Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 28
Filtrar
Más filtros

Bases de datos
Tipo del documento
Intervalo de año de publicación
1.
Nature ; 568(7751): 221-225, 2019 04.
Artículo en Inglés | MEDLINE | ID: mdl-30944480

RESUMEN

The global land and ocean carbon sinks have increased proportionally with increasing carbon dioxide emissions during the past decades1. It is thought that Northern Hemisphere lands make a dominant contribution to the global land carbon sink2-7; however, the long-term trend of the northern land sink remains uncertain. Here, using measurements of the interhemispheric gradient of atmospheric carbon dioxide from 1958 to 2016, we show that the northern land sink remained stable between the 1960s and the late 1980s, then increased by 0.5 ± 0.4 petagrams of carbon per year during the 1990s and by 0.6 ± 0.5 petagrams of carbon per year during the 2000s. The increase of the northern land sink in the 1990s accounts for 65% of the increase in the global land carbon flux during that period. The subsequent increase in the 2000s is larger than the increase in the global land carbon flux, suggesting a coincident decrease of carbon uptake in the Southern Hemisphere. Comparison of our findings with the simulations of an ensemble of terrestrial carbon models5,8 over the same period suggests that the decadal change in the northern land sink between the 1960s and the 1990s can be explained by a combination of increasing concentrations of atmospheric carbon dioxide, climate variability and changes in land cover. However, the increase during the 2000s is underestimated by all models, which suggests the need for improved consideration of changes in drivers such as nitrogen deposition, diffuse light and land-use change. Overall, our findings underscore the importance of Northern Hemispheric land as a carbon sink.


Asunto(s)
Dióxido de Carbono/análisis , Dióxido de Carbono/historia , Secuestro de Carbono , Mapeo Geográfico , Sedimentos Geológicos/química , Atmósfera/química , Carbono/química , Dióxido de Carbono/química , China , Materiales de Construcción/análisis , Bosques , Combustibles Fósiles/análisis , Historia del Siglo XX , Historia del Siglo XXI , Modelos Lineales , Modelos Teóricos , Nitrógeno/química , Siberia , Incertidumbre
2.
Nature ; 525(7568): 201-5, 2015 Sep 10.
Artículo en Inglés | MEDLINE | ID: mdl-26331545

RESUMEN

The global extent and distribution of forest trees is central to our understanding of the terrestrial biosphere. We provide the first spatially continuous map of forest tree density at a global scale. This map reveals that the global number of trees is approximately 3.04 trillion, an order of magnitude higher than the previous estimate. Of these trees, approximately 1.39 trillion exist in tropical and subtropical forests, with 0.74 trillion in boreal regions and 0.61 trillion in temperate regions. Biome-level trends in tree density demonstrate the importance of climate and topography in controlling local tree densities at finer scales, as well as the overwhelming effect of humans across most of the world. Based on our projected tree densities, we estimate that over 15 billion trees are cut down each year, and the global number of trees has fallen by approximately 46% since the start of human civilization.


Asunto(s)
Bosques , Mapeo Geográfico , Árboles/crecimiento & desarrollo , Ecología/estadística & datos numéricos , Ecosistema , Agricultura Forestal/estadística & datos numéricos , Densidad de Población , Reproducibilidad de los Resultados
3.
Zhonghua Fu Chan Ke Za Zhi ; 56(6): 425-433, 2021 Jun 25.
Artículo en Zh | MEDLINE | ID: mdl-34154318

