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51.
Stark AR Carlo WA Tyson JE Papile LA Wright LL Shankaran S Donovan EF Oh W Bauer CR Saha S Poole WK Stoll BJ;National Institute of Child Health Human Development Neonatal Research Network 《The New England journal of medicine》2001,344(2):95-101
BACKGROUND: Early administration of high doses of dexamethasone may reduce the risk of chronic lung disease in premature infants but can cause complications. Whether moderate doses would be as effective but safer is not known. METHODS: We randomly assigned 220 infants with a birth weight of 501 to 1000 g who were treated with mechanical ventilation within 12 hours after birth to receive dexamethasone or placebo with either routine ventilatory support or permissive hypercapnia. The dexamethasone was administered within 24 hours after birth at a dose of 0.15 mg per kilogram of body weight per day for three days, followed by a tapering of the dose over a period of seven days. The primary outcome was death or chronic lung disease at 36 weeks' postmenstrual age. RESULTS: The relative risk of death or chronic lung disease in the dexamethasone-treated infants, as compared with those who received placebo, was 0.9 (95 percent confidence interval, 0.8 to 1.1). Since the effect of dexamethasone treatment did not vary according to the ventilatory approach, the two dexamethasone groups and the two placebo groups were combined. The infants in the dexamethasone group were less likely than those in the placebo group to be receiving oxygen supplementation 28 days after birth (P=0.004) or open-label dexamethasone (P=0.01), were more likely to have hypertension (P<0.001), and were more likely to be receiving insulin treatment for hyperglycemia (P=0.02). During the first 14 days, spontaneous gastrointestinal perforation occurred in a larger proportion of infants in the dexamethasone group (13 percent, vs. 4 percent in the placebo group; P=0.02). The dexamethasone-treated infants had a lower weight (P=0.02) and a smaller head circumference (P=0.04) at 36 weeks' postmenstrual age. CONCLUSIONS: In preterm infants, early administration of dexamethasone at a moderate dose has no effect on death or chronic lung disease and is associated with gastrointestinal perforation and decreased growth. 相似文献
52.
Successful outcome with day 4 embryo transfer after preimplantation diagnosis for genetically transmitted diseases 总被引:4,自引:5,他引:4
Preimplantation genetic diagnosis was performed in 61 day 3 embryos
obtained by in-vitro fertilization from seven patient carriers of
haemophilia, Marfan's syndrome, Bloch-Sulzemberg syndrome (incontinentia
pigmentosa) or X chromosome-linked immune deficiency, retinitis pigmentosa,
and FG syndrome, which is characterized by mental retardation and
hypotonia. After multiplex polymerase chain reaction, 16 embryos were
diagnosed as being unaffected, and these were transferred to the uterus on
the following day (day 4). Of these embryos, six (37.5%) implanted,
resulting in the delivery of a singleton and a twin pregnancy, a late
second trimester miscarriage (twins at week 20) and a first trimester
miscarriage at week 8. All the diagnoses were confirmed by amniocentesis.
We report for the first time a late day 4 transfer of biopsied human
embryos undergoing preimplantation genetic diagnosis. This transfer
schedule allows an extra day to perform genetic analyses on single
blastomeres and to monitor any adverse effect of the biopsy procedure.
相似文献
53.
54.
Band MR Larson JH Rebeiz M Green CA Heyen DW Donovan J Windish R Steining C Mahyuddin P Womack JE Lewin HA 《Genome research》2000,10(9):1359-1368
A cattle-human whole-genome comparative map was constructed using parallel radiation hybrid (RH) mapping in conjunction with EST sequencing, database mining for unmapped cattle genes, and a predictive bioinformatics approach (COMPASS) for targeting specific homologous regions. A total of 768 genes were placed on the RH map in addition to 319 microsatellites used as anchor markers. Of these, 638 had human orthologs with mapping data, thus permitting construction of an ordered comparative map. The large number of ordered loci revealed > or =105 conserved segments between the two genomes. The comparative map suggests that 41 translocation events, a minimum of 54 internal rearrangements, and repositioning of all but one centromere can account for the observed organizations of the cattle and human genomes. In addition, the COMPASS in silico mapping tool was shown to be 95% accurate in its ability to predict cattle chromosome location from random sequence data, demonstrating this tool to be valuable for efficient targeting of specific regions for detailed mapping. The comparative map generated will be a cornerstone for elucidating mammalian chromosome phylogeny and the identification of genes of agricultural importance."Ought we, for instance, to begin by discussing each separate species-in virtue of some common element of their nature, and proceed from this as a basis for the consideration of them separately?" from Aristotle, On the Parts of Animals, 350 B.C.E. 相似文献
55.
56.
How to use Chlamydia antibody testing in subfertility patients 总被引:1,自引:9,他引:1
Screening for tubal factor subfertility by means of Chlamydia antibody
testing (CAT) was introduced into the initial work-up of subfertile couples
several years ago. The results reported, however, are heterogeneous, and no
uniformity exists in cut-off levels of titres, or in definitions of tubal
factor subfertility. We performed a prospective cohort study to evaluate
the implications of varying the definitions of tubal pathology and of
modifying the cut-off levels on the clinical impact of CAT in predicting
tubal factor subfertility. In 227 consecutive patients who attended our
fertility clinic, the Chlamydia IgG antibody titre was determined and
related to tuboperitoneal abnormalities at laparoscopy as a reference
standard. According to received operating characteristic (ROC) curve
analysis, a titre of 16 is the optimum cut-off level. Increasing the
cut-off level improves specificity and positive likelihood ratio (LR+), at
the expense of sensitivity and negative LR (LR-). Changing the definition
of tubal factor subfertility from unspecified tuboperitoneal abnormalities
into extensive adhesions and/or bilateral distal tubal occlusion improves
LR+, LR- and kappa significantly. We conclude that CAT is more accurate in
predicting severe distal tubal pathology than unspecified tuboperitoneal
abnormalities. Although from a statistical point of view a titre of 16 is
the optimum cut-off level, from a clinical point of view 32 or 64 may be
preferable, depending on the aim of screening and the inception cohort.
相似文献
57.
Anxiety during pregnancy and fetal attachment after in-vitro fertilization conception 总被引:3,自引:4,他引:3
McMahon CA; Ungerer JA; Beaurepaire J; Tennant C; Saunders D 《Human reproduction (Oxford, England)》1997,12(1):176-182
The aim of this study was to compare 70 couples who had conceived by in-
vitro fertilization (IVF) with 63 matched controls for the prevalence of
anxiety and quality of attachment to the baby during pregnancy. Results for
mothers showed no group differences using a global measure of anxiety, the
Spielberger State-Trait Anxiety Inventory. However, pregnancy-specific
measures revealed significantly higher levels of anxiety in IVF mothers
about the survival and normality of their unborn babies, about damage to
their babies during childbirth and about separating from their babies after
birth. When IVF mothers were differentiated according to the number of
treatment cycles, more differences in anxiety level were revealed, with
most increases occurring in mothers who had experienced two or more
treatment cycles. IVF fathers did not differ from controls on the global
anxiety measure. No data on pregnancy-specific anxiety were available for
fathers. Neither IVF mothers nor IVF fathers differed from controls on
measures of attachment to the baby during pregnancy. Results are discussed
in the context of the need for researchers to employ differentiated and
issue-specific measures to identify concerns that may be unique to IVF
couples. Clinical implications regarding the need for psychological support
during pregnancy are also discussed.
相似文献
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