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1.
Biomacromolecules ; 2020 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-31955566

RESUMO

Current therapy for liver failure and concomitant hyperbilirubinemia faces the challenge of poor hemocompatibility and bleeding risks associated with the anticoagulant injection. Herein, heparin-mimetic biomacromolecule (HepMBm) with a similar degree of sulfation and anticoagulant properties to heparin was synthesized by imitating the structure of natural biomacromolecule heparin. Then HepMBm was used to prepare nanocomposite spheres based on reduced graphene oxide (rGO). The formation of a dual-network structure in the spheres endowed the spheres with improved dimensional stability. The proposed spheres exhibited outstanding blood compatibilities and excellent self-anticoagulant properties. The bilirubin adsorption experiments and whole blood bilirubin removal assay indicated that the spheres exhibited high bilirubin removal capability from whole blood (The removal ratio was 99.69%.). The spheres open new routes for a therapeutic strategy without a plasma separation system and heparin pump, which may be a step toward a lightweight wearable artificial liver.

2.
Nephrology (Carlton) ; 25(3): 264-272, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31709686

RESUMO

AIM: Vascular calcification (VC) is a common complication in chronic kidney disease (CKD) and has been shown to be associated with increased cardiovascular events and mortality. This study was to explore the role of Wnt-signaling pathway in CKD VC, and the association between VC and blood pressure variability (BPV) which is a risk factor of cardiovascular events. METHODS: Adult male Sprague-Dawley rats were divided into adenine-induced CKD group (n = 5), 5/6 nephrectomy CKD group (n = 5), sham group (n = 5) and control group (n = 5). Low-calcium-high-phosphate diets were introduced to induce vascular calcification. Both daytime (hour-to-hour during the day) and mid-term (day-to-day for 9 days) blood pressure (BP) were collected and analyzed for BPV metrics. At sacrifice, kidney, heart and aorta samples were taken for histological analyses. Calcium deposition in aorta was identified with Alizarin Red stain and graded. Immunohistochemistry stain and western blot were performed for Wnt3a, Wnt5a, ß-catenin, sclerostin, osteopontin, and α-SMA. RESULTS: Compared with control rats, CKD rats suffered from markedly severer VC (Grade 2.6 ± 0.2 and 1.8 ± 0.8 vs 0.0 ± 0.0 and 0.2 ± 0.4, P = .0010). VC was positively correlated with vascular Wnt3a and ß-catenin expression (P = .0032 and .0000), but not significantly associated with Wnta5a or sclerostin. Besides, CKD rats showed increased BPV (P < .001), which was also positively correlated with VC. CONCLUSION: We confirmed that CKD rats had enhanced Wnt-signaling in vascular tissue and severer aorta calcification together with increased BPV. Wnt pathway may be a potential target in future VC and BPV management in CKD.

3.
Curr Drug Metab ; 20(10): 799-803, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31608839

RESUMO

BACKGROUND: To investigate MiRNA-126 amounts in serum exosomes from allergic asthma patients as well as lung tissues of asthmatic mice, evaluating the expression of its target gene DNMT1 in mouse specimens. METHODS: MiRNA-126 amounts in serum exosomes from asthmatic patients were detected by real-time PCR. The mouse model of allergic asthma was established by OVA-sensitization, and allergic symptoms were recorded; serum IL-4 and sIgE level evaluation (ELISA), broncho alveolar lavage fluid (BALF) cell count and H&E staining were performed to assess airway inflammation. MiRNA-126 and DNMT1 levels in the lung of asthmatic and control mice were detected by real-time PCR; DNMT1 protein levels were detected by immunoblot. RESULTS: MiRNA-126 amounts in peripheral blood exosomes from patients with allergic asthma were significantly higher than that of healthy volunteers (P<0.05). The frequencies of scratching of both sides of the nose and sneezing were elevated within 10 min of excitation in asthmatic rats compared with controls. Meanwhile, OVA-sIgE and IL-4 levels were significantly higher in asthmatic animals than controls (P<0.05). In the asthma group, narrowed bronchial lumen and thickened wall were observed, and bronchial and peripheral vessels showed overt inflammatory cell infiltration. Eosinophil, neutrophil and mast cell amounts in the BALF of asthmatic mice were significantly higher than control values. Furthermore, lung miRNA-126 expression in asthmatic mice was significantly higher than that of controls. Finally, DNMT1 mRNA and protein levels were significantly lower in asthmatic animals compared with controls (P < 0.01). CONCLUSION: MiRNA-126 is highly expressed in serum exosomes from allergic asthma patients and lung tissues of asthmatic mice, suggesting that it may be involved in the pathogenesis of bronchial asthma.

