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result(s) for
"Griffiths, Irene M."
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Genotype and Environment Affect the Grain Quality and Yield of Winter Oats (Avena sativa L.)
by
Cowan, Alexander A.
,
Clarke, Sarah
,
Sanderson, Ruth
in
Agricultural production
,
Avena sativa
,
Calibration
2021
The extent to which the quality and yield of plant varieties are influenced by the environment is important for their successful uptake by end users particularly as climatic fluctuations are resulting in environments that are highly variable from one growing season to another. The genotype-by-environment interaction (GEI) of milling quality and yield was studied using four winter oat varieties in multi-locational trials over 4 years in the U.K. Significant differences across the 22 environments were found between physical grain quality and composition as well as grain yield, with the environment having a significant effect on all of the traits measured. Grain yield was closely related to grain number m−2 whereas milling quality traits were related to grain size attributes. Considerable genotype by environment interaction was obtained for all grain quality traits and stability analysis revealed that the variety Mascani was the least sensitive to the environment for all milling quality traits measured whereas the variety Balado was the most sensitive. Examination of environmental conditions at specific within-year stages of crop development indicated that both temperature and rainfall during grain development were correlated with grain yield and β-glucan content and with the ease of removing the hull (hullability).
Journal Article
Effectiveness of spironolactone for women with acne vulgaris (SAFA) in England and Wales: pragmatic, multicentre, phase 3, double blind, randomised controlled trial
by
Santer, Miriam
,
Ridd, Matthew J
,
Soulsby, Irene
in
Acne
,
Acne Vulgaris - complications
,
Acne Vulgaris - drug therapy
2023
AbstractObjectiveTo assess the effectiveness of oral spironolactone for acne vulgaris in adult women.DesignPragmatic, multicentre, phase 3, double blind, randomised controlled trial.SettingPrimary and secondary healthcare, and advertising in the community and on social media in England and Wales.ParticipantsWomen (≥18 years) with facial acne for at least six months, judged to warrant oral antibiotics.InterventionsParticipants were randomly assigned (1:1) to either 50 mg/day spironolactone or matched placebo until week six, increasing to 100 mg/day spironolactone or placebo until week 24. Participants could continue using topical treatment.Main outcome measuresPrimary outcome was Acne-Specific Quality of Life (Acne-QoL) symptom subscale score at week 12 (range 0-30, where higher scores reflect improved QoL). Secondary outcomes were Acne-QoL at week 24, participant self-assessed improvement; investigator’s global assessment (IGA) for treatment success; and adverse reactions.ResultsFrom 5 June 2019 to 31 August 2021, 1267 women were assessed for eligibility, 410 were randomly assigned to the intervention (n=201) or control group (n=209) and 342 were included in the primary analysis (n=176 in the intervention group and n=166 in the control group). Baseline mean age was 29.2 years (standard deviation 7.2), 28 (7%) of 389 were from ethnicities other than white, with 46% mild, 40% moderate, and 13% severe acne. Mean Acne-QoL symptom scores at baseline were 13.2 (standard deviation 4.9) and at week 12 were 19.2 (6.1) for spironolactone and 12.9 (4.5) and 17.8 (5.6) for placebo (difference favouring spironolactone 1.27 (95% confidence interval 0.07 to 2.46), adjusted for baseline variables). Scores at week 24 were 21.2 (5.9) for spironolactone and 17.4 (5.8) for placebo (difference 3.45 (95% confidence interval 2.16 to 4.75), adjusted). More participants in the spironolactone group reported acne improvement than in the placebo group: no significant difference was reported at week 12 (72% v 68%, odds ratio 1.16 (95% confidence interval 0.70 to 1.91)) but significant difference was noted at week 24 (82% v 63%, 2.72 (1.50 to 4.93)). Treatment success (IGA classified) at week 12 was 31 (19%) of 168 given spironolactone and nine (6%) of 160 given placebo (5.18 (2.18 to 12.28)). Adverse reactions were slightly more common in the spironolactone group with more headaches reported (20% v 12%; p=0.02). No serious adverse reactions were reported.ConclusionsSpironolactone improved outcomes compared with placebo, with greater differences at week 24 than week 12. Spironolactone is a useful alternative to oral antibiotics for women with acne.Trial registrationISRCTN12892056
Journal Article
Alterations in DNA methylation associate with reduced migraine and headache days after medication withdrawal treatment in chronic migraine patients: a longitudinal study
by
Terwindt, Gisela M.
