2006 Vol. 19, No. 6

Select articles
Influences of Copper Speciation on Toxicity to Microorganisms in Soils
2006, 19(6): 409-413.
Objective To investigate the relationship between copper speciation and microbial features (microbial communities and copper tolerance level) in order to determine the adverse effect of different forms of Cu on microorganisms. Methods Tessier's sequential extraction procedure was used to qualify the different Cu forms (exchangeable, carbonate bound, Fe/Mn oxide bound, residue and organic matter bound), and the copper tolerance level (expressed as IC50, influence concentration) was measured by the plate-count method. Results By simple correlation analysis, the IC50 was positively correlated with the concentration of exchangeable Cu (R2=0.8204), while weakly correlated with other forms of Cu. Conclusion The bacterial community tolerance increases in the copper-contaminated soil while sensitive bacteria decrease in the copper-contaminated soils. The exchangeable Cu exerts high toxicity to microbial communities.
Temperature-Induced Stress on Growth and Expression of Hsp in Freshwater alga Scenedesmus quadricauda
2006, 19(6): 414-421.
Objective To investigate the impact of various levels of sublethal temperature (26℃, 31℃, 33℃, 36℃, and 39℃) on growth and heat shock protein (hsp) expression in freshwater green alga Scenedesmus quadricauda. Methods Impact of selected levels of temperature on growth rate (based on optical density), population count, chlorophyll-a and biomass of the alga was evaluated in artificial growth medium for 19 days. To determine the induction of hsp in the alga, it was exposed to selected temperature levels for 3 h and further kept for 6 h at culturing condition at 26℃. Induction of hsp was confirmed by immuno-detection followed by SDS-polyacrylamide gel electrophoresis. Results The selected growth parameters such as growth rate, population count, chlorophyll-a and biomass were reduced significantly (P<0.001) at 39℃. However, hsp 70expression was observed only at 39℃. Conclusion Temperature up to 36℃ may be considered as the limit of safe exposure for thermal stress for the alga Scenedesmus quadricauda.
Fauna-associated Changes in Chemical and Biochemical Properties of Soil
2006, 19(6): 422-426.
Objective To study the impacts of abundance of woodlice, termites, and mites on some functional aspects of soil in order to elucidate the specific role of soil fauna in improving soil fertility in desert. Methods Fauna-rich sites were selected as experimental sites and adjacent areas were taken as control. Soil samples were collected from both sites. Soil respiration was measured at both sites. The soil samples were sent to laboratory, their chemical and biochemical properties were analyzed.Results Woodlice showed 25% decrease in organic carbon and organic matter as compared to control site. Whereas termites and mites showed 58% and 16% decrease in organic carbon and organic matter. In contrast, available nitrogen (nitrate and ammonical both) and phosphorus exhibited 2-fold and 1.2-fold increase, respectively. Soil respiration and dehydrogenase activity at the sites rich in woodlice, termites and mites produced 2.5-, 3.5- and 2-fold increases, respectively as compared to their control values. Fauna-associated increase in these biological parameters clearly reflected fauna-induced microbial activity in soil. Maximum decrease in organic carbon and increase in nitrate-nitrogen and ammonical-nitrogen, available phosphorus, soil respiration and dehydrogenase activity were produced by termites and minimum by mites reflecting termite as an efficient soil improver in desert environment. Conclusion The soil fauna-associated changes in chemical (organic carbon, nitrate-nitrogen, ammonical-nitrogen, phosphorus) and biochemical (soil respiration, dehydrogenase activity) properties of soil improve soil health and help in conservation of desert pedoecosystem.
DNA Damage Caused By Pesticide-contaminated Soil
2006, 19(6): 427-431.
Objective To determine the DNA damaging potential and the genotoxicity of individual compounds in pesticide contaminated soil. Methods In the present study, DNA damaging potential of pesticide-contaminated soil and the genotoxicity of individual compounds present in the soil were assessed using fluorimetric analysis of DNA unwinding assay. Results The contaminated soil sample showed 79% (P<0.001) of DNA strand break, whereas technical grade of major carbaryl and α-naphthol constituents of the contaminated soil showed 64% (P<0.01) and 60% (P<0.02) damage respectively. Conclusion Our results indicate that the toxicity caused by contaminated soil is mainly due to carbaryl and α -napthol, which are the major constituents of the soil sample analyzed by GC-MS.
Structural and Functional Changes of Immune System in Aging Mouse Induced by D-Galactose
2006, 19(6): 432-438.
