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1.  Tbx1 is required for second heart field proliferation in zebrafish 
The mammalian outflow tract (OFT) and primitive right ventricle arise by accretion of newly differentiated cells to the arterial pole of the heart tube from multi-potent progenitor cells of the second heart field (SHF). While mounting evidence suggests that the genetic pathways regulating SHF development are highly conserved in zebrafish, this topic remains an active area of investigation.
Here, we extend previous observations demonstrating that zebrafish tbx1 (van gogh, vgo) mutants show conotruncal defects consistent with a conserved role in SHF-mediated cardiogenesis. Surprisingly, we reveal through double in situ analyses that tbx1 transcripts are excluded from cardiac progenitor cells or differentiated cardiomyocytes, suggesting a non-autonomous role in SHF development. Further, we find that the diminuitive ventricle in vgo animals results from a 25% decrease in cardiomyocyte numbers that occurs subseqent to heart tube stages. Lastly, we report that although SHF progenitors are specified in the absence of Tbx1, they fail to be maintained due to compromised SHF progenitor cell proliferation.
These studies highlight conservation of the Tbx1 program in zebrafish SHF biology.
PMCID: PMC3676967  PMID: 23335360
tbx1; zebrafish; heart; second heart field; cardiac
2.  Heart field origin of great vessel precursors relies on nkx2.5-mediated vasculogenesis 
Nature cell biology  2013;15(11):10.1038/ncb2862.
The pharyngeal arch arteries (PAAs) are transient embryonic blood vessels that make indispensable contributions to the carotid arteries and great vessels of the heart, including the aorta and pulmonary artery1, 2. During embryogenesis, the PAAs appear in a craniocaudal sequence to connect pre-existing segments of the primitive circulation after de novo vasculogenic assembly from angioblast precursors3, 4. Despite the unique spatiotemporal characteristics of PAA development, the embryonic origins of PAA angioblasts and the genetic factors regulating their emergence remain unknown. Here, we identify the embryonic source of PAA endothelium as nkx2.5+ progenitors in lateral plate mesoderm long considered to adopt cell fates within the heart exclusively5, 6. Further, we report that PAA endothelial differentiation relies on Nkx2.5, a canonical cardiac transcription factor not previously implicated in blood vessel formation. Together, these studies reveal the heart field origin of PAA endothelium and attribute a novel vasculogenic function to the cardiac transcription factor nkx2.5 during great vessel precursor development.
PMCID: PMC3864813  PMID: 24161929
3.  Latent TGFβ binding protein 3 identifies a second heart field in zebrafish 
Nature  2011;474(7353):645-648.
The four-chambered mammalian heart develops from two fields of cardiac progenitor cells (CPCs) distinguished by their spatiotemporal patterns of differentiation and contributions to the definitive heart [1–3]. The first heart field differentiates earlier in lateral plate mesoderm, generates the linear heart tube and ultimately gives rise to the left ventricle. The second heart field (SHF) differentiates later in pharyngeal mesoderm, elongates the heart tube, and gives rise to the outflow tract (OFT) and much of the right ventricle. Because hearts in lower vertebrates contain a rudimentary OFT but not a right ventricle [4], the existence and function of SHF-like cells in these species has remained a topic of speculation [4–10]. Here we provide direct evidence from Cre/Lox-mediated lineage tracing and loss of function studies in zebrafish, a lower vertebrate with a single ventricle, that latent-TGFβ binding protein 3 (ltbp3) transcripts mark a field of CPCs with defining characteristics of the anterior SHF in mammals. Specifically, ltbp3+ cells differentiate in pharyngeal mesoderm after formation of the heart tube, elongate the heart tube at the outflow pole, and give rise to three cardiovascular lineages in the OFT and myocardium in the distal ventricle. In addition to expressing Ltbp3, a protein that regulates the bioavailability of TGFβ ligands [11], zebrafish SHF cells co-express nkx2.5, an evolutionarily conserved marker of CPCs in both fields [4]. Embryos devoid of ltbp3 lack the same cardiac structures derived from ltbp3+ cells due to compromised progenitor proliferation. Additionally, small-molecule inhibition of TGFβ signaling phenocopies the ltbp3-morphant phenotype whereas expression of a constitutively active TGFβ type I receptor rescues it. Taken together, our findings uncover a requirement for ltbp3-TGFβ signaling during zebrafish SHF development, a process that serves to enlarge the single ventricular chamber in this species.
