Enhanced cardiotoxicity in rabbits treated with verapamil and adriamycin

Verapamil, a calcium channel blocker, reduces resistance of some tumors to Adriamycin by inhibiting Adriamycin efflux from resistant cells. This study shows that rabbits given 7 mg/kg of Adriamycin and 0.8 mg/kg of verapamil died earlier with functional and morphological cardiac abnormalities than rabbits given Adriamycin alone. Rabbits that were given verapamil and died peracutely had higher concentrations of Adriamycin in the myocardium. The relatively high dose of Adriamycin was expected to produce cardiotoxicity in rabbits within a matter of days. However, peracute death (within hours) in rabbits given the same dose of Adriamycin but with verapamil treatment was unexpected. These results suggest that combining Adriamycin with verapamil increases early cardiac toxicity. Therefore, clinical use of this combination should be approached cautiously until the interactions, including the possibility for enhanced normal tissue damage, are fully understood.

Daunorubicin-induced DNA lesions in isolated rat hepatocytes and mammary epithelial cells

Daunorubicin, an anticancer drug, induces primarily mammary adenocarcinoma in Sprague-Dawley rats. We investigated daunorubicin-induced DNA lesions in enzymatically isolated mammary epithelial cells and hepatocytes from 7-8-week-old female Sprague-Dawley rats. Differences were observed in the type and quantity of DNA lesions in mammary epithelial cells and hepatocytes as determined by alkaline elution analysis. DNA single-strand breaks and proteinase-K-sensitive cross-linking lesions were observed in mammary epithelial cells. Hepatocytes appeared to have significantly lower relative frequencies of single-strand breaks than mammary epithelial cells when treated with daunorubicin (1.5-10.0 micrograms/10(6) cells). Hepatocytes displayed two types of cross-link. One form was sensitive to proteinase-K digestion, whereas the other form was insensitive. The metabolism of daunorubicin to the aglycone metabolites was substantially lower in mammary cells than in hepatocytes. However, the total uptake of the drug was similar in these two cell types. A metabolite, 7-deoxydaunorubicinol aglycone, was unable to induce single-strand breaks or cross-linking lesions in mammary epithelial cells. Both cell types exhibited a similar ability to repair radiation-induced single-strand breaks of DNA. However, the mammary cells may be less able to repair daunorubicin-mediated DNA damage. These results revealed that mammary epithelial cells are less able to metabolize the active mutagen/carcinogen, daunorubicin, than are hepatocytes. This, coupled with the observations of greater apparent DNA damage in mammary cells, may be of primary importance in the drug-induced carcinogenicity in the rat mammary tissue.

Enzyme-linked immunosorbent assay using Mycobacterium tuberculosis antigen 5 for the diagnosis of pulmonary tuberculosis in China

Measurement of serum IgG antibody to Mycobacterium tuberculosis antigen 5 by enzyme-linked immunosorbent assay was evaluated as a serodiagnostic test for pulmonary tuberculosis in China. The test was 89% sensitive and 94 to 100% specific with high accuracies of prediction. Among 82 tuberculous patients, antibody titer was related to the extent of pulmonary disease. Among control subjects, false positive tests were encountered among 5 of 52 persons with other pulmonary disease and not among 30 healthy subjects. The characteristics of this test compare favorably with those reported for sputum smear examination.

[Carcinoembryonic antigen and immunoglobin in gastric juice in the diagnosis of gastric cancer]

Levels of carcinoembryonic antigen (CEA) and immunoglobin (Ig) in gastric juice of 93 patients with benign and malignant gastric diseases were assayed. The CEA level in gastric cancer patients (55.73 +/- 38.26 ng/ml) was obviously higher than that in peptic ulcer (15.51 +/- 12.09 ng/ml) and superficial gastritis (26.96 +/- 20.17 ng/ml). But no significant difference was found between the CEA levels of gastric cancer and chronic atrophic gastritis (48.66 +/- 31.87 ng/ml). Also, elevated CEA was closely correlated to intestinal metaplasia. The positive rate of Ig was significantly higher in gastric cancer (IgG greater than or equal to 185 ug/ml, IgA greater than or equal to 100 ug/ml) than in benign gastric diseases. Although no correlation is present in the CEA and Ig in gastric juice, the combination of these two methods could improve the diagnostic accuracy. We believe that the two assays are worthy for screening gastric cancer from patients with high risk, and for identifying precancerous lesions.

