630 research outputs found
Nucleosomes indicate the in vitro radiosensitivity of irradiated bronchoepithelial and lung cancer cells
Nucleosomes, which are typical cell death products, are elevated in the serum of cancer patients and are known to rapidly increase during radiotherapy. As both normal and malignant cells are damaged by irradiation, we investigated to which extent both cell types contribute to the release of nucleosomes. We cultured monolayers of normal bronchoepithelial lung cells (BEAS-2B, n = 18) and epithelial lung cancer cells (EPLC, n = 18), exposed them to various radiation doses (0, 10 and 30 Gy) and observed them for 5 days. Culture medium was changed every 24 h. Subsequently, nucleosomes were determined in the supernatant by the Cell Death Detection-ELISA(plus) ( Roche Diagnostics). Additionally, the cell number was estimated after harvesting the cells in a second preparation. After 5 days, the cell number of BEAS-2B cultures in the irradiated groups (10 Gy: median 0.03 x 10(6) cells/culture, range 0.02-0.08 x 10(6) cells/culture; 30 Gy: median 0.08 x 10(6) cells/culture, range 0.02-0.14 x 10(6) cells/culture) decreased significantly (10 Gy: p = 0.005; 30 Gy p = 0.005; Wilcoxon test) compared to the non-irradiated control group (median 4.81 x 10(6) cells/culture, range 1.50-9.54 x 10(6) cells/culture). Consistently, nucleosomes remained low in the supernatant of nonirradiated BEAS-2B. However, at 10 Gy, BEAS-2B showed a considerably increasing release of nucleosomes, with a maximum at 72 h ( before irradiation: 0.24 x 10(3) arbitrary units, AU, range 0.13-4.09 x 10(3) AU, and after 72 h: 1.94 x 10(3) AU, range 0.11-5.70 x 10(3) AU). At 30 Gy, the release was even stronger, reaching the maximum earlier (at 48 h, 11.09 x 10(3) AU, range 6.89-18.28 x 10(3) AU). In non-irradiated EPLC, nucleosomes constantly increased slightly. At 10 Gy, we observed a considerably higher release of nucleosomes in EPLC, with a maximum at 72 h (before irradiation: 2.79 x 10(3) AU, range 2.42-3.80 x 10(3) AU, and after 72 h: 7.16 x 10(3) AU, range 4.30-16.20 x 10(3) AU), which was more than 3.5 times higher than in BEAS-2B. At 30 Gy, the maximum (6.22 x 10(3) AU, range 5.13-9.71 x 10(3) AU) was observed already after 24 h. These results indicate that normal bronchoepithelial and malignant lung cancer cells contribute to the release of nucleosomes during irradiation in a dose-and time-dependent manner with cancer cells having a stronger impact at low doses. Copyright (C) 2004 S. Karger AG, Basel
Identification of Streptococcus pneumoniae by a real-time PCR assay targeting SP2020.
Real-time PCR targeting lytA (the major autolysin gene) and piaB (permease gene of the pia ABC transporter) are currently used as the gold-standard culture-independent assays for Streptococcus pneumoniae identification. We evaluated the performance of a new real-time PCR assay - targeting SP2020 (putative transcriptional regulator gene) - and compared its performance with the assays previously described. A collection of 150 pneumococci, 433 non-pneumococci and 240 polymicrobial samples (obtained from nasopharynx, oropharynx, and saliva; 80 from each site) was tested. SP2020 and lytA-CDC assays had the best performance (sensitivity of 100% for each compared to 95.3% for piaB). The specificity for lytA and piaB was 99.5% and for SP2020 was 99.8%. Misidentifications occurred for the three genes: lytA, piaB and SP2020 were found in non-pneumococcal strains; piaB was absent in some pneumococci including a serotype 6B strain. Combining lytA and SP2020 assays resulted in no misidentifications. Most polymicrobial samples (88.8%) yielded concordant results for the three molecular targets. The remaining samples seemed to contain non-typeable pneumococci (0.8%), and non-pneumococci positive for lytA (1.7%) or SP2020 (8.7%). We propose that combined detection of both lytA-CDC and SP2020 is a powerful strategy for the identification of pneumococcus either in pure cultures or in polymicrobial samples
Pneumococcal Serotypes Colonise the Nasopharynx in Children at Different Densities.
