Clarissa Velayo

Aberrant behavior of mouse embryo development after blastomere biopsy as observed through time-lapse cinematography

OBJECTIVE To analyze whether blastomere biopsy affects early embryonal growth as observed through time-lapse cinematography. DESIGN Comparative prospective study between embryos in which a blastomere was removed and embryos in which a blastomere was not removed. SETTING An experimental laboratory of the university. MAIN OUTCOME MEASURE(S) We calculated the time between blastocele formation and the end of hatching, the time between the start and end of hatching, the number of contractions and expansions between blastocyst formation and the end of hatching, and the maximum diameter of the expanded blastocyst. RESULT(S) In blastomere removal embryos, compaction began at the six-cell stage instead of at the eight-cell stage. We also found that hatching was delayed in these embryos as compared with matched controls. Moreover, the frequency of contraction and expansion movements after blastocyst formation was significantly higher in the blastomere removal group as compared with the control group. Finally, the maximum diameter of the expanded blastocyst just before hatching was not significantly different between both groups. CONCLUSION(S) These findings suggested that blastomere removal has an adverse effect on embryonic development around the time of hatching. Thus, future developments in preimplantation genetic diagnosis and screening should involve further consideration and caution in light of the influence of blastomere biopsy on embryonal growth.

Recent Advances in Fetal Electrocardiography

Since the first observations of Cremer in 1906, fetal electrocardiogram (ECG) measurements via the maternal abdominal wall have remained a formidable challenge for clinical technicians and engineers in the cutting-edge field of information theory. Previous obstacles in extracting fetal ECG still complicate their acquisition at the present. These include three main difficulties for non-invasive measurement of fetal ECG: first, the low signal to noise ratio; second, the lack of a standard lead system for fetal ECG on the maternal abdomen; and third, the factor of fetal movement or non-stationarity during recording. A new extraction system based on blind source separation with reference signals (BSSR) was utilized and our detection rates, both off-line (91%) and on-line (60%), in pregnancies of 20 to 41 weeks of gestation have shown a marked improvement from earlier attempts. With this development, we discuss the potentials and limitations of this new system.

Understanding congenital heart defects through abdominal fetal electrocardiography: Case reports and clinical implications

Aims:  Congenital heart defects are the most common fetal structural anomalies of which a significant number remain unrecognized during postnatal life. Fetal electrocardiography (FECG) is an ideal clinical tool to complement ultrasonography for the screening and management of these cases where early and accurate diagnoses would allow definite rather than palliative treatment. The objective of this report was to correlate the particular FECG results found with the different types of congenital heart defects involved and to further demonstrate the usefulness of FECG in clinical settings.

Evaluation of cardiac performance by abdominal fetal ECG in twin‐to‐twin transfusion syndrome

To investigate fetal cardiac performance by abdominal fetal electrocardiography (ECG) in monochorionic diamniotic pregnancies with twin‐to‐twin transfusion syndrome (TTTS‐MCDA).

Intrauterine Ischemic Reperfusion Switches the Fetal Transcriptional Pattern from HIF-1α- to P53-Dependent Regulation in the Murine Brain

Ischemic reperfusion (IR) during the perinatal period is a known causative factor of fetal brain damage. So far, both morphologic and histologic evidence has shown that fetal brain damage can be observed only several hours to days after an IR insult has occurred. Therefore, to prevent fetal brain damage under these circumstances, a more detailed understanding of the underlying molecular mechanisms involved during an acute response to IR is necessary. In the present work, pregnant mice were exposed to IR on day 18 of gestation by clipping one side of the maternal uterine horn. Simultaneous fetal electrocardiography was performed during the procedure to verify that conditions resulting in fetal brain damage were met. Fetal brain sampling within 30 minutes after IR insult revealed molecular evidence that a fetal response was indeed triggered in the form of inhibition of the Akt-mTOR-S6 synthesis pathway. Interestingly, significant changes in mRNA levels for both HIF-1α and p53 were apparent and gene regulation patterns were observed to switch from a HIF-1α-dependent to a p53-dependent process. Moreover, pre-treatment with pifithrin-α, a p53 inhibitor, inhibited protein synthesis almost completely, revealing the possibility of preventing fetal brain damage by prophylactic pifithrin-α treatment.

