Comparability of clinical wear measurements by optical 3D laser scanning in two different centers.

OBJECTIVE: The purpose of this study was to compare the use of different variables to measure the clinical wear of two denture tooth materials in two analysis centers. METHODS: Twelve edentulous patients were provided with full dentures. Two different denture tooth materials (experimental material and control) were placed randomly in accordance with the split-mouth design. For wear measurements, impressions were made after an adjustment phase of 1-2 weeks and after 6, 12, 18, and 24 months. The occlusal wear of the posterior denture teeth of 11 subjects was assessed in two study centers by use of plaster replicas and 3D laser-scanning methods. In both centers sequential scans of the occlusal surfaces were digitized and superimposed. Wear was described by use of four different variables. Statistical analysis was performed after log-transformation of the wear data by use of the Pearson and Lin correlation and by use of a mixed linear model. RESULTS: Mean occlusal vertical wear of the denture teeth after 24 months was between 120μm and 212μm, depending on wear variable and material. For three of the four variables, wear of the experimental material was statistically significantly less than that of the control. Comparison of the two study centers, however, revealed correlation of the wear variables was only moderate whereas strong correlation was observed among the different wear variables evaluated by each center. SIGNIFICANCE: Moderate correlation was observed for clinical wear measurements by optical 3D laser scanning in two different study centers. For the two denture tooth materials, wear measurements limited to the attrition zones led to the same qualitative assessment.

Leukocyte-endothelial cell interaction is necessary for photodynamic therapy induced vascular permeabilization.

BACKGROUND AND OBJECTIVE: Photodynamic therapy (PDT) affects vascular barrier function and thus increases vessel permeability. This phenomenon may be exploited to facilitate targeted drug delivery and may lead to a new clinical application of photodynamic therapy. Here, we investigate the role of leukocyte recruitment for PDT-induced vascular permeabilization. STUDY DESIGN/MATERIAL AND METHODS: Fluorescein isothiocyanate dextran (FITC-D, 2,000 kDa) was injected intravenously 120 minutes after focal PDT on striated muscle in nude mice bearing dorsal skinfold chambers (Visudyne® 800 µg/kg, fluence rate 300 mW/cm2 , light dose of 200 J/cm2). Leukocyte interaction with endothelial cells was inhibited by antibodies functionally blocking adhesion molecules ("MABS-PDT" group, n = 5); control animals had PDT but no antibody injection (group "PDT", n = 7). By intravital microscopy, we monitored leukocyte rolling and sticking in real-time before, 90 and 180 minutes after PDT. The extravasation of FITC-D from striated muscle vessels into the interstitial space was determined in vivo during 45 minutes to assess treatment-induced alterations of vascular permeability. RESULTS: PDT significantly increased the recruitment of leukocytes and enhanced the leakage of FITC-D. Neutralization of adhesion molecules before PDT suppressed the rolling of leukocytes along the venular endothelium and significantly reduced the extravasation of FITC-D as compared to control animals (156 ± 27 vs. 11 ± 2 (mean ± SEM, number of WBC/30 seconds mm vessel circumference; P < 0.05) at 90 minutes after PDT and 194 ± 21 vs. 14 ± 4 at 180 minutes after PDT). In contrast, leukocyte sticking was not downregulated by the antibody treatment. CONCLUSION: Leukocyte recruitment plays an essential role in the permeability-enhancing effect of PDT.

Characterization of MAP1B heavy chain interaction with actin.

Microtubule-associated protein 1B is an essential protein during brain development and neurite outgrowth and was studied by several assays to further characterize actin as a major interacting partner. Tubulin and actin co-immunoprecipitated with MAP1B at similar ratios throughout development. Their identity was identified by mass spectrometry and was confirmed by Western blots. In contrast to previous reports, the MAP1B-actin interaction was not dependent on the MAP1B phosphorylation state, since actin was precipitated from brain tissue throughout development at similar ratios and equal amounts were precipitated before and after dephosphorylation with alkaline phosphatase. MAP1B heavy chain was able to bind actin directly and therefore the N-terminal part of MAP1B heavy chain must also contain an actin-binding site. The binding force of this interaction was measured by atomic force microscopy and values were in the same range as those of MAP1B binding to tubulin or that measured in MAP1B self-aggregation. Aggregation was confirmed by negative staining and electron microscopy. Experiments including COS-7 cells, PC12 cells, cytochalasin D and immunocytochemistry with subsequent confocal laser microscopy, suggested that MAP1B may bind to actin but has no obvious microfilament stabilizing effect. We conclude, that the MAP1B heavy chain has a microtubule-stabilization effect, and contains an actin-binding site that may play a role in the crosslinking of actin and microtubules, a function that may be important in neurite elongation.

