Fourier transform near-infrared and mid-infrared spectroscopy as efficient tools for rapid screening of deoxynivalenol contamination in wheat bran.

BACKGROUND: Deoxynivalenol (DON) is the most common Fusarium mycotoxin occurring in wheat and wheat-derived products, with several adverse and toxic effects in animals and humans. Although bran fractions produced by milling wheat have numerous health benefits, cereal bran is the part of the grain with the highest concentration of DON, thus representing a risk for consumers. Increased efforts have been made to develop analytical methods suitable for rapid DON screening. RESULTS: The applicability of Fourier transform near-infrared (FTNIR), or mid-infrared (FTMIR) spectroscopy, and their combination for rapid analysis of DON in wheat bran, was investigated for the classification of samples into compliant and non-compliant groups regarding the EU legal limit of 750 µg kg-1 . Partial least squares-discriminant analysis (PLS-DA) and principal component-linear discriminant analysis (PC-LDA) were employed as classification techniques using a cutoff value of 400 µg kg-1 DON to distinguish the two classes. Depending on the classification model, overall discrimination rates were from 87% to 91% for FTNIR and from 86% to 87% for the FTMIR spectral range. The FTNIR spectroscopy gave the highest overall classification rate of wheat bran samples, with no false compliant samples and 18% false noncompliant samples when the PC-LDA classification model was applied. The combination of the two spectral ranges did not provide a substantial improvement in classification results in comparison with FTNIR. CONCLUSIONS: Fourier transform near-infrared spectroscopy in combination with classification models was an efficient tool to screen many DON-contaminated wheat bran samples and assess their compliance with EU regulations. © 2018 Society of Chemical Industry.

Encapsulation of Curcumin-Loaded Liposomes for Colonic Drug Delivery in a pH-Responsive Polymer Cluster Using a pH-Driven and Organic Solvent-Free Process.

The present study aimed to develop and optimize liposome formulation for the colonic delivery of biologically active compounds. A strategy to facilitate such targeting is to formulate liposomes with a polymer coating sensitive to the pH shifts in the gastrointestinal tract. To this end, liposomes encapsulating curcumin-chosen as the biologically active compound model-and coated with the pH-responsive polymer Eudragit S100 were prepared and characterized. Curcumin was encapsulated into small unilamellar vesicles (SUVs) by the micelle-to-vesicle transition method (MVT) in a simple and organic solvent-free way. Curcumin-loaded liposomes were coated with Eudragit S100 by a fast and easily scalable pH-driven method. The prepared liposomes were evaluated for size, surface morphology, entrapment efficiency, stability, in vitro drug release, and curcumin antioxidant activity. In particular, curcumin-loaded liposomes displayed size lower than 100 nm, encapsulation efficiency of 98%, high stability at both 4 °C and 25 °C, high in vitro antioxidant activity, and a cumulative release that was completed within 200 min. A good Eudragit S100 coating which did not alter the properties of the curcumin-loaded liposomes was obtained. The present work therefore provides a fast and solvent-free method to prepare pH-responsive polymer-coated liposomes for the colonic delivery of biologically active compounds.

Rapid prediction of deoxynivalenol contamination in wheat bran by MOS-based electronic nose and characterization of the relevant pattern of volatile compounds.

BACKGROUND: Deoxynivalenol (DON) is a mycotoxin, mainly produced by Fusarium sp., most frequently occurring in cereals and cereal-based products. Wheat bran refers to the outer layers of the kernel, which has a high risk of damage due to chemical hazards, including mycotoxins. Rapid methods for DON detection in wheat bran are required. RESULTS: A rapid screening method using an electronic nose (e-nose), based on metal oxide semiconductor sensors, has been developed to distinguish wheat bran samples with different levels of DON contamination. A total of 470 naturally contaminated wheat bran samples were analyzed by e-nose analysis. Wheat bran samples were divided in two contamination classes: class A ([DON] ≤ 400 µg kg-1 , 225 samples) and class B ([DON] > 400 µg kg-1 , 245 samples). Discriminant function analysis (DFA) classified wheat bran samples with good mean recognizability in terms of both calibration (92%) and validation (89%). A pattern of 17 volatile compounds of wheat bran samples that were associated (positively or negatively) with DON content was also characterized by HS-SPME/GC-MS. CONCLUSIONS: These results indicate that the e-nose method could be a useful tool for high-throughput screening of DON-contaminated wheat bran samples for their classification as acceptable / rejectable at contamination levels close to the EU maximum limit for DON, reducing the number of samples to be analyzed with a confirmatory method. © 2018 Society of Chemical Industry.

