P–205 Epothilone D as an actin cytoskeleton stabilizer improved mitochondria bioenergenesis and blastocyst formation of mouse preimplantation embryo

Study question

What is primary factor of bioenergetics product activity between microtubule instability and the functional activity of mitochondria in embryo?

Summary answer

The actin cytoskeleton instability is presumably the primary cause for the bioenergenesis of mitochondrial function to the preimplantation embryo development.

What is known already

Mitochondria are cellular organelles dynamically moving and morphological changes. It provides for homeostatic energy to the cell. The dynamic property of the mitochondria is associated with the microtubule network in the cell. However, the stability of the microtubule was clearly identified for preimplantation embryo development.

Study design, size, duration

This study is designed to assess the ATP productivity of the mitochondria, and specifically to observe what its primary factor is in terms of providing microtubule stability in mammalian cells. Additionally, we investigated the relationship between blastocyst formation and actin cytoskeleton stabilization by EpD with 2-cell mice.

Participants/materials, setting, methods

We prepared the microtubule stability regulation model with the HEK293 cell line by using the microtubule stabilizer as an Epothilone D (EpD). Then we analyzed the metabolic activity of the cells through oxidative phosphorylation (OXP) ratios analysis. Also, we performed confocal live imaging to observe mitochondria morphology depending on the cells’ microtubule. Next, we treated EpD to 2-cell culture media for the analysis of blastocyst development ratios.

Main results and the role of chance

EpD significantly increased fusion form. Also, EpD enhance bioenergy ratios like OXP in the mitochondria and functional activity related marker, like mTOR compared with the control. These results suggest that microtubule stabilization enhances mitochondrial metabolism by increasing oxygen consumption. Also, EpD in 2-cell culture media led to a significant increase in the speed of development and 50% higher hatched out blastocyst formation ratios compared to the control group.

Limitations, reasons for caution

This study had limited animal experiments. For the next study, we are planning with an aim to improve the quality and development ratios of human embryos by EpD.

Wider implications of the findings: Microtubule stabilizer has a possibility to recover the mitochondria’s functional activity in the preimplantation embryo development. Mitochondrial functional activity along the actin cytoskeleton may play a pivotal role in determining the embryo quality and development ratios for archive pregnancy.

Trial registration number

non-clinical trials

P–657 Prostaglandin D2 is correlated with follicles development and a reliable marker of ovarian reserve of poor ovarian responder patients

Study question

Is the prostaglandin D2 (PGD2) associated with growing follicles and ovarian reserve of poor ovarian responders?

Summary answer

PGD2 is correlated with ovarian stimulation activity and follicle growth. Especially, poor ovarian responders show a significant decrease in the level of follicular fluid.

What is known already

Prostaglandins (PGs) are involved in the female reproductive process, mainly ovulation, fertilization, and implantation.

Study design, size, duration

We investigated the PGD2 level in the follicular fluid of poor ovarian responders. The collection of human follicular fluid was approved by the Institutional Research and Ethical Committees of CHA University (approval number: 1044308–201611-BR–027–04) from January to December 2019. Follicular fluid was collected from patients with normal ovarian response and patients with POR.

Participants/materials, setting, methods

We studied whether prostaglandin has related to POR in the clinical key factor by measuring human follicular fluid. Follicular fluid was collected from patients with normal ovarian response and patients with POR. The concentration of PGD2 in follicular fluid was determined with ELISA kits following the manufacturer’s protocol.

Main results and the role of chance

We analyzed the level of PGD2 in the follicular fluid of patients with normal ovarian response and patients with POR using an ELISA. The PGD2 concentration was significantly lower in the follicular fluid of patients with POR than in the follicular fluid of young and old patients with normal ovarian response.

Limitations, reasons for caution

This study has an identification of biomarker of the clinical samples as POR criteria patients. Therefore, further investigations aimed at specific recovery of low PGD2 metabolic activity in the CCs during control ovarian stimulation.

Wider implications of the findings: Until now there is no specific biomarker of POR. AMH is just an ovary reserve marker for an indication of ovary function. PGD2 is one of the metabolites in steroid metabolism in the ovary. Therefore, we can find some cure through further study for improved PGD2 production to POR patients.

Trial registration number

none

P–658 Lovastatin promotes the expression of LDL receptor and enhances E2 production in the cumulus cells

Study question

Lovastatin enhanced E2 productive ratios in the cumulus cells through promoted expression of Low-density lipoprotein receptor (LDLR).

Summary answer

Lovastatin up-regulated gene expression of LDLR in the CCs. And the high expression of LDLR promoted E2 productive ratios from CCs.

What is known already

We already reported that the up-regulation of LDLR correlated with clinical pregnancy. Therefore, we found lovastatin as an up-regulator of LDLR expression of clinical pregnancy.

Study design, size, duration

This is an expended study of LDLR to enhance steroidogenesis regarding the effect of lovastatin in the CCs. The collection of human cumulus cells was approved by the Institutional Research and Ethical Committees of CHA University (approval number: 1044308–201611-BR–027–04) from January to December 2019. The CCs were collected from 12 patients with normal ovarian response after oocyte denudation for ICSI.

Participants/materials, setting, methods

We studied whether lovastatin has up-regulated LDLR expression in human CCs. Cumulus cells were collected from patients with young (∼ 36) and old aged patients (37 ∼). After culturing human CCs, they were treated lovastatin for one day. The concentration of E2 in culture medium was measured using Chemiluminescence immunoassay. The mRNA isolated from CCs was analyzed gene expression level through real time-PCR.

Main results and the role of chance

The concentration of E2 was significantly increased in the culture medium treated with lovastatin. The CCs treated with lovastatin increased the expression of LDLR and StAR which are components of the steroidogenesis pathway.

Limitations, reasons for caution

We have found that the role of lovastatin promotes the E2 production by increasing the ldlr gene of CCs. Therefore, further investigations aimed at lovastatin effect on human oocytes embryo whether enhanced quality of oocytes or not.

