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1.
J Autoimmun ; 147: 103263, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38851089

ABSTRACT

RATIONALE: In inflammatory diseases such as rheumatoid arthritis (RA), steroid metabolism is a central component mediating the actions of immuno-modulatory glucocorticoids and sex steroids. However, the regulation and function of cellular steroid metabolism within key leukocyte populations such as macrophages remain poorly defined. In this study, the inflammatory regulation of global steroid metabolism was assessed in RA macrophages. METHODS: Bulk RNA-seq data from RA synovial macrophages was used to assess transcripts encoding key enzymes in steroid metabolism and signalling. Changes in metabolism were assessed in synovial fluids, correlated to measures of disease activity and functionally validated in primary macrophage cultures. RESULTS: RNA-seq revealed a unique pattern of differentially expressed genes, including changes in genes encoding the enzymes 11ß-HSD1, SRD5A1, AKR1C2 and AKR1C3. These correlated with disease activity, favouring increased glucocorticoid and androgen levels. Synovial fluid 11ß-HSD1 activity correlated with local inflammatory mediators (TNFα, IL-6, IL-17), whilst 11ß-HSD1, SRD5A1 and AKR1C3 activity correlated with systemic measures of disease and patient pain (ESR, DAS28 ESR, global disease activity). Changes in enzyme activity were evident in inflammatory activated macrophages in vitro and revealed a novel androgen activating role for 11ß-HSD1. Together, increased glucocorticoids and androgens were able to suppress inflammation in macrophages and fibroblast-like-synoviocytes. CONCLUSIONS: This study underscores the significant increase in androgen and glucocorticoid activation within inflammatory polarized macrophages of the synovium, contributing to local suppression of inflammation. The diminished profile of inactive steroid precursors in postmenopausal women may contribute to disturbances in this process, leading to increased disease incidence and severity.


Subject(s)
11-beta-Hydroxysteroid Dehydrogenase Type 1 , Arthritis, Rheumatoid , Inflammation , Macrophages , Humans , Arthritis, Rheumatoid/metabolism , Arthritis, Rheumatoid/immunology , Arthritis, Rheumatoid/pathology , Macrophages/metabolism , Macrophages/immunology , Inflammation/metabolism , Inflammation/immunology , 11-beta-Hydroxysteroid Dehydrogenase Type 1/metabolism , 11-beta-Hydroxysteroid Dehydrogenase Type 1/genetics , Aldo-Keto Reductase Family 1 Member C3/metabolism , Synovial Fluid/metabolism , Synovial Fluid/immunology , 3-Oxo-5-alpha-Steroid 4-Dehydrogenase/metabolism , 3-Oxo-5-alpha-Steroid 4-Dehydrogenase/genetics , Membrane Proteins/metabolism , Membrane Proteins/genetics , Male , Female , Synovial Membrane/metabolism , Synovial Membrane/pathology , Synovial Membrane/immunology , Cells, Cultured , Glucocorticoids/metabolism , Steroids/metabolism , Gene Expression Regulation , Hydroxysteroid Dehydrogenases
2.
Eur J Endocrinol ; 186(4): 441-455, 2022 Feb 28.
Article in English | MEDLINE | ID: mdl-35113805

