Gianvico Melzi d'Eril

Simultaneous determination of 27 phenols and herbicides in water by high-performance liquid chromatography with multielectrode electrochemical detection

Abstract A sensitive and simple method for the simultaneous evaluation of phenol, 26 substituted phenols and herbicides was developed using HPLC and electrochemical detection. After extraction from the samples on solid-phase cartridges, the compounds were separated on a reversed-phase column by using a combined gradient of organic modifier and counter-ion. The total analysis time was less than 63 minutes. Identification of the compounds was based on retention time comparison with authentic standards. In addition, further confirmation of peak identities and of their purity was determined by comparison of the ratio of the peaks height of each compound across the electrode array, with the similar ratio of the authentic standard. The detection limit was found to be much lower than that indicated by the European Community: for the least sensitive compound (a herbicide, Linuron) it was less than 0.0005 μg/l at signal-to-noise of 3. The method was used to examine the residual levels of phenylurea herbicides, phenol, chloro- and nitro-phenols in tap water, mineral water and spring water from different sources.

Prognostic Role of Clinical and Laboratory Criteria To Identify Early Ventilator-Associated Pneumonia in Brain Injury*

BACKGROUND We investigated the role of the clinical pulmonary infection score (CPIS), serum levels of procalcitonin (PCT), C-reactive protein (CRP), and serum amyloid A (SAA) in the detection of patients with early ventilator-associated pneumonia (VAP). METHODS Observational study in a university hospital. In 58 patients with severe brain injury receiving mechanical ventilation, CPIS, PCT, CRP and SAA were evaluated at ICU entry and at days 3 to 4 of hospital stay for VAP diagnosis (confirmed by endotracheal aspirate or BAL cultures). RESULTS We found the following: (1) PCT at entry was increased in patients who later had early VAP develop (25 patients) compared to no VAP (median, 1.4 ng/mL; 25-75 percentiles, 0.14-0.78; vs median, 0.2 ng/mL; 25-75 percentiles, 0.76-2.4, p<0.001; sensitivity, 76%; and specificity, 75%); (2) CPIS increased at the day of VAP diagnosis, compared to entry (median, 6.6+/-1.1 vs 1.5+/-1.1, p<0.001; sensitivity, 97%; specificity, 100%), while other serum inflammatory markers did not change; and (3) deterioration in oxygenation and changes in tracheal secretions were the main determinants of CPIS changes. CONCLUSIONS PCT may be a useful marker to predict which patients subsequently have early VAP. The CPIS could help as an early way to detect the patients with early VAP and who need further diagnostic testing.

Serum leptin, but not adiponectin and receptor for advanced glycation end products, is able to distinguish autoimmune pancreatitis from both chronic pancreatitis and pancreatic neoplasms

Abstract Objective. Serum leptin and adiponectin determinations have been proposed as markers for distinguishing pancreatic cancer and chronic pancreatitis from autoimmune pancreatitis; however, no studies exist in patients with autoimmune pancreatitis and in those with intraductal papillary mucinous tumors of the pancreas. The aim of this paper was to evaluate the circulating concentrations of receptor for advanced glycation end products (RAGE), leptin and adiponectin in patients with chronic pancreatic diseases. Material and methods. Seventy-five consecutive patients with chronic pancreatic diseases (47 males, 28 females; mean age 67.0 ± 13.2 years; range 37–97 years) were studied: six (8.0%) had autoimmune pancreatitis, 23 (30.7%) had chronic pancreatitis, 34 (45.3%) had pancreatic cancer and the remaining 12 (16.0%) had intraductal papillary mutinous tumors of the pancreas. Leptin, adiponectin and RAGE were determined in serum using commercially available kits. The leptin concentrations were normalized to the lower and upper reference limits because of the different gender reference ranges. Results. Normalized leptin concentrations were significantly lower in chronic pancreatitis patients (0.53 ± 1.28; p = 0.008) and in those with pancreatic cancer (0.12 ± 0.33; p < 0.001) compared to the overall population (0.58 ± 1.23), whereas autoimmune pancreatitis patients had significantly higher concentrations of this protein (2.18 ± 2.56; p = 0.004) compared to the overall population. RAGE and adiponectin concentrations were similar among the four groups of patients studied. Among the clinical variables considered, only pain was significantly related to leptin concentrations (patients with pain 0.18 ± 0.54, patients without pain 1.07 ± 1.64; p = 0.001). Conclusion. Serum leptin seems to be a good serum marker for differentiating autoimmune pancreatitis patients from those with chronic pancreatitis and pancreatic cancer.

