Extremely preterm (EP) survivors have smaller brains, lower IQ, and worse educational achievement than their term-born peers. The contribution of smaller brain size to the IQ and educational disadvantages of EP is unknown. This study aimed (i) to compare brain volumes from multiple brain tissues and structures between EP-born (<28weeks) and term-born (≥37weeks) control adolescents, (ii) to explore the relationships of brain tissue volumes with IQ and basic educational skills and whether this differed by group, and (iii) to explore how much total brain tissue volume explains the underperformance of EP adolescents compared with controls.
Longitudinal cohort study of 148 EP and 132 term controls born in Victoria, Australia in 1991-92. At age 18, magnetic resonance imaging-determined brain volumes of multiple tissues and structures were calculated. IQ and educational skills were measured using the Wechsler Abbreviated Scale of Intelligence (WASI) and the Wide Range Achievement Test(WRAT-4), respectively.
Brain volumes were smaller in EP adolescents compared with controls (mean difference [95% confidence interval] of -5.9% [-8.0, -3.7%] for total brain tissue volume). The largest relative differences were noted in the thalamus and hippocampus. The EP group had lower IQs(-11.9 [-15.4, -8.5]), spelling(-8.0 [-11.5, -4.6]), math computation(-10.3 [-13.7, -6.9]) and word reading(-5.6 [-8.8, -2.4]) scores than controls; all p-values<0.001. Volumes of total brain tissue and other brain tissues and structures correlated positively with IQ and educational skills, a relationship that was similar for both the EP and controls. Total brain tissue volume explained between 20-40% of the IQ and educational outcome differences between EP and controls.
EP adolescents had smaller brain volumes, lower IQs and poorer educational performance than controls. Brain volumes of multiple tissues and structures are related to IQ and educational outcomes. Smaller total brain tissue volume is an important contributor to the cognitive and educational underperformance of adolescents born EP.
Vascular calcification is a hallmark of atherosclerosis, a major cause of morbidity and mortality in the United States. We have previously reported that the osteogenic transcription factor Runx2 is an essential and sufficient regulator of calcification of vascular smooth muscle cells (VSMC) in vitro.
To determine the contribution of osteogenic differentiation of VSMC to the pathogenesis of vascular calcification and the function of VSMC-derived Runx2 in regulating calcification in vivo.
Methods and Results
SMC-specific Runx2 deficient mice, generated by breeding SM22α-Cre mice with the Runx2 exon 8 floxed mice, exhibited normal aortic gross anatomy and expression levels of SMC-specific marker genes. Runx2 deficiency did not affect basal SMC markers, but inhibited oxidative stress-reduced expression of SMC markers. High-fat diet-induced vascular calcification in vivo was markedly inhibited in the Runx2-deficient mice compared with their control littermates. Runx2 deficiency inhibited the expression of receptor activator of nuclear factor κB ligand, which was accompanied by decreased macrophage infiltration and formation of osteoclast-like cells in the calcified lesions. Co-culture of VSMC with bone marrow-derived macrophages demonstrated that the Runx2 deficient VSMC failed to promote differentiation of macrophages into osteoclast-like cells.
These data have determined the importance of osteogenic differentiation of VSMC in the pathogenesis of vascular calcification in mice and defined the functional role of SMC-derived Runx2 in regulating vascular calcification and promoting infiltration of macrophages into the calcified lesion to form osteoclast-like cells. Our studies suggest that the development of vascular calcification is coupled with the formation of osteoclast-like cells, paralleling the bone remodeling process.
vascular smooth muscle cells; osteogenic differentiation; Runx2; vascular calcification; vascular osteoclasts; smooth muscle cells; vascular disease
Persistent postconcussive symptoms (PCSs) is the persistence of somatic, cognitive, physical, psychological and/or behavioural changes lasting more than 1 month following concussion. Persistent concussion impacts the quality of life through impaired cognition, memory and attention affecting school performance, mood and social engagement. No large epidemiological studies have determined the true prevalence of persistent concussion symptoms. Validated, easy-to-use prognosticators do not exist for clinicians to identify children at highest risk. The goal of Predicting and Preventing Postconcussive Problems in Pediatrics study is to derive a clinical prediction rule for the development of persistent postconcussion symptoms in children and adolescents presenting to emergency department following acute head injury.
