Sviluppo e applicazione di una nuova metodica HPLC-FL per la determinazione di melatonina e N-acetilserotonina nel tessuto retinico.

Lo scopo di questo lavoro di tesi è stato lo sviluppo di una nuova metodica analitica per la valutazione quali-quantitativa della N-acetil-serotonina (NAS) e della melatonina (MEL) mediante HPLC con rilevatore fluorimetrico per la loro determinazione nel tessuto retinico in varie condizioni fisiologiche. Sia la MEL che la NAS sono prodotte nella retina, dove sono presenti recettori specifici per queste molecole, e dove possono inoltre esercitare un ruolo antiossidante,sono infatti capaci di proteggere i fotorecettori dallo stress ossidativo innescato dalla luce che viene focalizzata sui segmenti esterni dei fotorecettori, ricchi di acidi grassi polinsaturi particolarmente suscettibili alla lipoperossidazione, come l'acido docosaesaenoico. Considerato quindi che, sia la NAS che la MEL con diversi meccanismi, sembrano implicate nella funzionalità e nella vitalità delle cellule retiniche, abbiamo ritenuto interessante valutare la regolazione della produzione di entrambi a questo livello, per ottenere utili indicazioni sul ruolo delle azioni mediate da recettori rispetto alle loro azioni antiossidanti. Le analisi sono state effettuate su tre diversi ceppi di topi quali: C57BL/6 e topi ottenuti incrociando animali del ceppo C57BL/10 (privi di NAS e MEL) con topi del ceppo AJ che esprimono sia NAS che MEL, questo ceppo misto era disponibile in due varianti, con (MUT) e senza (WT) una mutazione del gene Cacna2d4

Clinical effectiveness of hymenoptera venom immunotherapy

Treatment failure during venom immunotherapy (VIT) may be associated with a variety of risk factors. Our aim was to evaluate the association of baseline serum tryptase concentration (BTC) and of other parameters with the frequency of VIT failure during the maintenance phase. In this observational prospective multicenter study, we followed 357 patients with established honey bee or vespid venom allergy after the maintenance dose of VIT had been reached. In all patients, VIT effectiveness was either verified by sting challenge (n = 154) or patient self-reporting of the outcome of a field sting (n = 203). Data were collected on BTC, age, gender, preventive use of anti-allergic drugs (oral antihistamines and/or corticosteroids) right after a field sting, venom dose, antihypertensive medication, type of venom, side effects during VIT, severity of index sting reaction preceding VIT, and duration of VIT. Relative rates were calculated with generalized additive models. 22 patients (6.2%) developed generalized symptoms during sting challenge or after a field sting. A strong association between the frequency of VIT failure and BTC could be excluded. Due to wide confidence bands, however, weaker effects (odds ratios <3) of BTC were still possible, and were also suggested by a selective analysis of patients who had a sting challenge. The most important factor associated with VIT failure was a honey bee venom allergy. Preventive use of anti-allergic drugs may be associated with a higher protection rate. It is unlikely that an elevated BTC has a strong negative effect on the rate of treatment failures. The magnitude of the latter, however, may depend on the method of effectiveness assessment. Failure rate is higher in patients suffering from bee venom allergy

Is There a Crucial Link Between Vitamin D Status and Inflammatory Response in Patients With COVID-19?

Background: Hypovitaminosis D has been suggested to play a possible role in coronavirus disease 2019 (COVID-19) infection. Methods: The aim of this study is to analyze the relationship between vitamin D status and a biochemical panel of inflammatory markers in a cohort of patients with COVID-19. A secondary endpoint was to evaluate the correlation between 25OHD levels and the severity of the disease. Ninety-three consecutive patients with COVID-19-related pneumonia were evaluated from March to May 2020 in two hospital units in Pisa, in whom biochemical inflammatory markers, 25OHD levels, P/F ratio at nadir during hospitalization, and complete clinical data were available. Results: Sixty-five percent of patients presented hypovitaminosis D (25OHD ≤ 20 ng/ml) and showed significantly higher IL-6 [20.8 (10.9–45.6) vs. 12.9 (8.7–21.1) pg/ml, p = 0.02], CRP [10.7 (4.2–19.2) vs. 5.9 (1.6–8.1) mg/dl, p = 0.003], TNF-a [8.9 (6.0–14.8) vs. 4.4 (1.5–10.6) pg/ml, p = 0.01], D-dimer [0.53 (0.25–0.72) vs. 0.22 (0.17–0.35) mg/l, p = 0.002], and IL-10 [3.7 (1.8–6.9) vs. 2.3 (0.5–5.8) pg/ml, p = 0.03]. A significant inverse correlation was found between 25OHD and all these markers, even adjusted for age and sex. Hypovitaminosis D was prevalent in patients with severe ARDS, compared with the other groups (75% vs. 68% vs. 55%, p &lt; 0.001), and 25OHD levels were lower in nonsurvivor patients. Conclusions: The relationship between 25OHD levels and inflammatory markers suggests that vitamin D status needs to be taken into account in the management of these patients. If vitamin D is a marker of poor prognosis or a possible risk factor with beneficial effects from supplementation, this still needs to be elucidated

