Anti-implantation and anti-fertility potentials of Anethum graveolens L. extracts in rats

Ovarian hormones affected some enzymes in reproductive tissues. Previous studies revealed Anethum graveolens (dill) seed extract elevated ovarian hormones. In this study, we compared the effects of dill seed and leaf extracts on some enzymes activities and infertility potential. Female Wistar rats were divided into three groups of control, dill seed and dill leaf aqueous extracts treated groups. Experimental groups received 1 mL of 0.5 g kg^?1 of each extract orally for 25 days (five estrous cycles). Estradiol, progesterone, luteinizing hormone, and follicle stimulating hormone concentrations were determined. Uterus and ovaries were removed and their glucose-6-phosphate dehydrogenase, lactate dehydrogenase, and alkaline phosphatase activities were measured. Female rats of three groups were mated with untreated males. Fetuses were extracted in the 20th gestational day and their weights and crown rump lengths were measured. Anti-fertility and anti-implantation activities and fertility indices were calculated. Glucose-6-phosphate activity of dill seed treated group increased 1.6 times in the endometrium and 1.7 times in the myometrium. Progesterone concentration and lactate dehydrogenase activity of serum increased in the dill seed treated group compared to the control and dill leaf treated group. A significant decrease was observed in weights and crown rump lengths of fetuses, weights of placenta, and fertility index of the dill seed treated group compared to the control and dill leaf treated group, but its anti-implantation and anti-fertility indices increased. We suggested that high level of glucose-6-phosphate could entail increased oxidative stress in uterus and ovary. High lactate dehydrogenase activity in serum may affect cell membranes. Higher secretion of progesterone caused hormonal imbalance and produced estrous cycle irregularity. It was concluded that dill seed but not dill leaf extract could induce infertility in an animal model.     

COD/N与pH值对短程硝化反硝化过程中N2O产生的影响

利用SBR反应器,通过投加乙醇控制COD/N为0、1.5、3、4.5,调节pH值分别在6、7、8,反硝化初始投加NO2--N为30mg/L,考察了缺氧条件下COD/N与pH值对短程硝化反硝化过程中N2O产量的影响.结果表明:低COD/N可以造成N2O持续较高的逸出,N2O最大产生量为2.35mg/L;低pH值条件下增加了N2O的积累,pH值在6时的N2O积累量是pH在7、8时的800倍;高COD/N和高pH值下的N2O产生速率最小,而当pH=6,COD/N=0时,N2O产生速率最大,为2.35×10-3mgN/(mgMLSS?L?h).其原因是:N2O还原酶争夺电子的能力较弱,充足的电子供体有利于N2O的还原;低pH值可影响微生物的代谢,且在H+存在时产生的游离亚硝酸(HNO2)对N2O还原酶具有抑制作用.充足的碳源和碱性条件,是降低短程硝化反硝化过程中N2O产量的关键因素.     

典型平原河网区水体富营养化特征、成因分析及控制对策研究

本文以嘉兴市北部湖荡区为典型研究区域,通过现场调研、来源分析等,揭示了平原河网区水体富营养化状态,明确了水污染主要成因,并提出控制对策.研究结果显示,北部湖荡区总磷、高锰酸盐指数、五日生化需氧量、化学需氧量、总氮、氨氮等各污染物含量呈现显著的时空分布特征,西部片区水质较东部片区差,5月水质较9月差(总磷除外);富营养化...     

Population Consequences of Environmental Sex Reversal

Abstract:  When sex determination in a species is predominantly genetic but environmentally reversible, exposure to (anthropogenic) changes in the environment can lead to shifts in a population's sex ratio. Such scenarios may be common in many fishes and amphibians, yet their ramifications remain largely unexplored. We used a simple model to study the (short-term) population consequences of environmental sex reversal (ESR). We examined the effects on sex ratios, sex chromosome frequencies, and population growth and persistence after exposure to environmental forces with feminizing or masculinizing tendencies. When environmental feminization was strong, X chromosomes were driven to extinction. Analogously, extinction of normally male-linked genetic factors (e.g., Y chromosomes) was caused by continuous environmental masculinization. Although moderate feminization was beneficial for population growth in the absence of large viability effects, our results suggest that the consequences of ESR are generally negative in terms of population size and the persistence of sex chromosomes. Extreme sex ratios resulting from high rates of ESR also reduced effective population sizes considerably. This may limit any evolutionary response to the deleterious effects of ESR. Our findings suggest that ESR changes population growth and sex ratios in some counter-intuitive ways and can change the predominant factor in sex determination from genetic to fully environmental, often within only a few tens of generations. Populations that lose genetic sex determination may quickly go extinct if the environmental forces that cause sex reversal cease.     

