Biomedical subjects

L Yang

Publications and source records attributed to L Yang.

At least 37 records · Page 2Linked to original sources

PubMed2005

Epidemiological profile of mortality due to injuries in three cities in the Guangxi Province, China.

This study aimed to provide epidemiological information on injury mortality in three major cities in Guangxi Province of South Western China. This was a population-based descriptive study utilising surveillance and field-gathered data. Data were obtained from the disease surveillance information system and record on each death certificate. Mortality rates were compared between sex and among different age groups for different causes of injury. Regression modelling was applied to examine for any increasing trend of injury mortality within the study period. Drowning was a severe problem for boys and girls younger than 5 years. Among all estimated mortality rates (per 100,000 person-years) for all sex, age groups, and categories of death, they were the highest with a rate of 29.8 (95%CI = 16.7-42.9) for boys and 29.6 (95%CI = 15.9-43.3) for girls. The overall mortality rates of motor vehicle and other transport-related injury was also similar to those developed countries. There was a marginally significant trend of increasing injury mortality within the study period.

Accidental Falls↗

PubMed2005

Different quantitative measures of the impact of injury deaths on the community in the Guangxi Province, China.

BACKGROUND: Injury has been identified as a major health problem in China. Different quantitative measures based on the concept of years of potential life lost have been derived for assessing the burden of injury and other diseases. However, few studies have been conducted to compare the usefulness of these measures in terms of providing practical information. This study aims to examine the utility of different measures in assessing the impact of injury to Chinese society. METHODS: This is a population-based epidemiological study utilising surveillance and fielded-gathered data. Data are obtained from the disease surveillance information system and record on each death certificate. The mortality rates, years of potential life lost (YPLL), potentially years of productive life lost (PYPLL), and the valued years of potential life lost (VYPLL) are calculated and compared for deaths due to injury and other major diseases. Data on different causes of injury were analysed in the same manner. RESULTS: In comparison to other causes of death, injury deaths had the highest annual rates of YPLL (1265.1 years/100,000 persons), PYPLL (517.8 years/100,000 persons), and VYPLL (378.6 years/100,000 persons). Premature deaths due to injury provided the only positively valued VYPLL among all major causes of death. Among the injury deaths, motor vehicle traffic-related death caused the largest YPLL (13,274 years), PYPLL (5461 years), and VYPLL (3064 years). CONCLUSION: In considering the burden of deaths to society, mortality rate only is an insufficient measure. The age, the years of overall life and expected productivity and related economic consequences have to be taken into consideration. As an indicator of the economic impact and burden of premature deaths to society, the VYPLL seems to be an advantageous utility. Injury posts the greatest public health problem to the developing economy of China.

Accidents, Traffic↗

PubMed2005

Angiopoietin-like-4 is a potential angiogenic mediator in arthritis.

Our previous studies of gene expression profiling during collagen-induced arthritis (CIA) indicated that the putative angiogenic factor Angptl4 was one of the most highly expressed mRNAs early in disease. To investigate the potential involvement of Angptl4 in CIA pathogenesis, Angptl4 protein levels were assessed at early stages of disease and its cellular sources were determined. In addition, the functional effects of mouse Angptl4 on endothelial cells were assessed. Angptl4 protein levels were higher in arthritic joints as compared to normal joints. In situ hybridization localized Angptl4 mRNA to stromal fibroblast-like cells within the inflamed synovium. Temporal expression of Angptl4 mRNA during CIA was similar to that of key angiogenic factors, including structurally related angiopoietin 1. Recombinant mouse Angptl4 promoted endothelial cell survival and formation of tubule-like structures. These functional effects of Angptl4, combined with very high expression at early stages of CIA, suggest a role for Angptl4 in angiogenesis in arthritis.

Angiopoietin-1↗

PubMed2005

The histone deacetylase inhibitor valproic acid alters sensitivity towards all trans retinoic acid in acute myeloblastic leukemia cells.

