Our animal studies suggest that the basal ganglia provide an internal non-specific cue to trigger movement and imply that Parkinson's disease involves a deficiency in this cueing mechanism. Indeed parkinsonian patients typically rely upon external visual cues. To assess the effects of such non-specific cueing mechanisms on movement, we examined patients' utilization of a variety of auditory cues. Ten patients suffering from Parkinson's disease, and their matched controls, pressed buttons at a series of two-way choice points sequentially down a pathway, both when the latter remained illuminated throughout its length, and when it had to be followed from memory alone. In other experimental conditions, auditory cues were also provided, either contingent upon the previous response, at its initiation (a medium level of advance information) or at its completion (a low level of advance information), or as a series of regularly paced (non-contingent) auditory cues (from a metronome). In addition to error data, we recorded down time (DT, time to initiate each next response) and movement time (MT, time to execute each next response). However, both DT and MT measurements showed that parkinsonian patients were enormously disadvantaged by the absence of external cues. While contingent auditory cues were of some help, the performance of patients with Parkinson's disease was dramatically improved by the provision of non-contingent auditory information. Moreover, parkinsonian patients, unlike controls, were greatly affected by the length of individual sub-movements, especially in the absence of external cues. When the pathway to be followed remained illuminated, sub-movement length had little effect. We conclude that for well-learnt, predictable sequences the basal ganglia provide a non-specific internal cue that is necessary for switching between one movement and the next in a movement sequence, and also for development of preparatory activity for each sub-movement in the sequence.

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Tourette's syndrome and Huntington's disease have long been clinically associated with attentional deficits. In this study, we aimed to determine the nature and quantify the extent of such deficits. A technique was devised to ascertain the efficiency with which Tourette's syndrome and Huntington's disease patients could shift and direct attention away from naturally expected stimulus-response (S-R) linkages. This was done by varying the relationships formed between stimulus and response location. Attentional efficiency was indicated by relative speed of responding to relevant (congruent) and irrelevant (incongruent) stimuli, in a paradigm developed from the Simon effect. There were five conditions progressively increasing in complexity. The stimuli consisted of left and right pointing arrows and, in some cases, various conditionality manipulations were also employed, such that in the presence of a certain symbol (i.e. 'x') the nature of the response had to be reversed, whereas in the presence of an alternative symbol (i.e. '='), the response was compatible with the direction of the arrow. As predicted, Tourette's syndrome and Huntington's disease patients, regardless of medication or depression status and unlike controls, were particularly disadvantaged in responding to various conflicting S-R configurations. Tourette's syndrome and Huntington's disease patients may experience difficulties in making attentional shifts, or in inhibiting inappropriate responses; they may also be more susceptible (than controls) to the conflict that can arise when the spatial code formed for the stimulus is irrelevant for selecting the appropriate response. We conclude that our findings support the notion that cognitive deficits in Tourette's syndrome and Huntington's disease may stem from abnormalities of the major pathways interconnecting the basal ganglia and the frontal lobes.

In the last years the studies regarding the biocompatibility of dental materials investigate, in addition to the classic cytotoxic tests, the interactions between the materials and the host cells to better explain the causes of the adverse effects observed sometimes in the clinical practice. In the present study the ability of diurethane dimethacrylate (DUDMA) and 1,4‐butanediol dimethacrylate (BDDMA) methacrylic monomers present in dental composite resins to alter the functionality of peripheral blood monocytes (PBMs) and polymorphonucleate cells (PMNs) was examined. These cells are involve in the biological response to materials and in the host ability to respond to bacteria. The results obtained suggest that the examined methacrylates induce a relevant decrease of PBMs oxidative burst whereas the basal ROS production is only slightly decreased. In PMNs DUDMA induces a decrease of both basal and stimulated ROS production. BDDMA, on the contrary, it does not alter total oxidative burst in presence of stimulus while induces a statistically significant decrease of basal ROS production. Moreover this monomer alters the reaction kinetics of stimulated ROS production. The reported finding seems to indicate that this molecule could be able to stabilize PMNs in resting state and maximize their stimulated activity. Copyright © 2008 John Wiley & Sons, Ltd.

Tourette's syndrome is a chronic neurological disorder manifested by involuntary motor tics and vocalisations.

To identify the focus of impairment in the performance of sequential movements in Huntington's disease (HD) patients, the extent of their reliance on external advance information was examined. Twelve patients with HD and their age-matched controls performed a series of button-presses at sequential choice points along a response board. A sequential pathway was designated, and with each successive button press, advance visual information was systematically reduced to various extents in advance of each move. HD patients, like previously studied parkinsonian patients, were particularly disadvantaged with high levels of reduction in advance information, and as a consequence, both their initiation and execution of movements progressively slowed with each successive element in the response sequence. The pattern of results was not affected whether or not patients were taking neuroleptic medication, nor did performance on a variety of cognitive measures correlate with motor performance. Control subjects' performance, on the other hand, remained constant in terms of both initiation and execution with each of the three levels of reduction in advance information. We conclude that HD patients, like parkinsonian patients, who also suffer from a basal ganglia (BG) disorder, require external visual cues to sequence motor programs effectively. Our findings suggest that with HD there may be abnormalities in a central mechanism that controls switching between movement segments within an overall motor plan. The BG, which provide internal cues necessary for component sequencing, may be disrupted, thereby impairing the ability to use such internally generated cues to guide movement.

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Background:The aim of this study was to evaluate the changes in quality of life of patients after total knee arthroplasty and to assess the changes in physical activity by using a self-reported questionnaire and by counting the number of steps 3-6 months after post-operatively.Methods:Included were fifty two elderly women (age 72.6±65.9 years, mean±SD) with knee osteoarthritis undergoing primary knee arthroplasty. Health-related quality of life, physical activity, pain and function and the number of steps were assessed before, 3 and 6 months post-operatively. We used the Medical Outcomes Study Short Form (SF-36), the Physical Activity Scale for the Elderly (PASE) and the pedometer SW200 Digiwalker of Yamax.Results:Patients showed a significant improvement (p< 0.01, η2 =0.22) in health–related quality of life, particularly in physical function, (p<0 .001) body pain (p< 0.001) and vitality scale (p< 0.001) of SF-36 at 3 and 6 months after the procedure. Physical activity (PASE score) increased at 3 and 6 months after arthroplasty (p< 0.001, η2 =0.74), and the number of steps increased 6 months after, compared to the assessment that took place 3 months after operation (p< 0.001).Conclusions:Our results suggest that total knee arthroplasty leads to a gradual improvement in quality of life of elderly patients over the first 6 post-operative months.