Wider implications of the findings: Previous data show that high activation of LDLR and StAR was associated with embryo quality and clinical pregnancy in infertile women. Our data suggest that lovastatin is stimulated LDLR expression to enhanced pregnancy ratios of IVF patients.

Trial registration number

none

Reasons for lack of referral to medical oncology for systemic therapy in stage IV non-small-cell lung cancer: comparison of 2003-2006 with 2010-2011

Introduction

Only approximately 25% of stage iv non-small-cell lung cancer (nsclc) patients receive systemic therapy. For such patients, we examined factors affecting referral to a cancer centre (cc) and to medical oncology (mo), and use of systemic therapy.

Methods

Using the Glans-Look Lung Cancer database, we completed a chart review of stage iv nsclc patients diagnosed in Southern Alberta during 2003-2006 and 2010-2011, comparing median overall survival (mos), referral, and treatment in the two cohorts.

Results

Of the 922 patients diagnosed in 2003-2006 and the 560 diagnosed in 2010-2011, 94% and 82% respectively were referred to a cc, with 22% and 23% receiving traditional chemotherapy (tctx). Referral to a cc or mo and use of tctx correlated with survival (p < 0.0001): The mos duration was 11.2 months in those receiving tctx and 1.0 months in those not referred to a cc. The overall mos duration was similar in the two cohorts (4.1 months vs. 3.9 months, p = 0.47). Major reasons for lack of referral to mo included poor functional status, rapid decline, and patient wish, which were similar to the reasons for forgoing tctx. In the two cohorts, 87 (9.4%) and 42 (7.5%) patients received epidermal growth factor inhibitors, with a mos duration of 16.2 months. Multivariable analysis showed that male sex [hazard ratio (hr): 1.16; p = 0.008] and pulmonary embolus (hr: 1.2; p = 0.002) correlated with worse survival. In contrast, receipt of chemotherapy (hr: 0.5; p < 0.001) and enrolment in a clinical trial (hr: 0.76; p = 0.049) correlated with better survival.

Conclusions

Our experience confirms that, over time, uptake of systemic therapy, including tctx and targeted therapy, changed little despite their established efficacy. Most of the factors limiting systemic therapy uptake appear to be non-modifiable at the time of referral. Rapid diagnosis and the availability of well-tolerated drugs for all nsclc patients will likely be the most important factors in increasing systemic therapy uptake in this population.

Assessment of treatment patterns associated with injectable disease-modifying therapy among relapsing-remitting multiple sclerosis patients

Background

Availability of oral disease-modifying therapy (DMT) for relapsing–remitting multiple sclerosis (RRMS) may affect injectable DMT (iDMT) treatment patterns.

Objective

The objective of this paper is to evaluate iDMT persistency, reasons for persistency lapses, and outcomes among newly diagnosed RRMS patients.

Methods

Medical records of 300 RRMS patients initiated on iDMT between 2008 and 2013 were abstracted from 18 US-based neurology clinics. Eligible patients had ≥3 visits: pre-iDMT initiation, iDMT initiation (index), and ≥1 visit within 24 months post-index. MS-related symptoms, relapses, iDMT treatment patterns (i.e. persistency, discontinuation, switching, and restart), and reasons for non-persistency were tracked for 24 months.

Results

At 24 months, iDMT persistency was 61.0%; 28.0% of patients switched to another DMT, 8.0% discontinued, and 3.0% stopped and restarted the same iDMT. The most commonly identified reasons for non-persistency were perceived lack of efficacy (22.2%), adverse events (18.8%), and fear of needles/self-injecting (9.4%). At 24 months, 38.0% of patients had experienced a relapse and 11.0% had changes in MRI lesion counts. Patients without MS-related symptoms at index reported increases in the incidence of these symptoms at 24 months.

Conclusions

Non-persistency with iDMT remains an issue in the oral DMT age. Many patients still experienced relapses and disease progression, and should consider switching to more effective therapies.

Adenoid cystic carcinoma of head and neck: clinical predictors of outcome from a Canadian centre

OBJECTIVES

Adenoid cystic carcinoma (acc) is often treated with surgery, with or without adjuvant radiation therapy (rt). We evaluated disease characteristics, treatments, and potentially prognostic variables in patients with acc.

METHODS

Our retrospective analysis considered consecutive cases of acc presenting at a tertiary care hospital between 2000 and 2014. Factors predictive of overall survival (os) and disease-free survival (dfs) were identified by univariate analysis.

RESULTS

The 60 patients analyzed had a mean age of 58 years (range: 22-88 years), with a 2:1 female:male ratio. Tumour locations included the major salivary glands (40% parotid, 17% submandibular and sublingual), the oro-nasopharyngeal cavity (27%), and other locations (16%). Of the 60 patients, 35 (58%) received surgery with adjuvant rt; 12 (20%), rt only; 13 (22%), surgery only. Of 18 patients (30%) who experienced a recurrence within 5 years, 3 (5%) developed local recurrence only, and the remaining 15 (25%), distant metastasis. The 5-year os and dfs were 64.5% [95% confidence interval (ci): 45.9% to 78.1%] and 46.2% (95% ci: 29.7% to 61.2%) respectively. In patients without recurrence, 5-year os was 77% (95% ci: 52.8% to 89.9%), and in patients with recurrence, it was 42.7% (95% ci: 15.8% to 67.6%). Patients treated with rt only had a 5-year os of 9.2%. Predictors of 5-year dfs were TNM stage, T stage, nodal status, treatment received, and margin status; age, nodal status, treatment received, and margin status predicted 5-year os.

CONCLUSIONS

Despite surgery and rt, one third of patients with acc experience distant recurrence. Patients whose tumours are not amenable to surgery have a poor prognosis, indicating a need for alternative approaches to improve outcomes.

First-, second-, third-line therapy for mRCC: benchmarks for trial design from the IMDC

BACKGROUND

Limited data exist on outcomes for metastatic renal cell carcinoma (mRCC) patients treated with multiple lines of therapy. Benchmarks for survival are required for patient counselling and clinical trial design.

METHODS

Outcomes of mRCC patients from the International mRCC Database Consortium database treated with 1, 2, or 3+ lines of targeted therapy (TT) were compared by proportional hazards regression. Overall survival (OS) and progression-free survival (PFS) were calculated using different population inclusion criteria.

RESULTS

In total, 2705 patients were treated with TT of which 57% received only first-line TT, 27% received two lines of TT, and 16% received 3+ lines of TT. Overall survival of patients who received 1, 2, or 3+ lines of TT were 14.9, 21.0, and 39.2 months, respectively, from first-line TT (P<0.0001). On multivariable analysis, 2 lines and 3+ lines of therapy were each associated with better OS (HR=0.738 and 0.626, P<0.0001). Survival outcomes for the subgroups were as follows: for all patients, OS 20.9 months and PFS 7.2 months; for those similar to eligible patients in the first-line ADAPT trial, OS 14.7 months and PFS 5.6 months; for those similar to patients in first-line TIVO-1 trial, OS 24.8 months and PFS 8.2 months; for those similar to patients in second-line INTORSECT trial, OS 13.0 months and PFS 3.9 months; and for those similar to patients in the third-line GOLD trial, OS 18.0 months and PFS 4.4 months.

CONCLUSIONS

Patients who are able to receive more lines of TT live longer. Survival benchmarks provide context and perspective when interpreting and designing clinical trials.

Erythrocyte ghost-mediated gene delivery for prolonged and blood-targeted expression

This study reports the use of erythrocyte ghosts (EG) as a biocompatible nonviral delivery system for extended circulation and prolonged expression of plasmid DNA in the blood. Murine interleukin-2-expressing plasmid DNA was efficiently loaded to EG by electroporation in hypotonic condition. The presence of plasmid DNA in EG was confirmed by fluorescence-labeled plasmid DNA. At 21 min after intravenous administration into mice, the level of plasmid DNA in the blood was 92 000-fold higher following EG-mediated delivery as compared to the injection of naked form. EG-mediated gene delivery revealed higher and more prolonged mRNA expression levels of plasmid DNA in the blood until 9 days after the single intravenous injection. Moreover, plasmid DNA-loaded EG showed gene expression targeted to the blood cells. At 3 days post-dose, substantial expression levels of plasmid DNA delivered in EG were observed only in the blood and not in the other organs. Of the blood cells, the subpopulation containing granulocytes showed higher expression of plasmid DNA than mononuclear cells. These results indicate the potential of EG as a safe, prolonged and blood-targeted delivery system of therapeutic genes.

Enhanced immunogenicity of human papillomavirus 16 L1 genetic vaccines fused to an ER-targeting secretory signal peptide and RANTES

To increase the potency of human papillomavirus (HPV) DNA vaccines, we constructed a series of HPV16 L1 vaccines genetically fused with a secretion signal and/or immune cell-recruiting RANTES. The DNA vaccines encoding secretory HPV L1 were constructed by inserting HPV L1 gene into a vector with an ER-targeting secretory signal sequence. The expression plasmid encoding secretory HPV L1 (pER/L1) was fused with cDNA of RANTES, generating pER/L1/R. For comparison, HPV L1 genes were cloned into pVAX1 vector with no signal sequence (pL1), and further linked to the N-terminus (pL1/R) or C-terminus of RANTES (pR/L1). The secretion of L1 proteins was observed in the pER/L1, pER/L1/R, and pR/L1-transfected cells, except the pL1/R-transfected group. Cytoplasmic localization of L1 protein was observed in the cells transfected with pL1/R, but not with pER/L1/R at 48 h after transfection. In mice, RANTES-fused vaccines more effectively elicited the levels of HPV16 L1-specific IgG and IgG2a antibodies than pL1. Of RANTES-fused vaccines, pER/L1/R encoding the secreted fusion protein induced the highest humoral and CD8(+) T-cell-stimulating responses. These results suggest that the immunogenicity of HPV L1 DNA vaccines could be enhanced by genetic fusion to a chemokine and secretory signal peptide sequences.

Polyethylenimine-mediated cellular uptake, nucleus trafficking and expression of cytokine plasmid DNA

Although polyethylenimine (PEI) has been widely used as a nonviral vector, there is little mechanistic understanding on PEI-mediated delivery. Here, we studied whether the expression of murine interleukin-2 (mIL-2) plasmids could be improved by complexation with PEI at various N/P ratios, and whether the cellular uptake, nuclear translocation, and retention of plasmids could be affected by the N/P ratios. Compared with the naked mIL-2, PEI/mIL-2 complexes showed at least two orders of magnitude higher expression at Raw264 cells in the N/P ratio-dependent manner. PEI-mediated cellular uptake and nuclear trafficking of plasmids, quantitated by competitive polymerase chain reaction, also depended on the N/P ratios showing the highest cell and nuclear levels of plasmids at 10/1. The higher cellular levels of plasmid DNA after PEI-mediated delivery were also observed in other cell lines. Unlike naked plasmids, PEI/mIL-2 complexes (N/P ratios >/=4/1) showed prolonged cellular and nuclear retention of mIL-2 plasmids. The nuclear translocation and higher cellular level of plasmids given in PEI complexes were similarly observed by fluorescence microscopy. Moreover, PEI/mIL-2 complexes revealed high stability against DNase I, partly explaining the prolonged subcellular retention. These results indicate that the expression of plasmid mIL-2 might be highly enhanced by complexation with PEI and that such increased expression could be attributed by the higher cellular uptake, nuclear translocation and prolonged retention.

Nasal absorption and biodistribution of plasmid DNA: an alternative route of DNA vaccine delivery

Nasal administration is emerging as a new route of DNA vaccine delivery. We aimed to study the extent of absorption and biodistribution of intranasally administered plasmid DNA. After intranasal administration, the level of plasmid DNA in the serum peaked at 1.5 h. The ratio of the area under the concentration (AUC) after intranasal administration of DNA over the AUC after intravenous administration was 0.14. At 15 min post inoculation, the highest organ distribution was observed in the liver and the cervical lymph nodes showed the highest level among the lymph nodes. At 24 h a higher localization of plasmids to the brain than to the lung and spleen was notable. A significant level of mRNA expression was observed in the lymph nodes. These results suggest that plasmid DNA can be substantially absorbed and distributed to the lymph nodes after intranasal administration, partly explaining the systemic immunogenicity of intranasally administered plasmid DNA vaccines.

