RESUMO
Mung bean contains up to 32.6% protein and is one of the great sources of plant-based protein. Because many allergens also function as defense-related proteins, it is important to determine their abundance levels in the high-yielding, disease-resistant cultivars. In this study, for the first time, we compared the seed proteome of high-yielding mung bean cultivars developed by a conventional breeding approach. Using a label-free quantitative proteomic platform, we successfully identified and quantified a total of 1373 proteins. Comparative analysis between the high-yielding disease-resistant cultivar (MC5) and the other three cultivars showed that a total of 69 common proteins were significantly altered in their abundances across all cultivars. Bioinformatic analysis of these altered proteins demonstrated that PDF1 (a defensin-like protein) exhibited high sequence similarity and epitope matching with the established peanut allergens, indicating a potential mung bean allergen that showed a cultivar-specific response. Conversely, known mung bean allergen proteins such as PR-2/PR-10 (Vig r 1), Vig r 2, Vig r 4, LTP1, ß-conglycinin, and glycinin G4 showed no alternation in the MC5 compared to other cultivars. Taken together, our findings suggest that the known allergen profiles may not be impacted by the conventional plant breeding method to develop improved mung bean cultivars.
RESUMO
The study aimed to assess the level of potentially toxic elements (As, Cd, Pb, Zn, Cu, Cr, Mn, and Ni) and associated health implications through commonly consumed rice cultivars of Bangladesh available in Capital city, Dhaka. The range of As, Cd, Pb, Zn, Cu, Cr, Mn, and Ni in rice grains were 0.04-0.35, 0.01-0.15, 0.01-1.18, 10.74-34.35, 1.98-13.42, 0.18-1.43, 2.51-22.08, and 0.21-5.96 mg/kg fresh weight (FW), respectively. The principal component analysis (PCA) identified substantial anthropogenic activities to be responsible for these elements in rice grains. The estimated daily intake (EDI) of the elements was below the maximum tolerable daily intake (MTDI) level. The hazard index (HI) was above the threshold level, stating non-carcinogenic health hazards from consuming these rice cultivars. The mean target cancer risk (TCR) of As and Pb exceeded the USEPA acceptable level (10-6), revealing carcinogenic health risks from the rice grains.
Assuntos
Oryza , Bangladesh/epidemiologia , Oryza/química , Humanos , Contaminação de Alimentos/análise , Carcinógenos/análise , Carcinógenos/toxicidade , Metais Pesados/análise , Metais Pesados/toxicidade , Análise de Componente PrincipalRESUMO
Bronchogenic cyst results from abnormal bronchial budding. Thin-stalked mobile bronchogenic cysts are rare and sometimes radiologically mimic mass lesion, making preoperative diagnosis difficult. We present a 12-year-old boy with a preoperative diagnosis of intraparenchymal cystic lung lesion misled by radiology. We performed a mini-thoracotomy revealing a thin stalked mobile elongated cyst that arose from the right inferior pulmonary ligament, confirmed as a bronchogenic cyst in histopathology.
