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The genus Sinocyclocheilus, comprising a large radiation of freshwater cavefishes, are well known for their presence of regressive features (e.g. variable eye reduction). Fewer constructive features are known, such as the expansion of the lateral line system (LLS), which is involved in detecting water movements. The precise relationship between LLS expansion and cave adaptation is not well understood. Here, we examine morphology and LLS-mediated behaviour in Sinocyclocheilus species characterized by broad variation in eye size, habitat and geographical distribution. Using live-staining techniques and automated behavioural analyses, we examined 26 Sinocyclocheilus species and quantified neuromast organ number, density and asymmetry within a phylogenetic context. We then examined how these morphological features may relate to wall-following, an established cave-associated behaviour mediated by the lateral line. We show that most species demonstrated laterality (i.e. asymmetry) in neuromast organs on the head, often biased to the right. We also found that wall-following behaviour was distinctive, particularly among eyeless species. Patterns of variation in LLS appear to correlate with the degree of eye loss, as well as geographical distribution. This work reveals that constructive LLS evolution is convergent across distant cavefish taxa and may mediate asymmetric behavioural features that enable survival in stark subterranean microenvironments.
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Cipriniformes , Animais , FilogeniaRESUMO
Cancer vasculature is immature, disorganized and hyperpermeable and can serve as a target for anti-cancer therapies. Vascular disrupting agents (VDAs) are tubulin protein binding and depolymerizing agents that induce rapid tumoral vascular shutdown and subsequent cancer necrosis. However, two clinical problems exist with all VDAs, i.e. 1) incomplete anticancer effect and 2) dose-dependent toxicity. To tackle these problems, in our ongoing research, a novel VDA C118P is applied by transarterial administration of half the intravenous dose in rabbits with implanted VX2 liver tumor to assess its therapeutic efficacy. Nearly complete tumor necrosis was achieved by only a single arterial dose of C118P at 5 mg/kg, which was documented in a representative case by in vivo digital subtraction arteriogram (DSA) and magnetic resonance imaging (MRI), and further confirmed by ex vivo microangiogram and histopathology. This convincing and promising preliminary outcome would warrant further comprehensive studies to explore the potentials of VDAs by transarterial administration either in mono-drug or in combination for management of solid cancers.
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Inibidores da Angiogênese/administração & dosagem , Imidazóis/administração & dosagem , Neoplasias Hepáticas/tratamento farmacológico , Neovascularização Patológica/tratamento farmacológico , Éteres Fenílicos/administração & dosagem , Angiografia Digital , Animais , Linhagem Celular Tumoral , Modelos Animais de Doenças , Ensaios de Seleção de Medicamentos Antitumorais , Artéria Hepática/diagnóstico por imagem , Humanos , Injeções Intra-Arteriais , Fígado/diagnóstico por imagem , Fígado/efeitos dos fármacos , Fígado/patologia , Neoplasias Hepáticas/irrigação sanguínea , Neoplasias Hepáticas/diagnóstico , Neoplasias Hepáticas/patologia , Imageamento por Ressonância Magnética , Neovascularização Patológica/diagnóstico , Neovascularização Patológica/patologia , CoelhosRESUMO
Vascular disrupting agents (VDAs) have entered clinical trials for over 15 years. As the leading VDA, combretastatin A4 phosphate (CA4P) has been evaluated in combination with chemotherapy and molecular targeting agents among patients with ovarian cancer, lung cancer and thyroid cancer, but still remains rarely explored in human liver cancers. To overcome tumor residues and regrowth after CA4P monotherapy, a novel dual targeting pan-anticancer theragnostic strategy, i.e., OncoCiDia, has been developed and shown promise previously in secondary liver tumor models. Animal model of primary liver cancer is time consuming to induce, but of value for more closely mimicking human liver cancers in terms of tumor angiogenesis, histopathological heterogeneity, cellular differentiation, tumor components, cancer progression and therapeutic response. Being increasingly adopted in VDA researches, multiparametric magnetic resonance imaging (MRI) provides imaging biomarkers to reflect in vivo tumor responses to drugs. In this article as a chapter of a doctoral thesis, we overview the construction and clinical relevance of primary and secondary liver cancer models in rodents. Target selection for CA4P therapy assisted by enhanced MRI using hepatobiliary contrast agents (CAs), and therapeutic efficacy evaluated by using MRI with a non-specific contrast agent, dynamic contrast enhanced (DCE) imaging, diffusion weighted imaging (DWI) are also described. We then summarize diverse responses among primary hepatocellular carcinomas (HCCs), secondary liver and pancreatic tumors to CA4P, which appeared to be related to tumor size, vascularity, and cellular differentiation. In general, imaging-histopathology correlation studies allow to conclude that CA4P tends to be more effective in secondary liver tumors and in more differentiated HCCs, but less effective in less differentiated HCCs and implanted pancreatic tumor. Notably, cirrhotic liver may be responsive to CA4P as well. All these could be instructive for future clinical trials of VDAs.
