Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 57
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Phys Rev Lett ; 127(17): 171801, 2021 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-34739288

RESUMO

Using a dataset of 6.32 fb^{-1} of e^{+}e^{-} annihilation data collected with the BESIII detector at center-of-mass energies between 4178 and 4226 MeV, we have measured the absolute branching fraction of the leptonic decay D_{s}^{+}→τ^{+}ν_{τ} via τ^{+}→e^{+}ν_{e}ν[over ¯]_{τ}, and find B_{D_{s}^{+}→τ^{+}ν_{τ}}=(5.27±0.10±0.12)×10^{-2}, where the first uncertainty is statistical and the second is systematic. The precision is improved by a factor of 2 compared to the previous best measurement. Combining with f_{D_{s}^{+}} from lattice quantum chromodynamics calculations or the |V_{cs}| from the CKMfitter group, we extract |V_{cs}|=0.978±0.009±0.012 and f_{D_{s}^{+}}=(251.1±2.4±3.0) MeV, respectively. Combining our result with the world averages of B_{D_{s}^{+}→τ^{+}ν_{τ}} and B_{D_{s}^{+}→µ^{+}ν_{µ}}, we obtain the ratio of the branching fractions B_{D_{s}^{+}→τ^{+}ν_{τ}}/B_{D_{s}^{+}→µ^{+}ν_{µ}}=9.72±0.37, which is consistent with the standard model prediction of lepton flavor universality.

2.
Phys Rev Lett ; 127(12): 121802, 2021 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-34597097

RESUMO

The absolute branching fraction of Λ→pµ^{-}ν[over ¯]_{µ} is reported for the first time based on an e^{+}e^{-} annihilation sample of 10×10^{9} J/ψ events collected with the BESIII detector at sqrt[s]=3.097 GeV. The branching fraction is determined to be B(Λ→pµ^{-}ν[over ¯]_{µ})=[1.48±0.21(stat)±0.08(syst)]×10^{-4}, which is improved by about 30% in precision over the previous indirect measurements. Combining this result with the world average of B(Λ→pe^{-}ν[over ¯]_{e}), we obtain the ratio {[Γ(Λ→pµ^{-}ν[over ¯]_{µ})]/[Γ(Λ→pe^{-}ν[over ¯]_{e})]} to be 0.178±0.028, which agrees with the standard model prediction assuming lepton flavor universality. The asymmetry of the branching fractions of Λ→pµ^{-}ν[over ¯]_{µ} and Λ[over ¯]→p[over ¯]µ^{+}ν_{µ} is also determined, and no evidence for CP violation is found.

3.
Phys Rev Lett ; 127(13): 131801, 2021 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-34623854

RESUMO

Using 2.93 fb^{-1} of e^{+}e^{-} collision data taken with the BESIII detector at a center-of-mass energy of 3.773 GeV, the observation of the D^{0}→K_{1}(1270)^{-}e^{+}ν_{e} semileptonic decay is presented. The statistical significance of the decay D^{0}→K_{1}(1270)^{-}e^{+}ν_{e} is greater than 10σ. The branching fraction of D^{0}→K_{1}(1270)^{-}e^{+}ν_{e} is measured to be (1.09±0.13_{-0.16}^{+0.09}±0.12)×10^{-3}. Here, the first uncertainty is statistical, the second is systematic, and the third originates from the assumed branching fraction of K_{1}(1270)^{-}→K^{-}π^{+}π^{-}. The fraction of longitudinal polarization in D^{0}→K_{1}(1270)^{-}e^{+}ν_{e} is determined for the first time to be 0.50±0.19_{stat}±0.08_{syst}.

