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1.
Hinyokika Kiyo ; 67(8): 395-398, 2021 Aug.
Artigo em Japonês | MEDLINE | ID: mdl-34472323

RESUMO

A 56-year-old man visited a clinic with the chief complaint of frequent micturition and residual sensation of urine. He was referred to our hospital for close examination. Cystoscopy showed a tumor protruding toward the bladder neck from the prostate with stones and debris on the surface. Magnetic resonance imaging showed an encapsulated tumor of iso-intensity in the prostate in T2-weighed images. Prostate specific antigen was 0.88 mg/dl. Transurethral resection of prostate was performed under the diagnosis of benign prostate hyperplasia. During the operation, a solid tumor with mucus deposit was observed. Intraoperative rapid pathological diagnosis was mucinous adenocarcinoma. A radical cystectomy was performed. Pathologically, mucinous adenocarcinoma was distributed in the bladder neck, the prostate and surrounding tissue, but the prostatic urethra was intact. The surgery was assessed to be curative. Neither neoadjuvant nor adjuvant chemotherapy was performed, since the effectiveness of chemotherapy for mucinous adenocarcinoma arising from urothelial epithelium has not been established.


Assuntos
Adenocarcinoma Mucinoso , Neoplasias da Próstata , Ressecção Transuretral da Próstata , Adenocarcinoma Mucinoso/diagnóstico por imagem , Adenocarcinoma Mucinoso/cirurgia , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias da Próstata/diagnóstico por imagem , Neoplasias da Próstata/cirurgia , Bexiga Urinária
2.
J Med Virol ; 2021 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-34524695

RESUMO

Fully automated immunoassays for detecting severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibodies that are strongly correlated with neutralization antibodies (nAbs) are clinically important because they enable the assessment of humoral immunity after infection and vaccination. Access SARS-CoV-2 immunoglobulin M (IgM) and immunoglobulin G (IgG) II antibody tests are semi-quantitative, fully automated immunoassays that detect anti-receptor-binding domain (RBD) antibodies and might reflect nAb levels in coronavirus disease 2019 (COVID-19). However, no studies have investigated the clinical utility of these tests in association with nAbs to date. To evaluate the clinical utility of Access SARS-CoV-2 IgM and IgG II antibody tests and their correlation with the SARS-CoV-2 surrogate virus neutralization test (sVNT) that measures nAbs in patients with COVID-19, we analyzed 54 convalescent serum samples from COVID-19 patients and 89 serum samples from non-COVID-19 patients. The presence of anti-RBD antibodies was detected using Access SARS-CoV-2 IgM and IgG II antibody tests, while nAbs were measured by sVNT. The sensitivity and specificity of sVNT were 94.4% and 98.9%, respectively. There were strong positive correlations between the inhibition values of sVNT and the results of the Access SARS-CoV-2 IgM (R = 0.95, R2 = 0.90, p < 0.001) and IgG II antibody tests (R = 0.96, R2 = 0.92, p < 0.001). In terms of the presence of nAbs, the sensitivity and specificity were 98.1% and 98.9% in the IgM assay and 100.0% and 100.0% in the IgG II assay, respectively. The Access SARS-CoV-2 IgM and IgG II antibody tests showed high sensitivity and specificity for the detection of nAbs in COVID-19 patients and might be alternatives for measuring nAbs.

3.
Int J Infect Dis ; 111: 68-75, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34407480

RESUMO

BACKGROUND: The cross-reactive antibody response against seasonal human coronaviruses (HCoVs) was evaluated according to disease severity in patients with COVID-19 in Japan. METHODS: In total, 194 paired serum samples collected from 97 patients with COVID-19 (mild, 35; severe, 62) were analyzed on admission and during convalescence. IgG antibodies against the nucleocapsid (N) and spike (S) proteins of SARS-CoV-2 and four seasonal HCoVs (HCoV-NL63, -229E, -OC43, and -HKU1) were detected by enzyme-linked immunosorbent assays. RESULTS: There was no difference in optical density (OD) values for seasonal HCoVs on admission between the severe and mild cases. In addition, a specific pattern of disease severity-associated OD values for HCoVs was not identified. Significant increases in OD values from admission to convalescence for HCoV-HKU1and -OC43 IgG-S, and for HCoV-NL63 and -229E IgG-N were observed in the severe cases. Significant differences were observed between the mild and severe cases for HCoV-HKU1 and -OC43 IgG-S OD values during convalescence. Correlations were found between the fold changes for HCoV-OC43 IgG-S OD values, and for SARS-CoV-2 IgG-S OD values, and C-reactive protein, lactate dehydrogenase, and lymphocyte levels. CONCLUSION: There was no association between the antibody titer for seasonal HCoVs in the early phase of COVID-19 and disease severity.


