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排序方式: 共有238条查询结果,搜索用时 12 毫秒
71.
Brenda Deyarmin HT Jennifer L. Kane HT Allyson L. Valente BS Ryan van Laar PhD Christopher Gallagher MD Craig D. Shriver MD Rachel E. Ellsworth PhD 《Annals of surgical oncology》2013,20(1):87-93
Background
Determination of estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2) status is standard for predicting prognosis and determining treatment options for patients with breast cancer. In 2010, the American Society of Clinical Oncology (ASCO) and College of American Pathologists (CAP) issued guidelines that tumors with ≥1 % positively staining cells should be considered ER positive. Here, we determined how this cutoff relates to molecular subtype.Methods
Clinicopathological characteristics were compared between ER-negative, ER-positive, and low-ER-staining (1–10 %) tumors using chi-square analysis with P < 0.05 defining statistical significance. Gene expression data were generated for 26 low-ER-staining tumors, and their intrinsic subtype determined. Immunohistochemistry (IHC)-defined surrogate subtypes, using the threshold of positivity defined by ASCO/CAP guidelines, were compared with molecular subtypes.Results
Low-ER-staining tumors were clinicopathologically more similar to ER-negative than to ER-positive tumors; 88 % of low-staining tumors were basal like or HER2 enriched. Only those tumors expressing 10 % ER-positive cells were classified as luminal A subtype.Conclusions
Under ASCO/CAP guidelines, tumors with 1–10 % ER staining would be classified as ER positive, yet most are basal like or HER2 enriched and have pathological features similar to ER-negative tumors. Clinical trials seeking to treat tumors of ER-negative basal-like and/or HER2-enriched subtypes should thus not preclude enrollment based solely on results of ER immunohistochemistry. As ER status is a critical element in the choice of treatments for patients with breast cancer, it is imperative that the most effective method for classifying tumors be developed. 相似文献72.
Rashid Ghaznawi Jet MJ Vonk Maarten HT Zwartbol Jeroen de Bresser Ina Rissanen Jeroen Hendrikse Mirjam I Geerlings 《Journal of cerebral blood flow and metabolism》2023,43(2):309
Asymptomatic low-grade carotid artery stenosis (LGCS) is a common finding in patients with manifest arterial disease, however its relationship with brain MRI changes and cognitive decline is unclear. We included 902 patients (58 ± 10 years; 81% male) enrolled in the Second Manifestations of Arterial Disease – Magnetic Resonance (SMART-MR) study without a history of cerebrovascular disease. LGCS was defined as 1–49% stenosis on baseline carotid ultrasound, whereas no LGCS (reference category) was defined as absence of carotid plaque. Brain and white matter hyperintensity (WMH) volumes and cognitive function were measured at baseline and after 4 (n = 480) and 12 years (n = 222) of follow-up. Using linear mixed-effects models, we investigated associations of LGCS with progression of brain atrophy, WMH, and cognitive decline. LGCS was associated with greater progression of global brain atrophy (estimate −0.03; 95%CI, −0.06 to −0.01; p = 0.002), and a greater decline in executive functioning (estimate −0.02; 95%CI, −0.031 to −0.01; p < 0.001) and memory (estimate −0.012; 95%CI, −0.02 to −0.001; p = 0.032), independent of demographics, cardiovascular risk factors, and incident brain infarcts on MRI. No association was observed between LGCS and progression of WMH. Our results indicate that LGCS may represent an early marker of greater future brain atrophy and cognitive decline. 相似文献
73.
74.
David Tran Martin Golick HT Harold Rabinovitz MD Daniel Rivlin MD George Elgart MD Barbara Nordlow HT 《Dermatologic surgery》2000,26(3):197-199
Currently the hematoxylin and eosin staining procedure is the most popular among Mohs surgeons for histology. However, safranin O, a cheaper and relatively safer stain which is predominantly used for plant histology, should be considered as it offers similar or improved accuracy in the diagnosis of frozen sections of basal and squamous cell carcinomas. 相似文献
75.
76.
