Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Resultados 1 - 20 de 22
Filtrar
1.
BMC Pediatr ; 19(1): 454, 2019 11 22.
Artículo en Inglés | MEDLINE | ID: mdl-31752780

RESUMEN

BACKGROUND: The mental health and quality of life in children with asthma have attracted widespread attention. This study focused on the evaluation of mental health conditions and their clinical characteristics in Chinese children with asthma. METHODS: A total of 261 children with asthma aged 6 to 16 years old and 261 age- and gender-matched children from the general population were recruited to participate in this study from Guizhou Provincial People's Hospital. The parents of all subjects were interviewed using the MINI Kid and were required to finish a clinical characteristics questionnaire. Logistic regression analysis was performed to evaluate risk factors. RESULTS: The prevalence of mental health conditions in the asthma group was significantly higher than that in the control group (26.4% vs 14.6%, P < 0.001). A total of 10 mental health conditions was identified in the asthma group, the most common of which was ADHD (11.5%; 30/261), followed by oppositional defiant disorder (ODD) (10.7%; 28/261), separation anxiety disorder (6.1%; 16/261), social anxiety disorder (3.8%; 10/261), specific phobias (2.3%; 6/261), agoraphobia without panic (1.5%; 4/261), (mild) manic episodes (1.1%; 3/261), major depressive episodes (MDEs) (0.8%; 2/261), movement (tic) disorder (0.8%; 2/261), and dysthymia (0.4%; 1/261). A total of 6 neuropsychiatric conditions was detected in the control group, including ODD (5.7%; 15/261), ADHD (4.6%; 12/261), social anxiety disorder (3.1%; 8/261), seasonal anxiety disorder (SAD) (2.3%; 6/261), specific phobias (1.1%; 3/261), and agoraphobia without panic (0.4%; 1/261). The prevalence rates of ODD, ADHD, and SAD differed significantly between the two groups (P < 0.05). Multiple regression analysis revealed that severe persistent asthma (OR = 3.077, 95% CI 1.286-7.361), poor asthma control (OR = 2.005, 95% CI 1.111-3.619), and having asthma for > 3 years (OR = 2.948, 95% CI 1.580-5.502) were independent risk factors for the presence of mental health conditions in asthmatic children. CONCLUSIONS: Children with asthma have a higher rate of mental health conditions than non-asthmatic children. Standardized diagnosis and treatment may help reduce the risk of neuropsychiatric conditions.


Asunto(s)
Asma/complicaciones , Trastornos Mentales/complicaciones , Adolescente , Pueblo Asiatico , Niño , China/epidemiología , Estudios Transversales , Femenino , Humanos , Masculino , Trastornos Mentales/diagnóstico , Trastornos Mentales/epidemiología , Trastornos Mentales/etiología , Enfermedades del Sistema Nervioso/complicaciones , Prevalencia , Factores de Riesgo
2.
J Environ Manage ; 231: 504-514, 2019 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-30388648

RESUMEN

This study represents an approach to assess the hydrologic effectiveness of low impact development (LID) practices based on the expected runoff process with different objectives and land utilization. The proposed approach is to simulate runoff hydrograph rather than several indices (e.g., runoff initiation, peak flow, and runoff volume) to avoid the uncertainties under a certain rainfall scenario. A rainfall-runoff model of a residential district in China, constructed based on the stormwater management model (SWMM), is auto-calibrated (validated) based on 12 (25) observed rainfall and runoff events using model-independent parameter estimation (PEST). The priority sites and parameters for LID practices for different objectives are auto-calculated using PEST based on the calibrated model and different expected runoff processes. The expected runoff processes are simulated from the calibrated model with four impervious cover scenarios corresponding to 5-year, 2-h duration design storm. The study illustrates that (i) the proposed approach can auto-optimize runoff manage strategies based on LID practices and land; (ii) the design parameters of LID practices can be auto-calculated and that simulated runoff processes are in near perfect agreement with expected runoff processes; (iii) this approach can auto-optimize any specific parameters of the SWMM and LID practices without changing those determined parameters. Our simple, but quantitative, approach for identifying potential LID sites and design parameters based on land can better inform the hydrologic effectiveness of LID practices for managing runoff.


Asunto(s)
Lluvia , Movimientos del Agua , China , Hidrología , Modelos Teóricos
3.
Environ Sci Pollut Res Int ; 30(19): 54885-54898, 2023 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-36881239

RESUMEN

Accurate quantification of precipitation complexity is vital for assessing the impact of changing environments on precipitation processes and guiding precipitation forecasting. However, previous research mostly quantified precipitation complexity from different perspectives, resulting in differences in complexity results. In this study, the multifractal detrended fluctuation analysis (MF-DFA; derived from fractal), Lyapunov exponent (derived from Chao), and sample entropy (derived from entropy) were used for investigating the complexity of regional precipitation. Then, the integrated complexity index was established by using the intercriteria correlation (CRITIC) method and the simple linear weighting (SWA) method. Finally, the proposed method is applied to China's Jinsha River basin (JRB). The research indicates that (1) the discriminability of the integrated complexity index is higher than that of MF-DFA, Lyapunov exponent, and sample entropy, which can better distinguish the precipitation complexity in the Jinsha River basin; (2) the higher complexity of monthly precipitation was mainly concentrated in the southeast, and the lower complexity was mainly located in the northwest; moreover, the monthly precipitation complexity for the selected study area is the highest at 0.854 at Weixi station and the lowest at 0.152 at Batang station; (3) the superimposed effects of the southwest monsoon, terrain, and reservoir construction have become the main factors that influence the spatial variation of complexity for precipitation. This study provides a new idea for developing an integrated complexity index, and the results are of great significance for regional precipitation disaster prevention and water resources management.


Asunto(s)
Tormentas Ciclónicas , Desastres , Ríos , Fractales , China
4.
Environ Sci Pollut Res Int ; 30(16): 46489-46502, 2023 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-36719583

RESUMEN

Statistical analysis of streamflow and sediment is very important for integrated watershed management and the design of water infrastructure, especially in silt-rich rivers. Here, we propose a bivariate joint distribution framework based on nonparametric kernel density estimation (KDE) and a hybrid copula function to describe the complex streamflow-sediment dependent structure. In this framework, the non-parametric KDE is used to fit the marginal distribution function of streamflow and sediment variables, and then the hybrid copula function is constructed by using the linear combination of Clayton, Frank, and Gumbel copulas, and compared with five commonly used single copulas (Clayton, Frank, Gumbel, Gaussian, and t). We use the Jinsha River Basin (JRB) in the Yangtze River's (JR) upper reaches to verify the proposed method. The results show the following: (1) Compared with the gamma distribution (Gamma) and generalized extreme value (GEV) distribution of parameters, the marginal distribution function of streamflow and sediment variables can be effectively obtained based on nonparametric KDE. (2) Compared with the single copula, the hybrid copula function more fully reflects the complex dependent structure of streamflow and sediment variables. (3) Compared with the best single copula, the precision of return period based on hybrid copula can be increased by 7.41%. In addition, the synchronous probability of streamflow and sediment in JRB is 0.553, and the asynchronous probability of streamflow and sediment is 0.447. This study can not only improve the accuracy of streamflow and sediment statistical analysis in JRB, but also provide a useful framework for other bivariate joint probability analysis.


Asunto(s)
Ríos , Probabilidad , Ríos/química
5.
Sci Total Environ ; 903: 166151, 2023 Dec 10.
Artículo en Inglés | MEDLINE | ID: mdl-37562610

RESUMEN

Microplastics, plastic particles with a size smaller than 5 mm, are widely observed in the global environments and pose a growing threat as they accumulate and affect the environments in numerous ways. These particles can be transported from inland water to coast and disperse from surface water to deep sediments, especially the latter, while knowledge of the hidden microplastics in sediment layers is still lacking. Understanding the characteristics and behavior of microplastics in deep sediments from inland water to coast is crucial for estimating the present and future global plastic budget from land to seas. Herein, present knowledge of microplastic sedimentation from inland water to coast is reviewed, with a focus on the physical characteristics of microplastics and environmental factors that affect sedimentation. The abundance, shape, composition, and timeline of microplastics in sediment layers in rivers, floodplains, lakes, estuaries and coastal wetlands are presented. The abundance of microplastics in sediment layers varies across sites and may exhibit opposite trends along depth, and generally the proportion of relatively small microplastics increases with depth, while less is known about the vertical trends in the shape and composition of microplastics. Timeline of microplastics is generally linked to the sedimentation rate, which varies from millimeters to centimeters per year in the reviewed studies. The spatiotemporal characteristics of microplastic sedimentation depend on the settling and erosion of microplastics, which are determined by two aspects, microplastic characteristics and environmental factors. The former aspect includes size, shape and density influenced by aggregation and biofouling, and the latter includes dynamic forces, topographic features, bioturbation and human activities. The comprehensive review of these factors highlights the needs to further quantify the characteristics of microplastic sedimentation and explore the role of these factors in microplastic sedimentation on various spatiotemporal scales.

6.
Natl Sci Rev ; 10(8): nwad097, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-37389148

RESUMEN

Large-scale disasters can disproportionately impact different population groups, causing prominent disparity and inequality, especially for the vulnerable and marginalized. Here, we investigate the resilience of human mobility under the disturbance of the unprecedented '720' Zhengzhou flood in China in 2021 using records of 1.32 billion mobile phone signaling generated by 4.35 million people. We find that although pluvial floods can trigger mobility reductions, the overall structural dynamics of mobility networks remain relatively stable. We also find that the low levels of mobility resilience in female, adolescent and older adult groups are mainly due to their insufficient capabilities to maintain business-as-usual travel frequency during the flood. Most importantly, we reveal three types of counter-intuitive, yet widely existing, resilience patterns of human mobility (namely, 'reverse bathtub', 'ever-increasing' and 'ever-decreasing' patterns), and demonstrate a universal mechanism of disaster-avoidance response by further corroborating that those abnormal resilience patterns are not associated with people's gender or age. In view of the common association between travel behaviors and travelers' socio-demographic characteristics, our findings provide a caveat for scholars when disclosing disparities in human travel behaviors during flood-induced emergencies.

