Biomedical subjects

Yue Li

Publications and source records attributed to Yue Li.

At least 37 records · Page 2Linked to original sources

PubMed2006

Beneficial effects of ApoA-I on LPS-induced acute lung injury and endotoxemia in mice.

High density lipoprotein (HDL) binds lipopolysaccharide (LPS) and neutralizes its toxicity. The aim of our study was to investigate the effects of Apolipoprotein (ApoA-I), the major apolipoprotein of HDL, on LPS-induced acute lung injury (ALI) and endotoxemia. BALB/c mice were challenged with LPS, followed by ApoA-I or saline administration for 24h. The mice were then sacrificed and histopathological analysis of the lung was performed. We found that ApoA-I could attenuate LPS-induced acute lung injury and inflammation. To investigate the mechanisms, we measured tumor necrosis factor alpha (TNF-alpha), interleukin-1beta (IL-1beta) and interleukin-6 (IL-6) levels in the serum and bronchoalveolar lavage (BAL) fluid and found that ApoA-I could significantly inhibit LPS-induced increases in the IL-1beta and TNF-alpha levels in serum (P<0.05, respectively), as well as in the IL-1beta, TNF-alpha, and IL-6 levels in BAL fluid (P<0.01 and P<0.05, P<0.05, respectively). Moreover, we evaluated the effect of ApoA-I on the mortality of L-929 cells which were attacked by LPS-activated peritoneal macrophages. We found that ApoA-I could significantly inhibit the LPS-induced cell death in a dose-dependent fashion. Furthermore, we investigated in vivo the effects of ApoA-I on the mortality rate and survival time after LPS administration and found that ApoA-I significantly decreased the mortality (P<0.05) and increased the survival time (P<0.05). In summary, the results suggest that ApoA-I could effectively protect against LPS-induced endotoxemia and acute lung damage. The mechanism might be related to inhibition of inflammatory cytokine release from macrophages.

Algorithms↗

PubMed2006

Ultrasonically induced Au nanoprisms and their size manipulation based on aging.

A simple sonochemical approach was developed for the synthesis of single-crystal Au nanoprisms with triangular or hexagonal shape, 30-40 nm planar dimension, and 6-10 nm thickness in an ethylene glycol solution. It has been shown that ethylene glycol, the surfactant poly(vinylpyrrolidone), and ultrasonic irradiation play important roles in the formation of Au nanoprisms. The subsequent aging induces the growth of Au nanoprisms, which is attributed to the existence of residual reduced Au degrees atoms and Au clusters in the solution. Further growth of Au nanoprisms could be realized by adding a given amount of HAuCl4 to the irradiated and aged Au nanodisk colloidal solution, which provides a simple and an effective method to synthesize Au nanoprisms with different sizes. Au nanoprisms with planar sizes from 70 to 400 nm have been successfully synthesized based on this strategy.

Ethylene Glycol↗

PubMed2006

Economic burden associated with Parkinson's disease on elderly Medicare beneficiaries.

We evaluated medical utilization and economic burden of self-reported Parkinson's disease (PD) on patients and society. Using the 1992-2000 Medicare Current Beneficiary Survey, we compared health care utilization and expenditures (in 2002 U.S. dollars) of Medicare subscribers with and without PD, adjusting for sociodemographic characteristics and comorbidities. PD patients used significantly more health care services of all categories and paid significantly more out of pocket for their medical services than other elderly (mean+/- SE, 5,532 dollars+/- 329 dollars vs. 2,187 dollars+/- 38 dollars; P<0.001). After adjusting for other factors, PD patients had higher annual health care expenses than beneficiaries without PD (18,528 dollars vs. 10,818 dollars; P<0.001). PD patients were more likely to use medical care (OR=3.77; 95% CI=1.44-9.88), in particular for long-term care (OR=3.80; 95% CI=3.02-4.79) and home health care (OR=2.08; 95% CI=1.76-2.46). PD is associated with a significant economic burden to patients and society. Although more research is needed to understand the relationship between PD and medical expenditures and utilization, these findings have important implications for health care providers and payers that serve PD populations.

Activities of Daily Living↗

PubMed2006

Association of HLA class II DRB1, DPA1 and DPB1 polymorphism with genetic susceptibility to idiopathic dilated cardiomyopathy in Chinese Han nationality.

Although the aetiology of idiopathic dilated cardiomyopathy (IDC) remains unclear, many immunological abnormalities involving changes in cell-mediated and humoral immunity may be associated with cardiac impairment in IDC. Autoimmune mechanisms are likely to participate in the pathogenesis of at least a subgroup of IDC and components of the major histocompatibility complex may serve as markers for the propensity to develop immune-mediated myocardial damage. Human leukocyte antigen (HLA) class II genes, which are highly polymorphic, play an important role in the activating of immune responses and thus control the predisposition for or protection from IDC. This study explores the possible contribution of HLA-DRB and DP polymorphisms to IDC susceptibility. DNA genotyping for HLA-DRB1, DPA1 and DPB1 was performed using polymerase chain reaction-sequencing based typing (PCR-SBT) method in 198 IDC patients and 136 random selected healthy Han ethnic individuals living in Northern China. IDC patients were, sub-grouped into asymptomatics (subgroup A), with arrhythmia (subgroup B) and with overt congestive heart failure (subgroup C) according to the clinical manifestations and electrocardiogram or echocardiographic characteristics. ADP/ATP autoantibody was detected in IDC group by immunoblot analysis. The results revealed that HLA-DR15, -DPB*0601 frequencies were significantly elevated in IDC group compared with normal control. The DPB1*0601 allele in homozygous form or in combination with allele DPB1*2301 or *3901, was found present more often in IDC patients. The predominance of HLA-DR4 allele was observed in subgroup B after stratification. However, the frequency of DPB1*0101 allele increased in the control than in the IDC group. The frequency of HLA-DPB1*0601 allele was significantly higher in IDC patients with positive autoantibody against ADP/ATP carrier of myocardial mitochondria in contrast to those with negative autoantibody. We conclude that HLA-DR4, -DR15, -DPB1*0601 alleles confers susceptibility to, while DPB1*0101 allele confers protection from IDC among individuals of northern Chinese Han nationality. The glutamate at position 69 in the second exon of DPB1*0601, as a key residue for special conformation of HLA-DP, may confer predisposition to IDC. HLA-DR and -DP alleles polymorphisms may serve as genetic markers for IDC and be involved in the regulation of the immune specific response to auto or exterior anti-myocardium antibodies.

Alleles↗

PubMed2006

Impact of patient volume on the mortality rate of adult intensive care unit patients.

OBJECTIVE: Expert task forces have proposed that adult critical care medicine services should be regionalized in order to improve outcomes. However, it is currently unknown if high intensive care unit (ICU) patient volumes are associated with reduced mortality rate. The objective was to investigate whether high-volume ICUs have better mortality outcomes than low-volume ICUs. DESIGN: Retrospective cohort study analyzing the association between ICU volume and in-hospital mortality using Project IMPACT (a clinical outcomes database created by the Society of Critical Care Medicine). PATIENTS: The analyses were based on 70,757 patients admitted to 92 ICUs between 2001 and 2003. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The main outcome measure was in-hospital mortality. Hierarchical logistic regression modeling was used to examine the volume-outcome association. The median (interquartile range) ICU volume was 827 (631-1,234) patient admissions per year. The overall mortality rate was 14.6%. After controlling for patient risk factors and ICU characteristics, and clustering, there was evidence that patients admitted to high-volume ICUs had improved outcomes (p = .025). However, this mortality benefit was seen only in high-risk patients treated at ICUs treating high volumes of high-risk patients. CONCLUSIONS: There is evidence that high ICU patient volumes are associated with lower mortality rates in high-risk critically ill adults.

Critical Illness↗

PubMed2006

Impact of changing the statistical methodology on hospital and surgeon ranking: the case of the New York State cardiac surgery report card.

BACKGROUND: Risk adjustment is central to the generation of health outcome report cards. It is unclear, however, whether risk adjustment should be based on standard logistic regression, fixed-effects or random-effects modeling. OBJECTIVE: The objective of this study was to determine how robust the New York State (NYS) Coronary Artery Bypass Graft (CABG) Surgery Report Card is to changes in the underlying statistical methodology. METHODS: Retrospective cohort study based on data from the NYS Cardiac Surgery Reporting System on all patient undergoing isolated CABG surgery in NYS and who were discharged between 1997 and 1999 (51,750 patients). Using the same risk factors as in the NYS models, fixed-effects and random-effects models were fitted to the NYS data. Quality outliers were identified using 1) the ratio of observed-to-expected mortality rates (O/E ratio) and confidence intervals (CIs) calculated using both parametric (Poisson distribution) and nonparametric (bootstrapping) techniques; and 2) shrinkage estimators. RESULTS: At the surgeon level, the standard logistic regression model, the fixed-effects model, and the fixed-effects component of the random-effects model demonstrated near-perfect agreement on the identity of quality outliers using a quality indicator based on the O/E ratio and the Poisson distribution. Shrinkage estimators identified the fewest outliers, whereas the O/E ratios with bootstrap CI identified the greatest number of outliers. The results were similar for hospitals, except that the fixed-effects model identified more outliers than either the NYS model or the fixed-effects component of the random-effects model. CONCLUSION: Shrinkage estimators based on random-effects models are slightly more conservative in identifying quality outliers compared with the traditional approach based on fixed-effects modeling and standard regression. Explicitly modeling surgeon provider effect (fixed-effects and random-effects models) did not significantly alter the distribution of quality outliers when compared with standard logistic regression (which does not model provider effect). Compared with the standard parametric approach, the use of a bootstrap approach to construct 95% confidence interval around the O/E ratio resulted in more providers being identified as quality outliers.

Benchmarking↗

PubMed2006

Associative learning in hierarchical self-organizing learning arrays.

In this paper, we introduce feedback-based associative learning in self-organized learning arrays (SOLAR). SOLAR structures are hierarchically organized networks of sparsely connected neurons that define their own functions and select their interconnections locally. This paper provides a description of neuron self-organization and signal processing. Feedforward processing is used to make necessary correlations and learn the input patterns. Discovered associations between neuron inputs are used to generate feedback signals. These feedback signals, when propagated to the primary inputs, can establish the expected input values. This can be used for heteroassociative (HA) and autoassociative (AA) learning and pattern recognition. Example applications in HA learning are given.

Algorithms↗

PubMed2006

Position and time-delay calibration of transducer elements in a sparse array for underwater ultrasound imaging.

This paper describes a novel method for the calibration of the position and time delay of transducer elements in a large, sparse array used for underwater, high-resolution ultrasound imaging. This method is based on the principles used in the global positioning system (GPS). However, unlike GPS, in which the wave propagation speed is generally assumed known, the sound propagation speed in the water usually is unknown and it is calibrated simultaneously in this method to achieve high calibration accuracy. In this method, a high-precision positioning system is used to scan a single hydrophone (used for transmission) in the imaging field of the array. The hydrophone transmits pulses at selected positions, and the transducer elements in the sparse array receive the transmitted signals. Time of flight (TOF) values between transducer elements and hydrophone positions then are measured. From a series of measured TOF values, the position and time delay values for each transducer element as well as the propagation speed can be calibrated. The performances of the calibration algorithm are theoretically analyzed and evaluated with numerical calculations and simulation studies. It is found that this method is capable of calibrating the positions and time delays of transducer elements with high accuracy.

Journal Article↗

PubMed2006

Measurement of light wavelength based on nanostructured ordered pore arrays.

A new method of light wavelength measurement is presented based on the nanostructured ordered pore arrays with multi-domains and centimeter square size formed by solution dipping-colloidal monolayer. Because of periodicity of the ordered pore arrays, perpendicular incidence of a parallel beam light on the array will lead to the diffraction spots or ring, depending on relative sizes of the beam and the domain in the arrays. The diffraction angle corresponds to wavelength of the incident light. On this basis, one can measure the wavelength of an incident light in transmission mode using such nanostructured ordered pore arrays, which is different from the conventional one fabricated from Michelson interference principle. Both the resolution and measurement precision can reach < 1 nm in such a simple method. Comparatively, this new measurement setup is simple in structure, low in cost, convenient in measurement, and especially, small in size. It could be used for online demarcation and real-time measurement of light wavelength in such as, mine operation, seabed exploration, and even space exploration due to its miniature.

Biophysics↗

PubMed2006

[The research on associating the single nucleotide polymorphism of CTLA-4 gene promoter region with idiopathic dilated cardiomyopathy].

OBJECTIVE: To investigate the expression of cytotoxic T lymphocyte associated antigen-4 (CTLA-4) in patients with idiopathic dilated cardiomyopathy (IDC) and to explore genetic susceptibility to IDC caused possibly by single nucleotide polymorphism (SNP) of CTLA-4 gene promoter. METHODS: PCR-restriction fragment length polymorphism techniques were used to analyze the SNPs of CTLA-4 gene at position -1772, -1661 and -318 in the promoter region. Serum sCTLA-4, IFN-gamma and IL-4 were tested by ELISA. RESULTS: sCTLA-4 levels of IDC patients were associated with the haplotype and genotype. Patients with -1772 TC genotype or -1772 TC -1661 AA, -1772 TC -1661 AG haplotypes had higher sCTLA-4 levels than patients with other haplotypes did. The frequency of -1772 TC genotype was significantly high in patients with low ejection factor(EF) values. Whereas the frequencies of -1661 G allele and -1661 GG genotype were lower in IDC patients. Levels of IL-4 were increased in IDC group. CONCLUSION: Patients with IDC have an aberrant expression of the CTLA-4 products, and the -1772 C/T and -1661 A/G polymorphisms. The two SNPs may function as genetic markers for disease susceptibility.

Antigens, CD↗

PubMed2006

[Effects of prostate water pellets on the serum levels of IL-6 and TNF-alpha in rats with chronic bacterial prostatitis].

OBJECTIVE: To investigate the effect of Prostate Water Pellets (PWP) on serum levels of IL-6 and TNF-alpha in rats with chronic bacterial prostatitis (CBP). METHODS: Fifty healthy, adult, male Wistar rats with the weight of 180 - 220 g were divided into five groups of ten rats each at random: the control group, model group, high dosage of PWP group, low dosage of PWP group and levofloxacin group. The CBP rat model were created by injecting Escherichia coli (0.2 ml/rat, 10(7)/ml) into prostates. A month later after the model creation, high and low dosage of PWP suspension were used by gavage in CBP rats for 30 days, respectively. Levofloxacin tablets were used by gavage as the positive control, and distilled water was used by gavage in the control and model group. After thirty days, serum levels of IL-6 and TNF-alpha were measured with radioimmunoassay. RESULTS: Compared with the model group, serum levels of IL-6 and TNF-alpha of rats in high and low dosage PWP groups were lower and the difference was significant statistically (P < 0.01). CONCLUSION: It has effect to treat CBP rat with the PWP and its mechanism may relate with the decreasing levels of proinflammatory cytokines(IL-6 and TNF-alpha) in blood.

Animals↗

PubMed2006

[Contrast analysis on two air fluorine content measurement methods].

OBJECTIVE: To take the two kinds of sampling and measurement methods of air fluorine content in the endemic fluorosis area to carry on the comparison, understanding their difference and inside relation. METHODS: Sampled 22 households random on the scene in the disease area with two samplers by two methods, at the position of which, at the same time, equidistance, same highness, as close as possible, but not produce interactive effect, to collect 34 of the air sample, and then gained the results by their respective methods of laboratory analysis and statistical analysis. RESULTS: The test of significance between two methods was P > 0.05, the coefficient of correlation was r = 0.7752, the test of significance was P < 0.01, the equation of linear regression between the GB method (X) and the manual method (Y) was Y = 1.1623X + 0.0008, the test of significance of coefficient of regression was P < 0.01. CONCLUSION: Two kinds of methods had no significant differences. They preset the medium degree positive correlation and a linear regression. The air fluoride in different granularity of suspended particles was not the same. The GB method was more applicable to research of synthesis damage towards the exposing crowd in burning coal fluorine, and manual method was more applicable to research of the damage resulting from the exposing crowd in burning coal fluorine through the breath system. Generally speaking, the results of the manual method was higher than the GB method.

