Category Archives: Human Reproduction

BACKGROUND

Interleukin 33 (IL-33) is a cytokine involved in fibrotic disorders. We have analyzed IL-33 levels in the sera and peritoneal fluids of women with various forms of endometriosis and investigated the correlation with disease activity.

METHODS

We conducted a prospective laboratory study in a tertiary-care university hospital between January 2005 and December 2010. Five hundred and ten women with histologically proven endometriosis and 132 endometriosis-free controls were enrolled in this study. Complete surgical exploration of the abdominopelvic cavity was performed in each patient. Blood samples and peritoneal fluids were obtained before and during surgical procedures, respectively. IL-33 was measured by an enzyme-linked immunosorbent assay in sera and peritoneal fluids, and the concentrations correlated with the extent and the severity of endometriotic lesions.

RESULTS

IL-33 was detectable in 23.1% of serum samples from all 642 women studied and 75.0% of peritoneal fluid samples studied (44 women with endometriosis and 36 controls). Serum IL-33 was higher in deeply infiltrating endometriosis (DIE) (median, 104.9 pg/ml; range, 8.0–104.9) than in endometriosis-free women (median, 61.3 pg/ml; range, 7.5–526.0; P = 0.022) or in women affected by superficial endometriosis (median, 36.8 pg/ml; range, 7.5–179.0; P < 0.001). Peritoneal IL-33 was higher in DIE than in endometriosis-free women (median, 642.0 pg/ml; range, 25.9–3350.6 versus median, 194.2 pg/ml; range, 12.7–1818.2, respectively; P = 0.003). We found positive correlations between serum IL-33 concentration and intensity of dysmenorrhea (r = 0.174; P = 0.028) and gastrointestinal symptoms (r = 0.199; P = 0.027), total number of DIE lesions (r = 0.224; P = 0.016) and the worst DIE lesion (r = 0.299; P < 0.001).

CONCLUSIONS

In spite of the number of samples with undetectable levels, serum IL-33 is abnormally elevated in women with endometriosis and principally in DIE. Elevated serum IL-33 is correlated with the intensity of preoperative painful symptoms, and with the extent and severity of the DIE. IL-33 may be considered as a novel cytokine involved in the pathogenesis of DIE.

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BACKGROUND

Intrauterine devices (IUDs) have been studied for use for emergency contraception for at least 35 years. IUDs are safe and highly effective for emergency contraception and regular contraception, and are extremely cost-effective as an ongoing method. The objective of this study was to evaluate the existing data to estimate the efficacy of IUDs for emergency contraception.

METHODS

The reference list for this study was generated from hand searching the reference lists of relevant articles and our own article archives, and electronic searches of several databases: Medline, Global Health, Clinicaltrials.gov, Popline, Wanfang Data (Chinese) and Weipu Data (Chinese). We included studies published in English or Chinese, with a defined population of women who presented for emergency contraception and were provided with an IUD, and in which the number of pregnancies was ascertained and loss to follow-up was clearly defined. Data from each article were abstracted independently by two reviewers.

RESULTS

The 42 studies (of 274 retrieved) that met our inclusion criteria were conducted in six countries between 1979 and 2011 and included eight different types of IUD and 7034 women. The maximum timeframe from intercourse to insertion of the IUD ranged from 2 days to 10 or more days; the majority of insertions (74% of studies) occurred within 5 days of intercourse. The pregnancy rate (excluding one outlier study) was 0.09%.

CONCLUSIONS

IUDs are a highly effective method of contraception after unprotected intercourse. Because they are safe for the majority of women, highly effective and cost-effective when left in place as ongoing contraception, whenever clinically feasible IUDs should be included in the range of emergency contraception options offered to patients presenting after unprotected intercourse. This review is limited by the fact that the original studies did not provide sufficient data on the delay between intercourse and insertion of the IUD, parity, cycle day of intercourse or IUD type to allow analysis by any of these variables.

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BACKGROUND

The role of the plasminogen-plasmin (PLG-PLA) system in fertilization is unknown, although its dysfunction has been associated with subfertility in humans. We have recently detected and quantified plasminogen in the oviductal fluid of two mammals and showed a reduction in sperm penetration during IVF when plasminogen is present. The objective of this study was to describe the mechanism by which PLG-PLA system regulates sperm entry into the oocyte.

