水华蓝藻毒素研究概述

随着科技进步,发现的有毒种类越来越多,毒素分子结构的研究也越来越清楚。在大量文献的基础上,综合介绍水华微囊藻毒素、水华束丝藻毒素和水华鱼腥藻毒素对动物的毒害、毒素结构、检测方法和去除方法,并讨论存在的问题。     

成都站金属材料土壤腐蚀原位测试研究

通过对成都材料土壤腐蚀试验站金属材料腐蚀电位、腐蚀率及土壤环境因素的原位连续测试及定期测量土壤微生物方法,研究了碳钢、铝、铜、铅的土壤腐蚀规律。探讨了土壤环境因素及土壤微生物变化规律对金属材料的腐蚀影响。     

Prenatal diagnosis of osteogenesis imperfecta type III

Ultrasonographic and radiographic evaluation of a fetus at risk for osteogenesis imperfecta (O.I) type III was performed. Real-time ultrasound measurements at 15 weeks gestation were interpreted as normal, but at 20 and 22 weeks of gestation revealed marked shortening of the long bones and deformity of the femurs. The findings were confirmed by fetal radiography at 22 weeks gestation. Radiographic and histologic changes characteristic of O.I. were observed in the aborted fetus. Thus the antenatal manifestations of O.I. type III maybe severe enough to make prenatal diagnosis possible in the second trimester for families at risk for recurrence of this disorder.     

Temporal changes in Ohio amniocentesis utilization during the first twelve years (1972–1983), and frequency of chromosome abnormalities observed

The history of amniocentesis utilization in the seventh largest state of the United States is documented from its inception in 1972 through the first half of 1984. Amniocentesis utilization ratios for Ohio residents aged ⩾35 have increased from 0.21 per cent (19/9091) in 1972 to 23.4 per cent (1655/7531) in 1983, representing an average annual growth rate of 43.1 per cent. Of the amniocenteses performed from January 1, 1978–July 1, 1984, 71 per cent were referred for advanced maternal age (⩾35), 15 per cent for maternal anxiety (30–34), 10 per cent for family history or previous child with a genetic defect, and 4 per cent for other reasons. Between 1978-1983 utilization by women 45 years of age was only 20 per cent higher than women 35 even though their risk of giving birth to a Down syndrome child was about one order of magnitude higher. In addition, various factors were tested as to whether they affected utilization of amniocentesis by women ⩾35 during 1978 1983. A strong correlation of +0.89 existed between county population size and utilization ratios. No difference in utilization was found between whites and nonwhites, regardless of county population size. When utilization ratios were compared separately between Protestants, Catholics and other religions in Ohio's most populated county, no statistical differences were found. From 1978–July 1, 1984, the frequency of all cytogenetically abnormal chromosome results observed in Ohio amniocenteses to women ⩾35 was 2.48 per cent (187/7536). Of these, 2.15 per cent (162/7536) had unbalanced karyotypes. Future maximum amniocentesis utilization for women ⩾35 is estimated at 60–70 per cent.     

Listeriosis: A cause of non-immune hydrops fetalis

A case of prenatally diagnosed non-immune hydrops fetalis, that was later shown to be caused by listeriosis, is presented, and the clinical course, as well as the appropriate diagnostic and therapeutic procedures are described. We conclude, that listeriosis should be excluded, whenever a non-immune hydrops fetalis is associated with septicemia, influenza-like illness and fever of unknown origin.     

Ultrasound evaluation of pregnancies at risk for homozygous α-thalassaemia-1

Twenty-six pregnant Chinese women who were at risk of giving birth to a fetus affected with homozygous α-thalassaemia-1 were examined serially by ultrasound. Six of these 26 pregnancies were affected. In one third of the affected pregnancies progressive fetal ascites appeared before 24 weeks gestation and these pregnancies were terminated. In the remaining two thirds abnormal estimated fetal weight-placental volume (EFW-PV) ratio and fetal growth retardation as evidenced by a falling biparietal diameter (BPD), femur length (FL) but a normal abdominal circumference (AC) was apparent by 28 weeks gestation. Increased transverse cardiac (TC) diameter was another consistent finding but appeared late. All these features appeared before the onset of fetal ascites. A normal EFW-PV ratio and fetal growth until 28 weeks gestation was a reassuring sign of normality. Abnormal EFW-PV ratio was the earliest sign to appear in affected pregnancies and a normal ratio until 28 weeks gestation had a 100 per cent predictive value.     

Prenatal detection of a de novo duplication of the long arm of chromosome 7

Amniocentesis was performed for maternal age and subsequent cytogenetic studies revealed a male fetus with a mosaic karyotype, one cell line having a duplication for the long arm of chromosome 7. The pregnancy was terminated and the two cell lines confirmed in varying proportions in the fetal tissues. External examination of the fetus revealed only growth retardation and a high forehead. The lack of phenotypic defects and the possible aetiology of the de novo rearrangement are considered.     

Prenatal diagnosis of a new syndrome: Holoprosencephaly with hypokinesia

Markedly decreased fetal activity (akinesia/hypokinesia) is usually readily apparent to experienced mothers, and frequently this concern leads to attempts at prenatal diagnosis. We report prenatal diagnosis of two fetuses with congenital contractures, markedly decreased fetal movement, and microcephaly due to severe holoprosencephaly. Such familial recurrence to phenotypically normal parents suggests a newly recognized autosomal recessive or X-linked syndrome that is readily detectable by prenatal ultrasonography.     

耐候性试验在乘用车密封条研发中的应用

本文介绍了耐候性试验在乘用车密封条研发过程中的作用,对比分析了国内外测试标准间的差异,简述了有关乘用车密封条耐候性试验的研究进展。     

Cultivated cells from mid-trimester amniotic fluids. IV. Cell type identification via one and two-dimensional electrophoresis of clonal whole cell homogenates

Clones of cultivated amniotic fluid cells that have distinct morphologic and growth characteristics (F, AF and E-type) were examined by one-dimensional SDS polyacrylamide gel electrophoresis (SDS-PAGE) and by two-dimensional electrophoresis employing isoelectric focusing and SDS-PAGE (IEF-PAGE). No qualitative differences in band pattern were observed in SDS-PAGE between the various amniotic fluid cell types, but consistent quantitative differences in the ratios of four bands of presumed filamentous proteins provided good distinction between amniotic fluid cells and postnatal skin fibroblast-like cells. By adding separation on the basis of electrical charge to that of molecular size (IEF-PAGE), we observed reproducible qualitative differences in the protein spot patterns between F and both AF and E-type amniotic fluid cells. At least eight discrete proteins appear not to be synthesized by prenatal F-type cells in comparison with their isogenic AF and E counterparts under identical culture conditions. The two-dimensional electrophoretic patterns thus confirm that F and AF amniotic cells, in spite of their morphologic and growth kinetic similarities, are developmentally distinct cell types that retain their differentiated states in culture.