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1.
J Am Chem Soc ; 146(13): 8915-8927, 2024 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-38517290

RESUMO

A barrier to understanding the factors driving catalysis in the oxygen evolution reaction (OER) is understanding multiple overlapping redox transitions in the OER catalysts. The complexity of these transitions obscure the relationship between the coverage of adsorbates and OER kinetics, leading to an experimental challenge in measuring activity descriptors, such as binding energies, as well as adsorbate interactions, which may destabilize intermediates and modulate their binding energies. Herein, we utilize a newly designed optical spectroelectrochemistry system to measure these phenomena in order to contrast the behavior of two electrocatalysts, cobalt oxyhydroxide (CoOOH) and cobalt-iron hexacyanoferrate (cobalt-iron Prussian blue, CoFe-PB). Three distinct optical spectra are observed in each catalyst, corresponding to three separate redox transitions, the last of which we show to be active for the OER using time-resolved spectroscopy and electrochemical mass spectroscopy. By combining predictions from density functional theory with parameters obtained from electroadsorption isotherms, we demonstrate that a destabilization of catalytic intermediates occurs with increasing coverage. In CoOOH, a strong (∼0.34 eV/monolayer) destabilization of a strongly bound catalytic intermediate is observed, leading to a potential offset between the accumulation of the intermediate and measurable O2 evolution. We contrast these data to CoFe-PB, where catalytic intermediate generation and O2 evolution onset coincide due to weaker binding and destabilization (∼0.19 eV/monolayer). By considering a correlation between activation energy and binding strength, we suggest that such adsorbate driven destabilization may account for a significant fraction of the observed OER catalytic activity in both materials. Finally, we disentangle the effects of adsorbate interactions on state coverages and kinetics to show how adsorbate interactions determine the observed Tafel slopes. Crucially, the case of CoFe-PB shows that, even where interactions are weaker, adsorption remains non-Nernstian, which strongly influences the observed Tafel slope.

2.
Biostatistics ; 25(1): 220-236, 2023 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-36610075

RESUMO

Trial-level surrogates are useful tools for improving the speed and cost effectiveness of trials but surrogates that have not been properly evaluated can cause misleading results. The evaluation procedure is often contextual and depends on the type of trial setting. There have been many proposed methods for trial-level surrogate evaluation, but none, to our knowledge, for the specific setting of platform studies. As platform studies are becoming more popular, methods for surrogate evaluation using them are needed. These studies also offer a rich data resource for surrogate evaluation that would not normally be possible. However, they also offer a set of statistical issues including heterogeneity of the study population, treatments, implementation, and even potentially the quality of the surrogate. We propose the use of a hierarchical Bayesian semiparametric model for the evaluation of potential surrogates using nonparametric priors for the distribution of true effects based on Dirichlet process mixtures. The motivation for this approach is to flexibly model relationships between the treatment effect on the surrogate and the treatment effect on the outcome and also to identify potential clusters with differential surrogate value in a data-driven manner so that treatment effects on the surrogate can be used to reliably predict treatment effects on the clinical outcome. In simulations, we find that our proposed method is superior to a simple, but fairly standard, hierarchical Bayesian method. We demonstrate how our method can be used in a simulated illustrative example (based on the ProBio trial), in which we are able to identify clusters where the surrogate is, and is not useful. We plan to apply our method to the ProBio trial, once it is completed.


Assuntos
Ensaios Clínicos como Assunto , Humanos , Teorema de Bayes , Resultado do Tratamento
3.
Biostatistics ; 24(4): 1017-1030, 2023 10 18.
Artigo em Inglês | MEDLINE | ID: mdl-36050911

RESUMO

When multiple mediators are present, there are additional effects that may be of interest beyond the well-known natural (NDE) and controlled direct effects (CDE). These effects cross the type of control on the mediators, setting one to a constant level and one to its natural level, which differs across subjects. We introduce five such estimands for the cross-CDE and -NDE when two mediators are measured. We consider both the scenario where one mediator is influenced by the other, referred to as sequential mediators, and the scenario where the mediators do not influence each other. Such estimands may be of interest in immunology, as we discuss in relation to measured immunological responses to SARS-CoV-2 vaccination. We provide identifying expressions for the estimands in observational settings where there is no residual confounding, and where intervention, outcome, and mediators are of arbitrary type. We further provide tight symbolic bounds for the estimands in randomized settings where there may be residual confounding of the outcome and mediator relationship and all measured variables are binary.


