[Comparison between two analgesic protocols on IVF success rates]

OBJECTIVES

Analgesic protocols administered before a follicular puncture under local anesthesia are well tolerated when using NSAIDs, but we still do not know their possible impacts on in vitro fertilization (IVF) outcomes.

MATERIAL AND METHODS

A retrospective monocentric study using two consecutive temporal cohorts of patients was conducted to compare two analgesic protocols: paracetamol/alprazolam (P/A), then nefopam/ketoprofen (N/K).

RESULTS

We demonstrated that biochemical pregnancy rate and the others outcomes of IVF are not significantly influenced by the type of analgesic protocol used.

CONCLUSION

The protocol N/K enhances patient comfort without jeopardizing the IVF success rates.

[Male infertility due to azoospermia and in vitro fertilization assisted by ICSI. Findings based on a prospective study of our first 42 patients]

INTRODUCTION

Our experience of ICSI began in 1997. This study reviews our four-year experience based on 42 consecutive couples.

MATERIAL AND METHOD

Between February 1997 and December 2000, 42 sterile couples due to male infertility were treated by ICSI. Surgical exploration and "open" gamete collection were proposed regardless of the predefined type of azoospermia, obstructive or non-obstructive.

RESULT

Seventy one cycles were performed: ICSI used epididymal spermatozoa in 49 cycles, and testicular spermatozoa in 22 cycles. The fertilization rate was 76% for fresh semen and 87% for frozen semen. The fertilization rate was 88% for epididymal spermatozoa and 68% for testicular spermatozoa. 13 pregnancies were obtained (18.3%), 11 babies were born at term including 3 twin pregnancies. No significant difference was observed between fresh and frozen semen, or between obstructive and non-obstructive azoospermia.

CONCLUSION

IVF-ICSI applied to sterility due to male infertility has revolutionized the management of sterile couples. However, as for any new procedure in medicine, we must be vigilant, as a sufficient follow-up is necessary to definitively evaluate the safety of ICSI, especially in terms of the risk of genetic abnormalities.

Tim23 links the inner and outer mitochondrial membranes

Tim23, a key component of the mitochondrial preprotein translocase, is anchored in the inner membrane by its C-terminal domain and exposes an intermediate domain in the intermembrane space that functions as a presequence receptor. We show that the N-terminal domain of Tim23 is exposed on the surface of the outer membrane. The two-membrane-spanning topology of Tim23 is a novel characteristic in membrane biology. By the simultaneous integration into two membranes, Tim23 forms contacts between the outer and inner mitochondrial membranes. Tethering the inner membrane translocase to the outer membrane facilitates the transfer of precursor proteins from the TOM complex to the TIM23 complex and increases the efficiency of protein import.

The yeast trimeric guanine nucleotide-binding protein alpha subunit, Gpa2p, controls the meiosis-specific kinase Ime2p activity in response to nutrients

Saccharomyces cerevisiae Gpa2p, the alpha subunit of a heterotrimeric guanine nucleotide-binding protein (G protein), is involved in the regulation of vegetative growth and pseudohyphal development. Here we report that Gpa2p also controls sporulation by interacting with the regulatory domain of Ime2p (Sme1p), a protein kinase essential for entrance of meiosis and sporulation. Protein-protein interactions between Gpa2p and Ime2p depend on the GTP-bound state of Gpa2p and correlate with down-regulation of Ime2p kinase activity in vitro. Overexpression of Ime2p inhibits pseudohyphal development and enables diploid cells to sporulate even in the presence of glucose or nitrogen. In contrast, overexpression of Gpa2p in cells simultaneously overproducing Ime2p results in a drastic reduction of sporulation efficiency, demonstrating an inhibitory effect of Gpa2p on Ime2p function. Furthermore, deletion of GPA2 accelerates sporulation on low-nitrogen medium. These observations are consistent with the following model. In glucose-containing medium, diploid cells do not sporulate because Ime2p is inactive or expressed at low levels. Upon starvation, expression of Gpa2p and Ime2p is induced but sporulation is prevented as long as nitrogen is present in the medium. The negative control of Ime2p kinase activity is exerted at least in part through the activated form of Gpa2p and is released as soon as nutrients are exhausted. This model attributes a switch function to Gpa2p in the meiosis-pseudohyphal growth decision.

