Pregnancy outcomes of day-2 versus day-3 embryo transfer in poor responders / 中华男科学杂志

<p><b>OBJECTIVE</b>To investigate whether the day of embryo transfer (day 2 or day 3) affects clinical pregnancy outcomes in poor responder patients.</p><p><b>METHODS</b>We retrospectively analyzed the pregnancy rates of 265 initial fresh cycles of in vitro fertilization-embryo transfer (IVF-ET), all transferred on day 2 (n = 169) or day 3 (n = 96) irrespective of quality because of an extremely low number of available embryos.</p><p><b>RESULTS</b>Among the poor responders aged < 35 years, a higher rate of clinical pregnancy was achieved in the day-3 than in the day-2 group (50% vs 32.43% ; RR = 0.65, 95% CI: 0.43 - 0.99), and among those aged years, the two groups showed similar pregnancy outcomes.</p><p><b>CONCLUSION</b>Shortening the time of embryo culture has no obvious benefit for the pregnancy outcome. For the poor responders under 35 years of age, day-3 embryo transfer may afford an even higher rate of clinical pregnancy.</p>

Hypoxia induces heat shock protein HSP70-2 expression in a HIF-1 dependent manner / 中华肝脏病杂志

<p><b>OBJECTIVES</b>To investigate role of hypoxia inducible factor 1 (HIF-1) in the transcriptional activation of heat shock protein 70-2 (HSP70-2) in hepatocellular carcinoma (HCC) cells under hypoxic conditions.</p><p><b>METHODS</b>HCC cells were exposed to reduced oxygen atmosphere (1% O2), or treated with YC-1 or HIF-1 alpha siRNA, the expression of HIF-1 alpha and HSP70-2 were detected by Western blot analysis. Serial deletions of the HSPA2 promoter were cloned in the reporter pGL3-Basic plasmid. These reporter plasmids were co-transfected with HIF-1 alpha siRNA, and the promoter activities were detected with the dual luciferase assay.</p><p><b>RESULTS</b>Western blot analysis showed that both HIF-1 alpha and HSP70-2 proteins were strongly increased after HCC cells were exposed to hypoxic conditions (1% O2) for 6 h, and the expression level of HSP70-2 was increased in a time-dependent manner. Treatment of HepG2 cells with YC-1 or HIF-1 alpha siRNA significantly inhibited the expression of HIF-1 alpha and HSP70-2. In silico analysis of the HSP70-2 promoter using the Gene2 Promoter software revealed the presence of two putative hypoxic response element (HRE) consensus at -446bp (HRE1) and -238bp (HRE2). Depletion of promoter sequence between -653 and -385 led to a dramatic reduction of promoter activity, whereas further deletion to position -201 did not reduce the activity further. These data suggested that HRE1 plays an important role in hypoxia-induced activation of the HSPA2 promoter. Site-directed mutagenesis further confirmed these results. Mutation of HRE1 but not of HRE2 abrogated the sensitivity of the HSP70-2 promoter to hypoxia.</p><p><b>CONCLUSIONS</b>HSP70-2 expression is up-regulated in response to hypoxia and a HIF-1 binding site (HRE1) in the HSP70-2 promoter is involved in this response.</p>