213 research outputs found
Fungal Origins of the Bicyclo[2.2.2]diazaoctane Ring System of Prenylated Indole Alkaloids
Over eight different families of natural products, consisting of nearly seventy secondary metabolites, which contain the bicyclo[2.2.2]diazaoctane ring system, have been isolated from various Aspergillus, Penicillium, and Malbranchea species. Since 1968, these secondary metabolites have been the focus of numerous biogenetic, synthetic, taxonomic, and biological studies, and, as such, have made a lasting impact across multiple scientific disciplines. This review covers the isolation, biosynthesis, and biological activity of these unique secondary metabolites containing the bridging bicyclo[2.2.2]diazaoctane ring system. Furthermore, the diverse fungal origin of these natural products is closely examined and, in many cases, updated to reflect the currently accepted fungal taxonomy
Mortality related to General Anaesthesia and Sedation in Dogs under UK Primary Veterinary Care
The Interplay between Pain and Disease Activity: Personal models of Pain Beliefs and Emotional Representations in Children and young People with Juvenile Idiopathic Arthritis in a UK nationwide prospective inception cohort
Objectives: Juvenile idiopathic arthritis (JIA) is a group of childhood-onset inflammatory rheumatic conditions characterized by pain as one of the most common and distressing symptoms. This cross-sectional study aimed to investigate whether relationships between reported pain anddisease activity in JIA affected beliefs about pain, known as “personal models.”Methods: 187 out of a possible 363 participants with JIA who completed questionnaires about function and pain perception were recruited through the Childhood Arthritis Prospective Study (CAPS). A pre-selected pain score threshold and validated disease activity score cut-offs wereused to assign the participants into four groups: low pain/low disease, low pain/high disease, high pain/low disease, and high pain/high disease.Multivariable linear regressions examined associations between the groups and their “personal models.”Results: Compared to participants with low pain/low disease, those with high pain/high disease and those with high pain/low disease were more likely to sense greater threat, have more negative emotional representations, and perceive less control over their pain. Participants withlow pain/high disease had similar pain beliefs compared to those with low pain/low disease.Conclusion: This is the first study to compare “personal models” of pain in JIA. Children and young people who experience high pain severity regardless of disease activity perceived high pain threat, low controllability, and negative emotional representations. This highlights the importance of considering and addressing personal models of pain at diagnosis, especially those who present high levels of pain.Keywords: chronic pain, children, adolescents, young people, pediatric, juvenile idiopathic arthritis, illness perceptions
Long‐Term Outcomes Following Achievement of Clinically Inactive Disease in Juvenile Idiopathic Arthritis
OBJECTIVE: Potential targets for treat‐to‐target strategies in juvenile idiopathic arthritis are minimal disease activity (MDA) and clinically inactive disease (CID). We undertook this study to compare short‐ and long‐term outcomes following achievement of MDA and CID on the 10‐joint clinical Juvenile Arthritis Disease Activity Score (cJADAS10) and following achievement of CID on Wallace et al's preliminary criteria. METHODS: Children recruited to the Childhood Arthritis Prospective Study, a UK multicenter inception cohort, were selected if they were recruited prior to January 2011 and diagnosed as having oligoarthritis or rheumatoid factor–negative or –positive polyarthritis. One year following diagnosis, children were assessed for MDA on the cJADAS10 and for CID on both Wallace et al's preliminary criteria and the cJADAS10. Associations were tested between those disease states and functional ability, absence of joints with limited range of motion, psychosocial health, and pain at 1 year and annually to 5 years. RESULTS: Of 832 children, 70% were female and the majority had oligoarthritis (68%). At 1 year, 21% had achieved CID according to both definitions, 7% according to Wallace et al's preliminary criteria alone, and 16% according to the cJADAS10 alone; 56% had not achieved CID. Only 10% of children in the entire cohort achieved MDA without also achieving CID. Achieving either early CID state was associated with a greater absence of joints with limited range of motion. However, only CID according to the cJADAS10 was associated with improved functional ability and psychosocial health. Achieving CID was superior to achieving MDA in terms of short‐ and long‐term pain and the absence of joints with limited range of motion
Patient-reported wellbeing and clinical disease measures over time captured by multivariate trajectories of disease activity in individuals with juvenile idiopathic arthritis in the UK: a multicentre prospective longitudinal study
Background: Juvenile idiopathic arthritis (JIA) is a heterogeneous disease, the signs and symptoms of which can be
summarised with use of composite disease activity measures, including the clinical Juvenile Arthritis Disease Activity
Score (cJADAS). However, clusters of children and young people might experience different global patterns in their
signs and symptoms of disease, which might run in parallel or diverge over time. We aimed to identify such clusters in
the 3 years after a diagnosis of JIA. The identification of these clusters would allow for a greater understanding of
disease progression in JIA, including how physician-reported and patient-reported outcomes relate to each other over
the JIA disease course. /
Methods: In this multicentre prospective longitudinal study, we included children and young people recruited before
Jan 1, 2015, to the Childhood Arthritis Prospective Study (CAPS), a UK multicentre inception cohort. Participants
without a cJADAS score were excluded. To assess groups of children and young people with similar disease patterns in
active joint count, physician’s global assessment, and patient or parental global evaluation, we used latent profile analysis
at initial presentation to paediatric rheumatology and multivariate group-based trajectory models for the following
3 years. Optimal models were selected on the basis of a combination of model fit, clinical plausibility, and model parsimony. /
