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1.
J Colloid Interface Sci ; 673: 537-549, 2024 Jun 14.
Artículo en Inglés | MEDLINE | ID: mdl-38885539

RESUMEN

Electrocatalytic nitrogen reduction reaction (ENRR) is a promising and efficient method for ammonia production. However, ENRR is restricted by the adsorption and activation of N2. Herein, an efficient nitrogen reduction reaction (NRR) electrocatalyst loaded with zero valent iron (ZVI) particles onto porous nitrogen-doped carbon (NC) hollow spheres is reported. The optimal Fe@10N3C-950 exhibits excellent performance with high ammonia (NH3) yield (152.28 µg h-1 mgcat-1) and Faradaic efficiency (FE, 54.55 %) at - 0.3 V (versus reversible hydrogen electrode, vs. RHE). Bader charge shows that the adsorbed N2 acquires more electrons from Fe sites with body-centered cubic (BCC) structure to better activate N2. Moreover, i-t experiments are performed before electrocatalytic NH3 production to effectively eliminate the effect of oxidation on ZVI and thus, maintain high ENRR activity for Fe@10N3C-950. Theoretical calculations indicate that nitrogen doping not only reduces the Gibbs free energy of rate determining step (RDS), but the BCC-structured Fe can also decrease the energy barriers of N2 activation and RDS.

2.
J Biochem Mol Toxicol ; 38(1): e23550, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37815028

RESUMEN

Uric acid, an oxidation end-product of purine metabolism, is reportedly to be a risk factor for kidney injury. However, its underlying mechanism is still a mystery. This study aimed to reveal the detailed roles of uric acid in inducing kidney injury and the possible mechanisms. Injection of rats with uric acid significantly increased tubular injury score, and levels of blood urea nitrogen, serum creatinine, and urine kidney injury molecule-1. Uric acid increased the expression of collagen I, alpha-smooth muscle actin, tumor necrosis factor (TNF)-α, interleukin (IL)-1ß, and IL-6. Kyoto Encyclopedia of Genes and Genomes analysis result showed the IL-17 signaling pathway as the most significantly enriched pathway involved in hyperuricemia-related kidney injury. Long-term injection of uric acid induced significant production of IL-17 and recruitment of Th17 cells. Treating rats with the anti-IL-17 mAb attenuated uric acid-induced kidney injury, accompanied by the inactivation of nuclear factor-κB (NF-κB). In conclusion, uric acid was confirmed to be a risk factor for kidney injury via inducing IL-17 expression. Neutralization of IL-17 using the specific mAb relieved uric acid-induced kidney injury via inhibition of NF-κB signaling.


Asunto(s)
FN-kappa B , Ácido Úrico , Ratas , Animales , Ácido Úrico/metabolismo , FN-kappa B/metabolismo , Interleucina-17 , Riñón/metabolismo , Transducción de Señal , Factor de Necrosis Tumoral alfa/metabolismo
3.
Biodegradation ; 34(1): 73-81, 2023 02.
Artículo en Inglés | MEDLINE | ID: mdl-36401058

RESUMEN

Bisphenol A (BPA) has been widely used in the manufacture of polymeric materials. BPA is regarded as an endocrine disrupting chemical, posing a great threat to the public health. In this study, a bacterial strain LM-1, capable of utilizing BPA as the sole carbon and energy source under aerobic conditions, was originally isolated from an activated sludge sample. The isolate was identified as Pseudomonas sp. based on 16S rRNA gene sequence analysis. Strain LM-1 was able to completely degrade 25-100 mg/L BPA within 14-24 h, and it also exhibited high capacity for BPA degradation at a range of pH (6.0-8.0). (NH4)2SO4 and NH4NO3 were the suitable nitrogen sources for its growth and BPA biodegradation, and the BPA degradation could be accelerated when exogenous carbon sources were introduced as the co-substrates. Metal ions such as Zn2+, Cu2+, and Ni2+ could considerably suppress the growth of strain LM-1 and BPA degradation. According to the analysis of liquid chromatography coupled to Q-Exactive high resolution mass spectrometry, hydroquinone, p-hydroxybenzaldehyde, and p-hydroxybenzoate were the predominate metabolites in the BPA biodegradation and the degradation pathways were proposed. This study is important for assessment of the fate of BPA in engineered and natural systems and possibly for designing bioremediation strategies.


