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Biomedical subjects

N H Mulder

Publications and source records attributed to N H Mulder.

At least 55 records · Page 3Linked to original sources
PubMed2000

Cardiovascular morbidity in long-term survivors of metastatic testicular cancer.

PURPOSE: To determine whether long-term survivors of metastatic testicular cancer have an increased risk of cardiovascular morbidity more than 10 years after chemotherapy. PATIENTS AND METHODS: Eighty-seven patients treated with cisplatin-containing chemotherapy before 1987 who were in remission for at least 10 years and whose ages were </= 50 years at the time of analysis were evaluated for the occurrence of cardiovascular events. Sixty-two of 87 patients were additionally evaluated for cardiac damage and cardiovascular risk factors. Their cardiovascular risk profile was compared with that of 40 patients with comparable age and follow-up duration treated with orchidectomy only for stage I disease. RESULTS: Major cardiac events were found in five (6%) of the 87 patients (age at time of event, 30 to 42 years; time after chemotherapy, 9 to 16 years): two with myocardial infarction and three with angina pectoris with proven myocardial ischemia. An increased observed-to-expected ratio of 7.1 (95% confidence interval, 1.9 to 18.3) for coronary artery disease, as compared with the general male Dutch population, was found. In addition, one patient experienced a cerebrovascular accident. Exercise ECG did not reveal cases of subclinical coronary artery disease. Echocardiography showed normal systolic left ventricular function in most patients, but diastolic left ventricular function was disturbed in 33% of the patients. Of 62 chemotherapy patients, 79% had hypercholesterolemia, 39% had hypertension, 25% still experienced Raynaud's phenomenon, and 22% had microalbuminuria. Compared with patients with stage I disease, the chemotherapy patients had higher blood pressure and higher total cholesterol and triglyceride levels and were more insulin-resistant. CONCLUSION: In long-term survivors of metastatic testicular cancer, we observed a significantly increased risk for occurrence of cardiac events accompanied by a persisting unfavorable cardiovascular risk profile. Accurate follow-up, focused on cardiovascular complications and aimed at intervention in these young cancer survivors, seems to be important.

Adult↗
PubMed1999

Medical oncology in the next century.

Medical oncology is a relatively young, rapidly growing subspecialty of internal medicine. This discipline will increasingly fulfil a role in the multidisciplinary approach for cancer patients. The fact that the population is rapidly aging, makes it of relevance to train medical oncologists further in the treatment of elderly patients. The growing number of cancer survivors deserves also special attention in order to limit the frequency of long-term side effects. Apart from the classical function as a doctor who treats cancer patients with drugs, the medical oncologist will play an expanding role at the far ends of oncology, namely in prevention and palliative care. Basic sciences create a tremendous amount of new knowledge on cancer detection, behavior and rational drug design. An important task for the medical oncologist will be to translate this expertise to the clinical scenario. The expanding requirement of specific skills of medical oncologists in the next century is likely to cause a further subspecialization within medical oncology.

Cancer Care Facilities↗
PubMed1999

DNA topoisomerase IIalpha and -beta expression in human ovarian cancer.

To study DNA topoisomerase IIalpha (Topo-IIalpha) and -beta expression and regulation in human ovarian cancer, 15 ovarian tumour samples were investigated. To compare different levels of expression, the samples were screened for topo IIalpha and -beta mRNA with Northern blotting and a quantitative reverse transcriptase polymerase chain reaction (RT-PCR) assay for Topo-IIalpha mRNA. Additionally, protein levels were determined with Western blotting and topoisomerase II activity levels with the decatenation assay. The results obtained were compared with each other and with the tumour volume index of the samples. In tumours with a tumour volume index > or = 50%, the mRNA levels (as determined by Northern blotting) and protein levels for each isozyme were in accordance. Additionally, correlations were found between Topo-IIalpha RT-PCR data and Topo-IIalpha Northern blot results, and between Topo-IIalpha RT-PCR data and Topo-IIalpha protein levels. Interestingly, Topo-IIbeta protein levels correlated better with Topo-II activity than Topo-IIalpha protein levels. In eight ovarian cystadenoma samples, no Topo-IIalpha protein could be found. In only three out of eight of these cystadenomas, Topo-IIbeta protein could be detected. These findings suggest that Topo-IIalpha and Topo-IIbeta protein levels are up-regulated in ovarian cancer and may indicate that Topo-IIbeta is an interesting target for chemotherapy in ovarian tumours.

Adenocarcinoma↗
PubMed1999

Phase I and pharmacokinetic study of the topoisomerase II catalytic inhibitor fostriecin.

We conducted a phase I and pharmacokinetic study of the topoisomerase II catalytic inhibitor fostriecin. Fostriecin was administered intravenously over 60 min on days 1-5 at 4-week intervals. Dose was escalated from 2 mg m(-2) day(-1) to 20 mg m(-2) day(-1) in 20 patients. Drug pharmacokinetics was analysed with high performance liquid chromatography with UV-detection. Plasma collected during drug administration was tested in vitro for growth inhibition of a teniposide-resistant small-cell lung cancer (SCLC) cell line. The predominant toxicities were elevated liver transaminases (maximum common toxicity criteria (CTC) grade 4) and serum creatinine (maximum CTC grade 2). These showed only a limited increase with increasing doses, often recovered during drug administration and were fully reversible. Duration of elevated alanine-amino transferase (ALT) was dose-limiting in one patient at 20 mg m(-2). Other frequent toxicities were grade 1-2 nausea/vomiting, fever and mild fatigue. Mean fostriecin plasma half-life was 0.36 h (initial; 95% CI, 0-0.76 h) and 1.51 h (terminal; 95% CI, 0.41-2.61 h). A metabolite, most probably dephosphorylated fostriecin, was detected in plasma and urine. No tumour responses were observed, but the plasma concentrations reached in the patients were insufficient to induce significant growth inhibition in vitro. The maximum tolerated dose (MTD) has not been reached, because drug supply was stopped at the 20 mg m(-2) dose level. However, further escalation seems possible and is warranted to achieve potentially effective drug levels. Fostriecin has a short plasma half-life and longer duration of infusion should be considered.

Adult↗
PubMed1999

Effects of peripheral stem cell or bone marrow reinfusion on peripheral serotonin metabolism.

Reinfusion of autologous hematopoietic peripheral blood stem cells (PBSC) or bone marrow is often accompanied by flushing, dyspnea, abdominal cramping, nausea and diarrhea. These symptoms and the observation that they can be prevented by ondansetron, a selective 5-HT3 receptor antagonist, led to the assumption that these side-effects are due to infusion of free serotonin during the reinfusion of PBSC or bone marrow. Twenty-five patients with solid tumors received, after myeloblative chemotherapy, a total of 30 reinfusions of PBSC and/or bone marrow. In 17 patients, serotonin levels in the bags containing the PBSC were measured. In all patients, platelet serotonin levels were determined before and 1 h post-reinfusion. In addition, before and 24 h after reinfusion urine was collected for determination of 5-hydroxyindole acetic acid (5-HIAA) and serotonin concentrations. Mean (+/- s.d.) total serotonin concentration in the bags was 2404 +/- 1555 nmol/l. Mean total volume reinfused was 471 +/- 185 ml. After reinfusion, the mean (+/- s.d.) levels of serotonin in platelets in patients increased from 3.2 +/- 1.4 nm/10(9) at baseline to 3.8 +/- 2.0 nm/10(9) (P = 0.02). Neither 24 h urinary 5-HIAA nor serotonin levels were affected. These results indicate that reinfusion of PBSC or bone marrow is accompanied by substantial infusion of free serotonin, which might explain the observed side-effects and justify the use of 5-HT3 receptor antagonists as pre- medication for this procedure.

Adult↗
PubMed1999

Prevention of febrile leucopenia after chemotherapy in high-risk breast cancer patients: no significant difference between granulocyte-colony stimulating growth factor or ciprofloxacin plus amphotericin B.

In a prospective randomized trial, 40 stage IV breast cancer patients undergoing intermediate high-dose chemotherapy (cyclophosphamide, 5-fluorouracil plus epirubicin or methotrexate), received either recombinant human G-CSF (rhG-CSF, group I) or ciprofloxacin and amphotericin B (CAB, group II) for prevention of febrile leucopenia (FL). In group I, seven of 18 patients developed FL (after 10/108 courses); in group II, seven of 22 patients (7/98 courses) (P = NS). Median hospitalization duration and costs were not different. RhG-CSF was 6.6 times more expensive per course than CAB. In conclusion, prophylactic CAB has similar efficacy to rhG-CSF in this setting, and is more cost-effective.

Adult↗
PubMed1999

Combined cytotoxic effects of tumor necrosis factor-alpha with various cytotoxic agents in tumor cell lines that are drug resistant due to mutated p53.

Several studies suggest that tumor necrosis factor-alpha (TNF) is able to overcome drug resistance in tumors. Whether TNF is able to do so in tumor cell lines that are drug resistant due to a mutation in the tumor suppressor gene p53 is unclear. Therefore, we studied the in vitro cytotoxic effects of TNF combined with various cytotoxic agents in a model consisting of a human ovarian cancer cell line containing endogenous wild-type p53 (wtp53) and sublines that were made drug resistant against various cytotoxic agents by transfection of several forms of mutated p53 (mtp53). Using the microculture tetrazolium assay, the cytotoxic effects of TNF alone, the cytotoxic agents VM-26, melphalan, cisplatin, vinblastine, paclitaxel, and mitoxantrone, plus the combined effects of 10 ng/ml TNF added 30 min before various concentrations of the cytotoxic agents were established. Compared with the control cell line (A2780/cmv), two cell lines transfected with mtp53 (A2780/m248 and A2780/m273) showed increased resistance against several cytotoxic agents but also an enhanced sensitivity to TNF. Interaction of TNF with the cytotoxic drugs was additive in the drug-sensitive control cell line as well as in the drug-resistant sublines. However, because of the increased sensitivity of A2780/m248 to TNF at the dose used for the combinations, the combination of TNF with several cytotoxic drugs reduced the level of resistance in A2780/m248 compared with the control cell line A2780/cmv. In conclusion, this study shows that addition of TNF can ameliorate resistance to cytotoxic agents in a subline that is drug-resistant because of mutated p53. This reduction in resistance by TNF is not due to synergistic interaction, but to collateral sensitivity to TNF.

Antineoplastic Agents↗
PubMed1999

The modulatory impact of recombinant human interleukin-6 on the immune system of cancer patients.

To investigate the immunomodulatory impact of low-dose recombinant human interleukin-6 (rhIL-6), we examined 15 patients with metastatic renal cell carcinoma or malignant melanoma receiving rhIL-6 as an antitumor agent in a phase II trial. RhIL-6 (150 micrograms) was administered subcutaneously (s.c.) once daily for 42 consecutive days. Immunologic parameters were measured throughout therapy and at follow-up. No changes in white blood cell counts were noted. Lymphocyte subsets did not alter, nor did their expression of CD25 and HLA-DR. Immunoglobulins were unaffected. Levels of granulocyte-macrophage colony-stimulating factor, tumor necrosis factor-alpha and IL-1 beta remained below detection limits. Theoretically, subtle immunologic alterations might have been masked by increases in plasma volume, known to occur after start of therapy. Using previously published data concerning plasma volume changes in these patients, part of immunologic data were corrected for concurrent hemodilution, showing a 39% +/- 17% increase in monocytes (mean change +/- SEM [standard error of mean]; p < 0.03) within 1 week of therapy, while lymphocytes tended to increase. However, the absence of appreciable increases in cell activation markers and in monokine levels indicates insufficient immune activation, probably underlying the lack of objective antitumor responses (6 x stable, 9 x progressive disease) in these patients. In conclusion, the immunomodulatory impact of rhIL-6, if present at all, remains very limited.

Adolescent↗
PubMed1999

Early detection of anthracycline induced cardiotoxicity in asymptomatic patients with normal left ventricular systolic function: autonomic versus echocardiographic variables.

OBJECTIVE: To investigate left ventricular dysfunction in patients who had been treated with anthracycline based chemotherapy. METHODS: Autonomic function was compared with left ventricular diastolic function in 20 asymptomatic women with normal systolic function (left ventricular ejection fraction (LVEF) > 0.50) treated for breast cancer with high dose anthracycline based chemotherapy, and 20 age matched healthy controls. Left ventricular diastolic function was assessed echocardiographically by measuring the early peak flow velocity to atrial peak flow velocity ratio, isovolumic relaxation time, and deceleration time. Heart rate variability analysis was assessed for time domain and frequency domain parameters. RESULTS: The mean (SD) age of the patients was 45 (7) years and the mean LVEF was 0.59 (0.06). The time interval after the end of chemotherapy was 29 (27) months. One or more diastolic variables were abnormal in 50% of the patients. Heart rate variability was abnormal in 85% of patients. Mean values of both time domain and frequency domain parameters were decreased (p < 0.05), in particular the parasympathetic indices. CONCLUSIONS: Autonomic impairment occurs in a large proportion of asymptomatic patients with normal systolic left ventricular function after high dose anthracycline based chemotherapy. In particular, heart rate variability analysis may be a sensitive tool to identify the first signs of cardiotoxicity in these patients.

Adult↗
PubMed1999

Phase I study of transforming growth factor-beta3 mouthwashes for prevention of chemotherapy-induced mucositis.

The purpose of this study was to establish the safety and tolerability of recombinant transforming growth factor-beta3 (TGF-beta3; CGP 46614) mouthwashes intended for prevention of chemotherapy-induced mucositis. Local effects were especially analyzed by objective and subjective measurements of mucositis. Secondary aims were analysis of potential systemic exposure and development of anti-TGF-beta3-antibodies. Eleven breast cancer patients received chemotherapy with 1.5 g/m2 cyclophosphamide i.v., 80 mg/m2 epirubicin i.v., and 1.0 g/m2 5-fluorouracil i.v. (n = 8) or 1.6 g/m2 carboplatin i.v., 480 mg/m2 thiotepa i.v., and 6 g/m2 cyclophosphamide i.v. divided over 4 days (n = 3). TGF-beta3 mouthwashes (10 ml; provided by Novartis, Basel, Switzerland) were administered for 4 days, four times a day, starting 1 day before chemotherapy. The dose was escalated in following patients from 25 microg/ml (n = 3) to 50 microg/ml (n = 3) and 100 microg/ml (n = 5). Clinically, the mucosa was scored objectively and according to WHO criteria. The percentage of viable oral epithelial cells was determined by trypan blue dye exclusion. Morphology of cells was assessed in buccal smears. Plasma samples were collected for determination of TGF-beta3 levels and anti-TGF-beta3-antibodies. Adverse events were recorded by the patient in a diary. Mouthwashes with TGF-beta3 were well tolerated. Three patients scored for mucositis > grade 0 (WHO grading criteria). The percentage of viable oral epithelial cells in patients treated with 1.5 g/m2 cyclophosphamide i.v., 80 mg/m2 epirubicin i.v., and 1.0 g/m2 5-fluorouracil i.v. was stable, whereas in patients treated with 1.6 g/m2 carboplatin i.v., 480 mg/m2 thiotepa i.v., and 6 g/m2 cyclophosphamide i.v. divided over 4 days, an increase was observed. The morphology of buccal cells showed a transient shift from mature to immature cells in the first week. Neither systemic absorption of TGF-beta3 nor development of TGF-beta3-antibodies was observed. TGF-beta3 mouthwashes were well tolerated and deserve further study in preventing chemotherapy-induced mucositis.

Administration, Oral↗
PubMed1998

Enhanced sensitivity to tumor necrosis factor-alpha in doxorubicin-resistant tumor cell lines due to down-regulated c-erbB2.

We have studied the relationship between tumor necrosis factor (TNF)-sensitivity and doxorubicin-resistance in our doxorubicin-resistant cell line panel consisting of the parental cell line GLC4 plus GLC4-Adr2x and GLC4-Adr350x with respective resistance factors of 2 and 350 compared with GLC4. At the highest dose of 1000 ng/ml TNF, GLC4 was almost completely resistant to TNF, whereas 37% and 68% growth inhibition was observed in GLC4-Adr2x and GLC4-Adr350x, respectively. Sensitivity to TNF appeared to correlate inversely with the expression and gene copies of topoisomerase IIalpha in these cell lines. The gene encoding for c-erbB2 is in the proximity of the topoisomerase IIalpha gene and its product is a known cause for TNF-resistance. We found that our doxorubicin-resistant cell lines with decreased topoisomerase IIalpha gene copies have a simultaneous decrease in c-erbB2 gene copies, probably due to linkage between these 2 genes. This reduced number of c-erbB2 gene copies resulted in decreased c-erbB2 expression and subsequently in increased sensitivity to TNF. Additionally, we tried to establish some of the mechanisms associated with TNF-resistance in GLC4 related to c-erbB2 overexpression. There was no difference in TNF-receptor-1 expression between the cell lines. Compared with the TNF-sensitive GLC4-Adr350x, GLC4 appeared to have a decreased activation of NF-kappaB after exposure to TNF that might indicate a reduced TNF-receptor function. In GLC4, increased Bcl-2 expression was found, a protein described to confer TNF-resistance. Moreover, it was demonstrated that combining TNF with the poly-ADP-ribose polymerase (PARP) inhibitors 6-aminonicotinamide and 3-aminobenzamide did not affect TNF-sensitivity in GLC4 and GLC4-Adr350x, excluding a pivotal role of PARP in TNF-resistance in these cell lines. In conclusion, our data show that doxorubicin-resistant tumor cell lines with decreased topoisomerase IIalpha gene copies can become sensitive to TNF due to loss of c-erbB2 gene copies. We also found that several mechanisms associated with c-erbB2 overexpressing contribute to TNF-resistance in GLC4.

Antibiotics, Antineoplastic↗
PubMed1998

Transport of glutathione conjugates into secretory vesicles is mediated by the multidrug-resistance protein 1.

Intracellular glutathione-conjugate transport was evaluated in the human small cell lung carcinoma cell line GLC4 with low multidrug resistance protein (MRP1) expression and its 300x doxorubicin-resistant, MRP1-over-expressing, GLC4-Adr subline. Transport of non-toxic concentrations of monochlorobimane and 5-chloro-methyl fluorescein diacetate was evaluated using fluorescence microscopy. After exposure to these compounds, fluorescence was observed especially in intracellular vesicles in GLC4-Adr. Immunotransmission electron microscopy showed that MRP1 was present in the vesicle membranes and plasma membrane, while inside the vesicles the glutathione conjugate of 1-chloro-2,4-dinitrobenzene could be detected. Experiments with brefeldin A, which induces arrest in vesicle release from the Golgi complex, indicated that these vesicles may originate from the trans-Golgi network. In GLC4-Adr cells, doxorubicin also was transported in vesicles, with an arrest in vesicle release from the Golgi complex. Our results indicate that MRP1 functions as a glutathione-conjugate transporter not only at the plasma membrane but also in intracellular secretory vesicles.

ATP-Binding Cassette Transporters↗
PubMed1998

Induction of tumor necrosis factor-alpha as a cause of bleomycin-related toxicity.

BACKGROUND: The application of bleomycin is characterized by acute side effects, such as fever, chills, and sometimes hypotension and tachypnea. Furthermore, bleomycin is known to induce pneumonitis. There are several indications that the induction of cytokines by bleomycin is involved in the development of these side effects. METHODS: In this study, the authors determined the plasma levels of tumor necrosis factor-alpha (TNF-alpha), interleukin-1beta (IL-1beta), and transforming growth factor-beta (TGF-beta) before and after bleomycin infusion in 14 patients treated for disseminated nonseminomatous germ cell tumor. RESULTS: Compared with the pretreatment value, TNF-alpha was significantly increased 3, 4.5, and 24 hours after bleomycin infusion. For IL-1beta and TGF-beta, no significant alterations were observed within 24 hours after administration of bleomycin. CONCLUSIONS: The increase in TNF-alpha after administration of bleomycin suggests a role for this cytokine in the development of the acute side effects and probably also in the occurrence of bleomycin-induced pulmonary toxicity. The involvement of IL-1beta and TGF-beta deserve further study.

Adolescent↗
PubMed1998

Differential effects of all-trans-retinoic acid, docosahexaenoic acid, and hexadecylphosphocholine on cisplatin-induced cytotoxicity and apoptosis in a cisplantin-sensitive and resistant human embryonal carcinoma cell line.

Apart from modulation of tumor-cell drug sensitivity, induction of differentiation might be an alternative in the treatment of tumors resistant to cytotoxic drugs. In this report the capacity to induce differentiation and to modulate the cis-diamminedichloroplatinum(II) (CDDP) sensitivity of all-trans-retinoic acid (RA), docosahexaenoic acid (DCHA), and hexadecylphosphocholine (HePC) is examined in human germ-cell tumor cell lines. In the embryonal carcinoma cell line Tera-2 and its 3.7-fold CDDP-resistant subline Tera2-CP, we evaluated the effects of 96 h of pretreatment with RA (0.1 microM), DCHA (23 microM), and HePC (25 microM) on differentiation induction and on CDDP-induced cytotoxicity, DNA platination (4-h incubation), and apoptosis (continuous incubation). Without drug treatment, Tera2-CP showed less apoptosis than Tera-2. Pretreatment with RA decreased the cytotoxicity and apoptosis induced by CDDP without resulting in decreased DNA platination and increased differentiation in both cell lines. DCHA enhanced CDDP-induced cytotoxicity and apoptosis and did not affect the embryonal character of either cell line. HePC did not affect CDDP cytotoxicity or differentiation in either cell lines. Effects of the modulators on differentiation and on CDDP-induced cytotoxicity, DNA platination, and apoptosis did not differ between Tera-2 and Tera2-CP. RA can be applied for differentiation induction in CDDP-resistant germ-cell tumor models. However, in this model, RA reduced the apoptotic susceptibility. DCHA potentiated CDDP cytotoxicity in vitro; its in vivo modulatory capacity in germ-cell tumor cells deserves further study.

Apoptosis↗
PubMed1998

Renal toxicity of the anticancer drug fostriecin.

PURPOSE: Fostriecin is an inhibitor of topoisomerase II catalytic activity. In a phase I trial we observed renal toxicity, documented as a rise in serum creatinine, which was reversible and non-dose-limiting. The purpose of this study was a detailed analysis of this toxicity. METHODS: A total of 20 patients received fostriecin as a 1-h i.v. infusion daily x 5 at doses ranging from 2 to 20 mg/m2 per day. Serum creatinine determination and urinalysis were performed daily during drug administration. Renal hemodynamics were measured by means of clearance studies using 125I-iothalamate and (131)I-hippuran in eight patients at doses of > or =4 mg/m2 per day at baseline, on day 3 or 4 during the first course, and 3 weeks after the second course. RESULTS: The rise in serum creatinine was maximal after one to two doses despite continued administration. This increase showed no correlation with the dose level at fostriecin doses of > or =4 mg/m2 per day. Urinary beta2-microglobulin concentrations increased 150-fold (median), which is compatible with impaired tubular reabsorption. The median change in the glomerular filtration rate (GFR) was -36% (range -28% to -44%), that in effective renal plasma flow (ERPF) was -23% (range -11% to -36%), and the filtration fraction (FF) decreased in all patients during the first course of treatment. The values measured 3 weeks after the second course, however, did not differ from baseline. CONCLUSIONS: Fostriecin induces reversible renal hemodynamic changes compatible with renal tubular damage.

Adult↗