Frequency of awake bruxism behaviours in the natural environment. A 7-day, multiple-point observation of real-time report in healthy young adults.

The aim of this study was to assess awake bruxism (AB) behaviours in a sample of healthy young adults using a smartphone-based application for a real-time report (ie, ecological momentary assessment [EMA], also called experience sampling method [ESM]). Forty-six dental students used a smartphone application that sent 15 alerts at random intervals during the day for 1 week to collect AB self-reports. They had to answer on time by tapping on the display icon that refers to their current condition of jaw muscles: relaxed; teeth contact; teeth clenching; teeth grinding; jaw clenching without teeth contact (ie, bracing). The average frequency of relaxed jaw muscles, as a percentage of answers over the 7 days, was 71.7%. Teeth contact (14.5%) and jaw clenching (10.0%) were the most frequent AB behaviours. No significant gender differences were detected. Interindividual differences were quite relevant, but the overall frequency was in general only moderately variable from day-to-day. Coefficient of variation (CV) was low for the condition "relaxed jaw muscles" (0.44). At the individual level, teeth contact was the most prevalent behaviour, with a 39.1%-52.2% proportion of subjects reporting it at least once a day. During a 7-day observation period, the frequency of real-time report of AB behaviours in a sample of healthy young adults was 28.3%. The low daily variability in the average frequency value for the relaxed jaw muscles condition suggests that EMA may be a reliable strategy to get deeper into the epidemiology of oral behaviours. This investigation introduced EMA principles to the study of AB and provided data on the frequency of AB behaviours in young adults that could be compared to populations with risk/associated factors and possible clinical consequences.

The clinical use of statistical permutation test methodology: a tool for identifying predictive variables of outcome.

OBJECTIVES: To identify the predictive variables affecting the outcome after radical surgery for bladder cancer by a newer statistical methodology, i.e. nonparametric combination (NPC). METHODS: A multicenter study enrolled 1,312 patients who had undergone radical cystectomy for bladder cancer in 11 Italian oncological centers from January 1982 to December 2002. A statistical analysis of their medical history and diagnostic, pathological and postoperative variables was performed using a NPC test. The patients were included in a comprehensive database with medical history and clinical and pathological data. Five-year survival was used as the dependent variable, and p values were corrected for multiplicity using a closed testing procedure. The newer nonparametric approach was used to evaluate the prognostic importance of the variables. All of the analyses were performed using routines developed in MATLAB© and the significance level was set at α = 0.05. RESULTS: A significant prognostic predictive value (p < 0.01) for tumor clinical staging, hydronephrosis, tumor pathological staging, grading, presence of concomitant carcinoma in situ, regional lymph node involvement, corpora cavernosa invasion, microvascular invasion, lymphatic invasion and prostatic stroma involvement was found. CONCLUSIONS: The NPC test could handle any type of variable (categorical and quantitative) and take into account the multivariate relation among variables. This newer methodology offers a significant contribution in biomedical studies with several endpoints and is recommended in presence of non-normal data and missing values, as well as solving high-dimensional data and problems relating to small sample sizes.

Testing marginal homogeneity against stochastic order in multivariate ordinal data.

SUMMARY: Many assessment instruments used in the evaluation of toxicity, safety, pain, or disease progression consider multiple ordinal endpoints to fully capture the presence and severity of treatment effects. Contingency tables underlying these correlated responses are often sparse and imbalanced, rendering asymptotic results unreliable or model fitting prohibitively complex without overly simplistic assumptions on the marginal and joint distribution. Instead of a modeling approach, we look at stochastic order and marginal inhomogeneity as an expression or manifestation of a treatment effect under much weaker assumptions. Often, endpoints are grouped together into physiological domains or by the body function they describe. We derive tests based on these subgroups, which might supplement or replace the individual endpoint analysis because they are more powerful. The permutation or bootstrap distribution is used throughout to obtain global, subgroup, and individual significance levels as they naturally incorporate the correlation among endpoints. We provide a theorem that establishes a connection between marginal homogeneity and the stronger exchangeability assumption under the permutation approach. Multiplicity adjustments for the individual endpoints are obtained via stepdown procedures, while subgroup significance levels are adjusted via the full closed testing procedure. The proposed methodology is illustrated using a collection of 25 correlated ordinal endpoints, grouped into six domains, to evaluate toxicity of a chemical compound.

Prognostic significance of the evaluation of bronchoalveolar lavage cell populations in patients with HIV-1 infection and pulmonary involvement.

To investigate the prognostic utility of the morphologic and immunologic evaluation of BAL cell populations in determining mortality risk, we analyzed BAL data obtained from 115 patients infected with HIV-1. Forty fatal outcomes occurred within 73 patients with OI. The OI patients who died showed a significant increase in neutrophils with respect to surviving patients. Furthermore, the finding of a BAL neutrophilia in HIV-1-infected patients with OI strongly correlated with a high risk of death. Among 42 cases without OI, 11 patients died. Patients without OI who had a fatal outcome showed an increase in CD3+ and CD8+ BAL lymphocytes with respect to the survivors. The presence of a lymphocytic alveolitis was associated with a significant increase in the mortality rate. Taken together our data suggest that the evaluation of the BAL cell populations might be useful in predicting the risk of fatal outcome in patients with HIV-1 infection.

[Thin-needle aspiration cytology of palpable lymph nodes. Analysis of 702 consecutive cases]. / La citologia per aspirazione con ago sottile di linfonodi palpabili. Analisi di 702 casi consecutivi.

Seven-hundred-two needle aspirates were taken from palpable lymph nodes between january 1982 and june 1987. Cytohistological correlation in about 70% of the preparations showed that the technique is capable of detecting neoplastic cells in 99% of metastases and in 90% of lymphoma cases. Certain technical aspects of smear preparation are pointed out with a view to reducing the percentage of inadequate samples (14% in the present series) and the position of the technique among other diagnostic procedures is discussed, with evaluation of advantages and limitations.

A landmark analysis-based approach to age and sex classification of the skull of the Mediterranean monk seal (Monachus monachus) (Hermann, 1779).

This work aimed at applying geometric morphometric analysis techniques to the skull of the Mediterranean monk seal (Monachus monachus, Hermann, 1779). Inferential analyses were performed using a non-parameteric permutation framework based on a series of skulls of different age classes belonging to individuals of both sexes. Our goal was to establish whether a statistical approach based on osteometric measurements and surface analysis of photographs of the left lateral plane of the skull may lead to a different and scientifically sound method of age and sex classification in this critically endangered marine mammal. Our data indicate that non-parametric combination methodology enables the researcher to give local assessment using a combination with domains. Developing geometric morphometric techniques in a non-parametric permutation framework could be useful in solving high dimensional and small sample size problems as well as classification problems, including zoological classification of specimens within a specific population. The Mediterranean monk seal is believed to be the world's rarest pinniped and one of the most endangered mammals of the world, with fewer than 600 individuals currently surviving. The use of shape analysis would allow new insights into the biological characteristics of the monk seal by simply extracting potentially new information on age and size from museal specimens.

Neurobehavioral evaluation in humans exposed to hydrocarbons: a new statistical approach.

BACKGROUND: Epidemiological researches showed a significant increase in the alterations of the cognitive and emotional sphere in subjects exposed to hydrocarbons. This paper deals with a study carried out on a group of male workers between the ages of 35 and 40, who had been working as external workers in a large refinery. METHODS: All the subjects worked in short shift rotation and were exposed to hydrocarbons during the loading of tank trucks. The response data reported by this investigation are compared to data of different male subjects who had also been working at the refinery for the same period of time, but as administrative day workers, and were certainly not exposed to the hydrocarbons. The nonparametric statistical analysis was carried out by a new nonparametric approach based on multivariate permutation tests. RESULTS: Results show a significant difference in the response to neurobehavioral tests. The exposed group showed behavioral tendencies towards anxiety and depression that the nonexposed group did not. CONCLUSIONS: The study shows that occupational exposure to hydrocarbons is associated with neurobehavioral modifications, and that the use of psychometric tests can be useful for monitoring the psychosomatic consequences by exposure to hydrocarbon microdoses.

Affective correlates of occupational exposure to whole-body vibration. A case-control study.

BACKGROUND: Exposure to whole-body vibrations (WBV) represents a highly diffuse occupational risk. Some studies report that chronic exposure to WBV induces a significant increment in the modifications of the cognitive and emotional area. The aim of this study was to investigate the long-term effects of WBV exposure on the neuropsychic and behavioural system. METHODS: The study population consisted of 137 male subjects, mean age 45.7 years, working as drivers of mechanical trolleys and occupationally exposed to WBV of a frequency below 2 m/s2. The Profile of Mood States was administered to all subjects in a maximum time of 10 min and in the same operative conditions. The results were compared with those of a homogeneous control group by means of an innovative statistical technique. RESULTS: The results show a significant difference in the response to the neurobehavioural test. The exposed group showed, in fact, a higher score compared with the controls for all 6 factors. In particular, the scores for factors F (fatigue-inertia), D (depression-dejection) and T (tension-anxiety) were more elevated, expressing a significant alteration of the psycho-affective status. Moreover, statistical analysis showed a correlation between exposure time and the score obtained for all factors in the exposed group. CONCLUSION: This study indicates that occupational exposure to WBV is associated with alterations of mood status and that these modifications are directly proportional to exposure time. Furthermore, our results show that psychological tests commonly used in psychopathologic diagnostics can be useful in monitoring alterations of psycho-emotional status determined by physical stressors.

[Rheologic, coagulative parameters and study of fibrinolysis in patients with coronary heart disease before and after aorto-coronary by-pass (author's transl)]. / Parametri reologici, coagulativi e studio della fibrinolisi nei coronaropatici prima e dopo intervento di by-pass aorto-coronarico.

A study has been made of 31 patients with coronary heart disease where diagnosis had been clearly ascertained both from a clinical and strumental point of view. All patients had undergone aorto-coronary by-pass surgery. The controls of the parameters under observation (whole-blood and plasmatic viscosity, hematocrit, fibrinogen, euglobulin lysis, T protothrombin, T of partial thromboplastin, thromboelastogram antithrombin III, plasminogen, alfa2-macroglobulin and fractions C'3c, C'3c, C'4 of the complement) were carried out as follows: basic sample taken, I control (8th-10th day), II control (15th-20th day), III control (45th-50th day), IV control (85th-90th day) after surgical operation. A global examination of our results showed significant changes in the rheologic coagulative and fibrinolytic parameters after an aorto-coronary surgical operation. The slight tendency toward hypercoagulability met with in the basic blood sample (slight increase of whole-blood viscosity, hyperfibrinogenemy, inhibition of fibrinolytic activity) does not change significantly after surgical operation. This seems to indicate that the coronary by-pass does not in any way alter the evolution of arteriosclerosis.