Horizontal vestibulo-ocular reflex dynamics in acute vestibular neuritis and viral labyrinthitis: evidence of otolith-canal interaction.

OBJECTIVE: To evaluate the dynamic properties of the horizontal vestibulo-ocular reflex (h-VOR) in the acute stage of two common labyrinthine diseases that provoke severe attacks of vertigo with spontaneous nystagmus: vestibular neuritis (vestibular loss alone) and viral labyrinthitis (cochleovestibular loss). MATERIAL AND METHODS: Sixty-three patients were investigated: 42 were diagnosed with vestibular neuritis and 21 with viral labyrinthitis. The h-VOR function was evaluated by conventional caloric and impulsive testing. A simplified model of vestibular function was used to analyze the vestibulo-ocular response to rotational stimulation. RESULTS: The results showed a significant difference in h-VOR characteristics between the two pathologies. Patients with vestibular neuritis exhibited a strong horizontal semicircular canal deficit, but no h-VOR asymmetry between the two rotational directions. In contrast, patients with viral labyrinthitis demonstrated moderate canal paresis and a marked h-VOR deficit in rotation toward the affected ear. CONCLUSION: These findings support the hypothesis that the h-VOR dynamic asymmetry that occurs after an acute unilateral inner ear lesion is not due to canal dysfunction alone, but involves complex adaptive changes in the central VOR that may implicate the otolith system. Based on histopathologic and clinical differences in the two pathologies reported in the literature, we postulate that this otolith-canal interaction is mainly linked to the loss of saccular function.

Melt/peridotite interaction in the Southern Lanzo peridotite: Field, textural and geochemical evidence

This paper presents field, petrographic-structural and geochemical data on spinet and plagioclase peridotites from the southern domain of the Lanzo ophiolitic peridotite massif (Western Alps). Spinet lherzolites, harzburgites and dunites crop out at Mt. Arpone and Mt. Musine. Field evidence indicates that pristine porphyroclastic spinet lherzolites are transformed to coarse granular spinet harzburgites, which are in turn overprinted by plagioclase peridotites, while strongly depleted spinet harzburgite and dunite bands and bodies replace the plagioclase peridotites. On the northern flank of Mt. Arpone, deformed, porphyroclastic (lithospheric) lherzolites, with diffuse pyroxenite banding, represent the oldest spinel-facies rocks. They show microstructures of a composite subsolidus evolution, suggesting provenance from deeper (asthenospheric) mantle levels and accretion to the lithosphere. These protoliths are locally transformed to coarse granular (reactive) spinet harzburgites and dunites, which show textures reminiscent of melt/rock reaction and geochemical characteristics suggesting that they are products of peridotite interaction with reactively percolating melts. Geochemical data and modelling suggest that <1-5% fractional melting of spinel-facies DMM produced the injected melts. Plagioclase peridotites are hybrid rocks resulting from pre-existing spinet peridotites and variable enrichment of plagioclase and micro-gabbroic material by percolating melts. The impregnating melts attained silica-saturation, as testified by widespread orthopyroxene replacement of olivine, during open system migration in the lithosphere. At Mt. Musine, coarse granular spinet harzburgite and dunite bodies replace the plagioclase peridotites. Most of these replacive, refractory peridotites have interstitial magmatic clinopyroxene with trace element compositions in equilibrium with MORB, while some Cpx have REE-depleted patterns suggesting transient geochemical features of the migrating MORB-type melts, acquired by interaction with the ambient plagioclase peridotite. These replacive spinet harzburgite and dunite bodies are interpreted as channels exploited for focused and reactive migration of silica-undersaturated melts with aggregate MORB compositions. Such melts were unrelated to the silica-saturated melts that refertilized the pre-existing plagioclase peridotites. Finally, MORB melt migration occurred along open fractures, now recorded as gabbroic dikes. Our data document the complexity of rock-types and mantle processes in the South Lanzo peridotite massif and describe a composite tectonic and magmatic scenario that is not consistent with the ``asthenospheric scenario'' proposed by previous authors. We envisage a ``transitional scenario'' in which extending subcontinental lithospheric mantle was strongly modified (both depleted and refertilized) by early melts with MORB-affinity formed by decompression partial melting of the upwelling asthenosphere, during pre-oceanic rifting and lithospheric thinning in the Ligurian Tethys realm. (C) 2006 Elsevier B.V. All rights reserved.