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1.
J Vis Exp ; (136)2018 06 24.
Artigo em Inglês | MEDLINE | ID: mdl-29985356

RESUMO

This video presents the use of transmission electron microscopy with energy dispersive X-ray microanalysis (TEM-EDX) to compare the state of minerals in vesicles released by two human bone cell lines: hFOB 1.19 and Saos-2. These cell lines, after treatment with ascorbic acid (AA) and ß-glycerophosphate (ß-GP), undergo complete osteogenic transdifferentiation from proliferation to mineralization and produce matrix vesicles (MVs) that trigger apatite nucleation in the extracellular matrix (ECM). Based on Alizarin Red-S (AR-S) staining and analysis of the composition of minerals in cell lysates using ultraviolet (UV) light or in vesicles using TEM imaging followed by EDX quantitation and ion mapping, we can infer that osteosarcoma Saos-2 and osteoblastic hFOB 1.19 cells reveal distinct mineralization profiles. Saos-2 cells mineralize more efficiently than hFOB 1.19 cells and produce larger mineral deposits that are not visible under UV light but are similar to hydroxyapatite (HA) in that they have more Ca and F substitutions. The results obtained using these techniques allow us to conclude that the process of mineralization differs depending on the cell type. We propose that, at the cellular level, the origin and properties of vesicles predetermine the type of minerals.


Assuntos
Microanálise por Sonda Eletrônica/métodos , Microscopia Eletrônica de Transmissão/métodos , Minerais/metabolismo , Humanos , Minerais/análise
2.
Eur J Histochem ; 62(1): 2841, 2018 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-29569878

RESUMO

The Energy Dispersive X-ray (EDX) microanalysis is a technique of elemental analysis associated to electron microscopy based on the generation of characteristic Xrays that reveals the presence of elements present in the specimens. The EDX microanalysis is used in different biomedical fields by many researchers and clinicians. Nevertheless, most of the scientific community is not fully aware of its possible applications. The spectrum of EDX microanalysis contains both semi-qualitative and semi-quantitative information. EDX technique is made useful in the study of drugs, such as in the study of drugs delivery in which the EDX is an important tool to detect nanoparticles (generally, used to improve the therapeutic performance of some chemotherapeutic agents). EDX is also used in the study of environmental pollution and in the characterization of mineral bioaccumulated in the tissues. In conclusion, the EDX can be considered as a useful tool in all works that require element determination, endogenous or exogenous, in the tissue, cell or any other sample.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/química , Microanálise por Sonda Eletrônica/métodos , Metais Pesados/análise , Pesquisa Biomédica , Poluentes Ambientais/química , Humanos , Metais Pesados/química
3.
Ultrastruct Pathol ; 40(3): 126-33, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26934117

RESUMO

There has been considerable interest in the exposure doses that contribute to the various asbestos-associated diseases. Epidemiological studies have shown important differences in the contributions of the various fiber types to asbestos-related diseases, with the amphiboles showing a greater degree of potency as compared to chrysotile. However, epidemiological studies have occasionally provided misleading results. Over the past several decades, there have been several examples where fiber analysis using electron microscopy produced unexpected results which were important to our understanding of disease-exposure relationships. It is the purpose of this article to summarize these fiber analysis vignettes.


Assuntos
Amianto/análise , Asbestose/diagnóstico , Microanálise por Sonda Eletrônica/métodos , Humanos , Mesotelioma/etiologia
4.
Vestn Ross Akad Med Nauk ; (3): 334-40, 2015.
Artigo em Russo | MEDLINE | ID: mdl-26495722

RESUMO

BACKGROUND: Non-drug correction of reparative bone tissue regeneration in different pathological states - one of the most actual problems of modern medicine. OBJECTIVE: Our aim was to conduct morphological analysis of the influence of electromagnetic radiation of ultra-high frequency and low intensity on reparative osteogenesis and angiogenesis in fracture treatment under transosseous osteosynthesis. METHODS: A controlled nonrandomized study was carried out. In the experiment conducted on rats we modeled tibial fracture with reposition and fixation of the bone fragments both in control and experimental groups. In the animals of the experimental group the fracture zone was exposed to low intensity electromagnetic radiation of ultra-high frequency. Exposure simulation was performed in the control group. The operated bones were examined using radiography, light and electronic microscopy, X-ray electronic probe microanalysis. RESULTS: It has been established that electromagnetic radiation of ultra-high frequency sessions in fracture treatment stimulate secretory activity and degranulation of mast cells, produce microcirculatory bed vascular permeability increase, endotheliocyte migration phenotype expression, provide endovascular endothelial outgrowth formation, activate reparative osteogenesis and angiogenesis while fracture reparation becomes the one of the primary type. The full periosteal, intermediary and intraosteal bone union was defined in 28 days. CONCLUSION: Among the therapeutic benefits of electromagnetic radiation of ultra-high frequency in fracture treatment we can detect mast cell secretorv activity stimulation and endovascular anziozenesis activation.


