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Biomedical subjects

G Lavy

Publications and source records attributed to G Lavy.

50 records · Page 3Linked to original sources
PubMed1987

The effect of polyploidy on embryo cleavage after in vitro fertilization in humans.

The effect of polyploidy on the early development of human embryos is unknown. This study compares the early development of 90 polyploid and 275 diploid human embryos conceived in vitro. Between May 1983 and January 1986, 3081 oocytes were recovered during 631 cycles of laparoscopy for in vitro fertilization (4.9 oocytes/cycle); 1924 oocytes (62.4%) fertilized. There were 90 oocytes with more than two pronuclei (4.7% of fertilized oocytes), identified in 72 cycles (11.4% of cycles). In these cycles, the proportion of diploid oocytes (n = 275) that cleaved (cleavage rate) (92.7%) was significantly greater than the proportion of polyploid oocytes (n = 90) that cleaved (65.5%) (P less than 0.001). The cleavage rate for all diploid oocytes (n = 1834) was 90.4%. There was no significant difference in the stage of development (number of blastomeres; mean +/- standard deviation [SD]) on the day of embryo transfer between diploid (4.3 +/- 2.1) and polyploid (4.1 +/- 2.1) embryos that cleaved, but a plot of the frequency distribution of cleavage stages revealed that significantly more polyploid than diploid embryos had an uneven number of blastomeres at that time (33% versus 8%, respectively; P less than 0.001). Polyploidy confers an immediate developmental disadvantage; one third of polyploid embryos fail to cleave, and those that do divide demonstrate more asynchronous divisions.

Blastomeres↗
PubMed1987

A paired analysis of in vitro fertilization and cleavage rates of first- versus last-recovered preovulatory human oocytes exposed to varying intervals of 100% CO2 pneumoperitoneum and general anesthesia.

This study compares the in vitro fertilization and cleavage rates of paired first- and last-recovered preovulatory human oocytes that were exposed to a 100% CO2 pneumoperitoneum and general anesthesia. In 305 consecutive cycles of laparoscopy, 1741 oocytes (5.7/cycle) were recovered. The exact time of aspiration (T) was recorded for each oocyte. The time interval (T1 to T2) between recovery of first and last oocytes ranged from 0 to 38 minutes and represented differences in the exposure time of first and last oocytes to the CO2 pneumoperitoneum and to general anesthesia. For all cycles (n = 305) without regard for T1 to T2, last-recovered oocytes fertilized less often than first-recovered eggs (P = 0.06; McNemar's test). When T1 to T2 was short (less than or equal to 5 minutes), first- and last-recovered oocytes fertilized at comparable rates (70.8% and 74.0%). When only cycles with T1 to T2 greater than 5 minutes were considered (n = 209), the difference in fertilization rates between first and last oocytes (68.5% versus 56.4%) was highly significant (P less than 0.01; McNemar's test). Pairing negated differences due to patient, cycle, or semen variables and first- and last-recovered oocytes had comparable maturity scores (4.0 +/- 0.5 versus 4.3 +/- 0.8). There were no significant differences in cleavage rates for first- and last-recovered oocytes that fertilized, regardless of the exposure interval (T1 to T2). We conclude that exposure to a 100% CO2 pneumoperitoneum and/or general anesthesia may adversely affect oocyte quality.

Anesthesia, General↗
PubMed1987

The hormonal basis of ectopic pregnancy.

The endocrine origin of EP revolves around certain endocrine events that modify reproductive tract function. The reproductive tract and the embryo are highly dependent on the proper function. Changes in this environment from either external or internal origin can lead to abnormalities in implantation including EP. Based on the examples presented above, it seems that both a high estrogenic or a high progestogenic environment can contribute to an increased risk of EP. This observation stresses the importance of the proper hormonal balance rather than an absolute value of a single hormone in the normal implantation process.

Chorionic Gonadotropin↗
PubMed1987

hCG free beta-subunit an early marker of outcome of in vitro fertilization clinical pregnancies.

