The use of diagnostic ratios, biomarkers and 3-way Kohonen neural networks to monitor the temporal evolution of oil spills.

Oil spill identification relies usually on a wealth of chromatographic data which requires advanced data treatment (chemometrics). A simple approach based on Kohonen neural networks to handle three-dimensional arrays is presented. A suite of 28 diagnostic ratios was considered to monitor six oils along four months. It was found that some traditional diagnostic ratios were not stable enough. In particular, alkylated PAHs (e.g. 1-methyldibenzothiophene, 4-methylpyrene, 27bbSTER and the TA21 and TA26 triaromatic steroids) seemed less resistant to medium-weathering than biomarkers. One (or two) ratios were found to differentiate each product: 30O, 28ab (and 25nor30ab), C3-dbt/C3-phe, 27Ts, TA26 and 29Ts characterized Ashtart, Brent, Maya, Sahara, IFO and Prestige oils, respectively.

A similarity-based QSAR model for predicting acute toxicity towards the fathead minnow (Pimephales promelas).

REACH regulation demands information about acute toxicity of chemicals towards fish and supports the use of QSAR models, provided compliance with OECD principles. Existing models present some drawbacks that may limit their regulatory application. In this study, a dataset of 908 chemicals was used to develop a QSAR model to predict the LC50 96 hours for the fathead minnow. Genetic algorithms combined with k nearest neighbour method were applied on the training set (726 chemicals) and resulted in a model based on six molecular descriptors. An automated assessment of the applicability domain (AD) was carried out by comparing the average distance of each molecule from the nearest neighbours with a fixed threshold. The model had good and balanced performance in internal and external validation (182 test molecules), at the expense of a percentage of molecules outside the AD. Principal Component Analysis showed apparent correlations between model descriptors and toxicity.

Impact of medium-distance pollution sources in a Galician suburban site (NW Iberian peninsula).

This work studies airborne quality in a geographical area that has not been investigated broadly: a suburban site nearby A Coruña (Galicia, NW Iberian Peninsula). In contrast to major Spanish cities, the site has Atlantic characteristics: rainy, scarce calm weather and infrequent prolonged sunny periods. The relationships between several gaseous pollutants (NO, NO2, NOx, CO, O3, PM10, PM2.5 and PM1) and their temporal trends (daily, monthly and seasonal) were evaluated. The aim was to unravel whether medium- and long-distance sources were impacting upon the site. Univariate studies focused on factorizing the pollutants according to a codifying factor (wind direction, hour of the day, season and month). Multivariate studies (Varimax-rotated factorial analysis) were done separately on both weekdays and weekends. The intensity of the daily maxima for NO, NO2, NOx and CO was lower during the weekends, with O3 behaving opposite. PM average values agreed with previous historical reports for a rural background station relatively close to the site and they decreased daily between 11:00 and 19:00 h, likely because of the marine breeze. With moderate wind speeds the pollutants were associated to medium-distance pollution sources, mainly the city of A Coruña and a combination of industrial pollution sources (a power plant, a solid waste incinerator and a regional airport).

Validation and extension of a similarity-based approach for prediction of acute aquatic toxicity towards Daphnia magna.

Quantitative structure-activity relationship (QSAR) models for predicting acute toxicity to Daphnia magna are often associated with poor performances, urging the need for improvement to meet REACH requirements. The aim of this study was to evaluate the accuracy, stability and reliability of a previously published QSAR model by means of further external validation and to optimize its performance by means of extension to new data as well as a consensus approach. The previously published model was validated with a large set of new molecules and then compared with ChemProp model, from which most of the validation data were taken. Results showed better performance of the proposed model in terms of accuracy and percentage of molecules outside the applicability domain. The model was re-calibrated on all the available data to confirm the efficacy of the similarity-based approach. The extended dataset was also used to develop a novel model based on the same similarity approach but using binary fingerprints to describe the chemical structures. The fingerprint-based model gave lower regression statistics, but also less unpredicted compounds. Eventually, consensus modelling was successfully used to enhance the accuracy of the predictions and to halve the percentage of molecules outside the applicability domain.

Particle size, chemical composition, seasons of the year and urban, rural or remote site origins as determinants of biological effects of particulate matter on pulmonary cells.