Increased expression and localization of a serine protease inhibitor, protease nexin-1 (PN-1), in the ovary and uterus during implantation in rat

Protease nexin-1 (PN-1) is a serine protease inhibitor (serpin) that inactivates several proteases, including thrombin, urokinase, plasminogen activators (PA), and plasmin. It also plays a role in regulating proteolytic activity generated by PA system. PN-1 is known to be involved in tissue remodeling, cellular invasiveness, matrix degradation, and tumor growth. However, the role of PN-1 in female reproductive tracts, such as the uterus, ovary, and oviduct, during pregnancy is not known. The present study was designed to investigate the changes of PN-1 mRNA level and localization in the tracts during implantation and early pregnancy by using reverse transcription (RT)-polymerase chain reaction (PCR) and in situ hybridization. We found that PN-1 mRNA levels were coordinately regulated during early pregnancy in a stage- and tissue-specific manner, such that an increased expression of PN-1 gene appeared at the time of the implantation period in the uterus and ovary. Both the uterus and ovary synthesized PN-1 mRNA and their maximal PN-1 expression occurred on Day 6.5 postcoitum (p.c.). On 13.5 days of pregnancy, PN-1 level was low in the uterus and ovary. On the other hand, PN-1 mRNA in the oviduct did not show after 6.5 days of pregnancy. It appears that PN-1 mRNA in the uterus and ovary was highly regulated during early pregnancy, which might have an important role in implantation of rat blastocysts. PN-1 was localized in endometrial stromal cells of the uterus and in granulosa cells of the unstimulated primary follicles in the ovary during periimplantation period. Also, PN-1 mRNA expression was higher at implantation period than that at nonimplantation period of pregnancy. In conclusion, PN-1 is expressed in female reproductive tracts and highly regulated during implantation and early pregnancy.

Gene amplification and expression of the DNA repair enzyme, N-methylpurine-DNA glycosylase (MPG) in HPV-infected cervical neoplasias

BACKGROUND

Lethal and mutagenic damages of DNA is caused by a variety of agents including viruses. It is known that HPV is one of the major causes of cervical carcinogenesis and that cells eliminate DNA lesions with DNA repair enzymes. However, the role of N-methylpurine-DNA glycosylase (MPG) is not known in the development of cervical cancer.

MATERIALS AND METHODS

Multiplex polymerase chain reaction (PCR) was used for the detection and typing of HPV in the biopsy. Gene amplification of MPG was measured by a PCR-based assay. The mRNA levels of MPG were determined by reverse transcription-PCR using hypoxanthine-guanine phosphoribosyl transferase as the reference gene. An immunohistochemical technique was used to examine the distribution of MPG in the tissues.

RESULTS

Of 68 Korean cervical neoplasia patients, 86.8% showed HPV infection. High-risk HPV 16/18 were the most prevalent but positive only in 47.3% of the invasive cancer patients. Gene amplification of MPG was significantly increased in high-risk HPV-infected tissues as compared to low-risk HPV-infected and normal tissues (p < 0.05). The mRNA levels of MPG were higher in HPV-infected invasive carcinoma than normal cervical tissues. Immunohistochemical staining revealed that the intracellular expression and distribution (localization) of MPG altered in the cervical neoplasia. Interestingly, MPG expression in CIN III and invasive carcinoma (IC) was much higher than normal and CIN I. Granular positivity of MPG was notable in the perinuclear regions of the cytoplasm in HPV-infected invasive cancer.

CONCLUSION

This is the first report on MPG expression in cervical neoplasia. Our results indicate that the gene amplification and expression of MPG were increased in high-risk HPV-infected cervical neoplasias and the intracellular distribution of MPG protein was altered, suggesting a role of MPG in carcinogenesis.

Soluble adhesion molecules and cytokines in tumor-associated tissue eosinophilia of nasopharyngeal carcinoma

The phenomenon of tumor-associated tissue eosinophilia (TATE) is seen in some cases of nasopharyngeal carcinoma (NPC) and is characterized by the eosinophils breaking through the vascular wall and pervading the tumor stroma. The margination and trans-endothelial migration of eosinophils in a typical inflammatory reaction depend on the activating effects of certain cytokines and the expression of adhesion molecules on the eosinophils and endothelial cells. In order to investigate whether the adhesion molecules and activating cytokines play a role in eosinophil tumor infiltration, we measured the serum levels of 3 adhesion molecules, intercellular adhesion molecule-1, E-selectin and vascular cell adhesion molecule-1, and 2 cytokines, IL-3 and IL-5, in 60 NPC patients and 40 normal healthy subjects. We found that the NPC patients had higher serum levels of all three soluble adhesion molecules than the normal subjects but the levels of adhesion molecules failed to correlate with the TATE phenomenon. The levels of IL-3 and IL-5 appeared not to differ between the NPC and control groups. We postulate that the three soluble adhesion molecules do not play a major role in TATE and that their elevation in serum may be due to local and/or systemic immune responses.

Freezing immature oocytes

The establishment of a long-term preservation system for mammalian oocytes is important for the development of both biological and medical sciences. A number of efforts have been made to develop this system. In human reproductive medicine, the development of an oocyte cryopreservation system can improve the efficacy of the current assisted reproductive technology (ART) for infertile patients with severe reproductive disorders. In this article, the technical development of cryopreservation programs for human oocytes and its biological background were reviewed. Clinical outcome after the use of this technology was further introduced.

Embryotropic role of hemoglobin and ethylenediaminetetraacetic acid in preimplantation development of ICR mouse 1-cell embryos

OBJECTIVE

To evaluate embryotropic action of hemoglobin (Hb) and ethylenediaminetetraacetic acid (EDTA) on preimplantation embryo development.

