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1.
Emerg Infect Dis ; 30(3): 530-538, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38407144

RESUMO

Persons living in long-term care facilities (LTCFs) were disproportionately affected by COVID-19. We used wastewater surveillance to detect SARS-CoV-2 infection in this setting by collecting and testing 24-hour composite wastewater samples 2-4 times weekly at 6 LTCFs in Kentucky, USA, during March 2021-February 2022. The LTCFs routinely tested staff and symptomatic and exposed residents for SARS-CoV-2 using rapid antigen tests. Of 780 wastewater samples analyzed, 22% (n = 173) had detectable SARS-CoV-2 RNA. The LTCFs reported 161 positive (of 16,905) SARS-CoV-2 clinical tests. The wastewater SARS-CoV-2 signal showed variable correlation with clinical test data; we observed the strongest correlations in the LTCFs with the most positive clinical tests (n = 45 and n = 58). Wastewater surveillance was 48% sensitive and 80% specific in identifying SARS-CoV-2 infections found on clinical testing, which was limited by frequency, coverage, and rapid antigen test performance.


Assuntos
COVID-19 , Águas Residuárias , Humanos , Kentucky/epidemiologia , Vigilância Epidemiológica Baseada em Águas Residuárias , Assistência de Longa Duração , RNA Viral , COVID-19/diagnóstico , COVID-19/epidemiologia , SARS-CoV-2
2.
N Engl J Med ; 385(9): 790-802, 2021 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-34351721

RESUMO

BACKGROUND: Thrombosis and inflammation may contribute to the risk of death and complications among patients with coronavirus disease 2019 (Covid-19). We hypothesized that therapeutic-dose anticoagulation may improve outcomes in noncritically ill patients who are hospitalized with Covid-19. METHODS: In this open-label, adaptive, multiplatform, controlled trial, we randomly assigned patients who were hospitalized with Covid-19 and who were not critically ill (which was defined as an absence of critical care-level organ support at enrollment) to receive pragmatically defined regimens of either therapeutic-dose anticoagulation with heparin or usual-care pharmacologic thromboprophylaxis. The primary outcome was organ support-free days, evaluated on an ordinal scale that combined in-hospital death (assigned a value of -1) and the number of days free of cardiovascular or respiratory organ support up to day 21 among patients who survived to hospital discharge. This outcome was evaluated with the use of a Bayesian statistical model for all patients and according to the baseline d-dimer level. RESULTS: The trial was stopped when prespecified criteria for the superiority of therapeutic-dose anticoagulation were met. Among 2219 patients in the final analysis, the probability that therapeutic-dose anticoagulation increased organ support-free days as compared with usual-care thromboprophylaxis was 98.6% (adjusted odds ratio, 1.27; 95% credible interval, 1.03 to 1.58). The adjusted absolute between-group difference in survival until hospital discharge without organ support favoring therapeutic-dose anticoagulation was 4.0 percentage points (95% credible interval, 0.5 to 7.2). The final probability of the superiority of therapeutic-dose anticoagulation over usual-care thromboprophylaxis was 97.3% in the high d-dimer cohort, 92.9% in the low d-dimer cohort, and 97.3% in the unknown d-dimer cohort. Major bleeding occurred in 1.9% of the patients receiving therapeutic-dose anticoagulation and in 0.9% of those receiving thromboprophylaxis. CONCLUSIONS: In noncritically ill patients with Covid-19, an initial strategy of therapeutic-dose anticoagulation with heparin increased the probability of survival to hospital discharge with reduced use of cardiovascular or respiratory organ support as compared with usual-care thromboprophylaxis. (ATTACC, ACTIV-4a, and REMAP-CAP ClinicalTrials.gov numbers, NCT04372589, NCT04505774, NCT04359277, and NCT02735707.).


