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1.
Mol Pharm ; 21(6): 2937-2948, 2024 Jun 03.
Article in English | MEDLINE | ID: mdl-38750625

ABSTRACT

Polymers are extensively used for the realization of drug delivery systems across multiple scales, from nanomedicines to microparticles and macroscopic implantable devices, for their favorable biodegradation profiles and tunable physicochemical features. The accurate quantification of the polymer content is key to finely controlling drug loading and release and ensuring reproducibility, yet it continues to be a major challenge in the design and development of delivery systems. In this study, we introduce a novel protocol based on the PULCON technique to quantify, with a routine NMR spectroscopy analysis, the precise concentration of polymers in various delivery systems. Specifically, the PULCON protocol is applied to characterize the physicochemical and pharmaceutical properties of nanoparticles, microparticles, and implantable devices realized by combining three extensively used polymers, namely, poly(lactic-co-glycolic acid) (PLGA), poly(vinyl alcohol) (PVA), and poly(ethylene glycol) (PEG). Without using internal calibration procedures, in a single step, the PULCON protocol precisely quantifies the concentration of each polymer and the drug content. This approach can be readily implemented on standard NMR spectrometers, enabling accurate characterization of drug delivery systems and facilitating their effective development.


Subject(s)
Drug Delivery Systems , Magnetic Resonance Spectroscopy , Polyethylene Glycols , Polylactic Acid-Polyglycolic Acid Copolymer , Magnetic Resonance Spectroscopy/methods , Drug Delivery Systems/methods , Polylactic Acid-Polyglycolic Acid Copolymer/chemistry , Polyethylene Glycols/chemistry , Polyvinyl Alcohol/chemistry , Polymers/chemistry , Nanoparticles/chemistry , Drug Liberation , Drug Carriers/chemistry , Particle Size
2.
Ann Ig ; 35(2): 202-212, 2023.
Article in English | MEDLINE | ID: mdl-35788249

ABSTRACT

Abstract: School Active Breaks are short bouts of physical activity (5-15 minutes) conducted by appropriately trained teachers and delivered during or between curricular lessons. They are a good strategy to counteract sedentary behaviors, and a growing body of evidence shows that they can represent also a tool to promote and improve health, school wellbeing and academic achievements. On 19 February 2022, the Working Group on Movement Sciences for Health of the Italian Society of Hygiene, Preventive Medicine and Public Health organized an Awareness Day on the effectiveness, usefulness and feasibility of School Active Breaks, opened to teachers, educators, school leaders, pediatricians, personnel from Departments of Prevention and Public Health and Health Policy-makers. During the event, the testimonies about the experiences already carried out in Italy showed that School Active Breaks are an effective intervention that each school can easily include in its educational offer and apply in any context.


Subject(s)
Health Promotion , Sedentary Behavior , Humans , School Health Services , Exercise , Schools
4.
J Intellect Disabil Res ; 65(5): 464-488, 2021 05.
Article in English | MEDLINE | ID: mdl-33719112

ABSTRACT

BACKGROUND: Classroom-based active breaks can help typically developing children reduce sitting, increase physical activity and improve cognitive functions and on-task behaviour. Yet, this strategy has not been tested in children with intellectual disability (ID) - a population who are insufficiently active. This study aimed to investigate the effects of a 5-week active breaks intervention on cognitive functions and on-task behaviour in schoolchildren with ID. METHODS: Twenty-four children, aged between 8 and 12 years (37.5% girls), were recruited. Children's cognitive functions (response inhibition, lapses of attention, interference and working memory) were measured at baseline and end of trial using computer-based tests. Sitting, standing and movement patterns were assessed with inclinometers, and on-task behaviour was directly observed in the classroom before and after active breaks, at baseline, mid-trial and end of trial. Linear mixed models were used to investigate the intervention effects on cognitive functions and sedentary patterns; generalised linear mixed models were used to analyse on-task behaviour data. RESULTS: A significant time × group interaction was found for working memory favouring the intervention (B = 11.56, 95% confidence interval [1.92, 21.21]). No significant effects were found in relation to the other measures of children's cognition or on-task behaviour. Stepping time and bouts of sitting were positively affected. CONCLUSIONS: Classroom-based active breaks can increase physical activity and reduce sedentary behaviour in children with ID and might also benefit their working memory. Further research is required to clarify the effects on cognition and to investigate whether this strategy has other benefits in this population.


