Correction to: Application of a multiphase microreactor chemostat for the determination of reaction kinetics of Staphylococcus carnosus

Unfortunately, in the "How to Cite as" section, the given and the family name of the author was incorrectly published, the correct name is Lladó Maldonado. S.

Application of a multiphase microreactor chemostat for the determination of reaction kinetics of Staphylococcus carnosus

Bioreactors at the microliter scale offer a promising approach to accelerate bioprocess development. Advantages of such microbioreactors include a reduction in the use of expensive reagents. In this study, a chemostat operation mode of a cuvette-based microbubble column bioreactor made of polystyrene (working volume of 550 µL) was demonstrated. Aeration occurs through a nozzle (Ø ≤ 100 µm) and supports submerged whole-cell cultivation of Staphylococcus carnosus. Stationary concentrations of biomass and glucose were determined in the dilution rate regime ranging from 0.12 to 0.80 1/h with a glucose feed concentration of 1 g/L. For the first time, reaction kinetics of S. carnosus were estimated from data obtained from continuous cultivation. The maximal specific growth rate (µ_max = 0.824 1/h), Monod constant (K_S = 34 × 10^{- 3}g_S/L), substrate-related biomass yield coefficient (Y_X/S = 0.315 g_CDW/g_S), and maintenance coefficient (m_S = 0.0035 g_S/(g_CDW·h)) were determined. These parameters are now available for further studies in the field of synthetic biology.

Disposable parallel poly(dimethylsiloxane) microbioreactor with integrated readout grid for germination screening of Aspergillus ochraceus

In this work a disposable, parallel microbioreactor (MBR) suitable for screening in batch or continuous mode is presented. The reactor consists of five parallel microchambers made of poly(dimethylsiloxane) bonded to a glass substrate. A grid structure is engraved on each chamber, allowing subsequent morphology imaging. Measurements are recorded over the entire cultivation period with constant parameters, namely, position and focus in the z-axis. The microdevice may be used for either parallel, uni- or multiparametric screening, and overcomes the drawback of gridless microwell plates which require expensive equipment such as an inverted microscope with an automatic stage. To validate the scalability from laboratory scale to microscale, and thus the cultivation protocol in the MBR, the germination of fungal spores (A. ochraceus) is evaluated for two different key magnitudes (pH and temperature) and compared to the results obtained from conventional laboratory scale systems (flasks and agar plates). Information on germination capacity with regard to interspecies' variability allows for optimization of industrial processes as optimal pH and temperature matched to the mesoscopic cultivation systems. The germination conditions therefore remain unaffected inside the MBR, while providing the following advantages: (i) dramatic reduction of medium consumption, (ii) submerged cultivation with constant oxygen supply, (iii) assured low cost and disposability, and (iv) possibility of a continuous cultivation mode.

[Scientific cooperation in the area of criminologic techniques in Europe]

Due to an increased trend toward professionalism on the part of criminals and the globalization of crime the demands on forensic science have increased. These demands can only be met by international co-operation. A priori all areas of forensic science can be recommended as fields where working together is adequate. Co-operation--depending for example on the amount of work required for planned research and development, on the need for harmonization of methods and techniques or on the complexity of the task--is certainly necessary to a varying extent. In institutionalizing co-operation it is not so much a mere increase in the relevant activities that is offered but much more variety of (new) ideas. In doing this, as will be shown in a couple of examples, the use of new information and communication technology in particular should be increased.

Standardized AgNOR analysis of the invasive tumour front in oral squamous cell carcinomas

In the last decade, silver staining of nucleolar organizer region-associated proteins (AgNORs) has been widely used in tumour pathology both for diagnostic and for prognostic purposes. However, a reliable and reproducible assessment of these proteins on routinely processed archival tissues has only become possible since the recent introduction of standardized staining method and computer-aided morphometric analysis. In the present study, the AgNOR content at the invasive front of 80 squamous cell carcinomas of the floor of the mouth/tongue was investigated using this novel approach, with regard to prognosis and a variety of clinico-pathological parameters. All standardized AgNOR parameters [mean of AgNOR number, mean of AgNOR area, coefficients of variation (CV) of both AgNOR number and area] were statistically significantly associated with the clinical course. The strongest correlation was found for the AgNOR-area univariate analysis (P = 0.006). In multivariate analysis, the mean of AgNOR number could independently predict both overall (P = 0.01) and disease-free survival (P = 0.001). It is concluded that standardized staining and computer-aided analysis of AgNORs are prerequisites for an objective and reproducible AgNOR assessment, which has potential as a supplementary diagnostic and prognostic tool in oral cancer.

Standardized demonstration of silver-stained nucleolar organizer regions-associated proteins in archival oral squamous cell carcinomas and adjacent non-neoplastic mucosa

Standardized silver staining and quantitation of nucleolar organizer regions-associated proteins (AgNORs) on routinely formalin-fixed and paraffin-embedded tissues has been recently established. The present study was designed to assess its applicability and reproducibility on archival oral squamous cell carcinoma specimens, with special emphasis on the invasive tumor front. Standardized image cytometric AgNOR analysis was performed at the invasive zone and central parts of the tumors as well as in adjacent dysplastic and normal oral mucosa by applying a modified silver staining on routinely processed archival tissues after wet autoclave pretreatment for protein retrieval. A statistically highly significant and reproducible difference of all of the four standardized AgNOR parameters evaluated (mean AgNOR number, mean AgNOR area, coefficient of variation (CV) of AgNOR number, and CV of AgNOR area per nucleus) was observed between the different areas assessed; there was a statistically significant gradual decrease in the CV of the AgNOR number from the invasive tumor front to central parts of the carcinomas, from dysplastic mucosa to normal epithelium. The observed increase of AgNORs at the invasive front of oral squamous cell carcinomas seems to indicate a subgroup of tumor cells with increased biosynthetic activity and malignant potential. Wet autoclave pretreatment before silver staining of AgNORs is necessary for a reliable visualization of single AgNOR dots. Second-order statistics of AgNOR features, e.g., CV values, offer a potent and highly reproducible parameter for AgNOR quantitation.

Prognostic value of histobiological factors (malignancy grading and AgNOR content) assessed at the invasive tumour front of oral squamous cell carcinomas

Tumour cells at the invasive front of carcinomas have been found to differ substantially from the rest of tumour cells in a variety of human cancers. The present multivariate survival analysis of 94 oral squamous cell carcinomas (OSCCs) revealed that both the argyrophilic nucleolar organizer regions-associated protein (AgNOR) content of invading tumour cells and a multiparametric histopathological tumour front grade were significantly and independently associated with tumour-related death, irrespective of conventional Broders' grade and clinical stage of the tumours. High tumour front scores and AgNOR content at the invasive OSCC front thus seem to reflect increased malignant potential. Proliferative activity, assessed by standardized AgNOR analysis, most probably represents one of the biological features underlying the usefulness of evaluating the invasive tumour front.