1,797 research outputs found

    Assessment of diagnostic value of dipyridamole testing in angina pectoris.

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    Summary: In order to assess the diagnostic value of dipyridamole (D) testing, we studied the responses of 34 patients with chest pain and 10 normal subjects. Blood pressure and 12-lead ECG were recorded during and after intravenous infusion of 0.6 mg/kg dipyridamole for 10 minutes. Coronary arteriography and maximal or symptom-limited exercise tests were performed in the 34 patients with chest pain. During infusion 13 patients presented ischemic ST changes and 5 with anginal pain only. The latter group had normal coronary arteries. Among the 13 patients with ischemic ST changes, 7 had at least two critical coronary stenoses and the remaining 6 had no coronary lesions. Dipyridamole tests showed poor sensitivity (44%) and specificity (39%) with respect to coronary arteriography. The relatively high number of positive responses in subjects with normal coronary arteries indicates that the coronary steal phenomenon is not the sole cause of "ischemic" response to the drug. Indirect indexes of myocardial oxygen consumption were higher in patients with a positive response to drug infusion than in those with a negative response; however the value of rate-pressure product at infusion end never reached that observed at ischemic threshold during exercise testing in the same patient. This suggests that neither can oxygen consumption increase be considered as entirely responsible for ischemic response to dipyridamole. In conclusion dipyridamole test cannot be proposed for predicting critical coronary stenoses

    Serum concentrations of beta-hexachlorocyclohexane in groups of the Italian general population: a human biomonitoring study

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    Because of its persistence and toxicological profile, beta-hexachlorocyclohexane (β-HCH) has been proposed for inclusion in the Stockholm Convention on persistent organic pollutants (POPs). Although the use of technical HCH, which is the primary source of β-HCH in the environment, has been banned in the EU in 1978 and progressively at a global level, β-HCH is still detectable in the general environment worldwide. Human exposure mostly occurs via food and may be of concern in areas where illegal use and/or improper disposal of stockpiles occurred and locally grown food is consumed. Exposure of the Italian general population to β-HCH has been poorly characterised. Lack of human biomonitoring data severely hinders the ability to interpret potential increases in exposure related to situations of environmental risk. We carried out a human biomonitoring study aimed to provide baseline information on background exposure of the Italian general population to this pollutant. For this purpose, we analysed 116 serum samples from groups of subjects of both sex from the general population residing in three Italian towns at different latitudes. Serum concentrations of β-HCH resulted to be comprised between 1.64 and 300 ng/g fat, with a median value of 18.0 ng/g fat and a 90th percentile of 65.9 ng/g fat. The serum concentrations detected are in line with those detected in most Western European countries

    Perfluorooctanesulfonate and perfluorooctanoic acid exposures of the Italian general population

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    The serum concentrations of perfluorooctanesulfonate (PFOS) and perfluorooctanoic acid (PFOA) were determined in 230 subjects of the Italian general population. Participants were enrolled in 2008 in two Italian towns (Brescia, Northern Italy, and Rome, Central Italy) and belonged to the three age ranges: 20-35. years, 36-50. years, and 51-65. years.PFOS and PFOA were quantified by HPLC interfaced to a mass spectrometer operating in the electrospray negative mode. Data were acquired using multiple reaction monitoring (MRM). The isotope dilution technique was applied throughout.The median serum concentrations of all participants were 6.31ngg-1 and 3.59ngg-1 for PFOS and PFOA, respectively, and the pertinent 90th percentiles were 12.38 and 6.92.Men had higher concentrations of PFOS and PFOA than women, regardless of age. The differences were statistically significant in the 20-35 and 36-50. years groups, but not in the 51-65 group.An increase of PFOS and PFOA serum concentrations with age was observed. The Median test showed a statistically significant difference (p≪0.01) between the three age groups for both PFOS and PFOA when applied to the entire dataset (males and females). When the test was applied to the groups of males and females separately, a significant difference was observed for females (p≪0.005) but not for males (p>0.1).The observed strong correlation between PFOS and PFOA concentrations suggests same or similar exposure routes. © 2010 Elsevier Ltd

    Life cycle assessment of roads: Exploring research trends and harmonization challenges

