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•X-ray imaging is widely applied for Cultural Heritage thanks to the non-invasive approach.•Micro-computed tomography was carried out on two ancient Egyptian woodden statuette.•A comparison between the results obtained on the two objects were performed.•Information on the artistic technique and state of conservation was obtained.•Differences and similarities in technical features of the statuettes were discovered.

We used the oxygen sensitivity of the histochemical reaction to detect glucose-6-phosphate dehydrogenase (G6PDH) activity based on neotetrazolium (NT) reduction to discriminate cancer cells from normal cells. Formazan generation was strongly reduced in normal but not in malignant cells when the incubation was performed in oxygen instead of nitrogen. Competition for reductive equivalents between NT and oxygen via superoxide dismutase (SOD) has been suggested. Since SOD activity is usually decreased in cancer cells, NT reduction would not be hampered in these cells. We tested this hypothesis by demonstrating NAD-dependent lactate dehydrogenase (LDH) activity instead of NADP-dependent G6PDH activity in normal rat liver and colon, in human colon carcinoma, and in experimentally induced metastases of colon carcinoma in rat livers. Reactions for both enzymes were determined cytophotometrically in an atmosphere of pure oxygen or nitrogen. G6PDH acted as described previously, showing distinct activity in cancer cells but strongly reduced activity in normal cells after incubation in oxygen, but this was not the case with LDH because formazan was also generated in normal tissue in oxygen. It appeared that after 5 min of incubation at 37 degrees C the residual activity of G6PDH in an atmosphere of oxygen compared with nitrogen was 0% in normal liver tissue and 15% in normal colon epithelium, whereas in colon carcinoma and in colon carcinoma metastasis in liver it was 48% and 33%, respectively. The residual activity of LDH in oxygen was 30% in normal female rat liver, 75% in normal male rat liver, and 38% in normal colon epithelium, whereas the residual activity in colon carcinoma and metastases in liver was 54% and 24%, respectively. These experiments clearly indicate that the oxygen sensitivity phenomenon is not solely an effect of competition for reducing equivalents between NT and oxygen via SOD, because NADPH generated by G6PDH and NADH generated by LDH have a similar redox potential. Apparently the system is more complex. The role of specifically NADPH-converting cellular systems such as NADPH-cytochrome P450 reductase was excluded because incubations in the presence of exogenous NADPH as substrate for these systems revealed oxygen sensitivity. Involvement of NADPH-dependent lipid peroxidation in the oxygen sensitivity test is discussed.

The precise histochemical localization and quantification of the activity of soluble dehydrogenases in unfixed cryostat sections requires the use of tissue protectants. In this study, two protectants, polyvinyl alcohol (PVA) and agarose gel, were compared for assaying the activity of lactate dehydrogenase (LDH) and glucose-6-phosphate dehydrogenase (G6PDH) in normal female mouse liver. Quantification of enzyme activity was determined cytophotometrically in periportal (PP), pericentral (PC) and midzonal (MZ) areas. No coloured reaction product was present in PVA media after the incubation period. In contrast, the agarose gels appeared to be highly coloured after incubation. As a consequence, sections incubated with gel media were less intensely stained than those incubated in PVA-containing media. The specific G6PDH reaction (test minus control) yielded approximately 75% less formazan in sections incubated by the agarose gel method than with the PVA method. Further, the amount of formazan deposits attributable to G6PDH activity was highest in the midzonal and pericentral zones of the liver lobule with PVA media, and Kupffer cells could be discriminated easily because of their high G6PDH activity. Significant zonal differences or Kupffer cells could not be observed when agarose gel films were used for the detection of G6PDH activity. The LDH localization patterns appeared to be more uniform after incubation with both methods: no significant differences in specific test minus control reactions were seen between PP, PC and MZ. However, less formazan production (33%) was detected in sections incubated with agarose gels when compared with those incubated with PVA media. These results clearly show that the gel method is not suitable for the valid demonstration of activity of (partially) soluble enzymes. Furthermore, our results confirm that a greater proportion of G6PDH than of LDH is present in a soluble form in liver cells.

The efficacy and safety of low doses of amisulpride (50 mg/day) and of fluoxetine (20 mg/day) were compared respectively in 139 and 129 outpatients with dysthymia during three months in a multi-centre double-blind trial. No statistically significant difference between the two groups was found in the number of responders at study-end with the Montgomery and Asberg Depressive Rating Scale, which was the main criterion for efficacy. In addition, amisulpride was well tolerated. These preliminary results suggest that low doses of amisulpride may be effective in the treatment of dysthymic patients.