Evaluation of Motor Imagery-Based BCI methods in neurorehabilitation of Parkinson's Disease patients.

The study reports the performance of Parkinson's disease (PD) patients to operate Motor-Imagery based Brain-Computer Interface (MI-BCI) and compares three selected pre-processing and classification approaches. The experiment was conducted on 7 PD patients who performed a total of 14 MI-BCI sessions targeting lower extremities. EEG was recorded during the initial calibration phase of each session, and the specific BCI models were produced by using Spectrally weighted Common Spatial Patterns (SpecCSP), Source Power Comodulation (SPoC) and Filter-Bank Common Spatial Patterns (FBCSP) methods. The results showed that FBCSP outperformed SPoC in terms of accuracy, and both SPoC and SpecCSP in terms of the false-positive ratio. The study also demonstrates that PD patients were capable of operating MI-BCI, although with lower accuracy.

Saccadic characteristics in autistic children.

Some studies suggest that individuals with autism present abnormal saccadic eye movements due to an altered strategy for exploration of the surrounding environment. In this study, potential early abnormalities of saccadic movements were explored in 14 male children with autism (5- to 12-year-olds) and in 20 age matched normal males. Only one patient showed clear abnormalities of the "main sequence"; all the other patients, although showing slight changes in saccadic eye movements, did not present classic deficits. Therefore our results did not confirm the presence of saccadic movement alterations in the early stage of autism. Nonetheless, tracts of saccadic initiation failure, continuous changes in saccadic velocity profiles, and instability of fixation were often observed in the autistic population. These findings could be the expression of an early brainstem impairment in autism.

Characteristics of EEG power spectrum during sleep spindle events in ADHD children.

The attention-deficit/hyperactivity disorder (ADHD) is a common psychiatric disorder that interferes with the typical development and both learning and motor functioning in a child's life. Most of the children with ADHD present also sleep problems like difficulties in falling asleep and maintaining sleep. Sleep spindles are characteristic waves of sleep stage 2 in humans and are characterized by a fusiform morphology. In the last years, the empirical evidence indicates that spindles are associated with cognitive faculties and intelligence as well as with several disease states. On the other hand, power spectral analysis of EEG represents a powerful noninvasive tool for examining cerebral behavior. The aim of this study is to evaluate the differences between ADHD and healthy children of the power spectral values in delta, theta, alpha, beta and gamma bands, before, during and after sleep spindles. Our results show significant differences concentrated in the period immediately after spindle epochs, in the left hemisphere of the brain, in almost all bands, with greater values in control than in ADHD children.

Saccadic analysis for early identification of neurological involvement in Gaucher disease.

The early identification of a neurological involvement in Gaucher's Disease (GD) is essential for a correct dosage of the enzymatic therapy. The saccadic eye movement characteristics of 15 patients affected by the non-neurological GD form show normal peak velocity values and some slight alterations of the velocity profiles present in more than 70% of the recorded eye movements in four cases; two of them later developed epilepsy. This fact supports the hypothesis that the presence of alterations in the velocity profile of the most part of saccadic movements is an index of initial neurological involvement. Further evaluations are necessary in order to understand if an increase of therapy dose should be used in all the subjects presenting such saccadic alterations.

Clinical application of low-dose phase contrast breast CT: methods for the optimization of the reconstruction workflow.

Results are presented of a feasibility study of three-dimensional X-ray tomographic mammography utilising in-line phase contrast. Experiments were performed at SYRMEP beamline of Elettra synchrotron. A specially designed plastic phantom and a mastectomy sample containing a malignant lesion were used to study the reconstructed image quality as a function of different image processing operations. Detailed evaluation and optimization of image reconstruction workflows have been carried out using combinations of several advanced computed tomography algorithms with different pre-processing and post-processing steps. Special attention was paid to the effect of phase retrieval on the diagnostic value of the reconstructed images. A number of objective image quality indices have been applied for quantitative evaluation of the results, and these were compared with subjective assessments of the same images by three experienced radiologists and one pathologist. The outcomes of this study provide practical guidelines for the optimization of image processing workflows in synchrotron-based phase-contrast mammo-tomography.

Cyclopean and disconjugate adaptive recovery from post-saccadic drift in strabismic children before and after surgery.

Post-saccadic drift has been analyzed in strabismic children 11-18 yr old, before and after surgery. Before surgery all the subjects had a large multi-component post-saccadic drift. A disconjugate compensation of the drift was not active, but an optimized cyclopean compensation occurred, aimed at minimizing the drift size in both eyes, either with binocular or monocular vision. The drift was directed toward the static offset of the eyes. One week after surgery the drift increased in most cases but the cyclopean compensation still occurred. One week later, a partial disconjugate compensation decreased the drift to levels lower than before surgery. In one subject surgery produced very big three-component drift, exceeding 20 deg. One year after the drift was decreased to < 1 deg. A mathematical model is presented accounting for most of the results.

Characteristics of horizontal smooth pursuit eye movements to sinusoidal stimulation in children of primary school age.

Previous research about the maturation of the smooth pursuit system has been carried out in newborns and in human infants in the first months of life. A lower gain was found with respect to adults (where gain is close to 1), with frequent saccadic intrusions. On the contrary, no data are available about smooth pursuit response in children. To fill this gap, we analyse in this study the level of maturation reached by children over 7 yr old (the minimum age in which a correct test can be done). Using a cosinusoidal stimulation, the smooth pursuit characteristics (velocity and position gains and phases) evaluated in children are compared to the corresponding parameters in adults. Our data show a clear difference between the two groups, in particular for velocity gain values (which are lower in children), and a larger variability in children. Since the influence of fatigue and prediction appears to be small, we conclude that these differences can be justified both by high level psychological or cognitive factors and incomplete maturation of smooth pursuit system in children.

In vitro and in vivo characterization of Indium-111 and Technetium-99m labeled CCK-8 derivatives for CCK-B receptor imaging.

Cholecystokinin (CCK) receptors of the subtype B (CCK-BR) have been shown to be overexpressed in certain neuroendocrine tumors including medullary thyroid cancer. Our recent work has focused on new methods to radiolabel the CCK8 peptide with 111In or 99mTc for CCK-B receptor imaging. Derivatives of CCK8 were obtained by addition at the N-terminus in solid phase of a DTPA derivative (DTPAGlu) linked through a glycine spacer (DTPAGlu-G-CCK8) or cysteine, glycine and a diphenylphosphinopropionyl moiety (PhosGC-CCK8) for labeling with 111In and 99mTc, respectively. CCK-BR overexpressing A431 cancer cell lines were utilized to characterize in vitro properties of the two compounds as well as for generating xenografts in nude mice for in vivo characterization. Both 111In-DTPAGlu-G-CCK8 and 99mTcPhosGC-CCK8 showed similar binding affinities for CCK-BR with dissociation constants of 20-40 nM, were internalized after interaction with the receptor and displayed prolonged cellular retention times. Specific in vivo interaction with the receptor of both CCK8 analogs was observed in our animal model. 111In-DTPAGlu-G-CCK8 showed better target to non-target ratios, although it appeared to be rapidly metabolized after injection and activity cleared through the kidneys. 99mTc-PhosGC-CCK8 was more stable in vivo but showed marked hepatobiliary clearance with resulting high background activity in the bowel. The rapid clearance and lower background obtained with 111In-DTPAGlu-G-CCK8 make this a better candidate for further development.

An algorithm for the automatic differentiation between the speech of normals and patients with Friedreich's ataxia based on the short-time fractal dimension.

In this paper, we describe an algorithm, based on acoustic pattern matching techniques, for providing an automatic, highly reliable distinction between normal and some kind of pathological speech (Friedreich's ataxia disease). For each utterance, the short-time fractal dimension parameter and, for comparison, the zero-crossing and energy ratio parameters are evaluated and used in the classification task by means of a dynamic programming procedure. Although all the parameters are able to differentiate the two groups, the fractal dimension parameter seems to provide a more reliable pattern classification than zero-crossing and energy ratio. Finally, we point out that, to the discrimination purpose, an accurate choice of the utterances to be pronounced by the subjects is to be considered.

[The evaluation of the appropriateness of instrumental exams in cardiology. The case of echocardiography]. / La valutazione dell'appropriatezza degli esami strumentali in cardiologia. Il caso dell'ecocardiografia.

BACKGROUND: The aim of this study was to evaluate the appropriateness and utility rates of echocardiograms performed in 309 patients in an outpatient clinical setting. METHODS: Data were collected by means of a questionnaire filled in by the cardiologists who performed the examinations. Appropriateness was evaluated according to international guidelines and scored as class I: appropriate, class II: doubtful appropriateness, class III: inappropriate; the exam was deemed useful if it was able to influence the clinical decision-making; normalcy rate was also checked. The relationship between both the referring physicians and motivation of the exam and its appropriateness, and the relationship between appropriateness and both the normalcy rate and utility of the exam were assessed. RESULTS: An echocardiogram was requested by the cardiologist in 46% of patients; the more common reasons for the exam were arterial hypertension (26%), cardiac murmur (18%), palpitations (15%), and known coronary artery disease (10%). The echocardiogram was appropriate (class I) in 25% of patients, doubtfully appropriate (class II) in 39% of patients and inappropriate (class III) in 36% of patients. The appropriateness rate between the cardiologists was similar to that of other prescribing clinicians (p = NS). The highest class III rate was found in patients with hypertension, while the highest class I rate was found in patients with a cardiac murmur (p < 0.01). Normalcy rate was lower in class I than in class II and III exams (p < 0.001). The utility rate was higher in class I (76%) than in class II (13%) and III (< 1%) exams (p < 0.01). CONCLUSIONS: International guidelines can be used effectively and safely to identify (not to prescribe) the useless echocardiograms.

Crying of a newborn child: alarm signal or protocommunication?

The purpose of the study was to explore whether the new-born cry is a simple alarm signal or differentiated cries with different meanings. 12 digital audio taped recordings of 6 full-term healthy babies were analysed. Cries of 6 newborns in this preliminary study were recorded in a pain condition after a prick for the hematic check-up the third day after delivery and then while crying spontaneously in the cradle. The sounds were sampled at 44100 Hz with a 16-bit resolution and converted to the .wav format. All the analyses were performed with a software written in the MAT-LAB environment. The most important result was that these new-born children modulated the supralaryngeal tract considerably more in cries following the painful stimulus than in "spontaneous" ones, as would be expected by the hypothesis of crying as "protolanguage."

[HIV infection: results of 4 years of observation (May 1984-May 1988)- of the admitting department of the V. Cervello Hospital in Palermo]. / L'infezione da HIV: risultati di quattro anni di osservazioni (maggio 1984-maggio 1988) presso il centro operativo dell'Ospedale "V. Cervello" di Palermo.

During a period of four consecutive years (1984-1988) more than one thousand of serum samples were obtained from different "at risk" categories of patients with the aim to investigate on the prevalence of anti-HIV antibodies in these populations. Also HIV antigen and HBV markers were investigated in the same people. Some of them were followed up to monitor the various HIV markers and to cultivate biological material from symptomatic cases. All serological investigations were carried out by means of ELISA methods and the Western Blot technique, to confirm positive results. Data obtained from this study showed that: 1. in our area anti-HIV positive people prevail among intravenous drug addicts (IVDA) (42-48%) in contrast to 3.3% of homosexuals, and in 14-16% of subjects or patients declaring themselves "at risk" without stating what of risk it is. 2. HIV antigen was demonstrated in 5% of symptomatic IVDA patients but only in two cases of anti-HIV negative people. 3. HBV markers were found in all categories examined, prevailing in IVDA subjects (72%). 4. Five percent only of anti-HIV negative people followed up through 2-36 mo. seroconverted while only 39.7% of anti-HIV positive people showed an HIV markers variation (increase, decrease or disappearance) in different periods of time (1-8 mo.). 5. Opportunistic infections were observed in 50% of symptomatic patients.(ABSTRACT TRUNCATED AT 250 WORDS)

In vitro estimation of pressure drop across tracheal tubes during high-frequency percussive ventilation.

Tracheal tubes (TT) are used in clinical practice to connect an artificial ventilator to the patient's airways. It is important to know the pressure used to overcome tube impedance to avoid lung injury. Although high-frequency percussive ventilation (HFPV) has been increasingly used, the mechanical behavior of TT under HFPV has not yet been described. Thus, we aimed at characterizing in vitro the pressure drop across TT (ΔPTT) by identifying the model that best fits the measured pressure-flow (P-V̇) relationships during HFPV under different working pressures (PWork), percussive frequencies and mechanical loads. Three simple models relating ΔPTT and flow (V̇) were tested. Model 1 is characterized by linear resistive [Rtube ⋅ V̇(t)] and inertial [I · V̈(t)] terms. Model 2 takes into consideration Rohrer's approach [K1· V̇(t) + K2 ⋅V̇(t)] and inertance [I ·V̈(t)]. In model 3 the pressure drop caused by friction is represented by the non-linear Blasius component [Kb· V̇(1.75)(t)] and the inertial term [I· V̈(t)]. Model 1 presented a significantly higher root mean square error of approximation than models 2 and 3, which were similar. Thus, model 1 was not as accurate as the latter, possibly due to turbulence. Model 3 presented the most robust resistance-related coefficient. Estimated inertances did not vary among the models using the same tube. In conclusion, in HFPV ΔPTT can be easily calculated by the physician using model 3.

Prediction bands and intervals for the scapulo-humeral coordination based on the Bootstrap and two Gaussian methods.

Quantitative motion analysis protocols have been developed to assess the coordination between scapula and humerus. However, the application of these protocols to test whether a subject's scapula resting position or pattern of coordination is "normal", is precluded by the unavailability of reference prediction intervals and bands, respectively. The aim of this study was to present such references for the "ISEO" protocol, by using the non-parametric Bootstrap approach and two parametric Gaussian methods (based on Student's T and Normal distributions). One hundred and eleven asymptomatic subjects were divided into three groups based on their age (18-30, 31-50, and 51-70). For each group, "monolateral" prediction bands and intervals were computed for the scapulo-humeral patterns and the scapula resting orientation, respectively. A fourth group included the 36 subjects (42 ± 13 year-old) for whom the scapulo-humeral coordination was measured bilaterally, and "differential" prediction bands and intervals were computed, which describe right-to-left side differences. Bootstrap and Gaussian methods were compared using cross-validation analyses, by evaluating the coverage probability in comparison to a 90% target. Results showed a mean coverage for Bootstrap from 86% to 90%, compared to 67-70% for parametric bands and 87-88% for parametric intervals. Bootstrap prediction bands showed a distinctive change in amplitude and mean pattern related to age, with an increase toward scapula retraction, lateral rotation and posterior tilt. In conclusion, Bootstrap ensures an optimal coverage and should be preferred over parametric methods. Moreover, the stratification of "monolateral" prediction bands and intervals by age appears relevant for the correct classification of patients.

Characterization of the mechanical behavior of intrapulmonary percussive ventilation.

A new device delivering intrapulmonary percussive ventilation (IPV), called Impulsator® (Percussionaire Corporation, Sandpoint, ID, USA), has recently been introduced in an effort to provide effective clearance and to promote homogeneity of ventilation in the lungs of patients with cystic fibrosis. In order to optimize the treatment based on its use, a better understanding of its functioning is still necessary. In fact, up to now, a complete characterization of this device has not been carried out, thus reducing its effective utilization in clinical practice. With the aim of overcoming this lack, in this study, data concerning flow and pressure delivered during in vitro IPV were acquired under different combinations of device settings and respiratory loads. Quantitative information was obtained about the physical variables administered by the device like percussive frequency, ratio of inspiratory to expiratory time, flow and pressure magnitudes and volume exchanged. The analysis of the data determined the relations among these variables and between them and the mechanical loads, laying the basis for an optimal clinical application of the device.

Ambulatory measurement of the scapulohumeral rhythm: intra- and inter-operator agreement of a protocol based on inertial and magnetic sensors.

To measure the scapulohumeral rhythm (SHR) in outpatient settings, the motion analysis protocol named ISEO (INAIL Shoulder and Elbow Outpatient protocol) was developed, based on inertial and magnetic sensors. To complete the sensor-to-segment calibration, ISEO requires the involvement of an operator for sensor placement and for positioning the patient's arm in a predefined posture. Since this can affect the measure, this study aimed at quantifying ISEO intra- and inter-operator agreement. Forty subjects were considered, together with two operators, A and B. Three measurement sessions were completed for each subject: two by A and one by B. In each session, the humerus and scapula rotations were measured during sagittal and scapular plane elevation movements. ISEO intra- and inter-operator agreement were assessed by computing, between sessions, the: (1) similarity of the scapulohumeral patterns through the Coefficient of Multiple Correlation (CMC(2)), both considering and excluding the difference of the initial value of the scapula rotations between two sessions (inter-session offset); (2) 95% Smallest Detectable Difference (SDD(95)) in scapula range of motion. Results for CMC(2) showed that the intra- and inter-operator agreement is acceptable (median≥0.85, lower-whisker ≥ 0.75) for most of the scapula rotations, independently from the movement and the inter-session offset. The only exception is the agreement for scapula protraction-retraction and for scapula medio-lateral rotation during abduction (inter-operator), which is acceptable only if the inter-session offset is removed. SDD(95) values ranged from 4.4° to 8.6° for the inter-operator and between 4.9° and 8.5° for the intra-operator agreement. In conclusion, ISEO presents a high intra- and inter-operator agreement, particularly with the scapula inter-session offset removed.

Inhibition of p85, the non-catalytic subunit of phosphatidylinositol 3-kinase, exerts potent antitumor activity in human breast cancer cells.

The phosphoinositide 3-kinases (PI3Ks) are heterodimers consisting of the catalytic subunit p110 and the regulatory subunit p85. The PI3K/Akt pathway is strongly deregulated in breast cancer (BC) representing one of the mechanisms of resistance to therapies. Therefore, the identification of inhibitors of PI3K components represents one of the main goals to produce therapeutic agents. Here, we evaluated the efficacy of a phosphopeptide 1257 (P-1257) that targeting p85 strongly inhibits PI3K activity. We tested the effects of P-1257 administration in vitro and in vivo using BC cells expressing different levels of ErbB-2 and resistant or responsive to Trastuzumab. We demonstrated that inhibition of p85 activity by P-1257 induces cell death and sensitizes JIMT-1 and KPL-4 ErbB-2-overexpressing BC cells to Trastuzumab treatment. It is noteworthy that P-1257 delivery in vivo by electroporation or liposomes significantly inhibits the proliferation of tumor cells engrafted at subcutaneous and visceral sites. Overall, our data indicate that the p85 subunit is a valid target for therapeutic approaches and suggest that the structure of the peptide used in our study could be utilized for the development of novel drugs to apply in combination with therapies that fail to cure BCs with high PI3K activity.

In vitro measurements of respiratory mechanics during HFPV using a mechanical lung model.

High-frequency percussive ventilation (HFPV) may be defined as flow-regulated time-cycled ventilation that creates controlled pressure and delivers a series of high-frequency subtidal volumes in combination with low-frequency breathing cycles. In recent years, the usefulness of HFPV has been clinically assessed as an alternative to conventional mechanical ventilation. In the clinical practice, HFPV is not an intuitive ventilatory modality and the absence of real-time delivered volume monitoring produces disaffection among the physicians. For this purpose, it would be useful to develop a monitor able to realize a complete online characterization of high-frequency percussive ventilators and to identify the best combination of their parameters according to the specific pathological situation. This paper describes an innovative acquisition and elaboration system based on the use of new generation pressure transducers presenting high sensitivity and fast response. Such a system is compact and inexpensive, and it allows the user to carry out a more correct online characterization of high-frequency percussive ventilators. This output allowed best real-time ventilatory setting, minimizing the potential baro-volutrauma hazard.

Use of the fractal dimension for the analysis of electroencephalographic time series.

Electroencephalogram (EEG) traces corresponding to different physiopathological conditions can be characterized by their fractal dimension, which is a measure of the signal complexity. Generally this dimension is evaluated in the phase space by means of the attractor dimension or other correlated parameters. Nevertheless, to obtain reliable values, long duration intervals are needed and consequently only long-term events can be analysed; also much calculation time is required. To analyse events of brief duration in real-time mode and to apply the results obtained directly in the time domain, thus providing an easier interpretation of fractal dimension behaviour, in this work we optimize and propose a new method for evaluating the fractal dimension. Moreover, we study the robustness of this evaluation in the presence of white or line noises and compare the results with those obtained with conventional spectral methods. The non-linear analysis carried out allows us to investigate relevant EEG events shorter than those detectable by means of other linear and non-linear techniques, thus achieving a better temporal resolution. An interesting link between the spectral distribution and the fractal dimension value is also pointed out.

Saccadic parameters for early identification of neuronopathic Gaucher's disease.

For a successful treatment of the neurological form of Gaucher's disease ,an early identification is necessary. Often an alteration of the horizontal saccadic eye movements constitutes the first sign of a central nervous system involvement. In order to obtain an early identification of the neuronopathic forms of the disease, often masked by the use of the enzyme replacement therapy, the classical saccadic characteristics (Latency, Amplitude vs. Duration and Amplitude vs. Peak Velocity relationships) are not usable. This work studies if some other parameters (Mean Velocity/Peak Velocity, Kurtosis, Skewness, Asymmetry), are able to describe the saccadic velocity profiles, could be considered to build an expert system able to reach the aim.