Characterisation of CIME, an experimental chamber for simulating interactions between materials of the cultural heritage and the environment.

An approach consisting in combining in situ and laboratory experiments is often favoured for investigating the mechanisms involved in the weathering of the materials of the cultural heritage. However, the realistic simulation in the laboratory of the environmental conditions ruling the interactions of atmospheric compounds with materials is a very complex task. The aim of this work is to characterise CIME, a new chamber specially built to simulate the interactions between materials of the cultural heritage and the environment. The originality of this instrument is that beside the usual climatic parameters (temperature, relative humidity, solar radiation) and gaseous pollutants, it also allows the controlled injection of different types of particulate matter such as terrigenous, marine and anthropogenic. Therefore, varied realistic atmospheric environments (marine or urban) can be easily simulated within CIME. In addition to the technical description of CIME, this paper shows the first results obtained by the impact of gaseous pollutants on non-durable glass, bronze and limestone. The first experiments for the deposition of different particles (calcite, clays, soot and halite) are also presented.

Construction of a photocatalytic de-polluting field site in the Leopold II tunnel in Brussels.

Within the framework of the European Life+-funded project PhotoPAQ (Demonstration of Photocatalytic remediation Processes on Air Quality), which was aimed at demonstrating the effectiveness of photocatalytic coating materials on a realistic scale, a photocatalytic de-polluting field site was set up in the Leopold II tunnel in Brussels, Belgium. For that purpose, photocatalytic cementitious materials were applied on the side walls and ceiling of selected test sections inside a one-way tunnel tube. This article presents the configuration of the test sections used and the preparation and implementation of the measuring campaigns inside the Leopold II tunnel. While emphasizing on how to implement measuring campaigns under such conditions, difficulties encountered during these extensive field campaigns are presented and discussed. This included the severe de-activation observed for the investigated material under the polluted tunnel conditions, which was revealed by additional laboratory experiments on photocatalytic samples that were exposed to tunnel air. Finally, recommendations for future applications of photocatalytic building materials inside tunnels are given.

Micro-necrotic foci in regression of a murine calvarium transplantable tumor. 3. Histological characteristics of the micro-necrotic foci.

The experiments reported in this communication correlate histiocytes and plasma cells infiltration into the implantation site of Expt.Cal cells, with formation of micro-necrotic foci and tumor regression. Subcutaneous implantation of any subculture from Cont.Cal cells produced lesions which disappeared 48 to 72 hours later. Cont.Cal cells from any subculture produced no tumors. After several subcultures and upon subcutaneous implantation of Expt.Cal cells lesions were formed which develop into solid tumors. The magnitude of oncogenicity of Expt.Cal cells increased with the number of subcultures. Histological examination of the site of implantation revealed actively proliferating fibrosarcoma cells. The characteristics of the cell population confirmed those of actively growing malignant cells. Multinucleated giant cells and Reed-Sternberg cells have been found in all the examined sections from implantation site of Expt.Cal cells. Treatment of oncogenic Expt.Cal cells with vibrio cholera neuraminidase (VCN) rendered the cells non-oncogenic. Inoculation of VCN-modified Expt.Cal cells induced an extensive histiocytes, lymphocytes and plasma cell infiltration leading to tumor cell destruction and formation of micronecrotic foci.

An ultrastructural study of the formation of "dark" and "light" cytoplasmic inclusions by murine cytomegalovirus in mouse submandibular gland.

Electron micrographs of acinar cells of the submandibular glands of CFW mice infected with murine cytomegalovirus, Smith strain, were studied. The resulting viral intracytoplasmic inclusion bodies were classified into two groups termed "light" (relatively electron-lucent) and "dark" (relatively electron-dense). It appeared that the "dark" type was the late stage of inclusion body maturation.

Mechanism of action of BCG vaccine on neoplastic proliferation and host immune responses.

BCG (Bacillus Calmette-Guerin) vaccine, Tice strain, caused a threefold increase in spleen weight of normal animals and a fourfold increase in spleen weight of sarcoma-bearing mice. In the latter group, the BCG vaccine caused infiltration of the sarcoma cells into the peritoneum and tumor metastasis in the spleen. Spleen lymphocytes from mice immunized with neuraminidase-treated sarcoma or from mice that had overcome an inoculum (100 cells) and a challenge (10(4) cells) of sarcoma P-1798 were cytotoxic against 51 Cr- or 14C-2-thymidine-labeled sarcoma cells. The serum of these mice enhanced the cytotoxic activity and inhibited the migration of the syngeneic lymphocytes. These serums also inhibited the migration of peritoneal macrophages from guinea pigs immunized with the sarcoma cells. BCG vaccine enhanced the development and growth of sarcoma P-1798; i.e., 50-100 viable sarcoma cells produced solid tumors in 8% of the untreated animals but in 100% of the BCG-treated animals. The serum of BCG-treated sarcoma-bearing animals inhibited the spleen lymphocyte-mediated cytotoxic action. The spleen lymphocytes from the BCG-treated sarcoma-bearing animals had no effect against 51Cr- or 14C-2-thymidine-labelled sarcoma cells. The data indicate that the serum from BCG-treated sarcoma-bearing animals blocks the spleen lymphocyte-mediated cytotoxic activities directed against proliferation and growth of the sarcoma.