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1.
Urol Int ; 106(2): 154-162, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34352790

RESUMO

Background & Objectives: We aimed to evaluate the risk of progression in high-grade T1 (HGT1) tumors using tumor budding (TB) and other standard clinical and histological features. TB is defined as an isolated cancer cell or a cluster composed of fewer than 5 cells scattered in the stroma and is usually used as a strong predictor of lymph node metastasis in T1 colorectal cancer. METHODS: This is an observational longitudinal cohort study involving 168 consecutive patients with HGT1 between 2013 and 2016. Cox regression was performed to analyze the relationship between the clinical and histological features and progression. All slides were blindly assessed by 2 genitourinary pathologists. Budding was determined to be positive when the number of buds was equal to or greater than 6. RESULTS: The median age was 75 years; 152 (90.5%) patients were men, and 49 (29.2%) were positive for TB. At a median follow-up time of 35 months, 33 patients (19.6%) showed progression. Progression was observed in 32.7% of the patients positive for TB and in only 14.3% of those who were negative (p = 0.006). TB was significantly associated with the endoscopic tumor pattern (TP) (papillary/solid) and lymphovascular invasion (LVI). Univariate analysis showed that TB, carcinoma in situ (CIS), TP, LVI, sub-staging, and BCG induction predict progression. The multivariate analysis showed that TB (p = 0.032, hazard ratio 2.1), CIS, TP, and lack of BCG induction were significant for progression. CONCLUSIONS: TB is a new and significant pathological variable for predicting progression in HGT1 tumors and can be easily introduced in clinical practice. Its inclusion in the TNM system should be carefully considered, as it may aid early cystectomy decisions.


Assuntos
Cistectomia , Neoplasias da Bexiga Urinária/patologia , Neoplasias da Bexiga Urinária/cirurgia , Idoso , Estudos de Coortes , Progressão da Doença , Feminino , Humanos , Estudos Longitudinais , Masculino , Gradação de Tumores , Estudos Retrospectivos , Medição de Risco
2.
J Am Chem Soc ; 138(51): 16779-16786, 2016 12 28.
Artigo em Inglês | MEDLINE | ID: mdl-27977173

RESUMO

The α-and ß-phases of the thiazyl radical p-NCC6F4CNSSN• (1) can be selectively prepared by careful control of the sublimation conditions, with the α-phase crystallizing preferentially when the substrate temperature is maintained below -10 °C, whereas the ß-phase is isolated when the substrate temperature is maintained at or above ambient temperature. Differential scanning calorimatry studies reveal that the α-phase converts to the ß-phase upon warming over the range 111-117 °C (ΔH = +4 kJ·mol-1) via a melt-recrystallization process, with the ß-phase itself melting at 167-170 °C (ΔHfus = 27 kJ·mol-1). IR and Raman spectroscopy can be used to clearly discriminate between 1α and 1ß. The α-phase shows a broad maximum in the magnetic susceptibility around 8 K that, coupled with a broad maximum in the heat capacity, is indicative of short-range order. Some field dependence of the susceptibility below 3 K is observed, but the lack of features in the ac susceptibility, M vs H plots, or heat capacity mitigates against long-range order in 1α.

