Biomedical subjects

G D Palermo

Publications and source records attributed to G D Palermo.

49 records · Page 3Linked to original sources

PubMed1996

Intracytoplasmic sperm injection: a powerful tool to overcome fertilization failure.

OBJECTIVE: To describe the novel micromanipulation technique known as intracytoplasmic sperm injection (ICSI), which has been applied successfully to treat male factor infertility, even in patients with severely impaired sperm characteristics. This paper reviews the historical aspects that led to the development of ICSI in the animal model as well as the current experience in the human. DESIGN: Before using assisted fertilization techniques to enhance fertilization of human gametes, it is imperative that practitioners gain extensive experience in the animal model. In addition, criteria for accepting individuals for treatment with ICSI are discussed along with other applications of the procedure in infertile couples who do not benefit from standard IVF. RESULTS: Because ICSI resulted in limited success in animal models, it seemed unlikely that it would be successful in humans. Yet, ICSI now appears to be the most successful and significant innovation developed for dealing with male factor infertility since the emergence of IVF itself. To date, a relatively large group of healthy children have been born from this technology and there appears to be no increased incidence of congenital malformations. CONCLUSIONS: The consistently high success rate resulting from the application of ICSI to treat couples with male factor infertility is comparable to the results obtained using standard IVF techniques performed in nonmale factor couples. This finding indicates that spermatozoa obtained from subfertile men selected for intracytoplasmic injection are usually genotypically normal.

Animals↗

PubMed1996

Oolemma characteristics in relation to survival and fertilization patterns of oocytes treated by intracytoplasmic sperm injection.

The aim of this study was to analyse the various reactions displayed by the oolemma to the penetrating pipette during intracytoplasmic sperm injection (ICSI) and correlate them with clinical factors, oocyte survival and fertilization patterns. Three types of oolemma responses were observed: normal breakage, when the injection needle created an invagination that ruptured at the approximate centre of the egg; sudden breakage, when the membrane broke without creating a funnel; and difficult breakage, when the membrane did not break or broke after several penetration attempts. A total of 2928 oocytes were analysed with the following observations: 73.9% (n = 2164) experienced normal breakage, 11.8% (n = 345) sudden breakage, and 14. 3% (n = 419) difficult breakage. The survival rate and number of normally fertilized oocytes were significantly lower and the incidence of digynic oocytes was significantly higher in the sudden breakage group; furthermore, in this group a significantly shorter length of stimulation was observed along with lower serum oestradiol concentrations when compared to oocytes experiencing normal and difficult breakage patterns. These recorded patterns were predictive of the survival and fertilization ability of the injected oocytes, as well as the incidence of digyny. The link between membrane behaviour and various clinical parameters appears to indicate a correlation between the modality of stimulation and oolemma characteristics.

Cell Membrane↗

PubMed1996

Aggressive sperm immobilization prior to intracytoplasmic sperm injection with immature spermatozoa improves fertilization and pregnancy rates.

This study was conducted to determine whether the mode of sperm immobilization prior to intracytoplasmic sperm injection (ICSI) influences fertilization by immature spermatozoa. Of the 837 ICSI cycles evaluated, 81 were performed with epididymal or testicular spermatozoa; 35 cycles with epididymal spermatozoa immobilized in the standard fashion resulted in fertilization and pregnancy rates of 48.3 and 51.4% respectively. When a more aggressive sperm immobilization technique (i.e. permanently crimping the sperm flagellum between the midpiece and the rest of the tail) was applied in 17 cycles, the resultant fertilization and pregnancy rates were significantly (P < 0.05) higher: 82.0 and 82.4% respectively. Similar increases in fertilization and ensuing pregnancy rates were also observed in ICSI cycles with the aggressive immobilization of frozen-thawed epididymal spermatozoa (eight cycles) versus standard immobilization (16 cycles). However, the fertilization rates for ICSI using testicular spermatozoa (five cycles) were basically the same, regardless of the immobilization technique. Furthermore, for ejaculated spermatozoa (756 cycles), the fertilization rates following aggressive sperm immobilization were also positively affected (73.4%), although no statistical differences in the clinical pregnancy rates were found. Because aggressive immobilization appears to affect sperm membrane permeabilization, the enhanced fertilization patterns observed in immature spermatozoa following aggressive immobilization may suggest a different membrane constitution in these spermatozoa. These findings indicate that immature gametes may require additional manipulation to enhance the post-ICSI events essential for adequate nuclear decondensation.

