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To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.ydbio.2009.08.022 Byline: David R.C. Natale (a), Myriam Hemberger (b), Martha Hughes (a), James C. Cross (a) Keywords: Placenta; Trophoblast; Activin; Nodal; TGF-[beta]; Trophoblast stem cell; Labyrinth; Mouse Abstract: Prolonged maintenance of trophoblast stem (TS) cells requires fibroblast growth factor (FGF) 4 and embryonic fibroblast feeder cells or feeder cell-conditioned medium. Previous studies have shown that TGF-[beta] and Activin are sufficient to replace embryonic fibroblast-conditioned medium. Nodal, a member of the TGF-[beta] superfamily, is also known to be important in vivo for the maintenance of TS cells in the developing placenta. Our current studies indicate that TS cells do not express the Nodal co-receptor, Cripto, and do not respond directly to active Nodal in culture. Conversely, Activin subunits and their receptors are expressed in the placenta and TS cell cultures, with Activin predominantly expressed by trophoblast giant cells (TGCs). Differentiation of TS cells in the presence of TGC-conditioned medium or exogenous Activin results in a reduction in the expression of TGC markers. In line with TGC-produced Activin representing the active component in TGC-conditioned medium, this differentiation-inhibiting effect can be reversed by the addition of follistatin. Additional experiments in which TS cells were differentiated in the presence or absence of exogenous Activin or TGF-[beta] show that Activin but not TGF-[beta] results in the maintenance of expression of TS cell markers, prolongs the expression of syncytiotrophoblast markers, and significantly delays the expression of spongiotrophoblast and TGC markers. These results suggest that Activin rather than TGF-[beta] (or Nodal) acts directly on TS cells influencing both TS cell maintenance and cell fate, depending on whether the cells are also exposed to FGF4. Author Affiliation: (a) Department of Comparative Biology and Experimental Medicine, Faculty of Veterinary Medicine, The University of Calgary, HSC Room 2279, 3330 Hospital Drive NW, Calgary, AB, Canada T2N 4N1 (b) Laboratory of Developmental Genetics and Imprinting, The Babraham Institute, Cambridge, UK Article History: Received 27 July 2009; Accepted 18 August 2009

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.ydbio.2007.01.009 Byline: David G. Simmons (a), Amanda L. Fortier (b), James C. Cross (a) Keywords: Murine placenta; Trophoblast; Trophoblast giant cell; Retinoic acid Abstract: Trophoblast giant cells (TGCs) are the first terminally differentiated subtype to form in the trophoblast cell lineage in rodents. In addition to mediating implantation, they are the main endocrine cells of the placenta, producing several hormones which regulate the maternal endocrine and immune systems and promote maternal blood flow to the implantation site. Generally considered a homogeneous population, TGCs have been identified by their expression of genes encoding placental lactogen 1 or proliferin. In the present study, we have identified a number of TGC subtypes, based on morphology and molecular criteria and demonstrated a previously underappreciated diversity of TGCs. In addition to TGCs that surround the implantation site and form the interface with the maternal deciduas, we demonstrate at least three other unique TGC subtypes: spiral artery-associated TGCs, maternal blood canal-associated TGCs and a TGC within the sinusoidal spaces of the labyrinth layer of the placenta. All four TGC subtypes could be identified based on the expression patterns of four genes: Pl1, Pl2, Plf (encoded by genes of the prolactin/prolactin-like protein/placental lactogen gene locus), and Ctsq (from a placental-specific cathepsin gene locus). Each of these subtypes was detected in differentiated trophoblast stem cell cultures and can be differentially regulated; treatment with retinoic acid induces Pl1/Plf.sup.+ TGCs preferentially. Furthermore, cell lineage tracing studies indicated unique origins for different TGC subtypes, in contrast with previous suggestions that secondary TGCs all arise from Tpbpa.sup.+ ectoplacental cone precursors. Author Affiliation: (a) Department of Biochemistry and Molecular Biology, University of Calgary, Faculty of Medicine, HSC Room 2279, 3330 Hospital Drive, N.W., Calgary, Alberta, Canada T2N 4N1 (b) Department of Human Genetics, Montreal Children's Hospital Research Institute, Montreal, Quebec, Canada H3Z 2Z3 Article History: Received 28 September 2006; Revised 19 December 2006; Accepted 4 January 2007

