O-285 Artificial intelligence algorithms reach expert-level accuracy in automated grading of blastocyst morphology assessment based on static embryo images and Gardner criteria

Study question

Can artificial intelligence (AI) algorithms reach expert-level accuracy in blastocyst morphology assessment according to Gardner criteria?

Summary answer

The prediction accuracy of the best performing AI algorithm (Deit), outperformed human-level mean accuracies compared to an embryologist majority vote for all Gardner morphological criteria.

What is known already

Routinely, morphological grading of blastocysts is performed visually according to Gardner criteria, which suggest expansion (EXP), quality of inner cell mass (ICM), and trophectoderm (TE) as key parameters to predict treatment outcome. Consequently, blastocyst scoring is prone to inter-and intra-observer variability, which may lead to inconsistencies in selecting blastocysts for transfer. AI-based algorithms may help to improve treatment outcome predictability, as it has been suggested recently. In those studies, parameters such as blastocyst quality or stage were annotated by experts from static or time-lapse-derived blastocyst images, to train AI algorithms, e.g. XCeption or YOLO, and compare them to human annotators.

Study design, size, duration

This retrospective study involves 2,270 images from 837 patients collected over a period of four years in a university IVF clinic.

Participants/materials, setting, methods

All images were annotated by one senior embryologist and divided into a training and a balanced test set. Subsequently, eight embryologists labeled 300 test set images such that every single image was seen by at least four embryologists. Annotators diverging from the ensemble vote for more than one standard deviation were excluded (n = 2) to set the ground truth labels. Finally, three AI architectures (XCeption, Swin, Deit) were trained and evaluated on that particular ground truth.

Main results and the role of chance

Out of nine annotators, labelling accuracy of two embryologists diverged from the consensus vote for more than one standard deviation for at least one of the three Gardner criteria. The consensus vote was built from the remaining seven annotators (mean accuracy EXP 0.81, ICM 0.70, TE 0.67). The Swin architecture outperformed the mean expert accuracy for all three criteria (EXP 0.82, ICM 0.76, TE 0.68), while the Deit and the XCeption architecture outperformed the mean expert accuracy in ICM accuracy (Deit 0.72, XCeption 0.73), and performed equal or worse in EXP and TE accuracy (Deit EXP 0.77, ICM 0.73; XCeption EXP 0.77, TE 0.66). When compared to a recent study conducted on time-lapse imaging data using AI algorithms, all our models outperform the ICM accuracy and achieve comparable TE accuracy. To minimize the role of chance in calculating the models' prediction accuracies, the SWA-Gaussian (SWAG) algorithm was used. SWAG is a method to reflect and calibrate uncertainty representation in Bayesian deep learning. It is based on modelling a Gaussian distribution for each networks' weight and applying it as a posterior over all neural network weights to perform Bayesian model averaging.

Limitations, reasons for caution

To reflect a real IVF lab scenario, embryologists of different origins and levels of experience were involved and no scoring training was offered to the participants. These facts could have potentially negatively affected the degree of consensus, although we excluded two annotators diverging from the mean labeling accuracy.

Wider implications of the findings

In the past, AI algorithms proved to reliably differentiate between good and bad prognosis blastocysts but not necessarily between blastocysts of similar quality. Further AI-supported differentiation on the basis of expansion and cell lineages will facilitate the ranking of blastocysts and would bring automated scoring closer to clinical application.

Trial registration number

Not applicable.

P-392 Peripheral blood naïve Treg (nTreg) cell subsets and implantation success in patients undergoing in vitro fertilization (IVF) treatment

Study question

Which populations of circulating Treg cells, based on immunophenotyping with thirteen color flow cytometry and analysis with clustering algorithms play a role in implantation?

Summary answer

The phenotype of subpopulation within Treg cells that was most significantly increased in women who became pregnant was nTreg-like phenotype, which lacked CXCR5 expression.

What is known already

There are indications that Treg lymphocytes mediated immuno-regulatory mechanisms contribute to the occurrence of idiopathic infertility. Findings of studies indicate that higher nTreg cell subsets were associated with successful IVF treatment. These findings suggest that changes in the composition of the nTreg subset may allow increased tolerance induction during implantation. More detailed characterization of the Tregs in blood samples from women undergoing IVF/ICSI treatment has not been performed and the degree of heterogeneity of among these cells has not been studied to date. Using 13-color flow cytometry Tregs cells can be divided into multiple complex subsets based on different markers.

Study design, size, duration

This prospective observational study included 36 patients undergoing IVF/ICSI treatment. Blood samples for 13-color flow cytometry, UMAP and FlowSOM cell clustering analyses were obtained from 19 patients undergoing controlled ovarian hyperstimulation and 17 patients undergoing vitrified-warmed blastocysts transfer (FET) in the natural cycle on the day of optimal blastocysts transfer, for data analysis GraphPad Prism was used. The study was performed between March 2020 and October 2021.

Participants/materials, setting, methods

In this study peripheral blood Treg cells composition was determined. We analyzed the phenotype of populations over or under-represented in samples from women who became pregnant compared to the women who did not within Treg cells. Treg cells were analyzed by both standard gating flow cytometry analysis and clustered by algorithms according to their level of expression of cell surface markers: CD25 (IL-2Rα), CD127 (IL-7Rα), CCR7, CXCR5, CD28, CD38, CD161, CD31, CD45RA, HLA-DR and CD15s.