Acute myeloblastic leukemia (AML) may be classified in a number of ways. Using the French American British classification, the M3 form of the disease or acute promyelocytic leukemia (APL) has been found to be sensitive in vitro and in vivo to the retinoid all trans retinoic acid (ATRA). The mechanism for this is by restoration of normal gene expression through the release of histone deacetylase complexes (HDACs). In contrast to APL, other forms of AML are either nonresponsive or show blunted responses to ATRA. We evaluated if the inhibitor of HDAC activity, valproic acid (VPA), could mimic or enhance retinoid sensitivity in the AML cell line, OCI/AML-2, and clinical samples derived from patients with AML. An Affymetrix GeneChip experiment demonstrated that VPA modulated the expression of numerous genes in OCI/AML-2 cells that were not affected by ATRA including p21, a retinoid responsive gene in APL. VPA induced p21 expression in OCI/AML-2 cells and the majority of the AML samples tested; this was associated with cell cycle arrest and apoptosis not seen with ATRA alone. The addition of ATRA to VPA accentuated many of these responses, supporting the potential beneficial combination of these drugs in the treatment of AML.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed2005

Statistics on cancer in China: cancer registration in 2002.

The objective of this study was to determine how many population-based cancer registries exist in China, what methods are being used, and the statistical data that are available from them, and to identify future needs with respect to technical support. A two-stage survey was conducted in 2002 at provincial and cancer registry level. Based on the questionnaire used in these two stages, the basic distribution and descriptive information on population-based cancer registry practices in China are addressed. There are 48 cancer registries in China, covering 73 million people (5.7% of the total population of China in 2000). The oldest three registries are LinZhou, ShangHai and QiDong. There are marked variations in practice between registries, with respect to data collection, data management and coding. Differences are also found in administrative aspects and sources of financial support. In conclusion, this first national survey of Chinese cancer registry practice provides a benchmark against which development and standardization can be evaluated in the future. The survey suggests that lack of qualified personnel, insufficient funding support and lack of stability of the population are major problems in carrying out registration work in China. It also indicates several ways in which registry practice, and hence availability and quality of incidence and survival data can be improved.

Benchmarking↗

PubMed2005

Stability of lyophilized and reconstituted plasma/albumin-free recombinant human factor VIII (ADVATE rAHF-PFM).

Traditionally the serum protein albumin has been used to stabilize lyophilized recombinant factor VIII (rFVIII) products. Advanced rFVIII products have now been developed that employ other stabilizers. ADVATE antihaemophilic factor (recombinant), plasma/albumin-free method (rAHF-PFM) utilizes trehalose and mannitol as stabilizers in the lyophilized preparation. An extensive in vitro evaluation was conducted on the stability of rAHF-PFM as measured by retained activity over time. Both lyophilized and reconstituted rAHF-PFM were analysed, and the full range of available potencies were tested under varying temperature conditions. Lyophilized rAHF-PFM exhibited a high degree of stability under a range of conditions. The mean retained activity of 15 rAHF-PFM lots (ranging from low to maximal potency) at 5 degrees C for 30 months was 91.6% (95% CI, 88.9-94.3%) of initial potency. rAHF-PFM also remained highly stable after storage at room temperature for 18 months, with 82.0% (95% CI, 79.2-84.9%) of initial activity retained at 25 degrees C and 79.1% (95% CI, 76.2-81.9%) at 30 degrees C. All other parameters, including moisture, appearance, solubility, pH and aggregation remained within the established product specifications. The mean retained activity after 1 month of storage at 40 degrees C was 94.0% (95% CI, 92.4-95.6%). A high temperature excursion to 40 degrees C for 2 weeks did not compromise subsequent stability of the lyophilized powder either under refrigeration or at room temperature. Reconstituted samples from 11 rAHF-PFM lots retained an average of 92.0% (95% CI, 89.8-94.3%) activity after 24 h. The present study provides evidence of good stability at differing temperatures of an albumin-free formulated rFVIII product.

Chemistry, Pharmaceutical↗

PubMed2005

Enhancement of ionic conductivity of PEO based polymer electrolyte by the addition of nanosize ceramic powders.