Assuntos
Anticoagulantes/administração & dosagem , Tratamento Farmacológico da COVID-19 , Heparina/administração & dosagem , Trombose/prevenção & controle , Adulto , Idoso , Anticoagulantes/efeitos adversos , Anticoagulantes/uso terapêutico , COVID-19/mortalidade , Feminino , Hemorragia/induzido quimicamente , Heparina/efeitos adversos , Heparina/uso terapêutico , Heparina de Baixo Peso Molecular/uso terapêutico , Mortalidade Hospitalar , Humanos , Masculino , Pessoa de Meia-Idade , Análise de Sobrevida
3.
Pharm Stat ; 2024 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-38676420

RESUMO

Inferentially seamless 2/3 designs are increasingly popular in clinical trials. It is important to understand their relative advantages compared with separate phase 2 and phase 3 trials, and to understand the consequences of design choices such as the proportion of patients included in the phase 2 portion of the design. Extending previous work in this area, we perform a simulation study across multiple numbers of arms and efficacy response curves. We consider a design space crossing the choice of a separate versus seamless design with the choice of allocating 0%-100% of available patients in phase 2, with the remainder in phase 3. The seamless designs achieve greater power than their separate trial counterparts. Importantly, the optimal seamless design is more robust than the optimal separate program, meaning that one range of values for the proportion of patients used in phase 2 (30%-50% of the total phase 2/3 sample size) is nearly optimal for a wide range of response scenarios. In contrast, a percentage of patients used in phase 2 for separate trials may be optimal for some alternative scenarios but decidedly inferior for other alternative scenarios. When operationally and scientifically viable, seamless trials provide superior performance compared with separate phase 2 and phase 3 trials. The results also provide guidance for the implementation of these trials in practice.

4.
J Biol Chem ; 298(3): 101649, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35104504

RESUMO

RNA-binding proteins (RBPs) regulate the expression of large cohorts of RNA species to produce programmatic changes in cellular phenotypes. To describe the function of RBPs within a cell, it is key to identify their mRNA-binding partners. This is often done by crosslinking nucleic acids to RBPs, followed by chemical release of the nucleic acid fragments for analysis. However, this methodology is lengthy, which involves complex processing with attendant sample losses, thus large amounts of starting materials and prone to artifacts. To evaluate potential alternative technologies, we tested "exclusion-based" purification of immunoprecipitates (IFAST or SLIDE) and report here that these methods can efficiently, rapidly, and specifically isolate RBP-RNA complexes. The analysis requires less than 1% of the starting material required for techniques that include crosslinking. Depending on the antibody used, 50% to 100% starting protein can be retrieved, facilitating the assay of endogenous levels of RBPs; the isolated ribonucleoproteins are subsequently analyzed using standard techniques, to provide a comprehensive portrait of RBP complexes. Using exclusion-based techniques, we show that the mRNA-binding partners for RBP IGF2BP1 in cultured mammary epithelial cells are enriched in mRNAs important for detoxifying superoxides (specifically glutathione peroxidase [GPX]-1 and GPX-2) and mRNAs encoding mitochondrial proteins. We show that these interactions are functionally significant, as loss of function of IGF2BP1 leads to destabilization of GPX mRNAs and reduces mitochondrial membrane potential and oxygen consumption. We speculate that this underlies a consistent requirement for IGF2BP1 for the expression of clonogenic activity in vitro.


Assuntos
Glândulas Mamárias Animais , Glândulas Mamárias Humanas , Proteínas de Ligação a RNA , Animais , Células Epiteliais/metabolismo , Feminino , Humanos , Imunoprecipitação , Glândulas Mamárias Animais/citologia , Glândulas Mamárias Animais/metabolismo , Glândulas Mamárias Humanas/citologia , Glândulas Mamárias Humanas/metabolismo , RNA/metabolismo , RNA Mensageiro , Proteínas de Ligação a RNA/metabolismo
5.
Clin Trials ; 19(5): 490-501, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35993547

