Search results for "sarcoma"
showing 10 items of 566 documents
Biological tolerance of different materials in bulk and nanoparticulate form in a rat model: sarcoma development by nanoparticles
2006
In order to study the pathobiological impact of the nanometre-scale of materials, we evaluated the effects of five different materials as nanoparticulate biomaterials in comparison with bulk samples in contact with living tissues. Five groups out of 10 rats were implanted bilaterally for up to 12 months with materials of the same type, namely TiO 2 , SiO 2 , Ni, Co and polyvinyl chloride (PVC), subcutaneously with bulk material on one side of the vertebral column and intramuscularly with nanoparticulate material on the contralateral side. At the end of each implantation time, the site was macroscopically examined, followed by histological processing according to standard techniques. Malign…
Porous titania surfaces on titanium with hierarchical macro- and mesoporosities for enhancing cell adhesion, proliferation and mineralization
2014
Titanium received a macroporous titania surface layer by anodization, which contains open pores with average pore diameter around 5 μm. An additional mesoporous titania top layer following the contour of the macropores, of 100-200 nm thickness and with a pore diameter of 10nm, was formed by using the evaporation-induced self-assembly (EISA) method with titanium (IV) tetraethoxide as the precursor. A coherent laminar titania surface layer was thus obtained, creating a hierarchical macro- and mesoporous surface that was characterized by high-resolution electron microscopy. The interfacial bonding between the surface layers and the titanium matrix was characterized by the scratch test that con…
Pyrrolo[2,3-h]quinolinones: synthesis and photochemotherapic activity.
2003
A series of derivatives of the new ring system pyrrolo[2,3-h]quinoline-2-one was synthesized and evaluated as photoreagents toward cultured human tumor cells. Remarkable phototoxycity resulted for some derivatives, especially those bearing the phenyl group at the 7-position.
Isolated osteoblastoma of the cuboid bone: A case report and review of the literature
2020
Osteoblastoma is a relatively rare, benign, bone-forming tumor, commonly observed in the second and third decades of life. Spine and the long tubular bones are the most common sites of involvement. Osteoblastoma is infrequently seen in other sites, including the bones of hand and foot. A rare case of a 35-year-old man that presented an osteoblastoma of the cuboid bone is reported. The patient was treated with surgical resection and grafting. After the intervention, the patient recovered with no clinical and radiological evidence of recurrence after one year of follow-up. Several cases of osteoblastoma-like variant of osteosarcoma of the cuboid have been previously reported, but, to our know…
Pulmonary artery sarcoma mimicking chronic thromboembolic disease: computed tomography and magnetic resonance imaging findings.
1994
The diagnosis of the rare primary malignant tumors of the pulmonary arteries is often delayed as symptoms are nonspecific.Computed tomography (CT) and magnetic resonance imaging (MRI) of three patients with occlusion of the right pulmonary artery, two with sarcoma and one with chronic thromboembolic disease were analyzed for discriminating diagnostic criteria.Criteria suggesting pulmonary artery sarcoma are inhomogeneous high or low attenuation (hemorrhage, necrosis), soft-tissue density in pulmonary arteries, vascular distension, enhancement after administration of gadopentetate dimeglumine. Criteria for chronic thromboembolic disease are homogeneous soft-tissue lesions, abrupt vascular na…
pRb suppresses camptothecin-induced apoptosis in human osteosarcoma Saos-2 cells by inhibiting c-Jun N-terminal kinase
2001
AbstractThis paper studies the cytotoxic effect induced by the topoisomerase I inhibitor camptothecin in human osteosarcoma Saos-2 cells, which lack p53 and contain a non-functional form of the product of the retinoblastoma gene, pRb. Cytotoxicity induced by camptothecin was dose- and time-dependent; the treatment with 100 nM camptothecin reduced cell viability by 50% at 32 h and by 75% at 72 h of exposure. The cytotoxic effect was caused by apoptosis, as ascertained by morphological evidence, acridine orange-ethidium bromide staining and flow cytometric analysis. Apoptosis was accompanied by both the activation of caspase-3 and the fragmentation of poly(ADP-ribose) polymerase. Treatment wi…
Let-7d miRNA Shows Both Antioncogenic and Oncogenic Functions in Osteosarcoma-Derived 3AB-OS Cancer Stem Cells
2015
Osteosarcoma (OS), an aggressive highly invasive and metastatic bone-malignancy, shows therapy resistance and recurrence, two features that likely depend on cancer stem cells (CSCs), which hold both self-renewing and malignant potential. So, effective anticancer therapies against OS should specifically target and destroy CSCs. We previously found that the let-7d microRNA was downregulated in the 3AB-OS-CSCs, derived from the human OS-MG63 cells. Here, we aimed to assess whether let-7d modulation affected tumorigenic and stemness properties of these OS-CSCs. We found that let-7d-overexpression reduced cell proliferation by decreasing CCND2 and E2F2 cell-cycle-activators and increasing p21 an…
Induction of apoptosis in human osteosarcoma Saos-2 cells by the proteasome inhibitor MG132 and the protective effect of pRb
2003
Induction of apoptosis in human osteosarcoma Saos-2 cells by the proteasome inhibitor MG132 and the protective effect of pRb
Insights of Tris(2-pyridylmethyl)amine as anti-tumor agent for osteosarcoma: experimental and in silico studies
2021
Abstract Osteosarcoma (OS) is a malignant bone tumor and its occurrence is associated with high levels of microRNAs (miRNAs) and critical protein sinvolved on intracellular signaling pathways. Cisplatin and Doxorubicin are employed on chemotherapy, but their use cause side effects and contributes to multidrug resistance. Since several tripodal amines have been studied as anticancer agents, tris(2-pyridylmethyl)amine (TPA) was investigated against osteosarcoma cells. Here we show that TPA exhibits activity against MG-63 and Saos-2 cells. Cyclic voltammetry results indicate an interaction between TPA and dsDNA, denoted by blocking of the proton-assisted reduction of the 2-pyridylmethyl moiety…
Evidence for and Against Hypoxia as the Primary Cause of Tumor Aggressiveness
2003
In clinical trials, tumor hypoxia has consistently been associated with tumor aggressiveness. The evidence for an association between hypoxia and metastasis and more rapid tumor progression and death is seen in uterine cervical cancer, and sarcoma of soft tissue. Evidence is building in prostate, vulva, head and neck, and breast cancers. A major question is whether hypoxia precedes tumor aggressiveness or whether aggressive tumors incidentally are also hypoxic.