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To evaluate hepatobiliary-specific contrast agent (CA) mangafodipir trisodium (Mn-DPDP)-enhanced magnetic resonance imaging (MRI) for predicting the therapeutic efficacy of the vascular disrupting agent combretastatin A4 phosphate (CA4P) in rats with primary and secondary liver tumors, 36 primary hepatocellular carcinomas (HCCs) were raised by diethylnitrosamine gavage in 16 male rats, in 6 of which one rhabdomyosarcomas (R1) was intrahepatically implanted as secondary liver tumors. On a 3.0T MR scanner with a wrist coil, tumors were monitored weekly by T2-/T1-weighted images (T2WI/T1WI) and characterized by Mn-DPDP-enhanced MRI. CA4P-induced intratumoral necrosis was depicted by nonspecific gadoterate meglumine (Gd-DOTA)-enhanced MRI before and 12 h after therapy. Changes of tumor-to-liver contrast (ΔT/L) on Mn-DPDP-enhanced images were analyzed. In vivo MRI findings were verified by postmortem microangiography and histopathology. Rat models of primary HCCs in a full spectrum of differentiation and secondary R1 liver tumors were successfully generated. Mn-DPDP-enhanced ΔT/L was negatively correlated with HCC differentiation grade (P < 0.01). After treatment with CA4P, more extensive tumoral necrosis was found in highly differentiated HCCs than that in moderately and poorly differentiated ones (P < 0.01); nearly complete necrosis was induced in secondary liver tumors. Mn-DPDP-enhanced MRI may help in imaging diagnosis of primary and secondary liver malignancies of different cellular differentiations and further in predicting CA4P therapeutic efficacy in primary HCCs and intrahepatic metastases.
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Cancer remains a major cause of death globally. Given its relapsing and fatal features, curing cancer seems to be something hardly possible for the majority of patients. In view of the development in cancer therapies, this article summarizes currently available cancer therapeutics and cure potential by cancer type and stage at diagnosis, based on literature and database reviews. Currently common cancer therapeutics include surgery, chemotherapy, radiotherapy, targeted therapy, and immunotherapy. However, treatment with curative intent by these methods are mainly eligible for patients with localized disease or treatment-sensitive cancers and therefore their contributions to cancer curability are relatively limited. The prognosis for cancer patients varies among different cancer types with a five-year relative survival rate (RSR) of more than 80% in thyroid cancer, melanoma, breast cancer, and Hodgkin's lymphoma. The most dismal prognosis is observed in patients with small-cell lung cancer, pancreatic cancer, hepatocellular carcinoma, oesophagal cancer, acute myeloid leukemia, non-small cell lung cancer, and gastric cancer with a five-year RSR ranging between 7% and 28%. The current review is intended to provide a general view about how much we have achieved in curing cancer as regards to different therapies and cancer types. Finally, we propose a small molecule dual-targeting broad-spectrum anticancer strategy called OncoCiDia, in combination with emerging highly sensitive liquid biopsy, with theoretical curative potential for the management of solid malignancies, especially at the micro-cancer stage.
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AIM: To compare therapeutic responses of a vascular-disrupting-agent, combretastatin-A4-phosphate (CA4P), among hepatocellular carcinomas (HCCs) and implanted rhabdomyosarcoma (R1) in the same rats by magnetic-resonance-imaging (MRI), microangiography and histopathology. METHODS: Thirty-six HCCs were created by diethylnitrosamine gavage in 14 rats that were also intrahepatically implanted with one R1 per rat as monitored by T2-/T1-weighted images (T2WI/T1WI) on a 3.0T clinical MRI-scanner. Vascular response and tumoral necrosis were detected by dynamic contrast-enhanced (DCE-) and CE-MRI before, 1 h after and 12 h after CA4P iv at 10 mg/kg (treatment group n = 7) or phosphate-buffered saline at 1.0 mL/kg (control group n = 7). Tumor blood supply was calculated by a semiquantitative DCE parameter of area under the time signal intensity curve (AUC30). In vivo MRI findings were verified by postmortem techniques. RESULTS: On CE-T1WIs, unlike the negative response in all tumors of control animals, in treatment group CA4P caused rapid extensive vascular shutdown in all R1-tumors, but mildly or spottily in HCCs at 1 h. Consequently, tumor necrosis occurred massively in R1-tumors but patchily in HCCs at 12 h. AUC30 revealed vascular closure (66%) in R1-tumors at 1 h (P < 0.05), followed by further perfusion decrease at 12 h (P < 0.01), while less significant vascular clogging occurred in HCCs. Histomorphologically, CA4P induced more extensive necrosis in R1-tumors (92.6%) than in HCCs (50.2%) (P < 0.01); tumor vascularity heterogeneously scored +~+++ in HCCs but homogeneously scored ++ in R1-tumors. CONCLUSION: This study suggests superior performance of CA4P in metastatic over primary liver cancers, which could guide future clinical applications of vascular-disrupting-agents.â.
