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Multiple Comparisons (multiple + comparison)
Terms modified by Multiple Comparisons Selected AbstractsEffect of administration mode (patient vs physician) and patient's educational level on the Turkish version of the International Prostate Symptom ScoreINTERNATIONAL JOURNAL OF UROLOGY, Issue 8 2002Murat Bozlu Abstract Objectives: To compare the effectiveness of the International Prostate Symptom Score (IPSS) when administered by the physician to when self-administered by the patient. The effect of the patient's educational level on the IPSS was also evaluated. Methods: One hundred and seven previously untreated patients with symptomatic benign prostatic hyperplasia (BPH) completed the Turkish version of the International Prostate Symptom Score (Turkish I-PSS) and quality of life (QOL) questionnaires during a single office visit, first on their own and then with an interviewing physician. The patients were categorized into three groups according to their educational levels. Paired t -tests were performed to compare the total IPSS (tIPSS) and QOL results between the two testing modes. IPSS and QOL scores resulting from both modes were compared using a kappa test. Differences between the physician-assisted and self-administered scores among the different educational groups were further compared using a one-way anova test and Post Hoc Multiple Comparisons. To compare the objective effectiveness of tIPSS and QOL between the two testing modes, we selected the positive actual state, which was maximum urine flow (Qmax) of 15 mL/s or less and constructed receiver operating characteristics (ROC) curves for all patients. This estimation was constructed for each educational level. Results: There were no statistical differences in IPSS and QOL values obtained by the patients or physicians (P > 0.05). The ROC areas for tIPSS were 0.94 and 0.93, and the ROC areas for QOL scores were 0.97 and 0.91 for information obtained by physicians and patients, respectively. When IPSS answers and QOL scores were evaluated separately, consistency was found across both modes of administration. However, there were lower levels of consistency in answers to IPSS questions 2, 5 and 6 (P = 0.59;0.42; 0.52, respectively). There was no significant difference among the aforementioned data in the educational groups. Conclusion: Although the total IPSS and QOL scores were not affected by the different modes of administration, we recommend that the physicians should evaluate answers to questions 2, 5 and 6 carefully. The present study demonstrates that the educational level did not affect the IPSS and QOL when administered either by the physician or the patient. [source] The Likelihood as Statistical Evidence in Multiple Comparisons in Clinical Trials: No Free LunchBIOMETRICAL JOURNAL, Issue 3 2006Edward L. Korn Abstract The likelihood ratio summarizes the strength of statistical evidence for one simple pre-determined hypothesis versus another. However, it does not directly address the multiple comparisons problem. In this paper we discuss some concerns related to the application of likelihood ratio methods to several multiple comparisons issues in clinical trials, in particular, subgroup analysis, multiple variables, interim monitoring, and data driven choice of hypotheses. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Unfavorable lipid profiles in mild obesity with excess body fat percentagePEDIATRICS INTERNATIONAL, Issue 1 2000Akiho Tamura Abstract Background: The aim of the present study was to investigate the usefulness of subclassifications of overweight children using the body fat percentage (Fat%) to predict the serum lipid profile. Methods: School children (431, 236 boys and 195 girls) aged 9,12 years were divided into three obesity groups (non-, mild and advanced obesity) and were further divided into two subgroups according to the Fat% measured by bioelectrical impedance analysis. The mean fasting serum lipid levels were also evaluated. Results: In the non-obesity and the advanced obesity groups, the Fat%-based subclassification demonstrated no essential differences in lipid profiles or in the prevalence of hyperlipidemia between the two subgroups. However, in the mild obesity group, the levels of low-density lipoprotein cholesterol and triglyceride and the atherogenic index were significantly higher and the high-density lipoprotein cholesterol level was significantly lower in the adipositic subgroup (Fat%, age/sex-specific cut-off value) than in the non-adipositic subgroup. Multiple comparison of lipid levels among all six categories of children indicated that the adipositic subgroup of mild obesity had no advantage over the advanced obesity group with respect to the atherogenic potential and that the non-adipositic subgroup of mild obesity showed no additional risks compared to the non-obesity group. Moreover, the prevalence of hyperlipidemia in the adipositic subgroup of mild obesity (50.0%) was significantly different from that in its non-adipositic counterpart (13.3%) and was equivalent to that in the advanced obesity group. Conclusions: These results suggest that Fat% evaluation is useful to divide mildly obese children into two distinct subtypes based on serum lipid profiles and that the excess Fat% in mildly obese school children is a predictor of atherogenesis. [source] Effectiveness of different techniques for removing gutta-percha during retreatmentINTERNATIONAL ENDODONTIC JOURNAL, Issue 1 2005A. V. Masiero Abstract Aim, To evaluate the effectiveness of various techniques for removing filling material from root canals in vitro. Methodology, Eighty extracted mandibular premolar teeth were selected for the study. The teeth were root filled using thermomechanical compaction of gutta-percha. After 8 months, the filling material was removed and canals were reinstrumented using the following techniques: group I , hand instrumentation with K-type files (SybronEndo, Orange, CA, USA); group II , K3 Endo System (SybronEndo); group III , M4 system (SybronEndo) with K-type files (SybronEndo); and group IV , Endo-gripper system (Moyco Union Broach, York, PA, USA) with K-type files (SybronEndo). The amount of filling debris remaining on root canal walls was assessed radiographically; the images were digitized and analysed using AutoCAD 2000 software. Total canal area, area of the cervical, middle and apical thirds, and area of remaining filling material were outlined by one operator. The ratios between these areas were calculated as percentages of remaining debris. Thereafter, data were analysed by means of one-way anova and the post-hoc Duncan test to identify differences between the four techniques. Results, Multiple comparisons of the percentages of remaining filling material in the entire canal did not reveal any significant differences between the methods of removal. However, when each third was analysed separately, significant differences for remaining debris were present between groups. The apical third had the most remaining material, whilst the cervical and middle thirds were significantly cleaner (P = 0.002). Comparison of the techniques revealed that teeth instrumented with K3 rotary instruments had a lower ratio of remaining filling material in the apical third (P = 0.012). Conclusion, In the apical third, K3 rotary instruments were more efficient in