Objective To investigate the role of D-galactose, especially in the structural and functional changes of the immune system in aging. Methods Serum levels of advanced glycation end-products (AGE) were determined by ELISA method. Ultra-structures of thymus and spleen were detected by transmission electron microscopy. MTT method was used to determine the lymphocyte proliferation. IL-2 activity was determined by bioassay. Northern blot was used to detect the IL-2 mRNA levels. Results Serum AGE levels of D-galactose- (P<0.01) and AGE-treated (P<0.05) mice (n=8) were increased significantly. The ultra-structures of thymus and spleen in D-galactose- and AGE-treated mice showed regressive changes similar to those in the aged control group. The lymphocyte mitogenesis and IL-2 activity of spleen were also decreased significantly (P<0.01, n=8).The change of IL-2 activity shown by Northern blot resulted from the change of mRNA expression. The AGE plus aminoguanidine group, however, showed no significant change in these parameters in comparison with the young control group (P<0.01 or P<0.05, n=8). Conclusion D-galactose and AGE lead to a mimic regression change of aging in the immune system in vivo.
Effects of Selenium and Zinc on Renal Oxidative Stress and Apoptosis Induced by Fluoride in Rats
2006, 19(6): 439-444.
Objective To study the effects of selenium and zinc on oxidative stress, apoptosis, and cell cycle changes in rat renal cells induced by fluoride. Methods Wistar rats were given distilled water containing sodium fluoride (50 mg/L NaF) and were gavaged with different doses of selenium-zinc preparation for six months. Four groups were used and each group had eight animals (four males and four females). Group one, sham-handled control; group two, 50 mg/L NaF; group three, 50 mg/L glutathione peroxidase (GSH-Px), kidney superoxide dismutase (SOD), and the levels of malondialdehyde (MDA) and glutathione (GSH) in the kidney were measured to assess the oxidative stress. Kidney cell apoptosis and cell cycle were detected by flow cytometry. Results NaF at the dose of 50 mg/L increased excretion of fluoride in urine, promoted activity of urine γ -glutamyl transpeptidase ( γ -GT), inhibited activity of serum GSH-PX and kidney SOD, reduce kidney GSH content, and increased kidney MDA. NaF at the dose of 50 mg/L also induced rat renal apoptosis, reduced the cell number of G2/M phase in cell cycle, and decreased DNA relative content significantly. Selenium and zinc inhibited effects of NaF on oxidative stress and apoptosis, promoted the cell number of G2/M phase in cell cycle, but failed to increase relative DNA content significantly. Conclusion Sodium fluoride administered at the dose of 50 mg/L for six months induced oxidative stress and apoptosis, and changes the cell cycle in rat renal cells. Selenium and zinc antagonize oxidative stress, apoptosis, and cell cycle changes induced by excess fluoride.
Severe Acute Respiratory Syndrome-Retrospect and Lessons of 2004 Outbreak in China
2006, 19(6): 445-451.
Objective To summarize lessons learned from an outbreak of severe acute respiratory syndrome (SARS) in China during the spring of 2004. Methods Data of SARS cases were officially reported by Beijing Municipal Center for Disease Control and Prevention (BCDC) and Anhui Provincial Center for Disease Control and Prevention (APCDC) and results of epidemiological investigations were collected and analyzed. Results Three generations of 11 cases of SARS were identified during the outbreak. Initial two cases were most likely to be infected in Diarrhea Virus Laboratory of National Institute of Virology, China Centers for Disease Control and Prevention and main mode of transmission was direct contact with SARS patients. Delay in detecting initial case resulted in spread of the illness at hospitals and communities with two generations of secondary cases. Conclusions SARS outbreak in 2004 has yielded following lessons for public health globally. (1) Lab bio-safety programs should be made and should be strictly abided by. Studies in highly pathogenic viruses such as SARS coronavirus should be utmost cautious. (2) Management systems of occupational exposure to virus and disease surveillance need to be strengthened to take all risk factors into account so as to detect potential patients with infectious disease as early as possible.
Relationship Between Polymorphism of Cystathionine beta Synthase Gene and Congenital Heart Disease in Chinese Nuclear Families
2006, 19(6): 452-456.
Objective To study the relationship between polymorphism of cystathionine beta synthase (CBS) gene and development of congenital heart disease (CHD). Methods One hundred and twenty-seven CHD case-parent triads were recruited from Liaoning Province as patient group, and 129 healthy subjects without family history of birth defect were simultaneously recruited as control group together with their biological parents. For all subjects the polymorphism of CBS gene G919A locus was examined by PCR-ARMS method. Results The frequencies of three genotypes (w/w, w/m, and m/m) in control group were 27.2%, 58.4%, and 14.4%, respectively, with no significant difference in gender. A significant difference in the allele frequency was found between CHD patients and controls, the wild allele frequency was 67.9% in patients and 55.7% in controls.CHD parents' genotype distribution was significantly different from that in controls. Further comparison of each type of CHD showed that genotype frequencies in several CHD subtypes were significantly different from those in their corresponding controls. The results of TDT analysis showed that no allele transmission disequilibrium existed in CHD nuclear families.Conclusions CBS gene G919A mutation is associated with the development of CHD, and the mutated allele may decrease the risk of CHD.
QSARS for Acute Toxicity of Halogenated Benzenes to Bacteria in Natural Waters
2006, 19(6): 457-460.
Objective To measure the acute toxicity of halogenated benzenes to bacteria in natural waters and to study quantitative relationships between the structure and activity of chemicals. Methods The concentration values causing 50% inhibition of bacteria growth (24h-IC50) were determined according to the bacterial growth inhibition test method. The energy of the lowest unoccupied molecular orbital and the net charge of carbon atom of 20 halogenated benzenes were calculated by the quantum chemical MOPAC program. Results The log1/IC50 values ranged from 4.79 for 2,4-dinitrochlorobenzene to 3.65 for chlorobenzene. A quantitative structure-activity relationship model was derived from the toxicity and structural parameters: log1/IC50 =-0.531(ELUMO)+1.693(Qc)+0.163(logP)+3.375. This equation was found to fit well (r2=0.860, s=0.106), and the average percentage error was only 1.98%. Conclusion Halogenated benzenes and alkyl halogenated benzenes are non-polar narcotics, and have hydrophobicity-dependent toxicity. The halogenated phenols and anilines exhibit a higher toxic potency than their hydrophobicity, whereas 2,4-dinitrochlorobenzene is electrophile with the halogen acting as the leaving group.
Characteristics and Seasonal Variations of PM2.5, PM10,and TSP Aerosol in Beijing
2006, 19(6): 461-468.
Objective To investigate the seasonal characteristics and the sources of elements and ions with different sizes in the aerosols in Beijing. Methods Samples of particulate matters (PM2.5), PM10, and total suspended particle (TSP)aerosols were collected simultaneously in Beijing from July 2001 to April 2003. The aerosol was chemically characterized by measuring 23 elements and 18 water-soluble ions by inductively coupled plasma-atomic emission spectroscopy (ICP-AES) and ion chromatography (IC), respectively. Results The samples were divided into four categories: spring non-dust, spring dust, summer dust, and winter dust. TSP, PM10, and PM2.5 were most abundant in the spring dust, and the least in summer dust. The average mass ratios of PM>10, PM2.5-10, and PM2.5 to TSP confirmed that in the spring dust both the large coarse (PM>10) and fine particles (PM2.5) contributed significantly in summer PM2.5, PM2.5-10, and PM>10 contributed similar fractions to TSP, and in winter much PM2.5. The seasonal variation characteristics of the elements and ions were used to divide them into four groups: crustal, pollutant, mixed, and secondary. The highest levels of crustal elements, such as Al, Fe, and Ca, were found in the dust season, the highest levels of pollutant elements and ions,such as As, F, and C1-, were observed in winter, and the highest levels of secondary ions (SO42-, NO3-, and NH4+) were seen both in summer and in winter. The mixed group (Eu, Ni, and Cu) showed the characteristics of both crustal and pollutant elements. The mineral aerosol from outside Beijing contributed more than that from the local part in all the reasons but summer, estimated using a newly developed element tracer technique.
Ethnic Differences in Body Mass Index and Prevalence of Obesity in School Children of Urumqi City, Xinjiang, China
2006, 19(6): 469-473.
Objective To investigate the prevalence of obesity and distribution of body mass index (BMI) in school children of four ethnic groups in Urumqi, Xinjiang, China. Methods A total of 55 508 school children of Han, Hui, Uygur and Kazak nationalities aged 8-18 years were selected by a cluster sampling from a districts of Urumqi City for anthropometric measurement and demographic survey. Prevalence of obesity and overweight and distribution of body mass index (BMI) by gender, age, and nationality were analyzed and compared. Cutoff points of BMI for defining obesity and overweight were based on the proposal set by the Working Group on Obesity in China (WGOC) to assess age-, gender- and nationality-specific prevalence of obesity and overweight. Results Prevalence of obesity was 5.34%, 6.78%, 3.39 %, and 1.22% for boys and 2.61%, 1.83%, 1.78%, and 1.40% for girls of Han, Hui, Uygur and Kazak nationalities, respectively. Prevalence of obesity tended to decrease with age overall, whereas that of overweight increased with age in Han children. Conclusions Prevalence of obesity in school children in Urumqi varies with their nationalities and is lower than that of an average national level and a level of western countries. Obesity is more prevalent in boys than in girls of Urmuqi overall, which is just the opposite in Kazak children. Han boys and Hui girls have the highest prevalence of obesity and Kazak boys and girls have the lowest ones. Prevalence of obesity decreases with age, but that of overweight shows a different trend.
DHA Depletion in Rat Brain Is Associated With Impairment on Spatial Learning and Memory
2006, 19(6): 474-480.