ABSTRACT

BACKGROUND: Chronic wounds (e.g. diabetic foot ulcers) reduce the quality of life, yet treatments remain limited. Glucocorticoids (activated by the enzyme 11ß-hydroxysteroid dehydrogenase type 1, 11ß-HSD1) impair wound healing. OBJECTIVES: Efficacy, safety, and feasibility of 11ß-HSD1 inhibition for skin function and wound healing. DESIGN: Investigator-initiated, double-blind, randomized, placebo-controlled, parallel-group phase 2b pilot trial. METHODS: Single-center secondary care setting. Adults with type 2 diabetes mellitus without foot ulcers were administered 400 mg oral 11ß-HSD1 inhibitor AZD4017 (n = 14) or placebo (n = 14) bi-daily for 35 days. Participants underwent 3-mm full-thickness punch skin biopsies at baseline and on day 28; wound healing was monitored after 2 and 7 days. Computer-generated 1:1 randomization was pharmacy-administered. Analysis was descriptive and focused on CI estimation. Of the 36 participants screened, 28 were randomized. RESULTS: Exploratory proof-of-concept efficacy analysis suggested AZD4017 did not inhibit 24-h ex vivoskin 11ß-HSD1 activity (primary outcome; difference in percentage conversion per 24 h 1.1% (90% CI: -3.4 to 5.5) but reduced systemic 11ß-HSD1 activity by 87% (69-104%). Wound diameter was 34% (7-63%) smaller with AZD4017 at day 2, and 48% (12-85%) smaller after repeat wounding at day 30. AZD4017 improved epidermal integrity but modestly impaired barrier function. Minimal adverse events were comparable to placebo. Recruitment rate, retention, and data completeness were 2.9/month, 27/28, and 95.3%, respectively. CONCLUSION: A phase 2 trial is feasible, and preliminary proof-of-concept data suggests AZD4017 warrants further investigation in conditions of delayed healing, for example in diabetic foot ulcers. SIGNIFICANCE STATEMENT: Stress hormone activation by the enzyme 11ß-HSD type 1 impairs skin function (e.g. integrity) and delays wound healing in animal models of diabetes, but effects in human skin were previously unknown. Skin function was evaluated in response to treatment with a 11ß-HSD type 1 inhibitor (AZD4017), or placebo, in people with type 2 diabetes. Importantly, AZD4017 was safe and well tolerated. This first-in-human randomized, controlled, clinical trial found novel evidence that 11ß-HSD type 1 regulates skin function in humans, including improved wound healing, epidermal integrity, and increased water loss. Results warrant further studies in conditions of impaired wound healing, for example, diabetic foot ulcers to evaluate 11ß-HSD type 1 as a novel therapeutic target forchronic wounds.


Subject(s)
11-beta-Hydroxysteroid Dehydrogenase Type 1/antagonists & inhibitors , Diabetes Mellitus, Type 2/complications , Diabetic Foot/drug therapy , Niacinamide/analogs & derivatives , Piperidines/therapeutic use , Skin/drug effects , Wound Healing/drug effects , Adult , Aged , Aged, 80 and over , Diabetic Foot/pathology , Double-Blind Method , Epidermis/drug effects , Epidermis/pathology , Female , Humans , Male , Middle Aged , Niacinamide/therapeutic use , Pilot Projects , Quality of Life , Skin/pathology , Skin/physiopathology , Treatment Outcome
3.
Clin Oncol (R Coll Radiol) ; 32(4): 228-237, 2020 04.
Article in English | MEDLINE | ID: mdl-31668378

ABSTRACT

AIMS: To evaluate patterns of locoregional recurrence following adjuvant (chemo)radiotherapy for oral cavity squamous cell carcinomas. MATERIALS AND METHODS: One hundred and one patients who received adjuvant radiotherapy ± chemotherapy for oral cavity squamous cell carcinoma between 2013 and 2016 were analysed. For documented locoregional recurrence, recurrence imaging was deformably co-registered to the planning computed tomography scan. The volume of recurrence was delineated (Vrec). Vrec coverage by 95% of the corresponding planning target volume prescription dose was determined and the location compared with planning target volumes. Sites of recurrence were classified using a combined volume and centroid-based method: (A) central high dose, (B) peripheral high dose, (C) central low dose, (D) central peripheral dose, (E) extraneous. RESULTS: The median follow-up was 36 months. Forty-three per cent and 53% of patients received radiotherapy to the ipsilateral neck only and bilateral neck, respectively. Three-year overall survival, disease-free survival, local control, regional control and distant metastases-free survival were 63.0, 65.6, 88.0, 85.1 and 85.3%, respectively. Of 10 episodes of primary site recurrences, five were type A, four type B and one was type E. Of 14 episodes of regional recurrence, five were type A, two type C, two type D and five type E. Five of 21 (24%) patients with oral tongue carcinoma with an undissected/unirradiated contralateral neck had a type E contralateral neck recurrence, including 2/11 with pN0, 1/4 with pN1 and 2/6 with pN2 disease. CONCLUSIONS: Marginal and out-of-field recurrences remain a significant pattern of failure. We advocate generous target delineation postoperatively and, for oral tongue carcinomas, a comprehensive approach with bilateral neck irradiation.


