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Biomedical subjects

N H Mulder

Publications and source records attributed to N H Mulder.

At least 181 records · Page 10Linked to original sources
PubMed1992

Phase II study of subcutaneous interleukin-2 in unselected patients with advanced renal cell cancer on an outpatient basis.

PURPOSE: A single-institution phase II study was undertaken to evaluate the efficacy and toxicity of interleukin-2 (IL-2) administered by subcutaneous injection. PATIENTS AND METHODS: Twenty-seven unselected patients (15 male) with a mean age of 60 years (range, 42 to 76 years) who had advanced renal cell cancer were treated as outpatients. IL-2 was given once a day, 5 days per week for 6 weeks. During the first 5-day cycle, 18 x 10(6) IU was given once daily; in the following cycles, the doses in the first 2 days were reduced to 9 x 10(6) IU. After a 3-week rest period, treatment was repeated in patients who had a response or stable disease (SD). To prevent pyretic reactions, patients also received acetaminophen (250 to 500 mg given orally every 4 to 6 hours). RESULTS: After 6 weeks, 26 patients were assessable for response. Two patients (8%) had a complete remission (CR), four (15%) had a partial remission (PR), and 13 (50%) had SD. A second cycle of 6 weeks was given to 19 patients; one patient with a PR and six with SD showed progression. Duration of the CR was 17+ and 19+ months, and length of the PR was 2, 8, 11, and 11+ months. The median survival of the patients who were nonresponders and responders was 10 and 20+ months, respectively, and for all patients was 13 months. One patient died as a result of myocardial infarction and brain stem ischemia. Systemic side effects in the other patients were tolerated and accepted, and included transient inflammation and local induration at the injection sites, fever and chills, and nausea. CONCLUSION: Subcutaneous IL-2 is clinically active, has an acceptable toxicity, and can be given to patients with concomitant disease.

Adult↗
PubMed1991

Combined in vitro modulation of adriamycin resistance.

In a P-glycoprotein-negative cell line, GLC4-Adr90, a 75-fold acquired Adriamycin (Adr) resistance coincided with a reduced cellular Adr level, an increased detoxifying capacity (glutathione (GSH) and glutathione S-transferase (GST) elevated), and a reduced topoisomerase-II (topo-II) activity compared with the parent cell line GLC4. The effect on Adr resistance of buthionine sulfoximine (BSO, GSH synthesis inhibitor), was studied alone or in combination with verapamil (drug-efflux inhibitor), docosahexaenoic acid (membrane lipid domain affector), ethacrynic acid (GST inhibitor), aphidicolin (DNA-polymerase-alpha inhibitor) or novobiocin (NOV, topo-II inhibitor). Cytotoxicity was tested using a microculture tetrazolium assay. In GLC4-Adr90, BSO and NOV increased Adr-induced cytotoxicity 12.9-fold and 1.8-fold respectively. The combination of BSO plus NOV showed an additive effect, decreasing the Adr resistance factor from 75 to 2.7. Combination of modulators of Adr resistance directed at different resistance mechanisms appears promising in vitro.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1991

In vitro and in vivo modulation of multi-drug resistance with amiodarone.

The modulating effect on drug resistance of amiodarone (AM) and its metabolite desethylamiodarone (DEA) was studied in a P-glycoprotein-positive human colon carcinoma cell line COLO 320, and a human small-cell lung carcinoma cell line GLC4 and its adriamycin (Adr)-resistant subline GLC4-Adr (both P-glycoprotein-negative). AM, DEA and verapamil induced an increase in cytotoxicity of Adr, vincristine and etoposide (VP16) in COLO 320 cells, while in the GLC4 and GLC4-Adr cell line no effect was seen. In the COLO 320 cell line, AM caused more intracellular, and especially intranuclear, fluorescence of Adr and more Adr-induced DNA strand breaks as compared to Adr alone. Moreover, an increase in VP16-induced topoisomerase II-DNA complexes was observed when AM was added. Competition between AM and Adr for the same efflux pump was suggested in efflux studies. The colony-forming unit granulocyte macrophage (CFU-GM) assay showed no increase in cytotoxicity of Adr when AM was added. Fourteen patients with Adr-resistant tumors were treated with Adr and AM. In these patients, peak serum levels of AM plus DEA of 10 microM were reached. Patient serum (20%) obtained after the first i.v. AM infusion induced in vitro significantly more cell kill of Adr in COLO 320 cells. Apart from a transient first-degree AV block in one patient, no cardiac toxicity was observed with the combination of Adr and AM. Bone-marrow toxicity was the same as expected from Adr alone in these patients. One of the 13 evaluable patients obtained a partial remission.

