bluuebunny/crossref_metadata_2025 huggingface dataset:
Calcineurin and cytoskeleton in low‐frequency depression
Authors: Silverman‐Gavrila Lorelei B. , Charlton Milton P.
Published: February 2009

J. Neurochem. (2009) 109, 716–732.

Transmitter release at high probability phasic synapses of crayfish neuromuscular junctions depresses by over 50% in 60 min when stimulated at 0.2 Hz. Inhibition of the protein phosphatase calcineurin by intracellular pre‐synaptic injection of autoinhibitory peptide inhibited low‐frequency depression (LFD) and resulted in facilitation of transmitter release. Since this inhibitor had no major effects when injected into the post‐synaptic cell, only pre‐synaptic calcineurin activity is necessary for LFD. To examine changes in phosphoproteins during LFD we performed a phosphoproteomic screen on proteins extracted from motor axons and nerve terminals after LFD induction or treatment with various drugs that affect kinase and phosphatase activity. Proteins separated by PAGE were stained with phospho‐specific/total protein ratio stains (Pro‐Q Diamond/SYPRO Ruby) to identify protein bands for analysis by mass spectrometry. Phosphorylation of actin and tubulin decreased during LFD, but increased when calcineurin was blocked. Tubulin and phosphoactin immunoreactivity in pre‐synaptic terminals were also reduced after LFD. The actin depolymerizing drugs cytochalasin and latrunculin and the microtubule stabilizer taxol inhibited LFD. Therefore, dephosphorylation of pre‐synaptic actin and tubulin and consequent changes in the cytoskeleton may regulate LFD. LFD is unlike long‐term depression found in mammalian synapses because the latter requires in most instances post‐synaptic calcineurin activity.Thus, this simpler invertebrate synapse discloses a novel pre‐synaptic depression mechanism.
Ability of Wildlife Overpasses to Provide Connectivity and Prevent Genetic Isolation
Authors: CORLATTI LUCA , HACKLÄNDER KLAUS , FREY‐ROOS FREDY
Published: February 2009

Abstract: We reviewed research on wildlife overpasses in the context of their genetic effectiveness to provide connectivity between population patches that have been isolated by road construction. The potential ecological consequences of such habitat fragmentation include reduction of gene flow between subpopulations and hence an increase in genetic differentiation and a decrease in genetic diversity. Among the solutions to provide connectivity between patches isolated by roads, wildlife overpasses are one of the most expensive alternatives. Despite the high costs associated with their construction, most of the studies assessing their use by wildlife remain observational, reporting evidence for passage use but few data on the number of individual crossings. Moreover, the use itself of wildlife overpasses does not appear sufficient to assess their effectiveness from a genetic viewpoint because a minimum number of individuals is required to assure gene flow between population patches and because the spatiotemporal dimension of individual movements and demographic parameters of subpopulations must be considered. So far, there is no evidence that wildlife overpasses do or do not efficiently address genetic issues. This lack of data is probably due to the fact that few mitigation efforts have implemented monitoring programs that incorporate sufficient experimental designs into pre‐ and postconstruction evaluation. To assess the genetic effectiveness of wildlife overpasses, long‐term monitoring programs, including fieldwork and genetic analyses, are needed.
Evaluation of a Computerized Method for Denture Biofilm Quantification: Inter‐Examiner Reproducibility
Authors: Silva‐Lovato Cláudia Helena , Totti Ana Maria Gomes , Paranhos Helena Freitas Oliveira , Totti Valéria Gomes
Published: February 2009

Purpose: The objective of this work was to evaluate the accuracy and inter‐examiner reproducibility of the computerized method Image Tool 2.02 (Windows, version 2.02, University of Texas Health Science Center, San Antonio, TX) in the quantification of complete denture biofilm.

Materials and Methods: Two hundred digital photographs of the internal surface of complete upper dentures with biofilm dyed in 1% neutral red were used. The photographs were burned to a CD and sent to two researchers who received practical training and written instructions on how to use the method; then, in a 20‐day period, the stained biofilm on the internal surface was measured, and ten photographs were analyzed daily. Each examiner independently quantified the percentage of stained area on each photograph. The inter‐examiner reproducibility (i.e., agreement) was estimated by calculating an intra‐class correlation coefficient (ICC) based on an ANOVA mixed model (SPSS software, Chicago, IL).

Results: The ICC showed excellent agreement (ICC = 0.993, p < 0.001). The difference in the percentage of the stained area recorded by the two examiners was ≤1 point for 187 (93.5%) of the 200 photographs.

Conclusions: The obtained results suggest that the computerized method aided by the Image Tool software (2.0) can be employed to quantify complete denture biofilm, seeing that it demonstrated inter‐examiner reproducibility of the results.
Flow cytometric assay for the simultaneous determination of residual white blood cells, red blood cells, and platelets in fresh‐frozen plasma: validation and two years' experience
Authors: Lambrecht Bernd , Spengler Hans‐Peter , Nauwelaers Frans , Bauerfeind Ursula , Mohr Harald , Müller Thomas H.
Published: February 2009

BACKGROUND: A fully automated single‐tube assay with tubes (BD TruCOUNT, BD Biosciences) for absolute counting of residual cells in freshly prepared plasma by flow cytometry was developed (BD Plasma Count).

