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1.
Chaos ; 32(4): 043112, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35489849

RESUMO

To predict rare extreme events using deep neural networks, one encounters the so-called small data problem because even long-term observations often contain few extreme events. Here, we investigate a model-assisted framework where the training data are obtained from numerical simulations, as opposed to observations, with adequate samples from extreme events. However, to ensure the trained networks are applicable in practice, the training is not performed on the full simulation data; instead, we only use a small subset of observable quantities, which can be measured in practice. We investigate the feasibility of this model-assisted framework on three different dynamical systems (Rössler attractor, FitzHugh-Nagumo model, and a turbulent fluid flow) and three different deep neural network architectures (feedforward, long short-term memory, and reservoir computing). In each case, we study the prediction accuracy, robustness to noise, reproducibility under repeated training, and sensitivity to the type of input data. In particular, we find long short-term memory networks to be most robust to noise and to yield relatively accurate predictions, while requiring minimal fine-tuning of the hyperparameters.


Assuntos
Aprendizado Profundo , Simulação por Computador , Memória de Longo Prazo , Redes Neurais de Computação , Reprodutibilidade dos Testes
2.
Pharmaceutics ; 13(4)2021 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-33918602

RESUMO

A sequential pharmacokinetic (PK) and pharmacodynamic (PD) model was built with Nonlinear Mixed Effects Modelling based on data from a first-in-human trial of a novel biologic, MEDI7836. MEDI7836 is a human immunoglobulin G1 lambda (IgG1λ-YTE) monoclonal antibody, with an Fc modification to reduce metabolic clearance. MEDI7836 specifically binds to, and functionally neutralizes interleukin-13. Thirty-two healthy male adults were enrolled into a dose-escalation clinical trial. Four active doses were tested (30, 105, 300, and 600 mg) with 6 volunteers enrolled per cohort. Eight volunteers received placebo as control. Following single subcutaneous administration (SC), individual time courses of serum MEDI7836 concentrations, and the resulting serum IL13 modulation in vivo, were quantified. A binding pharmacokinetic-pharmacodynamic (PK-PD) indirect response model was built to characterize the exposure-driven modulation of the target over time by MEDI7836. While the validated bioanalytical assay specification quantified the level of free target (i.e., a free IL13 assay), emerging clinical data suggested dose-dependent increase in systemic IL13 concentration over time, indicative of a total IL13 assay. The target time course was modelled as a linear combination of free target and a percentage of the drug-target complex to fit the clinical data. This novel PK-PD modelling approach integrates independent knowledge about the assay characteristics to successfully elucidate apparently complex observations.

3.
Peptides ; 140: 170532, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33744371

RESUMO

OBJECTIVES: To analyse the peptidomics of mouse enteroendocrine cells (EECs) and human gastrointestinal (GI) tissue and identify novel gut derived peptides. METHODS: High resolution nano-flow liquid chromatography mass spectrometry (LC-MS/MS) was performed on (i) flow-cytometry purified NeuroD1 positive cells from mouse and homogenised human intestinal biopsies, (ii) supernatants from primary murine intestinal cultures, (iii) intestinal homogenates from mice fed high fat diet. Candidate bioactive peptides were selected on the basis of species conservation, high expression/biosynthesis in EECs and evidence of regulated secretionin vitro. Candidate novel gut-derived peptides were chronically administered to mice to assess effects on food intake and glucose tolerance. RESULTS: A large number of peptide fragments were identified from human and mouse, including known full-length gut hormones and enzymatic degradation products. EEC-specific peptides were largely from vesicular proteins, particularly prohormones, granins and processing enzymes, of which several exhibited regulated secretion in vitro. No regulated peptides were identified from previously unknown genes. High fat feeding particularly affected the distal colon, resulting in reduced peptide levels from GCG, PYY and INSL5. Of the two candidate novel peptides tested in vivo, a peptide from Chromogranin A (ChgA 435-462a) had no measurable effect, but a progastrin-derived peptide (Gast p59-79), modestly improved glucose tolerance in lean mice. CONCLUSION: LC-MS/MS peptidomic analysis of murine EECs and human GI tissue identified the spectrum of peptides produced by EECs, including a potential novel gut hormone, Gast p59-79, with minor effects on glucose tolerance.


Assuntos
Células Enteroendócrinas/metabolismo , Gastrinas/farmacologia , Trato Gastrointestinal/metabolismo , Teste de Tolerância a Glucose/métodos , Peptídeos/metabolismo , Precursores de Proteínas/farmacologia , Proteoma/metabolismo , Magreza/tratamento farmacológico , Animais , Células Cultivadas , Glucose/metabolismo , Humanos , Masculino , Camundongos , Modelos Animais , Peptídeos/química , Proteoma/análise , Magreza/metabolismo
4.
MAbs ; 13(1): 1857100, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33397194

RESUMO

Preclinical studies of PD-L1 and CTLA-4 blockade have relied heavily on mouse syngeneic tumor models with intact immune systems, which facilitate dissection of immunosuppressive mechanisms in the tumor microenvironment. Commercially developed monoclonal antibodies (mAbs) targeting human PD-L1, PD-1, and CTLA-4 may not demonstrate cross-reactive binding to their mouse orthologs, and surrogate anti-mouse antibodies are often used in their place to inhibit these immune checkpoints. In each case, multiple choices exist for surrogate antibodies, which differ with respect to species of origin, affinity, and effector function. To develop relevant murine surrogate antibodies for the anti-human PD-L1 mAb durvalumab and the anti-human CTLA-4 mAb tremelimumab, rat/mouse chimeric or fully murine mAbs engineered for reduced effector function were developed and compared with durvalumab and tremelimumab. Characterization included determination of target affinity, in vivo effector function, pharmacokinetic profile, and anti-tumor efficacy in mouse syngeneic tumor models. Results showed that anti-PD-L1 and anti-CTLA-4 murine surrogates with pharmacologic properties similar to those of durvalumab and tremelimumab demonstrated anti-tumor activity in a subset of commonly used mouse syngeneic tumor models. This activity was not entirely dependent on antibody-dependent cellular cytotoxicity, antibody-dependent cellular phagocytosis effector function, or regulatory T-cell depletion, as antibodies engineered to lack these features showed activity in models historically sensitive to checkpoint inhibition, albeit at a significantly lower level than antibodies with intact effector function.


Assuntos
Anticorpos Monoclonais Humanizados/uso terapêutico , Anticorpos Monoclonais/uso terapêutico , Neoplasias Experimentais/tratamento farmacológico , Linfócitos T Reguladores/efeitos dos fármacos , Animais , Anticorpos Monoclonais/imunologia , Anticorpos Monoclonais Humanizados/imunologia , Antineoplásicos Imunológicos/imunologia , Antineoplásicos Imunológicos/uso terapêutico , Antígeno B7-H1/imunologia , Antígeno CTLA-4/imunologia , Linhagem Celular Tumoral , Feminino , Humanos , Estimativa de Kaplan-Meier , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Neoplasias Experimentais/imunologia , Neoplasias Experimentais/patologia , Ratos Sprague-Dawley , Linfócitos T Reguladores/imunologia , Carga Tumoral/efeitos dos fármacos , Carga Tumoral/imunologia
5.
J Orthop Res ; 39(9): 2048-2061, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-33104243

RESUMO

The Wnt pathway is upregulated in tendinopathy, affecting inflammation and tenocyte differentiation. Given its potential role in tendinopathy, this signaling pathway may be a relevant target for treatment. The current study examined the therapeutic potential of SM04755, a topical, small-molecule Wnt pathway inhibitor, for the treatment of tendinopathy using in vitro assays and animal models. In vitro, SM04755 decreased Wnt pathway activity, induced tenocyte differentiation, and inhibited catabolic enzymes and pro-inflammatory cytokines in human mesenchymal stem cells, rat tendon-derived stem cells, and human peripheral blood mononuclear cells. Evaluation of the mechanism of action of SM04755 by biochemical profiling and computational modeling identified CDC-like kinase 2 (CLK2) and dual-specificity tyrosine phosphorylation-regulated kinase 1A (DYRK1A) as molecular targets. CLK and DYRK1A inhibition by siRNA knockdown or pharmacological inhibition induced tenocyte differentiation and reduced tenocyte catabolism. In vivo, topically applied SM04755 showed therapeutically relevant exposure in tendons with low systemic exposure and no detectable toxicity in rats. Moreover, SM04755 showed reduced tendon inflammation and evidence of tendon regeneration, decreased pain, and improved weight-bearing function in rat collagenase-induced tendinopathy models compared with vehicle control. Together, these data demonstrate that CLK2 and DYRK1A inhibition by SM04755 resulted in Wnt pathway inhibition, enhanced tenocyte differentiation and protection, and reduced inflammation. SM04755 has the potential to benefit symptoms and modify disease processes in tendinopathy.


Assuntos
Tendinopatia , Via de Sinalização Wnt , Animais , Inflamação , Leucócitos Mononucleares , Ratos , Tendinopatia/tratamento farmacológico , Tendinopatia/metabolismo , Tendões
6.
Spine J ; 20(9): 1492-1502, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32413487

RESUMO

BACKGROUND CONTEXT: Abnormal Wnt signaling in intervertebral discs (IVDs) progresses degenerative disc disease (DDD) pathogenesis by impairing nucleus pulposus cell function, decreasing matrix deposition, and accelerating fibrosis. PURPOSE: This study was conducted to evaluate the effects of lorecivivint (LOR; SM04690), a small-molecule Wnt pathway inhibitor, on IVD cells and in an animal model of DDD. STUDY DESIGN: We used in vitro assays and a rat model of DDD to test the effects of LOR on nucleus pulposus cell senescence and viability, annulus fibrosus (AF) cell fibrosis, and cartilage regeneration and protection. METHODS: Wnt pathway gene expression was measured in human NP and AF cell cultures treated with LOR or DMSO (vehicle). Chondrocyte-like differentiation of rat and human NP cells, NP cell senescence and protection, and AF cell fibrosis were assessed using gene expression and immunocytochemistry. Disc and plasma pharmacokinetics were analyzed following intradiscal LOR injection in rats. In vivo effects of LOR and vehicle on AF integrity, AF/NP junction, NP cellularity and matrix, and disc height were compared using histopathology and radiography in a rat coccygeal IVD needle-puncture model of DDD. RESULTS: In NP and AF cell cultures, LOR-inhibited Wnt pathway gene expression compared with vehicle. In NP cells, LOR inhibited senescence, decreased catabolism, and induced differentiation into chondrocyte-like cells; in AF cells, LOR decreased catabolism and inhibited fibrosis. A single intradiscal LOR injection in rats resulted in therapeutic disc concentrations (~30 nM) for >180 days and minimal systemic exposure. DDD-model rats receiving LOR qualitatively demonstrated increased cartilage matrix and reduced AF lamellar disorganization and fragmentation with significantly (p<.05) improved histology scores and increased disc height compared with vehicle. CONCLUSIONS: LOR showed beneficial effects on IVD cells in vitro and reduced disease progression in a rat model of DDD compared with vehicle, suggesting that LOR may have disease-modifying therapeutic potential. CLINICAL SIGNIFICANCE: The current therapeutic options for DDD are pain management and surgical intervention; there are no approved therapies that alter the progression of DDD. Our data support advancing LOR into clinical development as an injectable, small-molecule, potential disease-modifying treatment for DDD in humans.


Assuntos
Degeneração do Disco Intervertebral , Disco Intervertebral , Animais , Imidazóis , Indazóis , Degeneração do Disco Intervertebral/tratamento farmacológico , Piridinas , Ratos , Via de Sinalização Wnt
7.
Blood Adv ; 4(8): 1792-1800, 2020 04 28.
Artigo em Inglês | MEDLINE | ID: mdl-32343799

RESUMO

Following the discovery of the JAK2V617F mutation in myeloproliferative neoplasms in 2005, fedratinib was developed as a small molecular inhibitor of JAK2. It was optimized to yield low-nanomolar activity against JAK2 (50% inhibitory concentration = 3 nM) and was identified to be selective for JAK2 relative to other JAK family members (eg, JAK1, JAK3, and TYK2). It quickly moved into clinical development with a phase 1 clinical trial opening in 2008, where a favorable impact on spleen and myelofibrosis (MF) symptom responses was reported. A phase 3 trial in JAK2 inhibitor treatment-naive MF patients followed in 2011 (JAKARTA); a phase 2 trial in MF patients resistant or intolerant to ruxolitinib followed in 2012 (JAKARTA-2). Clinical development suffered a major setback between 2013 and 2017 when the US Food and Drug Administration (FDA) placed fedratinib on clinical hold due to the development of symptoms concerning for Wernicke encephalopathy (WE) in 8 of 608 subjects (1.3%) who had received the drug. It was ultimately concluded that there was no evidence that fedratinib directly induces WE, but clear risk factors (eg, poor nutrition, uncontrolled gastrointestinal toxicity) were identified. In August 2019, the FDA approved fedratinib for the treatment of adults with intermediate-2 or high-risk MF. Notably, approval includes a "black box warning" on the risk of serious and fatal encephalopathy, including WE. FDA approval was granted on the basis of the JAKARTA studies in which the primary end points (ie, spleen and MF symptom responses) were met in ∼35% to 40% of patients (JAKARTA) and 25% to 30% of patients (JAKARTA-2), respectively.


Assuntos
Mielofibrose Primária , Adulto , Humanos , Mielofibrose Primária/tratamento farmacológico , Inibidores de Proteínas Quinases/efeitos adversos , Pirrolidinas , Sulfonamidas , Estados Unidos
8.
Bioanalysis ; 12(5): 273-284, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31975612

RESUMO

It is well accepted that chromatographic assay methods employ singlicate analysis for toxicokinetic and pharmacokinetic analysis. While conversely, it has been the norm for ligand-binding assays to be run in at least duplicate analyses, stemming mainly from concerns over inherent assay variability and reagent quality. Regulatory guidelines and guidance on bioanalytical method validation has, in the most part, recommended multiple replicates for immunoassays and this has led to the industry being comfortable and familiar with duplicate analysis. Over the last few years, the discussion on whether singlicate analysis is acceptable for ligand-binding assays has grown and the status quo is being challenged for regulated bioanalysis performed using immunoassays. Through interrogation of preclinical and clinical pharmacokinetic assay data from the European Bioanalysis Forum community, the application of a singlicate analysis strategy has shown to have no impact on toxicokinetic and pharmacokinetic parameters when compared with duplicate analysis from the same studies. Therefore, now is the time to adopt a new mindset when it comes to sample analysis for toxicokinetic and pharmacokinetic ligand-binding assays and embrace singlicate analysis in the regulated environment.


Assuntos
Bioensaio/métodos , Ligantes , Ligação Proteica/fisiologia , Europa (Continente) , Humanos
9.
Cancer Lett ; 473: 186-197, 2020 03 31.
Artigo em Inglês | MEDLINE | ID: mdl-31560935

RESUMO

The Wnt/ß-catenin signaling pathway is aberrantly activated in colorectal (CRC) and many other cancers, and novel strategies for effectively targeting it may be needed due to its complexity. In this report, SM08502, a novel small molecule in clinical development for the treatment of solid tumors, was shown to reduce Wnt pathway signaling and gene expression through potent inhibition of CDC-like kinase (CLK) activity. SM08502 inhibited serine and arginine rich splicing factor (SRSF) phosphorylation and disrupted spliceosome activity, which was associated with inhibition of Wnt pathway-related gene and protein expression. Additionally, SM08502 induced the generation of splicing variants of Wnt pathway genes, suggesting that its mechanism for inhibition of gene expression includes effects on alternative splicing. Orally administered SM08502 significantly inhibited growth of gastrointestinal tumors and decreased SRSF phosphorylation and Wnt pathway gene expression in xenograft mouse models. These data implicate CLKs in the regulation of Wnt signaling and represent a novel strategy for inhibiting Wnt pathway gene expression in cancers. SM08502 is a first-in-class CLK inhibitor being investigated in a Phase 1 clinical trial for subjects with advanced solid tumors (NCT03355066).


Assuntos
Neoplasias Colorretais/tratamento farmacológico , Inibidores de Proteínas Quinases/farmacologia , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Proteínas Tirosina Quinases/antagonistas & inibidores , Fatores de Processamento de Serina-Arginina/metabolismo , Neoplasias Gástricas/tratamento farmacológico , Via de Sinalização Wnt/efeitos dos fármacos , Processamento Alternativo/efeitos dos fármacos , Animais , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Neoplasias Colorretais/patologia , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Técnicas de Inativação de Genes , Humanos , Concentração Inibidora 50 , Camundongos , Fosforilação/efeitos dos fármacos , Inibidores de Proteínas Quinases/uso terapêutico , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Tirosina Quinases/genética , Proteínas Tirosina Quinases/metabolismo , Ratos , Neoplasias Gástricas/patologia , Via de Sinalização Wnt/genética , Ensaios Antitumorais Modelo de Xenoenxerto
10.
BMJ ; 364: l478, 2019 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-30718258
11.
Nat Commun ; 8(1): 1026, 2017 10 18.
Artigo em Inglês | MEDLINE | ID: mdl-29044101

RESUMO

The use of peptides as therapeutic agents is undergoing a renaissance with the expectation of new drugs with enhanced levels of efficacy and safety. Their clinical potential will be only fully realised once their physicochemical and pharmacokinetic properties have been precisely controlled. Here we demonstrate a reversible peptide self-assembly strategy to control and prolong the bioactivity of a native peptide hormone in vivo. We show that oxyntomodulin, a peptide with potential to treat obesity and diabetes, self-assembles into a stable nanofibril formulation which subsequently dissociates to release active peptide and produces a pharmacological effect in vivo. The subcutaneous administration of the nanofibrils in rats results in greatly prolonged exposure, with a constant oxyntomodulin bioactivity detectable in serum for at least 5 days as compared to free oxyntomodulin which is undetectable after only 4 h. Such an approach is simple, cost-efficient and generic in addressing the limitations of peptide therapeutics.


Assuntos
Obesidade/tratamento farmacológico , Oxintomodulina/farmacocinética , Hormônios Peptídicos/farmacocinética , Animais , Glucose/metabolismo , Injeções Subcutâneas , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Obesidade/metabolismo , Oxintomodulina/administração & dosagem , Oxintomodulina/sangue , Oxintomodulina/química , Hormônios Peptídicos/administração & dosagem , Hormônios Peptídicos/sangue , Hormônios Peptídicos/química , Ratos , Ratos Sprague-Dawley
12.
MAbs ; 9(1): 104-113, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27834568

RESUMO

Excessive transforming growth factor (TGF)-ß is associated with pro-fibrotic responses in lung disease, yet it also plays essential roles in tissue homeostasis and autoimmunity. Therefore, selective inhibition of excessive and aberrant integrin-mediated TGF-ß activation via targeting the α-v family of integrins is being pursued as a therapeutic strategy for chronic lung diseases, to mitigate any potential safety concerns with global TGF-ß inhibition. In this work, we reveal a novel mechanism of inhibiting TGF-ß activation utilized by an αvß8 targeting antibody, 37E1B5. This antibody blocks TGF-ß activation while not inhibiting cell adhesion. We show that an N-linked complex-type Fab glycan in H-CDR2 of 37E1B5 is directly involved in the inhibition of latent TGF-ß activation. Removal of the Fab N-glycosylation site by single amino acid substitution, or removal of N-linked glycans by enzymatic digestion, drastically reduced the antibody's ability to inhibit latency-associated peptide (LAP) and αvß8 association, and TGF-ß activation in an αvß8-mediated TGF-ß signaling reporter assay. Our results indicate a non-competitive, allosteric inhibition of 37E1B5 on αvß8-mediated TGF-ß activation. This unique, H-CDR2 glycan-mediated mechanism may account for the potent but tolerable TGF-b activation inhibition and lack of an effect on cellular adhesion by the antibody.


Assuntos
Anticorpos Monoclonais/química , Anticorpos Monoclonais/imunologia , Regiões Determinantes de Complementaridade/química , Integrinas/antagonistas & inibidores , Fator de Crescimento Transformador beta/antagonistas & inibidores , Animais , Anticorpos Monoclonais/farmacocinética , Regiões Determinantes de Complementaridade/imunologia , Glicosilação , Humanos , Fragmentos Fab das Imunoglobulinas/química , Fragmentos Fab das Imunoglobulinas/imunologia , Camundongos , Polissacarídeos/química , Processamento de Proteína Pós-Traducional
13.
Hand (N Y) ; 9(3): 274-81, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25191156

RESUMO

PURPOSE: The purpose of this study was to report on the injury patterns and outcomes of a series of patients treated at our institution between the years 1983 and 2010 who were injured by rings worn on their finger. The series included typical ring avulsion injuries as well as all other injuries caused by rings. METHODS: Retrospective chart review was conducted on 33 patients with ring injuries treated by the senior author and colleagues. Eight cases were classified as Urbaniak class I, 13 class II, and 12 class III. RESULTS: Satisfactory finger motion occurred with salvage of fingers in which no damage occurred to the proximal phalanx or flexor digitorum sublimus or profundus tendons. All patients with flexor tendon injury or proximal phalangeal fracture or both had loss of PIPJ motion and total active motion as compared to class II injuries without tendon and bone involvement. Four class III injuries were treated with replantation. One failed requiring revision amputation at the metacarpalphalangeal joint level due to ischemia. The remaining eight were treated by primary amputation. CONCLUSIONS: As a guideline to digit salvage with ring injuries, the authors propose accurately documenting and basing treatment on all injured structures. Particular attention should be given to fractures of the proximal phalanx and laceration of the flexor digitorum sublimus and profundus tendons, as injury to these structures led to significant loss in mobility of the finger in this series. While some current guidelines advise revascularization of class II ring avulsion injuries, our series suggests caution in anticipating good results with sublimus or profundus tendon laceration and proximal phalanx fracture. If the profundus tendon only is lacerated, particularly in zone I injuries, results of finger salvage may still be acceptable, but associated (distal interphalangeal joint) DIPJ injury may require K-wire stabilization and later fusion. Replantation in class III injuries, while possible, is warranted only in select situations (patient-specific and cultural factors).

14.
N C Med J ; 73(5): 398-400, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23189437

RESUMO

There is solid empirical evidence for a positive relationship between economic development and health outcomes. A successful strategy for promoting economic growth in North Carolina would include reforms of the state's education, infrastructure, tax, and regulatory policies.


Assuntos
Desenvolvimento Econômico , Emprego , Competição Econômica , Humanos , Investimentos em Saúde , North Carolina
17.
J Immunol Methods ; 352(1-2): 1-12, 2010 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-19895813

RESUMO

TGN1412 is a "superagonistic" CD28 monoclonal antibody (IgG4) that caused serious adverse events at its first time in human clinical trial. In the present study, different in vitro methods for detecting and quantifying unwanted pro-inflammatory activity of therapeutic monoclonal antibodies (mAbs) such as TGN1412 are described. The antibody of interest is immobilised by wet-coating or air-drying onto polypropylene or polystyrene 96-well plates prior to the addition of human peripheral blood mononuclear cells (PBMCs). The cells are incubated for 16-24h with the immobilised antibody which allows the accumulation of pro-inflammatory cytokines, quantified by enzyme-linked immunoabsorbent assay (ELISA), in response to the antibody. Cytokine responses stimulated by TGN1412 immobilised by air-drying onto polypropylene and polystyrene plates were much larger than responses to TGN1412 wet-coated onto polypropylene and polystyrene plates, respectively. In additional experiments with other mAbs associated with clinical reactions, air-dried mAbs stimulated larger tumour necrosis factor-alpha (TNF) responses than antibodies added in aqueous phase. Also, TGN1412 air-dried onto plastic plates stimulated large proliferative responses of 3-day cultures of lymphocytes. It was concluded that immobilising mAbs by air-drying offers a useful in vitro method for detecting and quantifying pro-inflammatory activities of therapeutic mAbs.


Assuntos
Anticorpos Monoclonais/farmacologia , Antígenos CD28/imunologia , Avaliação de Medicamentos/métodos , Ensaio de Imunoadsorção Enzimática , Leucócitos Mononucleares/efeitos dos fármacos , Anticorpos Monoclonais Humanizados , Ligação Competitiva , Antígenos CD28/metabolismo , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Humanos , Imunoterapia Ativa , Técnicas In Vitro , Leucócitos Mononucleares/imunologia , Ativação Linfocitária/efeitos dos fármacos , Ativação Linfocitária/imunologia , Proteínas Recombinantes de Fusão/metabolismo , Fator de Necrose Tumoral alfa/metabolismo
19.
Curr Top Med Chem ; 8(10): 905-21, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18673174

RESUMO

Chronic myelogenous leukemia (CML) is a hematological stem cell disorder caused by increased and unregulated growth of myeloid cells in the bone marrow, and the accumulation of excessive white blood cells. Abelson tyrosine kinase (ABL) is a non-receptor tyrosine kinase involved in cell growth and proliferation and is usually under tight control. However, 95% of CML patients have the ABL gene from chromosome 9 fused with the breakpoint cluster (BCR) gene from chromosome 22, resulting in a short chromosome known as the Philadelphia chromosome. This Philadelphia chromosome is responsible for the production of BCR-ABL, a constitutively active tyrosine kinase that causes uncontrolled cellular proliferation. An ABL inhibitor, imatinib, was approved by the FDA for the treatment of CML, and is currently used as first line therapy. However, a high percentage of clinical relapse has been observed due to long term treatment with imatinib. A majority of these relapsed patients have several point mutations at and around the ATP binding pocket of the ABL kinase domain in BCR-ABL. In order to address the resistance of mutated BCR-ABL to imatinib, 2(nd) generation inhibitors such as dasatinib, and nilotinib were developed. These compounds were approved for the treatment of CML patients who are resistant to imatinib. All of the BCR-ABL mutants are inhibited by the 2(nd) generation inhibitors with the exception of the T315I mutant. Several 3(rd) generation inhibitors such as AP24534, VX-680 (MK-0457), PHA-739358, PPY-A, XL-228, SGX-70393, FTY720 and TG101113 are being developed to target the T315I mutation. The early results from these compounds are encouraging and it is anticipated that physicians will have additional drugs at their disposal for the treatment of patients with the mutated BCR-ABL-T315I. The success of these inhibitors has greater implication not only in CML, but also in other diseases driven by kinases where the mutated gatekeeper residue plays a major role.


Assuntos
Antineoplásicos/farmacologia , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Proteínas Proto-Oncogênicas c-abl/antagonistas & inibidores , Proteínas Proto-Oncogênicas c-abl/genética , Antineoplásicos/química , Antineoplásicos/uso terapêutico , Humanos , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Estrutura Molecular , Relação Estrutura-Atividade
20.
J Clin Invest ; 118(6): 2337-46, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18483622

RESUMO

Retinal and choroidal vascular diseases, with their associated abnormalities in vascular permeability, account for the majority of patients with vision loss in industrialized nations. VEGF is upregulated in ischemic retinopathies such as diabetes and is known to dramatically alter vascular permeability in a number of nonocular tissues via Src kinase-regulated signaling pathways. VEGF antagonists are currently in clinical use for treating the new blood vessels and retinal edema associated with neovascular eye diseases, but such therapies require repeated intraocular injections. We have found that vascular leakage following intravitreal administration of VEGF in mice was abolished by systemic or topical delivery of what we believe is a novel VEGFR2/Src kinase inhibitor; this was confirmed in rabbits. The relevance of Src inhibition to VEGF-associated alterations in vascular permeability was further substantiated by genetic studies in which VEGF injection or laser-induced vascular permeability failed to augment retinal vascular permeability in Src-/- and Yes-/- mice (Src and Yes are ubiquitously expressed Src kinase family members; Src-/- and Yes-/- mice lacking expression of these kinases show no vascular leak in response to VEGF). These findings establish a role for Src kinase in VEGF-mediated retinal vascular permeability and establish a potentially safe and painless topically applied therapeutic option for treating vision loss due to neovascular-associated retinal edema.


Assuntos
Permeabilidade Capilar , Inibidores Enzimáticos/farmacologia , Retina/patologia , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/antagonistas & inibidores , Animais , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Transgênicos , Modelos Biológicos , Permeabilidade , Coelhos , Transdução de Sinais , Fatores de Tempo , Fator A de Crescimento do Endotélio Vascular/metabolismo , Quinases da Família src/metabolismo
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