Group Differences In Variables Research Articles

MRI Statistical region of interest best differentiates impaired from non‐impaired in the Study of Latinos‐Investigation of Neurocognitive Aging‐MRI (SOL‐INCA‐MRI)

AbstractBackgroundWe developed a statistical region of interest (sROI) of gray matter (GM) for which cortical thickness (CT) significantly differed in a “training set” of 100 cognitively normal and 100 individuals with incident dementia in the Framingham Heart Study. sROI significantly predicts incident cognitive impairment and dementia in both FHS and the highly diverse UC Davis Alzheimer’s disease longitudinal cohort. Here we describe a similar analysis of participants of Study of Latinos‐Investigation of Neurocognitive Aging‐MRI (SOL‐INCA‐MRI).MethodsHispanics/Latinos (n=6,377 ages 50‐86) were enrolled in the Study of Latinos ‐ Investigation of Neurocognitive Aging (SOL‐INCA) of which 1,143 also participated in SOL‐INCA‐MRI ancillary study. Cognitive impairment (CI) was defined as any cognitive domain score falling below (<‐1.0 SD) the SOL‐INCA robust internal normative mean and significant cognitive decline (‐0.055 SD/yr), self‐reported cognitive decline and no or minimal functional impairment over 7 years. Participants with dementia were excluded.MRI CT was computed by the DiReCT method. sROI was derived from statistically significant (via 1,000 non‐parametric permutations) clusters of GM voxels having CT group difference t > 2 over the training set (Fig. 1). Extents of sROI overlap with standard atlas GM regions appear in Table 3.Group differences in variables were assessed by t‐test. Logistic regression assessed the impact on cognitive status of MRI factors: total brain, hippocampal, white matter hyperintensities (WMH), sROI volumes and infarction occurrence, controlling for age, sex, education, and background.ResultsThe cohort was 64.4 + 7 years of age, 69% female. Nearly 60% with high school or less education, and 21% CI. Table 1 summarizes demographic and MRI measures for CI and cognitively normal (CN). CI individuals were older, had less education, smaller brains, and greater amounts of WMH. Table 2 summarizes results of logistic regression. Education and sROI mean CT were the only significant predictors of cognitive status.ConclusionCortical thickness within the sROI was strongly associated with cognitive status, even when other commonly used MRI measures were not. sROI may therefore be a sensitive indicator of incipient CI within SOL‐INCA‐MRI where more traditional measures of Alzheimer’s pathology and vascular disease appear insensitive.

Cooperative co-evolutionary algorithm for multi-objective optimization problems with changing decision variables

Multi-objective optimization problems (MOPs) with changing decision variables exist in the actual industrial production and daily life, which have changing Pareto sets and complex relations among decision variables and are difficult to solve. In this study, we present a cooperative co-evolutionary algorithm by dynamically grouping decision variables to effectively tackle MOPs with changing decision variables. In the presented algorithm, decision variables are grouped into a series of groups using maximum entropic epistasis (MEE) at first, with decision variables in different groups owning a weak dependency. Subsequently, a sub-population is generated to solve decision variables in each group with an existing multi-objective evolutionary algorithm (MOEA). Further, a complete solution including all the decision variables is achieved through the cooperation among sub-populations. Finally, when a decision variable is added or deleted from the existing problem, the grouping of decision variables is dynamically adjusted based on the correlation between the changed decision variable and existing groups. To verify the performance of the developed method, the presented method is compared with five popular methods by tackling eight benchmark optimization problems. The experimental results reveal that the presented method is superior in terms of diversity, convergence, and spread of solutions on most benchmark optimization problems.