Assuntos
COVID-19 , Modelos Estatísticos , Humanos , Vacinas contra COVID-19 , COVID-19/prevenção & controle , SARS-CoV-2
4.
Stat Med ; 43(3): 534-547, 2024 02 10.
Artigo em Inglês | MEDLINE | ID: mdl-38096856

RESUMO

There are now many options for doubly robust estimation; however, there is a concerning trend in the applied literature to believe that the combination of a propensity score and an adjusted outcome model automatically results in a doubly robust estimator and/or to misuse more complex established doubly robust estimators. A simple alternative, canonical link generalized linear models (GLM) fit via inverse probability of treatment (propensity score) weighted maximum likelihood estimation followed by standardization (the g $$ g $$ -formula) for the average causal effect, is a doubly robust estimation method. Our aim is for the reader not just to be able to use this method, which we refer to as IPTW GLM, for doubly robust estimation, but to fully understand why it has the doubly robust property. For this reason, we define clearly, and in multiple ways, all concepts needed to understand the method and why it is doubly robust. In addition, we want to make very clear that the mere combination of propensity score weighting and an adjusted outcome model does not generally result in a doubly robust estimator. Finally, we hope to dispel the misconception that one can adjust for residual confounding remaining after propensity score weighting by adjusting in the outcome model for what remains 'unbalanced' even when using doubly robust estimators. We provide R code for our simulations and real open-source data examples that can be followed step-by-step to use and hopefully understand the IPTW GLM method. We also compare to a much better-known but still simple doubly robust estimator.


Assuntos
Modelos Estatísticos , Humanos , Simulação por Computador , Interpretação Estatística de Dados , Probabilidade , Pontuação de Propensão , Modelos Lineares
5.
Eur J Epidemiol ; 39(3): 313-322, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38212490

RESUMO

Sarcoidosis incidence peaks in women between 50 and 60 years old, which coincides with menopause, suggesting that certain sex hormones, mainly estrogen, may play a role in disease development. We investigated whether menopausal hormone therapy (MHT) was associated with sarcoidosis risk in women and whether the risk varied by treatment type. We performed a nested case-control study (2007-2020) including incident sarcoidosis cases from the Swedish National Patient Register (n = 2593) and matched (1:10) to general population controls (n = 20,003) on birth year, county, and living in Sweden at the time of sarcoidosis diagnosis. Dispensations of MHT were obtained from the Swedish Prescribed Drug Register before sarcoidosis diagnosis/matching. Adjusted odds ratios (aOR) of sarcoidosis were estimated using conditional logistic regression. Ever MHT use was associated with a 25% higher risk of sarcoidosis compared with never use (aOR 1.25, 95% CI 1.13-1.38). When MHT type and route of administration were considered together, systemic estrogen was associated with the highest risk of sarcoidosis (aOR 1.51, 95% CI 1.23-1.85), followed by local estrogen (aOR 1.25, 95% CI 1.11-1.42), while systemic estrogen-progestogen combined was associated with the lowest risk compared to never users (aOR 1.12, 95% CI 0.96-1.31). The aOR of sarcoidosis did not differ greatly by duration of MHT use. Our findings suggest that a history of MHT use is associated with increased risk of sarcoidosis, with women receiving estrogen administered systemically having the highest risk.


Assuntos
Menopausa , Sarcoidose , Humanos , Feminino , Pessoa de Meia-Idade , Estudos de Casos e Controles , Suécia/epidemiologia , Sarcoidose/epidemiologia , Sarcoidose/etiologia , Estrogênios/efeitos adversos , Terapia de Reposição de Estrogênios/efeitos adversos
6.
Br J Cancer ; 128(7): 1278-1285, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36690722

RESUMO

BACKGROUND: Medical advances in the treatment of cancer have allowed the development of multiple approved treatments and prognostic and predictive biomarkers for many types of cancer. Identifying improved treatment strategies among approved treatment options, the study of which is termed comparative effectiveness, using predictive biomarkers is becoming more common. RCTs that incorporate predictive biomarkers into the study design, called prediction-driven RCTs, are needed to rigorously evaluate these treatment strategies. Although researched extensively in the experimental treatment setting, literature is lacking in providing guidance about prediction-driven RCTs in the comparative effectiveness setting. METHODS: Realistic simulations with time-to-event endpoints are used to compare contrasts of clinical utility and provide examples of simulated prediction-driven RCTs in the comparative effectiveness setting. RESULTS: Our proposed contrast for clinical utility accurately estimates the true clinical utility in the comparative effectiveness setting while in some scenarios, the contrast used in current literature does not. DISCUSSION: It is important to properly define contrasts of interest according to the treatment setting. Realistic simulations should be used to choose and evaluate the RCT design(s) able to directly estimate that contrast. In the comparative effectiveness setting, our proposed contrast for clinical utility should be used.


