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INTRODUCTION: In vivo positron emission tomography (PET) and magnetic resonance imaging (MRI) support non-invasive assessment of the spatiotemporal expression of proteins of interest and functional/structural changes. Our work promotes the use of a volumetric analysis on multimodal imaging datasets to assess the spatio-temporal dynamics and interaction of two imaging biomarkers, with a special focus on two neuroinflammation-related biomarkers, the translocator protein (TSPO) and matrix metalloproteinases (MMPs), in the acute and chronic post-ischemic phase. AIM: To improve our understating of the neuroinflammatory reaction and tissue heterogeneity during the post ischemic phase, we aimed (i) to assess the spatio-temporal distribution of two radiotracers, [18F]DPA-714 (TSPO) and [18F]BR-351 (MMPs), (ii) to investigate their spatial interaction, including exclusive and overlapping areas, and (iii) their relationship with the T2w-MRI ischemic lesion in a transient middle cerebral artery occlusion (tMCAo) mouse model using an atlas-based volumetric analysis. METHODS: As described by Zinnhardt et al. (2015), a total of N = 30 C57BL/6 mice underwent [18F]DPA-714 and [18F]BR-351 PET-CT and subsequent MR imaging 24-48 h (n = 8), 7 ± 1 days (n = 8), 14 ± 1 days (n = 7), and 21 ± 1 days (n = 7) after 30 min transient middle cerebral artery occlusion (tMCAo). To further investigate the spatio-temporal distribution of [18F]DPA-714 and [18F]BR-351, an atlas-based ipsilesional volume of interest (VOI) was applied to co-registered PET-CT images and thresholded by the mean uptake + 2.5*standard deviation of a contralateral striatal control VOI. Mean lesion-to-contralateral ratios (L/C), volume extension (V in voxel), percentages of overlap and exclusive tracer uptake areas were determined. Both tracer volumes were also compared to the lesion extent depicted by T2w-MR imaging. RESULTS: Both imaging biomarkers showed a constant small percentage of overlap across all time points (14.0 ± 14.2%). [18F]DPA-714 reached its maximum extent and uptake at day 14 post ischemia (V = 12,143 ± 6262 voxels, L/C = 2.32 ± 0.48). The majority of [18F]DPA-714 volume (82.4 ± 16.1%) was exclusive for [18F]DPA-714 and showed limited overlap with [18F]BR-351 and T2w-MRI lesion volumes. On the other hand, [18F]BR-351 reached its maximum extent already 24-48 h after tMCAo (V = 7279 ± 4518 voxels) and significantly decreased at day 14 (V = 1706 ± 1202 voxels). Focal spots of residual activity were still observed at day 21 post ischemia (L/C = 2.10 ± 0.37). The majority of [18F]BR-351 volume was exclusive for [18F]BR-351 (81.50 ± 25.07%) at 24-48 h and showed 64.84 ± 28.29% of overlap with [18F]DPA-714 from day 14 post ischemia while only 9.28 ± 13.45% of the [18F]BR-351 volume were overlapping the T2w-MRI lesion. The percentage of exclusive area of [18F]DPA-714 and [18F]BR-351 uptakes regarding T2w-MR lesion increased over time, suggesting that TSPO and MMPs are mostly localized in the periinfarct region at latter time points. CONCLUSION: This study promotes the use of an unbiased volumetric analyses of multi-modal imaging data sets to improve the characterization of pathological tissue heterogeneity. This approach improves our understanding of (i) the dynamics of disease-related multi-modal imaging biomarkers, (ii) their spatiotemporal interactions and (iii) the post-ischemic tissue heterogeneity. Our results indicate acute MMPs activation after tMCAo preceding TSPO-dependent (micro-)gliosis. The spatial distribution of MMPs and gliosis is regionally independent with only minor (< 20%) overlapping areas in periinfarct regions.
