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121.
Dueling activities of AIF in cell death versus survival: DNA binding and redox activity 总被引:10,自引:0,他引:10
Apoptosis-inducing factor (AIF) was originally discovered as a mitochondrial protein that, like cytochrome c, is released into the cytoplasm during cell death. New evidence suggests, however, that a redox-active enzymatic region of AIF may be antiapoptotic while a DNA binding region is proapoptotic. 相似文献
122.
Retroviral Recombination Rates Do Not Increase Linearly with Marker Distance and Are Limited by the Size of the Recombining Subpopulation 总被引:8,自引:7,他引:1 下载免费PDF全文
Recombination occurs at high frequencies in all examined retroviruses. The previously determined homologous recombination rate in one retroviral replication cycle is 4% for markers 1.0 kb apart in spleen necrosis virus (SNV). This has often been used to suggest that approximately 30 to 40% of the replication-competent viruses with 7- to 10-kb genomes undergo recombination. These estimates were based on the untested assumption that a linear relationship exists between recombination rates and marker distances. To delineate this relationship, we constructed three sets of murine leukemia virus (MLV)-based vectors containing the neomycin phosphotransferase gene (neo) and the hygromycin phosphotransferase B gene (hygro). Each set contained one vector with a functional neo and an inactivated hygro and one vector with a functional hygro and an inactivated neo. The two inactivating mutations in the three sets of vectors were separated by 1.0, 1.9, and 7.1 kb. Recombination rates after one round of replication were 4.7, 7.4, and 8.2% with markers 1.0, 1.9, and 7.1 kb apart, respectively. Thus, the rate of homologous recombination with 1.0 kb of marker distance is similar in MLV and SNV. The recombination rate increases when the marker distance increases from 1.0 to 1.9 kb; however, the recombination rates with marker distances of 1.9 and 7.1 kb are not significantly different. These data refute the previous assumption that recombination is proportional to marker distance and define the maximum recombining population in retroviruses. 相似文献
123.
Keith Hawton Ella Arensman Ellen Townsend Sandy Bremner Eleanor Feldman Robert Goldney David Gunnell Philip Hazell Kees van Heeringen Allan House David Owens Isaac Sakinofsky Lil Tr?skman-Bendz 《BMJ (Clinical research ed.)》1998,317(7156):441-447
Objective: To identify and synthesise the findings from all randomised controlled trials that have examined the effectiveness of treatments of patients who have deliberately harmed themselves. Design: Systematic review of randomised controlled trials of psychosocial and physical treatments. Studies categorised according to type of treatment. When there was more than one investigation in a particular category a summary odds ratio was estimated with the Mantel-Haenszel method. Setting: Randomised trials available in electronic databases in 1996, in the Cochrane Controlled Trials Register in 1997, and from hand searching of journals to 1997. Subjects: Patients who had deliberately harmed themselves shortly before entry into the trials with information on repetition of behaviour. The included trials comprised 2452 randomised participants with outcome data. Main outcome measure: Repetition of self harm. Results: 20 trials reported repetition of self harm as an outcome variable, classified into 10 categories. Summary odds ratio (all for comparison with standard aftercare) indicated reduced repetition for problem solving therapy (0.73; 95% confidence interval 0.45 to 1.18) and for provision of an emergency contact card in addition to standard care (0.45; 0.19 to 1.07). The summary odds ratios were 0.83 (0.61 to 1.14) for trials of intensive aftercare plus outreach and 1.19 (0.53 to 2.67) for antidepressant treatment compared with placebo. Significantly reduced rates of further self harm were observed for depot flupenthixol versus placebo in multiple repeaters (0.09; 0.02 to 0.50) and for dialectical behaviour therapy versus standard aftercare (0.24; 0.06 to 0.93). Conclusion: There remains considerable uncertainty about which forms of psychosocial and physical treatments of patients who harm themselves are most effective. Further larger trials of treatments are needed.
Key messages
- A systematic review of the effectiveness of psychosocial and drug treatments of patients who deliberately harm themselves identified 20 randomised controlled trials in which repetition of self harm was reported as an outcome
- Promising results were found for problem solving therapy, provision of a card to allow patients to make emergency contact with services, depot flupenthixol for recurrent self harm, and long term psychological therapy for female patients with borderline personality disorder and recurrent self harm
- Assertive outreach can help to keep patients in treatment
- Nearly all the trials included too few patients to detect clinically significant differences in repetition of self harm, and even synthesis of results by meta-analysis did not have the power to detect such differences
- There is an urgent need for large trials of promising therapies for this substantial clinical population
124.