Assuntos
Neoplasias , Projetos de Pesquisa , Humanos , Neoplasias/terapia
7.
Clin Gastroenterol Hepatol ; 21(12): 3132-3142, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37061104

RESUMO

BACKGROUND & AIMS: Earlier studies have provided varying risk estimates for lymphoma in patients with inflammatory bowel disease (IBD), but often have been limited by detection biases (especially during the first year of follow-up evaluation), misclassification, and small sample size; and rarely reflect modern-day management of IBD. METHODS: We performed a binational register-based cohort study (Sweden and Denmark) from 1969 to 2019. We compared 164,716 patients with IBD with 1,639,027 matched general population reference individuals. Cox regression estimated hazard ratios (HRs) for incident lymphoma by lymphoma subtype, excluding the first year of follow-up evaluation. RESULTS: From 1969 to 2019, 258 patients with Crohn's disease (CD), 479 patients with ulcerative colitis (UC), and 6675 matched reference individuals developed lymphoma. This corresponded to incidence rates of 35 (CD) and 34 (UC) per 100,000 person-years in IBD patients, compared with 28 and 33 per 100,000 person-years in their matched reference individuals. Although both CD (HR, 1.32; 95% CI, 1.16-1.50) and UC (HR, 1.09; 95% CI, 1.00-1.20) were associated with an increase in lymphoma, the 10-year cumulative incidence difference was low even in CD patients (0.08%; 95% CI, 0.02-0.13). HRs have increased in the past 2 decades, corresponding to increasing use of immunomodulators and biologics during the same time period. HRs were increased for aggressive B-cell non-Hodgkin lymphoma in CD and UC patients, and for T-cell non-Hodgkin lymphoma in CD patients. Although the highest HRs were observed in patients exposed to combination therapy (immunomodulators and biologics) or second-line biologics, we also found increased HRs in patients naïve to such drugs. CONCLUSIONS: During the past 20 years, the risk of lymphomas have increased in CD, but not in UC, and were driven mainly by T-cell lymphomas and aggressive B-cell lymphomas.


Assuntos
Produtos Biológicos , Colite Ulcerativa , Doença de Crohn , Doenças Inflamatórias Intestinais , Linfoma não Hodgkin , Linfoma , Humanos , Colite Ulcerativa/complicações , Doença de Crohn/complicações , Estudos de Coortes , Doenças Inflamatórias Intestinais/complicações , Linfoma/epidemiologia , Linfoma/complicações , Fatores Imunológicos , Produtos Biológicos/uso terapêutico , Linfoma não Hodgkin/complicações , Incidência
8.
Dig Dis Sci ; 68(9): 3596-3604, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37548896

RESUMO

BACKGROUND: Crohn's disease recurrence after ileocecal resection is common. Guidelines suggest colonoscopy within 6-12 months of surgery to assess for post-operative recurrence, but use of adjunctive monitoring is not protocolized. We aimed to describe the state of monitoring in post-operative Crohn's. METHODS: We conducted a retrospective study of patients with Crohn's after ileocolic resection with ≥ 1-year follow-up. Patients were stratified into high and low risk based on guidelines. Post-operative biomarker (C-reactive protein, fecal calprotectin), cross-sectional imaging, and colonoscopy use were assessed. Biomarker, radiographic, and endoscopic post-operative recurrence were defined as elevated CRP/calprotectin, active inflammation on imaging, and Rutgeerts ≥ i2b, respectively. Data were stratified by surgery year to assess changes in practice patterns over time. P-values were calculated using Wilcoxon test and Fisher exact test. RESULTS: Of 901 patients, 53% were female and 78% high risk. Median follow-up time was 60 m for LR and 50 m for high risk. Postoperatively, 18% low and 38% high risk had CRPs, 5% low and 10% high risk had calprotectins, and half of low and high risk had cross-sectional imaging. 29% low and 38% high risk had colonoscopy by 1 year. Compared to pre-2015, time to first radiography (584 days vs. 398 days) and colonoscopy (421 days vs. 296 days) were significantly shorter for high-risk post-2015 (P < 0.001). Probability of colonoscopy within 1 year increased over time (0.48, 2011 vs. 0.92, 2019). CONCLUSION: Post-operative colonoscopy completion by 1 year is low. The use of CRP and imaging are common, whereas calprotectin is infrequently utilized. Practice patterns are shifting toward earlier monitoring.


Assuntos
Doença de Crohn , Humanos , Feminino , Masculino , Doença de Crohn/diagnóstico por imagem , Doença de Crohn/cirurgia , Estudos Retrospectivos , Fidelidade a Diretrizes , Biomarcadores/metabolismo , Colonoscopia , Complexo Antígeno L1 Leucocitário/metabolismo , Recidiva , Fezes/química , Íleo/cirurgia
9.
Br J Cancer ; 127(9): 1636-1641, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-35986088

RESUMO

BACKGROUND: Providing estimates of uncertainty for statistical quantities is important for statistical inference. When the statistical quantity of interest is a survival curve, which is a function over time, the appropriate type of uncertainty estimate is a confidence band constructed to account for the correlation between points on the curve, we will call this a simultaneous confidence band. This, however, is not the type of confidence band provided in standard software, which is constructed by joining the confidence intervals at given time points. METHODS: We show that this type of band does not have desirable joint/simultaneous coverage properties in comparison to simultaneous bands. RESULTS: There are different ways of constructing simultaneous confidence bands, and we find that bands based on the likelihood ratio appear to have the most desirable properties. Although there is no standard software available in the three major statistical packages to compute likelihood-based simultaneous bands, we summarise and give code to use available statistical software to construct other simultaneous forms of bands, which we illustrate using a study of colon cancer. CONCLUSIONS: There is a need for more user-friendly statistical software to compute simultaneous confidence bands using the available methods.


