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Search Results: 1 - 10 of 407106 matches for " Lisette M. Johnson-Hill "
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Smoking Enhances Risk for New External Genital Warts in Men
Dorothy J. Wiley,David Elashoff,Emmanuel V. Masongsong,Diane M. Harper,Karen H. Gylys,Michael J. Silverberg,Robert L. Cook,Lisette M. Johnson-Hill
International Journal of Environmental Research and Public Health , 2009, DOI: 10.3390/ijerph6031215
Abstract: Repeat episodes of HPV-related external genital warts reflect recurring or new infections. No study before has been sufficiently powered to delineate how tobacco use, prior history of EGWs and HIV infection affect the risk for new EGWs. Behavioral, laboratory and examination data for 2,835 Multicenter AIDS Cohort Study participants examined at 21,519 semi-annual visits were evaluated. Fourteen percent (391/2835) of men reported or were diagnosed with EGWs at 3% (675/21,519) of study visits. Multivariate analyses showed smoking, prior episodes of EGWs, HIV infection and CD4+ T-lymphocyte count among the infected, each differentially influenced the risk for new EGWs.
Sleep Disordered Breathing, Fatigue, and Sleepiness in HIV-Infected and -Uninfected Men
Susheel P. Patil, Todd T. Brown, Lisa P. Jacobson, Joseph B. Margolick, Alison Laffan, Lisette Johnson-Hill, Rebecca Godfrey, Jacquett Johnson, Sandra Reynolds, Alan R. Schwartz, Philip L. Smith
PLOS ONE , 2014, DOI: 10.1371/journal.pone.0099258
Abstract: Study Objectives We investigated the association of HIV infection and highly active antiretroviral therapy (HAART) with sleep disordered breathing (SDB), fatigue, and sleepiness. Methods HIV-uninfected men (HIV?; n = 60), HIV-infected men using HAART (HIV+/HAART+; n = 58), and HIV-infected men not using HAART (HIV+/HAART?; n = 41) recruited from two sites of the Multicenter AIDS cohort study (MACS) underwent a nocturnal sleep study, anthropometric assessment, and questionnaires for fatigue and the Epworth Sleepiness Scale. The prevalence of SDB in HIV- men was compared to that in men matched from the Sleep Heart Health Study (SHHS). Results The prevalence of SDB was unexpectedly high in all groups: 86.7% for HIV?, 70.7% for HIV+/HAART+, and 73.2% for HIV+/HAART?, despite lower body-mass indices (BMI) in HIV+ groups. The higher prevalence in the HIV? men was significant in univariate analyses but not after adjustment for BMI and other variables. SDB was significantly more common in HIV? men in this study than those in SHHS, and was common in participants with BMIs <25 kg/m2. HIV+ men reported fatigue more frequently than HIV? men (25.5% vs. 6.7%; p = 0.003), but self-reported sleepiness did not differ among the three groups. Sleepiness, but not fatigue, was significantly associated with SDB. Conclusions SDB was highly prevalent in HIV? and HIV+ men, despite a normal or slightly elevated BMI. The high rate of SDB in men who have sex with men deserves further investigation. Sleepiness, but not fatigue, was related to the presence of SDB. Clinicians caring for HIV-infected patients should distinguish between fatigue and sleepiness when considering those at risk for SDB, especially in non-obese men.
Foreground-Induced Biases in CMB Polarimeter Self-Calibration
M. H. Abitbol,J. C. Hill,B. R. Johnson
Physics , 2015,
Abstract: Precise polarisation measurements of the cosmic microwave background (CMB) require accurate knowledge of the instrument orientation relative to the sky frame used to define the cosmological Stokes parameters. Suitable celestial calibration sources that could be used to measure the polarimeter orientation angle are limited, so current experiments commonly `self-calibrate.' The self-calibration method exploits the theoretical fact that the $EB$ and $TB$ cross-spectra of the CMB vanish in the standard cosmological model, so any detected $EB$ and $TB$ signals must be due to systematic errors. However, this assumption neglects the fact that polarized Galactic foregrounds in a given portion of the sky may have non-zero $EB$ and $TB$ cross-spectra. If these foreground signals remain in the observations, then they will bias the self-calibrated telescope polarisation angle and produce a spurious $B$-mode signal. In this paper we estimate the foreground-induced bias for various instrument configurations and then expand the self-calibration formalism to account for polarized foreground signals. Assuming the $EB$ correlation signal for dust is in the range constrained by angular power spectrum measurements from Planck at 353 GHz (scaled down to 150 GHz), then the bias is negligible for high angular resolution experiments, which have access to CMB-dominated high $\ell$ modes with which to self-calibrate. Low-resolution experiments observing particularly dusty sky patches can have a bias as large as $0.5^\circ$. A miscalibration of this magnitude generates a spurious $BB$ signal corresponding to a tensor-to-scalar ratio of approximately $r\sim2\times10^{-3}$, within the targeted range of planned experiments.