4.
Phys Rev Lett ; 127(8): 082002, 2021 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-34477419

RESUMO

We report a measurement of the observed cross sections of e^{+}e^{-}→J/ψX based on 3.21 fb^{-1} of data accumulated at energies from 3.645 to 3.891 GeV with the BESIII detector operated at the BEPCII collider. In analysis of the cross sections, we measured the decay branching fractions of B(ψ(3686)→J/ψX)=(64.4±0.6±1.6)% and B(ψ(3770)→J/ψX)=(0.5±0.2±0.1)% for the first time. The energy-dependent line shape of these cross sections cannot be well described by two Breit-Wigner (BW) amplitudes of the expected decays ψ(3686)→J/ψX and ψ(3770)→J/ψX. Instead, it can be better described with one more BW amplitude of the decay R(3760)→J/ψX. Under this assumption, we extracted the R(3760) mass M_{R(3760)}=3766.2±3.8±0.4 MeV/c^{2} , total width Γ_{R(3760)}^{tot}=22.2±5.9±1.4 MeV, and product of leptonic width and decay branching fraction Γ_{R(3760)}^{ee}B[R(3760)→J/ψX]=(79.4±85.5±11.7) eV. The significance of the R(3760) is 5.3σ. The first uncertainties of these measured quantities are from fits to the cross sections and second systematic.

5.
Phys Rev Lett ; 126(9): 092002, 2021 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-33750166

RESUMO

We present an analysis of the process ψ(3686)→Ω^{-}Ω[over ¯]^{+} (Ω^{-}→K^{-}Λ, Ω[over ¯]^{+}→K^{+}Λ[over ¯], Λ→pπ^{-}, Λ[over ¯]→p[over ¯]π^{+}) based on a dataset of 448×10^{6} ψ(3686) decays collected with the BESIII detector at the BEPCII electron-positron collider. The helicity amplitudes for the process ψ(3686)→Ω^{-}Ω[over ¯]^{+} and the decay parameters of the subsequent decay Ω^{-}→K^{-}Λ (Ω[over ¯]^{+}→K^{+}Λ[over ¯]) are measured for the first time by a fit to the angular distribution of the complete decay chain, and the spin of the Ω^{-} is determined to be 3/2 for the first time since its discovery more than 50 years ago.

6.
Phys Rev Lett ; 126(10): 102001, 2021 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-33784133

RESUMO

We report a study of the processes of e^{+}e^{-}→K^{+}D_{s}^{-}D^{*0} and K^{+}D_{s}^{*-}D^{0} based on e^{+}e^{-} annihilation samples collected with the BESIII detector operating at BEPCII at five center-of-mass energies ranging from 4.628 to 4.698 GeV with a total integrated luminosity of 3.7 fb^{-1}. An excess of events over the known contributions of the conventional charmed mesons is observed near the D_{s}^{-}D^{*0} and D_{s}^{*-}D^{0} mass thresholds in the K^{+} recoil-mass spectrum for events collected at sqrt[s]=4.681 GeV. The structure matches a mass-dependent-width Breit-Wigner line shape, whose pole mass and width are determined as (3982.5_{-2.6}^{+1.8}±2.1) MeV/c^{2} and (12.8_{-4.4}^{+5.3}±3.0) MeV, respectively. The first uncertainties are statistical and the second are systematic. The significance of the resonance hypothesis is estimated to be 5.3 σ over the contributions only from the conventional charmed mesons. This is the first candidate for a charged hidden-charm tetraquark with strangeness, decaying into D_{s}^{-}D^{*0} and D_{s}^{*-}D^{0}. However, the properties of the excess need further exploration with more statistics.

7.
Phys Rev Lett ; 125(14): 141802, 2020 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-33064551

RESUMO

Using 2.93 fb^{-1} of e^{+}e^{-} collision data collected at a center-of-mass energy of 3.773 GeV with the BESIII detector, the first observation of the doubly Cabibbo-suppressed decay D^{+}→K^{+}π^{+}π^{-}π^{0} is reported. After removing decays that contain narrow intermediate resonances, including D^{+}→K^{+}η, D^{+}→K^{+}ω, and D^{+}→K^{+}ϕ, the branching fraction of the decay D^{+}→K^{+}π^{+}π^{-}π^{0} is measured to be (1.13±0.08_{stat}±0.03_{syst})×10^{-3}. The ratio of branching fractions of D^{+}→K^{+}π^{+}π^{-}π^{0} over D^{+}→K^{-}π^{+}π^{+}π^{0} is found to be (1.81±0.15)%, which corresponds to (6.28±0.52)tan^{4}θ_{C}, where θ_{C} is the Cabibbo mixing angle. This ratio is significantly larger than the corresponding ratios for other doubly Cabibbo-suppressed decays. The asymmetry of the branching fractions of charge-conjugated decays D^{±}→K^{±}π^{±}π^{∓}π^{0} is also determined, and no evidence for CP violation is found. In addition, the first evidence for the D^{+}→K^{+}ω decay, with a statistical significance of 3.3σ, is presented and the branching fraction is measured to be B(D^{+}→K^{+}ω)=(5.7_{-2.1}^{+2.5}_{stat}±0.2_{syst})×10^{-5}.

