Nanno Mulder

Infection prevention in granulocytopenic patients by selective decontamination of the digestive tract

In a controlled prospective randomized trial we studied the effect of selective decontamination of the digestive tract (SDD) in granulocytopenic patients on the frequency of infections. By SDD it was aimed to suppress the pathogenic Gramnegative micro-organisms and yeasts without affecting the non-pathogenic anaerobic flora. This anaerobic flora was maintained intact because of its value for the colonization resistance of the gastrointestinal tract. n nSDD was accomplished by oral administration of nalidixic acid or co-trimoxazole or polymyxin E to suppress growth of aerobic Gram-negative bacteria, and amphotericin-B to inhibit growth of yeasts. n nGram-negative or yeast infections occurred in the control group 18 times in 12 patients; in the decontaminated group two times in two patients (P < 0.01). Clinical infections occurred 15 times in 12 control patients and four times in three SDD treated patients (0.01 < P < 0.05). While nine patients in the control group died with an acquired infection none died in the SDD treated group (P < 0.01). n nIt is concluded that SDD is a promising and widely applicable method of infection prevention. It decreases the need for treatment in a ‘protected environment’.

Improved long term survival of patients with metastatic nonseminomatous testicular germ cell carcinoma in relation to prognostic classification systems during the cisplatin era

The current study reviews chronologic changes in the long term outcome of patients with metastatic nonseminomatous testicular germ cell tumors (NSTGCT) who were treated at a single institution during the past two decades. The 10‐year survival of prognostic subgroups according to the classification of the International Germ Cell Consensus Classification Group (IGCCCG) and various other prognostic classifications is examined in time to evaluate whether cumulative experience has led to an improved outcome of patients with metastatic NSTGCT and to explore differences in outcome of prognostic subgroups.

[11C]FMAU and [18F]FHPG as PET tracers for herpes simplex virus thymidine kinase enzyme activity and human cytomegalovirus infections

[(11)C]-2-Fluoro-5-methyl-1-beta-D-arabinofuranosyluracil ([(11)C]FMAU) and [(18)F]-9-[(3-fluoro-1-hydroxy-2-propoxy)methyl]guanine ([(18)F]FHPG), radiolabeled representatives of two classes of antiviral agents, were evaluated as tracers for measuring herpes simplex virus thymidine kinase (HSV-tk) enzyme activity after gene transfer and as tracers for localization of active human cytomegalovirus (HCMV) infections. In vitro accumulation experiments revealed that both [(11)C]FMAU and [(18)F]FHPG accumulated significantly more in HSV-tk expressing cells than they did in control cells. [(18)F]FHPG uptake in HSV-tk expressing cells, however, was found to depend strongly on the cell line used, which might be due to cell type dependent membrane transport or cell type dependent substrate specific susceptibility of the enzyme. In vitro, both tracers exhibited a good selectivity for accumulation in HCMV-infected human umbilical vein endothelial cells over uninfected cells. In contrast to [(18)F]FHPG, [(11)C]FMAU uptake in control cells was relatively high due to phosphorylation of the tracer by host kinases. Therefore, [(18)F]FHPG appears to be the more selective tracer not only to predict HSV-tk gene therapy outcome, but also to localize active HCMV infections with PET.

Carbon-11 labelled tyrosine to study tumor metabolism by positron emission tomography (PET)

To measure the rate of protein synthesis in human neoplasms by positron emission tomography, we prepared no carrier added DL-(1-11C)-tyrosine by 11C-carboxylation of the appropriate α-lithioisocyanide followed by hydrolysis of the isocyanide function and removal of the protecting methoxy group. The purification, resolution and solvent switch to saline was performed by high performance liquid chromatography (HPLC). DL-(1-11C)-Tyrosine in 0.1 N NaH2PO4 buffer was prepared with a radiochemical yield of 8%–16% (EOS, 35 min). The enantiomeric separation and solvent switch to saline were achieved in 5 min and 10 min respectively. Consequently L-(1-11C)-tyrosine in physiological saline was obtained in 2%–4% radiochemical yield. Tumor accumulation in rats with the experimental WALKER 256 carcinosarcoma was observed for both the L- and D-isomer. Using positron emission tomography a tumor/muscle ratio of two was observed for the L-isomer 15 min after injection. The corresponding figure for the D-isomer was 2.5. The first clinical results with DL-(1-11C)-tyrosine show accumulation of radioactivity in meningioma, a primary breast carcinoma and in liver metastases of a colonic carcinoma.

