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
The effect of repeated exposure to sensory stimuli, with or without reward is well known to induce stimulus-specific modifications of behaviour, described as different forms of learning. In recent studies we showed that a brief single pre-exposure to the female-produced sex pheromone or even a predator sound can increase the behavioural and central nervous responses to this pheromone in males of the noctuid moth Spodoptera littoralis. To investigate if this increase in sensitivity might be restricted to the pheromone system or is a form of general sensitization, we studied here if a brief pre-exposure to stimuli of different modalities can reciprocally change behavioural and physiological responses to olfactory and gustatory stimuli. Olfactory and gustatory pre-exposure and subsequent behavioural tests were carried out to reveal possible intra- and cross-modal effects. Attraction to pheromone, monitored with a locomotion compensator, increased after exposure to olfactory and gustatory stimuli. Behavioural responses to sucrose, investigated using the proboscis extension reflex, increased equally after pre-exposure to olfactory and gustatory cues. Pheromone-specific neurons in the brain and antennal gustatory neurons did, however, not change their sensitivity after sucrose exposure. The observed intra- and reciprocal cross-modal effects of pre-exposure may represent a new form of stimulus-nonspecific general sensitization originating from modifications at higher sensory processing levels.
The corpus callosum is the largest white matter tract, important for interhemispheric communication. The aim of this study was to investigate and compare corpus callosum size, shape and diffusion characteristics in 106 very preterm infants and 22 full-term infants. Structural and diffusion magnetic resonance images were obtained at term equivalent. The corpus callosum was segmented, cross-sectional areas were calculated, and shape was analyzed. Fractional anisotropy, mean, axial and radial diffusivity measures were obtained from within the corpus callosum, with additional probabilistic tractography analysis. Very preterm infants had significantly reduced callosal cross sectional area compared with term infants (p=0.004), particularly for the mid-body and posterior sub-regions. Very preterm callosi were more circular (p=0.01). Fractional anisotropy was lower (p=0.007) and mean (p=0.006) and radial (p=0.001) diffusivity values were higher in very preterm infants’ callosi, particularly at the anterior and posterior ends. The volume of tracts originating from the corpus callosum was reduced in very preterm infants (p=0.001), particularly for anterior mid-body (p=0.01) and isthmus tracts (p=0.04). This study characterizes callosal size, shape and diffusion in typically developing infants at term equivalent age, and reports macro- and micro-structural abnormalities as a result of prematurity.
Brain; Corpus callosum; Prematurity; Neonate; Infant; Magnetic resonance imaging; Diffusion tensor imaging
The use of antiretroviral medications in HIV-negative individuals as pre-exposure prophylaxis (PrEP) is a promising approach to prevent HIV infection. Tenofovir disoproxil fumarate (TDF) and emtricitabine exhibit desirable properties for PrEP including: favourable pharmacokinetics that support infrequent dosing; few major drug-drug or drug-food interactions; an excellent clinical safety record; and pre-clinical evidence for efficacy. Several large, randomized, controlled clinical trials are evaluating the safety and efficacy of TDF and emtricitabine for this new indication. A thorough understanding of variability in drug response will help determine future investigations in the field and/or implementation into clinical care. Because tenofovir and emtricitabine are nucleos(t)ide analogues, the HIV prevention and toxicity effects depend on the triphosphate analogue formed intracellularly. This review identifies important cellular pharmacology considerations for tenofovir and emtricitabine, which include drug penetration into relevant tissues and cell types, race/ethnicity/pharmacogenetics, gender, cellular activation state and appropriate episodic or alternative dosing strategies based on pharmacokinetic principles. The current state of knowledge in these areas is summarized and the future utility of intracellular pharmacokinetics/pharmacodynamics for the PrEP field is discussed.
clinical pharmacology; intracellular pharmacology; pharmacokinetics; pharmacodynamics; pharmacogenomics; nucleoside analogue pharmacology
Sulfur-containing aroma compounds are key contributors to the flavor of a diverse range of foods and beverages. The tropical fruit characters of Vitis vinifera L. cv. Sauvignon blanc wines are attributed to the presence of the aromatic thiols 3-mercaptohexan-1-ol (3MH), 3-mercaptohexan-1-ol-acetate, and 4-mercapto-4-methylpentan-2-one (4MMP). These volatile thiols are found in small amounts in grape juice and are formed from nonvolatile cysteinylated precursors during fermentation. In this study, we overexpressed a Saccharomyces cerevisiae gene, STR3, which led to an increase in 3MH release during fermentation of a V. vinifera L. cv. Sauvignon blanc juice. Characterization of the enzymatic properties of Str3p confirmed it to be a pyridoxal-5′-phosphate-dependent cystathionine β-lyase, and we demonstrated that this enzyme was able to cleave the cysteinylated precursors of 3MH and 4MMP to release the free thiols. These data provide direct evidence for a yeast enzyme able to release aromatic thiols in vitro that can be applied in the development of self-cloned yeast to enhance wine flavor.
