357 research outputs found
A double-label study of efferent projections from the Edinger-Westphal nucleus in goldfish and kelp bass
The Edinger-Westphal nucleus in goldfish was identified by retrograde labeling from the ciliary ganglion. In the same animals a few neurons near this nucleus (perinuclear Edinger-Westphal neurons) were labeled by a different retrograde tracer injected into the cerebellum. No double-labeled cells were found. Similar results were obtained in kelp bass, except that in this species no cerebellar-projecting perinuclear neurons were observed. Cerebellar-projecting Edinger-Westphal neurons have previously been described in some mammals, but not in other vertebrates. Therefore the homology of cerebellar-projecting cells of the Edinger-Westphal region in mammals and teleost fishes is doubtful
Endoscopic ultrasound—guided fine needle aspiration in the diagnosis of mediastinal masses of unknown origin
The ability of endosonography to diagnose a variety of gastrointestinal pathology has been significantly advanced with the introduction of endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) biopsy. EUS-FNA technology can also be applied to the evaluation of non-GI disorders. The role of EUS-FNA to establish the diagnosis of unexplained mediastinal masses has not been previously described. The aim of this study was to determine the diagnostic accuracy, impact on subsequent workup, and role of EUS-FNA in treating mediastinal masses of unknown cause. METHODS : A total of 26 patients (15 men and 11 women, mean age 61 yr, range 39–77 yr) underwent EUS-FNA in patients presenting with unexplained mediastinal masses at four tertiary referral centers. Presenting symptoms included: chest pain (10 patients), dysphagia (eight), cough (seven), fever (six), night sweats (three), and no symptoms/abnormal x-ray (five patients). Five of 26 patients had prior history of cancer (three lung, one tracheal, and one esophageal). RESULTS : Final diagnosis using EUS-FNA, surgery, autopsy, other diagnostic study, or long-term follow-up was available in all patients. EUS-FNA results were classified under three disease categories: 1) infectious, 2) benign/inflammatory, and 3) malignant. Final diagnosis included infectious in five patents, benign/inflammatory in nine, and malignant in 12. EUS-FNA was successful in 21 of 26 patients (81%) for all disease categories (infectious 60%, benign/inflammatory 78%, and malignant 92%). EUS-FNA was successful in directing subsequent workup in 77% (20 of 26) and therapy in 73% (19 of 26). Mean EUS-FNA passes for adequate tissue sampling was lower of nonmalignant disease categories (3.0 and 3.4) versus malignant disease (4.4). No complications were seen during the course of this study. CONCLUSIONS : EUS-FNA in patients presenting with idiopathic mediastinal masses establishes the diagnosis in the vast majority of cases, particularly for those with malignant disease. The emergence of transesophageal EUS-FNA of the mediastinum provides the ability to alter subsequent workup and therapy, obviating the need for more invasive diagnostic studies such as thoracotomy.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72588/1/j.1572-0241.2002.06023.x.pd
The myopic eye of the black moor goldfish
Optical and anatomical methods were used to establish the refractive state of the eye of the Black Moor variety of goldfish. The eye is strongly myopic. The refractive error in 12 eyes from 6 fish ranged from 89 to 268 D.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/26461/1/0000549.pd
Engineered swift equilibration of a Brownian particle
A fundamental and intrinsic property of any device or natural system is its
relaxation time relax, which is the time it takes to return to equilibrium
after the sudden change of a control parameter [1]. Reducing relax , is
frequently necessary, and is often obtained by a complex feedback process. To
overcome the limitations of such an approach, alternative methods based on
driving have been recently demonstrated [2, 3], for isolated quantum and
classical systems [4--9]. Their extension to open systems in contact with a
thermostat is a stumbling block for applications. Here, we design a
protocol,named Engineered Swift Equilibration (ESE), that shortcuts
time-consuming relaxations, and we apply it to a Brownian particle trapped in
an optical potential whose properties can be controlled in time. We implement
the process experimentally, showing that it allows the system to reach
equilibrium times faster than the natural equilibration rate. We also estimate
the increase of the dissipated energy needed to get such a time reduction. The
method paves the way for applications in micro and nano devices, where the
reduction of operation time represents as substantial a challenge as
miniaturization [10]. The concepts of equilibrium and of transformations from
an equilibrium state to another, are cornerstones of thermodynamics. A textbook
illustration is provided by the expansion of a gas, starting at equilibrium and
expanding to reach a new equilibrium in a larger vessel. This operation can be
performed either very slowly by a piston, without dissipating energy into the
environment, or alternatively quickly, letting the piston freely move to reach
the new volume
Phenotypic and molecular assessment of seven patients with 6p25 deletion syndrome: Relevance to ocular dysgenesis and hearing impairment
BACKGROUND: Thirty-nine patients have been described with deletions involving chromosome 6p25. However, relatively few of these deletions have had molecular characterization. Common phenotypes of 6p25 deletion syndrome patients include hydrocephalus, hearing loss, and ocular, craniofacial, skeletal, cardiac, and renal malformations. Molecular characterization of deletions can identify genes that are responsible for these phenotypes. METHODS: We report the clinical phenotype of seven patients with terminal deletions of chromosome 6p25 and compare them to previously reported patients. Molecular characterization of the deletions was performed using polymorphic marker analysis to determine the extents of the deletions in these seven 6p25 deletion syndrome patients. RESULTS: Our results, and previous data, show that ocular dysgenesis and hearing impairment are the two most highly penetrant phenotypes of the 6p25 deletion syndrome. While deletion of the forkhead box C1 gene (FOXC1) probably underlies the ocular dysgenesis, no gene in this region is known to be involved in hearing impairment. CONCLUSIONS: Ocular dysgenesis and hearing impairment are the two most common phenotypes of 6p25 deletion syndrome. We conclude that a locus for dominant hearing loss is present at 6p25 and that this locus is restricted to a region distal to D6S1617. Molecular characterization of more 6p25 deletion patients will aid in refinement of this locus and the identification of a gene involved in dominant hearing loss
Quark Potential in a Quark-Meson Plasma
We investigate quark potential by considering meson exchanges in the two
flavor Nambu--Jona-Lasinio model at finite temperature and density. There are
two kinds of oscillations in the chiral restoration phase, one is the Friedel
oscillation due to the sharp quark Fermi surface at high density, and the other
is the Yukawa oscillation driven by the complex meson poles at high
temperature. The quark-meson plasma is strongly coupled in the temperature
region with being the critical temperature of
chiral phase transition. The maximum coupling in this region is located at the
critical point.Comment: 8 pages and 8 figure
Measuring discomfort from glare: recommendations for good practice
This article presents a review of the methods used for subjective evaluation of discomfort from glare, focusing on the two procedures most frequently used in past research – adjustment and category rating. Evidence is presented to demonstrate that some aspects of these procedures influence the evaluation, such as the range of glare source luminances available in an adjustment procedure, leading to biased evaluations and which hence reduce the reliability and validity of the data. The article offers recommendations for good practice when using these procedures and also suggests alternative methods that might be explored in further work
Developing a Wellbeing Framework for Aboriginal and Torres Strait Islander Peoples Living with Chronic Disease (Wellbeing Study)
Addressing a need identified by Aboriginal and Torres Strait Islander peoples and their primary
healthcare providers, this study developed a Wellbeing Framework for managing chronic disease in
a manner that also supports wellbeing.
Chronic care models that are currently in use usually focus upon the systems, resources and
policies that are required to deliver care. The important roles of culture, spirituality, Country and
family in maintaining health and wellbeing are notably absent from such models.
Re-defining the way in which care is delivered to reflect Aboriginal and Torres Strait Islander
peoples’ needs and values is essential for improving the accessibility and acceptability of primary
healthcare services.The research reported in this paper is a project of the Australian Primary Health Care Research Institute which is supported by a grant from the Australian Government Department of Health and Ageing under the Primary Health Care Research Evaluation and Development Strategy
Mathematical model of a telomerase transcriptional regulatory network developed by cell-based screening: analysis of inhibitor effects and telomerase expression mechanisms
Cancer cells depend on transcription of telomerase reverse transcriptase (TERT). Many transcription factors affect TERT, though regulation occurs in context of a broader network. Network effects on telomerase regulation have not been investigated, though deeper understanding of TERT transcription requires a systems view. However, control over individual interactions in complex networks is not easily achievable. Mathematical modelling provides an attractive approach for analysis of complex systems and some models may prove useful in systems pharmacology approaches to drug discovery. In this report, we used transfection screening to test interactions among 14 TERT regulatory transcription factors and their respective promoters in ovarian cancer cells. The results were used to generate a network model of TERT transcription and to implement a dynamic Boolean model whose steady states were analysed. Modelled effects of signal transduction inhibitors successfully predicted TERT repression by Src-family inhibitor SU6656 and lack of repression by ERK inhibitor FR180204, results confirmed by RT-QPCR analysis of endogenous TERT expression in treated cells. Modelled effects of GSK3 inhibitor 6-bromoindirubin-3′-oxime (BIO) predicted unstable TERT repression dependent on noise and expression of JUN, corresponding with observations from a previous study. MYC expression is critical in TERT activation in the model, consistent with its well known function in endogenous TERT regulation. Loss of MYC caused complete TERT suppression in our model, substantially rescued only by co-suppression of AR. Interestingly expression was easily rescued under modelled Ets-factor gain of function, as occurs in TERT promoter mutation. RNAi targeting AR, JUN, MXD1, SP3, or TP53, showed that AR suppression does rescue endogenous TERT expression following MYC knockdown in these cells and SP3 or TP53 siRNA also cause partial recovery. The model therefore successfully predicted several aspects of TERT regulation including previously unknown mechanisms. An extrapolation suggests that a dominant stimulatory system may programme TERT for transcriptional stability
Dynamic light scattering study on phase separation of a protein-water mixture: Application on cold cataract development in the ocular lens
We present a detailed dynamic light scattering study on the phase separation
in the ocular lens emerging during cold cataract development. Cold cataract is
a phase separation effect that proceeds via spinodal decomposition of the lens
cytoplasm with cooling. Intensity auto-correlation functions of the lens
protein content are analyzed with the aid of two methods providing information
on the populations and dynamics of the scattering elements associated with cold
cataract. It is found that the temperature dependence of many measurable
parameters changes appreciably at the characteristic temperature ~16+1 oC which
is associated with the onset of cold cataract. Extending the temperature range
of this work to previously inaccessible regimes, i.e. well below the phase
separation or coexistence curve at Tcc, we have been able to accurately
determine the temperature dependence of the collective and self-diffusion
coefficient of proteins near the spinodal. The analysis showed that the
dynamics of proteins bears some resemblance to the dynamics of structural
glasses where the apparent activation energy for particle diffusion increases
below Tcc indicating a highly cooperative motion. Application of ideas
developed for studying the critical dynamics of binary protein/solvent
mixtures, as well as the use of a modified Arrhenius equation, enabled us to
estimate the spinodal temperature Tsp of the lens nucleus. The applicability of
dynamic light scattering as a non-invasive, early-diagnostic tool for ocular
diseases is also demonstrated in the light of the findings of the present
paper
- …