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1.
Phys Rev Lett ; 132(19): 195001, 2024 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-38804956

RESUMO

Experiments were performed on laser wakefield acceleration in the highly nonlinear regime. With laser powers P<250 TW and using an initial spot size larger than the matched spot size for guiding, we were able to accelerate electrons to energies E_{max}>2.5 GeV, in fields exceeding 500 GV m^{-1}, with more than 80 pC of charge at energies E>1 GeV. Three-dimensional particle-in-cell simulations show that using an oversized spot delays injection, avoiding beam loss as the wakefield undergoes length oscillation. This enables injected electrons to remain in the regions of highest accelerating fields and leads to a doubling of energy gain as compared to results from using half the focal length with the same laser.

2.
Behav Res Methods ; 2024 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-38890263

RESUMO

Impairments of object recognition are core features of neurodegenerative syndromes, in particular posterior cortical atrophy (PCA; the 'visual-variant Alzheimer's disease'). These impairments arise from damage to higher-level cortical visual regions and are often missed or misattributed to common ophthalmological conditions. Consequently, diagnosis can be delayed for years with considerable implications for patients. We report a new test for the rapid measurement of cortical visual loss - the Graded Incomplete Letters Test (GILT). The GILT is an optimised psychophysical variation of a test used to diagnose cortical visual impairment, which measures thresholds for recognising letters under levels of increasing visual degradation (decreasing "completeness") in a similar fashion to ophthalmic tests. The GILT was administered to UK Biobank participants (total n=2,359) and participants with neurodegenerative conditions characterised by initial cortical visual (PCA, n=18) or memory loss (typical Alzheimer's disease, n=9). UK Biobank participants, including both typical adults and those with ophthalmological conditions, were able to recognise letters under low levels of completeness. In contrast, participants with PCA consistently made errors with only modest decreases in completeness. GILT sensitivity to PCA was 83.3% for participants reaching the 80% accuracy cut-off, increasing to 88.9% using alternative cut-offs (60% or 100% accuracy). Specificity values were consistently over 94% when compared to UK Biobank participants without or with documented visual conditions, regardless of accuracy cut-off. These first-release UK Biobank and clinical verification data suggest the GILT has utility in both rapidly detecting visual perceptual losses following posterior cortical damage and differentiating perceptual losses from common eye-related conditions.

3.
Ann Oncol ; 30(7): 1134-1142, 2019 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-30918950

RESUMO

BACKGROUND: Preclinical evidence suggests that MEK inhibition promotes accumulation and survival of intratumoral tumor-specific T cells and can synergize with immune checkpoint inhibition. We investigated the safety and clinical activity of combining a MEK inhibitor, cobimetinib, and a programmed cell death 1 ligand 1 (PD-L1) inhibitor, atezolizumab, in patients with solid tumors. PATIENTS AND METHODS: This phase I/Ib study treated PD-L1/PD-1-naive patients with solid tumors in a dose-escalation stage and then in multiple, indication-specific dose-expansion cohorts. In most patients, cobimetinib was dosed once daily orally for 21 days on, 7 days off. Atezolizumab was dosed at 800 mg intravenously every 2 weeks. The primary objectives were safety and tolerability. Secondary end points included objective response rate, progression-free survival, and overall survival. RESULTS: Between 27 December 2013 and 9 May 2016, 152 patients were enrolled. As of 4 September 2017, 150 patients received ≥1 dose of atezolizumab, including 14 in the dose-escalation cohorts and 136 in the dose-expansion cohorts. Patients had metastatic colorectal cancer (mCRC; n = 84), melanoma (n = 22), non-small-cell lung cancer (NSCLC; n = 28), and other solid tumors (n = 16). The most common all-grade treatment-related adverse events (AEs) were diarrhea (67%), rash (48%), and fatigue (40%), similar to those with single-agent cobimetinib and atezolizumab. One (<1%) treatment-related grade 5 AE occurred (sepsis). Forty-five (30%) and 23 patients (15%) had AEs that led to discontinuation of cobimetinib and atezolizumab, respectively. Confirmed responses were observed in 7 of 84 patients (8%) with mCRC (6 responders were microsatellite low/stable, 1 was microsatellite instable), 9 of 22 patients (41%) with melanoma, and 5 of 28 patients (18%) with NSCLC. Clinical activity was independent of KRAS/BRAF status across diseases. CONCLUSIONS: Atezolizumab plus cobimetinib had manageable safety and clinical activity irrespective of KRAS/BRAF status. Although potential synergistic activity was seen in mCRC, this was not confirmed in a subsequent phase III study. CLINICALTRIALS.GOV IDENTIFIER: NCT01988896 (the investigators in the NCT01988896 study are listed in the supplementary Appendix, available at Annals of Oncology online).


