2007 Vol. 20, No. 4

Select articles
Field Evaluation of Alternative Testing Strategies for the Detection of HIV Infection in Beijing
2007, 20(4): 265-268.
Objective To identify a cost-efficient alternative antibody testing strategy for screening and confirmation of HIV infection by rapid simple tests (RSTs) and enzyme-linked immunosorbent assays (ELISAs). Methods Four RSTs (RST1,RST2, RST3, and RST4 ) and five ELISAs (ELISA1, ELISA2, ELISA3, ELISA4, and ELISA5) were evaluated in two phases by using banked and serum specimens prospectively collected at regional hospitals and voluntary counseling and testing (VCT)centers in Beijing. A total of 200 banked serum specimens were included in the first phase, including 62 HIV-positive, 127 HIV-negative and 11 indeterminate specimens. All specimens were tested by four RSTs and five ELISAs respectively. The second phase involved prospective testing of 389 routine specimens, including 92 HIV-positive, 287 HIV-negative, and 10 indeterminate specimens. All the specimens were tested by two RSTs (RST2 and RST4) and three ELISAs (ELISA1, ELISA3,and ELISA4), which were selected for their respective excellent sensitivity and/or specificity. Western blot (WB) was used as a gold standard for confirming the reactivity of all the specimens. Results Sensitivity, specificity, and efficacy were calculated for each assay in two phases. In the first phase, four assays (ELISA4, RST2, RST3, and RST4) had a specificity of 100%. For the determination of efficacy, ELISA4, RST2, and RST4 were selected in the second phase. ELISA1 and ELISA3 which have a sensitivity of 95.9% and 93.2% respectively also entered this phase. In the second phase, all the five assays (ELISA1, ELISA3, ELISA4, RST2, and RST4) had a sensitivity and specifity of over 90%. ELISA1 had a sensitivity of 99% and ELISA4 a specificity of 99%. Conclusion The sensitivity ELISA1 and the specificit of ELISA4 are comparable to ELISA/WB standard strategy. Application of this alternative testing strategy provides a cost-effective method for determining HIV prevalence in Beijing.
Effects of Photodynamic Therapy on the Ultrastructure of Glioma Cells
2007, 20(4): 269-273.
Objective To study the change in ultrastructure of C6 glioma cells after photodynamic therapy (PDT), to compare morphological differences in necrosis and apoptosis before and after PDT treatment, and to evaluate the effect of photodynamic therapy on the blood brain tumor barrier (BTB) of C6 glioma. Methods The model was produced by transplanting C6 glioma cells cultured in vitro using Peterson method into the caudate nuclei of Wister rats. The experiment group received PDT for two weeks after the operation. The sub-cellular structure, blood-brain-barrier (BBB) and BTB in both groups were observed under electron microscope. Results Apoptosis in different phases and necrosis could be observed in some C6 glioma cells.Swelling occurred on the ultrastructure of cellular organs such as mitochondria and endoplasmic reticulum in most of the cells.Damage to the BTB, reduction of the number of cellular organs in endothelial cells of the capillary blood vessels, stretch of the tight junction, and enlargement of the gaps between endothelial cells were also seen in the experiment group. Meanwhile,limited impact on the normal sub-cellular structures and BBB was observed. Conclusion PDT could induce apoptosis and necrosis of C6 glioma cells due to the damage to the ultrastructure of mitochondria and endoplasmic reticulum. The weakened function of C6 glioma BTB initiated by PDT makes it possible to perform a combined therapy of PDT and chemotherapy for glioma.
Screening and Characterization of a Bioflocculant Produced by Aeromonas sp.
2007, 20(4): 274-278.
Objective To isolate the bioflocculant-producing bacteria from activated sludge and investigate the flocculating characteristics of the newly isolated bioflocculant. Methods Bacteria were screened from activated sludge samples to isolate bioflocculant-producing bacteria. Flocculating activity was used as a measure of the flocculating capability of the bioflocculant.Results A novel bioflocculant-producing bacterium was isolated, which was identified to belong to genus Aeromonas and named as Aeromonas sp. N11. Flocculating activity increased in the presence of K+, Na+, or Ca2+. The highest flocculating activities for kaolin suspension were obtained in acidic pH ranges, and optimum pHs for it were 3.0, 4.0, and 5.0 with 1 mmol/L K+, Ca+, and Na+ present, respectively. The highest flocculating activities for soil suspension were observed at pH 8.0. The bioflocculant had a good flocculating activity and could achieve a flocculating activity of 92.4% for kaolin suspension at a Conclusion The bioflocculant produced by Aeromonas sp. N11 has strong flocculating activity and high stability, which affords high possibility of its practical use.
