Is Clopidogrel Premedication Useful to Reduce Thromboembolic Events During Coil Embolization for Unruptured Intracranial Aneurysms?

BACKGROUND:

Thromboembolism is a common complication related to coil embolization of intracranial aneurysms.

OBJECTIVE:

To identify factors related to thromboembolic events during coil embolization for unruptured intracranial aneurysms and to evaluate the role of clopidogrel premedication to prevent thromboembolisms.

METHODS:

Since March 2006, clopidogrel has been administered to patients with unruptured aneurysms before coil embolization (the clopidogrel group) in our institution. The clopidogrel group (416 patients with 485 aneurysms) and the historical control group (140 patients with 159 aneurysms who received no antiplatelet premedication) were compared to find the efficacy of clopidogrel premedication. Various factors, including age, sex, body weight, and medical history of hypertension, diabetes mellitus, hyperlipidemia, smoking, previous stroke, and heart disease, as well as clopidogrel premedication, were analyzed in relationship to the development of a procedure-related thromboembolism.

RESULTS:

Procedure-related thromboembolic events tended to occur less frequently in the clopidogrel group compared with the control group (7.4% vs 12.6%; P = .05), and clopidogrel premedication could modify the risk in female patients from 11.1% to 5.2% (P = .04). The use of multiple logistic regression analysis identified clopidogrel premedication (P = .03), smoking (P = .002), and hyperlipidemia (P = .02) as significant factors related to the formation of thromboembolism.

CONCLUSION:

Clopidogrel premedication seems to have a beneficial effect in reducing the number of procedure-related thromboembolisms during coil embolization for unruptured intracranial aneurysms, especially in female patients. Smoking and hyperlipidemia were independent risk factors related to thromboembolism.

Properties of HTLV-I transformed CD8+ T-cells in response to HIV-1 infection

HIV-1 infection studies of primary CD8(+) T-cells are hampered by difficulty in obtaining a significant number of targets for infection and low levels of productive infection. Further, there exists a paucity of CD8-expressing T-cell lines to address questions pertaining to the study of CD8(+) T-cells in the context of HIV-1 infection. In this study, a set of CD8(+) T-cell clones were originated through HTLV-I transformation in vitro, and the properties of these cells were examined. The clones were susceptible to T-cell tropic strains of the virus and exhibited HIV-1 production 20-fold greater than primary CD4(+) T-cells. Productive infection resulted in a decrease in expression of CD8 and CXCR4 molecules on the surface of the CD8(+) T-cell clones and antibodies to these molecules abrogated viral binding and replication. These transformed cells provide an important tool in the study of CD8(+) T-cells and may provide important insights into the mechanism(s) behind HIV-1 induced CD8(+) T-cell dysfunction.

Search for new physics with a dijet plus missing E(T) signature in pp collisions at √s=1.96 TeV

We present results of a signature-based search for new physics using a dijet plus missing transverse energy (E(T)) data sample collected in 2  fb⁻¹ of pp collisions at √s=1.96  TeV with the CDF II detector at the Fermilab Tevatron. We observe no significant event excess with respect to the standard model prediction and extract a 95% C.L. upper limit on the cross section times acceptance for a potential contribution from a nonstandard model process. The search is made by using novel, data-driven techniques for estimating backgrounds that are applicable to first searches at the LHC.

Exclusion of an exotic top quark with -4/3 electric charge using soft lepton tagging

We present a measurement of the electric charge of the top quark using pp collisions corresponding to an integrated luminosity of 2.7 fb(-1) at the CDF II detector. We reconstruct tt events in the lepton + jets final state. We use soft lepton taggers to determine the flavor of the b jets, which we use to reconstruct the top quark's electric charge and exclude an exotic top quark with -4/3 charge at 95% confidence level. This is the strongest exclusion of the exotic charge scenario and the first to use soft leptons for this purpose.

Modified number of extranodal involved sites as a prognosticator in R-CHOP-treated patients with disseminated diffuse large B-cell lymphoma

BACKGROUND/AIMS

Rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone chemotherapy (R-CHOP) has improved survival in patients with diffuse large B-cell lymphoma (DLBCL) and weakened the prognostic power of the international prognostic index (IPI). We evaluated the efficacy of the IPI and revised IPI (R-IPI) in patients with DLBCL who were treated with R-CHOP, focusing on extranodal site number (ENS) because extranodal involvement occurs frequently in Koreans.

