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Proteomica e metallomica: studio del tessuto placentare in presenza di diabete gestazionale
Full text linkThe present research work concerns the development of new analytical methods aimed to the study of the proteome and the metallome of placental tissue and the evaluation of its possible modifications and/or alterations due to gestational diabetes.
Proteomics analysis was performed by different experimental approaches based on mass spectrometry (ESI-MS and MALDI-MS), and on one- and two-dimensional electrophoresis. These analytical techniques are presently the most suitable experimental approaches to be used in omics applications thanks to their high sensitivity and specificity. Results showed the presence of protein species differently expressed in the case of gestational diabetes; in particular, it was measured an increment of the chorionic somatomammotrophin level and a decrease in the concentration of alpha, beta and gamma chains of fibrinogen and tubulointerstitial nephritis antigen-like in the case of placental tissues impaired by GDM.
Metallomics analysis was carried out by ICP-MS, an analytical technique characterized by high sensitivity and robustness. The study reported an increased concentration of Se and a decrease of Cd level in pathological placental tissues compared to healthy ones. Furthermore, this approach allowed the evaluation of the effectiveness of the sampling procedure, the influence of the blood on the obtained results and showed the importance of other parameters, such as the lifestyle of the patients, in the statistical evaluation of the experimental data.
In conclusion, the obtained data might be useful for the study and the explanation of the biochemical processes that characterize the disease and for the determination of new biomarkers aimed to the development of innovative diagnostic tests for gestational diabetes
From Au(11) to Au(13): Tailored Synthesis of Superatomic Di-NHC/PPh(3)-Stabilized Molecular Gold Nanoclusters
Full text link[Image: see text] Herein, we report a new method to synthesize molecular gold nanoclusters (AuNCs) stabilized by phosphine (PR(3)) and di-N-heterocyclic carbene (di-NHC) ligands. The interaction of di-NHC gold(I) complexes, with the general formula [(di-NHC)Au(2)Cl(2)] with well-known [Au(11)(PPh(3))(8)Cl(2)]Cl clusters provides three new classes of AuNCs through a controllable reaction sequence. The synthesis involves an initial ligand metathesis reaction to produce [Au(11)(di-NHC)(PPh(3))(6)Cl(2)](+) (type 1 clusters), followed by a thermally induced rearrangement/metal complex addition with the formation of Au(13) clusters [Au(13)(di-NHC)(2)(PPh(3))(4)Cl(4)](+) (type 2 clusters). Finally, an additional metathesis process yields [Au(13)(di-NHC)(3)(PPh(3))(3)Cl(3)](2+) (type 3 clusters). The electronic and steric properties of the employed di-NHC ligand affect the product distribution, leading to the isolation and full characterization of different clusters as the main product. A type 3 cluster has been also structurally characterized and was preliminarily found to be strongly emissive in solution
A preliminary study on human placental tissue impaired by gestational diabetes: A comparison of gel-based versus gel-free proteomics approaches
No full textMaternal, placental and cordonal metallomic profiles in gestational diabetes mellitus
