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1.
Phys Med Biol ; 68(1)2022 12 23.
Artículo en Inglés | MEDLINE | ID: mdl-36562587

RESUMEN

Demand for large area parallel plate ionization chamber (PPIC) or large area ionization chamber (LAIC) has risen in recent years due to several advantages of the large effective area in monitoring therapeutic radiation beams. PPICs are designed for the measurements of beam profile and dosimetry in radiation therapy quality assurance (QA) procedures.Objective. Heterogeneous responses over the large sensitive area pose an undeniable concern for the straightforward applications of PPICs in clinical dosimetry. Uniformity calibration for the detector response is thus essential for the accurate performance of each PPIC unit.Approach.A large area XY strip PPIC, characterized by a large effective area of 345.44 × 345.44 mm2and 256 readout channels, was investigated in this study. A new systematic uniformity calibration is developed to improve the lateral response of the PPIC over the measurements for both narrow beams and large square field beams. A 2D response map of the PPIC was obtained by a spot-scanning method using a compact x-ray tube (mini x-ray). The mini x-ray, providing stable radiation (uncertainty <0.1%), was moved with a step size of 20 mm in 2 dimensions across the entire PPIC surface to collect a complete spot scan. Different uniformity calibration methods were introduced for the measurement of the PPIC by adopting the information from the detector 2D response map.Main results.Deviation of the detector response, before calibration, was observed to reach about 7% for the testing PPIC unit which is much higher than the recommended uniformity response of 1% (IAEA TRS-398). The uniformity response of the PPIC improved significantly to less than 1% across the detector surface after calibration.Significance.The proposed methods enable the practical application of PPIC in routine clinical dosimetry and can be reliably adopted by any radiation facility to perform daily and monthly QA.


Asunto(s)
Radiometría , Calibración , Rayos X , Radiometría/métodos , Incertidumbre
2.
Lupus ; 28(5): 658-666, 2019 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-30971165

RESUMEN

Lupus nephritis (LN) is the leading cause of mortality in lupus patients. This study aimed to investigate the treatment outcome and renal histological risk factors of LN in a tertiary referral center. Between 2006 and 2017, a retrospective observational study enrolled 148 biopsy-proven LN patients. After propensity score matching, 75 cases were included for further analysis. The classification and scoring of LN were assessed according to the International Society of Nephrology/Renal Pathology Society. Treatment response was evaluated by daily urine protein and urinalysis at two years after commencing induction treatment and the development of end-stage renal disease (ESRD). In total, 50.7% patients achieved complete remission (CR) or partial remission (PR), while 49.3% patients were categorized as nonresponders. Therapeutic responses in terms of CR/PR rates were associated with Systemic Lupus Erythematosus Disease Activity Index scores (odds ratio (OR): 1.34, 95% confidence interval (CI): 1.12-1.60, p = 0.001). Moreover, higher baseline creatinine levels (hazard ratio (HR): 2.10, 95% CI: 1.29-3.40, p = 0.003), higher renal activity index (HR: 1.30, 95% CI: 1.07-1.58, p = 0.008) and chronicity index (HR: 1.40, 95% CI: 1.06-1.85, p = 0.017) predicted ESRD. Among pathological scores, cellular crescents (HR: 4.42, 95% CI: 1.01-19.38, p = 0.049) and fibrous crescents (HR: 5.93, 95% CI: 1.41-24.92, p = 0.015) were independent risk factors for ESRD. In conclusion, higher lupus activity was a good prognostic marker for renal remission. Renal histology was predictive of ESRD. Large-scale prospective studies are required to verify the efficacy of mycophenolate in combination with azathioprine or cyclosporine in LN patients.


Asunto(s)
Inmunosupresores/uso terapéutico , Fallo Renal Crónico/etiología , Riñón/patología , Nefritis Lúpica/tratamiento farmacológico , Adolescente , Adulto , Azatioprina/uso terapéutico , Ciclosporina/uso terapéutico , Quimioterapia Combinada , Femenino , Humanos , Estimación de Kaplan-Meier , Fallo Renal Crónico/patología , Nefritis Lúpica/complicaciones , Masculino , Persona de Mediana Edad , Análisis Multivariante , Ácido Micofenólico/uso terapéutico , Puntaje de Propensión , Inducción de Remisión , Estudios Retrospectivos , Factores de Riesgo , Taiwán , Resultado del Tratamiento , Adulto Joven
3.
Int J Cosmet Sci ; 36(5): 471-6, 2014 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-24888887

