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1.
Anal Sci ; 2024 Apr 22.
Article in English | MEDLINE | ID: mdl-38649628

ABSTRACT

Analyzing new psychoactive substances (NPSs) in forensic laboratories present a formidable challenge globally. Within illicit drug analysis, gas chromatography-mass spectrometry (GC-MS) emerges as a robust analytical tool. This study endeavors to assess and compare peak resolution in the analysis of illicit drugs, specifically focusing on 21 synthetic cathinones, encompassing 9 cathinone isomers. Varied GC-MS operating conditions, including distinct GC-MS columns and thermal gradients, were systematically employed for the simultaneous analysis of these synthetic cathinones. The study utilized HP-1 nonpolar and HP-5MS low-bleed columns to achieve optimal analyte resolution through modulation of GC-MS oven conditions. Mass spectra were meticulously recorded within a mass-to-charge (m/z) range spanning from 40 to 500 in full scan mode. The data showed that the cathinone isomers slightly differed in retention times and mass spectra. The GC oven conditions affected the peak resolution for chromatographic separation even with the same column. The peak resolution improved using a slower thermal gradient heat speed with a prolonged analysis time. Conclusively, the interplay of GC columns and thermal gradients emerged as pivotal factors impacting peak resolution in the analysis of illicit drugs. These empirical insights contribute to a nuanced understanding of peak resolution dynamics and facilitate the identification of synthetic cathinones, including their isomers, in seized materials through the judicious application of GC-MS methodologies.

2.
World J Clin Cases ; 11(19): 4684-4691, 2023 Jul 06.
Article in English | MEDLINE | ID: mdl-37469726

ABSTRACT

BACKGROUND: Podocyte infolding glomerulopathy (PIG) is a newly described and rare glomerular disease. To date, only approximately 40 cases have been reported globally. CASE SUMMARY: A 26-year-old female patient presented to our hospital with a complaint of intermittent edema of both lower limbs over the past 2 years. The patient was diagnosed with PIG. She was prescribed corticosteroid therapy in other hospitals during the initial stage, to which she had responded poorly and had developed femoral head necrosis. Therefore, we administered immunosuppressants, renin-angiotensin system inhibitors, combined with traditional Chinese medicine. The patient was followed for 1 year, during which her clinical condition improved. CONCLUSION: Integrated Chinese and Western medicine may be effective for PIG treatment, which requires active intervention to improve prognosis.

3.
Micromachines (Basel) ; 14(5)2023 Apr 24.
Article in English | MEDLINE | ID: mdl-37241543

ABSTRACT

The structure used in this study is as follows: substrate/PMMA/ZnS/Ag/MoO3/NPB/Alq3/LiF/Al. Here, PMMA serves as the surface flattening layer, ZnS/Ag/MoO3 as the anode, NPB as the hole injection layer, Alq3 as the emitting layer, LiF as the electron injection layer, and aluminum as the cathode. The properties of the devices with different substrates were investigated using P4 and glass, developed in the laboratory, as well as commercially available PET. After film formation, P4 creates holes on the surface. The light field distribution of the device was calculated at wavelengths of 480 nm, 550 nm, and 620 nm using optical simulation. It was found that this microstructure contributes to light extraction. The maximum brightness, external quantum efficiency, and current efficiency of the device at a P4 thickness of 2.6 µm were 72,500 cd/m2, 1.69%, and 5.68 cd/A, respectively. However, the maximum brightness of the same structure with PET (130 µm) was 9500 cd/m2. The microstructure of the P4 substrate was found to contribute to the excellent device performance through analysis of the AFM surface morphology, film resistance, and optical simulation results. The holes formed by the P4 substrate were created solely by spin-coating the material and then placing it on a heating plate to dry, without any special processing. To confirm the reproducibility of the naturally formed holes, devices were fabricated again with three different emitting layer thicknesses. The maximum brightness, external quantum efficiency, and current efficiency of the device at an Alq3 thickness of 55 nm were 93,400 cd/m2, 1.7%, and 5.6 cd/A, respectively.

