Search

The system Ga0.5V2S4–Ga0.5V2Se4has been investigated by powder X-ray diffraction methods. A complete series of mixed crystals with a spinel structure with 1:1 ordering on the tetrahedral sites (space group F4̄3m) is formed. The lattice parameters of the cubic cell of the mixed crystals are linearly dependent on the S:Se ratio. The structures of the two border and one intermediate compound have been solved by the Rietveld method. Fractional parameters and interatomic distances are given for the different compositions. In the structure, the vanadium atoms are shifted from their ideal position to form isolated tetrahedral clusters with relatively short vanadium–vanadium distances of 288–296 pm.

We determined the concentration and effusion/serum ratio of mucin-like carcinoma-associated antigen (MCA) in comparison to carcinoembryonic antigen, carbohydrate antigen 19-9, cancer antigen 125, and cancer antigen 15-3 in 80 sera and 99 effusions from 64 patients with histologically confirmed malignancies (4 patients out of this group showed various effusions simultaneously, which were analyzed separately) and 31 patients with various nonneoplastic diseases. Tumor cells were detected by cytological examination in 41 effusions (60.3%) from patients with neoplastic diseases, while in another 27 cases this method failed to demonstrate the malignant origin of the effusion. Of the cytological “positive” malignant effusions 90% were also correctly identified by an elevated MCA concentration at a cutoff level of 10 U/ml, whereas only one effusion of benign origin (3%) showed a slightly elevated MCA concentration of 10.5 U/ml. In 33% of cytologically “negative” effusions of patients with neoplastic diseases, the MCA concentration was also elevated, with a maximum of 453 U/ml. Increased MCA levels in cytologically confirmed malignant effusions were not restricted to metastatic breast cancer. All 17 cytologically “positive” “non-breast cancer” effusions were correctly identified by their MCA concentrations. None of the other tumor markers reached this high sensitivity at the same level of specificity. The ratio of effusion/serum concentration of all tumor markers as well as the concentration of cancer antigen 125 in effusions was of little diagnostic value. Our results indicate that the MCA concentration in an effusion correlates very closely with its malignant origin and is superior to all the other antigens tested. Accordingly, the concurrent MCA determination could improve the diagnostic accuracy of the cytological examination of effusions.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.