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Isquemia Encefálica/diagnóstico por imagem , Infarto da Artéria Cerebral Média/diagnóstico por imagem , Imageamento por Ressonância Magnética , Neuroimagem , Tomografia por Emissão de Pósitrons , Animais , Isquemia Encefálica/etiologia , Isquemia Encefálica/metabolismo , Isquemia Encefálica/patologia , Modelos Animais de Doenças , Infarto da Artéria Cerebral Média/complicações , Masculino , Metaloproteinases da Matriz/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Imagem Multimodal , Receptores de GABA/metabolismoRESUMO
OBJECTIVES: To study celiac-specific antibody status over 3 years in patients with type 1 diabetes and biopsy-proven celiac disease (T1D + CD). Furthermore, to determine clinical differences after diagnosis between patients reaching constant antibody-negativity (Ab-neg) and staying antibody-positive (Ab-pos). METHODS: A total of 608 pediatric T1D + CD patients from the multicenter DPV registry were studied longitudinally regarding their CD specific antibody-status. Differences between Ab-neg (n = 218) and Ab-pos (n = 158) patients 3 years after biopsy were assessed and compared with 26 833 T1D patients without CD by linear and logistic regression adjusted for age, gender, diabetes duration and migration background. RESULTS: Thirty-six percent of T1D + CD patients reached and sustained antibody-negativity 3 years after CD diagnosis. The median time until patients returned to Ab-neg was 0.86 (0.51;1.16) years. Three years after diagnosis, HbA1c was lowest in Ab-neg and highest in Ab-pos patients compared to T1D-only patients (adjusted mean (95%CI): 7.72 (7.51-7.92) % vs 8.44 (8.20-8.68) % vs 8.19 (8.17-8.21) %, adjusted P < 0.001, respectively). Total cholesterol, LDL-cholesterol and frequency of dyslipidemia were significantly lower in Ab-neg compared to T1D-only patients (167 (161-173) mg/dl vs 179 (178-179) mg/dl, P < .001; 90 (84-96) mg/dl vs 99 (98-99) mg/dl, P = .005; 15.7 (10.5-22.9) % vs 25.9 (25.2-26.6) %, P = .017). In longitudinal analyses over 6 years after diagnosis, a constantly higher HbA1c (P < .001) and a lower height-SDS (P = .044) was observed in Ab-pos compared to Ab-neg patients. CONCLUSION: Only one third of T1D + CD patients reached constant Ab-negativity after CD diagnosis. Achieving Ab-negativity after diagnosis seems to be associated with better metabolic control and growth, supposedly due to a higher adherence to therapy in general.
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Doença Celíaca/imunologia , Diabetes Mellitus Tipo 1/complicações , Hemoglobinas Glicadas/metabolismo , Adolescente , Autoanticorpos/sangue , Doença Celíaca/sangue , Doença Celíaca/complicações , Criança , Diabetes Mellitus Tipo 1/sangue , Feminino , Humanos , Estudos Longitudinais , MasculinoRESUMO
Active fall prevention requires analysis of the mechanisms provoking falls and the subsequent initiation of appropriate counteracting measures. This is crucial for the quality management of all rehabilitation programs. There is primary and secondary fall prevention. For the latter, specific and individualized measures have to be taken after the first fall. We here present a practical approach to fall prevention for a better rehabilitation outcome. Fall prevention intervention represents a key component of rehabilitation programs.
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Acidentes por Quedas/prevenção & controle , Qualidade da Assistência à Saúde , Reabilitação , Feminino , Alemanha , Humanos , Masculino , Prevenção Secundária , Resultado do TratamentoRESUMO
As a neurodevelopmental multifactorial disorder whose prevalence has been increasing worldwide, attention-deficit hyperactivity disorder (ADHD) is considered a public health concern. Methylphenidate (MPH) is the drug of choice for ADHD; however, not all patients respond fully to this treatment. Therefore, exploring the underlying molecular mechanisms involved in ADHD and potential novel therapeutic targets is crucial. Here, we generated induced pluripotent stem cells (iPSCs) from Peripheral Blood Mononuclear Cells (PBMCs) retrieved from four ADHD patients (two MPH responders and two non-responders) using Sendai virus. These lines might be helpful for the in vitro investigation of ADHD pathophysiology in a patient-specific manner.
