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Transformation of plant tissues into crown gall tumors has been associated with the transfer of a portion of a tumor-inducing plasmid (Ti-plasmid) into plant DNA. Various laboratories have regenerated normal-appearing plants from a number of crown gall tumors. This study investigates the fate of the foreign DNA in a series of tissues derived from various parts of a plant regenerated from the tumor BT-37 by Braum and his coworkers. It was found that all the foreign DNA sequences were lost from tissues that had lost all their tumorous traits; whereas the plasmid DNA sequences were still present in tissues that appeared normal but still exhibited tumorous traits when returned to tissue culture media. From these studies it would appear that the presence of the Ti-plasmid sequences in the plant DNA is required for the maintenance of the transformed state. 相似文献
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C Derouesné 《Canadian Metallurgical Quarterly》1994,44(11):1432-1435
Frequency of memory complaints increases with age. Such complaints can be the presenting symptom of Alzheimer's disease. Most cases, however, are not related to Alzheimer's disease. They are included in the constructs of benign senescent forgetfulness or age-associated memory impairment. In the later, memory complaints are considered as the subjective counterpart of the age-associated decline in memory test performance. Actually, memory complaints are associated with various factors: perceptual disorders, general health, functional disability, affective disturbances, psychosocial changes... The first step in the management of memory complaints is to rule out Alzheimer's disease and affective disturbances which could require specific therapeutic measures. Most often, memory complaints are the only presenting symptom: the signification of complaints should be analysed in each individual considering all the possibly causal factors in order to elaborate the appropriate management. 相似文献
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WK Estes 《Canadian Metallurgical Quarterly》1997,104(1):148-169
The author proposes that many forms of memory distortion, including the progressive changes in recollection of a learning experience often observed over successive tests, are due to the same processes that yield veridical recollection in some circumstances and memory loss and recovery in others. In a framework for interpreting all of these aspects of memory, the author assumes that the objects and events of a learning experience are encoded in parallel in traces of their perceptual attributes, which are basic to recognition, and in traces of reactions made to the events during or following learning, which are basic to recall. Random perturbation of remembered attribute values in both types of traces over retention intervals is a pervasive cause of both loss and distortions of memory. 相似文献
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We describe here a unique case of congenital adrenal hyperplasia (CAH) accompanied by Klinefelter syndrome. A Japanese boy was diagnosed as having CAH caused by 21-hydroxylase deficiency at birth, but was untreated thereafter until age 10. In the meantime he showed marked acceleration in somatic growth with sexual precocity by age 9, at which time growth completely stopped. During regular follow-ups at our clinic and steroid treatment after age 10, he was recognized as having bilateral small and firm testes. A chromosomal examination and a testicular biopsy revealed a complication of 47, XXY Klinefelter syndrome with CAH. Association of these two diseases has not been reported so far, and the present case is the first one to our knowledge. 相似文献
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A strategy for Compton scatter correction in brain SPECT images was proposed recently. It assumes that two radioisotopes are used and that a significant portion of photons of one radioisotope (for example, Tc99m) spills over into the low energy acquisition window of the other radioisotope (for example, Tl201). We are extending this approach to cases of several radioisotopes with mutual, multiple and significant photon spillover. In the example above, one may correct not only the Tl201 image but also the Tc99m image corrupted by the Compton scatter originating from the small component of high energy Tl201 photons. The proposed extension is applicable to other anatomical domains (cardiac imaging). 相似文献
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The purpose of this study are to construct the College Life Anxiety Scale for measuring the level of college students' anxiety and to examine its reliability and validity. After collecting items about the anxiety in college life, factor analysis was performed on the data obtained from 2,782 college students. The result, firstly, showed that the College Life Anxiety Scale consisting of 30 items had three factors, which were daily life anxiety, test anxiety and college maladjustment. Secondly, it was indicated that the Scale had both high test-retest reliability and internal consistency (.82 and .84, respectively). It was also suggested that the Scale had high content, clinical, and criterion-related validities. In conclusion, the College Life Anxiety Scale is well able to measure the level of college students' anxiety in their usual life. 相似文献
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Three groups of people ranging in age from 64 to 88 years performed tasks of word generation, paired-associate recall, also free and cued recall. The groups differed in socioeconomic status, verbal intelligence, and apparent levels of daily activity. A fourth group, consisting of young undergraduates, was also tested. Results showed that whereas there were age-related differences in some tests, these age differences were strongly modulated by characteristics of the participants and characteristics of the tasks. The findings are discussed in a contextualist framework. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
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Conducted 3 experiments with 83 male Long-Evans rats to investigate (a) the memory of hippocampus-damaged Ss, and (b) their ability to modify response strategies in relation to the influence of familiar contextual cues. In Exp I, groups of hippocampal and control Ss learned a simultaneous discrimination habit and were subsequently tested for its retention under variable contextual conditions. All groups recalled the discrimination response to an equally high level when testing conditions were constant throughout, but the hippocampal group showed impaired memory when contextual stimuli at recall testing did not conform to those of original learning. Results of Exp II indicate that the hippocampal impairment was not simply the result of introducing novel stimuli. In Exp III, Ss were administered a reversal learning task with contextual stimuli varied between the 2 tests. The typically observed impairment of hippocampal Ss on this task was reduced by contrasting contextual conditions. Results are seen to support a context-retrieval interpretation of hippocampal function. (26 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
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Compared the performance of 20 sleep-deprived undergraduates on a probe-recognition memory task with that of 20 nondeprived controls over periods up to 55 hrs. Recognition was either immediate or delayed by 20 sec. Results show that the sleep-deprived group made significantly more errors in the perception of the material, and under the delay condition retained less adequately those items correctly perceived. It is argued that these findings are consistent with the notion that sleep loss causes a deficit in attention, leading to misperception and a failure to rehearse adequately material presented for memorization. (French summary) (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
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When fibrous dysplasia affects the temporal bone, it most often presents with conductive hearing loss attributable to stenosis of the external auditory canal. Sensorineural hearing loss has usually been attributed to involvement of the otic capsule. We present a patient with bilateral fibrous dysplasia of the temporal bones who complained of unilateral hearing loss, facial tingling, and facial twitching. The audiogram showed severe sensorineural hearing loss. The hearing markedly improved and facial twitching and tingling ceased after decompression of the internal auditory canal via a middle fossa approach. This is the only case of which we are aware showing reversal of sensorineural hearing loss caused by fibrous dysplasia. 相似文献
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JD Adachi MJ Bell WG Bensen F Bianchi A Cividino RJ Sebaldt M Gordon G Ioannidis C Goldsmith 《Canadian Metallurgical Quarterly》1997,24(12):2308-2313
OBJECTIVE: To determine the efficacy of sodium fluoride (40 mg/day) in preventing rheumatoid arthritis (RA) induced bone loss, which may lead to osteoporosis. METHODS: We conducted an 18 month, randomized, double blind, placebo controlled trial in 38 patients with RA. The primary outcome measure was the difference in the percentage change between groups in lumbar spine bone mineral density (BMD) from baseline values after 18 months of therapy. The secondary outcome measures were the differences in the percentage change between groups in femoral neck, Ward's triangle, trochanter, and total body BMD from baseline after 18 months of therapy. RESULTS: There was a significant percentage difference (SD) between groups of 6.2% (7.3%) (p = 0.0005) in lumbar spine BMD after 18 months of treatment in favor of the fluoride group. The fluoride group experienced a 5.2% (8.4%) (p = 0.0125) increase, whereas the placebo group showed a 1.0% (4.8%) (p = 0.8015) decrease in lumbar spine BMD after treatment. No significant differences were found for the femoral neck, Ward's triangle, trochanter, and total body BMD in terms of the percentage changes from baseline within each treatment group or in the differences in the degree of change between groups after therapy. Lumbar spine BMD increased in about 80% of patients treated with fluoride (responders) compared to 44% of patients treated with placebo. CONCLUSION: The results showed that fluoride therapy was well tolerated and increased vertebral bone mass in patients with RA. 相似文献
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This position paper discusses how the tenets of Whole Language and Deaf Bilingual-Bicultural Education complement each other. It stresses that Whole Language is based on natural processes through which children can translate their constructs of personal experiences, observations, and perspectives into modes of communication that include written language and, in the present case, American Sign Language. The paper is based on two emphases: (a) Whole Language emphasizes a two-way teaching/learning process, teachers learning from children, and vice versa; and (b) Deaf Bilingual-Bicultural Education emphasizes American Sign Language as a language of instruction and builds on mutual respect for the similarities and differences in the sociocultural and socioeducational experiences and values of Deaf and hearing people. Both Whole Language and Deaf Bilingual-Bicultural Education attempt to authenticate curriculum by integrating Deaf persons' worldviews as part of educational experience. 相似文献
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F Randow WD D?cke DS Bundschuh T Hartung A Wendel HD Volk 《Canadian Metallurgical Quarterly》1997,158(6):2911-2918
LPS tolerance is characterized by a diminished monocytic synthesis of TNF-alpha and, interestingly, IL-10 after LPS restimulation. We wondered whether granulocyte-macrophage colony-stimulating factor (GM-CSF), IL-12, and IFN-gamma can prevent or reverse this down-regulation of TNF-alpha and IL-10 production. The LPS-induced TNF-alpha amounts in desensitized PBMC treated with GM-CSF, IFN-gamma, or IL-12 and in naive, non-cytokine-primed cultures were similar, while much more TNF-alpha was induced in cytokine-primed naive cells. The effect of IL-12 was dependent on the presence of nonmonocytic cells and could be completely blocked with an IFN-gamma antiserum. Treatment of LPS-desensitized pure monocytes with IFN-gamma or GM-CSF resulted in a very high TNF-alpha expression and no difference to cytokine-primed naive monocytes was evident any longer. While IFN-gamma and IL-12 decreased IL-10 expression in naive PBMC, it was increased by both and by GM-CSF in LPS-tolerant cultures. Again, only IL-12 was dependent on the presence of nonmonocytic cells. For prevention of LPS tolerance, similar results were obtained. Recently, we have shown that IL-10 and TGF-beta mediate LPS desensitization in vitro and can be used to establish LPS hyporesponsiveness in the absence of LPS. IFN-gamma and GM-CSF prevented and reversed down-regulation of TNF-alpha and IL-10 synthesis also in the model of IL-10/TGF-beta1-induced LPS hyporesponsiveness, while IL-12 was ineffective because of its obvious inability to induce IFN-gamma. In summary, after LPS desensitization/hyporesponsiveness, IFN-gamma and GM-CSF tended to normalize pro- and anti-inflammatory monocytic behavior. Our results suggest that during LPS desensitization/hyporesponsiveness, monocytes acquire a hitherto unknown functional state with an altered reaction to biologic response modifiers. 相似文献
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We studied 11 patients with transient global amnesia (TGA) and ten patients with functional retrograde amnesia (FRA). Patients with TGA had a uniform clinical picture: a severe, relatively isolated amnesic syndrome that started suddenly, persisted for 4-12 h, and then gradually improved to essentially normal over the next 12-24 h. During the episode, the patients had severe anterograde amnesia for verbal and non-verbal material and retrograde amnesia that typically covered at least two decades. Thirty hours to 42 days after the episode, the patients had recovered completely and performed normally on tests of anterograde and retrograde amnesia. By contrast, patients with FRA had a sudden onset of memory problems that were characterized by severe retrograde amnesia without associated anterograde amnesia and with a clinical presentation that otherwise varied considerably. The episodes persisted from several weeks to more than two years, and some of the patients had not recovered at the time of our last contact with them. The uniform clinical picture of TGA and the variable clinical picture of FRA presumably reflect their respective neurologic ('organic') and psychogenic ('non-organic') aetiologies. 相似文献