Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 371
Filtrar
Mais filtros

Base de dados
Tipo de documento
Intervalo de ano de publicação
1.
Cell ; 156(3): 603-616, 2014 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-24485463

RESUMO

Glioblastomas (GBMs) are the most common and malignant primary brain tumors and are aggressively treated with surgery, chemotherapy, and radiotherapy. Despite this treatment, recurrence is inevitable and survival has improved minimally over the last 50 years. Recent studies have suggested that GBMs exhibit both heterogeneity and instability of differentiation states and varying sensitivities of these states to radiation. Here, we employed an iterative combined theoretical and experimental strategy that takes into account tumor cellular heterogeneity and dynamically acquired radioresistance to predict the effectiveness of different radiation schedules. Using this model, we identified two delivery schedules predicted to significantly improve efficacy by taking advantage of the dynamic instability of radioresistance. These schedules led to superior survival in mice. Our interdisciplinary approach may also be applicable to other human cancer types treated with radiotherapy and, hence, may lay the foundation for significantly increasing the effectiveness of a mainstay of oncologic therapy. PAPERCLIP:


Assuntos
Neoplasias Encefálicas/radioterapia , Glioblastoma/radioterapia , Doses de Radiação , Animais , Neoplasias Encefálicas/patologia , Glioblastoma/patologia , Humanos , Camundongos , Modelos Biológicos
2.
Am J Gastroenterol ; 2024 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-38661148

RESUMO

INTRODUCTION: Assessing the cumulative degree of bowel injury in ileal Crohn's disease (CD) is difficult. We aimed to develop machine learning (ML) methodologies for automated estimation of cumulative ileal injury on computed tomography-enterography (CTE) to help predict future bowel surgery. METHODS: Adults with ileal CD using biologic therapy at a tertiary care center underwent ML analysis of CTE scans. Two fellowship-trained radiologists graded bowel injury severity at granular spatial increments along the ileum (1 cm), called mini-segments. ML segmentation methods were trained on radiologist grading with predicted severity and then spatially mapped to the ileum. Cumulative injury was calculated as the sum (S-CIDSS) and mean of severity grades along the ileum. Multivariate models of future small bowel resection were compared with cumulative ileum injury metrics and traditional bowel measures, adjusting for laboratory values, medications, and prior surgery at the time of CTE. RESULTS: In 229 CTE scans, 8,424 mini-segments underwent analysis. Agreement between ML and radiologists injury grading was strong (κ = 0.80, 95% confidence interval 0.79-0.81) and similar to inter-radiologist agreement (κ = 0.87, 95% confidence interval 0.85-0.88). S-CIDSS (46.6 vs 30.4, P = 0.0007) and mean cumulative injury grade scores (1.80 vs 1.42, P < 0.0001) were greater in CD biologic users that went to future surgery. Models using cumulative spatial metrics (area under the curve = 0.76) outperformed models using conventional bowel measures, laboratory values, and medical history (area under the curve = 0.62) for predicting future surgery in biologic users. DISCUSSION: Automated cumulative ileal injury scores show promise for improving prediction of outcomes in small bowel CD. Beyond replicating expert judgment, spatial enterography analysis can augment the personalization of bowel assessment in CD.

3.
Nat Methods ; 18(6): 669-677, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-34059826

RESUMO

Single-molecule localization microscopy (SMLM) relies on the blinking behavior of a fluorophore, which is the stochastic switching between fluorescent and dark states. Blinking creates multiple localizations belonging to the same fluorophore, confounding quantitative analyses and interpretations. Here we present a method, termed distance distribution correction (DDC), to eliminate blinking-caused repeat localizations without any additional calibrations. The approach relies on obtaining the true pairwise distance distribution of different fluorophores naturally from the imaging sequence by using distances between localizations separated by a time much longer than the average fluorescence survival time. We show that, using the true pairwise distribution, we can define and maximize the likelihood, obtaining a set of localizations void of blinking artifacts. DDC results in drastic improvements in obtaining the closest estimate of the true spatial organization and number of fluorescent emitters in a wide range of applications, enabling accurate reconstruction and quantification of SMLM images.


