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1.
Sci Data ; 11(1): 425, 2024 Apr 24.
Artículo en Inglés | MEDLINE | ID: mdl-38658632

RESUMEN

Near-surface atmospheric moisture is a key environmental and hydro-climatic variable that has significant implications for the natural and human systems. However, high-resolution moisture data are severely lacking for fine-scale studies. Here, we develop the first 1 km high spatial resolution dataset of monthly moisture index collection in China (HiMIC-Monthly) over a long period of 2003~2020. HiMIC-Monthly is generated by the light gradient boosting machine algorithm (LightGBM) based on observations at 2,419 weather stations and multiple covariates, including land surface temperature, vapor pressure, land cover, impervious surface proportion, population density, and topography. This collection includes six commonly used moisture indices, enabling fine-scale assessment of moisture conditions from different perspectives. Results show that the HiMIC-Monthly dataset has a good performance, with R2 values for all six moisture indices exceeding 0.96 and root mean square error and mean absolute error values within a reasonable range. The dataset exhibits high consistency with in situ observations over various spatial and temporal regimes, demonstrating broad applicability and strong reliability.

2.
Sci Data ; 10(1): 634, 2023 09 18.
Artículo en Inglés | MEDLINE | ID: mdl-37723201

RESUMEN

Human-perceived temperature (HPT) describes the joint effects of multiple climatic factors such as temperature and humidity. Extreme HPT events may reduce labor capacity and cause thermal discomfort and even mortality. These events are becoming more frequent and more intense under global warming, posing severe threats to human and natural systems worldwide, particularly in populated areas with intensive human activities, e.g., the North China Plain (NCP). Therefore, a fine-scale HPT dataset in both spatial and temporal dimensions is urgently needed. Here we construct a daily high-resolution (~1 km) human thermal index collection over NCP from 2003 to 2020 (HiTIC-NCP). This dataset contains 12 HPT indices and has high accuracy with averaged determination coefficient, mean absolute error, and root mean squared error of 0.987, 0.970 °C, and 1.292 °C, respectively. Moreover, it exhibits high spatiotemporal consistency with ground-level observations. The dataset provides a reference for human thermal environment and could facilitate studies such as natural hazards, regional climate change, and urban planning.


Asunto(s)
Percepción , Temperatura , Femenino , Humanos , Embarazo , China , Cambio Climático , Humedad , Trabajo de Parto
3.
Plant Dis ; 107(11): 3575-3584, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37198724

RESUMEN

The recently emerged beech leaf disease (BLD) is causing the decline and death of American beech in North America. First observed in 2012 in northeast Ohio, U.S.A., BLD had been documented in 10 northeastern states and the Canadian province of Ontario as of July 2022. A foliar nematode has been implicated as the causal agent, along with some bacterial taxa. No effective treatments have been documented in the primary literature. Irrespective of potential treatments, prevention and prompt eradication (rapid responses) remain the most cost-effective approaches to the management of forest tree disease. For these approaches to be feasible, however, it is necessary to understand the factors that contribute to BLD spread and use them in estimation of risk. Here, we conducted an analysis of BLD risk across northern Ohio, western Pennsylvania, western New York, and northern West Virginia, U.S.A. In the absence of symptoms, an area cannot necessarily be deemed free of BLD (i.e., absence of BLD cannot be certain) due to its fast spread and the lag in symptom expression (latency) after infection. Therefore, we employed two widely used presence-only species distribution models (SDMs), one-class support vector machine (OCSVM), and maximum entropy (Maxent) to predict the spatial pattern of BLD risk based on BLD presence records and associated environmental variables. Our results show that both methods work well for BLD environmental risk modeling purposes, but Maxent outperforms OCSVM with respect to both the quantitative receiver operating characteristics (ROC) analysis and the qualitative evaluation of the spatial risk maps. Meanwhile, the Maxent model provides a quantification of variable contribution for different environmental factors, indicating that meteorological (isothermality and temperature seasonality) and land cover type (closed broadleaved deciduous forest) factors are likely key contributors to BLD distribution. Moreover, the future trajectories of BLD risk over our study area in the context of climate change were investigated by comparing the current and future risk maps obtained by Maxent. In addition to offering the ability to predict where the disease may spread next, our work contributes to the epidemiological characterization of BLD, providing new lines of investigation to improve ecological or silvicultural management. Furthermore, this study shows strong potential for extension of environmental risk mapping over the full American beech distribution range so that proactive management measures can be put in place. Similar approaches can be designed for other significant or emerging forest pest problems, contributing to overall management efficiency and efficacy.