Effect of Different Habitats Conditions on Citrullus colocynthis (L.) Schrad. Growing Naturally in Egypt and Kingdom of Saudi Arabia

Harsh environmental conditions are major factors limiting plants production and development, including Citrullus colocynthis L. (C. colocynthis). The present investigation provides an analysis of soil properties and plant compounds of C. colocynthis in Wadi Hebran, Saint Katherine, South Sinai, Egypt and Wadi Al-Akhder, Tabuk Province, KSA at dry and wet seasons, and focuses on the relationship between the environmental factors and phytochemical compounds using principal component analysis (PCA). According to ANOVA, the experimental factors (locations, depths, seasons and their interactions significantly influenced the physico-chemical properties of soil and chemicals present in C. colocynthis (P < 0.05 or 0.01). Wadi Hebran at both seasons significantly promoted most mechanical and chemical properties in soil and most chemical compositions in C. colocynthis compared with Wadi Al-Akhder. While the significantly positive highest impact on photosynthetic pigments contents was found in Wadi Al-Akhder at both seasons. The dry season in the two locations significantly increased the total carotenoids, Chl.a/b, total pigment, P %, total carbohydrate, proline, catalase enzyme, peroxidase enzyme, ascorbic acid and malondiadehyde compared to the wet season. Based on PCA analysis, the first two PCs explain more than 84% of the total variance in the original variables and mainly distinguished the soil and plant variables in different groups during each location or between the two locations at both seasons. The first PC showed the highest positive correlation with some soil variables (EC, K+, and Cl-) and plant variables (P, total carbohydrate, proline, catalase enzyme, peroxidase enzyme and malondiadehyde). While the second PC exhibited a highly positively correlated with Ca2+, S- and water content in soil and with Chl.b, K+, Ca2+, N, water content, crude protein, crude fiber, total ash and superoxide enzyme in C. colocynthis plants. Positive correlations among most soil and plant variables were found, but they differed in their degree and consistency in quantity. PCA application indicated that the above soil variables are related closely to the above plant variables of C. colocynthis in the two locations. The results of PCA could be useful and used as a suitable method for studying the stresses tolerance mechanisms of plants under hard environmental conditions.

Morphological Study of Foetal Thymus: A Cross-sectional Study

Introduction: Thymus is a primary central lymphoid organ and a key regulator of the immune system. It develops from the ventral aspect of the 3rd pharyngeal pouch and also gets contribution from the 4th pharyngeal pouch. It migrates caudally into thorax due to its attachment to the pericardium and the aortic sac. Aim: To determine the morphometry of thymus gland in human foetuses. Materials and Methods: It was a cross-sectional study which included 33 human foetuses available in the Department of Anatomy, Sri Aurobindo Medical College and Postgraduate Institute (SAMC and PGI), Indore, Madhya Pradesh, India, over a period of three years. The samples were divided into four groups as per the Gestational Age (GA), (13-16, 17-20, 21-24, 25-29 weeks), based on measuring the Crown Rump (CR) length. After making a midline incision extending from the neck to the chest wall, the thoracic and cervical part of the thymus were displayed and its height and width were measured. For statistical analysis Statistical Package for the Social Sciences (SPSS), version 20.0 was used to analyse the association between the present findings in the given study groups. Results: Cervical extension showed great variability in different groups. It was either bilateral (16), unilateral (9) or even absent (8) in some cases. Cervical extension showed variable appearances like, coiled, lobulated or cord-like. In four cases, it reached upto the lower pole of thyroid. The shape of the thoracic part of the thymus was either vertically elongated or curved, lobulated or retort shape. Conclusion: The present findings of morphometry of foetal thymus are important for radiologists to differentiate thymus from other mediastinal structures and for surgeons during thymectomy. With increasing foetal age, there is regression in the cervical part of the thymus.

Use of Effect Size Measures along with p-Value in Scientific Publications


 Background: To describe various measures for estimation of effect size, how it can be calculated and the scenarios in which each measures of effect size can be applied. 
 Methods: The researchers can display the effect size measures in research articles which evaluate the difference between the means of continuous variables in different groups or the difference in proportions of outcomes in different groups of individuals. When p-value alone is displayed in a research article, without mentioning the effect size, reader may not get the correct pictures regarding the effect or role of independent variable on the outcome variable. 
 Results: Effect size is a statistical concept that measures the actual difference between the groups or the strength of the relationship between two variables on a numeric scale. 
 Conclusion: Effect size measures in scientific publications can communicate the actual difference between groups or the estimate of association between the variables, not just if the association or difference is statistically significant. The researchers can make their findings more interpretable, by displaying a suitable measure of effect size. Effect size measure can help the researchers to do meta-analysis by combining the data from multiple research articles.

