Biomedical subjects

S M Lobel

Publications and source records attributed to S M Lobel.

10 recordsLinked to original sources

PubMed2000

Bleeding and spontaneous abortion after therapy for infertility.

OBJECTIVE: To determine the incidence of early-pregnancy bleeding and spontaneous abortion (SAB) after various treatments for infertility and to assess whether bleeding is predictive of SAB. DESIGN: An historic cohort study of women who conceived after various treatments. SETTING: Hospital-based private practice. PATIENT(S): We studied 418 patients in whom 500 consecutive clinical pregnancies occurred. INTERVENTION(S): Patients were grouped according to the method of conception: ovulation induction, IVF, and other. The latter category included interventions not requiring ovulation induction, such as surgery and insemination. A fourth group of subjects who conceived independently of treatment was used as the control. MAIN OUTCOME MEASURE(S): Bleeding and pregnancy outcome (SAB, ectopic pregnancy, or ongoing pregnancy). RESULT(S): Rates of SAB did not differ among the treatment groups. SAB occurred significantly more often after bleeding than when bleeding did not occur (30.8% versus 19.8%, respectively). Bleeding was predictive of SAB only in patients <35 years old (odds ratio 2.4). CONCLUSION(S): Infertile women who conceive after reproductive therapy are not at increased risk for SAB compared with women who conceive naturally. There appears to be no association between previous diagnosis or treatment and the occurrence of SAB in previously infertile women. Bleeding is associated with a twofold relative risk of SAB.

Abortion, Spontaneous↗

PubMed1996

Efficacy of intracytoplasmic sperm injection using intentionally cryopreserved epididymal spermatozoa.

Microsurgical epididymal sperm aspiration was a great advance in the therapy of patients with non-reconstructable, obstructive azoospermia, most notably congenital bilateral absence of the vas deferens. Using conventional in-vitro fertilization, pregnancies were rarely achieved because the rate of oocyte fertilization was extremely poor. However, the use of retrieved spermatozoa in conjunction with intracytoplasmic sperm injection (ICSI) has dramatically increased the likelihood of embryo formation. Typically, sperm and oocyte harvesting are performed simultaneously. We have investigated whether frozen-thawed spermatozoa work as well as fresh spermatozoa. When we had concluded from our own population of patients (groups I and II) that they did, we adopted a policy of aspirating spermatozoa, primarily cryopreserving them and using them for ICSI at a later date. We found the fertilization rates of this latter cohort of patients (group III) to be excellent (37% per oocyte), and the ongoing pregnancy rate is quite satisfactory (40% per couple, 29% per cycle). We offer this approach as an alternative to the traditional scheme because it markedly eases the burden of partner scheduling on both the couple and the clinicians involved. In addition, assurance of the availability of male partner spermatozoa can be attained prior to beginning ovulation induction.

Adult↗

PubMed1995

Gonadotropin-releasing hormone antagonist versus agonist administration in women undergoing controlled ovarian hyperstimulation: cycle performance and in vitro steroidogenesis of granulosa-lutein cells.

