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2.
Res Rep Health Eff Inst ; (195): 1-93, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31883240

RESUMO

INTRODUCTION: The United States and Western Europe have seen great improvements in air quality, presumably in response to various regulations curtailing emissions from the broad range of sources that have contributed to local, regional, and global pollution. Such regulations, and the ensuing controls, however, have not come without costs, which are estimated at tens of billions of dollars per year. These costs motivate accountability-related questions such as, to what extent do regulations lead to emissions changes? More important, to what degree have the regulations provided the expected human health benefits?Here, the impacts of specific regulations on both electricity generating unit (EGU) and on-road mobile sources are examined through the classical accountability process laid out in the 2003 Health Effects Institute report linking regulations to emissions to air quality to health effects, with a focus on the 1999-2013 period. This analysis centers on regulatory actions in the southeastern United States and their effects on health outcomes in the 5-county Atlanta metropolitan area. The regulations examined are largely driven by the 1990 Clean Air Act Amendments (C). This work investigates regulatory actions and controls promulgated on EGUs: the Acid Rain Program (ARP), the NOx Budget Trading Program (NBP), and the Clean Air Interstate Rule (CAIR) - and mobile sources: Tier 2 Gasoline Vehicle Standards and the 2007 Heavy Duty Diesel Rule. METHODS: Each step in the classic accountability process was addressed using one or more methods. Linking regulations to emissions was accomplished by identifying major federal regulations and the associated state regulations, along with analysis of individual facility emissions and control technologies and emissions modeling (e.g., using the U.S. Environmental Protection Agency's [U.S. EPA's] MOtor Vehicle Emissions Simulator [MOVES] mobile-source model). Regulators, including those from state environmental and transportation agencies, along with the public service commissions, play an important role in implementing federal rules and were involved along with other regional stakeholders in the study. We used trend analysis, air quality modeling, satellite data, and a ratio-of-ratios technique to investigate a critical current issue, a potential large bias in mobile-source oxides of nitrogen (NOx) emissions estimates.The second link, emissions-air quality relationships, was addressed using both empirical analyses as well as chemical transport modeling employing the Community Multiscale Air Quality (CMAQ) model. Kolmogorov-Zurbenko filtering accounting for day of the year was used to separate the air quality signal into long-term, seasonal, weekday-holiday, and short-term meteorological signals. Regression modeling was then used to link emissions and meteorology to ambient concentrations for each of the species examined (ozone [O3], particulate matter ≤ 2.5 µm in aerodynamic diameter [PM2.5], nitrogen dioxide [NO2], sulfur dioxide [SO2], carbon monoxide [CO], sulfate [SO4-2], nitrate [NO3-], ammonium [NH4+], organic carbon [OC], and elemental carbon [EC]). CMAQ modeling was likewise used to link emissions changes to air quality changes, as well as to further establish the relative roles of meteorology versus emissions change impacts on air quality trends. CMAQ and empirical modeling were used to investigate aerosol acidity trends, employing the ISORROPIA II thermodynamic equilibrium model to calculate pH based on aerosol composition. The relationships between emissions and meteorology were then used to construct estimated counterfactual air quality time series of daily pollutant concentrations that would have occurred in the absence of the regulations. Uncertainties in counterfactual air quality were captured by the construction of 5,000 pollutant time series using a Monte Carlo sampling technique, accounting for uncertainties in emissions and model parameters.Health impacts of the regulatory actions were assessed using data on cardiorespiratory emergency department (ED) visits, using patient-level data in the Atlanta area for the 1999-2013 period. Four outcome groups were chosen based on previous studies identifying associations with ambient air pollution: a combined respiratory disease (RD) category; the subgroup of RD presenting with asthma; a combined cardiovascular disease (CVD) category; and the subgroup of CVD presenting with congestive heart failure (CHF).Models were fit to estimate the joint effects of multiple pollutants on ED visits in a time-series framework, using Poisson generalized linear models accounting for overdispersion, with a priori model formulations for temporal and meteorological covariates and lag structures. Several parameterizations were considered for the joint-effects