8.
Phys Rev Lett ; 125(5): 052004, 2020 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-32794879

RESUMO

From 1310.6×10^{6} J/ψ and 448.1×10^{6} ψ(3686) events collected with the BESIII experiment, we report the first observation of Σ^{+} and Σ[over ¯]^{-} spin polarization in e^{+}e^{-}→J/ψ[ψ(3686)]→Σ^{+}Σ[over ¯]^{-} decays. The relative phases of the form factors ΔΦ have been measured to be (-15.5±0.7±0.5)° and (21.7±4.0±0.8)° with J/ψ and ψ(3686) data, respectively. The nonzero value of ΔΦ allows for a direct and simultaneous measurement of the decay asymmetry parameters of Σ^{+}→pπ^{0}(α_{0}=-0.998±0.037±0.009) and Σ[over ¯]^{-}→p[over ¯]π^{0}(α[over ¯]_{0}=0.990±0.037±0.011), the latter value being determined for the first time. The average decay asymmetry, (α_{0}-α[over ¯]_{0})/2, is calculated to be -0.994±0.004±0.002. The CP asymmetry A_{CP,Σ}=(α_{0}+α[over ¯]_{0})/(α_{0}-α[over ¯]_{0})=-0.004±0.037±0.010 is extracted for the first time, and is found to be consistent with CP conservation.

9.
Phys Rev Lett ; 124(23): 231801, 2020 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-32603168

RESUMO

By analyzing a data sample corresponding to an integrated luminosity of 2.93 fb^{-1} collected at a center-of-mass energy of 3.773 GeV with the BESIII detector, we measure for the first time the absolute branching fraction of the D^{+}→ηµ^{+}ν_{µ} decay to be B_{D^{+}→ηµ^{+}ν_{µ}}=(10.4±1.0_{stat}±0.5_{syst})×10^{-4}. Using the world averaged value of B_{D^{+}→ηe^{+}ν_{e}}, the ratio of the two branching fractions is determined to be B_{D^{+}→ηµ^{+}ν_{µ}}/B_{D^{+}→ηe^{+}ν_{e}}=0.91±0.13_{(stat+syst)}, which agrees with the theoretical expectation of lepton flavor universality within uncertainty. By studying the differential decay rates in five four-momentum transfer intervals, we obtain the product of the hadronic form factor f_{+}^{η}(0) and the c→d Cabibbo-Kobayashi-Maskawa matrix element |V_{cd}| to be f_{+}^{η}(0)|V_{cd}|=0.087±0.008_{stat}±0.002_{syst}. Taking the input of |V_{cd}| from the global fit in the standard model, we determine f_{+}^{η}(0)=0.39±0.04_{stat}±0.01_{syst}. On the other hand, using the value of f_{+}^{η}(0) calculated in theory, we find |V_{cd}|=0.242±0.022_{stat}±0.006_{syst}±0.033_{theory}.

