53 research outputs found

    MADAM Protein Decreases Microsporidia Attachment to Host Cells

    Get PDF
    Microsporidia are an obligate, intracellular fungal pathogen that can cause devastating, disseminating infections in the immunocompromised. Because of the limitations of current medications, microsporidia’s abundant presence in the environment, and an increasing number of at-risk populations, investigation into decreasing microsporidia infectivity is needed. As an intracellular pathogen, microspridial attachment is a vital first step to infection, and if attachment is reduced, previous work shows that infectivity is mitigated. An in silico analysis of Encephalitozoon intestinalis revealed a predicted protein similar in sequence to ADAM (A Disintegrin And Metalloproteinase) proteins. This predicted protein is termed microsporidia ADAM or MADAM. ADAM proteins contain an integrin binding region, which is well known to bind to integrin proteins. Integrins are important receptors for attachment and cell signaling, and several pathogens utilize host integrins as a receptor to aid in attachment during infection. Immunoelectron microscopy demonstrates that MADAM protein is found on the plasma membrane, anchoring disk, and polar tube of E. intestinalis spores. Our hypothesis is that MADAM is involved in the key role of host cell attachment. To this end, a 17 amino acid long section of the MADAM protein was generated that surrounded the integrin binding domain. During spore adherence assays, pretreating host cells with this small peptide protein, significantly decreased E. intestinalis spore attachment to host cells as compared to control samples. These results suggest E. intestinalis cleverly exploits host integrins as a means to bind to host cells before infection

    Supplemental Data

    Get PDF

    Pulmonary artery interventions after Norwood procedure: Does type or position of shunt predict need for intervention?

    Get PDF
    ObjectivesPulmonary artery stenosis is a potential complication after Norwood palliation for hypoplastic left heart syndrome. It is unclear whether the shunt type or position in the Norwood procedure is associated with the risk of the development of pulmonary artery stenosis. We examined the risk of pulmonary artery stenosis and the need for pulmonary artery intervention in children undergoing the Norwood procedure with either the right ventricle to pulmonary artery conduit or modified Blalock-Taussig shunt.MethodsA retrospective review was performed of all patients who underwent the Norwood procedure from January 1, 2003, to September 1, 2011. The data from 100 patients were reviewed, including catheterization and echocardiographic data, right ventricle to pulmonary artery conduit (n = 67, right shunt position in 17 and left in 50), and right ventricle to pulmonary artery (n = 33). The primary outcome measure was the need for operative or catheter-based pulmonary artery intervention.ResultsNo patients in the right ventricle to pulmonary artery group required catheterization-based pulmonary artery interventions. Surgical pulmonary arterioplasty was performed frequently and equally in both the right ventricle to pulmonary artery and right ventricle to pulmonary artery groups at the bidirectional Glenn procedure. Catheter-based pulmonary arterioplasty was performed more frequently in the right ventricle to pulmonary artery conduit group, especially when the conduit was positioned to the right side of the neoaorta. These patients had a 12.73 increased odds of a pulmonary artery intervention compared with the left to right ventricle to pulmonary artery conduit (P = .04).ConclusionsConsistent with a previous multicenter randomized trial, patients who received a right ventricle to pulmonary artery conduit versus a right ventricle to pulmonary artery have a greater risk of requiring pulmonary artery interventions. Patients with right ventricle to pulmonary artery conduit placement to the right underwent a greater number of pulmonary artery interventions but demonstrated overall improved growth of the branch pulmonary arteries compared with the patients receiving a left-sided right ventricle to pulmonary artery conduit

    Extracorporeal membrane oxygenation support after the Fontan operation

    Get PDF
    ObjectiveExtracorporeal membrane oxygenation has been used to support children with cardiac failure after the Fontan operation. Mortality is high, and causes of mortality remain unclear. We evaluated the in-hospital mortality and factors associated with mortality in these patients.MethodsExtracorporeal Life Support Organization registry data on patients requiring extracorporeal membrane oxygenation after the Fontan operation from 1987 to 2009 were retrospectively analyzed. Demographics and extracorporeal membrane oxygenation data were compared for survivors and nonsurvivors. A multivariable logistic regression model was used to identify factors associated with mortality.ResultsOf 230 patients, 81 (35%) survived to hospital discharge. Cardiopulmonary resuscitation was more frequent (34% vs 17%, P = .04), and median fraction of inspired oxygen concentration was higher (1 [confidence interval, 0.9–1.0] vs 0.9 [confidence interval, 0.8–1.0], P = .03) before extracorporeal membrane oxygenation in nonsurvivors compared with survivors. Extracorporeal membrane oxygenation duration and incidence of complications, including surgical bleeding, neurologic injury, renal failure, inotrope use on extracorporeal membrane oxygenation, and bloodstream infection, were higher in nonsurvivors compared with survivors (P < .05 for all). In a multivariable model, neurologic injury (odds ratio, 5.18; 95% confidence interval, 1.97–13.61), surgical bleeding (odds ratio, 2.36; 95% confidence interval, 1.22–4.56), and renal failure (odds ratio, 2.81; 95% confidence interval, 1.41–5.59) increased mortality. Extracorporeal membrane oxygenation duration of more than 65 hours to 119 hours (odds ratio, 0.33; 95% confidence interval, 0.14–0.76) was associated with decreased mortality.ConclusionsCardiac failure requiring extracorporeal membrane oxygenation after the Fontan operation is associated with high mortality. Complications during extracorporeal membrane oxygenation support increase mortality odds. Prompt correction of surgical bleeding when possible may improve survival