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Antineoplásicos Fitogênicos/uso terapêutico , Carcinoma Hepatocelular/tratamento farmacológico , Neoplasias Hepáticas/tratamento farmacológico , Neovascularização Patológica/tratamento farmacológico , Rabdomiossarcoma/tratamento farmacológico , Estilbenos/uso terapêutico , Angiografia , Animais , Antineoplásicos Fitogênicos/farmacologia , Carcinoma Hepatocelular/irrigação sanguínea , Carcinoma Hepatocelular/induzido quimicamente , Carcinoma Hepatocelular/patologia , Meios de Contraste/administração & dosagem , Dietilnitrosamina/toxicidade , Humanos , Fígado/diagnóstico por imagem , Fígado/patologia , Neoplasias Hepáticas/irrigação sanguínea , Neoplasias Hepáticas/induzido quimicamente , Neoplasias Hepáticas/patologia , Neoplasias Hepáticas Experimentais/induzido quimicamente , Neoplasias Hepáticas Experimentais/diagnóstico por imagem , Neoplasias Hepáticas Experimentais/tratamento farmacológico , Neoplasias Hepáticas Experimentais/patologia , Imageamento por Ressonância Magnética/métodos , Masculino , Neovascularização Patológica/patologia , Ratos , Rabdomiossarcoma/irrigação sanguínea , Rabdomiossarcoma/patologia , Rabdomiossarcoma/secundário , Estilbenos/farmacologia , Resultado do Tratamento , Microambiente Tumoral/efeitos dos fármacos , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
To better inform the next clinical trials of vascular disrupting agent combretastatin-A4-phosphate (CA4P) in patients with hepatic malignancies, this preclinical study aimed at evaluating CA4P therapeutic efficacy in rats with primary hepatocellular carcinomas (HCCs) of a full spectrum of differentiation and vascularity by magnetic resonance imaging (MRI), microangiography and histopathology. Ninety-six HCCs were raised in 25 rats by diethylnitrosamine gavage. Tumor growth was monitored by T2-/T1-weighted-MRI (T2WI, T1WI) using a 3.0 T scanner. Early vascular response and later intratumoral necrosis were detected by dynamic-contrast-enhanced (DCE) MRI and diffusion-weighted-imaging (DWI) before, 1 and 12 hr after CA4P iv-administration. In vivo MRI-findings were validated by postmortem-techniques. Multi-parametric MRI revealed rapid CA4P-induced tumor vascular shutdown within 1 hr, followed by variable intratumoral necrosis at 12 hr. Tumor volumes decreased by 10% at 1 hr (p < 0.05), but resumed at 12 hr. Correlations of semi-quantitative DCE parameter initial-area-under-the-gadolinium-curve (IAUGC30) with histopathology proved partial vascular closure and compensational reopening (p < 0.05). The higher grades of vascularity prevented those residual tumor tissues from CA4P-caused ischemic necrosis. By histopathology using a 4-scale cellular-differentiation criteria and a 4-grade tumor-vascularity classification, percentage of CA4P-induced necrosis negatively correlated with HCC differentiation (r = -0.404, p < 0.001) and tumor vascularity (r = -0.370, p < 0.001). Ordinal-logistic-regression helped to predict early tumor responses to CA4P in terms of tumoral differentiation and vascularity. Our study demonstrated that CA4P could induce vascular shutdown in primary HCCs within 1 hr, resulting in various degrees of tumor necrosis at 12 hr. MRI as a real-time imaging biomarker may help to define tumor vascularity and differentiation and further to predict CA4P therapeutic outcomes.
