429 research outputs found
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Global transcription of CRISPR loci in the human oral cavity
© 2015 Lum et al.; licensee BioMed Central. Background: Clustered Regularly Interspaced Short Palindromic Repeats (CRISPRs) are active in acquired resistance against bacteriophage and plasmids in a number of environments. In the human mouth, CRISPR loci evolve to counteract oral phage, but the expression of these CRISPR loci has not previously been investigated. We sequenced cDNA from CRISPR loci found in numerous different oral bacteria and compared with oral phage communities to determine whether the transcription of CRISPR loci is specifically targeted towards highly abundant phage present in the oral environment. Results: We found that of the 529,027 CRISPR spacer groups studied, 88 % could be identified in transcripts, indicating that the vast majority of CRISPR loci in the oral cavity were transcribed. There were no strong associations between CRISPR spacer repertoires and oral health status or nucleic acid type. We also compared CRISPR repertoires with oral bacteriophage communities, and found that there was no significant association between CRISPR transcripts and oral phage, regardless of the CRISPR type being evaluated. We characterized highly expressed CRISPR spacers and found that they were no more likely than other spacers to match oral phage. By reassembling the CRISPR-bearing reads into longer CRISPR loci, we found that the majority of the loci did not have spacers matching viruses found in the oral cavities of the subjects studied. For some CRISPR types, loci containing spacers matching oral phage were significantly more likely to have multiple spacers rather than a single spacer matching oral phage. Conclusions: These data suggest that the transcription of oral CRISPR loci is relatively ubiquitous and that highly expressed CRISPR spacers do not necessarily target the most abundant oral phage
Insulin autoantibodies as determined by competitive radiobinding assay are positively correlated with impaired beta-cell function — The Ulm-Frankfurt population study
Out of a random population of 4208 non-diabetic pupils without a family history of Type I diabetes 44 (1.05%) individuals had islet cell antibody (ICA) levels greater or equal to 5 Juvenile Diabetes Foundation (JDF) units. 39 of these ICA-positives could be repeatedly tested for circulating insulin autoantibodies (CIAA) using a competitive radiobinding assay. The results were compared with the insulin responses in the intravenous glucose tolerance tests (IVGTT) and with HLA types. Six pupils were positive for CIAA. All of them had complement-fixing ICA, and 5 of them were HLA-DR4 positive. Three of the 6 showed a first-phase insulin response below the first percentile of normal controls. Our data indicate that in population-based studies CIAA can be considered as a high risk marker for impaired beta-cell function in non-diabetic ICA-positive individuals
Antibodies to the Mr 64,000 (64K) protein in islet cell antibody positive non-diabetic individuals indicate high risk for impaired Beta-cell function
A prospective study of a normal childhood population identified 44 islet cell antibody positive individuals. These subjects were typed for HLA DR and DQ alleles and investigated for the presence of antibodies to the Mr 64,000 (64K) islet cell antigen, complement-fixing islet cell antibodies and radiobinding insulin autoantibodies to determine their potency in detecting subjects with impaired Beta-cell function. At initial testing 64K antibodies were found in six of 44 islet cell antibody positive subjects (13.6%). The same sera were also positive for complement-fixing islet cell antibodies and five of them had insulin autoantibodies. During the follow-up at 18 months, islet cell antibodies remained detectable in 50% of the subjects studied. In all six cases who were originally positive, 64K antibodies were persistently detectable, whereas complement-fixing islet cell antibodies became negative in two of six and insulin autoantibodies in one of five individuals. HLA DR4 (p < 0.005) and absence of asparic acid (Asp) at position 57 of the HLA DQ chain (p < 0.05) were significantly increased in subjects with 64K antibodies compared with control subjects. Of 40 individuals tested in the intravenous glucose tolerance test, three had a first phase insulin response below the first percentile of normal control subjects. Two children developed Type 1 (insulin-dependent) diabetes mellitus after 18 and 26 months, respectively. Each of these subjects was non-Asp homozygous and had persistent islet cell and 64K antibodies. We conclude that 64K antibodies, complement-fixing islet cell antibodies and insulin autoantibodies represent sensitive serological markers in assessing high risk for a progression to Type 1 diabetes in islet cell antibody positive non-diabetic individuals
A Mathematical model for Astrocytes mediated LTP at Single Hippocampal Synapses
Many contemporary studies have shown that astrocytes play a significant role
in modulating both short and long form of synaptic plasticity. There are very
few experimental models which elucidate the role of astrocyte over Long-term
Potentiation (LTP). Recently, Perea & Araque (2007) demonstrated a role of
astrocytes in induction of LTP at single hippocampal synapses. They suggested a
purely pre-synaptic basis for induction of this N-methyl-D- Aspartate (NMDA)
Receptor-independent LTP. Also, the mechanisms underlying this pre-synaptic
induction were not investigated. Here, in this article, we propose a
mathematical model for astrocyte modulated LTP which successfully emulates the
experimental findings of Perea & Araque (2007). Our study suggests the role of
retrograde messengers, possibly Nitric Oxide (NO), for this pre-synaptically
modulated LTP.Comment: 51 pages, 15 figures, Journal of Computational Neuroscience (to
appear
Probing natural SUSY from stop pair production at the LHC
We consider the natural supersymmetry scenario in the framework of the
R-parity conserving minimal supersymmetric standard model (called natural MSSM)
and examine the observability of stop pair production at the LHC. We first scan
the parameters of this scenario under various experimental constraints,
including the SM-like Higgs boson mass, the indirect limits from precision
electroweak data and B-decays. Then in the allowed parameter space we study the
stop pair production at the LHC followed by the stop decay into a top quark
plus a lightest neutralino or into a bottom quark plus a chargino. From
detailed Monte Carlo simulations of the signals and backgrounds, we find the
two decay modes are complementary to each other in probing the stop pair
production, and the LHC with TeV and 100 luminosity is
capable of discovering the stop predicted in natural MSSM up to 450 GeV. If no
excess events were observed at the LHC, the 95% C.L. exclusion limits of the
stop masses can reach around 537 GeV.Comment: 19 pages, 10 figures, version accepted by JHE
Consumer satisfaction with primary care provider choice and associated trust
BACKGROUND: Development of managed care, characterized by limited provider choice, is believed to undermine trust. Provider choice has been identified as strongly associated with physician trust. Stakeholders in a competitive healthcare market have competing agendas related to choice. The purpose of this study is to analyze variables associated with consumer's satisfaction that they have enough choice when selecting their primary care provider (PCP), and to analyze the importance of these variables on provider trust. METHODS: A 1999 randomized national cross-sectional telephone survey conducted of United States residential households, who had a telephone, had seen a medical professional at least twice in the past two years, and aged ≥ 20 years was selected for secondary data analyses. Among 1,117 households interviewed, 564 were selected as the final sample. Subjects responded to a core set of questions related to provider trust, and a subset of questions related to trust in the insurer. A previously developed conceptual framework was adopted. Linear and logistic regressions were performed based on this framework. RESULTS: Results affirmed 'satisfaction with amount of PCP choice' was significantly (p < .001) associated with provider trust. 'PCP's care being extremely effective' was strongly associated with 'satisfaction with amount of PCP choice' and 'provider trust'. Having sought a second opinion(s) was associated with lower trust. 'Spoke to the PCP outside the medical office,' 'satisfaction with the insurer' and 'insurer charges less if PCP within network' were all variables associated with 'satisfaction with amount of PCP choice' (all p < .05). CONCLUSION: This study confirmed the association of 'satisfaction with amount of PCP choice' with provider trust. Results affirmed 'enough PCP choice' was a strong predictor of provider trust. 'Second opinion on PCP' may indicate distrust in the provider. Data such as 'trust in providers in general' and 'the role of provider performance information' in choice, though import in PCP choice, were not available for analysis and should be explored in future studies. Results have implications for rethinking the relationships among consumer choice, consumer behaviors in making trade-offs in PCP choice, and the role of healthcare experiences in 'satisfaction with amount of PCP choice' or 'provider trust.
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High-potency ligands for DREADD imaging and activation in rodents and monkeys.