Clinical Evaluation of Fluido Compact: A New Intravenous Fluid Warmer  [PDF]
Juan M. Zaballos, Lisette De la Cruz
Open Journal of Anesthesiology (OJAnes) , 2017, DOI: 10.4236/ojanes.2017.74010
Abstract: Unintended peri-operative hypothermia is very common in surgical patients and is associated with adverse outcomes. Perioperative use of forced-air and intravenous fluid warmers is recommended for hypothermia prevention. This study evaluated the ease of use of Fluido Compact, a new fluid warming device, and its ability to help as part of the intraoperative patient temperature management. It was used in 36 patients undergoing scheduled surgery at risk of hypothermia under regional, general or combined anesthesia, of more than one hour duration and with a predicted intravenous fluid administration of at least 1000 ml. The fluid warmer is very easy to set up. The disposable cassette has a very low (3 ml) priming volume and it is easy to handle and to place inside the warming module. Once connected to the main power outlet, it is ready to deliver fluid at target temperature in just a few seconds. Control panel is intuitive, and the one button operation system makes it safe and convenient. The combination of peri-operative patient surface warming with Mistral-Air forced-air warming system and intravenous fluid warming with Fluido Compact, that allowed the administration of IV perfusions at body temperature at the rate needed thus avoiding heat loss, helps to maintain intraoperative core temperature between 36.4°C and 36.8°C. A group of patients undergo a variety of surgical procedures with neuraxial, general or combined epidural-general anesthesia.
Stromal Cell-Derived Factor-1β Mediates Cell Survival through Enhancing Autophagy in Bone Marrow-Derived Mesenchymal Stem Cells
Samuel Herberg, Xingming Shi, Maribeth H. Johnson, Mark W. Hamrick, Carlos M. Isales, William D. Hill
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0058207
Abstract: Bone marrow-derived mesenchymal stem/stromal cells (BMSCs) hold great potential for cell-based therapy, yet the therapeutic efficacy remains uncertain. Transplanted BMSCs often fail to engraft within the bone marrow (BM), in part due to the poor survival of donor cells in response to inflammatory reactions, hypoxia, oxidative stress, or nutrient starvation. Two basic cell processes, apoptosis and autophagy, could potentially be responsible for the impaired survival of transplanted BMSCs. However, the functional relationship between apoptosis and autophagy in BMSC homeostasis is complex and not well understood. The stromal cell-derived factor-1 (SDF-1)/CXC chemokine receptor 4 (CXCR4) signaling axis appears to be critical in maintaining proliferation and survival of BM stem cell populations through improving cell proliferation and survival in response to stress; however, the exact mechanisms remain unclear. We recently described novel genetically engineered Tet-Off-SDF-1β BMSCs, which over-express SDF-1β under tight doxycycline-control, thus providing an ideal model system to investigate the isolated effects of SDF-1β. In this study we tested the hypothesis that SDF-1β can mediate cell survival of BMSCs in vitro through increasing autophagy. We found that SDF-1β had no effect on BMSC proliferation; however, SDF-1β significantly protected genetically engineered BMSCs from H2O2-induced cell death through increasing autophagy and decreasing caspase-3-dependent apoptosis. Taken together, we provide novel evidence that the SDF-1/CXCR4 axis, specifically activated by the SDF-1β isoform, plays a critical role in regulating BMSC survival under oxidative stress through increasing autophagy.
Renal effects of uroguanylin and guanylin in vivo
Carrithers S.L.,Hill M.J.,Johnson B.R.,O'Hara S.M.