Assuntos
Regeneração Óssea/efeitos da radiação , Osso e Ossos , Fraturas Ósseas/terapia , Neovascularização Fisiológica/efeitos da radiação , Osteogênese/efeitos da radiação , Terapia por Radiofrequência , Animais , Osso e Ossos/irrigação sanguínea , Osso e Ossos/efeitos da radiação , Modelos Animais de Doenças , Radiação Eletromagnética , Microanálise por Sonda Eletrônica/métodos , Fixação Interna de Fraturas/reabilitação , Microscopia Eletrônica/métodos , Ratos , Resultado do Tratamento
5.
Vestn Oftalmol ; 131(4): 74-78, 2015.
Artigo em Russo | MEDLINE | ID: mdl-26489123

RESUMO

AIM: to perform chemical microanalysis of mineral deposits on the surface of explanted hydrophilic acrylic intraocular lenses (IOL). MATERIAL AND METHODS: Two soft IOLs made of hydrophilic acryl (one, however, hydrophobic surface coated) and explanted 3 and 6 years after implantation were examined by scanning electron microscopy (EVO LS10, "Karl Zeiss", Germany). Chemical composition of the lens surface was studied using an energy-dispersive spectrometer (EDS X-Max50, Oxford, Great Britain). RESULTS: Chemical microanalysis allowed identification of the deposits, which turned out to be non-stoichiometric hydroxylapatite (also, hydroxyapatite (HA)) crystals with zinc impurity (up to 1.4%weight). CONCLUSION: The two samples represent two stages of a single process. The early stage is associated with newly formed HA crystals that are unable to cause any significant changes to the lens surface. However, as spherocrystals grow, they exert a crystallization effort that moves their growth centers apart with subsequent lens rupture and deformation. Crystal morphology undergoes dynamic changes: while primary (newly formed) crystals are sheaf-like, mature are spheres. A growing HA is non-stoichiometric. Zinc abundance accounts for appearance of its separate mineral phase. Hydrophilic properties of acrylic polymer determine its high affinity for HA crystals. Hydrophobic coating (sample no.1) does not completely prevent lens opacification due to mineral deposits on its surface.


Assuntos
Calcinose , Remoção de Dispositivo , Hidrogel de Polietilenoglicol-Dimetacrilato , Implante de Lente Intraocular/efeitos adversos , Falha de Prótese/etiologia , Materiais Biocompatíveis/efeitos adversos , Materiais Biocompatíveis/química , Calcinose/diagnóstico , Calcinose/etiologia , Microanálise por Sonda Eletrônica/métodos , Humanos , Hidrogel de Polietilenoglicol-Dimetacrilato/efeitos adversos , Hidrogel de Polietilenoglicol-Dimetacrilato/química , Lentes Intraoculares , Microscopia Eletrônica de Varredura/métodos , Reoperação/métodos , Propriedades de Superfície , Acuidade Visual
6.
Micron ; 79: 16-23, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26283070

RESUMO

Retinal pigment epithelial cells as well as choroidal melanocytes (CM) possess melanin granules. The former show clear, age-related changes (formation of lipofuscin granules with a concomitant decrease in melanin content); however, data on changes in the CM with aging are fairly limited. We examined CM in human macular and mid-peripheral areas by light- and transmission electron microscopy in 50-94 year-old donor eyes (N=12). Unlike in the choroid of lower ages, the melanocytes from aging choroid (>75 years) showed partial fusion of about 8-15 melanosomes, forming rosettes-like structures. Besides, there was evidence of emptiness in cytoplasm caused by the loss of melanosomes in aged CM, as was confirmed by quantification in macular part of choroid. In advanced aged eyes (85-94-year-old), the CM possessed many lipid droplets as well as irregular lipofuscin granules, the latter had a tendency to fuse with melanosomes, as happens in aged retinal pigment epithelium. Macrophages in their cytoplasm contained abundant irregular as well as clumped melanosomes of variable size, suggesting that damaged granules/melanocytes are cleared by these phagocytes. These obvious changes in the CM are likely to make the choroid prone to damage by visible light.


