[Determination of organochlorine pesticides in water using solidification of floating organic drop liquid phase microextraction by gas chromatography].

OBJECTIVE: To develop a new method for simultaneous determination of eight organochlorine pesticides (OCPs) in water samples using solidification floating organic drop liquid-phase microextraction (SFO-LPME) combined with gas chromatography-electronic capture detector (GC-ECD). METHODS: The experimental conditions of SFO-LPME were determined with n-Hexadecane as extractant, water samples adjusted to pH 6.0, inonic strength increased by adding 15.0 g/100 mL NaCI. The OCPs were extracted at 55 degrees C for 10 mm and determined with GC-ECD. RESULTS: A good linearity (correlation coefficients > or = 0.996) was obtained for eight target compounds from 5 ng/I. to 100 ng/L. The method detection limits ranged from 0.24 ng/L to 0.78 ng/L. Satisfactory results were achieved with samples of river water, piped water and farmland water, with an average recovery of 76.0%-106.0% and RSD of 3.24%-11.60%. CONCLUSION: The proposed method is rapid, simple and sensitive. It is suitable for hatch analyses of eight organic chlorine pesticides in water samples.

Perspective on advanced directives among older adults in Shanghai: A qualitative study.

Objective: This study aimed to explore the perception on advanced directives (ADs) among older adults in Shanghai. Methods: Through purposive sampling, 15 older adults with rich life experiences who were willing to share perceptions and experiences of ADs participated in this study. Face-to-face semi-structured interviews were conducted to collect the qualitative data. Thematic content analysis was applied to analyze the data. Results: Five themes have been identified: low awareness but high acceptance of ADs; pursuing natural and peaceful sunset life; ambiguous attitude on medical autonomy; being irrational facing patients' dying and death issues; positive about implementing ADs in China. Conclusion: It is possible and feasible to implement ADs in older adults. Death education and compromised medical autonomy may be needed in the Chinese context as the foundation. The elder's understanding, willingness and worries about ADs should be fully revealed. Diverse approaches should be applied to introduce and interpret ADs to older adults continuously.

[The study on the enamel remineralization by enamel matrix proteins' inducing].

OBJECTIVE: To find the enamel matrix proteins on the impact of enamel mineralization through experiments. METHODS: A combination of protein and beneficial carboxyl groups was grafted on the surface of enamel defects of rats through UV radiation then put into the enamel matrix proteins of calcium phosphate agar acetate solution systems, through scanning enamel surface with the electron microscopy to observe the morphological changes of enamel then analyse the regulation that enamel matrix proteins have done to the white hydroxyapatite crystals on the composition and morphology. RESULTS: In the enamel matrix protein added gel system, we can see the growth of hydroxyapatite crystals, and crystal showed a good degree of crystallinity and contained a small amount of CO3(2-) substituted hydroxyapatite crystals. CONCLUSION: The temperature at 37 degrees C water bath, after adding the enamel matrix proteins to gel system, the new hydroxyapatite crystals were numerous which proved that enamel matrix proteins played an important role in nucleation and growth of hydroxyapatite crystal, so it could be indicated that enamel matrix proteins could induce the enamel remineralization.

[The cleavage activity of GCV transfer vector-mediated hammerhead ribozyme for KRR1 in vitro transcript].