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Carcinoma Hepatocelular/tratamento farmacológico , Neoplasias Hepáticas/tratamento farmacológico , Imageamento por Ressonância Magnética/métodos , Neovascularização Patológica/prevenção & controle , Estilbenos/farmacologia , Animais , Antineoplásicos Fitogênicos/farmacologia , Carcinoma Hepatocelular/irrigação sanguínea , Carcinoma Hepatocelular/patologia , Meios de Contraste , Humanos , Neoplasias Hepáticas/irrigação sanguínea , Neoplasias Hepáticas/patologia , Masculino , Ratos , Ratos Sprague-Dawley , Carga Tumoral , Células Tumorais CultivadasRESUMO
Foxo transcription factors promote protein breakdown and atrophy of skeletal muscle fibers. Foxo transcriptional effectiveness is largely determined by phosphorylation-dependent nucleo-cytoplasmic shuttling. Imaging Foxo1-green fluorescent protein (GFP) over time in 124 nuclei in 68 multinucleated adult skeletal muscle fibers under control culture conditions reveals large variability between fibers in Foxo1-GFP nucleo-cytoplasmic concentration ratio (N/C) and in the apparent rate coefficient ( kI') for Foxo1-GFP unidirectional nuclear influx (measured with efflux blocked by leptomycin B). Pairs of values of N/C or of kI' from different nuclei in the same fiber were essentially the same, but only weakly correlated in nuclei from different fibers in the same culture well. Thus, fiber to fiber variability of cellular factors, but not extracellular factors, determines Foxo1 distribution. Over all nuclei, N/C and kI' were closely proportional, indicating that kI' is the major determinant of Foxo1 distribution. IGF-I activation of Foxo kinase Akt reduces variability by decreasing kI' and N/C in all fibers. However, inhibiting Akt did not drive kI' uniformly high, indicating other pathways in Foxo1 regulation.
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Núcleo Celular/metabolismo , Citoplasma/metabolismo , Proteína Forkhead Box O1/metabolismo , Fibras Musculares Esqueléticas/metabolismo , Transporte Ativo do Núcleo Celular , Animais , Feminino , Proteína Forkhead Box O1/genética , Proteínas de Fluorescência Verde/metabolismo , Técnicas In Vitro , Fator de Crescimento Insulin-Like I/farmacologia , Cinética , Camundongos , Modelos Biológicos , Fibras Musculares Esqueléticas/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-akt/metabolismo , Proteínas Recombinantes de Fusão/metabolismoRESUMO
Different causative factors acting on the pancreas can result in diseases such as pancreatitis, diabetes and pancreatic tumors. The high incidence and mortality of pancreatic diseases have placed diagnostic imaging in a crucial position in daily clinical practice. In this mini-review article different pancreatic imaging techniques are discussed, from the standard clinical imaging modalities and state of the art clinical magnetic resonance imaging techniques to current situations in pre-clinical pancreatic imaging studies. In particular, the challenges of pre-clinical rodent pancreatic imaging are addressed, with both the image acquisition techniques and the post-processing methods for rodent pancreatic imaging elaborated.
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BACKGROUND: Tumours growing in organs of different vascular environment could exhibit diverse responses to vascular disrupting agent (VDA). This study was aimed to identify in vivo imaging biomarkers for evaluation of pancreatic and hepatic tumours and comparison of their responses to a VDA Combretastatin A4 Phosphate (CA4P) using multiparametric MRI. METHODS: Male WAG/Rij rats were used for orthotopic pancreatic head tumour and hepatic tumour implantation; tumour growth was monitored by 3D isotropic MRI using a 3.0-T clinic scanner. Therapeutic intervention using CA4P was investigated by in vivo quantitative MRI measurements including T2/T1 relaxation mapping, diffusion kurtosis imaging and dynamic contrast-enhancement (DCE) imaging. Animals were scarified 10 h after CA4P treatment for ex vivo validation using microangiography and histomorphology. RESULTS: State-of-the-art clinical MRI protocols were successfully adapted for imaging small animal tumour with high reliability. One hour after CA4P injection, marked vascular shutdown was detected with DCE MRI in both pancreatic and hepatic tumours. However, 10 h later, therapeutic necrosis was limited in pancreatic tumours compared with that in hepatic tumours (P<0.01). Heterogeneous therapeutic changes were depicted in tumour lesions using pixel-wise Tofts model, which was generated from dynamic T1 mapping. In addition, tumour responses including haemorrhage, oedema and necrosis were detected using quantitative T2/T1 relaxation maps and diffusion kurtosis images, and were validated using histomorphology. CONCLUSIONS: Using multiparametric imaging biomarkers, hepatic tumours were found to be significantly more responsive to CA4P than pancreatic tumours, which could be of reference for designing future clinical trials on this agent.