Assuntos
Software , Humanos , Funções Verossimilhança , Análise de Sobrevida , Incerteza , Intervalos de Confiança
10.
J Biopharm Stat ; 32(6): 858-870, 2022 11 02.
Artigo em Inglês | MEDLINE | ID: mdl-35574690

RESUMO

There have been many strategies to adapt machine learning algorithms to account for right censored observations in survival data in order to build more accurate risk prediction models. These adaptions have included pre-processing steps such as pseudo-observation transformation of the survival outcome or inverse probability of censoring weighted (IPCW) bootstrapping of the observed binary indicator of an event prior to a time point of interest. These pre-processing steps allow existing or newly developed machine learning methods, which were not specifically developed with time-to-event data in mind, to be applied to right censored survival data for predicting the risk of experiencing an event. Stacking or ensemble methods can improve on risk predictions, but in general, the combination of pseudo-observation-based algorithms, IPCW bootstrapping, IPC weighting of the methods directly, and methods developed specifically for survival has not been considered in the same ensemble. In this paper, we propose an ensemble procedure based on the area under the pseudo-observation-based-time-dependent ROC curve to optimally stack predictions from any survival or survival adapted algorithm. The real application results show that our proposed method can improve on single survival based methods such as survival random forest or on other strategies that use a pre-processing step such as inverse probability of censoring weighted bagging or pseudo-observations alone.


Assuntos
Algoritmos , Algoritmo Florestas Aleatórias , Humanos , Área Sob a Curva , Probabilidade , Curva ROC , Análise de Sobrevida
11.
BMC Pulm Med ; 22(1): 43, 2022 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-35073900

RESUMO

BACKGROUND: Sarcoidosis incidence peaks in females around the fifth decade of life, which coincides with menopause, suggesting hormonal factors play a role in disease development. We investigated whether longer exposure to reproductive and hormonal factors is associated with reduced sarcoidosis risk. METHODS: We conducted a matched case-control study nested within the Mammography Screening Project. Incident sarcoidosis cases were identified via medical records and matched to controls on birth and questionnaire date (1:4). Information on hormonal factors was obtained through questionnaires prior to sarcoidosis diagnosis. Multilevel modelling was used to estimate adjusted odds ratios with 95% credible intervals (OR; 95% CI). RESULTS: In total, 32 sarcoidosis cases and 124 controls were included. Higher sarcoidosis odds were associated with older age at menarche (OR 1.19: 95% CI 0.92-1.55), natural menopause versus non-natural (OR 1.53: 95% CI 0.80-2.93), later age at first pregnancy (OR 1.11: 95% CI 0.76-1.63) and ever hormone replacement therapy (HRT) use (OR 1.40: 95% CI 0.76-2.59). Lower odds were associated with older age at menopause (OR 0.90: 95% CI 0.52-1.55), longer duration of oral contraceptive use (OR 0.70: 95% CI 0.45-1.07), longer duration of HRT use (OR 0.61: 95% CI 0.22-1.70), ever local estrogen therapy (LET) use (OR 0.83: 95% CI 0.34-2.04) and longer duration of LET use (OR 0.78: 95% CI 0.21-2.81). However, the CIs could not rule out null associations. CONCLUSION: Given the inconsistency and modest magnitude in our estimates, and that the 95% credible intervals included one, it still remains unclear whether longer estrogen exposure is associated with reduced sarcoidosis risk.


Assuntos
Estrogênios/metabolismo , Sarcoidose/epidemiologia , Sarcoidose/prevenção & controle , Adolescente , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Feminino , Hormônios , Humanos , Menopausa , Pessoa de Meia-Idade , Reprodução , Fatores de Risco , Inquéritos e Questionários , Suécia/epidemiologia , Adulto Jovem
12.
Gut ; 70(2): 297-308, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-32474410

