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Biomedical subjects

Min Yang

Publications and source records attributed to Min Yang.

At least 55 records · Page 3Linked to original sources
PubMed2006

Promoter activation by the varicella-zoster virus major transactivator IE62 and the cellular transcription factor USF.

The varicella-zoster virus major transactivator, IE62, can activate expression from homologous and heterologous promoters. High levels of IE62-mediated activation appear to involve synergy with cellular transcription factors. The work presented here focuses on functional interactions of IE62 with the ubiquitously expressed cellular factor USF. We have found that USF can synergize with IE62 to a similar extent on model minimal promoters and the complex native ORF28/29 regulatory element, neither of which contains a consensus IE62 binding site. Using Gal4 fusion constructs, we have found that the activation domain of USF1 is necessary and sufficient for synergistic activation with IE62. We have mapped the regions of USF and IE62 required for direct physical interaction. Deletion of the required region within IE62 does not ablate synergistic activation but does influence its efficiency depending on promoter architecture. Both proteins stabilize/increase binding of TATA binding protein/TFIID to promoter elements. These findings suggest a novel mechanism for the observed synergistic activation which requires neither site-specific IE62 binding to the promoter nor a direct physical interaction with USF.

Binding Sites↗
PubMed2006

Prevalence and correlates of personality disorder in Great Britain.

BACKGROUND: Epidemiological data on personality disorders, comorbidity and associated use of services are essential for health service policy. AIMS: To measure the prevalence and correlates of personality disorder in a representative community sample. METHOD: The Structured Clinical Interview for DSM-IVAxis II disorders was used to measure personality disorder in 626 persons aged 16-74 years in households in England, Scotland and Wales, in a two-phase survey. RESULTS: The weighted prevalence of personality disorder was 4.4% (95% CI 2.9-6.7). Rates were highest among men, separated and unemployed participants in urban locations. High use of healthcare services was confounded by comorbid mental disorder and substance misuse. Cluster B disorders were associated with early institutional care and criminality. CONCLUSIONS: Personality disorder is common in the community, especially in urban areas. Services are normally restricted to symptomatic, help-seeking individuals, but a vulnerable group with cluster B disorders can be identified early, are in care during childhood and enter the criminal justice system when young. This suggests the need for preventive interventions at the public mental health level.

Adolescent↗
PubMed2006

Violence and psychiatric morbidity in the national household population of Britain: public health implications.

BACKGROUND: It is unclear whether psychiatric morbidity contributes to the small proportion of the population responsible for a large percentage of antisocial behaviour, including violence. AIMS: To measure associations between psychiatric morbidity and severity, chronicity and types of victims of violence in the national household population of Britain. METHOD: Cross-sectional survey of persons in households (n = 8397).Data included self-reported location, victims and outcome of violence over the previous 5 years. Diagnoses were determined by computer-assisted interviews. RESULTS: Hazardous drinking was associated with over half of all incidents involving injury. Antisocial personality disorder conveyed an attributable risk of 24% of respondents reporting victim injuries, but screening positive for psychosis conveyed an attributable risk of only 1.2%. CONCLUSIONS: The burden of care resulting from violence associated with hazardous drinking supports population interventions. Despite exceptional risks, half of respondents with antisocial personality disorder were not violent, indicating limitations in targeted interventions to detain high-risk individuals.

Adolescent↗
PubMed2006

[Human pregnane X receptor-mediated transcriptional regulation of cytochrome P450 3A4 by some phytochemicals].

OBJECTIVE: To test the effect on human pregnane X receptor (hPXR)-mediated transcription regulation of CYP3A4 by five selected phytochemicals. METHODS: Transient cotransfection reporter gene assays in HepG(2) cells were performed with the hPXR expression plasmid and the reporter gene plasmid which contains XRE in the promoter of CYP3A4 linked to luciferase. RESULTS: In the dose-effect study, soybean isoflavone, luteolin and curcumin induced the CYP3A4 transcription via PXR in an evident dose-dependent manner, but isorhamnetin and rutin did not. The inducibility of soybean isoflavone, luteolin and curcumin was also increased in concentrations between 1 micromol/L and 50 micromol/L, 24 h after induction, 50 micromol/L soybean isoflavone, luteolin and curcumin exhibited a 5.46-fold, 2.87-fold, and 2.07-fold increase respectively, compared with 0.1% DMSO treated cells. In the time-effect study, 10 micromol/L and 50 micromol/L soybean isoflavone, luteolin and curcumin induced CYP3A4 transcription between 12 h and 48 h, the strongest induction appeared in 48 h. 48 h after induction, 50 micromol/L soybean isoflavone, luteolin and curcumin exhibited a 6.72-fold, 3.24-fold, and 2.13-fold increase respectively, compared with 0.1% DMSO treated cells. CONCLUSION: Three phytochemicals, i.e. soybean isoflavone, luteolin and curcumin stimulate the PXR-mediated transcription of CYP3A4. Isorhamnetin and rutin have no effect on the CYP3A4 transcription via PXR.

