113 research outputs found
Planetary companions around the metal-poor star HIP 11952
Aims. We carried out a radial-velocity survey to search for planets around
metal-poor stars. In this paper we report the discovery of two planets around
HIP 11952, a metal-poor star with [Fe/H]= -1.9 that belongs to our target
sample. Methods. Radial velocity variations of HIP 11952 were monitored
systematically with FEROS at the 2.2 m telescope located at the ESO La Silla
observatory from August 2009 until January 2011. We used a cross-correlation
technique to measure the stellar radial velocities (RV). Results. We detected a
long-period RV variation of 290 d and a short-period one of 6.95 d. The
spectroscopic analysis of the stellar activity reveals a stellar rotation
period of 4.8 d. The Hipparcos photometry data shows intra-day variabilities,
which give evidence for stellar pulsations. Based on our analysis, the observed
RV variations are most likely caused by the presence of unseen planetary
companions. Assuming a primary mass of 0.83 M\odot, we computed minimum
planetary masses of 0.78 MJup for the inner and 2.93 MJup for the outer planet.
The semi-major axes are a1 = 0.07 AU and a2 = 0.81 AU, respectively.
Conclusions. HIP 11952 is one of very few stars with [Fe/H]< -1.0 which have
planetary companions. This discovery is important to understand planet
formation around metal-poor starsComment: Published in A&
Survival and health status of DOTS tuberculosis patients in rural Lao PDR
<p>Abstract</p> <p>Background</p> <p>Contact tracing of tuberculosis (TB) patients is rarely performed in low-income countries. Our objective was to assess the outcome of and compliance with directly observed treatment (DOTS) of TB patients over a 3 year period in rural Lao PDR.</p> <p>Methods</p> <p>We performed a retrospective cohort study in which we enrolled TB patients who started DOTS treatment at Attapeu Provincial Hospital. We traced, through hospital records, all patients in their residential village. We conducted a standardized questionnaire with all TB patients and performed physical and anthropometric examinations as well as evaluations of compliance through counting of treatment pills at home and at the health facilities.</p> <p>Results</p> <p>Of 172 enrolled TB patients (sex ratio female/male: 0.52, mean age: 46.9 years ± 16.9), 26 (15.1%) died. These had a lower weight at the start (34.6 <it>vs</it>. 40.8 kg, p < 0.001) and were less compliant (91.6% <it>vs</it>. 19.2%, p < 0.001) than survivors. Low compliance was associated with poor accessibility to health care (p = 0.01) and symptomatic improvement (p = 0.02). Survivors had persistently poor health status. They were underweight (54.7%), and still had clinical symptoms (53.5%), including dyspnoea (28.8%) and haemoptysis (9.5%).</p> <p>Conclusion</p> <p>Our study suggests a lower rate of survival than expected from official statistics. Additionally, it showed that follow-up of TB patients is feasible although the patients lived in very remote area of Laos. Follow-up should be strengthened as it can improve patient compliance, and allow contact tracing, detection of new cases and collection of accurate treatment outcome information.</p
Carboplatin-induced gene expression changes in vitro are prognostic of survival in epithelial ovarian cancer
<p>Abstract</p> <p>Background</p> <p>We performed a time-course microarray experiment to define the transcriptional response to carboplatin <it>in vitro</it>, and to correlate this with clinical outcome in epithelial ovarian cancer (EOC). RNA was isolated from carboplatin and control-treated 36M2 ovarian cancer cells at several time points, followed by oligonucleotide microarray hybridization. Carboplatin induced changes in gene expression were assessed at the single gene as well as at the pathway level. Clinical validation was performed in publicly available microarray datasets using disease free and overall survival endpoints.</p> <p>Results</p> <p>Time-course and pathway analyses identified 317 genes and 40 pathways (designated time-course and pathway signatures) deregulated following carboplatin exposure. Both types of signatures were validated in two separate platinum-treated ovarian and NSCLC cell lines using published microarray data. Expression of time-course and pathway signature genes distinguished between patients with unfavorable and favorable survival in two independent ovarian cancer datasets. Among the pathways most highly induced by carboplatin <it>in vitro</it>, the NRF2, NF-kB, and cytokine and inflammatory response pathways were also found to be upregulated prior to chemotherapy exposure in poor prognosis tumors.</p> <p>Conclusion</p> <p>Dynamic assessment of gene expression following carboplatin exposure <it>in vitro </it>can identify both genes and pathways that are correlated with clinical outcome. The functional relevance of this observation for better understanding the mechanisms of drug resistance in EOC will require further evaluation.</p