Assuntos
Algoritmos , Microscopia de Fluorescência/métodos , Imagem Individual de Molécula/métodos , Artefatos , Corantes Fluorescentes/química , Processos Estocásticos
4.
Magn Reson Med ; 91(6): 2568-2578, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38265182

RESUMO

PURPOSE: Analyzing bone marrow in the hematologic cancer myelofibrosis requires endpoint histology in mouse models and bone marrow biopsies in patients. These methods hinder the ability to monitor therapy over time. Preclinical studies typically begin treatment before mice develop myelofibrosis, unlike patients who begin therapy only after onset of disease. Using clinically relevant, quantitative MRI metrics allowed us to evaluate treatment in mice with established myelofibrosis. METHODS: We used chemical shift-encoded fat imaging, DWI, and magnetization transfer sequences to quantify bone marrow fat, cellularity, and macromolecular components in a mouse model of myelofibrosis. We monitored spleen volume, the established imaging marker for treatment, with anatomic MRI. After confirming bone marrow disease by MRI, we randomized mice to treatment with an approved drug (ruxolitinib or fedratinib) or an investigational agent, navitoclax, for 33 days. We measured the effects of therapy over time with bone marrow and spleen MRI. RESULTS: All treatments produced heterogeneous responses with improvements in bone marrow evident in subsets of individual mice in all treatment groups. Reductions in spleen volume commonly occurred without corresponding improvement in bone marrow. MRI revealed patterns associated with effective and ineffective responses to treatment in bone marrow and identified regional variations in efficacy within a bone. CONCLUSIONS: Quantitative MRI revealed modest, heterogeneous improvements in bone marrow disease when treating mice with established myelofibrosis. These results emphasize the value of bone marrow MRI to assess treatment in preclinical models and the potential to advance clinical trials for patients.


Assuntos
Medula Óssea , Mielofibrose Primária , Animais , Camundongos , Medula Óssea/diagnóstico por imagem , Medula Óssea/patologia , Imageamento por Ressonância Magnética , Mielofibrose Primária/diagnóstico por imagem , Mielofibrose Primária/tratamento farmacológico , Mielofibrose Primária/patologia , Baço/diagnóstico por imagem
5.
Rural Remote Health ; 24(2): 8725, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38909989

RESUMO

INTRODUCTION: The Northern Ontario School of Medicine University seeks to address rural physician shortages in Northern Ontario. One key strategy the school employs is the use of experiential learning placements embedded throughout its undergraduate curriculum. In second year, students embark on two 4-week placements in rural and remote communities. This study sought to explore the factors that contribute to a positive learning experience from the preceptor's perspective. METHODS: Semi-structured interviews were conducted with five community preceptors who have participated in these placements. Using the information from these interviews a survey was created and sent to another 15 preceptors. Data were analyzed using qualitative methods and frequencies. RESULTS: Three key themes were identified from both the interviews and survey data: the role of early rural and remote placements; the risks of these placements; and the need for a reciprocal relationship between institutions, preceptors, and students to create a positive learning environment. CONCLUSION: Preceptors value the opportunity to teach students, but the aims of these placements are not clear and preceptors and local hospitals need more workforce resources to make these experiences positive.


Assuntos
Preceptoria , Serviços de Saúde Rural , Humanos , Preceptoria/organização & administração , Serviços de Saúde Rural/organização & administração , Ontário , Entrevistas como Assunto , Educação de Graduação em Medicina/organização & administração , Estudantes de Medicina/psicologia , Estudantes de Medicina/estatística & dados numéricos , Área Carente de Assistência Médica
6.
Med Teach ; 45(4): 404-411, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36288735

RESUMO

BACKGROUND: In an arts integrated interdisciplinary study set to investigate ways to improve social accountability (SA) in medical education, our research team has established a renewed understanding of compassion in the current SA movement. AIM: This paper explores the co-evolution of compassion and SA. METHODS: The study used an arts integrated approach to investigate people's perceptions of SA in four medical schools across Australia, Canada, and the USA. Each school engaged approximately 25 participants who partook in workshops and in-depth interviews. RESULTS: We began with a study of SA and the topic of compassion emerged out of our qualitative data and biweekly meetings within the research team. Content analysis of the data and pedagogical discussion brought us to realize the importance of compassion in the practice of SA. CONCLUSIONS: The cultivation of compassion needs to play a significant role in a socially accountable medical educational system. Medical schools as educational institutions may operate themselves with compassion as a driving force in engaging partnership with students and communities. Social accountability without compassion is not SA; compassion humanizes institutional policy by engaging sympathy and care.


Assuntos
Educação Médica , Empatia , Humanos , Responsabilidade Social , Austrália , Canadá
7.
Eur J Immunol ; 51(10): 2441-2451, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34287839

RESUMO

Inhibition of the BCL6 BTB domain results in killing Diffuse Large B-cell Lymphoma (DLBL) cells, reducing the T-cell dependent germinal center (GC) reaction in mice, and reversing GC hyperplasia in nonhuman primates. The available BCL6 BTB-specific inhibitors are poorly water soluble, thus, limiting their absorption in vivo and our understanding of therapeutic strategy targeting GC. We synthesized a prodrug (AP-4-287) from a potent BCL6 BTB inhibitor (FX1) with improved aqueous solubility and pharmacokinetics (PK) in mice. We also evaluated its in vivo biological activity on humoral immune responses using the sheep red blood cells (SRBC)-vaccination mouse model. AP-4-287 had a significant higher aqueous solubility and was readily converted to FX1 in vivo after intraperitoneally (i.p.) administration, but a shorter half-life in vivo. Importantly, AP-4-287 treatment led to a reversible effect on (1) the reduction in the frequency of splenic Ki67+ CD4+ T cells, Tfh cells, and GC B cells; (2) lower GC formation following vaccination; and (3) a decrease in the titers of antigen-specific IgG and IgM antibodies. Our study advances the preclinical development of drug targeting BCL6 BTB domain for the treatment of diseases that are associated with abnormal BCL6 elevation.


