179 resultados para Eye-hand coordination
Resumo:
The optimization of the extremity dosimetry of medical staff in nuclear medicine was the aim of the Work Package 4 (WP4) of the ORAMED project, a Collaborative Project (2008-2011) supported by the European Commission within its 7th Framework Programme. Hand doses and dose distributions across the hands of medical staff working in nuclear medicine departments were evaluated through an extensive measurement program involving 32 hospitals in Europe and 139 monitored workers. The study included the most frequently used radionuclides, (99m)Tc- and (18)F-labelled radiopharmaceuticals for diagnostic and (90)Y-labelled Zevalin (R) and DOTATOC for therapy. Furthermore, Monte Carlo simulations were performed in different predefined scenarios to evaluate separately the efficacy of different radiation protection measures by comparing hand dose distributions according to various parameters. The present work gives recommendations based on results obtained with both measurements and simulations. This results in nine practical recommendations regarding the positioning of the dosemeters for an appropriate skin dose monitoring and the best protection means to reduce the personnel exposure.
Resumo:
The case of a professional tennis player presenting exercise-induced hand pain with late appearance of digital blanching is reported. A bilateral hypothenar hammer syndrome and stenosis of the common palmar digital arteries close to the head of the metacarpals where the racket handle exerts its maximal force was observed with arteriography. As the patient decided to stop tennis practice, the condition improved without any medication. Six months after stopping tennis he was symptom free. Three conclusions can be drawn from this case report: 1) arteries of both hands can be injured by intense tennis practice, 2) pain in the dominant hand during tennis practice can be due to arterial insufficiency even in the absence of digital blanching which is a sign of severity, 3) hypothenar hammer syndrome is the main cause but stenosis of the common palmar digital arteries can possibly contribute to the ischemic phenomenon. Early recognition is important to avoid ineffective treatment and permanent symptoms. Therefore, we recommend an arterial examination in tennis players suffering from exercise-induced hand pain even in the absence of digital blanching which can be only a late manifestation.
Resumo:
BACKGROUND: The purpose of this study is to describe the experience of Jules Gonin Eye Hospital on the long-term outcome of anti-TNF-alpha therapy in chronic non-infectious uveitis. PATIENTS AND METHODS: We identified and followed those patients with chronic non-infectious uveitis who received systemic anti-TNF-alpha therapy. Anti-TNF-alpha therapy was administered when no response had been obtained with classical immunosuppressive therapies or in the presence of severe rheumatoid disease. RESULTS: Fifteen patients (28 eyes), 7 male and 8 female (mean age, 43 years; range: 7 to 70 years) were identified. Diagnoses included HLA-B27-associated anterior uveitis (n = 4), sarcoidosis (n = 2), juvenile idiopathic arthritis (n = 2), idiopathic retinal vasculitis with uveitis (n = 2), pars planitis (n = 2), Adamantiades-Behçet disease (n = 1), birdshot retinochoroidopathy (n = 1), and Crohn's disease (n = 1). Mean duration of ocular disease was 8 years (range: 1 to 29 years). Treatment with infliximab (n = 11), etanercept (n = 2), or adalimumab (n = 2) was initiated. One patient with etanercept was switched to infliximab due to lack of clinical response. Clinical and angiographic regression of uveitis was observed within the first two months of therapy in all patients, and was maintained throughout the entire follow-up period (mean 18 months; range: 3 - 72 months). Recurrence was observed in 3 patients, and resolved after adjustment of therapy. Adverse events were recorded in only one patient (arterial hypotension). CONCLUSIONS: In this series of patients with chronic non-infectious uveitis, anti-TNF-alpha therapy was effective and safe. Further clinical studies are needed to determine an adequate duration of therapy.