RESUMEN

Objective: To investigate the differential expression of long non-coding RNA (lncRNA) in placental tissues of women with preeclampsia (PE) and the effect of MIR210HG on the biological function of HTR8/SVneo cells. Methods: A total of 39 cases of PE women (PE group) and 39 cases of normal pregnant women (CTL group) admitted to the Affiliated Hospital of Qingdao University from July 2018 to July 2019 were collected. (1) Transcriptome sequencing (RNA-seq) was used to analyze the differentially expressed lncRNAs in the placental tissues of the two groups. (2) The expression level of MIR210HG, one of the differentially expressed lncRNAs, in the placental tissues of the two groups was detected by real-time quantitative PCR. And the correlations between the expression level of MIR210HG and systolic blood pressure, diastolic blood pressure and neonatal birth weight were analyzed. (3) The constructed small interfering RNA and negative control (NC) RNA were transfected into the HTR8/SVneo cells. The cells were divided into MIR210HG knockdown (KD) group and NC group. The effects of living cell counting (CCK-8) and transwell assay on the proliferation and migration of HTR8/SVneo cells were detected. (4) RNA interacting with MIR210HG was predicted using the Encyclopedia of RNA Interactomes (ENCORI) database. Gene Ontology (GO) functional annotation, Kyoto Encyclopedia of Gene and Genomes (KEGG) and BioCarta pathway enrichment analysis were performed. Results: (1) A total of 26 significantly differentially expressed lncRNAs were found by RNA-seq, among which 21 lncRNAs were up-regulated and 5 lncRNAs were down-regulated. (2) The relative expression level of MIR210HG in the PE group was significantly higher than that in the CTL group (9.30±1.90 and 1.10±0.20, respectively; t=4.425, P<0.01). The relative expression level of MIR210HG had positive linear correlation with systolic blood pressure (r2=0.234, P<0.05) and diastolic blood pressure (r2=0.190, P<0.05), but had a negative linear correlation with newborn birth weight (r2=0.157, P<0.05). (3) Compared with the NC group, the proliferation and migration ability of HTR8/SVneo cells in the KD group were increased (all P<0.05). (4) A total of 38 RNAs that might interact with MIR210HG were predicted by ENCORI database. GO functional annotation analysis showed that MIR210HG might be involved in the functions of 27 pathways, including the regulation of production of molecular mediator of immune response, etc; KEGG pathway analysis showed that MIR210HG might be involved in the function of 8 pathways including allograft rejection, etc; Biocarta pathway analysis showed that MIR210HG may be involved in the functions of 8 pathways, including the eukaryotic initiation factor (eIF) pathway, etc. Conclusion: The expression of MIR210HG is up-regulated in the placental tissue of PE women, and MIR210HG might be a regulator of the biological behavior of trophoblast cells.


Asunto(s)
Placenta , Preeclampsia , ARN Largo no Codificante , Femenino , Humanos , Recién Nacido , Preeclampsia/genética , Embarazo , ARN Largo no Codificante/genética , ARN Interferente Pequeño , Trofoblastos
5.
Zhonghua Wai Ke Za Zhi ; 55(6): 410-415, 2017 Jun 01.
Artículo en Zh | MEDLINE | ID: mdl-28592072

RESUMEN

Objective: To investigate the methods and short-time clinical results of reconstruction of Paprosky type Ⅲ acetabulum bone defects by using tantalum augments. Methods: A total of 17 patients (17 hips) with Paprosky type Ⅲ acetabulum bone defects, treated with tantalum augments in revision of total hip arthroplasty at Department of Orthopedics Surgery in General Hospital of Chinese People's Liberation Army were retrospectively analyzed from March 2014 to May 2016.There were 6 males and 11 females aged from 23 to 74 years with an average of (50.2±16.3) years. Tantalum augments or TM-Cup augment (the cup-on-cup technique) were used to reconstruct the defects.The TM-Cup augment was the tantalum revision cup which was removed titanium ring. The cup-on-cup technique combined TM-Cup augment and biological acetabulum cup. Augments were served as the nonresorptive structural allograft in revision of total hip arthroplasty. Harris hip score was used to evaluate clinical effects. The vertical position of the rotation center was measured and analyzed. Radiographic assessments of the acetabular components were performed by DeLee-Charnley and the Anderson criteria and recorded postoperative complications. Results: All the patients were followed up from 3 to 29 months with an average of (16.2±5.4) months, tantalum augments and biological acetabulum cup were used in 13 patients, the TM-Cup augment and biological acetabulum cup were used in 4 patients. At the time of the latest follow-up, the mean Harris hip score increased compared to preoperatively (86.8±8.3 vs. 30.0±12.0) (t=12.78, P<0.01), the average vertical location of the center of rotation was decreased ((25.3±9.8) mm vs.(47.6±10.5)) mm (t=4.95, P<0.01). All the tantalum augments and biological acetabulum cups were stable, there were no infection, dislocation and other complications. Conclusions: The use of tantalum augments could be considered as an effective management of Paprosky type Ⅲ defects providing good clinical and radiographic outcomes in the short term.The cup-on-cup technique which was used in reconstruction of severe superior-invagination acetabular bone defects and restoration relatively normal center of rotation had special application value.