Comparison of Clinic and Ambulatory Blood Pressure in Response to Antihypertensive Drugs in Chinese Patients
2007, 20(4): 279-283.
Objective To compare the difference between 24-h ambulatory blood pressure (ABP) and trough clinic blood pressure (CBP) after 8 weeks of therapy. Methods The study used meta-regression analysis to summarize three randomized,double-blind, active controlled trials in order to compare the difference between the magnitude of the reduction in 24-h average ABP and CBP Patients. Chinese patients with seated diastolic blood pressure (SDBP) 95-115 mmHg and ambulatory diastolic blood pressure (ADBP) ≥85 mmHg. Results The average age of 126 patients was 47.7±8.3 years, ranging from 25 to 67 (95 males and 31 females). All regimens reduced 24-h ABP and CBP after 8 weeks of treatment. In the 126 patients the baseline 24-h SBP and DBP values (142.7/94.4 mmHg) were markedly lower than those for clinic values (152.6/102.6 mmHg;P<0.0001). Similarly, the 24-h SBP and DBP values (132.7/87.7 mmHg) in week 8 were markedly lower than the clinic values (138.9/92.7 mmHg; P<0.0001). The differences between the treatment-induced reductions in 24-h ABP and CBP were statistically significant (the difference was 3.7/3.3 mmHg for SBP/DBP, P=0.0069/P<0.0001). Conclusion All regimens significantly reduced seated CBP and ABP. The effect of antihypertensive treatment was greater on CBP than that on ABP,suggesting that assessment on effectiveness of an antihypertensive treatment using CBP readings only has to be carefully interpreted, and a more systematic application of ABP monitoring should be adopted.
Carboxylic Esterase and Its Associations With Long-term Effects of Organophosphorus Pesticides
2007, 20(4): 284-290.
Objective To examine a) the effect of organophosphorus pesticide exposure on activity of carboxylic esterases, namely butyrylcholinesterase (BChE), carboxylesterase (CarbE) and paraoxonase (PonE); and b) the association of polymorphisms of BChE and PonE with individual genetic susceptibility to organophosphorus pesticide exposure. Methods A cross-sectional study was conducted in 75 workers exposed to organophosphorus pesticides and 100 non-exposed controls. The serum activity of these enzymes was measured. Variant forms of BCHE-K, PON-192, and PON-55 were detected. A symptom score was developed as a proxy measure of clinical outcomes. Results Activities of both BChE and CarbE were lower in exposed exposed workers with BCHE-K genotype UU (61 cases), genotype UK (12 cases) and genotype KK (2 cases) was 105.05, 84.42 activity in the exposed workers with PON-192 genotype BB (37), genotype AB (27) and genotype AA (11) was 116.8, 91.2, and 9.20. The symptom score was the highest in individuals with abnormal homozygote for each of the three gene loci. Conclusions Long-term exposure to organophosphorus pesticides can inhibit BChE and CarbE activity, but exerts no inhibitory effect on PonE activity. Different genotypes of BCHE-K, PON-192, and PON-55 may be related to the severity of adverse health effects of organophosphorus pesticide exposure. Implications of potentially higher susceptibility of workers with mutant homozygotes should be evaluated to reduce health risks.
Degradation of Acenaphthene by Ozone
2007, 20(4): 291-294.
Objective To investigate the oxidation of acenaphthene (Ace), a polycyclic aromatic hydrocarbon (PAH) with a saturated C-C bond by ozone and to characterize the intermediate products of ozonation. Methods Ozone was generated from filtered dry oxygen by an ozone generator and continually bubbled into a reactor containing 1g/L Ace dissolved in an acetonitrile/water solvent mixture (90/10, v/v) at a rate of 0.5 mg/s. HPLC was used to analyze the Ace concentration. Total organic carbon (TOC) was used to measure the amount of water soluble organic compounds. GC-MS was used to identify the ozonized products. Oxygen uptake rate (OUR) of activated sludge was used to characterize the biodegradability of ozonized products. Results During the ozonation process, Ace was degraded, new organic compounds were produced and these intermediate products were difficult mineralize by ozone, with increasing TOC of soluble organics. The ozonized products were degraded by activated sludge more easily than Ace. Conclusion Ozonation decomposes the Ace and improves its biodegradability. The ozonation combined with biological treatment is probably an efficient and economical way to mineralize acenaphthene in wastewater.
