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Found 37684 matches. Displaying 5021-5030
Grant AB, Seixas A, Frederickson K, Butler M, Tobin JN, Jean-Louis G, Ogedegbe G
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Effect of Expectation of Care on Adherence to Antihypertensive Medications Among Hypertensive Blacks: Analysis of the Counseling African Americans to Control Hypertension (CAATCH) Trial

JOURNAL OF CLINICAL HYPERTENSION 2016 JUL; 18(7):690-696
Novel ideas are needed to increase adherence to antihypertensive medication. The current study used data from the Counseling African Americans to Control Hypertension (CAATCH) study, a sample of 442 hypertensive African Americans, to investigate the mediating effects of expectation of hypertension care, social support, hypertension knowledge, and medication adherence, adjusting for age, sex, number of medications, diabetes, education, income, employment, insurance status, and intervention. Sixty-six percent of patients had an income of $20,000 or less and 56% had a high school education or less, with a mean age of 57 years. Greater expectation of care was associated with greater medication adherence (P=.007), and greater social support was also associated with greater medication adherence (P=.046). Analysis also showed that expectation of care mediated the relationship between hypertension knowledge and medication adherence (P<.05). Expectation of care and social support are important factors for developing interventions to increase medication adherence among blacks.
Yanagida A, Mizuno N, Yamazaki Y, Kato-Itoh M, Umino A, Sato H, Ito K, Yamaguchi T, Nakauchi H, Kamiya A
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Investigation of bipotent differentiation of hepatoblasts using inducible diphtheria toxin receptor-transgenic mice

HEPATOLOGY RESEARCH 2016 JUL; 46(8):816-828
Aim: Hepatic progenitor cells, called hepatoblasts, are highly proliferative and exhibit bipotential differentiation into hepatocytes and cholangiocytes in the fetal liver. Thus, they are the ideal source for transplantation therapy. Although several studies have been performed in vitro, the molecular mechanisms regulating hepatoblast differentiation in vivo following transplantation remain poorly understood. The aim of this study was to investigate an in vivo model to analyze hepatoblast bipotency and proliferative ability. Methods: Hepatic transplantation model using Cre-inducible diphtheria toxin receptor-transgenic mice (iDTR), and albafpCre mice expressing Cre under the control of albumin and a-fetoprotein (AFP) regulatory elements were established. Fresh hepatoblasts were transplanted into diphtheria toxin (DT)-injected iDTRalbafpCre mice and we analyzed their differentiation and proliferation abilities by immunostaining and gene expression profiles. Results: Fresh hepatoblasts transplanted into DT-injected iDTRalbafpCre mice engrafted and differentiated into both hepatocytes and cholangiocytes. Additionally, the number of engrafted hepatoblast-derived hepatocytes increased following partial hepatectomy and serial DT injections. Expression levels of hepatic functional genes in transplanted hepatoblastderived hepatocytes were similar to that of normal hepatocytes. Conclusion: In our iDTRalbafpCre transplantation model, fresh hepatoblasts could differentiate into hepatocytes and cholangiocytes. In addition, these donor cells were induced to proliferate by the following liver injury stimulation. This result suggests that this model is valuable for investigating hepatoblast differentiation pathways in vivo.
Yale K, Tackett AJ, Neuman M, Bulley E, Chait BT, Wiley E
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Phosphorylation-Dependent Targeting of Tetrahymena HP1 to Condensed Chromatin