Assuntos
COVID-19 , Humanos , Imunidade Humoral , SARS-CoV-2 , Estações do Ano , Índice de Gravidade de Doença , Glicoproteína da Espícula de Coronavírus
4.
J Med Virol ; 93(12): 6778-6781, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34170555

RESUMO

A high-throughput, fully automated antigen detection test for SARS-CoV-2 is a viable alternative to reverse-transcription polymerase chain reaction (RT-qPCR) for mass screening during outbreaks. In this study, we compared RT-qPCR for viral load and the VITROS® SARS-CoV-2 Antigen Test with reference to the results of the LUMIPULSE® SARS-CoV-2 Ag Test. Of 128 nasopharyngeal swab specimens taken from patients suspected of being infected with SARS-CoV-2, 49 were positive and 79 were negative according to RT-qPCR. Consistent dose-dependent detection with VITROS® assay was successfully achieved when using nasopharyngeal swab specimens with Ct values of 32.0 or lesser, whereas the CLEIA-based LUMIPULSE® assay was able to detect lower viral loads compared with the VITROS® assay. Our results show that the performance of the VITROS® assay was satisfactory for the diagnosis of contagious COVID-19 patients in the clinical setting. Highlights The performance of the VITROS® SARS-CoV-2 Antigen Test was sufficient for the diagnosis of contagious COVID-19. This test showed high sensitivity and specificity in the detection of SARS-CoV-2 in samples with a Ct value of 32 or less.

6.
Curr Oncol ; 28(2): 1294-1301, 2021 03 22.
Artigo em Inglês | MEDLINE | ID: mdl-33809967

RESUMO

This study aimed to determine the predictive value of the Prostate Imaging Reporting and Data System version 2 (PI-RADS v2) based on biparametric magnetic resonance imaging (bpMRI) with combined target biopsy (TBx) and systematic biopsy (SBx) in patients with suspicion of having clinically significant prostate cancer (csPCa). In this retrospective study, we reviewed the clinical and pathological records of 184 consecutive patients who underwent bpMRI before prostate biopsy. We focused on patients with PI-RADS v2 scores ≥ 3. MRI was performed using a 3-Tesla clinical scanner with a 32-channel phased-array receiver coil. PI-RADS v2 was used to describe bpMRI findings based on T2-weighted imaging and diffusion-weighted imaging scores. The primary endpoint was the diagnostic accuracy rate of PI-RADS v2 based on bpMRI for patients with prostate cancer (PCa) who underwent combined TBx and SBx. A total of 104 patients were enrolled in this study. Combined TBx and SBx was significantly superior to either method alone for PCa detection in patients with suspicious lesions according to PI-RADS v2. TBx and SBx detected concordant csPCa in only 24.1% of the patients. In addition, the rate of increase in the Gleason score was similar between SBx (41.5%) and TBx (34.1%). The diagnostic accuracy of bpMRI is comparable to that of standard multiparametric MRI for the detection of csPCa. Moreover, combined TBx and SBx may be optimal for the accurate determination of csPCa diagnosis, the International Society of Urological Pathology grade, and risk classification.


Assuntos
Imageamento por Ressonância Magnética , Neoplasias da Próstata , Humanos , Biópsia Guiada por Imagem , Masculino , Neoplasias da Próstata/diagnóstico por imagem , Estudos Retrospectivos
7.
Diagn Microbiol Infect Dis ; 100(3): 115370, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33744623

RESUMO

Several automated high-throughput immunoassays for detecting anti-SARS-CoV-2 antibodies by a semi-quantitative approach have been commercialized. In this study, we describe the timeline of the antibody response in patients with RT-PCR-confirmed COVID-19. A total of 292 sequential serum samples from 33 Japanese patients were retrospectively analyzed using four test kits for SARS-CoV-2: the Abbott SARS-CoV-2 IgG assay (Abbott), Elecsys® Anti-SARS-CoV-2 assay (Roche Diagnostic), and VITROS® Anti-SARS-CoV-2 Total and IgG assays (Ortho Clinical Diagnostics). All automated immunoassays could equivalently identify positive sera collected within 2 weeks after symptom onset (99.3%-100%). In addition, the S protein-based automated immunoassay, the VITROS® Anti-SARS-CoV-2 Total assay, may play a complementary role in evaluating passive antibody therapies or vaccines against SARS-CoV-2, although further research is required.


Assuntos
Anticorpos Antivirais/sangue , Teste Sorológico para COVID-19/métodos , COVID-19/diagnóstico , SARS-CoV-2/imunologia , Adulto , Idoso , COVID-19/imunologia , Feminino , Ensaios de Triagem em Larga Escala , Humanos , Imunoensaio , Cinética , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , SARS-CoV-2/isolamento & purificação , Sensibilidade e Especificidade
8.
J Med Virol ; 93(5): 3211-3218, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33620098

RESUMO

We analyzed antibody response patterns according to the level of disease severity in patients with novel coronavirus disease 2019 (COVID-19) in Japan. We analyzed 611 serum specimens from 231 patients with COVID-19 (mild, 170; severe, 31; critical, 30). Immunoglobulin M (IgM) and IgG antibodies against nucleocapsid protein (N) and spike 1 protein (S1) were detected by enzyme-linked immunosorbent assays. The peaks of fitting curves for the optical density (OD) values of IgM and IgG antibodies against N appeared simultaneously, while those against S1 were delayed compared with N. The OD values of IgM against N and IgG against both N and S1 were significantly higher in the severe and critical cases than in the mild cases at 11 days after symptom onset. The seroconversion rates of IgG were higher than those of IgM against both N and S1 during the clinical course based on the optimal cut-off values defined in this study. The seroconversion rates of IgG and IgM against N and S1 were higher in the severe and critical cases than in the mild cases. Our findings show that a stronger antibody response occurred in COVID-19 patients with greater disease severity and there were low seroconversion rates of antibodies against N and S1 in the mild cases.


Assuntos
Anticorpos Antivirais/sangue , COVID-19/epidemiologia , COVID-19/imunologia , SARS-CoV-2/imunologia , Anticorpos Antivirais/classificação , COVID-19/patologia , Humanos , Imunoglobulina G/sangue , Imunoglobulina G/classificação , Imunoglobulina M/sangue , Imunoglobulina M/classificação , Japão/epidemiologia
10.
Anaerobe ; 64: 102215, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32574601

RESUMO

The in vitro susceptibilities of Bacteroides fragilis to antimicrobial agents, especially to carbapenem, are a major concern in the treatment of patients with bloodstream infections. In this study, 50 isolates of B. fragilis were obtained from positive blood bottles from 2014 to 2019 in Saitama, Japan. Their susceptibility to ampicillin/sulbactam was reduced to 70.0% compared with a previous report, whereas they were still sufficiently susceptible to piperacillin/tazobactam (94.0%). Five cfiA-positive isolates (5/50, 10.0%) were identified that were resistant to doripenem and meropenem, and two of them carried an insertion sequence located upstream of the cfiA-coding region. In particular, imipenem should be considered as a first-line carbapenem for the empirical treatment of B. fragilis infection because only insertion sequence and cfiA double-positive strains showed resistance to imipenem. Thirty-six percent of the isolates had a reduced minimum inhibitory concentration for moxifloxacin. In addition, metronidazole should still be considered as an active agent for B. fragilis because all isolates were susceptible to this antibiotic and the prevalence of the nim gene was low in Japan.


Assuntos
Antibacterianos/farmacologia , Infecções por Bacteroides/epidemiologia , Bacteroides fragilis/efeitos dos fármacos , Bacteroides fragilis/genética , Farmacorresistência Bacteriana Múltipla/genética , beta-Lactamases/genética , Ampicilina/farmacologia , Proteínas de Bactérias , Infecções por Bacteroides/microbiologia , Hemocultura/instrumentação , Elementos de DNA Transponíveis , Doripenem/farmacologia , Genes Bacterianos , Humanos , Imipenem/farmacologia , Japão/epidemiologia , Meropeném/farmacologia , Metronidazol/farmacologia , Testes de Sensibilidade Microbiana , Moxifloxacina/farmacologia , Combinação Piperacilina e Tazobactam/farmacologia , Prevalência , Sulbactam/farmacologia , Centros de Atenção Terciária
11.
J Clin Virol ; 129: 104446, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32512376