Maximum Voluntary Molar and Incisor Biting Force and Morphological Variables in Subjects With Different Vertical Skeletal Patterns

Objective: To estimate the maximum voluntary molar biting force (MBF) and incisor biting force (IBF) and their relationship to morphological variables in subjects with different vertical skeletal patterns. Materials and Methods: Maximum voluntary MBF, IBF, and morphological variables were recorded in 120 subjects (60 males and 60 females) with skeletal class I pattern in the age range of 14 to 24 years. All subjects were divided into 3 groups: Normodivergent, hypodivergent, and hyperdivergent, according to the maxillomandibular plane angle and Jarabak ratio. Bite force measurements were undertaken using a custom-made portable digital gnathodynamometer on the left and the right sides of the jaw in the molar and incisor regions during maximal clenching. Statistical analysis was performed using independent t-test, chi-square test, and ANOVA test using SPSS version 22.0.0.0 software. Results: MBF and IBF are influenced by gender with higher values obtained for male subjects in all groups in the following order: hypodivergent > normodivergent > hyperdivergent. No significant changes were seen with morphological variables in different groups. Conclusion: Molar and incisor biting forces are highest in hypodivergent subjects and least in hyperdivergent subjects as a reflection of jaw morphology and muscular efficiency. In all groups, males exhibit higher force values than females, underlining a strong gender influence on biting force and facial pattern.

Distribution neglect in performance evaluations

Five empirical studies, including both laboratory experiments and an archival investigation, provide evidence that decision makers often fail to consider variability and skew when making judgments about performance. We term this distribution neglect. Participants’ spontaneous explanations for group differences in elite achievement overwhelmingly invoked mean differences rather than group differences in variability, even when the complete distribution and summary statistics were provided (Study 1). A longitudinal examination indicates that NBA teams overweight average performance and underweight consistency of performance when deciding players’ contracts (Study 2), providing evidence that neglecting variance information leads to suboptimal judgments. In a manufacturing scenario involving monitoring assembly line workers, participants were more accurate at identifying top (high mean) performers than consistent (low variability) performers (Study 3). In a hiring simulation, decision makers were more likely to factor in variance when performance data was presented visually as a histogram (Study 4). Finally, participants’ spontaneous explanations for others’ self-assessments of ability assumed egocentric bias, when a skewed performance distribution was also a plausible contributor (Study 5). Individual differences (need for cognition) and task differences (such as style of information display) were associated with increased distribution-based reasoning in multiple studies, suggesting potential boundary conditions for further investigation. Organizational implications, and additional potential remedies for distribution neglect, are discussed.

Examining group differences in between-participant variability in non-native speech sound learning

Many studies on non-native speech sound learning report a large amount of between-participant variability. This variability allows us to ask interesting questions about non-native speech sound learning, such as whether certain training paradigms give rise to more or less between-participant variability. This study presents a reanalysis of Fuhrmeister and Myers (Attention, Perception, and Psychophysics, 82(4), 2049-2065, 2020) and tests whether different types of phonetic training lead to group differences in between-participant variability. The original study trained participants on a non-native speech sound contrast in two different phonological (vowel) contexts and tested for differences in means between a group that received blocked training (one vowel context at a time) and interleaved training (vowel contexts were randomized). No statistically significant differences in means were found between the two groups in the original study on a discrimination test (a same-different judgment). However, the current reanalysis tested group differences in between-participant variability and found greater variability in the blocked training group immediately after training because this group had a larger proportion of participants with higher-than-average scores. After a period of offline consolidation, this group difference in variability decreased substantially. This suggests that the type and difficulty of phonetic training (blocked vs. interleaved) may initially give rise to differences in between-participant variability, but offline consolidation may attenuate that variability and have an equalizing effect across participants. This reanalysis supports the view that examining between-participant variability in addition to means when analyzing data can give us a more complete picture of the effects being tested.

Adults with knee osteoarthritis use different coordinative strategies to transition from swing to stance compared to young asymptomatic adults.