Assuntos
Ativação Linfocitária/efeitos dos fármacos , Ativação Linfocitária/imunologia , Domínios e Motivos de Interação entre Proteínas/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-bcl-6/antagonistas & inibidores , Linfócitos T/efeitos dos fármacos , Linfócitos T/imunologia , Linfócitos T/metabolismo , Animais , Formação de Anticorpos/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Diferenciação Celular/imunologia , Técnicas de Química Sintética , Centro Germinativo/efeitos dos fármacos , Centro Germinativo/imunologia , Centro Germinativo/metabolismo , Imunidade Humoral/efeitos dos fármacos , Imunomodulação/efeitos dos fármacos , Indóis/administração & dosagem , Indóis/síntese química , Indóis/farmacocinética , Camundongos , Pró-Fármacos/administração & dosagem , Pró-Fármacos/síntese química , Pró-Fármacos/farmacocinética , Proteínas Proto-Oncogênicas c-bcl-6/química , Proteínas Proto-Oncogênicas c-bcl-6/metabolismo , Subpopulações de Linfócitos T/efeitos dos fármacos , Subpopulações de Linfócitos T/imunologia , Subpopulações de Linfócitos T/metabolismo , Tiazolidinedionas/administração & dosagem , Tiazolidinedionas/síntese química , Tiazolidinedionas/farmacocinética
8.
Radiology ; 302(1): 218-225, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34665030

RESUMO

Background Aortic diameter measurements in patients with a thoracic aortic aneurysm (TAA) show wide variation. There is no technique to quantify aortic growth in a three-dimensional (3D) manner. Purpose To validate a CT-based technique for quantification of 3D growth based on deformable registration in patients with TAA. Materials and Methods Patients with ascending and descending TAA with two or more CT angiography studies between 2006 and 2020 were retrospectively identified. The 3D aortic growth was quantified using vascular deformation mapping (VDM), a technique that uses deformable registration to warp a mesh constructed from baseline aortic anatomy. Growth assessments between VDM and clinical CT diameter measurements were compared. Aortic growth was quantified as the ratio of change in surface area at each mesh element (area ratio). Manual segmentations were performed by independent raters to assess interrater reproducibility. Registration error was assessed using manually placed landmarks. Agreement between VDM and clinical diameter measurements was assessed using Pearson correlation and Cohen κ coefficients. Results A total of 38 patients (68 surveillance intervals) were evaluated (mean age, 69 years ± 9 [standard deviation]; 21 women), with TAA involving the ascending aorta (n = 26), descending aorta (n = 10), or both (n = 2). VDM was technically successful in 35 of 38 (92%) patients and 58 of 68 intervals (85%). Median registration error was 0.77 mm (interquartile range, 0.54-1.10 mm). Interrater agreement was high for aortic segmentation (Dice similarity coefficient = 0.97 ± 0.02) and VDM-derived area ratio (bias = 0.0, limits of agreement: -0.03 to 0.03). There was strong agreement (r = 0.85, P < .001) between peak area ratio values and diameter change. VDM detected growth in 14 of 58 (24%) intervals. VDM revealed growth outside the maximally dilated segment in six of 14 (36%) growth intervals, none of which were detected with diameter measurements. Conclusion Vascular deformation mapping provided reliable and comprehensive quantitative assessment of three-dimensional aortic growth and growth patterns in patients with thoracic aortic aneurysms undergoing CT surveillance. Published under a CC BY 4.0 license Online supplemental material is available for this article. See also the editorial by Wieben in this issue.


Assuntos
Aneurisma da Aorta Torácica/diagnóstico por imagem , Aneurisma da Aorta Torácica/patologia , Angiografia por Tomografia Computadorizada/métodos , Imageamento Tridimensional/métodos , Idoso , Aorta Torácica/diagnóstico por imagem , Aorta Torácica/patologia , Feminino , Humanos , Masculino , Reprodutibilidade dos Testes , Estudos Retrospectivos
9.
J Viral Hepat ; 29(2): 147-155, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34773341

