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Biomedical subjects

B Lassalle

Publications and source records attributed to B Lassalle.

At least 37 records · Page 2Linked to original sources
PubMed1987

Factors influencing the success rate of human embryo freezing in an in vitro fertilization and embryo transfer program.

Certain factors influencing the success of embryo cryopreservation were analyzed from 124 cycles of in vitro fertilization and embryo transfer (IVF-ET) program in which 193 1- or 2-day embryos were frozen and had already been thawed. There were 100 transfers of one or two surviving embryos from which 26 pregnancies were initiated. Several factors significantly influenced embryo survival after thawing. They were: the developmental stage of frozen embryos; the appearance of the embryo at the time of freezing; and the mode of ovarian stimulation in the IVF cycle. The pregnancy rate after frozen-thawed embryo transfer was higher with 4-cell frozen embryos than with embryos at all other stages combined. There were also tendencies for the pregnancy rate to be higher if a spontaneous luteinizing hormone surge occurred in the transfer cycle or if the duration of embryo storage did not exceed 1 to 2 months. The results obtained support a new policy in IVF-ET programs: it should be advantageous for the sterile couple if the immediate fresh embryo transfer is only performed with the categories of embryos that demonstrate a poor aptitude for survival following cryopreservation procedures.

Embryo Transfer↗
PubMed1986

Programmed oocyte retrieval during routine laparoscopy and embryo cryopreservation for later transfer.

Fixed-schedule ovulation induction and cryopreservation of the obtained embryos was performed in women undergoing a preliminary laparoscopy for infertility investigation before possible inclusion in an in vitro fertilization program. The cycle before follicular stimulation was modified by a progestogen or an estrogen-progestogen contraceptive pill. Ovarian inaccessibility precluded follicular aspiration in four of 34 patients but at least one oocyte was obtained in 29 of the remaining 30. Although fewer oocytes were obtained in these patients than in a control group undergoing in vitro fertilization treatment, one or more embryos were obtained in 22 patients in the study group. All embryos were frozen and to date 25 embryos from 17 patients have been thawed. Embryos have been placed in 16 of the 17 patients and six pregnancies have been initiated. Three are currently ongoing, one ectopic pregnancy was recorded, and two pregnancies were classified as "chemical." Programmed oocyte retrieval and embryo cryopreservation resulted in an extra chance of pregnancy in patients undergoing a laparoscopy for infertility investigation.

Adult↗
PubMed1986

High pregnancy rate after early human embryo freezing.

Human embryos produced by in vitro fertilization (IVF) were frozen with 1,2-propanediol as a cryoprotectant. Embryo survival after thawing was related to the presence of a nucleus in frozen cells and decreased with the increasing number of cells in the frozen embryo. None of five embryos frozen 3 or 4 days after IVF survived when thawed. Of 48 early embryos (35 patients) frozen 1 or 2 days after IVF, 42 (87.5%) were transferred in 32 patients. Ten pregnancies were initiated after frozen embryo transfer (ET). If we exclude the three infertile patients who had sexual intercourse in the fertile period, the pregnancy rate for each patient who had 1- or 2-day frozen embryo(s) was 22% (7 of 32). One of the pregnancies was obtained after ET of a 1-cell pronucleated frozen and thawed embryo. The rate of ongoing pregnancies after triple fresh ET was 23%. In patients having four embryos obtained in a single IVF cycle, the expected overall liveborn rate in an IVF-ET program including embryo cryopreservation could theoretically equal that of natural human fertility.

Cell Survival↗
PubMed1985

Human embryo features that influence the success of cryopreservation with the use of 1,2 propanediol.

Eighty-five human embryos fertilized in vitro were frozen and thawed with 1,2 propanediol as a cryoprotective agent. The effects of viability of in vitro culture duration, stage, and morphologic appearance of embryos were examined after thawing. Survival was higher for 2-day-old embryos than for 3-day-old embryos (56% versus 18%) and for 2-, 4-, and 8-cell embryos than for intermediate-cleavage-stage embryos (67% versus 22%). Among 19 regular-cell-size embryos at the 2-, 4-, and 8-cell stage, 15 (79%) kept 50% or more of their initial number of blastomeres after thawing and 9 were intact. The average viability of all 2-day-old frozen-thawed embryos can be estimated at 19%.

Blastocyst↗
PubMed1985

Control of the blastemal cell cycle by the peripheral nervous system during newt limb regeneration; continuous labeling analysis.

Forty-eight and 96 hr 3H-thymidine continuous labeling was analyzed on denervated mid-bud limb blastemas of Pleurodeles waltlii M. In innervated blastemas, 92 to 95% of mesenchymal cells are cycling; denervation provokes an early exiting from the cycle in G0-1(+ 15% of non-cycling cells for a 6-day denervation, + 20% for an 8 day denervation) and an elongation of the G1 phase. For epidermis only 25% (48 hr labeling) to 53% (96 hr labeling) of cells are cycling in innervated blastemas; denervation strongly decreases this percentage (+ 40% of non-cycling cells for a 6-day denervation, + 60% for an 8-day denervation). As for mesenchyme, denervation also lengthens the G1 phase of epidermal cells. So our results contradict the conclusion of other authors claiming a G2 blockage. They account for the fall in proliferation indices and the arrest of regeneration after denervation. Finally, they show that the cell cycle of regeneration cells is controlled by the neurotrophic factor.

Animals↗
PubMed1984

In vitro fertilization and embryo transfer program in Clamart, France.

