To evaluate the level of ribosomal RNA (rRNA) in cumulus cells (CCs) from women with polycystic ovary syndrome (PCOS) undergoing ICSI.
Materials and methods
The study population included three healthy oocyte donors (control) and three patients with PCOS. RNA expression in CCs was assessed using quantitative real-time PCR assay to measure the pre-rRNA transcripts (5′ETS region), 18 S, 5.8 S and 28 S rRNA.
The level of 18 S rRNA is 3.9 times higher (p = 0.036) and the level of 5.8 S rRNA is 2.9 times higher (p = 0.049) in CCs of PCOS patients than in CCs of healthy women. The fold change in expression of 28 S rRNA in CCs of PCOS patients also exceeds that in the control group, but did not reach a statistical significance (p = 0.342).
Our observations support the idea that CCs of PCOS patients contain comparatively more ribosomes that CCs of healthy oocyte donors that may indicate a higher proliferation rate or up-regulated translation of protein factors in ССs of PCOS patients.
Cumulus cells; rRNA; In vitro fertilization; Polycystic ovary syndrome
To detect expression of bone morphogenetic protein 15 (BMP15) and growth differentiation factor 9 (GDF9) in oocytes, and their receptor type 2 receptor for BMPs (BMPR2) in cumulus cells in women with polycystic ovary syndrome (PCOS) undergoing in vitro fertilization (IVF), and determine if BMPR2, BMP15, and GDF9 expression correlate with hyperandrogenism in FF of PCOS patients.
Prospective case–control study. Eighteen MII-oocytes and their respective cumulus cells were obtained from 18 patients with PCOS, and 48 MII-oocytes and cumulus cells (CCs) from 35 controls, both subjected to controlled ovarian hyperstimulation (COH), and follicular fluid (FF) was collected from small (10–14 mm) and large (>18 mm) follicles. RNeasy Micro Kit (Qiagen®) was used for RNA extraction and gene expression was quantified in each oocyte individually and in microdissected cumulus cells from cumulus-oocyte complexes retrieved from preovulatory follicles using qRT-PCR. Chemiluminescence and RIA assays were used for hormone assays.
BMP15 and GDF9 expression per oocyte was higher among women with PCOS than the control group. A positive correlation was found between BMPR2 transcripts and hyperandrogenism in FF of PCOS patients. Progesterone values in FF were lower in the PCOS group.
We inferred that BMP15 and GDF9 transcript levels increase in mature PCOS oocytes after COH, and might inhibit the progesterone secretion by follicular cells in PCOS follicles, preventing premature luteinization in cumulus cells. BMPR2 expression in PCOS cumulus cells might be regulated by androgens.
BMP15; GDF9; BMPR2; PCOS; COH; hyperandrogenism; mature oocyte
Several culture media are available to be used in ART. However it is uncertain whether embryos would preferably benefit from one type of medium or the association of different media.
We performed this study to evaluate the impact of simultaneous transfer of embryos independently cultured in two distinct culture media, on pregnancy outcome. A total of 722 couples who underwent infertility treatment were sequentially allocated into three groups: those who had half of the embryos individually cultured in MEM and the other half cultured in sequential media (MEM + Seq Group) (n = 243); those who had all embryos cultured only in sequential medium (Seq Group) (n = 239); and those who had all embryos cultured only in MEM (MEM Group) (n = 240).
The pregnancy rate was higher in the MEM + Seq group (51.8 %) than the Seq group (36.7 %) (p < 0.001). However the pregnancy rate observed in the MEM group was similar to the others (44.2 %). When a logistic regression test was applied it demonstrated that the number of transferred embryos did not interfere in the pregnancy rates.
Our results suggests that offering different culture conditions for sibling embryos with subsequent transfer of embryos that were kept in distinct culture media, might increase pregnancy rates in assisted reproduction cycles.
Culture media; Embryo development; Pregnancy rates
NANOG and OCT4 are required for the maintenance of pluripotency in embryonic stem cells (ESCs). These proteins are also expressed in the inner cell mass (ICM) of the mouse pre-implantation embryo.
