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Biomedical subjects

N Laufer

Publications and source records attributed to N Laufer.

At least 163 records · Page 9Linked to original sources
PubMed1984

Factors affecting sperm motility. IX. survival of spermatozoa in various biological media and under different gaseous compositions.

The role of various environmental conditions on sperm motility and their survival was investigated by incubating washed human spermatozoa in various biologic or artificial media and under different atmospheric compositions. When sperm were analyzed by the multiple exposure photography technique for objective motility determination, it was found that none of the investigated biologic media induced any immediate stimulatory effect on the tested spermatozoa. Exchange of seminal fluid between normal and oligoasthenospermic specimens did not reveal any beneficial or harmful effect on sperm motility. Sperm did not survive for more than 24 hours when kept in their original seminal fluid under any circumstances. The most favorable media tested for prolonged sperm survival were pure human umbilical cord serum or Ham's solution containing 0.5% human albumin. However, even in these media sperm did not survive much beyond 24 hours unless incubated in an atmosphere containing 5% CO2 or a triple mixture of 90% N2, 5% O2, and 5% CO2. Only under these circumstances could sperm stay alive, in some cases up to 5 days.

Carbon Dioxide↗
PubMed1984

The periovulatory and luteal phase of conception cycles following in vitro fertilization and embryo transfer.

The pattern of periovulatory and luteal phase levels of serum estradiol (E2) and progesterone (P) were compared between 8 conception and 28 nonconception cycles of patients undergoing in vitro fertilization (IVF). Ten additional women served as control subjects and did not undergo follicular aspiration. Follicle growth was induced with an individualized Pergonal (human menopausal gonadotropin) regimen, and laparoscopy was performed 36 hours after human chorionic gonadotropin administration. The length of the luteal phase did not differ significantly among the three groups and was between 14 and 15 days in duration. When IVF conception cycles were compared with nonconception cycles, although no difference in the number of large follicles was observed (4.25 +/- 0.45 versus 3.6 +/- 0.25), the patterns of E2 and P differed significantly. Daily serum E2 levels tended to be higher in the periovulatory phase in conception cycles when compared with nonconception cycles, and were significantly (P less than 0.05) higher in the early, mid, and late luteal phases. Serum P levels were significantly higher (P less than 0.05) in conception cycles from the midluteal phase onward. A decline in both serum E2 and P in the midluteal phase in conception cycles suggested some degree of corpus luteum deficiency. It is suggested that high E2 levels in the periovulatory phase may be an indicator of better follicular development under human menopausal gonadotropin stimulation and that the deficiency observed in the late luteal phase is overcome with the establishment of pregnancy.

Adult↗
PubMed1984

The relationship between follicular fluid steroid concentration and successful fertilization of human oocytes in vitro.

Follicular fluids (FF) and their matched oocytes were obtained from 64 follicles of 28 women who failed to conceive after in vitro fertilization ( IVF ) and 33 follicles of 8 women who successfully conceived after the procedure. Ovulation was induced with human menopausal gonadotropin, and follicular aspiration was performed 36 hours after human chorionic gonadotropin administration. The concentration of 17 beta-estradiol, progesterone, testosterone, dihydrotestosterone, and androsterone was correlated with the morphology of the oocyte-corona-cumulus complex ( OCCC ), oocyte fertilization, the rate of cleavage, and the incidence of pregnancy after embryo transfer. In both groups of women, FF progesterone was lowest in follicles containing immature OCCCs . However, follicles aspirated from women who conceived after IVF which contained intermediate and mature OCCCs had significantly higher FF estradiol levels than similar follicles from women who failed to conceive after the procedure. Fertilized oocytes and 4- to 6-cell stage embryos which were obtained from follicles of pregnant women contained significantly higher FF estradiol levels than fertilized oocytes and similar embryos from nonpregnant women. It appears that higher FF estradiol levels correlate well with successful fertilization and an enhanced cleavage rate of oocytes associated with pregnancy following IVF .

Adult↗
PubMed1984

Delaying human chorionic gonadotropin administration in human menopausal gonadotropin-induced cycles decreases successful in vitro fertilization of human oocytes.

