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1.
Phys Rev Lett ; 130(22): 222501, 2023 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-37327448

RESUMO

The ß-delayed proton decay of ^{13}O has previously been studied, but the direct observation of ß-delayed 3αp decay has not been reported. Rare 3αp events from the decay of excited states in ^{13}N^{⋆} provide a sensitive probe of cluster configurations in ^{13}N. To measure the low-energy products following ß-delayed 3αp decay, the Texas Active Target (TexAT) time projection chamber was employed using the one-at-a-time ß-delayed charged-particle spectroscopy technique at the Cyclotron Institute, Texas A&M University. A total of 1.9×10^{5} ^{13}O implantations were made inside the TexAT time projection chamber. A total of 149 3αp events were observed, yielding a ß-delayed 3αp branching ratio of 0.078(6)%. Four previously unknown α-decaying excited states were observed in ^{13}N at 11.3, 12.4, 13.1, and 13.7 MeV decaying via the 3α+p channel.


Assuntos
Prótons , Humanos , Análise Espectral
2.
Nat Commun ; 13(1): 2151, 2022 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-35444209

RESUMO

The neutron inelastic scattering of carbon-12, populating the Hoyle state, is a reaction of interest for the triple-alpha process. The inverse process (neutron upscattering) can enhance the Hoyle state's decay rate to the bound states of 12C, effectively increasing the overall triple-alpha reaction rate. The cross section of this reaction is impossible to measure experimentally but has been determined here at astrophysically-relevant energies using detailed balance. Using a highly-collimated monoenergetic beam, here we measure neutrons incident on the Texas Active Target Time Projection Chamber (TexAT TPC) filled with CO2 gas, we measure the 3α-particles (arising from the decay of the Hoyle state following inelastic scattering) and a cross section is extracted. Here we show the neutron-upscattering enhancement is observed to be much smaller than previously expected. The importance of the neutron-upscattering enhancement may therefore not be significant aside from in very particular astrophysical sites (e.g. neutron star mergers).

3.
Phys Rev E ; 104(1): L013201, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34412205

RESUMO

A series of thin glass-shell shock-driven DT gas-filled capsule implosions was conducted at the OMEGA laser facility. These experiments generate conditions relevant to the central plasma during the shock-convergence phase of ablatively driven inertial confinement fusion (ICF) implosions. The spectral temperatures inferred from the DTn and DDn spectra are most consistent with a two-ion-temperature plasma, where the initial apparent temperature ratio, T_{T}/T_{D}, is 1.5. This is an experimental confirmation of the long-standing conjecture that plasma shocks couple energy directly proportional to the species mass in multi-ion plasmas. The apparent temperature ratio trend with equilibration time matches expected thermal equilibration described by hydrodynamic theory. This indicates that deuterium and tritium ions have different energy distributions for the time period surrounding shock convergence in ignition-relevant ICF implosions.

4.
Rev Sci Instrum ; 92(2): 023503, 2021 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-33648107

RESUMO

Millimeter-sized CD foils fielded close (order mm) to inertial confinement fusion (ICF) implosions have been proposed as a game-changer for improving energy resolution and allowing time-resolution in neutron spectrum measurements using the magnetic recoil technique. This paper presents results from initial experiments testing this concept for direct drive ICF at the OMEGA Laser Facility. While the foils are shown to produce reasonable signals, inferred spectral broadening is seen to be high (∼5 keV) and signal levels are low (by ∼20%) compared to expectation. Before this type of foil is used for precision experiments, the foil mount must be improved, oxygen uptake in the foils must be better characterized, and impact of uncontrolled foil motion prior to detection must be investigated.

5.
Phys Rev Lett ; 122(3): 035001, 2019 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-30735406

RESUMO

Fuel-ion species dynamics in hydrodynamiclike shock-driven DT^{3}He-filled inertial confinement fusion implosion is quantitatively assessed for the first time using simultaneously measured D^{3}He and DT reaction histories. These reaction histories are measured with the particle x-ray temporal diagnostic, which captures the relative timing between different nuclear burns with unprecedented precision (∼10 ps). The observed 50±10 ps earlier D^{3}He reaction history timing (relative to DT) cannot be explained by average-ion hydrodynamic simulations and is attributed to fuel-ion species separation between the D, T, and ^{3}He ions during shock convergence and rebound. At the onset of the shock burn, inferred ^{3}He/T fuel ratio in the burn region using the measured reaction histories is much higher as compared to the initial gas-filled ratio. As T and ^{3}He have the same mass but different charge, these results indicate that the charge-to-mass ratio plays an important role in driving fuel-ion species separation during strong shock propagation even for these hydrodynamiclike plasmas.

