30 research outputs found
Human oestriasis acquired in Florence and review on human myiasis in Italy
Myiases-causing flies are widely observed in tropical countries, whereas in Italy, a temperate country, their epidemiology and clinical presentation are poorly known. We report three cases of human conjunctival myiasis recently observed at our hospital, and the results of a review of the literature on human myiasis in Italy. In August 2012, a case of Oestrus ovis conjunctival myiasis acquired in the city centre of Florence, Italy was diagnosed at our hospital. In the early fall of 2013, two additional cases, acquired in the neighbouring areas, occurred. The review of literature showed that, up to the middle of 1990s, myiasis in Italy was mainly an occupational disease of shepherds, caused by O. ovis. Recently, cases of travel acquired furuncular myiasis emerged, together with “opportunistic” autochthonous cases of wound myiasis in patients with underlying health conditions. Considering the causative agents of human of myiasis in Italy, among the 703 autochthonous cases reported, 98.1 % were caused by O. ovis, while among the 42 imported cases described, 59.5 % were due to Cordylobia spp. and 40.5 % to Dermatobia hominis. Our findings suggest that O. ovis conjunctival myiasis may still be observed in urban setting in Italy. Health care providers should know and implement the basic rules of entomoprophylaxis for myiasis in the facilities where they are working and use these indications to educate patients and care givers in both pretravel care and geriatric outpatient settings. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s00436-014-3906-9) contains supplementary material, which is available to authorized users
Misure di segnali fluorescenti per l'analisi in microscopia dell'espressione genica in biologia sintetica
Protocolli e metodologie di caratterizzazione di un sistema di misura di segnali fluorescenti in microscopia ottic
Human oestriasis acquired in Florence and review on human myiasis in Italy
Myiases-causing flies are widely observed in tropical countries, whereas in Italy, a temperate country, their epidemiology and clinical presentation are poorly known. We report three cases of human conjunctival myiasis recently observed at our hospital, and the results of a review of the literature on human myiasis in Italy. In August 2012, a case of Oestrus ovis conjunctival myiasis acquired in the city centre of Florence, Italy was diagnosed at our hospital. In the early fall of 2013, two additional cases, acquired in the neighbouring areas, occurred. The review of literature showed that, up to the middle of 1990s, myiasis in Italy was mainly an occupational disease of shepherds, caused by O. ovis. Recently, cases of travel acquired furuncular myiasis emerged, together with "opportunistic" autochthonous cases of wound myiasis in patients with underlying health conditions. Considering the causative agents of human of myiasis in Italy, among the 703 autochthonous cases reported, 98.1% were caused by O. ovis, while among the 42 imported cases described, 59.5% were due to Cordylobia spp. and 40.5% to Dermatobia hominis. Our findings suggest that O. ovis conjunctival myiasis may still be observed in urban setting in Italy. Health care providers should know and implement the basic rules of entomoprophylaxis for myiasis in the facilities where they are working and use these indications to educate patients and care givers in both pretravel care and geriatric outpatient settings
ULTRASOUND IN VITRECTOMY
Purpose: To study a prototype of an ultrasound-based vitrector, and to try to understand the physical phenomena underlying this new technology.
Methods: We tested the ultrasound-based vitrector prototype (UV) (ultrasonically-driven handpiece obtained from a modified version of the Alcon CONSTELLATION Vision System [Alcon]) using an automatic experimental setup. Balanced saline solution (BSS) and vitreous (from fresh postmortem enucleated porcine eyes) flow rates were analyzed using three different tips.
Results: In general, BSS solution flow rates increased with increasing aspiration levels and decreased when we used % US power. Vitreous flow rates were influenced by aspiration levels, % US power, and ultrasound-related phenomena: cavitation phenomenon and “jet streaming.”
Conclusion: Ultrasound-based vitrectomy may represent an important alternative to traditional vitrectomy. Such a tool, capable of liquefying and excising the vitreous body using ultrasound, could overcome all the limits of the guillotine-based technique (GV). Knowledge of the physical phenomena underlying ultrasound-based technology is a necessary prerequisite for further development of this new technology
Rotatable small permanent magnet array for ultra-low field nuclear magnetic resonance instrumentation: a concept study
Object We studied the feasibility of generating the variable magnetic fields required for ultra-low field nuclear magnetic resonance relaxometry with dynamically adjustable permanent magnets. Our motivation was to substitute traditional electromagnets by distributed permanent magnets, increasing system portability. Materials and Methods The finite element method (COMSOL® ) was employed for the numerical study of a small permanent magnet array to calculate achievable magnetic field strength, homogeneity, switching time and magnetic forces. A manually operated prototype was simulated and constructed to validate the numerical approach and to verify the generated magnetic field. Results A concentric small permanent magnet array can be used to generate strong sample prepolarisation and variable measurement fields for ultra-low field relaxometry via simple prescribed magnet rotations. Using the array, it is possible to achieve a pre-polarisation field strength above 100 mT and variable measurement fields ranging from 20-50 μT with 200 ppm absolute field homogeneity within a field-of-view of 5 x 5 x 5 cubic centimetres. Conclusions A dynamic small permanent magnet array can generate multiple highly homogeneous magnetic fields required in ultra-low field nuclear magnetic resonance (NMR) and magnetic resonance imaging (MRI) instruments. This design can significantly reduce the volume and energy requirements of traditional systems based on electromagnets, improving portability considerably
Single-unit activity of the anterior Globus pallidus internus in Tourette patients and posterior Globus pallidus internus in dystonic patients
Our goal was to provide a detailed analysis of neurons' electrophysiological activity recorded in sub-territories of Globus pallidus internus (GPi) used as Deep Brain Stimulation (DBS) targets for these clinical conditions to potentially assist electrode targeting.We used intra-operative microelectrode recording during stereotactic neurosurgery to guide implantation of DBS lead.Units in the medial anterior part of GPi of 7 Tourette's syndrome patients under general anesthesia were firing at mean and median rate of 32.1 and 21 Hz respectively (n = 101), with 45% of spikes fired during bursts and 21.3 bursts per minute. In the latero-posterior part of GPi of 7 dystonic patients under local anesthesia the mean and median activity were 46.1 and 30.6 Hz respectively (n = 27), and a mean of 21.7 bursts per minute was observed, with 30% of all spikes occurring during these bursts.Units activity pattern - slow-regular, fast-irregular or fast-regular were present in different proportions between the two targets.The electrophysiological characteristics of the medial-anterior part of GPi and its latero-posterior portion can be used to assist DBS electrode targeting and also support the refinement of pathophysiological models of Tourette's syndrome and Dystonia
2D cross-sectional plots of pre-polarisation field B<sub>p</sub> along the x-axis (switched on).
<p>For array <i>A</i> with constant fill factor, curve 1 (solid line) corresponds to 12 magnets, curve 2 (dashed line) to 16 and curve 3 (dash-dotted line) to 24 magnets. For array <i>A</i> with constant magnet dimensions (L = 70 cm, d<sub>m</sub> = 2.16 cm), curve 4 (dash-dotted line) corresponds to 24 magnets, curve 5 (dashed line) to 16 magnets and curve 6 (solid line) to 12 magnets. (a) In array A with constant fill factor 0.75, the field strength within the field of view (FOV) decreases with the number of magnets, since magnet volume and surface area increase. (b) For array <i>A</i> with constant magnet size, the field strength decreases with decreasing numbers of magnets. (c) Within the FOV the field inhomogeneity decreases slightly with decreasing numbers of magnets for both constant fill factor (c) and magnet size (d). In all cases, the field inhomogeneity within the FOV was well below 0.02% (200 ppm)</p
Comparison of simulated and measured magnetic fields generated by the SPMA prototype.
<p>Comparison of simulated and measured magnetic fields generated by the SPMA prototype.</p
Rotatable Small Permanent Magnet Array for Ultra-Low Field Nuclear Magnetic Resonance Instrumentation: A Concept Study - Fig 13
<p><b>Comparison of (a) B</b><sub><b>p</b></sub><b>and (b) B</b><sub><b>m</b></sub><b>generated by a SPMA prototype with results of numerical simulation.</b> (a) The measured magnitude of <b>B</b><sub><b>p</b></sub> (yellow) shows an offset of 200 μT compared to the simulated value (blue), due to a higher remanent magnetisation than specifications provided by the manufacturer. (b) Arrow plot of <b>B</b><sub><b>m</b></sub> for two angular positions of arrays <i>E</i> and <i>F</i>. Dashed lines represent the measured field and continuous lines represent the simulated field for α = 0<sup>0</sup> and α = 10<sup>0</sup>. The mismatch between simulation and measurement is produced predominantly by the leftover field produced by array <i>D</i> in the tangential configuration.</p