7.
Ann Transl Med ; 7(22): 616, 2019 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-31930017

RESUMEN

BACKGROUND: Bilinguals are people that can use two languages for oral communication. Many bilinguals have specific language-associated cortical regions. This study aimed to analyze the cortical positioning features of vocal, semantic, and graphemic task zones in unskilled late Chinese (first)-English (second) (ULCE) bilinguals using the blood-oxygen-level dependent functional magnetic resonance imaging (BOLD-fMRI) technique. METHODS: Twelve ULCE bilinguals were assigned Chinese-English (C-E) vocal, semantic, and graphemic tasks; SPM8 software was used to compare and investigate the brain activation maps towards different language tasks and to calculate their corresponding lateralization indexes (LIs). RESULTS: These three language tasks in simple Chinese could activate most traditional language zones, which all exhibited obvious left-deviated activation dominance. A simple English task could also activate most traditional language zones, but only the semantic task appeared to have obvious left-deviated lateralization. However, none of the three tasks displayed any specific language zones between Chinese and English on the group level. CONCLUSIONS: Vocal, semantic, and graphemic tasks can all activate multiple brain regions in the language network and reflect their respective cognitive processing characteristics. Bilingual processing in ULCE bilinguals has similar neural mechanisms, but the left-deviated lateralization is not obvious when performing English vocal and graphemic tasks.

8.
Clin Chim Acta ; 388(1-2): 89-94, 2008 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-17991430

RESUMEN

BACKGROUND: Previously, bis(alpha-furancarboxylato)oxovanadium(IV)(BFOV) exhibited potent hypoglycemic activity in diabetic animals. We evaluated the effects of BFOV on lipolysis in isolated rat adipocytes and lipid metabolism in fat-fed/streptozotocin (STZ)-induced diabetic rats, an animal model of type 2 diabetes. METHODS: Antilipolytic action of BFOV was investigated by observing free fatty acids (FFA) release in isolated rat adipocytes treated with epinephrine and forskolin. Diabetic rats were induced by high-fat feeding plus STZ injection (25 mg/kg, i.p.). The rats were randomly divided into non-diabetic, diabetic, diabetic-BFOV (0.02, 0.06 and 0.2 mmol/kg) and diabetic-vanadyl sulfate group. All substances were given intragastrically to rats for 4 weeks. The concentrations of blood glucose, serum lipid and leptin, as well as body weight and food intake were determined. RESULTS: FFA release from adipocytes treated with epinephrine was markedly inhibited by BFOV and vanadyl sulfate, with the IC(50) values of 0.30+/-0.20 and 0.46+/-0.26 mmol/l, respectively, but not by insulin. Whereas, the inhibition of vanadyl compounds on FFA release triggered by forskolin in adipocytes were not observed. BFOV dose-dependently reduced serum triglycerides and FFA concentrations when compared with untreated diabetic rats (P<0.05), while it did not influence cholesterol concentrations, similar to vanadyl sulfate. Serum leptin concentration was also decreased both in the BFOV- and vanadyl sulfate-treated diabetic group (P<0.05). Moreover, BFOV markedly reduced blood glucose concentration and food intake (P<0.05), but it did not change the body weight of diabetic rats. CONCLUSION: BFOV has an antilipolytic action in adipocytes mediated by catecholamines. This action was distinct from that of insulin and also not related to inhibiting the activity of adenylate cyclase. In vivo, BFOV could improve dyslipidemia and leptin sensitivity in fat-fed/STZ-diabetic rats.


Asunto(s)
Adipocitos/efectos de los fármacos , Adipocitos/metabolismo , Lipólisis/efectos de los fármacos , Compuestos Organometálicos/farmacología , Animales , Diabetes Mellitus Experimental/inducido químicamente , Diabetes Mellitus Experimental/metabolismo , Modelos Moleculares , Conformación Molecular , Compuestos Organometálicos/química , Ratas , Ratas Sprague-Dawley
9.
Environ Toxicol Pharmacol ; 62: 188-198, 2018 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-30064059

