518 research outputs found
Cardiovascular disease prevention by sports: myth or reality?
Low levels of physical activity and fitness substantially increase risk of several chronic diseases, reduce longevity, and lead to loss of function. The strength and relation of inactivity to health problems and the high prevalence of sedentary habits in most countries of the world make lack of exercise a major public health problem. Fortunately, there is now good consensus regarding public health recommendations for physical activity from many important medical, scientific, and public health organizations. Recent research on physical activity interventions provides additional approaches to helping sedentary adults become more physically active
Physical Activity and Neighborhood Resources in High School Girls
Background - Physical activity behavior is influenced by a person\u27s physical environment, but few studies have used objective measures to study the influences of the physical environment on physical activity behavior in youth. The purpose of this study was to examine the relationship between selected neighborhood physical activity resources and physical activity levels in high school girls.
Methods - Participants were students in schools that had participated in a large physical activity intervention trial. The 3-Day Physical Activity Recall was completed by 1506 12th-grade girls. Data on physical activity facilities and resources in the participating communities were collected using a variety of methods. Physical activity resources within a 0.75-mile street-network buffer around each girl\u27s home were counted using ArcGIS, version 9.1. Mixed-model regression models were used to determine if there was a relationship between three physical activity variables and the number of physical activity resources within the 0.75-mile buffer. Data were collected in 2002-2003 and analyzed in 2006-2007.
Results - On average, 3.5 physical activity resources (e.g., schools, parks, commercial facilities) were located within the 0.75-mile street-network buffer. Thirty-six percent of the girls had no physical activity resource within the buffer. When multiple physical activity resources were considered, the number of commercial physical activity facilities was significantly associated with reported vigorous physical activity, and the number of parks was associated with total METs in white girls.
Conclusion - Multiple physical activity resources within a 0.75-mile street-network buffer around adolescent girls\u27 homes are associated with physical activity in those girls. Several types of resources are associated with vigorous physical activity and total activity in adolescent girls. Future studies should examine the temporal and causal relationships between the physical environment, physical activity, and health outcomes related to physical activity
Mechanistic studies of cytotoxicity induced by a Portuguese propolis extract, using Saccharomyces cerevisiae as eukaryotic cell model
Propolis is a natural complex mixture produced by honey bees (particularly Apis mellifera
L.) by collecting exudates from various plant sources. Characterized by a plethora of
chemicals, propolis is generally rich in flavonoids, phenolic acids and terpene derivatives,
bioactive compounds associated to it’s antimicrobial, anti-inflammatory, antimutagenic
and antioxidant activities1
. Previous work had shown that the ethanol extract of a sample
from the Portuguese region of Beira Alta exhibited unique dual genotoxic and
antigenotoxic effects using the yeast S. cerevisiae eukaryotic model2
. In this work we
prepared two ethanol extracts (EE) of propolis samples from Pereiro (P) - Beira Alta -
collected in 2010 (P10.EE) and 2017 (P17.EE) to investigate the mechanisms of
cytotoxicity and genotoxicity using specific S. cerevisiae mutants. While P17.EE didn’t
show any toxic effect, yeast cells exposed to P10.EE showed a considerable decreased
viability along time, assessed by colony-forming units. Interestingly, the oxidative stress
response-defective mutant yap1 was more resistant than the wild type, suggesting that
this cytotoxic effect was not mediated by oxidative stress. P.EE’s genotoxicity was also
analysed by the nucleus-cytosolic translocation of NHP6A protein, considered a marker
of necrosis. P10.EE induced NHP6A protein translocation to the cytoplasm, observed by
fluorescence microscopy, suggesting that cytotoxicity of this extract was indeed mediated
by necrosis. Although P17.EE didn’t seem to induce necrotic cell death, both extracts
induced plasma membrane integrity loss, assessed by flow cytometry, using propidium
iodide as marker. As recently observed for erythroleukemic cells with Brazilian propolis3
,
here we present the first evidence that also Portuguese propolis have necrotic-mediated
cytotoxicity in yeast cellsEDER/COMPETE/POCI–
Operational Competitiveness and Internationalization Programme, under Project POCI-01-0145-
FEDER-006958 and National Funds by FCT - Portuguese Foundation for Science and
Technology, under the project UID/AGR/04033/201
