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1.
EMBO J ; 43(14): 2878-2907, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38816652

RESUMO

In mice, γδ-T lymphocytes that express the co-stimulatory molecule, CD27, are committed to the IFNγ-producing lineage during thymic development. In the periphery, these cells play a critical role in host defense and anti-tumor immunity. Unlike αß-T cells that rely on MHC-presented peptides to drive their terminal differentiation, it is unclear whether MHC-unrestricted γδ-T cells undergo further functional maturation after exiting the thymus. Here, we provide evidence of phenotypic and functional diversity within peripheral IFNγ-producing γδ T cells. We found that CD27+ Ly6C- cells convert into CD27+Ly6C+ cells, and these CD27+Ly6C+ cells control cancer progression in mice, while the CD27+Ly6C- cells cannot. The gene signatures of these two subsets were highly analogous to human immature and mature γδ-T cells, indicative of conservation across species. We show that IL-27 supports the cytotoxic phenotype and function of mouse CD27+Ly6C+ cells and human Vδ2+ cells, while IL-27 is dispensable for mouse CD27+Ly6C- cell and human Vδ1+ cell functions. These data reveal increased complexity within IFNγ-producing γδ-T cells, comprising immature and terminally differentiated subsets, that offer new insights into unconventional T-cell biology.


Assuntos
Antígenos Ly , Receptores de Antígenos de Linfócitos T gama-delta , Membro 7 da Superfamília de Receptores de Fatores de Necrose Tumoral , Animais , Camundongos , Antígenos Ly/metabolismo , Antígenos Ly/genética , Membro 7 da Superfamília de Receptores de Fatores de Necrose Tumoral/metabolismo , Membro 7 da Superfamília de Receptores de Fatores de Necrose Tumoral/genética , Membro 7 da Superfamília de Receptores de Fatores de Necrose Tumoral/imunologia , Humanos , Receptores de Antígenos de Linfócitos T gama-delta/metabolismo , Receptores de Antígenos de Linfócitos T gama-delta/imunologia , Receptores de Antígenos de Linfócitos T gama-delta/genética , Interferon gama/metabolismo , Interferon gama/imunologia , Interleucina-27/metabolismo , Interleucina-27/genética , Diferenciação Celular/imunologia , Camundongos Endogâmicos C57BL , Linfócitos T Citotóxicos/imunologia , Linfócitos T Citotóxicos/metabolismo
2.
Nat Genet ; 56(3): 458-472, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38351382

RESUMO

Molecular stratification using gene-level transcriptional data has identified subtypes with distinctive genotypic and phenotypic traits, as exemplified by the consensus molecular subtypes (CMS) in colorectal cancer (CRC). Here, rather than gene-level data, we make use of gene ontology and biological activation state information for initial molecular class discovery. In doing so, we defined three pathway-derived subtypes (PDS) in CRC: PDS1 tumors, which are canonical/LGR5+ stem-rich, highly proliferative and display good prognosis; PDS2 tumors, which are regenerative/ANXA1+ stem-rich, with elevated stromal and immune tumor microenvironmental lineages; and PDS3 tumors, which represent a previously overlooked slow-cycling subset of tumors within CMS2 with reduced stem populations and increased differentiated lineages, particularly enterocytes and enteroendocrine cells, yet display the worst prognosis in locally advanced disease. These PDS3 phenotypic traits are evident across numerous bulk and single-cell datasets, and demark a series of subtle biological states that are currently under-represented in pre-clinical models and are not identified using existing subtyping classifiers.


Assuntos
Neoplasias Colorretais , Humanos , Neoplasias Colorretais/patologia , Prognóstico , Diferenciação Celular/genética , Fenótipo , Biomarcadores Tumorais/genética , Perfilação da Expressão Gênica
3.
Front Toxicol ; 5: 1200650, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37441092

RESUMO

Hypothesis: Asbestos-driven inflammation contributes to malignant pleural mesothelioma beyond the acquisition of rate-limiting mutations. Methods: Genetically modified conditional allelic mice that were previously shown to develop mesothelioma in the absence of exposure to asbestos were induced with lentiviral vector expressing Cre recombinase with and without intrapleural injection of amosite asbestos and monitored until symptoms required euthanasia. Resulting tumours were examined histologically and by immunohistochemistry for expression of lineage markers and immune cell infiltration. Results: Injection of asbestos dramatically accelerated disease onset and end-stage tumour burden. Tumours developed in the presence of asbestos showed increased macrophage infiltration. Pharmacological suppression of macrophages in mice with established tumours failed to extend survival or to enhance response to chemotherapy. Conclusion: Asbestos-driven inflammation contributes to the severity of mesothelioma beyond the acquisition of rate-limiting mutations, however, targeted suppression of macrophages in established epithelioid mesothelioma showed no therapeutic benefit.