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Antineoplásicos Fitogênicos/farmacologia , Neoplasias Hepáticas/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Neovascularização Patológica/diagnóstico por imagem , Neoplasias Pancreáticas/diagnóstico por imagem , Estilbenos/farmacologia , Aloenxertos , Angiografia , Animais , Processamento de Imagem Assistida por Computador , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/patologia , Neovascularização Patológica/tratamento farmacológico , Neovascularização Patológica/patologia , Neoplasias Pancreáticas/tratamento farmacológico , Neoplasias Pancreáticas/patologia , RatosRESUMO
We sought to investigate anticancer efficacy of a vascular disrupting agent (VDA) combretastatin A-4 phosphate (CA4P) in relation to tumor size among hepatocellular carcinomas (HCCs) in rats using magnetic resonance imaging (MRI) and postmortem techniques. Nineteen rats with 43 chemically-induced HCCs of 2.8-20.9 mm in size on liver cirrhosis received CA4P intravenously at 10 mg/kg. Tumor-diameter was measured by T2-weighted imaging (T2WI) to define microcancers (< 5 mm) versus larger HCCs. Vascular responses and tissue necrosis were detected by diffusion-weighted imaging (DWI), contrast-enhanced T1-weighted imaging (CE-T1WI) and dynamic contrast enhanced (DCE-) MRI, which were validated by microangiography and histopathology. MRI revealed nearly complete necrosis in 5 out of 7 micro-HCCs, but diverse therapeutic necrosis in larger HCCs with a positive correlation with tumor size. Necrosis in micro-HCCs was 36.9% more than that in larger HCCs. While increased diffusion coefficient (ADCdiff) suggested tumor necrosis, perfusion coefficient (ADCperf) indicated sharply decreased blood perfusion in cirrhotic liver together with a reduction in micro-HCCs. DCE revealed lowered tumor blood flow from intravascular into extravascular extracellular space (EES). Microangiography and histopathology revealed hypo- and hypervascularity in 4 and 3 micro-HCCs, massive, partial and minor degrees of tumoral necrosis in 5, 1 and 1 micro-HCCs respectively, and patchy necrotic foci in cirrhotic liver. CD34-PAS staining implicated that poorly vascularized micro-HCCs growing on liver cirrhosis tended to respond better to CA4P treatment. In this study, more complete CA4P-response occurred unexpectedly in micro-HCCs in rats, along with CA4P-induced necrotic foci in cirrhotic liver. These may help to plan clinical applications of VDAs in patients with HCCs and liver cirrhosis.
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BACKGROUND: This study aims to evaluate the short-term efficacy of concurrent chemoradiotherapy (CCRT) in primary fallopian tube carcinoma (PFTC) using magnetic resonance diffusion-weighted imaging (MR-DWI). PATIENTS AND METHODS: Total abdominal irradiation was performed for 61 PFTC patients after surgery, and paclitaxel and carboplatin were used for CCRT. According to the response evaluation criteria in solid tumors (RECIST1.1), patients were divided into a sensitive (n = 36) and a resistant group (n = 25). Pearson correlation analysis was conducted to assess the correlations of tumor regression rate with apparent diffusion coefficient (ADC)pre, ADCpost, and ∆ADCpost. The efficacy of CCRT in PFTC using MR-DWI was evaluated by ROC curve, logistic regression analysis, Kaplan-Meier survival curve, and Cox regression model. RESULTS: The ADCpre in both the sensitive and the resistant group was negatively associated with the tumor regression rate (r = -0.508), while the ADCpost (r = 0.454) and ∆ADCpost (r = 0.769) were positively associated with the tumor regression rate (all p < 0.05). Histopathological type, FIGO stage, lymphatic metastasis, tumor regression rate, ADCpre, ADCpost, and ∆ADCpost were confirmed as key factors for CCRT in PFTC (all p < 0.05). CONCLUSION: Our retrospective study demonstrates the predictive value of MR-DWI in CCRT for PFTC patients.
