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1.
Sci Rep ; 14(1): 1448, 2024 01 16.
Artigo em Inglês | MEDLINE | ID: mdl-38228854

RESUMO

Breast cancer is a significant global health burden, causing a substantial number of deaths. Systemic metastatic tumour cell dissemination is a major cause of poor outcomes. Understanding the mechanisms underlying metastasis is crucial for effective interventions. Changes in the extracellular matrix play a pivotal role in breast cancer metastasis. In this work, we present an advanced multimodal X-ray computed tomography, by combining Small-angle X-ray Scattering Tensor Tomography (SAXS-TT) and X-ray Fluorescence Computed Tomography (XRF-CT). This approach likely brings out valuable information about the breast cancer metastasis cascade. Initial results from its application on a breast cancer specimen reveal the collective influence of key molecules in the metastatic mechanism, identifying a strong correlation between zinc accumulation (associated with matrix metalloproteinases MMPs) and highly oriented collagen. MMPs trigger collagen alignment, facilitating breast cancer cell intravasation, while iron accumulation, linked to angiogenesis and vascular endothelial growth factor VEGF, supports cell proliferation and metastasis. Therefore, these findings highlight the potential of the advanced multimodal X-ray computed tomography approach and pave the way for in-depth investigation of breast cancer metastasis, which may guide the development of novel therapeutic approaches and enable personalised treatment strategies, ultimately improving patient outcomes in breast cancer management.


Assuntos
Neoplasias da Mama , Melanoma , Neoplasias Cutâneas , Humanos , Feminino , Neoplasias da Mama/patologia , Fator A de Crescimento do Endotélio Vascular , Raios X , Espalhamento a Baixo Ângulo , Difração de Raios X , Metaloproteinases da Matriz/metabolismo , Colágeno , Metástase Neoplásica
3.
Brain ; 146(6): 2346-2363, 2023 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-36511898

RESUMO

Polyglutamine diseases are a group of neurodegenerative disorders caused by an abnormal expansion of CAG repeat tracts in the codifying regions of nine, otherwise unrelated, genes. While the protein products of these genes are suggested to play diverse cellular roles, the pathogenic mutant proteins bearing an expanded polyglutamine sequence share a tendency to self-assemble, aggregate and engage in abnormal molecular interactions. Understanding the shared paths that link polyglutamine protein expansion to the nervous system dysfunction and the degeneration that takes place in these disorders is instrumental to the identification of targets for therapeutic intervention. Among polyglutamine diseases, spinocerebellar ataxias (SCAs) share many common aspects, including the fact that they involve dysfunction of the cerebellum, resulting in ataxia. Our work aimed at exploring a putative new therapeutic target for the two forms of SCA with higher worldwide prevalence, SCA type 2 (SCA2) and type 3 (SCA3), which are caused by expanded forms of ataxin-2 (ATXN2) and ataxin-3 (ATXN3), respectively. The pathophysiology of polyglutamine diseases has been described to involve an inability to properly respond to cell stress. We evaluated the ability of GTPase-activating protein-binding protein 1 (G3BP1), an RNA-binding protein involved in RNA metabolism regulation and stress responses, to counteract SCA2 and SCA3 pathology, using both in vitro and in vivo disease models. Our results indicate that G3BP1 overexpression in cell models leads to a reduction of ATXN2 and ATXN3 aggregation, associated with a decrease in protein expression. This protective effect of G3BP1 against polyglutamine protein aggregation was reinforced by the fact that silencing G3bp1 in the mouse brain increases human expanded ATXN2 and ATXN3 aggregation. Moreover, a decrease of G3BP1 levels was detected in cells derived from patients with SCA2 and SCA3, suggesting that G3BP1 function is compromised in the context of these diseases. In lentiviral mouse models of SCA2 and SCA3, G3BP1 overexpression not only decreased protein aggregation but also contributed to the preservation of neuronal cells. Finally, in an SCA3 transgenic mouse model with a severe ataxic phenotype, G3BP1 lentiviral delivery to the cerebellum led to amelioration of several motor behavioural deficits. Overall, our results indicate that a decrease in G3BP1 levels may be a contributing factor to SCA2 and SCA3 pathophysiology, and that administration of this protein through viral vector-mediated delivery may constitute a putative approach to therapy for these diseases, and possibly other polyglutamine disorders.


