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Biomedical subjects

A Vercellone

Publications and source records attributed to A Vercellone.

At least 37 records · Page 2Linked to original sources
PubMed1992

Specific binding of phenolic glycolipid antigens from Mycobacterium bovis BCG with antibodies.

We studied the molecular binding specificity of two rabbit polyclonal sera generated against phenolic glycolipid antigens namely PheG1 B and PheG1 B-3 from Mycobacterium bovis BCG. PheG1 B is the well-known mycoside B (2-O-Me-alpha-L-Rhap 1----aglycone), while PheG1 B-3 is a recently found glycolipid (alpha-L-Rhap-(1----3)-2-O-Me-alpha-L-Rhap 1----aglycone). The interaction specificity was mainly explained in terms of the cavity volume of the antibodies paratope. The anti-PheG1 B antibodies paratope fits the 2-O-Me-alpha-L-Rhap ligand, while that of anti-PheG1 B-3 binds the disaccharide moiety of PheG1 B-3, and, with a higher affinity, the monosaccharidic unit localized at the non-reducing end. The B-3 antigen affinity is higher than that of antigen B for their homologous antibodies. This can be explained by the fact that the antibodies against phenolic glycolipid B-3 bind optimally to two sequential glycosyl residues suggesting the presence of two subsites. The immunoglobulin subsite with the major affinity binds the monosaccharidic unit localized at the non-reducing end.

Animals↗
PubMed1990

Production of cytokines in hemodialysis.

Tumor necrosis factor (TNF-alpha) and interleukin-1 (IL-1 beta) are cytokines primarily produced by monocytes/macrophages when stimulated by endotoxin, complement-derived anaphylatoxins and the specific antigen. In the present study, the plasma levels of TNF-alpha and IL-1 beta were evaluated before and after hemodialysis with cuprophane membrane (in 9 patients) and hemodiafiltration (in 9 patients) using three high-permeability membranes such as polymethylmethacrylate, polyacrylonitrile (AN-69) and polysulfone. In vitro spontaneous production of TNF-alpha and IL-1 beta was evaluated in the supernatants from short-term cultured monocytes obtained before and after treatment. The predialytic levels of TNF-alpha and IL-1 beta were significantly higher (p less than 0.05) in the uremic population than in 21 healthy subjects taken as controls. The analysis of the uremic population regarding the mode of therapy indicated that in hemodialysis the predialytic plasma levels of TNF-alpha and IL-1 beta did not significantly differ from those of healthy subjects. In contrast, in hemodiafiltration with polymethylmethacrylate and AN-69, but not with polysulfone, the predialytic plasma levels of both cytokines were significantly (p less than 0.05) increased. No significant variation in plasma levels of both cytokines was observed after hemodialysis with cuprophane membranes. Hemodiafiltration with polymethylmethacrylate and AN-69, but not with polysulfone, brought about a consistent reduction in plasma levels of both cytokines. Detectable amounts of TNF-alpha and IL-1 beta were spontaneously produced by peripheral-blood monocytes 6 h after the end of hemodialysis but not of hemodiafiltration. These studies suggest a possible role of TNF-alpha and IL-1 beta in the biocompatibility of different extracorporeal treatments.

Acrylic Resins↗
PubMed1990

Comparison between two dialytic populations undergoing renal transplantation.

The outcome of renal transplantation in CAPD patients is still controversial since age and clinical differences often make comparison with hemodialysis patients difficult. The aim of this study was to analyse two homogeneous groups of patients, on CAPD and on hemodialysis. 18 CAPD (Group A) and 18 hemodialysis patients (Group B) were selected for a case-control analysis, matched for age, presence of acute tubular necrosis and Cyclosporine A regimen. Group A and B were not different for male/female ratio, donor age, HLA-Dr mismatches, arterial pressure, cold ischemia, or follow-up. Patient, graft survival and number of rejection episodes did not differ significantly at 1 year; serum creatinine at 6 and 12 months and CyA doses at 1 and 6 months were not different; hospitalization rates for first and subsequent admissions did not differ. Infection-free patients were 9/18 in Group A and 15/18 in Group B, with 12 episodes in Group A and 3 in Group B. Post transplant cholesterol levels showed a trend to increase in both groups and triglycerides levels to a decrease; differences in pre and post transplant in body weight were not significant at 12 months. In conclusion, the outcome of transplantation in CAPD patients is not significantly different from that in hemodialysis patients with similar clinical characteristics.

Adult↗
PubMed1989

New-found phenolic glycolipids in Mycobacterium bovis BCG. Presence of a diglycosylated glycolipid.

A crude phenolic glycolipid extract from Mycobacterium bovis bacille Calmette-Guerin (BCG) was fractionated until homogeneity at the intact level into four phenolic glycolipids called B, B-1, B-2, and B-3 according to their polarity. The apolar one, which is the most abundant was assigned to the well-known mycoside B. The B-2 and B-3 phenolic glycolipids were purified by direct-phase high performance liquid chromatography using a 5 micron Spherisorb column but were only recovered in small amounts (3 mg). A linear gradient of 0-20% methanol in chloroform was used. The B-1, B-2, and B-3 glycolipids were subjected to suitable modern analytical techniques selected for their potential to elucidate the structure at the intact level. Desorption chemical ionization-mass spectrometry allowed the molecular mass of B-3 to be determined as 1652 Da for the major homolog establishing the molecular formula as C103H192O14. Thus, the B-3 polar phenolic glycolipid contained two deoxyhexoses, one molecule of phenolphthiocerol esterified by two molecules of mycocerosic acid. Using two-dimensional 1H NMR (correlated chemical shift and nuclear Overhauser effect spectroscopy) at the intact level the B-3 oligosaccharide structure was determined as an alpha-L-Rhap-(1----3)-2-O-Me-alpha-L-Rhap. This is the first report of a diglycosylated phenolic glycolipid in a nonpathogenic mycobacteria. The disaccharide unit, the antigenic determinant, appears to be characteristic of M. bovis BCG. This polar glycolipid B-3 and the apolar ones, B-1 and B-2, were reactive in enzyme-linked immunosorbent assay against serum from rabbit hyperimmunized with M. bovis BCG.

Carbohydrate Sequence↗
PubMed1989

Ratio between aldosterone and atrial natriuretic peptide in pregnancy.

The possibility of evaluating the ratio between aldosterone and atrial natriuretic peptide (ANP) instead of the two hormones by themselves in studying sodium handling in normal pregnancy and in preeclampsia in the steady state and following albumin infusion was examined in this study. In 32 normal pregnancies monitored monthly, the highest aldosterone/ANP ratio was observed in the last weeks (28.7 +/- 12), and dropped in the first postpartum week (3.6 +/- 2.8), without changes in fractional excretion of sodium. In 18 preeclamptic patients, the ratio was significantly lower than in normal pregnancy at the same gestational ages, and it was coupled with absolute reduction in the sodium excretion. Among preeclamptic patients, a significant inverse correlation (P less than 0.025) was revealed between the ratio and sodium excretion. Natriuresis in response to acute volume expansion with albumin infusion occurred only in 50% of preeclamptic patients, and was associated with an ANP increase, an aldosterone decrease, and a further decrease in the ratio. A blunted natriuresis was observed in cases with a particularly low prealbumin value of this ratio. Furthermore, in preeclampsia, a particularly low ratio seemed to be typical of the patients who showed poorer placental flows and fetal outcomes. These results suggest that the balance between aldosterone and ANP may be a useful index in understanding sodium homeostasis in these settings.

Adult↗