3.
Actas Urol Esp (Engl Ed) ; 47(5): 296-302, 2023 06.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-36443223

RESUMO

INTRODUCTION: Bladder cancer (BC) is a common malignancy in Spain. The aims of this study were: to identify the proportion of patients diagnosed with BC incidentally or after symptomatic presentation in a contemporary period in Spain; to compare demographic, clinical, and pathologic characteristics between these groups. METHODS: This was a retrospective analysis of a multi-centre observational study of 26 hospitals in the Spanish National Health System of all BCs newly diagnosed in 2011. The study represented 21.5% of the Spanish population and hospitals were selected in proportion to Spain's regions to ensure a representative sample. Patients were categorized by whether the cancer was diagnosed incidentally or after symptomatic presentation and baseline demographic, pathologic, and clinical characteristics were analyzed. RESULTS: 2472 were newly diagnosed with BC at the 26 participating Spanish hospitals with 308 (12.5%) of cases diagnosed incidentally and 2164 (87.5%) diagnosed after symptomatic presentation. No differences were observed between patients diagnosed incidentally vs. symptomatically in terms of demographics or measured co-morbidities. Compared to symptomatically diagnosed bladder tumours, those diagnosed incidentally were more likely to have a papillary appearance, to be significantly smaller, and less likely to have positive/suspicious cytology. Additionally, incidentally diagnosed bladder tumours were less likely to be muscle-invasive (11.7% vs. 25.0%, p < 0.01) nor aggressive at pathology, with 33.6% Grade 3 compared to 50.1%, (p < 0.01). CONCLUSIONS: We identified a significant percentage (12.5%) of new bladder cancer diagnosis made incidentally in a representative sample of the Spanish population. These tumours exhibited less aggressive pathologic characteristics than their symptomatic counterparts.


Assuntos
Neoplasias da Bexiga Urinária , Humanos , Estudos Retrospectivos , Espanha/epidemiologia , Neoplasias da Bexiga Urinária/diagnóstico , Neoplasias da Bexiga Urinária/epidemiologia , Neoplasias da Bexiga Urinária/patologia
4.
Langmuir ; 28(21): 8190-6, 2012 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-22554306

RESUMO

Stable, cost-effective, brightly luminescent, and metal-free organosilica nanoparticles (NPs) were prepared using the Stöber method without any thermal treatment above 318 K. The white-light photoluminescence results from a convolution of the emission originated in the NH(2) groups of the organosilane and oxygen defects in the silica network. The time-resolved emission spectra are red-shifted, relative to those acquired in the steady-state regime, pointing out that the NPs emission is governed by donor-acceptor (D-A) recombination mechanisms. Moreover, the increase of the corresponding lifetime values with the monitored wavelength further supports that the emission is governed by a recombination mechanism typical of a D-A pair attributed to an exceptionally broad inhomogeneous distribution of the emitting centers peculiar to silica-based NPs. These NPs exhibit the highest emission quantum yield value (0.15 ± 0.02) reported so far for organosilica biolabels without activator metals. Moreover, the emission spectra and the quantum yield values are quite stable over time showing no significant aging effects after exposure to the ambient environment for more than 1 year, stressing the potential of these NPs as metal-free biolabels.


Assuntos
Luminescência , Nanopartículas/química , Compostos de Organossilício/química , Compostos de Organossilício/síntese química , Tamanho da Partícula , Propriedades de Superfície
5.
Magn Reson Med ; 66(6): 1715-21, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21574179

RESUMO

A series of maghemite/polymer composite ferrofluids with variable magnetic core size, which show a good efficiency as MRI contrast agents, are presented. These ferrofluids are biocompatible and can be proposed as possible platforms for multifunctional biomedical applications, as they contain anchoring groups for biofunctionalization, can incorporate fluorescent dyes, and have shown low cellular toxicity. The magnetic properties of the ferrofluids have been determined by means of magnetization and ac susceptibility measurements as a function of temperature and frequency. The NMR dispersion profiles show that the low frequency behavior of the longitudinal relaxivity r(1) is well described by the heuristic model of (1)H nuclear relaxation induced by superparamagnetic nanoparticles proposed by Roch and co-workers. The contrast efficiency parameter, i.e., the nuclear transverse relaxivity r(2), for samples with d > 10 nm assumes values comparable with or better than the ones of commercial samples, the best results obtained in particles with the biggest magnetic core, d = 15 nm. The contrast efficiency results are confirmed by in vitro MRI experiments at ν = 8.5 MHz, thus allowing us to propose a set of optimal microstructural parameters for multifunctional ferrofluids to be used in MRI medical diagnosis.


