34 results on '"Shu, Su"'
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2. Copper(0)-Catalyzed Reductive Coupling of Disulfurating Reagents and (Hetero)aryl/Alkyl Halides.
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Chen W, Xu J, Rao W, Shen SS, Yang ZY, Ackermann L, and Wang SY
- Abstract
Herein, we reported a copper(0)-catalyzed reductive coupling of disulfurating reagents and (hetero)aryl/alkyl halides. Copper(0) can be directly inserted into tetrasulfide and then undergoes reductive coupling with (hetero)aryl Iodides to construct disulfide. The method features the unprecedented use of copper(0)-catalyzed disulfurating reagents (tetrasulfides) in cross-coupling chemistry and is convenient with broad substrate scopes, even applicable to different halogenated hydrocarbons. It is worth noting that the methodology is practical with the late-stage modification of bioactive scaffolds of pharmaceuticals. In the meantime, the synthesis of disulfides is successfully achieved on a gram scale, indicating the approach is highly valuable.
- Published
- 2024
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3. Regioselective 1,4-/1,3-Difunctionalization of 1,3-Enynes with Selenosulfonates in Water.
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Deng HH, Tian SY, Han JH, Liu XY, Rao W, Shen SS, Sheng D, Yang ZY, and Wang SY
- Abstract
1,4-/1,3-Regioselective bifunctionalization of 1,3-enynes with selenosulfonates in water under catalyst-free conditions for the construction of sulfonyl allene and 1,3-disulfonyl-conjugated dienes respectively have been developed. The reactions feature mild reaction conditions in aqueous solution and remarkable regioselectivity controlled by substrates.
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- 2024
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4. Visible Light-Catalyzed Reactions of Polysulfide (DBSPS) with Aryldiazonium.
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Tang LJ, Zhu WC, Deng HH, Jiang YF, Liu XY, Rao W, Shen SS, Song P, and Wang SY
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A visible light-catalyzed radical coupling reaction of polysulfide reagents with aryldiazonium was developed, which gave thiosulfonates under mild conditions. In this reaction, the thiosulfonates were isolated in good yields with a broad tolerance to functional groups. And the synthesis of diaryl monosulfides were achieved through a step-by-step reaction of two molecular aryldiazonium with DBSPS, where the sulfur source was provided by DBSPS. It was worth noting that the reaction of this monosulfides could also be achieved by a one pot two-step process. The described polysulfide reagents were able to produce three new radicals: sulfonyl radicals, sulfur-sulfonyl radicals and sulfur-sulfur-sulfonyl radicals., (© 2024 Wiley-VCH GmbH.)
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- 2024
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5. Copper-Catalyzed Chemoselective Coupling of N -Dithiophthalimides and Alkyl Halides: Synthesis of Unsymmetrical Disulfides and Sulfides.
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Li B, Liu BX, Rao W, Shen SS, Sheng D, and Wang SY
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In this paper, we report an unprecedented copper-catalyzed disulfides or sulfides coupling reaction involving unactivated alkyl halides and N -dithiophthalimides. This reaction can be conducted under mild conditions using low-cost metal catalysts and exhibits high chemical selectivity and functional group compatibility, enabling the efficient assembly of various sulfides and disulfides.
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- 2024
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6. Regioselective Thiol-yne Reaction of Thiol with ((Methyl-d 3 )sulfonyl)ethyne: Synthesis of (2-((Methyl-d 3 )sulfonyl)vinyl)sulfides.
- Author
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Cao JM, Liu XY, Rao W, Shen SS, Sheng D, and Wang SY
- Abstract
Herein, we have developed a new method for the synthesis of ((methyl-d
3 )sulfonyl)ethyne, which is cost-effective and environmentally friendly and can be synthesized at the gram level. As an ideal thiol-yne reagent, it can be reacted with various types of thiols to afford ( Z )- and ( E )-type vinyl sulfides under different conditions with high selectivity. In addition, it can complete the conformational transition from Z- to E-type products under suitable conditions, and can also carry out further derivatization smoothly. The deuterium content of all products was greater than 99%. The preliminary mechanistic studies support the visible light-mediated radical course, and herein provide a novel and efficient synthetic strategy for the direct introduction of deuterated methyl groups, enriching the methods for the construction of C-S bond-containing compounds.- Published
- 2024
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7. Simultaneous Preparation of Sulfides/Selenides and Sulfones via Synergistic Nickel-Catalyzed Reductive Coupling and S N 2 Reaction.
- Author
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Cao JM, Zhu WC, Liu XY, Rao W, Shen SS, Sheng DP, and Wang SY
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Sulfone compounds and thioether compounds are two highly valuable classes of compounds, but it is challenging to prepare sulfone and thioether compounds simultaneously and efficiently. Here we report that sulfides/selenides and sulfones can be obtained simultaneously using allyl bromide/benzyl bromide-activated alkyl bromides and thiosulfonates/selenosulfonates using a nickel-catalyzed reductive coupling and S
N 2 synergistic strategy, which is characterized by excellent atom and step economy, mild reaction conditions, broad functional group compatibility, and excellent yields.- Published
- 2023
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8. Computed tomography-determined skeletal muscle density predicts 3-year mortality in initial-dialysis patients in China.