Immunohistochemistry was used to show the presence of NANOG and OCT4 protein, and in situ hybridization was used to localize NANOG mRNA in human embryos from two-cell to blastocyst stage, and in human ESCs (hESCs).
Nanog and Oct4 were co-localized in human embryos from morula and blastocyst stages. NANOG mRNA was detected in a group of cells in the morula, in cells of the ICM of blastocysts, and evenly in hESCs. All non-differentiated hESCs expressed NANOG and OCT4 protein. Pluripotent cells expressing NANOG and Oct4 were eccentrically localized, probably in polarized cells in a human compacted morula, which appears to be different from expression in murine embryos.
In this study, we demonstrate that whole mount in situ hybridization is amenable to localization of mRNAs in human development, as in other species.
Pluripotency; Embryo; Embryonic stem cells; NANOG; In situ hybridization
To study the outcome of blastocysts showing expansion on day 5 and transferred on day 5 or 6, in comparison with those unexpanded and transferred on day 6.
Prospective cohort of 221 women prepared for BET classified into three groups according to timing of blastocyst expansion and day of embryo transfer. Group I; with expanded blastocysts on day 5 having day 5 transfer, group II; with expanded blastocysts on day 5 having day 6 transfer and group III ; with delayed expansion undergoing day 6 BET.
Implantation rates, pregnancy rates, ongoing pregnancy rates, and live birth rates in the first 2 groups were almost double the rates in the third group. The figures for implantation rates were 40 % in the first two groups vs. 19 % in the third group (P < 0.05). Pregnancy rates were 60.9 % and 64 % vs. 31.8 % (P < 0.05) and ongoing pregnancy/ live-birth rates were 52.3 % & 56 % vs. 27.3 %.
The current study reports better implantation and pregnancy rates with earlier expanding blastocysts regardless of the time of transfer.
Blastocyst expansion; Hatching; Blastocyst embryo transfer (BET)
To explore the pregnancy outcomes of embryo transfer with D2 or D3 embryos in patients with poor ovarian response.
The pregnancy outcomes of 620 patients who had poor ovarian response and underwent the first in vitro fertilization-embryo transfer (IVF-ET) were retrospectively analyzed. Of the 620 cycles, all available fresh D2 embryos were used in 365 cycles (day 2 embryo transfer) and all available fresh D3 embryos were used in 255 cycles (day 3 embryo transfer) without superfluous embryos for freezing.
There was a significant difference in clinical pregnancy rate between day 2 (32.73 %) and day 3 (50.83 %) embryo transfer in younger than 35-year-old patients, but no significant differences in implantation rate, live birth rate and spontaneous abortion rate (P > 0.05). There were similar pregnancy outcomes between day 2 and 3 embryo transfer in 35-year and older patients.
D3 embryo transfer may have better pregnancy outcomes in younger than 35-year-old patients with poor ovarian response.
Poor ovarian response; In vitro fertilization; Pregnancy outcomes; All available embryos
The aim of this study is to compare the secretory profiles and diagnostic power of anti-Mullerian hormone (AMH) for the PCOS patient with and without hyperandrogenism.
One hundred and thirty-one PCOS patients with oligomenorrhea or amenorrhea were recruited into the study. Sixty-two and sixty-nine patients had and did not have hyperandrogenism (HA+) hyperandrogenism (HA−), respectively. Sera were collected for determining the levels of AMH, basal sexual hormones, glucose and lipid metabolic indicators.
The AMH serum levels of PCOS patients were significantly higher than the control group, with the highest AMH serum level in the HA+ group. The cut-off value for predicting PCOS patients of all types was 3.92 ng/mL, with a sensitivity of 65 %, and specificity of 62 %. The cut-off value for predicting PCOS patients in the HA+ group was 4.23 ng/mL, with a sensitivity of 82 %, and specificity of 64 %. The cut-off value for predicting PCOS patients in the HA− group was 3.76 ng/mL, with a sensitivity of 64 %, and specificity of 62 %. In the HA+ group, AMH was negatively associated with FSH and positively associated with LH. In the HA− group, AMH was negatively associated with HDL and positively associated with BMI, fasting glucose and LDL.