Monoamine related functional gene variants and relationships to monoamine metabolite concentrations in CSF of healthy volunteers
BACKGROUND: Concentrations of monoamine metabolites in human cerebrospinal fluid (CSF) have been used extensively as indirect estimates of monoamine turnover in the brain. CSF monoamine metabolite concentrations are partly determined by genetic influences. METHODS: We investigated possible relationships between DNA polymorphisms in the serotonin 2C receptor (HTR2C), the serotonin 3A receptor (HTR3A), the dopamine D(4 )receptor (DRD4), and the dopamine β-hydroxylase (DBH) genes and CSF concentrations of 5-hydroxyindolacetic acid (5-HIAA), homovanillic acid (HVA), and 3-methoxy-4-hydroxyphenylglycol (MHPG) in healthy volunteers (n = 90). RESULTS: The HTR3A 178 C/T variant was associated with 5-HIAA levels (p = 0.02). The DBH-1021 heterozygote genotype was associated with 5-HIAA (p = 0.0005) and HVA (p = 0.009) concentrations. Neither the HTR2C Cys23Ser variant, nor the DRD4 -521 C/T variant were significantly associated with any of the monoamine metabolites. CONCLUSIONS: The present results suggest that the HTR3A and DBH genes may participate in the regulation of dopamine and serotonin turnover rates in the central nervous system
Targeting of highly conserved Dengue virus sequences with anti-Dengue virus trans-splicing group I introns
<p>Abstract</p> <p>Background</p> <p>Dengue viruses (DENV) are one of the most important viral diseases in the world with approximately 100 million infections and 200,000 deaths each year. The current lack of an approved tetravalent vaccine and ineffective insecticide control measures warrant a search for alternatives to effectively combat DENV. The <it>trans</it>-splicing variant of the <it>Tetrahymena thermophila </it>group I intron catalytic RNA, or ribozyme, is a powerful tool for post-transcriptional RNA modification. The nature of the ribozyme and the predictability with which it can be directed makes it a powerful tool for modifying RNA in nearly any cell type without the need for genome-altering gene therapy techniques or dependence on native cofactors.</p> <p>Results</p> <p>Several anti-DENV Group I <it>trans</it>-splicing introns (αDENV-GrpIs) were designed and tested for their ability to target DENV-2 NGC genomes <it>in situ</it>. We have successfully targeted two different uracil bases on the positive sense genomic strand within the highly conserved 5'-3' cyclization sequence (CS) region common to all serotypes of DENV with our αDENV-GrpIs. Our ribozymes have demonstrated ability to specifically <it>trans</it>-splice a new RNA sequence downstream of the targeted site <it>in vitro </it>and in transfected insect cells as analyzed by firefly luciferase and RT-PCR assays. The effectiveness of these αDENV-GrpIs to target infecting DENV genomes is also validated in transfected or transformed Aedes mosquito cell lines upon infection with unattenuated DENV-2 NGC.</p> <p>Conclusions</p> <p>Analysis shows that our αDENV-GrpIs have the ability to effectively <it>trans</it>-splice the DENV genome <it>in situ</it>. Notably, these results show that the αDENV-GrpI 9v1, designed to be active against all forms of Dengue virus, effectively targeted the DENV-2 NGC genome in a sequence specific manner. These novel αDENV-GrpI introns provide a striking alternative to other RNA based approaches for the transgenic suppression of DENV in transformed mosquito cells and tissues.</p
Why NS and BH mass distribition is bimodal?
The observed mass distribution for the compact remnants of massive stars
(neutron stars and black holes) and its relationship to possible mechanisms for
the ejection of the envelopes of type II and Ib/c supernovae is analyzed. The
conclusion is drawn that this distribution can be obtained only by a
magneto-rotational mechanism for the supernovae with sufficiently long time of
the field amplification, and a soft equation of state for neutron stars with
limiting masses \sim1.5-1.6M_\odot. Some consequences of this hypothesis are
discussed.Comment: latex, 4 pages, 5 figures, Talk given at 5th Int. Tsessevich Conf.