Asunto(s)
Fagus , Estados Unidos , Bosques , New England , Hojas de la Planta , Ontario
4.
Front Immunol ; 13: 939523, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36091049

RESUMEN

Background: Glioblastoma (GBM) is the most prominent and aggressive primary brain tumor in adults. Anoikis is a specific form of programmed cell death that plays a key role in tumor invasion and metastasis. The presence of anti-anoikis factors is associated with tumor aggressiveness and drug resistance. Methods: The non-negative matrix factorization algorithm was used for effective dimension reduction for integrated datasets. Differences in the tumor microenvironment (TME), stemness indices, and clinical characteristics between the two clusters were analyzed. Difference analysis, weighted gene coexpression network analysis (WGCNA), univariate Cox regression, and least absolute shrinkage and selection operator regression were leveraged to screen prognosis-related genes and construct a risk score model. Immunohistochemistry was performed to evaluate the expression of representative genes in clinical specimens. The relationship between the risk score and the TME, stemness, clinical traits, and immunotherapy response was assessed in GBM and pancancer. Results: Two definite clusters were identified on the basis of anoikis-related gene expression. Patients with GBM assigned to C1 were characterized by shortened overall survival, higher suppressive immune infiltration levels, and lower stemness indices. We further constructed a risk scoring model to quantify the regulatory patterns of anoikis-related genes. The higher risk score group was characterized by a poor prognosis, the infiltration of suppressive immune cells and a differentiated phenotype, whereas the lower risk score group exhibited the opposite effects. In addition, patients in the lower risk score group exhibited a higher frequency of isocitrate dehydrogenase (IDH) mutations and a more sensitive response to immunotherapy. Drug sensitivity analysis was performed, revealing that the higher risk group may benefit more from drugs targeting the PI3K/mTOR signaling pathway. Conclusion: We revealed potential relationships between anoikis-related genes and clinical features, TME, stemness, IDH mutation, and immunotherapy and elucidated their therapeutic value.


Asunto(s)
Anoicis , Neoplasias Encefálicas , Glioblastoma , Isocitrato Deshidrogenasa , Microambiente Tumoral , Algoritmos , Anoicis/genética , Anoicis/inmunología , Neoplasias Encefálicas/diagnóstico , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/inmunología , Neoplasias Encefálicas/terapia , Glioblastoma/diagnóstico , Glioblastoma/genética , Glioblastoma/inmunología , Glioblastoma/terapia , Humanos , Inmunoterapia , Isocitrato Deshidrogenasa/genética , Isocitrato Deshidrogenasa/inmunología , Mutación , Células Madre Neoplásicas/fisiología , Pronóstico , Medición de Riesgo , Microambiente Tumoral/genética , Microambiente Tumoral/inmunología
5.
Sci Total Environ ; 799: 149166, 2021 Dec 10.
Artículo en Inglés | MEDLINE | ID: mdl-34364272

