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11.
To evaluate mercury (Hg) exposure and possible adverse effects of Hg on American dipper (Cinclus mexicanus) reproduction, we collected eggs and nestling feathers and the larval/nymph form of three Orders of aquatic macroinvertebrates (Ephemeroptera, Plecoptera and Trichoptera = EPT) important in their diet from three major headwater tributaries of the upper Willamette River, Oregon in 2002. The Coast Fork Willamette River is contaminated with Hg due to historical cinnabar (HgS) mining at the Black Butte Mine; the Row River is affected by past gold-mining operations located within the Bohemia Mining District, where Hg was used in the amalgamation process to recover gold; and the Middle Fork Willamette River is the reference area with no known mining. Methyl mercury (MeHg) concentrations (geometric mean) in composite EPT larvae (111.9 ng/g dry weight [dw] or 19.8 ng/g wet weight [ww]), dipper eggs (38.5 ng/g ww) and nestling feathers (1158 ng/g ww) collected from the Coast Fork Willamette were significantly higher than MeHg concentrations in EPT and dipper samples from other streams. Total mercury (THg) concentrations in surface sediments along the same Hg-impacted streams were investigated by others in 1999 (Row River tributaries) and 2002 (Coast Fork). The reported sediment THg concentrations paralleled our biological findings. Dipper breeding territories at higher elevations had fewer second clutches; however, dipper reproductive success along all streams (including the lower elevation and most Hg-contaminated Coast Fork), was judged excellent compared to other studies reviewed. Furthermore, MeHg concentrations in EPT samples from this study were well below dietary concentrations in other aquatic bird species, such as loons and ducks, reported to cause Hg-related reproductive problems. Our data suggest that either dipper feathers or EPT composites used to project MeHg concentrations in dipper feathers (with biomagnification factor of 10–20×) may be used, but with caution, to screen headwater streams for potential Hg-related effects on dippers. When actual feather concentrations or projected feather concentrations are equal to or lower than concentrations reported for the Coast Fork, dippers are expected to reproduce well (assuming adequate prey and suitable nest sites). When Hg concentrations are substantially higher, more detailed investigations may be required. Birds feeding almost exclusively on fish (e.g., osprey [Pandion haliaetus]) and usually found further downstream from the headwaters would not be adequately represented by dippers given the higher MeHg concentrations in fish resulting from biomagnification, compared to lower trophic level invertebrates.  相似文献   
12.
《Vaccine》2020,38(6):1526-1534
Despite decades of vaccination, surveillance, and biosecurity measures, H5N2 low pathogenicity avian influenza (LPAI) virus infections continue in Mexico and neighboring countries. One explanation for tenacity of H5N2 LPAI in Mexico is the antigenic divergence of circulating field viruses compared to licensed vaccines due to antigenic drift. Our phylogenetic analysis indicates that the H5N2 LPAI viruses circulating in Mexico and neighboring countries since 1994 have undergone antigenic drift away from vaccine seed strains. Here we evaluated the efficacy of a new recombinant fowlpox virus vector containing an updated H5 insert (rFPV-H5/2016), more relevant to the current strains circulating in Mexico. We tested the vaccine efficacy against a closely related subcluster 4 Mexican H5N2 LPAI (2010 H5/LP) virus and the historic H5N2 HPAI (1995 H5/HP) virus in White Leghorn chickens. The rFPV-H5/2016 vaccine provided hemagglutinin inhibition (HI) titers pre-challenge against viral antigens from both challenge viruses in almost 100% of the immunized birds, with no differences in number of birds seroconverting or HI titers among all tested doses (1.5, 2.0, and 3.1 log10 mean tissue culture infectious doses/bird). The vaccine conferred 100% clinical protection and a significant decrease in oral and cloacal virus shedding from 1995 H5/HP virus challenged birds when compared to the sham controls at all tested doses. Virus shedding titers from vaccinated 2010 H5/LP virus challenged birds significantly decreased compared to sham birds especially at earlier time points. Our results confirm the efficacy of the new rFPV-H5/2016 against antigenic drift of LPAI virus in Mexico and suggest that this vaccine would be a good candidate, likely as a primer in a prime-boost vaccination program.  相似文献   
13.
目的了解河南大学新校区土壤中蛔虫卵及鞭虫卵污染情况及影响因素,为制订防治对策提供科学依据,为校园绿化工作提供相关评价依据。方法在校园中的药生植物园、湖边、荒地、草丛等地区采取土壤标本进行蛔虫卵和鞭虫卵的检测。结果土壤蛔虫卵、鞭虫卵的阳性率分别是18.8%和20%;其中药生植物园两种虫卵阳性率均高达35%。结论加强高校新校区土壤的无害化处理,加强校园绿化管理,防止土源性线虫感染人群是一项重要而艰巨的任务。  相似文献   
14.
《Vaccine》2021,39(14):1933-1942
The genetic and antigenic drift associated with the high pathogenicity avian influenza (HPAI) viruses of Goose/Guangdong (Gs/GD) lineage and the emergence of vaccine-resistant field viruses underscores the need for a broadly protective H5 influenza A vaccine. Here, we tested experimental vector herpesvirus of turkey (vHVT)-H5 vaccines containing either wild-type clade 2.3.4.4A-derived H5 inserts or computationally optimized broadly reactive antigen (COBRA) inserts with challenge by homologous and genetically divergent H5 HPAI Gs/GD lineage viruses in chickens. Direct assessment of protection was confirmed for all the tested constructs, which provided clinical protection against the homologous and heterologous H5 HPAI Gs/GD challenge viruses and significantly decreased oropharyngeal shedding titers compared to the sham vaccine. The cross reactivity was assessed by hemagglutinin inhibition (HI) and focus reduction assay against a panel of phylogenetically and antigenically diverse H5 strains. The COBRA-derived H5 inserts elicited antibody responses against antigenically diverse strains, while the wild-type-derived H5 vaccines elicited protection mostly against close antigenically related clades 2.3.4.4A and 2.3.4.4D viruses. In conclusion, the HVT vector, a widely used replicating vaccine platform in poultry, with H5 insert provides clinical protection and significant reduction of viral shedding against homologous and heterologous challenge. In addition, the COBRA-derived inserts have the potential to be used against antigenically distinct co-circulating viruses and future drift variants.  相似文献   
15.