Assuntos
Doença de Machado-Joseph , Ataxias Espinocerebelares , Humanos , Camundongos , Animais , DNA Helicases/metabolismo , Proteínas de Choque Térmico , Agregados Proteicos , Grânulos de Estresse , Proteínas de Ligação a Poli-ADP-Ribose/genética , RNA Helicases/genética , RNA Helicases/metabolismo , Proteínas com Motivo de Reconhecimento de RNA/genética , Ataxias Espinocerebelares/genética , Ataxias Espinocerebelares/patologia , Ataxina-3/genética , Camundongos Transgênicos , Doença de Machado-Joseph/genética
4.
Int J Mol Sci ; 23(19)2022 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-36233198

RESUMO

Spinocerebellar ataxia type 2 (SCA2) is a rare autosomal, dominantly inherited disease, in which the affected individuals have a disease onset around their third life decade. The molecular mechanisms underlying SCA2 are not yet completely understood, for which we hypothesize that aging plays a role in SCA2 molecular pathogenesis. In this study, we performed a striatal injection of mutant ataxin-2 mediated by lentiviral vectors, in young and aged animals. Twelve weeks post-injection, we analyzed the striatum for SCA2 neuropathological features and specific aging hallmarks. Our results show that aged animals had a higher number of mutant ataxin-2 aggregates and more neuronal marker loss, compared to young animals. Apoptosis markers, cleaved caspase-3, and cresyl violet staining also indicated increased neuronal death in the aged animal group. Additionally, mRNA levels of microtubule-associated protein 1 light-chain 3B (LC3) and sequestosome-1 (SQSTM1/p62) were altered in the aged animal group, suggesting autophagic pathway dysfunction. This work provides evidence that aged animals injected with expanded ataxin-2 had aggravated SCA2 disease phenotype, suggesting that aging plays an important role in SCA2 disease onset and disease progression.


Assuntos
Ataxina-2 , Ataxias Espinocerebelares , Animais , Ataxina-2/genética , Ataxina-2/metabolismo , Ataxina-3/genética , Caspase 3/metabolismo , Proteínas Associadas aos Microtúbulos/metabolismo , RNA Mensageiro , Proteína Sequestossoma-1/genética , Proteína Sequestossoma-1/metabolismo , Ataxias Espinocerebelares/patologia
5.
ACS Nano ; 15(3): 3754-3807, 2021 03 23.
Artigo em Inglês | MEDLINE | ID: mdl-33650433

RESUMO

X-ray-based analytics are routinely applied in many fields, including physics, chemistry, materials science, and engineering. The full potential of such techniques in the life sciences and medicine, however, has not yet been fully exploited. We highlight current and upcoming advances in this direction. We describe different X-ray-based methodologies (including those performed at synchrotron light sources and X-ray free-electron lasers) and their potentials for application to investigate the nano-bio interface. The discussion is predominantly guided by asking how such methods could better help to understand and to improve nanoparticle-based drug delivery, though the concepts also apply to nano-bio interactions in general. We discuss current limitations and how they might be overcome, particularly for future use in vivo.


Assuntos
Nanopartículas , Síncrotrons , Lasers , Radiografia , Raios X
6.
Sensors (Basel) ; 20(21)2020 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-33143075

RESUMO

When performing structural inspection, the generation of three-dimensional (3D) point clouds is a common resource. Those are usually generated from photogrammetry or through laser scan techniques. However, a significant drawback for complete inspection is the presence of covering vegetation, hiding possible structural problems, and making difficult the acquisition of proper object surfaces in order to provide a reliable diagnostic. Therefore, this research's main contribution is developing an effective vegetation removal methodology through the use of a deep learning structure that is capable of identifying and extracting covering vegetation in 3D point clouds. The proposed approach uses pre and post-processing filtering stages that take advantage of colored point clouds, if they are available, or operate independently. The results showed high classification accuracy and good effectiveness when compared with similar methods in the literature. After this step, if color is available, then a color filter is applied, enhancing the results obtained. Besides, the results are analyzed in light of real Structure From Motion (SFM) reconstruction data, which further validates the proposed method. This research also presented a colored point cloud library of bushes built for the work used by other studies in the field.