RESUMEN

OBJECTIVE: The objective of this study was to optimize ultrasound-assisted extraction of phenolic compounds from Phyllanthus emblica. METHODS: Extracts obtained by UAE were evaluated for their antioxidant activities. Extraction experiments were carried out with three factors and three levels namely extraction time (varying from 15 to 60 min), ethanol concentration (varying from 50 to 90%) and frequency (varying from 28 to 56 kHz). RESULTS: The results showed that the UAE optimal conditions of extracting total phenol components were as follows: 15 min of extraction time, 60°C of extraction temperature, 70% of ethanol concentration, 56 kHz of ultrasonic frequency and a 1: 50 solid to solvent ratio. Under optimal conditions, the leaching-out rate of phenolic compounds was up to 55.34 mg g(-1) , and the yield of crude extract of P. emblica was up to 56.82%. The results reveal that the yield of phenolic compounds of UAE (56.82%) is higher than that of conventional solvent extraction (16.78%). Furthermore, the antioxidant activities of ethanol extracts obtained by UAE were evaluated in terms of activities of DPPH (1,1'-diphenyl-2-2'-picrylhydrazyl) radical scavenging activity, total antioxidant activity, metal chelating activity, and reducing power. P. emblica extracts obtained by UAE showed high antioxidant activity (26.00, 50.11 and 115.91 µg mL(-1) of IC50 values for DPPH radicals, total antioxidant ability and chelating ability of ferrous ion). CONCLUSION: The result of this study showed that UAE was a suitable method for the extraction of total phenolic compounds. Moreover, the author's main finding in this work is the fact that phenolic compounds from P. emblica show excellent antioxidant activity in multi-test systems.


Asunto(s)
Antioxidantes/aislamiento & purificación , Fenoles/aislamiento & purificación , Phyllanthus emblica/química , Ultrasonido , Antioxidantes/farmacología , Evaluación Preclínica de Medicamentos , Fenoles/farmacología
4.
J Bone Joint Surg Br ; 93(9): 1201-9, 2011 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-21911531

RESUMEN

In this study of 41 patients, we used proteomic, Western blot and immunohistochemical analyses to show that several reactive oxygen species scavenging enzymes are expressed differentially in patients with primary osteoarthritis and those with non-loosening and aseptic loosening after total hip replacement (THR). The patients were grouped as A (n = 16, primary THR), B (n = 10, fixed THR but requiring revision for polyethylene wear) and C (n = 15, requiring revision due to aseptic loosening) to verify the involvement of the identified targets in aseptic loosening. When compared with Groups A and B, Group C patients exhibited significant up-regulation of transthyretin and superoxide dismutase 3, but down-regulation of glutathione peroxidase 2 in their hip synovial fluids. Also, higher levels of superoxide dismutase 2 and peroxiredoxin 2, but not superoxide dismutase 1, catalase and glutathione perioxidase 1, were consistently detected in the hip capsules of Group C patients. We propose that dysregulated reactive oxygen species-related enzymes may play an important role in the pathogenesis and progression of aseptic loosening after THR.


Asunto(s)
Artroplastia de Reemplazo de Cadera/efectos adversos , Depuradores de Radicales Libres/metabolismo , Osteoartritis de la Cadera/enzimología , Falla de Prótesis/efectos adversos , Especies Reactivas de Oxígeno/metabolismo , Líquido Sinovial/química , Anciano , Western Blotting , Regulación hacia Abajo , Enzimas/metabolismo , Femenino , Humanos , Masculino , Persona de Mediana Edad , Osteoartritis de la Cadera/cirugía , Proteómica , Regulación hacia Arriba
5.
Lupus ; 20(13): 1404-10, 2011 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-21946514

RESUMEN

The objective of this study is to evaluate the correlation between antinucleosome antibodies and renal pathological activity in patients with proliferative lupus nephritis (LN). We evaluated 36 patients with proliferative LN, 14 non-renal lupus patients and 10 healthy volunteers. Lupus activity was assessed using the British Isles Lupus Assessment Group 2004 (BILAG 2004) index, serum anti-double stranded DNA (anti-dsDNA) levels, serum complement levels and daily urinary protein levels. All 36 lupus nephritis patients received renal biopsy. Antinucleosome antibodies were detected by enzyme-linked immunosorbent assay (ELISA). Our results showed that levels of serum antinucleosome antibodies were significantly higher in LN patients (median 90.35 units/ml, interquartile range [IQR] 37.38-135.23) than in non-renal SLE patients (median 5.45 units/ml, IQR 2.6-28.93, p <0.05) and in healthy volunteers (median 3.35 units/ml, IQR 2.95-5.23, p <0.001). Serum levels of antinucleosome antibodies were positively correlated with BILAG index (Spearman's r = 0.645, p <0.001) and serum anti-dsDNA antibody levels (r(s) = 0.644, p <0.01), while serum levels of antinucleosome antibodies were negatively correlated with serum levels of C3 (r(s) = -0.400, p <0.01) and C4 (r(s) = -0.300, p <0.05). Serum levels of antinucleosome antibodies were positively correlated with the histological activity index of LN (r(s) = 0.368, p <0.05). However, there was no significant correlation between serum levels of antinucleosome antibodies and the histological chronicity index. In conclusion, the serum level of antinucleosome antibodies is a potential biomarker for early recognition of renal involvement and evaluation of disease activity in SLE. Our preliminary results suggested that serum levels of antinucleosome antibodies might be a potential biomarker in evaluating pathological activity of LN.


