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1.
Biomacromolecules ; 25(8): 5212-5221, 2024 08 12.
Artigo em Inglês | MEDLINE | ID: mdl-38996363

RESUMO

Bacterial infections pose a significant threat to public health worldwide. Hydrogel-based biomaterials have proven to be particularly useful in addressing persistent bacterial infections due to their stimuli-responsive degradability, high biocompatibility, ability to release antibacterial agents on demand, and long-lasting antibacterial activity. Herein, we fabricated ABA-type triblock copolyether hydrogels, wherein, hexanal, a bioactive aldehyde with antibacterial activity, was affixed to the hydrophobic micellar core via acetal linkage. The hydrogel exhibited degradation under acidic environment via the hydrolysis of acetal linkages, leading to the concomitant release of hexanal to exhibit highly potent bactericidal activity against both Escherichia coli and Staphylococcus aureus. Furthermore, a dual-mode release of the model therapeutic agent Nile Red from the hydrophobic micellar core of the hydrogel in conjunction with hexanal was demonstrated using this system. We anticipate that this study will provide a new platform for the development of hydrogels with tailorable release profiles for biologically active compounds that are activated by the acidification triggered by bacterial infection.


Assuntos
Aldeídos , Antibacterianos , Escherichia coli , Hidrogéis , Staphylococcus aureus , Hidrogéis/química , Hidrogéis/farmacologia , Antibacterianos/farmacologia , Antibacterianos/química , Staphylococcus aureus/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Aldeídos/química , Aldeídos/farmacologia , Testes de Sensibilidade Microbiana , Humanos
2.
AAPS PharmSciTech ; 25(7): 240, 2024 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-39390271

RESUMO

The Office of Study Integrity and Surveillance (OSIS) in CDER in FDA coordinates and conducts inspections of sites conducting bioavailability and/or bioequivalence (BA/BE) studies supporting regulatory submissions. In response to travel restrictions during the SARS-CoV-2 (COVID-19) public health emergency, OSIS developed and began conducting remote assessments of BA/BE sites in 2020. This paper provides an overview of remote regulatory assessments (RRAs) and OSIS's approach to RRAs, including procedures, experiences, and examples of findings during RRAs. In addition, as OSIS continues to utilize RRAs while resuming inspections, some areas for improvement are discussed.


Assuntos
Disponibilidade Biológica , Equivalência Terapêutica , United States Food and Drug Administration , Humanos , Estados Unidos , United States Food and Drug Administration/normas
3.
Bioanalysis ; 16(9): 307-364, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38913185

RESUMO

The 17th Workshop on Recent Issues in Bioanalysis (17th WRIB) took place in Orlando, FL, USA on June 19-23, 2023. Over 1000 professionals representing pharma/biotech companies, CROs, and multiple regulatory agencies convened to actively discuss the most current topics of interest in bioanalysis. The 17th WRIB included 3 Main Workshops and 7 Specialized Workshops that together spanned 1 week to allow an exhaustive and thorough coverage of all major issues in bioanalysis of biomarkers, immunogenicity, gene therapy, cell therapy and vaccines.Moreover, in-depth workshops on "EU IVDR 2017/746 Implementation and impact for the Global Biomarker Community: How to Comply with this NEW Regulation" and on "US FDA/OSIS Remote Regulatory Assessments (RRAs)" were the special features of the 17th edition.As in previous years, WRIB continued to gather a wide diversity of international, industry opinion leaders and regulatory authority experts working on both small and large molecules as well as gene, cell therapies and vaccines to facilitate sharing and discussions focused on improving quality, increasing regulatory compliance, and achieving scientific excellence on bioanalytical issues.This 2023 White Paper encompasses recommendations emerging from the extensive discussions held during the workshop and is aimed to provide the bioanalytical community with key information and practical solutions on topics and issues addressed, in an effort to enable advances in scientific excellence, improved quality and better regulatory compliance. Due to its length, the 2023 edition of this comprehensive White Paper has been divided into three parts for editorial reasons.This publication covers the recommendations on Mass Spectrometry Assays, Regulated Bioanalysis/BMV (Part 1A) and Regulatory Inputs (Part 1B). Part 2 (Biomarkers, IVD/CDx, LBA and Cell-Based Assays) and Part 3 (Gene Therapy, Cell therapy, Vaccines and Biotherapeutics Immunogenicity) are published in volume 16 of Bioanalysis, issues 7 and 8 (2024), respectively.