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    The transparency, heterogeneity and hypotheses considered in the calculation of the environmental impacts of roads remain as barriers in the identification of low-carbon solutions. To overcome this gap, the study presents an analysis of 94 papers obtained in a systematic literature review of the Scopus, Science direct, Mendeley, Springer Link, and Web of Science databases. From a total of 417 road case studies, only 18% were found to be fully transparent, reproducible, and likely to present reliable results. The road design parameters of the speed limit were provided in 11% of cases and the average annual daily traffic data were provided in 42%. Limited data were found for the dimensions of road elements such as the number (77%) and width of lanes (33%), shoulders (15%), footpaths (5%), berm (1%) or foreslope (4%). The source of the life cycle inventory was presented in 57% of the case studies, impact assessment method was indicated in 22%, and the software utilized was stated in 50%. Lack of information was observed in the description of the type of materials employed in road projects. In addition, the large heterogeneity in the definitions of the functional unit, system boundary and in the reference study period of repair, replacement, rehabilitation or end-of-life for both flexible and rigid pavement does not support the identification of the most environmentally friendly solution. Based on results of the analsis,several recommendations for design parameters and life cycle assessment aspects are proposed to support a harmonized calculation of the environmental impacts of road projects.publishedVersio

    Chronic consumption of fructose rich soft drinks alters tissue lipids of rats

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    <p>Abstract</p> <p>Background</p> <p>Fructose-based diets are apparently related to the occurrence of several metabolic dysfunctions, but the effects of the consumption of high amounts of fructose on body tissues have not been well described. The aim of this study was to analyze the general characteristics and the lipid content of different tissues of rats after chronic ingestion of a fructose rich soft drink.</p> <p>Methods</p> <p>Forty-five Wistar rats were used. The rats were divided into three groups (n = 15) and allowed to consume water (C), light Coca Cola <sup>® </sup>(L) or regular Coca Cola<sup>® </sup>(R) as the sole source of liquids for eight weeks.</p> <p>Results</p> <p>The R group presented significantly higher daily liquid intake and significantly lower food intake than the C and L groups. Moreover, relative to the C and L groups, the R group showed higher triglyceride concentrations in the serum and liver. However, the L group animals presented lower values of serum triglycerides and cholesterol than controls.</p> <p>Conclusions</p> <p>Based on the results, it can be concluded that daily ingestion of a large amount of fructose- rich soft drink resulted in unfavorable alterations to the lipid profile of the rats.</p

    Infant mortality: comparison between two birth cohorts from Southeast and Northeast, Brazil

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    OBJECTIVE: To obtain population estimates and profile risk factors for infant mortality in two birth cohorts and compare them among cities of different regions in Brazil. METHODS: In Ribeirão Preto, southeast Brazil, infant mortality was determined in a third of hospital live births (2,846 singleton deliveries) in 1994. In São Luís, northeast Brazil, data were obtained using systematic sampling of births stratified by maternity unit (2,443 singleton deliveries) in 1997-1998. Mothers answered standardized questionnaires shortly after delivery and information on infant deaths was retrieved from hospitals, registries and the States Health Secretarys' Office. The relative risk (RR) was estimated by Poisson regression. RESULTS: In São Luís, the infant mortality rate was 26.6/1,000 live births, the neonatal mortality rate was 18.4/1,000 and the post-neonatal mortality rate was 8.2/1,000, all higher than those observed in Ribeirão Preto (16.9, 10.9 and 6.0 per 1,000, respectively). Adjusted analysis revealed that previous stillbirths (RR=3.67 vs 4.13) and maternal ageOBJETIVO: Obter estimativas populacionais e fatores de risco de mortalidade infantil em coortes de nascimentos e comparar esses fatores entre cidades de diferentes regiões do País. MÉTODOS: Em Ribeirão Preto, SP, a mortalidade infantil foi avaliada em 1/3 dos nascidos vivos hospitalares (2.846 partos únicos) em 1994. Em São Luís, MA, foi feita amostragem sistemática de partos estratificada por maternidade (2.443 partos únicos) em 1997/98. As mães responderam a questionários padronizados logo após o parto e as informações sobre os óbitos foram coletadas nos hospitais, nos cartórios e nas secretarias estaduais de saúde. Risco relativo (RR) e intervalo de confiança de 95% foram estimados pela regressão de Poisson. RESULTADOS: O coeficiente de mortalidade infantil (CMI) em São Luís foi 26,6/1.000 nascidos vivos, o coeficiente de mortalidade neonata (CMN)l 18,4/1.000 e o coeficiente de mortalidade pós-neonatal (CMPN) 8,2/1.000, valores superiores aos de Ribeirão Preto, com CMI 16,9/1.000, CMN 10,9/1.000,CMPN 6,0/1.000. Na análise ajustada, nas duas cidades, natimorto prévio (RR=3,67 vs 4,13) e idade matern

