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1.
N Engl J Med ; 386(4): 340-350, 2022 01 27.
Artigo em Inglês | MEDLINE | ID: mdl-35021002

RESUMO

BACKGROUND: Vaccines against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus that causes coronavirus disease 2019 (Covid-19), have been used since December 2020 in the United Kingdom. Real-world data have shown the vaccines to be highly effective against Covid-19 and related severe disease and death. Vaccine effectiveness may wane over time since the receipt of the second dose of the ChAdOx1-S (ChAdOx1 nCoV-19) and BNT162b2 vaccines. METHODS: We used a test-negative case-control design to estimate vaccine effectiveness against symptomatic Covid-19 and related hospitalization and death in England. Effectiveness of the ChAdOx1-S and BNT162b2 vaccines was assessed according to participant age and status with regard to coexisting conditions and over time since receipt of the second vaccine dose to investigate waning of effectiveness separately for the B.1.1.7 (alpha) and B.1.617.2 (delta) variants. RESULTS: Vaccine effectiveness against symptomatic Covid-19 with the delta variant peaked in the early weeks after receipt of the second dose and then decreased by 20 weeks to 44.3% (95% confidence interval [CI], 43.2 to 45.4) with the ChAdOx1-S vaccine and to 66.3% (95% CI, 65.7 to 66.9) with the BNT162b2 vaccine. Waning of vaccine effectiveness was greater in persons 65 years of age or older than in those 40 to 64 years of age. At 20 weeks or more after vaccination, vaccine effectiveness decreased less against both hospitalization, to 80.0% (95% CI, 76.8 to 82.7) with the ChAdOx1-S vaccine and 91.7% (95% CI, 90.2 to 93.0) with the BNT162b2 vaccine, and death, to 84.8% (95% CI, 76.2 to 90.3) and 91.9% (95% CI, 88.5 to 94.3), respectively. Greater waning in vaccine effectiveness against hospitalization was observed in persons 65 years of age or older in a clinically extremely vulnerable group and in persons 40 to 64 years of age with underlying medical conditions than in healthy adults. CONCLUSIONS: We observed limited waning in vaccine effectiveness against Covid-19-related hospitalization and death at 20 weeks or more after vaccination with two doses of the ChAdOx1-S or BNT162b2 vaccine. Waning was greater in older adults and in those in a clinical risk group.


Assuntos
Vacina BNT162 , COVID-19/prevenção & controle , ChAdOx1 nCoV-19 , Eficácia de Vacinas , Adolescente , Adulto , Fatores Etários , Idoso , COVID-19/mortalidade , COVID-19/virologia , Estudos de Casos e Controles , Feminino , Hospitalização/estatística & dados numéricos , Humanos , Imunização Secundária , Imunogenicidade da Vacina , Masculino , Pessoa de Meia-Idade , Gravidade do Paciente , Fatores de Risco , SARS-CoV-2 , Fatores de Tempo , Reino Unido/epidemiologia
2.
N Engl J Med ; 386(16): 1532-1546, 2022 04 21.
Artigo em Inglês | MEDLINE | ID: mdl-35249272