RESUMO

Hepatitis C is a leading cause of liver disease and transplantation and is a significant burden on public health worldwide. This study aimed to apply the Electronic Nose (E-Nose) and quadrupole Mass Spectrometry (MS/MS) technologies for screening blood samples from hepatitis C patients and healthy controls. We analysed volatile organic compounds (VOCs) in the headspace over blood samples to identify those VOCs characteristic for diagnosing hepatitis C patients. The study comprised 150 acute hepatitis C patients with age range: 24-59 years, and mean age ±SD: 41.5 ± 12.8 years and 150 age-matched healthy controls (age range: 24-51 and mean age: 40.11 ± 4.89 years) from the Hospital of the Medical Research Institute, Alexandria University, Alexandria, Egypt. Collected blood samples were analysed qualitatively and quantitatively using the E-Nose and MS/MS techniques, respectively. Principal component analysis of the E-Nose 10-sensor responses accurately classified blood samples from hepatitis C patients and healthy controls. The first two principal components explained over 98.35% of the variance in signals with no false-positive (healthy controls) or false-negative (hepatitis C patients) results. MS/MS showed two fragmentation ions at m/z of 104 and 151 Da with the positive electrospray ionization mode (ESI+) in blood samples for hepatitis C patients, but not for healthy controls or background water samples. We identified the two specific fragmentation ions at m/z 104 and m/z 151 Da as malonic acid (MF: C3 H4 O4 ; MW: 104.06 g/mol) and monosaccharide pentose (MF: C5 H10 O5 ; MW: 150.13 g/mol) in VOCs of the headspace over blood samples for hepatitis C patients. This provides a rationale for developing diagnostic tests for hepatitis C virus based on altered trace VOCs concentrations using the relatively inexpensive, easy-to-use, portable and non-invasive E-Nose technology.


Assuntos
Hepatite C , Hepatite Viral Humana , Compostos Orgânicos Voláteis , Adulto , Nariz Eletrônico , Hepatite C/diagnóstico , Humanos , Pessoa de Meia-Idade , Espectrometria de Massas em Tandem , Adulto Jovem
10.
Int J Audiol ; 61(8): 621-631, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-34622731

RESUMO

Objective: This exploratory Phase 2 clinical trial is the first determining safety and efficacy of oral D-methionine (D-met) in reducing cisplatin-induced ototoxicity.Design: Randomised parallel double-blind placebo-controlled exploratory Phase 2 study.Study samples: Fifty adult cancer patients received oral D-met or placebo before each cisplatin dose. Physical examination, blood collection and audiometry occurred at baseline and subsequent visits plus post-treatment audiometry. After attrition, final analysis included 27 patients.Results: Significant treatment group by ear and time (baseline vs. post-treatment) interactions occurred at 10 kHz and 11.2 kHz. Placebo and D-met groups differed in threshold shift for left ear at 11.2 kHz (mean difference = 22.97 dB [9.59, 36.35]). Averaging across ears, placebo group showed significant threshold shifts from baseline to post-treatment at 10 kHz (mean shift= -13.65 dB [-21.32,-5.98]), 11.2 kHz (-16.15 dB [-25.19,-7.12]), and 12.5 kHz (-11.46 dB [-19.18,-3.74]) but not 8 kHz (-8.65 dB [-17.86, 0.55]). The D-met group showed no significant threshold shifts (8 kHz: -1.25 dB [-7.75, 5.25]; 10 kHz:-3.93 dB [-8.89, 1.03]; 11.2 kHz:-4.82 dB [-11.21, 1.57]; 12.5 kHz:-3.68 dB [-11.57, 4.21]). Side effects did not significantly differ between groups.Conclusion: Oral D-met reduces cisplatin-induced ototoxicity in humans.


Assuntos
Perda Auditiva , Metionina , Adulto , Limiar Auditivo , Cisplatino/toxicidade , Perda Auditiva/induzido quimicamente , Perda Auditiva/diagnóstico , Perda Auditiva/prevenção & controle , Humanos , Índia , Metionina/uso terapêutico , Ototoxicidade/prevenção & controle
11.
Int J Health Plann Manage ; 37 Suppl 1: 59-78, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-35986520

RESUMO

Health care and academic institutions are increasingly committing to social accountability, a strategic shift that requires priorities, activities, and evaluations to be co-determined with all relevant partners. Consequently, governments, accreditors, funders, and communities are calling for these institutions to communicate their progress towards social accountability. The purpose of this study was to develop a conceptual framework around a socially accountable learning health system. This article presents an integrated analysis of two studies: (i) a narrative review of 11 prominent social accountability and health services conceptual frameworks and (ii) a reflexive thematic analysis of 18 key informant interviews. Using a systematic conceptual framework development and integrated theory of change/realist evaluation methodologies, we describe a synthesis of these findings to develop a conceptual framework for describing and evaluating socially accountable health professional education. The resulting framework describes assessment phases of social accountability, transitions between phases, learning cycles, and the actors and systems that collectively mobilise social accountability at multiple levels in health and education systems. The framework can be used to evaluate interventions or characterise progress towards social accountability in different settings, as illustrated in the example at the end of the paper. The framework emphasises the significance of designing, mobilising, and evaluating social accountability as part of a contextualised learning health system.


