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1.
J Orthod ; 50(1): 28-38, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-35657110

RESUMO

INTRODUCTION: Across the United Kingdom (UK), National Health Service (NHS) orthodontic treatment is commissioned differently across the devolved nations. There is a relative paucity in the literature describing the way in which the orthodontic services in each country are commissioned and treatment outcomes measured. OBJECTIVE: To highlight the differences in the following: commissioning of primary care orthodontic services across the UK; assessment of treatment outcomes; and the potential impacts these differences have on contractors, performers and patient care. MATERIALS AND METHODS: Data were collected using an online mixed-methods approach. Systematic content analysis was used to extract the required information from the websites and guidance documents of orthodontic service providers, which was then catalogued and verified electronically by senior dental advisors in the four devolved UK nations. RESULTS: The Index of Orthodontic Treatment Need (IOTN) is a mandatory needs assessment tool used across all four nations, with an agreed minimum threshold of a dental health component (DHC) score of 3 and an aesthetic component (AC) score of 6 for NHS treatment. While the peer assessment rating (PAR) is the most utilised method of assessing post-treatment outcomes, it is applied differently by each country. CONCLUSION: While NHS orthodontic services across the UK share mutual elements of service delivery, there are significant differences in the prior approval process and assessment of treatment outcomes. More research is required to assess the economic feasibility of orthodontic treatment from the associated treatment outcomes.


Assuntos
Má Oclusão , Humanos , Má Oclusão/terapia , Ortodontia Corretiva , Medicina Estatal , Índice de Necessidade de Tratamento Ortodôntico , Reino Unido , Resultado do Tratamento , Estética Dentária
3.
Clin Cancer Res ; 30(10): 2011-2016, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38441576

RESUMO

On April 3, 2023, the FDA granted accelerated approval to enfortumab vedotin-ejfv (EV) plus pembrolizumab for treatment of patients with locally advanced or metastatic urothelial carcinoma who are ineligible for cisplatin-containing chemotherapy. Substantial evidence of effectiveness was obtained from EV-103/KEYNOTE-869 (NCT03288545), a multicohort study. Across cohorts, a total of 121 patients received EV 1.25 mg/kg (maximum of 125 mg) intravenously on days 1 and 8 of a 21-day cycle plus pembrolizumab 200 mg intravenously on day 1 of each 21-day cycle until disease progression or unacceptable toxicity. The major efficacy outcome measures were objective response rate (ORR) and duration of response (DoR), determined by blinded independent central review using RECIST v1.1. The confirmed ORR in 121 patients was 68% (95% confidence interval, 59-76), including 12% with complete responses. The median DoR for the 82 responders was 22 months (range: 1+ to 46+). The safety profile of the combination comprised adverse reactions expected to occur with the corresponding monotherapies, but with overall increased frequency of adverse reactions, including skin toxicity, pneumonitis, and peripheral neuropathy. The article summarizes the data and the FDA thought process supporting accelerated approval of EV + pembrolizumab, as well as additional exploratory analyses conducted by the FDA.


Assuntos
Anticorpos Monoclonais Humanizados , Anticorpos Monoclonais , Protocolos de Quimioterapia Combinada Antineoplásica , Aprovação de Drogas , United States Food and Drug Administration , Humanos , Anticorpos Monoclonais Humanizados/administração & dosagem , Anticorpos Monoclonais Humanizados/efeitos adversos , Anticorpos Monoclonais Humanizados/uso terapêutico , Estados Unidos , Masculino , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Idoso , Feminino , Anticorpos Monoclonais/administração & dosagem , Anticorpos Monoclonais/efeitos adversos , Anticorpos Monoclonais/uso terapêutico , Pessoa de Meia-Idade , Cisplatino/administração & dosagem , Cisplatino/efeitos adversos , Cisplatino/uso terapêutico , Idoso de 80 Anos ou mais , Neoplasias da Bexiga Urinária/tratamento farmacológico , Neoplasias da Bexiga Urinária/patologia , Carcinoma de Células de Transição/tratamento farmacológico , Carcinoma de Células de Transição/patologia , Neoplasias Urológicas/tratamento farmacológico , Neoplasias Urológicas/patologia , Resultado do Tratamento
4.
J Clin Oncol ; 42(14): 1687-1698, 2024 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-38484203

