RESUMEN
GeSn alloys with Sn contents of 8.4 % and 10.7 % are grown pseudomorphically on Ge buffers on Si (001) substrates. The alloys as-grown are compressively strained, and therefore indirect bandgap. Undercut GeSn on Ge microdisk structures are fabricated and strained by silicon nitride stressor layers, which leads to tensile strain in the alloys, and direct bandgap photoluminescence in the 3-5 µm gas sensing window of the electromagnetic spectrum. The use of pseudomorphic layers and external stress mitigates the need for plastic deformation to obtain direct bandgap alloys. It is demonstrated, that the optically pumped light emission overlaps with the methane absorption lines, suggesting that GeSn alloys are well suited for mid-infrared integrated gas sensors on Si chips.
RESUMEN
Osteoarthritis (OA) is the most common cause of joint chronic pain and involves the entire joints. Subchondral osteoarthritic osteoblasts present a mineralization defect and, to date, only a few molecules (Vitamin D3 and Bone Morphogenetic Protein2) could improve the mineralization potential of this cell type. In this context, we have tested for the first time the effect of nacre extract on the mineralization capacity of osteoblasts from OA patients. Nacre extract is known to contain osteogenic molecules which have demonstrated their activities notably on the MC3T3 pre-osteoblastic cell line. For this goal, molecules were extracted from nacre (ESM, Ethanol Soluble Matrix) and tested on osteoblasts of the subchondral bone from OA patients undergoing total knee replacement and on MC3T3 cells for comparison. We chose to investigate the mineralization with Alizarin Red staining and with the study of extracellular matrix (ECM) structure and composition. In a complementary way the structure of the ECM secreted during the mineralization phase was investigated using second harmonic generation (SHG). Nacre extract was able to induce the early presence (after 7 days) of precipitated calcium in cells. Raman spectroscopy and electron microscopy showed the presence of nanograins of an early crystalline form of calcium phosphate in OA osteoblasts ECM and hydroxyapatite in MC3T3 ECM. SHG collagen fibers signal was present in both cell types but lower for OA osteoblasts. In conclusion, nacre extract was able to rapidly restore the mineralization capacity of osteoarthritis osteoblasts, therefore confirming the potential of nacre as a source of osteogenic compounds.
Asunto(s)
Calcificación Fisiológica/efectos de los fármacos , Fosfatos de Calcio/metabolismo , Nácar/farmacología , Osteoartritis/metabolismo , Osteoblastos/metabolismo , Células 3T3 , Animales , Artroplastia de Reemplazo de Rodilla , Línea Celular , Subunidad alfa 1 del Factor de Unión al Sitio Principal/biosíntesis , Durapatita/metabolismo , Matriz Extracelular/metabolismo , Humanos , Ratones , Microscopía Electrónica de Rastreo , Osteocalcina/biosíntesis , Osteopontina/biosíntesis , Reacción en Cadena en Tiempo Real de la Polimerasa , Espectrometría RamanRESUMEN
The recombination suppression models of chromosomal speciation posit that chromosomal rearrangements act as partial barriers to gene flow allowing these regions to accumulate genetic incompatibilities, thus contributing to the divergence of populations. Empirical and theoretical studies exploring the requirements of these models have mostly focused on the role of inversions. Here, the recombination landscape of heterozygosity for Robertsonian (Rb) fusions is investigated in the house mouse. Laboratory-bred F1 males and females between highly differentiated races from Tunisia (Rb: 2n=22, Standard, St: 2n=40) were produced in which all Rb fusions are present as trivalents in meiosis. Recombination patterns were determined by the analysis of chiasmata and compared with previous data on the Tunisian parental mice. A comparative analysis was performed on wild-caught male mice spanning the hybrid zone between two Italian races (2n=40, 2n=22). The results showed that the chiasma characteristics of both male and female Tunisian F1 and Italian hybrids clearly differed from those of Rb and St mice. Not only was the mean chiasma number (CN) intermediate between those of the parental mice in both geographic samples, but the distribution of chiasmata along the chromosomal arms of the F1 showed a distinct mosaic pattern. In short, the proximal region in the F1 exhibited a reduced CN similar to that observed in homozygous Rb, whereas distal regions more closely matched those in St mice. These results suggest that Rb rearrangements (homozygous or heterozygous) reduce recombination in the proximal regions of the chromosomes supporting their potential role in recombination-mediated speciation models.