models, including different sets of pollutants and models with nonlinear pollutant terms and first-order interactions among pollutants. Use of different periods for parameter estimates was assessed, as associations between pollutant levels and ED visits varied over the study period. A 7-pollutant, nonlinear model with pollutant interaction terms was chosen as the baseline model and fitted using pollutant and outcome data from 1999-2005 before regulations might have substantially changed the toxicity of pollutant mixtures. In separate analyses, these models were fitted using pollutant and outcome data from the entire 1999-2013 study period. Daily counterfactual time series of pollutant concentrations were then input into the health models, and the differences between the observed and counterfactual concentrations were used to estimate the impacts of the regulations on daily counts of ED visits. To account for the uncertainty in both the estimation of the counterfactual time series of ambient pollutant levels and the estimation of the health model parameters, we simulated 5,000 sets of parameter estimates using a multivariate normal distribution based on the observed variance-covariance matrix, allowing for uncertainty at each step of the chain of accountability. Sensitivity tests were conducted to assess the robustness of the results. RESULTS: EGU NOx and SO2 emissions in the Southeast decreased by 82% and 83%, respectively, between 1999 and 2013, while mobile-source emissions controls led to estimated decreases in Atlanta-area pollutant emissions of between 61% and 93%, depending on pollutant. While EGU emissions were measured, mobile-source emissions were modeled. Our results are supportive of a potential high bias in mobile-source NOx and CO emissions estimates. Air quality benefits from regulatory actions have increased as programs have been fully implemented and have had varying impacts over different seasons. In a scenario that accounted for all emissions reductions across the period, observed Atlanta central monitoring site maximum daily 8-hour (MDA8h) O3 was estimated to have been reduced by controls in the summertime and increased in the wintertime, with a change in mean annual MDA8h O3 from 39.7 ppb (counterfactual) to 38.4 ppb (observed). PM2.5 reductions were observed year-round, with average 2013 values at 8.9 µg/m3 (observed) versus 19.1 µg/m3 (counterfactual). Empirical and CMAQ analyses found that long-term meteorological trends across the Southeast over the period examined played little role in the distribution of species concentrations, while emissions changes explained the decreases observed. Aerosol pH, which plays a key role in aerosol formation and dynamics and may have health implications, was typically very low (on the order of 1-2, but sometimes much lower), with little trend over time despite the stringent SO2 controls and SO42- reductions.Using health models fit from 1999-2005, emissions reductions from all selected pollution-control policies led to an estimated 55,794 cardiorespiratory disease ED visits prevented (i.e., fewer observed ED visits than would have been expected under counterfactual scenarios) - 52,717 RD visits, of which 38,038 were for asthma, and 3,057 CVD visits, of which 2,104 were for CHF - among the residents of the 5-county area over the 1999-2013 period, an area with approximately 3.5 million people in 2013. During the final two years of the study (2012-2013), when pollution-control policies were most fully implemented and the associated benefits realized, these policies were estimated to prevent 5.9% of the RD ED visits that would have occurred in the absence of the policies (95% interval estimate: -0.4% to 12.3%); 16.5% of the asthma ED visits (95% interval estimate: 7.5% to 25.1%); 2.3% of the CVD ED visits (95% interval estimate: -1.8% to 6.2%); and -.6% of the CHF ED visits (95% interval estimate: 26.3% to 10.4%). Estimates of ED visits prevented were generally lower when using health models fit for the entire 1999-2013 study period.Sensitivity analyses were conducted to show the impact of the choice of parameterization of the health models and to assess alternative definitions of the study area. When impacts were assessed for separate policy interventions, policies affecting emissions from EGUs, especially the ARP and the NBP, appeared to have had the greatest effect on prevention of RD and asthma ED visits. CONCLUSIONS: This study demonstrates the effectiveness of regulations on improving air quality and health in the southeastern United States. It also demonstrates the complexities of accountability assessments as uncertainties are introduced in each step of the classic accountability process. While accounting for uncertainties in emissions, air quality-emissions relationships, and health models does lead to relatively large uncertainties in the estimated outcomes due to specific regulations, overall the benefits of regulations have been substantial.