Asunto(s)
Anticuerpos Antinucleares/sangre , Anticuerpos Antinucleares/inmunología , Biomarcadores/sangre , Nefritis Lúpica/sangre , Nefritis Lúpica/inmunología , Nefritis Lúpica/patología , Nucleosomas/inmunología , Adulto , Anciano , Complemento C3/inmunología , Complemento C4/inmunología , Femenino , Humanos , Glomérulos Renales/inmunología , Glomérulos Renales/patología , Nefritis Lúpica/fisiopatología , Masculino , Persona de Mediana Edad , Proteinuria/metabolismo
6.
Int J Tuberc Lung Dis ; 15(2): 192-200, 2011 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-21219680

RESUMEN

SETTING: effective tuberculosis (TB) screening should be performed before anti-tumour necrosis factor alpha (TNF-α) treatment in rheumatoid arthritis (RA). The usefulness of the tuberculin skin test (TST) and QuantiFERON®-TB Gold (QFT-G) for detecting latent tuberculosis infection (LTBI) is limited. OBJECTIVE: we tested the diagnostic performance of interferon-gamma (IFN-γ) inducible protein 10 (IP-10) and IFN-γ for detecting LTBI in RA patients receiving anti-TNF-α treatment. DESIGN: IP-10 levels were determined by enzyme-linked immunosorbent assay in 56 RA patients and 18 active TB patients. TST was performed using the Mantoux method and QFT-G was performed by measuring IFN-γ levels in whole blood treated with TB-specific antigens. RESULTS: twenty-four (42.9%) TST-positive patients were defined as having LTBI. Significantly higher levels of baseline, early secretory antigenic target 6 (ESAT-6) and culture filtrate protein 10 (CFP-10) stimulated IP-10 were observed in active TB patients (median 209.9 pg/ml, 899.0 pg/ml and 880.2 pg/ml, respectively) and RA patients with LTBI (165.3 pg/ml, 904.4 pg/ml and 747.5 pg/ml, respectively), compared to those without LTBI (89.3 pg/ml, 579.4 pg/ml and 515.0 pg/ml, respectively). Baseline IP-10 has high sensitivity (83.3% and 100%) and medium specificity (67.9% and 59.6%), while ESAT-6-stimulated IP-10 has high sensitivity (87.5% and 100%) and specificity (85.7% and 71.2%) for detecting LTBI and TB. The performance of IP-10 is superior to IFN-γ for detecting LTBI (TST+) and active TB. CONCLUSION: IP-10 may be used for detecting LTBI and as a potential biomarker to identify active TB in RA patients receiving anti-TNF-α treatment.


Asunto(s)
Antirreumáticos/uso terapéutico , Artritis Reumatoide/tratamiento farmacológico , Quimiocina CXCL10/sangre , Tuberculosis Latente/diagnóstico , Mycobacterium tuberculosis/inmunología , Tuberculosis/diagnóstico , Factor de Necrosis Tumoral alfa/antagonistas & inhibidores , Adulto , Anciano , Antígenos Bacterianos/inmunología , Artritis Reumatoide/inmunología , Proteínas Bacterianas/inmunología , Biomarcadores/sangre , Ensayo de Inmunoadsorción Enzimática , Femenino , Humanos , Interferón gamma/sangre , Cinética , Tuberculosis Latente/inmunología , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Curva ROC , Juego de Reactivos para Diagnóstico , Sensibilidad y Especificidad , Taiwán , Prueba de Tuberculina , Tuberculosis/inmunología
7.
Poult Sci ; 88(2): 309-15, 2009 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-19151345