Organisms are attacked by different natural enemies present in their habitat. While enemies such as parasitoids and predators will kill their hosts/preys when they successfully attack them, enemies such as micropredators will not entirely consume their prey. However, they can still have important consequences on the performance and ecology of the prey, such as reduced growth, increased emigration, disease transmission.
In this paper, we investigated the impact of a terrestrial micropredator, the yellow fever mosquito Aedes aegypti, on its unusual invertebrate host, the Egyptian cotton leaf worm, Spodoptera littoralis. Larvae developing in presence of mosquitoes showed a slower development and reached a smaller pupal weight when compared to a control without mosquitoes, apparently because of a reduced feeding time for larvae. In addition, larvae tended to leave the plant in presence of mosquitoes.
These results suggest that mosquitoes act as micropredators and affects lepidopteran larvae behaviour and development. Ecological impacts such as higher risks of food depletion and longer exposure to natural enemies are likely to be costly consequences. The importance of this phenomenon in nature – the possible function as last resort when vertebrates are unavailable – and the evolutionary aspects are discussed.
The premature fusion of the paired frontal bones results in metopic craniosynostosis (MC) and gives rise to the clinical phenotype of trigonocephaly. Deletions of chromosome 9p22.3 are well described as a cause of MC with variably penetrant midface hypoplasia. In order to identify the gene responsible for the trigonocephaly component of the 9p22.3 syndrome, a cohort of 109 patients were assessed by high-resolution arrays and MLPA for copy number variations (CNVs) involving 9p22. Five CNVs involving FREM1, all of which were de novo variants, were identified by array-based analyses. The remaining 104 patients with MC were then subjected to targeted FREM1 gene re-sequencing, which identified 3 further mutant alleles, one of which was de novo. Consistent with a pathogenic role, mouse Frem1 mRNA and protein expression was demonstrated in the metopic suture as well as in the pericranium and dura mater. Micro-computed tomography based analyses of the mouse posterior frontal (PF) suture, the human metopic suture equivalent, revealed advanced fusion in all mice homozygous for either of two different Frem1 mutant alleles, while heterozygotes exhibited variably penetrant PF suture anomalies. Gene dosage-related penetrance of midfacial hypoplasia was also evident in the Frem1 mutants. These data suggest that CNVs and mutations involving FREM1 can be identified in a significant percentage of people with MC with or without midface hypoplasia. Furthermore, we present Frem1 mutant mice as the first bona fide mouse model of human metopic craniosynostosis and a new model for midfacial hypoplasia.
Although twin and family studies have shown that genes play a critical role in the timing of fusion of skull bones, the identification of specific genes that may be involved has remained somewhat elusive except in the case of the dominantly inherited craniosynostosis syndromes. Metopic craniosynostosis (MC), the early fusion of the forehead (frontal) bones, accounts for 5%–15% of all craniosynostosis cases. This premature fusion of the frontal bones results in a characteristically altered skull shape, termed trigonocephaly, that usually requires surgical correction. Remarkably, the cause of the majority of cases of MC remains unknown (idiopathic). Here, we report genetic variants involving chromosome 9 which involve and interrupt the structure of the FREM1 gene in a large cohort of patients presenting with unisutural metopic craniosynostosis. Micro-computed tomographic (microCT) imaging and quantitative analysis of skull shape reveal both premature fusion of the PF suture (metopic equivalent) and also changes in frontal bone shape supportive of a role for Frem1 in regulation of the metopic suture. Taken together with Frem1 gene and protein expression findings, these data indicate that mutations in FREM1 can give rise to metopic craniosynostosis.