3.
J Public Health (Oxf) ; 39(1): 193-201, 2017 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-26968482

RESUMO

Background: A large proportion of health promotion campaign evaluation research has historically been conducted via telephone surveys. However, there are concerns about the continued viability of this form of surveying in providing relevant and representative data. Online surveys are an increasingly popular alternative, and as such there is a need to assess the comparability between data collected using the two different methods to determine the implications for longitudinal comparisons. The present study compared these survey modes in the context of health promotion evaluation research. Methods: Data were collected via computer-assisted telephone interviewing and an online panel. In total, 688 and 606 respondents aged between 14 and 45 years completed the online and telephone surveys, respectively. Results: Online respondents demonstrated higher awareness of the advertisement, rated the advertisement as more personally relevant and had better behavioural outcomes compared with the telephone respondents. Conclusion: The results indicate significant differences between the telephone and online surveys on most measures used to assess the effectiveness of a health promotion advertising campaign. Health promotion practitioners could consider the combination of both methods to overcome the deterioration in telephone survey response rates and the likely differences in respondent outcomes.


Assuntos
Promoção da Saúde/métodos , Internet , Neoplasias Cutâneas/prevenção & controle , Telecomunicações , Adolescente , Adulto , Feminino , Inquéritos Epidemiológicos , Humanos , Entrevistas como Assunto , Masculino , Pessoa de Meia-Idade , Telefone , Adulto Jovem
4.
Artigo em Inglês | MEDLINE | ID: mdl-27471429

RESUMO

This report reviews the study of open heavy-flavour and quarkonium production in high-energy hadronic collisions, as tools to investigate fundamental aspects of Quantum Chromodynamics, from the proton and nucleus structure at high energy to deconfinement and the properties of the Quark-Gluon Plasma. Emphasis is given to the lessons learnt from LHC Run 1 results, which are reviewed in a global picture with the results from SPS and RHIC at lower energies, as well as to the questions to be addressed in the future. The report covers heavy flavour and quarkonium production in proton-proton, proton-nucleus and nucleus-nucleus collisions. This includes discussion of the effects of hot and cold strongly interacting matter, quarkonium photoproduction in nucleus-nucleus collisions and perspectives on the study of heavy flavour and quarkonium with upgrades of existing experiments and new experiments. The report results from the activity of the SaporeGravis network of the I3 Hadron Physics programme of the European Union 7[Formula: see text] Framework Programme.

5.
Oncogene ; 34(16): 2061-71, 2015 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-24909179

RESUMO

Targeting HER2 with antibodies or small molecule inhibitors in HER2-positive breast cancer leads to improved survival, but resistance is a common clinical problem. To uncover novel mechanisms of resistance to anti-HER2 therapy in breast cancer, we performed a kinase open reading frame screen to identify genes that rescue HER2-amplified breast cancer cells from HER2 inhibition or suppression. In addition to multiple members of the MAPK (mitogen-activated protein kinase) and PI3K (phosphoinositide 3-kinase) signaling pathways, we discovered that expression of the survival kinases PRKACA and PIM1 rescued cells from anti-HER2 therapy. Furthermore, we observed elevated PRKACA expression in trastuzumab-resistant breast cancer samples, indicating that this pathway is activated in breast cancers that are clinically resistant to trastuzumab-containing therapy. We found that neither PRKACA nor PIM1 restored MAPK or PI3K activation after lapatinib or trastuzumab treatment, but rather inactivated the pro-apoptotic protein BAD, the BCl-2-associated death promoter, thereby permitting survival signaling through BCL-XL. Pharmacological blockade of BCL-XL/BCL-2 partially abrogated the rescue effects conferred by PRKACA and PIM1, and sensitized cells to lapatinib treatment. These observations suggest that combined targeting of HER2 and the BCL-XL/BCL-2 anti-apoptotic pathway may increase responses to anti-HER2 therapy in breast cancer and decrease the emergence of resistant disease.


Assuntos
Anticorpos Monoclonais Humanizados/uso terapêutico , Antineoplásicos/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Subunidades Catalíticas da Proteína Quinase Dependente de AMP Cíclico/fisiologia , Resistencia a Medicamentos Antineoplásicos/genética , Inibidores de Proteínas Quinases/uso terapêutico , Quinazolinas/uso terapêutico , Receptor ErbB-2/antagonistas & inibidores , Apoptose/efeitos dos fármacos , Subunidades Catalíticas da Proteína Quinase Dependente de AMP Cíclico/genética , Feminino , Perfilação da Expressão Gênica , Células HEK293 , Humanos , Lapatinib , Proteínas Quinases Ativadas por Mitógeno/genética , Fases de Leitura Aberta/genética , Fosfatidilinositol 3-Quinases/genética , Fosforilação , Proteínas Proto-Oncogênicas c-pim-1/genética , Trastuzumab , Proteína de Morte Celular Associada a bcl/antagonistas & inibidores , Proteína de Morte Celular Associada a bcl/metabolismo , Proteína bcl-X/antagonistas & inibidores
6.
Comput Methods Biomech Biomed Engin ; 17(15): 1671-84, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23405986