Resumo:
Ultraviolet (UV) radiation potentially damages the skin, the immune system, and structures of the eye. A useful UV sun protection for the skin has been established. Since a remarkable body of evidence shows an association between UV radiation and damage to structures of the eye, eye protection is important, but a reliable and practical tool to assess and compare the UV-protective properties of lenses has been lacking. Among the general lay public, misconceptions on eye-sun protection have been identified. For example, sun protection is mainly ascribed to sunglasses, but less so to clear lenses. Skin malignancies in the periorbital region are frequent, but usual topical skin protection does not include the lids. Recent research utilized exact dosimetry and demonstrated relevant differences in UV burden to the eye and skin at a given ambient irradiation. Chronic UV effects on the cornea and lens are cumulative, so effective UV protection of the eyes is important for all age groups and should be used systematically. Protection of children's eyes is especially important, because UV transmittance is higher at a very young age, allowing higher levels of UV radiation to reach the crystalline lens and even the retina. Sunglasses as well as clear lenses (plano and prescription) effectively reduce transmittance of UV radiation. However, an important share of the UV burden to the eye is explained by back reflection of radiation from lenses to the eye. UV radiation incident from an angle of 135°-150° behind a lens wearer is reflected from the back side of lenses. The usual antireflective coatings considerably increase reflection of UV radiation. To provide reliable labeling of the protective potential of lenses, an eye-sun protection factor (E-SPF®) has been developed. It integrates UV transmission as well as UV reflectance of lenses. The E-SPF® compares well with established skin-sun protection factors and provides clear messages to eye health care providers and to lay consumers.
Resumo:
The main aim of the Work Package 1 (WP1) of the ORAMED project, Collaborative Project (2008-2011), supported by the European Commission within its 7th Framework Programme, was to obtain a set of standardized data on extremity and eye lens doses for staff in interventional radiology and cardiology (IR/IC) workplaces and to recommend a series of guidelines on radiation protection in order to both guarantee and optimize staff protection. Within the project, coordinated measurements were performed in 34 hospitals in 6 European countries. Furthermore, simulations of the most representative workplaces in IR and IC were performed to determine the main parameters that influence the extremity and eye lens doses. The work presented in this paper shows the recommendations that were formulated by the results obtained from both measurements and simulations. The presented guidelines are directed to operators, assistant personnel, radiation protection officers and medical physics experts. They concern radiation protection issues, such as the use of room protective equipment, as well as the positioning of the extremity and eye lens dosemeters for routine monitoring.
Resumo:
Take-off, the most important phase in ski jumping, has been primarily studied in terms of spatio-temporal parameters; little is known about its motor control aspects. This study aims to assess the inter-segment coordination of the shank-thigh and thigh-sacrum pairs using the continuous relative phase (CRP). In total 87 jumps were recorded from 33 athletes with an inertial sensor-based system. The CRP curves indicated that the thighs lead the shanks during the first part of take-off extension and that the shanks rotated faster at the take-off extension end. The thighs and sacrum first rotated synchronously, with the sacrum then taking lead, with finally the thighs rotating faster. Five characteristic features were extracted from the CRP and their relationship with jump length was tested. Three features of the shank-thigh pair and one of the thigh-sacrum pair reported a significant association with jump length. It was observed that athletes who achieved longer jumps had their thighs leading their shanks during a longer time, with these athletes also having a more symmetric movement between thighs and sacrum. This study shows that inter-segment coordination during the take-off extension is related to performance and further studies are necessary to contrast its importance with other ski jumping aspects.
NPAS2 as a transcriptional regulator of non-rapid eye movement sleep: genotype and sex interactions.
Resumo:
Because the transcription factor neuronal Per-Arnt-Sim-type signal-sensor protein-domain protein 2 (NPAS2) acts both as a sensor and an effector of intracellular energy balance, and because sleep is thought to correct an energy imbalance incurred during waking, we examined NPAS2's role in sleep homeostasis using npas2 knockout (npas2-/-) mice. We found that, under conditions of increased sleep need, i.e., at the end of the active period or after sleep deprivation (SD), NPAS2 allows for sleep to occur at times when mice are normally awake. Lack of npas2 affected electroencephalogram activity of thalamocortical origin; during non-rapid eye movement sleep (NREMS), activity in the spindle range (10-15 Hz) was reduced, and within the delta range (1-4 Hz), activity shifted toward faster frequencies. In addition, the increase in the cortical expression of the NPAS2 target gene period2 (per2) after SD was attenuated in npas2-/- mice. This implies that NPAS2 importantly contributes to the previously documented wake-dependent increase in cortical per2 expression. The data also revealed numerous sex differences in sleep; in females, sleep need accumulated at a slower rate, and REMS loss was not recovered after SD. In contrast, the rebound in NREMS time after SD was compromised only in npas2-/- males. We conclude that NPAS2 plays a role in sleep homeostasis, most likely at the level of the thalamus and cortex, where NPAS2 is abundantly expressed.
Resumo:
BACKGROUND: In May 2010, Switzerland introduced a heterogeneous smoking ban in the hospitality sector. While the law leaves room for exceptions in some cantons, it is comprehensive in others. This longitudinal study uses different measurement methods to examine airborne nicotine levels in hospitality venues and the level of personal exposure of non-smoking hospitality workers before and after implementation of the law. METHODS: Personal exposure to second hand smoke (SHS) was measured by three different methods. We compared a passive sampler called MoNIC (Monitor of NICotine) badge, to salivary cotinine and nicotine concentration as well as questionnaire data. Badges allowed the number of passively smoked cigarettes to be estimated. They were placed at the venues as well as distributed to the participants for personal measurements. To assess personal exposure at work, a time-weighted average of the workplace badge measurements was calculated. RESULTS: Prior to the ban, smoke-exposed hospitality venues yielded a mean badge value of 4.48 (95%-CI: 3.7 to 5.25; n = 214) cigarette equivalents/day. At follow-up, measurements in venues that had implemented a smoking ban significantly declined to an average of 0.31 (0.17 to 0.45; n = 37) (p = 0.001). Personal badge measurements also significantly decreased from an average of 2.18 (1.31-3.05 n = 53) to 0.25 (0.13-0.36; n = 41) (p = 0.001). Spearman rank correlations between badge exposure measures and salivary measures were small to moderate (0.3 at maximum). CONCLUSIONS: Nicotine levels significantly decreased in all types of hospitality venues after implementation of the smoking ban. In-depth analyses demonstrated that a time-weighted average of the workplace badge measurements represented typical personal SHS exposure at work more reliably than personal exposure measures such as salivary cotinine and nicotine.
Resumo:
The serine-threonine kinase LKB1 regulates cell polarity from Caenorhabditis elegans to man. Loss of lkb1 leads to a cancer predisposition, known as Peutz-Jeghers Syndrome. Biochemical analysis indicates that LKB1 can phosphorylate and activate a family of AMPK- like kinases, however, the precise contribution of these kinases to the establishment and maintenance of cell polarity is still unclear. Recent studies propose that LKB1 acts primarily through the AMP kinase to establish and/or maintain cell polarity. To determine whether this simple model of how LKB1 regulates cell polarity has relevance to complex tissues, we examined lkb1 mutants in the Drosophila eye. We show that adherens junctions expand and apical, junctional, and basolateral domains mix in lkb1 mutants. Surprisingly, we find LKB1 does not act primarily through AMPK to regulate cell polarity in the retina. Unlike lkb1 mutants, ampk retinas do not show elongated rhabdomeres or expansion of apical and junctional markers into the basolateral domain. In addition, nutrient deprivation does not reveal a more dramatic polarity phenotype in lkb1 photoreceptors. These data suggest that AMPK is not the primary target of LKB1 during eye development. Instead, we find that a number of other AMPK-like kinase, such as SIK, NUAK, Par-1, KP78a, and KP78b show phenotypes similar to weak lkb1 loss of function in the eye. These data suggest that in complex tissues, LKB1 acts on an array of targets to regulate cell polarity.