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Biomedical subjects

L Wildt

Publications and source records attributed to L Wildt.

At least 91 records · Page 5Linked to original sources
PubMed1989

Cryopreservation of human and rabbit oocytes and one-cell embryos: a comparison of DMSO and propanediol.

The aim of this study was to improve the cryopreservation of human oocytes and pronuclear embryos. One-step and multiple-step addition of dimethyl sulphoxide (DMSO) and 1,2-propanediol (PROH) and three different freezing protocols with intermediate temperatures of -35, -70 and -110 degrees C were investigated. This work was performed using rabbit oocytes as well as human oocytes and one-cell embryos from the routine IVF programme. Also, human polyploid pronucleate oocytes were used in controlled prospective studies of morphological intactness and development in vitro. Rabbit oocytes survived best (113/126) when PROH was added in one step and controlled freezing stopped at -110 degrees C. But the development was better (141/187) if DMSO was added in multiple steps and the oocytes were cooled to -70 degrees C before being plunged into liquid nitrogen. The mode of addition of the cryoprotectant influenced development only if slow freezing was stopped at -35 degrees C (51 versus 34%). Using PROH, the development after thawing was also better if cooling was stopped at -35 degrees C (51 versus 37%) and DMSO was superior to PROH when the oocytes were cooled slowly to -110 degrees C (66 versus 37%). In the human, significantly more pronucleated than unfertilized oocytes developed after freezing (92 versus 50%). The best results were achieved with pronuclear embryos using 1.5 M PROH and cooling to -110 degrees C, when 91.7% of the surviving oocytes developed further. This is a marked improvement of the development rate and comparable to embryo freezing.

Animals↗
PubMed1989

Comparative results on survival of human and animal eggs using different cryoprotectants and freeze-thawing regimens. I. Mouse and hamster.

The achievement of successful pregnancies and births after in-vitro fertilization and embryo transfer of frozen-thawed human oocytes has stimulated further work on improving the established methodology. The present investigation was conducted on 1837 mouse oocytes, 1785 mouse pronuclear stage embryos, 1400 hamster oocytes and 1024 hamster pronuclear-stage embryos. In an effort to study the advantages and disadvantages of a newly introduced, 1,2-propanediol (1,2-PROH)-based system over the conventionally used dimethylsulphoxide (DMSO)-based methodology, a direct, prospective comparison between the two cryoprotectants was undertaken in a randomized trial. The combination of 1,2-PROH and DMSO potentiates their cryoprotective effect on mouse and hamster eggs. 1,2-PROH seems to improve cryopreservation in the animal system, though not significantly. Four different protocols were used to evaluate the effects of two changing experimental parameters. These were, firstly, the intermediary temperature attained before placing the cells into liquid nitrogen and, secondly, the modification of the method of adding and removing the cryoprotectant. The morphological survival rate, fertilization rate and developmental rate were significantly better in the low intermediary temperature compared with the high intermediary temperature system of cryopreservation. In addition, the rate of zona pellucida breakdown diminishes considerably in the former compared with the latter system. The 'rapid' sucrose method of cryoprotectant equilibrium and removal showed, in most groups, results which were lower than, or equal to, the traditionally used 'multiple-step', 'slow' method.

Animals↗
PubMed1989

Comparative results on survival of human and animal eggs using different cryoprotectants and freeze-thawing regimens. II. Human.

A total of 269 human pronuclear embryos and 84 oocytes were subjected to four different protocols of cryoprotectant equilibration, washing out and freeze-thawing. The morphological survival, rate of development, fertilization in vitro and overall survival rate were estimated in the groups of fresh, aged oocytes, diploid and multipronuclear embryos used. With some restrictions, the conclusion can be drawn that slow, low intermediary temperature 1,2-propanediol (1,2-PROH) and 1,2-PROH/dimethyl sulphoxide (DMSO) systems are superior to the rapid, high intermediary temperature 1,2-PROH and the traditionally used DMSO systems. The best success rates were reached with the combination of cryoprotectants in the low intermediary temperature group. Thirty-three patients had 37 transfers of cryopreserved pronuclear embryos (n = 103), resulting in eight pregnancies (24.2% per transfer) thus doubling the pregnancy rate in the stimulation cycles for the same period (21% per transfer). Thawing at a rate of 50 degrees C/min is not incompatible with the survival of slowly frozen human oocytes and pronuclear embryos cooled to an intermediary temperature of -70 degrees C using the DMSO system.

Cell Survival↗
PubMed1988

Serum CA-125 as a guideline for the timing of a second-look operation and second-line treatment in ovarian cancer.

In the assessment of response to treatment of ovarian cancer patients, clinical examination is unreliable in detecting small tumor masses. The second-look laparotomy is therefore an accepted procedure. The optimal timing of second-look laparotomy, however, is uncertain. We therefore examined the usefulness of serial serum CA-125 estimations in the timing of second-look laparotomies in 33 patients suffering from ovarian cancer. Increasing CA-125 concentrations were always followed by relapses or progressive disease, whereas decreasing serum concentrations indicated response to treatment. In future we propose to perform second-look laparotomies when CA-125 levels have declined to a steady plateau and to start a secondary treatment when CA-125 levels start to rise again.

Antigens, Neoplasm↗
PubMed1988

CA-125 serum concentrations during the menstrual cycle.

CA-125 is an antigenic determinant expressed on ovarian cancer cells and serves as serum marker in patients with ovarian cancer. It has also been detected, however, in serum of healthy women and in patients with benign gynecologic diseases. Previous studies in patients with ovarian hyperstimulation syndrome suggested that the production of CA-125 is correlated with proliferative ovarian activity. In this study, we describe the pattern of CA-125 secretion in 13 healthy women during menstrual cycle and during hormonal contraceptive treatment. That pattern is characterized by an increase of CA-125 serum concentrations parallel to the growth of the dominant follicle. It was not observed during hormonal contraceptive treatment. We conclude that CA-125 serum levels during menstrual cycle seem to be dependent upon the cyclic changes in the female genital tract.

Adult↗
PubMed1988

Combined GnRH-agonist/gonadotrophin stimulation for in-vitro fertilization.

The occurrence of a premature luteinizing hormone (LH) surge during gonadotrophin stimulation for in-vitro fertilization leads to cancellation of the cycle. Moreover, insufficient follicular maturation is often caused by elevated basal gonadotrophin levels. Therefore, the gonadotrophin-releasing hormone (GnRH) agonist, D-Trp-6-LHRH, was applied to patients exhibiting premature LH surges, hyperandrogenaemia or incipient premature menopause. A total of 119 cycles were treated using a long-acting versus a short-acting GnRH agonistic analogue. In protocol 1, patients received daily s.c. injections of 100-500 micrograms of a short-acting compound. In protocol 2, a long-acting bolus of 3.2 mg was given i.m. Concomitant human gonadotrophin stimulation was started in protocol 1 after clinical and biochemical evidence of pituitary suppression and in protocol 2 after a fixed suppression interval of 14 days. In protocol 1, higher oestrogen levels were reached with more oocytes harvested. The pregnancy rate per transfer was increased from 3.5 to 18%, with most pregnancies occurring with protocol 1. The cancellation rate of 13.4% was mainly due to insufficient follicular development in patients in whom premature menopause was suspected. Hyperandrogenaemic patients with an elevated LH/FSH ratio exhibited the best follicular recruitment with the highest pregnancy rate of 25% per transfer. Thus, combined GnRH-agonist/gonadotrophin stimulation offers a causal treatment for patients susceptible to premature LH surges and for hyperandrogenaemic patients.

Adult↗
PubMed1987

Elevated levels of CA-125 in serum of patients suffering from ovarian hyperstimulation syndrome.

Elevated levels of CA-125, an antigen expressed by malignant ovarian tissue, have been found in women who developed OHSS in response to treatment with exogenous gonadotropins for IVF. In contrast, CA-125 concentrations in women who were treated with an identical regimen but who did not show signs of OHSS remained in the normal range. We conclude that the expression of CA-125 is not restricted to neoplastic ovarian tissue but can also occur as a consequence of supraphysiologic stimulation of the ovary with exogenous gonadotropins.

Antigens, Neoplasm↗
PubMed1987

[Ovarian stimulation with pure FSH in an in vitro fertilization program].

The therapeutic efficacy of stimulating ovarian follicular development by pure urinary FSH in an IVF programme was determined and compared with results of other therapeutic regimes. 43 patients selected for extracorporeal fertilization were treated with pure FSH after stimulation with clomiphene or HMG had proven not be successful. Only in 5 patients (12%) treatment had to be discontinued before follicular puncture. In 32 women an embryo transfer was performed, and 7 patients conceived. This result demonstrates that, applying pure FSH stimulation, favourable conditions can be created for an in-vitro fertilization in patients with impaired follicular maturation following conventional stimulation with clomiphene or HMG. On the strength of the values determined for progesterone and estradiol during the luteal phase one has to conclude that a normal corpus luteum function was achieved in all our patients following FSH-stimulation.

Embryo Transfer↗
PubMed1987

Pulsatility of serum LH in pathological conditions.

LH pulsatility changes throughout the normal menstrual cycle. The number of LH pulses increases during the first days after menstruation, remains unchanged thereafter until after ovulation and declines progressively during the luteal phase. LH pulse amplitude is highest during midcycle. In hypothalamic amenorrhea, gonadotropin levels are reduced. This appears to be a consequence of a reduction of hypothalamic Gn-RH secretion which is reflected by a diminished frequency and amplitude of LH pulses during the 24-hour span. Administration of an opiate antagonist, naloxone, increases LH pulse frequency in those patients, and in patients with secondary hypothalamic amenorrhea the daily oral administration of naltrexone, another specific opiate antagonist, induces ovulatory cycles. Patients suffering from hyperandrogenemia may present with eumenorrhea, oligomenorrhea or amenorrhea. There is an increase in mean LH levels and of the LH/FSH ratio with increasing severity of the ovarian disturbance. The increase in mean LH levels is a consequence of an increase in LH pulse amplitude while LH pulse frequency is not changed compared to the early follicular phase of the menstrual cycle.

Amenorrhea↗
PubMed1987

[24-hour CA 15/3 serum concentrations in patients with primary and metastasizing breast cancer].

Serum determinations of tumor-associated antigens in breast cancer patients are utilized for detection of metastases as well as prediction of treatment response. That is critically dependent on the validity of single daily marker determination. In our study in patients suffering from primary or metastatic breast cancer we could demonstrate fluctuations of antigens detected with the two monoclonal antibodies 115D8 and DF3 (CA-15/3) during a 24 h observation period. Beside methodical inaccuracies those fluctuating serum concentrations might be related to biological phenomena. However, on basis of our data no intra- or interindividual rhythms could be exhibited.

Antigens, Neoplasm↗
PubMed1987

Induction of ovulation by the chronic administration of naltrexone in hypothalamic amenorrhea.

Ovulatory menstrual cycles were induced by the administration of the specific opiate antagonist naltrexone at a dose of 50 mg/day for 28 days in 3 women suffering from secondary hypothalamic amenorrhea. The occurrence of ovulation was based on demonstration of follicular growth and corpus luteum formation by ultrasonography and a LH midcycle surge and rise of progesterone. After discontinuation of treatment, the women became amenorrheic again and serum gonadotropins as well as estradiol declined to the low levels found before naltrexone administration. Naltrexone or other specific opiate antagonists may be useful agents for the induction of ovulation in patients with hypothalamic amenorrhea.

Adult↗
PubMed1986

Ovarian hyperstimulation for in-vitro fertilization controlled by GnRH agonist administered in combination with human menopausal gonadotrophins.

Surges of luteinizing hormone (LH) in serum that result in luteinization, but occur prematurely with respect to the diameter of the leading follicle, frustrate attempts to induce multiple follicular maturation for in-vitro fertilization (IVF) in a number of women. We examined the possibility of blocking premature LH surges by the administration of D-TRP6-LH-RH, a potent agonistic analogue of gonadotrophin-releasing hormone (GnRH). Six patients who had repeatedly shown premature LH surges were treated for 10 days, beginning between days 1 and 3 of the cycle with daily s.c. injections of 500 micrograms D-Trp6-LH-RH followed by a daily injection of 100 micrograms of the analogue until the day of administration of human chorionic gonadotrophin (HCG). When pituitary and ovarian suppression had occurred, ovarian stimulation with human menopausal gonadotrophin was started and adjusted in dose according to the ovarian response. HCG was injected when the dominant follicle had reached a diameter of at least 18 mm and oestradiol levels were above 300 pg for each follicle greater than 15 mm. Oocyte collection was performed 36 h later via laparoscopy, followed by IVF and embryo transfer. The six patients studied to date responded to therapy and treatment could be completed up to embryo transfer. Two patients became pregnant; one of the pregnancies, however, resulted in abortion. Combined treatment with GnRH analogue for suppression of pituitary gonadotrophin secretion followed by the administration of gonadotrophins thus seems to be a promising method for ovarian stimulation in patients who frequently exhibit premature LH discharges and therefore fail to complete treatment.

Adult↗
PubMed1985

Induction of puberty in a patient with hypogonadotropic hypogonadism: effect of sequentially applied hCG and pulsatile GnRH administration.

Pulsatile substitution with GnRH appears to be the therapy of choice in patients with Kallmann's syndrome, a well defined type of hypogonadotropic hypogonadism. We tried to simplify the treatment and to limit the subcutaneous GnRH therapy to the period absolutely necessary to induce spermatogenesis. Therefore we applied in sequence first hCG to stimulate testicular growth and second pulsatile GnRH application to induce spermatogenesis. We herein report that with this mode of therapy testicular growth from infantile to adult size and normal spermatogenesis could be achieved. We conclude that pulsatile GnRH application is a new effective therapy of hypogonadotropic hypogonadism which can be simplified considerably by pretreatment with hCG.

Adult↗
PubMed1984

[Hypothalamic control of ovarian function and its disorders].

The biological clock of the female cycle is the ovary: the arise of estrogen primes the hypophysis for releasing hormones (GNRH) and cause the LH surge. Nevertheless, frequency and amplitude of GNRH are important points for the release of gonadotropic hormones and are involved in several pathophysiological situations: in corpus luteum insufficiency, in anovulation and in amenorrhoea.

Adolescent↗