Anti-Müllerian hormone as a seminal marker for spermatogenesis in non-obstructive azoospermia

Anti-Müllerian hormone (AMH) also known as Müllerian inhibiting substance or factor, is a Sertoli cell-secreted glycoprotein responsible in male embryos for Müllerian duct regression. However, its role in adults remains unknown. AMH seminal concentrations have been evaluated using an enzyme-linked immunoassay in three groups of young men: group 1, fertile donors (n = 18); group 2, obstructive azoospermia (n = 9) after vasectomy or associated with deferent duct agenesia; and group 3, non-obstructive azoospermia with spermatogenesis deficiency and normal karyotype (n = 23). AMH was present in seminal plasma of most fertile donors at concentrations ranging from undetectable (<3.5 pmol/l) up to 543 pmol/l (geometric mean: 153 pmol/l), higher than the serum level (range <3.5 up to 67 pmol/l, geometric mean: 10.7 pmol/l, n = 13). Seminal AMH concentrations were undetectable in all obstructive azoospermic patients, confirming its testicular origin. In non-obstructive azoospermia (group 3), seminal AMH concentration was lower (range <3. 5-68.5 pmol/l, geometric mean: 17 pmol/l) than in fertile donors (P < 0.003) without correlation with plasma follicle stimulating hormone values. In group 3, comparison of seminal AMH concentration and the results of histological analysis of testicular biopsies revealed that undetectable AMH found in 14 cases was associated in 11 of them with lack of spermatozoa, while detectable concentrations of AMH (10-68.5 pmol/l) found in nine cases were associated in seven of them with persistent spermatogenesis. In the adult, AMH is secreted preferentially towards the seminiferous lumen. Although its relationship with spermatogenesis requires further investigation, our results suggest that seminal AMH may represent a non-invasive marker of persistent hypospermatogenesis in cases of non-obstructive azoospermia which may indicate the likely success of testicular spermatozoa recovery before intracytoplasmic sperm injection.

In vitro fertilization in women over 40 years of age. A study on retrospective data for eight years

A retrospective (1987-1995), single-center study was conducted to evaluate the IVF success rate in women who were 40 years and over. Controls were randomly selected patients who were 35 years or younger from the same center. The main evaluation criterion was the number of pregnancies initiated in each group and especially the number of full-term deliveries (take-home baby rate). Differences were considered as statistically significant for P < or = 0.05: A total of 194 IVF attempts in women 40 years or over were compared to 209 attempts in the control group. The mean ages of the two groups was 40.9 vs. 29.3 years (P < 0.001). The duration of follicle stimulation was 12.9 vs. 13.1 days (not significant, NS). The number of ampules was 29.6 vs. 29.2 (NS). Serum estradiol levels were 1435.8 vs. 2020.8 pg/ml (P < 0.001). Oocytes: 4.6 vs. 7.3 (P < 0.001). Embryos: 1.7 vs. 2.8 (P < 0.0001). Full-term deliveries: 3.6 vs. 13.4% (P < 0.05). Better oocyte retrieval was achieved (5.3 vs. 3.3; P = 0.001) in the group that was 40 years or over, but there were no differences in the rate of embryo transfer (1.9 vs. 1.3; NS) and full-term deliveries (4.2 vs. 2.9%) in a long protocol compared to a short one. The results of the study are similar to those found in the literature. Indications for standard IVF without oocyte donation should be carefully thought out and couples should be warned of the low success rate.

Pmt1 mannosyl transferase is involved in cell wall incorporation of several proteins in Saccharomyces cerevisiae

We constructed hybrid proteins containing a plant alpha-galactosidase fused to various C-terminal moieties of the hypoxic Srp1p; this allowed us to identify a cell wall-bound form of Srp1p. We showed that the last 30 amino acids of Srp1p, but not the last 16, contain sufficient information to signal glycosyl-phosphatidylinositol anchor attachment and subsequent cell wall anchorage. The cell wall-bound form was shown to be linked by means of a beta1,6-glucose-containing side-chain. Pmt1p enzyme is known as a protein-O-mannosyltransferase that initiates the O-glycosidic chains on proteins. We found that a pmt1 deletion mutant was highly sensitive to zymolyase and that in this strain the alpha-galactosidase-Srp1 fusion proteins, an alpha-galactosidase-Sed1 hybrid protein and an alpha-galactosidase-alpha-agglutinin hybrid protein were absent from both the membrane and the cell wall fractions. However, the plasma membrane protein Gas1p still receives its glycosyl-phosphatidylinositol anchor in pmt1 cells, and in this mutant strain an alpha-galactosidase-Cwp2 fusion protein was found linked to the cell wall but devoid of beta1,6-glucan side-chain, indicating an alternative mechanism of cell wall anchorage.

