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1.
J Am Heart Assoc ; 9(5): e013699, 2020 Mar 03.
Artigo em Inglês | MEDLINE | ID: mdl-32070205

RESUMO

Background Primary aldosteronism (PA) is associated with higher atrial fibrillation prevalence and other cardiovascular complications. However, the effect of target treatment to prevent new-onset atrial fibrillation (NOAF) remains unclear. This study investigated incidence of NOAF under different treatment strategies in patients with PA. Methods and Results We analyzed longitudinal data for patients with PA without atrial fibrillation history from 1997 to 2009 within the National Health Insurance Research Database in Taiwan. Patients with essential hypertension matched by propensity score were enrolled as controls. The primary outcome measurement was NOAF, and secondary outcome measurements were mortality, major cardiac and cardiac/cerebrovascular events, and a combined end point of NOAF and mortality. We identified 2202 patients with PA (534 adrenalectomy, 1668 mineralocorticoid receptor antagonist [MRA] therapy) and 8808 essential hypertension controls with mean follow-up of 4.4 years. In primary outcome measurement, patients with PA who underwent adrenalectomy had a lower incidence of NOAF (adjusted hazard ratio; 0.28, P=0.011) than controls. In contrast, the patients with PA who received MRA therapy had comparable risk of NOAF (adjusted hazard ratio, 1.20; P=0.224). In secondary outcome measurement, patients with PA who underwent adrenalectomy had a lower rate of mortality and combined end point of NOAF and mortality than controls. Patients with PA who received MRA therapy had a higher risk of mortality, major cardiac and cardiac/cerebrovascular events, and combined NOAF with mortality than the essential hypertension controls. Conclusions Compared with patients with essential hypertension, patients with PA who underwent adrenalectomy had a lower incidence of NOAF. However, this finding was not observed in patients with PA who received MRA therapy with a lower dose. Differences between the 2 strategies may reduce with a higher dose of MRA therapy.

2.
Biochim Biophys Acta Mol Basis Dis ; 1866(3): 165627, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-31785407

RESUMO

Macrophages play an important role in aldosterone-induced myocardial fibrosis, in which the first key steps are macrophage recruitment and infiltration. We hypothesized that IL-6 may be a key mediator of aldosterone-induced macrophage recruitment and infiltration. To test this hypothesis, we designed cell studies with a human monocytic cell line THP-1 that with monocyte/macrophage functions to explore the signaling pathway of aldosterone-induced macrophage infiltration, and further investigated the phenomenon and consequent pathway in aldosterone-infused mice studies. The results showed that aldosterone induced the expression of IL-6 via mineralocorticoid receptors, and enhanced THP-1 cell migration and infiltration. Further experiments using a protease array and siRNA revealed that expressions of MMP-1 and MMP-9 were associated with aldosterone-induced macrophage infiltration. In addition, aldosterone-induced MMP-1 and MMP-9 expressions were mediated via cyclooxygenase-II and prostaglandin E2/EP-2 and EP-4 receptors. In aldosterone-infused mice, mRNA expressions of MMP-1, MMP-9 and COX-2 in peripheral blood monocytic cells were significantly increased. Moreover, the number of mouse macrophage-restricted F4/80 protein-positive cells in the myocardium was significantly higher in the aldosterone-infused mice compared with control mice. The increase in F4/80-positive cells in the myocardium was suppressed in the aldosterone-infused mice with the aldosterone antagonist eplerenone or anti-IL-6 antibody treatment. In conclusion, interleukin-6 played an important role in aldosterone-induced macrophage recruitment and infiltration in the myocardium.

3.
J Investig Med ; 68(2): 371-377, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31630138

RESUMO

Estimated glomerular filtration rate (eGFR) is an important topic in patients with primary aldosteronism (PA). However, the relationship between left ventricular structure and eGFR is unclear. We conducted a prospective, observational, and cross-sectional study to analyze 168 patients with PA and 168 propensity score-matched patients with essential hypertension (EH) as the control group, matched by age, gender, and systolic blood pressure. In the patients with PA, the eGFR was not correlated with left ventricular mass index (LVMI; r=-0.065, p=0.404), while in the patients with EH, the eGFR was negatively correlated with LVMI (r=-0.309, p<0.001). To test whether eGFR had a non-linear relationship with LVMI among the patients with PA, we stratified the patients with PA according to the tertile of eGFR (low, medium, and high tertile). The medium tertile of patients had a significantly lower LVMI than those in the other two tertiles (LVMI: 143.5±41.6, 120.5±40.5, and 133.1±34.3 g/m2, from the lowest to highest tertile of eGFR; analysis of covariance p=0.032). The medium tertile of eGFR is associated with lowest LVMI. Patients with PA with high and low eGFR were associated with higher LVMI. The findings implied that the reasons for an increased LVMI in patients with PA may be different to those in patients with EH.