DESIGN

In vitro model study using mouse embryos.

SETTING

University affiliated hospital, Pochon CHA University.

ANIMALS

Four-week-old block strain ICR mice naturally mated after superovulation.

INTERVENTION(S)

One-cell embryos were cultured in serum-free, modified preimplantation-1 medium, to which 1 microg/ml Hb and/or 0.1 mM EDTA were added.

MAIN OUTCOME MEASURE(S)

Preimplantation development and blastomere number.

RESULT(S)

More (P<.05) 1-cell embryos developed to the 4-cell (52% vs. 67%-84%), 8-cell (48% vs. 65%-81%), and blastocyst (40% vs. 61%-79%) stages after the addition of hemoglobin (Hb) and/or EDTA than after no addition. Highest proportion of embryos developed to each stage after the combined addition of Hb+EDTA. EDTA specifically stimulated the development before the 8-cell stage, which was as similar as Hb+EDTA. On the contrary, higher ratio of morula to blastocyst transformation was obtained after the addition of Hb or Hb+EDTA than after no addition (0.76 vs. 0.96-0.98). Significant increases in the cell number of blastocysts (46.5-47.2 vs. 53.2 cells), inner cell mass (ICM) cells (16.7-17.5 vs. 21 cells), and the ratio of ICM cells to trophoblasts (0.3-0.37 to 0.39) were found after the combined addition of Hb+EDTA, compared with no addition or with the addition of EDTA or Hb alone.

CONCLUSIONS

Hb and EDTA have stage-specific effects on supporting preimplantation embryo development; Hb promotes both the development before the 8-cell stage and the morula to blastocyst transformation, whereas EDTA mainly promotes the development to the 8-cell stage. The combined exposure of embryos to Hb and EDTA improves not only preimplantation development but also the growth and quality of blastocysts.

Spatial expression of a DNA repair gene, N-methylpurine-DNA glycosylase (MPG) during development in mice

BACKGROUND

DNA repair is a crucial phenomenon that maintains the chromosome integrity of genome which are continuously damaged by endogenous and exogenous alkylating agents. If the damaged DNA is not repaired, it may lead to mutation, chromosomal aberration, aging and cancer. N-methylpurine-DNA glycosylase (MPG), a ubiquitous DNA repair enzyme, removes N-methylpurine and other damaged purines in DNA.

MATERIALS AND METHODS

MPG mRNA expression was revealed at various stages of mouse development from day 7.5 p.c. (post coitum) embryo to day 400 mature adult by Northern blot hybridization or RT-PCR.

RESULTS

MPG transcripts were abundant in the mouse embryo during pregnancy and in adult testis and ovary. The MPG mRNA level in the testis was low in 1-week-old mice, but the level showed its maximum among the organs tested in 4-week-old young adults. In placenta, the level of MPG mRNA continuously decreased from day 7.5 p.c. to day 17.5 p.c.

CONCLUSIONS

The spatial expression of MPG gene is highly regulated. Transcription of MPG is maximum in rapidly dividing and growing tissues during development. These data suggest that an elevated rate of MPG transcription is required for DNA replication.

In vitro maturation and in vitro fertilization of bovine oocytes cultured in a chemically defined, protein-free medium: effects of carbohydrates and amino acids

This study was conducted to examine the effects of carbohydrates and amino acids on the maturation and fertilization of bovine oocytes. To evaluate the effect of each treatment without any unpredictable interference, oocytes were cultured in a simply defined medium (modified Tyrode's medium; mT) without the addition of hormones and proteins. In Experiment 1, oocyte maturation to the metaphase-II stage was significantly (P<0.0001) enhanced after the addition of glucose (5.6 mM), lactate (10 mM) and/or pyruvate (0.5 mM) to mT (37-74%) than after no addition (0%). In mT supplemented with glucose, the addition of 19 essential and non-essential amino acids (aa; 0, 0.01, 0.1, 1, 5 or 10%) did not further improve in vitro maturation (Experiment 2) or in vitro fertilization (Experiment 3) of oocytes. However, more (P<0.05) pronuclear formation after in vitro-insemination was found in oocytes matured in mT with 1% aa and glucose than in oocytes matured in mT with glucose alone (56% vs. 35%). Penetration of spermatozoa into the ooplasm was initiated at 3 h after insemination and pronuclear formation from 8 h (Experiment 4). When cultured inseminated oocytes were examined up to 192 h post insemination, a significant (P<0.05) increase in the number of 2-cell (18 v. 38%) and 8-cell embryos, (7 v. 20%) and morulae (0 v. 8%) was found after the addition of 1% aa to mT with glucose than after no addition (Experiment 5). A limited number of oocytes matured in mT with aa and glucose developed to the blastocyst stage (6%). These results indicate that exogenous carbohydrates and amino acids are prerequisites for the maturation and fertilization of bovine oocytes in vitro. Glucose alone promotes the nuclear maturation of oocytes, whereas amino acids aid the pronuclear formation of fertilized oocytes.

Pregnancies and deliveries after in vitro maturation culture followed by in vitro fertilization and embryo transfer without stimulation in women with polycystic ovary syndrome

OBJECTIVE

To improve the efficacy of an IVF-ET program for unstimulated patients with polycystic ovary syndrome (PCOS) with the use of culture for oocyte maturation.

DESIGN

Prospective studies with the comparison of different ET procedures from March 1995 through February 1998.

SETTING

University-affiliated hospital.

PATIENT(S)

Ninety-four cycles in 64 consenting patients with PCOS.

INTERVENTION(S)

Immature oocytes were retrieved from unstimulated patients with PCOS and subsequently cultured and fertilized in vitro. Zygote intrafallopian transfer (ZIFT), uterine ET, or a combined approach of ZIFT + uterine ET was subsequently performed.

MAIN OUTCOME MEASURE(S)

Laboratory and clinical data.

