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Biomedical subjects

N Laufer

Publications and source records attributed to N Laufer.

At least 109 records · Page 6Linked to original sources
PubMed1991

[Fentanyl vs alfentanil anesthesia for in vitro fertilization].

In a prospective double-blind study, 36 women undergoing ultrasonically guided oocyte retrieval for in vitro fertilization (IVF) were examined. Anesthesia in 19 was based on alfentanil, up to 0.025 mg/kg and in 17, fentanyl, 0.0025 mg/kg. There were no significant differences between groups with regard to age, weight, duration of procedure and pregnancy rate. There were no complications aside from nausea and vomiting. Amnesia for the puncture and analgesia were always perfect. Induction was significantly shorter for alfentanil, 1.3 +/- 0.7 min, than for fentanyl, 3.4 +/- 2.2 (p less than 0.01). All who received fentanyl were drowsy at the end of the procedure, while those in the alfentanil group were fully awake and able to move from operating table to stretcher with minimal help. We therefore recommend alfentanil as the base for anesthesia for IVF.

Alfentanil↗
PubMed1991

The correlation between sperm cell morphology and fertilization after zona pellucida slitting in subfertile males.

OBJECTIVE: This work was undertaken to evaluate the correlation between sperm cell morphology and fertilization after zona pellucida slitting in subfertile males. DESIGN: Twenty-two couples who failed at least one in vitro fertilization attempt because of lack of oocytes fertilization underwent a zona-slitting micromanipulative procedure. A total of 245 oocytes were retrieved and inseminated by three different modes: 151 oocytes underwent micromanipulation, 2 were damaged, and the remaining 149 inseminated by the husband's sperm (group A). Fifty-five oocytes were not manipulated and inseminated by the husband's sperm (group B), and 39 oocytes were not manipulated and inseminated by a donor sperm (group C). RESULTS: Fertilization rates were 26.8%, 5.5%, and 53.8% in groups A, B, and C, respectively, and differed significantly between group A and group B. The cleavage rates were lower for oocytes fertilized by the husband's sperm (48.6%) than that obtained by donor (90%), suggesting a sperm factor contributing to this phenomenon. The procedure was most efficient in patients with a total motile sperm count after preparation of greater than or equal to 5 million and with either normal sperm morphology or defects localized to the acrosome or tail region only. Sperm with nuclear morphological abnormalities demonstrated a marked reduction in fertilization potential. CONCLUSION: It is concluded that the zona-slitting technique enhances fertilization of severely subfertile sperm, and its efficacy is affected by sperm morphology and a threshold concentration of motile cells.

Animals↗
PubMed1990

Ovarian response to exogenous gonadotropins during pregnancy.

Multiple ovarian follicles were successfully induced in a patient undergoing superovulation for a gamete intrafallopian transfer (GIFT) procedure despite the presence of an undiagnosed ectopic pregnancy. Midluteal gonadotropin releasing hormone agonist (GnRH-a) treatment should be coupled with mechanical contraception in the previous cycle in patients with patent tubes.

Adult↗
PubMed1990

Culture of human endometrial cells under polarizing conditions.

Glandular epithelial and stromal cells were isolated from human endometrial biopsies and cultured in a dual-chambered system (Millicell; Millipore, Bedford, Ma., USA) that provides access of the medium to both sides of a membrane coated with reconstituted basement membrane material (Matrigel; Collaborative Research Inc., Bedford, Ma., USA). Examination by electron microscopy revealed that the epithelial cells formed a polarized cuboidal-columnar monolayer on the Matrigel surface. The cells exhibited apical microvilli, basal nuclei, and numerous cytoplasmic structures consistent with a well-differentiated cytoplasm; they were joined basally by interdigitating processes and apically by tight junctions and desmosomes. In contrast, epithelial cells cultured in parallel on plastic dishes were flattened, had fewer microvilli and cytoplasmic structures, and no junctional complexes.

Basement Membrane↗
PubMed1989

Double transfer of embryos in in vitro fertilization, or is there a delayed receptivity of the endometrium?

