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1.
Nano Lett ; 19(9): 5915-5919, 2019 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-31373825

RESUMO

Diamond has two crystallographically inequivalent sites in the unit cell. In doped diamond, dopant occupation in the two sites is expected to be equal. Nevertheless, preferential dopant occupation during growth under nonequilibrium conditions is of fundamental importance, for example, to enhance the properties of nitrogen-vacancy (N-V) centers; therefore, this is a promising candidate for a qubit. However, the lack of suitable experimental techniques has made it difficult to study the crystal- and chemical-site-resolved local structures of dopants. Here, we confirm the identity of two chemical sites with asymmetric dopant incorporation in the diamond structure, via the photoelectron holography (PEH) of heavily phosphorus (P)-doped diamond prepared by chemical vapor deposition. One is substitutionally incorporated P with preferential site occupations and the other can be attributed to a PV split vacancy complex with preferential orientation. The present study shows that PEH is a valuable technique to study the local structures around dopants with a resolution of crystallographically inequivalent but energetically equivalent sites/orientations. Such information provides strategies to improve the properties of dopant related-complexes in which alignment is crucial for sensing of magnetic field or quantum spin register using N-V centers in diamond.

2.
Nat Mater ; 16(11): 1090-1095, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-28967918

RESUMO

Weyl fermions have been observed as three-dimensional, gapless topological excitations in weakly correlated, inversion-symmetry-breaking semimetals. However, their realization in spontaneously time-reversal-symmetry-breaking phases of strongly correlated materials has so far remained hypothetical. Here, we report experimental evidence for magnetic Weyl fermions in Mn3Sn, a non-collinear antiferromagnet that exhibits a large anomalous Hall effect, even at room temperature. Detailed comparison between angle-resolved photoemission spectroscopy (ARPES) measurements and density functional theory (DFT) calculations reveals significant bandwidth renormalization and damping effects due to the strong correlation among Mn 3d electrons. Magnetotransport measurements provide strong evidence for the chiral anomaly of Weyl fermions-namely, the emergence of positive magnetoconductance only in the presence of parallel electric and magnetic fields. Since weak magnetic fields (approximately 10 mT) are adequate to control the distribution of Weyl points and the large fictitious fields (equivalent to approximately a few hundred T) produced by them in momentum space, our discovery lays the foundation for a new field of science and technology involving the magnetic Weyl excitations of strongly correlated electron systems such as Mn3Sn.

3.
Phys Rev Lett ; 120(8): 086402, 2018 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-29543003

RESUMO

Experimental determinations of bulk band topology in the solid states have been so far restricted to only indirect investigation through the probing of surface states predicted by electronic structure calculations. We here present an alternative approach to determine the band topology by means of bulk-sensitive soft x-ray angle-resolved photoemission spectroscopy. We investigate the bulk electronic structures of the series materials, Ce monopnictides (CeP, CeAs, CeSb, and CeBi). By performing a paradigmatic study of the band structures as a function of their spin-orbit coupling, we draw the topological phase diagram and unambiguously reveal the topological phase transition from a trivial to a nontrivial regime in going from CeP to CeBi induced by the band inversion. The underlying mechanism of the phase transition is elucidated in terms of spin-orbit coupling in concert with their semimetallic band structures. Our comprehensive observations provide a new insight into the band topology hidden in the bulk states.

