Atherosclerosis risk factors in young patients formerly treated for idiopathic nephrotic syndrome

A total of 30 patients (ten female/20 male), 9 years to 22 years old (mean age 17.3 years) and 30 healthy teenage controls (mean age 16.4 years) were included in our study. The patients had steroid-sensitive idiopathic nephrotic syndrome (INS) and had completed steroid therapy 4 years to 15 years ago. Height and weight, body mass index (BMI), body composition, and intima-media thickness (IMT) were determined, as were levels of total cholesterol (TCh), low-density lipoprotein cholesterol (LDL-Ch), high-density lipoprotein cholesterol (HDL-Ch), triacylglycerols (TAGs), homocysteine (HCY), and high-sensitivity C-reactive protein (hsCRP). We did not observe any differences between the study and control groups in IMT (0.47 +/- 0.1 vs 0.46 +/- 0.1 mm) and body composition (fat tissue and water content). Differences in HDL-Ch and hsCRP levels between groups were not significant. In the study group we found significantly higher TCh levels (187.6 +/- 57.2 mg/dl vs 158.8 +/- 25.7 mg/dl; P = 0.012), LDL-Ch (115.9 +/- 63.7 mg/dl vs 79.4 +/- 25.4 mg/dl; P = 0.005), HCY (12.3 +/- 7.7 micromol/l vs 7.6 +/- 1.6 micromol/dl; P < 0.001), apolipoprotein B (ApoB) (113.6 +/- 30.0 mg/dl vs 78.7 +/- 13.6 mg/dl; P < 0.001) and ApoA1 (203.5 +/- 50.8 mg/dl vs 156.5 +/- 12.4 mg/dl; P < 0.001) levels. Multi-factor analysis of the influence of independent factors (number of recurrences, duration of remission, age, gender, and BMI) on the parameters under investigation indicated a positive correlation between IMT and the number of recurrences.

CONCLUSIONS

1. Patients treated for idiopathic nephrotic syndrome in the past should undergo regular laboratory tests of atherosclerosis risk factors, including not only cholesterol and its fractions, but also ApoA1, ApoB and HCY. 2. It is necessary to continue systematic check-ups of the intima-media thickness of the carotid arteries among young patients with anamnesis of INS, especially among patients who suffered from numerous relapses of this disease.

An international dosimetry exchange for BNCT part II: computational dosimetry normalizations

The meaningful sharing and combining of clinical results from different centers in the world performing boron neutron capture therapy (BNCT) requires improved precision in dose specification between programs. To this end absorbed dose normalizations were performed for the European clinical centers at the Joint Research Centre of the European Commission, Petten (The Netherlands), Nuclear Research Institute, Rez (Czech Republic), VTT, Espoo (Finland), and Studsvik, Nyköping (Sweden). Each European group prepared a treatment plan calculation that was bench-marked against Massachusetts Institute of Technology (MIT) dosimetry performed in a large, water-filled phantom to uniformly evaluate dose specifications with an estimated precision of +/-2%-3%. These normalizations were compared with those derived from an earlier exchange between Brookhaven National Laboratory (BNL) and MIT in the USA. Neglecting the uncertainties related to biological weighting factors, large variations between calculated and measured dose are apparent that depend upon the 10B uptake in tissue. Assuming a boron concentration of 15 microg g(-1) in normal tissue, differences in the evaluated maximum dose to brain for the same nominal specification of 10 Gy(w) at the different facilities range between 7.6 and 13.2 Gy(w) in the trials using boronophenylalanine (BPA) as the boron delivery compound and between 8.9 and 11.1 Gy(w) in the two boron sulfhydryl (BSH) studies. Most notably, the value for the same specified dose of 10 Gy(w) determined at the different participating centers using BPA is significantly higher than at BNL by 32% (MIT), 43% (VTT), 49% (JRC), and 74% (Studsvik). Conversion of dose specification is now possible between all active participants and should be incorporated into future multi-center patient analyses.

