Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 112
Filtrar
1.
Clin Genet ; 83(2): 135-44, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22548404

RESUMO

Oral-facial-digital syndrome type 1 (OFD1; OMIM #311200) is an X-linked dominant disorder, caused by heterozygous mutations in the OFD1 gene and characterized by facial anomalies, abnormalities in oral tissues, digits, brain, and kidney; and male lethality in the first or second trimester pregnancy. We encountered a family with three affected male neonates having an 'unclassified' X-linked lethal congenital malformation syndrome. Exome sequencing of entire transcripts of the whole X chromosome has identified a novel splicing mutation (c.2388+1G > C) in intron 17 of OFD1, resulting in a premature stop codon at amino acid position 796. The affected males manifested severe multisystem complications in addition to the cardinal features of OFD1 and the carrier female showed only subtle features of OFD1. The present patients and the previously reported male patients from four families (clinical OFD1; Simpson-Golabi-Behmel syndrome, type 2 with an OFD1 mutation; Joubert syndrome-10 with OFD1 mutations) would belong to a single syndrome spectrum caused by truncating OFD1 mutations, presenting with craniofacial features (macrocephaly, depressed or broad nasal bridge, and lip abnormalities), postaxial polydactyly, respiratory insufficiency with recurrent respiratory tract infections in survivors, severe mental or developmental retardation, and brain malformations (hypoplasia or agenesis of corpus callosum and/or cerebellar vermis and posterior fossa abnormalities).


Assuntos
Exoma , Doenças Genéticas Ligadas ao Cromossomo X/patologia , Mutação , Síndromes Orofaciodigitais/patologia , Proteínas/genética , Feminino , Aconselhamento Genético , Doenças Genéticas Ligadas ao Cromossomo X/genética , Humanos , Masculino , Síndromes Orofaciodigitais/genética , Linhagem , Gravidez , Splicing de RNA , Análise de Sequência de DNA
2.
J Phys Condens Matter ; 24(7): 075602, 2012 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-22301486

RESUMO

Soft resonant x-ray Bragg diffraction (SRXD) at the Ho M4,5 edges has been used to study Ho 4f multipoles in the combined magnetic and orbitally ordered phase of HoB2C2. A full description of the energy dependence for both σ and π incident x-rays at two different azimuthal angles, as well as the ratio I(σ)/I(π) as a function of azimuthal angle for a selection of energies, allows a determination of the higher order multipole moments of rank 1 (dipole) to 6 (hexacontatetrapole). The Ho 4f multipole moments have been estimated, indicating a dominant hexadecapole (rank 4) order with an almost negligible influence from either the dipole or the octupole magnetic terms. The analysis incorporates both the intra-atomic magnetic and quadrupolar interactions between the 3d core and 4f valence shells as well as the interference of contributions to the scattering that behave differently under time reversal. Comparison of SRXD, neutron diffraction and non-resonant x-ray diffraction shows that the magnetic and quadrupolar order parameters are distinct. The (00½) component of the magnetic order exhibits a Brillouin type increase below the orbital ordering temperature T(Q), while the quadrupolar order increases more sharply. We conclude that the quadrupolar interaction is strong, but quadrupolar order only occurs when the magnetic order gives rise to a quasi-doublet ground state, which results in a lock-in of the orbitals at T(Q).

3.
Br J Radiol ; 85(1016): e378-82, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22253355

RESUMO

OBJECTIVE: To evaluate the effect of adaptive iterative dose reduction (AIDR) on image noise and image quality as compared with standard filtered back projection (FBP) in 320-detector row CT coronary angiography (CTCA). METHODS: 50 patients (14 females, mean age 68 ± 9 years) who underwent CTCA (100 kV or 120 kV, 400-580 mA) within a single heartbeat were enrolled. Studies were reconstructed with FBP and subsequently AIDR. Image noise, vessel contrast and contrast-to-noise ratio (CNR) in the coronary arteries were evaluated. Overall image quality for coronary arteries was assessed using a five-point scale (1, non-diagnostic; 5, excellent). RESULTS: All the examinations were performed in a single heartbeat. Image noise in the aorta was significantly lower in data sets reconstructed with AIDR than in those reconstructed with FBP (21.4 ± 3.1 HU vs 36.9 ± 4.5 HU; p<0.001). No significant differences were observed between FBP and AIDR for the mean vessel contrast (HU) in the proximal coronary arteries. Consequently, CNRs in the proximal coronary arteries were higher in the AIDR group than in the FBP group (p<0.001). The mean image quality score was improved by AIDR (3.75 ± 0.38 vs 4.24 ± 0.38; p<0.001). CONCLUSION: The use of AIDR reduces image noise and improves image quality in 320-detector row CTCA.