Subject(s)
Mouth Neoplasms/diet therapy , Mouth Neoplasms/radiotherapy , Neoplasm Recurrence, Local/pathology , Radiotherapy, Adjuvant/methods , Adult , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Mouth Neoplasms/mortality , Mouth Neoplasms/pathology , Retrospective Studies , Survival Analysis , Young Adult
4.
J R Soc Interface ; 16(150): 20180572, 2019 01 31.
Article in English | MEDLINE | ID: mdl-30958174

ABSTRACT

We introduce a Bayesian prior distribution, the logit-normal continuous analogue of the spike-and-slab, which enables flexible parameter estimation and variable/model selection in a variety of settings. We demonstrate its use and efficacy in three case studies-a simulation study and two studies on real biological data from the fields of metabolomics and genomics. The prior allows the use of classical statistical models, which are easily interpretable and well known to applied scientists, but performs comparably to common machine learning methods in terms of generalizability to previously unseen data.


Subject(s)
Algorithms , Computer Simulation , Genomics , Models, Biological , Humans
5.
R Soc Open Sci ; 6(3): 181133, 2019 Mar.
Article in English | MEDLINE | ID: mdl-31031995

ABSTRACT

Individuals appraise events as a consequence of their own actions (i.e. internal locus of control, LoC) or as the outcome of chance or others' will (i.e. external LoC). We hypothesized that having a more external LoC would be associated with higher risk of tobacco and alcohol use. Few studies have examined this association using large prospective data. We evaluated within the Avon Longitudinal Study of Parents and Children (ALSPAC) the associations between LoC at 16 and tobacco and alcohol consumption at 17 and 21 years using logistic regression. A more external LoC at age 16 (N = 4656) was associated with higher odds of being a weekly smoker at age 17 (OR 1.18, 95% CI 1.10-1.25) and 21 (OR 1.14, 95% CI 1.07-1.21) and with dependence measured using the Fagerström Test of Nicotine Dependence at age 17 (OR 1.26, 95% CI 1.05-1.51) and 21 (OR 1.25, 95% CI 1.05-1.49). Individuals with external LoC at age 16 were more likely to be hazardous drinkers according to the Alcohol Use Disorders Identification Test at age 17 (OR 1.09, 95% CI 1.04-1.15) but not at 21 (OR 1.01, 95% CI 0.96-1.06). Having a more external LoC at age 16 is associated with increased tobacco consumption at age 17 and 21 and alcohol consumption at 17 years. LoC may represent an intervention target for preventing substance use and dependence.

6.
J Phys Condens Matter ; 30(45): 455801, 2018 Nov 14.
Article in English | MEDLINE | ID: mdl-30256218

ABSTRACT

The breathing pyrochlore lattice material Ba3Yb2Zn5O11 exists in the nearly decoupled limit, in contrast to most other well-studied breathing pyrochlore compounds. As a result, it constitutes a useful platform to benchmark theoretical calculations of exchange interactions in insulating Yb3+ magnets. Here we study Ba3Yb2Zn5O11 at low temperatures in applied magnetic fields as a further probe of the physics of this model system. Experimentally, we consider the behavior of polycrystalline samples of Ba3Yb2Zn5O11 with a combination of inelastic neutron scattering and heat capacity measurements down to 75 mK and up to fields of 10 T. Consistent with previous work, inelastic neutron scattering finds a level crossing near 3 T, but no significant dispersion of the spin excitations is detected up to the highest applied fields. Refinement of the theoretical model previously determined at zero field can reproduce much of the inelastic neutron scattering spectra and specific heat data. A notable exception is a low temperature peak in the specific heat at ∼0.1 K. This may indicate the scale of interactions between tetrahedra or may reflect undetected disorder in Ba3Yb2Zn5O11.

