990 resultados para Malignant obstruction


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Malignant pleural mesothelioma (MPM) is increasingly observed in industrial countries. Despite concerted efforts and combined treatments including surgery, chemotherapy and irradiation patients eventually succumb from relentless local progression of the disease. Recent publications have demonstrated an improved response rate with the cytostatic agent pemetrexed which will be tested in a neoadjuvant setting followed by surgery. However, effective tumor control requires new loco-regional treatment modalities, eventually in combination with neoadjuvant chemotherapy. Intraoperative photodynamic therapy (PDT) of the chest cavity has been proposed as an attractive treatment concept for MPM since a selective treatment of the tumor bed following resection has the potential to improve local tumor control. It has been shown to afford tumor destruction in patients with mesothelioma but efficiency and selectivity is not yet sufficient for routine clinical application. Experimental work on MPM has shown that tumor selectivity of PDT depend on treatment conditions and can be improved by structural modification and improved targeting of the sensitizers. Refinements of PDT for mesothelioma will depend on a more detailed understanding of the pathways for preferential sensitizer accumulation within the tumor as well as on synergistic effects between PDT and chemotherapeutic agents.

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Résumé: Le neuroblastome (NB) est un néoplasme dévastateur de la petite enfance, pour lequel il n'existe pas encore de traitement efficace. Les chimiokines et leurs récepteurs ont été impliqués dans la croissance des tumeurs et la formation de métastases, et en particulier, il a été rapporté que l'axe CXCR4/CXCL12 dirigeait le guidage, ainsi que l'invasion des cellules cancéreuses vers des organes spécifiques. Notre étude avait pour objectif d'analyser le rôle de CxCR4 exogène dans le comportement malin du NB, en étudiant la croissance des cellules tumorales, leur capacité de survie, de migration et d'invasion in vitro et en validant ces résultats grâce à un modèle orthotopique murin de la progression tumorale du NB in vivo. La surexpression de CXCR4 dans les cellules faiblement métastatiques IGR-NB8 n'exprimant pas CXCR4, a augmenté la mobilité des cellules vers CXCL12 in vitro. De plus, les cellules surexprimant CXCR4 ont été moins affectées par la privation de sérum que les cellules contrôles. Le volume des tumeurs chez les animaux greffés de manière orthotopique avec les cellules NB8-CXCR4-C3 était significativement plus élevé que celui des tumeurs issues des cellules contrôles NB8-E6 au moment du sacrifice des animaux. Cependant, aucune induction des métastases n'a été observée. La lignée cellulaire IGR-N91, aux propriétés invasives et métastatiques in vivo, exprime constitutivement des quantités modérées de CXCR4. La surexpression du récepteur dans cette lignée a accéléré la croissance tumorale in vivo, mais n'a pas augmenté pas l'occurrence des métastases. Les cellules IGR-N91, dans lesquelles l'expression de CXCR4 a été éteinte, suite à l'introduction de shRNA stable contre CXCR4, a présenté une croissance cellulaire plus lente, in vitro et in vivo. Afin d'identifier les gènes et les voies de signalisation impliqués dans les effets dépendants de CXCR4-CXCL12 dans le NB, des analyses du profil d'expression des gènes ont été effectuées sur les lignées cellulaires transfectées ou non (contrôle). Trois clones contrôles ont été comparés à 3 clones surexprimant CXCR4 pour chacune des lignées (IGR-NB8 et IGR-N91). Les analyses biostatiques ont identifié 10 gènes induits, dont CXCR4, et 31 gènes réprimés, communs entre tous les clones surexprimant CXCR4. Ces observations démontrent que la surexpression de CXCR4 dans le NB stimule la croissance, la survie et la migration chémotactique des cellules tumorales, mais est insuffisante pour induire ou augmenter leurs capacités invasives et métastatiques. Les voies de signalisation activées suite à la surexpression de CXCR4 et identifiées à travers le profil global de l'expression des gènes pourraient être des cibles intéressantes pour le développement de drogues capables d'inhiber la croissance tumorale. Abstact: Neuroblastoma (NB) is a devastating childhood neoplasm for which there is not yet an efficient treatment. Chemokines and their receptors have been involved in tumour growth and metastasis, and in particular the CXCR4/CXCL12 axis has been reported to mediate organ-specific cancer cells homing and invasion. The purpose of the study was to investigate the role of ectopic CXCR4 in the malignant behaviour of NB by studying tumour cell growth, survival, migration, and invasion in vitro and by validating these results using a murine orthotopic model of NB tumour progression in vivo. CXCR4 overexpression in the low metastatic, CXCR4-negative IGR-NB8 cells resulted in CXCL12-mediated chemotaxis in vitro. Furthermore, CXCR4 overexpressing cells were less affected by serum deprivation than mock-transduced cells. In vivo studies revealed that, at sacrifice, volumes of tumours developing in mice with orthotopically implanted NB8-CXCR4-C3 cells, were significantly increased compared to NB8-E6 control tumours. However, no induction of metastases was observed. The in vivo invasive and metastatic cell line IGR-N91 cell line constitutively expresses moderate levels of CXCR4. Overexpression of CXCR4 enhanced in vivo tumour growth but did not increase the occurrence of metastases. IGR-N91 cells where CXCR4 has been knocked-down by stable shRNA grew slower in vitro and in vivo. To identify genes and pathways involved in the CXCR4/CXCL12-mediated effects in NB expression, profiles analyses (Affymetrix) were performed on transduced and control cell lines. Three mock-transduced clones were compared to three CXCR4 overexpressing clones of either cell line IGR-NB8 and IGR-N91. Biostatistical analysis identified 10 commonly upregulated genes (including CXCR4) and 31 downregulated genes common to all CXCR4 overexpressing clones. These observations demonstrate that overexpression of CXCR4 in NB stimulates tumour cell growth, survival, and chemotactic migration but is not sufficient to induce or enhance invasive and metastatic capacities. Activated pathways upon CXCR4 overexpression, identified through global gene expression profiling may be interesting targets for drugs inhibiting tumour growth.