Adult↗
PubMed1991

A double-blind placebo-controlled study with granulocyte-macrophage colony-stimulating factor during chemotherapy for ovarian carcinoma.

In a placebo-controlled double-blind dose-finding trial, 15 patients with ovarian cancer stage III or IV received daily s.c. 1.5, 3, or 6 micrograms/kg recombinant human granulocyte-macrophage colony-stimulating factor (GM-CSF). At each dose step three patients received recombinant human GM-CSF, and two received placebo. Chemotherapy comprised 6 cycles of carboplatin, 300 mg/m2, and cyclophosphamide, 750 mg/m2, by i.v. bolus on day 1 every 4 weeks. GM-CSF, given on days 6-12 on an outpatient basis, raised the mean leukocyte count on days 7, 10, and 15 and the mean neutrophil count on days 7 and 10 at all dose levels as compared with the control group. Neutrophil counts of less than 0.5 x 10(9)/liter occurred in 20 of 22 cycles in the control group and in 5 of 17 cycles at the 6-micrograms/kg/day GM-CSF dose level (P less than 0.0005). In comparison with the control group, the mean eosinophil count was higher on days 10 and 15 at all GM-CSF doses, as was the mean monocyte count on day 15. The mean platelet count was raised at the 3- and 6-micrograms GM-CSF doses on days 15 and 22. Chemotherapy dose reduction or postponement due to myelotoxicity occurred in 9 of 28 cycles in the placebo groups versus 5 of 44 cycles in the GM-CSF group (not significant). Local skin infiltrates at the GM-CSF injection sites occurred in 8/9 patients, leading to premature removal of two patients from the study. Capillary leakage of 131I-albumin was increased in all patients 5 days after the first chemotherapy course but was not significantly affected by 4 days of GM-CSF treatment. Tumor necrosis factor alpha and C-reactive protein serum levels increased during GM-CSF administration at the 6-micrograms dose level, but interleukin 6 serum levels were not affected. We conclude that a dose of 3 and 6 micrograms/kg/day GM-CSF reduces the severity of neutropenia and thrombocytopenia after carboplatin-cyclophosphamide. This GM-CSF dose does not induce additional capillary leakage.

Adult↗
PubMed1991

Chemotherapy and surgery for locally advanced cancer of the cardia and fundus: phase II study with methotrexate and 5-fluorouracil.

Locally advanced cancer of the cardia and fundus might be cured by surgical resection. Poor results after surgery in stage IIIB and stage IV disease prompted a study of neoadjuvant chemotherapy. Treatment included four cycles of high doses of methotrexate (1.5 g/m2) and high doses of 5-fluorouracil (1.5 g/m2) followed by surgery in those patients with lesions then found to be resectable. Twenty patients with tumours staged as IIIB or IV were entered; 17 patients completed the four courses of chemotherapy and 14 underwent re-exploration. Eight patients achieved tumour reduction enabling resection. Five patients underwent total gastrectomy with distal pancreatectomy and splenectomy en bloc and three patients had an oesophagogastrectomy. There were no treatment-related deaths and toxicity was tolerable. Two patients were alive 54 and 41 months after chemotherapy with no evidence of disease. Locoregional recurrence developed in five patients and metastatic disease in one. Their median survival was 22 months.

Adenocarcinoma↗
PubMed1991

Lack of cross-resistance to fostriecin in a human small-cell lung carcinoma cell line showing topoisomerase II-related drug resistance.

Cells exhibiting decreased topoisomerase II (Topo II) activity are resistant to several drugs that require Topo II as an intermediate. These drugs are cytotoxic due to the formation of a cleavable complex between the drug, Topo II and DNA. Fostriecin belongs to a new class of drugs that inhibit Topo II without inducing the formation of this cleavable complex. We tested fostriecin in three human small-cell lung carcinoma cell lines. GLC4 is the parent line. GLC4/ADR is the P-glycoprotein-negative multidrug-resistant subline, which is resistant to several Topo II inhibitors due to its decreased Topo II activity. GLC4/cDDP is the cisplatin-resistant subline, which displays increased Topo II activity. Topo II activity proved to be 100% in GLC4, 35% in GLC4/ADR and 130% in GLC4/cDDP. The fostriecin concentration causing inhibition of the growth of 50% of the cells (IC50) in the microculture tetrazolium assay following continuous incubation was 11.2, 4.1 and 14.9 microM, respectively. After 1-h incubations, the IC50 was 117.8, 101.3 and 219.8 microM, respectively. Our results indicate a relationship between Topo II activity and fostriecin sensitivity in these closely related cell lines. At least in vitro, fostriecin displayed the capacity to kill cells showing resistance to drugs due to decreased Topo II activity. There was no relationship between this capacity and an increase in the activity of the reduced-folate carrier system, the proposed mechanism for cellular entry of fostriecin, since we found no correlation between the cytotoxicity of fostriecin and that of methotrexate.

Alkenes↗
PubMed1991

Alternating cycles of PVB and BEP in the treatment of patients with advanced seminoma.

33 patients (median age 39 years) with advanced seminoma were treated with 4 courses of alternating cisplatin-containing chemotherapy PVB/BEP (cisplatin, vinblastine and bleomycin; bleomycin, etoposide and cisplatin). Patients were classified as stage IIC (n = 7), IID (n = 9), III (n = 13) and IV (n = 4). 8 had had prior radiotherapy; 9 had an elevated beta human chorionic gonadotropin (beta HCG). 30 patients were evaluable for response and 33 for toxicity. During chemotherapy 3 patients died, 1 due to malignant disease, another due to a cardiac arrest, and 1 patient of a bleomycin pneumonitis. 13 (43%) had a complete remission and 17 (57%) had a clinical partial remission (residual radiographic mass). At a median follow-up of 28 months (range 16-88), 3 patients relapsed, 6-8 months after entry. After completion of therapy there were 2 deaths, 1 due to bleomycin pneumonitis and 1 neither tumour nor treatment related. 26 of 33 (79%) patients achieved a continuously disease-free status. Leucocytopenia and thrombocytopenia of WHO grade 3/4 occurred in, respectively, 32/33 (97%) and 20/33 (61%) of the patients. This study shows that alternating PVB/BEP in this group yields comparable response rates with non-alternating schedules but at the expense of considerable toxicity.

Adult↗
PubMed1991

CA-125 in ovarian cancer: relation between half-life, doubling time and survival.

In a retrospective study of 35 patients with stage III-IV ovarian cancer, the probability to reach a complete (CR) or partial remission (PR) was studied by comparing the initial level, half-life and normalisation time of CA-125 during chemotherapy. In 15 CR patients, pretreatment CA-125 level was lower (70 U/l, range 16-1500 U/l) than in 20 PR patients (800 U/l, range 60-9000 U/l). The median normalisation time (NT) was 6 weeks in CR (range 0.7-5.5 months) and 4 months in PR patients (range 1.2-9 months). Marker half-life was 12 days for the CR group (range 4.5-30 days) and 21 days for the PR group (range 5.5-39 days). Remission duration (r = 0.56) and log cell kill (r = 0.72) were correlated with survival. Combining initial tumour diameter, marker level and NT predicted CR in 87.5% and PR in 86%. Estimating log cell kill by combining marker half-life and doubling time gives more insight into tumour cell kinetics and individual survival.