Finding: Between Jan 1, 2001, and Dec 31, 2014, 1423 children and young people with JIA were recruited to CAPS,
239 of whom were excluded, resulting in a final study population of 1184 children and young people. We identified
five clusters at baseline and six trajectory groups using longitudinal follow-up data. Disease course was not well
predicted from clusters at baseline; however, in both cross-sectional and longitudinal analyses, substantial proportions
of children and young people had high patient or parent global scores despite low or improving joint counts and
physician global scores. Participants in these groups were older, and a higher proportion of them had enthesitisrelated JIA and lower socioeconomic status, compared with those in other groups. /
Interpretation: Almost one in four children and young people with JIA in our study reported persistent, high patient
or parent global scores despite having low or improving active joint counts and physician’s global scores. Distinct
patient subgroups defined by disease manifestation or trajectories of progression could help to better personalise
health-care services and treatment plans for individuals with JIA. /
Funding: Medical Research Council, Versus Arthritis, Great Ormond Street Hospital Children’s Charity, Olivia’s Vision,
and National Institute for Health Researc
Genetic Selection of Low Fertile Onchocerca volvulus by Ivermectin Treatment
Onchocerca volvulus is the causative agent of onchocerciasis, or
“river blindness”. Ivermectin has been used for mass
treatment of onchocerciasis for up to 18 years, and recently there have been
reports of poor parasitological responses to the drug and evidence of drug
resistance. Drug resistance has a genetic basis. In this study, genetic changes
in β-tubulin, a gene associated with ivermectin
resistance in nematodes, were seen in parasites obtained from the patients
exposed to repeated ivermectin treatment compared with parasites obtained from
the same patients before any exposure to ivermectin. Furthermore, the extent of
the genetic changes was dependent on the level of ivermectin treatment exposure.
This genetic selection was associated with a lower reproductive rate in the
female parasites. The data indicates that this genetic selection is for a
population of O. volvulus that is more tolerant to ivermectin.
This selection could have implications for the development of ivermectin
resistance in O. volvulus and for the ongoing onchocerciasis
control programmes. Monitoring for the possible development and spread of
ivermectin resistance, as part of the control programmes, should be implemented
so that any foci of resistant parasites can be treated by alternative control
measures
The successes and challenges of harmonising juvenile idiopathic arthritis (JIA) datasets to create a large-scale JIA data resource
Background
CLUSTER is a UK consortium focussed on precision medicine research in JIA/JIA-Uveitis. As part of this programme, a large-scale JIA data resource was created by harmonizing and pooling existing real-world studies. Here we present challenges and progress towards creation of this unique large JIA dataset.
Methods
Four real-world studies contributed data; two clinical datasets of JIA patients starting first-line methotrexate (MTX) or tumour necrosis factor inhibitors (TNFi) were created. Variables were selected based on a previously developed core dataset, and encrypted NHS numbers were used to identify children contributing similar data across multiple studies.
Results
Of 7013 records (from 5435 individuals), 2882 (1304 individuals) represented the same child across studies. The final datasets contain 2899 (MTX) and 2401 (TNFi) unique patients; 1018 are in both datasets. Missingness ranged from 10 to 60% and was not improved through harmonisation.
Conclusions
Combining data across studies has achieved dataset sizes rarely seen in JIA, invaluable to progressing research. Losing variable specificity and missingness, and their impact on future analyses requires further consideration
Engineered Single-Domain Antibodies with High Protease Resistance and Thermal Stability
The extreme pH and protease-rich environment of the upper gastrointestinal tract is a major obstacle facing orally-administered protein therapeutics, including antibodies. Through protein engineering, several Clostridium difficile toxin A-specific heavy chain antibody variable domains (VHHs) were expressed with an additional disulfide bond by introducing Ala/Gly54Cys and Ile78Cys mutations. Mutant antibodies were compared to their wild-type counterparts with respect to expression yield, non-aggregation status, affinity for toxin A, circular dichroism (CD) structural signatures, thermal stability, protease resistance, and toxin A-neutralizing capacity. The mutant VHHs were found to be well expressed, although with lower yields compared to wild-type counterparts, were non-aggregating monomers, retained low nM affinity for toxin A, albeit the majority showed somewhat reduced affinity compared to wild-type counterparts, and were capable of in vitro toxin A neutralization in cell-based assays. Far-UV and near-UV CD spectroscopy consistently showed shifts in peak intensity and selective peak minima for wild-type and mutant VHH pairs; however, the overall CD profile remained very similar. A significant increase in the thermal unfolding midpoint temperature was observed for all mutants at both neutral and acidic pH. Digestion of the VHHs with the major gastrointestinal proteases, at biologically relevant concentrations, revealed a significant increase in pepsin resistance for all mutants and an increase in chymotrypsin resistance for the majority of mutants. Mutant VHH trypsin resistance was similar to that of wild-type VHHs, although the trypsin resistance of one VHH mutant was significantly reduced. Therefore, the introduction of a second disulfide bond in the hydrophobic core not only increases VHH thermal stability at neutral pH, as previously shown, but also represents a generic strategy to increase VHH stability at low pH and impart protease resistance, with only minor perturbations in target binding affinities. These are all desirable characteristics for the design of protein-based oral therapeutics
Characterization of a pathway-specific activator of milbemycin biosynthesis and improved milbemycin production by its overexpression in Streptomyces bingchenggensis
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