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1.
Heliyon ; 9(11): e21011, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37920504

RESUMO

Aging is associated with gradual changes in liver structure, altered metabolites and other physiological/pathological functions in hepatic cells. However, its characterized phenotypes based on altered metabolites and the underlying biological mechanism are unclear. Advancements in high-throughput omics technology provide new opportunities to understand the pathological process of aging. Here, in our present study, both metabolomics and phosphoproteomics were applied to identify the altered metabolites and phosphorylated proteins in liver of young (the WTY group) and naturally aged (the WTA group) mice, to find novel biomarkers and pathways, and uncover the biological mechanism. Analysis showed that the body weights, alanine aminotransferase (ALT) and aspartate aminotransferase (AST) increased in the WTA group. The grips decreased with age, while the triglyceride (TG) and cholesterol (TC) did not change significantly. The increase of fibrosis, accumulation of inflammatory cells, hepatocytes degeneration, the deposition of lipid droplets and glycogen, the damaged mitochondria, and deduction of endoplasmic reticulum were observed in the aging liver under optical and electron microscopes. In addition, a network of metabolites and phosphorylated proteomes of the aging liver was established. Metabolomics detected 970 metabolites in the positive ion mode and 778 metabolites in the negative ion mode. A total of 150 pathways were pooled. Phosphoproteomics identified 2618 proteins which contained 16621 phosphosites. A total of 164 pathways were detected. 65 common pathways were detected in two omics. Phosphorylated protein heat shock protein HSP 90-alpha (HSP90A) and v-raf murine viral oncogene homolog B1(BRAF), related to cancer pathway, were significantly upregulated in aged mice liver. Western blot verified that protein expression of MEK and ERK, downstream of BRAF pathway were elevated in the liver of aging mice. However, the protein expression of BRAF was not a significant difference. Overall, these findings revealed a close link between aging and cancer and contributed to our understanding of the multi-omics changes in natural aging.

2.
Mol Cell Proteomics ; 22(2): 100494, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36621768

RESUMO

AMP-activated protein kinase alpha 2 (AMPKα2) regulates energy metabolism, protein synthesis, and glucolipid metabolism myocardial cells. Ketone bodies produced by fatty acid ß-oxidation, especially ß-hydroxybutyrate, are fatty energy-supplying substances for the heart, brain, and other organs during fasting and long-term exercise. They also regulate metabolic signaling for multiple cellular functions. Lysine ß-hydroxybutyrylation (Kbhb) is a ß-hydroxybutyrate-mediated protein posttranslational modification. Histone Kbhb has been identified in yeast, mouse, and human cells. However, whether AMPK regulates protein Kbhb is yet unclear. Hence, the present study explored the changes in proteomics and Kbhb modification omics in the hearts of AMPKα2 knockout mice using a comprehensive quantitative proteomic analysis. Based on mass spectrometry (LC-MS/MS) analysis, the number of 1181 Kbhb modified sites in 455 proteins were quantified between AMPKα2 knockout mice and wildtype mice; 244 Kbhb sites in 142 proteins decreased or increased after AMPKα2 knockout (fold change >1.5 or <1/1.5, p < 0.05). The regulation of Kbhb sites in 26 key enzymes of fatty acid degradation and tricarboxylic acid cycle was noted in AMPKα2 knockout mouse cardiomyocytes. These findings, for the first time, identified proteomic features and Kbhb modification of cardiomyocytes after AMPKα2 knockout, suggesting that AMPKα2 regulates energy metabolism by modifying protein Kbhb.


Assuntos
Ácido 3-Hidroxibutírico , Proteínas Quinases Ativadas por AMP , Miocárdio , Animais , Humanos , Camundongos , Ácido 3-Hidroxibutírico/química , Ácido 3-Hidroxibutírico/metabolismo , Proteínas Quinases Ativadas por AMP/genética , Proteínas Quinases Ativadas por AMP/metabolismo , Cromatografia Líquida , Camundongos Endogâmicos C57BL , Camundongos Knockout , Miocárdio/metabolismo , Proteômica , Espectrometria de Massas em Tandem
3.
Arch Biochem Biophys ; 731: 109430, 2022 11 30.
Artigo em Inglês | MEDLINE | ID: mdl-36326546