In the in vitro fertilization (IVF) and embryo transfer (ET) program at Yale, 32% of pregnancies abort by 16 weeks. With the objective of predicting outcome, serum hCG titers were determined in serial samples from 48 women with clinical pregnancy (conception where fetal sac demonstrated by ultrasound). Although the mean hCG levels were lower at 8-14, 15-21, 22-28 and 29-35 days post-ET in the 18 women who eventually aborted, 0.18 (range 0.01-0.49), 1.5 (0.05-4.7), 6.4 (0.68-27), and 15 nmol/L (0.35-59), respectively, than in the 30 women whose pregnancy went to term, 0.48 (0.01-5.5), 2.2 (0.33-20), 10 (0.46-25), and 116 nmol/L (0.76-335) respectively, the ranges overlapped significantly, limiting the use of serum hCG in prediction. In earlier studies, the free beta-subunit of hCG was demonstrated in the serum of women with natural fertilization pregnancy, 2-6 weeks post ovulation. We used the RIA with 1E5 free beta-subunit monoclonal antibody to measure this component in the IVF serial blood samples. Of the 30 women who had pregnancies that went to term, samples from 28 were positive for this marker by 28 days post-ET (0.02-3.0 nmol/L). In 18 women who aborted, however, only 1 had a detectable serum hCG free beta-subunit level by 28 days post-ET. We conclude that a detectable serum hCG free beta-subunit level by 28 days post-ET may indicate normal term pregnancy outcome.

Abortion, Spontaneous↗
PubMed1987

A new device to facilitate intrauterine instillation of dextran 70 for hysteroscopy.

Dextran 70, a commonly used distension medium for diagnostic and operative hysteroscopy, is difficult to handle because of its high viscosity, which makes manual instillation cumbersome. We have developed an electric pump that facilitates the instillation of this distension medium at hysteroscopy. This new device is safe and easy to use, and improves the view of the uterine cavity during the procedure. Our initial experience using this pump in 43 hysteroscopic procedures is encouraging.

Dextrans↗
PubMed1987

Nutmeg intoxication in pregnancy. A case report.

A case of acute anticholinergic hyperstimulation in a pregnant woman was associated with excessive ingestion of nutmeg. The typical symptoms and signs, differential diagnosis and therapy are reviewed, with a special emphasis on the pregnant state.

Adult↗
PubMed1987

Endometrial ablation for intractable uterine bleeding: hysteroscopic resection.

Twenty-one patients with intractable uterine bleeding were treated by resectoscopic ablation of the endometrium. All the patients were worked up thoroughly to rule out hormonal or anatomic reasons for their bleeding. In addition, various hormonal regimens were tried to stop the bleeding. Our technique used the modified urologic resectoscope, which is inserted into the uterine cavity. The entire endometrial cavity was ablated using 30 W of coagulating current. Of the 21 patients treated, 14 had blood dyscrasias, four were poor anesthetic risks, and three refused hysterectomy. There were no complications from the procedure. Three patients died from their primary disease, and all the rest, except for one, remained amenorrheic. We conclude that the use of the resectoscope for endometrial ablation is a successful, efficient, safe, and readily available way to treat intractable uterine bleeding.

Cystoscopes↗
PubMed1987

Adhesion formation to the uterine horn of the rat in response to nylon and a new absorbable clip.

We have evaluated the tissue reactivity as manifested by adhesion formation to the uterine horn of the rat in response to a new absorbable surgical clip. A standard lesion on the uterine horn was created and repaired with either nylon sutures or an absorbable clip. Adhesion formation to the operative site was evaluated using a point based grading system, seven, 21 and 120 days postoperatively. A statistically significant increase in adhesion formation and their severity was seen on the uterine horns repaired with the surgical clips. The adhesions did not improve with time. In two instances, abscesses were formed around the clips. The use of the surgical clips in the peritoneal cavity needs to be investigated further. Their use in women in the reproductive age group who wish to preserve their reproductive potential is discouraged.

Animals↗
PubMed1986

Pregnancy following tubocornual anastomosis.

We have reviewed the pregnancy rate and outcome of 25 patients who underwent tubocornual anastomosis for correction of proximal tubal occlusion at Yale-New Haven Hospital between 1977 and 1981. Tubal occlusion was the result of previous tubal sterilization in 17 patients (11 laparoscopic electrocautery and 6 tubal ligation) and previous tubal infection in 8. Fourteen of the patients conceived (56%). Viable pregnancy was achieved in nine patients (36%) and tubal pregnancy in three (12%). No significant difference in pregnancy rates was found between patients with diseased cornua and those previously sterilized by either electrocautery or tubal ligation. Tubal length of greater than or equal to 4 cm following corrective surgery as compared with less than or equal to 4 cm did not influence pregnancy rates. The patients with the shorter oviducts had a higher rate of early pregnancy wastage. All three tubal pregnancies occurred in patients with reoccluded fallopian tubes as demonstrated by a hysterosalpingogram. We conclude that tubocornual anastomosis still remains the treatment of choice for patients with proximal tubal obstruction.

Adult↗
PubMedDate not supplied

The effect of insulin on oestradiol and progesterone release by normal and diabetic placentae in vitro.

In an attempt to define better the metabolic differences between normal, insulin-dependent and non-insulin-dependent diabetes, we have compared the effect of insulin on the secretion of oestradiol and progesterone in term placental explant culture. Placentae from non-diabetic and from diabetic, non-insulin-dependent diabetic patients demonstrated a similar response to incubation with insulin. This response consisted of a dose-dependent increase in both oestradiol and progesterone in the incubation media after 24 h. In contrast, the placentae of insulin-dependent diabetics showed a decrease in oestradiol and no change in progesterone secretion following exposure to insulin. These differences in response to insulin may underlie other metabolic differences between the placentae in the different groups.

Diabetes Mellitus↗
PubMedDate not supplied

The role of ACTH in placental steroidogenesis.

We have studied the possible function of the placental adrenocorticotrophic hormone-(ACTH-) like substance (PALS) in placental steroidogenesis by measuring oestradiol (E2) and progesterone (P4) in term human placental explants incubated with commercially available porcine ACTH I-39. There was a dose-dependent increase in the E2 and P4 released into the medium at 24 h as compared to controls. At 48 h, no significant effect was noted. Propranolol (10(-5) M) did not block the effect of ACTH on P4 release. The data suggest that ACTH may have a regulatory role on placental steroidogenesis. The possible mechanisms of action of PALS on the placenta and the adrenal are discussed, and the role of PALS in the maintenance of pregnancy and in maternal response to stress is suggested.

Adrenocorticotropic Hormone↗
PubMedDate not supplied

Progesterone production from granulosa cells of individual human follicles derived from diabetic and nondiabetic subjects.

Insulin and insulin-like growth factors have been implicated in the stimulation of ovarian steroidogenesis. To assess the effect of diabetes mellitus on this process, a comparison was made of progesterone production by cultured granulosa cells (50,000 cells/well) from 11 individual follicles of nondiabetic and 6 individual follicles of diabetic women. Diabetic metabolic control was fair [HbA1C 6.8, 8.7 (nl 5.0-7.5)]. Cells were collected by laparoscopic follicular aspiration after ovulation induction and isolated by Percoll gradient centrifugation. Progesterone production was measured after culture with hCG (10 IU/mL) or insulin (100 microU/mL). In both nondiabetic and diabetic groups on day 4, hCG significantly stimulated progesterone production (1,686 +/- 1,268 ng/mL to 4,123 +/- 2,825 ng/mL and 1,059 +/- 249 ng/mL to 1,506 +/- 245 ng/mL, respectively). In nondiabetic follicles, insulin also stimulated progesterone production on days 4 (2366 +/- 1032 ng/mL to 3699 +/- 1582 ng/mL; P less than .05) and 7 (987 +/- 475 ng/mL to 1858 +/- 929 ng/mL; P less than .05); this response was not noted in diabetic granulosa cells. We suggest that insulin-stimulated progesterone production by granulosa cells isolated in the presence of fair diabetic metabolic control is impaired.

Cells, Cultured↗
PubMedDate not supplied

Reversal by human chorionic gonadotropin of the inhibitory effect of clomiphene on progesterone production by granulosa-luteal cells in culture.

The possibility of a direct ovarian effect of clomiphene citrate was assessed in vitro by measuring progesterone release from cultured human granulosa-luteal cells in both the presence and absence of hCG. Granulosa-luteal cells obtained by laparoscopic follicle aspiration following ovarian stimulation with hMG and hCG in women undergoing in vitro fertilization/embryo transfer were incubated for 72 hours in medium containing increasing concentrations of clomiphene (10(-9) - 10(-5) M) both without and with hCG (1 IU/mL). Clomiphene stimulated progesterone production in both the presence and absence of additional hCG at concentrations less than or equal to 10(7) M. In both the presence and absence of hCG a dose-dependent inhibition of progesterone production was observed with higher concentrations of clomiphene (greater than 10(6) M). hCG (1 IU/mL) significantly increased progesterone production in control cells and at all concentrations of clomiphene (10(-9)-10(-5) M) tested. Low clomiphene (10(-9)-10(-7) M) and hCG concentrations appeared to have a synergistic effect on progesterone production. Thus it appears that clomiphene has a direct ovarian effect on progesterone production, which is stimulatory at low concentrations and inhibitory at higher concentrations.

Adult↗