Subject(s)
Intellectual Disability , Child , Cognition , Female , Humans , Male , Pilot Projects , Schools , Sedentary Behavior
5.
Mol Syst Biol ; 14(4): e7390, 2018 04 04.
Article in English | MEDLINE | ID: mdl-29618636

ABSTRACT

Populations of isogenic cells often respond coherently to signals, despite differences in protein abundance and cell state. Previously, we uncovered processes in the Saccharomyces cerevisiae pheromone response system (PRS) that reduced cell-to-cell variability in signal strength and cellular response. Here, we screened 1,141 non-essential genes to identify 50 "variability genes". Most had distinct, separable effects on strength and variability of the PRS, defining these quantities as genetically distinct "axes" of system behavior. Three genes affected cytoplasmic microtubule function: BIM1, GIM2, and GIM4 We used genetic and chemical perturbations to show that, without microtubules, PRS output is reduced but variability is unaffected, while, when microtubules are present but their function is perturbed, output is sometimes lowered, but its variability is always high. The increased variability caused by microtubule perturbations required the PRS MAP kinase Fus3 and a process at or upstream of Ste5, the membrane-localized scaffold to which Fus3 must bind to be activated. Visualization of Ste5 localization dynamics demonstrated that perturbing microtubules destabilized Ste5 at the membrane signaling site. The fact that such microtubule perturbations cause aberrant fate and polarity decisions in mammals suggests that microtubule-dependent signal stabilization might also operate throughout metazoans.


Subject(s)
MAP Kinase Signaling System/genetics , Microtubule Proteins/genetics , Microtubules/genetics , Single-Cell Analysis , Adaptor Proteins, Signal Transducing/genetics , Cell Cycle Proteins/genetics , Microtubules/metabolism , Mitogen-Activated Protein Kinases/genetics , Pheromones/genetics , Saccharomyces cerevisiae/genetics , Saccharomyces cerevisiae Proteins/genetics , Signal Transduction/genetics
6.
Sci Rep ; 7(1): 10157, 2017 08 31.
Article in English | MEDLINE | ID: mdl-28860643

ABSTRACT

The molecular details of local plant response against Xanthomonas translucens infection is largely unknown. Moreover, there is no knowledge about effects of the pathogen on the root's transcriptome and proteome. Therefore, we investigated the global gene and protein expression changes both in leaves and roots of wheat (Triticum aestivum) 24 h post leaf infection of X. translucens. This simultaneous analysis allowed us to obtain insight into possible metabolic rearrangements in above- and belowground tissues and to identify common responses as well as specific alterations. At the site of infection, we observed the implication of various components of the recognition, signaling, and amplification mechanisms in plant response to the pathogen. Moreover, data indicate a massive down-regulation of photosynthesis and confirm the chloroplast as crucial signaling hub during pathogen attack. Notably, roots responded as well to foliar attack and their response significantly differed from that locally triggered in infected leaves. Data indicate that roots as a site of energy production and synthesis of various secondary metabolites may actively influence the composition and colonisation level of root-associated microbes. Finally, our results emphasize the accumulation of jasmonic acid, pipecolic acid and/or the downstream mediator of hydrogen peroxide as long distal signals from infected leaves to roots.


Subject(s)
Proteome/genetics , Transcriptome , Triticum/genetics , Xanthomonas/pathogenicity , Chloroplasts/metabolism , Chloroplasts/microbiology , Cyclopentanes/metabolism , Oxylipins/metabolism , Pipecolic Acids/metabolism , Plant Leaves/metabolism , Plant Leaves/microbiology , Plant Roots/metabolism , Plant Roots/microbiology , Proteome/metabolism , Triticum/microbiology
7.
J Nutr Health Aging ; 21(3): 284-291, 2017.
Article in English | MEDLINE | ID: mdl-28244568

