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111.
Bronstein JM Ounpraseuth S Jonkman J Lowery CL Fletcher D Nugent RR Hall RW 《Health services research》2011,46(4):1082-1103
Objective. To examine the factors associated with delivery of preterm infants at neonatal intensive care unit (NICU) hospitals in Arkansas during the period 2001–2006, with a focus on the impact of a Medicaid supported intervention, Antenatal and Neonatal Guidelines, Education, and Learning System (ANGELS), that expanded the consulting capacity of the academic medical center's maternal fetal medicine practice. Data Sources. A dataset of linked Medicaid claims and birth certificates for the time period by clustering Medicaid claims by pregnancy episode. Pregnancy episodes were linked to residential county‐level demographic and medical resource characteristics. Deliveries occurring before 35 weeks gestation (n=5,150) were used for analysis. Study Design. Logistic regression analysis was used to examine time trends and individual, county, and intervention characteristics associated with delivery at hospitals with NICU, and delivery at the academic medical center. Principal Findings. Perceived risk, age, education, and prenatal care characteristics of women affected the likelihood of use of the NICU. The perceived availability of local expertise was associated with a lower likelihood that preterm infants would deliver at the NICU. ANGELS did not increase the overall use of NICU, but it did shift some deliveries to the academic setting. Conclusion. Perinatal regionalization is the consequence of a complex set of provider and patient decisions, and it is difficult to alter with a voluntary program. 相似文献
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The Tullio phenomenon refers to sound-induced disequilibrium or oscillopsia. Patients with this condition frequently present
to neurologists, many of whom are unfamiliar with the condition and its diagnostic criteria. Indeed, due to the unusual nature
of the symptoms patients are often misdiagnosed as having psychiatric disturbances. Tullio patients describe disequilibrium,
auditory and visual symptoms, which are recurrent, brief, and often triggered by loud noises or middle ear pressure changes,
e.g. the Valsalva manoeuvre. Many cases are associated with superior semicircular canal dehiscence (SCCD). Early work suggested
that the presence of sound-induced torsional eye movements and visual field tilts were consequent upon a utricular-mediated
ocular tilt reaction. However, more recent evidence from imaging and oculographic research, as well as data from our patient
series indicates that these ocular abnormalities are usually the result of superior semicircular canal stimulation. The clinical
history and a focussed examination are often sufficient to make the diagnosis, which can be confirmed with high resolution
CT imaging of the temporal bones. In some patients, surgical occlusion or resurfacing of the affected canal can ameliorate
symptoms and signs. The aim of this paper is two-fold: Firstly, to review the clinical features of the Tullio phenomenon,
and secondly, to highlight our own observations in three cases with a new clinical syndrome consisting of Tullio’s phenomenon
with bilateral vestibular failure, a pure horizontal nystagmus in response to sound, and no evidence of canal dehiscence. 相似文献
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Renal cell carcinoma is an inherently chemotherapeutically resistant neoplasm. Because of this, new drugs targeting this tumor are needed. One class of new anticancer drug targets the enzyme DNA topoisomerase I. Laboratory data indicate that cells sensitive to topo I targeting drugs contain high topo I levels. To determine whether some renal cell carcinomas contain elevated topo I and might therefore be targets of topo I active antitumor agents, we used a new immunohistochemical stain for topo I to determine the expression of the enzyme in 51 tumors of the kidney. Increased topo I expression was found in 4 of 11 (36%) grade 3 renal cell carcinomas and in 8 of 8 (100%) grade 4 renal cell carcinomas. Normal topo I expression was observed in all adenomas, oncocytomas, and grade 1 and grade 2 renal cell carcinomas. Because topo I targeted anticancer drugs are S-phase specific, topo II-alpha and MIB-1 proliferation indices also were performed. Topo II-alpha correlates well with MIB-1 (correlation coefficient = 0.96). Of the 12 tumors with elevated topo I, only 3 had topo II-alpha proliferation indices greater than 40, indicating a tumor with elevated topo I expression and a large growth fraction. We hypothesize that these tumors might be susceptible to topo I anticancer drug therapy. In addition, we found that the average topo II-alpha proliferation index of tumors from patients who died of disease was 27.4 +/- 19.8, which was statistically different from the average topo II-alpha index of 5.8 +/- 6.5 observed in tumors from patients who remained alive during our follow-up. 相似文献
116.
Behavioral consequences of innate preferences and olfactory learning in hawkmoth-flower interactions
Riffell JA Alarcón R Abrell L Davidowitz G Bronstein JL Hildebrand JG 《Proceedings of the National Academy of Sciences of the United States of America》2008,105(9):3404-3409
Spatiotemporal variability in floral resources can have ecological and evolutionary consequences for both plants and the pollinators on which they depend. Seldom, however, can patterns of flower abundance and visitation in the field be linked with the behavioral mechanisms that allow floral visitors to persist when a preferred resource is scarce. To explore these mechanisms better, we examined factors controlling floral preference in the hawkmoth Manduca sexta in the semiarid grassland of Arizona. Here, hawkmoths forage primarily on flowers of the bat-adapted agave, Agave palmeri, but shift to the moth-adapted flowers of their larval host plant, Datura wrightii, when these become abundant. Both plants emit similar concentrations of floral odor, but scent composition, nectar, and flower reflectance are distinct between the two species, and A. palmeri flowers provide six times as much chemical energy as flowers of D. wrightii. Behavioral experiments with both naïve and experienced moths revealed that hawkmoths learn to feed from agave flowers through olfactory conditioning but readily switch to D. wrightii flowers, for which they are the primary pollinator, based on an innate odor preference. Behavioral flexibility and the olfactory contrast between flowers permit the hawkmoths to persist within a dynamic environment, while at the same time to function as the major pollinator of one plant species. 相似文献
117.
Adult growth hormone deficiency (AGHD) is a well-established clinical entity with heterogeneous characteristics, in which the main causes are hypothalamus-pituitary tumors and/or their treatment. The diagnosis of ADGH should be considered in patients with a prior history of childhood-onset GH deficiency or a history of organic hypothalamus-pituitary disease. In these patients diagnosis is performed biochemically by provocative tests of GH secretion, once the measurement of the biological markers for GH action:IGF-l and IGFBP-3 levels, can be in the normal range in an important percentage of AGHD patients. The current treatment using an initial low dose of hrGH followed by individualised dose titration adjusted according to serum IGF-1 levels, leads to similar beneficial effects with less incidence of side effects, improved tolerance to treatment and a lower stable GH dose as compared to hrGH replacement therapy based on body weight or body surface area. As some patients might not profit from hrGH therapy, the potential beneficial effects of hrGH replacement therapy should be analyzed on individualized basis. Alternative available therapies with similar efficacy should be taken into consideration. Physical activity may improve body compostion, cardiovascular perfomance and well being in ADGH subjects not submitted to hrGH treatment. An important target of hrGH replacement therapy is its impact on quality of life, leading to social and professional improvement. Epidemiological evidence points to a decreasing life expectancy in ADGH patients but data regarding the impact of hrGH replacement on life expectancy are still lacking. 相似文献
118.
Induced Microphase Separation in Hybrid Composite Polymer Electrolytes Based on Poly(acrylonitrile‐r‐butadienes) and Ionic Liquids 下载免费PDF全文
Michael Wirey Marcus Hunt Tyler Blensdorf Barry D. Stein Ulrike Werner‐Zwanziger Margaret A. Hanson Waleed E. Mahmoud Ahmed A. Al‐Ghamdi John Carini Lyudmila M. Bronstein 《Macromolecular chemistry and physics.》2016,217(6):794-803
Novel hybrid, composite polymer electrolytes (HCPEs) based on poly(acrylonitrile‐r‐butadiene) (PAN‐r‐PB), CN‐modified silica nanoparticles (CN‐MSNs), Li triflate, and ionic liquids (ILs) are synthesized. Using a combination of methods, it is demonstrated that these materials segregate into PAN‐rich and PB‐rich phases, the behavior of which changes depending on the IL type. The incorporation of ILs containing hexyl and octyl substituents at the imidazolium rings leads to a higher mobility of the PB‐rich phase and a decrease of the density of the neighboring PAN‐rich phase, allowing an improvement of the Li ion conductivity. However, with an increase of the substituent length from decyl to dodecyl, ordering of the hydrophobic tails in the PB‐rich phase leads to both stiffening of the latter and corresponding ordering of the ionic pairs of ILs, resulting in a decreased conductivity. The results of this work are broadly applicable for controlling the structure and properties of polymeric materials exhibiting microphase segregation.
119.
120.
The ability to set a straight line to the perceived gravitational vertical (subjective visual vertical, SVV) was investigated in a 21 year old woman with long standing left hemihypaesthesia due to a posterior thalamic infarct. The putative structures involved were the somatosensory and vestibular thalamus (VPL, VPM) and associative (pulvinar) thalamus. The SVV was normal when seated upright. When lying on her right side, line settings deviated about 17 degrees to the right, which is the normal A-effect. When lying on the hypaesthetic side the mean SVV remained close to true vertical-that is, the A-effect was absent, and there was a large increase in variability of the SVV settings. The findings support the view that the body tilt-induced bias of the SVV (A-effect) is largely mediated by somatosensory afferents. The finding that the A-effect was absent only when lying on the hypaesthetic side suggests that, during body tilt, the somatosensory system participates in visuogravitational orientation. 相似文献