Assuntos
Meios de Contraste/química , Compostos Férricos/química , Imageamento por Ressonância Magnética/métodos , Polímeros/química , Condutividade Elétrica , Campos Magnéticos , Teste de Materiais
6.
Acta Crystallogr C ; 67(Pt 11): m359-63, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22051953

RESUMO

The structure of the title complex, poly[dicaesium(I) hexaaquacobalt(II) [octaaquatetra-µ-citrato-hexacobalt(II)] dodecahydrate], {Cs(2)[Co(H(2)O)(6)][Co(6)(C(6)H(4)O(7))(4)(H(2)O)(8)]·12H(2)O}(n), at 100 (1) K is formed by layers of a square two-dimensional polymer composed of Co(II) citrate cubanes bridged by magnetically active six-coordinate Co(II) cations. The polymer has plane symmetry p4mm in the c-axis projection. The cubanes reside on sites of crystallographic symmetry 4, while the bridging Co(II) centres lie on twofold axes. The basic polymeric unit has a charge of 4-, balanced by two Cs(+) and a [Co(H(2)O)(6)](2+) (symmetry -4) cation, which lie in channels between the polymeric layers. Unligated water molecules, of which there are 12 per cubane, enter into an extended intralayer and layer-bridging hydrogen-bond pattern, which can be described in detail even though not all of the H atoms of the water molecules were located.

7.
Future Sci OA ; 5(1): FSO235, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30652014

RESUMO

AIM: To study the efficiency of multifunctional polymer-based superparamagnetic iron oxide nanoparticles (bioferrofluids) as a T2 magnetic resonance contrast agent and their uptake and toxicity in liver. MATERIALS & METHODS: Mice were intravenously injected with bioferrofluids and Endorem®. The magnetic resonance efficiency, uptake and in vivo toxicity were investigated by means of magnetic resonance imaging (MRI) and histological techniques. RESULTS: Bioferrofluids are a good T2 contrast agent with a higher r2/r1 ratio than Endorem. Bioferrofluids have a shorter blood circulation time and persist in liver for longer time period compared with Endorem. Both bioferrofluids and Endorem do not generate any noticeable histological lesions in liver over a period of 60 days post-injection. CONCLUSION: Our bioferrofluids are powerful diagnostic tool without any observed toxicity over a period of 60 days post-injection.

9.
Nanoscale ; 9(28): 9960-9972, 2017 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-28681874

RESUMO

At present, bioferrofluids are employed as powerful multifunctional tools for biomedical applications such as drug delivery, among others. The present study explores the cellular response evoked when bile-acid platinum derivatives are conjugated with bioferrofluids by testing the biological activity in osteosarcoma (MG-63) and T-cell leukemia (Jurkat) cells. The aim of this work is to evaluate the biocompatibility of a bile-acid platinum derivative conjugated with multi-functional polymer coated bioferrofluids by observing the effects on the protein expression profiles and in intracellular pathways of nanoparticle-stimulated cells. To this end, a mass spectrometry-based approach termed SILAC has been applied to determine in a high-throughput manner the key proteins involved in the cellular response process (including specific quantitatively identified proteins related to the vesicular transport, cellular structure, cell cycle, biosynthetic process, apoptosis and regulation of the cell cycle). Finally, biocompatibility was evaluated and validated by conventional strategies also (such as flow cytometry, MTT, etc.).


Assuntos
Ácidos e Sais Biliares/química , Nanopartículas/química , Compostos de Platina/farmacologia , Apoptose , Materiais Biocompatíveis , Ciclo Celular , Ensaios de Triagem em Larga Escala , Humanos , Ferro , Células Jurkat , Espectrometria de Massas , Polímeros , Proteômica , Transcriptoma
11.
Toxicol In Vitro ; 29(5): 962-75, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25891827

