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1.
Nature ; 615(7950): 80-86, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36859581

RESUMO

The distribution of dryland trees and their density, cover, size, mass and carbon content are not well known at sub-continental to continental scales1-14. This information is important for ecological protection, carbon accounting, climate mitigation and restoration efforts of dryland ecosystems15-18. We assessed more than 9.9 billion trees derived from more than 300,000 satellite images, covering semi-arid sub-Saharan Africa north of the Equator. We attributed wood, foliage and root carbon to every tree in the 0-1,000 mm year-1 rainfall zone by coupling field data19, machine learning20-22, satellite data and high-performance computing. Average carbon stocks of individual trees ranged from 0.54 Mg C ha-1 and 63 kg C tree-1 in the arid zone to 3.7 Mg C ha-1 and 98 kg tree-1 in the sub-humid zone. Overall, we estimated the total carbon for our study area to be 0.84 (±19.8%) Pg C. Comparisons with 14 previous TRENDY numerical simulation studies23 for our area found that the density and carbon stocks of scattered trees have been underestimated by three models and overestimated by 11 models, respectively. This benchmarking can help understand the carbon cycle and address concerns about land degradation24-29. We make available a linked database of wood mass, foliage mass, root mass and carbon stock of each tree for scientists, policymakers, dryland-restoration practitioners and farmers, who can use it to estimate farmland tree carbon stocks from tablets or laptops.


Assuntos
Carbono , Clima Desértico , Ecossistema , Árvores , Carbono/análise , Carbono/metabolismo , Árvores/anatomia & histologia , Árvores/química , Árvores/metabolismo , Dessecação , Imagens de Satélites , África Subsaariana , Aprendizado de Máquina , Madeira/análise , Raízes de Plantas , Agricultura , Recuperação e Remediação Ambiental , Bases de Dados Factuais , Biomassa , Computadores
2.
Drug Metab Dispos ; 50(7): 898-908, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35545256

RESUMO

Fragment crystallizable (Fc) fusion is commonly used for extending the half-life of biotherapeutics such as cytokines. In this work, we studied the pharmacokinetics of Fc-fused interleukin-10 (IL-10) proteins that exhibited potent antitumor activity in mouse syngeneic tumor models. At pharmacologically active doses of ≥0.1 mg/kg, both mouse Fc-mouse IL-10 and human Fc-human IL-10, constructed as the C terminus of the Fc domain fused with IL-10 via a glycine-serine polypeptide linker, exhibited nonlinear pharmacokinetics after intravenous administration to mice at the doses of 0.05, 0.5, and 5 mg/kg. With a nominal dose ratio of 1:10:100; the ratio of the area under the curve for mouse Fc-mouse IL-10 and human Fc-human IL-10 was 1:181:1830 and 1:75:633, respectively. In contrast, recombinant mouse or human IL-10 proteins exhibited linear pharmacokinetics in mice. Compartmental analysis, using the Michaelis-Menten equation with the in vitro IL-10 receptor alpha binding affinity inputted as the Km, unified the pharmacokinetic data across the dose range. Additionally, nontarget-mediated clearance estimated for fusion proteins was ∼200-fold slower than that for cytokines, causing the manifestation of target-mediated drug disposition (TMDD) in the fusion protein pharmacokinetics. The experimental data generated with a mouse IL-10 receptor alpha-blocking antibody and a human Fc-human IL-10 mutant with a reduced receptor binding affinity showed significant improvements in pharmacokinetics, supporting TMDD as the cause of nonlinearity. Target expression and its effect on pharmacokinetics must be determined when considering using Fc as a half-life extension strategy, and pharmacokinetic evaluations need to be performed at a range of doses covering pharmacological activity. SIGNIFICANCE STATEMENT: Target-mediated drug disposition can manifest to affect the pharmacokinetics of a fragment crystallizable (Fc)-fused cytokine when the nontarget-mediated clearance of the cytokine is decreased due to neonatal Fc receptor-mediated recycling and molecular weight increases that reduce the renal clearance. The phenomenon was demonstrated with interleukin-10 Fc-fusion proteins in mice at pharmacologically active doses. Future drug designs using Fc as a half-life extension approach for cytokines need to consider target expression and its effect on pharmacokinetics at relevant doses.


