Previous studies examined the serum immunoglobulin levels in relation to coronary artery disease (CAD). We hypothesized that the salivary immunoglobulins might better estimate oral infections in this relationship. Multivariate logistic regression analyses utilizing the data from 256 angiographically confirmed CAD patients and 250 non-CAD individuals that controlled for age, sex, smoking, diabetes, total/HDL cholesterol ratio, hypertension, and education revealed the trends that salivary IgA was positively and salivary IgG was inversely associated with CAD. The odds ratios (OR) of each increasing quartile of salivary IgA were 1.00 (first and second quartiles combined), 1.97, and 1.37 (p-value for trend = 0.06), while those for salivary IgG were 1.00, 0.77, 0.60, and 0.51 (p-value for trend = 0.02). Additionally, salivary IgA correlated positively with C-reactive protein and Asymptotic Dental Score (dental infection score), while IgG was inversely associated with these inflammation markers. Salivary IgA warrants further studies to confirm its role in the risk assessment of CAD.

Although the etiology of essential hypertension is not clearly understood, endothelial dysfunction from chronic infection and/or impaired glucose metabolism may be involved. We hypothesized that salivary lysozyme, a marker for oral infection and hyperglycemia, might display a significant relationship with hypertension, an early stage of cardiovascular disease. Logistic regression analyses of the Kuopio Oral Health and Heart Study demonstrated that persons with higher lysozyme levels were more likely to have hypertension, after adjustment for age, gender, smoking, BMI, diabetes, the ratio of total cholesterol to HDL cholesterol, and C-reactive protein. The exposure to increasing quartiles of lysozyme was associated with adjusted Odds Ratios for the outcome, hypertension, 1.00 (referent), 1.25, 1.42, and 2.56 (linear trend p < 0.003). When we restricted the sample to the individuals without heart disease (N = 250), we observed a non-significant trend for increasing odds. Our hypothesis-"high salivary lysozyme levels are associated with the odds of hypertension"-was confirmed.

The Maule, Chile, (Mw 8.8) earthquake on 27 February 2010 triggered deformation events over a broad area, allowing investigation of stress redistribution within the upper crust following a mega-thrust subduction event. We explore the role that the Maule earthquake may have played in triggering shallow earthquakes in northwestern Argentina and Chile. We investigate observed ground deformation associated with the Mw 6.2 (GCMT) Salta (1450 km from the Maule hypocenter, 9 h after the Maule earthquake), Mw 5.8 Catamarca (1400 km; nine days), Mw 5.1 Mendoza (350 km; between one to five days) earthquakes, as well as eight additional earthquakes without an observed geodetic signal. We use seismic and Interferometric Synthetic Aperture Radar (InSAR) observations to characterize earthquake location, magnitude and focal mechanism, and characterize how the non-stationary, spatially correlated noise present in the geodetic imagery affects the accuracy of our parameter estimates. The focal mechanisms for the far-field Salta and Catamarca earthquakes are broadly consistent with regional late Cenozoic fault kinematics. We infer that dynamic stresses due to the passage of seismic waves associated with the Maule earthquake likely brought the Salta and Catamarca regions closer to failure but that the involved faults may have already been at a relatively advanced stage of their seismic cycle. The near-field Mendoza earthquake geometry is consistent with triggering related to positive static Coulomb stress changes due to the Maule earthquake but is also aligned with the South America-Nazca shortening direction. None of the earthquakes considered in this study require that the Maule earthquake reactivated faults in a sense that is inconsistent with their long-term behavior.

Findings from gene expression profiling studies are leading to new diagnostic and therapeutic strategies that can be applied in medical practice, especially in the field of oncology. Promising results of gene expression profiling of the peripheral blood in patients with ischaemic stroke have been obtained in recent pilot studies, demonstrating a partially reproducible gene signature of acute cerebral ischaemia. However, questions remain. Given that blood is at least in part a surrogate tissue for ischaemic stroke, the specificity of these signatures needs to be evaluated. Furthermore, it needs to be determined whether standardization of this methodology is required and whether clinical signatures can be identified that are improvements over the tools currently used in clinical practice. Clinically useful signatures would include those of haemorrhagic as well as ischaemic stroke, reclassification of stroke type and prognosis, and vascular disease risk. if these conditions are met, then it should be possible to develop cost-effective and rapid assays.

