bluuebunny/crossref_metadata_2025 huggingface dataset:
Citric acid burnishing of dentinal root surfaces
Authors: Sterrett John D. , Murphy H. Joseph
Published: December 2005

Abstract The integrity of formalin‐fixed periodontally diseased root surfaces was assessed following root planing to dentin and citric acid application. Extracted human teeth (fixed in 10% formalin), with crowns removed, were vertically sectioned in half. A horizontal groove on each proximal surface marked the extent of attachment loss. The diseased root surface was vigorously root planed to expose dentin. Cotton pellets, soaked in a saturated solution of citric acid, were either “placed” (control) or “burnished” (vigorously rubbed using root planing pressure) (experimental) on the prepared root surface for 5 min. Pellets were changed 2 times/min. The teeth were fixed and prepared for scanning electron microscope viewing and photography. A representative print was selected for each specimen. To confirm differences between test and control groups, untrained raters were asked to perform 2 sorting exercises. First, they were asked to sort the representative photographs of each specimen into 2 piles based on surface characteristics. Second, they were asked to choose from pairs of photographs, representing matched specimens, the one photograph which appeared to have the greatest collagen surface area. The surfaces of experimental specimens revealed patent dentinal tubules and an inter tubular area with a very distinct “shag carpet” appearance of deeply tufted collagen fibrils. Control samples also exhibited open dentinal tubules, yet the inter tubular surface displayed a “matted collagen” surface. Results of the 2 sorting exercises confirm that burnishing of formalin‐fixed dentin root surfaces for 5 min with cotton pellets soaked in a saturated solution of citric acid consistently produces a distinct tufted collagen fibril surface. In addition, this surface consistently appears to have exposed more collagen surface area than matched controls. It is proposed that the citric acid “burnishing” technique described removes more inorganic material through a combined mechanical/chemical process while fluffing and separating the entangled fixed dentin collagen. The effect citric acid has on the organic component of native dentin is raised. The clinical significance of these results is discussed.
Effects of subgingival irrigation on A. actinomycetemcomitans
Authors: Wikesjö Ulf M. E. , Reynolds Homer S. , Christersson Lars A. , Zambon Joseph J. , Genco Robert J.
Published: December 2005

Abstract The effects of repeated subgingival irrigation on Actinobacillus actinomycetemcomitans was examined. 24 periodontal pockets harboring A, actinomycetemcomitans in 3 juvenile and 4 adult periodontitis patients were studied. The protocol included bi‐weekly subgingival irrigation with hydrogen peroxide of the periodontal sites until the micro‐organism was no longer detected by selective culture, or for 6 months. A. actinomycetemcomitans was gradually suppressed to below detection following the irrigation regime and could no longer be detected in 46% of the sites at completion of the irrigation protocol. The sites were microbiologically re‐examined 5 months after cessation of the irrigation regime. A. actinomycetemcomitans re‐occurred in only 2 of the sites from which it had originally been suppressed below detection. The results indicate: (1) that the irrigation regime tested has some potential to suppress A. actinomycetemcomitans in periodontal pockets; (2) that the effect of the irrigation protocol generally lasted for 5 months; (3) that the reduction rate of A. actinomycetemcomitans to below detectable levels seems related to the initial number of cultivable bacteria from the periodontal pocket.
A retrospective radiographic study of alveolar bone loss in the primary dentition in patients with localized juvenile periodontitis
Authors: Sjödin Bengt , Crossner Claes‐Göran , Unell Lennart , Östlund Peter
Published: December 2005

Abstract Lately, it has been questioned whether localized juvenile periodontitis (LJP) is restricted to the permanent dentition, or if it sometimes might have a prepubertal onset, involving the primary dentition. To clarify this question, 17 patients with LJP, together with 17 non‐LJP matched controls, were retrospectively examined for radiographic signs of alveolar bone destruction in their primary dentitions. All LJP subjects but one showed localized marginal bone loss, whereas no bone loss was observed among the controls. The results suggest that at least some cases of LJP start in the primary dentition prior to the involvement of the permanent teeth.
Histological and clinical parameters of human gingiva following 3 weeks of chemical (chlorhexidine) or mechanical plaque control
Authors: Brecx M. C. , Liechti T. , Widmer J. , Gehr P. , Lang N. P.
Published: December 2005

Abstract The aim of the present study was to compare stereologically the histo‐pathologic variations following 3 weeks of chemical (chlorhexidine) or mechanical plaque control. 18 students and denial hygienists volunteered for this investigation. After prophylaxis, they performed optimal oral hygiene to reach mean plaque and gingival indices approaching. 0.Six of them then performed mechanical plaque control of 3 weeks (control), while the other 12 rinsed 3 times daily with a 0.12% chloridixidine solution (test). At days 0 and 21. the plaque index (PH), the gingival index (Gl) and the gingival exudate flow rate (GEFR) were assessed and biopsies were obtained from buccal sites. Point‐counting procedures were performed at 2 different levels of magnification on light microscopic sections to estimate the volume fractions of epithelium, infiltrated and non‐infiltrated connective tissue, and collagen. The relative numbers of fibroblasts, polymorphonuclear neutrophils, lymphocytes, plasma cells, macrophages and mast cells were estimated by counting the number of nuclear profiles of these cells in a specific connective tissue area adjacent to the apical termination of the junctional epithelium. After 21 days, the PIIs of the test subjects were significantly higher than the PIIs of the controls, but their GI were similar. At the end of the experimental period, the various volume fractions and %s of cell profiles remained stable with the exception of an increase in the %s of lymphocytes in the test group. This study has shown that, clinically as well as histologically, the daily use of chlorhexidine for a 3‐week period is equally effecient as optimal mechanical tooth cleaning in maintaining a healthy gingiva in the buccal sites investigated.
Dentine hypersensitivity
Authors: Absi E. G. , Addy M. , Adams D.
Published: December 2005

