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1.
Comput Biol Med ; 63: 11-8, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26001851

RESUMO

INTRODUCTION: Solar cheilosis (SC), a common precancer of the lower lip with a high potential to progress to invasive squamous cell carcinoma, presents with characteristic morphological vermillion-skin border alterations, like the border retraction. AIM: To determine robust macro-morphological descriptors of the vermillion border from non-standardized digital photographs and to exploit a probabilistic model for SC recognition in real clinical environments. METHODS: Lip borders of 150 individuals (75 SC patients, 75 non-SC controls) were quantified on the basis of the extent of vermillion retraction and the degree of border irregularity employing fractal features and type-P Fourier descriptors. Eight lip border quantifiers were evaluated in terms of their reliability and reproducibility. The probabilistic 'diagnostic' model was implemented using the relevance vector machine (RVM) algorithm. RESULTS: Picture acquisition contributes substantially to overall variability of lip border images; however, for the different lip descriptors 33% to 65% of border morphological variability is due to differences among individuals. Different camera operators or the use of cameras with different specifications did not affect significantly the extracted lip features. The proposed RVM probabilistic model yielded a high sensitivity and specificity of 94.6% and 96%, respectively. CONCLUSION: We explored the use of digital photography within the clinical routine setting to validate a probabilistic model for the assessment of lip conditions like SC. The proposed method opens new perspectives toward a cost effective, non-invasive monitoring of SC to support large scale epidemiological and interventional studies in different clinical environments.


Assuntos
Processamento de Imagem Assistida por Computador/métodos , Neoplasias Labiais/patologia , Lábio/patologia , Fotografação , Lesões Pré-Cancerosas/patologia , Máquina de Vetores de Suporte , Feminino , Humanos , Masculino
2.
Electromagn Biol Med ; 34(4): 361-9, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25006865

RESUMO

The electric field effects on conformational properties of trialanine in different halide solutions were explored with long-scale molecular dynamics simulations. NaF, NaCl, NaBr and NaI solutions of low (0.2 M) and high (2 M) concentrations were exposed to a constant electric field of 1000 V/m. Generally, the electric field does not disturb trialanine's structure. Large structural changes appear only in the case of the supersaturated 2.0 M NaF solution containing NaF crystals. Although the electric field affects in a complex way, all the ions-water-peptide interactions, it predominantly affects the electroselectivity effect, which describes specific interactions such as the ion-pair formation.


Assuntos
Brometos/química , Campos Eletromagnéticos , Oligopeptídeos/química , Cloreto de Sódio/química , Compostos de Sódio/química , Fluoreto de Sódio/química , Iodeto de Sódio/química , Halogênios/química , Íons , Simulação de Dinâmica Molecular , Software , Soluções , Água/química
3.
J Biol Phys ; 40(4): 401-12, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25005753

RESUMO

Fourier transform infrared spectroscopy is utilized to examine the effects of increased calcium, vitamin D, and combined calcium-vitamin D supplementation on osteoporotic rabbit bones with induced inflammation. The study includes different bone sites (femur, tibia, humerus, vertebral rib) in an effort to explore possible differences among the sites. We evaluate the following parameters: mineral-to-matrix ratio, carbonate content, and non-apatitic species (labile acid phosphate and labile carbonate) contribution to bone mineral. Results show that a relatively high dose of calcium or calcium with vitamin D supplementation increases the bone mineralization index significantly. On the other hand, vitamin D alone is not as effective in promoting mineralization even with high intake. Mature B-type apatite was detected for the group with calcium supplementation similar to that of aged bone. High vitamin D intake led to increased labile species concentration revealing bone formation. This is directly associated with the suppression of pro-inflammatory cytokines linked to induced inflammation. The latter is known to adversely alter bone metabolism, contributing to the aetiopathogenesis of osteoporosis. Thus, a high intake of vitamin D under inflammation-induced osteoporosis does not promote mineralization but suppresses bone resorption and restores metabolic balance.