Asunto(s)
Fenoles , Pseudomonas , Pseudomonas/metabolismo , ARN Ribosómico 16S/genética , Fenoles/metabolismo , Compuestos de Bencidrilo/metabolismo , Biodegradación Ambiental , Carbono
4.
Front Public Health ; 10: 937844, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36530737

RESUMEN

Background: The COVID-19 pandemic has disrupted the diagnosis, treatment, and care for tuberculosis (TB). Delays in seeking TB care may result in increased community transmission and unfavorable treatment outcomes. We sought to understand the influence of the COVID-19 pandemic on the proportion of patients with TB who delayed seeking the diagnosis and care for TB and explore the reasons for their postponement. Methods: We surveyed a representative sample of outpatients treated for pulmonary TB from June to November 2020 using an anonymous standardized questionnaire. Multivariable logistic regression was used to calculate adjusted odds ratios (aOR) and 95% confidence intervals (CIs) of factors associated with the postponement of TB care. We used routinely collected surveillance data to assess trends of TB reports before and after the emergence of COVID-19 (2017-2019 vs. 2020-2022) in Tianjin, China. Results: Among 358 participants who were diagnosed with pulmonary TB during the COVID-19 response, 61 (17%) postponed seeking TB diagnosis due to COVID-19, with 39 (64%) citing fear as the primary reason. Female sex (aOR:2.0; 95% CI: 1.1-3.7), previous antituberculosis treatment (aOR:3.2; 95%CI: 1.4-7.6), and TB diagnosis during the first-level response (aOR = 3.2, 1.7-6.2) were associated with the postponement. Among all 518 participants receiving antituberculosis treatment, 57 (11%) had postponed their regular healthcare visits due to COVID-19, 175 (34%) received no treatment supervision, and 32 (6%) experienced treatment interruption. Compared to 2017-2019, reported pulmonary TB declined by 36.8% during the first-level response to COVID-19, 23.5% during the second-level response, 14% during the third-level response in 2020, and 4.3% in 2021. Conclusion: The COVID-19 response reduced the number of people who sought and received diagnosis, treatment, and care for TB in Tianjin, China. Integrative programs to ensure access and continuity of TB services should be considered and dual testing for SARS-CoV-2 and M. tuberculosis may facilitate finding cases.


Asunto(s)
COVID-19 , Tuberculosis Pulmonar , Tuberculosis , Humanos , Femenino , Pandemias , COVID-19/diagnóstico , COVID-19/epidemiología , SARS-CoV-2 , Tuberculosis Pulmonar/diagnóstico , Tuberculosis Pulmonar/tratamiento farmacológico , Tuberculosis Pulmonar/epidemiología , Tuberculosis/diagnóstico , Tuberculosis/tratamiento farmacológico , Tuberculosis/epidemiología , China/epidemiología , Antituberculosos/uso terapéutico
5.
Biotechnol Lett ; 44(12): 1519-1526, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-36326958

RESUMEN

OBJECTIVE: To better understand the wetland restoration, the physicochemical property and microbial community in rhizosphere and bulk soil of the living and death Tamarix chinensis covered soil zones were studied. RESULTS: There were differences between growth conditions in the levels of soil pH, salinity, SOM, and nutrient. The living status of T. chinensis exhibited higher capacity of decreasing saline-alkali soil than the death condition of plants, and the living T. chinensis showed higher uptake of N, P, and K as compared with the death samples. Proteobacteria, Bacteroidota, and Chloroflexi were the predominant bacterial communities as revealed via high-throughput sequencing. CONCLUSIONS: It is great potential for using halophytes such as T. chinensis to ecological restore the coastal saline-alkali soil. This study could contribute to a better understanding of halophyte growth during the coastal phytoremediation process, and guide theoretically for management of T. chinensis population.