PMCID: PMC3319150  PMID: 21623370
4.  Gene mutations and increased levels of p53 protein in human squamous cell carcinomas and their cell lines. 
British Journal of Cancer  1993;67(6):1274-1284.
Using immunocytochemical and Western blotting techniques we have demonstrated the presence of abnormally high levels of p53 protein in 8/24 (33%) of human squamous cell carcinomas (SCC) and 9/18 (50%) of SCC cell lines. There was a correlation between the immunocytochemical results obtained with eight SCC samples and their corresponding cell lines. Direct sequencing of PCR-amplified, reverse transcribed, p53 mRNA confirmed the expression of point mutations in six of the positive cell lines and detected in-frame deletions in two others. We also detected two stop mutations and three out-of-frame deletions in five lines which did not express elevated levels of p53 protein. Several of the mutations found in SCC of the tongue (3/7) were in a region (codons 144-166) previously identified as being a p53 mutational hot spot in non-small cell lung tumours (Mitsudomi et al., 1992). In 11/13 cases only the mutant alleles were expressed suggesting loss or reduced expression of the wild type alleles in these cases. Six of the mutations were also detected in the SCCs from which the lines were derived, strongly suggesting that the mutations occurred, and were selected, in vivo. The 12th mutation GTG-->GGG (valine-->glycine) at codon 216 was expressed in line SCC-12 clone B along with an apparently normal p53 allele and is to our knowledge a novel mutation. Line BICR-19 also expressed a normal p53 allele in addition to one where exon 10 was deleted. Additionally 15 of the SCC lines (including all of those which did not show elevated p53 protein levels) were screened for the presence of human papillomavirus types 16 and 18 and were found to be negative. These results are discussed in relation to the pathogenesis of SCC and the immortalisation of human keratinocytes in vitro.
PMCID: PMC1968513  PMID: 8390283
6.  Natural Compounds as Potential Treatments of NF2-Deficient Schwannoma and Meningioma: Cucurbitacin D and Goyazensolide 
Cucurbitacin D and goyazensolide, two plant-derived natural compounds, possess potent growth-inhibitory activity in schwannoma and meningioma cells.
Currently, no FDA-approved drugs are available for neurofibromatosis type 2 (NF2)-associated schwannomas and meningiomas. Selected natural compounds with antineoplastic activity, such as cucurbitacin and goyazensolide, may be developed as potential treatments for these tumors.
The Nf2-deficient mouse schwannoma Sch10545 and human benign meningioma Ben-Men-1 cells were treated with various concentrations of cucurbitacin D and goyazensolide. The effect on cell proliferation was determined using resazurin assays. Flow cytometry was used to assess the cell cycle profiles. Western blot analysis was performed to investigate the expression of various signal molecules related to the cell cycle and the AKT pathway.
Cucurbitacin D inhibited proliferation of Sch10545 cells (IC50 ~0.75 μM) and Ben-Men-1 cells (IC50 ~0.2 μM). Goyazensolide also reduced cell proliferation of Sch10545 cells (IC50 ~0.9 μM) and Ben-Men-1 cells (IC50 ~1 μM). The G2/M population increased in both Sch10545 and Ben-Men-1 cells treated with cucurbitacin D or goyazensolide around the IC50. Cucurbitacin and goyazensolide substantially reduced the levels of cyclins E and A in treated Sch10545 and Ben-Men-1 cells. Cucurbitacin D also inhibited cyclin B, phospho-AKT and phospho-PRAS40 expression. In addition, goyazensolide reduced the levels of phospho-AKT and NFκB and increased the expression of pro-apoptotic Bim in Sch10545 and Ben-Men-1 cells.
Both cucurbitacin D and goyazensolide effectively inhibit proliferation of NF2-deficient schwannoma and meningioma cells, suggesting that these natural compounds should be further evaluated as potential treatments for NF2-related tumors.
PMCID: PMC4334125  PMID: 23928514
Natural compounds; vestibular schwannoma; meningioma; neurofibromatosis type 2 (NF2); cucurbitacin D; goyazensolide
7.  Mechanisms of homologous and heterologous phosphorylation of FFA receptor 4 (GPR120): GRK6 and PKC mediate phosphorylation of Thr347, Ser350, and Ser357 in the C-terminal tail 
Biochemical pharmacology  2014;87(4):650-659.
