Biomedical subjects

Xiaorong Wang

Publications and source records attributed to Xiaorong Wang.

At least 19 recordsLinked to original sources

PubMed2006

Toxicity of HC Orange No. 1 to Daphnia magna, zebrafish (Brachydanio rerio) embryos, and goldfish (Carassius auratus).

HC Orange No. 1 (HCO1; 2-nitro-4'-hydroxydiphenylamine) (CAS No. 54381-08-7) is used as a color additive in hair dyes and can be released into aquatic environments in wastewater. In this paper, the effects of HCO1 on aquatic organisms were studied using a battery of toxicological tests. These included measuring immobilization of Daphnia magna, inhibition of zebrafish embryo development, and acute lethality in zebrafish and goldfish, which are different species belonging to different trophic levels. HCO1 was toxic to all of the organisms studied. In our experiments, HCO1 remarkably restrained the mobility of D. magna, which may cause subsequent death. The EC50 value for restrained the mobility of D. magna at 48 h was 1.54 mg HCO1 l(-1). In addition, HCO1 showed toxicity in zebrafish and goldfish, where LC50 values at 96 h were 4.04 and 5.37 mg l(-1), respectively. The results also indicated that HCO1 remarkably retarded the development of zebrafish embryos, which may cause embryo abnormality and even lethality. The most sensitive toxicological endpoint in the development of the embryos was failure to hatch, which had an EC50 of 0.19 mg HCO1 l(-1). These results indicated that HCO1 is a potential teratogen to zebrafish embryos. In addition, as HCO1 concentrations increased, the outcomes of each of these toxicity tests changed in a concentration-dependent manner. Together, the results revealed that HCO1 appears to be toxic to multiple different species of aquatic organisms. The EC50 (LC50) values contain sufficient discriminatory power for risk assessment of HCO1 in aquatic environments. Based on the present results, more efficient risk assessment procedures for HCO1 will be designed in the future, integrating more flexible testing methods into the testing schemes that employ only the necessary tools for each case.

Animals↗

PubMed2006

Quantitative structure activity relationship (QSAR) for toxicity of chlorophenols on L929 cells in vitro.

Quantitative structure activity relationship (QSAR) were developed to predict toxicity of chlorophenols by correlating LC50 values with five molecular descriptors, chosen to represent lipophilic, electronic and steric effects: the n-octanol/water partition coefficient (log K(ow)), the constant of Hammett (sigma sigma), the acid dissociation constant (pKa), the order valence molecular connectivity index (1chi(v)) and the perimeter of the efficacious section (sigma D(g)). The results of the regression analysis showed that log K(ow) and sigma D(g) are the dominant (canonical) predictive factors in determining toxicity of chlorophenols to the cells during 24 h exposures, while log K(ow) was the only dominant predictive factor contributing to toxicity during in 48 h exposures. Comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA) were applied to investigate predictive relationships of the cytotoxicity of chlorophenols and develop visual 3D-QSAR models. The CoMFA model, in which the contribution of the electrostatic field to the biological activity was greater than that of the steric field, exhibited both high consistency and predictability (r2 = 0.968, Q2 = 0.891 for 24 h exposure; but the relationship was poorer for the 48 h exposure: r2 = 0.727, Q2 = 0.394). The CoMSIA model used in this study contained three fields: electrostatic, hydrophobic and steric, of which the relative contribution to the biological activity was 0.767:0.225:0.008. In addition, according to the models for 24 h and 48 h. The time-dependent toxicity and potential mechanisms for inhibition of L929 cells was discussed.

Animals↗

PubMed2006

Impact of exotic and inherent dissolved organic matter on sorption of phenanthrene by soils.