Assuntos
Corioide/ultraestrutura , Melanócitos/ultraestrutura , Microscopia Eletrônica de Transmissão/métodos , Idoso , Idoso de 80 Anos ou mais , Envelhecimento/patologia , Corioide/citologia , Microanálise por Sonda Eletrônica/métodos , Humanos , Lipofuscina , Macrófagos/citologia , Macrófagos/ultraestrutura , Melaninas , Melanossomas/ultraestrutura , Pessoa de Meia-Idade , Epitélio Pigmentado da Retina/ultraestrutura
7.
Physiol Plant ; 152(4): 738-48, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24813633

RESUMO

Grafting onto salt-tolerant pumpkin rootstock can increase cucumber salt tolerance. Previous studies have suggested that this can be attributed to pumpkin roots with higher capacity to limit the transport of Na(+) to the shoot than cucumber roots. However, the mechanism remains unclear. This study investigated the transport of Na(+) in salt-tolerant pumpkin and salt-sensitive cucumber plants under high (200 mM) or moderate (90 mM) NaCl stress. Scanning ion-selective electrode technique showed that pumpkin roots exhibited a higher capacity to extrude Na(+), and a correspondingly increased H(+) influx under 200 or 90 mM NaCl stress. The 200 mM NaCl induced Na(+)/H(+) exchange in the root was inhibited by amiloride (a Na(+)/H(+) antiporter inhibitor) or vanadate [a plasma membrane (PM) H(+) -ATPase inhibitor], indicating that Na(+) exclusion in salt stressed pumpkin and cucumber roots was the result of an active Na(+)/H(+) antiporter across the PM, and the Na(+)/H(+) antiporter system in salt stressed pumpkin roots was sufficient to exclude Na(+) X-ray microanalysis showed higher Na(+) in the cortex, but lower Na(+) in the stele of pumpkin roots than that in cucumber roots under 90 mM NaCl stress, suggesting that the highly vacuolated root cortical cells of pumpkin roots could sequester more Na(+), limit the radial transport of Na(+) to the stele and thus restrict the transport of Na(+) to the shoot. These results provide direct evidence for pumpkin roots with higher capacity to limit the transport of Na(+) to the shoot than cucumber roots.


Assuntos
Cucumis sativus/fisiologia , Cucurbita/fisiologia , Microanálise por Sonda Eletrônica/métodos , Proteínas de Plantas/metabolismo , Sódio/metabolismo , Transporte Biológico , Membrana Celular/metabolismo , Cucumis sativus/efeitos dos fármacos , Cucurbita/efeitos dos fármacos , Eletrodos Seletivos de Íons , Epiderme Vegetal/efeitos dos fármacos , Epiderme Vegetal/fisiologia , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/fisiologia , Brotos de Planta/efeitos dos fármacos , Brotos de Planta/fisiologia , Potássio/metabolismo , ATPases Translocadoras de Prótons/metabolismo , Tolerância ao Sal , Cloreto de Sódio/farmacologia , Trocadores de Sódio-Hidrogênio/metabolismo , Estresse Fisiológico
8.
Respir Investig ; 52(1): 5-13, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24388365

RESUMO

Occupational and environmental lung diseases are a group of pulmonary disorders caused by inhalation of harmful particles, mists, vapors or gases. Mineralogical analysis is not generally required in the diagnosis of most cases of these diseases. Apart from minerals that are encountered rarely or only in specific occupations, small quantities of mineral dusts are present in the healthy lung. As such when mineralogical analysis is required, quantitative or semi-quantitative methods must be employed. An electron probe microanalyzer with wavelength dispersive spectrometer (EPMA-WDS) enables analysis of human lung tissue for deposits of elements by both qualitative and semi-quantitative methods. Since 1993, we have analyzed 162 cases of suspected occupational and environmental lung diseases using an EPMA-WDS. Our institute has been accepting online requests for elemental analysis of lung tissue samples by EPMA-WDS since January 2011. Hard metal lung disease is an occupational interstitial lung disease that primarily affects workers exposed to the dust of tungsten carbide. The characteristic pathological findings of the disease are giant cell interstitial pneumonia (GIP) with centrilobular fibrosis, surrounded by mild alveolitis with giant cells within the alveolar space. EPMA-WDS analysis of biopsied lung tissue from patients with GIP has demonstrated that tungsten and/or cobalt is distributed in the giant cells and centrilobular fibrosing lesion in GIP. Pneumoconiosis, caused by amorphous silica, and acute interstitial pneumonia, associated with the giant tsunami, were also elementally analyzed by EPMA-WDS. The results suggest that commonly found elements, such as silicon, aluminum, and iron, may cause occupational and environmental lung diseases.