Particulate matter (PM), a complex mix of chemical compounds, results to be associated with various health effects. However there is still lack of information on the impact of its different components. PM2.5 and PM1 samples, collected during the different seasons at an urban, rural and remote site, were chemically characterized and the biological effects induced on A549 cells were assessed. A Partial Least Square Discriminant Analysis has been performed to relate PM chemical composition to the toxic effects observed. Results show that PM-induced biological effects changed with the seasons and sites, and such variations may be explained by chemical constituents of PM, derived both from primary and secondary sources. The first-time here reported biological responses induced by PM from a remote site at high altitude were associated with the high concentrations of metals and secondary species typical of the free tropospheric aerosol, influenced by long range transports and aging.

Chemometric analysis of gas chromatography with flame ionisation detection chromatograms: a novel method for classification of petroleum products.

Most oil characterisation procedures are time consuming, labour intensive and utilise only part of the acquired chemical information. Oil spill fingerprinting with multivariate data processing represents a fast and objective evaluation procedure, where the entire chromatographic profile is used. Methods for oil classification should be robust towards changes imposed on the spill fingerprint by short-term weathering, i.e. dissolution and evaporation processes in the hours following a spill. We propose a methodology for the classification of petroleum products. The method consists of: chemical analysis; data clean-up by baseline removal, retention time alignment and normalisation; recognition of oil type by classification followed by initial source characterisation. A classification model based on principal components and quadratic discrimination robust towards the effect of short-term weathering was established. The method was tested successfully on real spill and source samples.

Monitoring of alcoholic fermentation using near infrared and mid infrared spectroscopies combined with electronic nose and electronic tongue.

Effective fermentation monitoring is a growing need due to the rapid pace of change in the wine industry, which calls for fast methods providing real time information in order to assure the quality of the final product. The objective of this work is to investigate the potential of non-destructive techniques associated with chemometric data analysis, to monitor time-related changes that occur during red wine fermentation. Eight micro-fermentation trials conducted in the Valtellina region (Northern Italy) during the 2009 vintage, were monitored by a FT-NIR and a FT-IR spectrometer and by an electronic nose and tongue. The spectroscopic technique was used to investigate molecular changes, while electronic nose and electronic tongue evaluated the evolution of the aroma and taste profile during the must-wine fermentation. Must-wine samples were also analysed by traditional chemical methods in order to determine sugars (glucose and fructose) consumption and alcohol (ethanol and glycerol) production. Principal Component Analysis was applied to spectral, electronic nose and electronic tongue data, as an exploratory tool, to uncover molecular, aroma and taste modifications during the fermentation process. Furthermore, the chemical data and the PC1 scores from spectral, electronic nose and electronic tongue data were modelled as a function of time to identify critical points during fermentation. The results showed that NIR and MIR spectroscopies are useful to investigate molecular changes involved in wine fermentation while electronic nose and electronic tongue can be applied to detect the evolution of taste and aroma profile. Moreover, as demonstrated through the modeling of NIR, MIR, electronic nose and electronic tongue data, these non destructive methods are suitable for the monitoring of must-wine fermentation giving crucial information about the quality of the final product in agreement with chemical parameters. Although in this study the measurements were carried out in off-line mode, in future these non destructive techniques could be valid and simple tools, able to provide in-time information about the fermentation process and to assure the quality of wine.

Comparing roadsoils pollution patterns extracted by MOLMAP and classical three-way decomposition methods.

A recent approach based on self-organizing maps (SOMs) to extract patterns from three-way data, named MOLMAP, was applied in a four-seasons study on soil pollution and its results compared with three different conventional approaches: Parallel factor analysis (PARAFAC), matrix augmented principal components analysis (MA-PCA) and Procrustes rotation. Each sampling season comprised 92 roadsoil samples and 12 analytical variables (Cd, Co, Cu, Cr, Fe, Mn, Ni, Pb, Zn, loss on ignition, pH and humidity). It was found that all techniques yielded highly similar results as the samples became organized in two major groups, each with a differentiated pollution pattern. This confirmed MOLMAP as a reliable option to handle environmental three-way datasets and to extract accurate pollution patterns.

Self organizing maps for analysis of polycyclic aromatic hydrocarbons 3-way data from spilled oils.