    Antimicrobial Resistance among Campylobacter Strains, United States, 1997–2001

    Get PDF
    We summarize antimicrobial resistance surveillance data in human and chicken isolates of Campylobacter. Isolates were from a sentinel county study from 1989 through 1990 and from nine state health departments participating in National Antimicrobial Resistance Monitoring System for enteric bacteria (NARMS) from 1997 through 2001. None of the 297 C. jejuni or C. coli isolates tested from 1989 through 1990 was ciprofloxacin-resistant. From 1997 through 2001, a total of 1,553 human Campylobacter isolates were characterized: 1,471 (95%) were C. jejuni, 63 (4%) were C. coli, and 19 (1%) were other Campylobacter species. The prevalence of ciprofloxacin-resistant Campylobacter was 13% (28 of 217) in 1997 and 19% (75 of 384) in 2001; erythromycin resistance was 2% (4 of 217) in 1997 and 2% (8 of 384) in 2001. Ciprofloxacin-resistant Campylobacter was isolated from 10% of 180 chicken products purchased from grocery stores in three states in 1999. Ciprofloxacin resistance has emerged among Campylobacter since 1990 and has increased in prevalence since 1997

    Clofazimine pharmacokinetics in HIV‐infected adults with diarrhea: Implications of diarrheal disease on absorption of orally administered therapeutics

    Get PDF
    Oral drug absorption kinetics are usually established in populations with a properly functioning gastrointestinal tract. However, many diseases and therapeutics can alter gastrointestinal physiology and cause diarrhea. The extent of diarrhea‐associated impact on drug pharmacokinetics has not been quantitatively described. To address this knowledge gap, we used a population pharmacokinetic modeling approach with data collected in a phase IIa study of matched human immunodeficiency virus (HIV)–infected adults with/without cryptosporidiosis and diarrhea to examine diarrhea‐associated impact on oral clofazimine pharmacokinetics. A population pharmacokinetic model was developed with 428 plasma samples from 23 HIV‐infected adults with/without Cryptosporidium infection using nonlinear mixed‐effects modeling. Covariates describing cryptosporidiosis‐associated diarrhea severity (e.g., number of diarrhea episodes, diarrhea grade) or HIV infection (e.g., viral load, CD4+ T cell count) were evaluated. A two‐compartment model with lag time and first‐order absorption and elimination best fit the data. Maximum diarrhea grade over the study duration was found to be associated with a more than sixfold reduction in clofazimine bioavailability. Apparent clofazimine clearance, intercompartmental clearance, central volume of distribution, and peripheral volume of distribution were 3.71 L/h, 18.2 L/h (interindividual variability [IIV] 45.0%), 473 L (IIV 3.46%), and 3434 L, respectively. The absorption rate constant was 0.625 h−1 (IIV 149%) and absorption lag time was 1.83 h. In conclusion, the maximum diarrhea grade observed for the duration of oral clofazimine administration was associated with a significant reduction in clofazimine bioavailability. Our results highlight the importance of studying disease impacts on oral therapeutic pharmacokinetics to inform dose optimization and maximize the chance of treatment success