Asunto(s)
Tamaricaceae , Álcalis , Suelo , Plantas Tolerantes a la Sal , Salinidad
7.
Cell Cycle ; 20(18): 1907-1922, 2021 09.
Artículo en Inglés | MEDLINE | ID: mdl-34427546

RESUMEN

Background Ketamine-related cystitis (KC) has been researched in many clinical studies, but its exact mechanism is ambiguous and needs further research. Methods We established a KC rat model and analyzed physiological, biochemical, and urodynamic parameters of ketamine (KET)-related bladder injury. Bladder histologic feature, reactive oxygen species (ROS), autophagy-, apoptosis-, and endoplasmic reticulum stress (ERS)-related markers were examined by hematoxylin and eosin staining, Masson staining, ROS kit, quantitative real-time polymerase chain reaction, and western blot. In vitro, effects of 0.01, 0.1, and 1 mM KET on cell vitality, apoptosis, ROS level, autophagy-, apoptosis-, and ERS-related markers were examined again. Effects of KET-1 and salubrinal on complex formation, autophagy-, apoptosis-, and ERS-related markers were examined by Co-Immunoprecipitation and western blot. After transfection with shIRE1, complex formation, cell biological behaviors, ROS level, autophagy-, apoptosis-, and ERS-related markers were examined again. Results KET induced bladder hyperactivity and injury. KET facilitated urinary frequency, ROS production, and induced bladder histologic injury by activating autophagy-, apoptosis-, and ERS-related markers in rats. In vitro, KET (0.01, 0.1, and 1 mM) restrained cell vitality and elevated apoptosis and ROS level via activating autophagy-, apoptosis-, and ERS-related markers. Moreover, salubrinal reversed the promotion of KET-1 on complex formation, autophagy-, apoptosis-, and ERS-related marker expressions. After transfection with shIRE1, shIRE1 weakened complex formation induced by KET-1, and the effects of KET-1 on cells were offset by shIRE1. Conclusion KET enhanced autophagy and ERS in vivo and in vitro via restraining IRE1-TRAF2-ASK1-JNK pathway.


Asunto(s)
Autofagia/efectos de los fármacos , Cistitis/inducido químicamente , Cistitis/metabolismo , Estrés del Retículo Endoplásmico/efectos de los fármacos , Endorribonucleasas/metabolismo , Células Epiteliales/metabolismo , Ketamina/efectos adversos , MAP Quinasa Quinasa 4/metabolismo , MAP Quinasa Quinasa Quinasa 5/metabolismo , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Proteínas de la Membrana/metabolismo , Proteínas Serina-Treonina Quinasas/metabolismo , Factor 2 Asociado a Receptor de TNF/metabolismo , Animales , Apoptosis/efectos de los fármacos , Apoptosis/genética , Autofagia/genética , Línea Celular , Modelos Animales de Enfermedad , Estrés del Retículo Endoplásmico/genética , Endorribonucleasas/genética , Células Epiteliales/efectos de los fármacos , Humanos , Sistema de Señalización de MAP Quinasas/genética , Masculino , Proteínas Serina-Treonina Quinasas/genética , Ratas , Ratas Wistar , Especies Reactivas de Oxígeno/metabolismo , Transfección
8.
Diabetol Metab Syndr ; 12(1): 109, 2020 Dec 09.
Artículo en Inglés | MEDLINE | ID: mdl-33298110

RESUMEN

BACKGROUND: Long non-coding RNA cyclin-dependent kinase inhibitor 2B antisense RNA 1 (CDKN2B-AS1) has been reported to be related to diabetic nephropathy (DN) progression. However, the regulatory mechanisms of CDKN2B-AS1 in DN are unclear. METHODS: High glucose (HG) was used to induce human mesangial cells (HMCs) for establishing the DN model. Expression levels of CDKN2B-AS1, microRNA (miR)-15b-5p, wingless-Type family member 2B (WNT2B) mRNA in serum and HMCs were detected through quantitative real-time polymerase chain reaction (qRT-PCR). The viability and cell cycle progression of HMCs were determined with Cell Counting Kit-8 (CCK-8) or flow cytometry assays. The levels of several proteins and inflammatory factors in HMCs were analyzed by western blotting or enzyme-linked immunosorbent assay (ELISA). The relationship between CDKN2B-AS1 or WNT2B and miR-15b-5p was verified with dual-luciferase reporter assay. RESULTS: CDKN2B-AS1 and WNT2B were upregulated while miR-15b-5p was downregulated in serum of DN patients and HG-treated HMCs. CDKN2B-AS1 inhibition reduced HG-induced viability, cell cycle progression, ECM accumulation, and inflammation response in HMCs. CDKN2B-AS1 regulated WNT2B expression via competitively binding to miR-15b-5p. MiR-15b-5p inhibitor reversed CDKN2B-AS1 knockdown-mediated influence on viability, cell cycle progression, ECM accumulation, and inflammation response of HG-treated HMCs. The repressive effect of miR-15b-5p mimic on viability, cell cycle progression, ECM accumulation, and inflammation response of HG-treated HMCs was abolished by WNT2B overexpression. CONCLUSION: CDKN2B-AS1 regulated HG-induced HMC viability, cell cycle progression, ECM accumulation, and inflammation response via regulating the miR-15b-5p/WNT2B axis, provided a new mechanism for understanding the development of DN.

9.
Life Sci ; 239: 116868, 2019 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-31682847

RESUMEN

BACKGROUND: Sepsis is an inflammatory response undergoing the complicate pathophysiological changes for host defense against pathogens. Previous studies suggested that dexmedetomidine (DEX) was served to controlling the over-reactive inflammatory effects to protect from the sepsis-induced organ failure via modulating histone methylation. However, the genome-wide changes of histone methylations upon DEX for sepsis treatment were poorly explored. MATERIALS AND METHODS: The acute kidney injury (AKI) mouse model were induced by lipopolysaccharide (LPS). DEX and KDM5 (H3K4 demethylases) inhibitors were used to add additionally. H3K4me3 antibody was used to conduct the ChIP-seq assay in renal cortex tissues. RESULTS: We observed that the overall H3K4me3 levels were obviously declined in AKI group compared to the normal control. We further observed that the therapeutic effect of DEX was basically equal with CPI-455 and KDM5A-IN-1 but better than PBIT. The overall H3K4me3 level was reduced in AKI group compared to DEX (p = 0.008), and KDM5A-IN-1 groups (p = 0.022). The H3K4me3 enrichment of the multiple genes associated with inflammatory cytokines such as TNF-α, NOS2 and CCL2 increased in AKI model, but decreased upon DEX or KDM5A-IN-1 treatment. Consistently, transcription and protein levels of genes such as TLR4, MYD88, MTA1, PTGS2, CASP3 associated with NF-κB signaling pathway were all compromising after treated with DEX or KDM5A-IN-1 groups compared to AKI group. CONCLUSION: Taken together, our data determined that DEX could attenuate AKI through KDM5A inhibition in sepsis.


Asunto(s)
Dexmedetomidina/farmacología , Proteína 2 de Unión a Retinoblastoma/metabolismo , Sepsis/tratamiento farmacológico , Lesión Renal Aguda/prevención & control , Agonistas de Receptores Adrenérgicos alfa 2/farmacología , Animales , Citocinas/metabolismo , Dexmedetomidina/metabolismo , Riñón/metabolismo , Lipopolisacáridos/farmacología , Masculino , Ratones , Ratones Endogámicos C57BL , FN-kappa B/metabolismo , Sustancias Protectoras/farmacología , Insuficiencia Renal/tratamiento farmacológico , Insuficiencia Renal/metabolismo , Insuficiencia Renal/prevención & control , Sepsis/metabolismo , Transducción de Señal/efectos de los fármacos , Factor de Necrosis Tumoral alfa/metabolismo
10.
Perit Dial Int ; 39(2): 175-176, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-30858284

RESUMEN

Fungal peritonitis is a catastrophic complication of peritoneal dialysis (PD) and often requires termination of PD. It is usually caused by Candida species. Here we report a rare case of Exserohilum peritonitis. The patient was successfully treated with catheter removal and anti-fungal therapy.