Effects of Antenatal Steroid Therapy on Neurodevelopment in an IUGR Mouse Model

Background/Objective: To investigate the neurodevelopmental response in postnatal mice secondary to antenatal steroid treatment in association with maternal protein restriction. Methods: C57BL/6N pregnant mice (n = 24; 4 per treatment group) were administered control (C) or protein-restricted (PR) diets and subjected to daily subcutaneous injection stress during late gestation (E10–E17) with either 100 µl/kg of dexamethasone sodium phosphate in normosaline (C-D/S, PR-D/S) or normosaline alone (C-S, PR-S). Non-treatment groups were also included (C, PR). Brain samples of pups were collected on postnatal day 7 and analyzed by immunohistochemistry and qRT-PCR. Results: Neonatal weights in the treatment groups were smaller than their counterparts in the C group, but there were no significant differences in brain size. Immunohistochemical evaluation of neuroglial cells revealed a pronounced effect of protein restriction on oligodendrocytes and oligodendrocyte precursor cells with distinct fetal responses to stress and dexamethasone. Further evaluation using quantitative RNA analysis showed significant activation of Galr1, Galr2, Igfbp-1, Igfbp-3, Igfbp-6, and Fgf2 by 1- to 2.5-fold in the PR-D/S group and by much higher increments, 1- to 10.5-fold, in the PR-S group. Conclusion: This preliminary investigation revealed the possible role of dexamethasone in further increasing vulnerability to cell damage in injury-prone neuroglial cells. The distribution of key glial markers and the overexpression of several neurotrophic factors depicted ongoing cellular adaptation.

Vaginal LPS changed gene transcriptional regulation response to ischemic reperfusion and increased vulnerability of fetal brain hemorrhage

During pregnancy, both ischemic reperfusion and bacterial agent LPS are known risk factors for fetal brain damage. However, there is a lack of evidence to explain whether vaginal LPS affects the fetus response to ischemic reperfusion. Here we reported that there was more than 2 folds higher vulnerability of fetal brain hemorrhage response to ischemic reperfusion when mother mouse was treated with vaginal LPS. As our previously reported, ischemic reperfusion induces P53-dependent fetal brain damage was based on a molecular mechanism: the transcriptional pattern was changed from HIF-1alpha-dependent to P53-dependent immediately. In the present work, only with vaginal LPS precondition, phosphorylation of activated transcriptional factor (ATF) 2 at Thr71 appeared in response to ischemic reperfusion. Moreover, this phosphorylation was completely blocked by pre-treatment with a P53 inhibitor, pifithrin-α. We concluded that vaginal LPS precondition trigged the p53-dependent phosphorylation of ATF2 in response to ischemic reperfusion, which played an important role of increasing vulnerability to hemorrhage in fetus.

Molecular patterns of neurodevelopmental preconditioning: a study of the effects of antenatal steroid therapy in a protein-restriction mouse model.