Osteosarcoma is the most common skeletal malignancy in the dog and in young humans. Although chemotherapy improves survival time, death continues to be attributed to metastases. Aerosol delivery can provide a strategy with which to improve the lung drug delivery while reducing systemic toxicity. The purpose of this study is to assess the safety of a regional aerosol approach to chemotherapy delivery in osteosarcoma-bearing dogs, and second, to evaluate the effect of gemcitabine on Fas expression in the pulmonary metastasis.
We examined the systemic and local effects of aerosol gemcitabine on lung and pulmonary metastasis in this relevant large-animal tumor model using serial laboratory and arterial blood gas analysis and histopathology and immunohistochemistry, respectively.
Results and Conclusions
Six hundred seventy-two 1-h doses of aerosol gemcitabine were delivered. The treatment was well tolerated by these subjects with osteosarcoma (n = 20). Aerosol-treated subjects had metastatic foci that demonstrated extensive, predominately central, intratumoral necrosis. Fas expression was decreased in pulmonary metastases compared to the primary tumor (p = 0.008). After aerosol gemcitabine Fas expression in the metastatic foci was increased compared to lung metastases before treatment (p = 0.0075), and even was higher than the primary tumor (p = 0.025). Increased apoptosis (TUNEL) staining was also detected in aerosol gemcitabine treated metastasis compared to untreated controls (p = 0.028). The results from this pivotal translational study support the concept that aerosol gemcitabine may be useful against pulmonary metastases of osteosarcoma. Additional studies that evaluate the aerosol route of administration of gemcitabine in humans should be safe and are warranted.
aerosol chemotherapy; gemcitabine; relapsed osteosarcoma; dog model
Osteosarcoma most commonly recurs in lung. Based on preliminary data on antitumor effects of GM-CSF in animal models, and promising phase 1 trials, we embarked on a feasibility study of inhaled granulocyte-macrophage colony stimulating factor (GM-CSF) in patients with first isolated pulmonary recurrence of osteosarcoma.
Forty-three eligible patients received inhaled GM-CSF at doses from 250-1750 μg twice daily on alternate weeks. Following two cycles, patients underwent thoracotomy to resect tumor and analyze pulmonary nodules for expression of Fas/Fas ligand (Fas/FasL), and presence of dendritic cells by immunostaining for CD1a, clusterin and S100. Following surgery, patients received 12 additional cycles of therapy on alternating weeks or until progression. Event free survival and survival, and feasibility of therapy delivery were evaluated.
Dose escalation to 1750 μg twice daily was feasible with no dose limiting toxicity. Mean scores for Fas /FasL in nodules from patients with bilateral recurrence who underwent unilateral thoracotomy pretreatment (using a scoring system of 0-3) were 1.3 and 0.88 respectively, compared to 0.78 and 0.62 in nodules resected following two cycles of therapy. Only 11 of 30 nodules post inhalation were positive for CD1a, 4 of 30 for S100 and 6 of 30 for clusterin. Event free and overall survival at 3 years were 7.8% and 35.4%, respectively.
Inhalation of GM-CSF at doses from 250-1750 μg twice daily on alternate weeks was feasible with low toxicity. However no detectable immunostimulatory effect in pulmonary metastases or improved outcome post relapse were seen.
osteosarcoma; inhalation therapy; GM-CSF
Antiretroviral chemoprophylaxis before exposure is a promising approach for the prevention of human immunodeficiency virus (HIV) acquisition.
We randomly assigned 2499 HIV-seronegative men or transgender women who have sex with men to receive a combination of two oral antiretroviral drugs, emtricitabine and tenofovir disoproxil fumarate (FTC–TDF), or placebo once daily. All subjects received HIV testing, risk-reduction counseling, condoms, and management of sexually transmitted infections.
The study subjects were followed for 3324 person-years (median, 1.2 years; maximum, 2.8 years). Of these subjects, 10 were found to have been infected with HIV at enrollment, and 100 became infected during follow-up (36 in the FTC–TDF group and 64 in the placebo group), indicating a 44% reduction in the incidence of HIV (95% confidence interval, 15 to 63; P = 0.005). In the FTC–TDF group, the study drug was detected in 22 of 43 of seronegative subjects (51%) and in 3 of 34 HIV-infected subjects (9%) (P<0.001). Nausea was reported more frequently during the first 4 weeks in the FTC–TDF group than in the placebo group (P<0.001). The two groups had similar rates of serious adverse events (P = 0.57).
