Most of future population growth will take place in the world's cities and towns. Yet, there is no well-established, consistent way to measure either urban land or people. Even census-based urban ...concepts and measures undergo frequent revision, impeding rigorous comparisons over time and place. This study presents a new spatial approach to derive consistent urban proxies for the US. It compares census-designated urban blocks with proxies for land-based classifications of built-up areas derived from time-series of the Global Human Settlement Layer (GHSL) for 1990-2010. This comparison provides a new way to understand urban structure and its changes: Most land that is more than 50% built-up, and people living on such land, are officially classified as urban. However, 30% of the census-designated urban population and land is located in less built-up areas that can be characterized as mainly suburban and peri-urban in nature. Such insights are important starting points for a new urban research program: creating globally and temporally consistent proxies to guide modelling of urban change.
Prenatal treatment of virilizing congenital adrenal hyperplasia in female fetuses via maternal dexamethasone (Dex) therapy (1-1.5 mg/day) from first trimester to birth was associated with excessive ...weight gain (47-56 pounds at 35-37 weeks gestation), Cushingoid facial features, severe striae resulting in permanent scarring, and hyperglycemic response (8-11.7 nmol/L) to oral glucose administration in all our experience (three cases). Other symptoms included hypertension, gastrointestinal intolerance, or extreme irritability. Previous pregnancies were uncomplicated by these problems. In each case, first or second trimester amniotic fluid 17-hydroxyprogesterone (17OHP, 17-41 nmol/L; normal less than 0.4 nmol/L), androstenedione (22-31 nmol/L, normal less than 5 nmol/L), and testosterone levels (0.54-0.7 nmol/L, normal less than 0.4 nmol/L) during Dex treatment were elevated regardless of the newborn genital outcome. Maternal serum estriol (E3) levels in one mother (normal newborn genitalia) were consistently low (less than 0.2 nmol/L) during the second and third trimester. In two mothers (partially virilized newborn genitalia) initial second trimester E3 levels were unsuppressed (11, 17.4 nmol/L) and suppressed (less than 1.4 nmol/L) following short-term increased dose.
prenatal Dex treatment of virilizing congenital adrenal hyperplasia at a dose of 1-1.5 mg daily throughout gestation is associated with significant maternal side effects. Parents should be informed of these side effects before initiation of treatment. Careful monitoring for signs of side effects, medical intervention when necessary, and lowering of Dex dose during the second half of gestation would minimize the side effects. Maternal serum E3 levels appear useful for prediction of fetal outcome while amniotic fluid steroid levels may not.
We investigated peripheral androgen metabolic activity in 54 hirsute females (HF) by evaluating the serum 3 alpha-androstanediol glucuronide (3AG) concentration, hirsutism score (HS), and etiology of ...hirsutism. Based on basal and ACTH-stimulated steroid profiles (1 h post-Cortrosyn, 0.25 mg, i.v. bolus), the causes of hirsutism were determined to be increased adrenal androgen production (greater than 2 SD above normal mean), increased ovarian testosterone (T) production (greater than 2 SD above normal mean basal T of ovarian source only), or idiopathic cause (normal steroid profile). Serum 3AG levels in each group of HF were significantly higher (P less than 0.01-0.001) than those in normal females normal: 2.9 +/- 0.94 nmol/L (n = 28); HF: increased adrenal androgen production of undefined cause, 7.7 +/- 7.5 nmol/L (n = 14); 21-hydroxylase deficiency, 7.6 +/- 7.4 nmol/L (n = 5); increased ovarian T production 5.5 +/- 3.5 nmol/L (n = 18); idiopathic cause, 5.8 +/- 4.8 nmol/L (n = 17). However, normal 3AG levels (less than 5.2 nmol/L) were present in 50-67% of HF in each group. Collectively, 3AG levels in HF correlated significantly (P less than 0.01) with dehydroepiandrosterone (DHEA; r = 0.41) and DHEA sulfate (DS; r = 0.44), while the correlation with androstenedione (r = 0.15) or T (r = 0.19) was not significant. Serum 3AG and adrenal androgen levels decreased in all subjects after dexamethasone treatment (0.5-1 mg at hour of sleep; 2 mg/day for 3-5 days). The correlation between 3AG and HS was significant (r = 0.6-0.74; P less than 0.01-0.001) only in HF with increased adrenal androgen secretion and idiopathic cause, and was not significant (r = 0.42) in HF with increased ovarian T secretion. There was no significant correlation between androgen levels and HS. We conclude that the serum 3AG level was not consistently elevated in HF and did not differ significantly between the various causes. Significant correlations between 3AG and DHEA/DS levels, and the simultaneous decrease in 3AG and adrenal androgens after dexamethasone administration in HF suggest that adrenal androgens contribute significantly to 3AG production. The significant correlation between 3AG and HS in HF with increased adrenal androgen secretion and idiopathic cause indirectly suggests an adrenal androgen contribution to both 3AG production and hirsutism in these HF. The insignificant correlation between 3AG and HS in HF with increased ovarian T secretion may result from a confounding effect of ovarian T on hirsutism.
