87 research outputs found

    Developing and Validating a Fast and Accurate Method to Quantify 18 Antidepressants in Oral Fluid Samples Using SPE and LC-MSMS

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    Antidepressant drugs are one of the most widely used medicines for treating major depressive disorders for long time periods. Oral fluid (OF) testing offers an easy and noninvasive sample collection. Detection of antidepressants in OF is important in clinical and forensic settings, such as therapeutic drug monitoring and roadside testing for driving under influence. We developed and validated a comprehensive liquid chromatography tandem mass spectrometry method for 18 antidepressants (amitriptyline, bupropion, citalopram, clomipramine, cyclobenzaprine, desipramine, desvenlafaxine, doxepin, duloxetine, fluoxetine, imipramine, mirtazapine, nortriptyline, paroxetine, sertraline, trazodone, trimipramine, venlafaxine) in oral fluid collected by Quantisal® oral collection devices. 0.5 mL of Quantisal® OF (125μL of neat OF) was submitted to solid-phase extraction. The chromatographic separation was performed employing a biphenyl column in gradient mode with a total run time of 5 min. The MS detection was achieved by multiple reaction monitoring with two transitions per compound. The range for linearity of all analytes was from 10-1,000 ng/mL, with a limit of quantitation of 10 ng/mL. Intra and Inter-day’s accuracy and precision (n=15) were all within acceptable limits, ± 20% error and ± 15% relative standard deviation. Analyte recovery at 400 ng/mL concentration (n=15) ranged from 91-129%. Matrix effect ranged from 73.7-157%. The internal proficiency test detected all antidepressants with accuracy ranging from 83.1-112.1%. The authentic patient sample showed percentage difference compare to previously calculated concentration of 86.3-111%. This method provides for the rapid detection of 18 antidepressants in OF, which is readily applicable to a routine laboratory

    BitE : Accelerating Learned Query Optimization in a Mixed-Workload Environment

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    Although the many efforts to apply deep reinforcement learning to query optimization in recent years, there remains room for improvement as query optimizers are complex entities that require hand-designed tuning of workloads and datasets. Recent research present learned query optimizations results mostly in bulks of single workloads which focus on picking up the unique traits of the specific workload. This proves to be problematic in scenarios where the different characteristics of multiple workloads and datasets are to be mixed and learned together. Henceforth, in this paper, we propose BitE, a novel ensemble learning model using database statistics and metadata to tune a learned query optimizer for enhancing performance. On the way, we introduce multiple revisions to solve several challenges: we extend the search space for the optimal Abstract SQL Plan(represented as a JSON object called ASP) by expanding hintsets, we steer the model away from the default plans that may be biased by configuring the experience with all unique plans of queries, and we deviate from the traditional loss functions and choose an alternative method to cope with underestimation and overestimation of reward. Our model achieves 19.6% more improved queries and 15.8% less regressed queries compared to the existing traditional methods whilst using a comparable level of resources.Comment: This work was done when the first three author were interns in SAP Labs Korea and they have equal contributio

    Annulation of O-silyl N,O-ketene acetals with alkynes for the synthesis of dihydropyridinones and its application in concise total synthesis of phenanthroindolizidine alkaloids

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    The formation of N-heterocycles with multiple substituents is important in organic synthesis. Herein, we report a novel method for the construction of functionalized dihydropyridinone rings through the annulation of an amide α-carbon with a tethered alkyne moiety. The reaction of the amide with the alkyne was achieved via O-silyl N,O-ketene acetal formation and silver-mediated addition. Furthermore, the developed method was applied for the total synthesis of phenanthroindolizidine and phenanthroquinolizidine alkaloids. By varying the coupling partners, a concise and collective total synthesis of these alkaloids was achieved

    Transdifferentiation-inducing HCCR-1 oncogene

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    <p>Abstract</p> <p>Background</p> <p>Cell transdifferentiation is characterized by loss of some phenotypes along with acquisition of new phenotypes in differentiated cells. The differentiated state of a given cell is not irreversible. It depends on the up- and downregulation exerted by specific molecules.</p> <p>Results</p> <p>We report here that <it>HCCR-1</it>, previously shown to play an oncogenic role in human cancers, induces epithelial-to-mesenchymal transition (EMT) and mesenchymal-to-epithelial transition (MET) in human and mouse, respectively. The stem cell factor receptor CD117/c-Kit was induced in this transdifferentiated (EMT) sarcoma tissues. This MET occurring in <it>HCCR-1 </it>transfected cells is reminiscent of the transdifferentiation process during nephrogenesis. Indeed, expression of <it>HCCR-1 </it>was observed during the embryonic development of the kidney. This suggests that <it>HCCR-1 </it>might be involved in the transdifferentiation process of cancer stem cell.</p> <p>Conclusions</p> <p>Therefore, we propose that <it>HCCR-1 </it>may be a regulatory factor that stimulates morphogenesis of epithelia or mesenchyme during neoplastic transformation.</p

    NSUN2 introduces 5-methylcytosines in mammalian mitochondrial tRNAs.

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    Expression of human mitochondrial DNA is indispensable for proper function of the oxidative phosphorylation machinery. The mitochondrial genome encodes 22 tRNAs, 2 rRNAs and 11 mRNAs and their post-transcriptional modification constitutes one of the key regulatory steps during mitochondrial gene expression. Cytosine-5 methylation (m5C) has been detected in mitochondrial transcriptome, however its biogenesis has not been investigated in details. Mammalian NOP2/Sun RNA Methyltransferase Family Member 2 (NSUN2) has been characterized as an RNA methyltransferase introducing m5C in nuclear-encoded tRNAs, mRNAs and microRNAs and associated with cell proliferation and differentiation, with pathogenic variants in NSUN2 being linked to neurodevelopmental disorders. Here we employ spatially restricted proximity labelling and immunodetection to demonstrate that NSUN2 is imported into the matrix of mammalian mitochondria. Using three genetic models for NSUN2 inactivation-knockout mice, patient-derived fibroblasts and CRISPR/Cas9 knockout in human cells-we show that NSUN2 is necessary for the generation of m5C at positions 48, 49 and 50 of several mammalian mitochondrial tRNAs. Finally, we show that inactivation of NSUN2 does not have a profound effect on mitochondrial tRNA stability and oxidative phosphorylation in differentiated cells. We discuss the importance of the newly discovered function of NSUN2 in the context of human disease.Medical Research Council, UK [MC_UU_00015/4 to M.M.]; EMBO [ALFT 701-2013 to L.V.H.]; National Research Foundation of Korea [NRF-2019R1A2C3008463 to S.Y.L and H.W.R.]; Cancer Research UK [C13474/A18583, C6946/A14492 to E.A.M.]; Wellcome Trust [104640/Z/14/Z, 092096/Z/10/Z to E.A.M.]. Funding for open access charge: MRC

    Disruption of Microtubules Sensitizes the DNA Damage-induced Apoptosis Through Inhibiting Nuclear Factor κB (NF-κB) DNA-binding Activity

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    The massive reorganization of microtubule network involves in transcriptional regulation of several genes by controlling transcriptional factor, nuclear factor-kappa B (NF-κB) activity. The exact molecular mechanism by which microtubule rearrangement leads to NF-κB activation largely remains to be identified. However microtubule disrupting agents may possibly act in synergy or antagonism against apoptotic cell death in response to conventional chemotherapy targeting DNA damage such as adriamycin or comptothecin in cancer cells. Interestingly pretreatment of microtubule disrupting agents (colchicine, vinblastine and nocodazole) was observed to lead to paradoxical suppression of DNA damage-induced NF-κB binding activity, even though these could enhance NF-κB signaling in the absence of other stimuli. Moreover this suppressed NF-κB binding activity subsequently resulted in synergic apoptotic response, as evident by the combination with Adr and low doses of microtubule disrupting agents was able to potentiate the cytotoxic action through caspase-dependent pathway. Taken together, these results suggested that inhibition of microtubule network chemosensitizes the cancer cells to die by apoptosis through suppressing NF-κB DNA binding activity. Therefore, our study provided a possible anti-cancer mechanism of microtubule disrupting agent to overcome resistance against to chemotherapy such as DNA damaging agent

    Oncoprotein HCCR-1 expression in breast cancer is well correlated with known breast cancer prognostic factors including the HER2 overexpression, p53 mutation, and ER/PR status

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    <p>Abstract</p> <p>Background</p> <p>Oncoprotein HCCR-1 functions as a negative regulator of the p53 and contributes breast tumorigenesis. The serum HCCR-1 assay is useful in diagnosing breast cancer and mice transgenic for HCCR developed breast cancers. But it is unknown how <it>HCCR-1 </it>contributes to human breast tumorigenesis.</p> <p>Methods</p> <p>Oncogene HCCR-1 expression levels were determined in normal breast tissues, breast cancer tissues and cancer cell lines. We examined whether HCCR-1 protein expression in breast cancer is related to different biological characteristics, including ER, PR, p53 genotype, and HER2 status in 104 primary breast cancer tissues using immunohistochemical analyses.</p> <p>Results</p> <p>HCCR-1 was upregulated in breast cancer cells and tissues compared with normal breast tissues. In this study, overexpression of HCCR-1 was well correlated with known breast cancer prognostic markers including the presence of steroid receptors (ER and PR), p53 mutation and high HER2 overexpression. HCCR-1 was not detected in the ER-negative, PR-negative, p53 negative and low HER2 breast cancer tissues. These data indicate that the level of HCCR-1 in breast cancer tissues is relatively well correlated with known breast cancer factors, including the HER2 overexpression, p53 mutation, and ER/PR status.</p> <p>Conclusion</p> <p>Determination of HCCR-1 levels as options for HER2 testing is promising although it needs further evaluation.</p
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