[Determination of trichloroethylene induced DNA damage with 32P-Postlabeling].
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Animals↗
Biomedical subjects
Liang Chen
Publications and source records attributed to Liang Chen.
[Specific depletion of naringin from Si-Ni-San, a traditional Chinese prescription, by an immunoaffinity chromatography].
To specifically deplete the compound naringin from Si-Ni-San, a traditional Chinese prescription, an immunoaffinity chromatography column was prepared. The naringin bovine serum albumin (BSA) complex (naringin-BSA) was synthesized to make the complete antigen naringin-BSA. Polyclonal antibody was prepared from the serum of rabbit immunized with naringin-BSA. Then, an immunoaffinity column was made by covalently coupling the polyclonal antibody to CNBr-activated Sepharose 4B and used for depleting naringin from Si-Ni-San. The polyclonal antibody obtained from the rabbit serum was found through enzyme linked immunosorbent assay (ELISA) to show the titer of 1:30,000, the purity of 94% and low cross-reaction rate. The coupling rate of the polyclonal antibody to Sepharose 4B was 87%. By using this column, naringin in Si-Ni-San was selectively depleted from the whole extract. This immunoaffinity column of anti-naringin antibody could be used for specifically depleting naringin from Si-Ni-San and other samples.
Animals↗
[Influence of substance P on the release of histamine in the human hypertrophic scar tissue].
OBJECTIVE: To investigate the influence of substance P (SP) on the release of histamine in the human hypertrophic scar tissue, and to explore the prerequisite of their interaction. METHODS: Tissue specimens of normal skin and hypertrophic scar from eight hospitalized patients were excised and cut into 0.5 to 1.0 mm3 pieces, and the histamine release by mast cell (MC) under the stimulation of different concentration of SP and calcium, as well as the different affect time of SP, were determined with fluorescence spectrometer. Then the histamine release rate was calculated. RESULTS: There was obvious release of histamine when SP concentration was 1 x 10(-6) mol/L , and the release rate was (50.0 +/- 3.6) %, which was significantly higher than that by SP in the concentration of 0 mol/L [(44.0 +/- 3.2) %, P < 0.01]. Therefore it seemed to be dose-dependent. About 90% of histamine was released within 15 minutes of 5 x 10(-1) mol/L Substance P stimulation, and it was also time-dependent. The histamine release reached the peak when calcium concentration was 5 x 10(-3) mol/L, which seemed to be dose-dependent, but it decreased transiently when calcium concentration was 1 x 10(-3) mol/L. In all occasions, the influence of SP on the histamine release by MC in hypertrophic scar (HS) was markedly higher than that in normal skin (NS) (P < 0.01). Conclusion The influence of SP on the histamine release by MC in HS was markedly higher than that in NS, and it might be closely related to itching sensation and the formation of hypertrophic scar.
Child↗
[Construction of pGEX4T-1-Cox7a2 and expression, purification and identification of the recombinant protein].
OBJECTIVE: To clone and express Cox7a2, one mitochondrial respiratory chain related gene, and to identify its recombinant protein. METHODS: The coding region of Cox7a2 was amplified from primary cultured mouse Leydig cells by RT-PCR. The PCR product was cloned into pGEX4T-1 vector by BamH I and EcoR I sites, and confirmed by DNA sequencing. The recombinant fusion protein vector was transformed and expressed into BL21. The recombinant fusion protein was identified by Western blotting. RESULTS: The entire coding region of Cox7a2 was cloned and expressed. The fusion protein was identified by anti-GST monoclonal antibody using Western blotting. CONCLUSION: The cloning of Cox7a2 and the expression of the recombinant protein would help to study the detailed function of Cox7a2, one respiratory chain related and highly differently expressed gene in the tissues of aging testes.
Animals↗
[Construction and expression of ATP50 fluorescent protein in TM3 mouse Leydig cells].
OBJECTIVE: To study the expression and localization of ATP50 by construction of ATP50-pEYFP-N1 in primary cultured mouse Leydig cells. METHODS: Primary cultured mouse Leydig cells were confirmed by 3B-HSD staining. ATP50 was cloned into pEYFP-N1 between Bam HI and Eco RI sites. Cell-transfection and living-cell fluorescence imaging microscopy were employed to investigate the sub-cellular localization of YFP-ATP50 in TM3 mouse Leydig cells. RESULTS: ATP50 green fluorescent protein was well co-localized with red fluorescence mitochondrion marker-Mitotracker in TM3 mouse Leydig cells. CONCLUSION: ATP50 was expressed in primary cultured mouse Leydig cells. The fluorescent expression vector of ATP50 was constructed successfully and YFP-ATP50 was located in mitochondria in TM3 mouse Leydig cells, which provided a useful clue for further research on the steroidogenesis dysfunction in aging males.