7.
Hum Reprod ; 33(9): 1727-1734, 2018 09 01.
Article in English | MEDLINE | ID: mdl-30020477

ABSTRACT

STUDY QUESTION: What information does androgen profiling using liquid chromatography tandem mass spectrometry (LC-MS/MS) provide in reproductive-age women with Type 1 diabetes (T1D)? SUMMARY ANSWER: In T1D women, androstenedione proved most useful of the measured androgens in differentiating subgroups based on clinical phenotypes of hyperandrogenism (HA) and polycystic ovary syndrome (PCOS). WHAT IS KNOWN ALREADY: The prevalence of HA and PCOS are increased in women with T1D. These observations are based on measurement of serum androgens using immunoassays, to-date no studies using LC-MS/MS have been reported in reproductive-age women with T1D. STUDY DESIGN, SIZE, DURATION: This was a cross-sectional study with recruitment of three groups of reproductive-age women: women with T1D (n = 87), non-diabetic women with (N = 97) and without PCOS (N = 101). PARTICIPANTS/MATERIALS, SETTING, METHODS: Using LC-MS/MS, we aimed to characterize androgen profiles and PCOS status in women with T1D, and interpret findings in relation to cohorts of non-diabetic women with and without PCOS. MAIN RESULTS AND THE ROLE OF CHANCE: Compared to non-diabetic women, dehydroepiandrosterone/dehydroepiandrosterone sulphate (DHEA/DHEAS) ratio was lower (P < 0.05) in women with T1D. Testosterone levels were greater in T1D women with clinical HA and anovulation compared to those without clinical HA and with regular cycles, while androstenedione levels were greater in T1D women with HA and anovulation compared to those with HA and regular cycles and also those without HA and with regular cycles (P < 0.05 for all). Compared to T1D women without PCOS, the 18% of T1D women who had PCOS were younger with lower BMI, an older age of menarche, and were more likely to have a positive family history of PCOS (P < 0.05 for all). Androgen levels did not differ between women with T1D and PCOS compared to BMI-matched non-diabetic women with PCOS, but androstenedione levels were greater in T1D women with PCOS compared to obese women with PCOS (P < 0.05). LIMITATIONS, REASONS FOR CAUTION: Relatively small subgroups of patients were studied, reducing the power to detect small differences. Free testosterone levels were not measured using equilibrium dialysis, and were not calculated - commonly used formulae have not been validated in T1D. WIDER IMPLICATIONS OF THE FINDINGS: Androstenedione is a sensitive biochemical marker of clinical hyperandrogenism and PCOS in T1D. T1D women with PCOS are leaner than those without PCOS but are more likely to have a family history of PCOS. Women with T1D and PCOS have a similar biochemical phenotype to lean non-diabetic women with PCOS but differ from obese women with PCOS. The mechanisms underlying PCOS in T1D and its clinical significance require further investigation. STUDY FUNDING/COMPETING INTEREST(S): The study was part-funded by the Meath Foundation. The authors have no competing interests.


Subject(s)
Androgens/blood , Dehydroepiandrosterone Sulfate/blood , Diabetes Mellitus, Type 1/blood , Testosterone/blood , Adult , Biomarkers/blood , Body Mass Index , Case-Control Studies , Chromatography, Liquid , Cross-Sectional Studies , Diabetes Mellitus, Type 1/complications , Female , Humans , Hyperandrogenism/blood , Hyperandrogenism/complications , Polycystic Ovary Syndrome/blood , Polycystic Ovary Syndrome/complications , Tandem Mass Spectrometry
8.
Br Poult Sci ; 59(5): 554-561, 2018 Oct.
Article in English | MEDLINE | ID: mdl-29855193

ABSTRACT

1. The aim of this study was to evaluate the effects of phytase and xylanase and their interaction on laying hen performance, egg quality, phosphorus (P) digestibility, phytate breakdown, volatile fatty acid (VFA) production and peptide YY concentration. 2. Two hundred and forty hens were allocated to cages at 22 weeks of age based on a 3 × 2 arrangement with phytase (0, 300 or 1500 FTU/kg) and xylanase (0 or 12 000 BXU/kg) as factors. 3. Phytase increased hen-day production (P < 0.05), daily egg mass (P < 0.05) and P digestibility with increasing levels of phytase (P < 0.001). Phytase fed at 1500 FTU/kg reduced IP6 and IP5 and increased myo-inositol concentration in gizzard digesta (P < 0.05). Phytase fed at 300 FTU/kg reduced IP6 in ileal digesta (P < 0.05); however, IP6 and IP5 were further reduced and myo-inositol increased when phytase was added at 1500 FTU/kg (P < 0.05). 4. Xylanase improved feed efficiency when phytase was fed at 300 FTU/kg (P < 0.05). In the absence of phytase, xylanase reduced dry matter and Ca digestibilities (P < 0.05). 5. Neither phytase nor xylanase had an effect on peptide YY or caecal VFA concentrations.


