969 resultados para Small round cell tumor


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We have used a combination of computerized database mining and experimental expression analyses to identify a gene that is preferentially expressed in normal male and female reproductive tissues, prostate, testis, fallopian tube, uterus, and placenta, as well as in prostate cancer, testicular cancer, and uterine cancer. This gene is located on the human X chromosome, and it is homologous to a family of genes encoding GAGE-like proteins. GAGE proteins are expressed in a variety of tumors and in testis. We designate the novel gene PAGE-1 because the expression pattern in the Cancer Genome Anatomy Project libraries indicates that it is predominantly expressed in normal and neoplastic prostate. Further database analysis indicates the presence of other genes with high homology to PAGE-1, which were found in cDNA libraries derived from testis, pooled libraries (with testis), and in a germ cell tumor library. The expression of PAGE-1 in normal and malignant prostate, testicular, and uterine tissues makes it a possible target for the diagnosis and possibly for the vaccine-based therapy of neoplasms of prostate, testis, and uterus.

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We have developed a modified rhodamine (Rho) staining procedure to study uptake and efflux in murine hematopoietic stem cells. Distinct populations of Rho++ (bright), Rho+ (dull), and Rho- (negative) cells could be discriminated. Sorted Rho- cells were subjected to a second Rho staining procedure with the P-glycoprotein blocking agent verapamil (VP). Most cells became Rho positive [Rho-/Rho(VP)+ cells] and some remained Rho negative [Rho-/Rho(VP)- cells]. These cell fractions were characterized by their marrow-repopulating ability in a syngeneic, sex-mismatch transplantation model. Short-term repopulating ability was determined by recipient survival for at least 6 weeks after lethal irradiation and transplantation--i.e., radioprotection. Long-term repopulating ability at 6 months after transplantation was measured by fluorescence in situ hybridization with a Y-chromosome-specific probe, by graft function and recipient survival. Marrow-repopulating cells were mainly present in the small Rho- cell fraction. Transplantation of 30 Rho- cells resulted in 50% radioprotection and > 80% donor repopulation in marrow, spleen, and thymus 6 months after transplantation. Cotransplantation of cells from both fractions in individual mice directly showed that within this Rho- cell fraction, the Rho-/Rho(VP)+ cells exhibited mainly short-term and the Rho-/Rho(VP)- cells exhibited mainly long-term repopulating ability. Our results indicate that hematopoietic stem cells have relatively high P-glycoprotein expression and that the cells responsible for long-term repopulating ability can be separated from cells exhibiting short-term repopulating ability, probably by a reduced mitochondrial Rho-binding capacity.

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Trabalho Final do Curso de Mestrado Integrado em Medicina, Faculdade de Medicina, Universidade de Lisboa, 2014

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There are very few data on trichodinids of freshwater fishes in Australia. 2003 fishes were surveyed across Eastern Australia to investigate the diversity of trichodinids present, to determine which species have been introduced with exotic fishes and to determine the extent to which these species have crossed into native fish Populations. Twenty-one putative trichodinid species were recovered from the 33 fish species examined. Trichodina heterodentata, T. mutabilis and T. reticulata were the exotic species recovered regularly; a single specimen matched a fourth exotic species, T acuta. All four exotic species are redescribed from Australian material. Trichodina heterodentata was recorded from 17 species of fishes, 15 of which were new host records; this species is identified as one of emerging importance in fish parasitology and a list of its known hosts is presented. Two new native species are also described based on silver stained specimens: T cribbi sp. n. from Hypseleotris galii, H. klunzingeri, and Hypseleotris sp. 5; and T. bassonae sp. n. from Selenotoca multifasciata. Trichodina cribbi is characterised by a large circular central inclusion and approximately 28 denticles, which have a blade length slightly greater than the ray length. Trichodina bassonae is characterised by a small, round, central inclusion and approximately 25 denticles, which have straight, non tapering rays that are in line with the leading edge of the denticle blade. It is estimated that the Australian trichodinid fauna may include up to 150 as yet undescribed species and represents a major source of unexplored biodiversity.