Isotope ratio mass spectrometry in combination with chemometrics for characterization of geographical origin and agronomic practices of table grape.

BACKGROUND: Although table grape is one of the most cultivated and consumed fruits worldwide, no study has been reported on its geographical origin or agronomic practice based on stable isotope ratios. This study aimed to evaluate the usefulness of isotopic ratios (i.e. 2 H/1 H, 13 C/12 C, 15 N/14 N and 18 O/16 O) as possible markers to discriminate the agronomic practice (conventional versus organic farming) and provenance of table grape. RESULTS: In order to quantitatively evaluate which of the isotopic variables were more discriminating, a t test was carried out, in light of which only δ13 C and δ18 O provided statistically significant differences (P ≤ 0.05) for the discrimination of geographical origin and farming method. Principal component analysis (PCA) showed no good separation of samples differing in geographical area and agronomic practice; thus, for classification purposes, supervised approaches were carried out. In particular, general discriminant analysis (GDA) was used, resulting in prediction abilities of 75.0 and 92.2% for the discrimination of farming method and origin respectively. CONCLUSION: The present findings suggest that stable isotopes (i.e. δ18 O, δ2 H and δ13 C) combined with chemometrics can be successfully applied to discriminate the provenance of table grape. However, the use of bulk nitrogen isotopes was not effective for farming method discrimination. © 2016 Society of Chemical Industry.

Effects of Curative Colorectal Cancer Surgery on Exhaled Volatile Organic Compounds and Potential Implications in Clinical Follow-up.

OBJECTIVE: The aim of this study was to determine whether the volatile organic compounds (VOCs) pattern in colorectal cancer (CRC) patients is modified by curative surgery for a potential application in the oncologic follow-up. BACKGROUND: CRC has been proved to induce metabolic derangements detectable by high through-output techniques in exhaled breath showing a specific pattern of VOCs. METHODS: Forty-eight CRC patients and 55 healthy controls (HC) entered the study. Thirty-two patients (M/F: 1.4; mean age 63 years) attended the oncologic follow-up (mean 24 months) and were found disease-free. Breath samples were collected under similar environmental conditions into a Tedlar bags and processed offline by thermal-desorption gas chromatography-mass spectrometry (TD-GC-MS). VOCs were selected by U test to build a Probabilistic Neural Network (PNN) model to set-up a training phase, which was cross-validated using the leave-one out method. RESULTS: A total of 11 VOCs were finally selected for their excellent discriminant performance in identifying disease-free patients in follow-up from CRC patients before surgery, (sensitivity 100%, specificity 97.92%, accuracy 98.75%, and AUC: 1). The same VOCs pattern discriminated follow-up patients from HC, with a sensitivity of 100%, specificity of 90.91%, accuracy of 94.25%, and AUC 0.959. CONCLUSIONS: Exhaled VOCs pattern from CRC patients is modified by cancer removal confirming the tight relationship between tumor metabolism and exhaled VOCs. PNN analysis provides a high discriminatory tool to identify patients disease-free after curative surgery suggesting potential implications in CRC screening and secondary prevention.

Performance Assessment in Fingerprinting and Multi Component Quantitative NMR Analyses.