Assuntos
Biomarcadores , Terapia Baseada em Transplante de Células e Tecidos , Proteômica , Humanos , Biomarcadores/análise , Cromatografia/métodos , Terapia Genética , Espectrometria de Massas/métodos , Proteômica/métodos
4.
Environ Pollut ; 329: 121668, 2023 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-37087090

RESUMO

Plastics have been used for about 100 years, and daily-use products composed of plastics are now prevalent. As a result, humans are very easily exposed to the plastic particles generated from the daily-use plastics. However, studies on cellular uptake of nanoplastics in "human cells" have only recently begun to attract attention. In previous studies, definitions of nanoplastics and microplastics were vague, but recently, they have been considered to be different and are being studied separately. However, nanoplastics, unlike plastic particles of other sizes such as macro- and microplastics, can be absorbed by human cells, and thus can cause various risks such as cytotoxicity, inflammation, oxidative stress, and even diseases such as cancer82, 83. and diabetes (Fan et al., 2022; Wang et al., 2023). Thus, in this review, we defined microplastics and nanoplastics to be different and described the potential risks of nanoplastics to human caused by cellular uptake according to their diverse factors. In addition, during and following plastic product usage a substantial number of fragments of different sizes can be generated, including nanoplastics. Fragmentation of microplastics into nanoplastics may also occur during ingestion and inhalation, which can potentially cause long-term hazards to human health. However, there are still few in vivo studies conducted on the health effect of nanoplastics ingestion and inhalation.


Assuntos
Microplásticos , Poluentes Químicos da Água , Humanos , Microplásticos/toxicidade , Plásticos/toxicidade , Poluentes Químicos da Água/toxicidade , Poluentes Químicos da Água/análise
5.
Bioanalysis ; 15(16): 955-1016, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37650500

RESUMO

The 16th Workshop on Recent Issues in Bioanalysis (16th WRIB) took place in Atlanta, GA, USA on September 26-30, 2022. Over 1000 professionals representing pharma/biotech companies, CROs, and multiple regulatory agencies convened to actively discuss the most current topics of interest in bioanalysis. The 16th WRIB included 3 Main Workshops and 7 Specialized Workshops that together spanned 1 week in order to allow exhaustive and thorough coverage of all major issues in bioanalysis, biomarkers, immunogenicity, gene therapy, cell therapy and vaccines. Moreover, in-depth workshops on the ICH M10 BMV final guideline (focused on this guideline training, interpretation, adoption and transition); mass spectrometry innovation (focused on novel technologies, novel modalities, and novel challenges); and flow cytometry bioanalysis (rising of the 3rd most common/important technology in bioanalytical labs) were the special features of the 16th edition. As in previous years, WRIB continued to gather a wide diversity of international, industry opinion leaders and regulatory authority experts working on both small and large molecules as well as gene, cell therapies and vaccines to facilitate sharing and discussions focused on improving quality, increasing regulatory compliance, and achieving scientific excellence on bioanalytical issues. This 2022 White Paper encompasses recommendations emerging from the extensive discussions held during the workshop and is aimed to provide the bioanalytical community with key information and practical solutions on topics and issues addressed, in an effort to enable advances in scientific excellence, improved quality and better regulatory compliance. Due to its length, the 2022 edition of this comprehensive White Paper has been divided into three parts for editorial reasons. This publication (Part 1A) covers the recommendations on Mass Spectrometry and ICH M10. Part 1B covers the Regulatory Agencies' Inputs on Bioanalysis, Biomarkers, Immunogenicity, Gene & Cell Therapy and Vaccine. Part 2 (LBA, Biomarkers/CDx and Cytometry) and Part 3 (Gene Therapy, Cell therapy, Vaccines and Biotherapeutics Immunogenicity) are published in volume 15 of Bioanalysis, issues 15 and 14 (2023), respectively.


