273 research outputs found
Publishing interim results of randomised clinical trials in peer-reviewed journals
Background:
Interim analyses of randomised controlled trials are sometimes published before the final results are available. In several cases, the treatment effects were noticeably different after patient recruitment and follow-up completed. We therefore conducted a literature review of peer-reviewed journals to compare the reported treatment effects between interim and final publications and to examine the magnitude of the difference.
Methods:
We performed an electronic search of MEDLINE from 1990 to 2014 (keywords: ‘clinical trial’ OR ‘clinical study’ AND ‘random*’ AND ‘interim’ OR ‘preliminary’), and we manually identified the corresponding final publication. Where the electronic search produced a final report in which the abstract cited interim results, we found the interim publication. We also manually searched every randomised controlled trial in eight journals, covering a range of impact factors and general medical and specialist publications (1996–2014). All paired articles were checked to ensure that the same comparison between interventions was available in both.
Results:
In all, 63 studies are included in our review, and the same quantitative comparison was available in 58 of these. The final treatment effects were smaller than the interim ones in 39 (67%) trials and the same size or larger in 19 (33%). There was a marked reduction, defined as a ≥20% decrease in the size of the treatment effect from interim to final analysis, in 11 (19%) trials compared to a marked increase in 3 (5%), p = 0.057. The magnitude of percentage change was larger in trials where commercial support was reported, and increased as the proportion of final events at the interim report decreased in trials where commercial support was reported (interaction p = 0.023). There was no evidence of a difference between trials that stopped recruitment at the interim analysis where this was reported as being pre-specified versus those that were not pre-specified (interaction p = 0.87).
Conclusion:
Published interim trial results were more likely to be associated with larger treatment effects than those based on the final report. Publishing interim results should be discouraged, in order to have reliable estimates of treatment effects for clinical decision-making, regulatory authority reviews and health economic analyses. Our work should be expanded to include conference publications and manual searches of additional journal publications
Corticosteroid treatment is associated with increased filamentous fungal burden in allergic fungal disease
Background
Allergic diseases caused by fungi are common. The best understood conditions are allergic
bronchopulmonaryaspergillosis (ABPA) and severe asthma with fungal sensitisation (SAFS).
Our knowledge of the fungal microbiome (mycobiome) is limited to a few studies involving
healthy individuals, asthmatics and smokers. No study has yet examined the mycobiome in
fungal lung disease.
Objectives
The main aim of this study was to determine the mycobiome in lungs of individuals with well
characterised fungal disease. A secondary objective was to determine possible effects of
treatment on the mycobiome.
Methods
After bronchoscopy, ITS1 DNA was amplified and sequenced and fungal load determined by
RT-PCR. Clinical and treatment variables were correlated with the main species identified.
ABPA (n=16), SAFS (n=16), severe asthma not sensitised to fungi, (n=9), mild asthma
patients(n=7) and 10 healthy controls were studied.
Results
The mycobiome was highly varied with severe asthmatics carrying higher loads of fungus.
Healthy individuals had low fungal loads, mostly poorly characterised Malasezziales.The
most common fungus in asthmatics was Aspergillus fumigatus complex and this taxon
accounted for the increased burden of fungus in the high level samples. Corticosteroid
treatment was significantly associated with increased fungal load (p<0.01).
Conclusions
The mycobiome is highly variable. Highest loads of fungus are observed in severe asthmatics
and the most common fungus is Aspergillus fumigatus complex. Individuals receiving steroid
therapy had significantly higher levels of Aspergillus and total fungus in their BAL
A proteomic approach to investigating gene cluster expression and secondary metabolite functionality in Aspergillus fumigatus.
A combined proteomics and metabolomics approach was utilised to advance the identification and characterisation of secondary metabolites in Aspergillus fumigatus. Here, implementation of a shotgun proteomic strategy led to the identification of non-redundant mycelial proteins (n = 414) from A. fumigatus including proteins typically under-represented in 2-D proteome maps: proteins with multiple transmembrane regions, hydrophobic proteins and proteins with extremes of molecular mass and pI. Indirect identification of secondary metabolite cluster expression was also achieved, with proteins (n = 18) from LaeA-regulated clusters detected, including GliT encoded within the gliotoxin biosynthetic cluster. Biochemical analysis then revealed that gliotoxin significantly attenuates H2O2-induced oxidative stress in A. fumigatus (p>0.0001), confirming observations from proteomics data. A complementary 2-D/LC-MS/MS approach further elucidated significantly increased abundance (p<0.05) of proliferating cell nuclear antigen (PCNA), NADH-quinone oxidoreductase and the gliotoxin oxidoreductase GliT, along with significantly attenuated abundance (p<0.05) of a heat shock protein, an oxidative stress protein and an autolysis-associated chitinase, when gliotoxin and H2O2 were present, compared to H2O2 alone. Moreover, gliotoxin exposure significantly reduced the abundance of selected proteins (p<0.05) involved in de novo purine biosynthesis. Significantly elevated abundance (p<0.05) of a key enzyme, xanthine-guanine phosphoribosyl transferase Xpt1, utilised in purine salvage, was observed in the presence of H2O2 and gliotoxin. This work provides new insights into the A. fumigatus proteome and experimental strategies, plus mechanistic data pertaining to gliotoxin functionality in the organism
Comparative proteomic analysis of spermatozoa isolated by swim-up or density gradient centrifugation
Abstract
BACKGROUND:
Reports about the morphologic and functional characteristics of spermatozoa prepared by density gradient centrifugation (DC) or swim-up (SU) have produced discordant results. We have performed a proteomic comparison of cells prepared by DC and SU providing a molecular insight into the differences between these two methods of sperm cell isolation.