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Quimiorradioterapia/métodos , Imagem de Difusão por Ressonância Magnética/métodos , Monitoramento de Medicamentos/métodos , Neoplasias das Tubas Uterinas/diagnóstico por imagem , Neoplasias das Tubas Uterinas/terapia , Neoplasias das Tubas Uterinas/patologia , Feminino , Humanos , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Estudos Retrospectivos , Sensibilidade e Especificidade , Resultado do TratamentoRESUMO
Background. Lipiodol has been applied for decades in transarterial chemoembolization to treat liver malignancies, but its intrahepatic pathway through arterioportal shunt (APS) in the liver has not been histologically revealed. This rodent experiment was conducted to provide evidence for the pathway of Lipiodol delivered through the hepatic artery (HA) but found in the portal vein (PV) and to elucidate the observed unidirectional APS. Methods. Thirty rats were divided into 5 groups receiving systemic or local arterial infusion of red-stained iodized oil (RIO) or its hydrosoluble substitute barium sulfate suspension (BSS), or infusion of BSS via the PV, monitored by real-time digital radiography. Histomorphology of serial frozen and paraffin sections was performed and quantified. Results. After HA infusion, RIO and BSS appeared extensively in PV lumens with peribiliary vascular plexus (PVP) identified as the responsible anastomotic channel. After PV infusion, BSS appeared predominantly in the PV and surrounding sinusoids and to a much lesser extent in the PVP and HA (P < 0.001). Fluid mechanics well explains the one-way-valve phenomenon of APS. Conclusions. Intravascularly injected rat livers provide histomorphologic evidences: (1) the PVP exists in between the HA and PV, which is responsible to the APS of Lipiodol; and (2) the intrahepatic vascular inflow appears HA-PVP-PV unidirectional without a physical one-way valve, which can be postulated by the fluid mechanics.
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Fígado/irrigação sanguínea , Fígado/diagnóstico por imagem , Microcirculação , Angiografia , Animais , Sulfato de Bário/química , Fenômenos Biomecânicos , Meios de Contraste/química , Óleo Etiodado/química , Feminino , Artéria Hepática/diagnóstico por imagem , Óleo Iodado/química , Masculino , Modelos Teóricos , Veia Porta/diagnóstico por imagem , Ratos , Ratos Sprague-DawleyRESUMO
Biomarkers involved in alcohol-induced oxidative stress play an important role in alcoholic liver disease prevention and diagnosis. Alcohol-induced oxidative stress in human liver L-02 cells was used to discover the potential biomarkers. Metabolites from L-02 cells induced by alcohol were measured by high-performance liquid chromatography and mass spectrometry. Fourteen metabolites that allowed discrimination between control and model groups were discovered by multivariate statistical data analysis (i.e. principal components analysis, orthogonal partial least-squares discriminate analysis). Based on the retention time, UV spectrum and LC-MS findings of the samples and compared with the authentic standards, eight biomarkers involved in alcohol-induced oxidative stress, namely, malic acid, oxidized glutathione, γ-glutamyl-cysteinyl-glycine, adenosine triphosphate, phenylalanine, adenosine monophosphate, nitrotyrosine and tryptophan, were identified. These biomarkers offered important targets for disease diagnosis and other researches.
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Biomarcadores/metabolismo , Etanol/farmacologia , Metabolômica , Estresse Oxidativo/efeitos dos fármacos , Linhagem Celular , Cromatografia Líquida de Alta Pressão , Humanos , Espectrometria de Massas , Espécies Reativas de Oxigênio/metabolismoRESUMO
Radiofrequency ablation (RFA) is a minimally invasive thermal therapy for the treatment of cancer, hyperopia, and cardiac tachyarrhythmia. In RFA, the power delivered to the tissue is a key parameter. The objective of this study was to establish a methodology for the finite element modeling of RFA with constant power. Because of changes in the electric conductivity of tissue with temperature, a nonconventional boundary value problem arises in the mathematic modeling of RFA: neither the voltage (Dirichlet condition) nor the current (Neumann condition), but the power, that is, the product of voltage and current was prescribed on part of boundary. We solved the problem using Lagrange multiplier: the product of the voltage and current on the electrode surface is constrained to be equal to the Joule heating. We theoretically proved the equality between the product of the voltage and current on the surface of the electrode and the Joule heating in the domain. We also proved the well-posedness of the problem of solving the Laplace equation for the electric potential under a constant power constraint prescribed on the electrode surface. The Pennes bioheat transfer equation and the Laplace equation for electric potential augmented with the constraint of constant power were solved simultaneously using the Newton-Raphson algorithm. Three problems for validation were solved. Numerical results were compared either with an analytical solution deduced in this study or with results obtained by ANSYS or experiments. This work provides the finite element modeling of constant power RFA with a firm mathematical basis and opens pathway for achieving the optimal RFA power.