Carcinoma, Hepatocellular↗
PubMed2006

[Effect of kaempferol on the pharmacokinetics of nifedipine in rats].

OBJECTIVE: To investigate the effect of kaempferol on the pharmacokinetics of nifedipine (NFP) in rats. METHODS: Twenty male SD rats, weighing 220-260 g, were distributed randomly into 4 groups. The animals were fasted, but allowed free access to water for 12 h before the administration of drugs. NFP dissolved in corn oil was administered via gastric intubation to the rats in control group at a dose of 10 mg/kg. Kaempferol was administered orally to the other three groups with dose of 5, 10, 15 mg/kg, respectively, followed by oral administration of NFP 10 mg/kg. Blood samples were collected through tail vein in heparinized plastic microcentrifuge tubes before and after drug administration. The plasma concentration of NFP was monitored with reversed phase high-performance liquid chromatography (RP-HPLC). Nimodipine was used as the internal standard. Statistical data evaluation was performed with Student's t-test and one-way analysis of variances. RESULTS: The maximal plasma concentration (C(max)) of the three treated groups were 0.51, 0.70 and 0.81 microg/ml, respectively. The area under the concentration-time curve (AUC(0-8)) were 1.81, 2.83 and 3.63 microg/(h.ml(-1)), respectively. The C(max), AUC(0-8) and the mean retention time (MRT(0-8)) of NFP were significantly increased by simultaneous oral treatment with kaempferol (P<0.01). On the other hand, there were no significant differences in the mean peak value time in plasma (T(max)) and the elimination half-life (t1/2(ke)) between the control and the treated groups. CONCLUSION: The concomitant oral use of kaempferol with NFP may influence the pharmacokinetic parameters of NFP in rats, which suggests that kaempferol might reduce the first-pass metabolism of NFP.

Animals↗
PubMed2006

[Protection of Hsian-tsao (Mesona procumbens Hemsl)on H2O2-induced DNA damage of primarily cultured mice spleen lymphocytes].

OBJECTIVE: To investigate the protection of Hsian-tsao(Mesona procumbens Hemsl)on H(2)O(2)-induced DNA damage of primarily cultured spleen lymphocytes. METHODS: Spleen lymphocytes were primarily cultured for 24 h and then divided into 6 groups randomly: 4 groups were treated with different concentrations of Hsian-tsao extracts for 60 min, then with 50 micromol/L H(2)O(2); 1 group was treated with 50 micromol/L H(2)O(2) only and the last group with PBS. Twenty min after H(2)O(2)or PBS treatment SCGE and laser confocal microscopy were performed, then the comet length and percentage of cells with migrated DNA were measured. RESULTS: H(2)O(2) caused severe DNA damage in primarily cultured spleen lymphocytes and Hsian-tsao extracts reduced the DNA damage at a concentration of 10, 50 and 100 microg/ml. The quantity of comet cells was reduced from 100% to 88%, 60%, 36% (P<0.05, 0.01, 0.01) and the comet length was reduced from (49.56+/-6.94) microm to (41.14+/-5.64) microm, (38.89+/-9.81) microm, (28.62+/-4.66) microm (P<0.05, 0.01, 0.01), respectively. CONCLUSION: Hsian-tsao has dramatic ability of antioxidant. It can protect cells from the damage of ROS-induced DNA injury in the certain range.

Animals↗
PubMed2006

[In vitro inhibitory effect of 23-HBA on angiogenesis].

AIM: To study the inhibitory effect of 23-HBA on angiogenesis in vitro. METHODS: The effect of 23-hydroxy butulinic acid (23-HBA) on the in vitro proliferation of human microcapillary endothelial cells(HMECs) was examined by sulfonylrhodamine B (SRB) assay. The effect of 23-HBA on endothelial cell migration, and tubule formation on Matrigel was also observed. The CD31 expression in HMECs was dectected by immunohistochemical staining. RESULTS: The proliferation of HMECs was inhibited significantly by 23-HBA with IC(50) being 40.44 mg/L. 23-HBA inhibited endothelial cell migration and tubule formation in a dose-dependent manner. The expression of CD31 in HMECs was reduced after treatment with 10 mg/L 23-HBA. CONCLUSION: 23-HBA can inhibit angiogenesis in vitro, which would become a promising antiangiogenic drug.