10.
Phys Rev Lett ; 124(24): 242001, 2020 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-32639837

RESUMO

The processes X(3872)→D^{*0}D[over ¯]^{0}+c.c.,γJ/ψ,γψ(2S), and γD^{+}D^{-} are searched for in a 9.0 fb^{-1} data sample collected at center-of-mass energies between 4.178 and 4.278 GeV with the BESIII detector. We observe X(3872)→D^{*0}D^{0}[over ¯]+c.c. and find evidence for X(3872)→γJ/ψ with statistical significances of 7.4σ and 3.5σ, respectively. No evident signals for X(3872)→γψ(2S) and γD^{+}D^{-} are found, and the upper limit on the relative branching ratio R_{γψ}≡{B[X(3872)→γψ(2S)]}/{B[X(3872)→γJ/ψ]}<0.59 is set at 90% confidence level. Measurements of branching ratios relative to decay X(3872)→π^{+}π^{-}J/ψ are also reported for decays X(3872)→D^{*0}D^{0}[over ¯]+c.c.,γψ(2S),γJ/ψ, and γD^{+}D^{-}, as well as the non-D^{*0}D^{0}[over ¯] three-body decays π^{0}D^{0}D^{0}[over ¯] and γD^{0}D^{0}[over ¯].

11.
Phys Rev Lett ; 124(24): 241803, 2020 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-32639841

RESUMO

Using 2.93 fb^{-1} of e^{+}e^{-} collision data taken at a center-of-mass energy of 3.773 GeV with the BESIII detector, we report the first measurements of the absolute branching fractions of 14 hadronic D^{0(+)} decays to exclusive final states with an η, e.g., D^{0}→K^{-}π^{+}η, K_{S}^{0}π^{0}η, K^{+}K^{-}η, K_{S}^{0}K_{S}^{0}η, K^{-}π^{+}π^{0}η, K_{S}^{0}π^{+}π^{-}η, K_{S}^{0}π^{0}π^{0}η, and π^{+}π^{-}π^{0}η; D^{+}→K_{S}^{0}π^{+}η, K_{S}^{0}K^{+}η, K^{-}π^{+}π^{+}η, K_{S}^{0}π^{+}π^{0}η, π^{+}π^{+}π^{-}η, and π^{+}π^{0}π^{0}η. Among these decays, the D^{0}→K^{-}π^{+}η and D^{+}→K_{S}^{0}π^{+}η decays have the largest branching fractions, which are B(D^{0}→K^{-}π^{+}η)=(1.853±0.025_{stat}±0.031_{syst})% and B(D^{+}→K_{S}^{0}π^{+}η)=(1.309±0.037_{stat}±0.031_{syst})%, respectively. The charge-parity asymmetries for the six decays with highest event yields are determined, and no statistically significant charge-parity violation is found.

12.
Clin Oral Investig ; 19(7): 1663-72, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25609032

RESUMO

OBJECTIVES: The aim of the present study was to investigate the clinical effectiveness over 12 weeks of Vertise Flow(™), a self-adhering composite, in dental hypersensitivity (DH). MATERIAL AND METHODS: The study was conducted as a split-mouth randomized clinical trial. Vertise Flow™ was compared to the following: (1) Universal Dentine Sealant, (2) Clearfil Protect Bond, and (3) Flor-Opal® Varnish. A total of 46 patients with 116 hypersensitive teeth were studied. Pain experience was generated by a cold stimulus and assessed using the visual analog scale (VAS) of pain. The response was recorded before the application of the materials (pre-1), immediately after (post-1), at 1- (post-2), 2- (post-3), and 12-week controls (post-4). Statistical differences in VAS were performed using the Kruskal-Wallis analysis at the different time-points (P < 0.05), adjusting statistical significances for multiple comparisons (Bonferroni correction). RESULTS: All the materials showed any statistically significant differences at the baseline. After the application of each material, a VAS decrease was demonstrated at every post-control. VF showed significant hypersensitivity reduction in post-1. Statistically significant relief was also observed in post-2 while no significant differences were detected in post-3 and post-4. CONCLUSIONS: After 12-week controls, there was no statistically significant hypersensitivity reduction using VF in respect to the other materials. On the other hand, any significant differences were detected in the decrease of the VAS irrespective of the desensitizing agent employed at the 12-week controls. CLINICAL RELEVANCE: The significant increase in VAS scores within the 12-weeks of environment suggested there is instability of VF when used as desensitizing agent.