RESUMO

BACKGROUND: A rapid increase in coronavirus disease 2019 (Covid-19) cases due to the omicron (B.1.1.529) variant of severe acute respiratory syndrome coronavirus 2 in highly vaccinated populations has aroused concerns about the effectiveness of current vaccines. METHODS: We used a test-negative case-control design to estimate vaccine effectiveness against symptomatic disease caused by the omicron and delta (B.1.617.2) variants in England. Vaccine effectiveness was calculated after primary immunization with two doses of BNT162b2 (Pfizer-BioNTech), ChAdOx1 nCoV-19 (AstraZeneca), or mRNA-1273 (Moderna) vaccine and after a booster dose of BNT162b2, ChAdOx1 nCoV-19, or mRNA-1273. RESULTS: Between November 27, 2021, and January 12, 2022, a total of 886,774 eligible persons infected with the omicron variant, 204,154 eligible persons infected with the delta variant, and 1,572,621 eligible test-negative controls were identified. At all time points investigated and for all combinations of primary course and booster vaccines, vaccine effectiveness against symptomatic disease was higher for the delta variant than for the omicron variant. No effect against the omicron variant was noted from 20 weeks after two ChAdOx1 nCoV-19 doses, whereas vaccine effectiveness after two BNT162b2 doses was 65.5% (95% confidence interval [CI], 63.9 to 67.0) at 2 to 4 weeks, dropping to 8.8% (95% CI, 7.0 to 10.5) at 25 or more weeks. Among ChAdOx1 nCoV-19 primary course recipients, vaccine effectiveness increased to 62.4% (95% CI, 61.8 to 63.0) at 2 to 4 weeks after a BNT162b2 booster before decreasing to 39.6% (95% CI, 38.0 to 41.1) at 10 or more weeks. Among BNT162b2 primary course recipients, vaccine effectiveness increased to 67.2% (95% CI, 66.5 to 67.8) at 2 to 4 weeks after a BNT162b2 booster before declining to 45.7% (95% CI, 44.7 to 46.7) at 10 or more weeks. Vaccine effectiveness after a ChAdOx1 nCoV-19 primary course increased to 70.1% (95% CI, 69.5 to 70.7) at 2 to 4 weeks after an mRNA-1273 booster and decreased to 60.9% (95% CI, 59.7 to 62.1) at 5 to 9 weeks. After a BNT162b2 primary course, the mRNA-1273 booster increased vaccine effectiveness to 73.9% (95% CI, 73.1 to 74.6) at 2 to 4 weeks; vaccine effectiveness fell to 64.4% (95% CI, 62.6 to 66.1) at 5 to 9 weeks. CONCLUSIONS: Primary immunization with two doses of ChAdOx1 nCoV-19 or BNT162b2 vaccine provided limited protection against symptomatic disease caused by the omicron variant. A BNT162b2 or mRNA-1273 booster after either the ChAdOx1 nCoV-19 or BNT162b2 primary course substantially increased protection, but that protection waned over time. (Funded by the U.K. Health Security Agency.).


Assuntos
Vacinas contra COVID-19 , COVID-19 , Eficácia de Vacinas , Vacina de mRNA-1273 contra 2019-nCoV/uso terapêutico , Vacina BNT162/uso terapêutico , COVID-19/prevenção & controle , Vacinas contra COVID-19/uso terapêutico , Estudos de Casos e Controles , ChAdOx1 nCoV-19/uso terapêutico , Humanos , Imunização Secundária/efeitos adversos , SARS-CoV-2/genética
3.
Bioinformatics ; 40(4)2024 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-38603611

RESUMO

MOTIVATION: Recent advancements in sequencing technologies have led to the discovery of numerous variants in the human genome. However, understanding their precise roles in diseases remains challenging due to their complex functional mechanisms. Various methodologies have emerged to predict the pathogenic significance of these genetic variants. Typically, these methods employ an integrative approach, leveraging diverse data sources that provide important insights into genomic function. Despite the abundance of publicly available data sources and databases, the process of navigating, extracting, and pre-processing features for machine learning models can be highly challenging and time-consuming. Furthermore, researchers often invest substantial effort in feature extraction, only to later discover that these features lack informativeness. RESULTS: In this article, we introduce DrivR-Base, an innovative resource that efficiently extracts and integrates molecular information (features) related to single nucleotide variants. These features encompass information about the genomic positions and the associated protein positions of a variant. They are derived from a wide array of databases and tools, including structural properties obtained from AlphaFold, regulatory information sourced from ENCODE, and predicted variant consequences from Variant Effect Predictor. DrivR-Base is easily deployable via a Docker container to ensure reproducibility and ease of access across diverse computational environments. The resulting features can be used as input for machine learning models designed to predict the pathogenic impact of human genome variants in disease. Moreover, these feature sets have applications beyond this, including haploinsufficiency prediction and the development of drug repurposing tools. We describe the resource's development, practical applications, and potential for future expansion and enhancement. AVAILABILITY AND IMPLEMENTATION: DrivR-Base source code is available at https://github.com/amyfrancis97/DrivR-Base.


Assuntos
Genoma Humano , Humanos , Software , Aprendizado de Máquina , Bases de Dados Genéticas , Polimorfismo de Nucleotídeo Único , Genômica/métodos , Biologia Computacional/métodos , Variação Genética
4.
Nucleic Acids Res ; 51(22): 12174-12184, 2023 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-37843153