RESUMO

With the rapid spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), there is an urgent need for more rapid and simple detection technologies at the forefront of medical care worldwide. In this study, we evaluated the effectiveness of the Loopamp® 2019-SARSCoV-2 Detection Reagent Kit, which uses loop-mediated isothermal amplification (LAMP) technology. In this protocol, cDNA is synthesized from SARS-CoV-2 RNA using reverse transcriptase, followed by DNA amplification under isothermal conditions in one step. The RT-LAMP test kit amplified the targeted RNA of a SARS-CoV-2 isolate with a detection limit of 1.0 × 101 copies/µL, which was comparable to the detection sensitivity of quantitative reverse transcription PCR (RT-qPCR). Comparison with the results of RT-qPCR for 76 nasopharyngeal swab samples from patients with suspected COVID-19 showed a sensitivity of 100 % and a specificity of 97.6 %. In the 24 RNA specimens derived from febrile Japanese patients with or without influenza A, no amplification was observed using RT-LAMP. RT-LAMP could be a simple and easy-to-use diagnostic tool for the detection of SARS-CoV-2.


Assuntos
Betacoronavirus/isolamento & purificação , Técnicas de Laboratório Clínico/métodos , Infecções por Coronavirus/diagnóstico , Técnicas de Diagnóstico Molecular/métodos , Técnicas de Amplificação de Ácido Nucleico/métodos , Pneumonia Viral/diagnóstico , Betacoronavirus/genética , COVID-19 , Teste para COVID-19 , Humanos , Japão , Pandemias , SARS-CoV-2 , Sensibilidade e Especificidade , Fatores de Tempo
12.
Hinyokika Kiyo ; 66(3): 81-85, 2020 Mar.
Artigo em Japonês | MEDLINE | ID: mdl-32316703

RESUMO

A 50-year-old man was diagnosed with right staghorn calculus. Urine cytology showed atypical cells, and he was followed for suspicion of urothelial carcinoma. However, there was no evidence of tumor six months later, and percutaneous nephrolithotripsy (PNL) was performed for right staghorn calculus. Eight months later, renal pelvic squamous cell carcinoma extending to the abdominal wall through the nephrostomy tract was identified. After neoadjuvant chemotherapy, radical nephroureterectomy and enbloc resection of the nephrostomy tract tumor was performed. The renal pelvic squamous cell carcinoma did not recur. However he died of small cell lung cancer 3 years postoperatively. Planning of treatment strategy was difficult in the present case. Even though PNL was performed after sufficient follow up and examination, renal pelvic cancer could not be diagnosed and extended to the PNL tract. Fortunately, radical en-bloc resection was possible. We herein, report a case of renal pelvic squamous cell carcinoma after PNL.


Assuntos
Carcinoma de Células Escamosas , Carcinoma de Células de Transição , Neoplasias Renais , Nefrostomia Percutânea , Humanos , Pelve Renal , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia , Nefrotomia
13.
J Med Ultrason (2001) ; 47(2): 193-201, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32026128

RESUMO

PURPOSE: The effects of low-intensity pulsed ultrasound (LIPUS) on the expression of immediate-early genes (IEGs) in bone marrow stromal cells (BMSCs) were evaluated to elucidate the early cellular response to LIPUS. METHODS: Mouse ST2 BMSCs were treated with LIPUS (ISATA, 12-34 mW/cm2 for 20 min), then cultured at 37 °C. The expression levels of four IEGs (Fos, Egr1, Jun, and Ptgs2) and ERK1/2, a mitogen-activated protein kinase/extracellular signal-regulated kinase (MAPK/ERK), were assessed using real-time quantitative PCR and Western blot analyses, respectively. RESULTS: A single exposure of LIPUS at an intensity of 25 mW/cm2 significantly and transiently increased the expression levels of all four IEGs, and the peak expression was detected at 30-60 min after LIPUS stimulation. LIPUS exposure also significantly increased the phosphorylation level of ERK1/2. U0126, an inhibitor of MAPK/ERK, significantly prevented LIPUS-induced expression of Fos and Egr1, but not that of Jun and Ptgs2. On the other hand, treatment of the cells with LIPUS did not affect cell growth or alkaline phosphatase activity, a marker of osteoblast differentiation. CONCLUSION: These results suggest that LIPUS exposure significantly induces expression of IEGs such as Fos and Egr1 via the MAPK/ERK pathway in ST2 BMSCs.