Free fatty acid receptor 4 (FFA4), previously known as GPR120, is a G protein-coupled receptor that promotes numerous anti-inflammatory and antidiabetic effects upon its agonism by long chained unsaturated fatty acids. We have previously demonstrated that agonism of FFA4 with docosahexaenoic acid (DHA) and alpha-linoleic acid (ALA) facilitates rapid and transient phosphorylation of FFA4 expressed ectopically on the surface of HEK293 cells. However, the precise mechanisms that promote FFA4 phosphorylation remain elusive. In the current study, we examined the mechanisms behind both heterologous and homologous phosphorylation of FFA4 and set out to identify the foci of FFA4 phosphorylation. Our results demonstrate that basal and heterologous phosphorylation of FFA4 are mediated by protein kinase C (PKC), while G protein-coupled receptor kinase 6 (GRK6) plays the predominant role in DHA-mediated phosphorylation of FFA4. Furthermore, we identify Thr347, Ser350, and Ser357 in the C-terminal tail as major sites of FFA4 phosphorylation. Concurrent mutation of these three sites leads to a FFA4 receptor that seemingly affects Gαq/11 signaling in a positive manner as demonstrated by heightened intracellular Ca+2 responses following agonism with DHA. Importantly, this phosphodefective FFA4 mutant lacked the ability to promote β -arrestin-2 recruitment to the cell membrane. Since many of the functionally beneficial physiological effects of FFA4 are noted to be β -arrestin mediated, these findings could provide insight into the structural requirements for FFA4 function.
PMCID: PMC3959902  PMID: 24412271
8.  High expression of the stem cell marker nestin is an adverse prognostic factor in WHO grade II-III astrocytomas and oligoastrocytomas 
Journal of neuro-oncology  2014;117(1):183-189.
Infiltrating astrocytomas and oligoastrocytomas of low to anaplastic grade (WHO grades II and III), in spite of being associated with a wide range of clinical outcomes, can be difficult to subclassify and grade by the current histopathologic criteria. Unlike oligodendrogliomas and anaplastic oligodendrogliomas that can be identified by the 1p/19q codeletion and the more malignant glioblastomas (WHO grade IV astrocytomas) that can be diagnosed solely based on objective features on routine hematoxylin and eosin sections, no such objective criteria exist for the subclassification of grade II-III astrocytomas and oligoastrocytomas (A+OA II-III). In this study, we evaluated the prognostic and predictive value of the stem cell marker nestin in adult A+OA II-III (n=50) using immunohistochemistry and computer-assisted analysis on tissue microarrays. In addition, the correlation between nestin mRNA level and total survival was analyzed in the NCI Rembrandt database. The results showed that high nestin expression is a strong adverse prognostic factor for total survival (p=0.0004). The strength of the correlation was comparable to but independent of the isocitrate dehydrogenase 1/2 (IDH 1/2) mutation status. Histopathological grading and subclassification did not correlate significantly with outcome, although the interpretation of this finding is limited by the fact that grade III tumors were treated more aggressively than grade II tumors. These results suggest that nestin level and IDH 1/2 mutation status are strong prognostic features in A+OA II-III and possibly more helpful for treatment planning than routine histopathological variables such as oligodendroglial component (astrocytoma vs. oligoastrocytoma) and WHO grade (grade II vs. III).
PMCID: PMC4326086  PMID: 24519516
mixed glioma; outcome; prognosis; progression-free survival; low-grade gliomas; anaplastic gliomas
9.  A Simple Litmus Test for Aldehyde Oxidase Metabolism of Heteroarenes 
Journal of Medicinal Chemistry  2014;57(4):1616-1620.
The bioavailability of aromatic azaheterocyclic drugs can be affected by the activity of aldehyde oxidase (AO). Susceptibility to AO metabolism is difficult to predict computationally and can be complicated in vivo by differences between species. Here we report the use of bis(((difluoromethyl)sulfinyl)oxy)zinc (DFMS) as a source of CF2H radical for a rapid and inexpensive chemical “litmus test” for the early identification of heteroaromatic drug candidates that have a high probability of metabolism by AO.