Mannose as a biomarker of coronary artery disease: Angiographic evidence and clinical significance

Background High mannose has previously associated with insulin resistance and cardiovascular disease (CVD). Our objective is to establish whether mannose is associated with anatomical evidence of coronary artery disease (CAD). Methods Plasma mannose concentrations were measured by liquid chromatography/tandem mass spectrometry in a discovery cohort (n = 513) and a validation cohort (n = 221) of carefully phenotyped individuals. In both cohorts CAD was quantitated using state-of-the-art imaging techniques (coronary computed coronary tomography angiography (CCTA), invasive coronary angiography and optical coherence tomography). Information on subsequent CVD events/death was collected. Associations of mannose with angiographic variables and biomarkers were tested using univariate and multivariate regression models. Survival analysis was performed using the Kaplan-Meier estimator. Results Mannose was related to indices of CAD and features of plaque vulnerability. In the discovery cohort, mannose was a marker of quantity and quality of CCTA-proven CAD and subjects with a mannose level in the top quartile had a significantly higher risk of CVD events/death (p = 3.6e-5). In the validation cohort, mannose was significantly associated with fibrous cap thickness &lt; 65 \u3bcm (odds ratio = 1.32 per each 10 \u3bcmol/L mannose change [95% confidence interval, 1.05\u20131.65]) and was an independent predictor of death (hazard ratio for mannose 65vs &lt; 84.6 \u3bcmol/L: 4.0(95%CI, 1.4\u201311.3), p = 0.006)

Educomunicação e suas áreas de intervenção: Novos paradigmas para o diálogo intercultural

oai:omp.abpeducom.org.br:publicationFormat/1O material aqui divulgado representa, em essência, a contribuição do VII Encontro Brasileiro de Educomunicação ao V Global MIL Week, da UNESCO, ocorrido na ECA/USP, entre 3&nbsp;e 5 de novembro de 2016. Estamos diante de um conjunto de 104 papers executivos, com uma média de entre 7 e 10 páginas, cada um. Com este rico e abundante material, chegamos ao sétimo e-book publicado pela ABPEducom, em seus seis primeiros anos de existência. A especificidade desta obra é a de trazer as “Áreas de Intervenção” do campo da Educomunicação, colocando-as a serviço de uma meta essencial ao agir educomunicativo: o diálogo intercultural, trabalhado na linha do tema geral do evento internacional: Media and Information Literacy: New Paradigms for Intercultural Dialogue

The role of tandem mass spectrometry in clinical chemistry: quantification of steroid hormones and vitamin D

Nowadays tandem mass spectrometry coupled to liquid chromatography is considered as the "gold standard" technique for steroid hormones quantification in biological fluids. Its emerging role in the clinical laboratories is mainly due to its capability to overcome the main limitations of the widespread immunoassays (IAs), providing, at the same time, the simultaneous quantification of several steroids of interest. This is a very important feature, as it allows, just in a single analysis, the monitoring of some key steroids in a metabolic pathway. In this chapter, we will describe the instrumental layout to be used in the measurement of clinically relevant steroids or steroid panels, and we will discuss the advantages and disadvantages of tandem mass spectrometry with respect to the main IA-based assays. The quantification of the main metabolites of vitamin D, 25-hydroxyvitamin D3, which is considered a steroid hormone, is also discussed in the chapter. Applications concerning 11β-HSD enzyme activity, 21-hydroxylase deficiency in newborns, hypovitaminosis D in patients with heart failure and vitamin D intoxication are discussed