Assuntos
Interleucina-10 , Animais , Meia-Vida , Humanos , Interleucina-10/farmacocinética , Camundongos , Receptores de Interleucina-10 , Proteínas Recombinantes de Fusão/farmacocinética
3.
Ann Fam Med ; 18(3): 218-226, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32393557

RESUMO

PURPOSE: Case management (CM) is a promising intervention for frequent users of health care services. Our research question was how and under what circumstances does CM in primary care work to improve outcomes among frequent users with chronic conditions? METHODS: We conducted a realist synthesis, searching MEDLINE, CINAHL, Embase, and PsycINFO (1996 to September 2017) for articles meeting the following criteria: (1) population: adult frequent users with chronic disease, (2) intervention: CM in a primary care setting with a postintervention evaluation, and (3) primary outcomes: integration of services, health care system use, cost, and patient outcome measures. Academic and gray literature were evaluated for relevance and robustness. Independent reviewers extracted data to identify context, mechanism, and outcome (CMO) configurations. Analysis of CMO configurations allowed for the modification of an initial program theory toward a refined program theory. RESULTS: Of the 9,295 records retrieved, 21 peer-reviewed articles and an additional 89 documents were retained. We evaluated 19 CM interventions and identified 11 CMO configurations. The development of a trusting relationship fostering patient and clinician engagement in the CM intervention was recurrent in many CMO configurations. CONCLUSION: Our refined program theory proposes that in the context of easy access to an experienced and trusted case manager who provides comprehensive care while maintaining positive interactions with patients, the development of this relationship fosters the engagement of both individuals and yields positive outcomes when the following mechanisms are triggered: patients and clinicians feel supported, respected, accepted, engaged, and committed; and patients feel less anxious, more secure, and empowered to self-manage.


Assuntos
Administração de Caso/estatística & dados numéricos , Doença Crônica/terapia , Atenção à Saúde/estatística & dados numéricos , Aceitação pelo Paciente de Cuidados de Saúde/estatística & dados numéricos , Atenção Primária à Saúde/estatística & dados numéricos , Adulto , Feminino , Humanos , Masculino , Avaliação de Processos e Resultados em Cuidados de Saúde
4.
J Synchrotron Radiat ; 25(Pt 2): 385-398, 2018 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-29488917

RESUMO

The investigation of ultrafast dynamics, taking place on the few to sub-picosecond time scale, is today a very active research area pursued in a variety of scientific domains. With the recent advent of X-ray free-electron lasers (XFELs), providing very intense X-ray pulses of duration as short as a few femtoseconds, this research field has gained further momentum. As a consequence, the demand for access strongly exceeds the capacity of the very few XFEL facilities existing worldwide. This situation motivates the development of alternative sub-picosecond pulsed X-ray sources among which femtoslicing facilities at synchrotron radiation storage rings are standing out due to their tunability over an extended photon energy range and their high stability. Following the success of the femtoslicing installations at ALS, BESSY-II, SLS and UVSOR, SOLEIL decided to implement a femtoslicing facility. Several challenges were faced, including operation at the highest electron beam energy ever, and achievement of slice separation exclusively with the natural dispersion function of the storage ring. SOLEIL's setup also enables, for the first time, delivering sub-picosecond pulses simultaneously to several beamlines. This last feature enlarges the experimental capabilities of the facility, which covers the soft and hard X-ray photon energy range. In this paper, the commissioning of this original femtoslicing facility is reported. Furthermore, it is shown that the slicing-induced THz signal can be used to derive a quantitative estimate for the degree of energy exchange between the femtosecond infrared laser pulse and the circulating electron bunch.