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Sheng MJ, Cao JY, Hou SM, Li M, Wang Y, Fang Q, Miao AF, Yang M, Liu SS, Hu CH, Liu CL, Wang SY, Zheng J, Xiao JJ, Zhang XL, Liu H, Liu BC, and Wang B
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- Male, Female, Humans, Retrospective Studies, Prognosis, Tomography, X-Ray Computed methods, Death, Renal Dialysis, Muscle, Skeletal diagnostic imaging
- Abstract
Background: Skeletal muscle mass and quality assessed by computed tomography (CT) images of the third lumbar vertebra (L3) level have been established as risk factors for poor clinical outcomes in several illnesses, but the relevance for dialysis patients is unclear. A few studies have suggested a correlation between CT-determined skeletal muscle mass and quality at the first lumbar vertebra (L1) level and adverse outcomes. Generally, chest CT does not reach beyond L1. We aimed to determine whether opportunistic CT scan (chest CT)-determined skeletal muscle mass and quality at L1 are associated with mortality in initial-dialysis patients., Methods: This 3-year multicentric retrospective study included initial-dialysis patients from four centres between 2014 and 2017 in China. Unenhanced CT images of the L1 and L3 levels were obtained to assess skeletal muscle mass [by skeletal muscle index, (SMI), cm
2 /m2 ] and quality [by skeletal muscle density (SMD), HU]. Skeletal muscle measures at L1 were compared with those at L3. The sex-specific optimal cutoff values of L1 SMI and L1 SMD were determined in relation to all-cause mortality. The outcomes were all-cause death and cardiac death. Cox regression models were applied to investigate the risk factors for death., Results: A total of 485 patients were enrolled, of whom 257 had both L1 and L3 images. Pearson's correlation coefficient between L1 and L3 SMI was 0.84 (P < 0.001), and that between L1 and L3 SMD was 0.90 (P < 0.001). No significant association between L1 SMI and mortality was observed (P > 0.05). Low L1 SMD (n = 280, 57.73%) was diagnosed based on the optimal cutoff value (<39.56 HU for males and <33.06 HU for females). Multivariate regression analysis revealed that the low L1 SMD group had higher risks of all-cause death (hazard ratio 1.80; 95% confidence interval 1.05-3.11, P = 0.034) and cardiac death (hazard ratio 3.74; 95% confidence interval 1.43-9.79, P = 0.007)., Conclusions: In initial-dialysis patients, there is high agreement between the L1 and L3 measures for SMI and SMD. Low SMD measured at L1, but not low SMI, is an independent predictor of both all-cause death and cardiac death., (© 2023 The Authors. Journal of Cachexia, Sarcopenia and Muscle published by Wiley Periodicals LLC.)- Published
- 2023
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9. Nickel-Catalyzed Acid Chlorides with Tetrasulfides for the Synthesis of Thioesters and Acyl Disulfides.
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Chen W, Sheng D, Jiang YF, Zhu WC, Rao W, Shen SS, Yang ZY, and Wang SY
- Abstract
Herein, we report a novel method for the synthesis of thioesters and acyl disulfides via nickel-catalyzed reductive cross-electrophile coupling of acid chlorides with tetrasulfides. This approach for the synthesis of thioesters and acyl disulfides is convenient and practical under mild reaction conditions, relying on easy availability. In addition, a wide range of thioesters and acyl disulfides were obtained in medium to good yields with good functional group tolerance. Moreover, thioesters and acyl disulfides can also be prepared at the gram scale, indicating that they have certain potential for industrial application.
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- 2023
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10. Synthesis of 1,3-Dibenzenesulfonylpolysulfane (DBSPS) and Its Application in the Preparation of Aryl Thiosulfonates from Boronic Acids.
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Jiang YF, Zhu WC, Liu XY, Tian SY, Han JH, Rao W, Shen SS, Sheng D, and Wang SY
- Abstract
Herein, we provide a novel method for the synthesis of 1,3-dibenzenesulfonylpolysulfane (DBSPS), which further reacts with boronic acids to afford thiosulfonates. Commercially available boron compounds greatly expanded the range of thiosulfonates. Experimental and theoretical mechanistic investigations suggested that DBSPS could provide both thiosulfone fragments and dithiosulfone fragments, but the generated aryl dithiosulfonates were unstable and decomposed into thiosulfonates.
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- 2023
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11. Photoinduced Construction of Thieno[3,4- c ]quinolin-4(5 H )-ones/Selenopheno[3,4- c ]quinolin-4(5 H )-ones Using Diphenyl Disulfide or Diphenyl Diselenide as Sulfur or Selenium Sources.
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Tian SY, Ai JJ, Han JH, Rao W, Shen SS, Sheng D, and Wang SY
- Abstract
A photocatalytic synthesis of thieno[3,4- c ]quinolin-4(5 H )-ones/selenopheno[3,4- c ]quinolin-4(5 H )-ones using diphenyl disulfide or diphenyl diselenide as sulfur or selenium sources was developed. Two C-S/Se bonds and one C-C bond were constructed simultaneously without transition metals and other additives.
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- 2023
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12. Elevated serum FGF21 is an independent predictor for adverse events in hemodialysis patients from two large centers: a prospective cohort study.