OBJECTIVES: We sought to determine the effectiveness of a gonadotropin-releasing hormone antagonist compared with an agonist in suppressing a spontaneous luteinizing hormone surge in women undergoing controlled ovarian hyperstimulation for in vitro fertilization and gamete intrafallopian transfer and to examine whether in vivo administration of these analogs effects granulosa-lutein cells steroidogenesis in vitro. STUDY DESIGN: This prospective case-control study included 30 healthy women undergoing ovarian hyperstimulation with human menopausal gonadotropins. Fifteen women received the Nal-Glu antagonist, 5 mg intramuscularly daily, when the lead follicle was > or = 15 mm or serum estradiol level was > or = 500 pg/ml. The control group included 15 women who underwent oocyte retrieval on the same day as the study subjects and were given the agonist leuprolide acetate, 250 micrograms subcutaneously daily, starting on cycle day 1. Granulosa-lutein cells were purified from follicular aspirates from six subjects and six controls and cultured in parallel, evaluating basal progesterone production, progesterone response to follicle-stimulating hormone or luteinizing hormone and aromatase activity. RESULTS: No difference was demonstrated in the total amount of gonadotropins received by the two groups. Overall, the gonadotropin-releasing hormone antagonist was given for only 2.5 +/- 0.2 (mean +/- SEM) days before human chorionic gonadotropin administration. The antagonist group showed significantly lower levels of serum luteinizing hormone than did the agonist group, 1.0 +/- 0.2 versus 4.2 +/- 0.5 mIU/ml (p = 0.0001) on the day of human chorionic gonadotropin administration. Serum estradiol levels were significantly lower in the antagonist than the agonist group, 820 +/- 120 versus 1361 +/- 110 pg/ml (p = 0.003) on the day of human chorionic gonadotropin administration. There was no difference in the number of retrieved oocytes, but the antagonist group had a higher proportion of mature oocytes, 82% +/- 4% versus 62.4% (p = 0.02), and a higher proportion of embryos of good quality, 69.8% +/- 9.8% versus 44.3% +/- 7.2% (p = 0.03) in the agonist group. Granulosa-lutein cells from antagonist-treated women showed significantly lower aromatase activity the first 6 hours after retrieval, 17.6 +/- 1.6 versus 31.3 +/- 7.4 ng/ml per 6 hours estradiol (p = 0.03), whereas basal and gonadotropin-stimulated with progesterone responses were similar. CONCLUSION: Gonadotropin-releasing hormone antagonist administration during the late follicular phase resulted in lower serum luteinizing hormone and estradiol levels and more mature oocytes and embryos of better quality compared with gonadotropin-releasing hormone agonist administration. These results suggest that gonadotropin-releasing hormone antagonist administration in ovarian hyperstimulation has practical advantages over the agonist regimen. Gonadotropin-releasing hormone analogs may have direct action on ovarian function with differential effects on granulosa-lutein cell aromatase activity. This could explain the lower serum estradiol levels routinely observed in women given gonadotropin-releasing hormone antagonist.

Adult↗

PubMed1995

The achievement of pregnancies using assisted reproductive technologies for male factor infertility after retroperitoneal lymph node dissection for testicular carcinoma.

OBJECTIVE: To evaluate the success of electroejaculation with assisted reproductive technologies (ART) in anejaculate men after retroperitoneal lymph node dissection (RPLND) for testicular cancer. DESIGN: Retrospective clinical study. SETTING: Tertiary care, university-affiliated IVF program. PATIENTS: Anejaculate men after RPLND, spouses. INTERVENTIONS: Electroejaculation, microsurgical sperm aspiration, various assisted reproductive technologies. MAIN OUTCOME MEASURES: Sperm density and motility, fertilization rate, pregnancy rate (PR). RESULTS: Compared with patients not receiving chemotherapy, patients who received chemotherapy had diminished average sperm densities and motilities (63 x 10(6) and 20% versus 101 x 10(6) 32%, respectively); decreased fertilization rates per cycle for IVF and intracytoplasmic sperm injection (ICSI) (11% versus 26%, respectively); lower PRs per cycle of hMG-IUI and IVF (14% versus 60% and 8% versus 50%, respectively). No pregnancies were achieved with natural cycle-IUI, clomiphene citrate-IUI, or GIFT. Two couples progressed to intracytoplasmic sperm injection with one achieving the successful delivery of healthy twins. The overall PR per cycle was 22%. CONCLUSIONS: Patients receiving chemotherapy had decreased sperm densities, motilities, fertilization, and PRs for each modality used. Rectal probe electroejaculation with ART can help anejaculate men after RPLND achieve biologic paternity. An early move to the more aggressive therapies (hMG-IUI, IVF, ICSI) is supported.

Adult↗

PubMed1993

Acute adrenocorticotropin stimulation of postmenopausal cigarette smokers and nonsmokers: effects on steroidogenesis.

Cigarette smoking has been associated with elevated levels of A and DHEAS in postmenopausal women. One possible mechanism postulated for this effect is enzymatic blockage by components of cigarette smoke. In this study, acute ACTH stimulation of postmenopausal cigarette smokers did not result in abnormal elevations of precursor steroids. Other possible mechanisms may be operative in vivo to account for the previously reported findings.

Adrenocorticotropic Hormone↗

PubMed1993

The sex ratio of normal and manipulated human sperm quantitated by the polymerase chain reaction.