STUDY DESIGN AND METHODS: The nucleic acid dye thiazole orange stains white blood cells (WBCs). The monoclonal antibodies anti‐CD41a–peridinin chlorophyll protein–Cy5.5 and anti‐glycophorin A–fluorescein isothiocyanate label platelets (PLTs) and red blood cells (RBCs), respectively. No fixation, permeabilization, or washing steps were required. Validation was done according to guidelines of the International Conference on Harmonization and the National Committee for Clinical Laboratory Standards. Cell‐free plasma was spiked with each cell type for accuracy, reproducibility, and linearity measurements.

RESULTS: Results showed no carryover or drift under automated sample acquisition conditions. Nonspecific background was fewer than 0.3 cells per µL for residual WBCs (rWBCs), fewer than 2.7 cells per µL for rRBCs, and fewer than 85 cells per µL for rPLTs. Determinations of rWBC and rPLT counts were linear with a coefficient of variation of less than 12 percent for the imprecision. Owing to cross‐linking of the anti‐glycophorin A antibody, linearity and precision for rRBCs diverged up to 21 percent at a count of 6000 rRBCs per µL. In a 2‐year period, five operators investigated 2666 quality control (QC) samples of fresh‐frozen plasma on 108 working days. Maximum cell numbers found were 196 for rWBCs, 3960 for rRBCs, and 28,952 for rPLTs per µL. In 31 cases (1.2%) rWBCs were out of specification. No outlier was observed for rRBCs and rPLTs. Residual RBC cell numbers determined were always within the acceptable concentration range of the assay.

CONCLUSION: These data demonstrate that the single‐tube test is suitable for routine QC assessment of the cellular contaminants of therapeutic plasma according to the European recommendations.
Clinical outcomes after platelet transfusions in patients with thrombotic thrombocytopenic purpura
Authors: Swisher Karen K. , Terrell Deirdra R. , Vesely Sara K. , Kremer Hovinga Johanna A. , Lämmle Bernhard , George James N.
Published: February 2009

BACKGROUND: Reports of deterioration and death after platelet (PLT) transfusions in patients with thrombotic thrombocytopenic purpura (TTP) have led to recommendations that they should not be given except for life‐threatening hemorrhage.

STUDY DESIGN AND METHODS: Published reports of PLT transfusions in patients with TTP were systematically reviewed and data from the Oklahoma TTP‐HUS Registry, an inception cohort of 382 consecutive patients, 1989 through 2007, were analyzed.

RESULTS: A systematic review identified 34 publications describing outcomes of patients with TTP after PLT transfusions: 9 articles attributed complications to PLT transfusions, 4 suggested that they may be safe, and 21 articles did not comment about a relation between PLT transfusions and outcomes. Fifty‐four consecutive patients from the Oklahoma TTP‐HUS Registry were prospectively analyzed. ADAMTS13 activity was less than 10 percent in 47 patients; also included were 7 patients whose activity was not measured but who may have been deficient. Thirty‐three (61%) patients received PLT transfusions. The frequency of death was not different between the two groups (p = 0.971): 8 (24%) patients who received PLT transfusions died (thrombosis, 5; hemorrhage, 1; sepsis, 2) and 5 (24%) patients who did not receive PLT transfusions died (thrombosis, 4; hemorrhage, 1). The frequency of severe neurologic events was also not different (p = 0.190): 17 (52%) patients who received PLT transfusions (in 5 of these 17 patients, neurologic events only occurred before PLT transfusions) and 7 (33%) patients who did not receive PLT transfusions.

CONCLUSION: Evidence for harm from PLT transfusions in patients with TTP is uncertain.
Variable Selection for Clustering with Gaussian Mixture Models
Authors: Maugis Cathy , Celeux Gilles , Martin‐Magniette Marie‐Laure
Published: February 2009

SummaryThis article is concerned with variable selection for cluster analysis. The problem is regarded as a model selection problem in the model‐based cluster analysis context. A model generalizing the model ofRaftery and Dean(2006, Journal of the American Statistical Association 101, 168–178) is proposed to specify the role of each variable. This model does not need any prior assumptions about the linear link between the selected and discarded variables. Models are compared with Bayesian information criterion. Variable role is obtained through an algorithm embedding two backward stepwise algorithms for variable selection for clustering and linear regression. The model identifiability is established and the consistency of the resulting criterion is proved under regularity conditions. Numerical experiments on simulated datasets and a genomic application highlight the interest of the procedure.
Using Regression Models to Analyze Randomized Trials: Asymptotically Valid Hypothesis Tests Despite Incorrectly Specified Models
Authors: Rosenblum Michael , van der Laan Mark J.
Published: February 2009

Summary Regression models are often used to test for cause‐effect relationships from data collected in randomized trials or experiments. This practice has deservedly come under heavy scrutiny, because commonly used models such as linear and logistic regression will often not capture the actual relationships between variables, and incorrectly specified models potentially lead to incorrect conclusions. In this article, we focus on hypothesis tests of whether the treatment given in a randomized trial has any effect on the mean of the primary outcome, within strata of baseline variables such as age, sex, and health status. Our primary concern is ensuring that such hypothesis tests have correct type I error for large samples. Our main result is that for a surprisingly large class of commonly used regression models, standard regression‐based hypothesis tests (but using robust variance estimators) are guaranteed to have correct type I error for large samples, even when the models are incorrectly specified. To the best of our knowledge, this robustness of such model‐based hypothesis tests to incorrectly specified models was previously unknown for Poisson regression models and for other commonly used models we consider. Our results have practical implications for understanding the reliability of commonly used, model‐based tests for analyzing randomized trials.
A Frailty‐Model‐Based Approach to Estimating the Age‐Dependent Penetrance Function of Candidate Genes Using Population‐Based Case‐Control Study Designs: An Application to Data on the BRCA1 Gene
Authors: Chen Lu , Hsu Li , Malone Kathleen
Published: February 2009