RESUMEN

Bacillus subtilis var. natto N21 (Bac; for greater proteolytic capacity) and Saccharomyces cerevisiae Y10 (Sac; for greater acidic capacity) were applied to produce a 2-stage combined fermentation feed. This study investigated whether the enhancement of Bac+Sac fermented feed on broiler growth performance was due to the probiotics per se or due to the fermentation process. Trial 1 included 1-d-old broiler chicks (n=144) randomly assigned to control, water added (same as in the fermentation feed, 23%), and Bac+Sac fermented feed (FBac+Sac) treatments with 4 replicates. Trial 2 included 21-d-old broiler chickens (n=12) assigned into control and FBac+Sac groups for a metabolic trial for nutrient availability. Trial 3 included 1-d-old male broiler chicks (n=216) randomly assigned into 6 treatments with 3 replicates. Treatments included a control, Sac fermented feed (FSac), FBac+Sac, Bac powder (PBac), Sac powder (PSac), and Bac+Sac powder (PBac+Sac). The results from trial 1 showed that FBac+Sac increased BW and feed intake (P<0.05) in 21- and 39-d-old chickens. The water-added group showed decreased BW, weight gain, and feed intake (P<0.05). Trial 2 showed that FBac+ Sac increased gross energy availability (P<0.05). Trial 3 showed that FBac+Sac increased 21- and 39-d-old BW and weight gain (P<0.05). Diets supplemented with probiotic powder or fermented with Sac did not improve broiler growth performance (P>0.05). The growth performance improvement of the FBac+Sac treatment was probably not due to the added water, probiotic powder inclusion, or through single-strain fermentation, but due to the 2-stage fermentation process using Bac and Sac strains.


Asunto(s)
Alimentación Animal/microbiología , Bacillus subtilis , Pollos/crecimiento & desarrollo , Dieta/veterinaria , Fermentación , Saccharomyces cerevisiae , Fenómenos Fisiológicos Nutricionales de los Animales , Animales , Pollos/metabolismo , Contenido Digestivo/química , Contenido Digestivo/microbiología , Intestinos/citología , Intestinos/enzimología , Masculino , Distribución Aleatoria
8.
Lupus ; 18(1): 29-37, 2009 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-19074166

RESUMEN

Accumulating evidence indicates that interleukin (IL)-18 has a central role in the pathogenesis of lupus nephritis (LN). Although two recent studies showed that IL-18 promoter gene polymorphisms might be associated with systemic lupus erythematosus (SLE), to our knowledge, there have not been any reports concerning their association with LN. The aim of our study was to investigate the association of IL-18 promoter polymorphisms with World Health Organization pathological classes and identify their functional correlations. Sequence-specific primer polymerase chain reaction and the restriction fragment length polymorphism method were used to analyse the genotypes of IL-18 promoter polymorphism at the position -607 in 101 unrelated patients with LN, 64 non-renal patients with SLE and 174 ethnically matched healthy controls. Serum IL-18 levels were determined using enzyme-linked immunosorbent assay during the active phase. Immunohistochemical analysis was performed for IL-18 expression on renal biopsies from 72 patients with LN. Our results showed that patients with non-renal SLE had significantly higher frequencies of SNP-607/AA when compared to patients with LN (37.5% vs 18.8%, P < 0.05). LN patients with the AA genotype had significantly lower levels of serum IL-18 than those with the CA or CC genotype (P < 0.01) and also had lower levels of glomerular IL-18 expression than those with the CC genotype (P < 0.05). Significantly, higher frequencies of the SNP-607/AA genotype were observed in LN patients with WHO class III than in those with class IV (34.6% vs 15.6%, P < 0.05). The SNP-607/AA genotype was not observed in patients with LN who progressed to end-stage renal failure that required haemodialysis or renal transplantation. In conclusion, the SNP-607/AA genotype that had lower IL-18 levels might be a genetically protective factor against renal involvement in Chinese patients with SLE and against development of severe nephritis in patients with LN.


Asunto(s)
Predisposición Genética a la Enfermedad , Interleucina-18/genética , Nefritis Lúpica/genética , Polimorfismo de Nucleótido Simple , Adolescente , Adulto , Pueblo Asiatico/genética , China/epidemiología , Progresión de la Enfermedad , Ensayo de Inmunoadsorción Enzimática , Femenino , Genotipo , Humanos , Inmunohistoquímica , Interleucina-18/sangre , Nefritis Lúpica/clasificación , Nefritis Lúpica/patología , Masculino , Persona de Mediana Edad , Reacción en Cadena de la Polimerasa , Polimorfismo de Longitud del Fragmento de Restricción , Índice de Severidad de la Enfermedad , Adulto Joven
9.
Lupus ; 16(3): 168-75, 2007.
Artículo en Inglés | MEDLINE | ID: mdl-17432101

