Impact of dry mouth conditions on oral health-related quality of life in older people

Objective: The aim of the present study was to evaluate the impact of dry mouth conditions on oral health‐related quality of life in frail old people, residents at community care centers. Further, reliability and validity of a visual analogue scale (VAS) for dry mouth symptoms were determined within the study cohort. Background: In old people functional, social and psychological impacts of oral conditions are associated with an overall sense of well being and general health. Subjective dry mouth and reduced saliva flow are common disorders in old people caused by disease and medication. Thus, dry mouth conditions may be determinants for compromised oral health‐related quality of life in old people. Method: In total, 50 old people living at service homes for the old people were asked to answer questionnaires on subjective dry mouth (VAS) and Oral Health Impact Profile (OHIP14) for oral health‐related quality of life. Saliva flow was estimated by absorbing saliva into a pre‐weighed cotton roll. Results: The final study cohort comprised 41 old people (aged 83–91 years). Significant associations were identified between both objective and subjective dry mouth and overall or specific aspects of oral health‐related quality of life. Conclusion: Dry mouth (objective and subjective) is significantly associated with oral health‐related quality of life strengthening the value of monitoring dry mouth conditions in the care of frail old people.     

Reverse Structural Genomics: AN UNUSUAL FLAVIN-BINDING SITE IN A PUTATIVE PROTEASE FROM BACTEROIDES THETAIOTAOMICRON

The structure of a putative protease from Bacteroides thetaiotaomicron features an unprecedented binding site for flavin mononucleotide. The flavin isoalloxazine ring is sandwiched between two tryptophan residues in the interface of the dimeric protein. We characterized the recombinant protein with regard to its affinity for naturally occurring flavin derivatives and several chemically modified flavin analogs. Dissociation constants were determined by isothermal titration calorimetry. The protein has high affinity to naturally occurring flavin derivatives, such as riboflavin, FMN, and FAD, as well as lumichrome, a photodegradation product of flavins. Similarly, chemically modified flavin analogs showed high affinity to the protein in the nanomolar range. Replacement of the tryptophan by phenylalanine gave rise to much weaker binding, whereas in the tryptophan to alanine variant, flavin binding was abolished. We propose that the protein is an unspecific scavenger of flavin compounds and may serve as a storage protein in vivo.     

Allelopathy of Aquatic Autotrophs

Allelopathy in aquatic environments may provide a competitive advantage to angiosperms, algae, or cyanobacteria in their interaction with other primary producers. Allelopathy can influence the competition between different photoautotrophs for resources and change the succession of species, for example, in phytoplankton communities. Field evidence and laboratory studies indicate that allelopathy occurs in all aquatic habitats (marine and freshwater), and that all primary producing organisms (cyanobacteria, micro- and macroalgae as well as angiosperms) are capable of producing and releasing allelopathically active compounds. Although allelopathy also includes positive (stimulating) interactions, the majority of studies describe the inhibitory activity of allelopathically active compounds. Different mechanisms operate depending on whether allelopathy takes place in the open water (pelagic zone) or is substrate associated (benthic habitats). Allelopathical interactions are especially common in fully aquatic species, such as submersed macrophytes or benthic algae and cyanobacteria. The prevention of shading by epiphytic and planktonic primary producers and the competition for space may be the ultimate cause for allelopathical interactions. Aquatic allelochemicals often target multiple physiological processes. The inhibition of photosynthesis of competing primary producers seems to be a frequent mode of action. Multiple biotic and abiotic factors determine the strength of allelopathic interactions. Bacteria associated with the donor or target organism can metabolize excreted allelochemicals. Frequently, the impact of surplus or limiting nutrients has been shown to affect the overall production of allelochemicals and their effect on target species. Similarities and differences of allelopathic interactions in marine and freshwater habitats as well as between the different types of producing organisms are discussed. Referee: Dr. Friedrich Jüttner, Universität Zürich-Limnologische Station, Institut für Pflanzen biologie, Universität Zürich, Seestrasse 187, Ch-8802 Klichberg ZH, Switzerland     

Durch Seitenwurzelbildung induzierte und spontane Mitosen in den Dauergeweben der Wurzel

Ohne ZusammenfassungDie wesentlichen Untersuchungsergebnisse wurden im Rahmen einer Doktorarbeit am Botanischen Institut der Universität Wien gewonnen. Für Anregung und förderliche Kritik danken wir Herrn Prof. Dr. L.Geitler bestens.     

Remodeling of the adventitia during coronary arteriogenesis

We studied the role of the adventitia in adaptive arteriogenesis during the phase of active growth of coronary collateral vessels (CV) induced by chronic occlusion of the left circumflex coronary artery in canine hearts. We used electron microscopy and immunoconfocal (IF) labeling for bFGF, matrix metalloproteinase (MMP)-2, MMP-9, tissue-type plasminogen activator (tPA), its inhibitor (PAI-1), fibronectin (FN), and Ki-67. Proliferation of smooth muscle cells and adventitial fibroblasts was evident. Quantitative IF showed that adventitial MMP-2, MMP-9, and FN were 9.2-, 7.5-, and 8.6-fold, bFGF was 5.1-fold, and PAI-1 was 3.4-fold higher in CV than in normal vessels (NV). The number of fibroblasts was 5-fold elevated in CV, but the elastic fiber content was 25-fold greater in NV than in CV. Perivascular myocyte damage and induction of endothelial nitric oxide synthase in peri-CV capillaries indicate expansion of CV. It was concluded that adventitial activation is associated with the development of CV through cell proliferation, production of growth factors, and induction of extracellular proteolysis thereby contributing to remodeling during adaptive arteriogenesis.     