Assuntos
Aprendizado Profundo , Plantas , Movimento (Física) , Fotogrametria
7.
Sensors (Basel) ; 20(19)2020 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-32992814

RESUMO

The Industry 4.0 paradigm, since its initial conception in Germany in 2011, has extended its scope and adoption to a broader set of technologies. It is being considered as the most vital mechanism in the production systems lifecycle. It is the key element in the digital transformation of manufacturing industry all over the world. This scenario imposes a set of major unprecedented challenges which require to be overcome. In order to enable integration in horizontal, vertical, and end-to-end formats, one of the most critical aspects of this digital transformation process consists of effectively coupling digital integrated service/products business models with additive manufacturing processes. This integration is based upon advanced AI-based tools for decentralized decision-making and for secure and trusted data sharing in the global value. This paper presents the FASTEN IIoT Platform, which targets to provide a flexible, configurable, and open solution. The platform acts as an interface between the shop floor and the industry 4.0 advanced applications and solutions. Examples of these efforts comprise management, forecasting, optimization, and simulation, by harmonizing the heterogeneous characteristics of the data sources involved while meeting real-time requirements.

8.
BMC Res Notes ; 13(1): 210, 2020 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-32276655

RESUMO

OBJECTIVE: Compromised brain cholesterol turnover and altered regulation of brain cholesterol metabolism have been allied with some neurodegenerative diseases, including Huntington's disease (HD). Following our previous studies in HD, in this study we aim to investigate in vitro in a neuroblastoma cellular model of HD, the effect of CYP46A1 overexpression, an essential enzyme in cholesterol metabolism, on huntingtin aggregation and levels. RESULTS: We found that CYP46A1 reduces the quantity and size of mutant huntingtin aggregates in cells, as well as the levels of mutant huntingtin protein. Additionally, our results suggest that the observed beneficial effects of CYP46A1 in HD cells are linked to the activation of autophagy. Taken together, our results further demonstrate that CYP46A1 is a pertinent target to counteract HD progression.


Assuntos
Autofagia , Colesterol 24-Hidroxilase/metabolismo , Proteína Huntingtina/metabolismo , Doença de Huntington/metabolismo , Neuroblastoma , Animais , Linhagem Celular Tumoral , Células Cultivadas , Doença de Huntington/enzimologia , Camundongos , Proteínas Mutantes
9.
Rev. Odontol. Araçatuba (Impr.) ; 39(3): 25-31, set.-dez. 2018. ilus
Artigo em Português | LILACS, BBO - Odontologia | ID: biblio-967147

RESUMO

As fissuras labiopalatais são malformações congênitas faciais resultantes da falha no mecanismo de fusão dos processos frontonasais laterais com os processos mediais maxilares entre a oitava e a décima segunda semana de vida intrauterina, apresentando uma etiologia multifatorial. O presente estudo teve como objetivo apresentar a utilização de um retalho miomucoso de língua para o tratamento de fístula complexa em palato duro, secundária ao insucesso de uma palatoplastia primária. Paciente do sexo masculino, 15 anos de idade, portador de fissura labial bilateral transforame, apresentou-se ao Hospital Santo Antônio das Obras Sociais Irmã Dulce para tratamento de fístula em região de palato. Após preparo pré-operatório, o paciente foi submetido a procedimento cirúrgico, sob anestesia geral, para fechamento da fístula utilizando-se um retalho pediculado de língua com base na porção anterior da mesma. O retalho foi mantido pediculado cerca de 01 mês, período imprescindível para integração do enxerto na área receptora. Após esse período, realizou-se novo procedimento para soltar o pedículo e moldar o enxerto de tecido mole ao palato. Observou-se no pós-operatório da segunda intervenção, boa integração do enxerto de língua ao palato, fechamento da fístula palatina, permanecendo apenas um pequeno orifício residual comunicando com a cavidade nasal. Constatou-se ainda melhora de funções como dicção das palavras, deglutição e do som anasalado da fala do paciente, e, consequentemente, da sua qualidade de vida. A técnica mostrou-se uma opção efetiva para a reabilitação das grandes fístulas palatinas e exige uma atuação interdisciplinar para execução do protocolo de tratamento(AU)