,
Nyholt, Dale R.
,
de Boer, Irene
in
Analgesics
,
Biomedical and Life Sciences
,
Biomedicine
2023
Background
Chronic migraine, a highly disabling migraine subtype, affects nearly 2% of the general population. Understanding migraine chronification is vital for developing better treatment and prevention strategies. An important factor in the chronification of migraine is the overuse of acute headache medication. However, the mechanisms behind the transformation of episodic migraine to chronic migraine and vice versa have not yet been elucidated. We performed a longitudinal epigenome-wide association study to identify DNA methylation (DNAm) changes associated with treatment response in patients with chronic migraine and medication overuse as part of the Chronification and Reversibility of Migraine clinical trial. Blood was taken from patients with chronic migraine (
n
= 98) at baseline and after a 12-week medication withdrawal period. Treatment responders, patients with ≥ 50% reduction in monthly headache days (MHD), were compared with non-responders to identify DNAm changes associated with treatment response. Similarly, patients with ≥ 50% versus < 50% reduction in monthly migraine days (MMD) were compared.
Results
At the epigenome-wide significant level (
p
< 9.42 × 10
–8
), a longitudinal reduction in DNAm at an intronic CpG site (cg14377273) within the
HDAC4
gene was associated with MHD response following the withdrawal of acute medication. HDAC4 is highly expressed in the brain, plays a major role in synaptic plasticity, and modulates the expression and release of several neuroinflammation markers which have been implicated in migraine pathophysiology. Investigating whether baseline DNAm associated with treatment response, we identified lower baseline DNAm at a CpG site (cg15205829) within
MARK3
that was significantly associated with MMD response at 12 weeks.
Conclusions
Our findings of a longitudinal reduction in
HDAC4
DNAm status associated with treatment response and baseline
MARK3
DNAm status as an early biomarker for treatment response, provide support for a role of pathways related to chromatin structure and synaptic plasticity in headache chronification and introduce
HDAC4
and
MARK3
as novel therapeutic targets.
Journal Article
An Aspartate-Specific Solute-Binding Protein Regulates Protein Kinase G Activity To Control Glutamate Metabolism in Mycobacteria
by
Nkumama, Irene Nailain
,
Price, Michael J.
,
Jarvis, Alexander R.
in
Actinobacteria
,
Amino acids
,
Antibiotics
2018
Signaling by serine/threonine phosphorylation controls diverse processes in bacteria, and identification of the stimuli that activate protein kinases is an outstanding question in the field. Recently, we showed that nutrients stimulate phosphorylation of the protein kinase G substrate GarA in Mycobacterium smegmatis and Mycobacterium tuberculosis and that the action of GarA in regulating central metabolism depends upon whether it is phosphorylated. Here we present an investigation into the mechanism by which nutrients activate PknG. Two unknown genes were identified as co-conserved and co-expressed with PknG: their products were a putative lipoprotein, GlnH, and putative transmembrane protein, GlnX. Using a genetic approach, we showed that the membrane protein GlnX is functionally linked to PknG. Furthermore, we determined that the ligand specificity of GlnH matches the amino acids that stimulate GarA phosphorylation. We determined the structure of GlnH in complex with different amino acid ligands (aspartate, glutamate, and asparagine), revealing the structural basis of ligand specificity. We propose that the amino acid concentration in the periplasm is sensed by GlnH and that protein-protein interaction allows transmission of this information across the membrane via GlnX to activate PknG. This