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381.
Susan J. Gross MD Owen P. Phillips Lee P. Shulman N. Lawrette Bright Jeffrey S. Dungan Joe Leigh Simpson Sherman Elias 《黑龙江环境通报》1994,14(7):609-613
An association between various abnormal mid-trimester maternal serum analyte values and adverse perinatal outcome has been reported. From an original sample of 14 857 women, we observed five women who were ‘screen-positive’ for both neural tube defects [maternal serum alpha-fetoprotein (MSAFP) ≥2·5 multiples of the median] and Down syndrome [risk ≥1/274 using MSAFP, maternal serum unconjugated oestriol (MSuE3), maternal serum human chorionic gonadotropin (MShCG), and maternal age]. The four patients who elected to undergo amniocentesis all demonstrated both normal karyotype and normal amniotic fluid AFP levels. All five cases were associated with intrauterine growth retardation (IUGR) and abnormal pregnancy outcomes. Two cases exhibiting severe IUGR on ultrasound examination were terminated at 19·1 and 21·2 weeks, respectively; the former also exhibited fetal calcifications and positive maternal serology for toxoplasmosis. In another case, fetal demise occurred at 36 weeks' gestation in a patient who had been treated for syphilis in the second trimester. Neither infection was confirmed in fetal tissue studies. Though resulting in live births, the remaining two cases required operative deliveries; emergency Caesarean sections for fetal distress were performed at 38 and 32 weeks, respectively, the latter case being associated with severe pre-eclampsia. We conclude that elevated mid-trimester MSAFP levels concurrent with maternal serum analyte values associated with increased risk for fetal Down syndrome may presage a poor perinatal outcome, particularly IUGR and possibly congenital infection. 相似文献
382.
We report our experience in ascertaining fetal triploidy during routine maternal serum alpha-fetoprotein (MSAFP) screening. Three cases were identified after elevated MSAFP tests. Two of the three had normal amniotic fluid alpha-fetoprotein (AFAFP). The third had amniocentesis too late for AFAFP interpretation. Three additional cases were detected by amniocentesis without prior MSAFP screening and none had an elevated AFAFP. A literature review revealed eight triploid fetuses detected as a result of an elevated MSAFP. Of the five with AFAFP quantitation, only one had an abnormal value and the elevation was minimal. In these 14 cases from our own and other reports, ultrasound findings of placental and fetal abnormalities were often noted, but a pattern diagnostic of triploidy was not present. We conclude that, for optimal prenatal detection of triploidy, fetal karyotyping should be included when an amniocentesis is performed for elevated MSAFP. 相似文献
383.
Enzyme-immunoassay techniques for the detection of atrazine in water samples: Evaluation of a commercial tube based assay 总被引:1,自引:0,他引:1
Environmental immunoassays can help lower the operating costs and improve the effectiveness of residue laboratories. The present study assesses the ability of a commercially available enzyme immunoassay (EIA) to detect triazine herbicides in water. The tube based EIA could detect atrazine in lake and river water with detection limits of 62 pg/mL and 180 pg/mL respectively. The assay's ability to quantify atrazine in a set of 124 water samples taken from many parts of Canada was compared with a reference method that used gas chromatographic separation combined with a nitrogen phosphorous detector (GC-NPD) (R=0.919). A 71 % reduction in analytical load was achieved at a threshold concentration of 1 ng/mL. There were 2.4 % false negative and 0.8 % false positive results associated with that load reduction. The variability of the assay control parameters was generally within two standard deviations of the mean response for 65 assays. The EIA for atrazine is recommended for use as a screening technique and as an inexpensive way to monitor triazine levels in waters that are known to be contaminated with those herbicides. 相似文献
384.
Introduction: Safety performance functions (SPF) are employed to predict crash counts at the different roadway elements. Several SPFs were developed for the various roadway elements based on different classifications such as functional classification and area type. Since a more detailed classification of roadway elements leads to more accurate crash predictions, multiple states have developed new classification systems to classify roads based on a comprehensive classification. In Florida, the new roadway context classification system incorporates geographic, demographic, and road characteristics information. Method: In this study, SPFs were developed in the framework of the FDOT roadway context classification system at three levels of modeling, context classification (CC-SPFs), area type (AT-SPFs), and statewide (SW-SPF) levels. Crash and traffic data from 2015-2019 were obtained. Road characteristics and road environment information have also been gathered along Florida roads for the SPF development. Results: The developed SPFs showed that there are several variables that influence the frequency of crashes, such as annual average daily traffic (AADT), signalized intersections and access point densities, speed limit, and shoulder width. However, there are other variables that did not have an influence in crash occurrence such as concrete surface and the presence of bicycle slots. CC-SPFs had the best performance among others. Moreover, network screening to determine the most problematic road segments has been accomplished. The results of the network screening indicated that the most problematic roads in Florida are the suburban commercial and the urban general roads. Practical Applications: This research provides a solid reference for decision-makers regarding crash prediction and safety improvement along Florida roads. 相似文献
385.
386.
为了解二噁英(PCDD/DFs)对成年男性类固醇激素水平的影响,采用高分辨气相色谱法/高分辨质谱联用法(HRGC/HRMS)及液相色谱-质谱联用法(LC-MS/MS)分析二噁英污染地区成年男性(n=50)及非污染地区成年男性(n=48)血清中9种类固醇激素水平和17种二噁英同类物浓度.结果显示成年男性血清中双氢睾酮、睾酮、雌二醇的水平与部分二噁英同类物浓度存在显著性相关.污染地区成年男性双氢睾酮、睾酮、雌二醇的水平与年龄呈显著性正相关.以上结果表明二噁英暴露导致成年男性类固醇激素中的性激素变化异常. 相似文献
387.
388.
S.?HeimEmail author J.?Schwarzbauer A.?Kronimus R.?Littke A.?Hembrock-Heger 《Environmental Chemistry Letters》2003,1(3):169-173
Organic-geochemical investigations were performed on layers of a dated sediment core taken from a riparian wetland of the Lippe river, Germany. The samples were collected from two distinct depth intervals representing sedimentation periods of 1944–1952 and 1972–1984, respectively. Comprehensive screening analyses by gas chromatography-mass spectrometry (GC-MS) revealed a complex mixture of anthropogenic contaminants. Here, we report the quantitative distribution of selected persistent lipophilic organic substances characterizing municipal as well as industrial emissions. Considering both geochemical and geochronological data, we deduced time-dependent information about industrial production and domestic effluents for the region investigated. In addition, usage and subsequent emission of characteristic pollutants into the riverine system were interpreted for both time periods monitored. 相似文献
389.
A simple enzyme immunoassay measuring human chorionic gonadotropin in undiluted maternal serum has been developed in order to be used as a prenatal screening test for Down' s syndrome. A retrospective study of maternal serum sampled during pregnancies associated with trisomy 21 shows that with a 5% amniocentesis rate determined on a single test, the detection rate of trisomy 21 would be around two-thirds of the affected pregnancies. A prospective study of 9040 pregnant women under 38 years has confirmed the usefulness of the assay. 相似文献
390.
Professor D. J. H. Brock Lilias Barron Susan Holloway W. A. Liston S. G. Hillier M. Seppala 《黑龙江环境通报》1990,10(4):245-251
A set of 21 early maternal serum samples (19 first-trimester and two at 14 weeks) from pregnancies resulting in a child with Down syndrome was matched for gestation and length of storage with 63 samples from unaffected pregnancies. The concentrations of alpha-fetoprotein (AFP), unconjugated oestriol (uE3), human chorionic gonadotrophin (hCG), pregnancy-specific β1–glycoprotein (SP1), and placental alkaline phosphatase (PALP) were measured. The ratios of the medians for Down syndrome pregnancies compared with the medians for controls were AFP 0·71, uE3 0·67, hCG 1·43, SP1 0·79, and PALP 0·92. Although the differences between the medians for affected and unaffected pregnancies were not significant, the trends for AFP, uE3, and hCG confirm earlier findings on first-trimester samples. 相似文献