RESULT(S)

Among 1, 280 immature oocytes (13.6 +/- 7.5 oocytes per patient) retrieved, 89% (1,139) were morphologically normal, and 62.2% (708/1,139) of the normal oocytes matured in vitro after culture for 48 hours. When intracytoplasmic sperm injection was performed, 68% (481/708) developed to the normal pronuclear stage, and 88.1% of the embryos cocultured with Vero cells (266/302) cleaved. Eighty-five ET cycles were conducted and pregnancy was established in 23 cycles (27.1%), which consisted of 8 after uterine ET and 15 after a combined approach. Seventeen patients delivered 20 normal infants.

CONCLUSION(S)

The IVF-ET method using no ovarian stimulation followed by in vitro maturation culture can be a feasible assisted reproductive technology for treatment of PCOS with various complications.

In vitro blastocyst formation of human oocytes obtained from unstimulated and stimulated cycles after vitrification at various maturational stages

OBJECTIVE

To evaluate the developmental competence and chromosomal normality of oocytes vitrified at various times after maturation culture.

DESIGN

In vitro model study.

SETTING

A university-affiliated hospital.

PATIENT(S)

Unstimulated women who underwent cesarean section or oophorectomy and infertile women who underwent a long protocol of GnRH stimulation.

INTERVENTION(S)

Retrieved oocytes were vitrified at 0 or 48 hours after culture in unstimulated cycles and at 0, 8-15, or 24-28 hours after culture in stimulated cycles.

MAIN OUTCOME MEASURE(S)

Postthaw morphologic normality, maturation, fertilization, cleavage, blastocyst formation, and chromosome number.

RESULT(S)

In the 53 oocytes that were obtained from unstimulated cycles, no statistically significant differences were found in rates of morphologic normality (range, 56%-63%) or fertilization (range, 31%-37%) according to the time of vitrification. In the 50 oocytes that were obtained from stimulated cycles, more of those that were vitrified at 24-28 hours were morphologically normal than those that were vitrified at 0 or 8-15 hours. Regardless of these differences, high cleavage rates (83%-100%) were obtained that did not differ significantly among the treatment groups. In both cycles, 20%-43% of cleaved oocytes developed to the blastocyst stage by 6 days after IVF. All the karyotyped blastocysts, three from unstimulated cycles and four from stimulated cycles, had a normal number of chromosomes.

CONCLUSION(S)

Vitrified and thawed oocytes from unstimulated or stimulated cycles developed to the blastocyst stage, regardless of when vitrification occurred; the number of chromosomes in the blastocysts was normal.

Improved human oocyte development after vitrification: a comparison of thawing methods

OBJECTIVE

To evaluate the developmental competence of vitrified human oocytes thawed using two different methods to establish an effective cryopreservation protocol.

DESIGN

In vitro model study.

SETTING

University-affiliated hospital.

PATIENT(S)

Patients who underwent a long protocol of ovarian stimulation with GnRH and gonadotropins.

INTERVENTION(S)

Vitrified oocytes from the patients were thawed using either a four-step method with 2.5-minute intervals or a four-step method with 5-minute intervals.

MAIN OUTCOME MEASURE(S)

Morphologic normality, maturation, fertilization, and development of the oocytes to the blastocyst stage.

RESULT(S)

The two thawing methods did not significantly affect the morphologic normality (84%-100%), maturation (75%-100%), fertilization (38%-71%), polyspermy (more than three pronuclei; 0%-20%), or parthenogenetic activation (only female pronucleus; 0%-8%) of the vitrified oocytes. However, more of the vitrified oocytes developed to the two-cell (71%-100% versus 50%-67%), four-cell (71%-93% versus 0%-50%), eight-cell (46%-71% versus 0%), and blastocyst (23%-36% versus 0%) stages after thawing using the four-step method with 2.5-minute intervals than using the four-step method with 5-minute intervals.

CONCLUSION(S)

Vitrified human oocytes developed to the blastocyst stage with IVF. A four-step thawing method with 2.5-minute intervals was more effective in supporting preimplantation embryo development than a four-step thawing method with 5-minute intervals.

Development of in vitro matured bovine oocytes after cryopreservation with different cryoprotectants

In vitro matured bovine oocytes at the metaphase-II stage were slowly frozen in phosphate buffered saline (PBS) containing 1.0 M glycerol, 1.0 M dimethylsulfoxide (DMSO) or 1.0 M propylene glycol (PROH). When thawed rapidly, more (P<0.05) oocytes were morphologically normal after being frozen with DMSO (86%) or PROH (83%) than with glycerol (62%). When inseminated in vitro with frozen-thawed bull spermatozoa, higher (P<0.05) penetration rates were observed in DMSO (79%) or PROH (76%) than in glycerol (48%). The percentages of oocytes developing to the 2-cell stage at 48 h postinsemination were also significantly (P<0.05) higher in DMSO (51%) and PROH (54%) than in glycerol (33%). However, a significant increase in the proportions of 8-cell embryos (46 vs 21 to 26%; P<0.05) at 72 h postinsemination and morulae (14 vs. 6 to 8%; P<0.05) was derived from oocytes frozen with PROH than with DMSO or glycerol. In conclusion, the type of cryoprotectant used is one of the critical factors affecting developmental competence of bovine oocytes frozen at the metaphase-II stage. For this stage of oocytes, PROH was the most effective, yielding a large number of 8-cell embryos and morulae than either glycerol or DMSO in a slow freezing method combined with a 3-step thawing protocol.