Assuntos
Cromatografia , Vacinas , Biomarcadores , Terapia Baseada em Transplante de Células e Tecidos , Espectrometria de Massas , Oligonucleotídeos , Tecnologia
6.
Nat Struct Mol Biol ; 14(7): 653-61, 2007 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-17572682

RESUMO

The eight twenty-one protein, ETO, is implicated in 12%-15% of acute human leukemias as part of a gene fusion with RUNX1 (also called AML1). Of the four ETO domains related to Drosophila melanogaster Nervy, only two are required to induce spontaneous myeloid leukemia upon transplantation into the mouse. One of these domains is related in sequence to TAF4, a component of TFIID. The structure of this domain, ETO-TAFH, is similar to yeast Rpb4 and to Escherichia coli sigma(70); it is the first TAF-related protein with structural similarity to the multisubunit RNA polymerases. Overlapping surfaces of ETO-TAFH interact with an autonomous repression domain of the nuclear receptor corepressor N-CoR and with a conserved activation domain from the E-box family of transcription factors. Thus, ETO-TAFH acts as a structural platform that can interchange negative and positive coregulatory proteins to control transcription.


Assuntos
Proteínas de Ligação a DNA/química , Proteínas Proto-Oncogênicas/química , Proteínas Repressoras/química , Fator de Transcrição TFIID/química , Fatores de Transcrição/química , Animais , Proteínas de Ligação a DNA/genética , Regulação para Baixo , Elementos E-Box , Regulação da Expressão Gênica , Sequências Hélice-Alça-Hélice , Humanos , Camundongos , Dados de Sequência Molecular , Estrutura Terciária de Proteína , Proteínas Proto-Oncogênicas/genética , Proteína 1 Parceira de Translocação de RUNX1 , Proteínas Repressoras/genética , Homologia de Sequência de Aminoácidos , Fator de Transcrição TFIID/genética , Fatores de Transcrição/genética , Transcrição Gênica , Técnicas do Sistema de Duplo-Híbrido , Regulação para Cima
7.
Clin Pharmacol Ther ; 112(1): 31-43, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-34358334

RESUMO

With the globalization of clinical trials, regulators have increased collaboration to evaluate the adequacy of clinical trial conduct and to optimize regulatory oversight. The 2020 joint Good Clinical Practice (GCP) symposium of the US Food and Drug Administration and the UK Medicines and Healthcare products Regulatory Agency provided the agencies' perspectives on the challenges in ensuring data quality in novel clinical trial designs and the importance of the management and documentation of protocol deviations, sponsor oversight of clinical trials, and use of electronic source data, including electronic health records. This paper summarizes considerations of both agencies on these topics, along with case examples. This paper touches upon considerations when using real-world data to support regulatory decisions. It also discusses the impact of the coronavirus disease 2019 (COVID-19) pandemic on clinical trial conduct and underscores the importance of well-designed, resilient, and adaptable systems for GCP compliance and data integrity.


Assuntos
COVID-19 , Órgãos Governamentais , Humanos , Pandemias , Reino Unido , Estados Unidos , United States Food and Drug Administration
8.
Neurobiol Dis ; 43(1): 248-56, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21458569

RESUMO

Huntington's disease (HD) is a late-onset, neurodegenerative disease for which there are currently no cures nor disease-modifying treatments. Here we report the identification of several potential anti-inflammatory targets for HD using an ex vivo model of HD that involves the acute transfection of human mutant huntingtin-based constructs into rat brain slices. This model recapitulates key components of the human disease, including the formation of intracellular huntingtin protein (HTT)-containing inclusions and the progressive neurodegeneration of striatal neurons-both occurring within the native tissue context of these neurons. Using this "high-throughput biology" screening platform, we conducted a hypothesis-neutral screen of a collection of drug-like compounds which identified several anti-inflammatory targets that provided neuroprotection against HTT fragment-induced neurodegeneration. The nature of these targets provide further support for non-cell autonomous mechanisms mediating significant aspects of neuropathogenesis induced by mutant HTT fragment proteins.


Assuntos
Anti-Inflamatórios não Esteroides/metabolismo , Corpo Estriado/efeitos dos fármacos , Corpo Estriado/metabolismo , Sistemas de Liberação de Medicamentos/métodos , Doença de Huntington/tratamento farmacológico , Degeneração Neural/tratamento farmacológico , Animais , Animais Recém-Nascidos , Anti-Inflamatórios não Esteroides/farmacologia , Corpo Estriado/patologia , Avaliação Pré-Clínica de Medicamentos/métodos , Humanos , Doença de Huntington/metabolismo , Doença de Huntington/patologia , Inflamação/tratamento farmacológico , Inflamação/metabolismo , Inflamação/patologia , Degeneração Neural/metabolismo , Degeneração Neural/patologia , Fármacos Neuroprotetores/metabolismo , Fármacos Neuroprotetores/farmacologia , Técnicas de Cultura de Órgãos , Ratos , Ratos Sprague-Dawley
9.
J Neurotrauma ; 38(9): 1338-1348, 2021 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-20597685

