RESUMO
OBJECTIVES: The aim of the study was to evaluate clinical, endoscopic, radiologic, and histopathological features helpful in differentiating Crohn disease (CD) from intestinal tuberculosis (ITB) in children. METHODS: Patients diagnosed to have CD or ITB based on standard recommended criteria were enrolled. Children with inflammatory bowel disease unclassified or suspected ITB or CD with incomplete work-up or lost to follow-up were excluded. The clinical and laboratory (radiology, endoscopy, and histology) details of children were analyzed. RESULTS: Twenty cases of ITB (14 [3-17] years) and 23 of CD (11 [1-17] years) were enrolled. Presentation with chronic diarrhea (82% vs 40%; Pâ=â0.006) and blood in stool (74% vs 10%; Pâ=â0.001) favored CD, whereas subacute intestinal obstruction (20% vs 0%; Pâ=â0.04) and ascites (30% vs 0%; Pâ=â0.005) favored ITB. Presence of deep ulcers (61% vs 30%; Pâ=â0.04), longitudinal ulcers (48% vs 15%; Pâ=â0.02), involvement of multiple colonic segments (70% vs 35%; Pâ=â0.02), left-sided colon (87% vs 40%; Pâ=â0.003), extraintestinal manifestations (21.7% vs 0%; Pâ=â0.02), and higher platelet count (3.9 vs 2.6â×â10/mm; Pâ=â0.02) favored CD. Isolated ileocecal involvement (40% vs 8.7%; Pâ=â0.03) was a feature of ITB. TB bacilli were demonstrated in 40% ITB cases (colon-6, ascites-1, abdominal lymph node-1). On multivariate analysis, presence of blood in stool (odds ratio: 37.5 [confidence interval: 3.85-365.72], Pâ=â0.002) and left-sided colonic involvement (odds ratio: 16.2 [confidence interval: 1.63-161.98], Pâ=â0.02) were independent predictors of CD. CONCLUSIONS: Microbiologic confirmation of tuberculosis is possible in 40% ITB cases. Presence of blood in stool and left-sided colonic involvement are the most important features favoring CD.
Assuntos
Doenças do Ceco/diagnóstico , Doenças do Colo/diagnóstico , Doença de Crohn/diagnóstico , Doenças do Íleo/diagnóstico , Tuberculose Gastrointestinal/diagnóstico , Adolescente , Doenças do Ceco/patologia , Criança , Pré-Escolar , Doenças do Colo/patologia , Doença de Crohn/patologia , Diagnóstico Diferencial , Endoscopia Gastrointestinal , Feminino , Seguimentos , Humanos , Doenças do Íleo/patologia , Lactente , Modelos Logísticos , Masculino , Radiografia , Estudos Retrospectivos , Tuberculose Gastrointestinal/patologiaRESUMO
PURPOSE: Arterial spin labeling (ASL) is a noninvasive magnetic resonance (MR) perfusion technique to detect changes in blood flow. This study was undertaken to obtain a reference set of normal values of cerebral blood flow (CBF) in different age groups using three-dimensional pseudocontinuous ASL (3D PCASL) technique. The existence of an age-related decline in the gray matter (GM) and white matter (WM) CBF was evaluated. The gender-related CBF was also analyzed. MATERIALS AND METHODS: One hundred and sixty normal volunteers of varying age (6-72 years), arranged in 4 age groups, underwent MR perfusion imaging using 3D PCASL technique at 3 Tesla (T). Mean CBF values in global and regional GM and WM in different age groups were extracted from the quantitative perfusion map. RESULTS: A significant negative correlation was observed between the age and mean GM and WM CBF values (r = -0.80, P = 0.001; r = -0.59, P = 0.001, respectively). Similar results were also observed between age and various regional mean GM and WM CBF values (P = 0.001). No significant effect of gender on the GM CBF and WM CBF was found in any age group (P > 0.05). CONCLUSION: PCASL technique provides reliable quantitative parameters for the precise mapping of age-related perfusion changes occurring in the normal brain.
Assuntos
Circulação Cerebrovascular , Angiografia por Ressonância Magnética , Adolescente , Adulto , Fatores Etários , Idoso , Criança , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Valores de Referência , Marcadores de Spin , Adulto JovemRESUMO
PURPOSE: The American College of Epidemiology (ACE) held its 2022 Annual Meeting, September 8-11, with a conference theme of 'Pandemic of Misinformation: Building Trust in Epidemiology'. The ACE Ethics Committee hosted a symposium session in recognition of the global spotlight placed on epidemiology and public health due to the COVID-19 crisis. The ACE Ethics Committee invited previous Chairs of the Ethics Committee and current President of the International Epidemiological Association to present at the symposium session. This paper aims to highlight the ethical challenges presented during the symposium session. METHODS: Three speakers with diverse backgrounds representing expertize from the fields of ethics, epidemiology, public health, clinical trials, pharmacoepidemiology, statistics, law, and public policy, covering perspectives from the U.S., Europe, and Southeast Asia were selected to present on the ethical challenges in epidemiology and public health applying a global theme. Dr. D. Weed presented on 'Causation, Epidemiology and Ethics'; Dr. C.M. Pandey presented on the 'Ethical Challenges in the Practice of Digital Epidemiology'; and Dr. J. Acquavella presented on 'Departures from Scientific Objectivity: A Cause of Eroding Trust in Epidemiology.' RESULTS: The collective goal to improve the public's health was a mutually shared theme across the three distinct areas. We highlight the common ethical guidance and principle-based approaches that have served epidemiology and public health in framing and critical analysis of novel challenges, including autonomy, beneficence, justice, scientific integrity, duties to the profession and community, and developing and maintaining public trust; however, gaps remain in how best to address health inequalities and the novel emergence and pervasiveness of misinformation and disinformation that have impacted the health of the global community. We introduce an ethical framework of translational bioethics that places considerations of the social determinants of health at the forefront. CONCLUSIONS: The COVID-19 pandemic required an expedited public health response and, at the same time, placed the profession of epidemiology and public health, its system, and structures, under the microscope like never before. This article illustrates that revisiting our foundations in research and practice and orienting contemporary challenges using an ethical lens can assist in identifying and furthering the health of populations globally.
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Bioética , COVID-19 , Humanos , Estados Unidos , Pandemias , Saúde Pública , Comissão de Ética , COVID-19/epidemiologiaRESUMO
PURPOSE: To modify the generalized tracer kinetic model (GTKM) by introducing an additional tissue uptake leakage compartment in extracellular extravascular space (LTKM). In addition, an implicit determination of voxel-wise local arterial input function (AIF) Cp (t) was performed to see whether these changes help in better discrimination between low- and high-grade glioma using dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI). MATERIALS AND METHODS: The modified model (LTKM) was explored and fitted to the concentration-time curve C(t) of each voxel, in which the local AIF Cp (t) could be estimated by a time invariant convolution approximation based on a separately measured global AIF Ca (t). A comparative study of tracer kinetic analysis was performed on 184 glioma patients using DCE-MRI data on 1.5T and 3T MRI systems. RESULTS: The LTKM analysis provided more accurate pharmacokinetic parameters as evidenced by their relative constancy with respect to the length of concentration-time curve used. In addition, LTKM with local AIF resulted in improved discrimination between low-grade and high-grade gliomas. CONCLUSION: LTKM with local AIF provides more accurate estimation of physiological parameters and improves discrimination between low-grade and high-grade gliomas as compared with GTKM.
Assuntos
Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/patologia , Gadolínio DTPA/farmacocinética , Glioma/metabolismo , Glioma/patologia , Imageamento por Ressonância Magnética/métodos , Adulto , Neoplasias Encefálicas/complicações , Artérias Cerebrais/metabolismo , Artérias Cerebrais/patologia , Simulação por Computador , Meios de Contraste , Espaço Extracelular/metabolismo , Feminino , Glioma/complicações , Humanos , Aumento da Imagem/métodos , Interpretação de Imagem Assistida por Computador/métodos , Masculino , Pessoa de Meia-Idade , Modelos Biológicos , Modelos Estatísticos , Gradação de Tumores , Permeabilidade , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Adulto JovemRESUMO
INTRODUCTION: Accurate grading of cerebral glioma using conventional structural imaging techniques remains challenging due to the relatively poor sensitivity and specificity of these methods. The purpose of this study was to evaluate the relative sensitivity and specificity of structural magnetic resonance imaging and MR measurements of perfusion, diffusion, and whole-brain spectroscopic parameters for glioma grading. METHODS: Fifty-six patients with radiologically suspected untreated glioma were studied with T1- and T2-weighted MR imaging, dynamic contrast-enhanced MR imaging, diffusion tensor imaging, and volumetric whole-brain MR spectroscopic imaging. Receiver-operating characteristic analysis was performed using the relative cerebral blood volume (rCBV), apparent diffusion coefficient, fractional anisotropy, and multiple spectroscopic parameters to determine optimum thresholds for tumor grading and to obtain the sensitivity, specificity, and positive and negative predictive values for identifying high-grade gliomas. Logistic regression was performed to analyze all the parameters together. RESULTS: The rCBV individually classified glioma as low and high grade with a sensitivity and specificity of 100 and 88 %, respectively, based on a threshold value of 3.34. On combining all parameters under consideration, the classification was achieved with 2 % error and sensitivity and specificity of 100 and 96 %, respectively. CONCLUSION: Individually, CBV measurement provides the greatest diagnostic performance for predicting glioma grade; however, the most accurate classification can be achieved by combining all of the imaging parameters.
Assuntos
Algoritmos , Neoplasias Encefálicas/patologia , Glioma/patologia , Interpretação de Imagem Assistida por Computador/métodos , Imageamento por Ressonância Magnética/métodos , Adolescente , Adulto , Idoso , Feminino , Humanos , Aumento da Imagem/métodos , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Adulto JovemRESUMO
INTRODUCTION: The study was performed to compare dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) with 3-dimensional (3D) pseudocontinuous arterial spin labeling (PCASL) MRI in gliomas with an aim to see whether arterial spin labeling (ASL)-derived cerebral blood flow (CBF) values can be used as an alternative to DCE-MRI for its grading. MATERIALS AND METHODS: Sixty-four patients with glioma (37 male; mean age, 43 years; 38 high grade and 26 low grade) underwent 3D-PCASL and DCE-MRI. The DCE indices (relative cerebral blood volume, rCBV; relative CBF, rCBF; permeability, k and kep; and leakage, ve) and ASL (absolute and rCBF) values were quantified from the tumors. Student independent t test was used to compare ASL and DCE-MRI indices. Pearson correlation was used to see correlation between DCE- and ASL-derived CBF values in tumor and normal parenchyma. RESULTS: On Student t test, neither ASL-derived absolute CBF (P = 0.78) nor rCBF (P = 0.12) values were found to be significantly different in 2 groups, whereas DCE indices except ve were significantly higher in high-grade gliomas. Arterial spin labeling-derived rCBF values weakly correlated with DCE-derived rCBF values, whereas these did not show correlation in normal grey (P = 0.12, r = 0.2) and white (P = 0.26, r = 0.14) matter regions. CONCLUSIONS: Three-dimensional pseudocontinuous arterial spin labeling does not appear to be a reliable technique in the current form and may not be a suitable replacement for DCE in grading of glioma.
Assuntos
Neoplasias Encefálicas/patologia , Glioma/patologia , Imageamento Tridimensional , Imageamento por Ressonância Magnética/métodos , Marcadores de Spin , Adulto , Circulação Cerebrovascular , Meios de Contraste , Feminino , Humanos , Masculino , Gradação de TumoresRESUMO
We present results of the studies relating to preparation of Langmuir-Blodgett (LB) monolayers of tri-n-octylphosphine oxide-capped cadmium selenide quantum dots (QCdSe) onto indium-tin oxide (ITO) coated glass substrate. The monolayer behavior has been studied at the air-water interface under various subphase conditions. This nanopatterned platform has been explored to fabricate an electrochemical DNA biosensor for detection of chronic myelogenous leukemia (CML) by covalently immobilizing the thiol-terminated oligonucleotide probe sequence via a displacement reaction. The results of electrochemical response studies reveal that this biosensor can detect target DNA in the range of 10(-6) to 10(-14) M within 120 s, has a shelf life of 2 months, and can be used about 8 times. Further, this nucleic acid sensor has been found to distinguish the CML-positive and the control negative clinical patient samples.
Assuntos
Técnicas Biossensoriais/métodos , Compostos de Cádmio/química , Leucemia Mielogênica Crônica BCR-ABL Positiva/diagnóstico , Nanotecnologia/métodos , Compostos de Selênio/química , Sequência de Bases , Técnicas Biossensoriais/instrumentação , Sondas de DNA/química , Sondas de DNA/genética , Eletroquímica , Eletrodos , Reutilização de Equipamento , Humanos , Nanotecnologia/instrumentação , Hibridização de Ácido Nucleico , Compostos Organofosforados/química , Pontos Quânticos , Propriedades de Superfície , Compostos de Estanho/químicaRESUMO
Chemokines regulates the trafficking of leukocytes to the site of inflammation hence may be implicated in cardiac events. Currently no consistent effects have been revealed their role in acute myocardial infarction (MI). The aim of current study was to investigate the impact of human chemokine receptor genetic variants, CCR5-Δ32 insertion/deletion, CCR5-59029-A/G, CX3CR1-V249I and CX3CR1-T280 M on acute MI. 230 acute MI and 300 controls were examined. Patients carrying CCR5-Δ32 genotype were at three times higher risk of developing MI odds ratio (OR, 3.24, CI 1.127-9.356, P = 0.04). Significant association was found with risk of acute MI in recipients who possessed homozygous 59029-A allele (OR 1.47, CI 1.03-2.09, P = 0.03). While CX3CR1-I249 and M280 were found to be protective in MI patients with OR 0.46, CI 0.32-0.66, P < 0.0001 and OR 0.36, CI 0.24-0.55, P < 0.0001, respectively. It might be possible that risk of acute MI is associated with genetic variation in chemokine receptors, i.e., CCR5 and CX3CR1.
Assuntos
Predisposição Genética para Doença/genética , Infarto do Miocárdio/epidemiologia , Infarto do Miocárdio/genética , Polimorfismo Genético/genética , Receptores CCR5/genética , Receptores de Quimiocinas/genética , Receptor 1 de Quimiocina CX3C , Análise Mutacional de DNA , Primers do DNA/genética , Frequência do Gene , Estudos de Associação Genética , Humanos , Índia/epidemiologia , Razão de Chances , Fatores de RiscoRESUMO
OBJECTIVES: This prospective, sequential study was done to understand changes in cerebral edema (CE) on magnetic resonance imaging and magnetic resonance spectroscopy, liver functions, and neurocognitive testing (NCT) in children with acute liver failure (ALF). METHODS: A total of 11 ALF and 8 healthy controls were evaluated with advanced magnetic resonance (MR) imaging, blood proinflammatory cytokines (PCs), thiamine levels, liver functions, and NCT. Reevaluation was done at 43.5â±â26.9 days (first follow-up, nâ=â8) and 157.3â±â52.3 days (second follow-up, nâ=â6) after discharge. RESULTS: At diagnosis, patients with ALF had vasogenic and cytotoxic CE, raised brain glutamine (23.2â±â3.4 vs. 15.3â±â2.7), and serum PCs (tumor necrosis factor [TNF]-α 40.1â±â8.9 vs. 7.2â±â2.7â pg/mL, interleukin [IL]-6 29.2â±â14.4 vs. 4.7â±â1.2 âpg/mL). The mammillary bodies (MBs) were smaller, and brain choline (1.9â±â0.36 vs. 2.6â±â0.6) and blood thiamine (55.2â±â6.7 vs. 81.8â±â10.2 ânmol/L) were lower than controls. At first follow-up, the brain glutamine and CE recovered. Brain choline and MBs volume showed improvement and thiamine levels normalized. Significant reduction in TNF-α and IL-6 was seen. The patients performed poorly on NCT, which normalized at second follow-up. Liver biochemistry and thiamine levels were normal and TNF-α and IL-6 showed further reduction at second follow-up. CONCLUSIONS: Patients with ALF have CE contributed by raised brain glutamine and PCs. MBs are small because of thiamine deficiency and show recovery in follow-up. CE and brain glutamine recover earlier than normalization of NCT and liver functions. Persistence of raised cytokines up to 6 months after insult suggests possible contribution from liver regeneration.
Assuntos
Edema Encefálico/etiologia , Transtornos Cognitivos/etiologia , Citocinas/sangue , Encefalopatia Hepática/etiologia , Falência Hepática Aguda/complicações , Fígado/patologia , Tiamina/sangue , Encéfalo/metabolismo , Encéfalo/patologia , Edema Encefálico/sangue , Edema Encefálico/metabolismo , Edema Encefálico/patologia , Estudos de Casos e Controles , Criança , Pré-Escolar , Colina/metabolismo , Cognição , Transtornos Cognitivos/sangue , Transtornos Cognitivos/metabolismo , Transtornos Cognitivos/patologia , Feminino , Seguimentos , Glutamina/metabolismo , Encefalopatia Hepática/sangue , Encefalopatia Hepática/metabolismo , Encefalopatia Hepática/patologia , Humanos , Mediadores da Inflamação/sangue , Interleucina-6/sangue , Falência Hepática Aguda/sangue , Falência Hepática Aguda/metabolismo , Falência Hepática Aguda/patologia , Imageamento por Ressonância Magnética , Espectroscopia de Ressonância Magnética , Masculino , Corpos Mamilares/patologia , Fator de Necrose Tumoral alfa/sangueRESUMO
INTRODUCTION: The purpose of the present study was to look for the possible predictors which might discriminate between high- and low-grade gliomas by pooling dynamic contrast-enhanced (DCE)-perfusion derived indices and immunohistochemical markers. METHODS: DCE-MRI was performed in 76 patients with different grades of gliomas. Perfusion indices, i.e., relative cerebral blood volume (rCBV), relative cerebral blood flow (rCBF), permeability (k (trans) and k (ep)), and leakage (v (e)) were quantified. MMP-9-, PRL-3-, HIF-1α-, and VEGF-expressing cells were quantified from the excised tumor tissues. Discriminant function analysis using these markers was used to identify discriminatory variables using a stepwise procedure. To look for correlations between immunohistochemical parameters and DCE metrics, Pearson's correlation coefficient was also used. RESULTS: A discriminant function for differentiating between high- and low-grade tumors was constructed using DCE-MRI-derived rCBV, k (ep), and v (e). The form of the functions estimated are "D (1) = 0.642 × rCBV + 0.591 × k (ep) - 1.501 × v (e) - 1.550" and "D (2) = 1.608 × rCBV + 3.033 × k (ep) + 5.508 × v (e) - 8.784" for low- and high-grade tumors, respectively. This function classified overall 92.1% of the cases correctly (89.1% high-grade tumors and 100% low-grade tumors). In addition, VEGF expression correlated with rCBV and rCBF, whereas MMP-9 expression correlated with k (ep). A significant positive correlation of HIF-1α with rCBV and VEGF expression was also found. CONCLUSION: DCE-MRI may be used to differentiate between high-grade and low-grade brain tumors non-invasively, which may be helpful in appropriate treatment planning and management of these patients. The correlation of its indices with immunohistochemical markers suggests that this imaging technique is useful in tissue characterization of gliomas.
Assuntos
Biomarcadores Tumorais/metabolismo , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/patologia , Glioma/metabolismo , Glioma/patologia , Imageamento por Ressonância Magnética/métodos , Adolescente , Adulto , Idoso , Volume Sanguíneo , Neoplasias Encefálicas/irrigação sanguínea , Circulação Cerebrovascular , Meios de Contraste , Análise Discriminante , Feminino , Glioma/irrigação sanguínea , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Técnicas Imunoenzimáticas , Masculino , Metaloproteinase 9 da Matriz/metabolismo , Pessoa de Meia-Idade , Proteínas de Neoplasias/metabolismo , Valor Preditivo dos Testes , Proteínas Tirosina Fosfatases/metabolismo , Fator A de Crescimento do Endotélio Vascular/metabolismoRESUMO
OBJECTIVE: To look for the association of tissue matrix metalloproteinase 9 (MMP-9) expression with dynamic contrast-enhanced magnetic resonance imaging and to see whether these can prognosticate patients with glioblastoma multiforme (GBM). METHODS: Forty-seven patients with GBM underwent dynamic contrast-enhanced magnetic resonance imaging to look for association of its indices with tissue MMP-9 expression using Pearson correlation. Kaplan-Meier survival analysis was performed to study the survival pattern for low-, medium-, and high-tissue MMP-9 expression and kep values. RESULTS: Among perfusion indices, kep, k, and ve significantly correlated with MMP-9 expression. Matrix metalloproteinase 9 expression was found to be best estimated by kep using a quadratic model. The 1-year survival in low-, medium-, and high-tissue MMP-9 and kep groups were 59%, 45%, and 7%, and 59%, 33%, and 15%, respectively. CONCLUSION: The association of kep and MMP-9 expression with survival suggests that kep may be used as imaging biomarker of GBM progression and its prognostication.
Assuntos
Biomarcadores Tumorais/metabolismo , Neoplasias Encefálicas/metabolismo , Glioblastoma/metabolismo , Metaloproteinase 9 da Matriz/metabolismo , Adulto , Meios de Contraste , Progressão da Doença , Feminino , Humanos , Técnicas Imunoenzimáticas , Imageamento por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Valor Preditivo dos Testes , Análise de SobrevidaRESUMO
OBJECTIVES: Glutathione S-transferase (GST) plays a key role in the detoxification of xenobiotic atherogens generated by smoking. We investigated whether functional GST gene polymorphism might be associated with acute myocardial infarction (AMI) and smoking. No such investigation has previously been conducted among North Indians. METHODS: 230 patients with AMI and 300 healthy controls of North Indian ethnicity were enrolled in the study. GSTM1/T1/P1 gene polymorphisms were examined using restriction fragment length polymorphism. RESULTS: When GST polymorphism was analyzed in patients with AMI, GSTM1 null genotype frequencies were 0.24 and 0.21 among cases with coronary artery disease and controls, respectively. The respective GSTT1 null genotype frequencies were 0.10 and 0.20 (p = 0.001). GSTP1 variant Val/Val allele frequencies were 0.02 and 0.07 with p = 0.03. After risk factor adjustment, only GSTP1Val/Val was found to be protective against disease. Considering the effect of GST (T1, M1, and P1) gene polymorphism on smoking, subjects were further divided into smokers and nonsmokers. However, GSTT1 null as well as GSTP Val/Val genotypes were protective only in nonsmokers (p = 0.01 and p = 0.04). CONCLUSIONS: A significant protective effect of GSTT1 null and GSTP1 Val genotype against disease was observed in patients with AMI although protection was limited to nonsmokers.
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Glutationa S-Transferase pi/genética , Glutationa Transferase/genética , Infarto do Miocárdio/genética , Fumar/efeitos adversos , Adulto , Estudos de Casos e Controles , Feminino , Frequência do Gene , Predisposição Genética para Doença , Genótipo , Humanos , Índia , Masculino , Pessoa de Meia-Idade , Polimorfismo de Fragmento de RestriçãoRESUMO
BACKGROUND & AIMS: Mild cognitive and psychomotor deficit has been reported in patients with extra-hepatic portal vein obstruction. This prospective study was done to ascertain the presence of minimal hepatic encephalopathy by neuropsychological testing and its correlation with diffusion tensor imaging derived metrics, T1 signal intensity, brain metabolites in (1)H magnetic resonance spectroscopy, blood ammonia and critical flicker frequency in patients with extra-hepatic portal vein obstruction. METHODS: Neuropsychological tests, critical flicker frequency, blood ammonia, diffusion tensor imaging, T1 signal intensity and (1)H magnetic resonance spectroscopy were determined in 22 extra-hepatic portal vein obstruction and 17 healthy children. Bonferroni multiple comparison post hoc analysis was done to compare controls with patient groups. RESULTS: Based on neuropsychological tests, 7/22 patients had minimal hepatic encephalopathy, and significantly increased Glx/Cr ratio, blood ammonia, mean diffusivity and globus pallidus T1 signal intensity with decreased critical flicker frequency in comparison to controls and in those without minimal hepatic encephalopathy. Cho/Cr, mI/Cr ratio and fractional anisotropy were unchanged in patient groups compared to controls. A significant inverse correlation of neuropsychological test with mean diffusivity, Glx/Cr ratio and blood ammonia and a positive correlation among mean diffusivity, blood ammonia and Glx/Cr ratio was seen. CONCLUSIONS: Extra-hepatic portal vein obstruction is a true hyperammonia model with porto-systemic shunting and normal liver functions that results in minimal hepatic encephalopathy in one-third of these children. Hyperammonia results in generalized low grade cerebral edema and cognitive decline as evidenced by increased Glx/Cr ratio, mean diffusivity values and abnormal neuropsychological tests.
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Constrição Patológica/complicações , Constrição Patológica/fisiopatologia , Encefalopatia Hepática/fisiopatologia , Encefalopatia Hepática/psicologia , Imageamento por Ressonância Magnética , Veia Porta/fisiopatologia , Psicometria , Amônia/sangue , Estudos de Casos e Controles , Criança , Cognição/fisiologia , Creatinina/sangue , Feminino , Fusão Flicker , Globo Pálido/patologia , Glutamatos/sangue , Glutamina/sangue , Encefalopatia Hepática/sangue , Humanos , Masculino , Testes Neuropsicológicos , Estimulação Luminosa , Fatores de Tempo , Visão Ocular/fisiologiaRESUMO
Diffusion tensor imaging (DTI) was performed in eight patients with brain abscess (BA). The aim of this study was to see the difference in the relationship between intercellular cell adhesion molecule-1 (ICAM-1) and lymphocyte function-associated antigen-1 (LFA-1) expression and DTI metrics measured in vivo in the wall and cavity of BA and its possible explanation vis-à-vis histology and immunohistochemistry. Neuroinflammatory molecules (NMs) were quantified from BA cavity aspirate of the patients and quantitative immunohistochemical analysis was performed for ICAM-1 and LFA-1 in the BA wall, showing maximal positive staining and correlated with DTI metrics. The fractional anisotropy (FA) significantly increased while mean diffusivity and spherical anisotropy significantly decreased in the BA wall compared to the BA cavity. In the BA wall, FA and linear anisotropy (CL) showed a significant positive correlation with ICAM-1 and LFA-1 expression whereas FA and planar anisotropy positively correlated with NMs quantified from aspirated pus respectively. Higher FA values in the BA wall compared to BA cavity, even when ICAM-1 and LFA-1 were expressed only in the macrophages and not in the collagen fibers, suggests that a combination of both concentric layers of collagen fibers as well as neutrophils and macrophages provide structural orientation and are responsible for increased FA. In the BA wall, increased CL was found compared to the cavity, indicating the presence of concentrically laid collagen fibers responsible for the diffusion of water molecules in the direction parallel to the collagen fibers. We conclude that in the BA, different mechanisms are operative for the changes in the DTI metrics in the wall and cavity; these conclusions are validated by histology and immunohistochemistry.
Assuntos
Abscesso Encefálico/patologia , Imagem de Tensor de Difusão/métodos , Adolescente , Adulto , Anisotropia , Abscesso Encefálico/metabolismo , Mapeamento Encefálico , Criança , Pré-Escolar , Feminino , Humanos , Imuno-Histoquímica , Lactente , Molécula 1 de Adesão Intercelular/metabolismo , Antígeno-1 Associado à Função Linfocitária/metabolismo , MasculinoRESUMO
BACKGROUND: Minimal hepatic encephalopathy (MHE) has recently been reported in patients with extrahepatic portal venous obstruction (EHPVO). AIMS: To evaluate brain changes by magnetic resonance studies in EHPVO patients. METHODS: Blood ammonia level, critical flicker frequency (CFF), brain metabolites on 1H-magnetic resonance (MR) spectroscopy and brain water content on diffusion tensor imaging and magnetization transfer ratio (MTR) were studied in 31 EHPVO patients with and without MHE, as determined by neuropsychological tests. CFF and magnetic resonance imaging studies were also performed in 23 controls. RESULTS: Fourteen patients (14/31, 45%) had MHE. Blood ammonia level was elevated in all, being significantly higher in the MHE than no MHE group. CFF was abnormal in 13% (4/31) with EHPVO and in 21% (3/14) with MHE. On 1H-MR spectroscopy, increased Glx/Cr, decreased mIns/Cr, and no change in Cho/Cr were noted in patients with MHE compared with controls. Significantly increased mean diffusivity (MD) and decreased (MTR) were observed in the MHE group, suggesting presence of interstitial cerebral oedema (ICE). MD correlated positively with blood ammonia level (r=0.65, P=0.003) and Glx (r=0.60, P=0.003). DISCUSSION: MHE was detected in 45% of patients with EHPVO while CFF was abnormal in only 13%. ICE was present in 7/10 brain regions examined, particularly in those with MHE. Hyperammonaemia elevated cerebral Glx levels correlated well with ICE. CONCLUSIONS: MHE was common in EHPVO; CFF could identify it only in a minority. ICE was present in EHPVO, particularly in those with MHE. It correlated with blood ammonia and Glx/Cr levels. Hyperammonaemia seems to contribute to ICE in EHPVO.
Assuntos
Edema Encefálico/diagnóstico , Encefalopatia Hepática/diagnóstico , Veia Porta/patologia , Adolescente , Adulto , Amônia/sangue , Encéfalo/metabolismo , Edema Encefálico/etiologia , Constrição Patológica/complicações , Constrição Patológica/patologia , Feminino , Fusão Flicker/fisiologia , Encefalopatia Hepática/etiologia , Humanos , Imageamento por Ressonância Magnética , MasculinoRESUMO
OBJECTIVE: To compare dynamic contrast-enhanced magnetic resonance imaging (DCE MRI) with diffusion tensor imaging (DTI) for predicting tumor infiltration in a conventional MRI normal-appearing internal capsule adjacent to the tumor in patients with glioblastoma multiforme. METHODS: Thirty patients with glioblastoma multiforme underwent a neurological examination for motor assessment, DCE MRI, and DTI. On fused DCE and DTI images, regions of interest were placed on the normal-appearing internal capsule and the corresponding region of the contralateral internal capsule. These patients were pooled into group 1 (improved after surgery, n = 9) and group 2 (did not improve after surgery, n = 21) on the basis of motor strength. The DTI and perfusion metrics were statistically analyzed to look for a predictor of motor functionality. RESULTS: Multivariate logistic regression analysis showed only cerebral blood volume to be the predictor of improvement in motor functionality after surgery (P = 0.043). CONCLUSIONS: We conclude that cerebral blood volume appears to be the predictor of motor functionality after surgery and may indirectly suggest tumor infiltration, whereas DTI helps to precisely localize the fiber tracts.
Assuntos
Neoplasias Encefálicas/patologia , Meios de Contraste , Glioblastoma/patologia , Aumento da Imagem/métodos , Imageamento por Ressonância Magnética/métodos , Tratos Piramidais/patologia , Adulto , Volume Sanguíneo , Encéfalo/irrigação sanguínea , Encéfalo/patologia , Mapeamento Encefálico/métodos , Circulação Cerebrovascular , Imagem de Difusão por Ressonância Magnética/métodos , Feminino , Humanos , Imageamento Tridimensional/métodos , Masculino , Pessoa de Meia-Idade , Atividade Motora , Valor Preditivo dos Testes , Estudos RetrospectivosRESUMO
One of the major challenges for scientists and engineers today is to develop technologies for the improvement of human health in both developed and developing countries. However, the need for cost-effective, high-performance diagnostic techniques is very crucial for providing accessible, affordable, and high-quality healthcare devices. In this context, microfluidic-based devices (MFDs) offer powerful platforms for automation and integration of complex tasks onto a single chip. The distinct advantage of MFDs lies in precise control of the sample quantities and flow rate of samples and reagents that enable quantification and detection of analytes with high resolution and sensitivity. With these excellent properties, microfluidics (MFs) have been used for various applications in healthcare, along with other biological and medical areas. This review focuses on the emerging demands of MFs in different fields such as biomedical diagnostics, environmental analysis, food and agriculture research, etc., in the last three or so years. It also aims to reveal new opportunities in these areas and future prospects of commercial MFDs.
Assuntos
Técnicas Biossensoriais/instrumentação , Técnicas Analíticas Microfluídicas/instrumentação , Desenho de Equipamento , Indústria Alimentícia , Humanos , Dispositivos Lab-On-A-Chip , Testes ImediatosRESUMO
INTRODUCTION: Despite reports of a high prevalence of chronic kidney disease (CKD) from the coastal Uddanam region of Andhra Pradesh, India, there are no accurate data on the distribution of kidney function abnormalities and CKD risk factors in this region. METHODS: A total of 2419 participants were recruited through multistage cluster random sampling from 67 villages. Serum creatinine and urine protein creatinine ratio were measured using validated methodologies. All abnormal estimated glomerular filtration rate (eGFR) and urine protein creatinine ratio values were reconfirmed after 3 months. A range of sociodemographic factors were evaluated for their association with CKD using Poisson regression. RESULTS: Of 2402 eligible subjects (mean ± SD age, 45.67 ± 13.29 years; 51% female), 506 (21.07%) had CKD (mean ± SD age, 51.79 ± 13.12 years; 41.3% female). A total of 246 (10.24%) had eGFR <60 ml/min/1.73 m2, whereas 371 (15.45%) had an elevated urine protein creatinine ratio (>0.15 g/g). The poststratified estimates, adjusted for age and sex distribution of the region for CKD prevalence, are 18.7% (range, 16.4%-21.0%) overall and 21.3% (range, 18.2%-24.4% ) and 16.2% (range, 13.7%-18.8%) in men and women, respectively. Older age, male sex, tobacco use, hypertension, and family history of CKD were independently associated with CKD. Compared with those with higher eGFR, those with eGFR <60 ml/min/1.73m2 were older, were more likely to be uneducated, manual laborers/farmers, or tobacco users, and were more likely to have hypertension, a family history of CKD, a diagnosis of heart disease, and a lower body mass index. Among those with low eGFR, there was no difference between those with urine protein creatinine ratio <0.15 or >0.15, except a lower frequency of males in the former. CONCLUSION: We confirmed the high prevalence of CKD in the adult population of Uddanam. The cause was not apparent in a majority. Subjects with a low eGFR with or without elevated proteinuria were phenotypically distinct from those with proteinuria and preserved eGFR. Our data suggest the need to apply a population-based approach to screening and prevention and studies to understand the causes of CKD in this region.
RESUMO
Transient early cerebral laminar organization resulting from normal developmental events has been revealed in human beings through histology and imaging studies. DTI studies have postulated that the fractional anisotropy (FA)-based differentiation of different laminar structures reflects both differing cellular density over the glial fibers and fiber alignment in respective regions. The aim of this study was to correlate FA values in these transient zones with histology. Brain DTI was performed on 50 freshly aborted human fetuses with gestational ages (GA) ranging from 12 to 42 weeks. Regions of interest were placed on the cortical plate, subplate, intermediate and germinal matrix (GMx) zones of the frontal lobe to quantify FA values. Glial fibrillary acidic protein (GFAP), neurofilament (NF) and neuron-specific enolase (NSE) immunohistochemical analyses were performed for the cortical plate, intermediate zone and GMx. In the cortical plate, a significant positive correlation was observed between FA values and percentage area of GFAP expression in fetuses Assuntos
Imagem de Tensor de Difusão/métodos
, Lobo Frontal/embriologia
, Feto Abortado
, Anisotropia
, Mapeamento Encefálico
, Contagem de Células
, Feminino
, Desenvolvimento Fetal
, Lobo Frontal/metabolismo
, Idade Gestacional
, Proteína Glial Fibrilar Ácida/metabolismo
, Humanos
, Processamento de Imagem Assistida por Computador
, Imuno-Histoquímica
, Imageamento por Ressonância Magnética
, Masculino
, Proteínas de Neurofilamentos/metabolismo
, Fosfopiruvato Hidratase/metabolismo
, Análise de Regressão
RESUMO
Region of interest based morphometric diffusion tensor imaging analysis, has been used extensively for the assessment of age-related changes in human brain, is limited to two dimensions and does not reflect the whole fiber bundle; however, diffusion tensor tractography (DTT) offers an overall view of individual fiber bundle in three-dimensional spaces. Quantitative DTT was performed on 51 healthy subjects of pediatric age range and young adults to compare age-related fractional anisotropy (FA) changes in corpus callosum, sensory and motor pathways, limbic tracts [cingulum (CNG) and fornix (Fx)], and superior and inferior longitudinal fascicules. In corpus callosum, inferior longitudinal fascicules, limbic tracts (CNG and Fx), sensory pathways, and motor pathways, an initial sharp increase in FA was observed up to the age of 2 y followed by a gradual increase up to 21 y. In superior longitudinal fascicules, sharp increase in FA was observed up to 3 y followed by a gradual increase. The FA value of the left CNG (p = 0.01, sign test) was observed to be significantly greater than that of the right CNG. We conclude that white matter fiber tracts mature with age and can be assessed by using DTT that may greatly improve our understanding of the human brain development.