Asunto(s)
Evolución Molecular , Genética de Población , Ratones/genética , Recombinación Genética , Translocación Genética , Animales , Cromosomas/genética , Cruzamientos Genéticos , Femenino , Flujo Génico , Heterocigoto , Italia , Cariotipo , Masculino , Modelos Genéticos , Mosaicismo , TúnezRESUMEN
Low-voltage swing (≤1.0 V) high-contrast ratio (6 dB) electro-absorption modulation covering 1460 to 1560 nm wavelength has been demonstrated using Ge/SiGe quantum confined Stark effect (QCSE) diodes grown on a silicon substrate. The heterolayers for the devices were designed using an 8-band k.p Poisson-Schrödinger solver which demonstrated excellent agreement with the experimental results. Modelling and experimental results demonstrate that by changing the quantum well width of the device, low power Ge/SiGe QCSE modulators can be designed to cover the S- and C-telecommunications bands.
RESUMEN
In articular hyaline cartilage, chondrocytes are surrounded by an extracellular matrix which is mainly composed by collagen and proteoglycanes. Pathological specimens show a partial or complete degradation of this matrix. Therefore, it could be interesting to know how mechanical or biochemical constraints applied to cartilage specimens induce modifications of the cartilage network. Multiphoton technology combined to Second Harmonic Generation (SHG) enables to image cartilage specimens in a non-invasive mode with high resolution at deep penetration. By placing a band pass filter in front of the transmitted light detector, SHG signal with frequency doubled can be isolated for a new contrast imaging. SHG (second harmonic generation) is a diffusion process generated from organized structures and does not need any fluorescent staining. Due to their non-centrosymetric structure, collagen fibrilles present a high second-order non-linear susceptibility and thus give rise to a strong SHG signal when exposed to high enough electric fields produced by a focal point of a femtosecond pulsed laser (multiphoton microscopy). As the extracellular matrix of cartilage is in part constituted by collagen fibers, it can be imaged with this contrast tool. The intensity of SHG signals strongly depends on the organization of collagen fibers. Thus a modification of the extracellular matrix in terms of 3D-organization of collagen induced by mechanical stress can be shown with this contrast tool.
Asunto(s)
Cartílago/patología , Matriz Extracelular/metabolismo , Matriz Extracelular/patología , Microscopía de Fluorescencia por Excitación Multifotónica/métodos , Microscopía de Interferencia/instrumentación , Cartílago/metabolismo , Cartílago Articular/metabolismo , Cartílago Articular/patología , Colágeno/metabolismo , Fuerza Compresiva , Humanos , Proteoglicanos/metabolismo , Estrés Mecánico , Estrés FisiológicoRESUMEN
Imaging thick and opaque tissue, like blood vessel, in a noninvasive mode with high resolution, is nowadays possible with multiphoton technology. A near-infrared excitation presents the advantage to be compatible with living specimens and allows a deep penetration into tissues. The nonlinear excitation process is followed by several deactivation ways, among which fluorescence emission can be represented with Spectral or Lifetime imaging. Applied to ex vivo blood vessel imaging, these techniques enabled us to discriminate cell structures (nucleus, cytoskeleton) by fluorescent labelling (Hoechst, QDots). Another method, based on 2-photon excitation and which doesn't need any exogenous dye has also been experimented on arteries: SHG (Second Harmonic Generation) is a diffusion process generated from organized structures. Collagen molecules give rise to a strong SHG signal, enabling us to image the arterial wall (3-dimensional extracellular matrix).
Asunto(s)
Vasos Sanguíneos/ultraestructura , Microscopía de Fluorescencia por Excitación Multifotónica/métodos , Animales , Vasos Sanguíneos/citología , Humanos , Imagenología Tridimensional , Rayos InfrarrojosRESUMEN
Polyelectrolyte multilayer films were recently investigated to favour attachment of Human Vein Umbilical Endothelial Cells (HUVECs) on non-adhesive surfaces. In this study, we evaluated the initial adhesion of HUVECs after 3 h of seeding on two polyelectrolyte multilayer films ending by poly(D-lysine) (PDL) or poly(allylamine hydrochloride) (PAH). In order to obtain information about initial adhesion of HUVECs, cell morphology as well as the expression of beta1 integrins, specific receptors of adhesion, were evaluated after 3 h of seeding on polyelectrolyte multilayer films. The data were also compared to PDL or PAH monolayers (polyelectrolytes terminating the multilayer architecture). The expression of beta1 integrins was not different, whatever are the studied surfaces. However, HUVECs spreading on polyelectrolyte multilayer films, in particular on PAH ending film, was more important as compared to polyelectrolyte monolayers or glass. In conclusion, the best initial adhesion conditions of HUVECs on polyelectrolyte films could not be elucidated, moreover the results suggested also that beta1 integrins could only play a limited role.
