Atabrine has been available for nearly 60 years. It has a variety of actions and has been administered to millions of individuals. Its antirheumatic properties have been well documented but have not been exploited optimally for a variety of reasons. The drug is generally quite safe and could be used in low doses in lupus and rheumatoid arthritis patients as a steroid-sparing agent or synergistically with hydroxychloroquine. Its bothersome side effects should not deter the clinician from using it, because they are easy to deal with or prevent (Table 5). Future studies should attempt to better characterize the immunosuppressive actions of this powerful drug, particularly in the treatment of lupus erythematosus and rheumatoid arthritis. Studies of the role of combination or single-agent antimalarial therapy in combination with other "remittive" drugs could be of great potential benefit. 相似文献
The modifying effects of quinacrine administration during the post-initiation phase of carcinogenesis were investigated in hamsters treated with N -nitrosobis(2-oxopropyl)amine (BOP). Female Syrian hamsters were given three weekly s.c. injections of BOP at a dose of 10 mg/kg and then 300 or 100 ppm quinacrine in their diet for 37 weeks. Additional groups of animals received the BOP injection alone, or only the 300 ppm quinacrine treatment as BOP-negative controls. At week 40 of the experiment, all surviving animals were killed and development of proliferative lesions was assessed histopathologically. The multiplicity of pancreatic adenocarcinomas and dysplastic lesions per hamster was significantly higher ( P <0.01 and P <0.05) in the BOP/Q100 group (1.92 and 1.78) than in the BOP-alone group (1.07 and 0.79). The incidence of hepatocellular adenomas plus carcinomas was also significantly elevated ( P <0.05) in the BOP/Q300 and BOP/Q100 groups. In contrast, the multiplicity of lung adenomas plus adenocarcinomas was significantly decreased ( P <0.05) by the Q300 treatment. Neither the incidence nor the multiplicity of renal cell tumors (adenomas and carcinomas) or nephroblastomas significantly differed between the BOP-treated groups. Electron microscopic examination revealed an abundance of myeloid lamellar bodies filling the cytoplasm of hepatocytes and pancreatic ductular and acinar cells, and epithelial cells of the gallbladder in the quinacrine-treated animals, the degree being dose-dependent. Our results indicate that quinacrine enhances pancreatic and hepatic carcinogenesis in hamsters induced by BOP. 相似文献
ObjectiveTo evaluate the effectiveness and tolerability of secnidazole combined with high-dose mebendazole for treatment of 5-nitroimidazole-resistant giardiasis.MethodAdults with microscopically verified Giardia intestinalis monoinfection attending a secondary level hospital in Matanzas City, Cuba were prospectively included in a cohort. A recently introduced treatment ladder consisting of metronidazole as first-line treatment, followed by secnidazole, tinidazole, secnidazole plus mebendazole and quinacrine as second-to fifth-line treatments, respectively, was used. Adverse events and treatment success were determined by questioning and microscopy on concentrated stool samples, respectively on days 3, 5 and 7 after the end of treatment. If G. intestinalis was detected on day 3, 5 or 7, then the infection was classified as refractory and no further microscopy was performed.ResultsA total of 456 individuals were included. Metronidazole, 500 mg three times daily for 5 days, cured 248/456 (54%) patients. A single 2-g secnidazole dose as second-line treatment cured 50/208 (24%) patients. A single 2-g tinidazole dose as third-line treatment cured 43/158 (27%) patients. Three rounds of 5-nitroimidazole therapy therefore cured 341/456 (75%) patients. Secnidazole plus mebendazole (200 mg every 8 hours for 3 days) cured 100/115 (87%) of nitroimidazole refractory infections. Quinacrine cured the remaining 15 patients. All treatments were well tolerated.Conclusions5-Nitroimidazole refractory giardiasis was common, indicating that an alternative first-line treatment may be needed. Retreatment of metronidazole refractory giardiasis with an alternative 5-nitroimidazole was suboptimal, indicating cross-resistance. Mebendazole plus secnidazole were well tolerated and effective for the treatment of 5-nitroimidazole refractory G. intestinalis infection in this setting. 相似文献