RESUMO

DNA-protein crosslinks (DPCs) are large cytotoxic DNA lesions that form following exposure to chemotherapeutic drugs and environmental chemicals. Nucleotide excision repair (NER) and homologous recombination (HR) promote survival following exposure to DPC-inducing agents. However, it is not known how cells recognize DPC lesions, or what mechanisms selectively target DPC lesions to these respective repair pathways. To address these questions, we examined DPC recognition and repair by transfecting a synthetic DPC lesion comprised of the human oxoguanine glycosylase (OGG1) protein crosslinked to double-stranded M13MP18 into human cells. In wild-type cells, this lesion is efficiently repaired, whereas cells deficient in NER can only repair this lesion if an un-damaged homologous donor is co-transfected. Transfected DPC is subject to rapid K63 polyubiquitination. In NER proficient cells, the DPC is subject to K48 polyubiquitination, and is removed via a proteasome-dependent mechanism. In NER-deficient cells, the DNA-conjugated protein is not subject to K48 polyubiquitination. Instead, the K63 tag remains attached, and is only lost when a homologous donor molecule is present. Taken together, these results support a model in which selective addition of polyubiquitin chains to DNA-crosslinked protein leads to selective recruitment of the proteasome and the cellular NER and recombinational DNA repair machinery.


Assuntos
Reparo do DNA , Complexo de Endopeptidases do Proteassoma , Humanos , DNA/química , Dano ao DNA , Complexo de Endopeptidases do Proteassoma/metabolismo , Proteínas/química , Proteínas/metabolismo , Ubiquitina/genética , Ubiquitinação , Transdução de Sinais
5.
N Engl J Med ; 385(7): 585-594, 2021 08 12.
Artigo em Inglês | MEDLINE | ID: mdl-34289274

RESUMO

BACKGROUND: The B.1.617.2 (delta) variant of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus that causes coronavirus disease 2019 (Covid-19), has contributed to a surge in cases in India and has now been detected across the globe, including a notable increase in cases in the United Kingdom. The effectiveness of the BNT162b2 and ChAdOx1 nCoV-19 vaccines against this variant has been unclear. METHODS: We used a test-negative case-control design to estimate the effectiveness of vaccination against symptomatic disease caused by the delta variant or the predominant strain (B.1.1.7, or alpha variant) over the period that the delta variant began circulating. Variants were identified with the use of sequencing and on the basis of the spike (S) gene status. Data on all symptomatic sequenced cases of Covid-19 in England were used to estimate the proportion of cases with either variant according to the patients' vaccination status. RESULTS: Effectiveness after one dose of vaccine (BNT162b2 or ChAdOx1 nCoV-19) was notably lower among persons with the delta variant (30.7%; 95% confidence interval [CI], 25.2 to 35.7) than among those with the alpha variant (48.7%; 95% CI, 45.5 to 51.7); the results were similar for both vaccines. With the BNT162b2 vaccine, the effectiveness of two doses was 93.7% (95% CI, 91.6 to 95.3) among persons with the alpha variant and 88.0% (95% CI, 85.3 to 90.1) among those with the delta variant. With the ChAdOx1 nCoV-19 vaccine, the effectiveness of two doses was 74.5% (95% CI, 68.4 to 79.4) among persons with the alpha variant and 67.0% (95% CI, 61.3 to 71.8) among those with the delta variant. CONCLUSIONS: Only modest differences in vaccine effectiveness were noted with the delta variant as compared with the alpha variant after the receipt of two vaccine doses. Absolute differences in vaccine effectiveness were more marked after the receipt of the first dose. This finding would support efforts to maximize vaccine uptake with two doses among vulnerable populations. (Funded by Public Health England.).


Assuntos
Vacinas contra COVID-19/imunologia , COVID-19/prevenção & controle , Imunogenicidade da Vacina , SARS-CoV-2 , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , COVID-19/epidemiologia , COVID-19/virologia , Estudos de Casos e Controles , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento , Reino Unido/epidemiologia , Potência de Vacina , Adulto Jovem
6.
BMC Public Health ; 24(1): 1175, 2024 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-38671383

