Gut lumen formation defect can cause intestinal atresia: evidence from histological studies of human embryos and intestinal atresia septum.

Intestinal atresia (IA), a common cause of neonatal intestinal obstruction, is a developmental defect, which disrupts the luminal continuity of the intestine. Here, we investigated (i) the process of lumen formation in human embryos; and (ii) how a defective lumen formation led to IA. We performed histological and histochemical study on 6-10 gestation week human embryos and on IA septal regions. To investigate the topology of embryonic intestine development, we conducted 3D reconstruction. We showed that a 6-7th gestation week embryonic gut has no lumen, but filled with mesenchyme cells and vacuoles of a monolayer of epithelial cells. A narrow gut lumen was formed by gestation week-9, the gut was filled with numerous vacuoles of different sizes, some vacuoles were merging with the developing embryonic gut wall. At gestation week-10, a prominent lumen was developed, only few vacuoles were present and were merging with the intestine wall. At IA septal regions, vacuoles were located in the submucous layer, covered by a single layer of epithelium without glandular structure, and surrounded with fibrous tissue. The mucosal epithelium was developed with lamina propria and basement membrane, but the submucosa and the longitudinal smooth muscle layers were not properly developed. Hence, the vacuoles in IA septum could represent a remnant of vacuoles of embryonic gut. In conclusion, the fusion of vacuoles with the developing intestine wall associates with the disappearance of vacuoles and gut lumen formation in human embryos, and perturbation of these developmental events could lead to IA.

Does COVID-19 infection influence patients' performance during IVF-ET cycle?: an observational study.

OBJECTIVE: No information exists in the literature regarding the effect of coronavirus disease 19 (COVID-19) infection on subsequent in vitro fertilization (IVF) cycle attempt. We, therefore, aim to assess the influence of COVID-19 infection on IVF treatments. DESIGN: An observational study. SETTING: A tertiary, university-affiliated medical center. PATIENTS AND METHODS: All consecutive couples undergoing ovarian stimulation (OS) for IVF, before and after recovering from COVID-19 infection, and reached the ovum pick-up (OPU) stage. The stimulation characteristics and embryological variables of couples undergoing IVF treatments after recovering from COVID-19 infection were assessed and compared to their IVF cycles prior to COVID-19 infection. MAIN OUTCOME MEASURES: Stimulation characteristics and embryological variables. RESULTS: Nine couples (seven with the female partner infection and two with the male partner) resumed IVF treatment 8-92 d after recovering from the COVID-19 infection (negative polymerase chain reaction [PCR]). No in-between cycles differences were observed in OS and embryological variables between the cycles before and after recovering from the COVID-19 infection, except for a significantly lower proportion of top-quality embryos. CONCLUSIONS: COVID-19 infection did not affect patients' performance or ovarian reserve in their immediate subsequent IVF cycle, except for a reduced proportion of top-quality embryos (TQEs). We therefore suggest, to postpone IVF treatment for a least 3 months (duration of folliculogenesis and spermatogenesis) after recovering from COVID-19 infection, aiming to recruit healthy gametes that were not exposed to COVID-19 infection during their development.

Endometrial causes of recurrent pregnancy losses: endometriosis, adenomyosis, and chronic endometritis.

Chronic inflammatory processes affecting the endometrium, as encountered in endometriosis, adenomyosis, and chronic endometritis, alter endometrial receptivity. These disorders are associated with early pregnancy losses and possibly recurrent pregnancy losses (RPL). In the cases of endometriosis, other factors associated with the disease also are susceptible of causing miscarriages and possibly RPL, such as an impact of intrapelvic inflammatory processes affecting the oocyte and embryo in case of natural conception. Conversely these latter effects obviously are bypassed in case of assisted reproductive technology. Chronic inflammation of the endometrium in the condition known as chronic endometritis also causes early pregnancy losses and RPL with beneficial effects achieved when specific treatment is undertaken.

Heat shock protein 60 regulates yolk sac erythropoiesis in mice.