RESUMO

Patient-specific finite element models of the implanted proximal femur can be built from pre-operative computed tomography scans and post-operative X-rays. However, estimating three-dimensional positioning from two-dimensional radiographs introduces uncertainty in the implant position. Further, accurately measuring the thin cement mantle and the degree of cement-bone interdigitation from imaging data is challenging. To quantify the effect of these uncertainties in stem position and cement thickness, a sensitivity study was performed. A design-of-experiment study was implemented, simulating both gait and stair ascent. Cement mantle stresses and bone-implant interface strains were monitored. The results show that small variations in alignment affect the implant biomechanics, especially around the most proximal and most distal ends of the stem. The results suggest that implant position is more influential than cement thickness. Rotation around the medial-lateral axis is the dominant factor in the proximal zones and stem translations are the dominant factors around the distal tip.


Assuntos
Artroplastia de Quadril/métodos , Cimentos Ósseos/química , Fêmur/cirurgia , Prótese de Quadril , Quadril/fisiologia , Idoso , Fenômenos Biomecânicos , Substitutos Ósseos/química , Feminino , Análise de Elementos Finitos , Marcha , Humanos , Reprodutibilidade dos Testes , Estresse Mecânico
7.
Prev Sci ; 15(1): 12-21, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23408286

RESUMO

Despite the national push encouraging children to walk to school, little work has been done to examine what hazards children encounter on the route to school. This study examined the association between the presence of alcohol outlets on children's route to school and perceived safety on the route to school as well as exposure to alcohol, tobacco, and other drugs (ATOD). Data come from a community-based epidemiological study of 394 urban elementary school students. Participants' residential address, school location, and alcohol outlet data were geocoded and the route to school was mapped. The route to school layer and the geocoded alcohol outlet data were joined to determine the number of alcohol outlets children pass on the route to school. Logistic regression models estimated the association between the presence of alcohol outlets on the route to school, alcohol and drug exposure, and self-reported safety. Children with an alcohol outlet on the route to school were more likely to be offered ATOD (OR = 2.20, p = 0.02) as well as be exposed to drug selling (OR = 1.72, p = 0.02) and seeing people using drugs (OR = 1.93, p = 0.02). After adjusting for individual-level variables, the relationship between presence of alcohol outlets and being offered ATOD and seeing people using drugs remained significant. However, after adjusting for individual-level control variables and a proxy for the larger neighborhood context, the association between the presence of alcohol outlets and exposure to ATOD was no longer significant. As national campaigns are encouraging children to walk to school, it is essential to consider what children are exposed to on the route to school.


Assuntos
Consumo de Bebidas Alcoólicas/epidemiologia , Instituições Acadêmicas , Fumar/epidemiologia , Transtornos Relacionados ao Uso de Substâncias/epidemiologia , Adolescente , Baltimore , Feminino , Humanos , Drogas Ilícitas , Masculino , Modelos Estatísticos , Características de Residência , Fatores de Risco
8.
Med Eng Phys ; 33(3): 295-301, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21075032

RESUMO

Experimental testing is widely used to predict wear of total knee replacement (TKR) devices. Computational models cannot replace this essential in vitro testing, but they do have complementary strengths and capabilities, which make in silico models a valuable support tool for experimental wear investigations. For effective exploitation, these two separate domains should be closely corroborated together; this requires extensive data-sharing and cross-checking at every stage of simulation and testing. However, isolated deterministic corroborations provide only a partial perspective; in vitro testing is inherently variable, and relatively small changes in the environmental and kinematic conditions at the articulating interface can account for considerable variation in the reported wear rates. Understanding these variations will be key to managing uncertainty in the tests, resulting in a 'cleaner' investigation environment for further refining current theories of wear. This study demonstrates the value of probabilistic in silico methods by describing a specific, targeted corroboration of the AMTI knee wear simulator, using rigid body dynamics software models. A deterministic model of the simulator under displacement-control was created for investigation. Firstly, a large sample of experimental data (N>100) was collated, and a probabilistic computational study (N>1000 trials) was used to compare the kinetic performance envelopes for in vitro and in silico models, to more fully corroborate the mechanical model. Secondly, corresponding theoretical wear-rate predictions were compared to the experimentally reported wear data, to assess the robustness of current wear theories to uncertainty (as distinct from the mechanical variability). The results reveal a good corroboration for the physical mechanics of the wear test rig; however they demonstrate that the distributions for wear are not currently well-predicted. The probabilistic domain is found to be far more sensitive at distinguishing between different wear theories. As such we recommend that in future, researchers move towards probabilistic studies as a preferred framework for investigations into implant wear.