- Author
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Li M, Jiang LQ, Zhang MY, Liu SS, Sawh RR, Zheng J, Yan Y, Hou SM, Lu KQ, Thorne O, Liu BC, Qian Q, Wu YF, Yang M, and Wang B
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- Humans, Prospective Studies, East Asian People, Fibroblast Growth Factors blood, Renal Dialysis adverse effects
- Abstract
Introduction: We explored the relationship and the predictive value of serum fibroblast growth factor 21 (FGF21) with all-cause mortality, major adverse cardiovascular events (MACEs) and pneumonia in hemodialysis (HD) patients. Methods: A total of 388 Chinese HD patients from two HD centers were finally enrolled in this prospective cohort study (registration number: ChiCTR 1900028249) between January 2018 and December 2018. Serum FGF21 was detected. Patients were followed up with a median period of 47 months to record the MACEs and pneumonia until death or 31 December 2022. Results: The incidence of all-cause mortality, MACEs and pneumonia in HD patients were 20.6%, 29.6%, and 34.8%, respectively. The optimal cutoffs for FGF21 to predict all-cause mortality, MACEs and pneumonia were 437.57 pg/mL, 216.99 pg/mL and 112.79 pg/mL. Multivariate Cox regression analyses showed that FGF21, as a categorical variable, was an independent predictor for all-cause mortality, MACEs and pneumonia (HR, 3.357, 95% CI, 2.128-5.295, p < 0.001; HR, 1.575, 95% CI, 1.046-2.371, p = 0.029; HR, 1.784; 95% CI, 1.124-2.830; p = 0.014, respectively). The survival nomogram, MACEs-free survival nomogram and pneumonia-free survival nomogram based on FGF21 constructed for individualized assessment of HD patients had a high C-index with 0.841, 0.706 and 0.734. Conclusion: Higher serum FGF21 is an independent predictor of all-cause mortality, MACEs and pneumonia in HD patients.
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- 2023
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13. Cu-catalyzed efficient construction of S (Se)-containing functional organosilicon compounds.
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Wang F, Chen Y, Rao W, Shen SS, and Wang SY
- Abstract
A Cu-catalyzed cascade reaction of four-membered silacyclobutanes (SCBs) and thiosulfonates to construct S (Se)-containing organosilicon compounds was developed. The protocol shows a wide range of substrate scope, high functional group compatibility and mild reaction conditions. New C-S (Se) and Si-O bonds were constructed in one step.
- Published
- 2022
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14. Informed MEG/EEG source imaging reveals the locations of interictal spikes missed by SEEG.
- Author
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Shu S, Luo S, Cao M, Xu K, Qin L, Zheng L, Xu J, Wang X, and Gao JH
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- Brain diagnostic imaging, Brain surgery, Brain Mapping methods, Electroencephalography methods, Humans, Magnetic Resonance Imaging, Epilepsy diagnostic imaging, Epilepsy surgery, Magnetoencephalography methods
- Abstract
Determining the accurate locations of interictal spikes has been fundamental in the presurgical evaluation of epilepsy surgery. Stereo-electroencephalography (SEEG) is able to directly record cortical activity and localize interictal spikes. However, the main caveat of SEEG techniques is that they have limited spatial sampling (covering <5% of the whole brain), which may lead to missed spikes originating from brain regions that were not covered by SEEG. To address this problem, we propose a SEEG-informed minimum-norm estimates (SIMNE) method by combining SEEG with magnetoencephalography (MEG) or EEG. Specifically, the spike locations determined by SEEG offer as a priori information to guide MEG source reconstruction. Both computer simulations and experiments using data from five epilepsy patients were conducted to evaluate the performance of SIMNE. Our results demonstrate that SIMNE generates more accurate source estimation than a traditional minimum-norm estimates method and reveals the locations of spikes missed by SEEG, which would improve presurgical evaluation of the epileptogenic zone., Competing Interests: Declaration of Competing Interest The authors have no financial or competing interests to declare., (Copyright © 2022. Published by Elsevier Inc.)
- Published
- 2022
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15. Presynaptic HCN channels constrain GABAergic synaptic transmission in pyramidal cells of the medial prefrontal cortex.
- Author
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Cai W, Liu SS, Li BM, and Zhang XH
- Subjects
- Animals, Interneurons physiology, Prefrontal Cortex, Rats, Synaptic Transmission, Hyperpolarization-Activated Cyclic Nucleotide-Gated Channels, Pyramidal Cells
- Abstract
Hyperpolarization-activated cyclic nucleotide-gated (HCN) channels are widely expressed in neurons in the central nervous system. It has been documented that HCN channels regulate the intrinsic excitability of pyramidal cells in the medial prefrontal cortex (mPFC) of rodents. Here, we report that HCN channels limited GABAergic transmission onto pyramidal cells in rat mPFC. The pharmacological blockade of HCN channels resulted in a significant increase in the frequency of both spontaneous and miniature inhibitory postsynaptic currents (IPSCs) in mPFC pyramidal cells, whereas potentiation of HCN channels reversely decreases the frequency of mIPSCs. Furthermore, such facilitation effect on mIPSC frequency required presynaptic Ca2+ influx. Immunofluorescence staining showed that HCN channels expressed in presynaptic GABAergic terminals, as well as in both soma and neurite of parvalbumin-expressing (PV-expressing) basket cells in mPFC. The present results indicate that HCN channels in GABAergic interneurons, most likely PV-expressing basket cells, constrain inhibitory control over layer 5-6 pyramidal cells by restricting presynaptic Ca2+ entry., Competing Interests: Competing interests The authors declare no competing or financial interests., (© 2022. Published by The Company of Biologists Ltd.)
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- 2022
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16. Effects of mild hypoxia on oxygen extraction fraction responses to brain stimulation.
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Yin Y, Shu S, Qin L, Shan Y, Gao JH, and Lu J
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- Adult, Female, Humans, Male, Young Adult, Brain physiopathology, Cell Hypoxia physiology, Cerebrovascular Circulation physiology, Oxygen metabolism
- Abstract
Characterizing the effect of limited oxygen availability on brain metabolism during brain activation is an essential step towards a better understanding of brain homeostasis and has obvious clinical implications. However, how the cerebral oxygen extraction fraction (OEF) depends on oxygen availability during brain activation remains unclear, which is mostly attributable to the scarcity and safety of measurement techniques. Recently, a magnetic resonance imaging (MRI) method that enables noninvasive and dynamic measurement of the OEF has been developed and confirmed to be applicable to functional MRI studies. Using this novel method, the present study investigated the motor-evoked OEF response in both normoxia (21% O
2 ) and hypoxia (12% O2 ). Our results showed that OEF activation decreased in the brain areas involved in motor task execution. Decreases in the motor-evoked OEF response were greater under hypoxia (-21.7% ± 5.5%) than under normoxia (-11.8% ± 3.7%) and showed a substantial decrease as a function of arterial oxygen saturation. These findings suggest a different relationship between oxygen delivery and consumption during hypoxia compared to normoxia. This methodology may provide a new perspective on the effects of mild hypoxia on brain function.- Published
- 2021
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17. A Heteromodal Word-Meaning Binding Site in the Visual Word Form Area under Top-Down Frontoparietal Control.
