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排序方式: 共有748条查询结果,搜索用时 15 毫秒
1.
Stephen R. Thomas Ronald G. Pratt Ronald W. Millard R. C. Samaratunga Yoseph Shiferaw Leland C. Clark Richard E. Hoffmann 《Journal of magnetic resonance imaging : JMRI》1994,4(4):631-635
Oxygen-sensitive F-19 magnetic resonance imaging of perfluorocarbon compounds requires that fluorocarbon T1 changes correlate with the local Po2 and not with the composition of the surrounding aqueous phase. The influence of various bioconstituents and paramagnetic ions within the aqueous phase on the F-19 fluorocarbon phase T1 for PFC emulsions was evaluated at 0.14 and 0.66 T. T1 was measured for FC-43, perflubron, and a fluorinated surfactant. Controlled variables introduced in the aqueous phase included annex solution constituents, blood, pH changes, and Gd-DTPA. For a constant Po2, the F-19 T1s were independent of the emulsion constituents, blood concentration, and pH. For FC-43 and perflubron, F-19 T1 was independent of the Gd-DTPA concentration, while the aqueous phase T1 decreased by more than an order of magnitude. XMO-10 (smallest emulsion particle size) showed a slight decrease in F-19 T1 with increasing Gd-DTPA concentration at 0.66 T. 相似文献
2.
3.
Ronald G. Pratt Jie Zheng Brent K. Stewart Yoseph Shiferaw Anthony J. McGoron Ranasinghage C. Samaratunga Stephen R. Thomas 《Magnetic resonance in medicine》1997,37(2):307-313
A limited flip angle gradient-echo 3D volume acquisition imaging protocol for mapping partial pressure of oxygen (pO2) in perfluorocarbon compounds (PFCs) at low field (0.14 T) is presented. The pO2 measurement method is based on the paramagnetic effect of dissolved molecular oxygen (O2) which reduces the PFC 19F T1? Specific objectives related to imaging of PFCs through use of the protocol include improved image signal-to-noise characteristics and elimination of 19F chemical shift artifacts. A parametric Wiener deconvolution filtering algorithm is used for suppression of 19F chemical shift artifacts. Application of the protocol is illustrated in a series of calculated pO2 maps of a gas equilibrated, multi-chamber phantom containing perfluorotributylamine (FC-43). The utility of the protocol is demonstrated in vivo through images of a commercially available perfluorocarbon based blood substitute emulsion containing FC-43 sequestered in the liver and spleen of a rat. 相似文献
4.
R. A. Gardiner M. L. T. H. Samaratunga M. D. Walsh G. J. Seymour M. F. Lavin 《Urological research》1992,20(2):117-120
Summary Sections of formalin-fixed, paraffin-blocked tissue from 116 primary transitional cell carcinomas were stained immunohistochemically using a polyclonal antibody against the c-erbB-2 oncoprotein. Positive staining of cell membranes, known to correlate with gene amplification, was seen in 22 (19%) of the 116, with variable staining from tumour to tumour and within tumours themselves. Consistent with its mooted value as a prognosticator in bladder cancer, the c-erbB-2 oncoprotein was detected in 13 (of 40) grade III and 9 of the 26 muscle-invasive tumours examined compared to 1 (of 25) grade I and 6 (of 66) mucosa only (pTa) lesions. These results support further examination of c-erbB-2 expression in bladder cancer. 相似文献
5.
A 39-year-old woman died of encephalitis a few weeks after being scratched by fruit bats. Autopsy disclosed meningoencephalomyelitis, and revealed neuronal intracytoplasmic inclusions which had similarities to Negri bodies of rabies. Laboratory investigations detected a Lyssavirus type previously identified only in fruit bats. This appears to be the first human case of encephalitis due to this Lyssavirus type. 相似文献
6.
7.
Treaba D Assad L Govil H Sariya D Reddy VB Kluskens L Green L Selvaggi SM Gattuso P 《Diagnostic cytopathology》2002,26(6):380-383
At the present time fine-needle aspiration (FNA) is considered a routine diagnostic procedure in evaluating neoplastic vs. nonneoplastic lesions in many organs, with high sensitivity and specificity. The purpose of this study was to assess the utility of FNA in areas of diagnostic difficulty and its limitations in evaluating bone lesions in patients with a previous history of malignancy. From 1989 to 2000, 249 CT-guided FNAs of bone lesion were performed at our institutions; 187/249 (75.1%) patients had a previous history of malignancy. Aspirated material was air-dried for Diff-Quik stain or fixed in ethanol for Papanicolaou staining. Subsequent surgical tissue was available in 69/187 (36.9%) of the cases. There were 114 males and 73 females, ages 14-86 yr (mean, 64 yr). The primary tumor site was lung 49, genitourinary 46, breast 31, gastrointestinal 28, hematopoietic 26, soft tissue/skin 5, and thyroid 2. There were 125 FNAs of the vertebral spine, 19 from the pelvis, 11 from the ribs, 9 from the sternum, 5 from the femur, and 18 from miscellaneous bone sites. Out of 187, 166 (88.7%) were malignant aspirates confirming the patients' primary malignancies. The most common malignancy encountered was adenocarcinoma, 126/187 (67.4%). Surgical tissue was available for review in 69 patients and the results were in agreement with the FNAs diagnosis in all cases. Nine out of 187 (4.8%) cases were diagnosed as marrow elements on cytological material. These patients have been followed for 1-9 yr and have failed to reveal signs or symptoms of clinical recurrence. Three out of 187 (1.6%) cases showed osteomyelitis. Nine out of 187 (4.8%) were unsatisfactory specimens, with biopsy follow-up available in four cases, showing three metastatic tumors and one case of osteomyelitis. FNA of metastatic bone lesions is a major step in pretreatment diagnosis. On satisfactory specimens, the cytological diagnosis viewed in the clinical-radiological context proves to be similar to surgical diagnosis. FNA is an excellent technique with a high accuracy rate in assessing metastatic bone lesions. 相似文献
8.