4.
Cell Death Differ ; 29(3): 514-526, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-34628485

RESUMO

The p53 transcription factor coordinates wide-ranging responses to stress that contribute to its function as a tumour suppressor. The responses to p53 induction are complex and range from mediating the elimination of stressed or damaged cells to promoting survival and repair. These activities of p53 can modulate tumour development but may also play a role in pathological responses to stress such as tissue damage and repair. Using a p53 reporter mouse, we have previously detected strong induction of p53 activity in the liver of mice treated with the hepatotoxin carbon tetrachloride (CCl4). Here, we show that p53 functions to support repair and recovery from CCl4-mediated liver damage, control reactive oxygen species (ROS) and limit the development of hepatocellular carcinoma (HCC), in part through the activation of a detoxification cytochrome P450, CYP2A5 (CYP2A6 in humans). Our work demonstrates an important role for p53-mediated redox control in facilitating the hepatic regenerative response after damage and identifies CYP2A5/CYP2A6 as a mediator of this pathway with potential prognostic utility in human HCC.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Animais , Tetracloreto de Carbono/toxicidade , Carcinoma Hepatocelular/patologia , Fígado/metabolismo , Neoplasias Hepáticas/patologia , Regeneração Hepática , Camundongos , Oxirredução , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo
5.
J Electr Bioimpedance ; 13(1): 96-105, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36694882

RESUMO

Bioelectrical impedance analysis (BIA) reference values are based on supine assessments. Little is known regarding the effects of time course shifts in body water compartments after assuming a supine position. The aim of this study was to characterize these effects and provide recommendations regarding the optimal waiting time to perform BIA. Thirty-eight healthy adults underwent BIA via the RJL Quantum Legacy analyzer immediately upon lying down and every 5 minutes for 15 minutes. Differences in resistance (R), reactance (Xc), intracellular (ICW), extracellular (ECW), total body water (TBW), body fat percentage (%BF), and phase angle (PhA) were assessed. There were small but significant increases in R, Xc, and %BF (all p<0.001), as well as small but significant decreases in ICW, ECW, and TBW (all p<0.001) over 15 minutes. No difference was observed for PhA (p=0.065). Average values changed over 15 minutes by +7.14Ω, +1.36Ω, -0.2L, -0.2L, -0.4L, +0.05° and +0.1% for R, Xc, ICW, ECW, TBW, PhA and %BF, respectively. BIA measurements are affected by shifts in body water compartments after assuming a supine position, but these differences lack clinical significance in healthy adults. Technicians working with healthy adults can perform BIA within 15 minutes after participants assume a supine position.

6.
Artigo em Inglês | MEDLINE | ID: mdl-34886405

RESUMO

Background: Multiple sclerosis (MS) is associated with lower quality of life, reduced social participation, and decreased self-efficacy. The COVID-19 pandemic has had documented effects on the health and wellbeing of people with and without MS. Previous research has demonstrated the positive impact pets can have for people living with long-term conditions. Objectives: To explore the rates of pet ownership and pet attachment in people living with MS and pet ownership associations with quality of life, satisfaction with social roles, and self-efficacy scores; and to explore the effects of the COVID-19 outbreak on people's perceived relationships with their pets. Materials and Methods: A postal questionnaire was distributed to members of a local MS Register and a control group of people without MS. The questionnaire assessed quality of life, satisfaction with social roles, self-efficacy, the perceived roles of pets, and pet-related concerns experienced during the COVID-19 pandemic. Results: No apparent difference in attachment to pets was found between the patient and control groups. Pet ownership and level of attachment were not associated with differences in quality of life or self-efficacy scores in people living with MS. Using multiple regression analysis, pet ownership was associated with a decrease in satisfaction with participation in social roles, but with the estimated effect being small compared to having a diagnosis of MS or being unemployed. Most participants reported that pets had positive roles during the pandemic, and the most reported pet-related concern was access to veterinary treatment. Conclusion: Pet owners both with and without MS reported subjective benefits to their wellbeing from pet ownership during COVID-19, although analysis suggested that pet ownership was associated with a reduction in satisfaction with social roles. The study had several limitations and suggestions are made for future work.