sensory system would allow regulation of nutrient utilization in response to changes in nutrient availability. The sensor, signaling, and effector proteins are conserved throughout the Actinobacteria , including the important human pathogen Mycobacterium tuberculosis , industrial amino acid producer Corynebacterium glutamicum , and antibiotic-producing Streptomyces species. IMPORTANCE Tuberculosis (TB) kills 5,000 people every day, and the prevalence of multidrug-resistant TB is increasing in every country. The processes by which the pathogen Mycobacterium tuberculosis senses and responds to changes in its environment are attractive targets for drug development. Bacterial metabolism differs dramatically between growing and dormant cells, and these changes are known to be important in pathogenesis of TB. Here, we used genetic and biochemical approaches to identify proteins that allow M. tuberculosis to detect amino acids in its surroundings so that it can regulate its metabolism. We have also shown how individual amino acids are recognized. The findings have broader significance for other actinobacterial pathogens, such as nontuberculous mycobacteria, as well as Actinobacteria used to produce billions of dollars of amino acids and antibiotics every year. Tuberculosis (TB) kills 5,000 people every day, and the prevalence of multidrug-resistant TB is increasing in every country. The processes by which the pathogen Mycobacterium tuberculosis senses and responds to changes in its environment are attractive targets for drug development. Bacterial metabolism differs dramatically between growing and dormant cells, and these changes are known to be important in pathogenesis of TB. Here, we used genetic and biochemical approaches to identify proteins that allow M. tuberculosis to detect amino acids in its surroundings so that it can regulate its metabolism. We have also shown how individual amino acids are recognized. The findings have broader significance for other actinobacterial pathogens, such as nontuberculous mycobacteria, as well as Actinobacteria used to produce billions of dollars of amino acids and antibiotics every year.
Journal Article
Whole Exome Sequencing of Hemiplegic Migraine Patients Shows an Increased Burden of Missense Variants in CACNA1H and CACNA1I Genes
by
Ibrahim, Omar
,
Terwindt, Gisela M.
,
Vijfhuizen, Lisanne S.
in
Australia
,
Biomedical and Life Sciences
,
Biomedicine
2023
Hemiplegic migraine (HM) is a rare subtype of migraine with aura. Given that causal missense mutations in the voltage-gated calcium channel α1A subunit gene
CACNA1A
have been identified in a subset of HM patients, we investigated whether HM patients without a mutation have an increased burden of such variants in the “
CACNA1x
gene family”. Whole exome sequencing data of an Australian cohort of unrelated HM patients (
n
= 184), along with public data from gnomAD, as controls, was used to assess the burden of missense variants in
CACNA1x
genes. We performed both a variant and a subject burden test. We found a significant burden for the number of variants in
CACNA1E
(
p
= 1.3 × 10
−4
),
CACNA1H
(
p
< 2.2 × 10
−16
) and
CACNA1I
(
p
< 2.2 × 10
−16
). There was also a significant burden of subjects with missense variants in
CACNA1E
(
p
= 6.2 × 10
−3
),
CACNA1H
(
p
< 2.2 × 10
−16
) and
CACNA1I
(
p
< 2.2 × 10
−16
). Both the number of variants and number of subjects were replicated for
CACNA1H
(
p
= 3.5 × 10
−8
;
p
= 0.012) and
CACNA1I
(
p
= 0.019,
p
= 0.044), respectively, in a Dutch clinical HM cohort (
n
= 32), albeit that
CACNA1I
did not remain significant after multiple testing correction. Our data suggest that HM, in the absence of a single causal mutation, is a complex trait, in which an increased burden of missense variants in
CACNA1H
and
CACNA1I
may contribute to the risk of disease.