4.
Ann Transl Med ; 7(16): 391, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31555705

RESUMO

Background: This study aimed to investigate whether hemodialysis (HD) affects tissue factor (TF), tissue factor pathway inhibitor (TFPI), and polymorphonuclear elastase (PMNE) in endstage renal disease (ESRD) patients when eliminating the effects of heparin. Also, to explore the interaction of TF, TFPI, and PMNE throughout a single HD session. Methods: We enrolled 57 ESRD patients who had undergone hemodialysis for >3 months as an experimental group. Plasma levels of TF, TFPI and PMNE were measured by ELISA in 24 ERSD patients on intermittent HD using low-molecular-weight heparin (LMWH) as anticoagulation (LMWH group) and 33 ESRD patients using citrate as anticoagulation (citrate group) at the start and at 1, 2 and 5 h of the HD session. Meanwhile,28 ESRD patients not on dialysis were enrolled as a control group and fasting venous blood samples were taken in the morning. Results: Compared with the control group, the plasma TFPI levels of the LMWH group and the citrate group were significantly higher (P=0.000, P=0.002, respectively) under baseline conditions as well as the plasma PMNE levels (P=0.001, P=0.02, respectively), whereas TF showed no difference (P=0.186). During HD with citrate, plasma TFPI decreased slightly (P=0.012) and PMNE increased significantly (P=0.008) at 1 h. The plasma TFPI levels of the citrate group correlate with PMNE at 2 and 5 h (P=0.001, P=0.008, respectively). Conclusions: ESRD patients on HD have significantly higher TFPI and PMNE levels compared to patients not on HD under baseline conditions, while TF levels were similar between the three groups. TFPI and PMNE are differently regulated, but the plasma levels correlated during HD in the citrate group. It might be possible that PMNE plays a role in anticoagulative activity through TFPI.

5.
Nanotechnology ; 30(37): 375201, 2019 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-31082806

RESUMO

Performance of plamson induced hot electrons-based photodetectors largely relies on the photon absorption capability. To improve the optical absorption, many perfect absorbers based on the periodic metallic nanostructures have been designed and fabricated through low-throughput, costly and time-consuming lithographic processes, which seriously limit the future potential applications of plasmonic hot electrons optoelectronics devices. Here, a large-scale, broadband absorber consisting of ITO film, ZnO layer, Au film and Al nanospike array substrate was designed and fabricated for hot electrons-based photodetection. The new designed absorber's absorptivity can be up to 70% in the broad wavelength range from 400 nm to 800 nm (even up to 90% in the wavelength range from 400-550 nm) and most of the absorption comes from the Au film, which is effective for the generation of hot electrons. The enhanced broadband absorption is ascribed to the surface plasmon polariton mode and localized surface plasmon resonance mode supported by the nanospike arrays. The influence of geometry and material parameters on the optical absorption properties is also specifically investigated through numerical simulation. The efficient and broadband absorption of a nanospikes device results in a much larger photocurrent compared with that of a planar reference device. Our approach, which is compatible with large-scale manufacturing, paves the way for the practical implementation of hot electrons-based optoelectronic devices.

6.
Nutr Diabetes ; 9(1): 14, 2019 04 03.
Artigo em Inglês | MEDLINE | ID: mdl-30944300

RESUMO

Chronic kidney disease-mineral and bone disorder (CKD-MBD) is a common complication in patients experiencing end-stage renal disease (ESRD). It includes abnormalities in bone and mineral metabolism and vascular calcification. Hyperphosphatemia is a major risk factor leading to morbidity and mortality in patients with chronic kidney disease. Increased mortality has been observed in patients with ESRD, with serum phosphorus levels of >5.5 mg/dL. Therefore, control of hyperphosphatemia is a major therapeutic goal in the prevention and treatment of CKD-MBD. The treatment of hyperphosphatemia includes decreasing intestinal phosphorus load and increasing renal phosphorus removal. Decreasing the intestinal load of phosphorus plays a major role in the prevention and treatment of CKD-MBD. Among the dietary sources of phosphorus, some of the commonly prescribed medications have also been reported to contain phosphorus. However, drugs are often ignored even though they act as a potential source of phosphorus. Similarly, although proteins are the major source of dietary phosphorus, reducing protein intake can increase mortality in patients with CKD. Recently, the importance of phosphorus/protein ratio in food have been reported to be a sensitive marker for controlling dietary intake of phosphorus. This review summarizes the progress in the research on phosphate content in drugs as an excipient and the various aspects of dietary management of hyperphosphatemia in patients with CKD, with special emphasis on dietary restriction of phosphorus with low dietary phosphate/protein ratio.

