An active single-chain antibody containing a cellulase linker domain is secreted by Escherichia coli

Single-chain antibodies consist of the variable, antigen-bindingdomains of antibodies joined to a continuous polypeptide bygenetically engineered peptide linkers. We have used the flexibleinterdomain linker region of a fungal cellulase to link togetherthe variable domains of an anti-2-phenyloxazolone IgGl and showhere that the resulting single-chain antibody is efficientlysecreted and released to the culture medium of Escherichia coli.The yield of affinity-purified single-chain antibody is 1 -2mg/1 of culture medium and its affinity and stability are comparableto those of the corresponding native IgG.     

mRNA sequences define an unusually restricted IgG response to 2-phenyloxazolone and its early diversification

Light and heavy chain mRNAs of 15 anti-oxazolone antibodies were sequenced directly using synthetic primers. Hybridomas obtained 7 days after primary immunization show that they are of restricted heterogeneity. The majority expressed a single sequence with minor differences concentrated in the D region and joining boundaries D--JH and V kappa--J kappa.     

Progressive neurodegeneration in aspartylglycosaminuria mice

Aspartylglycosaminuria (AGU) is one of the most common lysosomal storage disorders in humans. A mouse model for AGU has been recently generated through targeted disruption of the glycosylasparaginase gene, and at a young age the glycosyl asparaginase-deficient mice demonstrated many pathological changes found in human AGU patients (Kaartinen V, Mononen I, Voncken J-W, Gonzalez-Gomez I, Heisterkamp N, Groffen J: A mouse model for aspartylglycosaminuria. Nat Med 1996, 2:1375-1378). Our current findings demonstrate that after the age of 10 months, the general condition of null mutant mice gradually deteriorated. They suffered from a progressive motoric impairment and impaired bladder function and died prematurely. A widespread lysosomal hypertrophy in the central nervous system was detected. This neuronal vacuolation was particularly severe in the lateral thalamic nuclei, medullary reticular nuclei, vestibular nuclei, inferior olivary complex, and deep cerebellar nuclei. The oldest animals (20 months old) displayed a clear neuronal loss and gliosis, particularly in those regions, where the most severe vacuolation was found. The severe ataxic gait of the older mice was likely due to the dramatic loss of Purkinje cells, intensive astrogliosis and vacuolation of neurons in the deep cerebellar nuclei, and the severe vacuolation of the cells in vestibular and cochlear nuclei. The impaired bladder function and subsequent hydronephrosis were secondary to involvement of the central nervous system. These findings demonstrate that the glycosylasparaginase-deficient mice share many neuropathological features with human AGU patients, providing a suitable animal model to test therapeutic strategies in the treatment of the central nervous system effects in AGU.     

A cloned human germ cell tumor-derived cell line differentiating in culture

We have derived a clonal cell line (HGCT-1) from a lymph node metastasis of a primary testicular germ cell tumor (GCT). The tumor was negative for the embryonal carcinoma (EC) cell marker BerH2 but positive for vimentin, cytokeratin (CK) and desmin. Comparative genomic hybridization (CGH) revealed a high-level amplification at 12p that was observed in both the metastatic tumor and in the cultured HGCT-1 cells. In vitro, the phenotype of HGCT-1 cells was modulated by the culture conditions. In the presence of 10% fetal calf serum (FCS), the majority of HGCT-1 cells lacked CK and desmin. If cultured in 0.5% FCS, HGCT-1 cells acquired a uniform co-expression of vimentin, CK and desmin. Upon treatment with retinoic acid (RA), HGCT-1 cells lost the expression of desmin, but exhibited abundant CK filaments. Simultaneously, they started to express desmoplakin, form desmosomes and flatten on the culture substratum. The RA-induced changes were irreversible, whereas those following the culture in 0.5% FCS were at least partially reversible. When xenografted into an immunosuppressed rat, HGCT-1 cells formed a tumor consisting of epithelial- and mesenchymal-like structures. HGCT-1 cells thus represent a pluripotential cell system with a capacity for reversible phenotypic modulation and for irreversible differentiation into epithelial-type cells. The behavior of this novel cell line, distinct from established EC cell models, suggests a complex regulation of GCT cell differentiation.     

Arsenic Removal from Mine Waters with Sorption Techniques

Potential low-cost sorption materials (mostly industrial by-products) were screened for removal of arsenic from mine effluent water. First, the maximum adsorption capacities were determined in batch tests with various liquid to solid ratios. The highest arsenic sorption capacity, 46 mg As/g of sorption material, was measured for cast iron chips. The most promising materials were also studied in batch tests that assessed the reaction kinetics and in kinetic column tests for their behavior in a filter or reactive barrier application. The column tests revealed the cast iron chips caused clogging in the percolation column when operating with real mine water. A commercial ferric oxi-hydroxide sorption material developed for As removal for drinking water showed good As removal in the column tests. Around 10,000 bed volumes of mine process water containing 2 mg/L of arsenic was treated with this material, and treated water concentrations ranged between 0 and 0.05 mg/L before breakthrough. The measured adsorption capacity for the commercial ferric oxi-hydroxide sorption material was 8.3 mg As/g.     

