Quantifying differentiation of progenitor populations using cerebral organoid models for neurodevelopmental disorders.

Neurodevelopmental disorders are characterized by complex phenotypes that often result from concomitant dysregulation of cell proliferation, differentiation, or other crucial developmental processes. Here, we present a protocol to quantify differentiation of progenitor populations during early stages of neurogenesis in induced pluripotent stem cell (iPSC)-derived cerebral organoids. We describe steps for organoid differentiation and maturation, sample preparation, immunofluorescence, and imaging and analysis using epifluorescence microscopy. This protocol can be used to compare cerebral organoids from control and patient-derived iPSCs. For complete details on the use and execution of this protocol, please refer to Rakotomamonjy et al. (2023).1.

Estimating population density of insectivorous bats based on stationary acoustic detectors: A case study.

Automated recording units are commonly used by consultants to assess environmental impacts and to monitor animal populations. Although estimating population density of bats using stationary acoustic detectors is key for evaluating environmental impacts, estimating densities from call activity data is only possible through recently developed numerical methods, as the recognition of calling individuals is impossible.We tested the applicability of generalized random encounter models (gREMs) for determining population densities of three bat species (Common pipistrelle Pipistrellus pipistrellus, Northern bat Eptesicus nilssonii, and Natterer's bat Myotis nattereri) based on passively collected acoustical data. To validate the results, we compared them to (a) density estimates from the literature and to (b) Royle-Nichols (RN) models of detection/nondetection data.Our estimates for M. nattereri matched both the published data and RN-model results. For E. nilssonii, the gREM yielded similar estimates to the RN-models, but the published estimates were more than twice as high. This discrepancy might be because the high-altitude flight of E. nilssonii is not accounted for in gREMs. Results of gREMs for P. pipistrellus were supported by published data but were ~10 times higher than those of RN-models. RN-models use detection/nondetection data, and this loss of information probably affected population estimates of very active species like P. pipistrellus.gREM models provided realistic estimates of bat population densities based on automatically recorded call activity data. However, the average flight altitude of species should be accounted for in future analyses. We suggest including flight altitude in the calculation of the detection range to assess the detection sphere more accurately and to obtain more precise density estimates.

mTOR/AMPK signaling in the brain: Cell metabolism, proteostasis and survival.

The mechanistic (or mammalian) target of rapamycin (mTOR) and the adenosine monophosphate-activated protein kinase (AMPK) regulate cell survival and metabolism in response to diverse stimuli such as variations in amino acid content, changes in cellular bioenergetics, oxygen levels, neurotrophic factors and xenobiotics. This Opinion paper aims to discuss the current state of knowledge regarding how mTOR and AMPK regulate the metabolism and survival of brain cells and the close interrelationship between both signaling cascades. It is now clear that both mTOR and AMPK pathways regulate cellular homeostasis at multiple levels. Studies so far demonstrate that dysregulation in these two pathways is associated with neuronal injury, degeneration and neurotoxicity, but the mechanisms involved remain unclear. Most of the work so far has been focused on their antagonistic regulation of autophagy, but recent findings highlight that changes in protein synthesis, metabolism and mitochondrial function are likely to play a role in the regulatory effects of both mTOR and AMPK on neuronal health. Understanding the role and relationship between these two master regulators of cell metabolism is crucial for future therapeutic approaches to counteract alterations in cell metabolism and survival in brain injury and disease.

Mayer-Rokitansky-Küster-Hauser syndrome associated with thrombocytopenia-absent radius syndrome.

OBJECTIVE: To describe the association of Mayer-Rokitansky-Küster-Hauser (MRKH) syndrome and thrombocytopenia-absent radius (TAR) syndrome. DESIGN: Descriptive case report. SETTING: Tertiary university-affiliated care and referral facility. PATIENT(S): A 22-year-old woman with TAR syndrome referred to our department with primary amenorrhea. INTERVENTION(S): Patient history, physical and laboratory examination, diagnostic laparoscopy, and karyotyping. MAIN OUTCOME MEASURE(S): Physical features in the combination of syndromes presented. RESULT(S): Laparoscopy revealed absent uterus and complete vaginal agenesis. CONCLUSION(S): This extremely rare case might provide further evidence of a link between the development of the skeletal system and the genitourinary tract.