RESUMO

PURPOSE: We performed a pooled analysis of multiple trials of poly(ADP-ribose) polymerase inhibitors (PARPi) in metastatic castration-resistant prostate cancer (mCRPC) to investigate the efficacy of PARPi in each individual homologous recombination repair (HRR) mutated (m) gene. PATIENTS AND METHODS: We pooled patient-level data from trials of PARPi in mCRPC that reported mutation status in individual HRR genes. Any HRR gene with available data across all the randomized trials of PARPi in first-line mCRPC was selected. The hazard ratios (HRs; 95% CI) for radiographic progression-free survival (rPFS; by blinded independent review) and overall survival (OS) of a PARPi plus an androgen receptor pathway inhibitor (ARPI) relative to placebo plus an ARPI in the pool of three randomized trials in first-line mCRPC were calculated using Kaplan-Meier estimates and a Cox proportional hazards model. RESULTS: In ATMm (N = 268), rPFS HR was 1.05 (0.74 to 1.49) and OS HR was 1.18 (0.82 to 1.71). In BRCA1m (N = 64), rPFS HR was 0.51 (0.23 to 1.1) and OS HR was 0.74 (0.34 to 1.61). In BRCA2m (N = 422), rPFS HR was 0.31 (0.23 to 0.42) and OS HR was 0.66 (0.49 to 0.89). In CDK12m (N = 164), rPFS HR was 0.50 (0.32 to 0.80) and OS HR was 0.63 (0.39 to 0.99). In CHEK2m (N = 172), rPFS HR was 1.06 (0.67 to 1.66) and OS HR was 1.53 (0.95 to 2.46). In PALB2m (N = 41) rPFS HR was 0.52 (0.23 to 1.17) and OS HR was 0.78 (0.34 to 1.8). CONCLUSION: In this pooled analysis, benefit from PARPi appeared greatest for patients with BRCA1m, BRCA2m, CDK12m, and PALB2m. Given limitations of this exploratory analysis, the apparent lack of benefit from PARPi in patients with CHEK2m or ATMm should be further explored in future clinical trials.


Assuntos
Proteína BRCA2 , Mutação , Inibidores de Poli(ADP-Ribose) Polimerases , Neoplasias de Próstata Resistentes à Castração , Ensaios Clínicos Controlados Aleatórios como Assunto , Reparo de DNA por Recombinação , Humanos , Neoplasias de Próstata Resistentes à Castração/tratamento farmacológico , Neoplasias de Próstata Resistentes à Castração/genética , Neoplasias de Próstata Resistentes à Castração/patologia , Inibidores de Poli(ADP-Ribose) Polimerases/uso terapêutico , Masculino , Reparo de DNA por Recombinação/genética , Proteína BRCA2/genética , Proteína BRCA1/genética , Estados Unidos , Quinase do Ponto de Checagem 2/genética , Quinases Ciclina-Dependentes/genética , Quinases Ciclina-Dependentes/antagonistas & inibidores , Proteínas Mutadas de Ataxia Telangiectasia/genética , Proteína do Grupo de Complementação N da Anemia de Fanconi/genética , Intervalo Livre de Progressão , Antagonistas de Receptores de Andrógenos/uso terapêutico , Idoso , Receptores Androgênicos/genética , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico
5.
Nucleic Acids Res ; 39(6): 2458-69, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21030439

RESUMO

Long-term survival still eludes most patients with leukemia and non-Hodgkin's lymphoma. No approved therapies target the hallmark of the B cell, its mIgM, also known as the B-cell receptor (BCR). Aptamers are small oligonucleotides that can specifically bind to a wide range of target molecules and offer some advantages over antibodies as therapeutic agents. Here, we report the rational engineering of aptamer TD05 into multimeric forms reactive with the BCR that may be useful in biomedical applications. Systematic truncation of TD05 coupled with modification with locked nucleic acids (LNA) increased conformational stability and nuclease resistance. Trimeric and tetrameric versions with optimized polyethyleneglycol (PEG) linker lengths exhibited high avidity at physiological temperatures both in vitro and in vivo. Competition and protease studies showed that the multimeric, optimized aptamer bound to membrane-associated human mIgM, but not with soluble IgM in plasma, allowing the possibility of targeting leukemias and lymphomas in vivo. The B-cell specificity of the multivalent aptamer was confirmed on lymphoma cell lines and fresh clinical leukemia samples. The chemically engineered aptamers, with significantly improved kinetic and biochemical features, unique specificity and desirable pharmacological properties, may be useful in biomedical applications.


