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Biomedical subjects

P Jouannet

Publications and source records attributed to P Jouannet.

At least 19 recordsLinked to original sources

Influence of sperm parameters on outcome of subzonal insemination in the case of previous IVF failure. off.

Subzonal insemination (SUZI) has been proposed for patients with sperm male factor infertility, and in cases of in-vitro fertilization (IVF) failures. However despite SUZI, there still remain couples with very low fertilization rates and even with fertilization failures. Since sperm parameters are known to influence the IVF fertilization rate, we investigated the relation between sperm parameters and the SUZI issue in cases of previous IVF failures with normal or subnormal sperm. Twenty-seven couples were included in the study and were split into two groups according to whether they had normal or subnormal sperm. In the first part of the study a randomized prospective trial comparing SUZI to classic IVF insemination was carried out (11 cycles). In the second part, all the oocytes had SUZI (35 cycles). None of the control inseminated oocytes fertilized. Including all the cases, the fertilization rate after SUZI was 29.8% with a pregnancy rate of 15.2% per cycle. We concluded that: (i) SUZI is efficient for achieving fertilization in cases of IVF failures; (ii) the post SUZI fertilization rate is inversely correlated to the percentage of acrosome defects in the semen (P < 0.001); and (iii) when the sperm is normal, the oocyte quality might be responsible for the previous IVF failures. In spite of a good fertilization rate for this indication, it seems that the chance of having a baby is low.

Adult

Unexplained in-vitro fertilization failure: implication of acrosomes with a small reacting region, as revealed by a monoclonal antibody.

To determine the acrosomal characteristics related to in-vitro fertilization (IVF) outcome, spermatozoa from 50 men whose wives had resorted to IVF have been studied by indirect immunofluorescence microscopy with anti-human pro-acrosin monoclonal antibody 4D4 (mAb 4D4), prior to and after incubation in a capacitating medium. The antibody labelled only the acrosomal principal region (APR), revealing its shape (i.e. normal, small or amorphous) and its status (i.e. unreacted, partially or totally reacted). The IVF outcome distinguished: (i) spermatozoa which were able to fertilize at least one oocyte in vitro (group I; n = 25) and (ii) spermatozoa which failed to fertilize any oocyte in vitro (group II; n = 25). The semen characteristics of the two sperm groups, including the acrosome morphology, were similar according to conventional analysis. The mAb 4D4 detected in both the whole and the swim-up sperm cell fractions a lower percentage of normal APR in group II (< 50% for 10 patients in group II versus one patient from group I), which was related to a higher percentage of small APR. Moreover, after 21 h incubation, group II had a lower acrosomal loss index. The spermatozoa of five patients of this infertile group II did not undergo acrosomal modification whereas spermatozoa of all group I patients underwent the acrosomal reaction. The data showed that the relationship between acrosomal anomalies and IVF failure is mainly due to an increased incidence of acrosomes with a reduced size of the region involved in the acrosome reaction. Immunodiagnosis of this acrosomal region by means of mAb 4D4 is informative for IVF outcome.

Acrosin

Effects of pH on the reactivation of human spermatozoa demembranated with Triton X-100.

The aim of this work was to study the role of different parameters involved in the motility of human spermatozoa. Human spermatozoa were totally demembranated with 0.05% Triton X-100, and the demembranation was checked using electron microscopy. We have shown that, with a concentration of ATP-Mg lower than 2 mM, a pH effect was observed with a dose-dependent motility reactivation at pH 7.1, with 14% +/- 2.0% motile cells at 1 mM ATP-Mg and a straight line velocity (VSL) of 12.0 +/- 1.4 microns/sec. However, at pH 7.8, more than 65% of the spermatozoa were reactivated with as low as 0.02 mM ATP-Mg and 77.8% +/- 2.5% of them were motile at 1 mM ATP-Mg and had a VSL of 23.4 +/- 3.9 microns/sec. The depletion of free calcium by the addition of 0.5 mM EGTA in the reactivation medium (RM) improved the percentage of motile cells and the VSL most markedly at low ATP-Mg and low pH. If no MgSO4 was added in RM, cells were not motile at pH 7.8, but 30-40% reactivated at pH 7.1. If 5 mM Ca2+ was added to the RM, up to 88% of the cells became reactivated at both pHs, but the beat frequencies were very low, suggesting different mechanisms of reactivation when Mg2+ or when Ca2+ is present in the RM.

