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1.
Blood Cancer J ; 14(1): 75, 2024 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-38697976

RESUMO

Follicular lymphoma (FL), the most common indolent non-Hodgkin lymphoma, constitutes a paradigm of immune tumor microenvironment (TME) contribution to disease onset, progression, and heterogenous clinical outcome. Here we present the first FL-Patient Derived Lymphoma Spheroid (FL-PDLS), including fundamental immune actors and features of TME in FL lymph nodes (LNs). FL-PDLS is organized in disc-shaped 3D structures composed of proliferating B and T cells, together with macrophages with an intermediate M1/M2 phenotype. FL-PDLS recapitulates the most relevant B-cell transcriptional pathways present in FL-LN (proliferation, epigenetic regulation, mTOR, adaptive immune system, among others). The T cell compartment in the FL-PDLS preserves CD4 subsets (follicular helper, regulatory, and follicular regulatory), also encompassing the spectrum of activation/exhaustion phenotypes in CD4 and CD8 populations. Moreover, this system is suitable for chemo and immunotherapy testing, recapitulating results obtained in the clinic. FL-PDLS allowed uncovering that soluble galectin-9 limits rituximab, rituximab, plus nivolumab/TIM-3 antitumoral activities. Blocking galectin-9 improves rituximab efficacy, highlighting galectin-9 as a novel immunotherapeutic target in FL. In conclusion, FL-PDLS maintains the crosstalk between malignant B cells and the immune LN-TME and constitutes a robust and multiplexed pre-clinical tool to perform drug screening in a patient-derived system, advancing toward personalized therapeutic approaches.


Assuntos
Galectinas , Linfonodos , Linfoma Folicular , Microambiente Tumoral , Humanos , Linfoma Folicular/imunologia , Linfoma Folicular/patologia , Linfoma Folicular/terapia , Linfonodos/patologia , Linfonodos/imunologia , Microambiente Tumoral/imunologia , Esferoides Celulares , Imunoterapia/métodos , Transdução de Sinais , Células Tumorais Cultivadas
2.
J Immunother Cancer ; 11(10)2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37899130

RESUMO

BACKGROUND: Follicular lymphoma (FL), the most common indolent non-Hodgkin's Lymphoma, is a heterogeneous disease and a paradigm of the contribution of immune tumor microenvironment to disease onset, progression, and therapy resistance. Patient-derived models are scarce and fail to reproduce immune phenotypes and therapeutic responses. METHODS: To capture disease heterogeneity and microenvironment cues, we developed a patient-derived lymphoma spheroid (FL-PDLS) model culturing FL cells from lymph nodes (LN) with an optimized cytokine cocktail that mimics LN stimuli and maintains tumor cell viability. RESULTS: FL-PDLS, mainly composed of tumor B cells (60% on average) and autologous T cells (13% CD4 and 3% CD8 on average, respectively), rapidly organizes into patient-specific three-dimensional (3D) structures of three different morphotypes according to 3D imaging analysis. RNAseq analysis indicates that FL-PDLS reproduces FL hallmarks with the overexpression of cell cycle, BCR, or mTOR signaling related gene sets. FL-PDLS also recapitulates the exhausted immune phenotype typical of FL-LN, including expression of BTLA, TIGIT, PD-1, TIM-3, CD39 and CD73 on CD3+ T cells. These features render FL-PDLS an amenable system for immunotherapy testing. With this aim, we demonstrate that the combination of obinutuzumab (anti-CD20) and nivolumab (anti-PD1) reduces tumor load in a significant proportion of FL-PDLS. Interestingly, B cell depletion inversely correlates with the percentage of CD8+ cells positive for PD-1 and TIM-3. CONCLUSIONS: In summary, FL-PDLS is a robust patient-derived 3D system that can be used as a tool to mimic FL pathology and to test novel immunotherapeutic approaches in a context of personalized medicine.