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Ablação por Cateter , Análise de Elementos Finitos , Condutividade Elétrica , Eletrodos , Temperatura Alta , HumanosRESUMO
The purpose of this study was to investigate the reliability of 3D isotropic MRI and quantitative multi-parametric MRI characterization on an orthotopic pancreatic head tumor model in rats. 3D isotropic T2 -weighted MRI was performed as a routine for tumor longitudinal follow-up and volume estimation. Common bile duct diameter was measured from 3D multiplanar reconstruction. Quantitative multi-parametric measurements including pixel-wise T2 , T1 relaxivity, apparent diffusion coefficient (ADC) and apparent diffusion kurtosis mapping were performed twice throughout tumor growth. Semi-quantitative and quantitative analyses based on an extended Tofts model were applied to region-of-interest-based dynamic contrast-enhanced imaging, followed by contrast ratio measurement on standard contrast-enhanced imaging. Moreover, low-level texture-based analysis was inspected for T2 , T1 , ADC and contrast ratio measurements. Results indicated that multi-parametric MRI showed good reproducibility for tumor characterization; the measurements were not affected by tumor growth. Tumor growth was further confirmed with histology examinations. To conclude, state-of-the-art clinical MRI techniques were translated to this preclinical tumor model with high reliability, and have paved the way for translational oncology studies on this tumor model.
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Imagem de Difusão por Ressonância Magnética/métodos , Interpretação de Imagem Assistida por Computador/métodos , Imageamento Tridimensional/métodos , Imagem Multimodal/métodos , Neoplasias Pancreáticas/diagnóstico por imagem , Neoplasias Pancreáticas/patologia , Animais , Linhagem Celular Tumoral , Aumento da Imagem/métodos , Masculino , Ratos , Reprodutibilidade dos Testes , Sensibilidade e EspecificidadeRESUMO
AIM: To facilitate translational research on cholelithiasis, we have developed a rat model of human gallstones by exploiting the unique biliopancreatic features of this species. METHODS: Under anesthesia, 16 adult rats of equal genders underwent two times of abdominal surgery. First, their common bile duct (CBD) was ligated to cause cholestasis by total biliary obstruction (TBO). On day 0, 1, 3, 7, 14, 21 and 28 after TBO, magnetic resonance imaging (MRI) was conducted to monitor the dilatation of the CBD, and blood was sampled to analyze total serum bilirubin (TSB). Secondly, on day 30, the abdomen was re-opened and gallstone(s) collected from human patients were implanted in the dilated CBD as a virtual gallbladder (VGB), which was closed by suture ligation. This rat cholelithiasis model was examined by MRI, clinical observation, microcholangiography and histology. RESULTS: All rats survived two laparotomies. After ligation, the CBD was dilated to a stable size of 4 to 30 mm in diameter on day 21-28, which became a VGB. The rats initially showed signs of jaundice that diminished over time, which paralleled with the evolving TSB levels from 0.6 ± 0.3 mg/dL before ligation, through a peak of 10.9 ± 1.9 mg/dL on day 14, until a nearly normalized value after day 28. The dilated CBD with thickened wall allowed an incision for implantation of human gallstones of 1-10 mm in diameter. The rat cholelithiasis was proven by in vivo MRI and postmortem microcholangiography and histomorphology. CONCLUSION: A rat model cholelithiasis with human gallstones has been established, which proves feasible, safe, reliable, nontoxic and cost-effective. Given the gallstones of human origin, applications of this model may be of help in translational research such as optical detection and lysis of gallstones by systemic drug administration.
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Oxidative stress has a close relationship with various pathologic physiology phenomena and the potential biomarkers of oxidative stress may provide evidence for clinical diagnosis or disease prevention. Metabolomics was employed to identify the potential biomarkers of oxidative stress. High-performance liquid chromatography-diode array detector, mass spectrometry and partial least squares discriminate analysis were used in this study. The 10, 15 and 13 metabolites were considered to discriminate the model group, vitamin E-treated group and l-glutathione-treated group, respectively. Some of them have been identified, namely, malic acid, vitamin C, reduced glutathione and tryptophan. Identification of other potential biomarkers should be conducted and their physiological significance also needs to be elaborated.
