239 research outputs found

    Magnetic Resonance Imaging of Pulmonary Lesions in Guinea Pigs Infected with Mycobacterium tuberculosis

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    We utilized magnetic resonance imaging to visualize lesions in the lungs of guinea pigs infected by low-dose aerosol exposure to Mycobacterium tuberculosis. Lesions were prominent in such images, and colorized three-dimensional reconstructions of images revealed a very uniform distribution in the lungs. Lesion numbers after 1 month were approximately similar to the aerosol exposure algorithm, suggesting that each was established by a single bacterium. Numbers of lesions in unprotected and vaccinated animals were similar over the first month but increased thereafter in the control animals, indicating secondary lesion development. Whereas lesion sizes increased progressively in control guinea pigs, lesions remained small in BCG-vaccinated animals. A prominent feature of the disease pathology in unprotected animals was rapid and severe lymphadenopathy of the mediastinal lymph node cluster, which is paradoxical given the strong state of cellular immunity at this time. Further development of this technical approach could be very useful in tracking lesion size, number, and progression in the search for new tuberculosis vaccines

    Regulatory T Cells in γ Irradiation-Induced Immune Suppression

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    Sublethal total body γ irradiation (TBI) of mammals causes generalized immunosuppression, in part by induction of lymphocyte apoptosis. Here, we provide evidence that a part of this immune suppression may be attributable to dysfunction of immune regulation. We investigated the effects of sublethal TBI on T cell memory responses to gain insight into the potential for loss of vaccine immunity following such exposure. We show that in mice primed to an MHC class I alloantigen, the accelerated graft rejection T memory response is specifically lost several weeks following TBI, whereas identically treated naïve mice at the same time point had completely recovered normal rejection kinetics. Depletion in vivo with anti-CD4 or anti-CD25 showed that the mechanism involved cells consistent with a regulatory T cell (T reg) phenotype. The loss of the T memory response following TBI was associated with a relative increase of CD4+CD25+ Foxp3+ expressing T regs, as compared to the CD8+ T effector cells requisite for skin graft rejection. The radiation-induced T memory suppression was shown to be antigen-specific in that a third party ipsilateral graft rejected with normal kinetics. Remarkably, following the eventual rejection of the first MHC class I disparate skin graft, the suppressive environment was maintained, with markedly prolonged survival of a second identical allograft. These findings have potential importance as regards the immunologic status of T memory responses in victims of ionizing radiation exposure and apoptosis-inducing therapies

    A randomized, double-blind, placebo-controlled trial of coenzyme Q10 in Huntington disease

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    Objective: To test the hypothesis that chronic treatment of early-stage Huntington disease (HD) with high-dose coenzyme Q10 (CoQ) will slow the progressive functional decline of HD. Methods: We performed a multicenter randomized, double-blind, placebo-controlled trial. Patients with early-stage HD (n = 609) were enrolled at 48 sites in the United States, Canada, and Australia from 2008 to 2012. Patients were randomized to receive either CoQ 2,400 mg/d or matching placebo, then followed for 60 months. The primary outcome variable was the change from baseline to month 60 in Total Functional Capacity score (for patients who survived) combined with time to death (for patients who died) analyzed using a joint-rank analysis approach. Results: An interim analysis for futility revealed a conditional power of <5% for the primary analysis, prompting premature conclusion in July 2014. No statistically significant differences were seen between treatment groups for the primary or secondary outcome measures. CoQ was generally safe and well-tolerated throughout the study. Conclusions: These data do not justify use of CoQ as a treatment to slow functional decline in HD

    Genes That Influence Swarming Motility and Biofilm Formation in Variovorax paradoxus EPS

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    Variovorax paradoxus is an aerobic soil bacterium associated with important biodegradative processes in nature. We use V. paradoxus EPS to study multicellular behaviors on surfaces.We recovered flanking sequence from 123 clones in a Tn5 mutant library, with insertions in 29 different genes, selected based on observed surface behavior phenotypes. We identified three genes, Varpa_4665, Varpa_4680, and Varpa_5900, for further examination. These genes were cloned into pBBR1MCS2 and used to complement the insertion mutants. We also analyzed expression of Varpa_4680 and Varpa_5900 under different growth conditions by qPCR.The 29 genes we identified had diverse predicted functions, many in exopolysaccharide synthesis. Varpa_4680, the most commonly recovered insertion site, encodes a putative N-acetyl-L-fucosamine transferase similar to WbuB. Expression of this gene in trans complemented the mutant fully. Several unique insertions were identified in Varpa_5900, which is one of three predicted pilY1 homologs in the EPS genome. No insertions in the two other putative pilY1 homologs present in the genome were identified. Expression of Varpa_5900 altered the structure of the wild type swarm, as did disruption of the chromosomal gene. The swarming phenotype was complemented by expression of Varpa_5900 from a plasmid, but biofilm formation was not restored. Both Varpa_4680 and Varpa_5900 transcripts were downregulated in biofilms and upregulated during swarming when compared to log phase culture. We identified a putative two component system (Varpa_4664-4665) encoding a response regulator (shkR) and a sensor histidine kinase (shkS), respectively. Biofilm formation increased and swarming was strongly delayed in the Varpa_4665 (shkS) mutant. Complementation of shkS restored the biofilm phenotype but swarming was still delayed. Expression of shkR in trans suppressed biofilm formation in either genetic background, and partially restored swarming in the mutant.The data presented here point to complex regulation of these surface behaviors

