301 research outputs found

    Pattern of lateral neck metastases in N0 papillary thyroid carcinoma

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    <p>Abstract</p> <p>Background</p> <p>Indication and extent of lateral prophylactic neck dissection (PLND) in papillary thyroid carcinoma (PTC) is very controversial.</p> <p>Methods</p> <p>We retrospectively analysed 131 patients who underwent thyroidectomy and prophylactic lateral neck dissection from level II to V for PTC.</p> <p>Results</p> <p>140 PLND were performed. The occult lymph node metastases (OLNM) overall rate was 18.6%. The incidence of node involvement was 10% at level III and 6.4% at level IIa. Level IV and level Vb were both concerned by 5.7% OLNM. Only 2.9% of level IIb contained OLNM. None of the level Va ND revealed OLNM.</p> <p>Conclusions</p> <p>OLNM from PTC occurs commonly in level IIa, III, IV and Vb. Incidence in other levels is low. For surgeons that usually perform PLND, we believe that a selective neck dissection of levels IIa, III, IV and Vb in N0 neck PTC is sufficient for the clearance of occult metastases.</p

    Migraine headaches in Chronic Fatigue Syndrome (CFS): Comparison of two prospective cross-sectional studies

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    <p>Abstract</p> <p>Background</p> <p>Headaches are more frequent in Chronic Fatigue Syndrome (CFS) than healthy control (HC) subjects. The 2004 International Headache Society (IHS) criteria were used to define CFS headache phenotypes.</p> <p>Methods</p> <p>Subjects in Cohort 1 (HC = 368; CFS = 203) completed questionnaires about many diverse symptoms by giving nominal (yes/no) answers. Cohort 2 (HC = 21; CFS = 67) had more focused evaluations. They scored symptom severities on 0 to 4 anchored ordinal scales, and had structured headache evaluations. All subjects had history and physical examinations; assessments for exclusion criteria; questionnaires about CFS related symptoms (0 to 4 scale), Multidimensional Fatigue Inventory (MFI) and Medical Outcome Survey Short Form 36 (MOS SF-36).</p> <p>Results</p> <p>Demographics, trends for the number of diffuse "functional" symptoms present, and severity of CFS case designation criteria symptoms were equivalent between CFS subjects in Cohorts 1 and 2. HC had significantly fewer symptoms, lower MFI and higher SF-36 domain scores than CFS in both cohorts. Migraine headaches were found in 84%, and tension-type headaches in 81% of Cohort 2 CFS. This compared to 5% and 45%, respectively, in HC. The CFS group had migraine without aura (60%; MO; CFS+MO), with aura (24%; CFS+MA), tension headaches only (12%), or no headaches (4%). Co-morbid tension and migraine headaches were found in 67% of CFS. CFS+MA had higher severity scores than CFS+MO for the sum of scores for poor memory, dizziness, balance, and numbness ("Neuro-construct", p = 0.002) and perceived heart rhythm disturbances, palpitations and noncardiac chest pain ("Cardio-construct"; p = 0.045, t-tests after Bonferroni corrections). CFS+MO subjects had lower pressure-induced pain thresholds (2.36 kg [1.95-2.78; 95% C.I.] n = 40) and a higher prevalence of fibromyalgia (47%; 1990 criteria) compared to HC (5.23 kg [3.95-6.52] n = 20; and 0%, respectively). Sumatriptan was beneficial for 13 out of 14 newly diagnosed CFS migraine subjects.</p> <p>Conclusions</p> <p>CFS subjects had higher prevalences of MO and MA than HC, suggesting that mechanisms of migraine pathogenesis such as central sensitization may contribute to CFS pathophysiology.</p> <p>Clinical Trial Registration</p> <p>Georgetown University IRB # 2006-481</p> <p>ClinicalTrials.gov <a href="http://www.clinicaltrials.gov/ct2/show/NCT00810329">NCT00810329</a></p

    Search for a Technicolor omega_T Particle in Events with a Photon and a b-quark Jet at CDF

