901 resultados para ocular parameters


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This study aimed to assess application of ultrasound (US) combined with microbubbles (MB) to transfect the ciliary muscle of rat eyes. Reporter DNA plasmids encoding for Gaussia luciferase, β-galactosidase or the green fluorescent protein (GFP), alone or mixed with 50% Artison MB, were injected into the ciliary muscle, with or without US exposure (US set at 1 MHz, 2 W/cm(2), 50% duty cycle for 2 min). Luciferase activity was measured in ocular fluids at 7 and 30 days after sonoporation. At 1 week, the US+MB treatment showed a significant increase in luminescence compared with control eyes, injected with plasmid only, with or without MB (×2.6), and, reporter proteins were localized in the ciliary muscle by histochemical analysis. At 1 month, a significant decrease in luciferase activity was observed in all groups. A rise in lens and ciliary muscle temperature was measured during the procedure but did not result in any observable or microscopic damages at 1 and 8 days. The feasibility to transfer gene into the ciliary muscle by US and MB suggests that sonoporation may allow intraocular production of proteins for the treatment of inflammatory, angiogenic and/or degenerative retinal diseases.

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This research project investigated the use of image analysis to measure the air void parameters of concrete specimens produced under standard laboratory conditions. The results obtained from the image analysis technique were compared to results obtained from plastic air content tests, Danish air meter tests (also referred to as Air Void Analyzer tests), high-pressure air content tests on hardened concrete, and linear traverse tests (as per ASTM C-457). Hardened concrete specimens were sent to three different laboratories for the linear traverse tests. The samples that were circulated to the three labs consisted of specimens that needed different levels of surface preparation. The first set consisted of approximately 18 specimens that had been sectioned from a 4 in. by 4 in. by 18 in. (10 cm by 10 cm by 46 cm) beam using a saw equipped with a diamond blade. These specimens were subjected to the normal sample preparation techniques that were commonly employed by the three different labs (each lab practiced slightly different specimen preparation techniques). The second set of samples consisted of eight specimens that had been ground and polished at a single laboratory. The companion labs were only supposed to retouch the sample surfaces if they exhibited major flaws. In general, the study indicated that the image analysis test results for entrained air content exhibited good to strong correlation to the average values determined via the linear traverse technique. Specimens ground and polished in a single laboratory and then circulated to the other participating laboratories for the air content determinations exhibited the strongest correlation between the image analysis and linear traverse techniques (coefficient of determination, r-squared = 0.96, for n=8). Specimens ground and polished at each of the individual laboratories exhibited considerably more scatter (coefficient of determination, r-squared = 0.78, for n=16). The image analysis technique tended to produce low estimates of the specific surface of the voids when compared to the results from the linear traverse method. This caused the image analysis spacing factor calculations to produce larger values than those obtained from the linear traverse tests. The image analysis spacing factors were still successful at distinguishing between the frost-prone test specimens and the other (more durable) test specimens that were studied in this research project.

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This is the first report of 6 tasks to be performed in an effort to establish locally-based quality and performance criteria for asphalts, and ultimately to develop performance-related specifications based on simple physicochemical methods. Three of the most promising chemical methods (high performance liquid chromatography (HPLC), thermal analysis, and X-ray diffraction were selected to analyze 4 different types of samples. The results will indicate the fundamental asphalt property variables that directly affect the field performance in Iowa. The details of the materials and procedures employed are described, and the results of the tests are presented.

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Cyclosporine A is a poorly water-soluble, immunosuppressive drug used to treat a variety of ocular diseases. Its limited solubility makes challenging the development of a cyclosporine A-based eye drop for ocular topical application. Based on the prodrug strategy, the practically insoluble cyclosporine A was converted into a freely soluble prodrug. Such a water-soluble prodrug made it possible to develop water-based concentrated eye drops. The prodrug formulations were tested for their ex vivo permeation and in vivo distribution at three concentrations (equivalent to 0.05%, 0.50% and 2.00% w/v cyclosporine A). The ex vivo permeation experiments were performed on corneal and conjunctival epithelia. The in vivo distribution evaluated the total cyclosporine A present in the ocular structures as well as in serum, spleen and cervical lymphatic ganglions. Each prodrug formulation was compared to conventionally used cyclosporine A eye drops at an equivalent concentration. The experimental results showed that the tested eye drops behaved differently. The prodrug formulation was characterized by the following: i) preferential conjunctival penetration, ii) an interesting capacity to create large tissue deposits and iii) a lower risk of systemic complications and immunosuppression. The prodrug aqueous eye drop was demonstrated to be a patient-friendly option for the treatment of ocular diseases requiring high ocular levels of cyclosporine A, pushing the boundaries of the current therapeutic arsenal.