RESUMO

OBJECTIVE: Crohn's disease (CD) is associated with increased risk of small bowel cancer (SBC), but previous studies have been small. We aimed to examine the risk of incident SBC and death from SBC in patients with inflammatory bowel disease (IBD). DESIGN: In a binational, population-based cohort study from Sweden and Denmark of patients with IBD during 1969-2017 and matched reference individuals from the general population, we evaluated the risk of incident SBC and death from SBC. Cox regression was used to estimate adjusted hazard ratios (aHRs). RESULTS: We identified 161 896 individuals with IBD (CD: 47 370; UC: 97 515; unclassified IBD: 17 011). During follow-up, 237 cases of SBC were diagnosed in patients with IBD (CD: 24.4/100 000 person-years; UC: 5.88/100 000 person-years), compared with 640 cases in reference individuals (2.81/100 000 person-years and 3.32/100 000 person-years, respectively). This corresponded to one extra case of SBC in 385 patients with CD and one extra case in 500 patients with UC, followed up for 10 years. The aHR for incident SBC was 9.09 (95% CI 7.34 to 11.3) in CD and 1.85 (95% CI 1.43 to 2.39) in UC. Excluding the first year after an IBD diagnosis, the aHRs for incident SBC decreased to 4.96 in CD and 1.69 in UC. Among patients with CD, HRs were independently highest for recently diagnosed, childhood-onset, ileal and stricturing CD. The relative hazard of SBC-related death was increased in both patients with CD (aHR 6.59, 95% CI 4.74 to 9.15) and patients with UC (aHR 1.57; 95% CI 1.07 to 2.32). CONCLUSION: SBC and death from SBC were more common in patients with IBD, particularly among patients with CD, although absolute risks were low.


Assuntos
Doenças Inflamatórias Intestinais/complicações , Neoplasias Intestinais/etiologia , Adolescente , Adulto , Colite Ulcerativa/complicações , Doença de Crohn/complicações , Dinamarca/epidemiologia , Feminino , Humanos , Incidência , Neoplasias Intestinais/epidemiologia , Neoplasias Intestinais/mortalidade , Masculino , Pessoa de Meia-Idade , Modelos de Riscos Proporcionais , Fatores de Risco , Suécia/epidemiologia , Adulto Jovem
13.
Lancet ; 395(10218): 123-131, 2020 01 11.
Artigo em Inglês | MEDLINE | ID: mdl-31929014

RESUMO

BACKGROUND: Ulcerative colitis (UC) is a risk factor for colorectal cancer (CRC). However, available studies reflect older treatment and surveillance paradigms, and most have assessed risks for incident CRC without taking surveillance and lead-time bias into account, such as by assessing CRC incidence by tumour stage, or stage-adjusted mortality from CRC. We aimed to compare both overall and country-specific risks of CRC mortality and incident CRC among patients with UC. METHODS: In this population-based cohort study of 96 447 patients with UC in Denmark (n=32 919) and Sweden (n=63 528), patients were followed up for CRC incidence and CRC mortality between Jan 1, 1969, and Dec 31, 2017, and compared with matched reference individuals from the general population (n=949 207). Patients with UC were selected from national registers and included in the analysis if they had two or more records with a relevant International Classification of Disease in the patient register (in the country in question) or one such record plus a colorectal biopsy report with a morphology code suggestive of inflammatory bowel disease. For every patient with UC, we selected matched reference individuals from the total population registers of Denmark and Sweden, who were matched for sex, age, birth year, and place of residence. We used Cox regression to compute hazard ratios (HRs) for incident CRC, and for CRC mortality, taking tumour stage into account. FINDINGS: During follow-up, we observed 1336 incident CRCs in the UC cohort (1·29 per 1000 person-years) and 9544 incident CRCs in reference individuals (0·82 per 1000 person-years; HR 1·66, 95% CI 1·57-1·76). In the UC cohort, 639 patients died from CRC (0·55 per 1000 person-years), compared with 4451 reference individuals (0·38 per 1000 person-years; HR 1·59, 95% CI 1·46-1·72) during the same time period. The CRC stage distribution in people with UC was less advanced (p<0·0001) than in matched reference individuals, but taking tumour stage into account, patients with UC and CRC remained at increased risk of CRC death (HR 1·54, 95% CI 1·33-1·78). The excess risks declined over calendar periods: during the last 5 years of follow-up (2013-17, Sweden only), the HR for incident CRC in people with UC was 1·38 (95% CI 1·20-1·60, or one additional case per 1058 patients with UC per 5 years) and the HR for death from CRC was 1·25 (95% CI 1·03-1·51, or one additional case per 3041 patients with UC per 5 years). INTERPRETATION: Compared with those without UC, individuals with UC are at increased risk of developing CRC, are diagnosed with less advanced CRC, and are at increased risk of dying from CRC, although these excess risks have declined substantially over time. There still seems to be room for improvement in international surveillance guidelines. FUNDING: The Swedish Medical Society, Karolinska Institutet, Stockholm County Council, Swedish Research Council, Swedish Foundation for Strategic Research, Independent Research Fund Denmark, Forte Foundation, Swedish Cancer Foundation.