RESUMO

After spinal cord injury (SCI) in mammals, there is only limited repair and, consequently, only moderate recovery. One mechanism frequently discussed to be involved in this recovery is plasticity (i.e., adaptations in spared neuronal circuitries). In the current study, we tested the effect of an intrathecal application of the TrkB agonist antibody, 29D7, on plasticity after cervical SCI in adult rats. Treatment with 29D7 for 4 weeks resulted in an ∼50% increase in collateral sprouting of severed corticospinal tract fibers above the lesion compared to the control group and enhanced branching in the gray matter rostral to the injury. Growth-associated protein 43 immunoreactivity in the spinal cord rostral to the level of the injury as well as contralateral to the lesion was also increased. These indications of enhanced plasticity by 29D7 were paralleled by improved performances of the mildly affected paw, as assessed by Montoya and tray reaching tasks. The reaching behaviors of the paw ipsilateral to the side of severe injury to the cortico- and rubrospinal tract were not altered by the treatment. The present study suggests that 29D7 may be a potential candidate to promote plasticity and functional recovery, especially after moderate SCI. Future studies confirming these results, along with a potential combinatory therapy including rehabilitative training, will be needed to evaluate the clinical value of such a treatment.


Assuntos
Anticorpos Monoclonais/administração & dosagem , Medula Cervical/lesões , Plasticidade Neuronal/efeitos dos fármacos , Receptor trkB/agonistas , Traumatismos da Medula Espinal/tratamento farmacológico , Animais , Medula Cervical/efeitos dos fármacos , Medula Cervical/fisiologia , Feminino , Bombas de Infusão , Injeções Espinhais , Plasticidade Neuronal/fisiologia , Ratos , Ratos Endogâmicos Lew , Traumatismos da Medula Espinal/fisiopatologia
10.
Clin Pharmacol Ther ; 108(5): 949-963, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-31958142

RESUMO

Good Clinical Practice (GCP) is an international ethical and scientific quality standard for designing, conducting, recording, and reporting clinical trials. Regulatory agencies conduct GCP inspections to verify the integrity of data generated in clinical trials and to assure the protection of human research subjects, in addition to ensuring that clinical trials are conducted according to the applicable regulations. The first joint GCP workshop of the US Food and Drug Administration (FDA) Center for Drug Evaluation and Research (CDER) and the United Kingdom Medicines and Healthcare products Regulatory Agency (MHRA-UK) was held in October 2018 and provided the agencies' perspectives on the importance of data quality management practices on data integrity. Regulatory perspectives on data blinding to minimize introduction of bias, and the role of audit trails in assessing data integrity in global clinical trials were discussed. This paper summarizes considerations of both agencies on these topics, along with case examples.


Assuntos
Ensaios Clínicos como Assunto/normas , Gerenciamento de Dados/normas , Aprovação de Drogas , Projetos de Pesquisa/normas , United States Food and Drug Administration , Segurança Computacional/normas , Confiabilidade dos Dados , Coleta de Dados/normas , Europa (Continente) , Humanos , Estudos Multicêntricos como Assunto , Estados Unidos
11.
Bioanalysis ; 11(23): 2099-2132, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31833782