The impacts of exotic and inherent dissolved organic matter (DOM) on phenanthrene sorption by six zonal soils of China, chosen so as to have different soil organic carbon (SOC) contents, were investigated using a batch technique. The exotic DOM was extracted from straw waste. In all cases, the sorption of phenanthrene by soils could be well described by the linear equation. The presence of inherent DOM in soils was found to impede phenanthrene sorption, since the apparent distribution coefficients (K(d)(*)) for phenanthrene sorption by deionized water-eluted soils were 3.13-21.5% larger than the distribution coefficients (K(d)) by control soils. Moreover, the enhanced sorption of phenanthrene by eluted versus control soils was in positive correlation with SOC contents. On the other hand, it was observed that the influence of exotic DOM on phenanthrene sorption was related to DOM concentrations. The K(d)(*) values for sorption of phenanthrene in the presence of exotic DOM increased first and decreased thereafter with increasing the added DOM concentrations (0-106mgDOC/L). The K(d)(*) values at a low exotic DOM concentration (< or =28mgDOC/L) were 14.7-48.4% larger than their control K(d) values. In contrast, higher concentrations (> or =52mgDOC/L) of added exotic DOM clearly impeded the distribution of phenanthrene between soil and water. The effects of exotic and inherent DOM on phenanthrene sorption by soils may primarily be described as 'cumulative sorption', association of phenanthene with DOM in solution, and modified surface nature of soil solids due to DOM binding.

Adsorption↗

PubMed2006

Protective effect of flavonoids from Scutellaria baicalensis Georgi on cerebral ischemia injury.

The protective effect of flavonoids extracted from Scutellaria baicalensis Georgi on cerebral ischemia injury has been explored in experimental animals. Scutellaria flavonoid (SF) could significantly prolong gasping time (prolonged ratio, 23.79%) and survival time after carotid artery occlusion, and decrease attenuate malondialdehyde (MDA) content in damaged brain tissues from 118.56+/-47.95 nmol/g in untreated to 199.29+/-24.24 nmol/g. SF could also increase the content of superoxide dismutase (SOD) in brain tissues after ischemic mice from 1486+/-94 NU/g in untreated to 1168+/-76 NU/g, and showed significant protective effect on cerebral hypoxia and reperfusion brain tissues in middle cerebral artery occlusion (MCAO) procedure. Additionally, SF has inhibitory effect on platelet aggregation, with the average inhibition rate of 45.52%, while the aspirin group was 54.96%. These results suggest that SF has a significant protective effect on cerebral ischemia and ischemia-reperfusion induced brain injury.

Animals↗

PubMed2006

Matrix-bound phosphine in Antarctic biosphere.

Phosphine (PH(3)) is a natural gaseous carrier of phosphorus in its geochemical cycles, and it might be of importance to the phosphorus balance of natural ecosystem. For the first time phosphine levels were investigated in the Earth's coldest, driest, and most southerly Antarctic biosphere. Matrix-bound phosphine (MBP) was found in sea animal guanos, ornithogenic sediments and soils. Phosphine concentrations varied with different sea animal guanos. Average phosphine concentrations in empire penguin, gentoo penguin, sea lion, skua and gull guanos were 2.54+/-1.28 ng kg(-1), 6.21+/-2.15 ng kg(-1), 9.12+/-4.66 ng kg(-1), 11.90+/-1.29 ng kg(-1) and 14.55+/-6.74 ng kg(-1), respectively. The contents of phosphorus in these various matrixes have an important effect on MBP concentrations. The levels of phosphine appeared an increasing tendency with the content of TP, IP and OP in sea animal guanos, ornithogenic sediments or soils. The correlation between PH(3) and Fe, Mn, Al in these matrixes was also analyzed and discussed. Phosphine showed an obviously positive correlation with Fe in sea animal guanos. However, excessively high Fe, Al and Mn may inhibit the formation of PH(3) in the ornithogenic soils or sediments in the Antarctic biosphere.

Animals↗

PubMed2006

Adverse effects of asbestos exposure and smoking on lung function.

BACKGROUND: Exposure to asbestos is a well-recognized cause of both malignant and nonmalignant diseases of lung parenchyma and pleura. This study was conducted to determine the adverse effects of exposure to asbestos and smoking on pulmonary function. METHODS: Four hundred and sixty-eight workers who were occupationally exposed to asbestos for an average of 13 years were selected from an asbestos-product factory in China. Of them, 85 workers were diagnosed with asbestosis. Additionally, 282 workers who had no experience of exposure to industrial dust were included as a control group. A questionnaire was administered during a face-to-face interview and spirometric maneuvers and single-breath CO diffusing capacity (DL(CO)) were performed. RESULTS: Multivariate regression analysis showed that exposure to asbestos was more strongly associated with decreased forced vital capacity (FVC) and DL(CO), and asbestosis more strongly associated with decreased FVC, while smoking was a major contributing factor to reduced FEV1/FVC. The results were confirmed by a further analysis where the subjects were grouped exclusively by smoking, asbestos exposure, and chest radiographic changes. No interaction or joint effect was observed between asbestos exposure and smoking. CONCLUSIONS: This analysis suggested that asbestos and smoking might play independent roles, in which asbestos caused mainly a restrictive impairment, and smoking was a major causal factor for airway obstruction in the workers who were intensively exposed to asbestos.