Assuntos
Linfoma Folicular , Humanos , Linfoma Folicular/tratamento farmacológico , Linfoma Folicular/genética , Receptor Celular 2 do Vírus da Hepatite A , Receptor de Morte Celular Programada 1/metabolismo , Microambiente Tumoral , Medicina de Precisão
3.
PLoS Pathog ; 19(8): e1011559, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37619220

RESUMO

Mycobacterium abscessus (Mabs) drives life-shortening mortality in cystic fibrosis (CF) patients, primarily because of its resistance to chemotherapeutic agents. To date, our knowledge on the host and bacterial determinants driving Mabs pathology in CF patient lung remains rudimentary. Here, we used human airway organoids (AOs) microinjected with smooth (S) or rough (R-)Mabs to evaluate bacteria fitness, host responses to infection, and new treatment efficacy. We show that S Mabs formed biofilm, and R Mabs formed cord serpentines and displayed a higher virulence. While Mabs infection triggers enhanced oxidative stress, pharmacological activation of antioxidant pathways resulted in better control of Mabs growth and reduced virulence. Genetic and pharmacological inhibition of the CFTR is associated with better growth and higher virulence of S and R Mabs. Finally, pharmacological activation of antioxidant pathways inhibited Mabs growth, at least in part through the quinone oxidoreductase NQO1, and improved efficacy in combination with cefoxitin, a first line antibiotic. In conclusion, we have established AOs as a suitable human system to decipher mechanisms of CF-driven respiratory infection by Mabs and propose boosting of the NRF2-NQO1 axis as a potential host-directed strategy to improve Mabs infection control.


Assuntos
Fibrose Cística , Mycobacterium abscessus , Humanos , Fibrose Cística/tratamento farmacológico , Antioxidantes , Oxirredução , Estresse Oxidativo
4.
Leukemia ; 37(6): 1311-1323, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-37031299

RESUMO

Mantle cell lymphoma (MCL), a rare and aggressive B-cell non-Hodgkin lymphoma, mainly develops in the lymph node (LN) and creates a protective and immunosuppressive niche that facilitates tumor survival, proliferation and chemoresistance. To capture disease heterogeneity and tumor microenvironment (TME) cues, we have developed the first patient-derived MCL spheroids (MCL-PDLS) that recapitulate tumor oncogenic pathways and immune microenvironment in a multiplexed system that allows easy drug screening, including immunotherapies. MCL spheroids, integrated by tumor B cells, monocytes and autologous T-cells self-organize in disc-shaped structures, where B and T-cells maintain viability and proliferate, and monocytes differentiate into M2-like macrophages. RNA-seq analysis demonstrated that tumor cells recapitulate hallmarks of MCL-LN (proliferation, NF-kB and BCR), with T cells exhibiting an exhaustion profile (PD1, TIM-3 and TIGIT). MCL-PDLS reproduces in vivo responses to ibrutinib and demonstrates that combination of ibrutinib with nivolumab (anti-PD1) may be effective in ibrutinib-resistant cases by engaging an immune response with increased interferon gamma and granzyme B release. In conclusion, MCL-PDLS recapitulates specific MCL-LN features and in vivo responses to ibrutinib, representing a robust tool to study MCL interaction with the immune TME and to perform drug screening in a patient-derived system, advancing toward personalized therapeutic approaches.


Assuntos
Linfoma de Célula do Manto , Humanos , Adulto , Linhagem Celular Tumoral , Linfoma de Célula do Manto/patologia , Resistencia a Medicamentos Antineoplásicos , Adenina/uso terapêutico , Microambiente Tumoral
5.
Toxicon ; 212: 34-41, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35413334

RESUMO

BACKGROUND: Botulinum neurotoxins (BoNTs) are used to treat spastic disorders. Depending on muscle size, one or multiple injections are recommended according to labels to target neuromuscular junctions (NMJ). However, information about NMJ distribution and number in muscles, as well as expression of receptors and molecular targets of toxins is scarce in human and animal models. METHODS: Seven muscles from adult rats were used to identify expression of BoNT receptors and SNAREs using immunohistochemistry (IHC), and fluorescent α-Bungarotoxin combined to light-sheet microscopy used to determine their distribution. RESULTS: The location, number, and density of NMJ were muscle specific and mostly dependent on the type of pennation (myofiber orientation). In the Flexor Digitorum Brevis (a very small muscle) NMJ were as numerous as in the Gastrocnemius lateralis. A strong expression of SV2C, Synaptotagmin 2, SNAP25 and VAMP1 were observed in all muscles, and SV2A, Synaptotagmin 1 and VAMP2 were never detected. CONCLUSION: This work highlights the specific distribution of NMJ in muscles which seems to depend on the type of pennation. Detailed observation of myofibers organization might help clinicians to better evaluate the location of NMJ in humans; the molecular phenotyping of NMJ will contribute to better integrate the rat model into research of BoNT therapeutics.