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Loss of skeletal muscle is an important determinant of survival in patients with cancer-induced weight loss. The effect of the leucine metabolite beta-hydroxy-beta-methylbutyrate (HMB) on the reduction of body weight loss and protein degradation in the MAC16 model of cancer-induced weight loss has been compared with that of eicosapentaenoic acid (EPA), a recognized inhibitor of protein degradation. HMB was found to attenuate the development of weight loss at a dose greater than 0.125 g/kg accompanied by a small reduction in tumor growth rate. When EPA was used at a suboptimal dose level (0.6 g/kg) the combination with HMB seemed to enhance the anticachectic effect. Both treatments caused an increase in the wet weight of soleus muscle and a reduction in protein degradation, although there did not seem to be a synergistic effect of the combination. Proteasome activity, determined by the "chymotrypsin-like" enzyme activity, was attenuated by both HMB and EPA. Protein expression of the 20S alpha or beta subunits was reduced by at least 50%, as were the ATPase subunits MSS1 and p42 of the 19S proteasome regulatory subunit. This was accompanied by a reduction in the expression of E2(14k) ubiquitin-conjugating enzyme. The combination of EPA and HMB was at least as effective or more effective than either treatment alone. Attenuation of proteasome expression was reflected as a reduction in protein degradation in gastrocnemius muscle of cachectic mice treated with HMB. In addition, HMB produced a significant stimulation of protein synthesis in skeletal muscle. These results suggest that HMB preserves lean body mass and attenuates protein degradation through down-regulation of the increased expression of key regulatory components of the ubiquitin-proteasome proteolytic pathway, together with stimulation of protein synthesis.

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The Solid Oxide Fuel Cell (SOFC) is a class of fuel cells that is capable of generating very high levels of power at high temperatures. SOFCs are used for stationary power generation and as Combined Heat and Power (CHP) systems. In spite of all the beneficial features of the SOFC, the propagation of ripple currents, due to nonlinear loads, is a challenging problem, as it interferes with the physical operation of the fuel cell. The purpose of this thesis is to identify the cause of ripples and attempt to eliminate or reduce the ripple propagation through the use of Active Power Filters (APF). To this end, a systematic approach to modeling the fuel cell to account for its nonlinear behavior in the presence of current ripples is presented. A model of a small fuel cell power system which consists of a fuel cell, a DC-DC converter, a single-phase inverter and a nonlinear load is developed in MATLAB/Simulink environment. The extent of ripple propagation, due to variations in load magnitude and frequency, are identified using frequency spectrum analysis. In order to reduce the effects of ripple propagation, an APF is modeled to remove ripples from the DC fuel cell current. The emphasis of this thesis is based on the idea that small fuel cell systems cannot implement large passive filters to cancel the effects of ripple propagation and hence, the compact APF topology effectively protects the fuel cell from propagating ripples and improves its electrical performance.

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We performed an immunogenetic analysis of 345 IGHV-IGHD-IGHJ rearrangements from 337 cases with primary splenic small B-cell lymphomas of marginal-zone origin. Three immunoglobulin (IG) heavy variable (IGHV) genes accounted for 45.8% of the cases (IGHV1-2, 24.9%; IGHV4-34, 12.8%; IGHV3-23, 8.1%). Particularly for the IGHV1-2 gene, strong biases were evident regarding utilization of different alleles, with 79/86 rearrangements (92%) using allele (*)04. Among cases more stringently classified as splenic marginal-zone lymphoma (SMZL) thanks to the availability of splenic histopathological specimens, the frequency of IGHV1-2(*)04 peaked at 31%. The IGHV1-2(*)04 rearrangements carried significantly longer complementarity-determining region-3 (CDR3) than all other cases and showed biased IGHD gene usage, leading to CDR3s with common motifs. The great majority of analyzed rearrangements (299/345, 86.7%) carried IGHV genes with some impact of somatic hypermutation, from minimal to pronounced. Noticeably, 75/79 (95%) IGHV1-2(*)04 rearrangements were mutated; however, they mostly (56/75 cases; 74.6%) carried few mutations (97-99.9% germline identity) of conservative nature and restricted distribution. These distinctive features of the IG receptors indicate selection by (super)antigenic element(s) in the pathogenesis of SMZL. Furthermore, they raise the possibility that certain SMZL subtypes could derive from progenitor populations adapted to particular antigenic challenges through selection of VH domain specificities, in particular the IGHV1-2(*)04 allele.