Assuntos
Cimentos Dentários/uso terapêutico , Sensibilidade da Dentina/etiologia , Feminino , Humanos , Masculino , Resultado do Tratamento
13.
Endocrinology ; 153(12): 5770-81, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23077074

RESUMO

Increased apoptosis of cardiac progenitor cells (CPCs) has been proposed as a mechanism of myocardial damage and dysfunction. Glucagon-like peptide-1 (GLP-1) has been shown to improve heart recovery and function after ischemia and to promote cell survival. The protective effects of GLP-1 on oxidative stress-induced apoptosis were investigated in human CPCs isolated from human heart biopsies. Mesenchymal-type cells were isolated from human heart biopsies, exhibited the marker profile of CPCs, differentiated toward the myocardiocyte, adipocyte, chondrocyte, and osteocyte lineages under appropriate culture conditions, and expressed functional GLP-1 receptors. CPCs were incubated with GLP-1 with or without hydrogen peroxide (H(2)O(2)). Phospho- and total proteins were detected by immunoblotting and immunofluorescence analysis. Gene expression was evaluated by quantitative RT-PCR. The role of the canonical GLP-1 receptor was assessed by using the receptor antagonist exendin(9-39) and receptor-specific silencer small interfering RNAs. Cell apoptosis was quantified by an ELISA assay and by flow cytometry-detected Annexin V. Exposure of CPCs to H(2)O(2) induced a 2-fold increase in cell apoptosis, mediated by activation of the c-Jun N-terminal protein kinase (JNK) pathway. Preincubation of CPCs with GLP-1 avoided H(2)O(2)-triggered JNK phosphorylation and nuclear localization, and protected CPCs from apoptosis. The GLP-1 effects were markedly reduced by coincubation with the receptor antagonist exendin(9-39), small interfering RNA-mediated silencing of the GLP-1 receptor, and pretreatment with the protein kinase A inhibitor H89. In conclusion, activation of GLP-1 receptors prevents oxidative stress-mediated apoptosis in human CPCs by interfering with JNK activation and may represent an important mechanism for the cardioprotective effects of GLP-1.


Assuntos
Apoptose , Peptídeo 1 Semelhante ao Glucagon/metabolismo , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Miocárdio/citologia , Estresse Oxidativo , Células-Tronco/citologia , Anexina A5/farmacologia , Biópsia , Diferenciação Celular , Núcleo Celular/metabolismo , Células Cultivadas , Ativação Enzimática , Ensaio de Imunoadsorção Enzimática/métodos , Citometria de Fluxo/métodos , Humanos , Peróxido de Hidrogênio/metabolismo , Proteínas Quinases JNK Ativadas por Mitógeno/antagonistas & inibidores , Modelos Biológicos , Fragmentos de Peptídeos/farmacologia , Fosforilação , RNA Interferente Pequeno/metabolismo , Transdução de Sinais
14.
Minerva Cardioangiol ; 58(4): 425-31, 2010 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-20938409

RESUMO

AIM: Cryptogenic stroke remains the final diagnosis in 40% of ischemic acute cerebrovascular events. Until now there are no clinical evidences that the percutaneous closure of PFO is able to prevent the recurrence of stroke or transient ischemic attack (TIA). The aim of this study was to evaluate the incidence of recurrence in patients successfully treated by percutaneous closure of PFO with different occluder devices by using TCD, TTE and clinical evaluation. METHODS: From February 2004 to November 2009, 72 pts, (40 females and 32 males; average age 46 yrs, range 14-66), admitted with diagnosis of recurrent ischemic neurologic events (58 stroke and 14 TIA) underwent percutaneous closure of PFO. Thirty-one (43%) of the 72 patients had a concomitant history of migraine, 16 (52%) of whom with aura. Five different occluder devices were used, with a total amount of 74 implants. All pts were studied during the follow-up by clinical evaluation (Rankin modified scale), TCD and TTE. RESULTS: Successful device deployment is achieved in 100% of pts without any periprocedural major complication. Only in two pts atrial arrhythmia have occurred. All pts was discharged within 3 days in good overall conditions. In all pts a double antiplatelet regimen was adopted. The follow-up was complete in 100% of the cases (median 30, range 3-58 months ). At five years, there was no recurrent stroke or TIA, and no new cerebral lesions developed by MRI in those patients with residual shunt. Moreover, in 65 (90%) of them the Rankin scale significantly (P<0.0001) reduced to 0 whereas only in 2 pts score 1 was reached. In 19 (61%) of the 31pts with concomitant migraine, the intensity and the frequency of the attacks significantly (P<0.0001) decreased over time. At the TCD, 5 pts (7%) resulted positive for microembolic signals but, only 1 of them, was successfully treated for an associate defect. The TTE evaluation showed however an optimal sealing of all the devices without signs of erosion, incomplete closure and thrombus formation around the device. CONCLUSION: Our experience suggests that percutaneous treatment of PFO is safe and beneficial at the medium term follow-up for secondary prevention since able to prevent the clinical recurrence of acute cerebrovascular events irrespective of the device used.


