Treatment of multiple adjacent Miller class I and II gingival recessions with a Modified Coronally Advanced Tunnel (MCAT) technique and a collagen matrix or palatal connective tissue graft: a randomized, controlled clinical trial

BACKGROUND A newly developed collagen matrix (CM) of porcine origin has been shown to represent a potential alternative to palatal connective tissue grafts (CTG) for the treatment of single Miller Class I and II gingival recessions when used in conjunction with a coronally advanced flap (CAF). However, at present it remains unknown to what extent CM may represent a valuable alternative to CTG in the treatment of Miller Class I and II multiple adjacent gingival recessions (MAGR). The aim of this study was to compare the clinical outcomes following treatment of Miller Class I and II MAGR using the modified coronally advanced tunnel technique (MCAT) in conjunction with either CM or CTG. METHODS Twenty-two patients with a total of 156 Miller Class I and II gingival recessions were included in this study. Recessions were randomly treated according to a split-mouth design by means of MCAT + CM (test) or MCAT + CTG (control). The following measurements were recorded at baseline (i.e. prior to surgery) and at 12 months: Gingival Recession Depth (GRD), Probing Pocket Depth (PD), Clinical Attachment Level (CAL), Keratinized Tissue Width (KTW), Gingival Recession Width (GRW) and Gingival Thickness (GT). GT was measured 3-mm apical to the gingival margin. Patient acceptance was recorded using a Visual Analogue Scale (VAS). The primary outcome variable was Complete Root Coverage (CRC), secondary outcomes were Mean Root Coverage (MRC), change in KTW, GT, patient acceptance and duration of surgery. RESULTS Healing was uneventful in both groups. No adverse reactions at any of the sites were observed. At 12 months, both treatments resulted in statistically significant improvements of CRC, MRC, KTW and GT compared with baseline (p < 0.05). CRC was found at 42% of test sites and at 85% of control sites respectively (p < 0.05). MRC measured 71 ± 21% mm at test sites versus 90 ± 18% mm at control sites (p < 0.05). Mean KTW measured 2.4 ± 0.7 mm at test sites versus 2.7 ± 0.8 mm at control sites (p > 0.05). At test sites, GT values changed from 0.8 ± 0.2 to 1.0 ± 0.3 mm, and at control sites from 0.8 ± 0.3 to 1.3 ± 0.4 mm (p < 0.05). Duration of surgery and patient morbidity was statistically significantly lower in the test compared with the control group respectively (p < 0.05). CONCLUSIONS The present findings indicate that the use of CM may represent an alternative to CTG by reducing surgical time and patient morbidity, but yielded lower CRC than CTG in the treatment of Miller Class I and II MAGR when used in conjunction with MCAT.