Exploring influencing factors of technology use for active and healthy ageing support in older adults

ABSTRACT

Aim of this study is to investigate the influence of technological and social cognitive factors for the use of sensor-based technologies for active and healthy ageing (AHA) support by older adults. In a mixed methods approach, data was initially obtained from an online questionnaire completed by older health technology users and used in a regression analysis, where factors from the Technology Acceptance Model (TAM) and the Social Cognitive Theory (SCT) served as predictors for health technology use (HTU). Further, in-depth interviews were conducted with older adults to gain insights into technology use and physical activity behaviour of older adults. The regression analysis showed that the TAM and SCT factors accounted for a significant proportion of variance (39.5%) in HTU. Significant predictors of HTU were physical activity (.399**), social support (.287*), and expectations regarding individual health (.440*) and physical appearance (?.470**), indicating physical activity as mediator for HTU. The qualitative analysis indicated the conflation of technology support with social environments as key for physical activity behaviour in older adults. The findings indicate physical activity as a mediator in HTU by older adults and suggest that the consideration of social factors in health technology design may facilitate the uptake of AHA technologies.     

Automatic detection of harvested trees and determination of forest growth using airborne laser scanning

This paper demonstrates the applicability of small footprint, high sampling density airborne laser scanners for boreal forest change detection, i.e. the estimation of forest growth and monitoring of harvested trees. Two laser acquisitions were carried out on a test site using a Toposys-1 laser scanner. Three-dimensional canopy height models were calculated for both data sets using raster-based algorithms. Object-oriented algorithms were developed for detecting harvested and fallen trees, and for measuring forest growth at plot and stand levels. Out of 83 field-checked harvested trees, 61 could be automatically and correctly detected. All mature harvested trees were detected; it was mainly the smaller trees that were not. Forest growth was demonstrated at plot and stand levels using an object-oriented tree-to-tree matching algorithm and statistical analysis. The precision of the estimated growth, based on field checking or statistical analysis, was about 5 cm at stand level and about 10–15 cm at plot level. The authors expect that the methods may be feasible in large area forest inventories that make use of permanent sample plots. Together with methods for detecting individual sample trees, the methods described may be used to replace a large number of permanent plots with laser scanning techniques.     

Molecular modelling study of antigen binding to oxazolone-specific antibodies: the Ox1 idiotypic IgG and its mature variant with increased affinity to 2-phenyloxazolone

Structural models of the variable domains of the murine anti-2-phenyloxazoloneIgG (Oxl idiotype) and its somatic variant, which has higheraffinity to the hapten 2-phenyloxazolone, were constructed bycomputer-aided model building using known structures of highlyhomologous immunoglobulins as templates. Molecular dynamicssimulations were used to dock the hapten between the V_L andV_H domains. The hapten is predicted to bind to slightly differentsites in the two models. Hypotheses concerning the role of anumber of preferred mutations in anti-oxazolone variants arepresented. These can be tested by mutagenesis and crystallography.In particular, the higher binding affinities of the differentantibody variants are shown to correlate with better complementarityof electrostatics. The molecular dynamic simulations also suggestthat two mobile tryptophans at the mouth of the pocket may playan important role in the binding of hapten.     

Mine Water as a Resource: Selective Removal and Recovery of Trace Antimony from Mine-Impacted Water

The objective of this study was to evaluate the feasibility of combined modular processes to selectively remove Sb from mine-impacted waters in an Arctic environment in order to fulfil local environmental criteria for discharged waters. Novel ion exchange, selective extraction and ultrafiltration, electrocoagulation, and dissolved air flotation technologies were investigated, individually or in combination, from the laboratory- to pilot-demonstration scale. Laboratory-scale testing using Fe₂(SO₄)₃ precipitation, ion exchange resin, selective ion extraction and ultrafiltration, and electrocoagulation with or without subsequent dissolved air flotation indicated that any of the methods are potentially applicable to Sb removal from mine water. The observed differences between Sb and As removal efficiency by ion exchange resin illustrated the need for Sb-specific removal and recovery technologies. Techno-economic analyses showed that treatment of mine water using electrocoagulation-dissolved air flotation yields the lowest comparative life-cycle cost of examined technologies. Results demonstrated increased Sb attenuation efficiency using either electrocoagulation-dissolved air flotation or selective extraction and ultrafiltration, even when treating only 50% of the mine-impacted water, compared with conventional Fe₂(SO₄)₃ precipitation from mine water. Additional investigation is necessary to characterize the long-term stability of the mineral phases in Sb-containing solid residues and to inform selection of Sb recovery methods and utilisation or final disposal options for the residual materials.