RESUMO

INTRODUCTION: The introduction of a national evaluation of newborn screening for Severe Combined Immunodeficiency (SCID) in England triggered a change to the selective Bacillus Calmette-Guerin (BCG) vaccination programme delivery pathway, as this live attenuated vaccine is contraindicated in infants with SCID. The neonatal BCG vaccination programme is a targeted programme for infants at increased risk of tuberculosis and used to be offered shortly after birth. Since September 2021 the BCG vaccine is given to eligible infants within 28 days of birth, when the SCID screening outcome is available. We explore the experiences of those implementing the new pathway, and how they made sense of, engaged with, and appraised the change. METHODS: A mixed-methods evaluation was conducted between October 2022 and February 2023. This involved national online surveys with BCG commissioners and providers and qualitative semi-structured interviews with commissioners, providers, and Child Health Information System stakeholders in two urban areas. Survey data was analysed using descriptive statistics and interview data was analysed thematically. The data was triangulated using Normalization Process Theory as a guiding framework. RESULTS: Survey respondents (n = 65) and qualitative interviewees (n = 16) revealed that making sense of the new pathway was an iterative process. Some expressed a desire for more direction on how to implement the new pathway. The perceived value of the change varied from positive, ambivalent, to concerned. Some felt well-prepared and that improvements to data capture, eligibility screening, and accountably brought by the change were valuable. Others were concerned about the feasibility of the 28-day target, reductions in vaccination coverage, increased resource burden, and the outcome of the SCID evaluation. New collaborations and communities of practice were required to facilitate the change. Three main challenges in implementing the pathway and meeting the 28-day vaccination target were identified: appointment non-attendance; appointment and data systems; and staffing and resourcing. Feedback mechanisms were informal and took place in tandem with implementation. CONCLUSION: The new NHS neonatal BCG service specification has created an effective structure for monitoring and managing the BCG vaccination programme, but further work is required to support delivery of the 28-day vaccination target and improve uptake rates.


Assuntos
Vacina BCG , Programas de Imunização , Humanos , Vacina BCG/administração & dosagem , Inglaterra , Recém-Nascido , Imunodeficiência Combinada Severa , Tuberculose/prevenção & controle , Pesquisa Qualitativa , Avaliação de Programas e Projetos de Saúde , Inquéritos e Questionários , Triagem Neonatal
7.
Brief Bioinform ; 22(4)2021 07 20.
Artigo em Inglês | MEDLINE | ID: mdl-33094325

RESUMO

Sequencing technologies have led to the identification of many variants in the human genome which could act as disease-drivers. As a consequence, a variety of bioinformatics tools have been proposed for predicting which variants may drive disease, and which may be causatively neutral. After briefly reviewing generic tools, we focus on a subset of these methods specifically geared toward predicting which variants in the human cancer genome may act as enablers of unregulated cell proliferation. We consider the resultant view of the cancer genome indicated by these predictors and discuss ways in which these types of prediction tools may be progressed by further research.


Assuntos
Genoma Humano , Genômica , Aprendizado de Máquina , Neoplasias , Software , Biologia Computacional , Humanos , Neoplasias/genética , Neoplasias/metabolismo
8.
PLoS Comput Biol ; 18(6): e1010151, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35671270

RESUMO

The impact of invasion by a single non-native species on the function and structure of ecological communities can be significant, and the effects can become more drastic-and harder to predict-when multiple species invade as a group. Here we modify a dynamic Boolean model of plant-pollinator community assembly to consider the invasion of native communities by multiple invasive species that are selected either randomly or such that the invaders constitute a stable community. We show that, compared to random invasion, whole community invasion leads to final stable communities (where the initial process of species turnover has given way to a static or near-static set of species in the community) including both native and non-native species that are larger, more likely to retain native species, and which experience smaller changes to the topological measures of nestedness and connectance. We consider the relationship between the prevalence of mutualistic interactions among native and invasive species in the final stable communities and demonstrate that mutualistic interactions may act as a buffer against significant disruptions to the native community.


Assuntos
Ecossistema , Espécies Introduzidas , Biota , Plantas , Simbiose
9.
Mycorrhiza ; 33(5-6): 303-319, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37824023

RESUMO

Although ectomycorrhizal (ECM) contribution to soil organic matter processes receives increased attention, little is known about fundamental differences in chemical composition among species, and how that may be affected by carbon (C) availability. Here, we study how 16 species (incl. 19 isolates) grown in pure culture at three different C:N ratios (10:1, 20:1, and 40:1) vary in chemical structure, using Fourier transform infrared (FTIR) spectroscopy. We hypothesized that C availability impacts directly on chemical composition, expecting increased C availability to lead to more carbohydrates and less proteins in the mycelia. There were strong and significant effects of ECM species (R2 = 0.873 and P = 0.001) and large species-specific differences in chemical composition. Chemical composition also changed significantly with C availability, and increased C led to more polysaccharides and less proteins for many species, but not all. Understanding how chemical composition change with altered C availability is a first step towards understanding their role in organic matter accumulation and decomposition.


