[Pollution Characteristics and Ecological Risk Assessment of Organochlorine Pesticides in Water Source Areas of Guangdong and Guangxi].

The concentrations of 16 organochlorine pesticides (OCPs) in 7 water samples collected from different sites of water source areas of Guangdong and Guangxi were detected by SPE-GC-MS, and then the pollution characteristics were analyzed. This study established species sensitivity distribution(SSD) curves with BurrⅢ distribution model. In the meantime, HC5 values were calculated by BurrliOZ software, which were used to evaluate the toxicity effects of OCPs towards aquatic organisms. Finally, margin of safety concentration values were calculated to assess the ecological risk. The results showed that the concentration of OCPs varied from 6.64 to 34.19 ng·L-1, with a mean value of 16.76 ng·L-1, while HCHs and DDTs contributed a lot. HCHs were predominately originated from lindane, which is a component in household insecticide, while DDTs were from dicofol contamination or historical residues. Vertebrates could stand severer toxicity in comparison with invertebrates. α-endosulfan showed a greater toxicity towards aquatic plants and microorganisms than others, while p, p'-DDT turned out to be the most hazardous pollutant to vertebrates and invertebrates among the 16 OCPs studied. Generally speaking, OCPs in study areas didn't show conspicuous ecological risks towards aquatic organisms, DDTs and α-endosulfan, however, are still worth paying close attention due to their high potential risks.

[Analysis of endemic situation of schistosomiasis in Yugan County of Jiangxi Province in 2012].

OBJECTIVE: To master the epidemic situation and control effect of schistosomiasis in Yugan County, Jiangxi Province. METHODS: The data of the schistosomiasis prevalence in human and cattle as well as Oncomelania hupensis snail status were collected and the change trends were analyzed in Yugan County from 2008 to 2012. RESULTS: The schistosome infection rates of residents in Yugan County have declined every year since 2008, and currently, the prevalence of schistosomiasis was at a low level. No acute schistosomiasis case was found during the past 5 years. In 2012, the infection rate of bovine was above 1% in 88 endemic villages, and the area with schistosome infected snails was 10 hm2. CONCLUSION: In order to achieve the goal of schistosomiasis transmission control in the whole county in 2015, the comprehensive control measures based on infection source control should be strengthened.

[Effects of teriparatide and alendronate on bone mineral density of osteoporotic rats].

OBJECTIVE: To investigate the effects of teriparatide (hPTH1-34, PTH) and alendronate (Alen) on bone turnover rate and bone mineral density (BMD) of ovariectomized (OVX) osteoporotic rats. METHODS: 70 female 6-month-old Wistar rats were randomly divided into 7 groups: (1) baseline group: killed immediately as baseline controls; (2) sham operation group: injected subcutaneously with normal saline (NS) as normal controls; (3) OVXb group: underwent ovarietomy (OVX) and killed 6 weeks after OVX as pre-therapeutic controls; (4) OVXe group: injected with NS subcutaneously and then sacrificed 14 weeks after OVX as controls by the end of treatment; (5) PTH group: PTH 40 microg.kg(-1).d(-1) was administered; (6) Alen group: Alen 100 microg.kg(-1).d(-1) was administered; (7) A + P group: PTH 40 microg.kg(-1).d(-1) and Alen 100microg.kg(-1).d(-1) were administered. In groups 4 approximately 7, different medicines were injected subcutaneously QD 5 times per week from the 6th week to the 14th week after OVX and then the rats were killed and their right femurs, lumbar vertebrae, and samples of blood and urine were collected. Absorptometry was used to measure the BMD of the right femur and lumbar vertebrae. The serum calcium, phosphate, creatinine, alanine transaminase, and alkaline phosphatase (ALP) activity were measured by automatic biochemical analysis. The bone resorption marker urine deoxypyridinoline/creatinine (UDpd/Cr) level was measured by enzyme-linked immuosorbent assay. RESULTS: Six weeks after OVX the ALP and UDpd/Cr levels in the OVXb group were 101 U/L +/- 59 U/L and (118 +/- 32) x 10(-6) respectively, both significantly higher than those of the baseline group (58 U/L +/- 10 U/L and (48 +/- 34) x 10(-6) respectively, both P < 0.01) and the BMD results of the OVXb group were all significantly lower than those in the baseline group (all P < 0.01), which indicated that an OVX osteoporotic rat model was established successfully. The ALP and UDpd/Cr levels of the Alen group were 61 U/L +/- 28 U/L and (17 +/- 39) x 10(-6), significantly lower than those of the PTH group 120 U/L +/- 36 U/L and (111 +/- 26) x 10(-6) respectively, both P < 0.01) and the UDpd/Cr levels of the A + P group were between those of the Alen group and those of the PTH group. The BMD levels of the femur and lumbar vertebrae of the PTH, Alen, and A + P groups were all significantly higher than those of the control groups (all P < 0.01), and were similar to or higher than those of the sham operation group without significant differences between the PTH and Alen groups. The BMD level of the lumber vertebrae of the A + P group were significantly higher than those in the PTH group (all P < 0.05), and the femoral BMD results of the A + P group were significantly higher than those in the PTH and Alen groups (all P < 0.01). CONCLUSION: PTH and Alen are all effective on osteoporosis. In particular, the combination of PTH and Alen is more effective on increasing the BMD level.