Journal Article
Cost-effectiveness of Spironolactone for Adult Female Acne (SAFA): economic evaluation alongside a randomised controlled trial
2023
ObjectiveThis study aims to estimate the cost-effectiveness of oral spironolactone plus routine topical treatment compared with routine topical treatment alone for persistent acne in adult women from a British NHS perspective over 24 weeks.DesignEconomic evaluation undertaken alongside a pragmatic, parallel, double-blind, randomised trial.SettingPrimary and secondary healthcare, community and social media advertising.ParticipantsWomen ≥18 years with persistent facial acne judged to warrant oral antibiotic treatment.InterventionsParticipants were randomised 1:1 to 50 mg/day spironolactone (increasing to 100 mg/day after 6 weeks) or matched placebo until week 24. Participants in both groups could continue topical treatment.Main outcome measuresCost-utility analysis assessed incremental cost per quality-adjusted life year (QALY) using the EQ-5D-5L. Cost-effectiveness analysis estimated incremental cost per unit change on the Acne-QoL symptom subscale. Adjusted analysis included randomisation stratification variables (centre, baseline severity (investigator’s global assessment, IGA <3 vs ≥3)) and baseline variables (Acne-QoL symptom subscale score, resource use costs, EQ-5D score and use of topical treatments).ResultsSpironolactone did not appear cost-effective in the complete case analysis (n=126 spironolactone, n=109 control), compared with no active systemic treatment (adjusted incremental cost per QALY £67 191; unadjusted £34 770). Incremental cost per QALY was £27 879 (adjusted), just below the upper National Institute for Health and Care Excellence’s threshold value of £30 000, where multiple imputation took account of missing data. Incremental cost per QALY for other sensitivity analyses varied around the base-case, highlighting the degree of uncertainty. The adjusted incremental cost per point change on the Acne-QoL symptom subscale for spironolactone compared with no active systemic treatment was £38.21 (complete case analysis).ConclusionsThe results demonstrate a high level of uncertainty, particularly with respect to estimates of incremental QALYs. Compared with no active systemic treatment, spironolactone was estimated to be marginally cost-effective where multiple imputation was performed but was not cost-effective in complete case analysis.Trial registration numberISRCTN registry (ISRCTN12892056).
Journal Article
Social media recruitment enhances participant diversity in dermatology clinical trial: findings from the SAFA trial
by
Santer, Miriam
,
Soulsby, Irene
,
Thomas, Karen
in
Acne
,
Acne Vulgaris - diagnosis
,
Acne Vulgaris - drug therapy
2025
Recruitment and retention of participants remain critical challenges in clinical trials, often requiring innovative approaches to ensure sufficient enrolment and sustained engagement. Social media advertising offers the potential to reach target populations quickly by leveraging demographic, geographic and interest-based targeting. This mixed-methods observational study evaluates participant experiences and the effectiveness of various recruitment routes within a trial of a treatment for acne. Demographic variables, including age, ethnicity, acne severity and acne duration, were stratified primary care, secondary care, community and social media recruitment routes and 12 participant interviews were analysed using reflexive thematic analysis. Social media recruitment accounted for over half of participants (53.9%). It was particularly effective in recruiting individuals with higher acne severity (IGA ≥ 3; 57.5% of its recruits,
n
= 127), longer duration of disease (> 5 years history of acne; 60.2% of its recruits,
n
= 133) and from ethnic minority groups (9.0% of its recruits,
n
= 20), the latter being notably higher than the proportion recruited via primary care (1.5% of its recruits,
n
= 1). Slight variations in retention by recruitment route were observed, with social media (85%) and primary care (84%) achieving the highest retention rate at the 12-week follow-up. All routes lost between 25 and 32% of participants by the 24-week follow-up, signifying the importance of implementing effective retention strategies to keep participants engaged. Overall, participants found targeted social media advertisements to be an acceptable and convenient recruitment approach; initial signals of trust were provided by high-quality graphics and recognisable NHS and university logos, which coupled with responsive trial staff, were suggested to provide a seamless enrolment experience. This study demonstrates that social media recruitment can be an effective and acceptable component of a multi-route strategy for clinical trial enrolment.