Assuntos
Micorrizas , Micorrizas/metabolismo , Carbono/metabolismo , Solo/química , Microbiologia do Solo
10.
Hepatology ; 74(1): 428-443, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33420756

RESUMO

BACKGROUND AND AIMS: Liver graft quality is evaluated by visual inspection prior to transplantation, a process highly dependent on the surgeon's experience. We present an objective, noninvasive, quantitative way of assessing liver quality in real time using Raman spectroscopy, a laser-based tool for analyzing biomolecular composition. APPROACH AND RESULTS: A porcine model of donation after circulatory death (DCD) with normothermic regional perfusion (NRP) allowed assessment of liver quality premortem, during warm ischemia (WI) and post-NRP. Ten percent of circulating blood volume was removed in half of experiments to simulate blood recovery for DCD heart removal. Left median lobe biopsies were obtained before circulatory arrest, after 45 minutes of WI, and after 2 hours of NRP and analyzed using spontaneous Raman spectroscopy, stimulated Raman spectroscopy (SRS), and staining. Measurements were also taken in situ from the porcine liver using a handheld Raman spectrometer at these time points from left median and right lateral lobes. Raman microspectroscopy detected congestion during WI by measurement of the intrinsic Raman signal of hemoglobin in red blood cells (RBCs), eliminating the need for exogenous labels. Critically, this microvascular damage was not observed during WI when 10% of circulating blood was removed before cardiac arrest. Two hours of NRP effectively cleared RBCs from congested livers. Intact RBCs were visualized rapidly at high resolution using SRS. Optical properties of ischemic livers were significantly different from preischemic and post-NRP livers as measured using a handheld Raman spectrometer. CONCLUSIONS: Raman spectroscopy is an effective tool for detecting microvascular damage which could assist the decision to use marginal livers for transplantation. Reducing the volume of circulating blood before circulatory arrest in DCD may help reduce microvascular damage.


Assuntos
Seleção do Doador/métodos , Parada Cardíaca/fisiopatologia , Isquemia/diagnóstico , Fígado/irrigação sanguínea , Análise Espectral Raman , Animais , Modelos Animais de Doenças , Estudos de Viabilidade , Humanos , Isquemia/fisiopatologia , Transplante de Fígado , Preservação de Órgãos , Perfusão , Suínos , Isquemia Quente
11.
Matern Child Health J ; 26(7): 1529-1539, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35567701

RESUMO

OBJECTIVE: Screening for social determinants of health (SDH) has been widely adopted to identify child health risks associated with exposure to material hardship. Whereas SDH screening typically addresses a 12-month span, we sought to compare the prevalence of exposure to present (within the past year) as compared to recent (2-4 years ago) hardship among children in the United States. METHODS: We analyzed the 2014 Survey of Income and Program Participation, a nationally representative survey that interviewed participating households annually between 2014 and 2017. We included data from households with children in all waves. As of 2017, households were categorized as (1) experiencing present hardship (within the last year); (2) experiencing recent but not present hardship (any year between 2014 and 2016); and (3) experiencing no hardship over the 4-year period. RESULTS: Of 2422 households, 27% experienced present hardship and 29% experienced recent but not present hardship. Households presently experiencing hardship were more likely to have Medicaid insurance, less likely to be married, and had more children than families who had experienced recent hardship. However, these groups were similar on caregivers' educational attainment, race/ethnicity, language spoken in the home, and age of the youngest child. CONCLUSIONS: Our results suggest that clinical screening tools for SDH that use a 12-month time frame risk missing many children who have recently (within the past 4 years) experienced material hardship and may benefit from interventions to improve social support; a longer time frame could provide clinicians with valuable information for understanding social factors that impact child health and development.


Assuntos
Renda , Pobreza , Cuidadores , Criança , Características da Família , Humanos , Determinantes Sociais da Saúde , Estados Unidos
12.
Proc Natl Acad Sci U S A ; 116(39): 19753-19759, 2019 09 24.
Artigo em Inglês | MEDLINE | ID: mdl-31506353

RESUMO

Hypoxia is a ubiquitous feature of cancers, encouraging glycolytic metabolism, proliferation, and resistance to therapy. Nonetheless, hypoxia is a poorly defined term with confounding features described in the literature. Redox biology provides an important link between the external cellular microenvironment and the cell's response to changing oxygen pressures. In this paper, we demonstrate a correlation between intracellular redox potential (measured using optical nanosensors) and the concentrations of microRNAs (miRNAs) involved in the cell's response to changes in oxygen pressure. The correlations were established using surprisal analysis (an approach derived from thermodynamics and information theory). We found that measured redox potential changes reflect changes in the free energy computed by surprisal analysis of miRNAs. Furthermore, surprisal analysis identified groups of miRNAs, functionally related to changes in proliferation and metastatic potential that played the most significant role in the cell's response to changing oxygen pressure.