RESUMEN

This study aimed to explore the effects of postnatal low-concentration arsenic exposure on learning, social skills and frontal cortex neurogenesis in rats. Water-based arsenic exposure rat models were established on postnatal days 4-10 (P4-P10). The experimental animals were divided into four groups: the control group, a 15 µg/L As2O3 water group, a 30 µg/L As2O3 water group, and a 45 µg/L As2O3 water group. Cognitive function was examined with the Morris water maze, anxiety-like behavior with the open field test and light-dark box test, and social skills with a social interaction test. The frontal cortices of pups from each experimental group were sectioned at various time points after arsenic exposure. The morphologies and neurogenesis of the neurons in the frontal cortices were observed by hematoxylin-eosin staining, Nissl staining, and doublecortin (DCX) immunostaining. Significant positive correlations between arsenic concentration and deficits in learning and social skills were found, and the arsenic exposure groups showed significant increases in anxiety-like behavior compared with the control group (all Ps<0.05). Abnormal morphologic changes in the external granular layer and external pyramidal layer were positively correlated with the water arsenic concentration in the acute phase of arsenic exposure. However, at five weeks after arsenic exposure, the frontal cortex morphology was restored. Moreover, immunohistochemistry revealed that compared to the control group, the groups that were exposed to arsenic exhibited significantly higher levels of DCX expression in the external granular and external pyramidal layers (all Ps<0.001). Furthermore, the 30 µg/L and 45 µg/L arsenic exposure groups still showed some DCX expression at five weeks after exposure. In conclusion, postnatal low-concentration arsenic exposure impaired learning and social skills and increased anxiety-like behaviors, and abnormal frontal cortex neurogenesis may be the mechanism underlying these effects.


Asunto(s)
Ansiedad/inducido químicamente , Arsénico/toxicidad , Trastorno Autístico/inducido químicamente , Lóbulo Frontal/efectos de los fármacos , Neurogénesis/efectos de los fármacos , Efectos Tardíos de la Exposición Prenatal , Animales , Conducta Animal/efectos de los fármacos , Proteína Doblecortina , Femenino , Lóbulo Frontal/crecimiento & desarrollo , Intercambio Materno-Fetal , Aprendizaje por Laberinto/efectos de los fármacos , Memoria/efectos de los fármacos , Embarazo , Ratas Sprague-Dawley
10.
Eur J Pharmacol ; 572(2-3): 213-9, 2007 Oct 31.
Artículo en Inglés | MEDLINE | ID: mdl-17651728

RESUMEN

Bis(alpha-furancarboxylato)oxovanadium(IV) (BFOV) is a new orally active anti-diabetic organic vanadium complex. In the previous studies, we found that BFOV exhibited a glucose-lowering activity following oral administration to type 1-like diabetic mice induced by alloxan and rats induced by streptozotocin, and the mechanism was not related to enhancing the insulin synthesis and secretion. Since the enhancement of insulin sensitivity is involved in one of the mechanisms by which vanadium exerts its anti-diabetic effects, BFOV has been further tested on fat-fed/streptozotocin-treated rats, a type 2-like diabetic animal model, in the present study. The results showed that 4 weeks of BFOV treatment significantly improved hyperglycemia, glucose intolerance and hyperinsulinemia, as well as increased insulin sensitivity index in the fat-fed/streptozotocin-diabetic rats. Furthermore, BFOV efficiently activated glucokinase, increased hepatic glycogen content and suppressed phosphoenolpyruvate carboxykinase gene expression in the liver and kidney of the diabetic rats, which contributed to augmentation of hepatic glucose disposal and maintenance of blood glucose homeostasis. These findings suggested that BEOV had anti-diabetic and insulin-sensitizing effects in the diabetic rats, exhibiting the potential to be developed as a new therapeutic agent for the treatment of type 2 diabetes.


Asunto(s)
Diabetes Mellitus Experimental/tratamiento farmacológico , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Grasas de la Dieta/administración & dosificación , Glucosa/metabolismo , Hipoglucemiantes/uso terapéutico , Compuestos Organometálicos/uso terapéutico , Vanadio , Administración Oral , Animales , Glucemia/metabolismo , Diabetes Mellitus Experimental/etiología , Glucoquinasa/metabolismo , Hipoglucemiantes/administración & dosificación , Insulina/sangre , Riñón/enzimología , Riñón/metabolismo , Hígado/enzimología , Hígado/metabolismo , Glucógeno Hepático/metabolismo , Masculino , Compuestos Organometálicos/administración & dosificación , Proteínas Serina-Treonina Quinasas/biosíntesis , Proteínas Serina-Treonina Quinasas/genética , ARN Mensajero/biosíntesis , Ratas , Ratas Sprague-Dawley , Estreptozocina
11.
Sci Total Environ ; 553: 1-12, 2016 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-26897578

