bluuebunny/crossref_metadata_2025_split huggingface dataset:
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

AbstractBackground: 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

AbstractObjective: 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

AbstractObjectives:  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

ABSTRACTDental 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 SIGNIFICANCEThese 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

ABSTRACTThe 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 SIGNIFICANCESuccessful 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

AbstractBeneficial 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.
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

AbstractThe 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

AbstractWe 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.
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.