METHODS AND RESULTS

By combining biochemical, functional, electron microscopic, immunocytochemical and live cell imaging methods, we show here that (i) plasminogen is activated into the protease plasmin, by gamete interaction; (ii) urokinase-type and tissue-type plasminogen activators are present in oocytes, but they are not of cortical granule origin; (iii) sperm binding to oocytes triggers the releasing of plasminogen activators and (iv) the generated plasmin causes sperm detachment from the zona pellucida.

CONCLUSIONS

Our results describe a novel mechanism for the success or failure of fertilization in mammals, by which molecules present in the oviductal environment are activated by molecules originating within the gametes. We anticipate that therapeutic up- or down-regulation of this physiological mechanism may be used to help in conception or as a contraceptive tool. Since components of the PLG-PLA system are already available as drugs for heart attacks or cancer therapies, basic research on this novel function would be rapidly transferable for clinical application.

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BACKGROUND

Despite the success of ICSI, total fertilization failure (TFF) still occurs in 1–3% of all ICSI cycles. ICSI followed by assisted oocyte activation (ICSI-AOA) can restore fertilization, most efficiently in cases of sperm-related fertilization deficiency. The indication for ICSI-AOA is less obvious when the capacity of the sperm to activate oocytes is considered normal, as proved by a heterologous ICSI model, such as the mouse oocyte activation test (MOAT). In this study, we verified whether ICSI-AOA is beneficial for patients in whom an oocyte-related activation deficiency is suspected.

METHODS

A prospective study was conducted including patients presenting with a history of TFF or low fertilization (LF) following conventional ICSI in our centre (in-house cases, n= 2) or elsewhere (out-house cases, n= 12). In all cases a sperm deficiency was refuted by the MOAT. In a next treatment cycle, ICSI-AOA was performed on half of the sibling metaphase II oocytes and conventional ICSI on the rest (‘split ICSI-AOA cycle’). The main outcome parameters were fertilization, pregnancy and live birth rates.

RESULTS

Overall, ICSI-AOA was able to improve fertilization rates in couples with a suspected oocyte-related fertilization problem, with a mean fertilization rate of 74.2% following ICSI-AOA compared with 43.5% following conventional ICSI (P< 0.001). Cumulative pregnancy rate and live birth rate per cycle were 35.7 and 14.3%, respectively. Considering the out-house patients only, fertilization rates with ICSI-AOA were higher in couples with previous TFF than with conventional ICSI (P< 0.001). Interestingly, for out-house patients who had experienced low, but not zero, fertilization elsewhere, ICSI-AOA could not enhance the fertilization rate. For the two in-house patients, both suffering from previous LF following conventional ICSI, the ICSI-AOA procedure enhanced the mean fertilization rate (25 versus 75%, respectively).

CONCLUSIONS

For patients with a suspected oocyte-related activation deficiency, as diagnosed by a heterologuous ICSI model, the indication for ICSI-AOA still remains debatable. Our data show that ICSI-AOA is very efficient in patients with a suspected oocyte-related activation deficiency and previous TFF after conventional ICSI. In contrast, when there was a history of LF in another centre, one should be careful and test the efficiency of ICSI-AOA on half of the sibling oocytes, because ICSI-AOA is not always beneficial for patients with previous LF and a suspected oocyte-related activation deficiency. For these patients, a split ICSI-AOA cycle using sibling oocytes can help to distinguish between a molecular oocyte-related activation deficiency and a previous technical or other biological failure. Moreover, this split ICSI-AOA strategy enables us to set the appropriate strategy for future treatment cycles. Further research with larger groups of patients is now required.

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http://humrep.oxfordjournals.org/rss/current.xml

BACKGROUND

We have previously shown that the medium used for culturing IVF embryos affects the birthweight of the resulting newborns. This observation with potentially far-reaching clinical consequences during later life, was made in singletons conceived during the first IVF treatment cycle after the transfer of fresh embryos. In the present study, we hypothesize that in vitro culture of embryos during the first few days of preimplantation development affects perinatal outcome, not only in singletons conceived in all rank order cycles but also in twins and in children born after transfer of frozen embryos. Furthermore, we investigated the effect of culture medium on gestational age (GA) at birth.

