95 research outputs found

    Interval exercise increases angiogenic cell function in postmenopausal women

    Get PDF
    Introduction: Exercise can help to negate the increased cardiovascular disease risk observed in women after the menopausal transition. This study sought to determine whether interval or continuous exercise have differential effects on endothelial function and circulating angiogenic cell (CAC) number and function in postmenopausal women. Methods: Fifteen healthy postmenopausal women completed a 30 min acute moderate-intensity continuous (CON) and interval exercise (MOD-INT) session on a cycle ergometer on separate days. Nine participants completed a further single 30 min acute heavy-intensity interval (HEAVY-INT) exercise session. Brachial artery flow-mediated dilation (FMD) was assessed pre and 15 min post exercise session. CAC number and colony forming capacity in vitro were assessed post exercise and compared to resting levels. Results: FMD and CAC number did not change post exercise regardless of exercise type (p > 0.05). However, the number (mean ± SD) of colony forming units (CFUs) increased from visit one (12 ± 10 CFUs/well) to post MOD-INT (32 ± 30 CFUs/well) and post HEAVY-INT (38 ± 23 CFUs/well) but not post CON (13 ± 14 CFUs/well). Conclusion: A single session of interval exercise is more effective than a continuous exercise session for increasing the intercellular communication of CACs, regardless of exercise intensity. The enhanced ability of CACs to form colonies may reflect an increased number and/or function of angiogenic T-cells. The repeated exertions to higher work-rates during interval exercise may explain this response. Repeated exercise sessions might be required to improve FMD in postmenopausal women

    Predictors of persistently positive Mycobacterium-tuberculosis-specific interferon-gamma responses in the serial testing of health care workers

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Data on the performance of Mycobacterium-tuberculosis-specific interferon-(IFN)-γ release assays (IGRAs) in the serial testing of health care workers (HCWs) is limited. The objective of the present study was to determine the frequency of IGRA conversions and reversions and to identify predictors of persistent IGRA positivity among serially tested German HCWs in the absence of recent extensive tuberculosis (TB) exposure.</p> <p>Methods</p> <p>In this observational cohort-study HCWs were prospectively recruited within occupational safety and health measures and underwent a tuberculin skin test (TST) and the IGRA QuantiFERON<sup>®</sup>-TB Gold In-Tube (QFT-GIT) at baseline. The QFT-GIT was repeated 18 weeks later in the median. QFT-GIT conversions (and reversions) were defined as baseline IFN-γ < 0.35 IU/ml and follow-up IFN-γ ≥ 0.35 IU/ml (and vice versa). Predictors of persistently positive QFT-GIT results were calculated by logistic regression analysis.</p> <p>Results</p> <p>In total, 18 (9.9%) and 15 (8.2%) of 182 analyzed HCWs were QFT-GIT-positive at baseline and at follow-up, respectively. We observed a strong overall agreement between baseline and follow-up QFT-GIT results (κ = 0.70). Reversions (6/18, 33.3%) occurred more frequently than conversions (3/162, 1.9%). Age and positive prior and recent TST results independently predicted persistent QFT-GIT positivity. Furthermore, the chance of having persistently positive QFT-GIT results raised about 3% with each additional 0.1 IU/ml increase in the baseline IFN-γ response (adjusted odds ratio 1.03, 95% confidence interval 1.01-1.04). No active TB cases were detected within an observational period of more than two years.</p> <p>Conclusions</p> <p>The QFT-GIT's utility for the application in serial testing was limited by a substantial proportion of reversions. This shortcoming could be overcome by the implementation of a borderline zone for the interpretation of QFT-GIT results. However, further studies are needed to clearly define the within-subject variability of the QFT-GIT and to confirm that increasing age, concordantly positive TST results, and the extend of baseline IFN-γ responses may predict the persistence of QFT-GIT positivity over time in serially tested HCWs with only a low or medium TB screening risk in a TB low-incidence setting.</p

    How and when plume zonation appeared during the 132 Myr evolution of the Tristan Hotspot

    Get PDF
    Increasingly, spatial geochemical zonation, present as geographically distinct, subparallel trends, is observed along hotspot tracks, such as Hawaii and the Galapagos. The origin of this zonation is currently unclear. Recently zonation was found along the last B70 Myr of the Tristan-Gough hotspot track. Here we present new Sr–Nd–Pb–Hf isotope data from the older parts of this hotspot track (Walvis Ridge and Rio Grande Rise) and re-evaluate published data from the Etendeka and Parana flood basalts erupted at the initiation of the hotspot track. We show that only the enriched Gough, but not the less-enriched Tristan, component is present in the earlier (70–132 Ma) history of the hotspot. Here we present a model that can explain the temporal evolution and origin of plume zonation for both the Tristan-Gough and Hawaiian hotspots, two end member types of zoned plumes, through processes taking place in the plume sources at the base of the lower mantle

