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排序方式: 共有386条查询结果,搜索用时 15 毫秒
71.
Anterior temporal lobes and hippocampal formations: normative volumetric measurements from MR images in young adults 总被引:25,自引:0,他引:25
Jack CR Jr; Twomey CK; Zinsmeister AR; Sharbrough FW; Petersen RC; Cascino GD 《Radiology》1989,172(2):549-554
Volumes of the right and left anterior temporal lobes and hippocampal formations were measured from magnetic resonance images in 52 healthy volunteers, aged 20-40 years. Subjects were selected by age, sex, and handedness to evaluate possible effect of these variables. Data were normalized for variation in total intracranial volume between individuals. Right-left asymmetry in the volumes of the anterior temporal lobes and hippocampal formations was a normal finding. The anterior temporal lobe of the non-dominant (right) hemisphere was larger than the left by a small (mean right-left difference, 2.3 cm3) but statistically significant amount (P less than .005) in right-handed subjects. No significant effect of age or sex was seen in normalized right or left anterior temporal lobe volume. The right hippocampal formation was larger than the left for all subjects by a small (mean right-left difference, 0.3 cm3) but statistically significant amount (P less than .001). No effect of age, sex, or handedness was seen in normalized hippocampal formation volumes. 相似文献
72.
Expression and functionality of the trkA proto-oncogene product/NGF receptor in undifferentiated hematopoietic cells 总被引:3,自引:0,他引:3
Chevalier S; Praloran V; Smith C; MacGrogan D; Ip NY; Yancopoulos GD; Brachet P; Pouplard A; Gascan H 《Blood》1994,83(6):1479-1485
The expression of the low-affinity NGF receptor (p75) and the trkA proto-oncogene product was analyzed in a series of human hematopoietic cell lines at protein and RNA levels. We did not detect any form of NGF receptor in cell lines displaying a myelomonocytic phenotype (HL60 and U937). In contrast, cells displaying a more immature erythroleukemic phenotype (TF1 and K562) expressed TrkA in the absence of detectable p75. Scatchard analysis showed a single high-affinity site for NGF (kd = 10(-10) mol/L), with a copy number ranging from 300 to 3,000 sites per cell depending on the studied cell line. In addition, NGF induced autophosphorylation of TrkA and could substitute for granulocyte- monocyte colony-stimulating factor to trigger the proliferation of the TF1 cell line, with a half-maximal signal observed at 50 pmol/L, indicating that p75 is not required for DNA synthesis in this cell line. The physiologic relevance of NGF in early hematopoiesis was confirmed by showing that 12% to 15% of progenitor blood cells from mice treated with 5-fluorouracil expressed TrkA and that these cells could be induced to proliferate and differentiate in response to NGF in association with macrophage colony-stimulating factor. Our study demonstrates for the first time that trkA proto-oncogene expression and activation is not restricted to the nervous system, but is also an important element in early hematopoiesis. 相似文献
73.
74.
力竭性运动对大鼠血浆心钠素及心肌血供的影响 总被引:1,自引:0,他引:1
目的:观察不同训练程度大鼠力竭性运动后血浆心钠素含量及心肌缺血情况,探讨力竭性运动对大鼠心脏内分泌以及心肌血供的影响。方法:实验于2006—10/12在武汉体育学院细胞与分子生物学实验室完成。选择SD大鼠16只,按随机数字表法分为3组,安静对照组(n=4)笼内生活,自由饮食;游泳力竭组(n=6)适应性喂养1周后进行一定的适应性游泳训练;长期耐力训练游泳力竭组(n=6)训练8周,6次/周。8周后,后两组大鼠进行力竭性运动,运动后取大鼠血浆,采用放射免疫法测定心钠素含量;取心肌组织,制作光镜切片,采用Nagar-Olsen特殊染色法检测心肌缺血情况。结果:16只大鼠全部进入结果分析。①在经过8周的运动训练后,游泳力竭组、长期耐力训练游泳力竭组大鼠血浆心钠素含量显著高于安静对照组(P〈0.05,〈0.01);长期耐力训练游泳力竭组大鼠血浆心钠素含量显著高于游泳力竭组(P〈0.05)。②游泳力竭组大鼠心肌组织缺血较为严重;而长期耐力训练游泳力竭组大鼠心肌组织与安静对照组相比,也有缺血现象发生,但没有游泳力竭组严重。结论:力竭性运动会造成大鼠心血管内分泌活性物质心钠素的失调,并造成心肌组织缺血;长期耐力游泳训练可以使大鼠心脏结构及功能产生一定的适应性改变。 相似文献
75.