PMCID: PMC3983350  PMID: 24472070
10.  HSP90 Inhibition Suppresses Lipopolysaccharide-Induced Lung Inflammation In Vivo 
PLoS ONE  2015;10(1):e0114975.
Inflammation is an important component of cancer diathesis and treatment-refractory inflammation is a feature of many chronic degenerative lung diseases. HSP90 is a 90kDa protein which functions as an ATP-dependent molecular chaperone that regulates the signalling conformation and expression of multiple protein client proteins especially oncogenic mediators. HSP90 inhibitors are in clinical development as cancer therapies but the myeleosuppressive and neutropenic effect of first generation geldanamycin-class inhibitors has confounded studies on the effects on HSP90 inhibitors on inflammation. To address this we assessed the ability of Ganetespib, a non-geldanamycin HSP90 blocker, to suppress lipopolysaccharide (LPS)-induced cellular infiltrates, proteases and inflammatory mediator and transcriptional profiles. Ganetespib (10–100mg/kg, i.v.) did not directly cause myelosuppression, as assessed by video micrography and basal blood cell count, but it strongly and dose-dependently suppressed LPS-induced neutrophil mobilization into blood and neutrophil- and mononuclear cell-rich steroid-refractory lung inflammation. Ganetespib also suppressed B cell and NK cell accumulation, inflammatory cytokine and chemokine induction and MMP9 levels. These data identify non-myelosuppresssive HSP90 inhibitors as potential therapies for inflammatory diseases refractory to conventional therapy, in particular those of the lung.
PMCID: PMC4304786  PMID: 25615645
11.  Structure-Function Studies of the bHLH Phosphorylation Domain of TWIST1 in Prostate Cancer Cells12 
Neoplasia (New York, N.Y.)  2015;17(1):16-31.
The TWIST1 gene has diverse roles in development and pathologic diseases such as cancer. TWIST1 is a dimeric basic helix-loop-helix (bHLH) transcription factor existing as TWIST1-TWIST1 or TWIST1-E12/47. TWIST1 partner choice and DNA binding can be influenced during development by phosphorylation of Thr125 and Ser127 of the Thr-Gln-Ser (TQS) motif within the bHLH of TWIST1. The significance of these TWIST1 phosphorylation sites for metastasis is unknown. We created stable isogenic prostate cancer cell lines overexpressing TWIST1 wild-type, phospho-mutants, and tethered versions. We assessed these isogenic lines using assays that mimic stages of cancer metastasis. In vitro assays suggested the phospho-mimetic Twist1-DQD mutation could confer cellular properties associated with pro-metastatic behavior. The hypo-phosphorylation mimic Twist1-AQA mutation displayed reduced pro-metastatic activity compared to wild-type TWIST1 in vitro, suggesting that phosphorylation of the TWIST1 TQS motif was necessary for pro-metastatic functions. In vivo analysis demonstrates that the Twist1-AQA mutation exhibits reduced capacity to contribute to metastasis, whereas the expression of the Twist1-DQD mutation exhibits proficient metastatic potential. Tethered TWIST1-E12 heterodimers phenocopied the Twist1-DQD mutation for many in vitro assays, suggesting that TWIST1 phosphorylation may result in heterodimerization in prostate cancer cells. Lastly, the dual phosphatidylinositide 3-kinase (PI3K)-mammalian target of rapamycin (mTOR) inhibitor BEZ235 strongly attenuated TWIST1-induced migration that was dependent on the TQS motif. TWIST1 TQS phosphorylation state determines the intensity of TWIST1-induced pro-metastatic ability in prostate cancer cells, which may be partly explained mechanistically by TWIST1 dimeric partner choice.
PMCID: PMC4309734  PMID: 25622896
EMT, epithelial-mesenchymal transition; bHLH, basic helix-loop-helix; T-T, TWIST1-TWIST1; E12/E47, E2A proteins; T-E, TWIST1-E12; IHC, immunohistochemistry; PI, propidium iodide; PKA, protein kinase A
12.  Effect of a Mobile Phone Intervention on Quitting Smoking in a Young Adult Population of Smokers: Randomized Controlled Trial Study Protocol 
JMIR Research Protocols  2015;4(1):e10.
Tobacco use remains the number one cause of preventable chronic disease and death in developed countries worldwide. In North America, smoking rates are highest among young adults. Despite that the majority of young adult smokers indicate wanting to quit, smoking rates among this age demographic have yet to decline. Helping young adults quit smoking continues to be a public health priority. Digital mobile technology presents a promising medium for reaching this population with smoking cessation interventions, especially because young adults are the heaviest users of this technology.
The primary aim of this trial is to determine the effectiveness of an evidence-informed mobile phone app for smoking cessation, Crush the Crave, on reducing smoking prevalence among young adult smokers.
A parallel randomized controlled trial (RCT) with two arms will be conducted in Canada to evaluate Crush the Crave. In total, 1354 young adult smokers (19 to 29 years old) will be randomized to receive the evidence-informed mobile phone app, Crush the Crave, or an evidence-based self-help guide known as “On the Road to Quitting” (control) for a period of 6 months. The primary outcome measure is a 30-day point prevalence of abstinence at the 6-month follow-up. Secondary outcomes include a 7-day point prevalence of abstinence, number of quit attempts, reduction in consumption of cigarettes, self-efficacy, satisfaction, app utilization metrics, and use of smoking cessation services. A cost-effectiveness analysis is included.
This trial is currently open for recruitment. The anticipated completion date for the study is April 2016.
This randomized controlled trial will provide the evidence to move forward on decision making regarding the inclusion of technology-based mobile phone interventions as part of existing smoking cessation efforts made by health care providers. Evidence from the trial will also inform the development of future apps, provide a deeper understanding of the factors that drive change in smoking behavior using an app, and improve the design of cessation apps. This trial is among the first to assess the effect of a comprehensive and evidence-informed mHealth smoking cessation app on a large sample of young adult smokers. Strengths of the trial include the high-quality research design and in-depth assessment of the implementation of the intervention. If effective, the trial has the potential to demonstrate that including mHealth technology as a population-based intervention strategy can cost-effectively reach a greater proportion of the population and help young adult smokers to quit.
Trial Registration NCT01983150; (Archived by WebCite at
PMCID: PMC4319093  PMID: 25599695
health behavior; smoking cessation; young adult; mobile phone apps; mHealth
13.  Developmental and Post-Injury Cortical Gliogenesis: A Genetic Fate-Mapping Study with Nestin-CreER Mice 
Glia  2009;57(10):1115-1129.
The primary sources of cortical gliogenesis, either during development or after adult brain injury, remain uncertain. We previously generated Nestin-CreER mice to fate-map the progeny of radial glial cells (RG), a source of astrocytes and oligodendrocytes in the nervous system. Here, we show that Nestin-CreER mice label another population of glial progenitors, namely the perinatal subventricular zone (SVZ) glioblasts, if they are crossed with stop-floxed EGFP mice and receive tamoxifen in late embryogenesis (E16-E18). Quantification showed E18 tamoxifen-induction labeled more perinatal SVZ glioblasts than RG and transitional RG combined in the newborn brain (54% vs. 22%). Time-lapse microscopy showed SVZ-glioblasts underwent complex metamorphosis and often-reciprocal transformation into transitional RG. Surprisingly, the E10-dosed RG progenitors produced astrocytes, but no oligodendrocytes, whereas E18-induction fate-mapped both astrocytes and NG2+ oligodendrocyte precursors in the postnatal brain. These results suggest that cortical oligodendrocytes mostly derive from perinatal SVZ glioblast progenitors. Further, by combining genetic fate-mapping and BrdU-labeling, we showed that cortical astrocytes cease proliferation soon after birth (
PMCID: PMC4286201  PMID: 19115384
Subventricular zone (SVZ)-glioblasts; Radial Glia (RG); Gliogenesis; Gliosis; Oligodendrocyte; Astrocyte
Administration and policy in mental health  2014;41(1):10.1007/s10488-013-0501-9.
Quality indicators for programs integrating parent-delivered family support services for children’s mental health have not been systematically developed. Increasing emphasis on accountability under the Affordable Care Act highlights the importance of quality-benchmarking efforts. Using a modified Delphi approach, quality indicators were developed for both program level and family support specialist level practices. These indicators were pilot tested with 21 community-based mental health programs. Psychometric properties of these indicators are reported; variations in program and family support specialist performance suggest the utility of these indicators as tools to guide policies and practices in organizations that integrate parent-delivered family support service components.
