Yi-min Shu

Sun Yat-Sen University, Shengcheng, Guangdong, China

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Publications (10)12.6 Total impact

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    ABSTRACT: In an attempt to allow for acquisition of oocyte cytoplasmic maturation, PDE3 specific inhibitor, cilostamide and adenylate cyclase activator, forskolin were used to extend pre-maturation culture of immature human oocytes. Cumulus-oocyte complexes retrieved from unstimulated ovaries were continuously cultured under 20 microM cilostamide or 50 microM forskolin, alone or in combination for 6, 12, 24 or 48 h, respectively. Levels of intercellular gap junction communication (GJC) and maturational status were examined at these designated time points. Metaphase II oocytes obtained following 54 h biphasic culture (with meiotic inhibitors from 0 to 24 h, no meiotic inhibitors from 24 to 54 h) were subject to intracytoplasmic sperm injection and embryos were cultured for five more days. Both cilostamide and forskolin delayed spontaneous meiotic progression after continuous culture with immature human oocytes. Combined treatment of cilostamide and forskolin significantly lowered the rates of germinal vesicle breakdown (GVBD) at 6, 12, 24 or 48 h after meiotic inhibitory culture, when compared with the control (all P < 0.05). A delay of 6 h for the loss of GJC was also observed under the combined treatment of cilostamide and forskolin. The fertilization rate was significantly higher under the combined treatment of cilostamide and forskolin than that of the control. Although the rates of oocyte maturation and embryo cleavage were similar among groups, there was a slight but non-significant increase in blastocyst formation rate with the treatment of cilostamide and forskolin. Combined treatment of cilostamide and forskolin positively influences oocyte developmental competence by exhibiting a synergistic effect on the prevention of GJC loss and resumption of meiosis.
    Human Reproduction 04/2008; 23(3):504-13. · 4.67 Impact Factor
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    ABSTRACT: To investigate the apoptosis-inducing effect of oridonin, a diterpenoid isolated from Rabdosia rubescens, in the human cervical carcinoma HeLa cell line. A morphological analysis, nuclear condensation, and fragmentation of chromatin were monitored using Hoechst 33342 staining. Cell viability was assessed using the 3-(4, 5-dimethylthiazol-(2)-yl)-2, 5-diphenyl tetrazolium bromide (MTT) assay. Cell apoptosis and the apoptosis-related activation in the HeLa cell line were evaluated by flow cytometry and Western blotting. Oridonin suppressed the proliferation of the HeLa cell line in a dose- and time-dependent fashion. Oridonin treatment downregulated the activation of protein kinase B (Akt), the expression of forkhead box class O (FOXO) transcription factor, and glycogen synthase kinase 3 (GSK3). Oridonin also induced the release of cytochrome c accompanied by the activation of caspase-3 and poly-adenosine diphosphate- ribose polymerase cleavage. In addition, Z-D(OMe)-E(OMe)-V-D(OMe)- FMK (z-DEVD-fmk), an inhibitor of caspases, prevented caspase-3 activation and abrogated oridonin-induced cell death. Finally, oridonin treatment of the HeLa cell line downregulated the expression of the inhibitor of the apoptosis protein. Our results showed that oridonin-induced apoptosis involved several molecular pathways. Oridonin may suppress constitutively activated targets of phosphatidylinositol 3-kinase (Akt, FOXO, and GSK3) in the HeLa cell line, inhibiting the proliferation and induction of caspase-dependent apoptosis.
    Acta Pharmacologica Sinica 12/2007; 28(11):1819-26. · 2.35 Impact Factor
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    ABSTRACT: Birefrigent meiotic spindle in live human oocytes can be visualized by the PolScope. This study investigated the relationship between birefrigent meiotic spindle and cytoplasmic mitochondrial DNA (mtDNA) and ATP contents in in vitro matured human oocytes. Oocytes at germinal vesicle stage were collected and cultured for 24-48 h with or without the metabolic inhibitor, carbonyl cyanide p-(tri-fluromethoxy) phenyl-hydrazone (FCCP). All in vitro matured oocytes were examined by PolScope for the presence of meiotic spindle, then the oocytes were used for either intracytoplasmic sperm injection or the measurement of mitochondrial quantity and ATP content. Meiotic spindles were observed in 51.3% (60/117) of the in vitro matured oocytes. Oocytes with detectable meiotic spindle contained significantly higher mtDNA copies (637 250 +/- 237 606 versus 491 454 +/- 153 406, P = 0.027) and ATP content (1.97 +/- 0.38 versus 1.65 +/- 0.32 pmol, P = 0.028) when compared with those without detectable meiotic spindle. However, in vitro matured oocytes showed a significantly reduced rate of positive meiotic spindle and a lower ATP content when cultured with FCCP. A lower incidence of normal fertilization and good quality embryos were observed if meiotic spindles were not detected. Low mtDNA and ATP content might contribute to the absence of birefringent spindle imaged with the PolScope in human in vitro matured oocytes.