Brazilian Journal of Medical and Biological Research , 1999,
Abstract: Uroguanylin and guanylin are newly discovered endogenous heat-stable peptides that bind to and activate a membrane bound guanylyl cyclase signaling receptor (termed guanylyl cyclase C; GC-C). These peptides are not only found in blood but are secreted into the lumen of the intestine and effect a net secretion of electrolytes (Na+, K+, Cl-, HCO3-) and fluid into the intestine via a cyclic guanosine-3',5'-monophosphate (cGMP) mechanism. GC-C is also the receptor for Escherichia coli heat-stable enterotoxin (STa) and activation by STa results in a diarrheal illness. Employing mouse renal in vivo models, we have demonstrated that uroguanylin, guanylin, and STa elicit natriuretic, kaliuretic, and diuretic effects. These biological responses are time- and dose-dependent. Maximum natriuretic and kaliuretic effects are observed within 30-40 min following infusion with pharmacological doses of the peptides in a sealed-urethra mouse model. Our mouse renal clearance model confirms these results and shows significant natriuresis following a constant infusion of uroguanylin for 30 min, while the glomerular filtration rate, plasma creatinine, urine osmolality, heart rate, and blood pressure remain constant. These data suggest the peptides act through tubular transport mechanisms. Consistent with a tubular mechanism, messenger RNA-differential display PCR of kidney RNA extracted from vehicle- and uroguanylin-treated mice show the message for the Na+/K+ ATPase g-subunit is down-regulated. Interestingly, GC-C knockout mice (Gucy2c -/-) also exhibit significant uroguanylin-induced natriuresis and kaliuresis in vivo, suggesting the presence of an alternate receptor signaling mechanism in the kidney. Thus, uroguanylin and guanylin seem to serve as intestinal and renal natriuretic peptide-hormones influencing salt and water transport in the kidney through GC-C dependent and independent pathways. Furthermore, our recent clinical probe study has revealed a 70-fold increase in levels of urinary uroguanylin in patients with congestive heart failure. In conclusion, our studies support the concept that uroguanylin and guanylin are endogenous effector peptides involved in regulating body salt and water homeostasis.
Absence of Functional Leptin Receptor Isoforms in the POUND (Leprdb/lb) Mouse Is Associated with Muscle Atrophy and Altered Myoblast Proliferation and Differentiation
Phonepasong Arounleut, Matthew Bowser, Sunil Upadhyay, Xing-Ming Shi, Sadanand Fulzele, Maribeth H. Johnson, Alexis M. Stranahan, William D. Hill, Carlos M. Isales, Mark W. Hamrick
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0072330
Abstract: Objective Leptin receptors are abundant in human skeletal muscle, but the role of leptin in muscle growth, development and aging is not well understood. Here we utilized a novel mouse model lacking all functional leptin receptor isoforms (POUND mouse, Leprdb/lb) to determine the role of leptin in skeletal muscle. Methods and Findings Skeletal muscle mass and fiber diameters were examined in POUND mice, and primary myoblast cultures were used to determine the effects of altered leptin signaling on myoblast proliferation and differentiation. ELISA assays, integrated pathway analysis of mRNA microarrays, and reverse phase protein analysis were performed to identify signaling pathways impacted by leptin receptor deficiency. Results show that skeletal muscle mass and fiber diameter are reduced 30–40% in POUND mice relative to wild-type controls. Primary myoblast cultures demonstrate decreased proliferation and decreased expression of both MyoD and myogenin in POUND mice compared to normal mice. Leptin treatment increased proliferation in primary myoblasts from muscles of both adult (12 months) and aged (24 months) wild-type mice, and leptin increased expression of MyoD and myogenin in aged primary myoblasts. ELISA assays and protein arrays revealed altered expression of molecules associated with the IGF-1/Akt and MAPK/MEK signaling pathways in muscle from the hindlimbs of mice lacking functional leptin receptors. Conclusion These data support the hypothesis that the adipokine leptin is a key factor important for the regulation of skeletal muscle mass, and that leptin can act directly on its receptors in peripheral tissues to regulate cell proliferation and differentiation.
Helicobacter pylori Exploits a Unique Repertoire of Type IV Secretion System Components for Pilus Assembly at the Bacteria-Host Cell Interface
Carrie L. Shaffer,Jennifer A. Gaddy,John T. Loh,Elizabeth M. Johnson,Salisha Hill,Ewa E. Hennig,Mark S. McClain,W. Hayes McDonald,Timothy L. Cover
PLOS Pathogens , 2011, DOI: 10.1371/journal.ppat.1002237
Abstract: Colonization of the human stomach by Helicobacter pylori is an important risk factor for development of gastric cancer. The H. pylori cag pathogenicity island (cag PAI) encodes components of a type IV secretion system (T4SS) that translocates the bacterial oncoprotein CagA into gastric epithelial cells, and CagL is a specialized component of the cag T4SS that binds the host receptor α5β1 integrin. Here, we utilized a mass spectrometry-based approach to reveal co-purification of CagL, CagI (another integrin-binding protein), and CagH (a protein with weak sequence similarity to CagL). These three proteins are encoded by contiguous genes in the cag PAI, and are detectable on the bacterial surface. All three proteins are required for CagA translocation into host cells and H. pylori-induced IL-8 secretion by gastric epithelial cells; however, these proteins are not homologous to components of T4SSs in other bacterial species. Scanning electron microscopy analysis reveals that these proteins are involved in the formation of pili at the interface between H. pylori and gastric epithelial cells. ΔcagI and ΔcagL mutant strains fail to form pili, whereas a ΔcagH mutant strain exhibits a hyperpiliated phenotype and produces pili that are elongated and thickened compared to those of the wild-type strain. This suggests that pilus dimensions are regulated by CagH. A conserved C-terminal hexapeptide motif is present in CagH, CagI, and CagL. Deletion of these motifs results in abrogation of CagA translocation and IL-8 induction, and the C-terminal motifs of CagI and CagL are required for formation of pili. In summary, these results indicate that CagH, CagI, and CagL are components of a T4SS subassembly involved in pilus biogenesis, and highlight the important role played by unique constituents of the H. pylori cag T4SS.