RESUMO

We are reporting the cytocompatibility and cellular fate of an iron oxide/polymer nanoplatform (IONP) in its most basic formulation, using both mesenchymal (vascular smooth muscle cells, VSMC), and epithelial (opossum kidney, OK) cells. The cytotoxicity and cell internalization of the nanoplatform has been evaluated in relation to time of exposure and concentration of different components. A series of samples with different iron oxide nanoparticle, sizes, hydrodynamic sizes and iron/polymer ratio have been examined. In all cases cytotoxicity is low, and it is mostly determined by the internalization rate, being higher in VSMC than in OK cells. The mean lethal dose has a very narrow threshold, and necrosis is the only cell death type. IONP uptake shows little incidence on oxidative stress, and inflammasome activation is only observed with the smaller IONP at high concentration. The internalization rate in VSMC is determined by the polymer concentration exclusively. In OK cells, internalization rate seems to increase with decreasing hydrodynamic size. Internalization occurs through clathrin-dependent endocytosis, as it is prevented by potassium depletion and chlorpromazine. IONP are directed and accumulated in lysosomes. Under IONP overload, lysosomal dysfunction would cause cell death using concentrations that are hardly achieved in vivo.


Assuntos
Compostos Férricos/toxicidade , Miócitos de Músculo Liso/efeitos dos fármacos , Nanopartículas/toxicidade , Polímeros/toxicidade , Animais , Aorta/citologia , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Endocitose , Lisossomos/metabolismo , Miócitos de Músculo Liso/metabolismo , Ratos
12.
ACS Nano ; 9(3): 3134-42, 2015 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-25693033

RESUMO

Whereas efficient and sensitive nanoheaters and nanothermometers are demanding tools in modern bio- and nanomedicine, joining both features in a single nanoparticle still remains a real challenge, despite the recent progress achieved, most of it within the last year. Here we demonstrate a successful realization of this challenge. The heating is magnetically induced, the temperature readout is optical, and the ratiometric thermometric probes are dual-emissive Eu(3+)/Tb(3+) lanthanide complexes. The low thermometer heat capacitance (0.021·K(-1)) and heater/thermometer resistance (1 K·W(-1)), the high temperature sensitivity (5.8%·K(-1) at 296 K) and uncertainty (0.5 K), the physiological working temperature range (295-315 K), the readout reproducibility (>99.5%), and the fast time response (0.250 s) make the heater/thermometer nanoplatform proposed here unique. Cells were incubated with the nanoparticles, and fluorescence microscopy permits the mapping of the intracellular local temperature using the pixel-by-pixel ratio of the Eu(3+)/Tb(3+) intensities. Time-resolved thermometry under an ac magnetic field evidences the failure of using macroscopic thermal parameters to describe heat diffusion at the nanoscale.


Assuntos
Temperatura Alta , Campos Magnéticos , Nanopartículas , Nanotecnologia/métodos , Termômetros , Animais , Linhagem Celular , Európio/química , Espaço Intracelular , Térbio/química , Fatores de Tempo
13.
Chem Commun (Camb) ; (6): 636-7, 2002 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-12120160

RESUMO

Mn(hfac)2 and Cu(hfac)2 form 1:1 complexes with 5-(4-[N-tert-butyl-N-aminoxyl]phenyl)pyrimidine that exhibit strong metal-nitroxide exchange; spin polarization models do not explain the antiferromagnetic exchange behavior between spin sites in these complexes.

14.
Chem Commun (Camb) ; (3): 252-3, 2002 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-12120390

RESUMO

The EPR spectroscopy, crystallography, and magnetic susceptibility of tetrakis(N-oxyl-2,2,6,6-tetramethylpiperidin-4-yl)silane and tetrakis(4-N-tert-butyl-N-aminoxylphenyl)silane show that silicon acts as a weak intramolecular exchange linker for polynitroxides, although both tetraradicals show onset of inter-spin exchange at reduced temperatures.

15.
Molecules ; 9(9): 771-81, 2004 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-18007476

RESUMO

The dithiadiazolyl radical p-NCC6F4C6F4CNSSN* (4) retains its monomeric nature in the solid state with molecules linked together into chains via supramolecular CN-S interactions. Variable temperature magnetic studies on 4 show that it behaves as a near-ideal Curie paramagnet (|theta| less than 0.1 K), indicating negligible intermolecular exchange. The effective magnetic moment (1.78 micro(B)) is temperature independent and in excellent agreement with the value expected for an S = 1/2 paramagnet with g = 2.01(1.74 micro(B)). The lack of exchange coupling between radicals is attributed to the absence of significant orbital overlap between radical centres.