RESUMEN

Urban inundation is a serious challenge that increasingly confronts the residents of many cities, as well as policymakers. Hence, inundation evaluation is becoming increasingly important around the world. This comprehensive assessment involves numerous indices in urban catchments, but the high-dimensional and non-linear relationship between the indices and the risk presents an enormous challenge for accurate evaluation. Therefore, an approach is hereby proposed to qualitatively and quantitatively evaluate inundation risks in urban drainage systems based on a storm water management model, the projection pursuit method, the ordinary kriging method and the K-means clustering method. This approach is tested using a residential district in Guangzhou, China. Seven evaluation indices were selected and twenty rainfall-runoff events were used to calibrate and validate the parameters of the rainfall-runoff model. The inundation risks in the study area drainage system were evaluated under different rainfall scenarios. The following conclusions are reached. (1) The proposed approach, without subjective factors, can identify the main driving factors, i.e., inundation duration, largest water flow and total flood amount in this study area. (2) The inundation risk of each manhole can be qualitatively analyzed and quantitatively calculated. There are 1, 8, 11, 14, 21, and 21 manholes at risk under the return periods of 1-year, 5-years, 10-years, 20-years, 50-years and 100-years, respectively. (3) The areas of levels III, IV and V increase with increasing rainfall return period based on analyzing the inundation risks for a variety of characteristics. (4) The relationships between rainfall intensity and inundation-affected areas are revealed by a logarithmic model. This study proposes a novel and successful approach to assessing risk in urban drainage systems and provides guidance for improving urban drainage systems and inundation preparedness.

12.
Life Sci ; 76(10): 1111-21, 2005 Jan 21.
Artículo en Inglés | MEDLINE | ID: mdl-15620575

RESUMEN

Ginkgo biloba extract (GBE), a valuable natural product for cerebral and cardiovascular diseases, is mainly composed of two classes of constituents: terpene lactones (e.g., ginkgolide A and B, bilobalide) and flavone glycosides (e.g., quercetin and kaempferol). Its electrophysiological action in heart is yet unclear. In the present study, using whole-cell patch clamp technique, we investigated electrophysiological effects of GBE on cation channel currents in ventricular myocytes isolated from rat hearts. We found that GBE 0.01-0.1% inhibited significantly the sodium current (I(Na)), L-type calcium current (I(Ca)) and transient outward potassium current (IK(to)) in a concentration-dependent manner. Surprisingly, its main ingredients, ginkgolide A (GB A), ginkgolide B (GB B) and bilobalide (GB BA) at 0.1 mM did not exhibit any significant effect on these cation channel currents. These results suggested that GBE is a potent non-selective cation channel modulator in cardiaomyocytes. Other constituents (rather than GB A, GB B and GB BA) might be responsible for the observed inhibitory effects of GBE on cation channels.


Asunto(s)
Ginkgo biloba , Canales Iónicos/efectos de los fármacos , Miocitos Cardíacos/efectos de los fármacos , Extractos Vegetales/farmacología , Animales , Canales de Calcio Tipo L/efectos de los fármacos , Dimetilsulfóxido/farmacología , Ventrículos Cardíacos , Masculino , Miocitos Cardíacos/metabolismo , Canales de Potasio/efectos de los fármacos , Ratas , Ratas Sprague-Dawley , Canales de Sodio/efectos de los fármacos
13.
Yao Xue Xue Bao ; 40(6): 496-500, 2005 Jun.
Artículo en Zh | MEDLINE | ID: mdl-16144312

RESUMEN

AIM: To study the hypoglycemic effect of bis (alpha-furancarboxylato) oxovanadium (IV) (VO-FA) in normal rats and streptozotocin (STZ)-diabetic rats. METHODS: Rats were injected intraperitoneally STZ 50 mg.kg(-1) to induce diabetes. Blood glucose, glycohemoglobin, glycogen and serum insulin were observed after administering intragastrically VO-FA for four weeks. RESULTS: After 2 weeks administration, VO-FA reduced the blood glucose in STZ-rats (P < 0. 01) dose-dependently, and up to 4 weeks the blood glucose was normalized (below 11.1 mmol.L(-1)) in some of STZ-rats, whereas did not decrease in normal rats. After administration of VO-FA at the dosage of 56.8 and 113.6 mg.kg(-1), the serum insulin levels were lowered in normal rats and STZ-rats, respectively. Moreover, VO-FA reduced glycohemoglobin, improved the glucose tolerance, and increased the liver glycogen and muscle glycogen contents in STZ-rats in a dose-dependent manner (P < 0. 05, P < 0. 01), but not in normal rats. CONCLUSION: VO-FA could improve the glycometabolism in STZ-rats, but not in normal rats.