MSPHERE 2016 JUL-AUG; 1(4):? Article e00142-16
The evolutionarily conserved proteins related to heterochromatin protein 1 (HP1), originally described in Drosophila, are well known for their roles in heterochromatin assembly and gene silencing. Targeting of HP1 proteins to specific chromatin locales is mediated, at least in part, by the HP1 chromodomain, which binds to histone H3 methylated at lysine 9 that marks condensed regions of the genome. Mechanisms that regulate HP1 targeting are emerging from studies with yeast and metazoans and point to roles for posttranslational modifications. Here, we report that modifications of an HP1 homolog (Hhp1) in the ciliate model Tetrahymena thermophila correlated with the physiological state and with nuclear differentiation events involving the restructuring of chromatin. Results support the model in which Hhp1 chromodomain binds lysine 27-methylated histone H3, and we show that colocalization with this histone mark depends on phosphorylation at a single Cdc2/Cdk1 kinase site in the "hinge region" adjacent to the chromodomain. These findings help elucidate important functional roles of reversible posttranslational modifications of proteins in the HP1 family, in this case, regulating the targeting of a ciliate HP1 to chromatin regions marked with methylated H3 lysine 27. IMPORTANCE Compacting the genome to various degrees influences processes that use DNA as a template, such as gene transcription and replication. This project was aimed at learning more about the cellular mechanisms that control genome compaction. Posttranslational modifications of proteins involved in genome condensation are emerging as potentially important points of regulation. To help elucidate protein modifications and how they affect the function of condensation proteins, we investigated the phosphorylation of the chromatin protein called Hhp1 in the ciliated protozoan Tetrahymena thermophila. This is one of the first functional investigations of these modifications of a nonhistone chromatin condensation protein that acts on the ciliate genome, and discoveries will aid in identifying common, evolutionarily conserved strategies that control the dynamic compaction of genomes.
Leven EA, Maffucci P, Ochs HD, Scholl PR, Buckley RH, Fuleihan RL, Geha RS, Cunningham CK, Bonilla FA, Conley ME, Ferdman RM, Hernandez-Trujillo V, Puck JM, Sullivan K, Secord EA, Ramesh M, Cunningham-Rundles C
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Hyper IgM Syndrome: a Report from the USIDNET Registry

JOURNAL OF CLINICAL IMMUNOLOGY 2016 JUL; 36(5):490-501
The United States Immunodeficiency Network (USIDNET) patient registry was used to characterize the presentation, genetics, phenotypes, and treatment of patients with Hyper IgM Syndrome (HIGM). The USIDNET Registry was queried for HIGM patient data collected from October 1992 to July 2015. Data fields included demographics, criteria for diagnosis, pedigree analysis, mutations, clinical features, treatment and transplant records, laboratory findings, and mortality. Fifty-two physicians entered data from 145 patients of ages 2 months to 62 years (median 12 years); 131 were males. Using patients' age at last entry, data from 2072 patient years are included. Mutations were recorded for 85 subjects; 82 were in CD40LG. Eighteen subjects had non-X-linked HIGM. 40 % had a normal serum IgM and 15 %, normal IgA. Infections were reported for 91 %, with pulmonary, ear, and sinus infections being the most common. 42 % had Pneumocystis jirovecii pneumonia; 6 % had Cryptosporidium. 41 % had neutropenia. 78 % experienced non-infectious complications: chronic diarrhea (n = 22), aphthous ulcers (n = 28), and neoplasms (n = 8) including colon cancer, adrenal adenoma, liver adenocarcinoma, pancreatic carcinoid, acute myeloid leukemia, hepatoma, and, in a female with an autosomal dominant gain of function mutation in PIK3CD, an ovarian dysgerminoma. Thirteen patients had a hematopoietic marrow or stem cell transplant; three had solid organ transplants. Thirteen were known to have died (median age = 14 years). Analysis of the USIDNET Registry provides data on the common clinical features of this rare syndrome, and in contrast with previously published data, demonstrates longer survival times and reduced gastrointestinal manifestations.
Kushnir VA, Darmon SK, Albertini DF, Barad DH, Gleicher N
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Effectiveness of in vitro fertilization with preimplantation genetic screening: a reanalysis of United States assisted reproductive technology data 2011-2012