PMCID: PMC3858539  PMID: 23709287
Quality Indicators; Delphi Method; Family Support Services; Child Mental Health
Journal of Neurotrauma  2014;31(1):125-134.
Soluble amyloid-beta (Aβ) oligomers are hypothesized to be the pathogenic species in Alzheimer's disease (AD), and increased levels of oligomers in the brain subsequent to traumatic brain injury (TBI) may exacerbate secondary injury pathways and underlie increased risk of developing AD in later life. To determine whether TBI causes Aβ aggregation and oligomerization in the brain, we exposed triple transgenic AD model mice to controlled cortical impact injury and measured levels of soluble, insoluble, and oligomeric Aβ by enzyme-linked immunosorbent assay (ELISA) at 1, 3, and 7 days postinjury. TBI rapidly increased levels of both soluble and insoluble Aβ40 and Aβ42 in the injured cortex at 1 day postinjury. We confirmed previous findings that identified damaged axons as a major site of Aβ accumulation using both immunohistochemistry and biochemistry. We also report that soluble Aβ oligomers were significantly increased in the injured cortex, as demonstrated by both ELISA and Western blot. Interestingly, the mouse brain is able to rapidly clear trauma-induced Aβ, with both soluble and insoluble Aβ species returning to sham levels by 7 days postinjury. In conclusion, we demonstrate that TBI causes acute accumulation and aggregation of Aβ in the brain, including the formation of low- and high-molecular-weight Aβ oligomers. The formation and aggregation of Aβ into toxic species acutely after injury may play a role in secondary injury cascades after trauma and, chronically, may contribute to increased risk of developing AD in later life.
PMCID: PMC3919479  PMID: 24050316
adult brain injury; axonal injury; beta amyloid
Health services research  2014;49(0 2):2173-2187.
This study measures the change in health care use after enrollment into a new public insurance program for low-income childless adults.
Data Sources/Study Setting
The data sources include claims from a large integrated health system in rural Wisconsin and Medicaid enrollment files, January 2007–September 2012.
Study Design
We employ a regression discontinuity design to measure the causal effect of public insurance enrollment on counts of outpatient, emergency department, and inpatient events for two years following enrollment for a sample of previously uninsured low-income adults in rural Wisconsin.
Principal Findings
Public insurance enrollment led to substantial increases in outpatient visits including preventive visits but not mental health visits. Public insurance enrollment also led to increases in inpatient stays, but the study is inconclusive on whether it led to an increase in ED visits.
Public insurance expansions to childless adults have the potential to impact the use of health care. The large increase in Medicaid coverage and reduction in rates of uninsurance anticipated to result from the Affordable Care Act should increase the use of inpatient and outpatient services but will have an uncertain impact on the use of ED among rural populations.
PMCID: PMC4241153  PMID: 25262774
Medicaid; ACA; utilization; health insurance coverage; rural; childless adult
Administration and policy in mental health  2014;41(1):10.1007/s10488-013-0516-2.
PMCID: PMC3880611  PMID: 24005247
Contemporary clinical trials  2013;37(1):58-68.
The prevalence of obesity is high resulting from chronic imbalances between energy intake and expenditure. On the expenditure side, regular exercise is associated with health benefits, including enhanced brain function. The benefits of exercise are not immediate and require persistence to be realized. Brain regions associated with health-related decisions, such as whether or not to exercise or controlling the impulse to engage in immediately rewarding activities (e.g., sedentary behavior), include reward processing and cognitive control regions. A 9 month aerobic exercise study will be conducted in 180 sedentary adults (n = 90 healthy weight [BMI= 18.5 to 26.0 kg/m2]; n = 90 obese [BMI=29.0 to 41.0 kg/m2) to examine the brain processes underlying reward processing and impulse control that may affect adherence in a new exercise regimen. The primary aim is to use functional magnetic resonance imaging (fMRI) to examine reward processing and impulse control among participants that adhere (exercise >80% of sessions) and those that do not adhere to a nine-month exercise intervention with secondary analyses comparing sedentary obese and sedentary healthy weight participants. Our results will provide valuable information characterizing brain activation underlying reward processing and impulse control in sedentary obese and healthy weight individuals. In addition, our results may identify brain activation predictors of adherence and success in the exercise program along with measuring the effects of exercise and improved fitness on brain activation.
