1,283 research outputs found
Henri Temianka Correspondence; (feinstein)
This collection contains material pertaining to the life, career, and activities of Henri Temianka, violin virtuoso, conductor, music teacher, and author. Materials include correspondence, concert programs and flyers, music scores, photographs, and books.https://digitalcommons.chapman.edu/temianka_correspondence/3504/thumbnail.jp
Effect of anti-inflammatory agents on transforming growth factor beta over-expressing mouse brains: a model revised.
BACKGROUND: The over-expression of transforming growth factor beta-1(TGF-beta1) has been reported to cause hydrocephalus, glia activation, and vascular amyloidbeta (Abeta) deposition in mouse brains. Since these phenomena partially mimic the cerebral amyloid angiopathy (CAA) concomitant to Alzheimer's disease, the findings in TGF-beta1 over-expressing mice prompted the hypothesis that CAA could be caused or enhanced by the abnormal production of TGF-beta1. This idea was in accordance with the view that chronic inflammation contributes to Alzheimer's disease, and drew attention to the therapeutic potential of anti-inflammatory drugs for the treatment of Abeta-elicited CAA. We thus studied the effect of anti-inflammatory drug administration in TGF-beta1-induced pathology. METHODS: Two-month-old TGF-beta1 mice and littermate controls were orally administered pioglitazone, a peroxisome proliferator-activated receptor-gamma agonist, or ibuprofen, a non steroidal anti-inflammatory agent, for two months. Glia activation was assessed by immunohistochemistry and western blot analysis; Abeta precursor protein (APP) by western blot analysis; Abeta deposition by immunohistochemistry, thioflavin-S staining and ELISA; and hydrocephalus by measurements of ventricle size on autoradiographies of brain sections. Results are expressed as means +/- SD. Data comparisons were carried with the Student's T test when two groups were compared, or ANOVA analysis when more than three groups were analyzed. RESULTS: Animals displayed glia activation, hydrocephalus and a robust thioflavin-S-positive vascular deposition. Unexpectedly, these deposits contained no Abeta or serum amyloid P component, a common constituent of amyloid deposits. The thioflavin-S-positive material thus remains to be identified. Pioglitazone decreased glia activation and basal levels of Abeta42- with no change in APP contents - while it increased hydrocephalus, and had no effect on the thioflavin-S deposits. Ibuprofen mimicked the reduction of glia activation caused by pioglitazone and the lack of effect on the thioflavin-S-labeled deposits. CONCLUSIONS: i) TGF-beta1 over-expressing mice may not be an appropriate model of Abeta-elicited CAA; and ii) pioglitazone has paradoxical effects on TGF-beta1-induced pathology suggesting that anti-inflammatory therapy may reduce the damage resulting from active glia, but not from vascular alterations or hydrocephalus. Identification of the thioflavin-S-positive material will facilitate the full appraisal of the clinical implication of the effects of anti-inflammatory drugs, and provide a more thorough understanding of TGF-beta1 actions in brain
The Search for Low-mass Companions of B Stars in the Carina Nebula Cluster Trumpler 16
We have developed lists of likely B3--A0 stars (called "late B" stars) in the
young cluster Trumpler 16. The following criteria were used: location within 3'
of Eta Car, an appropriate V and B-V combination, and proper motion (where
available). Color and magnitude cuts have been made assuming an E(B-V) =0.55
mag +/- 0.1, which is a good approximation close to the center of Trumpler 16.
These lists have been cross-correlated with X-ray sources found in the Chandra
Carina Complex Project (CCCP). Previous studies have shown that only very
rarely (if at all) do late main sequence B stars produce X-rays. We present
evidence that the X-ray detected sources are binaries with low-mass companions,
since stars less massive than 1.4 Msun are strong X-ray sources at the age of
the cluster. Both the median X-ray energies and X-ray luminosities of these
sources are in good agreement with values for typical low-mass coronal X-ray
sources. We find that 39% of the late B stars based on a list with proper
motions have low-mass companions. Similarly, 32% of a sample without proper
motions have low-mass companions. We discuss the X-ray detection completeness.
These results on low-mass companions of intermediate mass stars are
complementary to spectroscopic and interferometric results, and probe new
parameter space of low mass companions at all separations. They do not support
a steeply rising distribution of mass ratios to low masses for
intermediate-mass (5 Msun) primaries, such as would be found by random pairing
from the Initial Mass Function.Comment: Accepted for the ApJS Special Issue on the Chandra Carina Complex
Project (CCCP), scheduled for publication in May 2011. All 16 CCCP Special
Issue papers are available at
http://cochise.astro.psu.edu/Carina_public/special_issue.html through 2011 at
leas
Type IIB Colliding Plane Waves
Four-dimensional colliding plane wave (CPW) solutions have played an
important role in understanding the classical non-linearities of Einstein's
equations. In this note, we investigate CPW solutions in --dimensional
Einstein gravity with a -form flux. By using an isomorphism with the
four-dimensional problem, we construct exact solutions analogous to the
Szekeres vacuum solution in four dimensions. The higher-dimensional versions of
the Khan-Penrose and Bell-Szekeres CPW solutions are studied perturbatively in
the vicinity of the light-cone. We find that under small perturbations, a
curvature singularity is generically produced, leading to both space-like and
time-like singularities. For , our results pertain to the collision of two
ten-dimensional type IIB Blau - Figueroa o'Farrill - Hull - Papadopoulos plane
waves.Comment: 20+10 pages, 2 figures, uses JHEP3.cls; v2: refs [3,10,22] corrected,
remark added below (3.9) on inexistence of conformally flat CPW in our
ansatz, final version to appear in JHE
Ischaemic strokes in patients with pulmonary arteriovenous malformations and hereditary hemorrhagic telangiectasia: associations with iron deficiency and platelets.