Assuntos
Angiografia Coronária/métodos , Doença da Artéria Coronariana/diagnóstico por imagem , Tomografia Computadorizada Multidetectores/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Índice de Massa Corporal , Protocolos Clínicos , Angiografia Coronária/normas , Feminino , Frequência Cardíaca , Humanos , Masculino , Pessoa de Meia-Idade , Tomografia Computadorizada Multidetectores/normas , Variações Dependentes do Observador , Doses de Radiação , Razão Sinal-Ruído
4.
J Phys Condens Matter ; 22(22): 226003, 2010 Jun 09.
Artigo em Inglês | MEDLINE | ID: mdl-21393754

RESUMO

The hexagonal layered compound, EuPtP, exhibits two valence transitions, at T1 = 235 K and T2 = 190 K, and an antiferromagnetic order at T(N) = 8.6 K. We have examined the effects of magnetic field and pressure, and the specific heat. Analysis of the high-field experiments confirms that half of Eu are in a divalent state at the lowest temperature, and that the number of Eu(² + ) increases discontinuously at T2 and T1 with increasing temperature. The magnetic entropy reaches ~ 22 J K⁻¹ mol⁻¹ at room temperature, which is larger than that expected for J = 7/2 of Eu(²+ ) (17.3 J K⁻¹ mol⁻¹). This is in good agreement with the magnetic entropy deduced from the interconfigurational fluctuation model, which explains the valence transition in Eu(Pd(1- x)Pt(x))2Si2. The application of pressure shifts T1 and T2 higher and suppresses the intermediate phase (ß phase, T2 < T < T1), whereas it does not change the properties of the low-temperature phase (γ phase, T < T2) and the T(N).

5.
Acta Radiol ; 48(2): 173-9, 2007 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-17354138

RESUMO

PURPOSE: To determine the effects of detector configuration, as well as vessel orientation, on the depiction accuracy of arterial stenosis using four-channel multidetector-row helical computed tomography (MDCT) angiography in vitro. MATERIAL AND METHODS: Five acrylic vessel phantoms (3 mm in diameter with 25 or 50% stenosis, or 5 mm with 25, 50, or 75% stenosis) were scanned with a four-channel MDCT scanner at five vessel orientations (0, 30, 45, 60, and 90 degrees to the z-axis) using 4 x 1.25, 2.5, 3.75, and 5.0-mm detector configurations at beam pitches of 0.75 and 1.5. The percentage of stenosis was calculated by the ratio of the full width at half maximum for stenotic and non-stenotic portions of the phantom, and compared to the actual known values. RESULTS: A detector configuration of 4 x 1.25 mm provided good reproducibility, as well as high accuracy for assessing vessel stenosis, while a 4 x 2.5-mm or wider detector configuration caused underestimations of stenosis. Although the phantoms perpendicular to the z-axis were underestimated, the errors were kept in clinically acceptable ranges using the 4 x 1.25-mm detector configuration. CONCLUSION: Four-channel MDCT accurately discerns stenosis for vessel phantoms of 3 or 5 mm in diameter at any orientation when using a detector configuration of 4 x 1.25 mm.


Assuntos
Arteriopatias Oclusivas/diagnóstico por imagem , Imagens de Fantasmas , Tomografia Computadorizada Espiral/métodos , Humanos , Reprodutibilidade dos Testes , Estatísticas não Paramétricas
6.
J Synchrotron Radiat ; 13(Pt 3): 271-4, 2006 May.
Artigo em Inglês | MEDLINE | ID: mdl-16645253

RESUMO

A synchrotron X-ray diffractometer incorporating a pulsed field magnet for high fields up to 40 T has been developed and a detailed description of this instrument is reported. The pulsed field magnet is composed of two coaxial coils with a gap of 3 mm at the mid-plane for passage of the X-rays. The pixel detector PILATUS 100K is used to store the diffracted X-rays. As a test of this instrument, X-ray diffraction by a powder sample of the antiferromagnet CoO is measured below the Néel temperature. A field-dependent lattice distortion of CoO due to magnetostriction is observed up to 38 T.

