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排序方式: 共有919条查询结果,搜索用时 31 毫秒
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Learning in monkeys exposed perinatally to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) 总被引:3,自引:0,他引:3
TCDD is an extremely toxic chemical pollutant which bioaccumulates in maternal adipose tissue, and is transferred to the developing organism during gestation and lactation. Long-term cognitive deficits have been reported following perinatal exposure to polychlorinated biphenyls, which are structurally and toxicologically similar to TCDD. In the current study, monkeys exposed to TCDD perinatally were later tested in two cognitive paradigms, discrimination-reversal learning (RL) and delayed spatial alternation (DSA). RL detected effects; whereas DSA, as analyzed, did not. RL consisted of a series of simple spatial reversals, followed by spatial reversals with color and shape as irrelevant cues, then by color reversals and finally by shape reversals. TCDD-exposed monkeys exhibited retarded learning of the shape reversals. The deficit was most pronounced on the first reversal following overtraining. There were no group differences on the spatial or color reversals. However, the number of trials the TCDD-exposed monkeys individually took to learn the spatial reversals was positively correlated with TCDD concentration in body fat. Conversely, the number of trials they took to learn the color reversals was negatively correlated with TCDD in body fat. 相似文献
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Lb Jensen Jens Ulrik Wester Finn Rasmussen Steen Lindequist Kim Schantz 《Acta orthopaedica》1994,65(4):398-400
14 children suffering from a fracture of the talar neck or body were examined after 21 (7-34) years. The talar neck was fractured in 10 children and the talar body in 4. 3 fractures were displaced and primarily treated with reduction and immobilization. Nondisplaced fractures were treated conservatively. All fractures healed. All patients with displaced fractures had exercise-induced pain at follow-up. Of 11 patients with nondisplaced fractures only 1 had minor complaints.
CT and conventional radiographs showed arthrosis in the talocrural joint and normal subtalar joints in those with displaced fractures. The radio- graphic findings were normal after nondisplaced fractures. 相似文献
CT and conventional radiographs showed arthrosis in the talocrural joint and normal subtalar joints in those with displaced fractures. The radio- graphic findings were normal after nondisplaced fractures. 相似文献
6.
Heukrodt Carol; Powazek Morris; Brown Warren S.; Kennelly Denise; Imbus Charles; Robinson Herb; Schantz Stacy 《Journal of pediatric psychology》1988,13(2):223-236
The long-term effects of disease and treatment on electrophysiologicalmeasures of neurocognitive function were studied in childrenwho had survived acute lymphoblastic leukemia (ALL) for at least4 years and were currently in remission. We report here changesin cognitive processing time as shown by the latency of theP3 wave of the auditory event-related EEG potential (ERP). P3latency was significantly prolonged in long-term ALL surivors,as well as in patients successfully trreated for solid tumors(ST)outside the CNS who received similar chemotherapy but did notreceive prophylactic treatment to the CNS. P3 latencies werestrongly correlated with measures of school performance andIQ in these individuals. The similarity in P3 latency betweenthe ALL and ST groups suggests that the treatments used on thesepateints produce changes in electrophysiological responses thatare associated with mild, but significant, cognitive deficits. 相似文献
7.
William W. Yotis Nicholas Catsimpoolas Merlin S. Bergdoll Edward J. Schantz 《Infection and immunity》1974,9(5):974-976
Purified Staphylococcus aureus enterotoxins B and C(1), the causative agents of staphylococcal food poisoning, were resolved into several components by scanning isoelectric focusing in sucrose density gradients in the absence and presence of 6 M urea and 5 mM dithiothreitol. The observed heterogeneity persisted in the denaturing medium, which suggests that the primary structure of protein enterotoxins B and C(1) may be partly responsible for the isoelectric point differences of the various forms. To our knowledge, the scanning isoelectric focusing patterns of staphylococcal enterotoxins B and C(1) are reported for the first time. 相似文献
8.
Relative carriage rates of nuclear dehydrogenating clostridia in two populations of different colorectal cancer risk 下载免费PDF全文
Carriage of nuclear dehydrogenating clostridia has been associated with colon cancer and implicated in its aetiology. This study has compared the carriage of these organisms in a British population at high risk for the development of colon cancer with a low risk Nigerian population. Clostridia were found in all of the stools from both populations. Nuclear dehydrogenating clostridia were only found in the stools of the British subjects (32%). These results support the suggestion that the carriage rate of nuclear dehydrogenating clostridia in a population is related to the risk of colon cancer. 相似文献
9.
Jinghua Jin Feng-Shiun Shie Jun Liu Yan Wang Jeanne Davis Aimee M Schantz Kathleen S Montine Thomas J Montine Jing Zhang 《Journal of neuroinflammation》2007,4(1):2-10
Background
The pathogenesis of idiopathic Parkinson's disease (PD) remains elusive, although evidence has suggested that neuroinflammation characterized by activation of resident microglia in the brain may contribute significantly to neurodegeneration in PD. It has been demonstrated that aggregated α-synuclein potently activates microglia and causes neurotoxicity. However, the mechanisms by which aggregated α-synuclein activates microglia are not understood fully. 相似文献10.
Development of hatching blastocysts from immature human oocytes following in-vitro maturation and fertilization using a co-culture system 总被引:8,自引:0,他引:8
Hwu YM; Lee RK; Chen CP; Su JT; Chen YW; Lin SP 《Human reproduction (Oxford, England)》1998,13(7):1916-1921
Recently, in-vitro maturation (IVM) of immature human oocytes recovered
from non-stimulated follicles has been applied in the treatment of
infertility. However, in previous reports, very few embryos cultured in
conventional medium have reached the expanded blastocyst stage following
in-vitro maturation and fertilization (IVM/IVF). The objective of this
study was to investigate whether the developmental competence of human
embryos following IVM/IVF could be enhanced by the use of a human ampullary
cell co-culture system. Immature human oocytes were aspirated from small
follicles at Caesarean section and then cultured in medium containing human
menopausal gonadotrophin for 36 to 48 h, followed by insemination. Zygotes
were randomly cultured either in conventional culture medium alone or in
the co-culture system. Of 48 embryos cultured in conventional medium alone,
all arrested at the 2-16- cell stage on day 3 after insemination. Of 46
embryos cultured in the co-culture system, 26 embryos (56.5%) arrested at
the 2-16-cell stage. Six embryos (13%) developed to the morula stage.
Fourteen embryos (30.4%) developed to expanded blastocysts and two
blastocysts were hatching on day 7 after insemination. We conclude that
co-culture significantly enhances the development of blastocysts in embryos
resulting from IVM/IVF.
相似文献