2002 Vol. 15, No. 1
To sequence the gene encoding glutamate rich protein (GLURP) and identify the genotypes of geographically different Plasmodium falciparum (P. f ) isolates from China. Methods The gene of R2 repeat region of GLURP was amplified by nested polymerase chain reaction and cloned into T-vector. The nucleotide sequence of GLURP gene was determined by automatic sequencer (Dideoxy termination method) and analyzed by DNA Star software. Results At least 7different GLURPgenotypesranging from 600 bp to 1 500 bp were found in Yunnan and Hainan provinces. R2 region of GLURP gene consisted of several repeat units. Each repeat unit was composed of 19-20 residues which were shown to be highly conserved. GLURP gene was also size polymorphic due to differences in the number of repeat units, whereas the repeat sequence was conserved. Sequence analysis showed that DNA sequences and deduced amino acid sequences were highly homologous among the geographically dispersed isolates or various isolates from the same geographical region. No obvious differences were found in the GLURP gene sequences among geographically different isolates. Conclusion GLURP gene is highly structure conserved and size polymorphic, and so is useful in searching for malaria vaccine candidate antigen and developing a genotyping method for malaria research.
The study investigated the burden of smear-positive pulmonary TB and its infectivity using DALY(disability-adjusted life year) as an indicator. Methods An assumed cohort of 2 000 cases was set up based on the age-specific incidence of 794 newly registered smear-positive cases in Beijing in 1994. Prognostic trees and model diagrams of infectivity under natural history and DOTS(directly observed treatment, short-course) strategy were established according to the epidemiological evidence. Results The results showed that 29.6%of DALYs would be neglected if the burden caused by the infectivity was not considered.Conclusion DOTS strategy may reduce 97.3% of the number of potential cases infected,92.9% of DALYs related to TB-patients themselves. and 99.9% of DALYs caused by TB's infectivity as well.
To determine the possible relationship between plasma potassium concentration and severity of acute trimethyltin chloride (TMT) poisoning and to assess the mechanism of TMT induced hypokalemia. Methods SD rats were treated with various dosages of TMT (ip). All the indices were measured and analysed for determing their possible relations with plasma K+. Results With increase of dosage, the plasma K+ level dropped rapidly, and deaths appeared more quickly. The LDs0 of TMT (ip) was 14.7 mg/kgbw. In the low dosage group (10 mg/kgbw), the plasma K+ level dropped slowly with the lowest dosage on day 6 (4.85 mmol/L). It rose again on day 11 (5.06 mmol/L), and recoverd on day 28. The poisoning signs corresponded with decline of the span of K+ level. The plasma Na+ level dropped half an hour after TMT treatment, but recovered 24 h later. In the high dosage group (46.4 mg/kgbw), the levels of plasma K+ and Na+ fell rapidly within half an hour (P＜0.05), the intracellular potassium concentration of RBC did not decrerase obviously (P＞0.05), the activities of Na+-K+-ATPase and Mg2+-ATPase in RBC membrane were depressed remarkably (P＜0.01, P＜0.05, respectively), the plasma aldosterone concentrations rose as high as tenfold (P＜0.01), the arterial blood pH fell from 7.434 to 7.258 (P＜0.01),pCO2 was raised from 29.62 to 45.33 mmHg (P＜0.01). In the 24 h urine test, when rats were treated with TMT (21.5 mg/kgbw, ip), urine volume, urinary potassium, sodium and chloride increased significantly in comparison with those in the controls (P＜0.01). Conclusion TMT could induce hypokalemia in SD rats. The available evidence suggests that TMT can induce acute renal leakage of potassium. At the same time, a significant rise of plasma aldosterone may play an important role in promoting potassium leakage from kidney to result in severe hypokalemia with inhaling acid-base abnormalities produced, which aggravate the poisoning symptoms. In the end the rats would die of respiratory failure.