7.
Phys Rev Lett ; 97(25): 257202, 2006 Dec 22.
Artigo em Inglês | MEDLINE | ID: mdl-17280386

RESUMO

High frequency ESR measurements on the chromium spinel compound CdCr2O4 have been performed. The observed ESR modes below Hc' approximately 5.7 T can be explained well by the calculated resonance modes based on a molecular field theory assuming a helical spin structure. Other than the fundamental ones, we have succeeded in observing the higher-harmonic modes for the first time. A large change of the ESR modes above Hc' indicate that a variation of the spin structure from the helical to the four-sublattice canted one takes place around Hc'.

8.
Br J Anaesth ; 93(2): 199-203, 2004 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-15169741

RESUMO

BACKGROUND: Oesophageal surgery causes morbidity and mortality from respiratory complications. We tested the possibility that prostaglandin E1 (PGE1) could reduce inflammatory cytokine responses and improve gas exchange after oesophagectomy. METHODS: We randomized 14 patients into two groups. One group received PGE1 20 ng kg(-1) min(-1) i.v. during anaesthesia (PGE1 group) and the other group did not (control group). Anaesthesia was maintained with sevoflurane and epidural anaesthesia. During oesophagectomy, ventilation of one lung was carried out with a double-lumen bronchial tube. The patients were extubated on or after the first postoperative day. Blood samples were taken at induction of anaesthesia, at the end of thoracotomy, at the end of the operation, 2 h after surgery and on the first day after surgery. RESULTS: The groups were similar for ASA physical status, age, FEV1%, operation time, duration of thoracotomy, intraoperative fluid volume and blood loss. The arterial blood gas and arterial pressure during surgery were also similar in the PGE1 and control groups. However, the PaO2/FiO2 ratio on the first day after surgery was significantly greater in the PGE1 group compared with the control group. Serum concentrations of IL-6 and IL-8 increased after surgery in both groups. IL-6 was significantly less in the PGE1 group at the end of the operation and 2 h after the operation. CONCLUSIONS: Intraoperative PGE1 reduced IL-6 production in patients undergoing oesophagectomy and oxygenation was better in the postoperative period.


Assuntos
Alprostadil/uso terapêutico , Neoplasias Esofágicas/cirurgia , Interleucina-6/biossíntese , Cuidados Intraoperatórios/métodos , Troca Gasosa Pulmonar/efeitos dos fármacos , Idoso , Esofagectomia , Feminino , Humanos , Interleucina-8/biossíntese , Masculino , Pessoa de Meia-Idade , Oxigênio/sangue , Pressão Parcial , Período Pós-Operatório
10.
Eur Radiol ; 12(2): 357-65, 2002 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11870434

RESUMO

The aim of this study was to determine which morphological features of low-intensity lesions in the peripheral zone of the prostate are predictable of prostate cancer on pre-biopsy T2-weighted integrated endorectal phased-array MR images. The MR examinations were performed in 69 consecutive patients with elevated level of prostate-specific antigen (>4 ng/ml) and/or a positive digital rectal examination before transperineal 12-site biopsy. Two radiologists evaluated presence of lesions, their morphological features, and possibility of malignancy in divided into four sections of the peripheral zone. Imaging analysis findings were compared with biopsy results. Discriminative features were selected by stepwise logistic regression. Descriptive statistics and receiver operating characteristics (ROC) curves were also calculated. Sixty-eight benign lesions and 23 malignant lesions were found. Wedge shape and diffuse extensions without mass effect were significantly associated with benignity ( P=0.0105 and 0.002, respectively). Lesion size was significantly associated with malignancy ( P=0.0001). For evaluating probability of malignancy for lesions, regression model showed a comparable accuracy with the total impression for the readers in ROC analysis (Az 0.9095 vs 0.9266, respectively). Wedge shape, diffuse extension without mass effect, and size are the morphological features of low-intensity lesions in the peripheral zone on pre-biopsy T2-weighted MR images that give the best prediction of malignancy.