The yolk sac is the first site of blood-cell production during embryonic development in both murine and human. Heat shock proteins (HSPs), including HSP70 and HSP27, have been shown to play regulatory roles during erythropoiesis. However, it remains unknown whether HSP60, a molecular chaperone that resides mainly in mitochondria, could also regulate early erythropoiesis. In this study, we used Tie2-Cre to deactivate the Hspd1 gene in both hematopoietic and vascular endothelial cells, and found that Tie2-Cre+Hspd1f/f (HSP60CKO) mice were embryonic lethal between the embryonic day 10.5 (E10.5) and E11.5, exhibiting growth retardation, anemia, and vascular defects. Of these, anemia was observed first, independently of vascular and growth phenotypes. Reduced numbers of erythrocytes, as well as an increase in cell apoptosis, were found in the HSP60CKO yolk sac as early as E9.0, indicating that deletion of HSP60 led to abnormality in yolk sac erythropoiesis. Deletion of HSP60 was also able to reduce mitochondrial membrane potential and the expression of the voltage-dependent anion channel (VDAC) in yolk sac erythrocytes. Furthermore, cyclosporine A (CsA), which is a well-recognized modulator in regulating the opening of the mitochondrial permeability transition pore (mPTP) by interacting with Cyclophilin D (CypD), could significantly decrease cell apoptosis and partially restore VDAC expression in mutant yolk sac erythrocytes. Taken together, we demonstrated an essential role of HSP60 in regulating yolk sac cell survival partially via a mPTP-dependent mechanism.

Altered morphokinetics in equine embryos from oocytes exposed to DEHP during IVM.

Di-(2-ethylhexyl) phthalate (DEHP) is a commonly used plasticizer with endocrine-disrupting properties. In this study, we used an equine model to investigate DEHP concentrations in ovarian follicular fluid (FF), and to determine the effects of exposure of oocytes to potentially toxic concentrations of DEHP during in vitro maturation (IVM) on embryo development and quality. Embryo development was evaluated using time-lapse monitoring (TLM), a photomicroscopic tool that reveals abnormalities in cleavage kinetics unobservable by conventional morphology assessment. Blastocyst bioenergetic/oxidative status was assessed by confocal analysis. The possibility that verbascoside (VB), a bioactive polyphenol with antioxidant activity, could counteract DEHP-induced oocyte oxidative damage, was investigated. DEHP was detected in FF and in IVM media at concentrations up to 60 nM. Culture of oocytes in the presence of 500 nM DEHP delayed second polar body extrusion, reduced duration of the second cell cycle, and increased the percentage of embryos showing abrupt multiple cleavage, compared with controls. Mitochondrial activity and intracellular levels of reactive oxygen species were reduced in blastocysts from DEHP-exposed oocytes. VB addition during IVM limited DEHP-induced blastocyst damage. In conclusion, DEHP is detectable in equine FF and culture medium, and oocyte exposure to increased concentrations of DEHP during IVM affects preimplantation embryo development. Moreover, TLM, reported for the first time in the horse in this study, is an efficient tool for identifying altered morphokinetic parameters and cleavage abnormalities associated with exposure to toxic compounds.

Exploring fetal response to acidosis in ewes: Choosing an adequate experimental model.

INTRODUCTION: Knowledge of fetal physiology during labor has been largely generated from animal models. Our team recently developed a new index to assess parasympathetic activity using different experimental protocols to obtain acidosis. The objective of the present study was to discuss the different protocols and to review other models proposed in the literature. MATERIAL AND METHODS: Pregnant ewes underwent a surgical procedure at the 123±2 days gestational age (term=145 days). Three experimental protocols were used: protocol A consisted of 25%, 50% and 75% umbilical cord occlusion (UCO) for 20min. Protocol B consisted of partial 75% UCO until reaching a pH<7.10. Protocol C consisted of brief, repetitive complete occlusion until severe acidosis occurred. Hemodynamic and blood gas parameters were compared to those of the stability period before UCO. RESULTS: Protocol A led to a progressive response depending on the degree of occlusion (decrease in fetal heart rate, arterial hypertension and pH). Protocol B led to severe acidosis, although the duration of UCO varied per animal. Protocol C also progressively led to acidosis. We observed high inter individual variability in the acidosis response. CONCLUSION: Pregnant ewes are a relevant model for exploring fetal response to acidosis. The frequency of UCO and partial or complete occlusion should be adapted to the expected effects. Knowledge of these protocols is important to respect ethical guidelines and to reduce the required number of animals. Moreover, it is important to consider the high individual variability of the acidosis response in the interpretation of the results.