RESUMO

Diabetic cardiovascular complication is a common systemic disease with high morbidity and mortality worldwide. We hypothesise that exosomes derived from human umbilical cord mesenchymal stem cells (hUCMSCs-exos) can rescue these disorders and alleviate vascular remodeling in diabetes. Morphological, non-targeted metabolomics and 4D label-free proteomics techniques were used to analyze the aortas of db/m mice as normal control group (NCA), saline treated db/db mice (DMA), and hUCMSCs-exos treated db/db mice (DMTA), and to clarify the molecular mechanism of the protection of hUCMSCs-exos in vascular remodeling from a new point of view. The results showed that 74 metabolites were changed significantly in diabetic aortas, of which 15 were almost restored by hUCMSCs-exos. In proteomics, 30 potential targets such as Stromal cell-derived factor 2-like protein 1, Leukemia inhibitory factor receptor, Peroxisomal membrane protein and E3 ubiquitin-protein ligase MYCBP2 were detected. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway-based analysis showed that Central carbon metabolism in cancer and Galactose metabolism pathway were up-regulated to near normal by hUCMSCs-exos in metabolomics, with janus associated kinase-signal transducer and activator of transcription (JAK-STAT) pathway displayed in proteomics. According to bioinformatics and integrated analysis, these targeted molecules of hUCMSCs-exos to attenuate the vascular remodeling were mainly associated with regulation of energy metabolism, oxidative stress, inflammation, and cellular communications. This study provided a reference for the therapy of diabetes-induced cardiovascular complications.


Assuntos
Exossomos , Células-Tronco Mesenquimais , Humanos , Camundongos , Animais , Exossomos/metabolismo , Cordão Umbilical , Proteômica , Remodelação Vascular , Células-Tronco Mesenquimais/metabolismo , Aorta
4.
Rev Cardiovasc Med ; 23(3): 89, 2022 Mar 09.
Artigo em Inglês | MEDLINE | ID: mdl-35345256

RESUMO

OBJECTIVES: Although injury of myocardium after percutaneous coronary intervention (PCI) has been reported, the mechanism and effect of exogenous phosphocreatine (PCr) supplementation on the injury are yet to be elucidated. Biomarkers, such as interleukin-6 (IL-6) and variations in white blood cells for inflammation, and serum cardiac troponin I (cTnI) for myocardial injury are examined. METHODS: A total of 105 patients undergoing PCI were included and randomly divided into two groups: control (treated with routine hydration therapy) and PCr (treated with additional intravenous infusion of exogenous PCr). The serum levels of biomarkers were detected at administration and 4, 12, 24, and 48 h after PCI, with natural logarithmic (loge) transformation of data when modeling assumptions were not fulfilled. RESULTS: The level of loge-transformed IL-6 increased in both groups, especially at 12 and 24 h after the operation, and that of PCr group was less than the control group at 48 h. The content of loge-transformed cTnI was significantly increased in both groups, while that of the PCr group was markedly lower than the control group at all time points after PCI. Moreover, the ratio of neutrophils was elevated at all time points after PCI, while that of the PCr group was lower at 48 h, and the variations in the ratio of lymphocytes showed opposite results. CONCLUSIONS: Exogenous phosphocreatine reduces stent implantation, triggers inflammation manifested as decreased serum levels of IL-6 and the aggregation of neutrophils, and protects the myocardium of the patients undergoing PCI. These findings provided the potential mechanism and treatment for myocardial injury associated with PCI.


Assuntos
Inflamação , Intervenção Coronária Percutânea , Fosfocreatina , Biomarcadores , Humanos , Inflamação/prevenção & controle , Interleucina-6 , Miocárdio , Intervenção Coronária Percutânea/efeitos adversos , Fosfocreatina/uso terapêutico , Troponina I
5.
Aging (Albany NY) ; 11(16): 6358-6370, 2019 08 22.
Artigo em Inglês | MEDLINE | ID: mdl-31437127

RESUMO

GP IIb/IIIa receptor activation plays an important role in thrombosis. The mechanism of early activation of GP IIb/IIIa receptors in diabetic conditions remains unknown. The purpose of this study was to investigate the release of Endothelial microparticle (EMP)-associated protein disulfide isomerase (PDI) after endothelial cell injury induced in diabetes and the changes in platelet activation. We produced an animal model of type 2 diabetes mellitus using ApoE-/- mice. Normal ApoE-/- and diabetic mice were allocated to four groups (n = 15): normal diet, normal diet plus rutin, diabetic, and diabetes plus rutin. The EMP-PDI content and GP IIb/IIIa expression of mice platelets were determined. In addition, EMPs obtained from the four groups were pretreated with the PDI inhibitor rutin; then, their effects on the platelets of normal C57 mice were characterized. Compared with the normal diet group, the diabetic group had significantly increased plasma EMP-PDI content and accelerated platelet activation by increased GP IIb/IIIa expression. In conclusion, EMP-PDI promotes early platelet activation through glycoprotein (GP) IIb/IIIa receptors present on platelet surface in the diabetic state. However, this process could be partially suppressed by the administration of rutin.