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The canonical Wnt signaling is an essential pathway that regulates cellular proliferation, maturation, and differentiation during neurodevelopment and maintenance of adult tissue homeostasis. This pathway has been implicated with the pathophysiology of neuropsychiatric disorders and was associated with cognitive processes, such as learning and memory. However, the molecular investigation of the Wnt signaling in functional human neural cell lines might be challenging since brain biopsies are not possible and animal models may not represent the polygenic profile of some neurological and neurodevelopmental disorders. In this context, using induced pluripotent stem cells (iPSCs) has become a powerful tool to model disorders that affect the Central Nervous System (CNS) in vitro, by maintaining patients' genetic backgrounds. In this method paper, we report the development of a virus-free Wnt reporter assay in neural stem cells (NSCs) derived from human iPSCs from two healthy individuals, by using a vector containing a reporter gene (luc2P) under the control of a TCF/LEF (T-cell factor/lymphoid enhancer factor) responsive element. Dose-response curve analysis from this luciferase-based method might be useful when testing the activity of the Wnt signaling pathway after agonists (e.g. Wnt3a) or antagonists (e.g. DKK1) administration, comparing activity between cases and controls in distinct disorders. Using such a reporter assay method may help to elucidate whether neurological or neurodevelopmental mental disorders show alterations in this pathway, and testing whether targeted treatment may reverse these. Therefore, our established assay aims to help researchers on the functional and molecular investigation of the Wnt pathway in patient-specific cell types comprising several neuropsychiatric disorders.
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Attention-deficit hyperactivity disorder is a neurodevelopmental disorder which prevalence has been increasing in the past decades, affecting more than 5% of children, adolescents worldwide. Regarding etiology, polygenic, environmental factors contribute to the occurrence of ADHD even though molecular mechanisms are not known. Understanding the pathophysiology in patient-specific cells is crucial for the discovery of potential predictive markers, the establishment of new therapeutic targets. In this study, we generated further lines from ADHD patients, healthy controls using Sendai virus transduction, which may help on the study of ADHD at the molecular, cellular levels.
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Transtorno do Deficit de Atenção com Hiperatividade , Células-Tronco Pluripotentes Induzidas , Transtornos do Neurodesenvolvimento , Criança , Adolescente , HumanosRESUMO
Ten human induced pluripotent stem cell (iPSC) lines have been derived from five healthy controls matched to a study including Attention-Deficit Hyperactivity Disorder patients (ADHD). Both female and male children and adolescents aged 6-18 years were recruited. Isolated keratinocyte cells from the participants were reprogrammed into iPSCs using non-integrating Sendai virus to deliver the reprogramming factors Oct3/4, Sox2, Klf4 and cMyc.
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Transtorno do Deficit de Atenção com Hiperatividade , Células-Tronco Pluripotentes Induzidas , Adolescente , Diferenciação Celular , Reprogramação Celular , Criança , Feminino , Humanos , Queratinócitos , Fator 4 Semelhante a Kruppel , Masculino , Vírus SendaiRESUMO
Human induced pluripotent stem cell (iPSC) lines have been derived from four male patients with childhood attention-deficit hyperactivity disorder (ADHD). Children and adolescents between the ages 6 and 18 suffering from ADHD were recruited for this work. Isolated keratinocytes or peripheral blood mononuclear cells from the participants were reprogrammed into iPSCs using non-integrating Sendai virus to deliver the reprogramming factors Oct3/4, Sox2, Klf4 and c-Myc.