SummaryThe population‐based case–control study design is perhaps one of, if not the most, commonly used designs for investigating the genetic and environmental contributions to disease risk in epidemiological studies. Ages at onset and disease status of family members are routinely and systematically collected from the participants in this design. Considering age at onset in relatives as an outcome, this article is focused on using the family history information to obtain the hazard function, i.e., age‐dependent penetrance function, of candidate genes from case–control studies. A frailty‐model‐based approach is proposed to accommodate the shared risk among family members that is not accounted for by observed risk factors. This approach is further extended to accommodate missing genotypes in family members and a two‐phase case–control sampling design. Simulation results show that the proposed method performs well in realistic settings. Finally, a population‐based two‐phase case–control breast cancer study of the BRCA1 gene is used to illustrate the method.
Modeling Inter‐Subject Variability in fMRI Activation Location: A Bayesian Hierarchical Spatial Model
Authors: Xu Lei , Johnson Timothy D. , Nichols Thomas E. , Nee Derek E.
Published: February 2009

Summary The aim of this article is to develop a spatial model for multi‐subject fMRI data. There has been extensive work on univariate modeling of each voxel for single and multi‐subject data, some work on spatial modeling of single‐subject data, and some recent work on spatial modeling of multi‐subject data. However, there has been no work on spatial models that explicitly account for inter‐subject variability in activation locations. In this article, we use the idea of activation centers and model the inter‐subject variability in activation locations directly. Our model is specified in a Bayesian hierarchical framework which allows us to draw inferences at all levels: the population level, the individual level, and the voxel level. We use Gaussian mixtures for the probability that an individual has a particular activation. This helps answer an important question that is not addressed by any of the previous methods: What proportion of subjects had a significant activity in a given region. Our approach incorporates the unknown number of mixture components into the model as a parameter whose posterior distribution is estimated by reversible jump Markov chain Monte Carlo. We demonstrate our method with a fMRI study of resolving proactive interference and show dramatically better precision of localization with our method relative to the standard mass‐univariate method. Although we are motivated by fMRI data, this model could easily be modified to handle other types of imaging data.
Bayesian Partitioning for Modeling and Mapping Spatial Case–Control Data
Authors: Costain Deborah A.
Published: February 2009

SummaryMethods for modeling and mapping spatial variation in disease risk continue to motivate much research. In particular, spatial analyses provide a useful tool for exploring geographical heterogeneity in health outcomes, and consequently can yield clues as to disease etiology, direct public health management, and generate research hypotheses. This article presents a Bayesian partitioning approach for the analysis of individual level geo‐referenced health data. The model makes few assumptions about the underlying form of the risk surface, is data adaptive, and allows for the inclusion of known determinants of disease. The methodology is used to model spatial variation in neonatal mortality in Porto Alegre, Brazil.
Baseline profiles of adolescent vs. adult‐onset first‐episode psychosis in an early detection program
Authors: Joa I. , Johannessen J. O. , Langeveld J. , Friis S. , Melle I. , Opjordsmoen S. , Simonsen E. , Vaglum P. , McGlashan T. , Larsen T. K.
Published: February 2009

Objective:  Psychotic disorders often start in adolescence. We aim to investigate premorbid and baseline differences characterizing patients with an onset of psychosis in adolescence versus adulthood.

Method:  We compare first‐episode, DSM‐IV non‐affective psychosis with onset before (n = 43) and after (n = 189) 18 years on duration of untreated psychosis (DUP), level of symptoms, suicidal behaviour, and other baseline clinical and demographic characteristics.

Results:  Adolescent onset patients had poorer premorbid functioning, a longer DUP, higher suicidality, and more depressive symptoms. They also had better cognition, fewer psychotic symptoms, and were more likely to be treated on an out‐patient basis.

Conclusion:  Adolescents with first‐episode psychosis may have a slower and more silent, i.e. insidious onset, and are at risk of experiencing longer treatment delays than adults. They fit the description of what used to be labeled process (versus reactive) schizophrenia.
Effects of the combination with α‐tricalcium phosphate and simvastatin on bone regeneration
Authors: Nyan Myat , Sato Daisuke , Kihara Hidemichi , Machida Tetsu , Ohya Keiichi , Kasugai Shohei
Published: February 2009

Background: Although local application of statins stimulates bone formation, high dose of simvastatin induces inflammation.

Objective: A study was conducted to test the hypothesis that maximum bone regeneration with less inflammation would be achieved by combining an optimal dose of simvastatin with α‐tricalcium phosphate (α‐TCP), which is an osteoconductive biomaterial capable of releasing the drug gradually.