Assuntos
Diabetes Mellitus Tipo 2/metabolismo , Células Endoteliais/metabolismo , Ativação Plaquetária/efeitos dos fármacos , Complexo Glicoproteico GPIIb-IIIa de Plaquetas/metabolismo , Isomerases de Dissulfetos de Proteínas/metabolismo , Animais , Regulação da Expressão Gênica/efeitos dos fármacos , Regulação da Expressão Gênica/fisiologia , Masculino , Camundongos , Camundongos Knockout para ApoE , Rutina/farmacologia
6.
Ying Yong Sheng Tai Xue Bao ; 30(5): 1599-1607, 2019 May.
Artigo em Chinês | MEDLINE | ID: mdl-31107016

RESUMO

With the flux data of ChinaFLUX and the concurrent satellite remote sensing data in Changbai Mountain, we recombined parameters of four models, i.e., vegetation photosynthesis model (VPM), eddy covariance-light utility efficiency model (EC-LUE), terrestrial ecosystem model (TEM) and Carnegie-Ames-Stanford approach model (CASA) within 3PG model. The most suitable parameters of 3PG model were determined by comparing the root mean square error, coefficient of determination and average error between measured and observed flux values. To improve its accuracy in estimating gross primary productivity (GPP) of broadleaved Korean pine forest in Changbai Mountain, the fitness of the optimal model was validated using the observed flux data. The results showed that when temperature, enhanced vegetation index, and surface water index were used to characterize the temperature limiting factor, photosynthetic active radiation absorption ratio and water limiting factor in the original model to estimate GPP of broadleaved Korean pine forest, the simulation results were the best. The precision of the optimized model (R2=0.948, RMSE=0.035 mol·m-2·month-1) was better than that of the original model (R2=0.854, RMSE=0.177 mol·m-2·month-1), which could effectively improve the phenomenon of obvious overestimation of the original model in the growing season. Results from the parameter sensitivity analysis showed that the uncertainty of GPP estimation was dominated by temperature, followed by enhanced vegetation index, photosynthetically active radiation and land surface water index, as well as their interactions.


Assuntos
Carbono/análise , Ecossistema , Monitoramento Ambiental , Modelos Estatísticos , Pinus , China , Florestas , Fotossíntese
7.
Biogerontology ; 20(2): 203-211, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30519860

RESUMO

Senescence-associated secretory phenotype (SASP) plays a role in aging adipose tissue dysfunction by directly promoting chronic inflammation. The JNK/p53 pathway was reported as a potential mechanism that mediates SASP. In this study, we investigated the effects of L-carnitine, an inhibitor of the JNK/p53 pathway in adipose tissue SASP and dysfunction. Young and aging rat were given L-carnitine by gavage. Next, we detected the senescence, cytokines expression, chronic inflammation and insulin resistance of adipose tissue. Additionally, JNK/p53 pathway was estimated. Our results show a significant increase expression of SASP components in the adipose tissue of aging rats compared to young rats. Further, we found that infiltration of immune cells and the expression of pro-inflammatory cytokines were enhanced in aging adipose tissue while insulin signaling activity was reduced in aging adipose tissue. Interestingly, L-carnitine markedly reduced the expression of SASP factors. L-Carnitine could significantly reduce chronic inflammation, improving insulin resistance. Further, L-carnitine inhibited SASP by inhibiting JNK/p53 pathway. L-Carnitine inhibited SASP by JNK/p53 pathway and attenuated adipose tissue dysfunction of aging.


