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101.
Background
The actual burden and causative agent of tuberculous lymphadenitis (TBLN) cases is not well known due to lack of strong surveillance system and diagnostic facilities in Ethiopia. This study was conducted to determine the prevalence of TBLN, its causative agent and risk factors for acquiring this infection.Methods
A cross-sectional study was conducted from April to May 2012 at four main hospitals and one diagnostic clinic located in northern Ethiopia. Fine needle aspirates (FNAs) from TBLN suspects were taken for acid fast bacilli (AFB) microscopy, culture and molecular typing.Results
Among 437 aspirates, culture yielded AFB in 226 (51.7%) of cases. Sixty one culture negative cases (30.5% of 200 cases) were positive by Xpert MTB/RIF test. Moreover, a rifampicin resistant AFB was detected from culture negative cases. The overall prevalence of FNAs positive TBLN cases was 65.8 %. The BacT/AlerT 3D system proved to be a more rapid method with higher recovery rate than Lowenstein-Jensen (L-J) and/or Gottsacker media (P<0.0001). Molecular typing identified all culture positive isolates as M.tuberculosis. The main risk factors for TBLN were pediatric age (OR 2.8, 95% CI, 1.09- 7.05) and cough (OR 2, 95%CI, 1.09-3.7).Conclusions
The results of this study revealed a high prevalence of TBLN in the study sites and that pediatric age and cough are key predictors of the disease. TBLN is an important public health problem that needs to be addressed in the area. It is important to note that MDR strains of TB could be involved and aetiological confirmation and drug sensitivity testing of TBLN isolates should be expanded. Further studies on the M.tuberculosis lineages, circulating strains and transmission dynamics, are recommended. 相似文献102.
Maria Bendz Marcin Skwark Daniel Nilsson Viktor Granholm Susana Cristobal Lukas Käll Arne Elofsson 《Proteomics》2013,13(9):1467-1480
Topology analysis of membrane proteins can be obtained by enzymatic shaving in combination with MS identification of peptides. Ideally, such analysis could provide quite detailed information about the membrane spanning regions. Here, we examine the ability of some shaving enzymes to provide large‐scale analysis of membrane proteome topologies. To compare different shaving enzymes, we first analyzed the detected peptides from two over‐expressed proteins. Second, we analyzed the peptides from non‐over‐expressed Escherichia coli membrane proteins with known structure to evaluate the shaving methods. Finally, the identified peptides were used to test the accuracy of a number of topology predictors. At the end we suggest that the usage of thermolysin, an enzyme working at the natural pH of the cell for membrane shaving, is superior because: (i) we detect a similar number of peptides and proteins using thermolysin and trypsin; (ii) thermolysin shaving can be run at a natural pH and (iii) the incubation time is quite short. (iv) Fewer detected peptides from thermolysin shaving originate from the transmembrane regions. Using thermolysin shaving we can also provide a clear separation between the best and the less accurate topology predictors, indicating that using data from shaving can provide valuable information when developing new topology predictors. 相似文献
103.
Britta Johansen Christian Uhrenfeldt Arne Nylandsted Larsen 《Plasmonics (Norwell, Mass.)》2013,8(1):153-158
This work investigates the localized surface plasmon resonance (LSPR) of β-Sn also known as white tin. Recently, studies on arrays of β-Sn nanoparticles have shown that these arrays possess strong optical features caused by diffractive effects in the particle grating (Johansen et al., Phys Rev B 84:113405–113408, 2011). In the presence of the grating, the LSPR could not clearly be distinguished in the spectra. To get a better understanding of the plasmonic properties of the particles, we have now eliminated the diffractive effects by placing the particles in a random distribution. The particles were fabricated by electron beam lithography on a fused silica substrate and investigated by optical transmission measurements. In the random configuration, a clear LSPR is observed at 530 nm for particles with a diameter of 155 nm and a height of 50 nm. 相似文献
104.
Ancient Evolutionary Trade-Offs between Yeast Ploidy States 总被引:1,自引:0,他引:1
Enik? Z?rg? Karolina Chwialkowska Arne B. Gjuvsland Elena Garré Per Sunnerhagen Gianni Liti Anders Blomberg Stig W. Omholt Jonas Warringer 《PLoS genetics》2013,9(3)
The number of chromosome sets contained within the nucleus of eukaryotic organisms is a fundamental yet evolutionarily poorly characterized genetic variable of life. Here, we mapped the impact of ploidy on the mitotic fitness of baker''s yeast and its never domesticated relative Saccharomyces paradoxus across wide swaths of their natural genotypic and phenotypic space. Surprisingly, environment-specific influences of ploidy on reproduction were found to be the rule rather than the exception. These ploidy–environment interactions were well conserved across the 2 billion generations separating the two species, suggesting that they are the products of strong selection. Previous hypotheses of generalizable advantages of haploidy or diploidy in ecological contexts imposing nutrient restriction, toxin exposure, and elevated mutational loads were rejected in favor of more fine-grained models of the interplay between ecology and ploidy. On a molecular level, cell size and mating type locus composition had equal, but limited, explanatory power, each explaining 12.5%–17% of ploidy–environment interactions. The mechanism of the cell size–based superior reproductive efficiency of haploids during Li+ exposure was traced to the Li+ exporter ENA. Removal of the Ena transporters, forcing dependence on the Nha1 extrusion system, completely altered the effects of ploidy on Li+ tolerance and evoked a strong diploid superiority, demonstrating how genetic variation at a single locus can completely reverse the relative merits of haploidy and diploidy. Taken together, our findings unmasked a dynamic interplay between ploidy and ecology that was of unpredicted evolutionary importance and had multiple molecular roots. 相似文献
105.
Atle van Beelen Granlund Arnar Flatberg Ann E. ?stvik Ignat Drozdov Bj?rn I. Gustafsson Mark Kidd Vidar Beisvag Sverre H. Torp Helge L. Waldum Tom Christian Martinsen Jan Kristian Dam?s Terje Espevik Arne K. Sandvik 《PloS one》2013,8(2)
Background
In inflammatory bowel disease (IBD), genetic susceptibility together with environmental factors disturbs gut homeostasis producing chronic inflammation. The two main IBD subtypes are Ulcerative colitis (UC) and Crohn’s disease (CD). We present the to-date largest microarray gene expression study on IBD encompassing both inflamed and un-inflamed colonic tissue. A meta-analysis including all available, comparable data was used to explore important aspects of IBD inflammation, thereby validating consistent gene expression patterns.Methods
Colon pinch biopsies from IBD patients were analysed using Illumina whole genome gene expression technology. Differential expression (DE) was identified using LIMMA linear model in the R statistical computing environment. Results were enriched for gene ontology (GO) categories. Sets of genes encoding antimicrobial proteins (AMP) and proteins involved in T helper (Th) cell differentiation were used in the interpretation of the results. All available data sets were analysed using the same methods, and results were compared on a global and focused level as t-scores.Results
Gene expression in inflamed mucosa from UC and CD are remarkably similar. The meta-analysis confirmed this. The patterns of AMP and Th cell-related gene expression were also very similar, except for IL23A which was consistently higher expressed in UC than in CD. Un-inflamed tissue from patients demonstrated minimal differences from healthy controls.Conclusions
There is no difference in the Th subgroup involvement between UC and CD. Th1/Th17 related expression, with little Th2 differentiation, dominated both diseases. The different IL23A expression between UC and CD suggests an IBD subtype specific role. AMPs, previously little studied, are strongly overexpressed in IBD. The presented meta-analysis provides a sound background for further research on IBD pathobiology. 相似文献106.
Alexander Jason B. Bunce Michael White Nicole Wilkinson Shaun P. Adam Arne A. S. Berry Tina Stat Michael Thomas Luke Newman Stephen J. Dugal Laurence Richards Zoe T. 《Coral reefs (Online)》2020,39(1):159-171
Coral Reefs - Cumulative anthropogenic pressures have triggered a global decline in the health of marine ecosystems, and coral reefs, in particular, are in crisis. With climate and... 相似文献
107.