Summary.  Background: Endothelial membrane microparticles (EMP) in plasma are elevated in several vascular diseases. Objectives: To test the hypothesis that EMP would be increased in patients with acute ischemic stroke and would correlate with stroke severity, brain lesion volume and outcome. Patients and methods: Forty‐one patients were studied and divided into two groups based on the National Institutes of Health Stroke Scale (NIHSS) score: 20 patients with mild stroke (NIHSS score < 5) and 21 patients with moderate–severe stroke (NIHSS score ≥ 5). Lesion volume was measured using diffusion‐weighted magnetic resonance imaging and discharge outcome was based on the discharge Barthel and Rankin scores. Twenty‐three age‐matched control subjects were also studied. Using flow cytometry, endoglin‐positive EMP: CD105+ CD41a−CD45− (E+EMP), specific endothelial EMP expressing VE‐cadherin and endoglin: CD105+CD144+ (C+EMP), EMP expressing phosphatidylserine: CD105+PS+ CD41a− (PS+EMP) and EMP expressing ICAM‐1: CD105+CD54+ CD45− (I+EMP) were analyzed. Results: Significantly higher PS+EMP counts were observed in the group of acute ischemic stroke patients [median 59 (25th–75th percentile: 28–86) MP μL−1] relative to the controls [28 (14–36) MP μL−1] (P = 0.002). All four EMP phenotypes studied were elevated in the subgroup of moderate–severe stroke patients relative to the controls (all P < 0.05). In the patients with acute ischemic stroke three EMP phenotypes (E+EMP, PS+EMP and I+EMP) correlated significantly with brain lesion volume, with I+EMP (P = 0.002) showing the strongest correlation. Admission counts of C+EMP (P = 0.0003) and E+EMP (P = 0.003) correlated significantly with discharge clinical outcome. Conclusions: Certain circulating EMP phenotypes may be associated with severity, lesion volume and outcome of acute ischemic stroke. EMP analysis shows promising contribution to understanding stroke pathophysiology.

Inflammation is recognized as a key player in the development of atherosclerosis and is increasingly believed to contribute to reperfusion injury and delayed ischemia in the brain after stroke. The immune system is overwhelmingly complex; clinical interest in stroke and vascular disease has focused particularly on the roles played by specific immune cells and cytokines. Monocyte-macrophages and lymphocytes are the major immune cells within atherosclerotic lesions.1 Neutrophils and monocyte-macrophages are believed to exacerbate stroke-related ischemia-reperfusion injury.2 However, lymphocytes are key and versatile regulators of the immune system; their role during ischemic stroke may have been underappreciated. Evidence is now beginning to emerge that lymphocytes may have a greater and earlier involvement during stroke, opening the door for novel and highly specific targets for diagnostic, management, treatment, and prevention strategies for both stroke and vascular disease. Article p 2105 When the immune system becomes activated, a delicate balance between inflammatory and antiinflammatory states is maintained by the innate (nonspecific) and adaptive immune systems. The adaptive immune system is characterized by its ability to alter receptor expression and cellular functions when encountering new antigens, whether self or foreign; functions include cell-mediated immunity, humoral immunity, immune response regulation, memory, and immunological tolerance. Cells of the adaptive immune system include T-cell lymphocytes (helper T cells [generally CD4+] and cytotoxic T cells [generally CD8+]), natural killer cells, and B-cell lymphocytes. After antigenic activation, CD4+ T cells can be differentiated into at least 3 subsets: Th1 (which are involved in cell-mediated immunity and secrete proinflammatory cytokines such as gamma-interferon [γ-IFN], interleukin [IL]-2, and lymphotoxin), Th2 (which …

