250 research outputs found

    NEUTRAL LOSS ANALYSIS OF AMINO ACIDS BY DESORPTION ELECTROSPRAY IONIZATION USING AN UNMODIFIED TANDEM QUADRUPOLE MASS SPECTROMETER.

    Get PDF
    A new method to analyze free amino acids using desorption electrospray ionization (DESI) has been implemented. The method is based on the neutral loss mode determination of underivatized amino acids using a tandem quadrupole mass spectrometer equipped with an unmodified atmospheric interface. Qualitative and quantitative optimization of DESI parameters, including ESI voltage, solvent flow rate, angle of collection and incidence, gas flow and temperatures, was performed for amino acids detection. The parameters for DESI analysis were evaluated using a mixture of valine, leucine, methionine, phenylalanine and tyrosine standards. A few microliters of this mixture were deposited on a slide, dried and analyzed at a flow rate of 2mL/min. The optimal ionization response was obtained using laboratory glass slides and an equivalent solution of water/methanol doped with 2% of formic acid. The method specificity was evaluated by comparing product ion spectra and neutral loss analysis of amino acids obtained either by DESI or by electrospray ionization flow injection analysis (ESI-FIA). To evaluate the quantitative response on amino acids analyzed by DESI, calibration curves were performed on amino acid standard solutions spiked with a fixed amount of labelled amino acids. The method was also employed to analyze free amino acids from blood spots, after a rapid solvent extraction without other sample pretreatment, from positive and negative subjects. The method enables one to analyze biological samples and to discriminate healthy subjects from patients affected by inherited metabolic diseases. The intrinsic high-throughput analysis of DESI represents an opportunity, because of its potential application in clinical chemistry.....

    An enhanced procedure for the analysis of organic binders in Pompeian's wall paintings from Insula Occidentalis

    Get PDF
    Abstract Quantitation of paint powders of ancient wall paintings is often hindered by the calcite contamination during samples withdrawal. To overcome this problem, a new approach was explored based on the mechanical pulverization of the paint powder followed by the evaluation of its true concentration, namely binders, pigments, and decaying compounds, from the comparison of the calcite FT-IR peak area at 2510 cm−1 with that of the corresponding underlying calcite used as calibrator. After extraction of the pulverized paint powder with polar and nonpolar solvents, liquid chromatography, gas chromatography with flame ionization detection, and gas chromatography–mass spectrometry were used to estimate the free amino acids, and fatty acids profiles. Compared to our previous investigation, the results obtained showed a better yield of the extracted organic materials as mg/kg of powder and also a qualitative improvement of the lipids profile

    Lipocalina e Delayed Graft Function nel paziente trapiantato renale

    Get PDF
    INTRODUZIONE: Il rene trapiantato è esposto agli effetti dell’ischemia-riperfusione responsabili di ritardata ripresa funzionale dell’organo (delayed graft function; DGF). DGF può incidere negativamente sull’evoluzione del rene trapiantato. Nel presente studio è stato valutato il ruolo della lipocalina urinaria quale predittore di DGF. MATERIALI E METODI: Sono stati valutati pazienti sottoposti a trapianto di rene da donatore cadavere. Prelievi ematici erano effettuati immediatamente prima del trapianto. Le urine erano raccolte per le 24 ore successive al trapianto. DGF era definita dalla necessità di trattamento dialitico entro la prima settimana dal trapianto. RISULTATI: Sono stati valutati 20 pazienti. I pazienti che avevano una rapida ripresa funzionale del rene trapiantato (NO-DGF) erano 14 (70%). DGF era osservata in 6 pazienti. L’età media nei DGF era superiore (58±6 Vs 51±11, p=0.001). Nei pazienti DGF risultavano significativamente ridotta la diuresi (57±35 Vs 4150 ± 2230 ml/24h; p=0.001) e la escrezione urinaria di creatinina (191±184 Vs 683±660 mg/24h; p=0.001), misurate nel primo giorno successivo al trapianto. Non erano osservate significative differenze tra pazienti DGF e NO-DGF per la escrezione urinaria di lipocalina (1,20±2,20 Vs 2,44±4,0 mg/24h; p<0.20). In univariata, DGF risultava associata negativamente alla diuresi (r2=-0.795, p=0.001) ed alla escrezione urinaria di creatinina (r2=-0.480, p=0.037) e positivamente all’età (r2=0.446, p=0.049). In multivariata diuresi (p=0.014) ed escrezione urinaria di creatinina (p=0.039) erano associati a DFG. CONCLUSIONI: Lipocalina urinaria, misurata nel giorno successivo al trapianto renale, non è biomarcatore predittivo di DGF. I risultati del presente studio possono essere stati influenzati dal campione limitato di pazienti e dalla bassa incidenza di DGF