5.
Bioorg Med Chem ; 25(20): 5407-5414, 2017 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-28803798

RESUMO

Cancer immunotherapy, unlike traditional cytotoxic chemotherapeutic treatments, engages the immune system to identify cancer cells and stimulate immune responses. The Programmed Death-1 (PD-1) protein is an immunoinhibitory receptor expressed by activated cytotoxic T-lymphocytes (CTL) that seek out and destroy cancer cells. Multiple cancer types express and upregulate the Programmed Death-Ligand 1 (PD-L1) and 2 (PD-L2) which bind to PD-1 as an immune escape mechanism. Nivolumab is a fully human IgG4 anti-PD-1 monoclonal antibody (mAb) approved for treatment of multiple cancer types. This study reports the preparation and in vivo evaluation of 89Zr labeled nivolumab in healthy non-human primates (NHP) as a preliminary study of biodistribution and clearance. The radiochemical and in vivo stabilities of the 89Zr complex were shown to be acceptable for imaging. Three naïve NHPs were intravenously injected with tracer only or tracer co-injected with nivolumab followed by co-registered by positron emission tomography (PET) and magnetic resonance imaging (MRI), acquired for eight days following injection. Image-derived standardized uptake values (SUV) were quantified by region of interest (ROI) analysis. Radioactivity in the spleen was significantly reduced by addition of excess nivolumab compared to the tracer only study at all imaging time points. Liver uptake of the radiotracer was consistent as a clearance organ with minimal signal from other tissues: lung, muscle, brain, heart, and kidney. The results indicate specific biodistribution to the spleen, which can be blocked by co-administration of excess nivolumab. Distribution to other organs is consistent with elimination pathways of antibodies, with primary clearance through the liver.


Assuntos
Anticorpos Monoclonais/farmacocinética , Tomografia por Emissão de Pósitrons , Animais , Anticorpos Monoclonais/administração & dosagem , Anticorpos Monoclonais/química , Relação Dose-Resposta a Droga , Macaca fascicularis , Imageamento por Ressonância Magnética , Masculino , Estrutura Molecular , Nivolumabe , Relação Estrutura-Atividade , Distribuição Tecidual
6.
BMC Public Health ; 17(1): 737, 2017 09 25.
Artigo em Inglês | MEDLINE | ID: mdl-28946855

RESUMO

BACKGROUND: In Canada, public housing programs are an important part of governmental strategies to fight poverty and public exclusion. The Flash on my neighborhood! project is a four-year multiphase community-based participatory action research strategy currently implemented in six public housing developments (n = 1009 households) across the province of Québec, Canada. The goal is to reduce the mental health disparities faced by these public housing tenants compared to the general population, while identifying which environmental and policy changes are needed to turn public housing settings into healthier environments. METHODS: The protocol involves three successive, interconnected phases: 1) Strengths and needs assessment, including community outreach and recruitment of tenants to collaborate as peer researchers, an exploratory qualitative component (photovoice), a systematic neighborhood observation, and a household survey; 2) Action plan development, including a community forum and interactive capacity-building and discussion sessions; 3) Action plan implementation and monitoring. The entire intervention is evaluated using a mixed-method design, framed within a multiple case study perspective. Throughout the project and particularly in the evaluation phase, data will be collected to record a) contextual factors (tenants' previous experience of participation, history of public housing development, etc.); b) activities that took place and elements from the action plan that were implemented; and c) short- and medium-term outcomes (objective and perceived improvements in the quality of the residential setting, both physically and in terms of mental health and social capital). DISCUSSION: The study will provide unprecedented evidence-based information on the key ingredients of a collective intervention process associated with the increased collective empowerment and positive mental health of public housing tenants.


Assuntos
Promoção da Saúde/métodos , Transtornos Mentais/prevenção & controle , Habitação Popular , Características de Residência/estatística & dados numéricos , Meio Social , Promoção da Saúde/organização & administração , Disparidades nos Níveis de Saúde , Humanos , Avaliação de Programas e Projetos de Saúde , Estudos Prospectivos , Quebeque
7.
Bioorg Med Chem Lett ; 26(2): 472-478, 2016 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-26704266

RESUMO

The synthesis, structural activity relationships (SAR), and selectivity profile of a potent series of phenylalanine diamide FXIa inhibitors will be discussed. Exploration of P1 prime and P2 prime groups led to the discovery of compounds with high FXIa affinity, good potency in our clotting assay (aPPT), and high selectivity against a panel of relevant serine proteases as exemplified by compound 21. Compound 21 demonstrated good in vivo efficacy (EC50=2.8µM) in the rabbit electrically induced carotid arterial thrombosis model (ECAT).