Assuntos
Imageamento por Ressonância Magnética/métodos , Próstata/patologia , Neoplasias da Próstata/patologia , Idoso , Idoso de 80 Anos ou mais , Biópsia , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Curva ROC
11.
Stud Health Technol Inform ; 84(Pt 2): 915-8, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11604866

RESUMO

We developed a new PACS linked to Electronic Patient Record system (EPR). It was a hospital-wide PACS storing all the radiological examinations. The images and reports were linked on EPR. The concept of navigation servers and segment servers was introduced for prefetchig and quick displaying. After the start of operation, increasing retrieval indicated its effectiveness on practical work in spite of remaining delivery of radiographs.


Assuntos
Registro Médico Coordenado , Sistemas Computadorizados de Registros Médicos/organização & administração , Sistemas de Informação em Radiologia/organização & administração , Redes de Comunicação de Computadores , Sistemas Computacionais , Sistemas de Informação em Radiologia/estatística & dados numéricos
12.
Ther Apher ; 5(1): 36-9, 2001 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11258608

RESUMO

Multiple organ failure (MOF) is a serious condition that involves simultaneous or consecutive functional failure of several important organs. Furthermore, sepsis is known to play an important role in the occurrence of MOF. Hemoadsorption therapy with the endotoxin adsorption column containing polymyxin B immobilized fibers by direct hemoperfusion (PMX-DHP) is reportedly effective in the treatment of septic shock. This study examined the changes induced on cytokines upon PMX-DHP treatment in 25 patients who underwent emergency abdominal surgery and were immediately started on a postoperative regimen of continuous hemodiafiltration (CHDF) and PMX-DHP. Postoperative MOF was observed in these patients with a mean APACHE II SCORE of 25.5. Eighty percent of patients survived for more than 1 month. We were able to reduce the necessary dose of dopamine in 85.7% of patients because hemodynamic stability improved after administration of PMX-DHP. Interleukin 6 blood levels did not change significantly before or after PMX-DHP treatment in either the surviving or nonsurviving patients. Blood interleukin 1 receptor antagonist levels decreased in both groups. Intercellular adhesion molecular-1, NOx, and thrombomodulin did not change significantly during the course of treatment in either group. Decreased blood levels of PAI-1 levels were found in the surviving patients whereas increased levels of PAI-1 were found in the non-surviving patients. In conclusion, PMX-DHP treatment may be limited clinically in its ability to remove inflammatory cytokines and humoral mediators. However, PMX-DHP treatment is useful for hemodynamic stabilization, which prevents development of MOF.


Assuntos
Antibacterianos/uso terapêutico , Citocinas/isolamento & purificação , Endotoxinas/sangue , Hemodiafiltração/métodos , Hemoperfusão/métodos , Insuficiência de Múltiplos Órgãos/terapia , Polimixinas/uso terapêutico , Complicações Pós-Operatórias/terapia , APACHE , Adsorção , Citocinas/sangue , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Sepse/sangue , Sepse/terapia , Estatísticas não Paramétricas , Taxa de Sobrevida , Resultado do Tratamento
14.
Phys Rev Lett ; 86(2): 324-7, 2001 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-11177822

RESUMO

Susceptibility, ESR, and magnetization measurements have been performed on single crystals of an S = 1 bond alternating chain compound: [Ni(333-tet) (mu-NO2)] (ClO4) (333-tet = N,N'-bis(3-aminopropyl)propane-1,3-diamine) and the compound doped with a small amount of Zn. We observed an anomalous angular dependence in the Zn-doped sample. These results are well explained by the model based on the valence-bond solid picture for the singlet-dimer phase. The picture implies that the free spins of S = 1 with a positive uniaxial single-ion anisotropy are induced at the edges of the chains without forming the singlet dimer.

