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Biomedical subjects

S Hamamah

Publications and source records attributed to S Hamamah.

At least 37 records · Page 2Linked to original sources
PubMed1999

Revival of the natural cycles in in-vitro fertilization with the use of a new gonadotrophin-releasing hormone antagonist (Cetrorelix): a pilot study with minimal stimulation.

Natural cycles were abandoned in in-vitro fertilization (IVF) embryo transfer, due to premature luteinizing hormone (LH) surges--and subsequent high cancellation rates. In this study, we investigated the administration of a new gonadotrophin-releasing hormone antagonist (Cetrorelix) in the late follicular phase of natural cycles in patients undergoing IVF and intracytoplasmic sperm injection (ICSI). A total of 44 cycles from 33 healthy women [mean age 34.1 +/- 1.4 (range 26-36) years] were monitored, starting on day 8 by daily ultrasound and measurement of serum concentrations of oestradiol, LH, follicle stimulating hormone (FSH) and progesterone. When plasma oestradiol concentrations reached 100-150 pg/ml, with a lead follicle between 12-14 mm diameter, a single injection (s.c.) of 0.5 mg (19 cycles) or 1 mg (25 cycles) Cetrorelix was administered. Human menopausal gonadotrophin (HMG; 150 IU) was administered daily at the time of the first injection of Cetrorelix, and repeated thereafter until human chorionic gonadotrophin (HCG) administration. Four out of 44 cycles were cancelled (9.0%). No decline in follicular growth or oestradiol secretion was observed after Cetrorelix administration. A total of 40 oocyte retrievals leading to 22 transfers (55%) was performed. In 10 cycles (25%), no oocyte was obtained. Fertilization failure despite ICSI occurred in six cycles (15%). In two patients the embryo was arrested at the 2 pronuclear (PN) stage. The stimulation was minimal (4.7 +/- 1.4 HMG ampoules). A total of seven clinical pregnancies was obtained (32.0% per transfer, 17.5% per retrieval), of which five are ongoing. Thus, a spontaneous cycle and the GnRH antagonist Cetrorelix in single dose administration could represent a first-choice IVF treatment with none of the complications and risks of current controlled ovarian hyperstimulation protocols, and an acceptable success rate.

Adult↗
PubMed1998

Pre or post-operative medical treatment with nafarelin in stage III-IV endometriosis: a French multicenter study.

OBJECTIVES: To determine the effectiveness of a 6-month course of nafarelin in the treatment of stage III-IV endometriosis and to determine if pre-operative use of nafarelin facilitates surgery. DESIGN: Prospective, multicenter, clinical trial. SETTING: Eight university hospitals and two private practice institutions in France. PATIENTS: Fifty-five patients with stage III and IV endometriosis. Two were excluded. INTERVENTIONS: The severity of endometriosis was assessed at the time of laparoscopy and patients were randomized to have either laparosopic surgery at that time following 6 months of nafarelin therapy (n=28), or laparoscopic surgery following 6 months of nafarelin therapy (n=25). All had 200 microg intranasal nafarelin twice a day for 6 months and a second look laparoscopy. MAIN OUTCOME MEASURE: Clinical efficacy, tolerance to the treatment. RESULTS: Efficacy and tolerance to the treatment were the same in both groups. AFS scores compared on both laparoscopies were significantly better if nafarelin was given prior to surgery (P=0.007). CONCLUSIONS: This preliminary study shows that in cases of combined medico-surgical treatment for stage III-IV endometriosis, preoperative medical treatment with GnRH-a gives a better AFS score improvement, but no conclusion was possible whether preoperative treatment facilitates surgery.

Adult↗
PubMed1998

Quantification by magnetic resonance spectroscopy of metabolites in seminal plasma able to differentiate different forms of azoospermia.

