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Lorraine V. Klerman Dr.P.H. Beth A. Baker M.S. George Howard Dr.P.H. 《The Journal of adolescent health》2003,32(6):452-455
This paper uses survival analysis to examine three large-scale, multi-site, randomized, controlled programs that attempted to prevent or delay second births to teenagers. Statistically significant differences in the hypothesized direction were found between the intervention and the control groups in the Elmira and Memphis Home Visitation sites. No statistically significant differences in the hypothesized direction were found in the Teen Parent Welfare Demonstration overall or in any of its three sites or in all New Chance sites combined. Delaying second pregnancies among teenagers requires intensive efforts. Survival analysis is a more accurate and useful way of presenting program results than simple analysis of the proportion of women with a second birth. 相似文献
3.
长方案、短方案已在临床使用了20余年,这类超排卵方案采用降调节抑制内源性卵泡刺激素(FSH)、黄体生成素(LH)合成和释放,降低了过早排卵导致的周期取消,但也导致了促性腺激素用量大增、促排卵时间延长,即使是卵巢储备正常者也可能出现超排卵反应低下导致周期取消;卵巢储备低下患者则因不能超排而无缘体外受精胚胎移植(IVF-ET);同时,垂体抑制使卵巢反应增加,重度卵巢过度刺激综合征(OHSS)发生率增加.因传统的超排卵技术有上述不足,最近几年关于微刺激或轻刺激的讨论逐渐增多,轻微卵巢刺激的理念已被业界所认可[1-3]. 相似文献
4.
Robin J. Olds David A. Lane Vijoy Chowdhury Geza Sas Ingrid Pabinger Karin Auberger Swee Lay Thein 《Human mutation》1994,4(1):31-41
Two (ATT) trinucleotide repeat polymorphisms have been identified in the tails of Alu repeat elements in intron 5 of the antithrombin gene. The frequency and distribution of allele sizes for the Alu 5 and Alu 8 tail polymorphisms have been defined in a sample Caucasian population. The Alu 5 polymorphism has two alleles while that of Alu 8 has 10 alleles with a heterozygosity of 0.83. These polymorphisms have been used in combination with four previously described polymorphisms within the antithrombin gene to construct antithrombin gene haplotypes in the sample Caucasian population. Twenty-two different haplotypes were observed, with the Alu 8 polymorphism being particularly useful in subdividing the core haplotype based on the previously identified polymorphisms. The haplotype data were used to investigate the origin of repeat mutations within the antithrombin locus. We compared the haplotypes associated the mutant antithrombin genes in five families with the mutation 2759C→T (L99F) and five families with the mutation 5381C→T (R129Stop). The mutation 2759C→T (L99F), which occurs within a non-CpG dinucleotide, was carried on a gene associated with an identical haplotype in each of the five families. The mutation 5381C→T (R129Stop), a single base substitution within a CpG dinucleotide, was associated with at least two different haplotypes. The findings suggest a founder effect in the five families sharing the 2759C→T (L99F) and at least two independent origins for the CpG dinucleotide mutation 5381C→T (Rl29Stop). © 1994 Wiley-Liss, Inc. 相似文献
5.
Objective
This study investigated how health care provider communication of risk information, and women’s role in decision-making, influenced women’s preferences for mode of birth after a previous caesarean birth.Methods
Women (N?=?669) were randomised to one of eight conditions in a 2 (selectivity of risk information) × 2 (format of risk information) × 2 (role in decision making) experimental design. After exposure to a hypothetical decision scenario that varied information communicated by an obstetrician to a pregnant woman with a previous caesarean birth across the three factors, women were asked to decide their preferred hypothetical childbirth preference.Results
Women provided with selective information (incomplete/biased toward repeat caesarean) and relative risk formats (ratio of incidence being compared e.g. 2.5 times higher), perceived lower risk for caesarean and were significantly more likely to prefer repeat caesarean birth than those provided with non-selective information (complete/unbiased) and absolute risk formats (incidence rate e.g. 0.01 per 100). Role in decision-making did not significantly influence childbirth preferencesConclusions
Modifiable aspects of healthcare provider communication may influence women’s decision-making about childbirth preferencesPractice implications
Optimised communication about risks of all options may have an impact on over-use of repeat CS. 相似文献6.