Assuntos
Expressão Gênica/fisiologia , Genes Precoces/fisiologia , Proteína 1 Semelhante a Receptor de Interleucina-1/genética , Células-Tronco Mesenquimais/fisiologia , Ondas Ultrassônicas , Animais , Diferenciação Celular , Proliferação de Células , Células Cultivadas , Camundongos
14.
BMC Infect Dis ; 19(1): 946, 2019 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-31703559

RESUMO

BACKGROUND: Klebsiella variicola and K. quasipneumoniae are new species distinguishable from K. pneumoniae but they are often misidentified as K. pneumoniae in clinical settings. Several reports have demonstrated the possibility that the virulence factors and clinical features differ among these three phylogroups. In this study, we aimed to clarify whether there were differences in clinical and bacterial features between the three phylogroups isolated from patients with bloodstream infections (BSIs) in Japan. METHODS: Isolates from all patients with BSIs caused by K. pneumoniae admitted to two hospitals between 2014 and 2017 (n = 119) were included in the study. Bacterial species were identified via sequence analysis, and their virulence factors and serotypes were analyzed via multiplex PCR results. Clinical data were retrieved from medical records. RESULTS: Of the 119 isolates, 21 (17.7%) were identified as K. variicola and 11 (9.2%) as K. quasipneumoniae; K1 serotype was found in 16 (13.4%), and K2 serotype in 13 (10.9%). Significant differences in the prevalence of rmpA, iutA, ybtS, entB and kfu (p < 0.001), and allS genes (p < 0.05) were found between the three phylogroups. However, there were no significant differences in clinical features, including the 30-day mortality rate, between the three organisms, although K. variicola was more frequently detected in patients over 80 years old compared with other Klebsiella species (p < 0.005), and K. quasipneumoniae more frequently occurred in patients with malignancy (p < 0.05). CONCLUSIONS: Our findings demonstrated the differences in bacterial pathogenicity and clinical features among these three phylogroups. Further epidemiological studies into BSI caused by Klebsiella species are warranted.


Assuntos
Bacteriemia/microbiologia , Infecções por Klebsiella/microbiologia , Infecções por Klebsiella/mortalidade , Klebsiella pneumoniae/genética , Klebsiella/genética , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Doença Iatrogênica , Japão , Klebsiella/isolamento & purificação , Klebsiella pneumoniae/isolamento & purificação , Masculino , Filogenia , Reação em Cadeia da Polimerase , Estudos Retrospectivos , Fatores de Risco , Sorogrupo , Fatores de Virulência/genética
15.
Hinyokika Kiyo ; 65(6): 197-201, 2019 Jun.
Artigo em Japonês | MEDLINE | ID: mdl-31501385

RESUMO

The patient underwent laparoscopic left radical nephrectomy for clear cell renal cell carcinoma (ccRCC). After surgery, the patient had multiple lung metastases and underwent the combination therapy of radiofrequency ablation, interferon-alpha, and inteleukin-2. Thereafter, computed tomography showed multiple lymph node and brain metastases. The patient was administered targeted therapy and radiation. Eventually, the patient suddenly complained of dyspnea. An echocardiogram, coronary angiography and magnetic resonance imaging suggested acute heart failure and pericardial effusion due to a metastatic tumor in the cardiac anteroseptal and posterior wall. Nivolumab was administered for cardiac metastases. The patient has been in stable condition with no progression of cardiac metastases after the administration of nivolumab for 22 months.


Assuntos
Carcinoma de Células Renais , Neoplasias Cardíacas , Neoplasias Renais , Carcinoma de Células Renais/secundário , Carcinoma de Células Renais/terapia , Terapia Combinada , Neoplasias Cardíacas/secundário , Neoplasias Cardíacas/terapia , Humanos , Neoplasias Renais/patologia , Neoplasias Renais/terapia , Nefrectomia
16.
Artigo em Inglês | MEDLINE | ID: mdl-28436860