Assuntos
Toxinas Botulínicas Tipo A , Animais , Toxinas Botulínicas Tipo A/metabolismo , Espasticidade Muscular , Músculo Esquelético , Junção Neuromuscular , Ratos
6.
Eur J Nutr ; 61(4): 2201-2215, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35092460

RESUMO

PURPOSE: Excessive fat mass accumulation in obesity leads to diverse metabolic disorders, increased risks of cardiovascular diseases and in some cases, mortality. The aim of this study was to screen the actions of botanical extracts intended for oral use on human adipose tissue, using an in vitro screening model combining human intestinal cells with human adipose cells. This was to find the most effective extracts on lipid accumulation, UCP1 expression and ATP production in pre-adipocytes and on adipocyte lipolysis. METHODS: In this study, 25 individual plant extracts were screened for their effects on human adipose cells. Consequently, an original in vitro model was set up using the Caco-2 cell line, to mimic the intestinal passage of the extracts and then exposing human adipose cells to them. The biological actions of extracts were thus characterized, and compared with a coffee extract standard. The most effective extracts, and their combinations, were retained for their actions on lipid accumulation, the expression of the thermogenic effector UCP1 and ATP production in pre-adipocytes as well as on lipolysis activity of mature adipocytes. RESULTS: The biphasic culture system combining human Caco-2 cells with human adipose cells was verified as functional using the green coffee extract standard. Out of the 25 plant extracts studied, only 7 and their combinations were retained due to their potent effects on adipose cells biology. The data showed that compared to the coffee extract standard, Immortelle, Catechu, Carrot and Rose hip extracts were the most effective in reducing lipid accumulation and increased UCP1 expression in human pre-adipocytes. CONCLUSION: This study reveals the potential inhibitory effects on lipid accumulation and thermogenic activity of Immortelle, Catechu, Carrot and Rose hip extracts, and for the first time synergies in their combinations, using an in vitro model mimicking as closely as possible, human intestinal passage linked to adipose cells. These findings need to be confirmed by in vivo trials.


Assuntos
Café , Lipólise , Trifosfato de Adenosina/metabolismo , Trifosfato de Adenosina/farmacologia , Adipócitos , Tecido Adiposo/metabolismo , Tecido Adiposo Marrom , Células CACO-2 , Café/metabolismo , Humanos , Lipídeos , Extratos Vegetais/metabolismo , Extratos Vegetais/farmacologia
7.
Cancers (Basel) ; 13(7)2021 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-33804934

RESUMO

Follicular lymphoma (FL) is an indolent B cell lymphoproliferative disorder of transformed follicular center B cells, which accounts for 20-30 percent of all non-Hodgkin lymphoma (NHL) cases. Great advances have been made to identify the most relevant targets for precision therapy. However, no relevant models for in vitro studies have been developed or characterized in depth. To this purpose, we generated a 3D cell model from t(14;18)-positive B-NHL cell lines cultured in ultra-low attachment 96-well plates. Morphological features and cell growth behavior were evaluated by classical microscopy (2D imaging) and response to treatment with different drugs was evaluated by a high-content analysis system to determine the robustness of the model. We show that the ultra-low attachment (ULA) method allows the development of regular, spherical and viable ULA-multicellular aggregates of lymphoma cells (MALC). However, discrepancies in the results obtained after 2D imaging analyses on drug-treated ULA-MALC prompted us to develop 3D imaging and specific analyses. We show by using light sheet microscopy and specifically developed 3D imaging algorithms that 3D imaging and dedicated analyses are necessary to characterize morphological properties of 3D models and drug effects. This study proposes a new method, but also imaging tools and informatic solutions, developed for FL necessary for future preclinical studies.

8.
Biomedicines ; 8(12)2020 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-33256205

RESUMO

As a live biologic agent, oncolytic vaccinia virus has the ability to target and selectively amplify at tumor sites. We have previously reported that deletion of thymidine kinase and ribonucleotide reductase genes in vaccinia virus can increase the safety and efficacy of the virus. Here, to allow direct visualization of the viral genome in living cells, we incorporated the ANCH target sequence and the OR3-Santaka gene in the double-deleted vaccinia virus. Infection of human tumor cells with ANCHOR3-tagged vaccinia virus enables visualization and quantification of viral genome dynamics in living cells. The results show that the ANCHOR technology permits the measurement of the oncolytic potential of the double deleted vaccinia virus. Quantitative analysis of infection kinetics and of viral DNA replication allow rapid and efficient identification of inhibitors and activators of oncolytic activity. Our results highlight the potential application of the ANCHOR technology to track vaccinia virus and virtually any kind of poxvirus in living cells.