6.
Rev Sci Instrum ; 89(11): 113508, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30501287

RESUMO

The next-generation Magnetic Recoil Spectrometer, called MRSt, will provide time-resolved measurements of the deuterium-tritium-neutron spectrum from inertial confinement fusion implosions at the National Ignition Facility. These measurements will provide critical information about the time evolution of the fuel assembly, hot-spot formation, and nuclear burn. The absolute neutron spectrum in the energy range of 12-16 MeV will be measured with high accuracy (∼5%), unprecedented energy resolution (∼100 keV) and, for the first time ever, time resolution (∼20 ps). Crucial to the design of the system is a CD conversion foil for the production of recoil deuterons positioned as close to the implosion as possible. The foil-on-hohlraum technique has been demonstrated by placing a 1-mm-diameter, 40-µm-thick CD foil on the hohlraum diagnostic band along the line-of-sight of the current time-integrated MRS system, which measured the recoil deuterons. In addition to providing validation of the foil-on-hohlraum technique for the MRSt design, substantial improvement of the MRS energy resolution has been demonstrated.

7.
Rev Sci Instrum ; 89(10): 10I129, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30399924

RESUMO

The Magnetic Recoil neutron Spectrometer (MRS) at the OMEGA laser facility has been routinely used to measure deuterium-tritium (DT) yield and areal density in cryogenically layered implosions since 2008. Recently, operation of the OMEGA MRS in higher-resolution mode with a new smaller, thinner (4 cm2, 57 µm thick) CD2 conversion foil has also enabled inference of the apparent DT ion temperature (T ion) from MRS data. MRS-inferred T ion compares well with T ion as measured using neutron time-of-flight spectrometers, which is important as it demonstrates good understanding of the very different systematics associated with the two independent measurements. The MRS resolution in this configuration, ΔE MRS = 0.91 MeV FWHM, is still higher than that required for a high-precision T ion measurement. We show how fielding a smaller foil closer to the target chamber center and redesigning the MRS detector array could bring the resolution to ΔE MRS = 0.45 MeV, reducing the systematic T ion uncertainty by more than a factor of 4.

8.
Aliment Pharmacol Ther ; 48(3): 347-357, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29920726

RESUMO

BACKGROUND: Fibrotic stricture is a common complication of Crohn's disease (CD) affecting approximately half of all patients. No specific anti-fibrotic therapies are available; however, several therapies are currently under evaluation. Drug development for the indication of stricturing CD is hampered by a lack of standardised definitions, diagnostic modalities, clinical trial eligibility criteria, endpoints and treatment targets in stricturing CD. AIM: To standardise definitions, diagnosis and treatment targets for anti-fibrotic stricture therapies in Chron's disease. METHODS: An interdisciplinary expert panel consisting of 15 gastroenterologists and radiologists was assembled. Using modified RAND/University of California Los Angeles appropriateness methodology, 109 candidate items derived from systematic review and expert opinion focusing on small intestinal strictures were anonymously rated as inappropriate, uncertain or appropriate. Survey results were discussed as a group before a second and third round of voting. RESULTS: Fibrotic strictures are defined by the combination of luminal narrowing, wall thickening and pre-stenotic dilation. Definitions of anastomotic (at site of prior intestinal resection with anastomosis) and naïve small bowel strictures were similar; however, there was uncertainty regarding wall thickness in anastomotic strictures. Magnetic resonance imaging is considered the optimal technique to define fibrotic strictures and assess response to therapy. Symptomatic strictures are defined by abdominal distension, cramping, dietary restrictions, nausea, vomiting, abdominal pain and post-prandial abdominal pain. Need for intervention (endoscopic balloon dilation or surgery) within 24-48 weeks is considered the appropriate endpoint in pharmacological trials. CONCLUSIONS: Consensus criteria for diagnosis and response to therapy in stricturing Crohn's disease should inform both clinical practice and trial design.