Assuntos
Osso e Ossos/efeitos dos fármacos , Cálcio da Dieta/farmacologia , Cálcio/farmacologia , Suplementos Nutricionais/análise , Osteoporose/metabolismo , Espectroscopia de Infravermelho com Transformada de Fourier , Vitamina D/farmacologia , Animais , Apatitas/metabolismo , Osso e Ossos/metabolismo , Relação Dose-Resposta a Droga , Interações Medicamentosas , Feminino , Inflamação/complicações , Osteoporose/etiologia , Coelhos , Vibração
4.
Comput Methods Programs Biomed ; 114(3): 291-301, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24661607

RESUMO

INTRODUCTION: Accurate lip contour identification is demanding since variations in color, form and surface texture, even in normal lips, introduce artifacts in non-adapted segmentation algorithms. Herein, a method for vermilion border detection and quantification in healthy and diseased lower lips is presented. AIM: To quantify the morphological irregularities of lower lip border, to validate its discriminative power in solar cheilosis diagnosis and to provide supportive tools toward, cost effective, non invasive, disease monitoring. MATERIALS: Segmentation algorithm for lower lip border was based on spatial fuzzy c-means clustering algorithm with adaptive selection of fuzzy exponent m. Lip features measuring morphological lip border deviations were estimated. The method of lip border extraction and quantitative description was evaluated in a gold standard set of 25 young volunteers without onset of lip diseases. Quantitative descriptors were evaluated in terms of correct classification rates in differentiating 30 healthy control cases from 41 patients with solar cheilosis and were further applied to quantify the therapeutic outcome after immunocryosurgery in eight patients with solar cheilosis. RESULTS: Adaptive estimation of fuzzy exponent m substantially boosted the segmentation quality in gold standard cases yielding quite smooth lip contours and uniformly low values of lip irregularity features. Discriminant analysis highlighted the distance between the extracted and modeled vermilion border as a feature with excellent diagnostic accuracy (sensitivity and specificity 98% and 93% respectively). Results on patients with solar cheilosis followed up after treatment with immunocryosurgery showed that proposed quantitative lip marker was able to trace the improvement of disease after treatment. CONCLUSION: Correct lip border recognition is the prerequisite for extracting essential morphological descriptors from lips with epithelial diseases like solar cheilosis. In this paper we presented an efficient method for the automatic identification and quantitative description of lower lip vermilion border morphology in health and disease using digital photography and image analysis techniques.


Assuntos
Queilite/diagnóstico , Processamento de Imagem Assistida por Computador/métodos , Doenças Labiais/diagnóstico , Lábio/fisiologia , Lábio/fisiopatologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Algoritmos , Queilite/patologia , Análise por Conglomerados , Criocirurgia , Feminino , Lógica Fuzzy , Humanos , Doenças Labiais/patologia , Masculino , Pessoa de Meia-Idade , Reconhecimento Automatizado de Padrão/métodos , Adulto Jovem
5.
Curr Opin Obstet Gynecol ; 25(1): 3-10, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23108289

RESUMO

PURPOSE OF REVIEW: To highlight the recent advances in cancer genome research and its clinical applications made possible by next-generation sequencing (NGS), with particular emphasis on gynecological and breast cancers is the purpose of the review. RECENT FINDINGS: Through advances in NGS technologies, whole-exome sequencing and whole-genome sequencing (WGS) have been performed on various cancers, identifying in the process numerous recurrent mutations and highly mutated genes. These cancers include uterine serous carcinomas, high-grade serous ovarian adenocarcinomas and breast cancer. In contrast to identifying somatic mutations in sporadic cancers, a far smaller number of studies using NGS have been conducted to identify new causal mutations or genes for hereditary cancer syndromes. In addition to research discovery, diagnostic applications of NGS have also become increasingly evident. Thus, WGS has been applied in a diagnostic context to identify a complex chromosomal rearrangement in a patient with acute myeloid leukemia of unclear subtype. Similarly, the targeted sequencing of panels of known cancer genes using NGS has demonstrated its robustness in the context of identifying known pathological mutations. SUMMARY: The research and clinical applications of cancer genome sequencing have progressed at an unprecedented pace over the last few years, and this promises to be accelerated with new developments of high-throughput NGS technologies and robust analytical tools.


