2004 Vol. 17, No. 2
Damaging Effect of Cigarette Smoke Extract on Primary Cultured Human Umbilical Vein Endothelial Cells and Its Mechanism
2004, 17(2): 121-134.
Objective To investigate the cellular effects of cigarette smoke extract (CSE) on primarily cultured human umbilical vein endothelial cells (HUVEC). Methods The effects of CSE (5%-20%) and nicotine (10-4 mol/L) on HUVEC viability, proliferation, angiogenesis and apoptosis were observed. Results CSE decreased HUVEC survival rate and angiogenesis after 24 h as well as its proliferation after 48 h in a dose-dependent manner. Moreover, CSE induced apoptosis of HUVEC as indicated in condensation of nuclear chromatin and the presence of hypodiploid DNA. HUVEC incubated with CSE for 24 h gave a significant decrease in the expression of Bcl-2 as well as the decline in the Bcl-2/Bax ratio accompanied with the loss of mitochondrial membrane potential and excess cytosolic calcium. Our study also observed that p53 protein level decreased, rather than increased in cells treated with CSE. Nicotine had no discernible inhibitory effects on the above indices of HUVEC. Conclusion Exposure to CSE other than nicotine causes inhibition of viability, proliferation and differentiation of HUVEC. CSE-induced HUVEC injury is mediated in part through accelerated apoptosis but independent of p53 pathway. It appears that mitochondria have played a key role in the apoptosis of HUVEC induced by CSE.
2004, 17(2): 135-143.
Objective To study the effect of gene radiotherapy combining injection of recombinant plasmid pNEgr-mIL-12 with local X-irradiation on cancer growth and to elucidate the mechanisms of tumor inhibition. Methods Alkaline lysis was used to extract the plasmid and polyethylene glycol 8000 (PEG 8000) was applied for further purification of plasmids. Enzyme-linked immunosorbent assay (ELISA) was used to detect the expression of IL-12 protein. C57BL/6J mice were subcutaneously inoculated with B16 melanoma cells and the plasmid was injected directly into the tumor. Gene-radiotherapy combining pNEgr-mIL-12 recombinant plasmid with X-irradiation was given three times to C57BL/6J mice bearing B16 melanoma. Changes in immunologic parameters of tumor-bearing mice were detected with relevant immunologic assays. Results Results showed a significant decrease in tumor growth rate (P<0.05-0.001) after 3 times of gene-radiotherapy with IL-12 and X-irradiation. Immunologic studies showed a significant increase in CTL and NK cytolytic activity (P<0.05-0.001) and an up-regulated secretion of IFN-γ and TNF-α (P<0.01-0.001). Moreover, the expression of mIL-12 in B16 melanoma cells of the treated tumor-bearing mice was found to be higher than that of control. Conclusion pNEgr-mIL-12 plasmid combined with X-irradiation can increase tumor control and the mechanism of increased tumor inhibition is related to the enhancement of anticancer immunity in tumor-bearing mice.
In vitro Study on Role of Hsp70 Expression in DNA Damage of Human Embryonic Lung Cells Exposed to Benzo[a]pyrene
2004, 17(2): 144-152.
Objective Benzo[a]pyrene (B[a]P), a ubiquitous environmental pollutant, is a potent procarcinogen and mutagen that can elicit tumors, leading to malignancy. Heat shock proteins (Hsp) have been shown to protect cells against damages caused by various stresses including exposure to numerous chemicals. Whether Hsps, or more specifically Hsp70, are involved in repair of B[a]P-induced DNA damage is currently unknown. Methods We assessed the potential role of the inducible form of Hsp70 in B[a]P-induced DNA damage of human embryonic lung (HEL) cells using immunoblot and the comet assay (i.e., the single cell gel electrophoresis assay). Results Exposure to B[a]P induced a dose-dependent decrease in the level of Hsp70, but a dose-dependent increase in DNA damage both in untreated (control) HEL cells and in cells preconditioned by a heat treatment. Heat preconditioning prior to B[a]P exposure potentiated the effect of B[a]P at a low dose (10 (mol/L), but appeared to be protective at higher doses. There was a negative correlation between Hsp70 level and DNA damage in the non-preheated as well as in the preconditioned cells. Conclusion These data suggest that exposure of HEL cells to B[a]P may induce a dose-dependent reduction in the levels of the inducible Hsp70. The detailed mechanisms for the reduction of Hsp70 levels by B[a]P and the role of Hsp70 in DNA damage under different concentrations of B[a]P remains to be determined.