Objective To examine the effect of docosahexaenoic acid (DHA) deficiency in brain on spatial learning and memory in rats. Methods Sprague Dawley rats were fed with an n-3 fatty acid deficient diet for two generations to induce DHA depletion in brain. DHA in seven brain regions was analyzed using the gas-liquid chromatography. Morris water maze (MWM) was employed as an assessing index of spatial learning and memory in the n-3 fatty acid deficient adult rats of second generation. Results Feeding an n-3 deficient diet for two generations depleted DHA differently by 39%-63% in the seven brain regions including cerebellum, medulla, hypothalamus, striatum, hippocampus, cortex and midbrain. The MWM test showed that the n-3 deficient rats took a longer time and swam a longer distance to find the escape platform than the n-3 Adq group. Conclusion The spatial learning and memory in adult rats are partially impaired by brain DHA depletion.
Increased Oxidative Stress and Damage in Patients With Chronic Bacterial Prostatitis
2006, 19(6): 481-486.
Objective To investigate whether chronic bacterial prostatitis (CBP) increases oxidative stress and damage in patients with CBP, and to explore its possible mechanism. Methods Eighty patients with CBP and 80 healthy adults as controls were enrolled in a case-control study, in which levels of nitric oxide (NO), vitamin C (VC), and vitamin E (VE) in plasma, as well as malondialdehyde (MDA), activities of superoxide dismutase (SOD), and catalase (CAT) in erythrocytes were determined by spectrophotometry. Results Compared with the average values of NO, VC, VE, MDA, SOD, and CAT in the healthy control group, those of plasma NO and erythrocyte MDA in the CBP group were significantly increased (P<0.001), and those of plasma VC and YE as well as erythrocyte SOD and CAT in the CBP group were significantly decreased (P<0.001). Findings from partial correlation analysis for course of the disease and NO, VC, VE, MDA, SOD, and CAT in 80 patients with CBP, adjusted for age, suggested that with prolonged course of the disease, values of NO and MDA were gradually increased (P<0.001), and those of VC, VE, SOD, and CAT were gradually decreased (P<0.05-0.001). The findings from stepwise regression analysis for course of the disease and NO, VC, VE, MDA, SOD, and CAT in CBP group suggested that the model of stepwise regression was Y = -19.1160 +0.3112MDA + 0.0337NO, F = 22.1734, P<0.001, r = 0.6045, P<0.001. The findings from the reliability analysis for VC, VE, SOD, CAT, NO, and MDA in the CBP group showed that the reliability coefficients' alpha (6 items) was 0.7195, P<0.0001, and the standardized item alpha was 0.9307, P<0.0001. Conclusion There exist increased oxidative stress and damage induced by chronic bacterial prostatitis in patients, and such a phenomenon is closely related to the course of disease.
Anticlastogenic Effect of Redistilled Cow's Urine Distillate in Human Peripheral Lymphocytes Challenged With Manganese Dioxide and Hexavalent Chromium
2006, 19(6): 487-494.
Objective To study the anticlastogenic effect of redistilled cow's urine distillate (RCUD) in human peripheral lymphocytes (HLC) challenged with manganese dioxide and hexavalent chromium. Methods The anticlastogenic activity of redistilled cow's urine distillate was studied in human polymorphonuclear leukocytes (HPNLs) and human peripheral lymphocytes in vitro challenged with manganese dioxide and hexavalent chromium as established genotoxicants and clastogens which could cause induction of DNA strand break, chromosomal aberration and micronucleus. Three different levels of RCUD: 1 μL/mL, 50 μL/mL and 100μL/mL, were used in the study. Results Manganese dioxide and hexavalent chromium caused statistically significant DNA strand break, chromosomal aberration and micronucleus formation, which could be protected by redistilled cow's urine distillate. Conclusion The redistilled cow's urine distillate posseses strong antigenotoxic and anticlastogenic properties against HPNLs and HLC treated with Cr+6 and MnO2. This property is mainly due to the antioxidants present in RCUD.
The Need and Its Influence Factors for Community-based Rehabilitation Services for Disabled Persons in One District in Beijing
2006, 19(6): 495-497.
Purpose To explore the needs for basic community-based rehabilitation services for disabled persons in Xuanwu District, Beijing, China, and to identify factors which influence disabled persons to accept rehabilitation services. Method One hundred and eight disabled persons were selected by systematic sampling and simple random sampling to assess their needs for community-based rehabilitation services. Results Of the interviewees, 57.4% needed the community-based rehabilitation services, but only 13.9% took advantage of it. The main factors influencing the interviewees to accept these services were cost (P<0.05), knowledge about rehabilitation medicine (P<0.05); and the belief in the therapeutic benefit of the community-based rehabilitation service (P<0.05). Conclusion A considerable gap exists between the supply of community-based rehabilitation services in Beijing and the needs for these services by disabled residents underscoring the need for improved availability, and for additional research.