Designer Receptors Exclusively Activated by Designer Drugs (DREADDs) are a popular chemogenetic technology for manipulation of neuronal activity in uninstrumented awake animals with potential for human applications as well. The prototypical DREADD agonist clozapine N-oxide (CNO) lacks brain entry and converts to clozapine, making it difficult to apply in basic and translational applications. Here we report the development of two novel DREADD agonists, JHU37152 and JHU37160, and the first dedicated 18F positron emission tomography (PET) DREADD radiotracer, [18F]JHU37107. We show that JHU37152 and JHU37160 exhibit high in vivo DREADD potency. [18F]JHU37107 combined with PET allows for DREADD detection in locally-targeted neurons, and at their long-range projections, enabling noninvasive and longitudinal neuronal projection mapping
Genetically-Based Olfactory Signatures Persist Despite Dietary Variation
Individual mice have a unique odor, or odortype, that facilitates individual recognition. Odortypes, like other phenotypes, can be influenced by genetic and environmental variation. The genetic influence derives in part from genes of the major histocompatibility complex (MHC). A major environmental influence is diet, which could obscure the genetic contribution to odortype. Because odortype stability is a prerequisite for individual recognition under normal behavioral conditions, we investigated whether MHC-determined urinary odortypes of inbred mice can be identified in the face of large diet-induced variation. Mice trained to discriminate urines from panels of mice that differed both in diet and MHC type found the diet odor more salient in generalization trials. Nevertheless, when mice were trained to discriminate mice with only MHC differences (but on the same diet), they recognized the MHC difference when tested with urines from mice on a different diet. This indicates that MHC odor profiles remain despite large dietary variation. Chemical analyses of urinary volatile organic compounds (VOCs) extracted by solid phase microextraction (SPME) and analyzed by gas chromatography/mass spectrometry (GC/MS) are consistent with this inference. Although diet influenced VOC variation more than MHC, with algorithmic training (supervised classification) MHC types could be accurately discriminated across different diets. Thus, although there are clear diet effects on urinary volatile profiles, they do not obscure MHC effects
Cyclic di-GMP is Essential for the Survival of the Lyme Disease Spirochete in Ticks
Cyclic dimeric GMP (c-di-GMP) is a bacterial second messenger that modulates many biological processes. Although its role in bacterial pathogenesis during mammalian infection has been documented, the role of c-di-GMP in a pathogen's life cycle within a vector host is less understood. The enzootic cycle of the Lyme disease pathogen Borrelia burgdorferi involves both a mammalian host and an Ixodes tick vector. The B. burgdorferi genome encodes a single copy of the diguanylate cyclase gene (rrp1), which is responsible for c-di-GMP synthesis. To determine the role of c-di-GMP in the life cycle of B. burgdorferi, an Rrp1-deficient B. burgdorferi strain was generated. The rrp1 mutant remains infectious in the mammalian host but cannot survive in the tick vector. Microarray analyses revealed that expression of a four-gene operon involved in glycerol transport and metabolism, bb0240-bb0243, was significantly downregulated by abrogation of Rrp1. In vitro, the rrp1 mutant is impaired in growth in the media containing glycerol as the carbon source (BSK-glycerol). To determine the contribution of the glycerol metabolic pathway to the rrp1 mutant phenotype, a glp mutant, in which the entire bb0240-bb0243 operon is not expressed, was generated. Similar to the rrp1 mutant, the glp mutant has a growth defect in BSK-glycerol medium. In vivo, the glp mutant is also infectious in mice but has reduced survival in ticks. Constitutive expression of the bb0240-bb0243 operon in the rrp1 mutant fully rescues the growth defect in BSK-glycerol medium and partially restores survival of the rrp1 mutant in ticks. Thus, c-di-GMP appears to govern a catabolic switch in B. burgdorferi and plays a vital role in the tick part of the spirochetal enzootic cycle. This work provides the first evidence that c-di-GMP is essential for a pathogen's survival in its vector host
Fetal Movement Counting Improved Identification of Fetal Growth Restriction and Perinatal Outcomes – a Multi-Centre, Randomized, Controlled Trial
Background
Fetal movement counting is a method used by the mother to quantify her baby's movements, and may prevent adverse pregnancy outcome by a timely evaluation of fetal health when the woman reports decreased fetal movements. We aimed to assess effects of fetal movement counting on identification of fetal pathology and pregnancy outcome.
Methodology
In a multicentre, randomized, controlled trial, 1076 pregnant women with singleton pregnancies from an unselected population were assigned to either perform fetal movement counting from gestational week 28, or to receive standard antenatal care not including fetal movement counting (controls). Women were recruited from nine Norwegian hospitals during September 2007 through November 2009. Main outcome was a compound measure of fetal pathology and adverse pregnancy outcomes. Analysis was performed by intention-to-treat.
Principal Findings
The frequency of the main outcome was equal in the groups; 63 of 433 (11.6%) in the intervention group, versus 53 of 532 (10.7%) in the control group [RR: 1.1 95% CI 0.7–1.5)]. The growth-restricted fetuses were more often identified prior to birth in the intervention group than in the control group; 20 of 23 fetuses (87.0%) versus 12 of 20 fetuses (60.0%), respectively, [RR: 1.5 (95% CI 1.0–2.1)]. In the intervention group two babies (0.4%) had Apgar scores <4 at 1 minute, versus 12 (2.3%) in the control group [RR: 0.2 (95% CI 0.04–0.7)]. The frequency of consultations for decreased fetal movement was 71 (13.1%) and 57 (10.7%) in the intervention and control groups, respectively [RR: 1.2 (95% CI 0.9–1.7)]. The frequency of interventions was similar in the groups.
Conclusions
Maternal ability to detect clinically important changes in fetal activity seemed to be improved by fetal movement counting; there was an increased identification of fetal growth restriction and improved perinatal outcome, without inducing more consultations or obstetric intervention
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