萘甲异喹(NI)呈浓度依赖性地降低离体豚鼠心房收缩力和频率。其拮抗豚鼠左房肌Iso正性肌力作用的PD22′值为5.4,Ver为5.8。NI10μmol/L明显降低豚鼠乳头肌收缩力;缩短快反应APD,以对APD20影响最大,但不影响APA和Vmax。对高K+去极化慢反应动作电位,NI产生浓度依赖性负性肌力作用,同时明显降低APA,Vmax,缩短APD;提高细胞外液Ca2+浓度可使其抑制作用逆转。结果提示NI具有钙通道阻滞作用。 相似文献
77.
Volume calculation by means of SPECT: analysis of imaging acquisition and processing factors 总被引:1,自引:0,他引:1
To assess the effect of image acquisition and processing factors on the volume calculated from single photon emission computed tomography (SPECT) images, the authors evaluated technical factors including image matrix size, size of the region of interest (ROI), activity concentration in the region, amount of background subtraction, type of reconstruction filter, section thickness, and number of projections. They found that the percentage of background subtraction was the single most important factor affecting volume calculation. The smaller the volume, the greater the amount of background subtraction needed before the ROI is drawn. As an acceptable means to circumvent the varying percentage of background subtraction for different volumes, a calibration curve was constructed relating the true volume with the calculated volume for a fixed percentage of background subtraction. The use of a 128 X 128 acquisition matrix and zooming of the reconstructed images were necessary for accurate calculation of volumes smaller than 300 mL. 相似文献
78.
79.
测定咖啡因代谢物评价 N-乙酰转移酶、CYP1A2和黄嘌呤氧化酶活性 总被引:8,自引:0,他引:8
目的是对中国人N-乙酰化酶(NAT2)、CYP1A2酶和黄嘌呤氧化酶(XO)的活性进行分析。120名健康志愿者饮用3杯咖啡后于4~5h留尿,用HPLC方法测定尿中5种咖啡因主要代谢物浓度,即5-乙酰胺基-6-甲酰胺基-3-甲基尿嘧啶(AFMU)、1-甲基黄嘌呤(1X)、1-甲基尿酸(1U)、1,7-二甲基尿酸(17X)、1,7-二甲基黄嘌呤(17U)。其中N-乙酰化酶活性用AFMU/1X或AFMU/(AFMU+1X+1U)表示;CYP1A2酶活性指标采用(AFMU+1X+1U)/17X或AFMU+1X+1U)/17U;XO酶活性指标采用1U/1X或1U/(1X+1U)。结果表明,N-乙酰化酶活性呈两态分布,慢代谢者占16.7%,CYP1A2和XO酶活性呈对数正态分布,其代谢比值与国外文献报道一致。提示通过测定咖啡因代谢物比值,可以进行NAT2酶、CYP1A2酶和黄嘌呤氧化酶活性分析。 相似文献
80.
Molecular phenotype of a human lymphoblastoid cell-line homoplasmic for the np 7445 deafness-associated mitochondrial mutation 总被引:7,自引:1,他引:6
We have studied mitochondrial gene expression and metabolic function in a
human lymphoblastoid cell-line homoplasmic for the np 7445, deafness-
associated mitochondrial DNA mutation. The mutation maps to the 3' termini
of the oppositely oriented genes encoding cytochrome oxidase subunit I
(COI) and tRNA-ser(UCN). In comparison with control lymphoblastoid cells,
we detected a marked depletion (> 60%) of tRNA- ser(UCN). There was,
however, no significant impairment of respiratory function, no alteration
to the structure or abundance of COI mRNA or its precursors, and no
detectable abnormality of mitochondrial protein synthesis. We also found
considerable tissue-variation in the abundance of tRNA-ser(UCN). We propose
that the tissue-specific phenotype associated with this mutation results
from an inherent deficiency in the processing of the mutant pre-tRNA, that
becomes limiting for protein synthesis only in a restricted set of cells of
the auditory system in which the tRNA is, for other reasons, already at a
critically low level.
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