Assuntos
COVID-19 , Esclerose Múltipla , Animais , Humanos , Propriedade , Pandemias , Animais de Estimação , Qualidade de Vida , SARS-CoV-2
7.
Nat Commun ; 12(1): 6829, 2021 11 24.
Artigo em Inglês | MEDLINE | ID: mdl-34819513

RESUMO

Signals are relayed from receptor tyrosine kinases (RTKs) at the cell surface to effector systems in the cytoplasm and nucleus, and coordination of this process is important for the execution of migratory phenotypes, such as cell scattering and invasion. The endosomal system influences how RTK signalling is coded, but the ways in which it transmits these signals to the nucleus to influence gene expression are not yet clear. Here we show that hepatocyte growth factor, an activator of MET (an RTK), promotes Rab17- and clathrin-dependent endocytosis of EphA2, another RTK, followed by centripetal transport of EphA2-positive endosomes. EphA2 then mediates physical capture of endosomes on the outer surface of the nucleus; a process involving interaction between the nuclear import machinery and a nuclear localisation sequence in EphA2's cytodomain. Nuclear capture of EphA2 promotes RhoG-dependent phosphorylation of the actin-binding protein, cofilin to oppose nuclear import of G-actin. The resulting depletion of nuclear G-actin drives transcription of Myocardin-related transcription factor (MRTF)/serum-response factor (SRF)-target genes to implement cell scattering and the invasive behaviour of cancer cells.


Assuntos
Núcleo Celular/metabolismo , Endossomos/metabolismo , Regulação Neoplásica da Expressão Gênica , Neoplasias/patologia , Fatores de Complexo Ternário/metabolismo , Actinas/metabolismo , Transporte Ativo do Núcleo Celular/genética , Animais , Linhagem Celular Tumoral , Citoplasma/metabolismo , Fator de Crescimento de Hepatócito/metabolismo , Humanos , Camundongos , Camundongos Knockout , Invasividade Neoplásica/genética , Receptores Proteína Tirosina Quinases/genética , Receptores Proteína Tirosina Quinases/metabolismo
8.
J Thorac Oncol ; 16(10): 1705-1717, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34116230

RESUMO

INTRODUCTION: Malignant pleural mesothelioma (MPM) is difficult to diagnose. An accurate blood biomarker could prompt specialist referral or be deployed in future screening. In earlier retrospective studies, SOMAscan proteomics (Somalogic, Boulder, CO) and fibulin-3 seemed highly accurate, but SOMAscan has not been validated prospectively and subsequent fibulin-3 data have been contradictory. METHODS: A multicenter prospective observational study was performed in 22 centers, generating a large intention-to-diagnose cohort. Blood sampling, processing, and diagnostic assessment were standardized, including a 1-year follow-up. Plasma fibulin-3 was measured using two enzyme-linked immunosorbent assays (CloudClone [used in previous studies] and BosterBio, Pleasanton, CA). Serum proteomics was measured using the SOMAscan assay. Diagnostic performance (sensitivity at 95% specificity, area under the curve [AUC]) was benchmarked against serum mesothelin (Mesomark, Fujirebio Diagnostics, Malvern, PA). Biomarkers were correlated against primary tumor volume, inflammatory markers, and asbestos exposure. RESULTS: A total of 638 patients with suspected pleural malignancy (SPM) and 110 asbestos-exposed controls (AECs) were recruited. SOMAscan reliably differentiated MPM from AECs (75% sensitivity, 88.2% specificity, validation cohort AUC 0.855) but was not useful in patients with differentiating non-MPM SPM. Fibulin-3 (by BosterBio after failed CloudClone validation) revealed 7.4% and 11.9% sensitivity at 95% specificity in MPM versus non-MPM SPM and AECs, respectively (associated AUCs 0.611 [0.557-0.664], p = 0.0015) and 0.516 [0.443-0.589], p = 0.671), both inferior to mesothelin. SOMAscan proteins correlated with inflammatory markers but not with asbestos exposure. Neither biomarker correlated with tumor volume. CONCLUSIONS: SOMAscan may prove useful as a future screening test for MPM in asbestos-exposed persons. Neither fibulin-3 nor SOMAscan should be used for diagnosis or pathway stratification.