ABSTRACT

OBJECTIVE: To examine the relationship between regional and whole body fat accumulation and core cognitive executive functions. DESIGN: Cross-sectional study. SETTINGS AND PARTICIPANTS: 78 healthy men and women aged between 65 and 75 years recruited through consumer's database. MEASUREMENTS: DXA measured percentage total body fat, android, gynoid distribution and android/gynoid ratio; inhibition and working memory updating through Random Number Generation test and cognitive flexibility by Trail Making test. First-order partial correlations between regional body fat and cognitive executive function were computed partialling out the effects of whole body fat. Moderation analysis was performed to verify the effect of gender on the body fat-cognition relationship. RESULTS: Results showed a differentiated pattern of fat-cognition relationship depending on fat localization and type of cognitive function. Statistically significant relationships were observed between working memory updating and: android fat (r = -0.232; p = 0.042), gynoid fat (r = 0.333; p = 0.003) and android/gynoid ratio (r = -0.272; p = 0.017). Separating genders, the only significant relationship was observed in females between working memory updating and gynoid fat (r = 0.280; p = 0.045). In spite of gender differences in both working memory updating and gynoid body fat levels, moderation analysis did not show an effect of gender on the relationship between gynoid fat and working memory updating. CONCLUSIONS: Results suggest a protective effect of gynoid body fat and a deleterious effect of android body fat. Although excessive body fat increases the risk of developing CDV, metabolic and cognitive problems, maintaining a certain proportion of gynoid fat may help prevent cognitive decline, particularly in older women. Guidelines for optimal body composition maintenance for the elderly should not target indiscriminate weight loss, but weight maintenance through body fat/lean mass control based on non-pharmacological tools such as physical exercise, known to have protective effects against CVD risk factors and age-related cognitive deterioration.


Subject(s)
Adipose Tissue/metabolism , Body Fat Distribution , Cognition/physiology , Cognitive Dysfunction/physiopathology , Executive Function/physiology , Obesity/metabolism , Absorptiometry, Photon/methods , Aged , Anthropometry/methods , Body Mass Index , Body Weight , Cross-Sectional Studies , Exercise , Female , Humans , Male , Methyltestosterone/blood , Risk Factors
8.
Biomed Res Int ; 2016: 5812092, 2016.
Article in English | MEDLINE | ID: mdl-28053985

ABSTRACT

Physical and cognitive training seem to counteract age-related decline in physical and mental function. Recently, the possibility of integrating cognitive demands into physical training has attracted attention. The purpose of this study was to evaluate the effects of twelve weeks of designed physical-cognitive training on executive cognitive function and gait performance in older adults. Thirty-six healthy, active individuals aged 72.30 ± 5.84 years were assigned to two types of physical training with major focus on physical single task (ST) training (n = 16) and physical-cognitive dual task (DT) training (n = 20), respectively. They were tested before and after the intervention for executive function (inhibition, working memory) through Random Number Generation and for gait (walking with/without negotiating hurdles) under both single and dual task (ST, DT) conditions. Gait performance improved in both groups, while inhibitory performance decreased after exercise training with ST focus but tended to increase after training with physical-cognitive DT focus. Changes in inhibition performance were correlated with changes in DT walking performance with group differences as a function of motor task complexity (with/without hurdling). The study supports the effectiveness of group exercise classes for older individuals to improve gait performance, with physical-cognitive DT training selectively counteracting the age-related decline in a core executive function essential for daily living.


Subject(s)
Accidental Falls/prevention & control , Exercise Therapy , Gait/physiology , Walking/physiology , Aged , Aged, 80 and over , Attention/physiology , Female , Humans , Male , Postural Balance/physiology , Psychomotor Performance
9.
Neuroscience ; 298: 211-9, 2015 Jul 09.
Article in English | MEDLINE | ID: mdl-25907444

ABSTRACT

The association between a fit body and a fit brain in children has led to a rise of behavioral and neuroscientific research. Yet, the relation of cardiorespiratory fitness on premotor neurocognitive preparation with early visual processing has received little attention. Here, 41 healthy, lower and higher fit preadolescent children were administered a modified version of the Eriksen flanker task while electroencephalography (EEG) and behavioral measures were recorded. Event-related potentials (ERPs) locked to the stimulus onset with an earlier than usual baseline (-900/-800 ms) allowed investigation of both the usual post-stimulus (i.e., the P1, N1 and P2) as well as the pre-stimulus ERP components, such as the Bereitschaftspotential (BP) and the prefrontal negativity (pN component). At the behavioral level, aerobic fitness was associated response accuracy, with higher fit children being more accurate than lower fit children. Fitness-related differences selectively emerged at prefrontal brain regions during response preparation, with larger pN amplitude for higher than lower fit children, and at early perceptual stages after stimulus onset, with larger P1 and N1 amplitudes in higher relative to lower fit children. Collectively, the results suggest that the benefits of being aerobically fit appear at the stage of cognitive preparation prior to stimulus presentation and the behavioral response during the performance of a task that challenges cognitive control. Further, it is likely that enhanced activity in prefrontal brain areas may improve cognitive control of visuo-motor tasks, allowing for stronger proactive inhibition and larger early allocation of selective attention resources on relevant external stimuli.


Subject(s)
Cognition/physiology , Evoked Potentials, Visual/physiology , Follicle Stimulating Hormone, beta Subunit/physiology , Intention , Physical Fitness/physiology , Protein Precursors/physiology , Visual Perception/physiology , Analysis of Variance , Brain Mapping , Child , Electroencephalography , Female , Humans , Male , Neuropsychological Tests , Photic Stimulation , Reaction Time
10.
Front Genet ; 6: 346, 2015.
Article in English | MEDLINE | ID: mdl-26734059

ABSTRACT

The yeast two-hybrid (Y2H) system exploits host cell genetics in order to display binary protein-protein interactions (PPIs) via defined and selectable phenotypes. Numerous improvements have been made to this method, adapting the screening principle for diverse applications, including drug discovery and the scale-up for proteome wide interaction screens in human and other organisms. Here we discuss a systematic workflow and analysis scheme for screening data generated by Y2H and related assays that includes high-throughput selection procedures, readout of comprehensive results via next-generation sequencing (NGS), and the interpretation of interaction data via quantitative statistics. The novel assays and tools will serve the broader scientific community to harness the power of NGS technology to address PPI networks in health and disease. We discuss examples of how this next-generation platform can be applied to address specific questions in diverse fields of biology and medicine.

11.
Metab Eng ; 25: 238-47, 2014 Sep.
Article in English | MEDLINE | ID: mdl-25073011

ABSTRACT

D-xylonate is a potential platform chemical which can be produced by engineered Saccharomyces cerevisiae strains. In order to address production constraints in more detail, we analysed the role of lactone ring opening in single cells and populations. Both D-xylono-γ-lactone and D-xylonate were produced when the Caulobacter crescentus xylB (D-xylose dehydrogenase) was expressed in S. cerevisiae, with or without co-expression of xylC (D-xylonolactonase), as seen by (1)H NMR. XylC facilitated rapid opening of the lactone and more D-xylonate was initially produced than in its absence. Using in vivo(1)H NMR analysis of cell extracts, culture media and intact cells we observed that the lactone and linear forms of D-xylonic acid were produced, accumulated intracellularly, and partially exported within 15-60min of D-xylose provision. During single-cell analysis of cells expressing the pH sensitive fluorescent probe pHluorin, pHluorin fluorescence was gradually lost from the cells during D-xylonate production, as expected for cells with decreasing intracellular pH. However, in the presence of D-xylose, only 9% of cells expressing xylB lost pHluorin fluorescence within 4.5h, whereas 99% of cells co-expressing xylB and xylC lost fluorescence, a large proportion of which also lost vitality, during this interval. Loss of vitality in the presence of D-xylose was correlated to the extracellular pH, but fluorescence was lost from xylB and xylC expressing cells regardless of the extracellular condition.


Subject(s)
Metabolic Flux Analysis/methods , Models, Biological , Saccharomyces cerevisiae/metabolism , Sugar Acids/metabolism , Xylosidases/metabolism , Computer Simulation , Gene Expression Regulation, Enzymologic/physiology , Gene Expression Regulation, Fungal/physiology , Signal Transduction/physiology
12.
Lupus ; 23(10): 1066-8, 2014 Sep.
Article in English | MEDLINE | ID: mdl-24786782

ABSTRACT

Neuropsychiatric manifestations are serious and frequent complications of systemic lupus erythematous (SLE). Catatonia is a neuropsychiatric disorder characterized by motor disturbance (including waxy flexibility and catalepsy), stupor, excitement, negativism, mutism, echopraxia and echolalia. Catatonia associated with SLE has been only rarely reported, especially in children. Here we present a case of a 14-year-old patient encountered in consultation-liaison psychiatry who presented catatonia associated with SLE. Her catatonia was refractory to treatment with pulse methylprednisolone, intravenous cyclophosphamide and rituximab. The patient responded to a combined therapy of electroconvulsive therapy and benzodiazepines. The present case suggests that although rarely reported, catatonia seen in the background of SLE should be promptly identified and treated to reduce the morbidity.