Air Pollutants↗

PubMed2006

[IL-10 gene modification on immature dendritic cells induces antigen-specific tolerance in experimental autoimmune myocarditis].

OBJECTIVE: To investigate whether IL-10 gene modification on immature dendritic cells (iDC) could induce autoimmune tolerance in rat experimental autoimmune myocarditis (EAM). METHODS: EAM was induced by cardiac myosin immunization on day 0 and day 7 in rats. A total of 2 x 10(6) mature DC (mDC), iDC, pcDNA3 transfected iDC, pcDNA3-IL-10 transfected iDC or PBS were injected intravenously at 5th immunization day. Three weeks later, echocardiography and HE staining were performed to observe the cardiac function and myocardial inflammation. Th1/Th2 cytokines were detected by ELISA and MHC-II molecules, costimulatory molecules were identified by flow cytometry. In vitro T lymphocyte proliferation assay and adoptive transfer of DCs were performed to determine the antigen specific tolerance induced by IL-10 gene modification on iDCs. RESULTS: EAM rats treated with pcDNA3-IL-10 transfected iDC showed improved cardiac function and reduced inflammatory cells infiltration into myocardium. Moreover, lower Th1 and higher Th2-type response was induced, MHC-II and costimulatory molecules down-regulated and antigen specific immunological responses towards cardiac myosin inhibited in pcDNA3-IL-10-iDC treated EAM rats. CONCLUSION: Treatment with IL-10 gene modified iDCs could ameliorates EAM by inducing Th2 polarization and down-regulation of MHC-II molecules and costimulatory molecule expressions.

Animals↗

PubMed2006

[Changes in the calcitonin content after inhalation injury in dogs].

OBJECTIVE: To investigate the changes in the serum content of immunoreactive calcitonin (iCT) after burns or inhalation injury, and to explore its diagnostic significance. METHODS: Twenty-four dogs were randomized into 4 groups, i. e. A (n = 6, with moderate degree inhalation injury) , B ( n = 6, with severe inhalation injury), C (n = 6, with most severe inhalation injury) and D (n = 6, with severe burns) groups. The serum content of iCT and blood gas analysis before and after injury were determined at different time points. The degree of inhalation injury was determined with fibrobronchoscopic examination at 6 post-inhalation injury hour (PIH). RESULTS: (1) Fiber bronchoscopic examination showed that the degree of inhalation injury in each group was coincident with the anticipation. (2) The serum content of iCT in each group at 1 PIH was obviously higher than that before injury, and it was evidently higher in A, B and C groups than that in D group at 4 PIH. The peak value of iCT in group A at 24 PIH was (453+/-224) ng/L, and it increased gradually in B and C groups at 48 PIH. The serum content of iCT increased continually from 2 PIH on, and it reached (125+/-41) ng/L at 48 PIH. (3) Compared with PaO2 value before injury (109+/-8) mmHg, there was no obvious difference of the PaO, in A and D groups. PaO2 value in B and C group began to descend continually at 8 PIH (65+/-6) mmHg, and that in C group began to descend at 4 PIH (71+/-9) mmHg. PaCO2 value in C group began to increase at 24 PIH(52+/-11) mmHg when compared with that before injury(38+/-5 ) mmHg. CONCLUSION: The changes in the serum level of iCT within 8 PIH occurred much earlier than PaO2 and PaCO2, thus it has the same diagnostic significance as fibers bronchoscopic examination.

Animals↗

PubMed2005

Bi-directional regulation of emodin and quercetin on smooth muscle myosin of gizzard.