Subject(s)
6-Phytase/pharmacology , Chickens/physiology , Eggs/standards , Endo-1,4-beta Xylanases/pharmacology , Food Additives/pharmacology , Animal Feed , Animal Nutritional Physiological Phenomena/drug effects , Animals , Chickens/growth & development , Diet , Digestion , Female , Phosphorus, Dietary/metabolism
9.
Animal ; 12(12): 2499-2504, 2018 Dec.
Article in English | MEDLINE | ID: mdl-29508681

ABSTRACT

Non-starch polysaccharides (NSP) present in wheat and barley can act as anti-nutrients leading to an increase in digesta viscosity and a reduction in nutrient digestibility. Xylanase, an NSP-degrading enzyme, has been shown to increase nutrient digestibility in pigs. The objectives of this study were: (1) to identify the optimum inclusion level of xylanase in grower pig diets by measuring the effect of increasing enzyme levels on growth performance, the concentration of volatile fatty acids (VFA) and peptide YY concentration in portal and peripheral blood of grower pigs and (2) to increase our understanding of the interrelationships between xylanase inclusion, VFA production and peptide YY secretion. A total of 512 grower pigs ((Large White×Landrace)×MAXGRO) were allocated to pens creating 32 replicates of four pigs per pen per treatment. Pigs were allocated to trial weighing 14.2±0.31 kg and remained on trial until ~41.5±3.31 kg. The experiment was a dose response design with four inclusion levels (0, 8000, 16 000 or 32 000 BXU/kg) of xylanase (Econase XT). Diets were cereal-based wheat, barley mix formulated to meet or exceed the nutrient requirements of grower pigs. Body weight and feed intake were recorded to calculate growth performance. Pen faecal samples were collected to estimate DM, organic matter (OM) and crude fibre (CF) apparent total-tract digestibility. At the end of the trial 16 pigs per treatment were euthanised by schedule 1 procedures. Peripheral and portal blood samples were collected for peptide YY and VFA analysis. The addition of xylanase to the diet had no effect on growth performance, DM, OM or CF total-tract digestibility; however, xylanase tended to have a quadratic effect on ileum pH with higher pH values recorded for pigs fed a diet supplemented with 8000 and 16 000 BXU/kg xylanase (P<0.1). Xylanase had no effect on peptide YY levels or VFA concentration. Total VFA concentration was higher in portal compared with peripheral blood (P<0.05). In conclusion, the addition of xylanase had no effect on grower pig performance, nutrient digestibility, VFA concentration or peptide YY concentration when fed up to 32 000 BXU/kg over a 35-day period. Pig performance was good for all treatments throughout the trial suggesting that diet quality was sufficient thus there were no beneficial effects of adding xylanase.


Subject(s)
Animal Feed/analysis , Dietary Supplements , Endo-1,4-beta Xylanases/administration & dosage , Fatty Acids, Volatile/blood , Peptide YY/blood , Swine/physiology , Animals , Body Weight/drug effects , Diet/veterinary , Digestion/drug effects , Edible Grain , Fatty Acids, Volatile/metabolism , Feces/chemistry , Female , Gastrointestinal Tract/metabolism , Hordeum , Male , Peptide YY/metabolism , Random Allocation , Swine/growth & development , Triticum
10.
Allergy ; 73(1): 153-164, 2018 Jan.
Article in English | MEDLINE | ID: mdl-28675761

ABSTRACT

BACKGROUND: Observational studies have shown that body mass index (BMI) is positively associated with asthma. However, observational data are prone to confounding and reverse causation. In Mendelian randomization, genetic variants are used as unconfounded markers of exposures to examine causal effects. We examined the causal effect of BMI on asthma, hay fever, allergic sensitization, serum total immunoglobulin E (IgE), forced expiratory volume in one-second (FEV1) and forced vital capacity (FVC). METHODS: We included 490 497 participants in the observational and 162 124 participants in the genetic analyses. A genetic risk score (GRS) was created using 26 BMI-associated single nucleotide polymorphisms (SNPs). Results were pooled in meta-analyses and expressed as odds ratios (ORs) or ß-estimates with 95% confidence interval (CI). RESULTS: The GRS was significantly associated with asthma (OR=1.009; 95% CI: 1.004, 1.013), but not with hay fever (OR= 0.998; 95% CI: 0.994, 1.002) or allergic sensitization (OR=0.999; 95% CI: 0.986, 1.012) per BMI-increasing allele. The GRS was significantly associated with decrease in FEV1: ß=-0.0012 (95% CI: -0.0019, -0.0006) and FVC: ß=-0.0022 (95% CI: -0.0031, -0.0014) per BMI-increasing allele. Effect sizes estimated by instrumental variable analyses were OR=1.07 (95% CI: 1.03, 1.10) for asthma, a 9 ml decrease in FEV1 (95% CI: 2.0-15 mL decrease) and a 16 ml decrease in FVC (95% CI: 7.0-24 mL decrease) per 1 kg/m2 higher BMI. CONCLUSIONS: The results support the conclusion that increasing BMI is causally related to higher prevalence of asthma and decreased lung function, but not with hay fever or biomarkers of allergy.