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias/tratamento farmacológico , Adulto , Idoso , Idoso de 80 Anos ou mais , Anticorpos Monoclonais Humanizados/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/farmacocinética , Azetidinas/administração & dosagem , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias/metabolismo , Neoplasias/patologia , Piperidinas/administração & dosagem , Prognóstico , Taxa de Sobrevida , Distribuição Tecidual , Adulto Jovem
4.
Clin Exp Allergy ; 48(5): 493-501, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29412485

RESUMO

Obstructive airways diseases (OAD) represent a huge burden of illness world-wide, and in spite of the development of effective therapies, significant morbidity and mortality related to asthma and COPD still remains. Over the past decade, our understanding of OAD has improved vastly, and novel treatments have evolved. This evolution is the result of successful translational research, which has connected clinical presentations of OAD and underlying disease mechanisms, thereby enabling the development of targeted treatments. The next challenge of translational research will be to position these novel treatments for OAD for optimal clinical use. At the same time, there is great potential in these treatments providing even better insights into disease mechanisms in OAD by studying the effects of blocking individual immunological pathways. To optimize this potential, there is a need to ensure that translational aspects are added to randomized clinical trials, as well as real-world studies, but also to use other trial designs such as platform studies, which allow for simultaneous assessment of different interventions. Furthermore, demonstrating clinical impact, that is research translation, is an increasingly important component of successful translational research. This review outlines concepts of translational research, exemplifying how translational research has moved management of obstructive airways diseases into the next century, with the introduction of targeted, individualized therapy. Furthermore, the review describes how these therapies may be used as research tools to further our understanding of disease mechanisms in OAD, through translational, mechanistic studies. We underline the current need for implementing basic immunological concepts into clinical care in order to optimize the use of novel targeted treatments and to further the clinical understanding of disease mechanisms. Finally, potential barriers to adoption of novel targeted therapies into routine practice and how these may be overcome are described.


Assuntos
Pneumopatias Obstrutivas/terapia , Pesquisa Translacional Biomédica/métodos , Pesquisa Translacional Biomédica/tendências , Humanos
5.
Phys Rev Lett ; 120(7): 074801, 2018 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-29542949

RESUMO

We report on the experimental studies of laser driven ion acceleration from a double-layer target where a near-critical density target with a few-micron thickness is coated in front of a nanometer-thin diamondlike carbon foil. A significant enhancement of proton maximum energies from 12 to ∼30 MeV is observed when a relativistic laser pulse impinges on the double-layer target under linear polarization. We attributed the enhanced acceleration to superponderomotive electrons that were simultaneously measured in the experiments with energies far beyond the free-electron ponderomotive limit. Our interpretation is supported by two-dimensional simulation results.

