bluuebunny/crossref_metadata_2025_split huggingface dataset:
Optimal ball packings for crystallographic groups of the cubic crystal system and their Dirichlet-Voronoi cells
Authors: Prok István , Szirmai Jenö 
Published: October 2005

Abstract
In this paper we look for densest ball packings of Euclidean space E3 to given symmetry groups. We restrict our investigation to the 36 space groups of the cubic crystal system, and we search for only those packings where the group acts simply transitively on the balls. In order to find the centre of a ball and its radius for the case of an optimal packing we will apply an algorithm and the corresponding computer program, which was developed by the second author [21, 12]. In the list of our results we will give the coordinates of the ball centre and the radius, moreover, we will compute the density of the optimal packing and display the corresponding D-V cell for each space group above (see also [14, 15]).
Applications of injectable polymeric implants for protein and DNA delivery
Authors: Eliaz Rom E. , Kost Joseph 
Published: October 2005

AbstractWe developed a monolithic protein and gene delivery system where an implant is formed following injection to the site of need. This implant can be used for the controlled release of small molecules, proteins, and genes over a 2‐month period. As an example of the protein delivery system, sustained release of the soluble tumor necrosis factor (TNF) receptor (sp55‐R) from the injectable implant was used as a long‐term protection device against the harmful pathological effects of TNF. When the system is used to release DNA, a robust and prolonged gene expression at the site of need can be obtained. Furthermore, when the system was used for controlled delivery of the appropriate plasmid DNA, it resulted in the sustained expression of luciferase, the persistent appearance of secreted alkaline phosphatase in the serum, and small blood vessel formation in the vicinity of the implant from the delivery of the development endothelial locus‐1 gene. This delivery system involves simple preparation procedures and can be injected directly into the site, and therefore should be a useful approach to drug delivery, protein therapy, and plasmid‐based gene transfer for vaccination and tissue engineering.
Hypoxia and Serum Deprivation-Induced Apoptosis in Mesenchymal Stem Cells
Authors: Zhu Weiquan , Chen Jinghai , Cong Xiangfeng , Hu Shengshou , Chen Xi 
Published: October 2005

Abstract
In recent years, the understanding that regeneration progresses at the level of the myocardium has placed stem cell research at the center stage in cardiology. Despite an increasing interest in cell transplant research, relatively little is known about the biochemical regulation of the stem cell itself after transplantation into an ischemic heart. We demonstrated here, using rat mesenchymal stem cells (MSCs), that cells undergo caspase-dependent apoptosis in response to hypoxia and serum deprivation (SD), which are both components of ischemia in vivo. In particular, the treated cells exhibited mitochondrial dysfunction, including cytochrome C release, loss in ΔΨm, and Bax accumulation, but in a p53-independent manner. Although the cells treated by hypoxia/SD possess the activity of caspase-8, zIEDT-fmk, a specific caspase-8 inhibitor, failed to inhibit cell apoptosis induced in our system. Taken together, our findings indicate that MSCs are sensitive to hypoxia/SD stimuli that involve changes in mitochondrial integrity and function but are potentially independent of caspase-8.
Gingipain‐Specific IgG in the Sera of Patients With Periodontal Disease Is Necessary for Opsonophagocytosis of Porphyromonas gingivalis
Authors: Gibson Frank C. , Savelli Juan , Van Dyke Thomas E. , Genco Caroline Attardo 
Published: October 2005