    The Protein Kinase Tor1 Regulates Adhesin Gene Expression in Candida albicans

    Get PDF
    Eukaryotic cell growth is coordinated in response to nutrient availability, growth factors, and environmental stimuli, enabling cell–cell interactions that promote survival. The rapamycin-sensitive Tor1 protein kinase, which is conserved from yeasts to humans, participates in a signaling pathway central to cellular nutrient responses. To gain insight into Tor-mediated processes in human fungal pathogens, we have characterized Tor signaling in Candida albicans. Global transcriptional profiling revealed evolutionarily conserved roles for Tor1 in regulating the expression of genes involved in nitrogen starvation responses and ribosome biogenesis. Interestingly, we found that in C. albicans Tor1 plays a novel role in regulating the expression of several cell wall and hyphal specific genes, including adhesins and their transcriptional repressors Nrg1 and Tup1. In accord with this transcriptional profile, rapamycin induced extensive cellular aggregation in an adhesin-dependent fashion. Moreover, adhesin gene induction and cellular aggregation of rapamycin-treated cells were strongly dependent on the transactivators Bcr1 and Efg1. These findings support models in which Tor1 negatively controls cellular adhesion by governing the activities of Bcr1 and Efg1. Taken together, these results provide evidence that Tor1-mediated cellular adhesion might be broadly conserved among eukaryotic organisms

    Characterization, high-resolution mapping and differential expression of three homologous PAL genes in Coffea canephora Pierre (Rubiaceae)

    Get PDF
    Phenylalanine ammonia lyase (PAL) is the first entry enzyme of the phenylpropanoid pathway producing phenolics, widespread constituents of plant foods and beverages, including chlorogenic acids, polyphenols found at remarkably high levels in the coffee bean and long recognized as powerful antioxidants. To date, whereas PAL is generally encoded by a small gene family, only one gene has been characterized in Coffea canephora (CcPAL1), an economically important species of cultivated coffee. In this study, a molecular- and bioinformatic-based search for CcPAL1 paralogues resulted successfully in identifying two additional genes, CcPAL2 and CcPAL3, presenting similar genomic structures and encoding proteins with close sequences. Genetic mapping helped position each gene in three different coffee linkage groups, CcPAL2 in particular, located in a coffee genome linkage group (F) which is syntenic to a region of Tomato Chromosome 9 containing a PAL gene. These results, combined with a phylogenetic study, strongly suggest that CcPAL2 may be the ancestral gene of C. canephora. A quantitative gene expression analysis was also conducted in coffee tissues, showing that all genes are transcriptionally active, but they present distinct expression levels and patterns. We discovered that CcPAL2 transcripts appeared predominantly in flower, fruit pericarp and vegetative/lignifying tissues like roots and branches, whereas CcPAL1 and CcPAL3 were highly expressed in immature fruit. This is the first comprehensive study dedicated to PAL gene family characterization in coffee, allowing us to advance functional studies which are indispensable to learning to decipher what role this family plays in channeling the metabolism of coffee phenylpropanoids

    Change in albuminuria as a surrogate endpoint for progression of kidney disease: a meta-analysis of treatment effects in randomised clinical trials

    Get PDF
    Background Change in albuminuria has strong biological plausibility as a surrogate endpoint for progression of chronic kidney disease, but empirical evidence to support its validity is lacking. We aimed to determine the association between treatment effects on early changes in albuminuria and treatment effects on clinical endpoints and surrograte endpoints, to inform the use of albuminuria as a surrogate endpoint in future randomised controlled trials. Methods In this meta-analysis, we searched PubMed for publications in English from Jan 1, 1946, to Dec 15, 2016, using search terms including “chronic kidney disease”, “chronic renal insufficiency”, “albuminuria”, “proteinuria”, and “randomized controlled trial”; key inclusion criteria were quantifiable measurements of albuminuria or proteinuria at baseline and within 12 months of follow-up and information on the incidence of end-stage kidney disease. We requested use of individual patient data from the authors of eligible studies. For all studies that the authors agreed to participate and that had sufficient data, we estimated treatment effects on 6-month change in albuminuria and the composite clinical endpoint of treated end-stage kidney disease, estimated glomerular filtration rate of less than 15 mL/min per 1·73 m2, or doubling of serum creatinine. We used a Bayesian mixed-effects meta-regression analysis to relate the treatment effects on albuminuria to those on the clinical endpoint across studies and developed a prediction model for the treatment effect on the clinical endpoint on the basis of the treatment effect on albuminuria. Findings We identified 41 eligible treatment comparisons from randomised trials (referred to as studies) that provided sufficient patient-level data on 29 979 participants (21 206 [71%] with diabetes). Over a median follow-up of 3·4 years (IQR 2·3–4·2), 3935 (13%) participants reached the composite clinical endpoint. Across all studies, with a meta-regression slope of 0·89 (95% Bayesian credible interval [BCI] 0·13–1·70), each 30% decrease in geometric mean albuminuria by the treatment relative to the control was associated with an average 27% lower hazard for the clinical endpoint (95% BCI 5–45%; median R2 0·47, 95% BCI 0·02–0·96). The association strengthened after restricting analyses to patients with baseline albuminuria of more than 30 mg/g (ie, 3·4 mg/mmol; R2 0·72, 0·05–0·99]). For future trials, the model predicts that treatments that decrease the geometric mean albuminuria to 0·7 (ie, 30% decrease in albuminuria) relative to the control will provide an average hazard ratio (HR) for the clinical endpoint of 0·68, and 95% of sufficiently large studies would have HRs between 0·47 and 0·95. Interpretation Our results support a role for change in albuminuria as a surrogate endpoint for the progression of chronic kidney disease, particularly in patients with high baseline albuminuria; for patients with low baseline levels of albuminuria this association is less certain