Abstract Studies of extracted teeth have shown that teeth exhibiting dentine hypersensitivity have larger numbers of widened dentinal tubules at the dentine surface compared to non‐sensitive teeth. Many compounds used in the treatment of dentine hypersensitivity are thought to achieve therapeutic benefit by tubule occlusion, but there has been almost no attempt to prove such action in vivo. These studies systematically determined whether the dentine surface could be evaluated non‐invasively. by a scanning electron microscopic replica technique. Employing a silicone rubber impression method in vitro, the surface detail of dentine could be accurately replicated, with surface scratches, tubules and intratubular structures on the original reproduced on the replica. With attention to method, similar accuracy was achieved in vivo, particularly when tubules were open on the dentine surfaces of the original. The method would appear useful for the study of the dentine surface in cases of dentine hypersensitivity and could prove the first objective method of studying the effects of treatment, agents used in the treatment of this painful condition.
Hormonal influences on gingival tissue: relationship to periodontal disease
Authors: Sooriyamoorthy M. , Gower D. B.
Published: December 2005

Abstract It is the purpose of this review to survey the influence of corticosteroids, androgens, oestrogens and progesterone on gingival tissues and to show the relationship of such influences to periodontal disease. The clinical changes seen in plaque‐induced gingivitis are accentuated by circulating levels of the above hormones via mechanisms such as partial immune suppression, increased fluid exudation, stimulation of bone resorption and stimulation of fibroblast synthetic activity. High counts of Bacteroides intermedius have been observed in users of oral contraceptives and also in the second trimester of pregnancy, in the absence of overt gingival inflammation. This is due to competition for binding between progesterone and naphthaquinone, which have a structural similarity; and the latter is an essential nutrient for the microbe. Hence high counts of Bacteroides intermedius may be a more sensitive indicator of an altered systemic hormonal condition than the usual clinical parameters. The main hormonal effect accentuates false pocketing, rather than initiating a change in attachment levels, except in cases of progressive periodontal disease associated with plaque induced inflammation and bone loss.
Color conversion of alveolar bone density changes in digital subtraction images
Authors: Brägger U. , Pasquali L.
Published: December 2005

Abstract This study evaluated the influence of image processing of digital subtraction images on inter‐ and intra‐examiner agreement relative to the detection of alveolar bone change on radiographs. 62 sites on digital subtraction images from standardized radiographs from patients requiring periodontal surgery were included in this study. The images were displayed as digital subtraction images, contrast enhanced subtraction images and as color‐converted digital subtraction images. The images were projected in random order, analyzed by 4 interpreters and 1 of 8 possible diagnostic decisions was noted for each one of 62 sites. 2 months after the first evaluation, the slides were re‐analyzed. 3 different computations (overall agreement, specific agreement and k‐value) were calculated. The results indicated that image processing of subtraction images using pseudocolor display of the density changes might improve the intra‐ and inter‐examiner agreement.
Neutrophil chemotactic behaviour in patients with early‐onset forms of periodontitis
Authors: Kinane D. F. , Cullen C. F. , Johnston F. A. , Evans C. W.
Published: December 2005

Abstract Despite some reports to the contrary, it is generally assumed that early‐onset forms of periodontal disease (including both juvenile and rapidly progressive periodontitis) are associated with a defect in neutrophil (PMN) chemotactic behaviour. Using the Boyden chamber technique and N‐formyl‐methionyl‐leucyl‐phenylalanine (FMLP) to assess locomotion by the leading front method, we have failed to show any evidence for such depressed PMN locomotion. Indeed, when PMN chemotaxis and chemokinesis are considered in response to a range of chemoattractant doses our results indicate significant enhancement of all but random locomotion. When taken together with other studies, our results suggest that PMNs from patients with early‐onset periodontitis may show abnormal locomotory behaviour which can either be enhanced or reduced in nature. The extent to which these results reflect in vitro methodology is uncertain and, furthermore, their in vivo significance is unclear.
Is early plaque growth rate constant with time?
Authors: Quirynen M. , van Steenberghe D.
Published: December 2005

Abstract Early plaque growth and plaque topography were studied in 15 young adults with a healthy periodontium during a 4‐day period of no oral hygiene. After perfect tooth‐cleaning, the recolonisation of the buccal surfaces of 48 teeth (front teeth and premolars) was recorded at the start and after 6, 12, 24, 30. 36, 48, 54, 60, 72, 84 and 96 h. At each visit, reproducible colour slides of the buccal tooth surfaces were taken after plaque disclosure. Plaque extension was calculated planimetrically as a % of the total surface area of the tooth. At the end of the experimental period, an average of 27.7% of the surface area was covered by plaque. The early plaque growth followed an exponential curve with a slight tendency for saturation at 96 h. During the night, the plaque growth rate decreased by up to 50%. Clear differences in plaque growth rate were observed between types of teeth, and the plaque growth pattern seemed to be closely correlated to irregularities of the tooth surface. The discontinuity in plaque growth and the influence from the tooth surface roughness have important implications for oral hygiene planning.
Clinical and microbiological effects of daily brushing with either NaF or SnF2 gels in subjects with fixed or removable dental prostheses
Authors: Tinanoff Norman , Manwell Mary A. , Zameck Ricki L. , Grasso Joseph E.
Published: December 2005