4.
Membranes (Basel) ; 12(12)2022 Dec 07.
Article in English | MEDLINE | ID: mdl-36557145

ABSTRACT

We use polyethylene glycol as an additive to explore how the hydrogen bonding of this additive changes the properties of SA8 blended sulfonated polyetheretherketone (SPEEK) composite films. We mixed a 5%wt polyethylene glycol solution into a 12.5%wt SA8 solution, and then prepared a film with a total weight of 40 g at a ratio of 1:99. The SA8 (PEG) solution was prepared and then mixed with 5%wt SPEEK solution, and a film-forming solution with a total weight of 8g in different mixing ratios was created. Polyethylene glycol (PEG) was mixed into the sulfonated polyarylether polymer SA8 to form physical cross-linking. Therefore, the sulfonated polyether ether ketone SPEEK was mixed in, and it exhibited good thermal stability and dimensional stability. However, there was some decrease in proton conductivity as the proportion of SPEEK increased. Although SPEEK mixed with sulfonated polymer reduces the proton conductivity, the physical cross-linking of PEG can improve the proton conductivity of the composite membrane, and adding SPEEK can not only solve the problem of the high sulfonation film swelling phenomenon, it can also improve the dimensional stability of the film through the hydrogen bonding force of PEG and obtain a composite film with excellent properties.

5.
Membranes (Basel) ; 12(10)2022 Oct 05.
Article in English | MEDLINE | ID: mdl-36295733

ABSTRACT

This study fabricated a composite ePTFE-backed proton-exchange membrane by filling the pores on the ePTFE backing with sulfonated polyarylene ethers through an externally supplied electric field. The morphology changes were observed under an SEM. The results suggested that the application of an electric field had led to the effective filling of pores by polymers. In addition, the composite membrane featured good dimensional stability and swelling ratio, and its water uptake, proton conductivity and component efficiency increased with voltage. It is found in this study that the external application of an electric field resulted in the effective filling of pores in the ePTFE by sulfonated polyarylene ether polymers and, thus, an improved composite membrane performance.

6.
Membranes (Basel) ; 12(6)2022 May 31.
Article in English | MEDLINE | ID: mdl-35736289

ABSTRACT

In this study, a series of high molecular weight ionomers of hexaarylbenzene- and fluorene-based poly(arylene ether)s were synthesized conveniently through condensation and post-sulfonation modification. The use a of blending method might increase the stacking density of chains and affect the formation both of interchain and intrachain proton transfer clusters. Multiscale phase separation caused by the dissolution and compatibility differences of blend ionomer in high-boiling-point solvents was examined through analysis and simulations. The blend membranes produced in this study exhibited a high proton conductivity of 206.4 mS cm−1 at 80 °C (increased from 182.6 mS cm−1 for precursor membranes), excellent thermal resistance (decomposition temperature > 200 °C), and suitable mechanical properties with a tensile strength of 73.8−77.4 MPa. As a proton exchange membrane for fuel cell applications, it exhibits an excellent power efficiency of approximately 1.3 W cm−2. Thus, the ionomer membranes have strong potential for use in proton exchange membrane fuel cells and other electrochemical applications.

7.
Sci Rep ; 12(1): 6552, 2022 04 21.
Article in English | MEDLINE | ID: mdl-35449366

ABSTRACT

Acute myocardial infarction (AMI) is one of the main causes of death in the world, and the incidence of AMI is increasing in the young population. Drug-coated balloon (DCB) has become an effective concept for the treatment of in-stent restenosis, small vessel disease, bifurcation lesions, high blood risk conditions, and even de novo large vessel disease. To ensure whether DCB can play an alternative role in AMI, we conducted a comprehensive meta-analysis of randomized controlled trials (RCTs) to evaluate the efficacy and safety of DCB in the treatment of AMI. Electronic databases were searched for RCTs that compared DCB with stent for AMI. The primary outcome was major adverse cardiac events (MACEs), the secondary outcome was late lumen loss (LLL). RevMan 5.3 software and RStudio software were used for data analysis. Five RCTs involving 528 patients with 6-12 months of follow-up were included. There was no significant difference in the incidence of MACEs between DCB group and stent group (RR, 0.85; 95% CI 0.42 to 1.74; P = 0.66). Lower LLL was shown in DCB group (WMD, - 0.29; 95% CI - 0.46 to - 0.12; P < 0.001). This meta-analysis of RCT showed that DCB might provide a promising way on AMI compared with stents. Rigorous patients' selection and adequate predilation of culprit lesions are necessary to optimize results and prevent bailout stent implantation.PROSPERO registration number: CRD42020214333.


Subject(s)
Angioplasty, Balloon, Coronary , Coronary Artery Disease , Coronary Restenosis , Myocardial Infarction , Angioplasty, Balloon, Coronary/adverse effects , Coated Materials, Biocompatible , Coronary Artery Disease/etiology , Coronary Restenosis/etiology , Humans , Myocardial Infarction/complications , Randomized Controlled Trials as Topic , Treatment Outcome
8.
Membranes (Basel) ; 11(8)2021 Aug 15.
Article in English | MEDLINE | ID: mdl-34436389

ABSTRACT

Series of partially fluorinated sulfonated poly(arylene ether)s were synthesized through nucleophilic substitution polycondensation from three types of diols and superhydrophobic tetra-trifluoromethyl-substituted difluoro monomers with postsulfonation to obtain densely sulfonated ionomers. The membranes had similar ion exchange capacities of 2.92 ± 0.20 mmol g-1 and favorable mechanical properties (Young's moduli of 1.60-1.83 GPa). The membranes exhibited considerable dimensional stability (43.1-122.3% change in area and 42.1-61.5% change in thickness at 80 °C) and oxidative stability (~55.5%). The proton conductivity of the membranes, higher (174.3-301.8 mS cm-1) than that of Nafion 211 (123.8 mS cm-1), was the percent conducting volume corresponding to the water uptake. The membranes were observed to comprise isolated to tailed ionic clusters of size 15-45 nm and 3-8 nm, respectively, in transmission electron microscopy images. A fuel cell containing one such material exhibited high single-cell performance-a maximum power density of 1.32 W cm2 and current density of >1600 mA cm-2 at 0.6 V. The results indicate that the material is a candidate for proton exchange membranes in fuel cell applications.

9.
Polymers (Basel) ; 12(3)2020 Mar 08.
Article in English | MEDLINE | ID: mdl-32182689

ABSTRACT

Calcination reduction reaction is used to prepare Pt/EB (emeraldine base)-XC72 (Vulcan carbon black) composites as the cathode material of a proton exchange membrane fuel cell (PEMFC). The EB-XC72 core-shell composite obtained from directly polymerizing aniline on XC72 particles is able to chelate and capture the Pt-ions before calcination. X-ray diffraction spectra demonstrate Pt particles are successfully obtained on the EB-XC72 when the calcined temperature is higher than 600 °C. Micrographs of TEM and SEM illustrate the affluent, Pt nanoparticles are uniformly distributed on EB-XC72 at 800 °C (Pt/EB-XC72/800). More Pt is deposited on Pt/EB-XC72 composite as temperatures are higher than 600 °C. The Pt/EB-XC72/800 catalyst demonstrates typical type of a cyclic voltammograms (C-V) curve of a Pt-catalyst with clear Pt-H oxidation and Pt-O reduction peaks. The highest number of transferred electrons during ORR approaches 3.88 for Pt/EB-XC72/800. The maximum power density of the single cell based on Pt/EB-XC72/800 reaches 550 mW cm-2.