Asunto(s)
Acetábulo/cirugía , Artroplastia de Reemplazo de Cadera , Prótesis de Cadera , Adulto , Anciano , Femenino , Humanos , Luxaciones Articulares , Masculino , Metales , Persona de Mediana Edad , Complicaciones Posoperatorias , Falla de Prótesis , Reoperación , Estudios Retrospectivos , Rotación , Tantalio , Trasplante Homólogo
6.
Ecology ; 97(8): 1961-1969, 2016 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-27859198

RESUMEN

The timing of the fruit-set stage (i.e., start and end of fruit set) is crucial in a plant's life cycle, but its response to temperature change is still unclear. We investigated the timing of seven phenological events, including fruit-set dates during 3 yr for six alpine plants transplanted to warmer (approximately +3.5°C in soils) and cooler (approximately -3.5°C in soils) locations along an altitudinal gradient in the Tibetan area. We found that fruit-set dates remained relatively stable under both warming and cooling during the 3-yr transplant experiment. Three earlier phenological events (emergence of first leaf, first bud set, and first flowering) and two later phenological events (first leaf coloring and complete leaf coloring) were earlier by 4.8-8.2 d/°C and later by 3.2-7.1 d/°C in response to warming. Conversely, cooling delayed the three earlier events by 3.8-6.9 d/°C and advanced the two later events by 3.2-8.1 d/°C for all plant species. The timing of the first and/or last fruit-set dates, however, did not change significantly compared to earlier and later phenological events. Statistical analyses also showed that the dates of fruit set were not significantly correlated or had lower correlations with changes of soil temperature relative to the earlier and later phenological events. Alpine plants may thus acclimate to changes in temperature for their fruiting function by maintaining relatively stable timings of fruit set compared with other phenological events to maximize the success of seed maturation and dispersal in response to short-term warming or cooling.


Asunto(s)
Frutas , Temperatura , Cambio Climático , Frío , Ecología , Hojas de la Planta , Fenómenos Fisiológicos de las Plantas , Reproducción , Estaciones del Año
7.
Ecol Lett ; 15(6): 520-6, 2012 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-22472207

RESUMEN

Trees with sufficient nutrition are known to allocate carbon preferentially to aboveground plant parts. Our global study of 49 forests revealed an even more fundamental carbon allocation response to nutrient availability: forests with high-nutrient availability use 58 ± 3% (mean ± SE; 17 forests) of their photosynthates for plant biomass production (BP), while forests with low-nutrient availability only convert 42 ± 2% (mean ± SE; 19 forests) of annual photosynthates to biomass. This nutrient effect largely overshadows previously observed differences in carbon allocation patterns among climate zones, forest types and age classes. If forests with low-nutrient availability use 16 ± 4% less of their photosynthates for plant growth, what are these used for? Current knowledge suggests that lower BP per unit photosynthesis in forests with low- versus forests with high-nutrient availability reflects not merely an increase in plant respiration, but likely results from reduced carbon allocation to unaccounted components of net primary production, particularly root symbionts.