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Giant cell-rich osteolytic lesions may have overlapping clinical, radiologic, and histopathologic features, with an important degree of difficulty of diagnosis and treatment. We report a case of double osteolytic lesion at the middle-finger in a young man without previous history of hand trauma. He underwent en-bloc resection of the bone lesions and reconstruction by graft of hydroxyapatite, resulting in a good morpho-functional result. Histological diagnosis was giant cell reparative granuloma (GCRG), although several features were considered atypical, including the appearance of the giant cells and the areas of the stroma that more closely resembled a giant cell tumor. GCRG is a benign rare intraosseous lesion and the true nature is controversial and unknown. The theories are that it could be a reactive lesion, a developmental anomaly or a benign neoplasm. It appears as an osteolytic lesion that must be considered in the differential diagnosis of other “critical” bone lesions similar in clinical, as well as radiologic and pathological appearance. Further characterization studies are helpful and necessary for the proper management.

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BACKGROUND: Alterations in glucose metabolism and epithelial-mesenchymal transition (EMT) constitute two important characteristics of carcinoma progression toward invasive cancer. Despite an extensive characterization of each of them separately, the links between EMT and glucose metabolism of tumor cells remain elusive. Here we show that the neuronal glucose transporter GLUT3 contributes to glucose uptake and proliferation of lung tumor cells that have undergone an EMT. RESULTS: Using a panel of human non-small cell lung cancer (NSCLC) cell lines, we demonstrate that GLUT3 is strongly expressed in mesenchymal, but not epithelial cells, a finding corroborated in hepatoma cells. Furthermore, we identify that ZEB1 binds to the GLUT3 gene to activate transcription. Importantly, inhibiting GLUT3 expression reduces glucose import and the proliferation of mesenchymal lung tumor cells, whereas ectopic expression in epithelial cells sustains proliferation in low glucose. Using a large microarray data collection of human NSCLCs, we determine that GLUT3 expression correlates with EMT markers and is prognostic of poor overall survival. CONCLUSIONS: Altogether, our results reveal that GLUT3 is a transcriptional target of ZEB1 and that this glucose transporter plays an important role in lung cancer, when tumor cells loose their epithelial characteristics to become more invasive. Moreover, these findings emphasize the development of GLUT3 inhibitory drugs as a targeted therapy for the treatment of patients with poorly differentiated tumors.

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The phosphoinositide 3-kinase (PI3K) pathway is fundamental for cell proliferation and survival and is frequently altered and activated in neoplasia, including carcinomas of the lung. In this study, we investigated the potential of targeting the catalytic class I(A) PI3K isoforms in small cell lung cancer (SCLC), which is the most aggressive of all lung cancer types.

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The cytokine tumor-necrosis factor-related apoptosis-inducing ligand (Apo2L/TRAIL) has been shown to preferentially induce apoptosis in cancer cells. A previous study of our group demonstrated that non-small cell lung cancer cell lines can be sensitized to Apo2L/TRAIL-induced apoptosis by chemotherapeutic agents. The aim of the present study was the evaluation of these results in a model of primary culture of non-small cell lung cancer.