Assuntos
Forame Oval Patente/cirurgia , Ataque Isquêmico Transitório/etiologia , Dispositivo para Oclusão Septal , Acidente Vascular Cerebral/etiologia , Adolescente , Adulto , Idoso , Ecocardiografia Transesofagiana , Feminino , Seguimentos , Humanos , Ataque Isquêmico Transitório/prevenção & controle , Masculino , Pessoa de Meia-Idade , Transtornos de Enxaqueca/complicações , Prevenção Secundária , Acidente Vascular Cerebral/prevenção & controle , Resultado do Tratamento , Ultrassonografia Doppler Transcraniana , Adulto Jovem
16.
Ann Cardiol Angeiol (Paris) ; 58 Suppl 1: S38-41, 2009 Dec.
Artigo em Francês | MEDLINE | ID: mdl-20103179

RESUMO

In case of persistent and symptomatic atrial fibrillation, a pharmacological cardioversion under effective anticoagulation treatment may be performed according to current guidelines. In the absence of return to sinus rhythm, a Direct-Current cardioversion can be performed. After returning to sinus rhythm will arise the question of anticoagulation and antiarrhythmic drugs treatments that will be most often long-term pursued.


Assuntos
Antiarrítmicos/uso terapêutico , Fibrilação Atrial/terapia , Cardioversão Elétrica , Algoritmos , Humanos
17.
Eur J Paediatr Dent ; 9(3): 149-52, 2008 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-18844445

RESUMO

AIM: Kabuki make-up Syndrome is so named because of the characteristic facies of the affected patient. The face is similar to a Kabuki actor's mask. The main aim of this report was to describe the oral features in Kabuki Syndrome, focusing on the tooth anomalies. PATIENTS AND METHODS: Five subjects with Kabuki Syndrome, identified by the Child Neuropsychiatric Clinic of the University of Sassari, Italy, were enrolled. Their medical records were reviewed and oral and dental examinations were completed. The diagnosis was based upon the typical pattern of malformations and dysmorphic features reviewed by Matsumoto and Niikawa. RESULTS: All patients showed typical characteristics of the Syndrome such as a long palpebral fissure, lower palpebral eversion, arched eyebrows, short nasal septum, prominent and large ears, fingertip pads, mental retardation, and paramedian elevation of the lower lip. CONCLUSION: Kabuki make-up Syndrome is of unknown origin but a genetic aetiopathogenesis has been proposed. It is extremely rare; in Japan, where it is most frequent, it affects 1:32000 newborns. The typical facies of the syndrome, combined with general medical and dental examinations, are very important for diagnosis confirmation.


Assuntos
Face/anormalidades , Anormalidades Dentárias/patologia , Anormalidades Múltiplas , Adolescente , Adulto , Anodontia/patologia , Criança , Hipoplasia do Esmalte Dentário/patologia , Facies , Feminino , Humanos , Masculino , Má Oclusão/patologia , Retrognatismo/patologia , Síndrome
18.
Pacing Clin Electrophysiol ; 30 Suppl 1: S31-3, 2007 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-17302712