4.
Int Endod J ; 50 Suppl 2: e19-e30, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28169432

RESUMO

AIMS: To investigate the cytotoxicity and bioactivity of several pulpotomy materials: Biodentine (Septodont, Saint-Maur-des-Fosses, France) MTA (Angelus, Londrina, PR, Brazil), Theracal LC (Bisco Inc., Schamburg, IL, USA) and IRM (Dentsply DeTrey GmbH, Konstanz, Germany), after contact with stem cells isolated from human exfoliated primary teeth (SHEDs). METHODOLOGY: SHEDs were cultured in the presence of the eluates of various pulpotomy materials for 24, 48 and 72 h. Cell viability was determined by mitochondrial dehydrogenase enzymatic (MTT) assay. Apoptosis and changes in cell phenotype were evaluated by flow cytometry. Also, an in vitro scratch wound-healing assay was used to determine their effects on cell migration. To assess cell morphology and attachment to the different pulpotomy materials, SHEDs were directly seeded onto the material surfaces and analysed by scanning electron microscopy (SEM). Finally, the deposition of a calcified matrix in presence of these materials was verified by Alizarin Red staining. Statistical analysis was performed with analysis of variance and Bonferroni or Tukey post-test (α = 0.05). RESULTS: Cell viability in the presence of Biodentine eluates was significantly higher to that obtained using complete medium alone (control; P < 0.01) and was also significantly higher than using MTA Angelus from 48 h of incubation (P < 0.01). However, Theracal LC and IRM were associated with low rates of cell viability (P < 0.001). Similar results were obtained in an apoptosis assay. In addition, SHEDs maintained their mesenchymal phenotype in all conditions although their capacity to migrate was higher in the presence of Biodentine. SEM studies revealed a suitable proliferation rate, cell spreading and attachment, especially when using Biodentine and MTA Angelus discs. Finally, Biodentine eluates significantly induced calcified matrix deposition from 7 days of culture (P < 0.01). CONCLUSIONS: Biodentine exhibited better cytocompatibility and bioactivity than MTA Angelus, Theracal LC and IRM.


Assuntos
Agentes de Capeamento da Polpa Dentária e Pulpectomia/farmacologia , Pulpotomia , Células-Tronco/efeitos dos fármacos , Dente Decíduo , Compostos de Alumínio/farmacologia , Compostos de Alumínio/toxicidade , Apoptose/efeitos dos fármacos , Compostos de Cálcio/farmacologia , Compostos de Cálcio/toxicidade , Movimento Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Combinação de Medicamentos , Citometria de Fluxo , Humanos , Técnicas In Vitro , Teste de Materiais , Metilmetacrilatos/farmacologia , Metilmetacrilatos/toxicidade , Microscopia Eletrônica de Varredura , Óxidos/farmacologia , Óxidos/toxicidade , Fenótipo , Agentes de Capeamento da Polpa Dentária e Pulpectomia/toxicidade , Silicatos/farmacologia , Silicatos/toxicidade , Fatores de Tempo , Cimento de Óxido de Zinco e Eugenol/farmacologia , Cimento de Óxido de Zinco e Eugenol/toxicidade
5.
J Clin Pharm Ther ; 40(5): 573-577, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26249257

RESUMO

WHAT IS KNOWN AND OBJECTIVE: Endoscopic submucosal dissection of early colorectal neoplasms (ESD-ECN) is known to be an operation with risk of contamination, possibly requiring pre-operative antimicrobial prophylaxis for the prevention of post-operative infection. However, an evaluation of the need for pre-operative antimicrobial prophylaxis for ESD-ECN has yet to be reported. The objective of this study was to determine whether pre-operative antimicrobial prophylaxis is associated with a reduced incidence of post-operative infection following ESD-ECN. METHODS: The present retrospective case-controlled study utilized a database built from the medical records of 14 university hospitals throughout Japan. Patients who were admitted and discharged from the hospital from April 2012 to October 2013 and who had undergone ESD-ECN were included in the study. Patients who had been undergone any other operation during their course of hospitalization, and patients who were prescribed antimicrobial agents for reasons other than post-operative infection or for prophylaxis were excluded. Characteristics of the study population, pre-operative antimicrobial prophylaxis and antimicrobial therapy for post-operative infection were investigated. In addition, we compared the characteristics of patients with post-operative infection (PI) and those with no post-operative infection (NPI). Univariate analyses were used to estimate the odds ratios (OR) and 95% confidence intervals (95% CI). RESULTS AND DISCUSSION: We obtained the records of 522 patients who had undergone ESD-ECN from the database. After application of exclusion criteria, 421 patients were enrolled. The post-operative infection rate was 1·2%. Peritonitis was found most to be the most common post-operative infection (44%). Pre-operative antimicrobial prophylaxis was used for 314 patients (75%), with a median duration of 3·0 (range 1-11) days. Cefotiam was most frequently prescribed for pre-operative antimicrobial prophylaxis (56%). Antimicrobial therapies were started 1-10 days after ESD-ECN for a duration of 1-14 days. Pre-operative antimicrobial prophylaxis was not associated with post-operative infection rate, with an OR (95% CI) of 0·73 (0·08-6·61). However, digestive tract perforation was shown to be associated with post-operative infection and had an OR (95% CI) of 17·1 (1·66-176·45). WHAT IS NEW AND CONCLUSION: Post-operative infection is an exceedingly rare event following ESD-ECN. Pre-operative antimicrobial prophylaxis had no significant effect on post-operative infection following ESD-ECN and thus may be unnecessary. Instead, prevention of digestive tract perforation may be more critical for the decrease in post-operative infections.

6.
Nature ; 438(7068): 647-50, 2005 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-16319887

RESUMO

The physical properties of lightly doped semiconductors are well described by electronic band-structure calculations and impurity energy levels. Such properties form the basis of present-day semiconductor technology. If the doping concentration n exceeds a critical value n(c), the system passes through an insulator-to-metal transition and exhibits metallic behaviour; this is widely accepted to occur as a consequence of the impurity levels merging to form energy bands. However, the electronic structure of semiconductors doped beyond n(c) have not been explored in detail. Therefore, the recent observation of superconductivity emerging near the insulator-to-metal transition in heavily boron-doped diamond has stimulated a discussion on the fundamental origin of the metallic states responsible for the superconductivity. Two approaches have been adopted for describing this metallic state: the introduction of charge carriers into either the impurity bands or the intrinsic diamond bands. Here we show experimentally that the doping-dependent occupied electronic structures are consistent with the diamond bands, indicating that holes in the diamond bands play an essential part in determining the metallic nature of the heavily boron-doped diamond superconductor. This supports the diamond band approach and related predictions, including the possibility of achieving dopant-induced superconductivity in silicon and germanium. It should also provide a foundation for the possible development of diamond-based devices.

7.
J Clin Pharm Ther ; 36(2): 230-6, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21366653

RESUMO

WHAT IS KNOWN AND OBJECTIVE: Meropenem is frequently employed as an empirical treatment for serious infections, but there has been no report on its population pharmacokinetic parameters for Japanese patients. Our aim is to undertake a population pharmacokinetic analysis of meropenem using non-linear mixed effects model (NONMEM). METHODS: Data from 68 patients were analysed via NONMEM with the first-order method. The participants' covariates, including gender, age, actual body weight, serum creatinine, serum albumin, serum total protein and creatinine clearance, were analyzed by the forward inclusion and backward elimination method to identify their potential influence on meropenem pharmacokinetics. The adequacy of the constructed model was assessed by goodness-of-fit plots and the precision of the parameter estimated at each step of the model development. To assess the robustness of the estimated parameter, bootstrap analysis was performed. RESULTS AND DISCUSSION: The data were best described by a one-compartment model. The serum creatinine values modified by the below normal limit in our hospital (mSCR) were an influential covariate for clearance (CL): CL (L/h) = 11·1 × (mSCR/0·7)(-1). The volume of distribution was estimated as 33·6 L. The coefficient of variation of the inter-individual variability of CL and the residual variability were 52·1% and 0·827% µg/mL, respectively. A comparison of the population pharmacokinetic parameters of meropenem in the final model estimated in NONMEM with original data, and 1000 bootstrap samples shows that both sets of estimates were comparable, thereby indicating the robustness of the proposed model. WHAT IS NEW AND CONCLUSION: A population pharmacokinetic model that satisfactorily described the disposition and variability of meropenem in our Japanese population is described. NONMEM analysis showed that the clearance of meropenem depended on modified serum creatinine. The results of this study should help Japanese patients on meropenem by improving the prediction accuracy of dosing using the Bayesian method.