Main results and the role of chance

Thirteen color flow cytometry and dimensionality reduction analyses were carried out, using the UMAP and FlowSOM cell clustering algorithms. Combining these tools, we were able to analyze the phenotype of populations in samples from women who became pregnant ( n = 23) compared to the women who did not (n = 13) within Treg cells. FlowSOM identified 15 phenotypically distinct populations within Treg cells. The most prevalent population that was increased in women who became pregnant was nTreg-like phenotype, which lacked CXCR5 expression. This related to our results by standard gating, where we observed that the percentage of CXCR5-nTreg cells and CD31+RTEnTreg cells within CD25+CD127low Treg cells was significantly higher in pregnant women (p = 0.003; p = 0.0162, respectively). Pregnant females had significantly higher percentage of CD45RA+nTreg cells within CD25hiCD127low Treg cells (p = 0.0162) which was in good correlation with the percentage of CD45RA+FOXP3low nTreg cells within CD25+FOXP3+ Treg cells (p < 0.0001). Furthermore, the percentage of CD45RA+FOXP3+low nTreg cells within CD25+FOXP3+ Treg cells was significantly higher in pregnant women (p = 0.045). Meanwhile, the percentage of CD45RA-FOXP3hi effector (eTreg) Treg cells within CD25+FOXP3 Treg cells was lower in pregnant women (p = 0.0238). Finally, women who achieve a pregnancy had significantly lower percentage of CD45RA-FOXP3hiCD15s+eTreg cells within CD25+FOXP3+ Treg cells (p = 0.0233).

Limitations, reasons for caution

This study has some limitations. The sample size is too small. Standard gating in flow cytometry has the limitation of analysing only few markers at a time in a flow plot, the levels of expression of the markers are not considered, as an alternative, dimensionality reduction analyses were carried out.

Wider implications of the findings

Our findings imply that the composition of distinct populations within nTreg cells can influence the women’s chance of becoming pregnant, especially nTreg cells, lacking CXCR5 expression, which distingushes T-follicular regulatory cells. Findings help us to understand the role of nTreg subpopulations in process of implantation in women undergoing IVF/ICSI treatment.

Trial registration number

not applicable

P–782 A natural language processing approach of global survey results on what the embryologist thinks and faces

Study question

What are the major problems faced by embryologists at 1) Clinic level, 2) Professional level, 3) Personal level, and 4) What are their career goals?

Summary answer

Embryologists, essential professionals of Fertility Centres, are less satisfied in many quantifiable aspects, but they love their profession and have many aspirational goals.

What is known already

IVF success depends in part on embryologists’ skills. The need to recognize clinical embryology as a specialty and clinical embryologists’ educational level, responsibilities, and workload have been addressed by a few national societies. However, data are lacking from the embryologists’ viewpoint at a global level about their profession. Qualitative data-analysis methods provide thick, rich descriptions of subjects’ thoughts, feelings, and lived experiences but can be time-consuming, labor-intensive, and prone to bias.

Study design, size, duration

A questionnaire was prepared using SurveyMonkey online software (SurveyMonkey, Inc., USA) and distributed to IVF lab professionals through embryology societies, online social media, and email databases. The questionnaire consisted of open-ended questions focused on identifying problems faced by embryologists at the clinic, in the profession, and in a personal level, as well as questions about their career outlook. The survey was active from May 2016 until February 2017. From 73 countries, 720 responses were obtained.

Participants/materials, setting, methods

Using natural language processing (NLP), the top 15 most frequently used keywords were identified and correlated with each other. Stronger correlation (≥0.5) between semantically similar words expressing a strong signal from each answer, and their usage was further analyzed for positive versus negative sentiment. By normalizing the frequency of positive/negative samples for each keyword as a percentage, “sentiment wheels” were produced, identifying the key concepts that respondents answered and quantifying how they felt about them.

Main results and the role of chance

The responses received were from 80% private, 17% public and 3% other ART settings distributed all over the world. From the embryologists’ viewpoints reported and after the NLP processing it was shown that the common topics related to strong negative sentiments were: embryologists’ remuneration (0.6) at the Clinic level; certification (0.7), recognition (0.5), respect (0.5), learn (0.5) and experience (0.5) at the Professional level; and remuneration (0.7), emotional (0.5) dealing (0.5) at the Personal level. Renumeration was reported and strongly related to embryologists’ viewpoint at both the clinic and personal level in combination with the need for certification, recognition and ongoing development at the Professional level. Moreover, the NLP processing demonstrated that the common topics on career goal analysis related to strong positive sentiments were: teaching (0.7), education (0.7), and continuation (0.5) all three topics are compatible with a professional orientation open to ongoing development and practice advancement. The NLP and the manual data analysis project an image of the typical embryologist as a knowledge seeking professional who is deeply dedicated to the job but feels the need for professional development and suffers some lack of recognition and feels in some cases not fairly treated as an employee.

Limitations, reasons for caution

The data obtained is limited. Only one natural language processing model was used to analyze the results. Different analysts using other methods may have different results. For these reasons, the results should be interpreted with caution.