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.ydbio.2006.03.006 Byline: Brent M. Bany (a), James C. Cross (a)(b) Keywords: Embryo implantation; Uterus; Trophoblast; Conceptus Abstract: The uterus undergoes a series of dramatic changes in response to an implanting conceptus that, in some mammalian species, includes differentiation of the endometrial stroma into decidual tissue. This process, called decidualization, can be induced artificially in rodents indicating that the conceptus may not be essential for a proper maternal response in early pregnancy. In order to test this hypothesis, we determined if and how the conceptus affects uterine gene expression. We identified 5 genes (Angpt1, Angpt2, Dtprp, G1p2 and Prlpa) whose steady-state levels in the uterus undergoing decidualization depends on the presence of a conceptus. In situ hybridization revealed region-specific effects which suggested that various components of the conceptus and more than one signal from the conceptus are likely responsible for altering decidual cell function. Using cell culture models we found that trophoblast giant cells secrete a type I interferon-like molecule which can induce G1p2 expression in endometrial stromal cells. Finally, decidual Prlpa expression was reduced in the uterus adjacent to Hand1- and Ets2-deficient embryos, suggesting that normal trophoblast giant cells in the placenta are required for the conceptus-dependent effects on Prlpa expression in the mesometrial decidua. Overall, these results provide support for the hypothesis that molecular signals from the mouse conceptus have local effects on uterine gene expression during decidualization. Author Affiliation: (a) Department of Biochemistry and Molecular Biology, University of Calgary, Calgary, Canada (b) Department of Obstetrics and Gynaecology, University of Calgary, Calgary, Canada Article History: Received 21 October 2005; Revised 9 February 2006; Accepted 6 March 2006

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.ydbio.2005.05.010 Byline: David G. Simmons, James C. Cross Keywords: Trophoblast lineage; Subtype specification; Mouse placenta; Stem cell maintenance Abstract: Cells of the trophoblast lineage make up the epithelial compartment of the placenta, and their rapid development is essential for the establishment and maintenance of pregnancy. A diverse array of specialized trophoblast subtypes form throughout gestation and are responsible for mediating implantation, as well as promotion of blood to the implantation site, changes in maternal physiology, and nutrient and gas exchange between the fetal and maternal blood supplies. Within the last decade, targeted mutations in mice and the study of trophoblast stem cells in vitro have contributed greatly to our understanding of trophoblast lineage development. Here, we review recent insights into the molecular pathways regulating trophoblast lineage segregation, stem cell maintenance, and subtype differentiation. Author Affiliation: Genes and Development Research Group, Department of Biochemistry and Molecular Biology, University of Calgary, HSC Room 2279, 3330 Hospital Drive N.W., Calgary, AB, Canada T2N 4N1 Article History: Received 21 January 2005; Revised 4 May 2005; Accepted 6 May 2005

Trophoblast cells are characterized by an invasive behavior into the surrounding uterine tissue. In rodents, an early peri-/endovascular type of invasion exerted by trophoblast giant cells can be distinguished from a late interstitial type carried out by glycogen trophoblast cells. Analysis of the molecular mechanisms of trophoblast invasion has been hampered, however, by the complex temporal and spatial patterns of invasion. We utilized trophoblast stem (TS) cell fines to study trophoblast invasion in vitro and to establish a model that facilitates investigation of this process on the molecular level. Our results showed that trophoblast giant cells that differentiate from TS cells in vitro are capable of penetrating a reconstituted basement membrane matrix. Consequently, invasion rates were increased in various giant cell differentiation-promoting conditions. We also derived TS cell lines that are homozygous for a mutation of the Hand1 transcription factor. The Hand[1.sup.-/-] TS cells showed reduced levels of giant cell differentiation and exhibited an approximately 50% decrease in invasion rates. In summary, trophoblast giant cells that differentiate from TS cells in vitro recapitulate the invasive capacity of normal trophoblast cells in vivo. The TS cell system is a valuable tool to identify and quantitatively study regulators of trophoblast invasion. Keywords: Trophoblast stem cells; Trophoblast giant cells; Invasion; Matrigel