Angiogenesis Inhibitors↗
PubMed2006

[Kinetic turbidimetric limulus assay of bacterial endotoxin in the replacement solution of on-line hemodiafiltration].

OBJECTIVE: To determine bacterial endotoxin in the replacement solution of on-line hemodiafiltration (on-line HDF) using kinetic turbidimetric limulus test. METHODS AND RESULTS: Validation test was performed with the replacement solution of on-line HDF in which quantified standard endotoxin was added. The recovery rates of endotoxin from the replacement solution and its dilutions at 1/5, 1/10, and 1/20 were 58.17%, 106.7%, 99.00% and 98.79%, respectively, suggesting that the optimal dilution was at 1/10. Standard endotoxin was added into the replacement solution of on-line HDF of 3 batches (040408, 040511,040527), and the recovery rates in their dilution at 1/10 were 76.32%, 99.00% and 96.24%, respectively. The standard endotoxin in the working curve was 1.00, 0.125, and 0.0156 Eu/ml (endotoxin unit/ml), and the dilution at 1/10 of the replacement solution is effective to eliminate the interference in limulus test. CONCLUSION: Kinetic turbidimetric limulus test provide a means to detect endotoxin in the replacement solution of on-line HDF.

Endotoxins↗
PubMed2006

Natural products and anti-inflammatory activity.

The aim of this review paper was to summarise some commonly available natural products and their anti-inflammatory activity. We have collected data from MEDLINE, Current Contents and scientific journals, which included 92 publications. There are numerous natural products detailed in this literature; however we have summarized a few of the most commonly available and potent ones. In this paper, the natural products with anti-inflammatory activity including curcumin, parthenolide, cucurbitacins, 1,8-cineole, pseudopterosins, lyprinol, bromelain, flavonoids, saponins, marine sponge natural products and Boswellia serrata gum resin were reviewed. Natural products play a significant role in human health in relation to the prevention and treatment of inflammatory conditions. Further studies are being conducted to investigate the mechanism of action, metabolism, safety and long term side effect of these natural products, as well as interactions between these natural products with food and drug components.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed2006

[Comparison of hydroxyl radical production rates in H2O2 solution under homogeneous catalysis of Fe3+ or Fe2+].

The production of *OH radicals was investigated by using the electron spin resonance (ESR) method with 5,5-dimethyl-1-lpyrroline-1-oxide (DMPO) as spin trap reagent. ESR signals composed of 4 lines with a 1:2:2:1 intensity ratio indicated the formation of *OH radicals in the Fenton-like reaction. For both systems, the production rates of hydroxyl radicals in the initial stage were considerably high, and increased with increasing concentrations of H2O2 and Fe2+ or Fe3+. However, the radical production rate in Fenton reaction system was markedly higher than that in Fenton-like reaction under similar dosing conditions. The differences of radical production rates between the reaction systems remained even in the slow reaction stage. The optimum pH ranges of the production of *OH radicals in Fenton process and Fenton-like process were 2.5 to approximately 3.5 and 2.8 to approximately 3.0 respectively. The above results demonstrate that the Fenton system and Fenton-like system are possibly based on different reaction mechanisms.

Catalysis↗
PubMed2006

High-performance liquid chromatographic determination of tanshinones in the roots of Salvia miltiorrhiza and related traditional chinese medicinal preparations.

PURPOSE: This paper describes a validated high-performance liquid chromatographic method to quantitate four tanshinones as markers; dihydrotanshinone I, cryptotanshinone, tanshinone I and tanshinone IIA for use in the quality control of the roots of Salvia miltiorrhiza and its related traditional Chinese medicinal preparations. METHODS: Separation was achieved using a Zorbax Extend C18 reserved-phase column (5microm, 250*4.6mm) at 20 degrees with a gradient mixture of deionized water and acetonitrile at a flow rate of 1.2ml/min. RESULT: The limits of quantitation were 0.13, 0.08, 0.06 and 0.05microg/ml for dihydrotanshinone I, cryptotanshinone, tanshinone I and tanshinone IIA, respectively. This method provided good reproducibility and sensitivity for the quantification of four tanshinones with overall RSD values for intra-day and inter-day precision and accuracy better than 3.8% and higher than 94.9%, respectively. The recovery of the method was 95.4-104.4% for all the tanshinones and showed good linearity (r>0.9998) over a relatively wide concentration range. CONCLUSIONS: This assay was successfully applied to the determination of four tanshinones in the roots of Salvia miltiorrhiza and its related traditional Chinese medicinal preparations. The results indicated that the HPLC assay could be readily utilized as a quality control method for the roots of Salvia miltiorrhiza and its related traditional Chinese medicinal preparations.