Background: Porphyromonas gingivalis is a primary etiologic agent of generalized aggressive periodontitis (GAgP), and gingipains, a group of cysteine proteinases, are critical virulence factors expressed by this organism. GAgP patients develop specific antibodies to gingipains; however, the function of these antibodies in the clearance of P. gingivalis infection is poorly understood.Methods: In this study, we defined the levels of gingipain‐specific antibodies in GAgP patient sera and examined the ability of gingipain‐specific antibodies to facilitate opsonophagocytosis of P. gingivalis by human polymorphonuclear leukocytes (PMNs) using a fluorescent phagocytosis assay.Results: GAgP patient sera possessed elevated levels of P. gingivalis‐, arginine‐gingipain (Rgp)A‐, RgpB‐, and lysine‐gingipain (Kgp)‐specific IgG (Kgp > RgpA > P. gingivalis > RgpB). Adsorption of GAgP sera with P. gingivalis whole organisms, RgpA, RgpB, and Kgp conjugated to sepharose beads reduced opsonophagocytosis of P. gingivalis by PMNs.Conclusions: Our studies demonstrate that GAgP patient sera possess elevated levels of P. gingivalis‐ and gingipain‐specific IgG. Furthermore, we show that gingipain antibodies promote uptake of P. gingivalis by PMNs, and our data suggest that gingipain‐specific antibodies may be important for the control of P. gingivalis infections.
Regenerative Potential of Platelet‐Rich Plasma Added to Xenogenic Bone Grafts in Peri‐Implant Defects: A Histomorphometric Analysis in Dogs
Authors: Sánchez Andrés R. , Sheridan Phillip J. , Eckert Steven E. , Weaver Amy L. 
Published: October 2005

Background: The purpose of this investigation was to evaluate the regenerative influence of platelet‐rich plasma (PRP) added to xenogenic bone grafts on bone histomorphometric parameters in a dog model.Methods: Ninety endosseous dental implants were inserted in the mandibles of nine hound dogs. Mesial and distal 3‐wall peri‐implant defects were surgically created adjacent to the implants. Defects were randomly assigned to three groups: demineralized freeze dried bone with platelet‐rich plasma (DFDB + PRP), DFDB alone, and no treatment (NT). Animals were sacrificed at 1, 2, and 3 months according to a previously established randomization schedule, and specimens were subjected to histomorphometric analysis. Percentages of bone area inside the implant threads (BiIT), bone‐to‐implant contact (BIC), and bone area outside implant threads (BoIT) were recorded. Treatment effects were evaluated using analysis of variance models.Results: The effect of the three treatments on the outcome measures did not differ significantly by healing time (P >0.05 for the healing time by treatment interaction). However, the average (standard deviation) percentage of BIC and BoIT was significantly different between the treatment groups. In particular, the average percentage of BIC differed between peri‐implant defects treated with DFDB + PRP (33.8% [11.0]) and those treated with DFDB alone (28.5% [10.8]; P = 0.042), as well as those in the NT group (27.9% [11.0]; P = 0.024). Furthermore, the average percentage of BoIT differed significantly between defects treated with DFDB + PRP compared to defects in the NT group (51.6% [12.2] versus 43.3% [10.3]; P = 0.005). There was borderline evidence to suggest that the average percentage of BiIT and BIC was significantly different depending on the length of the healing time (P = 0.054 and P = 0.085, respectively).Conclusion: This study found that the addition of PRP to xenogenic bone grafts demonstrated a low regenerative potential in this animal model.
The Effects of Three Oral Sprays on Plaque and Gingival Inflammation
Authors: Bozkurt F. Yesim , Öztürk Mine , Yetkin Zuhal 
Published: October 2005

Background: The aim of this clinical trial was to compare the effects of three oral sprays containing chlorhexidine (CHX), benzydamine hydrochloride (B‐HCl), and CHX plus B‐HCl (CHX/B‐HCl) on plaque and gingivitis.Methods: Fifty‐one periodontally healthy volunteers, randomly divided into three spray groups, refrained from all mechanical oral hygiene measures for 7 days and, instead, used one of the randomly assigned sprays twice daily. The plaque index (PI), gingival index (GI), and gingival bleeding time index (GBTI) were assessed at days 0 and 7. Side effects were also evaluated.Results: In all groups, PI, GI, and GBTI showed significant increases from the baseline to day 7. There were no significant side effects for B‐HCl spray and CHX spray at day 7, but, for CHX/B‐HCl, burning sensation significantly increased from the baseline. For all parameters, there were significant differences between B‐HCl and CHX/B‐HCl and between B‐HCl and CHX, but no significant differences were observed between CHX/B‐HCl and CHX. In addition, a significant difference was found between CHX/B‐HCl and CHX with regard to burning sensation.Conclusions: These results indicate that both CHX and CHX/B‐HCl sprays have equal clinical effectiveness, but only B‐HCl spray has less anti‐plaque and anti‐gingivitis effects. Furthermore, CHX/B‐HCl spray causes more side effects.
Involvement of Porphyromonas gingivalis fimA Genotype in Treatment Outcome Following Non‐Surgical Periodontal Therapy
Authors: Fujise Osamu , Miura Mayumi , Hamachi Takafumi , Maeda Katsumasa 
Published: October 2005