METHODS

A total of 126 R-CHOP-treated patients with stage III/IV DLBCL were analyzed. We performed a retrospective analysis of the clinicopathologic factors and verified the predictive power of the standard IPI and R-IPI. Various numbers of extranodal sites were analyzed for further stratification, and we set the extranodal site-modified IPI (E-IPI) as the IPI when the number of extranodal sites was stratified as < 3 vs. ≥ 3.

RESULTS

A univariate analysis showed that ENS was associated with complete response (CR, p = 0.04), event-free survival (EFS, p = 0.01), and overall survival (OS, p < 0.001) when the ENS cut-off was set at ≥ 3. A multivariate analysis revealed that an ENS ≥ 3 remained associated with EFS (p < 0.01; hazard ratio [HR], 2.60; 95% confidence interval [CI], 1.29 to 5.26) and OS (p < 0.01; HR, 3.52; 95% CI, 1.68 to 7.35). The IPI was effective for determining prognosis in terms of OS (p = 0.04) but not EFS (p = 0.17). The R-IPI was effective in terms of both variables (p = 0.02 and 0.04, respectively), as was the E-IPI (p = 0.01 and 0.001, respectively).

CONCLUSIONS

An ENS < 3 vs. ≥ 3, rather than the original < 2 vs. ≥ 2, was the most significant prognostic factor for EFS and OS. All three indices were predictive, but only the E-IPI identified the high-risk group of R-CHOP-treated Korean patients with disseminated DLBCL.

Search for the production of scalar bottom quarks in pp collisions at square root(s) = 1.96 TeV

We report on a search for direct scalar bottom quark (sbottom) pair production in pp collisions at square root(s) = 1.96 TeV, in events with large missing transverse energy and two jets of hadrons in the final state, where at least one of the jets is required to be identified as originating from a b quark. The study uses a collider detector at Fermilab Run II data sample corresponding to 2.65 fb(-1) of integrated luminosity. The data are in agreement with the standard model. In an R-parity conserving minimal supersymmetric scenario, and assuming that the sbottom decays exclusively into a bottom quark and a neutralino, 95% confidence-level upper limits on the sbottom pair production cross section of 0.1 pb are obtained. For neutralino masses below 70 GeV/c2, sbottom masses up to 230 GeV/c2 are excluded at 95% confidence level.

Optimal timing of G-CSF administration for effective autologous stem cell collection

The best time of G-CSF administration for PBPC collection remains to be defined. We aimed to identify optimal G-CSF administration timing for efficient autologous stem cell collection. A total of 262 lymphoma or multiple myeloma patients, who underwent PBPC collection from January 2000 to March 2008, were included. PBPCs were mobilized with chemotherapy followed by lenograstim at 10 μg/kg/day. Patients received lenograstim at 2000 hours, about half a day before leukapheresis (PM group) before November 2004, and at 0600 hours, 3 h before apheresis (AM group) subsequently. In the AM group, the median number of total collected CD34+ cells/kg was greater over a shorter duration of apheresis, and the median number of collected CD34+ cells/kg at first leukapheresis was larger. Stem cell collection efficacy (ratio of total collected CD34+ cells/kg per number of leukapheresis procedures) was higher, and proportion of patients who yielded an optimum harvest was larger. The statistically significant between-group difference was observed only in patients with high-dose CY chemotherapy for stem cell mobilization in subgroup analysis. The present study showed that G-CSF injection 3 h before apheresis improved the efficacy of autologous stem cell collection.

Measurement of W-boson polarization in Top-Quark Decay in pp collisions at sqrt[s]=1.96 TeV

We report measurements of the polarization of W bosons from top-quark decays using 2.7 fb{-1} of pp collisions collected by the CDF II detector. Assuming a top-quark mass of 175  GeV/c{2}, three measurements are performed. A simultaneous measurement of the fraction of longitudinal (f{0}) and right-handed (f{+}) W bosons yields the model-independent results f{0}=0.88±0.11(stat)±0.06(syst) and f{+}=-0.15±0.07(stat)±0.06(syst) with a correlation coefficient of -0.59. A measurement of f{0} [f{+}] constraining f{+} [f{0}] to its standard model value of 0.0 [0.7] yields f{0}=0.70±0.07(stat)±0.04(syst) [f{+}=-0.01±0.02(stat)±0.05(syst)]. All these results are consistent with standard model expectations. We achieve the single most precise measurements of f{0} for both the model-independent and model-dependent determinations.