In this paper, the application of a new method based on self-organizing maps (SOM; termed MOLMAP, molecular map of atom-level properties) to handle 3-way data generated in a monitoring environmental study is presented. The study comprised 50 polycyclic aromatic hydrocarbons (PAHs) analyzed in samples derived from the weathering of six oil products (four crude oils and two fuel oils) spilled under controlled conditions for about 4 months. MOLMAP yielded useful information on each mode of the data cube: weathering samples, spilled oil products, and PAHs. Thus, the different behaviors of the six oils were ascertained, along with their particular evolution on time, and their weathering patterns were studied in terms of the original PAHs. Thus, the two heaviest products (two fuel oils) were characterized by two neurons whose more relevant weights were associated to heavy PAHs, as C(1)-fluoranthene, C(2)-fluoranthene, benzo(ghi)perylene, and dibenz(ah)anthracene. The six spilled products were projected on different regions on both the MOLMAP-SOM and a subsequent principal components analysis (PCA) scatter plot, developed using the so-called MOLMAP-scores. Besides, it was possible to further differentiate between unweathered, or slightly weathered, samples and the most weathered ones. The more relevant PAHs characterizing those samples were assessed studying the weights of the neurons in which the samples got projected.

Canonical Measure of Correlation (CMC) and Canonical Measure of Distance (CMD) between sets of data. Part 1. Theory and simple chemometric applications.

So far, similarity/diversity of objects has been widely studied in different research fields and a number of distance measures to estimate diversity between objects have been proposed. However, not much interest has been addressed to analysis of how diverse are configurations of objects in two different multivariate spaces. Since computerisation and automation nowadays lead to a large availability of information, it is apparent that a system could be described in different ways and, consequently, methods for comparison of the different viewpoints are required. These methods, for instance, may be usefully applied to Quantitative Structure-Activity Relationship (QSAR) studies. In this field, several thousands of molecular descriptors have been proposed in the literature and different selections of descriptors define different chemical spaces that need to be compared. Moreover, variable selection techniques such as Genetic Algorithms, Simulated Annealing, and Tabu Search are widely used to process available information in order to select optimal QSAR models. When more than one optimal model results, the problem arising is how to compare these models to find out whether they are really diverse or based on descriptors explaining almost the same information. In this paper, novel indices are proposed to measure similarity/diversity between pairs of data sets by the aid of the variable cross-correlation matrix.

Canonical Measure of Correlation (CMC) and Canonical Measure of Distance (CMD) between sets of data Part 2. Variable reduction.

This paper proposes a new method for determining the subset of variables that reproduce as well as possible the main structural features of the complete data set. This method can be useful for pre-treatment of large data sets since it allows discarding variables that contain redundant information. Reducing the number of variables often allows one to better investigate data structure and obtain more stable results from multivariate modelling methods. The novel method is based on the recently proposed canonical measure of correlation (CMC index) between two sets of variables [R. Todeschini, V. Consonni, A. Manganaro, D. Ballabio, A. Mauri, Canonical Measure of Correlation (CMC) and Canonical Measure of Distance (CMD) between sets of data. Part 1. Theory and simple chemometric applications, Anal. Chim. Acta submitted for publication (2009)]. Following a stepwise procedure (backward elimination), each variable in turn is compared to all the other variables and the most correlated is definitively discarded. Finally, a key subset of variables being as orthogonal as possible are selected. The performance was evaluated on both simulated and real data sets. The effectiveness of the novel method is discussed by comparison with results of other well known methods for variable reduction, such as Jolliffe techniques, McCabe criteria, Krzanowski approach and its modification based on genetic algorithms, loadings of the first principal component, Key Set Factor Analysis (KSFA), Variable Inflation Factor (VIF), pairwise correlation approach, and K correlation analysis (KIF). The obtained results are consistent with those of the other considered methods; moreover, the advantage of the proposed CMC method is that calculation is very quick and can be easily implemented in any software application.

Endoscopic thoracic sympathectomy by clamping in the treatment of social phobia: the Monza experience.