4.
Med Sci Sports Exerc ; 52(2): 269-277, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31479003

RESUMO

PURPOSE: Treatments that improve outcomes in patients with heart failure with reduced ejection fraction (HFrEF) have shown no benefits for those with heart failure with preserved ejection fraction (HFpEF). Our study aimed to investigate the effect of inhaled iloprost on myocardial performance during exercise in HFpEF. METHODS: The study participants were enrolled from the ILO-HOPE trial (NCT03620526), a prospective randomized, double-blind, placebo-controlled study that was designed to investigate the effects of iloprost on cardiovascular hemodynamics during exercise in patients with HFpEF. Subjects were randomized 1:1 to inhalation of iloprost or placebo for 5 min. Two-dimensional transthoracic echocardiography with high temporal resolution was implemented to measure left ventricular (LV) longitudinal strain, LV diastolic function, and RV function both at rest and during supine exercise at 20-W workload. RESULTS: LV global longitudinal strain (GLS) in response to exercise increased more in the iloprost group (LV GLS, -24.96 ± 1.20 vs -20.75 ± 3.00, P < 0.001). Iloprost also resulted in greater increment of LV GLS during exercise (ΔLV GLS, +6.02 ± 1.39 vs +3.44 ± 0.80, P < 0.001). Moreover, iloprost use was associated with enhancement of LV diastolic function, RV systolic function, and relief of pulmonary hypertension during exercise. CONCLUSIONS: In patients with HFpEF, inhaled iloprost favorably improved myocardial performance during exercise by increasing LV GLS reserve, decreasing LV diastolic filling load, and reducing stress-induced pulmonary hypertension and thereby improving RV systolic function. Larger studies are needed to validate the result and long-term benefits of iloprost in patients with HFpEF.

5.
Artigo em Inglês | MEDLINE | ID: mdl-31873901

RESUMO

Vertical wells are commonly used for recirculating leachate into a landfill which can offer significant environmental and economic benefits. However, in some cases, the leachate collection and removal system (LCRS) at the bottom is overloaded and clogged due to biological and chemical processes. This results in a relatively high leachate level which could pose a threat to landfill slope stability. This study develops a three-dimensional landfill slope model with vertical recirculation wells and then investigates the effect of LCRS clogging on leachate recirculation and slope stability in terms of leachate saturation, pore water pressure, and factor of safety (FS) of a landfill slope. The results show that with an increase in clogging level that is characterized by an increased leachate level, the pore water pressure below the well injection screen is significantly increased by leachate recirculation, giving rise to a decreased slope FS value. In such conditions, the landfill slope formed by highly anisotropic waste is more likely to suffer instability. To prevent this kind of slope failure, a safe injection pressure of vertical recirculation wells is proposed for a wide range of parameter combinations involving waste anisotropy, clogging level, and the setback distance from the slope surface. This design guideline can be used to control the injection pressure in leachate recirculation applications and contributes to a better understanding of the slope stability of a bioreactor landfill.