The aim was to determine whether proton magnetic resonance spectroscopy (1H-MRS) of metabolites such as glycerophosphorylcholine (GPC), choline, citrate and lactate in human seminal plasma can be used to differentiate (i) different azoospermic patients and (ii) different forms of spermatogenic failure including those who had undergone radiation therapy or chemotherapy. Semen samples were provided by men with obstructive azoospermia and spermatogenic failure who had serum follicle stimulating hormone (FSH) values within the normal range and either more or less than normal. Four prominent constituents of seminal plasma were identified by 1H-MRS: GPC, choline, citrate and lactate. The peak area ratios of choline/citrate as well as choline/lactate were significantly different (P < 0.01) between groups with spermatogenic failure and obstructive azoospermia. When the serum FSH values were normal in men with spermatogenic failure and obstructive azoospermia, a significant difference was found in the GPC/choline ratio (P < 0.001). When the FSH values were normal, the GPC/choline ratio appeared to be a very important parameter able to differentiate not only between cases of spermatogenic failure and obstructive azoospermia but also between different forms of spermatogenic failure. These results demonstrate the potential use of 1H-MRS on human seminal plasma in a new approach in the management of male infertility.

Antineoplastic Agents↗
PubMed1998

Role of the ionic environment and internal pH on sperm activity.

In most species, once formed in the testis, spermatozoa are bathed in a fluid where they remained immobile and with a very low level of metabolism. This immotile status is understandable in view of the need to preserve the sperm energy reserve and to decrease the risk of alteration to membranes, internal structures and biochemical compounds by endogenous oxidizing agents produced by mitochondrial activity. This quiescent phase can be of different lengths and finishes when the semen is released into the external environment where the spermatozoa become motile and metabolically active. For invertebrates, and some fish, sexual activity is generally seasonal and fertilization is external. Spermatozoa, once differentiated in the gonad, remain there completely quiescent until they are released into the external medium, which is either fresh water or sea water. Dilution of the testicular fluid surrounding the spermatozoa allows the initiation of motility and metabolism. In fact, this seminal fluid has an inhibitory effect on sperm activity. For birds and mammals (including humans), the situation is much more complex. In these species, sperm production is almost continuous although for some of them, seasonal variations occur. When spermatozoa are released from the Sertoli cells, they are rapidly exported from the testis to the epididymis where the composition of the surrounding medium is profoundly modified. For most species, the spermatozoa remain immobile in the lower part of the epididymis, even though they have gained the capability to be fully motile as shown by dilution in an adequate medium. In vivo, motility is activated when the spermatozoa are mixed with secretions from the different accessory glands during ejaculation. This paper will review the role played by environmental factors, such as ions, in the activation of sperm motility and metabolism of different species of invertebrates and vertebrates. Special attention is given to changes in sperm internal pH, its regulation and role in the activation of sperm axonemal movement.

Animals↗
PubMed1998

[Reproduction techniques and infectious risks: study of practices in French centers in 1997].

In the absence of specific legislation or consensual recommendations in France regarding the routine screening of infectious transmissibility risk before intra-couple medically assisted procreation (MAP), an inquiry about the practice of screening management in France has been performed. 500 questionnaires were sent, and 104 answers were received. The results of such inquiry coming from 62 private and 42 public centers are the subject of this paper.

Female↗
PubMed1997

Case report and review of the literature: primary twin ovarian pregnancy.

A case report of primary twin ovarian pregnancy is presented. A 36 year old woman, gravida 4 para 3, was admitted to the hospital for suspected ectopic pregnancy, with vaginal bleeding at 11 weeks after her last menstrual period, associated with pelvic pain. An endovaginal ultrasonography led to the diagnosis of twin ovarian right ectopic pregnancy with two dead fetuses associated with a compartmentalized haemoperitoneum. Unilateral oophorectomy was carried out by laparotomy. Histological studies confirmed an uni-ovular di-amniotic ovarian pregnancy. Seven cases of ovarian twin pregnancies are reviewed in the literature. This case is the first one where diagnosis has been made by endovaginal sonography.

Adult↗
PubMed1997

[The future of male contraception: immunocontraception by preventing gamete interaction].

This paper summarize the main data relevant to the obtention of contraceptive vaccines based on spermatozoa as well as zona pellucida antigens. The development of novel forms of contraception is one way in which this global population problems can be tackled. The sperm as well as the oocyte antigens are studied as possible contraceptive vaccine candidates are the subject of this review.

Contraceptive Agents, Male↗
PubMed1996

Morphometric epididymal epithelium analysis in obstructive azoospermic men: predictive values in fertilization rates.

