bluuebunny/crossref_metadata_2025 huggingface dataset:
A Logarithmic, Scale-Invariant Representation of Speed in Macaque Middle Temporal Area Accounts for Speed Discrimination Performance
Authors: Nover Harris , Anderson Charles H. , DeAngelis Gregory C.
Published: October 2005

Human speed discrimination thresholds follow Weber's law over a large range of reference (i.e., pedestal) speeds, that is, the just-noticeable-difference in speed scales in proportion to the reference speed. We analyzed the neural representation of speed information in macaque middle temporal visual area (MT) to determine whether this representation can account for the basic form of psychophysical data. Based on theoretical considerations, we hypothesized: (1) that the speed tuning curves of MT neurons should be bell-shaped (Gaussian) as a function of the logarithm of speed, (2) that the set of speed-tuning curves should be approximately scale-invariant, (3) that the distribution of speed preferences should be approximately uniform in log speed, and (4) that response variability should be independent of speed preference. Our quantitative analysis of data from 501 MT neurons shows that the neural representation of speed approximately obeys these constraints, with modest deviations particularly at slow speeds. We then used the MT data to predict how speed discrimination thresholds should depend on pedestal speed. The shape of this prediction matches very closely to that of human psychophysical data, accounting for constant Weber fractions over a large range of intermediate speeds as well as a marked departure from Weber's law at slow speeds. Moreover, we show that deviations of the MT representation from the above constraints are important for predicting how psychophysical thresholds depart from Weber's law at slow speeds. These findings support the notion that a logarithmic, approximately scale-invariant representation of speed in area MT limits perceptual speed discrimination.
Hippocampal Neurons Express a Calcineurin-Activated Adenylyl Cyclase
Authors: Chan Guy C.-K. , Tonegawa Susumu , Storm Daniel R.
Published: October 2005

Ca2+-stimulated adenylyl cyclases are important for several forms of neuroplasticity because they couple activity-dependent Ca2+increases to cAMP in neurons. For example, the calmodulin-stimulated adenylyl cyclases, AC1 and AC8, are required for hippocampus-dependent memory and long-lasting long-term potentiation. To identify other mechanisms for Ca2+stimulation of adenylyl cyclases, cultured hippocampal neurons from transgenic mice lacking both AC1 and AC8 [double knock-out (DKO) mice] were analyzed for Ca2+stimulation of intracellular cAMP. Surprisingly, neurons from DKO mice showed significant Ca2+-stimulated cAMP accumulation that was blocked by inhibitors of calcineurin [PP2B (protein phosphatase 2B)], a Ca2+-activated protein phosphatase. Analysis of cultured neurons from calcineurin-/-mice confirmed that hippocampal neurons exhibit a calcineurin-dependent cAMP increase, which may contribute to some forms of neuroplasticity.
Impaired Regulation of Thalamic Pacemaker Channels through an Imbalance of Subunit Expression in Absence Epilepsy
Authors: Budde Thomas , Caputi Luigi , Kanyshkova Tatyana , Staak Rainer , Abrahamczik Christian , Munsch Thomas , Pape Hans-Christian
Published: October 2005

The role of hyperpolarization-activated, cyclic nucleotide-modulated (HCN) channel isoforms and hyperpolarization-activated cation current (Ih) for seizure-related burst firing in thalamocortical (TC) neurons was investigated in a rat genetic model of absence epilepsy [Wistar Albino Glaxo rats, bred in Rijswijk (WAG/Rij)]. Burst discharges in TC neurons locked to seizure activityin vivowere prolonged during blockade ofIhby Cs+and ZD7288 (4-ethylphenylamino-1,2-dimethyl-6-methylaminopyrimidinium chloride).In vitroanalyses revealed a hyperpolarizing shift of half-maximalIhactivation (Vh) in WAG/Rij (Vh= -93.2 mV) compared with nonepileptic controls [August × Copenhagen-Irish (ACI) (Vh= -88.0 mV)]. This effect is explained by a shift of the responsiveness ofIhto cAMP toward higher concentrations in TC neurons from WAG/Rij, as revealed by application of 8-bromo-cAMP and the phosphodiesterase inhibitor IBMX. During blockade of adenylyl cyclase activity,Ihactivation was similar in the two strains, whereas the difference in cAMP responsiveness persisted, thereby voting against different ambient cAMP levels between strains. Increasing the intracellular cAMP level and shiftingIhactivation led to a change from burst to tonic firing mode in WAG/Rij but not in ACI rats. Furthermore, HCN1 expression was significantly increased on mRNA and protein levels, with no changes in HCN2-4 expression. In conclusion, there is an increase in HCN1 expression in the epileptic thalamus, associated with a decrease in cAMP responsiveness ofIhin TC neurons and resulting impairment to control the shift from burst to tonic firing, which, in turn, will prolong burst activity after recruitment ofIhduring absence seizures.
Partial Mitochondrial Inhibition Causes Striatal Dopamine Release Suppression and Medium Spiny Neuron Depolarization via H2O2Elevation, Not ATP Depletion
Authors: Bao Li , Avshalumov Marat V. , Rice Margaret E.
Published: October 2005