10.
Ann Intensive Care ; 9(1): 7, 2019 Jan 17.
Article in English | MEDLINE | ID: mdl-30656479

ABSTRACT

BACKGROUND: The study objective was to compare titration of positive end-expiratory pressure (PEEP) with electrical impedance tomography (EIT) and with ventilator-embedded pressure-volume loop in severe acute respiratory distress syndrome (ARDS). METHODS: We have designed a prospective study with historical control group. Twenty-four severe ARDS patients (arterial oxygen partial pressure to fractional inspired oxygen ratio, PaO2/FiO2 < 100 mmHg) were included in the EIT group and examined prospectively. Data from another 31 severe ARDS patients were evaluated retrospectively (control group). All patients were receiving medical care under identical general support guidelines and protective mechanical ventilation. The PEEP level selected in the EIT group was the intercept point of cumulated collapse and overdistension percentages curves. In the control group, optimal PEEP was selected 2 cmH2O above the lower inflection point on the static pressure-volume curve. RESULTS: Patients in the EIT group were younger (P < 0.05), and their mean plateau pressure was 1.5 cmH2O higher (P < 0.01). No differences in other baseline parameters such as APACHE II score, PaO2/FiO2, initial PEEP, driving pressure, tidal volume, and respiratory system compliance were found. Two hours after the first PEEP titration, significantly higher PEEP, compliance, and lower driving pressure were found in the EIT group (P < 0.01). Hospital survival rates were 66.7% (16 of 24 patients) in the EIT group and 48.4% (15 of 31) in the control group. Identical rates were found regarding the weaning success rate: 66.7% in the EIT group and 48.4% in the control group. CONCLUSION: In severe ARDS patients, it was feasible and safe to guide PEEP titration with EIT at the bedside. As compared with pressure-volume curve, the EIT-guided PEEP titration may be associated with improved oxygenation, compliance, driving pressure, and weaning success rate. The findings encourage further randomized control study with a larger sample size and potentially less bias in the baseline data. Trial Registration NCT03112512.

11.
J Nurs Res ; 25(4): 276-282, 2017 Aug.
Article in English | MEDLINE | ID: mdl-28683015

ABSTRACT

BACKGROUND: Clients with a spinal cord injury (SCI) must learn to manage their disabilities and may never be able to resume their previous lifestyle. Therefore, receiving relevant information and support from care practitioners and institutions is essential for clients with long-term SCI. PURPOSE: This study investigated the long-term homecare needs of clients with SCIs. METHODS: A qualitative approach was used in this study. Data were collected from March to May 2013. Four SCI associations were selected using purposive sampling, and four focus group interviews were conducted in Northern, Central, Southern, and Eastern Taiwan. Each focus group was composed of 7-12 participants. In-depth interviews (1.5-2.5 hours) were conducted. A content analysis method was adopted for data analysis. RESULTS: Thirty-eight participants took part in the study. The long-term care needs of clients with SCI require the following dynamic processes for rebuilding their lives: physical care and complication prevention, life planning, social support, discovery of the value of existence, and sexual satisfaction. CONCLUSIONS/IMPLICATIONS FOR PRACTICE: The results reveal the long-term care needs of clients with SCI. Nurses are expected to provide client-centered care, emphasize prevention rather than treatment of complications, initiate life planning at the early stages of a client's rehabilitation, enhance a client's social support, encourage a client's search for companionship and search for the value of existence and a life purpose, and be attentive to the sexual concerns of people with physical disabilities.


Subject(s)
Health Services Needs and Demand , Home Care Services , Spinal Cord Injuries/nursing , Female , Focus Groups , Humans , Long-Term Care , Male , Middle Aged , Taiwan
12.
West J Nurs Res ; 38(12): 1574-1594, 2016 12.
Article in English | MEDLINE | ID: mdl-27330046

ABSTRACT

Aging causes various changes in body composition, which are critical implications for health and physical functioning in aging adults. The aim of this study was to explore the body composition outcomes of a qigong intervention among community-dwelling aging adults. This was a quasi-experimental study in which 90 participants were recruited. Forty-eight participants (experimental group) attended a 30-min qigong program 3 times per week for 12 weeks, whereas 42 participants (control group) continued performing their usual daily activities. The experimental group achieved a greater reduction in the fat mass percentage at the posttest, and exhibited increased fat-free mass, lean body mass percentage, and lean body mass to fat mass ratio compared with the controls. No difference between the two groups in body mass index, fat mass, and lean body mass was observed. These results indicated that the qigong intervention showed beneficial outcomes of body composition among community-dwelling aging adults.