7.
Artif Organs ; 43(10): 988-1001, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30932185

RESUMO

Coronary artery calcifications (CACs) are common among maintenance hemodialysis (MHD) patients and associated with increased morbidity and mortality due to cardiovascular events. The insight into chronic kidney disease-mineral and bone disorder (CKD-MBD) established a correlation between dysregulated mineral metabolism and CACs. This study aimed to identify the association of mineral content outside of bone (MCOB) with CACs and cardiovascular events in MHD patients. In the pilot prospective study with no intervention, patients underwent body composition assessment by body composition monitor after hemodialysis and computed tomography examination using the Agatston scoring method simultaneously within a week. The primary end point included cardiovascular events and cardiovascular death. Correlations and receiver operating characteristic analysis elucidated the associations of MCOB with CACs; multivariate analysis assessed the cardiovascular risk for groups with different MCOB. One hundred three eligible patients with an average age of 48 (35-63) years old were enrolled and followed up to 12 (11-12.5) months, among which 52.4% had detectable CACs at baseline. MCOB showed an inverse correlation with Agatston score and significantly discriminated the patients with Agatston score > 0 (AUC = 0.737; P < 0.001) and 400 (AUC = 0.733; P < 0.001). MCOB ≤ 9.2657 mg/kg was an independent risk factor for CACs (OR = 4.853; P = 0.044) and strong predictor for cardiovascular morbidity and mortality (HR = 10.108; P = 0.042), as well as rehospitalization (HR = 2.689; P = 0.004). MCOB inversely correlated with the presence and extent of CACs, and could discriminate Agatston score > 0 and 400, which also presented as an independent indicator for CKD-MBD and 1-year cardiovascular prognosis in adult MHD patients. Additional studies are required for identifying this issue.


Assuntos
Cálcio/análise , Minerais/análise , Diálise Renal , Insuficiência Renal Crônica/complicações , Calcificação Vascular/etiologia , Adulto , Idoso , Composição Corporal , Doenças Ósseas/diagnóstico , Doenças Ósseas/etiologia , Vasos Coronários/patologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Insuficiência Renal Crônica/diagnóstico , Insuficiência Renal Crônica/terapia , Resultado do Tratamento , Calcificação Vascular/diagnóstico
8.
Blood Purif ; 48(1): 43-50, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30808851

RESUMO

BACKGROUND: Blood pressure variability (BPV) is a potential prognostic predictor for all-cause mortality. OBJECTIVES: We conducted a retrospective cohort study to compare the prognostic value of long-term BPV with intra-dialytic BPV in hemodialysis (HD) patients. MATERIALS AND METHODS: We included 611 HD patients and collected their baseline blood pressure (BP) measurements for 1 year and monitored them for 40 months. Long-term BPV was assessed by pre-dialysis BP SD and pre-dialysis absolute BP residual metric. Intra-dialytic BPV was assessed by intra-dialytic BP average real variability and intra-dialytic absolute BP residual. RESULTS: Long-term systolic BPV showed a weak correlation with mean BP, but a stronger correlation with intra-dialytic BPV. High long-term systolic blood pressure (SBP) SD and long-term SBP residual metrics were associated with high all-cause mortality (p = 0.0084 and 0.0056, respectively), while no such association was found for intra-dialytic BPV or diastolic BPV. According to receiver operating characteristic curve with mortality as dependent variable, long-term SBP residual metric showed the strongest prognostic ability (area under curve [AUC] 0.679, p = 0.0006), which was even stronger in patients with BP ≥140/90 mm Hg (AUC 0.713, p = 0.0004). After completely adjusting for confounders, long-term SBP residual metric remained significantly associated with all-cause mortality (hazard ratio 1.628 per quartile; 95% CI 1.086-2.441). CONCLUSIONS: Our results suggest long-term SBP residual metric to be a better predictor of all-cause mortality in HD patients, which could be used as an additional target for BP management.