Adult↗

PubMed2006

Anti-influenza agents from plants and traditional Chinese medicine.

Influenza is a serious threat to health in all parts of the world. The control and treatment of influenza depends mainly on chemical or biochemical agents and, to date, some anti-influenza agents have been isolated from plants as a result of chemical and pharmacological studies. These agents include a variety of polyphenols, flavonoids, saponins, glucosides and alkaloids. Traditional medicine focuses on the use of herbs and traditional Chinese medicine has performed well in clinical practice and shows a potential in the therapy of influenza and its symptoms. The present paper reviews some constituents and extracts from plants and traditional Chinese medicine with anti-influenza activity.

Antiviral Agents↗

PubMed2006

Common traditional Chinese medicinal herbs for dysmenorrhea.

Dysmenorrhea is painful menstrual cramps, which negatively impacts the quality of life of those diagnosed. The paper reviews traditional Chinese medicine's treatment of dysmenorrhea through the use of combination-herbal-formula therapeutics. These herbal treatments are effective for dysmenorrhea with minimal side effects. Pharmacological studies suggest Chinese herbal dysmenorrhea therapies likely decrease prostaglandin levels, modulate nitric oxide, increase plasma beta-endorphin (beta-EP) levels, block calcium-channels and improve microcirculation. Conventional therapy for dysmenorrhea, which usually includes non-steroidal antiinflammatory drugs (NSAIDs), provides symptomatic relief but has increasing adverse effects with long-term use. Therefore, Chinese herbal medicines, including simple herbal and combination formulas, are perhaps the ideal therapeutics of choice.

Drug Combinations↗

PubMed2006

HB tag modules for PCR-based gene tagging and tandem affinity purification in Saccharomyces cerevisiae.

We have recently developed the HB tag as a useful tool for tandem-affinity purification under native as well as fully denaturing conditions. The HB tag and its derivatives consist of a hexahistidine tag and a bacterially-derived in vivo biotinylation signal peptide, which support sequential purification by Ni2+ -chelate chromatography and binding to immobilized streptavidin. To facilitate tagging of budding yeast proteins with HB tags, we have created a series of plasmids with various selectable markers. These plasmids allow single-step PCR-based tagging and expression under control of the endogenous promoters or the inducible GAL1 promoter. HB tagging of several budding yeast ORFs demonstrated efficient biotinylation of the HB tag in vivo by endogenous yeast biotin ligases. No adverse effects of the HB tag on protein function were observed. The HB tagging plasmids presented here are related to previously reported epitope-tagging plasmids, allowing PCR-based tagging with the same locus-specific primer sets that are used for other widely used epitope-tagging strategies. The Sequences for the described plasmids were submitted to GenBank under Accession Numbers DQ407918-pFA6a-HBH-kanMX6 DQ407927-pFA6a-RGS18H-kanMX6 DQ407919-pFA6a-HBH-hphMX4 DQ407928-pFA6a-RGS18H-hphMX4 DQ407920-pFA6a-HBH-TRP1 DQ407929-pFA6a-RGS18H-TRP1 DQ407921-pFA6a-HTB-kanMX6 DQ407930-pFA6a-kanMX6-PGAL1-HBH DQ407922-pFA6a-HTB-hphMX4 DQ407931-pFA6a-TRP1-PGAL1-HBH DQ407923-pFA6a-HTB-TRP1 DQ407924-pFA6a-BIO-kanMX6 DQ407925-pFA6a-BIO-hphMX4 DQ407926-pFA6a-BIO-TRP1.

Base Sequence↗

PubMed2006

Bioaccumulation and antioxidant responses in goldfish Carassius auratus under HC Orange No. 1 exposure.