6.
J Am Heart Assoc ; 8(22): e013263, 2019 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-31718437

RESUMO

Background Primary aldosteronism is the most common cause of secondary hypertension and is associated with left ventricular hypertrophy. However, whether aldosterone excess is responsible for left ventricular (LV) diastolic dysfunction is unknown. Methods and Results We prospectively enrolled 129 patients with aldosterone-producing adenoma and 120 patients with essential hypertension, and analyzed their clinical, biochemical, and echocardiographic data, including tissue Doppler images. The patients with aldosterone-producing adenoma were reevaluated 1 year after adrenalectomy. After propensity score matching, there were 105 patients in each group. The patients with aldosterone-producing adenoma had worse diastolic function than the patients with essential hypertension, as reflected by lower e' (P<0.001) and higher E/e' (P=0.003). Multivariate analysis showed that LV diastolic function was significantly correlated with age (P<0.001), sex (P<0.001), body mass index (P=0.002), systolic blood pressure (P=0.004), creatinine (P=0.008), and log-transformed aldosterone-renin ratio (P=0.003). After adrenalectomy, the patients with aldosterone-producing adenoma had significant improvements in LV diastolic function as reflected by an increase in e' (P=0.003) and decrease in E/e' (P=0.002). The change in E/e' was independently correlated with baseline E/e' (P<0.001) and change in LV mass index (P=0.006). Conclusions The patients with primary aldosteronism had worse LV diastolic function than the patients with essential hypertension after propensity score matching, and this could be reversed after adrenalectomy, suggesting that aldosterone excess may induce LV diastolic dysfunction.

7.
Int J Mol Sci ; 20(20)2019 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-31640178

RESUMO

Primary aldosteronism (PA) is characterized by excess production of aldosterone from the adrenal glands and is the most common and treatable cause of secondary hypertension. Aldosterone is a mineralocorticoid hormone that participates in the regulation of electrolyte balance, blood pressure, and tissue remodeling. The excess of aldosterone caused by PA results in an increase in cardiovascular and cerebrovascular complications, including coronary artery disease, myocardial infarction, stroke, transient ischemic attack, and even arrhythmia and heart failure. Endothelial dysfunction is a well-established fundamental cause of cardiovascular diseases and also a predictor of worse clinical outcomes. Accumulating evidence indicates that aldosterone plays an important role in the initiation and progression of endothelial dysfunction. Several mechanisms have been shown to contribute to aldosterone-induced endothelial dysfunction, including aldosterone-mediated vascular tone dysfunction, aldosterone- and endothelium-mediated vascular inflammation, aldosterone-related atherosclerosis, and vascular remodeling. These mechanisms are activated by aldosterone through genomic and nongenomic pathways in mineralocorticoid receptor-dependent and independent manners. In addition, other cells have also been shown to participate in these mechanisms. The complex interactions among endothelium, inflammatory cells, vascular smooth muscle cells and fibroblasts are crucial for aldosterone-mediated endothelial dysregulation. In this review, we discuss the association between aldosterone and endothelial function and the complex mechanisms from a molecular aspect. Furthermore, we also review current clinical research of endothelial dysfunction in patients with PA.

8.
Hypertension ; 74(3): 623-629, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31352825

RESUMO

Primary aldosteronism (PA) is hemodynamically independently associated with arterial wall stiffness as assessed by pulse wave velocity (PWV) compared with essential hypertension. Arterial wave reflection parameters derived from pulse wave analysis, such as forward and backward wave amplitudes (Pf and Pb), are promising vascular markers to predict cardiovascular outcomes in addition to PWV. These vascular parameters have never been studied in patients with PA before. In study part A, we prospectively enrolled 67 patients with PA and 132 patients with essential hypertension. In study part B, another 54 patients with PA were enrolled. Heart-carotid PWV was measured, and carotid pressure waveforms were recorded to calculate Pf, Pb, and augmentation index at baseline (part A and B) and 6 months after treatment (part B). The results showed that the patients with PA had significantly higher Pf (P=0.001), Pb (P=0.01), and PWV (P=0.021) than the patients with essential hypertension. In univariate correlation analysis, both log Pf and Pb were significantly correlated with age, office blood pressure, serum potassium level, log PWV, and the presence of PA. However, only Pb was significantly correlated with log plasma renin activity and log aldosterone to renin ratio. In multivariate analysis, log Pf was significantly correlated with the presence of PA (P=0.001), male sex, age, and mean arterial blood pressure. Pb was significantly correlated with the presence of PA (P=0.031), age, and mean arterial pressure. Six months after treatment, Pf and Pb decreased significantly. In conclusion, the patients with PA had significantly increased wave reflections compared with the patients with essential hypertension. Our results provide clinical evidence of aldosterone-related extensive vascular dysfunction of the arterial system.


