1,028 research outputs found
Genotypic Diversity Is Associated with Clinical Outcome and Phenotype in Cryptococcal Meningitis across Southern Africa.
Cryptococcal meningitis is a major cause of mortality throughout the developing world, yet little is known about the genetic markers underlying Cryptococcal virulence and patient outcome. We studied a cohort of 230 Cryptococcus neoformans (Cn) isolates from HIV-positive South African clinical trial patients with detailed clinical follow-up using multi-locus sequence typing and in vitro phenotypic virulence assays, correlating these data with clinical and fungal markers of disease in the patient. South African Cn displayed high levels of genetic diversity and locus variability compared to globally distributed types, and we identified 50 sequence types grouped within the main molecular types VNI, VNII and VNB, with 72% of isolates typed into one of seven 'high frequency' sequence types. Spatial analysis of patients' cryptococcal genotype was not shown to be clustered geographically, which might argue against recent local acquisition and in favour of reactivation of latent infection. Through comparison of MLST genotyping data with clinical parameters, we found a relationship between genetic lineage and clinical outcome, with patients infected with the VNB lineage having significantly worse survival (n=8, HR 3.35, CI 1.51-7.20, p=0.003), and this was maintained even after adjustment for known prognostic indicators and treatment regimen. Comparison of fungal genotype with in vitro phenotype (phagocytosis, laccase activity and CSF survival) performed on a subset of 89 isolates revealed evidence of lineage-associated virulence phenotype, with the VNII lineage displaying increased laccase activity (p=0.001) and ex vivo CSF survival (p=0.0001). These findings show that Cryptococcus neoformans is a phenotypically heterogeneous pathogen, and that lineage plays an important role in cryptococcal virulence during human infection. Furthermore, a detailed understanding of the genetic diversity in Southern Africa will support further investigation into how genetic diversity is structured across African environments, allowing assessment of the risks different ecotypes pose to infection
‘Trial and error…’, ‘…happy patients’ and ‘…an old toy in the cupboard’: a qualitative investigation of factors that influence practitioners in their prescription of foot orthoses
Background: Foot orthoses are used to manage of a plethora of lower limb conditions. However, whilst the theoretical
foundations might be relatively consistent, actual practices and therefore the experience of patients is likely to be less so.
The factors that affect the prescription decisions that practitioners make about individual patients is unknown and hence
the way in which clinical experience interacts with knowledge from training is not understood. Further, other influences
on orthotic practice may include the adoption (or not) of technology. Hence the aim of this study was to explore, for
the first time, the influences on orthotic practice.
Methods: A qualitative approach was adopted utilising two focus groups (16 consenting participants in total; 15
podiatrists and 1 orthotist) in order to collect the data. An opening question “What factors influence your orthotic
practice?” was followed with trigger questions, which were used to maintain focus. The dialogue was recorded
digitally, transcribed verbatim and a thematic framework was used to analyse the data.
Results: There were five themes: (i) influences on current practice, (ii) components of current practice, (iii) barriers
to technology being used in clinical practice, (iv) how technology could enhance foot orthoses prescription and
measurement of outcomes, and (v) how technology could provide information for practitioners and patients. A final
global theme was agreed by the researchers and the participants: ‘Current orthotic practice is variable and does not
embrace technology as it is perceived as being not fit for purpose in the clinical environment. However, practitioners
do have a desire for technology that is usable and enhances patient focussed assessment, the interventions, the clinical
outcomes and the patient’s engagement throughout these processes’.
Conclusions: In relation to prescribing foot orthoses, practice varies considerably due to multiple influences.
Measurement of outcomes from orthotic practice is a priority but there are no current norms for achieving this.