Antigens, Tumor-Associated, Carbohydrate↗
PubMed1991

Continuous infusion of chemotherapy on an outpatient basis via a totally implanted venous access port.

170 patients were treated with continuous infusion of epirubicin, mitoxantrone, carboplatin or 5-fluorouracil through an implanted venous access port with a portable infusion pump. A total of 440 cycles were given on an outpatient basis. The patients were instructed how to dissolve their drugs and to change the syringes. The complication rate was low. 10 patients developed a thrombosis of the subclavian vein, resulting in cessation of therapy in 5. Pulmonary embolism occurred twice, in 1 patient during a period of subclavian vein thrombosis. Needle dislocation occurred 6 times and catheter occlusion 20 times. Patency was restored with saline or urokinase. Local infection occurred 3 times and systemic infection only once. This technique is suitable for continuous infusion of different cytostatic drugs on an outpatient basis. Patients were able to prepare their drugs at home and the system can remain in situ for 3 weeks without increasing the complication rate.

Adult↗
PubMed1991

NMR spectroscopy analysis of phosphorus metabolites and the effect of adriamycin on these metabolite levels in an adriamycin-sensitive and -resistant human small cell lung carcinoma cell line.

31P nuclear magnetic resonance (NMR) spectra of cells and of cell extract revealed high levels of phosphorylcholine (PC) and phosphocreatine (PCr) in an adriamycin-resistant human small cell lung carcinoma cell line (GLC4/ADR) and the adriamycin-sensitive parental cell line (GLC4). PCr levels in extracts of GLC4/ADR were increased compared to extracts of GLC4. We estimated that 11% of the total intracellular ATP is not bound to Mg2+ in both cell lines. This value corresponded to an intracellular free Mg2+ of 0.30 mM. The effects of different adriamycin concentrations, 0.05, 1 and 30 microM for GLC4 and 1, 30 and 200 microM for GLC4/ADR, on the phosphorus metabolite levels in continuously perfused cells were monitored. Significant differences between GLC4 and GLC4/ADR included: (a) a strong increase in the beta ATP level in the presence of 30 microM adriamycin in GLC4 only, followed by a fast decrease after 5 h of perfusion. (b) a less dramatic increase in the PC level in GLC4/ADR and an unchanged ATP level in the presence of increasing adriamycin concentrations. (c) an increased GPC level in GLC4/ADR in the presence of adriamycin. The changes in PC and GPC levels in the presence of adriamycin suggested that the phospholipid turnover was increased in GLC4/ADR and could be stimulated in the presence of adriamycin. In both cell lines, PCr levels decreased faster than the ATP levels after adriamycin treatment. Thus, biochemical markers for adriamycin resistance can be detected with NMR spectroscopy. However, more studies are necessary to obtain parameters to distinguish drug-sensitive from drug-resistant tumours in patients by NMR spectroscopy.

Adenosine Triphosphate↗
PubMed1991

Continuous infusion carboplatin on a 21-day schedule: a phase I and pharmacokinetic study.

