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Dermatophagoides farina (D. farinae) and Dermatophagoides pteronyssinus (D. pteronyssinus) are the prevalent kinds of house dust mites (HDMs). HDMs are common inhalant allergens that cause a range of allergic diseases, such as rhinitis, atopic dermatitis, and asthma. The epidemiology of these diseases is associated with exposure to mites. Therefore, in the present study, a method named multiplex loop-mediated isothermal amplification (LAMP) was developed to detect environmental dust mites. The multiplex LAMP assay allows amplification within a single tube and has an ITS plasmid detection limit as low as 40 fg/µL for both single dust mites and mixed dust mites (D. pteronyssinus and D. farinae), which is up to ten times more sensitive than classical PCR techniques. Furthermore, the multiplex LAMP method was applied to samples of single dust mites and clinical dust to confirm its validity. The multiplex LAMP assay exhibited higher sensitivity, simpler instrumentation, and visualization of test results, indicating that this method could be used as an alternative to traditional techniques for the detection of HDMs.
Assuntos
Dermatophagoides farinae , Dermatophagoides pteronyssinus , Técnicas de Amplificação de Ácido Nucleico , Animais , Dermatophagoides pteronyssinus/genética , Dermatophagoides farinae/genética , Técnicas de Amplificação de Ácido Nucleico/métodos , Técnicas de Diagnóstico Molecular/métodos , Sensibilidade e EspecificidadeRESUMO
Nitrous oxide (N2O) generation during composting not only leads to losses of nitrogen (N) but also reduces the agronomic values and environmental benefits of composting. This study aimed to investigate the effect of the C/N ratio on N2O emissions and its underlying mechanisms at the genetic level during the composting of vegetable waste. The experiment was set up with three treatments, including low C/N treatment (LT, C/N = 18), middle C/N treatment (MT, C/N = 30), and high C/N treatment (HT, C/N = 50). The results showed that N2O emission was mainly concentrated in the cooling and maturation periods, and the cumulative N2O emissions decreased as the C/N ratio increased. Specifically, the cumulative N2O emission was 57,401 mg in LT, significantly higher than 2155 mg in MT and 1353 mg in HT. Lowering the C/N ratio led to increasing TN, NH4+-N, and NO3--N contents throughout the composting process. All detected nitrification-related gene abundances in LT continued to increase during composting, significantly surpassing those in MT during the cooling period. By contrast, in HT, there was a slight increase in the abundance of detected nitrification-related genes but a significant decrease in the abundance of narG, napA, and norB genes in the thermophilic and cooling periods. The structural equation model revealed that hao and nosZ genes were vital in N2O emissions. In conclusion, increasing the C/N ratio effectively contributed to N2O reduction during vegetable waste composting.
Assuntos
Carbono , Compostagem , Nitrogênio , Óxido Nitroso , Verduras , Óxido Nitroso/análise , Solo/químicaRESUMO
Introduction: The brown planthopper (BPH) poses a significant threat to rice production in Asia. The use of resistant rice varieties has been effective in managing this pest. However, the adaptability of BPH to resistant rice varieties has led to the emergence of virulent populations, such as biotype Y BPH. YHY15 rice, which carries the BPH resistance gene Bph15, exhibits notable resistance to biotype 1 BPH but is susceptible to biotype Y BPH. Limited information exists regarding how resistant rice plants defend against BPH populations with varying levels of virulence. Methods: In this study, we integrated miRNA and mRNA expression profiling analyses to study the differential responses of YHY15 rice to both avirulent (biotype 1) and virulent (biotype Y) BPH. Results: YHY15 rice demonstrated a rapid response to biotype Y BPH infestation, with significant transcriptional changes occurring within 6 hours. The biotype Y-responsive genes were notably enriched in photosynthetic processes. Accordingly, biotype Y BPH infestation induced more intense transcriptional responses, affecting miRNA expression, defenserelated metabolic pathways, phytohormone signaling, and multiple transcription factors. Additionally, callose deposition was enhanced in biotype Y BPH-infested rice seedlings. Discussion: These findings provide comprehensive insights into the defense mechanisms of resistant rice plants against virulent BPH, and may potentially guide the development of insect-resistant rice varieties.