Methods and analysis
This study is a prospective, multicentre cohort study across nine academic Canadian paediatric emergency departments. We will recruit the largest prospective epidemiological cohort of children with concussion. Eligible children will be followed using Post-Concussion Symptom Inventory, a validated tool in children as young as 5 years. Patients will follow-up at 1, 2, 4, 8 and 12 weeks postinjury. The main outcome will be the presence/absence of PCSs defined as three or more persistent concussion symptoms 1 month following the injury. 1792 patients provide adequate power to derive a clinical decision rule using multivariate analyses to find predictor variables sensitive for detecting cases of persistent postconcussion symptoms.
Ethics and dissemination
Results of this large prospective study will enable clinicians to identify children at highest risk, optimise treatment and provide families with realistic and appropriate anticipatory guidance. Ethics has been obtained through the Children's Hospital of Eastern Ontario Research Ethics Board. Results will be disseminated at international conferences and in four manuscripts to peer-reviewed journals.
This study is registered at Clinicaltrials.gov through the US National Institute of Health/National Library of Medicine (NCT01873287; http://clinicaltrials.gov/ct2/show/NCT01873287).
Accident & Emergency Medicine; Epidemiology; Sports Medicine; Paediatrics
Drug concentrations associated with protection from HIV-1 acquisition have not been determined. This study evaluated drug concentrations among men who have sex with men in a substudy of the iPrEx trial,(1) a randomized placebo controlled trial of daily oral emtricitabine/tenofovir disoproxil fumarate pre-exposure prophylaxis (PrEP). Any detectable drug in blood plasma and viably cryopreserved peripheral blood mononuclear cells (vPBMCs) was less frequent in HIV-infected cases at the visit when HIV was first discovered compared with controls at the matched time point of the study (8% vs 44%, P<0.001) and in the 90 days prior to that visit (11% vs 51%, P<0.001). An intracellular tenofovir-diphosphate (TFV-DP) concentration of 16 fmol per million vPBMCs was associated with a 90% reduction in HIV acquisition relative to the placebo arm. Directly observed dosing in a separate study, STRAND, yielded TFV-DP concentrations that, when analyzed with this iPrEx model, corresponded with HIV-1 risk reduction of 76% for 2 doses per week, 96% for 4 doses per week, 99% for 7 doses per week. Prophylactic benefits were observed over a range of doses and drug concentrations, suggesting ways to optimize PrEP regimens for this population.
Remediation of hydrocarbon contaminated soils can be performed both in situ and ex situ using chemical oxidants such as sodium persulfate. Standard methods for quantifying persulfate require either centrifugation or prolonged settling times. An optimized soil extraction procedure was developed for persulfate involving simple water extraction using a modified disposable syringe. This allows considerable saving of time and removes the need for centrifugation. The extraction time was reduced to only 5 min compared to 15 min for the standard approach. A comparison of the two approaches demonstrated that each provides comparable results. Comparisons were made using high (93 g kg−1 soil) and low (9.3 g kg−1 soil) additions of sodium persulfate to a petroleum hydrocarbon-contaminated soil, as well as sand spiked with diesel. Recoveries of 95±1% and 96±10% were observed with the higher application rate in the contaminated soil and spiked sand, respectively. Corresponding recoveries of 86±5% and 117±19% were measured for the lower application rate. Results were obtained in only 25 min and the method is well suited to batch analyses. In addition, it is suitable for application in a small field laboratory or even a mobile, vehicle-based system, as it requires minimal equipment and reagents.
Feedback to clinical learners about their performance is crucial to their development into competent clinicians. Most feedback is provided by clinicians who have little or no formal training for this aspect of their teaching role.
