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排序方式: 共有2716条查询结果,搜索用时 31 毫秒
991.
992.
E Bayever KM Haines PL Iversen RW Ruddon SJ Pirruccello CP Mountjoy MA Arneson LJ Smith 《Canadian Metallurgical Quarterly》1994,12(3-4):223-231
Cells were treated in vitro with oligodeoxyribonucleotide phosphorothioates (ODNs) complementary to sites common to both wild-type and mutant p53 nucleotide sequences. Acute myelogenous leukemia (AML) blasts from peripheral blood were exposed to four different p53 ODNs and showed anti-leukemic effects in suspension culture. This effect continued after removal of the ODN from the medium. Blocking of self-renewal of the leukemic blast stem cells in secondary plating of cells from cloning assays by two of the p53 ODNs was also observed. Control ODNs had no effect on leukemic blasts. Treatment of normal bone marrow cells with the four p53 ODNs did not influence their growth, nor was there any effect by the p53 ODNs on the leukemic cell-line, HL60, that does not express p53. These data suggest that p53 ODNs are selectively toxic to primary myelogenous blasts and may be therapeutically useful in AML. 相似文献
993.
SL Hart AM Knight RP Harbottle A Mistry HD Hunger DF Cutler R Williamson C Coutelle 《Canadian Metallurgical Quarterly》1994,269(17):12468-12474
Ligands that bind mammalian cell surface integrins with high affinity can mediate cellular internalization. We show that particles of the bacteriophage fd that display the cyclic integrin-binding peptide sequence GGCRGDMFGC in a proportion of their major coat protein subunits bind to cells and are efficiently internalized. In the displayed peptide the conformation of the RGD motif is restricted within a hairpin loop formed by a disulfide bridge between the 2 cysteine residues. Cellular internalization of phage was demonstrated by confocal and non-confocal immunofluorescence microscopy of tissue-cultured cells incubated with phage particles. The phage were contained in juxtanuclear vesicles in the same serial sections as transferrin receptor but were not colocalized with the cell surface marker alkaline phosphatase. Cell binding and internalization was inhibited by preincubation of cells with the integrin-binding peptide GRGDSP, whereas the control peptide GRGESP had no inhibitory effect. These results indicate that cyclic integrin-binding peptides can be used to target and enter cells and that it should be possible to exploit such peptides for the introduction of DNA, drugs, or other macromolecules. 相似文献
994.
V Narayana PL Roberson AT Pu H Sandler RH Winfield PW McLaughlin 《Canadian Metallurgical Quarterly》1997,37(5):1181-1185
PURPOSE: Both ultrasound (US) and computerized tomography (CT) images have been used in the planning of prostate interstitial therapy. Ultrasound images more clearly define the apex and capsule of the prostate, while CT images define seed positions for postimplant dosimetry. Proper registration of the US volume with the CT volume is critical to the assessment of dosimetry. We therefore compared US and CT prostate volumes to determine if differences were significant. METHODS AND MATERIALS: Ten consecutive patients entered in an interstitial implant program were studied by pretreatment US. In addition, pretreatment CT scans were obtained and three physicians independently outlined the dimensions of the prostate on these images. The patients subsequently underwent placement of radioactive 125I or 103Pd. Postimplant CT images were obtained the next day and the postimplant prostate volumes were outlined by the same three physicians. Seven of 10 patients underwent late CT scans 9-14 months postimplant for comparison of preimplant and immediate postimplant CT studies. RESULTS: There were differences between US and CT volumes. Although the physician-to-physician variation was significant, the trends were consistent, with US prostate volume typically smaller (47%) than the preimplant CT volume and markedly smaller (120%) than the postimplant CT volume. Prostate volumes derived from late CT images did not consistently return to preimplant levels. CONCLUSIONS: Significant differences in volume of the prostate structure were found between US and CT images. The data suggests that: (a) Implants planned on CT tend to overestimate the size of the prostate and may lead to unnecessary implantation of the urogenital diaphragm and penile urethra. (b) Registration of initial US and postimplant CT prostate volumes required for accurate dosimetry is difficult due to the increased volume of prostate secondary to trauma. (c) Further study to determine the optimal time for the postimplant CT is necessary. 相似文献
995.