RESUMEN

Summertime extreme heat events exert severe impacts on the natural environment and human society, especially in densely populated and highly urbanized regions. While previous studies have focused on independent heat day/night, there is a lack of attention to the changes in compound events with cooccurring daytime and nighttime extreme temperature on the same day. In this study, we examine the spatio-temporal changes of summertime compound heat extremes (including compound heat day and compound heatwave) across China, with a particular focus on 20 major urban agglomerations (UAs), and quantify the urbanization effects on these changes. We find that the frequency and fraction of compound heat events show obvious spatial disparities across China. The compound heat events occur more frequently in highly populated and urbanized areas such as the Pearl River Delta. Moreover, the frequency and fraction of compound heat events have significantly increased in recent decades in most parts of China, especially in more developed UAs. These intensifying trends have even accelerated in more recent decades. Our further investigations suggest that most UAs of China experienced an intensifying urbanization effect on compound heat events, and few UAs in northwestern and central China (e.g., UAs of the north Tianshan mountain and the middle reaches of the Yangtze River) display a weakening effect of urbanization. Our findings highlight the important role of urbanization in increasing compound heat extremes and suggest that the increasing threats of compound events in urban areas should be given more attention under the context of global warming and local urbanization.


Asunto(s)
Calor , Urbanización , China , Ciudades , Calentamiento Global , Humanos , Ríos
7.
Sci Total Environ ; 744: 140264, 2020 Nov 20.
Artículo en Inglés | MEDLINE | ID: mdl-32755767

RESUMEN

Unprecedented urbanization in China facilitates the rapid development of urban agglomerations (UAs) and may exert prominent effects on regional climate and environment change. By analyzing a set of 27 extreme temperature and precipitation indices, this study examines the changes in extreme climate events in 20 UAs in China and evaluates the urbanization effects using a dynamic classification of urban and rural stations by time-varying land use/cover maps. The regional differences of the urbanization effects on extreme climate events are also investigated by a k-means clustering. It is found that, for both temperature and precipitation extremes, the urban and rural areas exhibit remarkably distinct changes and demonstrate significant urbanization effect, which also varies across different climate backgrounds. Urbanization profoundly contributes to increasing hot extremes and reducing cold extremes in most UAs, while it seems to pose the opposite effects in several UAs of arid and high-latitude regions. On average, the urbanization effect accounts for around 30% of the total change in extreme temperature events over the urban core areas of 20 UAs. On the other hand, the urbanization effects on extreme precipitation indices display stronger regional discrepancies than temperature extremes. Urbanization tends to have weakening effects on extreme precipitation events in UAs over coastal regions and intensifying influences on those in central/west China. It causes more (less) frequent and more (less) intense precipitation in UAs of inland central/west (coastal) areas. Our findings provide a systematic understanding of the urbanization effects on extreme climate and may have important implications for the mitigation of urban disasters.

8.
Transl Cancer Res ; 9(12): 7432-7439, 2020 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-35117343

RESUMEN

BACKGROUND: Glioblastoma (GB) is the most common and aggressive brain and central nervous system malignancy. MicroRNAs (miRNAs) have been demonstrated to be predictors of prognostic outcomes, playing an important role in the pathogenesis and progression of GB. We aim to identify the potential miRNAs in GB. METHODS: GSE103228 was downloaded from the Gene Expression Omnibus (GEO) database to identify differentially expressed miRNAs (DE-miRNAs) using the Student's t-test. Potential target genes for DE-miRNAs were predicted using miRTarBase, and their functions were analyzed using Gene Ontology (GO) annotation and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses. The protein-protein interaction (PPI) network was constructed using the STRING database and visualized using Cytoscape to identify a hub target gene-miRNA network. Furthermore, the expression of GB target genes was verified using University of Alabama Cancer (UALCAN) database. RESULTS: A total of 49 DE-miRNAs were identified in GB including 30 down-regulated miRNAs and 19 up-regulated miRNAs. Our analysis predicted 1,118 and 1,063 potential target genes from the top three most up-regulated and down-regulated DE-miRNAs, respectively, that were enriched in several GB-related pathways including the cancer pathway. ACTB and MYC were considered to be hub genes in our PPI networks. CONCLUSIONS: MiR-218-5p and miR-148a-3p regulated most of the hub genes and miR-148a-3p appeared to be a prognostic biomarker.

