443 research outputs found
Comment on: "Diagnosis of Periprosthetic Joint Infection: The Role of Nuclear Medicine May Be Overestimated" by Claudio Diaz-Ledezma, Courtney Lamberton, Paul Lichtstein and Javad Parvizi
We read with interest the article by Diaz-Ledezma et al entitled“Diagnosis of Periprosthetic Joint Infection: The Role of NuclearMedicine May Be Overestimated”recently published in The Journal ofArthroplast
Detection of osteomyelitis in the diabetic foot by imaging techniques. A systematic review and meta-analysis comparing mri, white blood cell scintigraphy, and FDG-PET
OBJECTIVE Diagnosing bone infection in the diabetic foot is challenging and often requires several diagnostic procedures, including advanced imaging. We compared the diagnostic performances of MRI, radiolabeled white blood cell (WBC) scintigraphy (either with 99mTc-hexamethylpropyleneamineoxime [HMPAO] or 111In-oxine), and [18F]fluorodeoxyglucose positron emission tomography (18F-FDG-PET)/ computed tomography. RESEARCH DESIGN AND METHODS We searchedMedline andEmbase as of August 2016 for studies of diagnostic tests on patients known or suspected to have diabetes and a foot infection. We performed a systematic review using criteria recommended by the Cochrane Review of a database that included prospective and retrospective diagnostic studies performed on patients with diabetes in whom there was a clinical suspicion of osteomyelitis of the foot. The preferred reference standard was bone biopsy and subsequent pathological (or microbiological) examination. RESULTS Our review found 6,649 articles; 3,894 in Medline and 2,755 in Embase. A total of 27 full articles and 2 posters was selected for inclusion in the analysis. The performance characteristics for the 18F-FDG-PET were: sensitivity, 89%; specificity, 92%; diagnostic odds ratio (DOR), 95; positive likelihood ratio (LR), 11; and negative LR, 0.11. For WBC scan with 111In-oxine, the values were: sensitivity, 92%; specificity, 75%; DOR, 34; positive LR, 3.6; and negative LR, 0.1. For WBC scan with 99mTc-HMPAO, the values were: sensitivity, 91%; specificity, 92%; DOR, 118; positive LR, 12; and negative LR, 0.1. Finally, forMRI, the valueswere: sensitivity, 93%; specificity, 75%; DOR, 37; positive LR, 3.66, and negative LR, 0.10. CONCLUSIONS The various modalities have similar sensitivity, but 18F-FDG-PET and 99mTc-HMPAO-labeled WBC scintigraphy offer the highest specificity. Larger prospective studies with a direct comparison among the different imaging techniques are required
Guidelines for the labelling of leucocytes with 111In-oxine
We describe here a protocol for labelling autologous white blood cells with 111In-oxine based on previously published consensus papers and guidelines. This protocol includes quality control and safety procedures and is in accordance with current European Union regulations and International Atomic Energy Agency recommendations
Consensus document for the diagnosis of prosthetic joint infections. a joint paper by the EANM, EBJIS, and ESR (with ESCMID endorsement)
Background: For the diagnosis of prosthetic joint infection, real evidence-based guidelines to aid clinicians in choosing the most accurate diagnostic strategy are lacking. Aim and Methods: To address this need, we performed a multidisciplinary systematic review of relevant nuclear medicine, radiological, orthopaedic, infectious, and microbiological literature to define the diagnostic accuracy of each diagnostic technique and to address and provide evidence-based answers on uniform statements for each topic that was found to be important to develop a commonly agreed upon diagnostic flowchart. Results and Conclusion: The approach used to prepare this set of multidisciplinary guidelines was to define statements of interest and follow the procedure indicated by the Oxford Centre for Evidence-based Medicine (OCEBM)
The first spectral line surveys searching for signals from the Dark Ages
Our aim is to observationally investigate the cosmic Dark Ages in order to
constrain star and structure formation models, as well as the chemical
evolution in the early Universe. Spectral lines from atoms and molecules in
primordial perturbations at high redshifts can give information about the
conditions in the early universe before and during the formation of the first
stars in addition to the epoch of reionisation. The lines may arise from moving
primordial perturbations before the formation of the first stars (resonant
scattering lines), or could be thermal absorption or emission lines at lower
redshifts. The difficulties in these searches are that the source redshift and
evolutionary state, as well as molecular species and transition are unknown,
which implies that an observed line can fall within a wide range of
frequencies. The lines are also expected to be very weak. Observations from
space have the advantages of stability and the lack of atmospheric features
which is important in such observations. We have therefore, as a first step in
our searches, used the Odin satellite to perform two sets of spectral line
surveys towards several positions. The first survey covered the band 547-578
GHz towards two positions, and the second one covered the bands 542.0-547.5 GHz
and 486.5-492.0 GHz towards six positions selected to test different sizes of
the primordial clouds. Two deep searches centred at 543.250 and 543.100 GHz
with 1 GHz bandwidth were also performed towards one position. The two lowest
rotational transitions of H2 will be redshifted to these frequencies from
z~20-30, which is the predicted epoch of the first star formation. No lines are
detected at an rms level of 14-90 and 5-35 mK for the two surveys,
respectively, and 2-7 mK in the deep searches with a channel spacing of 1-16
MHz. The broad bandwidth covered allows a wide range of redshifts to be
explored for a number of atomic and molecular species and transitions. From the
theoretical side, our sensitivity analysis show that the largest possible
amplitudes of the resonant lines are about 1 mK at frequencies <200 GHz, and a
few micro K around 500-600 GHz, assuming optically thick lines and no
beam-dilution. However, if existing, thermal absorption lines have the
potential to be orders of magnitude stronger than the resonant lines. We make a
simple estimation of the sizes and masses of the primordial perturbations at
their turn-around epochs, which previously has been identified as the most
favourable epoch for a detection. This work may be considered as an important
pilot study for our forthcoming observations with the Herschel Space
Observatory.Comment: 15 pages, 9 figures, 3 on-line pages. Accepted for publication in
Astronomy & Astrophysics 8 March 2010
Maki Parameter and Upper critical Field of the Heavy-Fermion Superconductor UBe13
We have performed low-temperature specific-heat measurements in magnetic
fields for a single crystal UBe13. It has been observed that our sample
exhibits a superconducting transition at an intermediate temperature between
previously reported values for two variant samples called H type and L type.