The importance of pneumococcal capsule in inate immunity and biofilm formation

Chapter 1 gives an overview about Streptococcus pneumoniae, its role as a human pathogen and its virulence factors. Additionally, biofilm development and its relevance in clinics are introduced, and the innate immune response to pneumococcus as well as bacterial-viral interactions in the upper respiratory tract are also discussed. Chapter 2 emphasizes the three main topics of this thesis: the role of capsule and pneumolysin in the immune response in the respiratory tract, biofilm formation of S. pneumoniae serotypes and commensal streptococci in vitro, and host innate immune responses to RSV and S. pneumoniae during in vitro co-infections. Aims and hypotheses are provided here. Chapter 3 is divided into two parts: First, the release of the pro-inflammatory cytokines CXCL8 and IL-6 from the human pharyngeal epithelial cell line Detroit 562 and from human bronchial epithelial cells (iHBEC) is described in response to S. pneumoniae. Capsule was shown to suppress the release of both cytokines in both cell lines tested, but release was much less from iHBEC cells. During intranasal colonization of mice, suppression of CXCL8 release by the capsule was also observed in vivo, but the effect was only measured in the absence of pneumolysin. Long term, stable nasopharyngeal carriage in a mouse model resulted in the dissemination of nonencapsulated pneumococci into the lungs, whereas encapsulated strains remained in the nasopharynx. The S. pneumoniae capsule thus plays a role in modulation of the pro-inflammatory immune response in the respiratory tract. Second, results on immunological cells and immune regulation in a long term, stable nasopharyngeal carriage mouse model are presented. Mice were infected with encapsulated or nonencapsulated pneumococcal strains, and after 1, 3, 8 and 15 days, were sacrificed to evaluate the numbers of CD45+ cells, neutrophils, macrophages, FoxP3+ regulatory T-cells and CD3+ T-cells in the nasal mucosa as well as the amount of secreted IL-10 in the nasopharynx. Nasopharyngeal colonization which is effectively silent resulted in the stimulation of FoxP3+ regulatory T-cells and IL-10 release associated with immune homeostasis, whereas lung infiltration was required to increase the number of neutrophils and macrophages resulting in a stronger innate immune response in the nasal mucosa. Chapter 4 contains results of mono- and co-stimulation using RSV and pneumococci or pneumococcal virulence factors on the human bronchial epithelial cell line BEAS-2B. An increase in CXCL8 and IL-6 levels was measured for mixed stimulations of RSV and pneumococcus when encapsulated bacteria were used. Increasing pneumolysin concentrations resulted in enhanced CXCL8 levels. Priming of bronchial epithelial cells with RSV opens the door for more severe pneumococcal infections. Chapter 5 is composed of two parts: The first part describes initial biofilm formation of serotypes 6B and 7F in a static model in vitro. Biofilms of both serotypes contained SCVs, but only serotype 6B increased in SCV formation between 16 and 65h of incubation. SCV stability was tested by passaging clones in complex medium, where SCV production is not associated with advantages in growth. Serotype 6B lost the SCV phenotype indicating a fast adaptation to a changing nutritional environment. Limitations of our in vitro model are discussed. The second part is about initial biofilm formation of mixed culture growth of S. pneumoniae with commensal streptococci. Competition dominates this process. S. oralis and pneumococcus compete for nutrients, whereas mixed species growth of S. mitis or S. pseudopneumoniae with S. pneumoniae is mainly influenced by other factors. In Chapter 6 the findings of chapters 3, 4 and 5 are discussed and an outlook for further studies is provided. Chapters 7, 8, 9, 10 and 11 contain the references, the acknowledgements, the curriculum vitae, the appendix and the declaration of originality.

Chlorhexidine and preservation of sound tooth structure in older adults. A placebo-controlled trial

The Trial to Enhance Elderly Teeth Health (TEETH) was designed to test the impact of regular rinsing with a 0.12% chlorhexidine (CHX) solution on tooth loss, and the causes of tooth loss (caries, periodontal disease and trauma) were also investigated. This paper reports on the effectiveness of a 0.12% CHX solution for controlling caries using a tooth surface (coronal and root) survival analysis. A total of 1,101 low income elders in Seattle (United States) and Vancouver (Canada), aged 60-75 years, were recruited for a double-blind clinical trial and assigned to either a CHX (n = 550) or a placebo (n = 551) mouth rinse. Subjects alternated between daily rinsing for 1 month, followed by weekly rinsing for 5 months. All sound coronal and root surfaces at baseline were followed annually for up to 5 years. At each follow-up examination, those tooth surfaces with caries, restored, or extracted were scored as 'carious'. The hazard ratio associated with CHX for a sound surface to become filled, decayed, or extracted was 0.87 for coronal surfaces (95% confidence interval: 0.71-1.14, p = 0.20) and 0.91 for root surfaces (95% confidence interval: 0.73-1.14, p = 0.41). These findings suggest that regular rinsing with CHX does not have a substantial effect on the preservation of sound tooth structure in older adults.

Arctic patterned-ground ecosystems: A synthesis of field studies and models along a North American Arctic Transect

Arctic landscapes have visually striking patterns of small polygons, circles, and hummocks. The linkages between the geophysical and biological components of these systems and their responses to climate changes are not well understood. The "Biocomplexity of Patterned Ground Ecosystems" project examined patterned-ground features (PGFs) in all five Arctic bioclimate subzones along an 1800-km trans-Arctic temperature gradient in northern Alaska and northwestern Canada. This paper provides an overview of the transect to illustrate the trends in climate, PGFs, vegetation, n-factors, soils, active-layer depth, and frost heave along the climate gradient. We emphasize the thermal effects of the vegetation and snow on the heat and water fluxes within patterned-ground systems. Four new modeling approaches build on the theme that vegetation controls microscale soil temperature differences between the centers and margins of the PGFs, and these in turn drive the movement of water, affect the formation of aggradation ice, promote differential soil heave, and regulate a host of system propel-ties that affect the ability of plants to colonize the centers of these features. We conclude with an examination of the possible effects of a climate wan-ning on patterned-ground ecosystems.

