Application of ATR-FT-MIR for tracing the geographical origin of honey produced in the Maltese Islands

Maltese honey has been produced, marketed, and sold as an exclusive local gourmet food product for countless years. Yet, thus far, no study has evaluated the individuality of this local food product. The evaluation of the parameters and properties which characterise the provenance and floral source of honey have been the subject of various studies worldwide, owing to the price and potential beneficial properties of this food product. Models analysing the potential of attenuated total reflection mid-infrared (ATR-FT-MIR) spectroscopy in discriminating and classifying local honey from that of foreign origin were investigated using 21 Maltese honey samples and 49 honey samples collected from abroad (Sicily, Greece, Sweden, Italy, France, Estonia and other samples of mixed geographical origin). Through a combination of spectroscopic techniques, spectral transformations, variable selection and partial least squares discriminant analysis (PLS-DA), chemometric models which successfully classified the provenance of local and non-local honey were developed. The results of these models were also corroborated with other classification and pattern recognition techniques, such as linear discriminate analysis (LDA), support vector machines (SVM) and feed-forward artificial neural networks (FF-ANN).peer-reviewe

The first identification of the uniqueness and authentication of Maltese extra virgin olive oil using 3D-fluorescence spectroscopy coupled with multi-way data analysis

The potential application of multivariate three-way data analysis techniques, namely parallel factor analysis (PARAFAC) and discriminant multi-way partial least squares regression (DN-PLSR), on three-dimensional excitation emission matrix (3D-EEM) fluorescent data were used to identify the uniqueness and authenticity of Maltese extra virgin olive oil (EVOO). A non-negativity constrained PARAFAC model revealed that a four-component model provided the most appropriate solution. Examination of the extracted components in mode 2 and 3 showed that these belonged to different fluorophores present in extra virgin olive oil. Application of linear discriminate analysis (LDA) and binary logistic regression analysis on the concentration of the four extracted fluorophores, showed that it is possible to discriminate Maltese EVOOs from non-Maltese EVOOs. The application of DN-PLSR provided superior means for discrimination of Maltese EVOOs. Further inspection of the extracted latent variables and their variable importance plots (VIPs) provided strong proof of the existence of four types of fluorophores present in EVOOs and their potential application for the discrimination of Maltese EVOOs.peer-reviewe

Application of ATR-FT-MIR for Tracing the Geographical Origin of Honey Produced in the Maltese Islands

Maltese honey has been produced, marketed, and sold as an exclusive local gourmet food product for countless years. Yet, thus far, no study has evaluated the individuality of this local food product. The evaluation of the parameters and properties which characterise the provenance and floral source of honey have been the subject of various studies worldwide, owing to the price and potential beneficial properties of this food product. Models analysing the potential of attenuated total reflection mid-infrared (ATR-FT-MIR) spectroscopy in discriminating and classifying local honey from that of foreign origin were investigated using 21 Maltese honey samples and 49 honey samples collected from abroad (Sicily, Greece, Sweden, Italy, France, Estonia and other samples of mixed geographical origin). Through a combination of spectroscopic techniques, spectral transformations, variable selection and partial least squares discriminant analysis (PLS-DA), chemometric models which successfully classified the provenance of local and non-local honey were developed. The results of these models were also corroborated with other classification and pattern recognition techniques, such as linear discriminate analysis (LDA), support vector machines (SVM) and feed-forward artificial neural networks (FF-ANN)

RNA profiling of human growth hormone-secreting and non-functioning pituitary adenomas reveals novel and differentially expressed immune related genes

Pituitary neuroendocrine tumours (PitNETs) are broadly classified as non-functioning pituitary adenomas (NFPAs) and functional pituitary adenomas (FPAs) which include growth hormone secreting adenomas (GHPAs). Since the role of the immune system in PitNET pathogenesis is still poorly understood, we employed RNA-sequencing technology to unravel differentially expressed genes in GHPAs and NFPAs. Here we present an RNA-sequencing workflow of GHPAs (n=3) and NFPAs (n=7) which revealed a total of 7945 differentially expressed genes. Reactome, Gene Ontology and KEGG pathway analysis further revealed 57 genes involved in immune regulation. These genes fell into functional categories of chemokines, cytokines, interleukins, signal transduction and adhesion molecules. 6 immune genes including GATA3, CCL3, and CXCL9 were selected for further validation by qRT-PCR in 14 additional PitNET samples. A number of possible pathways implicated in PitNET functioning were also highlighted. The most significant were ‘T 1 and T 2 cell differentiation’, ‘cytokine-cytokine receptor pathway’, and ‘chemokine receptors bind chemokines’. Through our findings, we highlight distinct gene expression profiles in NFPAs and GHPAs and suggest that some of these genes could be considered as novel PitNET diagnostic markers for these two subtypes. We are currently validating these novel markers by immunohistochemistry in an array of PitNET subtypes.peer-reviewe