    Social isolation triggers oxidative status and impairs systemic and hepatic insulin sensitivity in normoglycemic rats

    Get PDF
    Drug-naïve psychotic patients show metabolic and hepatic dysfunctions. The rat social isolation model of psychosis allows to investigate mechanisms leading to these disturbances to which oxidative stress crucially contributes. Here, we investigated isolation-induced central and peripheral dysfunctions in glucose homeostasis and insulin sensitivity, along with redox dysregulation. Social isolation did not affect basal glycemic levels and the response to glucose and insulin loads in the glucose and insulin tolerance tests. However, HOMA-Index value were increased in isolated (ISO) rats. A hypothalamic reduction of AKT phosphorylation and a trend toward an increase in AMPK phosphorylation were observed following social isolation, accompanied by reduced GLUT-4 levels. Social isolation also induced a reduction of phosphorylation of the insulin receptor, of AKT and GLUT-2, and a decreased phosphorylation of AMPK in the liver. Furthermore, a significant reduction in hepatic CPT1 and PPAR-α levels was detected. ISO rats also showed significant elevations in hepatic ROS amount, lipid peroxidation and NOX4 expression, whereas no differences were detected in NOX2 and NOX1 levels. Expression of SOD2 in the mitochondrial fraction and SOD1 in the cytosolic fraction was not altered following social isolation, whereas SOD activity was increased. Furthermore, a decrease of hepatic CAT and GSH amount was observed in ISO rats compared to GRP animals. Our data suggest that the increased oxidant status and antioxidant capacity modifications may trigger hepatic and systemic insulin resistance, by altering signal hormone pathway and sustaining subsequent alteration of glucose homeostasis and metabolic impairment observed in the social isolation model of psychosis

    Serum amino acid profiles in normal subjects and in patients with or at risk of Alzheimer dementia

    Get PDF
    Background/Aims: Abnormalities in the plasma amino acid profile have been reported in Alzheimer disease (AD), but no data exist for the prodromal phase characterized by subjective memory complaint (SMC). It was our aim to understand if serum amino acid levels change along the continuum from normal to AD, and to identify possible diagnostic biomarkers. Methods: Serum levels of 15 amino acids and 2 organic acids were determined in 4 groups of participants – 29 with probable AD, 18 with mild cognitive impairment (MCI), 24 with SMC, and 46 cognitively healthy subjects (HS) – by electrospray tandem mass spectrometry. Results: Glutamate, aspartate, and phenylalanine progressively decreased, while citrulline, argi­ninosuccinate, and homocitrulline progressively increased, from HS over SMC and MCI to AD. The panel including these 6 amino acids and 4 ratios (glutamate/citrulline, citrulline/phenylalanine, leucine plus isoleucine/phenylalanine, and arginine/phenylalanine) discriminated AD from HS with about 96% accuracy. Other panels including 20 biomarkers discriminated SMC or MCI from AD or HS with an accuracy ranging from 88 to 75%. Conclusion: Amino acids contribute to a characteristic metabotype during the progression of AD along the continuum from health to frank dementia, and their monitoring in elderly individuals might help to detect at-risk subjects

    Short-Term Physiological Effects of a Very Low-Calorie Ketogenic Diet: Effects on Adiponectin Levels and Inflammatory States