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PURPOSE: To report the lethal course of malignant transformation of retinoma in an adult. METHODS: Case report. A 40-year-old patient presented with retinoma in his right eye and retinoblastoma in his left eye. Enucleation was recommended but refused and the patient received whole eye radiotherapy elsewhere. Five years later he presented again, with temporal hemianopsia of the left eye secondary to chiasmatic invasion. RESULTS: Diagnosis of retinoblastoma infiltration was confirmed by stereotactic biopsy of the chiasmatic lesion. Treatment with intravenous and intrathecal chemotherapy led to partial remission, and was followed by stereotactic irradiation of the chiasmatic mass and right optic nerve. The left eye was enucleated. Death occurred one year later due to cerebrospinal fluid metastases. CONCLUSION: Extraocular extension of retinoblastoma diagnosed in adulthood has never, to our knowledge, been reported. This case stresses the importance of lifelong retinoma monitoring and the necessity for radical treatment in the event of malignant transformation.

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BACKGROUND: Targeted delivery of anticancer chemotherapeutics such as mitoxantrone (MTX) can significantly intensify their cytotoxic effects selectively in solid tumors such as breast cancer. In the current study, folic acid (FA)-armed and MTX-conjugated magnetic nanoparticles (MNPs) were engineered for targeted eradication of folate receptor (FR)-positive cancerous cells. Polyethylene glycol (PEG), FA and MTX were covalently conjugated onto the MNPs to engineer the PEGylated FA-MTX-MNPs. The internalization studies were performed using fluorescein isothiocyanate (FITC)-labeled FA-decorated MNPs (FA-FITC-MNPs) in both FR-positive MCF-7 cells and FR-negative A549 cells by means of fluorescence microscopy and flow cytometry. The cellular and molecular impacts of FA-MTX-MNPs were examined using trypan blue cell viability and FITC-labeled annexin V apoptosis assays and 4',6-diamidino-2-phenylindole (DAPI) staining, DNA ladder and quantitative polymerase chain reaction (qPCR) assays. RESULTS: The FR-positive MCF-7 cells showed significant internalization of the FA-FITC-MNPs, but not the FR-negative A549 cells. The FR-positive cells treated with the PEGylated FA-MTX-MNPs exhibited the IC50 values of 3 μg/mL and 1.7 μg/mL, 24 h and 48 h post-treatment, respectively. DAPI staining and DNA ladder assays revealed significant condensation of nucleus and fragmentation of genomic DNA in the FR-positive MCF-7 cells treated with the PEGylated FA-MTX-MNPs as compared to the FR-negative A549 cells. The FITC-labeled annexin V assay confirmed emergence of late apoptosis (>80%) in the FR-positive MCF-7 cells treated with the PEGylated FA-MTX-MNPs, but not in the FR-negative A549 cells. The qPCR analysis confirmed profound cytotoxic impacts via alterations of apoptosis-related genes induced by MTX-FA-MNPs in MCF-7 cells, but not in the A549 cells. CONCLUSION: Our findings evince that the engineered PEGylated FA-MTX-MNPs can be specifically taken up by the FR-positive malignant cells and effectively demolish them through up-regulation of Bcl-2-associated X protein (Bax) and Caspase 9 and down-regulation of AKt. Hence, the engineered nanosystem is proposed for simultaneous targeted imaging and therapy of various cancers overexpressing FRs.