Assuntos
Educação Médica , Sistema de Aprendizagem em Saúde , Humanos , Aprendizagem , Responsabilidade Social , População Rural
12.
Clin Infect Dis ; 72(3): 495-498, 2021 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-33527127

RESUMO

Accurate characterization of the human immunodeficiency virus (HIV) reservoir is imperative to develop an effective cure. HIV was measured in antiretroviral therapy-suppressed individuals using the intact proviral DNA assay (IPDA), along with assays for total or integrated HIV DNA, and inducible HIV RNA or p24. Intact provirus correlated with total and integrated HIV.


Assuntos
Infecções por HIV , HIV-1 , Linfócitos T CD4-Positivos , DNA Viral/genética , Infecções por HIV/tratamento farmacológico , HIV-1/genética , Humanos , Provírus/genética , Latência Viral
13.
Bioconjug Chem ; 32(10): 2195-2204, 2021 10 20.
Artigo em Inglês | MEDLINE | ID: mdl-34591471

RESUMO

Nanoscale metal-organic frameworks (nMOFs) are a unique type of hybrid materials, which are broadly applicable as cargo delivery systems. However, the relatively low material stability and insufficient cancer cell interacting capacity have limited nMOFs' applications in cancer theranostics. Herein, a zirconium-based nMOF UiO-66-N3 was synthesized, and its surface was covalently functionalized with alkyne-containing polyethylene glycol (PEG) via the azide-alkyne click chemistry. After that, F3 peptide was attached for targeting of cancer cells (the material was denoted as UiO-66-PEG-F3). Doxorubicin (DOX) served as a therapeutic drug and a fluorescent label in this study, and it was transported into UiO-66-PEG conjugates with sufficient drug loading efficiency. pH-responsive release of DOX from UiO-66 conjugates was witnessed. The structural integrity of UiO-66-N3 was maintained post the surface modification process. Flow cytometry and confocal fluorescence microscopy revealed that DOX/UiO-66-PEG-F3 had stronger accumulation in MDA-MB-231 cells (nucleolin+) compared with DOX/UiO-66-PEG. In order to track the pharmacokinetic behavior (organ distribution profile) in vivo, the positron-emitting zirconium-89 (89Zr) was incorporated into UiO-66-N3. Similar PEGylation and F3 peptide conjugation resulted in the formation of 89Zr-UiO-66-PEG-F3. Serial positron emission tomography (PET) imaging demonstrated that the preferential accumulation of 89Zr-UiO-66-PEG-F3 in MDA-MB-231 tumors, and their liver clearance was faster than PEGylated UiO-66 using noncovalent methods. Thus, the PEGylated nMOFs using covalent strategies may find broad application in future cancer theranostics.


Assuntos
Portadores de Fármacos , Estruturas Metalorgânicas
14.
Mol Pharm ; 18(4): 1690-1698, 2021 04 05.
Artigo em Inglês | MEDLINE | ID: mdl-33734721

RESUMO

The urokinase plasminogen activator (uPA) and its cofactors are important regulators of tumor initiation and progression (including metastasis), and its overexpression is associated with unfavorable situations in cancer patients. We have previously used positron emission tomography (PET) imaging with a radiolabeled monoclonal antibody against the uPA (named ATN-291) to detect the uPA signaling activity in various cancer types; however, good tumor contrast can only be observed 24 h postinjection. To shorten the antibody circulation time and decrease interactions of ATN-291 with the mononuclear phagocyte system (MPS), our goal in this study is to develop an engineered antibody fragment (F(ab')2) from the parent antibody. By pepsin digestion and chromatography purification, ATN-291 F(ab')2 was obtained and characterized. Subsequently, it was conjugated with NOTA-Bn-NCS or fluorescein isothiocyanate (FITC) for PET imaging and fluorescence-mediated cellular analysis (i.e., flow cytometry or fluorescence microscopy). We confirmed that ATN-291 F(ab')2 still maintained a good targeting efficacy for the uPA in MDA-MB-231 cells (uPA+) and it had a faster blood clearance speed compared with ATN-291, while its interaction with MPS has been significantly decreased. In rodent tumor xenografts, radiolabeled ATN-291 F(ab')2 had a selective and persistent uptake in MDA-MB-231 tumors, with an early tumor-to-blood ratio of 1.3 ± 0.8 (n = 4) at 2 h postinjection from PET imaging. During our observation, radiolabeled ATN-291 F(ab')2 was excreted from both renal and hepatobiliary pathways. Radiolabeled ATN-291 F(ab')2 was also used for detecting uPA fluctuation during the tumor treatment in test animals. We concluded that radiolabeled ATN-291 F(ab')2 could be used as fast as PET cancer diagnostics with versatile applicability.