Assuntos
Anti-Hipertensivos/uso terapêutico , Hipertensão Essencial/diagnóstico , Hipertensão Essencial/tratamento farmacológico , Hiperaldosteronismo/complicações , Hipertensão/tratamento farmacológico , Adulto , Aldosterona/sangue , Anti-Hipertensivos/farmacologia , Área Sob a Curva , Pressão Arterial/efeitos dos fármacos , Estudos de Coortes , Estudos Transversais , Feminino , Seguimentos , Humanos , Hiperaldosteronismo/diagnóstico , Hipertensão/etiologia , Modelos Lineares , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Análise de Onda de Pulso , Medição de Risco , Estatísticas não Paramétricas , Resultado do Tratamento , Adulto Jovem
9.
Cardiovasc Drugs Ther ; 33(4): 471-479, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31069576

RESUMO

BACKGROUND: Although cardiovascular (CV) disease is the leading cause of mortality and morbidity in dialysis patients, there is little evidence to guide the use of antiplatelet agents in dialysis patients. METHOD: A nationwide database (Registry for Catastrophic Illnesses) for Taiwan, which has data from nearly all patients who received dialysis therapy from 1995 to 2008, was used. This is a population-based cohort study with time to event analyses to estimate the relation between antiplatelet agent use and outcomes. Hazard ratios were calculated to evaluate the effect of antiplatelet agent use on the risk of major CV events and mortality. Baseline characteristics were matched by propensity score (PS). RESULTS: A total of 71,835 were included, and 10,595 (14.7%) patients received an anti-platelet agent. The median value of follow-up days was 61.6 months. After PS-based matching, 9598 patients who used an antiplatelet agent and 23,794 non-users were included in the analysis. After PS matching, there was no difference between patients using an antiplatelet agent or not in CV events (p = 0.672) and total mortality (p = 0.529). A subgroup analysis of different usage periods of antiplatelet agents indicated that CV events and total mortality were similar in those who used antiplatelet agents for short or long durations. In subgroup analysis, there was also no difference between patients with a different modality of dialysis (hemodialysis or peritoneal dialysis), different antiplatelet agents (aspirin, clopidogrel, and/or ticlopidine) or patients with/without previous cardiovascular disease in CV events and total mortality. CONCLUSIONS: Antiplatelet agent usage does not reduce CV events and total mortality in dialysis patients.

11.
Endocrinol Metab (Seoul) ; 33(4): 429-434, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30513556

RESUMO

As diagnostic techniques have advanced, primary aldosteronism (PA) has emerged as the most common cause of secondary hypertension. The excess of aldosterone caused by PA resulted in not only cardiovascular complications, including coronary artery disease, myocardial infarction, arrhythmia, and heart failure, but also cerebrovascular complications, such as stroke and transient ischemic attack. Moreover, PA is associated more closely with these conditions than is essential hypertension. In this review, we present up-to-date findings on the association between PA and cerebrovascular diseases.

12.
J Hypertens ; 36(3): 701-702, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29384989
13.
J Hypertens ; 36(2): 353-360, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-28902663

RESUMO

BACKGROUND: Primary aldosteronism is associated with a higher incidence of left ventricular (LV) hypertrophy and diastolic dysfunction than essential hypertension. However, systolic function via endocardial measurements is similar between patients with primary aldosteronism and essential hypertension. Speckle-tracking echocardiography is a sensitive tool which can detect subclinical impairments in systolic function. The aim of this study was to investigate aldosterone-induced subclinical impairments in systolic function. METHODS: We prospectively enrolled patients with primary aldosteronism and essential hypertension and analyzed their clinical data, biochemical data, and echocardiographic parameters, including myocardial strain [global longitudinal strain (GLS)]. RESULTS: Thirty-six patients with primary aldosteronism and 31 patients with essential hypertension were enrolled for analysis. The patients with primary aldosteronism had significantly lower serum potassium levels, lower plasma renin activity, higher aldosterone-to-renin ratio (ARR), and higher 24-h urinary aldosterone levels than patients with essential hypertension. With regards to echocardiographic parameters, the patients with primary aldosteronism had a thicker ventricular wall and higher LV mass index than those with essential hypertension. Most importantly, we found significant degradation of GLS in the patients with primary aldosteronism compared with those with essential hypertension (-17.84 ±â€Š2.36 vs. -20.13 ±â€Š2.32, P < 0.001). In correlation analysis, GLS was significantly correlated with serum potassium level, LV mass index, log-transformed plasma renin activity, log-transformed ARR, and log-transformed 24-h urinary aldosterone levels (all P < 0.05). Multivariate linear regression analysis further identified log-transformed ARR (ß = 0.771, 95% confidence interval: 0.011-1.530, P = 0.047), and log-transformed 24-h urinary aldosterone level (ß = 1.765, 95% confidence interval: 0.01-3.529, P = 0.050) as independent factors correlated with GLS. CONCLUSION: Patients with primary aldosteronism have a lower magnitude of GLS than patients with essential hypertension, suggesting that aldosterone induces a subclinical decline in LV systolic function.