removing gutta-percha filling material than the other techniques, which were equally effective for the other thirds. [source] Accounting for Multiplicities in Assessing Drug Safety: A Three-Level Hierarchical Mixture ModelBIOMETRICS, Issue 2 2004Scott M. Berry Summary. Multiple comparisons and other multiplicities are among the most difficult of problems that face statisticians, frequentists, and Bayesians alike. An example is the analysis of the many types of adverse events (AEs) that are recorded in drug clinical trials. We propose a three-level hierarchical mixed model. The most basic level is type of AE. The second level is body system, each of which contains a number of types of possibly related AEs. The highest level is the collection of all body systems. Our analysis allows for borrowing across body systems, but there is greater potential,depending on the actual data,for borrowing within each body system. The probability that a drug has caused a type of AE is greater if its rate is elevated for several types of AEs within the same body system than if the AEs with elevated rates were in different body systems. We give examples to illustrate our method and we describe its application to other types of problems. [source] Heart rate-lowering and -regulating effects of once-daily sustained-release diltiazemCLINICAL CARDIOLOGY, Issue 1 2001William E. Boden M.D. Abstract Background: Epidemiologic evidence suggests that an elevated heart rate (HR) is an adverse and independent prognostic factor in arterial hypertension and other cardiovascular diseases. Although diltiazem is characterized as an HR-lowering calcium antagonist, no studies have quantified the magnitude of HR changes in patients with angina or hypertension. Hypothesis: The study was undertaken to explore the magnitude of proportional HR reduction at varying levels of resting HR with the sustained-release formulation of diltiazem (SR diltiazem) at the usual clinical doses of 200 or 300 mg once daily. Methods: This meta-analysis was conducted on six comparative double-blind studies including 771 patients with angina or hypertension in which SR diltiazem 200,300 mg once daily was compared either with placebo or with other agents known not to influence HR (angiotensin-converting enzyme inhibitors, diuretics). Sustained-release diltiazem decreases elevated baseline HR, with an increasing effect at higher initial rates. Results: Multiple comparisons by baseline HR category showed a significant difference between both groups for baseline HR of 74,84 beats/min and , 85 beats/min (p = 0.001). Sustained-release diltiazem had no significant HR-decreasing effect on baseline HR , 74 beats/min but appears to have a genuine regulating effect on HR: it reduces tachycardia without inducing excessive bradycardia. These findings are in contrast to those with dihydropyridine calcium antagonists, which tend to increase HR and have been associated with an adverse outcome in acute cardiovascular conditions. At the same time, there is evidence to suggest that HR-lowering calcium-channel blockers decrease cardiovascular event rates following myocardial infarction. Conclusion: When calcium antagonists are indicated for use in patients with angina or hypertension, an HR-lowering agent, that is, diltiazem rather than dihydropyridine, should be recommended. [source] Confocal Examination of Subsurface Cracking in Ceramic MaterialsJOURNAL OF PROSTHODONTICS, Issue 7 2009MMedSc, Maged K. Etman DDS Abstract Purpose: The original ceramic surface finish and its microstructure may have an effect on crack propagation. The purpose of this study was to investigate the relation between crack propagation and ceramic microstructure following cyclic fatigue loading, and to qualitatively evaluate and quantitatively measure the surface and subsurface crack depths of three types of ceramic restorations with different microstructures using a Confocal Laser Scanning Microscope (CLSM) and Scanning Electron Microscope (SEM). Materials and Methods: Twenty (8 × 4 × 2 mm3) blocks of AllCeram (AC), experimental ceramic (EC, IPS e.max Press), and Sensation SL (SSL) were prepared, ten glazed and ten polished of each material. Sixty antagonist enamel specimens were made from the labial surfaces of permanent incisors. The ceramic abraders were attached to a wear machine, so that each enamel specimen presented at 45 degrees to the vertical movement of the abraders, and immersed in artificial saliva. Wear was induced for 80K cycles at 60 cycles/min with a load of 40 N and 2-mm horizontal deflection. The specimens were examined for cracks at baseline, 5K, 10K, 20K, 40K, and 80K cycles. Results: Twenty- to 30-,m deep subsurface cracking appeared in SSL, with 8 to 10 ,m in AC, and 7 ,m close to the margin of the wear facets in glazed EC after 5K cycles. The EC showed no cracks with increasing wear cycles. Seventy-,m deep subsurface cracks were detected in SSL and 45 ,m in AC after 80K cycles. Statistically, there was significant difference among the three materials (p < 0.05). Bonferroni multiple comparison of means test confirmed the ANOVA test and showed that there was no statistical difference (p > 0.05) in crack depth within the same ceramic material with different surface finishes. Conclusions: The ceramic materials with different microstructures showed different patterns of subsurface cracking. [source] A double-blind, randomized, dose response study testing the pharmacological efficacy of synthetic porcine secretinALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 12 2000P. S. Jowell Background: Biologically derived porcine secretin has been used as a diagnostic agent in clinical gastrointestinal practice for many years. Pure synthetic porcine secretin is now available for investigational clinical use. Aim: To compare the pharmacology of synthetic porcine secretin and biologically derived porcine secretin in healthy volunteers. Methods: Secretin stimulation tests were performed in 12 volunteer subjects in a double-blind, randomized, Latin square crossover design study comparing three doses of synthetic porcine secretin (0.05, 0.2, and 0.4 ,g/kg) with a standard dose of biologically derived porcine secretin (1 CU/kg). Duodenal aspirates were analysed for total volume and for bicarbonate concentration. Total bicarbonate output was calculated. Results: Twelve subjects completed four dosing regimens. A multiple comparison test was used to compare dosing regimens. The 0.2 and 0.4 ,g/kg doses of synthetic porcine secretin were not different from the 1 CU/kg dose of biologically derived porcine secretin for volume, bicarbonate concentration and total output from 0 to 60 min. Only one patient had an adverse event, which was mild, transient flushing after the 0.2 and 0.4 ,g/kg doses of synthetic porcine secretin and after the 1 CU/kg dose of biologically derived porcine secretin. Conclusions: Synthetic porcine secretin has identical pharmacologic effects to biologically derived porcine secretin in normal subjects. Both drugs were safe and well-tolerated. This study validates synthetic porcine secretin as a substitute for biologically derived porcine secretin. [source] Brain structural damage in spinocerebellar ataxia type 2.MOVEMENT DISORDERS, Issue 6 2008A voxel-based morphometry study Abstract Voxel-based morphometry (VBM) enables an unbiased in-vivo whole-brain quantitative analysis of