Adenosine Triphosphate

In-vitro effects of anti-sperm antibodies on human sperm movement.

The present study was designed to investigate whether autoantibodies to external domains of the sperm plasma membrane affect the movement of normal motile spermatozoa. Eight sera and 20 seminal plasma samples containing high levels of anti-sperm antibodies as well as antibodies eluted from the sperm fraction of 19 autoimmune ejaculates were incubated with donor's motile spermatozoa, obtained by swim-up migration in Tyrode's solution. Sperm movement was analysed using 1 s exposure microphotography when greater than 70% of the spermatozoa were coated with antibodies (after 30-90 min of incubation). At least 50 tracks of progressively motile spermatozoa were analysed in order to obtain the mean values of the amplitude of lateral head displacement (ALH) and the velocity of progression (VSL). Serum antibodies and sperm eluted antibodies had quite consistent but opposite effects on sperm movement; serum antibodies increased ALH and decreased VSL whereas eluted antibodies decreased ALH and increased VSL. Seminal antibodies did not affect these two parameters significantly. Furthermore, seminal antibodies and sperm eluted antibodies obtained from the same ejaculates had distinct effects on ALH and/or VSL. This diversity was apparently not linked to antibody isotype or localization on the sperm membrane; it might be due to differences in the composition of the extracellular media. These results suggest a dynamic effect of anti-sperm antibodies on sperm movement, a possibility that merits further investigation.

Autoantibodies

Puberty in the male chimpanzee: progressive maturation of semen characteristics.

Cellular and biochemical characteristics of semen obtained by masturbation were studied in 5 pubertal chimpanzees during 1.5 yr. The dental age corresponding to the beginning of the pubertal testicular growth (Po) ranged from 5.0 to 8.3 years (mean = 6.7 +/- 1.2 yr). Time-related variations of all studied parameters were analyzed according to Po and, therefore, independently of the dental age. The emission of first ejaculates, and therefore the onset of activity of the accessory sex gland, was estimated to occur 4 mo after Po. The ejaculate volume (n = 132, r = 0.704, p less than 0.001), as well as the total amounts of l-carnitine (n = 65, r = 0.649, p less than 0.001), fructose (r = 0.522, p less than 0.001), citrate (r = 0.748, p less than 0.001), and acid phosphatase (r = 0.756, p less than 0.001) increased with time. First-obtained ejaculates contained no spermatozoa. Spermarche was estimated to occur 9.4 mo after Po. Total sperm count increased with time (r = 0.595, p less than 0.001). The motility and viability of spermatozoa increased with time (r = 0.474, p less than 0.01 and r = 0.632, p less than 0.001, respectively) while their morphology did not vary. The volume of the liquefied fraction and its content in free spermatozoa considered as available for fecundation remained low until the end of the study, most likely because of a delayed maturation of the prostate. This study shows that the maturation of the male genital tract is a progressive process. (ABSTRACT TRUNCATED AT 250 WORDS)

Animals

Puberty in the male chimpanzee: time-related variations in luteinizing hormone, follicle-stimulating hormone, and testosterone.

The onset of pubertal testicular growth (Po) occurred in 12 out of 20 male chimpanzees surveyed monthly for at least 3.7 yr. When animals were synchronized according to Po, the mean weight gain was found to be higher before than after Po, and testicular volume started to rise immediately after Po. The earlier significant hormonal events were a rapid rise in LH and a slight testosterone increase occurring 6 mo before Po. Thereafter, the levels of LH remained elevated while testosterone continued to rise in parallel with the testicular volume. FSH levels increased suddenly at Po, 6 mo after the LH increase. FSH remained elevated for only 9 mo, then dropped to prepubertal levels. The dissociation between onsets of pubertal increases in LH and FSH secretions suggests that the complete reawakening of the hypothalamic-pituitary unit lasts several months. The secondary drop of FSH, occurring at the time of spermarche, may be induced by factor(s) secreted by the testis.

Animals

In-vitro processing of sperm with autoantibodies and in-vitro fertilization results.