RESUMEN

An association between Epstein-Barr virus (EBV) infection and systemic lupus erythematosus (SLE) has been suggested from previous serologic evidence. Since most adults in Taiwan are EBV-infected, seroepidemiologic studies based on standard assays for EBV are unlikely to dissociate SLE patients and control groups. We reexamine this question by using novel methodologies in which IgA anti-EBV-coded nuclear antigens-1 (EBNA-1) and IgG anti-EBV DNase antibodies were analysed by ELISA, and EBV viral loads were detected by real-time quantitative PCR for 93 adult SLE patients and 370 age-, sex- and living place-matched healthy controls in Taiwan. The specificities of antibodies for extractible nuclear antigens were determined by Western blot. Our results show that IgA anti-EBV EBNA1 antibodies were detectable in 31.2% SLE patients but only in 4.1% of controls (odds ratio [OR] = 10.72, 95% confidence interval [CI] = 5.19-22.35; P < 10(-7)), IgG anti-EBV DNase antibodies were detected in 53.8% SLE patients but only in 12.2% controls (OR = 8.40, 95% CI = 4.87-14.51; P < 10(-7)). EBV DNA was amplifiable from the sera of 41.9% SLE patients but from only 3.24% controls (P < 0.05). A significant association of IgG anti-EBV DNase antibodies with anti-Sm/RNP antibodies was observed (P < 0.005). The higher seroreactivity and higher copy numbers of EBV genome indicated association of EBV infection with SLE in Taiwan.


Asunto(s)
Pueblo Asiatico , Infecciones por Virus de Epstein-Barr/complicaciones , Lupus Eritematoso Sistémico/virología , Corticoesteroides/administración & dosificación , Corticoesteroides/uso terapéutico , Adulto , Anticuerpos Antivirales/sangre , Autoantígenos/inmunología , ADN Viral/sangre , Desoxirribonucleasas/inmunología , Relación Dosis-Respuesta a Droga , Antígenos Nucleares del Virus de Epstein-Barr/inmunología , Genoma Viral , Herpesvirus Humano 4/enzimología , Herpesvirus Humano 4/genética , Humanos , Inmunoglobulina A/sangre , Inmunoglobulina G/sangre , Lupus Eritematoso Sistémico/sangre , Lupus Eritematoso Sistémico/tratamiento farmacológico , Lupus Eritematoso Sistémico/inmunología , Persona de Mediana Edad , Ribonucleoproteínas Nucleares Pequeñas/inmunología , Taiwán , Carga Viral , Proteínas Nucleares snRNP
10.
Protein J ; 25(1): 33-43, 2006 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-16721659

RESUMEN

Benzene-1,3-di-N-n-octylcarbamate (1), benzene-1-hydroxyl-3-N-n-octylcarbamate (2), benzene-1,3-di-N-n-ocztylthiocarbamate (3), and benzene-1-hydroxyl-3-N-n-octylthiocarbamate (4) are synthesized from 1,3-benzene-diol and are characterized as the pseudo-substrate inhibitors of acetylcholinesterase, butyrylcholinesterase, cholesterol esterase, lipase, trypsin, and chymotrypsin. For these six enzyme inhibitions by 1-4, the pKi values are linearly correlated with their log ki values - Brønsted plots. Therefore, 1-4 inhibit these enzymes through a common mechanism. Moreover, both pKi and log ki values for the inhibitions by 1,3, and 4 are linearly correlated with both pKi and log ki values for the inhibitions by 2, respectively. Thus, the pKi values for the inhibitions by 2 are defined as the nucleophilicity constants of these enzymes (nenzyme). The log k2 values for the inhibitions by 1-4 are also linearly correlated with the nenzyme values. Therefore, the nucleophilicity for serine hydrolases and proteases toward 1-4 also applies the Swain-Scott correlations.


Asunto(s)
Hidrolasas/química , Serina Endopeptidasas/química , Animales , Carbamatos , Bovinos , Inhibidores de la Colinesterasa/síntesis química , Quimotripsina/antagonistas & inhibidores , Electrophorus , Caballos , Hidrolasas/fisiología , Lipasa/antagonistas & inhibidores , Serina Endopeptidasas/fisiología , Esterol Esterasa/antagonistas & inhibidores , Relación Estructura-Actividad , Porcinos , Tiocarbamatos , Inhibidores de Tripsina/síntesis química
11.
Toxicol Appl Pharmacol ; 214(3): 244-52, 2006 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-16480751