differences in gray matter (GM), white matter (WM) and cerebro-spinal fluid (CSF) volumes. We assessed with VBM 20 spinocerebellar ataxia Type 2 (SCA2) patients with mild or moderate cerebellar deficit and 20 age and sex-matched healthy controls. SCA2 patients showed a significant (P < 0.05 corrected for multiple comparison) symmetric loss of GM in the cerebellar vermis and hemispheres sparing lobules I,II, Crus II,VII, and X, and of the WM in the peridentate region, middle cerebellar peduncles, dorsal pons, and cerebral peduncles. The CSF volume was increased in the posterior cranial fossa. No GM, WM or CSF volume changes were observed in the supratentorial compartment. A mild (P < 0.05, >0.01) correlation was observed between the GM and WM loss and severity of the neurological deficit. In SCA2 patients with mild to moderate cerebellar deficit, GM and WM volume loss and CSF volume increase are confined to the posterior cranial fossa. © 2008 Movement Disorder Society [source] Consistent Tests for Stochastic DominanceECONOMETRICA, Issue 1 2003Garry F. Barrett Methods are proposed for testing stochastic dominance of any pre,specified order, with primary interest in the distributions of income. We consider consistent tests, that are similar to Kolmogorov,Smirnov tests, of the complete set of restrictions that relate to the various forms of stochastic dominance. For such tests, in the case of tests for stochastic dominance beyond first order, we propose and justify a variety of approaches to inference based on simulation and the bootstrap. We compare these approaches to one another and to alternative approaches based on multiple comparisons in the context of a Monte Carlo experiment and an empirical example. [source] Brain Blood-flow Alterations Induced by Therapeutic Vagus Nerve Stimulation in Partial Epilepsy: II.EPILEPSIA, Issue 9 2004Low Levels of Stimulation, Prolonged Effects at High Summary:,Purpose: To measure vagus nerve stimulation (VNS)-induced cerebral blood flow (CBF) effects after prolonged VNS and to compare these effects with immediate VNS effects on CBF. Methods: Ten consenting partial epilepsy patients had positron emission tomography (PET) with intravenous [15O]H2O. Each had three control scans without VNS and three scans during 30 s of VNS, within 20 h after VNS began (immediate-effect study), and repeated after 3 months of VNS (prolonged study). After intrasubject subtraction of control from stimulation scans, images were anatomically transformed for intersubject averaging and superimposed on magnetic resonance imaging (MRI) for anatomic localization. Changes on t-statistical maps were considered significant at p < 0.05 (corrected for multiple comparisons). Results: During prolonged studies, CBF changes were not observed in any regions that did not have CBF changes during immediate-effect studies. During both types of studies, VNS-induced CBF increases were similarly located in the bilateral thalami, hypothalami, inferior cerebellar hemispheres, and right postcentral gyrus. During immediate-effect studies, VNS decreased bilateral hippocampal, amygdalar, and cingulate CBF and increased bilateral insular CBF; no significant CBF changes were observed in these regions during prolonged studies. Mean seizure frequency decreased by 25% over a 3-month period between immediate and prolonged PET studies, compared with 3 months before VNS began. Conclusions: Seizure control improved during a period over which some immediate VNS-induced CBF changes declined (mainly over cortical regions), whereas other VNS-induced CBF changes persisted (mainly over subcortical regions). Altered synaptic activities at sites of persisting VNS-induced CBF changes may reflect antiseizure actions. [source] Intra-articular stabilisation of the equine cricoarytenoid jointEQUINE VETERINARY JOURNAL, Issue 6 2008J. CHEETHAM Summary Reasons for performing study: The success of laryngoplasty is limited by abduction loss in the early post operative period. Objective: To determine the efficacy of polymethylmethacrylate (PMMA) in stabilising the cricoarytenoid joint (CAJ) and reducing the force on the laryngoplasty suture. Hypothesis: Injection into the cricoarytenoid joint resists the forces produced by physiological laryngeal air flows and pressures thereby reducing the force experienced by the laryngoplasty suture. Methods: Ten cadaver larynges were collected at necropsy and PMMA was injected into one CAJ at selected random. Each larynx was subjected to physiological conditions with with constant (static) or cycling (dynamic) flow. The specimens were tested sequentially in each of 4 conditions: 1) bilateral full abduction (Control 1); 2) transection of the suture on the side without PMMA; 3) bilateral abduction achieved by replacing the suture (Control 2); and 4) cutting the suture on the PMMA side. Tracheal pressure and flow and pressure in the flow chamber were recorded using pressure and flow transducers. The strain experienced by each suture during bilateral abduction (Controls 1 and 2) was measured. Statistical comparison of the 4 conditions was performed using a mixed effect model with Tukey's post hoc test for multiple comparisons. The strain gauge data were analysed by paired comparison of the regression slopes. Results: In the static and dynamic states, tracheal pressure increased and tracheal flow decreased when the suture on the non-cement side was cut (P<0.05). There was no significant difference in any outcome measure between PMMA injected into the CAJ and bilaterally abducted specimens (Controls 1 and 2) for either condition. The rate of increase in strain with increasing translaryngeal pressure was significantly less on the suture with PMMA placed in the CAJ (P = 0.03). Conclusions: These data provide strong evidence that injecting PMMA into the CAJ resists the collapsing effect of physiological airflows and pressures in vitro and reduces the force experienced by the laryngoplasty suture during maximal abduction. Potential relevance: Augmentation of prosthetic laryngoplasty with this technique may reduce arytenoid abduction loss in the early post operative period. [source] Polymorphisms located in the region containing BHMT and BHMT2 genes as maternal protective factors for orofacial cleftsEUROPEAN JOURNAL OF ORAL SCIENCES, Issue 4 2010Adrianna Mostowska Mostowska A, Hozyasz KK, Biedziak B, Misiak J, Jagodzinski PP. Polymorphisms located in the region containingBHMTandBHMT2genes as maternal protective factors for orofacial clefts. Eur J Oral Sci 2010; 118: 325,332. © 2010 The Authors. Journal compilation © 2010 Eur J Oral Sci Nonsyndromic cleft lip with or without cleft palate (NCL/P) is one of the most common craniofacial malformations; however, its aetiology is still unclear. Because the effects of maternal nutrition on fetal development are well known, we decided to pursue the question of whether polymorphic variants of genes encoding enzymes involved in choline metabolism might be associated with the maternal risk of having a baby with NCL/P. Analysis of 18 single nucleotide polymorphisms (SNPs) of betaine-homocysteine methyltransferase (BHMT), betaine-homocysteine methyltransferase-2 (BHMT2), choline dehydrogenase (CHDH), choline kinase (CHKA), dimethylglycine dehydrogenase (DMGDH), choline-phosphate cytidylyltransferase A (PCYT1A), and phosphatidylethanolamine N -methyltransferase (PEMT) provided