Asunto(s)
Micosis , Diálisis Peritoneal , Peritonitis/microbiología , China , Humanos , Micosis/terapia , Diálisis Peritoneal/efectos adversos , Peritonitis/etiología , Peritonitis/terapia
11.
Sci Rep ; 7(1): 8827, 2017 08 18.
Artículo en Inglés | MEDLINE | ID: mdl-28821819

RESUMEN

CYP24A1 and CYP27B1 are critical genes determining 1α,25(OH)2D3 concentration and impacting on carcinogenesis. A case-control study including 528 colorectal cancer (CRC) patients and 605 cancer-free controls and a follow-up study with 317 cases were conducted in northeast China. Genotypes were tested by TaqMan Genotyping Assays. Individuals carrying the GG genotype of CYP27B1 G > T (rs10877012) exhibited decreased CRC risk compared with those with the TT genotype (ORadjusted (ORadj) = 0.57, 95% Confidence Interval (CI) = 0.38-0.84). Compared with the TT genotype, a significant association between the CC genotype of CYP27B1 C > T (rs4646536) and a reduced risk of CRC was observed (ORadj = 0.59, 95% CI = 0.40-0.88). We also observed significant combined effects of the two polymorphisms in CYP27B1 with dietary factors, including the intake of cereals, overnight meal, allium vegetables, pork, canned fruit, and braised fish, on CRC risk. These associations remained significant after Bonferroni correction for multiple comparisons. The Hazard Ration (HR) of patients with the AA genotype (CYP24A1 A > G, rs4809957) was 2.38 (95% CI = 1.30-4.37) when compared with the GG genotype. Thus, our findings suggested that two polymorphisms in CYP27B1 are associated with CRC susceptibility. CYP24A1 A > G (rs4809957) polymorphism may lead to a worse prognosis of CRC.


Asunto(s)
Neoplasias Colorrectales/epidemiología , Neoplasias Colorrectales/etiología , Dieta , Metabolismo Energético/genética , Polimorfismo de Nucleótido Simple , Vitamina D , 25-Hidroxivitamina D3 1-alfa-Hidroxilasa/genética , Adulto , Anciano , Anciano de 80 o más Años , Alelos , Estudios de Casos y Controles , China/epidemiología , Neoplasias Colorrectales/metabolismo , Neoplasias Colorrectales/mortalidad , Femenino , Genotipo , Humanos , Masculino , Persona de Mediana Edad , Oportunidad Relativa , Pronóstico , Modelos de Riesgos Proporcionales , Medición de Riesgo , Vitamina D/metabolismo , Vitamina D3 24-Hidroxilasa/genética
12.
Oncotarget ; 8(29): 47379-47388, 2017 Jul 18.
Artículo en Inglés | MEDLINE | ID: mdl-28537887

RESUMEN

Long-term dietary intake influences the structure and activity of microorganisms residing in the human gut. The immune response and gut microbiota have a mutual influence on the risk of colorectal cancer (CRC). This study examines the association of gut microbiota-related dietary factors and polymorphisms in the microRNA-binding site of the interleukin 13 gene (IL13) with the risk and prognosis of CRC. Three polymorphisms (rs847, rs848, and rs1295685) were selected for genotyping in a case-control study (513 cases, 572 controls), and 386 CRC patients were followed up. Two dietary factors closely related with gut microbiota (allium vegetables, overnight meal) were significantly associated with CRC development. Although the three SNPs showed no statistically significant associations with the risk and prognosis of CRC, a significant antagonistic interaction was found between rs848 (G-T) and allium vegetable intake (ORi (odds ratio of interaction), 0.92; 95% CI (confidence interval): 0.86, 0.99; P = 0.03); moreover, significant combined and synergistic interactions were observed for all three SNPs and overnight meal intake. This is the first report of significant combined and interactive effects between dietary factors and polymorphisms in the microRNA binding site of IL13 in CRC and may provide direct guidance on intake of allium vegetable and overnight meals for individuals with specific genetic variants of IL13 to modify their susceptibility to CRC.