Specific repression of Tax trans-activation by TAR RNA-binding protein TRBP

The human T-cell leukemia virus type 1 (HTLV-1)-encoded Tax protein activates transcription from the long terminal repetition via association with host cellular factors. In this study, we searched for cellular proteins that interact with Tax and modulate its activity by using the yeast two-hybrid system. One of the strongest interactors was found to be identical with TRBP, which was previously shown to bind to the RNA encoded by the Tat response element of human immunodeficiency virus type 1. Interactions are demonstrated with Escherichia coli-expressed proteins in vitro and in mammalian cells, using one- and two-hybrid systems, and with antibodies that coprecipitate Tax and TRBP at physiological TRBP concentrations. Moreover, TRBP, when directed into the cytoplasm, is capable of preventing transport of Tax into the nucleus. A 60-amino-acid polypeptide suffices for binding to Tax. TRBP inhibits activation of transcription by both Tax and GAL4-Tax fusion proteins. Inhibition is specific for Tax and is not seen with the other activators tested. Our data are consistent with the interpretation that TRBP inhibits the interplay of Tax with the transcription machinery or accessory factors.

Stimulation of human sperm during capacitation in vitro by an adenosine agonist with specificity for A2 receptors

The effects of an adenosine agonist with specificity for A2 receptors, on human sperm prepared for in vitro fertilization (IVF), were examined to verify physiological effects and possible pharmacological use. 5' -N-ethyl-carboxamidoadenosine (NECA), when added at 100 microM over 30 min in B2 medium, did not induce a spontaneous acrosome reaction after 0, 3, and 6 h capacitation in B2, nor did it modify sperm motility. However, NECA increased the number of capacitated spermatozoa able to respond (p < 0.05) to A23187 (10 microM) after 6 h preincubation in B2 medium. This effect was associated with an increase in cAMP production, which was measured by RIA after 10 and 20 min incubation with NECA in uncapacitated sperm, and with changes in the kinetics of protein tyrosine phosphorylation as revealed by Western blot. Phosphorylation of a 95-kDa protein was enhanced by NECA in uncapacitated sperm and inhibited in capacitating sperm (incubated 1 h in B2), whereas phosphorylation of a 50-kDa protein was systematically enhanced whatever the preincubation time. NECA can stimulate uncapacitated human sperm via cAMP production and protein phosphorylation/dephosphorylation without inducing an acrosome reaction or influencing motility. Cyclic AMP-dependent protein kinase A seems to positively control protein phosphorylation involved in human capacitation. Adenosine present in the tubal fluid or produced by the spermatozoon itself may influence capacitation in vivo through sperm A2 receptors. In cases of male infertility, use of NECA in sperm handling for IVF should be evaluated as a means to improve capacitation without increasing the possibility of a premature spontaneous acrosome reaction.

Regulation by low temperatures and anaerobiosis of a yeast gene specifying a putative GPI-anchored plasma membrane protein [corrected]

Expression of the yeast Saccharomyces cerevisiae SRP1 (Serine-rich Protein) gene is shown here to be induced both by low temperature and anaerobic growth conditions. We show that anaerobic SRP1 expression is haem-dependent; however, haem influence does not operate through the action of the hypoxic-gene ROX1 repressor. The SRP1 promoter region displaying the stress-responsive elements is restricted to its first 551 bp, upstream of the initiation codon, although an upstream activation site contained in upstream sequences is required for full promoter activity. In addition, we demonstrate that the TIP1 gene, sharing similar nucleotide and polypeptide structure with SRP1, and previously reported to be a cold-shock-inducible gene, is also a hypoxic gene. Srp1 protein production is similarly induced by low temperature and anaerobic growth conditions. This protein, detected in the plasma membrane fraction, is shown to be exposed on the cell surface via a glycosyl-phosphatidylinositol membrane anchoring.