Subject(s)
Catatonia/therapy , Electroconvulsive Therapy , Lupus Vasculitis, Central Nervous System/therapy , Adolescent , Benzodiazepines/therapeutic use , Catatonia/diagnosis , Catatonia/etiology , Catatonia/psychology , Combined Modality Therapy , Female , Humans , Lupus Vasculitis, Central Nervous System/complications , Lupus Vasculitis, Central Nervous System/diagnosis , Lupus Vasculitis, Central Nervous System/psychology , Treatment Outcome
13.
Appl Environ Microbiol ; 79(24): 7569-82, 2013 Dec.
Article in English | MEDLINE | ID: mdl-24038690

ABSTRACT

Organic acids derived from engineered microbes can replace fossil-derived chemicals in many applications. Fungal hosts are preferred for organic acid production because they tolerate lignocellulosic hydrolysates and low pH, allowing economic production and recovery of the free acid. However, cell death caused by cytosolic acidification constrains productivity. Cytosolic acidification affects cells asynchronously, suggesting that there is an underlying cell-to-cell heterogeneity in acid productivity and/or in resistance to toxicity. We used fluorescence microscopy to investigate the relationship between enzyme concentration, cytosolic pH, and viability at the single-cell level in Saccharomyces cerevisiae engineered to synthesize xylonic acid. We found that cultures producing xylonic acid accumulate cells with cytosolic pH below 5 (referred to here as "acidified"). Using live-cell time courses, we found that the probability of acidification was related to the initial levels of xylose dehydrogenase and sharply increased from 0.2 to 0.8 with just a 60% increase in enzyme abundance (Hill coefficient, >6). This "switch-like" relationship likely results from an enzyme level threshold above which the produced acid overwhelms the cell's pH buffering capacity. Consistent with this hypothesis, we showed that expression of xylose dehydrogenase from a chromosomal locus yields ∼20 times fewer acidified cells and ∼2-fold more xylonic acid relative to expression of the enzyme from a plasmid with variable copy number. These results suggest that strategies that further reduce cell-to-cell heterogeneity in enzyme levels could result in additional gains in xylonic acid productivity. Our results demonstrate a generalizable approach that takes advantage of the cell-to-cell variation of a clonal population to uncover causal relationships in the toxicity of engineered pathways.


Subject(s)
Carboxylic Acids/metabolism , Carboxylic Acids/toxicity , Saccharomyces cerevisiae/enzymology , Saccharomyces cerevisiae/metabolism , Carbohydrate Dehydrogenases/metabolism , Cytosol/chemistry , Hydrogen-Ion Concentration , Microbial Viability/drug effects , Microscopy, Fluorescence , Saccharomyces cerevisiae/chemistry , Saccharomyces cerevisiae/drug effects
14.
Public Health ; 126(9): 740-8, 2012 Sep.
Article in English | MEDLINE | ID: mdl-22769595

ABSTRACT

OBJECTIVES: Drug supply and demand indicators have mainly been analysed without triangulating information on environmental drug availability and consumption. This study proposes an approach to analyse the prevalence of illicit drug consumption together with indirect indicators of drug supply. STUDY DESIGN: Ecological study correlating cocaine seizure data and consumption prevalence estimates at local level, using Italian provinces as the unit of analysis. METHODS: The amount of cocaine seized in proportion to the number of potential consumers was computed at Italian provincial level from the 2005 database of the Italian Central Directorate for Anti-Drug Services. Indicators of consumption prevalence, at provincial level, in 15-16-year-old students from the 2005 European School Survey Project on Alcohol and Other Drugs (ESPAD) and 15-54-year-old respondents from the 2005 Italian Population Survey on Alcohol and Drugs (IPSAD) were correlated with the population-adjusted amount of total seizures and seizures of different sizes. ESPAD data were also regressed on seizure data after controlling for the prediction accrued by socio-economic variables that might cause covariation of seizure and consumption prevalence data. Regression-predicted prevalence values were computed and correlated with the ESPAD prevalence data for the following year. RESULTS: There was a weak general correlation between the population-adjusted total seizure and IPSAD prevalence indicators, but not ESPAD prevalence indicators. In contrast, ESPAD data were more strongly correlated with small seizures. The regression model yielded significant variance in prevalence data (18% and 23% in small and large provinces, respectively) explained by small seizures, and this remained after removing the percentage of variance explained by socio-economic factors and (particularly) education level. A moderate correlation was found between seizure-based predicted values of consumption prevalence and ESPAD values for the following year. CONCLUSIONS: Associating prevalence estimates in adolescents and cocaine seizure data at local level, after 'purifying' the data from trafficking- and wholesale-related large seizures, may represent a starting point for a geo-referenced, seizure-based analysis of initiation into cocaine consumption. This approach may support the collaboration between enforcement and health systems, helping to establish empirical regularities to be translated into useful information for local planners of drug prevention policies in areas at greater risk of increasing incidence.


Subject(s)
Cocaine-Related Disorders/epidemiology , Cocaine , Drug and Narcotic Control/statistics & numerical data , Adolescent , Adult , Data Collection , Female , Humans , Italy/epidemiology , Male , Middle Aged , Prevalence , Young Adult
15.
Proc Natl Acad Sci U S A ; 109(10): 3874-8, 2012 Mar 06.
Article in English | MEDLINE | ID: mdl-22355134

ABSTRACT

Organismal fitness depends on the ability of gene networks to function robustly in the face of environmental and genetic perturbations. Understanding the mechanisms of this stability is one of the key aims of modern systems biology. Dissecting the basis of robustness to mutation has proven a particular challenge, with most experimental models relying on artificial DNA sequence variants engineered in the laboratory. In this work, we hypothesized that negative regulatory feedback could stabilize gene expression against the disruptions that arise from natural genetic variation. We screened yeast transcription factors for feedback and used the results to establish ROX1 (Repressor of hypOXia) as a model system for the study of feedback in circuit behaviors and its impact across genetically heterogeneous populations. Mutagenesis experiments revealed the mechanism of Rox1 as a direct transcriptional repressor at its own gene, enabling a regulatory program of rapid induction during environmental change that reached a plateau of moderate steady-state expression. Additionally, in a given environmental condition, Rox1 levels varied widely across genetically distinct strains; the ROX1 feedback loop regulated this variation, in that the range of expression levels across genetic backgrounds showed greater spread in ROX1 feedback mutants than among strains with the ROX1 feedback loop intact. Our findings indicate that the ROX1 feedback circuit is tuned to respond to perturbations arising from natural genetic variation in addition to its role in induction behavior. We suggest that regulatory feedback may be an important element of the network architectures that confer mutational robustness across biology.


Subject(s)
DNA Mutational Analysis , Repressor Proteins/genetics , Saccharomyces cerevisiae Proteins/genetics , Saccharomyces cerevisiae/genetics , Computational Biology/methods , Flow Cytometry , Genes, Fungal , Genetic Variation , Genomics , Green Fluorescent Proteins/metabolism , Hypoxia , Microscopy, Fluorescence/methods , Models, Genetic , Open Reading Frames , Saccharomyces cerevisiae/metabolism , Sequence Analysis, DNA , Transcription Factors/metabolism
16.
Scand J Med Sci Sports ; 19(3): 412-8, 2009 Jun.
Article in English | MEDLINE | ID: mdl-18466184

ABSTRACT

To assess whether an enrichment of the coordinative demands of physical education (PE) during the curricular time may more efficiently improve coordinative abilities than the traditional PE program. One hundred and fifty-two middle school students aged 11-12 years were randomly assigned either to an experimental (n=77) or to a traditional (n=75) PE program lasting 5 months. The experimental intervention was structured in different modules focused on co-ordination abilities. Pre- and post-intervention tests assessed students' fitness (1 mile run/walk, curl-up, flexed arm hang, trunk lift, sit and reach, 30 m run, standing long jump, basketball forward throw) and motor co-ordination abilities (four field tests of kinesthetic discrimination and response orientation ability). After the intervention period, both groups showed a significant increment in most fitness tests. However, only the experimental group showed a significant improvement or a significantly more pronounced improvement than the control group in coordinative performances. The results show that both experimental and traditional PE interventions lead to increase physical fitness levels, but only the experimental one also improves coordinative abilities. Thus, focusing on a multivariate PE approach linking co-ordination and fitness training seems to add quality to students' experiences without reducing their effectiveness in terms of physical fitness.