Assuntos
Aptâmeros de Nucleotídeos/química , Leucemia de Células B/metabolismo , Linfoma de Células B/metabolismo , Receptores de Antígenos de Linfócitos B/metabolismo , Animais , Aptâmeros de Nucleotídeos/metabolismo , Linhagem Celular Tumoral , Feminino , Humanos , Imunoglobulina M/metabolismo , Camundongos , Camundongos Nus , Oligonucleotídeos/química
6.
Transl Vis Sci Technol ; 12(1): 28, 2023 01 03.
Artigo em Inglês | MEDLINE | ID: mdl-36716040

RESUMO

Purpose: To optimize a virtual reality (VR) orientation and mobility (O&M) test of functional vision in patients with inherited retinal degenerations (IRDs). Methods: We developed an O&M test using commercially available VR hardware and custom-generated software. Normally sighted subjects (n = 20, ages = 14-67 years) and patients with IRDs (n = 29, ages = 15-63 years) participated. Individuals followed a dim red arrow path to a "course exit," while trying to identify nine obstacles adjacent to, or directly in their path. Dark-adapted subjects completed 35 randomly selected VR courses at increasing luminances, twice per luminance step, binocularly, and uni-ocularly. Performance was graded automatically by the software. Patients with IRD completed a modified Visual Function Questionnaire (VFQ). Results: Normally sighted subjects identified approximately 50% of the obstacles at the dimmest course luminance. Except for two patients with IRD with poor vision, all patients were able to complete the test, although they required brighter (by >2 log units) luminances to identify 50% of the obstacles. In a single-luminance screening test in which normal subjects detected at least eight of nine objects, most patients with IRD underperformed; their performance related to disease severity, as measured by visual acuity, kinetic visual field extent, and VFQ scores. Test-retest differences in object detection were similar to the differences between the two eyes (±2 SD = ±2 objects). Conclusions: This VR-O&M test was able to distinguish subjects with IRDs from normal subjects reliably and reproducibly. Translational Relevance: This easily implemented, flexible, and objectively scored VR-O&M test promises to become a useful tool to assess the impact that IRDs and their treatments have on functional vision.


Assuntos
Degeneração Retiniana , Realidade Virtual , Humanos , Adolescente , Adulto Jovem , Adulto , Pessoa de Meia-Idade , Idoso , Acuidade Visual , Visão Ocular , Campos Visuais
7.
JID Innov ; 3(2): 100181, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36960318

RESUMO

The documentation of the change in the number and appearance of pigmented cutaneous lesions over time is critical to the early detection of skin cancers and may provide preliminary signals of efficacy in early-phase therapeutic prevention trials for melanoma. Despite substantial progress in computer-aided diagnosis of melanoma, automated methods to assess the evolution of lesions are relatively undeveloped. This report describes the development and narrow validation of mathematical algorithms to register nevi between sequential digital photographs of large areas of skin and to align images for improved detection and quantification of changes. Serial posterior truncal photographs from a pre-existing database were processed and analyzed by the software, and the results were evaluated by a panel of clinicians using a separate Extensible Markup Language‒based application. The software had a high sensitivity for the detection of cutaneous lesions as small as 2 mm. The software registered lesions accurately, with occasional errors at the edges of the images. In one pilot study with 17 patients, the use of the software enabled clinicians to identify new and/or enlarged lesions in 3‒11 additional patients versus the unregistered images. Automated quantification of size change performed similarly to that of human raters. These results support the further development and broader validation of this technique.