Adult↗

PubMed1995

Intracytoplasmic sperm injection: a novel treatment for all forms of male factor infertility.

OBJECTIVE: To demonstrate the effectiveness of intracytoplasmic sperm injection to treat male factor infertility and to report on the achievement of fertilization and pregnancy compared with standard in vitro insemination. DESIGN: Controlled clinical study. SETTING: Couples suffering from male factor infertility treated in an academic research environment. PATIENTS: Two hundred twenty-seven couples in whom the male partners were presumed to be the cause of repeated failed attempts at IVF or whose semen parameters were unacceptable for conventional IVF. INTERVENTIONS: Oocytes for this study were harvested after superovulation with GnRH agonist and gonadotropins. After removing the cumulus cells, a single spermatozoon was injected directly into the cytoplasm of metaphase II oocytes, and the outcome was analyzed in terms of semen parameters and origin of semen sample. MAIN OUTCOME MEASURES: Fertilization and pregnancy rates (PRs) in relation to sperm parameters and origin of semen sample. RESULTS: Two hundred twenty-seven couples were treated by intracytoplasmic sperm injection resulting in an ongoing pregnancy rate of 37.0% per retrieval (84/227). There were 47 singleton pregnancies (5 of which were vanishing twin pregnancies), 30 twin gestations, 6 triplet pregnancies, and 1 quadruplet pregnancy. The concentration of the total motile spermatozoa present in the ejaculate as well as the origin of the samples influenced the fertilization rate but not the pregnancy outcome. CONCLUSIONS: Intracytoplasmic sperm injection can be used successfully to treat couples who have failed IVF or who have too few spermatozoa for conventional methods of in vitro insemination. Sperm parameters do not clearly affect the outcome of this technique.

Adult↗

PubMed1995

Cystic fibrosis gene mutations do not affect sperm function during in vitro fertilization with micromanipulation for men with bilateral congenital absence of vas deferens.

OBJECTIVE: To assess the effects of cystic fibrosis transmembrane-conductance regulator (CFTR) gene mutations on sperm function and fertility in men with bilateral congenital absence of the vas deferens. DESIGN: Prospective. SETTING: Division of urologic microsurgery and associated hospital-based IVF unit. MAIN OUTCOME MEASURES: Fertilization and pregnancy rates. PATIENTS: Men referred to our fertility unit for treatment of bilateral congenital absence of the vas deferens, using sperm surgically retrieved from the epididymis with IVF and micromanipulation. RESULTS: Of 45 men with bilateral congenital absence of the vas, 54% (19/35) tested were found to be carriers of CFTR gene mutations, with one compound heterozygote. Epididymal sperm from men affected with CFTR mutations fertilized 19% (29/152) of oocytes, whereas men without mutations fertilized 22% (44/204) of oocytes. Pregnancy rates (PRs) were 36% (5/14) for cycles involving men with CFTR mutations and 33% (5/15) for other patients with congenital absence of the vas deferens but without detectable CFTR mutations. CONCLUSIONS: The presence of detectable CFTR mutations does not affect fertilization rates or PRs for men with bilateral congenital absence of the vas deferens when IVF and micromanipulation are applied.

Cystic Fibrosis↗

PubMed1995

Micropuncture retrieval of epididymal sperm with in vitro fertilization: importance of in vitro micromanipulation techniques.

OBJECTIVES: To evaluate the importance of in vitro micromanipulation techniques, specifically intracytoplasmic sperm injection (ICSI), for the fertility treatment of men with congenital absence of the vas deferens (CAV) or other unreconstructable male reproductive tract obstruction. METHODS: Results using ICSI during in vitro fertilization (IVF) were compared to previously published results of IVF alone and IVF with other micromanipulation techniques at the same infertility center. Main outcome parameters evaluated were: fertilization rate per oocyte, clinical pregnancy rate, and ongoing pregnancies and deliveries. RESULTS: IVF with ICSI yielded a fertilization rate per oocyte of 140 of 312 (45%) and a clinical pregnancy rate of 14 of 27 (52%) per cycle of sperm and egg retrieval. Ongoing pregnancies or deliveries have occurred for 13 of 27 (48%) cycles with ICSI. These results were better than our previously published results of IVF alone or in conjunction with the micromanipulation techniques of subzonal insertion (SuZI) or partial zona dissection (PZD) that yielded a 119 of 631 (19%; P < 0.0001) fertilization rate, clinical pregnancy rate of 14 of 51 (27%; P < 0.001) and ongoing pregnancy or delivery for 12 of 51 cycles (24%; P < 0.001). CONCLUSIONS: Epididymal sperm retrieval should be performed only when micromanipulation is available in conjunction with IVF to maximize chances of fertilization and subsequent pregnancies. The use of ICSI for epididymal sperm appears to maximize chances of pregnancy for couples with surgically unreconstructable obstructive male infertility.