Subject(s)
Physical Education and Training/organization & administration , Physical Fitness/physiology , Psychomotor Performance/physiology , Child , Curriculum , Female , Humans , Italy , Male , Program Evaluation
17.
IET Syst Biol ; 2(5): 222-33, 2008 Sep.
Article in English | MEDLINE | ID: mdl-19045818

ABSTRACT

One goal of systems biology is to understand how genome-encoded parts interact to produce quantitative phenotypes. The Alpha Project is a medium-scale, interdisciplinary systems biology effort that aims to achieve this goal by understanding fundamental quantitative behaviours of a prototypic signal transduction pathway, the yeast pheromone response system from Saccharomyces cerevisiae. The Alpha Project distinguishes itself from many other systems biology projects by studying a tightly bounded and well-characterised system that is easily modified by genetic means, and by focusing on deep understanding of a discrete number of important and accessible quantitative behaviours. During the project, the authors have developed tools to measure the appropriate data and develop models at appropriate levels of detail to study a number of these quantitative behaviours. The authors have also developed transportable experimental tools and conceptual frameworks for understanding other signalling systems. In particular, the authors have begun to interpret system behaviours and their underlying molecular mechanisms through the lens of information transmission, a principal function of signalling systems. The Alpha Project demonstrates that interdisciplinary studies that identify key quantitative behaviours and measure important quantities, in the context of well-articulated abstractions of system function and appropriate analytical frameworks, can lead to deeper biological understanding. The authors' experience may provide a productive template for systems biology investigations of other cellular systems.


Subject(s)
Models, Biological , Pheromones/metabolism , Proteome/metabolism , Research/trends , Saccharomyces cerevisiae Proteins/metabolism , Saccharomyces cerevisiae/metabolism , Signal Transduction/physiology , Computer Simulation , Protein Interaction Mapping/methods
18.
Nature ; 456(7223): 755-61, 2008 Dec 11.
Article in English | MEDLINE | ID: mdl-19079053

ABSTRACT

Haploid Saccharomyces cerevisiae yeast cells use a prototypic cell signalling system to transmit information about the extracellular concentration of mating pheromone secreted by potential mating partners. The ability of cells to respond distinguishably to different pheromone concentrations depends on how much information about pheromone concentration the system can transmit. Here we show that the mitogen-activated protein kinase Fus3 mediates fast-acting negative feedback that adjusts the dose response of the downstream system response to match the dose response of receptor-ligand binding. This 'dose-response alignment', defined by a linear relationship between receptor occupancy and downstream response, can improve the fidelity of information transmission by making downstream responses corresponding to different receptor occupancies more distinguishable and reducing amplification of stochastic noise during signal transmission. We also show that one target of the feedback is a previously uncharacterized signal-promoting function of the regulator of G-protein signalling protein Sst2. Our work suggests that negative feedback is a general mechanism used in signalling systems to align dose responses and thereby increase the fidelity of information transmission.


Subject(s)
Feedback, Physiological/physiology , Mitogen-Activated Protein Kinases/metabolism , Pheromones/metabolism , Saccharomyces cerevisiae Proteins/metabolism , Saccharomyces cerevisiae/physiology , Signal Transduction , Dose-Response Relationship, Drug , GTPase-Activating Proteins/metabolism , Pheromones/pharmacology , Protein Binding , Saccharomyces cerevisiae/drug effects , Saccharomyces cerevisiae/metabolism , Signal Transduction/drug effects
19.
Diabetologia ; 50(12): 2591-9, 2007 Dec.
Article in English | MEDLINE | ID: mdl-17901943

ABSTRACT

AIMS/HYPOTHESIS: Podocyte loss by apoptosis, in addition to favouring progression of established diabetic nephropathy, has been recently indicated as an early phenomenon triggering the initiation of glomerular lesions. This study aimed to assess the rate of glomerular cell death and its relationship with renal functional, structural and molecular changes in rats with experimental diabetes. METHODS: Male Sprague-Dawley rats with streptozotocin-induced diabetes and coeval non-diabetic control animals were killed at 7 days and at 2, 4 and 6 months for the assessment of apoptosis, renal function, renal structure and the expression of podocyte markers and apoptosis- and cell cycle-related proteins. RESULTS: Glomerular cell apoptosis was significantly increased in diabetic vs non-diabetic rats at 4 months and to an even greater extent at 6 months, with podocytes accounting for 70% of apoptosing cells. The increase in apoptosis was preceded by increases in proteinuria, albuminuria and mean glomerular and mesangial areas, and by reductions in glomerular cell density and content of synaptopodin and Wilms' tumour protein-1. It coincided with the development of mesangial expansion and glomerular sclerosis, and with the upregulation/activation both of tumour protein p53, which increased progressively throughout the study, and of p21 (also known as cyclin-dependent kinase inhibitor 1A, CIP1 and WAF1), which peaked at 4 months and decreased thereafter. CONCLUSIONS/INTERPRETATION: Glomerular cell (podocyte) apoptosis is not an early feature in the course of experimental diabetic glomerulopathy, since it is preceded by glomerular hypertrophy, which may decrease glomerular cell density to the point of inducing compensatory podocyte hypertrophy. This is associated with reduced podocyte protein expression (podocytopathy) and proteinuria, and ultimately results in apoptotic cell loss (podocytopenia), driving progression to mesangial expansion and glomerular sclerosis.