An interlaboratory comparison (ILC) was organized with the aim to set up quality control indicators suitable for multicomponent quantitative analysis by nuclear magnetic resonance (NMR) spectroscopy. A total of 36 NMR data sets (corresponding to 1260 NMR spectra) were produced by 30 participants using 34 NMR spectrometers. The calibration line method was chosen for the quantification of a five-component model mixture. Results show that quantitative NMR is a robust quantification tool and that 26 out of 36 data sets resulted in statistically equivalent calibration lines for all considered NMR signals. The performance of each laboratory was assessed by means of a new performance index (named Qp-score) which is related to the difference between the experimental and the consensus values of the slope of the calibration lines. Laboratories endowed with a Qp-score falling within the suitable acceptability range are qualified to produce NMR spectra that can be considered statistically equivalent in terms of relative intensities of the signals. In addition, the specific response of nuclei to the experimental excitation/relaxation conditions was addressed by means of the parameter named NR. NR is related to the difference between the theoretical and the consensus slopes of the calibration lines and is specific for each signal produced by a well-defined set of acquisition parameters.

Rose Bengal-photosensitized oxidation of 4-thiothymidine in aqueous medium: evidence for the reaction of the nucleoside with singlet state oxygen.

The photoreactivity of 4-thiothymidine (S(4)TdR) under visible light in the presence of Rose Bengal (RB), acting as a photosensitizer, was investigated in aqueous solutions at pH 7 and 12, using UV-vis, FTIR-ATR and (1)H-NMR spectroscopic techniques, time resolved absorption spectroscopy and electrospray ionization mass spectrometry (ESI-MS). Evidence for the generation of thymidine (TdR) as the main product, after one hour of irradiation, was obtained from UV-Vis data, that suggested 4-thiothymidine photodegradation to be faster at basic pH, and confirmed by FTIR-ATR and (1)H-NMR data. Clues for the presence of a further product, likely corresponding to a dimeric form of S(4)TdR, were obtained from the latter techniques. Besides indicating the presence of thymidine, the ESI-MS and MS/MS spectra of the reaction mixtures enabled the identification of the additional product as a S-S bridged covalent dimer of 4-thiothymidine. The concentration of the dimeric species could be estimated with the aid of (1)H-NMR data and was found to be lower than that of thymidine in pH 7 reaction mixtures and almost negligible in the pH 12 ones. From a mechanistic point of view, time-resolved absorption spectroscopy measurements provided direct evidence that the formation of the two products cannot be ascribed to a photoinduced electron transfer involving S(4)TdR and the excited triplet state of RB. Rather, their generation can be interpreted as the result of a bimolecular reaction occurring between singlet state oxygen ((1)O2), photogenerated by RB, and S(4)TdR, as demonstrated by the direct detection of (1)O2 through IR luminescence spectroscopy. More specifically, a sequential reaction pathway, consisting in the generation of an electrophilic hydroxylated form of S(4)TdR and its subsequent, rapid reaction with S(4)TdR, was hypothesized to explain the presence of the S-S bridged covalent dimer of 4-thiothymidine in the reaction mixtures. The described processes make S(4)TdR an interesting candidate in the role of molecular probe for the detection of (1)O2 under different pH conditions.

Photosystem II based multilayers obtained by electrostatic layer-by-layer assembly on quartz substrates.

Photosystem II (PSII) proteins from spinach leaves were immobilized onto quartz substrates according to the Layer-by-Layer (LbL) procedure, alternating protein to polyethylenimine (PEI) layers by exploiting electrostatic interactions. The effects of several factors, such as storage conditions, ageing of the PSII-modified substrates, as well as PSII concentration in buffer, on the quality of the prepared multilayers, were investigated by UV-vis Absorption Spectroscopy and Atomic Force Microscopy (AFM). A number of 13 layers was found to be optimal to guarantee intense PSII optical signals with homogeneous morphological distributions of proteins. The multilayers resulted stable if stored in contact with air at 4 °C, as observed by UV-vis Absorption spectra recorded after 48 h. The best results in terms of AFM images and electron transfer efficiency (measured by Hill Reaction assays) were gained by using 5.6 × 10(-7) M chlorophyll concentration, obtaining multilayers with the most ordered protein distributions and the highest electron transfer efficiency, i.e. 85% of an iso-absorbing PSII suspension. The results highlight the possibility to successfully immobilize PSII proteins, without considerable loss of bioactivity, thanks to the mild nature of the electrostatic LbL technique, opening up possibilities of applications in the bioelectrochemical energy conversion and biosensoristic fields.