6.
Brain Behav Immun ; 67: 299-307, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28911981

RESUMO

Experimental stroke leads to microglia activation and progressive neuronal loss at sites of secondary neurodegeneration (SND). These lesions are remote from, but synaptically connected to, primary infarction sites. Previous studies have demonstrated that immune cells are present in sites of infarction in the first hours and days after stroke, and are associated with increased neurodegeneration in peri-infarct regions. However, it is not known whether immune cells are also present in more distal sites where SND occurs. Our study aimed to investigate whether immune cells are present in sites of SND and, if so, how these cell populations compare to those in the peri-infarct zone. Cells were isolated from the thalamus, the main site of SND, and remaining brain tissue 14days post-stroke. Analysis was performed using flow cytometry to quantify microglia, myeloid cell and lymphocyte numbers. We identified a substantial infiltration of immune cells in the ipsilateral (stroked) compared to the contralateral (control) thalamus, with a significant increase in the percentage of CD4+ and CD8+ T cells. This result was further quantified using immunofluorescent labelling of fixed tissue. In the remaining ipsilateral hemisphere tissue, there were significant increases in the frequency of CD4+ and CD8+ T lymphocytes, B lymphocytes, Ly6G+ neutrophils and both Ly6G-Ly6CLO and Ly6G-Ly6CHI monocytes. Our results indicate that infiltrating immune cells persist in ischemic tissue after the acute ischemic phase, and are increased in sites of SND. Importantly, immune cells have been shown to play pivotal roles in both damage and repair processes after stroke. Our findings indicate that immune cells may also be involved in the pathogenesis of SND and further clinical studies are warranted to characterise the nature of inflammatory cell infiltrates in human disease.


Assuntos
Isquemia Encefálica/imunologia , Encéfalo/imunologia , Linfócitos/metabolismo , Microglia/imunologia , Células Mieloides/imunologia , Acidente Vascular Cerebral/imunologia , Animais , Encéfalo/metabolismo , Encéfalo/patologia , Isquemia Encefálica/complicações , Isquemia Encefálica/metabolismo , Isquemia Encefálica/patologia , Masculino , Camundongos Endogâmicos C57BL , Microglia/metabolismo , Células Mieloides/metabolismo , Acidente Vascular Cerebral/complicações , Acidente Vascular Cerebral/metabolismo , Acidente Vascular Cerebral/patologia
7.
Ann Oncol ; 28(3): 528-534, 2017 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-28426123

RESUMO

Background: Cabozantinib, an orally bioavailable inhibitor of tyrosine kinases including MET, AXL, and VEGF receptors, was assessed in patients with hepatocellular carcinoma (HCC) as part of a phase 2 randomized discontinuation trial with nine tumor-type cohorts. Patients and methods: Eligible patients had Child-Pugh A liver function and ≤1 prior systemic anticancer regimen, completed ≥4 weeks before study entry. The cabozantinib starting dose was 100 mg daily. After an initial 12-week cabozantinib treatment period, patients with stable disease (SD) per Response Evaluation Criteria in Solid Tumors (RECIST) version 1.0 were randomized to cabozantinib or placebo. The primary endpoint of the lead-in stage was objective response rate (ORR) at week 12, and the primary endpoint of the randomized stage was progression-free survival (PFS). Results: Among the 41 HCC patients enrolled, the week 12 ORR was 5%, with 2 patients achieving a confirmed partial response (PR). The week 12 disease control rate (PR or SD) was 66% (Asian subgroup: 73%). Of patients with ≥1 post-baseline scan, 78% had tumor regression, with no apparent relationship to prior sorafenib therapy. Alpha-fetoprotein (AFP) response (>50% reduction from baseline) occurred in 9 of the 26 (35%) patients with elevated baseline AFP and ≥1 post-baseline measurement. Twenty-two patients with SD at week 12 were randomized. Median PFS after randomization was 2.5 months with cabozantinib and 1.4 months with placebo, although this difference was not statistically significant. Median PFS and overall survival from Day 1 in all patients were 5.2 and 11.5 months, respectively. The most common grade 3/4 adverse events, regardless of attribution, were diarrhea (20%), hand-foot syndrome (15%), and thrombocytopenia (15%). Dose reductions were utilized in 59% of patients. Conclusions: Cabozantinib has clinical activity in HCC patients, including objective tumor responses, disease stabilization, and reductions in AFP. Adverse events were managed with dose reductions. Trial registration number: NCT00940225.