15.
Radiat Med ; 19(6): 279-84, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11837577

RESUMO

PURPOSE: The aim of this study was to evaluate whether low-dose high-pitch (6:1) multidetector-row helical high-resolution CT is appropriate for the evaluation of various pulmonary abnormalities, including faint opacities. METHODS: Eleven autopsy lungs were scanned with a multidetector-row CT scanner using 2.5 mm x 4 beam collimation, effective slice thickness 3 mm, 6:1 pitch, 0.8 second gantry rotation speed, 20 cm Display FOV, high spatial frequency (bone) algorithm, and various radiation doses (120 kVp; 160, 80, 40, 24, and 8 mAs). The image quality of each CT set was assessed as adequate or inadequate for diagnosis by two independent observers. In addition, a wire phantom was scanned with the same parameters in order to describe the MTF curves. RESULTS: There was excellent agreement between the observers for the evaluation of image quality (kappa statistic, 0.84). The ratio of images evaluated as inadequate for 8 mAs and 24 mAs was significantly higher than that for 160, 80, and 40 mAs (p<0.01: chi-square test). MTF curves of both 8 and 24 mAs were significantly inferior to those of 40, 80, and 160 mAs (p<0.0 1, Friedman test), while the MTF curve of 40 mAs was relatively inferior to that of 160 mAs (p<0.05, Friedman test). CONCLUSION: More than 40 mAs in combination with 120 kVp is preferable for the evaluation of details of lung parenchyma by high-pitch. multidetector-row helical high-resolution CT.


Assuntos
Pulmão/diagnóstico por imagem , Pulmão/patologia , Imagens de Fantasmas , Tomografia Computadorizada por Raios X/métodos , Autopsia , Humanos , Pneumopatias/diagnóstico por imagem , Pneumopatias/patologia , Doses de Radiação , Tomografia Computadorizada por Raios X/instrumentação
16.
Radiat Med ; 19(6): 321-9, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11837585

RESUMO

The goals of this study were (1) to evaluate the quality of compressed lung CT images obtained using high resolution CT (HRCT: 2 mm slice thickness) for degree of compression and conventional CT (10 mm slice thickness) images by using physical and subjective evaluations, and (2) to analyze the distortion of density distribution on lung CT images using histogram analysis for each compression ratio. The coding method was performed according to the Joint Photographic Experts Group (JPEG). We physically evaluated the quality of compressed lung CT images using the peak signal-to-noise ratio (PSNR) as given by the square root of the ratio of the peak value of the gray level squared to the mean square error (dB) and subjectively evaluated the CT images using the mean opinion score (MOS). The acceptable compression ratio for diagnosis was about 1:6 to 1:7 for conventional CT images and about 1:4 to 1:5 for HRCT images as determined by MOS. The PSNR corresponding to acceptable compression ratios was about 50 dB. The difference in density distribution between HRCT and conventional CT was statistically significant (Friedman test: p<0.02) in histogram analysis. Results suggested that, in comparison with conventional CT, a high compression ratio was not suitable for HRCT.


Assuntos
Pneumopatias/diagnóstico , Tomografia Computadorizada por Raios X , Algoritmos , Humanos , Intensificação de Imagem Radiográfica , Processamento de Sinais Assistido por Computador
20.
Abdom Imaging ; 25(5): 511-3, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-10931987

RESUMO

To assess the ability of gadolinium enhancement to suppress the overlapping vessel signals that diminish the image quality of magnetic resonance cholangiopancreatography (MRCP), we obtained MRCP before and after intravenous injection of gadolinium. Signal intensity ratio of the common bile duct to the main pancreatic duct was significantly improved after the injection of contrast media. The image quality of the postcontrast MRCP was better than that of the precontrast one.


Assuntos
Ductos Biliares/patologia , Colangiografia/métodos , Meios de Contraste/administração & dosagem , Imagem Ecoplanar/normas , Gadolínio DTPA/administração & dosagem , Pâncreas/patologia , Adolescente , Adulto , Idoso , Doenças dos Ductos Biliares/diagnóstico , Criança , Diagnóstico Diferencial , Imagem Ecoplanar/métodos , Feminino , Humanos , Injeções Intravenosas , Masculino , Pessoa de Meia-Idade , Variações Dependentes do Observador , Pancreatopatias/diagnóstico , Reprodutibilidade dos Testes
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA