413 research outputs found

    Metástase ocular como apresentação inicial de carcinoma de células renais: relato de dois casos

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    Authors report the cases of 2 patients who had an ocular lesion as the first sign leading to diagnosis of renal cell carcinoma, an uncommon presentation of this neoplasm. The first patient was a 59-year-old man presented with a mass in the right eye. The histological and immunohistochemical profile of the biopsy showed a probable renal cell carcinoma. A CT scan showed a solid mass in the left kidney. The patient underwent radical nephrectomy and excision of the ocular lesion and had an uneventful evolution. The second patient was a 72-year-old man presenting with an ulcerated lesion on the right inferior tarsal conjunctiva. An excisional biopsy of the lesion showed histological and immunohistochemical patterns of a clear cell carcinoma. Abdominal tomography disclosed a right peripheral renal tumor. A right radical nephrectomy was performed. Renal cell carcinoma may present atypically with metastases to quite uncommon organs. Nephrectomy may be of value in selected cases; the ocular metastases are usually excised for aesthetic and functional reasons.Os autores apresentam dois casos de metástase ocular como o primeiro sinal que levou ao diagnóstico de carcinoma renal, uma apresentação incomum desta neoplasia. O primeiro paciente era um homem de 59 anos com uma massa no olho direito. O perfil histológico e imunohistoquimico demonstraram um provável carcinoma de células renais. A tomografia computadorizada revelou uma massa sólida no rim esquerdo, e o paciente foi submetido a nefrectomia radical esquerda, apresentando uma evolução sem complicações. O segundo paciente era um homem com 72 anos portador de uma lesão ulcerada na conjuntiva tarsal inferior direita. Uma biopsia excisional da lesão demonstrou um padrão histológico e imunohistoquimico de carcinoma de células renais. A tomografia de abdômen demonstrou um tumor periférico em rim direito, sendo o paciente submetido a nefrectomia radical. O carcinoma de células renais pode se apresentar atipicamente com metástases para órgãos incomuns. Nefrectomia pode ser útil em casos selecionados. As metástases oculares geralmente são excisadas por razoes estéticas e funcionais

    Comparative Analysis of Double Stator Permanent Magnet Flux-Switching Machines with Segmented Inner Stator and Non-Segmented Inner Stator

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    This paper examines and compares the analysis of double stator PMFSM between segmented and non-segmented inner stator. The analysis particularly focused on output performance of flux linkage, back-EMF, cogging torque, average torque at various armature current densities, speed and power characteristics which are investigated using JMAGDesigner ver. 14.0. The aim of analysis is to overview the suitable design for future electric transportation based on the characteristic of double stator PMFSM. Thus, the 2D finite element analysis (FEA) approach is used for preliminary analysis. Based on flux linkage analysis, the segmented design generates higher magnetic flux magnitude which is 40% higher than the non-segmented design. Moreover, the segmented design also achieved higher torque and power compared to the nonsegmented design with 35.54% and 32.06% different percentage, respectively. The results obtained show that the segmented design produces better performance compared to non-segmented in terms of torque and power

    Role of the gp85/Trans-Sialidases in Trypanosoma cruzi Tissue Tropism: Preferential Binding of a Conserved Peptide Motif to the Vasculature in Vivo

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    Background: Transmitted by blood-sucking insects, the unicellular parasite Trypanosoma cruzi is the causative agent of Chagas' disease, a malady manifested in a variety of symptoms from heart disease to digestive and urinary tract dysfunctions. the reasons for such organ preference have been a matter of great interest in the field, particularly because the parasite can invade nearly every cell line and it can be found in most tissues following an infection. Among the molecular factors that contribute to virulence is a large multigene family of proteins known as gp85/trans-sialidase, which participates in cell attachment and invasion. But whether these proteins also contribute to tissue homing had not yet been investigated. Here, a combination of endothelial cell immortalization and phage display techniques has been used to investigate the role of gp85/trans-sialidase in binding to the vasculature.Methods: Bacteriophage expressing an important peptide motif (denominated FLY) common to all gp85/trans-sialidase proteins was used as a surrogate to investigate the interaction of this motif with the endothelium compartment. for that purpose phage particles were incubated with endothelial cells obtained from different organs or injected into mice intravenously and the number of phage particles bound to cells or tissues was determined. Binding of phages to intermediate filament proteins has also been studied.Findings and Conclusions: Our data indicate that FLY interacts with the endothelium in an organ-dependent manner with significantly higher avidity for the heart vasculature. Phage display results also show that FLY interaction with intermediate filament proteins is not limited to cytokeratin 18 (CK18), which may explain the wide variety of cells infected by the parasite. This is the first time that members of the intermediate filaments in general, constituted by a large group of ubiquitously expressed proteins, have been implicated in T. cruzi cell invasion and tissue homing.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Universidade Federal de São Paulo, Dept Microbiol Imunol & Parasitol, São Paulo, BrazilUniv São Paulo, Inst Quim, Dept Bioquim, BR-01498 São Paulo, BrazilUniv Texas MD Anderson Canc Ctr, David H Koch Ctr, Houston, TX 77030 USAUniv Texas MD Anderson Canc Ctr, Dept Canc Biol, Houston, TX 77030 USAUniversidade Federal de São Paulo, Dept Microbiol Imunol & Parasitol, São Paulo, BrazilFAPESP: 2004/03303-5FAPESP: 2008/54.806-8Web of Scienc

    A complex of α(6) integrin and E-cadherin drives liver metastasis of colorectal cancer cells through hepatic angiopoietin-like 6.