The labiopalatal fissures are congenital facial badly formations resulting from the failure of the fusion mechanism of the lateral frontonasal processes with the maxillary medial processes between the eighth and tenth week of intrauterine life, presenting a multifactorial etiology. The present study aimed to present the use of a tongue myomucosal flap for the treatment of complex fistula in the hard palate, secondary to the failure of a primary palatoplasty. A 15-year-old male patient with transforame bilateral cleft lip, presented to Hospital Santo Antônio das Obras Sociais Irmã Dulce for treatment of fistula in the palate region. After preoperative preparation, the patient underwent a surgical procedure, under general anesthesia, to close the fistula using a pedicled tongue flap based on the anterior portion of the same. The flap was kept pediculated around 30 days, an essential period for graft integration in the recipient area. After this period, a new procedure was accomplished to drop the pedicle and to shape the soft tissue graft to the palate. In the second intervention, postoperative period, a good integration of the tongue graft to the palate was observed, closing the palatine fistula, remaining only a small residual orifice communicating with the nasal cavity. There was also an improvement in functions such as word diction, swallowing, and the patient's speech nasal sound. The technique proved to be an effective option for the closure of the large palatine fistulas, providing an excellent rehabilitation and, consequently, an improvement in the patient's quality of life(AU)


Assuntos
Humanos , Masculino , Adolescente , Retalhos Cirúrgicos , Fenda Labial , Fissura Palatina , Língua
10.
Oncol Rep ; 37(3): 1487-1496, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28184927

RESUMO

Clear cell renal cell carcinoma (ccRCC) is the most common histological subtype of kidney cancer. This carcinoma is histologically characterized by the presence of clear and abundant cytoplasm. In the present study, we sought to identify genes differentially expressed in ccRCC and build a molecular profile of this cancer. We selected genes described in the literature related to cellular differentiation and proliferation. We analyzed the gene and protein expression by quantitative PCR (qPCR) and immunohistochemistry, respectively, and examined possible epigenetic mechanisms that regulate their expression in ccRCC samples and cell lines. Occludin (OCLN) and growth arrest-specific 1 (GAS1) genes were underexpressed in ccRCC, and we report that miR-122 and miR-34a, respectively, may regulate their expression in this cancer. Furthermore, we showed by qPCR and immunohistochemistry that solute carrier family 2 member 1 (SLC2A1) was significantly overexpressed in ccRCC. The set of genes identified in the present study furthers our understanding of the molecular basis and development of ccRCC.


Assuntos
Carcinoma de Células Renais/metabolismo , Proteínas de Ciclo Celular/metabolismo , Neoplasias Renais/metabolismo , MicroRNAs/genética , Ocludina/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Apoptose , Biomarcadores Tumorais , Carcinoma de Células Renais/genética , Carcinoma de Células Renais/patologia , Proteínas de Ciclo Celular/genética , Proliferação de Células , Imunoprecipitação da Cromatina , Feminino , Proteínas Ligadas por GPI/genética , Proteínas Ligadas por GPI/metabolismo , Regulação Neoplásica da Expressão Gênica , Humanos , Técnicas Imunoenzimáticas , Neoplasias Renais/genética , Neoplasias Renais/patologia , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Ocludina/genética , Prognóstico , RNA Mensageiro/genética , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Células Tumorais Cultivadas , Adulto Jovem
11.
BMC Cancer ; 16(1): 840, 2016 11 03.
Artigo em Inglês | MEDLINE | ID: mdl-27809811