To determine whether serum 3 alpha-androstanediol glucuronide (3AG) reflects the overall effect of integrated adrenal androgen secretion in the virilizing form of congenital adrenal hyperplasia ...(CVAH), circadian levels (0800, 1200, 1600, and 2000 h) of serum 3AG and 17-hydroxyprogesterone (17OHP) or 11-deoxycortisol (S), androstenedione (A), testosterone (T), and 24-h urinary 17-ketosteroids (17KS) were examined in seven patients (pts) with classical 21-hydroxylase deficiency (21OHD) and one pt with classical 11 beta-hydroxylase deficiency (11 beta OHD). Hormonal studies were conducted during the second day of dexamethasone (Dex) administration (2 mg/day). In five poorly controlled CVAH pts, including the 11 beta OHD pt, highly elevated baseline morning (AM) serum 17OHP or S as well as A levels, and elevated AM T levels in three pts decreased markedly in the evening (PM), while elevated serum 3AG showed no significant circadian changes; 17KS levels were markedly elevated for age. During Dex, moderately or slightly elevated AM 17OHP, A, or T in two to four pts with 21OHD decreased to the normal range in the PM. In the pt with 11 beta OHD, S, A, and T levels were suppressed. 3AG levels were modestly elevated or normal, without circadian changes, in these pts; 17KS levels were elevated or normal. In two other 21OHD pts, modestly elevated AM baseline 17OHP and A levels decreased in the PM; elevated AM T decreased in one pt in the PM; modestly elevated 3AG levels showed no circadian changes; 17KS levels were modestly elevated. During Dex, normal or slightly elevated serum steroids and 17KS levels were associated with normal or high normal 3AG levels without circadian changes. In one postpubertal female with 21OHD, modestly elevated AM baseline 17OHP levels decreased at 2000 h; normal A and T levels throughout the day and low normal 17KS were associated with slightly low 3AG levels, without circadian variation. During Dex treatment, normal 17OHP, A, T, and low 17KS levels were associated with low 3AG levels without circadian variation. In all pts as a group, an excellent correlation (r = 0.9) was found between either 0800 h or mean, or 2000 h serum 3AG levels and 17KS. In addition, AM and PM serum 3AG levels in five normal women were similar. We conclude that the high correlation between serum 3AG and urinary 17KS and the absence of a significant circadian variation in 3AG indicate that serum 3AG, regardless of sample time, is a useful metabolic index of integrated adrenal androgen secretion in CVAH.