evidence that polymorphisms located in the region containing BHMT and BHMT2 were protective factors against NCL/P affected pregnancies in our population. The strongest signal was found for the SNP located in the intronic sequence of BHMT2. Women carrying two copies of the rs625879 T allele had a significantly decreased risk of having offspring with orofacial clefts. These results were significant, even after correction for multiple comparisons. Moreover, the gene,gene interaction analysis revealed a significant epistatic interaction of BHMT2 (rs673752), PEMT (rs12325817), and PCYT1A (rs712012) with maternal NCL/P susceptibility. Altogether, our study identified a novel gene, the nucleotide variants of which were be associated with a decreased risk of having a baby with NCL/P. [source] Low-Dose Topiramate Versus Lamotrigine in Migraine Prophylaxis (The Lotolamp Study)HEADACHE, Issue 3 2007Praveen Gupta MD Objective.,To assess the efficacy and safety of topiramate and lamotrigine for prophylaxis in patients with frequent migraine as compared to each other and to placebo. Methods.,Sixty patients with frequent migraine (more than 4 attacks per month) from the headache clinic at a tertiary referral centre in India were randomized to receive 50 mg topiramate/lamotrigine or matching placebo for 1 month each in 2 divided doses in 4 phases in a crossover manner with a washout period of 7 days in between. Primary efficacy measure was responder rate (50% decrease in mean migraine frequency/intensity). Secondary efficacy measures included reduction in mean monthly frequency, intensity, duration, rescue medication use, migraine associated symptoms, and adverse events. Statistical analysis.,Analysis was on intention to treat basis. Data were analyzed as correlated data. Generalized estimation equation was used to compute overall mean standard deviation and 95% confidence intervals for each of the outcome variables. Bonferroni's correction done for multiple comparisons. P value of <.017 was taken as significant. Results.,Fifty-seven patients comprised the intent-to-treat population. Four patients withdrew from the study at various phases, none because of the side effects. Responder rate for frequency was significantly higher for topiramate versus placebo (63% vs 30%, P < .001), and versus lamotrigine (63% vs 46 %, P= .02). For intensity of headache also a responder rate of topiramate versus placebo (50% vs 10%, P < .001), and versus lamotrigine (50% vs 41%, P= .01) was observed. Topiramate showed statistically significant benefits (P < .017) in most of the secondary efficacy measures while lamotrigine was beneficial for reduction in headache frequency, and migraine associated symptoms. Adverse events were similar. Conclusion.,Low-dose topiramate is efficacious in migraine prophylaxis as compared to both placebo and lamotrigine. Lamotrigine in low doses might be beneficial for headache frequency; however, longer trials are required to establish its efficacy on the intensity and frequency of migraine. [source] Critical review of epidemiological studies of the association between smoking and non-Hodgkin's lymphomaHEMATOLOGICAL ONCOLOGY, Issue 2 2001Hedley G. Peach Abstract Smoking has been suggested to increase the risk of non-Hodgkin's lymphoma (NHL) but the results of epidemiological studies have been inconsistent. The aim of this work was to assess whether the findings of individual studies might have arisen by chance, bias or confounding and whether any associations found between smoking and NHL represent cause-and-effect. Reports of the association between smoking and NHL were identified from Medline. Confidence intervals on relative risks and odds ratios, use of multiple comparisons, and information on source, direction, actual existence and size of potential biases and confounding and features of any associations were abstracted. Four out of five cohort studies found no association between current smoking and NHL but three may have been biased against doing so. One found an association with follicular lymphoma but without a convincing exposure,risk gradient. The fifth found a strong association and an exposure,response gradient with ever smoking but excluded living cases from the end-point. Only one study found an association with past smoking which lacked features of causality. Eight out of 14 case,control studies found no association between current and/or past smoking and NHL but five may have been biased against doing so. Of six positive studies, three involved multiple comparisons, the association of one became non-significant after eliminating bias, four did not explore features of causality and one found an association only in heavy smokers, particularly under 45 years old. There are no grounds to reject the null hypothesis but associations should continue to be sought particularly in subgroups of smokers and with NHL subtypes. Copyright © 2001 John Wiley & Sons, Ltd. [source] Specific human leukocyte antigen class I and II alleles associated with hepatitis C virus viremia,,§HEPATOLOGY, Issue 5 2010Mark H. Kuniholm Studies of human leukocyte antigen (HLA) alleles and their relation with hepatitis C virus (HCV) viremia have had conflicting results. However, these studies have varied in size and methods, and few large studies assessed HLA class I alleles. Only one study conducted high-resolution class I genotyping. The current investigation therefore involved high-resolution HLA class I and II genotyping of a large multiracial cohort of U.S. women with a high prevalence of HCV and HIV. Our primary analyses evaluated associations between 12 HLA alleles identified through a critical review of the literature and HCV viremia in 758 HCV-seropositive women. Other alleles with >5% prevalence were also assessed; previously unreported associations were corrected for multiple comparisons. DRB1*0101 (prevalence ratio [PR] = 1.7; 95% confidence interval [CI] = 1.1,2.6), B*5701 (PR=2.0; 95% CI = 1.0,3.1), B*5703 (PR = 1.7; 95% CI = 1.0,2.5), and Cw*0102 (PR = 1.9; 95% CI = 1.0,3.0) were associated with the absence of HCV RNA (i.e., HCV clearance), whereas DRB1*0301 (PR = 0.4; 95% CI = 0.2,0.7) was associated with HCV RNA positivity. DQB1*0301 was also associated with the absence of HCV RNA but only among HIV-seronegative women (PR = 3.4; 95% CI = 1.2,11.8). Each of these associations was among those predicted. We additionally studied the relation of HLA alleles with HCV infection (serostatus) in women at high risk of HCV from injection drug use (N = 838), but no significant relationships were observed. Conclusion: HLA genotype influences the host capacity to clear HCV viremia. The specific HLA associations observed in the current study are unlikely to be due to chance because they were a priori hypothesized. (HEPATOLOGY 2010.) [source] Brain structure and obesityHUMAN BRAIN MAPPING, Issue 3 2010Cyrus A. Raji Abstract Obesity is associated with increased risk for cardiovascular health problems including diabetes, hypertension, and stroke. These cardiovascular afflictions increase risk for cognitive decline and dementia, but it is unknown whether these factors, specifically obesity and Type II diabetes, are associated with specific patterns of brain atrophy. We used tensor-based morphometry (TBM) to examine gray matter (GM) and white matter (WM) volume differences in 94 elderly subjects who remained