First measurement of Bose-Einstein correlations in proton-proton collisions at √s=0.9 and 2.36 TeV at the LHC

Bose-Einstein correlations have been measured using samples of proton-proton collisions at 0.9 and 2.36 TeV center-of-mass energies, recorded by the CMS experiment at the CERN Large Hadron Collider. The signal is observed in the form of an enhancement of pairs of same-sign charged particles with small relative four-momentum. The size of the correlated particle emission region is seen to increase significantly with the particle multiplicity of the event.

Transverse-momentum and pseudorapidity distributions of charged hadrons in pp collisions at square root of s = 7 TeV

Charged-hadron transverse-momentum and pseudorapidity distributions in proton-proton collisions at square root of s = 7  TeV are measured with the inner tracking system of the CMS detector at the LHC. The charged-hadron yield is obtained by counting the number of reconstructed hits, hit pairs, and fully reconstructed charged-particle tracks. The combination of the three methods gives a charged-particle multiplicity per unit of pseudorapidity dN(ch)/dη|(|η|<0.5) = 5.78 ± 0.01(stat) ± 0.23(syst) for non-single-diffractive events, higher than predicted by commonly used models. The relative increase in charged-particle multiplicity from square root of s = 0.9 to 7 TeV is [66.1 ± 1.0(stat) ± 4.2(syst)]%. The mean transverse momentum is measured to be 0.545 ± 0.005(stat) ± 0.015(syst)  GeV/c. The results are compared with similar measurements at lower energies.

Measurement of the ratio σ{tt}/σ{Z/γ{*}→ll} and precise extraction of the tt cross section

We report a measurement of the ratio of the tt to Z/γ{*} production cross sections in sqrt[s]=1.96  TeV pp collisions using data corresponding to an integrated luminosity of up to 4.6  fb{-1}, collected by the CDF II detector. The tt cross section ratio is measured using two complementary methods, a b-jet tagging measurement and a topological approach. By multiplying the ratios by the well-known theoretical Z/γ{*}→ll cross section predicted by the standard model, the extracted tt cross sections are effectively insensitive to the uncertainty on luminosity. A best linear unbiased estimate is used to combine both measurements with the result σ{tt}=7.70±0.52  pb, for a top-quark mass of 172.5  GeV/c{2}.

Shaping and Navigating Methods of Microcatheters for Endovascular Treatment of Paraclinoid Aneurysms

OBJECTIVE

To determine whether the use of a specific shape and a navigating method of microcatheters are suitable for placement at paraclinoid aneurysms.

METHODS

The clinical data from 122 patients with 132 paraclinoid aneurysms that underwent endovascular treatments during a 2.5-year period were retrospectively reviewed. Microcatheter shapes were classified as “straight,” “primary curves” (45, 90, and J), “preshaped-C,” “pigtail” (simple, right, and left), and “S” (simple, right, left, and preshaped). The navigating methods were classified as antegrade/retrograde microcatheter shift, wire-steering, looping, and coil/wire guiding. The shapes and navigating methods were compared among 3 aneurysm groups, which were categorized as superior, medial, and other, based on direction.

RESULTS

Shapes were significantly different between the 3 groups; the most commonly engaged shape in the superior group, medial group, and other group was S (55%), pigtail (60%), and primary (56%), respectively. The straight and S shapes were used in 5 (83%) and 18 (86%) cases, respectively, in the superior group, whereas the pigtail shape was used in 50 (86%) cases in the medial group. Aside from pigtail-simple shape, the side of pigtail, right vs left, coincided with the side of the internal carotid artery involved in every case of the medial group. The navigating methods were not significantly different among the 3 groups.

CONCLUSION

A specific shape by paraclinoid aneurysm direction tends to be suitable for the first trial of microcatheter shapes. Operators may reduce unnecessary struggling time of intra-aneurysmal placement of microcatheters by practicing the use of that shape.

Search for pair production of supersymmetric top quarks in dilepton events from pp collisions at sqrt[s]=1.96 TeV

We present the results of a search for pair production of the supersymmetric partner of the top quark (the top squark t{1}) decaying to a b quark and a chargino χ{1}{±} with a subsequent χ{1}{±} decay into a neutralino χ{1}{0}, lepton ℓ, and neutrino ν. Using a data sample corresponding to 2.7  fb{-1} of integrated luminosity of pp collisions at sqrt[s]=1.96  TeV collected by the CDF II detector, we reconstruct the mass of top squark candidate events and fit the observed mass spectrum to a combination of standard model processes and t{1}t{1} signal. We find no evidence for t{1}t{1} production and set 95% C.L. limits on the masses of the top squark and the neutralino for several values of the chargino mass and the branching ratio B(χ{1}{±}→χ{1}{0}ℓ{±}ν).

Search for WW and WZ resonances decaying to electron, missing E(T), and two jets in pp collisions at square root(s) = 1.96 TeV

Using data from 2.9  fb(-1) of integrated luminosity collected with the CDF II detector at the Tevatron, we search for resonances decaying into a pair of on-shell gauge bosons, WW or WZ, where one W decays into an electron and a neutrino, and the other boson decays into two jets. We observed no statistically significant excess above the expected standard model background, and we set cross section limits at 95% confidence level on G* (Randall-Sundrum graviton), Z', and W' bosons. By comparing these limits to theoretical cross sections, mass exclusion regions for the three particles are derived. The mass exclusion regions for Z' and W' are further evaluated as a function of their gauge coupling strength.

Immunoglobulin G subclass deficiency is the major phenotype of primary immunodeficiency in a Korean adult cohort

Primary immunodeficiency disease (PID) is a rare disorder in adults. Most often, serious forms are detected during infancy or childhood. However, mild forms of PID may not be diagnosed until later in life, and some types of humoral immunodeficiency may occur in adulthood. The purpose of this study was to identify clinical features of PID in Korean adults. A retrospective study was performed on 55 adult patients who were diagnosed as PID between January 1998 and January 2009 at a single tertiary medical center in Korea. IgG subclass deficiency was the most common phenotype (67%, 37/55), followed by total IgG deficiency (20%, 11/55), IgM deficiency (7%, 4/55), common variable immunodeficiency (2%, 1/55), and X-linked agammaglobulinemia (2%, 1/55). IgG3 and IgG4 were the most affected subclasses. Upper and lower respiratory tract infections (76%) were the most frequently observed symptoms, followed by multiple site infection (11%), urinary tract infection, and colitis. Bronchial asthma, rhinitis, and several autoimmune diseases were common associated diseases. IgG and IgG subclass deficiency should be considered in adult patients presenting with recurrent upper and lower respiratory infections, particularly in those with respiratory allergies or autoimmune diseases.

Formation of a three-dimensional network of V trimers in A2V13O22 (A=Ba, Sr)

We found that in A2V13O22 (A=Ba, Sr), which contains a trilayer slab of VO in the sodium-chloride structure with periodically missing ions, the trimerization of V ions occurs at 290 K (A=Ba) and 380 K (A=Sr). V trimers form a three-dimensional network, but some V ions remain untrimerized in these compounds. The suppression of magnetic susceptibility with trimerization and the existence of a Curie tail at low temperatures, together with the result of NMR measurement, indicate that the V trimers are spin singlet, whereas the untrimerized V ions have a magnetic moment; i.e., there is a spontaneous separation between nonmagnetic and magnetic ions in the crystal.

Measurement of the W+ W- production cross section and search for anomalous WWγ and WWZ couplings in pp collisions at square root(s)=1.96 TeV

This Letter describes the current most precise measurement of the W boson pair production cross section and most sensitive test of anomalous WWγ and WWZ couplings in pp collisions at a center-of-mass energy of 1.96 TeV. The WW candidates are reconstructed from decays containing two charged leptons and two neutrinos. Using data collected by the CDF II detector from 3.6  fb(-1) of integrated luminosity, a total of 654 candidate events are observed with an expected background of 320±47 events. The measured cross section is σ(pp→W+ W- +X)=12.1±0.9(stat)-1.4+1.6(syst)  pb, which is in good agreement with the standard model prediction. The same data sample is used to place constraints on anomalous WWγ and WWZ couplings.