HC Orange No. 1 is used as a color additive in hair dyes and colors. In this study, laboratory experiments were carried out to determine the accumulation of HC Orange No. 1 in goldfish and the biochemical responses in liver of freshwater goldfish Carassius auratus. Goldfish were exposed to 1.0 mg/L HC Orange No. 1 for 6, 12, 24, 36, 48, 60, 72, and 96 h. Results showed that the concentrations of HC Orange No. 1 in water decreased rapidly in the first 24h, and then maintained equilibrium, while the concentrations of HC Orange No. 1 in goldfish reached a maximum level at 24 h, and then descended appreciably. For the total loss of HC Orange No. 1 in water 16.4% was due to the accumulation by goldfish, and approximately 57.6% resulted from metabolism by goldfish. After calculation, lgBCF is equal to 2.11. Hence, HC Orange bioaccumulation is significantly affected by a fast metabolic clearance in goldfish. Next, we investigated the biochemical responses in liver of freshwater goldfish C. auratus. It was shown that the hepatic antioxidant defense parameters of goldfish, including the contents of reduced glutathione (GSH) and activities of superoxide dismutase (SOD), catalase (CAT), glutathione S-transferase (GST), were highly sensitive to HC Orange No. 1 exposure, accompanied by changes of HC Orange No. 1 accumulation in liver tissue. Changes of these parameters indicated that there was an increase in the production of oxyradicals by goldfish and the presence of oxidative stress. These findings also implied that glutathione as well as other antioxidant enzymes function in the protection against HC Orange No. 1 toxicity and that these antioxidants provide a first line of defense against HC Orange No. 1, before the induction of any other detoxification mechanism.

Animals↗

PubMed2006

Cancer mortality among textile workers in Shanghai, China: a preliminary study.

OBJECTIVE: We assessed the association between cotton textile work and cancer mortality. METHODS: The cancer mortality experience of 912 (444 cotton, 468 silk) textile workers in Shanghai, China, was compared. Workers were followed from 1981 to 2003. The associations between cotton textile work and death due to all cancers combined (with and without lung cancer) and to gastrointestinal cancers were estimated with Cox models, adjusting for age, work years, and pack-years. RESULTS: There were 69 deaths. The adjusted hazard rate ratio (HR) was 2.10 (95% confidence interval [CI], 0.98-4.47) for all cancers combined and 2.56 (95% CI, 1.14-5.74) after excluding lung cancer. For gastrointestinal cancers, the adjusted HR was 2.09 (95% CI, 0.83-5.27). CONCLUSIONS: These preliminary data suggest that, with the exception of lung cancer, cotton workers have significantly higher cancer mortality rates than silk workers.

Adult↗

PubMed2006

Photorhabdus luminescens toxin-induced permeability change in Manduca sexta and Tenebrio molitor midgut brush border membrane and in unilamellar phospholipid vesicle.

Photorhabdus luminescens, a Gram-negative bacterium, secretes a protein toxin (PL toxin) that is toxic to insects. In this study, the effects of the PL toxin on large receptor-free unilamellar phospholipid vesicles (LUVs) of Manduca sexta and on brush border membrane vesicles (BBMVs) of M. sexta and Tenebrio molitor were examined. Cry1Ac served as a positive control in our experiments due to its known channel-forming activity on M. sexta. Voltage clamping assays with dissected midguts of M. sexta and T. molitor clearly showed that both Cry1Ac and PL toxin caused channel formation in the midguts, although channel formation was not detected for T. molitor midguts under Cry1Ac and it was less sensitive to PL toxin than to Cry1Ac for M. sexta midguts. Calcein release experiments showed that both toxins made LUVs (unilamellar lipid vesicles) permeable, and at some concentrations of the toxins such permeabilizing effects were pH-dependent. The lowest concentrations of PL toxin were more than 600-fold and 24-fold lower to induce BBMV permeability of T. molitor and M. sexta than those to induce calcein release from LUVs of M. sexta. These further support that PL toxin is responsible for channel formation in the larvae midguts. The lower concentration to induce permeability in BBMV than in LUV is, probably, attributable to that BBMV has PL toxin receptors that facilitate the toxin to induce permeabilization. Furthermore, our results indicate that the effects of PL toxin on BBMV permeability of M. sexta were not significantly influenced by Gal Nac, but those of Cry1Ac were. This implies that PL toxin and Cry1Ac might use different molecular binding sites in BBMV to cause channel formation.