Feedback is most effective if provided by clinical mentors based on observations of behavior, with emphasis on correctable deficiencies. The difference between feedback, which is formative, and evaluation, which is summative, needs to be understood by both the giver and receiver. The ability to self-assess is an important related concept, with studies showing that self-assessment skills are lowest in individuals found to be the least competent in external assessments and in individuals with a high level of confidence.
Feedback is an important component in learners' development, and clinical faculty should be educated about the importance of providing feedback, and the means to do so effectively must be provided to them. Despite several decades of accumulated knowledge in this area, the evidence from learners is that we continue to starve them of this critical nutrient for their growth.
Ewing sarcoma occurs in children, adolescents and young adults. High STAT3 levels have been reported in approximately 50% of patients with Ewing sarcoma, and may be important in tumorigenesis. Protein tyrosine phosphatase delta (PTPRD) is a tumor suppressor that inhibits STAT3 activation. To date, while somatic mutations in PTPRD have been reported in diverse tumors, germline mutations of PTPRD have not been investigated in Ewing sarcoma or other cancers. We identified a novel germline mutation in the PTPRD gene in three of eight patients (37.5%) with metastatic Ewing sarcoma. Although the functional impact in two of the patients is unclear, in one of them the aberration was annotated as a W775stop germline mutation, and would be expected to lead to gene truncation and, hence, loss of the STAT3 dephosphorylation function of PTPRD. Since STAT3 is phosphorylated after being recruited to the insulin growth factor receptor (IGF-1R), suppression of IGF-1R could attenuate the enhanced STAT3 activation expected in the presence of PTPRD mutations. Of interest, two of three patients with germline PTPRD mutations achieved durable complete responses following treatment with IGF-1R monoclonal antibody-based therapies. Our pilot data suggest that PTPRD germline mutations may play a role in the development of Ewing sarcoma, a disease of young people, and their presence may have implications for therapy.
Ewing sarcoma; PTPRD; mutation; germline
Boceprevir and telaprevir, when added to pegylated interferon and ribavirin for the treatment of chronic hepatitis C virus infection, increase the rates of sustained virologic response in treatment naïve persons to approximately 70%. While these agents represent an important advance in the treatment of chronic hepatitis C virus, they present new treatment challenges to the Hepatology community. Boceprevir and telaprevir are both substrates and inhibitors of the hepatic enzyme cytochrome P450 3A and the drug transporter, P-glycoprotein, which predisposes these agents to many drug interactions. Identification and appropriate management of potential drug interactions with telaprevir and boceprevir is critical for optimizing therapeutic outcomes during hepatitis C treatment. This review highlights the pharmacologic characteristics and drug interaction potential of boceprevir and telaprevir and provides guidance on the management of drug interactions with these agents.
boceprevir; telaprevir; pharmacology; pharmacokinetics; drug interactions
The aim of this study was to relate altered corpus callosum (CC) integrity in 106 very preterm (VPT) infants (<30 weeks’ gestational age or <1250 g birth weight) at term equivalent to perinatal predictors and neurodevelopmental outcomes at two years. T1 and diffusion magnetic resonance images were obtained. The CC was traced, and divided into six sub-regions for cross-sectional area and shape analyses. Fractional anisotropy, mean, axial and radial diffusivity was sampled within the CC, and probabilistic tractography performed. Perinatal predictors were explored. The Bayley Scales of Infant Development (BSID-II) was administered at two years. Intraventricular hemorrhage was associated with a smaller genu and altered diffusion values within the anterior and posterior CC of VPT infants. White matter injury was associated with widespread alterations to callosal diffusion values, especially posteriorly, and radial diffusivity was particularly elevated, indicating altered myelination. Reduced CC tract volume related to lower gestational age, particularly posteriorly. Reduced posterior callosal skew was associated with postnatal corticosteroid exposure. This more circular CC was associated with delayed cognitive development. Higher diffusivity, particularly in splenium tracts, was associated with impaired motor development. This study elucidates perinatal predictors and adverse neurodevelopmental outcomes associated with altered callosal integrity in VPT infants.
Brain; Prematurity; Neonate; Magnetic resonance imaging; Diffusion tensor imaging; Tractography
Preterm children are at risk for social-emotional difficulties, including autism and attention deficit hyperactivity disorder. We assessed the relationship of regional brain development in preterm children, evaluated via MRI at term-equivalent postmenstrual age (TEA), to later social-emotional difficulties.
MR images obtained at TEA from 184 very preterm infants (gestation <30 weeks or birthweight <1250 g) were analyzed for white matter abnormalities, hippocampal volume, and brain metrics. 111 infants underwent diffusion tensor imaging, which provided values for fractional anisotropy (FA) and apparent diffusion coefficient (ADC). Social-emotional development was assessed with the Infant Toddler Social and Emotional Assessment (ITSEA) at age 2 and the Strengths and Difficulties Questionnaire (SDQ) at age 5.
Higher ADC in the right orbitofrontal cortex was associated with social-emotional problems at age 5 (peer problems, p<0.01). In females, smaller hippocampal volume was associated with increased hyperactivity (p<0.01), peer problems (p<0.05) and SDQ total score (p<0.01). In males, a smaller frontal region was associated with poorer prosocial (p<0.05) scores. Many of the hippocampal findings remained significant after adjusting for birthweight z score, intelligence, social risk, immaturity at birth, and parental mental health. These associations were present in children who had social-emotional problems in similar domains at age 2 and those who did not.
Early alterations in regional cerebral development in very preterm infants relate to specific deficits in social-emotional performance by school-age. These results vary by gender. Our results provide further evidence for a neuroanatomical basis for behavioral challenges found in very preterm children.
Preterm infant; Neurodevelopment; social-emotional development; orbitofrontal cortex; Hippocampus
The European level of alcohol consumption, and the subsequent burden of disease, is high compared to the rest of the world. While screening and brief interventions in primary healthcare are cost-effective, in most countries they have hardly been implemented in routine primary healthcare. In this study, we aim to examine the effectiveness and efficiency of three implementation interventions that have been chosen to address key barriers for improvement: training and support to address lack of knowledge and motivation in healthcare providers; financial reimbursement to compensate the time investment; and internet-based counselling to reduce workload for primary care providers.
In a cluster randomized factorial trial, data from Catalan, English, Netherlands, Polish, and Swedish primary healthcare units will be collected on screening and brief advice rates for hazardous and harmful alcohol consumption. The three implementation strategies will be provided separately and in combination in a total of seven intervention groups and compared with a treatment as usual control group. Screening and brief intervention activities will be measured at baseline, during 12 weeks and after six months. Process measures include health professionals’ role security and therapeutic commitment of the participating providers (SAAPPQ questionnaire). A total of 120 primary healthcare units will be included, equally distributed over the five countries. Both intention to treat and per protocol analyses are planned to determine intervention effectiveness, using random coefficient regression modelling.
Effective interventions to implement screening and brief interventions for hazardous alcohol use are urgently required. This international multi-centre trial will provide evidence to guide decision makers.
ClinicalTrials.gov. Trial identifier: NCT01501552
Alcohol; Screening; Brief interventions; Primary healthcare; Training and support; Financial reimbursement; Internet; Implementation
A sensitive LC/MS/MS assay for determining zidovudine (ZDV) and lamivudine (3TC) in human plasma was validated to support antiretroviral pharmacology research programs. After addition of stable labeled isotopic zidovudine (ZDV-IS) and lamivudine (3TC-IS) as internal standard, a solid phase extraction was performed with an Oasis HLB 1cc cartridge, with recoveries of 92.3% for ZDV and 93.9% for 3TC. A Phenomonex Synergi Hydro-RP (2.0 × 150 mm) reversed phase analytical column was utilized for chromatographic separation. Mobile phase consisted of an aqueous solution of 15% acetonitrile and 0.1% acetic acid. Detection was accomplished by ESI/MS/MS in the positive ion mode, monitoring 268/127 and 271/130, and 230/112 and 233/115 transitions, for ZDV and ZDV-IS and 3TC and 3TC-IS, respectively. The method was linear from 1 to 3000 ng/mL with a minimum quantifiable limit of 1 ng/mL when 100 μL of plasma were analyzed. Validations results demonstrated high accuracy (≤ 8.3% deviation) and high precision (≤ 10% CV) for the quality control samples. The method was also shown to be specific and reproducible. The value of the high sensitivity was demonstrated by quantitation of approximately 100 existing samples that had ZDV below the limit of quantitation using a previously validated, less sensitive HPLC-UV method utilized in the laboratory.