Correct timing of human chorionic gonadotropin (hCG) administration in induced cycles for in vitro fertilization is of crucial importance to oocyte maturation and normal luteal function. The purpose of this work was to compare the effect of hCG timing on follicular development, oocyte maturation, and fertilization in vitro, as well as on the pattern of luteal phase hormone secretion. Ovulation was induced in 32 normally cycling women by human menopausal gonadotropin (hMG)/hCG administration. In the first group (17 women) 10,000 IU hCG was administered 24 hours after the last injection of hMG and in the second group (15 women) 48 to 72 hours after the last hMG injection. Serum estradiol levels prior to oocyte aspiration were similar in both groups, as were the numbers of large follicles on the day of hCG administration (4.5 +/- 2.3 versus 4.1 +/- 1.9 follicles/woman, respectively). The distribution of oocyte-corona-cumulus complexes was similar in both groups and was comprised of 11% immature, 43% intermediate, and 45% mature complexes. The fertilization rate, however, was significantly (P less than 0.001) reduced in the group treated by delayed hCG injection (57% versus 84%), and the percentage of degenerated oocytes was increased (9% versus 1%). Luteal phase length as well as progesterone and estradiol levels were comparable in both groups. It is concluded that an interval longer than 24 hours between the last injection of hMG and the administration of an ovulatory dose of hCG does not affect follicular and luteal phase serum steroid patterns but may result in a decreased oocyte fertilization rate, possibly due to atretic changes in the follicles.

Adult↗
PubMed1984

Asynchrony between human cumulus-corona cell complex and oocyte maturation after human menopausal gonadotropin treatment for in vitro fertilization.

One hundred seventeen oocyte-cumulus-corona cell complexes (CCCs) were obtained from 15 women undergoing in vitro fertilization after human menopausal gonadotropin/human chorionic gonadotropin follicular stimulation. In each woman, five oocyte-CCCs were left intact, and the remaining one to five oocytes were freed of their CCCs by hyaluronidase (300 IU/ml) dispersal treatment. Dispersal time for individual CCCs correlated well with their degree of mucification and was significantly shorter in 20 mature CCCs as compared with 24 intermediate CCCs (1.20 +/- 0.05 versus 2.35 +/- 0.13 minutes, respectively; P less than 0.001). Oocyte maturation at collection and after 8 hours of in vitro incubation was not related to the CCC type present at harvest. Maturation of oocytes progressed regardless of CCC type; so that after 8 hours of preincubation, 73% of the oocytes attained a polar body while 20% were still at the germinal vesicle breakdown stage and 7% at the germinal vesicle stage. Overall, the 44 denuded oocytes and 72 intact oocyte-CCCs were comparable in rate of fertilization (64% versus 68%) and subsequent cleavage (75% versus 82% of all fertilized oocytes). It is concluded that in human menopausal gonadotropin-stimulated cycles, asynchrony between individual CCC mucification and oocyte maturation may occur, and that the absence of CCC does not seem to affect in vitro fertilization and cleavage rates.

Adult↗
PubMed1984

Fallopian tubal mucosal damage induced experimentally by Escherichia coli in the rabbit. A scanning electron microscopic study.

Pelvic inflammatory disease is the main cause of infertility due to a tubal factor. The importance of Gramnegative bacteria as major infecting organisms in pelvic inflammatory disease has been recently recognized. The predominant facultative pathogen found in tuboperitoneal fluid from women with salpingitis are coliform bacteria. This study describes an animal model for E. coli mediated tubal mucosa damage. E. coli (10(5)-10(9) bacteria 1 ml) was injected into the right Fallopian tube of sixty rabbits; the left tube injected with culture medium, served as a control. The luminal surface of the oviducts was examined by scanning electron microscope at various intervals after the injection. The degree of damage was found to be dose-dependent and maximal seven days after innoculation. The injury comprised of large areas of deciliation, severely shortened cilia, swollen and adherent throughout their entire length and disappearance of microvilli from the secretory cells. A process of regeneration began two weeks after the innoculation and was completed eight weeks later. Fertility studies carried out after completion of regeneration showed no difference in the ratio of corpora lutea/gestational sacs between the treated and control sides of individual pregnant animals. This model sheds light on the pathogenesis of tubal surface injury by E. coli and suggests that the major effects described are mediated through the endotoxin liberated from the cell wall of these bacteria and that, therefore, antibiotic treatment has no effect on the magnitude of injury. Endosalpingeal regeneration correlates well in this animal model with normal fertility suggesting that morphologic integrity of the surface epithelium may be a good criterion in assessing the reproductive capacity of the fallopian tube.

Animals↗
PubMed1984

Effects of reperfusion on complete heart block complicating anterior myocardial infarction.

Two patients with complete heart block complicating extensive anterior myocardial infarction underwent late (greater than 40 hours) coronary reperfusion with angioplasty. One to one atrioventricular conduction was restored within minutes of reperfusion despite a lack of measurable ventricular muscle salvage as demonstrated by ventriculography 1 week later. The evidence favors reversible ischemia rather than extensive necrosis of the proximal conduction system as the mechanism of heart block in this subgroup of patients.

Adult↗
PubMed1984

Gonadotropin and prolactin levels in follicular fluid of human ova successfully fertilized in vitro.

Follicular fluid (FF) and oocytes were obtained from 94 follicles of 36 women for fertilization in vitro. Ovulation was induced with human menopausal gonadotropin, and follicular aspiration was performed 36 h after an ovulatory injection of hCG. The concentrations of immunoreactive hCG, FSH, and PRL were correlated with the degree of maturation of the oocyte-corona-cumulus complex mass (OCCC), fertilization, rate of cleavage, and the incidence of pregnancy after embryo transfer. Immature OCCC were derived from follicles that contained significantly lower levels of FSH than those from which intermediate and mature OCCC were derived (5.2 +/- 0.6 vs. 11.1 +/- 1.2 mlU/ml; P less than 0.05). FF from oocytes that were successfully fertilized contained higher levels of both hCG and FSH than FF surrounding oocytes that did not fertilize (136.7 +/- 8.7 vs. 108.5 +/- 10.3 mlU/ml hCG; 10.55 +/- 0.6 vs. 5.3 +/- 0.8 mIU FSH, respectively). There was no correlation between early embryonic growth rate and FF concentrations of FSH, hCG, and PRL. Ova reaching the two-cell stage 40 h after fertilization in vitro were associated with the same FF concentrations of FSH, hCG, and PRL as those that cleaved to the four-cell stage. The PRL concentration in FF was significantly higher in mature fertilized ova and in fertilized ova that were associated with a successful pregnancy. It is suggested that the intrafollicular concentration of FSH is associated with the degree of mucification of the OCCC, but FF levels of both FSH and hCG are associated with successful fertilization. High levels of PRL in FF were associated with successful pregnancy and may imply a role of this hormone in oocyte maturation.

Adult↗
PubMed1984

Steroid secretion by the human egg-corona-cumulus complex in culture.

Forty-five oocyte-corona-cumulus complexes ( OCCC ) were obtained from follicles of 13 women undergoing fertilization in vitro. Follicular growth was induced with human menopausal gonadotropin, and follicular aspiration was performed 36 h after an ovulatory injection of hCG. The maturation of these complexes was evaluated by the extent of cumulus mucification and corona cell dispersal. Three main morphological types were characterized: immature OCCCs (6), with a tight and compact corona-cumulus mass surrounding the oocyte; intermediate OCCCs (26), with a dispersed cumulus but only partly dispersed corona layer; and mature complexes (13) with complete dispersal of both cellular components. During a 24-h culture, progesterone secretion by intermediate and mature OCCCs was 30-fold higher (mean +/- SEM, 652 +/- 87 ng/ OCCC X 24 h) than immature OCCCs (19.6 +/- 3.5 ng/ OCCC X 24 h), while estradiol secretion was twice as high (3.8 +/- 1.1 vs. 1.2 +/- 0.6 ng/ OCCC X 24 h). Testosterone secretion was similar in all three types of OCCCs cultured (0.30 ng/24 h). It is suggested that the steroids produced by the OCCC may contribute to the local milieu of the fallopian tube.

Adult↗
PubMed1984

The association between granulosa cell aromatase activity and oocyte-corona-cumulus-complex maturity from individual human follicles.