AMH is only suitable for predicting the PCOS patients with hyperandrogenism. The diagnostic power of AMH is limited when used to predict patients without hyperandrogenism. It reflects the differences in pathophysiology and severity of disrupted folliculogenesis between the two subtypes.
Anti-Mullerian hormone; Polycystic ovary syndrome; Hyperandrogenism; Folliculogenesis
Embryos diagnosed as abnormal in Preimplantation Genetic Diagnosis (PGD) cycles are useful for the establishment of human Embryonic Stem Cells (hESC) lines with genetic disorders. These lines can be helpful for drug screening and for the development of new treatments. Vitrification has proved to be an efficient method to preserve human blastocysts. One hundred and three abnormal or undiagnosed vitrified blastocysts from the PGD programme at Institut Universitari Dexeus were donated for human embryonic stem cell derivation. The overall survival rate after warming was 70.6 %. Our results showed better survival rates when blastocysts have not started the hatching process (initial/expanded 87.8 %, hatching 68.3 % and hatched 27.3 %). Thirty-five blastocysts and 12 partially surviving embryos were seeded. One hESC line with the multiple exostoses type 2 paternal mutation was obtained.
Blastocyst; Vitrification; PGD; hESC derivation
The aim of our study was to ascertain the influence of hCG levels at oocyte pick-up on IVF outcomes, and their relationship with clinical parameters.
A prospective study was performed including 473 women undergoing IVF, aged under 40 years. Blood samples to analyze hCG levels were obtained at the time of follicular aspiration, 36 h after the administration of 250 μg of recombinant hCG.
Neither the numbers of oocytes obtained or fertilized, nor the pregnancy rate, were correlated with hCG levels. Moreover, hCG values were very similar in women who did and did not become pregnant (123.3 ± 48.7 and 117.5 ± 44.7 mUI/mL). Cases in which no oocytes were recovered after follicular aspiration had similar hCG levels to those in which more than 1 oocyte was obtained. On the other hand, hCG levels were negatively related to body mass index, weight, and age.
These data indicate that after the administration of 250 μg of recombinant hCG, hCG levels are not responsible for failure to recover oocytes. Specifically, there was no correlation between plasma hCG levels and the number of oocytes obtained or other markers of IVF outcome. There was, however, an inverse relationship with BMI, body weight and age.
Human chorionic gonadotropin; Oocytes; IVF; Body mass index; Pregnancy rate
To investigate the correlation of endocrine gland-derived vascular endothelial growth factor (EG-VEGF), vascular endothelial growth factor (VEGF) and transforming growth factor beta 1 (TGF-β1) with the corresponding reproductive outcome in patients who received in vitro fertilization-embryo transfer (IVF-ET).
Sixty-seven women undergoing IVF-ET at a university tertiary hospital were recruited for a prospective study. Concentrations of EG-VEGF, VEGF and TGF-β1 were measured by enzyme-linked immunosorbent assay (ELISA) in follicular fluid (FF) collected during oocyte retrieval (OR) and in serum collected 2 days after OR.
In FF, concentrations of both EG-VEGF and VEGF were negatively correlated with peak E2 and the number of MII oocytes retrieved, and positively correlated with each other. In serum, concentrations of all the three growth factors were positively correlated with the rate of good quality embryo, and with one another. Patients in the pregnancy group had lower peak E2 concentrations and higher serum EG-VEGF concentrations than those in the non-pregnancy group, but such tendency was not observed in the case of VEGF and TGF-β1.
Both concentrations of EG-VEGF and VEGF in FF were negatively correlated with ovarian response and oocyte maturation. Concentrations of all the three growth factors in serum were positively correlated with embryo quality, but only serum concentrations of EG-VEGF were associated with the pregnancy outcome.