In-vitro fertilization and embryo transfer were carried out in twenty infertile couples with significant levels of anti-sperm antibodies on the ejaculated spermatozoa. Over 21 cycles (15 couples), 95 mature oocytes were collected and inseminated with spermatozoa obtained by swim-up migration after rapid dilution and washing of the ejaculates. An overall fertilization rate of 38.9% was obtained with these post-migration (PM) preparations. When greater than 70% of the inseminated spermatozoa were covered with both IgG and IgA antibodies, only 14% of the 43 oocytes were fertilized. A higher fertilization rate was obtained with the PM preparations containing less than 70% of spermatozoa coated with one or both classes of antibodies. Under these conditions 60% of the 52 oocytes were fertilized. Fertility rate correlated better with IgG than with IgA antibody levels. In order to decrease the proportion of antibody-coated spermatozoa in the inseminated populations, washed spermatozoa were immuno-adsorbed on Mage's plates before swim-up migration. Over 11 cycles (10 couples) 52 mature oocytes were inseminated with these post-migration immuno-depleted sperm preparations (PMP) containing less than 65% of antibody-coated spermatozoa: 31% of the oocytes were fertilized. This rate compares favourably to IVF results obtained with the PM preparations with greater than 70% of spermatozoa coated with both classes of antibodies. In five couples who had different IVF attempts with the two sperm preparations, the immuno-depletion resulted in a slight increase in the fertilization rates: 10% for the PM preparations versus 26% for the PMP preparations. Sperm binding to the zona pellucida was decreased in the majority of unsuccessful attempts.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult

Influence of ejaculation frequency on semen characteristics in chimpanzees (Pan troglodytes).

Semen samples were obtained by masturbation from 6 chimpanzees and the spontaneously liquefied fraction and the remaining coagulum were studied separately. When semen was collected once or twice a week, large intra-individual variations were observed for all measures. The liquefied fraction represented 26.5 +/- 3.2% (weighted mean +/- s.d.) of the total ejaculate but contained 51.3 +/- 3.8% of all emitted spermatozoa. Fructose concentration was higher in the coagulum than in the liquefied fraction (29.3 +/- 3.0 mumol/ml vs 12.0 +/- 2.7 mumol/ml, P less than 0.001) whereas acid phosphatase was less concentrated in the coagulum than in the liquefied fraction (3.5 +/- 0.3 x 10(3) IU/ml vs 13.0 +/- 0.9 x 10(3) IU/ml, P less than 0.001). L-Carnitine and citrate concentrations did not differ between the two fractions of the ejaculate. When semen collection was repeated every hour for 5 h, the ejaculate volume increased from 2.6 +/- 0.7 to 4.7 +/- 0.6 ml (P less than 0.001), whereas total sperm count decreased from 1278 +/- 872 x 10(6) to 587 +/- 329 x 10(6) (P less than 0.05) between the 1st and the 6th ejaculate. In the spontaneously liquefied fraction, the sperm count decreased from 984 to 369 x 10(6). The 6 successive ejaculates gave a total of 20.2 +/- 7.6 ml and 4278 +/- 2884 x 10(6) spermatozoa. The increase of the ejaculate volume was essentially due to an increase of the volume of the coagulum which closely correlated with total amount of fructose (from seminal vesicles) (r = 0.913, P less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals

Influence of image sampling frequency on the perceived movement characteristics of progressively motile human spermatozoa.

Tracks of 30 progressively motile washed human spermatozoa were plotted manually from 200-Hz frame rate video recordings. Tracks at 100, 66.7, 50, 40, 33.3, 25, 20, 10, and 5 Hz were then constructed using every 2nd, 3rd, 4th, 5th, 6th, 8th, 10th, 20th, or 40th point. The 200-Hz tracks were analyzed by traditional manual methods, and all ten sets of tracks analyzed using a computer-assisted method ("Videomot," developed originally to analyze 30-Hz tracks) to eliminate observer bias. Progression velocity (VSL) remained constant under all analysis conditions. Average path velocity (VAP) also remained essentially constant, although Videomot was less reliable at high frame rates due to problems in determining the average path. Curvilinear velocity (VCL) was very frame rate dependent (the 25-Hz mean value was only 56.5% of that at 200 Hz), and Videomot was more accurate than manual analysis at 200 Hz. Values of the amplitude of lateral head displacement (ALH) were acceptable at most frame rates. At less than 66.7 Hz the inclusion of spurious curvilinear track deviations caused lower mean ALH values, and at 5 Hz ALH could not be measured since the track was essentially the average path. Beat/cross frequency (BCF) was also frame rate dependent; at high rates there was the same problem as with ALH measurements, while at less than or equal to 25 Hz the maximum BCF was restricted by the frame rate. We conclude that human sperm movement characteristics can be measured at frame rates ca. 30 Hz but only if the constraints affecting VCL and BCF values are understood and accepted. Finally, less than 10 Hz can only give values for VSL and, perhaps, VAP.