Assuntos
Anticorpos Monoclonais/administração & dosagem , Fragmentos Fab das Imunoglobulinas/administração & dosagem , Proteínas de Membrana/antagonistas & inibidores , Tomografia por Emissão de Pósitrons/métodos , Neoplasias de Mama Triplo Negativas/diagnóstico , Animais , Anticorpos Monoclonais/química , Anticorpos Monoclonais/genética , Feminino , Fluoresceína-5-Isotiocianato/química , Humanos , Fragmentos Fab das Imunoglobulinas/química , Fragmentos Fab das Imunoglobulinas/genética , Proteínas de Membrana/metabolismo , Camundongos , Engenharia de Proteínas , Neoplasias de Mama Triplo Negativas/patologia , Ensaios Antitumorais Modelo de Xenoenxerto
15.
J Immunol ; 203(3): 705-717, 2019 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-31253727

RESUMO

We previously reported that pegylated IFN-α2a (Peg-IFN-α2a) added to antiretroviral therapy (ART)-suppressed, HIV-infected subjects resulted in plasma HIV control and integrated HIV DNA decrease. We now evaluated whether innate NK cell activity or PBMC transcriptional profiles were associated with decreases in HIV measures. Human peripheral blood was analyzed prior to Peg-IFN-α2a administration (ART, baseline), after 5 wk of ART+Peg-IFN-α2a, and after 12 wk of Peg-IFN-α2a monotherapy (primary endpoint). After 5 wk of ART+Peg-IFN-α2a, immune subset frequencies were preserved, and induction of IFN-stimulated genes was noted in all subjects except for a subset in which the lack of IFN-stimulated gene induction was associated with increased expression of microRNAs. Viral control during Peg-IFN-α2a monotherapy was associated with 1) higher levels of NK cell activity and IFN-γ-induced protein 10 (IP-10) on ART (preimmunotherapy) and 2) downmodulation of NK cell KIR2DL1 and KIR2DL2/DL3 expression, transcriptional enrichment of expression of genes associated with NK cells in HIV controller subjects, and higher ex vivo IFN-α-induced NK cytotoxicity after 5 wk of ART+Peg-IFN-α2a. Integrated HIV DNA decline after immunotherapy was also associated with gene expression patterns indicative of cell-mediated activation and NK cytotoxicity. Overall, an increase in innate activity and NK cell cytotoxicity were identified as correlates of Peg-IFN-α2a-mediated HIV control.


Assuntos
Terapia Antirretroviral de Alta Atividade/métodos , Infecções por HIV/tratamento farmacológico , HIV-1/efeitos dos fármacos , Interferon-alfa/uso terapêutico , Células Matadoras Naturais/imunologia , Polietilenoglicóis/uso terapêutico , Células Cultivadas , Quimiocina CXCL10/metabolismo , Infecções por HIV/imunologia , HIV-1/imunologia , Humanos , MicroRNAs/biossíntese , MicroRNAs/genética , Receptores KIR2DL1/biossíntese , Receptores KIR2DL2/biossíntese , Proteínas Recombinantes/uso terapêutico
16.
Breast Cancer Res ; 22(1): 60, 2020 06 05.
Artigo em Inglês | MEDLINE | ID: mdl-32503622

RESUMO

BACKGROUND: Mitochondrial dynamics underlies malignant transformation, cancer progression, and response to treatment. Current research presents conflicting evidence for functions of mitochondrial fission and fusion in tumor progression. Here, we investigated how mitochondrial fission and fusion states regulate underlying processes of cancer progression and metastasis in triple-negative breast cancer (TNBC). METHODS: We enforced mitochondrial fission and fusion states through chemical or genetic approaches and measured migration and invasion of TNBC cells in 2D and 3D in vitro models. We also utilized kinase translocation reporters (KTRs) to identify single cell effects of mitochondrial state on signaling cascades, PI3K/Akt/mTOR and Ras/Raf/MEK/ERK, commonly activated in TNBC. Furthermore, we determined effects of fission and fusion states on metastasis, bone destruction, and signaling in mouse models of breast cancer. RESULTS: Enforcing mitochondrial fission through chemical or genetic approaches inhibited migration, invasion, and metastasis in TNBC. Breast cancer cells with predominantly fissioned mitochondria exhibited reduced activation of Akt and ERK both in vitro and in mouse models of breast cancer. Treatment with leflunomide, a potent activator of mitochondrial fusion proteins, overcame inhibitory effects of fission on migration, signaling, and metastasis. Mining existing datasets for breast cancer revealed that increased expression of genes associated with mitochondrial fission correlated with improved survival in human breast cancer. CONCLUSIONS: In TNBC, mitochondrial fission inhibits cellular processes and signaling pathways associated with cancer progression and metastasis. These data suggest that therapies driving mitochondrial fission may benefit patients with breast cancer.