"Variable Stars", Odessa, Ukraine, August 200
Measuring the Willingness to Pay to Avoid Guilt: Estimation Using Equilibrium and Stated Belief Models
Analysis of single nucleotide polymorphisms in the FAS and CTLA-4 genes of peripheral T-cell lymphomas
Angioimmunoblastic T-cell lymphoma (AILT) represents a subset of T-cell lymphomas but resembles an autoimmune disease in many of its clinical aspects. Despite the phenotype of effector T-cells and high expression of FAS and CTLA-4 receptor molecules, tumor cells fail to undergo apoptosis. We investigated single nucleotide polymorphisms (SNPs) of the FAS and CTLA-4 genes in 94 peripheral T-cell lymphomas. Although allelic frequencies of some FAS SNPs were enriched in AILT cases, none of these occurred at a different frequency compared to healthy individuals. Therefore, SNPs in these genes are not associated with the apoptotic defect and autoimmune phenomena in AILT
Estimates of new and total productivity in central Long Island Sound from in situ measurements of nitrate and dissolved oxygen
Author Posting. © The Author(s), 2013. This is the author's version of the work. It is posted here by permission of Springer for personal use, not for redistribution. The definitive version was published in Estuaries and Coasts 36 (2013): 74-97, doi:10.1007/s12237-012-9560-5.Biogeochemical cycles in estuaries are regulated by a diverse set of physical and
biological variables that operate over a variety of time scales. Using in situ optical sensors, we
conducted a high-frequency time-series study of several biogeochemical parameters at a mooring
in central Long Island Sound from May to August 2010. During this period, we documented
well-defined diel cycles in nitrate concentration that were correlated to dissolved oxygen, wind
stress, tidal mixing, and irradiance. By filtering the data to separate the nitrate time series into
various signal components, we estimated the amount of variation that could be ascribed to each
process. Primary production and surface wind stress explained 59% and 19%, respectively, of the
variation in nitrate concentrations. Less frequent physical forcings, including large-magnitude wind events and spring tides, served to decouple the relationship between oxygen, nitrate, and
sunlight on about one-quarter of study days. Daytime nitrate minima and dissolved oxygen
maxima occurred nearly simultaneously on the majority (> 80%) of days during the study period;
both were strongly correlated with the daily peak in irradiance. Nighttime nitrate maxima
reflected a pattern in which surface-layer stocks were depleted each afternoon and recharged the
following night. Changes in nitrate concentrations were used to generate daily estimates of new
primary production (182 ± 37 mg C m-2 d-1) and the f-ratio (0.25), i.e., the ratio of production
based on nitrate to total production. These estimates, the first of their kind in Long Island Sound,
were compared to values of community respiration, primary productivity, and net ecosystem
metabolism, which were derived from in situ measurements of oxygen concentration. Daily
averages of the three metabolic parameters were 1660 ± 431, 2080 ± 419, and 429 ± 203 mg C
m-2 d-1, respectively. While the system remained weakly autotrophic over the duration of the
study period, we observed very large day-to-day differences in the f-ratio and in the various
metabolic parameters.This work was supported by the Yale
Institute for Biospheric Studies, the Sounds Conservancy of the Quebec-Labrador Foundation,
and the Yale School of Forestry and Environmental Studies Carpenter-Sperry Fund.2014-01-0
On the Dark Side of Therapies with Immunoglobulin Concentrates: The Adverse Events
Therapy by human immunoglobulin G (IgG) concentrates is a success story ongoing for decades with an ever increasing demand for this plasma product. The success of IgG concentrates on a clinical level is documented by the slowly increasing number of registered indication and the more rapid increase of the off-label uses, a topic dealt with in another contribution to this special issue of Frontiers in Immunology. A part of the success is the adverse event (AE) profile of IgG concentrates which is, even at life-long need for therapy, excellent. Transmission of pathogens in the last decade could be entirely controlled through the antecedent introduction by authorities of a regulatory network and installing quality standards by the plasma fractionation industry. The cornerstone of the regulatory network is current good manufacturing practice. Non-infectious AEs occur rarely and mainly are mild to moderate. However, in recent times, the increase in frequency of hemolytic and thrombotic AEs raised worrying questions on the possible background for these AEs. Below, we review elements of non-infectious AEs, and particularly focus on hemolysis and thrombosis. We discuss how the introduction of plasma fractionation by ion-exchange chromatography and polishing by immunoaffinity chromatographic steps might alter repertoire of specificities and influence AE profiles and efficacy of IgG concentrates
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