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排序方式: 共有838条查询结果,搜索用时 15 毫秒
31.
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RD Rosenberg WC Hunt MR Williamson FD Gilliland PW Wiest CA Kelsey CR Key MN Linver 《Canadian Metallurgical Quarterly》1998,209(2):511-518
PURPOSE: To examine how common patient factors affect screening mammographic sensitivity and cancer stage at diagnosis. MATERIALS AND METHODS: The authors used a population-based database of 183,134 screening mammograms and a statewide tumor registry to identify 807 breast cancers detected at screening mammography. RESULTS: Sensitivity varied significantly with ethnicity, use of estrogen replacement therapy, mammographic breast density, and age. Sensitivity was 54% (13 of 24) in women younger than 40 years, 77% (121 of 157) in women aged 40-49 years, 78% (224 of 286) in women aged 50-64 years, and 81% (277 of 340) in women older than 64 years. Sensitivity was 68% (162 of 237) for dense breasts and 85% (302 of 356) for nondense breasts and 74% (180 of 244) in estrogen replacement therapy users and 81% (417 of 513) in nonusers. Sensitivity was most markedly reduced with the combination of dense breasts and estrogen replacement therapy use; there was little difference when only one factor was present. Median cancer size and the percentage of early cancers showed little change with any factors. CONCLUSION: Age is a minor determinant of mammographic sensitivity in women aged 40 years or older. Sensitivity is substantially decreased with the combination of higher breast density and estrogen replacement therapy use. There was not a notable shift in cancer outcomes in the groups with lower mammographic sensitivity. These data do not support different screening recommendations in women aged 40-49 years or in estrogen replacement therapy users. 相似文献
33.
AM Mansour K Kassak M Chaya T Hourani A Sibai MN Alameddine 《Canadian Metallurgical Quarterly》1997,81(10):905-906
Here we report a case that presented with sudden onset of neurological symptoms and was treated with ganciclovir. Polymerase chain reaction analysis for human herpes virus-6 (HHV-6) from his cerebrospinal fluid was later found to be positive. He subsequently recovered with minimal residual neurological symptoms. Encephalitis secondary to this virus may be more common than previously thought in patients undergoing bone marrow transplantation. This condition should be considered in the differential diagnosis of sudden onset neurological symptoms after bone marrow transplantation. 相似文献
34.
DJ MacGowan MN Janal WC Clark RN Wharton RM Lazar RL Sacco JP Mohr 《Canadian Metallurgical Quarterly》1997,49(1):120-125
BACKGROUND: Questionnaire-based surveys from several countries have consistently detected adverse health associated with home dampness and mould growth. METHODS: To test the validity of questions commonly used to indicate the presence of indoor mould, questionnaires were administered in 403 homes where dust samples were taken for viable fungi and air samples for ergosterol. RESULTS: Geometric mean concentrations of the total viable fungi were 255 (SE 116) x 10(3) CFU/g when mouldy odours were reported and 155 (SE 55) when odours were not reported (P = 0.01). Similarly, reported water damage was associated with a 50% increase (P = 0.06). Geometric mean concentrations of the predominantly indoor-source fungi, Aspergillus plus Penicillium, were twice as high when mould or mildew was reported than when not mentioned (P = 0.01). The presence of reported mould or water damage was unrelated to the presence of detectable levels of ergosterol. There was evidence for reporting bias: in the presence of low concentrations of viable fungi in dust, respondents reporting allergies were more likely to report visible mould growth (odds ratio [OR] = 1.8, 95% confidence interval [CI]: 0.9-3.5, P = 0.10. In the presence of elevated concentrations of dust fungi, respondents who smoked were less likely to report visible mould growth, (OR = 0.4, 95% CI: 0.2-0.7, P = 0.005). CONCLUSIONS: Reported mould, water damage, and mouldy odours were associated with elevated levels of indoor fungi. However, inaccuracy was high and there was evidence of a systematic reporting bias. Future research should concentrate on developing accurate objective measures of exposure to fungi, and then use this information to develop valid questionnaires. Currently, objective measures not questionnaires, are recommended to clarify the health effects of indoor fungi. 相似文献
35.