AIM: Facial blushing represents the peculiar symptom in social phobia and is defined as the ''hallmark of embarrassment''. At present, endoscopic thoracic sympathectomy (ETS) is the technique only able to guarantee long-term results in the treatment of sympathetic disorders. The aim of our study was to evaluate results, complications and the true value of 52 ETSs by two-port approach with the use of endoclips in patients with isolated facial blushing or in association with hyperhidrosis. METHODS: A retrospective review of 52 subjects who underwent standard ETS by clamping between September 2002 and April 2005 was carried out. This surgical practice was performed in 26 cases (50%) for isolated facial blushing only and in other 26 cases (50%) for facial blushing associated to hyperhidrosis with changeable localizations. Under endoscopic guidance we operated an endoscopic sympathetic block (ESB) with interruption of the inter-ganglion trunk at the level of T2-T3 in 51 patients (98.07%). In 1 patient (1.92%) we performed a sympathetic block with the complete exclusion of T3 thoracic ganglion. RESULTS: There were no intra and postoperative deaths. The effect rate was excellent in all patients with early complications in one patient (1.92%) only. CONCLUSIONS: ETS by clamping is safe and effective. Patients referred an high satisfaction in terms of complications and quality of life; specific early and late diseases are negligible.

Characterization of DNA primary sequences by a new similarity/diversity measure based on the partial ordering.

The similarity/diversity measures play a fundamental role in library searching, virtual screening, and quantitative structure-activity relationship/quantitative structure-property relationship modeling as well as in genomics and proteomics. In this paper, a new similarity/diversity measure is proposed as a new approach for the analysis of sequential data, where useful information can be also obtained by the ordering relationships between the sequence elements. This methodology can be applied for evaluating molecular similarity/diversity, using sets of sequential descriptors, and for evaluating the similarity between spectra, sensor arrays, and other sequential data such as DNA and protein sequences. The new proposed distance (weighted standardized Hasse distance) is evaluated between pairs of Hasse matrices derived from the classical partial-ordering rules. It can be naturally standardized, thus allowing the interpretation of these distances as absolute values (e.g., percentage) and deriving simple similarity and correlation indices. A simple example is taken to highlight the behavior of the new similarity/diversity measure on DNA sequences taken from the first exons of the beta-globins for eight different species. Sensitivity analysis has been also performed, showing the high capability of this measure to take into account small modifications of the DNA sequences. Finally, a comparison with results obtained from the literature is given, together with a comparison with matrix invariants derived from the Hasse matrix.

[Pleural empyema: considerations about experience of the Thoracic Surgery Division in Monza and proposal of therapeutic protocol]. / Gli empiemi pleurici: considerazioni sull'esperienza della Divisione di Chirurgia Toracica di Monza e proposta di un protocollo terapeutico.

AIM: Optima l treatment of thoracic empyema depends on its phase of development. Thin, free-flowing exudative effusions can be adequately managed by thoracenthesis or simple closed tube thoracostomy and antibiotics. At the other end of the spectrum are well-organized chronic empyemas which are best treated with thoracothomy and decortication. In-between this two extremes are fibrino-purulent empyemas for which much controversies exist among pneumologists and thoracic surgeons over the most effective treatment. The authors present their experience about treatment of pleural empyema. METHODS: This retrospective study reviews the Thoracic Surgery Department of Monza's S. Gerardo Hospital experience between 1982-2004 in the treatment of thoracic empyema and tries to formulate our own guidelines for the management of the fibrino-purulent forms. RESULTS: In our experience we used a personal technique of thoracic drainage consisting in continuous wash-out of pleural cavity associated with intrapleural fibrinolytic if is it necessary. Since 1994 we have used the continuous positive alveolar pressure to mend lungs expansion and improve the CONCLUSIONS: Recent reports in the medical and surgical literature have suggested that empyemas can be managed effectively with less aggressive treatment than has been advocated in the past. In spite of the recent development of mini-invasive surgical techniques for the treatment of fibrino-purulent empyemas we believe that first approach should be always conservative. Intrapleural fibrinolytics seem to get improve the efficacy of closed tube thoracostomy.

[Thoracic sympathetic block by clamping in the treatment of primary hyperhidrosis: indications and results in 281 patients]. / Interruzione del simpatico toracico mediante neurocompressione nel trattamento dell'iperidrosi primitiva. Indicazioni e risultati ottenuti in 281 pazienti.

