Phase II study of 2'-deoxycoformycin in patients with renal cell carcinoma. A National Cancer Institute of Canada Clinical Trials Group study

The National Cancer Institute of Canada Clinical Trials Group undertook a phase II study of 2'-deoxycoformycin in patients with metastatic renal cell carcinoma. When 2'-deoxycoformycin 4 mg/m2 was administered intravenously weekly for three weeks then every two weeks no significant antitumor activity was noted in 19 evaluable patients. Toxic effects experienced were as expected, consisting primarily of nausea/vomiting, anorexia, and lethargy. It is concluded that 2'-deoxycoformycin at this dose and schedule has no clinical activity in the treatment of metastatic renal cell carcinoma.

Fibrinolytic activity of rat plasma during development of Guerin epithelioma

Fibrinolytic activity in the blood of rats during the development of Guerin epithelioma was studied. It was measured by means of radiometric method, based on the amount of plasmin degradation products released from 125I-fibrin, as well as by means of amidolytic technique with the use of Chromozym PL. During the initial phase of epithelioma development the fibrinolytic activity of plasma, determined after inactivating plasma proteinase inhibitors, increases. It also increases in the euglobulin fraction. Simultaneously, the content of fibrin(ogen) degradation products (FDP) increases in the blood. During the stage of the intensive development of neoplastic disease fibrinolytic activity as well as plasminogen activator activity become inhibited, whereas the concentration of FDP retains the level observed in healthy animals. Inhibition of fibrinolytic activity in the later phase of the disease coincides with the appearance of low-molecular weight antifibrinolytic factor in the blood of rats loaded with epithelioma.

Phase II study of amonafide: results of treatment and lessons learned from the study of an investigational agent in previously untreated patients with extensive small-cell lung cancer

Thirteen previously untreated patients with extensive small-cell lung cancer (SCLC) were treated with the investigational agent amonafide in a dose of 300 mg/m2 intravenously (IV) over 1 hour daily for 5 consecutive days. No responses were seen in 12 eligible patients. Myelosuppression was only occasionally seen. Other toxicities included diaphoresis, chest pain, local irritation at the injection site, arthralgias, nausea and vomiting, and neuromuscular problems. There were two early deaths, both attributable to tumor progression with resultant obstruction of a vital structure. Ten patients crossed over to alternate active therapy (etoposide [VP-16]-cisplatin) and five responded. The median survival time (MST) of the whole group of treated patients was 31 weeks. In future trials of investigational new drugs in previously untreated SCLC, we recommend that patients with the following characteristics be excluded: Eastern Cooperative Oncology Group (ECOG) performance status 2, 3, and 4; superior vena cava (SVC) obstruction; any major paraneoplastic syndrome; serious comorbid illness; and extensive hepatic involvement by tumor. The trial design should include prompt crossover to active alternative therapy, such as VP-16 and cisplatin, for disease progression or for failure to respond after two treatment cycles. Also, the trial design should use an early stopping rule based on interest in identifying only very active agents with a minimum response rate of 30%.

Epirubicin in extensive small-cell lung cancer: a phase II study in previously untreated patients: a National Cancer Institute of Canada Clinical Trials Group Study

The Clinical Trials Group of the National Cancer Institute of Canada (NCIC) studied single-agent epirubicin in 40 previously untreated patients with extensive small-cell lung cancer (SCLC). The starting dose of epirubicin was 100 (eight patients) or 120 (32 patients) mg/m2 administered intravenously every 3 weeks. Twenty patients (50%) achieved an objective response (95% confidence limits, 33% to 66%) and three of the 20 had complete responses (CRs). The median survival of all 40 patients was 8.3 months (35.4 weeks). Myelosuppression, mild or moderate nausea and vomiting, and hair loss were commonly seen. There was one chemotherapy-related death. This drug is active and well tolerated in SCLC and the use of it as first-line therapy did not appear to compromise survival in this group of patients.

Cancer procoagulant in serum of rats during development of experimental epithelioma

The activity of cancer procoagulant (CP) during the development of Guérin epithelioma was studied in the blood of Wistar rats. Blood was collected from the carotid artery and, after clotting, proteins adsorbing on aluminum hydroxide were removed from the serum. Then procoagulant activity was determined in the test system without factor VII by means of substrate S-2222 specific for factor Xa. A statistically significant increase in the activity of CP in serum was detected, coinciding with the period of intensive tumor growth (15th-25th day of disease).

5-Fluorouracil with folinic acid is not effective against metastatic adenocarcinoma of the lung

Thirty patients with a diagnosis of metastatic adenocarcinoma of the lung were entered on a trial to evaluate the antitumor efficacy of 5-fluorouracil 370 mg/m2 daily for 5 days every four weeks in combination with folinic acid 200 mg/m2, 60 min prior to 5FU. All patients had a good performance status, bidimensionally measurable disease, and weight loss less than or equal to 5% of preillness weight. Of the 29 evaluable patients, only two (7%) had partial responses (95% confidence limits 1-24%). Eleven (38%) had stable disease and 16 (55%) progressed. The two responding patients survived 12 and 60+ weeks. The median survival of all evaluable patients was 25 weeks (range 7-60+) and that of the stable patients was 26 weeks. The principal toxicities observed were diarrhea and stomatitis. Myelosuppression was rarely dose limiting. In contrast to the results of treatment with 5FU and folinic acid in metastatic colorectal cancer and breast cancer, the results of treatment with this combination of agents have been much less encouraging in adenocarcinoma of the lung.

Procoagulant activity of human stomach and colon cancers

Procoagulant activity in extracts from human stomach and colon cancers was examined, using chromogenic substrate S-2222. The activity of direct activator of factor X varied between 6 and 96% of total procoagulant activity of the tested extracts. The direct activator of factor X from stomach cancer was sensitive to heating and was inhibited by phenylmethylsulphonylfluoride and also by iodoacetic acid and HgCl2. Such results lead to the assumption that investigated activator is of enzymatic nature.

Low molecular weight fibrinolytic inhibitor from Guerin epithelioma

Antifibrinolytic activity of the extract from Guerin epithelioma, a highly metastatic tumour implanted to rats, was determined by fibrinolytic and zymographic methods. The extract exhibits antifibrinolytic activity which is thermostable (60-100 degrees C) and pH-stable (pH 2.7-12). It contains a fibrinolytic inhibitor, with Mr about 7000, with antiplasmin properties, bound to lys-Sepharose and heparin-Sepharose. The molecular weight, physicochemical properties and antiplasmin action of the epithelioma inhibitor prove its identity with the low molecular weight antifibrinolytic factor appearing in the plasma of rats during the development of this tumour.

Fibrinolytic inhibitors from the experimental rat epithelioma

Guerin epithelioma, a highly metastatic tumour implanted to Wistar rats contains two inhibitors of fibrinolysis which can be detected with the use of zymographic techniques. The first one--with Mr about 48000 forms SDS-stable complex with urokinase. The second--with Mr about 7000 inhibits fibrinolytic and amidolytic activity of plasmin.

Blood coagulation changes in rats poisoned with methylmercuric chloride (MeHg)

The effects of methylmercuric chloride on the coagulability of blood were studied in rats. The administration of a single dose (17.9 mg Hg/kg) and a repeated dose (5 X 8 mg Hg/kg/day) of this compound resulted in hypercoagulation. The reduction of the clotting time, the increase of fibrinogen level in plasma and changes characteristic of hypercoagulation in the thromboelastographic parameters were observed. Simultaneously, signs of impaired activity of blood platelets: decreased aggregation velocity and clot retraction as well as prolongation of the bleeding time were noticed.

A phase II study of VP-16 and cisplatin in patients with unresectable malignant mesothelioma. An NCI Canada Clinical Trials Group Study

The National Cancer Institute of Canada (NCIC) Clinical Trials Group has carried out a phase II study of VP-16 100 mg/m2 daily x 3 and cisplatin 25 mg/m2 daily x 3 in untreated patients with malignant mesothelioma. Twenty-seven eligible patients were entered on the trial and the majority had pleural and/or soft tissue disease. Myelosuppression and gastrointestinal symptoms were the most common toxicities, and were usually mild or moderate in severity. Only 3 partial responses were seen in the 26 patients evaluable (12%). We conclude that the combination of VP-16 and cisplatin when used in this fashion has only minimal activity in mesothelioma.

Coagulation and fibrinolysis in rats poisoned with mercuric chloride

The effect of mercuric chloride on blood coagulation and fibrinolysis in rats was studied. The mercurial was administered to the animals intragastrically in a single dose of 17.9 mg Hg/kg and the effects were tested on the 1st, 3rd and 7th day. The symptoms of hypercoagulability accompanied by decreased fibrinolytic activity of the plasma were observed in the poisoned rats. The main reason of the lowered fibrinolytic activity seemed to be the inhibition of plasma plasminogen activator or the inhibition of plasminogen activation reaction catalyzed by this enzyme.

Plasma and platelet fibrin-stabilizing factor activity in rats intoxicated with phenylmercuric acetate

Effect of phenylmercuric acetate on the activity of rat plasma and platelet fibrin-stabilizing factor (FSF) was studied. The mercurial was administered to the animals intragastrically in a single dose of 17.9 mg Hg/kg or in repeated doses of 1.79 mg Hg/kg, twice a week for 152 days. The activities of the investigated fibrin-stabilizing factors were significantly increased in the case of intoxicated rats. Such an effect was observed in both types of the exposure.

Interaction of fibrinogen with mercury

The interaction of bovine fibrinogen with mercuric chloride was studied. Gel filtration on Sephadex G-25 revealed that fibrinogen bound twice the amount of mercury such as fibrin or fibrin monomers (8.8, 4.5, and 3.4 micrograms Hg2+ ions/mg protein, respectively). Fibrinogen complexed with mercury or in the presence of Hg2+ ions at concentration above 10-6 M was clotted by thrombin more effectively than in the control system which was devoid of this metal. Reaggregation of the purified fibrin monomers was not affected by mercury.

Immunospecificity of nuclear antigens in chicken erythroid cells

Specific antisera were produced against chicken reticulocyte dehistonized chromatin. The antisera reacts strongly with chicken reticulocyte chromatin, but only marginally with chicken erythrocyte chromatin. There is no reticulocyte antigen detected in chicken liver. Reticulocyte maturation is accompanied by a gradual decrease in the chromatin immunological activity and template capacity. The reduction of immunological activity is due to the change of chromatin conformation during erythrocyte maturation. Dehistonization and sonication of erythrocyte chromatin raises the erythrocyte chromatin immunological activity to levels similar to those of reticulocyte chromatin. The erythrocyte nuclear antigens are class specific, not being found in frog erythroid cell or murine Friend leukemia cell chromatins.

Chicken reticulocyte nuclear antigen: its identification and relation to transcriptive activity in erythropoietic cells

Antibodies to chicken reticulocyte dehistonized chromatin were produced. These antibodies can distinguish between chromatin from reticulocytes and erythrocytes and have no activity with chicken liver chromatin. The antibodies will also differentiate between reticulocytes and erythrocytes by the the horseradish peroxidase bridge localization technique. The nonhistone protein components of the antigenic complex are very tightly bound to the DNA, removable by extraction with sodium dodecyl sulfate but not 2.5 M NaCl-5 M urea. Our data indicate that the antigen complexes could actually be present in both reticulocytes and erythrocytes but that chromatin condensation causes a structural masking of the complexes which coincides with the known decline in transcriptive activity of the erythrocyte.