Assuntos
Transformação Celular Neoplásica/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Dinâmica Mitocondrial/fisiologia , Neoplasias de Mama Triplo Negativas/metabolismo , Neoplasias de Mama Triplo Negativas/patologia , Animais , Neoplasias Ósseas/tratamento farmacológico , Neoplasias Ósseas/metabolismo , Neoplasias Ósseas/secundário , Carboxiliases/genética , Carboxiliases/metabolismo , Transformação Celular Neoplásica/metabolismo , Transformação Celular Neoplásica/patologia , Feminino , Humanos , Imunossupressores/farmacologia , Leflunomida/farmacologia , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Mitocôndrias/metabolismo , Mitocôndrias/patologia , Invasividade Neoplásica , Fosfatidilinositol 3-Quinases/genética , Fosfatidilinositol 3-Quinases/metabolismo , Prognóstico , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , Serina-Treonina Quinases TOR/genética , Serina-Treonina Quinases TOR/metabolismo , Neoplasias de Mama Triplo Negativas/tratamento farmacológico , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de Xenoenxerto
17.
Nat Methods ; 14(4): 427-434, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28288122

RESUMO

Compartmentalized biochemical activities are essential to all cellular processes, but there is no generalizable method to visualize dynamic protein activities in living cells at a resolution commensurate with cellular compartmentalization. Here, we introduce a new class of fluorescent biosensors that detect biochemical activities in living cells at a resolution up to threefold better than the diffraction limit. These 'FLINC' biosensors use binding-induced changes in protein fluorescence dynamics to translate kinase activities or protein-protein interactions into changes in fluorescence fluctuations, which are quantifiable through stochastic optical fluctuation imaging. A protein kinase A (PKA) biosensor allowed us to resolve minute PKA activity microdomains on the plasma membranes of living cells and to uncover the role of clustered anchoring proteins in organizing these activity microdomains. Together, these findings suggest that biochemical activities of the cell are spatially organized into an activity architecture whose structural and functional characteristics can be revealed by these new biosensors.


Assuntos
Técnicas Biossensoriais/métodos , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Membrana Celular/metabolismo , Proteínas Quinases Dependentes de AMP Cíclico/análise , Escherichia coli/genética , Transferência Ressonante de Energia de Fluorescência/métodos , Corantes Fluorescentes , Proteínas de Fluorescência Verde/metabolismo , Células HeLa , Humanos , Microscopia/instrumentação , Microscopia/métodos , Imagem Molecular/métodos , Mutagênese Sítio-Dirigida , Mapeamento de Interação de Proteínas/métodos , Processos Estocásticos
18.
Am J Respir Crit Care Med ; 200(5): 575-581, 2019 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-30794432

RESUMO

Rationale: Evidence suggests damage to small airways is a key pathologic lesion in chronic obstructive pulmonary disease (COPD). Computed tomography densitometry has been demonstrated to identify emphysema, but no such studies have been performed linking an imaging metric to small airway abnormality.Objectives: To correlate ex vivo parametric response mapping (PRM) analysis to in vivo lung tissue measurements of patients with severe COPD treated by lung transplantation and control subjects.Methods: Resected lungs were inflated, frozen, and systematically sampled, generating 33 COPD (n = 11 subjects) and 22 control tissue samples (n = 3 subjects) for micro-computed tomography analysis of terminal bronchioles (TBs; last generation of conducting airways) and emphysema.Measurements and Main Results: PRM analysis was conducted to differentiate functional small airways disease (PRMfSAD) from emphysema (PRMEmph). In COPD lungs, TB numbers were reduced (P = 0.01); surviving TBs had increased wall area percentage (P < 0.001), decreased circularity (P < 0.001), reduced cross-sectional luminal area (P < 0.001), and greater airway obstruction (P = 0.008). COPD lungs had increased airspace size (P < 0.001) and decreased alveolar surface area (P < 0.001). Regression analyses demonstrated unique correlations between PRMfSAD and TBs, with decreased circularity (P < 0.001), decreased luminal area (P < 0.001), and complete obstruction (P = 0.008). PRMEmph correlated with increased airspace size (P < 0.001), decreased alveolar surface area (P = 0.003), and fewer alveolar attachments per TB (P = 0.01).Conclusions: PRMfSAD identifies areas of lung tissue with TB loss, luminal narrowing, and obstruction. This is the first confirmation that an imaging biomarker can identify terminal bronchial pathology in established COPD and provides a noninvasive imaging methodology to identify small airway damage in COPD.


