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Biomedical subjects

S Fishel

Publications and source records attributed to S Fishel.

At least 55 records · Page 3Linked to original sources
PubMed1992

Evaluation of 225 patients undergoing subzonal insemination for the procurement of fertilization in vitro.

OBJECTIVE: To evaluate subzonal insemination for the procurement of fertilization in infertile males. DESIGN: The spermatozoa of infertile males was used, where possible, for in vitro fertilization (IVF) and subzonal insemination with the same cohort of oocytes obtained from their partner. SETTING: An individual unit in a general hospital, Clinical Nomentana, Rome, Italy. PATIENTS: Males who had repeatedly failed to achieve conception in vitro by IVF or in whom seminal parameters were unacceptable for IVF were treated. INTERVENTIONS: Two hundred twenty-five transvaginal oocyte retrievals were performed. MAIN OUTCOME MEASURES: The incidence of fertilization, cleavage, and pregnancy was evaluated in relation to the numbers of spermatozoa injected and the individual spermatozoa parameters. RESULTS: Fertilization occurred in 39% of patients and 16% of eggs, and 12 clinical pregnancies were established. Fertilization increased with increasing numbers of spermatozoa injected. Fertilization with subzonal insemination was significantly greater (39%) than after in vitro insemination (6%) (P less than 0.0001). CONCLUSIONS: Subzonal insemination improved the incidence of fertilization in this series of patients, and a new classification of spermatozoa based on total motile count aided prognosis for fertilization.

Adult↗
PubMed1991

Presentation of six pregnancies established by sub-zonal insemination (SUZI).

Clinical trials were undertaken to evaluate sub-zonal insemination (SUZI) for the procurement of fertilization in infertile couples. We present here the six pregnancies resulting from this work. Insemination of multiple sperm was used, with a mean of 3.7 +/- 2.1 (SD) per oocyte. One hundred and thirty patients presented either with previous failures of fertilization in vitro and/or with severe seminal defects, including oligo-, astheno-, oligo-astheno- or necro-zoospermia. Forty-one (31.5%) patients achieved fertilization and 39 had replacement of conceptuses. Six patients achieved a pregnancy (4.6% overall, 15.4% per replacement), four have delivered and two have miscarried. The implantation rate was nine conceptuses from a total of 61 replaced (14.8%); and of the six women who conceived, nine of 11 replaced conceptuses implanted. Of the oocytes recovered, 539 were used for SUZI, of which 69 (12.8%) fertilized. Three singleton pregnancies resulted, two from patients having one conceptus replaced, the other from the replacement of three conceptuses. Two twin pregnancies were produced, both in patients having two conceptuses replaced. The sixth pregnancy, a triplet, occurred in a patient having three conceptuses replaced, one conceived after standard in-vitro fertilization (IVF), the other two after SUZI. Two sets of non-identical twins, both one male and one female, a singleton female and female (non-identical) triplets have been born, normal and healthy.

Adult↗
PubMed1991

The use of the GnRH analogue buserelin for IVF--does it improve fertility?

OBJECTIVE: To determine the effect of a short course of the GnRH analogue buserelin and human menopausal gonadotrophin (hMG), for ovarian stimulation in our IVF programme, on reproductive endocrinology and pregnancy rates compared with conventional clomiphene citrate and hMG treatment. DESIGN: Prospective randomized allocation to one of two ovulation stimulation regimens. SETTING: Fertility clinic. SUBJECTS: 373 infertile couples with various factors associated with their subfertility. All the women were less than 46 years of age and had normal menstrual cycles. INTERVENTION: The first group (n = 151) was given clomiphene citrate (CC) from days 2-6 of the menstrual cycle and hMG from day 5 onwards (CC/hMG). The second group (n = 222) was given buserelin from days 1-3 and hMG from day 2 (buserelin/hMG). MAIN OUTCOME MEASURES: Concentration of plasma luteinizing hormone (LH), oestradiol (E2) and progesterone, number of ovulatory follicles induced and the occurrence of pregnancy. RESULTS: Plasma LH, E2 and progesterone concentrations were reduced in the late follicular phase after buserelin/hMG compared with CC/hMG. Buserelin/hMG promoted the development of more follicles than CC/hMG. The overall pregnancy rate after buserelin/hMG was not significantly different from that following CC/hMG treatment. CONCLUSION: The chance of pregnancy is not improved by the short-term use of buserelin with hMG, provided adequate follicular phase management is maintained.

Adult↗
PubMed1990

Subzonal insemination for the alleviation of infertility.