8.
Proc Natl Acad Sci U S A ; 106(9): 3585-90, 2009 Mar 03.
Artigo em Inglês | MEDLINE | ID: mdl-19208811

RESUMO

High-throughput screening (HTS) assays used in drug discovery frequently use reporter enzymes such as firefly luciferase (FLuc) as indicators of target activity. An important caveat to consider, however, is that compounds can directly affect the reporter, leading to nonspecific but highly reproducible assay signal modulation. In rare cases, this activity appears counterintuitive; for example, some FLuc inhibitors, acting through posttranslational Fluc reporter stabilization, appear to activate gene expression. Previous efforts to characterize molecules that influence luciferase activity identified a subset of 3,5-diaryl-oxadiazole-containing compounds as FLuc inhibitors. Here, we evaluate a number of compounds with this structural motif for activity against FLuc. One such compound is PTC124 {3-[5-(2-fluorophenyl)-1,2,4-oxadiazol-3-yl]benzoic acid}, a molecule originally identified in a cell-based FLuc assay as having nonsense codon suppression activity [Welch EM, et al., Nature (2007) 447:87-91]. We find that the potency of FLuc inhibition for the tested compounds strictly correlates with their activity in a FLuc reporter cell-based nonsense codon assay, with PTC124 emerging as the most potent FLuc inhibitor (IC(50) = 7 +/- 1 nM). However, these compounds, including PTC124, fail to show nonsense codon suppression activity when Renilla reniformis luciferase (RLuc) is used as a reporter and are inactive against the RLuc enzyme. This suggests that the initial discovery of PTC124 may have been biased by its direct effect on the FLuc reporter, implicating firefly luciferase as a molecular target of PTC124. Our results demonstrate the value of understanding potential interactions between reporter enzymes and chemical compounds and emphasize the importance of implementing the appropriate control assays before interpreting HTS results.


Assuntos
Códon sem Sentido/genética , Regulação para Baixo/efeitos dos fármacos , Inibidores Enzimáticos/farmacologia , Luciferases de Vaga-Lume/análise , Luciferases de Vaga-Lume/metabolismo , Oxidiazóis/farmacologia , Animais , Ativação Enzimática , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/química , Vaga-Lumes/enzimologia , Vaga-Lumes/genética , Genes Reporter/genética , Inibidores de Histona Desacetilases , Histona Desacetilases/metabolismo , Luciferases de Vaga-Lume/genética , Estrutura Molecular , Oxidiazóis/síntese química , Oxidiazóis/química , Especificidade por Substrato
9.
Cancer Chemother Pharmacol ; 88(4): 643-654, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34164713

RESUMO

PURPOSE: We investigated the combination of tivantinib, a c-MET tyrosine kinase inhibitor (TKI), and bevacizumab, an anti-VEGF-A antibody. METHODS: Patients with advanced solid tumors received bevacizumab (10 mg/kg intravenously every 2 weeks) and escalating doses of tivantinib (120-360 mg orally twice daily). In addition to safety and preliminary efficacy, we evaluated pharmacokinetics of tivantinib and its metabolites, as well as pharmacodynamic biomarkers in peripheral blood and skin. RESULTS: Eleven patients received the combination treatment, which was generally well tolerated. The main dose-limiting toxicity was grade 3 hypertension, which was observed in four patients. Other toxicities included lymphopenia and electrolyte disturbances. No exposure-toxicity relationship was observed for tivantinib or metabolites. No clinical responses were observed. Mean levels of the serum cytokine bFGF increased (p = 0.008) after the bevacizumab-only lead-in and decreased back to baseline (p = 0.047) after addition of tivantinib. Tivantinib reduced levels of both phospho-MET (7/11 patients) and tubulin (4/11 patients) in skin. CONCLUSIONS: The combination of tivantinib and bevacizumab produced toxicities that were largely consistent with the safety profiles of the individual drugs. The study was terminated prior to establishment of the recommended phase II dose (RP2D) due to concerns regarding the mechanism of tivantinib, as well as lack of clinical efficacy seen in this and other studies. Tivantinib reversed the upregulation of bFGF caused by bevacizumab, which has been considered a potential mechanism of resistance to therapies targeting the VEGF pathway. The findings from this study suggest that the mechanism of action of tivantinib in humans may involve inhibition of both c-MET and tubulin expression. TRIAL REGISTRATION: NCT01749384 (First posted 12/13/2012).