Assuntos
Aldosterona/sangue , Hipertensão Essencial/fisiopatologia , Hiperaldosteronismo/diagnóstico por imagem , Hiperaldosteronismo/fisiopatologia , Hipertrofia Ventricular Esquerda/diagnóstico por imagem , Disfunção Ventricular Esquerda/diagnóstico por imagem , Adulto , Idoso , Aldosterona/urina , Ecocardiografia/métodos , Hipertensão Essencial/sangue , Hipertensão Essencial/diagnóstico por imagem , Feminino , Coração/fisiopatologia , Humanos , Hiperaldosteronismo/sangue , Hiperaldosteronismo/complicações , Hipertensão , Hipertrofia Ventricular Esquerda/etiologia , Hipertrofia Ventricular Esquerda/fisiopatologia , Masculino , Pessoa de Meia-Idade , Miocárdio , Potássio/sangue , Estudos Prospectivos , Renina/sangue , Sístole , Disfunção Ventricular Esquerda/etiologia , Disfunção Ventricular Esquerda/fisiopatologia
14.
Waste Manag Res ; 34(12): 1307-1315, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27821683

RESUMO

Bioreactor landfills use leachate recirculation to enhance the biodegradation of municipal solid waste and accelerate landfill stabilisation, which can provide significant environmental and economic benefits. Vertical wells are operated as a major method for leachate recirculation systems. The objectives of this article are to analyse the leachate migration in bioreactor landfills using vertical wells and to offer theoretical basis for the design of leachate recirculation systems. A three-dimensional numerical model was built using FLAC-3D, and this model can consider the saturated and unsaturated flow of leachate within anisotropic waste to reflect the actual conditions. First, main influence factors of leachate migration were analysed, including the vertical well height, hydraulic conductivity, and anisotropic coefficient, in a single-well recirculation system. Then, the effects of different configurations of a group-well system were studied and the optimal well spacing was obtained. Some key design parameters (e.g. the recirculation flow rate, volume of impact zone, radius of impact zone and time to reach steady state) were also evaluated. The results show that the hydraulic conductivity has a great impact on the optimal height of vertical wells and uniform configuration is the best option in terms of both volume of impact zone and time to reach steady state.


Assuntos
Reatores Biológicos , Modelos Teóricos , Eliminação de Resíduos/instrumentação , Instalações de Eliminação de Resíduos , Poluentes Químicos da Água , Anisotropia , Desenho de Equipamento , Hidrologia/métodos , Eliminação de Resíduos/métodos , Reprodutibilidade dos Testes
15.
Guang Pu Xue Yu Guang Pu Fen Xi ; 35(1): 118-21, 2015 Jan.
Artigo em Chinês | MEDLINE | ID: mdl-25993832