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Transtorno do Deficit de Atenção com Hiperatividade , Células-Tronco Pluripotentes Induzidas , Adolescente , Diferenciação Celular , Reprogramação Celular , Criança , Humanos , Queratinócitos , Fator 4 Semelhante a Kruppel , Leucócitos Mononucleares , Masculino , Vírus SendaiRESUMO
Immune cells have been implicated in influencing stroke outcomes depending on their temporal dynamics, number, and spatial distribution after ischemia. Depending on their activation status, immune cells can have detrimental and beneficial properties on tissue outcome after stroke, highlighting the need to modulate inflammation towards beneficial and restorative immune responses. Novel dietary therapies may promote modulation of pro- and anti-inflammatory immune cell functions. Among the dietary interventions inspired by the Mediterranean diet, hydroxytyrosol (HT), the main phenolic component of the extra virgin olive oil (EVOO), has been suggested to have antioxidant and anti-inflammatory properties in vitro. However, immunomodulatory effects of HT have not yet been studied in vivo after stroke. The aim of this project is therefore to monitor the therapeutic effect of a HT-enriched diet in an experimental stroke model using non-invasive in vivo multimodal imaging, behavioural phenotyping and cross-correlation with ex vivo parameters. Methods: A total of N = 22 male C57BL/6 mice were fed with either a standard chow (n = 11) or a HT enriched diet (n = 11) for 35 days, following a 30 min transient middle cerebral artery occlusion (tMCAo). T2-weighted (lesion) and perfusion (cerebral blood flow)-/diffusion (cellular density)-weighted MR images were acquired at days 1, 3, 7, 14, 21 and 30 post ischemia. [18F]DPA-714 (TSPO, neuroinflammation marker) PET-CT scans were acquired at days 7, 14, 21 and 30 post ischemia. Infarct volume (mm3), cerebral blood flow (mL/100g/min), apparent diffusion coefficient (10-4·mm2/s) and percentage of injected tracer dose (%ID/mL) were assessed. Behavioural tests (grip test, rotarod, open field, pole test) were performed prior and after ischemia to access therapy effects on sensorimotor functions. Ex vivo analyses (IHC, IF, WB) were performed to quantify TSPO expression, immune cells including microglia/macrophages (Iba-1, F4/80), astrocytes (GFAP) and peripheral markers in serum such as thiobarbituric acid reactive substances (TBARS) and nitric oxide (NO) 35 days post ischemia. Additionally, gene expression of pro- and anti-inflammatory markers were assessed by rt-qPCR, including tspo, cd163, arg1, tnf and Il-1ß. Results: No treatment effect was observed on temporal [18F]DPA-714 uptake within the ischemic and contralateral region (two-way RM ANOVA, p = 0.71). Quantification of the percentage of TSPO+ area by immunoreactivity indicated a slight 2-fold increase in TSPO expression within the infarct region in HT-fed mice at day 35 post ischemia (p = 0.011) correlating with a 2-3 fold increase in Iba-1+ cell population expressing CD163 as anti-inflammatory marker (R2 = 0.80). Most of the GFAP+ cells were TSPO-. Only few F4/80+ cells were observed at day 35 post ischemia in both groups. No significant treatment effect was observed on global ADC and CBF within the infarct and the contralateral region over time. Behavioural tests indicated improved strength of the forepaws at day 14 post ischemia (p = 0.031). Conclusion: An HT-enriched diet significantly increased the number of Iba-1+ microglia/macrophages in the post-ischemic area, inducing higher expression of anti-inflammatory markers while no clear-cut effect was observed. Also, HT did not affect recovery of the cerebrovascular parameters, including ADC and CBF. Altogether, our data indicated that a prolonged dietary intervention with HT, as a single component of the Mediterranean diet, induces molecular changes that may improve stroke outcomes. Therefore, we support the use of the Mediterranean diet as a multicomponent therapy approach after stroke.
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Encéfalo/efeitos dos fármacos , Inflamação/tratamento farmacológico , Álcool Feniletílico/análogos & derivados , Acidente Vascular Cerebral/tratamento farmacológico , Animais , Anti-Inflamatórios/farmacologia , Biomarcadores Tumorais/metabolismo , Encéfalo/metabolismo , Isquemia Encefálica/tratamento farmacológico , Isquemia Encefálica/metabolismo , Modelos Animais de Doenças , Inflamação/metabolismo , Imageamento por Ressonância Magnética/métodos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Microglia/efeitos dos fármacos , Microglia/metabolismo , Álcool Feniletílico/farmacologia , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada/métodos , Tomografia por Emissão de Pósitrons/métodos , Acidente Vascular Cerebral/metabolismoRESUMO
BACKGROUND: Tumor-associated microglia and macrophages (TAMs) and myeloid-derived suppressor cells (MDSCs) are potent immunosuppressors in the glioma tumor microenvironment (TME). Their infiltration is associated with tumor grade, progression, and therapy resistance. Specific tools for image-guided analysis of spatiotemporal changes in the immunosuppressive myeloid tumor compartments are missing. We aimed (i) to evaluate the role of fluorodeoxyglucose (18F)DPA-714* (translocator protein [TSPO]) PET-MRI in the assessment of the immunosuppressive TME in glioma patients, and (ii) to cross-correlate imaging findings with in-depth immunophenotyping. METHODS: To characterize the glioma TME, a mixed collective of 9 glioma patients underwent [18F]DPA-714-PET-MRI in addition to [18F]fluoro-ethyl-tyrosine (FET)-PET-MRI. Image-guided biopsy samples were immunophenotyped by multiparametric flow cytometry and immunohistochemistry. In vitro autoradiography was performed for image validation and assessment of tracer binding specificity. RESULTS: We found a strong relationship (r = 0.84, P = 0.009) between the [18F]DPA-714 uptake and the number and activation level of glioma-associated myeloid cells (GAMs). TSPO expression was mainly restricted to human leukocyte antigen D related-positive (HLA-DR+) activated GAMs, particularly to tumor-infiltrating HLA-DR+ MDSCs and TAMs. [18F]DPA-714-positive tissue volumes exceeded [18F]FET-positive volumes and showed a differential spatial distribution. CONCLUSION: [18F]DPA-714-PET may be used to non-invasively image the glioma-associated immunosuppressive TME in vivo. This imaging paradigm may also help to characterize the heterogeneity of the glioma TME with respect to the degree of myeloid cell infiltration at various disease stages. [18F]DPA-714 may also facilitate the development of new image-guided therapies targeting the myeloid-derived TME.
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Neoplasias Encefálicas , Glioma , Microambiente Tumoral , Adulto , Neoplasias Encefálicas/diagnóstico por imagem , Feminino , Radioisótopos de Flúor , Glioma/diagnóstico por imagem , Humanos , Masculino , Pessoa de Meia-Idade , Tomografia por Emissão de Pósitrons , Receptores de GABA , Estudos RetrospectivosRESUMO
Chronic heart failure (CHF) is a condition characterized by exercise intolerance. The level of activity tolerated by an individual cannot be predicted by classical parameters of left ventricular performance. Therefore, considerable attention has been focused on the role of peripheral factors such as skeletal muscle, which are determinants of work capacity. In recent years, many alterations in the skeletal muscle have been described in patients with chronic heart failure. This knowledge has dramatically changed the treatment of patients with CHF. Previously, patients were asked to avoid excessive strain and physical exercise. Recently, however, patients are asked to participate in a supervised physical training program to increase their exercise capacity and to counteract the molecular changes occurring in the skeletal muscle. This review will focus on molecular and biochemical alterations especially in the skeletal muscle and how these alterations are influenced by exercise training finally contributing to better skeletal muscle performance.
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Insuficiência Cardíaca/patologia , Músculo Esquelético/patologia , Animais , Apoptose , Doença Crônica , Citocinas/metabolismo , Insuficiência Cardíaca/metabolismo , Humanos , Inflamação , Fator de Crescimento Insulin-Like I/metabolismo , Mitocôndrias/metabolismo , Músculo Esquelético/metabolismo , Fosforilação Oxidativa , Estresse Oxidativo , Condicionamento Físico Animal , Complexo de Endopeptidases do Proteassoma/metabolismo , Ubiquitina/metabolismoRESUMO
Myocardial perfusion imaging with single photon emission computed tomography (SPECT) is an established method for the detection and evaluation of coronary artery disease (CAD). State-of-the-art SPECT scanners yield a large number of regional parameters of the left-ventricular myocardium (e.g., blood supply at rest and during stress, wall thickness, and wall thickening during heart contraction) that all need to be assessed by the physician. Today, the individual parameters of this multivariate data set are displayed as stacks of 2D slices, bull's eye plots, or, more recently, surfaces in 3D, which depict the left-ventricular wall. In all these visualizations, the data sets are displayed side-by-side rather than in an integrated manner, such that the multivariate data have to be examined sequentially and need to be fused mentally. This is time consuming and error-prone. In this paper we present an interactive 3D glyph visualization, which enables an effective integrated visualization of the multivariate data. Results from semiotic theory are used to optimize the mapping of different variables to glyph properties. This facilitates an improved perception of important information and thus an accelerated diagnosis. The 3D glyphs are linked to the established 2D views, which permit a more detailed inspection, and to relevant meta-information such as known stenoses of coronary vessels supplying the myocardial region. Our method has demonstrated its potential for clinical routine use in real application scenarios assessed by nuclear physicians.