The ionic conductivity of polyethylene oxide (PEO) based solid polymer electrolytes (SPEs) has been improved by the addition of nanosize ceramic powders (TiO2 and AL2O3). The PEO based solid polymer electrolytes were prepared by the solution-casting method. Electrochemical measurement shows that the 10 wt% TiO2 PEO-LiClO4 polymer electrolyte has the best ionic conductivity (about 10(-4) S cm(-1) at 40-60 degrees C). The lithium transference number of the 10 wt% TiO2 PEO-LiClO4 polymer electrolyte was measured to be 0.47, which is much higher than that of bare PEO polymer electrolyte. Ac impedance testing shows that the interface resistance of ceramic-added PEO polymer electrolyte is stable. Linear sweep voltammetry measurement shows that the PEO polymer electrolytes are electrochemically stable in the voltage range of 2.0-5.0 V versus a Li/Li+ reference electrode.

Aluminum Oxide↗

PubMed2005

Techniques for improving stability in oblique fractures treated by circular fixation with particular reference to the sagittal plane.

Biomechanical studies involving all-wire and hybrid types of circular frame have shown that oblique tibial fractures remain unstable when they are loaded. We have assessed a range of techniques for enhancing the fixation of these fractures. Eight models were constructed using Sawbones tibiae and standard Sheffield ring fixators, to which six additional fixation techniques were applied sequentially. The major component of displacement was shear along the obliquity of the fracture. This was the most sensitive to any change in the method of fixation. All additional fixation systems were found to reduce shear movement significantly, the most effective being push-pull wires and arched wires with a three-hole bend. Less effective systems included an additional half pin and arched wires with a shallower arc. Angled pins were more effective at reducing shear than transverse pins. The choice of additional fixation should be made after consideration of both the amount of stability required and the practicalities of applying the method to a particular fracture.

Biomechanical Phenomena↗

PubMed2005

Treatments of oil-refinery and steel-mill wastewaters by mesocosm constructed wetland systems.

In this study, two types of industrial wastewater, oil-refining and steel-milling, were selected for investigating their feasibility of treatment by mesocosm constructed wetland systems. The secondly treated effluents from the wastewater treatment plants were directly discharged into the systems controlled at different flow rates. Three wetland mesocosms were installed in the two industries: mesocosms A and B were in the oil refinery, and mesocosm C was in the steel mill. The substratum media used in wetland systems were sand (mesocosm A) and gravel (mesocosms B and C), while the vegetation types selected were reeds (mesocosms A and B) and mixed species of reeds and cattails (mesocosm C). The flow regimes were controlled as free water surface (FWS) and subsurface flow (SSF) for the sand- and gravel-beds, respectively. According to the experimental results, we found that the system treating oil-refining wastewater performed better than that treating steel-milling wastewater learned by comparing the removal efficiencies of COD, total N and total P. In addition, it was found that for oil-refining wastewater treatments, the SSF wetland system (mesocosm B) performed better than FWS (mesocosm A) wetland system when comparing both of their removal of pollutants and growth of vegetation. Besides, the effluents from these two industrial wetland treatment systems might be reclaimed and reused for boiler water, cooling, cleaning and miscellaneous purposes in industries. Further treatments are required if the constructed wetland effluents are thought about being reused for processing in industries.

Ecosystem↗

PubMed2005

Relevance of ventricular electrical dispersion to arrhythmogenesis in ischemic myocardium--a simulation study.

A computer simulation method was used to study the possible role of electrical dispersion induced by regional ischemia in the mechanisms underlying cardiac arrhythmias. Ischemic cells were simulated by considering the three major component conditions of acute ischemia (elevated extracellular K+ concentration, acidosis and anoxia) at the level of ionic currents and ionic concentrations. An ischemic area was introduced into a homogeneous healthy tissue to create a localized inhomogeneity. The constructed models were solved using the operator splitting and adaptive time step methods. The numerical experiments showed that action potential durations (APDs) of ischemic cells did not change with beats of shorter or longer cycle length. The smaller percentage increase of slow component of the delayed rectifier K+ current, I(ks), and smaller outward Na+-Ca2+ exchange current were found to be the ionic mechanisms underlying the decreased rate dependence in ischemic cells. The results suggest that ischemia flattens the APD restitution curve; however, the dispersion of refractory period can be greatly increased by a premature beat in the constructed inhomogeneous sheet. This demonstrates that the dispersion of refractoriness rather than APD by a premature beat contributes to reentrant tachyarrhythmias in the locally ischemic tissue.