Determination of neurochemicals in biological fluids by using an automated high-performance liquid chromatographic system with a coulometric array detector

The chromatographic separation of 33 neurochemicals was achieved by using a combined gradient of organic modifier, pH and counter-ion. A secondary separation of unresolved analytes was obtained by using electrochemical detection with a coulometric array of sixteen electrodes. The stability of the analytes was studied and data on analytical performance are reported in addition to a list of neurochemicals detected in a normal plasma sample.

Fecal calprotectin and elastase 1 determinations in patients with pancreatic diseases: a possible link between pancreatic insufficiency and intestinal inflammation

BackgroundFecal calprotectin determination has been demonstrated to be useful in diagnosing various inflammatory diseases of the gastrointestinal tract; however, data available for patients with pancreatic diseases are scarce. Our aim was to assess fecal calprotectin in order to evaluate the presence of intestinal inflammation in patients with pancreatic disease.MethodsEligible patients with suspected pancreatic illness were enrolled, and in all of them fecal calprotectin and elastase-1, as well as serum amylase and lipase activities, were assayed using commercially available kits.ResultsA total of 90 subjects (47 men, 43 women, mean age 58.6 ± 14.9 years) were enrolled: 20 (22.2%) had chronic pancreatitis; 15 (16.7%) had pancreatic cancer; six (6.7%) had chronic nonpathological pancreatic hyperenzymemia; 16 (17.8%) had nonpancreatic diseases; and 23 (25.6%) had no detectable diseases. Diarrhea was present in 19 patients (21.1%). In univariate analyses, the presence of diarrhea and low fecal elastase-1 concentrations were significantly associated (P = 0.019 and P = 0.002, respectively) with abnormally high fecal calprotectin concentration, and the multivariate analysis demonstrated that low fecal elastase-1 concentration was the only variable independently associated with a high fecal calprotectin concentration.ConclusionsPancreatic insufficiency may cause intestinal inflammation, probably because of a modification of the intestinal ecology.

Serum adhesion molecules in acute pancreatitis: Time course and early assessment of disease severity

Objectives: To evaluate the adhesion molecule time course in the early phases of acute pancreatitis and to explore the usefulness of these proteins in assessing the severity of the disease. Fifteen consecutive acute pancreatitis patients (10 patients with the mild and 5 with the severe disease) admitted to the hospital within 6 hours after the onset of pain and 15 age- and sex-matched healthy subjects. Methods: Vascular cell adhesion molecule 1, intercellular adhesion molecule 1, E-selectin, P-selectin, and L-selectin were quantified on hospital admission and for the following 2 days. Results: Acute pancreatitis patients had vascular cell adhesion molecule 1 and P-selectin concentrations significantly lower and L-selectin concentrations significantly higher than the healthy subjects. Only E-selectin was significantly higher in severe than in mild disease (P = 0.029); a value of E-selectin ranging from 3.83 to 3.92 ng/mL was the best cutoff value for differentiating severe from mild acute pancreatitis (sensitivity: 60.0%, specificity: 90.0%, cases correctly classified: 80%). E-selectin and P-selectin entered the multivariate logistic regression analysis, and a score was calculated showing a sensitivity of 93.3% and a specificity of 86.7% in identifying the patients with severe pancreatitis. Conclusions: This score seems to be useful for the early assessment of the severity of acute pancreatitis.Abbreviations: VCAM-1 - vascular cell adhesion molecule 1, ICAM-1 - intercellular adhesion molecule 1

Determination of amines in wines by high-performance liquid chromatography with electrochemical coulometric detection after precolumn derivatization

Abstract A sensitive and simple method for the simultaneous evaluation of histamine, tryptamine, tyramine, phenylethylamine, putrescine, cadaverine, 1,6-diaminohexane and tryptophan in wine was developed using HPLC and coulometric detection without clean-up pretreatment. After precolumn derivatization with o-phthaldialdehyde the compounds were separated on a reversed-phase column with gradient elution. To increase the selectivity of the method a coulometric array of sixteen electrodes at increasing potentials was used. The total analysis time was less than 35 min. The analytical performance of the methods is reported. The method was used to examine the levels of various amines in three different wines.

Concentrations of L-dopa in plasma and plasma ultrafiltrates.

A sensitive and specific procedure is described for the determination of therapeutically relevant concentrations of L-dopa in plasma and plasma ultrafiltrates (free fraction) by high performance liquid chromatography with electrochemical detection. In plasma samples from healthy adult subjects (n = 15) spiked with L-dopa (500 micrograms l-1) the free fraction averaged 76 +/- = 8% (range 61-84%). Free fraction values increased by 38% with increasing plasma concentrations of L-dopa from 100-5000 micrograms 1-1. L-dopa free fraction was not affect by the presence of 3-O-methyl-dopa at concentrations up to 10,000 micrograms l-1.

HLA complement gene polymorphisms in multiple sclerosis - A study on 80 Italian patients

We studied C4A, C4B, and Bf complement gene polymorphisms in 80 Italian patients with multiple sclerosis (MS). We observed a significantly higher frequency of C4AQ0 allele in patients with the relapsing-remitting form of MS than in ethnically homogeneous controls. Restriction fragment length polymorphism analysis by Southern blotting of the C4/CYP21 gene complex showed that a structural gene deletion was present in 45% of patients with the C4AQ0 allele. Our data support the hypothesis that relapsing-remitting MS and primarily chronic progressive MS are immunogenetically distinct diseases; further, complement factor abnormalities typical of autoimmune diseases could influence the pathogenesis of MS.

Plasma concentrations of angiogenetic factors and angiogenetic inhibitors in patients with ductal pancreatic neoplasms. A pilot study

Abstract Background: The aim of the study was to evaluate the circulating concentrations of vascular endothelial growth factor (VEGF), vascular endothelial growth factor receptor-2 (VEGFR-2), vascular endothelial growth factor-D (VEGF-D) and endostatin in patients with intraductal papillary mucinous neoplasm (IPMN), and in those with ductal adenocarcinomas. Methods: Sixty patients (32 males, 28 females, mean age 69.3±11.3 years) were enrolled: 31 (51.7%) had IPMNs and 29 (48.3%) had histologically confirmed pancreatic adenocarcinomas. Thirty blood donors were also studied as controls. In all study subjects, the concentrations of VEGF, VEGF-D, VEGFR-2, and endostatin were determined using enzyme-linked immunosorbent assays. Results: Serum concentrations of VEGF, VEGF-D, and VEGFR-2 were significantly higher in patients with pancreatic ductal adenocarcinoma and those with IPMNs compared with healthy subjects, while endostatin was significantly higher only in patients with pancreatic ductal adenocarcinoma compared with healthy subjects. Within the group of patients, VEGFR-2 was significantly higher in patients with ductal adenocarcinoma compared to those with IPMNs. The sensitivity and the specificity of VEGFR-2 in differentiating patients with ductal adenocarcinomas from those with IPMN at a cut-off range of 4003–4034 pg/mL was 86.2% and 54.8%, respectively. Conclusions: IPMNs have serum VEGFR-2 concentra-tions different from those in patients with ductal adenocarcinomas. However, serum VEGFR-2 cannot be routinely utilized to differentiate IPMNs from pancreatic ductal adenocarcinomas.