The trophoblast cell lineage is an interesting model system because it is composed of a limited number of cell types that are spatially patterned. Trophoblast stem (TS) cells reside within a layer called the chorion and either remain as stem cells or differentiate into spongiotrophoblast (SpT), trophoblast giant (TG) cells or syncytiotrophoblast cells (SynT) of the labyrinth. Maintenance of the TS phenotype is dependent on stimulation by FGF4, whereas differentiation and/or maintenance of the differentiated derivatives are dependent on key transcription factors: Mash2 for SpT, Hand1 for TG cells and Gcm1 for SynT cells. TS cells proliferate and retain their stem cell phenotype in culture in response to FGF4 and an additional factor(s) that can be provided by conditioned medium from embryonic fibroblast feeder cells (CM). To understand the functions of Hand1, Mash2 and Gcm1 at a cellular level, we tested the effects of their ectopic and over-expression on the ability of TS cells to either continue to proliferate or differentiate into their alternative fates. Expression of Mash2 alone had no effects on TS cell differentiation. However, Mash2-transfected cells continued to divide longer after withdrawal of FGF/CM. Hand1 promoted TGC differentiation, even in the continued presence of FGF4/CM. Stra13, another bHLH factor gene that is expressed in TG cells, also induced TG differentiation. Gcm1 induced a rapid arrest of TS proliferation but, in contrast to Hand1 and Stra13, blocked TG cell differentiation. Although Gcm1 was not sufficient to promote SynT formation, expression of an antisense Gcm1 transcript blocked SynY differentiation. These data suggest that Mash2 functions to promote transient FGF4-independent amplification of trophoblast cells that are progressing towards the SpT and TG cell phenotype. By contrast, Hand1 and Stra13 promote cell cycle exit and restrict cells towards the TG fate, whereas Gcm1 promotes cell cycle exit and restriction towards the SynY fate. Keywords: Trophoblast cells; Cell cycle; Differentiation

Embryonic stem (ES) cells deficient in the enzyme poly(ADP-ribose) polymerase (Parp1) develop into teratocarcinoma-like tumors when injected subcutaneously into nude mice that contain cells with giant cell-like morphology. We show here that these cells express genes characteristic of trophoblast giant cells and thus belong to the trophectoderm lineage. In addition, Parp1-/- tumors contained other trophoblast subtypes as revealed by expression of spongiotrophoblast-specific marker genes. The extent of giant cell differentiation was enhanced, however, as compared with spongiotrophoblast. A similar shift toward trophoblast giant cell differentiation was observed in cultures of Parp1-deficient ES cells and in placentae of Parp1-/- embryos. Analysis of other cell lineage markers demonstrated that Parp1 acts exclusively in trophoblast to suppress differentiation. Surprisingly, trophoblast derivatives were also detected in wildtype tumors and cultured ES cells, albeit at significantly lower frequency. These data show that wildtype ES cells contain a small population of cells with trophectoderm potential and that absence of Parp1 renders ES cells more susceptible to adopting a trophoblast phenotype.

Mammalian embryos have an intimate relationship with their mothers, particularly with the placental vasculature from which embryos obtain nutrients essential for growth. It is an interesting vascular bed because maternal vessel number and diameter change dramatically during gestation and, in rodents and primates, the terminal blood space becomes lined by placental trophoblast cells rather than endothelial cells. Molecular genetic studies in mice aimed at identifying potential regulators of these processes have been hampered by lack of understanding of the anatomy of the vascular spaces in the placenta and the general nature of maternal--fetal vascular interactions. To address this problem, we examined the anatomy of the mouse placenta by preparing plastic vascular casts and serial histological sections of implantation sites from embryonic day (E) 10.5 to term. We found that each radial artery carrying maternal blood into the uterus branched into 5-10 dilated spiral arteries located within the metrial triangle, populated by uterine natural killer (uNK) cells, and the decidua basalis. The endothelial-lined spiral arteries converged together at the trophoblast giant cell layer and emptied into a few straight, trophoblast-lined 'canals' that carried maternal blood to the base of the placenta. Maternal blood then percolated back through the intervillous space of the labyrinth toward the maternal side of the placenta in a direction that is countercurrent to the direction of the fetal capillary blood flow. Trophoblast cells were found invading the uterus in two patterns. Large cells that expressed the trophoblast giant cell-specific gene Plf (encoding Proliferin) invaded during the early postimplantation period in a pattern tightly associated with spiral arteries. These peri/endovascular trophoblast were detected only ~150-300 [micro]m upstream of the main giant cell layer. A second type of widespread interstitial invasion in the decidua basalis by glycogen trophoblast cells was detected after E12.5. These cells did not express Plf, but rather expressed the spongiotrophoblast-specific gene Tpbp. Dilation of the spiral arteries was obvious between E10.5 and E14.5 and was associated with a lack of elastic lamina and smooth muscle cells. These features were apparent even in the metrial triangle, a site far away from the invading trophoblast cells. By contrast, the transition from endothelium-lined artery to trophoblast-lined (hemochorial) blood space was associated with trophoblast giant cells. Moreover, the shaping of the maternal blood spaces within the labyrinth was dependent on chorioallantoic morphogenesis and therefore disrupted in Gcm1 mutants. These studies provide important insights into how the fetoplacental unit interacts with the maternal intrauterine vascular system during pregnancy in mice. Key Words: labyrinth; mouse; placenta; pregnancy; spiral artery; trophoblast; umbilical artery; uterus; vascularization; vascular corrosion casts.