Abstract 61 adults, with fixed or removable dental protheses, completed a 6‐month double‐blind trial comparing the clinical and microbial effects of brushing twice daily with either 0.22% NaF or 0.4% SnF2. Those subjects brushing with SnF2 had less gingivitis and fewer bleeding sites for both “total teeth” and “abutment teeth”. Plaque scores between groups were only statistically different for the “abutment teeth”. The microbial parameters, salivary S. mutans and subgingival plaque total CPU, were significantly reduced in the SnF2 group. In both treatment groups, there was a reduction over the course of the study in the number of subjects with recoverable A. actinomycetemcomitans and black pigmented bacteroides. yet there was no difference between groups.
Black‐pigmented Bacteroides species and Actinobacillus actinomycetemcomitans in subgingival plaque of adult Kenyans
Authors: Dahlén Gunnar , Manji Firoze , Baelum Vibeke , Fejerskov Ole
Published: December 2005

Abstract A microbiological study was performed of the subgingival plaque on 2 sites in each of 20 adults originating from a rural area 40 km outside Nairobi, Kenya. The recovery rate of B. gingivalis was 70%, of B. intermedius 100% and of A. actinomycetemcomitans 40% of the subjects, and 50%, 90% and 28%, respectively, of the sites. The isolated strains exhibited similar biochemical characteristics and antibiotic susceptibility pattern as type strains of these species. The high recovery rate of these 3 bacterial species in adult Kenyans was a rather surprising finding, since pathological pocketing was found only sporadically. Furthermore, the results of 2 methodological approaches tested demonstrated that such microbiological studies can be carried out in countries with limited laboratory facilities.
Chemotherapeutic inhibition of supragingival dental plaque and gingivitis development
Authors: DePaola Louis G. , Overholser C. Daniel , Meiller Timothy F. , Minah Glenn E. , Niehaus Carol
Published: December 2005

Abstract A 6‐month double‐blind, controlled clinical study was conducted on 107 healthy adult subjects to determine the efficacy of a mouthrinse used as a supplement to regular oral hygiene measures on supragingival dental plaque and gingivitis. 115 healthy adult patients were recruited for the study. Following screening examinations for minimal entry levels of existing gingivitis and plaque in patients with a minimum of 20 sound natural teeth, extrinsic tooth stain, gingivitis and plaque index scores were recorded. Soft tissues were evaluated. All subjects then received a complete dental prophylaxis, removing plaque, calculus and extrinsic stain. Utilizing their normal oral hygiene, subjects began a regimen of rinsing with 20 ml of the randomly assigned rinse, twice daily for 30 s for 6 months. 7 days after prophylaxis, gingivitis was again scored (baseline 2). Soft tissue, gingivitis, plaque area and extrinsic stain were evaluated again at 3 and 6 months. Results demonstrated that after 6 months, listerine produced a 34% inhibition of both plaque and of gingivitis compared to a hydroalcohol control (p<0.001).
Osseous defect responses to hydroxylapatite grafting versus open flap debridement
Authors: Yukna Raymond A.
Published: December 2005

Abstract Data from a large number of defects (152) treated with hydroxylapatite (HA) grafts were compared to those from a large number of defects (111) treated by surgical debridement alone (DEBR). Comparison of initial and re‐entry surgery measurements showed that both the analysis of relative defect fill and the intrapatient comparisons demonstrated an advantage to the use of HA graft material, 58% of the HA‐grafted defects were judged to have a positive (≥50% defect fill) hard tissue response compared to 30% for DEBR. Minimal responses (failures) were 4 times as numerous with DEBR. Similarly, within each patient, HA grafting proved of benefit, particularly regarding hard tissue changes. The use of HA graft materials appears to be of clinical benefit in a majority of defects and a majority of patients.
Direct and immune‐cell‐mediated effects of Bacteroides gingivalis on bone metabolism in vitro
Authors: Bom‐van Noorloos A. A. , van Steenbergen T. J. M. , Burger E. H.
Published: December 2005

Abstract We investigated direct and immune‐cell‐mediated effects of Bacteroides gingivalis on bone metabolism in vitro. Fetal mouse long‐bone rudiments were cultured under aerobic conditions in the presence of (a) intact bacteria, (b) low molecular weight (MW < 1000) metabolic products of the bacteria, or (c) conditioned media of mouse spleen cells activated by whole bacteria. A suspension of intact bacteria, added directly to the bone culture, had no effect on bone resorption or bone formation. Low molecular weight (MW < 1000) excretion products of the bacteria inhibited bone resorption and transiently reduced mineralization of the diaphysis, while the growth in length of the bones was not affected. However, conditioned media of bacteria‐activated spleen cells strongly enhanced bone resorption and increased osteoclast numbers in the bone culture, while inhibiting mineral formation in the diaphysis. This led to a strongly negative mineral balance. These data do not support a direct effect of either bacteria or bacterial products on bone tissue as a likely explanation for bone loss in periodontal disease. Rather, they favour the concept that the loss of bone in this disease is an indirect effect of the host response, resulting from the contact of immune cells with the bacteria. This implies that bacterial invasion of the connective tissue of the gingiva may not be a prerequisite for alveolar bone loss.
Occupational health problems and adverse patient reactions in periodontics
Authors: Jacobsen N. , Hensten‐Pettersen A.
Published: December 2005