Asunto(s)
Biomasa , Ciclo del Carbono , Árboles/crecimiento & desarrollo , Procesos Autotróficos , Carbono/metabolismo , Respiración de la Célula , Clima , Agricultura Forestal , Fotosíntesis , Raíces de Plantas/microbiología , Árboles/metabolismo , Árboles/microbiología
8.
Nanotechnology ; 22(39): 395303, 2011 Sep 30.
Artículo en Inglés | MEDLINE | ID: mdl-21896974

RESUMEN

A large number of silicon (Si) patterns consisting of nanopillars of varying diameter and pitch have been fabricated and further coated with diamond-like carbon (DLC) and perfluoropolyether (Z-DOL) films. The wetting behavior and nano-adhesion/friction of the patterns are investigated experimentally in relation to the nanostructures and the hydrophobicity of the materials. Measurements of water contact angle illustrate that the patterning-enhanced wettability of the Si flat surface, along with two distinct wettings which are in good agreement with the Wenzel and hemi-wicking states, depended on the value of the pitch-over-diameter ratio. In the case of the coated patterns, three wetting states are observed: the Cassie-Baxter, the Wenzel, and a transition from the Cassie-Baxter into the Wenzel, which varies with regard to the hydrophobic properties of the DLC and Z-DOL. In terms of tribological properties, it is demonstrated that a combination of the nanopatterns and the films is effective in reducing adhesive and frictional forces. In addition, the pitch and diameter of the patterns are found to significantly influence their adhesion/friction behaviors.


Asunto(s)
Carbono/química , Éteres/química , Fluorocarburos/química , Nanoestructuras/química , Silicio/química , Humectabilidad , Nanoestructuras/ultraestructura
9.
J Adv Model Earth Syst ; 12(4): e2019MS001770, 2020 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-32714492

RESUMEN

In China, irrigation is widespread in 40.7% cropland to sustain crop yields. By its action on water cycle, irrigation affects water resources and local climate. In this study, a new irrigation module, including flood and paddy irrigation technologies, was developed in the ORCHIDEE-CROP land surface model which describes crop phenology and growth in order to estimate irrigation demands over China from 1982 to 2014. Three simulations were performed including NI (no irrigation), IR (with irrigation limited by local water resources), and FI (with irrigation demand fulfilled). Observations and census data were used to validate the simulations. Results showed that the estimated irrigation water withdrawal ( W ) based on IR and FI scenarios bracket statistical W with fair spatial agreements ( r = 0 . 68 ± 0 . 07 ; p < 0 . 01 ). Improving irrigation efficiency was found to be the dominant factor leading to the observed W decrease. By comparing simulated total water storage (TWS) with GRACE observations, we found that simulated TWS with irrigation well explained the TWS variation over China. However, our simulation overestimated the seasonality of TWS in the Yangtze River Basin due to ignoring regulation of artificial reservoirs. The observed TWS decrease in the Yellow River Basin caused by groundwater depletion was not totally captured in our simulation, but it can be inferred by combining simulated TWS with census data. Moreover, we demonstrated that land use change tended to drive W locally but had little effect on total W over China due to water resources limitation.

10.
Am J Transplant ; 9(9): 2024-33, 2009 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-19624561

RESUMEN

This study was performed to investigate the effect of sirolimus (SRL) on cyclosporine (CsA)-induced pancreatic islet dysfunction in rats. Three separate studies were performed. First, diabetogenic effect of SRL was evaluated with three different doses (0.15, 0.3 and 0.6 mg/kg). Second, rats were treated with SRL (0.3 mg/kg) with or without CsA (15 mg/kg) for 4 weeks. Third, rats were treated with CsA for 4 weeks, and then switched to SRL for 4 weeks. The effect of SRL on CsA-induced pancreatic islet dysfunction was evaluated by an intraperitoneal glucose tolerance test, plasma insulin concentration, HbA1c level, HOMA-R index, immunohistochemistry of insulin and pancreatic beta islet cell mass. The SRL treatment increased blood glucose concentration in a dose-dependent manner. The combined treatment with SRL and CsA increased blood glucose concentration, Hemoglobin A1c (HbA1c) level, HOMA-R [fasting insulin (mU/mL) x fasting glucose (mmol/L)]/22.5] index and decreased plasma insulin concentration, immunoreactivity of insulin and pancreatic beta islet cell mass compared with rats treated with CsA. CsA withdrawal for 4 weeks improved pancreatic beta-cell function and structure. However, conversion from CsA to SRL further increased blood glucose levels compared with the rats converted from vehicle to SRL. The results of our study demonstrate that SRL is diabetogenic and aggravates CsA-induced pancreatic islet dysfunction.


