Formation of caries-like lesions in vitro on the root surfaces of human teeth in solutions simulating plaque fluid

Lesion formation on root surfaces of human posterior teeth was studied in acetate/lactate buffers with a background electrolyte composition based on plaque fluid analyses. Lesion depth after 28 days at 37 degrees C was measured in relation to: the presence or absence of cementum; the concentration of undissociated buffer; the presence or absence of magnesium ions at plaque fluid concentration. Each factor was evaluated at several values of -log(ion activity product for hydroxyapatite): pI(HA). Solutions were formulated to minimize variation in pH, which varied by < or =0.03 for a given comparison (individual pI(HA)) and by 0.42-0.82 over the range of pI(HA) within experiments. Lesions on surfaces from which cementum had been ground were significantly deeper than on intact surfaces, but this is considered to be due to subsurface mechanical damage and not to a solubility difference. Neither the concentration of undissociated buffer nor the presence of magnesium ions significantly affected lesion depth. Lesion depth was strongly influenced by the correlated variations in pI(HA) and pH. At pI(HA) 54 and 55, only extremely shallow lesions formed. From pI(HA) 56, lesion depth increased with increasing pI(HA). The results confirm that the solubility of the mineral of root tissues is higher than that of hydroxyapatite, but indicate that it is probably lower than suggested by Hoppenbrouwers et al. [Arch Oral Biol 1987;32:319-322]. For calcium concentrations of 3-12 mM, the critical pH for root tissue mineral was calculated as 5.22-5.66 assuming solubility equivalent to pI(HA) 54 and 5.08-5.51 assuming pI(HA) 55.

Reliability and discriminatory power of methods for dental plaque quantification

This in situ study evaluated the discriminatory power and reliability of methods of dental plaque quantification and the relationship between visual indices (VI) and fluorescence camera (FC) to detect plaque.

Carotid plaque in Alzheimer caregivers and the role of sympathoadrenal arousal

To test the hypothesis that those who provide care for a spouse diagnosed with Alzheimer's disease would have increased prevalence of carotid artery plaque compared with noncaregiving controls and that prolonged sympathoadrenal arousal to acute stress would relate to this difference. Providing care for a spouse with Alzheimer's disease has been associated with an increased risk of coronary heart disease, potentially due to the impact of caregiving stress on the atherosclerotic disease process.

Plaque characteristics of nonobstructive coronary lesions in diabetic patients: an intravascular ultrasound virtual histology analysis

Patients with diabetes mellitus are known to be at increased risk for acute cardiovascular events. We used intravascular ultrasound virtual histology (IVUS-VH) to examine whether nonobstructive coronary artery lesions of diabetic patients have distinct plaque composition and morphology compared with nondiabetic patients.

Temporal changes of coronary artery plaque located behind the struts of the everolimus eluting bioresorbable vascular scaffold

Implantation of a coronary stent results in a mechanical enlargement of the coronary lumen with stretching of the surrounding atherosclerotic plaque. Using intravascular ultrasound virtual-histology (IVUS-VH) we examined the temporal changes in composition of the plaque behind the struts (PBS) following the implantation of the everolimus eluting bioresorbable vascular scaffold (BVS). Using IVUS-VH and dedicated software, the composition of plaque was analyzed in all patients from the ABSORB B trial who were imaged with a commercially available IVUS-VH console (s5i system, Volcano Corporation, Rancho Cordova, CA, USA) post-treatment and at 6-month follow-up. This dedicated software enabled analysis of the PBS after subtraction of the VH signal generated by the struts. The presence of necrotic core (NC) in contact with the lumen was also evaluated at baseline and follow-up. IVUS-VH data, recorded with s5i system, were available at baseline and 6-month follow-up in 15 patients and demonstrated an increase in both the area of PBS (2.45 ± 1.93 mm(2) vs. 3.19 ± 2.48 mm(2), P = 0.005) and the external elastic membrane area (13.76 ± 4.07 mm(2) vs. 14.76 ± 4.56 mm(2), P = 0.006). Compared to baseline there was a significant progression in the NC (0.85 ± 0.70 mm(2) vs. 1.21 ± 0.92 mm(2), P = 0.010) and fibrous tissue area (0.88 ± 0.79 mm(2) vs. 1.15 ± 1.05 mm(2), P = 0.027) of the PBS. The NC in contact with the lumen in the treated segment did not increase with follow-up (7.33 vs. 6.36%, P = 0.2). Serial IVUS-VH analysis of BVS-treated lesions at 6-month demonstrated a progression in the NC and fibrous tissue content of PBS.