Assuntos
Artroplastia do Joelho/instrumentação , Simulação por Computador , Membro Posterior/cirurgia , Teste de Materiais , Algoritmos , Animais , Bovinos , Biologia Computacional , Peso Molecular , Polietileno/química , Incerteza
9.
Comput Methods Biomech Biomed Engin ; 13(6): 701-9, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-20162473

RESUMO

Explicit finite element (FE) and multi-body dynamics (MBD) models have been developed to evaluate total knee replacement (TKR) mechanics as a complement to experimental methods. In conjunction with these models, probabilistic methods have been implemented to predict performance bounds and identify important parameters, subject to uncertainty in component alignment and experimental conditions. Probabilistic methods, such as advanced mean value (AMV) and response surface method (RSM), provide an efficient alternative to the gold standard Monte Carlo simulation technique(MCST). The objective of the current study was to benchmark models from three platforms (two FE and one MBD) using various probabilistic methods by predicting the influence of alignment variability and experimental parameters on TKR mechanics in simulated gait. Predicted kinematics envelopes were on average about 2.6mm for tibial anterior-posterior translation, 2.98 for tibial internal­external rotation and 1.9 MPa for tibial peak contact pressure for the various platforms and methods. Based on this good agreement with the MCST, the efficient probabilistic techniques may prove useful in the fast evaluation of new implant designs, including considerations of uncertainty, e.g. misalignment.


Assuntos
Artroplastia do Joelho , Probabilidade , Fenômenos Biomecânicos , Análise de Elementos Finitos , Humanos , Método de Monte Carlo , Tíbia/fisiologia , Incerteza
10.
J Biomech ; 42(10): 1469-1474, 2009 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-19464013

RESUMO

The capability to predict in-vivo wear of knee replacements is a valuable pre-clinical analysis tool for implant designers. Traditionally, time-consuming experimental tests provided the principal means of investigating wear. Today, computational models offer an alternative. However, the validity of these models has not been demonstrated across a range of designs and test conditions, and several different formulas are in contention for estimating wear rates, limiting confidence in the predictive power of these in-silico models. This study collates and retrospectively simulates a wide range of experimental wear tests using fast rigid-body computational models with extant wear prediction algorithms, to assess the performance of current in-silico wear prediction tools. The number of tests corroborated gives a broader, more general assessment of the performance of these wear-prediction tools, and provides better estimates of the wear 'constants' used in computational models. High-speed rigid-body modelling allows a range of alternative algorithms to be evaluated. Whilst most cross-shear (CS)-based models perform comparably, the 'A/A+B' wear model appears to offer the best predictive power amongst existing wear algorithms. However, the range and variability of experimental data leaves considerable uncertainty in the results. More experimental data with reduced variability and more detailed reporting of studies will be necessary to corroborate these models with greater confidence. With simulation times reduced to only a few minutes, these models are ideally suited to large-volume 'design of experiment' or probabilistic studies (which are essential if pre-clinical assessment tools are to begin addressing the degree of variation observed clinically and in explanted components).


Assuntos
Análise de Falha de Equipamento/estatística & dados numéricos , Prótese do Joelho , Algoritmos , Fenômenos Biomecânicos , Simulação por Computador , Humanos , Técnicas In Vitro , Desenho de Prótese , Falha de Prótese
11.
J Epidemiol Community Health ; 63(6): 500-4, 2009 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19228684

RESUMO

BACKGROUND: Relationships between ambient air pollution levels during pregnancy and adverse pregnancy outcomes have been investigated using one of three analytic approaches: ambient pollution levels have been contrasted over space, time or both space and time. Although the three approaches share a common goal, to estimate the causal effects of pollution on pregnancy outcomes, they face different challenges with respect to confounding. METHODS: A framework based on counterfactual effect definitions to examine issues related to confounding in spatial, temporal, and spatial-temporal analyses of air pollution and pregnancy outcomes is presented, and their implications for inference are discussed. RESULTS: In spatial analyses, risk factors that are spatially correlated with pollution levels are confounders; the primary challenges relate to the availability and validity of risk factor measurements. In temporal analyses, where smooth functions of time are commonly used to control for confounding, concerns relate to the adequacy of control and the possibility that abrupt changes in risk might be systematically related to pollution levels. Spatial-temporal approaches are subject to challenges faced in both spatial and temporal analyses. CONCLUSION: Each approach faces different challenges with respect to the likely sources of confounding and the ability to control for that confounding because of differences in the type, availability, and quality of information required. Thoughtful consideration of these differences should help investigators select the analytic approach that best promotes the validity of their research.