Assuntos
Anilidas/administração & dosagem , Carcinoma Hepatocelular/tratamento farmacológico , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/patologia , Neoplasias Hepáticas/tratamento farmacológico , Piridinas/administração & dosagem , Adulto , Idoso , Anilidas/efeitos adversos , Carcinoma Hepatocelular/patologia , Intervalo Livre de Doença , Método Duplo-Cego , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/classificação , Feminino , Humanos , Estimativa de Kaplan-Meier , Neoplasias Hepáticas/patologia , Masculino , Pessoa de Meia-Idade , Niacinamida/análogos & derivados , Compostos de Fenilureia , Inibidores de Proteínas Quinases , Piridinas/efeitos adversos , Sorafenibe
8.
Mol Phylogenet Evol ; 110: 60-72, 2017 05.
Artigo em Inglês | MEDLINE | ID: mdl-28274686

RESUMO

Mitogenomic trees for Bivalvia have proved problematic in the past, but several highly divergent lineages were missing from these analyses and increased representation of these groups may yet improve resolution. Here, we add seven new sequences from the Anomalodesmata and one unidentified semelid species (Bryopa lata, Euciroa cf. queenslandica, Laternula elliptica, Laternula truncata, Lyonsia norwegica, Myadora brevis, Tropidomya abbreviata, "Abra" sp.). We show that relationships in a mitogenomic tree for the Class are improved by the addition of seven anomalodesmatans from this highly divergent clade, but are still not completely consistent with relationships recovered in studies of nuclear genes. We suggest that some anomalous relationships (for instance the non-monophyly of Bivalvia) may be partially explained by compositional heterogeneity in the mitogenome and suggest that the addition of more taxa may help resolve both this effect and possible instances of long branch attraction. We also identify several curious features about anomalodesmatan mitogenomes. For example, many protein-coding gene boundaries are poorly defined in marine bivalves, but particularly so in anomalodesmatans, primarily due to non-conserved boundary sequences. The use of transcriptomic and genomic data together enabled better definition of gene boundaries, the identification of possible pseudogenes and suggests that most genes are translated monocistronically, which contrasts with many other studies. We also identified a possible case of gene duplication of ND5 in Myadora brevis (Myochamidae). Mitogenome size in the Anomalodesmata ranges from very small compact molecules, with the smallest for Laternula elliptica (Laternulidae) only 14,622bp, to Bryopa lata (Clavagellidae) which is at least 31,969bp long and may be >40,000bp. Finally, sampled species show a high degree of sequence divergence and variable gene order, although intraspecific variation in Laternula elliptica is very low.


Assuntos
Bivalves/genética , Genoma Mitocondrial , Aminoácidos/genética , Animais , Códon/genética , Duplicação Gênica , Ordem dos Genes , Genômica , Filogenia , Biossíntese de Proteínas , Pseudogenes/genética , RNA de Transferência/genética , Alinhamento de Sequência
9.
Osteoporos Int ; 28(8): 2495-2503, 2017 08.
Artigo em Inglês | MEDLINE | ID: mdl-28540506