RESUMO

Quartz in the veins at the Shenxigou section of Wenchuan earthquake fault zone was investigated by micro-Raman spectroscopic measurement, and the distribution of compressive stress in the fault zone was estimated by the frequency shifts of the 464 cm-1 vibrational mode of quartz grains in the veins. It was showed that the 464 cm-1 peak arising from the quartz grains in the veins near the fault plane shifts by 3. 29 cm-1 , and the corresponding compressive stress is 368. 63 MPa, which is significantly lower than the stress accumulation on both sides due to multi-stage events. Stress accumulation increased with moving away from the fault plane in the footwall with the offset of the 464 cm-1 peak arising from the quartz grains in the veins increasing, which can reach 494. 77 MPa at a distance of 21 m with a high offset of 4. 40 cm-1 of the 464 cm-1 peak. The compressive stress gets the maximum value of 519.87 MPa at a distance of 10 m from the fault plane in the hanging wall with the offset of the 464 cm-1 peak arising from the quartz grains in the veins being 4. 62 cm-1, followed by a sudden drop in stress accumulation, and it drops to 359. 59 MPa at a distance of 17 m. Because of moving away from the foult plane at the edge of the foult zone, the stress drops to 359. 59 MPa with a small value of 464 cm-1 peak offset 3. 21 cm-1 at a distance of 27 m from the fault plane in the hanging wall due to the little effect by the fault activity. Therefore, the stress of Wenchuan earthquake fault zone is partially released, but the rest of the stress distribution is uneven, and there is also a high stress accumulation in somewhere in the fault zone, which reflects that the mechanical properties of the rocks in the fault zone have a characteristic of unevenness in space.

16.
Artigo em Inglês | MEDLINE | ID: mdl-24496671

RESUMO

Oval cells have a potential to differentiate into a variety of cell lineages including hepatocytes and biliary epithelia. Several models have been established to activate the oval cells by incorporating a variety of toxins and carcinogens, alone or combined with surgical treatment. Those models are obviously not suitable for the study on human hepatic oval cells. It is necessary to establish a new and efficient model to study the human hepatic oval cells. In this study, the hepatocyte growth factor (HGF) and epidermal growth factor (EGF) were used to induce differentiation of mouse embryonic stem (ES) cells into hepatic oval cells. We first confirmed that hepatic oval cells derived from ES cells, which are bipotential, do exist during the course of mouse ES cells' differentiation into hepatic parenchymal cells. RT-PCR and transmission electron microscopy were applied in this study. The ratio of Sca-1+/CD34+ cells sorted by FACS in the induction group was increased from day 4 and reached the maximum on the day 8, whereas that in the control group remained at a low level. The differentiation ratio of Sca-1+/CD34+ cells in the induction group was significantly higher than that in the control group. About 92.48% of the sorted Sca-1+/CD34+ cells on the day 8 were A6 positive. Highly purified A6+/Sca-1+/CD34+ hepatic oval cells derived from ES cells could be obtained by FACS. The differentiation ratio of hepatic oval cells in the induction group (up to 4.46%) was significantly higher than that in the control group. The number of hepatic oval cells could be increased significantly by HGF and EGF. The study also examined the ultrastructures of ES-derived hepatic oval cells' membrane surface by atomic force microscopy. The ES-derived hepatic oval cells cultured and sorted by our protocols may be available for the future clinical application.


Assuntos
Diferenciação Celular/fisiologia , Células-Tronco Embrionárias/citologia , Fígado/citologia , Células-Tronco/citologia , Animais , Antígenos CD34/genética , Antígenos CD34/metabolismo , Antígenos Ly/genética , Antígenos Ly/metabolismo , Diferenciação Celular/efeitos dos fármacos , Diferenciação Celular/genética , Linhagem Celular , Células-Tronco Embrionárias/metabolismo , Células-Tronco Embrionárias/ultraestrutura , Fator de Crescimento Epidérmico/farmacologia , Citometria de Fluxo , Regulação da Expressão Gênica no Desenvolvimento/efeitos dos fármacos , Fator de Crescimento de Hepatócito/farmacologia , Fígado/metabolismo , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Proteínas dos Microfilamentos/metabolismo , Microscopia de Força Atômica , Microscopia Eletrônica de Transmissão , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Células-Tronco/metabolismo , Células-Tronco/ultraestrutura , Fatores de Tempo
17.
J Pharm Anal ; 4(1): 14-25, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29403865

RESUMO

Ultra-performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry (UPLC-Q-TOF/MS) was developed to identify the absorbed parent components and metabolites in rat bile, plasma and urine after oral administration of Radix Paeoniae Alba extract (RPAE). A total of 65 compounds were detected in rat bile, plasma and urine samples, including 11 parent compounds and 54 metabolites. The results indicated that glucuronidation, hydroxylation and methylation were the major metabolic pathways of the components of RPAE. Furthermore, the results of this work demonstrated that UPLC-Q-TOF/MS combined with MetaboLynx™ software and mass defect filtering (MDF) could provide unique high throughput capabilities for drug metabolism study, with excellent MS mass accuracy and enhanced MSE data acquisition. With the MSE technique, both precursor and fragment mass spectra can be simultaneously acquired by alternating between high and low collision energy during a single chromatographic run.