9.
Sci Total Environ ; 688: 389-397, 2019 Oct 20.
Artículo en Inglés | MEDLINE | ID: mdl-31233919

RESUMEN

Human-perceived wind chill describes the combined effects of wind velocity and low temperature, strongly related to human health and natural environment. Although long-term trends in the air or ambient temperature over China under global warming have been well studied in the literature, the changes in human-perceived wind chill conditions, especially under possible urbanization effects, are still not completely known. This paper investigates the changes of wind chill over China and quantifies the associated urbanization effect by examining nearly 2000 meteorological stations during 1961-2014 using the generalized additive model (GAM). Results show that the winter wind chill temperature (WCT) in China exhibits more prominent raising trends than the air temperature, i.e., 0.623 and 0.349 °C per decade, respectively. The wind speed (V) and wind chill days (WCD) decreased by 0.149 m/s and 1.970 days per decade, respectively. These trends become more substantial in densely populated and highly urbanized areas such as the North China Plain. The expansion of urban built-up area induces additional warming (reducing) to the increase (decrease) in WCT (WCD). On average, an increase from 0% to 100% in the urban fraction induced 0.290 ±â€¯0.067 °C higher WCT (± denotes the 95% confidence interval), along with a reduction in V and WCD by 0.052 ±â€¯0.014 m/s and 3.513 ±â€¯0.387 days, respectively; whereas, the presence of the grassland and forest significantly diminishes the WCT and increases the WCD and surface V. It is expected that wind chill over China tends to be weakened under glocal warming and local urbanization in the near future. Our results have important implications for climate change mitigation, urban planning, landscape design, and air pollution abatement.

10.
Mol Phylogenet Evol ; 98: 201-9, 2016 May.
Artículo en Inglés | MEDLINE | ID: mdl-26876638

RESUMEN

Cryptocercus is a genus of sub-social wood-feeding cockroaches that represents the sister group to the eusocial termites. We generated mitochondrial (12S+16S rRNA, COII), nuclear (28S rRNA) and Blattbacterium endosymbiont (16S+23S rRNA) sequence data for 8 new Chinese species, and combined these with previously available data to undertake the most extensive analysis of phylogenetic relationships within the genus to date. As expected, phylogenetic relationships among Blattabacterium strains were found to be congruent with those of their hosts. Three major clades were found to exist in Asian populations, one representing taxa from the Hengduan mountains in Southwestern China, a second including taxa from Russia, Korea, Northeastern China, and Yunnan in the Hengduan Mountains, and a third including taxa from the Qinling Mountains and Daba Mountains in Central China. A molecular dating analysis using 7 termite fossils to calibrate the molecular clock indicated that the divergence of American and Asian Cryptocercus occurred 55.09Ma (41.55-72.28Ma 95% CI), and that the radiations of American and Asian taxa occurred 28.48Ma (20.83-37.95Ma 95% CI) and 20.97Ma (15.78-27.21Ma 95% CI) respectively. Reconstruction of ancestral geographic distributions using S-DIVA suggested Cryptocercus was originally distributed across both continents, as opposed to ancestral migration of Cryptocercus from one continent to the other. The last common ancestor of Asian Cryptocercus was inferred to have existed in Central China. An examination of male chromosome numbers in Asian Cryptocercus showed that diploid numbers vary from 2n=15 to 2n=41, and indicates the presence of eight new species. Our study represents the most comprehensive phylogenetic and biogeographic study yet performed for this important group of cockroaches.


Asunto(s)
Cucarachas/clasificación , Cucarachas/genética , Evolución Molecular , Filogenia , Animales , Asia , Fósiles , Isópteros/genética , Masculino , América del Norte , Filogeografía , ARN Ribosómico/genética , Factores de Tiempo
11.
Acta Cir Bras ; 29(6): 359-64, 2014 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-24919043