Georgina Arrambide Carmen Espejo Jennifer Yarden Ella Fire Larissa Spector Nir Dotan Avinoam Dukler Alex Rovira Xavier Montalban Mar Tintore 《PloS one》2013,8(3)
Background
Anti-glycan antibodies can be found in autoimmune diseases. IgM against glycan P63 was identified in clinically isolated syndromes (CIS) and included in gMS-Classifier2, an algorithm designed with the aim of identifying patients at risk of a second demyelinating attack.Objective
To determine the value of gMS-Classifier2 as an early and independent predictor of conversion to clinically definite multiple sclerosis (CDMS).Methods
Data were prospectively acquired from a CIS cohort. gMS-Classifier2 was determined in patients first seen between 1995 and 2007 with ≥ two 200 µL serum aliquots (N = 249). The primary endpoint was time to conversion to CDMS at two years, the factor tested was gMS-Classifier2 status (positive/negative) or units; other exploratory time points were 5 years and total time of follow-up.Results
Seventy-five patients (30.1%) were gMS-Classifier2 positive. Conversion to CDMS occurred in 31/75 (41.3%) of positive and 45/174 (25.9%) of negative patients (p = 0.017) at two years. Median time to CDMS was 37.8 months (95% CI 10.4–65.3) for positive and 83.9 months (95% CI 57.5–110.5) for negative patients. gMS-Classifier2 status predicted conversion to CDMS within two years of follow-up (HR = 1.8, 95% CI 1.1–2.8; p = 0.014). gMS-Classifier2 units were also independent predictors when tested with either Barkhof criteria and OCB (HR = 1.2, CI 1.0–1.5, p = 0.020) or with T2 lesions and OCB (HR = 1.3, CI 1.1–1.5, p = 0.008). Similar results were obtained at 5 years of follow-up. Discrimination measures showed a significant change in the area under the curve (ΔAUC) when adding gMS-Classifier2 to a model with either Barkhof criteria (ΔAUC 0.0415, p = 0.012) or number of T2 lesions (ΔAUC 0.0467, p = 0.009), but not when OCB were added to these models.Conclusions
gMS-Classifier2 is an independent predictor of early conversion to CDMS and could be of clinical relevance, particularly in cases in which OCB are not available. 相似文献125.
Grenbäck E Bjellerup P Wallerman E Lundblad L Anggård A Ericson K Aman K Landry M Schmidt WE Hökfelt T Hulting AL 《Regulatory peptides》2004,117(2):127-139
Tumor galanin content was measured in extracts from human pituitary adenomas using a specific RIA method for monitoring human galanin. Twenty-two out of twenty-four tumors contained galanin with notably high levels in corticotroph adenomas, varying levels in clinically inactive tumors, and low levels in GH secreting adenomas. Tumor galanin and ACTH contents were closely correlated in all tumors. In four young patients with microadenomas and highly active Mb Cushing tumor galanin was inversely related to tumor volume. The molecular form of tumor galanin, studied with reverse-phase HPLC, was homogeneous with the majority of tumor galanin coeluting with standard human galanin. In the tumors analysed with in situ hybridization there was a good correlation between galanin peptide levels and galanin mRNA expression. In some tumors galanin mRNA and POMC levels coexisted, in others they were essentially in different cell populations. Levels of plasma galanin-LI were not related to tumor galanin concentration, and galanin levels were in the same range in sinus petrosus close to the pituitary venous drainage as in peripheral blood. Corticotrophin releasing hormone injections in two patients caused ACTH, but no detectable galanin release into sinus petrosus. Our results demonstrate that corticotroph, but not GH adenomas, express high levels of galanin, in addition to ACTH, and that in some tumors both polypeptides are synthesised in the same cell population. However, galanin levels in plasma were not influenced by the tumor galanin content. 相似文献
126.
127.
Regulation of gene expression of ATP-binding cassette transporter (ABC)A1 and ABCG1 by liver X receptor/retinoid X receptor (LXR/RXR) ligands was investigated in the human intestinal cell line CaCo-2. Neither the RXR ligand, 9-cis retinoic acid, nor the natural LXR ligand 22-hydroxycholesterol alone altered ABCA1 mRNA levels. When added together, ABCA1 and ABCG1 mRNA levels were increased 3- and 7-fold, respectively. T0901317, a synthetic non-sterol LXR agonist, increased ABCA1 and ABCG1 gene expression 11- and 6-fold, respectively. ABCA1 mass was increased by LXR/RXR activation. T0901317 or 9-cis retinoic acid and 22-hydroxycholesterol increased cholesterol efflux from basolateral but not apical membranes. Cholesterol efflux was increased by the LXR/RXR ligands to apolipoprotein (apo)A-I or HDL but not to taurocholate/phosphatidylcholine micelles. Actinomycin D prevented the increase in ABCA1 and ABCG1 mRNA levels and the increase in cholesterol efflux induced by the ligands. Glyburide, an inhibitor of ABCA1 activity, attenuated the increase in basolateral cholesterol efflux induced by T0901317. LXR/RXR activation decreased the esterification and secretion of cholesterol esters derived from plasma membranes. Thus, in CaCo-2 cells, LXR/RXR activation increases gene expression of ABCA1 and ABCG1 and the basolateral efflux of cholesterol, suggesting that ABCA1 plays an important role in intestinal HDL production and cholesterol absorption. 相似文献
128.