Assuntos
Consenso , Doença de Crohn/terapia , Prova Pericial , Obstrução Intestinal/diagnóstico , Obstrução Intestinal/terapia , Guias de Prática Clínica como Assunto/normas , Cateterismo/métodos , Cateterismo/normas , Ensaios Clínicos como Assunto/normas , Ensaios Clínicos como Assunto/estatística & dados numéricos , Colo/patologia , Colo/cirurgia , Constrição Patológica/diagnóstico , Constrição Patológica/etiologia , Constrição Patológica/terapia , Doença de Crohn/complicações , Doença de Crohn/diagnóstico , Dilatação/métodos , Dilatação/normas , Endoscopia , Fibrose/diagnóstico , Fibrose/etiologia , Fibrose/terapia , Humanos , Obstrução Intestinal/classificação , Obstrução Intestinal/etiologia , Intestino Delgado/patologia , Intestino Delgado/cirurgia , Padrões de Referência
9.
Aliment Pharmacol Ther ; 48(2): 114-126, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29851091

RESUMO

BACKGROUND: Aminosalicylates are the most frequently prescribed drugs for patients with Crohn's disease (CD), yet evidence to support their efficacy as induction or maintenance therapy is controversial. AIMS: To quantify aminosalicylate use in CD clinical trials, identify factors associated with use and estimate direct annual treatment costs of therapy. METHODS: MEDLINE, Embase and CENTRAL were searched to April 2017 for placebo-controlled trials in adults with CD treated with corticosteroids, immunosuppressants or biologics. The proportion of patients co-prescribed aminosalicylates in placebo arms was pooled using a random-effects model. Meta-regression was used to identify factors associated with aminosalicylate use. Annual treatment costs were estimated using the 2016 Ontario Drug Benefit Program. RESULTS: Forty-two induction and 10 maintenance trials were included. The pooled proportion of patients co-prescribed aminosalicylates was 44% [95% CI: 39%-49%] in induction trials and 49% [95% CI: 35%-64%] in maintenance trials. There was substantial to considerable heterogeneity (I2  = 86.0%, 91.8% for induction and maintenance trials, respectively). In multivariable meta-regression, aminosalicylate use has decreased over time in induction trials (OR 0.50 [95% CI: 0.34-0.74] per 10-year increment). While a decline has been seen over time, 35% of CD patients were still using aminosalicylates in contemporary trials from the last 5 years. The estimated annual cost for the lowest price mesalazine (mesalamine) formulation is approximately $32 million for the Canadian CD population. CONCLUSIONS: Over one-third of CD patients entering clinical trials are still co-prescribed aminosalicylates. A definitive trial is needed to inform the conventional practice of using aminosalicylates as CD maintenance therapy.


Assuntos
Doença de Crohn/tratamento farmacológico , Doença de Crohn/economia , Doença de Crohn/epidemiologia , Mesalamina/economia , Mesalamina/uso terapêutico , Corticosteroides/administração & dosagem , Corticosteroides/efeitos adversos , Corticosteroides/economia , Adulto , Produtos Biológicos/administração & dosagem , Produtos Biológicos/efeitos adversos , Produtos Biológicos/economia , Custos de Medicamentos , Quimioterapia Combinada/economia , Quimioterapia Combinada/estatística & dados numéricos , Humanos , Imunossupressores/administração & dosagem , Imunossupressores/efeitos adversos , Imunossupressores/economia , Ontário/epidemiologia , Padrões de Prática Médica/economia , Padrões de Prática Médica/estatística & dados numéricos , Prevalência , Indução de Remissão , Fatores de Risco
10.
Phys Rev C ; 972018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29732443

RESUMO

The 12C(n, 2n)11C cross section was measured from just below threshold to 26.5 MeV using the Pelletron accelerator at Ohio University. Monoenergetic neutrons, produced via the 3H(d,n)4He reaction, were allowed to strike targets of polyethylene and graphite. Activation of both targets was measured by counting positron annihilations resulting from the ß+ decay of 11C. Annihilation gamma rays were detected, both in coincidence and singly, using back-to-back NaI detectors. The incident neutron flux was determined indirectly via 1H(n,p) protons elastically scattered from the polyethylene target. Previous measurements fall into upper and lower bands; the results of the present measurement are consistent with the upper band.

