Evaluation of the hyplex® TBC PCR test for detection of Mycobacterium tuberculosis complex in clinical samples

<p>Abstract</p> <p>Background</p> <p>Tuberculosis (TB) is one of the major public health concerns worldwide. The detection of the pathogen <it>Mycobacterium tuberculosis </it>complex (MTBC) as early as possible has a great impact on the effective control of the spread of the disease. In our study, we evaluated the hyplex^®TBC PCR test (BAG Health Care GmbH), a novel assay using a nucleic acid amplification technique (NAAT) with reverse hybridisation and ELISA read out for the rapid detection of <it>M. tuberculosis </it>directly in clinical samples.</p> <p>Results</p> <p>A total of 581 respiratory and non-respiratory specimens from our pneumological hospital and the National TB Institute of Uzbekistan were used for the evaluation of the PCR assay. Of these, 292 were classified as TB samples and 289 as non-TB samples based on the results of the TB cultures as reference method. The PCR results were initially used to optimise the cut-off value of the hyplex^®TBC test system by means of a ROC analysis. The overall sensitivity of the assay was determined to be 83.1%. In smear-positive TB samples, the sensitivity of the hyplex^®TBC PCR test was estimated to 93.4% versus 45.1% in smear-negative samples. The specificity of the test was 99.25%. Of the two specimens (0.75%) with false-positive PCR results, one yielded a culture positive for non-tuberculous mycobacteria. Based on the assumption of a prevalence of 8% TB positives among the samples in our diagnostic TB laboratory, the positive and negative predictive values were estimated to 90.4% and 98.5%, respectively.</p> <p>Conclusions</p> <p>The hyplex^®TBC PCR test is an accurate NAAT assay for a rapid and reliable detection of <it>M. tuberculosis </it>in various respiratory and non-respiratory specimens. Compared to many other conventional NAAT assays, the hyplex^®TBC PCR test is in a low price segment which makes it an attractive option for developing and emerging countries with high TB burdens.</p

FLT3 mutations in Early T-Cell Precursor ALL characterize a stem cell like leukemia and imply the clinical use of tyrosine kinase inhibitors

Early T-cell precursor acute lymphoblastic leukemia (ETP-ALL) has been identified as high-risk subgroup of acute T-lymphoblastic leukemia (T-ALL) with a high rate of FLT3-mutations in adults. To unravel the underlying pathomechanisms and the clinical course we assessed molecular alterations and clinical characteristics in a large cohort of ETP-ALL (n = 68) in comparison to non-ETP T-ALL adult patients. Interestingly, we found a high rate of FLT3-mutations in ETP-ALL samples (n = 24, 35%). Furthermore, FLT3 mutated ETP-ALL was characterized by a specific immunophenotype (CD2+/CD5-/CD13+/CD33-), a distinct gene expression pattern (aberrant expression of IGFBP7, WT1, GATA3) and mutational status (absence of NOTCH1 mutations and a low frequency, 21%, of clonal TCR rearrangements). The observed low GATA3 expression and high WT1 expression in combination with lack of NOTCH1 mutations and a low rate of TCR rearrangements point to a leukemic transformation at the pluripotent prothymocyte stage in FLT3 mutated ETP-ALL. The clinical outcome in ETP-ALL patients was poor, but encouraging in those patients with allogeneic stem cell transplantation (3-year OS: 74%). To further explore the efficacy of targeted therapies, we demonstrate that T-ALL cell lines transfected with FLT3 expression constructs were particularly sensitive to tyrosine kinase inhibitors. In conclusion, FLT3 mutated ETP-ALL defines a molecular distinct stem cell like leukemic subtype. These data warrant clinical studies with the implementation of FLT3 inhibitors in addition to early allogeneic stem cell transplantation for this high risk subgroup

A pre-clinical validation plan to evaluate analytical sensitivities of molecular diagnostics such as BD MAX MDR-TB, Xpert MTB/Rif Ultra and FluoroType MTB

