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51.
OBJECTIVE: Because survival from admission to discharge does not provide parents and physicians information about future life expectancy in the premature neonate, we characterized the actuarial survival, defined as the future life expectancy from a given postnatal age, in a large inborn population of premature infants < 30 weeks' gestation. STUDY DESIGN: We determined daily actuarial survival of 1925 inborn infants (23 to 29 weeks' gestation) admitted to the Baylor Affiliated Nurseries from July 1986 through December 1994, stratified by 100-g birth weight and by 1-week gestational-age intervals. RESULTS: In the 501- to 600-g birth weight stratum, actuarial survival improved from 31% at birth, to 61% on day of life 7, and then to 75% on day of life 28; in the 901- to 1000-g birth weight stratum, actuarial survival improved from 88%, to 94%, and then to 98% throughout the same times, respectively. Similar trends were obtained when data were stratified by gestational age. CONCLUSIONS: Survival in the smallest infants improves dramatically during the first few days of life, but there is a significant risk for late death in the smallest of these infants. 相似文献
52.
Antisense RNA-mediated reduction of p53 induces malignant phenotype in nontumorigenic rat urothelial cells 总被引:2,自引:1,他引:2
p53 mutation is commonly associated with high-grade, high-stage human
urothelial carcinomas. Recent studies suggest that p53 mutation in low-
grade, low-stage bladder carcinomas may be correlated with the progression
of the disease. In the present study, we used antisense RNA methodology in
vitro to evaluate the significance of the loss of p53 function at an early
stage of urinary bladder carcinogenesis. An immortalized nontumorigenic rat
urothelial cell line (MYP3) that strongly expresses wild-type (WT) p53 was
transfected with a plasmid (pcDL-SR alpha-296) containing a rat WT p53 cDNA
in antisense orientation. The transfection resulted in a significant
reduction in p53 mRNA expression and protein synthesis, in stimulation of
anchorage- dependent growth, and in acquisition of anchorage-independent
growth potential. Three such clones, when tested in athymic nude mice, all
formed muscle-invasive, high-grade transitional cell carcinomas at s.c.
injection sites. When cells were inoculated into an orthotopic site
(urinary bladder), one of two antisense transfectants tested formed bulky
tumors in the bladder in all seven nude mice and metastases to lungs in
three of the seven mice. Analysis of these cells revealed a decrease in the
expression of p21 (WAF1, sdi1, or CIP1) and retinoblastoma (Rb) gene
product. Phosphorylation of Rb protein was not inhibited when the cells
were starved. No significant difference was observed in the expression of
p16 protein. In cell cycle analysis, all antisense transfectants tested
escaped from G1 arrest by starvation. Furthermore, secretion of interleukin
(IL)-6 into culture medium was increased significantly. Treatment with
anti-IL-6 antibody suppressed anchorage-dependent growth. This study
directly demonstrates that the loss of p53 function at an early stage of
urothelial carcinogenesis may result in acquisition of a malignant
phenotype by regulating IL-6 production as well as cell cycle related
genes.
相似文献
53.
Interaction of the C-terminal tail region of the metabotropic glutamate receptor 7 with the protein kinase C substrate PICK1 总被引:5,自引:0,他引:5
El Far O Airas J Wischmeyer E Nehring RB Karschin A Betz H 《The European journal of neuroscience》2000,12(12):4215-4221
Group III metabotropic glutamate receptors (mGluRs) are highly enriched in the presynaptic terminals of glutamatergic synapses where they mediate feedback inhibition of neurotransmitter release. Here, we used the yeast two-hybrid system to identify a direct interaction of the C-terminal tail region of mGluR7 with the rat homologue of the protein kinase C substrate PICK1. This interaction is specifically mediated by the very C-terminal amino acids of the receptor and can be reconstituted in human embryonic kidney 293 cells by transfection of full-length mGluR7 and PICK1 cDNAs. Quantitative beta-galactosidase assays revealed that among the different group III mGluRs, mGluR7 is the major PICK1 binding partner although other subfamily members can also interact with PICK1. These data indicate that PDZ domain-containing proteins might contribute to the presynaptic localization of group III mGluRs. 相似文献
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A survey of southern California hospitals identified current visitation policies and the rationale for the restrictions of siblings and peers. Questionnaires mailed to the nursing administrators of 212 hospitals having designated pediatric beds indicated that the majority allowed some form of sibling visitation. The rationales for restriction most frequently given were prevention of infection and spread of communicable disease. The results indicate a gap between sibling visitation research and the theoretical rationale given to support restrictive policies. 相似文献
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