9.
Oncoimmunology ; 8(3): 1554175, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30723586

RESUMO

Follicular lymphoma (FL) is a common non Hodgkin's lymphoma subtype in which immune escape mechanisms are implicated in resistance to chemo-immunotherapy. Although molecular studies point to qualitative and quantitative deregulation of immune checkpoints, in depth cellular analysis of FL immune escape is lacking. Here, by functional assays and in silico analyses we show that a subset of FL patients displays a 'high' immune escape phenotype. These FL cases are characterized by abundant infiltration of PD1+ CD16+ TCRVγ9Vδ2 γδ T lymphocytes. In a 3D co-culture assay (MALC), γδ T cells mediate both direct and indirect (ADCC in the presence of anti-CD20 mAbs) cytolytic activity against FL cell aggregates. Importantly, PD-1, which is expressed by most FL-infiltrating γδ T lymphocytes with ADCC capacity, impairs these functions. In conclusion, we identify a PD1-regulated γδ T cell cytolytic immune component in FL. Our data provide a treatment rational by PD-1 blockade aimed at boosting γδ T cell anti-tumor functions in FL.

10.
J Virol ; 92(18)2018 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-29997215

RESUMO

Adenoviruses are DNA viruses with a lytic infection cycle. Following the fate of incoming as well as recently replicated genomes during infections is a challenge. In this study, we used the ANCHOR3 technology based on a bacterial partitioning system to establish a versatile in vivo imaging system for adenoviral genomes. The system allows the visualization of both individual incoming and newly replicated genomes in real time in living cells. We demonstrate that incoming adenoviral genomes are attached to condensed cellular chromatin during mitosis, facilitating the equal distribution of viral genomes in daughter cells after cell division. We show that the formation of replication centers occurs in conjunction with in vivo genome replication and determine replication rates. Visualization of adenoviral DNA revealed that adenoviruses exhibit two kinetically distinct phases of genome replication. Low-level replication occurred during early replication, while high-level replication was associated with late replication phases. The transition between these phases occurred concomitantly with morphological changes of viral replication compartments and with the appearance of virus-induced postreplication (ViPR) bodies, identified by the nucleolar protein Mybbp1A. Taken together, our real-time genome imaging system revealed hitherto uncharacterized features of adenoviral genomes in vivo The system is able to identify novel spatiotemporal aspects of the adenovirus life cycle and is potentially transferable to other viral systems with a double-stranded DNA phase.IMPORTANCE Viruses must deliver their genomes to host cells to ensure replication and propagation. Characterizing the fate of viral genomes is crucial to understand the viral life cycle and the fate of virus-derived vector tools. Here, we integrated the ANCHOR3 system, an in vivo DNA-tagging technology, into the adenoviral genome for real-time genome detection. ANCHOR3 tagging permitted the in vivo visualization of incoming genomes at the onset of infection and of replicated genomes at late phases of infection. Using this system, we show viral genome attachment to condensed host chromosomes during mitosis, identifying this mechanism as a mode of cell-to-cell transfer. We characterize the spatiotemporal organization of adenovirus replication and identify two kinetically distinct phases of viral genome replication. The ANCHOR3 system is the first technique that allows the continuous visualization of adenoviral genomes during the entire virus life cycle, opening the way for further in-depth study.


Assuntos
Adenoviridae/fisiologia , Cromatina/virologia , DNA Viral/metabolismo , Replicação Viral , Adenoviridae/genética , Linhagem Celular , Cromatina/genética , Proteínas de Ligação a DNA , Genoma Viral , Células HEK293 , Humanos , Cinética , Estágios do Ciclo de Vida , Proteínas Nucleares/metabolismo , Proteínas de Transporte Nucleocitoplasmático/metabolismo , Proteínas de Ligação a RNA , Coloração e Rotulagem , Fatores de Transcrição , Ligação Viral
11.
Oncol Lett ; 12(6): 4371-4376, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28105152