Adenosine Triphosphatases↗
A Bayesian genome screening of maximum number of drinks as an alcoholism phenotype with the new Haseman-Elston method.
Common human disorders, such as alcoholism, may be the result of interactions of many genes as well as environmental risk factors. Therefore, it is important to incorporate gene x gene and gene x environment interactions in complex disease gene mapping. In this study, we applied a robust Bayesian genome screening method that can incorporate interaction effects to map genes underlying alcoholism through its application to the data of the Collaborative Studies on Genetics of Alcoholism provided by Genetic Analysis Workshop 14. Our Bayesian genome screening method uses the regression-based stochastic variable selection, coupled with the new Haseman-Elston method to identify markers linked to phenotypes of interest. Compared to traditional linkage methods based on single-gene disease models, our method allows for multilocus disease models for simultaneous screening including both main and interaction (epistatic) effects. It is conceptually simple and computationally efficient through the use of Gibbs sampler. We conducted genome-wide analysis and comparison between scans based on microsatellites and single-nucleotide polymorphisms. A total of 328 microsatellites and 11,560 single-nucleotide polymorphisms (by Affymetrix) on 22 autosomal chromosomes and sex chromosome were used.
Alcoholism↗
Whole-genome association studies on alcoholism comparing different phenotypes using single-nucleotide polymorphisms and microsatellites.
Alcoholism is a complex disease. As with other common diseases, genetic variants underlying alcoholism have been illusive, possibly due to the small effect from each individual susceptible variant, gene x environment and gene x gene interactions and complications in phenotype definition. We conducted association tests, the family-based association tests (FBAT) and the backward haplotype transmission association (BHTA), on the Collaborative Study of the Genetics of Alcoholism (COGA) data provided by Genetic Analysis Workshop (GAW) 14. Efron's local false discovery rate method was applied to control the proportion of false discoveries. For FBAT, we compared the results based on different types of genetic markers (single-nucleotide polymorphisms (SNPs) versus microsatellites) and different phenotype definitions (clinical diagnoses versus electrophysiological phenotypes). Significant association results were found only between SNPs and clinical diagnoses. In contrast, significant results were found only between microsatellites and electrophysiological phenotypes. In addition, we obtained the association results for SNPs and microsatellites using COGA diagnosis as phenotype based on BHTA. In this case, the results for SNPs and microsatellites are more consistent. Compared to FBAT, more significant markers are detected with BHTA.
Alcoholism↗
Comparison of single-nucleotide polymorphisms and microsatellites in inference of population structure.
Single-nucleotide polymorphisms (SNPs) are a class of attractive genetic markers for population genetic studies and for identifying genetic variations underlying complex traits. However, the usefulness and efficiency of SNPs in comparison to microsatellites in different scientific contexts, e.g., population structure inference or association analysis, still must be systematically evaluated through large empirical studies. In this article, we use the Collaborative Studies on Genetics of Alcoholism (COGA) data from Genetic Analysis Workshop 14 (GAW14) to compare the performance of microsatellites and SNPs in the whole human genome in the context of population structure inference. A total of 328 microsatellites and 15,840 SNPs are used to infer population structure in 236 unrelated individuals. We find that, on average, the informativeness of random microsatellites is four to twelve times that of random SNPs for various population comparisons, which is consistent with previous studies. Our results also indicate that for the combined set of microsatellites and SNPs, SNPs constitute the majority among the most informative markers and the use of these SNPs leads to better inference of population structure than the use of microsatellites. We also find that the inclusion of less informative markers may add noise and worsen the results.
Genetic Loci↗
Whole-genome linkage analysis in mapping alcoholism genes using single-nucleotide polymorphisms and microsatellites.
There is currently a great interest in using single-nucleotide polymorphisms (SNPs) in genetic linkage and association studies because of the abundance of SNPs as well as the availability of high-throughput genotyping technologies. In this study, we compared the performance of whole-genome scans using SNPs with microsatellites on 143 pedigrees from the Collaborative Studies on Genetics of Alcoholism provided by Genetic Analysis Workshop 14. A total of 315 microsatellites and 10,081 SNPs from Affymetrix on 22 autosomal chromosomes were used in our analyses. We found that the results from the two scans had good overall concordance. One region on chromosome 2 and two regions on chromosome 7 showed significant linkage signals (i.e., NPL >or= 2) for alcoholism from both the SNP and microsatellite scans. The different results observed between the two scans may be explained by the difference observed in information content between the SNPs and the microsatellites.
Alcoholism↗
Whole-genome association analysis to identify markers associated with recombination rates using single-nucleotide polymorphisms and microsatellites.
Recombination during meiosis is one of the most important biological processes, and the level of recombination rates for a given individual is under genetic control. In this study, we conducted genome-wide association studies to identify chromosomal regions associated with recombination rates. We analyzed genotype data collected on the pedigrees in the Collaborative Study on the Genetics on Alcoholism data provided by Genetic Analysis Workshop 14. A total of 315 microsatellites and 10,081 single-nucleotide polymorphisms from Affymetrix on 22 autosomal chromosomes were used in our association analysis. Genome-wide gender-specific recombination counts for family founders were inferred first and association analysis was performed using multiple linear regressions. We used the positive false discovery rate (pFDR) to account for multiple comparisons in the two genome-wide scans. Eight regions showed some evidence of association with recombination counts based on the single-nucleotide polymorphism analysis after adjusting for multiple comparisons. However, no region was found to be significant using microsatellites.
Female↗
Controlling polymer architecture through host-guest interactions.
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Journal Article↗
Plasma metallothionein antibody and cadmium-induced renal dysfunction in an occupational population in China.
It has been reported that anti-metallothionein (a metallothionein antibody) is present in the circulation of healthy subjects and in patients suffering from atopic dermatitis. The aim of this study was to investigate whether cadmium-induced renal dysfunction is related to the presence of the plasma metallothionein antibody (MT-Ab) in workers exposed to cadmium (Cd) occupationally. Plasma metallothionein antibody was determined by enzyme linked immunosorbent assay (ELISA) techniques, and both exposure assessment and risk assessment were conducted in cadmium-exposed workers in China. We demonstrate that there is a significantly increased prevalence of renal dysfunction with respect to the level of urinary cadmium in a dose-dependent manner. We found no significant correlations between the levels of MT-Ab and the external or internal exposure doses of cadmium (p > 0.05), but the levels of MT-Ab did correlate positively with two biomarkers of renal dysfunction-urinary beta2-microglobulin (UB2M; r = 0.218, p < 0.05) and N-acetyl-beta-D-glucosaminidase (UNAG; r = 0.302, p < 0.001)-in the cadmium-exposed workers. Workers who have high levels of MT-Ab display cadmium-induced tubular nephrotoxicity more frequently than those possessing low levels of MT-Ab; odds ratio (OR) 4.2; 95% confidence intervals 1.2-14.5 (p < 0.05). This study suggests that subjects that have higher MT-Ab levels more readily develop cadmium-induced renal dysfunction. Thus, the levels of plasma MT-Ab can be used as a biomarker of susceptibility to renal dysfunction in occupational cadmium exposure.
Adult↗
Organic chemistry in water.
Water has emerged as a versatile solvent for organic chemistry in recent years. Water as a solvent is not only inexpensive and environmentally benign, but also gives completely new reactivity. The types of organic reactions in water are broad including pericyclic reactions, reactions of carbanion equivalent, reactions of carbocation equivalent, reactions of radicals and carbenes, transition-metal catalysis, oxidations-reductions, which we discuss in this tutorial review. Aqueous organic reactions have broad applications such as synthesis of biological compounds from carbohydrates and chemical modification of biomolecules.
Journal Article↗
Enhancement of stimulated Brillouin scattering of higher-order acoustic modes in single-mode optical fiber.
Solving the elastic wave equation exactly for a GeO2-doped silica fiber with a steplike distribution of the longitudinal and shear velocities and density, we have obtained the dispersion, attenuation, and fields of the leaky acoustic modes supported by the fiber. We have developed a model for stimulated Brillouin scattering of these modes in a pump-probe configuration and provided their Brillouin gains and frequencies for an extended range of core sizes and GeO2 doping. Parameter ranges close to cutoff of the acoustic modes and pump depletion enhance the ratio of higher-order peaks to the main peak in the Brillouin spectrum and are suitable for simultaneous strain-temperature sensing.