Action Potentials↗

PubMed2004

Decay of intestinal enterococci concentrations in high-energy estuarine and coastal waters: towards real-time T90 values for modelling faecal indicators in recreational waters.

Intestinal enterococci are the principal 'health-evidence-based' parameter recommended by WHO for the assessment of marine recreational water compliance. Understanding the survival characteristics of these organisms in nearshore waters is central to public health protection using robust modelling to effect real-time prediction of water quality at recreation sites as recently suggested by WHO and the Commission of the European Communities Previous models have more often focused on the coliform parameters and assumed two static day-time and night-time T90 values to characterise the decay process. The principal driver for enterococci survival is the received dose of irradiance from sunlight. In the water column, transmission of irradiance is determined by turbidity produced by suspended material. This paper reports the results of irradiated microcosm experiments using simulated sunlight to investigate the decay of intestinal enterococci in relatively turbid estuarine and coastal waters collected from the Severn Estuary and Bristol Channel, UK. High-turbidity estuarine waters produced a T90 value of 39.5 h. Low-turbidity coastal waters produced a much shorter T90 value of 6.6 h. In experiments receiving no irradiation, high-turbidity estuarine waters also produced a longer T90 of 65.1 h compared with corresponding low-turbidity coastal waters, T90 24.8 h. Irradiated T90 values were correlated with salinity, turbidity and suspended solids (r>0.8, p<0.001). The results suggest that enterococci decay in irradiated experiments with turbidity >200 NTU is similar to decay observed under dark conditions. Most significantly, these results suggest that modelling turbidity and or suspended solids offers a potential means of predicting T90 values in 'real-time' for discrete cells of a hydrodynamic model.

Dose-Response Relationship, Radiation↗

PubMed2004

CYP3A variation and the evolution of salt-sensitivity variants.

Members of the cytochrome P450 3A subfamily catalyze the metabolism of endogenous substrates, environmental carcinogens, and clinically important exogenous compounds, such as prescription drugs and therapeutic agents. In particular, the CYP3A4 and CYP3A5 genes play an especially important role in pharmacogenetics, since they metabolize >50% of the drugs on the market. However, known genetic variants at these two loci are not sufficient to account for the observed phenotypic variability in drug response. We used a comparative genomics approach to identify conserved coding and noncoding regions at these genes and resequenced them in three ethnically diverse human populations. We show that remarkable interpopulation differences exist with regard to frequency spectrum and haplotype structure. The non-African samples are characterized by a marked excess of rare variants and the presence of a homogeneous group of long-range haplotypes at high frequency. The CYP3A5*1/*3 polymorphism, which is likely to influence salt and water retention and risk for salt-sensitive hypertension, was genotyped in >1,000 individuals from 52 worldwide population samples. The results reveal an unusual geographic pattern whereby the CYP3A5*3 frequency shows extreme variation across human populations and is significantly correlated with distance from the equator. Furthermore, we show that an unlinked variant, AGT M235T, previously implicated in hypertension and pre-eclampsia, exhibits a similar geographic distribution and is significantly correlated in frequency with CYP3A5*1/*3. Taken together, these results suggest that variants that influence salt homeostasis were the targets of a shared selective pressure that resulted from an environmental variable correlated with latitude.

Black or African American↗

PubMed2004

Analysis of transcripts that are differentially expressed in three sectors of the rice root system under water deficit.

