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921.
Aris S. Sideropoulos Judith Rae Lumb Delbert M. Shankel 《Molecular & general genetics : MGG》1968,102(2):102-107
Summary Eight compounds can be added to those purine analogs which give synergistic effects with ultraviolet light: 1,3,7,9-tetra-methylxanthine methyl sulfate, 8-chlorocaffeine, ethyltheophylline, 6-dimethylaminopurine, 6-methoxypurine, 8-ethoxycaffeine, 1,3-dimethyl uric acid and 3-methyl uric acid. It appears likely that these are merely representatives of the class of methyl purines, and that other compounds are also active. The synergistic activity varies among the compounds investigated; some give a synergistic effect slightly higher than caffeine, but apparently act by the same mechanism. The height of effect of all of the synergistic purine analogs has been correlated with the stability of the structures determined by inductive effects and steric hindrance. The lack of activity with pyrimidines (l-methyl thymine and 1,3-dimethyluracil) leads to the conclusion that both rings (7,8,9 positions) of the purine molecule are necessary for the synergistic effect.This work was supported by the National Institutes of Health Research Grant AI-05340, the University of Kansas General Research Fund, and an N.I.H. Training Grant (5 T1 GM-703) to the Department of Microbiology. 相似文献
922.
Max Bylesjö Vincent Segura Raju Y Soolanayakanahally Anne M Rae Johan Trygg Petter Gustafsson Stefan Jansson Nathaniel R Street 《BMC plant biology》2008,8(1):82
Background
An increased understanding of leaf area development is important in a number of fields: in food and non-food crops, for example short rotation forestry as a biofuels feedstock, leaf area is intricately linked to biomass productivity; in paleontology leaf shape characteristics are used to reconstruct paleoclimate history. Such fields require measurement of large collections of leaves, with resulting conclusions being highly influenced by the accuracy of the phenotypic measurement process. 相似文献923.
924.
Rae Caroline Fekete Aurélie D. Kashem Mohammed A. Nasrallah Fatima A. Bröer Stefan 《Neurochemical research》2012,37(11):2541-2553
Neurochemical Research - Acetate is a two carbon intermediate in metabolism. It is an accepted marker of astrocytic metabolism, and a substrate for production of metabolites such as glutamine,... 相似文献
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MS Nandhu Jes Paul Korah P Kuruvilla Anitha Malat Chinthu Romeo CS Paulose 《Journal of biomedical science》2011,18(1):5
Parkinson's disease is characterized by progressive cell death in the substantia nigra pars compacta, which leads to dopamine
depletion in the striatum and indirectly to cortical dysfunction. Increased glutamatergic transmission in the basal ganglia
is implicated in the pathophysiology of Parkinson's disease and glutamate receptor mediated excitotoxicity has been suggested
to be one of the possible causes of the neuronal degeneration. In the present study, the effects of serotonin, gamma-aminobutyric
acid and bone marrow cells infused intranigrally to substantia nigra individually and in combination on unilateral 6-hydroxydopamine
induced Parkinson's rat model was analyzed. Scatchard analysis of total glutamate and NMDA receptor binding parameters showed
a significant increase in Bmax (P < 0.001) in the cerebral cortex of 6-hydroxydopamine infused rat compared to control. Real Time PCR amplification of NMDA2B,
mGluR5, bax, and ubiquitin carboxy-terminal hydrolase were up regulated in cerebral cortex of 6-hydroxydopamine infused rats
compared to control. Gene expression studies of GLAST, ά-Synuclien and Cyclic AMP response element-binding protein showed
a significant (P < 0.001) down regulation in 6-OHDA infused rats compared to control. Behavioural studies were carried out
to confirm the biochemical and molecular studies. Serotonin and GABA along with bone marrow cells in combination showed reversal
of glutamate receptors and behaviour abnormality shown in the Parkinson's rat model. The therapeutic significance in Parkinson's
disease is of prominence. 相似文献
928.
C M Fernandes F Bouthillette J M Raboud L Bullock C F Moore J M Christenson E Grafstein S Rae L Ouellet C Gillrie M Way 《CMAJ》1999,161(10):1245-1248
BACKGROUND: Violence in the workplace is an ill-defined and underreported concern for health care workers. The objectives of this study were to examine perceived levels of violence in the emergency department, to obtain health care workers'' definitions of violence, to determine the effect of violence on health care workers and to determine coping mechanisms and potential preventive strategies. METHODS: A retrospective written survey of all 163 emergency department employees working in 1996 at an urban inner-city tertiary care centre in Vancouver. The survey elicited demographic information, personal definition of violence, severity of violence, degree of stress as a result of violence and estimate of the number of encounters with violence in the workplace in 1996. The authors examined the effects of violence on job performance and job satisfaction, and reviewed coping and potential preventive strategies. RESULTS: Of the 163 staff, 106 (65%) completed the survey. A total of 68% (70/103) reported an increased frequency of violence over time, and 60% (64/106) reported an increased severity. Most of the respondents felt that violence included witnessing verbal abuse (76%) and witnessing physical threats or assaults (86%). Sixty respondents (57%) were physically assaulted in 1996. Overall, 51 respondents (48%) reported impaired job performance for the rest of the shift or the rest of the week after an incident of violence. Seventy-seven respondents (73%) were afraid of patients as a result of violence, almost half (49%) hid their identities from patients, and 78 (74%) had reduced job satisfaction. Over one-fourth of the respondents (27/101) took days off because of violence. Of the 18 respondents no longer working in the emergency department, 12 (67%) reported that they had left the job at least partly owing to violence. Twenty-four-hour security and a workshop on violence prevention strategies were felt to be the most useful potential interventions. Physical exercise, sleep and the company of family and friends were the most frequent coping strategies. INTERPRETATION: Violence in the emergency department is frequent and has a substantial effect on staff well-being and job satisfaction. 相似文献
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