FERTILITY AND STERILITY 2016 JUL; 106(1):75-79
Objective: To assess effectiveness of preimplantation genetic screening (PGS) in fresh IVF cycles. Design: Reanalysis of retrospective US national data. Setting: Not applicable. Patient(s): A total of 5,471 fresh autologous IVF cycles with PGS and 97,069 cycles without PGS, reported in 2011-2012 to the Centers for Disease Control and Prevention. Intervention(s): Not applicable. Main Outcome Measure(s): Cycles that reached ET, miscarriage rates, live birth rates per cycle and per transfer. Result(s): More PGS than non-PGS cycles reached ET (64.2% vs. 62.3%), suggesting favorable patient selection bias for patients using PGS. Nevertheless, live births rates per cycle start (25.2% vs. 28.8%) and per ET (39.3% vs. 46.2%) were significantly better in non-PGS cycles, whereas miscarriage rates were similar (13.7% vs. 13.9%). With a maternal age > 37 years significantly more cycles in the PGS group reached ET (53.1% vs. 41.9%), suggesting a significant selection bias for more favorable patients in the PGS population. This bias rather than the PGS procedure may partially explain the observed improved live birth rate per cycle (17.7% vs. 12.7%) and lower miscarriage rate (16.8% vs. 26.0%) in the older PGS group. Conclusion(s): Overall, PGS decreased chances of live birth in association with IVF. National improvements in live birth and miscarriage rates reported with PGS in older women are likely the consequence of favorable patient selection biases. (C) 2016 by American Society for Reproductive Medicine.
Valente C, Hinds J, Gould KA, Pinto FR, de Lencastre H, Sa-Leao R
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Impact of the 13-valent pneumococcal conjugate vaccine on Streptococcus pneumoniae multiple serotype carriage

VACCINE 2016 JUL 25; 34(34):4072-4078
Introduction: Pneumococcal multiple serotype carriage is important for evolution of the species and to understand how the pneumococcal population is changing with vaccination. We aimed to determine the impact of the 13-valent pneumococcal conjugate vaccine (PCV13) on multiple serotype carriage. Methods and materials: Nasopharyngeal samples from fully vaccinated pneumococcal carriers (4 doses of PCV13, n = 141, aged 18-72 months) or from non-vaccinated pneumococcal carriers (0 doses of any PCV, n = 140, same age group) were analyzed. Multiple serotype carriage was evaluated by DNA hybridization with a molecular serotyping microarray that detects all known serotypes. Results: Vaccinated children had a lower prevalence of multiple serotype carriage than the non vaccinated group (20.6% vs 29.3%, p = 0.097), and a significantly lower proportion of PCV13 serotypes (6.4% vs 38.5%, p = 0.0001). PCV13 serotypes found among vaccinated children were mostly detected as a minor serotype in co-colonization with a more abundant non-vaccine serotype. Vaccinated children were colonized by a significantly higher proportion of commensal non-pneumococcal Streptococcus spp. (58.2% vs 42.8%, p = 0.012). In vaccinated children there were significantly less non-vaccine type (NVT) co-colonization events than expected based on the distribution of these serotypes in non vaccinated children. Conclusions: The results suggest that vaccinated children have lower pneumococcal multiple serotype carriage prevalence due to higher competitive abilities of non-vaccine serotypes expanding after PCV13 use. This might represent an additional benefit of PCV13, as decreased co-colonization rates translate into decreased opportunities for horizontal gene transfer and might have implications for the evolution and virulence of pneumococci. (C) 2016 Elsevier Ltd. All rights reserved.
Dar RD, Shaffer SM, Singh A, Razooky BS, Simpson ML, Raj A, Weinberger LS
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Transcriptional Bursting Explains the Noise-Versus-Mean Relationship in mRNA and Protein Levels