OBJECTIVE: To establish the primary sex ratio, the relative abundance of X and Y chromosome-bearing sperm, in unselected sperm and in sperm selected by swim-up or Sephadex filtration (SpermPrep column; Fertility Technologies, Inc., Natick, MA). This was done to evaluate the possibility that these semen manipulations change the primary sex ratio. DESIGN: Ninety-eight unmanipulated semen samples were analyzed for sex chromosome content using quantitative polymerase chain reaction (PCR). A smaller number of samples was analyzed before and after either swim-up or Sephadex filtration. RESULTS: The mean percentage of all sex chromosomes identified as a Y chromosome in unmanipulated semen samples ranged from 41.9% to 56.7%, with a mean average of 50.3%. There was no significant change in sex chromosome composition after either swim-up (n = 17) or column filtration (n = 20). CONCLUSIONS: The chromosome compositions of semen samples from a large number of men have equal numbers of X and Y. Swim-up and SpermPrep filtration do not appear to alter the primary sex ratio.

Humans↗

PubMed1991

Preoperative uterine artery embolization in cervical pregnancy.

Cervical pregnancy often results in massive hemorrhage following curettage. Performance of uterine artery embolization before curettage is reported in three consecutive cases of cervical pregnancy. All patients had a successful outcome without significant hemorrhage.

Blood Loss, Surgical↗

PubMed1990

Efficacy and safety considerations in women with uterine leiomyomas treated with gonadotropin-releasing hormone agonists: the estrogen threshold hypothesis.

Gonadotropin-releasing hormone agonists induce a reversible hypogonadotropic hypogonadal environment. Leiomyomas are common, estrogen-sensitive, benign neoplasms that decrease in size by 40% to 50% during gonadotropin-releasing hormone agonist treatment. During gonadotropin-releasing hormone agonist therapy most women are amenorrheic. After discontinuation of gonadotropin-releasing hormone agonist treatment, uterine and myoma size increase and a return to pretreatment menstrual patterns often occurs. Concerns about the safety of long-term hypoestrogenism have made long-term gonadotropin-releasing hormone agonist administration an undesirable treatment strategy. This article focuses on the use of gonadotropin-releasing hormone agonists as preoperative therapy in selected women undergoing hysterectomy or myomectomy and the combination of a gonadotropin-releasing hormone agonist with estrogen-progestin "add-back" treatment as a potential long-term medical therapy for women with symptomatic leiomyomas. Finally, an estrogen threshold hypothesis to assess the effects of circulating estrogen concentrations on different tissues, is presented.

Buserelin↗

PubMed1990

Preoperative angiographic uterine artery embolization in the management of cervical pregnancy.

The diagnosis of a cervical ectopic pregnancy is often made intraoperatively in the presence of extensive hemorrhage during attempted evacuation. In some cases, hysterectomy has been the necessary treatment to control bleeding. We report two cases of cervical pregnancy detected by ultrasound. Before pregnancy termination, the uterine arteries were successfully embolized using angiographic techniques. As a result, surgical evacuation was performed with minimal hemorrhage; hysterectomy was not required and the patients' potential fertility was retained.

Abortion, Therapeutic↗

PubMed1981

Two chick embryonic adhesion systems: molecular vs tissue specificity.

We have investigated the adhesive properties of cells from several neural and nonneural chick embryonic tissues dissociated using modifications of the standard dissociation procedures employed routinely in this laboratory to obtain retinal cells. Each of these tissues (7-day optic tectum, retina, and heart, and 3.75-day limb bud) displayed both Ca++-dependent (CD) and Ca++-independent (CI) aggregation, the relative rates of which differed from tissue to tissue. In every case, cells prepared so as to display one mode of aggregation or the other cross-adhered readily to cells--regardless of tissue origin--displaying the same mode of aggregation. Cross adhesion was negligible between cells--even from the same tissue--prepared so as to display different modes of aggregation. Anti-retinal Fab molecules which inhibit selectively either the CI or CD aggregation of retina cells strongly inhibited the corresponding aggregation of optic tectum cells, but had no effect upon the aggregation (CI or CD) of heart cells. These results demonstrate the existence in the tissues examined of dual adhesion mechanisms similar in Ca++ dependence and recognition properties to those of the retina, but showing certain immunological distinctions from the latter. The immunological relationship among the adhesion mechanisms from the various tissues is under continuing investigation.

Animals↗