Assuntos
Antibacterianos/farmacocinética , Tienamicinas/farmacocinética , Adulto , Idoso , Idoso de 80 Anos ou mais , Antibacterianos/sangue , Teorema de Bayes , Feminino , Humanos , Japão , Masculino , Meropeném , Pessoa de Meia-Idade , Modelos Biológicos , Projetos de Pesquisa , Tienamicinas/sangue
8.
Rev Sci Instrum ; 78(6): 066107, 2007 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-17614651

RESUMO

Spectroscopic photoemission and low energy electron microscope (SPELEEM) improved its performance after installation at BL17SU/SPring-8, where a multipolarization-mode undulator is employed to produce circularly and linearly polarized soft x rays. This undulator enables us to study the domain structures of ferromagnetic and antiferromagnetic materials by x-ray magnetic circular dichroism and x-ray magnetic linear dichroism. SPELEEM is used to study light elements (C, N, and O), 3d transition-metal elements and 4f rare earth elements, utilizing a wide range of photon energies. The two cylindrical mirrors adopted in front of SPELEEM ensure an illumination area of 14 x 14 microm(2) on the samples. The lateral resolution of a secondary electron photoemission electron microscope image is estimated to be better than 85 nm, whereas the energy resolution of the instrument is better than 0.4 eV.


Assuntos
Microscopia Eletrônica/instrumentação , Refratometria/instrumentação , Espectrometria por Raios X/instrumentação , Desenho de Equipamento , Análise de Falha de Equipamento , Microscopia Eletrônica/métodos , Refratometria/métodos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Espectrometria por Raios X/métodos
9.
Biochim Biophys Acta ; 1337(1): 40-6, 1997 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-9003435

RESUMO

A newly isolated actinomycete belonging to Saccharothrix sp. was found to produce a unique enzyme catalyzing D-amino acid transfer. The enzyme, which was tentatively named D-amino acid transferase, was purified 2600-fold to electrophoretic homogeneity and the molecular mass was 41 kDa. The enzyme was D-configuration specific and recognized aromatic D-amino acid esters to form oligo D-amino acid esters. D-Phenylalanine ester was favored as substrate over other D-amino acid esters. The optimum conditions for oligo D-phenylalanine ester formation by D-amino acid transferase were pH 7.0 and 40 degrees C. The enzyme was inhibited by DAN, EPNP and DFP.


Assuntos
Actinomycetales/enzimologia , Aciltransferases/metabolismo , Aminoaciltransferases , Proteínas de Bactérias , Aciltransferases/antagonistas & inibidores , Aciltransferases/isolamento & purificação , Inibidores Enzimáticos/farmacologia , Isomerismo , Fenilalanina/análogos & derivados , Fenilalanina/metabolismo , Especificidade por Substrato
10.
J Am Coll Cardiol ; 38(7): 1879-84, 2001 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11738288

RESUMO

OBJECTIVES: The purpose of this study was twofold: 1) to examine the relationship between menstrual cycle and coronary flow velocity reserve (CFVR) in young healthy women, and 2) to evaluate the effect of hormone replacement therapy by estrogen on CFVR in postmenopausal women, using transthoracic color Doppler echocardiography (TTCDE). BACKGROUND: Although the incidence of cardiovascular disease is lower in women before menopause compared with men, postmenopausal women have an incidence of coronary artery disease similar to that of men of the same age. This is mainly dependent upon estrogen deficiency. However, no clinical report has yet examined the effect of estrogen on CFVR, which is one index of coronary microcirculation. METHODS: We examined 15 male and both 15 premenopausal and 10 postmenopausal female healthy volunteers. We measured coronary flow velocity of the left anterior descending coronary artery at baseline and hyperemic conditions during adenosine triphosphate infusion by TTCDE and determined CFVR. Each premenopausal woman was studied two times (menstrual [M] and follicular [F] phases) in one menstrual cycle. Fifteen men were also studied at a time corresponding to women's menstrual cycle. The postmenopausal women were studied before and two hours after oral administration of conjugated estrogen (CE). RESULTS: Serum 17beta-estradiol level in premenopausal women increased in the F phase and decreased to the same levels as in men, as in the M phase and as in postmenopausal women (123 +/- 9 pg/ml vs. 28 +/- 6 pg/ml, 25 +/- 9 pg/ml and 19 +/- 11 pg/ml; p < 0.0001, respectively). The CFVR increased in the F phase compared with that in the M phase (4.8 +/- 0.4 vs. 3.7 +/- 0.8, p < 0.0001). We found that CFVR in men remained unchanged (3.7 +/- 0.6 vs. 3.8 +/- 0.5). After CE administration, CFVR increased compared with baseline in postmenopausal women (4.1 +/- 0.8 vs. 3.4 +/- 0.8, p < 0.005). CONCLUSIONS: In premenopausal women, CFVR determined by TTCDE varied during the menstrual cycle, and in postmenopausal women, CFVR increased after acute estrogen replacement.