Assuntos
Microanálise por Sonda Eletrônica/instrumentação , Exposição Ambiental/efeitos adversos , Pulmão/metabolismo , Metais/efeitos adversos , Metais/análise , Doenças Profissionais/diagnóstico , Doenças Profissionais/etiologia , Exposição Ocupacional/efeitos adversos , Pneumoconiose/diagnóstico , Pneumoconiose/etiologia , Cobalto/efeitos adversos , Cobalto/análise , Poeira , Microanálise por Sonda Eletrônica/métodos , Humanos , Pulmão/patologia , Tamanho da Partícula , Compostos de Tungstênio/efeitos adversos , Compostos de Tungstênio/análise
9.
Environ Sci Pollut Res Int ; 21(6): 4023-31, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24194417

RESUMO

The SEM EDX backscattered electron (BSE) atomic number contrast has been largely used in this work, in combination with conventional secondary electron microanalysis, to investigate the presence of metal particles in airborne particulate collected at three sites (industrial, residential, and rural background) in the Po Valley (Italy). Individual particle x-ray microanalysis was used for this aim. In many cases, the presence of metal particles was not evident by secondary electron imaging and it was instead revealed by BSE detection. Metal particles were observed either as isolated (not clustered to other particles), or gathered together (homogeneous clusters). In addition, the BSE microanalysis put on evidence two main types of association of metals to other particulate components: heterogeneous clusters and metals embedded or enclosed in other materials. In this study, the first association (heterogeneous clusters) was observed mostly between Fe-bearing metallic particles and soot aggregates (or other carbonaceous particles) and it was found in the particulate matter (PM) of all studied sites. The second association, conversely, seems to be characterized by more selective relationships between composition/size of metal particles and type of other particulate components. These associations could be evidenced only when using the BSE Z-contrast and mainly concern three cases: (1) unusual silicate-carbonate mixed aggregates were observed at the industrial site only. In these aggregates, embedded Mn, Cr, Co, Bi, W, and Zr fine particles were selectively observed. (2) Ni and V rich ultrafine particles were only observed as embedded particles in the surface structure of carbon cenospheres. (3) Pb or Pb-Zn bearing fine and ultrafine particles were largely detected only in oxygenated organic aerosols in the ultrafine PM.


Assuntos
Aerossóis/análise , Poluentes Atmosféricos/análise , Metais/análise , Elementos de Transição/análise , Aerossóis/química , Poluentes Atmosféricos/química , Carbono/análise , Carbono/química , Microanálise por Sonda Eletrônica/métodos , Elétrons , Monitoramento Ambiental/métodos , Itália , Metais/química , Microscopia Eletrônica de Varredura , Tamanho da Partícula , Material Particulado/química , Fuligem/análise , Fuligem/química , Elementos de Transição/química
10.
Anal Chem ; 86(1): 664-70, 2014 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-24283887

RESUMO

In this paper we report on the fabrication and testing of a novel concept of sealed electrochemical microcell for in situ soft X-ray microspectroscopy in transmission, dedicated for nonvacuum compatible electrolytes. The microcell, fabricated using ultraviolet lithography, at variance with previous versions of electrochemical wet cells, that featured an optical window glued on top of the electrode system and a very limited electrolyte volume, the device presented here is a single solid block based around a microfabricated channel with fixed optical windows and apt for microfluidic work. Moreover, this cell allows to employ an advanced electrodic geometry developed in our group - so far used only in open electrochemical cells for work with vacuum-compatible electrolytes - also with low-vapor pressure liquids, possibly saturated with the required gases. The cell optimal electrode design allows three-electrode electrochemical control typical of traditional electrochemical experiments. The first electrochemical experiments with this new cell explore the electrochemical growth of a Co-polypyrrole, a composite electrocatalyst material with promising performance to replace the expensive Pt catalyst in fuel-cell oxygen electrodes. Morphological and chemical-state distributions of Co codeposited with polypyrrole has been followed as a function of time and position, yielding unprecedented information on the processes relevant to the synthesis of this catalyst.