<div><p>Background</p><p>Pulmonary first pass filtration of particles marginally exceeding ∼7 µm (the size of a red blood cell) is used routinely in diagnostics, and allows cellular aggregates forming or entering the circulation in the preceding cardiac cycle to lodge safely in pulmonary capillaries/arterioles. Pulmonary arteriovenous malformations compromise capillary bed filtration, and are commonly associated with ischaemic stroke. Cohorts with CT-scan evident malformations associated with the highest contrast echocardiographic shunt grades are known to be at higher stroke risk. Our goal was to identify within this broad grouping, which patients were at higher risk of stroke.</p><p>Methodology</p><p>497 consecutive patients with CT-proven pulmonary arteriovenous malformations due to hereditary haemorrhagic telangiectasia were studied. Relationships with radiologically-confirmed clinical ischaemic stroke were examined using logistic regression, receiver operating characteristic analyses, and platelet studies.</p><p>Principal Findings</p><p>Sixty-one individuals (12.3%) had acute, non-iatrogenic ischaemic clinical strokes at a median age of 52 (IQR 41–63) years. In crude and age-adjusted logistic regression, stroke risk was associated not with venous thromboemboli or conventional neurovascular risk factors, but with low serum iron (adjusted odds ratio 0.96 [95% confidence intervals 0.92, 1.00]), and more weakly with low oxygen saturations reflecting a larger right-to-left shunt (adjusted OR 0.96 [0.92, 1.01]). For the same pulmonary arteriovenous malformations, the stroke risk would approximately double with serum iron 6 µmol/L compared to mid-normal range (7–27 µmol/L). Platelet studies confirmed overlooked data that iron deficiency is associated with exuberant platelet aggregation to serotonin (5HT), correcting following iron treatment. By MANOVA, adjusting for participant and 5HT, iron or ferritin explained 14% of the variance in log-transformed aggregation-rate (p = 0.039/p = 0.021).</p><p>Significance</p><p>These data suggest that patients with compromised pulmonary capillary filtration due to pulmonary arteriovenous malformations are at increased risk of ischaemic stroke if they are iron deficient, and that mechanisms are likely to include enhanced aggregation of circulating platelets.</p></div
Nutrition Support in Acute Kidney Injury
Acute kidney injury is a frequent complication affecting many hospitalized patients and is associated with increased morbidity and mortality. Acute kidney injury often occurs in conjunction with critical illness, which is a hypermetabolic state presenting with hyperglycemia, insulin resistance, hypertriglyceridemia, and increased protein catabolism. In addition to addressing these changes, the clinician should evaluate the important nutrition implications of decreased kidney function. These include vitamins, electrolytes, minerals, trace elements, and the presence and type of renal replacement therapy. Optimal nutrition management in acute kidney injury includes providing adequate macronutrient support to correct underlying conditions and prevent ongoing loss, supplementing micronutrients and vitamins during renal replacement therapy, and adjusting electrolyte replacement based on the degree and extent of renal dysfunction
FUSE Measurements of Far Ultraviolet Extinction. I. Galactic Sight Lines
We present extinction curves that include data down to far ultraviolet
wavelengths (FUV; 1050 - 1200 A) for nine Galactic sight lines. The FUV
extinction was measured using data from the Far Ultraviolet Spectroscopic
Explorer. The sight lines were chosen for their unusual extinction properties
in the infrared through the ultraviolet; that they probe a wide range of dust
environments is evidenced by the large spread in their measured ratios of
total-to-selective extinction, R_V = 2.43 - 3.81. We find that extrapolation of
the Fitzpatrick & Massa relationship from the ultraviolet appears to be a good
predictor of the FUV extinction behavior. We find that predictions of the FUV
extinction based upon the Cardelli, Clayton & Mathis (CCM) dependence on R_V
give mixed results. For the seven extinction curves well represented by CCM in
the infrared through ultraviolet, the FUV extinction is well predicted in three
sight lines, over-predicted in two sight lines, and under-predicted in 2 sight
lines. A Maximum Entropy Method analysis using a simple three component grain
model shows that seven of the nine sight lines in the study require a larger
fraction of grain materials to be in dust when FUV extinction is included in
the models. Most of the added grain material is in the form of small (radii <
200 A) grains.Comment: Accepted for publication in the Astrophysical Journal. 31 pages with
7 figure
A survey of statistics in three UK general practice journal
Background
Many medical specialities have reviewed the statistical content of their journals. To our knowledge this has not been done in general practice. Given the main role of a general practitioner as a diagnostician we thought it would be of interest to see whether the statistical methods reported reflect the diagnostic process.
Methods
Hand search of three UK journals of general practice namely the British Medical Journal (general practice section), British Journal of General Practice and Family Practice over a one-year period (1 January to 31 December 2000).
Results
A wide variety of statistical techniques were used. The most common methods included t-tests and Chi-squared tests. There were few articles reporting likelihood ratios and other useful diagnostic methods. There was evidence that the journals with the more thorough statistical review process reported a more complex and wider variety of statistical techniques.
Conclusions
The BMJ had a wider range and greater diversity of statistical methods than the other two journals. However, in all three journals there was a dearth of papers reflecting the diagnostic process. Across all three journals there were relatively few papers describing randomised controlled trials thus recognising the difficulty of implementing this design in general practice
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