Sicherheit von Blut und Blutprodukten: Testmethoden zum Nachweis der Hepatitisviren B, C und E

Bundesgesundheitsblatt - Gesundheitsforschung - Gesundheitsschutz - Infektionen mit den Hepatitisviren B, C und E (HBV, HCV, HEV) sind über das Blut übertragbar...     

Relationships that Heal: Beyond the Patient-Healer Dyad in Mayan Therapy

Biomedicine fosters particular styles of interaction and behaviors, with the therapeutic relationship seen as occurring between a doctor and patient. In contrast, where alternative modalities of healing are practiced, relationships go beyond a dyadic interaction and include wider social networks. In this article, we propose the existence of a ‘therapeutic unit’ in Maya healing practices in Guatemala that binds healer, wellness seeker, family, and community members, along with the spiritual and natural realms, into a coherent system requiring all of these elements to achieve success. Drawing on interviews with 67 Maya healers, we describe healers’ understanding of raxnaq’il nuk’aslemal (well-being), and show how these interactions activate wider networks that play crucial roles during treatments. We highlight how holism is expressed in relationships typical of indigenous healing systems, and how an appreciation of this is important for developing culturally appropriate health care provision systems.     

Cationic Polymerization of (3‐Aminopropyl)‐tris‐furfuryloxysilane Derivatives—a New Strategy for Complex Hybrid Material Synthesis

The trifunctional (3‐aminopropyl)‐tris‐furfuryloxysilane monomer ( 1 ) is able to undergo both twin polymerization and reaction with electrophilic compounds such as isocyanates. 1 can be readily synthesized from 3‐aminopropyptrimethoxysilane (APTMS) and furfuryl alcohol (FA). The reaction of 1 with three different aromatic isocyanates, namely phenyl isocyanate, diphenylmethane‐4,4′‐diisocyanate (MDI), and a prepolymer consisting of MDI end‐capped polytetramethylene ether glycole (PTMEG), to the corresponding substituted urea derivatives is presented. Three urea derivatives 1‐phenyl‐3‐(3‐tris‐furfuryloxysilyl)propylurea ( 2 ), diphenylmethan‐4,4′‐bis[3(tris‐furfuryloxysilyl)propyl]urea ( 3 ), bis[3(tris‐furfuryloxysilyl)‐propyl]urea‐capped PTMEG‐MDI‐prepolymer ( 4 ) as well as 1 were polymerized to multicomponent organic/inorganic hybrid materials in a one step procedure using methane sulfonic acid as catalyst. The simultaneous formations of poly furfuryl alcohol and polysiloxane networks within the hybrid material are proven by means of solid‐state NMR spectroscopic measurements. The homogeneous distribution of silicon within the solidified hybrid materials is analyzed by scanning electron microscopy, energy dispersive X‐ray spectroscopy, and high‐angle annular dark field‐scanning transmission electron microscopy (HAADF)‐STEM. Homogeneous nanostructured hybrid materials with silicon cluster sizes in the range of 2 nm have been obtained by polymerization of the urea derivatives 2 , 3, and 4 .     

Glycogen synthetic and degradative activities by Actinomyces viscosus and Actinomyces naeslundii of root surface caries and noncaries sites

The relative glycogen synthetic and degradative activities of Actinomyces viscosus and Actinomyces naeslundii, freshly isolated from root surface caries and noncaries sites, were compared. The glycogen synthetic activity was measured by incubating glucose-(or sucrose-)grown resting cells with 100 mM glucose (or sucrose) and U-[14C]-glucose (or U-[14C]-sucrose) on a pH-stat maintained at 5.0, 6.0, and 7.0 for 1 h under anaerobic conditions. For the glycogen degradation assays, after the 1-hour incubation period, the cells were reincubated under similar conditions, but in the absence of external carbon sources. Carbohydrate utilization and total acid formation were also monitored. Both the glucose- and sucrose-grown cells of A. viscosus and A. naeslundii strains originating from root surface caries lesions synthesized approximately twice as much glycogen as the strains of noncaries origin. Although there were significant differences in the rates of glycogen synthesis, the rates of glycogen degradation were essentially the same for the Actinomyces strains from both caries and noncaries sites. However, the time required for glycogen degradation by the strains from caries sites was much longer. This study suggests that the abilities of A. viscosus and A. naeslundii originating from root surface caries lesions to synthesize large amounts of glycogen and to degrade this stored polymer slowly under conditions of starvation, particularly in an acidic environment, may be one of the factors contributing to the cariogenic potential of these organisms in root surface caries.     

CSF-1, RANKL and OPG regulate osteoclastogenesis during murine tooth eruption

During tooth eruption, osteoclast-mediated bone resorption predominates in alveolar bone along the occlusal surface rather than in bone basal to the tooth. CSF-1, RANKL and OPG, regulatory molecules essential for osteoclastogenesis, are expressed during eruption. However, it is unclear if these cytokines exhibit an expression pattern that correlates with sites of osteoclastogenesis in vivo. To address this issue, mouse mandibles, isolated from 1 to 14 days postnatal, were analysed for osteoclast activity using tartrate-resistant acid phosphatase (TRAP) staining as well as colony-stimulating factor-1 (CSF-1), receptor activator of nuclear factor-kappa B ligand (RANKL) and osteoprotegerin (OPG) mRNA expression using in situ hybridisation. Results showed that CSF-1, RANKL and OPG are expressed in a distinct temporal and spatial manner. In the occlusal region, osteoclast activity was maximal at day 5 and correlated with a relative high expression of CSF-1 and RANKL compared to OPG. In basal bone at this time point, osteoclast activity decreased despite persistent CSF-1 expression and was associated with increased expression of OPG compared to RANKL. By day 8, osteoclastogenesis declined and correlated with upregulation of OPG at the occlusal and basal regions, with this effect continuing throughout eruption. These findings suggest that the spatiotemporal pattern and relative abundance of CSF-1, RANKL and OPG during eruption are key determinants of site-specific osteoclast activity in bone surrounding the tooth. Targeting these cytokines to specific regions in alveolar bone may provide a mechanism for regulating osteoclastogenesis in dental disorders associated with altered tooth eruption.