Asunto(s)
Sitios de Unión , Neoplasias Colorrectales/etiología , Dieta , Interleucina-13/genética , MicroARNs/genética , Polimorfismo de Nucleótido Simple , Anciano , Alelos , Neoplasias Colorrectales/epidemiología , Neoplasias Colorrectales/mortalidad , Susceptibilidad a Enfermedades , Femenino , Microbioma Gastrointestinal , Genotipo , Humanos , Masculino , Persona de Mediana Edad , Oportunidad Relativa , Pronóstico
13.
Oncol Lett ; 2(6): 1275-1279, 2011 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-22848301

RESUMEN

Accumulating evidence shows that runt-related transcription factor 3 (Runx3) is a putative tumor suppressor in various types of cancer, the lower levels of which are associated with a less favorable cancer outcome. However, these studies were restricted to primary cancer lesions. Lymph node metastasis (LNM) is a significant factor in determining the prognosis of patients with gastric cancer and is a frequent target of chemotherapy. In the present study, we investigated the expression of Runx3 in the lymph nodes (LNs) of stomach carcinoma and the association of Runx3 expression with the prognosis of patients. The expression of Runx3 in LNs with and without metastasis was detected by reverse transcriptase-polymerase chain reaction (RT-PCR) and Western blotting. The positive rate of Runx3 mRNA in LNM specimens was significantly lower (28.4%, 21 out of 74) compared to that of the non-metastatic samples (33.3%, 9 out of 27, P<0.05). Similar findings were obtained by Western blotting. Univariate analysis revealed that the loss of Runx3 expression in LNs was not only associated with poor clinicopathological factors, such as LNM, distant organ metastasis, later clinicopathological stages and deep infiltration, but also with a lower 5-year survival rate and poorer prognosis. These results strongly suggest a potential diagnostic value of Runx3 expression in LNs and multiple pathways contributing to the outcome of patients with gastric cancer.

14.
Med Phys ; 37(9): 4971-81, 2010 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-20964216

RESUMEN

PURPOSE: To investigate the feasibility of high temporal resolution breast DCE-MRI using compressed sensing theory. METHODS: Two experiments were designed to investigate the feasibility of using reference image based compressed sensing (RICS) technique in DCE-MRI of the breast. The first experiment examined the capability of RICS to faithfully reconstruct uptake curves using undersampled data sets extracted from fully sampled clinical breast DCE-MRI data. An average approach and an approach using motion estimation and motion compensation (ME/MC) were implemented to obtain reference images and to evaluate their efficacy in reducing motion related effects. The second experiment, an in vitro phantom study, tested the feasibility of RICS for improving temporal resolution without degrading the spatial resolution. RESULTS: For the uptake-curve reconstruction experiment, there was a high correlation between uptake curves reconstructed from fully sampled data by Fourier transform and from undersampled data by RICS, indicating high similarity between them. The mean Pearson correlation coefficients for RICS with the ME/MC approach and RICS with the average approach were 0.977 +/- 0.023 and 0.953 +/- 0.031, respectively. The comparisons of final reconstruction results between RICS with the average approach and RICS with the ME/MC approach suggested that the latter was superior to the former in reducing motion related effects. For the in vitro experiment, compared to the fully sampled method, RICS improved the temporal resolution by an acceleration factor of 10 without degrading the spatial resolution. CONCLUSIONS: The preliminary study demonstrates the feasibility of RICS for faithfully reconstructing uptake curves and improving temporal resolution of breast DCE-MRI without degrading the spatial resolution.


Asunto(s)
Mama , Medios de Contraste , Imagen por Resonancia Magnética/métodos , Artefactos , Estudios de Factibilidad , Procesamiento de Imagen Asistido por Computador , Movimiento , Fantasmas de Imagen , Factores de Tiempo
15.
Radiology ; 257(1): 47-55, 2010 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-20713609