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Interactions between rice plants (Oryza sativa L.) and brown planthoppers (Nilaparvata lugens Stål, BPHs) are used as a model system to study the molecular mechanisms underlying plant-insect interactions. Small RNAs (sRNAs) regulate growth, development, immunity, and environmental responses in eukaryotic organisms, including plants and insects. Recent research suggests that sRNAs play significant roles in rice-BPH interactions by mediating post-transcriptional gene silencing. The focus of this review is to explore the roles of sRNAs in rice-BPH interactions and to highlight recent research progress in unraveling the mechanism of cross-kingdom RNA interference (ckRNAi) between host plants and insects and the application of ckRNAi in pest management of crops including rice. The research summarized here will aid in the development of safe and effective BPH control strategies.
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In recent years, improving the surface properties of large-scale insulation by plasma modification has attracted extensive attention with the development of power systems and high-tech industries. However, routine evaluations of the modification effect and uniformity require complicated tests after the plasma is powered off, which waste a lot of time and cannot regulate the modification effect online. In this study, a novel fluorescence-assisted dielectric barrier discharge (DBD) for fabricating a functional film is developed, and a rapid evaluation method of the modification effect and uniformity is proposed based on fluorescence coloring and image processing technologies. The results show that the addition of an organic fluorescent agent in the DBD with hexamethyldisiloxane (HMDSO) has no negative effect on the plasma discharge and modification effect, and the fluorescence-assisted DBD successfully fabricates the functional films with typical chromogenic groups (N-H and SâO) that exhibit typical fluorescence under an UV lamp. According to image processing and parameter extraction, the plasma-assisted fluorescent film is converted into a two-dimensional (2D) color map with nine color levels, and three characteristic parameters are proposed to evaluate the modification effect rapidly and directly. It shows that the warmer the color of the treated sample, the better the hydrophobicity and electrical insulating properties, where the red region represents the optimally modified surface, while the blue region represents the worst one. The area, shape, and integrity of the plasma modification are clarified quantificationally, which provides the possibility of further online evaluation of the modification effect and uniformity by the plasma treatment.
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Mineralization coupled with neutralization is a dual-function technology for disposing acidic iron-rich waters, which can recover the valuable iron in the form of secondary mineral and concurrently purify the wastewater. In this study, a modified technology for treating high Fe wastewater (sulfur acid spent pickling liquor, 62â¯g Fe/L) was proposed based on the specific investigation of the mineralization behaviors in Fe concentration range of 20-70â¯g/L. Results showed that high SO42-/Fe2+ molar ratio (> 2.0) tended to trigger gelation phenomena at Fe concentrations above 30â¯g/L. Fe specie distribution suggested that the insufficient polymerization among Fe-OH complexes might be responsible for the gelation phenomena, since the strong Fe-SO4 coordination almost completely suppressed the Fex(OH)y(3x-y)+ form (a general terms of Fe3+ hydrolysates and their polymers). Modified mineralization strategies were proposed, including pretreatment with dilution or BaCl2/CaCl2 precipitation, of which CaCl2 pretreatment was a versatile and low-cost method. Following CaCl2 pretreatment, chemical mineralization converted above 90% of iron into secondary mineral, which therefore drastically reduced the alkali consumption (from 164.2â¯g/L to 1.4â¯g/L) and sludge yield (from 328.1â¯g/L to 2.4â¯g/L) in subsequent neutralization treatment. The resultant mineral was identified as schwertmannite, and exhibited efficient adsorption capacity toward arsenite (364.2â¯mg/g). The modified chemical mineralization-alkaline neutralization is a cost-effective technology for the treatment of the acidic iron-rich waters. In practical applications, several regulating strategies should be further explored to improve the mineral purity, and the mineralization conditions must be optimized according to the Fe and SO42- concentrations in wastewater.