Our in vitro fertilization and embryo transfer program really began in September 1980. Yet attempts to collect oocytes had been performed since 1978, and the first in vitro fertilizations were obtained in May 1979. The first pregnancy was obtained in April 1981, but it ended on the 12th week by a spontaneous abortion of a 45,X fetus. We have distinguished two periods in our program. The initial phase was from September 1980 until November 1982: ovulation monitoring of 365 cycles, spontaneous or stimulated, 276 laparoscopies, and 121 embryos transfers were performed, and 12 early pregnancies obtained (4.3% per laparoscopy and 9.9% per embryo transfer). Seven normal healthy infants were born (five boys and two girls); four cases were limited to biochemical pregnancies and one spontaneous abortion (yet described) was observed. The second and actual phase, December 1982-June 1983, is described more precisely: ovulation monitoring of 329 cycles, after stimulation protocols with clomiphene citrate and human menopausal gonadotropin, 230 laparoscopies, and 162 embryos transfers have been performed and have led to 34 pregnancies (14.8% per laparoscopy and 20.9% per embryo transfer). Eighteen of these 34 pregnancies are actually in progress (more than 12 weeks), 9 were limited to an increase in plasma human chorionic gonadotropin, and 7 cases ended in spontaneous abortions between 6 and 12 weeks.

Adult↗
PubMed1983

Influence of putative neurotransmitters on brain electrical activity in Lithobius forficatus L. (Myriapoda Chilopoda).

Various putative neurotransmitters and related drugs were tested on the electrical activity of the brain of L. forficatus, at various times during the year. Indirect evidence exists for a depressant action from GABA. Ach, 5HT, NA and DA have stimulatory effects. However, DA effects were found to vary with the season, suggesting a role in the control of an annual cycle.

Acetylcholine↗
PubMed1983

A study of factors affecting the success of human fertilization in vitro. II. Influence of semen quality and oocyte maturity on fertilization and cleavage.

The incidence of in vitro fertilization was analyzed with respect to the degree of cumulus dissociation (expansion) at the time of oocyte recovery and also the semen quality. Of the oocytes surrounded by perfectly ("++") or moderately ("+") dissociated cumuli, 78.6% and 30.8%, respectively (P less than 0.001), were fertilized when the husband's semen analysis was in the normal range. The proportion of fertilized oocytes was not decreased in cases of polyzoospermia (greater than 130 X 10(6) spermatozoa/ml), but was decreased (P less than 0.05) when the semen analysis revealed other anomalies: oligozoospermia (less than 15 X 10(6) spermatozoa/ml), asthenozoospermia (less than 50% motile cells) or teratozoospermia (greater than 50% abnormal spermatozoa). The proportion of fertilized eggs cleaving in vitro was unaffected by semen quality but was lower when "+" cumulus oocytes were collected than when "++" cumulus oocytes were obtained (58.3% vs. 87.0%, P less than 0.02). In vitro incubation of the oocyte prior to insemination increased the incidence of fertilization by about 28% for both "+" (22.2 to 50.0%) and "++" (65.7 to 93.9%) cumulus oocytes. Finally, 67.6% of "++" cumulus oocytes developed into embryos when the insemination with spermatozoa from normal semen samples was delayed by several hours, compared with only 29.0% when the conditions were suboptimal ("+" cumulus oocyte, abnormal semen analysis or no delay prior to insemination). Eight pregnancies began following the replacement of 38 embryos in 34 patients. Six spontaneous abortions occurred, and chromosomal abnormalities were proven in the two cases analyzed. Two pregnancies continued for more than 3 months, resulting in term deliveries of two normal babies.

Cell Division↗
PubMed1981

[Spontaneous abortion after intra-uterine transfer of an ovum fecundated in vitro (author's transl)].

Spontaneous expulsion of a human ovum fecundated in vitro and transferred into the uterus occurred after 10 1/2 weeks of amenorrhoea. The oocyte had been collected after stimulation by human menopausal and chorionic gonadotrophins (hMG and hCG). The techniques of pre-ovulatory oocyte collection, fecundation, in vitro culture and of reimplantation of the embryo are briefly described.

Abortion, Spontaneous↗
PubMed1981

Electrophysiological evidence for direct ecdysteroid action on the brain in Lithobius forficatus L. (Myriapoda: Chilopoda).

Electrical activity of the brain of Lithobius forficatus has been recorded. The addition of ecdysteroids (moulting hormone) in the haemolymph increased the frequency and amplitude of electrical response. Such a stimulation might be specific to these products since cholesterol and juvenile hormone had no action. The destruction or removal of various parts of the cephalic endocrine system demonstrated that the pars intercerebralis (p.i.) (postero-median area of the protocerebron) was responsible for increasing electrical activity after ecdysone supply.

Animals↗
PubMed1979

Surface potentials and the control of amphibian limb regeneration.

The relationship between surface potentials and amphibian limb regeneration is examined. The wound surface becomes increasingly positive for several days after amputation but then decreases again, often becoming negative for a variable period during blastemal growth. The same changes of surface potentials are observed during wound healing alone, in the absence of amputation and following amputation of irradiated or denervated limbs. Similar changes occur in non-regnerating frog arms. These observations and other cited reasons lead to the conclusion that surface potentials do not control regeneration.

Animals↗
PubMed1977

[In vitro evaluation of cutaneous potentials in the triton, Pleurodeles waltlii Michah., by measuring transepithelial potentials].

Surface potentials previously measured in vivo have been approximately evaluated in vitro by means of an experimental device allowing a simultaneous record of transepithelial potential differences in 2 areas of the same skin piece cut out along the proximo-distal direction of the anterior limb of Pleurodeles waltlii. These potentials are thus explained by unequal transepithelial potential differences in the proximal and distal areas of the same skin sample.

Animals↗