Sixty-seven in vitro fertilization (IVF) patients who underwent ultrasonically guided oocyte pickup (OPU) after induction of superovulation with human menopausal gonadotropins were submitted to two different protocols of embryo transfer. In the first group of 33 patients, four to five embryos were transferred to the uterus 48 hr after OPU. In the second group of 34 patients two to three embryos were transferred at 48 hr after OPU and two other embryos were transferred after freezing and thawing 48 hr later (96 hr after OPU). The pregnancy rate achieved in the double embryo transfer (ET) protocol was significantly higher than in the single-ET protocol (32.4 vs. 18.2%, respectively; P less than 0.05).

Embryo Transfer↗
PubMed1989

Human follicular fluid protease and antiprotease activities: a suggested correlation with ability of oocytes to undergo in vitro fertilization.

Plasminogen activator activity was determined in human follicular fluids (FFs) obtained during in vitro fertilization procedures. The fibrinolytic activity of plasminogen activator was significantly higher in fluids from follicles that contained oocytes that were later found to fertilize in vitro (group F) as compared with fluids from follicles that contained oocytes that failed to fertilize (NF). To assess whether this difference in overt plasminogen activator activity reflects differences in conversion of an inactive, latent plasminogen activator to the active enzyme, the ability of exogenous trypsin to enhance plasminogen activation was measured. The plasminogen-dependent hydrolysis of the chromogenic substrate S-2444 in presence of trasylol (Bayer, Leverkusen, Germany) was taken as a measure of plasminogen activator activity in these experiments. No activity was found in untreated FFs, while exposure to trypsin resulted in emergence of marked plasminogen activator activity. In addition, FFs exhibited trasylol-sensitive chromogenic activity indicative of serine-protease activity. Both the plasminogen activator and serine-protease levels after tryptic activation were significantly higher in NF than in F samples. Thus, while F samples have most of their plasminogen activator in an active form, NF samples have most of their plasminogen activator in a latent, trypsin-activatable form. Follicular fluids also contain inhibitory activities toward plasmin and trypsin. The inhibition of these enzymes correlates positively with the latency of plasminogen activator. These results suggest a direct relationship between the ability of oocytes to fertilize and the overt to latent plasminogen activator activity ratios in the FFs.

Endopeptidases↗
PubMed1989

Successful microsurgical removal of a pronucleus from tripronuclear human zygotes.

We have microsurgically extracted a pronucleus from 11 tripronuclear human zygotes under two different experimental conditions. One group of six zygotes was incubated in cytochalasin D for 30 minutes before manipulation. The remaining five zygotes were manipulated without preincubation in cytoskeletal relaxing agents. When cytoskeletal relaxants were used, all six embryos survived manipulation and cleaved. One embryo arrested spontaneously at the two-cell stage; all others cleaved to at least four cells, and one embryo reached the advanced morula stage. Of the five eggs manipulated without prior cytochalasin D and colcemid treatment, none survived for more than 30 minutes after manipulation. In none of the tripronuclear eggs was it possible to definitely identify the male pronuclei. Because development was interrupted for karyotyping, it is likely that these embryos would have otherwise continued to develop to more advanced stages. These results indicate that it is possible to microsurgically "epronucleate" tripronuclear human zygotes and obtain further development and that use of cytoskeletal relaxants facilities this manipulative procedure. However, because epronucleated embryos have significant developmental potential, chromosome studies are needed to confirm complete removal of a male pronucleus before such techniques can be applied clinically.

Cytochalasin D↗
PubMed1989

In-vitro steroid production by human granulosa lutein cells in long-term cultures.

