432 research outputs found

    Hemodynamic and anti-inflammatory effects of early esmolol use in hyperkinetic septic shock. a pilot study

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    Background: Several studies have shown that heart rate control with selective beta-1 blockers in septic shock is safe. In these trials, esmolol was administered 24 h after onset of septic shock in patients who remained tachycardic. While an earlier use of beta-blockers might be beneficial, such use remains challenging due to the difficulty in distinguishing between compensatory and non-compensatory tachycardia. Therefore, the Esmosepsis study was designed to study the effects of esmolol aimed at reducing the heart rate by 20% after the initial resuscitation process in hyperkinetic septic shock patients on (1) cardiac index and (2) systemic and regional hemodynamics as well as inflammatory patterns. Methods: Nine consecutive stabilized tachycardic hyperkinetic septic shock patients treated with norepinephrine for a minimum of 6 h were included. Esmolol was infused during 6 h in order to decrease the heart rate by 20%. The following data were recorded at hours H0 (before esmolol administration), H1–H6 (esmolol administration) and 1 h after esmolol cessation (H7): systolic arterial pressure, diastolic arterial pressure, mean arterial pressure, central venous pressure, heart rate, PICCO transpulmonary thermodilution, sublingual and musculo-cutaneous microcirculation, indocyanine green clearance and echocardiographic parameters, diuresis, lactate, and arterial and venous blood gases. Results: Esmolol was infused 9 (6.4–11.6) hours after norepinephrine introduction. Esmolol was ceased early in 3 out of 9 patients due to a marked increase in norepinephrine requirement associated with a picture of persistent cardiac failure at the lowest esmolol dose. For the global group, during esmolol infusion, norepinephrine infusion increased from 0.49 (0.34–0.83) to 0.78 (0.3–1.11) µg/min/kg. The use of esmolol was associated with a significant decrease in heart rate from 115 (110–125) to 100 (92–103) beats/min and a decrease in cardiac index from 4.2 (3.1–4.4) to 2.9 (2.5–3.7) l/min/m−2. Indexed stroke volume remained unchanged. Cardiac function index and global ejection fraction also markedly decreased. Using echocardiography, systolic, diastolic as well as left and right ventricular function parameters worsened. After esmolol cessation, all parameters returned to baseline values. Lactate and microcirculatory parameters did not change while the majority of pro-inflammatory proteins decreased in all patients. Conclusion: In the very early phase of septic shock, heart rate reduction using fast esmolol titration is associated with an increased risk of hypotension and decreased cardiac index despite maintained adequate tissue perfusion (NCT02068287)

    The Vaginal Microbiome: Disease, Genetics and the Environment

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    The vagina is an interactive interface between the host and the environment. Its surface is covered by a protective epithelium colonized by bacteria and other microorganisms. The ectocervix is nonsterile, whereas the endocervix and the upper genital tract are assumed to be sterile in healthy women. Therefore, the cervix serves a pivotal role as a gatekeeper to protect the upper genital tract from microbial invasion and subsequent reproductive pathology. Microorganisms that cross this barrier can cause preterm labor, pelvic inflammatory disease, and other gynecologic and reproductive disorders. Homeostasis of the microbiome in the vagina and ectocervix plays a paramount role in reproductive health. Depending on its composition, the microbiome may protect the vagina from infectious or non-infectious diseases, or it may enhance its susceptibility to them. Because of the nature of this organ, and the fact that it is continuously colonized by bacteria from birth to death, it is virtually certain that this rich environment evolved in concert with its microbial flora. Specific interactions dictated by the genetics of both the host and microbes are likely responsible for maintaining both the environment and the microbiome. However, the genetic basis of these interactions in both the host and the bacterial colonizers is currently unknown. _Lactobacillus_ species are associated with vaginal health, but the role of these species in the maintenance of health is not yet well defined. Similarly, other species, including those representing minor components of the overall flora, undoubtedly influence the ability of potential pathogens to thrive and cause disease. Gross alterations in the vaginal microbiome are frequently observed in women with bacterial vaginosis, but the exact etiology of this disorder is still unknown. There are also implications for vaginal flora in non-infectious conditions such as pregnancy, pre-term labor and birth, and possibly fertility and other aspects of women’s health. Conversely, the role of environmental factors in the maintenance of a healthy vaginal microbiome is largely unknown. To explore these issues, we have proposed to address the following questions:

*1.	Do the genes of the host contribute to the composition of the vaginal microbiome?* We hypothesize that genes of both host and bacteria have important impacts on the vaginal microbiome. We are addressing this question by examining the vaginal microbiomes of mono- and dizygotic twin pairs selected from the over 170,000 twin pairs in the Mid-Atlantic Twin Registry (MATR). Subsequent studies, beyond the scope of the current project, may investigate which host genes impact the microbial flora and how they do so.
*2.	What changes in the microbiome are associated with common non-infectious pathological states of the host?* We hypothesize that altered physiological (e.g., pregnancy) and pathologic (e.g., immune suppression) conditions, or environmental exposures (e.g., antibiotics) predictably alter the vaginal microbiome. Conversely, certain vaginal microbiome characteristics are thought to contribute to a woman’s risk for outcomes such as preterm delivery. We are addressing this question by recruiting study participants from the ~40,000 annual clinical visits to women’s clinics of the VCU Health System.
*3.	What changes in the vaginal microbiome are associated with relevant infectious diseases and conditions?* We hypothesize that susceptibility to infectious disease (e.g. HPV, _Chlamydia_ infection, vaginitis, vaginosis, etc.) is impacted by the vaginal microbiome. In turn, these infectious conditions clearly can affect the ability of other bacteria to colonize and cause pathology. Again, we are exploring these issues by recruiting participants from visitors to women’s clinics in the VCU Health System.