Assuntos
Pressão Sanguínea , Causas de Morte , Diálise Renal , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Modelos de Riscos Proporcionais , Curva ROC , Diálise Renal/efeitos adversos , Diálise Renal/métodos , Estudos Retrospectivos , Fatores de Risco , Fatores de Tempo
9.
J Nephrol ; 32(4): 627-634, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-30666583

RESUMO

Arteriovenous fistula (AVF) strategy has been recommended in clinical guidelines for a long time due to the survival benefits associated with it. However, the underlying mechanism still needs to be explored. This retrospective cohort study included 611 patients who received hemodialysis in West China Hospital Medical Center between January 1, 2014 and December 31, 2014. Patient characteristics, dialysis parameters, and 1-year blood pressure records were collected at baseline. Echocardiographic changes and clinical outcomes were assessed during the 59-month follow-up. Our study showed that fistulas were associated with lower long-term systolic blood pressure (SBP) standard deviation (SD) (P < 0.0001), lower long-term SBP residual metric (P < 0.0001), and lower intradialytic SBP residual (P = 0.001). Fistulas were also associated with a higher but non-significant proportion of the newly developed left ventricular (LV) hypertrophy (8.29% vs. 6.78%, P = 0.116) and increased LV volume (8.29% vs. 4.52%, P = 0.139), as well as a lower proportion of the newly developed left ventricular ejection fraction (LVEF) dysfunction (1.62% vs. 2.82%, P = 0.586). After a median of 59-month follow-up, catheter group showed a higher risk of cardiovascular events (hazard ratio [HR] 1.21; 95% confidence interval [95%CI] 1.01-1.52), all-cause infection (HR 1.25; 95%CI 1.07-1.47), and access-related infection (HR 2.88; 95%CI 1.76-4.68). However, the advantage of fistulas only retained in low-albumin subgroup (serum albumin < 40 g/l) except for access-related infections. Our results suggested the possible attribution of BPV and other patient factors to fistula-associated survival benefits.

10.
Carbohydr Polym ; 202: 116-124, 2018 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-30286984

RESUMO

In this study, we report a mussel-inspired approach to fabricate heparin-immobilized cellulose (HeTaCe) gel beads with self-anticoagulative and biocompatible properties which can selectively remove low density lipoprotein (LDL) from whole blood directly. First, a phase inversion technique was applied to prepare cellulose gel beads. Then the as-prepared gel beads were dipped into a mixed solution of heparin and tannic acid in phosphate buffered saline (PBS, pH 8.5) to obtain HeTaCe gel beads. Blood compatibility experiments indicated that the HeTaCe gel beads could suppress complement activation as well as contact activation and prolong the clotting times to the upper detect limits (activated partial thromboplastin time >600 s and thrombin time >180 s) of the automated blood coagulation analyzer. An ideal adsorption capacity of LDL in vitro was achieved by the HeTaCe gel beads with an amount of 79.1 mg/g. Besides, dynamic column adsorption test further demonstrated a selective adsorption of LDL without a significant reduction of high density lipoprotein (HDL) in a simulative hemoperfusion system. It is believed that the HeTaCe gel beads will be quite appealing to future clinical practice aiming at lowering LDL and improving the outcomes of patients with high cardiovascular risk.


Assuntos
Bivalves/química , Celulose/química , Heparina/química , Lipoproteínas LDL/isolamento & purificação , Adsorção , Adulto , Animais , Celulose/síntese química , Celulose/farmacologia , Géis/química , Voluntários Saudáveis , Humanos , Lipoproteínas LDL/sangue , Lipoproteínas LDL/química , Masculino , Estrutura Molecular , Tamanho da Partícula , Propriedades de Superfície
11.
Int J Biol Macromol ; 117: 392-400, 2018 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-29777805

RESUMO

Safe and efficient carboxymethyl chitosan (CMC)-based heparin-mimicking cross-linked beads (CMC/PAMPS) as adsorbents for the clearance of low-density lipoprotein-cholesterol (LDL-c) in blood purification were prepared through hydrogen bonding interactions followed with in situ cross-linking with 2-acrylamido-2-methyl-1-propanesulfonicacid (AMPS). Fourier transform infrared spectra (FTIR), two-dimensional correlation FTIR spectroscopy (2D IR), thermal gravimetric analysis (TGA) and energy dispersive X-ray spectrometer (EDS) demonstrated the successful synthesis of CMC/PAMPS beads. The porous structures of the beads may contribute to the adsorption of toxins. Owing to their favorable hydrophilicity, when contacted with blood, the beads showed excellent hemocompatibility. The hemolysis ratios for all the beads were less than 5%, the thromboplastin time of CMC/PAMPS10 beads exceed 600 s, and they can suppress contact activation and complement activation effectively. Additionally, the beads have no obvious cytotoxicity with endothelial cells, thus could be used as a safe adsorbent for blood purification. Moreover, the CMC/PAMPS10 beads possessed a LDL-c adsorption capacity of 24.8 mg/g under static adsorption and a LDL-c adsorption capacity of 8.2 mg/g in the simulation of hemoperfusion for whole blood, due to the large surface areas and high density of functional groups. Meanwhile, the concentration of high-density lipoprotein-cholesterol (HDL-c) was almost unaffected. In general, the safe adsorbent with high LDL-c adsorption capacity has great potentials for hemoperfusion and other clinical applications.