RESUMO

BACKGROUND: Multi-arm platform trials investigate multiple agents simultaneously, typically with staggered entry and exit of experimental treatment arms versus a shared control arm. In such settings, there is considerable debate whether to limit analyses for a treatment arm to concurrent randomized control subjects or to allow comparisons to both concurrent and non-concurrent (pooled) control subjects. The potential bias from temporal drift over time is at the core of this debate. METHODS: We propose time-adjusted analyses, including a "Bayesian Time Machine," to model potential temporal drift in the entire study population, such that primary analyses can incorporate all randomized control subjects from the platform trial. We conduct a simulation study to assess performance relative to utilizing concurrent or pooled controls. RESULTS: In multi-arm platform trials with staggered entry, analyses adjusting for temporal drift (either Bayesian or frequentist) have superior estimation of treatment effects and favorable testing properties compared to analyses using either concurrent or pooled controls. The Bayesian Time Machine generally provides estimates with greater precision and smaller mean square error than alternative approaches, at the risk of small bias and small Type I error inflation. CONCLUSIONS: The Bayesian Time Machine provides a compromise between bias and precision by smoothing estimates across time and leveraging all available data for the estimation of treatment effects. Prior distributions controlling the behavior of dynamic smoothing across time must be pre-specified and carefully calibrated to the unique context of each trial, appropriately accounting for the population, disease, and endpoints.


Assuntos
Projetos de Pesquisa , Teorema de Bayes , Viés , Protocolos Clínicos , Simulação por Computador , Humanos
6.
Genet Med ; 23(11): 2067-2075, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34257421

RESUMO

PURPOSE: To evaluate the safety and efficacy of N-acetylmannosamine (ManNAc) in GNE myopathy, a genetic muscle disease caused by deficiency of the rate-limiting enzyme in N-acetylneuraminic acid (Neu5Ac) biosynthesis. METHODS: We conducted an open-label, phase 2, single-center (NIH, USA) study to evaluate oral ManNAc in 12 patients with GNE myopathy (ClinicalTrials.gov NCT02346461). Primary endpoints were safety and biochemical efficacy as determined by change in plasma Neu5Ac and sarcolemmal sialylation. Clinical efficacy was evaluated using secondary outcome measures as part of study extensions, and a disease progression model (GNE-DPM) was tested as an efficacy analysis method. RESULTS: Most drug-related adverse events were gastrointestinal, and there were no serious adverse events. Increased plasma Neu5Ac (+2,159 nmol/L, p < 0.0001) and sarcolemmal sialylation (p = 0.0090) were observed at day 90 compared to baseline. A slower rate of decline was observed for upper extremity strength (p = 0.0139), lower extremity strength (p = 0.0006), and the Adult Myopathy Assessment Tool (p = 0.0453), compared to natural history. Decreased disease progression was estimated at 12 (γ = 0.61 [95% CI: 0.09, 1.27]) and 18 months (γ = 0.55 [95% CI: 0.12, 1.02]) using the GNE-DPM. CONCLUSION: ManNAc showed long-term safety, biochemical efficacy consistent with the intended mechanism of action, and preliminary evidence clinical efficacy in patients with GNE myopathy.


Assuntos
Miopatias Distais , Doenças Musculares , Adulto , Hexosaminas , Humanos , Doenças Musculares/induzido quimicamente , Doenças Musculares/tratamento farmacológico , Doenças Musculares/genética , Ácido N-Acetilneuramínico
7.
Stat Med ; 40(19): 4167-4184, 2021 08 30.
Artigo em Inglês | MEDLINE | ID: mdl-33960507

RESUMO

A Bayesian adaptive design is proposed for a clinical trial in Duchenne muscular dystrophy. The trial was designed to demonstrate treatment efficacy on an ambulatory-based clinical endpoint and to identify early success on a biomarker (dystrophin protein levels) that can serve as a basis for accelerated approval in the United States. The trial incorporates placebo augmentation using placebo data from past clinical trials. A thorough simulation study was conducted to understand the operating characteristics of the trial. This trial design was selected for the US FDA Complex Innovative Trial Design Pilot Meeting Program and the experience in that program is summarized.


