Recombinant gas vesicles from Halobacterium sp. displaying SIV peptides demonstrate biotechnology potential as a pathogen peptide delivery vehicle

<p>Abstract</p> <p>Background</p> <p>Previous studies indicated that recombinant gas vesicles (r-GV) from a mutant strain of <it>Halobacterium sp</it>. NRC-1 could express a cassette containing test sequences of SIVmac <it>gag </it>derived DNA, and function as an antigen display/delivery system. Tests using mice indicated that the humoral immune response to the <it>gag </it>encoded sequences evoked immunologic memory in the absence of an exogenous adjuvant.</p> <p>Results</p> <p>The goal of this research was to extend this demonstration to diverse gene sequences by testing recombinant gas vesicles displaying peptides encoded by different SIV genes (SIV^{<it>tat</it>, <it>rev </it>or <it>nef</it>}). Verification that different peptides can be successfully incorporated into the GvpC surface protein of gas vesicle would support a more general biotechnology application of this potential display/delivery system. Selected SIVsm-GvpC fusion peptides were generated by creating and expressing fusion genes, then assessing the resulting recombinant gas vesicles for SIV peptide specific antigenic and immunogenic capabilities. Results from these analyses support three conclusions: (i) Different recombinant <it>gvpC</it>-SIV genes will support the biosynthesis of chimeric, GvpC fusion proteins which are incorporated into the gas vesicles and generate functional organelles. (ii) Monkey antibody elicited by <it>in vivo </it>infection with SHIV recognizes these expressed SIV sequences in the fusion proteins encoded by the <it>gvpC</it>-SIV fusion genes as SIV peptides. (iii) Test of antiserum elicited by immunizing mice with recombinant gas vesicles demonstrated notable and long term antibody titers. The observed level of humoral responses, and the maintenance of elevated responses to, Tat, Rev and Nef1 encoded peptides carried by the respective r-GV, are consistent with the suggestion that <it>in vivo </it>there may be a natural and slow release of epitope over time.</p> <p>Conclusion</p> <p>The findings therefore suggest that in addition to providing information about these specific inserts, r-GV displaying peptide inserts from other relevant pathogens could have significant biotechnological potential for display and delivery, or serve as a cost effective initial screen of pathogen derived peptides naturally expressed during infections <it>in vivo</it>.</p

JOINTLY MODELING CONTINUOUS AND BINARY OUTCOMES FOR BOOLEAN OUTCOMES: AN APPLICATION TO MODELING HYPERTENSION

Binary outcomes defined by logical (Boolean) and or or operations on original continuous and discrete outcomes arise commonly in medical diagnoses and epidemiological research. In this manuscript,we consider applying the “or” operator to two continuous variables above a threshold and a binary variable, a setting that occurs frequently in the modeling of hypertension. Rather than modeling the resulting composite outcome defined by the logical operator, we present a method that models the original outcomes thus utilizing all information in the data, yet continues to yield conclusions on the composite scale. A stratified propensity score adjustment is proposed to account for confounding variables. A Mantel-Haenszel style combination of strata-specific odds ratios is proposed to evaluate a risk factor. The benefits of the proposed approach include easy handling of missing data and the ability to estimate the correlations between the original outcomes. We emphasize that the model retains the ability to evaluate odds ratios on the simpler and more easily interpreted composite scale. The approach is evaluated by Monte Carlo simulations. An example of the analysis of the impact of sleep disordered breathing on a standard composite hypertension measure, based on blood pressure measurements and medication usage,is included

Uptake and intra-inclusion accumulation of exogenous immunoglobulin by Chlamydia-infected cells

<p>Abstract</p> <p>Background</p> <p>Obligate intracellular pathogens belonging to the <it>Chlamydiaceae </it>family possess a number of mechanisms by which to manipulate the host cell and surrounding environment. Such capabilities include the inhibition of apoptosis, down-regulation of major histocompatability complex (MHC) and CD1/d gene expression, and the acquisition of host-synthesized nutrients. It is also documented that a limited number of host-derived macromolecules such as β-catenin and sphingomyelin accumulate within the inclusion.</p> <p>Results</p> <p>This report provides evidence that immunoglobulin, inherently present in the extracellular environment <it>in vivo </it>and <it>in vitro</it>, enters infected cells and accumulates within the chlamydial inclusion. Using epi-fluorescent and confocal microscopy, this selective uptake of Ig is shown to occur among human leukocytes <it>in vivo </it>as well as cells cultured <it>in vitro</it>. These findings were confirmed by detection of IgG in the lysate of infected cells by western blot hybridization. Sequestered antibodies appear to be present during the entire course of the chlamydial developmental cycle and are distributed throughout this compartment. IgG pre-labeled with fluorescein, when added to the supernatant of infected cell cultures, was also imported and readily visualized. Accumulation of these molecules within the inclusion and the failure of bovine serum albumin or F(ab')₂fragments to accumulate in a similar manner suggests the process of entry is specific for intact IgG molecules and not a result of pinocytosis, diffusion, or any other mass endocytic event.</p> <p>Conclusion</p> <p>Sequestration of a host cell-derived protein within the chlamydial inclusion, although unexpected, is not an unprecedented occurrence. However, selective accumulation of an exogenous host protein, such as extracellular IgG, has not been previously reported in connection with chlamydial infections. The selectivity of this process may indicate that this uptake plays an important role in pathogen physiology or virulence during infection and the phenomenon itself may give rise to novel diagnostic and therapeutic approaches.</p