To evaluate CC2 (N, N' -dichloro-bis [2, 4, 6-trichlorophenyl] urea) in various hydrophilic and lipophilic formulations as a personnel decontaminant for sulphur mustard (SM). Methods Twenty percent of CC2 was prepared as a suspension or ointment with various chemical agents and its stability was evaluated by active chlorine assay. The efficacy was evaluated in mice by recording the mortality after applying 29 LD50 of SM (LD50 =8.1 mg/kg dermally) and decontaminating it after 2 min with 200 mg of the formulation.Studies were also carried out with 10% and 20% CC2 in acacia and hydroxypropyl cellulose,and the suspensions were stored in polyethylene containers. The stability of the suspensions was evaluated by active chlorine assay. The efficacy was evaluated by recording the mortality after applying 29 LD50 of SM in mice and 12 LD50 of SM in rats (LD50 = 2.4 mg/kg dermally), and decontaminating it with the formulations. LD50 by different routes and primary skin irritation test of CC2 were also carried out. Results CC2 reacted with peanut oil and neem oil, and was unstable in povidone iodine and Fuller's earth. Good stability was achieved with petroleum jelly, honey, polyvinyl pyrrolidone, calamine lotion, acacia and hydroxypropyl cellulose. Though CC2 was stable in lipophilic formulations, it did not protect the animals. The hydrophilic formulations particularly acacia and hydroxypropyl cellulose gave very good protection and was stable in the polyethylene containers for a period of 1 year. The efficacy of 20% CC2 was better than 10% CC2. The oral and dermal LD50 of CC2 was found to be above 5.0 g/kg. CC2 was also found to be nonirritant.Conclusion Twenty percent of CC2 in hydroxypropyl cellulose is better with respect to stability, efficacy and ease of decontamination. CC2 is also a safe chemical.
To detect the trans-factors specifically binding to the strong enhancer element (GPEI) in the upstream of rat glutathione S-transferase P (GST-P) gene. Methods Yeast one-hybrid system was used to screen rat lung MATCHMAKER cDNA library to identify potential trans-factors that can interact with core sequence of GPEI(cGPEI).Electrophoresis mobility shift assay (EMSA) was used to analyze the binding of transfactors to cGPEI. Results cDNA fragments coding for the C-terminal part of the transcription factor c-Jun and rat adenine nucleotide translocator (ANT) were isolated, The binding of c-Jun and ANT to GPEI core sequence were confirmed. Conclusions Rat c-jun transcriptional factor and ANT may interact with cGPEI. They could play an important role in the induced expression of GST-P gene.
To study the effects of diallyl sulfide (DAS), an organosulfur compound present in garlic (Allium sativum),on the life span ofehrlich ascites (EA) tumor bearing Swiss albino mice, cytotoxicity and angiogenesis. Methods EA tumor cells were maintained by serial transplantation in peritoneal cavity of male Swiss albino mice. EA tumor cells were inoculated at concentrations of 1 × 106EA cells, 2.5 × l06EAcells and 5 × 106 EA cells. DAS was given in 0.2 mi normal saline i. p., daily for seven days followed one hour later by inoculation with EA cells in respective groups. Results The results revealed that administration of DAS increased the life span of EA tumor bearing animals by more than 25 percent. A significant dose dependant cytotoxic response of DAS was also observed on EA tumor cells. DAS was also found to inhibit the angiogenesis in EA tumor bearing mice in a dose dependent manner. Conclusion It is suggested that DAS may exert its anticarcinogenic effects by more than one mechanism and is a useful chemopreventive and chemotherapeutic agent.
