14 patients with hepatocellular carcinoma and one with a hepatoblastoma were given AFP antibodies and changes in serum AFP levels and clinical courses were observed. Anti-human AFP horse IgG was purified by immunoadsorbent column chromatography. 1 mg of the purified antibody was able to bind 100-150 micrograms of AFP. 200-800 mg were given to each patient, according to their AFP levels. Also, conventional anti-cancer agents were administered consecutively. In all cases, the serum AFP levels measured by RIA decreased rapidly to undetectable levels within 24-48 h after the infusion. Then, in seven of 15 cases, the relatively low level was maintained for periods of 10-96 weeks. In the remaining eight cases, the serum AFP level increased again after 1-2 weeks and rose further with clinical deterioration. Since the antibody administered was undetectable in the serum within 2 weeks after its infusion, it is suggested that the AFP antibody had an inhibitory effect on the production or the release of AFP in some patients.
Mouse fetal liver cells cultured on a pigskin epidermal substrate grew for 7 weeks. Different enzymes and proteins, i.e. gamma-glutamyl transferase (GGT), nonspecific esterase (NE), lactic dehydrogenase (LDH), alpha-fetoprotein (AFP), and albumin were studied histochemically and/or biochemically. The activity of GGT was high at the beginning of culture and then decreased rapidly. The activities of NE and LDH were high during the culture. Release into the media and localization of AFP suggested active synthesis during the early stages. AFP levels gradually decreased and could be demonstrated only in trace amounts after 3-4 weeks of culture. On the other hand, the production of albumin was weakly evident early and became more and more evident after the second week in culture. Hydrocortisone modulated AFP and albumin production. The effect of hydrocortisone was to prolong expression of AFP and to reduce expression of albumin. Electron microscopic observations showed that the cultures consisted of organelle-rich parenchymal cells associated with the pigskin basement membrane by pseudopod-like structures. These results indicate that fetal mouse parenchymal cells were cultured and modulated on a pigskin epidermal substrate.
Tissue samples from 125 cases of a variety of human malignancies and benign conditions were examined for the presence of histaminase by the immunoperoxidase method on conventional pathological specimens. Histaminase was found diffusely in the cytoplasm of cancer cells of primary and metastatic tumors of lung, thyroid gland, pancreas, stomach, esophagus, ovary and pharynx. Histaminase-positive cases were also found in carcinoids, dysgerminomas and in melanoma. The incidence of positive histaminase staining in epithelial malignancies overall was 28/84, and those in sarcoma as well as in benign conditions were 1/22 and 0/19, respectively, excluding placental decidual cells and eosinophils intermingled in the tissues. No significant difference in the incidence of histaminase was found by histological type or by degree of cellular differentiation. The present results thus provided another direct evidence for the production of histaminase by many kinds of tumor cells.
Radioimmunoassays specific for fructose-1, 6-diphosphate aldolase isozymes were developed for the quantification of human aldolase A, B and C. The method is a double-antibody radioimmunoassay using radioiodinated purified aldolase A, B and C as ligand, chicken antibodies to aldolase A, B and C, and rabbit antibodies to chicken IgG. The Iodogen method was used for the iodination of aldolase A, B and C in this study. Aldolase A was predominantly high in concentration in muscle, aldolase B was high in normal adult liver, and aldolase C was high in adult brain. Aldolase A was elevated in hepatoma tissue and hepatoma cell lines, where aldolase B was distinctly low. Normal serum levels for the three isozymes were determined. The aldolase A levels in serum obtained from 41 normal subjects were 170 +/- 39 ng/ml. Serum aldolase A levels were increased in many patients with cancer and muscle diseases, but were not increased in patients with hepatitis or other benign diseases. Serum aldolase B levels obtained from 11 normal subjects were 28.5 +/- 9.2 ng/ml. Serum aldolase B levels were increased in patients with hepatitis and correlated well with serum GPT levels. Serum aldolase C levels obtained from 12 normal subjects were 2.4 +/- 0.7 ng/ml. The determination of aldolase A, B and C by radioimmunoassay may be a valuable tool in biochemical and clinical studies of aldolase isozymes.
Serial maternal serum hemoglobin F (HbF) levels were measured by radioimmunoassay in 23 normal pregnancies. The maternal HbF fraction remains within the normal range during the first trimester (mean + 2 S.D. = 0.15 + 0.13). After 15 weeks gestation, maternal HbF levels rise in some, but not all, pregnancies. In about 30% of the cases the HbF fraction remains within the range seen in adult men and non-pregnant women. Irregular rises in HbF were found in other pregnancies studied serially. The maternal HbF fraction may be an indicator of transplacental hemorrhage.
The effects of estrogen, antiestrogen and ovariectomy on the growth of a mouse teratocarcinoma, OTT6050, were studied in vivo. Subcutaneous tumors transplanted in syngeneic 129/Sv male and female mice were measured, and tumor-growth curves were constructed using the products of three principal tumor diameters, designated tumor volume. There was a linear correlation between the measured tumor volume and the actual excised tumor volume. The tumor growth rate in estrogen-treated groups was significantly greater than that in the control group, and the difference in tumor volume between treated groups and controls increased with time. However, dose responsiveness was not observed. In antiestrogen-treated or ovariectomized mice, tumor growth was partially inhibited only at the early stages. The mean survival time of estrogen-treated and ovariectomized groups was shorter than that of controls, while that of the antiestrogen-treated group was identical to that of controls. Histologically, no specifically different types of differentiated tissues were observed in any group. Our experiments show that estrogen is one important factor which stimulates the growth of one form of teratocarcinoma.
Two new soluble placental tissue proteins (PP13 and PP17) have been isolated and characterized. PP13 has an electrophoretic mobility the same as that of albumin, an isoelectric point in the range 4.7-4.8 and a sedimentation coefficient of 3.1 S. Its molecular weight was found to be 30 000. PP13 appears to be composed of two identical subunits which are held together by disulfide bonds. PP17 has an electrophoretic mobility in between the beta 1- and alpha 2-globulins, an isoelectric point in the range 5.2-5.3 and a sedimentation coefficient of 2.7 S. Its molecular weight was determined to be 30 300 by ultracentrifugation and 38 000 by SDS-polyacrylamide gel electrophoresis. PP17 apparently consists of a single peptide chain. The amino acid and carbohydrate compositions of these proteins also have been determined. Immunochemical methods were used to detect and quantitate the new proteins in extracts of placental and other human tissues as well as in body fluids. From one human term placenta an average of 3.7 mg PP13 and 2.5 mg PP17 could be extracted. In concentrated extracts of other human tissues and in body fluids, these proteins could not be detected, at least not in concentrations higher than 1 mg/dl. The immunohistochemical localization of these proteins as well as measurement of their concentrations in body fluids by sensitive radioimmunoassays are presently under investigation.