Characterisation and role of integrins during gametic interaction and egg activation

It has recently been proposed that some of the processes induced by fertilisation in mammals may be mediated by integrins. By performing immunofluorescence labelling and Western blots with antibodies directed against some of the alpha and beta subunits of integrins, we show here the presence of some of these proteins in human and hamster oocytes. Among them, alpha 2 and alpha 5 were also present on in vitro preparations of sea urchin egg cortices. In addition, antibodies raised against these two proteins were the most effective at inhibiting attachment and fusion of human spermatozoa with hamster oocytes. We suggest that alpha 2 and alpha 5 integrin chains may be common mediators in adhesion-fusion mechanisms triggered by fertilisation. Using similar techniques, we show that eggs are rich in three cytoskeletal proteins known to be linked to the beta chain of integrins: talin, vinculin and alpha-actinin. Moreover, we found that talin and alpha-actinin were associated with proteins phosphorylated on tyrosine after fertilisation in sea urchin eggs. We suggest that integrins might be involved during fertilisation and trigger egg activation through cytoskeletal structures.

[Expression and role of complement regulatory proteins on human gametes and pre-implantation embryos]

Human gametes and pre-implantation embryos express selectively several complement regulatory proteins. Membrane cofactor protein (MCP, CD46) and decay accelerating factor (DAF, CD55) are regulators for C3 convertases and protectin (CD59) is an inhibitor of the membrane attack complex. These three proteins were identified on human sperm and found to be functional. CD55 and CD59 were both expressed by the plasmic membrane of unfertilized oocytes and pre-implantation embryos. CD46 was not present on unfertilized oocytes but appeared at the 6/8 cell-stage embryo when human gene expression first occurs. Complement receptor 1 (CR1, CD35) and MHC class I antigens were not found on oocytes neither on embryos. Such a selective expression of complement regulatory proteins associated with the lack of MHC class I antigens may represent an immune protective mechanism by which human gametes and pre-implantation embryos escape from complement-mediated damage during their travel through the female genital tract. Indeed uterine, tubal and follicular fluids contain all the components of the complement cascade, including classical and alternative pathways. Nevertheless participation of CD46 and CD59 in cell to cell interaction during fertilization and/or implantation cannot be excluded. CD59 is an adhesive molecule involved in the rosette phenomena and CD46 has been described as the human receptor for measles virus, which binds through a fusion protein. Monoclonal antibodies raised against these two proteins (CD46 and CD59) are able to inhibit heterospecific fertilization between zona-free hamster oocytes and human spermatozoa suggesting the role of these proteins during fertilization.

Expression of complement regulatory proteins on human eggs and preimplantation embryos

PROBLEM

To investigate the relation between the complement system and reproduction, expression of complement regulatory proteins (C3b receptors and inhibitor of the membrane attack complex) were screened on unfixed human eggs and preimplantation embryos.

METHODS

Unfixed unfertilized oocytes and preimplantation embryos obtained from an in vitro fertilization program were stained by indirect immunofluorescence using monoclonal antibodies raised against membrane cofactor protein, (MCP or CD46), decay accelerating factor (DAF or CD55), protectin (CD59), human C3b/C4b receptor (CR1 or CD35), and major histocompatibility complex class I antigen (MHC class I).

RESULTS

CD55 and CD59 were both expressed by the plasma membrane of unfertilized oocytes and pre-implantation embryos. CD46 was not expressed by unfertilized oocytes but appeared at the 6-to-8 cell stage embryo when human gene expression first occurs. CD35 and MHC class I antigens were not expressed at all on oocytes and preimplantation embryos.

CONCLUSIONS

Selective expression of complement regulatory proteins (DAF and protectin) associated with the lack of MHC class I antigens may represent an immune protective mechanism by which human oocytes and preimplantation embryos escape complement-mediated damage during their travel through the female genital tract. Furthermore, participation of these complement regulatory proteins including MCP in cell to cell interaction during fertilization and/or implantation cannot be excluded.

Dynamics of human sperm acrosome reaction: relation with in vitro fertilization

OBJECTIVE

Acrosomal status has been studied on human sperm prepared for in vitro fertilization (IVF) and related to the rate of fertilization.