Assuntos
Hipóxia Celular/genética , Regulação Neoplásica da Expressão Gênica/genética , MicroRNAs/genética , Hipóxia Celular/fisiologia , Linhagem Celular Tumoral , Citoplasma/metabolismo , Humanos , Hipóxia/metabolismo , Células MCF-7/metabolismo , Oxirredução , Espécies Reativas de Oxigênio , Termodinâmica , Microambiente Tumoral/genética
13.
Emerg Infect Dis ; 27(5): 1468-1471, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33900176

RESUMO

Of the 58,186 coronavirus deaths among adults in England during March-December 2020, 77% occurred in hospitals, 93% were in patients >60 years, and 91% occurred within 28 days of positive specimen. Cumulative mortality rates were highest among persons of Black, Asian, other, or mixed ethnicities and in socioeconomically deprived areas.


Assuntos
COVID-19 , Adulto , Inglaterra/epidemiologia , Humanos , SARS-CoV-2
14.
Anal Chem ; 93(43): 14375-14382, 2021 11 02.
Artigo em Inglês | MEDLINE | ID: mdl-34677947

RESUMO

Cocrystals are important molecular adducts that have many advantages as a means of modifying the physicochemical properties of active pharmaceutical ingredients, including taste masking and improved solubility, bioavailability, and stability. As a result, the discovery of new cocrystals is of great interest to commercial drug discovery programs. Time-consuming manual analysis of the large volumes of data that emerge from large-scale cocrystal screening programs of up to 1000s of preparations poses a challenge. Raman spectroscopy has been shown to discriminate between cocrystals and physical mixtures and is easy to automate, allowing rapid screening of large numbers of potential cocrystals, but the spectral features that encode the information are often subtle (e.g., slight changes in peak positions or intensities). We have employed an automated signal processing routine based on a sparse decomposition algorithm to speed up the data processing steps while maintaining the accuracy of a trained spectroscopist. We used our algorithm to screen 31 potential cocrystal preparations and found that through the use of a computationally generated threshold, we could achieve a clear classification of cocrystals and physical mixtures in less than a minute, compared to several hours manually.


Assuntos
Preparações Farmacêuticas , Análise Espectral Raman , Disponibilidade Biológica , Cristalização , Solubilidade
15.
Anal Chem ; 93(41): 13844-13851, 2021 10 19.
Artigo em Inglês | MEDLINE | ID: mdl-34609126

RESUMO

Extracellular pH (pHe) is an important chemical factor in many cellular processes and disease pathologies. The routine sampling of pHe in vitro could lead to innovative advances in therapeutics. To this end, we have fabricated a novel gold-coated polymer mesh, which facilitates the real-time measurement of pHe via surface-enhanced Raman scattering (SERS). In this proof of concept study, we apply our SERS sensor to measure metabolically induced changes in the pHe of carcinoma-derived cell line HepG2/C3A. We demonstrate that gold-coated polyurethane electrospun nanofibers (AuNF) have strong and reproducible SERS spectra of surface-adsorbed analytes. By functionalizing AuNF with pH-responsive reporter 4-mercaptobenzoic acid (MBA), we have developed an accurate pH SERS sensor for the extracellular microenvironment. We cultured HepG2/C3A on the surface of MBA-AuNF and measured an acidic shift in pHe at the cell-fiber interface. Following exposure to staurosporine, an apoptosis-inducing drug, we observed changes in the HepG2/C3A cellular morphology indicative of controlled cell death, and detected an increase in the pHe of HepG2/C3A. These results demonstrate how subtle changes in pHe, induced by the metabolic activity of cells, can be measured with our novel SERS sensor MBA-AuNF. The excellent pH measurement performance of MBA-AuNF provides a unique platform to study extracellular pH on the microscale and will help to deepen our understanding of pHe in disease pathology.