Enhancing bacterial photodynamic inactivation through combined action of potassium iodide and cationic phthalocyanines
Infectious diseases remain a leading cause of death all around the world. Over the last three decades, the alarming and escalating emergence of antibiotic-resistant bacterial strains has caused some concern among the scientific community [1,2]. Photodynamic inactivation (PDI) emerges as an alternative for inactivating microorganisms, including bacteria [1–3]. The use of phthalocyanine (Pc) derivatives as photosensitizers (PS) in PDI has already proven effectiveness against various microorganisms [4]. Moreover, the addition of KI as a coadjutant can, in certain circumstances, enhance the efficiency of neutral, negative, and positively charged PS against Gram-negative and Gram-positive bacteria [2,4]. In this study will be demonstrated the effect of KI in PDI of E. coli and S. aureus with cationic Pcs bearing tris(trimethylammoniummethyl) or pyridinium-pyrazolyl groups.info:eu-repo/semantics/publishedVersio
Synthesis and evaluation of tumor cell growth inhibition of Methyl 3-Amino-6-[(hetero)arylethynyl]thieno[3,2-b]pyridine-2-carboxylates: structure-activity relationships, effects on the cell cycle and apoptosis
The methyl 3-amino-6-bromothieno[3,2-b]pyridine-2-carboxylate, recently reported by some of us, was reacted in Sonogashira couplings with several (hetero)arylacetylenes. The growth inhibitory activity of the novel methyl 3-amino-6-[(hetero)arylethynyl]thieno[3,2-b]pyridine-2-carboxylates obtained was evaluated on three human tumor cell lines (MCF-7, NCI-H460, A375-C5). The para-methoxyphenyl and the ortho and para-aminophenyl derivatives were the most promising compounds, and their effects were further studied regarding alterations in the normal cell cycle distribution and induction of apoptosis in the NCI-H460 cell line. All three compounds altered cell cycle distribution and the ortho-aminophenyl derivative was further shown to induce apoptosis in the same cell line.Associate Laboratory of the Portuguese Ministry of Science, Technology and Higher
EducationFundação para a Ciência e a Tecnologia (FCT) - (Bruker Avance III 400) REDE/1517/RMN/2005, PTDC/QUI-QUI/111060/2009, SFRH/BD/29274/2006, SFRH/BPD/29112/2006European Social Fund
Charge effect on the photoinactivation of Gram-negative and Gram-positive bacteria by cationic meso-substituted porphyrins
<p>Abstract</p> <p>Background</p> <p>In recent times photodynamic antimicrobial therapy has been used to efficiently destroy Gram (+) and Gram (-) bacteria using cationic porphyrins as photosensitizers. There is an increasing interest in this approach, namely in the search of photosensitizers with adequate structural features for an efficient photoinactivation process. In this study we propose to compare the efficiency of seven cationic porphyrins differing in <it>meso</it>-substituent groups, charge number and charge distribution, on the photodynamic inactivation of a Gram (+) bacterium (<it>Enterococcus faecalis</it>) and of a Gram (-) bacterium (<it>Escherichia coli</it>). The present study complements our previous work on the search for photosensitizers that might be considered good candidates for the photoinactivation of a large spectrum of environmental microorganisms.</p> <p>Results</p> <p>Bacterial suspension (10<sup>7 </sup>CFU mL<sup>-1</sup>) treated with different photosensitizers concentrations (0.5, 1.0 and 5.0 μM) were exposed to white light (40 W m<sup>-2</sup>) for a total light dose of 64.8 J cm<sup>-2</sup>. The most effective photosensitizers against both bacterial strains were the Tri-Py<sup>+</sup>-Me-PF and Tri-Py<sup>+</sup>-Me-CO<sub>2</sub>Me at 5.0 μM with a light fluence of 64.8 J cm<sup>-2</sup>, leading to > 7.0 log (> 99,999%) of photoinactivation. The tetracationic porphyrin also proved to be a good photosensitizer against both bacterial strains. Both di-cationic and the monocationic porphyrins were the least effective ones.</p> <p>Conclusion</p> <p>The number of positive charges, the charge distribution in the porphyrins' structure and the <it>meso</it>-substituent groups seem to have different effects on the photoinactivation of both bacteria. As the Tri-Py<sup>+</sup>-Me-PF porphyrin provides the highest log reduction using lower light doses, this photosensitizer can efficiently photoinactivate a large spectrum of environmental bacteria. The complete inactivation of both bacterial strains with low light fluence (40 W m<sup>-2</sup>) means that the photodynamic approach can be applied to wastewater treatment under natural light conditions which makes this technology cheap and feasible in terms of the light source.</p
Total soluble solids from banana: evaluation and optimization of extraction parameters
Banana, an important component in the diet of the global population, is one of the
most consumed fruits in the world. This fruit is also very favorable to industry processes (e.g.,
fermented beverages) due to its rich content on soluble solids and minerals, with low acidity.