Assuntos
Obstrução das Vias Respiratórias/diagnóstico por imagem , Biomarcadores , Doença Pulmonar Obstrutiva Crônica/fisiopatologia , Microtomografia por Raio-X/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
19.
Carcinogenesis ; 40(2): 225-233, 2019 04 29.
Artigo em Inglês | MEDLINE | ID: mdl-30364933

RESUMO

Identification of factors associated with human papillomavirus (HPV) cervical histopathology or recurrence/relapse following loop electrosurgical excision procedure (LEEP) would allow for better management of the disease. We investigated whether gene signatures could (i) associate with HPV cervical histopathology and (ii) identify women with post-LEEP disease recurrence/relapse. Gene array analysis was performed on paraffin-embedded cervical tissue-isolated RNA from two cross-sectional cohorts of antiretroviral therapy (ART)-suppressed HIV+HPV+ coinfected women: (i) 55 women in South Africa recruited into three groups: high risk (HR) (-) (n = 16) and HR (+) (n = 15) HPV without cervical histopathology and HR (+) HPV with cervical intraepithelial neoplasia (CIN) grade 1/2/3 (n = 24), (ii) 28 women in Botswana with CIN2/3 treated with LEEP 12-month prior to recruitment and presenting with (n = 13) and without (n = 15) lesion recurrence/relapse (tissue was analyzed at first LEEP). Three distinct gene expression signatures identified were able to segregate: (i) HR+ HPV and CIN1/2/3, (ii) HR HPV-free and cervical histopathology-free and (iii) HR+ HPV and cervical histopathology-free. Immune activation and neoplasia-associated genes (n = 272 genes; e.g. IL-1A, IL-8, TCAM1, POU4F1, MCM2, SMC1B, CXCL6, MMP12) were a feature of cancer precursor dysplasia within HR HPV infection. No difference in LEEP tissue gene expression was detected between women with or without recurrence/relapse. In conclusion, distinctive gene signatures were associated with presence of cervical histopathology in tissues from ART-suppressed HIV+/HPV+ coinfected women. Lack of detection of LEEP tissue gene signature able to segregate subsequent post-LEEP disease recurrence/relapse indicates additional factors independent of local gene expression as determinants of recurrence/relapse.


Assuntos
Colo do Útero/patologia , Expressão Gênica/genética , Infecções por Papillomavirus/genética , Infecções por Papillomavirus/patologia , Neoplasias do Colo do Útero/genética , Neoplasias do Colo do Útero/patologia , Adulto , Antirretrovirais/farmacologia , Colo do Útero/efeitos dos fármacos , Colo do Útero/virologia , Estudos Transversais , Feminino , Expressão Gênica/efeitos dos fármacos , Perfilação da Expressão Gênica/métodos , Infecções por HIV/tratamento farmacológico , Infecções por HIV/patologia , Infecções por HIV/virologia , Humanos , Recidiva Local de Neoplasia/etiologia , Recidiva Local de Neoplasia/genética , Recidiva Local de Neoplasia/patologia , Recidiva Local de Neoplasia/virologia , Papillomaviridae/efeitos dos fármacos , Infecções por Papillomavirus/tratamento farmacológico , Infecções por Papillomavirus/virologia , Neoplasias do Colo do Útero/tratamento farmacológico , Neoplasias do Colo do Útero/virologia , Displasia do Colo do Útero/tratamento farmacológico , Displasia do Colo do Útero/genética , Displasia do Colo do Útero/patologia , Displasia do Colo do Útero/virologia
20.
Mem Cognit ; 47(5): 877-892, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-30725375

RESUMO

The reminding effect (Tullis, Benjamin, & Ross, Journal of Experimental Psychology: General, 143[4], 1526-1540, 2014) describes the increase in recall of a studied word when a related word is presented later in the study list. However, because the process of reminding is thought to occur during study, measures of test performance are indirect indicators of the process of reminding and are subject to influences that arise during testing. The present research seeks evidence of reminding during encoding. In two experiments, self-paced study times were used to index the online process of reminding. In Experiment 1, pairs of repeated words, related words, and unrelated words were included in a study list. Study times were shorter for words related to prior words in the list, but only when the lag between those two words was short. Relatedness affected study time by inspiring a reduction in the threshold for termination of study for related words under massed conditions. Experiment 2 replicated the reduction in study time for related words and further showed that the study time allotted to an associate of an earlier item predicted better memory for that earlier word on a cued-recall test. In this experiment, an advantage in memory was observed for related words, and self-paced study time of one word during encoding was predictive of later memory for a related word. These results suggest a link between the action of reminding at study, as indexed by changes in the distribution of study time, and later benefits to remembering, as revealed by the reminding effect.


Assuntos
Associação , Sinais (Psicologia) , Rememoração Mental/fisiologia , Reconhecimento Psicológico/fisiologia , Adulto , Humanos , Fatores de Tempo , Adulto Jovem
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA