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We investigated the regulation of the rat neuron-specific enolase gene using a transient transfection approach. Recent transgenic
mouse studies have shown that a 1.8-kb segment of the ratNSE gene 5′ flanking region, including the first (noncoding) exon but not the first intron, is able to drive expression of a
reporter gene in parallel with endogenousNSE. These data suggest thatcis-acting elements responsible for the spatial and temporal pattern ofNSE gene expression are located within the proximal 1.8 kb of the 5′ flanking sequence. To further investigate this region, we
joined the 1.8-kb regulatory cassette to thecat reporter gene and generated a number of constructs in which the flanking sequence was progressively deleted from the 5′ end.
These constructs were tested by transient transfection into neuronal and nonneuronal cells, followed by an assay for CAT activity.
We found that as little as 255 bp of 5′ flanking sequence was able to confer cell type-specificity on the reporter gene. Further
truncation to 120 bp of 5′ sequence resulted in a sharp downregulation of reporter activity in PC12 cells but a significant
rise in both Neuro-2A neuroblastoma cells and nonneuronal Ltk- cells, indicating thatcis-acting elements controlling the regulation ofNSE in Ltk-, Neuro-2A, and PC12 cells may lie within the 135 bp region covered by this deletion. This region contains an AP-2
site and an element similar in sequence and position to a motif identified in the proximal promoter region of the neuron-specific
peripherin gene. Reduction to 95 bp of 5′ sequence resulted in a slight downregulation of CAT activity in all cell lines tested,
and further truncation to 65 bp of 5′ sequence caused a universal reduction to background levels of CAT activity, concomitant
with the disruption of the basalNSE promoter. Our results show that the 5′ flanking region of theNSE gene is capable of conferring cell type-specificity on a heterologous gene in transfected cells and that elements responsible
for this are located within the proximal 255 bp. 相似文献
74.
Summary: A case of 4 true knots in an umbilical cord, which did not cause any detectable harm, is presented. Careful examination of the placenta, membranes and umbilical cord continues to be encouraged. 相似文献
75.
Gideon Fait MD Dan Grisaru MD Michael Shenhav MD Michael J. Kupfermine MD Joseph B. Lessing MD M. Reuben Peyser MD Ariel Jaffa MD 《The Australian & New Zealand journal of obstetrics & gynaecology》1997,37(2):174-176
Summary: One hundred five women with a documented pregnancy of 41 weeks' gestation or more, admitted for induction of labour by balloon catheter with extra-amniotic saline instillation, were retrospectively compared to 196 women admitted in spontaneous labour at the same gestational age, with regard to mode of delivery. The success rate of the induction group was 97.1%. The mode of delivery did not differ significantly between the 2 groups. The Caesarean section rates were 11.4% in the induction group versus 9.7% in the spontaneous group. The mode of delivery after induction of labour by balloon catheter with extra-amniotic saline instillation and simultaneously commenced intravenous oxytocin infusion, in pregnancies of 41 weeks or more, is similar to that of spontaneous deliveries at the same gestational age. 相似文献
76.
Dan Theodorescu 《The Journal of urology》1996,155(5):1661-1662
77.
We describe a simple, quick ultrasound screening test for CDH, and its use in a prospective study of babies with a 'high risk' factor, over one year from January 1987. From a birth population of 3,879, 812 hip scans were performed on 406 babies and 98 babies were abnormal. So far, there have been no late cases of CDH. Family history, breech malposition, and postural foot deformities were confirmed to be important risk factors, but babies with a simple click were equally at risk. Our early results indicate that a large proportion of the potential late cases are contained within our extended high-risk group. 相似文献
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