Rapid diagnosis of tuberculosis (TB) and antibiotic resistances are imperative to initiate effective treatment and to stop transmission of the disease. A new generation of more sensitive, automated molecular TB diagnostic tests has been recently launched giving microbiologists more choice between several assays with the potential to detect resistance markers for rifampicin and isoniazid. In this study, we determined analytical sensitivities as 95% limits of detection (LoD(95)) for Xpert MTB/Rif Ultra (XP-Ultra) and BD-MAX MDR-TB (BD-MAX) as two representatives of the new test generation, in comparison to the conventional FluoroType MTB (FT-MTB). Test matrices used were physiological saline solution, human and a mucin-based artificial sputum (MUCAS) each spiked with Mycobacterium tuberculosis in declining culture- and qPCR-controlled concentrations. With BD-MAX, XP-Ultra, and FTMTB, we measured LoD(95)(TB) values of 2.1 cfu/ml (CI95%: 0.9-23.3), 3.1 cfu/ml (CI95%: 1.288.9), and 52.1 cfu/ml (CI95%: 16.7-664.4) in human sputum;of 6.3 cfu/ml (CI95%: 2.931.8), 1.5 cfu/ml (CI95%: 0.7-5.0), and 30.4 cfu/ml (CI95%: 17.4-60.7) in MUCAS;and of 2.3 cfu/ml (CI95%: 1.1-12.0), 11.5 cfu/ml (CI95%: 5.6-47.3), and 129.1 cfu/ml (CI95%: 82.8-273.8) in saline solution, respectively. LoD(95) of resistance markers were 9 to 48 times higher compared to LoD(95)(TB). BD-MAX and XP-Ultra have an equal and significantly increased analytical sensitivity compared to conventional tests. MUCAS resembled human sputum, while both yielded significantly different results than normal saline. MUCAS proved to be suitable for quality control of PCR assays for TB diagnostics

Digital Collages and Aesthetic-Communicative Networking: Insights into a Workshop of the NFKB Research Cluster Interaction and Participation

Dieser Beitrag dokumentiert Eindrücke, Beobachtungen und Ergebnisse aus einem Online-Workshop des Forschungsclusters «Interaktion und Partizipation in der Kulturellen Bildung», der die Vorstellung von Themen, Arbeitsweisen und Prinzipien des Forschungsclusters zum Ziel hatte. Dabei lag es nahe, die Auseinandersetzung selbst interaktiv und partizipativ sowie entlang der Thematik der rahmenden Tagung zu konzipieren. Ein Grossteil der Kommunikation wird hierfür parallel zur Videokonferenz auf ein digitales Whiteboard verlagert, auf dem alle Teilnehmenden individuell und gemeinsam agieren können. Als Material liegen zentrale Fragmente aus einem Text des Clusters bereit, in dem die Begriffe Interaktion und Partizipation in einem gemeinsamen Selbstversuch und geleitet vom Prinzip der Collage verhandelt werden. Dieses Textprinzip wird zum Handlungsprinzip des Workshops: Die Teilnehmenden werden dem Versuch ausgesetzt, in kleinen Gruppen auf dem digitalen Whiteboard sowohl mit dem bereitgestellten als auch mit eigenem Material selbst Collagen zu erstellen. In dem experimentellen Format des Workshops konturiert sich performativ ein ästhetisch-digitaler Möglichkeits- und Erfahrungsraum, in dem die individuellen Positionen und Perspektiven aller Beteiligten über Text, Bild und Sprache interaktiv in vernetzende Artikulationsformen treten. In den entstandenen Collagen kommen Aspekte von Ästhetik, Digitalität und Macht in eindrücklicher Weise zum Tragen.This contribution documents – especially visually – impressions, observations and results from an online workshop «Interaction and Participation in Cultural Education», which aimed to present topics, working methods and principles of the research cluster. It made sense to conceptualize the workshop itself in an interactive and participative manner, as well as along the theme of the framing conference. A large part of the communication is shifted to a digital whiteboard parallel to the video conference, on which all participants can act individually and together. Central fragments from a text of the cluster are available as material, in which the terms interaction and participation are negotiated in a joint self-experiment and guided by the principle of collage. The text principle becomes the operating principle of the workshop: The participants are exposed to the attempt to create collages themselves in small groups on the digital whiteboard using both the provided and their own material. In the experimental format of the workshop, an aesthetic-digital space of possibility and experience is contoured performatively, in which the individual positions and perspectives of all participants interactively enter into networked forms of articulation via text, image and language. In the resulting collages, aspects of aesthetics, digitality and power come into play in an impressive way