RESUMO

BACKGROUND: High-risk human papillomaviruses (HPVs) are strongly associated with the development of some malignancies. The E6 and E7 viral oncoproteins are the primary proteins responsible for cell homeostasis alteration and immortalization. Furthermore, the E6 protein from high-risk HPVs can interact with the PDZ (PSD-90/Dlg/ZO-1) domains of cellular proteins, triggering cell transformation. One protein that is associated with pathological conditions and has a PDZ domain is the protease HTRA1 (high temperature requirement 1). This protein is poorly expressed in some cancers, suggesting a tumor suppressor role. The aim of this study was to evaluate the effect of HTRA1 overexpression in HPV16-positive (CasKi) and HPV-negative (C33) cervical cell lines. METHODS: The cells were transfected with a vector containing the HTRA1 ORF or an empty vector. HTRA1 overexpression was confirmed by qRT-PCR. The cells were subjected to cell proliferation, colony formation, apoptosis and cell cycle assays. RESULTS: C33 cells expressing HTRA1 grew significantly fewer colonies and showed less proliferation than cells without HTRA1 expression. In contrast, in the CasKi cells overexpressing HTRA1, there was an increase in the cell growth rate and in the colonies density compared to cells expressing low levels of HTRA1. An apoptosis assay showed that HTRA1 does not interfere with the apoptosis rate in these cells. A cell cycle immunofluorescence assay revealed more CasKi cells overexpressing HTRA1 in the S phase and more C33 HTRA1-transfected cells in the G0/G1 phase, suggesting that HTRA1 plays different roles in the cell cycle progression of these cells. CONCLUSIONS: HTRA1 overexpression prevents cell proliferation in the HPV-negative cell line and increases cell proliferation in the HPV-positive cell line. Although the E6/HTRA1 interaction has already been described in the literature, more studies are required to confirm whether the present functional findings are a result of this interaction.


Assuntos
Proliferação de Células , Transformação Celular Neoplásica/patologia , Papillomaviridae/patogenicidade , Infecções por Papillomavirus/patologia , Serina Endopeptidases/metabolismo , Neoplasias do Colo do Útero/patologia , Apoptose , Ciclo Celular , Transformação Celular Neoplásica/metabolismo , Feminino , Serina Peptidase 1 de Requerimento de Alta Temperatura A , Humanos , Infecções por Papillomavirus/metabolismo , Infecções por Papillomavirus/virologia , Células Tumorais Cultivadas , Neoplasias do Colo do Útero/metabolismo , Neoplasias do Colo do Útero/virologia
12.
J Cancer ; 6(7): 593-603, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26078788

RESUMO

Though benign, giant cell tumor of bone (GCTB) can become aggressive and can exhibit a high mitotic rate, necrosis and rarely vascular invasion and metastasis. GCTB has unique histologic characteristics, a high rate of multinucleated cells, a variable and unpredictable growth potential and uncertain biological behavior. In this study, we sought to identify genes differentially expressed in GCTB, thus building a molecular profile of this tumor. We performed quantitative real-time polymerase chain reaction (qPCR), immunohistochemistry and analyses of methylation to identify genes that are putatively associated with GCTB. The expression of the ADAM23 and CDKN2A genes was decreased in GCTB samples compared to normal bone tissue, measured by qPCR. Additionally, a high hypermethylation frequency of the promoter regions of ADAM23 and CDKN2A in GCTB was observed. The expression of the MAP2K3, MMP14, TIMP2 and VIM genes was significantly higher in GCTB than in normal bone tissue, a fact that was confirmed by qPCR and immunohistochemistry. The set of genes identified here furthers our understanding of the molecular basis of GCTB.

13.
BMC Cancer ; 14: 631, 2014 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-25168166

RESUMO

BACKGROUND: Glypican 3 (GPC3) is a member of the family of glypican heparan sulfate proteoglycans (HSPGs). The GPC3 gene may play a role in controlling cell migration, negatively regulating cell growth and inducing apoptosis. GPC3 is downregulated in several cancers, which can result in uncontrolled cell growth and can also contribute to the malignant phenotype of some tumors. The purpose of this study was to analyze the mechanism of action of the GPC3 gene in clear cell renal cell carcinoma. METHODS: Five clear cell renal cell carcinoma cell lines and carcinoma samples were used to analyze GPC3 mRNA expression (qRT-PCR). Then, representative cell lines, one primary renal carcinoma (786-O) and one metastatic renal carcinoma (ACHN), were chosen to carry out functional studies. We constructed a GPC3 expression vector and transfected the renal carcinoma cell lines, 786-O and ACHN. GPC3 overexpression was analyzed using qRT-PCR and immunocytochemistry. We evaluated cell proliferation using MTT and colony formation assays. Flow cytometry was used to evaluate apoptosis and perform cell cycle analyses. RESULTS: We observed that GPC3 is downregulated in clear cell renal cell carcinoma samples and cell lines compared with normal renal samples. GPC3 mRNA expression and protein levels in 786-O and ACHN cell lines increased after transfection with the GPC3 expression construct, and the cell proliferation rate decreased in both cell lines following overexpression of GPC3. Further, apoptosis was not induced in the renal cell carcinoma cell lines overexpressing GPC3, and there was an increase in the cell population during the G1 phase in the cell cycle. CONCLUSION: We suggest that the GPC3 gene reduces the rate of cell proliferation through cell cycle arrest during the G1 phase in renal cell carcinoma.