Background: Porphyromonas gingivalis is considered a critical pathogen in periodontal diseases. It is classified into six genotypes based on diversity of the fimA gene encoding fimbrillin. The present study evaluated the involvement of the fimA genotype in treatment outcome following non‐surgical periodontal therapy.Methods: Chronic periodontitis patients were enrolled in this study; all received clinical and microbiological examinations at baseline. The detection of subgingival species and identification of P. gingivalis fimA genotypes were performed using polymerase chain reaction based methods. In total, 160 P. gingivalis positive sites with bleeding on probing (BOP) and a probing depth of ≥4 mm were accepted. They were followed up after scaling and root planing.Results: Longitudinal investigation indicated that fimA type I positive sites at baseline were followed by a significantly higher frequency of persistent BOP after treatment than type I negative sites (51.6% versus 27.9%), while types Ib and II were not. Type I positive sites also showed more persistence of Tannerella forsythensis and P. gingivalis after treatment than type I negative sites. In post‐treatment investigation, type I positive sites showed higher frequencies of BOP and T. forsythensis detection than type I negative sites (77.8% versus 43.5% and 100% versus 76.1%, respectively).Conclusions: BOP in initially type I positive sites showed little improvement with treatment, and the combined persistence of fimA type I and T. forsythensis seemed to be involved in this poor treatment outcome. The present study demonstrated the potential of P. gingivalis fimA type I as a predictor of persistent BOP after treatment.
Periodontal Regeneration With Peptide‐Enhanced Anorganic Bone Matrix in Particulate and Putty Form in Dogs
Authors: Vastardis Sotirios , Yukna Raymond A. , Mayer Elizabeth T. , Atkinson Brent L. 
Published: October 2005

Background: Peptide‐enhanced (using the peptide 15 [P‐15] synthetic peptide) anorganic bone matrix (ABM) particulate (PPart) grafts have demonstrated clinical and histologic success in human periodontal defects. Dispersion of ABM/P‐15 in sodium hyaluronate carrier (PPutty) improves the handling properties of the graft material. The healing of ABM/P‐15 particulate and ABM/P‐15 putty was compared in critical‐sized fenestration defects in 16 mongrel dogs.Methods: After full thickness flap reflection, 7 mm diameter fenestrations were made with a trephine in the mid‐root of both maxillary canines in each dog. Bone, periodontal ligament, and cementum were removed as completely as possible with hand root planing within the trephine‐produced notches. By random allocation, each defect was filled with PPart or PPutty, and the flaps were closed with sutures. One dog contributing two defects served as a negative control. Block sections were retrieved at 3 and 8 weeks for histologic processing. Three 6‐μ step serial sections in the center of the defects were used for analysis. Parameters measured included the original length of the wound, linear amount of periodontal regeneration including new cementum, bone and connective tissue, and area measurements of new bone and remaining particles. PPutty and PPart results were compared for significant differences using the Wilcoxon rank sum test.Results: Clinical healing was uneventful in all cases. There was no evidence of inflammation or adverse tissue reactions with either material. The controls showed minimal regeneration at the periphery of the defect. Histomorphometric evaluation of the grafted defects revealed the following: at 3 weeks, there was minimal new bone formation (occupying 4.2% of the grafted area for the PPutty and 1.2% for the PPart). The grafted particles occupied 21.2% and 35.6% of the area for the PPutty and PPart, respectively (P = 0.039). At 8 weeks, there was a tendency for greater new bone formation compared to 3 weeks with both materials. There was significantly more new bone with the PPutty (49.3%) compared to the PPart (14.8%) (P = 0.045). The grafted particles occupied 7.9% and 17% of the grafted area for the PPutty and PPart, respectively (no significant difference). There were no significant differences for any of the linear measurements. ABM/P‐15 PPutty had superior handling characteristics.Conclusions: Both ABM/P‐15 materials yielded satisfactory healing and resulted in the greater regeneration of fenestration defects in dogs at 8 weeks compared to controls. In addition, AMB/P‐15 putty resulted in more bone formation compared to ABM/P‐15 particulate.
Biological Factors Involved in the Osseointegration of Oral Titanium Implants With Different Surfaces: A Pilot Study in Minipigs
Authors: Schierano Gianmario , Canuto Rosa Angela , Navone Roberto , Peirone Bruno , Martinasso Germana , Pagano Marco , Maggiora Marina , Manzella Carlo , Easton Michael , Davit Annalisa , Trombetta Antonella , Amedeo Stefano , Biolatti Bartolomeo , Carossa Stefano , Preti Giulio 
Published: October 2005