2004, 17(2): 153-164.
Objective To investigate the anti-HIV effects of ampelopsin and its interaction with HIV-1 coreceptor CXCR4. Methods Through anti-virus experiments in vitro, the inhibitory effect of ampelopsin on HIV-1 infection was verified. Chemotaxis assay was performed to show the ability to induce PBMCs migration by ampelopsin, RANTES and SDF-1(. Fluorescence labelling monoclonal antibody was utilized to observe the interaction of ampelopsin and CXCR4. Mice immunosuppressant model was also established to detail the role ampelopsin played in regulating cellular immunological functions. Results Ampelopsin could protect sensitive cells against HIV-1 infection and dramatically reduce HIV-1 antigen P24 expression. HIV-1SF33 attaching to MT-4 cells was interfered by ampelopsin, and the EC50 was 0.175 mg/mL for cellular protection and 0.024 mg/mL for P24 inhibition. At co-cultivating phase, EC50 was 0.229 mg/mL and 0.197 mg/mL respectively. Furthermore, the EC50 was 0.179 mg/mL and 0.348 mg/mL in acute infection. Human PBMCs migration was induced after being challenged with ampelopsin or chemokines, and synergistic action was observed during co-treatment. Ampelopsin alone resulted in maximal chemotaxis at 1 mg/mL. HIV-1 co-receptor CXCR4 on the surface of PBMCs was decreased by internalization, which indicated the effect of ampelopsin on CXCR4. About 70% CXCR4 was reduced by ampelopsin at 1 mg/mL. Ampelopsin also augmented cellular immunological functions in immunosuppressive mice. Conclusion Ampelopsin displays a strong inhibitive role during HIV-1 absorption, incubation and acute infection. These results are coincident with its immune enhancement.
Environmental and Health Effects Associated With Harmful Algal Bloom and Marine Algal Toxins in China
2004, 17(2): 165-176.
The frequency and scale of Harmful Algal Bloom (HAB) and marine algal toxin incidents have been increasing and spreading in the past two decades, causing damages to the marine environment and threatening human life through contaminated seafood. To better understand the effect of HAB and marine algal toxins on marine environment and human health in China, this paper overviews HAB occurrence and marine algal toxin incidents, as well as their environmental and health effects in this country. HAB has been increasing rapidly along the Chinese coast since the 1970s, and at least 512 documented HAB events have occurred from 1952 to 2002 in the Chinese mainland. It has been found that PSP and DSP toxins are distributed widely along both the northern and southern Chinese coasts. The HAB and marine algal toxin events during the 1990s in China were summarized, showing that the HAB and algal toxins resulted in great damages to local fisheries, marine culture, quality of marine environment, and human health. Therefore, to protect the coastal environment and human health, attention to HAB and marine algal toxins is urgently needed from the environmental and epidemiological view.
Interaction and Relationship Between Angiotensin Converting Enzyme Gene and Environmental Factors Predisposing to Essential Hypertension in Mongolian Population of China
2004, 17(2): 177-186.