Assuntos
Carcinoma de Células Renais/patologia , Glipicanas/genética , Glipicanas/metabolismo , Neoplasias Renais/patologia , Apoptose , Carcinoma de Células Renais/genética , Carcinoma de Células Renais/metabolismo , Ciclo Celular , Linhagem Celular Tumoral , Proliferação de Células , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Neoplasias Renais/genética , Neoplasias Renais/metabolismo , Masculino , Pessoa de Meia-Idade
14.
Virchows Arch ; 458(4): 467-76, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21305317

RESUMO

Giant cells tumors of bone (GCTB) are benign in nature but cause osteolytic destruction with a number of particular characteristics. These tumors can have uncertain biological behavior often contain a significant proportion of highly multinucleated cells, and may show aggressive behavior. We have studied differential gene expression in GCTB that may give a better understanding of their physiopathology, and might be helpful in prognosis and treatment. Rapid subtractive hybridization (RaSH) was used to identify and measure novel genes that appear to be differentially expressed, including KTN1, NEB, ROCK1, and ZAK using quantitative real-time polymerase chain reaction (qRT-PCR) and immunohistochemistry in the samples of GCTBs compared to normal bone tissue. Normal bone was used in the methodology RaSH for comparison with the GCTB in identification of differentially expressed genes. Functional annotation indicated that these genes are involved in cellular processes related to their tumor phenotype. The differential expression of KTN1, ROCK1, and ZAK was independently confirmed by qRT-PCR and immunohistochemistry. The expression of the KTN1 and ROCK1 genes were increased in samples by qRT-PCR and immunohistochemistry, and ZAK had reduced expression. Since ZAK have CpG islands in their promoter region and low expression in tumor tissue, their methylation pattern was analyzed by MSP-PCR. The genes identified KTN1, ROCK1, and ZAK may be responsible for loss of cellular homeostasis in GCTB since they are responsible for various functions related to tumorigenesis such as cell migration, cytoskeletal organization, apoptosis, and cell cycle control and thus may contribute at some stage in the process of formation and development of GCTB.


Assuntos
Neoplasias Ósseas/genética , Tumor de Células Gigantes do Osso/genética , Proteínas de Membrana/biossíntese , Proteínas Quinases/biossíntese , Quinases Associadas a rho/biossíntese , Adolescente , Adulto , Idoso , Neoplasias Ósseas/metabolismo , Metilação de DNA/genética , Feminino , Expressão Gênica , Perfilação da Expressão Gênica , Tumor de Células Gigantes do Osso/metabolismo , Humanos , Imuno-Histoquímica , Hibridização In Situ , MAP Quinase Quinase Quinases , Masculino , Proteínas de Membrana/genética , Pessoa de Meia-Idade , Proteínas Quinases/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Adulto Jovem , Quinases Associadas a rho/genética
15.
Analyst ; 134(6): 1077-82, 2009 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19475132

RESUMO

Small angle X-ray scattering (SAXS) images of normal breast tissue and benign and malignant breast tumour tissues, fixed in formalin, were measured at the momentum transfer range of 0.063 nm(-1) < or = q (= 4pisin(theta/2)/lambda) < or = 2.720 nm(-1). Four intrinsic parameters were extracted from the scattering profiles (1D SAXS image reduced) and, from the combination of these parameters, another three parameters were also created. All parameters, intrinsic and derived, were subject to discriminant analysis, and it was verified that parameters such as the area of diffuse scatter at the momentum transfer range 0.50 < or = q < or = 0.56 nm(-1), the ratio between areas of fifth-order axial and third-order lateral peaks and third-order axial spacing provide the most significant information for diagnosis (p < 0.001). Thus, in this work it was verified that by combining these three parameters it was possible to classify human breast tissues as normal, benign lesion or malignant lesion with a sensitivity of 83% and a specificity of 100%.