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Venous cannula orifice obstruction is an underestimated problem during augmented cardiopulmonary bypass (CPB), which can potentially be reduced with redesigned, virtually wall-less cannula designs versus traditional percutaneous control venous cannulas. A bench model, allowing for simulation of the vena cava with various affluent orifices, venous collapse and a worst case scenario with regard to cannula position, was developed. Flow (Q) was measured sequentially for right atrial + hepatic + renal + iliac drainage scenarios, using a centrifugal pump and an experimental bench set-up (afterload 60 mmHg). At 1500, 2000 and 2500 RPM and atrial position, the Q values were 3.4, 6.03 and 8.01 versus 0.77*, 0.43* and 0.58* l/min: p<0.05* for wall-less and the Biomedicus(®) cannula, respectively. The corresponding pressure values were -15.18, -31.62 and -74.53 versus -46.0*, -119.94* and -228.13* mmHg. At the hepatic position, the Q values were 3.34, 6.67 and 9.26 versus 2.3*, 0.42* and 0.18* l/min; and the pressure values were -10.32, -20.25 and -42.83 versus -23.35*, -119.09* and -239.38* mmHg. At the renal position, the Q values were 3.43, 6.56 and 8.64 versus 2.48*, 0.41* and 0.22* l/min and the pressure values were -9.64, -20.98 and -63.41 versus -20.87 -127.68* and -239* mmHg, respectively. At the iliac position, the Q values were 3.43, 6.01 and 9.25 versus 1.62*, 0.55* and 0.58* l/min; the pressure values were -9.36, -33.57 and -44.18 versus -30.6*, -120.27* and -228* mmHg, respectivly. Our experimental evaluation demonstrates that the redesigned, virtually wall-less cannulas, allowing for direct venous drainage at practically all intra-venous orifices, outperform the commercially available control cannula, with superior flow at reduced suction levels for all scenarios tested.

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Solitary fibrous tumors are rare neoplasms of mesenchymal origin that have been reported in various other extrathoracic sites, including the liver. We present a case series of three malignant solitary fibrous tumors of the liver, occurring in two women 74 and 80 years old and one 65-year-old man. No clinical features were predictive of malignancy except the large sizes and synchronous presence of lung metastases in two of the three cases. Histological examinations revealed the presence of high pleomorphic cellularity with nuclear atypia, necrosis and high mitotic ratios. All patients died of disease progression.

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Background: Malignant hypertension is defined by marked systemic arterial hypertension with retinal haemorrhages, exudation or papilloedema. Due to the rarity of this disease and due to its non-specific symptoms and lesions, the diagnosis can be challenging. Patients and Methods We investigated the types of symptoms and ocular lesions observed with ocular fundus examination, ocular fundus photography, fluorescein angiography and optical coherence tomography in a small case series of 7 patients with malignant hypertension. Results: Median systolic blood pressure (BP) was 205 mmHg ± 21. Median diastolic BP was 150 mmHg ± 16. Decrease in visual acuity (6/7 patients) and scotoma (5/7) were the main symptoms and Elschnig spot, flamed shaped haemorrhage, serous retinal detachment, cotton wool spots and optic nerve oedema were the five most frequently observed lesions. A regression of lesions was observed after therapy of systemic hypertension. Conclusion: The association of multiple lesions strongly suggests malignant hypertension. However even in cases with only one lesion malignant hypertension should be kept in mind.

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OBJECTIVES: Management of malignant pericardial effusion (PE) is complex. Cardiac surgeons are not necessarily familiar with or are challenged by the many underlying etiologies. Analyzing risk factors for mortality may help to estimate the benefit of surgery in high-risk patients. METHODS: Patients undergoing a surgical pericardiotomy for malignant PE, between 2001 and 2011, were included. The influence of tumor type, disease extension, intra-pericardial tumor infiltration on early mortality and long-term survival as well as freedom from symptoms after drainage, and the use of sclerosing agents on PE recurrence rates was analyzed. RESULTS: PE drainage was performed on 46 patients 12 ± 30 months after tumor diagnosis. Malignant diseases were lung cancers (50 %), breast cancers (15 %), lymphoma and leukemia (13 %), cancers of the digestive tract (13 %), and others (9 %). 80 % of patients were symptomatic and symptom relief was achieved in 65 %. Nobody died during surgery. Recurrence rate was 4 %. Early in-hospital mortality was 22 %. After 1 year, 29 % of patients were alive. Eleven patients (24 %) had a complete tumor regression. Metastatic spread (p < 0.001), pericardial infiltration (p = 0.02), and intra-pericardial Bleomycin (p = 0.01) injection were associated with increased mortality. Hematological malignancies had a better prognosis for survival. CONCLUSION: Surgical pericardiotomy is safe, associated with a low recurrence rate and symptom relief in the majority of dyspneic patients. Intra-pericardial Bleomycin may reduce recurrent effusion but does not ameliorate survival. Long-term survival rate was low with an increased mortality in cases of metastatic spreading, pericardial infiltration, and as the tumor of origin: breast cancers. Leukemic and lymphatic tumors have better prognosis.