lamivudine; zidovudine; human plasma; LC/MS/MS
The cellular pharmacology of zidovudine (ZDV) and lamivudine (3TC) in vivo is not completely understood. This prospective longitudinal study investigated the relationship between HIV-1 serostatus, sex, race, and time on therapy with intracellular and plasma ZDV and 3TC concentrations. Of 20 HIV-seronegative and 23 HIV-seropositive volunteers enrolled, 16 (8 women) and 21 (5 women) completed all 12 study days, respectively. Volunteers began ZDV-3TC therapy (plus a third active drug in HIV-seropositive volunteers), and steady-state concentrations (Css) were determined after days 1, 3, 7, and 12. A repeated-measures mixed model was utilized. HIV-seronegative status was associated with 22% (95% confidence interval [CI], 0%, 50%) and 37% (15%, 67%) higher Css estimates compared to those of HIV-seropositive individuals for intracellular ZDV-TP and 3TC-TP levels, respectively. African-Americans had 36% (8%, 72%) higher ZDV-TP estimates than non-African-Americans. Sex was not associated with ZDV-TP or 3TC-TP (P > 0.19). Women had 36% (4%, 78%) higher plasma ZDV, but the effect was lessened when normalized by lean body weight (5% [−19%, 38%]; P = 0.68). Plasma 3TC was 19% (0%, 41%) higher in HIV-seropositive volunteers and 22% (0%, 48%) higher in African American volunteers, but these effects were not significant when corrected for creatinine clearance (7% [−9%, 20%] and −5% [−26%, 12%] for HIV serostatus and race, respectively; P > 0.35). These results suggest that HIV-seropositive status decreases and African American race elevates the cellular triphosphates of ZDV and 3TC. This information extends knowledge of ZDV and 3TC cellular pharmacology in vivo and provides new leads for future cellular pharmacology studies aimed at optimizing HIV prevention/treatment with these agents.
The main impairment to tissue maintenance during aging is the reduced capacity for stem cell self-renewal over time due to senescence, the irreversible block in proliferation. We have previously described that the basic helix-loop-helix (bHLH) transcription factor Twist-1 can greatly enhance the life span of bone marrow-derived mesenchymal stem/stromal cells (MSCs). In the present study, we show that Twist-1 potently suppresses senescence and the Ink4A/Arf locus with a dramatic decrease in the expression of p16 and to some extent a decrease in p14. Furthermore, the polycomb group protein and histone methyltransferase Ezh2, which suppresses the Ink4A/Arf locus, was found to be induced by Twist-1, resulting in an increase in H3K27me3 along the Ink4A/Arf locus, repressing transcription of both p16/p14 and senescence of human MSCs. Furthermore, Twist-1 inhibits the expression of the bHLH transcription factor E47, which is normally expressed in senescent MSCs and induces transcription of the p16 promoter. Reduced Twist-1 wild-type expression and function in bone cells derived from Saethre-Chotzen patients also revealed an increase in senescence. These studies for the first time link Twist-1 to histone methylation of the Ink4A/Arf locus by controlling the expression of histone methyltransferases as well as the expression of other bHLH factors.
Multiple sclerosis (MS) is a chronic progressive neurological disease and the majority of patients will experience some degree of impaired mobility. We evaluated the prevalence, severity and burden of walking and mobility problems (WMPs) in 5 European countries.
