bluuebunny/crossref_metadata_2025 huggingface dataset:
Minocycline inhibits apoptotic cell death via attenuation of TNF‐α expression following iNOS/NO induction by lipopolysaccharide in neuron/glia co‐cultures
Authors: Lee Sang M. , Yune Tae Y. , Kim Sun J. , Kim Young C. , Oh Young J. , Markelonis George J. , Oh Tae H.
Published: October 2004

We attempted to ascertain the neuroprotective effects and mechanisms of minocycline in inflammatory‐mediated neurotoxicity using primary neuron/glia co‐cultures treated with lipopolysaccharide (LPS). Neuronal cell death was induced by treatment with LPS for 48 h, and the cell damage was assessed using lactate dehydrogenase (LDH) assays and by counting microtubule‐associated protein‐2 (MAP‐2) positive cells. Through terminal transferase deoxyuridine triphosphate‐biotin nick end labeling (TUNEL)‐staining and by measuring caspase‐3 activity, we found that LPS‐induced neuronal cell death was mediated by apoptosis. We determined that pre‐treatment with minocycline significantly inhibited LPS‐induced neuronal cell death. In addition, LPS induced inducible nitric oxide synthase (iNOS) expression significantly, resulting in nitric oxide (NO) production within glial cells, but not in neurons. Both nitric oxide synthase (NOS) inhibitors (NG‐monomethyl‐l‐arginine monoacetate (l‐NMMA) and S‐methylisothiourea sulfate (SMT)) and minocycline inhibited iNOS expression and NO release, and increased neuronal survival in neuron/glia co‐cultures. Pre‐treatment with minocycline significantly inhibited the rapid and extensive production of tumor necrosis factor‐alpha (TNF‐α) mediated by LPS in glial cells. We also determined that the signaling cascade of LPS‐mediated iNOS induction and NO production was mediated by TNF‐α by using neutralizing antibodies to TNF‐α. Consequently, our results show that the neuroprotective effect of minocycline is associated with inhibition of iNOS induction and NO production in glial cells, which is mediated by the LPS‐induced production of TNF‐α.
Compound Democracy and the Control of Corruption: A Cross‐Country Investigation
Authors: Bohara Alok K. , Mitchell Neil J. , Mittendorff Carl F.
Published: October 2004

In this article we evaluate the influence of democracy on perceived levels of corruption. We argue that the control of corruption depends on the compensation and accountability of public officials, and on an open and competitive economy. We analyze the influence of democracy, controlling for the influence of other political and economic factors including federalism, economic development, and economic competition. The findings for the importance of economic factors are consistent. The finding in earlier research that federalism increases corruption is not robust. The findings for democracy are influenced importantly by the way that democracy is measured, but we do find that citizens’ repetitive participation in competitive elections increases the control of corruption. In doing so, we move beyond the composite indices of democracy in constructing an alternative compound measure of democracy, which we argue is likely to be useful in other research contexts
Competitive Pressures and the Emergence of Mothers’ Aid Programs in the United States
Authors: Allard Scott W.
Published: October 2004

Do states compete in providing (or not providing) welfare services? Do competitive pressures shape state welfare program adoption? Even though interstate competition is viewed by some to be a ubiquitous feature of the American federal system and welfare state, there is mixed evidence as to whether such pressures have influenced cash assistance policy in the United States. Although evidence exists of competitive pressures in contemporary welfare program decisions, such pressures have not been found in examinations of early state welfare programs. To reconcile this seeming contradiction, I examine the impact of neighboring state behavior on the emergence of state Mothers’ Aid cash assistance programs during the early part of the twentieth century. Linking theory of intergovernmental competition to program diffusion, I argue that competitive pressures may play a greater role as programs evolve past the circumstances of initial adoption to decisions about program maintenance. Contrary to previous research, I find that state decisions regarding Mothers’ Aid were responsive to similar decisions in neighboring states. Further, there is evidence that women's political organizations were important to Mothers’ Aid adoption but not to how states subsequently structured those programs.
People, Places, and Policy: A Politically Relevant Framework for Efforts to Reduce Concentrated Poverty
Authors: Spencer James H.
Published: October 2004

This article identifies the persistence of spatially concentrated poverty, reviews the literature on an implicit people‐place binary theory of antipoverty policy, proposes a more integrated heuristic for understanding policy, and discusses how the classification can be the basis for a more refined understanding of the evolution of antipoverty policy, how and when politics drive the antipoverty agenda and uses the heuristic to encourage evaluators to refocus research on the multiple aspects of poor peoples’ lives. In general, proponents of either people‐based or place‐based policies have dominated the urban poverty debate. This tension has led to a fragmented and piecemeal approach to spatially concentrated poverty that focuses on either people or places and does not best serve the poor. The new heuristic specifies both the policy targets and the policy mechanisms for major programs, examining the degree to which each focuses on people or places, and the degree to which each relies on supply and demand side assumptions. This reclassification suggests that the assumptions inherent in public policy can provide insight into how antipoverty policy makers and advocates might respond to political cycles and major sociopolitical events, as well as how they might more critically evaluate their efforts.
Signal‐Averaged P Wave Duration and the Dimensions of the Atria
Authors: Dixen Ulrik , Joens Christian , Rasmussen Bo V. , Parner Jan , Jensen Gorm B.
Published: October 2004

Background: Delay of atrial electrical conduction measured as prolonged signal‐averaged P wave duration (SAPWD) could be due to atrial enlargement. Here, we aimed to compare different atrial size parameters obtained from echocardiography with the SAPWD measured with a signal‐averaged electrocardiogram (SAECG).