Assuntos
Poluição do Ar/efeitos adversos , Resultado da Gravidez/epidemiologia , Poluição do Ar/análise , Fatores de Confusão Epidemiológicos , Monitoramento Ambiental/métodos , Monitoramento Epidemiológico , Feminino , Humanos , Exposição Materna/efeitos adversos , Gravidez
12.
J Dairy Sci ; 85(11): 2750-8, 2002 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-12487442

RESUMO

Low-moisture part-skim Mozzarella cheeses were manufactured from 2% fat milk and aged for 21 d. Treatments included cheeses made with one of three different strains of Lactobacillus delbrueckii ssp. bulgaricus in combination with a single strain of Streptococcus thermophilus. A fourth, control treatment consisted of cheeses made with only S. thermophilus. Although total proteolytic ability of these strains, as indicated by the o-phthaldialdehyde analysis, was similar in each of the three strains of L. bulgaricus, these strains exhibited different proteolytic specificities toward the peptide, alpha(s1)-CN (f 1-23). On the basis of their alpha(s1)-CN (f 1-23) cleavage patterns and a previously described classification, these strains were assigned to the groups I, III, and V. The objective of this study was to investigate the influence of lactobacilli proteolytic systems, based on specificity toward alpha(s1)-CN (f 1-23), on functionality of part-skim Mozzarella cheese. Moisture, fat, protein, salt-in-moisture, and moisture in nonfat substances content of cheeses made with groups I, III, and V strain were similar. Control cheese had a lower moisture content than did other treatments. Significant differences were observed in functional properties between cheeses manufactured using groups III and V strains. Cheeses made with groups I and III strains were similar in their meltability, hardness, cohesiveness, melt strength, and stretch quality. Meltability and cohesiveness increased with age, while melt strength and stretch quality decreased with age for all cheeses. Additionally, HPLC showed that total peak areas of water-soluble peptides derived from cleavage of alpha(s1)-CN (f 1-23) by different strains of lactobacilli could be highly correlated to meltability and stretch characteristics of cheeses made with those strains.


Assuntos
Queijo/microbiologia , Lactobacillus/metabolismo , Proteínas do Leite/metabolismo , Sequência de Aminoácidos , Animais , Queijo/análise , Manipulação de Alimentos/métodos , Microbiologia de Alimentos , Tecnologia de Alimentos , Indicadores e Reagentes/análise , Proteínas do Leite/análise , Proteínas do Leite/química , Dados de Sequência Molecular , Desnaturação Proteica , Distribuição Aleatória , Reologia , Streptococcus/metabolismo , Fatores de Tempo , Água , o-Ftalaldeído/análise
13.
Lett Appl Microbiol ; 34(6): 455-60, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-12028429

RESUMO

AIMS: To investigate the diversity in specificity of cell-bound extracellular proteinases in Lactobacillus helveticus and Lactobacillus delbrueckii subsp. bulgaricus. METHODS AND RESULTS: HPLC analysis of whole-cell preparations of 14 Lact. delbrueckii subsp. bulgaricus and eight Lact. helveticus strains incubated with alpha (s1)-casein (f 1-23) detected at least six distinct proteolytic patterns. Differences between groups were found in both the primary and secondary specificity toward alpha(s1)-casein (f 1-23) and its breakdown products. No correlation was found between the o-phthaldialdehyde (OPA) general proteolysis analysis and alpha(s1)-casein (f 1-23) cleavage profiles. CONCLUSIONS, SIGNIFICANCE AND IMPACT OF STUDY: Using the alpha(s1)-CN (f 1-23) method, six patterns of proteolysis were found in the dairy lactobacilli tested. Understanding the influence of Lactobacillus proteinase specificity on casein degradation should facilitate efforts to develop starter cultures that predictably improve the functional properties of Mozzarella cheese.