[Circulating immune complex and cancer in the digestive system]

The zone electrophoresis on agarose was used to determine the incidence of circulating immune complex (CIC) in blood of 60 patients with cancer in the digestive system and 42 healthy donors. The correlation between cancer and CIC was investigated. The positive results is 75% in patients and 14.2% in the control. There is a significant correlation between the CIC and the stage of lesion. Higher incidence was observed in patients with stage I and II lesions (100% and 85%) than those with stage III lesions (40%). Among 13 positive patients, 5 with stage I lesion became negative and 8 with stage II or III lesions were still positive after operation. These data suggest that the zone electrophoresis be a reliable assay for the diagnosis and prognosis of patients with digestive system cancer. To measure the CIC periodically may be useful for the follow up of the tumor condition before and after treatment.

Comparison of intra-arterial cis-diamminedichloroplatinum II with high-dose methotrexate and citrovorum factor rescue in the treatment of primary osteosarcoma

A randomized two-arm study was undertaken to determine relative tumoricidal effects of intra-arterial cis-diamminedichloroplatinum II (I/A-CDP) and high-dose methotrexate with citrovorum factor rescue (MTX-CF) in the treatment of the primary tumor in patients with osteosarcoma. Responses were evaluated by clinical, radiographic, angiographic, and pathologic parameters. Fifteen patients were randomized to receive MTX-CF and 15 to I/A-CDP. In the MTX-CF arm there were four responses (three complete responses, one partial response) whereas in the I/A CDP arm there were nine responses (seven complete responses, two partial responses). Two patients who failed MTX-CF and requested alternative treatment with I/A-CDP also responded. The total I/A-CDP response was 11/17.

Altered fucosylation of membrane glycoproteins from cystic fibrosis fibroblasts

Peripheral membrane glycopeptides isolated from skin fibroblasts of patients with cystic fibrosis (CF) had an altered fucosylation when compared to age, race, and sex-matched controls. Glycopeptides obtained by trypsin treatment of cultured cells, metabolically labeled with L-[3H]fucose, were purified on a Sephadex G-50 column. The neutral monosaccharide composition of the glycopeptides was determined by gas-liquid chromatography of the alditol acetate derivatives. The fucose content of the CF membrane glycopeptides and the molar ratio of fucose to the other monosaccharides were increased when compared with those of controls. The mean fucose content was 2.3 +/- 1.7 (SD) and 0.3 +/- 0.05 (SD) nmol per 10(6) cells for CF control glycopeptides, respectively. Moreover, the specific activity of incorporated L-[3H]fucose was markedly decreased in the CF glycopeptides, 355 +/- 183 (SD) and 2707 +/- 839 (SD) cpm per nmol of fucose for the CF and controls, respectively. The membrane glycopeptides were further purified and characterized by affinity chromatography on immobilized lectins. The decreased specific activity of incorporated fucose was present in CF glycopeptides which bound to immobilized lentil lectin before and after Pronase degradation. Moreover, the CF glycopeptides bound more tightly to lentil lectin. Several classes of glycopeptides bind to lentil lectin and all contain Fuc alpha 1----6GlcNAc at the core. The binding characteristics of the Pronase-digested membrane glycopeptides for immobilized concanavalin A, lentil leukoagglutinating phytohemagglutinin, erythroagglutinating phytohemagglutinin, and serotonin provided information on the structure of the altered CF glycopeptides. Most of these radioactive glycopeptides were of the biantennary type containing at least one sialic acid residue and all containing fucosyl residues at the asparagine core.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of nutritional depletion and repletion on plasma methotrexate pharmacokinetics