A holistic evaluation of patients with chronic Hepatitis D virus (HDV) infection enrolled in the Italian PITER-B and delta cohort.

BACKGROUND AND AIMS: We aimed to characterize the epidemiologic and comorbidities profiles of patients with chronic Hepatitis D (CHD) followed in clinical practice in Italy and explored their interferon (IFN) eligibility. METHODS: This was a cross-sectional study of the PITER cohort consisting of consecutive HBsAg-positive patients from 59 centers over the period 2019-2023. Multivariable analysis was performed by logistic regression model. RESULTS: Of 5492 HBsAg-positive enrolled patients, 4152 (75.6%) were screened for HDV, 422 (10.2%) were anti-HDV positive. Compared with HBsAg mono-infected, anti-HDV positive patients were more often younger, non-Italians, with a history of drug use, had elevated alanine transaminase (ALT), cirrhosis, or hepatocellular carcinoma (HCC). Compared with Italians, anti-HDV positive non-Italians were younger (42.2% age ≤ 40 years vs. 2.1%; P < 0.001), more often females (males 43.0% vs. 68.6%; P < 0.001) with less frequent cirrhosis and HCC. HDV-RNA was detected in 63.2% of anti-HDV-positive patients, who were more likely to have elevated ALT, cirrhosis, and HCC. Extrahepatic comorbidities were present in 47.4% of anti-HDV positive patients and could affect the eligibility of IFN-containing therapies in at least 53.0% of patients in care. CONCLUSIONS: CHD affects young, foreign-born patients and older Italians, of whom two-thirds had cirrhosis or HCC. Comorbidities were frequent in both Italians and non-Italians and impacted eligibility for IFN.

Studying ancient crop provenance: implications from δ(13)C and δ(15)N values of charred barley in a Middle Bronze Age silo at Ebla(NW Syria).

The discovery of a storeroom full of barley and other cereals (L.9512) in the proto-historic site of Ebla has provided a unique opportunity to study the centralized storage system of the early city-state from a different perspective. Epigraphic evidence available within the site reveals a complex system of taxation which included gathering grain tributes from satellite sites and redistributing semi-finished products such as flour. In this paper, we intend to explore the possibilities of a combined approach to studying the storage system, based on estimated barley grain volumes and δ(13)C-δ(15)N analyses. This approach is used to distinguish between grain from different harvesting sites and to identify any grain cultivated using special agricultural practices (e.g. manuring or irrigation). The basic assumption for this kind of analysis is that the growth-site conditions, natural or anthropogenic, of harvested cereals are reflected in their grain size and δ(13)C-δ(15)N values. Since the remains found in the storeroom were charred, the first task was to evaluate the effect of carbonization on the δ(13)C-δ(15)N and the size of the grains. Thus, the effect of charring was tested on modern samples of Syrian barley landraces. Once it had been ascertained that fresh grains reduced to charred remains retain their original biometric and isotopic traits, the ancient material was examined. Thirteen groups were identified, each characterized by a specific average volume and specific carbon and nitrogen values. The analysis revealed that what had first appeared to be a homogeneous concentration of grain was in fact an assemblage of barley harvested from different sites.

Paving the Way to Food Grade Analytical Chemistry: Use of a Natural Deep Eutectic Solvent to Determine Total Hydroxytyrosol and Tyrosol in Extra Virgin Olive Oils.