Terminal cell differentiation is usually associated with cell cycle exit. In some lineages, however, cells undergo continued rounds of DNA synthesis without intervening mitoses (endoreduplication) resulting in polyploid nuclei. This is striking in rodent trophoblast giant cells which contain up to 1000N of DNA. In Drosophila, the Escargot gene has been implicated in regulating the transition from mitotic cell cycles to endocycles during development. We found that a murine homologue, mSna, was expressed in mouse trophoblast and was downregulated during giant cell differentiation. The mSNA zinc finger protein bound to E-box DNA elements and, in transfected C3H10T1/2 fibroblasts, acted as a transcriptional repressor. The maximal repressive effect was dependent on both the zinc finger DNA-binding domain and the N-terminal, seven-amino-acid SNAG domain. Misexpression experiments in Rcho-1 trophoblast cells revealed that mSna regulates the transition from replicating precursor cells to committed giant cells: overexpression blocked, whereas antisense RNA-mediated underexpression promoted trophoblast giant cell differentiation. Overexpression of mSna in precursor cells had no effect on cell cycle kinetics, but did increase cyclin A and B levels, implying actions during G2. These effects were dependent on both the zinc finger and SNAG domains. Together, these data suggest that mSNA has an ESCARGOT-like function to repress the transcription of genes that promote the transition from mitotic to endoreduplicative cell cycles in rodent trophoblast.

Neonates regulate iron at birth and in early postnatal life. We reviewed literature from PubMed and Ovid Medline containing data on umbilical cord and venous blood concentrations of hepcidin and iron, and transferrin saturation (TSAT), in human neonates from 0 to 1 mo of age. Data from 59 studies were used to create reference ranges for hepcidin, iron, and TSAT for full-term-birth (FTB) neonates over the first month of life. In FTB neonates, venous hepcidin increases 100% over the first month of life (to reach 61.1 ng/mL; 95% CI: 20.1, 102.0 ng/mL) compared with umbilical cord blood (29.7 ng/mL; 95% CI: 21.1, 38.3 ng/mL). Cord blood has a high concentration of serum iron (28.4 μmol/L; 95% CI: 26.0, 31.1 μmol/L) and levels of TSAT (51.7%; 95% CI: 46.5%, 56.9%). After a short-lived immediate postnatal hypoferremia, iron and TSAT rebounded to approximately half the levels in the cord by the end of the first month. There were insufficient data to formulate reference ranges for preterm neonates. [ABSTRACT FROM AUTHOR]

Post-stroke depression is a depressive mood disorder that follows a cerebrovascular accident and is a burden on stroke patients. Its management is included in clinical practice guidelines focused on stroke, and the recommended treatment is selective serotonin reuptake inhibitors in conjunction with psychotherapy. Clinical practice guidelines are recommendations used to standardize best medical practice, but there is no current evaluation of guidelines containing post stroke depression recommendations. Thus, the objective is to appraise the selected guidelines manner of development and quality. A systematic literature review across three databases and a manual google search was performed to collect guidelines that included recommendations on the management of post-stroke depression. 1236 guidelines were screened, and 27 were considered for inclusion. Considered guidelines were manually reviewed by the authors, and ultimately, 7 met inclusion criteria. The appraisal of guidelines for research and evaluation was used to evaluate these guidelines' recommendations around post-stroke depression. Three guidelines met the threshold considered "High", with all of them having five or more quality domains eclipse the cutoff score of 70%. Across all guidelines, the highest scoring domains were "Scope and Purpose", "Clarity of Presentation", and "Editorial Independence" with scores of 76.98%, 73.81%, and 91.36% respectively. The lowest scoring domains were "Applicability", "Rigor of Development", and "Stakeholder Involvement" with respective scores of 58.73%, 54.02%, and 43.90%. The domains "Applicability", "Rigor of Development," and "Stakeholder Involvement" were the lowest scoring domains. These specific domains represent areas in which future guidelines could be more developed. [ABSTRACT FROM AUTHOR]