Prevalence of pneumococcal serotypes in carriage and disease has been described but absolute serotype colonisation densities have not been reported. 515 paediatric nasal swab DNA extracts were subjected to lytA qPCR and molecular serotyping by microarray. Absolute serotype densities were derived from total pneumococcal density (qPCR cycle threshold and standard curve) and relative abundance (microarray) and varied widely. Compared to all serotype densities observed, the strongest evidence of differences was seen for serotypes 21 and 35B (higher) and 3, 38 and non-typeables (lower) (p<0.05) with a similar hierarchy when only a single serotype carriage was assessed. There was no evidence of any overall density differences between children with single or multiple serotypes detected but serotypes with mid-range densities were more prevalent. The hierarchy of distinct pneumococcal serotype carriage densities described here for the first time, may help explain the dynamics of transmission between children
Адаптация гидравлической модели водостока к бассейнам рек Дунай и Днестр
Гидравлическая модель водостока адаптирована к бассейну рек Дунай и Днестр. По данным орографии, атмосферных осадках или поверхностном стоке она позволяет рассчитывать объемы, расходы и уровни воды с пространственным разрешением 1 км. В модели возможно использование данные об экосистемах на земной поверхности, типах почвы. По данным наблюдений стока оценены среднемесячные величины расходов рек, которые соответствуют наблюдениям, что позволяет применять модель в дальнейших оценках стока, наносов и т.д.Hydraulic model of water inflow is adapted to the Danube and the Dniester rivers basin. According to the orography, precipitation and surface inflow data it permits to calculate water volumes, discharges and levels with spatial resolution 1 km. It is possible to use the data on ecosystems on the ground surface, types of soil in the model. According to the observations data of the inflow the average monthly values of river discharges corresponding to the observations are estimated. It permits to apply the model in the further estimations of inflow, alluvia e t.c
Birth room transition support for term and near-term infants : A cochrane overview
This is a protocol for a Cochrane Review (Overview). The objectives are as follows: We will describe and summarise Cochrane Reviews of birth room interventions for term or near-term newborn infants, and assess their methodological quality and the validity of their findings. We will map the evidence from Cochrane Reviews and identify important gaps in the evidence base. We will not compare multiple interventions with the intention of drawing inferences about their comparative effectiveness
Birth room transition support for preterm infants : A cochrane overview
This is a protocol for a Cochrane Review (Overview). The objectives are as follows: We will describe and summarise Cochrane Reviews of birth room interventions for preterm infants, and assess their methodological quality and the validity of their findings.We will map the evidence from Cochrane Reviews and identify important gaps in the evidence base. We will not compare multiple interventions with the intention of drawing inferences about their comparative effectiveness
An Examination of Not-For-Profit Stakeholder Networks for Relationship Management: A Small-Scale Analysis on Social Media
Using a small-scale descriptive network analysis approach, this study highlights the importance of stakeholder networks for identifying valuable stakeholders and the management of existing stakeholders in the context of mental health not-for-profit services. We extract network data from the social media brand pages of three health service organizations from the U.S., U.K., and Australia, to visually map networks of 579 social media brand pages (represented by nodes), connected by 5,600 edges. This network data is analyzed using a collection of popular graph analysis techniques to assess the differences in the way each of the service organizations manage stakeholder networks. We also compare node meta-information against basic topology measures to emphasize the importance of effectively managing relationships with stakeholders who have large external audiences. Implications and future research directions are also discussed
Using death to one's advantage: HIV modulation of apoptosis
Infection by human immunodeficiency virus (HIV) is associated with an early immune dysfunction and progressive destruction of CD4+ T lymphocytes. This progressive disappearance of T cells leads to a lack of immune control of HIV replication and to the development of immune deficiency resulting in the increased occurrence of opportunistic infections associated with acquired immune deficiency syndrome (AIDS). The HIV-induced, premature destruction of lymphocytes is associated with the continuous production of HIV viral proteins that modulate apoptotic pathways. The viral proteins, such as Tat, Env, and Nef, are associated with chronic immune activation and the continuous induction of apoptotic factors. Viral protein expression predisposes lymphocytes, particularly CD4+ T cells, CD8+ T cells, and antigen-presenting cells, to evolve into effectors of apoptosis and as a result, to lead to the destruction of healthy, non-infected T cells. Tat and Nef, along with Vpu, can also protect HIV-infected cells from apoptosis by increasing anti-apoptotic proteins and down- regulating cell surface receptors recognized by immune system cells. This review will discuss the validity of the apoptosis hypothesis in HIV disease and the potential mechanism(s) that HIV proteins perform in the progressive T cell depletion observed in AIDS pathogenesis. Originally published Leukemia, Vol. 15, No. 3, Mar 200
Chlorella-enriched hydrogels protect against myocardial damage and reactive oxygen species production in anin vitroischemia/reperfusion model using cardiac spheroids.
Microalgae have emerged as promising photosynthetic microorganisms for biofabricating advanced tissue constructs, with improved oxygenation and reduced reactive oxygen species (ROS) production. However, their use in the engineering of human tissues has been limited due to their intrinsic growth requirements, which are not compatible with human cells. In this study, we first formulated alginate-gelatin (AlgGel) hydrogels with increasing densities ofChlorella vulgaris. Then, we characterised their mechanical properties and pore size. Finally, we evaluated their effects on cardiac spheroid (CS) pathophysiological response under control and ischemia/reperfusion (I/R) conditions. Our results showed that the addition ofChlorelladid not affect AlgGel mechanical properties, while the mean pore size significantly decreased by 35% in the presence of the 107cells ml-1microalgae density. Under normoxic conditions, the addition of 107Chlorellacells ml-1significantly reduced CS viability starting from 14 d in. No changes in pore size nor CS viability were measured for hydrogels containing 105and 106Chlorellacells ml-1. In our I/R model, allChlorella-enriched hydrogels reduced cardiac cell sensitivity to hypoxic conditions with a corresponding reduction in ROS production, as well as protected against I/R-induced reduction in cell viability. Altogether, our results support a promising use ofChlorella-enriched Alg-Gel hydrogels for cardiovascular tissue engineering
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