RESUMO

The 2019 13th Workshop on Recent Issues in Bioanalysis (WRIB) took place in New Orleans, LA on 1-5 April 2019 with an attendance of over 1000 representatives from pharmaceutical/biopharmaceutical companies, biotechnology companies, contract research organizations and regulatory agencies worldwide. WRIB was once again a 5-day, week-long event - a full immersion week of bioanalysis, biomarkers, immunogenicity and gene therapy. As usual, it was specifically designed to facilitate sharing, reviewing, discussing and agreeing on approaches to address the most current issues of interest including both small- and large-molecule bioanalysis involving LCMS, hybrid LBA/LCMS, LBA cell-based/flow cytometry assays and qPCR approaches. This 2019 White Paper encompasses recommendations emerging from the extensive discussions held during the workshop, and is aimed to provide the bioanalytical community with key information and practical solutions on topics and issues addressed, in an effort to enable advances in scientific excellence, improved quality and better regulatory compliance. Due to its length, the 2019 edition of this comprehensive White Paper has been divided into three parts for editorial reasons. This publication (Part 2) covers the recommendations on the 2018 FDA BMV guidance, 2019 ICH M10 BMV draft guideline and regulatory agencies' input on bioanalysis, biomarkers, immunogenicity and gene therapy. Part 1 (Innovation in small molecules and oligonucleotides and mass spectrometry method development strategies for large molecules bioanalysis) and Part 3 (New insights in biomarker assay validation, current and effective strategies for critical reagent management, flow cytometry validation in drug discovery and development and CLSI H62, interpretation of the 2019 FDA immunogenicity guidance and gene therapy bioanalytical challenges) are published in volume 10 of Bioanalysis, issues 22 and 24 (2019), respectively.


Assuntos
Bioensaio/normas , Biomarcadores/análise , Guias como Assunto , Fenômenos Imunogenéticos , Relatório de Pesquisa , United States Food and Drug Administration/legislação & jurisprudência , Humanos , Estados Unidos
12.
Bioanalysis ; 10(22): 1781-1801, 2018 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-30488725

RESUMO

The 2018 12th Workshop on Recent Issues in Bioanalysis (12th WRIB) took place in Philadelphia, PA, USA on April 9-13, 2018 with an attendance of over 900 representatives from pharmaceutical/biopharmaceutical companies, biotechnology companies, contract research organizations and regulatory agencies worldwide. WRIB was once again a 5-day full immersion in bioanalysis, biomarkers and immunogenicity. As usual, it was specifically designed to facilitate sharing, reviewing, discussing and agreeing on approaches to address the most current issues of interest including both small- and large-molecule bioanalysis involving LC-MS, hybrid ligand binding assay (LBA)/LC-MS and LBA/cell-based assays approaches. This 2018 White Paper encompasses recommendations emerging from the extensive discussions held during the workshop, and is aimed to provide the bioanalytical community with key information and practical solutions on topics and issues addressed, in an effort to enable advances in scientific excellence, improved quality and better regulatory compliance. Due to its length, the 2018 edition of this comprehensive White Paper has been divided into three parts for editorial reasons. This publication (Part 1) covers the recommendations for LC-MS for small molecules, peptides, oligonucleotides and small molecule biomarkers. Part 2 (hybrid LBA/LC-MS for biotherapeutics and regulatory agencies' inputs) and Part 3 (large molecule bioanalysis, biomarkers and immunogenicity using LBA and cell-based assays) are published in volume 10 of Bioanalysis, issues 23 and 24 (2018), respectively.


Assuntos
Biomarcadores/análise , Oligonucleotídeos/análise , Peptídeos/análise , Animais , Cromatografia Líquida , Humanos , Espectrometria de Massas , Philadelphia
13.
Bioanalysis ; 10(23): 1897-1917, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30488729

RESUMO

The 2018 12th Workshop on Recent Issues in Bioanalysis took place in Philadelphia, PA, USA on April 9-13, 2018 with an attendance of over 900 representatives from pharmaceutical/biopharmaceutical companies, biotechnology companies, contract research organizations and regulatory agencies worldwide. WRIB was once again a 5-day, week-long event - a full immersion week of bioanalysis, biomarkers and immunogenicity. As usual, it was specifically designed to facilitate sharing, reviewing, discussing and agreeing on approaches to address the most current issues of interest including both small- and large-molecule bioanalysis involving LCMS, hybrid LBA/LCMS and LBA/cell-based assays approaches. This 2018 White Paper encompasses recommendations emerging from the extensive discussions held during the workshop and is aimed to provide the bioanalytical community with key information and practical solutions on topics and issues addressed, in an effort to enable advances in scientific excellence, improved quality and better regulatory compliance. Due to its length, the 2018 edition of this comprehensive White Paper has been divided into three parts for editorial reasons. This publication (Part 2) covers the recommendations for PK, PD and ADA assays by hybrid LBA/LCMS and regulatory agencies' input. Part 1 (LCMS for small molecules, peptides, oligonucleotides and small molecule biomarkers) and Part 3 (LBA/cell-based assays: immunogenicity, biomarkers and PK assays) are published in volume 10 of Bioanalysis, issues 22 and 24 (2018), respectively.