The steroidogenic capability of granulosa cells isolated from 12 preovulatory human follicles was correlated with the stage of maturation of the corresponding oocyte-corona-cumulus-complex ( OCCC ). Individual follicles from human menopausal gonadotropin (hMG) stimulated cycles were aspirated 36 h after administration of hCG. Granulosa cells were cultured for 150 min and corresponding OCCC were evaluated for maturity before fertilization with human sperm. Granulosa cell aromatase activity was measured using 1 beta-3H-testosterone as substrate by quantitating the amount of 3H2O produced. Progesterone production by the granulosa cells was measured as was follicular fluid levels of combined hCG and LH activity and FSH and PRL. Follicular fluid concentrations of combined hCG plus LH activity decreased somewhat while FSH levels increased as OCCC matured. PRL levels did not vary. Granulosa cell progesterone production did not change with maturity of OCCC . However, aromatase activity decreased as OCCC matured with levels from granulosa cells with immature OCCC vs. intermediate and mature OCCC of 260 +/- 148 vs. 129 +/- 53 (SE) pg E2/10(5) cells, respectively (P less than 0.07). Although granulosa cells responded variably to hMG stimulation from individual to individual, and the response was not predictable from peripheral serum estradiol levels, follicles isolated from the same patient had a definite diminution in aromatase activity with OCCC maturation. From these preliminary results, aromatase activity in immediately preovulatory granulosa cells declined as OCCC matured in hMG/hCG stimulated cycles.

Aromatase↗
PubMed1984

Human chorionic gonadotropin and prolactin modulation of early luteal function and luteinizing hormone receptor-binding activity in cultured human granulosa-luteal cells.

These studies were undertaken to explore the roles of both hCG and PRL in the modulation of early luteal function in the human. Human granulosa-luteal cells isolated during cycles stimulated by human menopausal gonadotropin hCG were obtained at the time of follicle aspiration and cultured to determine the effects of hCG and PRL on both progesterone and hCG receptor binding. Progesterone production by hCG-stimulated granulosa-luteal cells was increased 3.5-fold over unstimulated levels after 120 h, with maximal stimulation at hCG concentrations greater than 1 IU/ml. [125I]hCG binding to granulosa luteal cells was increased 3-fold in cells cultured with hCG (10 IU/ml) after both 48 h (P less than 0.03) and 96 h (P less than 0.02) in culture. hCG (1 IU/ml) stimulated a significant increase in progesterone production above basal levels after 72 h of culture, which continued to increase until 96 h of culture; 20 alpha-dihydroprogesterone (20 alpha-OH progesterone) production also was increased by hCG (1 IU/ml) at 72 h of culture, but unlike progesterone production, showed no further increase. In both the presence and absence of hCG, granulosa-luteal cells cultured with PRL (100 ng/ml) produced significantly more 20 alpha-OH progesterone (P less than 0.04 and P less than 0.02, respectively) after several days than cells cultured without PRL. In addition, progesterone production in the presence of hCG (10 IU/ml) decreased significantly (P less than 0.04) as 20 alpha-OH progesterone levels increased. Equivalent amounts of [125I]hCG were bound by human granulosa-luteal cells cultured with and without PRL (100 ng/ml). These results show that cultured human granulosa-luteal cells are responsive to hCG, with parallel increases in both progesterone production and [125I]hCG receptor binding. The presence of PRL (100 ng/ml) had no effect on [125I]hCG binding. In both the presence and absence of hCG, PRL resulted in an increase in 20 alpha-OH progesterone production and, in the presence of hCG (10 IU/ml), a decrease in progesterone production after several days in culture.

Cells, Cultured↗
PubMed1984

17 beta-estradiol and progesterone production by human granulosa-luteal cells isolated from human menopausal gonadotropin-stimulated cycles for in vitro fertilization.