To investigate the role of adrenal androgens in 3 alpha-androstanediol glucuronide (3AG) production in childhood, we compared serum 3AG and androgen levels dehydroepiandrosterone (DHEA), DHEA sulfate ...(DS), androstenedione (delta 4-A), and testosterone (T) in 32 children with premature pubarche due to idiopathic premature adrenarche (IPA; n = 26), partial 21-hydroxylase deficiency (n = 2), or 3 beta-hydroxysteroid dehydrogenase deficiency (n = 4) with those in 36 normal prepubertal (18 males and 18 females) and 22 normal pubertal Tanner II-III subjects (10 males and 12 females). Serum 3AG (2.7 +/- 2.0 nmol/L) and all androgen concentrations in children with IPA were significantly higher (P less than 0.05-0.001) than those in normal prepubertal children (3AG, 0.8 +/- 0.5 nmol/L). Serum 3AG and androgen levels, except T, in all children with premature pubarche due to 21-hydroxylase deficiency or 3 beta-hydroxysteroid dehydrogenase deficiency were higher than those in the normal prepubertal children. Serum 3AG and all androgen levels in normal Tanner II-III male (3AG, 3.8 +/- 1.7 nmol/L) or female (3AG, 1.74 +/- 0.52 nmol/L) subjects were also significantly higher (P less than 0.05-0.001) than those in prepubertal children. Serum 3AG, DHEA, DS, and delta 4-A levels in children with IPA were similar to those in normal Tanner II-III females or males, but serum T in children with IPA (0.37 +/- 0.2 nmol/L) was significantly lower (P less than 0.05-0.001) than that in normal pubertal females (0.71 +/- 0.37 nmol/L) or males (4.5 +/- 2.6 nmol/L). In the combined group (n = 88), 3AG levels correlated better with serum DS (r = 0.7), DHEA (r = 0.6), and delta 4-A (r = 0.52), than with T (r = 0.31) levels. These data suggest that the weak adrenal androgens DS, DHEA, and delta 4-A contribute substantially to 3AG production in premature and normal pubarche.
Human embryonic stem cells (hESCs) typically exhibit “primed” pluripotency, analogous to stem cells derived from the mouse post-implantation epiblast. This has led to a search for growth conditions ...that support self-renewal of hESCs akin to hypomethylated naive epiblast cells in human pre-implantation embryos. We have discovered that reverting primed hESCs to a hypomethylated naive state or deriving a new hESC line under naive conditions results in the establishment of Stage Specific Embryonic Antigen 4 (SSEA4)-negative hESC lines with a transcriptional program resembling the human pre-implantation epiblast. In contrast, we discovered that the methylome of naive hESCs in vitro is distinct from that of the human epiblast in vivo with loss of DNA methylation at primary imprints and a lost “memory” of the methylation state of the human oocyte. This failure to recover the naive epiblast methylation landscape appears to be a consistent feature of self-renewing hypomethylated naive hESCs in vitro.
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•Reversion or derivation of hESCs in 5iLAF results in SSEA4-negative cells•SSEA4-negative hESCs show gene expression consistent with naive pluripotency•Naive hESCs show lost “memory” of gamete and blastocyst methylation•Imprinting is lost in naive hESCs
Pastor and colleagues show that reversion of primed hESCs in 5iLAF, or derivation of hESCs in 5iLAF, results in a population of naive cells characterized by loss of the marker SSEA4. However, these cells have a methylation pattern with little resemblance to blastocyst and near total loss of imprinting.
The donor–acceptor ligands 11-(4-diphenylaminophenyl)dipyrido3,2-a:2′,3′-cphenazine (dppz-PhNPh2) and 11-(4-dimethylaminophenyl)dipyrido3,2-a:2′,3′-cphenazine (dppz-PhNMe2), and their rhenium ...complexes, Re(CO)3X (X = Cl–, py, 4-dimethylaminopyridine (dmap)), are reported. Crystal structures of the two ligands were obtained. The optical properties of the ligands and complexes are dominated by intraligand charge transfer (ILCT) transitions from the amine to the dppz moieties with λabs = 463 nm (ε = 13 100 M–1 cm–1) for dppz-PhNMe2 and with λabs = 457 nm (ε = 16 900 M–1 cm–1) for dppz-PhNPh2. This assignment is supported by CAM-B3LYP TD-DFT calculations. These ligands are strongly emissive in organic solvents and, consistent with the ILCT character, show strong solvatochromic behavior. Lippert–Mataga plots of the data are linear and yield Δμ values of 22 D for dppz-PhNPh2 and 20 D for dppz-PhNMe2. The rhenium(I) complexes are less emissive, and it is possible to measure resonance Raman spectra. These data show relative band intensities that are virtually unchanged from λexc = 351 to 532 nm, consistent with a single dominant transition in the visible region. Resonance Raman excitation profiles are solvent sensitive; these data are modeled using wavepacket theory yielding reorganization energies ranging from 1800 cm–1 in toluene to 6900 cm–1 in CH3CN. The excited state electronic absorption and infrared spectroscopy reveal the presence of dark excited states with nanosecond to microsecond lifetimes that are sensitive to the ancillary ligand on the rhenium. These dark states were assigned as phenazine-based 3ILCT states by time-resolved infrared spectroscopy. Time-resolved infrared spectroscopy shows transient features in which Δν(CO) is approximately −7 cm–1, consistent with a ligand-centered excited state. Evidence for two such states is seen in mid-infrared transient spectra.