No full text76 pregnant women, among them 38 affected by gestational diabetes mellitus (GDM) and 38 control subjects, were recruited at the University Hospital of Padua (Italy). Placenta samples, maternal whole blood and umbilical cord whole blood were collected after delivery and analysed via ICP-MS to determine the metallome, i.e. the whole elemental content. Results were statistically evaluated to evidence the correlation between the elemental concentrations in all samples and the presence of the disease. The results obtained in whole cord blood showed that many elements were correlated with GDM: Ca, Cu, Na, and Zn were present in higher concentration in GDM cord blood than in control samples, whereas Fe, K, Mn, P, Rb, S and Si showed an opposite trend. It was also highlighted that the cord blood from GDM patients exhibited an elemental composition more similar to that of the mother blood compared with the cord blood from control subjects. These results, in part interpreted in the light of the literature, open the possibility to use cord blood as a GDM marker, thus helping to delineate more accurate nutritional guidelines for pregnant women and to explain the biochemical processes occurring in the fetus and placenta during GDM
Derivatization, an Applicable Asset for Conventional HPLC Systems without MS Detection in Food and Miscellaneous Analysis
No full textOne of the most valuable practices for analyzing not-so-analytical-friendly analytes in complex, heterogenous matrices is derivatization. Availability of numerous derivatizing reagents (DRs) makes the modification of analyte more exploitable in terms of an analytical perspective. A wide array of derivatization techniques like pre or post-column, in-situ, enzymatic, ultrasound-assisted, microwave-assisted, photochemical derivatization has added much-needed methodological strength in analyzing intricate analytical matrices (food, water, and soil). In recent years, analytical chemistry has achieved greater heights through the development of new sensitive methods with simple conventional instruments like High-Performance Liquid Chromatography (HPLC) devoid of Mass detectors. The prompt availability of these straightforward instruments also makes it a favorable option for routine analysis in food, environmental, bioanalytical chemistry. Analyzing food, environmental or bioanalytical specimen has some of the most problematic aspects, like the low concentration of the analytes accompanied by not too suitable analytical properties. Even though conventional HPLC lacks the required sensitivity but merger with derivatization can lead to a remarkable increase in sensitivity. In recent years there has been a lot of application of diverse derivatizations to increase the sensitivity and selectivity of the analyte for available instruments, resulting in notable findings. Therefore, this review describes the application of derivatization principles in the analysis of analytes in food and additional matrices using conventional HPLC instruments such as HPLC-UV, HPLC-DAD, and HPLC-FD. In this article, we will briefly review the different modes and multiple types of derivatizing reagents with their mechanisms and importance for encouraging the use of established HPLC instruments
Effects of the Fragrance Galaxolide on the Biomarker Responses of the Clam Ruditapes philippinarum
Full text linkThe musk fragrance Galaxolide® (HHCB) is widely used in personal care and household products. Its large use leads to a continuous release of the compound into aquatic environments. Although some studies on the presence of HHCB in ecosystems and biota have been conducted, limited data about its effects on organism biomarkers are available. This study aimed at investigating both cellular and biochemical effects of HHCB in the clam Ruditapes philippinarum. Mussels were exposed for 7, 14 and 21 days to 100 ng/L and 500 ng/L of HHCB in seawater, and the effects on haemocyte parameters and antioxidant enzyme activities in the gills and digestive gland were evaluated. In addition, the neurotoxic potential of HHCB and its capacity to cause oxidative damage to proteins were assessed. Overall, our results demonstrated that exposure to HHCB was able to induce changes in biomarker responses of mussels, mainly at the cellular level
From a validated targeted method to a retrospective UHPLC-HRMS non-targeted analysis unveiling COVID-19-related contaminants in clams. Have we bias in marine model organisms for ecotoxicological studies?