Mitochondrial dysfunction is a potential causal factor in Parkinson's disease. We show here that acute exposure to the mitochondrial complex I inhibitor rotenone (30-100 nm; 30 min) causes concentration-dependent suppression of single-pulse evoked dopamine (DA) release monitored in real time with carbon-fiber microelectrodes in guinea pig striatal slices, with no effect on DA content. Suppression of DA release was prevented by the sulfonylurea glibenclamide, implicating ATP-sensitive K+(KATP) channels; however, tissue ATP was unaltered. Because KATPchannels can be activated by hydrogen peroxide (H2O2), as well as by low ATP, we examined the involvement of rotenone-enhanced H2O2generation. Confirming an essential role for H2O2, the inhibition of DA release by rotenone was prevented by catalase, a peroxide-scavenging enzyme. Striatal H2O2generation during rotenone exposure was examined in individual medium spiny neurons using fluorescence imaging with dichlorofluorescein (DCF). An increase in intracellular H2O2levels followed a similar time course to that of DA release suppression and was accompanied by cell membrane depolarization, decreased input resistance, and increased excitability. Extracellular catalase markedly attenuated the increase in DCF fluorescence and prevented rotenone-induced effects on membrane properties; membrane changes were also largely prevented by flufenamic acid, a blocker of transient receptor potential (TRP) channels. Thus, partial mitochondrial inhibition can cause functional DA denervation via H2O2and KATPchannels, without DA or ATP depletion. Furthermore, amplified H2O2levels and TRP channel activation in striatal spiny neurons indicate potential sources of damage in these cells. Overall, these novel factors could contribute to parkinsonian motor deficits and neuronal degeneration caused by mitochondrial dysfunction.
Two-Dimensional Time Coding in the Auditory Brainstem
Authors: Slee Sean J. , Higgs Matthew H. , Fairhall Adrienne L. , Spain William J.
Published: October 2005

Avian nucleus magnocellularis (NM) spikes provide a temporal code representing sound arrival times to downstream neurons that compute sound source location. NM cells act as high-pass filters by responding only to discrete synaptic events while ignoring temporally summed EPSPs. This high degree of input selectivity insures that each output spike from NM unambiguously represents inputs that contain precise temporal information. However, we lack a quantitative description of the computation performed by NM cells. A powerful model for predicting output firing rate given an arbitrary current input is given by a linear/nonlinear cascade: the stimulus is compared with a known relevant feature by linear filtering, and based on that comparison, a nonlinear function predicts the firing response. Spike-triggered covariance analysis allows us to determine a generalization of this model in which firing depends on more than one spike-triggering feature or stimulus dimension. We found two current features relevant for NM spike generation; the most important simply smooths the current on short time scales, whereas the second confers sensitivity to rapid changes. A model based on these two features captured more mutual information between current and spikes than a model based on a single feature. We used this analysis to characterize the changes in the computation brought about by pharmacological manipulation of the biophysical properties of the neurons. Blockage of low-threshold voltage-gated potassium channels selectively eliminated the requirement for the second stimulus feature, generalizing our understanding of input selectivity by NM cells. This study demonstrates the power of covariance analysis for investigating single neuron computation.
Deterministic Multiplicative Gain Control with Active Dendrites
Authors: Mehaffey W. Hamish , Doiron Brent , Maler Leonard , Turner Ray W.
Published: October 2005

Multiplicative gain control is a vital component of many theoretical analyses of neural computations, conferring the ability to scale neuronal firing rate in response to synaptic inputs. Many theories of gain control in single cells have used precisely balanced noisy inputs. Such noisy inputs can degrade signal processing. We demonstrate a deterministic method for the control of gain without the use of noise. We show that a depolarizing afterpotential (DAP), arising from active dendritic spike backpropagation, leads to a multiplicative increase in gain. Reduction of DAP amplitude by dendritic inhibition dilutes the multiplicative effect, allowing for divisive scaling of the firing rate. In contrast, somatic inhibition acts in a subtractive manner, allowing spatially distinct inhibitory inputs to perform distinct computations. The simplicity of this mechanism and the ubiquity of its elementary components suggest that many cell types have the potential to display a dendritic division of neuronal output.
Channel Noise is Essential for Perithreshold Oscillations in Entorhinal Stellate Neurons
Authors: Dorval Alan D. , White John A.
Published: October 2005

Previous experimental and computational work (for review, see White et al., 2000) has suggested that channel noise, generated by the stochastic flicker of voltage-gated ion channels, can be a major contributor to electrical membrane noise in neurons. In spiny stellate neurons of the entorhinal cortex, we remove the primary source of channel noise by pharmacologically blocking the native persistent Na+conductance. Via the dynamic-clamp technique (Robinson and Kawai, 1993; Sharp et al., 1993), we then introduce virtual persistent Na+channels into the membranes of the stellate neurons. By altering the mathematical properties of these virtual “knock-ins,” we demonstrate that stochastic flicker of persistent Na+channels is necessary for the existence of slow perithreshold oscillations that characterize stellate neurons. Channel noise also alters the ability of stellate neurons to phase lock to weak sinusoidal stimuli. These results provide the first direct demonstration that physiological levels of channel noise can produce qualitative changes in the integrative properties of neurons.
Bilbao Crystallographic Server: I. Databases and crystallographic computing programs
Authors: Aroyo Mois Ilia , Perez-Mato Juan Manuel , Capillas Cesar , Kroumova Eli , Ivantchev Svetoslav , Madariaga Gotzon , Kirov Asen , Wondratschek Hans
Published: October 2005

The Bilbao Crystallographic Server is a web site with crystallographic databases and programs available on-line at www.cryst.ehu.es. It has been operating for about six years and new applications are being added regularly. The programs available on the server do not need a local installation and can be used free of charge. The only requirement is an Internet connection and a web browser.

