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21.
Danel Thierry; Cottencin Olivier; Tisserand Laurence; Touitou Yvan 《Alcohol and alcoholism (Oxford, Oxfordshire)》2009,44(1):42-45
Aims: The inversion of melatonin circadian rhythm secretionin some alcoholics during both intake and acute withdrawal hasbeen widely reported. In the same way, what happens to thisinversion when these patients are in long-term withdrawal isnot known. To document this abnormality in alcoholics afterwithdrawal we investigated melatonin secretion observed duringchronic alcoholization and after withdrawal. Methods: We measuredthe urinary 6-sulfatoxymelatonin (6SM) (6SM/creatinine ratio),main metabolite of the hormone, in two fractions, one diurnaland the other nocturnal, in seven alcohol-dependent patientspresenting with this abnormality during alcoholization at twotimes: in acute withdrawal phase (under benzodiazepines) and15 days after beginning of withdrawal (free of any psychotropictreatment). Results: Our results show that this reversed rhythmof melatonin secretion as seen by the diurnal excretion of 6SM(6SM/creatinine ratio) persists during acute withdrawal in morethan half of the patients and is still present 15 days afterwithdrawal in three patients. Conclusion: It is remarkable thatthe inversion of the melatonin rhythms gets corrected in fourout of seven patients after withdrawal. But, the circadian disorganizationof melatonin secretion in three patients could underline a desynchronizationin some alcoholic patients and may indicate more widespreadcircadian temporal structure disturbances in these patients. 相似文献
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Summary The MCF-7 cell S9 fraction and whole MCF-7 cells can mediate one-electron-redox cycling of doxorubicin, giving rise to concomitant oxidation of reduced nicotinamide adenine dinucleotide phosphate (NADPH), formation of a drug semiquinone free radical, consumption of molecular oxygen and formation of superoxide anions and hydroxyl radicals. Doxorubicin redox cycling was consistent with DNA strand breakage and cell kill in MCF-7 cells. In contrast, no evidence for redox cycling was found for mitoxantrone (MIT), CI941 or ametantrone (AMET) in MCF-7 cells. Despite the absence of redox cycling, the CI941, MIT, and AMET concentrations resulting in 50% mortality (LC50; 1.5×10–10, 5.2×10–9 and 1.2×10–6
m, respectively) of MCF-7 cells were lower than that of DOX (3.0×10–6
m). Furthermore, the higher cytotoxicity of MIT and CI941 as compared with AMET or DOX was associated with greater efficiency in inducing DNA strand breakage in MCF-7 cells as determined by alkaline elution. Sine MIT and CI941 proved to be the most potent DNA-damaging and cytotoxic agents in this study, the ability of DOX to undergo redox cycling does not appear to confer increased cytotoxic potential on this agent. The present study revealed several important aspects with regards to the structural modification of anthraquinone antitumour agents. Firstly, the C1 and C4 postitioning of the hydroxyethylamino side chains on MIT, CI941 and AMET is associated with a lack of flavin reductase-mediated activation of these agents. Secondly, the possession of a C5 or C8 aromatic hydroxyl group appears to be intimately involved in the enhanced DNA strand breakage and cytotoxic potency of MIT and CI941, since AMET does not possess these groups. These findings indicate that future development of quinone antitumour agents should concentrate on compounds that do not undergo redox cycling but do possess aromatic hydroxyl groups, since the latter appear to be responsible for the enhanced cytotoxicity of MIT and CI941.Abbreviations DOX
doxorubicin
- MIT
mitoxantrone
- AMET
ametantrone
- SOD
superoxide dismutase
- DMPO
5,5-dimethyl-1-pyrroline-N-oxide
- ESR
electron spin resonance
- SSF
strand scission factor
This work was funded by the Cancer Research Campaign (UK) 相似文献
24.
Reflective inquiry in nursing practice or 'revealing images' 总被引:1,自引:0,他引:1
Penelope Cash Jenny Brooker Wendy Penney Janet Reinbold Laurence Strangio 《Nursing inquiry》1997,4(4):246-256
Reflective inquiry in nursing practice or 'revealing images' Nurses live and work in complex practice worlds; worlds of shrinking resources and expanding needs. Reflection through journaling offers unique opportunities to gain insight into practice. What might we learn from one's journal? A reflective journal can be a source of interplay between the self as written and the self as other. Likewise, the journal may act to situate ourselves in practice, while at the same time enabling us to illuminate how and in what ways our understandings have become distorted. The extent to which one's journal is educative depends upon the manner in which one chooses to use it as a transformative tool, a tool that might well be described as a process of healing and enlightenment. In order to illustrate the reflexive nature of journaling, this paper is presented as a play reading, where a conversation about practice stories between the different aspects of the nurse's self is depicted. In adopting a play reading, an alternative pedagogical tool is used to illustrate different methodologies exemplifying the emergence of how and in what ways we develop and reconstruct our understanding in nursing. 相似文献
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In reaction time (RT) tasks, event-related potentials (ERPs) reveal a response-locked negative wave when subjects commit errors. This wave, termed "error negativity" (Ne) or "error-related negativity" (ERN), is thought to index response-monitoring processes. With conventional monopolar recordings, this negativity is hardly seen on correct responses, likely overlapped by a large positive wave. Indeed, after Laplacian transformation (a spatial high-pass filter), a small Ne-like wave is unmasked. Recently, it has been shown that the positivity on monopolar recordings was larger for correct responses preceding an error than for correct responses preceding a correct trial. After Laplacian transformation, it appears that this effect is due, at least in part, to a decrease of the Ne-like wave on correct responses preceding an error. This result indicates that, as the Ne on errors, the Ne-like wave on correct responses is sensitive to performance and hence is likely related to response-monitoring processes. 相似文献
27.