The basic helix-loop-helix transcription factor gene Hand1 has been implicated in development of the heart. However, the early lethality of Hand1-null mutant mouse embryos has precluded a precise understanding of its function. In this study, we have generated Hand1 homozygous mutant ES cells and performed in vitro differentiation experiments and chimeric analysis to study the role of Hand1 function during cardiac development. Hand1-null ES cells were able to differentiate into beating cardiomyocytes in vitro that expressed cardiac myosin and several cardiac-specific transcripts including Nkx2-5, [Alpha]-cardiac actin, and the myofilament genes myosin light chain 2a and 2v. In chimeras derived from Hand1-null ES cells and ROSA26 embryos, mutant cells were underrepresented in the left caudal region of the linear heart tube at E8.0. By E9.5, after cardiac looping, mutant cells were underrepresented in the anterior region of the outer curvature of the left ventricular myocardium, but did contribute to other parts of the left ventricle and to other cardiac chambers. These results imply that Hand1 is not essential for differentiation of ventricular cardiomyocytes. Hand1-null cells were also underrepresented in several other regions of later embryos, including the rhombencephalic neural tube that was associated with a deficiency of mutant cells in the neural crest cell-derived cardiac outflow tract and first branchial arch. In summary, Hand1 has cell-autonomous functions during cardiac morphogenesis in both mesodermal and neural crest derivatives. [C] 2000 Academic Press

Summary Many types of multinucleated cells (syncytia) generated by cell-cell fusion are post-mitotic, but it remains unclear how this state is maintained and why. Here, we utilized the fluorescent ubiquitination-based cell-cycle indicator (Fucci) reporter system to show that human placental trophoblast cells were all in the G0 phase before they fuse. Expression of the fusogenic protein (fusogen) Syncytin-2 was confined to G0 cells. Overexpression of Syncytin-2 in cycling cells overrode the cell-cycle restriction and enabled fusion of cells in the S/G2/M phases but resulted in the unstable syncytia retaining mitotic features. The Syncytin-2-induced syncytia were functionally compromised with respect to pathogen defense and hormone secretion. We found that, during trophoblast fusion, the cell-cycle inhibitor p21 interacted with the GCM1 transcription factor, and this complex bound to the promoter of Syncytin-2 and promoted its transcription. These findings demonstrate that G0-restricted Syncytin-2 expression is a prerequisite for development of functional post-mitotic syncytia. [ABSTRACT FROM AUTHOR]

A study was undertaken to investigate the biological activity of the mammalian Grb2, a subset of the SH2 domain-containing proteins of protein-tyrosine kinases, to relate it to the genetic analysis of an SH2/SH3 adaptor. The mammalian Grb2 was believed to bind phosphoproteins, docking proteins and cytoplasmic tyrosine kinases. Results revealed that Grb2 manifested multiple activities in normal and oncogenic signaling pathways. It was suggested that the Grb2 signaling pathway regulated cell differentiation in the early embryonic development.

The placenta forms a complex interface between the mother and fetus during development that is designed for efficient nutrient exchange. A large surface area is created by extensive branching morphogenesis of the trophoblast-derived epithelium to create a villous network, called the labyrinth in rodents. These villi are subsequently vascularized with an elaborate capillary network. Morphogenesis begins with selection of a subset of trophoblast cells in the basal layer of the chorion that express the Gcm1 transcription factor. These cells leave the cell cycle and undergo cell shape changes that initiate a process of involution to create primary villi into which fetal blood vessels grow. Much less is known about the regulation of subsequent events in branching, certainly compared with other organs. However, over 60 different mouse mutants have defects during later labyrinth development. Some of these mutant genes encode components of signaling pathways such as the fibroblast growth factor and Wnt pathways that play evolutionarily conserved roles in other branched organs, These mutants represent a still largely untapped resource as most of them have not been studied in detail in relation to placental morphogenesis. [ABSTRACT FROM AUTHOR]