Subject(s)
Aging , Body Composition/physiology , Independent Living , Qigong/methods , Aged , Body Mass Index , Female , Humans , Male , Middle Aged , Treatment Outcome
13.
Hu Li Za Zhi ; 62(6): 13-9, 2015 Dec.
Article in Chinese | MEDLINE | ID: mdl-26645440

ABSTRACT

The health cultivation qigong exercise in traditional Chinese medicine refers to a traditional, integrated method of illness prevention and body strengthening, which promotes the functions of qi and the blood, smooths the meridians (energy channels), and balances the viscera and bowels through the regulation of the mind, the breathing, and the body. The concept of using qi to cultivate human life is part of the health cultivation practices of ancient Chinese codes and of Chinese medicine. This concept includes the principles, methods, essences, and clinical applications of the practice. In addition, traditional health cultivation references the concepts of yinyang, viscera and bowels, qi and blood, meridians, and essential energy spirit theory in order to explain the human biological phenomena, the theoretical and practical perspectives of qigong, and the basis of the treatment principle. The health cultivation qigong exercise of Chinese medicine utilizes the concept of the "unity of nature and human beings" in traditional Chinese thinking in its practice, which emphasizes the conformity to nature and seasons. In order to fully leverage the benefits from the purpose of health cultivation in qigong practice, the priority is to understand the health cultivation mechanism, the essentials/matters, and the precautions of qigong practices. Recently, the evidence regarding both the biological and the psychological benefits of qigong practices have been demonstrated in numbers of research articles. In particular, qigong is currently considered to be one of the best mild exercises that is suited to all age groups. Professional nurses are suggested to include the health cultivation qigong exercise as part of activities that target health improvement and illness prevention. Due to the diversity in qigong as practiced by different health cultivation qigong exercise sects, it is essential to accumulate more clinical evidence by conducting greater numbers of rigorous studies that may be referenced in evidence-based nursing practices.


Subject(s)
Medicine, Chinese Traditional , Qigong , Evidence-Based Nursing , Humans , Yin-Yang
15.
West J Nurs Res ; 37(11): 1383-403, 2015 Nov.
Article in English | MEDLINE | ID: mdl-24869492

ABSTRACT

Population aging is occurring worldwide, and preventing cardiovascular event in older people is a unique challenge. The aim of this study was to examine the effects of a 12-week qigong (eight-form moving meditation) training program on the heart rate variability and peripheral vasomotor response of middle-aged and elderly people in the community. This was a quasi-experimental study that included the pre-test, post-test, and nonequivalent control group designs. Seventy-seven participants (experimental group = 47; control group = 30) were recruited. The experimental group performed 30 min of eight-form moving meditation 3 times per week for 12 weeks, and the control group continued their normal daily activities. After 12 weeks, the interaction effects indicated that compared with the control group, the experimental group exhibited significantly improved heart rate variability and peripheral vasomotor responses.


Subject(s)
Heart Rate/physiology , Qigong , Vasomotor System/physiology , Aged , Female , Humans , Male , Middle Aged
16.
Complement Ther Med ; 22(3): 489-99, 2014 Jun.
Article in English | MEDLINE | ID: mdl-24906589

ABSTRACT

OBJECTIVE: In this study, we explored the differences in the use of complementary and alternative medicine (CAM) based on data from 2007 and 2011 national surveys in Taiwan. RESEARCH DESIGN: Two cross-sectional, community-based epidemiological surveys were conducted in Taiwan. Participants 18 years and older were interviewed regarding their CAM use in the previous 12 months. Nationally representative random-household telephone surveys using a sampling method with a probability proportional to size were conducted in 2007 and 2011. The data were analysed to compare the results between surveys. RESULTS: We obtained a total of 1260 and 2266 valid responses in 2007 and 2011, respectively. The use of at least one or more CAM therapies during the previous year decreased from 48.9% in 2007 to 37.8% in 2011 (p < .001). In both surveys, the most common CAM therapies used were Chinese medicinal herbs followed by health supplement products and tuina. We observed the greatest relative increase in CAM use between 2007 and 2011 in health supplement products (12.8% vs. 16.0%) and massage (1.3% vs. 2.9%), whereas the largest relative decrease occurred for tuina (24.4-13.4%) and Chinese medicinal herbs (31.6-25.4%). CONCLUSION: Widespread CAM use reflects a more personal orientation towards maintaining health and selecting health care support services. Thus, a set of standards should be established for the safety and effectiveness of therapies, and consensus building is required to overcome the differences among practitioners from various backgrounds and traditions.


