The study of antibodies and antigens dissociated from the immune complexes extracted from ovarian carcinoma ascitic fluid

In previous studies in our laboratory, heteroantisera were produced in rabbits by immunization with extracts of ascitic fluids from ovarian epithelial carcinomas. Reverse passive hemagglutination (RPHA) assay of these sera was used for the immunodiagnosis of ovarian cancer. Antibodies attached to lysed sheep red blood cells were able to detect tumor antigens in 63% of ovarian carcinoma sera. In the present study we have shown that the antigens detected in these assays are in fact contained in circulating immune complexes and are recoverable by disassociation with 8 M urea and separation of antibody and antigen by ion exchange chromatography. The antibodies thus obtained from immune complexes (IC) were assayed by indirect immunofluorescence against a variety of paraffin-embedded tissue sections. Poorly differentiated ovarian epithelial carcinomas and papillary serous adenocarcinomas, as well as the tumors grown by implantation of the latter in nude mice, were all positively stained, while the Krukenberg tumor metastatic to the ovary, the benign ovarian cyst, the normal ovary, and the normal fallopian tube were all negative. Complete blocking of immunofluorescence staining by prior absorption of antibody with the dissociated antigen was achieved. The present study demonstrates that the antibodies and antigens dissociated from the immune complexes isolated from the ascitic fluids provide useful reagents for immunodiagnosis.

Effect of ascorbic acid on protein synthesis and collagen hydroxylation in continuous flow organ cultures of adult mouse periodontal tissues

A continuous flow organ culture system (CFCS) was used to determine the effect of ascorbic acid on the synthesis of collagen and noncollagenous protein by bone of the alveolar process and periodontal ligament in organ cultures of adult mouse periodontium. For the last 24 h of 2 day cultures, 5 microCi/ml 3H-proline was added to the medium. Highly purified collagenase was used to separate the collagenous and noncollagenous proteins and the incorporation of isotope into each fraction measured. Collage synthesized in the presence of less than 10 micrograms/ml ascorbic acid was found to be highly under-hydroxylated (pro:hypro ap. acts. 2.3-3.1) in both tissues. When the ascorbic acid levels were between 25 and 100 micrograms/ml, the synthesis of collagenous proteins was selectively stimulated and hydroxylation significantly improved (pro:hypro sp. acts 1.72-1.89). The effect of ascorbic acid was not related to tissue viability since tissues cultured initially in the absence of ascorbic acid were able to recover completely when compared to controls given ascorbic acid continuously. The proportion of radioactivity in collagen and noncollagenous protein, collagen hydroxylation, and percentage of collagen synthesized as type III (av.23%) in bone of the alveolar process was similar to that found in vivo. However, in the periodontal ligament in vitro the proportion of noncollagenous protein synthesized was increased from 70% to 87% and the percentage of type III collagen increased from 14% to 26% compared to in vivo results.

Determination of L-ascorbic acid levels in culture medium: concentrations in commercial media and maintenance of levels under conditions of organ culture

The method of Deutsch and Weeks was modified to provide a reliable and reasonably quick method for assaying the L-ascorbic acid content of culture medium. The modified method was used to determine the decay of L-ascorbic acid under various conditions of culture and the concentration of the vitamin in commercially prepared media. The half-life of L-ascorbic acid in a modified New circulator gassed with 95% O2 + 5% CO2 was 1.5 hr.; and when gassed with 20% O2 + 5% CO2 + 75% N2, about 2 hr. In Petri dishes gassed with 20% O2 + 5% CO2 + 75% N2, the half-life of L-ascorbic acid was 0.9 hr. About 4% of the L-ascorbic acid was lost per day when medium was stored at 0 degrees C and about 9% per day when stored at 5 degrees C. When medium with an initial content of 300 microng per ml was stored at room temperature, the half-life was found to be 15.5 hr. The L-ascorbic acid in five commercially available media, which contain the vitamin in their formulations, was assayed immediately after their delivery to the laboratory. The values of L-ascorbic acid measured in these media were in all cases far lower than prescribed. A continuous-flow organ culture system has been designed which allows the provision of a relatively constant level of L-ascorbic acid to explant by taking advantage of the slow oxidation of L-ascorbic acid at 0 degrees C.