Quantification of D-mannose in plasma: Development and validation of a reliable and accurate HPLC-MS-MS method

The present paper describes the development and the validation process – in compliance with the EMA guidelines – of a method based on tandem mass spectrometry coupled to liquid chromatography for the accurate quantification of mannose in human plasma samples. The quick sample preparation procedure, simplified by the absence of any derivatization step, makes the assay suitable for routine use in a clinical chemistry laboratory. The method validation yielded satisfactory selectivity, with a good separation of mannose from its epimers (glucose and galactose), linearity over the whole concentration range of interest (0.31–40 μg/mL), reproducibility with RSD <10%, and accuracy in the range 96 – 104%. Instrumental LLOD (0.31 μg/mL) and LLOQ (1.25 μg/mL) were good enough to detect endogenous plasma mannose levels and in agreement with recent data from the literature. Sensitivity was affected by a 5-fold dilution factor, which, if necessary, can be reduced. The method robustness was proven in more than 600 injections, most of them being of plasma samples, used also to assess the reference ranges in healthy subjects (9.93 ± 3.37 µg/mL) and type 2 diabetic patients (23.47 ± 6.19 µg/mL)

Quantification of dehydroepiandrosterone in human serum on a routine basis: development and validation of a tandem mass spectrometry method based on a surrogate analyte

In the clinical laboratories dehydroepiandrostenedione (DHEA) is usually quantified by immunoassay based methods, which are often affected by cross-reactivity with endogenous interferences, such as 4-androsten-3β-ol-17-one. The interfering compounds lead to a poor accuracy of the measurements, mainly at a low concentrations level. The present paper describes a validated method based on tandem mass spectrometry coupled to liquid chromatography, for the accurate quantification of DHEA in serum. The peculiarity of this method is the use of calibrators and quality controls prepared by adding measured amounts of DHEA-D5, a stable isotope labeled analogue of DHEA, to real serum from healthy subjects. DHEA-D5 was used in place of DHEA, which is usually present in unstripped serum at physiological levels, as it has the same basic structure, provides an equivalent instrumental response, and can be easily distinguish by DHEA by mass spectrometry due to its different m/z value. The method proved to be sensitive, with a LLOD of 0.09 ng/ml and a LLOQ of 0.23 ng/ml, and selective, with overall performances that allow its use on a routine basis

Plasma N-Acetylaspartate Is Related to Age, Obesity, and Glucose Metabolism: Effects of Antidiabetic Treatment and Bariatric Surgery

Background: N-acetylaspartate (NAA) is synthesized only by neurons and is involved in neuronal metabolism and axonal myelination. NAA is the strongest signal on brain magnetic resonance spectroscopy, and its concentration have been associated with cognitive dysfunction in neurodegenerative diseases, obesity, and type 2 diabetes (T2D). Materials and Methods: We explored the impact of obesity and T2D on circulating NAA as well as the impact of bariatric surgery and antidiabetic treatments. We developed an LC-MS method for the accurate measurements of fasting plasma NAA levels in 505 subjects (156 subjects with normal glucose tolerance, 24 subjects with impaired glucose tolerance, and 325 patients with T2D) to examine the associations of NAA with obesity and dysglycemia. To validate cross-sectional findings, plasma NAA was measured 6 months after Roux-en-Y Gastric Bypass (RYGB) in 55 morbidly obese subjects, and after 1 year of antidiabetic treatment (with dapagliflozin, exenatide, or dapagliflozin plus exenatide) in 192 T2D patients. Results: In the whole population, NAA was associated with age (r = 0.31, p &lt; 0.0001) and BMI (r = −0.20, p &lt; 0.0001). Independently of age and BMI, NAA was reciprocally related to HbA1c and fasting plasma glucose (partial r = −0.13, both p = 0.01). Surgically-induced weight loss raised NAA (by 18 nmol/L on average, p &lt; 0.02). Glucose lowering treatment increased NAA in proportion to the drop in HbA1c (r = 0.31, p &lt; 0.0001) regardless of the agent used. Conclusions: Circulating NAA concentrations are modulated by age, obesity, and glycemic control. Whether they may mark for the corresponding metabolic effects on brain function remains to be established by joint measurements of spectroscopic signal and cognitive function