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A cis-regulatory genetic element which targets gene expression to stem cells, termed stem cell enhancer, serves as a molecular handle for stem cell-specific genetic engineering. Here we show the generation and characterization of a tamoxifen-inducible CreERT2 transgenic (Tg) mouse employing previously identified hematopoietic stem cell (HSC) enhancer for Runx1, eR1 (+24 m). Kinetic analysis of labeled cells after tamoxifen injection and transplantation assays revealed that eR1-driven CreERT2 activity marks dormant adult HSCs which slowly but steadily contribute to unperturbed hematopoiesis. Fetal and child HSCs that are uniformly or intermediately active were also efficiently targeted. Notably, a gene ablation at distinct developmental stages, enabled by this system, resulted in different phenotypes. Similarly, an oncogenic Kras induction at distinct ages caused different spectrums of malignant diseases. These results demonstrate that the eR1-CreERT2 Tg mouse serves as a powerful resource for the analyses of both normal and malignant HSCs at all developmental stages.

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We search for a first-order phase transition gravitational wave signal in 45 pulsars from the NANOGrav 12.5-year dataset. We find that the data can be modeled in terms of a strong first order phase transition taking place at temperatures below the electroweak scale. However, we do not observe any strong preference for a phase-transition interpretation of the signal over the standard astrophysical interpretation in terms of supermassive black hole mergers; but we expect to gain additional discriminating power with future datasets, improving the signal to noise ratio and extending the sensitivity window to lower frequencies. An interesting open question is how well gravitational wave observatories could separate such signals.

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BACKGROUND: The Burden of Treatment Questionnaire (TBQ) assesses the impact of a patient's treatment workload on their quality of life. OBJECTIVES: The aim was to translate and validate the TBQ on Chinese primary care patients with multi-morbidity. METHODS: The English TBQ was translated and back-translated using professional translators. Cognitive debriefing interviews were performed on 15 patients. The resulting instrument was tested on 200 primary care patients with multi-morbidity (>1 chronic disease) to examine its psychometric performance including exploratory factor analysis, confirmatory factor analysis, internal consistency and reliability. The EuroQol Five-Dimension Five-Level Questionnaire (EQ-5D-5L), Short-Form Six-Dimension (SF-6D), WONCA COOP Charts and the Global Health Rating Scale were used to assess convergent and divergent validity. RESULTS: Median age of the respondents was 62 years (range 22-95 years) with a median of four conditions. The median TBQ total score was 16 (interquartile range 7.25-30). There was a significant floor effect (>15%) observed for all items. Spearman's correlations was >0.4 for all items demonstrating adequate internal construct validity. TBQ global score correlated with number of conditions (P = 0.034), EQ-5D-5L (P < 0.001), SF-6D (P < 0.001) and the feelings (P = 0.004), daily activities (P = 0.003) and social activities (P < 0.001) domains of the WONCA COOP. There was no significant correlation between global health rating and TBQ global scores (P = 0.298). Factor analysis demonstrated a three-factor structure. There was good internal consistency (Cronbach's alpha = 0.842) and good test-retest reliability (intra-class correlation coefficient = 0.830). CONCLUSION: The newly translated Chinese version of the TBQ appears to be valid and reliable for use in Cantonese-speaking, adult primary care patients with multi-morbidity.

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There has been considerable interest in identifying a cis-regulatory element that targets gene expression to stem cells. Such an element, termed stem cell enhancer, holds the promise of providing important insights into the transcriptional programs responsible for inherent stem cell-specific properties such as self-renewal capacity. The element also serves as a molecular handle for stem cell-specific marking, transgenesis and gene targeting, thereby becoming invaluable to stem cell research. A series of candidate enhancers have been identified for hematopoietic stem cells (HSCs). This review summarizes currently known HSC enhancers with emphasis on an intronic enhancer in the Runx1 gene which is essential for the generation and maintenance of HSCs. The element, named eR1 (+24m), is active specifically in HSCs, but not in progenitors, and is hence the most definitive HSC enhancer.

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Hematopoietic cell clusters associated with the midgestation mouse aorta, umbilical and vitelline arteries play a pivotal role in the formation of the adult blood system. Both genetic and live-imaging data indicate that definitive hematopoietic progenitor/stem cells (visualized as clusters) are generated from hemogenic endothelium. A 3-dimensional (3-D) whole embryo immunostaining and imaging technique has allowed quantitation and cartographic mapping of intravascular hematopoietic clusters. During this period the vitelline artery is most extensively remodeled, and several reports have suggested that vitelline remodeling leads to extravascular hematopoietic cluster emergence. Whether the earliest definitive progenitors/stem cells are intra or extra vascular could influence the process by which these cells migrate to the next hematopoietic territory, the fetal liver. Hence, by 3-D imaging we more closely examined hematopoietic clusters in the vitelline and associated connected small vessels and show here that hematopoietic clusters (particularly large clusters) are intravascular during the period of vascular remodeling.