Assuntos
Técnicas Eletroquímicas/métodos , Microanálise por Sonda Eletrônica/métodos , Galvanoplastia/métodos , Oxigênio/análise , Platina , Polímeros/análise , Pirróis/análise , Catálise , Oxigênio/metabolismo , Polímeros/metabolismo , Pirróis/metabolismo
11.
J Nanosci Nanotechnol ; 13(8): 5807-10, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23882839

RESUMO

In this study, hydroxyapatite (HA) was coated on anodized titanium (Ti) surfaces through radio frequency magnetron sputtering in order to improve biological response of the titanium surface. All the samples were blasted with resorbable blasting media (RBM). RBM-blasted Ti surface, anodized Ti surface, as-sputtered HA coating on the anodized Ti surface, and heat-treated HA coating on the anodized Ti surface were prepared. The samples were characterized using scanning electron microscopy and X-ray photoemission spectroscopy, and biologic responses were evaluated. The top of the TiO2 nanotubes was not closed by HA particles when the coating time is less than 15 minutes. It was demonstrated that the heat-treated HA was well-crystallized and this enhanced the cell attachment of the anodized Ti surface.


Assuntos
Materiais Revestidos Biocompatíveis/química , Durapatita/química , Magnetismo , Nanotecnologia/métodos , Células 3T3 , Animais , Adesão Celular , Meios de Cultura , Microanálise por Sonda Eletrônica/métodos , Camundongos , Nanotubos/química , Osteoblastos/citologia , Propriedades de Superfície , Titânio/química
12.
Biofizika ; 57(5): 827-31, 2012.
Artigo em Russo | MEDLINE | ID: mdl-23136775

RESUMO

In the given investigation contents of potassium and its physiological analog, rubidium, are determined in cardiomyocyte. Applying Electron Probe Microanalysis (EPMA), cytoplasmic concentrations of elements (K, Rb) are measured. The data obtained exhibit that for initial acute ischemia phase the active transport is involved in the uptake of rubidium which competes with potassium entry in cardiac myocell. Then, deep deenergization leads to the intracellular potassium depletion and rubidium retention. This suggests that Rb+ is physiologically not complete analog for K+. Results of combined perfusion with and without rubidium allow us to hypothesize the appearance of cascade of ionic transports to compensate acute ischemic disturbances following the oxygen and substrate deficiency.


Assuntos
Microanálise por Sonda Eletrônica/métodos , Isquemia Miocárdica/metabolismo , Miócitos Cardíacos/metabolismo , Potássio/metabolismo , Rubídio/metabolismo , Doença Aguda , Animais , Citoplasma/metabolismo , Modelos Animais de Doenças , Transporte de Íons , Isquemia Miocárdica/patologia , Miócitos Cardíacos/patologia , Técnicas de Cultura de Órgãos , Oxigênio/metabolismo , Perfusão , Ratos , Ratos Wistar , ATPase Trocadora de Sódio-Potássio/metabolismo
13.
J. appl. oral sci ; 20(4): 478-485, July-Aug. 2012. ilus
Artigo em Inglês | LILACS | ID: lil-650627

RESUMO

OBJECTIVE: The objective of this study was to investigate the applicability of micro-analytical methods with high spatial resolution to the characterization of the composition and corrosion behavior of two bracket systems. MATERIAL AND METHODS: The surfaces of six nickel-free brackets and six nickel-containing brackets were examined for signs of corrosion and qualitative surface analysis using an electron probe microanalyzer (EPMA), prior to bonding to patient's tooth surfaces and four months after clinical use. The surfaces were characterized qualitatively by secondary electron (SE) images and back scattered electron (BSE) images in both compositional and topographical mode. Qualitative and quantitative wavelength-dispersive analyses were performed for different elements, and by utilizing qualitative analysis the relative concentration of selected elements was mapped two-dimensionally. The absolute concentration of the elements was determined in specially prepared brackets by quantitative analysis using pure element standards for calibration and calculating correction-factors (ZAF). RESULTS: Clear differences were observed between the different bracket types. The nickel-containing stainless steel brackets consist of two separate pieces joined by a brazing alloy. Compositional analysis revealed two different alloy compositions, and reaction zones on both sides of the brazing alloy. The nickel-free bracket was a single piece with only slight variation in element concentration, but had a significantly rougher surface. After clinical use, no corrosive phenomena were detectable with the methods applied. Traces of intraoral wear at the contact areas between the bracket slot and the arch wire were verified. CONCLUSION: Electron probe microanalysis is a valuable tool for the characterization of element distribution and quantitative analysis for corrosion studies.