Objective To investigate the association of specific functional gene ACE (I/D) variants of the renin-angiotensin system with essential hypertension (EH) and interaction between ACE (I/D) gene and risk factors for EH in a genetically homogenous Mongolia rural population of China. Methods Individuals (n=1099) were recruited from general population of Kezuohouqi Banner in Inner Mongolian Autonomous Region. Results The association was found between ACE genotype DD plus ID and EH, with an interaction between ACE genotype DD plus ID and cigarette smoking in an additive model. Cigarette smoking index and ACE gene showed a low exposure-gene (LEG) effect on EH, with interaction indices from 7.10 to 1.16. Interaction between ACE genotype DD plus ID and alcohol drinking on EH appeared an additive model. Alcohol drinking index and ACE gene showed a low exposure-gene (LEG) effect on EH, with interaction indices from 1.66 to 1.09. BMI and ACE gene showed a low exposure-gene (LEG) effect on EH, with interaction indices from 6.15 to 2.49. Interactions between ACE genotype and WHR on EH showed a multiplicative model. In a short, there was an interaction between ACE gene and cigarette smoking, alcohol drinking and BMI on EH, especially in a low dose-exposure effect. Conclusion It is important for individuals who carry ACE D allele gene to prevent EH, and furthermore, to prevent and control coronary heart disease, in a view of population-based prevention.
2004, 17(2): 187-195.
Objective To investigate the possibility of using bioaugmentation as a strategy for remediating quinoline-contaminated soil. Methods Microorganisms were introduced to the soil to assess the feasibility of enhancing the removal of quinoline from quinoline-contaminated soil. Slurry-phase reactor was used to investigate the bioremediation of quinoline-contaminated soil. HPLC (Hewlett-Packard model 5050 with an UV detector) was used for analysis of quinoline concentration. Results The biodegradation rate of quinoline was increased through the introduction of Burkholderia pickettii. Quinoline, at a concentration of 1 mg/g soil, could be removed completely within 6 and 8 hours with and without combined effect of indigenous microbes, respectively. Although the indigenous microbes alone had no quinoline-degrading ability, they cooperated with the introduced quinoline-degrader to remove quinoline more quickly than the introduced microbes alone. Bioaugmentaion process was accelerated by the increase of inoculum size and bio-stimulation. The ratio of water to soil in slurry had no significant impact on bioremediation results. Conclusion Bioaugmetation is an effective way for bioremediation of quinoline-contaminated soil.
2004, 17(2): 196-202.
Objective To study the relationship between drinking environment, attitudes and situation and alcohol-related health problems. Methods A sample of 2327 respondents was randomly collected from Wuhan, Hubei Province in China by a face-to-face interview. The structural equation modeling analysis was performed for the data collected. Results Both parents' drinking behaviors and respondents' drinking situation strongly impacted the alcohol-related problems and diseases. Friends' or peers' drinking behaviors influenced the respondents' drinking attitudes and behaviors. Males experienced more alcohol-related problems and diseases than females. Conclusions Comparatively, parents' drinking behaviors exert the most significant influence on drinkers. Therefore, it is beneficial to restrict parents' drinking behaviors for the offsprings and the whole society, and an intensive professional education in early motherhood is also necessary for Chinese women.
Association of HLA-B Alleles With Human Immunodeficiency Virus Type 1 Infection in the Yi Ethnic Group in Sichuan Province
2004, 17(2): 203-208.
Objective To determine the distribution of HLA-B alleles in the Chinese Yi ethnic group and its association with HIV infection. Methods One hundred and six unrelated healthy HIV negative and 73 HIV positive Chinese Yi ethnic individuals were typed by PCR-SSP. Results The frequency of alleles B*07, B*35, and B*46 were increased in HIV-1-positive subjects, whereas the alleles B*55, B*44 and B*78 were absent in the HIV-infected persons studied. The B*46 allele was present in a significantly higher gene frequency among HIV-1-positive individuals (P=0.02, OR=3.32, 95% CI=1.13-9.78) compared with control subjects. Conclusion HLA-B*46 may be associated with its susceptibility to HIV-1 infections.
2004, 17(2): 209-216.