Asunto(s)
Glucemia/metabolismo , Diabetes Mellitus Experimental/sangre , Hipoglucemiantes/farmacología , Compuestos Organometálicos/farmacología , Animales , Diabetes Mellitus Experimental/metabolismo , Relación Dosis-Respuesta a Droga , Prueba de Tolerancia a la Glucosa , Hemoglobina Glucada/metabolismo , Hipoglucemiantes/administración & dosificación , Insulina/sangre , Glucógeno Hepático/metabolismo , Masculino , Compuestos Organometálicos/administración & dosificación , Distribución Aleatoria , Ratas , Ratas Sprague-Dawley , Vanadio/administración & dosificación , Vanadio/farmacología
14.
Brain Res ; 944(1-2): 205-9, 2002 Jul 19.
Artículo en Inglés | MEDLINE | ID: mdl-12106682

RESUMEN

Spiramine T, an atisine-type diterpene alkaloid isolated from the Chinese herbal medicine Spiraea japonica var. acuta (Rosaceae), was shown to have neuroprotective effects on cerebral ischemia-reperfusion injury. In this study, the effects of spiramine T on antioxidant enzymes and nitric oxide production were evaluated in gerbils subjected to global forebrain ischemia (10 min) and reperfusion (5 days). Spiramine T (1.0 and 2.0 mg kg(-1) i.p.) markedly reduced the content of lipid peroxide (LPO), increased the glutathione peroxidase (GSH-PX) activity, and inhibited the increase of nitric oxidase (NOS) activity and nitric oxide production in the cortex during ischemia-reperfusion in gerbils. These results suggested that the neuroprotective effects of spiramine T were related to modulation of endogenous antioxidant enzymatic activities and reduction of the formation of nitric oxide.


Asunto(s)
Antioxidantes/farmacología , Isquemia Encefálica/tratamiento farmacológico , Corteza Cerebral/efectos de los fármacos , Glutatión Peroxidasa/efectos de los fármacos , Compuestos Heterocíclicos de 4 o más Anillos/farmacología , Óxido Nítrico/biosíntesis , Daño por Reperfusión/tratamiento farmacológico , Animales , Isquemia Encefálica/enzimología , Isquemia Encefálica/fisiopatología , Catalasa/efectos de los fármacos , Catalasa/metabolismo , Corteza Cerebral/enzimología , Corteza Cerebral/fisiopatología , Medicamentos Herbarios Chinos/farmacología , Femenino , Depuradores de Radicales Libres/farmacología , Gerbillinae , Glutatión/metabolismo , Glutatión Peroxidasa/metabolismo , Peróxidos Lipídicos/metabolismo , Masculino , Malondialdehído/metabolismo , Neuronas/efectos de los fármacos , Neuronas/enzimología , Óxido Nítrico Sintasa/efectos de los fármacos , Óxido Nítrico Sintasa/metabolismo , Estrés Oxidativo/efectos de los fármacos , Estrés Oxidativo/fisiología , Daño por Reperfusión/enzimología , Daño por Reperfusión/fisiopatología , Superóxido Dismutasa/efectos de los fármacos , Superóxido Dismutasa/metabolismo
15.
Eur J Pharmacol ; 449(1-2): 23-8, 2002 Aug 02.
Artículo en Inglés | MEDLINE | ID: mdl-12163102

RESUMEN

Six diterpene alkaloids with an atisine-type C(20)-skeleton isolated from the Chinese herbal medicines Spiraea japonica var. acuta and S. japonica var. ovalifolia, as well as eight derivatives of spiramine C and spiradine F were evaluated for the ability to inhibit aggregation of rabbit platelets induced by arachidonic acid, ADP, and platelet-activating factor (PAF) in vitro. The results showed that 12 of the 14 atisine-type diterpene alkaloids significantly inhibited PAF-induced platelet aggregation in a concentration-dependent manner, but had no effect on ADP- or arachidonic acid-induced aggregation, exhibiting a selective inhibition. It is the first report that C(20)-diterpene alkaloids inhibit PAF-induced platelet aggregation. However, spiramine C1 concentration-dependently inhibited platelet aggregation induced by PAF, ADP and arachidonic acid with IC(50) values of 30.5+/-2.7, 56.8+/-8.4 and 29.9+/-9.9 microM, respectively, suggesting a non-selective antiplatelet aggregation action. The inhibitory effect of spiramine C1 on arachidonic acid was as potent as that of aspirin. Primary studies of the structure-activity relationships for inhibition of PAF-induced aggregation showed that the oxygen substitution at the C-15 position and the presence of an oxazolidine ring in spiramine alkaloids were essential to their antiplatelet aggregation effects. These results suggest that the atisine-type alkaloids isolated from S. japonica are a class of novel antiplatelet aggregation agents.