The production of 17 beta-estradiol and progesterone (Prog) by human granulosa-luteal cells obtained from 24 aspirated follicles of 11 women undergoing laparoscopy in an in vitro fertilization program was studied. Follicular growth was stimulated with an individualized human menopausal gonadotropin regimen begun on either day 1 (group I; n = 5) or day 3 (group II; n = 6) of the menstrual cycle, and laparoscopy was performed 36 h after hCG administration. Granulosa-luteal cells were cultured for 2 h in culture medium alone or in the presence of either pregnenolone (10(-7) M) or testosterone (10(-7) M). Aromatase activity was present in the granulosa-luteal cells, as evidenced by a significant (P less than 0.001) increase in E2 production in the presence of testosterone. The addition of pregnenolone did not augment Prog production. Granulosa-luteal cells derived from Group II patients produced significantly (P less than 0.001) more Prog than those derived from group I patients. In addition, group II granulosa-luteal cells associated with mature oocyte-coronacumulus complexes produced significantly (P less than 0.001) more Prog than those in group I. Fertilization and pregnancy correlated with Prog production, in that granulosa-luteal cells associated with oocytes that were fertilized produced significantly (P less than 0.001) less Prog than those associated with nonfertilized oocytes. Granulosa-luteal cells from the 2 patients in this series who conceived demonstrated a further significant (P less than 0.02) reduction in Prog production. It appears that administration of human menopausal gonadotropin early (day 1) in the follicular phase results in incomplete maturation of the granulosa cells. Furthermore, the optimal oocyte, in terms of successful fertilization, may be one derived from a follicle that has undergone appropriate stimulation resulting in adequate maturation, but has not surpassed that point.

Adult↗
PubMed1984

Macroscopic and histologic tissue reaction to polydioxanone, a new, synthetic, monofilament microsuture.

A major contributing factor to failure in reconstructive tubal surgery is adhesion formation. It can be due to the presence of a foreign body primarily represented by suture material. A new, synthetic, absorbable suture material, Polydioxanone (PDS), was compared to polyglactin -910 (Vicryl). Microsurgical anastomosis of the bicornuate rat uterus served as a model. The right horn was anastomosed with 6-0 or 8-0 PDS and the left horn with Vicryl of the same diameter. At 3, 7, 14, 30 and 60 days after the procedure three to four animals were killed and the histologic reaction estimated and compared between the two horns. At 60 days the remaining animals were killed, and adhesion formation around the anastomosis site was recorded. PDS was found to be histologically more inert than Vicryl and was associated with a less intense acute and chronic inflammatory response than Vicryl. Similarly, macroscopic examination showed that the adhesion formation was quantitatively reduced in the PDS-treated horns, and most of those adhesions were avascular. The high inertness and absorbability suggest a practical application of PDS in infertility surgery.

Animals↗
PubMed1983

The in vivo and in vitro effects of clomiphene citrate on ovulation, fertilization, and development of cultured mouse oocytes.

Clinical data indicate a high rate of discrepancy between ovulation and pregnancy rates and a high abortion rate in anovulatory women treated with clomiphene citrate. An animal model was used to examine the in vivo and in vitro effects of the drug on fertilization and preimplantation development. This work indicates that mice treated with clomiphene in the early follicular phase of pregnant mare's serum-induced cycles show a dose-dependent decrease in ovulated oocytes. No effect was seen on the further development of these ova. When the drug was administered in the late follicular phase, a dose-dependent decrease was seen in the rate of successful copulation, ovulation, and embryo development. Concomitant 17 beta-estradiol treatment reversed the copulatory, ovulatory, and developmental effects of clomiphene. A short in vitro treatment of oocytes with clomiphene prior to in vitro fertilization resulted in an increased proportion of degenerated and unfertilized ova. Moreover, this treatment caused a dose-dependent decrease in blastocyst formation.

Animals↗
PubMed1983

Purine modulation of LH action in gonadal cells.

A rapid and marked amplification of LH and FSH-stimulated cyclic AMP accumulation and steroid secretion is produced by adenosine in luteal and granulosa cells, respectively, of both the rat and the human ovary. The rat Leydig cell response to LH, however, was unaffected by adenosine. In the luteal cell, adenine nucleotides and adenosine were equipotent with decreasing activity shown by inosine, adenine and hypoxanthine--guanosine, guanine, xanthine and pyrimidines were inactive. Both an extracellular and intracellular site appears to be involved in adenosine amplification of LH--the extracellular site accounted for about 20% of the response and may be a catalytic receptor site. The intracellular site was directly related to an increase in luteal cell ATP levels in which adenosine appears to serve as a selective prosubstrate for hormone activated adenylate cyclase. The luteal antigonadotropic action of PGF2 alpha was blocked by adenosine and these modulators were shown to be competitive antagonists of LH-stimulated cyclic AMP accumulation. Due to the ubiquitous nature of both adenosine and PGF2 alpha, (conditions have been described in other systems for their rapid release,) it is suggested that they may serve as important local humoral modulators of gonadotropin action for regulation and control of ovarian function.

Adenosine↗