RESUMO
Rice (Oryza sativa L.) is the principal staple food, a fundamental component of food security, a significant source of energy and major nutrients, and a key player in the overall nutritional status in Bangladesh. Parboiling is a common rice-processing treatment in Bangladesh. Recently, polishing has also become a common practice among millers seeking to attract consumers. Polishing may influence the nutrient composition of rice. The present study aimed to investigate the impact of parboiling and polishing on the nutritional content of the five High Yield Varieties (HYVs) of rice (BR11, BRRI dhan28, BRRI dhan29, BRRI dhan49, and BRRI dhan84) and their percent contributions to the Recommended Dietary Allowances (RDA) of vitamins and minerals. All of the rice samples were analyzed for proximate parameters, vitamins (B1, B2, B3, B6, and folate), and minerals (Ca, Mg, Fe, Zn, Na, K, P). Moisture, ash, fat, and total dietary fiber (TDF) were determined gravimetrically, according to the AOAC Official Methods; protein was measured by the Kjeldahl method; B-group vitamins were measured using Ultra Pressure Liquid Chromatography; and mineral content was determined by ICP-OES. The energy, protein, fat, and total dietary fiber (TDF) content of the samples ranged between 342-357 kcal/100 g, 6.79-10.74 g/100 g, 0.31-1.69 g/100 g, and 2.59-3.92 g/100 g respectively. Thiamin, riboflavin, niacin, pyridoxin, and folate content ranged from 0.11-0.25 mg/100 g, 0.01-0.05 mg/100 g, 2.82-6.42 mg/100 g, 0.12-0.30 g/100 g, and 5.40-23.95 g/100 g respectively. In a comparison of parboiling and polishing, macronutrients and vitamin retention were higher in parboiled unpolished rice than in polished unparboiled rice. The minerals (mg/100 g) Ca, Mg, Fe, Zn, Na, K, and P were in the ranges 32.82-44.72, 30.69-58.34, 0.51-0.70,1.83-2.79, 5.00-5.36, 106.49-112.73, and 162.23-298.03. Minerals of BRRI dhan84 were unaffected by polishing and parboiling. BRRI dhan84 contributed a higher percentage of RDA of all B vitamins and minerals. Therefore, to reduce nutrient loss in rice, industries and consumers should be encouraged to avoid polishing or limit polishing to 10% DOM and to consume unpolished rice, either parboiled or unparboiled.
RESUMO
Human diseases may be modeled in animals to allow preclinical assessment of putative new clinical interventions. Recent, highly publicized failures of large clinical trials called into question the rigor, design, and value of preclinical assessment. We established the Stroke Preclinical Assessment Network (SPAN) to design and implement a randomized, controlled, blinded, multi-laboratory trial for the rigorous assessment of candidate stroke treatments combined with intravascular thrombectomy. Efficacy and futility boundaries in a multi-arm multi-stage statistical design aimed to exclude from further study highly effective or futile interventions after each of four sequential stages. Six independent research laboratories performed a standard focal cerebral ischemic insult in five animal models that included equal numbers of males and females: young mice, young rats, aging mice, mice with diet-induced obesity, and spontaneously hypertensive rats. The laboratories adhered to a common protocol and efficiently enrolled 2615 animals with full data completion and comprehensive animal tracking. SPAN successfully implemented treatment masking, randomization, prerandomization inclusion and exclusion criteria, and blinded assessment of outcomes. The SPAN design and infrastructure provide an effective approach that could be used in similar preclinical, multi-laboratory studies in other disease areas and should help improve reproducibility in translational science.
Assuntos
AVC Isquêmico , Acidente Vascular Cerebral , Feminino , Humanos , Masculino , Ratos , Animais , Camundongos , Roedores , Laboratórios , Reprodutibilidade dos Testes , Acidente Vascular Cerebral/terapiaRESUMO
Machine learning applications are widespread due to straightforward supervised learning of known data labels. Many data samples in real-world scenarios, including medicine, are unlabeled because data annotation can be time-consuming and error-prone. The application and evaluation of unsupervised clustering methods are not trivial and are limited to traditional methods (e.g., k-means) when clinicians demand deeper insights into patient data beyond classification accuracy. The contribution of this paper is three-fold: 1) to introduce a patient stratification strategy based on a clinical variable instead of a diagnostic label, 2) to evaluate clustering performance using within-cluster homogeneity and between-cluster statistical difference, and 3) to compare widely used traditional clustering algorithms (e.g., k-means) with a state-of-the-art deep learning solution for clustering tabular data. The deep clustering method achieves superior within-cluster homogeneity and between-cluster separation compared to k-means and identifies three statistically distinct and clinically interpretable high blood pressure patient clusters. The proposed clustering strategy and evaluation metrics will facilitate the stratification of large patient cohorts in health science research without requiring explicit diagnostic labels.
RESUMO
Pulmonary agenesis is a rare disorder, and the right-sided one is much rarer. Most of the cases are diagnosed during early life. Because of rarity, it can be misdiagnosed and even more challenging to diagnose when presented during adult life. However, we report a rare late manifestation of right-sided unilateral lung agenesis in a 22-year-old female patient who was treated for pneumonia several times, the first reported case from Bangladesh. We also highlighted the diagnostic approach of the case in low-resource settings.
RESUMO
Cerebral ischemia and reperfusion initiate cellular events in brain that lead to neurological disability. Investigating these cellular events provides ample targets for developing new treatments. Despite considerable work, no such therapy has translated into successful stroke treatment. Among other issues-such as incomplete mechanistic knowledge and faulty clinical trial design-a key contributor to prior translational failures may be insufficient scientific rigor during preclinical assessment: nonblinded outcome assessment; missing randomization; inappropriate sample sizes; and preclinical assessments in young male animals that ignore relevant biological variables, such as age, sex, and relevant comorbid diseases. Promising results are rarely replicated in multiple laboratories. We sought to address some of these issues with rigorous assessment of candidate treatments across 6 independent research laboratories. The Stroke Preclinical Assessment Network (SPAN) implements state-of-the-art experimental design to test the hypothesis that rigorous preclinical assessment can successfully reduce or eliminate common sources of bias in choosing treatments for evaluation in clinical studies. SPAN is a randomized, placebo-controlled, blinded, multilaboratory trial using a multi-arm multi-stage protocol to select one or more putative stroke treatments with an implied high likelihood of success in human clinical stroke trials. The first stage of SPAN implemented procedural standardization and experimental rigor. All participating research laboratories performed middle cerebral artery occlusion surgery adhering to a common protocol and rapidly enrolled 913 mice in the first of 4 planned stages with excellent protocol adherence, remarkable data completion and low rates of subject loss. SPAN stage 1 successfully implemented treatment masking, randomization, prerandomization inclusion/exclusion criteria, and blinded assessment to exclude bias. Our data suggest that a large, multilaboratory, preclinical assessment effort to reduce known sources of bias is feasible and practical. Subsequent SPAN stages will evaluate candidate treatments for potential success in future stroke clinical trials using aged animals and animals with comorbid conditions.
Assuntos
Isquemia Encefálica , Acidente Vascular Cerebral , Idoso , Animais , Encéfalo , Isquemia Encefálica/terapia , Estudos de Viabilidade , Humanos , Infarto da Artéria Cerebral Média/terapia , Masculino , Camundongos , Acidente Vascular Cerebral/terapiaRESUMO
Ultraviolet (UV) radiation is known to cause an imbalance of the endogenous antioxidant system leading to an increase in skin cancer. Panax quinquefolium (American ginseng) polysaccharides (GPS) can inhibit such an imbalance due to its anti-oxidative and anti-inflammatory properties. The aim of this study was to investigate the therapeutic effects of topical formulations containing GPS nanoparticles (NPs) to inhibit UVB induced oxidative damage and skin cancer. Photoaging was conducted under UVB irradiation with a dose of 300 mJ/cm2 on SKH1 hairless mice. The treatment groups (n = 5) were as follows: sham control, native GPS, GPS NPs and fluorescent labeled GPS NPs. To compare the photoprotective performance, the topical formulations were applied before and after UVB induction (pre-treatment and post-treatment), followed by sacrificing the animals. Then, skin and blood samples were collected, and inflammatory cytokines production was measured using ELISA. Compared to the sham control, GPS NPs pre-treated mice skin and blood samples exhibited a significant lowering in all cytokine production. In addition, skin histology analysis showed that pre-treatment of GPS NPs prevented epidermal damage and proliferation. The results support that topical formulation containing GPS NPs can inhibit UVB induced oxidative damage and skin cancer.
Assuntos
Nanomedicina , Nanopartículas/administração & dosagem , Nanopartículas/uso terapêutico , Panax/química , Polissacarídeos/uso terapêutico , Neoplasias Cutâneas/tratamento farmacológico , Raios Ultravioleta , Administração Cutânea , Animais , Citocinas/metabolismo , Dano ao DNA , Feminino , Camundongos Pelados , Nanopartículas/ultraestrutura , Tamanho da Partícula , Polissacarídeos/administração & dosagem , Pele/patologiaRESUMO
Here, we present the proteome profiling of low-molecular weight (<50â¯kDa) proteins of seven different lentil cultivars developed by Bangladesh Agricultural Research Institute. A total of 2873 peptides corresponding to 180 unique proteins were identified wherein >24% of them were described lentil allergens. Comparative relative quantitation showed differences in protein abundance of major allergen proteins such as Len c 1.0101, Len c 1.0102, and lipid transfer proteins (LTPs), indicating qualitative and quantitative variations in allergen proteins in lentil cultivars. In this report, for the first-time, the amino acid sequence of LTPs in lentil has been confirmed by high resolution mass spectrometry. In addition, ideal peptides of Len c 1.0101, Len c 1.0102, and LTPs allergens were further determined with multiple reaction monitoring (MRM) analysis. Therefore, this data could provide a great resource for further development of targeted, proteomics-based assays for quantification of lentil allergens.
Assuntos
Alérgenos/análise , Lens (Planta)/metabolismo , Proteínas de Plantas/análise , Proteômica/métodos , Alérgenos/química , Alérgenos/imunologia , Sequência de Aminoácidos , Bangladesh , Cromatografia Líquida de Alta Pressão , Peso Molecular , Proteínas de Plantas/química , Proteínas de Plantas/imunologia , Alinhamento de Sequência , Espectrometria de Massas em TandemRESUMO
Plant polysaccharides (PS) such as American ginseng polysaccharide (GPS) have drawn immense interest in the field of immunoengineering, as they offer a way to actively control immune cell behavior and stimulation. These pharmacological activities have been limited by PS's inherent physicochemical properties including large molecular size, heterogeneity, and poor solubility. In this work, we hypothesized that by nanosizing and encapsulating GPSs, we could enhance their immunomodulation by increased penetration and absorption through the GI tract. Herein, GPS nanoparticles (NPs) of average size 20 nm (± 4 nm) were prepared using a microfluidic approach, then encapsulated within porous nanospheres (diameter 180 ± 10 nm) of biodegradable gelatin to enhance their oral delivery. To locate the GPS NPs inside the gelatin, we encapsulated fluorescent-labeled GPS in gelatin and analyzed using confocal microscopy. An in vitro investigation on tumor induced macrophage cell lines showed a concentration dependent enhanced immunostimulation with the encapsulated GPS NPs. The immunomodulation was then studied for different formulations of GPS through oral gavage in Swiss albino mice. The results showed that the production of proinflammatory mediators in blood samples was significantly increased for the encapsulated GPS in a dose- and time-dependent manner compared to other GPS treatments. This study shows that GPS and potentially other PS systems' immunomodulation properties can be significantly enhanced for use in simple oral drug delivery.
RESUMO
Polysaccharides are a major active component of American ginseng root showing various biological activities including anti-carcinogenic, anti-aging, immunostimulatory and antioxidant effects. Although their biological activity has been reported by several groups, no research has explored their cellular uptake and biodistribution, owing to the lack of suitable detection techniques in living cells. This work examines a novel, simple and efficient fluorescent labeling procedure of ginseng polysaccharides (PS), in order to examine their cellular distribution using confocal microscopy. This procedure utilized a one-pot strategy with fluorescein-5-thiosemicarbazide (FTSC) to introduce a thiosemicarbazide group onto the aldehyde group at the reducing saccharide end to form a stable amino derivative through reductive amination. This polysaccharide-FTSC derivative was then characterized by GPC, UV, FTIR, photoluminescence and fluorescence microscopy to confirm attachment and any structural changes. The results demonstrated that the labeled ginseng PS nanostructure showed high fluorescence with minimal changes in PS molecular weight. The labeled PS exhibited almost no cytotoxicity effect against tumor induced macrophage cell lines (RAW 264.7) while retaining high immunostimulating activity similar to the non-labeled ginseng PS. Therefore, the developed approach provides a convenient and highly efficient fluorescent labeling procedure for understanding the mechanism of ginseng PS uptake in macrophage cell lines.
Assuntos
Fatores Imunológicos/química , Fatores Imunológicos/farmacologia , Nanopartículas/química , Panax/química , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Polissacarídeos/química , Polissacarídeos/farmacologia , Animais , Sobrevivência Celular/efeitos dos fármacos , Citocinas/metabolismo , Corantes Fluorescentes , Macrófagos/efeitos dos fármacos , Macrófagos/imunologia , Macrófagos/metabolismo , Camundongos , Imagem Molecular , Nanopartículas/ultraestrutura , Óxido Nítrico/metabolismo , Células RAW 264.7 , Espectroscopia de Infravermelho com Transformada de Fourier , Coloração e RotulagemRESUMO
BACKGROUND: Our present study was conducted to characterize the phytoconstituents present in the aqueous extract of Momordica charantia and evaluate the antimicrobial efficacy of silver-extract nanoparticles (Ag-Extract-NPs). METHODS: Silver nanoparticles (AgNPs) were prepared by reducing AgNO3; and NaBH4 served as reducing agent. After screening of phytochemicals; AgNPs and aqueous extract were mixed thoroughly and then coated by polyaniline. These NPs were characterized by using Visual inspection, UV spectroscopy, FTIR, SEM and TEM techniques. Antimicrobial activities were assessed against Staphylococcus aureus, Salmonella typhi, Escherichia coli and Pseudomonas aeruginosa. RESULTS: Aqueous extract of M. charantia fruits contain alkaloid, phenol, saponin etc. UV-Vis spectrum showed strong absorption peak around 408 nm. The presence of -CH, -NH, -COOH etc. stretching in FTIR spectrum of Ag-Extract-NPs endorsed that AgNPs were successfully capped by bio-compounds. SEM and TEM result revealed that synthesized NPs had particle size 78.5-220 nm. Ag-Extract-NPs showed 34.6 ± 0.8 mm zone of inhibition against E. coli compared to 25.6 ± 0.5 mm for ciprofloxacin. Maximum zone of inhibition for Ag-Extract-NPs were 24.8 ± 0.7 mm, 26.4 ± 0.4 mm, 7.4 ± 0.4 mm for S. aureus, P. aeruginosa and S. typhi. We found that Ag-Extract-NPs have much better antibacterial efficacy than AgNPs and M. charantia extract has individually. It is also noticed that gram negative bacteria (except S. typhi) are more susceptible to Ag-Extract-NPs than gram positive bacteria. CONCLUSION: Ag-Extract-NPs showed strong antibacterial activity. In order to make a reliable stand for mankind, further study is needed to consider determining the actual biochemical pathway by which AgNPs-extracts exert their antimicrobial effect.
Assuntos
Antibacterianos/química , Antibacterianos/farmacologia , Momordica charantia/metabolismo , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Prata/farmacologia , Antibacterianos/metabolismo , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Momordica charantia/química , Nanopartículas/química , Nanopartículas/metabolismo , Extratos Vegetais/metabolismo , Prata/química , Prata/metabolismoRESUMO
North American (NA) ginseng root (Panax quinquefolium) has become of increasing scientific interest because of its immune-enhancing properties. Herein, we have developed a novel approach to synthesize ginseng polysaccharide nanoparticles (NPs) from NA ginseng for enhancing their immunostimulation. Nanoparticles of ginseng polysaccharide were prepared using a microfluidic device and compared to other conventional wet chemical processes including nanoprecipitation and reverse microemulsion. The morphology and size of the NPs were characterized by SEM, TEM, DLS and FTIR. Depending on the experimental conditions, microfluidics was found to provide unimodal polysaccharide spheres down to 20 nm (±4 nm) with very narrow particle size distributions. In addition, the immunostimulating effect of the polysaccharide NPs was investigated on Murine macrophage cell lines, with the results revealing an enhanced production of all proinflammatory mediators in a concentration dependent manner. The proposed microfluidic system has the advantages of ease of fabrication, simplicity, and a fast and low-cost process that is capable of producing ginseng polysaccharide NPs with demonstrated enhancement of immunostimulation of macrophage cell lines.
RESUMO
Fractional anisotropy (FA) was examined in a priori selected fiber tracts in individuals with schizophrenia (n=25) and their non-psychotic siblings (n=29) versus controls (n=35). FA was reduced in a portion of the fornix in individuals with schizophrenia (although this did not survive correction for the number of tracts investigated). FA in the siblings did not differ from that in controls in any of the investigated tracts.
Assuntos
Anisotropia , Fórnice/patologia , Esquizofrenia/patologia , Irmãos , Adulto , Estudos de Casos e Controles , Imagem de Tensor de Difusão , Feminino , Humanos , Processamento de Imagem Assistida por Computador/métodos , Imageamento por Ressonância Magnética , MasculinoRESUMO
BACKGROUND: Alterations of the gray and white matter have been identified in Alzheimer's disease (AD) by structural magnetic resonance imaging (MRI) and diffusion tensor imaging (DTI). However, whether the combination of these modalities could increase the diagnostic performance is unknown. METHODS: Participants included 19 AD patients, 22 amnestic mild cognitive impairment (aMCI) patients, and 22 cognitively normal elderly (NC). The aMCI group was further divided into an "aMCI-converter" group (converted to AD dementia within 3 years), and an "aMCI-stable" group who did not convert in this time period. A T(1)-weighted image, a T(2) map, and a DTI of each participant were normalized, and voxel-based comparisons between AD and NC groups were performed. Regions-of-interest, which defined the areas with significant differences between AD and NC, were created for each modality and named "disease-specific spatial filters" (DSF). Linear discriminant analysis was used to optimize the combination of multiple MRI measurements extracted by DSF to effectively differentiate AD from NC. The resultant DSF and the discriminant function were applied to the aMCI group to investigate the power to differentiate the aMCI-converters from the aMCI-stable patients. RESULTS: The multi-modal approach with AD-specific filters led to a predictive model with an area under the receiver operating characteristic curve (AUC) of 0.93, in differentiating aMCI-converters from aMCI-stable patients. This AUC was better than that of a single-contrast-based approach, such as T(1)-based morphometry or diffusion anisotropy analysis. CONCLUSION: The multi-modal approach has the potential to increase the value of MRI in predicting conversion from aMCI to AD.
RESUMO
We have developed a new method to provide a comprehensive quantitative analysis of brain anatomy in cerebral palsy patients, which makes use of two techniques: diffusion tensor imaging and automated 3D whole brain segmentation based on our brain atlas and a nonlinear normalization technique (large-deformation diffeomorphic metric mapping). This method was applied to 13 patients and normal controls. The reliability of the automated segmentation revealed close agreement with the manual segmentation. We illustrate some potential applications for individual characterization and group comparison. This technique also provides a framework for determining the impact of various neuroanatomic features on brain functions.
Assuntos
Atlas como Assunto , Encéfalo/patologia , Paralisia Cerebral/patologia , Imageamento por Ressonância Magnética/métodos , Mapeamento Encefálico/métodos , Criança , Pré-Escolar , Interpretação Estatística de Dados , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Masculino , Dinâmica não Linear , Variações Dependentes do ObservadorRESUMO
Tractography based on diffusion tensor imaging (DTI) is widely used to quantitatively analyze the status of the white matter anatomy in a tract-specific manner in many types of diseases. This approach, however, involves subjective judgment in the tract-editing process to extract only the tracts of interest. This process, usually performed by manual delineation of regions of interest, is also time-consuming, and certain tracts, especially the short cortico-cortical association fibers, are difficult to reconstruct. In this paper, we propose an automated approach for reconstruction of a large number of white matter tracts. In this approach, existing anatomical knowledge about tract trajectories (called the Template ROI Set or TRS) were stored in our DTI-based brain atlas with 130 three-dimensional anatomical segmentations, which were warped non-linearly to individual DTI data. We examined the degree of matching with manual results for selected fibers. We established 30 TRSs to reconstruct 30 prominent and previously well-described fibers. In addition, TRSs were developed to delineate 29 short association fibers that were found in all normal subjects examined in this paper (N=20). Probabilistic maps of the 59 tract trajectories were created from the normal subjects and were incorporated into our image analysis tool for automated tract-specific quantification.
Assuntos
Algoritmos , Imagem de Tensor de Difusão/métodos , Interpretação de Imagem Assistida por Computador/métodos , Modelos Anatômicos , Modelos Neurológicos , Fibras Nervosas Mielinizadas/ultraestrutura , Vias Neurais/anatomia & histologia , Adulto , Simulação por Computador , Feminino , Humanos , Aumento da Imagem/métodos , Masculino , Reprodutibilidade dos Testes , Sensibilidade e EspecificidadeRESUMO
Quantification of normal brain maturation is a crucial step in understanding developmental abnormalities in brain anatomy and function. The aim of this study was to develop atlas-based tools for time-dependent quantitative image analysis, and to characterize the anatomical changes that occur from 2years of age to adulthood. We used large deformation diffeomorphic metric mapping to register diffusion tensor images of normal participants into the common coordinates and used a pre-segmented atlas to segment the entire brain into 176 structures. Both voxel- and atlas-based analyses reported a structure that showed distinctive changes in terms of its volume and diffusivity measures. In the white matter, fractional anisotropy (FA) linearly increased with age in logarithmic scale, while diffusivity indices, such as apparent diffusion coefficient (ADC), and axial and radial diffusivity, decreased at a different rate in several regions. The average, variability, and the time course of each measured parameter are incorporated into the atlas, which can be used for automated detection of developmental abnormalities. As a demonstration of future application studies, the brainstem anatomy of cerebral palsy patients was evaluated and the altered anatomy was delineated.
Assuntos
Atlas como Assunto , Automação , Encéfalo/anatomia & histologia , Encéfalo/crescimento & desenvolvimento , Imagem de Tensor de Difusão/métodos , Processamento de Imagem Assistida por Computador/métodos , Adolescente , Adulto , Anisotropia , Encéfalo/patologia , Criança , Pré-Escolar , Diagnóstico por Computador/métodos , Difusão , Feminino , Humanos , Modelos Lineares , Masculino , Fibras Nervosas Mielinizadas/patologia , Tamanho do Órgão , Fatores de Tempo , Adulto JovemRESUMO
The purpose of this paper is to establish single-participant white matter atlases based on diffusion tensor imaging. As one of the applications of the atlas, automated brain segmentation was performed and the accuracy was measured using Large Deformation Diffeomorphic Metric Mapping (LDDMM). High-quality diffusion tensor imaging (DTI) data from a single-participant were B0-distortion-corrected and transformed to the ICBM-152 atlas or to Talairach coordinates. The deep white matter structures, which have been previously well documented and clearly identified by DTI, were manually segmented. The superficial white matter areas beneath the cortex were defined, based on a population-averaged white matter probability map. The white matter was parcellated into 176 regions based on the anatomical labeling in the ICBM-DTI-81 atlas. The automated parcellation was achieved by warping this parcellation map to normal controls and to Alzheimer's disease patients with severe anatomical atrophy. The parcellation accuracy was measured by a kappa analysis between the automated and manual parcellation at 11 anatomical regions. The kappa values were 0.70 for both normal controls and patients while the inter-rater reproducibility was 0.81 (controls) and 0.82 (patients), suggesting "almost perfect" agreement. A power analysis suggested that the proposed method is suitable for detecting FA and size abnormalities of the white matter in clinical studies.