delta 4 and delta 5 pathway steroidogenesis by human granulosa lutein cells (GLC) in long-term cultures (6-8 days) was investigated under basal (10% serum + medium + GLC) and stimulated (human chorionic gonadotropins (hCG), 100 mIU/ml) conditions. In the delta 4 pathway, 17-hydroxyprogesterone (17-OHP) secretion increased from 160-fold at 48 hours of culture to 360-fold at 144 hours under basal conditions, when compared with the respective controls (concentrations in the 10% serum added to the medium) (p less than 0.005). HCG further augmented 17-OHP production significantly at 96, 144 and 192 hours of culture. Progesterone (P) secretion behaved similarly, and increased from 150-fold at 48 hours to 560-fold at 96 hours when compared with controls, being further stimulated by hCG. In contrast, androstenedione (A) secretion throughout the entire culture period increased only slightly (3-5-fold) under both basal and stimulated conditions, when compared with the respective controls. In the delta 5 pathway, the secretory pattern of 17-hydroxypregnenolone (17-OHPregn) and dehydroepiandrosterone (DHEA) was similar to that observed with A, and both steroids increased only slightly under basal and stimulated conditions, when compared with their respective controls. In conclusion, 17-OHP and P are secreted in very significant amounts during the entire culture period while 17-OHPregn, DHEA and A are secreted in extremely small amounts. These results demonstrate that the delta 5 pathway is inactive in long-term human GLC cultures while the delta 4 pathway is active in certain portions only.(ABSTRACT TRUNCATED AT 250 WORDS)

17-alpha-Hydroxypregnenolone↗
PubMed1989

Manipulating the follicular phase in IVF cycles: a comparison of two hMG stimulation protocols.

The results of two human menopausal gonadotropin (hMG) protocols of ovulation induction for in vitro fertilization (IVF) were compared. With the first protocol, 28 women (group 1) were treated with an hMG dosage which was increased stepwise. With the second, 30 women (group 2) were treated with a high dose of hMG for 2 days, then given a constant daily dose. The two groups were compared with regard to ovarian response, luteal phase and laboratory and clinical outcomes of IVF. They were comparable as regards the total number of hMG doses required, the number of large follicles (mean diameter greater than 15 mm) on day 0 (day of human chorionic gonadotropin (hCG) administration), serum estrogen (E2) and progesterone (P) levels throughout the cycle and IVF laboratory and clinical outcomes. They differed significantly (p less than 0.01) only in the number of secondary smaller follicles (mean diameter less than 15 mm) observed on day 0 (3.7 +/- 0.4 for group 1 and 5.3 +/- 0.4 for group 2). Manipulating the hMG dosage during the early-mid follicular phase does not affect follicular synchrony, the number of oocytes harvested and the number of embryos achieved.

Adult↗
PubMed1989

In vitro fertilization. Correlation of vaginal cytology and hormonal profile with success rates.

Cytologic parameters of the vaginal epithelium in 59 women undergoing in vitro fertilization-embryo transfer (ET) were correlated with plasma levels of 17-beta estradiol and progesterone on the oocyte pickup (OPU) and ET days. On the OPU day a late proliferative/late proliferative-early secretory pattern was observed in 84.6% of the 13 women who conceived (group 1) but in only 52% of the 46 who failed to conceive (group 2) (P less than .04). On the ET day a secretory phase appeared in 100% and 61% of group 1 and 2 patients, respectively (P less than .01). Between the OPU and ET days the mean karyopyknotic index dropped by 60% and 13% in group 1 and 2 patients, respectively (P less than .001). It seems that a high estrogenic effect followed by an advanced progestational environment, on the OPU and ET days, respectively, can provide a favorable milieu for implantation.

Embryo Transfer↗
PubMed1989

Assisted reproductive technology. A clinical appraisal.

With the various types of reproductive technology now available, the overall pregnancy rates still are less than 25%. An increase in those rates would permit physicians to provide relief from infertility to a much larger population.

Embryo Transfer↗
PubMed1988

Comparison of magnetic resonance imaging and ultrasound in evaluating follicular and endometrial development throughout the normal cycle.

A prospective study was undertaken to evaluate and compare magnetic resonance imaging (MRI) and ultrasound (U/S) in monitoring follicular and endometrial development during the normal menstrual cycle. Results of MRI, U/S, estradiol (E2), and progesterone were obtained from five ovulatory volunteers on days 4, 8, 12, 16, 20, and 24 of the cycle. On U/S, all the women had only one dominant follicle, whereas MRI was able to detect a secondary cohort of follicles in three of five volunteers. Endometrial development on U/S and MRI showed similar patterns of growth with an increase on MRI from 5.8 +/- 1.1 mm on day 4 to a mean peak of 10.3 +/- 1.7 mm on day 24. A distinct feature of MRI was the demonstration of a junctional zone (JZ), which has a pattern of growth that resembles that of the endometrium, with accelerated growth from day 8 to day 16 (5.1 +/- .7 mm to 6.7 +/- .7 mm). The JZ corresponds anatomically to the distribution of the arcuate vessels and may therefore represent changes in blood supply to the endometrium. MRI, similar to U/S, is noninvasive and does not involve any radiation exposure but provides new information on uterine changes in the normal cycle. At present, its clinical applications are limited.