Assuntos
Nanopartículas Metálicas , Microambiente Celular , Concentração de Íons de Hidrogênio , Nanopartículas Metálicas/toxicidade , Polímeros , Análise Espectral Raman , Telas Cirúrgicas
16.
Bioinformatics ; 36(12): 3637-3644, 2020 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-32282885

RESUMO

MOTIVATION: Next-generation sequencing technologies have accelerated the discovery of single nucleotide variants in the human genome, stimulating the development of predictors for classifying which of these variants are likely functional in disease, and which neutral. Recently, we proposed CScape, a method for discriminating between cancer driver mutations and presumed benign variants. For the neutral class, this method relied on benign germline variants found in the 1000 Genomes Project database. Discrimination could, therefore, be influenced by the distinction of germline versus somatic, rather than neutral versus disease driver. This motivates this article in which we consider predictive discrimination between recurrent and rare somatic single point mutations based solely on using cancer data, and the distinction between these two somatic classes and germline single point mutations. RESULTS: For somatic point mutations in coding and non-coding regions of the genome, we propose CScape-somatic, an integrative classifier for predictively discriminating between recurrent and rare variants in the human cancer genome. In this study, we use purely cancer genome data and investigate the distinction between minimal occurrence and significantly recurrent somatic single point mutations in the human cancer genome. We show that this type of predictive distinction can give novel insight, and may deliver more meaningful prediction in both coding and non-coding regions of the cancer genome. Tested on somatic mutations, CScape-somatic outperforms alternative methods, reaching 74% balanced accuracy in coding regions and 69% in non-coding regions, whereas even higher accuracy may be achieved using thresholds to isolate high-confidence predictions. AVAILABILITY AND IMPLEMENTATION: Predictions and software are available at http://CScape-somatic.biocompute.org.uk/. CONTACT: mark.f.rogers.phd@gmail.com or C.Campbell@bristol.ac.uk. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.


Assuntos
Neoplasias , Mutação Puntual , Genoma Humano/genética , Genômica , Humanos , Mutação , Neoplasias/genética , Software
17.
Opt Lett ; 46(17): 4104-4107, 2021 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-34469950

RESUMO

Significant improvements in time-correlated single photon counting (TCSPC) Raman spectroscopy acquisition times can be achieved through exploitation of megahertz (MHz) laser repetition rates. We have developed a TCSPC Raman spectroscopy system based on a high peak power (>40W) pulsed laser, a high pulse repetition rate (40 MHz), a custom f/1.5 spectrometer, and a 512 spectral channel × 16 time bin single photon avalanche diode line sensor. We report millisecond Raman spectrum acquisition times, a peak Raman count rate of 104 kcps, and a linewidth aggregated count rate of 440 kcps with a diamond sample. This represents a three-order-of-magnitude increase in measured Raman count rate in comparison with a 104 kHz pulsed laser operating at 300 W and a four-order-of-magnitude increase over a 0.1 W pulsed laser operating at 40 MHz. A Raman-to-fluorescence ratio of 4.76 is achieved with a sesame oil sample at a 20 MHz repetition rate. Achieving high count rates and Raman-to-fluorescence ratios unlocks the potential of combined Raman/fluorescence lifetime spectroscopy for imaging and other short acquisition time applications.

18.
PLoS Comput Biol ; 16(3): e1007687, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32218567

RESUMO

Tuberculosis (TB) remains a public health threat in low TB incidence countries, through a combination of reactivated disease and onward transmission. Using surveillance data from the United Kingdom (UK) and the Netherlands (NL), we demonstrate a simple and predictable relationship between the probability of observing a cluster and its size (the number of cases with a single genotype). We demonstrate that the full range of observed cluster sizes can be described using a modified branching process model with the individual reproduction number following a Poisson lognormal distribution. We estimate that, on average, between 2010 and 2015, a TB case generated 0.41 (95% CrI 0.30,0.60) secondary cases in the UK, and 0.24 (0.14,0.48) secondary cases in the NL. A majority of cases did not generate any secondary cases. Recent transmission accounted for 39% (26%,60%) of UK cases and 23%(13%,37%) of NL cases. We predict that reducing UK transmission rates to those observed in the NL would result in 538(266,818) fewer cases annually in the UK. In conclusion, while TB in low incidence countries is strongly associated with reactivated infections, we demonstrate that recent transmission remains sufficient to warrant policies aimed at limiting local TB spread.


