Biomedical subjects

W Landuyt

Publications and source records attributed to W Landuyt.

57 records · Page 4Linked to original sources

PubMed1984

Differences in repopulation kinetics in mouse skin during split course multiple fractions per day (MFD) or daily fractionated irradiations.

The influence of protraction and distribution of irradiation as a function of time on the repopulation kinetics of mouse skin have been evaluated. Twenty fractions have been given either daily for 5 days per week during 4 weeks, or thrice a day to 10 irradiations in 3 days, repeated after a rest period of 19 days, resulting also in an overall time of 4 weeks. The acute skin reaction was scored. It was found that the split course multiple fractions per day (MFD) schedule induced less skin reaction than continuous daily fractionation, which was mainly attributable to recovery of skin damage during the rest period. Therefore, it can be postulated that the repopulation of the surviving clonogenic epidermal cells is less efficient during continuous daily irradiation than during split course MFD schedule given in the same overall treatment time.

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PubMedDate not supplied

Increasing specificity of anti-tumor therapy: cytotoxic protein delivery by non-pathogenic clostridia under regulation of radio-induced promoters.

BACKGROUND: Pathogenic clostridia, genetically engineered to express therapeutic genes, will specifically target hypoxic regions in tumors. This specificity can be further improved if expression of these genes is controlled by a radio-induced promoter, leading to spatial and temporal control of gene expression. MATERIALS AND METHODS: Following administration of Clostridium spores to tumor bearing rats, normal tissue and tumoral specimens were compared for colonization. Clostridium was genetically modified to express tumor necrosis factor a or cytosine deaminase. Expression of these proteins was assayed. Northern blot hybridizations were used to detect genes which are radio-induced. RESULTS: Clostridium gave a selective colonization of tumors. The recombinant clostridia expressed in vitro and in vivo TNF alpha and cytosine deaminase. Clostridial SOS-repair genes were induced at a dose of 2 Gy. CONCLUSIONS: Pathogenic Clostridium can be used for tumor specific delivery of therapeutic genes. The specificity can be improved via radio-induced promoters. Overall, this new gene delivery system can lead to an increase of the therapeutic ratio in cancer treatment.

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PubMedDate not supplied

In vivo antitumour effect of combretastatin A-4 phosphate added to fractionated irradiation.

BACKGROUND: The study aimed at evaluating the potential benefit from a combination of fractionated ionising radiation with the vascular-targeting compound combretastatin A-4 phosphate (CA-4-P). MATERIALS AND METHODS: Syngenic rat rhabdomyosarcoma (R1), growing subcutaneously, was treated at 2 different sizes: either small (2 +/- 0.5 cm3) or large (10.94 +/- 0.6 cm3). Localised fractionated irradiation of the tumours (5 x 3 Gy) in 5 days was followed 1 day later by an intraperitoneal CA-4-P treatment (25 mglkg). RESULTS: The combined treatment of only large tumours resulted in a small additional growth delay when compared with radiotherapy only. CONCLUSION: The present data indicate a size-dependent increase in tumour growth delay from combining fractionated irradiation with CA-4-P.

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