RESUMEN

PURPOSE: To determine the role of mesenteric lymph reperfusion (MLR) on endotoxin translocation in brain to discuss the mechanism of brain injury subjected to superior mesenteric artery occlusion (SMAO) shock. METHODS: Twenty-four rats were randomly assigned to MLR, SMAO, MLR+SMAO and sham groups. MLR was performed by clamping the mesenteric lymph duct (MLD) for 1 h and then allowing reperfusion for 2 h in the MLR group; SMAO involved clamping the superior mesenteric artery (SMA) for 1 h, followed by reperfusion for 2 h in the SMAO group; occlusion of both the SMA and MLD for 1 h was followed by reperfusion for 2 h in the MLR+SMAO group rats. RESULTS: SMAO shock induced severe increased levels of the endotoxin, lipopolysaccharide receptor, lipopolysaccharide-binding protein, intercellular adhesion molecule-1 and tumor necrosis factor-α. Concurrently, MLR after SMAO shock further aggravates these deleterious effects. CONCLUSION: Mesenteric lymph reperfusion exacerbated the endotoxin translocation in brain; thereby increased inflammatory response occurred, suggesting that the intestinal lymph pathway plays an important role in the brain injury after superior mesenteric artery occlusion shock.


Asunto(s)
Traslocación Bacteriana/fisiología , Lesiones Encefálicas/etiología , Endotoxinas/fisiología , Vasos Linfáticos/fisiología , Oclusión Vascular Mesentérica/fisiopatología , Mesenterio , Daño por Reperfusión/fisiopatología , Proteínas de Fase Aguda/análisis , Animales , Lesiones Encefálicas/metabolismo , Proteínas Portadoras/análisis , Modelos Animales de Enfermedad , Endotoxinas/análisis , Ensayo de Inmunoadsorción Enzimática , Molécula 1 de Adhesión Intercelular/análisis , Ligadura , Receptores de Lipopolisacáridos/análisis , Vasos Linfáticos/cirugía , Masculino , Glicoproteínas de Membrana/análisis , Arteria Mesentérica Superior , Oclusión Vascular Mesentérica/complicaciones , Distribución Aleatoria , Ratas Wistar , Daño por Reperfusión/complicaciones , Factores de Tiempo , Factor de Necrosis Tumoral alfa/análisis
12.
Acta cir. bras ; 29(6): 359-364, 06/2014. graf
Artículo en Inglés | LILACS | ID: lil-711592

RESUMEN

PURPOSE: To determine the role of mesenteric lymph reperfusion (MLR) on endotoxin translocation in brain to discuss the mechanism of brain injury subjected to superior mesenteric artery occlusion (SMAO) shock. METHODS: Twenty-four rats were randomly assigned to MLR, SMAO, MLR+SMAO and sham groups. MLR was performed by clamping the mesenteric lymph duct (MLD) for 1 h and then allowing reperfusion for 2 h in the MLR group; SMAO involved clamping the superior mesenteric artery (SMA) for 1 h, followed by reperfusion for 2 h in the SMAO group; occlusion of both the SMA and MLD for 1 h was followed by reperfusion for 2 h in the MLR+SMAO group rats. RESULTS: SMAO shock induced severe increased levels of the endotoxin, lipopolysaccharide receptor, lipopolysaccharide-binding protein, intercellular adhesion molecule-1 and tumor necrosis factor-α. Concurrently, MLR after SMAO shock further aggravates these deleterious effects. CONCLUSION: Mesenteric lymph reperfusion exacerbated the endotoxin translocation in brain; thereby increased inflammatory response occurred, suggesting that the intestinal lymph pathway plays an important role in the brain injury after superior mesenteric artery occlusion shock. .


Asunto(s)
Animales , Masculino , Traslocación Bacteriana/fisiología , Lesiones Encefálicas/etiología , Endotoxinas/fisiología , Vasos Linfáticos/fisiología , Mesenterio , Oclusión Vascular Mesentérica/fisiopatología , Daño por Reperfusión/fisiopatología , Proteínas de Fase Aguda/análisis , /análisis , Lesiones Encefálicas/metabolismo , Proteínas Portadoras/análisis , Modelos Animales de Enfermedad , Ensayo de Inmunoadsorción Enzimática , Endotoxinas/análisis , Molécula 1 de Adhesión Intercelular/análisis , Ligadura , Vasos Linfáticos/cirugía , Arteria Mesentérica Superior , Glicoproteínas de Membrana/análisis , Oclusión Vascular Mesentérica/complicaciones , Distribución Aleatoria , Ratas Wistar , Daño por Reperfusión/complicaciones , Factores de Tiempo , Factor de Necrosis Tumoral alfa/análisis
13.
Artículo en Chino | MEDLINE | ID: mdl-22493902