Assuntos
Anilidas/farmacologia , Fator XIa/antagonistas & inibidores , Fenilalanina/análogos & derivados , Fenilalanina/farmacologia , Anilidas/síntese química , Animais , Cristalografia por Raios X , Cães , Fenilalanina/síntese química , Coelhos , Relação Estrutura-Atividade
8.
Expert Rev Proteomics ; 12(2): 159-69, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25711416

RESUMO

IL-23 is an important therapeutic target for the treatment of inflammatory diseases. Adnectins are targeted protein therapeutics that are derived from domain III of human fibronectin and have a similar protein scaffold to antibodies. Adnectin 2 was found to bind to IL-23 and compete with the IL-23/IL-23R interaction, posing a potential protein therapeutic. Hydrogen/deuterium exchange mass spectrometry and computational methods were applied to probe the binding interactions between IL-23 and Adnectin 2 and to determine the correlation between the two orthogonal methods. This review summarizes the current structural knowledge about IL-23 and focuses on the applicability of hydrogen/deuterium exchange mass spectrometry to investigate the higher order structure of proteins, which plays an important role in the discovery of new and improved biotherapeutics.


Assuntos
Terapia Biológica , Deutério/química , Hidrogênio/química , Interleucina-23/química , Biologia Computacional , Humanos , Interleucina-23/metabolismo , Espectrometria de Massas/métodos , Ligação Proteica , Conformação Proteica , Receptores de Interleucina/química
9.
Bioorg Med Chem Lett ; 25(4): 925-30, 2015 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-25592713

RESUMO

The structure-activity relationships (SAR) of six-membered ring replacements for the imidazole ring scaffold is described. This work led to the discovery of the potent and selective pyridine (S)-23 and pyridinone (±)-24 factor XIa inhibitors. SAR and X-ray crystal structure data highlight the key differences between imidazole and six-membered ring analogs.


Assuntos
Fator XIa/antagonistas & inibidores , Piridinas/farmacologia , Piridonas/farmacologia , Cristalografia por Raios X , Modelos Moleculares , Relação Estrutura-Atividade
10.
Bioorg Med Chem Lett ; 25(7): 1635-42, 2015 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-25728130

RESUMO

Compound 2 was previously identified as a potent inhibitor of factor XIa lacking oral bioavailability. A structure-based approach was used to design analogs of 2 with novel P1 moieties with good selectivity profiles and oral bioavailability. Further optimization of the P1 group led to the identification of a 4-chlorophenyltetrazole P1 analog, which when combined with further modifications to the linker and P2' group provided compound 32 with FXIa Ki=6.7 nM and modest oral exposure in dogs.


Assuntos
Desenho de Fármacos , Inibidores Enzimáticos/farmacologia , Fator XIa/antagonistas & inibidores , Indazóis/farmacologia , Administração Oral , Animais , Disponibilidade Biológica , Cães , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/administração & dosagem , Inibidores Enzimáticos/química , Fator XIa/efeitos dos fármacos , Humanos , Indazóis/administração & dosagem , Indazóis/química , Modelos Moleculares , Estrutura Molecular , Relação Estrutura-Atividade
11.
Sante Ment Que ; 40(1): 135-52, 2015.
Artigo em Francês | MEDLINE | ID: mdl-26355484

RESUMO

OBJECTIVES: To demonstrate the pertinence of putting personalisation at the heart of mental health services. METHODS: Review of littérature of personalisation research and intervention in the United Kingdom, the country where the personalisation is one of the key themes of the health and social services reform agenda. RESULTS: Presentation of the key challenges in the personalisation agenda and also of web tool directly inspired by research and practices in the UK. CONCLUSION: We think that individuals want to be treated as citizens that want control and choice over their destiny.