cognitively normal for at least 5 years after their scan. Bivariate analyses with corrections for multiple comparisons strongly linked body mass index (BMI), fasting plasma insulin (FPI) levels, and Type II Diabetes Mellitus (DM2) with atrophy in frontal, temporal, and subcortical brain regions. A multiple regression model, also correcting for multiple comparisons, revealed that BMI was still negatively correlated with brain atrophy (FDR <5%), while DM2 and FPI were no longer associated with any volume differences. In an Analysis of Covariance (ANCOVA) model controlling for age, gender, and race, obese subjects with a high BMI (BMI > 30) showed atrophy in the frontal lobes, anterior cingulate gyrus, hippocampus, and thalamus compared with individuals with a normal BMI (18.5,25). Overweight subjects (BMI: 25,30) had atrophy in the basal ganglia and corona radiata of the WM. Overall brain volume did not differ between overweight and obese persons. Higher BMI was associated with lower brain volumes in overweight and obese elderly subjects. Obesity is therefore associated with detectable brain volume deficits in cognitively normal elderly subjects. Hum Brain Mapp, 2010. © 2009 Wiley-Liss, Inc. [source] ALE meta-analysis: Controlling the false discovery rate and performing statistical contrastsHUMAN BRAIN MAPPING, Issue 1 2005Angela R. Laird Abstract Activation likelihood estimation (ALE) has greatly advanced voxel-based meta-analysis research in the field of functional neuroimaging. We present two improvements to the ALE method. First, we evaluate the feasibility of two techniques for correcting for multiple comparisons: the single threshold test and a procedure that controls the false discovery rate (FDR). To test these techniques, foci from four different topics within the literature were analyzed: overt speech in stuttering subjects, the color-word Stroop task, picture-naming tasks, and painful stimulation. In addition, the performance of each thresholding method was tested on randomly generated foci. We found that the FDR method more effectively controls the rate of false positives in meta-analyses of small or large numbers of foci. Second, we propose a technique for making statistical comparisons of ALE meta-analyses and investigate its efficacy on different groups of foci divided by task or response type and random groups of similarly obtained foci. We then give an example of how comparisons of this sort may lead to advanced designs in future meta-analytic research. Hum Brain Mapp 25:155,164, 2005. © 2005 Wiley-Liss, Inc. [source] Multiple displacement amplification to create a long-lasting source of DNA for genetic studies,HUMAN MUTATION, Issue 7 2006Lovisa Lovmar Abstract In many situations there may not be sufficient DNA collected from patient or population cohorts to meet the requirements of genome-wide analysis of SNPs, genomic copy number polymorphisms, or acquired copy number alternations. When the amount of available DNA for genotype analysis is limited, high performance whole-genome amplification (WGA) represents a new development in genetic analysis. It is especially useful for analysis of DNA extracted from stored histology slides, tissue samples, buccal swabs, or blood stains collected on filter paper. The multiple displacement amplification (MDA) method, which relies on isothermal amplification using the DNA polymerase of the bacteriophage ,29, is a recently developed technique for high performance WGA. This review addresses new trends in the technical performance of MDA and its applications to genetic analyses. The main challenge of WGA methods is to obtain balanced and faithful replication of all chromosomal regions without the loss of or preferential amplification of any genomic loci or allele. In multiple comparisons to other WGA methods, MDA appears to be most reliable for genotyping, with the most favorable call rates, best genomic coverage, and lowest amplification bias. Hum Mutat 27(7), 603,614, 2006. © 2006 Wiley-Liss, Inc. [source] Differences in cognitive factors between "true drug" versus "placebo pattern" response to fluoxetine as defined by pattern analysisHUMAN PSYCHOPHARMACOLOGY: CLINICAL AND EXPERIMENTAL, Issue 4 2006Amy H. Farabaugh Abstract Objective Pattern analysis has identified two types of response patterns to antidepressants: "true drug" response (TDR) and "placebo pattern" response (PPR). This study examines the relationship between cognitive factors and TDR and PPR to fluoxetine. Methods We assessed 310 outpatients meeting DSM-III-R criteria for major depressive disorder (MDD) who were enrolled in an 8-week open trial of fluoxetine 20,mg/day. Response patterns were determined using the clinical global impressions-improvement (CGI-I). We administered the following self-rated scales to all patients at the baseline visit and at endpoint: perceived stress scale (PSS), cognitions questionnaire (CQ), Beck hopelessness scale (BHS) and dysfunctional attitudes scale (DAS). Results One hundred and thirty-four patients had TDR, 66 patients had PPR, and 110 patients were non-responders (NR). Demographic variables and severity of depression at baseline (HAMD-17) were not significantly different between the two response pattern groups. We compared cognitive factors before and after treatment across patients with TDR and PPR, and there were no significant differences at baseline in CQ, PSS, BHS, and DAS scores. At endpoint, outpatients with PPR had significantly lower scores on the PSS (p,<,0.001) compared to the patients with TDR, even after adjusting for multiple comparisons and severity of depression at endpoint. Conclusions Significant differences in cognitive/psychological factors, specifically lower post-treatment perceived stress, accompany "placebo" pattern of response to antidepressant treatment and differentiate it from "true drug" response pattern, as defined by pattern analysis. Copyright © 2006 John Wiley & Sons, Ltd. [source] Parents' feelings towards their adoptive and non-adoptive childrenINFANT AND CHILD DEVELOPMENT, Issue 3 2010Marshaun B. Glover Abstract In the current study, we examined parent gender differences in feelings (negativity and positivity) and perceptions of child behavioural and emotional problems in adoptive and biological parent,child dyads. In a sample of 85 families, we used a novel within-family adoption design in which one child was adopted and one child was a biological child of the couple, and tested whether the links between parent feelings and child maladjustment included effects of passive gene,environment correlation. Parents reported more negativity and less positivity as well as higher levels of externalizing behaviour for the adopted child compared to the non-adopted child, although effect sizes were small and no longer statistically significant after correcting for multiple comparisons. Fathers and mothers did not differ significantly in their reports of positive and negative feelings towards their children or in regard to child externalizing and internalizing behaviours. The correlations between parental negativity and positivity and child externalizing and internalizing were similar for fathers and mothers, and for adopted and non-adopted children. The findings suggest similar parent,child relationship processes for fathers and mothers, and that genetic transmission of behaviour from parent to child does not account for the association between parental warmth and hostility and child-adjustment problems. Copyright © 2009 John Wiley & Sons, Ltd. [source] The effect of irrigation time, root morphology and dentine thickness on tooth surface strain when using 5% sodium hypochlorite and 17% EDTAINTERNATIONAL ENDODONTIC JOURNAL, Issue 3 2010O. E. Sobhani Sobhani OE, Gulabivala K, Knowles JC, Ng Y-L. The effect of irrigation time, root morphology and dentine thickness on tooth surface strain when using 5% sodium hypochlorite and 17% EDTA. International Endodontic Journal, 43, 190,199, 2010. Abstract Aim, To evaluate the effect of irrigation with 5% sodium hypochlorite (NaOCl) alone and in conjunction with 17% ethylenediaminetetraacetic acid (EDTA) on tooth surface strain (TSS) and to analyse the influence of irrigation time, root morphology and dentine thickness. Methodology, Thirty-six single-rooted pre-molars with single canals had their crown and enamel reduced and root canals prepared using a standardized protocol. Teeth were grouped according to anatomical criteria and randomly distributed to experimental irrigation groups: (A) saline (negative control); (B) 5% NaOCl (positive control); (C) 5% NaOCl alternated with 17% EDTA. TSS was measured using electrical strain gauges bonded to the cervico-proximal part of the tooth. Teeth, mounted in clear acrylic resin placed in a universal testing machine, were subjected to nine consecutive 10-min irrigation periods followed by non-destructive occlusal loading to record TSS. Statistical analysis was carried out using two-way hierarchical anova and post hoc multiple comparisons. Results, Two groups showed an increase in TSS from the baseline (initial 10-min irrigation with saline). Group A showed a negligible reduction of 1.2% (343,339 ,,), which was not statistically significant (P = 0.7). Group B showed a highly significant (P = 0.001) increase in TSS by 53.7% (178,253 ,,), and group C showed a significant (P = 0.02) increase in TSS by 17.4% (163,192 ,,). The rate of change in TSS was significantly different between test groups. The length of the tooth (P = 0.04) as well as the mesio-distal (P = 0.05) width had significant effects on TSS. Conclusions, Irrigation with 5% with or without 17% EDTA increased TSS. The increase was significantly greater with 5% NaOCl alone than with 5% NaOCl alternated with 17% EDTA in contrast to previous findings with longer duration of irrigant exposure. Tooth length and mesio-distal root width significantly contributed to the increase in TSS. [source] Distance from file tip to the major apical foramen in relation to the numeric meter reading on the display of three different electronic apex locatorsINTERNATIONAL ENDODONTIC JOURNAL, Issue 12 2009R. A. Higa Abstract Aim, To establish and compare the relationship between the distance from the file tip to the apical foramen and the numeric meter reading on the display of three different electronic apex locators (EALs). Methodology, A total of 12 extracted intact, straight, single-rooted human teeth with complete roots were used. The actual root canal length (AL) was determined after access preparation. For the electronic measurements with each EAL, silicon stops were fixed with auto-polymerizing resin to size 15 K-files at AL and 0.5, 1, 2, 3, 4 mm short of AL. The data was analysed by two-way anova and Tukey's honestly significant difference (HSD) test for multiple comparisons amongst EALs. Additionally, one-way anova and Tukey's HSD test were carried out for multiple comparisons amongst the measurements of each EAL. Results, There was a statistically significant difference amongst all EALs in indicating the position of file tips in relation to the major foramen (P < 0.05). The correlation between the meter reading and the position of the file tip from the apical foramen was statistically significant in the three EALs. There were significant differences amongst the measurements at distances from 0 to 2 mm in Justy III. In Dentaport, significant differences were found from 0 to 1 mm. However, the E-Magic Finder showed significant differences from 0 to 0.5 mm. Conclusions, Justy III was more capable of displaying the intracanal position of the file tip from the major foramen in mm whilst advancing through the root canal during electronic measurements than the Dentaport and E-Magic Finder Deluxe. [source] Biocompatibility of various root canal filling materials ex vivoINTERNATIONAL ENDODONTIC JOURNAL, Issue 8 2008R. Scotti Abstract Aim, To evaluate the biocompatibility of a resin-based endodontic filler (RealSeal) using the indirect cytotoxicity test. Methodology, Human gingival fibroblasts were cultured ex vivo. Pellets of the materials to be tested were incubated for 24, 48, and 72 h at 37 °C under sterile conditions to obtain their eluates. The fibroblasts were exposed to either diluted (50%) or undiluted eluates for 24 h. A culture medium with foetal calf serum was added to the control wells. Cell viability was estimated by 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide method. The data concerning cell viability were statistically analyzed using one-way anova test and Bonferroni multiple comparisons test. Results, Eluates obtained after 24 h of incubation with the resin filler did not reduce cellular viability. An increase in cellular viability, as compared with control cells, was observed in the gutta-percha group. The undiluted eluate from the polyether material was cytotoxic, causing an 82 ± 4% decrease in cellular viability. Eluates obtained after 48 h of incubation with the resin filler increased cellular viability, whereas the polyether significantly reduced viability. Gutta-percha did not cause any detectable change. After 72 h of incubation the eluate of the resin filler caused an increase in cellular viability, as did gutta-percha, whereas polyether caused a significant decrease. Conclusions, RealSeal resin filler was nontoxic in this laboratory model. Further investigations are necessary to verify its usefulness in clinical applications. [source] Evaluation of canal filling after using two warm vertical gutta-percha compaction techniques in vivo: a preliminary studyINTERNATIONAL ENDODONTIC JOURNAL, Issue 7 2006M. Venturi Abstract Aim, To evaluate the quality of root canal filling when comparing two warm gutta-percha filling techniques in vivo. Methodology, Human teeth were randomly divided into two equal groups, with 30 canals each. The root canals were shaped by hand and ProFile 0.04 rotary instruments to size 20,40 at the end-point and then filled with gutta-percha cones and AH-Plus. In group A, a traditional warm vertical compaction technique was performed using the Touch'n Heat, and back-filling with the Obtura II. In group B, a modified warm vertical compaction technique was used: small amounts of gutta-percha were removed, and the remaining most apical 3 mm were compacted with a 1 mm movement; then thermomechanical back-filling was performed. The teeth were extracted, stored in dye, cleared, and the distance between the apex and apical limit of the filling, linear dye penetration, and voids were measured from the buccal, lingual, mesial and distal perspective. The homogeneity of variance and means was verified using Levene's test and t -test. anova and Dunnett post hoc test were used to establish the significance and to analyse the effects through multiple