Assuntos
Adolescente , Humanos , Materiais Dentários/química , Microanálise por Sonda Eletrônica/métodos , Níquel/química , Braquetes Ortodônticos , Aço Inoxidável/química , Corrosão , Teste de Materiais , Reprodutibilidade dos Testes , Propriedades de Superfície , Fatores de Tempo
14.
Osteoarthritis Cartilage ; 20(7): 694-702, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22498029

RESUMO

OBJECTIVE: To employ elemental Strontium as a tracer of bone turnover, in the presence (or absence) of the bisphosphonate drug Alendronate, in order to spatially map osteophytogenesis and other bone turnover in rats developing post-traumatic secondary osteoarthritis (PTOA). METHODS: PTOA was induced in rats by medial meniscectomy surgery. We utilized in-vivo microfocal computed tomography (CT) to follow bony adaptations in groups for 8 weeks after surgery, either with or without alendronate treatment. Electron probe microanalysis (EPMA) was used to detect Strontium incorporation in mineralizing tissues. Histologic studies were conducted on the same samples using Safranin-O/fast green and Tetrachrome staining of decalcified sections to examine articular cartilage health and osteophyte formation at the sites of elemental Strontium deposition. RESULTS: EPMA revealed uniform incorporation of Strontium over actively remodeling trabecular surfaces in normal control rats. That pattern was significantly altered after meniscectomy surgery resulting in greater Strontium signal at the developing osteophyte margins. Alendronate treatment inhibited osteophyte development by 40% and 51% quantified by micro-CT volumetric measurements at 4 and 8 weeks after surgery, respectively. Osteophytes in the alendronate group were more cartilaginous in composition [i.e., lower bone mineral density (BMD)] compared to the untreated group. Histological analysis confirmed the osteophyte inhibitory effect of alendronate, and also verified reduced degeneration of the articular cartilage compared to untreated rats. CONCLUSION: Our study confirmed that alendronate administration will reduce osteophyte formation in a rat model of post-traumatic osteoarthritis, partially through the inhibition of secondary remodeling of osteophytes. Our study is the first to employ elemental Strontium as a tracer of bone turnover in the pathogenesis of osteoarthritis and to assess the efficacy of bisphosphonate antiresorptive drug interventions on osteophytogenesis.


Assuntos
Alendronato/uso terapêutico , Artrite Experimental/prevenção & controle , Conservadores da Densidade Óssea/uso terapêutico , Osteoartrite/prevenção & controle , Osteófito/prevenção & controle , Animais , Artrite Experimental/diagnóstico por imagem , Artrite Experimental/etiologia , Avaliação Pré-Clínica de Medicamentos/métodos , Microanálise por Sonda Eletrônica/métodos , Feminino , Compostos Organometálicos , Osteoartrite/diagnóstico por imagem , Osteoartrite/etiologia , Osteogênese/efeitos dos fármacos , Osteófito/diagnóstico por imagem , Osteófito/etiologia , Ratos , Ratos Sprague-Dawley , Tiofenos , Lesões do Menisco Tibial , Microtomografia por Raio-X/métodos
15.
J Microencapsul ; 29(3): 242-9, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22214322

RESUMO

In this article, an amphiphilic graft copolymer composed of poly(2-methacryloyloxyethyl phosphorylcholine) (PMPC) as the hydrophilic backbone, poly(L-lactic acid) (PLA) as the hydrophobic side-chains and polyethylene glycol (PEG) as the spacer was synthesized. Transmission electron microscopy revealed that the graft copolymer could self-assemble into hollow microcapsules when dialyzed in aqueous solution and particle sizes ranged from 200 to 300 nm, while the graft copolymer formed core-shell microspheres with the absence of PEG spacer. X-ray photoelectron microscope showed that MPC polymers were located at the surface of the microcapsules. The amounts of adsorbed bovine serum albumin and Fg on the microcapsules were significantly decreased than that on the conventional PLA particles (74% and 60%, respectively), well indicating the anti-adhesive property of the microcapsules. Paclitaxel was chosen as a prototype anticancer drug for the encapsulation and release studies, the results showed that the drug encapsulation efficiency was 89.3 ± 1.2% and the microcapsules exhibited controlled release behaviour.