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Qin L, Lyu B, Shu S, Yin Y, Wang X, Ge J, Siok WT, and Gao JH
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- Brain Mapping, Cognition physiology, Female, Frontal Lobe diagnostic imaging, Humans, Language, Language Tests, Magnetic Resonance Imaging, Male, Memory physiology, Neural Pathways physiology, Occipital Lobe physiology, Parietal Lobe diagnostic imaging, Speech Perception physiology, Speech Production Measurement, Young Adult, Comprehension physiology, Frontal Lobe physiology, Parietal Lobe physiology, Reading
- Abstract
The integral capacity of human language together with semantic memory drives the linkage of words and their meaning, which theoretically is subject to cognitive control. However, it remains unknown whether, across different language modalities and input/output formats, there is a shared system in the human brain for word-meaning binding and how this system interacts with cognitive control. Here, we conducted a functional magnetic resonance imaging experiment based on a large cohort of subjects (50 females, 50 males) to comprehensively measure the brain responses evoked by semantic processing in spoken and written word comprehension and production tasks (listening, speaking, reading, and writing). We found that heteromodal word input and output tasks involved distributed brain regions within a frontal-parietal-temporal network and focally coactivated the anterior lateral visual word form area (VWFA), which is located in the basal occipitotemporal area. Directed connectivity analysis revealed that the VWFA was invariably under significant top-down modulation of the frontoparietal control network and interacts with regions related to attention and semantic representation. This study reveals that the VWFA is a key site subserving general semantic processes linking words and meaning, challenging the predominant emphasis on this area's specific role in reading or more general visual processes. Our findings also suggest that the dynamics between semantic memory and cognitive control mechanisms during word processing are largely independent of the modalities of input or output. SIGNIFICANCE STATEMENT Binding words and their meaning into a coherent whole during retrieval requires accessing semantic memory and cognitive control, allowing our thoughts to be expressed and comprehended through mind-external tokens in multiple modalities, such as written or spoken forms. However, it is still unknown whether multimodal language comprehension and production share a common word-meaning binding system in human brains and how this system is connected to a cognitive control mechanism. By systematically measuring brain activity evoked by spoken and written verbal input and output tasks tagging word-meaning binding processes, we demonstrate a general word-meaning binding site within the visual word form area (VWFA) and how this site is modulated by the frontal-parietal control network., (Copyright © 2021 the authors.)
- Published
- 2021
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18. [Paclitaxel liposome for the treatment of castration-resistant prostate cancer].
- Author
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Zhu SS, Zhang FY, Xue S, and Sun XQ
- Subjects
- Aged, Bone Neoplasms secondary, China, Humans, Male, Middle Aged, Prostate-Specific Antigen blood, Prostatic Neoplasms, Castration-Resistant pathology, Retrospective Studies, Survival Rate, Treatment Outcome, Liposomes administration & dosage, Paclitaxel administration & dosage, Prostatic Neoplasms, Castration-Resistant drug therapy
- Abstract
Objective: To investigate the effect and safety of the 3-week paclitaxel liposome protocol in the treatment of castration-resistant prostate cancer (CRPC)., Methods: This retrospective study included 40 cases of CRPC treated by the 3-week paclitaxel liposome protocol from February 2014 to February 2019, which involved intravenous injection of 10 mg dexamethasone in 100 ml normal saline on the first day and that of metoclopramide and panxi tora azole on the second day, followed by about 3 hours of intravenous drip of paclitaxel liposome at 135 mg/m2 for a course of 3 weeks. During the follow-up period, the patients received detection of the serum PSA level before treatment and chest x-ray and whole-body bone scan every six months. After two courses of treatment, the patients were observed for the changes in the serum PSA level, relief of bone pain, quality of survival, overall survival rate, overall survival time and toxic reactions. The protocol was continued unless the patient underwent progression, refused for unacceptable toxicity, or died., Results: The patients were aged 59 to 79 (mean 68.80±5.67) years old, with the serum PSA level of (28.05 ± 3.22) μg/L at the baseline and (4.12 ± 0.23) μg/L after treatment. Thirty-eight of the patients were followed up for 3 to 33 (mean 12.2) months. PSA-based evaluation showed therapeutic effectiveness in 14 cases (35%), stable condition in 21 (52.5 %) and progression in 5 (12.5 %). Of the 18 patients with bone metastasis and pain, 16 (88.9 %) experienced relief of the symptoms and reduced the use of painkillers, with the bone pain scores of 5.20 ± 1.22 vs 2.79 ± 0.57 before and after treatment. By the end of the follow-up, the overall survival rate was 55.0% (22/40) and the median survival time was 17 months (95% CI: 13.4-24.6). During the treatment, no obvious adverse reactions were observed except for anemia in 1 case and hair loss in another., Conclusions: For the treatment of CRPC in China, the 3-week paclitaxel liposome protocol has the advantages of desirable safety, low toxicity, acceptable drug tolerance and improved quality of survival, but its curative effect needs to be verified with more randomized clinical trials with larger samples and longer follow-ups.