This study is to reveal the characteristics of bidirectional regulation of emodin (1,3,8-trihydroxy-6-methyl-anthraquinone) and quercetin on gizzard smooth muscle myosin. Our results indicate that: (a) emodin demonstrates stimulatory effects, and quercetin produces inhibitory effects on myosin phosphorylation and Mg(2+)-ATPase activities of Ca(2+)/calmodulin-dependent phosphorylated myosin in a dose-dependent manner; (b) a combination of emodin and quercetin enhances phosphorylation and Mg(2+)-ATPase activities for partially phosphorylated myosin and inhibits those activities for fully phosphorylated myosin; (c) 1-(5-Chloronaphthalene-1-sulfonyl)-1H2-hexahydro-1,4-diazepine inhibits myosin phosphorylation in the presence of emodin and/or quercetin. A combination of emodin and quercetin indicates its potential for modulating gastric-intestinal smooth muscle.

Animals↗

PubMed2005

Kyotorphin has a novel action on rat cardiac muscle.

Several endogenous peptides for G-protein-coupled receptors have been found to play physiological roles in muscle contraction in addition to their well-demonstrated actions in other tissues. To further identify such peptides, we screened over 400 peptides using an isometric tension assay of rat papillary muscle. Here, we report that kyotorphin, which is known as an analgesic dipeptide, has a cardiac effect. Although kyotorphin had no effect on the twitch tension itself, it inhibited beta-adrenergic agonist isoprenaline-induced increases in twitch tension in a dose-dependent manner. Leu-Arg, a selective antagonist of kyotorphin, reversed this inhibitory effect. The inhibitory effect was also reversed by naloxone, an opioid receptor antagonist. These results suggest that kyotorphin may release opioid peptides from rat cardiac muscle and have an indirect regulatory role in beta-adrenergic action through cross-talk with opioid receptors.

Animals↗

PubMed2005

Downregulation of MDM2 expression by RNAi inhibits LoVo human colorectal adenocarcinoma cells growth and the treatment of LoVo cells with mdm2siRNA3 enhances the sensitivity to cisplatin.

To investigate the biological effect of mdm2 in human colorectal adenocarcinoma LoVo cells, three mdm2siRNA constructions were recombined and transient transfected into human colorectal adenocarcinoma LoVo cells with low differentiation character in vitro. The results showed that mdm2siRNA3 reduced mRNA level of mdm2 and protein level of mdm2, leading to proliferation inhibition on LoVo cells, and reduced tumor growth in nude mice. It was found that depletion of MDM2 in this pattern promoted apoptosis of LoVo cells and Cisplatin (DDP) treated in the mdm2siRNA3 transfected cell population would result in a substantial decrease by MTT colorimetry. Decreasing the MDM2 protein level in LoVo cells by RNAi could significantly inhibit tumor growth both in vitro and in vivo, which indicated that mdm2 gene played a definite role in the development and aggressiveness of human colon carcinoma. It also could be a therapeutic target in colorectal carcinoma. The synergistic activation of RNAi and cell toxicity agents indicated that the combination of chemotherapy and gene therapy will be a promising approach in the future.

Adenocarcinoma↗

PubMed2005

Treatment of organophosphate-contaminated wastewater by acidic hydrolysis and precipitation.

Wastewater from commercial manufacture of organophosphate (OP) pesticide of O-methyl-O-(2-isopropyl salicylate) thiophosphorusyl amide contains large amounts of organophosphate, organic sulfides, COD and NH3-N. A treatment process including acidic hydrolysis and precipitation was explored in this paper. The effects of initial pH values, hydrolysis temperature and hydrolysis time on the removal of pollutants were investigated. The experimental results showed that, in the hydrolysis, with the decreasing initial pH value, the removal of OP, sulfide and COD rose whereas the NH3-N removal declined. Increased hydrolysis temperature and time favored the removal of all the pollutants. 15.0 wt% Ca(OH)2 was sufficient for the removal of inorganic phosphorus and residual NH3-N in the precipitation step. With this chemical process, the removal of total phosphorus (TP), organophosphate, sulfides and NH3-N exceeded 90%, and the removal of COD was about 60%. The BOD5/COD value was greatly improved from 0.05 to 0.3, and the bio-degradability of the wastewater was greatly improved. The NH3 generated in the process was absorbed with water and might be reused in the manufacture of the pesticide. The results showed that this comprehensive process is effective for the treatment of this typical unbio-degradable pesticide wastewater.

Chemical Precipitation↗