Assuntos
Cápsulas/química , Portadores de Fármacos/química , Ácido Láctico/química , Fosforilcolina/análogos & derivados , Polietilenoglicóis/química , Polímeros/química , Adsorção , Animais , Antineoplásicos/administração & dosagem , Materiais Biocompatíveis/química , Biomimética , Bovinos , Sistemas de Liberação de Medicamentos , Microanálise por Sonda Eletrônica/métodos , Humanos , Metacrilatos , Paclitaxel/administração & dosagem , Fosforilcolina/química , Poliésteres , Ácidos Polimetacrílicos , Soroalbumina Bovina/química
16.
J Neurotrauma ; 29(7): 1530-8, 2012 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-22087764

RESUMO

Osteopontin (OPN), an adhesive glycoprotein, has recently been proposed to act as an opsonin that facilitates phagocytosis of neuronal debris by macrophages in the ischemic brain. The present study was designed to elucidate the process whereby OPN binds to neuronal cell debris in a rat model of ischemic stroke. Significant co-localization of the OPN protein and calcium deposits in the ischemic core were observed by combining alizarin red staining and OPN immunohistochemistry. In addition, electron microscopy (EM) using the osmium/potassium dichromate method revealed that electron-dense precipitates, typical of calcium deposits, were localized mainly along the periphery of putative degenerating neurites. This topical pattern of calcium precipitates resembled the distribution of OPN as detected by immunogold-silver EM. Combining immunogold-silver EM and electron probe microanalysis further demonstrated that the OPN protein was localized at the periphery of cell debris or degenerating neurites, corresponding with locally higher concentrations of calcium and phosphorus, and that the relative magnitude of OPN accumulation was comparable to that of calcium and phosphorus. These data suggest that calcium precipitation provides a matrix for the binding of the OPN protein within the debris or degenerating neurites induced by ischemic injury. Therefore, OPN binding to calcium deposits may be involved in phagocytosis of such debris, and may participate in the regulation of ectopic calcification in the ischemic brain.


Assuntos
Isquemia Encefálica/metabolismo , Encéfalo/metabolismo , Cálcio/metabolismo , Osteopontina/metabolismo , Animais , Apoptose/fisiologia , Encéfalo/patologia , Isquemia Encefálica/patologia , Calcinose/metabolismo , Calcinose/patologia , Modelos Animais de Doenças , Microanálise por Sonda Eletrônica/métodos , Masculino , Neurônios/metabolismo , Neurônios/patologia , Neurônios/ultraestrutura , Ratos , Ratos Sprague-Dawley , Acidente Vascular Cerebral/metabolismo , Acidente Vascular Cerebral/patologia
17.
J Mater Sci Mater Med ; 22(4): 819-27, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21360121

RESUMO

Gly-Arg-Gly-Asp-Ser-Pro (GRGDSP) peptide has frequently been used in the biomedical materials to enhance adhesion and proliferation of cells. In this work, we modified the nontoxic biodegradable waterborne polyurethanes (WBPU) with GRGDSP peptide and fabricated 3-D porous scaffold with the modified WBPU to investigate the effect of the immobilized GRGDSP peptide on human umbilical vein endothelial cells (HUVECs) adhesion and proliferation. A facile and reliable approach was first developed to quantitative grafting of GRGDSP onto the WBPU molecular backbone using ethylene glycol diglycidyl ether (EX810) as a connector. Then 3-D porous WBPU scaffolds with various GRGDSP content were fabricated by freeze-drying the emulsion. In both of the HUVECs adhesion and proliferation tests, enhanced cell performance was observed on the GRGDSP grafted scaffolds compared with the unmodified scaffolds and the tissue culture plate (TCP). The adhesion rate and proliferation rate increased with the increase of GRGDSP content in the scaffold and reached a maximum with peptide concentration of 0.85 µmol/g based on the weight of the polyurethanes. These results illustrate the necessity of the effective control of the GRGDSP content in the modified WBPU and support the potential utility of these 3-D porous modified WBPU scaffolds in the soft tissue engineering to guide cell adhesion, proliferation and tissue regeneration.