Assuntos
Antígenos/análise , Bioensaio/normas , Biomarcadores/análise , Legislação Médica/tendências , Estados Unidos
14.
J Neurosci ; 26(37): 9394-403, 2006 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-16971523

RESUMO

Tyrosine kinase receptor B (TrkB) mediates neurotrophic effects of brain-derived neurotrophic factor (BDNF) to increase neuronal survival, differentiation, synaptic plasticity, and neurogenesis. The therapeutic potential of TrkB activation using BDNF has been demonstrated well in several preclinical models of CNS diseases, validating TrkB as a promising drug target. Therefore, we aimed to develop TrkB-specific receptor agonists by using a monoclonal antibody approach. After generation of hybridoma clones and assessment of their binding and functional activity, we identified five mouse monoclonal antibodies that show highly selective binding to TrkB and that induce robust activation of TrkB signaling. Epitope mapping studies using competition analysis showed that each of the monoclonal antibodies recognizes a unique binding site on TrkB, some of which are distinct from BDNF docking sites. These antibodies behave as true agonists based on their ability to both activate proximal and secondary signaling molecules downstream of TrkB receptors and promote neuronal survival and neurite outgrowth. The binding affinities and the functional efficacy of these antibodies are comparable to those of BDNF, whereas they do not bind to the p75 low-affinity neurotrophin receptor at all. Therefore, they could represent novel reagents to explore the pathophysiological roles of TrkB and its potential therapeutic utility in treating CNS disorders.


Assuntos
Anticorpos Monoclonais/farmacologia , Fator Neurotrófico Derivado do Encéfalo/agonistas , Diferenciação Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Neuritos/efeitos dos fármacos , Receptor trkB/agonistas , Animais , Anticorpos Monoclonais/biossíntese , Anticorpos Monoclonais/imunologia , Especificidade de Anticorpos/imunologia , Sítios de Ligação de Anticorpos/imunologia , Encefalopatias/tratamento farmacológico , Encefalopatias/metabolismo , Encefalopatias/fisiopatologia , Diferenciação Celular/fisiologia , Linhagem Celular Tumoral , Sobrevivência Celular/fisiologia , Células Cultivadas , Reações Cruzadas , Feminino , Humanos , Hibridomas , Camundongos , Camundongos Endogâmicos BALB C , Neuritos/metabolismo , Ratos , Receptor trkB/imunologia , Receptor trkB/metabolismo , Sistemas do Segundo Mensageiro/efeitos dos fármacos , Sistemas do Segundo Mensageiro/fisiologia , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/fisiologia
15.
Curr Neuropharmacol ; 5(1): 19-33, 2007 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18615151

RESUMO

Recent improvements in brain slice technology have made this biological preparation increasingly useful for examining pathophysiology of brain diseases in a tissue context. Brain slices maintain many aspects of in vivo biology, including functional local synaptic circuitry with preserved brain architecture, while allowing good experimental access and precise control of the extracellular environment, making them ideal platforms for dissection of molecular pathways underlying neuronal dysfunction. Importantly, these ex vivo systems permit direct treatment with pharmacological agents modulating these responses and thus provide surrogate therapeutic screening systems without recourse to whole animal studies. Virus or particle mediated transgenic expression can also be accomplished relatively easily to study the function of novel genes in a normal or injured brain tissue context.In this review we will discuss acute brain injury models in organotypic hippocampal and co-culture systems and the effects of pharmacological modulation on neurodegeneration. The review will also cover the evidence of developmental plasticity in these ex vivo models, demonstrating emergence of injury-stimulated neuronal progenitor cells, and neurite sprouting and axonal regeneration following pathway lesioning. Neuro-and axo-genesis are emerging as significant factors contributing to brain repair following many acute and chronic neurodegenerative disorders. Therefore brain slice models may provide a critical contextual experimental system to explore regenerative mechanisms in vitro.