The server is built on a core of databases, and contains different shells. The innermost one is formed by simple retrieval tools which serve as an interface to the databases and permit to obtain the stored symmetry information for space groups and layer groups. The k-vector database includes the Brillouin zones and the wave-vector types for all space groups. As a part of the server one can find also the database of incommensurate structures. The second shell contains applications which are essential for prob lems involving group-subgroup relations between space groups (e.g. subgroups and supergroups of space groups, splittings of Wyckoff positions), while the third shell contains more sophisticated programs for the computation of space-group representations and their correlations for group-subgroup related space groups. There are also programs for calculations focused on specific problems of solid-state physics. The aim of the article is to report on the current state of the server and to provide a brief description of the accessible databases and crystallographic computing programs. The use of the programs is demonstrated by illustrative examples.
Geminography: the crystallography of twins
Authors: Grimmer Hans , Nespolo Massimo
Published: October 2005

The geometric theory of twinning was developed almost a century ago. Despite its age, it still represents the fundamental approach to the analysis and interpretation of twinned crystals, in both the direct and the reciprocal space. In recent years, this theory has been extended not only in its formalism (group-subgroup analysis, chromatic symmetry) but also in its classification of special cases that were not recognized before. The geometrical theory of twinning is thus reviewed here with emphasis on lattice aspects and recent developments. The classification of various types of twins starts with Friedel’s well-known scheme, which distinguishes four cases according to whether the twin index n is equal to or larger than 1 and whether the obliquity ω is equal to or larger than 0: the computation of these quantities is discussed in detail. It is shown that the concept of obliquity is not sufficient to characterize the pseudo-symmetry of a lattice, and the consequent twinning, in the case of manifold twins. The application of the theory of coincidence-site lattices to twinning is presented. Finally, the effect of twinning on the diffraction pattern is illustrated with a number of examples.
OD structures in crystallography — basic concepts and suggestions for practice
Authors: Ďurovič Slavomil , Hybler Jiři
Published: October 2005

The present review deals with some selected topics pertaining to the theory of OD structures of layers founded by K. Dornberger-Schiff. An attention is paid mainly to the notion of VC (Vicinity Condition) structures and to the position of OD (Order-Disorder) structures within the VC structures. Explained is also the notion of MDO (Maximum Degree of Order) structures and indicated their derivation. The importance of a suitable axial setting for periodic OD structures is illustrated by an OD interpretation of the structure of the mineral kermesite. Based on X-ray studies of the mineral cronstedtite, the choice of suitable crystals for X-ray studies, reasons for the occurrence of ‘ghost’ peaks in Fourier maps and the refinement strategy for OD structures, is also discussed.
The four-dimensional magnetic point and space groups
Authors: Souvignier Bernd
Published: October 2005

This paper describes the classification of magnetic point and space groups which are also referred to as antisymmetry groups or black-and-white groups. These groups play an important role in the description of discrete point sets in which the points are not only characterized by their spatial coordinates but also by an additional property taking one of two possible values (e.g. spin up or down). Each operation of a magnetic group may or may not switch the value of this additional property. In this paper, the methods for classifying magnetic groups in arbitrary dimensions are described in an algorithmic fashion. Results of the full classification in four-dimensional space are given and the application of the magnetic groups in this dimension to quasicrystals is indicated.
Bond valence and finite graph symmetries
Authors: Rutherford John S.
Published: October 2005

The graph theory prediction of bond valence distributions in a crystal network is reformulated in a form more familiar to chemists, that of symmetry-adapted functions. The graph theory terms relevant to this exposition are explained, including graph matrices, graph vector spaces and graph automorphism groups.

It was found that the vertex and edge sets of a chemical graph form representations of the graph automorphism group. These representations may be expressed as a sum of irreducible representations using the group character table in the usual way. Alternatively the classes of the individual orbits spanned may be used to derive these irreducible representations. The orthogonal cut and cycle subspaces of the edge space can be defined so as to also transform as a sum of irreducible representations. Hence appropriate symmetry-adapted orthogonal basis vectors may be chosen for the vertex and edge spaces. Removing the usual Equal Valence Rule constraint creates a solution space, a range of possible solutions for a particular prob lem. This solution space may be found by combining a set of contributions from the cut space vectors fixed by the atom valences, with a convex polytope in the cycle space which is defined by the non-negativity of the individual bond valences.

The complete procedure is illustrated for the β-Ga2O3 structure.
A risk-based decision-support system for bridge management
Authors: Flaig K. D. , Lark R. J.
Published: October 2005

Based on a study of those actively involved in bridge management this paper presents a novel framework for an advanced bridge management system. The framework has a modular format and includes components for dealing with inspection, data collection and storage, deterioration modelling, structural assessment, economic appraisal of maintenance, repair and rehabilitation (MR&R) actions through whole-life costing, work programme optimisation methodologies and a number of reporting facilities. Of primary importance to the bridge management process is the assessment of structural adequacy. If assessments are unduly conservative, structures will be unnecessarily restricted or strengthened, whereas if the rules are lax, some structures may be left in service without having an appropriate margin of safety against failure. To address this issue a procedure for a reliability-based assessment approach is presented and it is shown how such an approach, when part of the above system, can provide bridge managers with an innovative, rational, risk-based, decision-support tool.
Stress charts for rigid pavements loaded by 16-wheel tandem axles
Authors: Razouki S. S. , Al-Muhanna R. R.
Published: October 2005

Stress charts are developed for the quick determination of maximum bending tensile stresses for the case of 16-wheel tandem axles (SWTA) on the interior of a concrete pavement slab on a Winkler foundation. The maximum bending moment in the concrete pavement represented by a Westergaard slab on Winkler foundation was obtained analytically by extending the known solution for the case of a uniformly loaded circular segment to the case of multiple circular contact areas. The effect on the maximum bending tensile stress of the modulus of subgrade reaction, modulus of elasticity of concrete, tyre pressure, SWTA load magnitude and SWTA geometry was studied thoroughly. The paper reveals that the effects on the maximum bending tensile stress of variation in the geometry of SWTAs and tyre pressure in Iraq are fairly insignificant, whereas the effects of SWTA load magnitude, relative axle spacing, modulus of subgrade reaction, modulus of elasticity of concrete and slab thickness are quite significant.
Proteomic Analysis of Protein Components in Periodontal Ligament Fibroblasts
Authors: Reichenberg E. , Redlich M. , Cancemi P. , Zaks B. , Pitaru S. , Fontana S. , Pucci‐Minafra I. , Palmon A.
Published: October 2005

Background: Characterization of periodontal ligament (PDL) fibroblast proteome is an important tool for understanding PDL physiology and regulation and for identifying disease‐related protein markers. PDL fibroblast protein expression has been studied using immunological methods, although limited to previously identified proteins for which specific antibodies are available.

Methods: We applied proteomic analysis coupled with mass spectrometry and database knowledge to human PDL fibroblasts.

Results: We detected 900 spots and identified 117 protein spots originating in 74 different genes. In addition to scaffold cytoskeletal proteins, e.g., actin, tubulin, and vimentin, we identified proteins implicated with cellular motility and membrane trafficking, chaparonine, stress and folding proteins, metabolic enzymes, proteins associated with detoxification and membrane activity, biodegradative metabolism, translation and transduction, extracellular proteins, and cell cycle regulation proteins.

Conclusions: Most of these identified proteins are closely related to the extensive PDL fibroblasts’ functions and homeostasis. Our PDL fibroblast proteome map can serve as a reference map for future clinical studies as well as basic research.
Effect of Recombinant Human Bone Morphogenetic Protein‐2, ‐4, and ‐7 on Bone Formation in Rat Calvarial Defects
Authors: Hyun Suk‐Ju , Han Dong‐Kwan , Choi Seong‐Ho , Chai Jung‐Kiu , Cho Kyoo‐Sung , Kim Chong‐Kwan , Kim Chang‐Sung
Published: October 2005

Background: Currently, more than 20 bone morphogenetic proteins (BMPs) have been identified, and many trials have been carried out using recombinant human BMPs (rhBMPs) for bone tissue engineering. However, comparative analyses on bone formative activities of rhBMP using a preclinical model have been limited. Therefore, the aim of this study was to evaluate and compare the osteogenic potential of rhBMP‐2, ‐4, and ‐7 delivered with absorbable collagen sponge (ACS) upon early (2 weeks) and complete (8 weeks) wound healing phases in a critical sized rat calvarial defect model.

Methods: Eight‐millimeter critical sized calvarial defects were created in 30 male Sprague‐Dawley rats. The animals were divided into three groups of 10 animals each. The defects were treated with 0.025 mg/ml rhBMP‐2/ACS, rhBMP‐4/ACS, or rhBMP‐7/ACS. The rats were sacrificed at either 2 (five rats) or 8 (five rats) weeks after surgery, and the results were evaluated histologically, histomorphometrically, and immunohistometrically.

Results: The surgical implantation of rhBMP‐2/ACS, rhBMP‐4/ACS, or rhBMP‐7/ACS resulted in enhanced local bone formation in the rat calvarial defect model at both 2 and 8 weeks. The amount of defect closure, new bone area, and bone density were similar in the three groups at each time point (P >0.05). In terms of bone density and new bone area, there were statistically significant differences between results obtained at 2 weeks and those obtained at 8 weeks in all groups (P <0.05). Two‐way analysis of variance (ANOVA) revealed that there was no correlation between the time and conditions (P >0.05), but time was found to have a strong influence on defect closure, new bone area, and bone density (P <0.05). Irrespective of rhBMP type, positive immunoreactions of osteopontin (OPN) and osteocalcin (OCN) were evident at 2 and 8 weeks. Intense OPN and OCN staining was observed near the newly formed bone as well as in some cells within the new bone.

Conclusions: Within the rhBMP types used, rhBMP concentration, and the observation interval, there appears to be no specific differences in bone regenerative potential. All rhBMPs used in this study may be considered effective factors for inducing bone formation.
T Cells Support Osteoclastogenesis in an In Vitro Model Derived From Human Periodontitis Patients
Authors: Brunetti G. , Colucci S. , Pignataro P. , Coricciati M. , Mori G. , Cirulli N. , Zallone A. , Grassi F.R. , Grano M.
Published: October 2005

Background: Periodontitis is characterized by alveolar bone destruction; however, the mechanisms responsible for bone damage are poorly understood. It has been reported that T cells are implicated in the pathogenesis of periodontitis. It has been also demonstrated that activated T lymphocytes secrete receptor activator of nuclear factor‐kappa B ligand (RANKL) and can support the differentiation of monocytes into resorbing osteoclasts (OCs). Therefore, the purpose of this study was to examine the OC formation in periodontitis patients (PP) and the role of T cells in osteoclastogenesis.