The effect of acute quinacrine treatment on agonist-induced nitric oxide (NO) release was investigated in cultured human endothelial cells using electrochemical monitoring of the in situ NO concentration. Quinacrine dose-dependently increased NO release with an apparent EC50 of 0.2 microM and a maximal effect at 1 microM. Quinacrine did not modify the dependence of NO release on extracellular L-arginine. Acceleration or deceleration of O2- dismutation, which altered NO release in control cells, did not modify it in quinacrine-treated cells. Quinacrine did not modify NO amperometric signal or reaction with O2- produced by xanthine oxidation. In the presence of quinacrine, agonist-induced NO release became Mg2+ -independent and could not be attributed to an inhibition of phospholipase A2 activity. Quinacrine made NO release insensitive to Cu2+ chelation. The present study demonstrates that acute treatment by low quinacrine concentrations increases endothelial NO release, possibly through an inhibition of O2- production. 相似文献
Summary Blue light stimulates the formation of giant sporangiophores (macrophores) and inhibits the formation of dwarf sporangiophores (microphores) in Phycomyces grown under certain conditions. The thresholds for these responses are lower than the threshold for phototropism of the macrophores. Mutants in genes madA and madB, originally isolated because of the defective phototropism of their macrophores, are also defective in photomacrophorogenesis and photomicrophorogenesis. These effects of light on mycelial development are thus mediated by gene products involved in the behavioural responses of the macrophores.Another effect of light, the drastic growth inhibition of Phycomyces in 0.18 mM quinacrine, is seemingly independent of the mad sensory pathway. 相似文献
Quinacrine (QU), a phospholipase-A2 (PLA-2) inhibitor has been used clinically as a chemotherapeutic adjuvant. To understand the mechanisms leading to its chemotherapeutic effect, we have investigated QU-induced apoptotic signaling pathways in human cervical squamous carcinoma HeLa cells. In this study, we found that QU induced cytochrome c-dependent apoptotic signaling. The release of pro-apoptotic cytochrome c was QU concentration- and time-dependent, and preceded activation of caspase-9 and -3. Flow cytometric FACScan analysis using fluorescence intensities of DiOC6 demonstrated that QU-induced cytochrome c release was independent of mitochondrial permeability transition (MPT), since the concentrations of QU that induced cytochrome c release did not alter mitochondrial membrane potential (delta pai(m)). Moreover, kinetic analysis of caspase activities showed that cytochrome c release led to the activation of caspase-9 and downstream death effector, caspase-3. Caspase-3 inhibitor (Ac-DEVD-CHO) partially blocked QU-induced apoptosis, suggesting the importance of caspase-3 in this apoptotic signaling mechanism. Supplementation with arachidonic acid (AA) sustained caspase-3 activation induced by QU. Using inhibitors against cellular arachidonate metabolism of lipooxygenase (Nordihydroxyguaiaretic Acid, NDGA) and cyclooxygenase (5,8,11,14-Eicosatetraynoic Acid, ETYA) demonstrated that QU-induced apoptotic signaling may be dependent on its role as a PLA-2 inhibitor. Interestingly, NDGA attenuated QU-induced cytochrome c release, caspase activity as well as apoptotic cell death. The blockade of cytochrome c release by NDGA was much more effective than that attained with cyclosporin A (CsA), a MPT inhibitor. ETYA was not effective in blocking cytochrome c release, except under very high concentrations. Caspase inhibitor z-VAD blocked the release of cytochrome c suggesting that this signaling event is caspase dependent, and caspase-8 activation may be upstream of the mitochondrial events. In summary, we report that QU induced cytochrome c-dependent apoptotic signaling cascade, which may be dependent on its role as a PLA-2 inhibitor. This apoptotic mechanism induced by QU may contribute to its known chemotherapeutic effects. 相似文献
Objective: To determine the long-term safety of nonsurgical sterilization with quinacrine.
Design: Observational cohort study.
Setting: Rural provinces in northern Vietnam.
Patient(s): Two thousand eight hundred forty women who had had quinacrine insertions and an age-matched comparison group of 1,658 women who had an intrauterine device (IUD) insertion between 1989 and 1993.
Method(s): Interviews in 1994, 1995, and 1996 and review of available medical records. This is a planned interim analysis.
Main Outcome Measure(s): Ectopic pregnancies and the occurrence of other adverse health events.
Result(s): Over 90% of women were interviewed at least once. Despite matching on age, the groups differed on baseline parity. The ectopic pregnancy rates were similar after either one or two insertions and were similar to the rate of ectopic pregnancies after surgical sterilization in the United States. The quinacrine group reported more gynecologic health problems than the IUD group. However, after correcting for information bias, there was no dose–response effect between the one- and two-insertion quinacrine groups, suggesting the possibility of recall bias or differing baseline health status.