Cholecystokinin (CCK). IS a vasodilator and prevents gastric injury from ethanol. Its effects against other irritants are unknown. This study was conducted to (1) assess whether CCK or oleate, a CCK secretagogue, could prevent gastric injury from other damaging agents and (2) examine the role of blood flow in CCK-induced gastroprotection. Conscious rats were pretreated for 10 minutes with intravenous saline solution or CCK (5 nrnol/kg) or were given 1 ml of orogastric water or oleate (100 mmol/L) 3 0 minutes before a 1 n-d orogastric bolus of acidified ethanol (150 mmol/L hydrochloric acid/50% ethanol), 0.75N hydrochloric acid, or 0.2N sodium hydroxide. Rats were killed 5 minutes after receiving an irritant and the total area (mm2) of macroscopic injury was quantified. The duration of CCK-induced gastroprotection against acidified ethanol was examined at 5,10,30, and 60 minutes after its administration. Other rats had gastric mucosal blood flow determined (fluorescent microspheres) at identical time points. CCK and oleate decreased gastric injury from all three luminal irritants. CCK-induced gastroprotection was present for 30 minutes but only enhanced gastric mucosal blood flow at 5 and 10 minutes. These data suggest that endogenous CCK may play a role in gastric mucosal defense and that blood flow alone does not fully explain CCK gastroprotection. [ABSTRACT FROM AUTHOR]

Dopamine and cholecystokinin have been colocalized in neurons and represent endogenous enteric neurotransmitters. Both peptides posses potent protective actions against gastric injury when given exogenously. This study was undertaken in conscious female rats to test the hypothesis that cholecystokinin may exert its protective actions via release of dopamine. Experiments were designed to ascertain whether l-dopa, a dopamine precursor, could prevent gastric injury with the same degree of efficacy as cholecystokinin and to determine what role alpha-2 adrenoreceptors and dopamine receptors play in mediating the protective actions of these peptides. Intraperitoneal administration of l-dopa (1 to 25 mg/kg) in a dose-dependent manner prevented the type of macroscopic injury to the acid-secreting portion of the stomach that is caused by 1 ml of orogastric acidified ethanol (150 mmol/L hydrochloric acid/50% ethanol), an effect corroborated by histologic examination. Administration of either the alpha-2 adrenoreceptor antagonist yohimbine (0.1 to 1.0 mg/kg) or the dopamine receptor antagonist haloperidol (1 to 5 mg/kg) caused a partial reversal of l-dopa-induced protection but not the protective actions of subcutaneous cholecystokinin (100 μg/kg). Simultaneous administration of both receptor antagonists had an additive effect and completely reversed the protective actions of l-dopa. The dopamine precursor l-dopa was just as effective in maintaining the integrity of the gastric epithelium in the face of a damaging insult as the gut peptide cholecystokinin. However, the data indicate that l-dopa initiates its protective actions through activation of both alpha-2 adrenoreceptors and dopamine receptors, whereas the protective effects of cholecystokinin are elicited by means of a different mechanism. [ABSTRACT FROM AUTHOR]

Although much progress is being made in understanding the molecular pathways in the placenta that are involved in the pathophysiology of pregnancy-related disorders, a significant gap exists in the utilization of this information for the development of new drug therapies to improve pregnancy outcome. On March 5-6, 2015, the Eunice Kennedy Shriver National Institute of Child Health and Human Development of the National Institutes of Health sponsored a 2-day workshop titled Placental Origins of Adverse Pregnancy Outcomes: Potential Molecular Targets to begin to address this gap. Particular emphasis was given to the identification of important molecular pathways that could serve as drug targets and the advantages and disadvantages of targeting these particular pathways. This article is a summary of the proceedings of that workshop. A broad number of topics were covered that ranged from basic placental biology to clinical trials. This included research in the basic biology of placentation, such as trophoblast migration and spiral artery remodeling, and trophoblast sensing and response to infectious and noninfectious agents. Research findings in these areas will be critical for the formulation of the development of future treatments and the development of therapies for the prevention of a number of pregnancy disorders of placental origin that include preeclampsia, fetal growth restriction, and uterine inflammation. Research was also presented that summarized ongoing clinical efforts in the United States and in Europe that has tested novel interventions for preeclampsia and fetal growth restriction, including agents such as oral arginine supplementation, sildenafil, pravastatin, gene therapy with virally delivered vascular endothelial growth factor, and oxygen supplementation therapy. Strategies were also proposed to improve fetal growth by the enhancement of nutrient transport to the fetus by modulation of their placental transporters and the targeting of placental mitochondrial dysfunction and oxidative stress to improve placental health. The roles of microRNAs and placental-derived exosomes, as well as messenger RNAs, were also discussed in the context of their use for diagnostics and as drug targets. The workshop discussed the aspect of safety and pharmacokinetic profiles of potential existing and new therapeutics that will need to be determined, especially in the context of the unique pharmacokinetic properties of pregnancy and the hurdles and pitfalls of the translation of research findings into practice. The workshop also discussed novel methods of drug delivery and targeting during pregnancy with the use of macromolecular carriers, such as nanoparticles and biopolymers, to minimize placental drug transfer and hence fetal drug exposure. In closing, a major theme that developed from the workshop was that the scientific community must change their thinking of the pregnant woman and her fetus as a vulnerable patient population for which drug development should be avoided, but rather be thought of as a deprived population in need of more effective therapeutic interventions. [ABSTRACT FROM AUTHOR]