Short periods of water deprivation can stimulate the growth of seminal and lateral roots in rice, and inhibit the emergence of adventitious roots. Identification of genes in the different tissues that respond to a water deficit may help us to understand the mechanism underlying root growth under conditions when water is scarce. cDNA-amplified fragment length polymorphism (AFLP) analysis was used to profile gene expression upon imposition of water deficit in three types of root tissue from the upland rice variety Azucena: seminal root tips, lateral root zones and adventitious root primordial zones. In all, 121 unique transcript-derived fragments (TDFs) were cloned, and Northern analysis was carried out for 30 TDFs to confirm their expression patterns. Sixty-six TDFs were differentially expressed in all three root samples. Four (AC2, D6, L22 and T23) were up-regulated by water deficit in seminal root tips and lateral root zones, and down-regulated in adventitious root primordial zones, an expression pattern which reflects the phenotypic changes observed in the different root sectors. In contrast, T17 and T37 showed the opposite expression pattern in Azucena: up-regulation in adventitious roots and repression in the other two zones. Functions could be assigned to five of these six TDFs on the basis of homology: they encode an expansin (T37), a fruit-ripening protein similar to ASR (T23), submergence-induced protein 2A (T17), a dehydrin (D6) and a 9- cis -epoxycarotenoid dioxygenase1 (L22), respectively. AC2 did not show a significant match to any known gene. Northern analysis showed that these six clones exhibited expression patterns that differed between the two cultivars tested (Azucena and the lowland variety IR1552) with respect to regulation by water limitation. Furthermore, T17, T37, D6 and T23 mapped within intervals known to contain QTLs (quantitative trait loci) for root growth in rice under water deficit. These genes may regulate or co-regulate the growth and development of the three root zones in a tissue-specific manner, and may play a role in the processes that underlie the early changes in root architecture under conditions of water deprivation.

Blotting, Northern↗

PubMed2004

Quantum confinement and electronic properties of silicon nanowires.

We investigate the structural, electronic, and optical properties of hydrogen-passivated silicon nanowires along [110] and [111] directions with diameter d up to 4.2 nm from first principles. The size and orientation dependence of the band gap is investigated and the local-density gap is corrected with the GW approximation. Quantum confinement becomes significant for d<2.2 nm, where the dielectric function exhibits strong anisotropy and new low-energy absorption peaks start to appear in the imaginary part of the dielectric function for polarization along the wire axis.

Journal Article↗

PubMed2004

Estimation and projection of the national profile of cancer mortality in China: 1991-2005.

There are no national-level data on cancer mortality in China since two surveys in 1973-1975 and 1990-1992 (a 10% sample), but ongoing surveillance systems, based on nonrandom selected populations, give an indication as to the trends for major cancers. Based on a log-linear regression model with Poisson errors, the annual rates of change for 10 cancers and all other cancers combined, by age, sex and urban/rural residence were estimated from the data of the surveillance system of the Center for Health Information and Statistics, covering about 10% of the national population. These rates of change were applied to the survey data of 1990-1992 to estimate national mortality in the year 2000, and to make projections for 2005. Mortality rates for all cancers combined, adjusted for age, are predicted to change little between 1991 and 2005 (-0.8% in men and +2.5% in women), but population growth and ageing will result in an increasing number of deaths, from 1.2 to 1.8 million. The largest predicted increases are for the numbers of female breast (+155.4%) and lung cancers (+112.1% in men, +153.5% in women). For these two sites, mortality rates will almost double. Cancer will make an increasing contribution to the burden of diseases in China in the 21st century. The marked increases in risk of cancers of the lung, female breast and large bowel indicate priorities for prevention and control. The increasing trends in young age groups for cancers of the cervix, lung and female breast suggest that their predicted increases may be underestimated, and that more attention should be paid to strategies for their prevention and control.

Adolescent↗

PubMed2004

Non-steroidal anti-inflammatory drugs decrease the quality of pleurodesis after mechanical pleural abrasion.

