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91.
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Horst Steiner MD Dietmar Spitzer Peter H. Weiss-Wichert Anton H. Graf Alf Staudach 《黑龙江环境通报》1995,15(4):373-377
A lethal form of bone dysplasia, platylospondylic lethal chondrodysplasia, was diagnosed prenatally using three-dimensional ultrasound. The various types of three-dimensional imaging mode provided diagnostic details not available by conventional two-dimensional ultrasound. The diagnosis was made after referral in the 23rd week of gestation, allowing termination of pregnancy due to the poor prognosis. Prenatal sonograms were compared with postnatal radiographs. 相似文献
94.
Seher Basaran Peter Miny Ivar-Harry Pawlowitzki Jürgen Horst Wolfgang Holzgreve 《黑龙江环境通报》1988,8(4):315-320
Direct chromosome preparations were performed on placental villi obtained by ultrasoundguided needle aspiration between 18 and 37 weeks of pregnancy in 53 patients. The sampling yielded a sufficient amount of tissue with a maximum of two, and in most cases one, insertions. Placental biopsy is easily performed in cases of severe oligohydrammnios, where fetal blood sampling is usually more difficult. Direct karyotyping of placental villi is faster than chromosome analysis from fetal blood or application of the pipette method on amniotic fluid cells, and currently represents the most rapid approach to prenatal diagnosis of chromosomal abnormalities from the first to the third trimester of pregnancy. 相似文献
95.
A 37-year-old gravida was referred for CVS because of advanced maternal age. A trisomy 21 was present in all cells after short-term incubation (direct processing (DP)) and long-term culture. According to our policy, a retap was offered for confirmation of the result during the legally required 3-day waiting period between communication of the result and termination of pregnancy. Unexpectedly all cells after DP showed a normal male chromosome complement. Further investigations revealed mosaicism in trophoblast tissue and a normal karyotype in amniotic fluid cells and fetal blood (50 mitoses each). The parents elected to continue the pregnancy after extensive ultrasound examinations did not show suspicious findings. After the birth of a healthy child, cell cultures from ten different placental sites confirmed mosaicism. Four out of 100 mitoses from a lymphocyte culture showed an additional chromosome 21. The child had no dysmorphic features and the development was normal at the age of 10 weeks. This case demonstrates the restricted validity of prenatal cytogenetic analysis in the presence of true fetal mosaicism. It also stresses the benefit of our policy to offer a retap in cases with abnormal cytogenetic results prior to termination of pregnancy which is considered unnecessary by many cytogeneticists. 相似文献
96.
Martin Eiden Ariel Vina-Rodriguez Josephine Schlosser Horst Schirrmeier Martin H. Groschup 《Food and environmental virology》2016,8(1):105-107
We detected Hepatitis E virus in serum samples of wild rabbits that were hunted in 1989 around the city of Greifswald, Germany. The recovery of one partial sequence and subsequent phylogenetic analysis indicates a close relationship to rabbit HEV sequences from France and suggests a long-established circulation of rabbit HEV in Europe. 相似文献
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Trees growing in rocks without soil are uncommon. In two arid regions in Baja California, Mexico, field surveys found large numbers of rock-colonizing elephant trees (Pachycormus discolor (Benth.) Coville ex Standl. (Mexican name: copalquin) growing in igneous rocks (granite and basalt) as primary colonizers without the benefit of soil or with a very small amount of soil generated by their own growth. Many adult trees broke large granite boulders and were capable of wedging, growing in, and colonizing rocks and cliffs made of ancient lava flows. This is the first record of a tree species, apart from the previously recorded cacti, capable of primary colonization of rocks and rock rubble in hot deserts. 相似文献
100.
The Effects of Long-Term Grazing Exclosures on Range Plants in the Central Anatolian Region of Turkey 总被引:1,自引:0,他引:1
Over the last fifty years, almost half of the steppe rangeland in the Central Anatolian Region of Turkey (CAR) has been converted
to cropland without an equivalent reduction in grazing animals. This shift has led to heavy grazing pressure on rangeland
vegetation. A study was initiated in June 2003 using 6 multiscale Modified-Whittaker plots to determine differences in plant
composition between areas that have not been grazed in 27 years with neighboring grazed plant communities. A total of 113
plant species were identified in the study area with the ungrazed plots containing 32 plants more than the grazed plots. The
major species were Astragalus acicularis, Bromus tomentellus, Festuca valesiaca, Genista albida, Globularia orientalis, Poa bulbosa, and Thymus spyleus ssp rosulans. Grazing impacts on forbs were more pronounced than for grasses and shrubs. Based on Jaccard’s index, there was only a 37%
similarity of plant species between the two treatments. Our study led to four generalizations about the current grazing regime
and long-term exclosures in the steppe rangeland around the study area: (1) exclosures will increase species richness, (2)
heavy grazing may have removed some plant species, (3) complete protection from grazing for a prolonged period of time after
a long history of grazing disturbance may not lead to an increase in desirable plant species with a concomitant improvement
in range condition, and (4) research needs to be conducted to determine how these rangelands can be improved. 相似文献