RESUMO

Pharmacological evaluation of anticancer drugs using 3D in vitro models provides invaluable information for predicting in vivo activity. Artificial matrices are currently available that scale up and increase the power of such 3D models. The aim of the present study was to propose an efficient and robust imaging and analysis pipeline to assess with quantitative parameters the efficacy of a particular cytotoxic drug. HCT116 colorectal adenocarcinoma tumor cell multispheres were grown in a 3D physiological hyaluronic acid matrix. 3D microscopy was performed with structured illumination, whereas image processing and feature extraction were performed with custom analysis tools. This procedure makes it possible to automatically detect spheres in a large volume of matrix in 96-well plates. It was used to evaluate drug efficacy in HCT116 spheres treated with different concentrations of topotecan, a DNA topoisomerase inhibitor. Following automatic detection and quantification, changes in cluster size distribution with a topotecan concentration-dependent increase of small clusters according to drug cytotoxicity were observed. Quantitative image analysis is thus an effective means to evaluate and quantify the cytotoxic and cytostatic activities of anticancer drugs on 3D multicellular models grown in a physiological matrix.

12.
Exp Dermatol ; 21(4): 281-6, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22417304

RESUMO

Reflectance confocal microscopy (RCM) may help to quantify variations of skin pigmentation induced by different stimuli such as UV radiation or therapeutic intervention. The objective of our work was to identify RCM parameters able to quantify in vivo dermis papilla density and epidermis pigmentation potentially applicable in clinical studies. The study included 111 healthy female volunteers with phototypes I-VI. Photo-exposed and photo-protected anatomical sites were imaged. The effect of age was also assessed. Four epidermis components were specifically investigated: stratum corneum, stratum spinosum, basal epidermal layer and dermo-epidermal junction. Laser power, diameter of corneocytes and upper spinous keratinocytes, brightness of upper spinous and interpapillary spinous keratinocytes, number of dermal papillae and papillary contrast were systematically assessed. Papillary contrast measured at the dermo-epidermal junction appeared to be a reliable marker of epidermis pigmentation and showed a strong correlation with skin pigmentation assessed clinically using the Fitzpatrick's classification. Brightness of upper spinous and interpapillary spinous keratinocytes was not influenced by the skin phototype. The number of dermal papillae was significantly lower in subjects with phototypes I-II as compared with darker skin subjects. A dramatic reduction in the number of dermal papillae was noticed with age, particularly in subjects with fair skin. The method presented here provides a new in vivo investigation tool for quantification of dermis papilla density and epidermal pigmentation. Papillary contrast measured at the dermo-epidermal junction may be selected as a marker of skin pigmentation for evaluation in clinical studies.


Assuntos
Derme/anatomia & histologia , Derme/fisiologia , Microscopia Confocal/métodos , Pigmentação da Pele/fisiologia , Adolescente , Adulto , Idoso , Envelhecimento/patologia , Envelhecimento/fisiologia , Derme/efeitos da radiação , Feminino , Humanos , Queratinócitos/patologia , Queratinócitos/fisiologia , Pessoa de Meia-Idade , Envelhecimento da Pele/patologia , Envelhecimento da Pele/fisiologia , Pigmentação da Pele/efeitos da radiação , Raios Ultravioleta , Adulto Jovem
13.
IEEE Trans Image Process ; 20(10): 2876-85, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21507774

RESUMO

Digital imaging devices are increasingly used for color measurements in fields such as forensics, the food industry, and ecological and medical research. Especially concerning the skin, in the follow-up of benign or malignant lesions, it is crucial to ensure that the measured colors are accurate and reproducible. Several color calibration methods having been presented over the last few years. However, the choice of illuminant used remains a major source of color misinterpretation, thus, much effort is being spent in trying to evaluate this a posteriori. The device presented overcomes this problem by integrating its own light source, although corrections in lighting heterogeneity are still required. In this paper, we present a lighting modelling technique used for shading correction which improves color consistency (as assessed by ∆E evaluation versus colorimeter), noise filtering, computation time, and memory consumption for this type of device.


Assuntos
Colorimetria/métodos , Diagnóstico por Imagem/métodos , Processamento de Imagem Assistida por Computador/métodos , Microscopia de Vídeo/métodos , Pigmentação da Pele , Humanos , Modelos Lineares , Microscopia de Vídeo/instrumentação
14.
Skin Res Technol ; 12(1): 24-31, 2006 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-16420535