OBJECTIVE: Non-steroidal anti-inflammatory drugs (NSAIDs) are often applied for pain management after thoracic surgery. Since these drugs diminish collagen deposition through inhibition of the prostaglandin synthesis, we investigated their effects on adhesion formation after endoscopic mechanical pleural abrasion, which is often applied in the therapy of pneumothorax. METHODS: Mechanical pleural abrasion was performed unilaterally by the use of video-assisted thoracoscopic surgery technique in an established pig model. Ten animals (41.3+/-3.4 kg) were divided into a treatment group and a control group. In the treatment group, animals received 100 mg diclofenac (2 mg/kg body weight) orally daily for 3 weeks after surgery. At 3 weeks, all animals were sacrificed and efficacy of pleurodesis was macroscopically assessed by three independent reviewers blinded to the treatment of animals using a five-point severity pleurodesis score (from 0, no adhesions to 4, complete symphisis) and obliteration grade rating the distribution of adhesions (from 0, no adhesions to 4, adhesions in the whole chest). Microscopic evaluation was performed by two pathologists blinded to the study groups as well. A four-point score assessed the amount of collagen deposition (from 1, a few collagen fibers to 4, scar). RESULTS: Gross observation showed more dense adhesions in control animals with a median pleurodesis score of 3.67+/-1.0 in comparison to 2+/-2.2 in the treatment group (P = 0.01 *, Mann-Whitney non-parametric test). Distribution of adhesions was comparable in both groups with a median obliteration score of 3.67+/-1.3. Histopathologic examination showed a higher amount of collagen deposition in the control group, suggesting more dense adhesions, whereas in the treatment group there was loose granulation tissue (score of 4.0+/-0.8 vs. 2.3+/-1.0 in the treatment group, P = 0.06). The degree of inflammatory reaction was comparable in the two groups. CONCLUSIONS: Our results demonstrate that perioperative use of NSAIDs highly affects the quality of pleural adhesions obtained after mechanical abrasion in this pig model, which further suggests that these drugs should be avoided for pain management when a pleurodesis is performed.

Animals↗

PubMed2004

Protective effect of vitamin E against focal brain ischemia and neuronal death through induction of target genes of hypoxia-inducible factor-1.

Vitamin E has been shown to have protective effects against cerebral ischemia, possibly due to its anti-oxidant effects. However, its non-anti-oxidant, intracellular molecular mechanism remains elusive. For in vivo experiments in rats, orally administered vitamin E significantly reduced not only the brain infarct volume but also space navigation disability after permanent middle cerebral artery (MCA) occlusion. The level of anti-oxidant after MCA occlusion was significantly increased specifically in the ipsilateral brain tissues of vitamin E-treated rats. For in vitro experiments, posttreatment with vitamin E protected primary cultured neurons from nitric oxide-induced insult. Vitamin E induced the expression of the alpha subunit of hypoxia-inducible factor-1 (HIF-1) and its target genes, including vascular endothelial growth factor (VEGF) and heme oxygenase-1. The hypoxia response element on the VEGF promoter was responsible for this vitamin E-induced transcriptional activation of VEGF gene. Taken together, these results suggest that cerebral infarction increased the permeability of vitamin E across the blood-brain barrier, and this increased vitamin E in brain tissue elicited neuroprotective effects not only through scavenging oxidants, as are previously well reported, but also by transactivating HIF-1-dependent genes, which results in protection of brains from ischemic insults.

Animals↗

PubMed2004

Molecular basis of transferrin polymorphism in goldfish (Carassius auratus).

Transferrin (TF) polymorphism was investigated in a color variety of goldfish (Carassius auratus), and its molecular basis analyzed. Three TF variants (A1, A2 and B1) were identified from an inbred strain of the goldfish, of which A1 and B1 displayed a large electrophoretic difference on both native and SDS-PAGE gels. The TF cDNAs corresponding to variants A1 and B1 were cloned and sequenced from A1A1, A1B1 and B1B1 individuals, and their deduced amino acid sequences were analyzed. Substantial amino acid variation occurred between variants A1 and B1, with significant differences in peptide length, theoretical molecular weight (Mw) and isoelectric point (pI). No potential glycosylation sites were observed in the two amino acid sequences, which excluded the possibility that carbohydrate difference might cause electrophoretic variation among the TF variants. Further analysis suggested that the distinct electrophoretic mobility of the two variants A1 and B1 by SDS-PAGE resulted from their Mw difference, while the difference by the native PAGE could be explained by their pI variation. Furthermore, genomic DNA fragments containing the transferrin alleles were amplified and subjected to RFLP analysis in A1A1, A1B1 and B1B1 individuals. The data revealed characteristic banding patterns for each TF genotype, and demonstrated that the TF alleles A1 and B1 could be used as a co-dominant marker system. The initial work relating to the goldfish TF variants will benefit the understanding of the evolutionary and functional significance of TF polymorphism in fish.

Amino Acid Sequence↗