The Modality Specificity of the Slow Negative Wave 总被引:1,自引:0,他引:1
Event-related potentials were recorded in a simple reaction time task using a 3-sec interval between S1 and S2. The sensory modalities of S1 and S2 were varied across 4 conditions to yield all possible combinations of tones and flashes. A negative component which peaked between 600 and 800 msec after S1 was specific in scalp distribution to the modality of S1 but not S2. It was concluded that this negative component is a response to S1 and not related to processes associated with anticipation of S2. A slow negative shift which peaked at S2 was largest at the vertex in all conditions, suggesting its motor origin. A trend for the latter activity to be more negative in posterior recordings when S2 was visual than auditory leaves open the possibility that the terminal CNV is a combination of motor activities and anticipation of the sensory modality of S2. 相似文献
28.
Brémond-Gignac D Crolla JA Copin H Guichet A Bonneau D Taine L Lacombe D Baumann C Benzacken B Verloes A 《European journal of human genetics : EJHG》2005,13(4):409-413
Aniridia, Wilms tumor, genitourinary abnormalities, growth and mental retardation are the cardinal features of the WAGR 11p13 deletion syndrome. The Potocki-Schaffer syndrome or proximal 11p deletion syndrome (previously DEFECT11 syndrome) is a contiguous gene syndrome associated with deletions in 11p11.2, principal features of which are multiple exostoses and enlarged parietal foramina. Mental handicap, facial dysmorphism and craniosynostosis may also be associated. We report a patient with combined WAGR and Potocki-Shaffer syndromes, and obesity. She presented with aniridia, cataract, nystagmus, corneal ulcers and bilateral congenital ptosis. A left nephroblastoma was detected at 15 months. Other features included moderate developmental delay, growth deficiency, facial dysmorphism, multiple exostoses and cranial lacunae. High-resolution and molecular cytogenetics confirmed a del(11)(p11.2p14.1) deletion with a proximal breakpoint between the cosmid DO8153 and the BAC RP11-104M24 to a distal breakpoint between cosmids CO8160 (D11S151) and F1238 (D11S1446). The deletion therefore includes EXT2, ALX4, WT1 and PAX6. This case appears to be the second patient reported with this combined deletion syndrome and confirms the association of obesity in the WAGR spectrum, a feature previously reported in four cases, and for which the acronym WAGRO has been suggested. Molecular and follow-up data on the original WAGRO case are briefly presented. 相似文献
29.
Owens EB Hinshaw SP Kraemer HC Arnold LE Abikoff HB Cantwell DP Conners CK Elliott G Greenhill LL Hechtman L Hoza B Jensen PS March JS Newcorn JH Pelham WE Severe JB Swanson JM Vitiello B Wells KC Wigal T 《Journal of consulting and clinical psychology》2003,71(3):540-552
Using receiver operating characteristics, the authors examined outcome predictors (variables associated with outcome regardless of treatment) and moderators (variables identifying subgroups with differential treatment effectiveness) in the Multimodal Treatment Study of Children with Attention-Deficit/Hyperactivity Disorder (ADHD; MTA). Treatment response was determined using parent- and teacher-reported ADHD and oppositional defiant symptoms, with levels near or within the normal range indicating excellent response. Among 9 baseline child and family characteristics, none predicted but 3 moderated treatment response. In medication management and combined treatments, parental depressive symptoms and severity of child ADHD were associated with decreased rates of excellent response; when these 2 characteristics were present, below-average child IQ was an additional moderator. No predictors or moderators emerged for behavioral and community comparison treatments. The authors discuss conceptual and clinical implications of research on treatment moderators. 相似文献
30.
Laurence Abrami Frédérique Tacnet Pierre Ripoche 《Pflügers Archiv : European journal of physiology》1995,430(3):447-458
Permeabilities to glycerol and small non-electrolytes of three Aquaporin 1 CHIP (AQP1) water channels were measured in AQP1 cRNA-injected Xenopus laevis oocytes and in human AQP1 channels reconstituted in proteoliposomes. By an osmotic swelling assay, significant increases of ethylene glycol, glycerol and 1,3-propanediol apparent permeability coefficients (Psolutes) were found in oocytes expressing human, rat and frog AQP1. p-Chloromercuribenzene sulphonate (PCMBS) and CuSO4 inhibited, by 95% and 58% respectively, apparent glycerol permeability (P
gly) in oocytes expressing human AQP1. pCMBS inhibition was reversed by -mercaptoethanol and CuSO4 inhibition was partly reversed by the Cu2+-binding peptide Gly-Gly-His. Tritiated glycerol uptakes confirmed the augmented P
gly value of AQP1 cRNA-injected oocytes. In contrast, no increases of urea, meso-erythritol, D- or L-threitol, xylitol and mannitol uptakes were detected. Stopped-flow light scattering experiments performed with human AQP1 proteoliposomes also revealed a much greater increase of P
gly than did those with protein-free liposomes; the initial rate of proteoliposomes also swelling was inhibited by 96.2% with HgCl2 and by 72.5% with CuSO4. In AQP1 cRNA-injected oocytes and in proteoliposomes, the value of the glycerol reflection coefficient was 0.74–0.80, indicating that water and glycerol share the same pathway. All these results provide strong evidence that water and certain small solutes permeate the AQP1 channels expressed at the surface of X. laevis oocytes or reconstituted in proteoliposomes. The urea exclusion suggests that the selectivity of the AQP1 channels not only depends on the size of the solutes but probably also on their flexibility and their ability to form H-bonds. 相似文献