Cytoplasm↗

PubMed1995

Development and implementation of intracytoplasmic sperm injection (ICSI).

The purpose of this paper is to elucidate the experimental steps that led to the development of intracytoplasmic sperm injection (ICSI) and its application in the human. ICSI has become the most successful micromanipulation procedure for treating male infertility. A total of 355 in vitro fertilization (IVF) cycles utilizing ICSI are described; 180 couples were previously treated in 509 IVF cycles but achieved no fertilization and 175 couples could not be treated by IVF because of extremely poor semen parameters. Of the 3063 metaphase II (M II) oocytes retrieved, 2970 were injected with a survival rate of 93.6%, yielding 1917 bipronuclear zygotes (64.5%). In 148 patients, a foetal heart was evidenced by ultrasound; 11 of these patients miscarried between 7 and 13 weeks of gestation. The ongoing pregnancy rate was 38.6% (137/355) per retrieval and 40.5% (137/338) per embryo replacement. At the time of writing, there were 22 deliveries and one therapeutic abortion for a trisomy 21 chromosomal abnormality. In addition, 66 singleton, 37 twin, 10 triplet and 1 quadruplet pregnancies were ongoing. The concentration of motile spermatozoa in the ejaculate only slightly influenced the fertilization rate (P < 0.001) and the pregnancy outcome (P < 0.01). A preliminary injection procedure utilizing intracytoplasmic injection of isolated sperm heads was performed in 35 M II human oocytes with resultant fertilization and cleavage rates of 74% and 73% respectively. Skills in ICSI were acquired by injecting hamster and unfertilized human oocytes with human sperm. ICSI can be used to successfully treat couples who have failed IVF or who have too few spermatozoa for conventional in vitro insemination.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1995

Chromosomal status of uni-pronuclear human zygotes following in-vitro fertilization and intracytoplasmic sperm injection.

Uni-pronuclear embryos (n = 42) were analysed by fluorescence in-situ hybridization (FISH) with two to four chromosome pair-specific probes. Half of these embryos resulted from conventional insemination and half from intracytoplasmic sperm injection (ICSI). The majority of uni-pronuclear embryos from conventional insemination were normally diploid (61.9%) whereas only 9.5% of uni-pronuclear ICSI embryos (P < 0.001) were diploid. In addition, a significantly higher number of uni-pronuclear embryos from conventional insemination had a Y chromosome (10/21, 47.6%) when compared with ICSI embryos (2/21, 9.5%) (P = 0.015). It is concluded that the majority of uni-pronuclear embryos following regular in-vitro fertilization are fertilized, whereas those from ICSI are parthenogenetically activated. The latter embryos should not be considered for embryo replacement.

Adult↗

PubMed1995

Genetics of abnormal human fertilization.

The purpose of this study was to assess the genetic status of abnormal zygotes following assisted fertilization. Dispermic, monopronucleated and digynic zygotes were allowed to cleave intact or after enucleation, and on the biopsied blastomeres, multiplex polymerase chain reaction and fluorescent in-situ hybridization were performed. It was found that the distal pronucleus was usually male in origin in dispermic embryos, and that the sex ratio was restored when they were enucleated; however, they became mosaic at metaphase and their genetic heterogeneity was not restored after enucleation. Monopronucleated zygotes derived from standard in-vitro insemination can be transferred to the patient, since they usually showed normal diploid complement in their cells. On the contrary, single-pronucleated zygotes derived from intracytoplasmic sperm injection were usually activated parthenogenetically, but not fertilized. Digynic embryos, unlike dispermic ones, had a very low incidence of mosaicism, and when present, such mosaicism originated at a later embryo division. Most of the digynic embryos were triploid, indicating that the first division was normal and bipolar; moreover, when the female pronucleus was removed, they became diploid and their genetic status was considered normal. The recognition and understanding of fertilization abnormalities allow the identification of methods leading to their avoidance or correction.

Blastomeres↗

PubMed1995

Enhancement of fertilization by micromanipulation.