Asunto(s)
Ciclosporina/efectos adversos , Diabetes Mellitus Experimental/tratamiento farmacológico , Islotes Pancreáticos/efectos de los fármacos , Sirolimus/farmacología , 8-Hidroxi-2'-Desoxicoguanosina , Animales , Glucemia/metabolismo , Desoxiguanosina/análogos & derivados , Desoxiguanosina/farmacología , Diabetes Mellitus Experimental/patología , Relación Dosis-Respuesta a Droga , Hemoglobina Glucada/metabolismo , Inmunohistoquímica/métodos , Inmunosupresores/efectos adversos , Insulina/sangre , Masculino , Ratas , Ratas Sprague-Dawley
11.
Meat Sci ; 137: 258-264, 2018 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-29245028

RESUMEN

The fat quality is an important aspect, especially for Wagyu beef. A handheld fiber-optic near-infrared spectrometer for on-site evaluation of beef fat quality was developed, and the interactance spectra of the intermuscular fat from 833 Wagyu carcasses at 12 markets were measured. The calibration model was transferred to five slave instruments using twenty-six block samples. The performance of one slave instrument was verified at five meat markets (n=360). The coefficients of determination of the slave instrument for monounsaturated, oleic, and saturated fatty acid compositions determined by gas chromatography and near-infrared measurements were 0.69, 0.64, and 0.67, respectively. The standard error of prediction for the slave instrument was approximately 2%. The fiber-optic near-infrared spectrometers were highly accurate in the fat quality evaluation of Wagyu carcasses based on monounsaturated, oleic, and saturated fatty acid composition with easy calibration model transfer.


Asunto(s)
Tejido Adiposo/química , Bovinos , Ácidos Grasos/análisis , Carne Roja/análisis , Espectroscopía Infrarroja Corta/métodos , Animales , Cromatografía de Gases , Femenino , Masculino , Carne Roja/normas
12.
Sci Rep ; 7(1): 9632, 2017 08 29.
Artículo en Inglés | MEDLINE | ID: mdl-28851977

RESUMEN

Concentrations of atmospheric carbon dioxide (CO2) have continued to increase whereas atmospheric deposition of sulphur and nitrogen has declined in Europe and the USA during recent decades. Using time series of flux observations from 23 forests distributed throughout Europe and the USA, and generalised mixed models, we found that forest-level net ecosystem production and gross primary production have increased by 1% annually from 1995 to 2011. Statistical models indicated that increasing atmospheric CO2 was the most important factor driving the increasing strength of carbon sinks in these forests. We also found that the reduction of sulphur deposition in Europe and the USA lead to higher recovery in ecosystem respiration than in gross primary production, thus limiting the increase of carbon sequestration. By contrast, trends in climate and nitrogen deposition did not significantly contribute to changing carbon fluxes during the studied period. Our findings support the hypothesis of a general CO2-fertilization effect on vegetation growth and suggest that, so far unknown, sulphur deposition plays a significant role in the carbon balance of forests in industrialized regions. Our results show the need to include the effects of changing atmospheric composition, beyond CO2, to assess future dynamics of carbon-climate feedbacks not currently considered in earth system/climate modelling.