This was a cross-sectional, patient record-based study involving 340 neurologists who completed detailed patient record forms (PRF) for patients (>18 years) attending their clinic with MS. Patients were also invited to complete a questionnaire (PSC). Information collected included demographics, disease characteristics, work productivity, quality of life (QoL; EuroQol-5D and Hamburg Quality of Life Questionnaire Multiple Sclerosis [HAQUAMS]) and mobility (subjective patient-reported and objectively measured using the timed 25 foot walk test [T25FW]). Relationships between WMPs and disease and other characteristics were examined using Chi square tests. Analysis of variance was used to examine relationships between mobility measures and work productivity.
Records were available for 3572 patients of whom 2171 also completed a PSC. WMPs were regarded as the most bothersome symptom by almost half of patients who responded (43%; 291/683). There was a clear, independent and strong directional relationship between severity of WMPs (subjective and objective) and healthcare resource utilisation. Patients with longer T25FW times (indicating greater walking impairment) were significantly more likely to require additional caregiver support (p < 0.0001), visit a variety of healthcare professionals including their primary care physicians (p = 0.0044) and require more long-term non-disease modifying drugs (p = 0.0001). A similar pattern was observed when subjective reporting of the severity of WMPs was considered. Work productivity was also markedly impacted by the presence of WMPs with fewer patients working full time and a reduction in weekly working hours as T25FW times and the subjective severity of WMPs increased.
In Europe, WMPs in MS represent a considerable personal and social burden both financially and in terms of quality of life. Interventions to improve mobility could have significant benefits for patients and society as a whole.
Multiple sclerosis; Walking; Mobility; Impairment; Burden; Work productivity; Quality of life; Independence
An ultra-sensitive liquid chromatography tandem mass spectrometry (LC-MS/MS) assay was developed and validated to facilitate the assessment of clinical pharmacokinetics of nucleotide analogs from lysed intracellular matrix. The method utilized a strong anion exchange isolation of mono-(MP), di-(DP), and tri-phosphates (TP) from intracellular matrix. Each fraction was then dephosphorylated to the parent moiety yielding a molar equivalent to the original nucleotide analog intracellular concentration. The analytical portion of the methodology was optimized in specific nucleoside analog centric modes (i.e. tenofovir (TFV) centric, zidovudine (ZDV) centric), which included desalting/concentration by solid phase extraction and detection by LC-MS/MS. Nucleoside analog MP-, DP-, and TP- determined on the TFV centric mode of analysis include TFV, lamivudine (3TC), and emtricitibine (FTC). The quantifiable linear range for TFV was 2.50 to 2000 fmol/sample, and that for 3TC/FTC was 0.10 to 200 pmol/sample. Nucleoside analog MP-, DP-, and TP- determined on the ZDV centric mode of analysis included 3TC and ZDV. The quantifiable linear range for 3TC was 0.10 to 100 pmol/sample, and 5.00 to 2000 fmol/sample for ZDV. Stable labeled isotopic internal standards facilitated accuracy and precision in alternative cell matrices, which supported the intended use of the method for MP, DP, and TP determinations in various cell types. The method was successfully applied to clinical research samples generating novel intracellular information for TFV, FTC, ZDV, and 3TC nucleotides. This document outlines method development, validation, and application to clinical research.
Clinical Pharmacology; Analytical Methods; Nucleoside Analogs; Intracellular Pharmacology; LC-MS/MS
Achieving efficient introduction of plasmid DNA into primary cultures of mammalian cells is a common problem in biomedical research. Human primary cranial suture cells are derived from the connective mesenchymal tissue between the bone forming regions at the edges of the calvarial plates of the skull. Typically they are referred to as suture mesenchymal cells and are a heterogeneous population responsible for driving the rapid skull growth that occurs in utero and postnatally. To better understand the molecular mechanisms involved in skull growth, and in abnormal growth conditions, such as craniosynostosis, caused by premature bony fusion, it is essential to be able to easily introduce genes into primary bone forming cells to study their function.