Smoking and prognostic factors in advanced non-small cell lung cancer (NSCLC)

18048

Background: The aim of this prospective, multi-country, observational study (B9E-AA-B004) is to estimate the effect of prognostic factors, including continued smoking during therapy, on treatment outcomes in patients (pts) with advanced NSCLC receiving first- line chemotherapy with a gemcitabine (gem)-platinum combination as part of their routine care. Methods: Major eligibility criteria included: tissue diagnosis of advanced stage IIIB/IV NSCLC not amenable to curative surgery/radiotherapy; no prior chemotherapy; ECOG performance status (PS) 0 or 1; and written informed consent. A predictive model was constructed and validated by splitting the data at random by centre into two datasets in a ratio of 3:1 Construction:Validation. The primary and secondary endpoints are the effect of prognostic factors on survival and selected adverse events (AEs), respectively. The association of smoking with outcomes was tested in the Construction dataset. Results: This interim analysis to assess the effect of prognostic factors on AEs occurred when all pts had completed treatment. 1214 pts were enrolled: 75.1% male; mean age 60.5 yr, range 23–86 yr; 57.1% Stage IV; 66.2% PS 1; 69.4% received gem-cis, 30.5% gem-carb; 25.7% had never smoked, 70.8% had ever smoked and 11.2% continued smoking during therapy. 22.0% of pts had =1 AE. After variable selection in the Construction database (891 pts) the following factors were associated with an AE possibly related to therapy: disease stage (IV vs III, odds ratio (OR) =1.48, p=0.034), weight loss >10% (OR=0.60, p=0.017), age (<70 vs =70, OR=0.66, p=0.046), treatment (gem- carb vs gem-cis, OR=1.5, p=0.04), pain at baseline (present vs absent, OR=1.5, p=0.03), country (OR vs Taiwan ranged from 0.32 (Israel) to 4.2 (Egypt), p<0.0001). Sex (F vs M, OR=0.86) was then added to the model because of its clinical importance. There was a trend towards a higher probability of an AE with continued smoking during therapy (OR=1.4), but this was not statistically significant (p=0.28). Conclusions: This model can be used to improve the prediction of whether patients are likely to experience treatment-related AEs. While the trend was for a greater AE rate in pts who continued to smoke during therapy, this was not proven.

[Table: see text]

An international dosimetry exchange for boron neutron capture therapy. Part I: Absorbed dose measurements

An international collaboration was organized to undertake a dosimetry exchange to enable the future combination of clinical data from different centers conducting neutron capture therapy trials. As a first step (Part I) the dosimetry group from the Americas, represented by MIT, visited the clinical centers at Studsvik (Sweden), VTT Espoo (Finland), and the Nuclear Research Institute (NRI) at Rez (Czech Republic). A combined VTT/NRI group reciprocated with a visit to MIT. Each participant performed a series of dosimetry measurements under equivalent irradiation conditions using methods appropriate to their clinical protocols. This entailed in-air measurements and dose versus depth measurements in a large water phantom. Thermal neutron flux as well as fast neutron and photon absorbed dose rates were measured. Satisfactory agreement in determining absorbed dose within the experimental uncertainties was obtained between the different groups although the measurement uncertainties are large, ranging between 3% and 30% depending upon the dose component and the depth of measurement. To improve the precision in the specification of absorbed dose amongst the participants, the individually measured dose components were normalized to the results from a single method. Assuming a boron concentration of 15 microg g(-1) that is typical of concentrations realized clinically with the boron delivery compound boronophenylalanine-fructose, systematic discrepancies in the specification of the total biologically weighted dose of up to 10% were apparent between the different groups. The results from these measurements will be used in future to normalize treatment plan calculations between the different clinical dosimetry protocols as Part II of this study.

Polyomavirus EGFP-pseudocapsids: Analysis of model particles for introduction of proteins and peptides into mammalian cells

A vector for preparation of mouse polyomavirus capsid-like particles for transfer of foreign peptides or proteins into cells was constructed. Model pseudocapsids carrying EGFP fused with the C-terminal part of the VP3 minor protein (EGFP-VLPs) have been prepared and analysed for their ability to be internalised and processed by mouse cells and to activate mouse and human dendritic cells (DC) in vitro. EGFP-VLPs entered mouse epithelial cells, fibroblasts and human and mouse DC efficiently and were processed by both, lysosomes and proteasomes. Surprisingly, they did not induce upregulation of DC co-stimulation molecules or maturation markers in vitro; however, they did induce interleukin 12 secretion.

Progress with the NCT international dosimetry exchange

The international collaboration that was organized to undertake a dosimetry exchange for purposes of combining clinical data from different facilities conducting neutron capture therapy has continued since its founding at the 9th ISNCT symposium in October 2000. The thrust towards accumulating physical dosimetry data for comparison between different participants has broadened to include facilities in Japan and the determination of spectral descriptions of different beams. Retrospective analysis of patient data from the Brookhaven Medical Research Reactor is also being considered for incorporation into this study to increase the pool of available data. Meanwhile the next essential phase of comparing measurements of visiting dosimetry groups with treatment plan calculations from the host institutes has commenced. Host centers from Petten, Finland and the Czech Republic in Europe and MIT in the USA have applied the regular calculations and clinical calibrations from their current clinical studies, to generate treatment plans in the large standard phantom used for measurements by visiting participants. These data have been exchanged between the participants and scaling factors to relate the separate dose components between the different institutes are being determined. Preliminary normalization of measured and calculated dosimetry for patients is nearing completion to enable the physical radiation doses that comprise a treatment prescription at a host institute to be directly related to the corresponding measured doses of a visiting group. This should serve as an impetus for the direct comparison of patient data although the clinical requirements for achieving this need to be clearly defined. This may necessitate more extensive comparisons of treatment planning calculations through the solution of test problems and clarification regarding the question of dose specification from treatment calculations in general.