Assuntos
Biomarcadores/análise , Metaboloma , Metabolômica/métodos , Estresse Oxidativo , Células Cultivadas , Cromatografia Líquida de Alta Pressão , Análise Discriminante , Glutationa/farmacologia , Humanos , Espectrometria de Massas , Metaboloma/efeitos dos fármacos , Vitamina E/farmacologiaRESUMO
OBJECTIVES: We sought to devise and test a multifunctional contrast dye agent for X-ray based digital radiography (DR) or computer tomography (CT), magnetic resonance imaging (MRI), and colored staining in ex vivo validation part of animal experiments. MATERIALS AND METHODS: The custom-formulated contrast dye namely red iodized oil (RIO) was prepared by solubilizing a lipophilic dye Oil Red O in iodized poppy seed oil (Lipiodol or LPD) followed by physicochemical characterizations. To explore and test the utility of RIO, normal rats (n = 10) and rabbits (n = 10) with myocardial infarction (MI) were euthanized by overdose of pentobarbital for infusion of RIO through catheterization. The bodies and/or excised organs including heart, liver, spleen, kidneys, pancreas, and intestines of the rats and rabbits were imaged at clinical mammography, CT and MRI units. These images were qualitatively studied and quantitatively analyzed using Wilcoxon Rank test with a P value < 0.05 being considered of a statistically significant difference. Imaging findings were verified by histomorphology. RESULTS: All experimental procedures were carried out successfully with the use of RIO. T1 and T2 relaxation time was 234.2 ± 2.6 ms and 141.9 ± 3.0 ms for RIO, close to that of native LPD. Proton ((1) H) NMR spectroscopy revealed almost identical profiles between RIO and native LPD. The clinical mammography unit, 128-slice CT scanner and 3.0T MRI magnet were well adapted for the animal experiments. Combined use of RIO with DR, MRI, CT and histology enabled microangiography of the organs, 3D visualization of rat pancreas, validation of in vivo cardiac quantification of MI and cause determination of the rabbit death after coronary occlusion. RIO appeared as red droplets and vacuoles in vessels by frozen and paraffin sections. Image analysis showed the superiority of DR images, which provided better overall image quality (4.35 ± 0.49) for all analyzed liver vessel segments. MRI images revealed moderate to good overall image quality ratings (3.45 ± 0.52). Comparing the signal intensities of vessel and liver with different MRI sequences, all P values were <0.01. CONCLUSIONS: RIO proved to be a multifunctional contrast dye, which could be applied as an imaging biomarker for tissue vascularity or blood perfusion, for visualization of organ anatomy and for ex vivo validation of in vivo animal experiments.
Assuntos
Meios de Contraste/administração & dosagem , Infarto do Miocárdio/diagnóstico por imagem , Animais , Meios de Contraste/química , Feminino , Humanos , Aumento da Imagem , Rim/diagnóstico por imagem , Fígado/diagnóstico por imagem , Imageamento por Ressonância Magnética , Masculino , Pâncreas/diagnóstico por imagem , Coelhos , Ratos , Ratos Sprague-Dawley , Baço/diagnóstico por imagem , Tomografia Computadorizada por Raios XRESUMO
Olea europaea oil is one of the most important part of the "Mediterranean dietary pattern", and a lot of epidemiological evidences showed that people with the Mediterranean diet having a lower morbidity of the cardiovascular system diseases, skin cancer and colon cancer. The health benefits of a Mediterranean diet not only attributed to monounsaturated fatty acids and vitamins and other nutrients in O. europaea oil, but also the phenolic compounds named as antioxidant effect. Studies have shown that O. europaea leaf contains much more antioxidant activity composition than the fruit, and oleuropein, flavonoids such polyphenols are the main active ingredients in O. europaea leaf. A small amount of O. europaea was introduced into China in 1956, after widely cultivated in Fujian, Guangdong, Taiwan, Sichuan, Shaanxi, Yunnan, and Longnan in Gansu province is the biggest O. europaea planting area in the country. In every winter pruning O. europaea will produce a large number of the leaves, which could be a high added value products (phenolic compounds) of rich source. This article through consulting the literature at home and abroad, classified and summarized the biological activity research status of O. europaea leaf extract and the possible mechanisms, including antimicrobial, antitumor, antioxidation, and on the function of brain, cardiovascular system, anti-diabetes, anti-inflammatory and analgesia and so on. At the same time looked ahead to its development prospects of O. europaea leaf extract, it has variety and high content of active ingredients, and antioxidant synergy, which provide a theoretical basis for the further development and utilization of O. europaea leaf. And O. europaea leaf extract has a rich cheap source and good bioavailability, which provided a broad space in the application of medical and health care.