Effect of dietary lipid on gamma-glutamyl transferase-positive foci during hepatocarcinogenesis in rats

The effect of dietary lipid on gamma-glutamyl transferase-positive (GGT-positive) foci was investigated. Female Sprague-Dawley rats were dosed with diethylnitrosamine (15 mg/kg) at 24 h of age. After weaning, they were fed nutritionally complete semipurified diets for 3 months. Rats fed 15% corn oil had significantly lower hepatic phospholipid eicosapentaenoate and docosahexaenoate than rats fed 7.5% corn oil plus 7.5% fish oil, 5% corn oil plus 10% fish oil (P < 0.05). However, rats fed 15% corn oil had significantly greater hepatic phospholipid arachidonate than rats fed the other two diets (P < 0.05), suggesting that n-3 polyunsaturated fatty acids were incorporated into hepatic phospholipid at the expense of n-6 polyunsaturated fatty acids. Hepatic PGF2alpha content was significantly greater in rats fed 15% corn oil than in rats fed the other two diets (P < 0.05). Rats fed fish oil had significantly lower hepatic vitamin E content than rats fed corn oil (P < 0.05). Hepatic lipid peroxidation (TBARS) tended to increase with increased dietary fish oil (P < 0.05). Dietary lipid did not influence GGT-positive foci area or number. In conclusion, dietary lipid affected hepatic PGF2alpha production, however, showed no effect on GGT-positive foci area and number. This may suggest that PGF2alpha is not the underlying mechanism for GGT-positive foci during hepatocarcinogenesis.

Chromosome and spindle configurations of human oocytes matured in vitro after cryopreservation at the germinal vesicle stage

OBJECTIVE

To investigate effects of cryoprotectant and cryopreservation on the chromosome and microtubule configuration of human immature oocytes.

DESIGN

Intact cumulus-enclosed immature oocytes were collected from unstimulated ovaries and divided into three groups: group 1, no treatment (control); group 2, only 1,2-propanediol treatment, and group 3, cryopreserved oocytes. Oocytes in groups 1 and 2, and oocytes that survived after cryopreservation in group 3 were cultured for 48 hours.

SETTING

Infertility Medical Center at the CHA General Hospital, Seoul, Korea.

PATIENT(S)

Oocytes were obtained from patients undergoing gynecologic surgery.

MAIN OUTCOME MEASURE(S)

Maturation rate and abnormality in chromosomes by fluorescence in situ hybridization and in the spindle by immunostaining for tubulin.

RESULT(S)

There was no effect of propanediol-only treatment on the chromosomal (41.4%) and spindle abnormalities (35.3%) in group 2 compared with control oocytes (31.8% and 22.2%, respectively), whereas a statistically significant increase in abnormalities in chromosomes (77.8%) and spindles (70%) was found in group 3.

CONCLUSION(S)

Human oocytes matured in vitro after cryopreservation at the germinal vesicle stage showed increased incidence of chromosomal and spindle abnormalities. These abnormalities may impair the capacity for further development of the embryos derived from frozen-thawed oocytes.

Corn oil enhances gamma-glutamyl transpeptidase-positive foci development in the presence of phenobarbital during hepatocarcinogenesis in rats

We investigated the effects of type of dietary fat and phenobarbital on gamma-glutamyl transpeptidase-positive foci development. Four groups of six female Sprague-Dawley rats were initiated with diethylnitrosamine (15 mg/kg) at 24 hours of age. After weaning, they were fed nutritionally complete semipurified diets containing 15% corn oil or 5% corn oil + 10% fish oil and supplemented with 5,000 ppm vitamin E with or without phenobarbital (500 ppm) for three months. Dietary fish oil significantly increased hepatic phospholipid eicosapentaenoate and docosahexaenoate concentrations and decreased arachidonate concentration compared with 15% corn oil (p < 0.05). Corn oil (15%) significantly increased hepatic prostaglandin F2 alpha concentration compared with 10% fish oil (p < 0.05). Phenobarbital significantly stimulated glutathione S-transferase activity in both dietary fat groups (p < 0.05). In the absence of phenobarbital, type of dietary fat showed no effect on hepatic gamma-glutamyl transpeptidase-positive foci development. However, in the presence of phenobarbital, 15% corn oil significantly enhanced gamma-glutamyl transpeptidase-positive foci development compared with 10% fish oil (p < 0.05). Phenobarbital showed a strong tumor-promoting action in both dietary groups. In conclusion, there was an interaction between type of dietary fat and phenobarbital on gamma-glutamyl transpeptidase-positive foci development during hepatocarcinogenesis in rats.

No inhibition of gamma-glutamyl transpeptidase-positive foci by vitamin E with or without phenobarbital

The effect of vitamin E on gamma-glutamyl transpeptidase-positive foci, with or without phenobarbital, was investigated. Groups of six female Sprague-Dawley rats were initiated with diethylnitrosamine (15 mg/kg) at 24 hours of age. After weaning, they were fed diets with 10% (wt/wt) fish oil; the diets contained 0, 5,000 or 15,000 ppm vitamin E supplementation with or without phenobarbital (500 ppm) for six months. Phenobarbital significantly increased liver weight and liver weight as a percentage of body weight (p < 0.05), suggesting a liver hypertrophic effect of phenobarbital. Phenobarbital significantly decreased hepatic phospholipid arachidonate, eicosapentaenoate, and docosahexaenoate (p < 0.05); this may indicate that phenobarbital stimulates phospholipase A2 activity and results in the increased release of polyunsaturated fatty acids from phospholipids and the decrease of hepatic phospholipid polyunsaturated-to-saturated fat ratio. In rats fed phenobarbital, hepatic vitamin E content was lower than in rats fed no phenobarbital; this suggests that phenobarbital causes oxidative stress or induces enzymes that metabolize the vitamin. Phenobarbital exposure significantly increased hepatic prostaglandin F2 alpha and glutathione S-transferase activity (p < 0.05). Vitamin E did not influence hepatic gamma-glutamyl transpeptidase-positive foci area and number with or without phenobarbital, and phenobarbital showed a strong promoting action on enzyme-altered hepatic foci.

Effects of 1,2-propanediol and freezing-thawing on the in vitro developmental capacity of human immature oocytes

OBJECTIVE

To investigate effects of 1,2-propanediol and freezing-thawing treatment on the maturation and developmental capacity of the human immature oocytes obtained from unstimulated ovaries.

DESIGN

Intact cumulus-enclosed immature oocytes collected from unstimulated ovaries were divided into three groups, such as no treatment as control (group 1), only 1,2-propanediol-treated (group 2), and cryopreserved group (group 3). Oocytes in group 1, group 2, and survived oocytes from cryopreservation in group 3 were cultured for 48 hours. A random selection of matured oocytes was inseminated with normal donor sperm to evaluate the fertilization and developmental capacity.