Methods: To study OC formation, we used an in vitro model consisting of unstimulated and unfractionated peripheral blood mononuclear cells (PBMCs) from PP and controls. In parallel, T‐cell–depleted PBMCs from the same patients were also established. The expression of RANKL and tumor necrosis factor‐alpha (TNF‐α) was analyzed by reverse transcription‐polymerase chain reaction (RT‐PCR) and Western blot in fresh T cells isolated from PP and controls. Functional antibodies, anti‐RANKL and anti‐TNF‐α, were utilized to study osteoclastogenesis in PBMC cultures from PP.

Results: We showed that, in unfractionated PBMCs from PP, the OCs spontaneously developed in a T‐cell‐dependent way. The addition of macrophage colony stimulating factor (MCSF) and RANKL was necessary to promote the osteoclastogenesis in T‐cell–depleted PBMC cultures from PP and in unfractionated PBMCs from periodontally healthy controls. Moreover, freshly isolated T cells from PBMCs of PP overexpressed RANKL and TNF‐α. Finally, functional anti‐RANKL and anti‐TNF‐α antibodies significantly inhibited osteoclastogenesis.

Conclusion: Our data suggest that T cells support spontaneous osteoclastogenesis in PP via RANKL and TNF‐α overexpression.
Repair of Class II Furcation Defects After a Reparative Tissue Graft Obtained From Extraction Sockets Treated With Growth Factors: A Histologic and Histometric Study in Dogs
Authors: Soares Fernando Peixoto , Hayashi Fernando , Yorioka Christiane Watanabe , Pannuti Claudio Mendes , Gioso Marco Antonio , Alves de Lima Luiz Antonio Pugliesi , Romito Giuseppe Alexandre , Pustiglioni Francisco Emílio
Published: October 2005

Background: Reparative tissue of extraction sockets was proposed as grafting material in the treatment of periodontal defects. Our hypothesis was that the addition of growth factors to extraction sockets improves the regenerative potential of this tissue when used as a graft. The objective of the present study was to analyze qualitatively and quantitatively the repair of acute Class II furcation defects after they receive this grafting material.

Methods: The second and third upper premolars were extracted from four dogs. Platelet‐derived growth factor (PDGF)‐BB and insulin‐like growth factor (IGF)‐I, at concentrations of 6 μg/ml each, were applied to the resulting sockets. After 5 days, 24 acute defects (12 control and 12 test defects) were created in the second, third, and fourth lower premolars. Only the test sites received the graft. The flaps were positioned coronally on both sides and sutured. After 45 days, the specimens were collected, decalcified, and processed histologically in a buccal‐lingual plane. The parameters were measured horizontally in the buccal‐lingual direction.

Results: Repair was histologically and histometrically similar in the two groups. No significant difference was observed between the test and control groups in the parameters connective tissue, new cementum, new bone, and junctional epithelium.

Conclusion: The use of this graft did not show beneficial effects on the repair of acute Class II furcation defects in dogs.
The Effect of Sputtered Calcium Phosphate Coatings of Different Crystallinity on Osteoblast Differentiation
Authors: Berube Patricia , Yang Yunzhi , Carnes David L. , Stover Robert E. , Boland Edward J. , Ong Joo L.
Published: October 2005

Background: Coating titanium implants with hydroxyapatite (HA) has been suggested to increase osseointegration by stimulating early osteoblast function. The goal of this study was to determine the extent to which the crystalline content of the HA surface affected osteoblast function in vitro.

Methods: Osteoblasts were isolated from fetal rat calvaria. Titanium coupons were sputter coated and analyzed. Mineralized nodule formation on plastic using von Kossa staining was compared to tetracycline and procion dye labeling. Cell proliferation, adhesion, alkaline phosphatase activity, morphology and spreading, and cytoskeletal arrangement were analyzed. Reverse transcription‐polymerase chain reaction (RT‐PCR) was used to determine the expression of mRNA for specific proteins.

Results: The percent crystallinity of coatings was 0% (HA1), 1.9% ± 0.4% (HA2), and 66.4% ± 2.8% (HA3). The nodule formation and cell number were greatest on titanium and HA3 compared to HA1 and HA2 (P <0.01). At weeks 2 to 4, all samples showed strong alkaline phosphatase, osteocalcin, monocyte‐colony stimulating factor (M‐CSF), and receptor activator of nuclear factor kappa B ligand (RANKL) expression, but the specific activity of alkaline phosphatase decreased. Cell adherence was greater than 60% of applied cells for all surfaces except HA3. The cells were significantly more elongated on titanium, with no difference on the HA‐coated surfaces. Actin filaments were arranged peripherally at 5 hours but arranged parallel to the long axis of the cell at 20 hours.

Conclusions: Procion labeling is a valid method for evaluating mineralized nodule formation on opaque surfaces. There were no major differences in osteoblast function using titanium or high‐crystalline coatings, and most functions were decreased on amorphous or low‐crystalline coatings.
Factors Affecting the Outcomes of Coronally Advanced Flap Root Coverage Procedure
Authors: Huang Lien‐Hui , Neiva Rodrigo E.F. , Wang Hom‐Lay
Published: October 2005

Background: The coronally advanced flap (CAF) has been used to treat gingival recession. However, the final outcomes (percentage of root coverage) vary from case to case. Hence, the purpose of this study was to analyze the factors that may affect the results of CAF root coverage procedures.

Methods: Twenty‐three systemically healthy patients (mean age, 43.8 ± 11.9 years) each with one Miller's Class I buccal recession defect were included. Baseline clinical parameters included recession depth (RD), recession width (RW), gingival thickness (GT), width of keratinized tissue (WKT), clinical attachment level (CAL), probing depth (PD), plaque index (PI), and gingival index (GI). CAF root coverage procedures were performed to correct the recession defects. Patients were followed at 2, 4, 12, and 24 weeks post‐surgery, at which time wound healing index (WHI) and other measurements were recorded.

Results: The mean baseline RD was 2.9 ± 0.4 mm; RW, 3.4 ± 0.6 mm; WKT, 2.7 ± 1.3 mm; and GT, 1.1 ± 0.3 mm. At mid‐buccal, the mean CAL was 4.5 ± 0.8 mm. Six months after surgery, the average RC was 82.3% ± 24.7%; RD, 0.5 ± 0.7 mm; RW, 0.4 ± 0.9 mm; WKT, 3.2 ± 0.9 mm; and GT, 1.5 ± 0.5 mm. At mid‐buccal, the mean CAL was 1.8 ± 1.1 mm. From baseline to the 6‐month follow‐up, the changes of RC, RD, RW, WKT, GT, and CAL showed statistical significance (P <0.05). Fourteen patients achieved 100% RC. The mean RC in partial coverage cases was 54.8% ± 16.8%. Analysis revealed that an initial GT thicker than 1.2 ± 0.3 mm was associated with complete root coverage at the 6‐month follow‐up (P <0.05).

Conclusions: CAF is a predictable procedure to treat Miller's Class I mucogingival defects. Initial GT was the most significant factor associated with complete root coverage.
Human Gingival Fibroblast Integrin Subunit Expression on Titanium Implant Surfaces
Authors: Oates Thomas W. , Maller Steven C. , West Jason , Steffensen Bjorn
Published: October 2005

Background: Implant surface characteristics have been shown to modify cell behavior and regulate integrin expression. Integrin expression and resultant integrin‐mediated cellular activity are essential components of tissue healing and homeostasis. Although both osseous and soft tissue healing around dental implants are critical to clinical success, there is limited information available on the effect of implant surfaces on integrin expression in soft tissues. Therefore, the aim of this study was to examine integrin expression for gingival fibroblasts on titanium surfaces and the influence of titanium surface roughness on integrin expression and cell morphology.

Methods: Human gingival fibroblasts were cultured on smooth (polished) and rough (sand‐blasted acid‐etched) titanium surfaces and a cell culture plastic (control) surface. To analyze integrin expression, total RNA was isolated from experimental and control cells, and levels of integrin subunit mRNA were assessed by reverse transcription‐polymerase chain reaction (RT‐PCR) using primers specific for the α2, α4, α5, αv, and β1 integrin subunits and aldolase (internal control). PCR products were analyzed by polyacrylamide gel electrophoresis (PAGE), confirmed via DNA sequencing, and quantified using computer‐assisted densitometry. The expression of the integrin subunits was analyzed at the protein level using flow cytometry, as well as fluorescence and confocal laser microscopy. Cell morphology was evaluated using scanning electron microscopy (SEM).

Results: Our experiments demonstrated cellular expression of the α2, α4, α5, αv, and β1 integrin subunits at both mRNA and protein levels on all surfaces. In addition, the α4 and β1 mRNA levels were significantly increased on smooth titanium relative to plastic surfaces (P <0.05) with intermediate mRNA levels found on the rough titanium surfaces. The smooth titanium surfaces exhibited a flat monolayer of cells, while rough titanium surfaces showed cells orienting themselves along surface irregularities.

Conclusions: These results demonstrate the presence of multiple integrin subunits in human gingival fibroblasts grown in contact with titanium implant surfaces and that titanium surface roughness alters cellular morphology but appears to have limited effects on integrin expression. This study provides insight into the complicated cellular and molecular events occurring at the implant surface that may be critical to optimizing the soft tissue interactions with the soft tissue‐implant interface.
Oral Health Impacts on Daily Living Related to Four Different Treatment Protocols for Chronic Periodontitis
Authors: D'Avila Gustavo B. , Carvalho Lucia H. , Feres‐Filho Eduardo J. , Feres Magda , Leão Anna
Published: October 2005

Background: The aims of this study were to evaluate the oral health impacts perceived by patients submitted to different treatments of chronic periodontitis and their association with clinical parameters.

Methods: Sixty patients were assigned to one of the following therapeutic groups: control, treated with full‐mouth scaling and root planing (SRP); test 1, treated with SRP and 400 mg systemically administered metronidazole (MET) three times per day for 10 days; test 2, treated with SRP and professional supragingival plaque removal (PP) every week for 3 months; and test 3, treated with SRP and MET plus PP. Clinical periodontal measurements and data regarding patients' oral health impacts (perceived impacts on bleeding gums, gingival recession, sensitivity to cold, packing foods, aesthetics, bad breath, and tooth mobility) were collected at baseline and 3 months after therapy.

Results: All groups presented significant improvement in oral health perceived impacts. There was no statistically significant difference in the improvement of oral health impacts among groups subjected to different treatments. The clinical data of percentage of deep probing depth, deep clinical attachment level, and bleeding on probing were found to be correlated significantly with oral health impacts.