DESIGN AND PATIENTS

A group of 41 men with normal classical semen parameters, included in the IVF program of University of Nice for feminine tubal obstruction (n = 37) or unexplained infertility (n = 4), were evaluated in a prospective study and compared with a control group of 10 fertile donors.

MAIN OUTCOME MEASURES

Evaluation of acrosome status (spontaneous and A23187-induced acrosome loss) after 6 hours incubation in Ménézo's B2 medium was made by flow cytometry on suspended cells with a new immunofluorescence test recently reported by the authors based on a monoclonal antibody GB24.

RESULTS

Spontaneous acrosome loss remained low even after 6 hours capacitation (mean + 1 SD, 6.5% + 4.9%). Response to A23187 increased with the duration of preincubation with a marked response after 6 hours (29.5% + 8.9%). Low spontaneous acrosome loss (less than mean + 1 SD) and high response to A23187 (greater than mean - 1 SD) were observed in 25 out of 26 cases of group A with a high fertilization rate (greater than 50% fertilized oocytes). A high level of spontaneous acrosome loss and/or a lack of response to A23187 was observed in 2 of 7 cases of group B (fertilization rate less than 50%) and 6 of 8 cases of group C (unexplained unsuccessful fertilization).

CONCLUSION

Impaired acrosomal status can be associated with unexplained unsuccessful fertilization.

Localization and characterization of the acrosomal antigen recognized by GB24 on human spermatozoa

GB24, a mouse monoclonal antibody, recognizes a trophoblast-leukocyte cross-reactive antigen (TLX), which is likely identical to the membrane cofactor protein (MCP), a complement regulatory protein. GB24 reacts also with a human acrosomal sperm antigen (Fénichel et al.: J Reprod Fertil 87:699-706, 1989). By immunofluorescence or immunoperoxidase, testicular, epididymal, and ejaculated spermatozoa were found to be positive after fixation by acetone. Motile, suspended spermatozoa became positive only through conditions known to induce acrosome reaction (A23187, follicular fluid, contact with oocytes). Ultrastructural studies with immunogold staining localized this protein on the inner acrosome membrane and in the acrosomal content. By SDS-polyacrylamide gel electrophoresis, GB24 immunoprecipitated a unique protein of 48 kDa from capacitated and A23187-induced spermatozoa under reducing conditions. No cross-reactivity was found with mouse, boar, or ram spermatozoa. Localization of this human sperm antigen recognized by GB24 and its similarity with the TLX-MCP family antigens would suggest a possible role of this molecule during fertilization in sperm-egg binding or immune protection.

Evaluation of the human sperm acrosome reaction using a monoclonal antibody, GB24, and fluorescence-activated cell sorter

GB24 is a mouse monoclonal antibody raised against human trophoblast microvilli, which recognizes an antigenic determinant on the acrosomal region of the human sperm head. By indirect immunofluorescence, reactivity of GB24 could not be detected on freshly ejaculated spermatozoa but was strongly positive after sperm permeabilization with acetone. On viable, motile spermatozoa, reactivity appeared after induction of the acrosomal reaction with the calcium ionophore A23187. These results suggest that the antigen recognized by GB24 is present on the inner acrosomal membrane. A quantitative evaluation assay of the acrosome reaction on viable spermatozoa by flow cytometry using GB24 and indirect immunofluorescence is proposed.

Predictive value of hormonal profiles before stimulation for in vitro fertilization

Ovarian responses to stimulation for in vitro fertilization by clomiphene citrate menotropins have been correlated to the hormonal profiles determined during spontaneous cycles. The authors found 80% of high plasmatic luteinizing hormone (LH) and/or androgens levels associated with an inappropriated response: premature LH surge, multifollicular ovarian response, or dissociated cystic response, versus only 11% with appropriated responses. High plasmatic follicle-stimulating hormone existed in 71% of the no response group. Detryptoréline, a luteinizing hormone-releasing hormone agonist associated with menotropins, in a "short procedure" maintained the adequate responses and suppressed premature LH surges. The no response group was moderately improved, as were multifollicular and dissociated cystic response groups. Hormonal profiles could be useful predictive factors of the ovarian response for adaptation on the first procedure of stimulation.