Assuntos
Genoma Humano/genética , Neoplasias/genética , Análise de Sequência de DNA/métodos , Neoplasias da Mama/genética , Feminino , Neoplasias dos Genitais Femininos/genética , Humanos , Mutação/genética , Neoplasias/diagnóstico
7.
Skin Res Technol ; 19(1): e498-506, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23020792

RESUMO

INTRODUCTION: In clinical dermatology, the stabilization of the overall skin condition can be in many cases the earliest qualitative measure of the effectiveness of the therapeutic intervention. Subjective image comparisons, that offer empirical 'qualitative' judgments of degrees of image similarities, are traditionally employed by the involved physicians. OBJECTIVES: To quantify, by means of an image similarity metric, the degree of stabilization of an expanding skin disease, and to identify the situation of 'no further change' of the skin condition of the patient, providing thus the physician with an early, objective measure of the efficacy of the used therapy. METHODS: For treatment assessment, a variant of gray Hausdorff distance metric was employed to compare images of lesional skin segments of a patient, taken at different time points during a therapeutic course. Prior to image comparison, an effective preprocessing scheme was adapted to constrain wide pose and light variations. The proposed similarity algorithm was tested on raw clinical image data sets of patients diagnosed with toxic epidermal necrolysis, a life-threatening condition with rapid evolution. Fine tuning of algorithm's parameters was optimized using Precision-Recall curves. RESULTS: Proposed image comparison method resulted in a high-degree of image similarity (about 96%) between pictures taken at second and fifth day of hospitalization. Current similarity results substantiate a significant agreement between the computer-treatment assessment, by means of image comparison, and the corresponding clinical experts' review of skin condition. CONCLUSION: Objective evidence of 'no further change' situation may provide (a) intuitive clinical decision support to dermatologists in assessing aggressive skin conditions, where the timely evaluation of treatment response is of vital importance and (b) a versatile end-point measure for corresponding therapeutic clinical trials.


Assuntos
Processamento de Imagem Assistida por Computador/métodos , Modelos Biológicos , Reconhecimento Automatizado de Padrão/métodos , Fotografação/métodos , Síndrome de Stevens-Johnson/patologia , Síndrome de Stevens-Johnson/terapia , Algoritmos , Terapia Combinada , Progressão da Doença , Monitoramento de Medicamentos/métodos , Hospitalização , Humanos , Índice de Gravidade de Doença , Resultado do Tratamento
11.
Dermatology ; 224(2): 134-9, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22572593

RESUMO

BACKGROUND: Therapeutic evidence for toxic epidermal necrolysis (TEN) is indicative for high-dose intravenous immunoglobulin yet inconclusive for corticosteroids. OBJECTIVE: To describe the combination of corticosteroids, infliximab and a high-dose intravenous immunoglobulin course for TEN. PATIENTS AND METHODS: In three patients (SCORTEN survival probabilities: 41.7%, 64.2%, 41.7%) disease control was evaluated by (a) employing quantitative image analysis to measure progression of skin detachment and (b) patients' outcome (complete re-epithelization). Published cases of TEN treatments with infliximab were retrieved from PubMed. RESULTS: Within 48 h skin disease progression was arrested in all patients. Two patients were discharged after 3 weeks without any sequels from skin or conjunctivae. One patient passed away on the ninth day, however with noticeably improved skin (mortality rate: 33% observed vs. 50% expected). A PubMed search retrieved five TEN patients treated successfully with infliximab. CONCLUSION: The described combination presents a feasible therapeutic alternative for TEN that warrants further evaluation.