PMCID: PMC3946871  PMID: 24291150
Exercise Adherence; Functional Magnetic Resonance Imaging; Obesity
Nature biotechnology  2014;32(7):656-662.
The domestication of citrus, is poorly understood. Cultivated types are selections from, or hybrids of, wild progenitor species, whose identities and contributions remain controversial. By comparative analysis of a collection of citrus genomes, including a high quality haploid reference, we show that cultivated types were derived from two progenitor species. Though cultivated pummelos represent selections from a single progenitor species, C. maxima, cultivated mandarins are introgressions of C. maxima into the ancestral mandarin species, C. reticulata. The most widely cultivated citrus, sweet orange, is the offspring of previously admixed individuals, but sour orange is an F1 hybrid of pure C. maxima and C. reticulata parents, implying that wild mandarins were part of the early breeding germplasm. A wild “mandarin” from China exhibited substantial divergence from C. reticulata, suggesting the possibility of other unrecognized wild citrus species. Understanding citrus phylogeny through genome analysis clarifies taxonomic relationships and enables sequence-directed genetic improvement.
PMCID: PMC4113729  PMID: 24908277
Dimensional approaches are gaining scientific traction. However, their potential for elucidating developmental aspects of psychopathology has not been fully realized. The goal of this paper is to apply a multidimensional, developmental framework to model the normal-abnormal spectrum of preschool disruptive behavior. The Multidimensional Assessment of Preschool Disruptive Behavior (MAP-DB), a novel measure, was used to model dimensional severity across developmental parameters theorized to distinguish the normative misbehavior of early childhood from clinically salient disruptive behavior. The 4 MAP-DB dimensions are: Temper Loss, Noncompliance, Aggression, and Low Concern for Others.
Parents of a diverse sample of 1,488 preschoolers completed the MAP-DB. Multidimensional item response theory (IRT) was employed for dimensional modeling.
The 4-dimension, developmentally informed model demonstrated excellent fit. Its factor loadings did not differ across demographic subgroups. All dimensions provided good coverage of the abnormal end of the severity continuum, but only Temper Loss and Noncompliance provided good coverage of milder, normatively occurring behaviors. The developmental expectability and quality of behaviors distinguished normative from atypical behaviors. The point at which frequency of behaviors was atypical varied based on dimensional location for Temper Loss, Noncompliance, and Aggression.
The MAP-DB provides an innovative method for operationalizing developmentally specified, dimensional phenotypes in early childhood. Establishing the validity of these dimensional phenotypes in relation to clinical outcomes, neurocognitive substrates and etiologic pathways will be a crucial test of their clinical utility.
PMCID: PMC4244819  PMID: 24342388
developmental psychopathology; dimensional; disruptive behavior; externalizing spectrum; preschool
Neuroscience letters  2014;0:259-264.
Prenatal smoking cessation has been described as an empathic action “for the baby,” but this has not been empirically demonstrated. We capitalized on a genetically-characterized extant dataset with outstanding measurement of prenatal smoking patterns and maternal face processing data (as an indicator of empathy) to test this hypothesis, and explore how empathy and smoking patterns may be moderated by a genetic substrate of empathy, the oxytocin receptor gene (OXTR). Participants were 143 Caucasian women from the East Boston Family Study with repeated prospective reports of smoking level, adjusted based on repeated cotinine bioassays. Salivary DNA and face processing (Diagnostic Analysis of Nonverbal Accuracy-2) were assessed 14 years later at an adolescent follow-up of offspring. Two-thirds of participants reported smoking prior to pregnancy recognition. Of these, 21% quit during pregnancy; 56% reduced smoking, and 22% smoked persistently at the same level. A significant interaction between face processing and OXTR variants previously associated with increased sensitivity to social context, rs53576GG and rs2254298A, was found (β = -.181; p = .015); greater ability to identify distress in others was associated with lower levels of smoking during pregnancy for rs53576(GG)/rs2254298(A) individuals (p = .013), but not for other genotypes (p = .892). Testing this “empathy hypothesis of prenatal smoking cessation” in larger studies designed to examine this question can elucidate whether interventions to enhance empathy can improve prenatal smoking cessation rates.
PMCID: PMC4267911  PMID: 25450139
Pregnancy smoking; oxytocin receptor gene; social cognition; nonverbal accuracy; cognitive empathy; differential susceptibility
Blood Transfusion  2015;13(1):32-36.
Leptospirosis is one of the most common bacterial zoonoses worldwide, and clinical manifestations range from asymptomatic infection to acute febrile illness, multi-organ failure and death. Asymptomatic, acute bacteraemia in a blood donor provides a potential for transfusion-transmission, although only a single such case from India has been recorded. Human leptospirosis is uncommon in developed countries; however, the state of Queensland in Australia has one of the highest rates among developed countries, especially after increased rainfall. This study examined the prevalence of antibodies to Leptospira spp. in blood donors residing in higher-risk areas of Australia, to evaluate the appropriateness of current blood safety guidelines.
Materials and methods
Plasma samples collected from blood donors residing in higher-risk areas of Australia during 2009 and 2011 were included in the study. All samples were tested for the presence of antibodies to 22 leptospiral serovars using the microscopic agglutination test.
No sample had antibody titres suggestive of a current or recent infection, however, seven samples (1.44%, 95% CI: 0.38–2.50%) had titres suggestive of a past infection.
This study provides data that may support the appropriateness of current relevant donor selection policies in Australia. Given that the risk profile for leptospirosis is expanding and that the infection is likely to become more prevalent with climate change, this disease may become more of a concern for transfusion safety in the future.
PMCID: PMC4317087  PMID: 24960651
emerging pathogen; climate; rainfall
PLoS ONE  2014;9(12):e115616.
Aging is a natural process involving complex interplay between environment, metabolism, and genes. Sirtuin genes and their downstream targets have been associated with lifespan in numerous organisms from nematodes to humans. Several target proteins of the sirtuin genes are key sensors and/or effectors of oxidative stress pathways including FOXO3, SOD3, and AKT1. To examine the relationship between single nucleotide polymorphisms (SNP) at candidate genes in these pathways and human lifespan, we performed a molecular epidemiologic study of an elderly cohort (≥65 years old.). Using age at death as a continuous outcome variable and assuming a co-dominant genetic model within the framework of multi-variable linear regression analysis, the genotype-specific adjusted mean age at death was estimated for individual SNP genotypes while controlling for age-related risk factors including smoking, body mass index, alcohol consumption and co-morbidity. Significant associations were detected between human lifespan and SNPs in genes SIRT3, SIRT5, SIRT6, FOXO3 and SOD3. Individuals with either the CC or CT genotype at rs107251 within SIRT6 displayed >5-year mean survival advantages compared to the TT genotype (5.5 and 5.9 years, respectively; q-value  = 0.012). Other SNPs revealed genotype-specific mean survival advantages ranging from 0.5 to 1.6 years. Gender also modified the effect of SNPs in SIRT3, SIRT5 and AKT1 on lifespan. Our novel findings highlight the impact of sirtuins and sirtuin-related genotypes on lifespan, the importance of evaluating gender and the advantage of using age as a continuous variable in analyses to report mean age at death.
PMCID: PMC4277407  PMID: 25541994
Journal of neurochemistry  2013;127(1):91-100.
The effects of exercise are not limited to muscle, and its ability to mitigate some chronic diseases is under study. A more complete understanding of how exercise impacts non-muscle tissues might facilitate design of clinical trials and exercise mimetics. Here, we focused on lactate’s ability to mediate changes in liver and brain bioenergetic-associated parameters. In one group of experiments, C57BL/6 mice underwent seven weeks of treadmill exercise sessions at intensities intended to exceed the lactate threshold. Over time, the mice dramatically increased their lactate threshold. To ensure that plasma lactate accumulated during the final week, the mice were run to exhaustion. In the liver, mRNA levels of gluconeogenesis-promoting genes increased. And while PGC-1α expression increased, there was a decrease in PGC-1β expression, and overall gene expression changes favored respiratory chain down-regulation. In the brain, PGC-1α and PGC-1β were unchanged but PRC expression and mtDNA copy number increased. Brain TNFα expression fell, while VEGF-A expression rose. In another group of experiments, exogenously administered lactate was found to reproduce some but not all of these observed liver and brain changes. Our data suggest that lactate, an exercise byproduct, could mediate some of the effects exercise has on the liver and the brain, and that lactate itself can act as a partial exercise mimetic.
PMCID: PMC4276250  PMID: 23927032
exercise; lactate; brain; liver

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