Wider implications of the findings: It is important to focus on the lab as an organization and not just a service for the patients in treatment at the moment. The NLP results ultimately obtained may help streamline professional satisfaction efforts, and guide future quality management strategies

Trial registration number

Not applicable

P–251 To collapse or not to collapse blastocysts before vitrification? A matched case-control study on single vitrified-warmed blastocyst transfers

Study question

Does laser-induced artificial blastocoel collapse result in better blastocyst cryopreservation survival and higher live birth rate (LBR) in comparison with intact counterparts?

Summary answer

Compared to vitrification of intact blastocysts, collapsed blastocysts resulted in higher survival and for 5% higher LBR. Neonatal outcomes were comparable in both groups.

What is known already

Blastocysts have long been considered a stage that is suboptimal for freezing-thawing procedures due to their high fluid content and different cell types. The development of a modified vitrification technique has enabled blastocysts to better survive cryopreservation compared to a slow freezing procedure. Many studies on the optimization of cryopreservation of blastocysts have mentioned the need for artificial collapsing of the blastocoel prior to cryopreservation, thereby reducing the risk of intracellular ice-crystals formation. However, the effectiveness of artificial collapsing on blastocyst survival rate, single vitrified-warmed blastocyst transfer (SVBT) outcome and on safety of such intervention remains to be confirmed.

Study design, size, duration

A retrospective matched case-control study of transfers of single blastocysts being artificially collapsed (case) or intact (control) before vitrification. A sample size of 306 cycles in both arms was needed to achieve 80% power to detect a difference between the groups of 10% with P < 0.05. Controls were matched to cases on a 1:1 ratio by female age, parity, fresh and frozen cycle protocol, blastocyst age and quality, getting 309 pairs of cases and controls.

Participants/materials, setting, methods

Artificial collapsing was introduced into clinical practice gradually. In fresh IVF cycles (performed in university clinic from 2012 until 2014) with supernumerary blastocysts, half of the blastocysts were randomly selected before vitrification for laser-induced artificial collapsing. The other half was vitrified in intact form. Only the first transfers of a single vitrified-warmed blastocyst (n = 818) were included in the study. By matching, 309 pairs of collapsed (study) and intact (control) SVBTs were identified.

Main results and the role of chance

Both groups were comparable by their characteristics in indications, female age, type and length of ovarian hyperstimulation, insemination method in fresh cycle, protocol for warmed blastocyst transfer, blastocyst quality and day of blastocyst vitrification. Survival rates in case and control group ((309/316) 97.8% and (309/323) 95.7%; P = 0.13) were comparable, but optimal survival rates (100% survival and re-expansion after warming) was significantly higher in artificial collapse group ((247/316) 78.2% and (225/323) 69.7%; P = 0.01). Clinical pregnancy rates ((120/309) 38.8% and (110/309) 35.6%; P = 0.4), miscarriage rates ((15/120) 12.5% and (24/110) 21.8%; P = 0.06) and LBR per transfer ((100/309) 32.4% and (85/309) 27.5%; P = 0.19) or LBR per warmed blastocyst ((100/316) 31.6% and (85/323) 26.3%; P = 0.14) were not statistically different between case and control groups. Since the study was powered to detect a 10% difference, the possibility of type 2 error cannot be excluded. Perinatal outcomes were available for 175 live births. There were 10.5% (10/95) preterm births in the study group vs. 16.3% (13/80) in control group (P > 0.05). Birth weights (3,308 g (SD 592 g) vs 3,308 g (SD 738 g) and sex ratio (50.7% vs 49.2% boys) were also comparable between both groups (P > 0.05). There were no major malformations detected in the study population.

Limitations, reasons for caution

The research is retrospective, but the cycles from both groups were performed in the same time period. The groups were balanced according to all possible confounders. Blastocysts for vitrification were first categorized by quality groups and embryos from each category were randomized for collapsing or for remaining intact.

Wider implications of the findings: No significant difference was found in live births by this sample size. Nevertheless, increasing the success by 5% with the introduction of artificial collapsing can be an important step towards optimizing of blastocyst cryopreservation. To confirm a 5% improvement in results, a sample size of > 2500 cases would be needed.

Trial registration number

The study has been approved by the National Ethics Committee of the Republic of Slovenia (0120–204/2016–2).

Design of a drug delivery system with bimodal pH dependent release of a poorly soluble drug

A delivery system which provides bimodal pH dependent release of poorly water soluble carvedilol in gastric and intestinal environment was designed. Preparation of solid dispersion with porous silica ensured a significantly higher dissolution rate of carvedilol in acidic and alkaline media in comparison to pure drug, while granulation of that solid dispersion with enteric polymer dispersion resulted in diminished immediate release in acidic media and fast release of the remaining drug in alkaline media. The ratio in quantities of first vs. second release was controlled with amount of enteric polymer dispersion used for granulation process. Desired 25 mg release of carvedilol at pH values 1.2 and 6.8 was achieved when 1.80 g of polymer per 1.0 g of solid dispersion (drug to silica ratio= 0.25 g : 2.0 g) was used.