双子地震P波谱比在地震短期预报中的应用研究

应用法国地震学家G.Poup inet等关于双子地震的有关理论,对云南地震台网数字地震资料开展应用研究,通过基线校正、数字滤波、波形对比等方法获得8对3级双子地震和武定地震易门台7对双子地震。对以上双子地震取起始3秒P波作富氏谱分析后进行谱比对数的斜率拟合。结果显示,由发生在6.5级姚安地震前7个月之内与之外时段的地震构成的双子地震,其P波谱比对数斜率绝对值都达到0.030以上,明显高于均由震前7个月之外发生的地震构成的双子地震谱比对数斜率;在距主震2°范围以内的台站可观测到双子波发生的变化。常熟台双子地震P波谱比对数斜率时间进程在南黄海地震发生之前也存在这一现象,但出现异常的时间扩大到9个月之内。     

Maternal exposure to high levels of dioxins in relation to birth weight in women affected by Yusho disease

Background

Studies on the association of maternal exposure to polychlorinated dibenzo-p-dioxin (PCDDs), polychlorinated dibenzofurans (PCDFs), and polychlorinated biphenyls (PCBs) with decreased birth weight in humans have produced conflicting results. In Japan in 1968, an accidental human exposure to rice oil contaminated with PCDDs, PCDFs, and PCBs, led to the development of Yusho disease.

Objective

The Yusho cohort was used to evaluate the effect of maternal exposure to PCDDs, PCDFs, and PCBs on birth weight.

Methods

Blood samples, obtained from 101 Yusho women (190 births) who gave birth after exposure, were analyzed for congeners of seven PCDDs, ten PCDFs, and four non-ortho PCBs.

Results

Total PCDD TEQ (adjusted beta = − 161.9 g; 95% CI, −265.3 to − 58.6), total PCDF TEQ (adjusted beta = − 105.9 g; 95% CI, −179.5 to − 32.2), and total non-ortho PCBs (adjusted beta = − 178.4 g; 95% CI, −318.3 to − 38.5) levels were inversely associated with birth weight. Significant inverse associations with birth weight were also found for total PCDD TEQ, total PCDF TEQ, and total non-ortho PCB TEQ levels among male, but not female, infants. Significant inverse associations with birth weight were also found for nine congeners among all infants; the adjusted beta coefficients were largest for 1,2,3,6,7,8-HxCDD and smallest for 2,3,4,7,8-PeCDF.

Conclusion

In the setting of exposure to high levels of dioxins, maternal blood levels of PCDDs, PCDFs and PCBs are associated with lower birth weight in Yusho patients. The association exhibited gender-specific differences, as male infants are more susceptible than females to growth restriction induced by in utero dioxin exposures.     

Metal contamination in the lichen Alectoria sarmentosa near the copper smelter of Murdochville, Québec

Lichens were used to evaluate the metal pollution in a forest ecosystem around the smelter of Murdochville, Canada. As reached values 5.8 times higher in the smelter vicinity than in the 'background' sites. This enrichment was 2 times higher for 3 metals (Cu, Cd and Pb). The highest As, Ba, Cd, Cu, and Pb concentrations in lichens were 4, 112, 1, 23, 50 and 952mg/kg respectively. Contamination declined exponentially with increasing distance from the smelter and was related to elevation and slope exposition to the smelter flux. (206)Pb/(207)Pb and (206)Pb/(204)Pb ratios were low close to the smelter (1.16 and 18), but increased with distance to constant values (1.19 and 18.7) and showed an inverse correlation with lead concentrations. Forest contamination was detectable up to 30km from the smelter.     

Depleted uranium mobility and fractionation in contaminated soil (Southern Serbia)