John Knight Jason W. Holland Linda A. Bowden Katrina Halliday Andrew F. Rowley 《Lipids》1995,30(5):451-458
The eicosanoid generating potential of the brain, gills, skin, ovary, muscle, eye, liver, spleen, heart, and alimentary canal
in the rainbow trout,Oncorhynchus mykiss, was examined. All the organs/tissues examined synthesized the 12-lipoxygenase products, 12-hydroxyeicosatetraenoic acid
(12-HETE), and 12-hydroxyeicosapentaenoic acid (12-HEPE), implying the widespread nature of this enzyme in trout. Both prostaglandin
E and LTC were also found in variable amounts in the organs, with the greatest amount of PGE found in the gill. Leukotriene
(LT) B4 and LTB5 were found in supernatants from calcium ionophore-challenged brain, skin, ovary, liver, spleen, and heart, but the lipoxins
A4 and A5 were only present in brain, ovary, and spleen in relatively small amounts. As lipoxins have previously been shown to be synthesized
by macrophages in rainbow trout [Pettittet al., J. Biol. Chem. 266, 8720–8726 (1991)], and related cells (microglial cells) are found in the brain of mammals, the localization of macrophage-like
cells in trout brain was investigated immunocytochemically. Monoclonal antibodies specific for trout leucocytes failed to
identifity any microglial-like cells in sections of the brain, although microvessels containing immuno-positive reaction products
were observed. A number of distinct lipoxygenase products were found in supernatants of ionophore-challenged gill, including
14-hydroxydocosahexaenoic acid, 12-HETE, and 12-HEPE, and a large number of dihydroxy fatty acid derivatives with conjugated
triene chromophores. One of these products was tentatively identified as 8(R),15(S)-dihydroxyeicosatetraenoic acid, a dual 12- and 15-lipoxygenase product, but apparently no LTB4 was generated by this tissue. 相似文献
996.
In order to determine if functional changes in N-methyl-D-aspartate receptors and GABAA receptors play a role in the remarkable anoxia tolerance of freshwater turtle brain, we used autoradiographic techniques to assay [3H]MK-801 and [3H]flunitrazepam binding in turtle forebrain after turtles had been subjected to anoxia for 2 or 6 h. The effects of glutamate, glycine, competitive N-methyl-D-aspartate antagonists, glycine antagonists, polyamines, magnesium, and zinc on [3H]MK-801 binding were the same in anoxic and control turtle forebrains. These results indicate that NMDA receptor regulation plays no role in the adaptive responses to anoxia in turtle brain. In contrast, [3H]flunitrazepam binding was significantly increased in the anoxic dorsal cortex and striatum. The most parsimonious explanation for elevated benzodiazepine receptor binding is that the rise in extracellular GABA levels known to accompany anoxia enhances benzodiazepine receptor affinity. It is possible, however, that GABAA receptor upregulation during anoxia increases the effectiveness of the inhibitory action of released GABA and contributes to the anoxia tolerance of turtles. 相似文献
997.
H Kalasz T Watanabe H Yabana K Itagaki K Naito H Nakayama A Schwartz PL Vaghy 《Canadian Metallurgical Quarterly》1993,331(1-2):177-181
Damage to the spinal cord in course of the treatment of diseases of the infrarenal aorta is a rare but calamitous complication. The reported incidence is about 0.2%. The neurological loss is usually complete flaccid paraplegia with high mortality and rare full or partial recovery. Between 1980 and 1991, 1070 reconstructive procedures of the infrarenal aorta were performed: 821 due to aneurysm (316 elective procedures [mortality 1.6%] and 505 emergency procedures [mortality 24.5%]) and 249 due to aorto-iliac occlusive disease. Damage to the spinal cord occurred in 2 patients (2/1070, 0.19%). One patient had incomplete paraparesis following repair of an unruptured abdominal aortic aneurysm with gradual return of all neurological symptoms to normal. The second patient developed complete paraplegia following repair of a ruptured infrarenal aneurysm. There war no recovery of the symptoms. The patient died from septicaemia 4 months later. 相似文献
998.
999.
1000.
PL Antignani S Pillon F Grassi ML Paiella M Bartolo 《Canadian Metallurgical Quarterly》1993,44(7):523-526
The authors examined 47 subjects affected by acute phlebothrombosis of the lower limbs by means of light-reflection-rheography (LRR). The diagnosis was based on the results of clinical, Doppler, and duplex scanner evaluations. The results were compared with those obtained in 30 healthy subjects (control group). The LRR examinations were performed by two methods: the one consisting of a passive execution of postural movements of the limb, the other using the technique of plethysmographic venous occlusion. The pathological LRR curves were characteristic for each type of disease and for the site of thrombosis and were different from the normal ones. The results obtained show the usefulness of the method and it potential in studying the collateral circulation and the effects of different therapies. 相似文献