A phase I study with continuous infusion carboplatin for 21 days every 6 weeks using a venous access port and portable pump was performed over a dose range of 12 to 32 mg/m2/d, with increments of 2 mg/m2/d. Forty-four patients received 107 courses (median, two; range, one to nine). World Health Organization (WHO) grade III/IV leukopenia and thrombocytopenia occurred in one of seven patients at 30 mg/m2/d, and in two of six and four of six patients at 32 mg/m2/d. Cumulative platelet depression was found at dose levels of 28 mg/m2/d or more. Median glomerular filtration rate (GFR) and effective renal plasma flow, monitored by radioisotope clearances at doses greater than or equal to 20 mg/m2/d, decreased 8.2% (P less than .05) and 10.9% (P less than .01) after two courses. There was a relationship (r = .50, P less than .0002) between the percentage of platelet depression and GFR. No other toxicity was observed. Of the 17 patients who were evaluable, one complete response and four partial responses were observed. In addition, six patients had stable disease. Pharmacokinetic analysis of total and ultrafiltrable platinum (UFPt) was performed by atomic absorption spectrophotometry. Steady-state plasma levels for UFPt were reached after 8 hours. These levels could be detected from the 20 mg/m2/d dose. During steady state, carboplatin dose and UFPt plasma levels were not correlated, but steady-state UFPt and GFR (r = -.27, P less than .05) were. Twenty-four percent of total platinum (Pt) was present as UFPt during steady state (x = 160 +/- 10 micrograms/L). Total body clearance of UFPt exceeded GFR 2.2 times. Mean area under the curve (AUC) for UFPt during continuous infusion was 4,921.8 +/- 301.72 mg.min/L. For total Pt, steady-state plasma levels were not reached; total Pt plasma levels increased between day 7 and day 21 (P less than .0001). There was a significant relation between total Pt serum levels day 7, 14, and 21 and the drug dose administered. Immunohistochemical analysis of DNA-bound Pt in leukocytes showed a linear increase from day 7 to day 14 to day 21 (r = .97) between DNA-bound Pt and duration of infusion in individual patients. The maximum-tolerable dose of carboplatin is 30 mg/m2/d for 21 days (total dose 630 mg/m2) and is recommended for phase II studies.

Adult↗
PubMed1991

Limitations of the fast green assay for chemosensitivity testing in human lung cancer.

Selection of patients with lung cancer who are most likely to benefit from chemotherapeutic treatment would be a substantial step forward. Therefore, a prospective study in predictive chemosensitivity testing in vitro using the fast green assay (FGA) as developed by Weisenthal et al was carried out. Sixty-six pretreatment tumor specimens were obtained, the majority by means of bronchoscopy (n = 42). Due to an initially insufficient yield of tumor cells (n = 19), dead cells in control samples after four-day culture (n = 15), contamination (n = 7), and laboratory failure (n = 2), only 23 (34.8 percent) samples were successfully tested. In 14 of 36 patients, a comparison between in vitro and in vivo response was possible. Taking into account the number of failures, this number of successful assays does not allow for any conclusion regarding accuracy of the FGA. We conclude that the FGA has limited usefulness for in vitro chemosensitivity testing in patients with disseminated lung cancer in whom biopsy specimens were taken without major surgical investigations. Future directions for predictive testing in vitro are discussed.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1991

Calcium and the prevention of colon cancer.

Diet is a major determinant of colon cancer risk. Calcium may protect against colon cancer, presumably by binding cytotoxic bile acids and fatty acids. Numerous studies support this proposition. In subjects at risk for colon cancer oral calcium supplementation has been shown to reduce rectal epithelial proliferation rate, thereby supposedly decreasing cancer risk. In contrast to the original hypothesis that phosphate counteracts the effect of calcium, evidence has now been provided that phosphate is crucial for the intraluminal binding of bile acids in complexes of calcium, phosphate, and bile acids. Supplemental calcium has been shown to reduce the cytotoxic potential of fecal water, which is probably attributable to the profound effect of calcium on bile acid and fatty acid metabolism. However, some reservation with regard to the protective ability of calcium seems to be warranted as we found that oral calcium supplementation caused an increase in epithelial proliferation rate in the sigmoid of patients with adenomatous polyps. Further controlled studies evaluating the effects of calcium on the epithelium of different parts of the colon should now be performed.

Animals↗
PubMed1991

Colorectal carcinoma: an update.

During the last decade important advances have occurred in the fields of understanding genesis, molecular biology, detection of "precancerous data", intervention, and metastatic behaviour of colorectal cancer. An important step forward has been made in adjuvant therapy. Better understanding of 5-fluorouracil metabolism has led to advances in the treatment of metastatic colon cancer. In this review these recent developments as well as future directions are discussed.

Adult↗