IVF-ET; EG-VEGF; VEGF; TGF-β1; Pregnancy
Clinical application of human embryonic stem cells will be possible, when cell lines are created under xeno-free and defined conditions. We aimed to establish methodologies for parthenogenetic activation, culture to blastocyst and mechanical isolation of the inner cell mass (ICM) using bovine oocytes, as a model for derivation and proliferation of human embryonic stem cells under defined xeno-free culture conditions.
Cumulus-oocyte-complexes were in vitro matured and activated using Ca2+Ionophore and 6-DMAP or in vitro fertilized (IVF). Parthenotes and biparental embryos were cultured to blastocysts, when their ICM was mechanically isolated and placed onto a substrate of fibronectin in StemPro® medium. After attachment, primary colonies were left to proliferate and stained for pluripotency markers, alkaline phosphatase and Oct-4.
Parthenogenesis and fertilization presented significantly different success rates (91 and 79 %, respectively) and blastocyst formation (40 and 43 %, respectively). ICMs from parthenogenetic and IVF embryos formed primary and expanded colonies at similar rates (39 % and 33 %, respectively). Six out of eight parthenogenetic colonies tested positive for alkaline phosphatase. Three colonies were analyzed for Oct-4 and they all tested positive for this pluripotency marker.
Our data show that Ca2+ Ionophore, and 6-DMAP are efficient in creating large numbers of blastocysts to be employed as a model for human oocyte activation and embryo development. After mechanical isolation, parthenogetic derived ICMs showed a good rate of derivation in fibronectin and Stem-Pro forming primary and expanded colonies of putative embryonic stem cells. This methodology may be a good strategy for parthenogenetic activation of discarded human oocytes and derivation in defined conditions for future therapeutic interventions.
Parthenogenesis; Embryonic stem cells; Defined conditions
Presently the techniques for making transgenic animals are cumbersome, required costly instruments and trained man-power. The ability of spermatogonial stem cells (SSCs) to integrate foreign genes has provided the opportunity for developing alternate methods for generation of transgenic animals. One of the big challenges in this field is development of the methods to identify and purify donor SSCs by antibody mediated cell sorting.
The present study was aimed to identify goat subpopulations of SSCs using polyclonal antibodies against PGP9.5 and c-kit molecular markers as well as the growth characteristics of SSCs during short term culture.
One month old goats’ testicular samples were subjected for immunohistochemical and immunocytochemical evaluations. The enzymatically isolated SSCs were cultured in DMEM plus FCS supplemented with (treatment) or without (control) growth factors (GDNF, LIF, FGF, and EGF) for 2 weeks. At the end of culture the morphological characteristics of SSCs colonies and immunocytochemical staining were evaluated.
The number and size of colonies in treatment groups were significantly (P < 0.01) higher than corresponding values in controls. The presence of PGP 9.5 and c-kit antigens was confirmed in immunocytochemical evaluation. In immunocytochemical evaluation, the proportion of c-kit and PGP9.5 positive cells were significantly (P < 0.001) higher in control and treatment groups, respectively.
The presence of PGP9.5 and c-kit antigens was confirmed in goat SSCs. Moreover, culture medium supplementation with growth factors could effectively retain the undifferentiation status of SSCs, reflected as a higher population of PGP9.5 positive cells, after short term culture.
PGP9.5; c-kit; Goat; Spermatogonia; Growth factors
To compare the efficacy of intrafollicular sperm injection (IFI) versus intrauterine insemination (IUI) in the treatment of subfertility.
38 couples suffering primary or secondary subfertility contributed a total of 47 IUI or IFI cycles, 26 by IUI and 21 by IFI. Folliculogenesis, ovulation triggering, and IUI or IFI were performed. Motile spermatozoa were inseminated into the uterine cavity for IUI or injected into pre-ovulatory follicles for IFI. The rate of biochemical and clinical pregnancy was assessed.
The rate of biochemical pregnancy/cycle for IUI was 11 % as compared to 38 % for IFI (p = 0.04). The rate of clinical pregnancy/cycle for IUI was 11 % as compared to 29 % for IFI (p = 0.26). The rate of twin pregnancy and miscarriage was low and no high order multiple gestation was observed. The rate of ectopic tubal pregnancy/cycle for IUI was 0 % as compared to 9 % for IFI (p = 0.19); no ovarian pregnancy was observed. When the analysis was confined to IFI cycles in which 2.68-6.65 million motile spermatozoa were injected/follicle (n = 10), a rate of 60 % clinical pregnancy/cycle was observed, of which 2 were ectopic.