Parental monitoring trajectories and gambling among a longitudinal cohort of urban youth

Aim: To test the strength of the association between parental monitoring trajectories throughout early adolescence (ages 11–14) and gambling behaviours by young adulthood (age 22). Design: Longitudinal cohort design. Setting: Baltimore, Maryland. Participants: The sample of 514 participants with gambling data between ages 16–22 and parental monitoring data between ages 11–14 were predominantly African American and received subsidized lunches at age 6. Measurements: The South Oaks Gambling Screen and South Oaks Gambling Screen–Revised for Adolescents collected self-reports on annual gambling and gambling problems between ages 16–22. The Parental Monitoring Subscale of the Structured Interview of Parent Management Skills and Practices–Youth Version collected self-reports on annual parental monitoring between ages 11–14. Findings: General growth mixture modelling identified two parental monitoring trajectories: (i) ‘stable’ class (84.9%) began with a high level of parental monitoring at age 11 that remained steady to age 14; (ii) ‘declining’ class (15.1%) began with a significantly lower level of parental monitoring at age 11 and experienced a significant to through age 14. The declining class had increased significantly unadjusted (OR = 1.91; 95% CI = 1.59, 2.23; P ≤ 0.001) and adjusted (aOR = 1.57; 95% CI = 1.24, 1.99; P = 0.01) odds of problem gambling compared with non-gambling. Conclusion: Low and/or declining parental monitoring of children between the ages of 11 and 14 is associated significantly with problem gambling when those children reach young adulthood

Neurohormonal activation in patients with right ventricular failure from pulmonary hypertension: Relation to hemodynamic variables and endothelin levels

Objectives.This study sought to determine whether neurohormonal activation occurs in isolated right heart failure.Background.Neurohormonal activation appears to parallel the severity of left heart failure, but little is known about its role in right heart failure.Methods.We evaluated neurohormonal activation and endothelin levels in 21 patients with primary pulmonary hypertension at the time of right heart catheterization.Results.Plasma norepinephrine levels correlated significantly with pulmonary artery pressure (r = 0.66, p < 0.01), cardiac index (r = −0.56, p < 0.01) and pulmonary vascular resistance (r = 0.69, p < 0.001). Atrial natriuretic peptide levels were higher in the pulmonary artery than the right atrium and femoral artery and correlated closely with pulmonary artery oxygen saturation (r = −0. 73, p < 0.0001). Plasma renin levels were not elevated. Endothelin levels were increased and correlated with right atrial pressure (r = 0.74, p < 0.0001) and pulmonary artery oxygen saturation (r = −0.070, p < 0.0004).Conclusions.Neurohormonal activation occurs in patients with isolated right ventricular failure and inherently normal left ventricles and appears to be related to the overall severity of cardiopulmonary derangements. The elevation in endothelin levels is consistent with its release in response to pulmonary hypertension

Implications of Middle School Behavior Problems for High School Graduation and Employment Outcomes of Young Adults: Estimation of a Recursive Model

The potentially serious adverse impacts of behavior problems during adolescence on employment outcomes in adulthood provide a key economic rationale for early intervention programs. However, the extent to which lower educational attainment accounts for the total impact of adolescent behavior problems on later employment remains unclear As an initial step in exploring this issue, we specify and estimate a recursive bivariate probit model that 1) relates middle school behavior problems to high school graduation and 2) models later employment in young adulthood as a function of these behavior problems and of high school graduation. Our model thus allows for both a direct effect of behavior problems on later employment as well as an indirect effect that operates via graduation from high school. Our empirical results, based on analysis of data from the NELS, suggest that the direct effects of externalizing behavior problems on later employment are not significant but that these problems have important indirect effects operating through high school graduation.

