As a most common algal toxin in eutrophic freshwater body, microcystins can be produced by the bloom-forming Cyanophyta microcystis, it has become a potential hazardous substance in aquatic environments for its toxic, distribution and stability. With the increasing recognition of microcystins, China had added microcystin-LR into the related water quality standards. It is very important to detect and control the microcystins in the aquatic environment. This paper systematically introduced the current situation of researches about the determination and pollution control technique of microcystins in drinking water at home and abroad in resent years and then some issues worth of paying more attention to and doing further study in pollution control in future were presented.

Objective To understand the synergistic effect of zinc and vitamin C on the anti-oxidative ability of sport training mouse. Methods 30 mice were randomly divided into 5 groups, blank control, normal saline solution, zinc , vitamin C and zinc + vitamin C. After 3 weeks of treatment, the activity of superoxide dismutase (SOD) and the content of malondialdehyde (MDA) in the serum, liver and brain were determined. Results Compared with the control, the activity of SOD in the serum, liver and brain of the mice treated with zinc and vitamin C significantly increased, the content of MDA showed a significant decrease, the combination of zinc and vitamin C presented the best effect. Conclusion Combination of zinc and vitamin C has a significant synergistic effect in improvement of anti-oxidative ability.

Objective To explore the total anti-oxidation capacity(T-AOC), superoxide dismutase(SOD), nitric oxide synthase(NOS) and nitric oxide(NO) in testis homogenate of the rats’ with chronic fluorosis induced by drinking NaF solutions with different concentration. Methods 24 male Wistar rats were divided into 3 groups (8 rats per group) including control group, low-fluoride(LF) group, high-fluoride(HF) group, which were exposed to fluoride by means of freely drinking tap water containing NaF with 0, 100 and 200 mg/L respectively for 20 weeks. T-AOC, NOS activities and SOD activity of the testis tissue were determined by colorimetry , xanthine oxidase method and nitrate reductase method respectively. Results Compared with the control group, the T-AOC of the testis tissue increased significantly in LF group and decreased significantly in HF group. SOD activity of the testis tissue showed on significant difference among the control group, LF group and HF group . Compared with the control group, the levels of NOS and NO decreased significantly in LF group and increased significantly in HF group. Conclusion The T-AOC of the testis tissue exposed to low level of fluoride presents a compensatory increase induced by the inhibited activity of NOS and synthesis of NO. Higher level of fluoride may increase reactive oxygen species(ROS), and cause abnormal expression of induce nitric oxide synthase(iNOS) and increased synthesis of NO in the testis tissue.

Objective To explore the effects of iodine on apoptosis and proliferation of the thyroid cells. Methods Wistar rats of one month wean were randomly divided into five groups(low iodine-LI, normal iodine-NI, fivefold high iodine-5 HI, tenfold high iodine-10 HI, fiftyfold high iodine-50 HI), and fed on water containing different concentration of iodine. All groups got prospective iodine intake, that is 0.6, 6.15, 30.75, 61.5, and 307.5 mg/d. After 7 days, 14 days, 28 days, the rats were sacrificed. The proliferation, apoptosis, and apoptosis related genes expression in the thyroid cells were determined by TUNEL, immunohistochemistry and RT-PCR. Results As for short-term of iodine deficiency, no significant change was seen in the mRNA expression of fas and fasL genes, while in the iodine excess groups,the expreesion showed an up-regulation trend as iodine intake increased. Fas and FasL proteins expressions were consistent in LI and NI groups and all of them were negative or weak positive. In the HI groups the stain density increased with iodine intake and treatmnet period increased. Expression of PCNA was enhanced by short-term iodine deficiency, but not by short-term iodine excess. Apoptosis was not observed in all groups. Conclusion Both short-term iodine deficiency and iodine excess have no obvious effects on thyrocytes apoptosis. Proliferation can be induced by short-term iodine deficiency, not by iodine excess. Wistar rats present a strong tolerance to long-term iodine excess.

Objective To study the epidemic factors of hemorrhagic fever with renal syndrome (HFRS) in an area in Tianjin in 1997—2005. Methods The descriptive statistical analysis was used to describe the status of HFRS. The Hantavirus(HV) carrier in the mice was investigated and the data of the meteorological, agricultural and population were collected. Rank sum tests were employed to analyze the epidemic of the disease. Results The epidemic of HFRS in the investigated area started from 1997 with annually increasing, the peak was seen in 2002, then it was dropping down. There were 105 cases in total with 4 cases died. The cases were found all over the district, including 11 towns and 70 villages. The cumulative incidence rate was 2.90/100 000, the mortality rate was 0.11/100 000, and the case fatality rate was 3.81%. The seasonal difference was found in this study. The incidences in April and May were highest, accounted for 44.76% of the total cases. The cases in the 30-year-old group accounted for one third of the total occurrence, the ratio of male to female was 3.57∶1. The incidence was highest in the farmers, accounted for 26.67%, in the transient population it accounted for 54.29%. There was a consistency between the index of HV carrier and the epidemic trend. A positive correction was seen between the average temperature and the disease incidence rate (rs=0.746, P=0.021), a negative correction was seen between the precipitation and the incidence rate (rs=-0.695, P=0.038) and between the crop area and the incidence rate (rs=-0.167, P=0.532). Conclusion The investigated area is the epidemic area where HFRS is caused by Seoulvirus(SEOV), the primitive host is Rattusnorvegicus. The main epidemic factors include the transient population massively moved into the area since the mid 1990s, the change of the predominant mice in this area, destruction of the habitats of the mice, the rats migration, the increase of the index of HV and the transformation project of houses and the farmland destruction.

