Year-to-year variation in release of Bet v 1 allergen from birch pollen: evidence for geographical differences between West and South Germany

The release of the aeroallergen Bet v 1 from pollen is a major determinant in the etiology of allergic airway disease due to birch pollen. OBJECTIVE: We determined the release of the major birch pollen allergen Bet v 1 from pollen of birch trees growing in 2 different geographic regions in Germany for 2 consecutive years. METHODS: Catkins were collected during pollination in 2002 and 2003 from 82 healthy trees in South (Munich) and West Germany (North Rhine-Westphalia). The release of Bet v 1 from pollen samples was determined by a Bet v 1-specific ELISA. RESULTS: Pollen from South Germany released about 3 times more Bet v 1 than those from West Germany in both 2002 and 2003 (p = 0.034 and p = 0.007, respectively). This was independent of the number of pollen during the pollen flight season. In 2003, the release of Bet v 1 from pollen was more than 5 times higher than in 2002 in both regions (South Germany 6.1 times, p < 0.001; West Germany 5.4 times, p = 0.003). CONCLUSIONS: Despite large individual differences, there seem to be regional and year-to-year variations in Bet v 1 release from birch pollen. Therefore, the combination of pollen count and release of Bet v 1 from this pollen must be assessed to estimate Bet v 1 exposure reliably. 2007 S. Karger AG, Base

Amination of enzymes to improve biocatalyst performance: coupling genetic modification and physicochemical tools

Improvement of the features of an enzyme is in many instances a pre-requisite for the industrial implementation of these exceedingly interesting biocatalysts. To reach this goal, the researcher may utilize different tools. For example, amination of the enzyme surface produces an alteration of the isoelectric point of the protein along with its chemical reactivity (primary amino groups are the most widely used to obtain the reaction of the enzyme with surfaces, chemical modifiers, etc.) and even its “in vivo” behavior. This review will show some examples of chemical (mainly modifying the carboxylic groups using the carbodiimide route), physical (using polycationic polymers like polyethyleneimine) and genetic amination of the enzyme surface. Special emphasis will be put on cases where the amination is performed to improve subsequent protein modifications. Thus, amination has been used to increase the intensity of the enzyme/support multipoint covalent attachment, to improve the interaction with cation exchanger supports or polymers, or to promote the formation of crosslinkings (both intra-molecular and in the production of crosslinked enzyme aggregates). In other cases, amination has been used to directly modulate the enzyme properties (both in immobilized or free form). Amination of the enzyme surface may also pursue other goals not related to biocatalysis. For example, it has been used to improve the raising of antibodies against different compounds (both increasing the number of haptamers per enzyme and the immunogenicity of the composite) or the ability to penetrate cell membranes. Thus, amination may be a very powerful tool to improve the use of enzymes and proteins in many different areas and a great expansion of its usage may be expected in the near future.This work has been supported by grant CTQ2013-41507-R from Spanish MINECO, grant no. 1102-489-25428 from COLCIENCIAS and Universidad Industrial de Santander (VIE-UIS Research Program) and CNPq and FAPERGS (Brazil). A. Berenguer-Murcia thanks the Spanish Ministerio de Ciencia e Innovacion for a Ramon y Cajal fellowship (RyC-2009–03813)

EVALUATION OF CLUSTER STABILITY WITH PERMUTATION SUBGROUPS

This paper suggests a new methodology; using permutation subgroups to evaluate the stability of clusters. This could be any subgroup and the clustering solution can come from any clustering technique. Mainly, this paper shows how the proposed methodology can be performed through an example of using the rotational cyclic group. The example uses spatially connected clusters that are being created with agglomerative linkage methods. The proposed methodology is demonstrated on Swedish election data and is further evaluated using simulated data. In the example, the simulation results show that the suggested methodology tends to follow the theoretical reasoning of how stable a cluster should be, depending on clustering technique, size, and spatial connectivity. Lastly, further developments of the suggested methodology are presented, along with other possible applications