Subject(s)
Asthma/etiology , Asthma/physiopathology , Body Mass Index , Respiratory Function Tests , Rhinitis, Allergic, Seasonal/etiology , Rhinitis, Allergic, Seasonal/physiopathology , Adult , Alleles , Asthma/epidemiology , Female , Forced Expiratory Volume , Genetic Predisposition to Disease , Genotype , Humans , Immunoglobulin E/immunology , Male , Middle Aged , Odds Ratio , Polymorphism, Single Nucleotide , Rhinitis, Allergic, Seasonal/epidemiology
11.
Phys Rev Lett ; 118(20): 207202, 2017 May 19.
Article in English | MEDLINE | ID: mdl-28581789

ABSTRACT

Entanglement of spin and orbital degrees of freedom drives the formation of novel quantum and topological physical states. Here we report resonant inelastic x-ray scattering measurements of the transition metal oxides Ca_{3}LiOsO_{6} and Ba_{2}YOsO_{6}, which reveals a dramatic spitting of the t_{2g} manifold. We invoke an intermediate coupling approach that incorporates both spin-orbit coupling and electron-electron interactions on an even footing and reveal that the ground state of 5d^{3}-based compounds, which has remained elusive in previously applied models, is a novel spin-orbit entangled J=3/2 electronic ground state. This work reveals the hidden diversity of spin-orbit controlled ground states in 5d systems and introduces a new arena in the search for spin-orbit controlled phases of matter.

12.
Phys Rev Lett ; 117(17): 176603, 2016 Oct 21.
Article in English | MEDLINE | ID: mdl-27824456

ABSTRACT

The perovskite SrIrO_{3} is an exotic narrow-band metal owing to a confluence of the strengths of the spin-orbit coupling (SOC) and the electron-electron correlations. It has been proposed that topological and magnetic insulating phases can be achieved by tuning the SOC, Hubbard interactions, and/or lattice symmetry. Here, we report that the substitution of nonmagnetic, isovalent Sn^{4+} for Ir^{4+} in the SrIr_{1-x}Sn_{x}O_{3} perovskites synthesized under high pressure leads to a metal-insulator transition to an antiferromagnetic (AF) phase at T_{N}≥225 K. The continuous change of the cell volume as detected by x-ray diffraction and the λ-shape transition of the specific heat on cooling through T_{N} demonstrate that the metal-insulator transition is of second order. Neutron powder diffraction results indicate that the Sn substitution enlarges an octahedral-site distortion that reduces the SOC relative to the spin-spin exchange interaction and results in the type-G AF spin ordering below T_{N}. Measurement of high-temperature magnetic susceptibility shows the evolution of magnetic coupling in the paramagnetic phase typical of weak itinerant-electron magnetism in the Sn-substituted samples. A reduced structural symmetry in the magnetically ordered phase leads to an electron gap opening at the Brillouin zone boundary below T_{N} in the same way as proposed by Slater.

13.
Phys Rev Lett ; 116(25): 257204, 2016 Jun 24.
Article in English | MEDLINE | ID: mdl-27391749

ABSTRACT

The low energy spin excitation spectrum of the breathing pyrochlore Ba_{3}Yb_{2}Zn_{5}O_{11} has been investigated with inelastic neutron scattering. Several nearly resolution limited modes with no observable dispersion are observed at 250 mK while, at elevated temperatures, transitions between excited levels become visible. To gain deeper insight, a theoretical model of isolated Yb^{3+} tetrahedra parametrized by four anisotropic exchange constants is constructed. The model reproduces the inelastic neutron scattering data, specific heat, and magnetic susceptibility with high fidelity. The fitted exchange parameters reveal a Heisenberg antiferromagnet with a very large Dzyaloshinskii-Moriya interaction. Using this model, we predict the appearance of an unusual octupolar paramagnet at low temperatures and speculate on the development of intertetrahedron correlations.

