Stages Of Fetal Development Research Articles

Teratogenicity of Monosodium Glutamate on The Pregnant Rats and Their Fetuses

Background: 2% to 3% of all living newborns showed at least one recognizable congenital malformation. Monosodium glutamate (MSG) is widely used as flavor enhancer. But, it induces embryonic and fetal toxicity in rats during the gestational periods. Aim of the work: this study aimed to detect the effects of MSG on placenta and fetal developmental stages at 15th and 19th days of gestation. Material and Methods: fifty mature pregnant Albino rats (Weight 200 ± 20 g) were categorized into two groups according to the time of dissection at 15thor 19th days of gestation. From each group, half of the pregnant mothers (G15 and G19)were daily administrated MSG ( 7 g/10mL/kg b. w. by oral)from the 9th to 14th days of gestation). The control groups (C15 and C 19) were received water only. Results: in G15 and G19 groups, the uterine and fetal shape, number of implantation sites, number of living fetuses, body length, fetal and placental weights and the placental co-efficient were negatively changed when compared to the control groups(C15 and C 19). Also, the placental tissue showed congested blood sinuses and large hemorrhagic areas which contained hemolysed blood cells. Some atrophied decidual cells and pyknotic nuclei were observed with highly distorted maternal and fetal placental layers. Conclusions: this study showed that shortterm MSG exposure caused several maternal and fetal changes. Therefore, MSG is considered as embryotoxic agent and the mothers must avoid administration of this substance during the gestation period

Long bone human anlage longitudinal and circumferential growth in the fetal period and comparison with the growth plate cartilage of the postnatal age.

The patterns of longitudinal and peripheral growth were analyzed in human autopod cartilage anlagen (fetal developmental stage 20th-22nd week) through morphometric assessment of chondrocyte parameter size, shape, alignment and orientation between peripheral and central sectors of the anlage transition zone defined by primary ossification center and the epiphyseal basis. The aim was to correlate the chondrocyte dynamics with the longitudinal and peripheral growth. A further comparison was carried out between the corresponding sectors of the postnatal (3-5 months old) growth plate cartilage documenting: (1) the different chondrocyte framework and the new peripheral mechanism; (2) the opposite direction of fetal periosteal ossification versus the Lacroix bone bark. Measurement of multiple parameters (% lac area, % total matrix area, total lac density and mean single lac area), which characterize the cartilage Anlage growth, suggested the following correlations with chondrocyte duplication rate: (a) slow duplication rate ≈ coupled, intralacunar chondrocytes (in central epiphysis); (b) repeated/frequent cell duplications ≈ clusters (in the basal epiphyseal layer); (c) clusters of chondrocytes before becoming hypertrophic were stacked up on the top of each other (both in the Anlage transition zone or in the columns of metaphyseal growth plate); (d) enhanced osteoclastic resorption of the Lacroix bone bark lower end, extended to the more external metaphyseal trabeculae counterbalancing the discrepancy between the epiphyseal and the diaphyseal circumferential growth.

Functional annotation of differentially expressed fetal cardiac microRNA targets: implication for microRNA-based cardiovascular therapeutics.

Gene expression pattern of a failing heart depicts remarkable similarity with developing fetal heart. Elucidating genetic as well as epigenetic mechanisms regulating the gene expression during cardiac development will improve our understanding of cardiovascular diseases. In the present study, we aimed to validate and characterize differentially expressed known microRNAs (miRNA) obtained from next generation sequencing data of two fetal cardiac developmental stages (days 4th and 14th) from chicken (G. gallus domesticus) using bioinformatic approaches. Potential mRNA targets of individual miRNA were identified and classified according to their biological, cellular, and molecular functions. Functional annotation of putative target genes was performed to predict their association with cardiovascular diseases. We identified a total of 19 differentially expressed miRNAs between 4th and 14th day sample from the data sets obtained by next generation sequencing. A total of nearly 1522 potential targets ranging from 15 to 270 for each miRNA were predicted out of which 1221 were unique, while 301 were overlapping. Gene ontology and KEGG analysis revealed that majority of these target genes regulate critical cellular and molecular processes including transcriptional regulation, protein transport, signal transduction, matrix remodeling, Ras signaling, MAPK signaling, and TGF-beta signaling pathways indicating the complex nature of microRNA-mediated gene regulation during cardiogenesis. We found a significant association between potential target genes and cardiovascular diseases validating a link between fetal cardiac miRNAs and regulation of cardiovascular disease-related genes. These important findings may lay a foundation for further understanding the regulatory mechanisms operative in gene re-programming in the failing heart.