Background: The stability of titanium implants is determined by the rigid load‐bearing connections that are formed by the bone, a process that involves a complex network of cells, pro‐ and anti‐inflammatory mediators, and growth factors. The osseointegration processes at the interfaces of machined and porous implants were studied using molecular and histological techniques.Methods: Two machined and two porous titanium implants were inserted into the tibiae of four minipigs. The animals were sacrificed at 15, 30, 60, and 90 days post‐implantation. The levels of bone morphogenetic protein (BMP)‐4, transforming growth factor (TGF)‐β1, and tumor necrosis factor (TNF)‐α were quantified in the peri‐implant osseous samples. The levels of interleukin (IL)‐1β, IL‐6, IL‐10, and TNF‐α in the serum were also assessed.Results: Histomorphological analysis showed evidence of bone ossification around the porous implant at 60 days. Surrounding the machined implants, highly sclerotic fibrous pads started the healing response at 90 days, and the levels of TGF‐β1 and BMP‐4 began to increase at 60 days, at which time bone ossification around the porous implants was already evident. TNF‐α was not present in the bone next to the implants. The serum levels of cytokines IL‐1β, IL‐6, and IL‐10 were not increased. The serum level of TNF‐α increased during the healing process.Conclusions: We observed that the levels of BMP‐4 and TGF‐β1, which play essential roles in the osteogenesis process, increased earlier around the porous implants than around the machined implants. Similarly, the ossification process was initiated earlier at the surfaces of the porous implants than at the surfaces of the machined implants.
Overweight and Obesity as Risk Indicators for Periodontitis in Adults
Authors: Dalla Vecchia Caroline Formolo , Susin Cristiano , Rösing Cassiano Kuchenbecker , Oppermann Rui Vicente , Albandar Jasim M. 
Published: October 2005

Background: Developed and developing countries are facing an obesity epidemic with various health consequences. Few studies have addressed the relationship between obesity and periodontal health. The present study assessed the association of overweight and obesity with periodontitis in Brazilian adults.Methods: A representative probability sample comprising 706 subjects aged 30 to 65 years from south Brazil was examined clinically and using a structured interview. Overweight and obesity were assessed by body mass index (BMI) using the World Health Organization (WHO) criteria. Individuals with ≥30% teeth with attachment loss ≥5 mm were classified as having periodontitis. Statistical analysis accounted for survey design, and separate analyses were performed for non‐smokers.Results: In this population, 60% and 65% of males and females, respectively, were overweight or obese. Periodontitis was observed in 50.7% and 35.3% of males and females, respectively. The percentage of males with periodontitis was similar in the overweight/obese individuals compared to those with normal weight. In females, there was a positive correlation between the BMI index and the occurrence of periodontitis, with a significantly (P <0.05) higher prevalence of periodontitis in obese than in normal weight females. The multivariable analysis showed that obese females were significantly more likely (odds ratio = 2.1) to have periodontitis than normal weight females. A separate analysis for non‐smokers showed that obese females were approximately 3.4 times more likely to have periodontitis than the normal BMI group. There were no significant differences in the prevalence of periodontitis between BMI groups among smokers of both genders and in male non‐smokers.Conclusions: Obesity was significantly associated with periodontitis in adult, non‐smoker women. Overweight was not significantly associated with periodontitis. Smoking may attenuate the association of periodontitis with obesity.
Prostaglandin Production by Human Gingival Fibroblasts Inhibited by Triclosan in the Presence of Cetylpyridinium Chloride
Authors: Kim Young Joon , Rossa Carlos , Kirkwood Keith L. 
Published: October 2005