Assuntos
Colite Ulcerativa/epidemiologia , Neoplasias Colorretais/epidemiologia , Neoplasias Colorretais/patologia , Adulto , Idoso , Estudos de Coortes , Colite Ulcerativa/complicações , Colite Ulcerativa/mortalidade , Neoplasias Colorretais/mortalidade , Dinamarca/epidemiologia , Feminino , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Modelos de Riscos Proporcionais , Sistema de Registros , Suécia/epidemiologia , Adulto Jovem
14.
Gastroenterology ; 158(6): 1574-1583.e2, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-31926169

RESUMO

BACKGROUND & AIMS: Microscopic colitis shares pathogenetic mechanisms with inflammatory bowel disease (IBD). We studied the association between microscopic colitis and risk of incident IBD using data from a nationwide cohort study. METHODS: We conducted a prospective cohort study of all adults who received a diagnosis of microscopic colitis from 1990 through 2017 in Sweden and risk of incident IBD. Cases of microscopic colitis (n= 13,957) were identified through Systematized Nomenclature of Medicine codes from the ESPRESSO (Epidemiology Strengthened by histoPathology Reports in Sweden) study, which included gastrointestinal pathology reports from all of Sweden's 28 centers. Individuals with microscopic colitis were matched to 5 general population controls (n = 66,820) and to unaffected siblings (n =13,943). Cox regression was used to estimate adjusted hazard ratio (aHRs) and 95% confidence intervals (CIs). RESULTS: Through December of 2017, we identified 323 incident cases of ulcerative colitis (UC) and 108 incident cases of Crohn's disease (CD) in patients with microscopic colitis compared with 94 UC and 42 CD cases in population comparators. Mean times from diagnosis of microscopic colitis to diagnosis of CD was 3.3 ± 3.2 years and to diagnosis of UC was 3.2 ± 3.5 years. In multivariable models, microscopic colitis was associated with an aHR of 12.6 (95% CI 8.8-18.1) for CD, 17.3 (95% CI 13.7-21.8) for UC, and 16.8 (95% CI 13.9-20.3) for IBD. The 10-year absolute excess risks of CD and UC were 0.9 (95% CI 0.7-1.1) and 2.6 (95% CI 2.2-2.9) percentage points, respectively. In sensitivity analyses, comparing patients with microscopic colitis with their unaffected siblings, the aHRs of CD and UC were 5.4 (95% CI 3.2-9.2) and 9.4 (95% CI 6.4-13.8), respectively. CONCLUSIONS: In a population-based study in Sweden, we found a significant increase in risk of incident IBD among patients with microscopic colitis. Future studies should focus on potential mechanisms underlying these observed associations.


Assuntos
Colite Microscópica/epidemiologia , Colite Ulcerativa/epidemiologia , Doença de Crohn/epidemiologia , Adulto , Idoso , Biópsia/estatística & dados numéricos , Estudos de Casos e Controles , Colite Microscópica/complicações , Colite Microscópica/patologia , Colite Ulcerativa/diagnóstico , Colite Ulcerativa/etiologia , Colite Ulcerativa/patologia , Colo/patologia , Doença de Crohn/diagnóstico , Doença de Crohn/etiologia , Doença de Crohn/patologia , Feminino , Seguimentos , Humanos , Incidência , Mucosa Intestinal/patologia , Masculino , Pessoa de Meia-Idade , Prevalência , Estudos Prospectivos , Sistema de Registros/estatística & dados numéricos , Fatores de Risco , Suécia/epidemiologia
15.
Nat Mater ; 19(5): 559-565, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32015530

RESUMO

Photocatalysts formed from a single organic semiconductor typically suffer from inefficient intrinsic charge generation, which leads to low photocatalytic activities. We demonstrate that incorporating a heterojunction between a donor polymer (PTB7-Th) and non-fullerene acceptor (EH-IDTBR) in organic nanoparticles (NPs) can result in hydrogen evolution photocatalysts with greatly enhanced photocatalytic activity. Control of the nanomorphology of these NPs was achieved by varying the stabilizing surfactant employed during NP fabrication, converting it from a core-shell structure to an intermixed donor/acceptor blend and increasing H2 evolution by an order of magnitude. The resulting photocatalysts display an unprecedentedly high H2 evolution rate of over 60,000 µmol h-1 g-1 under 350 to 800 nm illumination, and external quantum efficiencies over 6% in the region of maximum solar photon flux.