14.
Br J Dermatol ; 174(3): 594-601, 2016 Mar.
Article in English | MEDLINE | ID: mdl-26473312

ABSTRACT

BACKGROUND: Oral propranolol is widely prescribed as first-line treatment for infantile haemangiomas (IHs). Anecdotally, prescribing practice differs widely between centres. OBJECTIVES: The Propranolol In the Treatment of Complicated Haemangiomas (PITCH) Taskforce was founded to establish patterns of use of propranolol in IHs. METHODS: Participating centres entered data on all of their patients who had completed treatment with oral propranolol for IHs, using an online data capture tool. RESULTS: The study cohort comprised 1097 children from 39 centres in eight European countries. 76·1% were female and 92·8% had a focal IH, with the remainder showing a segmental, multifocal or indeterminate pattern. The main indications for treatment were periocular location (29·3%), risk of cosmetic disfigurement (21·1%) and ulceration and bleeding (20·6%). In total 69·2% of patients were titrated up to a maintenance regimen, which consisted of 2 mg kg(-1) per day (85·8%) in the majority of cases. 91·4% of patients had an excellent or good response to treatment. Rebound growth occurred in 14·1% upon stopping, of whom 53·9% were restarted and treatment response was recaptured in 91·6% of cases. While there was no significant difference in the treatment response, comparing a daily maintenance dose of < 2 mg kg(-1) vs. 2 mg kg(-1) vs. > 2 mg kg(-1) , the risk of adverse events was significantly higher: odds ratio (OR) 1 vs. adjusted OR 0·70, 95% confidence interval (CI) 0·33-1·50, P = 0·36 vs. OR 2·38, 95% CI 1·04-5·46, P = 0·04, Ptrend < 0·001. CONCLUSIONS: The PITCH survey summarizes the use of oral propranolol across 39 European centres, in a variety of IH phases, and could be used to inform treatment guidelines and the design of an interventional study.


Subject(s)
Antineoplastic Agents/administration & dosage , Hemangioma/drug therapy , Propranolol/administration & dosage , Skin Neoplasms/drug therapy , Administration, Oral , Antineoplastic Agents/adverse effects , Dose-Response Relationship, Drug , Female , Humans , Infant , Male , Propranolol/adverse effects , Treatment Outcome
16.
Appl Environ Microbiol ; 81(6): 1942-8, 2015 Mar.
Article in English | MEDLINE | ID: mdl-25576608

ABSTRACT

A previous study showed that ammonia oxidation by the Thaumarchaeota Nitrosopumilus maritimus (group 1.1a) was resistant to concentrations of the C8 1-alkyne, octyne, which completely inhibits activity by ammonia-oxidizing bacteria. In this study, the inhibitory effects of octyne and other C2 to C10 1-alkynes were evaluated on the nitrite production activity of two pure culture isolates from Thaumarchaeota group 1.1b, Nitrososphaera viennensis strain EN76 and Nitrososphaera gargensis. Both N. viennensis and N. gargensis were insensitive to concentrations of octyne that cause complete and irreversible inactivation of nitrite production by ammonia-oxidizing bacteria. However, octyne concentrations (≥20 µM) that did not inhibit N. maritimus partially inhibited nitrite production in N. viennensis and N. gargensis in a manner that did not show the characteristics of irreversible inactivation. In contrast to previous studies with an ammonia-oxidizing bacterium, Nitrosomonas europaea, octyne inhibition of N. viennensis was: (i) fully and immediately reversible, (ii) not competitive with NH4 (+), and (iii) without effect on the competitive interaction between NH4 (+) and acetylene. Both N. viennensis and N. gargensis demonstrated the same overall trend in regard to 1-alkyne inhibition as previously observed for N. maritimus, being highly sensitive to ≤C5 alkynes and more resistant to longer-chain length alkynes. Reproducible differences were observed among N. maritimus, N. viennensis, and N. gargensis in regard to the extent of their resistance/sensitivity to C6 and C7 1-alkynes, which may indicate differences in the ammonia monooxygenase binding and catalytic site(s) among the Thaumarchaeota.