RESUMO

The Effectiveness of Discontinuing Bisphosphonates (EDGE) study is a planned pragmatic clinical trial to guide "drug holiday" clinical decision making. This pilot study assessed work flow and feasibility of such a study. While participant recruitment and treatment adherence were suboptimal, administrative procedures were generally feasible and minimally disrupted clinic flow. INTRODUCTION: The comparative effectiveness of continuing or discontinuing long-term alendronate (ALN) on fractures is unknown. A large pragmatic ALN discontinuation study has potential to answer this question. METHODS: We conducted a 6-month pilot study of the planned the EDGE study among current long-term ALN users (women aged ≥65 with ≥3 years of ALN use) to determine study work flow and feasibility including evaluating the administrative aspects of trial conduct (e.g., time to contract, institutional review board (IRB) approval), assessing rates of site and participant recruitment, and evaluating post-randomization outcomes, including adherence, bisphosphonate-associated adverse events, and participant and site satisfaction. We assessed outcomes 1 and 6 months after randomization. RESULTS: Nine sites participated, including seven community-based medical practices and two academic medical centers. On average (SD), contract execution took 3.4 (2.3) months and IRB approval took 13.9 (4.1) days. Sites recruited 27 participants (13 to continue ALN and 14 to discontinue ALN). Over follow-up, 22% of participants did not adhere to their randomization assignment: 30.8% in the continuation arm and 14.3% in the discontinuation arm. No fractures or adverse events were reported. Sites reported no issues regarding work flow, and participants were highly satisfied with the study. CONCLUSIONS: Administrative procedures of the EDGE study were generally feasible, with minimal disruption to clinic flow. In this convenience sample, participant recruitment was suboptimal across most practice sites. Accounting for low treatment arm adherence, a comprehensive recruitment approach will be needed to effectively achieve the scientific goals of the EDGE study.


Assuntos
Conservadores da Densidade Óssea/administração & dosagem , Difosfonatos/administração & dosagem , Osteoporose Pós-Menopausa/tratamento farmacológico , Idoso , Idoso de 80 Anos ou mais , Tomada de Decisão Clínica , Esquema de Medicação , Estudos de Viabilidade , Feminino , Humanos , Adesão à Medicação/estatística & dados numéricos , Fraturas por Osteoporose/prevenção & controle , Projetos Piloto , Suspensão de Tratamento
10.
J R Army Med Corps ; 163(6): 422-424, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28794010

RESUMO

Belize, hosting one of the British Army's overseas training areas, provides access to challenging terrain and austere environments, which allows the delivery of training to soldiers on survival and combat within the jungle environment. A 26-year-old infanteer on exercise in Belize presented with progressive bilateral dry, painful, oedematous hands, secondary to the harsh environmental conditions of the jungle and inadequate drying of his hands resulting in his inability to perform his combat duties. The symptoms completely resolved with drying, emollient application and analgesia. While there are no reported cases of immersion hand, comparisons can be made with the well-reported warm weather immersion foot. This case highlights the importance of force preparation and soldier education for units deploying to the jungle. Simple preventive measures, including adequate 'wet-dry' drills and use of emollients can reduce the prevalence of immersion hand, a preventable condition, which can have a significant impact on the overall combat effectiveness of the unit.


Assuntos
Mãos/fisiopatologia , Militares , Doenças Profissionais/fisiopatologia , Dermatopatias/fisiopatologia , Clima Tropical/efeitos adversos , Adulto , Belize , Humanos , Masculino , Reino Unido
11.
Phys Rev Lett ; 115(6): 064801, 2015 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-26296119

RESUMO

Ultraintense laser pulses with a few-cycle rising edge are ideally suited to accelerating ions from ultrathin foils, and achieving such pulses in practice represents a formidable challenge. We show that such pulses can be obtained using sufficiently strong and well-controlled relativistic nonlinearities in spatially well-defined near-critical-density plasmas. The resulting ultraintense pulses with an extremely steep rising edge give rise to significantly enhanced carbon ion energies consistent with a transition to radiation pressure acceleration.

