Tube-building in two epifaunal amphipod species,Corophium insidiosum andJassa falcata

Jassa falcata andCorophium insidiosum are epifaunal tube-building marine amphipods, whose niches overlap in habitat and food requirements. Laboratory experiments were conducted to study the influence of the quality of different available particulate substrates on settlement and tube-building behaviour of these two amphipod species. Our experiments suggest thatC. insidiosum is less specialized in this respect thanJ. falcata. C. insidiosum is able to use organic materials for tube-building such as artificial (Ulva spec. powder) or mixed natural detritus as well as inorganic material (coarse sand); whereasJ. falcata utilizes organic materials, but sand only to a very limited extent.     

Combination of reduced oxygen tension and intermittent hydrostatic pressure: a useful tool in articular cartilage tissue engineering.

Cartilage cells are normally studied under atmospheric pressure conditions and without loading. However, since cartilage exists in a condition of reduced oxygen and intermittent hydrostatic pressure we hypothesized lower partial oxygen pressures (PO2) and different intermittent hydrostatic pressures (IHP) would increase articular chondrocyte proliferation and matrix production and to stabilize chondrocyte phenotype in vitro. Monolayers of adult bovine articular chondrocytes were cultured under 5% or 21% PO2 in combination with IHP (0.2 MPa amplitude, frequencies 5/5s = 0.1 Hz, 30/2 or 2/30 min on/off loading). We measured proliferation (3H-thymidine incorporation) and collagen secretion (protein-binding assay, collagen type II-ELISA and immunocytochemical staining of pericellular collagen types I, II and IX). Reduced PO2 stimulated proliferation and collagen type II and IX secretion of chondrocytes in comparison to 21% PO2. Additionally, collagen type I expression was delayed by low PO2, indicating a stabilization of the cell phenotype. IHP 5/5s and 30/2 min inhibited proliferation but increased collagen secretion (pericellular collagen type IX was decreased). IHP 30/2 min delayed first expression of collagen type I. In contrast, IHP 2/30 min increased proliferation, but lowered collagen expression. All stimulating or inhibiting effects of PO2 and IHP were additive and vice versa. Reduced PO2 and different settings of IHP increased proliferation, collagen secretion, and phenotype stability of chondrocytes. The oxygen- and IHP-induced effects were additive, suggesting that a combination of these parameters might be a useful tool in cartilage tissue engineering.     

Epidemiology of Subacute Sclerosing Panencephalitis (SSPE) in Germany from 2003 to 2009: A Risk Estimation

Subacute sclerosing panencephalitis (SSPE) is a fatal long-term complication of measles infection. We performed an estimation of the total number of SSPE cases in Germany for the period 2003 to 2009 and calculated the risk of SSPE after an acute measles infection. SSPE cases were collected from the Surveillance Unit for Rare Paediatric Diseases in Germany and the Institute of Virology and Immunobiology at the University of Würzburg. The total number of SSPE cases was estimated by capture-recapture analysis. For the period 2003 to 2009, 31 children with SSPE who were treated at German hospitals were identified. The capture-recapture estimate was 39 cases (95% confidence interval: 29.2–48.0). The risk of developing SSPE for children contracting measles infection below 5 years of age was calculated as 1∶1700 to 1∶3300. This risk is in the same order of magnitude as the risk of a fatal acute measles infection.     

Antibody engineering,a strategy for the development of monoclonal antibodies

Antibody engineering is the selection process enabling the isolation of hybridoma clones, each of which produces an antibody with predefined qualities. The state of the art of hybridoma technology is reviewed with emphasis on the results obtained by antibody engineering in our laboratories for the development of monoclonal antibodies for specific use in diagnostic tests. The perspective for in vitro monoclonal antibody production as well as the application of monoclonal antibodies for diagnostic reagents, industrial purification and therapeutic use are indicated.     

Development of an optimized refolding process for recombinant Ala-Glu-IGF-1.

Denatured and reduced N-terminal extended insulin-like growth factor-1 (AE-IGF-1) was purified from Escherichia coli extracts and subjected to in vitro folding. The renaturation process was shown to be a function of the redox potential of the solution. Folding by different methods had no significant effect on the renaturation. A maximal yield of 60% (w/w) was obtained. The folded AE-IGF-1 was enzymatically converted to IGF-1. The major by-product (20% w/w) was identified as scrambled IGF-1. Enzymatic digestion at alkaline and acidic pH suggested two possible disulphide bond arrangements; (i) Cys6-Cys47, Cys18-Cys61, Cys48-Cys52; or (ii) Cys6-Cys52, Cys18-Cys61, Cys47 and Cys48 being in their reduced forms. Energy minimization and molecular modelling suggested that the scrambled IGF-1, having reduced cysteines at positions 47 and 48, was the energetically most stable conformation of the two.