhabits the large intestine of many animals worldwide, including humans. The finding of Blastocystis in faeces in mammals and birds has led to proposals of zoonotic potential and that these hosts may be the source of many human infections. Blastocystis is, however, a genetically diverse complex of many distinct organisms (termed subtypes; STs), and sampling to date has been limited, both geographically and in the range of hosts studied. In order to expand our understanding of host specificity of Blastocystis STs, 557 samples were examined from various non-primate animal hosts and from a variety of different countries in Africa, Asia and Europe. STs were identified using 'barcoding' of the small subunit rRNA gene using DNA extracted either from culture or directly from faeces. The host and geographic range of several STs has thereby been greatly expanded and the evidence suggests that livestock is not a major contributor to human infection. Two new STs were detected among the barcode sequences obtained; for these, and for three others where the data were incomplete, the corresponding genes were fully sequenced and phylogenetic analysis was undertaken

    Blastocystis Mitochondrial Genomes Appear to Show Multiple Independent Gains and Losses of Start and Stop Codons.

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    Complete mitochondrion-related organelle (MRO) genomes of several subtypes (STs) of the unicellular stramenopile Blastocystis are presented. Complete conservation of gene content and synteny in gene order is observed across all MRO genomes, comprising 27 protein coding genes, 2 ribosomal RNA genes, and 16 transfer RNA (tRNA) genes. Despite the synteny, differences in the degree of overlap between genes were observed between subtypes and also between isolates within the same subtype. Other notable features include unusual base-pairing mismatches in the predicted secondary structures of some tRNAs. Intriguingly, the rps4 gene in some MRO genomes is missing a start codon and, based on phylogenetic relationships among STs, this loss has happened twice independently. One unidentified open reading frame (orf160) is present in all MRO genomes. However, with the exception of ST4 where the feature has been lost secondarily, orf160 contains variously one or two in-frame stop codons. The overall evidence suggests that both the orf160 and rps4 genes are functional in all STs, but how they are expressed remains unclear

    First observations with SuperCam and future plans

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    Supercam is a 345 GHz, 64-pixel heterodyne imaging array for the Heinrich Hertz Submillimeter Telescope (HHSMT). By integrating SIS mixer devices with Low Noise Ampliers (LNAs) in 8 - 1x8 pixel modules, the size needed for the cryostat and the complexity of internal wiring is signicantly reduced. All subsystems including the optics, cryostat, bias system, IF boxes, and spectrometer have been integrated for all 64 pixels. In the spring of 2012, SuperCam was installed on the HHSMT for an engineering run where it underwent system level tests and performed rst light observations. In the fall of 2012 SuperCam will begin a 500 square degree survey of the Galactic Plane in ^(12)CO J=3-2. This large-scale survey will help answer fundamental questions about the formation, physical conditions, and energetics of molecular clouds within the Milky Way. The data set will be available via the web to all interested researchers

    British Lung Foundation/United Kingdom primary immunodeficiency network consensus statement on the definition, diagnosis, and management of granulomatous-lymphocytic interstitial lung disease in common variable immunodeficiency disorders

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    A proportion of people living with common variable immunodeficiency disorders develop granulomatous-lymphocytic interstitial lung disease (GLILD). We aimed to develop a consensus statement on the definition, diagnosis, and management of GLILD. All UK specialist centers were contacted and relevant physicians were invited to take part in a 3-round online Delphi process. Responses were graded as Strongly Agree, Tend to Agree, Neither Agree nor Disagree, Tend to Disagree, and Strongly Disagree, scored +1, +0.5, 0, −0.5, and −1, respectively. Agreement was defined as greater than or equal to 80% consensus. Scores are reported as mean ± SD. There was 100% agreement (score, 0.92 ± 0.19) for the following definition: “GLILD is a distinct clinico-radio-pathological ILD occurring in patients with [common variable immunodeficiency disorders], associated with a lymphocytic infiltrate and/or granuloma in the lung, and in whom other conditions have been considered and where possible excluded.” There was consensus that the workup of suspected GLILD requires chest computed tomography (CT) (0.98 ± 0.01), lung function tests (eg, gas transfer, 0.94 ± 0.17), bronchoscopy to exclude infection (0.63 ± 0.50), and lung biopsy (0.58 ± 0.40). There was no consensus on whether expectant management following optimization of immunoglobulin therapy was acceptable: 67% agreed, 25% disagreed, score 0.38 ± 0.59; 90% agreed that when treatment was required, first-line treatment should be with corticosteroids alone (score, 0.55 ± 0.51)

    Multi-centre parallel arm randomised controlled trial to assess the effectiveness and cost-effectiveness of a group-based cognitive behavioural approach to managing fatigue in people with multiple sclerosis

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    Abstract (provisional) Background Fatigue is one of the most commonly reported and debilitating symptoms of multiple sclerosis (MS); approximately two-thirds of people with MS consider it to be one of their three most troubling symptoms. It may limit or prevent participation in everyday activities, work, leisure, and social pursuits, reduce psychological well-being and is one of the key precipitants of early retirement. Energy effectiveness approaches have been shown to be effective in reducing MS-fatigue, increasing self-efficacy and improving quality of life. Cognitive behavioural approaches have been found to be effective for managing fatigue in other conditions, such as chronic fatigue syndrome, and more recently, in MS. The aim of this pragmatic trial is to evaluate the clinical and cost-effectiveness of a recently developed group-based fatigue management intervention (that blends cognitive behavioural and energy effectiveness approaches) compared with current local practice. Methods This is a multi-centre parallel arm block-randomised controlled trial (RCT) of a six session group-based fatigue management intervention, delivered by health professionals, compared with current local practice. 180 consenting adults with a confirmed diagnosis of MS and significant fatigue levels, recruited via secondary/primary care or newsletters/websites, will be randomised to receive the fatigue management intervention or current local practice. An economic evaluation will be undertaken alongside the trial. Primary outcomes are fatigue severity, self-efficacy and disease-specific quality of life. Secondary outcomes include fatigue impact, general quality of life, mood, activity patterns, and cost-effectiveness. Outcomes in those receiving the fatigue management intervention will be measured 1 week prior to, and 1, 4, and 12 months after the intervention (and at equivalent times in those receiving current local practice). A qualitative component will examine what aspects of the fatigue management intervention participants found helpful/unhelpful and barriers to change. Discussion This trial is the fourth stage of a research programme that has followed the Medical Research Council guidance for developing and evaluating complex interventions. What makes the intervention unique is that it blends cognitive behavioural and energy effectiveness approaches. A potential strength of the intervention is that it could be integrated into existing service delivery models as it has been designed to be delivered by staff already working with people with MS. Service users will be involved throughout this research. Trial registration: Current Controlled Trials ISRCTN7651747
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