Under the conditions described herein, IFI was more effective than IUI at achieving pregnancy.
Intrafollicular sperm injection; Intrauterine insemination
To investigate whether embryo shape is a useful morphologic predictor of developmental competence in IVF cycles.
Two hundred eighteen day 3 single embryo transfer (SET) cycles and 225 day 3 double embryo transfer (DET) cycles in which only 8-cell non-fragmented embryos with symmetric blastomeres were transferred and in which the developmental fate of each embryo was known were analyzed for IVF outcomes with respect to embryo shape. Embryo shape was quantitatively calculated after digitizing embryo images using MATLAB, where a score of 1.0 represented a perfectly circular embryo.
The SET data did not reveal a significant impact of embryo shape on embryo developmental fate. The DET data revealed a trend toward the best outcomes in cycles where both embryos exhibited “roundness” scores in the highest tertiles (T3) for embryo shape. However only one subgroup (T2/T1—one embryo in the middle shape tertile (T2) and one in the lowest shape tertile (T1)) was associated with significantly lower odds of live-birth as compared to the referent group (T3/T3). When SET and DET data were combined, embryo shape was not found to be a predictor of IVF outcome.
Based on this retrospective analysis, the weak association of day 3 embryo shape with implantation potential suggests that this morphological characteristic is unlikely to be a useful additional marker for embryo selection after cell number, fragmentation, and blastomere symmetry. Further studies are planned to assess applicability of these conclusions to embryos of varying stages and grades.
IVF; Embryo morphology; Day 3 embryo shape; Implantation
We investigated the activities and relevance of a validated panel of antioxidant enzymes, cytokines, specific lipid peroxidation end products and six fatty acids by correlational analyses with peak E2 levels and pregnancy outcome after ovarian stimulation for IVF or IUI.
Blood samples obtained from 15 patients undergoing ovarian stimulation with rFSH or hMG were divided into two groups. Group-1 was baseline blood collected on day-2-3 of women cycle. Group-2 is blood collected at the end of FSH/hMG injection. Serum was collected and stored in liquid nitrogen at -196 °C until analysis. Standard IVF and IUI procedures were followed. The serum levels of Paraoxonase (PON1), Superoxide Dismutases (SOD), Interleukin-6 (IL-6), Glutathione Peroxidase (GPx), 8-Isoprostane, and fatty acids Arachidic, Palmitic, Stearic, Oleic, Linoleic & Linolenic were measured.
With the exception of 8-Isoprostane, results showed a positive correlation between baseline and peak levels of E2 and that of SOD, GPx, PON1, and IL-6. The PON1, IL-6 and SOD were significantly (p < 0.05) higher in pregnant than non-pregnant group. Fatty acid levels at baseline and peak E2 were not different but pregnancy rates were found to be decreasing with higher palmitic, and stearic acid levels.
Ovarian stimulation causes a significant increase in serum PON1, SOD, GPx and IL-6 activity in women undergoing IVF or IUI. The high levels of IL-6, SOD, and PON1 and lower levels of palmitic, and stearic acids in the pregnancy positive group indicate that these oxidative stress and nutritional factors may be used as a predictive marker in controlled ovarian stimulation success.
Oxidative stress; Ovarian stimulation; IVF; IUI; Paraoxonase; Superoxide Dismutases; Interleukin-6; Glutathione Peroxidase; 8-Isoprostane; Fatty acids; Arachidic; Palmitic; Stearic; Oleic; Linoleic & Linolenic
Kisspeptins (Kps), were first found to regulate the hypothalamopituitary-gonadal axis (HPG) axis in 2003, when two groups-demonstrated that mutations of GPR54 causes idiopathic hypogonadotropic hypogonadism (IHH) characterized by delayed puberty. Objective of this review is to highlight both animal and human discoveries in KISS1/GPR54 system in last decade and extrapolate the therapeutic potential in humans from till date human studies.