Background: The effect of triclosan plus the cationic detergent cetylpyridinium chloride (CPC) was evaluated for prostaglandin inhibition in human gingival fibroblasts. Since triclosan has previously been shown to inhibit proinflammatory cytokine induced prostaglandin E2 (PGE2) production, we wanted to determine if triclosan, in the presence of CPC, could enhance these effects.Methods: Initial studies determined that both triclosan and CPC were cytotoxic to human gingival fibroblasts in concentrations exceeding 1.0 μg/ml for either agent longer than 24 hours in a tissue culture. Therefore, subsequent studies measuring prostaglandin biosynthesis and cyclooxygenase (COX)‐1 and COX‐2 mRNA expression were performed in concentrations and times that did not significantly affect cell viability.Results: PGE2 biosynthesis was dose dependently inhibited by both triclosan and triclosan and CPC when challenged by tumor necrosis factor (TNF)‐α or interleukin (IL)‐1β. At pharmacologically relevant concentrations, triclosan and CPC inhibited IL‐1β‐induced PGE2 production to a greater extent than triclosan alone (P = 0.02). Moreover, enhanced COX‐2 mRNA repression was observed with triclosan and CPC in comparison to triclosan alone in IL‐1β and TNF‐α stimulated cells. No effect on COX‐1 gene expression was observed. Further analysis of cell signaling mechanisms of triclosan and CPC indicates that nuclear factor‐kappa B (NF‐κB) and not p38 mitogen‐activated protein kinase (MAPK) signaling may be impaired in the presence of triclosan and CPC.Conclusion: This study indicates that triclosan and CPC are more effective at inhibiting PGE2 at the level of COX‐2 gene regulation, and this combination may offer a potentially better anti‐inflammatory agent in the treatment of inflammatory lesions in the oral cavity.
Biological Evaluation of Chitosan Nanofiber Membrane for Guided Bone Regeneration
Authors: Shin Seung‐Yun , Park Ho‐Nam , Kim Kyoung‐Hwa , Lee Myung‐Hee , Choi Young Suk , Park Yoon‐Jeong , Lee Yong‐Moo , Ku Young , Rhyu In‐Chul , Han Soo‐Boo , Lee Seung‐Jin , Chung Chong‐Pyoung 
Published: October 2005

Background: Chitosan is known as a biodegradable and non‐toxic natural polymer that enhances wound healing and bone formation. The aims of this study are to evaluate the biocompatibility of chitosan nanofiber membranes and to examine the effect of the chitosan nanofiber membranes on bone regeneration in rabbit calvarial defects.Methods: In vitro cell proliferation tests using human osteosarcoma cell line MG63 and reverse transcription‐polymerase chain reaction (RT‐PCR) to evaluate the expression of alkaline phosphatase (ALP), collagen, osteocalcin (OCN), and GAPDH were done on chitosan nanofiber membranes. Chitosan nanofiber membranes were implanted in subcutaneous connective tissue and observed for 2, 4, and 6 weeks in rats. Ten‐millimeter diameter round cranial defects were made in rabbits and covered by chitosan nanofiber membranes for 4 weeks. Specimens were decalcified and observed by a light microscope.Results: MG63 cells proliferated for 28 days on the chitosan nanofiber membranes and expressed ALP, collagen, OCN, and GAPDH at 2 weeks. Chitosan nanofiber membranes that were grafted into rat subcutaneous tissue maintained their shape and space for bone regeneration for as long as 6 weeks. No inflammation could be seen on the membrane surface or in the surrounding tissues. In the rabbit calvarial defects, new bone filled the defects and fused to the original old bone in 4 weeks.Conclusions: The biocompatibility of the chitosan nanofiber membrane was confirmed, with enhanced bone regeneration and no evidence of an inflammatory reaction. This experiment shows that the novel biodegradable chitosan nanofiber membrane may be useful as a tool for guided bone regeneration.