To the Editor: Total leukocyte count in the peripheral blood has been reported to be a significant predictor of future cardiac events and mortality.1 Leukocyte-derived salivary lysozyme has been associated with oral infection,2 and serum lysozyme has been implicated in impaired glucose metabolism,3 a contributory factor for endothelial dysfunction.4 We postulated that salivary lysozyme, therefore, would be associated with coronary heart disease (CHD). This study was approved by the joint ethical committee of the Kuopio University Hospital and the University of Kuopio. We investigated the relationship between the CHD and lysozyme levels in a case-control study of 250 angiographically confirmed CHD patients and 250 sex- and age-matched controls, adjusting for age, sex, smoking, body mass index (BMI), diabetes mellitus, total cholesterol/high-density lipoprotein (HDL) cholesterol, hypertension, and serum C-reactive protein (CRP) levels ≥10 mg/L or ≥3 mg/L using logistic regression analyses. To assess the specific contribution of oral health through impaired glucose metabolism, we controlled for the Asymptotic Dental Score (ADS), an estimate of oral infection burden, comprising 5 major oral pathologies, namely pericoronitis, gingivitis, dental caries, root remnants, and the edentulous state.5 The basic characteristics of the cohort (Table I, available online at http://atvb.ahajournals.org) and cross-tabulation of lysozyme levels and other vascular risk factors are presented online (Table II, available online at http://atvb.ahajournals.org). After adjustment for established cardiac risk factors including age, sex, smoking, total cholesterol/HDL cholesterol, diabetes, hypertension, BMI, and CRP, odds ratios (ORs) with 95% CIs for the association between salivary lysozyme and CHD increased from 1.00 (the reference group) to 1.16 (0.51 to 2.63), 1.82 (0.83 to 4.01), and 3.62 (1.60 to 8.16) from the lowest to highest quartiles of salivary lysozyme (P value for linear trend <0.0001; Figure; Table III, available online at http://atvb. ahajournals.org). Models using log-transformed lysozyme or omitting the intermediate variables such as diabetes or hypertension generated similar results. When we adjusted for the ADS, the ORs (CI) decreased slightly to 1.00, 1.12 (0.48 to 2.62), 1.92 (0.85 to 4.34), and 3.45 (1.50 to7.93). When we adjusted for CRP using a threshold of 3 mg/L, the OR for the fourth quartile of lysozyme decreased to 2.73 (1.53 to 4.87) compared with the other 3 quartiles combined and the C-statistic also decreased, suggesting a reduced explanatory ability of CRP at 3 mg/L. Salivary lysozyme conferred a much stronger association with CHD than the ADS oral infection score. We hypothesize that this additional risk increase might be attributable to impaired glucose metabolism and subsequent accumulation of advanced glycation end products (AGE) as depicted in the conceptual model (Figure I, available online at http://atvb.ahajournals.org). However, this hypothesis calls for further prospective studies. Lysozyme is secreted locally, and there is no significant correlation between serum and salivary lysozyme.6 Salivary lysozyme may underscore dual pathways by which poor oral health may contribute to CHD pathogenesis.5 Poor dentition is a limiting factor for adequate intake of beneficial nutrients to prevent CHD (ie, fiber,7 antioxidants,8,9 and fruits and vegetables10). Moreover, edentulism encourages high fat and carbohydrate intake,11,12 thus, it may contribute to a higher level of AGE and subsequent CHD.13-15 The conclusion of our meta-analysis,16 that persons with periodontal disease might be at a higher risk of developing cardiovascular disease, has been corroborated by several recent trials reporting that periodontal treatment decreased the level of systemic CRP17-19 and further by other immunologic studies that linked the periodontal pathogen Porphyromonas gingivalis to atherosclerosis.20-22 Leukocytes may play a role in cardiopathogenesis, as Kowolik et al23 and Margolis et al24 concurred. Salivary lysozyme may be a marker for the dual contribution of oral leukocytes to cardiopathogenesis, via infection and elevated AGE deriving from an unhealthy diet. In conclusion, increased quartiles of salivary lysozyme, which may be a consequence of oral infection or impaired glucose metabolism, were associated with increasing ORs (1.00, 1.16, 1.82, and 3.62, respectively, P for trend <0.0001) for CHD after controlling for traditional CHD risk factors. Further prospective investigations are warranted to establish whether this is a causal relationship.

BACKGROUND:Contrast-enhanced MR angiography (CE-MRA) using a combined head and neck coil permits non-invasive imaging of the vasculature from the aortic arch through to the Circle of Willis in less than 2 minutes. OBJECTIVE:To determine the accuracy of CE-MRA for the detection of vascular pathology, in particular vascular stenoses, using digital subtraction angiography (DSA) as the gold standard. METHODS:In a prospective study of 81 patients referred for DSA, CE-MRA and DSA studies were performed within 72 hours of each other. CE-MRA was performed on a 1.5 Tesla clinical MRI scanner using a five-channel neurovascular array (head and neck coil), with dynamic tracking of the IV gadolinium bolus. CE-MRAs and DSA films were read by two interventional neuroradiologists blinded to the clinical presentation of the patient. RESULTS:On DSA, there were 77 vascular stenoses > or =50% identified, 51 extracranial and 26 intracranial. The overall sensitivity of CE-MRA using the neurovascular array for the detection of vascular stenoses > or =50% was 57% (95% CI: 46 to 68%) with a specificity of 98% (97 to 99%). The sensitivity for the detection of extracranial vascular stenoses > or =50% was 82% (72 to 93%) with a specificity of 97% (96 to 98%). However, the sensitivity for the detection of intracranial vascular stenoses > or =50% was only 8% (0 to 18%), with a specificity of 99% (98 to 100%). CONCLUSIONS:At this stage Contrast-enhanced MR angiography using a neurovascular coil shows promise as a rapid, specific, and noninvasive screening method for extracranial vascular disease, but not for intracranial vascular disease.