Subject(s)
Alkynes/metabolism , Ammonia/metabolism , Archaea/metabolism , Nitrites/metabolism , Oxidation-Reduction
17.
J Phys Condens Matter ; 27(1): 015602, 2015 Jan 14.
Article in English | MEDLINE | ID: mdl-25469766

ABSTRACT

Electric resistivity, specific heat, magnetic susceptibility, and inelastic neutron scattering experiments were performed on a single crystal of the heavy fermion compound Ce(Ni0.935Pd0.065)2Ge2 in order to study the spin fluctuations near an antiferromagnetic (AF) quantum critical point (QCP). The resistivity and the specific heat coefficient for T ⩽ 1 K exhibit the power law behavior expected for a 3D itinerant AF QCP (ρ(T) ∼ T(3/2) and γ(T) ∼ γ0 - bT(1/2)). However, for 2 ⩽ T ⩽ 10 K, the susceptibility and specific heat vary as log T and the resistivity varies linearly with temperature. Furthermore, despite the fact that the resistivity and specific heat exhibit the non-Fermi liquid behavior expected at a QCP, the correlation length, correlation time, and staggered susceptibility of the spin fluctuations remain finite at low temperature. We suggest that these deviations from the divergent behavior expected for a QCP may result from alloy disorder.

18.
Br J Dermatol ; 170(1): 150-6, 2014 Jan.
Article in English | MEDLINE | ID: mdl-23937117

ABSTRACT

BACKGROUND: There is only retrospective evidence for the efficacy of narrowband ultraviolet B (NB-UVB) in children with eczema. OBJECTIVES: To measure the difference in means for objective scores [Six Area Six Sign Atopic Dermatitis score (SASSAD), percentage surface area] and quality-of-life scores, between patients treated with NB-UVB and unexposed cohorts at the end of treatment, and 3 and 6 months post-treatment. METHODS: Twenty-nine children aged 3-16 years for whom NB-UVB was indicated, were scored prospectively using SASSAD and percentage surface area involvement at baseline, at 12 weeks (end of treatment) and 3 and 6 months post-NB-UVB. Their scores were compared with those of unexposed children (n = 26) for whom NB-UVB phototherapy was indicated and offered, but who chose not to undertake treatment. RESULTS: There was a 61% reduction in mean SASSAD score in the NB-UVB cohort compared with an increase of 6% in the unexposed cohort. Mean SASSAD score for the NB-UVB cohort at the end of treatment was 11.6 vs. 24.8 for the unexposed; difference in means -13.2 [95% confidence interval (CI) -18.7 to -7.7, P < 0.0001]. Mean surface area involvement at the end of treatment was 11% for the NB-UVB cohort vs. 36% for the unexposed cohort; difference in means -25% (95% CI -34% to -16%, P < 0.0001). Subjective and quality-of-life scores showed significant difference between cohorts at the end of treatment (P < 0.05). Objective scores remained significantly lower than in the unexposed cohort 3 and 6 months after treatment. CONCLUSION: NB-UVB is clinically effective and improves quality of life in children with moderate-to-severe eczema. The effect is maintained for 6 months after treatment.


Subject(s)
Eczema/radiotherapy , Ultraviolet Therapy/methods , Adolescent , Child , Child, Preschool , Female , Humans , Male , Prospective Studies , Remission Induction/methods , Treatment Outcome
19.
J Phys Condens Matter ; 25(42): 425701, 2013 Oct 23.
Article in English | MEDLINE | ID: mdl-24065357

ABSTRACT

We report neutron inelastic scattering measurements on polycrystalline LaFePO and Sr2ScO3FeP, two members of the iron phosphide families of superconductors. No evidence is found for any magnetic fluctuations in the spectrum of either material in the energy and wavevector ranges probed. Special attention is paid to the wavevector at which spin-density-wave-like fluctuations are seen in other iron-based superconductors. We estimate that the magnetic signal, if present, is at least a factor of four (Sr2ScO3FeP) or seven (LaFePO) smaller than in the related iron arsenide and chalcogenide superconductors. These results suggest that magnetic fluctuations are not as influential on the electronic properties of the iron phosphide systems as they are in other iron-based superconductors.

20.
Clin Exp Dermatol ; 38(5): 517-9, 2013 Jul.
Article in English | MEDLINE | ID: mdl-23672283

ABSTRACT

Although catastrophic vascular complications in vascular Ehlers-Danlos Syndrome (EDS) are well recognized, other complications such as flexion contractures and tendon nodules are rarely reported and poorly characterized. We report a young man with vascular EDS, who developed flexion contractures and tendon nodules, causing considerable disability. Limited management strategies are available for these complications, which have continued to prove a challenge to management.


Subject(s)
Contracture/etiology , Ehlers-Danlos Syndrome/complications , Foot Deformities, Acquired/etiology , Hand Deformities, Acquired/etiology , Adolescent , Humans , Male
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