Jong-Min Lee Jie Zhang Andrew I Su John R Walker Tim Wiltshire Kihwa Kang Ella Dragileva Tammy Gillis Edith T Lopez Marie-Josee Boily Michel Cyr Isaac Kohane James F Gusella Marcy E MacDonald Vanessa C Wheeler 《BMC systems biology》2010,4(1):1-16
Background
In Huntington's disease (HD), an expanded CAG repeat produces characteristic striatal neurodegeneration. Interestingly, the HD CAG repeat, whose length determines age at onset, undergoes tissue-specific somatic instability, predominant in the striatum, suggesting that tissue-specific CAG length changes could modify the disease process. Therefore, understanding the mechanisms underlying the tissue specificity of somatic instability may provide novel routes to therapies. However progress in this area has been hampered by the lack of sensitive high-throughput instability quantification methods and global approaches to identify the underlying factors.Results
Here we describe a novel approach to gain insight into the factors responsible for the tissue specificity of somatic instability. Using accurate genetic knock-in mouse models of HD, we developed a reliable, high-throughput method to quantify tissue HD CAG repeat instability and integrated this with genome-wide bioinformatic approaches. Using tissue instability quantified in 16 tissues as a phenotype and tissue microarray gene expression as a predictor, we built a mathematical model and identified a gene expression signature that accurately predicted tissue instability. Using the predictive ability of this signature we found that somatic instability was not a consequence of pathogenesis. In support of this, genetic crosses with models of accelerated neuropathology failed to induce somatic instability. In addition, we searched for genes and pathways that correlated with tissue instability. We found that expression levels of DNA repair genes did not explain the tissue specificity of somatic instability. Instead, our data implicate other pathways, particularly cell cycle, metabolism and neurotransmitter pathways, acting in combination to generate tissue-specific patterns of instability.Conclusion
Our study clearly demonstrates that multiple tissue factors reflect the level of somatic instability in different tissues. In addition, our quantitative, genome-wide approach is readily applicable to high-throughput assays and opens the door to widespread applications with the potential to accelerate the discovery of drugs that alter tissue instability. 相似文献129.
Rat MYH,a glycosylase for repair of oxidatively damaged DNA,has brain-specific isoforms that localize to neuronal mitochondria 总被引:3,自引:0,他引:3
Mitochondrial genomes are exposed to a heavy load of reactive oxygen species (ROS) that damage DNA. Since in neurons, mitochondrial DNA integrity must be maintained over the entire mammalian life span, neuronal mitochondria most likely repair oxidatively damaged DNA. We show that the Escherichia coli MutY DNA glycosylase homolog (MYH) in rat (rMYH) involved in repair of oxidative damage is abundantly expressed in the rat brain, with isoforms that are exclusive to brain tissue. Confocal microscopy and western analyses reveal localization of rMYH in neuronal mitochondria. To assess involvement of MYH in the neuronal response to oxidative DNA damage, we used a rat model of respiratory hypoxia, in which acutely reduced blood oxygenation leads to generation of superoxide, and formation and subsequent removal of 8-hydroxy-2'-deoxyguanosine (8OHdG). Removal of 8OHdG is accompanied by a spatial increase in rMYH immunoreactivity in the brain and an increase in levels of one of the three mitochondrial MYH isoforms, suggesting that inducible and non-inducible MYH isoforms exist in the brain. The mitochondrial localization of oxidative DNA damage repair enzymes in neurons may represent a specialized neuronal mechanism that safeguards mitochondrial genomes in the face of routine and accidental exposures to heavy loads of injurious ROS. 相似文献
130.
Elisa Schneider Hanna Zimmermann Timm Oberwahrenbrock Falko Kaufhold Ella Maria Kadas Axel Petzold Frieder Bilger Nadja Borisow Sven Jarius Brigitte Wildemann Klemens Ruprecht Alexander U. Brandt Friedemann Paul 《PloS one》2013,8(6)