RESUMEN

Acrolein is a highly electrophilic alpha,beta-unsaturated aldehyde that is present in cigarette smoke. Heme oxygenase-1 (HO-1) is a cytoprotective enzyme activated by various such electrophilic compounds. In this study, the regulatory effects of acrolein upon the expression of HO-1 were investigated in endothelial cells (ECs). We demonstrate that acrolein induces the elevation of HO-1 protein levels, and subsequent enzyme activity, at non-cytotoxic concentrations. An additional alpha,beta-unsaturated aldehyde, cinnamaldehyde, was also found to increase HO-1 expression and have less cytotoxicity than acrolein. Moreover, acrolein-mediated HO-1 induction is abrogated in the presence of actinomycin D and cycloheximide. Nrf2 is a transcription factor involved in the induction of HO-1 through an antioxidant response element (ARE) in the promoter region of the HO-1 gene. We show that acrolein induces Nrf2 translocation and ARE-luciferase reporter activity. Acrolein was also found to induce the production of both superoxide and H2O2 at levels greater than 100 microM. However, with the exception of NAC, no antioxidant generated any effect upon acrolein-dependent HO-1 expression in ECs. Our present findings suggest that reactive oxygen species (ROS) may not be a major modulator for HO-1 induction. Using buthionine sulfoximine to deplete the intracellular GSH levels further enhanced the effects of acrolein. We also found that cellular GSH level was rapidly reduced after both 10 and 100 microM acrolein treatment. However, after 6 h of exposure to ECs, only 10 microM acrolein treatment increases GSH level. In addition, only the JNK inhibitor SP600125 and tyrosine kinase inhibitor genistein had any significant inhibitory impact upon the upregulation of HO-1 by acrolein. Pretreatment with a range of other PI3 kinase inhibitors, including wortmannin and LY294002, showed no effects. Hence, we show in our current experiments that a sublethal concentration of acrolein is in fact a novel HO-1 inducer, and we further identify the principal underlying mechanisms involved in this process.


Asunto(s)
Acroleína/toxicidad , Contaminantes Atmosféricos/toxicidad , Células Endoteliales , Hemo-Oxigenasa 1/biosíntesis , MAP Quinasa Quinasa 4/metabolismo , Acroleína/aislamiento & purificación , Animales , Western Blotting , Bovinos , Supervivencia Celular/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Células Endoteliales/efectos de los fármacos , Células Endoteliales/enzimología , Células Endoteliales/metabolismo , Activación Enzimática/efectos de los fármacos , Glutatión/metabolismo , Factor 2 Relacionado con NF-E2/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Contaminación por Humo de Tabaco/efectos adversos , Contaminación por Humo de Tabaco/análisis , Regulación hacia Arriba
12.
Life Sci ; 78(26): 3035-42, 2006 May 22.
Artículo en Inglés | MEDLINE | ID: mdl-16413037

RESUMEN

In this study, the effects of 15d-PGJ(2) were investigated in IL-6-activated endothelial cells (ECs). 15d-PGJ(2) was found to abrogate phosphorylation on tyr705 of STAT3 in IL-6-treated ECs, in a dose- and time-dependent manner, but did not inhibit serine phosphorylation of STAT3 and the upperstream JAK2 phosphorylation. Other PPAR activators, such as WY1643 or ciglitazone, had no effect upon IL-6-induced STAT3 phosphorylation. Additionally, neither orthovanadate nor l-NAME treatment reverses the inhibition of STAT3 phosphorylation by 15d-PGJ(2). Otherwise, the effect of 15d-PGJ(2) requires the alpha,beta-unsaturated carbonyl group in the cyclopentane ring. A 15d-PGJ(2) analog, 9,10-Dihydro-15d-PGJ(2), which lack alpha,beta-unsaturated carbonyl group showed no increase in ROS production and no effect in inhibition of IL-6-induced STAT3 phosphorylation. The electrophilic compound, acrolein, mimics the inhibition effect of 15d-PGJ(2). Among the antioxidants, only NAC and glutathione reversed the effects of 15d-PGJ(2). NAC, glutathione and DTT all reversed the inhibition of STAT3 phosphorylation when preincubated with 15d-PGJ(2). The inhibition of ICAM-1 gene expression by 15d-PGJ(2) was abrogated by NAC and glutathione in IL-6-treated ECs. Taken together, these results suggest that 15d-PGJ(2) inhibits IL-6-stimulated phosphorylation on tyr705 of STAT3 dependent on its own electrophilic reactivity in ECs.


Asunto(s)
Células Endoteliales/metabolismo , Factores Inmunológicos/farmacología , Interleucina-6/antagonistas & inhibidores , Prostaglandina D2/análogos & derivados , Factor de Transcripción STAT3/metabolismo , Animales , Antioxidantes/farmacología , Northern Blotting , Western Blotting , Bovinos , Células Cultivadas , Disulfuros/metabolismo , Células Endoteliales/efectos de los fármacos , Molécula 1 de Adhesión Intercelular/farmacología , Mediciones Luminiscentes , Óxido Nítrico/fisiología , Oxidación-Reducción , Receptores Activados del Proliferador del Peroxisoma/fisiología , Fosforilación , Prostaglandina D2/farmacología , Proteínas Tirosina Fosfatasas/metabolismo , ARN/biosíntesis , ARN/aislamiento & purificación , Transducción de Señal/efectos de los fármacos , Compuestos de Sulfhidrilo/metabolismo , Tirosina/metabolismo
13.
Life Sci ; 78(25): 2889-97, 2006 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-16378625