GOAL, SCOPE AND BACKGROUND: During the Balkan conflict in 1999, soil in contaminated areas was enriched in depleted uranium (DU) isotopic signature, relative to the in-situ natural uranium present. After the military activities, most of kinetic DU penetrators or their fragments remained buried in the ground in certain geomorphological and geochemical environments exposed to local weathering conditions. The contamination distribution, mobility and/or fixation of DU in the contaminated soil profile at one hot spot were the subject of our study. The results should disclose what happened with released DU corrosion products in three years elapsed, given the scope of their geochemical fractionation, and mark out the most probable host substrates in investigated soil type. METHODS: Gamma-spectrometric analysis of soil samples taken in the DU penetrator impact-zone was done to obtain present contamination levels. Set of samples is subjected to five-step and three-step sequential extraction procedures, specifically selective to different physical/chemical associations in soil. The stable elements are determined in extracts by the atomic absorption spectroscopy. After the ion-exchange based uranium separation procedure, alpha-spectrometric analysis of obtained fractions was done and DU distribution in five extraction phases found from 235U/238U and 234U/238U isotopic ratios. RESULTS: Depleted uranium concentration falls down to the 1% of the initial value, at approximately 150 mm distance to the source. Carbonates and iron/manganese hydrous oxides are indicated as the most probable substrates for depleted uranium in the characterized soil type. Therefore, in the highly contaminated soil samples, depleted uranium is still weakly bonded and easy exchangeable. The significant levels of organic-bonded depleted uranium are found in surface soil only. DISCUSSION: Dependence of the fractionation on the contamination levels is evident. Samples with higher DU contents have shown a longer maintenance in the exchangeable phases, probably because adsorption/desorption mass transfer through the medium was not very fast. Organic-bonded, depleted uranium is present in surface soil samples due to its higher humus content. Considering geochemical composition of investigated soil, the indicating chemical associations as substrates are in agreement with some considerations based on the results for low-level waste unsaturated zones. CONCLUSIONS: The soil contamination with depleted uranium in investigated area is still 'spot' type and not widespread. Dependence of the fractionation on the contamination levels and presence of weakly bonded, depleted uranium in the hot spots areas is evident. RECOMMENDATIONS AND PERSPECTIVES: A detailed study may be undertaken with suitable extractive reagents to define a bio-available fraction of depleted uranium in soil. The comparison of results for different soil types investigated by the same methodology may be useful. An applied combination of physical/chemical procedures and analysis may help in the decision making on the remediation strategy for sites contaminated with depleted uranium used in military operations.     

Selected endocrine disrupting compounds (Vinclozolin,Flutamide, Ketoconazole and Dicofol): Effects on survival,occurrence of males,growth, molting and reproduction of <Emphasis Type="Italic">Daphnia magna</Emphasis>

BACKGROUND, AIM AND SCOPE: Pollution-induced endocrine disruption in vertebrates and invertebrates is a worldwide environmental problem, but relatively little is known about effects of endocrine disrupting compounds (EDCs) in planktonic crustaceans (including Daphnia magna). Aims of the present study were to investigate acute 48 h toxicity and sub-chronic (4-6 days) and chronic (21 days) effects of selected EDCs in D. magna. We have investigated both traditional endpoints as well as other parameters such as sex determination, maturation, molting or embryogenesis in order to evaluate the sensitivity and possible use of these endpoints in ecological risk assessment. MATERIALS AND METHODS: We have studied effects of four model EDCs (vinclozolin, flutamide, ketoconazole and dicofol) on D. magna using (i) an acute 48 h immobilization assay, (ii) a sub-chronic, 4-6 day assay evaluating development and the sex ratio of neonates, and (iii) a chronic, 21 day assay studying number of neonates, sex of neonates, molting frequency, day of maturation and the growth of maternal organisms. RESULTS: Acute EC50 values in the 48 h immobilization test were as follows (mg/L): dicofol 0.2, ketoconazole 1.5, flutamide 2.7, vinclozolin >3. Short-term, 4-6 day assays with sublethal concentrations showed that the sex ratio in Daphnia was modulated by vinclozolin (decreased number of neonate males at 1 mg/L) and dicofol (increase in males at 0.1 mg/L). Flutamide (up to 1 mg/L) had no effect on the sex of neonates, but inhibited embryonic development at certain stages during chronic assay, resulting in abortions. Ketoconazole had no significant effects on the studied processes up to 1 mg/L. DISCUSSION: Sex ratio modulations by some chemicals (vinclozolin and dicofol) corresponded to the known action of these compounds in vertebrates (i.e. anti-androgenicity and anti-oestrogenicity, respectively). Our study revealed that some chemicals known to affect steroid-regulated processes in vertebrates can also affect sublethal endpoints (e.g. embryonic sex determination and/or reproduction) in invertebrates such as D. magna. CONCLUSIONS: A series of model vertebrate endocrine disrupters affected various sub-chronic and chronic parameters in D. magna including several endpoints that have not been previously studied in detail (such as sex determination in neonates, embryogenesis, molting and maturation). Evaluations of traditional reproduction parameters (obtained from the 21 day chronic assay). as well as the results from a rapid, 4-6 day, sub-chronic assay provide complementary information on non-lethal effects of suspected organic endocrine disrupters. RECOMMENDATIONS AND PERSPECTIVES: It seems that there are analogies between vertebrates and invertebrates in toxicity mechanisms and in vivo effects of endocrine disruptors. However, general physiological status of organisms may also indirectly affect endpoints that are traditionally considered 'hormone regulated' (especially at higher effective concentrations as observed in this study) and these factors should be carefully considered. Further research of D. magna physiology and comparative studies with various EDCs will help to understand mechanisms of action as well as ecological risks of EDCs in the environment.