Methods were developed to facilitate the use of subzonal insemination to achieve fertilization in vitro. A clinical trial was undertaken in those patients having previously failed to achieve fertilization by in vitro fertilization, and in those presenting with severe oligospermia/oligoasthenospermia. From 85 patients, 585 oocytes were obtained. Of these, 0.3% had been "activated" parthenogenetically in vivo, 369 (72%) at metaphase II underwent subzonal insemination, 15% were fertilized, and 0.5% had three pronuclei. Thirty-eight percent of the patients had fertilization with 36% having a replacement. One conceptus was replaced in 19 patients, two conceptus in 8 patients, and three in 4 patients. A twin and two singleton pregnancies were established.

Adult↗
PubMed1989

Evaluation of high vaginal insemination at oocyte recovery in patients undergoing in vitro fertilization.

The value of high vaginal insemination at the time of oocyte recovery for in vitro fertilization (IVF) has been assessed. A previous study reported a dramatic increase in the incidence of pregnancy in women after high vaginal insemination (53%) compared with those without insemination (23%). Of 306 patients undergoing IVF, 97 (32%) became pregnant and 20 (21%) miscarried. Those patients with tubal damage numbered 187. Sixty (33%) became pregnant and 10 (17%) miscarried. The data were assessed according to the numbers of conceptuses replaced, the age of the patient, and whether a spontaneous luteinzing hormone surge or human chorionic gonadotropin was a trigger for ovulation, each with a significant effect on the outcome of treatment. No significant effect of the use of high vaginal insemination was found.

Abortion, Spontaneous↗
PubMed1989

Generation of reactive oxygen species, lipid peroxidation, and human sperm function.

Recent studies have demonstrated that human spermatozoa are capable of generating reactive oxygen species and that this activity is significantly accelerated in cases of defective sperm function. In view of the pivotal role played by lipid peroxidation in mediating free radical damage to cells, we have examined the relationships between reactive oxygen species production, lipid peroxidation, and the functional competence of human spermatozoa. Using malondialdehyde production in the presence of ferrous ion promoter as an index of lipid peroxidation, we have shown that lipid peroxidation is significantly accelerated in populations of defective spermatozoa exhibiting high levels of reactive oxygen species production or in normal cells stimulated to produce oxygen radicals by the ionophore, A23187. The functional consequences of lipid peroxidation included a dose-dependent reduction in the ability of human spermatozoa to exhibit sperm oocyte-fusion, which could be reversed by the inclusion of a chain-breaking antioxidant, alpha-tocopherol. Low levels of lipid peroxidation also had a slight enhancing effect on the generation of reactive oxygen species in response to ionophore, without influencing the steady-state activity. At higher levels of lipid peroxidation, both the basal level of reactive oxygen species production and the response to A23187 were significantly diminished. In contrast, lipid peroxidation had a highly significant, enhancing effect on the ability of human spermatozoa to bind to both homologous and heterologous zonae pellucidae via mechanisms that could again be reversed by alpha-tocopherol. These results are consistent with a causative role for lipid peroxidation in the etiology of defective sperm function and also suggest a possible physiological role for the reactive oxygen species generated by human spermatozoa in mediating sperm-zona interaction.

Animals↗
PubMed1988

Endotoxins in culture medium for human in vitro fertilization.

Endotoxins were detected in a few batches of culture medium during the authors' human in vitro fertilization program. Two distinct levels of endotoxins were assayed: greater than 1 ng/ml and less than 1 ng/ml. The source of endotoxin was traced to culture media obtained from a reputable manufacturing company. The incidence of fertilization per patient was not significantly affected by the presence of endotoxins, but fertilization assessed on the overall number of oocytes was significantly reduced (53%) when endotoxin levels were greater than 1 ng/ml compared with an assay negative for endotoxins (66%) (P = 0.047). The percentage of oocytes cleaving after the observation of two pronuclei was not significantly different, but the degree of fragments observed in the conceptus was significantly more severe if the endotoxin level reached 1 ng/ml. In this investigation, the incidence of pregnancy was 8% when the endotoxin level was greater than 1 ng/ml, 30% if less than 1 ng/ml, and 32% if no endotoxins were detected. This study suggests that, although endotoxins may be present in the culture medium at a deleterious level of at least 1 ng/ml, fertilization and cleavage will be obtained, but there will be a significant increase in the incidence of conceptuses with cytoplasmic fragments; this may result in a reduction in the incidence of pregnancy.

Cells, Cultured↗