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.     

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.     

Interaction of agrin with laminin requires a coiled-coil conformation of the agrin-binding site within the laminin gamma1 chain

Coiled-coil domains are found in a wide variety of proteins, where they typically specify subunit oligomerization. Recently, we have demonstrated that agrin, a multidomain heparan sulfate proteoglycan with a crucial role in the development of the nerve-muscle synapse, binds to the three-stranded coiled-coil domain of laminin-1. The interaction with laminin mediates the integration of agrin into basement membranes. Here we characterize the binding site within the laminin-1 coiled coil in detail. Binding assays with individual laminin-1 full-length chains and fragments revealed that agrin specifically interacts with the gamma1 subunit of laminin-1, whereas no binding to alpha1 and beta1 chains was detected. By using recombinant gamma1 chain fragments, we mapped the binding site to a sequence of 20 residues. Furthermore, we demonstrate that a coiled-coil conformation of this binding site is required for its interaction with agrin. The finding that recombinant gamma1 fragments bound at least 10-fold less than native laminin-1 indicates that the structure of the three-stranded coiled-coil domain of laminin is required for high-affinity agrin binding. Interestingly, no binding to a chimeric gamma2 fragment was observed, indicating that the interaction of agrin with laminin is isoform specific.     

Recombinant laminin-8 (alpha(4)beta(1)gamma(1)). Production, purification,and interactions with integrins

Laminins are a large family of heterotrimeric extracellular matrix glycoproteins that, in addition to having structural roles, take part in the regulation of processes such as cell migration, differentiation, and proliferation. The laminin alpha(4) chain is widely distributed both in adults and during development in tissues such as cardiac, skeletal and smooth muscle fibers, vascular endothelia, lungs, and in peripheral nerves. It can associate with laminin beta(1)/gamma(1) chains to form laminin-8 and with the beta(2)/gamma(1) chains to form laminin-9. Functional studies on these laminins have been hampered by poor availability of the protein in pure and soluble forms. To facilitate studies on laminin-8, recombinant laminin-8 was produced in a mammalian expression system, purified and shown to form native Y-shaped molecules in rotary shadowing electron microscopy. Integrins mediating cell adhesion to laminin-8 were identified using function-blocking mAbs. The integrin specificities were found to differ somewhat from that of laminin-1. Integrin alpha(6)beta(1) was found to be a major mediator of adhesion of HT-1080 and cultured capillary endothelial cells to laminin-8. Considering the expression patterns of laminin-8 and integrin alpha(6)beta(1) it is likely that the former is a ligand for the latter in vivo as well.     

Entwicklung der Zähne

Dental development takes place in stages over a long period of time. From the 6ths embryonal week, when the dental lamina develops, tooth number and shape are formed, followed by the production of dental hard tissues. Genetic dental developmental defects are not rare. Mostly these defects affect the tooth number, predominantly resulting in a decrease tooth number (hypodontia) which can occur isolated or as a finding in genetic syndromes such as Rieger syndrome, Witkop syndrome or several ectodermal dysplasias. Genetic defects of dental hard tissues are less frequent, different types of isolated enamel defects (amelogenesis imperfecta) are known. Dentinogenesis imperfecta or other dentinal defects are either caused by different mutations of the DSPP gene or a part of osteogenesis imperfecta.     

Das Marfan-Syndrom und verwandte monogene Krankheiten der Aorta

Marfan syndrome (MFS) is an autosomal dominant, pleiotropic disease of the connective tissue with a prevalence of about 1 in 5000 persons. MFS is characterized by manifestations in the cardiovascular system, eye, skeleton, lung, skin, and dura mater that show a high degree of intra- and interfamilial variability. Many manifestations develop during or shortly before puberty; severe complications rarely occur before adulthood. Many patients with MFS display a so-called marfanoid habitus with tall stature, dolichostenomelia (long, narrow extremities), dolichocephaly (disproportionately long and narrow head), as well as other skeletal abnormalities such as scoliosis and pes planus. Scoliosis occurs in approximately 60% of those affected, pectus deformities in up to two thirds. Ectopia lentis is seen in many patients with MFS and is almost always bilateral. MFS is characterized by a high risk for complications such as severe scoliosis or pectus deformities, spontaneous pneumothorax, retinal detachment, or glaucoma secondary to lens luxation. The most severe complications occur in the cardiovascular system, including in particular acute dissection of the ascending aorta, which generally follows a long period of progressive aortic dilatation. Before the introduction of modern treatment modalities, the average life expectancy of persons with MFS was estimated to be 32 years. Today, with medical care in multidisciplinary centers, an average life expectancy of over 60 years can be achieved. This article offers a review of established and novel concepts for the diagnosis and treatment of MFS and other hereditary diseases of the aorta.