11.
Diagn Microbiol Infect Dis ; 91(4): 319-323, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29636246

RESUMO

New on-demand multiplex molecular respiratory viral diagnostics offer superior performance although can be expensive and some platforms cannot process multiple specimens simultaneously. We performed a retrospective study reviewing results of patients tested for respiratory viruses following introduction of a two-stage testing algorithm incorporating an initial screen with Sofia® immunoassay then secondary Biofire Filmarray®, and compared to a period when only Filmarray® was used. Of 2976 testing episodes, 1814 underwent initial Sofia® then follow-up FilmArray®. A diagnosis of influenza was made by Sofia® in 282 patients, and by FilmArray® in an additional 163 (median time to result 1.12hours versus 3.46hours, P<0.001). Significantly more patients received their diagnosis within 90minutes in winter despite testing more samples (11.1% versus 3.4%, P<0.001), and approximately $36,000 was saved. An algorithmic approach to respiratory viral diagnosis can combine the advantages of accuracy and speed and be cost saving.


Assuntos
Algoritmos , Testes Diagnósticos de Rotina/métodos , Imunoensaio , Influenza Humana/diagnóstico , Influenza Humana/virologia , Reação em Cadeia da Polimerase Multiplex , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Testes Diagnósticos de Rotina/economia , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Programas de Rastreamento/economia , Pessoa de Meia-Idade , Infecções Respiratórias/diagnóstico , Infecções Respiratórias/virologia , Estudos Retrospectivos , Sensibilidade e Especificidade , Adulto Jovem
12.
Aliment Pharmacol Ther ; 47(12): 1578-1596, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29696670

RESUMO

BACKGROUND: Regulatory requirements for claims of mucosal healing in ulcerative colitis (UC) will require demonstration of both endoscopic and histologic healing. Quantifying these rates is essential for future drug development. AIMS: To meta-analyse endoscopic and histologic placebo response and remission rates in UC randomised controlled trials (RCTs) and identify factors influencing these rates. METHODS: MEDLINE, EMBASE and the Cochrane Library were searched from inception to March 2017 for placebo-controlled trials of pharmacological interventions for UC. Endoscopic and histologic placebo rates were pooled by random effects. Mixed effects univariable and multivariable meta-regression was used to evaluate the influence of patient, intervention and trial-related study-level covariates on these rates. RESULTS: Fifty-six induction (placebo n = 4171) and 8 maintenance trials (placebo n = 1011) were included. Pooled placebo endoscopic remission and response rates for induction trials were 23% [95 confidence interval (CI) 19-28%] and 35% [95% CI 27-42%] respectively, and 20% [95% CI 16-24%] for maintenance of remission. The pooled histologic placebo remission rate was 14% [95% CI 8-22%] for induction trials. High heterogeneity was observed for all outcomes (I2 56.2%-88.3%). On multivariable meta-regression, central endoscopy reading was associated with significantly lower endoscopic placebo remission rates (16% vs 25%; OR = 0.52, [95% CI 0.29-0.92], P = 0.03). On univariable meta-regression, higher histologic placebo remission was associated with concomitant corticosteroids (OR = 1.17 [95% CI 1.08-1.26], P < 0.0001, per 10% increase in corticosteroid use). CONCLUSIONS: Placebo endoscopic and histologic rates range from 14% to 35% in UC RCTs but are highly heterogeneous. Outcome standardisation may reduce heterogeneity and is needed in this field.