Assuntos
Sangue/metabolismo , Quitosana/análogos & derivados , Reagentes para Ligações Cruzadas/química , Heparina/síntese química , Microesferas , Adsorção , Coagulação Sanguínea , Morte Celular , Sobrevivência Celular , Quitosana/síntese química , Hemólise , Células Endoteliais da Veia Umbilical Humana/metabolismo , Humanos , Lipoproteínas HDL/metabolismo , Lipoproteínas LDL/metabolismo , Espectroscopia de Infravermelho com Transformada de Fourier , Temperatura Ambiente , Água/química
12.
Artif Organs ; 41(12): 1127-1134, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28544060

RESUMO

The specific timing for discontinuing renal replacement therapy (RRT) in acute kidney injury (AKI) patients is debatable. The predictive abilities of variables at the time of discontinuation of RRT for the long-term prognoses of patients have not been explored. This study aimed to explore the prognostic factors upon discontinuation of RRT for long-term chronic dialysis and death of patients with acute RRT-requiring AKI, thus improving decision making regarding the discontinuation of RRT and the follow-up of patients thereafter. A cohort of 302 AKI patients who required acute RRT and remained alive and free of dialysis for at least 30 days after discharge from January 2009 to December 2012 were followed up. The predictive abilities of general characteristics, RRT details, and variables upon discontinuation of RRT for long-term chronic dialysis and all-cause death were evaluated using Cox proportional hazards models. Kaplan-Meier analysis with a log-rank test was used to compare the survival curves between the strata of levels of good predictors upon discontinuation of RRT. After a median follow-up time of 4.1 years, 20 (6.6%) patients initiated chronic dialysis and 56 (18.5%) patients died. A higher CysC level upon discontinuation of RRT (HR 1.520, 95% CI 1.082-2.135; P = 0.016), comorbid chronic kidney disease, and a higher non-renal Charlson comorbidity index (CCI) were independently predictive for chronic dialysis. The hemoglobin level upon discontinuation of RRT was inversely predictive of death (HR 0.986, 95% CI 0.973-0.999; P = 0.035), and comorbid malignancy, the presence of multiple organ dysfunction syndrome, and a higher non-renal CCI also predicted death. Urine output upon discontinuation of RRT was marginally inversely predictive of death (HR 0.997, 95% CI 0.994-1.000; P = 0.056). Patients who discontinued RRT with CysC levels <2.97 mg/L, hemoglobin levels >85 g/L, and urine output >1130 mL/24 h showed significantly higher non-chronic dialysis and survival rates according to a log-rank test. Our study suggested that upon discontinuation of RRT, higher serum CysC levels had the most promising predictive value for long-term chronic dialysis, and lower hemoglobin levels predicted long-term death; lower urine output also marginally predicted long-term death. Based on the remission of the comprehensive condition, lower CysC levels and higher hemoglobin levels and urine output should be considered in the decision to stop RRT. Patients showing worse levels of these indices upon discontinuation of RRT should undergo stricter follow-up and treatment to improve long-term outcomes.


Assuntos
Lesão Renal Aguda/diagnóstico , Lesão Renal Aguda/terapia , Terapia de Substituição Renal , Lesão Renal Aguda/sangue , Lesão Renal Aguda/mortalidade , Adulto , Causas de Morte , Estudos de Coortes , Cistatina C/sangue , Feminino , Seguimentos , Hemoglobinas/análise , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Prognóstico , Modelos de Riscos Proporcionais , Terapia de Substituição Renal/mortalidade
13.
Kaohsiung J Med Sci ; 33(4): 201-206, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28359408