Subject(s)
Apoptosis/physiology , Diabetes Mellitus, Experimental/complications , Diabetes Mellitus, Experimental/physiopathology , Diabetic Nephropathies/etiology , Kidney Glomerulus/physiology , Podocytes/physiology , Streptozocin , Albuminuria/etiology , Animals , Blood Glucose/metabolism , Body Weight/physiology , Cell Cycle/genetics , Creatinine/blood , Diabetes Mellitus, Experimental/blood , Diabetes Mellitus, Experimental/metabolism , Diabetic Nephropathies/blood , Genes, p53 , Kidney Glomerulus/pathology , Male , Microfilament Proteins/metabolism , Podocytes/pathology , Proteinuria/etiology , Rats , Rats, Sprague-Dawley
20.
Diabetologia ; 50(9): 1997-2007, 2007 Sep.
Article in English | MEDLINE | ID: mdl-17611735

ABSTRACT

AIMS/HYPOTHESIS: AGEs have been implicated in renal disease associated with ageing, diabetes and other age-related disorders. Reactive oxygen species (ROS) promote formation of AGEs, which cause AGE-receptor-mediated ROS generation with activation of signalling pathways leading to tissue injury and further AGE accumulation. ROS generation is regulated by the Src homology 2 domain-containing transforming protein C1 (Shc1) isoform p66(Shc), whose deletion has been shown to protect from tissue injury induced by ageing, diabetes, hyperlipidaemia and ischaemia-reperfusion by preventing oxidative stress. This study was aimed at assessing the role of p66(Shc) in the modulation of oxidative stress and oxidant-dependent renal injury induced by AGEs. METHODS: For 10 weeks, male p66 (shc) knockout (KO) and wild-type (WT) mice were injected with 60 microg/day albumin modified or unmodified by N epsilon-(carboxymethyl) lysine (CML). Mice were then killed for the assessment of renal function and structure, as well as systemic and renal tissue oxidative stress. RESULTS: Upon CML injection, KO mice, in contrast to WT mice, showed no or only mild forms of proteinuria, glomerular hypertrophy, mesangial expansion, glomerular sclerosis, renal/glomerular cell apoptosis and extracellular matrix upregulation. Moreover, KO mice had lower circulating and tissue AGEs than WT mice and unchanged plasma isoprostane 8-epi-prostaglandin-F(2alpha) levels, renal/glomerular CML, 4-hydroxy-2-nonenal, AGE receptor and NAD(P)H oxidase 4 (NOX4) content (and expression of the corresponding genes), and nuclear factor kappaB activation (NFkappaB). Mesangial cells from KO mice exposed to CML showed no or slight increase in ROS levels and NFkappaB activation, again at variance with WT cells. CONCLUSIONS/INTERPRETATION: These data indicate that p66(Shc) participates in the pathogenesis of AGE-dependent glomerulopathy by mediating AGE-induced tissue injury and further AGE formation through ROS-dependent mechanisms involving NFkappaB activation and upregulation of Nox4 expression and NOX4 production.


Subject(s)
Adaptor Proteins, Signal Transducing/deficiency , Adaptor Proteins, Signal Transducing/genetics , Glomerular Mesangium/pathology , Kidney Diseases/pathology , Kidney Diseases/prevention & control , Kidney Glomerulus/pathology , Receptors, Immunologic/physiology , Animals , DNA Primers , Genotype , Immunohistochemistry , Kidney Glomerulus/physiopathology , Mice , Mice, Inbred Strains , NF-kappa B/metabolism , Reactive Oxygen Species/metabolism , Receptor for Advanced Glycation End Products , Shc Signaling Adaptor Proteins , Src Homology 2 Domain-Containing, Transforming Protein 1
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