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A recently developed multiple fibre system for treating malignant tumours with interstitial photodynamic therapy was used in studies on rats with colon adenocarcinoma inoculated into the muscles of the hind legs. The animals were intraperitonially administrated delta -aminolevulinic acid (ALA), which is metabolised to protoporphyrin IX (PpIX) in the tissue. The treatment system consists of a laser light source, a beam-splitting system dividing the light into three or six output fibres and a dosimetry programme calculating the optimal fibre position within the tumour as well as the treatment time needed to obtain a given threshold value of the light dose. One aim of the study was to compare the treatment outcome with the modelled dosimetry predictions. Tumour reduction was examined three days post treatment. A volume decrease was found in 85\% of the treated tumours. The mean volume reduction was 44\%, with one tumour completely disappearing. Histopathological examination three days post treatment showed substantial necrotic parts which, however, to a smaller extent were present also for non-treated tumours. These results indicated that the tumours have been under treated and the light dose has to be increased. Measurements of the build-up and photo-induced bleaching of PpIX using laser-induced fluorescence were also performed during the experiments. (Less)

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AIM: To assess liver fibrosis (LF) in hepatitis C virus (HCV) and alcoholic liver disease (ALD), estimate health outcomes and costs of new noninvasive testing strategies. METHODS: A Markov model was developed to simulate LF progression in HCV and ALD for a cohort of 40-year-old men with abnormal levels of transaminases. Three different testing alternatives were studied: a single liver biopsy; annual Enhanced liver fibrosis (ELF ) followed by liver stiffness measurement (LSM) imaging as a confirmation test if the ELF test is positive; and annual ELF test without LSM. The analysis was performed from the perspective of a university hospital in Spain. Clinical data were obtained from published literature. Costs were sourced from administrative databases of the hospital. Deterministic and probabilistic sensitivity analyses were performed RESULTS: In HCV patients, annual sequential ELF test/LSM and annual ELF test alone prevented respectively 12.9 and 13.3 liver fibrosis-related deaths per 100 persons tested, compared to biopsy. The incremental cost-effectiveness ratios (ICERs) were respectively 13400 and 11500 per quality-adjusted life year (QALY). In ALD, fibrosis-related deaths decreased by 11.7 and 22.1 per 100 persons tested respectively with sequential ELF test/LSM and annual ELF test alone. ICERs were 280 and 190 per QALY, respectively. CONCLUSION: The use of the ELF test with or without a confirmation LSM are cost-effective options compared to a single liver biopsy for testing liver fibrosis in HCV and ALD patients in Spain.

A number of papers .nd that changes in schooling are not correlated with changes in per capita income. Two non-competing interpretations that have been given are that the social return on schooling is close to zero and the measurement error of changes in schooling is high. This paper shows that the lack of significance of schooling is threefold. First, there is a problem of a proper definition of the way in which years of schooling should enter in a production function. Second, collinearity between physical and human capital stocks seriously undermines the ability of educational indicators to display any significance in panel data estimates. And third, failure to cope with measurement error and endogeneity produces biased estimates. As opposed to the earlier empirical literature, the social return of schooling is positive and significant, but no Lucas-type externalities are observed.