RESUMO

INTRODUCTION: The suction test is commonly used to study the mechanical properties of human skin in vivo. The unevenness of the stress fields complicates obtaining the intrinsic mechanical parameters of the skin in vivo because the values of the local stresses and deformations cannot be calculated directly from the displacements and forces applied by the test apparatus. In general, users only take into account the negative pressure applied and the elevation of the dome of skin drawn up in order to deduce the properties of the skin. This method has the major disadvantage of being dependent on the experimental conditions used: in particular, the size of the suction cup and the negative pressure applied. Here, we propose a full mechanical study of the test to provide rigorous results. We compare the frequently used geometric method (making the thin plate hypothesis), Timoshenko's method (which can take greater plate thicknesses into account) and finally various results obtained by the finite elements (FE) technique. METHODS: The suction test was modelled by FE with large displacements and large deformations both for orthotropic and isotropic plates. The results obtained in the elastic domain for various values of Young's modulus and of applied negative pressure were used as references and were compared with methods using analytical relationships. RESULTS: The geometric method generally used in the interpretation of suction tests gives results, which in certain configurations, are very different from those obtained by FE. The method of Timoshenko is suited to thick plates 'in contact' or embedded round the edge, the elevation of the dome and the tension and flexion stresss are analytically accessible through relationships involving four constants that are dependent on the limit conditions. Comparison with the FE results enabled the optimisation of the coefficients to adapt the relationships to the particular conditions of the suction trials. CONCLUSION: We showed the limits of the geometrical method and proposed a solution, which while remaining simple to use, gives results that are closer to reality both for the calculation of the modulus and for the determination of the state of the stresses obtained.


Assuntos
Fenômenos Biomecânicos/métodos , Diagnóstico por Computador/métodos , Modelos Biológicos , Estimulação Física/métodos , Fenômenos Fisiológicos da Pele , Simulação por Computador , Elasticidade , Análise de Elementos Finitos , Humanos , Pressão , Estresse Mecânico , Vácuo
15.
J Biomech ; 39(9): 1603-10, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-15990103

RESUMO

This study proposes a new method to determine the mechanical properties of human skin by the use of the indentation test [Pailler-Mattei, 2004. Caractérisation mécanique et tribologique de la peau humaine in vivo, Ph.D. Thesis, ECL-no. 2004-31; Pailler-Mattei, Zahouani, 2004. Journal of Adhesion Science and Technology 18, 1739-1758]. The principle of the measurements consists in applying an in vivo compressive stress [Zhang et al., 1994. Proceedings of the Institution of Mechanical Engineers 208, 217-222; Bosboom et al., 2001. Journal of Biomechanics 34, 1365-1368; Oomens et al., 1984. Selected Proceedings of Meetings of European Society of Biomechanics, pp. 227-232; Oomens et al., 1987. Journal of Biomechanics 20(9), 877-885] on the skin tissue of an individual's forearm. These measurements show an increase in the normal contact force as a function of the indentation depth. The interpretation of such results usually requires a long and tedious phenomenological study. We propose a new method to determine the mechanical parameters which control the response of skin tissue. This method is threefold: experimental, numerical, and comparative. It consists combining experimental results with a numerical finite elements model in order to find out the required parameters. This process uses a scheme of extended Kalman filters (EKF) [Gu et al., 2003. Materials Science and Engineering A345, 223-233; Nakamura et al., 2000. Acta Mater 48, 4293-4306; Leustean and Rosu, 2003. Certifying Kalman filters. RIACS Technical Report 03.02, 27pp. http://gureni.cs.uiuc.edu/~grosu/download/luta + leo.pdf; Welch and Bishop, An introduction to Kalman filter, University of North Carolina at Chapel Hill, 16p. http://www.cs.unc.edu/~welch/kalman/]. The first results presented in this study correspond to a simplified numerical modeling of the global system. The skin is assumed to be a semi-infinite layer with an isotropic linear elastic mechanical behavior [Zhang et al., 1994. Proceedings of the Institution of Mechanical Engineers 208, 217-222] This analysis will be extended to more realistic models in further works.


Assuntos
Fenômenos Biomecânicos/métodos , Fenômenos Fisiológicos da Pele , Humanos
16.
Skin Res Technol ; 11(2): 79-90, 2005 May.
Artigo em Inglês | MEDLINE | ID: mdl-15807804

RESUMO

BACKGROUND/PURPOSE: Measurement of dermal thickness is useful in the evaluation of dermo-cosmetics for assessing not only morphological changes but also mechanical properties of this layer. Our aim was first to standardise the manual dermal thickness measurement procedure on B-scan ultrasound images, then to develop an automatic operator independent method to detect the boundaries of the dermis. MATERIAL AND METHODS: The Dermcup 20 MHz B-scan ultrasound system was used. The method used for detecting the boundaries was adapted from active contour algorithms. The innovative aspect of the method consists in an automatic initialization of the first step of the algorithm. To validate the method, we correlated measurements obtained by the manual and automatic approaches from a set of images from different anatomical sites. RESULTS AND CONCLUSION: The results showed for the two measurement methods, 72% of the images were perfectly correlated. The remaining images required manual initialization of the boundaries by a non-expert operator before the active contour process could be used. Subsequent to this semi-automatic procedure, the correlation was very high.