Carotid plaque and intima-media thickness and the incidence of ischemic events in patients with atherosclerotic vascular disease

We aimed to evaluate whether carotid intima-media thickness (CIMT) or the presence of plaque can confer additional predictive value of future cardiovascular (CV) ischemic events in patients with pre-existing atherosclerotic vascular disease. We identified 2317 patients enrolled in the REduction of Atherothrombosis for Continued Health (REACH) registry who had atherosclerotic vascular disease and baseline CIMT measurements. The entire range of CIMT was divided into quartiles and the fourth quartile (? 1.5 mm) was defined as carotid plaque. Mean ± standard deviation baseline CIMT was 1.31 ± 0.65 mm. Associated CV ischemic events and vascular-related hospitalizations were evaluated over a 2-year follow-up. There was a positive increase in adjusted hazard ratios (HRs) for all-cause mortality (p = 0.04 for trend) and the quadruple endpoint (CV death, myocardial infarction (MI), stroke, hospitalization for CV events) with increasing quartiles of CIMT (p = 0.0008 for trend), which was mainly driven by the fourth quartile (carotid plaque). HRs for all-cause mortality, CV death, CV death/MI/stroke and the quadruple endpoint comparing the highest (carotid plaque) with the lowest CIMT quartile were 2.09 (95% CI, 1.07-4.10; p = 0.03); 2.49 (1.10-5.67; p = 0.03); 1.71 (1.10-2.67; p = 0.02); and 1.73 (1.31-2.27; p = 0.0001). In conclusion, our analyses suggest that the presence of carotid plaque, rather than the thickness of intima-media, appears to be associated with increased risk of CV morbidity and mortality, but confirmation of these findings in other population and prospective studies is required.

Efficacy and safety of the Betamethasone valerate 0.1% plaster in mild-to-moderate chronic plaque psoriasis: a randomized, parallel-group, active-controlled, phase III study

Corticosteroids are a versatile option for the treatment of mild-to-moderate psoriasis due to their availability in a wide range of potencies and formulations. Occlusion of the corticosteroid is a widely accepted procedure to enhance the penetration of the medication, thereby improving its effectiveness. Betamethasone valerate (BMV) is a moderately potent corticosteroid that is available as a cream, ointment, and lotion. A ready-to-use occlusive dressing, which provides a continuous sustained release of BMV, has been developed for the treatment of psoriasis.

Analysis of 1 year virtual histology changes in coronary plaque located behind the struts of the everolimus eluting bioresorbable vascular scaffold

Serial intravascular ultrasound virtual histology (IVUS-VH) after implantation of metallic stents has been unable to show any changes in the composition of the scaffolded plaque overtime. The everolimus-eluting ABSORB scaffold potentially allows for the formation of new fibrotic tissue on the scaffolded coronary plaque during bioresorption. We examined the 12 month IVUS-VH changes in composition of the plaque behind the struts (PBS) following the implantation of the ABSORB scaffold. Using IVUS-VH and dedicated software, the composition of the PBS was analyzed in all patients from the ABSORB Cohort B2 trial, who were imaged with a commercially available IVUS-VH console (s5i system, Volcano Corporation, Rancho Cordova, CA, USA), immediately post-ABSORB implantation and at 12 month follow-up. Paired IVUS-VH data, recorded with s5i system, were available in 17 patients (18 lesions). The analysis demonstrated an increase in mean PBS area (2.39 ± 1.85 mm(2) vs. 2.76 ± 1.79 mm(2), P = 0.078) and a reduction in the mean lumen area (6.37 ± 0.90 mm(2) vs. 5.98 ± 0.97 mm(2), P = 0.006). Conversely, a significant decrease of 16 and 30% in necrotic core (NC) and dense calcium (DC) content, respectively, were evident (median % NC from 43.24 to 36.06%, P = 0.016; median % DC from 20.28 to 11.36%, P = 0.002). Serial IVUS-VH analyses of plaque located behind the ABSORB struts at 12-month demonstrated an increase in plaque area with a decrease in its NC and DC content. Larger studies are required to investigate the clinical impact of these findings.

