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排序方式: 共有341条查询结果,搜索用时 15 毫秒
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32.
Patient‐ and family‐centred care in the intensive care unit: a challenge in the daily practice of healthcare professionals 下载免费PDF全文
33.
目的:构建神经原相关的细胞粘附分子(NrCAM)和免疫球蛋白Fc片段融合基因的重组质粒并通过Baculovirus载体转染到昆虫细胞。方法:利用RT-PCR方法从神经母细胞瘤细胞系SK-N-SN获得NrCAM的信号肽区和跨膜区片段并直接克隆到pGEMT载体,经多次酶切、连接、转化、筛选获得NrCAM-Fc的重组副合基因,测序后将此基因通过Baculovirus载体转染至昆虫细胞。结果:多种酶切和测序结果表明NrCAM-Fc的序列与原序列符合率达98%以上,NrCAM与Fc连接处序列保证了Fc的读码框架(ORF)。结论:Baculovirus载体转染效率高,检测方法简便易行。 相似文献
34.
Quality adjusted life years (QALYs) are well recognized as a valid measure for outcomes in cost-effectiveness analyses. However, it is difficult to obtain a summary utility score from health status measure such as the SF-36.
OBJECTIVE: To predict a summary utility score (represented by HUI) from the scores on the SF-36.
METHODS: A structural equation framework was applied to data collected from 1992 to 1995 on the Southern California Kaiser Permanente population (n = 5,794). An instrumental variable (IV) method mitigated the endogeneity in estimating the HUI(MarkII). Socioeconomic and disease variables were used as covariates. A split-sample analysis provided cross-validation.
RESULT: This model predicted 33.68% of the observed variance in HUI index scores with an adjusted R2 of 0.3335. Observed HUI index scores were distributed with a mean of 0.7963 and std. deviation of 0.1796. Parameter estimates of most of the SF-36 components (except General Health & Social Functioning) showed statistical significance at α= 0.05 level. People with high chronic disease scores were found to have low SF-36 scores, and parameter estimates of this covariate were also found statistically significant at α= 0.05 level in all structural equations. However, all the socioeconomic variables showed statistical insignificance. Comparison of "Forecasting" and "Estimation" sub-samples showed satisfactory results during cross-validation.
CONCLUSION: Result of this study provides a quantitative link between two important measures of health status. The present model can be used to estimate overall health utility summary scores from previous studies using the SF-36. 相似文献
OBJECTIVE: To predict a summary utility score (represented by HUI) from the scores on the SF-36.
METHODS: A structural equation framework was applied to data collected from 1992 to 1995 on the Southern California Kaiser Permanente population (n = 5,794). An instrumental variable (IV) method mitigated the endogeneity in estimating the HUI(MarkII). Socioeconomic and disease variables were used as covariates. A split-sample analysis provided cross-validation.
RESULT: This model predicted 33.68% of the observed variance in HUI index scores with an adjusted R
CONCLUSION: Result of this study provides a quantitative link between two important measures of health status. The present model can be used to estimate overall health utility summary scores from previous studies using the SF-36. 相似文献
35.
John Lubega 《International Journal of Clinical & Laboratory Research》1990,20(3):203-208
Summary Purified placental syncytiotrophoblastic membrane has been used in a radioreceptor assay to study the binding of tritium radiolabeled
human thrombin. Binding was found to be saturable at higher membrane concentrations when using a fixed amount of ligand and
showed a hyperbola analogous to enzyme-substrate binding. A Scatchard plot was linear and revealed homogeneous binding sites
with a high-affinity constant Ka=3×1010 M−1 and capacity of 3.05×1011 sites/mg of membrane protein. This high-affinity compares well with chick and embryo cell thrombin receptor which has homogeneous
sites and high-affinity in contrast to platelet thrombin receptor which exhibits multiple binding sites and cooperative effects
as previously noted. A thrombin receptor on the placenta might serve to mobilize thrombin into placental tissue leading to
conversion of fibrinogen into fibrin, fibrinoid necrosis being so common in certain placentae. A receptor-mediated transplacental
passage of thrombin into the fetal circulation is also proposed. 相似文献
36.
Serum resistance associated (SRA) gene has been found to confer resistance to the innate trypanolytic factor (TLF) found in normal human serum; thus allowing Trypanosoma brucei brucei to survive exposure to normal human serum. This study was carried out to examine the presence of SRA gene and identify the origin of T. b. rhodesiense isolates from three districts in Tanzania, namely Kibondo, Kasulu and Urambo. Twenty-six T. b. rhodesiense isolates and two references T. b. rhodesiense isolates from Kenya were examined for SRA gene using simple Polymerase Chain Reaction technique. The gene was found to be present in all 26 T. b. rhodesiense isolates including the two references isolates from Kenya. The SRA gene was confirmed to be specific to T. b. rhodesiense since it could not be amplified from all other Trypanozoon including T. b. gambiense; and gave an amplified fragment of the expected size (3.9kb), confirming that all these isolates were T. b. rhodesiense of the northern variant. Although the geographic distributions of T. b. gambiense and T. b. rhodesiense are clearly localized to west/central Africa and eastern Africa, respectively, natural movement of people and recent influx of large number of refugees into Tanzania from the Democratic Republic of Congo, could have brought T. b. gambiense in western Tanzania. The overlap in distribution of both of these pathogenic sub-species could result in erroneous diagnoses since both trypanosome sub-species are morphologically identical, and currently serologic methods have low specificity. Both the susceptible and resistant T. b. rhodesiense isolates possessed the SRA gene suggesting that there is no correlation between drug resistance and presence of SRA gene. The use of SRA gene helps to confirm the identity and diversity of some of the isolates resistant to various drugs. 相似文献
37.