Assuntos
Velocidade do Fluxo Sanguíneo/fisiologia , Circulação Coronária/fisiologia , Ecocardiografia Doppler em Cores , Terapia de Reposição de Estrogênios , Ciclo Menstrual/fisiologia , Adulto , Idoso , Velocidade do Fluxo Sanguíneo/efeitos dos fármacos , Circulação Coronária/efeitos dos fármacos , Ecocardiografia Doppler em Cores/efeitos dos fármacos , Feminino , Humanos , Masculino , Ciclo Menstrual/efeitos dos fármacos , Pessoa de Meia-Idade , Valores de Referência , Fatores Sexuais
11.
J Am Coll Cardiol ; 37(5): 1310-5, 2001 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11300440

RESUMO

OBJECTIVES: We evaluated the value of coronary flow reserve (CFR), as determined by transthoracic Doppler echocardiography (TTDE), for physiologic assessment of coronary artery stenosis severity, and we compared TTDE measurements with those obtained by exercise thallium-201 (Tl-201) single-photon emission computed tomography (SPECT). BACKGROUND: Coronary flow reserve measurements by TTDE have been reported to be useful for assessing angiographic left anterior descending coronary artery (LAD) stenosis. However, discrepancies exist between angiographic and physiologic estimates of coronary lesion severity. METHODS: We studied 36 patients suspected of having coronary artery disease. The flow velocity in the distal LAD was measured by TTDE both at rest and during intravenous infusion of adenosine. Coronary flow reserve was calculated as the ratio of hyperemic to basal peak (peak CFR) and mean (mean CFR) diastolic flow velocities. The CFR measurements by TTDE were compared with the results of Tl-201-SPECT. RESULTS: Complete TTDE data were acquired for 33 of 36 study patients. Of these 33 patients, Tl-201-SPECT confirmed reversible perfusion defects in the LAD territories in 12 patients (group A). Twenty-one patients had normal perfusion in the LAD territories (group B). Peak CFR and mean CFR (mean value +/- SD) were 1.5 +/- 0.6 and 1.5 +/- 0.7 in group A and 2.8 +/- 0.8 and 2.7 +/- 0.7 in group B, respectively. Both peak and mean CFR < or = 2.0 predicted reversible perfusion defects, with a sensitivity and specificity of 92% and 90%, respectively. CONCLUSIONS: Noninvasive measurement of CFR by TTDE provides data equivalent to those obtained by Tl-201-SPECT for physiologic estimation of the severity of LAD stenosis.


Assuntos
Circulação Coronária/fisiologia , Doença das Coronárias/fisiopatologia , Ecocardiografia Doppler , Tomografia Computadorizada de Emissão de Fóton Único , Idoso , Velocidade do Fluxo Sanguíneo/fisiologia , Meios de Contraste , Angiografia Coronária , Doença das Coronárias/diagnóstico , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Polissacarídeos , Sensibilidade e Especificidade , Radioisótopos de Tálio
12.
Phys Rev Lett ; 85(2): 381-4, 2000 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-10991288

RESUMO

Intercalation of neutral ammonia molecules into trivalent face-centered-cubic (fcc) fulleride superconductors induces a dramatic change in electronic states. Monoammoniated alkali fulleride salts (NH3)K3-xRbxC60, forming an isostructural orthorhombic series, undergo an antiferromagnetic transition, which was found by the electron spin resonance experiment. The Neel temperature first increases with the interfullerene spacing and then decreases for (NH3)Rb3C60, forming a maximum at 76 K. This feature is explained by the generalized phase diagram of Mott-Hubbard transition with an antiferromagnetic ground state.