13.
Circ Res ; 89(6): E32-8, 2001 Sep 14.
Artículo en Inglés | MEDLINE | ID: mdl-11557745

RESUMEN

Atrial fibrillation (AF), the most common chronic arrhythmia, increases the risk of stroke and is an independent predictor of mortality. Available pharmacological treatments have limited efficacy. Once initiated, AF tends to self-perpetuate, owing in part to electrophysiological remodeling in the atria; however, the fundamental mechanisms underlying this process are still unclear. We have recently demonstrated that chronic human AF is associated with increased atrial oxidative stress and peroxynitrite formation; we have now tested the hypothesis that these events participate in both pacing-induced atrial electrophysiological remodeling and in the occurrence of AF following cardiac surgery. In chronically instrumented dogs, we found that rapid (400 min(-1)) atrial pacing was associated with attenuation of the atrial effective refractory period (ERP). Treatment with ascorbate, an antioxidant and peroxynitrite decomposition catalyst, did not directly modify the ERP, but attenuated the pacing-induced atrial ERP shortening following 24 to 48 hours of pacing. Biochemical studies revealed that pacing was associated with decreased tissue ascorbate levels and increased protein nitration (a biomarker of peroxynitrite formation). Oral ascorbate supplementation attenuated both of these changes. To evaluate the clinical significance of these observations, supplemental ascorbate was given to 43 patients before, and for 5 days following, cardiac bypass graft surgery. Patients receiving ascorbate had a 16.3% incidence of postoperative AF, compared with 34.9% in control subjects. In combination, these studies suggest that oxidative stress underlies early atrial electrophysiological remodeling and offer novel insight into the etiology and potential treatment of an enigmatic and difficult to control arrhythmia. The full text of this article is available at http://www.circresaha.org.


Asunto(s)
Antioxidantes/farmacología , Ácido Ascórbico/farmacología , Fibrilación Atrial/prevención & control , Nitratos/metabolismo , Tirosina/análogos & derivados , Anciano , Animales , Antioxidantes/uso terapéutico , Ácido Ascórbico/metabolismo , Ácido Ascórbico/uso terapéutico , Fibrilación Atrial/etiología , Fibrilación Atrial/fisiopatología , Estimulación Cardíaca Artificial/efectos adversos , Puente de Arteria Coronaria/efectos adversos , Perros , Electrofisiología , Femenino , Atrios Cardíacos/efectos de los fármacos , Atrios Cardíacos/metabolismo , Atrios Cardíacos/fisiopatología , Humanos , Masculino , Persona de Mediana Edad , Análisis Multivariante , Factores de Tiempo , Resultado del Tratamiento , Tirosina/metabolismo
14.
Phys Rev E ; 94(2-1): 020602, 2016 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-27627230

RESUMEN

Micron-sized colloidal spheres that are dispersed in an isotropic-nematic biphasic host suspension of charged rods (fd-virus particles) are shown to spontaneously form dimers, which exhibit a synchronized oscillatory motion. Dimer formation is not observed in the monophase of isotropic and nematic suspensions. The synchronized oscillations of dimers are connected to the inhomogeneous state of the host suspension of charged rods (fd viruses) where nematic domains are in coexistence with isotropic regions. The synchronization of oscillations occurs in bulk states, in the absence of an external field. With a low field strength of an applied electric field, the synchronization is rather reduced, but it recovers again when the field is turned off. In this Rapid Communication, we report this observation as an example of the strange attractor, occurring in the mixture of PS (polystyrene) dimers in an isotropic-nematic coexistence biphasic fd-virus network. Furthermore, we highlight that the synchronization of PS-dimer oscillations is the result of a global bifurcation diagram, driven by a delicate balance between the short-attractive "twisted" interaction of PS dimers and long-ranged electrostatic repulsive interactions of charged fd rods. The interest is then in the local enhancement of "twist-nematic" elasticity in reorientation of the dimer oscillations. An analysis of image-time correlations is provided with the data movies and Fourier transforms of averaged orientations for the synchronized oscillations of dimers in the biphasic I-N coexistence concentration of charged fd-virus suspensions.


