1,721,024 research outputs found

    Air pollution effects on the respiratory health of the resident adult population in Turin, Italy

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    A case-control study was employed to investigate the relationship between atmospheric pollution and emergency hospital attendance for respiratory causes among adult and elderly patients resident in Turin in the period 1997 - 1999. Based on the primary diagnosis, adult (15 - 64 years) and elderly (>64 years) patients resident in Turin and admitted for respiratory causes were defined as Cases (n1 = 4.645); adult and elderly patients admitted for causes other than respiratory diseases or heart diseases were defined as Controls (n2 = 152.954). Sulfur dioxide (SO2 in microg/m3), total suspended particulate (TSP in microg/m3) and carbon monoxide (CO in mg/m3) were taken as indicators of urban air pollution; principal confounding factors were patient sex, age and education level; season, temperature, humidity, solar radiation; day of hospital admission. Statistical analysis was performed using logistic regression models. In accordance with Odds Ratio (OR) values and relative 95% Confidence Intervals (OR_95% CI) estimated by the models, associations are expressed as percent increase in risk (Increase%)1 and relative 95% Confidence Interval (95% CI) per 10 microg/m3 in SO2 and TSP, and per 1 mg/m3 in CO exposure. After adjusting for confounding factors, there was a mean increase in emergency hospital attendance of 2.20% (95% CI 1.70 - 2.60) and 2.55% (95% CI 1.79 - 3.32) per 10 microg/m3 increase in exposure to SO2 and TSP, respectively, and a mean increase of 5.30% (95% CI 3.00 - 7.70) per 1 mg/m3 increase in exposure to CO. A significant association was separately confirmed for SO2 and TSP in adult (15 - 64 years) and elderly (>64 years) patients, but for CO only among elderly patients. A significant association was found between the increase in emergency hospital attendance for respiratory causes and exposure to sulfur dioxide, total suspended particulate and carbon monoxide in Turin during the study period. This easy to use and manage case-control study produced results in line with those reported for other Italian and European cities

    A new numerical method for processing longitudinal data: clinical applications

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    Background: Processing longitudinal data is a computational issue that arises in many applications, such as in aircraft design, medicine, optimal control and weather forecasting. Given some longitudinal data, i.e. scattered measurements, the aim consists in approximating the parameters involved in the dynamics of the considered process. For this problem, a large variety of well-known methods have already been developed. Results: Here, we propose an alternative approach to be used as effective and accurate tool for the parameters fitting and prediction of individual trajectories from sparse longitudinal data. In particular, our mixed model, that uses Radial Basis Functions (RBFs) combined with Stochastic Optimization Algorithms (SOMs), is here presented and tested on clinical data. Further, we also carry out comparisons with other methods that are widely used in this framework. Conclusions: The main advantages of the proposed method are the flexibility with respect to the datasets, meaning that it is effective also for truly irregularly distributed data, and its ability to extract reliable information on the evolution of the dynamics

    IDENTIFICATION OF THREE DISTINCT SUBGROUPS OF B-CELL CHRONIC LYMPHOCYTIC LEUKEMIA BASED UPON MUTATIONS OF BCL-6 AND IgV GENES

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    Although B cell chronic lymphocytic leukemia (B-CLL) has been traditionally viewed as a tumor of virgin B cells, this notion has been recently questioned by data suggesting that a fraction of B-CLL derives from antigen experienced B cells. In order to further clarify the histogenetic derivation of this lymphoproliferation, we have analyzed the DNA sequences of the 5' non-coding region of BCL-6 proto-oncogene in 28 cases of B-CLL. Mutations of BCL-6 proto-oncogene, a zinc finger transcription factor implicated in lymphoma development, represent a histogenetic marker of B cell transit through the germinal center (GC) and occur frequently in B cell malignancies derived from GC or post-GC B cells. For comparison, the same tumor panel was analyzed for somatic mutations of the rearranged immunoglobulin variable (IgV) genes, which are known to be acquired at the time of B cell transit through the GC. Sequence analyses of BCL-6 and IgV genes allowed the definition of three groups of B-CLL. Group I B-CLL displayed mutations of both BCL-6 and IgV genes (10/28; 36%). Group II B-CLL displayed mutated IgV genes, but a germline BCL-6 gene (5/28; 18%). Finally, group III B-CLL included the remaining cases (13/28; 46%) that were characterized by the absence of somatic mutations of both BCL-6 and IgV genes. Overall, the distribution of BCL-6 and IgV mutations in B-CLL reinforce the notion that this leukemia is histogenetically heterogeneous and that a substantial subgroup of these lymphoproliferations derives from post-germinal center B cells

    Influence of sodium hypochlorite on fracture properties and corrosion of ProTaper Rotary instruments

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    Aim: To evaluate the influence of immersion in NaOCl on resistance to cyclic fatigue fracture and corrosion of ProTaper NiTi Rotary instruments. Methodology: A total of 120 new ProTaper NiTi Rotary files (F2) were randomized and assigned to three different groups of 40 each. Group 1 was the control group; 20 mm (excluding the shaft) of group 2 instruments were immersed in 5% NaOCl at 50°C for 5 min; instruments in group 3 were completely immersed in 5% NaOCl at 50°C for 5 min. All instruments were then tested for cyclic fatigue, recording the time in seconds to fracture. Data were analysed by the Kruskall-Wallis test and post-hoc multiple comparisons (P < 0.05). Micromorphological and microchemical analyses were also completed by means of a field emission scanning electron microscopy (SEM) on those instruments in group 3 that had undergone early fracture. Results: Instruments in group 3 had a significantly lower resistance to fracture because of cyclic fatigue than those in groups 1 and 2 (P < 0.001). In some instruments in group 3, early fracture occurred after only a few seconds of fatigue testing. SEM observations revealed evident signs of corrosion of the fractured instruments. Conclusion: Group 3 had significantly reduced resistance to cyclic fatigue compared with instruments in groups 1 and 2. The phenomenon of early fracture may be attributed to galvanic corrosion induced by the presence of dissimilar metals, where one acts as the cathode of a galvanic couple, established when the instrument is immersed in NaOCl solution. The NiTi alloy may acts as the anode and thus undergoes corrosio
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