Asunto(s)
Materiales Biocompatibles/química , Células Endoteliales/citología , Actinas/metabolismo , Adhesión Celular , Células Cultivadas , Electrólitos , Endotelio Vascular/citología , Humanos , Integrina beta1/metabolismo , Microscopía de Fuerza Atómica , Poliaminas/química , Polilisina/química , Propiedades de Superficie , Venas Umbilicales/citologíaRESUMEN
Decellularized allograft tissues have been identified as a potential extracellular matrix scaffold for tissue-engineered vascular substitutes. In order to improve the thromboresistance, it is necessary to pre-coat the intra-luminal vessel surface. Recently a new surface modification technique appeared, based on the alternate adsorption of positive and negative charged polyelectrolytes. Our objective was to develop an alternative vascular scaffold made of decellularized human umbilical arteries treated with a PAH/PSS polyelectrolyte multilayered film. The vessels luminal surfaces covered with the multilayer film were observed by electronic scanning microscopy. Our observations showed that the luminal surface is completely devoid of ECs following treatment with trypsin. A top view of the coated artery indicated that the multilayer uniformly covered internal surface of the vessels. The successful of the multilayer correct deposition and retention on the arterial wall were controlled by confocal microscopy using a fluorescent polyelectrolyte (rhodamine-PAH). The data suggest that decellularized cryopreserved arteries represent a potential scaffold for further vascular tissue engineering efforts. Moreover, the multilayer films can be used to coat biological surfaces and following the terminated layer (PAH or PSS), favour the cell adhesion or cell resistance.
Asunto(s)
Ingeniería de Tejidos/métodos , Arterias Umbilicales/citología , Arterias Umbilicales/patología , Arterias/patología , Sistema Cardiovascular/patología , Adhesión Celular , Criopreservación , Electrólitos , Humanos , Microscopía Confocal , Microscopía Electrónica de Rastreo , Modelos Químicos , Propiedades de Superficie , Tripsina/farmacología , Venas Umbilicales/citologíaRESUMEN
Heparan sulfate (HS) proteoglycan chains are key components of the breast tumor microenvironment that critically influence the behavior of cancer cells. It is established that abnormal synthesis and processing of HS play a prominent role in tumorigenesis, albeit mechanisms remain mostly obscure. HS function is mainly controlled by sulfotransferases, and here we report a novel cellular and pathophysiological significance for the 3-O-sulfotransferase 3-OST3A (HS3ST3A), catalyzing the final maturation step of HS, in breast cancer. We show that 3-OST3A is epigenetically repressed in all breast cancer cell lines of a panel representative of distinct molecular subgroups, except in human epidermal growth factor receptor 2-positive (HER2+) sloan-kettering breast cancer (SKBR3) cells. Epigenetic mechanisms involved both DNA methylation and histone modifications, producing different repressive chromatin environments depending on the cell molecular signature. Gain and loss of function experiments by cDNA and siRNA transfection revealed profound effects of 3-OST3A expression on cell behavior including apoptosis, proliferation, response to trastuzumab in vitro and tumor growth in xenografted mice. 3-OST3A exerted dual activities acting as tumor-suppressor in lumA-michigan cancer foundation (MCF)-7 and triple negative-MD Anderson (MDA) metastatic breast (MB)-231 cells, or as an oncogenic factor in HER2+-SKBR3 cells. Mechanistically, fluorescence-resonance energy transfer-fluorescence-lifetime imaging microscopy experiments indicated that the effects of 3-OST3A in MCF-7 cells were mediated by altered interactions between HS and fibroblast growth factor-7 (FGF-7). Further, this interplay between HS and FGF-7 modulated downstream ERK, AKT and p38 cascades, suggesting that altering 3-O-sulfation affects FGFR2IIIb-mediated signaling. Corroborating our cellular data, a clinical study conducted in a cohort of breast cancer patients uncovered that, in HER2+ patients, high level expression of 3-OST3A in tumors was associated with reduced relapse-free survival. Our findings define 3-OST3A as a novel regulator of breast cancer pathogenicity, displaying tumor-suppressive or oncogenic activities in a cell- and tumor-dependent context, and demonstrate the clinical value of the HS-O-sulfotransferase 3-OST3A as a prognostic marker in HER2+ patients.