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Neoplasias/tratamento farmacológico , Proteínas Proto-Oncogênicas c-met/antagonistas & inibidores , Tubulina (Proteína)/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/farmacocinética , Bevacizumab/administração & dosagem , Relação Dose-Resposta a Droga , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias/patologia , Pirrolidinonas/administração & dosagem , Quinolinas/administração & dosagem , Resultado do Tratamento
10.
Evolution ; 74(10): 2425-2426, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32827152

RESUMO

Do local parasite assemblages correlate with the divergence of sexual signals across subspecies? Hund et al. found that locally relevant sexual signals were associated with the most costly local parasites, indicating sexual signals communicate information about local parasite costs and suggesting a potential role in speciation.


Assuntos
Parasitos , Animais
11.
Bioorg Med Chem Lett ; 19(13): 3686-92, 2009 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-19464886

RESUMO

An expansion of structure-activity studies on a series of substituted 7H-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazine PDE4 inhibitors and the introduction of a related [1,2,4]triazolo[4,3-b]pyridazine based inhibitor of PDE4 is presented. The development of SAR included strategic incorporation of known substituents on the critical catachol diether moiety of the 6-phenyl appendage on each heterocyclic core. From these studies, (R)-3-(2,5-dimethoxyphenyl)-6-(4-methoxy-3-(tetrahydrofuran-3-yloxy)phenyl)-7H-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazine (10) and (R)-3-(2,5-dimethoxyphenyl)-6-(4-methoxy-3-(tetrahydrofuran-3-yloxy)phenyl)-[1,2,4]triazolo[4,3-b]pyridazine (18) were identified as highly potent PDE4A inhibitors. Each of these analogues was submitted across a panel of 21 PDE family members and was shown to be highly selective for PDE4 isoforms (PDE4A, PDE4B, PDE4C, PDE4D). Both 10 and 18 were then evaluated in divergent cell-based assays to assess their relevant use as probes of PDE4 activity. Finally, docking studies with selective ligands (including 10 and 18) were undertaken to better understand this chemotypes ability to bind and inhibit PDE4 selectively.


Assuntos
Furanos/química , Inibidores da Fosfodiesterase 4 , Inibidores de Fosfodiesterase/química , Piridazinas/química , Tiadiazinas/química , Triazóis/química , Sítios de Ligação , Linhagem Celular , Simulação por Computador , Nucleotídeo Cíclico Fosfodiesterase do Tipo 4/metabolismo , Furanos/síntese química , Furanos/farmacologia , Humanos , Inibidores de Fosfodiesterase/síntese química , Inibidores de Fosfodiesterase/farmacologia , Isoformas de Proteínas/antagonistas & inibidores , Isoformas de Proteínas/metabolismo , Piridazinas/síntese química , Piridazinas/farmacologia , Relação Estrutura-Atividade , Tiadiazinas/síntese química , Tiadiazinas/farmacologia , Triazóis/síntese química , Triazóis/farmacologia
12.
Br Dent J ; 227(6): 497-502, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31562450

RESUMO

Background Conscious dental sedation is commissioned by NHS England for patients who are unable to accept dental treatment under local anaesthetic and behavioural techniques alone. Dental sedation provided by NHS England is carried out on a referral basis but this can be carried out in a primary or secondary care setting. This paper reports a study carried out to improve NHS dental services by supporting the work of multiple NHS England area teams in reviews of sedation services.Aim The aim of this paper is to identify variations in the provision of sedation services by NHS providers across England and explore possible factors affecting this variation.Method The project makes use of the recently developed NHS Business Services Authority (BSA) national public health data set, which Public Health England has developed in association with the BSA.Results Variations in population experience of sedation in England have been graphically demonstrated using a comprehensive BSA data set which captures all general dental service and public dental service (GDS/PDS) activity for a two-year period. There are wide and significant variations in population experience of sedation across England.Conclusion The variations in population experience of sedation across England are difficult to explain on purely clinical grounds.