METHODS:
Protein maps were obtained by 2-dimensional (2-D) separations consisting of isoelectrofocusing (IEF) from pI 3 to 11 followed by SDS-polyacrylamide gel electrophoresis. 2-D gels were stained with Sypro Ruby. Map images of DC and SU spermatozoa were compared using dedicated software. Intensities of a given spot were considered different between DC and SU when their group mean differed by >1.5-fold (p<0.05, Anova).
RESULTS:
No differences were observed for 853 spots, indicating a 98.7% similarity between DC and SU. Five spots were DC>SU and 1 was SU>DC. Proteins present in 3 of the differential spots could be identified. One DC>SU spot contained lactate dehydrogenase C and gamma-glutamylhydrolase, a second DC>SU spot contained fumarate hydratase and glyceraldehyde-3-phosphate dehydrogenase-2, and a SU>DC spot contained pyruvate kinase M1/M2.
CONCLUSIONS:
The differences in protein levels found on comparison of DC with SU spermatozoa indicate possible dissimilarities in their glycolytic metabolism and DNA methylation and suggest that DC cells may have a better capacitation potential
Adhesive Antibacterial Moisturizing Nanostructured Skin Patch for Sustainable Development of Atopic Dermatitis Treatment in Humans
Atopic dermatitis (AD) is a chronic inflammatory skin disease with a complex etiology that lacks effective treatment. The therapeutic goals include alleviating symptoms, such as moisturizing and applying antibacterial and anti-inflammatory medications. Hence, there is an urgent need to develop a patch that effectively alleviates most of the AD symptoms. In this study, we employed a "green" cross-linking approach of poly(vinyl alcohol) (PVA) using glycerol, and we combined it with polyacrylonitrile (PAN) to fabricate core-shell (CS) nanofibers through electrospinning. Our designed structure offers multiple benefits as the core ensures controlled drug release and increases the strength of the patch, while the shell provides skin moisturization and exudate absorption. The efficient PVA cross-linking method facilitates the inclusion of sensitive molecules such as fermented oils. In vitro studies demonstrate the patches' exceptional biocompatibility and efficacy in minimizing cell ingrowth into the CS structure containing argan oil, a property highly desirable for easy removal of the patch. Histological examinations conducted on an ex vivo model showed the nonirritant properties of developed patches. Furthermore, the eradication of Staphylococcus aureus bacteria confirms the potential use of CS nanofibers loaded with argan oil or norfloxacin, separately, as an antibacterial patch for infected AD wounds. In vivo patch application studies on patients, including one with AD, demonstrated ideal patches' moisturizing effect. This innovative approach shows significant promise in enhancing life quality for AD sufferers by improving skin hydration and avoiding infections
The prospects for Yb- and Nd-doped tungstate microchip lasers
Potassium gadolinium and yttrium tungstates doped with trivalent Nd, Yb or Tm ions are widely used crystals for efficient diode-pumped lasers. They are usually oriented along the b crystallographic axis, which is also the N p axis of optical indicatrix. The Np-cut is characterized by a strong thermal lens with opposing signs along Nm and N g [1]. This is unsuited to microchip lasers which require a positive thermal lens for a stable cavity. Therefore, a detailed investigation of thermo-optic effects and microchip laser potential of other crystallographic orientations in tungstate crystals is of interest
Laser-related spectroscopic parameters of NV colour centres in diamond
One of the most common impurities in synthetic diamond is single substitutional nitrogen, which is incorporated in the diamond lattice substituting a carbon atom [1]. If the nitrogen is adjacent to a vacancy in the diamond lattice, it forms the nitrogen-vacancy (NV) colour centre (CC) [1]. The negatively charged state of this CC, NV-, is particularly well studied since its quantum properties are suitable for applications such as quantum information processing, single-photon sources and optical magnetometry [2]. NV CCs in the neutral state (NV0) are less widely studied. This CC exhibits broadband luminescence at slightly shorter wavelengths than NV-, and hence is also potentially of interest for tuneable and ultrafast visible laser applications. In this report, we present a detailed study of the laser-related spectroscopic properties of a diamond containing NV0 and NV- CCs
The negative cofactor 2 complex is a key regulator of drug resistance in Aspergillus fumigatus
The frequency of antifungal resistance, particularly to the azole class of ergosterol biosynthetic inhibitors, is a growing global health problem. Survival rates for those infected with resistant isolates are exceptionally low. Beyond modification of the drug target, our understanding of the molecular basis of azole resistance in the fungal pathogen Aspergillus fumigatus is limited. We reasoned that clinically relevant antifungal resistance could derive from transcriptional rewiring, promoting drug resistance without concomitant reductions in pathogenicity. Here we report a genome-wide annotation of transcriptional regulators in A. fumigatus and construction of a library of 484 transcription factor null mutants. We identify 12 regulators that have a demonstrable role in itraconazole susceptibility and show that loss of the negative cofactor 2 complex leads to resistance, not only to the azoles but also the salvage therapeutics amphotericin B and terbinafine without significantly affecting pathogenicity
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