Assuntos
Colite Ulcerativa/tratamento farmacológico , Endoscopia/métodos , Humanos , Ensaios Clínicos Controlados Aleatórios como Assunto , Indução de Remissão
13.
Aliment Pharmacol Ther ; 47(7): 940-950, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29460418

RESUMO

BACKGROUND: The validity of the eosinophilic oesophagitis (EoE) histologic scoring system (EoEHSS) has been demonstrated, but only preliminary reliability data exist. AIM: Formally assess the reliability of the EoEHSS and additional histologic features. METHODS: Four expert gastrointestinal pathologists independently reviewed slides from adult patients with EoE (N = 45) twice, in random order, using standardised training materials and scoring conventions for the EoEHSS and additional histologic features agreed upon during a modified Delphi process. Intra- and inter-rater reliability for scoring the EoEHSS, a visual analogue scale (VAS) of overall histopathologic disease severity, and additional histologic features were assessed using intra-class correlation coefficients (ICCs). RESULTS: Almost perfect intra-rater reliability was observed for the composite EoEHSS scores and the VAS. Inter-rater reliability was also almost perfect for the composite EoEHSS scores and substantial for the VAS. Of the EoEHSS items, eosinophilic inflammation was associated with the highest ICC estimates and consistent with almost perfect intra- and inter-rater reliability. With the exception of dyskeratotic epithelial cells and surface epithelial alteration, ICC estimates for the remaining EoEHSS items were above the benchmarks for substantial intra-rater, and moderate inter-rater reliability. Estimation of peak eosinophil count and number of lamina propria eosinophils were associated with the highest ICC estimates among the exploratory items. CONCLUSION: The composite EoEHSS and most component items are associated with substantial reliability when assessed by central pathologists. Future studies should assess responsiveness of the score to change after a therapeutic intervention to facilitate its use in clinical trials.


Assuntos
Esofagite Eosinofílica/diagnóstico , Técnicas Histológicas , Adulto , Esofagite Eosinofílica/patologia , Eosinófilos/patologia , Feminino , Técnicas Histológicas/normas , Humanos , Contagem de Leucócitos , Masculino , Pessoa de Meia-Idade , Variações Dependentes do Observador , Valor Preditivo dos Testes , Reprodutibilidade dos Testes , Estudos Retrospectivos , Escala Visual Analógica
14.
Aliment Pharmacol Ther ; 46(3): 292-302, 2017 08.
Artigo em Inglês | MEDLINE | ID: mdl-28568974

RESUMO

BACKGROUND: High concentration mesalazine formulations are more convenient than conventional low concentration formulations for the treatment of ulcerative colitis (UC). AIM: To compare the efficacy and safety of 1600 mg and 400 mg tablet mesalazine formulations. METHODS: Patients with mild-to-moderate active UC (Mayo Clinic Score >5; N=817) were randomised to 3.2 g of oral mesalazine, administered as two 1600 mg tablets once, or four 400 mg tablets twice daily. We hypothesised that treatment with the 1600 mg tablet was non-inferior (within a 10% margin) to the 400 mg tablet for induction of clinical and endoscopic remission at week 8. Open-label treatment with the 1600 mg tablet continued for 26-30 weeks based on induction response. Predictors of treatment response were also explored. RESULTS: At week 8, remission occurred in 22.4% and 24.6% of patients receiving the 1600 mg and 400 mg tablets, respectively (absolute difference -2.2%, 95% CI: -8.1% to 3.8%, non-inferiority P=.005). Endoscopic and histopathologic disease activity, leucocyte concentration and age were significantly associated with clinical remission (P=.022, .042, .014 and .023, respectively). At week 38, 43.9% (296/675) of patients who continued treatment with the 1600 mg formulation were in remission, including 70.3% (142/202) of patients who received a reduced dose of mesalazine (1.6 g/d). The overall incidence of serious adverse events was low. CONCLUSIONS: Induction therapy with 3.2 mg mesalazine using two 1600 mg tablets once-daily was statistically and clinically non-inferior to a twice-daily regimen using four 400 mg tablets (NCT01903252).


Assuntos
Anti-Inflamatórios não Esteroides/administração & dosagem , Colite Ulcerativa/tratamento farmacológico , Mesalamina/administração & dosagem , Administração Oral , Adolescente , Adulto , Idoso , Anti-Inflamatórios não Esteroides/efeitos adversos , Química Farmacêutica , Relação Dose-Resposta a Droga , Método Duplo-Cego , Feminino , Humanos , Masculino , Mesalamina/uso terapêutico , Pessoa de Meia-Idade , Indução de Remissão , Comprimidos
15.
J Mass Spectrom ; 52(5): 319-341, 2017 05.
Artigo em Inglês | MEDLINE | ID: mdl-28418607