Objective To evaluate the potential implications of the genetic variability of angiotensin converting enzyme, angiotensinogen and angiotensinⅡtype 1 receptor gene for essential hypertension in Tibetan. Methods A case-control study was conducted in 173 hypertensive individuals and 193 individuals with normal blood pressure. Multiple logistic regression analyses were used to estimate the risks of developing hypertension for different genotypes, and haplotype analyses of the angiotensinogen gene were used to determine the association between two-locus angiotensinogen gene polymorphisms and hypertension. Results As to the risk to high blood pressure and high systolic pressure, women with MM genotype were 7.7 (95% CI: 1.3-20.5) and 8.7 (95% CI: 1.8-20.1) times higher than those with TT genotype after adjustment for age and body mass index. Haplotype frequencies for M235T and G-6A were significantly different between hypertensive individuals and controls, which indicated an association of angiotensinogen gene haplotypes with hypertension, and a significant association of 235T/-6A haplotype with hypotensive effect. Conclusion Our results suggest that angiotensinogen gene 235MM is a predictor for hypertension development in Tibetan women but not in men, and may exert its hypertensive effect on linkage disequilibrum with a possible function locus of G-6A.
2004, 17(2): 217-222.
Objective To investigate the effects of fluoride on lipid peroxidation, DNA damage and apoptosis in human embryo hepatocyte L-02 cells. Methods Lipid peroxide (LPO) level, reduced glutathione (GSH) content, DNA damage, apoptosis, and cell cycle analysis were measured after in vitro cultured L-02 cells were exposed to sodium fluoride at different doses (40 μg/mL, 80 μg/mL, and 160 μg/mL) for 24 hours. Results Fluoride caused an increase of LPO levels and a decrease of GSH content in L-02 cells. There appeared to be an obvious dose-effect relationship between the fluoride concentration and the observed changes. Fluoride also caused DNA damage and apoptosis and increased the cell number in S phase of cell cycle in the cells tested. There was a statistically significant difference in DNA damage and apoptosis when comparing the high dose of fluoride treated cells with the low dose of fluoride treated cells. Conclusion Fluoride can cause lipid peroxidation, DNA damage, and apoptosis in the L-02 cell experimental model and there is a significant positive correlation between fluoride concentration and these pathological changes.
2004, 17(2): 223-233.
Objective To investigate whether acute dipterex poisoning (ADP) may cause oxidative stress and free radical damage in the bodies of acute dipterex poisoning patients (ADPPs), and to explore the mechanisms by which ADP may cause oxidative stress and free radical damage. Methods Fifty ADPPs and fifty healthy adult volunteers (HAVs) whose ages, gender and others were matched with the ADPPs were enrolled in a randomized controlled study, in which concentrations of nitric oxide (NO), vitamin C (VC), vitamin E (VE) and (-carotene ((-CAR) in plasma as well as concentration of lipoperoxide (LPO), and activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX) and acetylcholinesterase (AChE) in erythrocytes were determined by spectrophotometric analytical methods. Results Compared with the average values of experimental parameters in the HAVs group, the average values of plasma NO and erythrocyte LPO in the ADPPs group were significantly increased (P<0.0001), while those of plasma VC, VE and β-CAR as well as erythrocyte SOD, CAT, GPX and AChE in the ADPPs group were significantly decreased (P<0.0001). Bivariate correlation analysis and partial correlation analysis suggested that when NO and LPO values were increased, and VC, VE, (-CAR, SOD, CAT and GPX values were decreased in the ADPPs, AChE value was decreased gradually in the ADPPs (P<0.001-0.0001). Reliability analysis of experimental parameters reflecting oxidative stress and free radical damage in the ADPPs showed that the reliability coefficient (8 items) alpha=0.6909, and the standardized item alpha=0.8574. Conclusion The findings in the present study suggest that ADP can cause oxidative stress and free radical damage, and inhibit markedly erythrocyte acetylcholinesterase activity in ADPPs.