Asunto(s)
Biomarcadores de Tumor/genética , Neoplasias de la Mama/genética , Receptor ErbB-2/genética , Sulfotransferasas/genética , Animales , Neoplasias de la Mama/patología , Metilación de ADN/genética , Femenino , Heparitina Sulfato/genética , Humanos , Células MCF-7 , Ratones , Pronóstico , Transducción de Señal , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
In this work, we investigated a voltage-sensitive fluorescent system to monitor membrane potential by spectral and lifetime fluorescence microscopy. A two-component FRET sensor has been designed that utilizes fluorescent phospholipids acceptor (DHPE-TRITC) bound on one side of the membrane and donor molecules (oxonol) which are sensitive to membrane potential. We used multiphoton excitation and FLIM to deliver contrast lifetimes of different line cancerous cells. These results provide new information concerning the differential response to depolarized cancerous cells from resting cells when compared to fibroblast normal cells. Given the sensitivity and the fast time response, this FRET system may be particularly useful for applications involving compression of tissues by mechanical forces.
Asunto(s)
Potenciales de la Membrana , Microscopía Fluorescente/métodos , Animales , Fenómenos Biomecánicos , Línea Celular Tumoral , Transferencia Resonante de Energía de Fluorescencia , Colorantes Fluorescentes , Semivida , Humanos , MétodosRESUMEN
We studied the effect of mechanical forces (shear stress) on the kinetics of internalization of native LDL and ox-LDL in endothelial cell line ECV304. This study was performed by using Confocal microscopy and FRET with two carbocyanine dyes, 1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine perchlorate (DiO) as the donor and 3,3'-dioctadecyloxacarbocyanine perchlorate (DiI) as the receptor. The cells were incubated with a culture medium containing either 10 microg/ml DiI-LDL or DiO-LDL in static conditions or subjected to a laminar flow under a Confocal Laser Scanning Microscope (SP2 Leica, Germany). The results showed: (1) the possibility to evaluate the kinetics of LDL endocytosis in living cells, (2) shear stress in comparison with control group more effectively enhanced LDL uptake, (3) ox-LDL (>50 microg/ml) >4 hours incubation was found to affect the cells as reflected by their detachment at low shear stress.
Asunto(s)
Endocitosis , Células Endoteliales/metabolismo , Lipoproteínas LDL/metabolismo , Línea Celular , Transferencia Resonante de Energía de Fluorescencia , Colorantes Fluorescentes , Humanos , Cinética , Microscopía Confocal , Estrés MecánicoRESUMEN
The synthesis and gastric antisecretory activity of a series of indole-1-alkanamides and pyrrole-1-alkanamides are presented. A marked elevation of the pH of the gastric secretions of the rat was observed after oral administration of 100 mg/kg of 2,3-dimethylindole-1-acetamide (2), -1-propionamide (8), and -1-butyramide (13). Replacement of either methyl group by a hydrogen atom or an ethyl radical resulted in greatly diminished activity. In the acetamide and propionamide series the 3-hydroxymethyl-2-methyl (14 and 15) derivatives exhibited activity but only when administered by the subcutaneous route. 2,3-Dimethylindole (18) was active and 2,3,4,5-tetramethylpyrrole-1-acetamide was moderately active. A number of the activ compounds were tested in the mouse mydriasis test for anticholinergic activity and found to be inactive. They were also found to be inactive in blocking histamine-induced acid secretion in the dog.
Asunto(s)
Antiulcerosos/síntesis química , Indoles/síntesis química , Pirroles/síntesis química , Animales , Perros , Jugo Gástrico/metabolismo , Cobayas , Frecuencia Cardíaca/efectos de los fármacos , Técnicas In Vitro , Indoles/farmacología , Masculino , Ratones , Pupila/efectos de los fármacos , Pirroles/farmacología , Ratas , Relación Estructura-Actividad , Vómitos/inducido químicamenteRESUMEN
The influence of lipid-lowering therapy employing a historic cohort study design was assessed following heart transplantation. Lipid-lowering therapy appears to confer a survival benefit in cardiac transplant recipients who survive beyond the first year.