Abstract The purpose of the present survey was to assess the nature and extent of adverse reactions to materials and procedures among personnel in periodontal practice and their patients. A questionnaire was mailed to practicing members of the Swedish Society of Periodontitis. A total of 85, about 65%. responded together with 44 dental hygienists and 64 chairside assistants. 42% had experienced adverse reactions. The majority of complaints were related to dermatoses of the hands and fingers. The remainder were respiratory or eye reactions. A specifical problem characteristically involving the hygienists, was musculoskeletal stress reactions. Many of the dermatoses were of moderate severity, and were associated with seasonal, air–ventilation problems or were unexplained. The most severe reactions were reported by atopic persons. The reactions were attributed to hand washing procedures, the use of latex gloves and other disposable personal equipment such as face masks and caps. Reactions attributed to dental materials or local anesthetics, characteristic of other reports from general dental practice, were absent. The survey indicated that personnel in periodontal practice have problems similar to many other categories of health personnel. Patient reactions were encountered at a frequency of 1 every other year per periodontitis. The majority were intraoral reactions to chlorhexidine mouthrinses. Other patient reactions were associated with exposure to latex gloves, eugenol‐containing periodontal packs, methacrylates and nickel–containing instruments. 2 instances of anaphylacloid reactions to latex gloves were encountered.
The microbiota of early periodontitis lesions in adults
Authors: Tanner Anne , Bouldin Hope
Published: December 2005

Abstract The predominant cultivable microbiota of shallow progressive (active) periodontal lesions in 4 adults (29–40 years) was compared to that of shallow inactive sites. Periodontal attachment levels were monitored longitudinally, and sites showing 2–3 mm attachment loss in the previous 1–2 months were considered disease active. Inactive sites showed no change in attachment level. The microbiota of shallow sites was dominated by gram negative rod species including Wolinella recta. Bacteroides forsythus, and Fusobacterium nucleatum. W. recta was isolated in higher incidence and proportions from the active compared to inactive sites, and showed a positive relationship to bleeding on probing. Cluster analysis of species isolated from sites grouped sites from each individual together. This preliminary investigation suggested that a similar range of pathogens may be related to early periodontitis in adults as that previously reported for advanced diseased sites, and that different subjects may demonstrate different periodontal infections.
A longitudinal evaluation of Periodontal therapy using the CPITN index
Authors: Persson Rutger , Svendsen John , Daubert Karen
Published: December 2005

Abstract. A retrospective 3‐year longitudinal evaluation of periodontal therapy using the CPITN index was performed. Each sextant in 123 patients exhibiting moderate to advanced adult periodontitis was given a score that recorded the condition of the worst affected site in that sextant. Whereas very few sextants had an initial CPITN Code 0, the prevalence of sextants with an initial CPITN Code 4 was quite high. Posterior sextants with CPITN Code 4 were more likely treated with surgery than sextants with CPITN Code 3. Although surgery appeared to be more effective than non‐surgical therapy in reducing the CPITN Codes for posterior sextants at I year, there were no differences between the 2 forms of therapy at the 3‐year examination. Anterior sextants were treated with a non‐surgical approach regardless of CPITN Code at either initial examination or reevaluation. The outcome of therapy in this study using the CPITN index is comparable to other studies utilizing mean pocket depth and attachment level. Although the CPITN index does not prescribe specific therapeutic interventions, this index provides a useful tool to monitor patients in the treatment of periodontitis.
Clinical and microscopic findings in edentulous patients 3 years after incorporation of osseointegrated implant‐supported bridgework
Authors: Bower R. C. , Radny N. R. , Wall C. D. , Henry P. J.
Published: December 2005

Abstract. 15 mandibular fixed prostheses supported by osseointegrated titanium implants were examined 3 years after insertion. No implants had been lost after 3 years and all prostheses were present and continuously functional. The morphotypic analysis of the microbial plaque taken from titanium implants adjacent to clinically inflamed tissues was different from that described of the dental plaque associated with sites of gingival inflammation. Radiographs demonstrated early horizontal bone loss adjacent to osseointegrated fixtures and occasional continuing horizontal bone loss at some sites during the 1st and 2nd years after prosthesis installation. All fixtures remained integrated after 3 years of function supporting fixed prostheses. Minor differences between the results of this study and earlier studies may reflect differences in surgical technique.
Interaction between chlorhexidine digluconate and sodium lauryl sulfate in vivo
Authors: Barkvoll Pål , Rølla Gunnar , Svendsen Anne Kristin
Published: December 2005