Lie Maria E. K. Kickinger Stefanie Skovgaard-Petersen Jonas Ecker Gerhard F. Clausen Rasmus P. Schousboe Arne White H. Steve Wellendorph Petrine 《Neurochemical research》2020,45(7):1551-1565
Neurochemical Research - Focal epileptic seizures can in some patients be managed by inhibiting γ-aminobutyric acid (GABA) uptake via the GABA transporter 1 (GAT1) using tiagabine... 相似文献
108.
109.
Margit S. Müller Linea F. Obel Helle S. Waagepetersen Arne Schousboe Lasse K. Bak 《Neurochemical research》2013,38(6):1260-1265
The polyether antibiotic ionomycin is a common research tool employed to raise cytosolic Ca2+ in almost any cell type. Although initially thought to directly cause physicochemical translocation of extracellular Ca2+ into the cytosol, a number of studies have demonstrated that the mechanism of action is likely to be more complex, involving modulation of intrinsic Ca2+ signaling pathways. In the present study we assessed the effect of ionomycin on primary cultures of murine cerebellar astrocytes. Ionomycin concentrations ranging from 0.1 to 10 μM triggered a biphasic increase in cytosolic Ca2+, consisting of an initial peak and a subsequent sustained plateau. The response was dependent on concentration and exposure time. While the plateau phase was abolished in the absence of extracellular Ca2+, the peak phase persisted. The peak amplitude could be lowered significantly by application of dantrolene, demonstrating involvement of Ca2+-induced Ca2+-release (CICR). The plateau phase was markedly reduced when store-operated Ca2+-entry (SOCE) was blocked with 2-aminoethoxydiphenyl borate. Our results show that ionomycin directly affects internal Ca2+ stores in astrocytes, causing release of Ca2+ into the cytosol, which in turn triggers further depletion of the stores through CICR and subsequently activates SOCE. This mechanistic action of ionomycin is important to keep in mind when employing it as a pharmacological tool. 相似文献
110.
Exposing Pseudomonas aeruginosa biofilm grown on the inner surface of Teflon and silicone tubes to UVC light (265 nm) from light emitting diodes (LED) has previously been shown to substantially reduce biofilm growth. Smaller UVC fluencies were required to disinfect Teflon tubes compared to silicone tubes. Light propagation enhancement in tubes can be obtained if the refractive index of the intra-luminal saline solution is higher than that of the polymer. This condition is achieved by using Teflon tubes with a low refractive index (1.34) instead of the polymers with a high refractive index (1.40–1.50) normally used for tubing in catheter production. Determining whether or not UVC light exposure can disinfect and maintain the intra-luminal number of colony forming units (CFUs) at an exceedingly low level and thus avoid the growth and establishment of biofilm is of interest. The use of UVC diodes is demonstrated to be a preventative disinfection treatment on tubes made of Teflon, which enhances the UVC light propagation, and on tubes made of a softer material, ethylene vinyl acetate (EVA), which is suitable for catheters but much less suitable for UVC light propagation. Simulating an aseptic breach (~103–104 CFU ml?1), the UVC disinfection set-up was demonstrated using tubes contaminated with planktonic P. aeruginosa. After the tubes (10–20 cm) were inoculated with the bacterial solution for 3 h, they were emptied and filled with saline solutions (0.9–20%). Next UVC fluencies (0–21 mJ cm?2) were applied to the tubes 3 h after inoculation. Colony counts were carried out on liquid samples drawn from the tubes the first day after UVC treatment and liquid and surface samples were collected and analyzed 3–4 days later. A fluence of approximately 1.0 mJ cm?2 was noted as being sufficient for no growth for a period of 3–4 days for the Teflon tubes. Determining the fluence threshold for the EVA tubes was not possible. Almost all of the UVC-treated EVA tubes were disinfected simply by filling the tubes with a saline solution. Direct UVC treatment of the contaminated EVA tubes revealed, however, that a fluence of 21 mJ cm?2 killed the bacteria present in the tubes and kept them disinfected for a period of 3–4 days. 相似文献