    Lymphatic vessel density and function in experimental bladder cancer

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>The lymphatics form a second circulatory system that drains the extracellular fluid and proteins from the tumor microenvironment, and provides an exclusive environment in which immune cells interact and respond to foreign antigen. Both cancer and inflammation are known to induce lymphangiogenesis. However, little is known about bladder lymphatic vessels and their involvement in cancer formation and progression.</p> <p>Methods</p> <p>A double transgenic mouse model was generated by crossing a bladder cancer-induced transgenic, in which SV40 large T antigen was under the control of uroplakin II promoter, with another transgenic mouse harboring a <it>lacZ </it>reporter gene under the control of an NF-ÎșB-responsive promoter (ÎșB-<it>lacZ</it>) exhibiting constitutive activity of ÎČ-galactosidase in lymphatic endothelial cells. In this new mouse model (SV40-<it>lacZ</it>), we examined the lymphatic vessel density (LVD) and function (LVF) during bladder cancer progression. LVD was performed in bladder whole mounts and cross-sections by fluorescent immunohistochemistry (IHC) using LYVE-1 antibody. LVF was assessed by real-time <it>in vivo </it>imaging techniques using a contrast agent (biotin-BSA-Gd-DTPA-Cy5.5; Gd-Cy5.5) suitable for both magnetic resonance imaging (MRI) and near infrared fluorescence (NIRF). In addition, IHC of Cy5.5 was used for time-course analysis of co-localization of Gd-Cy5.5 with LYVE-1-positive lymphatics and CD31-positive blood vessels.</p> <p>Results</p> <p>SV40-<it>lacZ </it>mice develop bladder cancer and permitted visualization of lymphatics. A significant increase in LVD was found concomitantly with bladder cancer progression. Double labeling of the bladder cross-sections with LYVE-1 and Ki-67 antibodies indicated cancer-induced lymphangiogenesis. MRI detected mouse bladder cancer, as early as 4 months, and permitted to follow tumor sizes during cancer progression. Using Gd-Cy5.5 as a contrast agent for MRI-guided lymphangiography, we determined a possible reduction of lymphatic flow within the tumoral area. In addition, NIRF studies of Gd-Cy5.5 confirmed its temporal distribution between CD31-positive blood vessels and LYVE-1 positive lymphatic vessels.</p> <p>Conclusion</p> <p>SV40-<it>lacZ </it>mice permit the visualization of lymphatics during bladder cancer progression. Gd-Cy5.5, as a double contrast agent for NIRF and MRI, permits to quantify delivery, transport rates, and volumes of macromolecular fluid flow through the interstitial-lymphatic continuum. Our results open the path for the study of lymphatic activity <it>in vivo </it>and in real time, and support the role of lymphangiogenesis during bladder cancer progression.</p

    A large genome-wide association study of age-related macular degeneration highlights contributions of rare and common variants.

    Get PDF
    This is the author accepted manuscript. The final version is available from Nature Publishing Group via http://dx.doi.org/10.1038/ng.3448Advanced age-related macular degeneration (AMD) is the leading cause of blindness in the elderly, with limited therapeutic options. Here we report on a study of >12 million variants, including 163,714 directly genotyped, mostly rare, protein-altering variants. Analyzing 16,144 patients and 17,832 controls, we identify 52 independently associated common and rare variants (P < 5 × 10(-8)) distributed across 34 loci. Although wet and dry AMD subtypes exhibit predominantly shared genetics, we identify the first genetic association signal specific to wet AMD, near MMP9 (difference P value = 4.1 × 10(-10)). Very rare coding variants (frequency <0.1%) in CFH, CFI and TIMP3 suggest causal roles for these genes, as does a splice variant in SLC16A8. Our results support the hypothesis that rare coding variants can pinpoint causal genes within known genetic loci and illustrate that applying the approach systematically to detect new loci requires extremely large sample sizes.We thank all participants of all the studies included for enabling this research by their participation in these studies. Computer resources for this project have been provided by the high-performance computing centers of the University of Michigan and the University of Regensburg. Group-specific acknowledgments can be found in the Supplementary Note. The Center for Inherited Diseases Research (CIDR) Program contract number is HHSN268201200008I. This and the main consortium work were predominantly funded by 1X01HG006934-01 to G.R.A. and R01 EY022310 to J.L.H

    The James Webb Space Telescope Mission

    Full text link
    Twenty-six years ago a small committee report, building on earlier studies, expounded a compelling and poetic vision for the future of astronomy, calling for an infrared-optimized space telescope with an aperture of at least 4m4m. With the support of their governments in the US, Europe, and Canada, 20,000 people realized that vision as the 6.5m6.5m James Webb Space Telescope. A generation of astronomers will celebrate their accomplishments for the life of the mission, potentially as long as 20 years, and beyond. This report and the scientific discoveries that follow are extended thank-you notes to the 20,000 team members. The telescope is working perfectly, with much better image quality than expected. In this and accompanying papers, we give a brief history, describe the observatory, outline its objectives and current observing program, and discuss the inventions and people who made it possible. We cite detailed reports on the design and the measured performance on orbit.Comment: Accepted by PASP for the special issue on The James Webb Space Telescope Overview, 29 pages, 4 figure

    Finishing the euchromatic sequence of the human genome

    Get PDF
    The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∌99% of the euchromatic genome and is accurate to an error rate of ∌1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead
    • 

    corecore