Abstract. Chlorhexidine (CH) is cationic and it forms salts of low solubility with anions such as phosphate, sulfate and carboxyl. Toothpastes contain anionic detergents, one of the most widely used being sodium lauryl sulfate (SLS). The aim of the present study was to examine the possible interaction between CH and the anion SLS in vivo. The interference of SLS on the antiplaque potential of CH was investigated. The study was performed according to a single blind cross over design, and the effect of the interval between prerinsing with an aqueous solution of SLS and the subsequent rinsing with CH was examined. The anti‐plaque effect was examined by the use of the Silness and Löe plaque‐index. The results showed that even a 30‐min interval between SLS‐ and CH‐rinsing gave a significantly reduced antiplaque effect of CH, whereas the neutralizing effect of SLS disappeared after 2 h. It can thus be concluded that SLS is not compatible with CH. even when these compounds are introduced separately in the oral cavity. The time between toothbrushing and a CH rinse should at least be 30 min, if a reduction in the antimicrobial effect is to be avoided.
Evaluation of gingival bleeding following 4 types of periodontal therapy*
Authors: Kalkwarf Kenneth L. , Kaldahl Wayne B. , Patil Kashinath D. , Molvar Michael P.
Published: December 2005

Abstract. This study evaluated the effects of 4 types of periodontal therapy (coronal scaling (CS), root planing (RP), modified Widman surgery (MW), and flap with osseous resectional surgery (FO)) and subsequent maintenance care upon bleeding on probing (BOP). 75 individuals completed split mouth therapy and 2 years of maintenance followup. Data were obtained by 1 calibrated examiner prior to the initiation of therapy, following the hygienic phase and surgical phase of active therapy and yearly during maintenance care. All types of therapy reduced the prevalence of BOP. At the end of 2 years of maintenance therapy, regions >5 mm treated by CS demonstrated a significantly (p<0.05) greater prevalence of BOP sites than regions treated by the other modalities. Generally, sites associated with deeper probing depths exhibited a greater tendency to bleed and sites with associated plaque accumulation bled more frequently. RP resulted in a significantly (p<0.05) higher % of bleeding sites that stopped following active therapy than did CS. Throughout the study, BOP was extremely dynamic, with 15–88% of sites converting to a new status between any 2 examination periods. This dynamic nature may explain the inability of previous investigations to establish BOP as a reliable predictor of periodontal breakdown.
Detection of high‐risk groups and individuals for periodontal diseases: laboratory markers from analysis of saliva*
Authors: Wilton J. M. A. , Curtis M. A. , Gillett I. R. , Griffiths G. S. , Maiden M. F. J. , Sterne J. A. C. , Wilson D. T. , Johnson N. W.
Published: December 2005

AbstractThe use of saliva as a source of components that may identify subjects at risk of developing destructive periodontitis. or provide markers of disease potential or activity, has been reviewed. It was concluded that bacteria, their constituents or products are unlikely to be rewarding and that host‐derived salivary factors such as enzymes cannot identify risk, as deficiency states for these do not exist. Secretory IgA, plasma IgA and IgG isotype levels and specific antibodies may be associated with risk, but probably only if levels fall below those which are protective or a specific antibody response is absent. More work is needed to distinguish between monomeric and dimeric IgA antibodies and to identify IgG antibodies in longitudinal clinical studies. In general, although saliva may prove to be useful as a source of indicators of current disease activity or as a means of assessing responses to treatment, it is unlikely to provide evidence for the existence of risk factors.
An evaluation of 6 dentifrice formulations for supragingival anticalculus and antiplaque activity
Authors: Disney Judith A. , Graves Richard C. , Cancro Lewis , Payonk Gregory , Stewart Paul
Published: December 2005

Abstract A 4 week, double blind clinical trial was conducted to assess the antiplaque/anticalculus activity of test dentifrices containing varying levels of zinc citrate. Subjects were divided into 6 groups, 4 experimental, 1 positive control and a placebo group. All subjects only brushed at home using the placebo control during study weeks 1 and 3. Plaque and calculus were collected at the end of study weeks 2 and 4 on mylar strips worn on lower incisor teeth. Dentifrice efficacy was assessed by comparing group dry and ash weight decrements. While there were no significant differences between the test and control groups, there was a demonstrable trend toward greater inhibition with higher zinc citrate levels, expecially among subjects with high levels of plaque and calculus at baseline.
Determination of the facial/oral alveolar crest using RF‐echograms
Authors: Löst C. , Irion K.‐M. , Nüssie W.
Published: December 2005

Abstract This study is a part of a research project in which we have been investigating the use of the ultrasonic pulse echo technique as a means of determining in vivo the facial/oral alveolar crest precisely and routinely. Here, RF‐echograms are presented, showing the facial/oral periodontium of pigs. These echograms have been produced using a focussed 20 MHz transducer and a special design of an ultrasonic measuring and analysis system. In one series of measurements on macerated periodontia of pigs we found out that RF‐echograms characteristic of a particular level of the facial/oral pericrestal aspect can be achieved. Based upon these results, we succeeded in determining exactly the height of the facial/oral alveolar crest in a 2nd experimental group using the intact periodontium of pigs. In all experiments, we tried to image separately both the echo amplitudes of the facial/oral alveolar plate and of the tooth surface. In other words, the periodontal ligament space is imaged sonographically. In our experience, the imaging of the space is an important aspect for the correct interpretation of echograms. Possibilities and limits of this method are demonstrated and explained.
A combination of platelet‐derived and insulin‐like growth factors enhances periodontal regeneration
Authors: Lynch S. E. , Williams R. C. , Poison A. M. , Howell T. H. , Reddy M. S. , Zappa U. E. , Antoniades H. N.
Published: December 2005