Journal Article↗
Extract from Agaricus blazei Murill can enhance immune responses elicited by DNA vaccine against foot-and-mouth disease.
The fungus Agaricus blazei Murill (ABM) is particularly rich in polysaccharides, which have shown particularly strong results in treating and preventing cancers. The goal of this study was to investigate whether co-administration of the ABM extract with foot-and-mouth disease virus (FMDV) DNA vaccine could increase the immune responses. Compared with the control mice, which received FMDV DNA vaccine alone, significant increase in not only the FMDV-specific antibody response but also T cell proliferation was observed in mice which received FMDV DNA vaccine plus the ABM extract. Taken together, these results demonstrated that application of the ABM extract might provide a strategy to improve the efficacy of DNA vaccines.
Adjuvants, Immunologic↗
Cage migration in spondylolisthesis treated with posterior lumbar interbody fusion using BAK cages.
STUDY DESIGN: A retrospective study was conducted to review the complication of cage migration in posterior lumbar interbody fusion (PLIF) with the Bagby and Kuslich method. OBJECTIVE: To review and analyze cage migration in spondylolytic spondylolisthesis treated with PLIF using paired BAK cages. SUMMARY OF BACKGROUND DATA: PLIF with cages has been introduced to treat spondylolisthesis for several years. Theoretically, this technique offers several advantages. BAK system gained popularity rapidly in recent few years. However, most reports focused on clinical effects; only a few studies had been carried out to review complications. As one of the major complications, cage migration into vertebral body or spinal canal may result in severe or disastrous consequence, only a few reports discussed on this issue. METHODS: From October 1997 to August 2000, 118 patients with spondylolytic spondylolisthesis underwent single-level PLIF using paired BAK cages filled with morselized autogenous bone; 88 of them were followed up for more than 2 years with an average of 3 years and 10 months. The complication of cage migration and its sequelae were reviewed. RESULTS: Three cases of cage retropulsion and four cases of cage subsidence were found in the current study. The rate of cage migration in patients with no posterior instrumentation was significantly higher compared with that rate in those with posterior instrumentation (16.7% vs. 0%). For patients with no posterior instrumentation, 4 of 8 cases with total facetectomy and 3 of 34 cases with partial facetectomy developed cage migration; the rate of cage migration was 16% for patients with preoperative Grade I olisthesis and 17.6% for those with preoperative Grade II olisthesis (P > 0.05). All patients with cage subsidence lost some degree of lumbar lordosis and disc height, 2 of them finally obtained suboptimal fusion, the other 2 developed pseudarthrosis and received additional posterior instrumentation and intertransverse fusion. Two patients with cage retropulsion developed severe lumbar stenosis and have to remove their dislocated cages. The other one received conservative treatment. CONCLUSION: An 8% rate of cage migration was found in the current study, and 4 of 7 cases with cage migration received revision surgery. Several factors may contribute to the cage migration, including lack of posterior instrumentation and total facetectomy. Revision surgery for cage migration was technically challenging.
Adult↗
Simple approach to determining the minimum measurable stress length and stress measurement accuracy in distributed Brillouin sensing.
A simple approach is proposed for quantifying the errors in measuring the Brillouin frequency shifts associated with stresses whose lengths are shorter than the pulse length. The smallest detectable Brillouin frequency shift is thus determined with respect to the size of the stressed sections and the frequency resolution. The lowest detectable frequency shift is found to be approximately 42% of the Brillouin gain natural linewidth. A worst-case iso-error curve that associates the minimum frequency shift to the length of the stressed region is derived. A minimum resolvable frequency shift and minimum detectable stress length are defined with an approach based on a Rayleigh equivalent criterion.
Journal Article↗
Simple method to identify the spatial location better than the pulse length with high strain accuracy.
The second-order partial derivative of the Stokes signal with respect to frequency and position shows a maximum or minimum at the boundary between two different strained sections. This idea is used to locate the boundary of different stress regions. Knowing the boundaries, we then fit the Brillouin spectrum at the middle between them to get the strain value. This allows a location accuracy of between 5 and 10 cm, which is shorter than the pulse length of 20 cm used in the experiment. The lowest detectable Brillouin frequency difference between two strain sections is 1.2 MHz.
Journal Article↗