RESUMO

Proteins can provide insights into biological processes at the functional level, so they are very promising biomarker candidates. The quantification of proteins in biological samples has been routinely used for the diagnosis of diseases and monitoring the treatment. Although large-scale protein quantification in complex samples is still a challenging task, a great amount of effort has been made to advance the technologies that enable quantitative proteomics. Seven years ago, in 2009, we wrote an article about the current trends in quantitative proteomics. In writing this current paper, we realized that, today, we have an even wider selection of potential tools for quantitative proteomics. These tools include new derivatization reagents, novel sampling formats, new types of analyzers and scanning techniques, and recently developed software to assist in assay development and data analysis. In this review article, we will discuss these innovative methods, and their current and potential applications in proteomics. Copyright © 2017 John Wiley & Sons, Ltd.


Assuntos
Proteoma/análise , Proteômica/métodos , Animais , Biomarcadores/análise , Teste em Amostras de Sangue Seco , Humanos , Espectrometria de Massas/instrumentação , Espectrometria de Massas/métodos , Espectrometria de Massas/normas , Proteômica/normas , Proteômica/tendências , Padrões de Referência , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
16.
Aliment Pharmacol Ther ; 45(8): 1021-1042, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-28164348

RESUMO

BACKGROUND: Minimising placebo response is essential for drug development. AIM: To conduct a meta-analysis to determine placebo response and remission rates in trials and identify the factors affecting these rates. METHODS: MEDLINE, EMBASE and CENTRAL were searched from inception to April 2014 for placebo-controlled trials of pharmacological interventions for Crohn's disease. Placebo response and remission rates for induction and maintenance trials were pooled by random-effects and mixed-effects meta-regression models to evaluate effects of study-level characteristics on these rates. RESULTS: In 100 studies containing 67 induction and 40 maintenance phases and 7638 participants, pooled placebo remission and response rates for induction trials were 18% [95% confidence interval (CI) 16-21%] and 28% (95% CI 24-32%), respectively. Corresponding values for maintenance trials were 32% (95% CI 25-39%) and 26% (95% CI 19-35%), respectively. For remission, trials enrolling patients with more severe disease activity, longer disease duration and more study centres were associated with lower placebo rates, whereas more study visits and longer study duration was associated with higher placebo rates. For response, findings were opposite such that trials enrolling patients with less severe disease activity and longer study duration were associated with lower placebo rates. Placebo rates varied by drug class and route of administration, with the highest placebo response rates observed for biologics. CONCLUSIONS: Placebo rates vary according to whether trials are designed for induction or maintenance and the factors influencing them differ for the endpoints of remission and response. These findings have important implications for clinical trial design in Crohn's disease.


Assuntos
Ensaios Clínicos como Assunto/métodos , Ensaios Clínicos como Assunto/estatística & dados numéricos , Doença de Crohn/tratamento farmacológico , Doença de Crohn/epidemiologia , Quimioterapia de Indução/estatística & dados numéricos , Quimioterapia de Manutenção/estatística & dados numéricos , Humanos , Placebos , Indução de Remissão , Projetos de Pesquisa
17.
Am J Transplant ; 16(11): 3139-3149, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-27265023

RESUMO

B cells play a central role in antibody-mediated rejection and certain autoimmune diseases. However, B cell-targeted therapy such as anti-CD20 B cell-depleting antibody (aCD20) has yielded mixed results in improving outcomes. In this study, we investigated whether an accelerated B cell reconstitution leading to aCD20 depletion resistance could account for these discrepancies. Using a transplantation model, we found that antigen-independent inflammation, likely through toll-like receptor (TLR) signaling, was sufficient to mitigate B cell depletion. Secondary lymphoid organs had a quicker recovery of B cells when compared to peripheral blood. Inflammation altered the pharmacokinetics (PK) and pharmacodynamics (PD) of aCD20 therapy by shortening drug half-life and accelerating the reconstitution of the peripheral B cell pool by bone marrow-derived B cell precursors. IVIG (intravenous immunoglobulin) coadministration also shortened aCD20 drug half-life and led to accelerated B cell recovery. Repeated aCD20 dosing restored B cell depletion and delayed allograft rejection, especially B cell-dependent, antibody-independent allograft rejection. These data demonstrate the importance of further clinical studies of the PK/PD of monoclonal antibody treatment in inflammatory conditions. The data also highlight the disconnect between B cell depletion on peripheral blood compared to secondary lymphoid organs, the deleterious effect of IVIG when given with aCD20 and the relevance of redosing of aCD20 for effective B cell depletion in alloimmunity.