Micromanipulation techniques have been successfully applied to human gametes to assist fertilization when normal function is impaired. The past few years have witnessed the rapid evolution and clinical incorporation of this technology. The unprecedented efficiency of intracytoplasmic sperm injection far surpasses all previous methods. This method has thus become the best treatment option for many forms of male infertility.

Adult↗

PubMedDate not supplied

Comparison of centrifugation- and noncentrifugation-based techniques for recovery of motile human sperm in assisted reproduction.

To compare standard density gradient centrifugation sperm preparation with a novel non-centrifugation-based dual-chamber capillary dish in efficiency for motile human sperm separation, approximately 3 mL fresh ejaculate specimens was obtained from 21 men (median age = 32 years. range 26-42 years) undergoing infertility evaluation. For each specimen, half of the sample was processed with a standard 45%/90% density gradient preparation (PureSperm. Nidacon International, Gothenburg, Sweden) followed by semen analysis. The other half was incubated in the Zech glass capillary dish (Astromedtec, Salzburg, Austria) consisting of 2 concentric wells overlaid by a U-ring and coverglass. After approximately 3 h, a 1-mL sample was taken from the central chamber and analyzed. Percentage motile sperm recovery, absolute (motile) cell number, and path velocities were compared for spermatozoa obtained from both methods. Both techniques reduced overall sperm concentration while enriching specimens with more motile spermatozoa. A trend towards higher % recovery of motile spermatozoa (p = .264) was observed with the Zech device, but at a cost of fewer absolute numbers of higher velocity cells (p = .004). The Zech device, therefore, localized a very small population of motile sperm without exposure to centrifugation stress, which has been considered potentially harmful to spermatozoa. This technique could theoretically improve efficiency by reducing time required to identify motile cells in in vitro fertilization where intracytoplasmic sperm injection is planned. However, refinements in incubation interval and suspension volumes are needed before this technique can be considered comparable to the density gradient method in recovering sperm for use in intrauterine insemination.

Adult↗

PubMedDate not supplied

IVF: the new era.

In-vitro fertilization (IVF) has made great strides in the past 25 years including the development of micromanipulation techniques. Intracytoplasmic sperm injection (ICSI) for treatment of severe male factor infertility paved the way for the use of the micromanipulator. Micromanipulation techniques are now an integral part of an IVF program and are now also employed to biopsy embryos from patients harboring genetic abnormalities. Micromanipulation has also been used in the development of nuclear transfer techniques--a potential solution for creating "younger" oocytes for women of advanced maternal age and spermatozoa for azoospermic men. Other recent developments include the sequential media enabling the embryo to survive to blastocyst stage and also successful oocyte vitrification to preserve future fertility. This paper describes the latest technologies in in-vitro fertilization and relates them to the total problem of infertility, age-related and otherwise.

Embryo Transfer↗

PubMedDate not supplied

Indications for corticosteroids prior to epididymal sperm retrieval.

OBJECTIVE: To evaluate the effectiveness of low-dose intermittent prednisone treatment designed to reduce antisperm antibodies for men prior to epididymal sperm retrieval and in vitro fertilization. STUDY DESIGN: This was a retrospective review of 75 subfertile men with reproductive obstruction due to congenital absence of the vas deferens, or other reproductive tract obstruction, who underwent a total of 98 episodes of microsurgical epididymal sperm aspiration (MESA) with in vitro fertilization. RESULTS: For couples in whom the man was pretreated with prednisone, better fertilization rates (39% vs. 21%, P < .0001) and pregnancy rates (48% vs. 26%, p = 0.06) were obtained than in couples in whom the man was not pretreated. The benefit of prednisone treatment was most noticeable for men with preoperatively detectable antisperm antibodies. Prednisone-treated men with preoperative antisperm antibodies showed improved fertilization rates (40% vs. 9%, p = 0.005). Men without antibodies who were treated with prednisone showed a decrement in fertilization rate, from 73% to 24% (fertilizations per oocyte, P < .0005). Success of prednisone treatment could not be correlated with specific assisted-reproduction technique (IVF, PZD, SuZI, or ICSI). CONCLUSIONS: Preoperative evaluation of antisperm antibody status and treatment of antibody-positive men prior to epididymal sperm retrieval may play a role in improvement of the fertilization and pregnancy results achieved by centers that provide MESA with assisted reproduction. These results are most important when MESA is performed without the assistance of intracytoplasmic sperm injection. Empiric treatment with prednisone may be detrimental to the fertility of men who have no antisperm antibodies.

Adult↗