16.
J Pediatr ; 238: 66-73.e1, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34216628

RESUMO

OBJECTIVE: To assess absolute and relative risks of serious infections (resulting in inpatient care) in children with inflammatory bowel disease (IBD) compared with the general population. STUDY DESIGN: We identified children (<18 years of age) with a first diagnosis of IBD in the Swedish nationwide health registry (2002-2017; n = 5767) and individuals from the general population matched for sex, age, calendar year, and place of residence (reference group; n = 58 418). Hazard ratios (HRs) for serious infections were estimated using Cox regression separately in children with ulcerative colitis (n = 2287), Crohn's disease (n = 2365), and IBD unclassified (n = 1115). RESULTS: During 17 408 person-years of follow-up, 672 serious infections (38.6/1000 person-years) occurred among the children with IBD compared with 778 serious infections in the reference group (4.0/1000 person-years; adjusted HR (95% CI), 9.46 [8.53-10.5]). HRs were increased for children with ulcerative colitis 8.48 (7.21-9.98), Crohn's disease 9.30 (7.86-11.0), and IBD unclassified 12.1 (9.66-16.1). HRs were highest in the first year of follow-up (HR = 12.6 [10.7-14.9]), then decreasing to a 4.8-fold increased risk beyond 10 years of follow-up. Particularly high HRs were also seen in children with IBD undergoing surgery. Apart from a high relative risk of gastrointestinal infections resulting in hospitalization, children with IBD were also at an increased risk of opportunistic infections (HR = 11.8 [6.17-22.5]). CONCLUSIONS: Children with IBD have an increased risk of serious infection requiring hospitalization compared with the general population.


Assuntos
Colite Ulcerativa/epidemiologia , Doença de Crohn/epidemiologia , Adolescente , Estudos de Casos e Controles , Criança , Estudos de Coortes , Feminino , Hospitalização/estatística & dados numéricos , Humanos , Incidência , Estimativa de Kaplan-Meier , Masculino , Modelos de Riscos Proporcionais , Sistema de Registros , Índice de Gravidade de Doença
17.
Scand J Gastroenterol ; 56(10): 1152-1162, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34369254

RESUMO

OBJECTIVES: To investigate absolute and relative risk of serious infections in adult/elderly inflammatory bowel disease (IBD) diagnosed 2002-2017. METHODS: Nationwide, register-based cohort study of Swedish patients with IBD compared with general population matched reference individuals with regard to time to first serious infection, equal to hospital admission. Multivariable Cox regression estimated hazard ratios (HRs) for any serious infection. Secondary outcomes included site-specific infections, opportunistic infections and sepsis. RESULTS: We identified 47 798 individuals with IBD. During a follow-up of 329 000 person-years, they had 8752 first serious infections (26.6 per 1000 person-years). This compared with an incidence rate of 10.7 per 1000 person-years in matched reference individuals, corresponding to a 2.53-fold increased hazard of serious infections (95%CI = 2.47-2.59). The HR for serious infection in elderly-onset IBD was 2.01 (95%CI = 1.95-2.08). The relative hazard of serious infection was somewhat higher in Crohn's disease (2.94; 95%CI = 2.81-3.06) than in ulcerative colitis (2.24; 95%CI = 2.17-2.31). The HR for serious infections was high in the first year of follow-up (5.17; 95%CI = 4.93-5.42). Individuals with IBD were at a particularly high relative hazard of gastrointestinal and opportunistic infections. The HR for sepsis was 2.47 (95%CI = 2.32-2.63). The relative rates for serious infections in IBD increased in recent years. CONCLUSIONS: Patients with adult-onset IBD are at increased risk of serious infections, particularly gastrointestinal and opportunistic infections. Relative rates were highest just after IBD diagnosis, and seem to have increased in recent years.


Assuntos
Colite Ulcerativa , Doença de Crohn , Doenças Inflamatórias Intestinais , Adulto , Idoso , Estudos de Coortes , Colite Ulcerativa/epidemiologia , Doença de Crohn/epidemiologia , Humanos , Incidência , Doenças Inflamatórias Intestinais/epidemiologia
18.
Scand J Gastroenterol ; 56(4): 410-421, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33632044

RESUMO

BACKGROUND: It is not known to what extent biologic treatment for IBD is captured in the Swedish Prescribed Drug Register (PDR) and the National Patient Register (NPR). METHODS: A cross-sectional study from July 2005 until 2017, comparing data on biologic treatment in the PDR and the NPR with medical records. We assessed the proportion of started treatment episodes in the medical records that were found in the PDR/NPR ever, within +/- one year and within +/- three months; for any biologic drug, per specific drug (infliximab, adalimumab, golimumab, vedolizumab, ustekinumab), by calendar period (2005-2008, 2009-2012, and 2013-2017) and by study center. For adalimumab, we assessed the validity of end of treatment episodes. RESULTS: Medical records of 1361 patients and 2323 treatment episodes with any biologic were reviewed and 80.1% (95% CI: 78.4-81.7) were ever captured in the PDR/NPR in. A time window of +/- one year or +/- three months reduced the sensitivity to 63.3% (95% CI: 61.3-65.3) and 52.6% (95% CI: 50.5-54.6), respectively. The sensitivity was high (>85%) for the prescribed injection drugs adalimumab, golimumab, and ustekinumab for all time windows and for adalimumab end of treatment, while considerably lower for the infusion drugs infliximab and vedolizumab. CONCLUSIONS: The PDR and the NPR are reliable data sources on treatment with injection biologics in patients with IBD in Sweden. Infliximab and vedolizumab are poorly captured, why PDR/NPR data should only be used after careful consideration of their limitations or complemented by other data sources, e.g., the disease-specific quality register SWIBREG.