12.
J Xray Sci Technol ; 23(6): 791-7, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26756414

RESUMO

X-ray backscatter imaging can be used for a wide range of imaging applications, in particular for industrial inspection and portal security. Currently, the application of this imaging technique to the detection of landmines is limited due to the surrounding sand or soil strongly attenuating the 10s to 100s of keV X-rays required for backscatter imaging. Here, we introduce a new approach involving a 140 MeV short-pulse (< 100 fs) electron beam generated by laser wakefield acceleration to probe the sample, which produces Bremsstrahlung X-rays within the sample enabling greater depths to be imaged. A variety of detector and scintillator configurations are examined, with the best time response seen from an absorptive coated BaF2 scintillator with a bandpass filter to remove the slow scintillation emission components. An X-ray backscatter image of an array of different density and atomic number items is demonstrated. The use of a compact laser wakefield accelerator to generate the electron source, combined with the rapid development of more compact, efficient and higher repetition rate high power laser systems will make this system feasible for applications in the field. Content includes material subject to Dstl (c) Crown copyright (2014). Licensed under the terms of the Open Government Licence except where otherwise stated. To view this licence, visit http://www.nationalarchives.gov.uk/doc/open-government-licence/version/3 or write to the Information Policy Team, The National Archives, Kew, London TW9 4DU, or email: psi@ nationalarchives.gsi.gov.uk.


Assuntos
Bombas (Dispositivos Explosivos)/classificação , Lasers , Intensificação de Imagem Radiográfica/instrumentação , Espalhamento de Radiação , Tomografia Computadorizada por Raios X/instrumentação , Guerra , Desenho de Equipamento , Análise de Falha de Equipamento , Imagens de Fantasmas , Raios X
13.
Br J Cancer ; 111(2): 300-8, 2014 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-24960406

RESUMO

BACKGROUND: STX2484 is a novel non-steroidal compound with potent anti-proliferative activity. These studies aimed to identify STX2484's mechanism of action, in vivo efficacy and activity in taxane-resistant breast cancer models. METHODS: Effects of STX2484 and paclitaxel on proliferation, cell cycle and apoptosis were assessed in vitro in drug-resistant (MCF-7(DOX)) and non-resistant cells (MCF-7(WT)). STX2484 efficacy in ßIII tubulin overexpression in MCF-7 cells was also determined. Anti-angiogenic activity was quantified in vitro by a co-culture model and in vivo using a Matrigel plug assay. An MDA-MB-231 xenograft model was used to determine STX2484 efficacy in vivo. RESULTS: STX2484 is a tubulin disruptor, which induces p53 expression, Bcl2 phosphorylation, caspase-3 cleavage, cell cycle arrest and apoptosis. In addition, STX2484 is a potent anti-angiogenic agent in vitro and in vivo. In breast cancer xenografts, STX2484 (20 mg kg(-1) p.o.) suppressed tumour growth by 84% after 35 days of daily dosing, with limited toxicity. In contrast to paclitaxel, STX2484 efficacy was unchanged in two clinically relevant drug-resistant models. CONCLUSIONS: STX2484 is an orally bioavailable microtubule-disrupting agent with in vivo anti-angiogenic activity and excellent in vivo efficacy with no apparent toxicity. Crucially, STX2484 has superior efficacy to paclitaxel in models of clinical drug resistance.


Assuntos
Neoplasias da Mama/tratamento farmacológico , Isoquinolinas/farmacologia , Paclitaxel/farmacologia , Ácidos Sulfônicos/farmacologia , Animais , Antineoplásicos Fitogênicos/farmacologia , Apoptose/efeitos dos fármacos , Neoplasias da Mama/patologia , Ciclo Celular/efeitos dos fármacos , Processos de Crescimento Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Feminino , Humanos , Imuno-Histoquímica , Células MCF-7 , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Nus , Ensaios Antitumorais Modelo de Xenoenxerto
14.
Ann Surg Oncol ; 21(6): 1929-36, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24477709