Assuntos
Anticorpos Monoclonais/uso terapêutico , Fármacos Dermatológicos/uso terapêutico , Imunoglobulinas Intravenosas/uso terapêutico , Fatores Imunológicos/uso terapêutico , Síndrome de Stevens-Johnson/tratamento farmacológico , Idoso , Idoso de 80 Anos ou mais , Quimioterapia Combinada , Humanos , Infliximab , Masculino , Pessoa de Meia-Idade , Índice de Gravidade de Doença , Resultado do Tratamento
12.
J Biol Phys ; 38(2): 279-91, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23449289

RESUMO

Osteoporosis is a systemic skeletal disorder associated with reduced bone mineral density and the consequent high risk of bone fractures. Current practice relates osteoporosis largely with absolute mass loss. The assessment of variations in chemical composition in terms of the main elements comprising the bone mineral and its effect on the bone's quality is usually neglected. In this study, we evaluate the ratio of the main elements of bone mineral, calcium (Ca), and phosphorus (P), as a suitable in vitro biomarker for induced osteoporosis. The Ca/P concentration ratio was measured at different sites of normal and osteoporotic rabbit bones using two spectroscopic techniques: Auger electron spectroscopy (AES) and energy-dispersive X-ray spectroscopy (EDX). Results showed that there is no significant difference between samples from different genders or among cortical bone sites. On the contrary, we found that the Ca/P ratio of trabecular bone sections is comparable to cortical sections with induced osteoporosis. Ca/P ratio values are positively related to induced bone loss; furthermore, a different degree of correlation between Ca and P in cortical and trabecular bone is evident. This study also discusses the applicability of AES and EDX to the semiquantitative measurements of bone mineral's main elements along with the critical experimental parameters.

13.
J Biol Phys ; 38(4): 623-35, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24615224

RESUMO

A model of osteoporosis based on induced inflammation (IMO) was applied on rabbit bones. The structural heterogeneity and molecular complexity of bone significantly affect bone mechanical properties. A tool like Fourier transform infrared spectroscopy, able to analyze both the inorganic and organic phase simultaneously, could provide compositional information regarding cortical and trabecular sections under normal and osteoporotic conditions. In this study, we assessed the mineral/matrix ratio, carbonate and phosphate content and labile (i.e., non-apatitic) species contribution to bone mineral and collagen cross-linking patterns. Clear differences were observed between cortical and trabecular bone regarding mineral and carbonate content. Induced inflammation lowers the mineral/matrix ratio and increases the overall carbonate accumulation. Elevated concentrations of labile species were detected in osteoporotic samples, especially in the trabecular sections. Collagen cross-linking patterns were indirectly observed through the 1660/1690 cm⁻¹ ratio in the amide I band and a positive correlation was found with the mineralization index. Principal component analysis (PCA) applied to female samples successfully clustered trabecular and osteoporotic cases. The important role played by the phosphate ions was confirmed by corresponding loadings plots. The results suggest that the application of the IMO model to rabbit bones effectively alters bone remodeling and forms an osteoporotic bone matrix with a dissimilar composition compared to the normal one.


Assuntos
Osteoporose/metabolismo , Espectroscopia de Infravermelho com Transformada de Fourier , Animais , Densidade Óssea , Colágeno/metabolismo , Feminino , Inflamação/complicações , Masculino , Análise Multivariada , Osteoporose/complicações , Osteoporose/fisiopatologia , Fosfatos/metabolismo , Coelhos
14.
ScientificWorldJournal ; 11: 520-8, 2011 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-21380486

RESUMO

Biometrics has become an emerging field of technology due to its intrinsic security features concerning the identification of individuals by means of measurable biological characteristics. Two of the most promising biometric modalities are iris and retina recognition, which primarily use nonionizing radiation in the infrared region. Illumination of the eye is achieved by infrared light emitting diodes (LEDs). Even if few LED sources are capable of causing direct eye damage as they emit incoherent light, there is a growing concern about the possible use of LED arrays that might pose a potential threat. Exposure to intense coherent infrared radiation has been proven to have significant effects on living tissues. The purpose of this study is to explore the biological effects arising from exposing the eye to near infrared radiation with reference to international legislation.