A comparison of several lipid-based techniques with two electroporation-based techniques demonstrated that the electroporation method known as nucleofection produced the best transfection efficiency. The parameters of nucleofection, including cell number, amount of DNA and nucleofection program, were optimized for transfection efficiency and cell survival. Two different genes and two promoter reporter vectors were used to validate the nucleofection method and the responses of human primary suture mesenchymal cells by fluorescence microscopy, RT-PCR and the dual luciferase assay. Quantification of bone morphogenetic protein (BMP) signalling using luciferase reporters demonstrated robust responses of the cells to both osteogenic BMP2 and to the anti-osteogenic BMP3.
A nucleofection protocol has been developed that provides a simple and efficient, non-viral alternative method for in vitro studies of gene and protein function in human skull growth. Human primary suture mesenchymal cells exhibit robust responses to BMP2 and BMP3, and thus nucleofection can be a valuable method for studying the potential competing action of these two bone growth factors in a model system of cranial bone growth.
Transfection; Nucleofection; Skull; Bone; Primary cell culture; Mesenchymal; BMP2; luciferase
Urinary tract infections (UTIs) are among the most common bacterial infections and are responsible for significant morbidity and health care costs worldwide. The main bacterial cause of uncomplicated UTI is Escherichia coli, which possesses numerous virulence factors (VFs). Many studies of the pathogenesis of E. coli UTI have centered on VF genes. Hence, the development of better molecular assays to study VF genes would facilitate these studies. We developed a highly sensitive and specific multiplex PCR-based reverse line blot (mPCR/RLB) assay to simultaneously detect 22 VF genes of uropathogenic E. coli and then used it to characterize 180 isolates from nonpregnant women of child-bearing age with cystitis and 153 fecal isolates from similar-age healthy women, in regional New South Wales, Australia. The assay accurately identified all VF genes (of the 22 under study) known to be present in 30 previously characterized control strains. The detection limits were 28 ng of DNA from E. coli isolates and 50 CFU/ml in mock-infected urine specimens containing known concentrations of E. coli. Cystitis isolates (compared to the fecal isolates) showed a significantly higher prevalence of 18 individual VF genes and contained significantly more VF genes per isolate (median number, 18.5 versus 6.5 [P = 0.001]). Discordance between paired probes for a given VF gene occurred in several clinical test isolates but no reference strains and among the test isolates was associated with fecal source (10% of VF genes versus 2% for cystitis isolates [P < 0.001]). This novel mPCR/RLB method is a potentially powerful tool for investigating the prevalence and distribution of VFs in E. coli.
Internet interventions have the potential to address many of the health problems that produce the greatest global burden of disease. We present a study illustrating this potential. The Spanish/English San Francisco Stop Smoking Internet site, which yielded quit rates of 20% or more at 12 months in published randomized controlled trials (RCTs), was modified to make it accessible to Spanish- and English-speaking smokers 18 years of age or older anywhere in the world.
To illustrate that Internet interventions designed to conduct RCTs can be adapted to serve as universal health care resources. We also examine quit rates obtained in the current participant preference study (in which users could choose from all elements tested in previous RCTs) to determine whether they differ from the quit rates found in the RCTs.
We modified the San Francisco Stop Smoking Internet site so that, instead of being randomly assigned to a specific intervention, participants could personalize the site by choosing among nine site elements (eg, stop smoking guide, reminder emails, journal, mood management intervention, or virtual group). Participants completed a baseline assessment, and reported smoking and mood data at 1-, 3-, 6-, and 12-month follow-ups. We assessed the modified website’s reach and outcomes (quit rates), and compared the quit rates of the current participant preference study with those of the previous RCTs.
In the first year of recruitment, 94,158 individuals from 152 countries and territories visited the site; 13,488 participants left some data; 9173 signed consent; 7763 completed the baseline survey; and 1955, 1362, 1106, and 1096 left 1-, 3-, 6-, and 12-month data, respectively. Observed quit rates were 38.1% (n = 668), 44.9% (n = 546), 43.6% (n = 431), and 45.4% (n = 449), respectively. The current participant preference study yielded higher observed quit rates (odds ratio 1.30) than the previous RCT when controlling for individuals’ demographic and smoking characteristics.
After strict RCTs are completed, Internet intervention sites can be made into worldwide health intervention resources without reducing their effectiveness.
Clinicaltrials.gov NCT00721786; http://clinicaltrials.gov/ct2/show/NCT00721786 (Archived by WebCite at http://www.webcitation.org/66npiZF4y)
Internet intervention; smoking cessation; international resources; Spanish; English; outcome study
Clinical and experimental studies demonstrate the important roles of vascular smooth muscle cells (VSMC) in the pathogenesis of atherosclerosis. We have previously determined that osteogenic transcription factor, Runx2, is essential for VSMC calcification. The present studies characterized Runx2-regulated signals and their potential roles in vascular calcification.
Methods and Results
In vivo studies with atherogenic ApoE−/− mice demonstrated that increased oxidative stress was associated with upregualtion of Runx2 and receptor activator of nuclear factor κB ligand (RANKL), which colocalized in the calcified atherosclerotic lesions and were juxtaposed to infiltrated macrophages and osteoclast-like cells that are positively stained for an osteoclast marker, tartrate-resistant acid phosphatase (TRAP). Mechanistic studies using RNA interfering, a luciferase reporter system, chromatin immunoprecipitation and electrophoretic mobility shift assays identified that Runx2 regulated the expression of RANKL via a direct binding to the 5'-flanking region of the RANKL. Functional characterization revealed that RANKL did not induce VSMC calcification, nor RANKL was required for oxidative stress-induced VSMC calcification. Using a co-culture system, we demonstrated VSMC-expressed RANKL induced migration as well as differentiation of bone marrow-derived macrophages into multinucleated, TRAP-positive osteoclast-like cells. These effects were inhibited by the RANKL antagonist, osteoprotegerin, and with VSMC deficient in Runx2 or RANKL.
We demonstrate that Runx2 directly binds to the promoter and controls the expression of RANKL, which mediates the crosstalk between calcifying VSMC and migration and differentiation of macrophages into osteoclast-like cells in the atherosclerotic lesions. Our studies provide novel mechanistic insights into the regulation and function of VSMC-derived RANKL in the pathogenesis of atherosclerosis and vascular calcification.
RANKL; Runx2; calcification; osteoclastogenesis; migration
RT-qPCR is a common tool for quantification of gene expression, but its accuracy is dependent on the choice and stability (steady state expression levels) of the reference gene/s used for normalization. To date, in the bone field, there have been few studies to determine the most stable reference genes and, usually, RT-qPCR data is normalised to non-validated reference genes, most commonly GAPDH, ACTB and 18 S rRNA. Here we draw attention to the potential deleterious impact of using classical reference genes to normalise expression data for bone studies without prior validation of their stability.
Using the geNorm and Normfinder programs, panels of mouse and human genes were assessed for their stability under three different experimental conditions: 1) disease progression of Crouzon syndrome (craniosynostosis) in a mouse model, 2) proliferative culture of cranial suture cells isolated from craniosynostosis patients and 3) osteogenesis of a mouse bone marrow stromal cell line. We demonstrate that classical reference genes are not always the most ‘stable’ genes and that gene ‘stability’ is highly dependent on experimental conditions. Selected stable genes, individually or in combination, were then used to normalise osteocalcin and alkaline phosphatase gene expression data during cranial suture fusion in the craniosynostosis mouse model and strategies compared. Strikingly, the expression trends of alkaline phosphatase and osteocalcin varied significantly when normalised to the least stable, the most stable or the three most stable genes.
To minimise errors in evaluating gene expression levels, analysis of a reference panel and subsequent normalization to several stable genes is strongly recommended over normalization to a single gene. In particular, we conclude that use of single, non-validated “housekeeping” genes such as GAPDH, ACTB and 18 S rRNA, currently a widespread practice by researchers in the bone field, is likely to produce data of questionable reliability when changes are 2 fold or less, and such data should be interpreted with due caution.
Osteocalcin; Alkaline phosphatase; 18 S RNA; Gapdh; β-actin; geNorm; Normfinder; Craniosynostosis; Bone; Mineralization