GRAVITY: getting to the event horizon of Sgr A*

We present the second-generation VLTI instrument GRAVITY, which currently is in the preliminary design phase. GRAVITY is specifically designed to observe highly relativistic motions of matter close to the event horizon of Sgr A*, the massive black hole at center of the Milky Way. We have identified the key design features needed to achieve this goal and present the resulting instrument concept. It includes an integrated optics, 4-telescope, dual feed beam combiner operated in a cryogenic vessel; near infrared wavefront sensing adaptive optics; fringe tracking on secondary sources within the field of view of the VLTI and a novel metrology concept. Simulations show that the planned design matches the scientific needs; in particular that 10 microarcsecond astrometry is feasible for a source with a magnitude of K=15 like Sgr A*, given the availability of suitable phase reference sources.Comment: 13 pages, 11 figures, to appear in the conference proceedings of SPIE Astronomical Instrumentation, 23-28 June 2008, Marseille, Franc

Rapid Behavioral and Genomic Responses to Social Opportunity

From primates to bees, social status regulates reproduction. In the cichlid fish Astatotilapia (Haplochromis) burtoni, subordinate males have reduced fertility and must become dominant to reproduce. This increase in sexual capacity is orchestrated by neurons in the preoptic area, which enlarge in response to dominance and increase expression of gonadotropin-releasing hormone 1 (GnRH1), a peptide critical for reproduction. Using a novel behavioral paradigm, we show for the first time that subordinate males can become dominant within minutes of an opportunity to do so, displaying dramatic changes in body coloration and behavior. We also found that social opportunity induced expression of the immediate-early gene egr-1 in the anterior preoptic area, peaking in regions with high densities of GnRH1 neurons, and not in brain regions that express the related peptides GnRH2 and GnRH3. This genomic response did not occur in stable subordinate or stable dominant males even though stable dominants, like ascending males, displayed dominance behaviors. Moreover, egr-1 in the optic tectum and the cerebellum was similarly induced in all experimental groups, showing that egr-1 induction in the anterior preoptic area of ascending males was specific to this brain region. Because egr-1 codes for a transcription factor important in neural plasticity, induction of egr-1 in the anterior preoptic area by social opportunity could be an early trigger in the molecular cascade that culminates in enhanced fertility and other long-term physiological changes associated with dominance

A systematic review of the evidence for single stage and two stage revision of infected knee replacement

BACKGROUND: Periprosthetic infection about the knee is a devastating complication that may affect between 1% and 5% of knee replacement. With over 79 000 knee replacements being implanted each year in the UK, periprosthetic infection (PJI) is set to become an important burden of disease and cost to the healthcare economy. One of the important controversies in treatment of PJI is whether a single stage revision operation is superior to a two-stage procedure. This study sought to systematically evaluate the published evidence to determine which technique had lowest reinfection rates. METHODS: A systematic review of the literature was undertaken using the MEDLINE and EMBASE databases with the aim to identify existing studies that present the outcomes of each surgical technique. Reinfection rate was the primary outcome measure. Studies of specific subsets of patients such as resistant organisms were excluded. RESULTS: 63 studies were identified that met the inclusion criteria. The majority of which (58) were reports of two-stage revision. Reinfection rated varied between 0% and 41% in two-stage studies, and 0% and 11% in single stage studies. No clinical trials were identified and the majority of studies were observational studies. CONCLUSIONS: Evidence for both one-stage and two-stage revision is largely of low quality. The evidence basis for two-stage revision is significantly larger, and further work into direct comparison between the two techniques should be undertaken as a priority