Conclusion(s): Ectopic pregnancies do not appear to be increased compared with U.S. surgical sterilization rates. The data on other adverse events are more difficult to interpret. 相似文献
Plasma membranes and matrix vesicles isolated from rat costochondral resting zone chondrocyte cultures contain predominantly
protein kinase C alpha (PKCα) and PKCζ, respectively, and the level of PKC specific activity in these membrane fractions is
regulated by 24,25-(OH)2D3 [14]. In the present study, we examined whether the effect of 24,25-(OH)2D3 on membrane PKC is via genomic mechanisms during biogenesis and through a nongenomic mechanism after the matrix vesicles
are resident in the matrix. There was a dose-dependent decrease in matrix vesicle PKC specific activity and a significant
increase in plasma membrane enzyme activity in cultures treated for 90 minutes with 10−9–10−7 M 24,25-(OH)2D3. However, at 12 hours, matrix vesicle PKC was stimulated, but no effect was seen in the plasma membranes, suggesting that
the effect seen at 90 minutes was due to a direct action of the hormone on PKC activity in the membrane, and that the effect
seen at 12 hours was due to new matrix vesicle production with altered PKC content. Neither actinomycin D nor cycloheximide
inhibited matrix vesicle PKC at 30, 60, or 90 minutes, but by 12 hours, these inhibitors blocked the effect of the hormone.
24,25-(OH)2D3-dependent plasma membrane PKC was sensitive to both actinomycin D and cycloheximide at early time points, but by 12 hours,
no effect of the inhibitors was seen. Monensin did not alter basal plasma membrane PKC activity or the 24,25-(OH)2D3-dependent increase, suggesting that this increase was due to translocation of cytosolic PKC rather than new membrane synthesis.
Monensin did not affect matrix vesicle PKC at early time points, but it decreased 24,25-(OH)2D3-dependent enzyme activity at later times, indicating that new matrix vesicle production was blocked.
At least part of the effect of 24,25-(OH)2D3 on PKC involved phospholipase A2 (PA2). Quinacrine (a PA2 inhibitor) alone had no effect on matrix vesicle PKC, but in cultures treated for 12 hours with quinacrine and 24,25-(OH)2D3, a synergistic increase in matrix vesicle PKC was observed. Quinacrine caused a time-dependent decrease in matrix vesicle
PKC and a dose- and time-dependent increase in plasma membrane PKC when incubated directly with the membranes, supporting
the hypothesis that PA2 plays a role in the nongenomic regulation of PKC by 24,25-(OH)2D3. Experiments using anti-isoform specific antibodies showed that 24,25-(OH)2D3 modulated the distribution of PKCα, β, and ζ between the plasma membrane and matrix vesicle compartments via translocation
and new PKC synthesis. Thus, the data support the hypothesis that 24,25-(OH)2D3 regulates matrix vesicles through two pathways: a genomic one at the stage of biosynthesis and packaging, and a second nongenomic
mechanism acting directly upon matrix vesicles in the matrix. These data also indicate that matrix vesicle regulation consists
of complex events with several different points of regulation.
Received: 11 October 1996 / Accepted: 25 April 1997 相似文献
Dating back to the 1970s, thousands of women worldwide have voluntarily been sterilized with transcervical insertion of quinacrine pellets. The safety and efficacy of the technology are still being assessed today; in particular, better estimates on the incidence of human cancers are now feasible.
Methods
We conducted a cohort study of 1492 women in Santiago and Valdivia, Chile, who received transcervical quinacrine pellets for contraceptive sterilization between l977 and l989. We periodically interviewed women with the last interviews in 2006-2007 and reviewed their medical records. We calculated age and site-specific incidence of invasive cancers and compared the observed cases to the number of expected cases based on data from the Cali, Colombia, cancer registry, gathered by the International Agency for Research on Cancer.
Results
During 23,894 person-years of follow-up, 41 invasive cancers were identified, including 16 new cases that had occurred since the previous analysis. Ten cases of cervical cancer were observed, compared with 12.1 expected. Since the initial study's confirmation of a single case of leiomyosarcoma, no other uterine cancers have been diagnosed. We would expect 2.0 uterine cancers during this number of observed women-years. One case of ovarian cancer was diagnosed, compared with 3.1 expected.
Conclusion
Rates of cancer among women exposed to intrauterine quinacrine are similar to population-based rates. 相似文献