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Doença da Artéria Coronariana/diagnóstico por imagem , Interpretação de Imagem Assistida por Computador/métodos , Imageamento Tridimensional/métodos , Reconhecimento Automatizado de Padrão/métodos , Tomografia Computadorizada de Emissão de Fóton Único/métodos , Interface Usuário-Computador , Disfunção Ventricular Esquerda/diagnóstico por imagem , Algoritmos , Inteligência Artificial , Gráficos por Computador , Doença da Artéria Coronariana/complicações , Humanos , Aumento da Imagem/métodos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Disfunção Ventricular Esquerda/etiologiaRESUMO
OBJECTIVE: In chronic heart failure (CHF) the myocardial expression of the inflammatory cytokine tumor necrosis factor alpha (TNF-alpha), which is thought to contribute to myocardial remodeling, was found to be increased. However, it is unknown whether the E3-ubiquitin ligases MAFbx and Murf-1 are involved in this remodeling process and whether their expression is regulated by TNF-alpha. METHODS: Rats underwent ligation of the left coronary artery to induce CHF or were sham-operated. The expression of MAFbx/Murf-1 and troponin I was analyzed by RT-PCR and Western blotting in the non-infarcted area of the left ventricle. In cell culture experiments the potency of TNF-alpha to stimulate Murf-1/MAFbx expression, the intracellular signaling pathway, and the involvement of the E3-ligases for the impairment of contractility were assessed. RESULTS: In CHF the myocardial expression of TNF-alpha was elevated 3.1-fold as compared to control. This was associated with a 4.5-fold and 2.7-fold increase in MAFbx and Murf-1 expression, respectively. A positive correlation between TNF-alpha and the expression of MAFbx or Murf-1 was evident. In neonatal rat cardiomyocytes, TNF-alpha induced the expression of MAFbx through p38MAPK-dependent pathways, whereas the induction of Murf-1 required the activation of the p42/44 MAPK pathway. Exposure of cardiomyocytes to TNF-alpha resulted in troponin I ubiquitinylation, subsequent degradation, and a decline in contractility. This was completely abrogated by siRNAs against Murf-1/MAFbx. CONCLUSION: TNF-alpha, which is increasingly expressed in CHF, induces troponin I degradation through a MAFbx/Murf-1-dependent pathway. This was associated with an impairment of contractility and might be one mechanism involved in the adverse remodeling process in CHF.
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Insuficiência Cardíaca/metabolismo , Proteínas Musculares/análise , Miocárdio/química , Proteínas Ligases SKP Culina F-Box/análise , Ubiquitina-Proteína Ligases/análise , Animais , Animais Recém-Nascidos , Western Blotting/métodos , Ecocardiografia , Flavonoides/farmacologia , Expressão Gênica/efeitos dos fármacos , Insuficiência Cardíaca/imunologia , Imidazóis/farmacologia , Proteína Quinase 1 Ativada por Mitógeno/antagonistas & inibidores , Modelos Animais , Proteínas Musculares/genética , Piridinas/farmacologia , Interferência de RNA , RNA Mensageiro/análise , Ratos , Ratos Endogâmicos WKY , Proteínas Ligases SKP Culina F-Box/genética , Proteínas com Motivo Tripartido , Troponina I/análise , Troponina I/genética , Fator de Necrose Tumoral alfa/metabolismo , Fator de Necrose Tumoral alfa/farmacologia , Ubiquitina-Proteína Ligases/genética , Disfunção Ventricular Esquerda , Proteínas Quinases p38 Ativadas por Mitógeno/antagonistas & inibidoresRESUMO
Noninvasive monitoring of tumor therapy response helps in developing personalized treatment strategies. Here, we performed sequential PET and diffusion-weighted MRI to evaluate changes induced by a FOLFOX-like combination chemotherapy in colorectal cancer xenografts, to identify the cellular and molecular determinants of these imaging biomarkers. Methods: Tumor-bearing CD1 nude mice, engrafted with FOLFOX-sensitive Colo205 colorectal cancer xenografts, were treated with FOLFOX (5-fluorouracil, leucovorin, and oxaliplatin) weekly. On days 1, 2, 6, 9, and 13 of therapy, tumors were assessed by in vivo imaging and ex vivo analyses. In addition, HCT116 xenografts, which did not respond to the FOLFOX treatment, were imaged on day 1 of therapy. Results: In Colo205 xenografts, FOLFOX induced a profound increase in uptake of the proliferation PET tracer 3'-deoxy-3'-18F-fluorothymidine (18F-FLT) accompanied by increases in markers for proliferation (Ki-67, thymidine kinase 1) and for activated DNA damage response (γH2AX), whereas the effect on cell death was minimal. Because tracer uptake was unaltered in the HCT116 model, these changes appear to be specific for tumor response. Conclusion: We demonstrated that 18F-FLT PET can noninvasively monitor cancer treatment-induced molecular alterations, including thymidine metabolism and DNA damage response. The cellular or imaging changes may not, however, be directly related to therapy response as assessed by volumetric measurements.