Assuntos
Águas Residuárias , Poluentes Químicos da Água , Ácidos , Álcalis , Cloreto de Cálcio , Ferro/química , Minerais , Enxofre , Poluentes Químicos da Água/análiseRESUMO
Copper as an essential trace element is hypothesized to be involved in stroke risk. However, the evidence for associations between copper and stroke risk factors such as lipid levels has been mixed. This study aimed to examine the relationships between serum copper and lipid levels among 3425 participants aged 20 years and older from the 2011-2016 National Health and Nutrition Examination Survey (NHANES). Data on administered questionnaires, serum copper concentrations, and lipid levels (total cholesterol, HDL cholesterol, triglycerides, and LDL cholesterol) were used. Associations between serum copper and lipid levels were evaluated using both multivariable linear regression and logistic regression models. In the linear regression models, total cholesterol and LDL cholesterol levels increased with increasing copper concentrations among women. Each 1 unit (µg/dL) increase in serum copper concentrations was associated with roughly 0.11 mg/dL higher total cholesterol (95%CI: 0.04-0.18; P < 0.05) and roughly 0.09 mg/dL higher LDL cholesterol (95%CI: 0.01-0.17; P < 0.05) among women, respectively. Serum copper was positively associated with high LDL cholesterol among women, and the multivariate-adjusted OR (95% CI) for the third quartile of serum copper concentrations was 4.25 (1.15-15.77) compared with the lowest quartile. Moreover, compared with the lowest quartile, the multivariate-adjusted OR (95% CI) for the third quartile of serum copper concentrations was 1.82 (1.16-2.85) for risk of having high total cholesterol among men. No significant association between serum copper and triglycerides levels was observed. These findings suggest that copper may impact stroke health via effects on lipid levels but need to be confirmed with prospective data.
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Cobre , Acidente Vascular Cerebral , Adulto , HDL-Colesterol , Feminino , Humanos , Masculino , Inquéritos Nutricionais , Estudos Prospectivos , Fatores de Risco , Acidente Vascular Cerebral/epidemiologia , TriglicerídeosRESUMO
The available findings on the association between iron status and risk of stroke remain controversial. We used multivariable logistic regression and restricted cubic spline models to explore the association between iron exposures and risk of stroke in the US National Health and Nutrition Examination Survey (NHANES 2007-2016, n = 24,627). A total of 941 (3.82%) stroke cases were identified in this study. In women, the ORs with 95% CIs of prevalence of stroke were 0.92 (0.65-1.28), 0.66 (0.44-0.98) and 0.72 (0.49-1.08) across quartiles 2-4 compared with quartile 1 of iron intake, respectively. An inverse and L-shaped association between iron intake and risk of stroke in women was observed, and the curve plateaued at 20 mg/day. However, neither serum iron concentrations nor iron intake were significantly associated with riskof stroke in men. Our study found that iron intake was inversely associated with risk of stroke in a sex-dependent fashion.
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Ferro , Acidente Vascular Cerebral , Adulto , Estudos Transversais , Dieta , Feminino , Humanos , Masculino , Inquéritos Nutricionais , Acidente Vascular Cerebral/epidemiologia , Estados Unidos/epidemiologiaRESUMO
The complete mitochondrial genome was sequenced from the marine teleost fish Inimicus japonicus. The genome sequence is 16,830 bp in size and has a base composition of A (29.25%), T (29.01%), C (20.7%), and G (21.03%). Moreover, 13 protein-coding genes (PCGs) encoded 3210 amino acids in total. The phylogenetic analysis showed that I. japonicus belongs to Synancejidae family. The complete mitochondrial genome sequences provided here would be useful for further understanding the evolution and conservation genetics of I. japonicus.
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Forming a large-scale droplet array plays an important role for microfluidic droplet-based high-throughput screening and analysis. Herein, we describe a simple and rapid method to form a large-scale two-dimension (2D) droplet array by using a microcage array chip. Differing from the previous droplet array formation methods, microcages formed by being surrounded by multiple micropillars could rapidly spread the oil phase through the gaps between the micropillars and trap droplets with fast speed and convenient operation. We formed a large-scale 2D monolayer droplet array containing approximately 1â¯000â¯000 droplets on a 5.5 cm × 5.5 cm microcage array chip within 90 s. The droplets in the droplet array could be further incubated for performing biochemical reactions and detected by a fluorescence microscope in real time. Due to the exact trapping and positioning functions of the microcages to the droplets, single targeted fluorescent droplets in the array could be individually picked out and transferred to culture medium by a microfluidic droplet-handling robot with a success rate of 100% and a picking operation time of 2.0 s for one droplet under the optimized conditions. This system was validated in the screening of the bacterium expressing the esterase AFEST from a mixture of AFEST-expressing and phosphotriesterase-expressing E. coli cells, achieving a success rate of 100% for single-droplet picking while maintaining the bacterial cell viability. The present system has the potential to be applied in high-throughput screening and analysis, such as single cell analysis, directed evolution, and drug screening.