Interactions between nutrients in the maternal diet and the implications for the long-term health of the offspring.

Nutritional science has traditionally used the reductionist approach to understand the roles of individual nutrients in growth and development. The macronutrient dense but micronutrient poor diets consumed by many in the Western world may not result in an overt deficiency; however, there may be situations where multiple mild deficiencies combine with excess energy to alter cellular metabolism. These interactions are especially important in pregnancy as changes in early development modify the risk of developing non-communicable diseases later in life. Nutrient interactions affect all stages of fetal development, influencing endocrine programming, organ development and the epigenetic programming of gene expression. The rapidly developing field of stem cell metabolism reveals new links between cellular metabolism and differentiation. This review will consider the interactions between nutrients in the maternal diet and their influence on fetal development, with particular reference to energy metabolism, amino acids and the vitamins in the B group.

A Prospective Cohort Study Examining the Associations of Maternal Arsenic Exposure With Fetal Loss and Neonatal Mortality.

Arsenic crosses the placenta, possibly increasing the risk of adverse reproductive outcomes. We aimed to examine the association between maternal arsenic exposure and fetal/neonatal survival using data from a prospective cohort study of 1,616 maternal-infant pairs recruited at a gestational age of ≤16 weeks in Bangladesh (2008-2011). Arsenic concentration in maternal drinking water was measured at enrollment. Extended Cox regression (both time-dependent coefficients and step functions) was used to estimate the time-varying association between maternal arsenic exposure and fetal/neonatal death (all mortality between enrollment and 1 month after birth). In a sensitivity analysis, we assessed gestational arsenic exposure using maternal urine samples taken at enrollment. We observed 203 fetal losses and 20 neonatal deaths. Higher arsenic exposure was associated with a slightly decreased mortality rate up to the middle of the second trimester, and then the mortality rate switched directions around 20 weeks' gestation. In the step function model, the hazard ratios for combined mortality (fetal loss and neonatal death) per unit increase in the natural log of drinking water arsenic concentration (μg/L) ranged from 1.35 (95% CI: 1.08, 1.69) in weeks 25-28 to 0.81 (95% CI: 0.65, 1.02) in weeks 9-12. This nonlinear association suggests that arsenic may exert survival pressure on developing fetuses, potentially contributing to survival bias, and may also indicate that arsenic toxicity differs by fetal developmental stage.

Development of urinary organs in domestic cat during the embryonic and fetal periods.

The embryonic origin of the urogenital system came from the intermediate mesoderm. Kidney development involves three successive renal systems with a fast chronological overlap: the pronephro, the mesonephro, and the metanephro. Due to the lack of specific knowledge about this system in cats the present work aimed to describe their urinary organs development, focusing on the structures seen in pronephro, mesonephro, and metanephro during the embryonic and fetal stages of development. The techniques used in this study were: light microscopy, immunohistochemistry, scanning electron microscopy, and transmission electron microscopy. For that, embryos and fetuses from 12 pregnant mixed-breed domestic cats in different gestational stages were used to describe the proposed organs. The pronephro is present at early stages of embryonary development in embryos from 15 to 19 days with the presence of pronephro's corpuscles, ducts and tubules. The mesonephro is found, in general, between days 17 and 37, and contains mesonephric ducts, mesonephric tubules, and glomeruli. The metanephro is seen since 21 days of pregnancy with the presence of glomeruli, proximal and distal contorted tubules and at day 37, the cortex-medullary region is already differentiated. The evaluation of these structures enhances the knowledge about embryology of the urinary system in cats, aiding a better anatomical understanding of the system in the specie allowing the correlation with other species.