Abstract The combination of platelet‐derived growth factor (PDGF) and insulin‐like growth factor one (IGF‐1) has previously been shown to enhance repair of soft tissue wounds. Here we report initial observations following application of PDGF and IGF‐1 to periodontitis‐affected teeth in beagle dogs, 1 μg of PDGF and IGF‐1 in an aqueous gel was applied to the root surfaces of test teeth following open flap debridement. Control sites received the gel alone. Block biopsies of the teeth and surrounding bone were taken 2 weeks after treatment. Histologic analyses of control specimens revealed a long junctional epithelial attachment, and no new bone or cementum formation. In contrast, growth factor treated sites exhibited significant amounts of new bone and cementum formation. A nearly continuous layer of osteoblasts lined the newly formed bone, and there was a dense cellular “front” at the coronal extent of the new bone. These preliminary results suggest that in vivo application of the combination of PDGF and IGF‐1 may enhance regeneration of the periodontal structures.
POST-INFLATION INCREASE OF THE COSMOLOGICAL TENSOR-TO-SCALAR PERTURBATION RATIO
Authors: BARTOLO N. , KOLB EDWARD W. , RIOTTO A.
Published: December 2005

We investigate the possibility that the amplitude of scalar density perturbations may be damped after inflation. This would imply that CMB anisotropies do not uniquely fix the amplitude of the perturbations generated during inflation and that the present tensor-to-scalar ratio might be larger than that produced in inflation, increasing the prospects of detection of primordial gravitational radiation. It turns out, however, that the damping of density perturbations is hard to achieve.
ON THE ORIGIN OF VERY HIGH ENERGY COSMIC RAYS
Authors: BLASI PASQUALE
Published: December 2005

We discuss the most recent developments in our understanding of the acceleration and propagation of cosmic rays up to the highest energies. In particular we specialize our discussion to three issues: (a) developments in the theory of particle acceleration at shock waves; (b) the transition from galactic to extragalactic cosmic rays; (c) implications of up-to-date observations for the origin of ultra high energy cosmic rays (UHECRs).
PEIERLS–YOCCOZ PROJECTION IN σ–ω MODELS
Authors: ALBERTO P. , AVANCINI S. S. , FIOLHAIS M.
Published: December 2005

We have used the Peierls–Yoccoz method to remove the center-of-mass energy of nuclei in the framework of mean-field sigma-omega models. The method is illustrated using small nuclei, such as the alpha particle and the nucleon itself. A quantized Hamiltonian of the model is required to implement the method. Nuclei are bound states of bare nucleons stabilized through the interactions with sigma and omega meson fields, which are described by coherent states. The quantized Hamiltonian contains a two-body quartic fermion interaction and it is shown that the exchange term has a large effect on the energy.
INTRUDER LEVELS AND VIBRATIONAL MODES IN THE SD-PAIR SHELL MODEL
Authors: LUO YAN-AN , PAN FENG , NING PING-ZHI , DRAAYER J. P.
Published: December 2005

The influence of the intruder level on vibrational modes in atomic nuclei is examined within the framework of the nucleon-pair shell model truncated to a SD-subspace. The vibrational character of the spectra is found to depend upon the size of the active model space and not on the parity of the populated levels.
A TEST FOR NON-COMMUTATIVE SPACE-TIME
Authors: SIDHARTH B. G.
Published: December 2005

We demonstrate in this note, that an underlying non-commutative geometry of space time leaves an experimental footprint, that is, the Landau levels.
FRACTAL ANALYSIS OF FLUCTUATION IN THE EMISSION SPECTRUM OF TARGET-ASSOCIATED FAST PARTICLES
Authors: BHATTACHARJEE B. , SENGUPTA S.
Published: December 2005

We study the intermittent and fractal behavior of the emission spectrum of target-associated fast particles from 84 Kr-AgBr interactions at 0.95 GeV/A. We used χ( cos θ) as the phase space variable. Normalized or scaled factorial moments studies for various orders of moment q = 2–5, confirmed the intermittent behavior. Gq moments have a fractal interpretation in their fluctuation in phase space. Our studies reveal the multi-fractal behavior of the emission spectrum.
RECOGNIZING DIFFERENT TYPES OF STOCHASTIC PROCESSES
Authors: KIM JONG U. , KISH LASZLO B.
Published: December 2005

We propose a new cross-correlation method that can recognize independent realizations of the same type of stochastic processes and can be used as a new kind of pattern recognition tool in biometrics, sensing, forensic, security and image processing applications. The method, which we call bispectrum correlation coefficient method, makes use of the cross-correlation of the bispectra. Three kinds of cross-correlation coefficients are introduced. To demonstrate the new method, six different random telegraph signals are tested, where four of them have the same power density spectrum. It is shown that the three coefficients can map the different stochastic processes to specific sub-volumes in a cube.
Impact of exercise training on insulin sensitivity, physical fitness, and muscle oxidative capacity in first-degree relatives of type 2 diabetic patients
Authors: Østergård Torben , Andersen Jesper L. , Nyholm Birgit , Lund Sten , Nair K.Sreekumaran , Saltin Bengt , Schmitz Ole
Published: December 2005