Methods: In 74 patients scheduled for elective echocardiography, an SAECG was recorded directly after the echocardiogram. We measured the SAPWD and registered clinical characteristics. The correlation between the SAPWD and the left atrial diameter (LAD), left atrial volume (LAV), right atrial volume (RAV), and total atrial volume (TAV) was analyzed by linear regression analyses. The effect of concomitant risk factors on TAV and the SAPWD was examined.

Results: Linear regression analysis showed that the correlation between the SAPWD and the LAD was significant (R2= 0.11, P = 0.03). However, LAV (R2= 0.15, P = 0.009), RAV (R2= 0.27, P = 0.0003), and TAV (R2= 0.37, P < 0.0001) were more strongly correlated to the SAPWD. The TAV and the SAPWD were not significantly associated with coexisting risk factors.

Conclusions: The SAPWD is significantly correlated to the atrial size; most strongly to the TAV. The size of the right atrium, with the sinus node area, appears to affect the SAPWD.
QRS Subtraction and the ECG Analysis of Atrial Ectopics
Authors: Shah Dipen , Yamane Teichi , Choi Kee‐Joon , Haissaguerre Michel
Published: October 2004

The recognition of the ubiquitous role of short coupled ectopics in the initiation of paroxysmal atrial fibrillation has renewed interest in their localization with the ultimate aim of facilitating their neutralization by catheter ablation. The P‐waves resulting from such ectopics are partly or completely concealed by the QRST of the preceding beat and therefore their morphology has been underutilized for localization purposes. Subtraction has been the most commonly used technique for QRST suppression and though an averaged template offers a higher signal‐to‐noise ratio, the immediately preceding QRST provides the best match between template and target and allows simple, nearly real‐time, and accurate subtraction without distorting the underlying P‐wave. Algorithms derived from clinical tachycardias as well as pacemapping have permitted a rational analysis and accurate prediction (81%) of the correct pulmonary vein of origin. Other nonpulmonary sources may also be similarly localized, particularly with the help of a catalogue of pacemaps from various sites. Incessant arrhythmia and frequent aberrancy limit the effectiveness of QRST suppression by subtraction. Further improvements in the localizing resolution of the P‐wave may depend upon knowledge of the relationship between recording electrodes and the underlying atria.
Unusual Evolution of ST Elevation Acute Myocardial Infarction
Authors: Akel Rami , Saeed Mohammad , Ware David L. , Chamoun Antonio J. , Birnbaum Yochai
Published: October 2004

We report a case of acute ST‐segment elevation myocardial infarction with an unusual evolution of ST‐segment elevation. Several possible explanations of this progression are discussed with supportive evidence for each explaination. The clinical, electrocardiographic, and angiographic features of this case are also illustrated.
Evaluation of Left Atrial Appendage Functions in Patients with Thrombus and Spontaneous Echo Contrast in Left Atrial Appendage by Using Color Doppler Tissue Imaging
Authors: Topsakal Ramazan , Eryol Namık Kemal , Çiçek Yüksel , Sağlam Hayrettin , Seyfeli Ergün , Abaci Adnan , Oğuzhan Abdurrahman , Ergin Ali , Başar Emrullah
Published: October 2004

Objective: Thrombus and spontaneous echo contrast (SEC) develops in the left atrial appendage (LAA) when LAA function is disturbed. Decrease of left atrial appendage emptying velocity shows LAA dysfunction. The purpose of this study is to examine the incidence of SEC and/or thrombus in LAA in patients with acute myocardial infarction and to assess the LAA function using color Doppler tissue imaging (CDTI) of the patients with detected SEC and/or thrombus.

Method and Results: Eighty‐four patients with acute myocardial infarction were included in the study. Spontaneous echo contrast and/or thrombus were observed in 24 (29%) of the 84 patients who were categorized as group 1 (mean age 59 ± 12 years). Sixty patients (71%) without thrombus and/or SEC in LAA were categorized as group 2 (mean age 58 ± 8 years). Left atrial diameters and left ventricular ejection fraction were measured by using transthoracic echocardiography. Left atrial appendage emptying and LAA filling velocity were measured by transesophageal Doppler echocardiography. Systolic appendage tissue velocities (SaV cm/s) were measured at the basal, mid, and tip of medial wall of LAA by transesophageal CDTI. Group 1 had significantly decreased LAA emptying velocities, mid SaVs, and left ventricular ejection fractions compared to group 2 (37 ± 9 cm/s vs 55 ± 22 cm/s, 3.1 ± 1.6 cm/s vs 3.7 ± 1.2 cm/s, and 47 ± 13% vs 58 ± 10%, respectively, P = 0.002, P = 0.04, P = 0.03). Group 1 had significantly increased left atrial diameters compared to group 2 (40 ± 5 mm vs 36 ± 6 mm P = 0.001). Left atrial appendage‐filling velocities, basal SaVs and tip SaVs in group 1 were lower than those in group 2 but not significantly.

Conclusions: Mid‐SaV of LAA medial wall and LAA emptying velocity decrease in patients with thrombus and/or SEC were an indication of functional disorder of LAA. Color Doppler tissue imaging appears to be a clinically applicable and reliable imaging technique that allows quantitative assessment of regional LAA systolic function.
Why a Sawtooth? Inferences on the Generation of the Flutter Wave during Typical Atrial Flutter Drawn from Radiofrequency Ablation
Authors: Bernstein Neil E. , Sandler David A. , Goh Mark , Feigenblum David Y. , Holmes Douglas S. , Chinitz Larry A.
Published: October 2004

Background: Typical atrial flutter (AFL) is a macroreentrant arrhythmia characterized by a counterclockwise circuit that passes through the cavotricuspid isthmus with passive depolarization of the left atrium. These electrical events are thought to be responsible for the classic “sawtooth” wave of atrial flutter seen on the surface electrocardiogram characterized by a gradual downward deflection followed by a sharp negative deflection. It has been suggested that the negative flutter wave is a result of passive depolarization of the left atrium. We hypothesized that interruption of the circuit within the isthmus would prevent the reentrant wave from depolarizing the left atrium thus eliminating the component of the electrocardiogram reflecting left atrial depolarization.

Methods: We examined 100 cases of atrial flutter with the typical “sawtooth” pattern referred for radiofrequency ablation. Ninety‐seven of the 100 were successfully ablated. All cases were reviewed for termination of atrial flutter with the last intracardiac electrogram just lateral to the site of linear ablation and surface flutter wave at the moment of termination not obscured by the QRS segment or the T‐wave. Seventeen of the 97 met these criteria.

Results: Seventeen of the 17 cases demonstrated a gradual negative deflection as the last discernible wave of atrial activity followed by an isoelectric period and resumption of normal sinus rhythm. The last generated wave lacked the sharp negative downstroke.

Conclusion: These results suggest that the sharp negative deflection of flutter waves likely correlates with the wavefront's penetration of the interatrial septum and passive depolarization of the left atrium.
Left Bundle Branch Block in Type 2 Diabetes Mellitus: A Sign of Advanced Cardiovascular Involvement
Authors: Guzman Eliscer , Singh Narpinder , Khan Ijaz A. , Niarchos Andreas P. , Verghese Cherian , Saponieri Cesare , Singh Harinder K. , Gowda Ramesh M. , Vasavada Balendu C. , Cohen Ronny A.
Published: October 2004

Objective: To evaluate left bundle branch block (LBBB) as an indicator of advanced cardiovascular involvement in diabetic (DM) patients by examining left ventricular systolic function and proteinurea.

Methods: Data of 26 diabetic patients with left bundle branch block (DM with LBBB) were compared with data of 31 diabetic patients without left bundle branch block (DM without LBBB) and 18 nondiabetic patients with left bundle branch block (non‐DM with LBBB). The inclusion criteria were age >45 years, and diabetes mellitus type 2 of >5 years.

Results: Mean ages of patients in DM with LBBB, DM without LBBB, and non‐DM with LBBB groups were 67 ± 8, 68 ± 10, and 65 ± 10 years, respectively (P = NS). Females were 65%, 61%, and 61%, respectively (P = NS). Left ventricular ejection fraction in DM with LBBB was significantly lower than in DM without LBBB and non‐DM with LBBB (30 ± 10% vs 49 ± 12% and 47 ± 8%, P < 0.01). Left ventricular end‐diastolic volume was significantly higher in DM with LBBB than in DM without LBBB and non‐DM with LBBB (188.6 ± 16.4 mL vs 147.5 ± 22.3 mL and 165.3 ± 15.2 mL, P < 0.03). Similarly, left ventricular end‐systolic volume was significantly higher in DM with LBBB than in DM without LBBB and non‐DM with LBBB (135.4 ± 14.7 mL vs 83.7 ± 9.5 mL and 96.6 ± 18.4 mL, P < 0.02). No statistically significant difference was seen in left atrial size. Proteinurea in DM with LBBB (79.4 ± 18.9 mg/dL) was significantly higher than in DM without LBBB (35.6 ± 8.5 mg/dL, P < 0.05) and non‐DM with LBBB (12 ± 3.5 mg/dL, P < 0.05); however, there was no significant difference in Hb A1c levels in DM with LBBB and DM without LBBB (9.01% vs 7.81%, P = NS).

Conclusions: Left bundle branch block in diabetic patients indicates advanced cardiovascular involvement manifesting with more severe left ventricular systolic dysfunction and proteinurea compared to both diabetic patients without left bundle branch block and nondiabetic patients with left bundle branch block.
Estrogen and Progestin Use and the QT Interval in Postmenopausal Women
Authors: Kadish Alan H. , Greenland Philip , Limacher Marian C. , Frishman William H. , Daugherty Sandra A. , Schwartz Janice B.
Published: October 2004

Objective: To determine whether menopausal hormone therapy alters the QT interval in primarily healthy postmenopausal women.

Background: Despite well‐known gender differences in myocardial repolarization that include a longer heart‐rate‐corrected QT interval (QTC) in women compared to men, the effects of menopausal hormone therapy on myocardial repolarization in women have not been well characterized.

Methods: We studied 34,378 postmenopausal women participating in the dietary intervention component of the Women's Health Initiative. Cross‐sectional associations were examined to assess possible effects of estrogen + progesterone on myocardial repolarization. Women who reported that they were never treated with menopausal hormone therapy (n = 12,451) were compared to women with a past use of menopausal hormone therapy (n = 3891), currently taking unopposed estrogen therapy (n = 9987), or combined current estrogen and progesterone therapy (n = 8049).

Results: Using analysis of covariance, the mean (±SEM) QTC interval was 423.1 ± 0.2 milliseconds (ms) in those never treated with menopausal hormone therapy, 423.9 ± 0.3 ms in past menopausal hormone therapy users, 425.6 ± 0.2 ms in those currently on estrogen alone, and 424.0 ± 0.2 ms in women currently on combined estrogen–progesterone therapy. Differences in mean QTC between those on estrogen alone and the other three groups were statistically significant. Comparisons of JT intervals, QT intervals, and linear corrected QT intervals among the groups yielded similar results.

Conclusion: These results suggest that unopposed estrogen in menopausal women mildly prolongs myocardial repolarization, and the effect is reversed by progesterone. Whether these findings have clinical significance requires further study.
New Criteria Based on ST Changes in 12‐Lead Surface ECG to Detect Proximal versus Distal Right Coronary Artery Occlusion in a Case of Acute Inferoposterior Myocardial Infarction
Authors: Fiol Miquel , Carrillo Andrés , Cygankiewicz Iwona , Ayestarán José , Caldés Onofre , Peral Vicente , Bethencourt Armando , Zareba Wojciech , De Luna Antoni Bayés
Published: October 2004

Background: The outcome of patients with inferoposterior myocardial infarction (MI) due to occlusion of right coronary artery (RCA) depends mainly on the location of occlusion (distal vs. proximal). The aim of this study was to evaluate the value of new ECG criteria: the sum of ST depression in I and VL leads and ST changes in V1 lead to predict the location of RCA occlusion in the case of an inferoposterior MI.

Methods: The ECG and angiographical findings of 50 patients with acute inferoposterior MI due to RCA occlusion were analyzed. The value of new criteria was studied alone and in combination to predict proximal versus distal RCA occlusion and compared with previously described criterion based only on ST changes in VL.

Results: Isoelectric or elevated ST in V1 allowed predicting proximal RCA occlusion with 70% sensitivity and 87% specificity with high positive and negative predictive value (87% and 71%, respectively). The new criterion of the sum of ST depression in I and VL ≥ 5.5 mm compared to the criterion based only on ST depression in VL was also more specific (91% vs. 72%) for proximal RCA occlusion with better positive and negative predictive values.

Conclusions: The new criterion based on the ST changes in V1 lead is highly accurate in detecting the location of occlusion in the RCA compared to the criteria based only on ST changes in lateral leads. The use of this criterion might increase the accuracy of ECG‐based identification of myocardial involvement in acute inferoposterior MI.
Long‐term vertical changes of the anterior maxillary teeth adjacent to single implants in young and mature adults
Authors: Bernard J. P. , Schatz J. P. , Christou P. , Belser U. , Kiliaridis S.
Published: October 2004

Aim: To evaluate the effects of the tooth eruption process on the position of teeth adjacent to implant‐borne restorations in adult patients compared to patients in their late adolescence.

Subject and Methods: The sample included 28 patients divided into two groups. A “young adult” group consisting of 14 patients, aged from 15.5 to 21 years, and a “mature adult” group consisting of 14 patients, aged from 40 to 55 years. All patients presented missing anterior teeth, requiring insertion of 40 implant fixtures (16 central incisors, 12 lateral incisors, 12 canines). The implants were of the Straumann Dental Implant System, clinically and radiologically re‐evaluated 1 year or more after the surgical procedure (mean interval=4.2 years). Assessment of the eruption of the adjacent teeth was performed using the implant as a stable point of reference: measurements of the different reference points were compared after implant placement and at follow‐up examination.

Results: In the “young adult” group, all patients showed infra‐occlusion of the implant‐supported crowns: the vertical step measured on radiographs varied between 0.1 and 1.65 mm. In the “mature adult” group, all patients showed a vertical difference between the teeth adjacent to the implant‐supported crown and the implant: the measured step ranged from 0.12 to 1.86 mm. No difference was found in the amount of vertical eruption between male and female patients, nor according to localization of the implant.

Conclusion: Mature adults can exhibit major vertical steps after anterior restorations with osseointegrated fixtures to the same extent as adolescents or “young adult” individuals with residuous growth potential.
Long‐term stability of periodontal conditions achieved following guided tissue regeneration with bioresorbable membranes: case series results after 6–7 years
Authors: Stavropoulos Andreas , Karring Thorkild
Published: October 2004

Objectives: To evaluate the results of guided tissue regeneration (GTR) treatment of intrabony defects with bioresorbable membranes after 6–7 years, and to disclose factors that may influence the long‐term outcome of the treatment.

Methods: Twenty‐five defects in 19 patients were treated by means of polylactic acid/citric acid ester copolymer bioresorbable membranes. At baseline and after 1 and 6–7 years, the following parameters were recorded: (1) probing pocket depth (PPD), (2) gingival recession (REC), (3) probing attachment level (PAL)=PPD+REC, (4) presence/absence of plaque (PI), (5) presence/absence of bleeding on probing (BOP). Smoking habits and frequency of dental‐control visits were also recorded. Significance of differences between categorical variables was evaluated with McNemar's test, and between numerical variables with the t‐test for paired observations. Generalized linear models were constructed to evaluate the influence of various factors on PAL gain and PPD changes from 1 to 6–7 years. Association of smoking, frequency of dental controls, oral hygiene, and BOP with sites losing 2 mm in PAL was evaluated with Fisher's exact test.

Results: At baseline, a mean PPD of 8.7±1.1 mm and a mean PAL of 9.8±1.5 mm was recorded. Statistically significant clinical improvements were observed at 1 and 6–7 years after GTR treatment. An average residual PPD of 3.8±1.1 mm and a mean PAL gain of 3.8±1.4 mm were observed after 1 year. After 6–7 years the corresponding values were 4.7±1.3 and 3.6±1.4 mm, respectively. There were no statistically significant differences between the 1‐ and the 6–7‐year values. At the 6–7‐year control, only 16% of the sites had lost 2 mm (maximum 3 mm), of the PAL gain obtained 1 year after GTR treatment. None of the sites had lost all of the attachment gained 1 year after treatment. Smoking, frequency of dental controls, oral hygiene, and BOP did not seem to influence the change of PPD and PAL gain, or the stability of PAL gain (i.e. losing PAL or not) from 1 to 6–7 years from treatment.

Conclusion: Clinical improvements achieved by GTR treatment of intrabony defects by means of bioresorbable membranes can be maintained on a long‐term basis.
Periodontal attachment loss attributable to cigarette smoking in an urban Brazilian population
Authors: Susin Cristiano , Oppermann Rui V. , Haugejorden Ola , Albandar Jasim M.
Published: October 2004

Aims: The present study estimated the percentages of cases with severe periodontal attachment loss (PAL) attributable to cigarette smoking in a representative adult urban population in southern Brazil.

Methods: A representative sample comprising 853 dentate individuals (age: 30–103 years) was selected by a multistage, probability sampling method. A full‐mouth clinical examination of six sites per tooth was performed and an interview using a structured written questionnaire was undertaken. Cases were defined as individuals with 30% teeth with PAL 5 mm. A multivariate logistic regression analysis for complex surveys was performed, and adjusted for age, gender, race, socioeconomic status and dental calculus.

Results: The prevalence of cases in this population was 49.7%, or 739,000 subjects. Overall, 50.9% of this adult population, or approximately 757,000 subjects have had a lifetime exposure to cigarette smoking. Multivariate analysis showed that heavy and moderate smokers had a significantly higher risk for PAL 5 mm than non‐smokers (odds ratio=3.6, 2.0, respectively) after adjusting for the above covariates. We estimated that the number of moderate and heavy smokers with 30% teeth with PAL 5 mm might be reduced by approximately 28% and 48%, respectively, had they not smoked cigarettes. We project that a smoking cessation program could result in a reduction in the number of cases by up to 12% in this population, or approximately 90,000 potential cases.

Conclusion: Cigarette smoking was strongly associated with severe attachment loss in this population. A significant percentage of cases may have been prevented if smoking cessation interventions had been implemented. The results support the implementation of population‐based smoking cessation programs to reduce the prevalence of severe attachment loss in populations with high level of smoking exposure.
Prognostic factors for alveolar regeneration: bone formation at teeth and titanium implants
Authors: Polimeni Giuseppe , Koo Ki‐Tae , Qahash Mohammed , Xiropaidis Andreas V. , Albandar Jasim M. , Wikesjö Ulf M. E.
Published: October 2004

Objectives: There is a limited understanding of the effect of defect characteristics on alveolar bone healing. The objectives of this study were to assess the effect of alveolar bone width and space provision on bone regeneration at teeth and titanium implants, and to test the hypothesis that the regenerative potentials at teeth and implants are not significantly different.

Methods: Critical size, 5–6‐mm, supra‐alveolar, periodontal defects were surgically created in 10 young adult dogs. Similarly, critical size, 5‐mm, supra‐alveolar, peri‐implant defects were created in four dogs. A space‐providing expanded polytetrafluoroethylene device was implanted for guided tissue regeneration/guided bone regeneration. The animals were euthanized at 8 weeks postsurgery. Histometric analysis assessed alveolar bone regeneration (height) relative to space provision by the device and the width of the alveolar crest at the base of the defect. Statistical analysis used the linear mixed models.

Results: A significant correlation was found between bone width and wound area (r=0.55892, p<0.0001). Generally, bone width and wound area had statistically significant effects on the extent of bone regeneration (p<0.0005 and p<0.0001, respectively). Bone regeneration was linearly correlated with the bone width at periodontal (p<0.001) and implant (p=0.04) sites, and with the wound area at periodontal (p<0.0001) and implant (p=0.03) sites. The relationships of bone regeneration with these two variables were not significantly different between teeth and implants (bone width: p=0.83; wound area: p=0.09). When adjusted for wound area, bone regeneration was significantly greater at periodontal than at implant sites (p=0.047).

Conclusions: The horizontal dimension of the alveolar bone influences space provision. Space provision and horizontal dimension of the alveolar bone appear to be important determinants of bone regeneration at teeth and implants. The extent of alveolar bone formation at implant sites is limited compared with that at periodontal sites.
Amine fluoride/stannous fluoride and incidence of root caries in periodontal maintenance patients
Authors: Paraskevas S. , Danser M. M. , Timmerman M. F. , Van Der Velden U. , Van Der Weijden G. A.
Published: October 2004

Aim: The purpose of the present study was to evaluate in a group of periodontal maintenance patients, the effect of using a dentifrice and mouthrinse containing amine fluoride (AmF) and stannous fluoride (SnF2) as compared with a dentifrice and mouthrinse both containing sodium fluoride (NaF) with regard to their root caries experience.

Material: In total, 80 patients who had been treated for moderate‐to‐severe periodontitis agreed to participate in this study. Subjects received supportive periodontal therapy at regular intervals of 3–4 months for at least a period of 1 year. The patients were randomly divided into two groups: (1) the test group used an AmF/SnF2 dentifrice and mouthrinse and (2) the control group used an NaF‐containing dentifrice and mouthrinse. Root caries was recorded at four sites per tooth at baseline and 24 months.

Results: An increase in number of the exposed root surfaces was noted for both groups during the experimental period (p<0.05). The mean number of active caries lesions at baseline was 2.1 and 1.8 for the test group and control group, respectively. At 24 months, the corresponding values were 1.8 for the test and 2.2 for the control group. An increase of the mean number of restored surfaces was noted for the AmF/SnF2 group (from 7.3 to 13.4) and the control group (from 7.9 to 14.7) during the course of the study. This increase was found to be statistically significant for both groups in comparison with the baseline values (p0.01). No statistically significant differences were noted between groups. Further analysis of the restored surfaces revealed that the major increase in number of the restorations was associated with restorations involving three to four root surfaces in the same tooth. Molars and premolars were the teeth receiving most new restorations.

Conclusion: The present study did not detect a difference in terms of root caries development between the two groups. Root caries development is a common finding associated with surfaces developing recession in patients once treated for periodontal problems.
Myeloid‐related protein (MRP)8/14 (calprotectin) and its subunits MRP8 and MRP14 in plaque‐induced early gingival inflammation
Authors: Que May Lan , Andersen Elene , Mombelli Andrea
Published: October 2004

Background: The inflammatory myeloid‐related protein, MRP8/14, also called calprotectin, and its subunits MRP8 and MRP14 have been detected and identified recently in gingival crevicular fluid (GCF). It has been suggested that the type and phase of inflammation can be discriminated on the basis of differences in the expression of calprotectin and its subunits, released during activation and/or death of granulocytes and monocytes. The purpose of this study was to quantify calprotectin and its subunits (MRPs) simultaneously in the GCF during the initial phase of experimentally induced gingivitis, and to examine their inter‐ and intra‐individual variations.

Material and Methods: Fifteen healthy non‐smoking subjects, aged 18–30, were involved in this study. An initial hygiene phase (days −11 to 0) was followed by 10 days of undisturbed plaque accumulation. At days −11, −3, 0, 10, 11, clinical parameters were recorded and GCF samples collected with Durapore strips from 12 sites in each subject. Quantitative analyses of total proteins, MRP8/14, MRP14 and MRP8 were performed by ELISA procedures.

Results: During the experimental phase with no oral hygiene (days 0–10), the clinical parameters Plaque Index, Gingival Index (GI) and bleeding on probing increased as expected, confirming that plaque accumulation leads to gingival inflammation. Levels of the MRPs were individually variable. They increased with plaque accumulation in one‐half of the subjects, and decreased in the other subjects. The levels of MRP8/14 and MRP14 at subject recruitment (day −11) could predict a significant part of the GI at day 10. Only minute amounts of the subunits MRP8 and MRP14 were detected in comparison with the complex MRP8/14 throughout the experiment. Considerable variations were noted among sites within subjects.

Conclusion: The expression of calprotectin in the early phase of experimental gingivitis is variable between subjects, and two groups of subjects can be differentiated according to their response patterns. Clinical parameters at the very first visit (day –11) seemed to be different in the two response groups. The results of the present investigation indicate that the inflammatory response to plaque accumulation depends on the initial status of the subjects, which may not be leveled out by the introduction of perfect oral hygiene. Whether these patterns reflect a different susceptibility to periodontal diseases remains to be determined.
The effect of periodontal treatment on the salivary bacterial load and early plaque formation
Authors: Dahan M. , Timmerman M. F. , Van Winkelhoff A. J. , Van der Velden U.
Published: October 2004

Aim: The purpose of the present study was to investigate in periodontitis patients the relationship between the number of bacteria in the saliva and the amount of de novo plaque formation before and after treatment.

Methods: At baseline, before any treatment was provided, patients rinsed with 10 ml sterile saline. After professional tooth cleaning the patients were instructed to abolish all tooth cleaning procedures for the subsequent 24 h. After this period, the rinsing procedure was repeated and the amount of de novo plaque was assessed. Three months after the initial periodontal therapy was completed the experiment was repeated. The microbiological evaluation of the rinsing samples was carried out by means of phase contrast microscopy and anaerobic culturing.

Results: After treatment the amount of de novo plaque was less compared to before treatment, 0.40 and 0.65 respectively. Both before and after treatment more de novo plaque was present at sites with inflammation than at healthy sites. In order to evaluate the contribution of the numbers of salivary bacteria to the amount of de novo plaque formation an analysis was carried out for healthy sites. This analysis included only healthy sites as determined before treatment and the same sites after treatment. The results showed a significant reduction in the de novo plaque formation after treatment (0.49 before and 0.22 after treatment). Phase contrast microscopic evaluation showed that the number of bacteria in the rinsing samples after treatment was less than before treatment. After treatment also a reduction was found in the prevalence of Prevotella intermedia, Tannerella forsythensis and Peptostreptococcus micros in the rinsing samples.

Conclusion: The present study confirms the observation in the literature that the periodontal condition is of major importance in the rate of de novo plaque formation. In addition, the results suggest that the number of bacteria in the saliva may play a role.
Subgingival microbiota of chronic periodontitis subjects from different geographic locations
Authors: Haffajee A. D. , Bogren A. , Hasturk H. , Feres M. , Lopez N. J. , Socransky S. S.
Published: October 2004

Background: Most clinical studies assume that the subgingival microbiota is similar from one geographic location to another. The purpose of the present investigation was to examine the composition of the subgingival microbiota in chronic periodontitis subjects from four countries.

Method: Subjects with chronic periodontitis (N, Sweden=101; USA=115; Brazil=58; Chile=26) were recruited. Subjects were measured at baseline for plaque, gingivitis, bleeding on probing (BOP), suppuration, pocket depth (PD) and attachment level (AL) at six sites per tooth. Subgingival plaque samples taken from the mesial aspect of each tooth at baseline were individually analyzed for their content of 40 bacterial species using checkerboard DNA–DNA hybridization (total samples=6036). % DNA probe counts comprised by each species was determined for each site and averaged across sites in each subject. Significance of differences in proportions of each species among countries was determined using ancova adjusting for age, mean pocket depth, gender and smoking status. p‐Values were adjusted for multiple comparisons.

Results: On average, all species were detected in samples from subjects in the four countries. Thirteen species differed significantly in adjusted mean proportions among countries even after adjusting for multiple comparisons. Porphyromonas gingivalis, one species that differed in proportions among countries, comprised adjusted means of 7.5, 11.9, 1.6 and 6.6% of the microbiota in subjects from Brazil, Chile, Sweden and USA (p<0.001), while mean proportions of Treponema denticola were 6.7, 4.2, 0.8 and 2.3, respectively (p<0.001). In contrast, a key periodontal pathogen, Tannerella forsythensis, exhibited mean proportions ranging from 6.2–8.5% and did not differ significantly among countries. Besides these species, prominent species in Brazil were Actinomyces naeslundii genospecies 1 and 2 (8.4%, 7.2%) and Prevotella intermedia (6.5%); in Chile, Prevotella melaninogenica (6.4%) and Neisseria mucosa (5.3%); in Sweden A. naeslundii genospecies 2 (8.4%), Capnocytophaga gingivalis (7.1%) and Peptostreptococcus micros (5.0%); in USA A. naeslundii genospecies 2 (7.5%), P. intermedia (6.8%) and C. gingivalis (6.1%).

Conclusions: The microbial profiles of subgingival plaque samples from chronic periodontitis subjects in four countries showed surprisingly marked differences. These differences persisted after adjusting for age, mean pocket depth, gender and smoking status.
Longitudinal stability of serum immunoglobulin G responses to periodontal bacteria
Authors: Papapanou P. N. , Neiderud A. M. , Disick E. , Lalla E. , Miller G. C. , Dahlén G.
Published: October 2004

Background: The value of seroepidemiology in the study of periodontal infections has not been adequately explored. This study examined serum immunoglobulin (IgG) responses to periodontal bacteria in patients with periodontitis and periodontitis‐free individuals over a 30‐month period.

Methods: Eighty‐nine patients with chronic periodontitis and 42 control subjects with no deep periodontal pockets and no or minimal attachment loss (30–72 years old, 43% men) were included. Patients were examined at baseline, after completed periodontal therapy 4 months post‐baseline, and at 30 months, and controls, at baseline and 30 months. IgG antibodies to 19 periodontal species were determined by checkerboard immunoblotting.

Results: On average, patients displayed at baseline up to 800‐fold higher titers than controls to all but three species. Over the 30‐month period, titers remained stable at low levels in controls. In patients, periodontal conditions improved from a baseline mean probing depth of 3.6 mm, bleeding on probing of 62% and an average of 21.5 pockets of=6 mm/person, to 2.5 mm mean pocket depth, 30% bleeding on probing, and 1.2 deep pockets, at 30 months. Over time, antibody titers showed a modest decline in patients, but remained significantly elevated at 30 months in comparison with controls. Antibody‐level changes over time were not significantly different between subjects that did and did not receive adjunctive systemic antibiotics.

Conclusions: Conspicuous differences in IgG titers to periodontal bacteria exist between periodontitis patients and periodontally healthy controls. Despite successful periodontal therapy, titers remained elevated over a 30‐month period, suggesting that serology may mark the history of past periodontal infection.
The CD14 −159C‐to‐T promoter polymorphism in periodontal disease
Authors: Folwaczny Matthias , Glas Jürgen , Török Helga‐Paula , Fricke Kathinka , Folwaczny Christian
Published: October 2004

Background: A single‐nucleotide promoter polymorphism in the CD14 gene was associated with various inflammatory conditions. The present study sought to determine the frequency of the CD14 −159C‐to‐T polymorphism among subjects with periodontitis and healthy control individuals.

Methods: A total of 70 patients with periodontal disease and 75 healthy controls were genotyped for the CD14 −159C‐to‐T polymorphism. Genotyping was performed by polymerase chain reaction and restriction fragment length polymorphism analysis. The allele frequencies and distribution of genotypes within both study groups were compared using Fisher's exact test at a level of significance of 5% (p<0.05).

Results: Overall, the frequency for the CD14 −159T allele in patients with periodontitis was 39.3% (55/140) and 48.0% (72/150) for the controls (p=0.135). The CD14 −159C allele was significantly more prevalent (p=0.013) among females with periodontitis (33.3%; 24/72) as compared with healthy control subjects (55.6%; 30/54). In contrast, the distribution of the CD14 −159C‐to‐T polymorphism showed no significant difference among males with and without periodontitis (p=0.816).

