Mark Hill (talk) 12:23, 16 June 2019 (AEST) Added this new page to capture updated references added throughout the site in the "Some Recent Findings". Entries are listed alphabetically by topic page, note that not all new references may be added to this current list. (More? New)
- Review - A mechanism for the effect of endocrine disrupting chemicals on placentation "Numerous recent studies have shown that endocrine disrupting chemicals (EDCs) in the body of pregnant women can pass through the placenta and be exposed to the fetus, leading to fetal development and cognitive impairment. Placentation through invasion of trophoblast cells and vascular remodeling is essential to maintaining maternal and fetal health throughout the pregnancy. Abnormal placentation can lead to pregnancy disorders such as preeclampsia (PE) and intrauterine growth retardation (IUGR). However, many studies have not been conducted on whether EDCs can inhibit the development and function of the placenta. Isolating placental tissues to analyze the effect of EDCs on placentation has several limitations. In this review, we discussed the types of EDCs that can pass through the placental barrier and accumulate in the placenta with relative outcome. EDCs can be released from a variety of products including plasticizers, pesticides, and retardant. We also discussed the development and dysfunction of the placenta when EDCs were treated on trophoblast cells or pregnant rodent models. The effects of EDCs on the placenta of livestock are also discussed, together with the molecular mechanism of EDCs acting in trophoblast cells. We describe how EDCs cross the membrane of trophoblasts to regulate signaling pathways, causing genetic and epigenetic changes that lead to changes in cell viability and invasiveness. Further studies on the effects of EDCs on placenta may draw attention to the correct use of products containing EDCs during pregnancy."
- Toxicokinetics of bisphenol A, bisphenol S, and bisphenol F in a pregnancy sheep model "Bisphenol A (BPA), S (BPS), and F (BPF) are among the most abundant bisphenols detected in humans, yet pregnancy toxicokinetics for BPS or BPF remain unknown. Because gestational BPS can disrupt placental function and result in reproductive and metabolic disorders in the progeny, the aim of the study was to investigate BPS and BPF toxicokinetics during pregnancy using an in vivo approach. ... We observed significant differences in half-life, maximum concentration, and total body clearance in maternal circulation among bisphenols. Longer half-lives were observed in fetal vs. maternal circulation for all bisphenols. Fetal toxicokinetics differed among bisphenols with BPS having the longest fetal half-life. All bisphenols reached basal levels at 48 h in maternal plasma, but were still detectable in amniotic fluid, fetal urine, and fetal plasma at 72 h. In this first pregnancy toxicokinetic study of BPS and BPF we have demonstrated maternal and fetal toxicokinetic differences among all three bisphenols. Higher BPS persistence in the fetal compartment warrants studies into progeny adverse outcomes following gestational exposure. Additionally, toxicokinetic differences among bisphenols call for a more careful approach when extrapolating kinetic information from one bisphenol chemical to another."
- SLC9A3 Affects Vas Deferens Development and Associates with Taiwanese Congenital Bilateral Absence of the Vas Deferens "The pathophysiology of Taiwanese congenital bilateral absence of the vas deferens (CBAVD) is different from that in Caucasians. In particular, major cystic fibrosis transmembrane conductance regulator (CFTR) mutations and cystic fibrosis are absent in the former. DISCUSSION: Our findings build upon previous data associated with CBAVD pathogenesis. Here, we now report for the first time an association between CBAVD and loss of SLC9A3 and propose that specific defects in the reproductive duct due to SLC9A3 variants drive CBAVD development. CONCLUSION: The data implicate loss of SLC9A3 as a basis of Taiwanese CBAVD and highlight SLC9A3 function in reproduction." OMIM - SLC9A3
fetal growth restriction
- Outcomes in patients with early-onset fetal growth restriction without fetal or genetic anomalies "Early-onset fetal growth restriction is associated with poor pregnancy outcomes, but frequently is due to fetal structural or chromosomal abnormalities. The objective of this study was to determine outcomes in patients with early-onset fetal growth restriction without diagnosed fetal or genetic anomalies and to identify additional risk factors for poor outcomes in these patients. This was retrospective cohort study of singleton pregnancies in women with early-onset growth restriction defined as a sonographic estimated fetal weight <10% diagnosed between 16-28 weeks' gestation. We excluded all women with a fetal structural or chromosomal abnormality diagnosed prenatally. Data on pregnancy characteristics and outcomes were collected and analyzed for estimated fetal weight <10% and ≤5%. A nested case-control study within the cohort of patients with ongoing pregnancies was then performed to identify risk factors associated with poor pregnancy outcome using chi-squared test. One hundred forty-two patients were identified who met inclusion and exclusion criteria and 20 patients were found to have fetal structural or chromosomal abnormalities. In the remaining 122 patients, the incidence of intrauterine fetal demise was 5.7% and there were high rates of preterm birth <37 weeks (20%), birth weight <10% (59.3%), and gestational hypertension (14.1%). Later gestational age at diagnosis and the presence of echogenic bowel and abnormal initial umbilical artery Dopplers were associated with poor pregnancy outcome (22.56 versus 20.86 weeks, p = .046), (17.4 versus 2.2%, OR 9.68, 95%CI 1.65-56.73), and (35.3 versus 0%, OR 4.46, 95%CI 2.65-7.50) respectively. Patients with early-onset fetal growth restriction with no fetal structural or genetic abnormality have a high risk of poor pregnancy outcomes. Gestational age at diagnosis and certain ultrasound findings are associated with poor pregnancy outcome."