Assuntos
Distrofia Muscular de Duchenne , Teorema de Bayes , Distrofina , Humanos , Distrofia Muscular de Duchenne/tratamento farmacológico , Projetos de Pesquisa , Resultado do Tratamento
8.
Clin Trials ; 17(5): 491-500, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32815416

RESUMO

BACKGROUND: Mortality from COVID-19 is high among hospitalized patients and effective therapeutics are lacking. Hypercoagulability, thrombosis and hyperinflammation occur in COVID-19 and may contribute to severe complications. Therapeutic anticoagulation may improve clinical outcomes through anti-thrombotic, anti-inflammatory and anti-viral mechanisms. Our primary objective is to evaluate whether therapeutic-dose anticoagulation with low-molecular-weight heparin or unfractionated heparin prevents mechanical ventilation and/or death in patients hospitalized with COVID-19 compared to usual care. METHODS: An international, open-label, adaptive randomized controlled trial. Using a Bayesian framework, the trial will declare results as soon as pre-specified posterior probabilities for superiority, futility, or harm are reached. The trial uses response-adaptive randomization to maximize the probability that patients will receive the more beneficial treatment approach, as treatment effect information accumulates within the trial. By leveraging a common data safety monitoring board and pooling data with a second similar international Bayesian adaptive trial (REMAP-COVID anticoagulation domain), treatment efficacy and safety will be evaluated as efficiently as possible. The primary outcome is an ordinal endpoint with three possible outcomes based on the worst status of each patient through day 30: no requirement for invasive mechanical ventilation, invasive mechanical ventilation or death. CONCLUSION: Using an adaptive trial design, the Anti-Thrombotic Therapy To Ameliorate Complications of COVID-19 trial will establish whether therapeutic anticoagulation can reduce mortality and/or avoid the need for mechanical ventilation in patients hospitalized with COVID-19. Leveraging existing networks to recruit sites will increase enrollment and mitigate enrollment risk in sites with declining COVID-19 cases.


Assuntos
Antivirais/uso terapêutico , Betacoronavirus , Infecções por Coronavirus/tratamento farmacológico , Heparina/administração & dosagem , Pneumonia Viral/tratamento farmacológico , Trombose/prevenção & controle , Adolescente , Adulto , Anticoagulantes/administração & dosagem , COVID-19 , Infecções por Coronavirus/complicações , Infecções por Coronavirus/epidemiologia , Relação Dose-Resposta a Droga , Feminino , Humanos , Masculino , Pandemias , Pneumonia Viral/complicações , Pneumonia Viral/epidemiologia , SARS-CoV-2 , Trombose/etiologia , Resultado do Tratamento , Adulto Jovem
9.
Anal Chem ; 91(18): 11848-11855, 2019 09 17.
Artigo em Inglês | MEDLINE | ID: mdl-31411020

RESUMO

The extraction of bioanalytes is the first step in many diagnostic and analytical assays. However, most bioanalyte extraction methods require extensive dilution-based washing processes that are not only time-consuming and laborious but can also result in significant sample loss, limiting their applications in rare sample analyses. Here, we present a method that enables the efficient extraction of multiple different bioanalytes from rare samples (down to 10 cells) without washing-centrifugation-assisted immiscible fluid filtration (CIFF). CIFF utilizes centrifugal force to drive the movement of analyte-bound glass microbeads from an aqueous sample into an immiscible hydrophobic solution to perform an efficient, simple, and nondilutive extraction. The method can be performed using conventional polymerase chain reaction (PCR) tubes with no requirement of specialized devices, columns, or instruments, making it broadly accessible and cost-effective. The CIFF process can effectively remove approximately 99.5% of the aqueous sample in one extraction with only 0.5% residual carryover, whereas a traditional "spin-down and aspirate" operation results in a higher 3.6% carryover. Another unique aspect of CIFF is its ability to perform two different solid-phase bioanalytes extractions simultaneously within a single vessel without fractionating the sample or performing serial extractions. Here we demonstrate efficient mRNA and DNA extraction from low-input samples (down to 10 cells) with slightly higher to comparable recovery compared to a traditional column-based extraction technique and the simultaneous extraction of two different proteins in the same tube using CIFF.