Reversible oxidant-induced increases in albumin transfer across cultured endothelium: alterations in cell shape and calcium homeostasis 总被引:20,自引:0,他引:20
To determine whether reactive oxygen molecules could directly and reversibly increase the transfer of albumin across an endothelial barrier, we measured albumin transfer across monolayers of endothelium cultured on micropore filters before and after exposure to xanthine and xanthine oxidase. Xanthine and xanthine oxidase increased endothelial albumin transfer in a dose-dependent fashion. Parallel phase contrast and fluorescence microscopy demonstrated retraction of adjacent cells from one another and disruption of the actin filaments. The oxidant- induced increases in albumin transfer and changes in cell shape were reversed by removing xanthine oxidase and then incubating the monolayers for 3 1/2 hours in tissue culture media enriched with fetal bovine serum. However, incubation in tissue culture media without serum resulted in progressive injury and cell death. Hence, the brief exposure to oxidants initiated a progressive injury process that was reversed by incubation in serum. Because intracellular and extracellular calcium are important determinants of cell shape, and because some oxidized membrane lipids act as calcium ionophores, we asked whether oxidants altered endothelial calcium homeostasis. Xanthine-xanthine oxidase increased release of 45Ca++ from preloaded cells. The calcium antagonist lanthanum chloride prevented xanthine- xanthine oxidase increases in endothelial albumin transfer and prevented the changes in cell shape; chelation of extracellular calcium inhibited lysis of endothelium by xanthine-xanthine oxidase; and the calcium ionophore A23187 increased endothelial albumin transfer and mimicked the oxidant-induced changes in cell shape. Lanthanum chloride inhibited these effects of A23187. These data suggest that oxygen radicals can reversibly increase endothelial permeability to macromolecules, that this is associated with reversible changes in endothelial cell shape and actin filaments, and that the changes in cell shape are related to oxidant-induced changes in endothelial calcium homeostasis. 相似文献
38.
39.
Structural abnormalities of the X chromosome are rarely found in neoplastic disorders. We describe three patients with a history of idiopathic acquired sideroblastic anemia (IASA); each one had an abnormal clone of cells in the bone marrow, characterized by a structurally abnormal X chromosome. In two of these patients, the predominant karyotype was 47,X,2idic(X)(q13); in the other patient, it was 46,X,t(X;11)(q13;p15). Inasmuch as all three of these cases involved chromosome band Xq13, as did two previously published cases, we suggest that band Xq13 may be more prone to structural rearrangement than other X chromosome bands in hematologic disorders. The common Xq13 chromosome breakpoint and clinical presentation (IASA) among these three patients and the occurrence of an X-linked type of sideroblastic anemia may suggest that an association exists between X chromosome abnormalities and IASA. Perhaps alteration of a gene or chromosome structure in or near band Xq13 predisposes to development of IASA. The fact that two of these patients had preleukemia and the third had overt acute leukemia may imply that patients with IASA and X chromosome abnormalities have a poor prognosis. Cases of IASA without associated X chromosome abnormalities are known; thus, if an association between IASA and an abnormal X chromosome does exist, most likely it involves only some patients with IASA. 相似文献
40.
Plasticity of representational maps in adult cerebral cortex has been
documented in both sensory and motor cortex, but the anatomical basis for
cortical plasticity remains poorly understood. To investigate horizontal
connectivity in primary motor cortex (M1) as a putative anatomical
substrate for short-term, functional plasticity of adult motor cortical
representations, a combination of electrical stimulation and biocytin
labeling was used to examine pre-existing patterns of intrinsic connections
in adult rat M1 in relationship to the pattern of reorganization of the
motor movement may induced by transection of the contralateral facial
nerve. Two hours after nerve cut, small, circumscribed regions of the
forelimb representation expanded medially into territory previously devoted
to the vibrissae representation. Outside of this novel, expanded forelimb
region, no forelimb movement could be evoked from the former vibrissae
representation at any time over the period of hours tested, thus
representing silent cortex. Injections placed into vibrissae cortex
representing the newly expanded forelimb representation gave rise to
labeled axons and dense terminal fiber labeling which crossed the
forelimb/vibrissae border and extended up to 1.2 mm within the
low-threshold forelimb representation. In contrast, injections placed into
silent vibrissae cortex gave rise to labeled axons and terminal boutons
which remained mostly restricted to the original vibrissae representation,
with only sparse projections that crossed into the low-threshold forelimb
representation. Thus, these results suggest that the extent of short-term,
functional reorganization of M1 induced within the first several hours
following peripheral nerve cut is mediated, and constrained, by an
anatomical framework of pre-existing, horizontal projections which traverse
representation borders.
相似文献