Assuntos
Produtos Biológicos , Doenças Inflamatórias Intestinais , Preparações Farmacêuticas , Adalimumab/uso terapêutico , Produtos Biológicos/uso terapêutico , Estudos Transversais , Humanos , Doenças Inflamatórias Intestinais/tratamento farmacológico , Infliximab/uso terapêutico , Suécia
19.
Gut ; 69(3): 453-461, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31092591

RESUMO

OBJECTIVES: To examine all-cause and cause-specific mortality in adult-onset and elderly-onset IBD and to describe time trends in mortality over the past 50 years. DESIGN: Swedish nationwide register-based cohort study 1964-2014, comparing mortality in 82 718 incident IBD cases (inpatient and non-primary outpatient care) with 10 times as many matched general population reference individuals (n=801 180) using multivariable Cox regression to estimate HRs. Among patients with IBD, the number of participants with elderly-onset (≥60 years) IBD was 17 873. RESULTS: During 984 330 person-years of follow-up, 15 698/82 718 (19%) of all patients with IBD died (15.9/1000 person-years) compared with 121 095/801 180 (15.1%) of reference individuals, corresponding to an HR of 1.5 for IBD (95% CI=1.5 to 1.5 (HR=1.5; 95% CI=1.5 to 1.5 in elderly-onset IBD)) or one extra death each year per 263 patients. Mortality was increased specifically for UC (HR=1.4; 95% CI=1.4 to 1.5), Crohn's disease (HR=1.6; 95% CI=1.6 to 1.7) and IBD-unclasssified (HR=1.6; 95% CI=1.5 to 1.8). IBD was linked to increased rates of multiple causes of death, including cardiovascular disease (HR=1.3; 1.3 to 1.3), malignancy (HR=1.4; 1.4 to 1.5) and digestive disease (HR=5.2; 95% CI=4.9 to 5.5). Relative mortality during the first 5 years of follow-up decreased significantly over time. Incident cases of 2002-2014 had 2.3 years shorter mean estimated life span than matched comparators. CONCLUSIONS: Adult-onset and elderly-onset patients with UC, Crohn's disease and IBD-unclassified were all at increased risk of death. The increased mortality remained also after the introduction of biological therapies but has decreased over time.


Assuntos
Doenças Cardiovasculares/mortalidade , Causas de Morte , Colite Ulcerativa/mortalidade , Doença de Crohn/mortalidade , Neoplasias/mortalidade , Adolescente , Adulto , Idade de Início , Idoso , Estudos de Casos e Controles , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Mortalidade/tendências , Modelos de Riscos Proporcionais , Sistema de Registros , Suécia/epidemiologia , Adulto Jovem
20.
J Am Chem Soc ; 142(34): 14574-14587, 2020 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-32786800

RESUMO

Semiconducting polymers are versatile materials for solar energy conversion and have gained popularity as photocatalysts for sunlight-driven hydrogen production. Organic polymers often contain residual metal impurities such as palladium (Pd) clusters that are formed during the polymerization reaction, and there is increasing evidence for a catalytic role of such metal clusters in polymer photocatalysts. Using transient and operando optical spectroscopy on nanoparticles of F8BT, P3HT, and the dibenzo[b,d]thiophene sulfone homopolymer P10, we demonstrate how differences in the time scale of electron transfer to Pd clusters translate into hydrogen evolution activity optima at different residual Pd concentrations. For F8BT nanoparticles with common Pd concentrations of >1000 ppm (>0.1 wt %), we find that residual Pd clusters quench photogenerated excitons via energy and electron transfer on the femto-nanosecond time scale, thus outcompeting reductive quenching. We spectroscopically identify reduced Pd clusters in our F8BT nanoparticles from the microsecond time scale onward and show that the predominant location of long-lived electrons gradually shifts to the F8BT polymer when the Pd content is lowered. While a low yield of long-lived electrons limits the hydrogen evolution activity of F8BT, P10 exhibits a substantially higher hydrogen evolution activity, which we demonstrate results from higher yields of long-lived electrons due to more efficient reductive quenching. Surprisingly, and despite the higher performance of P10, long-lived electrons reside on the P10 polymer rather than on the Pd clusters in P10 particles, even at very high Pd concentrations of 27000 ppm (2.7 wt %). In contrast, long-lived electrons in F8BT already reside on Pd clusters before the typical time scale of hydrogen evolution. This comparison shows that P10 exhibits efficient reductive quenching but slow electron transfer to residual Pd clusters, whereas the opposite is the case for F8BT. These findings suggest that the development of even more efficient polymer photocatalysts must target materials that combine both rapid reductive quenching and rapid charge transfer to a metal-based cocatalyst.

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