RESUMO

A novel tough hydrophone was fabricated by depositing hydrothermally synthesized lead zirconate titanate polycrystalline film on the back-side surface of a titanium plate. Our developed tough hydrophone resisted damage in a high-pressure field (15 MPa) at a focal point of a sinusoidal continuous wave driven by a concave high-intensity focused ultrasound (HIFU) transducer with up to 50 W of power input to the sound source. The hydrophone was suitable for the HIFU field, even though the hydrophone has a flat-shape tip of 3.5 mm diameter, which is slightly larger than the wavelength of a few megahertz. In this paper, experiments are performed to assess the effect on the HIFU field of changing the shape of the tough hydrophone, with the aim of developing a tough hydrophone. The spatial distribution of the acoustic bubbles around the focal point was visualized by using ultrasonic diagnostic equipment with the tough hydrophone located at the focal point of the HIFU transducer. From the visualization, the trapped acoustic bubbles were seen to arise from the standing wave, which implies that the acoustic pressure is reduced by this cloud of acoustic bubbles that appeared during hydrophone measurement. Although cavitation and acoustic bubbles may be unavoidable when using high-intensity ultrasound, the estimated result of evaluating acoustic fields without misunderstanding by acoustic bubbles can be obtained by the aid of visualizing bubbles around the tough hydrophone.

17.
AIP Adv ; 6(3): 035102, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-27014504

RESUMO

Single-beam acoustic tweezers (SBAT), used in laboratory-on-a-chip (LOC) device has promising implications for an individual micro-particle contactless manipulation. In this study, a freestanding hydrothermal PZT thick film with excellent piezoelectric property (d33 = 270pC/N and kt = 0.51) was employed for SBAT applications and a press-focusing technology was introduced. The obtained SBAT, acting at an operational frequency of 50MHz, a low f-number (∼0.9), demonstrated the capability to trap and manipulate a micro-particle sized 10µm in the distilled water. These results suggest that such a device has great potential as a manipulator for a wide range of biomedical and chemical science applications.

18.
Artigo em Inglês | MEDLINE | ID: mdl-23549547

RESUMO

The paper describes the design, fabrication, and measurements of a high-frequency ultrasound kerfless linear array prepared from hydrothermal lead zirconate titanate (PZT) thick film. The 15-µm hydrothermal PZT thick film with an area of 1 × 1 cm, obtained through a self-separation process from Ti substrate, was used to fabricate a 32-element 100-MHz kerfless linear array with photolithography. The bandwidth at -6 dB without matching layer, insertion loss around center frequency, and crosstalk between adjacent elements were measured to be 39%, -30 dB, and -15 dB, respectively.

19.
J Med Ultrason (2001) ; 39(3): 107-13, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27278970

RESUMO

PURPOSE: The Ultrasound Equipment and Safety Committee of The Japan Society of Ultrasonics in Medicine performed experiments to confirm whether contrast-enhanced ultrasonography damages liver cells. METHODS: Rats were injected with 0.1 ml of 300 mg/ml ultrasound contrast agent (UCA). Diagnostic ultrasound pulses with a center frequency of 6 MHz and a mechanical index of 1.9 were applied to rat livers with a water bag as a coupler to maintain a distance of 2-6 cm between the ultrasound probe surface and the liver. Contrast-enhanced ultrasonography was carried out for 10 s to visualize the entire liver. Then, specimens of liver tissue were fixed using two types of fixation: immersion and perfusion fixation. RESULTS: Although some variations were found in electron micrographs of liver tissue fixed using immersion fixation, none of three blinded readers found any significant differences between micrographs of liver tissue from rats receiving UCA with sonication and those from sham-treated control rats. Changes observed were not thought to be group-specific but instead due to differences between individual rats. When the livers were fixed using perfusion fixation and the hepatic vein was cut after injection of physiological saline for perfusion, a large number of vacuoles ≥2 µm in diameter were observed. This finding suggested that hepatic cell damage observed in this study was caused by high perfusion pressure during the liver fixation process rather than by sonication with UCA. CONCLUSION: Blinded readings of electron micrographs showed no clear evidence that the use of Levovist in ADI mode ultrasonography causes significant damage to liver tissue.

20.
J Mater Res ; 26(11): 1431-1435, 2011 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-21852893

RESUMO

Self-separated Pb(Zr(0.52)Ti(0.48))O(3) (PZT) films were processed by a hydrothermal deposition and a rapid thermal separation method, followed by a sol-gel filling and sintering process. The films possess excellent piezoelectric and electromechanical properties close to those of bulk material. The maximum remnant polarization is over 30 µC/cm(2) and the electromechanical coupling factor (k(t)) reaches as high as 0.52. The unique microstructure characteristics of the PZT films, such as their highly dense structure, columnar grains, well-connected grain boundaries, and well-dispersed nanopores, could all contribute to the enhanced piezoelectric and electromechanical properties.

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