A systematic review of international scientific literature by a search of PUBMED and the authors files was done for Kp in reproduction, metabolic control & signal transduction.
Patient(s): In human studies—normal subjects patients with HH, or HA.
Main outcome measures: Effects of Kp on puberty, brain sexual maturation, regulation of GnRH secretion, metabolic control of GnRH Neurons (N).
Kps/GPR54 are critical for brain sexual maturation, puberty and regulation of reproduction. Kps have been implicated in mediating signals to GnRH N—positive and negative feedback, metabolic input. Ability of Kp neurons to coordinate signals impinging on the HPG axis makes it one of most important regulators of reproductive axis since GnRH N’s lack many receptors, with Kp neurons serving as upstream modulators.
Kps have proven as pivotal regulators of the reproduction, with the ability to integrate signals from both internal and external sources. Knowledge about signaling mechanisms involved in Kp stimulation of GnRH and with human studies has made it possible that therapeutically available Kp agonists/antagonists may be used for treatment of delayed puberty/HH, Hypothalamic amenorrhea and in prevention of spread of malignant ovarian/gonadal malignancies along with uses in some eating disorders.
Kisspeptins; KISS1 receptor; Idiopathic hypogonadotropic hypogonadism; Puberty initiation; Sexual maturation control; Negative feedback control; Positive feedback control; Metabolic control of reproduction
To clarify if birefringent structures of human oocytes and embryos, measurable by polarized light microscopy, have any value in predicting the chance of pregnancy in human in vitro fertilization and may halp to identify the most competent oocytes and embryos.
The inner layer of the zona pellucida (IL-ZP) and the meiotic spindle (MS) were analyzed by polarized light microscopy in 258 oocytes and in the 209 embryos deriving from them. Data obtained from 102 ICSI cycles with conception were compared with those obtained in 156 cycles without conception. The retardance and area of the IL-ZP, as well as the retardance, length of the major axis, and area of the MS were measured. Furthermore, polarized light microscopy parameters were related to the embryo morphological score by multiple regression analysis.
The mean area of the IL-ZP of both oocytes and embryos was significantly lower in conception than in non-conception cycles (p = 0.0001 for oocytes and p = 0.002 for embryos). The area of the IL-ZP in embryos was significantly, inversely related to the embryo morphological score (p = 0.011). The area, the major axis length and the retarcance of the MS, as well as the retardance of the IL-ZP in oocytes and embryos were comparable in conception and non-conception cycles.
The area of the IL-ZP of the human oocytes may represent a marker of oocyte competence, as oocytes with a low IL-ZP area are more frequently obtained in conception cycles. When measured in embryos, a low IL-ZP area identifies embryos with a high chance of implantation.
Polarized light microscopy; Zona pellucida; Meiotic spindle; Pregnancy; IVF
Our objective was to identify a marker for oocyte aneuploidy in follicular fluid (FF) in women with an increased risk of oocyte aneuploidy after controlled ovarian hyperstimulation.
Materials and methods
Three groups of oocytes were constituted for polar body screening by FISH (chromosomes 13, 16, 18, 21 and 22): Group 1, advanced maternal age (n = 156); Group 2, implantation failure (i.e. no pregnancy after the transfer of more than 10 embryos; n = 101) and Group 3, implantation failure and advanced maternal age (n = 56). FSH and other proteins were assayed in the corresponding FF samples.
Of the 313 oocytes assessed, 35.78 % were abnormal. We found a significant difference between the follicular FSH levels in normal oocytes and abnormal oocytes (4.85 ± 1.75 IU/L vs. 5.41 ± 2.47 IU/L, respectively; p = 0.021). We found that the greater the number of chromosomal abnormalities per oocyte (between 0 and 3), the higher the follicular FSH level.
High FF FSH levels were associated with oocyte aneuploidy in women having undergone controlled ovarian hyperstimulation.