Assuntos
Serviços de Saúde Mental , Medicina de Precisão , Humanos
12.
Int J Integr Care ; 24(1): 11, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38370568

RESUMO

Introduction: Integrated community care (ICC) is defined as an interweaving of health-care and social-care interventions deployed in spatial and relational proximity using an interdisciplinary and cross-sectoral approach. Consideration of territory scale and time scale are at the center of ICC practices. Its deployment in public health and social care networks (HSCN) can be complex due to their broad mandate, the complexity of their management, and accountability. Therefore, we aimed to describe ICC delivered by public HSCN to determine how, why, for whom, and in what circumstances ICC works and produces outcomes. Methods: A realist synthesis was conducted consisting of five steps consistent with realist synthesis standards (RAMESES projects) to produce configurations of Context - Mechanism - Outcomes (CMOc) and development of a middle-range explanatory theory of why and how the identified outcomes may have occurred. Results: In total, 26 studies were selected and used, as evidence, to support-either partially or fully-the production of CMOc based on the initial program theory. Nine unique CMO configurations were identified based on the data analyses and team discussion. ICC middle-range theory is informed by the CMO configurations identified. Discussion: This realist synthesis allowed us to identify the central mechanisms of ICC delivered by public HSCN and to produce a middle range theory. ICC is based on a specific philosophy and deployed by a professional agency oriented toward a community agency within a local system of interdisciplinary and cross-sectoral action. Conclusion: Our middle-range theory will provide a solid analytical framework as a foundation for ICC implementation and future research.


Introduction: Les interventions en santé et services sociaux intégrées en proximité des communautés (IIPC) sont définies comme une imbrication d'interventions de soins de santé et de services sociaux à l'échelle du territoire et considérant la temporalité, déployées dans une proximité spatiale et relationnelle au moyen d'une approche interdisciplinaire et intersectorielle. Son déploiement dans les réseaux publics de santé et de soins sociaux (RSSS) peut s'avérer complexe en raison de l'étendue de leur mandat, de la complexité de leur gestion et de leur responsabilité. C'est pourquoi nous avons cherché à décrire les IIPC dispensées par les RSSS publics afin de déterminer comment, pourquoi, pour qui et dans quelles circonstances les IIPC fonctionnent et produisent des résultats. Méthodes utilisées: Une synthèse réaliste a été réalisée en cinq étapes conformes aux normes de synthèse réaliste (projet RAMESES) afin de produire des configurations Contexte ­ Mécanisme ­ Effets (CMOc) et de développer une théorie explicative de moyenne portée sur le pourquoi et le comment des résultats identifiés. Résultats: Au total, 26 études ont été sélectionnées et utilisées comme preuves pour étayer ­ partiellement ou totalement ­ la production de CMOc sur la base de la théorie initiale de programme. Neuf configurations uniques CMO ont été identifiées sur la base des analyses de données et des discussions de l'équipe. La théorie de moyenne portée des IIPC s'appuie sur les configurations CMO identifiées. Discussion: Cette synthèse réaliste nous a permis d'identifier les mécanismes centraux des IIPC déployées par les RSSS publics et de produire une théorie de moyenne portée. Les IIPC sont fondées sur une philosophie et le développement d'une capacité d'agir professionnelle mise en action vers le renforcement de la capacité d'agir de la communauté au sein d'un système local d'action interdisciplinaire et intersectoriel. Conclusion: L'utilisation de notre théorie de moyenne portée pour la mise en œuvre d'IIPC fournira un cadre analytique solide comme base pour des implantations ou des recherches futures.

13.
Microbiol Spectr ; 11(6): e0148223, 2023 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-37812012

RESUMO

IMPORTANCE: In developed countries, the human diet is predominated by food commodities, which have been manufactured, processed, and stored in a food production facility. Little is known about the application of metagenomic sequencing approaches for detecting foodborne pathogens, such as L. monocytogenes, and characterizing microbial diversity in food production ecosystems. In this work, we investigated the utility of 16S rRNA amplicon and quasimetagenomic sequencing for the taxonomic and phylogenetic classification of Listeria culture enrichments of environmental swabs collected from dairy and seafood production facilities. We demonstrated that single-nucleotide polymorphism (SNP) analyses of L. monocytogenes metagenome-assembled genomes (MAGs) from quasimetagenomic data sets can achieve similar resolution as culture isolate whole-genome sequencing. To further understand the impact of genome coverage on MAG SNP cluster resolution, an in silico downsampling approach was employed to reduce the percentage of target pathogen sequence reads, providing an initial estimate of required MAG coverage for subtyping resolution of L. monocytogenes.


Assuntos
Listeria monocytogenes , Humanos , Listeria monocytogenes/genética , Microbiologia de Alimentos , Filogenia , RNA Ribossômico 16S/genética , Ecossistema , Alimentos Marinhos
14.
Sci Data ; 10(1): 250, 2023 05 18.
Artigo em Inglês | MEDLINE | ID: mdl-37202393

RESUMO

A dataset to describe exposed bedrock and surficial geology of Antarctica has been constructed by the GeoMAP Action Group of the Scientific Committee on Antarctic Research (SCAR) and GNS Science. Our group captured existing geological map data into a geographic information system (GIS), refined its spatial reliability, harmonised classification, and improved representation of glacial sequences and geomorphology, thereby creating a comprehensive and coherent representation of Antarctic geology. A total of 99,080 polygons were unified for depicting geology at 1:250,000 scale, but locally there are some areas with higher spatial resolution. Geological unit definition is based on a mixed chronostratigraphic- and lithostratigraphic-based classification. Description of rock and moraine polygons employs the international Geoscience Markup Language (GeoSciML) data protocols to provide attribute-rich and queryable information, including bibliographic links to 589 source maps and scientific literature. GeoMAP is the first detailed geological map dataset covering all of Antarctica. It depicts 'known geology' of rock exposures rather than 'interpreted' sub-ice features and is suitable for continent-wide perspectives and cross-discipline interrogation.

15.
Drug Metab Dispos ; 40(9): 1677-85, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22627466

RESUMO

Although it is widely accepted that one can extend the pharmacokinetic half-life of a therapeutic protein by covalent conjugation with polyethylene glycol (PEG), the disposition properties of such biologics have not yet been fully evaluated. Therefore, a novel [¹4C]-labeling method was developed that can be applied to a biologic conjugated with PEG through a maleimide-cysteine reaction. The method was used to study the tissue and tumor distribution of a PEGylated Adnectin, a recombinant protein derived from the 10th type III domain of fibronectin, in nude mice bearing human xenograft tumors. The PEGylated Adnectin contained a 40-kDa branched PEG (P40B) that was labeled with [¹4C] at the linker region between the PEG and Adnectin, without compromising cellular activity and plasma half-life in mice. After a single intravenous or intraperitoneal dose (33 mg/kg, 1.7 µCi per mouse) of [¹4C]-P40B-Adnectin, quantitative whole-body autoradiography analysis revealed that the liver had the highest uptake of the radioactivity among nontumor tissues, followed by the kidneys and lung. The muscle and brain showed the least penetration of the radioactivity among all tissues examined. In addition, the [¹4C]-P40B-EI-tandem penetrated into the tumor tissue, although the extent of accumulation was largely dependent on tumor type. Therefore, it was possible to assess the tissue distribution of a PEGylated biologic after it had been [¹4C] labeled using the novel method described herein.


Assuntos
Antineoplásicos/farmacocinética , Produtos Biológicos/farmacocinética , Radioisótopos de Carbono/farmacocinética , Fibronectinas/farmacocinética , Marcação por Isótopo/métodos , Neoplasias/metabolismo , Polietilenoglicóis/farmacocinética , Animais , Antineoplásicos/administração & dosagem , Antineoplásicos/síntese química , Autorradiografia , Produtos Biológicos/administração & dosagem , Produtos Biológicos/síntese química , Radioisótopos de Carbono/administração & dosagem , Radioisótopos de Carbono/química , Linhagem Celular Tumoral , Receptores ErbB/metabolismo , Feminino , Fibronectinas/administração & dosagem , Fibronectinas/síntese química , Fibronectinas/genética , Humanos , Injeções Intraperitoneais , Injeções Intravenosas , Camundongos , Camundongos Nus , Mutação , Neoplasias/patologia , Fosforilação , Polietilenoglicóis/administração & dosagem , Polietilenoglicóis/síntese química , Engenharia de Proteínas , Receptor IGF Tipo 1/metabolismo , Proteínas Recombinantes/farmacocinética , Distribuição Tecidual , Carga Tumoral , Imagem Corporal Total
16.
Anal Bioanal Chem ; 402(3): 1229-39, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22130720