Journal Article
Spironolactone for adult female acne (SAFA): protocol for a double-blind, placebo-controlled, phase III randomised study of spironolactone as systemic therapy for acne in adult women
2021
IntroductionAcne is one of the most common inflammatory skin diseases worldwide and can have significant psychosocial impact and cause permanent scarring. Spironolactone, a potassium-sparing diuretic, has antiandrogenic properties, potentially reducing sebum production and hyperkeratinisation in acne-prone follicles. Dermatologists have prescribed spironolactone for acne in women for over 30 years, but robust clinical study data are lacking. This study seeks to evaluate whether spironolactone is clinically effective and cost-effective in treating acne in women.Methods and analysisWomen (≥18 years) with persistent facial acne requiring systemic therapy are randomised to receive one tablet per day of 50 mg spironolactone or a matched placebo until week 6, increasing to up to two tablets per day (total of 100 mg spironolactone or matched placebo) until week 24, along with usual topical therapy if desired. Study treatment stops at week 24; participants are informed of their treatment allocation and enter an unblinded observational follow-up period for up to 6 months (up to week 52 after baseline). Primary outcome is the Acne-specific Quality of Life (Acne-QoL) symptom subscale score at week 12. Secondary outcomes include Acne-QoL total and subscales; participant acne self-assessment recorded on a 6-point Likert scale at 6, 12, 24 weeks and up to 52 weeks; Investigator’s Global Assessment at weeks 6 and 12; cost and cost effectiveness are assessed over 24 weeks. Aiming to detect a group difference of 2 points on the Acne-QoL symptom subscale (SD 5.8, effect size 0.35), allowing for 20% loss to follow-up, gives a sample size of 398 participants.Ethics and disseminationThis protocol was approved by Wales Research Ethics Committee (18/WA/0420). Follow-up to be completed in early 2022. Findings will be disseminated to participants, peer-reviewed journals, networks and patient groups, on social media, on the study website and the Southampton Clinical Trials Unit website to maximise impact.Trial registration numberISRCTN12892056;Pre-results.
Journal Article
Beyond the genomes of Fulvia fulva (syn. Cladosporium fulvum) and Dothistroma septosporum: New insights into how these fungal pathogens interact with their host plants
by
Schol, Christiaan R.
,
Wit, Pierre J. G. M.
,
Bradshaw, Rosie E.
in
Blight
,
Cell surface
,
Chromosomes
2023
Fulvia fulva and Dothistroma septosporum are closely related apoplastic pathogens with similar lifestyles but different hosts: F. fulva is a pathogen of tomato, whilst D. septosporum is a pathogen of pine trees. In 2012, the first genome sequences of these pathogens were published, with F. fulva and D. septosporum having highly fragmented and near‐complete assemblies, respectively. Since then, significant advances have been made in unravelling their genome architectures. For instance, the genome of F. fulva has now been assembled into 14 chromosomes, 13 of which have synteny with the 14 chromosomes of D. septosporum, suggesting these pathogens are even more closely related than originally thought. Considerable advances have also been made in the identification and functional characterization of virulence factors (e.g., effector proteins and secondary metabolites) from these pathogens, thereby providing new insights into how they promote host colonization or activate plant defence responses. For example, it has now been established that effector proteins from both F. fulva and D. septosporum interact with cell‐surface immune receptors and co‐receptors to activate the plant immune system. Progress has also been made in understanding how F. fulva and D. septosporum have evolved with their host plants, whilst intensive research into pandemics of Dothistroma needle blight in the Northern Hemisphere has shed light on the origins, migration, and genetic diversity of the global D. septosporum population. In this review, we specifically summarize advances made in our understanding of the F. fulva–tomato and D. septosporum–pine pathosystems over the last 10 years. In this review we summarize advances from the last decade in understanding the molecular basis of how the closely related fungal pathogens Fulvia fulva and Dothistroma septosporum interact with their respective tomato and pine hosts.
Journal Article
Clinical and Genetic Heterogeneity of Erythrokeratoderma Variabilis
by
O'Toole, Edel A.
,
Leigh, Irene M.
,
Grabczynska, Sophie
in
Biological and medical sciences
,
connexin
,
Connexins - genetics
2005
The skin disease erythrokeratoderma variabilis (EKV) has been shown to be associated with mutations in GJB3 and GJB4 encoding connexin (Cx)31 and Cx30.3, respectively. Gap junctions composed of Cx proteins are intracellular channels providing a mechanism of synchronized cellular response facilitating metabolic and electronic functions of the cell. In the skin, Cx31 and Cx30.3 are expressed in the stratum granulosum of the epidermis with a suggested role in late keratinocyte differentiation. Molecular investigations of GJB3 and GJB4 were performed in five pedigrees and three sporadic cases of EKV. Mutational analyzes revealed disease-associated Cx31 or Cx30.3 mutations in only three probands of which two were novel mutations and one was a recurrent mutation. These genetic studies further demonstrate the heterogeneous nature of the erythrokeratodermas as not all individuals that were clinically diagnosed with EKV harbor Cx31 or Cx30.3 mutations.
Journal Article