- Published
- 2020
19. Cortical electrophysiological evidence for individual-specific temporal organization of brain functional networks.
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Shu S, Qin L, Yin Y, Han M, Cui W, and Gao JH
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- Adult, Cerebral Cortex diagnostic imaging, Default Mode Network diagnostic imaging, Female, Humans, Male, Markov Chains, Nerve Net diagnostic imaging, Time Factors, Young Adult, Cerebral Cortex physiology, Connectome methods, Default Mode Network physiology, Magnetoencephalography methods, Nerve Net physiology
- Abstract
The human brain has been demonstrated to rapidly and continuously form and dissolve networks on a subsecond timescale, offering effective and essential substrates for cognitive processes. Understanding how the dynamic organization of brain functional networks on a subsecond level varies across individuals is, therefore, of great interest for personalized neuroscience. However, it remains unclear whether features of such rapid network organization are reliably unique and stable in single subjects and, therefore, can be used in characterizing individual networks. Here, we used two sets of 5-min magnetoencephalography (MEG) resting data from 39 healthy subjects over two consecutive days and modeled the spontaneous brain activity as recurring networks fast shifting between each other in a coordinated manner. MEG cortical maps were obtained through source reconstruction using the beamformer method and subjects' temporal structure of recurring networks was obtained via the Hidden Markov Model. Individual organization of dynamic brain activity was quantified with the features of the network-switching pattern (i.e., transition probability and mean interval time) and the time-allocation mode (i.e., fractional occupancy and mean lifetime). Using these features, we were able to identify subjects from the group with significant accuracies (~40% on average in 0.5-48 Hz). Notably, the default mode network displayed a distinguishable pattern, being the least frequently visited network with the longest duration for each visit. Together, we provide initial evidence suggesting that the rapid dynamic temporal organization of brain networks achieved in electrophysiology is intrinsic and subject specific., (© 2020 The Authors. Human Brain Mapping published by Wiley Periodicals, Inc.)
- Published
- 2020
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20. Spatiotemporal dynamics of predictive brain mechanisms during speech processing: an MEG study.
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Liu Z, Shu S, Lu L, Ge J, and Gao JH
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- Adult, Brain Mapping, Female, Humans, Magnetoencephalography, Male, Prefrontal Cortex diagnostic imaging, Semantics, Prefrontal Cortex physiology, Speech Perception
- Abstract
Rapid and efficient speech processing benefits from the prediction derived from prior expectations based on the identification of individual words. It is known that speech processing is carried out within a distributed frontotemporal network. However, the spatiotemporal causal dynamics of predictive brain mechanisms in sound-to-meaning mapping within this network remain unclear. Using magnetoencephalography, we adopted a semantic anomaly paradigm which consists of expected, unexpected and time-reversed Mandarin Chinese speech, and localized the effects of violated expectation in frontotemporal brain regions, the sensorimotor cortex and the supramarginal gyrus from 250 ms relative to the target words. By further investigating the causal cortical dynamics, we provided the description of the causal dynamic network within the framework of the dual stream model, and highlighted the importance of the connections within the ventral pathway, the top-down modulation from the left inferior frontal gyrus and the cross-stream integration during the speech processing of violated expectation., Competing Interests: Declaration of Competing Interest: The authors declared that there is no conflict of interest., (Copyright © 2020 Elsevier Inc. All rights reserved.)
- Published
- 2020
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21. Protective effect of dabrafenib on renal ischemia-reperfusion injury in vivo and in vitro.
- Author
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Liu SS, Chen YY, Wang SX, and Yu Q
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- Animals, Apoptosis drug effects, Cytokines metabolism, Down-Regulation drug effects, Humans, Imidazoles pharmacology, Inflammation pathology, Kidney drug effects, Male, Mice, Inbred C57BL, Oximes pharmacology, Protective Agents pharmacology, Signal Transduction drug effects, Imidazoles therapeutic use, Kidney blood supply, Kidney pathology, Oximes therapeutic use, Protective Agents therapeutic use, Reperfusion Injury drug therapy
- Abstract
Aims: Ischemia-reperfusion injury (IRI) is a major cause of acute kidney injury (AKI), which can lead to poor outcome and increased risk of mortality. Dabrafenib (DAB) is an approved cancer treatment. Little is known about the effect of DAB in prevention or treatment of renal IRI., Methods: For in vivo experiments, C57BL/6 mice were divided into four groups: sham (no IRI, no DAB), IRI, DAB, and DAB + IRI. IRI was induced by clamping of bilateral renal pedicles for 30 min. For in vitro experiments, HK-2 cells were used to establish the hypoxia/reoxygenation (H/R) injury model, with four groups: control (no H/R, no DAB), H/R, DAB, and DAB + H/R. Renal function and renal histological changes were recorded. Expression of NGAL and KIM-1 proteins and mRNAs were determined by western blotting and qRT-PCR; secretion of inflammatory cytokines (IL-6 and TNF- α) was determined by qRT-PCR; Cell death was determined using the TUNEL assay, measurement of cleaved caspase-3, and flow cytometry. Necroptosis-related proteins were determined by western blotting., Results: In mice, DAB pretreatment improved renal function and also reduced histological injury, inflammation, cell death, and expression of necroptosis-associated proteins. In HK-2 cells, DAB significantly decreased the levels of NGAL and KIM-1, inflammatory cytokines, cell death, and necroptosis-related proteins., Conclusion: Our in vitro and in vivo experiments indicated that DAB appears to alleviate renal IRI by suppressing cell death and inhibiting inflammatory responses. DAB has potential use for the clinical prevention and treatment of AKI-induced IRI., (Copyright © 2019 Elsevier Inc. All rights reserved.)