RESUMO

Conventional laparoscopic cholecystectomy (CLC) is currently the standard of surgical procedure for gallstone disease. Robotic cholecystectomy (RC) has revolutionized the field of minimally invasive surgery; it is safe and ergonomic, but expensive. The aim of this study is to compare the medical resource utilization and clinical outcomes between the two procedures. This study was conducted retrospectively by assessing data of the clinical outcomes and medical resource of 78 patients receiving RC and 367 patients receiving CLC. We reviewed the data of operation times, length of hospital stay, hospital charges, outpatient department visits, outpatient department service charges, and postoperative complications, which were retrieved from the health information system (HIS) database in this hospital. Patients in both groups had similar demographic and clinical features. The RC group had longer length of hospital stay (p=0.056), significantly longer operation time (p=0.035), and much more hospital charges (p=0.001). The RC group, however, experienced less postoperative complication rates (average 3.8% vs. 20.4%, p=0.001). Conversion rate was 1.9% in the CLC group versus 0% in the RC group (p=0.611). Most complications were mild, and following the Clavien-Dindo classification, there were two cases (2.5%) Grade I for the RC group; 50 cases (13.6%) Grade I and 14 cases (3.81%) Grade II for the CLC group (p<0.001 and 0.001, respectively). Procedure-related complications of Grade IIIa status were encountered in nine patients (2.45%) in the CLC group and none in the RC group (p=0.002).The RC group consumed more medical resources in the index hospitalization; however, they experienced significantly less postoperative complications.


Assuntos
Colecistectomia Laparoscópica/estatística & dados numéricos , Recursos em Saúde/estatística & dados numéricos , Procedimentos Cirúrgicos Robóticos/estatística & dados numéricos , Colecistectomia Laparoscópica/efeitos adversos , Demografia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Procedimentos Cirúrgicos Minimamente Invasivos/estatística & dados numéricos , Complicações Pós-Operatórias/etiologia , Procedimentos Cirúrgicos Robóticos/efeitos adversos , Resultado do Tratamento
14.
Sci Rep ; 6: 24918, 2016 04 26.
Artigo em Inglês | MEDLINE | ID: mdl-27114050

RESUMO

Surface defect of nanomaterials is an important physical parameter which significantly influences their physical and chemical performances. In this work, high concentration of surface oxygen vancancies (SOVs) are successfully introduced on {001} facets exposed BiOBr nanosheets via a simple surface modification using polybasic carboxylic acids. The chelation interaction between carboxylic acid anions and Bi(3+) results in the weakness of Bi-O bond of BiOBr. Afterwards, under visible-light irradiation, the oxygen atoms would absorb the photo-energy and then be released from the surface of BiOBr, leaving SOVs. The electron spin resonance (ESR), high-resolution transmission electron microscopy (HRTEM), and UV-vis diffuse reflectance spectra (DRS) measurements confirm the existence of SOVs. The SOVs can enhance the absorption in visible light region and improve the separation efficiency of photo-generated charges. Hence, the transformation rate of adsorbed O2 on the as-prepared BiOBr with SOVs to superoxide anion radicals (•O2(-)) and the photocatalytic activity are greatly enhanced. Based on the modification by several carboxylic acids and the photocatalytic results, we propose that carboxylic acids with natural bond orbital (NBO) electrostatic charges absolute values greater than 0.830 are effective in modifying BiOBr.

15.
Dalton Trans ; 45(6): 2444-53, 2016 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-26660856

RESUMO

Porous sphere-like tricobalt tetraoxide (Co3O4)-cobalt chloride hydrate (CoCl2·6H2O, CCH) heterojunctions are obtained using a one-step facile solution combustion route. The heterostructure is confirmed by XRD, HRTEM, and XPS measurements. Their photocatalytic performances are evaluated by the degradation of methyl orange (MO) and the reduction removal of Cr(VI) ions under visible light irradiation. The heterojunction containing 81.5 wt% Co3O4 and 18.5 wt% CCH exhibits the highest photocatalytic performance, for which the pseudo-first-order reaction rate constant is 10.0 and 8.7 times that of pure Co3O4 towards MO degradation and Cr(vi) reduction, respectively. This enhancement in activity can be attributed to the effective electron transfer from the conduction band of Co3O4 to that of CCH, which is verified with a double increase of the photocurrent valve of the heterojunction sample electrode in comparison with the bare Co3O4 sample electrode. Electron paramagnetic resonance, fluorescence spectrophotometry and scavenger experiments indicate that photo-induced holes, and hydroxyl and superoxide anion radicals are the active species responsible for the photo-oxidation of MO. The reasons for the formation of these species are discussed and proposed based on the band gap structures of Co3O4 and CCH. The recycling experiment results indicate that the activity can be regained by a remedial experiment.