Asunto(s)
Gemfibrozilo/uso terapéutico , Trasplante de Corazón/mortalidad , Hiperlipidemias/tratamiento farmacológico , Hipolipemiantes/uso terapéutico , Adulto , Colesterol/sangre , Estudios de Cohortes , Femenino , Humanos , Masculino , Persona de Mediana Edad , Análisis de Supervivencia , Triglicéridos/sangreRESUMEN
Thyroid cell cyclic AMP synthesis is stimulated by beta-adrenergic agonists. We have characterized this sensitivity on cultured porcine thyroid cells and have studied its modulation by chronic treatment with thyrotrophin. The synthesis of cyclic AMP in intact porcine thyroid cells in primary culture was stimulated by the beta-adrenergic agonist, isoproterenol. This stimulation was dose-dependent and was inhibited by the beta-adrenergic antagonists propranolol and alprenolol. The cell responsiveness (i.e. the response elicited by 5 microM-isoproterenol after 5-min stimulation) was increased when the cells were cultured in the absence of thyrotrophin. Thyrotrophin, when present in the culture medium at the onset of culturing, inhibited this increase. A concentration of 100 microunits. thyrotrophin/ml was sufficient to reduce the cyclic AMP response to 15% of its control value. Prostaglandin E2 or dibutyryl cyclic AMP did not mimic the effect of thyrotrophin. The low sensitivity of thyrotrophin-treated cells to beta-adrenergic agonists could be explained by a decreased number of beta-adrenergic receptors. [125I]Iodohydroxybenzyl pindolol specific binding was ten times greater in membrane preparations of control cells than in membranes derived from thyrotrophin-treated cells. The beta-adrenergic sensitivity of cultured thyroid cells was also decreased after long-term treatment by terbutaline. A time- and dose-dependent desensitization was observed.
Asunto(s)
AMP Cíclico/biosíntesis , Isoproterenol/farmacología , Glándula Tiroides/efectos de los fármacos , Tirotropina/farmacología , Alprenolol/farmacología , Animales , Células Cultivadas , Propranolol/farmacología , Estimulación Química , Porcinos , Glándula Tiroides/citología , Glándula Tiroides/metabolismoRESUMEN
Flow cytometry was used to demonstrate the presence of beta-lactoglobulin (betaLG) receptors on living murine hybridoma MARK-3 cells using a fluorescein isothiocyanate-betaLG conjugate (FITC-betaLG: molar ratio of 5:1). A site occupation curve was produced using a shift in the mean channel fluorescence at various concentrations of FITC-betaLG. The binding of labelled ligand was concentration dependent and was inhibited by unlabelled betaLG. The on-rate constant was 3.2x10(2) M(-1) min(-1) and the off-rate constant was 0.002 min(-1). Scatchard plot analysis gave a dissociation constant (K(d)) of 44+/-21x10(-7) and 39+/-24x10(-5) M (n=3). Flow cytometry indicated that at least 15% of the FITC-betaLG were internalized for 5 min and that internalization was temperature- and time-dependent. The internalization was confirmed by 3-D fluorescence microscopy (CELLScan system).
Asunto(s)
Citometría de Flujo , Hibridomas/química , Lactoglobulinas/metabolismo , Receptores de Superficie Celular/análisis , Animales , Bovinos , Línea Celular , Fluoresceína-5-Isotiocianato , Colorantes Fluorescentes , Ratones , Receptores de Superficie Celular/metabolismoRESUMEN
Clobenzorex, an optically active N-substituted derivative of (+)amphetamine, has been identified on the illicit market. Because so little is known regarding the pharmacology or abuse potential of this agent, it was examined in tests of stimulus generalization in rats trained to discriminate 1 mg/kg of (+)amphetamine from vehicle to determine if it would produce amphetamine-appropriate responding. Clobenzorex (ED50 = 6.6 mg/kg) substituted for (+)amphetamine (ED50 = 0.3 mg/kg) but was approximately twenty times less potent than the training drug. Clobenzorex was also compared with (+)amphetamine and cocaine for its ability to induce locomotor stimulation and rearing frequency in mice. Clobenzorex was active in both assays but was less potent than either (+)amphetamine or cocaine. It is concluded that, although weaker than (+)amphetamine, clobenzorex constitutes an agent with amphetamine-like central stimulant behavioral properties.