Assuntos
Amianto , Neoplasias Pulmonares , Mesotelioma , Neoplasias Pleurais , Biomarcadores Tumorais , Proteínas de Ligação ao Cálcio , Proteínas da Matriz Extracelular , Proteínas Ligadas por GPI , Humanos , Neoplasias Pulmonares/diagnóstico , Mesotelioma/diagnóstico , Mesotelioma/etiologia , Neoplasias Pleurais/diagnóstico , Neoplasias Pleurais/etiologia , Proteômica , Estudos Retrospectivos
9.
Nat Genet ; 53(1): 16-26, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33414552

RESUMO

Oncogenic KRAS mutations and inactivation of the APC tumor suppressor co-occur in colorectal cancer (CRC). Despite efforts to target mutant KRAS directly, most therapeutic approaches focus on downstream pathways, albeit with limited efficacy. Moreover, mutant KRAS alters the basal metabolism of cancer cells, increasing glutamine utilization to support proliferation. We show that concomitant mutation of Apc and Kras in the mouse intestinal epithelium profoundly rewires metabolism, increasing glutamine consumption. Furthermore, SLC7A5, a glutamine antiporter, is critical for colorectal tumorigenesis in models of both early- and late-stage metastatic disease. Mechanistically, SLC7A5 maintains intracellular amino acid levels following KRAS activation through transcriptional and metabolic reprogramming. This supports the increased demand for bulk protein synthesis that underpins the enhanced proliferation of KRAS-mutant cells. Moreover, targeting protein synthesis, via inhibition of the mTORC1 regulator, together with Slc7a5 deletion abrogates the growth of established Kras-mutant tumors. Together, these data suggest SLC7A5 as an attractive target for therapy-resistant KRAS-mutant CRC.


Assuntos
Neoplasias Colorretais/genética , Transportador 1 de Aminoácidos Neutros Grandes/metabolismo , Mutação/genética , Proteínas Proto-Oncogênicas p21(ras)/genética , Regiões 5' não Traduzidas/genética , Sistema ASC de Transporte de Aminoácidos/metabolismo , Animais , Carcinogênese/patologia , Proliferação de Células , Neoplasias Colorretais/patologia , Regulação Neoplásica da Expressão Gênica , Glutamina/metabolismo , Humanos , Mucosa Intestinal/metabolismo , Mucosa Intestinal/patologia , Estimativa de Kaplan-Meier , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Camundongos Endogâmicos C57BL , Antígenos de Histocompatibilidade Menor/metabolismo , Metástase Neoplásica , Oncogenes , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Transdução de Sinais , Serina-Treonina Quinases TOR/metabolismo
10.
Life Sci Alliance ; 3(12)2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33033111

RESUMO

Docetaxel chemotherapy in metastatic prostate cancer offers only a modest survival benefit because of emerging resistance. To identify candidate therapeutic gene targets, we applied a murine prostate cancer orthograft model that recapitulates clinical invasive prostate cancer in a genome-wide CRISPR/Cas9 screen under docetaxel treatment pressure. We identified 17 candidate genes whose suppression may enhance the efficacy of docetaxel, with transcription elongation factor A-like 1 (Tceal1) as the top candidate. TCEAL1 function is not fully characterised; it may modulate transcription in a promoter dependent fashion. Suppressed TCEAL1 expression in multiple human prostate cancer cell lines enhanced therapeutic response to docetaxel. Based on gene set enrichment analysis from transcriptomic data and flow cytometry, we confirmed that loss of TCEAL1 in combination with docetaxel leads to an altered cell cycle profile compared with docetaxel alone, with increased subG1 cell death and increased polyploidy. Here, we report the first in vivo genome-wide treatment sensitisation CRISPR screen in prostate cancer, and present proof of concept data on TCEAL1 as a candidate for a combinational strategy with the use of docetaxel.