    Classifying the evolutionary and ecological features of neoplasms

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    The consensus conference was supported by Wellcome Genome Campus Advanced Courses and Scientific Conferences. C.C.M. is supported in part by US NIH grants P01 CA91955, R01 CA149566, R01 CA170595, R01 CA185138 and R01 CA140657 as well as CDMRP Breast Cancer Research Program Award BC132057. M.J. is supported by NIH grant K99CA201606. K.S.A. is supported by NCI 5R21 CA196460. K. Polyak is supported by R35 CA197623, U01 CA195469, U54 CA193461, and the Breast Cancer Research Foundation. K.J.P. is supported by NIH grants CA143803, CA163124, CA093900 and CA143055. D.P. is supported by the European Research Council (ERC-617457- PHYLOCANCER), the Spanish Ministry of Economy and Competitiveness (BFU2015-63774-P) and the Education, Culture and University Development Department of the Galician Government. K.S.A. is supported in part by the Breast Cancer Research Foundation and NCI R21CA196460. C.S. is supported by the Royal Society, Cancer Research UK (FC001169), the UK Medical Research Council (FC001169), and the Wellcome Trust (FC001169), NovoNordisk Foundation (ID 16584), the Breast Cancer Research Foundation (BCRF), the European Research Council (THESEUS) and Marie Curie Network PloidyNet. T.A.G. is a Cancer Research UK fellow and a Wellcome Trust funded Investigator. E.S.H. is supported by R01 CA185138-01 and W81XWH-14-1-0473. M.Gerlinger is supported by Cancer Research UK and The Royal Marsden/ICR National Institute of Health Research Biomedical Research Centre. M.Ge., M.Gr., Y.Y., and A.So. were also supported in part by the Wellcome Trust [105104/Z/14/Z]. J.D.S. holds the Edward B. Clark, MD Chair in Pediatric Research, and is supported by the Primary Children's Hospital (PCH) Pediatric Cancer Research Program, funded by the Intermountain Healthcare Foundation and the PCH Foundation. A.S. is supported by the Chris Rokos Fellowship in Evolution and Cancer. Y.Y. is a Cancer Research UK fellow and supported by The Royal Marsden/ICR National Institute of Health Research Biomedical Research Centre. E.S.H. was supported in part by PCORI grants 1505–30497 and 1503–29572, NIH grants R01 CA185138, T32 CA093245, and U10 CA180857, CDMRP Breast Cancer Research Program Award BC132057, a CRUK Grand Challenge grant, and the Breast Cancer Research Foundation. A.R.A.A. was funded in part by NIH grant U01CA151924. A.R.A.A., R.G. and J.S.B. were funded in part by NIH grant U54CA193489

    Assessing the microbiota of the snail intermediate host of trematodes, Galba truncatula

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    BackgroundThe microbiome is known to play key roles in health and disease, including host susceptibility to parasite infections. The freshwater snail Galba truncatula is the intermediate host for many trematode species, including the liver and rumen flukes Fasciola hepatica and Calicophoron daubneyi, respectively. The snail-parasite system has previously been investigated. However, the specific interaction between the snail-associated microbiota and intra-snail developmental stages of trematodes has yet to be explored.MethodsGalba truncatula snails were collected from farms in Northern Ireland and trematode infection was diagnosed using PCR. High-throughput sequencing analysis of the bacterial 16S ribosomal DNA V3-V4 hypervariable regions was subsequently applied to characterise the microbiota of both uninfected and infected snails.ResultsWe first showed that the snail harboured microbiota that was distinct for its environment. The microbiota of infected snails was found to differ significantly from that of uninfected snails. In particular, the bacterial genera Mycoplasma and Methylotenera were significantly more abundant in infected snails, while genera Sphingomonas and Nocardioides were predominantly associated with uninfected snails.ConclusionThese findings pave the way to future studies on the functional roles of bacteria in host-parasite relationships.<br/