Material and methods: Bilateral 5‐mm‐diameter calvarial defects were created in adult Wistar rats and filled with preparations of different doses of simvastatin (0, 0.01, 0.1, 0.25 and 0.5 mg) combined with α‐TCP particles or left empty. The animals were sacrificed at 2, 4 and 8 weeks and analyzed radiologically and histologically. Half of the animals of 4 and 8 weeks were labeled with fluorescence dyes and histomorphometrically analyzed.

Results: Simvastatin doses of 0.25 and 0.5 mg caused inflammation of the soft tissue at the graft site whereas control and other doses did not. The micro‐CT analysis revealed that the α‐TCP with 0.1 mg simvastatin (TCP‐0.1) group yielded significantly higher bone volumes than untreated control group at all three time points (249%, 227% and 266% at 2, 4 and 8 weeks, respectively). The percentage of defect closure, bone mineral content and bone mineral density were also higher in the TCP‐0.1 group than in the other groups.

Conclusion: When combined with α‐TCP particles, 0.1 mg simvastatin is the optimal dose for stimulation of the maximum bone regeneration in rat calvarial defects without inducing inflammation and it could be applied as an effective bone graft material.
Implant stability in relation to osseointegration: an experimental study in the Labrador dog
Authors: Abrahamsson Ingemar , Linder Elena , Lang Niklaus P.
Published: February 2009

Objective: Resonance frequency analysis (RFA) is supposed to determine implant stability. The relation between RFA and the degree of bone‐to‐implant contact (BIC), however, is unclear. The objective of the present experiment was to evaluate RFA values in relation to osseointegration.

Material and methods: In 20 Labrador dogs, all mandibular premolars were extracted bilaterally. After 3 months, four transmucosal screw‐shaped experimental implants were placed in each mandibular premolar region. The implants (12 mm length, Ø 4.1 mm, insertion depth 9 mm) were either SLA surface or turned surface implants. The animals were divided into four groups (five dogs in each group) to study healing following implant installation at 2 h, 4 days, 1, 2, 4, 6, 8 and 12 weeks. Two experimental implants of each type were installed in each edentulous premolar region. A plaque control program was initiated 2 weeks after each implant installation. RFA assessments were performed at the time of implant installation, at one to three occasions during the monitoring period and at the termination of the experiment. At the end of the experiment, the dogs were sacrificed and each implant site was dissected and processed for histological analysis. The results of the histological analysis, i.e. marginal bone level, degree of osseointegration (BIC%) and bone density, were compared with the corresponding Implant Stability Quotient (ISQ) values of the RFA assessment.

Results: No correlations between histological parameters of osseointegration and ISQ values could be identified. Marginal bone level changes, differences in BIC% and bone density were not reflected in the RFA at any time‐point during the 12‐week monitoring period.

Conclusion: The value of RFA to predict implant stability over time and to determine at which time‐point an implant may be exposed to functional load has to be questioned.
Erythroid Kruppel‐like factor (EKLF) is recruited to the γ‐globin gene promoter as a co‐activator and is required for γ‐globin gene induction by short‐chain fatty acid derivatives
Authors: Perrine Susan P. , Mankidy Rishikesh , Boosalis Michael S. , Bieker James J. , Faller Douglas V.
Published: February 2009

Objectives:  The erythroid Kruppel‐like factor (EKLF) is an essential transcription factor for β‐type globin gene switching, and specifically activates transcription of the adult β‐globin gene promoter. We sought to determine if EKLF is also required for activation of the γ‐globin gene by short‐chain fatty acid (SCFA) derivatives, which are now entering clinical trials.

Methods:  The functional and physical interaction of EKLF and co‐regulatory molecules with the endogenous human globin gene promoters was studied in primary human erythroid progenitors and cell lines, using chromatin immunoprecipitation (ChIP) assays and genetic manipulation of the levels of EKLF and co‐regulators.

Results and conclusions:  Knockdown of EKLF prevents SCFA‐induced expression of the γ‐globin promoter in a stably expressed μLCRβprRlucAγprFluc cassette, and prevents induction of the endogenous γ‐globin gene in primary human erythroid progenitors. EKLF is actively recruited to endogenous γ‐globin gene promoters after exposure of primary human erythroid progenitors, and murine hematopoietic cell lines, to SCFA derivatives. The core ATPase BRG1 subunit of the human SWI/WNF complex, a ubiquitous multimeric complex that regulates gene expression by remodeling nucleosomal structure, is also required for γ‐globin gene induction by SCFA derivatives. BRG1 is actively recruited to the endogenous γ‐globin promoter of primary human erythroid progenitors by exposure to SCFA derivatives, and this recruitment is dependent upon the presence of EKLF. These findings demonstrate that EKLF, and the co‐activator BRG1, previously demonstrated to be required for definitive or adult erythropoietic patterns of globin gene expression, are co‐opted by SCFA derivatives to activate the fetal globin genes.
Role of systemic and local administration of selective inhibitors of cyclo‐oxygenase 1 and 2 in an experimental model of periodontal disease in rats
Authors: Queiroz‐Junior C. M. , Pacheco C. M. F. , Maltos K. L. M. , Caliari M. V. , Duarte I. D. G. , Francischi J. N.
Published: February 2009

Background and Objective:  Periodontal disease is an inflammatory condition of tooth‐supporting tissues. Arachidonic acid metabolites have been implicated in development of periodontal disease, especially those derived from the cyclo‐oxygenase (COX) pathway. This study investigated the role of inhibitors of cyclo‐oxygenases (COX‐1 and COX‐2) in a model of periodontal disease in rats.

Material and Methods:  A ligature was placed around the molar of rats. Losses of fiber attachment and of alveolar bone were measured morphometrically in histologically prepared sections. Infiltration of cells into gingival tissue surrounding the ligated tooth was also determined.

Results:  Systemic and local administration of non‐selective and selective COX‐2 inhibitors, preventively, resulted in significant reduction of the losses of fiber attachment and alveolar bone, as well as decreased leukocyte numbers in gingival tissue. Preventive selective inhibition of COX‐1 was as effective as COX‐2 inhibition in reducing local fiber attachment loss and cell migration, but did not prevent alveolar bone loss.

Conclusion:  Our results provide evidence for participation of COX‐1 and COX‐2 in early stages of periodontal disease in rats. Furthermore, local administration of COX inhibitors reduced the signs of periodontal disease to the same extent as systemic treatment. Therapeutic approaches incorporating locally delivered anti‐inflammatory drugs could be of benefit for patients suffering from periodontal disease.
Cigarette smoke condensate stimulates urokinase production through the generation of reactive oxygen species and activation of the mitogen activated protein kinase pathways in human gingival fibroblasts
Authors: Gonzalez R. , Arancibia R. , Cáceres M. , Martínez J. , Smith P. C.
Published: February 2009

Background and Objective:  Tobacco smoking is a significant risk factor for periodontal disease. It has been suggested that smoking may alter connective tissue remodeling in the periodontium. In the present study, we investigated whether cigarette smoke condensate modulates the production of the serine protease urokinase in human gingival fibroblasts.

Material and Methods:  Primary cultures of human gingival fibroblasts were stimulated with cigarette smoke condensate. Urokinase production was evaluated through casein zymography and western blotting. Plasmin activation was assessed by means of a radial diffusion assay. The roles of extracellular signal‐regulated kinase (ERK), c‐Jun N‐terminal kinase (JNK) and reactive oxygen species in cigarette smoke condensate‐stimulated urokinase production were studied using distinct selective inhibitors (SP600125, PD98059, N‐acetyl cysteine). Reactive oxygen species production was determined using a fluorometric assay. Activation of ERK and JNK pathways were evaluated using western blots.

Results:  In gingival fibroblasts, cigarette smoke condensate potently stimulated urokinase production and plasmin activation. Cigarette smoke condensate‐stimulated urokinase production was dependent on the activity of ERK/JNK pathways and was inhibited by the reactive oxygen species scavenger, N‐acetyl cysteine. Cigarette smoke condensate strongly stimulated ERK and JNK phosphorylation and the generation of reactive oxygen species.

Conclusion:  Cigarette smoke condensate stimulates urokinase production and plasmin activation in gingival fibroblasts. Moreover, cigarette smoke condensate‐stimulated urokinase production depends on both the activation of ERK/JNK pathways and on the generation of intracellular reactive oxygen species. These results show that cigarette smoke may alter connective tissue remodeling by inducing production of the urokinase‐type plasminogen activator through specific signaling pathways.
Interleukin‐10 (−592 C/A) and interleukin‐12B (+16974 A/C) gene polymorphisms and the interleukin‐10 ATA haplotype are associated with periodontitis in a Taiwanese population
Authors: Hu K.‐F. , Huang K.‐C. , Ho Y.‐P. , Lin Y.‐C. , Ho K.‐Y. , Wu Y.‐M. , Yang Y.‐H. , Tsai C.‐C.
Published: February 2009

Background and Objective:  Single nucleotide polymorphisms are assumed to be associated with the differential production of cytokines. We evaluated gene polymorphisms of interleukin‐10 (−592C>A, −819C>T and −1082G>A) and interleukin‐12B (+16974) in patients with chronic periodontitis (n = 145) and generalized aggressive periodontitis (n = 65) in comparison with healthy controls (n = 126).

Material and Methods:  Gene promoter polymorphisms were analyzed by polymerase chain reaction with sequence‐specific primers. Genotype and allele frequencies were analyzed using the chi‐square test and logistic regression analysis.

Results:  The interleukin‐10 −592 polymorphism showed significant differences among the three groups (p = 0.0330). The genotype frequencies of the −592 locus between the chronic periodontitis and healthy control groups were significantly different (AC vs. AA: odds ratio = 0.33). The combination ATA/ATA seemed to be associated with susceptibility to generalized aggressive periodontitis (p = 0.0276). Patients with the composite ATA/ACC were less likely to develop chronic periodontitis (p = 0.0248). The CC genotype of interleukin‐12B (+16974) was related to chronic periodontitis (CC vs. AA, p = 0.0211; CC vs. AA+AC, p = 0.0187). The AC heterozygosity of interleukin‐12B was significantly lower in chronic periodontitis vs. healthy controls (p = 0.0500).