Three kinds of sequence data are generated in this project: i) rDNA sequences from vaginal microbes; ii) whole metagenome shotgun sequences from vaginal samples; and iii) whole genome shotgun sequences of bacterial clones selected from vaginal samples. The study includes samples from three vaginal sites: mid-vaginal, cervical, and introital. The data sets also include buccal and perianal samples from all twin participants. Samples from these additional sites are used to test the hypothesis of a per continuum spread of bacteria in relation to vaginal health. An extended set of clinical metadata associated with these sequences are deposited with dbGAP. We have currently collected over 4,400 samples from ~100 twins and over 450 clinical participants. We have analyzed and deposited data for 480 rDNA samples, eight whole metagenome shotgun samples, and over 50 complete bacterial genomes. These data are available to accredited investigators according to NIH and Human Microbiome Project (HMP) guidelines. The bacterial clones are deposited in the Biodefense and Emerging Infections Research Resources Repository ("http://www.beiresources.org/":http://www.beiresources.org/). 

In addition to the extensive sequence data obtained in this study, we are collecting metadata associated with each of the study participants. Thus, participants are asked to complete an extensive health history questionnaire at the time samples are collected. Selected clinical data associated with the visit are also obtained, and relevant information is collected from the medical records when available. This data is maintained securely in a HIPAA-compliant data system as required by VCU’s Institutional Review Board (IRB). The preponderance of these data (i.e., that judged appropriate by NIH staff and VCU’s IRB are deposited at dbGAP ("http://www.ncbi.nlm.nih.gov/gap":http://www.ncbi.nlm.nih.gov/gap). Selected fields of this data have been identified by NIH staff as ‘too sensitive’ and are not available in dbGAP. Individuals requiring access to these data fields are asked to contact the PI of this project or NIH Program Staff. 
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    Absence of influence of gender and BMPR2 mutation type on clinical phenotypes of pulmonary arterial hypertension

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    <p>Abstract</p> <p>Background</p> <p>Previous studies indicate that patients with pulmonary arterial hypertension (PAH) carrying a mutation in the bone morphogenetic protein receptor type 2 (<it>BMPR2</it>) gene, develop the disease 10 years earlier than non-carriers, and have a more severe hemodynamic compromise at diagnosis. A recent report has suggested that this may only be the case for females and that patients with missense mutations in <it>BMPR2 </it>gene have more severe disease than patients with truncating mutations.</p> <p>Methods</p> <p>We reviewed data from all patients with PAH considered as idiopathic and patients with a family history of PAH, who underwent genetic counselling in the French PAH network between January, 1<sup>st </sup>2004 and April, 1<sup>st </sup>2010. We compared clinical, functional, and hemodynamic characteristics between carriers and non-carriers of a <it>BMPR2 </it>mutation, according to gender or <it>BMPR2 </it>mutation type.</p> <p>Results</p> <p>PAH patients carrying a <it>BMPR2 </it>mutation (n = 115) were significantly younger at diagnosis than non-carriers (n = 267) (35.8 ± 15.4 and 47.5 ± 16.2 respectively, p < 0.0001). The presence of a <it>BMPR2 </it>mutation was associated with a younger age at diagnosis in females (36.4 ± 14.9 in <it>BMPR2 </it>mutation carriers and 47.4 ± 15.8 in non-carriers, p < 0.0001), and males (34.6 ± 16.8 in <it>BMPR2 </it>mutation carriers and 47.8 ± 17.1 in non-carriers, p < 0.0001). <it>BMPR2 </it>mutation carriers had a more severe hemodynamic compromise at diagnosis, but this was not influenced by gender. No differences in survival and time to death or lung transplantation were found in male and female PAH patients carrying a <it>BMPR2 </it>mutation. No differences were observed in clinical outcomes according to the type of <it>BMPR2 </it>mutations (missense, truncating, large rearrangement or splice defect).</p> <p>Conclusion</p> <p>When compared to non-carriers, <it>BMPR2 </it>mutation carriers from the French PAH network are younger at diagnosis and present with a more severe hemodynamic compromise, irrespective of gender. Moreover, <it>BMPR2 </it>mutation type had no influence on clinical phenotypes in our patient population.</p