There have been attempts by practitioners to integrate technology into their practice, but with largely negative
experiences. The process of technology development needs to improve and have a more practice, rather than
technology focus
The increasing importance of atmospheric demand for ecosystem water and carbon fluxes
Soil moisture supply and atmospheric demand for water independently limit—and profoundly affect—vegetation productivity and water use during periods of hydrologic stress1, 2, 3, 4. Disentangling the impact of these two drivers on ecosystem carbon and water cycling is difficult because they are often correlated, and experimental tools for manipulating atmospheric demand in the field are lacking. Consequently, the role of atmospheric demand is often not adequately factored into experiments or represented in models5, 6, 7. Here we show that atmospheric demand limits surface conductance and evapotranspiration to a greater extent than soil moisture in many biomes, including mesic forests that are of particular importance to the terrestrial carbon sink8, 9. Further, using projections from ten general circulation models, we show that climate change will increase the importance of atmospheric constraints to carbon and water fluxes in all ecosystems. Consequently, atmospheric demand will become increasingly important for vegetation function, accounting for >70% of growing season limitation to surface conductance in mesic temperate forests. Our results suggest that failure to consider the limiting role of atmospheric demand in experimental designs, simulation models and land management strategies will lead to incorrect projections of ecosystem responses to future climate conditions
Optimization of insect cell based protein production processes - online monitoring, expression systems, scale-up
Due to the increasing use of insect cell based expression systems in research and industrial recombinant protein production, the development of efficient and reproducible production processes remains a challenging task. In this context, the application of online monitoring techniques is intended to ensure high and reproducible product qualities already during the early phases of process development. In the following chapter, the most common transient and stable insect cell based expression systems are briefly introduced. Novel applications of insect cell based expression systems for the production of insect derived antimicrobial peptides/proteins (AMPs) are discussed using the example of G. mellonella derived gloverin. Suitable in situ sensor techniques for insect cell culture monitoring in disposable and common bioreactor systems are outlined with respect to optical and capacitive sensor concepts. Since scale-up of production processes is one of the most critical steps in process development, a conclusive overview is given about scale up aspects for industrial insect cell culture processes
Long-term coastal dynamics: The evolution of a mixed sediment mega-nourishment consisting of colliery spoil
A cortical motor nucleus drives the basal ganglia-recipient thalamus in singing birds
The pallido-recipient thalamus transmits information from the basal ganglia to the cortex and is critical for motor initiation and learning. Thalamic activity is strongly inhibited by pallidal inputs from the basal ganglia, but the role of nonpallidal inputs, such as excitatory inputs from cortex, remains unclear. We simultaneously recorded from presynaptic pallidal axon terminals and postsynaptic thalamocortical neurons in a basal ganglia–recipient thalamic nucleus that is necessary for vocal variability and learning in zebra finches. We found that song-locked rate modulations in the thalamus could not be explained by pallidal inputs alone and persisted following pallidal lesion. Instead, thalamic activity was likely driven by inputs from a motor cortical nucleus that is also necessary for singing. These findings suggest a role for cortical inputs to the pallido-recipient thalamus in driving premotor signals that are important for exploratory behavior and learning.National Institutes of Health (U.S.) (Grant R01DC009183)National Institutes of Health (U.S.) (Grant K99NS067062)Damon Runyon Cancer Research Foundation (Postdoctoral Fellowship)Charles A. King Trust (Postdoctoral Fellowship
Genome-wide association and HLA fine-mapping studies identify risk loci and genetic pathways underlying allergic rhinitis
Allergic rhinitis is the most common clinical presentation of allergy, affecting 400 million people worldwide, with increasing incidence in westernized countries1,2. To elucidate the genetic architecture and understand the underlying disease mechanisms, we carried out a meta-analysis of allergic rhinitis in 59,762 cases and 152,358 controls of European ancestry and identified a total of 41 risk loci for allergic rhinitis, including 20 loci not previously associated with allergic rhinitis, which were confirmed in a replication phase of 60,720 cases and 618,527 controls. Functional annotation implicated genes involved in various immune pathways, and fine mapping of the HLA region suggested amino acid variants important for antigen binding. We further performed genome-wide association study (GWAS) analyses of allergic sensitization against inhalant allergens and nonallergic rhinitis, which suggested shared genetic mechanisms across rhinitis-related traits. Future studies of the identified loci and genes might identify novel targets for treatment and prevention of allergic rhinitis
Optimising Nature-Based Treatment Systems for Management of Mine Water