Honey Bee Apis mellifera Parasites in the Absence of Nosema ceranae Fungi and Varroa destructor Mites

Few areas of the world have western honey bee (Apis mellifera) colonies that are free of invasive parasites Nosema ceranae (fungi) and Varroa destructor (mites). Particularly detrimental is V. destructor; in addition to feeding on host haemolymph, these mites are important vectors of several viruses that are further implicated as contributors to honey bee mortality around the world. Thus, the biogeography and attendant consequences of viral communities in the absence of V. destructor are of significant interest. The island of Newfoundland, Province of Newfoundland and Labrador, Canada, is free of V. destructor; the absence of N. ceranae has not been confirmed. Of 55 Newfoundland colonies inspected visually for their strength and six signs of disease, only K-wing had prevalence above 5% (40/55 colonies = 72.7%). Similar to an earlier study, screenings again confirmed the absence of V. destructor, small hive beetles Aethina tumida (Murray), tracheal mites Acarapis woodi (Rennie), and Tropilaelaps spp. ectoparasitic mites. Of a subset of 23 colonies screened molecularly for viruses, none had Israeli acute paralysis virus, Kashmir bee virus, or sacbrood virus. Sixteen of 23 colonies (70.0%) were positive for black queen cell virus, and 21 (91.3%) had some evidence for deformed wing virus. No N. ceranae was detected in molecular screens of 55 colonies, although it is possible extremely low intensity infections exist; the more familiar N. apis was found in 53 colonies (96.4%). Under these conditions, K-wing was associated (positively) with colony strength; however, viruses and N. apis were not. Furthermore, black queen cell virus was positively and negatively associated with K-wing and deformed wing virus, respectively. Newfoundland honey bee colonies are thus free of several invasive parasites that plague operations in other parts of the world, and they provide a unique research arena to study independent pathology of the parasites that are present.

All-sky Meteor Orbit System AMOS and preliminary analysis of three unusual meteor showers

All-sky Meteor Orbit System (AMOS) is a semi-autonomous video observatory for detection of transient events on the sky, mostly the meteors. Its hardware and software development and permanent placement on several locations in Slovakia allowed the establishment of Slovak Video Meteor Network (SVMN) monitoring meteor activity above the Central Europe. The data reduction, orbital determination and additional results from AMOS cameras–the SVMN database– as well as from observational expeditions on Canary Islands and in Canada provided dynamical and physical data for better understanding of mutual connections between parent bodies of asteroids and comets and their meteoroid streams. We present preliminary results on exceptional and rare meteor streams such as September ε Perseids (SPE) originated from unknown long periodic comet on a retrograde orbit, suspected asteroidal meteor stream of April α Comae Berenicids (ACO) in the orbit of meteorites Příbram and Neuschwanstein and newly observed meteor stream Camelopardalids (CAM) originated from Jupiter family comet 209P/Linear.

The quasi 16-day wave in mesospheric water vapor during boreal winter 2011/2012

This study investigates the characteristics of the quasi 16-day wave in the mesosphere during boreal winter 2011/2012 using observations of water vapor from ground-based microwave radiometers and satellite data. The ground-based microwave radiometers are located in Seoul (South Korea, 37° N), Bern (Switzerland, 47° N) and Sodankylä (Finland, 67° N). The quasi 16-day wave is observed in the mesosphere at all three locations, while the dominant period increases with latitude from 15 days at Seoul to 20 days at Sodankylä. The observed evolution of the quasi 16-day wave confirms that the wave activity is strongly decreased during a sudden stratospheric warming that occurred in mid-January 2012. Using satellite data from the Microwave Limb Sounder on the Aura satellite, we examine the zonal characteristics of the quasi 16-day wave and conclude that the observed waves above the midlatitudinal stations Seoul and Bern are eastward-propagating s = −1 planetary waves with periods of 15 to 16 days, while the observed oscillation above the polar station Sodankylä is a standing wave with a period of approximately 20 days. The strongest relative wave amplitudes in water vapor during the investigated time period are approximately 15%. The wave activity varies strongly along a latitude circle. The activity of the quasi 16-day wave in mesospheric water vapor during boreal winter 2011/2012 is strongest over northern Europe, the North Atlantic Ocean and northwestern Canada. The region of highest wave activity seems to be related to the position of the polar vortex. We conclude that the classic approach to characterize planetary waves zonally averaged along a latitude circle is not sufficient to explain the local observations because of the strong longitudinal dependence of the wave activity.