16.
Bioanalysis ; 9(22): 1807-1825, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29148835

RESUMO

The 2017 11th Workshop on Recent Issues in Bioanalysis (11th WRIB) took place in Los Angeles/Universal City, California from 3 April 2017 to 7 April 2017 with participation of close to 750 professionals from pharmaceutical/biopharmaceutical companies, biotechnology companies, contract research organizations and regulatory agencies worldwide. WRIB was once again a 5-day, weeklong event - A Full Immersion Week of Bioanalysis, Biomarkers and Immunogenicity. As usual, it was specifically designed to facilitate sharing, reviewing, discussing and agreeing on approaches to address the most current issues of interest including both small and large molecule analysis involving LCMS, hybrid LBA/LCMS and ligand-binding assay (LBA) approaches. This 2017 White Paper encompasses recommendations emerging from the extensive discussions held during the workshop, and is aimed to provide the bioanalytical community with key information and practical solutions on topics and issues addressed, in an effort to enable advances in scientific excellence, improved quality and better regulatory compliance. Due to its length, the 2017 edition of this comprehensive White Paper has been divided into three parts for editorial reasons. This publication (Part 1) covers the recommendations for Small Molecules, Peptides and Small Molecule Biomarkers using LCMS. Part 2 (Biotherapeutics, Biomarkers and Immunogenicity Assays using Hybrid LBA/LCMS and Regulatory Agencies' Inputs) and Part 3 (LBA: Immunogenicity, Biomarkers and PK Assays) are published in volume 9 of Bioanalysis, issues 23 and 24 (2017), respectively.


Assuntos
Biomarcadores/análise , Cromatografia Líquida de Alta Pressão , Espectrometria de Massas , Peptídeos/análise , Bibliotecas de Moléculas Pequenas/análise , Conferências de Consenso como Assunto , Guias como Assunto , Ligantes , Bibliotecas de Moléculas Pequenas/química
17.
Bioanalysis ; 9(23): 1895-1912, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29205053

RESUMO

The 2017 11th Workshop on Recent Issues in Bioanalysis (11th WRIB) took place in Los Angeles/Universal City, California on 3-7 April 2017 with participation of close to 750 professionals from pharmaceutical/biopharmaceutical companies, biotechnology companies, contract research organizations and regulatory agencies worldwide. WRIB was once again a 5-day, weeklong event - a full immersion week of bioanalysis, biomarkers and immunogenicity. As usual, it was specifically designed to facilitate sharing, reviewing, discussing and agreeing on approaches to address the most current issues of interest including both small and large molecule analysis involving LCMS, hybrid ligand binding assay (LBA)/LCMS and LBA approaches. This 2017 White Paper encompasses recommendations emerging from the extensive discussions held during the workshop, and is aimed to provide the bioanalytical community with key information and practical solutions on topics and issues addressed, in an effort to enable advances in scientific excellence, improved quality and better regulatory compliance. Due to its length, the 2017 edition of this comprehensive White Paper has been divided into three parts for editorial reasons. This publication (Part 2) covers the recommendations for biotherapeutics, biomarkers and immunogenicity assays using hybrid LBA/LCMS and regulatory agencies' inputs. Part 1 (LCMS for small molecules, peptides and small molecule biomarkers) and Part 3 (LBA: immunogenicity, biomarkers and pharmacokinetic assays) are published in Volume 9 of Bioanalysis, issues 22 and 24 (2017), respectively.


Assuntos
Biomarcadores/análise , Imunidade Ativa , Espectrometria de Massas , Cromatografia Líquida de Alta Pressão , Conferências de Consenso como Assunto , Regulamentação Governamental , Ligantes
18.
Bioanalysis ; 9(24): 1967-1996, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29205064

RESUMO

The 2017 11th Workshop on Recent Issues in Bioanalysis took place in Los Angeles/Universal City, California, on 3-7 April 2017 with participation of close to 750 professionals from pharmaceutical/biopharmaceutical companies, biotechnology companies, contract research organizations and regulatory agencies worldwide. WRIB was once again a 5-day, week-long event - a full immersion week of bioanalysis, biomarkers and immunogenicity. As usual, it was specifically designed to facilitate sharing, reviewing, discussing and agreeing on approaches to address the most current issues of interest including both small- and large-molecule analysis involving LC-MS, hybrid ligand-binding assay (LBA)/LC-MS and LBA approaches. This 2017 White Paper encompasses recommendations emerging from the extensive discussions held during the workshop, and is aimed to provide the bioanalytical community with key information and practical solutions on topics and issues addressed, in an effort to enable advances in scientific excellence, improved quality and better regulatory compliance. Due to its length, the 2017 edition of this comprehensive White Paper has been divided into three parts for editorial reasons. This publication (Part 3) covers the recommendations for large-molecule bioanalysis, biomarkers and immunogenicity using LBA. Part 1 (LC-MS for small molecules, peptides and small molecule biomarkers) and Part 2 (hybrid LBA/LC-MS for biotherapeutics and regulatory agencies' inputs) are published in volume 9 of Bioanalysis, issues 22 and 23 (2017), respectively.