Conclusion: Herein, the C −159T promoter polymorphism of the CD14 gene was associated in female but not in male patients with periodontal disease.
Significant influence of scaler tip design on root substance loss resulting from ultrasonic scaling: a laserprofilometric in vitro study
Authors: Jepsen Søren , Ayna Mustafa , Hedderich Jürgen , Eberhard Jörg
Published: October 2004

Objectives: Ultrasonic scalers have become increasingly popular for subgingival debridement. The aim of the present study was to investigate the influence of different working tip designs (narrow versus wide) on root substance loss caused by either magnetostrictive or piezoelectric ultrasonic devices.

Methods: In this in vitro study, a magnetostrictive ultrasonic system with either Slimline or TFI‐10 inserts and a piezoelectric ultrasonic system with either Perioprobe or Type‐A inserts were compared at different application forces. Loss of root dentin was determined by defect width, defect depth and defect volume resulting from standardized instrumentation using laser profilometry.

Results: There were consistent and statistically significant differences between all groups. The mean observed dentin alterations for the magnetostrictive ultrasonic device operating a Slimline insert at a lateral force of 0.3 N were 254.4 μm, 6.3 μm and 22.5 μm3 and for the TFI‐10 tip 759.0 μm, 23.5 μm and 160.2 μm3 for the parameters defect width, depth and volume, respectively. For the piezoelectric ultrasonic system operating a Perioprobe insert, the corresponding mean values were 352.0 μm/12.1 μm/56.4 μm3 and for the universal Type‐A insert they were 402.4 μm/14.0 μm/133.4 μm3. With application forces of 0.7 N, root substance removal increased up to twofold.

Conclusion: The present investigation could demonstrate that the aggressiveness of magnetostrictive and piezoelectric ultrasonic devices to root substance was significantly influenced by the scaler tip designs, increasing for wider scaler tips as compared with narrow, probe‐shaped inserts.
Effects of post‐surgical cleansing protocols on early plaque control in periodontal and/or periimplant wound healing
Authors: Heitz F. , Heitz‐Mayfield L. J. A. , Lang N. P.
Published: October 2004

Objective:The aim of this RCT was to evaluate early wound healing following specific post‐surgical care protocols.

Material and Methods:Following periodontal flap surgery, 60 patients were randomly assigned to follow one of two post‐surgical protocols. Subjects smoking >20 cigarettes per day were excluded. Patients following the control protocol rinsed twice daily for 1 min with 0.1% of chlorhexidine (CHX) for 4 weeks. In addition to CHX rinsing, patients assigned to the test protocol applied CHX locally using a special very soft surgical toothbrush (Chirugia®) from days 3 to 14, and a soft toothbrush (Ultrasuave®) from days 14 to 28, twice daily. Baseline measurements included gingival crevicular fluid (GCF) flow rate, probing depth, probing attachment level, presence of bleeding on probing and full‐mouth plaque score. Measurements were repeated at 1, 2 and 4 weeks after surgery.

Results:Both post‐surgical protocols resulted in successful wound healing and optimal wound closure at 4 weeks. There were no statistical differences in the GCF flow rate between test and control protocols. There was a lower incidence of recession of 2 mm following the test protocol.

Conclusion:The use of specific post‐surgical cleansing protocols including the introduction of mechanical cleansing at day 3, using local application of CHX in addition to daily rinsing with CHX may be recommended.
The involvement of platelet‐derived growth factor receptors and insulin‐like growth factor‐I receptors signaling during mineralized nodule formation by human periodontal ligament cells
Authors: Nemoto Eiji , Shimonishi Mitsuru , Nitta Yasutaka , Shimauchi Hidetoshi
Published: October 2004

Background and objective:  Periodontal ligament cells are regarded to have the capacity to differentiate into cementoblasts or osteoblasts, and are capable of forming a mineralized nodule in vitro. However, the precise mechanisms are unclear. Here we evaluated the possible involvement of growth factor receptors, such as the platelet‐derived growth factor receptor (PDGFR), insulin‐like growth factor‐I receptor (IGF‐IR), and epidermal growth factor receptor (EGFR) on periodontal ligament cells and their ligands during periodontal ligament cells differentiation in vitro.

Methods:  Human periodontal ligament cells were differentiated via culturing in the presence of dexamethasone, ascorbic acid, and β‐glycerophosphate for mineralized nodule formation, characterized by von Kossa staining. Expressions of receptors and their ligands were analyzed by flow cytometry/reverse transcription‐polymerase chain reaction.

Results:  During the differentiation, PDGFR‐α was held at a lower level compared with the control. PDGFR‐β, however, was maintained at a slightly higher level that was reversed to the control level when mineralized nodules formed. In contrast, IGF‐IR and EGFR were not substantially different from the control. The mineralized nodule formation was strongly inhibited by a PDGFR kinase blocker (AG1295 and AG1296), partially inhibited by an IGF‐IR kinase blocker (I‐Ome‐AG538 and AG1024), and not inhibited by an EGFR kinase blocker (AG99). PDGF‐A, PDGF‐C, PDGF‐D, IGF‐I, and IGF‐II, but not PDGF‐B, were expressed on the control as well as dexamethasone/ascorbic acid‐treated periodontal ligament cells during mineralized nodule formation; however, the pattern of their expressions was quite different.

Conclusion:  These findings suggest that a pathway of PDGFs/PDGFR and IGFs/IGF‐IR on periodontal ligament cells are involved during mineralized nodule formation, and that PDGFs and IGFs expressed by periodontal ligament cells may contribute to the formation.