    Validação da versão portuguesa do questionário de eficácia clínica e prática baseada em evidências

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    Introduction: Currently, the importance of a clinical practice based on the best available evidence justifies the development of investigation to construct a situational diagnosis that allows to identify in different contexts of care, barriers, attitudes and practices towards an evidence-based nursing. Objective: In this investigation we aim to identify barriers regarding the adoption of an Evidence Based Practice (EBP) in different care settings and describe the main nurse’s attitudes and practices in relation to PBE. Method: We developed a cross-sectional study in a local health unit in the north of Portugal including nurses working in a hospital and in several primary health care settings. Data collection occurred in two distinct stages: between December 2010 and March 2011 and between March and July 2012 Through a convenience sample we applied the Portuguese version of the "Attitudes Towards Evidence-Based Practice Questionnaire " to 345 participants, the rate of response of 70.7% (n = 244). We proceed to univariate and descriptive statistics and performed the t Student and the chi-square (χ2) tests. Results: Nurses demonstrated a positive belief in supporting practices based on research, believing that this will contribute for a better future professional development. Comparing the studied settings we globally verified a favourable perspective for the adoption of an EBP existing however facilitators whose mean is highest in the hospital context. Conclusion: It has been noted the need for additional support regarding the adoption of EBP. Therefore is essential an integrated policy to streamline clinical research involving the active participation both of the clinical practice nurses and academic institutions

    Grand Rounds: Could Occupational Exposure to n-Hexane and Other Solvents Precipitate Visual Failure in Leber Hereditary Optic Neuropathy?

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    CONTEXT: Leber hereditary optic neuropathy (LHON) is a maternally inherited loss of central vision related to pathogenic mutations in the mitochondrial genome, which are a necessary but not sufficient condition to develop the disease. Investigation of precipitating environmental/occupational (and additional genetic) factors could be relevant for prevention. CASE PRESENTATION: After a 6-month period of occupational exposure to n-hexane and other organic solvents, a 27-year-old man (a moderate smoker) developed an optic neuropathy. The patient had a full ophthalmologic and neurologic investigation, including standardized cycloergometer test for serum lactic acid levels and a skeletal muscle biopsy. His exposure history was also detailed, and he underwent genetic testing for LHON mitochondrial DNA mutations. The patient suffered a sequential optic neuropathy with the hallmarks of LHON and tested positive for the homoplasmic 11778G → A/ND4 mutation. Routine laboratory monitoring revealed increased concentrations of urinary 2.5 hexandione (n-hexane metabolite) and hippuric acid (toluene metabolite) in the period immediately preceding the visual loss. DISCUSSION: In a subject carrying an LHON mutation, the strict temporal sequence of prolonged appreciable occupational exposure followed by sudden onset of visual loss must raise a suspicion of causality (with a possible further interaction with tobacco smoke). RELEVANCE: In this article, we add to the candidate occupational/environmental triggers of LHON and highlight the need for appropriate case–control (and laboratory) studies to validate the causal effect of mixed toxic exposures

    RINL, Guanine Nucleotide Exchange Factor Rab5-Subfamily, Is Involved in the EphA8-Degradation Pathway with Odin

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    The Rab family of small guanosine triphosphatases (GTPases) plays a vital role in membrane trafficking. Its active GTP-bound state is driven by guanine nucleotide-exchange factors (GEFs). Ras and Rab interactor (or Ras interaction/interference)-like (RINL), which contains a conserved VPS9 domain critical for GEF action, was recently identified as a new Rab5 subfamily GEF in vitro. However, its detailed function and interacting molecules have not yet been fully elucidated. Here we found that RINL has GEF activity for the Rab5 subfamily proteins by measuring their GTP-bound forms in cultured cells. We also found that RINL interacts with odin, a member of the ankyrin-repeat and sterile-alpha motif (SAM) domain-containing (Anks) protein family. In addition, the Eph tyrosine kinase receptor EphA8 formed a ternary complex with both RINL and odin. Interestingly, RINL expression in cultured cells reduced EphA8 levels in a manner dependent on both its GEF activity and interaction with odin. In addition, knockdown of RINL increased EphA8 level in HeLa cells. Our findings suggest that RINL, as a GEF for Rab5 subfamily, is implicated in the EphA8-degradation pathway via its interaction with odin
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