63,981 Works

TLR5-Mediated Sensing of Gut Microbiota Is Necessary for Antibody Responses to Seasonal Influenza Vaccination

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Systems biological analysis of immunity to the trivalent inactivated influenza vaccine (TIV) in humans revealed a correlation between early expression of TLR5 and the magnitude of the antibody response. Vaccination of Trl5−/− mice resulted in reduced antibody titers and lower frequencies of plasma cells, demonstrating a role for TLR5 in immunity to TIV. This was due to a failure to sense host microbiota. Thus, antibody responses in germ-free or antibiotic-treated mice were impaired, but restored...

T Follicular Helper Cell-Dependent Clearance of a Persistent Virus Infection Requires T Cell Expression of the Histone Demethylase UTX

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Epigenetic changes, including histone methylation, control T cell differentiation and memory formation, though the enzymes that mediate these processes are not clear. We show that UTX, a histone H3 lysine 27 (H3K27) demethylase, supports T follicular helper (Tfh) cell responses that are essential for B cell antibody generation and the resolution of chronic viral infections. Mice with a T cell-specific UTX deletion had fewer Tfh cells, reduced germinal center responses, lacked virus-specific immunoglobulin G (IgG),...

Man's best friend: what can pet dogs teach us about non-Hodgkin's lymphoma?

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Animal models are essential for understanding lymphoma biology and testing new treatments prior to human studies. Spontaneously arising lymphomas in pet dogs represent an underutilized resource that could be used to complement current mouse lymphoma models, which do not adequately represent all aspects of the human disease. Canine lymphoma resembles human lymphoma in many important ways, including characteristic translocations and molecular abnormalities and similar therapeutic responses to chemotherapy, radiation, and newer targeted therapies (e.g. ibrutinib)....

Comparing traditional and participatory dissemination of a shared decision making intervention (ADAPT-NC): a cluster randomized trial

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BackgroundAsthma is a common disease that affects people of all ages and has significant morbidity and mortality. Poor outcomes and health disparities related to asthma result in part from the difficulty of disseminating new evidence and care delivery methods such as shared decision making (SDM) into clinical practice.This 3-year study explores the ideal framework for rapid dissemination of an evidence-based SDM toolkit for asthma management. The study leverages a partnership between the North Carolina (NC)...

Automatic classification of communication logs into implementation stages via text analysis

Abstract Background To improve the quality, quantity, and speed of implementation, careful monitoring of the implementation process is required. However, some health organizations have such limited capacity to collect, organize, and synthesize information relevant to its decision to implement an evidence-based program, the preparation steps necessary for successful program adoption, the fidelity of program delivery, and the sustainment of this program over time. When a large health system implements an evidence-based program across multiple sites,...

Parents’ differential susceptibility to the effects of marital quality on sensitivity across the first year

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The current investigation examined the differential susceptibility of parents to the effects of marital quality on changes in parenting. We predicted that parents who were high on the personality constructs Negative Affect and Constraint would be more susceptible to the effects of marital quality on their level of sensitivity. Sensitivity was assessed at 3.5 and 13 months for both mothers and fathers during a triadic interaction. Consistent with the differential susceptibility theory, results suggested that...

Modeling multiple risks during infancy to predict quality of the caregiving environment: Contributions of a person-centered approach

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The primary goal of this study was to compare several variable-centered and person-centered methods for modeling multiple risk factors during infancy to predict the quality of caregiving environments at six months of age. Nine risk factors related to family demographics and maternal psychosocial risk, assessed when children were two months old, were explored in the understudied population of children born in low-income, non-urban communities in Pennsylvania and North Carolina (N = 1047). These risk factors...

PROMOTING SUPPORTIVE PARENTING IN NEW MOTHERS WITH SUBSTANCE-USE PROBLEMS: A PILOT RANDOMIZED TRIAL OF RESIDENTIAL TREATMENT PLUS AN ATTACHMENT-BASED PARENTING PROGRAM: Residential Treatment and Attachment

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This pilot randomized trial tested the feasibility and efficacy of supplementing residential substance-abuse treatment for new mothers with a brief, yet rigorous, attachment-based parenting program. Twenty-one predominantly (86%) White mothers and their infants living together in residential substance-abuse treatment were randomly assigned to the program (n = 11) or control (n = 10) group. Program mothers received 10 home-based sessions of Dozier’s Attachment and Biobehavioral Catch-up (ABC) intervention. Postintervention observations revealed more supportive parenting behaviors...