Asunto(s)
Alcaloides/farmacología , Plaquetas/efectos de los fármacos , Diterpenos/farmacología , Inhibidores de Agregación Plaquetaria/farmacología , Spiraea/química , Adenosina Difosfato/farmacología , Animales , Ácido Araquidónico/farmacología , Aspirina/farmacología , Femenino , Fibrinolíticos/farmacología , Ginkgólidos , Técnicas In Vitro , Indicadores y Reactivos , Lactonas/farmacología , Masculino , Extractos Vegetales/farmacología , Raíces de Plantas/química , Factor de Activación Plaquetaria/farmacología , Conejos
16.
Z Naturforsch C J Biosci ; 59(7-8): 481-4, 2004.
Artículo en Inglés | MEDLINE | ID: mdl-15813365

RESUMEN

In vitro antioxidant activities of three sweet dihydrochalcone glucosides from the leaves of Lithocarpus pachyphyllus (Kurz) Rehd. (Fagaceae), trilobatin 2"-acetate (1), phloridzin (2) and trilobatin (3), were investigated. The IC50 (50% inhibitory concentration) values for compounds 1-3 of lipid peroxidation in rat liver homogenate were 261, 28, 88 microM, respectively. Compounds 1-3 increased superoxide dismutase (SOD) activity with EC50 (50% effective concentration) values of 575, 167, 128 microM, and glutathione peroxidase (GSH-Px) activity with EC50 values of 717, 347, 129 microM, respectively, and showed only weak DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging activity.


Asunto(s)
Antioxidantes/aislamiento & purificación , Chalcona/análogos & derivados , Chalcona/química , Fagaceae/química , Depuradores de Radicales Libres/farmacología , Hojas de la Planta/química , Animales , Antioxidantes/farmacología , Compuestos de Bifenilo , Chalcona/aislamiento & purificación , Chalcona/farmacología , Chalconas , Depuradores de Radicales Libres/química , Depuradores de Radicales Libres/aislamiento & purificación , Glucósidos , Glutatión Peroxidasa/metabolismo , Hidrazinas , Peroxidación de Lípido/efectos de los fármacos , Hígado/efectos de los fármacos , Hígado/metabolismo , Picratos , Ratas , Superóxido Dismutasa/metabolismo
17.
Z Naturforsch C J Biosci ; 59(5-6): 359-62, 2004.
Artículo en Inglés | MEDLINE | ID: mdl-18998401

RESUMEN

The antioxidant activity in vitro of three poly(phenylacetyloxy)-substituted 1,1':4',1"-terphenyl compounds from the edible mushroom Thelephora ganbajun were investigated. The IC50 values of compounds 1-3 for lipid peroxidation in rat liver homogenate were 400, 48, 54 microM, respectively. Compounds 1-3 increased superoxide dismutase (SOD) activity with EC50 values of 182, 74, 204 microM. They were also assessed on the DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging activity with EC50 values of 49, 1233, 55 microM.


Asunto(s)
Antioxidantes/farmacología , Basidiomycota/química , Peroxidación de Lípido/efectos de los fármacos , Compuestos de Terfenilo/farmacología , Animales , Antioxidantes/aislamiento & purificación , Compuestos de Bifenilo/farmacología , China , Células HeLa/efectos de los fármacos , Humanos , Hidrazinas/farmacología , Células KB/efectos de los fármacos , Hígado/enzimología , Masculino , Picratos , Ratas , Ratas Sprague-Dawley , Superóxido Dismutasa/efectos de los fármacos , Superóxido Dismutasa/metabolismo , Compuestos de Terfenilo/aislamiento & purificación
18.
Zhong Xi Yi Jie He Xue Bao ; 2(2): 106-10, 122, 2004 Mar.
Artículo en Zh | MEDLINE | ID: mdl-15339469

RESUMEN

OBJECTIVE: To investigate the effects of PUW (a fraction containing 60% corilagin from a Chinese herbal plant Phyllanthus urinaria) on thrombosis and coagulation system. METHODS: Myers's method was used to evaluate the protection of intravenously administered PUW against the male mouse sudden death caused by injection of 75 mg/kg arachidonic acid in the tail vein; Charlton's method was modified to observe antithrombotic effect of PUW in rat electrically stimulated carotid artery thrombosis model; and the model of venous thrombosis was produced to investigate the antithrombotic effect of PUW. Rosette assay was used to observe the effect of PUW on platelet-neutrophil adhesion. The effects of PUW were monitored on euglobulin lysis time (ELT), prothrombin time (PT), kaolin partial thromboplastin time (KPTT), and bleeding time (BT) in rats, according to the methods of Kowalski, HUANG Zheng-Liang, and GU Yue-Fang, et al, respectively. RESULTS: The results showed that PUW administered intravenously significantly decreased the mouse mortality, prolonged the occlusion time of rat carotid arteries, and reduced the wet and dry thrombus weight of the inferior vena cava, respectively. PUW markedly inhibited the binding of activated platelets to neutrophils, obtaining 39.7 mg/L of the medium inhibitory concentration. Intravenously administered PUW significantly shortened ELT, prolonged KPTT while had no influence on PT; PUW increased BT in rat tail tips but the BT caused by PUW was much shorter than that by aspirin or urokinase. CONCLUSION: It is suggested that PUW has the potential of antithrombosis due to its inhibition of platelet-neutrophil adhesion. PUW shows the tendency to bleeding, however, it could not cause serious bleeding side effect as compared with aspirin or urokinase.