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    If the Technicolor omega_T particle exists, a likely decay mode is omega_T -> gamma pi_T, followed by pi_T -> bb-bar, yielding the signature gamma bb-bar. We have searched 85 pb^-1 of data collected by the CDF experiment at the Fermilab Tevatron for events with a photon and two jets, where one of the jets must contain a secondary vertex implying the presence of a b quark. We find no excess of events above standard model expectations. We express the result of an exclusion region in the M_omega_T - M_pi_T mass plane.Comment: 14 pages, 2 figures. Available from the CDF server (PS with figs): http://www-cdf.fnal.gov/physics/pub98/cdf4674_omega_t_prl_4.ps FERMILAB-PUB-98/321-

    Measurement of the B0 anti-B0 oscillation frequency using l- D*+ pairs and lepton flavor tags

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    The oscillation frequency Delta-md of B0 anti-B0 mixing is measured using the partially reconstructed semileptonic decay anti-B0 -> l- nubar D*+ X. The data sample was collected with the CDF detector at the Fermilab Tevatron collider during 1992 - 1995 by triggering on the existence of two lepton candidates in an event, and corresponds to about 110 pb-1 of pbar p collisions at sqrt(s) = 1.8 TeV. We estimate the proper decay time of the anti-B0 meson from the measured decay length and reconstructed momentum of the l- D*+ system. The charge of the lepton in the final state identifies the flavor of the anti-B0 meson at its decay. The second lepton in the event is used to infer the flavor of the anti-B0 meson at production. We measure the oscillation frequency to be Delta-md = 0.516 +/- 0.099 +0.029 -0.035 ps-1, where the first uncertainty is statistical and the second is systematic.Comment: 30 pages, 7 figures. Submitted to Physical Review

    Search for New Particles Decaying to top-antitop in proton-antiproton collisions at squareroot(s)=1.8 TeV

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    We use 106 \ipb of data collected with the Collider Detector at Fermilab to search for narrow-width, vector particles decaying to a top and an anti-top quark. Model independent upper limits on the cross section for narrow, vector resonances decaying to \ttbar are presented. At the 95% confidence level, we exclude the existence of a leptophobic \zpr boson in a model of topcolor-assisted technicolor with mass M_{\zpr} << 480 \gev for natural width Γ\Gamma = 0.012 M_{\zpr}, and M_{\zpr} << 780 \gev for Γ\Gamma = 0.04 M_{\zpr}.Comment: The CDF Collaboration, submitted to PRL 25-Feb-200

    Double Diffraction Dissociation at the Fermilab Tevatron Collider

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    We present results from a measurement of double diffraction dissociation in pˉp\bar pp collisions at the Fermilab Tevatron collider. The production cross section for events with a central pseudorapidity gap of width Δη0>3\Delta\eta^0>3 (overlapping η=0\eta=0) is found to be 4.43±0.02(stat)±1.18(syst)mb4.43\pm 0.02{(stat)}{\pm 1.18}{(syst) mb} [3.42±0.01(stat)±1.09(syst)mb3.42\pm 0.01{(stat)}{\pm 1.09}{(syst) mb}] at s=1800\sqrt{s}=1800 [630] GeV. Our results are compared with previous measurements and with predictions based on Regge theory and factorization.Comment: 10 pages, 4 figures, using RevTeX. Submitted to Physical Review Letter

    Search for Gluinos and Scalar Quarks in ppˉp\bar{p} Collisions at s=1.8\sqrt{s}=1.8 TeV using the Missing Energy plus Multijets Signature

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    We have performed a search for gluinos (\gls) and squarks (\sq) in a data sample of 84 pb1^{-1} of \ppb collisions at s\sqrt{s} = 1.8 TeV, recorded by the Collider Detector at Fermilab, by investigating the final state of large missing transverse energy and 3 or more jets, a characteristic signature in R-parity-conserving supersymmetric models. The analysis has been performed `blind', in that the inspection of the signal region is made only after the predictions from Standard Model backgrounds have been calculated. Comparing the data with predictions of constrained supersymmetric models, we exclude gluino masses below 195 \gev (95% C.L.), independent of the squark mass. For the case \msq \approx \mgls, gluino masses below 300 \gev are excluded.Comment: 7 pages, 3 figure

    Diffractive Dijet Production at sqrt(s)=630 and 1800 GeV at the Fermilab Tevatron

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    We report a measurement of the diffractive structure function FjjDF_{jj}^D of the antiproton obtained from a study of dijet events produced in association with a leading antiproton in pˉp\bar pp collisions at s=630\sqrt s=630 GeV at the Fermilab Tevatron. The ratio of FjjDF_{jj}^D at s=630\sqrt s=630 GeV to FjjDF_{jj}^D obtained from a similar measurement at s=1800\sqrt s=1800 GeV is compared with expectations from QCD factorization and with theoretical predictions. We also report a measurement of the ξ\xi (xx-Pomeron) and β\beta (xx of parton in Pomeron) dependence of FjjDF_{jj}^D at s=1800\sqrt s=1800 GeV. In the region 0.035<ξ<0.0950.035<\xi<0.095, t<1|t|<1 GeV2^2 and β<0.5\beta<0.5, FjjD(β,ξ)F_{jj}^D(\beta,\xi) is found to be of the form β1.0±0.1ξ0.9±0.1\beta^{-1.0\pm 0.1} \xi^{-0.9\pm 0.1}, which obeys β\beta-ξ\xi factorization.Comment: LaTeX, 9 pages, Submitted to Phys. Rev. Letter

    A Study of B0 -> J/psi K(*)0 pi+ pi- Decays with the Collider Detector at Fermilab

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    We report a study of the decays B0 -> J/psi K(*)0 pi+ pi-, which involve the creation of a u u-bar or d d-bar quark pair in addition to a b-bar -> c-bar(c s-bar) decay. The data sample consists of 110 1/pb of p p-bar collisions at sqrt{s} = 1.8 TeV collected by the CDF detector at the Fermilab Tevatron collider during 1992-1995. We measure the branching ratios to be BR(B0 -> J/psi K*0 pi+ pi-) = (8.0 +- 2.2 +- 1.5) * 10^{-4} and BR(B0 -> J/psi K0 pi+ pi-) = (1.1 +- 0.4 +- 0.2) * 10^{-3}. Contributions to these decays are seen from psi(2S) K(*)0, J/psi K0 rho0, J/psi K*+ pi-, and J/psi K1(1270)

    Dual Beneficial Effects of (-)-Epigallocatechin-3-Gallate on Levodopa Methylation and Hippocampal Neurodegeneration: In Vitro and In Vivo Studies

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    A combination of levodopa (L-DOPA) and carbidopa is the most commonly-used treatment for symptom management in Parkinson's disease. Studies have shown that concomitant use of a COMT inhibitor is highly beneficial in controlling the wearing-off phenomenon by improving L-DOPA bioavailability as well as brain entry. The present study sought to determine whether (-)-epigallocatechin-3-gallate (EGCG), a common tea polyphenol, can serve as a naturally-occurring COMT inhibitor that also possesses neuroprotective actions.Using both in vitro and in vivo models, we investigated the modulating effects of EGCG on L-DOPA methylation as well as on chemically induced oxidative neuronal damage and degeneration. EGCG strongly inhibited human liver COMT-mediated O-methylation of L-DOPA in a concentration-dependent manner in vitro, with an average IC50 of 0.36 microM. Oral administration of EGCG moderately lowered the accumulation of 3-O-methyldopa in the plasma and striatum of rats treated with L-DOPA+carbidopa. In addition, EGCG also reduced glutamate-induced oxidative cytotoxicity in cultured HT22 mouse hippocampal neuronal cells through inactivation of the nuclear factor kappaB-signaling pathway. Under in vivo conditions, administration of EGCG exerted a strong protective effect against kainic acid-induced oxidative neuronal death in the hippocampus of rats.These observations suggest that oral administration of EGCG may have significant beneficial effects in Parkinson's patients treated with L-DOPA and carbidopa by exerting a modest inhibition of L-DOPA methylation plus a strong neuroprotection against oxidative damage and degeneration
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