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    Homing of colorectal cancer (CRC) cells to the liver is a non-random process driven by a crosstalk between tumour cells and components of the host tissue. Here we report the isolation of a liver metastasis-specific peptide ligand (CGIYRLRSC) that binds a complex of E-cadherin and α(6) integrin on the surface of CRC cells. We identify angiopoietin-like 6 protein as a peptide-mimicked natural ligand enriched in hepatic blood vessels of CRC patients. We demonstrate that an interaction between hepatic angiopoietin-like 6 and tumoural α(6) integrin/E-cadherin drives liver homing and colonization by CRC cells, and that CGIYRLRSC inhibits liver metastasis through interference with this ligand/receptor system. Our results indicate a mechanism for metastasis whereby a soluble factor accumulated in normal vessels functions as a specific ligand for circulating cancer cells. Consistently, we show that high amounts of coexpressed α(6) integrin and E-cadherin in primary tumours represent a poor prognostic factor for patients with advanced CRC

    Retargeted adenoviruses for radiation-guided gene delivery

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    The combination of radiation with radiosensitizing gene delivery or oncolytic viruses promises to provide an advantage that could improve the therapeutic results for glioblastoma. X-rays can induce significant molecular changes in cancer cells. We isolated the GIRLRG peptide that binds to radiation-inducible 78 kDa glucose-regulated protein (GRP78), which is overexpressed on the plasma membranes of irradiated cancer cells and tumor-associated microvascular endothelial cells. The goal of our study was to improve tumor-specific adenovirus-mediated gene delivery by selectively targeting the adenovirus binding to this radiation-inducible protein. We employed an adenoviral fiber replacement approach to conduct a study of the targeting utility of GRP78-binding peptide. We have developed fiber-modified adenoviruses encoding the GRP78-binding peptide inserted into the fiber-fibritin. We have evaluated the reporter gene expression of fiber-modified adenoviruses in vitro using a panel of glioma cells and a human D54MG tumor xenograft model. The obtained results demonstrated that employment of the GRP78-binding peptide resulted in increased gene expression in irradiated tumors following infection with fiber-modified adenoviruses, compared with untreated tumor cells. These studies demonstrate the feasibility of adenoviral retargeting using the GRP78-binding peptide that selectively recognizes tumor cells responding to radiation treatment

    Ligand-targeted theranostic nanomedicines against cancer

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    AbstractNanomedicines have significant potential for cancer treatment. Although the majority of nanomedicines currently tested in clinical trials utilize simple, biocompatible liposome-based nanocarriers, their widespread use is limited by non-specificity and low target site concentration and thus, do not provide a substantial clinical advantage over conventional, systemic chemotherapy. In the past 20years, we have identified specific receptors expressed on the surfaces of tumor endothelial and perivascular cells, tumor cells, the extracellular matrix and stromal cells using combinatorial peptide libraries displayed on bacteriophage. These studies corroborate the notion that unique receptor proteins such as IL-11Rα, GRP78, EphA5, among others, are differentially overexpressed in tumors and present opportunities to deliver tumor-specific therapeutic drugs. By using peptides that bind to tumor-specific cell-surface receptors, therapeutic agents such as apoptotic peptides, suicide genes, imaging dyes or chemotherapeutics can be precisely and systemically delivered to reduce tumor growth in vivo, without harming healthy cells. Given the clinical applicability of peptide-based therapeutics, targeted delivery of nanocarriers loaded with therapeutic cargos seems plausible. We propose a modular design of a functionalized protocell in which a tumor-targeting moiety, such as a peptide or recombinant human antibody single chain variable fragment (scFv), is conjugated to a lipid bilayer surrounding a silica-based nanocarrier core containing a protected therapeutic cargo. The functionalized protocell can be tailored to a specific cancer subtype and treatment regimen by exchanging the tumor-targeting moiety and/or therapeutic cargo or used in combination to create unique, theranostic agents. In this review, we summarize the identification of tumor-specific receptors through combinatorial phage display technology and the use of antibody display selection to identify recombinant human scFvs against these tumor-specific receptors. We compare the characteristics of different types of simple and complex nanocarriers, and discuss potential types of therapeutic cargos and conjugation strategies. The modular design of functionalized protocells may improve the efficacy and safety of nanomedicines for future cancer therapy

    Peptide Ligands Incorporated into the Threefold Spike Capsid Domain to Re-Direct Gene Transduction of AAV8 and AAV9 In Vivo

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    Efficiency and specificity of viral vectors are vital issues in gene therapy. Insertion of peptide ligands into the adeno-associated viral (AAV) capsid at receptor binding sites can re-target AAV2-derived vectors to alternative cell types. Also, the use of serotypes AAV8 and -9 is more efficient than AAV2 for gene transfer to certain tissues in vivo. Consequently, re-targeting of these serotypes by ligand insertion could be a promising approach but has not been explored so far. Here, we generated AAV8 and -9 vectors displaying peptides in the threefold spike capsid domain. These peptides had been selected from peptide libraries displayed on capsids of AAV serotype 2 to optimize systemic gene delivery to murine lung tissue and to breast cancer tissue in PymT transgenic mice (PymT). Such peptide insertions at position 590 of the AAV8 capsid and position 589 of the AAV9 capsid changed the transduction properties of both serotypes. However, both peptides inserted in AAV8 did not result in the same changes of tissue tropism as they did in AAV2. While the AAV2 peptides selected on murine lung tissue did not alter tropism of serotypes 8 and -9, insertion of the AAV2-derived peptide selected on breast cancer tissue augmented tumor gene delivery in both serotypes. Further, this peptide mediated a strong but unspecific in vivo gene transfer for AAV8 and abrogated transduction of various control tissues for AAV9. Our findings indicate that peptide insertion into defined sites of AAV8 and -9 capsids can change and improve their efficiency and specificity compared to their wild type variants and to AAV2, making these insertion sites attractive for the generation of novel targeted vectors in these serotypes
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