Bisphenol A in Reproduction: Epigenetic Effects.

BACKGROUND: Bisphenol A (BPA) is an endocrine disrupting chemical widely used in the manufacture of polycarbonate plastic and epoxy resin to produce a multitude of consumer products, food and drink containers, and medical devices. BPA is similar to estradiol in structure and thus interferes in steroid signalling with different outcomes on reproductive health depending on doses, life stage, mode, and timing of exposure. In this respect, it has an emerging and controversial role as a "reproductive toxicant" capable of inducing short and long-term effects including the modulation of gene expression through epigenetic modification (i.e. methylation of CpG islands, histone modifications and production of non-coding RNA) with direct and trans-generational effects on exposed organisms and their offspring, respectively. OBJECTIVE: This review provides an overview about BPA effects on reproductive health and aims to summarize the epigenetic effects of BPA in male and female reproduction. RESULTS: BPA exerts epigenetic effects in both male and female reproduction. In males, BPA affects spermatogenesis and sperm quality and possible trans-generational effects on the reproductive ability of the offspring. In females, BPA affects ovary, embryo development, and gamete quality for successful in vivo and in vitro fertilization (IVF). CONCLUSION: The exact mechanisms of BPA-mediated effects in reproduction are not fully understood; however, the environmental exposure to BPA - especially in fetal and neonatal period - deserves attention to preserve the reproductive ability in both sexes and to reduce the epigenetic risk for the offspring.

Blechschmidt Collection: Revisiting specimens from a historical collection of serially sectioned human embryos and fetuses using modern imaging techniques.

Along with the Carnegie Collection in the United States and the Kyoto Collection in Japan, the Blechschmidt Collection (Georg-August-University of Göttingen, Germany) is a major historical human embryo and fetus collection. These collections are of enormous value to human embryology; however, due to the nature of the historical histological specimens, some stains are fading in color, and some glass slides are deteriorating over time. To protect these specimens against such degradation and ensure their future usefulness, we tried to apply modern image scanning and computational reconstruction. Samples of histological specimens of the Blechschmidt Collection were digitized into images using commercial flatbed scanners with a resolution of 4800 pixels per inch. Two specimens were reconstructed into three-dimensional (3D) images by using modern techniques to vertically stack two-dimensional images of the slices into 3D blocks. The larger specimen of crown-rump length (CRL) 64.0 mm, a series of very large histological sections in human embryology, was reconstructed clearly, with its central nervous system segmented before stacking. The smaller specimen of CRL 17.5 mm was also reconstructed into 3D images. The outer surface of the embryo was intact, and its development was classified according to the widely used Carnegie stages (CSs). The CS of the specimen was identified as the later half of CS 20. The invaluable Blechschmidt Collection can be revisited for further research with modern techniques such as digital image scanning and computational 3D reconstruction.

Polar body transfer restores the developmental potential of oocytes to blastocyst stage in a case of repeated embryo fragmentation.

PURPOSE: We aimed to determine the developmental potential of human reconstructed oocytes after polar body genome transfer (PBT) and to report the case of a woman with multiple cycles of severe embryo fragmentation. METHODS: Fresh and cryopreserved first polar bodies (PB1s) were transferred to enucleated metaphase II oocytes (PB1T), while fresh PB2s were removed from fertilized oocytes and used instead of the female pronucleus in donor zygotes. Reconstructed oocytes underwent intracytoplasmic sperm injection (ICSI) and were cultured to blastocyst. Biopsied trophectoderm cells of PBT-derived blastocysts were screened for chromosomes by next-generation sequencing (NGS). Then, cryopreserved PB1T was carried out in one woman with a history of several cycles of extensive embryo fragmentation, and the blastocysts derived from PB1T were screened for aneuploidy but not transferred to the patient. RESULTS: There were no significant differences in the rates of normal fertilization and blastocyst formation between fresh and cryopreserved PB1T and control oocytes. Of the three fresh and three cryopreserved PB1T-derived blastocysts, two and one blastocysts exhibited normal diploidy respectively. In contrast, 17 PB2 transfers yielded 16 two pronuclei (2PN) zygotes with one normal and one small-sized pronucleus each and no blastocyst formation. In the female patient, 18 oocytes were inseminated by ICSI in the fourth cycle and the PB1s were biopsied. Although the embryos developed from the patient's own oocytes showed severe fragmentation, the oocytes reconstructed after PB1T produced three chromosomally normal blastocysts. CONCLUSIONS: Normal blastocysts can develop from human reconstructed oocytes after PB1T. The application of the first PB transfers may be beneficial to patients with a history of poor embryo development and excessive fragmentation.

Biphasic effect of alpha-linolenic acid on glucose-induced dysmorphogenesis and lipoperoxidation in whole rat embryo in culture.

Type 1 diabetes mellitus complicated with pregnancy, know as diabetic embryopathy, is the cause of neonatal malformations and low for gestational age neonates. With the use of the whole-embryo culture system, it has been demonstrated that high glucose causes embryo dysmorphogenesis, and that oxidative stress appears to be the main mechanism. In recent years, beneficial effect of omega-3 fatty acids has been demonstrated in various diabetic models, and in diabetic complications. Since diabetic embryopathy is mediated probably through membrane lipoperoxidation, This study was designed to find if omega-3 fatty acids could ameliorate the effect of high glucose over the dysmorphogenesis of whole rat embryo in culture. Postimplantational rat embryos were cultured in hyperglycemic media, with addition of alpha-linolenic acid, and morphologic and morphometric parameters were registered. Also, lipoperoxidation and fatty acids composition were measured in cultured embryos. Growth of embryos cultured in presence of glucose was very affected, whereas lipoperoxidation was increased, and it was found that Triton X-100 causes similar results than glucose. Addition of low micromolar doses of alpha-linolenic acid overcome the effect of high glucose or Triton X-100, but higher doses does not ameliorates the effects of the carbohydrate or the detergent. Paradoxically, there are not significant changes in fatty acids composition, although the U/S fatty acids ratio shows an increasing tendency by high glucose and a normalizing tendency by omega-3 fatty acids. In conclusion, glucose and Triton X-100 induces in vitro dysmorphogenesis in post-implantational rat embryos associated with increased lipoperoxidation; and this nocive effect could be ameliorated by low micromolar doses of ALA.

Muscle developmental defects in heterogeneous nuclear Ribonucleoprotein A1 knockout mice.

Heterogeneous ribonucleoprotein A1 (hnRNP A1) is crucial for regulating alternative splicing. Its integrated function within an organism has not, however, been identified. We generated hnRNP A1 knockout mice to study the role of hnRNP A1 in vivo The knockout mice, hnRNP A1-/-, showed embryonic lethality because of muscle developmental defects. The blood pressure and heart rate of the heterozygous mice were higher than those of the wild-type mice, indicating heart function defects. We performed mouse exon arrays to study the muscle development mechanism. The processes regulated by hnRNP A1 included cell adhesion and muscle contraction. The expression levels of muscle development-related genes in hnRNP A1+/- mice were significantly different from those in wild-type mice, as detected using qRT-PCR. We further confirmed the alternative splicing patterns of muscle development-related genes including mef2c, lrrfip1, usp28 and abcc9 Alternative mRNA isoforms of these genes were increased in hnRNP A1+/- mice compared with wild-type mice. Furthermore, we revealed that the functionally similar hnRNP A2/B1 did not compensate for the expression of hnRNP A1 in organisms. In summary, our study demonstrated that hnRNP A1 plays a critical and irreplaceable role in embryonic muscle development by regulating the expression and alternative splicing of muscle-related genes.

Galnt1 is required for normal heart valve development and cardiac function.

Congenital heart valve defects in humans occur in approximately 2% of live births and are a major source of compromised cardiac function. In this study we demonstrate that normal heart valve development and cardiac function are dependent upon Galnt1, the gene that encodes a member of the family of glycosyltransferases (GalNAc-Ts) responsible for the initiation of mucin-type O-glycosylation. In the adult mouse, compromised cardiac function that mimics human congenital heart disease, including aortic and pulmonary valve stenosis and regurgitation; altered ejection fraction; and cardiac dilation, was observed in Galnt1 null animals. The underlying phenotype is aberrant valve formation caused by increased cell proliferation within the outflow tract cushion of developing hearts, which is first detected at developmental stage E11.5. Developing valves from Galnt1 deficient animals displayed reduced levels of the proteases ADAMTS1 and ADAMTS5, decreased cleavage of the proteoglycan versican and increased levels of other extracellular matrix proteins. We also observed increased BMP and MAPK signaling. Taken together, the ablation of Galnt1 appears to disrupt the formation/remodeling of the extracellular matrix and alters conserved signaling pathways that regulate cell proliferation. Our study provides insight into the role of this conserved protein modification in cardiac valve development and may represent a new model for idiopathic valve disease.

Chronic intrauterine pulmonary hypertension increases main pulmonary artery stiffness and adventitial remodeling in fetal sheep.

Persistent pulmonary hypertension of the newborn (PPHN) is a clinical syndrome that is characterized by high pulmonary vascular resistance due to changes in lung vascular growth, structure, and tone. PPHN has been primarily considered as a disease of the small pulmonary arteries (PA), but proximal vascular stiffness has been shown to be an important predictor of morbidity and mortality in other diseases associated with pulmonary hypertension (PH). The objective of this study is to characterize main PA (MPA) stiffness in experimental PPHN and to determine the relationship of altered biomechanics of the MPA with changes in extracellular matrix (ECM) content and orientation of collagen and elastin fibers. MPAs were isolated from control and PPHN fetal sheep model and were tested by planar biaxial testing to measure stiffness in circumferential and axial vessel orientations. Test specimens were fixed for histological assessments of the vascular wall ECM constituents collagen and elastin. MPAs from PPHN sheep had increased mechanical stiffness (P < 0.05) and altered ECM remodeling compared with control MPA. A constitutive mathematical model and histology demonstrated that PPHN vessels have a smaller contribution of elastin and a greater role for collagen fiber engagement compared with the control arteries. We conclude that exposure to chronic hemodynamic stress in late-gestation fetal sheep increases proximal PA stiffness and alters ECM remodeling. We speculate that proximal PA stiffness further contributes to increased right ventricular impedance in experimental PPHN, which contributes to abnormal transition of the pulmonary circulation at birth.

Superoxide dismutase 1 overexpression in mice abolishes maternal diabetes-induced endoplasmic reticulum stress in diabetic embryopathy.

OBJECTIVE: Both oxidative stress and endoplasmic reticulum stress (ER stress) are causal events in diabetic embryopathy. We tested whether oxidative stress causes ER stress. STUDY DESIGN: Wild-type (WT) and superoxide dismutase 1 (SOD1)-overexpressing day 8.75 embryos from nondiabetic WT control with SOD1 transgenic male and diabetic WT female with SOD1 transgenic male were analyzed for ER stress markers: C/EBP-homologous protein (CHOP), calnexin, eukaryotic initiation factor 2α (eIF2α), protein kinase ribonucleic acid (RNA)-like ER kinase (PERK), binding immunoglobulin protein, protein disulfide isomerase family A member 3, kinases inositol-requiring protein-1α (IRE1α), and the X-box binding protein (XBP1) messenger RNA (mRNA) splicing. RESULTS: Maternal diabetes significantly increased the levels of CHOP, calnexin, phosphorylated (p)-eIF2α, p-PERK, and p-IRE1α; triggered XBP1 mRNA splicing; and enhanced ER chaperone gene expression in WT embryos. SOD1 overexpression blocked these diabetes-induced ER stress markers. CONCLUSION: Mitigating oxidative stress via SOD1 overexpression blocks maternal diabetes-induced ER stress in vivo.

From conception to birth - how endometriosis affects the development of each stage of reproductive life.

Increasing evidence suggests that female infertility is associated with endometriosis. Indeed, 40% of women with this disease are infertile. However, a causal relationship has not yet been established, and the possible pathophysiology of infertility in this disease also has not been completely elucidated. In this article, we analyze the mechanisms necessary to achieve a successful live birth in patients with this disease as well as the important steps of fertility, pregnancy and birth that can be impaired in these women. Specifically, we will review new advances in research on folliculogenesis, oocyte quality and sperm quality, egg fertilization, embryo quality, transport through fallopian tube and utero-tubal transport sperm, implantation defects, risk of miscarriage, risk during pregnancy and pre-term delivery. The physiopathology of these alterations and the clinical results of the studies are still very controversial. For these reasons, we can conclude that more research is needed to study the biological pathways of the fertility impairment caused by this disease.

Krüppel-like factor 2 is required for normal mouse cardiac development.

Krüppel-like factor 2 (KLF2) is expressed in endothelial cells in the developing heart, particularly in areas of high shear stress, such as the atrioventricular (AV) canal. KLF2 ablation leads to myocardial thinning, high output cardiac failure and death by mouse embryonic day 14.5 (E14.5) in a mixed genetic background. This work identifies an earlier and more fundamental role for KLF2 in mouse cardiac development in FVB/N mice. FVB/N KLF2-/- embryos die earlier, by E11.5. E9.5 FVB/N KLF2-/- hearts have multiple, disorganized cell layers lining the AV cushions, the primordia of the AV valves, rather than the normal single layer. By E10.5, traditional and endothelial-specific FVB/N KLF2-/- AV cushions are hypocellular, suggesting that the cells accumulating at the AV canal have a defect in endothelial to mesenchymal transformation (EMT). E10.5 FVB/N KLF2-/- hearts have reduced glycosaminoglycans in the cardiac jelly, correlating with the reduced EMT. However, the number of mesenchymal cells migrating from FVB/N KLF2-/- AV explants into a collagen matrix is reduced considerably compared to wild-type, suggesting that the EMT defect is not due solely to abnormal cardiac jelly. Echocardiography of E10.5 FVB/N KLF2-/- embryos indicates that they have abnormal heart function compared to wild-type. E10.5 C57BL/6 KLF2-/- hearts have largely normal AV cushions. However, E10.5 FVB/N and C57BL/6 KLF2-/- embryos have a delay in the formation of the atrial septum that is not observed in a defined mixed background. KLF2 ablation results in reduced Sox9, UDP-glucose dehydrogenase (Ugdh), Gata4 and Tbx5 mRNA in FVB/N AV canals. KLF2 binds to the Gata4, Tbx5 and Ugdh promoters in chromatin immunoprecipitation assays, indicating that KLF2 could directly regulate these genes. In conclusion, KLF2-/- heart phenotypes are genetic background-dependent. KLF2 plays a role in EMT through its regulation of important cardiovascular genes.

[Effects of repeated short-term immobilization stress on plastisity of brain cortical division and cognition in adult rats with normal and disturbed embryogenesis].

The aim of the work was the analysis of the changes in a number of labile synaptopodin-positi- ve dendritic spines in parietal cortex and the CA1 field of the hippocampus, which characterize plasticity of intracellular interaction, and of the memorization after short-term repeated immobili- zation stress (daily for 5 minutes, 10 days), both in control rats and in rats subjected to prenatal hypoxia (E14, 7% of O2, 3 hours). There were observed deterioration of short-term and long-term memory, decrease in number labile spines in the CA1 field of the hippocampus (for 17.3 ± 10.4%; p ≤ 0.05) and their increase in a molecular layer of brain parietal cortex (for 36.9 ± 9.2%) at the adult rats with normal embryogenesis after immobilization stress in comparison with control intact animals. At the rats subjected to a prenatal hypoxia, regardless of that, they were ex- posed to an immobilized stress at an adult stage or not, was noted both violation of short-term and long-term memory, and decrease in number labile spines in the CA1 field of the hippocampus (for 22.9 ± 10.5%) and parietal cortex (for 28.1 ± 9.3%). The obtained data allow to conclude that the increase of plasticity providing adaptive behavior of animals, takes place in neocortical neuronal networks as a reply to a short-term repeating stress only at normal brain formation during embryo- genesis, while, violation of embryogenesis leads to decrease in plasticity and adaptive opportuni- ties of the nervous system during further ontogenesis.