Subject(s)
Complementary Therapies/statistics & numerical data , Adolescent , Adult , Cross-Sectional Studies , Female , Humans , Interviews as Topic , Male , Medicine, Chinese Traditional , Middle Aged , Taiwan/epidemiology , Young Adult
17.
Forsch Komplementmed ; 20(5): 345-52, 2013.
Article in English | MEDLINE | ID: mdl-24200824

ABSTRACT

BACKGROUND: In numerous countries worldwide, fall prevention among older adults is a major public health issue. For older adults, regular participation in moderate physical activity or exercise lowers the risks of falls. However, scant information is available regarding the prevention strategies that the most at-risk groups may undertake. The purpose of this study is to examine the effects of a fall prevention strategy, eight forms of moving meditation (EFMM), on community-dwelling middle-aged and older adults in Taiwan. METHODS: This was a quasi-experimental study; 84 participants were recruited from Taipei in Taiwan. For 12 weeks, participants in the experimental group performed 30-min EFMM 3 times per week. The measurements included a Functional Reach Test (FRT), Timed Get-up-and-Go Test (TGUG), and a One-Leg Stance Test (OLST) with eyes both opened and closed. All were conducted at the baseline and 12 weeks after intervention. RESULTS: The participants who performed EFMM showed a significant and positive performance on FRT, TGUG, and OLST with eyes opened and eyes closed compared to those in the control group. CONCLUSION: The results suggest that EFMM is an effective strategy for enhancing balance and functional mobility and preventing falls among community-dwelling middle-aged and older adults.


Subject(s)
Accidental Falls/prevention & control , Exercise Therapy/standards , Meditation , Aged , Female , Humans , Male , Middle Aged , Treatment Outcome
18.
Am J Health Promot ; 28(1): 16-22, 2013.
Article in English | MEDLINE | ID: mdl-23470186

ABSTRACT

PURPOSE: To examine the effects of a Tai Chi Chung (TCC) program, an efficiency approach, on anxiety and cardiovascular risk factors. DESIGN: A quasi-experimental study. SETTING: A community in Taipei City, Taiwan. Subjects. One hundred thirty-three adults aged 55 years and older. Intervention. Sixty-four participants (experimental group) attended a 60-minute Tai Chi exercise three times per week for 12 weeks, whereas 69 participants (control group) maintained their usual daily activities. MEASURES: Anxiety states, systolic blood pressure (SBP), diastolic blood pressure (DBP), body mass index (BMI), and waist circumference (WC) were assessed at baseline, 6 weeks into the experiment, and 12 weeks into the experiment. ANALYSIS: Generalized estimating equations were used to evaluate the changes. RESULTS: Participants showed a greater drop in anxiety levels (ß = -2.57, p = .001) and DBP (ß = -7.02, p < .001) at the 12-week follow-up than did the controls. SBP significantly decreased in the 6-week follow-up and 12-week follow-up tests. The participants in the intervention achieved a greater drop in BMI at the 6-week and 12-week follow-up visits than the controls. The interventions demonstrated decreased average WC at the 6-week and 12-week follow-up visits as compared to the controls. CONCLUSION: The results highlight the long-term benefits of a TCC program in facilitating health promotion by reducing anxiety and risk factors for cardiovascular diseases.