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- 2020
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22. Highly efficient generation of 0.2 mJ terahertz pulses in lithium niobate at room temperature with sub-50 fs chirped Ti:sapphire laser pulses.
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Wu XJ, Ma JL, Zhang BL, Chai SS, Fang ZJ, Xia CY, Kong DY, Wang JG, Liu H, Zhu CQ, Wang X, Ruan CJ, and Li YT
- Abstract
We demonstrate generation of 0.2 mJ terahertz (THz) pulses in lithium niobate driven by Ti:sapphire laser pulses at room temperature. Employing tilted pulse front technique, the 800 nm-to-THz energy conversion efficiency has been optimized to 0.3% through chirping the sub-50 fs pump laser pulses to overcome multi-photon absorption and to extend effective interaction length for phase matching. Our approach paves the way for mJ-level THz generation via optical rectification using existing Ti:sapphire laser systems which can deliver Joule-level pulse energy with sub-50 fs pulse duration.
- Published
- 2018
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23. Psychological distress among re-education through labour camp detainees in Guangxi Autonomous Region, China.
- Author
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Yap L, Shu S, Zhang L, Liu W, Chen Y, Wu Z, Li J, Wand H, Donovan B, and Butler T
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- Adult, China, Cross-Sectional Studies, Female, Health Surveys, Humans, Male, Middle Aged, Prisoners statistics & numerical data, Self Report, Sexually Transmitted Diseases epidemiology, Stress, Psychological complications, Substance-Related Disorders complications, Substance-Related Disorders epidemiology, Young Adult, Prisoners psychology, Stress, Psychological epidemiology
- Abstract
Background: There is currently no information about the prevalence of, and factors contributing to psychological distress experienced by re-education through labour camp detainees in China., Methods: A cross-sectional face-to-face survey was conducted in three labour camps in Guangxi, China. The questionnaire covered socio-demographic characteristics; sexually transmissible infections (STIs); drug use; psychological distress (K-10); and health service usage and access inside the labour camps. K-10 scores were categorised as ≤30 (low to moderate distress) and >30 or more (highly distressed). Univariate and multivariate logistic regression models identified factors independently associated with high K-10 scores for men and women separately., Results: In total, 755 detainees, 576 (76%) men and 179 (24%) women, participated in the health survey. The study found 11.6% men versus 11.2% women detainees experienced high psychological distress, but no significant gender differences were observed (p> 0.05). Multivariate logistic regression showed that multiple physical health problems were significantly associated with high psychological distress among men., Conclusion: Drug treatment and forensic mental health services need to be established in detention centres in China to treat more than 10% of detainees with drug use and mental health disorders.
- Published
- 2017
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24. Surface expression of hippocampal NMDA GluN2B receptors regulated by fear conditioning determines its contribution to memory consolidation in adult rats.
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Sun YY, Cai W, Yu J, Liu SS, Zhuo M, Li BM, and Zhang XH
- Subjects
- Animals, Conditioning, Classical, Hippocampus metabolism, Hippocampus physiology, Rats, Synapses metabolism, Synapses physiology, Cell Membrane metabolism, Fear psychology, Memory Consolidation, Receptors, N-Methyl-D-Aspartate metabolism
- Abstract
The number and subtype composition of N-methyl-d-aspartate receptor (NMDAR) at synapses determines their functional properties and role in learning and memory. Genetically increased or decreased amount of GluN2B affects hippocampus-dependent memory in the adult brain. But in some experimental conditions (e.g., memory elicited by a single conditioning trial (1 CS-US)), GluN2B is not a necessary factor, which indicates that the precise role of GluN2B in memory formation requires further exploration. Here, we examined the role of GluN2B in the consolidation of fear memory using two training paradigms. We found that GluN2B was only required for the consolidation of memory elicited by five conditioning trials (5 CS-US), not by 1 CS-US. Strikingly, the expression of membrane GluN2B in CA1was training-strength-dependently increased after conditioning, and that the amount of membrane GluN2B determined its involvement in memory consolidation. Additionally, we demonstrated the increases in the activities of cAMP, ERK, and CREB in the CA1 after conditioning, as well as the enhanced intrinsic excitability and synaptic efficacy in CA1 neurons. Up-regulation of membrane GluN2B contributed to these enhancements. These studies uncover a novel mechanism for the involvement of GluN2B in memory consolidation by its accumulation at the cell surface in response to behavioral training.
- Published
- 2016
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25. A facile and efficient transposon mutagenesis method for generation of multi-codon deletions in protein sequences.
- Author
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Liu SS, Wei X, Ji Q, Xin X, Jiang B, and Liu J
- Subjects
- Amino Acid Sequence, Base Sequence, Fluorescence, Polymerase Chain Reaction, Restriction Mapping, Codon genetics, DNA Transposable Elements genetics, Green Fluorescent Proteins genetics, Mutagenesis, Insertional methods, Sequence Deletion genetics
- Abstract
Substitutions, insertions and deletions are all important mutation events in natural and laboratory protein evolution. However, protein engineering using insertions and deletions (indels) is hindered by the lack of a convenient mutagenesis method. Here, we describe a general transposon mutagenesis method that allows for removal of up to five consecutive in-frame codons from a random position of a target protein. This method, referred to as codon deletion mutagenesis (CDM), relies on an engineered Mu transposon that carries asymmetric terminal sequences flanking the MuA transposase recognition sites. CDM requires minimal DNA manipulations, and can generate multi-codon deletions with high efficiency (>90%). As a proof of principle, we constructed five libraries of green fluorescent protein (GFP) containing one to five random codon deletions, respectively. Several variants with multi-codon deletions remained fluorescent, none of which could be easily identified using traditional mutagenesis method. CDM provides a facile and efficient approach to sampling a protein sequence with multi-codon deletions. It will not only facilitate our understanding of the effects of amino acid deletions on protein function but also expedite protein engineering using deletion mutagenesis., (Copyright © 2016 Elsevier B.V. All rights reserved.)