Assuntos
Tecido Adiposo/metabolismo , Envelhecimento/fisiologia , Carnitina , Senescência Celular , Animais , Carnitina/metabolismo , Carnitina/farmacologia , Senescência Celular/efeitos dos fármacos , Senescência Celular/fisiologia , Inflamação/metabolismo , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Sistema de Sinalização das MAP Quinases/fisiologia , Ratos , Transdução de Sinais/efeitos dos fármacos
8.
Oncotarget ; 8(16): 27481-27488, 2017 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-28415694

RESUMO

The association of single nucleotide polymorphisms rs1053239 and rs2479 of cell death-inducing DFFA-like effector c with the risk of metabolic syndrome and its components, and with the efficacy and cost-effectiveness of antihypertensive drugs was investigated. Totally 1064 subjects with metabolic syndrome and 1099 controls of Chinese Han nationality were recruited. Clinical assessment was conducted with medication records collected at baseline and during 5-year follow-up. Carriers of rs2479 A allele were at higher risk to develop elevated fasting glucose than non-carriers (P = 0.004). A allele at rs2479 were associated with a 5-year aggravation of blood triglyceride (P < 0.001) and diastolic blood pressure (P = 0.003), and C allele at rs1053239 with the exacerbation of systolic (P < 0.001) and diastolic blood pressure (P = 0.001). Moreover, efficacy and cost-effectiveness of angiotensin II-targeted drugs were higher in subjects with rs2479 A allele or rs1053239 C allele. These findings suggest that carriers of rs2479 A allele are predisposed to the development of increased fasting glucose, and the progressive elevation of blood triglyceride. Individuals with A allele at rs2479 or C allele at rs1053239 are more susceptible to a rapid progression of blood pressure, and benefit more from angiotensin II-targeted therapy.


Assuntos
Anti-Hipertensivos/uso terapêutico , Estudos de Associação Genética , Predisposição Genética para Doença , Síndrome Metabólica/tratamento farmacológico , Síndrome Metabólica/genética , Polimorfismo de Nucleotídeo Único , Proteínas/genética , Adulto , Anti-Hipertensivos/farmacologia , Proteínas Reguladoras de Apoptose , Estudos de Casos e Controles , Análise Custo-Benefício , Feminino , Seguimentos , Genótipo , Humanos , Masculino , Síndrome Metabólica/epidemiologia , Síndrome Metabólica/metabolismo , Pessoa de Meia-Idade , Vigilância da População , Resultado do Tratamento
9.
Oncotarget ; 7(50): 83231-83240, 2016 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-27825126

RESUMO

BACKGROUND: Metabolic syndrome (MetS) is a common challenge in the world, and the platelet activation is enhanced in MetS patients. However, the fundamental mechanism that underlies platelet activation in MetS remains incompletely understood. Endothelial cells are damaged seriously in MetS patients, then they release more endothelial microparticles (EMPs). After all, whether the EMPs participate in platelet activation is still obscure. If they were, how did they work? RESULTS: We demonstrated that the levels of EMPs, PMPs (platelet derived microparticles) and microparticle-carried-PDI activity increased in MetS patients. IR endothelial cells released more EMPs, the EMP-PDI was more activated. EMPs can enhance the activation of CD62P, GPIIb/IIIa and platelet aggregation and this process can be partly inhibited by PDI inhibitor such as RL90 and rutin. Activated platelets stimulated by EMPs expressed more PDI on cytoplasm and released more PMPs. MATERIALS AND METHODS: We obtained plasma from 23 MetS patients and 8 normal healthy controls. First we built insulin resistance (IR) model of human umbilical vein endothelial cells (HUVECs), and then we separated EMPs from HUVECs culture medium and used these EMPs to stimulate platelets. Levels of microparticles, P-selectin(CD62P), Glycoprotein IIb/IIIa (GPIIb/IIIa) were detected by flow cytometry and levels of EMPs were detected by enzyme-linked immunosorbent assay (ELISA). The protein disulfide isomerase (PDI) activity was detected by insulin transhydrogenase assay. Platelet aggregation was assessed by turbidimetry. CONCLUSION: EMPs can promote the activation of GPIIb/IIIa in platelets and platelet aggregation by the PDI which is carried on the surface of EMPs.


Assuntos
Plaquetas/enzimologia , Micropartículas Derivadas de Células/enzimologia , Células Endoteliais da Veia Umbilical Humana/enzimologia , Síndrome Metabólica/enzimologia , Ativação Plaquetária , Isomerases de Dissulfetos de Proteínas/sangue , Plaquetas/efeitos dos fármacos , Estudos de Casos e Controles , Micropartículas Derivadas de Células/efeitos dos fármacos , Células Cultivadas , Ativação Enzimática , Inibidores Enzimáticos/farmacologia , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Humanos , Síndrome Metabólica/sangue , Selectina-P/sangue , Ativação Plaquetária/efeitos dos fármacos , Agregação Plaquetária , Inibidores da Agregação Plaquetária/farmacologia , Complexo Glicoproteico GPIIb-IIIa de Plaquetas/metabolismo , Isomerases de Dissulfetos de Proteínas/antagonistas & inibidores , Transdução de Sinais , Fatores de Tempo
10.
Ying Yong Sheng Tai Xue Bao ; 27(11): 3469-3478, 2016 Nov 18.
Artigo em Chinês | MEDLINE | ID: mdl-29696843

RESUMO

Forest leaf area index (LAI) is an important indicator to describe the forest canopy structure and growth status of trees. In this paper, the Yigen area of Inner Mongolia was selected as the study area. Taken full account of the differences among different echo types, the LiDAR point cloud data were split into different single lasers. Then, intensity normalization was implemented for LiDAR point cloud data with the range between sensor and target. Based on the normalized intensity data, a new laser penetration index, called single laser beam penetration index (LPIs), was calculated along with the calculation of traditional LPI. These two laser penetration indexes were used to estimate the forest LAI based on the theoretical model and empirical model on four different sampling scales (5, 10, 15, and 20 m), respectively, which aimed to improve the retrieval accuracy of forest LAI through laser beam splitting. The results showed that the forest LAI estimated from mean LPIs (LPImean) was obviously better than that from traditional LPI. In addition, both of the empirical [R2=0.80, mean absolute deviation (MAD)=0.11] and theoretical models (R2=0.77, MAD=0.16) achieved the best performances with sampling scale of 15 m. The mapping of birch forest LAI for the study area was derived by integrating both the advantages of best empirical and theoretical models.


Assuntos
Betula/crescimento & desenvolvimento , Florestas , China , Lasers , Modelos Teóricos , Árvores/crescimento & desenvolvimento
11.
Mediators Inflamm ; 2013: 570370, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24371375

RESUMO

Lidocaine, a common local anesthetic drug, has anti-inflammatory effects. It has demonstrated a protective effect in mice from septic peritonitis. However, it is unknown whether lidocaine has effects on high mobility group box 1 (HMGB1), a key mediator of inflammation. In this study, we investigated the effect of lidocaine treatment on serum HMGB1 level and HMGB1 expression in liver, lungs, kidneys, and ileum in septic rats induced by cecal ligation and puncture (CLP). We found that acute organ injury induced by CLP was mitigated by lidocaine treatment and organ function was significantly improved. The data also demonstrated that lidocaine treatment raised the survival of septic rats. Furthermore, lidocaine suppressed the level of serum HMGB1, the expression of HMGB1, and the activation of NF-κB p65 in liver, kidneys, lungs, and ileum. Taken together, these results suggest that lidocaine treatment exerts its protective effection on CLP-induced septic rats. The mechanism was relative to the inhibitory effect of lidocaine on the mRNA expression level of HMGB1 in multiple organs, release of HMGB1 to plasma, and activation of NF- κB.


Assuntos
Proteína HMGB1/antagonistas & inibidores , Lidocaína/uso terapêutico , NF-kappa B/fisiologia , Sepse/tratamento farmacológico , Animais , Proteína HMGB1/sangue , Proteína HMGB1/genética , Lidocaína/farmacologia , Masculino , Peroxidase/metabolismo , Transporte Proteico/efeitos dos fármacos , RNA Mensageiro/análise , Ratos , Ratos Wistar , Sepse/mortalidade
12.
Chin Med J (Engl) ; 122(17): 2002-7, 2009 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-19781385