Oral FTC–TDF provided protection against the acquisition of HIV infection among the subjects. Detectable blood levels strongly correlated with the prophylactic effect. (Funded by the National Institutes of Health and the Bill and Melinda Gates Foundation; ClinicalTrials.gov number, NCT00458393.)
Low academic achievement is common and is associated with adverse outcomes such as grade repetition, behavioural disorders and unemployment. The ability to accurately identify these children and intervene before they experience academic failure would be a major advance over the current 'wait to fail' model. Recent research suggests that a possible modifiable factor for low academic achievement is working memory, the ability to temporarily store and manipulate information in a 'mental workspace'. Children with working memory difficulties are at high risk of academic failure. It has recently been demonstrated that working memory can be improved with adaptive training tasks that encourage improvements in working memory capacity. Our trial will determine whether the intervention is efficacious as a selective prevention strategy for young children at risk of academic difficulties and is cost-effective.
This randomised controlled trial aims to recruit 440 children with low working memory after a school-based screening of 2880 children in Grade one. We will approach caregivers of all children from 48 participating primary schools in metropolitan Melbourne for consent. Children with low working memory will be randomised to usual care or the intervention. The intervention will consist of 25 computerised working memory training sessions, which take approximately 35 minutes each to complete. Follow-up of children will be conducted at 6, 12 and 24 months post-randomisation through child face-to-face assessment, parent and teacher surveys and data from government authorities. The primary outcome is academic achievement at 12 and 24 months, and other outcomes include child behaviour, attention, health-related quality of life, working memory, and health and educational service utilisation.
A successful start to formal learning in school sets the stage for future academic, psychological and economic well-being. If this preventive intervention can be shown to be efficacious, then we will have the potential to prevent academic underachievement in large numbers of at-risk children, to offer a ready-to-use intervention to the Australian school system and to build international research partnerships along the health-education interface, in order to carry our further studies of effectiveness and generalisability.
Despite advances in stent design, in-stent restenosis (ISR) remains a significant clinical problem. All implant metals exhibit corrosion, which results in release of metal ions. Stainless steel (SS), a metal alloy widely used in stents, releases ions to the vessel wall and induces reactive oxygen species, inflammation and fibroproliferative responses. The molecular mechanisms are unknown. TGF-β is known to be involved in the fibroproliferative responses of vascular smooth muscle cells (VSMCs) in restenosis, and TGF-β antagonists attenuate ISR. We hypothesized that SS ions induce the latent TGF-β activator, thrombospondin-1 (TSP1), through altered oxidative signaling to stimulate increased TGF-β activation and VSMC phenotype change.
VSMCs were treated with SS metal ion cocktails, and morphology, TSP1, extracellular matrix production, desmin and TGF-β activity were assessed by immunoblotting.
SS ions stimulate the synthetic phenotype, increased TGF-β activity, TSP1, increased extracellular matrix and downregulation of desmin in VSMCs. Furthermore, SS ions increase hydrogen peroxide and decrease cGMP-dependent protein kinase (PKG) signaling, a known repressor of TSP1 transcription. Catalase blocks SS ion attenuation of PKG signaling and increased TSP1 expression.
These data suggest that ions from stent alloy corrosion contribute to ISR through stimulation of TSP1-dependent TGF-β activation.
Restenosis; Smooth muscle cells; TGF-β; Thrombospondin-1; Stent corrosion; Hydrogen peroxide
Raltegravir's divalent metal ion chelating motif may predispose the drug to interactions with divalent cations. We determined whether a divalent cation-containing antacid interacted with raltegravir. Twelve HIV-1-seronegative subjects were enrolled in this randomized, prospective, crossover study of single-dose raltegravir (400 mg) with and without an antacid. Subjects underwent two intensive pharmacokinetic visits in the fasted state separated by a 5- to 12-day washout period. With simultaneous antacid administration, time to peak raltegravir concentration occurred 2 h sooner (P = 0.002) and there was a 67% lower raltegravir concentration at 12 h postdose (P < 0.0001) than with administration of raltegravir alone. The raltegravir area under the-concentration-time curve from 0 to 12 h and maximum concentration were unchanged with the addition of an antacid. Studies are needed to determine the clinical relevance of this interaction, whether it remains after multiple dosing to steady state, whether it is mitigated by temporal separation, and whether raltegravir interacts with divalent cation-containing vitamins, supplements, or foods.