Associations of Reactive Hyperemia Index and Intravascular Ultrasound-Assessed Coronary Plaque Morphology in Patients With Coronary Artery Disease

Although reactive hyperemia index (RHI) predicts future coronary events, associations with intravascular ultrasound (IVUS)-assessed coronary plaque structure have not been reported. This study therefore investigated associations between RHI and IVUS-assessed coronary plaques. In 362 patients RHI was measured by noninvasive peripheral arterial tonometry and coronary plaque components (fibrous, fibrofatty, necrotic core, and dense calcium) were identified by IVUS in 594 vessel segments of the left anterior descending, circumflex, and/or right coronary arteries. RHI values <1.67 were considered abnormal. Analysis of variance was used to detect independent associations between RHI and plaque composition. Patients with an abnormal RHI had greater plaque burden (41% vs 39% in patients with normal RHI, p = 0.047). Compared to patients with normal RHI, plaque of patients with abnormal RHI had more necrotic core (21% vs 17%, p <0.001) and dense calcium (19% vs 15%, p <0.001) and less fibrous (49% vs 54%, p <0.001) and fibrofatty (11% vs 14%, p = 0.002) tissue. After adjustment for age, gender, cardiovascular risk factors, and drug therapy, abnormal RHI remained significantly associated with fibrous (F ratio 14.79, p <0.001), fibrofatty (F ratio 5.66, p = 0.018), necrotic core (F ratio 14.47, p <0.001), and dense calcium (F ratio 10.80, p = 0.001) volumes. In conclusion, coronary artery plaques of patients with abnormal RHI had a larger proportion of necrotic core and dense calcium. The association of an abnormal RHI with a plaque structure that is more prone to rupture may explain why these patients exhibit a greater risk of coronary events.

Antibacterial effect of taurolidine (2%) on established dental plaque biofilm

Preliminary data have suggested that taurolidine may bear promising disinfectant properties for the therapy of bacterial infections. However, at present, the potential antibacterial effect of taurolidine on the supragingival plaque biofilm is unknown. To evaluate the antibacterial effect of taurolidine on the supragingival plaque biofilm using the vital fluorescence technique and to compare it with the effect of NaCl and chlorhexidine (CHX), 18 subjects had to refrain from all mechanical and chemical hygiene measures for 24 h. A voluminous supragingival plaque sample was taken from the buccal surfaces of the lower molars and wiped on an objective slide. The sample was then divided into three equal parts and mounted with one of the three test or control preparations (a) NaCl, (b) taurolidine 2% and (c) CHX 0.2%. After a reaction time of 2 min, the test solutions were sucked of. Subsequently, the plaque biofilm was stained with fluorescence dye and vitality of the plaque flora was evaluated under the fluorescence microscope (VF%). Plaque samples treated with NaCl showed a mean VF of 82.42 ± 6.04%. Taurolidine affected mean VF with 47.57 ± 16.60% significantly (p < 0.001, paired t test). The positive control CHX showed the lowest mean VF values (34.41 ± 14.79%; p < 0.001 compared to NaCl, p = 0.017 compared to taurolidine). Taurolidine possesses a significant antibacterial effect on the supragingival plaque biofilm which was, however, not as pronounced as that of CHX.

Plaque Characteristics of Asymptomatic Carotid Stenosis and Risk of Stroke

The optimal treatment of asymptomatic carotid stenosis (ACS) is controversial. To optimize the risk-benefit ratio of carotid artery revascularization, it is crucial to identify ACS patients who are at increased stroke risk. Recent data suggest that plaque vulnerability depends on its composition. Therefore, we assessed plaque composition in ACS to determine predictors for ipsilateral cerebrovascular events.

Impact of carotid plaque screening on smoking cessation and other cardiovascular risk factors: a randomized controlled trial

Screening of peripheral atherosclerosis is increasingly used, but few trials have examined its clinical impact. We aimed to assess whether carotid plaque screening helps smokers to improve their health behaviors and cardiovascular risk factors.

Secondary stroke prevention: patent foramen ovale, aortic plaque, and carotid stenosis

Stroke is the most debilitating cardiovascular event. It has a variety of causes that may be present simultaneously. In young or otherwise healthy people, the search for a patent foramen ovale (PFO) has become standard. In stroke of the elderly, atherosclerosis and atrial fibrillation are in the foreground but the PFO should not be ignored. The risk of a PFO-related stroke over time is controversial and so is its prevention by device closure. The association of proximal aortic plaques in arteries subtending the brain and stroke is considered strong, ignoring that it is as putative as that of the PFO. Statins can prevent progression of such plaques. Antiplatelet agents in asymptomatic and surgical endarterectomy in symptomatic patients or highly ulcerated lesions are the treatment of choice. Stenting with protection devices was shown competitive in selected patients.

Circumferential evaluation of the neointima by optical coherence tomography after ABSORB bioresorbable vascular scaffold implantation: can the scaffold cap the plaque?

To quantify the circumferential healing process at 6 and 12 months following scaffold implantation.