    Advancing Tests of Relativistic Gravity via Laser Ranging to Phobos

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    Phobos Laser Ranging (PLR) is a concept for a space mission designed to advance tests of relativistic gravity in the solar system. PLR's primary objective is to measure the curvature of space around the Sun, represented by the Eddington parameter γ\gamma, with an accuracy of two parts in 10710^7, thereby improving today's best result by two orders of magnitude. Other mission goals include measurements of the time-rate-of-change of the gravitational constant, GG and of the gravitational inverse square law at 1.5 AU distances--with up to two orders-of-magnitude improvement for each. The science parameters will be estimated using laser ranging measurements of the distance between an Earth station and an active laser transponder on Phobos capable of reaching mm-level range resolution. A transponder on Phobos sending 0.25 mJ, 10 ps pulses at 1 kHz, and receiving asynchronous 1 kHz pulses from earth via a 12 cm aperture will permit links that even at maximum range will exceed a photon per second. A total measurement precision of 50 ps demands a few hundred photons to average to 1 mm (3.3 ps) range precision. Existing satellite laser ranging (SLR) facilities--with appropriate augmentation--may be able to participate in PLR. Since Phobos' orbital period is about 8 hours, each observatory is guaranteed visibility of the Phobos instrument every Earth day. Given the current technology readiness level, PLR could be started in 2011 for launch in 2016 for 3 years of science operations. We discuss the PLR's science objectives, instrument, and mission design. We also present the details of science simulations performed to support the mission's primary objectives.Comment: 25 pages, 10 figures, 9 table

    A detector to monitor the neutrino beam asymmetry at the T2K 280m hall

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    We propose to build and operate a new detector for the T2K 280m hall with the purpose of measuring and monitoring the possible neutrino beam left-right asymmetry with respect to the beam axis. The measurement will be performed by means of two identical detectors (modules) made of a sandwich of iron plates and planes of scintillator bars read out by WLS fibers and multianode PMTs. The two modules could be swapped in their positions in order to minimize systematic errors. We show that an overall uncertainty of less than 5% in the measurement of the beam asymmetry could be reached within one year of running

    First events from the CNGS neutrino beam detected in the OPERA experiment

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    The OPERA neutrino detector at the underground Gran Sasso Laboratory (LNGS) was designed to perform the first detection of neutrino oscillations in appearance mode, through the study of nu_mu to nu_tau oscillations. The apparatus consists of a lead/emulsion-film target complemented by electronic detectors. It is placed in the high-energy, long-baseline CERN to LNGS beam (CNGS) 730 km away from the neutrino source. In August 2006 a first run with CNGS neutrinos was successfully conducted. A first sample of neutrino events was collected, statistically consistent with the integrated beam intensity. After a brief description of the beam and of the various sub-detectors, we report on the achievement of this milestone, presenting the first data and some analysis results.Comment: Submitted to the New Journal of Physic

    Hemorrhage-Adjusted Iron Requirements, Hematinics and Hepcidin Define Hereditary Hemorrhagic Telangiectasia as a Model of Hemorrhagic Iron Deficiency

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    BACKGROUND: Iron deficiency anemia remains a major global health problem. Higher iron demands provide the potential for a targeted preventative approach before anemia develops. The primary study objective was to develop and validate a metric that stratifies recommended dietary iron intake to compensate for patient-specific non-menstrual hemorrhagic losses. The secondary objective was to examine whether iron deficiency can be attributed to under-replacement of epistaxis (nosebleed) hemorrhagic iron losses in hereditary hemorrhagic telangiectasia (HHT). METHODOLOGY/PRINCIPAL FINDINGS: The hemorrhage adjusted iron requirement (HAIR) sums the recommended dietary allowance, and iron required to replace additional quantified hemorrhagic losses, based on the pre-menopausal increment to compensate for menstrual losses (formula provided). In a study population of 50 HHT patients completing concurrent dietary and nosebleed questionnaires, 43/50 (86%) met their recommended dietary allowance, but only 10/50 (20%) met their HAIR. Higher HAIR was a powerful predictor of lower hemoglobin (p = 0.009), lower mean corpuscular hemoglobin content (p<0.001), lower log-transformed serum iron (p = 0.009), and higher log-transformed red cell distribution width (p<0.001). There was no evidence of generalised abnormalities in iron handling Ferritin and ferritin(2) explained 60% of the hepcidin variance (p<0.001), and the mean hepcidinferritin ratio was similar to reported controls. Iron supplement use increased the proportion of individuals meeting their HAIR, and blunted associations between HAIR and hematinic indices. Once adjusted for supplement use however, reciprocal relationships between HAIR and hemoglobin/serum iron persisted. Of 568 individuals using iron tablets, most reported problems completing the course. For patients with hereditary hemorrhagic telangiectasia, persistent anemia was reported three-times more frequently if iron tablets caused diarrhea or needed to be stopped. CONCLUSIONS/SIGNIFICANCE: HAIR values, providing an indication of individuals' iron requirements, may be a useful tool in prevention, assessment and management of iron deficiency. Iron deficiency in HHT can be explained by under-replacement of nosebleed hemorrhagic iron losses
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