16.
Dalton Trans ; 44(40): 17859-66, 2015 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-26399735

RESUMO

A Ti species modified g-C3N4 photocatalyst was synthesized via an in situ hydrothermal route and the subsequent low-temperature calcination. The hydrothermal process results in not only the fabrication of TiO2/g-C3N4 heterojunctions, but also the coordination between Ti species and g-C3N4, which are verified by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The electrical resistance test confirms that the coordination can improve the electrical conductivity of composites and can make the charge transfer easier. The photoluminescence (PL) and photocurrent measurements exhibit that the hybridization enhances the separation efficiency of photo-induced electrons and holes. As a result, the Ti species modified g-C3N4 photocatalysts exhibit much higher photocatalytic H2 evolution than the simple heterojunction of TiO2/g-C3N4 obtained via a microwave method and the mechanical mixture of TiO2 and g-C3N4 under visible-light irradiation. The coordination mechanism and synthesis route of TiO2/g-C3N4 heterojunctions are proposed.

17.
J Neurooncol ; 105(1): 27-44, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21373966

RESUMO

The neural adhesion/recognition protein L1 (L1CAM; CD171) has been shown or implicated to function in stimulation of cell motility in several cancer types, including high-grade gliomas. Our previous work demonstrated the expression and function of L1 protein in stimulation of cell motility in rat glioma cells. However, the mechanism of this stimulation is still unclear. This study further investigated the function of L1 and L1 proteolysis in human glioblastoma multiforme (GBM) cell migration and invasion, as well as the mechanism of this stimulation. L1 mRNA was found to be present in human T98G GBM cell line but not in U-118 MG grade III human glioma cell line. L1 protein expression, proteolysis, and release were found in T98G cells and human surgical GBM cells by Western blotting. Exosome-like vesicles released by T98G cells were purified and contained full-length L1. In a scratch assay, T98G cells that migrated into the denuded scratch area exhibited upregulation of ADAM10 protease expression coincident with loss of surface L1. GBM surgical specimen cells exhibited a similar loss of cell surface L1 when xenografted into the chick embryo brain. When lentivirally introduced shRNA was used to attenuate L1 expression, such T98G/shL1 cells exhibited significantly decreased cell motility by time lapse microscopy in our quantitative Super Scratch assay. These cells also showed a decrease in FAK activity and exhibited increased focal complexes. L1 binding integrins which activate FAK were found in T98G and U-118 MG cells. Addition of L1 ectodomain-containing media (1) rescued the decreased cell motility of T98G/shL1 cells and (2) increased cell motility of U-118 MG cells but (3) did not further increase T98G cell motility. Injection of L1-attenuated T98G/shL1 cells into embryonic chick brains resulted in the absence of detectable invasion compared to control cells which invaded brain tissue. These studies support a mechanism where glioma cells at the edge of a cell mass upregulate ADAM10 to proteolyze surface L1 and the resultant ectodomain increases human glioma cell migration and invasion by binding to integrin receptors, activating FAK, and increasing turnover of focal complexes.


Assuntos
Movimento Celular , Quinase 1 de Adesão Focal/metabolismo , Glioma/metabolismo , Glioma/patologia , Molécula L1 de Adesão de Célula Nervosa/metabolismo , Proteínas ADAM/genética , Proteínas ADAM/metabolismo , Proteína ADAM10 , Secretases da Proteína Precursora do Amiloide/genética , Secretases da Proteína Precursora do Amiloide/metabolismo , Animais , Western Blotting , Adesão Celular , Proliferação de Células , Embrião de Galinha , Ativação Enzimática , Exossomos , Imunofluorescência , Quinase 1 de Adesão Focal/genética , Humanos , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Invasividade Neoplásica , Molécula L1 de Adesão de Célula Nervosa/antagonistas & inibidores , Molécula L1 de Adesão de Célula Nervosa/genética , RNA Mensageiro/genética , RNA Interferente Pequeno/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Células Tumorais Cultivadas
18.
Cancer Cell Int ; 10: 34, 2010 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-20840789