RESUMO

High-performance liquid chromatography-tandem mass spectrometry (LC-MS/MS) and enzyme-linked immunosorbent assay (ELISA) methods were developed for the quantification of a PEGylated scaffold protein drug in monkey plasma samples. The LC-MS/MS method was based on the extraction of the therapeutic protein with a water-miscible organic solvent and the subsequent trypsin digestion of the extract followed by the detection of a surrogate peptide. The assay was linear over a range of 10-3,000 ng/mL. The ELISA method utilized a therapeutic target-binding format in which the recombinant target antigen was used to capture the drug in the sample, followed by detection with an anti-PEG monoclonal antibody. The assay range was 30-2,000 ng/mL. A correlation study between the two methods was performed by measuring the drug concentrations in plasma samples from a single-dose pharmacokinetic (PK) study in cynomolgus monkeys following a 5-mg/kg subcutaneous administration (n = 4). In the early time points of the PK profile, the drug concentrations obtained by the LC-MS/MS method agreed very well with those obtained by the ELISA method. However, at later time points, the drug concentrations measured by the LC-MS/MS method were consistently higher than those measured by the ELISA method. The PK parameters calculated based on the concentration data showed that the two methods gave equivalent peak exposure (C(max)) at 24-48 h. However, the LC-MS/MS results exhibited about 1.53-fold higher total exposure (AUC(tot)) than the ELISA results. The discrepancy between the LC-MS/MS and ELISA results was investigated by conducting immunogenicity testing, anti-drug antibody (ADA) epitope mapping, and Western blot analysis of the drug concentrations coupled with Protein G separation. The results demonstrated the presence of ADA specific to the engineered antigen-binding region of the scaffold protein drug that interfered with the ability of the drug to bind to the target antigen used in the ELISA method. In the presence of the ADAs, the ELISA method measured only the active circulating drug (target-binding), while the LC-MS/MS method measured the total circulating drug. The work presented here indicates that the bioanalysis of protein drugs may be complicated owing to the presence of drug-binding endogenous components or ADAs in the post-dose (incurred) samples. The clear understanding of the behavior of different bioanalytical techniques vis-à-vis the potentially interfering components found in incurred samples is critical in selecting bioanalytical strategies for measuring protein drugs.


Assuntos
Ensaio de Imunoadsorção Enzimática/métodos , Preparações Farmacêuticas/sangue , Espectrometria de Massas em Tandem/métodos , Animais , Anticorpos/sangue , Anticorpos/imunologia , Complexo Antígeno-Anticorpo/análise , Complexo Antígeno-Anticorpo/imunologia , Haplorrinos , Preparações Farmacêuticas/química , Polietilenoglicóis/química , Proteínas/química , Proteínas/imunologia
17.
Front Pharmacol ; 13: 829063, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35795558

RESUMO

Pharmacokinetic/pharmacodynamic (PK/PD) modeling was performed to quantitatively integrate preclinical pharmacology and toxicology data for determining the therapeutic index (TI) of an interleukin-10 (IL-10) fragment crystallizable (Fc) fusion protein. Mouse Fc fused with mouse IL-10 (mFc-mIL-10) was studied in mice for antitumor efficacy, and the elevation of interleukin-18 (IL-18) was examined as a PD biomarker. The in vivo mFc-mIL-10 EC50 for the IL-18 induction was estimated to be 2.4 nM, similar to the in vitro receptor binding affinity (Kd) of 3.2 nM. The IL-18 induction was further evaluated in cynomolgus monkeys, where the in vivo induction EC50 by a human IL-10 human Fc-fusion protein (hFc-hIL-10) was 0.08 nM vs. 0.3 nM measured as the in vitro Kd. The extent of the IL-18 induction correlated with mouse antitumor efficacy and was used to connect mouse efficacy to that in monkeys. The PD-based efficacious dose projected in monkeys was comparable to the results obtained using a PK-based method in which mouse efficacious exposure was targeted and corrected for affinity differences between the species. Furthermore, PK/PD relationships were developed for anemia and thrombocytopenia in monkeys treated with hFc-hIL-10, with thrombocytopenia predicted to be dose-limiting toxicity. Using quantitative pharmacology and toxicology information obtained through modeling work in the same species, the TI of hFc-hIL-10 in monkeys was determined to be 2.4 (vs. PD-based efficacy) and 1.2-3 (vs. PK-based efficacy), indicating a narrow safety margin. The model-based approaches were proven valuable to the developability assessment of the IL-10 Fc-fusion protein.