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Artefatos , Neoplasias Colorretais/tratamento farmacológico , Neoplasias Colorretais/metabolismo , Didesoxinucleosídeos/metabolismo , Timidina/metabolismo , Animais , Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Transporte Biológico/efeitos dos fármacos , Transformação Celular Neoplásica , Neoplasias Colorretais/diagnóstico por imagem , Neoplasias Colorretais/patologia , Imagem de Difusão por Ressonância Magnética , Feminino , Fluoruracila/farmacologia , Fluoruracila/uso terapêutico , Células HCT116 , Humanos , Leucovorina/farmacologia , Leucovorina/uso terapêutico , Camundongos , Compostos Organoplatínicos/farmacologia , Compostos Organoplatínicos/uso terapêuticoRESUMO
Although metal-metal bonding is important in the chemistry of both solid-state intermetallic compounds and molecular species, the study of this bonding is limited by the compounds available and it is rarely possible to identify connections between these two areas. In this study, molecular intermetalloids [Ln(ReCp(2))(3)] (Ln = Sm, Lu and La) have been synthesized that contain lanthanoid metals bound only to transition metals. Although they are highly reactive species, such lanthanoid-core transition-metal-shell compounds can be stable in solution. They mimic the bonding situation of intermetallic compounds, as revealed by a direct comparison of molecular and solid state lanthanoid-transition metal bonding.
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Ciclopentanos/química , Lantânio/química , Lutécio/química , Compostos Organometálicos/química , Rênio/química , Samário/química , Ciclopentanos/síntese química , Espectroscopia de Ressonância Magnética , Modelos Moleculares , Compostos Organometálicos/síntese química , Teoria QuânticaRESUMO
The reactions of the nickel complex [Ni(2)(iPr(2)Im)4(COD)] 1 with organonitriles smoothly and irreversibly proceed via intermediates with eta(2)-coordinated organonitrile ligands such as [Ni(iPr(2)Im)2(eta(2)-(CN)-PhCN)] 2 and [Ni(iPr(2)Im)2(eta(2)-(CN)-pTolCN)] 4 to yield aryl cyanide complexes of the type trans-[Ni(iPr(2)Im)2(CN)(Ar)] (Ar = Ph 3, pTol 5, 4-CF(3)C(6)H(4) 6, 2,4-(OMe)2C(6)H(3) 7, 2-C(4)H(3)O 8, 2-C(5)H(4)N 9). The compounds 3, 7, 9 and have been structurally characterized. For the conversion of 2 to 3 a free activation enthalpy DeltaG++(328 K) of 103.47 +/- 0.79 kJ mol(-1) was calculated from time dependent NMR spectroscopy. The analogous reaction of arylnitriles with electron releasing substituents or heteroaromatic organonitriles is significantly faster compared to the reaction with benzonitrile or toluonitrile. The reactions of 1 with acetonitrile or trimethylsilyl cyanide afforded [Ni(iPr(2)Im)2(CN)(Me)] 10 and structurally characterized [Ni(iPr(2)Im)2(CN)(SiMe(3))] 11. The usage of an organonitrile with a longer alkyl chain, adiponitrile, yielded [Ni(iPr(2)Im)2(eta(2)-(CN)-NCC(4)H(8)CN)] 12 as well as the C-CN activation product [Ni(iPr(2)Im)2(CN)(C(4)H(8)CN)]13 in thermal and photochemical reactions, although this pathway seems to be significantly interfered with by decomposition pathways under the formation of the dicyanide complex [Ni(iPr(2)Im)(2)(CN)(2)] 14.