Assuntos
Anestesia Dentária , Medicina Estatal , Sedação Consciente , Assistência Odontológica , Inglaterra , Humanos
13.
J Nucl Med ; 57(10): 1576-1582, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27127217

RESUMO

Glioblastoma is characterized by an aggressive and aberrant vascular network that promotes tumor progression and hinders effective treatment; the median survival is 16 mo despite standard-of-care therapies. There is a need to improve therapeutic options for this disease. We hypothesized that antibody targeting of the vascular endothelium of glioblastoma with cytotoxic short-range, high-energy α-particles would be an effective therapeutic approach. METHODS: E4G10, an antibody directed at an epitope of monomeric vascular endothelium cadherin that is expressed in tumor neovasculature and on endothelial progenitor cells in the bone marrow, was labeled with α-particle-emitting 225Ac. Pharmacokinetic studies investigated the tissue distribution and blood clearance of the 225Ac-E4G10 radioimmunoconstruct in a transgenic Nestin-tumor virus A (Ntva) mouse model of high-grade glioblastoma. Histologic analysis was used to demonstrate local therapeutic effects in treated brain tumor sections. Radioimmunotherapy with 225Ac-E4G10 was performed in Ntva mice to assess overall survival alone and in combination with temozolomide, the standard-of-care chemotherapeutic agent. RESULTS: 225Ac-E4G10 was found to accumulate in tissues expressing the target antigen. Antivascular α-particle therapy of glioblastoma in the transgenic Ntva model resulted in significantly improved survival compared with controls and potent control of tumor growth. Adding the chemotherapeutic temozolomide to the treatment increased survival to 30 d (vs. 9 d for vehicle-treated animals). Histologic analyses showed a remodeled glioblastoma vascular microenvironment. CONCLUSION: Targeted α-particle antivascular therapy is shown for the first time to be effective in increasing overall survival in a solid tumor in a clinically relevant transgenic glioblastoma mouse model.


Assuntos
Vasos Sanguíneos/efeitos da radiação , Neoplasias Encefálicas/irrigação sanguínea , Neoplasias Encefálicas/radioterapia , Glioblastoma/irrigação sanguínea , Glioblastoma/radioterapia , Radioimunoterapia/métodos , Actínio , Partículas alfa/uso terapêutico , Animais , Anticorpos Monoclonais/química , Anticorpos Monoclonais/farmacocinética , Anticorpos Monoclonais/uso terapêutico , Vasos Sanguíneos/metabolismo , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/patologia , Linhagem Celular Tumoral , Glioblastoma/metabolismo , Glioblastoma/patologia , Humanos , Camundongos , Gradação de Tumores , Radioquímica , Dosagem Radioterapêutica
14.
J Nucl Med ; 57(11): 1771-1777, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27261519

RESUMO

Tumors escape antiangiogenic therapy by activation of proangiogenic signaling pathways. Bevacizumab is approved for the treatment of recurrent glioblastoma, but patients inevitably develop resistance to this angiogenic inhibitor. We previously investigated targeted α-particle therapy with 225Ac-E4G10 as an antivascular approach and showed increased survival and tumor control in a high-grade transgenic orthotopic glioblastoma model. Here, we investigated changes in tumor vascular morphology and functionality caused by 225Ac-E4G10. METHODS: We investigated remodeling of the tumor microenvironment in transgenic Ntva glioblastoma mice using a therapeutic 7.4-kBq dose of 225Ac-E4G10. Immunofluorescence and immunohistochemical analyses imaged morphologic changes in the tumor blood-brain barrier microenvironment. Multicolor flow cytometry quantified the endothelial progenitor cell population in the bone marrow. Diffusion-weighted MR imaged functional changes in the tumor vascular network. RESULTS: The mechanism of drug action is a combination of remodeling of the glioblastoma vascular microenvironment, relief of edema, and depletion of regulatory T and endothelial progenitor cells. The primary remodeling event is the reduction of both endothelial and perivascular cell populations. Tumor-associated edema and necrosis were lessened, resulting in increased perfusion and reduced diffusion. Pharmacologic uptake of dasatinib into tumor was enhanced after α-particle therapy. CONCLUSION: Targeted antivascular α-particle radiation remodels the glioblastoma vascular microenvironment via a multimodal mechanism of action and provides insight into the vascular architecture of platelet-derived growth factor-driven glioblastoma.


Assuntos
Partículas alfa/uso terapêutico , Anticorpos Monoclonais/uso terapêutico , Neoplasias Encefálicas/radioterapia , Glioblastoma/radioterapia , Microambiente Tumoral , Animais , Barreira Hematoencefálica , Neoplasias Encefálicas/irrigação sanguínea , Neoplasias Encefálicas/patologia , Dasatinibe/farmacocinética , Glioblastoma/irrigação sanguínea , Glioblastoma/patologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Células-Tronco Neoplásicas/efeitos da radiação , Linfócitos T Reguladores/imunologia
15.
J Nucl Med ; 55(9): 1492-8, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24982438

RESUMO

UNLABELLED: Targeted α-particle radiation using the radioisotope (225)Ac is a promising form of therapy for various types of cancer. Historic obstacles to the use of (225)Ac have been the difficulty in finding suitable chelators to stably attach it to targeting vehicles such as peptides and monoclonal antibodies, the low specific activities of the products, and the lack of cost-effective radiolabeling procedures. We initially solved the first problem with a procedure involving 2 chemical steps that has been used as a standard in preclinical and clinical studies. However, this procedure involves the loss of 90% of the input (225)Ac. A more efficient, economical process is needed to facilitate the more widespread use of (225)Ac. METHODS: We conjugated representative antibodies with 2 forms of DOTA as well as other chelators as controls. We developed conditions to radiolabel these constructs in 1 chemical step and characterized their stability, immunoreactivity, biodistribution, and therapeutic efficacy in healthy and tumor-bearing mice. RESULTS: DOTA-antibody constructs were labeled to a wide range of specific activities in 1 chemical step at 37°C. Radiochemical yields were approximately 10-fold higher, and specific activities were up to 30-fold higher than with the previous approach. The products retained immunoreactivity and were stable to serum challenge in vitro and in mice. Labeling kinetics of DOTA-antibody constructs linked through a benzyl isothiocyanate linkage were more favorable than those linked through an N-hydroxysuccinimide linkage. Tissue distribution was similar but not identical between the constructs. The constructs produced specific therapeutic responses in a mouse model of acute myeloid leukemia. CONCLUSION: We have characterized an efficient, 1-step radiolabeling method that produces stable, therapeutically active conjugates of antibodies with (225)Ac at high specific activity. We propose that this technology greatly expands the possible clinical applications of (225)Ac monoclonal antibodies.


Assuntos
Actínio/uso terapêutico , Partículas alfa/uso terapêutico , Anticorpos Monoclonais/uso terapêutico , Marcação por Isótopo , Neoplasias Experimentais/radioterapia , Radioimunoterapia/métodos , Animais , Estabilidade de Medicamentos , Camundongos , Camundongos Endogâmicos BALB C , Controle de Qualidade , Distribuição Tecidual
16.
Invest Ophthalmol Vis Sci ; 55(10): 6381-97, 2014 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-25190651

RESUMO

PURPOSE: We characterized retinal structure in patients and carriers of choroideremia using adaptive optics and other high resolution modalities. METHODS: A total of 57 patients and 18 carriers of choroideremia were imaged using adaptive optics scanning light ophthalmoscopy (AOSLO), optical coherence tomography (OCT), autofluorescence (AF), and scanning light ophthalmoscopy (SLO). Cone density was measured in 59 eyes of 34 patients where the full cone mosaic was observed. RESULTS: The SLO imaging revealed scalloped edges of RPE atrophy and large choroidal vessels. The AF imaging showed hypo-AF in areas of degeneration, while central AF remained present. OCT images showed outer retinal tubulations and thinned RPE/interdigitation layers. The AOSLO imaging revealed the cone mosaic in central relatively intact retina, and cone density was either reduced or normal at 0.5 mm eccentricity. The border of RPE atrophy showed abrupt loss of the cone mosaic at the same location. The AF imaging in comparison with AOSLO showed RPE health may be compromised before cone degeneration. Other disease features, including visualization of choroidal vessels, hyper-reflective clumps of cones, and unique retinal findings, were tabulated to show the frequency of occurrence and model disease progression. CONCLUSIONS: The data support the RPE being one primary site of degeneration in patients with choroideremia. Photoreceptors also may degenerate independently. High resolution imaging, particularly AOSLO in combination with OCT, allows single cell analysis of disease in choroideremia. These modalities promise to be useful in monitoring disease progression, and in documenting the efficacy of gene and cell-based therapies for choroideremia and other diseases as these therapies emerge. (ClinicalTrials.gov number, NCT01866371.).