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Runx1 is essential for the generation of hematopoietic stem cells (HSCs) and is frequently mutated in human leukemias. However, the cis-regulatory mechanisms modulating the Runx1 gene expression remain to be elucidated. Herewith, we report the identification of an intronic Runx1 enhancer, Runx1 +24 mouse conserved noncoding element (mCNE), using a combinatorial in silico approach involving comparative genomics and retroviral integration sites mapping. The Runx1 +24 mCNE was found to possess hematopoietic-specific enhancer activity in both zebrafish and mouse models. Significantly, this enhancer is active specifically in hemogenic endothelial cells (ECs) at sites where the de novo generation of HSCs occurs. The activity of this enhancer is also strictly restricted to HSCs within the hematopoietic compartment of the adult bone marrow. We anticipate that Runx1 +24 mCNE HSC enhancer will serve as a molecular handle for tracing and/or manipulating hemogenic ECs/HSCs behavior in vivo, and consequently become an invaluable tool for research on stem cell and cancer biology.

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Transcription in multicellular eukaryotic organisms involves an elaborate orchestration of the core promoter and cis-regulatory elements to drive spatiotemporally and quantitatively correct gene expression. Unlike promoters found immediately upstream of protein-coding genes, the positions of distally located cis-regulatory elements relative to a gene of interest are difficult to define. As such, the identification and characterization of these regulatory elements has proved to be challenging. To this end, we propose a combinatorial in silico approach involving retroviral integration sites (RIS) mapping together with predicted matrix attachment regions (MARs) mapping and an already well-established comparative genomics approach, to enhance the prediction of potential cis-regulatory elements. Predicted elements can be validated by further investigations to ascertain their functions. In view of the abundance of electronically available RIS information, RIS mapping has an unrealized potential to aid in the discovery of novel cis-regulatory elements.

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Automated peritoneal dialysis (APD) benefits children on dialysis and their parents by allowing for more daytime freedom and a more normal life. We carried out a survey on health-related quality of life (HRQOL) in children and adolescents from our end-stage renal disease program, including those on APD and hemodialysis (HD), and those who had received a kidney transplant (TX). Parents of patients under 18 years of age were also interviewed. The questionnaire on QOL was adapted from the Pediatric Quality of Life Inventory and grouped into seven aspects for which patients and parents were asked to assess the frequency of related problems during the preceding 3 months. We surveyed eligible children among the APD, HD, and TX patients enrolled in our program, and we surveyed the parents of the patients under 18 years of age. For APD, patients and parents both gave their most favorable scores to the peer activities and relationships and family activities and relationships aspects. In the TX group, the family activities and relationships aspect was also scored most favorably of all aspects. Notably, we observed no significant difference between the total scores for the APD and TX groups among patients and parents alike. Although the survey provided only a "snapshot" of HRQOL, the assessment by APD patients and their parents seems to be comparable to that by TX patients and their parents.

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AIMS: To study the prevalence of disordered eating attitudes and behaviours among adolescents in Hong Kong and to examine the socio-demographic and behavioural correlates. METHODS: Three secondary schools with different academic performance were selected from the Eastern District of Hong Kong. A total of 2382 students enrolled in Forms 1-7 at the three schools completed a specially designed questionnaire. The questionnaire contained questions on socio-demographic information, body weight satisfaction, exposure to mass media, health behaviours as well as the Eating Attitudes Test - 26 (EAT-26). Data were analysed using Student's t-test, chi2 analysis and multivariate logistic regression models. RESULTS: Disordered eating (EAT score > or =20) was present in 52 (3.9%) adolescent boys and 68 (6.5%) adolescent girls. The youngest case was only 11 years old. A high degree of body weight dissatisfaction was shared by our adolescents. Teenage girls, overweight youths and those with poor academic performance were at increased risk of having disordered eating. Strong associations were found between disordered eating and other health-compromising behaviours including smoking, alcohol and soft drug use, delinquent behaviours, suicidal ideation and self-harm behaviours. Exposure to entertainment, beauty and youth magazines was positively related to disordered eating. CONCLUSIONS: Disordered eating is prevalent among adolescents in Hong Kong. It remains a significant public health challenge to our community. Prevention programmes targeting youths at the greatest risk should be considered.

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The Runx family genes are involved in hematopoiesis, osteogenesis and neuropoiesis, and mutations in these genes have been frequently associated with human hereditary diseases and cancers. Here we report the cDNA cloning of the full Runx gene family of the pufferfish (Fugu rubripes), which comprises frRunx1, frRunx2, frRunx3, frRunt and frCbfb. Fugu is evolutionarily distant from mammals, thus the annotation of the frRunx family genes greatly facilitates comparative genomics approaches. Protein sequence comparison revealed that the fugu genes show high conservation in the Runt domain and PY and VWRPY motifs. frRunx1 had an extra stretch of eight histidine residues, while frRunx2 lacked the poly-glutamine/-alanine stretch that is a hallmark of the mammalian Runx2 genes. Analysis of the promoter regions revealed high conservation of the binding sites for transcription factors, including Runx sites in the P1 promoters. Abundant CpG dinucleotides in the P2 promoter regions were also detected. The expression patterns of the frRunx family genes in various tissues showed high similarity to those of the mammalian Runx genes. The genomic structures of the fugu and mammalian Runx genes are largely conserved except for a split exon 2 in frRunx1 and an extra exon in the C-terminal region of frRunx3 that is missing in mammalian Runx3 genes. The similarities and differences between the Runx family genes of fugu and mammals will improve our understanding of the functions of these proteins.

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The objective of this multicenter randomized controlled trial was to compare the efficacy of enuresis alarms, oral desmopressin, and combined treatment in Chinese children with monosymptomatic primary nocturnal enuresis. We assigned 105 children aged 7-15 years to receive alarms (group 1, 35 patients), oral desmopressin 400 mug (group 2, 38 patients), or combined therapy (group 3, 32 patients) for 12 weeks; patients were then followed for 12 weeks after treatment. The wetting frequency decreased during treatment by 46%, 52%, and 73% in groups 1, 2, and 3, respectively. In groups 2 and 3, but not in group 1, there was rebound post treatment, but significant improvements persisted at 12 weeks. The complete and partial response rates were 22.9% and 20%, respectively in group 1, 42% and 10.5% in group 2, and 62.5% and 15.6% in group 3. By Kaplan-Meier analysis, group 1 had a significantly poorer response than groups 2 and 3. Of the responders, 20%, 60%, and 40% in groups 1, 2, and 3, respectively, relapsed after stopping treatment. In conclusion, enuresis alarms and/or oral desmopressin were less efficacious in Chinese than in Western societies. Desmopressin produced an immediate effect but relapses were common. Alarms took several weeks to produce a benefit, which was persistent on follow-up.

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The longest central nervous system (CNS) specific isoform of the major myelin-associated inhibitor of neurite growth, Nogo-A, has previously been shown to be expressed largely in oligodendrocytes. Using an antibody raised against a recombinant fusion protein comprising amino acids 223-399 of Nogo-A, we show in this report that Nogo-A is also expressed in the cell body of a distinct set of CNS neurons. The antibody detects a single protein band of 220 kDa in rat brain lysate and neuroblastoma cell lysates. Immunofluorescent analyses reveal that Nogo-A is found largely in the endoplasmic reticulum of neuroblastoma cell lines SH-SY5Y and NIE-115. In the mouse CNS, Nogo-A can be found in specific subsets of neuronal cell bodies in addition to oligodendrocytes, but not glial fibrillary associated protein positive astrocytes or MAC-1 positive microglia. Our results provide a conclusive demonstration of the expression of Nogo-A in CNS neurons, which suggests that Nogo-A may have distinct endogenous roles in neurons other than its known ability to inhibit neurite growth.

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The recently cloned gene Nogo, whose alternative splice products correspond to the antigenic target of the central nervous system (CNS) regeneration enhancing monoclonal antibody IN-1, codes for membrane proteins enriched in brain, particularly in oligodendrocytes. The 66-amino acid extracellular domain of Nogo (Nogo-66) interacts with a high-affinity receptor (NgR), a glycosylphosphatidylinositol (GPI)-linked protein with multiple leucine-rich repeats. The amino terminal cytoplasmic domain of Nogo appears to have a general cellular growth inhibitory effect. Nogo-66, on the other hand, specifically retards neurite outgrowth and induces growth cone collapse, possibly through its interaction with NgR and as yet unidentified transmembrane coreceptors. Recent results also suggest that Nogo expression may induce apoptosis in tumor cells. Together, these proteins provide new molecular handles for the design of therapeutic interventions for CNS injuries and neurodegenerative diseases, as well as possible leads to anticancer strategies.

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