Phospholipase B in the Brains and Meninges of Nonsensitized and Sensitized Rats After Challenge with Angiostrongylus cantonensis

After a primary infection with 100 Angiostrongylus cantonensis larvae, infected rats showed elevated phospholipase B activity in meningeal and brain homogenates beginning with the first week and continuing through the first month of infection. The rise in phospholipase B values through the first 4 weeks, with a prolonged peak spanning days 30 to 31, coincided with the invasion and maturation of the parasites in the brain, and the ensuing sharp decline in phospholipase B levels,...

Surface Characterization of Virulent Treponema pallidum

Characterization of the surface of Treponema pallidum was accomplished by [(125)I]lactoperoxidase-catalyzed iodination of intact organisms and sensitive radioimmunoprecipitation and gel electrophoresis technology. At least 11 outer membrane proteins with molecular weights ranging from 89,000 (89K) to 20K were identified, and all elicited high titers of antibody in experimentally infected rabbits. Proteins of 89.5K, 29.5K, and 25.5K previously implicated as ligands involved in attachment (J. B. Baseman and E. C. Hayes, J. Exp. Med. 151:573-586, 1980)...

Ultrastructural observations on cellular and subcellular aspects of experimental Mycoplasma pneumoniae disease.

The ultrastructural organization of Mycoplasma pneumoniae membranes and spatial relationships of this pathogen to epithelial cells in tracheal organ cultures were examined ultrastructurally by freeze-fracture techniques. Areas of morphologically distinct cell membrane variability characterized by membrane blebs and altered distributions of membrane associated particles were observed in replicas of M. pneumoniae cells. Inspection of the host tracheal epithelium demonstrated the alignment of M. pneumoniae to the epithelium with an accompanying deterioration in the integrity of...

Genetics of Serum Resistance in Neisseria gonorrhoeae: The sac-1 Genetic Locus

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A genetic locus affecting susceptibility to the bactericidal activity of normal human serum has been designated sac-1. This locus was shown to be closely linked to, but not identical with, a second locus (designated nmp-2) that affects protein 1 of the outer membrane. The sac-1 locus could be linked to known antibiotic resistance markers on the gonococcal chromosome by genetic transformation.

Effects of immunosuppression with cyclophosphamide on acute murine cytomegalovirus infection and virus-augmented natural killer cell activity.

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The effects of cyclophosphamide (CY) treatment on acute murine cytomegalovirus (MCMV) infection were studied to explore the potential usefulness of MCMV as a means of detecting immune dysfunction and to identify host defense mechanisms important for protection against MCMV. Conditions found optimal for enhancing MCMV infection with CY included infecting adult mice with 2 X 10(5) PFU or more of virus and administering 80 mg or more of CY per kg 1 to 3 days...

Gonococci with mutations to low-level penicillin resistance exhibit increased sensitivity to the oxygen-independent bactericidal activity of human polymorphonuclear leukocyte granule extracts.

Gonococci which cause disseminated gonococcal infection are nearly always highly penicillin sensitive, in contrast to many isolates causing uncomplicated gonorrhea. We questioned whether any of the known chromosomal mutations to low-level penicillin resistance might adversely affect virulence. The penA2 locus is known to result in low-level resistance to penicillins, whereas mtr-2 results in nonspecific resistance to a variety of antimicrobial agents. We found that the penA2 and mtr-2 mutations each markedly increased sensitivity of strain...

Human endothelial cell culture plaques induced by Rickettsia rickettsii.

Primary cultures of human umbilical vein endothelial cells were inoculated with plaque-purified Rickettsia rickettsii. After adsorption of rickettsiae, monolayers were overlaid with medium containing 0.5% agarose. Small plaques appeared on day 4 postinoculation, and distinct 1- to 2-mm plaques were observed on day 5. Plaquing efficiency was less than that of primary chicken embryo cells in the same medium. Human endothelial cell monolayers were susceptible to infection by R. rickettsii and underwent necrosis as demonstrated...

Identification of Mycoplasma pneumoniae proteins associated with hemadsorption and virulence.

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Twenty-two mutants of Mycoplasma pneumoniae spontaneously deficient in hemadsorption were isolated. Examination of mutant protein profiles by one- and two-dimensional polyacrylamide gel electrophoresis permitted the grouping of these mutants into four classes. The largest class of mutants was deficient in four high-molecular-weight proteins (215,000, 210,000, 190,000, and 140,000). A second class of mutants lacked three proteins previously designated A, B, and C (72,000, 85,000, and 37,000, respectively). A single mutant, in addition to lacking proteins...

Immunoglobulin M and G antibody response to type- and subtype-specific antigens after primary and secondary exposures of mice to influenza A viruses.

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A mouse model of influenza infection was studied to help define parameters that may affect serodiagnosis of human infections by immunoassays. Antibodies to both type- and subtype-specific influenza A antigens were measured by a solid-phase immunofluorometric assay. Dilute mouse sera were added to purified influenza virus that had been covalently bound to polyaminostyrene microbeads, and the bound antibody was detected by fluorescein isothiocyanate-labeled isotype-specific antisera. Results were consistent in that upon exposure of mice by...

