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This article studies the Type I error, false positive rates, and power of four versions of the Lagrange multiplier test to detect measurement noninvariance in item response theory (IRT) models for binary data under model misspecification. The tests considered are the Lagrange multiplier test computed with the Hessian and cross-product approach, the generalized Lagrange multiplier test and the generalized jackknife score test. The two model misspecifications are those of local dependence among items and nonnormal distribution of the latent variable. The power of the tests is computed in two ways, empirically through Monte Carlo simulation methods and asymptotically, using the asymptotic distribution of each test under the alternative hypothesis. The performance of these tests is evaluated by means of a simulation study. The results highlight that, under mild model misspecification, all tests have good performance while, under strong model misspecification, the tests performance deteriorates, especially for false positive rates under local dependence and power for small sample size under misspecification of the latent variable distribution. In general, the Lagrange multiplier test computed with the Hessian approach and the generalized Lagrange multiplier test have better performance in terms of false positive rates while the Lagrange multiplier test computed with the cross-product approach has the highest power for small sample sizes. The asymptotic power turns out to be a good alternative to the classic empirical power because it is less time consuming. The Lagrange tests studied here have been also applied to a real data set.

We compared systematically the structure and the content of maternal and paternal speech to infant boys and girls while we also investigated the effect of infant’s age. Six girls and five boys were...

This article studies the power of the Lagrange Multiplier Test and the Generalized Lagrange Multiplier Test to detect measurement non-invariance in Item Response Theory (IRT) models for binary data. We study the performance of these two tests under correct model specification and incorrect distribution of the latent variable. The asymptotic distribution of each test under the alternative hypothesis depends on a noncentrality parameter that is used to compute the power. We present two different procedures to compute the noncentrality parameter and consequently the power of the tests. The performance of the two methods is evaluated through a simulation study. They turn out to be very similar to the classic empirical power but less time consuming. Moreover, the results highlight that the Lagrange Multiplier Test is more powerful than the Generalized Lagrange Multiplier Test to detect measurement non-invariance under all simulation conditions.

The present study investigates the way infants express their emotions in relation to parental feelings between maternal and paternal questions and direct requests. We therefore compared interpersonal engagement accompanying parental questions and direct requests between infant–mother and infant–father interactions. We video-recorded spontaneous communication between 11 infant–mother and 11 infant–father dyads—from the 2nd to the 6th month—in their home. The main results of this study are summarized as follows: (a) there aresimilaritiesin the way preverbal infants use their affections in spontaneous interactions with their mothers and fathers to express signs of sensitivity in sharing knowledge through questions and direct requests; and (b) the developmental trajectories of face-to-face emotional coordination in the course of parental questions descend in a similar way for both parents across the age range of this study. Regarding the developmental trajectories of emotional non-coordination, there is evidence of a linear trend in terms of age difference between the parents’ gender with fathers showing the steeper slope. The results are discussed in relation to the theory of intersubjectivity.

Correlated binary responses are very common in longitudinal and repeated measures studies. Random effects models are often used to analyze such data and the h-likelihood estimating procedure provides an inferential tool. The objective of this study is to introduce goodness-of-fit score statistics for the fixed part of these models. The proposed statistics are based on processes that partition the observations into mutually exclusive groups. Weighted versions of these statistics are also introduced and are based on the correlation between an appropriately adjusted candidate covariate for entrance into the model and the model residuals. A simulation study indicates that the weighted statistics perform better than their unweighted counterparts, whereas the statistics that are based on the partitioning of the covariate space seem to perform slightly better compared with those based on other grouping procedures. The use of the proposed statistics is illustrated using a real data example.

Correlated binary responses are very commonly encountered in many disciplines like, for example, medical studies. The development of goodness-of-fit tests is essential for examining the adequacy of the fitted models. The objective of this article is to provide weighted modifications of cumulative sums or moving cumulative sums of residuals for testing goodness-of-fit of random effects logistic regression models. The proposed weights can be interpreted as the residuals of a weighted linear regression of an omitted covariate on the covariates already included in the fixed part of the model. These processes lead to supremum statistics whose null distribution is derived using simulation. Results from a simulation study suggest better performance of the weighted when compared to the unweighted supremum statistics. The proposed tests are illustrated using a real data example.

Objectives: Chronic insomnia (CI) is a common sleep disorder linked to stress and various ubiquitous stress-related disorders (e.g. cardiovascular and mental diseases). Previous experimental studies exploring the effects of stress management in CI have confirmed that reducing stress, especially through cognitive methods, could ameliorate symptoms and repercussions of CI. In this 16-week experimental pilot study, we primarily examined the feasibility of a novel method, dubbed Pythagorean Self-Awareness Intervention (PSAI) in 30 CI patients. Design: This is a pilot experimental study. Setting: Attikon General Hospital, School of Medicine, University of Athens. Interventions: PSAI for a period of 8 weeks (8–16 weeks). Main outcomes: Feasibility data and efficacy measures for sleep quality, cognitive function, perceived stress and hair cortisol. Results: All eligible patient gave their consent to participate and there were no drop-outs or adverse effects. 43.3%, 30% and 26.7% of patients showed high (PSAI twice per day), moderate (at least three times per week) and low (less than three times per week) compliance, respectively. Morning lack of time and evening tiredness were the main reasons for missing home sessions. Significant improvements in sleep quality, cognitive function, hair cortisol and perceived stress were also recorded especially in patients with higher compliance. Conclusions: PSAI is a feasible and possibly efficacious stress management method. Future randomized-controlled studies should explore its efficacy in CI. © 2018 Elsevier Ltd

Objectives Several plaque and lesion characteristics have been associated with an increased risk for procedural stroke during or shortly after carotid artery stenting (CAS). While technical advancements in stent design and cerebral protection devices (CPD) may help reduce the procedural stroke risk, and anatomy remains important, tailoring stenting procedures according to plaque and lesion characteristics might be a useful strategy in reducing stroke associated with CAS. In this descriptive report of the ongoing Asymptomatic Carotid Surgery Trial-2 (ACST-2), it was assessed whether choice for stent and use or type of CPD was influenced by plaque and lesion characteristics. Materials and methods Trial patients who underwent CAS between 2008 and 2015 were included in this study. Chi-square statistics were used to study the effects of plaque echolucency, ipsilateral preocclusive disease (90–99%), and contralateral high-grade stenosis (>50%) or occlusion of the carotid artery on interventionalists' choice for stent and CPD. Differences in treatment preference between specialties were also analysed. Results In this study, 831 patients from 88 ACST-2 centres were included. Almost all procedures were performed by either interventional radiologists (50%) or vascular surgeons (45%). Plaque echolucency, ipsilateral preocclusive disease (90–99%), and significant contralateral stenosis (>50%) or occlusion did not affect the choice of stent or either the use of cerebral protection and type of CPD employed (i.e., filter/flow reversal). Vascular surgeons used a CPD significantly more often than interventional radiologists (98.6% vs. 76.3%; p < .001), but this choice did not appear to be dependent on patient characteristics. Conclusions In ACST-2, plaque characteristics and severity of stenosis did not primarily determine interventionalists' choice of stent or use or type of CPD, suggesting that other factors, such as vascular anatomy or personal and centre preference, may be more important. Stent and CPD use was highly heterogeneous among participating European centres.

We compare matching of facial expressions and attunement of emotional intensity in spontaneous communication of mothers with infants and of fathers with infants, in families in Crete. Eleven infant–mother and 11 infant–father dyads were video-recorded at home in familiar interactions from the 2nd to the 6th month. Microanalysis of infant, maternal and paternal facial expressions of emotion provided evidence of quantitative differences that favour father–infant interaction as more playful, but the infants' behaviours with mothers and fathers show similar developmental curves. These results are discussed in the frame of the theory of innate intersubjectivity and of the emotional support parents give to developing motives of infants.

Correlated binary responses are very common in longitudinal and repeated measures studies. Random effects models are often used to analyze such data and the h-likelihood estimating procedure provides an inferential tool. The objective of this study is to introduce goodness-of-fit score statistics for the fixed part of these models. The proposed statistics are based on processes that partition the observations into mutually exclusive groups. Weighted versions of these statistics are also introduced and are based on the correlation between an appropriately adjusted candidate covariate for entrance into the model and the model residuals. A simulation study indicates that the weighted statistics perform better than their unweighted counterparts, whereas the statistics that are based on the partitioning of the covariate space seem to perform slightly better compared with those based on other grouping procedures. The use of the proposed statistics is illustrated using a real data example.

The present study aimed to investigate for the first time, the alteration of α-N-acetylgalactosaminidase (nagalase) concentration in alcohol-dependent individuals without liver disease, before, during and at the end of the detoxification therapy.Forty-eight alcohol-dependent individuals without liver disease who were admitted for alcohol detoxification, and eighty-four healthy controls participated in this study. Patients' blood was obtained upon admission, two weeks later and after the completion of the detoxification period (4-5 weeks). Nagalase concentration in serum was assessed by enzyme-linked immunosorbent assay.Nagalase concentration was significantly elevated in the patient samples in all serum collections as compared to the normal controls, with a progressive fall from admission to discharge (p-value0.001). Values differed significantly among the three time points, with a net shift to decrease, but remained still high, above normal control level at the end of the therapy. No significant correlations were detected among the nagalase levels and the liver enzymes values. Moreover, no significant correlation was found between the alterations of nagalase concentrations and the amount of consumed alcohol.The high nagalase concentrations in alcohol abuse might be associated with macrophage impairment through decreasing the endogenous macrophage-activating factor (MAF) production by Gc-protein. The possible pathogenetic association between nagalase activity and alcohol overconsumption remains a matter of further investigation. Nagalase could also serve as a marker of alcohol overconsumption for the evaluation of alcohol-dependent individuals before, as well as during the detoxification therapy.

Objective: Even though statin pretreatment is associated with better functional outcomes and lower risk of mortality in acute ischemic stroke, there are limited data evaluating this association in acute ischemic stroke due to large artery atherosclerosis (LAA), which carries the highest risk of early stroke recurrence. Methods: Consecutive patients with acute LAA were prospectively evaluated from 7 tertiary-care stroke centers during a 3-year period. Statin pretreatment, demographics, vascular risk factors, and admission and discharge stroke severity were recorded. The outcome events of interest were neurologic improvement during hospitalization (quantified as the relative decrease in NIH Stroke Scale score at discharge in comparison to hospital admission), favorable functional outcome (FFO) (defined as modified Rankin Scale score of 0-1), recurrent stroke, and death at 1 month. Statistical analyses were performed using univariable and multivariable Cox regression models adjusting for potential confounders. All analyses were repeated following propensity score matching. Results: Statin pretreatment was documented in 192 (37.2%) of 516 consecutive patients with LAA (mean age: 65 ± 13 years; 60.8% men; median NIH Stroke Scale score: 9 points, interquartile range: 5-18). Statin pretreatment was associated with greater neurologic improvement during hospitalization and higher rates of 30-day FFO in unmatched and matched (odds ratio for FFO: 2.44; 95% confidence interval [CI]: 1.07-5.53) analyses. It was also related to lower risk of 1-month mortality and stroke recurrence in unmatched and matched analyses (hazard ratio for recurrent stroke: 0.11, 95% CI: 0.02-0.46; hazard ratio for death: 0.24, 95% CI: 0.08-0.75). Conclusion: Statin pretreatment in patients with acute LAA appears to be associated with better early outcomes regarding neurologic improvement, disability, survival, and stroke recurrence. © 2016 American Academy of Neurology.

This study was designed to evaluate the impact of other common self-reported comorbid disorders (hypertension, dyslipidemia, ischemic heart disease, diabetes mellitus, minor stroke, arthritis, low back pain or osteoporosis and depression) on health-related Quality of Life (HRQoL) of Parkinson's disease (PD) patients and to explore the association of their HRQoL with various sociodemographic and clinical factors.Data about age, gender, education, occupation, income, marital and residential status, social relations, disease duration, functional status, treatment and concomitant diseases were collected of 139 Greek patients (68 men and 71 women) with PD. Patients were consecutively recruited from the outpatient clinic of the first Neurology Department of Athens National University at Aeginition Hospital. Disease severity was assessed using the unified Parkinson's disease rating scale including Hoehn and Yahr and Schwab and England (SE) scales. HRQoL was measured by the specific Parkinson's disease questionnaire (PDQ-39). A multivariate multiple regression model with normal errors was used for the statistical analysis.The main determinants of HRQoL were low degree of independence measured by the SE scale (F = 35.942, p0.001), social isolation (F = 20.508, p0.001), disease duration (F = 14.983, p0.001), sleep (F = 6.507, p = 0.013) and gastrointestinal disturbances (F = 4.643, p = 0.035) and the presence of depression (F = 6.022, p = 0.017).Among the other chronic comorbidities only depression was associated with a poor HRQoL in PD patients. Functional dependence and social isolation contributed most to worse HRQoL. Our findings suggest that adequate social support and management of depression, sleep and gastrointestinal disturbances could reduce the distress and improve HRQoL in patients with PD.

We propose a novel methodology to construct proposal densities in reversible jump algorithms that obtain samples from parameter subspaces of competing generalized linear models with differing dimensions. The derived proposal densities are not restricted to moves between nested models and are applicable even to models that share no common parameters. We illustrate our methodology on competing logistic regression and log-linear graphical models, demonstrating how our suggested proposal densities, together with the resulting freedom to propose moves between any models, improve the performance of the reversible jump algorithm. Copyright 2011, Oxford University Press.

The aim was to compare the effect of scaling and root planing (SRP) alone, diode laser treatment (LAS) alone, and SRP combined with LAS (SRP + LAS) on clinical and microbial parameters in patients with aggressive periodontitis.Thirty patients with aggressive periodontitis were assessed for plaque, bleeding on probing (BOP), probing pocket depth (PPD), and clinical attachment level (CAL). Four plaque samples were randomly obtained, one from each quadrant that was randomly assigned to SRP alone, SRP + LAS, LAS alone, and control (CRL). A 980-nm diode laser was used in continuous mode at 2 W power. Plaque samples were collected 2 wk, 12 wk, and 6 mo post-treatment. The levels of Porphyromonas gingivalis, Tannerella forsythia, Aggregatibacter actinomycetemcomitans, Treponema denticola, and total bacterial load (TBL) were evaluated using ssrRNA probes.Bacterial counts were decreased with all three treatment modalities and they did not reach baseline levels at 6 mo post-treatment. The SRP + LAS group showed statistically significantly lower TBL and bacterial levels of P. gingivalis and T. denticola at 6 mo post-treatment compared to SRP or LAS treatments alone. At the end of the observation period significant differences were observed for PPD and CAL between the SRP + LAS group and both the SRP alone and LAS alone groups. No differences were detected for percentage of plaque and percentage of BOP between any of the treatment groups at 6 mo post-treatment.Within the limits of this study, diode laser-assisted treatment with SRP showed a superior effect over SRP or LAS alone for certain microbial and clinical parameters in patients with aggressive periodontitis over the 6-mo monitoring period.

The classical growth curve model is considered when one continuous characteristic is measured at q time points. The covariance adjusted estimator of growth curve parameters is the OLS estimator adjusted using analysis of covariance. The covariates are obtained from functions of within individuals error contrasts. On the other hand, REML estimators emerge from maximization of the likelihood of OLS residuals. We compare the efficiency of estimators of growth curve parameters obtained by REML with that of covariance-adjusted least squares estimators with covariates selected via CAIC.

OBJECTIVE: To study the expression of IL-1beta, IL-4, and IL-8 in the gingival crevicular fluid (GCF) of children, adolescents, and young adults with and without fixed orthodontic appliances. MATERIAL AND METHODS: Eighty systemically healthy children and adolescents participated in the study: 56 aged between 8 and 16 years without any orthodontic appliance (Group A) and 24 aged between 10 and 20 years having worn fixed orthodontic appliances for at least 12 months (Group B). Clinical examination included presence or absence of plaque, probing depth, bleeding on probing, and gingival overgrowth. GCF was collected by means of Durapore strips from four randomly selected sites per subject. The contents of interleukin-1 beta (IL-1beta), interleukin-4 (IL-4), and interleukin-8 (IL-8) were detected by ELISA, measured as total amounts (pg/30s) and expressed in log scale. RESULTS: Statistically significant differences were noted for the mean log IL-1beta, IL-4, and IL-8 between the two groups: Group B showed significantly higher mean levels in log IL-1beta and log IL-8 compared to Group A. Mean levels of log IL-4 were lower in Group B, although they did not reach statistical significance. Furthermore, mean levels of log IL-1beta and log IL-8 were associated with bleeding sites (p

Heteroscedastic additive and multiplicative models are proposed to disaggregate household data on water consumption from Athens and provide individual consumption estimates. The models adjust for heteroscedasticity assuming that variances relate to covariates. Household characteristics that can influence consumption are also included into models in order to allow for a clearer measurement of individual characteristics effects. Estimation is accomplished through a penalized least squares approach. The method is applied to a sample of real data related to domestic water consumption in Athens. The results show a greater consumption of water for males while the single-female households are these that use the lowest quantities of water. The consumption curves by age and gender are constructed presenting differences between the two sexes.

Evaluate the impact of reduced gastric acid secretion after administration of two acid-reducing agents on the physicochemical characteristics of contents of upper gastrointestinal lumen of fasted adults. Eight healthy male adults, fasted from food for 12 h, participated in a three-phase crossover study. Phase 1: No drug treatment prior to aspirations. Phase 2: Oral administration of 40 mg pantoprazole at ~9 am the last 3 days prior to aspirations and at ~7 am on aspiration day. Phase 3: Oral administration of 20 mg famotidine at ~7 pm prior to aspirations and at ~7 am on aspiration day. Samples from the contents of upper gastrointestinal lumen were aspirated for 50 min, after administration of 240 ml table water at ~9 am. Reduction of gastric acid secretion was accompanied by reduced buffer capacity, chloride ion concentration, osmolality and surface tension in stomach and by increased pH (up to ~0.7 units) in upper small intestine during the first 50 min post-water administration. The mechanism of reduction of acid secretion seems to be important for the buffer capacity in stomach and for the surface tension in upper gastrointestinal lumen. Apart from gastric pH, reduced acid secretion affects physicochemical characteristics of contents of upper gastrointestinal lumen which may be important for the performance of certain drugs/products in the fasted state.

Composite likelihood estimation has been proposed in the literature for handling intractable likelihoods. In particular, pairwise likelihood estimation has been recently proposed to estimate models with latent variables and random effects that involve high dimensional integrals. Pairwise estimators are asymptotically consistent and normally distributed but not the most efficient among consistent estimators. Vasdekis et al. (Biostatistics 15:677-689, 2014) proposed a weighted estimator that is found to be more efficient than the unweighted pairwise estimator produced by separate maximizations of pairwise likelihoods. In this paper, we propose a modification to that weighted estimator that leads to simpler computations and study its performance through simulations and a real application.

A random effects model is examined in the multivariate setting where more than one characteristics are measured at each time point. ML and REML estimators are obtained under the restriction that estimates of variance matrices being at least p.s.d. It is shown that REML has greater probability of giving full rank estimates of variance components matrices but as regards the efficiency in the estimation of the location parameter, correct specification of the number of random effects is needed. In general, REML provides larger estimates of variance of model parameters than ML.

The study compared, by a prospective, randomized method, 6 treatment options: A: Sclero therapy ; B: High-dose sclerotherapy; C: Multiple ligations; D: Stab avulsion; E: Foam-sclero therapy ; F: Surgery (ligation) followed by sclerotherapy. Results were analyzed 10 years after inclusion and initial treatment. Endpoints of the study were variations in ambulatory venous pressure (AVP), refilling time (RT), presence of duplex-reflux, and number of recurrent or new incompetent venous sites. The number of patients, limbs, and treated venous segments were comparable in the 6 treatment groups, also comparable for age and sex distribution. The occur rence of new varicose veins at 5 years varied from 34% for group F (surgery + sclero) and ligation (C) to 44% for the foam + sclero group (E) and 48% for group A (dose 1 sclero). At 10 years the occurrence of new veins varied from 37% in F to 56% in A. At inclusion AVP was comparable in the different groups. At 10 years the decrease in AVP and the increase in RT (indicating decrease in reflux), was generally comparable in the different groups. Also at 10 years the number of new points of major incompetence was comparable in all treatment groups. These results indicate that, when correctly performed, all treatments may be similarly effective. "Standard," low-dose sclerotherapy appears to be less effective than high-dose sclero and foam-sclerotherapy which may obtain, in selected subjects, results comparable to surgery.

The GMANOVA model is considered when one characteristic is measured at q time points. The covariance adjusted estimator is the OLS estimator adjusted using analysis of covariance. The covariates are obtained from the space vertical to that derived from the design matrix. Its form is obtained as a GLS estimator using a weight matrix of reduced rank unless all available covariates are used. The choice of the appropriate covariate combination is made by introducing a method based on cross validation (CV). A comparison is made with two other methods that appeared in statistical literature using simulation.

Models with random effects/latent variables are widely used for capturing unobserved heterogeneity in multilevel/hierarchical data and account for associations in multivariate data. The estimation of those models becomes cumbersome as the number of latent variables increases due to high-dimensional integrations involved. Composite likelihood is a pseudo-likelihood that combines lower-order marginal or conditional densities such as univariate and/or bivariate; it has been proposed in the literature as an alternative to full maximum likelihood estimation. We propose a weighted pairwise likelihood estimator based on estimates obtained from separate maximizations of marginal pairwise likelihoods. The derived weights minimize the total variance of the estimated parameters. The proposed weighted estimator is found to be more efficient than the one that assumes all weights to be equal. The methodology is applied to a multivariate growth model for binary outcomes in the analysis of four indicators of schistosomiasis before and after drug administration.

Recasting the role of fruit and vegetables (F&V) in the diet, and planning national and international campaigns to enhance their consumption are major public health service objectives. The present study seeks to describe F&V availability patterns in ten European countries and examine compliance with current recommendations. The mean and median F&V availability (g/person per d) was estimated based on household budget survey data retrieved from the Data Food Networking (DAFNE) databank. Low F&V consumers were identified based on WHO international recommendations (minimum combined F&V intake of about 400 g/person per d) and current conservative guidelines of a minimum daily intake of three portions of vegetables and two portions of fruit. Considerable disparities in F&V availability were found among the surveyed European populations. Only in Mediterranean countries did the mean daily population intake clearly exceed combined F&V recommendations. Dietary patterns were positively skewed in all populations studied, on account of the presence of exceptionally high values among segments of the populations. Moreover, the correlation was unexpectedly weak between the proportion of low fruit and low vegetable consumers (Spearman's correlation coefficient +0·18). More than 50 % of the households in the surveyed populations are likely to consume less than the recommended daily vegetable intake of three portions, and this applies even to the two Mediterranean populations. The efficiency of F&V promoting strategies may be enhanced if F&V are addressed separately; furthermore, interventions that would specifically focus on vegetables are probably needed.

An additive nonparametric model is proposed for the analysis of household budget surveys data whose estimation reduces to least squares. Parameter estimates are biased. A first-order approximation for the bias is obtained and it is used to bias correct the residuals of the model in order to construct bootstrap confidence intervals for the model parameter estimates. The results show somewhat shorter intervals than pointwise intervals which are based on a normal approximation with less bias.

In this study, 294 patients with acute proximal DVT (deep venous thrombosis) were randomly assigned to receive intravenous standard heparin in the hospital (98 patients) or low-molecular-weight heparin (LMWH) (nadroparin 0.1 mL [equivalent to 100 AXa IU] per kg of body weight subcutaneously twice daily) administered primarily at home (outpatients) or alternatively in hospital (97 patients) or subcutaneous calcium heparin (SCHep) (99 patients, 0.5 mL bid) administered directly at home. The study design allowed outpatients taking LMWH heparin to go home immediately and hospitalized patients taking LMWH to be discharged early. Patients treated with standard heparin or LMWH received the oral anticoagulant starting on the second day, and heparin was discontinued when the therapeutic range (INR 2-3) had been reached. Anticoagulant treatment was maintained for 3 months. Patients treated with SCHep were injected twice daily for 3 months without oral anticoagulants. Patients were evaluated for inclusion and follow-up with color duplex scanning. Venography was not used. In case of suspected pulmonary embolism (PE) a ventilatory-perfusional lung scan was performed. Endpoints of the study were recurrent or extension of DVT, bleeding, the number of days spent in hospital, and costs of treatments. Of the 325 patients included, 294 completed the study. Dropouts totaled 31 (10.5%); six of the 325 included patients (1.8%) died from the related, neoplastic illness. Recurrence or extension of DVT was observed in 6.1% of patients in the LMWH group, in 6.2% in the standard heparin group, and in 7.1% in the SCHep group. Most recurrences (11/17) were in the first month in all groups. Bleedings were all minor, mostly during hospital stay. Hospital stay in patients treated with LMWH was 1.2 ± 1.4 days in comparison with 5.4 ± 1.2 in those treated with standard heparin. There was no hospital stay in the SCHep group. Average treatment costs in 3 months in the standard heparin group (US $2,760) were considered to be 100%; in comparison costs in the LMWH group was 28% of the standard heparin and 8% in the SCHep group. This study indicated that LMWH and SCHep can be used safely and effectively to treat patients with proximal DVT at home at a lower cost.

Eleven infant–mother dyads in Crete were videod during spontaneous interactions at home, from the second to the sixth month of life. Micro-analysis was used to investigate‘coordination'and ‘non-matching’ of facial expressions of emotion. ‘Emotional coordination’ was evaluated with four measures: matching of facial expressions, completion when one responded to the other with ‘pleasure’ or ‘interest’, synchrony by matching frequency of change or rhythm of emotional expressions, and attunement when shifts of emotional intensity of the two partners were in the same direction.‘Emotional non-matching'was coded when neither the infant nor the mother showed interest in interacting with the other. In emotional coordination or non-matching between mother and infant, who performed first was also recorded. We obtained evidence of emotional matching, synchrony, and attunement. Importantly, the probability of emotional non-matching by the infant was higher than the probability of emotional matching and completion, indicating a tendency for thoughtful attention or playful rivalry in the responses of infants, who also initiated emotional matching, completion, and non-matching more frequently than mothers. The probability of expression of emotional matching, completion, and non-matching changed with age. Both mothers and infants act to obtain sympathetic complementarity of feelings and co-operative inter-synchrony of actions. Copyright © 2016 John Wiley & Sons, Ltd.

Models for growth curves or repeated measurements usually consist of a polynomial trend for the mean response plus error terms. We consider a general covariance structure for the errors which includes a class of autoregressive models with ‘change- points’. Such models depend on a small number of parameters, but are of sufficient generality to be useful in practical applications, especially when enviromental or physiological changes on different times lead to nonstationary error processes. Failure to take this into account leads to inefficient estimatiors of the mean trend. The estimation procedure includes both ML and REML methods. The effect of using these methods on the efficiency of the estimation is also studied by theoretical and Monte Carlo methods.

The paper proposes a composite likelihood estimation approach that uses bivariate instead of multivariate marginal probabilities for ordinal longitudinal responses using a latent variable model. The model considers time-dependent latent variables and item-specific random effects to be accountable for the interdependencies of the multivariate ordinal items. Time-dependent latent variables are linked with an autoregressive model. Simulation results have shown composite likelihood estimators to have a small amount of bias and mean square error and as such they are feasible alternatives to full maximum likelihood. Model selection criteria developed for composite likelihood estimation are used in the applications. Furthermore, lower-order residuals are used as measures-of-fit for the selected models.

Background/aim: The purpose of this study was to compare the levels of the cytokines interleukin-1β (IL-1β), IL-4, and IL-8 in the gingival crevicular fluid (GCF) of adolescents and young adults. Methods: Twenty-five adolescents aged between 14 and 16 years (Group A) and 20 periodontally healthy young adults aged between 25 and 35 years (Group B) were selected from two private dental clinics limited to pedodontics and periodontics respectively in Piraeus Greece. All subjects were systemically healthy. Clinical examination included probing pocket depth (PPD), presence or absence of plaque, and bleeding on probing (BOP). GCF was collected from four sites per subject. IL-1β, IL-4, and IL-8, measured as total amounts (pg/30 s), were evaluated in 180 samples using a commercially available sandwich enzyme-linked immunosorbent assay. Results: IL-1β mean levels of Groups A and B were adjusted for BOP and PPD. Differences of IL-1β mean levels between the two age groups were statistically significant (F = 50.245, P

The paper proposes a full information maximum likelihood estimation method for modelling multivariate longitudinal ordinal variables. Two latent variable models are proposed that account for dependencies among items within time and between time. One model fits item-specific random effects which account for the between time points correlations and the second model uses a common factor. The relationships between the time-dependent latent variables are modelled with a non-stationary autoregressive model. The proposed models are fitted to a real data set.

Background: Cigarette smoking and stress are considered risk factors that have been associated with periodontal disease progression. Conflicting results have been reported concerning the direct influence of smoking on the subgingival microbiota of periodontitis patients. Cytokine production may also be influenced by smoking and stress leading to an imbalance that disturbs the host–parasite relationship. Aim: The objective of the present study was to evaluate the influence of cigarette smoking on the gingival crevicular fluid (GCF) levels of interleukin (IL)-1β, IL-4, IL-6 and IL-8 in aggressive or early onset periodontitis (EOP) patients and in healthy controls (H), psychosocial stress being considered as modifying factor. Material and Methods: Sixty-five EOP and 35 periodontally healthy individuals participated in this cross-sectional study. All the participants were interviewed about their smoking habits and their stressful social events. Clinical examination included the assessment of plaque index (PI), bleeding on probing (BOP), clinical attachment level (CAL) and probing pocket depth (PPD). GCF was collected using durapore strips, from four sites per patient, randomly selected in each quadrant. The total amounts of IL-1β, IL-4, IL-6 and IL-8 were measured in a total of 400 samples using commercially available enzyme-linked immunosorbent assays. Results: All clinical parameters were significantly higher in the EOP group compared to the H group. There were no significant differences between EOP smokers and EOP non-smokers with regard to plaque accumulation, CAL and PPD of the sampling sites, whereas mean CAL and PPD of the diseased sites were greater in EOP smokers than in EOP non-smokers. In addition, EOP smokers seemed to have significantly less BOP and greater bone loss compared to EOP non-smokers. Significant interactions between “EOP” and “smoking” were present for total amounts of IL-1β and IL-4. IL-1β, IL-6 and IL-8 showed significant main effects with healthy smokers and healthy non-smokers, respectively. For IL-8, stress presented a statistically significant interaction with smoking status and EOP (F=4.742, p=0.030). More specifically EOP smokers were statistically affected by stress. Conclusions: Smoking influences host-related factors including cytokine network. The relative importance of smoking and stress-related alterations and their precise mode of action in increasing the risk of aggressive periodontitis remains to be elucidated.

The aim of this study was to evaluate the prevalence and incidence of venous diseases and the role of concomitant/risk factors for varicose veins (VV) or chronic venous insufficiency (CVI). The study was based in San Valentino in Central Italy and was a real whole-population study. The study included 30,000 subjects in eight villages/towns evaluated with clinical assessment and duplex scanning. The global prevalence of VV was 7%; for CVI, the prevalence was 0.86% with 0.48% of ulcers. Incidence (new cases per year) was 0.22% for VV and 0.18% for CVI; 34% of patients with venous disease had never been seen or evaluated. The distribution of VV and CVI in comparison with duplex-detected incompetence (DI) indicates that 12% of subjects had only VV (no DI), 2% had DI but no VV, 7.5% had DI associated with VV, 2% apparent CVI without DI, 3% DI only (without CVI), and 1.6% both CVI and DI. VV associated with DI are rapidly progressive and CVI associated with DI often progresses to ulceration (22% in 6 years). VV without significant DI (3%) and venous dilatation without DI tend to remain at the same stage without progression for a lengthy time. New cases per year appear to have a greater increase in the working population (particularly CVI) possibly as a consequence of trauma during the working period. In older age (> 80 years), the incidence of CVI tends to decrease. Ulcers increase in number with age. Only 22% of ulcers can be defined as venous (due to venous hypertension, increased ambulatory venous pressure, shorter refilling time, obstruction and DI). Medical advice for VV or CVI is requested in 164 subjects of 1,000 in the population. In 39 of 1,000, there is a problem but no medical advice is requested and in only 61 of 1,000, the venous problem is real. In VV in 78% of limbs, there is only reflux, in 8% only obstruction, and in 14% both. In CVI, 58% of limbs have reflux, 23% obstruction, and 19% both. In conclu sion, VV and CVI are more common with increasing age. The increase with age is linear. There was no important difference between males and females. These results are the basis for future real, whole population studies to evaluate VV and CVI.

The efficacy, safety and cost of pentoxifylline (PXF) in severe intermittent claudication was studied comparing PXF and placebo in a 12-month study. A treadmill test and microcirculatory evaluation with laser Doppler flowmetry were performed at inclusion and at the end of 6 and 12 months. A physical training plan (based on walking) and reduction in risk factor levels plan was used in both groups. Of the 120 included patients, 101 completed the study: 56 in the PXF group and 45 in the placebo group. There were 19 dropouts (due to low compliance). The two groups were comparable for age, sex distribution, walking distance, and the presence of risk factors and smoking. Intention-to-treat analysis indicated a 268% increase in walking distance in the PXF group (vs 198% in the placebo group; p0.05) at 6 months and an increase of 404% (vs 280% in the placebo group; p0.02) at 12 months. The absolute and percent increase in pain-free walking distance (PFWD) was greater in the PXF group (p0.05). Treatment was well tolerated. No serious drug-related side effects were observed. Microcirculatory evaluation indicated an increase in flux (p0.05) in the PXF group (not significant in the placebo group); the after-exercise flux (AEF) was increased (p0.05) in both groups at 6 months but the increase in AEF was greater in the PXF group at 12 month. In conclusion, between-group analysis favors PXF considering walking distance and microcirculatory parameters. Results indicate good efficacy and tolerability.

The efficacy, safety, and cost of pentoxifylline (PXF) in long-range (400 m interval) intermittent claudication was studied comparing PXF and placebo in a 12-month study. A standardized treadmill test was performed at inclusion and at 6 and 12 months. A training plan based on walking was associated with the control of risk factor levels. Of the 194 included patients, 135 completed the study: 75 in the PXF group and 60 in the placebo group. There were 59 dropouts (due to low compliance). The authors observed a 148% increase in total walking distance (TWD) at 6 months with PXF (vs 110% with placebo; p0.05); at 12 months, the increase was 170% with PXF (vs 131% with placebo; p0.02). There was a 38% difference at 6 months and 39% at 12 months in favor of PXF. Treatment was well tolerated. In conclusion, PXF improved walking distance significantly better than placebo.

Infusional, cyclic PGE 1 treatment is effective in patients with intermittent claudication and critical limb ischemia (CLI). One of the problems related to chronic PGE1 treatment in vascular diseases due to atherosclerosis is to evaluate the variations of clinical condi tions due to treatment in order to establish the number of cycles per year or per period (in severe vascular disease reevaluation of patients should be more frequent) needed to achieve clinical improvement. In a preliminary pilot study a group of 150 patients (mean age 67 ± 12 years) with intermittent claudication (walking range from 0 to 500 m) and a group of 100 patients with CLI (45% with rest pain, and 55% gangrene; mean age 68 ± 11 years) the number of PGE1 cycles according to the short-term protocol (STP) needed to produce significant clinical improvement was preliminarily evaluated. Considering these preliminary observations, the investigators established a research plan useful to produce nomograms indicating the number of cycles of PGE1-STP per year needed to improve the clinical condition (both in intermittent claudication and CLI). A significant clinical improvement was arbitrarily defined as the increase of at least 35% in walking distance (on treadmill) and/or the disappearance of signs and symptoms of critical ischemia in 6 months of treatment in at least 75% of the treated patients. With consideration of the results obtained with the preliminary nomograms a larger validation of the nomograms is now advisable. A cost-effectiveness analysis is also useful to define the efficacy of treatment on the basis of its costs. The publication of this report in two angiological journals (Angeiologie and Angiology) will open the research on nomograms to all centers willing to collaborate to the study. The data are being collected in the ORACL.E database and will be analyzed within 12 months after the publication of this report.

The study was planned to evaluate efficacy and costs of endovascular sclerotherapy (ES) in comparison with surgery and surgery associated with sclerotherapy in a prospective (10-year follow-up), good-clinical-practice study. Patients with varicose veins and pure, superficial venous incompetence were included. Of the patients randomized into the three groups 39 (group A) were treated with ES, 40 (B) with surgery + sclerotherapy, and 42 with surgery only (C). Surgery consisted of ligation of the SFJ (saphenofemoral junction) and of incompetent veins detected with color duplex. Of the preselected 150 patients, 121 subjects entered the study; 96 completed the 10-year follow-up (mean age 52.6 ±6 years; 51 men, 45 women). Dropouts were due to nonmedical problems. At 10 years no incompetence was observed in subjects treated with SPJ ligation (B and C). In the ES group 18.8% of the SFJs were patent and incompetent and in 43.8% of limbs the distal (below-knee) venous system was still incompetent [16.1% in the surgery + scle rotherapy group (p < 0.05) and 36% in the group treated with surgery only (p < 0.05 vs B and 0.05 vs A)]. Color duplex of the long saphenous vein indicated atrophy or obstruc tion of a segment (average 6.7 cm) after SFJ ligation (4.2 cm after ES). The cost of ES was 68% of surgery while the cost of surgery and sclerotherapy was 122% of surgery only. Endovascular sclerotherapy is an effective, cheaper treatment option, but surgery after 10 years is superior.

The efficacy, safety, and cost of prostaglandin E1 (PGE1) in the treatment of severe inter mittent claudication was studied by comparing a long-term treatment protocol (LTP) with a short-term treatment protocol (STP) in a randomized 20-week study. The study included 109 patients (96 completed the study) with an average total walking distance of 65.5 ±8 m (range 20-109). Phase 1 was a 2-week run-in phase (no treatment) for both protocols. In LTP, phase 2 was the main treatment phase. In the LTP, treatment was performed with 2-hour infusions (60 μg PGE1, 5 days each week for 4 weeks). In phase 3 (4-week interval period) PGE 1 was administered twice a week (same dosage). In phase 4 (monitoring lasting 3 months, from week 9 to 20) no drugs were used. In STP, phase 2 treatment was performed in 2 days by a 2-hour infusion (1st day: morning 20 μg, afternoon 40 μg; 2nd day morning and afternoon 60 μg). The reduced dosage was used only at the first cycle (week 0) to evaluate reduced tolerability or side effects. Full dosage (60 μg bid) was used for all other cycles. The same cycle was repeated at the beginning of weeks 4, 8, and 12. The observation period was between weeks 12 and 20. A treadmill test was performed at inclusion, at the beginning of each phase, and at the end of the 20th week. A similar progressive physical training plan (based on walking) and a reduction in risk factors levels plan was used in both groups. Intention-to-treat analysis indicated an increase in walking distance, which improved at 4 weeks (101.5% in STP vs 78.3% in LTP), at 8 weeks (260.9% STP vs 107.3% LTP), and at 20 weeks (351% STP vs 242% LTP). Comparable increases in pain-free walking distance were observed in the two groups. No serious drug-related side effects were observed. Local, mild adverse reactions were seen in 7% of the treated subjects in the LTP and 5% in the STP. Average cost of LTP was ~6,588 ECU; for STP the average cost was ~1,881 ECU. The cost to achieve an improvement in walking distance of 1 m was 35.6 ECU with the LTP and 9.45 ECU with the STP (26% of the LTP cost; p1 (including infusion and operative costs) was 25% of the total cost for LTP (24.9% for STP). In summary, between-group-analysis favors STP, in terms of walking distance and costs. Results indicate good efficacy and tolerability of PGE1 treatment. With STP less time is spent in infusion and more can be spent in the exercise program. STP reduces costs, speeds up rehabilitation, and may be used in a larger number of nonspecialized units available to follow the protocol.

Two hundred thirty-six limbs of 220 unselected patients who were admitted with venous problems (83 with ulcers) were studied with continuous-wave Doppler ultrasonography, duplex scanning, and ambulatory venous pressure measurements. Patients with evidence of deep venous disease because of reflux or obstruction in the deep veins on Doppler and duplex ultrasonic examination or with an ambulatory venous pressure greater than 45 mm Hg despite the ankle cuff had venography. One hundred fifty-three limbs had superficial venous disease (reflux in the superficial veins with competent popliteal valves), and 83 limbs had deep venous disease (popliteal reflux on duplex examination or deep venous obstruction on venography). No ulceration occurred in limbs with ambulatory venous pressure30 mm Hg, and there was a 100% incidence with ambulatory venous pressure90 mm Hg. A linear increase occurred from 14% in limbs with ambulatory venous pressure between 31 and 40 mm Hg to 100% in limbs with ambulatory venous pressure greater than 90 mm Hg (r = 0.79). In the groups studied, an increased incidence of ulceration was associated with an increase in ambulatory venous pressure irrespective of whether the venous problem was the result of superficial or deep venous disease. Ambulatory venous pressure has both diagnostic and prognostic significance in patients with venous disease.

Chronic venous insufficiency (CVI) is the result of outflow obstruction, reflux or a combination of both. Noninvasive tests detect an quantify obstruction and reflux if present and define the anatomic localisation of the abnormality. In evaluating CVI noninvasive tests combine physiologic and imaging techniques. These tests are widely available, simple, quick and cost-effective and therefore they are the methods of choice for initial objective evaluation. Different tests provide answers to different questions. The optimum clinically useful information can be now obtained using only three instruments: pocket Doppler, duplex or color duplex scanner and air plethysmography. The value of ambulatory venous pressure, photoplethysmography and light reflection reography, air plethysmography, duplex and color duplex scanning to assess reflux and the value of tests to assess out-flow obstruction are presented. Pooled data collected from large studies are also presented for reference. Qualitative and quantitative assessment of CVI are useful both for clinical assessment and to evaluate the effect of treatments.

Three techniques for treatment of chronic venous incompetence on an out patients basis were compared in a randomised study. One hundred thirty eight limbs (107 patients) with superficial venous incompetence were randomly treated with the dentist's technique (DT) [Group A, 44 limbs], compression sclerotherapy (CS) [Group B, 45 limbs] or the SAVAS (section en Ambulatoire des Varices avec Sclérothérapie) technique [Group C, 49 limbs]. Patients were evaluated and followed up (every year for 4 years) with ambulatory venous pressure (AVP) measurements and Quantum angiodynography (colour duplex scanning). DT consisted in the section under local anesthesia of incompetent veins. CS was done injecting polidocanol 3% with compression applied for 4 weeks. The SAVAS was done with a combination of DT and CS with section of the incompetent veins under local anesthesia and retrograde injection in the distal vein of polidocanol 3%. With this type of injection only incompetent veins were perfused. After 4 years there was a significantly lower refilling time (RT) with AVP in the SAVAS group (21 sec). RT was 13 sec in group B and 16 in A. The number of significantly incompetent residual veins was in average 0.5 in the SAVAS group, significantly lower than in the other two groups. Also the average cost per treated limb was significantly lower in the SAVAS group (917 francs in comparison with 1100 in group A and 1211 in group B). In conclusion considering the four year follow up, the SAVAS technique is a more effective treatment of superficial venous incompetence, its hemodynamic value is superior to sclerotherapy alone and its costs are lower.

Surgery of the short saphenous vein is associated with a high recurrence rate because of variations in the anatomy or inadequate clinical examination. To prevent this, accurate definition of the pattern and level of termination of the saphenopopliteal junction and flush ligation is necessary. Clinical examination, Doppler ultrasound, duplex scanning and peroperative venography have been compared to assess the level of termination of the short saphenous vein. In all, 64 limbs of 46 patients were examined. In 39 limbs there was primary short saphenous incompetence, in 13 limbs there was recurrent short saphenous incompetence; in ten of these there was incompetence of the gastrocnemius vein. In 12 limbs a duplex scan did not demonstrate incompetence of the short saphenous vein or gastrocnemius vein. The accuracy of these methods when locating incompetence of the short saphenous vein to within 2 cm of the saphenopopliteal junction was 56 per cent for clinical examination, 64 per cent for Doppler ultrasound and 96 per cent for duplex scanning. When there was no saphenopopliteal junction (9 per cent). duplex scanning correctly detected the pattern of the incompetent vein. The apparent success of clinical examination was because the vein was not felt above the femoral intercondylar groove and 52 per cent of the veins terminated at this level. Duplex scanning is a non-invasive technique which is almost as accurate as venography and provides additional haemodynamic information about the incompetent veins by demonstrating the presence and extent of reflux.

A reduction in the ‘elasticity’ of the venous system has been proposed as a precursor of venous insufficiency, but the concept remains controversial. This study was designed to develop a method of assessing venous elasticity, and to use this method to investigate the aetiology of varicose veins. Simultaneous measurements of calf volume (determined using strain gauge plethysmography) and venous pressure (obtained via a dorsal foot vein) were made during venous occlusion plethysmography. The elastic modulus, K, defined as stress/strain when the veins are full, was calculated from the pressure/volume relationship. The elastic modulus was determined in 19 normal legs, 33 legs with superficial venous insufficiency, 16 legs with deep venous insufficiency, and 18 legs of a high risk group of volunteers or patients without varicose veins but with a strong history of factors associated with their development. The results showed a clear difference in elasticity between normal limbs and limbs with varicose veins, and also between normal limbs and high risk limbs. These results support the hypothesis that reduced elasticity has a role in the development of varicose veins and precedes the onset of valvular incompetence.

Venous reflux in milliliters per second has been measured in individual veins with duplex scanning. Forty-six patients (47 legs) with symptomatic varicose veins have been studied while they were in the erect position. Nineteen legs had skin changes whereas the rest (28 legs) had only varicose veins with no skin changes. In 45 limbs, reflux was confined to one vein only: long saphenous vein in 28, short saphenous vein in nine, and femoropopliteal vein in eight. In one limb, reflux was found in the long saphenous, short saphenous, and femoropopliteal veins, and in another it was found in the long and short saphenous veins. In the latter two limbs the amount of reflux found in each vein was added to obtain the total reflux in the limb. In the limbs with skin changes, reflux (median +/- 90% tolerance levels) was 30 (10 to 53) ml/sec; whereas in limbs with no skin changes it was 10 (3 to 44) ml/sec. Reflux greater than 10 ml/sec was associated with a high incidence of skin changes (66%) irrespective of whether this was in the superficial or deep veins; reflux less than 10 ml/sec was not associated with skin changes.

Skin blood flow in the distal foot was evaluated in patients with peripheral vascular disease and diabetes and compared with skin blood flow in normal volunteers by use of laser Doppler flowmetry. Resting blood flow (RBF) and standing blood flow (SBF) were recorded in a room at a constant temperature (20-22°C). The RBF was found to be different in the five groups (normal, dia betics, patients with intermittent claudication, those with rest pain and those with impending gangrene. In diabetics RBF was significantly higher than in normal subjects. Even on standing, SBF in diabetics was higher and not different from RBF, indicating an ineffective venoarteriolar response (VAR). The VAR was also reduced in pa tients with claudication and was abolished in patients with rest pain and im pending gangrene. In patients with rest pain SBF was increased. Laser Doppler flowmetry is a useful technique for evaluating skin perfusion in patients with peripheral arterial disease and for discriminating among differ ent classes of patients.