The objective of the current modeling analysis was three-fold: (1) to examine usual nutrient intakes in children when eggs are added into dietary patterns that typically do not contain eggs; (2) to examine usual nutrient intakes with the addition of eggs in the Child and Adult Care Food Program (CACFP) school breakfast; and (3) to examine nutrient adequacy when eggs are included in routine breakfast patterns and with the addition of eggs to the CACFP school breakfast program. Dietary recall data from the National Health and Nutrition Examination Survey 2011–2016 (children aged 1–18 years-old; n = 9254; CACFP n = 159) were used in the analysis. The usual intakes of pantothenic acid, riboflavin, selenium, and vitamin D increased ≥10 percent (relative to the baseline values) with the addition of one egg at breakfast. The usual intakes of protein and vitamin A at breakfast were also increased by more than 10 percent compared to the baseline values with the addition of two eggs. Similar outcomes were observed with the addition of eggs to the CACFP school breakfast. The percent of children above the adequate intake for total choline increased to 43.6 and 57.8% with one and two eggs, respectively, compared to 22.6% at the baseline. The addition of eggs at breakfast can contribute to nutrient intakes and overall dietary adequacy and play a role in public health initiatives aimed at increasing the intake of under-consumed nutrients and nutrients of concern.  相似文献   
16.
To evaluate the Toxocara spp. eggs environmental contamination of the soil of the urban or suburban area Ancona (Italy), 22 public playgrounds were selected and several cores of soil were taken from any selected areas. To study the Toxocara seroprevalence in the inhabitants of Ancona, blood samples were collected from selected groups of individuals. One hundred and sixty-three blood samples were tested using an enzyme linked immunosorbent assay (ELISA) technique (Lofarma Lab, Milan, Italy) for the detection of IgG-specific antibodies to T.canis excretory–secretory antigens. Toxocara spp. eggs were found in the soil samples from 14 (63.6%) playgrounds. Toxocara seroprevalence was detected in blood specimens from six (8.1%) out of 74 symptomatic individuals and from one (1.1%) out of 89 asymptomatic controls. Among symptomatic individuals, the association between Toxocara seroprevalence and eosinophilia resulted statistically significant (p = 0.029). The high environmental contamination frequency found make necessary to prompt preventive public health measures, such as control of stray animals, treatment of infected pets and hygiene education of the population.  相似文献   
17.
In England and Wales, the emergence of Salmonella enterica serovar Enteritidis resulted in the largest and most persistent epidemic of foodborne infection attributable to a single subtype of any pathogen since systematic national microbiological surveillance was established. We reviewed 67 years of surveillance data to examine the features, underlying causes, and overall effects of S. enterica ser. Enteritidis. The epidemic was associated with the consumption of contaminated chicken meat and eggs, and a decline in the number of infections began after the adoption of vaccination and other measures in production and distribution of chicken meat and eggs. We estimate that >525,000 persons became ill during the course of the epidemic, which caused a total of 6,750,000 days of illness, 27,000 hospitalizations, and 2,000 deaths. Measures undertaken to control the epidemic have resulted in a major reduction in foodborne disease in England and Wales.  相似文献   
18.
海胆黄多糖SEP的制备及其抗肿瘤作用研究   总被引:1,自引:0,他引:1  
建立荷瘤小鼠模型,以不同剂量的SEP经腹腔注射给药后检测荷瘤小鼠的肿瘤生长情况、脾指数、胸腺指数、脾淋巴细胞增殖和抗氧化酶活性研究海胆黄多糖SEP的抗肿瘤活性。结果:SEP高、中、低3个剂量组均可显著抑制S180实体瘤的生长,其抑瘤率分别为46.9%、41.7%和40.7%;SEP能显著提高荷瘤小鼠的脾指数和胸腺指数,明显促进脾淋巴细胞的增殖,显著降低小鼠血清中丙二醛含量和提高超氧化物歧化酶活性。结论:SEP具有明显的抗肿瘤活性,其作用可能是通过免疫调节和抗氧化作用实现的。  相似文献   
19.
目的了解四川省土源性线虫监测点农村菜园、厕所周边、厨房和庭院土壤中蛔虫卵的污染情况,为制定防治对策提供科学依据。方法采用饱和硝酸钠漂浮法检查土壤蛔虫卵污染情况。结果四川省土源性线虫监测点土壤中蛔虫卵检出率10%,活受精蛔虫卵检出率5.50%。菜园、厕所周边、厨房和庭院4种场所土壤中蛔虫卵检出率分别为13.00%、10.00%9、.00%和8.00%。结论四川省农村土壤环境中有蛔虫卵污染,今后防治工作中应引起重视。  相似文献   
20.
《Nutrition reviews》1985,43(9):263-265
Feeding three to six eggs per-day increases plasma LDL and HDL cholesterol levels in about 50 percent of normocholesterolemic subjects. This effect is blunted by increasing the dietary P/S to 1.0.  相似文献   
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