Assuntos
Coroideremia/diagnóstico , Técnicas de Diagnóstico Oftalmológico/instrumentação , Óptica e Fotônica , Células Fotorreceptoras Retinianas Cones/patologia , Tomografia de Coerência Óptica/instrumentação , Adolescente , Adulto , Estruturas Celulares , Criança , Coroideremia/fisiopatologia , Desenho de Equipamento , Angiofluoresceinografia/instrumentação , Seguimentos , Fundo de Olho , Humanos , Pessoa de Meia-Idade , Oftalmoscópios , Oftalmoscopia/métodos , Reprodutibilidade dos Testes , Acuidade Visual , Adulto Jovem
17.
Cell Rep ; 8(4): 1077-92, 2014 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-25131208

RESUMO

γ-Secretase is composed of four proteins that are obligatory for protease activity: presenilin, nicastrin, Aph1, and Pen-2. Despite the progress toward understanding the function of these individual subunits, there is no information available pertaining to the modulation of γ-secretase in response to environmental changes in cells. Here, we show that hypoxia upregulates γ-secretase activity through a direct interaction with Hif-1α, revealing an unconventional function for Hif-1α as an enzyme subunit, which is distinct from its canonical role as a transcription factor. Moreover, hypoxia-induced cell invasion and metastasis are alleviated by either γ-secretase inhibitors or a dominant-negative Notch coactivator, indicating that γ-secretase/Notch signaling plays an essential role in controlling these cellular processes. The present study reveals a mechanism in which γ-secretase can achieve temporal control through conditional interactions with regulatory proteins, such as Hif-1α, under select physiological and pathological conditions.


Assuntos
Secretases da Proteína Precursora do Amiloide/metabolismo , Neoplasias da Mama/metabolismo , Subunidade alfa do Fator 1 Induzível por Hipóxia/fisiologia , Neoplasias Pulmonares/metabolismo , Receptores Notch/metabolismo , Animais , Neoplasias da Mama/patologia , Hipóxia Celular , Linhagem Celular Tumoral , Ativação Enzimática , Feminino , Humanos , Neoplasias Pulmonares/secundário , Camundongos Nus , Transplante de Neoplasias , Ligação Proteica , Transdução de Sinais , Regulação para Cima
18.
Mol Biosyst ; 7(1): 67-73, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21107478

RESUMO

Protein S-prenylation is a lipid modification that regulates membrane-protein and protein-protein interactions in cell signaling. Though sites of protein S-prenylation can be predicted based upon conserved C-terminal CaaX or CC/CXC motifs, biochemical detection of protein S-prenylation in cells is still challenging. Herein, we report an alkynyl-isoprenol chemical reporter (alk-FOH) as an efficient substrate for prenyltransferases in mammalian cells that enables sensitive detection of S-farnesylated and S-geranylgeranylated proteins using bioorthogonal ligation methods. Fluorescent detection alleviates the need to deplete cellular isoprenoids for biochemical analysis of S-prenylated proteins and enables robust characterization of S-prenylated proteins, such as effectors that are injected into host cells by bacterial pathogens. This alkynyl-prenylation reporter provides a sensitive tool for biochemical analysis and rapid profiling of prenylated proteins in cells.


Assuntos
Farneseno Álcool/metabolismo , Prenilação de Proteína/fisiologia , Animais , Linhagem Celular , Dimetilaliltranstransferase/metabolismo , Eletroforese em Gel de Poliacrilamida , Farneseno Álcool/química , Células HeLa , Humanos , Immunoblotting , Imunoprecipitação , Camundongos , Modelos Biológicos
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