18.
Biochem Biophys Res Commun ; 407(2): 301-6, 2011 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-21382342

RESUMO

Soluble CD4 (sCD4), anti-CD4 antibody, and anti-gp120 antibody have long been regarded as entry inhibitors in human immunodeficiency virus (HIV) therapy. However, the interactions between these HIV entry inhibitors and corresponding target molecules are still poorly understood. In this study, atomic force microscopy (AFM) was utilized to investigate the interaction forces among them. We found that the unbinding forces of sCD4-gp120 interaction, CD4 antigen-antibody interaction, and gp120 antigen-antibody interaction were 25.45 ± 20.46, 51.2 2 ± 34.64, and 89.87 ± 44.63 pN, respectively, which may provide important mechanical information for understanding the effects of viral entry inhibitors on HIV infection. Moreover, we found that the functionalization of an interaction pair on AFM tip or substrate significantly influenced the results, implying that we must perform AFM force measurement and analyze the data with more caution.


Assuntos
Anticorpos Monoclonais/imunologia , Reações Antígeno-Anticorpo , Antígenos CD4/imunologia , Proteína gp120 do Envelope de HIV/imunologia , Microscopia de Força Atômica , Humanos
19.
Guang Pu Xue Yu Guang Pu Fen Xi ; 31(12): 3264-8, 2011 Dec.
Artigo em Chinês | MEDLINE | ID: mdl-22295773

RESUMO

The morphological symptom of phosphorus deficiency at early stage is similar to the appearance of leaf aging process in preliminary phase, so that visual diagnostics of phosphorus deficiency in mini-cucumber plants at early stage is practically impossible. Near infrared reflectance spectra contain information about differences in compositions of leaf tissues between phosphorus-deficient plants and healthy plants. In the present paper, near infrared reflectance spectroscopy was used to provide diagnostic information on phosphorus deficiency of mini-cucumber plants grown under non-soil conditions. Near infrared spectra was collected from 90 leaves of mini-cucumber plants. Raw cucumber spectra was preprocessed by SNV and divided into 27 intervals. The top 10 principal components (PCs) were extracted as the input of BP-ANN classifiers by principal component analysis (PCA) while the values of nutrient deficient were used as the output variables of BP-ANN and three layers BP-ANN discrimination model was built. The best experiment results were based on the top 3 principal components of No. 7 interval when the spectra was divided into 27 intervals and identification rates of the ANN model are 100% in both training set and the prediction set. The overall results show that NIR spectroscopy combined with BP-ANN can be efficiently utilized for rapid and early diagnostics of phosphorus deficiency in mini-cucumber plants.


Assuntos
Cucumis sativus/química , Fósforo/análise , Espectroscopia de Luz Próxima ao Infravermelho , Modelos Teóricos , Fósforo/deficiência , Folhas de Planta , Análise de Componente Principal
20.
Guang Pu Xue Yu Guang Pu Fen Xi ; 30(12): 3199-202, 2010 Dec.
Artigo em Chinês | MEDLINE | ID: mdl-21322205

RESUMO

To improve and simplify the prediction model of carotenoid content of cucumber leaves, genetic algorithm (GA) combined with Metropolis acceptance criterion of simulated annealing algorithm (SAA) as well as interval partial least square (iPLS) were proposed and used to establish the calibration models of carotenoid content against cucumber leaves spectra. The cucumber leaves spectra data were divided into 40 intervals, among which 7 subsets, i. e. No. 3, 4, 14, 18, 21, 32 and 33, were selected by SAA-GA-iPLS. The comparison was made between SAA-GA-iPLS and traditional genetic algorithm interval partial least square (GA-iPLS), and the result of this study shows that SAA-GA-iPLS was better than traditional genetic algorithm interval partial least square (GA-iPLS).


Assuntos
Carotenoides/análise , Espectroscopia de Luz Próxima ao Infravermelho/métodos , Algoritmos , Calibragem , Cucumis sativus/química , Análise dos Mínimos Quadrados , Modelos Teóricos , Folhas de Planta/química
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