Neuromuscular changes that occur with aging or joint pathology likely alter the coordinative strategies that adults use to walk and to recover from perturbations during gait. Differences in coordination patterns or in how coordination changes in response to a challenge may provide insight into neuromuscular targets for falls prevention interventions. Do young asymptomatic adults, older asymptomatic adults, and older adults with knee OA alter their lower extremity segment coordination differently in response to an increase in walking speed?. We captured lower extremity kinematics using inertial measurement units as 29 participants (10 young, 10 older, 9 older with knee osteoarthritis) walked on a treadmill at self-selected preferred and faster speeds. We calculated lower extremity segment coordination and coordination variability using vector coding. We compared coordination and its variability among groups and speeds. There were no significant interactions between group and speed. Overall group or speed differences in coordination or variability occurred mostly during terminal swing or early stance. Coordination patterns differed between young adults and adults with knee osteoarthritis in all segment couples during terminal swing and at the foot vs. shank during early stance. During these same gait cycle phases for the foot vs. shank and shank vs. thigh segment couples, coordination patterns shifted towards those of young adults when participants walked faster. Where coordination variability differed by group or speed, it was lower in the young adults than in the older adults with or without knee osteoarthritis and at faster walking speed. Our results identified that older adults with knee osteoarthritis have a different strategy for transitioning from swing to stance compared to young adults, especially at distal limb segments. These results may help target fall prevention interventions to specific gait cycle phases or strategies.

Prevalence of risk factors for noncommunicable diseases among adult population in an urban slum of Pune, India

Introduction: India is experiencing health transition with a rising burden of noncommunicable diseases (NCDs). There is a need to study risk factors of NCDs among poor and underprivileged section of the society. Methodology: A cross-sectional study was done among adults in an urban slum in Pune using the World Health Organization's STEP wise approach to surveillance (STEPS). Two hundred individuals selected by simple random sampling participated in this study. Information regarding dietary habits, physical activity, and tobacco and alcohol consumption was obtained. Physical measurements of height, weight, waist and hip circumference, and blood pressure were also done. Nominal and numerical variables in different groups were compared by Fisher's exact test and Student's t-test, respectively. Logistic regression was used to determine the association of various factors with high blood pressure. Results: Tobacco and alcohol consumption was observed in 22.5% (95% confidence interval [CI]: 16.9%–28.9%) and 11.5% (95% CI: 7.4%–16.8%) of individuals, which was significantly higher among males. 40.0% (95% CI: 33.2%–47.1%) of participants were doing less than recommended physical activity. 47% (95% CI: 40.0%–54.2%) of individuals were overweight or obese. The prevalence of high blood pressure was found to be 43.9% (95% CI: 36.6%–51.3%). Significant positive correlation was observed among different anthropometric variables. Multivariable logistic regression showed that there was significant positive association of high blood pressure with age (adjusted odds ratio [aOR] = 1.05 [95% CI: 1.02–1.08]) and waist hip ratio (aOR = 1.45 [95% CI: 1.01–2.09]). Conclusions: There is a high prevalence of risk factors for NCDs among residents of urban slum. Behavior change communication is required for adoption of healthy lifestyle and prevents NCDs in urban slums.

Prevalencia del consumo de bebidas energéticas, motivación y factores asociados en alumnos de medicina: estudio transversal

Introducción: Los objetivos de este estudio son: descubrir el nivel y la intensidad del consumo de bebidas energéticas (BE), conocer la motivación y analizar los factores asociados al consumo en una muestra de estudiantes de Medicina de 1º y 2º curso. Material y métodos: Estudio observacional y transversal. Se incluyeron todos los alumnos de 1º y 2º curso de Medicina en la Universidad Europea de Madrid en los cursos 2017-2018 y 2018-19. Se elaboró una encuesta, no validada, basada en otras tres publicadas (Universidad de West Indies, la de Palermo e Informe EFSA) con 20 ítems: 7 preguntas sobre datos sociodemográficos y de estilo de vida y 13 preguntas sobre conocimiento y hábitos de consumo de BE. Los alumnos rellenaron la encuesta de forma voluntaria, anónima y autoadministrada. Se realizó una estadística descriptica y para la comparación de variables cualitativas en diferentes grupos se utilizó la prueba χ2 o el test exacto de Fisher en caso necesario. Resultados: Respondieron a la encuesta el 80% (353 alumnos de 440) siendo la mayoría mujeres (70%). 115 alumnos (32,6% de la muestra) señalaron que consumían al menos una lata al mes (consumidores). De ellos, el 66% (77 alumnos), ingería menos de una a la semana, el 22,4% (26) entre una y dos por semana. Las mezclaban con bebidas alcohólicas en el 53% de los casos. Las tres justificaciones más importantes para su consumo fueron: estar despierto para estudiar, el sabor y mantenerse despierto para actividades lúdicas. El sexo masculino y ser fumador se asoció con una mayor frecuencia de consumo. Conclusiones: Los alumnos de 1º y 2º de Medicina indicaron consumir bebidas energéticas con frecuencia, en especial los varones. Los motivos más importantes para el consumo fueron aumentar la concentración para estudiar, el sabor y para mantenerse más tiempo despierto de fiesta. El consumo de fin de semana se asoció al consumo de BE mezcladas con alcohol.