In humans, germline competency and the specification of primordial germ cells (PGCs) are thought to occur in a restricted developmental window during early embryogenesis. Despite the importance of ...specifying the appropriate number of PGCs for human reproduction, the molecular mechanisms governing PGC formation remain largely unexplored. Here, we compared PGC-like cell (PGCLC) differentiation from 18 independently derived human embryonic stem cell (hESC) lines, and discovered that the expression of primitive streak genes were positively associated with hESC germline competency. Furthermore, we show that chemical inhibition of TGFβ and WNT signaling, which are required for primitive streak formation and CRISPR/Cas9 deletion of Eomesodermin (EOMES), significantly impacts PGCLC differentiation from hESCs. Taken together, our results suggest that human PGC formation involves signaling and transcriptional programs associated with somatic germ layer induction and expression of EOMES. Summary Sentence EOMES induction in the progenitor cell prior to germ cell formation in vitro from hESCs is required for efficient PGC-like cell formation.
Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)/CRISPR-associated system (Cas9)-mediated gene editing of human hematopoietic stem cells (hHSCs) is a promising strategy for the ...treatment of genetic blood diseases through site-specific correction of identified causal mutations. However, clinical translation is hindered by low ratio of precise gene modification using the corrective donor template (homology-directed repair, HDR) to gene disruption (nonhomologous end joining, NHEJ) in hHSCs. By using a modified version of Cas9 with reduced nuclease activity in G1 phase of cell cycle when HDR cannot occur, and transiently increasing the proportion of cells in HDR-preferred phases (S/G2), we achieved a four-fold improvement in HDR/NHEJ ratio over the control condition in vitro, and a significant improvement after xenotransplantation of edited hHSCs into immunodeficient mice. This strategy for improving gene editing outcomes in hHSCs has important implications for the field of gene therapy, and can be applied to diseases where increased HDR/NHEJ ratio is critical for therapeutic success. Stem Cells 2019;37:284-294.
Restricting the localization of the histone H3 variant CENP-A (Cse4 in yeast, CID in flies) to centromeres is essential for faithful chromosome segregation. Mislocalization of CENP-A leads to ...chromosomal instability (CIN) in yeast, fly and human cells. Overexpression and mislocalization of CENP-A has been observed in many cancers and this correlates with increased invasiveness and poor prognosis. Yet genes that regulate CENP-A levels and localization under physiological conditions have not been defined. In this study we used a genome-wide genetic screen to identify essential genes required for Cse4 homeostasis to prevent its mislocalization for chromosomal stability. We show that two Skp, Cullin, F-box (SCF) ubiquitin ligases with the evolutionarily conserved F-box proteins Met30 and Cdc4 interact and cooperatively regulate proteolysis of endogenous Cse4 and prevent its mislocalization for faithful chromosome segregation under physiological conditions. The interaction of Met30 with Cdc4 is independent of the D domain, which is essential for their homodimerization and ubiquitination of other substrates. The requirement for both Cdc4 and Met30 for ubiquitination is specifc for Cse4; and a common substrate for Cdc4 and Met30 has not previously been described. Met30 is necessary for the interaction between Cdc4 and Cse4, and defects in this interaction lead to stabilization and mislocalization of Cse4, which in turn contributes to CIN. We provide the first direct link between Cse4 mislocalization to defects in kinetochore structure and show that SCF-mediated proteolysis of Cse4 is a major mechanism that prevents stable maintenance of Cse4 at non-centromeric regions, thus ensuring faithful chromosome segregation. In summary, we have identified essential pathways that regulate cellular levels of endogenous Cse4 and shown that proteolysis of Cse4 by SCF-Met30/Cdc4 prevents mislocalization and CIN in unperturbed cells.
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