[Induction of ovulation and fertilization in vitro. Attempted optimization using an analog of LH-RH: D-Trp6-LP]

The authors report the results of LH-RH blocking by an analogue for the purpose of obtaining a more constant inducement of ovulation. It concerns a delayed action product, the inconvenience of which is a possible extended action beyond thirty days, which could have an unfavorable effect on the luteal phase.

Triploidy with cyclopia and identical HLA alleles in the parents

A 22-week pregnancy was terminated after discovery of serious echographic abnormalities. Fetal examination showed cyclopia, sacral meningocele, and syndactyly. The karyotype was 69,XXX. The parents had identical HLA alleles A1, A2, and Bw21. The mechanism of the triploidy was determined by chromosome marker analysis to be digyny. The association of triploidy with holoprosencephaly and the parents' identical immunological status are discussed.

[Association of hereditary hydrocephalus and holoprosencephaly]

An infant with alobar holoprosencephaly and hydrocephalus is reported. The mechanism of hydrocephalus (aqueductal stenosis) and the mother's previous history (2 boys from a first marriage still-born with hydrocephalus) suggest a X-linked hydrocephalus. The association of a holoprosencephaly with this hereditary hydrocephalus is discussed.

[Retroperitoneal neuroblastoma diagnosed in utero. Apropos of 1 case]

The authors present a rare case of a retroperitoneal neuroblastoma discovered during a routine pregnancy check in the 29th week of amenorrhea and showing up as a 1.4 cm dia. hyperechoic nodule. A follow-up sonogram, obtained one month later, showed the lesion had increased in size. Following birth, the diagnosis was confirmed during surgery. The overwhelming importance of early diagnosis of this tumor for a favorable prognosis points out the value of systematic examination of the suprarenal regions of the foetus in the course of the last U.S. examination during pregnancy.

Cytogenetic study of 88 cases of refractory anemia

Data obtained on 88 patients with refractory anemia or preleukemia, without previous cytotoxic treatment, showed medullar chromosomal abnormalities in 32%. In 45% of the cases, the disease had progressed to acute nonlymphocytic leukemia. A high frequency of acute transformation (78%) was observed in patients with abnormal clones. These results are different from those of the Second International Workshop on chromosomes in Leukemia. The discrepancies may be related to the difference between the cases selected for submission to the workshop and those of this study. Serial studies on 28 patients with abnormal karyotypes showed that two different populations of patients were investigated: one with a terminal smoldering phase of leukemia and the other with true preleukemic disease. In the latter group, no predictive karyotype evolution was seen.

Familial occurrence of a syndrome with branchial dysplasia, mental deficiency, club feet, and inguinal herniae

A distinct probably autosomal recessive disorder was ascertained in a boy and his sister. The common features were signs of abnormal development of the first and second branchial arches, mental deficiency, club feet, and inguinal herniae. In addition the boy had hypospadias and the girl a ventricular septal defect.

Arthrogryposis-like signs in trisomy 18

Two cases of newborn male infants afflicted with trisomy 18 and with signs of arthrogryposis multiplex congenita (AMC) are described. Anomalies occurring in most cases of trisomy 18 such as polyhydramnios, reduced foetal activity, and skeletal muscle hypoplasia decrease articular movements and, thus might cause AMC. Since AMC is rarely associated with trisomy 18, chromosomal aberration is not the only factor involved in these cases.

[Monosomy 7qter (author's transl)]

A terminal deletion of the long arm of chromosome 7 is identified in a boy observed from birth to age 6 months. Eleven previously reported cases were reviewed. Eleven previously reported cases were reviewed. The most common features are microcephaly with brachycephaly, prominent forehead, large ears, a nose with bulbous tip, overlapping toes, genital abnormalities in the males and excess of subcutaneous tissue. Delayed mental and physical development is a general rule but visceral malformations seem uncommon.

[Partial trisomy 13 (13q14 leads to 13qter) in mosaic (author's transl)]

A case of partial trisomy 13 with mosaicism in a 6 1/2 year-old boy is reported. Concerning this case and according to previous data in the literature, the authors try to give a precise topology for trisomy 13; it is possible to outline phenotypes specific for a trisomy of both the proximal third and the distal two thirds of the chromosome, but it appears difficult to suggest a more precise picture for the topology of trisomy 13. This difficulty is related to the notion of phenotypic variability encountered in complete trisomy 13.