    Human Reproduction 07/2007; 22(6):1681-6. · 4.67 Impact Factor
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    ABSTRACT: Clinical programs for preventing beta-thalassemia are presently based on prospective carrier screening and prenatal diagnosis. This paper report an achievement of a pregnancy with unaffected embryos using in vitro fertilization and embryo transfer (IVF-ET), in combination with preimplantation genetic diagnosis (PGD), for a couple at risk of having children with beta-thalassemia. A couple carrying different thalassemia mutations, both a codon 41 - 42 mutation and the IVS II 654 mutation, received standard IVF treatment, with intracytoplasmic sperm injection, embryo biopsiy, single cell polymerase chain reaction (PCR) and DNA analysis. Only unaffected or carrier embryos were transferred to the uterine cavity. After confirmation of pregnancy, a prenatal diagnosis was performed. Of a total of 13 embryos analyzed for beta-globin mutations, PGD indicated that 2 were normal, 3 were affected, and 6 were carriers. Diagnosis could not be made in the other 2 embryos. Three embryos were transferred to the uterus on the third day after oocyte retrieval. Ultrasonography revealed a twin pregnancy with one blighted ovum. The prenatal genetic diagnosis revealed that both fetuses were unaffected, and two healthy boys were born, confirming the results of PGD. We developed a single-cell based primer extension preamplification (PEP)-PCR assay for the detection of beta-thalassemia mutations. The assays were efficient and accurate at all stages of the procedure, and resulted in the birth of PGD-confirmed beta-thalassemia free children in China. PEP was used here in PGD for beta-thalassemia.
    Chinese medical journal 05/2004; 117(4):483-7. · 0.90 Impact Factor
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    ABSTRACT: To review the outcome of repeated percutaneous sperm aspiration (PESA) and testicular sperm extraction (TESE) for intracytoplasmic sperm injection (ICSI). Forty-three cycles of 31 cases of azoospermic patients which underwent at least two PESA or TESE for ICSI from January 2001 to December 2002 were collected. The sperm retrieval, fertilization, implantation and clinical pregnancy were analyzed. Twenty-four cases underwent PESA and 7 cases underwent TESE. There were not any complications in these patients. Compared with the first cycle of 154 cases, the fertilization rate, implantation rate and clinical pregnancy rate were 78.39% vs 73.64%, 19.68% vs 18.38% and 34.88% vs 37.91%, respectively(P > 0.05). Repeated PESA or TESE is safe and well tolerated in azoospermic patients. Compared with the first cycle, the differences of repeated PESA or TESE cycles in fertilization rate, implantation rate and clinical pregnancy rate were not statistically significant.
    Zhonghua nan ke xue = National journal of andrology 11/2003; 9(7):524-6.
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    ABSTRACT: To achieve pregnancy with unaffected embryo using in vitro fertilization and embryo transfer (IVF-ET) and preimplantation genetic diagnosis(PGD) for the couples at risk of having children with beta-thalassemia. A couple carrying different thalassemia mutations of codon 41/42 and codon IVS2 position 654 received standard IVF treatment and intracytoplasmic sperm injection, embryo biopsy, single cell polymerase chain reaction and DNA analyses, and only the unaffected or carrier embryos were transferred to uterus. Pregnancy confirmation, and prenatal diagnosis were done at 20 week's gestation. A total of 13 embryos were analyzed in the IVF cycle. PGD indicated that 2 were normal 18.1 , 3 were affected 27.3 , and 6 were carriers 54.5 ; diagnosis was not possible in 2. Three embryos were transferred to uterus on the third day after oocyte retrieval. Ultrasonography showed twin pregnancy with one blighted ovum. The prenatal diagnoses revealed that both fetuses were unaffected, one normal baby and one carrier were born. These studies represent the successful application of PGD for beta-thalassemia in China.
    Zhonghua yi xue yi chuan xue za zhi = Zhonghua yixue yichuanxue zazhi = Chinese journal of medical genetics 11/2003; 20(5):447-8.
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    ABSTRACT: To assess the clinical value of pronuclear stage scoring system in human conventional in vitro fertilization-embryo transfer (IVF-ET) program. A modified pronuclear scoring system was used to score zygotes 16 - 18 hours after insemination during conventional IVF. A total of 178 IVF cycles were recruited in this study. Cycles with mean pronuclear score (sum of pronuclear scores of all transferred embryos divided by total number of transferred embryos) > or = 13 had significant high pregnancy and implantation rate, as compared to those with less than 13 (49.1% and 26.5% Vs 29.4% and 15.0% respectively). Although the pregnancy, implantation rate and multiple pregnancy rate tend to increase with the increasing number of zygotes with full pronuclear score (= 15) among transferred embryos, no significant difference could be found (P > 0.05). When all embryos were analyzed, 77.2% zygotes with pronuclear score > or = 11 could be transferred or cryopreserved, while those with pronuclear score less than 11 decreased to 46.1%. Pronuclear stage scoring system provides additional parameter for embryo selection. However, pronuclear morphology could only partly represent embryonic viability. Combination with the scoring of both pronuclear stage and cleavage stage embryos for selecting transferred embryos is indispensable.