PLOS ONE 2016 JUL 28; 11(7):? Article e0158298
Recent analysis demonstrates that the HIV-1 Long Terminal Repeat (HIV LTR) promoter exhibits a range of possible transcriptional burst sizes and frequencies for any mean-expression level. However, these results have also been interpreted as demonstrating that cell-tocell expression variability (noise) and mean are uncorrelated, a significant deviation from previous results. Here, we re-examine the available mRNA and protein abundance data for the HIV LTR and find that noise in mRNA and protein expression scales inversely with the mean along analytically predicted transcriptional burst-sizemanifolds. We then experimentally perturb transcriptional activity to test a prediction of the multiple burst-size model: that increasing burst frequency will cause mRNA noise to decrease along given burst-size lines as mRNA levels increase. The data show that mRNA and protein noise decrease as mean expression increases, supporting the canonical inverse correlation between noise and mean.
Su Y, Xia W, Li J, Walz T, Humphries MJ, Vestweber D, Cabanas C, Lu CF, Springer TA
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Relating conformation to function in integrin alpha(5)beta(1)

PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA 2016 JUL 5; 113(27):E3872-E3881
Whether beta(1) integrin ectodomains visit conformational states similarly to beta(2) and beta(3) integrins has not been characterized. Furthermore, despite a wealth of activating and inhibitory antibodies to beta(1) integrins, the conformational states that these antibodies stabilize, and the relation of these conformations to function, remain incompletely characterized. Using negative-stain electron microscopy, we show that the integrin alpha(5)beta(1) ectodomain adopts extended-closed and extended-open conformations as well as a bent conformation. Antibodies SNAKA51, 8E3, N29, and 9EG7 bind to different domains in the alpha(5) or beta(1) legs, activate, and stabilize extended ectodomain conformations. Antibodies 12G10 and HUTS-4 bind to the beta(1) beta I domain and hybrid domains, respectively, activate, and stabilize the open headpiece conformation. Antibody TS2/16 binds a similar epitope as 12G10, activates, and appears to stabilize an open beta I domain conformation without requiring extension or hybrid domain swing-out. mAb13 and SG/19 bind to the beta I domain and beta I-hybrid domain interface, respectively, inhibit, and stabilize the closed conformation of the headpiece. The effects of the antibodies on cell adhesion to fibronectin substrates suggest that the extended-open conformation of alpha(5)beta(1) is adhesive and that the extended-closed and bent-closed conformations are nonadhesive. The functional effects and binding sites of antibodies and fibronectin were consistent with their ability in binding to alpha(5)beta(1) on cell surfaces to cross-enhance or inhibit one another by competitive or noncompetitive (allosteric) mechanisms.
McEwen BS, McEwen CA
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Response to Jerome Kagan's Essay on Stress (2016)

PERSPECTIVES ON PSYCHOLOGICAL SCIENCE 2016 JUL; 11(4):451-455
To be useful, the concept of stress needs to be defined in biological terms linked to a broader framework of allostasis and its role in the adaptation of brain and body to positive and negative life experiences. A clear biological framework helps connect and organize animal and human research on stress. In particular, the concepts of toxic stress and allostatic load and overload highlight those experiences and situations that, as Kagan says, compromise an organism's health and capacity to cope with daily challenges (p. 442). A deeper understanding is needed of the epigenetic influences throughout the life course that contribute both to these negative outcomes and to positive ones.
Tinsley JN, Molodtsov MI, Prevedel R, Wartmann D, Espigule-Pons J, Lauwers M, Vaziri A
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Direct detection of a single photon by humans

Nature Communications 2016 JUL; 7(?):? Article 12172
Despite investigations for over 70 years, the absolute limits of human vision have remained unclear. Rod cells respond to individual photons, yet whether a single-photon incident on the eye can be perceived by a human subject has remained a fundamental open question. Here we report that humans can detect a single-photon incident on the cornea with a probability significantly above chance. This was achieved by implementing a combination of a psychophysics procedure with a quantum light source that can generate single-photon states of light. We further discover that the probability of reporting a single photon is modulated by the presence of an earlier photon, suggesting a priming process that temporarily enhances the effective gain of the visual system on the timescale of seconds.