AIM: Hyperhidrosis is a disabling troublesome characterized by excessive perspiration that produces a significant social and professional deficit for patients. It main involves the palmar sides of hands and feet, axillae, face and, with a lesser incidence, trunk and scalp. Thoracoscopic sympathectomy represents the best approach for this disorder. The aim of our prospective study is to assess the outcome, the safety and efficacy after thoracoscopic sympathetic block by clipping in the treatment of primary hyperhidrosis. METHODS: Between september 2002 and april 2005, 281 patients (117 female and 164 male, with a mean age of 28 years) underwent Endoscopic Thoracic Sympathectomy (ETS) to treat hyperhidrosis with palmar, axillar, facial and widespread localization. RESULTS: There were no deaths or major intra-operative problems. There was no conversion to open surgery. During intermediate and long-term follow up we obtained excellent results and few complications. In 3 patients (1.06%) we noted a major complication (Horner's Syndrome), but one patient only had the surgical operation reversed; compensatory sweating occurred in 61 individuals (21.7%). Gustatory sweating occurred in no patient. CONCLUSIONS: The clipping of the thoracic sympathetic chain is a reversible surgical technique considered safe and effective. Despite of an incidence of complications and/or compensatory sweating and according to our operatory results, we conclude that the sympathetic block by clamping is the elective treatment for hyperhidrosis.

Biological and clinical results of a neuroimmunotherapy with interleukin-2 and the pineal hormone melatonin as a first line treatment in advanced non-small cell lung cancer.

The metastatic non-small cell lung cancer (NSCLC) still remains an untreatable disease, and the role played by chemotherapy has yet to be defined. The new immunotherapeutic strategies, such as interferon and IL-2, seem to be also less effective, since they generally determine only a stabilisation of disease. On the basis of previous experimental results suggesting a synergistic action between IL-2 and the pineal neurohormone melatonin (MLT), a study was started to evaluate the clinical efficacy and toxicity of a neuroimmunotherapeutic combination consisting of IL-2 plus MLT as a first line therapy in metastatic NSCLC. The study included 20 patients (adenocarcinoma: 10; epidermoid cell carcinoma: 7; large cell carcinoma: 3). MLT was given orally at a dose of 10 mg day-1 at 8.00 pm every day, starting 7 days before the onset of IL-2 administration. IL-2 was given subcutaneously at a dose of 3 x 10(6) IU m-2 every 12 h for 5 days/week for 4 weeks, corresponding to one cycle of immunotherapy. In responder patients or in those with stable disease, a second cycle was given after a rest-period of 21 days. A partial response was achieved in 4/20 (20%) patients. Ten other patients had a stable disease (50%), whereas the last six patients progressed. Toxicity was low in all cases. This study shows that the neuroimmunotherapeutic therapy with IL-2 and the pineal hormone MLT may represent a new effective and well tolerated treatment in metastatic NSCLC, with results comparable to those obtained with chemotherapy, but with an apparent lower biological toxicity.

Postoperative increase in soluble interleukin-2 receptor serum levels as predictor for early recurrence in non-small cell lung carcinoma.

It is known that interleukin-2 (IL-2) plays an important role in the activation of host antitumor immune response. In addition to IL-2 cell surface receptor, a soluble form of IL-2 receptor (SIL-2R) may be released in the blood and potentially be involved in the regulation of IL-2 availability. High SIL-2R levels have been found in patients with lung cancer. The current study evaluated the influence of changes in SIL-2R serum levels during the perioperative period on early relapse rate in patients with operable non-small cell lung cancer. The study included 60 patients (epidermoid carcinoma, 33; adenocarcinoma, 27). Serum levels of SIL-2R were measured with an enzyme immunoassay before surgery and 7 and 30 days after surgery. A surgery-induced increase in SIL-2R levels was seen 7 days after surgery in 38 of 60 patients. On the 30th day after surgery, SIL-2R values were lower than the preoperative values in 32 patients (Group A) or still greater in the other 28 patients (Group B). After a median follow-up of 10 months, relapse occurred in 19 of 60 patients. The relapse rate was significantly higher in Group B than in Group A patients (16 of 28 versus 3 of 32, respectively; P less than 0.001). This difference also was significant in relation to histotype and node status. This study shows that the persistence of increased SIL-2R levels in the postoperative period is associated with a higher early relapse rate in patients with operable non-small cell lung cancer. The impact of SIL-2R levels on relapse suggests that host immune defenses may influence the clinical course of patients with lung cancer. Therefore, the evaluation of SIL-2R in the perioperative period may represent a new prognostic biologic factor in operable non-small cell lung cancer.