Extra virgin olive oil (EVOO) is well known for containing relevant amounts of healthy phenolic compounds. The European Food Safety Authority (EFSA) allowed a health claim for labelling olive oils containing a minimum amount of hydroxytyrosol (OHTyr) and its derivatives, including tyrosol (Tyr). Therefore, harmonized and standardized analytical protocols are required in support of an effective application of the health claim. Acid hydrolysis performed after extraction and before chromatographic analysis has been shown to be a feasible approach. Nevertheless, other fast, green, and easy methods could be useful for on-site screening and monitoring applications. In the present research, a natural deep eutectic solvent (NADES) composed of lactic acid and glucose was used to perform a liquid/liquid extraction on EVOO samples, followed by UV-spectrophotometric analysis. The spectral features of the extracts were related with the content of total OHTyr and Tyr, determined by the acid hydrolysis method. The second derivative of spectra allowed focusing on three single wavelengths (i.e., 299 nm, 290 nm, and 282 nm) significantly related with total OHTyr, total Tyr, and their sum, respectively. In particular, the sum of OHTyr and Tyr could be determined with a root mean square error of prediction of 29.5 mg kg-1, while the limits of quantitation and detection were respectively 11.8 and 4.9 mg kg-1. The proposed method, therefore, represents an easy screening tool, with the use of a green, food-derived solvent, and could be considered as an attempt to pave the way for food grade analytical chemistry.

Quality evaluation of table grapes during storage by using 1H NMR, LC-HRMS, MS-eNose and multivariate statistical analysis.

Three non-targeted methods, i.e. 1H NMR, LC-HRMS, and HS-SPME/MS-eNose, combined with chemometrics, were used to classify two table grape cultivars (Italia and Victoria) based on five quality levels (5, 4, 3, 2, 1). Grapes at marketable quality levels (5, 4, 3) were also discriminated from non-marketable quality levels (2 and 1). PCA-LDA and PLS-DA were applied, and results showed that, the MS-eNose provided the best results. Specifically, with the Italia table grapes, mean prediction abilities ranging from 87% to 88% and from 98% to 99% were obtained for discrimination amongst the five quality levels and of marketability/non-marketability, respectively. For the cultivar Victoria, mean predictive abilities higher than 99% were achieved for both classifications. Good models were also obtained for both cultivars using NMR and HRMS data, but only for classification by marketability. Satisfying models were further validated by MCCV. Finally, the compounds that contributed the most to the discriminations were identified.

A community-built calibration system: The case study of quantification of metabolites in grape juice by qNMR spectroscopy.

Nuclear Magnetic Resonance (NMR) is an analytical technique extensively used in almost every chemical laboratory for structural identification. This technique provides statistically equivalent signals in spite of using spectrometer with different hardware features and is successfully used for the traceability and quantification of analytes in food samples. Nevertheless, to date only a few internationally agreed guidelines have been reported on the use of NMR for quantitative analysis. The main goal of the present study is to provide a methodological pipeline to assess the reproducibility of NMR data produced for a given matrix by spectrometers from different manufacturers, with different magnetic field strengths, age and hardware configurations. The results have been analyzed through a sequence of chemometric tests to generate a community-built calibration system which was used to verify the performance of the spectrometers and the reproducibility of the predicted sample concentrations.

Fluorescence polarization immunoassay for rapid screening of ochratoxin A in red wine.

A fluorescence polarization (FP) immunoassay, based on a monoclonal antibody and an ochratoxin A (OTA)-fluorescein tracer, has been developed for rapid screening of OTA in red wine. Wine samples were diluted with methanol and passed through aminopropyl solid-phase extraction columns prior to the FP assay. Average recoveries from samples spiked with OTA at levels of 2.0 and 5.0 ng/mL were 79% with RDS of 11% (n = 6). The limit of detection of the FP immunoassay was 0.7 ng/mL OTA, and the whole analysis was performed in less than 10 min. The assay was tested on 154 red wine samples (naturally contaminated or spiked at level ranging from 0.1 to 5.0 ng/mL) and compared with an high-performance liquid chromatography/immunoaffinity column clean-up method, showing a good correlation (r = 0.9222). Their compliance with the European regulation (2.0 ng/mL OTA maximum permitted level) was correctly assessed for 70% of the analyzed samples of red wine, whereas confirmatory analyses were required for the remaining ones with OTA levels close to the regulatory limit. No false-negative or positive results were observed using the FP immunoassay. The proposed FP assay is a useful screening method for OTA in red wines, when high throughput is required, that could also be used for white and rosé wines, which are known to contain less interfering compounds such as polyphenols.