Conclusion:  The interleukin‐10 gene polymorphism at position −592C>A may be associated with a lower risk for development of chronic periodontitis. The interleukin‐10 haplotype ATA is associated with generalized aggressive periodontitis. On the other hand, interleukin‐12B genetic variants at position +16974 are associated with susceptibility to chronic periodontitis.
The effect of platelet‐rich plasma on osteoblast and periodontal ligament cell migration, proliferation and differentiation
Authors: Creeper F. , Lichanska A. M. , Marshall R. I. , Seymour G. J. , Ivanovski S.
Published: February 2009

Background and Objective:  Platelet‐rich plasma is used to deliver growth factors, in a safe and convenient manner, for enhancing bone and periodontal regeneration. However, conflicting reports regarding its effectiveness suggest that further study of the relevant cellular mechanisms is required. The aim of this study was to investigate the in vitro effect of platelet‐rich plasma on osteoblasts and periodontal ligament cell function.

Material and Methods:  Various concentrations of platelet‐rich plasma (100, 50, 20 and 10%) and platelet‐poor plasma, obtained from human donors, were applied to primary cultures of human osteoblasts and periodontal ligament cells. [3H]‐Thymidine incorporation, crystal violet staining and MTT assays were utilized to assess DNA synthesis and proliferation. Migration was determined by assessing the cell response to a concentration gradient, while differentiation was assessed using Alazarin Red staining.

Results:  Platelet‐rich plasma and platelet‐poor plasma had stimulatory effects on the migration of both human osteoblasts and periodontal ligament cells. At 24 h, DNA synthesis was suppressed by the application of the various concentrations of platelet‐rich plasma, but over a 5‐d period, a beneficial effect on proliferation was observed, especially in response to 50% platelet‐rich plasma. Platelet‐poor plasma resulted in the greatest enhancement of cellular proliferation for both cell types. At a concentration of 50%, platelet‐rich plasma and platelet‐poor plasma facilitated differentiation of both cell types.

Conclusion:  Platelet‐rich plasma can exert a positive effect on osteoblast and periodontal ligament cell function, but this effect is concentration specific with maximal concentrations not necessarily resulting in optimal outcomes. Platelet‐poor plasma also appears to have the ability to promote wound healing‐associated cell function.
Tooth‐ and Tissue‐Supported Provisional Restorations for the Treatment of Patients with Extended Edentulous Spans
Authors: VASILIOS CHRONOPOULOS , KOURTIS STEFANOS , KATSIKERIS NIKOLAOS , NAGY WILLIAM
Published: February 2009

Dental implants have been used successfully for decades in the treatment of edentulous patients and offer great comfort compared with complete dentures. However, completely edentulous patients or patients with several teeth with poor prognosis that will be all extracted have to be provided with an interim complete denture until the implants have been uncovered. Complete dentures are a less attractive option for the patients because of functional, esthetic, and psychological reasons. The use of complete dentures over implants during the patients' healing period has been associated with numerous complications.

The aim of this paper was to present a new type of provisional restoration supported by hopeless teeth and soft tissues.

CLINICAL SIGNIFICANCE

These provisional restorations can be used during the osseointegration period to avoid the use of a complete denture. The teeth can thus be restored with fixed restorations during the whole osseointegration period to provide better comfort and avoid the psychological stress of using a removable prosthesis. Additionally, the problems associated with dentures over implants or grafts (pressure, implant exposure, etc.) can be eliminated.
Predictable Repair of Provisional Restorations
Authors: HAMMOND BARRY D. , COOPER JERIL R. , LAZARCHIK DAVID A.
Published: February 2009

The importance of provisional restorations is often downplayed, as they are thought of by some as only “temporaries.” As a result, a less‐than‐ideal provisional is sometimes fabricated, in part because of the additional chair time required to make provisional modifications when using traditional techniques. Additionally, in many dental practices, these provisional restorations are often fabricated by auxillary personnel who may not be as well trained in the fabrication process. Because provisionals play an important role in achieving the desired final functional and esthetic result, a high‐quality provisional restoration is essential to fabricating a successful definitive restoration. This article describes a method for efficiently and predictably repairing both methacrylate and bis‐acryl provisional restorations using flowable composite resin. By use of this relatively simple technique, provisional restorations can now be modified or repaired in a timely and productive manner to yield an exceptional result.

CLINICAL SIGNIFICANCE

Successful execution of esthetic and restorative dentistry requires attention to detail in every aspect of the case. Fabrication of high‐quality provisional restorations can, at times, be challenging and time consuming. The techniques for optimizing resin provisional restorations as described in this paper are pragmatic and will enhance the delivery of dental treatment.
From plant–microbe interactions to symbiogenetics: a universal paradigm for the interspecies genetic integration
Authors: Tikhonovich I.A. , Provorov N.A.
Published: February 2009

Beneficial plant–microbe symbioses are based on the integration of genetic material from diverse organisms resulting in formation of superorganism genetic systems. Analysis of their functions and evolution requires the establishment of a new biological discipline, proposed to be called symbiogenetics, which provides a basis for fundamental and applied research of the genetic control over different (symbiotic and biocenotic) biotic interactions. In ecology and agrobiology, the approaches of symbiogenetics are indispensable for optimising the interactions between the plants and the beneficial microbes to be used in ecosystem management and in sustainable crop production in which hazardous fertilisers and pesticides should be replaced by environmentally friendly microbial inoculants.
A Canadian Copyright Narrative
Authors: Gervais Daniel J.
Published: February 2009

Copyright policy, like other major areas of public policy, requires a solid anchoring in fundamental principles. The perceived need to anchor copyright debates in a solid policy context and, hence, to develop a coherent (and hopefully convincing) narrative has been the subject of excellent contemporary research. We are indebted to a number of scholars for their work in this area. The attempt to find normative applications from a historically derived model for copyright is not either. However, the research thus far tends to provide a blurred picture, by espousing justiflcatory theories based on one or many of the following: commercial and personal Interests of authors, understood as property and/or liability rules; commercial interests of publishers and other “rights holders”; and/or the social costs of overprotection and the related economic‐driven search for an optimal point of protection. This article looks at pieces in the Canadian narrative puzzle and tries to present a faithful picture of its current stage of evolution. To do so, however, a detour via England is required, because that is whence the soil from Which the Canadian narrative comes. This historical detour will be the focus of Part 1. Part III will suggest a path for the next stages of the Canadian narrative that is both consistent with international norms and hopefully useful in moving the debate forward. The part ends with a brief look at the impact that the linkage with trade rules may have on copyright.
Determination of steroid hormones in whale blow: It is possible
Authors: Hogg C. J. , Rogers T. L. , Shorter A. , Barton K. , Miller P. J. O. , Nowacek D.
Published: February 2009

Abstract

The feasibility of using analysis of hormone content of whale blow samples to assess reproductive function is addressed. A suitable collection method and analytical technique using liquid chromatography‐mass spectrometry (LC‐MS) has been developed. Blow samples were collected opportunistically from free‐ranging humpback whales (Megaptera novaeangliae) (n= 35) and North Atlantic right whales (Eubalaena glacialis) (n= 18) using a 13‐m carbon fiber pole with a collection device. Samples were analyzed for the presence of testosterone and progesterone using a 55% isocratic gradient with LC‐MS. Testosterone was detected in four humpback whale samples and eight northern right whale samples. Progesterone was detected in seven humpback whale samples and eight northern right whale samples. This is the first documented use of lung mucosa to determine the presence of reproductive hormones in any free‐swimming cetacean and may provide a novel non‐invasive technique to quantify the hormonal condition of free‐swimming animals that spend brief periods of time at the water's surface.
Characteristics of 11 polymorphic microsatellite markers in the red imported fire ant, Solenopsis invicta Buren
Authors: GARLAPATI RAJESH B. , CROSS DAVID C. , PERERA OMATHTHAGE P. , CAPRIO MICHAEL A.
Published: February 2009

We have characterized 11 polymorphic microsatellite loci in the invasive ant Solenopsis invicta. Primer pairs were evaluated on fire ants collected from monogyne mounds in Lauderdale County, Mississippi. The observed and effective number of alleles ranged from two to six and from 1.31 to 2.64, respectively. The observed and expected heterozygosity values ranged from 0.1613 to 0.7826 and from 0.1491 to 0.6242, respectively. The polymorphism information content of the microsatellites ranged from 0.1482 to 0.6208. Probability tests indicated significant deviations from the Hardy–Weinberg equilibrium at three loci. Pairwise tests did not detect linkage disequilibrium between any pair of loci.
Slit‐lamp‐adapted optical coherence tomography for assessment of an overhanging filtering bleb
Authors: Prata Tiago Santos , De Moraes Carlos Gustavo V. , Palmiero Pat‐Michael , Tello Celso , Liebmann Jeffrey , Ritch Robert
Published: February 2009

Acta Ophthalmol. 2010: 88: 910–911
Antioxidant Status and Biomarkers of Oxidative Stress in Dogs with Lymphoma
Authors: Winter J.L. , Barber L.G. , Freeman L. , Griessmayr P.C. , Milbury P.E. , Blumberg J.B.
Published: February 2009

Background:Oxidative stress might play a role in carcinogenesis, as well as impacting morbidity and mortality of veterinary cancer patients. The purpose of this study was to evaluate antioxidant concentrations and biomarkers of oxidative stress in dogs with newly diagnosed lymphoma before treatment and once in remission, with comparison with healthy controls.

Hypothesis:Dogs with lymphoma have increased oxidant and reduced antioxidant concentrations compared with healthy controls, and that these abnormalities normalize once remission is achieved.

Animals:Seventeen dogs with lymphoma and 10 healthy controls.

Methods:Prospective, observational study. Measures of oxidative stress [malondialdehyde and total isoprostanes (isoP)] and antioxidants [α‐tocopherol, γ‐tocopherol, oxygen radical absorbance capacity (ORAC), and glutathione peroxidase (GSHPx)] were assessed in dogs with newly diagnosed lymphoma before treatment compared with healthy control dogs. The same parameters were measured in the dogs with lymphoma on week 7 of the chemotherapy protocol when all dogs were in remission.

Results:At baseline, dogs with lymphoma had significantly lower α‐tocopherol (P<.001) and γ‐tocopherol (P= .003) but higher GSHPx (P= .05), ORAC (P= .001), and isoP (P< .001) compared with healthy controls. In the dogs with lymphoma, α‐tocopherol concentrations were higher (P= .005) and ascorbic acid were lower (P= .04) after treatment.

Conclusions and Clinical Importance:Results suggest that dogs with lymphoma have alterations in oxidant and antioxidant concentrations and that the status of some of these biomarkers normalize after remission. Further studies are warranted to determine whether antioxidant interventions to correct these are beneficial in the treatment of canine lymphoma.
Dynamic Effects of Mandrel/Tubular Interaction on Downhole Solid Tubular Expansion in Well Engineering
Authors: Seibi A. C. , Karrech A. , Pervez T. , Al-Hiddabi S. , Al-Yahmadi A. , Al-Shabibi A.
Published: February 2009

The expansion process subjects a solid tubular to large plastic deformations leading to variations in tubular thickness and length, which may result in premature and unexpected failures. It was noticed that the expansion process induces wall thickness imperfections due to excessive local plastic deformation as a result of mandrel sticking and slipping relative to the expanded tubular; such irregularities increase the probability of failure. Mandrel sticking may be the result of lack of enough lubrication, tubular surface irregularities, and the presence of welded and/or threaded connections, which require higher drawing force to push the mandrel forward. When the drawing force required to overcoming the maximum static friction and the mandrel forward motion is assured, the mandrel slips relative to the expanded tubular. This “stick-slip” phenomenon results in mandrel oscillations that affect the tubular response in terms of further reduction in thickness and may jeopardize the tubular capacity under normal operating field conditions. Therefore, the present work studies the mandrel dynamics and their effect on the tubular structural response. A mathematical model, which is an extension of the quasistatic tubular expansion analysis, has been developed to describe the dynamic friction effects of the stick-slip phenomenon. A special case of tubular expansion consisting of 25% expansion ratio of a 4/12 in. (114.3 mm) liner hanger was considered. It was found that the level of mandrel oscillations is in the order of 1–2 mm around its equilibrium position resulting in tubular thickness reduction of approximately 9% on top of its variation caused by the steady state expansion process. This increase in thickness reduction may affect the postexpansion collapse strength of the tubular.
Steady State Productivity Equations for a Vertical Well in Anisotropic Sector Fault, Channel, and Rectangular Reservoirs
Authors: Lu Jing , Tiab Djebbar , Owayed Jalal Farhan
Published: February 2009

This paper presents steady state productivity equations for a fully penetrating vertical well in the following three anisotropic systems: (a) sector fault, (b) channel, and (c) rectangular reservoir using a uniform line sink model. The new equations, which are based on conformal mapping method, are simple, accurate, and easy to use in field practice. If the well is in a sector fault reservoir, the productivity is a function of the angle of the sector, wellbore location angle, off-vertex distance, and drainage radius. If the well is in a channel reservoir with two parallel impermeable lateral boundaries, well flow rate reaches a maximum value when the well is located in the middle of the channel width. If the well is in a rectangular reservoir with constant pressure lateral boundaries, a new equation is provided to calculate the productivity of the well arbitrarily located in the anisotropic reservoir for the case where the flow rate of an off-center well is bigger than that of a centered well. It is concluded that, for a vertical well, different steady state productivity equations should be used in different reservoir geometries.
Solar Hydrogen Production Integrating Low-Grade Solar Thermal Energy and Methanol Steam Reforming
Authors: Hong Hui , Liu Qibin , Jin Hongguang
Published: February 2009

In this paper, a novel approach of middle-temperature solar hydrogen production using methanol steam reforming is proposed. It can be carried out at around 200–300°C, much lower than the temperatures of other solar thermochemical hydrogen production. For the realization of the proposed solar hydrogen production, solar experiments are investigated in a modified 5 kW solar receiver/reactor with one-tracking parabolic trough concentrators. The feature of significantly upgrading the energy level from lower-grade solar thermal energy to higher-grade chemical energy is experimentally identified. The interaction between the hydrogen yield and the energy-level upgrade of solar thermal energy is clarified. Also, this kind of solar hydrogen production is experimentally compared with methanol decomposition. The preliminarily economic evaluation of the hydrogen production is identified. As a result, in the solar-driven steam reforming, the thermochemical efficiency of solar thermal energy converted into chemical energy reached up to 40–50% under a mean solar flux of 550–700 W/m2, and exceeding 90% of hydrogen production is achieved, with about 70% higher than that of methanol decomposition. The thermochemical performance of solar-driven methanol steam reforming experimentally examined at around 200–300°C for hydrogen production may be competitive with conventional methane reforming. The promising results obtained here indicate that the proposed solar hydrogen production may provide the possibility of a synergetic process of both high production of hydrogen and effective utilization of solar thermal energy at around 200–300°C.
Thermic Influence on the Dynamics of Pneumatic Servosystems
Authors: Sorli Massimo , Gastaldi Laura
Published: February 2009

The gain values that can be imposed in pneumatic system controllers are bounded to the restricted actuator bandwidth. That limitation, with low damping and stiffness due to the air compressibility, seriously affects accuracy and repeatability when varying payloads or supply pressures. For modeling and control intents, a correct characterization of the pneumatic actuator natural frequency is indispensable. The aim of the paper is to evaluate how heat exchange process affects the proper characteristics of pneumatic drivers and, in particular, their pneumatic stiffness. To this purpose dynamic stiffness had been studied both by imposing in the cylinder’s chambers a polytrophic transformation of the fluid with a prefixed index and by employing energy equations. Numerical results obtained by implementing the two formulations for different working conditions are reported and compared in order to point out the ranges in which they overlap, and hence both approaches produce accurate results, or the ones in which there is a difference, and then it is necessary to consider the temperature dynamics.