13.
J Biochem ; 99(6): 1625-30, 1986 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-3528136

RESUMO

The protease from Streptomyces cellulosae preferentially catalyzed the formation of (L-Leu-Gly)2 (P1) and (L-Leu-Gly)3 (P2) in highly concentrated solutions of L-Leu-Gly, although it weakly hydrolyzed the substrate at the same time. The formation of P1, P2, L-Leu, and Gly was studied at various pH values, temperatures, and substrate concentrations. The initial velocities (v1, v2, and vH) of formation of P1, P2, and L-Leu (or Gly) and the sum (v1T) of v1 and v2 were determined. The effects of pH and temperature on v1, v2, vH, and v1T were examined at a fixed substrate concentration. The optimum pH and optimum temperature for each of the processes forming P1, P2, L-Leu, and Gly were 8.0 and 65 degrees C, respectively. In the study on the effect of substrate concentration, the plots of the initial velocities versus substrate concentrations were sigmoidal at lower substrate concentrations. The dependence of v1T on the substrate concentration could be explained by a mechanism involving a single active center forming the peptide bonds and two substrate-binding sites located on the left sites (S1 and S2) and the right sites (S1' and S2') of the active center of this enzyme.


Assuntos
Dipeptídeos/metabolismo , Peptídeo Hidrolases/metabolismo , Streptomyces/enzimologia , Catálise , Concentração de Íons de Hidrogênio , Cinética , Matemática , Modelos Químicos , Temperatura
14.
Ann N Y Acad Sci ; 417: 270-6, 1983.
Artigo em Inglês | MEDLINE | ID: mdl-6200035

RESUMO

This study reports the use of radiolabeled antibody to AFP and CEA for the detection and localization of AFP- or CEA-producing tumors. Thirty-one patients received 131I-labeled anti-AFP or anti-CEA antibodies. Photoscans were taken at 24 and 48 hours after injection of radioantibodies. In three of six patients with CEA-producing tumors, radioimmunodetection with anti-CEA antibody showed positive scans. In AFP-producing tumors, 7 of 15 patients had positive findings on immunoscintigraphy using polyclonal anti-AFP antibody, and two of nine patients had positive findings when monoclonal antibodies were used. Analysis of radioantibody in the blood after injection showed both complex and free antibody with immunoreactivity in the circulation, and smaller complexes were seen to form after administration of monoclonal antibodies.


Assuntos
Antígeno Carcinoembrionário/análise , Neoplasias/diagnóstico , alfa-Fetoproteínas/análise , Abdome/diagnóstico por imagem , Complexo Antígeno-Anticorpo/análise , Antígeno Carcinoembrionário/imunologia , Humanos , Fígado/diagnóstico por imagem , Masculino , Radioimunoensaio/métodos , Cintilografia , alfa-Fetoproteínas/imunologia
15.
J Am Soc Echocardiogr ; 12(4): 225-30, 1999 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10196498

RESUMO

Intracardiac echocardiography (ICE) is a developing technology and a promising method for visualizing intracardiac structures. However, its applications are currently limited to guidance during mitral valvuloplasty, catheter ablation, or electrophysiologic examination. The goal of this study was to observe the aortic valve, measure the annular diameter of the valve by ICE through a right-sided approach, and compare the results by ICE with those by transthoracic echocardiography (TTE) or transesophageal echocardiography (TEE). We studied 18 patients (9 men, 9 women, aged 19 to 72 years) with various heart diseases, including 15 patients with mitral or aortic valvular disease. An imaging catheter was advanced through a long sheath into the outflow tract of the right ventricle. We obtained good longitudinal views of the aortic valve in all patients. Two of the 18 patients had poor image quality by TTE. The annular diameter by ICE correlated more closely with TEE than with TTE. In conclusion, right-sided ICE is a safe, simple, and useful procedure for observing the aortic valve during cardiac catheterization without additional discomfort in the patients. Right-sided ICE is superior to TTE in observing the aortic valve and measuring the annular diameter of the valve. The annular diameter can be measured by ICE as precisely as by TEE.