The mechanism of corrosion of palladium–silver binary alloys in artificial saliva

Palladium dental casting alloys are alternatives to gold alloys. The aim of this study was to determine the electrochemical behaviour and the corrosion mechanism of binary silver-palladium alloys. Seven binary silver-palladium alloys and pure palladium and silver were tested in a model saliva solution. Electrochemical tests included corrosion potential, polarization resistance, and potentiodynamic polarization measurements. The corrosion products, which may be theoretically formed, were determined by thermodynamic calculation. The behaviour of silver and silver-rich alloys was dominated by the preferential formation of a thiocyanate surface layer, which controlled the free corrosion potential. Palladium dissolved in the form of a thiocyanate complex, but the surface became passivated by either palladium oxide or solid palladium thiocyanate layer, the thermodynamic calculations indicating preference for the oxide. Palladium-rich alloys showed evidence of silver depletion of the surface, resulting in behaviour similar to palladium. Examination of binary silver-palladium alloys has made possible determination of the role of the components of the alloys and model saliva in the corrosion behaviour. The findings are applicable to the more complex commercial dental alloys containing silver and palladium as major components.

Spatial characterization of BNCT beams

The space distribution of the epithermal neutron flux was determined for the epithermal neutron beams of several NCT facilities in USA (FCB at MIT), Europe (HFR at JRC, Petten; FiR at VTT, Espoo; LVR-15 at NRI, Rez) and Japan (JRR-4 at JAERI, Tokai). Using p-n diodes with (6)Li radiator and the set of Bonner sphere spectrometer (BSS) the beams were quantified in-air. Axial beam profiles along the beam axes and the radial distributions at two distances from the beam aperture were measured. Except for the well-collimated HFR beam, the spatial characteristics of the other studied beams were found generally similar, which results from their similar designs.

Development of equipments for determination of BNCT source spectral parameters

The knowledge of neutron and gamma ray energy spectra can strongly influence the BNCT information about delivered dose to target volume as well as to the surface healthy tissue region. This region is very often decisive to stay within the recommended healthy tissue limit. Modification of neutron Bonner spectrometer to one block i.e. Bonner spectrometer monoblock (BSM) and gamma ray Si semiconductor spectrometer are being developed and verified in real conditions of LVR-15 reactor beam. Test measurements were also carried out in conditions of known standard spectra. The accepted procedure and the first results documenting the sensitivity BSM to different spectra are presented.

[Neutron capture therapy in the treatment of glioblastoma multiforme. Initial experience in the Czech Republic]

BACKGROUND

Glioblastoma multiforme is the most frequent primary brain tumor in adults. Despite advances in surgery, radiotherapy and chemotherapy, its treatment remains unsatisfactory with very limited overall survival. In the year 2001, in cooperation with Department of Neurosurgery, Nemocnice Na Homolce and Nuclear Research Institute in Rez, we have started to treat glioblastoma patients with boron neutron capture therapy (BNCT).

METHODS AND RESULTS

Cells of malignant brain tumors, especially that of glioblastomas, are able to accumulate boron compounds. If BNCT should be successful, it is necessary to reach selective accumulation of sufficient amount of 10B in the tumor and low accumulation in the normal brain tissue. After BSH administration, radiation with low energy thermal neutrons is delivered. It results in nuclear capture and fission reactions with subsequent selective damage of tumor cells. At the time of analysis 9 patients have been enrolled. Therapy was completed in 5 patients. Treatment has been very well tolerated. We observed minimal acute toxicity associated with radiation and no laboratory abnormalities after administrations of BSH. Unfortunately treatment results were quite unsatisfactory. The median time to progression and overall survival were shorter then expected with conventional treatment.

CONCLUSIONS

BNCT is very well tolerated with only a modest toxicity. In contrast to standard radiation, BNCT patients receive only one dose of radiation. Nevertheless, in this small pilot study first results were inferior when compared either to outcomes of conventional therapy or to results reported from other BNCT groups. It might be explained that lower dose of radiation had been used. Further study will show whether the higher dose radiation can improve treatment results.