Cryopreservation of embryos by vitrification at a private sector reproductive medicine facility in Karachi.

OBJECTIVE: To assess the survival of freezing cleaved human embryos through vitrification. METHODS: The prospective study was conducted at the Karachi-based Sindh Institute of Reproductive Medicine between June 2008 and June 2009. The cryopreservation of embryos being a new technology in Pakistan, only 19 couples, picked through convenience sampling, comprised the study population. The couples were treated for infertility by in virto fertilisation (IVF) or intracytoplasmic sperm injection (ICSI); 125 surplus embryos were vitrified. Subsequently, 15 embryos were thawed, and transferred in a controlled cycle. SPSS version 11 was used for statistical analysis. RESULT: After the surplus embryos were vitrified and subsequently thawed and transferred, the survival of the embryos was assessed by the number of blastomeres that were intact. The overall embryo survival rate was (14/15) 93.33%. CONCLUSION: Vitrification is a simple procedure that requires less time and is likely to become safer and more cost-effective with time. Survival rate after thawing and preserving is high, but comparative success rates in terms of pregnancy and taking-home-baby rates are yet to be established in Pakistan.

Antipsychotic drugs cause bradycardia in GD 13 rat embryos in vitro.

This study investigated the effects of antipsychotic drugs on heart function of gestational day (GD) 13 rat embryos in vitro since they all block the I(Kr)/hERG potassium ion channel in addition to their main pharmacological effect on neurotransmitters. The results showed that all the tested antipsychotic drugs caused bradycardia of the rat embryonic heart in a concentration-dependent manner. However, with the possible exception of haloperidol the tested drugs did not cause arrhythmias typically seen with the highly selective I(Kr)/hERG blocking drug dofetilide. For six of the eight drugs tested the effects on the embryonic rat heart were only seen at free drug concentrations that were much greater than those likely to occur in pregnant women taking antipsychotic medication. However, the safety margins for haloperidol and quetiapine were lower.

Adrenergic deficiency leads to impaired electrical conduction and increased arrhythmic potential in the embryonic mouse heart.

To determine if adrenergic hormones play a critical role in the functional development of the cardiac pacemaking and conduction system, we employed a mouse model where adrenergic hormone production was blocked due to targeted disruption of the dopamine ß-hydroxylase (Dbh) gene. Immunofluorescent histochemical evaluation of the major gap junction protein, connexin 43, revealed that its expression was substantially decreased in adrenergic-deficient (Dbh-/-) relative to adrenergic-competent (Dbh+/+ and Dbh+/-) mouse hearts at embryonic day 10.5 (E10.5), whereas pacemaker and structural protein staining appeared similar. To evaluate cardiac electrical conduction in these hearts, we cultured them on microelectrode arrays (8×8, 200 µm apart). Our results show a significant slowing of atrioventricular conduction in adrenergic-deficient hearts compared to controls (31.4±6.4 vs. 15.4±1.7 ms, respectively, p<0.05). To determine if the absence of adrenergic hormones affected heart rate and rhythm, mouse hearts from adrenergic-competent and deficient embryos were cultured ex vivo at E10.5, and heart rates were measured before and after challenge with the ß-adrenergic receptor agonist, isoproterenol (0.5 µM). On average, all hearts showed increased heart rate responses following isoproterenol challenge, but a significant (p<0.05) 225% increase in the arrhythmic index (AI) was observed only in adrenergic-deficient hearts. These results show that adrenergic hormones may influence heart development by stimulating connexin 43 expression, facilitating atrioventricular conduction, and helping to maintain cardiac rhythm during a critical phase of embryonic development.