Oocyte; Polar body; FISH; Aneuploidy; FSH
The aim of this study was to evaluate the impact of vitrification on mitochondrial membrane potential (ΔΨm) in human metaphase II (MII) oocytes, and the changes of ΔΨm on thawed MII oocytes.
MII oocytes were obtained from clinical IVF cycles when the oocytes were failed to fertilization within 24 h after insemination. All oocytes were randomly divided into 4 groups: non-frozen (fresh group), cultured for 0 h (0 h group), 2 h (2 h group) and 4 h (4 h group) after vitrification/thawing. All oocytes were stained with the ΔΨm-specific probe JC-1 and detected by laser scanning confocal microscope (LSCM) for mitochondrial analysis.
The ΔΨm of oocytes was significantly decreased in 0 h and 2 h groups when compared with fresh group (0.93, 1.09 vs 1.34, P < 0.05), but similar between 4 h group and fresh group (1.30 vs 1.34, P > 0.05).
In the vitrification/thawing process, the ΔΨm of MII oocytes could have temporally dynamic changes within 2 h after thawing but would be fully recovered after 4 h culture.
Vitrification; Human metaphase II oocyte; Mitochondrial membrane potential
This study was designed to determine the combined effects of adding source of n-3 fatty acids (FA) and α-tocopherol (vitamin E, VE) to semen extender on freezability and FA composition of Brown Swiss bull sperm.
Semen samples were collected from 6 Brown Swiss bulls and pooled. In the first trial, semen was divided into 12 groups including 4 levels of n-3 FA (0, 1, 10, 100 ng ml−1) and 3 levels of VE (0. 0.2, 0.4 mM). Motility, viability and fatty acid composition of sperm were measured.
The treatment of 10 ng ml−1 n-3 FA and 0.4 mM VE had the best post-thaw sperm characteristics (P < 0.01). In the second trial, sperm lipid composition of this treatment and control (without FA and VE) was determined. Supplementing n-3 fatty acids during cryopreservation increased docosahexaenoic acid (DHA) and the ratio of n-3 to n-6 FA in sperm before freezing and after thawing.
The results suggest that combining the optimal level of n-3 FA (10 ng ml−1) with the highest level of VE tested (0.4 mM) in a semen extender changed the membrane lipid composition and improved freezablity of Brown Swiss bull sperm.
Bull; Semen; n-3 fatty acid; Vitamin E; Cryopreservation
There have been many studies concerning the associations of angiotensin-converting enzyme (ACE) I/D, angiotensinogen (AGT) M235T polymorphisms with pregnancy induced hypertension (PIH) among Chinese populations. However, the results were inconsistent, prompting the necessity of meta-analysis.
Studies published in English and Chinese were mainly searched in EMbase, PubMed and CBM up to January 2012.
Twenty-three studies with 3,551 subjects for ACE I/D and seven studies with 1,296 subjects for AGT M235T were included. Significant associations were found between ACE I/D and PIH under dominant, recessive and allelic models. A separate analysis confined to preeclampsia suggested that ACE I/D was associated with preeclampsia under recessive model and allelic model, but not dominant model. Stratified analyses were conducted as meta-regression analysis indicated that the sample size of case group was a significant source of heterogeneity, which suggested no significant association between ACE I/D and PIH in the subgroup of more than 100 cases. Associations were found between AGT M235T and PIH under dominant genetic model (OR = 1.59; 95 %CI: 1.04–2.42), recessive genetic model (OR = 1.60; 95 %CI: 1.07–2.40), and allelic model (OR = 1.40; 95 %CI: 1.17–1.68). No publication bias was found in either meta-analysis.
The present meta-analysis suggested significant associations between ACE I/D, AGT M235T and PIH in Chinese populations. However, no significant association was found between ACE I/D and PIH in the subgroup of more than 100 cases. Studies with larger sample sizes are necessary to investigate the associations between gene polymorphisms and PIH in Chinese populations.
Angiotensin-converting enzyme (ACE); Angiotensinogen (AGT); Meta-analysis; Polymorphism; Pregnancy induced hypertension (PIH)