Assuntos
Biometria/instrumentação , Olho/efeitos da radiação , Raios Infravermelhos/efeitos adversos , Segurança , Humanos , Modelos Teóricos , Doses de Radiação
16.
ScientificWorldJournal ; 10: 402-12, 2010 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-20209386

RESUMO

Bone is a highly complex, composite tissue and its properties normally vary with age, type, and disorders. Fourier transform infrared spectroscopy and energy-dispersive X-ray spectroscopy techniques were used to study the effect of bone sites and sex to mineral and matrix content and composition. The results show that in rats, all inorganic phases consist of poorly crystalline B-type carbonated apatite, while overall mineralization and carbonate content is virtually unaffected among samples. Statistically significant differences were detected for the nonapatitic environments of acid phosphate and carbonate content. The mean values for the Ca/P ratio point to an increasing trend from tibia to forearm, and to femoral sections.


Assuntos
Osso e Ossos/química , Animais , Osso e Ossos/ultraestrutura , Feminino , Masculino , Microscopia Eletrônica de Varredura , Ratos , Ratos Wistar , Espectroscopia de Infravermelho com Transformada de Fourier
17.
J Biol Phys ; 34(1-2): 39-49, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19669491

RESUMO

Bone collagen structure in normal and pathological tissues is presented using techniques of thin section transmission electron microscopy and morphometry. In pathological tissue, deviations from normal fine structure are reflected in abnormal arrangements of collagen fibrils and abnormalities in fibril diameter. The relationships between these bone structural changes and the skeletal calcium/phosphorus ratio are discussed. Calcium/phosphorus ratio is measured by X-ray absorptiometry and computed microtomography.

18.
ScientificWorldJournal ; 6: 1109-13, 2006 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-16951903

RESUMO

The collagen fibril diameter was measured in cortical bone samples from the femoral neck, rear and front tibia of female and male rats and rabbits using electron microscopy analysis. In most cases, statistically significant differences in mean fibril diameter values between different bone sites were detected. The order of magnitude for the above structural parameter was the same for both genders in both experimental species. In rats, the greatest mean diameter value was that for the femoral, while in rabbits, the one for the rear tibia demonstrating a dependence on bone use and life style. An important aspect was the agreement between these observations and the mean values for Ca/P ratio, as observed in previous experiments, in the same bone sites and animals. Collagen fibril diameter and Ca/P ratio can both serve as indexes of bone quality.


Assuntos
Osso e Ossos/química , Colágeno/ultraestrutura , Animais , Cálcio/análise , Feminino , Colo do Fêmur/química , Masculino , Microscopia Eletrônica , Fósforo/análise , Coelhos , Ratos , Ratos Wistar , Tíbia/química
19.
Micron ; 36(7-8): 593-601, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-16209926

RESUMO

Bone collagen structure in normal and pathological tissues is illustrated using techniques of thin section transmission electron microscopy and computer-assisted analysis. The normal bone collagen types, fibril architecture and diameter are described. In pathological tissue, deviations from normal fine structure are reflected in abnormal arrangements of collagen fibrils and abnormalities in fibril diameter. Computer analyses of normal fibril positive staining patterns are presented in order to provide a basis for comparing such patterns with pathological ones.


Assuntos
Osso e Ossos/ultraestrutura , Colágeno/fisiologia , Colágeno/ultraestrutura , Animais , Doenças Ósseas/patologia , Doenças Ósseas/fisiopatologia , Osso e Ossos/química , Osso e Ossos/fisiologia , Colágeno/análise , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Microscopia Eletrônica de Transmissão , Osteoporose/patologia , Osteoporose/fisiopatologia , Tíbia/química , Tíbia/fisiologia , Tíbia/ultraestrutura
20.
Micron ; 36(7-8): 703-5, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-16182541

RESUMO

The collagen fibril diameter was measured in cortical bone samples from the femoral neck, rear and front tibia of rats using electron microscopy analysis. Statistically significant differences (0.001

Assuntos
Colágeno/ultraestrutura , Colo do Fêmur/ultraestrutura , Tíbia/ultraestrutura , Animais , Colágeno/análise , Interpretação Estatística de Dados , Colo do Fêmur/química , Masculino , Microscopia Eletrônica , Ratos , Ratos Wistar , Tíbia/química
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