To study the state of oxidative stress in patients with acute coxsackie virus myocarditis (ACM), and to investigate the pathological chain reactions of a series of free radicals and oxidative and lipoperoxidative damages in their bodies. Methods Eighty ACM patients and 80 healthy adult volunteers (HAV) were enrolled in a case-control study, in which concentrations of nitric oxide (NO) in plasma, lipoperoxides (LPO) in plasma and LPO in erythrocytes (RBC), vitamin C (VC), vitamin E (VE) and β-carotene (β-CAR) in plasma as well as activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) in RBC were determined by using spectrophotometric assays. Results Compared with the average values (AV) of the above biochemical parameters (BP) in the HAV group, the AV of NO in plasma, and LPO in plasma and RBC in the ACM group were significantly increased (P=0.0001), while the AV of VC, VE, β-CAR, SOD, CAT and GSH-Px in the ACM group were significantly decreased (P=0.0001). The values of the above BP were used to estimate the relative risk ratio (RR) between the ACM group and the HAY group; the RR and its 95 % confidence interval were 12.467 (5.745～27.051), 4.333(2.126～8.834), 6.517 (3.225～13.618), 3.310 (1.598～6.858), 31.000 (12.611～76.201),4.663 (2.228～9.759), 11.769 (5.440～25.462), 3.043 (1.486～6.229) and 6.594 (3.045～14.281)respectively, and their P levels ranged from 0.002 to 0.0001. The results were asfollows: D = 22.143 - 0.017SOD + 0.008NO + 0.244LPO in RBC, Eigenvalue = 13.659,Canonical correlation = 0.965, Wilks' λ = 0.068, χ2 = 420.212, P = 0.0001. The correct rate of discrimination to the ACM group and to the HAV group was 87.5% and 95.0 %, respectively,and 91.3 % of originally grouped cases was correctly classified. Conclusion The findings in this study suggested that the oxidative stress in bodies of ACM patients was severely aggravated, and marked high oxidative constituents and low antioxidants and antioxidases in the human body might increase the relative risk of inducing acute coxsackie virus myocarditis, and measuring the values of NO in plasma, SOD and LPO in RBC might increase the correct rates of discriminatory analysis of the ACM.
To improve the chemically-activated luciferase expression (CALUX)bioassay for detection of dioxin-like chemicals (DLCs) based on the toxicity mechanisms of DLCs. Method A recombinant vector was constructed and used to transfect human hepatoma (HepG2). The expression of this vector was 10-100 folds higher than that of pGL2used in previous experiments. The transfected cells showed aromatic hydrocarbon receptor (AhR)-meditated luciferase gene expression. The reliability of luciferase induction in this cell line as a reporter of AhR-mediated toxicity was evaluated, the optimal detection time was examined and a comparison was made by using the commonly used ethoxyresoufin-Odeethylase (EROD) activity induction assay. Result The results suggested that the luciferase activity in recombinant cells was peaked at about 4 h and then decreased to a stable activity by 14 h after TCDD treatment. The detection limit of this cell line was 0.1 lpmol/L, or 10-fold lower than in previous studies, with a linear range from 1 to 100pmol/L, related coefficient of 0.997, and the coefficient of variability (CV) of 15-30%,Conclusion The luciferase induction is 30-fold more sensitive than EROD induction, the detection time is 68 h shorter and the detection procedure is also simpler.
To investigate whether cadmium-induced oxidative stress in the kidney is influenced by zinc and selenium. Methods Five groups of rats were maintained: (A) Cd (CdCl2,400 μg@kg-1 day-1 intraperitoneal injection); (B) Cd+Zn (ZnC12, 20mg kg-1.day-1 hypodermic injection); (C) Cd+Se (Na2SeO3, 350 μg.kg-1.day-1 via a stomach tube); (D) Cd+Zn+Se; (E)treated with physiological saline as a sham-handled control. The rats were given treatmenl for a period of 4 weeks. The activities of superoxide dismutase (SOD), glutathione peroxidase (GH-Px), catalase (CAT), and the level of malondialdehyde (MDA) in the kidney tissue were measured to assess the oxidative stress. Urinary lactate dehydrogenase (LDH) activity was used as an indicator of tubular cell damage caused by lipid peroxidation. Results In group C and D, activities of SOD (110.5 ± 5.2, 126.8 ± 7.0; P ＜ 0.05) and GSH-Px (85.7 ± 4.9,94.6 ± 7.3; P ＜ 0.05) were higher than those in group A(84.7 ± 3.3; 56.9 ± 3.8); and in group B, only the activity of GSH-Px (80.0 + 4.3, P ＜ 0.01) increased in comparison with that in group A (56.9 ± 3.8). Significant increase of MDA (P ＜ 0.05) was seen in group B (31.1 ± 4.7) and C (35.0 + 4.1) when compared with control values (17.2 ± 1.8). No difference was found in the level of MDA between group D (18.9 ± 2.6) and control. The activity of LDH in urine of control group (0.06 ± 0.02) was lower than that of group A (0.46 ± 0.19, P＜0.05), B (0.10± 0.05, P＜0.05) and C (0.14 ± 0.07, P＜0.05), and there was no significant change between control (0.06 + 0.02) and group D (0.08 ± 0.02). Conclusion Zinc or selenium could partially alleviate the oxidative stress induced by cadmium in kidney, but administration cadmium in combination with zinc and selenium efficiently protects kidney from cadmiuminduced oxidative damage.
To investigate the distribution of single nucleotide polymorphisms (SNPs) in CAPN10 gene in Chinese population and their relation with type 2 diabetes mellitus in Han people of Northern China. Methods CAPN10 gene was sequenced to detect SNPs in different nationalities of China. Five SNPs were chosen to perform case-control study and haplotype analysis in 156 normal Han people of Northern China and 173 type 2 diabetes. One SNP was also analyzed with transmission-disequilibrium test (TDT) and sib transmissiondisequilibrium test (STDT) in 68 type 2 diabetes pedigrees (37Tpeople). Results A total of 40 SNPs were identified in length of 8 936bp, with an average of 1 in every 223bp. The SNPs in CAPN10 gene did not distribute evenly and the SNPs in Chinese were different from those reported in Mexican American. There was no significantly statistical difference in the allele frequency of the 5 SNPs between case and control, and the haplotype frequencies in the two groups were not significantly different. No positive results was found in TDT and STDT analysis. Conclusions The SNP distribution of CAPN10 gene differs in different nationalities. The studied SNPs in CAPN10 gene may not be the major susceptibility ones of type 2 diabetes mellitus in Han people of Northern China.
For prevention of obesity in Chinese population, it is necessary to define the optimal range of healthy weight and the appropriate cut-off points of BMI and waist circumference for Chinese adults. The Working Group on Obesity in China under the support of International Life Sciences Institute Focal point in China organized a meta-analysis on the relation between BMI, waist circumference and risk factors of related chronic diseases (e. g.,high diabetes, diabetes mellitus, and lipoprotein disorders). Methods 13 population studies in all met the criteria for enrollment, with data of 239 972 adults (20-70 year) surveyed in the 1990s. Data on waist circumference was available for 111411 persons and data on serum lipids and glucose were available for more than 80 000. The study populations located in 21provinces, municipalities and autonomous regions in mainland China as well as in Taiwan. Each enrolled study provided data according to a common protocol and uniform format. The Center for data management in Department of Epidemiology, Fu Wai Hospital was responsible for statistical analysis. Results and conclusion The prevalence of hypertension, diabetes, dyslipidemia and clustering of risk factors all increased with increasing levels of BMI or waist circumference. BMI at 24 with best sensitivity and specificity for identification of the risk factors, was recommended as the cut-off point for overweight, BMI at 28 which may identify the risk factors with specificity around 90 % was recommended as the cut-off point for obesity. Waist circumference beyond 85 cm for men and beyond 80 cm for women were recommended as the cut-off points for central obesity.Analysis of population attributable risk percent illustrated that reducing BMI to normal range (＜24) could prevent 45%-50% clustering of risk factors. Treatment of obese persons (BMI ≥ 28)with drugs could prevent 15%-17% clustering of risk factors. The waist circumference controlled under 85 cm for men and under 80 cm for women, could prevent 47%-58% clustering of risk factors. According to these, a classification of overweight and obesity for Chinese adults is recommended.
Quick Links