Increased prevalence of white matter hyperintensities in patients with panic disorder

The aim of the current study is to compare the prevalence, severity and location of cerebral white matter hyperintensities (WMH) between patients with panic disorder (PD) and healthy control subjects. Patients with PD (n = 24) and matched healthy control subjects (n = 24) were scanned using a 3.0 Tesla whole-body magnetic resonance scanner. Axial T2-weighted and fluid-attenuated inversion recovery images were acquired and evaluated for the prevalence, severity and location of WMH using the modified composite scale of Fazekas and Coffey and coded separately for deep and periventricular WMH. Logistic regression analyses were used to assess the association between WMH and the diagnosis of PD. A greater severity of total WMH was associated with a diagnosis of PD in a dose-dependent pattern (odds ratio [OR] = 8.8, P = 0.005 for mild WMH; OR = 27.7, P = 0.007 for moderate to severe WMH). Deep WMH, where most group differences originated, were predominantly located in the frontal region of the brain (n = 16 in PD, n = 1 in control). The current report is the first study to report an increased prevalence of WMH in patients with PD.

Search for the Higgs boson using neural networks in events with missing energy and b-quark jets in pp collisions at square root(s) = 1.96 TeV

We report on a search for the standard model Higgs boson produced in association with a W or Z boson in pp collisions at square root(s)=1.96 TeV recorded by the CDF II experiment at the Tevatron in a data sample corresponding to an integrated luminosity of 2.1 fb(-1). We consider events which have no identified charged leptons, an imbalance in transverse momentum, and two or three jets where at least one jet is consistent with originating from the decay of a b hadron. We find good agreement between data and background predictions. We place 95% confidence level upper limits on the production cross section for several Higgs boson masses ranging from 110 GeV/c(2) to 150 GeV/c(2). For a mass of 115 GeV/c(2) the observed (expected) limit is 6.9 (5.6) times the standard model prediction.

First measurement of the b-jet cross section in events with a W boson in pp collisions at square root(s) = 1.96 TeV

The cross section for jets from b quarks produced with a W boson has been measured in pp collision data from 1.9 fb(-1) of integrated luminosity recorded by the CDF II detector at the Tevatron. The W+b-jets process poses a significant background in measurements of top quark production and prominent searches for the Higgs boson. We measure a b-jet cross section of 2.74+/-0.27(stat)+/-0.42(syst) pb in association with a single flavor of leptonic W boson decay over a limited kinematic phase space. This measured result cannot be accommodated in several available theoretical predictions.

Search for technicolor particles produced in association with a W Boson at CDF

We present a search for the technicolor particles rho{T} and pi_{T} in the process pp-->rho{T}-->Wpi{T} at a center of mass energy of sqrt[s]=1.96 TeV. The search uses a data sample corresponding to approximately 1.9 fb{-1} of integrated luminosity accumulated by the CDF II detector at the Fermilab Tevatron. The event signature we consider is W-->lnu and pi{T}-->bb, bc or bu depending on the pi{T} charge. We select events with a single high-p{T} electron or muon, large missing transverse energy, and two jets. Jets corresponding to bottom quarks are identified with multiple b-tagging algorithms. The observed number of events and the invariant mass distributions are consistent with the standard model background expectations, and we exclude a region at 95% confidence level in the rho{T}-pi{T} mass plane. As a result, a large fraction of the region m(rho{T})=180-250 GeV/c{2} and m(pi{T})=95-145 GeV/c{2} is excluded.

Measurement of the Lambdab0 lifetime in Lambdab0 --> Lambdac+pi- decays in pp collisions at square root of s = 1.96 TeV

We report a measurement of the lifetime of the Lambda(b)(0) baryon in decays to the Lambda(c)(+)pi(-) final state in a sample corresponding to 1.1 fb(-1) collected in pp collisions at square root of s = 1.96 TeV by the CDF II detector at the Tevatron collider. Using a sample of about 3000 fully reconstructed Lambda(b)(0) events we measure tau(Lambda(b)(0)) = 1.401 +/- 0.046(stat) +/- 0.035(syst) ps (corresponding to ctau(Lambda(b)(0)) = 420.1 +/- 13.7(stat) +/- 10.6(syst) microm, where c is the speed of light). The ratio of this result and the world average B(0) lifetime yields tau(Lambda(b)(0))/tau(B(0)) = 0.918 +/- 0.038 (stat) and (syst), in good agreement with recent theoretical predictions.