Characterization of Neisseria gonorrhoeae protein II phase variation by use of monoclonal antibodies.

L'étude des protéines des membranes externes (PII) de N. gonorrhoeae comporte l'analyse des paramètres suivants: 1) les anticorps monoclonaux spécifiques pour les protéines PII; 2) la démonstration de la variation de phase par la méthode «colonyblat» et 3) analyse de l'expression de la protéine PII par l'activité bactéricide des anticorps monoclonaux.

Elementary Body Envelopes from Chlamydia psittaci Can Induce Immediate Cytotoxicity in Resident Mouse Macrophages and L-Cells

Isolated, purified Chlamydia psittaci elementary body envelopes at a high multiplicity of infection (1,000:1) are capable of inducing immediate cytotoxicity in resident mouse macrophages and 929 L-cells.

Arthropathic properties of cell wall polymers from normal flora bacteria.

Peptidoglycan-polysaccharide (PG-PS) fragments were purified from cell walls of group D streptococci (Streptococcus faecium, strains ATCC 9790 and F-24) with a protocol which minimizes autolytic activity and tested for ability to induce arthritis in rats. PG-PS fragments from cell walls of other normal flora bacteria (Peptostreptococcus productus, and Propionibacterium acnes), group A streptococci, and pseudomurein-PS fragments from cell walls of Methanobacterium formicicum, were similarly purified and tested. Upon intraarticular injection into rat ankles, all PG-PS...

Humoral immune response to Rocky Mountain spotted fever in experimentally infected guinea pigs: immunoprecipitation of lactoperoxidase 125I-labeled proteins and detection of soluble antigens of Rickettsia rickettsii.

Rickettsia rickettsii, the etiologic agent of Rocky Mountain spotted fever, purified from infected L-929 cells by density gradient banding were extrinsically radioiodinated with lactoperoxidase. Immunodominant 125I-labeled antigens were identified by radioimmunoprecipitation of detergent-solubilized antigens with protein A-Sepharose and anti-R. rickettsii sera collected 0, 3, 7, 11, 32, and 163 days after infection of guinea pigs. The average fever greater than or equal to 40 degrees C was detected by days 3 and 4 after infection...

Localized gut-associated lymphoid tissue hemorrhage induced by intravenous peptidoglycan-polysaccharide polymers.

A hemorrhage into gut-associated lymphoid tissue developed as early as 3 min after the intravenous injection of group A streptococcal peptidoglycan-polysaccharide polymers into rats. Extravasated erythrocytes were specifically located in the lamina propria and organized lymphoid follicles of the intestines and mesenteric lymph nodes and did not occur in the lungs, kidneys, liver, spleen, adrenal glands, or submandibular and popliteal lymph nodes, as determined by gross and histologic observations and measurement of radiolabeled erythrocytes. Petechial...

Changes in the cell surface properties of Treponema pallidum that occur during in vitro incubation of freshly extracted organisms.

We previously reported that a number of Treponema pallidum membrane proteins appear to reside on the cell surface, since intact treponemes radiolabeled by overnight incubation in medium containing [35S]methionine bind immunoglobulin G (IgG) antibodies directed against these proteins. In the present study, it was found that freshly extracted organisms radiolabeled in vitro for only 2 h inefficiently bound IgG antibodies directed against just two proteins of molecular weights 40,000 and 34,000. An in vitro incubation...

Distribution of specific DNA sequences among pathogenic and commensal Neisseria species.

Several traits, including pili and the outer membrane proteins P.II and H.8, have been associated with pathogenic Neisseria species. We examined several Neisseria species for DNA sequence homology to cloned pilin, P.II, and H.8 genes. Strains of Neisseria gonorrhoeae and N. meningitidis showed hybridization to all of these genes. Commensal strains showed little hybridization to any of these genes. Strains of N. lactamica and N. cinerea showed intermediate patterns of hybridization. Generally, organisms that expressed...

Effect of acetylation on arthropathic activity of group A streptococcal peptidoglycan-polysaccharide fragments.

Purified group A streptococcal peptidoglycan-polysaccharide (PG-PS) fragments were either de-O-acylated, or acetylated and then de-O-acylated to yield N-acetylated PG-PS. Native PG-PS was poorly degraded, N-acetylated PG-PS was extensively degraded, and de-O-acylated PG-PS was only slightly degraded by hen egg white lysozyme. N-acetylated PG-PS was also extensively degraded by human lysozyme and partially degraded by rat serum or rat liver extract. After a single intraperitoneal injection of rats with a sterile, aqueous suspension, all PG-PS preparations...

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