comparisons. Results, Compared with the specimens of group A, the specimens of group B exhibited less mean linear dye penetration (P < 0.05), smaller void length (P , 0.05) and maximal width (P , 0.05) when examined in all four views, and a more precise filling when viewed from the buccal aspect (P < 0.05). Conclusions, The modified warm vertical compaction technique with apical back-filling produced a more effective and precise three-dimensional filling. [source] What do we know about dementia?: a survey on knowledge about dementia in the general public of JapanINTERNATIONAL JOURNAL OF GERIATRIC PSYCHIATRY, Issue 4 2008Yumiko Arai Abstract Objective The importance of early detection of dementia has been highlighted in recent years by the medical and scientific community; however, delays often occur between the recognition of signs or symptoms and a decision by the patient or family to seek professional help. Such delays may be caused by a lack of knowledge about dementia among patients and family members. The aim of this study was to determine the understanding of dementia among the general public. Methods We conducted a survey in Japan that asked 11 questions regarding knowledge of ,general' information, ,symptoms', and ,biomedical' issues related to dementia. A quota sampling method was used to select 2,500 participants, 2,115 of who were eligible for the analyses. Results The average number of correct responses among females was significantly greater than that among the males. A multiple comparisons test demonstrated that middle-aged women were more knowledgeable than younger and older respondents. It was revealed that there was a lack of knowledge on biomedical aspects of dementia, i.e. cause, treatment, and prognosis along with a misunderstanding of dementia as senescence forgetfulness among the general public. Conclusions There appeared to be gaps in knowledge on dementia among the general public, which may prevent caregivers from planning upcoming social and financial challenges. Correct information needs to be given by health professionals and care staff. Educational initiatives planned for the general public could be useful, and should target those groups, men and non-middle aged women who have lower knowledge. Copyright © 2008 John Wiley & Sons, Ltd. [source] Stability and Adaptability of Cultivars in Non-balanced Yield Trials.JOURNAL OF AGRONOMY AND CROP SCIENCE, Issue 4 2002Comparison of Methods for Selecting, High Oleic' Sunflower hybrids for Grain Yield, Quality Abstract The best-yielding and most stable cultivars are identified by growing cultivars in different environments. The stability of grain-quality traits has been less thoroughly investigated than the stability of grain yield. High-oleic hybrids of sunflower have been available on the Argentinian seed market for several years. Research on the stability of these genotypes is scarce. The objectives of this work were (i) to compare, using three different methods, the stability and adaptability of high-oleic hybrids for grain yield and oil and oleic acid contents, and (ii) to explore the advantages and disadvantages of each method in selecting stable or adapted genotypes with high grain yield and high quality. Stability and adaptability analyses were performed on results for grain yields and oil and oleic acid contents of 35 high-oleic sunflower hybrids from 17 comparative yield trials conducted over 2 years in Argentina. Stability was estimated using two methods: Fisher's protected least significant difference (LSD) test, which compared hybrids with the best-yielding hybrid in each environment, and the test of relative yield (RY), which uses standard deviation as the measure of stability. Adaptability was estimated using Piepho's method of ,multiple comparisons with the best'. These three methods can be applied to unbalanced data. Piepho's method made little discrimination amongst the hybrids. The LSD and RY tests coincided in classifying the hybrids as stable and unstable in 85 % of cases for grain yield and 76 % for oil content. It is concluded that the most convenient method depends on characteristics of the experimental design and of variability of the evaluated trait. Results from the LSD test depend on the number of environments in which the cultivar is tested. The RY method is valuable for classifying some cultivars as high-yielding and stable, avoiding the problem of high-yielding environments biasing the general average. Use of both methods together could be effective for classifying hybrids when the number of environments is adequate. Zusammenfassung Stabilität und Adaptabilität von Kultivaren in nicht balancierten Ertragsversuchen. Methodenvergleich für Kornertrag und Qualität in ölsäurereichen-Sonnenblumen Höchste Erträge und Stabilität von Kultivaren werden durch Teste in verschiedenen Umwelten ermittelt. Stabilität der Qualitätseigenschaften des Korns sind bisher weniger untersucht worden als Stabilität des Kornertrages. Ölsäurereiche Hybriden von Sonnenblumen sind auf dem argentinischen Saatgutmarkt während der letzten Jahre angeboten worden. Untersuchungen zur Stabilität dieser Genotypen sind selten. Ziele dieser Arbeit waren es (i) drei unterschiedliche Methoden im Hinblick auf ihre Eignung für die Messung von Stabilität und Adaptabilität von ölsäurereichen Hybriden hinsichtlich Kornertrag, Öl- sowie Ölsäuregehalte zu vergleichen, und (ii) die Vorteile und Nachteile dieser Methoden zu analysieren, die eine Selektion stabiler und angepasster Genotypen mit hohem Kornertrag und hoher Qualität erlauben. Eine Analyse für Stabilität und Adaptabilität wurden aufgrund der Ergebnisse für Kornertrag, Öl- sowie Ölsäuregehalte von 35 Sonnenblumen, als Hybriden mit hohem Ölgehalt, auf der Grundlage von 17 vergleichenden Ertragsversuchen, die während zwei Jahren in Argentinien durchgeführt wurden, vorgenommen. Die Stabilität wurde unter Verwendung von zwei Methoden bestimmt: Der ,protected-LSD-Test' von Fisher, mit dem die Hybriden mit ertragshöchsten in jeder Umwelt verglichen werden; ferner der Test mit einem Vergleich des relativen Ertrags (RY), bei dem die Standardabweichung als Maß für die Stabilität verwendet wird; schließlich wurde die Adatabilität mit Piephos Methode eines multiplen Vergleichs mit der Besten durchgeführt. Die drei Methoden können nicht bancierten Daten angewendet werden. Piephos Methode ergab eine geringe Diskrimination für die Hybriden. LSD und RY stimmten bei einer Klassifizierung der Hybriden als stabile und nicht stabile in 85 % der Fälle hinsichtlich Kornertrag und 76 % für Ölgehalt überein. Es wird angenommen, dass geeignetere Methoden von den Eigenschaften der Experimentstruktur und der Variabilität der bewerteten Eigenschaften abhängen. Die Ergebnisse des LSD-Tests sind von der Anzahl der Umwelten abhängig, in denen die Kultivare getestet wurden. Die RY-Methode ist wertvoll, um einige Kultivare als hochertragreich und stabil zu klassifizieren, wobei der Einfluss hochertragreicher Umwelten zum Gesamtmittelwirt vermieden wird. Eine gemeinsame Anwendung der beiden Methoden könnte nützlich sein, um Hybriden zu klassifizieren, wenn eine geeignete Anzahl von Umwelten gegeben ist. [source] Feeding Practices of Dog and Cat Owners Reflect Attitudes Toward Pet FoodsJOURNAL OF ANIMAL PHYSIOLOGY AND NUTRITION, Issue 11-12 2005K. N. Willoughby The PET DINER study was a telephone survey conducted to better understand why pet owners make certain nutritional decisions for their pets. Both dog and cat owners were included, which allowed us to differentiate the way people feed pet cats vs. pet dogs and how that might reflect owners' attitudes about pet foods. Prospective survey respondents were selected from local telephone books using a randomized process. A total of 18,194 calls were made from the five study sites between May and August, 2004. 