RESUMEN

OBJECTIVE: To investigate the role of mesenteric lymph reperfusion (MLR) aggravates multiple organs injury in superior mesenteric artery occlusion (SMAO) shock and its mechanism. METHODS: Twenty four Wistar rats were randomly divided into 4 groups (n = 6): Sham group (only anesthetized and operated), MLR group rats performed 1 h occlusion of mesenteric lymph duct (MLD), then followed by 2 h of reperfusion, SMAO group (rats performed 1 h occlusion of superior mesenteric artery (SMA) and then followed by 2 h of reperfusion), SMAO + MLR group (rats performed 1 h occlusion of SMA and MLD and then followed by 2 h of reperfusion). The blood sample was taken out from abdominal aortic for plasma and the liver, kidney, myocardium, lung tissues in fixed position were prepared for making homogenate after reperfusion of 2 h respectively. And the levels of endotoxin (ET) in plasma and homogenates were determined with kinetic turbidimetric technique of tachypleus amebocyte lysate, the contents of lipopolysaccharide-binding protein (LBP), lipopolysaccharide receptor (CD14) and tumor necrosis factor-alpha (TNF-alpha) in homogenates were determined with enzyme-linked immunosorbent assay method. RESULTS: The indices have no statistics difference between sham group and MLR group. The ET levels of the plasma and hepatic, renal, myocardial, pulmonary homogenates in SMAO and SMAO + MLR groups were significant higher than that of sham and MLR groups, and these indices in SMAO + MLR were increased significantly than those in SMAO group. The CD14, LBP and TNF-alpha contents of the hepatic, renal, myocardial and pulmonary homogenates in SMAO and SMAO + MLR groups were significant higher than those in sham and MLR groups, and these indices in SMAO+ MLR were higher than SMAO group significantly. CONCLUSION: The mechanism of MLR aggravates multiple organs injury in SMAO shock may be associated with enterogenous ET through intestinal lymphatic pathway to translocate, activate the LBP/CD14 as endotoxin sensitizing system and promote inflammatory response.


Asunto(s)
Vasos Linfáticos/patología , Daño por Reperfusión/patología , Choque Séptico/patología , Animales , Endotoxinas , Intestinos/irrigación sanguínea , Masculino , Arteria Mesentérica Superior/patología , Ratas , Ratas Wistar
14.
Artículo en Chino | MEDLINE | ID: mdl-21328991

RESUMEN

OBJECTIVE: To observe the effects of mesenteric lymph duct (MLD) ligation on erythrocyte rheology in acute hemorrhagic rats. METHODS: Twenty male Wistar rats were randomly divided into hemorrhage group and ligation group (n = 10). Blood (one fourth of body whole blood volume) was withdrawn through right common carotid arteries after rats were anesthetized. In ligation group, the MLD was ligated after hemorrhage, and only threading under the MLD in hemorrhage group. The survival situation at 24 h was recorded. After 24 h, survival rats were anesthetized again, blood sample was withdrawn through left common carotid artery rapidly. And the erythrocyte sedimentation rate (ESR), electrophoresis of erythrocytes, hematocrit (Hct) were determined in blood samples of before and after hemorrhage, the erythrocytes aggregation and deformability indices were calculated. RESULTS: It showed that the ligation group survival (9 rats alive) was slightly better than that in hemorrhage group (6 rats alive). The results of erythrocyte rheology indices showed that the ESR, K value of equation, K value of emendation and electrophoresis time in hemorrhage group and ligation group were higher or longer than those before hemorrhage, the erythrocyte deformability was reduced significantly, respectively. And the erythrocytes aggregation index in hemorrhage group was increased, the electrophoresis length and migration of erythrocyte in hemorrhage group were lower than those before hemorrhage, respectively. But compared with hemorrhage group, the ESR, K value of equation, K value of emendation, erythrocytes aggregation index and electrophoresis time in ligation group were lower, the electrophoresis lenght, migration and deformability of erythrocyte were increased significantly. CONCLUSION: The results indicate that the higher erythrocyte aggregation ability, lower electrophoresis function and deformability are caused by acute hemorrhage in rats, and the MLD ligation can improve the abnormal erythrocyte rheology.


Asunto(s)
Eritrocitos/patología , Hemorragia/cirugía , Vasos Linfáticos/cirugía , Choque Hemorrágico/cirugía , Animales , Modelos Animales de Enfermedad , Deformación Eritrocítica , Ligadura , Masculino , Mesenterio/cirugía , Ratas , Ratas Wistar , Reología
15.
Zhongguo Wei Zhong Bing Ji Jiu Yi Xue ; 21(12): 708-10, 2009 Dec.
Artículo en Chino | MEDLINE | ID: mdl-20042133

RESUMEN

OBJECTIVE: To observe the effects of mesenteric lymph duct ligation on platelet function, thrombus formation in vitro and coagulation function in rats with acute loss of blood, and investigate the role of intestinal lymphatic pathway on coagulability change during acute loss of blood. METHODS: Twenty male Wistar rats were randomly divided into loss of blood group (n=10) and ligation group (n=10). The acute loss of blood model was reproduced by withdrawing blood (one fourth of body whole blood volume) with an automatic withdrawal-infusion machine through right common carotid artery. In ligation group, the mesenteric lymph duct was ligated after loss of blood, and in loss of blood group only a thread was passed under the mesenteric lymph duct. The rats' survival rate at 24 hours was recorded. After 24 hours, surviving rats were anesthetized again, and 6 ml of blood was with drew from left common carotid artery rapidly. The platelet adhesive rate, platelet aggregation rate, thrombus formation in vitro, coagulation function were determined before and after experiment, and the cerebral blood flow was measured. RESULTS: There were 6 rats alive in loss of blood group (60%), and 9 rats alive in ligation group (90%). The platelet adhesive rate, platelet aggregation rate, fibrinogen (Fib) content were increased in both groups, and cerebral blood flow was lower compared with before experiment significantly. The activated partial thromboplastin time (APTT) in loss of blood group, and thrombin time (TT) in both groups were prolonged. And the length of wet thrombus, wet weight of thrombus, length of dry thrombus, dry weight of thrombus and thrombus formation rate in loss of blood group were significantly increased compared with before experiment (P<0.05 or P<0.01). But in ligation group, the platelet adhesive rate [(15.02+/-1.24)%], platelet aggregation rate (at 1 minute, 3 minutes and max aggregation rate), length of wet thrombus, wet weight of thrombus, length of dry thrombus, dry weight of thrombus, thrombus formation rate [(46.2+/-6.9)%], APTT [(21.04+/-5.53)s] and Fib content [(433.67+/-13.97) g/L] were lower, cerebral blood flow [(485.1+/-41.4) ml x kg(-1) x min(-1)] was higher compared with loss of blood group, respectively [(18.54+/-1.18)%, (69.8+/-6.9)%, (26.35+/-6.26)s, (510.96+/-35.59) g/L, (417.8+/-42.2) ml x kg(-1) x min(-1), P<0.05 or P<0.01]. CONCLUSION: The results indicate that acute loss of blood leads to coagulation and increased thrombosis, and mesenteric lymph duct ligation can improve hypercoagulability of blood.


Asunto(s)
Hemorragia/sangre , Vasos Linfáticos/cirugía , Mesenterio , Animales , Coagulación Sanguínea , Modelos Animales de Enfermedad , Ligadura , Masculino , Adhesividad Plaquetaria , Distribución Aleatoria , Ratas , Ratas Wistar
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