Abstract: This qualitative study examined reported barriers to consuming a healthy diet and engaging in regular physical activity among low-income families with existing issues of overweight or obesity. Parents and health professionals reported that issues of access, availability and cost were perceived as major barriers to a healthy lifestyle along with familial shape, metabolism and safety. Many felt their diet and activity levels were already good. The study concluded that improving access, availability and income may increase activity but only in some groups. Issues of perceived helplessness (genetics/metabolism) and high optimistic bias may provide rationalisations that undermine behaviour change. Together these issues may mask the more complex, less easily articulated influences (cultural, social and family influences and practices, knowledge and skill levels, and emotional status) that lead to unhealthy behaviours. [Copyright &y& Elsevier]

Abstract: Background: Early efforts to predict death following severe burns focused on age and burn size; more recent work incorporated inhalation injury and pneumonia. Gender, co-morbid illness, and co-existent trauma have been implicated in burn mortality but have rarely been incorporated into predictive models. Methods: The National Burn Repository (NBR) and the National Trauma Data Bank (NTDB) provided data on 68,661 (54,219 and 14,442, respectively) burn patients that was used to develop and validate, respectively, a predictive model of burn mortality. Logistic regression was used to model the odds of mortality with respect to age, gender, % body surface area burned (BSAB), co-existent trauma, inhalation injury, pneumonia, and co-morbid illness. Performance of the predictive model was assessed using a deviance statistic, receiver operating characteristic (ROC) curves, and the Hosmer-Lemeshow (HL) statistic. Results: The predictive model that demonstrated optimal performance included the variables age, percent total BSAB, inhalation injury, co-existent trauma, and pneumonia. The area under the ROC curve for this model was 0.94 and the HL statistic was 16.0. The inclusion of additional variables, i.e., gender, co-morbid illness, did not improve the performance of the model despite reduction in the model deviance. When the predictive model was applied to the validation data source, the area under the ROC curve was 0.87 and the HL statistic was 10.0, indicating good discrimination and calibration. Conclusion: The results of this study suggest that a comprehensive predictive model of burn mortality incorporating certain variables not previously considered in other models provides superior predictive ability. [Copyright &y& Elsevier]

Abstract: Background: Epidemiologic research on intentional burns in the United States has mainly been based on small, geographically restricted populations. The current study presents the descriptive epidemiology of intentional burns using data from a large, geographically diverse population of burn patients. Methods: The National Burn Repository (NBR) was queried for patients with intentional burns and analyzed data pertaining to their demographic and medical characteristics; primarily comparing the prevalence proportions of these variables according to specific injury intent. Results: From a total of 54,219 burn patients, 1601 patients who sustained intentional burns were identified; 49% were self-inflicted, and 51% were assault-related. Compared to all other burn patients, intentional burn patients had a larger mean total body surface area (TBSA) burned (22.0% versus 11.3%, p <0.0001), longer hospital stay (19.8 days versus 12.5 days, p <0.0001), and higher mortality (13.9% versus 2.5%, p <0.0001). Self-inflicted compared to assault-related burns were associated with a larger TBSA burned (27.5% versus 16.8%, p <0.0001) and higher mortality (20.8% versus 7.2%, p <0.0001). Conclusions: Data from this national cohort of burn patients support findings from smaller studies that patients who suffer intentional burns experience excess morbidity and mortality. [Copyright &y& Elsevier]