Insulin Expression in Rats Exposed to Cadmium
2007, 20(4): 295-301.
Objectives To investigate the effects of cadmium exposure on insulin expression in rats. Methods Eighteen adult SD assessed. The levels of cadmium and zinc in pancreas, blood and urine glucose, serum insulin and urine NAG (N-acyetyl-β-glucosaminidase) were determined. The gene expressions of metallothionein (MT) and insulin were also measured,and the oral glucose tolerance tests (OGTT) were carried out. Results The contents of cadmium in pancreas in cadmium-treated rats were higher than that in the control group, which was associated with slight increase of zinc in pancreas.not change significantly after cadmium administration, and the UNAG had no change in Cd-treated group. The gene expression the change of the expression of insulin, MT-Ⅰ and MT-Ⅱ genes. Cadmium can influence the biosynthesis of insulin, but does not induce the release of insulin. The dysfunction of pancreas occurs earlier than that of kidney after administration of cadmium.
Power Relation and Condom Use in Commercial Sex Behaviors
2007, 20(4): 302-306.
Objective To explore whether condom use is influenced by power relation in commercial sex behaviors. Methods Variables were designed to measure the power relation in commercial sex behaviors based on the theory of gender and power relation and data were collected from male sexually transmitted diseases (STD) patients and female commercial sex workers (FSWs) working at recreation centers or being detained in a women education center to identify the relationship between condom use and power relation in male and female respondents using bivariate and multiple regression analysis. Results A significant relationship was identified between power relation and female condom use, the higher the score of power relations, the higher frequency the condom use, but no similar result was found in males. Females got a higher score of power relation than males. Conclusions Power relation is one of the factors that influence condom use, which should be considered when relevant theories are used to study the rate of condom use. It is worthwhile exploring the relationship between safe sex and power relation in spouses and regular sex partners when interventions are adopted to prevent HIV/AIDS spreading from high risk groups to the general population.
Inhibitory Effects of Selenium on Telomerase Activity and hTERT Expression in Cadmium-transformed 16HBE Cells
2007, 20(4): 307-312.
Objective To investigate the effects of sodium selenite on telomerase activity and expression of hTERT mRNA in cadmium-transformed 16HBE cells. Methods Telomerase activity and expression of genes were measured after cultured cadmium-transformed 16HBE cells were exposed to sodium selenite at different doses (0.625, 1.25, 2.50, 5.00 μmol/L) for 24 hours. Results Selenium decreased telomerase activity in cadmium-transformed 16HBE cells. There existed an obvious dose-effect relationship between the selenium concentration and these changes. The expression of hTERT and c-myc mRNA also decreased but the expression of mad1 mRNA increased after exposure to selenium for 24 hours. No difference was found in expression of hTRF1 and hTRF2 mRNA after incubated with sodium selenite for 24 hours, compared with control group.Conclusion Selenium inhibits telomerase activity by decreasing hTERT and c-myc mRNA expression and increasing mad1 mRNA expression in cadmium-transformed 16HBE cells and selenium concentration is significantly correlated with these changes.
Comparative Larvicidal Property of Leaf Extract of Chromolaena odorata L (Composidae) and Chlopyrifos (Organophosphorus Compound) on Simulium Larvae
2007, 20(4): 313-316.