    Cryptococcus neoformans Mediator Protein Ssn8 Negatively Regulates Diverse Physiological Processes and Is Required for Virulence

    Get PDF
    Cryptococcus neoformans is a ubiquitously distributed human pathogen. It is also a model system for studying fungal virulence, physiology and differentiation. Light is known to inhibit sexual development via the evolutionarily conserved white collar proteins in C. neoformans. To dissect molecular mechanisms regulating this process, we have identified the SSN8 gene whose mutation suppresses the light-dependent CWC1 overexpression phenotype. Characterization of sex-related phenotypes revealed that Ssn8 functions as a negative regulator in both heterothallic a-α mating and same-sex mating processes. In addition, Ssn8 is involved in the suppression of other physiological processes including invasive growth, and production of capsule and melanin. Interestingly, Ssn8 is also required for the maintenance of cell wall integrity and virulence. Our gene expression studies confirmed that deletion of SSN8 results in de-repression of genes involved in sexual development and melanization. Epistatic and yeast two hybrid studies suggest that C. neoformans Ssn8 plays critical roles downstream of the Cpk1 MAPK cascade and Ste12 and possibly resides at one of the major branches downstream of the Cwc complex in the light-mediated sexual development pathway. Taken together, our studies demonstrate that the conserved Mediator protein Ssn8 functions as a global regulator which negatively regulates diverse physiological and developmental processes and is required for virulence in C. neoformans

    Global report on preterm birth and stillbirth (4 of 7): delivery of interventions

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>The efficacious interventions identified in the previous article of this report will fail unless they are delivered at high and equitable coverage. This article discusses critical delivery constraints and strategies.</p> <p>Barriers to scaling up interventions</p> <p>Achieving universal coverage entails addressing major barriers at many levels. An overarching constraint is the lack of political will, resulting from the dearth of preterm birth and stillbirth data and the lack of visibility. Other barriers exist at the household and community levels, such as insufficient demand for interventions or sociocultural barriers; at the health services level, such as a lack of resources and trained healthcare providers; and at the health sector policy and management level, such as poorly functioning, centralized systems. Additional constraints involve weak governance and accountability, political instability, and challenges in the physical environment.</p> <p>Strategies and examples</p> <p>Scaling up maternal, newborn and child health interventions requires strengthening health systems, but there is also a role for focused, targeted interventions. Choosing a strategy involves identifying appropriate channels for reaching high coverage, which depends on many factors such as access to and attendance at healthcare facilities. Delivery channels vary, and may include facility- and community-based healthcare providers, mass media campaigns, and community-based approaches and marketing strategies. Issues related to scaling up are discussed in the context of four interventions that may be given to mothers at different stages throughout pregnancy or to newborns: (1) detection and treatment of syphilis; (2) emergency Cesarean section; (3) newborn resuscitation; and (4) kangaroo mother care. Systematic reviews of the literature and large-scale implementation studies are analyzed for each intervention.</p> <p>Conclusion</p> <p>Equitable and successful scale-up of preterm birth and stillbirth interventions will require addressing multiple barriers, and utilizing multiple delivery approaches and channels. Another important need is developing strategies to discontinue ineffective or harmful interventions. Preterm birth and stillbirth interventions must also be placed in the broader maternal, newborn and child health context to identify and prioritize those that will help improve several outcomes at the same time. The next article discusses advocacy challenges and opportunities.</p
    corecore