Previous analyses regarding effects of periodontal treatment on glycemic control included studies where causal association might not be assumed, or the results were reported non-quantitatively. We initiated this meta-analysis of 10 intervention studies to quantify the effects of periodontal treatment on HbA1c level among diabetic patients, to explore possible causes for the discrepant reports, and to make recommendations for future studies. Data sources were MEDLINE (January, 1980, to January, 2005), the EBMR, Cochrane Register, and bibliographies of the published articles. Three investigators extracted data regarding intervention, outcomes, and effect size. A total of 456 patients was included in this analysis, with periodontal treatment as predictor and the actual change in hemoglobin A1c level as the outcome. The weighted average decrease in actual HbA1c level was 0.38% for all studies, 0.66% when restricted to type 2 diabetic patients, and 0.71% if antibiotics were given to them. However, none was statistically significant.

Background— Direct brain biopsy is rarely indicated during acute stroke. This study uses peripheral blood mononuclear cells (PBMCs) to determine whether a systemic gene expression profile could be demonstrated in patients with acute ischemic stroke. Methods and Results— Using oligonucleotide microarrays, we compared the gene expression profile of an index cohort of 20 patients with confirmed ischemic stroke on neuroimaging studies with that of 20 referent subjects. Validation studies used quantitative real-time polymerase chain reaction to measure the levels of 9 upregulated genes in the index cohort, and an independent cohort of 9 patients and 10 referent subjects was prospectively studied to determine the accuracy of the Prediction Analysis for Microarrays list to classify stroke. After correction for multiple comparisons with the Bonferroni technique, 190 genes were significantly different between the stroke and referent groups. Broad classes of genes included white blood cell activation and differentiation (≈60%), genes associated with hypoxia and vascular repair, and genes potentially associated with an altered cerebral microenvironment. Real-time polymerase chain reaction confirmed increased mRNA expression in 9 of 9 upregulated stroke-associated genes in the index cohort. A panel of 22 genes derived from the Prediction Analysis for Microarrays algorithm in the index cohort classified stroke in the validation cohort with a sensitivity of 78% and a specificity of 80%. Control for the Framingham stroke risk score revealed only a partial dependence of the stroke gene expression profile in PBMCs on vascular risk. Conclusions— This study demonstrated an altered gene expression profile in PBMCs during acute ischemic stroke. Some genes with altered expression were consistent with an adaptive response to central nervous system ischemia.

Objective: To determine if the CD4(+) CD28(-) T-cell subset is expanded in patients with recurrent stroke or death after acute ischemic stroke. This subset of the peripheral blood T-cell lymphocyte population has a strong pro-inflammatory and tissue-damaging potential. Methods: Consecutive patients within the first 48 hours of ischemic stroke were prospectively studied. Peripheral blood CD4(+) CD28(-) cells were quantified by flow cytometry. The study endpoint was recurrent stroke or death from any cause during 1 year of follow-up. Results: One hundred six patients (mean age 75.0 +/- 13.5 years; 50 women) were studied. The median CD4(+)CD28(-) cell count was 4.5% (range 0.2 to 72.2%). Twenty-seven endpoints (10 recurrent strokes and 17 deaths) occurred during follow-up. Stroke recurrence/death rates were significantly associated with increasing CD4(+)CD28(-) counts, rising from 14.2% in patients with CD4(+)CD28(-) levels of <1.0 to 48.1% for those with CD4(+)CD28(-) counts of <8.0% (p = 0.003, Cochran linear test of trend). Higher CD4(+)CD28(-) counts were also present in patients with a history of prior stroke (p = 0.03). After adjustment for age, admission NIH Stroke Scale score, prior stroke, and atrial fibrillation, CD4(+)CD28(-) counts of <8.0% were associated with a cumulative hazard ratio of 5.81 (95% CI: 1.58 to 21.32) for stroke recurrence or death. Conclusions: Rising counts of circulating CD4(+)CD28(-) cells are associated with an increasing risk of stroke recurrence and death, in addition to an observed association with prior stroke. Expansion of this T-cell subset presumably represents a biomarker and possibly a contributory pathogenic mechanism of recurrent stroke and death after ischemic stroke.