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Esterases/análise , Ensaios de Triagem em Larga Escala , Técnicas Analíticas Microfluídicas , Sobrevivência Celular , Avaliação Pré-Clínica de Medicamentos , Escherichia coli/citologia , Escherichia coli/metabolismo , Esterases/metabolismo , Tamanho da Partícula , Análise de Célula Única , Propriedades de SuperfícieRESUMO
Previous studies have shown that exposure of Arabidopsis leaves to high light (HL) causes a systemic acquired acclimation (SAA) response in the vasculature. It has been postulated that C4-like photosynthesis in the leaf veins triggers this response via the Mehler reaction. To investigate this proposed connection and extend SAA to other plants, we examined the redox state of NADPH, ascorbate (ASA), and glutathione (GSH) pools; levels and histochemical localization of O2- and H2O2 signals; and activities of antioxidant enzymes in the midvein and leaf lamina of rice, when they were subjected to HL and low light. The results showed that (1) high NADPH/NADP(+) was generated by C4-like photosynthesis under HL in the midvein and (2) SAA was colocally induced by HL, as indicated by the combined signaling network, including the decrease in redox status of ASA and GSH pools, accumulation of H2O2 and O2- signals, and high superoxide dismutase (SOD) and ascorbate peroxidase (APX) activities. The high correlations between these occurrences suggest that the enhanced NADPH/NADP(+) in HL-treated midveins might alter redox status of ASA and GSH pools and trigger H2O2 and O2- signals during SAA via the Mehler reaction. These changes in turn upregulate SOD and APX activities in the midvein. In conclusion, SAA may be a common regulatory mechanism for the adaptation of angiosperms to HL. Manipulation of NADPH/NADP(+) levels by C4-like photosynthesis promotes SAA under HL stress in the midvein.
Assuntos
NADP/metabolismo , Oryza/metabolismo , Folhas de Planta/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Aclimatação , FotossínteseRESUMO
Despite the increasing occurrence of ultraviolet-B (UV-B) radiation, its molecular mechanism is poorly documented in higher plants compared to other environmental stress. In present study, the influence of supplemental UV-B radiation on photosynthetic performance and antioxidant enzymes in rice (Oryza sativa L.) was investigated. Supplemental UV-B radiation reduced net photosynthetic rate in rice flag leaves during senescence stage. By means of the JIP-test, it was found that the potential of processing light energy through the photosynthetic machinery was slightly inhibited by the increased thermal dissipation. Furthermore, 18 thylakoid membrane protein spots were differentially expressed (5-fold or greater variation compared to the control) in supplemental UV-B-treated rice. These identified proteins were involved in various cellular responses and metabolic processes including photosynthesis, stress defense, Calvin cycle, and others of unknown functions. Taken together, these results suggested that physiological changes that resulted from supplemental UV-B radiation were linked to the light reaction, carbon metabolism, and antioxidant enzymes in rice leaves during senescence stage.
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Antioxidantes/metabolismo , Oryza/enzimologia , Oryza/efeitos da radiação , Fotossíntese/efeitos da radiação , Proteínas de Plantas/biossíntese , Raios Ultravioleta , Clorofila/biossíntese , Oryza/crescimento & desenvolvimento , Oryza/metabolismo , Fotossíntese/fisiologia , Folhas de Planta/enzimologia , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/metabolismo , Folhas de Planta/efeitos da radiação , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Tilacoides/metabolismoRESUMO
In this work, a promising electrochemical detector has been fabricated by immersing a glass carbon electrode (GCE) in aniline containing novel ionic liquid and scanning between -1.0 and 1.0 V for 40 cycles, and was used in ion chromatography (IC) system. The morphology of the modified electrode surface was characterized by scanning electron microscope (SEM). The polyaniline (PANI) film showed excellent electrocatalytic activity than bare GCE and provided enhanced selectivity and stability for the detection of ascorbic acid (AA). Separated by IC with phosphate buffer solution (pH = 5.2) as eluent, AA could be determined by the PANI/GCE successfully at the working potential of 0.3 V. The retention time of AA was approximately 5.75 min, and the peak shape of AA was satisfactory. The calibration curve of AA was linear (r > 0.99), in the range between 0.05 mg/L and 1000 mg/L and the detection limit was 23.41 µg/L (S/N = 3). The proposed method was successfully applied in the detection of AA in four beverage samples. The recoveries of AA in these samples were from 92.32% to 110.57%.
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Compostos de Anilina/química , Cromatografia por Troca Iônica/instrumentação , Líquidos Iônicos/química , Ácido Ascórbico/análise , Bebidas , Cromatografia por Troca Iônica/métodos , Eletrodos , OxirreduçãoRESUMO
A new column-switching method has been proposed for the determination of 14 organic explosives (1,3,5,7-tetranitro-N-methylaniline, 1,3,5-trinitro-1,3,5-triazacyclohexane, 1,3,5-trinitrobenzene, 1,3-dinitrobenzene, nitrobenzene, 2,4,6-N-tetranitro-N-methylaniline, Trinitrotoluene, 4-amino-2,6-dinitrotoluene, 2-amino-4,6-dinitrotoluene, 2,6-dinitrotoluene, 2,4-dinitrotoluene, 2-nitrotoluene, 4-nitrotoluene, and 3-nitrotoluene) and/or five inorganic cations (Na(+), NH(4)(+), K(+), Mg(2+), and Ca(2+)) using liquid chromatography linked to ion chromatography by a switching valve. The mobile phase was methanol-water (40/60, v/v) for a C18 reversed-phase column and 3 mM of methanesulfonic acid (pH 2.5) for a cation-exchange column, respectively. Under the optimal conditions, the 14 organic explosives and the five inorganic cations were separated and detected simultaneously within 45 min. The limits of detection (S/N = 3) of the 14 organic explosives and the five inorganic cations were in the range of 0.0048-0.0333 mg/L and 0.0116-0.1851 mg/L, respectively. The linear correlation coefficients were 0.9971-0.9999, and the relative standard deviation of the retention time and the peak area were 0.02-0.31% and 0.51-3.64%, respectively. The method was successfully applied to the determination of organic explosives and inorganic cations in dust samples.
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Compostos de Anilina/análise , Derivados de Benzeno/análise , Cromatografia por Troca Iônica/métodos , Substâncias Explosivas/análise , Cátions/análise , Cromatografia por Troca Iônica/instrumentação , Poeira , Desenho de Equipamento , Mesilatos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Fatores de Tempo , Triazinas/análiseRESUMO
Ion-pair reagent was used as mobile phase for the simultaneous separation of chlormequat chloride and mepiquat chloride in plants. The rapid separation was performed on a Dionex IonPac NG1 guard column and a Dionex IonPac NS1 analytical column using 1.0 mL/min of the eluent mixture of 1.00 mmol/L nonafluoropentanoic acid (as ion-pair reagent) and 7% acetonitrile, and the detection was achieved by a suppressed conductivity detector. The method provided good resolution of the analyte peaks without any interference. The detection limits of chlormequat chloride and mepiquat chloride were 0.154 6 mg/L and 0.171 4 mg/L, respectively. The linear calibration curves were obtained in the range of 1 - 100 mg/L. The mean recoveries in the ranges of 96.06% - 104.6% for chlormequat chloride and 98.53% - 103.7% for mepiquat chloride were obtained in real samples. The method requires only simple sample preparation and the technique is suitable for routine quality control analysis.
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Clormequat/análise , Cromatografia por Troca Iônica/métodos , Piperidinas/análise , Plantas/química , Resíduos de Drogas/análise , Reguladores de Crescimento de Plantas/análiseRESUMO
The pharmacokinetic analysis of dynamic-contrast-enhanced (DCE) MRI data yields K(trans) and k(ep), two parameters independently measuring the capillary wall contrast reagent transfer rate. The almost universally used standard model (SM) embeds the implicit assumption that equilibrium transcytolemmal water exchange is effectively infinitely fast. In analyses of routine DCE-MRI data from 22 patients with suspicious breast lesions initially ruled positive by institutional screening protocols, the SM K(trans) values for benign and malignant lesions exhibit considerable overlap. A form of the shutter-speed model (SSM), which allows for finite exchange kinetics, agrees with the SM K(trans) value for each of the 15 benign lesions. However, it reveals that the SM underestimates K(trans) for each of the seven malignant tumors in this population. The fact that this phenomenon is unique to malignant tumors allows their complete discrimination from the benign lesions, as validated by comparison with gold-standard pathology analyses of subsequent biopsy tissue samples. Likewise, the SM overestimates k(ep), particularly for the benign tumors. Thus, incorporation of the SSM into the screening protocols would have precluded all 68% of the biopsy/pathology procedures that yielded benign findings. The SM/SSM difference is well understood from molecular first principles.
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Neoplasias da Mama/irrigação sanguínea , Imageamento por Ressonância Magnética/instrumentação , Neoplasias da Mama/patologia , Meios de Contraste/farmacocinética , Feminino , HumanosRESUMO
The passage of a vascular-injected paramagnetic contrast reagent (CR) bolus through a region-of-interest affects tissue (1)H(2)O relaxation and thus MR image intensity. For longitudinal relaxation [R(1) identical with (T(1))(-1)], the CR must have transient molecular interactions with water. Because the CR and water molecules are never uniformly distributed in the histological-scale tissue compartments, the kinetics of equilibrium water compartmental interchange are competitive. In particular, the condition of the equilibrium trans cytolemmal water exchange NMR system sorties through different domains as the interstitial CR concentration, [CR(o)], waxes and wanes. Before CR, the system is in the fast-exchange-limit (FXL). Very soon after CR(o) arrival, it enters the fast-exchange-regime (FXR). Near maximal [CR(o)], the system could enter even the slow-exchange-regime (SXR). These conditions are defined herein, and a comprehensive description of how they affect quantitative pharmacokinetic analyses is presented. Data are analyzed from a population of 22 patients initially screened suspicious for breast cancer. After participating in our study, the subjects underwent biopsy/pathology procedures and only 7 (32%) were found to have malignancies. The transient departure from FXL to FXR (and apparently not SXR) is significant in only the malignant tumors, presumably because of angiogenic capillary leakiness. Thus, if accepted, this analysis would have prevented the 68% of the biopsies that proved benign.
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Neoplasias da Mama/diagnóstico , Meios de Contraste , Imageamento por Ressonância Magnética/métodos , Neoplasias da Mama/patologia , Carcinoma Intraductal não Infiltrante/diagnóstico , Meios de Contraste/farmacocinética , Feminino , Humanos , Espectroscopia de Ressonância MagnéticaRESUMO
Although neoadjuvant chemoradiation eradicates esophageal adenocarcinoma in a substantial proportion of patients, conventional imaging techniques cannot accurately detect this response. Dynamic contrast-enhanced magnetic resonance imaging is an emerging approach that may be well suited to fill this role. This pilot study evaluates the ability of this method to discriminate adenocarcinoma from normal esophageal tissue. Patients with esophageal adenocarcinoma and control subjects underwent scanning. Patients treated with neoadjuvant therapy underwent pre- and postchemoradiation scans. Parameters were extracted for each pixel were Ktrans (equilibrium rate for transfer of contrast reagent across the vascular wall), ve (volume fraction of interstitial space), and taui (mean intracellular water lifetime). Five esophageal adenocarcinoma patients and two tumor-free control subjects underwent scanning. The mean Ktrans value was 5.7 times greater in esophageal adenocarcinoma, and taui is 2.0 times smaller, than in the control subjects. Ktrans decreased by 11.4-fold after chemoradiation. Parametric maps qualitatively demonstrate a difference in Ktrans. DCE MRI of the esophagus is feasible. Ktrans, a parameter that has demonstrated discriminative ability in other malignancies, also shows promise in differentiating esophageal adenocarcinoma from benign tissue. The determination of Ktrans represents an in vivo assay for endothelial permeability and thus may serve as a quantitative measure of response to induction chemoradiation.
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Adenocarcinoma/diagnóstico , Meios de Contraste/administração & dosagem , Neoplasias Esofágicas/diagnóstico , Compostos Heterocíclicos , Imageamento por Ressonância Magnética/métodos , Compostos Organometálicos , Diagnóstico Diferencial , Gadolínio , Compostos Heterocíclicos/administração & dosagem , Humanos , Injeções Intravenosas , Masculino , Compostos Organometálicos/administração & dosagem , Projetos Piloto , Reprodutibilidade dos TestesRESUMO
Despite numerous studies showing neurotrophic and neuroprotective effects of estrogen in animal models, the long-term effects of estrogen use on brain morphology in older women are not known. Thus, we compared ventricular, cerebrospinal fluid, white matter, and grey matter volumes estimated from magnetic resonance images of postmenopausal women with more than 20 years exposure to unopposed estrogen, women who were not on estrogen, and young healthy women. Estrogen users had significantly smaller ventricles and greater white matter volumes than non-users, but hormone exposure did not affect grey matter volumes. Young healthy women had significantly smaller ventricles, less cerebrospinal fluid and more grey matter than both groups of older women. However, they had comparable white matter volumes to older women on estrogen. These findings suggest that long-term estrogen protects against white matter loss in aging. This adds to findings from other studies suggesting estrogen is neuroprotective of the hippocampus and other regions in older women.