Animals↗

PubMed2006

Mental ability and psychological work performance in Chinese workers.

This study was to explore the relationship among mental ability, occupational stress, and psychological work performance in Chinese workers, and to identify relevant modifiers of mental ability and psychological work performance. Psychological Stress Intensity (PSI), psychological work performance, and mental ability (Mental Function Index, MFI) were determined among 485 Chinese workers (aged 33 to 62 yr, 65% of men) with varied work occupations. Occupational Stress Questionnaire (OSQ) and mental ability with 3 tests (including immediate memory, digit span, and cipher decoding) were used. The relationship between mental ability and psychological work performance was analyzed with multiple linear regression approach. PSI, MFI, or psychological work performance were significantly different among different work types and educational level groups (p<0.01). Multiple linear regression analysis showed that MFI was significantly related to gender, age, educational level, and work type. Higher MFI and lower PSI predicted a better psychological work performance, even after adjusted for gender, age, educational level, and work type. The study suggests that occupational stress and low mental ability are important predictors for poor psychological work performance, which is modified by both gender and educational level.

Adult↗

PubMed2005

Microwave-assisted protein preparation and enzymatic digestion in proteomics.

The combinations of gel electrophoresis or LC and mass spectrometry are two popular approaches for large scale protein identification. However, the throughput of both approaches is limited by the speed of the protein digestion process. Present research into fast protein enzymatic digestion has been focused mainly on known proteins, and it is unclear whether these results can be extrapolated to complex protein mixtures. In this study microwave technology was used to develop a fast protein preparation and enzymatic digestion method for protein mixtures. The protein mixtures in solution or in gel were prepared and digested by microwave-assisted protein enzymatic digestion, which rapidly produces peptide fragments. The peptide fragments were further analyzed by capillary LC and ESI-ion trap-MS or MALDI-TOF-MS. The technique was optimized using bovine serum albumin and then applied to human urinary proteins and yeast lysate. The method enabled preparation and digestion of protein mixtures in solution (human urinary proteins) or in gel (yeast lysate) in 6 or 25 min, respectively. Equivalent (in-solution) or better (in-gel) digestion efficiency was obtained using microwave-assisted protein enzymatic digestion compared with the standard overnight digestion method. This new application of microwave technology to protein mixture preparation and enzymatic digestion will hasten the application of proteomic techniques to biological and clinical research.

Chromatography, Liquid↗

PubMed2005

Concanavalin A-captured glycoproteins in healthy human urine.

Both the urinary proteome and its glycoproteome can reflect human health status, and more directly, functions of kidney and urinary tracts. Because the high abundance protein albumin is not N-glycosylated, the urine N-glycoprotein enrichment procedure could deplete it, and urine proteome could thus provide a more detailed protein profile in addition to glycosylation information especially when albuminuria occurs in some kidney diseases. In terms of describing the details of urinary proteins, the urine glycoproteome is even a better choice than the proteome itself. Pooled urine samples from healthy volunteers were collected and acetone-precipitated for proteins. N-Linked glycoproteins enriched with concanavalin A affinity purification were separated and analyzed by SDS-PAGE-reverse phase LC/MS/MS or two-dimensional LC/MS/MS. A total of 225 urinary proteins were identified based on two-hit criteria with reliability over 97% for each peptide. Among these proteins, 94 were identified in previous urine proteome works, 150 were annotated as glycoproteins in Swiss-Prot, and 43 were predicted as glycoproteins by NetNGlyc 1.0. A number of known biomarkers and disease-related glycoproteins were identified. Because changes in protein quantity or the glycosylation status can lead to changes in the concanavalin A-captured glycoprotein profile, specific urine glycoproteome patterns might be observed for specific pathological conditions as multiplex urinary biomarkers. Knowledge of the urine glycoproteome is important in understanding kidney and body function.

Concanavalin A↗

PubMed2005

Bioaccumulation, depuration and oxidative stress in fish Carassius auratus under phenanthrene exposure.