Assuntos
Endopeptidases/metabolismo , Lactobacillus/enzimologia , Cromatografia Líquida de Alta Pressão , Eletroforese Capilar , Especificidade por Substrato , o-Ftalaldeído/química
14.
Electrophoresis ; 22(8): 1510-7, 2001 May.
Artigo em Inglês | MEDLINE | ID: mdl-11386663

RESUMO

Milk protein is an important component of the human diet throughout much of the world. The ability to assess the relative composition and integrity of milk proteins or peptides in dairy foods or food ingredients is important because these molecules have a profound effect on product functionality and quality. This communication describes two capillary electrophoretic methods that are useful for the analysis of proteins and casein-derived peptides in cheese and milk products. One technique, which uses a buffer containing citrate/phosphate (pH 3.3), 4 M urea, and a polymeric additive in a coated capillary, is useful for qualitative and quantitative analysis of proteins and peptides in milk, cheese, and whey products. The second method employs a citrate/phosphate buffer (pH 2.8) and a bare silica capillary, and is well suited for the analysis of small, casein-derived peptides in aqueous cheese extracts.


Assuntos
Proteínas do Leite/análise , Peptídeos/análise , Animais , Queijo/análise , Eletroforese Capilar/métodos , Peso Molecular , Oxirredução
15.
J Hosp Infect ; 41(1): 23-8, 1999 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-9949961

RESUMO

Pseudobacteraemia might be responsible for up to 50% of all positive blood cultures and its early recognition is important in order to avoid unnecessary treatment with antibiotics and delay in the search for the true cause of the fever. We describe pseudobacteraemia outbreak of Pseudomonas fluorescens related to contaminated lithium heparin bottles in a paediatric ward. Twelve patients were involved in this outbreak from December 1996-January 1997. All patients had no clinical evidence of sepsis, nevertheless most children were treated with antibiotics. Blood collection bottles were suspected as source of pseudobacteraemia and only lithium heparin bottles were found to be contaminated with P. fluorescences indistinguishable from the blood isolates taken from these children. Withdrawal of these bottles led to the termination of the pseudobacteraemia. Following discussion with the manufacturer, the contaminated batch of lithium heparin bottles was sent back for testing, and replaced with bottles containing dried lithium heparin. A hazard report was sent to the Medical Devices Agency (MDA). In order to minimize the possibility of this problem occurring again, the manufacturer has informed MDA that all lithium heparin solution is to be filtered to 0.2 micron prior to issue, in order to minimize bacterial contamination. Continued monitoring after the pseudobacteraemia showed no isolates of P. fluorescens from the blood of paediatric patients.


Assuntos
Bacteriemia/transmissão , Infecção Hospitalar/transmissão , Embalagem de Medicamentos , Contaminação de Equipamentos , Heparina , Lítio , Infecções por Pseudomonas/transmissão , Pseudomonas fluorescens , Bacteriemia/epidemiologia , Bacteriemia/microbiologia , Criança , Pré-Escolar , Infecção Hospitalar/epidemiologia , Infecção Hospitalar/microbiologia , Feminino , Humanos , Lactente , Controle de Infecções/métodos , Masculino , Flebotomia , Infecções por Pseudomonas/epidemiologia , Infecções por Pseudomonas/microbiologia , Pseudomonas fluorescens/isolamento & purificação
16.
Neonatal Netw ; 16(2): 29-35, 1997 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-9087009

RESUMO

This study evaluated the effects of an occlusive (OpSite Flexigrid) dressing on bacterial growth over excoriated and the surrounding intact skin of eight premature infants. Cultures were obtained before placement and four days after dressing placement. An analysis of variance demonstrated significant increases in coagulase-negative Staphylococcus and overall total skin. No significant differences in bacterial growth occurred between intact skin underneath the dressing and that on the opposite side of the body post-dressing placement. Significant increases were found in bacterial concentrations for both intact and excoriated skin post-dressing placement. Small sample size and no between-subject design hinder generalization to the neonatal population.


Assuntos
Curativos Oclusivos , Pele/lesões , Pele/microbiologia , Análise de Variância , Pesquisa em Enfermagem Clínica , Contagem de Colônia Microbiana , Humanos , Recém-Nascido , Recém-Nascido Prematuro , Fatores de Tempo
17.
Phys Rev D Part Fields ; 52(6): 3653-3671, 1995 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-10019586
18.
Biochim Biophys Acta ; 1132(2): 154-60, 1992 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-1382605

RESUMO

Two human homologues of protein kinase C-epsilon (E1 and E2) were isolated from two distinct cDNA libraries. Sequence comparisons to PKC-epsilon cDNAs from several species indicated that each of these human epsilon clones contained cloning artifacts. Thus, a composite PKC-epsilon (E3) clone was derived from clones E1 and E2. Human PKC-epsilon (E3) has an overall sequence identity of 90-92% at the nucleotide level compared to the previously characterized mouse, rat and rabbit clones. At the amino acid level, the deduced human epsilon sequence shows a 98-99% identity with the mouse, rat and rabbit sequences. Expression of the human PKC-epsilon clone in Sf9 cells confirmed that the recombinant protein displayed protein kinase C activity and phorbol ester binding activity. The recombinant protein was also recognized by two distinct epsilon-specific polyclonal antibodies.