The main objective of this work was to evaluate the influence of factors such as banana weight
and extraction time during a hot aqueous extraction process on the total soluble solids content
of banana. The extract is to be used by the food and beverage industries. The experiments were
performed with 105 mL of water, considering the moisture of the ripe banana (65%). Total
sugar concentrations were obtained in a beer analyzer and the result expressed in degrees Plato
(°P, which is the weight of the extract or the sugar equivalent in 100 g solution at 20 °C), aiming
at facilitating the use of these results by the beverage industries. After previous studies of
characterization of the fruit and of ripening performance, a 22 full-factorial star design was
carried out, and a model was developed to describe the behavior of the dependent variable
(total soluble solids) as a function of the factors (banana weight and extraction time),
indicating as optimum conditions for extraction 38.5 g of banana at 39.7 min.Gabinete de Relações Internacionais da Ciência e do Ensino Superior (GRICES), Portugal.Fundação de Amparo à Pesquisa do Estado de São Paulo (Fapesp), Brasil.Coordenação para Aperfeiçoamento do Ensino Superior (CAPES), Brasil.Fundação para a Ciência e Tecnologia (FCT), Portugal
Cysteine as a Multifaceted Player in Kidney, the Cysteine-Related Thiolome and Its Implications for Precision Medicine
Funding Information: This research was supported by Fundação para a Ciência e Tecnologia (PTDC/MED-TOX/30418/2017) and iNOVA4Health (UID/Multi/04462/2013). M.J.C., D.G.F.F. and J.M. were supported by FCT (PhD grant SFRH/BD/131331/2017, PhD grant PD/BD/135484/2018 and postdoctoral contract PTDC/MED-TOX/30418/2017, respectively).In this review encouraged by original data, we first provided in vivo evidence that the kidney, comparative to the liver or brain, is an organ particularly rich in cysteine. In the kidney, the total availability of cysteine was higher in cortex tissue than in the medulla and distributed in free reduced, free oxidized and protein-bound fractions (in descending order). Next, we provided a comprehensive integrated review on the evidence that supports the reliance on cysteine of the kidney beyond cysteine antioxidant properties, highlighting the relevance of cysteine and its renal metabolism in the control of cysteine excess in the body as a pivotal source of metabolites to kidney biomass and bioenergetics and a promoter of adaptive responses to stressors. This view might translate into novel perspectives on the mechanisms of kidney function and blood pressure regulation and on clinical implications of the cysteine-related thiolome as a tool in precision medicine.publishersversionpublishe
Defining Accelerometer Thresholds for Activity Intensities in Adolescent Girls
Purpose - To derive a regression equation that estimates metabolic equivalent (MET) from accelerometer counts, and to define thresholds of accelerometer counts that can be used to delineate sedentary, light, moderate, and vigorous activity.
Methods - Seventy-four healthy 8th grade girls, age 13-14 yr, were recruited from urban areas of Baltimore, MD, Minneapolis/St. Paul, MN, and Columbia, SC, to participate in the study. Accelerometer and oxygen consumption (VO2) data for 10 activities that varied in intensity from sedentary (e.g., TV watching) to vigorous (e.g., running) were collected. While performing these activities, the girls wore two accelerometers, a heart rate monitor and a Cosmed K4b2 portable metabolic unit for measurement of VO2. A random-coefficients model was used to estimate the relationship between accelerometer counts and VO2. Activity thresholds were defined by minimizing the false positive and false negative classifications.
Results - The activities provided a wide range in VO2 (3-36 mL·kg-1·min-1) with a correspondingly wide range in accelerometer counts (1-3928 counts·30 s-1). The regression line for MET score versus counts was MET=2.01+0.00171 (counts·30 s-1) (mixed model R2=0.84, SEE=1.36). A threshold of 1500 counts·30 s-1 defined the lower end of the moderate intensity (~4.6 METs) range of physical activity. That cutpoint distinguished between slow and brisk walking, and gave the lowest number of false positive and false negative classifications. The threshold ranges for sedentary, light, moderate, and vigorous physical activity were found to be 0-50, 51-1499, 1500-2600, and \u3e2600 counts·30 s-1, respectively.
Conclusion - The developed equation and these activity thresholds can be used for prediction of MET score from accelerometer counts and participation in various intensities of physical activity in adolescent girls
A multibiomarker approach in the clam Ruditapes decussatus to assess the impact of pollution in the Ria Formosa lagoon, South Coast of Portugal
The Ria Formosa lagoon is an ecosystem whose water quality reflects the anthropogenic influence upon
the surrounding areas. In this lagoon, the clam Ruditapes decussatus has a great economical importance
and has been widely used as a biomonitor. A multibiomarker approach (d-aminolevulinic acid dehy-
dratase, metallothionein, lipid peroxidation, acetylcholinesterase, alkali-labile phosphates, DNA damage)
was applied to assess the environmental quality of this ecosystem and the accumulation of contaminants
and their potential adverse effects on clams. Clams were sampled in different shellfish beds in the period
between July 2007 and December 2008 and abiotic parameters (temperature, salinity, pH and dissolved
oxygen of seawater and organic matter in the sediment), condition index, metals (Cd, Cu, Zn, Ni, Pb), TBTs
and PAHs concentrations were measured in clam tissues. Data was integrated using Principal Component
Analyses and biomarker indices: IBR (Integrated Biomarker Response) and HSI (Health Status Index). This
multibiomarker approach enabled discrimination of a time and space trend between sites with different
degrees of anthropogenic contamination, identifying one of them (site 2) as the most stressful and
summer months as the most critical period for clams due to an increase of environmental stress
(anthropogenic pressure along with extreme environmental conditions, e.g. temperature, dissolved
oxygen, organic matter in the sediments, etc). The selected biomarkers provided an integrated response
to assess the environmental quality of the system, proving to be a useful approach when complex
mixtures of contaminants occur
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