Objective To assess the phytochemical properties of Chromoleana odorata in the control of blackflies to help check the problem of environmental pollution from the use of chemical insecticides. Methods Dried pulverized leaves of Chromolaena odorata (100 g) were soaked in distilled water for 24 hours and the extract was filtered, marc pressed and evaporated over water bath. Stock solution of the dried mass (1 g) was concentrated by dissolving in 100 mL of water. Serial dilutions (100 mg/mL, 10 mg/mL, 1 mg/mL, 0.1 mg/mL, 0.01 mg/L, and 0.001 mg/mL) of both the extract and Chlopyrifos (organo phosphorus) were prepared and toxicity was tested on the larvae of Simulium species. Results The chemical compound recorded 100% larval mortality at all concentrations while the plant extract recorded 100% larval mortality in three (100, 10, and 1 mg/mL) of its diluent concentration. The percentage of larval mortality by chemical compound and plant extract was statistically insignificant (t = 0.2456, P>0.05), but the mortality rate was significant within 30 min interval of exposure time (t= 3.756, P<0.05). The LC50 of the plant extract was determined at about 0.001 mg/mL concentration. This showed that the plant extract had an appreciable larvicidal property close to that of the chemical compound. Conclusion This result indicates the usefulness of plant materials in the control of obnoxious insect vectors of mn. It also opens additional approach to the management of environment from toxic chemicals that are non-biodegradable and cause environmental imbalance in the ecosystem.
Rapid Determination of Dopamine and Its Metabolites During in vivo Cerebral Microdialysis by Routine High Performance Liquid Chromatography With Electrochemical Detection
2007, 20(4): 317-320.
Objective To determine dopamine and its metabolites during in vivo cerebral microdialysis by routine high performance liquid chromatography with electrochemical detection. Methods Microdialysis probes were placed into the right striatum of Wistar rat brains and perfused with Ringer's solution at a rate of 1.5 μL/min. A reverse phase HPLC with electrochemistry was used to assay DA, DOPAC, and HVA after cerebral microdialysates were collected every 20 minutes from awake and freely moving rats. In order to identify the reliability of this method, its selectivity, linear range, precision and accuracy were tested and the contents of DA, DOPAC, and HVA in rat microdialysates were determined. Results The standard curve was in good linear at the concentration ranging from 74 nmol/L to 1.5 μmol/L for DOPAC (r2= 0.9996), from 66 nmol/L to 1.3 μmol/L for DA (r2=1.0000) and from 69 nmol/L to 1.4 μmol/L for HVA (r2=0.9992). The recovery of DOPAC (0.30, 0.77, 1.49 μmol/L),DA (0.26, 0.69, 1.32 μmol/L), and HVA (0.27, 0.71, 1.37 μmol/L) was 82.00±1.70%, 104.00±4.00%, 98.70±3.10%;92.30±1.50%, 105.30±2.30%, 108.00±2.00%; 80.00±7.80%, 107.69±8.00%, and 108.66±3.10%, respectively at each concentration. Their intra-day RSD was 3.3%, 3.4%, and 2.5%, and inter-day RSD was 4.2%, 2.3%, and 5.6%, respectively.The mean extracellular concentrations of DOPAC, DA, and HVA in rat brain microdialysates were 10.7, 2.4, and 9.2 μmol/L (n=6), respectively. Conclusion The findings of our study suggested that the simple, accurate and stable method can be applied to basic researches of diseases related to monoamines neurotransmitters by cerebral microdialysis in rats.
Molecular Epidemiological Analysis of Echovirus 19 Isolated From an Outbreak Associated With Hand, Foot, and Mouth Disease (HFMD) in Shandong Province of China
2007, 20(4): 321-328.
Objective To elucidate the genetic characterization and molecular epidemiological features of Echovirus 19 (E19) isolates collected from an outbreak associated with hand, foot and mouth disease (HFMD) in Tai'an city of Shandong Province of China from July to September, 2003. Methods Thirty seven Echovirus 19 isolates were isolated from stool specimens and throat swabs collected during the outbreak, then major capsid (VP1) genomic sequence was determined, and phylogenetic tree was done based on the VP1 sequences among these 37 and other E19 viruses deposited in the Genbank. Also a representative strain named CHN-SD03-TN12 was selected for sequencing of 5'-untranslated regions (5'-UTR). Results The identity rate was about 98.9%-100% among all these 37 El9 viruses. The genetic relationships between these 37 E19 isolates and other strains reported were also depicted. The identity rate was about 78.4%-78.9% compared with E19 reference strain Burke. The substitutions in the sequence of 5'-UTR resulted in changes in the conjectural properties of 5'-UTR of E19 viruses.Conclusion The genetic features of E19 viruses isolated during the outbreak in Shandong Province in 2003 may be associated with a genetic and antigenic drift that changes the virulence of the Shandong isolates, but the molecular changes in Shandong E19 viruses contributing to their phenotype remain to be further illuminated. However, the sequences described in this paper substantiate the changes taken place in capsid VP1 and 5'UTR regions. These substitutions may contribute to their tropism and virulence, and play a significant role in pathogenesis and clinical manifestations of the disease.
Blood Lipid Profile and Prevalence of Dyslipidemia in Chinese Adults
2007, 20(4): 329-335.
Objective To investigate the plasma lipid levels in a national representative sample of subjects and to determine the prevalence of dyslipidemia in the Chinese population. Methods Plasma lipid profile was analyzed using the data obtained during the Chinese national nutrition and health survey (CNHS) in 2002 which involved 14 252 participants at the age of 18 years or older. Results The mean levels of total cholesterol (TC), triglyceride (TG) and high density lipoprotein cholesterol (HDL-C) in the participants were 3.81 mmol/L, 1.10 mmol/L, and 1.30 mmol/L, respectively. In the groups of participants at the age of 18-44 years, 45-59 years, and over 60 years the mean TC level was 3.70 mmol/L, 4.09 mmol/L and 4.21 mmol/L,respectively, and the mean TG level was 07 mmol/L, 1.21 mmol/L, 1.20 mmol/L, 1.29 mmol/L, 1.33 mmol/L, and 1.33 mmol/L,respectively. The prevalence of dyslipidemia in Chinese adults was 18.6% and 22.2% in males and 15.9% in females.Dyslipidemia prevalence was higher in urban districts than in rural areas (21.0% vs. 17.7%). The prevalence of hypercholesterolemia, hypertriglyceridemia, and low HDL cholesterol was 2.9%, 11.9%, and 7.4% respectively among the participants. Conclusion Dyslipidemia has become one of the important health risk factors in the Chinese population. There is no significantly difference in the prevalence of dyslipidemia between the groups of participants at the age of 45-59 years and over 60 years. This study provides important lipid profile data for policy making and guideline development for the prevention of dyslipidemia in the Chinese population.
Inhibition of Excitatory Amino Acid Efflux Contributes to Protective Effects of Puerarin Against Cerebral Ischemia in Rats
2007, 20(4): 336-342.
Objective To investigate whether the protective effects of puerarine (Pur) against cerebral ischemia is associated with depressing the extracellular levels of amino acid transmitters in brain of rats. Methods Male Sprague-Dawley rats were subjected to transient middle cerebral artery occlusion (MCAO) for 60 min followed by 24 h reperfusion. Pur (50, 100 mg/kg,i.p.) was administered at the onset of MCAO. The infarct rate and edema rate were detected on TTC (2,3,5-triphenyltetrazolium chloride)-stained coronal sections. The extracellular levels of amino acid transmitters were monitored in striatum of rats with ischemic/reperfusion injury using in vivo microdialysis technique. Furthermore, the protective effects of Pur against glutamate-induced neurotoxicity were detected. Glutamate-induced apoptotic and necrotic cells in hippocampus were estimated by flow cytometric analysis of Annexin-Ⅴ and PI labeling cells. Results Pur (100 mg/kg) significantly decreased infarct size by 31.6% (P<0.05), reduced edema volume (P<0.05), and improved neurological functions (P<0.05) following MCAO. In these rats, the ischemia-induced extracellular levels of aspartate (Asp), glutamate (Glu), γ-aminobutyric acid (GABA), and taurine (Tau) were significantly reduced in striatum of vehicle-treated animals by 54.7%, 56.7%, 75.8%, and 68.1% (P<0.01 and P<0.05). Pur reduced the peak values of Glu and Asp more obviously than those of GABA and Tau, and the rate of Glu/GABA during MCAO markedly decreased in Pur-treated MCAO rats, compared with the vehicle-treated MCAO rats.Meanwhile, apoptosis and necrosis induced by Glu in cultured hippocampal neurons were significantly reduced after Pur treatment. Conclusion Acute treatment with Pur at the onset of occlusion significantly depresses ischemia-induced efflux of amino acids, especially, excitotoxicity in the striatum, a mechanism underlying the neuroprotective effect on cellular survival.
2007, 20(4)