Goss GD; Wittwer MA; Bezwoda WR; Herman J; Rabson A; Seymour L; Derman DP; Mendelow B 《Blood》1985,66(5):1043-1046
Bone marrow transplantation for severe idiopathic aplastic anemia was undertaken in a patient, using his monozygotic twin brother as the donor. In spite of the use of syngeneic bone marrow, failure of engraftment occurred on two occasions. In vitro studies demonstrated that natural killer (NK) cells from the recipient markedly inhibited the growth of donor bone marrow granulocyte progenitor cells. On a third attempt, successful bone marrow engraftment was achieved following high-dose cyclophosphamide, which has previously been shown to be inhibitory to NK cells. We conclude that NK cell activity may play an important role in bone marrow failure as well as being responsible for at least some cases of aplastic anemia. 相似文献
76.
Plasminogen activator inhibitor: a regulator of ancrod-induced fibrin deposition in rabbits 总被引:2,自引:0,他引:2
Plasma levels of a fast-acting plasminogen activator inhibitor (PAI), which neutralizes both tissue plasminogen activator (t-PA) and urokinase, are markedly increased in endotoxin-treated rabbits. The ability of this inhibitor to prevent the fibrinolysis that occurs after a thrombogenic stimulus was investigated in a rabbit model. Normal and endotoxin-treated male New Zealand rabbits were infused with ancrod, an enzyme that causes noncrosslinked fibrin formation in vivo. Ancrod stimulated t-PA activity by 90% in normal rabbits and caused hypofibrinogenemia but did not increase PAI levels or induce fibrin deposition in target organs. Rabbits injected with endotoxin (10 micrograms/kg) showed an increase in PAI from less than 1 to 32 U/mL 4 hours later. When ancrod was infused at this time, 90% of the rabbits developed renal fibrin thrombi. Fibrin deposition was recorded in 40% of the rabbits that received a lower dose of endotoxin (1.0 microgram/kg) and had a PAI level of 14 U/ml at the time of ancrod infusion 4 hours later. Fibrin deposition did not occur in the endotoxin-treated rabbits that received normal saline. These data suggest that high levels of PAI inhibit fibrinolysis in vivo, thereby promoting fibrin clot deposition following a thrombogenic stimulus. 相似文献
77.
Cogan's syndrome with Takayasu's arteritis 总被引:1,自引:1,他引:1
Cogan's syndrome may be associated with large-vessel arteritis. We describe
a patient with ocular inflammation, sensorineural hearing loss and arm
claudication in whom a diagnosis of 'atypical' Cogan's syndrome and
Takayasu's arteritis was made. All symptoms resolved with treatment.
相似文献
78.
Ehrlich GD; Glaser JB; LaVigne K; Quan D; Mildvan D; Sninsky JJ; Kwok S; Papsidero L; Poiesz BJ 《Blood》1989,74(5):1658-1664
The extent of human T-cell leukemia/lymphoma virus type II (HTLV-II) infection and its rate of spread have been difficult to determine owing to the serological cross-reactivity between HTLV-I and HTLV-II. The present study overcame this problem by directly detecting type-specific proviral sequences by means of the polymerase chain reaction (PCR) and liquid hybridization. Screening was performed on a cohort of primarily white intravenous drug abusers (IVDAs), and individuals of other behaviorally defined risk groups from the New York City area. Eleven percent (19 of 169) of the individuals in these high-risk groups were determined by PCR to have HTLV-II proviral infections. One of these patients displayed an exfoliative erythrodermatitis. Thirteen of the 19 subjects were positive in an HTLV-II enzyme-linked immunosorbent assay (ELISA). The remaining six individuals, although negative in the HTLV- II ELISA, were confirmed as HTLV-II positive by analyzing their DNA with a second HTLV-II-specific primer detector system. Four additional individuals were reactive in the HTLV-II ELISA but were PCR-negative for HTLV-II. PCR analysis for HTLV-I revealed that all four were positive for that virus. Thirty-seven percent (seven of 19) of the HTLV- II PCR-positive subjects were also PCR-positive for HTLV-I, and 84% (16 of 19) of the HTLV-II positive individuals were infected with human immunodeficiency virus (HIV-1). Six individuals were triply infected with HTLV-I, HTLV-II, and HIV-1. 相似文献
79.
The Philadelphia (Ph1) chromosome, characteristic of chronic myelogenous leukemia (CML), arises from a reciprocal translocation between chromosomes 9 and 22. The site of the breakpoint on chromosome 22 is within a small region called the breakpoint cluster region (bcr). We have mapped the breakpoint within the bcr in peripheral blood leukocyte DNA from 22 Ph1-positive CML patients. No correlation between the site of the breakpoint and the clinical phase of the disease was found. However, a striking correlation between the site of the breakpoint and the length of time between presentation and onset of acute phase was observed: on average, patients with a 5' break-point had a fourfold longer chronic phase (median, 203 weeks) than those with a 3' breakpoint (median, 52 weeks). 相似文献
80.