Assuntos
Peptídeos/química , Poliuretanos/química , Engenharia Tecidual/métodos , Materiais Biocompatíveis/química , Adesão Celular , Proliferação de Células , Sobrevivência Celular , Células Cultivadas , Microanálise por Sonda Eletrônica/métodos , Endotélio Vascular/citologia , Humanos , Porosidade , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Fatores de Tempo , Veias Umbilicais/citologia , Água/química
18.
Histol Histopathol ; 26(3): 333-42, 2011 03.
Artigo em Inglês | MEDLINE | ID: mdl-21210346

RESUMO

Several lines of evidence suggest that cisplatin-induced cell death is not always the result of apoptosis. A distinctive feature between apoptosis and necrosis is the alteration in cell volume regulation and ion homeostasis. Here we analyzed the changes in intracellular element content during cell death induced by exposure to therapeutic concentrations of cisplatin in the PC12 cell line. To quantitate Na, Cl and K content, electron probe X-ray microanalysis (EPXMA) was performed in whole freeze-dried cells. We also traced the alterations in morphological features with fluorescence and transmission electron microscopy. EPXMA demonstrated progressive derangement of the absolute intracellular Na, Cl and K contents. Cisplatin-treated cells showed two microanalytical patterns: 1) cells with alterations in elemental content typical of apoptosis, i.e., an increase in intracellular Na and a decrease in intracellular Cl and K, and 2) cells characterized by an increase in Na content and a decrease in K content, with no changes in Cl content. This intracellular profile for Na, Cl, and K was not typical of necrosis or apoptosis. Morphological analysis revealed two cellular phenotypes: 1) cells characterized by a phenotype typical of apoptosis, and 2) cells characterized by a hybrid phenotype combining variable features of apoptosis and necrosis. Taken together, our findings suggest that therapeutic concentrations of cisplatin may cause a hybrid type of cell death characterized by concurrent apoptosis and necrosis in the same individual PC12 cell.


Assuntos
Antineoplásicos/toxicidade , Cisplatino/toxicidade , Microanálise por Sonda Eletrônica/métodos , Algoritmos , Animais , Morte Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Cloretos/metabolismo , Liofilização , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Células PC12 , Potássio/metabolismo , Ratos , Sódio/metabolismo
19.
Ultramicroscopy ; 111(7): 768-76, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21177037

RESUMO

Transient optical gratings for detecting ultrafast signals are routine for temporally resolved photochemical investigations. Many processes can contribute to the formation of such gratings; we indicate use of optically scattering centres that can be formed with highly variable latencies in different materials and devices using ionising radiation. Coherent light scattered by these centres can form the short-wavelength-to-optical-wavelength, incoherent-to-coherent basis of a Bragg X-ray microscope, with inherent scope for optical phasing. Depending on the dynamics of the medium chosen, the way is open to both ultrafast pulsed and integrating measurements. For experiments employing brief pulses, we discuss high-dynamic-range short-wavelength diffraction measurements with real-time optical reconstructions. Applications to optical real-time X-ray phase-retrieval are considered.


Assuntos
Microanálise por Sonda Eletrônica/métodos , Microscopia/métodos , Radiação Ionizante , Processamento de Imagem Assistida por Computador/métodos , Fótons , Espectrometria por Raios X/métodos , Difração de Raios X/métodos , Raios X
20.
Methods Mol Biol ; 697: 93-9, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21116957

RESUMO

Energy Dispersive X-ray (EDX) microanalysis is a technique used for identification of the elemental composition of a specimen. The detection of nanoparticles in tissue is a common problem of biodistribution and toxicity studies. High-resolution transmission electron microscopy (TEM) can be employed to detect nanoparticles based on morphology; however, TEM alone cannot conclusively identify nanoparticles. Indeed, micrographs are often ambiguous due to particle aggregation, contamination, or morphology change after cellular uptake. EDX can be used to confirm the composition and distribution of the nanoparticles through spectrum and elemental mapping. This protocol outlines the procedures for compositional identification of nanoparticles using an EDX spectrometer incorporated into a scanning electron microscopy (SEM) system. This protocol outlines sample preparation, EDX spectrum acquisition, elemental peak analysis and spectral mapping acquisition.


Assuntos
Microscopia Eletrônica de Varredura/métodos , Microtomia , Nanopartículas/química , Animais , Carbono/análise , Carbono/química , Células Cultivadas , Microanálise por Sonda Eletrônica/métodos , Ouro/análise , Ouro/química , Pulmão/química , Pulmão/citologia , Pulmão/ultraestrutura , Macrófagos/química , Macrófagos/ultraestrutura , Microscopia Eletrônica de Transmissão , Nanopartículas/análise , Oxigênio/análise , Oxigênio/química , Roedores/anatomia & histologia , Espectrometria por Raios X , Técnicas de Cultura de Tecidos , Titânio/análise , Titânio/química
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