SETTING

Infertility Medical Center at the CHA General Hospital, Seoul, Korea.

PATIENT(S)

Oocytes were obtained from patients undergoing gynecological surgery.

MAIN OUTCOME MEASURE(S)

Rates of survival, maturation to metaphase II, fertilization, and cleavage.

RESULT(S)

Survival rate after freezing-thawing in group 3 was 55.1% (54/98). Oocytes were cultured in Dulbecco's modified Eagle's medium (DMEM) supplemented with 20% fetal bovine serum, 10 IU/mL pregnant mare serum gonadotropin, and 10 IU/mL hCG. Maturation rates were 76.8% (63/82), 67.1% (47/70), and 59.3% (32/54) in the groups 1, 2, and 3, respectively. Maturation rate in group 3 was significantly lower than that of group 1. Fertilization rates were 90.5% (19/21), 81.0% (17/21), and 42.9% (6/14), and cleavage rates were 94.7% (18/19), 88.2% (15/17), and 16.7% (1/6) in groups 1, 2, and 3, respectively. Fertilization and cleavage rates of survived oocytes in group 3 also were significantly lower than those of groups 1 and 2.

CONCLUSION(S)

Results suggest that the pretreatment with 1.5 M 1,2-propanediol itself before the freezing has no inhibitory effect on the maturation, fertilization, and cleavage of human immature oocytes in vitro. However, the freezing-thawing procedure used had detrimental effects on the maturation and developmental capacity.

Regulatory effects of dietary n-3 and n-6 lipids on plasma and hepatic lipid levels, liver cell number and microsomal protein content in spontaneously hypertensive rats

Weanling male spontaneously hypertensive rats were fed semipurified diets containing either corn or fish oil for 8 weeks. Rats fed on fish oil diet had significantly lower plasma triglyceride, total cholesterol and HDL-cholesterol levels than rats fed on corn oil diet (P < 0.05). Moreover, rats fed on fish oil diet had significantly lower liver total lipid and triglyceride concentrations than rats fed on corn oil diet (P < 0.05). Dietary lipids were reflected in plasma fatty acid composition. Rats fed on fish oil diet had significantly greater plasma eicosapentaenoate (EPA) and docosahexaenoate (DHA) (n-3 PUFAs) with an accompanying decrease in plasma linoleate (LA) and arachidonate (AA) (n-6 PUFAs), in comparison with the rats fed corn oil (P < 0.05). Those results would suggest that the n-3 PUFAs were incorporated into plasma lipids at the expense of the n-6 PUFAs. Rats fed on corn oil diet had significantly greater liver DNA content than rats fed on fish oil diet (P < 0.05), thereby implying that the n-3 PUFAs in fish oil had an inhibitory effect on liver cell proliferation. Furthermore, rats fed on fish oil diet had significantly greater hepatic microsomal protein content than rats fed on corn oil diet (P < 0.05), indicating that fish oil exerted a stimulatory effect on hepatic microsomal enzymes.

Immunosuppression by corticosteroid has no effect on the pregnancy rate in routine in-vitro fertilization/embryo transfer patients

Immunosuppression by exogenous corticosteroids has been used to improve the rates of embryo implantation and pregnancy in in-vitro fertilization (IVF) patients who have micromanipulated embryos replaced. The present study was conducted, in a prospective design, to evaluate effects of corticosteroid on the pregnancy rate in IVF/embryo transfer patients who have non-micromanipulated embryos replaced. Infertile women < 40 years old with tubal factor were included in this study. Patients were grouped according to the different follicle stimulation protocols, and received various doses of 16 beta-methylprednisolone (0, 16 or 60 mg/day) for 4 days from the day of oocyte retrieval. The mean age, duration of infertility, length of folliculogenesis and serum oestradiol concentrations at the time of human chorionic gonadotrophin (HCG) injection were not significantly different between control and corticosteroid-treated groups of patients. Short-term immunosuppression by 16 beta-methylprednisolone administration did not show any effects on the pregnancy and miscarriage rates in IVF/embryo transfer patients. Also, immunosuppression showed no dose effects in any groups. There was no relationship between the types of follicle stimulation protocols and the effect of 16 beta-methylprednisolone. Therefore, we concluded that short-term immunosuppression by exogenous corticosteroids in IVF/embryo transfer patients who have embryos with intact zona pellucida replaced has neither positive nor negative effects on pregnancy rates.

Viability of Human Follicular Oocytes Collected from Unstimulated Ovaries and Matured and Fertilized in vitro

Immature human follicular oocytes were collected from unstimulated ovaries, matured and fertilized in vitro and then transferred to patients with no ovarian dysfunction such as premature ovarian failure. From 11 1 consenting donors, 422 immature oocytes were collected from 97 ovaries between January 1990 and October 1991. The number of oocytes collected from ovaries and their development were recorded so that comparisons could be made among donors of different ages and ovarian condition, such as menstrual cycle, cyclic and non-cyclic ovaries. The rate of fertilization in vitro showed a peak in the 31-40-year age group; however, there was no statistical difference in the rate of oocyte maturation and cleavage among the donors in the different age groups. Immature oocytes of the luted phase had a significantly higher maturation rate than those of the follicular phase. There was no significant difference in the number of recovered oocytes, or in the development of immature follicular oocytes, between cyclic and non-cyclic ovaries. Mature follicular fluid and peritoneal fluid had a significant effect on the development of immature follicular oocytes. Also, it was found that fertilized eggs cleaved more frequently in the medium containing hypoxanthine compared with the medium without hypoxanthine. Finally, from 21 transfer cycles, viable embryos were derived from immature follicular oocytes, resulting in two pregnancies, both leading to the birth of normal babies. These findings suggest that culture in vitro of immature follicular oocytes, from unstimulated ovaries, to a suitable condition, could be used optimally for clinical applications such as human ovum donation programmes.