- Bmp4 is an essential growth factor for the initiation of genital tubercle (GT) outgrowth "The external genitalia are appendage organs outgrowing from the posterior body trunk. Murine genital tubercle (GT), anlage of external genitalia, initiates its outgrowth from embryonic day (E) E10.5 as a bud structure. Several growth factors such as fibroblast growth factor (FGF), Wnt and Sonic hedgehog (Shh) are essential for the GT outgrowth. However, the mechanisms of initiation of GT outgrowth are poorly understood. We previously identified bone morphogenetic protein (Bmp) signaling as a negative regulator for GT outgrowth. We show here novel aspects of Bmp4 functions for GT outgrowth. We identified the Bmp4 was already expressed in cloaca region at E9.5, before GT outgrowth. To analyze the function of Bmp4 at early stage for the initiation of GT outgrowth, we utilized the Hoxa3-Cre driver and Bmp4 flox/flox mouse lines. Hoxa3 Cre/+ ; Bmp4 flox/flox mutant mice showed the hypoplasia of GT with reduced expression of outgrowth promoting genes such as Wnt5a, Hoxd13 and p63, whereas Shh expression was not affected. Formation of distal urethral epithelium (DUE) marked by the Fgf8 expression is essential for controlling mesenchymal genes expression in GT and subsequent its outgrowth. Furthermore, Fgf8 expression was dramatically reduced in such mutant mice indicating the defective DUE formation. Hence, current results indicate that Bmp4 is an essential growth factor for the initiation of GT outgrowth independent of Shh signaling. Thus, Bmp4 positively regulates for the formation of DUE. The current study provides new insights into the function of Bmp signaling at early stage for the initiation of GT outgrowth." BMP
- Development of the Basal Hypothalamus through Anisotropic Growth "The adult hypothalamus is subdivided into distinct domains: pre-optic, anterior, tuberal and mammillary. Each domain harbours an array of neurons that act together to regulate homeostasis. The embryonic origins and development of hypothalamic neurons, however, remains enigmatic. Here we summarise recent studies in model organisms that challenge current views of hypothalamic development, which traditionally have attempted to map adult domains to correspondingly-located embryonic domains that expand isotropically. Instead, new studies indicate that hypothalamic neurons arise from progenitor cells that undergo anisotropic growth in different dimensions. Here we describe how a multipotent Shh/ Fgf10-expressing progenitor population gives rise to progenitors that grow anisotropically, expanding to a greater extent than other progenitors and giving rise to cells throughout the basal hypothalamus. Further, Shh/Fgf10+ive -derived progenitors grow sequentially in different directions from the multipotent Shh/ Fgf10 population: first, a subset displaced rostrally give rise to anterior-ventral/tuberal neuronal progenitors, then a subset displaced caudally give rise to mammillary neuronal progenitors; finally, a subset(s) displaced ventrally give rise to tuberal infundibular glial progenitors. As this occurs, stable populations of Shh+ive and Fgf10+ive progenitors form. We describe current understanding of the mechanisms that induce Shh/Fgf10+ive progenitors, and begin to direct their differentiation to anterior-ventral/tuberal neuronal progenitors, mammillary neuronal progenitors and tuberal infundibular progenitors. Together these studies suggest a new model for hypothalamic development that we term the Anisotropic growth model. We discuss the implications of the model for understanding the origins of adult hypothalamic neurons."