RESUMO

BACKGROUND: Besides standard left ventricular (LV) stimulation via the coronary sinus, a transseptal approach allows left ventricular endocardial stimulation. We report our long-term observations with biventricular stimulation, using a strictly endocardial system for patients presenting with severe congestive heart failure. METHODS: Six patients with nonischemic cardiomyopathy (mean age = 60 +/- 9.6 years, women) in New York Heart Association (NYHA) functional class III (n = 5) or IV, despite optimal drug therapy, and a mean LV ejection fraction of 24 +/- 3%, underwent implantation of biventricular stimulation systems between April 1998 and March 1999. All presented with left bundle branch block and an increased LV end-diastolic diameter (mean = 66 +/- 5 mm). In all patients, a bipolar pacing lead was implanted in the lateral LV wall using a direct transseptal approach. After implantation, all patients received oral anticoagulation. RESULTS: QRS duration decreased from 184 +/- 22 ms to 108 +/- 11 ms. NYHA functional class decreased to II in all patients within 1 month. Over a 85 +/- 5 month follow-up, two patients underwent cardiac transplantation, 2 and 4 years after device implantation, respectively; two patients died of end-stage heart failure 4 years after system implantation; and two patients were alive in functional class II. One patient, who experienced syncope due to fast ventricular, underwent implantation of an ICD. One transient ischemic attack occurred in a patient whose anticoagulation was temporarily interrupted. CONCLUSIONS: Long-term endocardial biventricular stimulation via a transseptal approach was safe and effective in this small population. This approach needs to be further compared with conventional epicardial pacing via the coronary sinus.


Assuntos
Estimulação Cardíaca Artificial/métodos , Insuficiência Cardíaca/terapia , Marca-Passo Artificial , Idoso , Bloqueio de Ramo , Feminino , Seguimentos , Septos Cardíacos , Ventrículos do Coração , Humanos , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento
19.
Curr Pharm Des ; 12(10): 1243-8, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-16611106

RESUMO

Hereditary Haemorrhagic Teleangiectasia (HHT) is a vascular disorder of angiogenesis transmitted in an autosomal dominant pattern, characterised by heterogeneity in clinical manifestations. One of the most important organ involved is lung, including pulmonary arteriovenous malformations (PAVM). PAVM occur in 20 to 30% of the HHT population and recently are considered a marker of disease. PAVM are direct artery-to-vein connections with low pressure and without an interveining capillary bed. PAVM are classified as simple (supplied by one feeding artery) or complex (receiving blood supply from two or more feeding artery). According to the international reports, treatment it's recommendable for all PAVM with feeding vessels 3mm or larger, in order to reduce the risk of cerebral ischaemia and neurologic manifestations frequently attributed to paradoxical embolisation. Transcatheter embolotherapy of PAVM is a form of treatment based on occlusion of the feeding artery to a PAVM by using platinum coils or detachable balloons. The technique of coil embolisation involves the exact localisation of PAVM by pulmonary angiography followed by superselective percutaneous caheterisation of feeding artery obtained by using a dedicated 7F guiding catheter, which coaxially allocates a 5F hydrophilic catheter advanced in order to perform both superselective angiography of feeding artery and embolisation itself. Inside the 5F catheter the platinum coils are advanced using a .035'' guide-wire and released until an optimal occlusion of feeding artery is achieved. At the end of the procedure angiographic control is performed in order to verify the occlusion of feeding artery. The use of platinum coils is preferable over detachable balloons when feeding artery are greater than 7 mm in diameter and have irregular anatomical configuration. On the other hand, the principal advantage of using detachable balloons is that the balloon itself can be deflated and repositioned if necessary. Transcatheter embolotherapy is technically safe and clinically effective and may represent the primary choice of treatment in HHT patients. On the other hand the most common complications of this treatment (pleurisy and air embolism) can be prevented by using some tips during the embolisation procedure like "anchor technique," "scaffold technique" and "balloon assisted technique." Cerebral arteriovenous malformations (CAVM) are present in 10-20% of patients with HHT and multiple in 50% of cases. Cortical surface is the most frequent localisation. Angiography is needed to diagnose all CAVM and to clarify the angioarchitecture of the lesion. In HHT CAVM are usually either micro-AVM, with a nidus not bigger than 1 cm, or small AVM, with a nidus between 1 and 3 cm. Quite frequently there are lesions characterised by arteriovenous fistulas. In the three patterns of CAVM usually found in HHT, small AVM are the most risky for bleeding although the risk is lower than that associated with sporadic ones. It is estimated from 0.38 to 0.69% per year in spite of the general incidence of bleeding in sporadic CAVM that ranges from 2 to 4% per year. In HHT patients, at present, the precise indications and timing of treatment are not established. Trend is to treat small AVM and AVF and to follow-up micro-AVM with MRI and angiography. As for sporadic CAVM, treatment of small AVM is usually referred to stereotactic radiosurgery. Endovascular embolisation is proposable if the lesion is easily reachable by microcatheterism and the position of the microcatheter is safe. Glue is used for embolisation and the technique is briefly discussed.