Aflatoxin B1-Adsorbing Capability of Pleurotus eryngii Mycelium: Efficiency and Modeling of the Process.

Aflatoxin B1 (AfB1) is a carcinogenic mycotoxin that contaminates food and feed worldwide. We determined the AfB1-adsorption capability of non-viable Pleurotus eryngii mycelium, an edible fungus, as a potential means for removal of AfB1 from contaminated solutions. Lyophilized mycelium was produced and made enzymatically inert by sterilization at high temperatures. The material thus obtained was characterized by scanning electron microscopy with regard to the morpho-structural properties of the mycotoxin-adsorbing surfaces. The active surfaces appeared rough and sponge-like. The AfB1-mycelium system reached equilibrium at 37°C, 30 min, and pH 5-7, conditions that are compatible with the gastro-intestinal system of animals. The system remained stable for 48 h at room temperature, at pH 3, pH 7, and pH 7.4. A thermodynamic study of the process showed that this is a spontaneous and physical adsorption process, with a maximum of 85 ± 13% of removal efficiency of AfB1 by P. eryngii mycelium. These results suggest that biosorbent materials obtained from the mycelium of the mushroom P. eryngii could be used as a low-cost and effective feed additive for AfB1 detoxification.

Discrimination of geographical origin of oranges (Citrus sinensis L. Osbeck) by mass spectrometry-based electronic nose and characterization of volatile compounds.

An untargeted method using headspace solid-phase microextraction coupled to electronic nose based on mass spectrometry (HS-SPME/MS-eNose) in combination with chemometrics was developed for the discrimination of oranges of three geographical origins (Italy, South Africa and Spain). Three multivariate statistical models, i.e. PCA/LDA, SELECT/LDA and PLS-DA, were built and relevant performances were compared. Among the tested models, SELECT/LDA provided the highest prediction abilities in cross-validation and external validation with mean values of 97.8% and 95.7%, respectively. Moreover, HS-SPME/GC-MS analysis was used to identify potential markers to distinguish the geographical origin of oranges. Although 28 out of 65 identified VOCs showed a different content in samples belonging to different classes, a pattern of analytes able to discriminate simultaneously samples of three origins was not found. These results indicate that the proposed MS-eNose method in combination with multivariate statistical analysis provided an effective and rapid tool for authentication of the orange's geographical origin.

Rapid screening of ochratoxin A in wheat by infrared spectroscopy.

The use of infrared spectroscopy for the screening of 229 unprocessed durum wheat samples naturally contaminated with OTA has been investigated. Samples were analysed by both Fourier Transform near- and mid-infrared spectroscopy (FT-NIR, FT-MIR). Partial-Least Squares-Discriminant Analysis (PLS-DA) and Principal Component-Linear Discriminant Analysis (PC-LDA) classification models were used to differentiate highly contaminated durum wheat samples from low contaminated ones and the performances of the resulting models were compared. The overall discrimination rates were higher than 94% for both FT-NIR and FT-MIR range by using a cut-off limit set at 2 µg/kg OTA, independently from the classification model used thus confirming the reliability of the two statistical approaches used. False compliant rates of 6% were obtained for both spectral ranges and both classification models. These findings indicate that FT-NIR, as well as FT-MIR analysis, might be a promising, inexpensive and easy-to-use screening tool to rapidly discriminate unprocessed wheat samples for OTA content.

In-house validation and small-scale collaborative study to evaluate analytical performances of multimycotoxin screening methods based on liquid chromatography-high-resolution mass spectrometry: Case study on Fusarium toxins in wheat.