First-degree relatives of type 2 diabetic patients (offspring) are often characterized by insulin resistance and reduced physical fitness (V̇o2 max). We determined the response of healthy first-degree relatives to a standardized 10-wk exercise program compared with an age-, sex-, and body mass index-matched control group. Improvements in V̇o2 max(14.1 ± 11.3 and 16.1 ± 14.2%; both P < 0.001) and insulin sensitivity (0.6 ± 1.4 and 1.0 ± 2.1 mg·kg−1·min−1; both P < 0.05) were comparable in offspring and control subjects. However, V̇o2 maxand insulin sensitivity in offspring were not related at baseline as in the controls ( r = 0.009, P = 0.96 vs. r = 0.67, P = 0.002). Likewise, in offspring, exercise-induced changes in V̇o2 maxdid not correlate with changes in insulin sensitivity as opposed to controls ( r = 0.06, P = 0.76 vs. r = 0.57, P = 0.01). Skeletal muscle oxidative capacity tended to be lower in offspring at baseline but improved equally in both offspring and controls in response to exercise training (Δcitrate synthase enzyme activity 26 vs. 20%, and Δcyclooxygenase enzyme activity 25 vs. 23%. Skeletal muscle fiber morphology and capillary density were comparable between groups at baseline and did not change significantly with exercise training. In conclusion, this study shows that first-degree relatives of type 2 diabetic patients respond normally to endurance exercise in terms of changes in V̇o2 maxand insulin sensitivity. However, the lack of a correlation between the V̇o2 maxand insulin sensitivity in the first-degree relatives of type 2 diabetic patients indicates that skeletal muscle adaptations are dissociated from the improvement in V̇o2 max. This could indicate that, in first-degree relatives, improvement of insulin sensitivity is dissociated from muscle mitochondrial functions.
Cardiac metabolism in mice: tracer method developments and in vivo application revealing profound metabolic inflexibility in diabetes
Authors: Oakes Nicholas D. , Thalén Pia , Aasum Ellen , Edgley Amanda , Larsen Terje , Furler Stuart M. , Ljung Bengt , Severson David
Published: December 2005

Studies of cardiac fuel metabolism in mice have been almost exclusively conducted ex vivo. The major aim of this study was to assess in vivo plasma FFA and glucose utilization by the hearts of healthy control ( db/+) and diabetic ( db/db) mice, based on cardiac uptake of (R)-2-[9,10-3H]bromopalmitate ([3H]R-BrP) and 2-deoxy-d-[U-14C]glucose tracers. To obtain quantitative information about the evaluation of cardiac FFA utilization with [3H]R-BrP, simultaneous comparisons of [3H]R-BrP and [14C]palmitate ([14C]P) uptake were first made in isolated perfused working hearts from db/+ mice. It was found that [3H]R-BrP uptake was closely correlated with [14C]P oxidation ( r2= 0.94, P < 0.001). Then, methods for in vivo application of [3H]R-BrP and [14C]2-DG previously developed for application in the rat were specially adapted for use in the mouse. The method yields indexes of cardiac FFA utilization ( Rf*) and clearance ( Kf*), as well as glucose utilization ( Rg′). Finally, in the main part of the study, the ability of the heart to switch between FFA and glucose fuels (metabolic flexibility) was investigated by studying anesthetized, 8-h-fasted control and db/db mice in either the basal state or during glucose infusion. In control mice, glucose infusion raised plasma levels of glucose and insulin, raised Rg′ (+58%), and lowered plasma FFA level (−48%), Kf* (−45%), and Rf* (−70%). This apparent reciprocal regulation of glucose and FFA utilization by control hearts illustrates metabolic flexibility for substrate use. By contrast, in the db/db mice, glucose infusion raised glucose levels with no apparent influence on cardiac FFA or glucose utilization. In conclusion, tracer methodology for assessing in vivo tissue-specific plasma FFA and glucose utilization has been adapted for use in mice and reveals a profound loss of metabolic flexibility in the diabetic db/db heart, suggesting a fixed level of FFA oxidation in fasted and glucose-infused states.
Ascorbic acid-independent synthesis of collagen in mice
Authors: Parsons Kelly K. , Maeda Nobuyo , Yamauchi Mitsuo , Banes Albert J. , Koller Beverly H.
Published: December 2005

The mouse has become the most important model organism for the study of human physiology and disease. However, until the recent generation of mice lacking the enzyme gulanolactone oxidase (Gulo), the final enzyme in the ascorbic acid biosynthesis pathway, examination of the role of ascorbic acid in various biochemical processes using this model organism has not been possible. In the mouse, similar to most mammals but unlike humans who carry a mutant copy of this gene, Gulo produces ascorbic acid from glucose. We report here that, although ascorbic acid is essential for survival, its absence does not lead to measurable changes in proline hydroxylation. Vitamin C deficiency had no significant effect on the hydroxylation of proline and collagen production during tumor growth or in angiogenesis associated with tumor or mammary gland growth. This suggests that factors other than ascorbic acid can support proline hydroxylation and collagen synthesis in vivo. Furthermore, the failure of Gulo−/−mice to thrive on a vitamin C-deficient diet therefore suggests that ascorbic acid plays a critical role in survival other than the maintenance of the vasculature.
Effects of streptozotocin-induced diabetes and physical training on gene expression of extracellular matrix proteins in mouse skeletal muscle
Authors: Lehti T. Maarit , Silvennoinen Mika , Kivelä Riikka , Kainulainen Heikki , Komulainen Jyrki
Published: December 2005