Adult↗
PubMed1988

Fertilization of human oocytes by sperm from infertile males after zona pellucida drilling.

Infertile couples who had failed to achieve fertilization of oocytes in previous trials of in vitro fertilization (IVF) were treated by IVF with zona pellucida drilling. Zona drilling entails use of micromanipulation to introduce a gap in the zona pellucida either mechanically or by localized application of a zona solvent from a microneedle. Ten couples were treated, from whom 63 oocytes were recovered for manipulation. Sixteen eggs were denuded of the cumulus oophorus only, and the remaining 47 eggs were subjected to zona drilling. Of the 16 eggs denuded but not drilled, 4 (25%) were fertilized. Of the 47 oocytes drilled, 31 survived (67%) and 10 of the surviving eggs (32%) were fertilized. The polyspermy rate for drilled eggs that fertilized was high (5/10, 50%), and polyspermic eggs were often penetrated by more than two spermatozoa. The remaining five eggs fertilized after drilling were diploid fertilizations, and in three cases cleavage was followed by embryo transfer, although pregnancies were not obtained. These data indicate that zona drilling has the potential for establishing pregnancies in instances where treatment by standard IVF would fail. In addition, results indicate that the block to polyspermy in human eggs occurs at the level of the zona pellucida.

Female↗
PubMed1988

In vitro effects of clomiphene citrate on human endometrium.

Since cis-clomiphene citrate (CC) used for ovulation induction may affect embryo implantation during in vitro fertilization, direct effects of the drug on human endometrium were tested. Estrogenic and antiestrogenic effects were evaluated in vitro by measuring changes in prostaglandin (PG) output provoked by estradiol (E2), CC, and mixtures of E2 and CC; progestagenic effects were tested with E2 17 beta-dehydrogenase activity and glycogen accumulation as end points. In secretary endometrium, 10(-6)M CC about doubled the basal output of PGF2 alpha and PGE2; 10(-8)M E2 increased the production of these PGs 3-fold and 1.8-fold, respectively. The effects of E2 at this concentration were not diminished by the addition of CC, even at 100-fold molar excess, under conditions in which 10(-7)M progesterone or 10(-6)M 4-hydroxytamoxifen suppressed completely the action of the natural estrogen. In proliferative endometrium, 10(-8)M and 10(-6)M CC had no consistent effect on E2 17 beta-dehydrogenase activity or glycogen accumulation. These results demonstrate that, under in vitro conditions, CC can exert direct estrogenic effects on the endometrium but does not act as an antiestrogen or a progestagen.

Clomiphene↗
PubMed1988

Percutaneous transluminal coronary angioplasty improves survival in acute myocardial infarction complicated by cardiogenic shock.

Modest survival benefits have been reported in patients with acute myocardial infarction complicated by cardiogenic shock who were treated with early surgical revascularization or thrombolytic therapy. To determine whether coronary angioplasty improves survival, 87 patients with cardiogenic shock complicating acute myocardial infarction at the University of Michigan, Ann Arbor, Michigan, from 1975 to 1985 were retrospectively analyzed. Patients in group 1 (n = 59) were treated with conventional therapy; patients in group 2 (n = 24) were treated with conventional therapy and angioplasty. Extent of coronary artery disease, infarct location, and incidence of multivessel disease were similar between groups. Hemodynamic variables including cardiac index, mean arterial pressure, and pulmonary capillary wedge pressure were also similar. The 30-day survival was significantly improved for group 2 patients (50% vs. 17%, p = 0.006). Survival in group 2 patients with successful angioplasty was 77% (10 of 13 patients) versus 18% (two of 11 patients) in patients with unsuccessful angioplasty, (p = 0.006). The findings suggest that angioplasty improves survival in cardiogenic shock compared with conventional therapy with survival contingent upon successful reperfusion of the infarct-related artery.

Angioplasty, Balloon↗