Introduction. Prenatal programming secondary to maternal protein restriction renders an inherent susceptibility to neural compromise in neonates and any addition of glucocorticosteroids results in further damage. This is an investigation of consequent global gene activity due to effects of antenatal steroid therapy on a protein restriction mouse model. Methods. C57BL/6N pregnant mice were administered control or protein restricted diets and subjected to either 100 μg/Kg of dexamethasone sodium phosphate with normosaline or normosaline alone during late gestation (E10–E17). Nontreatment groups were also included. Brain samples were collected on embryonic day 17 and analyzed by mRNA microarray analysis. Results. Microarray analyses presented 332 significantly regulated genes. Overall, neurodevelopmental genes were overrepresented and a subset of 8 genes allowed treatment segregation through the hierarchical clustering method. The addition of stress or steroids greatly affected gene regulation through glucocorticoid receptor and stress signaling pathways. Furthermore, differences between dexamethasone-administered treatments implied a harmful effect during conditions of high stress. Microarray analysis was validated using qPCR. Conclusion. The effects of antenatal steroid therapy vary in fetuses according to maternal-fetal factors and environmental stimuli. Defining the key regulatory networks that signal either beneficial or damaging corticosteroid action would result in valuable adjustments to current treatment protocols.

Ultrasound Imaging of Mouse Fetal Intracranial Hemorrhage Due to Ischemia/Reperfusion

Despite vast improvement in perinatal care during the 30 years, the incidence rate of neonatal encephalopathy remains unchanged without any further Progress towards preventive strategies for the clinical impasse. Antenatal brain injury including fetal intracranial hemorrhage caused by ischemia/reperfusion is known as one of the primary triggers of neonatal injury. However, the mechanisms of antenatal brain injury are poorly understood unless better predictive models of the disease are developed. Here we show a mouse model for fetal intracranial hemorrhage in vivo developed to investigate the actual timing of hypoxia-ischemic events and their related mechanisms of injury. Intrauterine growth restriction mouse fetuses were exposed to ischemia/reperfusion cycles by occluding and opening the uterine and ovarian arteries in the mother. The presence and timing of fetal intracranial hemorrhage caused by the ischemia/reperfusion were measured with histological observation and ultrasound imaging. Protein-restricted diet increased the risk of fetal intracranial hemorrhage. The monitoring of fetal brains by ultrasound B-mode imaging clarified that cerebral hemorrhage in the fetal brain occurred after the second ischemic period. Three-dimensional ultrasound power Doppler imaging visualized the disappearance of main blood flows in the fetal brain. These indicate a breakdown of cerebrovascular autoregulation which causes the fetal intracranial hemorrhage. This study supports the fact that the ischemia/reperfusion triggers cerebral hemorrhage in the fetal brain. The present method enables us to noninvasively create the cerebral hemorrhage in a fetus without directly touching the body but with repeated occlusion and opening of the uterine and ovarian arteries in the mother.

Evaluation of Abdominal Fetal Electrocardiography in Early Intrauterine Growth Restriction

Objectives: This descriptive study was performed to evaluate the capability of a non-invasive transabdominal electrocardiographic system to extract clear fetal electrocardiographic (FECG) measurements from intrauterine growth restricted (IUGR) fetuses and to assess whether abdominal FECG parameters can be developed as markers for evaluating the fetal cardiac status in IUGR. Methods: Transabdominal FECG was attempted in 20 controls and 15 IUGR singleton pregnancies at 20+0−33+6 weeks gestation. Standard ECG parameters were compared between the study groups and evaluated for their correlation. Accuracy for the prediction of IUGR by cut off values of the different FECG parameters was also determined. Results: Clear P-QRST complexes were recognized in all cases. In the IUGR fetuses, the QT and QTc intervals were significantly prolonged (p = 0.017 and p = 0.002, respectively). There was no correlation between ECG parameters and Doppler or other indices to predict IUGR. The generation of cut off values for detecting IUGR showed increasing sensitivities but decreasing specificities with the prolongation of ECG parameters. Conclusion: The study of fetal electrocardiophysiology is now feasible through a non-invasive transabdominal route. This study confirms the potential of FECG as a clinical screening tool to aid diagnosis and management of fetuses after key limitations are addressed. In the case of IUGR, both QT and QTc intervals were significantly prolonged and thus validate earlier study findings where both these parameters were found to be markers of diastolic dysfunction. This research is a useful prelude to a test of accuracy and Receiver Operating Characteristics (ROC) study.