Diabetes induces changes in the structure and function of the extracellular matrix (ECM) in many tissues. We investigated the effects of diabetes, physical training, and their combination on the gene expression of ECM proteins in skeletal muscle. Mice were divided to control (C), training (T), streptozotocin-induced diabetic (D), and diabetic training (DT) groups. Training groups (T, DT) performed 1, 3, or 5 wk of endurance training on a treadmill. Gene expression of calf muscles was analyzed using microarray and quantitative PCR. Training group samples were collected 24 h after the last training session. Diabetes affected the gene expression of several collagens (types I, III, IV, V, VI, and XV), some noncollagenous glycoproteins, and proteoglycans (e.g., elastin, thrombospondin-1, laminin-2, decorin). Reduced gene expression of collagens in diabetic skeletal muscle was partially attenuated as a result of physical training. In diabetes, mRNA expression of the basement membrane (BM) collagens decreased and that of noncollagenous glycoproteins increased. This may change the structure of the BM in a less collagenous direction and affect its properties.
Effect of medical castration on CD4+CD25+T cells, CD8+T cell IFN-γ expression, and NK cells: a physiological role for testosterone and/or its metabolites
Authors: Page Stephanie T. , Plymate Stephen R. , Bremner William J. , Matsumoto Alvin M. , Hess David L. , Lin Daniel W. , Amory John K. , Nelson Peter S. , Wu Jennifer D.
Published: December 2005

The higher prevalence of autoimmune disease among women compared with men suggests that steroids impact immune regulation. To investigate how sex steroids modulate cellular immune function, we conducted a randomized trial in 12 healthy men aged 35–55 yr treated for 28 days with placebo, a GnRH antagonist, acyline to induce medical castration, or acyline plus daily testosterone (T) gel to replace serum T, followed by a 28-day recovery period. Serum hormones were measured weekly and peripheral blood lymphocytes (PBLs) were collected biweekly for analyses of thymus-derived lymphocyte (T cell) subtypes and natural killer (NK) cells. Compared with the other groups and to baseline throughout the drug exposure period, men receiving acyline alone had significant reductions in serum T (near or below castrate levels), dihydrotestosterone, and estradiol ( P < 0.05). Medical castration significantly reduced the percentage of CD4+CD25+T cells ( P < 0.05), decreased mitogen-induced CD8+T cell IFN-γ expression, and increased the percentage of NK cells without affecting the ratio of CD4+to CD8+T cells and the expression of NK cell-activating receptor NKG2D or homing receptor CXCR1. No changes in immune composition were observed in subjects receiving placebo or acyline with replacement T. These data suggest that T and/or its metabolites may help maintain the physiological balance of autoimmunity and protective immunity by preserving the number of regulatory T cells and the activation of CD8+T cells. In addition, sex steroids suppress NK cell proliferation. This study supports a complex physiological role for T and/or its metabolites in immune regulation.
Effects of chronic Akt activation on glucose uptake in the heart
Authors: Matsui Takashi , Nagoshi Tomohisa , Hong Eun-Gyoung , Luptak Ivan , Hartil Kirsten , Li Ling , Gorovits Naira , Charron Maureen J. , Kim Jason K. , Tian Rong , Rosenzweig Anthony
Published: December 2005

Acute activation of the serine-threonine kinase Akt is cardioprotective and increases glucose uptake, at least in part, through enhanced expression of GLUT4 on the sarcolemma. The effects of chronic Akt activation on glucose uptake in the heart remain unclear. To address this issue, we examined the effects of chronic Akt activation on glucose uptake, glycogen storage, and relevant glucose transporters in the hearts of transgenic mice. We found that chronic cardiac activation of Akt led to a substantial increase in the rate of basal glucose uptake ( P < 0.05) but blunted the response to insulin (1.9 vs. 18.1-fold increase compared with baseline) using NMR in ex vivo perfused heart. Basal glucose uptake was also increased in Akt transgenic mice in vivo ( P < 0.005). These changes were associated with an increase on glycogen deposition, examined with histochemical staining, biochemical (>6-fold, P < 0.001) and in vivo radioactive (5-fold, P < 0.01) assays. Studies in chimeric hearts of female X-linked transgenic Akt mice suggested that increased glycogen deposition occurred as a cell autonomous effect of transgene expression. Interestingly, although sarcolemmal GLUT1 was not significantly altered, chronic Akt activation actually decreased plasma membrane GLUT4. Moreover, intracellular pools of GLUT1 were modestly reduced, whereas intracellular GLUT4 was substantially reduced. It seems likely that neither GLUT1 nor GLUT4 explains the increase in basal glucose uptake but that these reductions contribute to the loss of insulin responsiveness that we observed. These data demonstrate that chronic Akt activation increases basal glucose uptake and glycogen deposition while inhibiting the response to insulin.
Iron Imports. III. Transfer of iron from the mucosa into circulation
Authors: Wessling-Resnick Marianne
Published: December 2005

Transfer of iron from the mucosa is a critical step in dietary iron assimilation that is tightly regulated to ensure the appropriate amount of iron is absorbed to meet the body's demands. Too much iron is highly toxic, and failure to properly control intestinal iron export causes iron overload associated with hereditary forms of hemochromatosis. One form of genetic iron overload, ferroportin disease, originates due to defects in ferroportin, the membrane iron exporter. Ferroportin acts in conjunction with the intestinal ferroxidase hephaestin to mediate release of iron from the enterocyte. How iron is then acquired by transferrin and released into circulation remains an unknown step in this process.