- Risk of spontaneous preterm birth and fetal growth associates with fetal SLIT2 "Spontaneous preterm birth (SPTB) is the leading cause of neonatal death and morbidity worldwide. Both maternal and fetal genetic factors likely contribute to SPTB. We performed a genome-wide association study (GWAS) on a population of Finnish origin that included 247 infants with SPTB (gestational age [GA] < 36 weeks) and 419 term controls (GA 38-41 weeks). The strongest signal came within the gene encoding slit guidance ligand 2 (SLIT2; rs116461311, minor allele frequency 0.05, p = 1.6×10-6). ... Our results show that the fetal SLIT2 variant and both SLIT2 and ROBO1 expression in placenta and trophoblast cells may be correlated with susceptibility to SPTB. SLIT2-ROBO1 signaling was linked with regulation of genes involved in inflammation, PSG genes, decidualization and fetal growth. We propose that this receptor-ligand couple is a component of the signaling network that promotes SPTB." OMIM - SLIT2 | OMIM - ROBO1
- XY oocytes of sex-reversed females with a Sry mutation deviate from the normal developmental process beyond the mitotic stage "The fertility of sex-reversed XY female mice is severely impaired by a massive loss of oocytes and failure of meiotic progression. This phenomenon remains an outstanding mystery. We sought to determine the molecular etiology of XY oocyte dysfunction by generating sex-reversed females that bear genetic ablation of Sry, a vital sex determination gene, on an inbred C57BL/6 background. These mutant mice, termed XYsry- mutants, showed severe attrition of germ cells during fetal development, resulting in the depletion of ovarian germ cells prior to sexual maturation. Comprehensive transcriptome analyses of primordial germ cells (PGCs) and postnatal oocytes demonstrated that XYsry- females had deviated significantly from normal developmental processes during the stages of mitotic proliferation. The impaired proliferation of XYsry- PGCs was associated with aberrant β-catenin signaling and the excessive expression of transposable elements. Upon entry to the meiotic stage, XYsry- oocytes demonstrated extensive defects, including the impairment of crossover formation, the failure of primordial follicle maintenance, and no capacity for embryo development. Together, these results suggest potential molecular causes for germ cell disruption in sex-reversed female mice, thereby providing insights into disorders of sex differentiation in humans, such as "Swyer syndrome," in which patients with an XY karyotype present as typical females and are infertile."
- Venous Collateral Pathways in Superior Thoracic Inlet Obstruction: A Systematic Analysis of Anatomy, Embryology, and Resulting Patterns "For this study, we reviewed 56 standard-of-care CT examinations over a timespan of 2 years from patients with superior thoracic inlet venous obstruction and identified eight thoracic collateral pathways for venous blood return to the right heart. We evaluated each pathway individually from an anatomic and a pathophysiologic perspective for a better understanding of how such pathways form and what patterns can be expected. ... Recognizing imaging findings associated with venous collateral pathways may prevent misdiagnosis or unnecessary follow-up examinations. Furthermore, knowledge of these collateral pathways and an understanding of the underlying cause can support interventional radiologists and vascular surgeons in planning interventional procedures and revascularization procedures."
- ↑ Yang C, Song G & Lim W. (2019). A mechanism for the effect of endocrine disrupting chemicals on placentation. Chemosphere , 231, 326-336. PMID: 31132539 DOI.
- ↑ Gingrich J, Pu Y, Ehrhardt R, Karthikraj R, Kannan K & Veiga-Lopez A. (2019). Toxicokinetics of bisphenol A, bisphenol S, and bisphenol F in a pregnancy sheep model. Chemosphere , 220, 185-194. PMID: 30583211 DOI.
- ↑ Wu YN, Chen KC, Wu CC, Lin YH & Chiang HS. (2019). SLC9A3 Affects Vas Deferens Development and Associates with Taiwanese Congenital Bilateral Absence of the Vas Deferens. Biomed Res Int , 2019, 3562719. PMID: 30956978 DOI.
- ↑ Gupta S, Naert M, Lam-Rachlin J, Monteagudo A, Rebarber A, Saltzman D & Fox NS. (2019). Outcomes in patients with early-onset fetal growth restriction without fetal or genetic anomalies. J. Matern. Fetal. Neonatal. Med. , 32, 2662-2666. PMID: 29478342 DOI.
- ↑ Kajioka D, Suzuki K, Nakada S, Matsushita S, Miyagawa S, Takeo T, Nakagata N & Yamada G. (2019). Bmp4 is an essential growth factor for the initiation of genital tubercle (GT) outgrowth. Congenit Anom (Kyoto) , , . PMID: 30714224 DOI.
- ↑ Fu T, Pearson C, Towers M & Placzek M. (2019). Development of the Basal Hypothalamus through Anisotropic Growth. J. Neuroendocrinol. , , e12727. PMID: 31050853 DOI.
- ↑ Tiensuu H, Haapalainen AM, Karjalainen MK, Pasanen A, Huusko JM, Marttila R, Ojaniemi M, Muglia LJ, Hallman M & Rämet M. (2019). Risk of spontaneous preterm birth and fetal growth associates with fetal SLIT2. PLoS Genet. , 15, e1008107. PMID: 31194736 DOI.
- ↑ Sakashita A, Wakai T, Kawabata Y, Nishimura C, Sotomaru Y, Alavattam KG, Namekawa SH & Kono T. (2019). XY oocytes of sex-reversed females with a Sry mutation deviate from the normal developmental process beyond the mitotic stage†. Biol. Reprod. , 100, 697-710. PMID: 30289439 DOI.
- ↑ Meier A & Alkadhi H. (2019). Venous Collateral Pathways in Superior Thoracic Inlet Obstruction: A Systematic Analysis of Anatomy, Embryology, and Resulting Patterns. AJR Am J Roentgenol , , 1-11. PMID: 31039029 DOI.