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Biomedical subjects

V Cavalca

Publications and source records attributed to V Cavalca.

11 recordsLinked to original sources

Hyperhomocysteinemia in myelodysplastic syndromes: specific association with autoimmunity and cardiovascular disease.

Hyperhomocysteinemia (HH) has been associated with cardiovascular and autoimmune diseases and oxidative cell damage. Myelodysplastic syndromes (MDS) are associated with autoimmunity (AI) and increased oxidative stress. We tested the association of HH and oxidative stress in 33 MDS patients, by measuring plasma homocysteine and malondialdehyde (MDA). HH was found in 42% of cases, (4/5) cases with associated cardiovascular events (CVE)(80%), and 9/15 cases with associated AI (60%). Thus in MDS, HH was significantly associated with AI/CVE (chi(2) : p=0.0011), and this association seems to be specific, as demonstrated by the comparison of MDS presenting AI/CVE with the ischemic cardiopathy/rheumatoid arthritis control group (13/20, 65% vs 19/69, 27%; chi(2) : p=0.0021). The levels of MDA indicated increased oxidative stress. Our data may suggest that in a subset of MDS, HH may simultaneously contribute to bone marrow myelodysplasia, CVE and AI pathogenesis, possibly through oxidative cell damage.

Analysis of Variance↗

Oxidative stress and homocysteine in coronary artery disease.

BACKGROUND: Oxidative stress is present in cardiovascular diseases (CVDs), and hyperhomocysteinemia, an independent risk factor for these diseases, may play a role by inducing production of oxygen free radicals. METHODS: To evaluate the possible role of homocysteine (Hcy) in inducing oxidative stress in coronary artery disease (CAD), plasma Hcy was measured in 68 consecutive cardiovascular patients, and plasma malondialdehyde (MDA), both free and total (free + bound), was measured in 40 patients with CAD (18 with chronic stable angina and 22 with unstable angina). As controls, we tested 70 healthy volunteers. Hcy was measured by an immunoenzymatic method and MDA, an index of lipid peroxidation, by gas chromatography-mass spectrometry. RESULTS: Plasma Hcy concentrations were significantly higher in cardiovascular patients than in controls (10.2 vs 8.9 micromol/L; P <0.0002), with no significant difference between values in the stable and unstable angina subgroups. Similarly, total MDA was significantly higher in the CAD group than in the controls (2.6 vs 1.3 micromol/L; P <0.00001), again with no significant difference between stable and unstable angina patients. By contrast, free MDA, which was significantly higher in the CAD patients than the controls (0.4 vs 0.2 micromol/L; P < 0.00001), was also significantly higher in the unstable than in the stable angina group (0.5 vs 0.3 micromol/L; P <0.03). However, no correlation was observed among Hcy and free and total MDA. CONCLUSIONS: Our findings show that a moderate increase of Hcy is associated with CVD but that Hcy at the detected values cannot be considered completely responsible for oxidative damage. That lipid peroxidation is involved in CAD is shown by our observation of significantly increased plasma free and total MDA concentrations compared with controls. Moreover, free MDA values discriminated between unstable and chronic stable angina, and could thus represent a new diagnostic tool.

Angina Pectoris↗

Whole blood folate concentrations: comparison between Stratus Folate (DADE) and radioassay (DPC) methods.

The analytical performance of the Stratus Folate assay for intra-erythrocyte folate determination in normal subjects and in patients affected by folate-related diseases was compared with that of the radioassay (DPC) routinely employed by us. Folate concentrations were measured in freshly obtained EDTA whole blood from 100 subjects. Haemolysis was performed with the appropriate lysis reagent. In addition, to compare two different haemolysis procedures folate determination was carried out in 51 samples haemolysed according to the two procedures in parallel. Data were analyzed using Wilcoxon's test and standardized principal component analysis. Stratus Folate assay and radioassay performances were comparable in terms of analytical characteristics as well as in individual intraerythrocyte folate values across the range of whole blood concentrations examined in the survey. Significant differences were detected between the two different haemolysis procedures only for the radioassay. In conclusion, we observed no significant differences between the two folate determination methods despite their different analytical principles, which indicates the suitability of routine use of the automated non-isotopic Stratus Folate assay for clinical purposes. Moreover, with the latter assay the laboratory staff could choose the more convenient haemolysis procedure.

Automation↗

Two CEA cross-reacting antigens: differences in absorbing the same anti-CEA serum.

A factor that cross reacts with the carcinoembryonic antigen (CEA), which we call P factor, was isolated from normal human plasma. To demonstrate the difference between this P factor and the nonspecific cross-reacting antigen (NCA), the same anti-CEA serum was absorbed in an identical manner with both the antigens. Absorption was checked by immunohistochemistry by the beta-galactosidase procedure on sections of colonic adenocarcinoma and normal colonic mucosa. The unabsorbed antiserum recognizes both tissues; after absorption with NCA the staining becomes paler on both tissues, but maintains color on the normal colonic mucosa and granulocytes. Only absorption with the P factor will give an unstained field of normal colonic mucosa, thus revealing the tumor structure. Data obtained by us suggest that the NCA (tissue extract) is an antigen that is not suitable to the absorption of anti-CEA serum for immunocytochemistry techniques, whereas the P factor (plasma extract) appears to be utilizable with good results.

Absorption↗

Anti-carcinoembryonic antigen sera acquiring higher tumor specificity by absorption with a plasma factor.

A factor reacting with antisera against carcinoembryonic antigen (CEA) was isolated from healthy donors' plasma. Ten different antiCEA sera were absorbed with this plasma factor (P-factor): the antiCEA activity was mostly, or completely, removed in 8 sera. Only 2 of these absorbed sera (here defined as type A) still presented a high CEA binding activity by radioimmunoassay and, on tissue sections, selectively stained most of the colonic adenocarcinomas and areas of severe dysplasia in neoplastic adenomas. Contrary to the behaviour of the antisera against the P-factor, of the unabsorbed antiCEA sera, of a commercially available antiserum and of a monoclonal antibody, the P-absorbed type A antiCEA sera appeared unreactive with normal colonic mucosa and granulocytes. Absorption with the P-factor allows us to obtain antiCEA sera with higher tumor specificity.

Adenocarcinoma↗

BCA (breast cancer antigens): different purification extraction methods.

Various types of extraction were tested to increase the immunological yield of BCA, a CEA-like primary breast cancer associated carcinoma antigen. To allow a comparison, the different extraction techniques were applied to only one breast tumour. The comparison of the various systems was based on two parameters: protein yield and immunological activity, assayed in a RIA 125I CEA-anti CEA system. The following extraction methods were described and compared in this paper: 3M KCl; 1N HClO4; neutral pH extraction (PBS) in the absence and presence of various detergents (anionic, neutral and cationic), basic pH extraction (1N NaOH) and acid pH extraction (1.5M acetic acid) in the presence of urea and various detergents. The more significant systems were applied also to the extraction of CEA, from colonic adenocarcinoma liver metastases. The best results for both the antigens studied were obtained by using neutral detergents (1% NP 40) at neutral pH.

Antigens, Neoplasm↗

Extraction and partial purification of a CEA-like BCA from a pool of pre-selected breast carcinomas.

By exploiting the cross-reaction among the antigens associated with a pool of breast carcinomas, preselected according to their antigenic content, a CEA-like BCA, with a specific activity of 1400 U/micrograms has been extracted, by means of 3M KCl, and partially purified by means of ConA Sepharose affinity chromatography and bioabsorption, employing, for the latter, a cross-reacting antiserum (anti CEA). The subsequent labelling, after Sephadex G-200 gel filtration, points out an immunological activity at the apex of the first peak versus anti CBC (or C.BCA) and anti CEA.

Absorption↗

Age- and gender-related oxidative status determined in healthy subjects by means of OXY-SCORE, a potential new comprehensive index.

Oxidative stress has been related to various diseases, gender and ageing, and has been measured by various markers. The authors developed a procedure to compute a global oxidative stress index (OXY-SCORE), reflecting both oxidative and antioxidant markers in healthy subjects. Its performance was tested in relation to age and gender and in coronary artery disease (CAD) patients. Eighty-two healthy subjects and 20 CAD patients were enrolled. Plasma free and total malondialdehyde (F- and T-MDA), glutathione disulphide/reduced form ratio (GSSG/GSH) and urine isoprostanes (iPF2alpha-III) levels were combined as oxidative damage markers (damage score). GSH, alpha- and gamma-tocopherol (TH) levels, and individual antioxidant capacity were combined as antioxidant defence indexes (protection score). The OXY-SCORE was computed by subtracting the protection score from the damage score. Among single parameters, T-MDA and iPF2alpha-III significantly correlated with age; only GSH and both tocopherols correlated with male gender in healthy subjects. The OXY-SCORE was positively associated with age (p=0.004) and male gender (p=0.03). As expected, the OXY-SCORE was higher in CAD with a very significant p-value (<0.0001), after adjusting for age, gender and smoking. Combining different markers can potentially provide a powerful index in the evaluation of oxidative stress related to age, gender and CAD status.

Adult↗