Assuntos
Proteínas de Ligação a DNA/genética , Resistencia a Medicamentos Antineoplásicos/genética , Neoplasias da Próstata/genética , Fatores de Transcrição/genética , Animais , Sistemas CRISPR-Cas/genética , Linhagem Celular Tumoral , Repetições Palindrômicas Curtas Agrupadas e Regularmente Espaçadas/genética , Proteínas de Ligação a DNA/metabolismo , Docetaxel/farmacologia , Regulação Neoplásica da Expressão Gênica/genética , Engenharia Genética/métodos , Masculino , Camundongos , Camundongos Nus , Neoplasias da Próstata/metabolismo , Taxoides/farmacologia , Fatores de Transcrição/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto/métodos
11.
Cell Cycle ; 18(9): 963-975, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30973299

RESUMO

Common hallmarks of cancer include the dysregulation of cell cycle progression and the acquisition of genome instability. In tumors, G1 cell cycle checkpoint induction is often lost. This increases the reliance on a functional G2/M checkpoint to prevent progression through mitosis with damaged DNA, avoiding the introduction of potentially aberrant genetic alterations. Treatment of tumors with ionizing radiation (IR) utilizes this dependence on the G2/M checkpoint. Therefore, identification of factors which regulate this process could yield important biomarkers for refining this widely used cancer therapy. Leucine zipper and ICAT domain containing (LZIC) downregulation has been associated with the development of IR-induced tumors. However, despite LZIC being highly conserved, it has no known molecular function. We demonstrate that LZIC knockout (KO) cell lines show a dysregulated G2/M cell cycle checkpoint following IR treatment. In addition, we show that LZIC deficient cells competently activate the G1 and early G2/M checkpoint but fail to maintain the late G2/M checkpoint after IR exposure. Specifically, this defect was found to occur downstream of PIKK signaling. The LZIC KO cells demonstrated severe aneuploidy indicative of genomic instability. In addition, analysis of data from cancer patient databases uncovered a strong correlation between LZIC expression and poor prognosis in several cancers. Our findings suggest that LZIC is functionally involved in cellular response to IR, and its expression level could serve as a biomarker for patient stratification in clinical cancer practice.


Assuntos
Carcinoma de Células Renais/genética , Pontos de Checagem da Fase G2 do Ciclo Celular/genética , Pontos de Checagem da Fase G2 do Ciclo Celular/efeitos da radiação , Peptídeos e Proteínas de Sinalização Intracelular/genética , Neoplasias Renais/genética , Radiação Ionizante , Aneuploidia , Carcinoma de Células Renais/mortalidade , Sobrevivência Celular/genética , Sobrevivência Celular/efeitos da radiação , Quinase 1 do Ponto de Checagem/metabolismo , Dano ao DNA/genética , Dano ao DNA/efeitos da radiação , Bases de Dados Genéticas , Expressão Gênica , Técnicas de Inativação de Genes , Instabilidade Genômica/genética , Células HEK293 , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Neoplasias Renais/mortalidade , Prognóstico , Transdução de Sinais/genética , Transdução de Sinais/efeitos da radiação , Taxa de Sobrevida , Transfecção
12.
PLoS Negl Trop Dis ; 13(1): e0006805, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30640905