Sequence analysis of the Lymantria dispar multicapsid nucleopolyhedrovirus (LdMNPV) genome identified an open reading frame (ORF) encoding a 548-amino-acid (62-kDa) protein that showed 35% amino acid sequence identity with vaccinia virus ATP-dependent DNA ligase. Ligase homologs have not been reported from other baculoviruses. The ligase ORF was cloned and expressed as an N-terminal histidine-tagged fusion protein. Incubation of the purified protein with [alpha-32P]ATP resulted in formation of a covalent enzyme-adenylate intermediate which ran as a 62-kDa labeled band on a sodium dodecyl sulfate-polyacrylamide gel. Loss of the radiolabeled band occurred upon incubation of the intermediate with pyrophosphate, poly(dA) . poly(dT)12-18, or poly(rA) . poly(dT)12-18, characteristics of a DNA ligase II or III. The protein was able to ligate a double-stranded synthetic DNA substrate containing a single nick and inefficiently ligated a 1-nucleotide (nt) gap but did not ligate a 2-nt gap. It was able to ligate short, complementary overhangs but not blunt-ended double-stranded DNA. In a transient DNA replication assay employing six plasmids containing the LdMNPV homologs of the essential baculovirus replication genes, a plasmid containing the DNA ligase gene was neither essential nor stimulatory. All of these results are consistent with the activity of type III DNA ligases, which have been implicated in DNA repair and recombination. 相似文献
36.
V Thomé-Duret G Reach MN Gangnerau F Lemonnier JC Klein Y Zhang Y Hu GS Wilson 《Canadian Metallurgical Quarterly》1996,68(21):3822-3826
The development of a hypoglycemic alarm system using a subcutaneous glucose sensor implies that a decrease in blood glucose is rapidly followed by a decrease in the signal generated by the sensor. In a first set of experiments the linearity and the kinetics of the response of sensors implanted in the subcutaneous tissue of normal rats were investigated during a progressive increase in plasma glucose concentration: the sensitivities determined between 5 and 10 mM and between 10 and 15 mM were not significantly different, and a 5-10 min delay in the sensor's response was observed. In a second set of experiments, performed in diabetic rats, the kinetics of the decrease in subcutaneous glucose concentration following insulin administration was monitored during a decrease in plasma glucose level, from 15 to 3 mmol/L. During the 20 first min following insulin administration, the sensor monitored glucose concentration in subcutaneous tissue with no lag time. Subsequently, the decrease in the estimation of subcutaneous glucose concentration preceded that of plasma glucose. This phenomenon was not observed when the same sensors were investigated in vitro during a similar decrease in glucose concentration and may be due to a mechanism occurring in vivo, such as the effect of insulin on glucose transfer from the interstitial space to the cells surrounding the sensor. It reinforces the interest of the use of implantable glucose sensors as a part of a hypoglycemic alarm. 相似文献
37.
Iron deficiency can be caused not only by diets deficient in iron but by poor absorption of available dietary iron. Extrinsically tagging foods with radioiron allows the exact measurement of iron absorbed from heme and nonheme iron foods. It has furthered the study of the effect of enhancers and inhibitors of iron absorption. As a result, we have a greater understanding of why iron deficiency and iron deficiency anemia are prevalent in populations of low socioeconomic status and of which food vehicles and iron compounds are most suitable for iron fortification. 相似文献
38.
In the world of geospatial data infrastructures, geoportals are developed to facilitate access and use of geospatial resources,
including data. The design and implementation of effective and efficient geoportals are becoming crucial. Providing possibilities
for users to organize and integrate available resources can arguably enhance the process of data discovery and spatial analysis
required, and hence, is the focus of this paper. We argue that the synthesis of summaries of distributed datasets, map and
feature services through the geoportal can present a coherent view to support data discovery. For this purpose, the atlas
metaphor is used as an indexing server and integration interface of summaries. Thematic maps and a storyteller view are accessible
through the atlas metaphor. They can be used to provide a supporting context for data discovery and access purposes.
相似文献
Trias AdityaEmail: |
39.
40.
Electron microscope studies of the articular cartilages removed in the course of the operation on 6 patients with rheumatoid arthritis were carried out. The processes of destruction of chondrocytes and the cartilaginous matrix in different regions of the articular cartilage were traced. In the surface areas of the drastically changed cartilage there were observed leucocytes of the synovial fluid, and in deeper areas--disintegration of chondrocytes and extracellular disposition of lysosomes and altered organellas, destroyed cartilaginous cells. In these areas destruction of collagenous fibres was particularly intensive. In areas of the tissue remote from the destuction hypertrophy of chondrocytes due to hyperplasia of various organellas and the Golgi complex in particular were noted. In the Golgi zone granules of glycogen were detected. No mitoses were observed. Apparently, the enzymatic destruction of the cartilaginous matrix in rheumatoid arthritis could proceed at the expense of the activazation of the synovial fluid lysosomes and lysosomes of chondrocytes themselves. A reparative regeneration of the disintegrating matrix was realized mainly because of hypertrophy of the functionally preserved chondrocytes. 相似文献