RESUMO

BACKGROUND: Real-time perfusion imaging (RTPI) using ultrasound contrast agents has shown good "accuracy" in detecting myocardial infarction, however its accuracy in the assessment of peri-infarct ischemia and stress echocardiography are not known. The aim of this study was to determine the accuracy of RTPI in assessment of peri-infarct ischemia during dobutamine and adenosine stress. METHODS: We employed the RTPI modality (Agilent and ATL Philips) in a canine model (18 dogs) of distal coronary occlusion and proximal coronary stenosis. Using coronary flow probe recordings, the physiologic significance of proximal coronary stenosis was established by confirming abolition of the coronary reserve. The contrast agent Optison was given as a slow bolus injection at baseline, during prolonged distal coronary occlusion, during adenosine bolus stress and during dobutamine stress. Triphenyltetrazolium chloride (TTC) staining was used to verify a distal infarction. RTPI recordings at baseline, the distal coronary occlusion and stress protocols were randomly mixed and reviewed blindly. RESULTS: In all but one dog, RTPI detected a distal infarct as small as 9% of the left ventricle. The sensitivity, specificity and overall diagnostic accuracy of RTPI in the detection of distal infarcts were: 94%, 89% and 92%, respectively. The sensitivity, specificity, and overall diagnostic accuracy of RTPI in the assessment of peri-infarction ischemia were 83%, 92% and 88% for adenosine stress and 95%, 86% and 91% for dobutamine stress, respectively. CONCLUSIONS: Even small distal infarcts can be detected by RTPI; peri-infarct ischemia can be accurately recognized by RTPI during stress; adenosine and dobutamine stress appear equally reliable in the RTPI evaluation of peri-infarct ischemia.


Assuntos
Adenosina/toxicidade , Dobutamina/toxicidade , Ecocardiografia/métodos , Infarto do Miocárdio/diagnóstico por imagem , Animais , Circulação Coronária/efeitos dos fármacos , Cães , Feminino , Hemodinâmica/efeitos dos fármacos , Masculino
13.
Ying Yong Sheng Tai Xue Bao ; 19(2): 261-6, 2008 Feb.
Artigo em Chinês | MEDLINE | ID: mdl-18464629

RESUMO

Based on Landsat TM images and with the natural forest area of Wangqing in Jilin Province as a case, a nonlinear RS (remote sensing) modeling system of forest biomass was built by using a back-propogation artificial neural network (B-P ANN). In addition to RS data, the factors representing terrain conditions, such as elevation, slope, aspect and site type, were also included as independent variables in the modeling system. The standard B-P ANN was made more robust by reducing the size of input data and by improving the training algorithms, thereby leading to faster convergence speed and stronger capabilities of self-study and self-adaptation. The simulation results showed that the robust B-P ANN was able to utilize previous knowledge of data sets, and to automatically determine reasonable models. Model predictions of forest biomass were successful, with the mean relative errors and the mean absolute of relative errors for needle-leaved, broad-leaved, and mixed forests being -1.47%, 2.38% and 3.56%, and 6.33%, 8.46% and 8.91% , respectively. A forest biomass distribution map was derived, and the overall accuracy of the map was 88.04%.


Assuntos
Biomassa , Redes Neurais de Computação , Árvores/crescimento & desenvolvimento , China , Geografia , Modelos Teóricos , Comunicações Via Satélite
14.
Ying Yong Sheng Tai Xue Bao ; 18(1): 1-8, 2007 Jan.
Artigo em Chinês | MEDLINE | ID: mdl-17396491

RESUMO

Forest biomass estimation is the groundwork of analyzing carbon cycle and its dynamics in terrestrial ecosystems, but the current estimation models had the problem of un-compatibility between total forest biomass and its components. Taking the Wangqing natural forest area in Jilin Province as a case, the compatible concept of building forest biomass models based on forest invent' tory was brought forward. A series of compatible biomass estimation models, taking stem volume as one of the independent variables, were established by using simultaneous equations. The accuracy of the models in estimating the biomass of coniferous forest, broad-leaved forest, and mixed forest was all higher than 95% , suggesting that these models basically solved the problem of un-compatibility between total forest biomass and its components.


Assuntos
Biomassa , Conservação dos Recursos Naturais , Monitoramento Ambiental/métodos , Modelos Teóricos , Árvores/crescimento & desenvolvimento , China , Previsões , Modelos Estatísticos
15.
Chin Med J (Engl) ; 119(3): 179-84, 2006 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-16537001