    Zhonghua fu chan ke za zhi 06/2003; 38(6):343-5.
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    ABSTRACT: To achieve preimplantation genetic diagnosis (PGD) of the couples at risk of having children with beta-thalassemia, as an alternative to prenatal diagnosis. Two couples carrying different thalassemia mutations of codon 41/42 and codon intervening sequence 2 position 654 received standard in vitro fertilization treatment and intracytoplasmic sperm injection, embryo biopsy and the whole genome was amplified by primer extension preamplification (PEP). Nested polymerase chain reaction was then used to amplify two mutation sites separately. Both were detected by reverse dot-blot. A total of 35 oocytes were retrieved from the two patients. Among them, 87% showed two pronuclei, and embryo biopsy was performed on 16 of these embryos and 25 blastomeres were obtained. The amplification efficacy was 84%. The genotype study of non-transferred and surplus embryos showed 15% of allele drop-out rate. Five embryos were transferred to the uterus of both patients. One pregnancy achieved, resulted in live healthy twin births, which confirmed the results of PGD. This unaffected pregnancy resulting from PGD by PEP for beta-thalassemia demonstrates that this technique can be a effective diagnostic tool for carrier couples who desire a healthy child.
    Zhonghua fu chan ke za zhi 04/2003; 38(3):143-6.
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    ABSTRACT: To investigate the effect of in vitro fertilization and embryo transfer (IVF-ET) and preimplantation genetic diagnosis (PGD) for the couples at risk of having children with beta-thalassemia. Four couples carrying different thalassemia mutations received standard IVF treatment. Embryo biopsy was conducted. Single blastomeres were genotyped by a protocol involving primer extension preamplification, nested polymerase chain reaction and reverse dot-blot analysis. Only the unaffected embryos were transferred to the uterus. A total of 97 oocytes were retrieved from the four female carriers. Among them, 83% showed two pronuclei. Embryo biopsy was performed on 47 of these embryos. The amplification efficiency was 84.8%. The average ADO rate was 14.9%. Ten unaffected embryos were transferred. A twin pregnancy with one blighted ovum was confirmed at 7 weeks' gestation by ultrasonography and one normal baby and one carrier of thalassemia mutation were born finally. This unaffected pregnancy resulting from PGD for beta-thalassemia demonstrates that PGD technique can be a powerful diagnostic tool for couples carrying beta-thalassemia mutations who desire a healthy child and wish to avoid abortion of an affected fetus.
    Zhonghua yi xue za zhi 03/2003; 83(4):298-301.
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    ABSTRACT: To review the retrospective treatment results of the azoospermia patients during January 2001 to January 2002 in the fertility center. One hundred males attempted intracytoplasmic sperm injection (ICSI) cycle for treatment of azoospermia. All patients were undergone sperm retrieval by percutaneous epididymal sperm aspiration (PESA) or testicular sperm extraction (TESE) while their wives received conventional ovarian hyperstimulation. The hormone levels, testicular histology, the rates of sperm retrieval, fertilization, implantation and pregnancy were analysed and evaluated. Sperm were retrieved by PESA in 76 of 100 (76%) and by TESE in 23 of 100 (23%) men of azoospermia. The fertilization rate, implantation rate and clinical pregnancy rate were 71.3%, 20.35% and 42.11% respectively in PESA group, and 75.18%, 22.05% and 41.60% respectively in TESA group. Thirty-two clinical pregnancies were achieved with 15 ongoing pregnancies and subsequent live delivery for 15 cases in PESA group, and 2 cases of miscarriage, while 10 clinical pregnancies were achieved with 6 ongoing pregnancies, 2 cases of live delivery and 2 cases of miscarriage in TESA group. One case failed to retrieve sperm by TESE and canceled. Hormonal levels and testicular histology are unable to predict which men with azoospermia will have sperm retrieved by PESA and TESE. PESA and TESE with ICSI are effective methods to treat azoospermia. There were no significant differences in fertilization, implantation and clinical pregnancy rate between two groups.
    Zhonghua nan ke xue = National journal of andrology 02/2002; 8(4):258-60.

Publication Stats

82 Citations
12.60 Total Impact Points

Institutions

  • 2008
    • Sun Yat-Sen University
      Shengcheng, Guangdong, China
  • 2007
    • Stanford University
      • Department of Obstetrics and Gynecology
      Palo Alto, California, United States