Adiponectin regulates glycogen metabolism at the human fetal–maternal interface

Throughout the entire first trimester of pregnancy, fetal growth is sustained by endometrial secretions, i.e. histiotrophic nutrition. Endometrial stromal cells (EnSCs) accumulate and secrete a variety of nutritive molecules that are absorbed by trophoblastic cells and transmitted to the fetus. Glycogen appears to have a critical role in the early stages of fetal development, since infertile women have low endometrial glycogen levels. However, the molecular mechanisms underlying glycogen metabolism and trafficking at the fetal–maternal interface have not yet been characterized. Among the various factors acting at the fetal–maternal interface, we focused on adiponectin – an adipocyte-secreted cytokine involved in the control of carbohydrate and lipid homeostasis. Our results clearly demonstrated that adiponectin controls glycogen metabolism in EnSCs by (i) increasing glucose transporter 1 expression, (ii) inhibiting glucose catabolism via a decrease in lactate and ATP productions, (iii) increasing glycogen synthesis, (iv) promoting glycogen accumulation via phosphoinositide-3 kinase activation and (v) enhancing glycogen secretion. Furthermore, our results revealed that adiponectin significantly limits glycogen endocytosis by human villous trophoblasts. Lastly, we demonstrated that once glycogen has been endocytosed into placental cells, it is degraded into glucose molecules in lysosomes. Taken as a whole, the present results demonstrate that adiponectin exerts a dual role at the fetal–maternal interface by promoting glycogen synthesis in the endometrium and conversely reducing trophoblastic glycogen uptake. We conclude that adiponectin may be involved in feeding the conceptus during the first trimester of pregnancy by controlling glycogen metabolism in both the uterus and the placenta.

I068] Radiation effects on the embryo and fetus

The effects of in utero radiation should not be confused with heritable effects that can manifest by irradiating germ cells (oocytes or spermatocytes) before conception, causing chromosomal aberrations and/or mutations in the genes themselves. These (stochastic) genetic effects have been documented in animals and insects, but there is no epidemiological evidence of excess heritable disease in the offspring of humans irradiated before conception. The irradiation of somatic cells of the embryo/fetus can cause both tissue injuries and stochastic effects. Tissue injuries are dependent on the fetal stage of development and have been documented in irradiated cohorts of Hiroshima/Nagasaki atomic bomb survivors and residents around Chernobyl and the Mayak Plant/Techa River in the Southern Urals, as well as after medical radiation. According to the 2013 US National Council on Radiation Protection and Measurements Report 174, embryo lethality can occur in the pre-implantation period at doses above 100 mGy; malformations (such as microcephaly, micrognathia and cleft palate) may occur during organogenesis above 100 mGy, and severe mental retardation, in the weeks 8–25th post conception, with a dose threshold of 300 mGy. The most sensitive period is the 8–15th week, where a decrease of up to 30 IQ units has been observed. As for radiation-induced stochastic effects, although cancer has been observed for in utero irradiated cohorts from Hiroshima/Nagasaki and Southern Urals, the numbers are small; it is not known which are the most vulnerable gestation periods. However, the cancer life time risk seems lower than that following irradiation during childhood, which in turn is much higher than in adults. On a mechanistic basis, the 2015 International Commission on Radiological Protection Report 131, suggested that because of high competition between the irradiated and non-irradiated stem cells after low doses in utero, the injured stem cells are discarded before birth, thus yielding a low cancer risk. During childhood growth, stem cell competition is less stringent (higher risk) as the stem cell/niche units increase in number to cope with the increase in tissue volume, an unnecessary mechanism in adulthood (lower risk). The presentation will end showing typical fetal doses in medical radiation procedures.

Age-Related and Individual Anatomical Variation in Testicular Topography in Human Fetuses

At present, male infertility remains an urgent medical concern. From year to year, despite advances in methods of diagnosis and treatment, medicine encounters an increasing number of infertile couples with male infertility playing a leading role. Prerequisites for fertility disorders very frequently appear in childhood. Urologists consider cryptorchidism a leading cause of male infertility. The aim of our study was to establish the relationship between testicular descent to the scrotum and the age of the fetus. Material and methods. The study was conducted using 195 specimens of male fetuses aged 4–10 months with 81.0–375.0 mm parietalcoccygeal length (PCL) using the methods of macromicroscopic, conventional, and microslide preparation under control of binocular loupes and morphometry. Results. At the beginning of the fetal period of human ontogenesis (fetuses 81.0–135.0 mm PCL), the right and left testicles are mainly located above the corresponding deep inguinal ring and they are less often located in a region of the iliac fossae. An analysis of topographic and anatomical features of the male reproductive glands in 5-month-old fetuses (136.0–185.0 mm PCL) revealed that the testicles were located within the large pelvis, with the lower end of both the right and left testicles located above the entrance to the deep inguinal ring at a distance that equals the length of the pelvic part of the gubernaculum testis—3.2 ± 0.3 mm (right) and 2.8 ± 0.2 mm (left). In 11 fetuses aged 7 months (231.0–270.0 mm PCL), the lower ends of the testicles and their gubernaculum testis are immersed in the corresponding deep inguinal ring. In eight fetuses, the testicles were within the deep inguinal ring. A combination of many factors contributes to the final migration of a testicle through the inguinal canal into the scrotum (fetuses: 270.0 cm–290.0 mm PCL), including muscle contraction of the anterolateral abdominal wall, an increase in intra-abdominal pressure, contractile capacity of the gubernaculum testis of the testicle, the vaginal process of the peritoneum, and the neuro-muscular system. We believe that the gubernaculum testis is a particularly significant factor in testicular descent to the scrotum. The gubernaculum testis is maximally developed prior to migration of a testicle through the inguinal canal (eighth month of antenatal development), as evidenced by the prevalence of smooth muscle cells over connective tissue elements. An analysis of testicular topography in fetuses aged 9 months (311.0–345.0 mm PCL) revealed that testicles were located in the scrotum in nine fetuses, near the superficial inguinal ring in six fetuses, within the inguinal canal in four cases, and in the deep inguinal ring in one case. In fetuses aged 10 months (346.0–375.0 mm PCL), testicles were located in the scrotum in 13 cases and within the inguinal canal in seven cases. According to our research, the fusion of layers of the vaginal process of the peritoneum occurs in fetuses aged 9–10 months, resulting in the disappearance of the communication of its cavity with the peritoneum. A delay in the fusion of the peritoneal vaginal process layers at the end of the fetal period is an anatomic prerequisite for the occurrence of congenital inguinal-scrotal hernias. Conclusions. It has been found that the rate of testicular descent to the scrotum does not always coincide with the corresponding stage of fetal development. An accelerated development of the gubernaculum testis in fetuses aged 5–8 months is a major factor of heterochronic development of a testicle and subsequent testicular descent into the scrotum.

Air pollutants and early origins of respiratory diseases

Air pollution is a global health threat and causes millions of human deaths annually. The late onset of respiratory diseases in children and adults due to prenatal or perinatal exposure to air pollutants is emerging as a critical concern in human health. Pregnancy and fetal development stages are highly susceptible to environmental exposure and tend to develop a long-term impact in later life. In this review, we briefly glance at the direct impact of outdoor and indoor air pollutants on lung diseases and pregnancy disorders. We further focus on lung complications in later life with early exposure to air pollutants. Epidemiological evidence is provided to show the association of prenatal or perinatal exposure to air pollutants with various adverse birth outcomes, such as preterm birth, lower birth weight, and lung developmental defects, which further associate with respiratory diseases and reduced lung function in children and adults. Mechanistic evidence is also discussed to support that air pollutants impact various cellular and molecular targets at early life, which link to the pathogenesis and altered immune responses related to abnormal respiratory functions and lung diseases in later life.

Transcriptomic and methylomic analysis reveal the toxicological effect of 2,3,7,8-Tetrachlorodibenzodioxin on human embryonic stem cell

Cumulating epidemiological studies demonstrated that environmental exposure to endocrine disrupting chemicals (EDCs) during the early stages of fetal development is associated with the increase in disease susceptibility in later life. The fetal developmental plasticity is considered as a protective mechanism against an undesirable prenatal environment. Dioxin is one of the environmental contaminants and is considered a diabetogenic factor. Experimental animal and human epidemiological studies have revealed that dioxin exposure was associated with insulin resistance and altered beta cell function. But the effect of dioxin exposure in early stage of fetal development is still largely unknown. In this report, we used the human embryonic stem cell (hESC) line, VAL-3, as a model, together with Methyl-CpG Binding Domain (MBD) protein-enriched genome sequencing and transcriptome sequencing (RNA-seq), in order to determine the dynamic changes of the epigenetic landscape and transcriptional dysregulation in hESC upon dioxin exposure. The bioinformatics analyses including the Database for Annotation, Visualization and Integrated Discovery (DAVID) analysis and Ingenuity Pathway Analysis (IPA) highlighted the predisposed neural, hepatic, cardiac and metabolic toxicological effects of dioxin during the fetal development.

Application of Stem Cells to Infertility Treatment with Emphasis on Mesenchymal Stem Cells and Ovarian Stem Cells.

Stem cells are a population of undifferentiated cells that originated from embryonic and fetal stages of development. Stem cells possess the potency to produce cells that ultimately form different tissues and organs. They are considered as potential alternative novel therapeutic agents for patients suffering from infertility due to their unlimited source and high differentiation potency. There are several studies that have shown that different types of stem cells (mesenchymal stem cells, embryonic, endometrial, and ovarian stem cells) can be differentiated into both spermatozoa and oocytes in vitro, proving their potential clinical use in management and cure of infertility issues. Furthermore, mouse model studies have shown that ovarian stem cells, when cultured in vitro, can differentiate into a mature oocyte; however, there are still a lot of debates and complications attached to this concept. In addition, this is yet to be established using human ovarian stem cells, but, if established, would be a novel fertility preservation and treatment technique for women with infertility-related complications. This review gives comprehensive details of the available clinical application of stem cells in infertility treatment.

Characterization and expression analyses of somatolactin-α and -β genes in rare minnows (Gobiocypris rarus) following waterborne cadmium exposure.

Using reverse transcription-polymerase chain reaction (RT-PCR) and RACE (rapid amplification of cDNA ends), somatolactin-α (rmSLα) and -β (rmSLβ) were identified from the pituitary gland of rare minnows (Gobiocypris rarus). The full-length cDNAs of these two genes were 1288 and 801bp, encoding prepeptides of 250 and 228 amino acids residues, respectively. rmSLβ can be detected in the brain (including the pituitary), ovary, testis, and gill, while rmSLα was mainly expressed in the brain. On the other hand, rmSLα was expressed in all the fetal developmental stages; however, rmSLβ can just be detected in the stages since from 14h post-fertilization (hpf). After exposure to acute waterborne cadmium (Cd), rmSLα was distinctly upregulated in juvenile rare minnows at all detected time points, from 24 to 96h and 10days, while rmSLβ was significantly altered only in 96h or 10-day treatment groups. As for adults, acute Cd exposure caused alterations of both rmSLα and rmSLβ in the brain (containing the pituitary) at the 24h; subchronic waterborne Cd treatment led to upregulation of rmSLα, while decrease of mSLβ in the brain. Alteration of rmSL transcripts following waterborne Cd exposure further confirmed the endocrine disruption of this heavy metal. Besides, exposure to as low as 5μg/L Cd caused alteration of rmSLα, which suggested that rmSLα might be a potential biomarker for risk assessment of aquatic Cd.

Sex-Related Differences in Urethra Development in Human Embryos

Virtually no information on the chronology of prenatal development of the human urinary tract and the sex-related differences in the emergence of urinary tract topography during embryonic development is presently available. The aim of our work was to study sex-related differences in urethra development in human embryos and early fetuses. Forty-nine preparations of human embryos and early fetuses without external signs of anatomical abnormalities were studied in order to achieve the aim and fulfill the objectives of the study. Embryos and early fetuses were divided into six groups according to gestational age and parietococcygeal length. The complex of adequate methods of morphological research used in the study included preparation and microscopy of serial histological and anatomical sections of human embryos, including female and male urinary tracts, preparation of 3D-reconstruction models, and morphometry. The formation of prostatic urethra, a derivative of the urogenital sinus, was shown to occur at the beginning of the ninth week of embryogenesis, and the primordium of the internal sphincter of the urinary tract was formed at the end of the tenth week. Formation of the terminal part of spongy urethra took place during weeks 10–11 and involved funnel-like protrusion of the ectoderm from the top of the balanus towards the urethra lumen. The secondary ventral displacement of the urethral opening does not occur in female fetuses, and, therefore, only the prostatic urethra is a homolog of the female urinary tract. The pelvic part of the urogenital sinus was transformed into the prostatic urethra and the membranous urethra of the male at the end of the first stage of fetal development. Elongation of the genital tubercle (a penis primordium) and formation of the urethral ridge walls that involved the urogenital folds occurred at the same time.

Two Distinct Myeloid Subsets at the Term Human Fetal-Maternal Interface.

During pregnancy, immune cells infiltrate the placenta at different stages of fetal development. NK cells and macrophages are the most predominant cell types. These immune cells play pleiotropic roles, as they control spiral artery remodeling to ensure appropriate blood supply and maintain long-term tolerance to a true allograft; yet, they must be able to mount appropriate immune defenses to pathogens that may threaten the fetus. Whether the same cell type accomplishes all these tasks or if there are dedicated subsets remains controversial. Here, we identify and characterize two distinct subsets of myeloid cells that differ in their pro-inflammatory/regulatory capacity. While one subset predominantly produces the immune-modulating cytokine IL-10, the second subset has superior capacity to secrete pro-inflammatory mediators, such as IL-1β and IL-6. The putative regulatory myeloid cells also express high levels of inhibitory receptors and their ligands, including programmed cell death 1 (PD1) ligands. Importantly, a large fraction of CD8 and CD4 cells in normal term human placenta are PD1 positive, suggesting that the PD1/PD1 ligands axis might be critical to maintain tolerance during pregnancy.

Sex-specific lung functional changes in adult mice exposed only to second-hand smoke in utero

BackgroundAn increasing number of epidemiological and experimental studies have associated exposure to second-hand smoke (SHS) during pregnancy with adverse outcomes in newborns. As we have previously shown in mice, in utero exposure to SHS at critical stages of fetal development, results in altered lung responses and increased disease susceptibility upon re-exposure to irritants (SHS or ovalbumin) in adulthood. In this study, we asked whether the in utero SHS exposure alone is sufficient to alter lung structure and function in adult mice.MethodsPregnant BALB/c mice were exposed from days 6 to 19 of pregnancy to 10 mg/m3 of SHS or HEPA-filtered air. Male and female offspring (n = 13–15/group) were sacrificed at 15 weeks of age. We measured lung function with non-invasive and invasive methods, performed lung morphometric analysis on trichrome-stained lung tissue samples, and assessed lung gene expression via RNA sequencing and protein assays.ResultsIn utero SHS exposure significantly increased mean linear intercept and decreased the surface area per unit volume of the lungs in both males and females, indicating perturbation in alveolar developmental processes. Tidal volume, minute volume and inspiratory capacity were significantly decreased compared with the controls only in male mice exposed in utero to SHS, suggesting that males are more sensitive than females to an SHS insult during lung development. This also suggests that in our model, lung structure changes may be necessary but are not sufficient to impair lung function. SERPINA1A, the mouse ortholog of human α1-antitrypsin, deficiency of which is a known genetic risk factor for emphysema, was down-regulated at the protein level in the in utero SHS-exposed mice. Additionally, DNMT3A protein expression was dysregulated, indicating that DNA methylation occurred in the lungs.ConclusionsOur results indicate that in utero SHS exposure alone alters both lung function and structure well into adulthood (15 weeks) in male mice. Furthermore, lung function alterations in this model are sex-specific, with males being more susceptible to in utero SHS effects. Overall, our data suggest that in utero SHS exposure alone can predispose to adult lung diseases.

Features of content and balance of toxic trace elements in hair of mothers and their premature infants.

Background. Objective. The aim of the study was to investigate features of content and balance of toxic trace elements (Cr, Cd, Pb, Ni) in hair of mothers and their premature infants at different gestational ages. Methods. We have studied content of Cr, Cd, Pb, Ni in hair of 40 mothers and their newborns. The content of microelements was studied using atomic absorption spectrophotometer C-115 MI, equipped with a computer console for automatic calculation of trace elements production of HBO «Selmi» (Ukraine). Results. We have established average content and ratio of toxic elements (Cr, Cd, Pb, Ni) in hair of mothers and their premature infants at different gestational ages. Conclusions. It was established that the level of toxic trace elements were higher in the hair of women, compared to their newborn children. Indicators of chromium and nickel content in the hair of mothers which born babies at earlier gestational age were high, perhaps due to the greater exposure of metals from the environment on pregnant women. Level of Cr, Cd and Ni in hair of extremely premature babies was higher than in babies which were born at a later date. It may be possible due to improved functioning of placenta as a barrier to the micronutrients during final stages of fetal development.

Sialic acid expression in human fetal skeletal muscle during limb early myogenesis.

Investigations on animal models demonstrated that changes of sialic acid (SA) expression, particularly the polymeric form, in the skeletal muscle during embryonic and post-natal development seem to be related to muscle differentiation and functionality onset. The aim of this study was to evaluate the monomeric and polymeric SA expression in human skeletal muscle during early stages of fetal development, when important morphofunctional events occur. Specimens of fetal skeletal muscle from limb, between 9 and 12 weeks of gestation (wg), were obtained from 19 pregnant women. To investigate some morphofunctional features occurring during this development period, haematoxylin-eosin staining, tunel assay and immunohistochemistry for connexin-43 (Cx43) and parvalbumin were performed. SA expression and characterization was evaluated using lectin histochemistry (MAA, SNA, PNA, SBA, DBA), associated with enzymatic and chemical treatments. Polysialic acid (PSA) expression was also evaluated using immunohistochemistry. The results showed apoptotic myotubes between 9 and 10.5 wg, disappearing from 11 wg; Cx43 was more abundant in myotubes/myoblasts between 9 and 9.5 wg, decreasing and/or disappearing from 10 wg and parvalbumin was present in myotubes between 10 and 10.5 wg. PSA was revealed in myotubes/myoblasts from 9 to 10.5 wg; from 11 wg it was reduced or disappeared. Monomeric SA appeared in myotubes/myoblasts from 10 wg, increasing successively; acetylated SA was present from 11 wg. These findings demonstrated that changes in expression of various types of SA, occurring in human fetal skeletal muscle during early development, seem to be related to some morphofunctional aspects distinctive of this organogenesis crucial period.

Defective trophoblast invasion underlies fetal growth restriction and preeclampsia-like symptoms in the stroke-prone spontaneously hypertensive rat.

What is the impact of chronic hypertension on placental development, fetal growth and maternal outcome in the stroke-prone spontaneously hypertensive rat (SHRSP)? SHRSP showed an impaired remodeling of the spiral arteries and abnormal pattern of trophoblast invasion during placentation, which were associated with subsequent maternal glomerular injury and increased baseline hypertension as well as placental insufficiency and asymmetric fetal growth restriction (FGR). A hallmark in the pathogenesis of preeclampsia (PE) is abnormal placentation with defective remodeling of the spiral arteries preceding the onset of the maternal syndrome. Pregnancies affected by chronic hypertension display an increased risk for PE, often associated with poor maternal and fetal outcomes. However, the impact of chronic hypertension on the placentation process as well as the nature of the factors promoting the development of PE in pregnant hypertensive women remain elusive. Timed pregnancies [n = 5] were established by mating 10-12-week-old SHRSP and Wistar Kyoto (WKY, normotensive controls) females with congenic males. Maternal systolic blood pressures (SBPs) were recorded pre-mating, throughout pregnancy (GD1-19) and post-partum by the tail-cuff method. On selected dates, 24 h urine- and blood samples were collected, and animals were euthanized for isolation of implantation sites and kidneys for morphometrical analyses. The 24 h proteinuria and the albumin:creatinine ratio were used for evaluation of maternal renal function. Renal injury was assessed on periodic acid Schiff, Masson's trichrome and Sirius red stainings. Placental and fetal weights were recorded on gestation day (GD)18 and GD20, followed by determination of fetal cephalization indexes and developmental stage, according to the Witschi scale. Morphometric analyses of placental development were conducted on hematoxylin-eosin stained tissue sections collected on GD14 and GD18, and complemented with immunohistochemical evaluation of isolectin B4 binding for assessment of placental vascularization. Analyses of vascular wall alpha actin content, perforin-positive natural killer (NK) cells and cytokeratin expression by immunohistochemistry were used for evaluation of spiral artery remodeling and trophoblast invasion. SHRSP females presented significantly increased SBP records from GD13 to GD17 (SBPGD13 = 183.9 ± 3.9 mmHg, P < 0.005 versus baseline) and increased proteinuria at GD18 (P < 0.01 versus WKY). Histological examination of GD18 kidneys revealed glomerular enlargement and mesangial matrix expansion, which were not evident in pregnant WKY or age-matched virgin SHRSP. At GD20, SHRSP displayed a significant reduction of placental mass (P < 0.01 versus WKY) and signs of placental insufficiency (i.e. hypertrophy and reduced branching morphogenesis of the labyrinth layer), associated with decreased offspring weights and increased cephalization index (both P < 0.001 versus WKY) indicating asymmetric FGR. Notably, SHRSP placentas displayed an incomplete remodeling of spiral arteries starting as early as GD14, with luminal narrowing and reduced densities of perivascular NK cells followed by decreased infiltration of endovascular trophoblasts at GD18. n/a. A pitfall of the present study is the differences in the blood pressure profiles between rats and humans (i.e. unlike pregnancies affected by PE, blood pressure in SHRSP and other hypertensive rat models decreases pre-delivery), which limits extrapolation of the results. Our findings provide new insights on the role of chronic hypertension as a risk factor for PE by interfering with early events during the placentation process. The SHRSP strain represents an attractive model for further studies aimed at addressing the relative contribution of intrinsic (i.e. placental) and extrinsic (i.e. decidual/vascular) factors to defective spiral artery remodeling in pregnancies affected by PE. This work was supported by research grants from Fundación Florencio Fiorini to G.B., from Charité Stiftung to S.M.B. and University of Buenos Aires (UBACyt) to J.T. The authors have no competing interests to declare.

Rare trisomies: frequency, range, lethality at embryonic and fetal stages of prenatal development

Aim . The study of primary population frequency, mortality and share of rare autosomal trisomies at different stages of fetal development for the further determination of the expected proportion of false negative results at chromosome abnormalities (CA) selective diagnostics using during reproductive losses and prenatal diagnostics. Materials and methods. Karyotyping of 1808 samples of missed abortion concept products, 1572 induced abortions, 1329 chorionic villus biopsy samples, 2240 placenta biopsy samples, and 6120 samples of amniotic fluid (13069 total) was carried out. Results. The share of Т21,18,13 at pre-embryonic stage was only 6.33 %, while the share of “rare” trisomies was 93.67 %. In the first trimester the mean share of rare trisomies (Т1-12,14-17,19,20,22 ) was 41.13%; among prenatally diagnosed 11-14 weeks fetuses was 3.01 %, 15-22 weeks fetuses – 1.68 %, and after 23 weeks – 2.22 %. It means that the mean share of rare trisomies at prenatal diagnostics can be 2.3 % among newborns. Conclusion. The share of false negative results at autosomal trisomies detection using commercial selective test systems covering Т13,Т18,Т21,Т9 and Т22 in missed abortion group can be 41 %, and at prenatal diagnostics within 11-23 weeks – 2.3 %