RESUMO

BACKGROUND: Innovative advancements in ultrasound instrumentation present a number of imaging modalities for myocardial contrast echocardiography (MCE) in ischemic syndromes. How well they compare to each other in diagnostic accuracy in the detection of acute myocardial infarction is unclear. The purpose of this study was to assess the relative accuracy of 3 different imaging modes of MCE, low mechanical index (MI) real-time perfusion imaging (RTPI), triggered harmonic angio mode (HA), and ultraharmonic imaging mode (UH) in the detection of acute experimental myocardial infarction within the time frame suitable for potential reperfusion. METHODS: MCE was performed in 10 open-chest dogs using RTPI, triggered HA and triggered UH modes at baseline and one hour after occlusion of left anterior descending coronary artery. Presence or absence of perfusion defects, and the perfusion defect size when present, were analyzed and compared with the infarct size delineated by triphenyltetrazolium chloride (TTC) staining. RESULTS: The infarct area was (15.8 +/- 2.4)% by TTC staining; Perfusion defect area by MCE was similar to anatomic infarct area in all the three MCE approaches: (16.1 +/- 2.7)% by RTPI mode, (15.5 +/- 2.9)% by HA mode, and (15.5 +/- 3.0)% by UH mode. The sensitivity, specificity and overall diagnostic accuracy in the detection of myocardial infarction were 100%, 88%, and 94% for RTPI mode, 88%, 100%, and 94% for HA mode, and 100%, 75%, and 88% for UH mode. CONCLUSION: All modes of MCE, RTPI, triggered HA mode and triggered UH mode have excellent diagnostic accuracy in the immediate hour of acute coronary occlusion within the optimal time frame suitable for reperfusion therapy.


Assuntos
Ecocardiografia/métodos , Infarto do Miocárdio/diagnóstico por imagem , Animais , Meios de Contraste , Cães , Coloração e Rotulagem , Sais de Tetrazólio
16.
Echocardiography ; 19(8): 735-41, 2002 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-12487647

RESUMO

Epicardial coronary imaging using high frequency (7-12 MHz) ultrasound probes could aid the surgeon performing coronary artery bypass procedures by localizing the coronary artery segments underneath epicardial fat, identifying the site of coronary stenosis to be bypassed, evaluating the integrity of distal coronary artery, assessing the efficacy of anastomosis, and detecting anastomotic complications. While an ideal coronary imaging probe is yet to be developed, early clinical experience with vascular imaging probes applied on the coronary vessels suggests that epicardial coronary artery imaging could enhance the optimum performance of coronary interventions. Fabrication of a flexible high frequency probe that could be applied not only on the arteries on the anterior surface of the heart but also on the lateral and posterior surfaces could facilitate development of newer surgical procedures as well.


Assuntos
Artérias/cirurgia , Procedimentos Cirúrgicos Cardíacos , Vasos Coronários/cirurgia , Cuidados Intraoperatórios , Pericárdio/cirurgia , Artérias/diagnóstico por imagem , Vasos Coronários/diagnóstico por imagem , Ecocardiografia Doppler , Cardiopatias/diagnóstico por imagem , Cardiopatias/fisiopatologia , Cardiopatias/cirurgia , Hemodinâmica/fisiologia , Humanos , Cuidados Intraoperatórios/métodos , Pericárdio/diagnóstico por imagem
17.
Curr Cardiol Rep ; 4(1): 33-40, 2002 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11743920

RESUMO

Noninvasive cardiac imaging techniques have made a striking impact on the evaluation and management of pericardial disorders. Two-dimensional and Doppler echocardiography are the methods of choice in the evaluation of pericardial effusion and cardiac tamponade. Magnetic resonance imaging, computed tomography, and transesophageal echocardiography are valuable in the assessment of pericardial thickness in suspected cases of constrictive pericarditis. Filling dysfunction associated with constrictive pericarditis is well demonstrated by Doppler flow velocity recordings of intracardiac flow jets, and pulmonary and hepatic venous flow streams. Tissue Doppler echocardiography, by which tissue velocity of myocardial regions and mitral annulus are analyzed, offers additional information in the differentiation of constrictive pericarditis and restrictive cardiomyopathy. Magnetic resonance imaging and computed tomography are the techniques of choice in the recognition of unusual disorders such as pericardial cysts, tumors invading the pericardium, and congenital absence of pericardium. Noninvasive imaging aids not only in the diagnosis of pericardial diseases, but also in the guidance of optimal therapy.


Assuntos
Tamponamento Cardíaco/diagnóstico , Derrame Pericárdico/diagnóstico , Pericardite Constritiva/diagnóstico , Velocidade do Fluxo Sanguíneo , Tamponamento Cardíaco/fisiopatologia , Humanos , Derrame Pericárdico/fisiopatologia , Pericardite Constritiva/etiologia , Pericardite Constritiva/fisiopatologia
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