PURPOSE: Our purpose was to determine the obstructed epididymal epithelium morphometric state and to elucidate the influence of morphometric parameters on the fertilizing ability of aspirated spermatozoa. METHODS: During MESA with IVF, epididymal tissue samples were carefully dissected, fixed, and prepared for morphometric analysis. The epithelium of the three regions was studied: head, body, and tail (when present). The total area/luminal area ratio, epithelium thickness, and stereocilium length were measured. RESULTS: We have found significant differences in the total area/luminal area ratio, epithelium thickness, and stereocilium length in obstructed epithelium length > 4 versus 0.5-2 cm (P < or = 0.01). Epithelium thickness and stereocilium length were significantly lower when no fertilization was observed in IVF. CONCLUSIONS: These results suggest that morphometric data of obstructed epididymis epithelium can be used as a means of explaining the failure of IVF with epididymal spermatozoa.

Cell Separation↗
PubMed1996

Identification of hyaluronic acid and chondroitin sulfates in human follicular fluid and their effects on human sperm motility and the outcome of in vitro fertilization.

This study measured glycosaminoglycans (GAGs) in human follicular fluid (hFF) obtained from patients undergoing hormonal stimulation with combined GnRH agonist followed by gonadotropin hormone (hMG or FSH) for in vitro fertilization (IVF). The GAGs were partially characterized through the use of various mucopolysaccharidases and then their effects tested on human sperm motility. In hFF, the GAG and protein concentrations were 4.4 +/- 1.3 mg/L and 32.6 +/- 3.2 g/L respectively. Chondroitins (CS) and hyaluronic acid (HA) significantly stimulate sperm motion in comparison to the control. The oocytes inseminated with GAGs-pretreated spermatozoa showed a significantly higher rate of cleavage and pregnancy or delivered number. The present results suggest that hFF is a rich source of sulfated glycosaminoglycan (CS), and non-sulfated glycosaminoglycan (HA). The stimulatory effects of hFF on human sperm motility may well depend on CS and HA. GAGs pretreated sperm may enhance the fertilizing ability of spermatozoa and thus the IVF outcome.

Chondroitin Sulfates↗
PubMed1996

Internal pH of human spermatozoa: effect of ions, human follicular fluid and progesterone.

The internal pH (pHi) of human spermatozoa was measured by the fluorescent indicator 2,7-bicarboxyethyl-5,6-carboxyfluorescein acetoxymethyl ester (BCECF-AM) and the distribution of the radioactive [14C]-methylamine under different external ionic conditions. The effect of the addition of progesterone and human follicular fluid (HFF) on the spermatozoa pHi was also analysed. The pHi values obtained were almost identical with the two probes used. In sodium (NaM) and potassium (KM) media, a linear relationship between the internal and external pH was observed. In NaM, the pHi values were approximately 0.4 pH unit less than the external pH. In KM, the pHi measured was higher than in NaM and only slightly inferior to the external pH (0.1-0.2 pH unit). Addition of 10 microM progesterone, oestradiol 17 beta or 20% HFF to spermatozoa incubated at pH 7.2 in NaM did not induce any rapid variation of the BCECF fluorescence or change in the accumulation of methylamine. A slight change in pH (approximately 0.5 units) occurred with progesterone after 15 min. As a control, addition of 10 mM of NH4Cl induced a rapid alkalinization (0.4 pH unit) of the cell interior while 10 mM lactate produced only a slight acidification (approximately 0.2 pH unit). Under the same conditions (NaM, pH 7.2), the pHi of the spermatozoa prepared by Percoll gradient was found more acidic by 0.2 pH unit than washed unfractionated spermatozoa. Progesterone, oestradiol 17 beta and HFF had no effect on the pHi of these spermatozoa. The results obtained in this study show that it is possible to measure accurately the internal pH of human spermatozoa. Internal pH was found to be dependent upon the pH of the external medium and a quasi-linear relationship exists between the internal and external pH, suggesting no specific pH regulatory mechanisms. Our data suggest instead that the protons, under our experimental conditions, are passively distributed. Progesterone, oestradiol 17 beta and HFF, known to promote both capacitation and the acrosome reaction, do not act through a rapid pHi change.

Estradiol↗
PubMed1996

[Preimplantation assessment: experimental data on animals and humans].