Intraperitoneal human recombinant interferon alpha-2b in minimal residual ovarian cancer.

Twenty evaluable patients with minimal residual ovarian cancer at second look laparotomy were treated with human recombinant interferon alpha-2b (IFN) intraperitoneally. The dose administered was 50 x 10(6) units once weekly for 8 weeks. Seventeen patients were evaluated by a relaparotomy: five had a pathological complete remission, four a partial response, six patients disease stabilization and two patients had progression. Three patients, two stable and one with clinical progression, had no laparotomy. Nine of the 11 patients with residual tumor smaller than 5 mm had a response, while no response was found in six patients with residuals over 5 mm. The median duration of CR is 11+ months (6-13+ months) after evaluation. For toxicity, 156 treatment cycles could be studied. Fever was seen in 80% of all cycles within 24 h following administration of IFN, in 58 cycles (37%) over 38 degrees C and in 65 cycles (43%) over 39 degrees C. Abdominal pain was slight in 32% and moderate in 3% of all cycles. The peripheral blood leukocyte counts dropped after 52% of all cycles, in 27% below 4.0, in 22% below 3.0, and in one patient below 2.0 x 10(9)/l. IFN dosage was not reduced for leukopenia, but in one patient reduction was necessary for thrombopenia, resulting from insufficient marrow reserve after a previous autologous bone marrow transfusion. Pharmacokinetic studies showed i.p. IFN levels 50-100 times the blood levels. Blood levels were still elevated 2 days after i.p. infusion, but normalized within 1 week on repeated administration. At the second instillation, lower peak serum levels were reached. In conclusion, high doses of i.p. IFN appear to be active in patients with minimal residual disease, with ongoing response in CR patients. Apart from general malaise on the day of treatment, toxicity was acceptable. IFN may be active in patients with minimal residual ovarian cancer through local as well as systemic effects.

ACUTE NONLYMPHOCYTIC LEUKEMIA 5 YEARS AFTER TREATMENT WITH CISPLATIN, VINBLASTINE, AND BLEOMYCIN FOR DISSEMINATED TESTICULAR CANCER

The combination of cisplatin, vinblastine, and bleomycin (PVB) was used to treat a 25‐year‐old man for disseminated testicular germ cell cancer, leading to a complete remission. Acute nonlymphocytic leukemia (ANLL), resistant to chemotherapy, developed 5 years later. The secondary nature of this ANLL was corroborated by the detection of nonrandom chromosomal aberrations in bone marrow cells of chromosomes, 7, 5, and 3. This is one of the first reports of possible leukemogenic activity of PVB treatment when applied without additional irradiation or alkylating agents.

THE INFLUENCE OF L-ASPARAGINASE THERAPY ON THE FIBRINOLYTIC SYSTEM

Summary. Fibrinolytic factors were assessed during L‐asparaginase administration, to study whether their changes may predispose to a haemorrhagic or thrombotic diathesis. The total level of α2‐antiplasmin declined, as well as the ratio of the plasminogen‐binding form of α2‐antiplasmin to the non‐plasminogen‐binding form. After cessation of L‐asparaginase administration, the ratio increased to 1.6 times that of the pretreatment value. These data indicate that the plasminogen‐binding form of α2‐antiplasmin is the form primarily synthesized in vivo. L‐Asparaginase therapy reduced plasma levels of plasminogen and histidine‐rich glycoprotein (HRG) and influenced the equilibrium between HRG, plasminogen and HRG‐plasminogen complex, with a more pronounced decrease of plasminogen (62%±8) and HRG (76%±11) in comparison to the free‐plasminogen levels (51%±6). α2‐Macroglobulin was only slightly influenced by L‐asparaginase and may consequently play a more pronounced role in inhibition. This is suggested by moderate declines in functional tests of plasmin, urokinase and tissue activator inhibition by patients plasma, and by the ratio of inhibition of these enzymes over α2‐antiplasmin. Thus the bleeding tendency described during L‐asparaginase therapy can be ascribed not only to a temporary deficiency of coagulation factors but also to temporary α2‐antiplasmin deficiency.