Humans

Male factors and the likelihood of pregnancy in infertile couples. I. Study of sperm characteristics.

A prospective study of 394 infertile men was conducted over 3 years following a primary semen analysis. The cumulative pregnancy rate was 43 and 64% after 1 and 3 years, respectively. The pregnancy rate was significantly higher in the secondary infertile group. The study of various sperm factors and the occurrence of pregnancy showed that they were not of equal significance in predicting male fertility potential. The percentage of pregnancies decreased significantly only when the sperm concentration was less than 5 x 10(6)/ml. The pregnancy rate increased significantly with the percentage of motile sperm. The percentage of sperm with normal morphology was also found to be significantly higher when a pregnancy occurred than when the couple remained infertile (43.6% vs 37.7%). In a detailed morphological analysis of the sperm, six abnormalities (microcephaly, double head, amorphous head, cytoplasmic droplet, bent tail and coiled tail) were found to be significantly more frequent when a pregnancy did not occur. The most predictive value was given by the Multiple Anomalies Index (MAI), which is the mean number of abnormalities observed per abnormal sperm. The pregnancy rate was significantly lower after both 1 and 3 years when the MAI was greater than 1.6. Multivariate analysis showed that the best prognostic indicator of fertility was given by the percentage of motile sperm and the MAI, particularly in patients with primary infertility.

Female

Male factors and the likelihood of pregnancy in infertile couples. II. Study of clinical characteristics--practical consequences.

A prospective study of 394 infertile men was conducted over 3 years following a primary semen analysis. Simple comparisons between the groups of men whose partners conceived and those that did not, showed that the mean duration of infertility in the primary infertile group was significantly shorter when a pregnancy was observed, while age differed significantly between the two populations in the secondary infertile group. Multivariate analyses, taking these variables and sperm characteristics into account, showed that prognostic variables for the occurrence of pregnancy were the duration of infertility, sperm motility and the multiple anomalies index in the primary infertile group, and age of the male partner and percentage of normal sperm in the secondary infertile group. Tables for estimating the probability of observing a pregnancy as a function of these criteria are presented. In this study no positive influence of treatment on the occurrence of a pregnancy was found during the 3 years following the first semen analysis.

Age Factors

Cellular and biochemical characteristics of semen obtained from pubertal chimpanzees by masturbation.

Semen characteristics were studied in 6 wild-born chimpanzees with dental ages ranging approximately from 6 to 12 years. The animals formed 2 groups, early pubertal (EP, N = 3, 6-9 years) and late pubertal (LP, N = 3, 11-12 years). Mean body weight, testicular volume and serum androgen concentration were significantly lower in Group EP (32.2 +/- 1.6 kg, 34.0 +/- 7.7 cm3, 2.1 +/- 0.1 ng/ml) than in Group LP (55.7 +/- 5.7 kg, P less than 0.01; 100.5 +/- 11.9 cm3, P less than 0.01; 3.6 +/- 0.7 ng/ml, P less than 0.05). Ejaculates were obtained by masturbation in all subjects. The mean ejaculate volume was lower in Group EP (0.56 +/- 0.20 ml) than in Group LP (3.77 +/- 0.73 ml, P less than 0.01). In Group EP, 2 animals were azoospermic while the third produced semen with means of 57.1 x 10(6) spermatozoa per ml, 20% motility and 40% vitality. These values were low when compared with the mean values of Group LP (376 x 10(6) spermatozoa per ml, 67% motility and 78% vitality). Mean total sperm count was correlated with testicular volume (r = 0.84) and serum androgen concentration (r = 0.96). The mean concentrations of L-carnitine, fructose, citrate and acid phosphatase for the two groups were not significantly different; but, related to the differences in ejaculate volumes, their total amounts in total ejaculate were lower in Group EP than in Group LP. These results suggest that, in chimpanzees, mechanisms of seminal plasma production and ejaculation are functional early in the reproductive life and that the emission of spermatozoa occurs later.

Acid Phosphatase

[Flagellar motility amd movement of boar spermatozoa during epididymal transit].