Chromosomal localization of the human histamine H1-receptor gene

We have assigned the human histamine H₁-receptor gene to chromosome 3 by Southern blot analysis of a chromosome mapping panel constructed from humanhamster somatic cell hybrids. This assignment was confirmed by in situ hybridization on metaphase chromosomes and involved bands 3p14–p21.     

Driving factors of a vegetation shift from Scots pine to pubescent oak in dry Alpine forests

An increasing number of studies have reported on forest declines and vegetation shifts triggered by drought. In the Swiss Rhone valley (Valais), one of the driest inner‐Alpine regions, the species composition in low elevation forests is changing: The sub‐boreal Scots pine (Pinus sylvestris L.) dominating the dry forests is showing high mortality rates. Concurrently the sub‐Mediterranean pubescent oak (Quercus pubescens Willd.) has locally increased in abundance. However, it remains unclear whether this local change in species composition is part of a larger‐scale vegetation shift. To study variability in mortality and regeneration in these dry forests we analysed data from the Swiss national forest inventory (NFI) on a regular grid between 1983 and 2003, and combined it with annual mortality data from a monitoring site. Pine mortality was found to be highest at low elevation (below 1000 m a.s.l.). Annual variation in pine mortality was correlated with a drought index computed for the summer months prior to observed tree death. A generalized linear mixed‐effects model indicated for the NFI data increased pine mortality on dryer sites with high stand competition, particularly for small‐diameter trees. Pine regeneration was low in comparison to its occurrence in the overstorey, whereas oak regeneration was comparably abundant. Although both species regenerated well at dry sites, pine regeneration was favoured at cooler sites at higher altitude and oak regeneration was more frequent at warmer sites, indicating a higher adaptation potential of oaks under future warming. Our results thus suggest that an extended shift in species composition is actually occurring in the pine forests in the Valais. The main driving factors are found to be climatic variability, particularly drought, and variability in stand structure and topography. Thus, pine forests at low elevations are developing into oak forests with unknown consequences for these ecosystems and their goods and services.     

The 102-Kilobase Unstable Region of Yersinia pestis Comprises a High-Pathogenicity Island Linked to a Pigmentation Segment Which Undergoes Internal Rearrangement

Several pathogenicity islands have recently been identified in different bacterial species, including a high-pathogenicity island (HPI) in Yersinia enterocolitica 1B. In Y. pestis, a 102-kb chromosomal fragment (pgm locus) that carries genes involved in iron acquisition and colony pigmentation can be deleted en bloc. In this study, characterization and mapping of the 102-kb region of Y. pestis 6/69 were performed to determine if this unstable region is a pathogenicity island. We found that the 102-kb region of Y. pestis is composed of two clearly distinct regions: an ≈35-kb iron acquisition segment, which is an HPI per se, linked to an ≈68-kb pigmentation segment. This linkage was preserved in all of the Y. pestis strains studied. However, several nonpigmented Y. pestis strains harboring an irp2 gene have been previously identified, suggesting that the pigmentation segment is independently mobile. Comparison of the physical map of the 102-kb region of these strains with that of strain 6/69 and complementation experiments were carried out to determine the genetic basis of this phenomenon. We demonstrate that several different mechanisms involving mutations and various-size deletions are responsible for the nonpigmented phenotype in the nine strains studied. However, no deletion corresponded exactly to the pigmentation segment. The 102-kb region of Y. pestis is an evolutionarily stable linkage of an HPI with a pigmentation segment in a region of the chromosome prone to rearrangement in vitro.     

External surface area determination of lipid vesicles using trinitrobenzene sulfonate and ultraviolet/visible spectrophotometry

The lamellarity of liposomes is an important parameter to be controlled in liposomal delivery–release applications. A practical estimate of the degree of liposome lamellarity can be obtained by measuring the relative external surface area of the liposomes using a chemical assay. All such assays are based on a signal change caused by exposed marker lipids on reaction with a specific externally added reagent. However, a quantitative determination is often distorted by background reactions and contributions of internal lipid labeling. In the so-called TNBS assay, the marker lipid is phosphatidylethanolamine (PE) and the externally added reagent is TNBS (2,4,6-trinotrobenzene sulfonate). Mechanistic aspects of the TNBS assay were considered for improving the assay. Internal lipid labeling via PE flip-flop and/or TNBS permeation was minimal not only in cholesterol-containing liposomes but also in cholesterol-free liposomes if in the latter case membrane fluidity was decreased by slightly increasing the PE content. Compared with earlier versions of the TNBS assay, the amount of marker lipid and the time for analysis could be reduced considerably. The elaborated protocol was also applied to liposomes prepared from lipidic egg yolk isolates, offering a simple and inexpensive method for the development and in-process control of new liposome formation technologies.