RESUMO

OBJECTIVE: Pancreaticoduodenectomy is the standard of care for tumors confined to the head of pancreas and can be undertaken with low operative mortality. The procedure has a high morbidity, particularly in older patient populations with preexisting comorbidities. This study evaluated the role of cardiopulmonary exercise testing to predict postoperative morbidity and outcome in high-risk patients undergoing pancreaticoduodenectomy. METHODS: In a prospective cohort of consecutive patients undergoing pancreaticoduodenectomy, those aged over 65 years (or younger with comorbidity) were categorized as high risk and underwent preoperative assessment by cardiopulmonary exercise testing (CPET) according to a predefined protocol. Data were collected on functional status, postoperative complications, and survival. RESULTS: A total of 143 patients underwent preoperative assessment, 50 of whom were deemed to be at low risk for surgery per study protocol. Of 93 high-risk patients, 64 proceeded to surgery after preoperative CPET. Neither anaerobic threshold (AT) nor maximal oxygen consumption ([Formula: see text] O 2 MAX) predicted patient mortality or morbidity. However, ventilatory equivalent of carbon dioxide ([Formula: see text] E/[Formula: see text] CO 2) at AT was a predictive marker of postoperative mortality, with an area under the curve (AUC) of 0.84 (95 % confidence interval [CI] 0.63-1.00, p = 0.020); a threshold of 41 was 75 % sensitive and 95 % specific (positive predictive value 50 %, negative predictive value 98 %). Above this threshold, raised [Formula: see text] E/[Formula: see text] CO 2 predicted poor long-term survival (hazard ratio 2.05, 95 % CI 1.09-3.86, p = 0.026). CONCLUSIONS: CPET is a useful adjunctive test for predicting postoperative outcome in patients being assessed for pancreaticoduodenectomy. Raised CPET-derived [Formula: see text] E/[Formula: see text] CO 2 predicts early postoperative death and poor long-term survival.


Assuntos
Carcinoma/cirurgia , Teste de Esforço , Neoplasias Pancreáticas/cirurgia , Pancreaticoduodenectomia/efeitos adversos , Adulto , Idoso , Idoso de 80 Anos ou mais , Limiar Anaeróbio/fisiologia , Área Sob a Curva , Dióxido de Carbono , Feminino , Mortalidade Hospitalar , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Neoplasias Pancreáticas/mortalidade , Pancreaticoduodenectomia/mortalidade , Valor Preditivo dos Testes , Cuidados Pré-Operatórios , Estudos Prospectivos , Ventilação Pulmonar/fisiologia , Curva ROC , Medição de Risco , Fatores de Tempo
15.
Phys Rev Lett ; 113(23): 235002, 2014 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-25526132

RESUMO

Double-foil targets separated by a low density plasma and irradiated by a petawatt-class laser are shown to be a copious source of coherent broadband radiation. Simulations show that a dense sheet of relativistic electrons is formed during the interaction of the laser with the tenuous plasma between the two foils. The coherent motion of the electron sheet as it transits the second foil results in strong broadband emission in the extreme ultraviolet, consistent with our experimental observations.

16.
Phys Rev Lett ; 112(12): 123902, 2014 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-24724650

RESUMO

The polarization dependence of laser-driven coherent synchrotron emission transmitted through thin foils is investigated experimentally. The harmonic generation process is seen to be almost completely suppressed for circular polarization opening up the possibility of producing isolated attosecond pulses via polarization gating. Particle-in-cell simulations suggest that current laser pulses are capable of generating isolated attosecond pulses with high pulse energies.

17.
Clin Exp Allergy ; 43(9): 981-99, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23957346

RESUMO

Chronic inflammatory diseases (e.g. asthma and chronic obstructive pulmonary disease)are leading causes of morbidity and mortality world-wide and effective treatments are limited. These disorders can often be attributed to abnormal immune responses to environmental stimuli and infections. Mechanisms leading to inflammation are complex,resulting from interactions of structural cells and activation of both the adaptive and innate arms of the immune system. The activation of structural and immune cells involves both temporary and permanent changes in gene expression in these cells, which underpin chronic inflammation and tissue dysfunction. miRNAs are small non-coding RNAs increasingly being recognized to play important roles in the post-transcriptional regulation of gene expression in mammalian cells by regulating translation. Individual miRNA scan exert their effects by directly inhibiting the translation or stability of multiple mRNAs simultaneously. Thus, the expression or blockade of function of a single miRNA (miR) can result in pronounced alterations in protein expression within a given cell. Dysregulation of miRNA expression may subsequently alter cellular function, and in certain situations predispose to disease. Our current understanding of the role of miRNA in the regulation of inflammatory disease (e.g. allergic diseases) remains limited. In this review, we provide an overview of the current understanding of miRNA biogenesis and function, the roles miRNA play in the regulation of immune cell function and their potential contribution to inflammatory diseases. We also highlight strategies to alter miRNA function for experimental or therapeutic gain, and discuss the potential utility and limitations of targeting these molecules as anti-inflammatory strategies.