Abietanes↗
PubMed2006

[Association between polymorphisms of XPD gene and susceptibility to chronic benzene poisoning].

OBJECTIVE: To explore the relationship between genetic polymorphisms of XPD gene and susceptibility to chronic benzene poisoning. METHODS: A case control study was conducted. Eighty patients diagnosed with chronic benzene poisoning and 62 workers occupationally exposed to benzene who were engaged in the same working time and job title as patients were investigated. PCR-RFLP was used for detecting the single nucleotide polymorphisms (SNPs) on codon156, codon312 and codon751 of XPD gene. RESULTS: There was a 2.903 times (95% CI: 1.054 - 7.959, P = 0.039 2) increased risk of chronic benzene poisoning in the subjects carrying XPD 751Gln variant allele compared with those carrying XPD 751Lys/Lys genotype, after adjusted for sex, length of service, smoking and drinking status. CONCLUSION: The subjects with XPD 751Gln variant allele are more susceptive to benzene.

Alleles↗
PubMed2006

Association of angiotensin converting enzyme gene I/D polymorphism with type 2 diabetes mellitus.

OBJECTIVE: To investigate the association of angiotensin converting enzyme (ACE) gene insertion/deletion (I/D) polymorphism with type 2 diabetes mellitus (T2DM). METHODS: Two hundred and nine patients with T2DM diagnosed based on the criteria for diabetes mellitus in 1999 by WHO and 221 controls were recruited from general population of Dongcheng District in Beijing. All subjects were genotyped for the I/D polymorphism of ACE gene by PCR-fragment length polymorphism (FLP) assay. Blood pressure, levels of plasma glucose, lipids and serum insulin were determined. Body mass index (BMI), waist-hip ratio (WHR) and homeostasis model assessment-insulin resistance index (HOMA-IR) were calculated. RESULTS: The genotype frequencies for ACE genes DD, ID, and II were 19.1%, 42.1%, and 38.8% in patients, respectively, and 9.6%, 49.4%, and 41.0% in controls, respectively. The ACE DD genotype frequency was significantly higher in patients than in controls (chi2 = 7.61, P = 0.022). Multivariate logistic regression analysis showed that the ACE DD genotype was a risk factor for T2DM, with the OR of 2.35 (95% CI 1.17-4.71) adjusted for age, sex, BMI, WHR, blood pressure, and serum cholesterol levels. CONCLUSION: The ACE DD genotype is associated with the increased susceptibility to type 2 diabetes mellitus.

Adult↗
PubMed2006

[Effects of hydraulic retention time (HRT) on nitrification performance and microbial community of conventional activated sludge (CAS)].

A conventional activated sludge system was used to treat the ammonium-bearing inorganic wastewater for 260 days under decreased HRTs. When treating 500 mg x L(-1) NH4+ -N wastewater, over 98% ammonia removal could be obtained at HRT > or =20 h. Sharp washout of biomass occurred when HRT was further decreased, resulting in the accumulation of ammonium and nitrite. Changes in the community structure were monitored by microbial quinone and conventional analytical methods. Quinone profiles indicated that ammonia-oxidizing bacteria (AOB) in beta-Protevbacteria and Nitrobacteria in alpha-Proteobacteria were the predominant species to oxidize ammonia and nitrite, respectively. The number of AOB decreased with the reduction of biomass in bioreactor, while that of nitrite-oxidizing bacteria (NOB) changed little and fluctuated at 10(5) CFU x L(-1)

Biodiversity↗
PubMed2005

Cathepsin S controls angiogenesis and tumor growth via matrix-derived angiogenic factors.

The cysteine protease cathepsin S is highly expressed in malignant tissues. By using a mouse model of multistage murine pancreatic islet cell carcinogenesis in which cysteine cathepsin activity has been functionally implicated, we demonstrated that selective cathepsin S deficiency impaired angiogenesis and tumor cell proliferation, thereby impairing angiogenic islet formation and the growth of solid tumors, whereas the absence of its endogenous inhibitor cystatin C resulted in opposite phenotypes. Although mitogenic vascular endothelial growth factor, transforming growth factor-beta1, and the anti-angiogenic endostatin levels in either serum or carcinoma tissue extracts did not change in cathepsin S- or cystatin C-null mice, tumor tissue basic fibroblast growth factor and serum type 1 insulin growth factor levels were higher in cystatin C-null mice, and serum type 1 insulin growth factor levels were also increased in cathepsin S-null mice. Furthermore, cathepsin S affected the production of type IV collagen-derived anti-angiogenic peptides and the generation of bioactive pro-angiogenic gamma2 fragments from laminin-5, revealing a functional role for cathepsin S in angiogenesis and neoplastic progression.

Angiogenesis Inducing Agents↗
PubMed2005

Nitrification performance and microbial community dynamics in a submerged membrane bioreactor with complete sludge retention.

A submerged membrane bioreactor (MBR) supplied with inorganic ammonium-bearing wastewater (NH(4)(+)-N, 500 mgl(-1)) was operated for 260 days without sludge purge under decreased hydraulic retention times (HRT) through six steps (from 30 to 5h). Almost complete nitrification was obtained at a volumetric loading rate (VLR)1.2g NH(4)(+)-Nl(-1)day(-1). The sludge nitrification activities were evaluated at each stage. The specific ammonium oxidizing rate (SAOR) decreased from the initial 0.45 to 0.15 kg NH(4)(+)-Nkg(-1)MLSSday(-1) in the last four stages, while the specific nitrate forming rate (SNFR) increased from 0.17 to 0.39 kg NO(3)(-)-Nkg(-1)MLSSday(-1) at the third stage, and then decreased to below 0.1 kg NO(3)(-)-Nkg(-1)MLSSday(-1) from the fourth stage. Microbial population dynamics was investigated by a combination of the MPN method, fluorescence in situ hybridization (FISH) and quinone profiles. During the experiment, although the MLSS increased gradually from 4.5 to 11.5 gl(-1), the number of ammonia-oxidizing bacteria (AOB) decreased from 10(9)l(-1) at the third stage to 10(7)l(-1) in the last two stages, and that of nitrite-oxidizing bacteria (NOB) decreased gradually from 10(8)l(-1) at the second stage (HRT of 20 h) to the final 10(5)l(-1). FISH results showed that the active cells decreased gradually with time from about 60 to 20% in the last two stages, and most of sludge was inert cells. The sum of nitrifiers occupied only about 10% of the total bacteria number in the last stage even though only ammonium-bearing inorganic wastewater was fed in. Nitrosomonas sp. and Nitrospira sp. were confirmed by FISH as the dominant nitrifying genera responsible for ammonia and nitrite oxidation, respectively. In the mean time, a small ratio of Nitrobacter sp. also existed in the system. FISH analysis matched better with the batch activity test results than did the MPN techniques. Quinone profiles revealed that the dominant ubiquinone was ubiquinone-8 (UQ-8), ranging from 84 to 66%, followed by UQ-10 of 7-13%, UQ-7 of 3-5% and UQ-9 of 1.6-2.6%. The dominant menaquinone in the MBR was menaquinone-7 (MK-7) followed by MK-6, MK-8 and MK-8 (H(2)). With the prolongation of operation, the percentage of menaquinones increased from 8 to 14%. The use of the polyphasic approach gave some new insight on variations of microbial community structures.

Bacteria↗
PubMed2005

Determination of diallyldimethylammonium chloride in drinking water by reversed-phase ion-pair chromatography-electrospray ionization mass spectrometry.

A method for the direct determination of diallyldimethylammonium chloride (DADMAC) in water samples, using ion-pair liquid chromatography-mass spectrometry system was developed. The chromatographic separation was performed using a C18 column. The type, the concentration of ion-pair reagent and the pH were optimized to give good chromatographic retention and sensitivity for DADMAC. Quantification was achieved in the positive electrospray ionization mode using selected ion monitoring. The cone voltage was also studied to establish the optimal experimental conditions. Finally, the reproducibility of the proposed method was shown by good run-to-run and day-to-day precision values. No sample preparation was required and the detection limit was 0.1 microg/L. The method was used to detect residual DADMAC at drinking water treatment plants in Tianjin, north China. The concentration of DADMAC observed in drinking water ranged from below quantitation limit to 22.0 microg/L.

Allyl Compounds↗