Effects of different salt concentrations and vacuum packaging on the shelf-stability of Russian sturgeon (Acipenser gueldenstaedti) stored at 4 °C

The effects of different salt concentrations and vacuum packaging on the quality and microbiota dynamics of Russian sturgeon fillets stored at 4 °C were evaluated over a 12-day storage in this study. During refrigerated storage, The combination of 6% (w/v) brine salting for 2 h and vacuum packaging exerted beneficial effects on the quality of Russian sturgeon fillets, as demonstrated by affecting the sensory acceptability, retarding the production of total volatile basic nitrogen (TVB-N), delaying lipid oxidation measured by thiobarbituric acid reactive substances (TBARS) value. Meanwhile, the morphological changes in the muscle at different salt concentrations were observed by Scanning Electron Microscopy (SEM). Based on total viable counts (TVC), there was a lag phase of 3 days for the shelf life of 6% salting samples and vacuum packaging samples compared with the control. Moreover, the microbiota variability in different groups was investigated. The combination of 6% salting and vacuum packaging could effectively delay the growth of Pseudomonas which was the predominant microbiota in Russian sturgeon fillets during the final period of storage. The results indicated that 6% salting combined with vacuum packaging extended the shelf-life of Russian sturgeon fillets during storage, which was mainly due to their inhibition on dominant spoilage bacteria.

Detecting which variables alter component interpretation across multiple groups: A resampling-based method.

In psychology, many studies measure the same variables in different groups. In the case of a large number of variables when a strong a priori idea about the underlying latent construct is lacking, researchers often start by reducing the variables to a few principal components in an exploratory way. Herewith, one often wants to evaluate whether the components represent the same construct in the different groups. To this end, it makes sense to remove outlying variables that have significantly different loadings on the extracted components across the groups, hampering equivalent interpretations of the components. Moreover, identifying such outlying variables is important when testing theories about which variables behave similarly or differently across groups. In this article, we first scrutinize the lower bound congruence method (LBCM; De Roover, Timmerman, & Ceulemans in Behavior Research Methods, 49, 216-229, 2017), which was recently proposed for solving the outlying-variable detection problem. LBCM investigates how Tucker's congruence between the loadings of the obtained cluster-loading matrices improves when specific variables are discarded. We show that LBCM has the tendency to output outlying variables that either are false positives or concern very small, and thus practically insignificant, loading differences. To address this issue, we present a new heuristic: the lower and resampled upper bound congruence method (LRUBCM). This method uses a resampling technique to obtain a sampling distribution for the congruence coefficient, under the hypothesis that no outlying variable is present. In a simulation study, we show that LRUBCM outperforms LBCM. Finally, we illustrate the use of the method by means of empirical data.

Group SLOPE – Adaptive Selection of Groups of Predictors

ABSTRACTSorted L-One Penalized Estimation (SLOPE; Bogdan et al. 2013, 2015) is a relatively new convex optimization procedure, which allows for adaptive selection of regressors under sparse high-dimensional designs. Here, we extend the idea of SLOPE to deal with the situation when one aims at selecting whole groups of explanatory variables instead of single regressors. Such groups can be formed by clustering strongly correlated predictors or groups of dummy variables corresponding to different levels of the same qualitative predictor. We formulate the respective convex optimization problem, group SLOPE (gSLOPE), and propose an efficient algorithm for its solution. We also define a notion of the group false discovery rate (gFDR) and provide a choice of the sequence of tuning parameters for gSLOPE so that gFDR is provably controlled at a prespecified level if the groups of variables are orthogonal to each other. Moreover, we prove that the resulting procedure adapts to unknown sparsity and is asymptotically minimax with respect to the estimation of the proportions of variance of the response variable explained by regressors from different groups. We also provide a method for the choice of the regularizing sequence when variables in different groups are not orthogonal but statistically independent and illustrate its good properties with computer simulations. Finally, we illustrate the advantages of gSLOPE in the context of Genome Wide Association Studies. R package grpSLOPE with an implementation of our method is available on The Comprehensive R Archive Network.

Abstract 431: Sex Differences in Manifestation of Subclinical Coronary Atherosclerosis: Analysis of Lipoprotein Sub-Fractions in Healthy but High Risk Individuals

Background: Lipoproteins-rich triglycerides are associated with markers of coronary atherosclerosis such as coronary artery calcification (CAC) in young high-risk population. This study examines differences between sexes associated with lipoprotein sub-fractions and atherosclerosis. Methods: The study presents analysis from baseline data of a randomized trial of employees of Baptist Health South Florida with metabolic syndrome or diabetes. Participants completed lipoprotein sub-fraction analysis at baseline using ion mobility technique. Subjects above 35 years had a CAC test completed. We tested for differences between correlational matrices of the original variables. The same analysis was repeated for sets of 3 principal components (PC) that were computed for the combination of all lipoprotein subclasses. Results: The study population (N=170) was largely female (128) with a mean age of 58 years. Three PCs accounted for 83% variation in the sample. Distribution of atherosclerostic PC2 by sex was entirely different between sexes (Wishart test p=.004). In addition, a significant Jennrich’s test (p < .0045) implied that the inter-correlations among all dependent variables for different groups were dissimilar; with the finding of significant angles between PC components by sex. PC2, with main contributions from VLDL particles, was in the positive direction; however PC3 with large LDL particles was in the negative direction. Atherogenic lipoprotein profiles were significant only for males, with PC keeping their independent predictability. Conclusion: In a relatively young high-risk population, there were sex-specific differences in lipoprotein sub-fractions profiles that are associated with increased risk of atherosclerosis. The relationship was much weaker for males compared to females (see graph). These findings points towards a possible sex-linked lipoprotein sub-fraction association with the atherosclerosis pathogenesis.

Dynamical signatures of isometric force control as a function of age, expertise, and task constraints.

From the conceptual and methodological framework of the dynamical systems approach, force control results from complex interactions of various subsystems yielding observable behavioral fluctuations, which comprise both deterministic (predictable) and stochastic (noise-like) dynamical components. Here, we investigated these components contributing to the observed variability in force control in groups of participants differing in age and expertise level. To this aim, young (18-25 yr) as well as late middle-aged (55-65 yr) novices and experts (precision mechanics) performed a force maintenance and a force modulation task. Results showed that whereas the amplitude of force variability did not differ across groups in the maintenance tasks, in the modulation task it was higher for late middle-aged novices than for experts and higher for both these groups than for young participants. Within both tasks and for all groups, stochastic fluctuations were lowest where the deterministic influence was smallest. However, although all groups showed similar dynamics underlying force control in the maintenance task, a group effect was found for deterministic and stochastic fluctuations in the modulation task. The latter findings imply that both components were involved in the observed group differences in the variability of force fluctuations in the modulation task. These findings suggest that between groups the general characteristics of the dynamics do not differ in either task and that force control is more affected by age than by expertise. However, expertise seems to counteract some of the age effects.NEW & NOTEWORTHY Stochastic and deterministic dynamical components contribute to force production. Dynamical signatures differ between force maintenance and cyclic force modulation tasks but hardly between age and expertise groups. Differences in both stochastic and deterministic components are associated with group differences in behavioral variability, and observed behavioral variability is more strongly task dependent than person dependent.

Immunohistochemical Evaluation of Angiogenesis Related Markers in Pyogenic Granuloma of Gingiva

Pyogenic granuloma is a common non-neoplastic connective tissue proliferation. ICAM-1 and VCAM-1 are vascular adhesion molecules and CD34 is a marker for evaluation of angiogenesis. The purpose of this study was to compare the immunohistochemical expression of ICAM-1, VCAM-1 and CD34 in oral pyogenic granuloma and normal gingiva. This study was performed on thirty five formalin-fixed, paraffin embedded samples of gingival pyogenic granuloma. Also we used thirty five paraffined blocks of normal gingiva as control group which were taken from crown lengthening surgery. We employed immunohistochemistry staining for our prepared microscopic slides using monoclonal mouse anti-human antibodies against ICAM-1 (CD54), VCAM-1 (CD106) and CD34. Slides were examined under light microscope and then the mean amount of stained vessels also known as microvascular density (MVD) in highly vascularized areas (hot spots) was measured. Paired t-test and repeated measures ANOVA were used to compare the difference between quantitative variables and Chi-square test for qualitative variables in different groups. Pearson correlation coefficient was used to compare relations between quantitative variables. P<0.05 was considered significant. The mean of MVD for ICAM-1, VCAM-1 and CD34 was significantly higher in pyogenic granuloma than normal gingiva (p<0.001 and p<0.001 and p<0.001, respectively). Expression of CD34 in pyogenic granuloma was significantly higher than ICAM-1 and VCAM-1 (P<0.001). Besides, expression of ICAM-1 in normal gingiva, was significantly lower than two other markers (p<0.001). Regarding the results, it seems that ICAM-1, VCAM-1 and CD34 are useful biomarkers in evaluation of vascular and inflammatory lesions such as gingival pyogenic granuloma and the results indicate the role of these biomarkers in pathogenesis of oral pyogenic granuloma.

PP.03.27

Objective: There is a growing evidence of the prognostic significance of visit-to-visit BP variability in different groups of patients. Several studies evaluated prognostic significance of 24-h BPV in patients with heart failure. The aim of the study was to evaluate prognostic significance of visit-to-visit BPV in patients with stable HF and reduced ejection fraction. Design and method: Retrospective analysis included 100 pts (80 men, age 64,4 ± 9,3yrs, BP 127,6 ± 15,1/77,9 ± 8,3mmHg, HR 72,3 ± 10,4 bpm) with stable II-III NYHA class HF with EF <40% (mean 32,3 ± 4,3%). Median of baseline NT-proBNP was 1200 pmol/l (402,0–20524 pmol/l). Patients received stable standard therapy for HF with ACE inhibitors, beta-blockers, verospirone and furosemide. BP was measured with a validated oscillometric device. Visit-to-visit BPV was calculated as SD for 5 visits during 18 months. The endpoints included death, myocardial infarction (MI), stroke, hospitalization for HF. Results: At the end of the study BP was 123,6 ± 12,6/74,8 ± 8,9mmHg, HR 69,3 ± 9,1 bpm. Visit-to-visit SBPV varied from 2,3 to 20,0 mmHg, DBPV from 1,5 to 13,0 mmHg. 47 endpoints in 37 patients were registered (21 deaths, 17 hospitalizations for HF, 6 MI and 3 strokes). There was no significant difference between groups with and without endpoints in age, gender, history of MI, baseline BP, severity of HF, EF (33,1 ± 3,5 vs 31,0 ± 5,1%, respectively,p>0,05). A trend to higher baseline NT-Pro-BNP level was observed in patients with endpoints (median 1921 pmol/l vs 993 pmol/l, respectively, p = 0,17). The patients with endpoints had higher visit-to-visit SBPV (11,2 ± 4,0 vs 9,5 ± 3,5 mmHg, p < 0,05). Endpoints occurrence significantly correlated with DM (r = 0,20), NYHA grade (r = 0,21) and visit-to-visit SBPV (r = 0,22, p < 0,05 for all). Nonlinear logistic regression analysis revealed higher risk of adverse outcomes in patients with higher level of visit-to-visit SBPV (OR 1,13, 95% CI 1,0–1,27, p = 0,03). Area under curve (AUC) for visit-to-visit SBPV>10,9 mmHg was 0,74, 95% CI 0,53–0,94 (sensitivity 72,7%, specificity 80%, p = 0,02). Conclusions: Visit-to-visit SBPV is significant predictor of adverse outcomes in patients with stable HF with reduced EF. The threshold of visit-to-visit systolic BPV>10,9 mmHg may be used as prognostic criteria in this patient population.

Altered Lower Extremity Movement Variability in Female Soccer Players During Side-Step Cutting After Anterior Cruciate Ligament Reconstruction

Background: Anterior cruciate ligament (ACL) reconstruction (ACLR) is common after an ACL tear and is thought to restore functional stability to the knee. A recent investigation demonstrated that individuals who have undergone ACLR exhibited increased lower extremity coupling variability during gait, suggestive of altered dynamic stability. However, little is known about whether they exhibit alterations in lower extremity variability during dynamic sport-specific tasks. Purpose: To determine if female soccer players who have had an ACLR demonstrate differences in lower extremity coupling variability as compared with athletes with no history of knee injury during a side-step cutting maneuver. Study Design: Controlled laboratory study. Methods: Ten female soccer players who had undergone ACLR served as the experimental group, and 10 female soccer players with no history of knee ligament injury composed the control group (CON). Three-dimensional kinematics and ground-reaction forces were collected while each participant performed a side-step cutting maneuver. Based on known ACL loading patterns, 7 lower extremity intralimb couplings were created. With use of a vector-coding technique, the coordination variability was calculated for each coupling. Independent t tests were used to determine group differences in variability for each coupling (P ≤ .05). Results: Individuals who had undergone ACLR exhibited increased lower extremity variability during side-step cutting as compared with control subjects in the following couplings: hip rotation/knee abduction-adduction (27.2° ± 11.5° [ACLR] vs 19.7° ± 6.8° [CON]; P = .04), hip flexion-extension/knee abduction-adduction (26.0° ± 13.3° [ACLR] vs 18.6° ± 5.3° [CON]; P = .05), knee abduction-adduction/knee flexion-extension (13.5° ± 5.7° [ACLR] vs 7.3° ± 2.7° [CON]; P < .01), and knee abduction-adduction/knee rotation (26.4° ± 10.8° [ACLR] vs 19.3° ± 4.5° [CON]; P = .03). In addition, there was a trend toward increased variability in the hip rotation/ankle inversion-eversion coupling (22.9° ± 9.3° [ACLR] vs 18.0° ± 6.7° [CON]; P = .09) and knee abduction-adduction/ankle inversion-eversion coupling (25.9° ± 10.0° [ACLR] vs 20.2° ± 9.7° [CON]; P = .10). Conclusion: Female soccer players who have undergone ACLR and returned to sports participation exhibit altered lower extremity coupling variability during side-step cutting. Clinical Relevance: While individuals who have had an ACLR exhibit mechanical knee stability before returning to sports, the observed increased movement variability during side-step cutting is likely reflective of altered neuromuscular control and may contribute to the known increased risk for ACL reinjury and knee osteoarthritis after return to sports participation. Improving the understanding of altered lower extremity coupling variability after ACLR will aid in the development of more effective rehabilitation programs.

Osteoprotegerin is not a determinant of metabolic syndrome in sub-Saharan Africans after age adjustment

ObjectivesOsteoprotegerin (OPG), a soluble member of tumor necrosis factor receptor superfamily that inhibits bone resorption, has been suggested as a cardiovascular risk factor in humans. In this study, we aim to investigate the potential relationship between OPG and MetS (MetS) in a sub-Saharan African population. MethodsFour hundred and eleven volunteers (152 men, 259 women) aged ≥18years recruited from the general population in Douala and Edea, Cameroon participated in this study. Anthropometric parameters measured and blood samples were collected for glucose, serum lipids and OPG concentrations measurements. Mean differences of the variables in different groups were compared using Students’ t test. We performed logistic regressions to analyze the impact of independent factors on the relation between OPG and MetS outcome. MetS was defined using the Joint Interim Statement 2009. ResultsOPG levels did not vary significantly between both men and women with and without MetS (both P>0.05). However, with high fasting blood glucose (≥5.6mmol/L) had a significantly higher OPG level than those with lower glucose level (P=0.014). In multiple logistic regression analysis, MetS did not show any significant association with serum OPG levels in men and women after adjusting for age, physical activity, alcohol consumption and menopausal status in women (P=0.720 and P=0.930 respectively). ConclusionThis study failed to demonstrate any relationship between OPG and MetS. Nevertheless, the positive association between blood glucose and OPG levels reveals that OPG might be involved in cardiovascular risk development in this sub-Saharan African population.