    Get PDF
    Adipose tissue is a multifunctional organ involved in many physiological and metabolic processes through the production of adipokines and, in particular, adiponectin. Caloric restriction is one of the most important strategies against obesity today. The very low-calorie ketogenic diet (VLCKD) represents a type of caloric restriction with very or extremely low daily food energy consumption. This study aimed to investigate the physiological effects of a VLCKD on anthropometric and biochemical parameters such as adiponectin levels, as well as analyzing oligomeric profiles and cytokine serum levels in obese subjects before and after a VLCKD. Twenty obese subjects were enrolled. At baseline and after eight weeks of intervention, anthropometric and biochemical parameters, such as adiponectin levels, were recorded. Our findings showed a significant change in the anthropometric and biochemical parameters of these obese subjects before and after a VLCKD. We found a negative correlation between adiponectin and lipid profile, visceral adipose tissue (VAT), C-reactive protein (CRP), and pro-inflammatory cytokines such as tumor necrosis factor-a (TNF-a), which confirmed the important involvement of adiponectin in metabolic and inflammatory diseases. We demonstrated the beneficial short-term effects of a VLCKD not only in the treatment of obesity but also in the establishment of obesity-correlated diseases

    Functional results of exclusive interventional radiotherapy (brachytherapy) in the treatment of nasal vestibule carcinomas.

    Get PDF
    Surgery, external beam radiotherapy (EBRT), and interventional radiotherapy (IRT, BrachyTherapy BT) are the current therapeutic options for nose vestibule (NV) squamous cell carcinoma (SCC). In this article, we evaluate the nose functional parameters of patients affected by SCCs of the NV, primarily treated by interstitial IRT comparing them with healthy controls and with patients treated with intensity-modulated EBRT.Ten patients treated by using IRT (group 1), 10 healthy controls and eight patients treated by EBRT (group 2) on the region of the nose were submitted to clinical evaluation (with the NOSE scale score), rhinomanometry, olfactory testing, nasal citology, and evaluation of mucociliary clearance through saccharine test.No long-term skin or cartilaginous toxicity are recorded. The olfactometry threshold discrimination identification TDI is lower in EB group. The mean NOSE scale score was significantly higher in group 2 than in group 1 and healthy controls (p0.05). The distribution of cytologic patterns resulted significantly different as well. Patients treated by EB have a significantly impaired mucociliary clearance, with a mean time for the transport of the stained marker, which is more than double in the patients treated by EB than in those treated with IRT (p0.001).Nasal function and cytological findings are significantly better, substantially preserved, in patients treated by IRT than in those treated by EBRT, bringing new relevant evidence for the establishment of interstitial IRT as the new standard for the treatment of the primary lesion in cT1 and cT2 -Wang staging NV SCCs

    Sclerotherapy with polidocanol microfoam in head and neck venous and lymphatic malformations

    Get PDF
    Objective. Polidocanol sclerotherapy of head and neck venous malformations (VMs) and lymphatic malformations (LMs) has been reported only in limited series. In this manuscript we evaluated the efficacy and safety of polidocanol sclerotherapy in a series of head and neck venous and lymphatic malformations. Methods. This retrospective observational study analysed data on 20 head and neck VMs and LMs that underwent to percutaneous or endoscopic intra-lesional 3% polidocanol microfoam sclerotherapy at our institution. Clinical response was ranked as excellent, moderate and poor based on volume reduction by MRI and resolution of symptoms. Results. The median volume decreased from 19.3 mL to 5.8 mL after sclerotherapy (mean volume reduction: 72.98 ± 16.1%). An excellent-moderate response was observed in 94.4% of cases. We observed a mean volume reduction of 79.5 ± 16.1 in macrocystic LMs, of 76.1 ± 13.0% in VMs, of 60.5 ± 10.9% in mixed lymphatic ones and 42.5% in microcystic lymphatic ones. Conclusions. Polidocanol sclerotherapy appears to be an effective and safe treatment for venous and lymphatic head and neck malformations. We observed the best responses in macrocystic LMs and VMs, whereas mixed lymphatic ones showed a moderate response and microcystic lymphatic ones a poor response
    • …
    corecore