Assuntos
Neoplasias da Mama/patologia , Espalhamento a Baixo Ângulo , Difração de Raios X , Adulto , Idoso , Mama/citologia , Mama/metabolismo , Mama/patologia , Neoplasias da Mama/metabolismo , Análise Discriminante , Formaldeído/metabolismo , Humanos , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Adulto Jovem
16.
J Radiat Res ; 49(5): 527-32, 2008 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-18667793

RESUMO

An investigation was carried out to study the potential use of the angular distribution of scattered photons by human breast samples for a rapid identification of neoplasias of breast tissues. This technique has possible applications as diagnostic aid for breast cancer. In this work, a commercial powder diffractometer was used to obtain the scattering profiles from breast tissues histopathologically classified as normal breast tissues, fibroadenomas (benign breast diseases) and carcinomas (malignant breast diseases), in the interval 0.02A(-1) < x < 0.62A(-1). The experimental methods and data corrections are discussed in detail, and they included background subtraction, polarization, self-attenuation and geometric effects. The validation of the experimental procedure was achieved through an analysis of water sample. The results showed that the scattering profile is a unique impression of each type of tissue, being correlated with their microscopic morphological features. Multivariate analysis was applied to these profiles in order to verify if the information carried by these scattering profiles allow the differentiation between normal, benign and malignant breast tissues. The statistical analysis results showed that a correct identification of 75% of the analyzed samples is accomplished. The values of sensibility and specificity of this method in correctly differentiating between normal and neoplastic samples were 95.6% and 82.3%, respectively, while the values for differentiation between benign and malignant neoplasias were 78.6% and 62.5%. These initial results indicate the feasible use of commercial powder diffractometer to provide a rapid diagnostic with a high sensitivity.


Assuntos
Neoplasias da Mama/classificação , Neoplasias da Mama/diagnóstico , Diagnóstico por Computador/métodos , Prótons , Refratometria/instrumentação , Desenho de Equipamento , Análise de Falha de Equipamento , Feminino , Humanos , Pós , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
17.
Anal Bioanal Chem ; 378(3): 798-803, 2004 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-14689153

RESUMO

This paper proposes a preconcentration procedure for determination of nickel in saline aqueous waste samples by flame atomic absorption spectrometry (FAAS). It is based on cloud-point extraction of nickel(II) ions as 2-(5-bromo-2-pyridylazo)-5-diethilaminophenol (Br-PADAP) complexes using octylphenoxypolyethoxyethanol (Triton X-114) as surfactant. The optimisation step was performed using a four-variable Doehlert design, involving the factors centrifugation time (CT) of system after addition of surfactant, solution pH, methanol volume (MV) added at micellar phase, and buffer concentration (BC). The analytical response used was absorbance, after volume correction. Using the established experimental conditions in the optimisation step the procedure enables nickel determination with a detection limit (3 delta/ S) of 0.2 microg L(-1), quantification limit (10 delta/ S) of 0.7 microg L(-1), and precision, calculated as relative standard deviation ( RSD) of 4.7 ( n=8) and 3.5% ( n=8) for nickel concentration of 1 and 5 microg L(-1), respectively. The preconcentration factor, determined from the ratio of the slopes of the analytical curves with and without preconcentration, is 74. The recovery achieved for nickel determination in the presence of several cations demonstrated that this procedure could be applied for analysis of water samples. The robustness was checked by using saturated fractional factorial designs, centred on the established experimental conditions in the optimisation step. The results of these tests demonstrated that the variables centrifugation time and buffer concentration are robust for modification by 10% and that solution pH and methanol volume are robust for 5%. Accuracy was evaluated by using the certified material reference SLEW-3 estuarine water for trace metals. The procedure was used for determination of nickel in saline effluents from oil refinery samples. Recovery results (95-104%) indicate that the procedure has satisfactory accuracy for nickel determination in these samples.

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