Assuntos
Radicais Livres/química , Radicais Livres/síntese química , Magnetismo , Tiadiazóis/química , Tiadiazóis/síntese química , Cristalografia por Raios X , Modelos Moleculares , Temperatura
16.
Chem Commun (Camb) ; 50(78): 11437-9, 2014 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-25148363

RESUMO

I discuss here the contribution from J. S. Miller and co-workers concerning the discovery of ferromagnetism in an organometallic compound. The important peculiarities around this discovery, that the moments from p-electrons participate in magnetic ordering, strongly contributed to open the area of molecule-based magnetic materials as a new area of research.

17.
Dalton Trans ; 43(28): 10700-4, 2014 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-24901034

RESUMO

The neutral cluster [Mn(II)8(citrate)4(H2O)18] is formed by the [M4(citrate)4](8-) fragment, with an Mn4O4 cubane core, which bonds four peripheral aquomanganese units--two [Mn(H2O)4](2+) and two [Mn(H2O)5](2+)--through a total of six metal-ligand bonds, giving a discrete neutral compound. The compound presents a unique coordination mode in which the citrate cubane acts as a chelate to each of the two peripheral [Mn(H2O)4](2+) (tetra-aquo) units. A detailed analysis of the central and peripheral geometries is given in terms of the tetrahedral distortions of key structural features. A reversible dehydration-rehydration process has been observed in a polycrystalline sample of the complex, whose structure lacks pores or channels.

18.
J Inorg Biochem ; 131: 8-11, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24239907

RESUMO

This article explores the potential cytotoxic activity of bile-acid cisplatin derivatives like bisursodeoxycholate(ethylenediamine)platinum(II), PtU2, when conjugated with gold nanoparticles, being a promising alternative to cisplatin in the treatment of cancer due to their lower toxicity. For our purpose we analyzed the intracellular delivery ability of these compounds after conjugation with 20-nm gold nanoparticles (PtU2-AuNPs) in the MG63 (osteosarcoma) cell line. Same platinum uptake after incubation with PtU2 and PtU2-AuNPs-derivatives is associated with a higher cytotoxic activity in case of the platinum-gold nanoparticle conjugate, the overall IC50 of PtU2 being reduced more than 10 fold for these new conjugates. When conjugated with gold nanoparticles, this bile-acid derivative is more efficient than the platinum compound alone in terms of their cytotoxic activity.


Assuntos
Ácidos e Sais Biliares/química , Portadores de Fármacos/farmacologia , Nanopartículas Metálicas/química , Compostos Organoplatínicos/química , Compostos Organoplatínicos/farmacologia , Antineoplásicos/administração & dosagem , Antineoplásicos/química , Antineoplásicos/farmacologia , Neoplasias Ósseas/tratamento farmacológico , Neoplasias Ósseas/patologia , Linhagem Celular Tumoral , Cisplatino/análogos & derivados , Portadores de Fármacos/administração & dosagem , Portadores de Fármacos/química , Sistemas de Liberação de Medicamentos/métodos , Ouro , Humanos , Concentração Inibidora 50 , Osteossarcoma/tratamento farmacológico , Osteossarcoma/patologia
20.
Nanoscale ; 5(16): 7229-33, 2013 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-23831769

RESUMO

Ferrofluids and dry magnetic particles are two separate classes of magnetic materials with specific niche applications, mainly due to their distinct viscosity and interparticle distances. For practical applications, the stability of these two properties is highly desirable but hard to achieve. Conceptually, a possible solution to this problem would be encapsulating the magnetic particles but keeping them free to rotate inside a capsule with constant interparticle distances and thus shielded from changes in the viscosity of the surrounding media. Here we present an example of such materials by the encapsulation of magnetic ferrofluids into highly hydrophobic silica, leading to the formation of dry ferrofluids, i.e., a material behaving macroscopically as a dry powder but locally as a ferrofluid where magnetic nanoparticles are free to rotate in the liquid.

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