Hyperthermic potentiation of cisplatin toxicity in a human small cell lung carcinoma cell line and a cisplatin resistant subline

A human small cell lung carcinoma cell line (GLC4) and its subline with in vitro acquired cisplatin (cDDP) resistance (GLC4-cDDP) were used to study the applicability of hyperthermia to interfere with acquired cDDP resistance. GLC4 and GLC4-cDDP did not differ in heat sensitivity (clonogenic ability). Both cell lines could be sensitized to cisplatin to a considerable extent, both at 42 and 43 degrees C. For 42 degrees C hyperthermia treatments up to 90 min no differences in TER between the cell lines were observed. Only prolonged (> or = 45 min) exposures to 43 degrees C hyperthermia sensitized the resistant cell line to a greater extent than the parent cell line, resulting in a reduction of the resistance factor from 3.6 (at 37 degrees C) to 1.7 (60 min 43 degrees C). The finding in this human system that for treatments up to 90 min, 43 degrees C heat is more suitable than 42 degrees C heat to reduce cDDP resistance, is in accordance with earlier findings with murine cells (Konings et al. 1993). Effects of heat, cisplatin and combined treatments on cell killing were not only measured with the clonogenic assay, but also with the microculture tetrazolium method (MTT assay), an assay of potential use in the clinic for rapid screening of cells obtained from patients. The data with the latter assay were comparable to those obtained with the clonogenic assay. However, its applicability to measure thermo-chemosensitization is limited due to its inability to measure more than one log of cell killing.

Evaluation of [18F]FHPG as PET tracer for HSVtk gene expression

In rats, the relationship between [(18)F]FHPG accumulation and HSVtk expression was studied with PET and autoradiography. [(18)F]FHPG distribution closely corresponded with HSVtk immunohistochemical staining. ROI analysis of tracer uptake 2 hours p.i. and Patlak graphical analysis were applied to quantify the PET data. For both analysis methods, the [(18)F]FHPG PET signal correlated well with the fraction of HSVtk expressing cells implanted, but showed a plateau when plotted against HSVtk protein levels. This might be due to rate limiting [(18)F]FHPG membrane transport.

Disparities in survival of stomach cancer among different socioeconomic groups in North-East Netherlands

BACKGROUNDnSurvival differences in stomach cancer are depended on patient, tumour and treatment factors. Some populations are more prone to develop stomach cancer, such as people with low socioeconomic status (SES). The aim of this population based study was to assess whether differences in socioeconomic status (SES) alone, after adjusting for confounding factors, also influence survival.nnnMETHODSnFrom 1989 to 2007 all patients with stomach cancer were selected from the cancer registry of the Comprehensive Cancer Centre North-East. Postal code at diagnosis was used to determine SES, dividing patients in three groups; low, intermediate and high SES. Associations between age, localization, grade, stage, and treatment were determined using Chi-square analysis. Relative survival analysis was used to estimate relative excess risk (RER) of dying according to SES.nnnRESULTSnIn low SES neighbourhoods diagnosis was established at older age. More distal tumours were detected in patients with low SES, whereas pathology showed more poorly differentiated tumours in patients with high SES. Overall, more resections were performed in, and more chemotherapy was administrated to patients in high SES neighbourhoods. After adjusting for confounding factors, the risk of dying was lower for patients with high SES (RER 0.89, 95% Confidence Interval 0.81-0.98) compared to patients with low SES.nnnCONCLUSIONnSES proved to be an independent prognostic factor for survival in patients with stomach cancer.