Assuntos
Algoritmos , Inteligência Artificial , Interpretação de Imagem Assistida por Computador/métodos , Reconhecimento Automatizado de Padrão/métodos , Fenômenos Fisiológicos da Pele , Pele/anatomia & histologia , Pele/diagnóstico por imagem , Humanos , Aumento da Imagem/métodos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Ultrassonografia
17.
J Cosmet Laser Ther ; 6(3): 126-30, 2004 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-15545095

RESUMO

BACKGROUND/OBJECTIVE: As remodeling is getting more popular with patients, long-term studies are becoming necessary. The aim of this 35-month clinical study was to evaluate the long-term benefits obtained using a 1540-nm Er:glass laser for non-ablative remodeling of perioral and periorbital rhytids. The role of maintenance treatments was also investigated. STUDY DESIGN/METHODS: Eleven women with periorbital and perioral rhytids underwent a series of five treatments at 6-week intervals with an Er:glass laser. Five patients subsequently received two maintenance retreatments and six did not. The maintenance treatments were performed at 14 and 20 months. Silicone imprints were performed to measure anisotropy before treatment, at 6 months, at 14 months and at 35 months. Patient self-evaluation/questionnaire was also done to assess adverse effects and subjective clinical improvement. RESULTS: For all 11 patients, the percentage of anisotropy reduction was 41.21% at 6 months, 51.76% at 14 months and 29.87% at 35 months. No adverse effects were noted. Patient satisfaction was high at the end of the evaluation. Retreated patients were more satisfied than non-retreated ones. However, there was no difference in the anisotropy factor between the two groups. CONCLUSION: Treatment of facial rhytids with a non-ablative 1540-nm Er:glass laser system can produce benefits that persist over 2 years after the last treatment.


Assuntos
Terapia a Laser , Ritidoplastia , Adulto , Anisotropia , Feminino , Seguimentos , Humanos , Pessoa de Meia-Idade , Satisfação do Paciente , Retratamento
18.
J Cosmet Laser Ther ; 6(1): 5-9, 2004 May.
Artigo em Inglês | MEDLINE | ID: mdl-15370406

RESUMO

BACKGROUND: Retinaldehyde has been proven to be effective in the reduction of facial wrinkles. It has also demonstrated its usefulness when used before and after laser skin resurfacing. OBJECTIVE: A monocentric, comparative, randomized, double-blind study was performed to evaluate the efficacy of retinaldehyde versus excipient in combination with non-ablative laser remodeling treatment. METHODS: A total of 16 female patients (mean age 45 years) were enrolled for neck line and forehead rhytid treatment. They were randomly assigned into two groups. The RAL group (eight patients) was treated with a non-ablative laser (1540 nm Er:glass, 10 J/cm2 per pulse, three pulses, 2 Hz repetition rate, 4 mm spot, +5 degrees C cooling) and daily topical application of 0.05% retinaldehyde immediately after the first laser treatment and up to 3 months after the fifth treatment. The CTRL group (eight patients) was treated under similar conditions, except with a daily application of excipient. The thickness of the skin (forehead and neck) was measured by ultrasound imaging before the first treatment, 1 month after the third treatment, 1 month after the fifth treatment and 3 months after the fifth treatment. RESULTS: An increase of dermal thickness was observed for all patients treated by laser (groups RAL and CTRL) on the forehead and neck. However, the increase was greater for the RAL group (retinaldehyde) when compared with the CTRL group (excipient). Three months after the fifth treatment, the increase in dermal thickness (%) was, respectively, 5.27 versus 1.13 for the forehead and 10.54 versus 3.57 for the neck. The difference between groups was statistically significant in favor of the retinaldehyde group for the forehead (p<0.05) and of limited significance for the neck (p=0.08). CONCLUSION: When considering the reduced number of patients in each group, the statistical analysis demonstrates an evident advantage of using retinaldehyde versus excipient. This study demonstrates that irradiation with a 1540 nm Er:glass laser can be potentiated with concomitant daily topical application of 0.05% retinaldehyde.


