909 resultados para DRY EYE
Resumo:
ATP-binding cassette (ABC) transporters play a pivotal role in human physiology, and mutations in these genes often result in severe hereditary diseases. ABC transporters are expressed in the bovine mammary gland but their physiological role in this organ remains elusive. Based on findings in the context of human disorders we speculated that candidate ABC transporters are implicated in lipid and cholesterol transport in the mammary gland. Therefore we investigated the expression pattern of selected genes that are associated with sterol transport in lactating and nonlactating mammary glands of dairy cows. mRNA levels from mammary gland biopsies taken during lactation and in the first and second week of the dry period were analysed using quantitative PCR. Five ABC transporter genes, namely ABCA1, ABCA7, ABCG1, ABCG2 and ABCG5, their regulating genes LXRalpha, PPARgamma, SREBP1 and the milk proteins lactoferrin and alpha-lactalbumin were assessed. A significantly enhanced expression in the dry period was observed for ABCA1 while a significant decrease of expression in this period was detected for ABCA7, ABCG2, SREBP1 and alpha-lactalbumin. ABCG1, ABCG5, LXRalpha, PPARgamma and lactoferrin expression was not altered between lactation and dry period. These results indicate that candidate ABC transporters involved in lipid and cholesterol transport show differential mRNA expression between lactation and the dry period. This may be due to physiological changes in the mammary gland such as immigration of macrophages or the accumulation of fat due to the loss of liquid in the involuting mammary gland. The current mRNA expression analysis of transporters in the mammary gland is the prerequisite for elucidating novel molecular mechanisms underlying cholesterol and lipid transfer into milk.
Resumo:
A modified Astra type multistage liquid impinger (MSLI) with integrated bronchial cell monolayers was used to study deposition and subsequent drug absorption on in vitro models of the human airway epithelial barrier. Inverted cell culture of Calu-3 cells on the bottom side of cell culture filter inserts was integrated into a compendial MSLI. Upside down cultivation did not impair the barrier function, morphology and viability of Calu-3 cells. Size selective deposition with subsequent absorption was studied for three different commercially available dry powder formulations of salbutamol sulphate and budesonide. After deposition without size separation the absorption rates from the aerosol formulations differed but correlated with the size of the carrier lactose particles. However, after deposition in the MSLI, simulating relevant impaction and causing the separation of small drug crystals from the carrier lactose, the absorption rates of the three formulations were identical, confirming the bioequivalence of the three formulations.
Resumo:
The objective of this study is to gain a quantitative understanding of land use and land cover change (LULCC) that have occurred in a rural Nicaraguan municipality by analyzing Landsat 5 Thematic Mapper (TM) images. By comparing the potential extent of tropical dry forest (TDF) with Landsat 5 TM images, this study analyzes the loss of this forest type on a local level for the municipality of San Juan de Cinco Pinos (63.5 km2) in the Department of Chinandega. Change detection analysis shows where and how land use has changed from 1985 to the present. From 1985 to 2011, nearly 15% of the TDF in San Juan de Cinco Pinos was converted to other land uses. Of the 1434.2 ha of TDF that was present in 1985, 1223.64 ha remained in 2011. The deforestation is primarily a result of agricultural expansion and fuelwood extraction. If current rates of TDF deforestation continue, the municipality faces the prospect of losing its forest cover within the next few decades.
Resumo:
The aim of this study was to investigate the effect of single-pulse transcranial magnetic stimulation on the triggering of saccades. The right frontal eye field was stimulated during modified gap and overlap paradigms with flashed presentation of the lateral visual target of 80 ms. In order to examine possible facilitating or inhibitory effects on saccade triggering, three different time intervals of stimulation were chosen, i.e. simultaneously with onset of the target, during the presentation and after target end. Stimulation applied simultaneously with target onset significantly decreased the latency of contralateral saccades in the gap but not in the overlap paradigm. Stimulation after target end significantly increased saccade latency for both sides in the gap paradigm and for the contralateral side in the overlap paradigm. Stimulation during presentation had no effect in either paradigm. The results show that, depending on the time interval and the paradigm tested, a facilitation or inhibition of saccade triggering can be achieved. The results are discussed in a context of two probable transcranial magnetic stimulation effects, a direct interference with the frontal eye field on the one hand and a remote interference with the superior colliculus on the other hand.
Resumo:
When sight-reading a piece of music the eyes constantly scan the score slightly ahead of music execution. This separation between reading and acting is commonly termed eye-hand span and can be expressed in two ways: as anticipation in notes or in time. Previous research, predominantly in piano players, found skill-dependent differences of eye-hand span. To date no study has explored visual anticipation in violinists. The present study investigated how structural properties of a piece of music affect the eye-hand span in a group of violinists. To this end eye movements and bow reversals were recorded synchronously while musicians sight-read a piece of music. The results suggest that structural differences of the score are reflected in the eye-hand span in a way similar to skill level. Specifically, the piece with higher complexity was associated with lower anticipation in notes, longer fixation duration and a tendency for more regressive fixations. Anticipation in time, however, remained the same (approximately 1 s) independently of the score played but was correlated with playing tempo. We conclude that the eye-hand span is not only influenced by the experience of the musician, but also by the structure of the score to be played.
Resumo:
Potential gold mines lie high among the rugged peaks of the Tobacco Root Mountains of southwestern Montana. This is a region where little geologic work has been done, though extensive mine operations have been carried on, and valuable ore has been shipped.
Resumo:
Despite widespread use of species-area relationships (SARs), dispute remains over the most representative SAR model. Using data of small-scale SARs of Estonian dry grassland communities, we address three questions: (1) Which model describes these SARs best when known artifacts are excluded? (2) How do deviating sampling procedures (marginal instead of central position of the smaller plots in relation to the largest plot; single values instead of average values; randomly located subplots instead of nested subplots) influence the properties of the SARs? (3) Are those effects likely to bias the selection of the best model? Our general dataset consisted of 16 series of nested-plots (1 cm(2)-100 m(2), any-part system), each of which comprised five series of subplots located in the four corners and the centre of the 100-m(2) plot. Data for the three pairs of compared sampling designs were generated from this dataset by subsampling. Five function types (power, quadratic power, logarithmic, Michaelis-Menten, Lomolino) were fitted with non-linear regression. In some of the communities, we found extremely high species densities (including bryophytes and lichens), namely up to eight species in 1 cm(2) and up to 140 species in 100 m(2), which appear to be the highest documented values on these scales. For SARs constructed from nested-plot average-value data, the regular power function generally was the best model, closely followed by the quadratic power function, while the logarithmic and Michaelis-Menten functions performed poorly throughout. However, the relative fit of the latter two models increased significantly relative to the respective best model when the single-value or random-sampling method was applied, however, the power function normally remained far superior. These results confirm the hypothesis that both single-value and random-sampling approaches cause artifacts by increasing stochasticity in the data, which can lead to the selection of inappropriate models.
Resumo:
BACKGROUND AND PURPOSE: : Proton radiation has been used for the treatment of uveal melanoma since 1975, but few studies have been conducted to assess its efficacy and safety. This paper aims to systematically review the effects and side effects of proton therapy for any indication of the eye. MATERIAL AND METHODS: : A range of databases were searched from inception to 2007. All studies that included at least ten patients and that assessed the efficacy or safety of proton therapy for any indication of the eye were included. RESULTS: : The search generated 2,385 references, of which 37 met the inclusion criteria. Five controlled trials, two comparative studies and 30 case series were found, most often reporting on uveal melanoma, choroidal melanoma and age-related macular degeneration (AMD). Methodological quality of these studies was poor. Studies were characterized by large differences in radiation techniques applied within the studies, and by variation in patient characteristics within and between studies. Results for uveal melanoma and choroidal melanoma suggest favorable survival, with, however, significant rates of side effects. Results for choroidal hemangioma and AMD did not reveal beneficial effects from proton radiation. CONCLUSION: : There is limited evidence on the effectiveness and safety of proton radiation due to the lack of well-designed and well-reported studies. There is a need to lift evidence on proton therapy to a higher level by performing dose-finding randomized controlled trials (RCTs), comparative studies of proton radiation versus standard given alternatives and prospective case studies enrolling only patients treated with up-to-date techniques, allowing extrapolation of results to similar patient groups.
Impact of an exceptionally hot dry summer on photosynthetic traits in oak (Quercus pubescens) leaves
Resumo:
BACKGROUND: The relationship between uveitis anterior in childhood and juvenile chronic arthritis (JCA, respectively JRA) has been known since 1950. In a review, the clinical picture of uveitis anterior, its prevalence, pathogenesis, prognosis and current therapy of ocular complications are presented. In addition, we will report our results of a clinical study. PATIENTS AND METHODS: In a cross-sectional study, 64 patients with juvenile chronic arthritis (JCA) had an ophthalmological screening for eye complications either from the disease itself or from the treatment. RESULTS: In 16% of the patients, an iridocyclitis was found, in one case acute, in 9 cases chronic. The cases of chronic uveitis anterior showed in 43% a combination with the classic risk factors (ANA-positive, oligoarticular, female). At the beginning of uveitis, the patients had a mean age of 81 months, at the beginning of JCA disease a mean age of 37 months. Four of 10 patients (= 40%) had eye complications from uveitis (cataract, posterior synechiae, glaucoma). Complications from therapy were found in 27%, mostly cataract as a complication of systemic and topical steroid treatment. Eighteen % had a visual acuity of 0.4 or less. CONCLUSIONS: Because of the often asymptomatic progression of chronic uveitis anterior, the risk of severe undetected eye complications is high. Therefore, an intensive interdisciplinary cooperation between rheumatologists, pediatrics and ophthalmologists is required.