The motility of boar spermatozoa during epididymal transit was analysed in vitro using various techniques. From the head to the cauda there was an increase of the percentage of motile and progressive spermatozoa. During maturation there was a progressive reduction of flagellar bend curvature while flagellar beat frequencies increased. A three dimensional pattern of flagellar beating responsible for cell rotation and straight line progression of spermatozoa was observed only in caudal epididymis. The addition of epididymal fluid protein to the media could increase the number of motile cells at the various levels but had no influence on the characteristics of flagellar bending.

Animals

Impaired ability of human spermatozoa to penetrate zona-free hamster oocytes: is a postacrosomal sheath anomaly involved?

We selected 17 infertile men whose sperm ultrastructural study revealed at least 70% of spermatozoa with postacrosomal sheath (PAS) anomalies. Among the other sperm head defects, those affecting the nuclear shape were most frequently encountered and were highly correlated with PAS anomalies (r = +0.71; P less than .01). PAS anomalies were also correlated with chromatin condensation defects (r = +0.67; P less than .01) and acrosome anomalies (r = +0.53; P less than .05). Those spermatozoa were tested for their ability to penetrate zona-free hamster oocytes and were compared to a control sperm population. It was shown that sperm head morphological anomalies impaired the ability of spermatozoa to attach to and penetrate the oocyte. The highest significant and negative correlations were found between the penetration rate and 1) the percentage of spermatozoa with PAS anomalies (r = -0.81; P less than .01) and 2) the percentage of spermatozoa with nuclear shape anomalies (r = -0.66; P less than .01). The effect of PAS anomalies on human fertilization process are discussed.

Acrosome

In-vitro fertilization results from thirteen women with anti-sperm antibodies.

Thirteen infertile women with high titres of spermagglutinating antibodies in their serum and/or in cervical mucus underwent in-vitro fertilization (IVF) and embryo transfer (ET). Fertilization occurred in 68% of the oocytes in a serum-free medium. Eight pregnancies were obtained in 22 IVF cycles (36.4%). Anti-sperm antibodies were found in the follicular fluids of 5 out of the 11 women with circulating antibodies. Fertilization results were independent of both the localization and the level of anti-sperm antibodies. From these data we can conclude that IVF-ET is a suitable treatment for long lasting female infertility linked to anti-sperm immunity.

Antibodies

Sperm analysis.

Human semen analysis is the first biological step of male fertility assessment. Its performance requires the use of standardized and objective procedures. The results of the tests may allow to conclude to a man's sterility when they reveal e.g. an azoospermia or an alteration of sperm morphology or motility incompatible with fertilization. More often however, it is difficult to precisely determine the relationships between the observed sperm anomalies and infertility. In a follow-up study of 520 infertile men over 3 years, the pregnancy rate was found to be significantly lower only in the cases where sperm concentration values were less than 5.10(6)/ml and unchanged for concentrations above this value. No threshold values were found for sperm motility and morphology, although the chances of conception were closely related to these two parameters for sperm concentration values above 5.10(6)/ml. Various tests have been described to evaluate the human sperm ability to migrate through the female genital tract and fertilize the oocyte. These tests and the human in vitro fertilization assay allow a better understanding of the structural and dynamical parameters mostly involved in sperm function.

Fertilization in Vitro

Abnormal distribution of the periaxonemal structures in a human sperm flagellar dyskinesia.

The spermatozoa from four infertile patients showing a flagellar dyskinesia due to abnormal flagellar wave development have been studied by light and transmission electron microscopy (TEM) for flagellar morphology. No axonemal anomalies were found but modification of the periaxonemal structures was observed. The results of a stereological analysis revealed abnormal extension of the individual dense fibres along the axoneme in the four cases as compared with a control group. The order of termination of those structures was therefore altered. However, the overall fibre extension was the same in both groups (ie, 60% of the principal piece). The number and the location of the longitudinal columns were also modified, the predominant anomaly being the presence of a single column. The possible influence of those structural anomalies on the pattern of sperm movement is discussed. Our observations seem to agree with a previous hypothesis of the literature, that the dense fibres might play a role in flagellar flexibility. More particularly, we suggest that the abnormal extension of dense fibres No. 2, 3, and 4 and the symmetric distribution of the dense fibres on both sides of the plane of beating may alter the flagellar curvature amplitude and the cell rotation frequency.

Actin Cytoskeleton