Influence of atmospheric versus reduced oxygen concentration on development of human blastocysts in vitro: a prospective study on sibling oocytes

Numerous studies show the beneficial effect of reduced oxygen on the culture of animal embryos in vitro. However, few similar studies have been carried out in humans, and the conclusions from these were contradictory. Using sibling human oocytes, a prospective study was carried out to analyse the effect of 5 and 20% oxygen on prolonged development of embryos. The outcomes measured were fertilization rate and proportion of morphologically optimal embryos, blastocysts and optimal blastocysts developing on day 5. The results were analysed separately for the group of IVF (n = 988 oocytes) and ICSI (n = 928 oocytes) cycles. It was found that low oxygen did not influence fertilization, but in comparison with 20% oxygen, it resulted in a significantly higher proportion of embryos being optimal on day 3 after IVF (59 versus 43.2%; P < 0.001) as well as after ICSI cycles (51.2 versus 28.5%; P < 0.001). In both methods, the lower oxygen concentration improved the blastulation rate (73.2 versus 63.1%; P < 0.05 and 67.4 versus 54.7%; P < 0.001) and increased the proportion of embryos reaching the stage of expanded blastocyst with normal inner cell mass on day 5 (31.1 versus 14.6%; P < 0.001 and 18.9 versus 11.4%; P < 0.01). The ratio of successful embryo development to optimal blastocyst stage on day 5 of culture, calculated for two oxygen concentrations, was 2.1 for IVF and 1.7 for ICSI, in favour of lower oxygen tension.

In vitro fertilization program based on programmed cycles monitored by ultrasound only

OBJECTIVE

Programmed oocyte retrieval was performed in order to make the in vitro fertilization (IVF) program cheaper and work of the IVF team easier.

METHOD

In a group of 77 patients included in the IVF program, the menstrual cycle was modified with estrogen-progesterone contraceptive pills. For this reason, it was possible to start the stimulation protocol in all patients on the same day. The stimulation protocol was a combination of clomiphene (100 mg) for 5 days and HMG (150 IU) every other day. Cycles were monitored by ultrasound only.

RESULT

The implantation rate per embryo transfer was 22.4%. The number of embryos per embryo transfer was low (2.6 +/- 1.4) and eliminated the need for cryopreservation. Fertilization rate (82%) and embryo transfer rate (87%) were high. The take home baby rate was 14.3%.

CONCLUSION

Seventy percent of all punctures were performed in 3 days in the middle of the week. In our conditions, programmed oocyte retrieval is associated with significant economic benefits.

Is there any benefit from the culture of a single oocyte to a blastocyst-stage embryo in unstimulated cycles?

BACKGROUND

The aim of the study was to test the influence of 2- and 5-day cultivation of a single oocyte on the pregnancy rate in a non-stimulated cycle.

METHODS

A retrospective chart review of 391 consecutive patients undergoing IVF and intracytoplasmic sperm injection in unstimulated cycles was performed. The embryos were kept in MediCult universal IVF medium for day 2 transfers and in BlastAssist System for day 5 transfers.

RESULTS

The oocyte recovery rate in the group for 2-day cultivation and in the group for 5-day cultivation was similar, being 79.4 (162/204) and 83.6% (154/187) respectively. The same is true of the fertilization rate (73.8 versus 77.7%). The blastulation rate was 52.8%. The embryo transfer rate per cycle was higher when day 2 embryos were transferred: 64.8% (105/162) compared with 35.7% (55/154) if blastocyst-stage embryos were transferred. The pregnancy rate per transferred embryo was higher when a blastocyst was transferred (40.0%) instead of a day 2 embryo (23.8%).

CONCLUSION

The expected pregnancy rate calculated per embryo available on day 2 of cultivation was similar in both groups (23.8 versus 22.2%) and it was not affected by oocyte culture to the blastocyst stage.

Three protocols for monitoring follicle development in 587 unstimulated cycles of in vitro fertilization and intracytoplasmic sperm injection. A comparison

OBJECTIVE

To test the adequacy of unstimulated cycles for intracytoplasmic sperm injection (ICSI) and in vitro fertilization (IVF) and to evaluate implantation and pregnancy rates in three monitoring protocols.

STUDY DESIGN

A retrospective chart review of 587 patients undergoing IVF and ICSI in unstimulated cycles was performed. In the first group (protocol A), all cycles were monitored by ultrasound only. Human chorionic gonadotropin (hCG) was given when the mean follicle diameter reached 18 mm. In protocol B, hCG was given when serum estradiol (E2) or follicle diameter reached the critical value (0.91 nmol/L and 18 mm). With a smaller follicle diameter, the E2 level had to be higher, and vice versa. In protocol C, hCG was administered when the serum E2 was > 0.49 nmol/L and follicle diameter at least 15 mm. Cycles with positive luteinizing hormone in urine before hCG was given were cancelled.

RESULTS

The cancellation rate was lower in protocol C (33/335, 9.8%) than protocol B (42/151, 27.8%) and A (41/101, 40.5%). In protocol C the pregnancy rate per cycle was higher with IVF (n = 219) and ICSI (n = 116) cycles (10.5% and 12.1%) than when protocol B was used (3.8% and 4.3%). The pregnancy rate per transfer was highest when protocol C was used in the IVF (23/105, 21.9%) and ICSI group (14/53, 26.4%).

CONCLUSION

Unstimulated cycles monitored by serum E2, urinary luteinizing hormone and ultrasound can produce an acceptable pregnancy rate after IVF and ICSI.

Value of the serum estradiol level on the day of human chorionic gonadotropin injection and on the day after in predicting the outcome in natural in vitro fertilization/intracytoplasmic sperm injection cycles

OBJECTIVE

To predict the risk of premature ovulation and possibility of pregnancy in natural IVF/ICSI cycles on the basis of the estradiol (E2) level on the day of hCG injection and on the day after.

DESIGN

A prospective study.

SETTING

Hospital research program.

PATIENT(S)

One hundred sixty-four women undergoing 305 IVF/ICSI natural cycles.

INTERVENTION(S)

Serum E2 levels were measured approximately 12 h before (day 0) and 12-17 h after hCG administration (day 1).

MAIN OUTCOME MEASURE(S)

E2 levels on day 0 and day 1, the ratio of the day 1 to day 0 levels, and cycle outcome.

RESULT(S)

In cycles with premature ovulation and in conception cycles, the average E2 level on day 0 was statistically significantly higher than in other cycles, whereas the E2 ratio was statistically significantly lower. Multiple logistic regression was used to determine the connection of the E2 level on day 0 (B0 = -0.742, B = 2.147, P =.01) and the E2 ratio (B0 = -0.742, B = -3.135, P<.001) with premature ovulation. Only the E2 ratio (B0 = 0.659, B = -2.209, P =.0068) was significantly connected with conception.

CONCLUSION(S)

In predicting the outcome of natural IVF/ICSI cycles, the importance lies not in the E2 level on the day of hCG administration or on the day after, but rather in the E2 ratio.

Subendometrial contractility is not predictive for in vitro fertilization (IVF) outcome

OBJECTIVES

The aim of the study was to investigate whether endometrial thickness, endometrial pattern, endometrial movement and serum estradiol and progesterone affect the outcome of in vitro fertilization.

METHODS

Prospectively collected data of endometrial thickness, endometrial pattern and subendometrial activity were analyzed in 122 consecutive in vitro fertilization cycles. All measurements were made on the day of hCG administration (day -2), day of embryo transfer (day +2), day +6 and day +12.

RESULTS

It would appear that pregnant women tend to have a thicker endometrium on day +12 than non-pregnant women. There appears to be no appreciable difference between pregnant and non-pregnant women in endometrial movement and thickness, nor in serum estradiol and progesterone on day +2 and day +6. In combining three echographic variables (thickness, pattern and movement) and hormone level (estradiol and progesterone), only progesterone on day +12 could be used to predict the outcome.

CONCLUSIONS

Subendometrial contractility plays no important role in implantation on the day of embryo transfer or 4 days later.

Simplification of the clinical phase of IVF and ICSI treatment in programmed cycles

OBJECTIVE

To evaluate the success of a protocol for controlled ovarian hyperstimulation allowing patient self-selection into groups for ovulation stimulation planned 8 weeks and more in advance following cycle synchronization, drug self-administration as well as a reduced number of folliculometries.

METHODS

A total of 714 patients received the same stimulation protocol. In 260 cases GnRH-a was applied daily and in 454 as depot. In all patients FSH-HP was self-administered subcutaneously for ovarian stimulation. In 316 patients IVF and in 398 patients ICSI was performed.

RESULTS

The delivery rate per started cycle was higher in patients receiving depot GnRH-a in the IVF and ICSI group (30.2 vs. 23.4) than in those receiving subcutaneous GnRH-a (20.2 vs. 22.1).

CONCLUSION

Programming of the IVF/ICSI cycle greatly simplifies treatment. A comparison of pregnancy rate and delivery rate per cycle between depot and subcutaneous daily application of GnRh-a did not confirm any statistically significant difference.

Configuration of maternal and paternal chromatin and pertaining microtubules in human oocytes failing to fertilize after intracytoplasmic sperm injection

The microtubules and chromosomes of 180 human oocytes failing to fertilize after intracytoplasmic sperm injection were observed in order to establish how sperm chromatin and sperm astral microtubule configuration is related to the phases of oocyte cell cycle, and to find the defects in those structures causing fertilization arrest. As many as 125 (69%) oocytes were arrested at metaphase II. In one-fourth of them, damages of the second meiotic spindle were noted. In their cytoplasm intact sperm were found in 38 (30%) cases, a swollen sperm head in 36 (29%) and prematurely condensed sperm chromosomes (G1-PCC)-a result of active mitosis promoting factor (MPF)-in 51 (41%) cases. G1-PCC were mostly (73%) surrounded by the bipolar paternal spindle instead of astral microtubules. A male pronucleus was never presented in metaphase II oocytes. In 19 (11%) oocytes, arrested at anaphase II, no intact sperm were found. As many as 9 (47%) oocytes contained sperm in G1-PCC form, which proves that anaphase II oocytes mostly retain active MPF, despite oocyte activation. As many as 78% of 36 monopronucleate oocytes contained sperm, with delay in the process of sperm nucleus decondensation. Sperm in G1-PCC form and a bipolar paternal spindle were never found in monopronucleate oocytes. From this we conclude that sperm that does not activate the oocyte may continue decondensing the chromatin, but the oocyte prevents male pronucleus formation before the female one, mostly by causing PCC in the sperm and by duplicating the sperm centrosome. Mol. Reprod. Dev. 55:197-204, 2000.

Number of oocytes retrieved and resulting pregnancy. Risk factors for ovarian hyperstimulation syndrome

OBJECTIVE

To test whether the risk of developing clinically significant ovarian hyperstimulation syndrome (OHSS) is related to the number of oocytes retrieved by puncture and the resulting pregnancy and to determine the most suitable cutoff limit of the number of oocytes in predicting OHSS.

STUDY DESIGN

The study included 973 patients who underwent ovarian stimulation for in vitro fertilization or intracytoplasmic sperm injection. Using the classification of Schenker and Weinstein, we identified patients who developed moderate and severe OHSS. By multiple logistic regression we established the risk of moderate or severe OHSS development in relation to the number of oocytes retrieved and the resulting pregnancy. A receiver operator characteristic curve was constructed to describe the relation between sensitivity and the false positive rate for the number of oocytes retrieved in the prediction of OHSS.

RESULTS

We identified 35 (3.6%) patients who developed OHSS, 8 (0.8%) severe and 27 (2.8%) moderate. The risk of developing OHSS increased with the number of oocytes retrieved (odds ratio = 1.14) and with pregnancy (odds ratio = 1.14). The most suitable limit for predicting OHSS was 10 oocytes, with 81.9% specificity and 48.6% sensitivity. The risk of OHSS development in cycles with < or = 10 oocytes and no conception was 1.31% and, with conception, 5.12%. The risk of OHSS development in cycles with > 10 oocytes and no conception was 4.43% and with conception, 15.93%.

CONCLUSION

The risk of OHSS development increases with the number of oocytes retrieved and with pregnancy. The most suitable limit for predicting OHSS is 10 oocytes; however, due to low sensitivity, it is also necessary to consider other factors when establishing the increased risk of OHSS.

c-Src activation plays a role in endothelin-dependent hypertrophy of the cardiac myocyte

Activation of the atrial natriuretic peptide (ANP) gene is regarded as one of the earliest and most reliable markers of hypertrophy in the ventricular cardiac myocyte. We have examined the role of the nonreceptor tyrosine kinases in the signaling mechanism(s) leading to hypertrophy using human ANP gene promoter activity as a marker. Endothelin (ET), a well known hypertrophic agonist, increased activity of c-Src, c-Yes, and Fyn within minutes and promoted a selective redistribution of each of these kinases within the cell. Overexpression of c-Src effected a significant increase in activity of a cotransfected human ANP promoter-driven chloramphenicol acetyl transferase reporter, while expression of either c-Yes or Fyn was considerably less effective in this regard. ET-dependent stimulation of the human ANP gene promoter was partially inhibited by co-transfection with dominant negative Ras or dominant negative Src or Csk or by treatment with the potent Src family-selective tyrosine kinase inhibitor PP1, suggesting that the Src family kinases are involved in signaling ET-dependent activation of this promoter. Both ET- and Src-dependent activation of the ANP promoter required the presence of a CArG motif in a serum response element-like structure between -422 and -413 but did not appear to require assembly of a ternary complex for full activity. These findings support a role for Src in the activation of ANP gene expression and suggest that this kinase may contribute in an important way to the signaling mechanisms that activate hypertrophy in the cardiac myocyte.

[Evaluation of embryotoxicity of materials used in the IVF laboratory]

It has been established that the quality of water for the preparation of culture media has an essential influence on the percentage of two cell-stage mouse embryos developing successfully until the blastocyst stage. The quality of media prepared with bidistilled water (p less than 0.001) is inferior to that prepared with bidestilled demineralized water (p less than 0.02). Best results were attained by using the medium prepared with Nanopure water (Barnstead), in which 73.2% of embryos developed into blastocysts. There was no statistically significant difference between this medium and the commercial liquid medium (Sigma), in which 83.1% of embryos developed into blastocysts. The age of the medium and the percentage of added serum have no statistically significant influence on the outcome of the test. Contact of the medium with the syringe containing a black rubber piston proved explicitly embryotoxic (p less than 0.001).

[Results of the IVF/GIFT program in Maribor]

The results of the IVF/GIFT programme for 1989 in Maribor are presented. During this period 4 clinical pregnancies were attended by the IVF procedure and one by GIFT and ZIFT each. In the IVF procedure the highest percentage of pregnancies was obtained in the group of women with the tubal factor of infertility (n = 34) where 4 clinical pregnancies on 22 ET were registered (18.1%). Cycle synchronisation with contraceptives, followed by stimulation with CC-HMG proved to be the most successful protocol for the cycle stimulation. With this protocol, pregnancy was attained in 4 of 19 stimulated cycles (21.0%). In the spontaneous cycles (n = 17) no pregnancy was registered.

Suppression of neuroleptic-induced persistent abnormal movements in Cebus apella monkeys by enantiomers of 3-PPP

Effects of the enantiomers of the dopamine (DA) autoreceptor agonist 3-PPP (0.5-8.0 mg/kg body weight, i.m.) were studied in three Cebus apella monkeys with persistent abnormal movements induced by prior long-term treatment with fluphenazine enanthate. In 2 of the animals, (-)-3-PPP abolished the abnormal movements while producing only negligible acute motor effects (trembling and stereotypy). (+)-3-PPP, administered to one of these monkeys, also produced a dose-dependent suppression of the persistent abnormal movements, along with the appearance of acute motor signs including tongue protrusions, hyperkinesia, and stereotypy; at the highest dose, there was a biphasic effect. In the first phase, there were pronounced acute motor signs but no persistent abnormal movements. In the second phase, there were neither acute nor persistent abnormal movements. One monkey was unaffected by (-)-3-PPP or low doses of (+)-3-PPP; a higher dose (4 mg/kg) produced hyperkinesia and increased persistent abnormal movements in one experimental setting. The suppression of neuroleptic-induced persistent abnormal movements by 3-PPP enantiomers may be related to their ability to act as autoreceptor agonists, while the acute motor signs produced by higher doses of (+)-3-PPP may be due to activation of postsynaptic DA receptors. The present findings suggest that (-)-3-PPP and drugs with a similar pharmacological profile might be effective as symptomatic treatments for tardive dyskinesia, with little chance of inducing acute extrapyramidal side-effects.

Effect of neuroleptics and of potential new antipsychotic agents (MJ 13859-1 and MJ 13980-1) on a monkey model of tardive dyskinesia

Two adult female cebus apella monkeys with persistent tardive dyskinesia (TD) were given acute i.m. injections of reference neuroleptics (chlorpromazine, haloperidol, thioridazine, and clozapine) or of potential new antipsychotic agents (MJ 13859-1 and MJ 13980-1). The drugs were assessed for their ability to modify TD symptoms or to produce acute neurologic reactions. Effects of three doses of MJ 13859-1 administered orally were also examined. At the doses used, thioridazine and clozapine had little or no effect. Chlorpromazine, haloperidol, MJ 13859-1 and MJ 13980-1 reduced or abolished TD and concomitantly produced hypokinesia, akinesia, mask expression, trembling, and reduced response to stimuli. Haloperidol also produced a mildly abnormal posture. In addition to the above effects, MJ 13859-1 also produced "slow motion" movement, sustained bizarre postures, sudden falls, and episodes of severe rigidity with trembling.

Lack of clinically significant improvement of patients with tardive dyskinesia following phosphatidylcholine therapy

A double-blind controlled study was undertaken to examine the value of phosphatidylcholine as a treatment for tardive dyskinesia (TD) in 19 psychiatric patients. All patients were maintained on their usual psychotropic medication throughout the entire study. In addition, they were given either phosphatidylcholine (30 g/day) or placebo for 6 weeks. Thirteen of the patients received the crossover treatment for 6 weeks, after which 10 of the 13 were continued on the crossover medication for an additional 6 weeks. At the end of the study, 5 patients had received phosphatidylcholine for 12 weeks and another 12 patients had received the drug for only 6 weeks. Plasma and red blood cell choline levels were monitored every 3 weeks as a measure of compliance. Although some patients showed clinical improvement of their TD, the results did not differ significantly between active drug and placebo. This was in spite of a marked elevation of plasma and red blood cell choline (up to 300% for the Lafayette Clinic patients and up to 400% for the patients from the Ypsilanti Regional Psychiatric Hospital) during treatment with phosphatidylcholine. Side effects of the drug included occasional gastrointestinal upsets and diarrhea but, in general, the medication was tolerated very well. The results indicate that large doses of phosphatidylcholine of soya origin are of no clinical value in treating symptoms of TD in spite of very large increases in blood choline.

Fluphenazine-induced acute and tardive dyskinesias in monkeys

Five Cebus apella monkeys were treated with biweekly injections of fluphenazine enanthate (0.1-3.2 mg/kg IM). Three of these completed 1 full year of treatment, one injured its leg after 6 months of treatment and was killed, and another died of unknown causes after 9 months of treatment. All monkeys displayed abnormal movements corresponding to the early appearing extrapyramidal symptoms of neuroleptic-treated patients. These consisted initially of slowing or absence of volitional movement, trembling of the hands, trembling of the entire body, and general drowsy behavior. As treatment progressed, a variety of abnormal postures and movements appeared after each injection that were not exacerbated by drug withdrawal and, as tested at the end of the year, could be abolished or prevented with benztropine mesylate (0.2-0.5 mg/kg IM). The three monkeys that completed 1 year of treatment with fluphenazine were then withdrawn from the drug. After withdrawal, all three developed movements similar in appearance to those of patients with tardive dyskinesia (TD). Reinstitution of fluphenazine treatment, as tested in one monkey, abolished all movements resembling TD.

A monkey model of tardive dyskinesia (TD): evidence that reversible TD may turn into irreversible TD

Three Cebus apella monkeys were treated with biweekly injections of fluphenazine enanthate for 1 year. Two distinct motor syndromes were produced. The first consisted of acute dystonic, dyskinetic, parkinsonian, and akathisia-like reactions, which worsened after each injection, were not exacerbated by drug withdrawal, and could be abolished or prevented with benztropine. The second appeared after cessation of neuroleptic treatment and consisted of abnormal movements very similar to those of patients with tardive dyskinesia (TD). This syndrome was abolished completely by reinstitution of fluphenazine treatment. One monkey was given a second and third course of fluphenazine, each course lasting 4 weeks. The second syndrome was seen after but not during each course and remained robust for a longer period after the third than after the first or second courses of treatment. We conclude that the first syndrome is analogous to the early appearing extrapyramidal symptoms of neuroleptic-treated patients and that, according to preliminary evidence, reversible TD may turn into irreversible TD with continued periods of on and off neuroleptic treatment.

Naloxone enhancement of DMT and LSD-25 induced suppression of food-rewarded bar pressing behavior in the rat

The narcotic antagonist naloxone was tested to determine its possible interaction with N,N-dimethyltryptamine (DMT) and lysergic acid diethylamide-25 (LSD) in adult male Holtzman rats trained to press a bar on a fixed-ratio four schedule (FR4), i.e., every fourth press earned a reward of 0.01 ml sugar sweetened milk. LSD (0.1 mg/kg) or increasing doses of DMT (1.0, 3.2, and 10.0 mg/kg) were administered i.p. to disrupt food-rewarded fixed ratio bar pressing in a dose related fashion. Pretreatment (5--10 min) with behaviorally ineffective doses of naloxone (1.0--5.6 mg/kg) dramatically enhanced the effects of DMT and LSD. The content of DMT in the brain and liver of rats injected with DMT alone (10 mg/kg) and with a 5 min pretreatment of naloxone (3.2 mg/kg) was determined by radiochemical analysis at 30 and 90 min after 14C-DMT injection. There was no significant difference for either brain or liver 14C-DMT levels when control DMT rats were compared with the naloxone pretreated rats. These results seem to rule out interference by naloxone with the metabolism of DMT as a mechanism of the observed behavioral potentiation.

Interactions of partial LSD analogs with behavioral disrupting effects of LSD and DMT in the rat

Adult male Holtzman rats were trained to barpress on a schedule whereby every fourth press earned a reward of 0.01 ml of sugar-sweetened milk (FR4). After an i.p. injection of LSD (0.1 mg/kg) or DMT (3.2 or 10 mg/kg) such barpressing is abolished completely and resumed, usually within an hour, at a rate near the preinjection control rate of pressing. It continues at a steady, uninterrupted pace until the animals are removed from the operant chamber one-half hour later. A series of N,N-diethylnipecotamide derivatives were synthesized and tested for their ability to modify the disruptive effect of these hallucinogens. N,N-diethylbutyramide (DBA) and 1-methyl-1,2,5,6-tetrahydropyridine-3-(N,N-diethylcarboxamide) (THPC) were also tested. Pretreatment with a single i.p. injection of any of these compounds (5--40 mg/kg) either had no effect on or else prolonged the duration of hallucinogen-induced cessation of barpressing.

Effects of various neuroleptics on rabbit hyperthermia induced by N, N-Dimethyltryptamine (DMT) and d-amphetamine

The effects of various neuroleptics were studied on N, N-dimethyltryptamine (DMT, 3.2 mg/kg) and d-amphetamine (3.2 mg/kg) induced hyperthermia in the rabbit. Complete dose-effect curves were obtained. The order of potency for antagonism of DMT-induced hyperthermia was: methiothepin greater than octoclothepin greater than or equal to oxyprothepin greater than perathiepin greater than dokloxythepin greater than mianserine greater than loxapine greater than oxypertine greater than chlorpromazine greater than pipamperone greater than fluphenazine greater than thiothixene greater than haloperidol greater than molindone. The order of potency for antagonism of d-amphetamine hyperthermia was: haloperidol greater than chlorpromazine greater than oxypertine greater than octoclothepin and methiothepin. For these five drugs, the order of potency for antagonism of amphetamine hyperthermia was the reverse of the order for antagonism of DMT hyperthermia. Methiothepin reduced d-amphetamine-induced hyperthermia effectively at a very high dose (0.32 mg/kg) and variably at lower doses. The results indicate that neuroleptics differ markedly in their specificity of antagonism of DMT and d-amphetamine which may act through different neurotransmitter mechanisms (tryptaminergic vs. adrenergic).

Tolerance and limited cross-tolerance to the effects of N, N-dimethyltryptamine (DMT) and lysergic acid diethylamide-25 (LSD) on food-rewarded bar pressing in the rat

Lysergic acid diethylamide=25 (LSD) and N,N-dimethyltryptamine (DMT) abolish food-rewarded, fixed-ratio bar pressing by rats in a dose-related fashion. Adult male Holtzman rats trained to press a bar (respond) for milk reward on a 4-response fixed-ratio schedule were given i.p. injections of 3.2 or 10 mg/kg of DMT every 2 hours for 21 days. Every 24 hours the animals were placed in operant chambers for 30 minutes before a scheduled injection and were left in the chambers for 30 to 80 minutes after. During the first week of chronic treatment, daily bar pressing worsened progressively until the 6th day of the series, at which time rats in the 10 mg/kg group did not bar press at all. As the chronic injections continued, rates of bar pressing gradually increased until responding was not disrupted at all by an injection of DMT. Rats in the 3.2 mg/kg group showed cross-tolerance to an injection of LSD (0.1 mg/kg). Another group of rats was made partially tolerant to the disruptive effects of LSD (0.1 mg/kg i.p.) on bar pressing with a series of injections given once per day for 21 days and then three times per day for the next 4 days. Cross tolerance was not demonstrated to a challenge injection of 10 mg/kg of DMT. The LSD injections were continued for another 3 to 5 days until the animals were completely tolerant to the LSD. They then displayed cross-tolerance to 3.2 mg/kg of DMT.