\ua9 2025 by the authors.Deployment of nature-based systems for mine water treatment is constrained by system size, and the evidence suggests decreasing hydraulic conductivity (Ksat) of organic substrates over time compromises performance. In lab-scale continuous-flow reactors, we investigated (1) the geochemical and hydraulic performance of organic substrates used in nature-based systems for metals removal (via bacterial sulfate reduction) from mine water, and then (2) the potential to operate systems modestly contaminated with Zn (0.5 mg/L) at reduced hydraulic residence times (HRTs). Bioreactors containing limestone, straw, and wood chips, with and without compost and/or sewage sludge all achieved 88%–90% Zn removal, but those without compost/sludge had higher Ksat (929–1546 m/d). Using a high Ksat substrate, decreasing the HRT from 15 to 9 h had no impact on Zn removal (92.5% to 97.5%). Although the sulfate reduction rate decreased at a shorter HRT, microbial analysis showed high relative abundance (2%–7%) of sulfate reducing bacteria, and geochemical modelling pointed to ZnS(s) precipitation as the main attenuation mechanism (mean ZnS saturation index = 3.91–4.23). High permeability organic substrate treatment systems operated at a short HRT may offer potential for wider deployment of such systems, but pilot-scale testing under ambient environmental conditions is advisable
Frequency of resistance to methicillin and other antimicrobial agents among Staphylococcus aureus strains isolated from pigs and their human handlers in Trinidad
Background: Methicillin-resistant Staphylococcus aureus (MRSA) has emerged recently worldwide in production animals, particularly pigs and veal calves, which act as reservoirs for MRSA strains for human infection. The study determined the prevalence of MRSA and other resistant strains of S. aureus isolated from the anterior nares of pigs and human handlers on pig farms in Trinidad. Methods: Isolation of S. aureus was done by concurrently inoculating Baird-Parker agar (BPA) and Chromagar MRSA (CHROM) with swab samples and isolates were identified using standard methods. Suspect MRSA isolates from Chromagar and BPA were subjected to confirmatory test using Oxoid PBP2 latex agglutination test. The disc diffusion method was used to determine resistance to antimicrobial agents. Results: The frequency of isolation of MRSA was 2.1% (15 of 723) for pigs but 0.0% (0 of 72) for humans. Generally, for isolates of S. aureus from humans there was a high frequency of resistance compared with those from pigs, which had moderate resistance to the following antimicrobials: penicillin G (54.5%, 51.5%), ampicillin (59.1%, 49.5%), and streptomycin (59.1%, 37.1%), respectively. There was moderate resistance to tetracycline (36.4%, 41.2%) and gentamycin (27.2%, 23.7%) for human and pig S. aureus isolates, respectively, and low resistance to sulfamethoxazole-trimethoprim (4.5%, 6.2%) and norfloxacin (9.1%, 12.4%), respectively. The frequency of resistance to oxacillin by the disc method was 36.4 and 34.0% from S. aureus isolates from humans and pigs, respectively. Out of a total of 78 isolates of S. aureus from both human and pig sources that were resistant to oxacillin by the disc diffusion method, only 15 (19.2%) were confirmed as MRSA by the PBP'2 latex test kit. Conclusions: The detection of MRSA strains in pigs, albeit at a low frequency, coupled with a high frequency of resistance to commonly used antimicrobial agents in pig and humans could have zoonotic and therapeutic implications. Finally, the diagnostic limitation of using CHROMagar and testing for oxacillin resistance by the disc diffusion method alone to determine MRSA strains without performing confirmatory tests cannot be overemphasized because the possibility of overdiagnosis of MRSA infections cannot be ignored
Impacts of climate change on plant diseases – opinions and trends
There has been a remarkable scientific output on the topic of how climate change is likely to affect plant diseases in the coming decades. This review addresses the need for review of this burgeoning literature by summarizing opinions of previous reviews and trends in recent studies on the impacts of climate change on plant health. Sudden Oak Death is used as an introductory case study: Californian forests could become even more susceptible to this emerging plant disease, if spring precipitations will be accompanied by warmer temperatures, although climate shifts may also affect the current synchronicity between host cambium activity and pathogen colonization rate. A summary of observed and predicted climate changes, as well as of direct effects of climate change on pathosystems, is provided. Prediction and management of climate change effects on plant health are complicated by indirect effects and the interactions with global change drivers. Uncertainty in models of plant disease development under climate change calls for a diversity of management strategies, from more participatory approaches to interdisciplinary science. Involvement of stakeholders and scientists from outside plant pathology shows the importance of trade-offs, for example in the land-sharing vs. sparing debate. Further research is needed on climate change and plant health in mountain, boreal, Mediterranean and tropical regions, with multiple climate change factors and scenarios (including our responses to it, e.g. the assisted migration of plants), in relation to endophytes, viruses and mycorrhiza, using long-term and large-scale datasets and considering various plant disease control methods
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