RESUMEN

Heme oxygenase-1 (HO-1) is a cytoprotective enzyme activated by various phytochemicals and we examined the ability of Epigallocatechin-3-gallate (EGCG), the major constituent of green tea, to upregulate HO-1 expression in endothelial cells (ECs). We demonstrate that EGCG induces HO-1 expression in a concentration- and time-dependent manner. Furthermore, EGCG-mediated HO-1 induction was abrogated in the presence of actinomycin D and cycloheximide, indicating that this upregulation of HO-1 occurred at the transcriptional level. EGCG also upregulates Nrf2 levels in nuclear extracts and increases ARE-luciferase activity. Furthermore, EGCG is the most potent inducer of HO-1 expression of the different green tea constituents that we analyzed, but had no detectable cytotoxic effects over the 25-100 microM dosage range. The inhibition of intracellular ROS production by N-acetylcysteine (NAC), glutathione (GSH), superoxide dismutase (SOD), catalase and the mitochondrial complex I inhibitor, rotenone, results in a decrease in EGCG-dependent HO-1 expression. In addition, we determined that tyrosine kinase is involved in EGCG induction of HO-1 as this is abrogated by genistein. ECs treated with EGCG exhibit activation of Akt and ERK1/2. In addition, pharmacological inhibitors of phosphatidylinositol 3-kinase and MEK1/2, which are upstream of Akt and ERK1/2, respectively, attenuate EGCG-induced HO-1 expression. On the other hand, pretreatment of these cells with EGCG exerts significant cytoprotective effects against H2O2, suggesting that the induction of HO-1 is an important component in the protection against oxidative stress. Hence, EGCG is a novel phytochemical inducer of HO-1 expression and we further identify the principal underlying mechanisms involved in this process.


Asunto(s)
Antioxidantes/farmacología , Catequina/análogos & derivados , Quinasas MAP Reguladas por Señal Extracelular/fisiología , Hemo-Oxigenasa 1/biosíntesis , Fosfatidilinositol 3-Quinasas/fisiología , Transducción de Señal/efectos de los fármacos , Animales , Catequina/farmacología , Bovinos , Supervivencia Celular/efectos de los fármacos , Células Cultivadas , Relación Dosis-Respuesta a Droga , Células Endoteliales/efectos de los fármacos , Células Endoteliales/enzimología , Células Endoteliales/metabolismo , Inhibidores Enzimáticos/farmacología , Quinasas MAP Reguladas por Señal Extracelular/antagonistas & inhibidores , Estrés Oxidativo/efectos de los fármacos , Inhibidores de las Quinasa Fosfoinosítidos-3 , Regulación hacia Arriba
14.
Life Sci ; 78(4): 389-97, 2005 Dec 12.
Artículo en Inglés | MEDLINE | ID: mdl-16150460

RESUMEN

Resveratrol, a polyphenolic phytoaxelin present in red wine, has been suggested to protect against atherosclerosis and cardiovascular disease because of its antioxidant effects. Intercellular adhesion molecule (ICAM-1), induced by cytokines, has been hypothesized to play a role in the early events during atherosclerosis. In this study we tested the effects of resveratrol upon both IL-6-induced ICAM-1 gene expression and its underlying signaling pathways in endothelial cells (ECs). Resveratrol was found to inhibit both TNFalpha- and IL-6-induced ICAM-1 gene expression at the promoter, transcriptional and protein levels. Resveratrol also abrogates the tyr705 phosphorylation of STAT3 in IL-6-treated ECs, in a dose- and time-dependent manner. Although quercetin had similar effects, resveratrol showed higher inhibitory properties following 2-4 h pretreatments. Resveratrol has been shown to induce the activity of endothelial nitric oxide synthase (eNOS) and increase NO production. Consistent with this, the treatment of ECs with a NO donor (SNAP) reduces IL-6-induced STAT3 phosphorylation. Conversely, exposure of ECs to a NOS inhibitor reversed the effects of resveratrol upon IL-6-induced STAT3 phosphorylation. Furthermore, ECs transfected with constitutively active Rac1 (RacV12) showed increases in ICAM-1 promoter activity, intracellular reactive oxygen species (ROS) levels and STAT3 phosphorylation, and these increases were attenuated by resveratrol treatment. In summary, we demonstrate for the first time that resveratrol inhibits IL-6-induced ICAM-1 gene expression, in part, by interfering with Rac-mediated pathways via the attenuation of STAT3 phosphorylation. This study therefore provides important new insights that may contribute to the proposed beneficial effects of resveratrol in endothelial responses to cytokines during inflammation.