METHODS

Oocytes and embryos from consecutive treatment cycles were alternately assigned to culture in either medium from Vitrolife or from Cook. Data on a cohort of 294 live born singletons conceived after fresh transfer during any of a patient's IVF treatment cycles, as well as data of 67 singletons conceived after frozen embryo transfer (FET) and of 88 children of 44 twin pregnancies after fresh transfer were analysed by means of multiple linear regression.

RESULTS

In vitro culture in medium from Cook resulted in singletons after fresh transfer with a lower mean birthweight (adjusted mean difference, 112 g, P= 0.03), and in more singletons with low birthweight (LBW) <2500 g (P= 0.006) and LBW for GA ≥37 weeks (P= 0.015), when compared with singletons born after culture in medium from Vitrolife AB. GA at birth was not related to the medium used (adjusted difference, 0.05 weeks, P = 0.83). Among twins in the Cook group, higher inter-twin mean birthweight disparity and birthweight discordance were found. Z-scores after FET were –0.04 (±0.14) in the Cook group compared with 0.18 (±0.21) in the Vitrolife group (P> 0.05).

CONCLUSIONS

Our findings support our hypothesis that culture medium influences perinatal outcome of IVF singletons and twins. A similar trend is seen in case of singletons born after FET. GA was not affected by culture medium. These results indicate that in vitro culture might be an important factor explaining the poorer perinatal outcome after assisted reproduction technology (ART). Further research is needed to confirm this culture medium-induced effect in humans and to provide more insight into whether it is caused by epigenetic disturbance of imprinted genes in fetal or placental tissues. Moreover, embryo culture media and their effects need to be investigated thoroughly to select the best embryo culture medium in order to minimize or prevent short-term risks and maybe even long-term disease susceptibility.

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BACKGROUND

Our previous studies have demonstrated that cyclosporin A (CsA) can increase the cell number in and invasion by human first-trimester trophoblasts and induce maternal–fetal tolerance. C-X-C chemokine receptor type 4 (CXCR4) and C-X-C chemokine ligand 12 (CXCL12) are important mediators at the maternal–fetal interface during early pregnancy. In this study, we further investigate the molecular mechanisms underlying modulation by CsA of the crosstalk between human cytotrophoblast and decidual stromal cell (DSC).

METHODS

Human first-trimester cytotropoblast and DSC were treated with CsA in the absence or presence of U0126 pretreatment, and then the mRNA and protein levels of CXCL12 and CXCR4 were measured by RT–PCR, qPCR, in-cell western blots and enzyme-linked immunosorbent assay (ELISA), respectively. 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide and Matrigel invasion assays were used to determine the invasiveness of cytotrophoblast, respectively. The activity of matrix metalloproteinase (MMP)-9 and MMP-2 was detected by gelatin zymography. A co-culture with direct contact between cytotrophoblast and DSC was established and used to investigate the interaction between these two cells.

RESULTS

CsA up-regulated CXCL12 and CXCR4 expression in human first-trimester cytotrophoblast cells, but not in DSCs. Blocking the mitogen-activated proteinkinase/extracellular signal-regulated kinase (MAPK/ERK1/2) signaling by U0126 abrogated the CsA-induced increase in CXCL12 and CXCR4 expression and neutralizing antibodies to CXCL12 or CXCR4 completely inhibited the CsA-induced increase in cell number, invasion and MMP-9 and MMP-2 activity of cytotrophoblast. CsA also significantly promoted the activity of MMP-9 and MMP-2 in DSCs, but this was unaffected by CXCL12 or CXCR4 neutralizing antibody. Furthermore, the CsA-induced MMP-9 and MMP-2 activity and the invasiveness of cytotrophoblast in the cytotrophoblast and DSC co-culture were significantly increased compared with CsA-treated trophoblast cultured alone, and CXCR4 blocking antibody effectively abolished the increased MMP activity and invasion of cytotrophoblasts in the cytotrophoblast-DSC co-culture stimulated by CsA.

CONCLUSIONS

CsA can promote the crosstalk between cytotrophoblast and DSC through up-regulating CXCL12/CXCR4 interaction via MAPK signaling, resulting in the increased numbers of and invasion by human cytotrophoblast cells.

Source:
http://humrep.oxfordjournals.org/rss/current.xml