Assuntos
Malformações Arteriovenosas/terapia , Malformações Arteriovenosas Intracranianas/terapia , Circulação Pulmonar/fisiologia , Telangiectasia Hemorrágica Hereditária/complicações , Angiografia , Malformações Arteriovenosas/etiologia , Humanos , Malformações Arteriovenosas Intracranianas/etiologia
20.
J Cardiovasc Surg (Torino) ; 46(2): 149-53, 2005 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-15793494

RESUMO

Aim of the study was to validate the use of endoluminal stent-graft treatment as an alternative to conventional surgery in patients affected by blunt chest trauma and aortic disruption with multiple associated lesions. We report the case of a young female admitted with diagnosis of descending thoracic aortic transection and multiple traumas following a car accident. Spiral computed tomography revealed circular disruption of thoracic aorta immediately after isthmus region with intussusception of leaflets and pseudo-coartation. Doppler analysis showed a 70 mmHg transaortic gradient. The hemodynamic evaluation confirmed the existence of severe transaortic gradient. A Gore-TAG endoprosthesis (26 x 100 mm) was selected. Intraoper-ative transesophageal echocardiography assessment was performed to monitoring the entire procedure. The final arteriogram showed an optimal sealing at proximal and distal site without endoleak with complete readjustment of intimal leaflets to the aortic wall and disappearance of transaortic gradient related to the pseudo-coartation. No complication was observed in the early postoperative and patient was discharged one month later once complete rehabilitation of associated lesion was obtained. Computed tomography scan performed before discharge revealed persistency of patent lumen of aorta with fibrosis of readjusted circumferential intimal flap. In conclusion endovascular repair of complete aortic transection may result safe and effective particularly in patients with extensive associated injuries. Indeed the severity of coexisting non-aortic lesions could be adversely affected by conventional surgery in consideration of high surgical morbidity due to open thoracotomy. Stent-graft repair allows the patient to timely undergo medical or surgical management of associated lesions and a prompt rehabilitation with shorter hospital stay.


Assuntos
Aneurisma da Aorta Torácica/cirurgia , Ruptura Aórtica/cirurgia , Implante de Prótese Vascular/métodos , Intussuscepção/cirurgia , Pneumoperitônio/cirurgia , Pneumotórax/cirurgia , Stents , Acidentes de Trânsito , Doença Aguda , Adulto , Aorta Torácica/diagnóstico por imagem , Aorta Torácica/lesões , Aneurisma da Aorta Torácica/diagnóstico , Aneurisma da Aorta Torácica/etiologia , Ruptura Aórtica/diagnóstico , Ruptura Aórtica/etiologia , Ecocardiografia Doppler , Ecocardiografia Transesofagiana , Feminino , Humanos , Intussuscepção/diagnóstico , Intussuscepção/etiologia , Fígado/diagnóstico por imagem , Fígado/lesões , Traumatismo Múltiplo/complicações , Pneumoperitônio/diagnóstico , Pneumoperitônio/etiologia , Pneumotórax/diagnóstico , Pneumotórax/etiologia , Fraturas das Costelas/diagnóstico , Fraturas das Costelas/etiologia , Fraturas das Costelas/cirurgia , Tomografia Computadorizada Espiral
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...