The bHLH transcription factor, Hand1 has been implicated in cardiac looping in the mouse, however its function in the developing heart remains unknown. To investigate the mechanism(s) through which Hand1 might function, we screened for potential downstream target genes using representational difference analysis. Thymosin β4 was found to be down-regulated whereas cystatin C and αCA were up-regulated in Hand1-null embryoid bodies. Whole-mount in situ hybridisation on wild type embryos (E8.0–E10.5) and Hand1 homozygous-mutant embryos (E8.0) confirmed co-expression of the putative targets with Hand1 in the heart and their aberrant expression in a Hand1-null background. [Copyright &y& Elsevier]

Age-related muscle loss (sarcopenia) is a major clinical problem affecting both men and women – accompanied by muscle weakness, dysfunction, disability, and impaired quality of life. Current definitions of sarcopenia do not fully encompass the age-related changes in skeletal muscle. We therefore examined the influence of aging and sex on elements of skeletal muscle health using a thorough histopathological analysis of myocellular aging and assessments of neuromuscular performance. Two-hundred and twenty-one untrained males and females were separated into four age cohorts [mean age 25 y ( n  = 47), 37 y ( n  = 79), 61 y ( n  = 51), and 72 y ( n  = 44)]. Total (−12%), leg (−17%), and arm (−21%) lean mass were lower in both 61 y and 72 y than in 25 y or 37 y ( P  < 0.05). Knee extensor strength (−34%) and power (−43%) were lower ( P  < 0.05) in the older two groups, and explosive sit-to-stand power was lower by 37 y ( P  < 0.05). At the histological/myocellular level, type IIx atrophy was noted by 37 y and type IIa atrophy by 61 y ( P  < 0.05). These effects were driven by females, noted by substantial and progressive type IIa and IIx atrophy across age. Aged female muscle displayed greater within-type myofiber size heterogeneity and marked type I myofiber grouping (~5-fold greater) compared to males. These findings suggest the predominant mechanisms leading to whole muscle atrophy differ between aging males and females: myofiber atrophy in females vs. myofiber loss in males. Future studies will be important to better understand the mechanisms underlying sex differences in myocellular aging and optimize exercise prescriptions and adjunctive treatments to mitigate or reverse age-related changes. [ABSTRACT FROM AUTHOR]

Rational: There has been increased focus on hemostatic potential and function in the initial assessment of the patient with traumatic injuries, that not been extensively studied in patients with burns. We proposed to determine the hemostatic potential of patients with burns upon admission to the emergency department and contrasted their condition with that of healthy controls and patients with other traumatic injuries. In addition we assessed differences due to thermal versus electrical injury and evaluated the effect of burn size.Methods: This is a patient based prospective observational study conducted with delayed consented. Subjects at the highest level of trauma activation upon admission to the ED had a blood sample collected for research purposes and were subsequently consented. Hemostatic potential was measured by rapid thromelastography (r-TEG®), thrombin generation by calibrated automated thrombogram (CAT) and platelet function by Multiplate® using five activators. Burn subjects were compared to subjects with other traumatic injuries and controls. Within the burn subjects additional analysis compared mechanism (thermal vs. electrical) and burn size. Values are medians (IQR).Results: Two hundred and eighty two trauma patients (with burns n=40, 14%) and 27 controls were enrolled. Upon admission, compared to controls, subjects with burns or trauma were hyper-coagulable based on r-TEG and CAT, with increased rates of clot formation and thrombin generation. There were no differences in burns compared to other traumatic injuries. The presence of hyper-coagulation did not appear to be related to the type of burn or the percentage of total body surface area involved. Employing previous defined cut points for R-TEG driven therapeutic interventions burn patients had similar rates of hyper- and hypo-coagulation noted in patients with traumatic injuries.Conclusion: Upon admission patients with burns are in a hyper-coagulable state similar to that of other trauma patients. Employing demonstrated cut points of hemostatic potential in trauma patients associated with increased risk of poor outcomes demonstrated the incidence in burn patients to be similar, suggesting that these values could be used in the early assessment of the patient with burns to guide treatment interventions. [ABSTRACT FROM AUTHOR]