Summary. A virus isolate causing mosaic disease of commercial sugarcane was purified to homogeneity. Electron microscopy revealed
flexuous filamentous virus particles of ca 890 × 15 nm. The virus isolate reacted positively with heterologous antiserum to
narcissus latent virus form UK, but failed to react with potyvirus group specific antiserum. N-terminal sequencing of the
intact coat protein (CP) and the tryptic peptides indicated that the virus was probably a potyvirus but distinct from several
reported potyviruses. Comparison of the 3′-terminal 1084 nucleotide sequence of the RNA genome of this virus revealed 93.6%
sequence identity in the coat protein coding region with the recently described sugarcane streak mosaic virus (Pakistani isolate).
The molecular weight of the coat protein (40 kDa) was higher than that deduced from the amino acid sequence (34 kDa). The
apparent increase in size was shown to be due to glycosylation of the coat protein which has not been reported thus far in
the family, Potyviridae. This is the first report on the molecular characterization of a virus causing mosaic disease of sugarcane in India and the
results demonstrate that the virus is a strain of sugarcane streak mosaic virus, a member of the Tritimovirus genus of the Potyviridae. We have named it sugarcane streak mosaic virus – Andhra Pradesh isolate (SCSMV-AP).
Received October 14, 1997 Accepted August 7, 1998 相似文献
9.
Micropapillary variant of urothelial carcinoma of the urinary bladder; a clinicopathological and immunohistochemical study 总被引:5,自引:0,他引:5
AIMS: To investigate whether prognosis in micropapillary urothelial carcinoma is related to the proportion of the micropapillary component (MPC), and to identify the immunohistochemical features of MPC. METHODS AND RESULTS: This study presents a clinicopathological analysis of 20 patients with micropapillary urothelial carcinoma of the bladder with cystectomy specimens for evaluation. Tumours were stratified on the extent of MPC: focal, <10%; moderate, 10-50%; extensive, >50%; and this was correlated with tumour stage and prognosis. Sixteen males and four females were aged 56-81 years (mean 69 years). All cases had high-grade morphology in the micropapillary carcinoma and typical urothelial carcinoma. All cases with extensive MPC (n = 4) were of a high pathological stage (pT3 or pT4) and died of disease (DOD) or other causes. Eighty percent with moderate MPC (eight of 10 cases) were pT3 or pT4 and 50% DOD or are alive with disease. Eighty-four percent with focal MPC (five of six cases) were pT1 or pTa. In high-stage cases, the most invasive component was MPC. High-stage cases had an 85% risk of being advanced at presentation with micropapillary carcinoma. All pT2 or lower stage cases had micropapillary carcinoma on prior transurethral resections of bladder tumour (TURB). High-stage carcinomas had 30% and 54%, respectively, of surface MPC and urothelial carcinoma in situ, in comparison with 85% and 28% in lower stage carcinomas. Immunohistochemical staining was similarly positive in MPC and typical urothelial carcinoma with cytokeratin (CK)7, CK20, epithelial membrane antigen, carcinoembryonic antigen and cytokeratin 34betaE12. CA125 staining was seen only in MPC in 43% of cases. CONCLUSIONS: Micropapillary urothelial carcinoma is a high-grade carcinoma in which the prognosis is related to the proportion and location of the MPC. Cases with moderate or extensive MPC are at high risk of being advanced at presentation. Cases with <10% MPC and surface MPC have a high chance of detection at an early stage. The morphology and immunohistochemical profile of the MPC suggest that it is a form of glandular differentiation in urothelial carcinoma. 相似文献
10.
Capillaria hepatica parasitism 总被引:1,自引:0,他引:1
Capillaria hepatica is rarely encountered in humans, with fewer than 30 documented cases. The clinico-pathological features
of capillaria hepatica infection, diagnosed on liver biopsy of a 6-year-old child are discussed. Pathologically, it is characterised
by prominent granulomatous lesions in the liver surrounding the eggs, which on cursory examination may be confused withSchistosoma mansoni. 相似文献