Assuntos
Centrifugação/métodos , Fracionamento Químico/métodos , DNA/isolamento & purificação , Filtração/métodos , RNA Mensageiro/isolamento & purificação , Fracionamento Químico/instrumentação , Humanos , Reação em Cadeia da Polimerase/instrumentação , Proteínas/isolamento & purificação , Propriedades de Superfície , Células THP-1
10.
Stat Med ; 38(17): 3123-3138, 2019 07 30.
Artigo em Inglês | MEDLINE | ID: mdl-31070807

RESUMO

A primary goal of a phase II dose-ranging trial is to identify a correct dose before moving forward to a phase III confirmatory trial. A correct dose is one that is actually better than control. A popular model in phase II is an independent model that puts no structure on the dose-response relationship. Unfortunately, the independent model does not efficiently use information from related doses. One very successful alternate model improves power using a pre-specified dose-response structure. Past research indicates that EMAX models are broadly successful and therefore attractive for designing dose-response trials. However, there may be instances of slight risk of nonmonotone trends that need to be addressed when planning a clinical trial design. We propose to add hierarchical parameters to the EMAX model. The added layer allows information about the treatment effect in one dose to be "borrowed" when estimating the treatment effect in another dose. This is referred to as the hierarchical EMAX model. Our paper compares three different models (independent, EMAX, and hierarchical EMAX) and two different design strategies. The first design considered is Bayesian with a fixed trial design, and it has a fixed schedule for randomization. The second design is Bayesian but adaptive, and it uses response adaptive randomization. In this article, a randomized trial of patients with severe traumatic brain injury is provided as a motivating example.


Assuntos
Ensaios Clínicos Fase II como Assunto , Relação Dose-Resposta a Droga , Oxigenoterapia Hiperbárica , Modelos Estatísticos , Ensaios Clínicos Controlados Aleatórios como Assunto , Projetos de Pesquisa , Teorema de Bayes , Humanos , Estudos Multicêntricos como Assunto , Estudos Prospectivos
11.
JAMA ; 322(15): 1476-1485, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31577035

RESUMO

IMPORTANCE: Norepinephrine, the first-line vasopressor for septic shock, is not always effective and has important catecholaminergic adverse effects. Selepressin, a selective vasopressin V1a receptor agonist, is a noncatecholaminergic vasopressor that may mitigate sepsis-induced vasodilatation, vascular leakage, and edema, with fewer adverse effects. OBJECTIVE: To test whether selepressin improves outcome in septic shock. DESIGN, SETTING, AND PARTICIPANTS: An adaptive phase 2b/3 randomized clinical trial comprising 2 parts that included adult patients (n = 868) with septic shock requiring more than 5 µg/min of norepinephrine. Part 1 used a Bayesian algorithm to adjust randomization probabilities to alternative selepressin dosing regimens and to trigger transition to part 2, which would compare the best-performing regimen with placebo. The trial was conducted between July 2015 and August 2017 in 63 hospitals in Belgium, Denmark, France, the Netherlands, and the United States, and follow-up was completed by May 2018. INTERVENTIONS: Random assignment to 1 of 3 dosing regimens of selepressin (starting infusion rates of 1.7, 2.5, and 3.5 ng/kg/min; n = 585) or to placebo (n = 283), all administered as continuous infusions titrated according to hemodynamic parameters. MAIN OUTCOMES AND MEASURES: Primary end point was ventilator- and vasopressor-free days within 30 days (deaths assigned zero days) of commencing study drug. Key secondary end points were 90-day mortality, kidney replacement therapy-free days, and ICU-free days. RESULTS: Among 868 randomized patients, 828 received study drug (mean age, 66.3 years; 341 [41.2%] women) and comprised the primary analysis cohort, of whom 562 received 1 of 3 selepressin regimens, 266 received placebo, and 817 (98.7%) completed the trial. The trial was stopped for futility at the end of part 1. Median study drug duration was 37.8 hours (IQR, 17.8-72.4). There were no significant differences in the primary end point (ventilator- and vasopressor-free days: 15.0 vs 14.5 in the selepressin and placebo groups; difference, 0.6 [95% CI, -1.3 to 2.4]; P = .30) or key secondary end points (90-day mortality, 40.6% vs 39.4%; difference, 1.1% [95% CI, -6.5% to 8.8%]; P = .77; kidney replacement therapy-free days: 18.5 vs 18.2; difference, 0.3 [95% CI, -2.1 to 2.6]; P = .85; ICU-free days: 12.6 vs 12.2; difference, 0.5 [95% CI, -1.2 to 2.2]; P = .41). Adverse event rates included cardiac arrhythmias (27.9% vs 25.2% of patients), cardiac ischemia (6.6% vs 5.6%), mesenteric ischemia (3.2% vs 2.6%), and peripheral ischemia (2.3% vs 2.3%). CONCLUSIONS AND RELEVANCE: Among patients with septic shock receiving norepinephrine, administration of selepressin, compared with placebo, did not result in improvement in vasopressor- and ventilator-free days within 30 days. Further research would be needed to evaluate the potential role of selepressin for other patient-centered outcomes in septic shock. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02508649.

