Search PubMed⌕ Search

Biomedical subjects

R Moratti

Publications and source records attributed to R Moratti.

At least 19 recordsLinked to original sources
PubMed2003

Utility of biochemical markers in the follow-up of heart transplant recipients.

Endomyocardial biopsy (EMB) is currently the standard method to diagnose acute graft rejection. However, considering the potential complications of this procedure, a noninvasive marker of rejection would be an ideal alternative or at least a helpful adjunct to posttransplant management. We measured myoglobin (Myo), creatine kinase MB mass (CK-MBm), troponin T (cTnT), serum amyloid A (SAA), and C-reactive protein (CRP) in 57 patients (mean age 37.5 years) who underwent orthotopic heart transplantation for end-stage cardiac failure between January and December 2001.Endomyocardial biopsies were performed routinely after surgery and histologically diagnosed rejection was graded according to the criteria of the International Society of Heart and Lung Transplantation. Concomittant with the biopsies, blood samples were drawn from the coronary sinus (central blood samples) and from a peripheral vein (peripheral blood samples) to assay biochemical markers. Among 149 EMB evaluated, 87 were negative (grade 0); 28 showed grade 1a rejection; 26 showed grade 1b; and 8 showed grade > 1b (2 were grade 2, 6 were grade 3a). Grades 0 and 1a were considered to be negative, while grades 1b and >1b were considered positive indicating potential acute graft rejection. cTnT, Myo, CK-MBm, SAA, and CRP levels were measured in 149 central blood samples and 149 peripheral blood samples. Myo and CK-MBm did not show significant changes. cTnT seems to be a potentially useful addition to the EMB results, while SAA and CRP showed variations with respect to EMB grade both in central and peripheral samples.

Adult↗
PubMed2003

Recombinant birch allergens (Bet v 1 and Bet v 2) and the oral allergy syndrome in patients allergic to birch pollen.

BACKGROUND: IgE cross-reactivity between pollen and food allergens represents the molecular basis for oral allergy syndrome (OAS). OBJECTIVE: To evaluate specific IgE for Bet v 1 and Bet v 2 in the serum of patients sensitized to birch pollen and to identify whether IgE antibodies to Bet v 1 and Bet v 2 were predictors of OAS. METHODS: Thirty-three patients with skin prick test results and radioallergosorbent assay test results positive to birch pollen, 12 (36%) of whom had OAS symptoms, were enrolled in the study. Serum levels of specific IgE were determined by the fluoroenzyme immunoassay technique. RESULTS: The t test revealed significantly higher serum IgE levels against Bet v 1, Bet v 2, and birch pollen in the 12 symptomatic patients with respect to those without OAS (32.4 vs 12.4 kU/L, 7.6 vs 1.3 kU/L, and 42.3 vs 17.3 kU/L, respectively). Attempts to establish a threshold value of serum IgE antibirch pollen and the appearance of OAS revealed that a level of 20 kU/L or more yields an efficiency of the test equal to 70%. CONCLUSIONS: In our study, quantitative birch specific IgE level proved useful in predicting clinical allergy symptoms with birch exposure.

Adult↗
PubMed2002

Oxidation of low-density lipoprotein in atherosclerosis from basic biochemistry to clinical studies.

Although it has been known for long time that atherosclerosis is associated with lipid deposition, only recently it has been accepted that the plasmatic concentration of cholesterol, especially LDL cholesterol, is a risk factor for atherosclerosis. However, chemically modified LDL, but not native LDL, is able to induce the formation of foam cells, the hallmark of atherosclerosis. LDL oxidation is likely to be the most important form of LDL modification in humans. In biochemical terms, LDL oxidation is a free radical driven chain reaction where polyunsaturated fatty acids are converted to lipid peroxides, which easily decompose to many products, including biologically active aldehydes. The assay of LDL oxidation in biological fluids is problematic; direct assays detect a product of LDL oxidation whereas indirect assays give an indicator of LDL oxidation susceptibility. In general, epidemiological studies support the concept that the level of plasmatic lipophilic antioxidants, tocopherols and carotenoids, is low in populations at increased risk for atherosclerosis. However, clinical trials based on vitamin E as antioxidant showed inconclusive results, suggesting that supplementation with vitamin E is not generically recommended for atherosclerotic patients. These results, however, do not contradict that oxidation of lipoprotein is involved in atherosclerosis; rather, this negative outcome raises a number of considerations such as the need for a reliable marker of lipoprotein oxidation in plasma and a more complete information about the physiological triggers of lipoprotein oxidation.

Animals↗
PubMed2001

CD23 during SIT.

Explore the source record for details and available documents.

Desensitization, Immunologic↗
PubMed2001

The Pavia approach to clinical protein analysis.

The protein chemistry laboratory of the Pavia University Hospital is specialized in the study of monoclonal components in body fluids. It is closely connected with the research laboratory devoted to the structural and functional study of pathogenic proteins and with the Clinical Chemistry Central Laboratory. The analyses are performed on specific medical request. The analytical approach is mainly based on analysis of patient's serum and urine by high-resolution agarose gel electrophoresis and immunofixation with the possible addition of the quantification of specific proteins. The interpretation of the protein pattern and the final reporting result from the integration of the laboratory data with the clinical information. This labor-intensive approach requires skills in the performance of protein analysis and in the interpretation/referral phase, as well as close communication with the attending physician.

Clinical Chemistry Tests↗
PubMed2000

Considerable lack of agreement between S-FPIA and EMIT cyclosporine assay in therapeutic drug monitoring, of heart transplant recipients.

The authors performed a comparative analysis of 60 whole blood samples containing cyclosporine (CsA) from heart transplant (HTx) recipients (n = 60) by the two "specific" monoclonal immunoassays, enzyme-multiplied immunoassay technique (EMIT) and fluorescence polarization immunoassay (S-FPIA), using the Altman-Bland approach based on graphical techniques and simple calculations. The CsA blood concentrations measured by S-FPIA [mean (SD): 268.1 (108.8) ng/mL] showed a statistically significant difference (P < 0.001) from the corresponding concentrations measured by EMIT [219.6 (118.7) ng/mL]. The CsA concentrations were 27% (median) higher when determined by monoclonal S-FPIA than by EMIT. The comparison between EMIT and S-FPIA showed a good correlation (S-FPIA conc. (ng/mL) = EMIT conc. (ng/mL) x 0.88 + 76.1, r = 0.96, P < 0.001). However, a high correlation does not mean that the two methods agree, and their use as interchangeable might be misleading. The authors summarized the degree of agreement by calculating the bias estimated by the mean difference (d) and the standard deviation of the difference (SD). For CsA concentration data, the mean difference (S-FPIA minus EMIT) is +49.9 ng/mL and SD is 31.2 ng/mL. Altman-Bland analysis indicates considerable lack of agreement between EMIT and S-FPIA, with discrepancies of more than 100 ng/mL. The present study's data clearly show that there is a considerable and clinically unacceptable lack of agreement between the S-FPIA and the EMIT techniques in HTx recipients for the whole range of concentrations evaluated (25-500 ng/mL), and this is caused by the variation in the overestimation of the CsA parent compound. Even though a similar CsA reference range was reported during maintenance therapy for both methods (150-250 ng/mL), which might encourage their interchangeability in the clinical setting, this approach should be avoided. Laboratory reports should always state both the concentration of CsA and the analytical method.

Adult↗
PubMed1999

Chondroitin-4-sulfate protects high-density lipoprotein against copper-dependent oxidation.

We investigated the effect of chondroitinsulphate (CS), the major glycosaminoglycan of the arterial wall, on the oxidation of human high-density lipoprotein (HDL) by kinetic analysis. Chondroitin-4-sulfate (C4S) increased the lag time and reduced the maximum rate of HDL oxidation induced by Cu2+, as assessed by monitoring both conjugated diene formation and low-level chemiluminescence. On the contrary, chondroitin-6-sulfate (C6S) was ineffective. Dermatansulfate exhibited an inhibitory effect comparable to that of C4S. C4S protected also the protein moiety of HDL, as it reduced tryptophan destruction by lipid-oxidizing species and delayed the formation of fluorescent adducts between end products of lipid peroxidation and amino acid residues. Again, C6S was ineffective. C4S was able to bind Cu2+; this resulted in less Cu2+ available for HDL oxidation and likely represented the mechanism of the protective effect. Neither C4S nor C6S affected HDL oxidation by peroxyl radicals, indicating that free radical scavenging activity was not involved in the protective effect. These results suggest that C4S might prevent the oxidative modification of HDL in arterial wall, thus preserving its antiatherogenic potential for reverse cholesterol transport and, possibly, for clearance of oxidized lipids.

Adult↗
PubMed1999

Fetal erythroblast isolation up to purity from cord blood and their culture in vitro.

BACKGROUND: Erythroblasts have been the most encouraging candidate cell type for noninvasive prenatal genetic investigation. We previously showed that human erythroblasts can be recovered from bone marrow and blood bank buffy coats by a physical cell separation. In the present study, we modified our previous methodology, taking into account the peculiar behavior of erythroblasts in response to modifications of pH and osmolality of the separation medium. METHODS: Twenty to forty milliters of cord blood were initially centrifuged on Ficoll/diatrizoate (1.085 g/ml). The interphase cells were further separated on a continuous density gradient (1.040-1.085 g/ml). Two different gradients were initially compared: the first was iso-osmolar and neutral, whereas the second also contained an ionic strength gradient and a pH gradient (triple gradient). A subsequent monocyte depletion was performed by using magnetic microbeads coated with anti-CD14 monoclonal antibody (mAb), and erythroblasts were purified by sedimentation velocity. Purified cells were investigated by analyses with fluorescence-activated cell sorting (FACS) and fluorescence in situ hybridization (FISH) and immunocytochemistry with mAb against fetal hemoglobin and were cultured in vitro. RESULTS: When nucleated cells were spun on an iso-osmolar and neutral continuous density gradient, two separated bands of nucleated red blood cells (NRBCs) were obtained: a light fraction banding at 1.062 g/ml and an heavy fraction banding at 1.078 g/ml. Conversely, when cells were spun in the triple gradient, NRBCs were shifted to the low-density region. Monocyte depletion by immunomagnetic microbeads and velocity sedimentation provided a pure erythroblast population. FACS and FISH analyses and immunocytochemistry substantiated the purity of the isolated cell fraction, which was successfully cultured in vitro. CONCLUSIONS: We have shown that fetal erythroblasts can be purified up to homogeneity from cord blood, but further refinements of the isolation procedure are necessary before the same results can be obtained from maternal peripheral blood.

Blood Sedimentation↗
PubMed1999

Assessment of renal function in patients with multiple myeloma: the role of urinary proteins.

Renal failure (RF) in multiple myeloma (MM) is considered an ominous complication even though, when timely therapy is started in patients with minimal damage, a high percentage of cases can achieve a regression. The evaluation of renal involvement usually relies on serum creatinine or its clearance, but these parameters have proved to be inadequate to identify initial damage. The aim of this study was to assess the role of the following urinary proteins in diagnosing renal impairment at an early stage: high-molecular-mass proteins (transferrin, IgG, albumin) as markers of glomerular damage, and low-molecular-weight proteins and parenchymal enzymes [alpha(1)-acid glycoprotein (AGP), alpha(1)-microglobulin (alpha(1)M), retinol-binding protein (RBP), beta(2)-microglobulin (beta(2)M), lysozyme (LZ), and N-acetyl-beta-d-glucosaminidase (NAG)] as indicators of tubular disorder. Thirty MM patients (nine at disease onset and 21 previously treated) were included in the study. No correlation was found between the urinary proteins and the phase or the stage of the disease. By the Spearman test, Bence Jones proteinuria correlated significantly with the 24 h proteinuria (p=0. 01) and beta(2)M (p=0.02), and weakly with the alpha(1)M. Serum creatinine concentrations and urea correlated with most of the analytes evaluated: RBP correlated well with urea (p=0.004) and creatinine (p=0.004); IgG (p=0.006) albumin (p=0.009), AGP (p=0.04), and NAG (p=0.02) correlated with serum creatinine. Significant statistical correlation was found between all the analytes except LZ and the creatinine clearance. Twelve of the 30 MM patients (40%) showed abnormal values of urinary proteins. Four of these patients showed overt renal failure with significant modification of the serum parameters and of creatinine clearance, three showed an isolated decrease of creatinine clearance, and five did not present any alteration of serum or urinary parameters. This testifies to the utility of urinary proteins in highlighting renal damage even in cases where the customary serum indicators of renal disorder are normal. In conclusion, our results demonstrate that AGP, RBP, NAG, transferrin, and IgG are good indicators of renal damage. They do not correlate with the severity of the disease, but they seem to be helpful in identifying a subset of patients with initial renal dysfunction.

Adult↗
PubMed1998

Study of factors affecting the determination of total plasma 7-fluorobenzo-2-oxa-1,3-diazole-4-sulfonate (SBD)-thiol derivatives by liquid chromatography.

A detailed investigation of the factors affecting the determination of total plasma 7-fluorobenzo-2-oxa-1,3-diazole-4-sulfonate (SBD)-thiol derivatives (i.e. cysteine, homocysteine and cysteinylglycine) is described. Essentially, this assay entails extracting specific thiols by plasma disulphide bond reduction, protein precipitation, sulphydryl compound derivatization with the thiol-specific fluorogenic reagent ammonium 7-fluorobenzo-2-oxa-1,3-diazole-4-sulphonate (SBD-F), and subsequent separation with isocratic reversed-phase high-performance liquid chromatography. By improving the reliability of several analytical parameters (composition of the mobile phase, pretreatment of the sample using different reducing and protein precipitation agents, and optimization of the derivatization of thiols with SBD-F), a number of critical issues can be identified and solved.

Adult↗
PubMed1998

Nitrite/nitrate balance during photoinduced cerebral ischemia in the rat determined by high-performance liquid chromatography with UV and electrochemical detection.

A specific and simple method for the direct simultaneous detection of extracellular nitrite (NO2-) and nitrate (NO3-) has been developed, using high-performance liquid chromatography separation with UV and electrochemical detection in series. These stable endproducts of nitric oxide (NO.) were determined in dialysis perfusate obtained through in vivo brain microdialysis during and after experimental photoinduced cerebral ischemia in rats. The chromatographic conditions were optimized with a reversed-phase column (250 x 46 mm) using 10 mM n-octylamine pH 6.0 as a mobile phase. Absorbance was measured at 220 nm for NO3- detection; electrochemical detection was performed at +0.7 V for NO2- evaluation. This assay system holds the advantages of in vivo consecutive measurements, high precision, good reproducibility, technical simplicity, fast response (about 7 min), and wide availability.

Animals↗
PubMed1997

Hyperamylasemia due to macroamylasemia in adult gluten enteropathy.

We report hyperamylasemia due to macroamylasemia in a 33-year-old-woman with gluten enteropathy. Macroamylasemia was demonstrated by precipitation of 97% of amylase activity with PEG 6000. It was associated with increased serum IgA, with elevated values of specific IgA antibodies against alpha-gliadin and with a high titre of IgA anti-endomysium antibodies. Macroamylasemia disappeared after 2 months of a strict gluten-free diet. These data suggest that the increased IgA concentration in adult gluten enteropathy led to increased macroamylase formation.

Adult↗
PubMed1996

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.

Adult↗