Assuntos
Biomarcadores/análise , Imunidade Ativa , Cromatografia Líquida , Conferências de Consenso como Assunto , Tolerância a Medicamentos , Guias como Assunto , Ligantes , Espectrometria de Massas , Farmacocinética
19.
IEEE Trans Biomed Circuits Syst ; 9(1): 138-51, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25069119

RESUMO

A single-chip 32-channel analog beamformer is proposed. It achieves a delay resolution of 4 ns and a maximum delay range of 768 ns. It has a focal-point based architecture, which consists of 7 sub-analog beamformers (sub-ABF). Each sub-ABF performs a RX focusing operation for a single focal point. Seven sub-ABFs perform a time-interleaving operation to achieve the maximum delay range of 768 ns. Phase interpolators are used in sub-ABFs to generate sampling clocks with the delay resolution of 4 ns from a low frequency system clock of 5 MHz. Each sub-ABF samples 32 echo signals at different times into sampling capacitors, which work as analog memory cells. The sampled 32 echo signals of each sub-ABF are originated from one target focal point at one instance. They are summed at one instance in a sub-ABF to perform the RX focusing for the target focal point. The proposed ABF chip has been fabricated in a 0.13- µ m CMOS process with an active area of 16 mm (2). The total power consumption is 287 mW. In measurement, the digital echo signals from a commercial ultrasound medical imaging machine were applied to the fabricated chip through commercial DAC chips. Due to the speed limitation of the DAC chips, the delay resolution was relaxed to 10 ns for the real-time measurement. A linear array transducer with no steering operation is used in this work.


Assuntos
Diagnóstico por Imagem/instrumentação , Ultrassonografia/instrumentação , Desenho de Equipamento , Humanos , Interpretação de Imagem Assistida por Computador , Razão Sinal-Ruído , Transdutores
20.
Neurochem Int ; 45(1): 117-27, 2004 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-15082229

RESUMO

Oxygen-glucose deprivation (OGD) induced neuron-specific cell death in organotypic hippocampal slice cultures. Neuronal death was first evident in the CA1 region 24 h after the injury as assessed by propidium iodide (PI) labeling, and continued to extend to the CA3/4 region up to 72 h. At 6 days post-OGD, PI labeling was weak and diffuse with no clear demarcation of pyknotic nuclei. To characterize biochemical changes produced by OGD, cellular efflux of three key amino acid neurotransmitters was evaluated. OGD elicited large increases in the release of GABA and aspartate (55- and 4.5-fold increase over basal, respectively), while there were no detectable changes in extracellular glutamate levels. In order to ascertain the existence of the synaptic pool of glutamate, sister cultures were treated with sodium azide. This evoked a strong increase in glutamate release, suggesting the intactness of the glutamate system. Further studies revealed a time-dependent activation of caspase 3 following OGD, shown by immunoblot analysis as well as by confocal laser scanning microscopy. While we did not observe the activation of caspases 1, 2, or 8 in our model, the activation of caspase 9 was evident, peaking at 12 h post-OGD. Despite no apparent increase in glutamate release by ischemic slices, treatment with a N-methyl-D-aspartate (NMDA) antagonist or an alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) antagonist significantly reduced neuronal death. Furthermore, a pan-caspase inhibitor (zVAD-fmk), but not the caspase 3 inhibitor (DEVD-fmk), provided partial neuroprotection. Inhibition of a Ca(2+)-dependent cysteine protease, calpain, by MDL28170 also elicited partial neuroprotective effects.


Assuntos
Apoptose/fisiologia , Hipocampo/metabolismo , Animais , Apoptose/efeitos dos fármacos , Caspases/metabolismo , Morte Celular/efeitos dos fármacos , Morte Celular/fisiologia , Hipóxia Celular/efeitos dos fármacos , Hipóxia Celular/fisiologia , Hipocampo/efeitos dos fármacos , Hipocampo/patologia , Fármacos Neuroprotetores/farmacologia , Técnicas de Cultura de Órgãos , Ratos , Fatores de Tempo
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