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Selostus: Ryhmäkoon ja varhaisen käsittelyn vaikutus tarhattujen sinikettujen hyvinvointiin

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Selostus: Ryhmäkoon ja käytössä olevan tilan vaikutus tarhattujen hopeakettupentujen hyvinvointiin

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In order to distinguish dysfunctional gait; clinicians require a measure of reference gait parameters for each population. This study provided normative values for widely used parameters in more than 1400 able-bodied adults over the age of 65. We also measured the foot clearance parameters (i.e., height of the foot above ground during swing phase) that are crucial to understand the complex relationship between gait and falls as well as obstacle negotiation strategies. We used a shoe-worn inertial sensor on each foot and previously validated algorithms to extract the gait parameters during 20 m walking trials in a corridor at a self-selected pace. We investigated the difference of the gait parameters between male and female participants by considering the effect of age and height factors. Besides; we examined the inter-relation of the clearance parameters with the gait speed. The sample size and breadth of gait parameters provided in this study offer a unique reference resource for the researchers.

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Purpose To evaluate the safety and efficacy of infliximab as an antifibrotic agent after experimental glaucoma filtration surgery in rabbits. Methods In a randomized, prospective, masked-observer study, 30 New Zealand Albino rabbits underwent glaucoma filtration surgery. The animals were allocated to receive either intraoperative application of infliximab (group A) or mitomycin C (MMC) at a concentration of 0.2mg/ml (group B) or balanced salt solution (BSS, control)(group C). Different infliximab doses, namely 1.0mg, 2.0mg, 3.0mg, 4.0mg, 5.0mg in 0.1ml were applied. Bleb survival and characteristics were evaluated over a 30day period. The animals were killed on postoperative day 15 and 30. Histology of the operated eyes was performed to evaluate and grade the amount of scarring in each group.Cellular density was evaluated in each case. Results Infliximab did not appear to improve the outcome of filtration surgery in this model of glaucoma filtration surgery.There was a significant decrease in cellular density in the MMC group compared to the control group (p=0.0352). There was neither a significant decrease in cellular density between the infliximab group and the control group nor between the infliximab group and the MMC group. Overall there was no difference in terms of fibrosis between the three different groups. There was slightly less inflammation in the infliximab group, but not significant. Conclusions In this study intraoperative application of infliximab does not appear to be superior to the application of MMC or a control with regard to bleb survival and fibrosis. This study however demonstrates that intraoperative application of MMC significantly reduces the cellular density of the filtration bleb.

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Despite the increase of animal and plant introductions worldwide and the strong augmentation of the reptile trade, few invasive snake populations have been studied. Dice snakes (Natrix tessellata) were introduced to the shores of Lake Geneva (Switzerland) in the early 1920s, and are now well established. This region of introduction was previously inhabited by Viperine snakes (N. maura). Ever since these two species have been under monitoring (which began in 1996) the Viperine snake population has shown drastic decline. We examine here the possibility of trophic competition by analysing diet composition, prey size and trophic niche overlap. Spatial distribution is also assessed in order to address the question of spatial competitive exclusion. We found very similar diets, and thus a high trophic niche overlap, indicating no partitioning of the trophic resource. No arguments in favour of spatial competitive exclusion were found. Our study suggests that trophic competition may occur between the two natricines and that it may give an explanation for the drastic decline of the Viperine snake in this area. Other pathways potentially playing a role in the exclusion of the Viperine snake are discussed.

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Purpose: To investigate the effect of the first and repeated intravitreal injections of ranibizumab (1.25mg; 0.05ml) on retrobulbar blood flow velocities in patients with wet age-related macular degeneration (AMD). Methods: This prospective non randomized study included twenty consecutive AMD patients. Time- averaged mean blood flow velocities (BFVs) in the central retinal, temporal posterior ciliary and ophthalmic arteries (CRA, TPCA and OA) were measured by ultrasound imaging before, 2 days and 3 weeks after the first injection of ranibizumab, then 6 months after supplemental monthly injections if required. At each visit, complete ophthalmological examination was performed, including best corrected visual acuity measurement according to ETDRS protocol and OCT. Results: In the treated eyes, ranibizumab injection was followed by a significant improvement in visual acuity (from 44.4 ± 21.7, to 50.9±25.9 (p<0.01) at month 6, and a decrease in mean central macular thickness from 377±115 to 267 ± 74 µm (p<0.001) at month 6. At day 2 mean BFVs decreased by 16% in the CRA and by 20% in TPCA (p<0.001, both), then remained stable. Mean BFVs did not change in OA at the day 2 but decreased at week 3 by 18% (p<0.001). Supplemental injections did not lead to additional effects at month 6. No effect was tabulated in the fellow eye. Conclusions: We report an early decrease in mean BFV in CRA and TPRA following intravitreal injections of ranibizumab corresponding to vasoconstrictive effect of this drug. Decrease in mean BFV in all retrobulbar arteries from the week 3 suggests that ranibizumab proceeds to a local and regional vasoconstrictive and antiangiogenic effects after local diffusion. Thus, ranibizumab could induce an actual hypoperfusion of the treated eye which could correspond to a vascular side effect.

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RESUME : Les dermatophytes sont les agents infectieux les plus fréquents responsables de la plupart des mycoses superficielles chez les humains et chez les animaux. Ces infections, dermatophytoses, également appelées tineas ou teignes, sont fréquentes et causent des problèmes de santé publique au niveau mondial. La capacité d'envahir et de progresser au sein des structures kératinisées est probablement liée à la sécrétion de différentes enzymes kératinolytiques, qui sont considérées comme la principale caractéristique liée à la pathogénicité de ces champignons. L'objectif de ma thèse a été premièrement de progresser dans l'identification et la caractérisation des nouvelles protéines sécrétées, afin de mieux comprendre a) la capacité globale des dermatophytes à envahir les structures kératinisées, et b) les différences dans la virulence et la spécificité d'hôte que présentent les espèces étudiées .Pour progresser dans l'identification et la caractérisation de ces nouvelles protéines, les secretomes de six espèces de dermatophytes (Trichophyton rubrum, Trichophyton violaceum, Trichophyton soudanense, Trichophyton equinum, Arthroderma vanbreuseghemii et Trichophyton tonsurans) ont été étudiés. Bien qu'il y ait un niveau globalement élevé de similitude entre les protéases sécrétées, les différentes espèces de dermatophytes sécrètent des profiles protéiques distincts lorsqu'elles sont cultivées dans les mêmes conditions de culture, et donc une signature spécifique a pu être associé à chaque espèce. Ces profiles ont été un outil avantageux pour identifier et cartographier les protéines orthologues aux six espèces et ont aussi permit la discrimination d'espèces très proches comme T. tonsurans et T. equinum qui ne peuvent pas être différenciées par l'ADN ribosomal. Ce travail également présente ce que l'on croit être la première identification global des protéines sécrétées par les dermatophytes dans des conditions de culture que incitent l'activité protéolytique extracellulaire. Ce catalogue de protéines, comprenant des endo- and exo- proteases, autres hydrolases, oxydoreductases et des protéines avec fonction inconnue, représente probablement le spectre d'enzymes qui permettent la dégradation des tissus kératinisés en composés qui peuvent être assimilés par le champignon. Les résultats suggèrent qu'un changement écologique pourrait être associé à une expression différentielle des gènes codant les protéines sécrétées, en particulier, les protéases, plutôt qu'à des divergences génétiques au niveau des gènes codant les protéines orthologues. Une sécrétion différentielle des protéines par les dermatophytes pourrait également être responsable de la variabilité inflammatoire qui causent ces agents infectieux chez les différents hôtes. Par conséquent, les protéines identifiées ici sont également importantes pour faire la lumière sur la réponse immunitaire de l'hôte au cours du processus infectieux. SUMMARY : Dermatophytes are the most common infectious agents responsible for superficial mycosis in humans and animals. Dermatophytoses, also called tineas or ringworm, are frequent and cause public health problems worldwide. The secretion of different keratinolytic enzymes is believed to be a key pathogenicity-related characteristic of these fungi. The aim of this work was first to progress in the identification and characterization of novel secreted proteins, in order to better understand a) the overall capability of dermatophytes to invade keratinised structures, and b) differences in virulence and host-specificity of the investigated species. To progress in the identification and characterization of novel proteins, the secretomes from Trichophyton rubrum, Trichophyton violaceum, Trichophyton soudanense, Trichophyton equinum, Arthroderma vanbreuseghemii and Trichophyton tonsurans were studied. Although there is a high global level of similarity among the secreted proteases, different dermatophyte species produce distinct patterns of proteins when grown in the same culture medium, and so a specific signature could be associated to each species. These patterns were useful to identify and map orthologous proteins among the six species, as well as to discriminate the closely related species T. tonsurans and T. equinum, which cannot be differentiated by ribosomal DNA. This work also presents the first in-depth identification of the major proteins secreted by dermatophytes growing under conditions promoting extracellular proteolytic activity. This catalogue of proteins, which include several endo- and exo- proteases, other hydrolases, oxydoreductases, and proteins of unknown function, probably represents the spectrum of enzymes that allow the degradation of keratinized tissues into compounds which can be assimilated by the fungus. The results suggest that ecological switching could be related to a differential expression of genes encoding secreted proteins, particularly, proteases, rather than genetic divergences of the genes encoding orthologous proteins. Differential secretion of proteins by Dermatophyte species could also be responsible for the variable inflammation caused by the infectious agent within the host. Therefore, the proteins here identified are also important to shed light into the immune response of the host during the infection process.

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Introduction: Ankle arthrodesis (AD) and total ankle replacement (TAR) are typical treatments for ankle osteoarthritis (AO). Despite clinical interest, there is a lack of their outcome evaluation using objective criteria. Gait analysis and plantar pressure assessment are appropriate to detect pathologies in orthopaedics but they are mostly used in lab with few gait cycles. In this study, we propose an ambulatory device based on inertial and plantar pressure sensors to compare the gait during long-distance trials between healthy subjects (H) and patients with AO or treated by AD and TAR. Methods: Our study included four groups: 11 patients with AO, 9 treated by TAR, 7 treated by AD and 6 control subjects. An ambulatory system (Physilog®, CH) was used for gait analysis; plantar pressure measurements were done using a portable insole (Pedar®-X, DE). The subjects were asked to walk 50 meters in two trials. Mean value and coefficient of variation of spatio-temporal gait parameters were calculated for each trial. Pressure distribution was analyzed in ten subregions of foot. All parameters were compared among the four groups using multi-level model-based statistical analysis. Results: Significant difference (p <0.05) with control was noticed for AO patients in maximum force in medial hindfoot and forefoot and in central forefoot. These differences were no longer significant in TAR and AD groups. Cadence and speed of all pathologic groups showed significant difference with control. Both treatments showed a significant improvement in double support and stance. TAR decreased variability in speed, stride length and knee ROM. Conclusions: In spite of a small sample size, this study showed that ankle function after AO treatments can be evaluated objectively based on plantar pressure and spatio-temporal gait parameters measured during unconstrained walking outside the lab. The combination of these two ambulatory techniques provides a promising way to evaluate foot function in clinics.

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The relation between the low-energy constants appearing in the effective field theory description of the Lambda N -> NN transition potential and the parameters of the one-meson-exchange model previously developed is obtained. We extract the relative importance of the different exchange mechanisms included in the meson picture by means of a comparison to the corresponding operational structures appearing in the effective approach. The ability of this procedure to obtain the weak baryon-baryon-meson couplings for a possible scalar exchange is also discussed.