Assuntos
Regulação da Expressão Gênica , Inflamação/genética , Inflamação/terapia , MicroRNAs/genética , Biossíntese de Proteínas , Animais , Doenças Autoimunes/genética , Doenças Autoimunes/imunologia , Doenças Autoimunes/metabolismo , Humanos , Sistema Imunitário/imunologia , Sistema Imunitário/metabolismo , Inflamação/imunologia , MicroRNAs/metabolismo
18.
Diabet Med ; 30(10): 1209-13, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23586333

RESUMO

AIMS: To characterize temporal trends in the selection and timing of first-line pharmacotherapy among older patients with Type 2 diabetes. DESIGN AND METHODS: We studied five population-based cohorts every 3 years, from 1994 to 2006. In each of those years, we identified all subjects aged 66 years or older newly diagnosed with diabetes and determined the initial glucose-lowering drug and the time between diagnosis and drug initiation. We calculated the proportion of patients prescribed each agent and estimated time from diagnosis to initiation using Kaplan-Meier survival analysis. RESULTS: We identified a total of 64 368 eligible people who initiated drug therapy during the study period. From 1994 to 2006, first-line metformin use increased from 20.1 to 79.0%. Glyburide (glibenclamide) decreased from 71.1% of all first-line therapies in 1994 to 9.8% in 2006, while first-line use of insulin or combination therapy have changed little at approximately 5% each. No other medication exceeded 2% of first-line therapies. The median time from diagnosis to initiation of pharmacotherapy increased dramatically during the study period, from 1.8 years in 1994 to 4.6 years in 2006. CONCLUSIONS: Metformin has become the most commonly used initial medication for the treatment of diabetes. Although guidelines have evolved to recommend more aggressive initiation and intensification of pharmacotherapy, our results suggest that the time from diagnosis to initiation has increased substantially.


Assuntos
Glicemia/efeitos dos fármacos , Diabetes Mellitus Tipo 2/tratamento farmacológico , Hipoglicemiantes/uso terapêutico , Insulina/uso terapêutico , Metformina/uso terapêutico , Tempo para o Tratamento , Idoso , Glicemia/metabolismo , Estudos de Coortes , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/mortalidade , Progressão da Doença , Esquema de Medicação , Prática Clínica Baseada em Evidências , Feminino , Humanos , Hipoglicemiantes/administração & dosagem , Insulina/administração & dosagem , Estimativa de Kaplan-Meier , Masculino , Metformina/administração & dosagem , Seleção de Pacientes , Guias de Prática Clínica como Assunto , Resultado do Tratamento
19.
J Steroid Biochem Mol Biol ; 232: 106353, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37331434

RESUMO

A central part of human sulfation pathways is the spatially and temporally controlled desulfation of biologically highly potent steroid hormones. The responsible enzyme - steroid sulfatase (STS) - is highly expressed in placenta and peripheral tissues, such as fat, colon, and the brain. The shape of this enzyme and its mechanism are probably unique in biochemistry. STS was believed to be a transmembrane protein, spanning the Golgi double-membrane by stem region formed by two extended internal alpha-helices. New crystallographic data however challenge this view. STS now is portraited as a trimeric membrane-associated complex. We discuss the impact of these results on STS function and sulfation pathways in general and we hypothesis that this new STS structural understanding suggests product inhibition to be a regulator of STS enzymatic activity.


Assuntos
Placenta , Esteril-Sulfatase , Gravidez , Feminino , Humanos , Esteril-Sulfatase/metabolismo , Placenta/metabolismo , Esteroides , Proteínas de Membrana
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