    Visual sensitivities tuned by heterochronic shifts in opsin gene expression

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    Abstract Background Cichlid fishes have radiated into hundreds of species in the Great Lakes of Africa. Brightly colored males display on leks and vie to be chosen by females as mates. Strong discrimination by females causes differential male mating success, rapid evolution of male color patterns and, possibly, speciation. In addition to differences in color pattern, Lake Malawi cichlids also show some of the largest known shifts in visual sensitivity among closely related species. These shifts result from modulated expression of seven cone opsin genes. However, the mechanisms for this modulated expression are unknown. Results In this work, we ask whether these differences might result from changes in developmental patterning of cone opsin genes. To test this, we compared the developmental pattern of cone opsin gene expression of the Nile tilapia, Oreochromis niloticus, with that of several cichlid species from Lake Malawi. In tilapia, quantitative polymerase chain reaction showed that opsin gene expression changes dynamically from a larval gene set through a juvenile set to a final adult set. In contrast, Lake Malawi species showed one of two developmental patterns. In some species, the expressed gene set changes slowly, either retaining the larval pattern or progressing only from larval to juvenile gene sets (neoteny). In the other species, the same genes are expressed in both larvae and adults but correspond to the tilapia adult genes (direct development). Conclusion Differences in visual sensitivities among species of Lake Malawi cichlids arise through heterochronic shifts relative to the ontogenetic pattern of the tilapia outgroup. Heterochrony has previously been shown to be a powerful mechanism for change in morphological evolution. We found that altering developmental expression patterns is also an important mechanism for altering sensory systems. These resulting sensory shifts will have major impacts on visual communication and could help drive cichlid speciation.</p

    Spinocerebellar ataxia type 10 in Peru: the missing link in the Amerindian origin of the disease

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    Spinocerebellar ataxia type 10 (SCA10) is an autosomal dominant neurodegenerative disorder manifested by ataxia with a variable presentation of epileptic seizures, which is caused by a large expansion of an intronic ATTCT pentanucleotide repeat in ATXN10 on 22q13.3. Herein, we report the first description of SCA10 in a Peruvian family, supporting the Amerindian origin of SCA10 and the Panamerican geographical distribution of the disease in North, Central and South America. Moreover, the presence of an interruption motif in the SCA10 expansion along with epileptic seizures in this family supports the correlation between the two, as seen in other families. Finally, this is the first SCA10 patient ever observed outside of America, specifically in Italy. Since this patient is a Peruvian immigrant of Amerindian ancestry, our case report highlights the growing need for awareness amongst clinicians of seemingly geographically restricted rare diseases. © 2014 Springer-Verlag Berlin Heidelberg.Spinocerebellar ataxia type 10 (SCA10) is an autosomal dominant neurodegenerative disorder manifested by ataxia with a variable presentation of epileptic seizures, which is caused by a large expansion of an intronic ATTCT pentanucleotide repeat in ATXN10 on 22q13.3. Herein, we report the first description of SCA10 in a Peruvian family, supporting the Amerindian origin of SCA10 and the Panamerican geographical distribution of the disease in North, Central and South America. Moreover, the presence of an interruption motif in the SCA10 expansion along with epileptic seizures in this family supports the correlation between the two, as seen in other families. Finally, this is the first SCA10 patient ever observed outside of America, specifically in Italy. Since this patient is a Peruvian immigrant of Amerindian ancestry, our case report highlights the growing need for awareness amongst clinicians of seemingly geographically restricted rare diseases

    Inheritance patterns of ATCCT repeat interruptions in spinocerebellar ataxia type 10 (SCA10) expansions

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    <div><p>Spinocerebellar ataxia type 10 (SCA10), an autosomal dominant cerebellar ataxia disorder, is caused by a non-coding ATTCT microsatellite repeat expansion in the ataxin 10 gene. In a subset of SCA10 families, the 5’-end of the repeat expansion contains a complex sequence of penta- and heptanucleotide interruption motifs which is followed by a pure tract of tandem ATCCT repeats of unknown length at its 3’-end. Intriguingly, expansions that carry these interruption motifs correlate with an epileptic seizure phenotype and are unstable despite the theory that interruptions are expected to stabilize expanded repeats. To examine the apparent contradiction of unstable, interruption-positive SCA10 expansion alleles and to determine whether the instability originates outside of the interrupted region, we sequenced approximately 1 kb of the 5’-end of SCA10 expansions using the ATCCT-PCR product in individuals across multiple generations from four SCA10 families. We found that the greatest instability within this region occurred in paternal transmissions of the allele in stretches of pure ATTCT motifs while the intervening interrupted sequences were stable. Overall, the ATCCT interruption changes by only one to three repeat units and therefore cannot account for the instability across the length of the disease allele. We conclude that the AT-rich interruptions locally stabilize the SCA10 expansion at the 5’-end but do not completely abolish instability across the entire span of the expansion. In addition, analysis of the interruption alleles across these families support a parsimonious single origin of the mutation with a shared distant ancestor.</p></div
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