RESUMEN

PURPOSE: To develop a method that combines a fixed-T1, fuzzy c-means (FCM) technique with a reference region (RR) model (T1-FCM method) to estimate pharmacokinetic parameters without measuring the arterial input function or baseline T1, or T1(0), and to demonstrate its feasibility in the assessment of treatment response to neoadjuvant chemotherapy (NAC) in patients with breast cancer by using data from dynamic contrast material-enhanced magnetic resonance (MR) imaging. MATERIALS AND METHODS: This study was approved by the human investigation committees of the two participating institutions. All patients gave written informed consent. A conventional dual-flip-angle gradient-echo method was used to evaluate the effects of noise and the T1 in the tissue itself on the accuracy of T1 estimation. Both conventional RR and fixed-T1 methods were used to evaluate the effects of noise and preselected T1(0) on the estimation of pharmacokinetic parameters by means of a simulation study. Thirty-three women (age range, 32-66 years; mean age, 45 years) with pathologically proved breast tumors were examined to evaluate the feasibility of using the T1-FCM method as a means of assessing treatment response to NAC. A nonparametric Mann-Whitney U test was used to assess the difference in each of the MR imaging parameters between patients with a major histologic response to treatment and those with a nonmajor histologic response. RESULTS: With use of the dual-flip-angle method, the accuracy and distribution of T1 estimation are dependent on the T1 in the tissue itself. The T1-FCM method is more accurate than other methods and is relatively insensitive to the effects of noise and incorrect T1(0) selection. Preliminary clinical data revealed a significant difference (P < .01) in the change of the volume transfer constant after two cycles of NAC between the major and nonmajor histologic response groups. CONCLUSION: Results of the simulation study demonstrate that the T1-FCM method appears to be relatively insensitive to noisy dynamic contrast-enhanced MR imaging data. This method could prove useful in the evaluation of breast cancer therapy.


Asunto(s)
Neoplasias de la Mama/tratamiento farmacológico , Imagen por Resonancia Magnética/métodos , Adulto , Anciano , Mama/patología , Neoplasias de la Mama/patología , Neoplasias de la Mama/cirugía , Quimioterapia Adyuvante , Simulación por Computador , Medios de Contraste/farmacocinética , Estudios de Factibilidad , Femenino , Humanos , Persona de Mediana Edad , Terapia Neoadyuvante , Estudios Prospectivos , Estadísticas no Paramétricas , Resultado del Tratamiento
16.
Med Phys ; 36(8): 3786-94, 2009 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-19746812

RESUMEN

Dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) is the MRI technique of choice for detecting breast cancer, which can be roughly classified as either quantitative or semiquantitative. The major advantage of quantitative DCE-MRI is its ability to provide pharmacokinetic parameters such as volume transfer constant (Ktrans) and extravascular extracellular volume fraction (ve). However, semiquantitative DCE-MRI is still the clinical MRI technique of choice for breast cancer diagnosis due to several major practical difficulties in the implementation of quantitative DCE-MRI in a clinical setting, including (1) long acquisition necessary to acquire 3D T1(0) map, (2) challenges in obtaining accurate artery input function (AIF), (3) long computation time required by conventional nonlinear least square (NLS) fitting, and (4) many illogical values often generated by conventional NLS method. The authors developed a new analysis method to estimate pharmacokinetic parameters Ktrans and ve from clinical DCE-MRI data, including fixed T1(0) to eliminate the long acquisition for T1(0) map and "reference region" model to remove the requirement of measuring AIF. Other techniques used in our analysis method are (1) an improved formula to calculate contrast agent (CA) concentration based on signal intensity of SPGR data, (2) FCM clustering-based techniques for automatic segmentation and generation of a clustered concentration data set (3) an empirical formula for CA time course to fit the clustered data sets, and (4) linear regression for the estimation of pharmacokinetic parameters. Preliminary results from computer simulation and clinical study of 39 patients have demonstrated (1) the feasibility of their analysis method for estimating Ktrans and ve from clinical DCE-MRI data, (2) significantly less illogical values compared to NLS method (typically less than 1% versus more than 7%), (3) relative insensitivity to the noise in DCE-MRI data; (4) reduction in computation time by a factor of more than 30 times compared to NLS method on average, (5) high statistic correlation between the method used and NLS method (correlation coefficients: 0.941 for Ktrans and 0.881 for ve), and (6) the potential clinical usefulness of the new method.


Asunto(s)
Neoplasias de la Mama/metabolismo , Medios de Contraste/farmacocinética , Modelos Biológicos , Algoritmos , Neoplasias de la Mama/diagnóstico , Neoplasias de la Mama/patología , Análisis por Conglomerados , Simulación por Computador , Estudios de Factibilidad , Femenino , Humanos , Modelos Lineales , Factores de Tiempo
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