Objective To know the effect of cold stress on the artery pressure and the concentration of IL-2, IL-10, IFN-?, TNF-? in the serum of the rabbits. Methods The local white rabbits of China (clean grade) were anesthetized. The mAP (mean artery pressure), mSP (mean systolic pressure), mDP (mean diastolic pressure) and the concentration of IL-2, IL-10, IFN-?, TNF-? were determined at 0 h, 0.25 h, 0.50 h, 0.75 h, 1.00 h, 1.50 h, 2.00 h, 3.00 h, 4.00 h and 6.00 h after cold stress. Results The mAP,mSP and mDP changed undulant with the delay of cold stress,but the whole tendency was descendent. The mAP,mSP and mDP went up to the peak at 1 h,however lower than control. The concentration of IL-2 increased then decreased with the delay of cold stress,the concentration of IL-10 went down then up and the concentration of TNF-?,IFN-? went down gradually. There was a strong correlation between IFN-? and TNF-? (r=0.983 0,P

Objective To explore the protective effects of lycium barbarum polysaccharides(LBP) on fibroblast in vitro irradiated by ultraviolet A(UVA). Methods Taking the primary cultured fibroblast as objects, the fibroblast was irradiated by UVA ( irradiation intensity: 2.4 J/cm2). The fibroblast was randomly divided into six groups, control group, UVA radiated group and four protective groups(0.1 mg/ml LBP, 0.2 mg/ml LBP, 0.4 mg/ml LBP and 0.8 mg/ml LBP). The activities of cell proliferation were measured by MTT methods. The contents of MDA, the activities of SOD in the fibroblasts, and the activities of LDH in the supernatants of fibroblasts were determined by biochemical methods. Results The fibroblasts were irradiated by UVA (irradiation intensity: 2.4 J/cm2),the activities of cell proliferation was decreased,the activities of SOD was decreased too, the content of MDA and LDH increased. Compared with UVA irradiated group,in the given concentration,LBP could improve the activities of cell’s proliferation,improve the activities of SOD and decrease the contents of MDA in the cell, and decrease the content of LDH in the supernatants of cells significantly (P

Objective To study the adverse effect of omethoate on DNA in mouse sperm cells in vivo. Single cell gel electrophoresiss (SCGE) or comet assay was used to observe the damage of DNA. Methods 40 male kunming mice were randomly divided into 4 groups and were treated with omethoate by gavage at 0 mg/kg, 0.5 mg/kg, 1 mg/kg and 2 mg/kg respectively, once a day for 35 consecutive days. Results The movement and density of sperms decreased as the dose of omethoate increased, the length of comet tails in group of 1 mg/kg and group of 2 mg/kg was much longer than that in the control, the other indexes of comet assay also showed significant DNA damage. Conclusion Omethoate exposure can induce DNA damage in the sperm cells of male mice.

Objective To explore the relationship between trace elements proportion in food and health. Methods 45 mice aged 12 month were randomly divided into 3 groups: control group(n=16) and two experimental groups(n=15).The mice in the experimental groups were given Zn, Li, Fe, Se, Mn, Cu, Co in different proportion by food for 60 days, then all mice were sacrificed, thymus weight, spleen weight, thymus coefficient, spleen coefficient, bone indexes were determined. Results Supplementation of the trace elements in food increased the content of Ca2+ in the bone of the aged mice and proportion variety of trace elements might induce the changes of thymus weight, spleen weight, spleen coefficient and bone indexes. Conclusion The reasonable proportion of trace elements in food could increase the content of bone Ca2+ in aged mice.

Objective To investigate the relationship between the content of iodide in water and children goiter in the high iodide areas. Methods Pupils aged 8-10 years from 17 primary schools in 10 towns of Huimin county, Yangxin county, Wudi county, Bincheng county were chosen. Based on the contents of water iodide,the pupils were divided into groups, the prevalence of goiter and the content of urinary iodide were determined. Results The prevalence of goiter in the children aged 8-10 was 18.8%,the prevalence showed an increasing tendency. In a certain range, increase of content of iodide in water did not caused an increased prevalence of goiter. There was no association was found between the content of iodide in water and the prevalence of goiter. Conclusion According to the results of the present paper, despite the contents of iodide in drinking water meets the standard of high iodide area, there is still no dose-effect relationship between the prevalence of goiter in the children aged 8-10 years and the content of iodide in water, whereas as the high iodide exposure time prolong, the prevalence of goiter demonstrates an increase tendency.