Conclusions: Periodontal treatment leads to a significant reduction of self‐perceived impacts regardless of the non‐surgical treatment protocol employed. Most of the clinical data were associated with oral health impacts.
A Comparison of Three Techniques to Obtain Root Coverage on Mandibular Incisors
Authors: Harris Randall J. , Miller Laura Harris , Harris Christopher R. , Miller Richard J.
Published: October 2005

Background: Multiple variations on the subepithelial connective tissue graft have been shown to produce good clinical results. The goal of this study was to compare three variations in the treatment of recession on mandibular incisors.

Methods: An a priori analysis was done to determine the sample size. Three groups of patients received root coverage procedures on mandibular incisors. Each group was treated with a different variation of a subepithelial graft. The first group received a connective tissue (CT) graft with a coronally positioned flap (CPF) (CPF + CT). The second group received a connective tissue graft with a double pedicle (DP) graft (DP + CT). The third group received a connective tissue graft with a tunneling (TUN) procedure and a laterally positioned (LAT) pedicle (TUN‐LAT + CT). The clinical results of these procedures were compared to determine if one procedure offered an advantage over the other procedures.

Results: All of the procedures produced a statistically significant improvement in the clinical parameters. The groups treated with the DP + CT and TUN‐LAT + CT had greater mean root coverage (95.5% and 90.5%, respectively) than the CPF + CT group (80.2%). Additionally, DP + CT produced a greater increase in keratinized tissue (3 mm) than CPF + CT (1.4 mm) or TUN‐LAT + CT (1.9 mm). There was no statistically significant difference in the mean root coverage of any technique treating defects <3 mm deep (CPF + CT, 90.9%; DP + CT, 96.4%; and TUN‐LAT + CT, 92.1%) or the defects >3 mm deep treated with DP + CT (95.4%) or TUN‐LAT + CT (88.3%). However, the CPF + CT produced less mean root coverage (68.4%) when treating defects ≥3 mm deep. When defects treated as isolated defects were compared to cases where multiple defects were treated, the cases with multiple defects treated with the CPF + CT had less mean root coverage (77%) than cases where single defects were treated with the CPF + CT (90.3%), DP + CT (isolated, 96.7% and multiple, 95.6%), and TUN‐LAT + CT (isolated, 97.2% and multiple, 87.8%).

Conclusions: All three of the procedures were effective in obtaining root coverage and improved clinical parameters on mandibular incisors. Overall, the DP + CT and TUN‐LAT + CT procedures had greater mean root coverage than the CPF + CT technique. Based on this study, when treating defects ≥3 mm deep, one should consider using the DP + CT or TUN‐LAT + CT rather than the CPF + CT. Additionally, when treating multiple defects at a time, one should consider using the DP + CT or TUN‐LAT + CT rather than the CPF + CT. In cases where an increased amount of keratinized tissue is desired, based on this study, the DP + CT may be the best procedure to use.
The Effect of Platelet‐Rich Plasma on the Coronally Advanced Flap Root Coverage Procedure: A Pilot Human Trial
Authors: Huang Lien‐Hui , Neiva Rodrigo E.F. , Soehren Stephen E. , Giannobile William V. , Wang Hom‐Lay
Published: October 2005

Background: Coronally advanced flap (CAF) has been shown to effectively treat gingival recession. Platelet‐rich plasma (PRP), containing autologous growth factors, has been shown to promote soft tissue healing. Therefore, the purpose of this study was to evaluate the effects of PRP in combination with CAF.

Methods: Twenty‐four systemically healthy patients participated in this study. A single Miller's Class I buccal recession defect per patient was treated. These patients were randomly assigned into CAF or PRP + CAF groups. Clinical parameters included recession depth (RD), recession width (RW), gingival thickness (GT), width of keratinized tissue (WKT), clinical attachment level (CAL), probing depth (PD), plaque index (PI), wound healing index (WHI), and gingival index (GI). PRP was prepared from whole blood drawn prior to surgery and applied to root surfaces. Patients were followed at 2, 4, 12, and 24 weeks post‐surgery.

Results: Twenty‐three patients completed the study. The RD at 24 weeks was significantly reduced from 2.9 ± 0.5 to 0.5 ± 0.6 mm in the CAF group (P <0.05) and from 2.8 ± 0.2 to 0.5 ± 0.7 mm in the PRP + CAF group (P <0.05). The mean root coverage was 83.5% ± 21.8% in the CAF group and 81.0% ± 28.7% in the CAF + PRP group (P >0.05). Fourteen out of 23 patients (60.9%) experienced 100% root coverage at the 24‐week postoperative follow‐up.

Conclusion: Based on the results of this pilot study, the application of PRP in CAF root coverage procedure provides no clinically measurable enhancements on the final therapeutic outcomes of CAF in Miller's Class I recession defects.
Mental Disorder and Violent Victimization in a Total Birth Cohort
Authors: Silver Eric , Arseneault Louise , Langley John , Caspi Avshalom , Moffitt Terrie E.
Published: October 2005

Objective. We examined the association between mental disorder and violent victimization in a general population sample.

Methods. We performed a multivariate analysis of violent victimization in a 12-month period on a total birth cohort with follow-up data that assessed, during their 21st year, males and females born in Dunedin, New Zealand, in the early 1970s.