Insulin resistance in patients with polycystic ovary syndrome.

With a prevalence of 5%-10% the polycystic ovary syndrome (PCOS) is an exceptionally common disorder of premenopausal women. According to prospective studies, women with PCOS present abnormal glucose tolerance and diabetes mellitus in 31%-35% and 7.5%-10%, respectively. PCOS patients have a higher prevalence of cardiovascular risk factors such as hypertension, type 2 diabetes and dyslipidaemia. The rate of spontaneous abortions as well as the risk to develop gestational or type 2 diabetes is increased in PCOS. Therefore, PCOS is not only a reproductive problem but a complex endocrine disease with important health implications. The role of the glucose metabolism in PCOS, the health consequences and possible interventions are reviewed in this article.

Medical management of endometriosis: a systematic review.

Endometriosis is an important clinical problem in routine practice. Besides the problems of dysmenorrhea, dyspareunia and chronic abdominal pain, women with endometriosis are often infertile. We performed a systematic literature review on two issues: firstly, we clarified which medical treatment options have been investigated in prospective, randomized studies. Secondly, potential future treatments, still being preclinically investigated, were examined. A meta-analysis was not possible as the studies varied too much in their protocols and inclusion and exclusion criteria, as well as in the drugs and doses administered. Gonadotropin-releasing hormone (GnRH) agonists, progestins and oral contraceptives all appear to offer certain advantages for endometriosis patients. GnRH agonists appear to be the most effective but they are expensive and long-term treatment is not possible because of loss of bone mineral density. Estrogen add-back may offer some benefit for the clinical complaints of patients, but it may reduce the efficacy of GnRH agonists. Progestins have the best clinical profile and a good cost-effectiveness balance; however, most studies found that they were not as effective as GnRH agonists. Oral contraceptives are only effective during treatment and have a high relapse rate after therapy is completed. Future options may include the use of GnRH agonists, selective estrogen receptor modulators (SERMs) and anti-estrogens, as well as immunomodulators.

Unilateral follicular aspiration and in-vitro maturation before contralateral oocyte retrieval: a method to prevent ovarian hyperstimulation syndrome.

BACKGROUND: Five women undergoing intracytoplasmatic sperm injection (ICSI) considered to be at high risk of developing an ovarian hyperstimulation syndrome (OHSS) from March to July 2002 underwent unilateral follicular aspiration. METHODS: When >/=15 follicles of 12-15 mm diameter in each ovary and a serum estrodial level >/=2500 pg/ml was present, follicular aspiration was performed unilaterally without hCG administration. Ovarian stimulation was continued for 1-3 days in four women before human chorionic gonadotrophin (hCG) was given. In one woman hCG injection was administered at the evening after unilateral follicular aspiration. The oocyte retrieval from the contralateral ovary was performed 36 h after hCG injection. By unilateral follicular aspiration two to six germinal vesicle (GV) oocytes could be retrieved. After in-vitro maturation of those oocytes ICSI was performed. RESULTS: In four women one to two oocytes were fertilized and cryopreserved. In one case only one triploid pronucleus (3PN) was observed. At the contralateral ovum-pick up after hCG injection a median of 10 could be retrieved. After transfer of a median of 3 embryos, no pregnancy was achieved. Four of five patients developed a severe OHSS and were hospitalized for a median of 3 days. CONCLUSION: Unilateral follicular aspiration and continuation of stimulation therefore can not be recommended for the prevention of OHSS.

[Insulin resistance in polycystic ovary syndrome]. / Die Insulinresistenz beim polyzystischen Ovar-Syndrom.

With a prevalence of 5-10% the polycystic ovary syndrome (PCOS) is a common disorder of premenopausal women. According to prospective studies abnormal glucose tolerance and diabetes mellitus present in about 10.0% and 35.0% of adult women with PCOS, respectively. PCOS patients have a higher prevalence of cardiovascular risk factors such as hypertension and dyslipidaemia. The rate of spontaneous abortions as well as the risk of developing gestational diabetes is increased in PCOS. Therefore, PCOS is not only a reproductive problem, but a complex endocrine disease with important health implications. The role of glucose metabolism in PCOS, the health consequences and possible interventions are reviewed in this article.

Impact of intracytoplasmic sperm injection on the activation and fertilization process of oocytes.

Intracytoplasmic sperm injection (ICSI) is used worldwide to treat preferentially severe cases of male factor infertility. In this review, data regarding the processes of oocyte activation and fertilization in non-assisted conception, conventional IVF and ICSI are discussed. The second messenger calcium shows a typical pattern after ICSI, which is different from that after subzonal insemination (SUZI), which is closer to the conditions of normal fertilization. The onset of calcium spikes is delayed. Sometimes a monophasic calcium pattern, in animals typical for parthenogenetic activation, is observed despite normal subsequent oocyte activation. Furthermore, the frequency of spikes is higher after SUZI, and only one phase instead of two is observed after ICSI for the second onset of calcium release. These alterations may be explained by the differences in oocyte activation after ICSI, since no oolemma-sperm contact is present. Sperm decondensation also follows another pattern after ICSI: as long as residuals of the acrosome are present on the sperm head, no sperm decondensation takes place at that site. Therefore, decondensation is delayed and pronucleus formation, especially that of the male pronucleus, takes longer after ICSI as compared with conventional IVF. Since studies have shown that gonosomes are located preferentially in the apical part of the sperm nucleus, this was proposed to be an explanation for a higher incidence of gonosomal aberrations in offspring after ICSI. However, other explanations, taking clinical data like the background risk of the parents into account, can also be offered for this phenomenon. These alternative theories are more likely to be associated with a slight instead of a frank increase in gonosomal aberrations. The inheritance of paternal mitochondrial DNA seems not to be a problem after ICSI, as shown by different studies. Mitochondrial DNA can be demonstrated in embryos after conventional IVF as after ICSI up to the blastocyst stage but not in children born after ICSI. Finally, lesion of the meiotic spindle by the ICSI procedure seems not to be a problem when data from different studies are taken into account. As assumed also at the beginning of the ICSI era, the meiotic spindle is almost always located in an area of < 90 degrees deviation from the polar body axis. Therefore, intrusion of the microinjection needle at the 90 degrees position might not endanger the spindle apparatus. To conclude, several studies using different approaches might show differences in the oocyte activation pattern, the 'choreography of fertilization' and pronucleus formation after ICSI. However, this different pattern does not necessarily mean that ICSI per se is a problem for embryonal development. The different pattern can be explained by the fact that ICSI uses another means of oocyte entry than the normal fertilization process. The clinical data of a high fertilization, cleavage and implantation rate, and especially the data from newborn babies, show that ICSI is a reliable procedure.

Fertilization rate and preimplantation development after intracytoplasmic sperm injection.

Intracytoplasmic sperm injection (ICSI) is the treatment of choice in cases of male factor infertility. In the present review, all data from the literature regarding early fertlilization and preimplantation embryo development are analysed. ICSI seems to offer better fertilization rates than conventional IVF, even in the absence of a male factor and in prospective, randomized studies on sibling oocytes. Blastocyst formation is lower in ICSI than in IVF. This may be due to sublethal disturbances in oocyte architecture and function. Implantation and pregnancy rates, however, are similiar in ICSI and conventional IVF. Therefore, it can be concluded that ICSI offers a safe approach, as far as is known to date, for the treatment of male factor infertility. Embryo selection in cases of sublethal damage to oocytes seems to take place in the early preimplantation stages. Nor does the risk of monozygotic twinning, which was also proposed to be higher in ICSI compared with conventional IVF, seem to increase with this procedure.