Assuntos
Terapia a Laser , Retinaldeído/uso terapêutico , Envelhecimento da Pele , Pele/diagnóstico por imagem , Administração Tópica , Método Duplo-Cego , Esquema de Medicação , Feminino , Seguimentos , Humanos , Pessoa de Meia-Idade , Retinaldeído/administração & dosagem , Retinaldeído/química , Ultrassonografia
19.
Dermatol Surg ; 30(6): 872-9; discussion 879-80, 2004 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15171765

RESUMO

BACKGROUND: Nonablative remodeling has been recently proposed as a new, no-down-time, anti-aging treatment. Objective. The objective was to evaluate the efficacy and safety of nonablative skin remodeling with a 1540-nm Er:Glass laser on neck lines and forehead rhytids. METHODS: Twenty female patients (mean age 45 years) were enrolled. Skin thickness and mechanical properties were measured before the first treatment, 1 month after the third treatment, 1 month after the fifth treatment, and 3 months after the fifth treatment. RESULTS: All patients reported an improvement in both skin tone and texture. Using ultrasound imaging, dermal thickness of neck and forehead increased, respectively, by 70+/-13 microm (p<0.001) and 110+/-19 microm (p<0.003). A dramatic increase of initial stress of the forehead skin (firmness) was obtained, from 7.62+/-3.68 before treatment to 16.68+/-7.44 3 months after the fifth treatment (p<0.0002). No immediate or late adverse effects were noted throughout the treatment regimen. CONCLUSION: This study demonstrates that irradiation with a 1540-nm Er:Glass laser emitting in a pulsed mode and coupled with an efficient contact cooling system increases dermal thickness and firmness, leading to a clinical improvement of neck lines and forehead rhydits.


Assuntos
Dermatoses Faciais/radioterapia , Envelhecimento da Pele/patologia , Pele/patologia , Pele/efeitos da radiação , Adulto , Idoso , Dermatoses Faciais/patologia , Feminino , Testa , Humanos , Terapia com Luz de Baixa Intensidade/métodos , Pessoa de Meia-Idade , Pescoço , Ritidoplastia/métodos
20.
Skin Res Technol ; 10(2): 96-103, 2004 May.
Artigo em Inglês | MEDLINE | ID: mdl-15059176

RESUMO

BACKGROUND: The single-axis extension test is relatively little used to study the mechanical properties of human skin in vivo. A campaign of tests was carried out with an original, modern machine developed in our laboratory. It can perform extension or compression tests using servo-controlled position or force in different directions. The load can either be of the extension or monotonous compression type, creep or relaxation. The results obtained were used to develop a viscoelastic model. The elastic modulus calculated helps us to determine the main directions of anisotropy on the forearm. METHODS: We use a new in vivo single-axis extension machine (patent no. FR03/09220 application in progress). With it, we can carry out monotonous, creep and relaxation tests on the forearm. An associated finite elements model enables conversion to the intrinsic parameters of the skin under stress and strain from external stress applied in force and displacement. From the tests, we can propose a viscoelastic model and the identification of his parameters. We carried out tests in four directions with respect to the axis of the forearm of 63 people of different ages. The present report is limited to a brief presentation of the experimental set-up used, and a more complete presentation of the viscoelastic model and how it is defined and also the work on the anisotropy in the elastic domain. RESULTS: The viscoelastic model proposed has only four intrinsic parameters: elasticity parameters E(e) and E(ve) and viscosity parameters epsilon(ve) and A. Skin being considered as orthotropic, we were able to determine the average main direction of 63 people, which is of 5.33+/-5.78 around the longitudinal axis of the arm. An average modulus E(1) (ave)=6.57E(5) (Pa) can be found in the direction close to the axis of the arm and E(2) (ave)=1.30E(5) (Pa) in the perpendicular direction and a G(12)=1.32E(5) (Pa) shear modulus. CONCLUSIONS: The parameters obtained with the viscoelastic model are independent of the type of load, the same coefficients enable a correct representation in creep and relaxation tests. The main directions vary from one person to another, Young's modulus in these directions could be an indicator for dermatologists and cosmeticians.


Assuntos
Modelos Biológicos , Movimento/fisiologia , Estimulação Física/instrumentação , Fenômenos Fisiológicos da Pele , Adulto , Idoso , Anisotropia , Simulação por Computador , Elasticidade , Antebraço/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade , Estimulação Física/métodos , Viscosidade
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