سال:1388 | دوره: | شماره: |تعداد مقالات:8

Background: Embryonic stem (ES) cells are pluripotent cells conventionally isolated from early embryos. Studies have shown that ES cells serve as a practical model for biomedical studies. Objective: The aim of the present study was to optimize culture conditions for establishment of ES-like colonies from NMRI mouse blastocysts as well as 2-cell stage embryos. Materials and Methods: Both expanded blastocysts and 2-cell stage embryos were co-cultured on mouse embryonic fibroblast (MEF). Plating capacity and formation of Inner cell mass (ICM) were examined daily. The differentiation and growth behavior of ICM cells were examined with various procedures. ICMs derived from initially cultured 2-cell or blastocyst embryos were disaggregated either mechanically or enzymatically, and seeded onto MEF with or without leukemia inhibitory factor (LIF). The resulted colonies were disaggregated and reseeded onto MEF and the colonies that were morphologically similar to ES cells were evaluated for pluripotency using alkaline phosphatase (ALP) expression as a stem cell marker. Results: No morphologically good ES-like colony was isolated from 2-cell embryos after passages, while 273 (79%) good-looking ICMs were isolated from 352 blastocysts. Four sets of colonies remained undifferentiated following passages. Enzymatic method of ICM disaggregation was superior to the mechanical method. Besides, all ES-like colonies were obtained from the ICMs cultured in presence of MEF and LIF. Conclusion: Our results show that NMRI mouse ICMs could be isolated and cultured from blastocyst stage embryos with a suitable culture system and ES-like cell colonies remain undifferentiated when cultured with MEF and LIF.

Background: Preeclampsia is a disorder unique to pregnancy and has long been recognized as an important contributor of maternal and fetal morbidity and mortality. It is suggested that cytokines such as Tumor Necrosis Factor-alpha (TNF-a) have an important role in the pathogenesis of preeclampsia and may cause generalized endothelial dysfunction. Objective: The aim of this study was comparison of maternal serum TNF-a in severe and mild preeclampsia versus normal pregnancy. Materials and Methods: This study was performed on 37 women with preeclampsia (17 mild and 20 severe preeclampsia) and 41 normotensive pregnant women with similar gestational age at third trimester of pregnancy. All the preeclamptic cases had blood pressure ³ 140/90 mmHg, and proteinuria ³ 300 mg in a 24-h urine sample. Maternal serum TNF-a concentration was compared in all of them. Results: The level of TNF-a concentration was not statistically different between the studied groups. No significant correlation was found between preeclampsia and control group as they were compared in the view of maternal serum TNF-a concentration. Conclusion: These findings suggest that serum TNF-a is not significantly associated with preeclampsia.

Background: Acceptance of uterus and reaction between endometrium and embryo has an important role for implantation. Muc1, an integral membrane mucin, is expressed on the apical surface of uterine epithelial cells and could have effects on its receptivity.Objective: The aim of this study was to evaluate the changes in Muc1 expression of gravid mouse endometrium with and without hyperstimulation before implantation.Materials and Methods: Adult female NMRI mice were divided into control and experimental groups. Experimental group superovulated using an intraperitoneal injection of Pregnant Mare’s Serum Gonadotrophin (PMSG) followed 48 hours later by another injection of Human Chorionic Gonadotropic hormone (HCG). The female mice have mated with normal male mice. All control and hyperstimulated groups subdivided into six groups. After mating, female mice were examined by vaginal plaque as day of zero and in 0-5 days after copulation, they were sacrificed by cervical dislocation. Then the middle 1/3 parts of their uterine horns were obtained and stained by immunohistochemicaly technique for Muc-1 detection.Results: Our results showed that in the control and hyperstimulated groups, the Muc1 expression is markedly reduced in the luminal uterus epithelium at the time of implantation. Furthermore, luminal and glandular uterus epithelium did not exhibit the same decrease in Muc1 expression during the receptive phase.Conclusion: Ovarian hyperstimulation didn’t alter the Muc1 expression markedly in surface and glandular epithelium of endometrium, which could affect on its receptivity.

Background: There are evidences regarding the prevalence of dysfunction in sexual function and behavior in diabetic people. Experimental studies revealed a positive effect of withania somnifera on sexual function and behaviors.Objective: In this research, the effect of withania somnifera on sexual function in diabetic male Wistar rats was assessed by measuring the serum levels of testosterone, progesterone, estrogen, FSH and LH.Materials and Methods: Experimental diabetes mellitus type I was induced by intraperitoneal injection of a single dose (60 mg/kg) of streptozotocin (STZ) in Wistar male rats. Oral withania somnifera root was given in pelleted food at ratio of 6.25% for 4 weeks. The levels of gonadadotropic hormones (LH, FSH), progesterone, estrogen and testosterone in animals’ serum were determined after 4 weeks in all groups. Results: Withania somnifera root was effective in lowering FSH serum level in somnifera-treated animals compared to controls (p<0.05) in both diabetic and non-diabetic groups, whereas progesterone (p<0.05), testosterone (p<0.05) and LH levels (p<0.001) were significantly higher in non-diabetic treated animals. Oral somnifera root was also able to reverse the reductive effect of diabetes on the progesterone. The estrogen level did not show any significant difference in any of the groups.Conclusion: It is suggested that withania somnifera may have a regulatory effect on diabetes-induced change of the levels of gonadal-hormones, especially progesterone, in male rats. Nevertheless, somnifera is apparently only able to diminish FSH serum level in intact animals.  