Assuntos
Modelos Biológicos , Tuberculose , Biologia Computacional , Epidemiologia , Humanos , Incidência , Mycobacterium tuberculosis/genética , Países Baixos/epidemiologia , Tuberculose/epidemiologia , Tuberculose/transmissão , Reino Unido/epidemiologia
19.
J Asthma ; 58(12): 1616-1622, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-32878515

RESUMO

OBJECTIVE: Housing insecurity is an important socioeconomic factor that may impact emergency department (ED) use for children with asthma, but housing insecurity screening has primarily relied on patient surveys or linkage to external data sources. Using patient addresses recorded in the electronic medical record (EMR), we sought to correlate recent changes in address (as a proxy for housing insecurity) with ED revisit risk. METHODS: We retrospectively identified patients age 2-17 years seen in our rural ED for asthma exacerbation during 2016-2018. We used EMR data from the 12 months before the earliest ED visit to compare patients with and without a recent change of address (over previous 12 months) on 30- and 90-day all-cause and asthma-specific ED revisits. RESULTS: The study included 632 children, of whom 85 (13%) had a recent address change before the index ED visit. Moving was not associated with asthma-specific 30-day or 90-day revisits. Ninety-day all-cause revisits were more common among patients who had recently moved (36% vs. 25%; p = 0.019), although this difference was not statistically significant after multivariable adjustment for Medicaid insurance coverage and number of recent health system encounters (odds ratio: 1.49; 95% confidence interval: 0.91, 2.46; p = 0.114). CONCLUSIONS: A history of recent address change in the EMR was not independently associated with repeat ED visits for asthma exacerbation. Many children presenting to the ED did not have recent encounters with our health system where address could be ascertained. This EMR-based proxy for housing insecurity may be more applicable to patients under continuous follow-up.


Assuntos
Asma/epidemiologia , Serviço Hospitalar de Emergência/estatística & dados numéricos , Instabilidade Habitacional , Adolescente , Criança , Pré-Escolar , Registros Eletrônicos de Saúde , Feminino , Humanos , Masculino , Medicaid/estatística & dados numéricos , Adesão à Medicação , Readmissão do Paciente , Estudos Retrospectivos , População Rural , Fatores Sociodemográficos , Estados Unidos
20.
Am J Respir Crit Care Med ; 201(8): 984-991, 2020 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-31825645

RESUMO

Rationale: Development of diagnostic tools with improved predictive value for tuberculosis (TB) is a global research priority.Objectives: We evaluated whether implementing higher diagnostic thresholds than currently recommended for QuantiFERON Gold-in-Tube (QFT-GIT), T-SPOT.TB, and the tuberculin skin test (TST) might improve prediction of incident TB.Methods: Follow-up of a UK cohort of 9,610 adult TB contacts and recent migrants was extended by relinkage to national TB surveillance records (median follow-up 4.7 yr). Incidence rates and rate ratios, sensitivities, specificities, and predictive values for incident TB were calculated according to ordinal strata for quantitative results of QFT-GIT, T-SPOT.TB, and TST (with adjustment for prior bacillus Calmette-Guérin [BCG] vaccination).Measurements and Main Results: For all tests, incidence rates and rate ratios increased with the magnitude of the test result (P < 0.0001). Over 3 years' follow-up, there was a modest increase in positive predictive value with the higher thresholds (3.0% for QFT-GIT ≥0.35 IU/ml vs. 3.6% for ≥4.00 IU/ml; 3.4% for T-SPOT.TB ≥5 spots vs. 5.0% for ≥50 spots; and 3.1% for BCG-adjusted TST ≥5 mm vs. 4.3% for ≥15 mm). As thresholds increased, sensitivity to detect incident TB waned for all tests (61.0% for QFT-GIT ≥0.35 IU/ml vs. 23.2% for ≥4.00 IU/ml; 65.4% for T-SPOT.TB ≥5 spots vs. 27.2% for ≥50 spots; 69.7% for BCG-adjusted TST ≥5 mm vs. 28.1% for ≥15 mm).Conclusions: Implementation of higher thresholds for QFT-GIT, T-SPOT.TB, and TST modestly increases positive predictive value for incident TB, but markedly reduces sensitivity. Novel biomarkers or validated multivariable risk algorithms are required to improve prediction of incident TB.


Assuntos
Testes de Liberação de Interferon-gama/métodos , Tuberculose Latente/diagnóstico , Teste Tuberculínico/métodos , Tuberculose/diagnóstico , Adulto , Estudos de Coortes , Feminino , Humanos , Incidência , Tuberculose Latente/epidemiologia , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Estudos Prospectivos , Tuberculose/epidemiologia , Reino Unido/epidemiologia
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