[Leptin and clustering of the components of risk factors for metabolic syndrome].

OBJECTIVES: To evaluate relationship between serum level of leptin and the components of risk factors for metabolic syndrome and to analyze the characteristics and laws of clustering of the risk factors. METHODS: Totally, 795 non-diabetic adult Chinese subjects (691 men and 104 women, aged 40 - 75 years) from a diabetes prevalence survey in 2000 were involved in this study. Measurements included serum levels of true insulin (TI), leptin, fasting lipids, fasting glucose (FBG) and 2 h postchallenge glucose, as well as seated blood pressure (BP), body mass index (BMI), ratio of waist circumference to hip circumference (WHR), calculated quantitative insulin sensitivity check index (QUICKI), etc. Relationship between serum level of leptin and all the variables mentioned above was studied by statistical methods such as factor analysis, etc. RESULTS: Serum level of leptin in the study subjects increased with the number of components of abnormal metabolism they had. Detection rates of obesity, hypertension, dyslipidemia and metabolic syndrome were significantly higher in those with the upper tertile of serum leptin level than in those with the lower tertile. Factor analysis revealed that variation of the 11 variables including serum level of leptin was affected by the three factors, i.e., the central factor associated with BMI, WHR, FTI, QUICKI and higher serum level of triglyceride (TG) and lower serum level of high-density lipoprotein-cholesterol (HDL-C), the glucose intolerance factor loaded with blood glucose level, FTI, QUICKI and higher serum level of TG (in women only) and the hypertension factor loaded with blood pressure and BMI (in men only), which could explain 62.0% and 66.7% of total variance in men and women, respectively, and higher serum level of TI and insulin resistance also loaded with both the central factor and glucose tolerance factor. CONCLUSIONS: Serum level of leptin was significantly associated with the key markers of metabolic syndrome. Hyperleptinaemia could be a new component of metabolic syndrome. Clustering of the risk factors for metabolic syndrome could be affected by many factors, and although insulin resistance played an important role in it, insulin resistance alone could not explain its etiology.

[Role of leptin in the pathogenesis of obesity-related hypertension].

OBJECTIVE: To assess the role of leptin in the pathogenesis of obesity-related hypertension and the relationship between blood pressure (BP), and body mass index (BMI), insulin resistance and leptin were examined. METHODS: 560 non-diabetic men, aged 35 - 75, selected from volunteers of health screening test during 2 000 were divided into hypertension group (n = 321, BP >or= 140/90 mm Hg without antihypertensive medication). and normal blood pressure group (n = 239). The body weight, waist hip ratio,BP, plasma glucose, serum lipids, true insulin (TI) and leptin were measured after overnight fast. Insulin sensitivity was assessed by the HOMA insulin resistance index (HOMA-R). RESULTS: Fasting leptin level showed good correlation with BMI, fasting TI, HOMA-R, BP and also triglycerides (all P < 0.01). After adjustment for age, BMI and HOMA-R, serum leptin was still positively correlated to SBP (r = 0.11, P < 0.05), and was significantly higher in hypertensive subjects than in normotensive subjects (geometric mean 6.4 vs 4.7 micro g/L, P < 0.001). Logistic regression analysis demonstrated that leptin remained significantly associated with hypertension after adjustment for potentially confounding factors. CONCLUSION: Leptin may play an important role in the pathogenesis of obesity related hypertension.

[Precision of rat BMD measurements by dual-energy X-ray absorptiometry in vitro].

OBJECTIVE: To evaluate the precision of rat bone mineral density (BMD) measurements by Norland Excellplus dual-energy X-ray absorptiometry (DXA) and to investigate the BMD changes in ovariectomized (Ovx) rats in vitro. METHODS: (1) The coefficients of variation (CV) for BMD measurements at various skeletal regions were repeatedly determined by DXA in 10 Wistar rats in vitro. (2) BMD in lumbar vertebra (L5) and both sides of femurs was measured in total 90 rats. And (3) changes in BMD between Ovx and sham rats were compared. RESULTS: (1) The short-term CVs of BMD measurements in different regions by DXA were as follows, 1.58% for lumbar vertebra (L5), 0.90% for left femur, and 0.86% for right femur, respectively. The long-term CVs were 2.22% for lumbar vertebra (L5), 1.09% for left femur, and 1.20% for right femur. (2) The BMD values in 90 Wistar rats were (127.5 +/- 12.3) in lumbar vertebra (L5), (82.6 +/- 11.3) in corpus vertebra (L5'), (150.7 +/- 10.6) in left femur and (149.9 +/- 10.6) mg/cm2 in right femur, respectively. The correlation coefficient of BMD measurements between left and right femurs was 0.792 (P < 0.001). (3) In Ovx group, the BMD values of corpus vertebra (L5') and distal femurs were significantly decreased, that was 10.0%-17.5% lower in comparison with sham group (P < 0.001). CONCLUSIONS: Measurement of rat BMD in vitro by Norland Excellplus DXA is a useful method, and it can reflect the changes in rat bone masses with good precision.