Background: In spite of the great progress in assisted reproductive techniques ( ART), and although good quality embryos are transferred,  pregnancy rates have remained around 30%-35% due to low implantation rates.Objective: The aim of this study was to assess and compare the effects of administrating indomethacin or hyoscine suppositories prior to embryo transfer on the pregnancy rate in ART cycles.Materials and Methods: This double-blind clinical trial was performed in Vali-e-Asr Hospital as a pilot study from August 2005 through December 2006 on 66 infertile women in ART cycles. Controlled ovarian hyperstimulation was done using recombinant FSH (Gonal-F) with a long GnRH analogue protocol. After obtaining written consent, the subjects were randomly allocated into three equal groups (n=22). Groups A and B received indomethacin and hyoscine rectal suppositories, respectively 30 minutes before embryo transfer and group C was the control group. Data were analyzed by c2 , t-test, ANOVA, and Kruskall Wallis tests.Results: Overall pregnancy rate was 31% (n=21) with 13.6% (n=3) in  group A,  45.5% (n=10), and 36% (n=8) in groups B and C respectively, which shows that pregnancy rate is significantly higher in the group using hyoscine compared to  the other two groups (p=0.04). Uterine muscle cramps were experienced by 3 women (13.6%) in group C while none were reported by women in groups A or B, which shows a significant difference (p<0.04).Conclusion: It seems that compared to indomethacin, hyoscine administration 30 minutes prior to embryo transfer can significantly increase pregnancy rates by reducing uterine and cervical muscle spasm.

Background: Reviewing the literature, reveals that pentoxifylline (PTX) plus tocopherol (vitamin E) are used mainly to promote sperm quality. However trials focusing on the effects of these drugs in female partner are limited. Combination of pentoxifylline and vitamin E appeared to improve the pregnancy rate in patients with a thin endometrium by increasing the endometrial thickness and improving ovarian function.Objective: To determine whether combined PTX and tocopherol treatment can improve clinical pregnancy rate.Materials and Methods: One hundred twelve infertile women undergoing standardized controlled ovarian hyperstimulation for ICSI- ZIFT entered this randomized clinical trial. Patients were randomized to equal groups of combined PTX and tocopherol therapy or none (not receiving PTX and tocopherol).  These drugs were administered to the intervention group for two cycles before starting ICSI-ZIFT cycle. Main outcome measure was clinical pregnancy rate. SPSS.11 software (SPSS Inc. Chicago IL.) was used for data collection and analysis. Results: The clinical pregnancy was higher in the intervention (combined PTX and tocopherol) group in comparison to the other group (57.14% vs 39.29%, p=0.01). However, there was no difference in the mean endometrial thickness, number of retrieved oocytes, the number of metaphase II oocytes and grade of them in both groups.Conclusion: This study showed that PTX plus tocopherol could improve the ZIFT outcome in infertile couples. Local effects and anti oxidative characteristics of these drugs may be the cause of better results.

Background: The risk of multiple pregnancies, often present in programs of In Vitro Fertilization (IVF), is an important force for embryo cryopreservation. On the other hand, ethical restriction and assurance of potential fertility following chemo/radio therapy has led scientists to focus on female gamete preservation. Objective: Optimizing vitrification protocol by using less concentrated cryoprotectants (CPAs) in order to decrease CPAs toxicity.  Materials and Methods: Mouse Metaphase-II (M-II) oocytes and four cell-stage embryos were collected. Oocytes Survival, Fertilization and Developmental Rates (SRs, FRs, DRs) were recorded after cryotop-vitrification/warming. As well as comparing fresh oocytes and embryos, the data obtained from experimental groups (exp.) applying 1.25, 1.0, 0.75 molar (M) CPAs were analyzed in comparison to those of adopting 1.5 M CPAs [largely-used concentration of Ethylen Glycol (EG) and Dimethyl-sulphoxide (DMSO)].Results: The data of oocytes exposed to 1.25 M concentrated CPAs were in consistency with those exposed to 1.5 M and control group in terms of SR, FR and DR. As less concentration was applied, the more decreased SRs, FRs and DRs were obtained from other experimental groups. The results of embryos which were exposed to 1.25 M and 1.0 M were close to those vitrified with 1.5 M and fresh embryos. The results of 0.75 M concentrated CPAs solutions were significantly lower than those of control, 1.5 M and 1.0 M treated groups.Conclusion: CPAs limited reduction to 1.25 M and 1.0 M instead of using 1.5 M, for oocyte and embryo cryotop-vitrification procedure may be a slight adjustment.

Background: Mammalian oocytes are exposed to a mixture of many different growth factors and cytokines which provides an optimized microenvironment for oocyte maturation. In the lack of this natural microenvironment in vitro, the quality of oocyte and embryos appears to be suboptimal. Objective: This study was undertaken to investigate the effects of EGF and LIF on in vitro maturation, fertilization and cleavage rates in mouse oocytes.Materials and Methods: The GV oocytes were collected from female NMRI mice and randomly divided into control and 3 treatment groups. Oocytes in treatment groups were cultured in the maturation medium supplemented with 50 ng/ml rhLIF (Treatment 1), 10ng/ml EGF (Treatment 2) and 50 ng/ml LIF+ 10ng/ml EGF (Treatment 3) for 24 hours at 37°C in humidified 5% CO2 in air. The matured oocytes were fertilized in vitro and cultured for 96 hours. Finally, the developmental rates were assessed and embryos were stained using Hoechst 33258.Results: There was a higher maturation rate in treatment groups compared to the control group. There was not any significant difference in the rate of fertilization among the groups. The rates of cleavage (79.1%) and blastocyst formation (62.2%) were significantly higher in LIF + EGF group comparing to the other groups. The rates of hatching in groups treatment 1 (35.2%) and 3(41%) was significantly higher comparing to the other groups. Also the mean of total cell number in treatment groups significantly was higher than control (p< 0.05).  Conclusion: The findings of this study suggest a beneficial effect of LIF and EGF on mouse oocyte maturation and cleavage rates.