TNFα production or expression by macrophages (isolated from uninfected immunocompetent mice) upon interaction with resting conidia of parental (<i>ku80</i>) and <i>ags</i>Δ_<i>5T</i> strains or <i>ags</i>Δ_<i>5T</i> conidial NaCl extract (3.2 µg proteins) respectively.

<p>(A) TNFα was quantified after 5 h incubation of the conidia with macrophages; (B) Relative expression of TNFα assessed by real time RT-PCR in total RNA from macrophages after 5 h incubation of the <i>ags</i>Δ_<i>5T</i> conidial NaCl extract with macrophages. NaCl supernatant from <i>ku80</i> resting conidia incubated for 2 h in 0.5M NaCl was used as a control. NS: Non-stimulated. *, P<0.05.</p

Surface analysis of resting conidia of <i>ags</i>Δ_<i>5T</i> mutant and parental (<i>ku80</i>) strains.

<p>(A): height images (z-range = 1 µm; recorded in water with silicon nitride tips). Atomic Force Microscopy (AFM) images showing the amorphous surface without the rodlet layer on the triple <i>ags</i>Δ_<i>5T</i> mutant conidia whereas the rodlet are observed on the parental strain conidial surface. (B): TEM observations. Note the presence of an extracellular material on the surface of the <i>ags</i>Δ_<i>5T</i> conidia (arrow); CW: cell wall. (C): SDS-PAGE (15% gel) of Hydrofluoric acid (HF) extracts of rodlets from resting conidia showing the two bands, 16 kDa and 14.5 kDa of RodAp classically seen from HF treatment of the conidia <a href="http://www.plospathogens.org/article/info:doi/10.1371/journal.ppat.1003716#ppat.1003716-Aimanianda1" target="_blank">[10]</a>. Data are representative of at least three independent experiments.</p

Phagocytosis activity by isolated macrophages from uninfected mice against resting conidia of <i>ags</i>Δ_<i>5T</i> and parental (<i>ku80</i>) strains.

<p>Index of phagocytosis is expressed in number of conidia per alveolar macrophage after 1*, P<0.05.</p

Cyclophosphamide immunosuppressed mice and anti-Ly6G treated neutropenic mice infected with resting conidia of <i>ags</i>Δ_<i>5T</i> and parental (<i>ku80</i>) strains.

<p>(A–C) Cyclophosphamide immunosuppressed mice; (D–E) anti-Ly6G treated neutropenic mice; (A) Survival (%) and (B) fungal growth estimated as CFUs in lung. (C and E) lung histology (periodic acid-Schiff-staining). Note the polymorphonuclear cells and mononuclear infiltrates surrounding the bronchi in <i>ku80</i> infected lung. (D) Histological appearance of lungs of anti-Ly6G neutropenic mice infected with conidia of <i>ags</i>Δ_<i>5T</i> and <i>ku80</i> (Gomori's methanamine silver-staining). Note the absence of mycelial development of <i>ags</i>Δ_<i>5T</i> conidia in neutropenic mice. Data are representative of at least three independent experiments. *: p<0.05.</p

Imaging and adhesive properties of <i>A. fumigatus</i> resting conidia of the parental strain and <i>ags</i>Δ_<i>5T</i> mutant.

<p>Structural changes of <i>ags</i>Δ_<i>5T</i> correlate with a loss of cell surface adhesive properties. (A–C) parental strain; (D–F) <i>ags</i>Δ_<i>5T</i> mutant; (A, D) height images (z-range = 1 µm; recorded in water with silicon nitride tips); (B, E) adhesion force maps (z-range: 5 nN) corresponding to the height image; (C, F) Representative force-distance curves and adhesion force histograms (n = 1024) recorded on the surface of parental strain (C) and <i>ags</i>Δ_<i>5T</i> (F).</p