Assuntos
Valva Aórtica/diagnóstico por imagem , Ecocardiografia/métodos , Ultrassonografia de Intervenção , Adulto , Idoso , Prolapso da Valva Aórtica/diagnóstico por imagem , Calcinose/diagnóstico por imagem , Cateterismo Cardíaco/instrumentação , Cateterismo Cardíaco/métodos , Ecocardiografia/instrumentação , Ecocardiografia Transesofagiana , Feminino , Cardiopatias/diagnóstico por imagem , Doenças das Valvas Cardíacas/diagnóstico por imagem , Ventrículos do Coração/diagnóstico por imagem , Humanos , Aumento da Imagem , Masculino , Pessoa de Meia-Idade , Valva Mitral/diagnóstico por imagem , Método Simples-Cego , Ultrassonografia de Intervenção/instrumentação , Ultrassonografia de Intervenção/métodos , Gravação de Videoteipe
16.
J Am Soc Echocardiogr ; 12(4): 241-51, 1999 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10196501

RESUMO

Intraoperative color Doppler transesophageal echocardiography with a 4- to 7-MHz transducer was performed on 28 consecutive patients who underwent coronary artery bypass grafting to image and evaluate the transmural coronary blood flow before and after cardiopulmonary bypass. The transmural coronary flow was visualized in 26 (92.8%) of 28 patients in the inferior wall and in 13 (46.4%) of 28 patients in the lateral wall. The peak diastolic flow velocity of the transmural coronary artery in the inferior and lateral wall was significantly increased after coronary revascularization in patients with a successful bypass graft to the right coronary artery (from 34.0 +/- 19.7 to 64.9 +/- 30.9 cm/s, P <.001, n = 10) and to the left circumflex coronary artery (from 35.1 +/- 18.6 to 62.1 +/- 21.1 cm/s, P <.001, n = 10). No significant changes were observed in patients with no bypass graft to the right or left circumflex coronary artery. Coronary blood flow can be mapped and the velocity measured with Doppler transesophageal echocardiography with a high-frequency (4- to 7-MHz) transducer. Assessment of the transmural coronary flow may provide valuable information and aid in decision making during surgical revascularization.


Assuntos
Ponte de Artéria Coronária , Circulação Coronária/fisiologia , Ecocardiografia Doppler em Cores , Ecocardiografia Transesofagiana , Cuidados Intraoperatórios , Ultrassonografia de Intervenção , Adulto , Idoso , Angina Instável/cirurgia , Velocidade do Fluxo Sanguíneo , Ponte Cardiopulmonar , Doença das Coronárias/cirurgia , Vasos Coronários/diagnóstico por imagem , Tomada de Decisões , Diástole , Ecocardiografia Doppler em Cores/instrumentação , Ecocardiografia Transesofagiana/instrumentação , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Planejamento de Assistência ao Paciente , Transdutores , Ultrassonografia de Intervenção/instrumentação
17.
J Am Soc Echocardiogr ; 14(4): 275-84, 2001 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11287890

RESUMO

Quantitative assessment of left ventricular ejection fraction is an essential component of cardiac evaluation. We performed real-time 3-dimensional echocardiography in 56 consecutive patients who underwent multigated radionuclide angiography. Thirteen patients were excluded for the following reasons: 5 for large size of left ventricle required for image acquisition, 5 for suboptimal image quality in real-time 3-dimensional echocardiography, and 3 for atrial fibrillation. Finally, we compared left ventricular ejection fraction assessed by real-time 3-dimensional echocardiography and conventional 2-dimensional echocardiography with that obtained by multigated radionuclide angiography in 43 patients. Left ventricular ejection fraction was determined by real-time 3-dimensional echocardiography with the use of parallel plane-disks and sector plane-disks summation methods. A good correlation was obtained between both real-time 3-dimensional echocardiography methods and multigated radionuclide angiography (r = 0.87 and 0.90, standard error of estimate = 3.7% and 4.2%), whereas the relation between the 2-dimensional echocardiography method and radionuclide angiography demonstrated a significant departure from the line of identity (P <.001). In addition, interobserver variability was significantly lower (P <.05) for the real-time 3-dimensional echocardiography methods than that by the 2-dimensional echocardiography method. Real-time 3-dimensional echocardiography may be used for quantification of left ventricular function as an alternative to conventional methods in patients with adequate image quality.


Assuntos
Ecocardiografia Tridimensional , Disfunção Ventricular Esquerda/diagnóstico por imagem , Adulto , Idoso , Angiografia Coronária , Ecocardiografia , Feminino , Humanos , Modelos Lineares , Masculino , Pessoa de Meia-Idade , Variações Dependentes do Observador , Imagens de Fantasmas , Angiografia Cintilográfica
18.
Oncol Rep ; 3(1): 87-9, 1996 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21594320

RESUMO

To elucidate the difference in the liver carcinogenetic process during hepatitis B virus (HBV) and hepatitis C virus (HCV) infections, non-tumorous liver tissues obtained from 10 patients who developed HBV-associated hepatocellular carcinoma (HCC) without cirrhosis were compared with those obtained from 26 patients who developed HCV-associated HCC without cirrhosis. The extent of fibrosis was similar in both groups. In contrast, necroinflammatory activities were significantly higher in patients with HCV than in patients with HBV. These results indicate that ongoing liver inflammation mediates the hepatocarcinogenesis more pronouncedly in HCV infection than in HBV infection.

19.
Eur J Radiol ; 15(3): 205-10, 1992 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-1490446

RESUMO

To establish the time-course of bone scans after bipolar hip arthroplasty (BHA) bone scanning was performed before and after surgery in 22 hips. The influence of migration of the outer head into the acetabulum on the time-course of bone scans was examined by analyzing the relationship between the uptake of radioisotope and the magnitude of migration. The bone scans were quantitatively analyzed by single photon emission computed tomography (SPECT) on the basis of the ratio of radioactivity at the acetabulum to that in the anterior superior iliac spine (ASIS). The increased radionuclide activity decreased exponentially to a baseline with time after surgery. The postoperative uptake ratio could be expressed as a function of the preoperative uptake ratio and the postoperative length of time. The regression slope representing the decreasing rate of uptake showed no significant differences between two groups divided by the magnitude of migration of the outer head. Migration of the outer head was considered not to influence the time-course of the bone scans.


Assuntos
Prótese de Quadril , Osteoartrite do Quadril/diagnóstico por imagem , Tomografia Computadorizada de Emissão de Fóton Único , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Avaliação como Assunto , Feminino , Migração de Corpo Estranho/diagnóstico por imagem , Prótese de Quadril/efeitos adversos , Humanos , Masculino , Pessoa de Meia-Idade , Osteoartrite do Quadril/cirurgia , Medronato de Tecnécio Tc 99m
20.
Spine (Phila Pa 1976) ; 17(11): 1309-15, 1992 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-1462206

RESUMO

Pain provocation was analyzed in 1477 intervertebral discs in 523 patients subjected to lumbar computed tomography/discography. The relation between pain provocation and the degree of general degeneration and anular disruption assessed according to the Dallas Discogram Description as indices of intradiscal deterioration was investigated. Pain provocation was also evaluated after categorizing the discs by the clinical diagnosis. Pain provocation showed little relation to intradiscal deterioration, whereas a strong relation was found between it and herniated nucleus pulposus. in herniated nucleus pulposus, discs with extraligamentous extrusion or sequestration, large protrusions, maximum protrusion site at the nerve root portion, and herniation routes passing through the central portion of the disc showed a high pain provocation ratio. Pain provocation ratios of discs associated with spinal canal stenosis were extremely low.


Assuntos
Deslocamento do Disco Intervertebral/diagnóstico por imagem , Deslocamento do Disco Intervertebral/fisiopatologia , Disco Intervertebral/diagnóstico por imagem , Vértebras Lombares/diagnóstico por imagem , Medição da Dor , Tomografia Computadorizada por Raios X/métodos , Adolescente , Adulto , Idoso , Feminino , Humanos , Disco Intervertebral/patologia , Deslocamento do Disco Intervertebral/patologia , Vértebras Lombares/patologia , Masculino , Pessoa de Meia-Idade
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