Results. Compared with people with no mental disorder, (1) people with anxiety disorders experienced more sexual assaults, (2) people with schizophreniform disorders experienced more threatened and completed physical assaults, (3) people with alcohol dependence disorders experienced more completed physical assaults, and (4) people with marijuana dependence disorders experienced more attempted physical assaults. These results held after control for psychiatric comorbidity, demographic characteristics, and the study participants’ own violent behavior.

Conclusion. Mentally disordered young adults tend to experience more violent victimization in the community than those without a mental disorder.
State and Metropolitan-Area Estimates of Disability in the United States, 2001
Authors: Okoro Catherine A. , Balluz Lina S. , Campbell Vincent A. , Holt James B. , Mokdad Ali H.
Published: October 2005

Objectives. We sought to provide estimates of disability prevalence for states and metropolitan areas in the United States.

Methods. We analyzed Behavioral Risk Factor Surveillance System data from 2001 for all 50 states and the District of Columbia and 103 metropolitan areas. We performed stratified analyses by demographics for 20 metropolitan areas with the highest prevalence of disability.

Results. State disability estimates ranged from 10.5% in Hawaii to 25.9% in Arizona. Metropolitan disability estimates ranged from 10.2% in Honolulu, Hawaii to 27.1% in Tucson, Ariz. Regional metropolitan medians for disability (range, 17.0–19.7%) were similar across the Northeast, Midwest, and South and were highest in the West. In the 20 metropolitan areas with the highest disability estimates, the prevalence of disability generally increased with age and was higher for women and those with a high-school education or less.

Conclusions. State and metropolitan-area estimates may be used to guide state and local efforts to prevent, delay, or reduce disability and secondary conditions in persons with disabilities.
Incidence of Disability Among Preretirement Adults: The Impact of Depression
Authors: Dunlop Dorothy D. , Manheim Larry M. , Song Jing , Lyons John S. , Chang Rowland W.
Published: October 2005

Objectives. We evaluated the effect of depression on risk, on the basis of standardized assessment, for developing activities of daily living (ADL) disability.

Methods. Depression-related risk on 2-year ADL disability is estimated from 6871 participants in a population–based national sample aged 54–65 years and free of baseline ADL disability. We evaluated the effects of factors amenable to clinical and public health intervention that may explain the relationship between depression and incident disability.

Results. The odds of ADL disability were 4.3 times greater for depressed adults than their non-depressed peers (95% confidence interval=3.1, 6.0). Among depressed adults, 18.7% of African Americans, 8.0% of Whites, and 7.8% of His-panics developed disability within 2 years. The attributable population fraction because of depression is 17.3% (95% confidence interval=11%, 24%). Concurrent health factors moderated depression-associated risk.

Conclusions. Elevated risk of ADL disability onset because of depression, in a cohort whose medical costs will imminently be covered via Medicare, is attenuated by factors amenable to public health intervention. Prevention and/or public health/policy programs that lead to more accessible and effective mental health and medical care could reduce the development of ADL disability among depressed adults.
Accessibility of Health Clubs for People with Mobility Disabilities and Visual Impairments
Authors: Rimmer James H. , Riley Barth , Wang Edward , Rauworth Amy
Published: October 2005

Objective. We sought to examine the accessibility of health clubs to persons with mobility disabilities and visual impairments.

Methods. We assessed 35 health clubs and fitness facilities as part of a national field trial of a new instrument, Accessibility Instruments Measuring Fitness and Recreation Environments (AIMFREE), designed to assess accessibility of fitness facilities in the following domains: (1) built environment, (2) equipment, (3) swimming pools, (4) information, (5) facility policies, and (6) professional behavior.

Results. All facilities had a low to moderate level of accessibility. Some of the deficiencies concerned specific Americans with Disabilities Act guidelines pertaining to the built environment, whereas other deficiency areas were related to aspects of the facilities’ equipment, information, policies, and professional staff.

Conclusions. Persons with mobility disabilities and visual impairments have difficulty accessing various areas of fitness facilities and health clubs. AIMFREE is an important tool for increasing awareness of these accessibility barriers for people with disabilities.
Widening Social Inequalities in Risk for Sudden Infant Death Syndrome
Authors: Pickett Kate E. , Luo Ye , Lauderdale Diane S.
Published: October 2005

Objectives: In 1994, the US Public Health Service launched the “Back to Sleep” campaign, promoting the supine sleep position to prevent sudden infant death syndrome (SIDS). Studies of SIDS in the United States have generally found socioeconomic and race disparities. Our objective was to see whether the “Back to Sleep” campaign, which involves an effective, easy, and free intervention, has reduced social class inequalities in SIDS.

Methods: We conducted a population-based case-cohort study during 2 periods, 1989 to 1991 and 1996 to 1998, using the US Linked Birth/Infant Death Data Sets. Case group was infants who died of SIDS in infancy (N = 21 126); control group was a 10% random sample of infants who lived through the first year and all infants who died of other causes (N=2241218). Social class was measured by mother’s education level.

Results: There was no evidence that inequalities in SIDS were reduced after the Back to Sleep campaign. In fact, odds ratios for SIDS associated with lower social class increased between 1989–1991 and 1996–1998. The race disparity in SIDS increased after the Back to Sleep campaign.

Conclusions: The introduction of an inexpensive, easy, public health intervention has not reduced social inequalities in SIDS; in fact, the gap has widened. Although the risk of SIDS has been reduced for all social class groups, women who are more educated have experienced the greatest decline.