OBJECTIVE: To detect the cleavage activity of Giardia canis virus (GCV) transfer vector-mediated hammerhead ribozyme for KRR1 in vitro transcript. METHODS: Giardia, a most primitive eukaryote, has KRR1 protein responsible for ribosome biosynthesis. cDNA encoding hammerhead ribozyme flanked with various lengths of antisense RNA was cloned into a viral vector pGCV634/GFP/GCV2174 derived from the genome of GCV, KRzS flanked with 21 nt KRR1 antisense RNA on each arm, or KRzL flanked with 288 nt and 507 nt KRR1 antisense RNA. At the same time, two control groups were established: PKR without the inserted ribozyme, and TRzL flanked with 324 nt and 380 nt triosephosphate isomerase (Tim) antisense RNA. The cleavage activity of GCV transfer vector-mediated hammerhead ribozyme for KRR1 in vitro transcript was then analyzed by absolute real-time quantitative RT-PCR. RESULTS: The in vitro cleavage activities on KRR1 mRNA of the two ribozyme KRzS or KRzL were 74.0% and 81.1% respectively by the absolute real-time quantitative RT-PCR. The two control groups, PKR or TRzL, showed no effect on KRR1 mRNA in vitro. CONCLUSION: The GCV transfer vector-mediated hammerhead ribozyme shows a high cleavage activity for KRR1 in vitro transcript, which demonstrates the feasibility of using a viral vector to express a ribozyme targeted at a specific mRNA in Giardia to reduce the expression of a specific gene.

[Giardia canis virus transfection vector-mediated expression of green fluorescent protein in the parasite].

OBJECTIVE: To construct Giardia canis virus (GCV) transfection vector. METHODS: According to transcriptional start site, replication origin and packaging site of GCV genome (DQ238861), a system was developed for the expression of a foreign gene in this organism by flanking the green fluorescent protein (GFP) gene with the fragments of GCV positive-strand RNA. The transcript of the construct was synthesized in vitro with T7 RNA polymerase and used to transfect GCV-infected trophozoites by electroporation. RESULTS: The recombinant plasmid pGCV634/GFP/GCV2174 was constructed. The expression of green fluorescent protein mediated by GCV transfection vector in Giardia canis peaked at 1 d after electroporation (A490=1.8), and slowly decreased until 14 d post-transfection. CONCLUSION: The engineered GCV vector can be successfully used to introduce and efficiently express a heterologous gene in the eukaryotic microorganism.

Pulmonary Function and Retrobulbar Hemodynamics in Subjects With Type 2 Diabetes Mellitus.

BACKGROUND: The primary goals of this study were to evaluate early changes in pulmonary function and retrobulbar hemodynamics and to examine the correlation between these parameters in patients with type 2 diabetes during the preclinical stages of diabetic retinopathy. METHODS: For the single-time point measurements, 63 subjects with type 2 diabetes without diabetic retinopathy (diabetes group) and 32 healthy subjects (control group) were selected to evaluate any early changes in pulmonary function and retrobulbar hemodynamics and to examine the correlation between these parameters. In the longitudinal follow-up study, 32 subjects who were newly diagnosed with type 2 diabetes were divided into 2 groups according to their resistivity index (≤0.7 and >0.7). Early changes in pulmonary function and retrobulbar hemodynamics were studied in these groups and compared with the previous values. RESULTS: For the single-time point measurements, the fasting plasma glucose, 2-h postprandial blood glucose, glycosylated hemoglobin A1c, total cholesterol, low-density lipoprotein cholesterol, and triglyceride levels as well as the pulmonary function parameters were significantly higher in the diabetes group than in the control group. The pulmonary function parameters were negatively and significantly correlated with glycosylated hemoglobin A1c and the duration of diabetes. The retrobulbar hemodynamics were positively correlated with glycosylated hemoglobin A1c and diabetes duration; in contrast, the correlation between retrobulbar hemodynamics and glycosylated hemoglobin A1c. In the longitudinal follow-up study, the pulmonary function of the 2 groups categorized by their resistivity index levels indicated that subjects with resistivity index levels ≤0.7 showed significantly better pulmonary function, and the pulmonary function of this group showed improvement and a significantly smaller decrease. The incidence of diabetic retinopathy in the group with resistivity index levels ≤0.7 (9 of 22, 40.9%) was significantly lower than that in the group with resistivity index levels >0.7. CONCLUSIONS: Pulmonary function and retrobulbar hemodynamics changed during the preclinical stages of diabetic retinopathy. Regulating glycemia may improve retrobulbar hemodynamics in the retrobulbar arteries (ie, central retinal artery, posterior ciliary artery, and arteria ophthalmica). By detecting the retrobulbar resistivity index and the levels of glycosylated hemoglobin A1c, we could predict future changes in pulmonary function during the preclinical stages of diabetic retinopathy as well as the degree of retinopathy. (ClinicalTrials.gov registration NCT02774733.).

Asterosaponins from the starfish Culcita novaeguineae and their bioactivities.

Bioassay-guided fractionation of the n-BuOH extract of the starfish Culcita novaeguineae resulted in the isolation of one new sulfated steroidal glycoside (asterosaponin) (1), along with three known asterosaponins, thornasteroside A (2), marthasteroside A(1) (3) and regularoside A (4), as active compounds causing morphological abnormality of Pyricularia oryzae mycelia. Their structures were elucidated by extensive spectral studies and chemical evidences. All the saponins showed moderate cytotoxicity against cancer cell lines K-562 and BEL-7402.

[Establishment of in vitro cultivation of Giardia canis trophozoites infected with Giardia canis virus].

OBJECTIVE: To cultivate a Giardia canis isolate with G. canis virus (GCV). METHODS: Five-day-old Meriones unguiculatus was infected with the cysts of G. canis isolated from dogs in Changchun and purified by sucrose density gradient centrifugation-G1 acid funnel filtration method. Trophozoites were isolated aseptically from the duodenum of the infected rodent after 8 days, then transferred to modified TYI-S-33 medium and cultivated at 37 degrees C. The trophozoites were centrifuged with 3,000 x g, 15 min after liquid nitrogen freeze-thawing three times and the supernatant stained negatively by phosphotungstic acid was observed with transmission electron microscope. RESULTS: G. canis trophozoites which adapted gradually to the environment and grew a cellular monolayer after 14 days were examined by freezing and thawing experiment, purity quotient, stability, biology characteristics and microbial contamination detection. The results demonstrated that a stable G. canis trophozoite cell isolate was established. G. canis virus with icosahedron spherical shape and 36 nm in diameter was observed by electron microscope. CONCLUSION: In vitro cultivation of G. canis trophozoites with GCV is established.

[Cloning and sequence analysis of a partial gene of Trichomonas vaginalis dsRNA virus].

A pair of degenerate primers were designed following the published nucleotide sequence of Trichomonas vaginalis virus(U08999, NC003873, NC003824, NC003834). Using the total nucleic acids extracted from the Trichomonas vaginalis as template, RT-PCR was performed with the primers to obtain a fragment of the TVV. The product was cloned, sequenced and compared with the sequences available in the GenBank. The size of the amplified gene was 1 454bp, which shares 82.9% sequence identity with the Trichomonas vaginalis virus T1.

[Isolation and structural elucidation of a bioactive saponin from tubers of Bolbostemma paniculatum].

OBJECTIVE: To study the bioactive constituents from tubers of Bolbostemma paniculatum. METHOD: Compounds were isolated by extraction and partition as well as several-chromatographic techniques guided with Pyricularia oryzae bioassay method. Their structures were determined on the basis of spectral analysis and chemical evidence. RESULT: Bisdesmoside (I) was isolated as active compound causing morphological abnormality of Pyncularia oryzae mycelia and elucidated as 3-0-alpha-L-arabinopyranosyl (1-->2)-beta-D-glucopyranosyl-bayogenin-28-O-beta-D-xylopyranosyl (1-->3)-alpha-L-rhamnopyranosyl (1-->2)-alpha-L-arabinopyranoside. CONCLUSION: I is a new natural product and exhibited significant cytotoxicity against cancer cell lines K-562 and BEL-7402, but no hemolytic activity to rabbit erythrocytes.

The effect of alogliptin on pulmonary function in obese patients with type 2 diabetes inadequately controlled by metformin monotherapy.

BACKGROUND: To observe the effect of alogliptin combined with metformin on pulmonary function in obese patients with type 2 diabetes inadequately controlled by metformin monotherapy (500 mg, bid po, for at least 3 months), and evaluate its efficacy and safety. METHODS: After a 2-week screening period, adult patients (aged 36-72 years) entered a 4-week run-in/stabilization period. Then, patients were randomly assigned to either the intervention group (n = 55) or the control group (n = 50) for 26 weeks. The patients in the control group were given metformin (1000 mg, bid po) and the patients in the intervention group were given metformin (500 mg, bid po) combined with alogliptin (25 mg, qd po). All the patients received counseling about diet and exercise from a nutritionist during run-in and treatment periods.The primary endpoints were the between-group differences in the changes in pulmonary function parameters (vital capacity [VC]%, forced vital capacity [FVC]%, forced expiratory volume in 1 second (FEV1)%, peak expiratory force [PEF]%, maximal voluntary ventilation [MVV]%, total lung capacity [TLC%], forced expiratory volume in 1 second/forced vital capacity [FEV1/FVC%], diffusing capacity for carbon monoxide of lung [DLCO]%, and diffusing capacity for carbon monoxide of lung/unit volume [DLCO/VA%]) between pretherapy and posttreatment. The secondary endpoints were changes from baseline to week 26 in glycosylated hemoglobinA1c (HbA1c), FPG, 2hPG, homeostasis model assessment insulin resistance (HOMA-IR), waist circumference (WC), and BMI. The tertiary endpoints were the changes from baseline to week 26 in blood-fat (total cholesterol [TC], high-density lipoprotein cholesterol [HDL-C], low-density lipoprotein cholesterol [LDL-C], and triglycerides [TG]). The quartus endpoints were the changes from baseline to week 26 in systolic blood pressure (SBP) and diastolic blood pressure (DBP). The 5th endpoints were the changes from baseline to week 26 in oxidative/antioxidative parameters (reactive oxygen species [ROS], malondialdehyde [MDA], superioxide dismutase [SOD], and glutathione peroxidase [GSH-Px]). In addition, safety endpoints were assessed (AEs, clinical laboratory tests, vital signs, and electrocardiographic readings). RESULTS: Eighty-one patients completed our clinical trial: intervention group (n = 44) and control group (n = 37). At week 26, pulmonary function parameters (VC%, FVC%, FEV1%, PEF%, MVV%, TLC%, FEV1/FVC%, DLCO%, and DLCO/VA%) had increased significantly from pretherapy values in both groups (P < 0.05), and the pulmonary function tests were significantly greater (P < 0.05) in intervention group than in controls posttherapy. Pulmonary function (FVC%, FEV1%, PEF%, TLC%, FEV1/FVC%, DLCO%, and DLCO/VA%) was lower in the group with HbA1c levels ≥8.0 at 26 weeks, but VC%, FEV1%, MVV%, and TLC% were not significantly lower (P > 0.05). Pulmonary function parameters were positively correlated with GSH-Px and SOD and negatively correlated with ROS and MDA. Mean declines in HbA1c, FPG, 2hPG, HOMA-IR, and blood-fat (TC, HDL-C, LDL-C, and TG) were significantly greater (P < 0.05) in intervention group compared with the controls, but mean declines in BMI, WC, and BP (SBP, DBP) did not differ significantly between the 2 groups (P > 0.05). SOD and GSH-Px increased more (P < 0.05) in the intervention group, compared with the controls; ROS and MDA declined more (P < 0.05) in intervention group, as compared with the control group. The most common AEs were gastrointestinal events, headaches, skin-related AEs (mostly pruritic events), and hypoglycemia. The incidences of AEs did not differ significantly (P > 0.05) between the 2 groups except for the headache and skin-related adverse events (the incidence of headache was higher in the intervention group than in controls; P < 0.05). No patient died during the study. CONCLUSION: In patients with type 2 diabetes mellitus (T2DM) inadequately controlled by metformin monotherapy, the addition of alogliptin contributed to clinically significant increases in pulmonary function through regulating glycemia and improving the imbalance of the oxidative-related substances in the serum, without increasing the incidence of hypoglycemia, dyslipidemia, dysarteriotony, and any notable increase in body weight.

[Correlation between sensitivity to TRAIL and expression level of DR5 on surface of tumor cells].

OBJECTIVE: To investigate the correlation between sensitivity to tumor necrosis factor-related apoptosis inducing ligand (TRAIL) and expression level of death receptor 5 (DR5) on tumor cell surface. METHODS: Anti-DR5 mAb was used to detect expression level of DR5 on surface of tumor cells by flow cytometry. Sensitivity to apoptosis induced by TRAIL was determined by TRAIL apoptosis kit. The correlation between expression level of DR5 and sensitivity to TRAIL was analyzed. RESULTS: The expression of DR5 on surface of tumor cells was approximately 97.9% in U937 cells, 95.1% in Jurkat cells, 93.8% in SW480 cells, 86.2% in HCT116 cells, 64.2% in HL-60 cells, 46.6% in HeLa cells and 13.1% in K562 cells, respectively. The apoptosis rate induced by TRAIL was 72.6% in U937 cells, 85.2% in Jurkat cells, 78.6% in SW480 cells, 70.2% in HCT116 cells, 60.1% in HL-60 cells, 45.4% in HeLa cells and 12.3% in K562 cells, respectively. There was a significant positive correlation between the expression level of DR5 with TRAIL-inducing apoptosis (r = 0.997, P < 0.001). CONCLUSION: TRAIL-inducing apoptosis is related to the expression level of DR5 on surface of tumor cells. The results confirm the importance of DR5 expression for induction of apoptosis by TRAIL.

[Study on the relationship between the functional integrity of sperm membrane and seminal parameters related to CASA].

OBJECTIVES: To evaluate the relationship between the functional integrity of sperm membrane and seminal parameters related to CASA. METHODS: Thirty-eight fertile and one hundrend and twenty four infertile males were tested the functional integrity of sperm membrane by the kit and parameters by CASA. RESULTS: There was a significant difference in the functional integrity of sperm membrane between fertile and infertile group (P < 0.01). The items related to CASA between normal and abnormal group in the functional integrity of sperm membrane had a remarkable difference, except motion degree, seminal volume and pH. CONCLUSIONS: To determine the functional integrity of sperm membrane can be used as a necessary supplementary method for CASA, and it has clinical significance in diagnosing, treating and researching male infertility.

A novel agonistic anti-human death receptor 5 monoclonal antibody with tumoricidal activity induces caspase- and mitochondrial-dependent apoptosis in human leukemia Jurkat cells.

An agonistic antibody against TNF-related apoptosis-inducing ligand death receptor 5 (DR5) is a practicable candidate drug for antitumor therapy. In this study, a novel murine anti-human DR5 monoclonal antibody, mDRA-6(IgG1-κ), has been generated. This study aimed to explore the caspase-dependent and mitochondrial mechanisms of mDRA-6 in inducing apoptosis in human leukemia Jurkat cells. The apoptotic effects of mDRA-6 on Jurkat cells, which express DR5 on the cell surface, were detected by flow cytometry and western blot after exposure to different doses of mDRA-6 and at fixed doses of mDRA-6 at different times. It was demonstrated that mDRA-6 can induce Jurkat cell apoptosis via caspase- and mitochondrial-dependent pathways. These results indicate that the novel antibody mDRA-6 against DR5 has an antitumor function and may provide a new reagent for tumor therapy.

[Role of enamel matrix proteins in inducing biomimetic mineralization of the enamel: a study with quartz crystal microbalance technique].

OBJECTIVE: To investigate the adsorption behavior of enamel matrix proteins (EMPs) on the enamel surface and study their effect on biomineralization of enamel using quartz crystal microbalance (QCM) technique. METHODS AND RESULTS: The EMPs were adsorbed on the enamel surface to form a protein film, which was soaked in simulated body fluid solutions. After 30 days of biomimetic mineralization, the hydroxyapatite nucleation, growth and aggregation occurred with hydroxyapatite crystal formation on the enamel surface. CONCLUSION: The EMPs play a key role in regulating enamel mineralization.

Caspase-dependent molecular mechanisms of anti-human DR5 monoclonal antibody mDRA-6 inducing apoptosis of human leukemia Jurkat cells.

BACKGROUND AND OBJECTIVE: Both tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) and some monoclonal agonistic antibodies against TRAIL receptors have antitumor activity. We have previously prepared a novel monoclonal agonistic antibody against human death receptor 5 (DR5) and designated it as mDRA-6. This study was to explore the Caspase-dependent molecular mechanisms of mDRA-6 inducing apoptosis of human leukemia Jurkat cells. METHODS: After exposure to different doses of mDRA-6, DNA fragmentation of Jurkat cells was detected by agarose gel electrophoresis, cell proliferation was detected by MTT assay, and cell apoptosis was detected by flow cytometry after Annexin V-FITC/PI double staining. Jurkat cells were further treated with the inhibitors for Caspase-10, -9, -8 and -3. The active cleavage products of Caspase-10, -9, -8, -3 and poly ADP-ribose polymerase (PARP), BH3 interacting domain death agonist (Bid), truncated Bid (tBid) and cytochrome c (Cyto c), were analyzed by western blot. RESULTS: After mDRA-6 treatment, DNA fragmentation was detected in Jurkat cells. mDRA-6 inhibited cell proliferation in a dose-dependent manner. When treated with 2.0 microg/mL mDRA-6, the apoptosis rates of Jurkat cells were 16.2% at 0.25 h, 28.3% at 0.5 h, 69.2% at 1 h and 78.2% at 2 h. Interestingly, the mDRA-6-induced apoptosis was repressed by 77.9% by Caspase-8 inhibitor ZIF, 54.2% by Caspase-3 inhibitor ZDF, and 8.7% by Caspase-9 inhibitor ZLF, but was not repressed by Caspase-10 inhibitor ZAF. After mDRA-6 exposure, the proenzymes of Caspase-8, -9 and -3 were reduced and their active cleavage products were increased along with the increase of exposure time, the cleavage products of PARP were also increased, Bid was degraded to tBid, and an abundance of Cyto c was released from mitochondria, but the proenzyme of Caspase-10 showed no change and no cleavage products of Caspase-10 were detectable. CONCLUSION: mDRA-6 can induce apoptosis of Jurkat cells via the Caspase-dependent and mitochondrial pathways.

[Grafting functional groups on enamel surface by a self-assembled monolayer technique].

OBJECTIVE: To study the influence of various active groups grafted on the enamel surface by means of self assembly on enamel biomineralization. METHODS: The enamel was prepared by immersing the bicuspid tooth into 1 mmol/L ethanolic solution of a omega-functionalized (omega=PO4H2, SO3H, COOH or OH) group and deionized water solution of HSCH2CH2SO3Na for 24 h at room temperature. The contact angles and infrared (IR) images were used to identify the morphological changes of the enamel with chemisorption of the functional groups. RESULTS: The contact angles and IR images showed that the omega-functionalized (omega=-PO4H2, -SO3H, -COOH, -OH or -CH3) group was chemisorbed on the enamel surface. CONCLUSION: Self assembled monolayers with omega-functionalized (omega=-PO4H2, -SO3H, -COOH, -OH or -CH3) group can be successfully formed on the enamel surface by hydrolyzation.

[Synergistic lethal effect of mDRA-6 and nimesulide on human hepatocellular cancer cell line SMMC-7721].

BACKGROUND & OBJECTIVE: Both mDRA-6, a monoclonal antibody of death receptor 5 (DR5) in human cells prepared by our key laboratory, and nimesulide, a specific cyclooxygenase-2 (COX-2) inhibitor, can induce apoptosis of some malignant tumor cells. This study was to investigate the lethal effects of mDRA-6 and nimesulide on human hepatocellular cancer cell line SMMC-7721, and explore the possible mechanism. METHODS: The expression of DR5 on SMMC-7721 cells was detected by flow cytometry (FCM). SMMC-7721 cells were treated with mDRA-6 and nimesulide alone or in combination. Cell morphology was observed under microscope with Hoechst33258 staining. Cytotoxicity was examined by MTT assay. Cell apoptosis was detected by FCM. RESULTS: The positive rate of DR5 on SMMC-7721 cells was 95.0%. The apoptosis of SMMC-7721 cells could be induced by both mDRA-6 and nimesulide: the apoptosis rates were 10.5% when treated with 25 ng/mL mDRA-6 for 12 h, 35.0% when treated with 1 600 ng/mL mDRA-6, 5.0% when treated with 200 micromol/L nimesulide, and 34.0% when treated with 800 micromol/L nimesulide. The combination of mDRA-6 and nimesulide exhibited synergistic effect on the apoptosis of SMMC-7721 cells (q=1.23): the apoptosis rates were 31.2% when treated with 200 micromol/L nimesulide and 25 ng/mL mDRA-6 for 12 h, and 91.1% when treated with 200 micromol/L nimesulide and 1 600 ng/mL mDRA-6 for 12 h. CONCLUSIONS: Both mDRA-6 and nimesulide can induce the apoptosis of SMMC-7721 cells. The combination of mDRA-6 and nimesulide exhibits synergistic lethal effect on SMMC-7721 cells.

[Study on an outbreak of echovirus type 6 of meningitis in Liu'an city, Anhui province].

OBJECTIVE: To understand the epidemiological, clinical and etiological characteristics of an Echovirus type 6 meningitis outbreak in Jinzhai county, Liu'an city in Anhui, and to find out the proper way in controlling the aseptic meningitis outbreak. METHODS: A surveillance system for aseptic meningitis was established in Jinzhai to confirm the case definition. Stool or cerebrospinal fluid (CSF) specimens from some cases were collected for entero-viruses isolation and identification. Case-control study was conducted. The case group involved patients while the controls would include: patients' classmate with same gender and the age difference was not over one year. Neutralization antibody in serum specimens were collected and tested in cases and in healthy people. RESULTS: 105 cases were distributed in 17 of the 30 towns in Jinzhai county while 41.0% of the cases were in Banzhuyuan town with an incidence rate of 203/10(5). Cases were clustered by school and classroom with age ranging from 3 to 15 years old and the highest as 10.9/10(5) in the 6 to 10 group. The incidence in males was 24.2/10(5) compared to 8.4/10(5) in females. The main clinic characteristics of cases were: fever, headache and vomiting. Echovirus type 6 from 25 of the 72 CSF samples (35%) was isolated. When comparing the cases group with control group, the OR of drinking home-made beverages was 4.1 (95% CI: 1.4-12.0), especially the beverages sacked by plastic bag: 3.3 (95% CI: 1.3-8.8). 6 out of 7 workers engaging in producing home-made beverages were detected to have carried Echovirus type 6 from their stool specimens. The Echovirus type 6 neutralization antibody positive rate in cases (73.5%) was significantly higher than that in 100 healthy people (46.0%) (X2 = 12. 526, P = 0.000). CONCLUSION: This episode of meningitis outbreak was caused by Echovirus type 6. The proportion of drinking home-made beverages, especially the beverages sacked by plastic bag in cases group was higher than in control group.

[Preparation and characterization of monoclonal antibody against DR5].

AIM: To prepare monoclonal antibodies(mAb) against DR5 and characterize their properties. METHODS: BALB/c mice were immunized with DR5, and then mAb was prepared by hybridoma technique. Ig subclass and specificity of mAbs was analyzed by ELISA and flow cytometry, respectively. The titres of mAbs in ascitic fluid, relative affinity and epitopes recognized by mAbs were determined by indirect ELISA. RESULTS: Four hybridoma cell lines secreting anti DR5 mAbs were obtained. Their Ig subclass belonged to IgG1. The titers of 4 mAbs in ascitic fluid were 1x10(-4) - 5x10(-6). Affinity constant of mAbs were 1x10(9). They recognized 2 different epitopes on DR5 molecule. CONCLUSION: Four mAbs against DR5 are prepared successfully, which provides useful reagent for clinical diagnosis and further research.