Assuntos
Antígenos CD20/imunologia , Linfócitos B/imunologia , Rejeição de Enxerto/prevenção & controle , Sobrevivência de Enxerto/imunologia , Inflamação/imunologia , Depleção Linfocítica , Rituximab/farmacologia , Animais , Feminino , Rejeição de Enxerto/etiologia , Transplante de Coração/efeitos adversos , Imunoglobulinas Intravenosas/administração & dosagem , Fatores Imunológicos/farmacologia , Inflamação/patologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL
18.
Br J Cancer ; 111(11): 2076-81, 2014 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-25247322

RESUMO

BACKGROUND: Colorectal cancers (CRCs) detected through the NHS Bowel Cancer Screening Programme (BCSP) have been shown to have a more favourable outcome compared to non-screen-detected cancers. The aim was to identify whether this was solely due to the earlier stage shift of these cancers, or whether other factors were involved. METHODS: A combination of a regional CRC registry (Northern Colorectal Cancer Audit Group) and the BCSP database were used to identify screen-detected and interval cancers (diagnosed after a negative faecal occult blood test, before the next screening round), diagnosed between April 2007 and March 2010, within the North East of England. For each Dukes' stage, patient demographics, tumour characteristics, and survival rates were compared between these two groups. RESULTS: Overall, 322 screen-detected cancers were compared against 192 interval cancers. Screen-detected Dukes' C and D CRCs had a superior survival rate compared with interval cancers (P=0.014 and P=0.04, respectively). Cox proportional hazards regression showed that Dukes' stage, tumour location, and diagnostic group (HR 0.45, 95% CI 0.29-0.69, P<0.001 for screen-detected CRCs) were all found to have a significant impact on the survival of patients. CONCLUSIONS: The improved survival of screen-detected over interval cancers for stages C and D suggest that there may be a biological difference in the cancers in each group. Although lead-time bias may have a role, this may be related to a tumour's propensity to bleed and therefore may reflect detection through current screening tests.


Assuntos
Neoplasias Colorretais/diagnóstico , Detecção Precoce de Câncer , Idoso , Neoplasias Colorretais/mortalidade , Neoplasias Colorretais/patologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Modelos de Riscos Proporcionais
19.
Pregnancy Hypertens ; 2(3): 258, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-26105353

