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Tomb Nr 1 of the ancient cemetery of Costebelle, attributed to the 4th century AD, contained the skeleton of a pregnant female and that of her foetus in the pelvic cavity. This was aged seven months, was almost complete and showed an exceptional example of bony lesions suggestive of infection. Its etiology suggested the likelihood of early congenital syphilis. This case raises the question of the theory of the importation of venereal disease into Europe, about a 1000 years later, by the crews of Christopher Columbus. The foetus of Costebelle is not an isolated example : other osteo-archaeological findings make a case for the existence of a treponeme (venereal or non venereal) in Europe before 1493.

SDZ NIM 811 is a cyclosporin A analog that is completely devoid of immunosuppressive capacity but exhibits potent and selective anti-human immunodeficiency virus type 1 (HIV-1) activity. The mechanism of action of SDZ NIM 811 is clearly different from those of all other anti-HIV agents described so far. In cell-free assays, it is not an inhibitor of reverse transcriptase, protease, integrase, and it does not interfere with Rev or Tat function. SDZ NIM 811 does not down-regulate CD4 or inhibit fusion between infected and uninfected, CD4-expressing cells. p24 production from chronically HIV-infected cells is not impaired either. To elucidate the mode of action of SDZ NIM 811, we performed DNA PCR analysis in HIV-1 IIIB-infected MT4 cells in one cycle of virus replication. The effects of SDZ NIM 811 on the kinetics of viral DNA synthesis, appearance of two-long terminal repeat circles (2-LTR circles), and integration of DNA were studied. SDZ NIM 811 inhibited 2-LTR circle formation in a concentration-dependent manner, which is indicative of nuclear localization of preintegration complexes. Half-maximal inhibition was achieved at 0.17 microgram/ml; this concentration is close to the 50% inhibitory concentrations (0.01 to 0.2 microgram/ml) for viral growth inhibition. As expected, integration of proviral DNA into cellular DNA was also inhibited by SDZ NIM 811. Analysis of the viral particles produced by SDZ NIM 811-treated, chronically infected cells revealed amounts of capsid proteins, reverse transcriptase activity, and viral RNA comparable to those of the untreated control. However, these particles showed a dose-dependent reduction in infectivity (50% inhibitory concentration of 0.028 microgram/ml) which indicates that the assembly process is also impaired by SDZ NIM 811. Gag proteins are postulated to play a role not only in assembly but also in early steps of viral replication, e.g., nuclear localization of the preintegration complex. Recently, it was reported that HIV-1 Gag protein binds to cyclophilin A, the intracellular receptor for cyclosporin A. Interference with Gag-cyclophilin interaction may be the molecular basis for the antiviral activity of cyclosporin A and its analogs.

During long-term continuous culture of the hybridoma cell line 11317, a better-producing subclone (I1317-SF11), giving improved productivity, has been selected. The comparison of the original cell line (I1317-DC) with this subclone revealed that although the growth patterns of both clones were similar, both in continuous and in batch cultures, considerable differences could be seen between the clones with respect to monoclonal antibody (MAB) accumulation, MAB production rate, the levels of mRNA coding for heavy and light chains of IgG, and some metabolic activities. In continuous culture as well as in batch culture, I1317-SF11 showed increased levels of mRNA coding for kappa and gamma chains compared with I1317-DC and/or a modified ratio of the mRNA species when compared to that in I1317-DC. Using pulse experiments, it could be established that the biosynthesis of both chains was augmented in I1317-SF11. Although the kappa and gamma mRNA levels were modified or inversed for I1317-SF11, the cells always synthesized more kappa than gamma chains. The overall increase in the synthetic activity of I1317-SF11 is suggested as one reason for the considerable increase of IgG productivity and product accumulation in continuous culture as well as in repeated batch cultures. Tests concerning metabolic activity revealed that I1317-SF11 had a predominantly glycolytic metabolism independent of growth requirements, whereas for I1317-DC the metabolism became increasingly glycolytic with increased growth. The antibody yield coefficient of I1317-SF11 on glutamine was significantly higher than that of I1317-DC for the continuous culture, whereas the antibody coefficients on glucose were almost similar for both clones under the different culture conditions used. Both antibody coefficients were considerablly influenced by the specific growth rate.All these facts together lead to the conclusion that subclone I1317-SF11 uses more of the energy available, or it was the energy and/or precursors available for the synthesis and production of MAB more efficiently than the thesis and production of MAB more efficiently than the original cell line. Although the levels of mRNA coding for heavy and light chains of IgG were modified, it could be confirmed that the overall regulation of MAB-synthesis and -production occurs post-translationally and that at higher growth rates, more biosynthetic activity is diverted to biomass production.

A new encapsulation method was developed for the cultivation of mammalian cells. The capsules were produced using a solution of sodium cellulose sulphate (CS)(1.5%) and poly-dimethyl-diallyl-ammonium chloride (PDMDAAC). When CS droplets fell into the precipitation bath consisting of a 2% solution of PDMDAAC, immediately a membrane at the interphase was built up. The influences of varying encapsulation process parameters on capsule characteristics, cell growth, and monoclonal antibody production were tested. This new method showed advantages when compared to other methods mainly due to time simplicity of the whole process.

Biosensors, sondes, and transducer elements are reviewed with respect to the application for fermentation processes of animal cells. Hereby, the possible connection of these elements to the fermentor is shown. Specially, the (possible) online determinations of the viable and total cell count, of the glucose, the lactate, the pyruvate, and the ammonia concentration in the medium of fermentors are presented. Finally, some sensors for the on-line estimation of the product concentration are described.

A new and simple device for the on-line determination of the total cell count in fermentation vessels is presented. It is based on fibre optic techniques, produces a constant infrared signal and determines the cell count via the scattered light. The linear range between the cell count and the infrared response lies between 1 X 10(5) and more than 2 X 10(6) cells per ml. This sensor shows good correlation between the cell count and the infrared response in fermentations with cell viability of more than 80%. The feeding pumps in these fermentations can be controlled via this sensor to get fermentation with stationary cell counts.

Mass culture of immobilized cells in airlift-fermenters usually ends up with the beads accumulating in the foamy layer on the surface of the reactor fluid or, in stirred tankreactors, with partial destruction of the beads. We tried to use an airlift fermenter vessel for growing cells, immobilized in agarose beads. Instead of using the gas for driving, we mounted a slowly turning marine type impeller within the drought tube. Oxygen was supplied on occasional demands by the original sparger. This set up leads to sufficient operational characteristics of the reactor without accumulation of the beads in the foamy layer and without mechanical destruction. Different productivities of either immobilized cells or cells in free suspension culture are reported.