RESUMO

BACKGROUND: Neural recognition molecule L1CAM, which is a key protein involved in early nervous system development, is known to be abnormally expressed and shed in several types of cancers where it participates in metastasis and progression. The distinction of L1CAM presence in cancerous vs. normal tissues has suggested it to be a new target for cancer treatment. Our current study focused on the potential role of soluble L1CAM in breast cancer cell adhesion to extracellular matrix proteins, migration, and invasion. RESULTS: We found L1 expression levels were correlated with breast cancer stage of progression in established data sets of clinical samples, and also were high in more metastatic breast cancer cell lines MDA-MB-231 and MDA-MB-435, but low in less migratory MDA-MB-468 cells. Proteolysis of L1 into its soluble form (sL1) was detected in cell culture medium from all three above cell lines, and can be induced by PMA activation. Over-expression of the L1 ectodomain in MDA-MB-468 cells by using a lentiviral vector greatly increased the amount of sL1 released by those cells. Concomitantly, cell adhesion to extracellular matrix and cell transmigration ability were significantly promoted, while cell invasion ability through Matrigel™ remained unaffected. On the other hand, attenuating L1 expression in MDA-MB-231 cells by using a shRNA lentiviral vector resulted in reduced cell-matrix adhesion and transmigration. Similar effects were also shown by monoclonal antibody blocking of the L1 extracellular region. Moreover, sL1 in conditioned cell culture medium induced a directional migration of MDA-MB-468 cells, which could be neutralized by antibody treatment. CONCLUSIONS: Our data provides new evidence for the function of L1CAM and its soluble form in promoting cancer cell adhesion to ECM and cell migration. Thus, L1CAM is validated further to be a potential early diagnostic marker in breast cancer progression and a target for breast cancer therapy.

19.
PLoS One ; 4(2): e4450, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19214221

RESUMO

BACKGROUND: Phosphatase of regenerating liver-3 (PRL-3) is a member of the novel phosphatases of regenerating liver family, characterized by one protein tyrosine phosphatase active domain and a C-terminal prenylation (CCVM) motif. Though widely proposed to facilitate metastasis in many cancer types, PRL-3's cellular localization and the function of its CCVM motif in metastatic process remain unknown. METHODOLOGY/PRINCIPAL FINDINGS: In the present study, a series of Myc tagged PRL-3 wild type or mutant plasmids were expressed in B16F1 melanoma cells to investigate the relationship between PRL-3's cellular localization and metastasis. With immuno-fluorescence microcopy and cell adhesion/migration assay in vitro, and an experimental passive metastasis model in vivo, we found that CCVM motif is critical for the localization of PRL-3 on cell plasma membrane and the lung metastasis of melanoma. In particular, Cystine170 is the key site for prenylation in this process. CONCLUSIONS/SIGNIFICANCE: These results suggest that cellular localization of PRL-3 is highly correlated with its function in tumor metastasis, and inhibition of PRL-3 prenylation might be a new approach to cancer therapy.


Assuntos
Membrana Celular/enzimologia , Melanoma , Metástase Neoplásica , Proteínas de Neoplasias/metabolismo , Proteínas Tirosina Fosfatases/metabolismo , Animais , Sequência de Bases , Adesão Celular/fisiologia , Linhagem Celular Tumoral , Movimento Celular/fisiologia , Humanos , Melanoma/metabolismo , Melanoma/patologia , Camundongos , Camundongos Endogâmicos C57BL , Proteínas de Neoplasias/genética , Prenilação , Proteínas Tirosina Fosfatases/genética , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo
20.
Mol Med ; 13(3-4): 151-9, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17592549

RESUMO

Phosphatase of regenerating liver-3 (PRL-3) has been proposed to promote the invasion of tumor cells to metastasis sites. However, the effect of PRL-3 on spontaneous metastasis has not been clearly demonstrated, and whether PRL-3 could become a new therapeutic target in malignant tumor is still unknown. In this study, we used PRL-3 siRNA as a molecular medicine to specifically reduce the expression of PRL-3 in B16-BL6 cells, a highly metastatic melanoma cell line. In vitro, PRL-3 siRNA significantly inhibited cell adhesion and migration, but had no effect on cell proliferation. In the spontaneous metastatic tumor model in vivo, PRL-3 siRNA treatment remarkably inhibited the proliferation of primary tumor, prevented tumor cells from invading the draining lymph nodes, and prolonged the life span of mice. Therefore, our results indicate that PRL-3 plays a critical role in promoting the whole process of spontaneous metastasis and tumor growth initiation, and that inhibiting PRL-3 will improve malignant tumor therapy.


Assuntos
Proteínas Imediatamente Precoces/metabolismo , Melanoma Experimental/patologia , Melanoma Experimental/fisiopatologia , Metástase Neoplásica/prevenção & controle , Proteínas Tirosina Fosfatases/metabolismo , RNA Interferente Pequeno/farmacologia , Animais , Proteínas Imediatamente Precoces/genética , Técnicas In Vitro , Camundongos , Camundongos Endogâmicos C57BL , Transplante de Neoplasias , Proteínas Tirosina Fosfatases/genética , Transplante Homólogo , Células Tumorais Cultivadas
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