Asunto(s)
Coagulación Sanguínea/efectos de los fármacos , Phyllanthus/química , Trombosis/prevención & control , Animales , Femenino , Masculino , Ratones , Ratones Endogámicos ICR , Neutrófilos/efectos de los fármacos , Neutrófilos/fisiología , Adhesividad Plaquetaria/efectos de los fármacos , Embolia Pulmonar/prevención & control , Conejos , Ratas , Ratas Sprague-Dawley
19.
Zhongguo Shi Yan Xue Ye Xue Za Zhi ; 16(1): 170-4, 2008 Feb.
Artículo en Zh | MEDLINE | ID: mdl-18315924

RESUMEN

The aim of this study was to investigate the roles of chemokine CCL20 in development of CD4(+)CD25(+) thymocytes by means of fetal thymus organ culture. Fetal mouse thymus lobes were removed at the fetus age of 14.5 days and cultured in complete RPMI 1640 with 20% FBS in vitro. Phenotypes of the thymocytes were analyzed by FACS and the number of cells per lobe was counted. The results revealed that from day 14.5 to day 19, the absolute and relative numbers of the CD4(+)CD25(+) thymocytes varied similarly as their development as in vitro culture at 6 days. Data showed that during the 6 days in vitro culture the CD4(+)CD25(+) cell percentage out of CD4(+) cells was 58.29%, 12.14%, 6.08%, 17.78%, 9.06%, 4.04% and the CD4(+)CD25(+) cell percentage out of CD25(+) cells was 3.75%, 10.81%, 17.20%, 51.93%, 61.64%, 80.06%. All these data indicated similar characters to their development in vivo. Moreover, at interference with CCL20, the percentage of CD4(+)CD25(+) T cells in thymocytes significantly decreased at the 3 and 6 days from 3.24+/-0.18 and 3.96+/-0.24 to 1.27+/-0.11 (p<0.001) and 1.76+/-0.22 (p<0.001) respectively. It is concluded that the development of CD4(+)CD25(+) thymocytes is similar both in vitro and in vivo, interfering with CCL20 significantly downregulate the expression of CD4(+)CD25(+) T cells. The above data may help to understand the development of naturally arising CD4(+)CD25(+) regulatory T cells.


Asunto(s)
Quimiocina CCL20/farmacología , Linfocitos T Reguladores/citología , Linfocitos T Reguladores/efectos de los fármacos , Timo/citología , Timo/embriología , Animales , Embrión de Mamíferos , Desarrollo Embrionario , Femenino , Masculino , Ratones , Ratones Endogámicos BALB C , Técnicas de Cultivo de Órganos
20.
Planta Med ; 69(7): 605-9, 2003 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-12898414

RESUMEN

The effects of plumbagin were investigated on platelet aggregation in vitro and ex vivo, on the binding of thrombin-stimulated platelets to neutrophils, and platelet aggregation induced by intact neutrophils and N-formyl-methionyl-leucyl-phenylalanine (fMLP) or platelet activating factor (PAF) activated neutrophils, by use of the methods of Hamburger, McEver and Born, respectively. The results showed that plumbagin in vitro significantly inhibited adenosine diphosphate (ADP)-, arachidonic acid (AA)-, or platelet activating factor (PAF)-induced platelet aggregation, in a concentration-dependent manner. The medium inhibitory concentrations (IC 50 ) were 39.4, 82.7 and 38.1 microM, respectively. Intragastric plumbagin at 10 mg/kg markedly suppressed platelet aggregation induced by ADP, AA, or PAF. Plumbagin decreased the binding between thrombin-stimulated platelets and neutrophils with an IC 50 of 62.9 microM. Plumbagin significantly inhibited washed platelet aggregation stimulated by fMLP- or PAF-activated neutrophils. The IC 50 values were 54.3 and 47.6 microM, respectively. On the other hand, plumbagin and aspirin increased the inhibition of intact neutrophils on AA-induced platelet aggregation. It is suggested that plumbagin inhibited platelet aggregation in vitro and ex vivo, suppressed the binding of activated platelets to neutrophils, inhibited platelet aggregation induced by activated neutrophils, and increased inhibition of intact neutrophils on platelet reactivity. Abbreviations. DMSO:dimethyl sulphoxide fMLP: N-formyl-methionyl-leucyl-phenylalanine ADP:adenosine diphosphate AA:arachidonic acid PAF:platelet activating factor


Asunto(s)
Plaquetas/efectos de los fármacos , Naftoquinonas/farmacología , Neutrófilos/efectos de los fármacos , Agregación Plaquetaria/efectos de los fármacos , Adenosina Difosfato/farmacología , Animales , Ácido Araquidónico/farmacología , Técnicas In Vitro , Masculino , Factor de Activación Plaquetaria/farmacología , Conejos
SELECCIÓN DE REFERENCIAS
Detalles de la búsqueda