Wasserlinsen als Nutzpflanzen

Duckweeds as crop plants Members of the plant family Lemnaceae (duckweeds) are not only interesting because they represent the smallest flowering plants; they possess also the fastest rates of producing biomass. As aquatic plants, duckweed production is not in competition with other agricultural crops that require fertile land while the cultivation of duckweeds does not contribute to further eutrophication of surface water. Instead, they can be cultivated on municipal or agricultural waste water and remove the nutrients during their propagation and growth. Duckweeds can thus be used for cleaning of waste water and the resulting biomass can be valuable starting material for animal feeds and the production of biofuels. Research focusing on these goals has begun to transfer from research laboratories to pilot plants in different parts of the world, e.g. in New Jersey and North Carolina, USA; Chengdu, P. R. China; and Armidale, Australia.     

Myotone Dystrophien – und ihre Differenzialdiagnosen

The classic myotonic dystrophy, Steinert’s disease (DM1) was first described in 1909, and the second type, Ricker’s disease (DM2), in 1994. In 1992 the disease-causing mutation in DM1 was identified as a CTG repeat in the DMPK gene on chromosome 19q, and in 2001 the DM2 mutation was identified as a CCTG repeat expansion in the ZNF9 gene on chromosome 3q. Multisystemic symptoms of the diseases affect skeletal muscle, brain, eye, heart, and the endocrine system. The pathogenesis of both forms seems to be based on a gain-of-function RNA mechanism and on alterations in RNA metabolism and spliceopathy. Our review focuses on clinical features, diagnostic techniques, and new aspects of molecular pathogenesis and therapy.     

Genetik der monogenen isolierten Alopezien

The monogenic inherited isolated alopecias comprise a group of clinically and genetically heterogeneous forms of hairlessness or hair loss. Clinical classification of the isolated alopecias is based on the onset of the disorder, the regions affected, and the structure of the hair shaft. Men and women are equally affected, and the mode of inheritance is autosomal dominant or autosomal recessive. Since the identification of the keratin gene KRT86 as a cause of the so-called monilethrix in 1997, mutations in nine other genes have been identified for various isolated alopecias. These include other keratin genes for monilethrix (KRT81 and KRT83), the hairless gene for atrichia congenita/papular atrichia, the corneodesmosin gene for the autosomal dominant form of hypotrichosis simplex, and the genes desmoglein 4, lipase H, and the G-protein-coupled receptor P2RY5 (LPAR6) for the autosomal recessive forms of hypotrichosis. Molecular genetic and pathophysiological studies of these rare disorders of hair development have contributed significantly to our understanding of the basic mechanisms of hair loss as well as the physiological mechanisms of hair growth.     

Antibacterial 5′-O-(N-dipeptidyl)-sulfamoyladenosines

The aminoacyl-tRNA synthetase (aaRS) class of enzymes is a validated target for antimicrobial development. Aminoacyl analogues of 5′-O-(N-l-aminoacyl)-sulfamoyladenosines are known to be potent inhibitors of aaRS, but whole cell antibacterial activity of these compounds is very limited, and poor penetration into bacteria has been proposed as the main reason for this. Aiming to find derivatives that better penetrate bacteria, we developed a simple and short method to prepare dipeptidyl-derivatives of 5′-O-(N-l-aminoacyl)-sulfamoyladenosines, and used this method to prepare 18 5′-O-(N-dipeptidyl)-sulfamoyladenosines. The antibacterial activity of these derivatives and a number of reference compounds against S. aureus, E. faecalis and E. coli was determined. Several of the new derivatives showed improved antibacterial activity and an altered spectrum of antibacterial activity.     

CD14 C-159T and early infection with Pseudomonas aeruginosa in children with cystic fibrosis

Early acquisition of Pseudomonas aeruginosa is associated with a poorer prognosis in patients with cystic fibrosis. We investigated whether polymorphisms in CD14, the lipopolysaccharide receptor, increase the risk of early infection. Forty-five children with cystic fibrosis were investigated with annual bronchoalveolar lavage (BAL) and plasma sCD14 levels. Plasma sCD14 levels were significantly lower in children from whom P.aeruginosa was subsequently isolated (492.75 μg/ml vs. 1339.43 μg/ml, p = 0.018). Those with the CD14 -159CC genotype had a significantly increased risk of early infection with P.aeruginosa suggesting that CD14 C-159T plays a role in determining the risk of early infection with P.aeruginosa.     

Culture filtrates of Aspergillus fumigatus induce different modes of cell death in human cancer cell lines

Aspergillus fumigatus culture filtrate (CF) has a potent cytotoxic effect on three human cancer cell lines (DLKP, A549 and HEp-2) and initiates cell death by apoptosis but the execution of the apoptotic process is incomplete. DLKP cells treated with A. fumigatus CF demonstrate features associated with apoptosis but cytoplasmic and nuclear fragmentation were not observed and cells ultimately underwent necrosis. The apoptotic process commenced in A549 and HEp-2 cells upon exposure to CF, cell shrinkage was observed but membrane blebbing and apoptotic body formation were not detected and detached cells died by necrosis. In contrast, extensive nuclear fragmentation and apoptotic body formation were evident in DLKP and A549 cells treated with anti-neoplastic agents. This work indicates that A. fumigatus CF is cytotoxic to cancer cells and can initiate apoptosis but that the complete apoptotic pathway is not followed. This revised version was published online in June 2006 with corrections to the Cover Date.     

Bacterial expression of in vivo-biotinylated aequorin for direct application to bioluminometric hybridization assays

We have constructed a plasmid suitable for bacterial expression of in vivo-biotinylated photoprotein aequorin. The biotin tag facilitates the isolation of aequorin from crude cell extract and the direct complexation of aequorin with streptavidin for the development of highly sensitive hybridization assays, thereby avoiding the need for chemical crosslinking. The plasmid contains a biotin-acceptor coding sequence fused to an apoaequorin gene. The birA gene, encoding biotin protein ligase (BPL), is inserted downstream of the apoaequorin sequence. BPL biotinylates, posttranslationally, the acceptor domain at a unique position. Functional aequorin is generated by incubating the lysate with coelenterazine and is purified by using a monomeric avidin column that allows elution under nondenaturing conditions. The biotinylated aequorin is complexed with streptavidin and used as a reporter molecule in a hybridization assay. The assay entails immobilization of an oligonucleotide probe on microtiter wells followed by hybridization with a denatured DNA target labeled with biotin through PCR. Streptavidin-biotinylated aequorin is used for quantification of the hybrids. Luminescence is measured in the presence of excess Ca(2+). The analytical range extends from 80 amol of target DNA per well (with a signal-to-background ratio of 2.1) up to 40 fmol per well. The coefficient of variation is about 6%. In vivo-biotinylated aequorin produced from 1 liter of culture is sufficient for 300,000 hybridization assays.