Asunto(s)
Anfetamina/farmacología , Anfetaminas/farmacología , Depresores del Apetito/farmacología , Estimulantes del Sistema Nervioso Central/farmacología , Aprendizaje Discriminativo/efectos de los fármacos , Actividad Motora/efectos de los fármacos , Animales , Femenino , Masculino , Ratones , Ratones Endogámicos ICR , Ratas , Ratas Sprague-DawleyRESUMEN
On 11 June 1996, three suspected cases of legionnaires disease in a group of 42 Dutch tourists were reported to the local public health authority by Millau hospital in south west France. The group (group 1) had been touring with caravans and staying at d
RESUMEN
The role of clustered of L-selectin receptors on the leukocyte surface is discussed in connection with the postulated velocity-dependent formation of selectin-ligand tether bonds to interpret the mechanism of leukocyte tethering to, and rolling along, the vascular endothelium. The distinct feature of this step-wise process is a weak dependence of leukocyte rolling velocity on the hydrodynamic forces of ambient flow due to the increased number of selectin bonds with increasing flow shear rate and also their clustering. The contact zones on the leukocyte surface are separated by distances with distribution which corresponds to the distribution of distances of the observed L-selectin clusters. It suggests that the localization of L-selectin receptors to clusters and the way of their approach to the ligand molecules creates such conditions for binding of L-selectin and ligand molecules that resulting number of bonds stabilizes rolling velocity.
Asunto(s)
Selectina L/fisiología , Rodamiento de Leucocito/fisiología , Modelos Biológicos , Neutrófilos/fisiología , Velocidad del Flujo Sanguíneo/fisiología , Adhesión Celular/fisiología , Endotelio Vascular/fisiología , Hemorreología , Humanos , LigandosRESUMEN
The purpose of the present study was to investigate the intracellular IL-1beta production and beta1 integrins (alpha4/beta1 and alpha5/beta1) expression on chondrocytes. Chondroytes monolayer (human chondrosarcoma cell line HEM-C55) were incubated for 12, 24 and 48 hours in the presence of Tumor Necrosis Factor-alpha (TNF-alpha, Sigma, France) or recombinant human IL-1alpha (rh-IL1alpha, Becton Dickinson, France). After direct immunolabelling, cells were either analyzed on FACScan flow cytometer (Becton Dickinson, France), or observed under an epi-fluorescence inverted microscope equipped with the CellScan EPR optical scanning acquisition system (IPLab-Scanalytics, USA). We found that the IL-1beta mean fluorescence intensity in flow cytometry and in 3D microscopy was increased in the presence of TNF-alpha or rh-IL-1alpha, and alpha4/beta1 or alpha5/beta1 expression was higher on stimulated cells than on control cells. On the other hand, we have evaluated the in vitro effects of rhein (10(-5) M, Negma, France), an active metabolite of diacerein, on the intracellular IL-1beta and beta1 integrins expressed by stimulated or no-stimulated chondrocytes. The results indicated that rhein leads to a reduction of IL-1beta synthesis whereas a weak decrease of beta1 integrins receptors expression is observed. From this study, it seems that rhein partially reduce cytokine-induced intracellular IL-1beta production, and it has a weak action on alpha4/beta1 or alpha5/beta1 receptors.
Asunto(s)
Cartílago Articular/inmunología , Condrocitos/inmunología , Integrina beta1/biosíntesis , Interleucina-1/biosíntesis , Antraquinonas/farmacología , Condrosarcoma , Inhibidores Enzimáticos/farmacología , Citometría de Flujo , Humanos , Integrina alfa4beta1 , Integrinas/metabolismo , Interleucina-1/farmacología , Microscopía Fluorescente , Receptores de Fibronectina/metabolismo , Receptores de Interleucina-1/metabolismo , Receptores Mensajeros de Linfocitos/metabolismo , Proteínas Recombinantes/farmacología , Estimulación Química , Células Tumorales Cultivadas , Factor de Necrosis Tumoral alfa/farmacologíaRESUMEN
The increase in lateral and spatial resolutions is one of the major targets of research and development in the field of optical microscopies applied to living tissue. The optical geometry of Confocal Laser Scanning Microscopy (CLSM) demonstrates its undeniable advantage on conventional fluorescence microscopy by segregating the planes outside the focussing plane. The methodological and technological advances of the last five years have been fast evolving, especially with regard to the optimisation of CLSM and deconvolution process. The limited analysis in thick tissue have given rise to the development of other techniques, multi-photon excitation microscopy in particular. In this paper, we have applied these techniques on major biological applications in bioengineering (endothelial cell, chondrocyte in 3D-culture, human cartilage) and discussed the technical limitations and perspectives.