- Published
- 2016
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26. Structural plasticity of green fluorescent protein to amino acid deletions and fluorescence rescue by folding-enhancing mutations.
- Author
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Liu SS, Wei X, Dong X, Xu L, Liu J, and Jiang B
- Subjects
- DNA Transposable Elements genetics, Kinetics, Models, Molecular, Mutagenesis, Protein Refolding, Protein Structure, Secondary, Spectrometry, Fluorescence, Green Fluorescent Proteins chemistry, Green Fluorescent Proteins genetics, Protein Folding, Sequence Deletion
- Abstract
Background: Green fluorescent protein (GFP) and its derivative fluorescent proteins (FPs) are among the most commonly used reporter systems for studying gene expression and protein interaction in biomedical research. Most commercially available FPs have been optimized for their oligomerization state to prevent potential structural constraints that may interfere with the native function of fused proteins. Other approach to reducing structural constraints may include minimizing the structure of GFPs. Previous studies in an enhanced GFP variant (EGFP) identified a series of deletions that can retain GFP fluorescence. In this study, we interrogated the structural plasticity of a UV-optimized GFP variant (GFP(UV)) to amino acid deletions, characterized the effects of deletions and explored the feasibility of rescuing the fluorescence of deletion mutants using folding-enhancing mutations., Methods: Transposon mutagenesis was used to screen amino acid deletions in GFP that led to fluorescent and nonfluorescent phenotypes. The fluorescent GFP mutants were characterized for their whole-cell fluorescence and fraction soluble. Fluorescent GFP mutants with internal deletions were purified and characterized for their spectral and folding properties. Folding-ehancing mutations were introduced to deletion mutants to rescue their compromised fluorescence., Results: We identified twelve amino acid deletions that can retain the fluorescence of GFP(UV). Seven of these deletions are either at the N- or C- terminus, while the other five are located at internal helices or strands. Further analysis suggested that the five internal deletions diminished the efficiency of protein folding and chromophore maturation. Protein expression under hypothermic condition or incorporation of folding-enhancing mutations could rescue the compromised fluorescence of deletion mutants. In addition, we generated dual deletion mutants that can retain GFP fluorescence., Conclusion: Our results suggested that a "size-minimized" GFP may be developed by iterative incorporation of amino acid deletions, followed by fluorescence rescue with folding-enhancing mutations.
- Published
- 2015
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27. Intraoral Digital Impression Technique: A Review.
- Author
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Ting-Shu S and Jian S
- Subjects
- Humans, Computer-Aided Design, Dental Impression Technique
- Abstract
With the techniques of computer-aided design and computer-aided manufacturing (CAD/CAM) being applied in the field of prosthodontics, a concept of intraoral digital impressions was put forward in the early 1980s. It has drawn comprehensive attention from dentists and has been used for dental prosthesis fabrication in a number of cases. This new digital impression technique is expected to bring about absolute digitization to the mode of prosthodontics. A few published articles have indicated that dental prostheses fabricated from intraoral digital impressions have exhibited remarkable advantages over those from conventional impressions in several respects. The present review discusses intraoral digital impression techniques in terms of the following aspects: (1) categories and principles of intraoral digital impression devices currently available; (2) operating characteristics of the devices; and (3) comparison of the manipulation, accuracy, and repeatability between intraoral digital impression and conventional impression., (© 2014 by the American College of Prosthodontists.)
- Published
- 2015
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28. Signaling mechanism underlying α2A -adrenergic suppression of excitatory synaptic transmission in the medial prefrontal cortex of rats.
- Author
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Yi F, Liu SS, Luo F, Zhang XH, and Li BM
- Subjects
- Adrenergic alpha-2 Receptor Agonists pharmacology, Animals, Female, Guanfacine pharmacology, In Vitro Techniques, Male, Prefrontal Cortex metabolism, Pyramidal Cells physiology, Rats, Rats, Sprague-Dawley, Excitatory Postsynaptic Potentials drug effects, Neural Inhibition drug effects, Prefrontal Cortex physiology, Receptors, Adrenergic, alpha-2 metabolism, Signal Transduction
- Abstract
Stimulation of α2A -adrenoceptors (ARs) in the prefrontal cortex (PFC) produces a beneficial effect on cognitive functions such as working memory. A previous study in our laboratory showed that α2A -AR stimulation suppresses excitatory synaptic transmission in layer V-VI pyramidal cells of the rat medial PFC (mPFC). However, the intracellular mechanism underlying the α2A -AR suppression remains unclear. In the present study, we recorded evoked excitatory postsynaptic current (eEPSC) in layer V-VI pyramidal cells of the mPFC, using whole-cell patch-clamp recording. We found that the α2A -AR agonist guanfacine significantly suppresses eEPSC in mPFC pyramidal cells. The α2A -AR inhibition is mediated by the Gi-cAMP-PKA-PP1-CaMKII-AMPAR signaling pathway, as such inhibition no longer exists when each step of this pathway is blocked with NF023, Rp-cAMP, PKI5-24 or H89, tautomycin, and KN-62 or KN-93, respectively., (© 2013 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.)
- Published
- 2013
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29. Delay-dependent impairment of spatial working memory with inhibition of NR2B-containing NMDA receptors in hippocampal CA1 region of rats.