18.
Bioorg Med Chem Lett ; 21(8): 2212-5, 2011 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-21441029

RESUMO

Structure based rationales for the activities of potent N-benzyl-4-heteroaryl-1-(phenylsulfonyl)piperazine-2-carboxamide inhibitors of the hepatitis C viral polymerase are described herein. These compounds bind to the hepatitis C virus non-structural protein 5B (NS5B), and co-crystal structures of select examples from this series with NS5B are reported. Comparison of co-crystal structures of a potent analog with both NS5B genotype 1a and genotype 1b provides a possible explanation for the genotype-selectivity observed with this compound class and suggests opportunities for the further optimization of the series.


Assuntos
Amidas/química , Antivirais/química , Inibidores Enzimáticos/química , Hepacivirus/enzimologia , Proteínas não Estruturais Virais/antagonistas & inibidores , Amidas/síntese química , Amidas/farmacologia , Antivirais/síntese química , Antivirais/farmacologia , Sítios de Ligação , Simulação por Computador , Cristalografia por Raios X , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/farmacologia , Hepacivirus/efeitos dos fármacos , Proteínas não Estruturais Virais/metabolismo
19.
Bioorg Med Chem Lett ; 21(22): 6693-8, 2011 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-21983444

RESUMO

Derived from the HTS hit 1, a series of hydroxyisoquinolines was discovered as potent and selective 11ß-HSD1 inhibitors with good cross species activity. Optimization of substituents at the 1 and 4 positions of the isoquinoline group in addition to the core modifications, with a special focus on enhancing metabolic stability and aqueous solubility, resulted in the identification of several compounds as potent advanced leads.


Assuntos
11-beta-Hidroxiesteroide Desidrogenase Tipo 1/antagonistas & inibidores , 11-beta-Hidroxiesteroide Desidrogenase Tipo 1/metabolismo , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Isoquinolinas/química , Isoquinolinas/farmacologia , Animais , Linhagem Celular , Diabetes Mellitus Tipo 2/tratamento farmacológico , Inibidores Enzimáticos/farmacocinética , Humanos , Isoquinolinas/farmacocinética , Camundongos , Camundongos Endogâmicos BALB C , Relação Estrutura-Atividade
20.
Bioorg Med Chem Lett ; 21(1): 537-41, 2011 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-21078556

RESUMO

Heterocyclic replacement of the isophthalamide phenyl ring in hydroxyethylamine (HEA) BACE-1 inhibitors was explored. A variety of indole-1,3-dicarboxamide HEAs exhibited potent BACE-1 enzyme inhibition, but displayed poor cellular activity. Improvements in cellular activity and aspartic protease selectivity were observed for 7-azaindole-1,3-dicarboxamide HEAs. A methylprolinol-bearing derivative (10n) demonstrated robust reductions in rat plasma Aß levels, but did not lower rat brain Aß due to poor central exposure. The same analog exhibited a high efflux ratio in a bidirectional Caco-2 assay and was likely a substrate of the efflux transporter P-glycoprotein. X-ray crystal structures are reported for two indole HEAs in complex with BACE-1.


Assuntos
Aminas/química , Secretases da Proteína Precursora do Amiloide/antagonistas & inibidores , Ácido Aspártico Endopeptidases/antagonistas & inibidores , Indóis/síntese química , Inibidores de Proteases/química , Piridinas/síntese química , Aminas/síntese química , Aminas/farmacologia , Secretases da Proteína Precursora do Amiloide/metabolismo , Peptídeos beta-Amiloides/sangue , Animais , Ácido Aspártico Endopeptidases/metabolismo , Sítios de Ligação , Cristalografia por Raios X , Indóis/química , Indóis/farmacologia , Inibidores de Proteases/síntese química , Inibidores de Proteases/farmacologia , Estrutura Terciária de Proteína , Piridinas/química , Piridinas/farmacologia , Ratos , Relação Estrutura-Atividade
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