Assessing and/or improving the implantation prognostic remain a major goal for research studies as well as for teams doing embryo transfer in many species. Criteria for such a goal were focussed ten years ago and combined theoretically: -sensitivity for applying to one embryo; -clear cut-off for individual decision; -fastness to be suitable for embryo transfer in due time; -no toxicity or invasiveness for embryo; -finally some simple technical approach in order to be applies by a large number of teams. Moreover whatever may be qualitative or quantitative criteria, they should be relied to the final result as alive newborn. The more ancient way to appreciate embryo quality deal with the simple observation of morphological and kinetic criteria about embryo, but such non invasive approach was obviously limited, in spite of the positive influence of regular blastomers, absence of fragmentation and synchronization with time of transfer on implantation rate. The major transcriptional activity of human embryo developing between 6 and 8 cells stage, of course, were unassessed by transfer to day 2. Moreover the apparent quality of the embryo better reflected oocyte quality than embryo quality. Coculture development encompassed only partially such limitation. Using fluorescent probes, it was possible to evaluate some metabolic activity as well as membrane integrity, but such criteria revealed to be both invasive and uneasily reliable with developmental ability of the embryo. Methods dealing with glucidic, protidic or lipidic metabolisms are developed elsewhere, but revealed uneasy to apply, due both to their invasiveness or technical difficulties and their large inter-individual variability. Some hope has raised by the finding of growth factors or cytokines which are expressed by the embryo and/or embryotrophic but a lot of works remain to be down before an easy practical application.

Animals↗
PubMed1995

[Repeated spontaneous abortions: discussion on its etiologies].

Spontaneous abortion (SA) is the most common complication of pregnancy and is estimated to be between 15 to 20% of all clinical pregnancies. However for "recurrent spontaneous abortion" (RSA) the frequency is more difficult to determine (between 0.05 to 1%). The purpose of this paper is to review the literature concerning RSA etiologies. Particular attention has been paid to the male factors contribution in RSA. Because of the poverty of controlled studies, answers to questions about the RSA are very difficult.

Abortion, Habitual↗
PubMed1993

[Exploration of pathological sperm and its fertilizing power].

The exploration of human sperms has considerably progressed during the last few years, side by side with the development of medically assisted procreation techniques. The sperms are explored by a battery of techniques which evaluate their functional state and the expression of their fertilizing power. Sperm count and motility assessment remain the basic examination in the exploration of couples' infertilities but other more sophisticated techniques can be used to evaluate certain stages in the fertilization process, including the recognition by, and attachment of the sperm to the zona pellucida of the oocyte, its penetration into this zone, the fusion of sperm and oocyte membranes and the transformation of the nucleus into a male protonucleus in the cytoplasm of the oocyte. Up to now, however, most of the techniques that evaluate the functional state of the sperm cell have not been predictive, and the only feasible and repeatable means of evaluating the fertilizing power of a semen is fertilization in vitro.

Fertilization↗
PubMed1993

Treatment of human spermatozoa with follicular fluid can influence lipid content and motility during in vitro capacitation.

In order to evaluate the role of human follicular fluid (HFF) on the fertilizing capacity of spermatozoa, we studied the effect of HFF on the lipid composition and on the movement characteristics of human spermatozoa. Spermatozoa (spz) from normospermic patients were prepared with a discontinuous Percoll gradient and incubated in Ménézo B2 medium with or without a supplement of 20% HFF (HFF-Percoll spz and B2-Percoll spz respectively) for 2 and 24 h. After 2 h HFF incubation, percentage progressive motility, straight line velocity (VSL), and amplitude of lateral head displacement (ALH) were improved in HFF-Percoll spz as compared to B2-Percoll spz (P < or = 0.05). After a longer incubation period (24 h), lipid changes appeared in HFF-Percoll spz with lower levels of cholesterol (P = 0.02) and phospholipids (P = 0.05). No modification of the cholesterol/phospholipid ratio after 2 and 24 h of incubation in either B2-Percoll spz or HFF-Percoll spz was observed. Such decreases in lipid content of HFF-Percoll spz may be factors which could be taken into account as constituting part of membrane modifications during the capacitation process.

Body Fluids↗
PubMed1993

Delayed interval delivery in quadruplet pregnancy: a case report.

A case report of delayed delivery of a quadruplet pregnancy is presented. This quadruplet pregnancy resulted from in-vitro fertilization. To our knowledge, this case represents the first report of quadruplets delivered on three separate days using the technique of delayed interval delivery. All infants survived and are healthy 2 years later.

Adult↗