RESUMO

INTRODUCTION: In women experiencing their first pregnancy the assessment of risk of developing a hypertensive disorder of pregnancy (HDP) including preeclampsia is imprecise. Identification of women at higher than normal risk of developing preeclampsia may improve pregnancy management and lead to better outcomes. Previous studies, mostly retrospective, have indicated a possible link between cardiovascular history and risk of preeclampsia. OBJECTIVES: To evaluate the self-reported family history of cardiovascular disease and risk (CVD/R) during an antenatal interview as a means of screening for risk of developing preeclampsia or other HDP. METHODS: Nulliparous women were recruited prospectively in early pregnancy before diagnosis of any HDP. Women reported on their maternal characteristics and the history of cardiovascular health in themselves, their parents and siblings and the father of the baby and his parents and siblings. Cardiovascular health was assessed as cardiovascular risk (high blood pressure, high cholesterol and diabetes) and cardiovascular disease (heart attack, stroke, angina and any major vascular surgery). Pregnancy outcomes were recorded after delivery, the diagnoses of gestational hypertension, preeclampsia and superimposed preeclampsia being assigned according to the criteria defined by SOMANZ, 2008. A nominal logistic regression analysis was used to evaluate the effects of family history on risk of developing HDP while adjusting for clinical risk factors known at the time of recruitment. RESULTS: Nine hundred and ninety-seven women completed the study. Median gestational age at recruitment was 31.3weeks (Interquartile range [IQR] 24.4-35.9, range 5.6-39.1). Median age was 27.0years (IQR 23.0-32.0, range 16.0-45.0), median BMI was 28.6 (IQR 24.8-36.4, range 16.7-64.4) and 76.4% of the women did not smoke during the pregnancy. Preeclampsia was diagnosed in 12.6% of the women (103/997 preeclampsia, 23/997 superimposed) and 6.2% developed gestational hypertension (62/997). CVD/R was reported by 22.3% of mothers (including 1.7% of CVD alone) and in 9.3% of the partners (including 1.7% of CVD alone). Women reported CVD/R in 39.1% of their mothers (including 6.5% CVD alone) and in 42.2% (including 13.3% CVD alone) of their fathers. Women reported CVD/R in 30.3% (including 6.1% CVD alone) of the partners' mothers and in 38.9% (including 15.0% CVD alone) of the partners' fathers. Women who knew of CVD/R in their fathers had increased risk of preeclampsia (16.2% vs. 10.1%; Odds Ratio [OR]=.66 95% Confidence Interval [CI] 1.16-2.36, p=.005) that remained elevated after adjustments for maternal age, BMI, smoking in pregnancy and maternal CVD/R. No similar increase in risk of gestational hypertension was evident (7.4% vs. 5.4%; OR=1.31 95% CI0.81-2.10,p=0.272). CVD/R reported for any other family member did not significantly alter the woman's risk of developing preeclampsia or any other HDP. CONCLUSION: The presence of a history of CVD/R in the father of the pregnant woman indicated an increased risk of developing preeclampsia. The possibility of a similar association between CVD/R in other family members and HDP may exist however women in their first pregnancy may not have sufficient knowledge of family history. This lack of comprehensive information may limit the potential value of family history in determining the risk of preeclampsia and other hypertensive disorders in pregnancy.

20.
Free Radic Biol Med ; 38(6): 698-710, 2005 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-15721980

RESUMO

Oxidation products of lipids, proteins, and DNA in the blood, plasma, and urine of rats were measured as part of a comprehensive, multilaboratory validation study searching for noninvasive biomarkers of oxidative stress. This article is the second report of the nationwide Biomarkers of Oxidative Stress Study using acute CCl4 poisoning as a rodent model for oxidative stress. The time-dependent (2, 7, and 16 h) and dose-dependent (120 and 1200 mg/kg i.p.) effects of CCl4 on concentrations of lipid hydroperoxides, TBARS, malondialdehyde (MDA), isoprostanes, protein carbonyls, methionine sulfoxidation, tyrosine products, 8-hydroxy-2'-deoxyguanosine (8-OHdG), leukocyte DNA-MDA adducts, and DNA-strand breaks were investigated to determine whether the oxidative effects of CCl4 would result in increased generation of these oxidation products. Plasma concentrations of MDA and isoprostanes (both measured by GC-MS) and urinary concentrations of isoprostanes (measured with an immunoassay or LC/MS/MS) were increased in both low-dose and high-dose CCl4-treated rats at more than one time point. The other urinary markers (MDA and 8-OHdG) showed significant elevations with treatment under three of the four conditions tested. It is concluded that measurements of MDA and isoprostanes in plasma and urine as well as 8-OHdG in urine are potential candidates for general biomarkers of oxidative stress. All other products were not changed by CCl4 or showed fewer significant effects.


Assuntos
Intoxicação por Tetracloreto de Carbono/metabolismo , Tetracloreto de Carbono/toxicidade , DNA/metabolismo , Desoxiguanosina/análogos & derivados , Metabolismo dos Lipídeos , Estresse Oxidativo , 8-Hidroxi-2'-Desoxiguanosina , Animais , Ensaio Cometa , Dano ao DNA , Desoxiguanosina/farmacologia , Radicais Livres , Cromatografia Gasosa-Espectrometria de Massas , Peróxido de Hidrogênio/metabolismo , Imunoensaio , Immunoblotting , Fígado/metabolismo , Masculino , Malondialdeído/farmacologia , Metionina/metabolismo , Oxigênio/metabolismo , Ratos , Ratos Endogâmicos F344 , Espectrofotometria , Substâncias Reativas com Ácido Tiobarbitúrico , Fatores de Tempo , Tirosina/química , Tirosina/metabolismo
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