Recreational Exposure to Low Concentrations of Microcystins During an Algal Bloom in a Small Lake
Lorraine C. Backer,Wayne Carmichael,Barbara Kirkpatrick,Christopher Williams,Mitch Irvin,Yue Zhou,Trisha B. Johnson,Kate Nierenberg,Vincent R. Hill,Stephanie M. Kieszak,Yung-Sung Cheng
Marine Drugs , 2008, DOI: 10.3390/md6020389
Abstract: We measured microcystins in blood from people at risk for swallowing water or inhaling spray while swimming, water skiing, jet skiing, or boating during an algal bloom. We monitored water samples from a small lake as a Microcystis aeruginosa bloom developed. We recruited 97 people planning recreational activities in that lake and seven others who volunteered to recreate in a nearby bloom-free lake. We conducted our field study within a week of finding a 10-μg/L microcystin concentration. We analyzed water, air, and human blood samples for water quality, potential human pathogens, algal taxonomy, and microcystin concentrations. We interviewed study participants for demographic and current health symptom information. Water samples were assayed for potential respiratory viruses (adenoviruses and enteroviruses), but none were detected. We did find low concentrations of Escherichia coli, indicating fecal contamination. We found low levels of microcystins (2 μg/L to 5 μg/L) in the water and (<0.1 ng/m3) in the aerosol samples. Blood levels of microcystins for all participants were below the limit of detection (0.147μg/L). Given this low exposure level, study participants reported no symptom increases following recreational exposure to microcystins. This is the first study to report that water-based recreational activities can expose people to very low concentrations of aerosol-borne microcystins; we recently conducted another field study to assess exposures to higher concentrations of these algal toxins.
A study evaluating the effect of Educational Needs Assessment Tool (ENAT) focused patient education, on health outcomes in patients with Rheumatoid Arthritis: Protocol of an ongoing study  [PDF]
Bernadette Hardware, Claire Hale, Dawn Johnson, Jackie Hill, Tracey Young, Adewale Adebajo
Open Journal of Nursing (OJN) , 2013, DOI: 10.4236/ojn.2013.32039
Abstract:

Aims and objectives: To evaluate the effectiveness of a patient education tool (the ENAT) on self efficacy, patient knowledge, health outcomes and its usability in practice. Background: The effectiveness and value of patient education in rheumatoid arthritis have been questioned. The ENAT was developed to help the nurses to provide more focused, individualized and relevant education. The psychometric properties of the ENAT have been assessed. Design: This study is a single blind randomized controlled trial using both quantitative and qualitative methodology. The primary outcome is patient self efficacy. Secondary outcomes are physical function, psychological status, pain levels, social interaction and patient knowledge of disease. Methods: 130 RA patients will be randomized into an experimental (EG) or control group (CG). The EG patients will complete the ENAT prior to seeing a Clinical Nurse Specialist (CNS) at weeks 0, 16 and 32. The CNS will use the ENAT as a template to meet patients perceived educational needs in addition to the usual care. The CG will receive their usual care from the CNS without the aid of the ENAT. To determine the ENAT’s usability, semi-structured quailtative interviews will take place with the practitioners and a sample of patients once they have completed the quantitative arm of the study. Results: The study commenced in April 2011 and the results are expected to be available after April 2013. Conclusions: It is hypothesized that nurses’ use of the ENAT will lead to increased patient self efficacy, and improved patient knowledge and health outcomes among the patients who used it. Furthermore, it is hypothesized that the ENAT will be easy for staff and patients to use. Relevance to clinical practice: The ENAT was developed to assess the perceived educational needs of patients with rheumatoid

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