7.
《Hemoglobin》2013,37(3):167-175
Sixty‐seven homozygous male and female thalassemic patients with different phenotypes, aged between 8 and 33 years, were divided into three groups, according to the severity of their β‐thalassemia (thal) mutations. We investigated whether some co‐inherited genetic factors could influence the phenotype. Patients with milder β‐thal defects, homozygotes or compound heterozygotes for the IVS‐I‐6 (T→C) or ?87 (C→G) mutations had a milder disease. In addition, determination of the co‐inheritance of the ?158 (C→T) Gγ polymorphism and the (AT)9T5 repeat motif in the region ?540 to ?525, 5′ to the β‐globin gene, showed that in some patients with severe or mild/severe β‐thal mutations, linked to haplotype III, there was higher Hb F expression. We conclude that in homozygous β‐thal patients, the severity of the mutations is the most important factor influencing the phenotype, but some polymorphisms such as the ?158 (C→T) Gγ and (AT)9T5 repeat motif, increasing the Hb F expression and ameliorate the clinical course of the disease. 相似文献
8.
目的分析医院耐碳青霉烯类鲍氏不动杆菌(CRAB)产金属β-内酰胺酶及菌株间同源性。方法收集医院2012年8-12月临床分离的耐碳青霉烯类鲍氏不动杆菌共51株,用VITEK-2药敏分析系统进行药敏试验,用EDTA纸片协同试验筛查金属酶表型,PCR检测IMP、SIM-1、VIM、NDM-1型金属酶基因;重复序列聚合酶链反应(REP-PCR)方法分析菌株同源性。结果 51株CRAB对多种抗菌药物耐药,EDTA纸片协同试验检测金属酶仅有1株阳性,阳性率1.96%,51株CRAB经PCR检测后仅有1株携带了NDM-1型基因,未检测出IMP、SIM-1、VIM型基因;用REP-PCR法可将51株CRAB分为4个基因型(A-F),其中A型48株,占94.12%,为主要流行株;B、C、D各有1株。结论该院临床分离的CRAB株存在NDM-1型金属酶,REP-PCR法分析CRAB同源性,提示该院CRAB存在水平克隆传播,A型主要流行株。 相似文献
9.
Inken Padberg Sabrina Janßen Thomas F. Meyer 《International journal of medical microbiology : IJMM》2013,303(8):463-474
Epidemiological data exist to support a positive association between Chlamydia trachomatis (Ctr) infection and gynecological cancers; however, putative cellular mechanisms for this association are lacking. Here, we identified Ctr-induced perturbations to host cell phenotypes in vitro that persisted after clearance of infection and could directly contribute to host cell transformation. In particular, human telomerase catalytic subunit (hTERT) mRNA expression and catalytic subunit activity were increased in acute infected late passage IMR90E1A cells. hTERT upregulation was accompanied by recruitment of ceramide, a known regulator of hTERT, to the chlamydial inclusion and was abrogated following doxycycline-mediated infection clearance. In cells cleared of Ctr infection, average telomere length was slightly increased and immunofluorescence staining of the DNA damage marker γH2A.X was reduced after clearance of infection compared with cells that had not been infected. Reduced p53 binding to the promoter of the cell cycle checkpoint regulator p21 was also detected in cells cleared of infection and p21 levels were reduced; moreover, this cell population exhibited increased resistance to etoposide-induced DNA damage. Thus, Ctr infection altered cell aging and survival pathways, which persisted after infection clearance. Cells that survive infection are likely to exhibit altered physiology, as evidenced by an increased resistance to DNA damage-induced apoptosis, which may support cellular transformation. 相似文献
10.
Bardiya ZangbarViraj Pandit M.D. Peter RheeMazhar Khalil M.D. Narong KulvatunyouTerence O'Keeffe M.B. Ch.B. Andrew TangLynn Gries M.D. Donald J. GreenRandall S. Friese M.D. Bellal Joseph 《American journal of surgery》2015,209(6):921-926