Full text link: This study explores a retrospective non-targeted analysis (NTA), based on Ultra High-Performance Liquid Chromatography coupled to High-Resolution Mass Spectrometry (UHPLC-HRMS), to assess hidden chemicals of emerging concern (CECs) in marine model organisms. Conventional ecotoxicological studies do not include evaluating the natural habitats of the collected organisms, missing the possibility of highlighting unexpected pollutants, and thus compromising the correctness and reliability of the experimental results. In this paper we reprocessed samples previously collected from the Venice Lagoon for ecotoxicological studies and used for targeted analysis of three bisphenols-related compounds (i.e. BPS, BPF and BPAF) on seawater and specimens of the clam Ruditapes philippinarum. Results from the validation were the following: accuracy, expressed as percentage recoveries (R%), in the range 80%<120% for all the considered compounds and matrices, and precision, expressed as relative standard deviation of the absolute areas of IS, was <20% for clams (N=24) and <15% for seawater (N=30). LODs ranged from 5 to 50 ng/L for seawater and 5 to 12 ng/g for clam tissues. After validation, a retrospective NTA was carried out on control samples, showing the presence of some CECs, i.e. Lopinavir, Ritonavir, DEHS, and DEHA, two antiviral drugs used during the COVID-19 pandemic and two plasticizers, respectively, reported here for the first time in the Mediterranean Sea. CEC identifications were confirmed by matching MS/MS spectra with libraries. The present study emphasizes the importance of retrospective investigations to describe the contamination scenario of environmental matrices and the related effect in biota, to correctly address studies on model animals, also including possible "cocktail effects"
Accurate pH Monitoring of Highly Concentrated Saline Aqueous Solutions (Seawater-like) with a pH Colorimetric Sensor Array
No full textA pH colorimetric sensor array (CSA) was prepared on a nitrocellulose membrane and used for accurate pH measurement in highly concentrated saline solutions. The CSAs consisted of sensing spots made of a suitable OrMoSil polymer prepared from organo-fluorinated-silane precursors and/or organosilane with tetraethyl orthosilicate hosting an acid-base indicator. Four CSAs were prepared: D, 1F, 2F, and 3F. In D, a nonfluorinated organosilane was present. From 1F to 3F, the concentration of the fluorinated organosilane increased and improved the pH measurement accuracy in highly saline concentrations. No recalibrations were required, and the analytical signal was stable in time. D, 1F, 2F, and 3F were deposited in triplicate, and they were prepared to work in the seawater pH interval (7.50-8.50). The use of fluorinated precursors led to a lower pH prediction error and tailored the interval of the CSA at more basic pH values so that the inflection points of the sigmoidal calibrations of D, 1F, 2F, and 3F moved from 6.97 to 7.98. The overall pH prediction error was 0.10 pH (1F), 0.02 pH (2F), and 0.04 pH units (3F). The CSAs were stable, reversible, reusable, and independent of salinity (S) between 20 and 40. The performances of the CSA were compared with those of a glass electrode, whose pHNIST values were converted in the pHSWS scale through a conversion equation. Being unaffected by the typical drawback of the glass electrode, the CSAs can be used directly in seawater real samples, and it validated the proposed conversion equation
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Methiocarb metabolites are systemically distributed throughout corn plants grown from coated seeds
Full text linkSystemic insecticides such as neonicotinoids are widely used in seed coating practices for pest control in many crops, e.g., corn. Their success is due to their ability to protect the whole plant, from the roots to the upper leaves, but their use at high amounts is causing possible adverse effects on non-target animals exposed to contaminated pollen, nectar, leaves, and dust emitted during sowing. In 2018, the European Union banned some neonicotinoids and fipronil as seed coating insecticides in open fields. Consequently, the methylcarbamate methiocarb and less-toxic neonicotinoids, e.g., thiacloprid, have been authorized and largely used as alternative pesticides for corn seed coating. Here, an analytical protocol based on QuEChERS extraction/purification procedure and analysis by liquid chromatography-mass spectrometry has been optimized for the identification and the quantification of methiocarb, thiamethoxam, thiacloprid, and their metabolites in guttation drops, the xylem fluid excreted at leaf margins, and in leaves of corn plants grown from coated seeds. Although methiocarb is a non-systemic pesticide, we unexpectedly found high concentrations of its metabolites in both guttations and leaves, whereas methiocarb itself was below detection limits in most of the samples. The methiocarb main metabolite, methiocarb sulfoxide, was found at a mean concentration of 0.61 ± 1.12 µg mL−1 in guttation drops and 4.4 ± 2.1 µg g−1 in leaves. Conversely, parent compounds of neonicotinoids (thiamethoxam, thiacloprid) are systemically distributed in corn seedlings. This result raises safety concerns given that methiocarb sulfoxide is more toxic than the parent compound for some non-target species
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