In this study, laboratory experiment was carried out to determine phenanthrene bioaccumulation, depuration in whole fish and oxidative stress in the liver of freshwater fish Carassius auratus. Fish were exposed to 0.05 mg/l phenanthrene for different periods, while one control group was designated for each exposure group. Some fish after 7 days of exposure were transferred to diluted water. The concentrations of phenanthrene in fish were analyzed by HPLC. Twenty-four hours after the exposure, reactive oxygen species (ROS) were trapped by phenyl-tert-butylnitrone and detected by electron paramagnetic resonance (EPR). The activities of superoxide dismutase (SOD), catalase (CAT), and glutathione-s-transferase (GST) were also determined. The concentrations of phenanthrene in fish increased rapidly shortly after the start of the exposure, reached a maximum level at the 2 days, and then it declined quickly to low-level-steady state. The elimination process of phenanthrene could be divided into two periods-a fast elimination period following a slower loss period. The elimination curve could be fitted mathematically as the sum of two exponential functions according to two-compartment model: C(t)=2.72e(-1.065t) + 0.68e(-0.0364t). The PBN-radical adducts were detected in fish liver samples following the exposure 24h. The hyperfine splitting constants for the PBN-radical adducts were aN = 13.5 G, aH = 1.77 G and g value was 2.0058, which were consistent with those of PBN/()OH. The results indicated that the hydroxyl radical was probably significantly induced during the exposure of phenanthrene, as compared to the control group. The changes of activities of the antioxidant enzymes also were observed. In addition, after fish were removed from phenanthrene exposure, the recovery status of these antioxidant indices was explored. These results clearly indicated phenanthrene could be accumulated in fish and similar redox cyclings were produced, resulting in the changes of the activities of the antioxidant enzymes and the production of ROS with the oxidative stress.

Animals↗

PubMed2005

Electron paramagnetic resonance evidence of hydroxyl radical generation and oxidative damage induced by tetrabromobisphenol A in Carassius auratus.

Tetrabromobisphenol A (TBBPA) is one of the most widely used brominated flame retardants (BFRs). To confirm its putative oxidative stress-inducing activity, freshwater fish Carassius auratus were injected intraperitoneally with TBBPA. One experiment lasted 3h to 28 days after a single injection of 100mg/kg TBBPA, and the other lasted 24h after a single injection of 0-300 mg/kg TBBPA. Reactive oxygen species (ROS) were trapped by phenyl-tert-butyl nitrone (PBN) and detected by electron paramagnetic resonance (EPR). Protein carbonyl (PCO) and lipid peroxidation product (LPO) content were also determined. A six-line EPR spectrum was detected in the sample prepared in air, and a multiple one was obtained in nitrogen. The observed spectrum in nitrogen fits the simulation one with PBN/OCH(3) and PBN/CH(3) quite well. As compared to the control group, TBBPA significantly induced ROS production marked by the intensity of the prominent spectra in liver and bile. TBBPA (100mg/kg) also significantly increased PCO content in liver starting 24h and LPO content 3 days after injection. Either PCO or LPO content showed significant relation with ROS production. Based on the hyperfine constants and shape of the spectrum, ROS induced by TBBPA was determined as OH. The results clearly indicated that TBBPA could induce OH generation and result in oxidative damage in liver of C. auratus.

Analysis of Variance↗

PubMed2005

Strain-induced nonlinearity of filled rubbers.

Dynamic strain-induced nonlinearity in the modulus of filled rubbers shows a striking similarity to what is known about the glass transition of solid materials and the jamming transition of granular materials. This analogy stems from the reality that shear strain in dynamic mechanical measurements introduces fluctuations in a filler network by forcing the system to explore different configurations. Such fluctuations can be described by an "effective temperature" that has many attributes of a true temperature, and particularly is proportional to the strain amplitude. Thus, filled rubbers with respect to strain will display many unusual phenomena that are usually observed in glass-forming materials, but now demonstrated in filled rubbers, including asymmetric kinetics, crossover effects, and glasslike kinetic transitions. The nonlinearity in the modulus of filled rubbers simply reflects a dejamming transition of fillers in rubber matrices. The agglomeration of filler in an elastomeric matrix shares a common ground of physics with the jamming process and glass formation.

Journal Article↗