1074 people (6%) representing 619 dogs and 455 cats completed the survey. Detailed information about feeding practices was collected. Pet owners' perceptions were assessed based on agreement/disagreement with statements regarding pet foods and the pet food industry. The Mann,Whitney Rank Sum test was used to detect differences between dog and cat owners and the Kruskal,Wallis one-way analysis of variance on ranks was used to evaluate differences among pet owners based on both type of pet and feeding practices (,75% commercial vs. ,50% home-prepared diets). More cats than dogs ate commercial pet food as ,75% of their main diet (96% vs. 87%, respectively; p < 0.001), and more dogs than cats ate a home-prepared food as ,50% of their main diet (6% vs. 3%, respectively; p < 0.009). For five of the statements, a difference in the attitudes of cat vs. dog owners was detected (p < 0.05). In general, this reflected more positive attitudes regarding commercial foods and less positive attitudes regarding home-prepared foods on the part of cat vs. dog owners. Analysis based on both type of pet and feeding practices identified significant differences among groups for 18/26 statements. However, when the Dunn's Method for pairwise multiple comparisons was applied, significant differences were due to feeding practices rather than type of pet for 17/18 statements. Only differences in attitudes about the statement ,raw bones can be safely fed to pets' remained significant for cat vs. dog owners feeding commercial foods. In conclusion, more cat owners than dog owners feed ,75% commercial foods to their pets and this is reflected in different attitudes about the nutritional soundness of commercial pet foods. [source] The distribution,abundance (density) relationship: its form and causes in a tropical mammal order, PrimatesJOURNAL OF BIOGEOGRAPHY, Issue 4 2005A. H. Harcourt Abstract Aim, Across a wide variety of organisms, taxa with high local densities (abundance) have large geographical ranges (distributions). We use primatology's detailed knowledge of its taxon to investigate the form and causes of the relationship in, unusually for macroecological analysis, a tropical taxon. Location, Africa, Central and South America, Asia, Madagascar. Methods, To investigate the form of the density,range relationship, we regressed local density on geographical range size, and also on female body mass, because in the Primates, density correlates strongly with mass. To investigate the biological causes of the relationship, we related (1) abundance (density × range size) and (2) residuals from the density,range regression lines to various measures of (i) resource use, (ii) reproductive rate and (iii) potential specialization. All data are from the literature. Analyses were done at the level of species (n = 140), genera (n = 60) and families/subfamilies (n = 17). We present various levels of results, including for all data, after omission of outlier data, after correction for phylogenetic dependence, and after Bonferroni correction of probabilities for multiple comparisons. Results, Regarding the form of the relationship, Madagascar primates are clear outliers (high densities in small ranges). Among the remaining three realms, the relation of density to range is weak or non-existent at the level of species and genera. However, it is strong, tight and linear at the level of families/subfamilies (r2 = 0.6, F1,10 = 19, P < 0.01). Although among primates, density is very significantly related to mass, at no taxonomic level is range size related to body mass. Consequently, removing the effects of mass makes little to no difference to density,range results. Regarding the biology of the relationship, only traits indicative of specialization are associated with abundance (meaning numbers): rare taxa are more specialized than are abundant taxa. The association is largely via range size, not density. Across families, no traits correlate significantly with the density,range relationship, nor with deviations from it, despite the strength of the relationship at this taxonomic level. Main conclusions, We suggest that in macroecology, analysis at taxonomic levels deeper than that of the relatively ephemeral species can be appropriate. We argue that the several purely methodological explanations for the positive density,range size relationship in primates can be rejected. Of the various biological hypotheses, those having to do with specialization,generalization seem the only applicable ones. The fact that the relationship is entirely via range size, not via density, means that while we might have a biology of range size, we do not yet have one of the density,geographical range relationship. It is probably time to search for multivariate explanations, rather than univariate ones. However, we can for the first time, for at least primates, suggest that any association of abundance or range size with specialization is via the number of different subtaxa, not the average degree of specialization of each subtaxon. The implication for conservation is obvious. [source] Saliva concentrations of RANKL and osteoprotegerin in smoker versus non-smoker chronic periodontitis patientsJOURNAL OF CLINICAL PERIODONTOLOGY, Issue 10 2008Nurcan Buduneli Abstract Objectives: To compare the salivary receptor activator of NF- ,B ligand (RANKL) and osteoprotegerin (OPG) concentrations in smokers versus non-smokers with chronic periodontitis. Material and Methods: Whole saliva samples were obtained from 67 untreated chronic periodontitis patients, of whom 34 were smokers, and from 44 maintenance patients, of whom 22 were smokers. Full-mouth clinical periodontal measurements were recorded. Saliva cotinine, sRANKL and OPG concentrations were determined by ELISA. Statistical analysis was performed using the Mann,Whitney U test, Bonferroni's correction for multiple comparisons and Spearman's correlations. Results: Untreated smokers exhibited significantly higher values of clinical periodontal recordings than untreated non-smokers (all p<0.05). Salivary cotinine level correlated with clinical attachment level (p=0.023). Smoker versus non-smoker maintenance groups showed no significant differences in clinical parameters. There were significant differences in sRANKL and OPG concentrations between untreated and maintenance groups (all p<0.01). Salivary OPG concentration was significantly lower (all p<0.01) and the sRANKL/OPG ratio was higher (all p<0.01) in smokers than in non-smokers. OPG concentration correlated positively with probing depth, clinical attachment level and bleeding on probing (all p<0.005) and negatively with pack-year, and cotinine level (p<0.05). Conclusion: Salivary RANKL and OPG concentrations are suggested to be affected by smoking as not only the untreated but also the treated smokers exhibited higher RANKL and lower OPG concentrations than non-smokers. [source] | |||||||||||||||||||||||||||||||||||||||||||