Subject(s)
Anxiety/prevention & control , Cardiovascular Diseases/prevention & control , Tai Ji , Aged , Body Mass Index , Case-Control Studies , Female , Health Status Indicators , Humans , Male , Middle Aged , Risk Factors , Risk Reduction Behavior , Taiwan
19.
Chempluschem ; 78(10): 1288-1295, 2013 Oct.
Article in English | MEDLINE | ID: mdl-31986779

ABSTRACT

We describe how the morphology, photoluminescence (PL), and electroluminescence properties of 2,2',7,7'-tetrakis(pyren-1-yl)-9,9'-spirobifluorene (TPSBF) are related to its film thickness and how, under optimized conditions, the three main PL emissions constitute a form of white light. We fabricated high-brightness, broad-spectrum, white-light organic light-emitting diodes, incorporating a single emission layer of the blue-light-emitting material TPSBF, which comprises four pyrene units linked to a spirobifluorene core. An organic light-emitting device with the configuration indium tin oxide (170 nm)/4,4',4''-tris[N-(2-naphthyl)-N-phenylamino]triphenylamine (15 nm)/4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (65 nm)/TPSBF (50 nm)/tris(8-hydroxyquinoline)aluminum (30 nm)/LiF (0.8 nm)/Al (200 nm) exhibited a broad-spectrum white emission with a maximum luminescence and current efficiency of 57 680 cd m-2 and 6.51 cd A-1 , respectively, and Commission International De l'Eclairage coordinates of (0.29,0.36).

20.
PLoS One ; 7(7): e40999, 2012.
Article in English | MEDLINE | ID: mdl-22848421

ABSTRACT

PKC plays a pivotal role in mediating monocyte adhesion; however, the underlying mechanisms of PKC-mediated cell adhesion are still unclear. In this study, we elucidated the signaling network of phorbol ester PMA-stimulated human monocyte adhesion. Our results with pharmacological inhibitors suggested the involvement of AMPK, Syk, Src and ERK in PKC-dependent adhesion of THP-1 monocytes to culture plates. Biochemical analysis further confirmed the ability of PMA to activate these kinases, as well as the involvement of AMPK-Syk-Src signaling in this event. Direct protein interaction between AMPK and Syk, which requires the kinase domain of AMPK and linker region of Syk, was observed following PMA stimulation. Notably, we identified Syk as a novel downstream target of AMPK; AICAR can induce Syk phosphorylation at Ser178 and activation of this kinase. However, activation of AMPK alone, either by stimulation with AICAR or by overexpression, is not sufficient to induce monocyte adhesion. Studies further demonstrated that PKC-mediated ERK signaling independent of AMPK activation is also involved in cell adhesion. Moreover, AMPK, Syk, Src and ERK signaling were also required for PMA to induce THP-1 cell adhesion to endothelial cells as well as to induce adhesion response of human primary monocytes. Taken together, we propose a bifurcated kinase signaling pathway involved in PMA-mediated adhesion of monocytes. PKC can activate LKB1/AMPK, leading to phosphorylation and activation of Syk, and subsequent activation of Src and FAK. In addition, PKC-dependent ERK activation induces a coordinated signal for cytoskeleton rearrangement and cell adhesion. For the first time we demonstrate Syk as a novel substrate target of AMPK, and shed new light on the role of AMPK in monocyte adhesion, in addition to its well identified functions in energy homeostasis.


Subject(s)
AMP-Activated Protein Kinases/metabolism , Intracellular Signaling Peptides and Proteins/metabolism , MAP Kinase Signaling System/physiology , Monocytes/enzymology , Protein Kinase C/metabolism , Protein-Tyrosine Kinases/metabolism , AMP-Activated Protein Kinase Kinases , Carcinogens/pharmacology , Cell Adhesion/drug effects , Cell Adhesion/physiology , Cell Line , Cytoskeleton/metabolism , Energy Metabolism/drug effects , Energy Metabolism/physiology , Enzyme Activation/drug effects , Enzyme Activation/physiology , Humans , MAP Kinase Signaling System/drug effects , Monocytes/cytology , Protein Serine-Threonine Kinases/metabolism , Syk Kinase , Tetradecanoylphorbol Acetate/pharmacology , src-Family Kinases/metabolism
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