High-throughput screening in larval zebrafish identifies novel potent sedative-hypnotics

BACKGROUND: Many general anesthetics were discovered empirically, but primary screens to find new sedative-hypnotics in drug libraries have not used animals, limiting the types of drugs discovered. The authors hypothesized that a sedative-hypnotic screening approach using zebrafish larvae responses to sensory stimuli would perform comparably to standard assays, and efficiently identify new active compounds. METHODS: The authors developed a binary outcome photomotor response assay for zebrafish larvae using a computerized system that tracked individual motions of up to 96 animals simultaneously. The assay was validated against tadpole loss of righting reflexes, using sedative-hypnotics of widely varying potencies that affect various molecular targets. A total of 374 representative compounds from a larger library were screened in zebrafish larvae for hypnotic activity at 10 µM. Molecular mechanisms of hits were explored in anesthetic-sensitive ion channels using electrophysiology, or in zebrafish using a specific reversal agent. RESULTS: Zebrafish larvae assays required far less drug, time, and effort than tadpoles. In validation experiments, zebrafish and tadpole screening for hypnotic activity agreed 100% (n = 11; P = 0.002), and potencies were very similar (Pearson correlation, r > 0.999). Two reversible and potent sedative-hypnotics were discovered in the library subset. CMLD003237 (EC50, ~11 µM) weakly modulated γ-aminobutyric acid type A receptors and inhibited neuronal nicotinic receptors. CMLD006025 (EC50, ~13 µM) inhibited both N-methyl-D-aspartate and neuronal nicotinic receptors. CONCLUSIONS: Photomotor response assays in zebrafish larvae are a mechanism-independent platform for high-throughput screening to identify novel sedative-hypnotics. The variety of chemotypes producing hypnosis is likely much larger than currently known.This work was supported by grants from Shanghai Jiaotong University School of Medicine, Shanghai, China, and the Chinese Medical Association, Beijing, China (both to Dr. Yang). The Department of Anesthesia, Critical Care and Pain Medicine of Massachusetts General Hospital, Boston, Massachusetts, supported this work through a Research Scholars Award and an Innovation Grant (both to Dr. Forman). Contributions to this research from the Boston University Center for Molecular Discovery, Boston, Massachusetts (to Drs. Porco, Brown, Schaus, and Xu, and to Mr. Trilles), were supported by a grant from the National Institutes of Health, Bethesda, Maryland (grant No. R24 GM111625). (Shanghai Jiaotong University School of Medicine, Shanghai, China; Chinese Medical Association, Beijing, China; Department of Anesthesia, Critical Care and Pain Medicine of Massachusetts General Hospital, Boston, Massachusetts; R24 GM111625 - National Institutes of Health, Bethesda, Maryland)Accepted manuscript2019-09-0

H-ATLAS/GAMA and HeViCS - dusty early-type galaxies in different environments

NKA acknowledges the support of the Science and Technology Facilities Council. LD, RJI and SJM acknowledge support from the European Research Council Advanced Grant COSMICISM. IDL gratefully acknowledges the support of the Flemish Fund for Scientific Research (FWO-Vlaanderen). KR acknowledges support from the European Research Council Starting Grant SEDmorph (P.I. V. Wild). Date of acceptance: 22/05/2015The Herschel Space Observatory has had a tremendous impact on the study of extragalactic dust. Specifically, early-type galaxies (ETG) have been the focus of several studies. In this paper, we combine results from two Herschel studies -a Virgo cluster study Herschel Virgo Cluster Survey (HeViCS) and a broader, low-redshift Herschel-Astrophysical Terahertz Large Area Survey (H-ATLAS)/Galaxy and Mass Assembly (GAMA) study -and contrast the dust and associated properties for similar mass galaxies. This comparison is motivated by differences in results exhibited between multiple Herschel studies of ETG. A comparison between consistent modified blackbody derived dust mass is carried out, revealing strong differences between the two samples in both dust mass and dust-to-stellar mass ratio. In particular, the HeViCS sample lacks massive ETG with as high a specific dust content as found in H-ATLAS. This is most likely connected with the difference in environment for the two samples. We calculate nearest neighbour environment densities in a consistent way, showing that H-ATLAS ETG occupy sparser regions of the local Universe, whereas HeViCS ETG occupy dense regions. This is also true for ETG that are not Herschel-detected but are in the Virgo and GAMA parent samples. Spectral energy distributions are fit to the panchromatic data. From these, we find that in H-ATLAS the specific star formation rate anticorrelates with stellar mass and reaches values as high as in our Galaxy. On the other hand HeViCS ETG appear to have little star formation. Based on the trends found here, H-ATLAS ETG are thought to have more extended star formation histories and a younger stellar population than HeViCS ETG.Publisher PDFPeer reviewe