Clinically, a relationship exists among nutritional status, drug responsiveness, and host toxicity, but the effects of nutrition on chemotherapy drug metabolism are relatively unknown. This article evaluates the effect of malnutrition and nutritional repletion on plasma methotrexate (MTX) pharmacokinetics. In Study I, 55 non-tumor-bearing rats were fed regular diet (RD) (N = 27) or protein-free diet (PFD) (N = 28) for 10 days. On day 10, MTX 20 mg/kg was injected intraperitoneally and four to six animals in each group were killed at 30 minutes, 1, 2, 6, 24, and 48 hours following MTX administration. Plasma MTX was measured by dihydrofolate reductase enzyme inhibition assay and was found to be significantly elevated (P less than 0.01) in PFD animals as compared with RD animals at 1 and 2 hours following MTX injection. In Study II, 87 tumor-bearing rats were fed RD (N = 29) or PFD (N = 58) for 10 days. At this time, 27 PFD rats were switched to RD (PFD----RD), while 31 rats remained on PFD. MTX 20 mg/kg was injected intraperitoneally and six to eight rats in each group were killed at 1, 2, 6, and 24 hours post-MTX injection. Mean levels were found to be significantly elevated at 2, 6, and 24 hours in PFD (P less than 0.01) and PFD----RD (P less than 0.05) compared with RD rats. Several investigators have shown that increased plasma MTX levels at 24 and 48 hours after drug administration correlates with host toxicity in patients receiving chemotherapy. In this experimental study, malnutrition delayed plasma MTX clearance, and nutritional repletion for 2 days was insufficient to return MTX pharmacokinetics to normal. These results in experimental animals suggest an explanation for increased MTX toxicity in malnourished individuals.

Systemic thermochemotherapy: toxicity and plasma pharmacokinetics of methotrexate and doxorubicin

Chemotherapy administered during systemic hyperthermia is more tumoricidal than either modality used alone. The purpose of this study was to evaluate plasma drug pharmacokinetics and host toxicity when methotrexate (MTX) or doxorubicin (adriamycin--ADR) was given at 37 or 43 degrees C. Eight dogs were heated to 43 degrees C for 1 hr without chemotherapy; eight dogs received MTX (5 mg/kg) and four dogs received ADR (2 mg/kg) intravenously as a constant infusion at 43 or 37 degrees C. Blood samples were obtained at 0, 1, 2, 24, and 48 hr. Mean plasma MTX levels were not significantly different at 1, 2, and 6 hours in 43 and 37 degrees C dogs, but at 24 and 48 hr mean plasma MTX levels were significantly elevated in heated (43 degrees C) dogs compared with sham-heated (37 degrees C) dogs. Plasma MTX concentration multiplied by time (area under curve) was 131 g . hr/liter in 43 degrees C dogs compared with 73 g . hr/liter in 37 degrees C dogs (P less than 0.001). Vomiting and bloody diarrhea lasted an average of 4 days in heated control dogs (no drugs) 4 days in 37 degrees C dogs, and 5 to 7 days in 43 degrees C MTX dogs. Mean plasma ADR levels were similar in 37 and 43 degrees C dogs at all time intervals. Vomiting and bloody diarrhea lasted at least 7 days in 43 degrees C dogs compared with only 1 day in 37 degrees C dogs treated with ADR.(ABSTRACT TRUNCATED AT 250 WORDS)

Central nervous system pharmacology of Baker's antifolate (NSC139105) in man

Radiolabelled Baker's Antifolate (BAF) was administered to 6 patients undergoing surgical resection of intracerebral tumors. Levels of radioactivity in resected tumor and edematous brain adjacent to tumor were generally higher than levels in concurrent plasma samples and were generally comparable to levels in temporalis muscle. Levels in tumor cyst fluid were far lower than concurrent plasma levels and levels in surrounding tumor. Chromatography was performed on tumor from 2 patients and revealed that only a small proportion of the radioactivity represented unchanged BAF. The major metabolite present in tissues was 1 000 times less potent as an inhibitor of dihydrofolate reductase than was BAF. Five patients had cerebrospinal fluid (CSF) sampled following administration of tracer doses of radiolabelled BAF. Radioactivity levels were far lower in CSF than in plasma. Levels of radioactivity in the CSF were also far lower than levels in tumor and brain samples from other patients and were slightly lower than tumor cyst fluid levels. Two patients had CSF collected after they received therapeutic doses of BAF. In these patients, both CSF and plasma were assayed using a dihydrofolate reductase inhibition assay. As with tracer dose studies, CSF concentrations of BAF were substantially lower than were concurrent plasma concentrations. Thus it appears that only very low concentrations of BAF are attainable in human CSF and intracerebral tumor, although a metabolite which is a very weak inhibitor of dihydrofolate reductase attains high concentrations in tumor.