A strong trend toward using highly selective mass spectrometry technologies for screening of multiple mycotoxins has been observed in recent years. In the present study, the process of validation of a multimycotoxin screening method based on liquid chromatography-high-resolution mass spectrometry method is presented. The method was intended for the simultaneous screening of the major Fusarium toxins (deoxynivalenol, 3- and 15-acetyl deoxynivalenol, T-2 and HT-2 toxins, zearalenone, enniatins A, A1, B, and B1, and beauvericin) in wheat. The sample preparation protocol was based on a double extraction (methanol followed by acetonitrile/water mixture) and purification through solid-phase extraction C18 column. To provide insights for full exploitation of the potential of the double-stage high-resolution mass spectrometry detection, a full-scan acquisition event followed by a sequence of 5 fragmentation events (variable data-independent acquisition) was set for mycotoxin detection, the latter to be exploited for confirmatory purposes. Method analytical performances were evaluated through in-house validation and small-scale interlaboratory study, designed according to Commission Regulation 519/2014/EU, setting performance requirements for screening methods for mycotoxins. Screening target concentrations were close to European Union maximum permitted or indicative levels. The in-house validation provided the precision of the response under repeatability conditions and the intermediate precision (both resulting lower than 30%), the cutoff value, and the rate of false suspect results for negative (free of the mycotoxin of interest) samples, which resulted lower than 0.1% in all cases. The collaborative study provided reproducibility and laboratory independent cutoff values. Analysis of reference materials proved method trueness and suitability for screening of the major Fusarium mycotoxins in wheat. Finally, the applicability of the full-scan/variable data-independent acquisition detection approach was successfully tested on a set of naturally contaminated wheat samples, where 2 characteristic product ions could be detected for all identified mycotoxins even at levels in the low µg/kg range.

Geographical origin discrimination of lentils (Lens culinaris Medik.) using 1H NMR fingerprinting and multivariate statistical analyses.

Lentil samples coming from two different countries, i.e. Italy and Canada, were analysed using untargeted 1H NMR fingerprinting in combination with chemometrics in order to build models able to classify them according to their geographical origin. For such aim, Soft Independent Modelling of Class Analogy (SIMCA), k-Nearest Neighbor (k-NN), Principal Component Analysis followed by Linear Discriminant Analysis (PCA-LDA) and Partial Least Squares-Discriminant Analysis (PLS-DA) were applied to the NMR data and the results were compared. The best combination of average recognition (100%) and cross-validation prediction abilities (96.7%) was obtained for the PCA-LDA. All the statistical models were validated both by using a test set and by carrying out a Monte Carlo Cross Validation: the obtained performances were found to be satisfying for all the models, with prediction abilities higher than 95% demonstrating the suitability of the developed methods. Finally, the metabolites that mostly contributed to the lentil discrimination were indicated.

The use of "LAST" operation in high risk patient.

BACKGROUND: The LAST operation, in spite of few drawbacks, represents a good option for single Left Anterior Descending (LAD) revascularization. This procedure does not allow multivessel revascularization, where hybrid procedure have been previous described. We report preliminary experience with the LAST operation performed in high risk patients. MATERIAL AND METHODS: From October 2004 to February 2005, 11 male high risk patients (mean age 74 +/- 8 years) underwent the LAST operation. Mean predicted death with EUROSCORE and Parsonnet score were 29% and 31% respectively. All patients had a proximal LAD lesion either not suitable for PTCA and multivessel coronary artery disease. The mean preoperative Ejection Fraction was 42 +/- 5% (27-55%). Four patients (36.4%) had previous surgical myocardial revascularization. An incision of about 6 cm was made in the appropriate intercostal space and the LIMA (Left Internal Mammary Artery) was harvested using a special costal retractor. After heparin administration the LIMA is distally divided to check the adequacy of the blood flow. Following the insertion of a temporary intracoronary shunt, the LIMA was LAD anastomosis was carried out with a continuous 8-0 polypropylene suture. RESULTS: No hospital or late mortality was observed. Uneventful conversion to midline sternotomy was necessary in one patient with low value of mammary flow. All patients were discharged within the first postoperative week. CONCLUSIONS: The use of the LAST operation enhances the role of minimally invasive surgery also in high risk patients who need coronary revascularization.