Asunto(s)
Antioxidantes/farmacología , Endotelio Vascular/efectos de los fármacos , Expresión Génica/efectos de los fármacos , Molécula 1 de Adhesión Intercelular/genética , Interleucina-6/farmacología , Factor de Transcripción STAT3/antagonistas & inhibidores , Estilbenos/farmacología , Animales , Bovinos , Células Cultivadas , Relación Dosis-Respuesta a Droga , Antagonismo de Drogas , Endotelio Vascular/metabolismo , Molécula 1 de Adhesión Intercelular/metabolismo , Óxido Nítrico/metabolismo , Óxido Nítrico Sintasa de Tipo III/antagonistas & inhibidores , Óxido Nítrico Sintasa de Tipo III/biosíntesis , Fosforilación , Quercetina/farmacología , Resveratrol , S-Nitroso-N-Acetilpenicilamina/farmacología , Factor de Transcripción STAT3/metabolismo , Transfección , Factor de Necrosis Tumoral alfa/farmacología , Proteína de Unión al GTP rac1/genética , Proteína de Unión al GTP rac1/metabolismo
15.
J Med Eng Technol ; 27(2): 77-84, 2003.
Artículo en Inglés | MEDLINE | ID: mdl-12745915

RESUMEN

During the last decade, progressive achievements in haemodynamics have shown that radial artery pulse pressure can be used to estimate the vascular properties of the internal organs. Clinical experiments have shown that slow and regular respiration has a large effect on the heart rate variability (HRV). This phenomenon is called respiratory sinus arrhythmia (RSA). It is known that respiration-related oscillations in venous return cause oscillations in stroke volume and blood pressure. It also can be inferred from cardiac output that systemic blood pressure has a similar respiration-related cycle. Moreover we found that the fluctuations of harmonics of arterial pulse are consistent with the fluctuation of HRV. This means that the whole cardiovascular system (CVS) makes rapid adaptation during respiration, and the harmonic proportions of arterial pulse were modified during different breath rates. This result shows that the regular respiration also has a large effect upon Windkessel properties of CVS.


Asunto(s)
Pulso Arterial , Respiración , Adulto , Presión Sanguínea , Frecuencia Cardíaca , Humanos , Masculino , Arteria Radial
16.
Zhonghua Yi Xue Za Zhi (Taipei) ; 64(4): 203-8, 2001 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-11458757

RESUMEN

BACKGROUND: Bone age (BA) estimation is one of the important applications of hand radiography in the area of pediatrics, especially for the diagnosis of endocrinological problems and growth disorders. BA estimation (BAE) is tedious, time-consuming and highly dependent upon the expert experience. Nowadays, most BAE standards are based on American standards, but there is no BAE standard for Taiwanese people. We attempt to construct a computerized BAE system to automate BAE and in the long run to build a BAE standard for Taiwanese. METHODS: Our BAE system is based on the carpal bone information. We propose a new 2-stage edge detection method for carpal bone feature extraction and a new method for locating the carpal bone region of interest. RESULTS: After the image is manually equalized, our BAE system can estimate the bone age automatically. The extracted carpal bone features were applied to three classifiers for age estimation: the weighted minimum distance, Bayes, and neural network classifiers. The Bayes and neural network classifiers had better results. In the 0.5-year tolerance case, they both had over 90% correct rate for both male and female training data. In the 1-year tolerance case, they could classify correctly for the male and female testing data. CONCLUSIONS: A computerized BAE system has been developed and some experiments have been conducted. It is found that the classifying results for 0.5-year tolerance are good and satisfactory.


Asunto(s)
Determinación de la Edad por el Esqueleto , Huesos del Carpo/diagnóstico por imagen , Femenino , Humanos , Masculino
17.
Appl Opt ; 37(32): 7496-503, 1998 Nov 10.
Artículo en Inglés | MEDLINE | ID: mdl-18301584

RESUMEN

A spatial Fourier transform approach is used to study the phenomena of polarization changing and beam profile deformation of light during the Raman-Nath, acousto-optic interaction in isotropic media. Starting from the vector version of the well-known Raman-Nath interaction equation and using a spatial Fourier transform allows analytic solutions that encompass the effects of polarization changing and beam-profile deformation for the multiple scattered light to be found in the spatial-frequency domain. Two kinds of sound wave, longitudinal and shear, are assumed to be interacted with the light, whose transverse spatial profile and state of polarization are arbitrary. It is shown that, for light with an arbitrary spatial profile after interaction with the sound wave in the Raman-Nath regime, the spatial profiles of the scattered light are almost the same shape as those of the input light. For the polarization changing part, it is found that the state of polarization and the direction of rotation can alter, depending not only on the sound amplitude but also on the propagation mode of the sound wave. Simulation results are provided to confirm the validity of this approach.

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