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The FUS1 tumor suppressor gene (TSG) has been found to be deficient in many human non-small cell lung cancer (NSCLC) tissue samples and cell lines (1,2,3). Studies have shown potent anti-tumor activity of FUS1 in animal models where FUS1 was delivered through a liposomal vector (4) and the use of FUS1 as a therapeutic agent is currently being studied in clinical human trials (5). Currently, the mechanisms of FUS1 activity are being investigated and my studies have shown that c-Abl tyrosine kinase is inhibited by the FUS1 TSG.^ Considering that many NSCLC cell lines are FUS1 deficient, my studies further identified that FUS1 deficient NSCLC cells have an activated c-Abl tyrosine kinase. C-Abl is a known proto-oncogene and while c-Abl kinase is tightly regulated in normal cells, constitutively active Abl kinase is known to contribute to the oncogenic phenotype in some types of hematopoietic cancers. My studies show that the active c-Abl kinase contributes to the oncogenicity of NSCLC cells, particularly in tumors that are deficient in FUS1, and that c-Abl may prove to be a viable target in NSCLC therapy.^ Current studies have shown that growth factor receptors play a role in NSCLC. Over-expression of the epidermal growth factor receptor (EGFR) plays a significant role in aggressiveness of NSCLC. Current late stage treatments include EFGR tyrosine kinase inhibitors or EGFR antibodies. Platelet-derived growth factor receptor (PDGFR) also has been shown to play a role in NSCLC. Of note, both growth factor receptors are known upstream activators of c-Abl kinase. My studies indicate that growth factor receptor simulation along deficiency in FUS1 expression contributes to the activation of c-Abl kinase in NSCLC cells. ^

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Construction of a bispecific single-chain antibody derivative is described that consists of two different single-chain Fv fragments joined through a Gly-Ser linker. One specificity of the two Fv fragments is directed against the CD3 antigen of human T cells and the other is directed against the epithelial 17-1A antigen; the latter had been found in a clinical trial to be a suitable target for antibody therapy of minimal residual colorectal cancer. The construct could be expressed in CHO cells as a fully functional protein, while its periplasmic expression in Escherichia coli resulted in a nonfunctional protein only. The antigen-binding properties of the bispecific single-chain antibody are indistinguishable from those of the corresponding univalent single-chain Fv fragments. By redirecting human peripheral T lymphocytes against 17-1A-positive tumor cells, the bispecific antibody proved to be highly cytotoxic at nanomolar concentrations as demonstrated by 51Cr release assay on various cell lines. The described bispecific construct has a molecular mass of 60 kDa and can be easily purified by its C-terminal histidine tail on a Ni-NTA chromatography column. As bispecific antibodies have already been shown to be effective in vivo in experimental tumor systems as well as in phase-one clinical trials, the small CD3/17-1A-bispecific antibody may be more efficacious than intact antibodies against minimal residual cancer cells.

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Background: Tumor volume has been shown to be a prognostic factor for the response of some tumors to radiotherapy. TNM stage has prognostic value for patients treated surgically for non-small cell lung cancer (NSCLC), but its value is less clear for patients treated by nonsurgical means. This may be because tumor size is not a consistent determinant of T stage or stage group. As part of the preliminary analyses for the Trans-Tasman Radiation Oncology Group 99-05 study, the authors performed this analysis to determine to what extent stage reflects tumor volume. Methods: In this prospective multicenter observational study, patients had to have histologically proven NSCLC, no evidence of disease beyond the primary site or thoracic lymph nodes, and been planned for radical radiotherapy with or without chemotherapy. Tumor volume measurements were based on computed tomography-based treatment planning images. Results: Four hundred four patients were available for analysis. There was a strong correlation between (log) maximum tumor diameter and (log) tumor volume (r = 0.93, p < 0.001). Although there was a highly significant trend of increasing volume with increasing T stage and stage group, when tumors were categorized into four groups according to increasing volume, there was only 55% concordance with T stage and 67% concordance with stage group. Conclusions: There is limited correlation between tumor size and disease stage in patients with NSCLC. This justifies documentation and investigation of size as a potential prognostic factor independent of stage. Maximum tumor diameter may be an adequate substitute for volume as a measurement of size.