12.
Mol Carcinog ; 57(4): 559-566, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29350431

RESUMO

MicroRNAs (miRNAs), small 22-25 nucleotide non-coding RNAs, play important roles in cellular and tumor biology. However, characterizing miRNA function remains challenging due to an abundance of predicted targets and an experimental bottleneck in identifying biologically relevant direct targets. Here, we developed a novel technique (miFAST) to identify direct miRNA target genes. Using miFAST, we confirmed several previously reported miR-340 target genes and identified five additional novel direct miR-340 targets in melanoma cells. This methodology can also be efficiently applied for the global characterization of miRNA targets. Utilizing miFAST to characterize direct miRNA targetomes will further our understanding of miRNA biology and function.


Assuntos
Perfilação da Expressão Gênica/métodos , Regulação Neoplásica da Expressão Gênica , MicroRNAs/genética , Biologia Molecular/métodos , Linhagem Celular Tumoral , Perfilação da Expressão Gênica/instrumentação , Humanos , Biologia Molecular/instrumentação , Reprodutibilidade dos Testes
14.
J Biopharm Stat ; 27(4): 659-672, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-27295566

RESUMO

Balanced two-arm designs are more powerful than unbalanced designs and, consequently, Bayesian adaptive designs (BADs) are less powerful. However, when considering other subject- or community-focused design characteristics, fixed two-arm designs can be suboptimal. We use a novel approach to identify the best two-arm study design, taking into consideration both the statistical perspective and the community's perception. Data envelopment analysis (DEA) was used to estimate the relative performance of competing designs in the presence of multiple optimality criteria. The two-arm fixed design has enough deficiencies in subject- and community-specific benefit to make it the least favorable study design.


Assuntos
Interpretação Estatística de Dados , Ensaios Clínicos Controlados Aleatórios como Assunto , Projetos de Pesquisa , Teorema de Bayes , Humanos
15.
Pharm Stat ; 16(3): 210-217, 2017 05.
Artigo em Inglês | MEDLINE | ID: mdl-28261972

RESUMO

Response adaptive randomization (RAR) methods for clinical trials are susceptible to imbalance in the distribution of influential covariates across treatment arms. This can make the interpretation of trial results difficult, because observed differences between treatment groups may be a function of the covariates and not necessarily because of the treatments themselves. We propose a method for balancing the distribution of covariate strata across treatment arms within RAR. The method uses odds ratios to modify global RAR probabilities to obtain stratum-specific modified RAR probabilities. We provide illustrative examples and a simple simulation study to demonstrate the effectiveness of the strategy for maintaining covariate balance. The proposed method is straightforward to implement and applicable to any type of RAR method or outcome.


Assuntos
Ensaios Clínicos Controlados Aleatórios como Assunto , Protocolos Clínicos , Simulação por Computador , Probabilidade , Distribuição Aleatória
16.
Anal Chem ; 88(20): 9902-9907, 2016 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-27598856

RESUMO

The simple, rapid magnetic manipulation of paramagnetic particles (PMPs) paired with the wide range of available surface chemistries has strongly positioned PMPs in the field of analyte isolation. One recent technology, sliding lid for immobilized droplet extractions (SLIDE), presents a simple, rapid alternative to traditional PMP isolation protocols. Rather than remove fluid from PMP-bound analyte, SLIDE directly removes the PMPs from the fluid. SLIDE collects the PMPs on a hydrophobic, removable surface, which allows PMPs to be captured from one well and then transferred and released into a second well. Despite several key advantages, SLIDE remains limited by its passive magnetic manipulation that only allows for a one-time capture-and-release of PMPs, preventing wash steps and limiting purity. Furthermore, the strategy employed by SLIDE constrains the position of the wells, thereby limiting throughput and integration into automated systems. Here, we introduce a new, mechanically and operationally simplistic magnetic manipulation system for integration with the SLIDE technology to overcome the previously stated limitations. This magnetic system is compatible with nearly any plate design, can be integrated into automated workflows, enables high-throughput formats, simplifies mechanical requirements, and is amenable to a range of analytes. Using this magnetic system, PMPs can be collected, released, and resuspended throughout multiple wells regardless of proximity. We demonstrate this system's capabilities to isolate whole cells, mRNA, and DNA, demonstrating up to a 28-fold improvement of purity via the multiwash protocols enabled by this magnetic technology.

17.
Biomed Microdevices ; 18(4): 70, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-27432323

RESUMO

Heterotypic interactions in cancer microenvironments play important roles in disease initiation, progression, and spread. Co-culture is the predominant approach used in dissecting paracrine interactions between tumor and stromal cells, but functional results from simple co-cultures frequently fail to correlate to in vivo conditions. Though complex heterotypic in vitro models have improved functional relevance, there is little systematic knowledge of how multi-culture parameters influence this recapitulation. We therefore have employed a more iterative approach to investigate the influence of increasing model complexity; increased heterotypic complexity specifically. Here we describe how the compartmentalized and microscale elements of our multi-culture device allowed us to obtain gene expression data from one cell type at a time in a heterotypic culture where cells communicated through paracrine interactions. With our device we generated a large dataset comprised of cell type specific gene-expression patterns for cultures of increasing complexity (three cell types in mono-, co-, or tri-culture) not readily accessible in other systems. Principal component analysis indicated that gene expression was changed in co-culture but was often more strongly altered in tri-culture as compared to mono-culture. Our analysis revealed that cell type identity and the complexity around it (mono-, co-, or tri-culture) influence gene regulation. We also observed evidence of complementary regulation between cell types in the same heterotypic culture. Here we demonstrate the utility of our platform in providing insight into how tumor and stromal cells respond to microenvironments of varying complexities highlighting the expanding importance of heterotypic cultures that go beyond conventional co-culture.


Assuntos
Neoplasias da Mama/genética , Técnicas de Cocultura , Regulação Neoplásica da Expressão Gênica , Células Estromais/metabolismo , Linhagem Celular Tumoral , Feminino , Humanos , Análise de Componente Principal , Microambiente Tumoral
18.
Clin Trials ; 13(3): 358-66, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-26908536

RESUMO

BACKGROUND: A "platform trial" is a clinical trial with a single master protocol in which multiple treatments are evaluated simultaneously. Adaptive platform designs offer flexible features such as dropping treatments for futility, declaring one or more treatments superior, or adding new treatments to be tested during the course of a trial. METHODS: A simulation study explores the efficiencies of various platform trial designs relative to a traditional two-arm strategy. RESULTS: Platform trials can find beneficial treatments with fewer patients, fewer patient failures, less time, and with greater probability of success than a traditional two-arm strategy. CONCLUSION: In an era of personalized medicine, platform trials provide the innovation needed to efficiently evaluate modern treatments.


Assuntos
Ensaios Clínicos Adaptados como Assunto , Teorema de Bayes , Simulação por Computador , Humanos , Futilidade Médica , Projetos de Pesquisa
19.
Clin Trials ; 13(1): 22-30, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26768569

RESUMO

The outbreak of Ebola virus disease in West Africa is the largest ever recorded. Numerous treatment alternatives for Ebola have been considered, including widely available repurposed drugs, but initiation of enrollment into clinical trials has been limited. The proposed trial is an adaptive platform design. Multiple agents and combinations will be investigated simultaneously. Additionally, new agents may enter the trial as they become available, and failing agents may be removed. In order to accommodate the many possible agents and combinations, a critical feature of this design is the use of response adaptive randomization to assign treatment regimens. As the trial progresses, the randomization ratio evolves to favor the arms that are performing better, making the design also suitable for all-cause pandemic preparedness planning. The study was approved by US and Sierra Leone ethics committees, and reviewed by the US Food and Drug Administration. Additionally, data management, drug supply lines, and local sites were prepared. However, in response to the declining epidemic seen in February 2015, the trial was not initiated. Sierra Leone remains ready to rapidly activate the protocol as an emergency response trial in the event of a resurgence of Ebola. (ClinicalTrials.gov Identifier: NCT02380625.) In summary, we have designed a single controlled trial capable of efficiently identifying highly effective or failing regimens among a rapidly evolving list of proposed therapeutic alternatives for Ebola virus disease and to treat the patients within the trial effectively based on accruing data. Provision of these regimens, if found safe and effective, would have a major impact on future epidemics by providing effective treatment options.


Assuntos
Antivirais/uso terapêutico , Doença pelo Vírus Ebola/tratamento farmacológico , Pandemias , Projetos de Pesquisa , Protocolos Clínicos , Doença pelo Vírus Ebola/epidemiologia , Humanos , Ensaios Clínicos Controlados Aleatórios como Assunto/métodos , Serra Leoa/epidemiologia
20.
Pharm Stat ; 15(5): 396-404, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27306921

RESUMO

The goals of phase II clinical trials are to gain important information about the performance of novel treatments and decide whether to conduct a larger phase III trial. This can be complicated in cases when the phase II trial objective is to identify a novel treatment having several factors. Such multifactor treatment scenarios can be explored using fixed sample size trials. However, the alternative design could be response adaptive randomization with interim analyses and additionally, longitudinal modeling whereby more data could be used in the estimation process. This combined approach allows a quicker and more responsive adaptation to early estimates of later endpoints. Such alternative clinical trial designs are potentially more powerful, faster, and smaller than fixed randomized designs. Such designs are particularly challenging, however, because phase II trials tend to be smaller than subsequent confirmatory phase III trials. The phase II trial may need to explore a large number of treatment variations to ensure that the efficacy of optimal clinical conditions is not overlooked. Adaptive trial designs need to be carefully evaluated to understand how they will perform and to take full advantage of their potential benefits. This manuscript discusses a Bayesian response adaptive randomization design with a longitudinal model that uses a multifactor approach for predicting phase III study success via the phase II data. The approach is based on an actual clinical trial design for the hyperbaric oxygen brain injury treatment trial. Specific details of the thought process and the models informing the trial design are provided. Copyright © 2016 John Wiley & Sons, Ltd.


Assuntos
Lesões Encefálicas/terapia , Ensaios Clínicos Fase II como Assunto/estatística & dados numéricos , Oxigenoterapia Hiperbárica/estatística & dados numéricos , Modelos Estatísticos , Causalidade , Ensaios Clínicos Fase II como Assunto/métodos , Humanos , Estudos Longitudinais , Distribuição Aleatória
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