RESUMO

BACKGROUND: Across the world, ticks act as vectors of human and animal pathogens. Ticks rely on bacterial endosymbionts, which often share close and complex evolutionary links with tick-borne pathogens. As the prevalence, diversity and virulence potential of tick-borne agents remain poorly understood, there is a pressing need for microbial surveillance of ticks as potential disease vectors. METHODOLOGY/PRINCIPAL FINDINGS: We developed a two-stage protocol that includes 16S-amplicon screening of pooled samples of hard ticks collected from dogs, sheep and camels in Palestine, followed by shotgun metagenomics on individual ticks to detect and characterise tick-borne pathogens and endosymbionts. Two ticks isolated from sheep yielded an abundance of reads from the genus Rickettsia, which were assembled into draft genomes. One of the resulting genomes was highly similar to Rickettsia massiliae strain MTU5. Analysis of signature genes showed that the other represents the first genome sequence of the potential pathogen Candidatus Rickettsia barbariae. Ticks from a dog and a sheep yielded draft genome sequences of Coxiella strains. A sheep tick yielded sequences from the sheep pathogen Anaplasma ovis, while Hyalomma ticks from camels yielded sequences belonging to Francisella-like endosymbionts. From the metagenome of a dog tick from Jericho, we generated a genome sequence of a canine parvovirus. SIGNIFICANCE: Here, we have shown how a cost-effective two-stage protocol can be used to detect and characterise tick-borne pathogens and endosymbionts. In recovering genome sequences from an unexpected pathogen (canine parvovirus) and a previously unsequenced pathogen (Candidatus Rickettsia barbariae), we demonstrate the open-ended nature of metagenomics. We also provide evidence that ticks can carry canine parvovirus, raising the possibility that ticks might contribute to the spread of this troublesome virus.


Assuntos
Genoma Bacteriano/genética , Ixodes/microbiologia , Ixodes/virologia , Parvovirus Canino/isolamento & purificação , Rickettsia/isolamento & purificação , Anaplasma ovis/genética , Anaplasma ovis/isolamento & purificação , Animais , Camelus , Coxiella/classificação , Coxiella/genética , Coxiella/isolamento & purificação , DNA Bacteriano/genética , Cães , Francisella/classificação , Francisella/genética , Francisella/isolamento & purificação , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Insetos Vetores/genética , Insetos Vetores/microbiologia , Insetos Vetores/virologia , Israel/epidemiologia , Parvovirus Canino/genética , RNA Ribossômico 16S/genética , Rickettsia/classificação , Rickettsia/genética , Ovinos , Doenças Transmitidas por Carrapatos/epidemiologia
14.
Pain ; 44(1): 51-56, 1991 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-1828111

RESUMO

Few validated instruments are available to assess beliefs and attitudes that patients have regarding pain, or ability to function despite discomfort. The Pain and Impairment Relationship Scale (PAIRS) was developed to tap these important beliefs and attitudes in chronic pain patients. Preliminary data indicate that the PAIRS is internally consistent and significantly related to impairment in a highly selected pain clinic sample of patients, including some chronic low back pain patients. The present study was designed to extend the validation of the PAIRS to a more general sample of chronic benign low back pain patients. Furthermore, additional tests supported the discriminant, convergent and divergent validity, as well as the reliability and relative independence from favorable self-report response bias of the PAIRS, by respectively demonstrating that: (1) the impairment beliefs assessed with the PAIRS were more prominent in chronic low back pain (CLBP) patients than in matched non-pain, healthy controls; (2) scores on the PAIRS were significantly related to measures of physical impairment, but not to physicians ratings of disease severity; (3) the impairment beliefs assessed with the PAIRS are readily distinguishable from cognitive distortions and emotional distress; (4) PAIRS scores for chronic low back pain patients are relatively consistent over time; and (5) PAIRS scores are not significantly associated with measures of favorable self-report response bias. We conclude that the PAIRS has demonstrated at least preliminary utility for applications by researchers and clinicians interested in chronic pain.


Assuntos
Dor nas Costas/psicologia , Medição da Dor , Dor/psicologia , Adulto , Cognição/fisiologia , Depressão/psicologia , Avaliação da Deficiência , Emoções/fisiologia , Humanos , Masculino , Processos Mentais , Pessoa de Meia-Idade , Escalas de Graduação Psiquiátrica
15.
Langmuir ; 24(7): 3532-6, 2008 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-18312010

RESUMO

Using a water-in-oil microemulsion system, silica nanoparticles containing superparamagnetic iron oxide (SPIO) crystals have been prepared and characterized. With this method, the loading of iron oxide crystals, the thickness of the silica shells, and the overall particle sizes are tunable. Moving from low to high water concentration, within the microemulsion region, resulted in a gradual shift from larger particles, ca. 100 nm and fully loaded with SPIOs, to smaller particles, ca. 30 nm containing only one or a few SPIOs. By varying the amount of silica precursor, the thickness of the silica shell was altered. Field dependent magnetization measurements showed the magnetic properties of the SPIOs were preserved after the synthesis.

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