Asunto(s)
Microesferas , Polímeros/química , Electricidad Estática , Movimiento (Física) , Poliestirenos/química , Suspensiones
16.
Toxicology ; 150(1-3): 179-89, 2000 Sep 07.
Artículo en Inglés | MEDLINE | ID: mdl-10996674

RESUMEN

We previously found that N,N-diethylaniline increased the frequency of sister chromatid exchange (SCE) of human lymphocytes to about five times that of the control value, and was as toxic as cyclophosphamide used as a positive control for SCE. To explore whether N,N-diethylaniline affects the function of lymphocytes, we evaluated its immunotoxicity using CBA/N mice. The mice were divided into four groups and received 0, 100, 200, or 400 mg/kg body weight of N,N-diethylaniline by subcutaneous injection. The following items were investigated on days 3 and 7 after injection: body weight, weight of spleen, number of splenocytes, natural killer (NK) and cytotoxic T lymphocyte (CTL) activities, and concanavalin A (Con A)- and lipopolysaccharide (LPS)-stimulated lymphocyte proliferation using splenocytes. The following splenocyte phenotypes were also quantified by flow cytometry: (1) B cells; (2) total T cells; (3) CD4(+) and CD8(+) T cells; (4) NK; (5) macrophages and (6) nucleated erythrocytes. The splenic NK and CTL activities in exposed groups significantly decreased compared to the control in a dose-dependent manner and lymphocytes from the 200 and 400 mg/kg groups showed significantly higher spontaneous proliferation. The weight of the spleen and number of splenocytes were significantly higher in exposed groups than in the control. N,N-Diethylaniline also increased the percentages of macrophages, nucleated erythrocytes and B cells in the spleen. On the other hand, N,N-diethylaniline did not affect LPS-stimulated B cell and Con A-stimulated T cell proliferation, or the percentages of NK, total T, and CD4(+) and CD8(+) T cells in the spleen or the body weight of mice. The above findings indicated that N,N-diethylaniline selectively inhibited splenic NK and CTL activity and this inhibition was due to decreased NK and CTL functions, but not due to changes in the numbers of splenic NK and T cells.


Asunto(s)
Compuestos de Anilina/toxicidad , Células Asesinas Naturales/efectos de los fármacos , Activación de Linfocitos/efectos de los fármacos , Bazo/efectos de los fármacos , Linfocitos T Citotóxicos/efectos de los fármacos , Animales , Peso Corporal/efectos de los fármacos , Inmunofenotipificación , Células Asesinas Naturales/inmunología , Masculino , Ratones , Ratones Endogámicos CBA , Tamaño de los Órganos/efectos de los fármacos , Intercambio de Cromátides Hermanas/efectos de los fármacos , Bazo/citología , Linfocitos T Citotóxicos/inmunología
17.
Toxicology ; 146(2-3): 209-20, 2000 May 05.
Artículo en Inglés | MEDLINE | ID: mdl-10814853

RESUMEN

More than 5000 passengers on Tokyo subway trains were injured by the nerve gas, sarin and its by-products. Analysis of phosphor-carrying metabolites of sarin and its by-products in urine samples from the victims suggested that they were exposed not only to sarin, but also by-products generated during sarin synthesis, i.e. diisopropyl methylphosphonate (DIMP) and diethyl methylphosphonate (DEMP). We suspected genetic after-effects due to sarin by-products, thus, we checked the frequency of sister chromatid exchange (SCE) and found that SCE was significantly higher in the victims than in a control group, and that DIMP and DEMP significantly induced human lymphocyte SCE in vitro. In the present study, to explore whether DIMP and DEMP, which induced a high frequency of SCE of lymphocytes, also affected the lymphocyte functions, we examined the effect of DIMP and DEMP on splenic natural killer (NK) and splenic cytotoxic T lymphocyte (CTL) activity in mice, and NK activity of human lymphocytes in vitro. We found that DIMP and DEMP significantly inhibited NK and CTL activity in a dose-dependent manner. The inhibition induced by DIMP was stronger than that by DEMP. The effect of DIMP and DEMP on the splenic NK activity of mice was stronger than on the splenic CTL activity, and the human lymphocytes is more sensitive to DIMP and DEMP than the splenocytes of mice.


Asunto(s)
Células Asesinas Naturales/efectos de los fármacos , Sarín/química , Sarín/toxicidad , Linfocitos T Citotóxicos/efectos de los fármacos , Violencia , Animales , Humanos , Técnicas In Vitro , Células Asesinas Naturales/inmunología , Masculino , Ratones , Ratones Endogámicos CBA , Compuestos Organofosforados/toxicidad , Intercambio de Cromátides Hermanas/efectos de los fármacos , Bazo/citología , Linfocitos T Citotóxicos/inmunología , Tokio
18.
Zhonghua Jie He He Hu Xi Za Zhi ; 15(4): 214-6, 254, 1992 Aug.
Artículo en Zh | MEDLINE | ID: mdl-1339159

RESUMEN

The levels of free radicals in the whole blood of the patients with cor pulmonale were determined using the method of electron spin resonance (ESR). The concentrations of serum SOD were determined using RIA. The concentrations of the MDA, vitamin E, selenium and the activities of the SeGSHPx, CAT of the patients were also measured using biochemical methods. The results showed that the level of free radical in the whole blood and serum MDA, SOD increase if compared with that of control group. The activities of SeGSH-Px, CAT and the concentration of vitamin E in serum of the patients are in lower level. These indicate that there is impairment in free radical metabolism of the patients.


Asunto(s)
Enfermedad Cardiopulmonar/metabolismo , Anciano , Catalasa/sangre , Espectroscopía de Resonancia por Spin del Electrón , Femenino , Radicales Libres , Glutatión Peroxidasa/sangre , Humanos , Peroxidación de Lípido , Masculino , Malondialdehído/sangre , Persona de Mediana Edad , Enfermedad Cardiopulmonar/enzimología , Superóxido Dismutasa/sangre
19.
Zhonghua Jie He He Hu Xi Za Zhi ; 21(8): 492-3, 1998 Aug.
Artículo en Zh | MEDLINE | ID: mdl-11360522

RESUMEN

OBJECTIVE: To study the effects of transcutaneous electrical stimulation during sleep on obstructive sleep apnea syndrom (OSAS). METHOD: Sixteen patients with OSAS were studied by polysomnography during all-night sleep with and without submental transcutaneous electrical stimulation (TES) of the genioglossus. RESULT: Fourteen of the 16 patients (87%) who accepted the TES were treated successfully (reduction of Al > 50%). The average apnea index showed a decrease of 29 events per hour when the TES were performed (P < 0.001). The average apnea time decreased from 22 to 7 sec (P < 0.001). The apnea time/TST decreased from 27% +/- 11% to 7% +/- 3%. The lowest SaO2 increased from 71% to 87% (P < 0.001). TES did not cause arousal. The sleep stages of SWS, and REM sleep effect (SE) increased significantly. CONCLUSION: TES is a conservative but effective treatment in patients with obstructive sleep apnea syndrome, although it failed to improve central sleep apnea.


Asunto(s)
Apnea Obstructiva del Sueño/terapia , Estimulación Eléctrica Transcutánea del Nervio , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Apnea Obstructiva del Sueño/fisiopatología , Fases del Sueño , Sueño REM
20.
Zhongguo Zhong Yao Za Zhi ; 20(1): 44-6, 63, 1995 Jan.
Artículo en Zh | MEDLINE | ID: mdl-7626212

RESUMEN

The methanolic extract Oenanthe stoloni fera iv, pretreatment can significantly prevent the arrhythmias induced by myocardial ischemia and reduce the myocardial infarct size in rats. It can also markedly prevent myocardial ischemia and reperfusion-induced arrhythmias. In addition, the methanolic extract of Oenanthe stoloni fera (100 mg/kg i.v.) helps significantly to decrease the MDA content and preserve the SOD activity in plasma.


Asunto(s)
Medicamentos Herbarios Chinos/farmacología , Depuradores de Radicales Libres , Isquemia Miocárdica/prevención & control , Daño por Reperfusión Miocárdica/prevención & control , Animales , Femenino , Masculino , Malondialdehído/sangre , Daño por Reperfusión Miocárdica/sangre , Ratas , Ratas Wistar , Superóxido Dismutasa/sangre
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA