1,246 research outputs found
Low myo-inositol and high glutamine levels in brain are associated with neuropsychological deterioration after induced hyperammonemia
The neuropsychological effect of hyperammonemia is variable. This study tests the hypothesis that the effect of ammonia on the neuropsychological function in patients with cirrhosis is determined by the ability of the brain to buffer ammonia-induced increase in glutamine within the astrocyte by losing osmolytes like myo-inositol (mI) and not by the magnitude of the induced hyperammonemia. Fourteen cirrhotic patients with no evidence of overt hepatic encephalopathy were given a 75-g amino acid (aa) solution mimicking the hemoglobin molecule to induce hyperammonemia. Measurement of a battery of neuropsychological function tests including immediate memory, ammonia, aa, and short-echo time proton magnetic resonance spectroscopy were performed before and 4 h after administration of the as solution. Eight patients showed deterioration in the Immediate Memory Test at 4 h. Demographic factors, severity of liver disease, change in plasma ammonia, and as profiles after the as solution were similar in those that showed a deterioration compared with those who did not. In patients who showed deterioration in the memory test, the mI-to-creatine ratio (mI/Cr) was significantly lower at baseline than those that did not deteriorate. In contrast, the glutamate/glutamine-to-Cr ratio was significantly greater in the patients that deteriorated. The observation that deterioration in the memory test scores was greater in those with lower mI/Cr supports the hypothesis that the neuropsychological effects of induced hyperammonemia is determined by the capacity of the brain to handle ammonia-induced increase in glutamine
Highly accurate calculations of the rotationally excited bound states in three-body systems
An effective optimization strategy has been developed to construct highly
accurate bound state wave functions in various three-body systems. Our
procedure appears to be very effective for computations of weakly bound states
and various excited states, including rotationally excited states, i.e. states
with . The efficiency of our procedure is illustrated by computations
of the excited states in the and muonic
molecular ions, states in the non-symmetric and
ions and and states in He atom(s)
Multifrequency Radio Observations of a SNR in the LMC. The Case of SNR J0527-6549 (DEM l204)
We present a detailed study and results of new Australia Telescope Compact
Array (ATCA) observations of supernova remnant, SNR J0527-6549. This Large
Magellanic Cloud (LMC) ob ject follows a typical supernova remnant (SNR)
horseshoe morphology with a diameter of D=(66x58)+-1 pc which is among the
largest SNRs in the LMC. Its relatively large size indicates older age while a
steeper than expected radio spectral index of aplha=-0.92+-0.11 is more typical
for younger and energetic SNRs. Also, we report detections of regions with a
high order of polarization at a peak value of ~54+-17% at 6 cm.Comment: 9 Pages, 6 figures, accepted for publication in SA
Bound state properties of four-body muonic quasi-atoms
Total energies and various bound state properties are determined for the
ground states in all six four-body muonic
quasi-atoms. These quasi-atoms contain two nuclei of the hydrogen isotopes
, one negatively charged muon and one electron
. In general, each of the four-body muonic
quasi-atoms, where , can be considered as the regular
one-electron (hydrogen) atom with the complex nucleus
which has a finite number of bound states. Furthermore, all properties of such
quasi-nuclei are determined from highly accurate
computations performed for the three-body muonic ions
with the use of pure Coulomb interaction potentials between particles. It is
shown that the bound state spectra of such quasi-atoms are similar to the
spectrum of the regular hydrogen atoms, but there are a few important
differences. Such differences can be used in future experiments to improve the
overall accuracy of current evaluations of various properties of hydrogen-like
systems, including the lowest-order relativistic and QED corrections
A Large Web-Based Observer Reliability Study of Early Ischaemic Signs on Computed Tomography. The Acute Cerebral CT Evaluation of Stroke Study (ACCESS)
BACKGROUND: Early signs of ischaemic stroke on computerised tomography (CT) scanning are subtle but CT is the most widely available diagnostic test for stroke. Scoring methods that code for the extent of brain ischaemia may improve stroke diagnosis and quantification of the impact of ischaemia. METHODOLOGY AND PRINCIPAL FINDINGS: We showed CT scans from patients with acute ischaemic stroke (n = 32, with different patient characteristics and ischaemia signs) to doctors in stroke-related specialties world-wide over the web. CT scans were shown twice, randomly and blindly. Observers entered their scan readings, including early ischaemic signs by three scoring methods, into the web database. We compared observers' scorings to a reference standard neuroradiologist using area under receiver operator characteristic curve (AUC) analysis, Cronbach's alpha and logistic regression to determine the effect of scales, patient, scan and observer variables on detection of early ischaemic changes. Amongst 258 readers representing 33 nationalities and six specialties, the AUCs comparing readers with the reference standard detection of ischaemic signs were similar for all scales and both occasions. Being a neuroradiologist, slower scan reading, more pronounced ischaemic signs and later time to CT all improved detection of early ischaemic signs and agreement on the rating scales. Scan quality, stroke severity and number of years of training did not affect agreement. CONCLUSIONS: Large-scale observer reliability studies are possible using web-based tools and inform routine practice. Slower scan reading and use of CT infarct rating scales improve detection of acute ischaemic signs and should be encouraged to improve stroke diagnosis
CRTH2 expression on T cells in asthma
Mast cell-derived prostaglandin D2 (PGD2) is the major prostanoid found within the airway of asthmatics immediately following allergen challenge. PGD2 has been shown to have chemokinetic effects on eosinophils and T helper type 2 (Th2) cells in vitro. This occurs through the interaction of PGD2 with the G-protein-coupled chemokine receptor homologous molecule expressed on Th2 lymphocytes (CRTH2). The expression of CRTH2 has been shown to be highly selective for Th2 cells. Using flow cytometry we have studied the expression of CRTH2 on T cells in blood and bronchoalveolar lavage fluid in asthmatics and normal subjects. CRTH2 expression was confined to a small percentage of blood T cells in asthmatics (1·8% ± 0·2) and normal (1·6% ± 0·2) subjects. CRTH2 was enriched significantly on interleukin (IL)-4+/IL-13+ T cells compared to interferon (IFN)-γ+ T cells (P < 0·001). There was a small population of CRTH2+ T cells in the bronchoalveolar lavage (BAL) of asthmatics (2·3% ± 0·6) and normal subjects (0·3% ± 0·1), and there was a significant difference between the two groups (P < 0·05). There were similar amounts of PGD2 in the BAL of asthma and normal subjects. Within paired blood–BAL samples from the same subject there was no increase in CRTH2+ T cells in the BAL compared to blood in asthmatics. Enrichment of CRTH2 on IL-4+ and IL-13+ T cells compared to IFN-γ+ T cells was also seen in BAL from asthmatics (P < 0·001). CRTH2 is expressed preferentially by IL-4+/IL-13+ T cells compared to IFN-γ+ T cells. However, given their small numbers they are unlikely to have a significant involvement in the pathogenesis of asthma. CRTH2 antagonism may not diminish T cell accumulation in the asthmatic lung
Cytomegalovirus infection is associated with an increase in systolic blood pressure in older individuals
Background: Cytomegalovirus (CMV) is a chronic infection that is widely distributed in the population. CMV infects a range of tissues, including endothelium, and viral replication is suppressed by the host immune system. Infection is associated with increased risk of mortality from vascular disease in older people, but the mechanisms behind this have not been determined. Aim: We investigated the association between CMV infection and cardiovascular phenotype in a cohort of healthy elderly donors. Design: CMV serostatus and cardiovascular parameters were determined in the Lothian Birth cohort, which comprises 1091 individuals aged 70 years in whom many environmental, biochemical and radiological correlates of vascular function have been determined. Methods: CMV serostatus was determined by enzyme-linked immunosorbant assay and correlated with a range of biochemical and phenotypic measures. Results: Sixty-five percent of participants were CMV seropositive, which indicates chronic infection. The mean sitting systolic blood pressure (SBP) was 149.2 mmHg in CMV seropositive individuals compared with 146.2 mmHg in CMV seronegative subjects (SD 18.7 vs. 19.7; P < 0.017). This association between CMV infection and SBP was not attenuated after adjustment for a wide range of biological and socio-economic factors. Conclusions: These data show that CMV infection is associated with an increase in SBP in individuals at age 70 years. The magnitude is comparable to environmental variables such as obesity, diabetes or high salt intake. This is the first evidence to show that a chronic infection may be an important determinant of blood pressure and could have significant implications for the future management of hypertension
Project proposal on funding for parks
This study will look at state and county level parks and see what and if there are alternative funding solutions for these parks. We will interview officials and administrators of two parks, while using surveys to gather information about visitors of the parks. The interviews that we will use for the park officials and administrators will be semi-structured. When it comes to analyzing the data we receive from the interviews, we will use three techniques: member checking, qualitative coding, and developing themes. The second method we plan on using is surveys of park visitors. We want to conduct exit surveys with visitors of two different parks, one local and one state. Approximately 200 surveys will be collected from those visiting Table Rock State Park and Nettles Park in Clemson. This will give us a good summary of what people would like and not like. From these results we would be able to make inferences about the population of park visitors, and would we be able to advise parks which funding alternatives would be successful and unsuccessful
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