The specific heat C(T) of our sample shows a T^3 behavior in the temperature
range below 0.7 Tc, which is similar to the behavior of the H-type sample,
suggesting the existence of point nodes in the superconducting gap function. We
have obtained the upper-critical-field curves Hc2 for the [001], [110], and
[111] crystal axes, which show no anisotropy at least down to the lowest
measured temperature of 0.5 K. We have also derived the Maki parameter kappa2,
and it has been revealed that the kappa2 steeply decreases isotropically upon
cooling just below Tc. Paramagnetic effects and the symmetry of Cooper pairing
of UBe13 are discussed.Comment: 4 pages, 5 figure
Differential Production Cross Section of Z Bosons as a Function of Transverse Momentum at sqrt{s}=1.8 TeV
We present a measurement of the transverse momentum distribution of Z bosons
produced in ppbar collisions at sqrt{s}=1.8 TeV using data collected by the D0
experiment at the Fermilab Tevatron Collider during 1994--1996. We find good
agreement between our data and a current resummation calculation. We also use
our data to extract values of the non-perturbative parameters for a particular
version of the resummation formalism, obtaining significantly more precise
values than previous determinations.Comment: 10 pages, 2 figures, submitted to Phys. Rev. Letters v2 has margin
error correcte
Search for Top Squark Pair Production in the Dielectron Channel
This report describes the first search for top squark pair production in the
channel stop_1 stopbar_1 -> b bbar chargino_1 chargino_1 -> ee+jets+MEt using
74.9 +- 8.9 pb^-1 of data collected using the D0 detector. A 95% confidence
level upper limit on sigma*B is presented. The limit is above the theoretical
expectation for sigma*B for this process, but does show the sensitivity of the
current D0 data set to a particular topology for new physics.Comment: Five pages, including three figures, submitted to PRD Brief Report
Search for First Generation Scalar Leptoquark Pairs in ppbar Collisions at sqrt(s)=1.8 TeV
We have searched for first generation scalar leptoquark (LQ) pairs in the
enu+jets channel using ppbar collider data (integrated luminosity= 115 pb^-1)
collected by the DZero experiment at the Fermilab Tevatron during 1992-96. The
analysis yields no candidate events. We combine the results with those from the
ee+jets and nunu+jets channels to obtain 95% confidence level (CL) upper limits
on the LQ pair production cross section as a function of mass and of beta, the
branching fraction to a charged lepton. Comparing with the next-to-leading
order theory, we set 95% CL lower limits on the LQ mass of 225, 204, and 79
GeV/c^2 for beta=1, 1/2, and 0, respectively.Comment: 14 pages, 4 figures, submitted to Physical Review Letters Replaced to
correct visitor addresse
Direct Measurement of the Top Quark Mass at D0
We determine the top quark mass m_t using t-tbar pairs produced in the D0
detector by \sqrt{s} = 1.8 TeV p-pbar collisions in a 125 pb^-1 exposure at the
Fermilab Tevatron. We make a two constraint fit to m_t in t-tbar -> b W^+bbar
W^- final states with one W boson decaying to q-qbar and the other to e-nu or
mu-nu. Likelihood fits to the data yield m_t(l+jets) = 173.3 +- 5.6 (stat) +-
5.5 (syst) GeV/c^2. When this result is combined with an analysis of events in
which both W bosons decay into leptons, we obtain m_t = 172.1 +- 5.2 (stat) +-
4.9 (syst) GeV/c^2. An alternate analysis, using three constraint fits to fixed
top quark masses, gives m_t(l+jets) = 176.0 +- 7.9 (stat) +- 4.8 (syst)
GeV/C^2, consistent with the above result. Studies of kinematic distributions
of the top quark candidates are also presented.Comment: 43 pages, 53 figures, 33 tables. RevTeX. Submitted to Phys. Rev.
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