Assuntos
Proteína Quinase C/genética , Sequência de Aminoácidos , Sequência de Bases , Clonagem Molecular , DNA , Biblioteca Gênica , Histonas/metabolismo , Humanos , Dados de Sequência Molecular , Proteína Básica da Mielina/metabolismo , Forbóis/metabolismo , Proteína Quinase C/metabolismo , Proteína Quinase C-épsilon , Especificidade por Substrato
19.
Biochim Biophys Acta ; 1125(3): 321-9, 1992 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-1596521

RESUMO

Three phospholipid transfer proteins, namely proteins I, II and III, were purified from the rabbit lung cytosolic fraction. The molecular masses of phospholipid transfer proteins I, II and III are 32 kilodaltons (kDa), 22 kDa and 32 kDa, respectively; their isoelectric point values are 6.5, 7.0 and 6.8, respectively. Phospholipid transfer proteins I and III transferred phosphatidylcholine (PC) and phosphatidylinositol (PI) from donor unilamellar liposomes to acceptor multilamellar liposomes; protein II transferred PC but not PI. All the three phospholipid transfer proteins transferred phosphatidylethanolamine poorly and showed no tendency to transfer triolein. The transfer of [14C]PC from unilamellar liposomes to multilamellar liposomes facilitated by each protein was affected differently by the presence of acidic phospholipids in the PC unilamellar liposomes. In an equal molar ratio of acidic phospholipid and PC, phosphatidylglycerol (PG) reduced the activities of proteins I and III by 70% (P = 0.0004 and 0.0032, respectively) whereas PI and phosphatidylserine (PS) had an insignificant effect. In contrast, the protein II activity was stimulated 2-3-times more by either PG (P = 0.0024), PI (P = 0.0006) or PS (P = 0.0038). In addition, protein II transferred dioleoylPC (DOPC) about 2-times more effectively than dipalmitoylPC (DPPC) (P = 0.0002), whereas proteins I and III transferred DPPC 20-40% more effectively than DOPC but this was statistically insignificant. The markedly different substrate specificities of the three lung phospholipid transfer proteins suggest that these proteins may play an important role in sorting intracellular membrane phospholipids, possibly including lung surfactant phospholipids.


Assuntos
Proteínas de Transporte/metabolismo , Pulmão/química , Proteínas de Membrana/metabolismo , Ácidos Fosfatídicos/metabolismo , Proteínas de Transferência de Fosfolipídeos , 1,2-Dipalmitoilfosfatidilcolina/metabolismo , Animais , Radioisótopos de Carbono , Proteínas de Transporte/isolamento & purificação , Citosol/química , Marcação por Isótopo , Lipossomos/metabolismo , Proteínas de Membrana/isolamento & purificação , Fosfatidilcolinas/metabolismo , Fosfatidiletanolaminas/metabolismo , Fosfatidilgliceróis/metabolismo , Fosfatidilinositóis/metabolismo , Fosfatidilserinas/metabolismo , Coelhos , Especificidade por Substrato
20.
Am J Orthopsychiatry ; 62(2): 309-12, 1992 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-1580349

RESUMO

The effects of the trauma on the behavior of elementary-school children who had been held hostage or been closely involved with the hostage situation were investigated, as also were the effects on the lives of their families. Specific types of negative behavior exhibited by the children were identified by teachers and parents, and were found to be linked to the length of time for which the children had been held hostage.


Assuntos
Transtornos do Comportamento Infantil/diagnóstico , Acontecimentos que Mudam a Vida , Adolescente , Criança , Transtornos do Comportamento Infantil/etiologia , Feminino , Seguimentos , Humanos , Masculino , Pais/psicologia , Transtornos de Estresse Pós-Traumáticos/etiologia , Transtornos de Estresse Pós-Traumáticos/psicologia , Transtornos de Estresse Pós-Traumáticos/reabilitação , Inquéritos e Questionários , Ensino
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