- Author
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Zhang XH, Liu SS, Yi F, Zhuo M, and Li BM
- Subjects
- Animals, CA1 Region, Hippocampal pathology, Male, Maze Learning, Mice, Rats, Rats, Sprague-Dawley, Receptors, N-Methyl-D-Aspartate metabolism, Time Factors, CA1 Region, Hippocampal physiopathology, Memory, Short-Term physiology, Receptors, N-Methyl-D-Aspartate antagonists & inhibitors
- Abstract
Hippocampal N-methyl-D-aspartate receptor (NMDAR) is required for spatial working memory. Although evidence from genetic manipulation mice suggests an important role of hippocampal NMDAR NR2B subunits (NR2B-NMDARs) in spatial working memory, it remains unclear whether or not the requirement of hippocampal NR2B-NMDARs for spatial working memory depends on the time of spatial information maintained. Here, we investigate the contribution of hippocampal NR2B-NMDARs to spatial working memory on delayed alternation task in T-maze (DAT task) and delayed matched-to-place task in water maze (DMP task). Our data show that infusions of the NR2B-NMDAR selective antagonists, Ro25-6981 or ifenprodil, directly into the CA1 region, impair spatial working memory in DAT task with 30-s delay (not 5-s delay), but severely impair error-correction capability in both 5-s and 30-s delay task. Furthermore, intra-CA1 inhibition of NR2B-NMDARs impairs spatial working memory in DMP task with 10-min delay (not 30-s delay). Our results suggest that hippocampal NR2B-NMDARs are required for spatial working memory in long-delay task, whereas spare for spatial working memory in short-delay task. We conclude that the requirement of NR2B-NMDARs for spatial working memory is delay-dependent in the CA1 region.
- Published
- 2013
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30. Autophagy-assisted antigen cross-presentation: Autophagosome as the argo of shared tumor-specific antigens and DAMPs.
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Yi Y, Zhou Z, Shu S, Fang Y, Twitty C, Hilton TL, Aung S, Urba WJ, Fox BA, Hu HM, and Li Y
- Abstract
It is generally believed that most tumor antigens are passively released from either health or dying tumor cells as intact soluble antigens, peptide fragments complexed with heat shock proteins (HSPs), or packaged in secretary vesicles in the form of microparticles or exosomes. The passive release of tumor antigens is generally non-inflammatory and non-immunogenic; however, results from others and our laboratories suggest that autophagy is critically involved in immunogenic cell death.
- Published
- 2012
- Full Text
- View/download PDF
31. Effect of diindolylmethane on Ca(2+) movement and viability in HA59T human hepatoma cells.
- Author
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Cheng JS, Shu SS, Kuo CC, Chou CT, Tsai WL, Fang YC, Kuo LN, Yeh JH, Chen WC, Chien JM, Lu T, Pan CC, Cheng HH, Chai KL, and Jan CR
- Subjects
- Apoptosis drug effects, Calcium Channel Blockers pharmacology, Carcinoma, Hepatocellular metabolism, Carcinoma, Hepatocellular pathology, Cell Line, Tumor, Cell Survival, Dose-Response Relationship, Drug, Econazole pharmacology, Endoplasmic Reticulum drug effects, Endoplasmic Reticulum metabolism, Fura-2 metabolism, Humans, Hydroquinones pharmacology, Imidazoles pharmacology, Liver Neoplasms metabolism, Liver Neoplasms pathology, Nifedipine pharmacology, Phospholipases A2 metabolism, Protein Kinase C metabolism, Tetrazolium Salts analysis, Tetrazolium Salts metabolism, Thapsigargin pharmacology, Calcium metabolism, Carcinoma, Hepatocellular drug therapy, Indoles pharmacology, Liver Neoplasms drug therapy
- Abstract
The effect of diindolylmethane, a natural compound derived from indole-3-carbinol in cruciferous vegetables, on cytosolic Ca(2+) concentrations ([Ca(2+)](i)) and viability in HA59T human hepatoma cells is unclear. This study explored whether diindolylmethane changed [Ca(2+)](i) in HA59T cells. The Ca(2+)-sensitive fluorescent dye fura-2 was applied to measure [Ca(2+)](i). Diindolylmethane at concentrations of 1-50 μM evoked a [Ca(2+)](i) rise in a concentration-dependent manner. The signal was reduced by removing Ca(2+). Diindolylmethane-induced Ca(2+) influx was not inhibited by nifedipine, econazole, SK&F96365, and protein kinase C modulators but was inhibited by aristolochic acid. In Ca(2+)-free medium, treatment with the endoplasmic reticulum Ca(2+) pump inhibitors thapsigargin or 2,5-di-tert-butylhydroquinone (BHQ) inhibited or abolished diindolylmethane-induced [Ca(2+)](i) rise. Incubation with diindolylmethane inhibited thapsigargin or BHQ-induced [Ca(2+)](i) rise. Inhibition of phospholipase C with U73122 reduced diindolylmethane-induced [Ca(2+)](i) rise. At concentrations of 10-75 μM, diindolylmethane killed cells in a concentration-dependent manner. The cytotoxic effect of diindolylmethane was not reversed by chelating cytosolic Ca(2+) with 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid. Propidium iodide staining data suggest that diindolylmethane (25-50 μM) induced apoptosis in a concentration-dependent manner. Collectively, in HA59T cells, diindolylmethane induced a [Ca(2+)](i) rise by causing phospholipase C-dependent Ca(2+) release from the endoplasmic reticulum and Ca(2+) influx via phospholipase A(2)-sensitive channels. Diindolylmethane induced cell death that may involve apoptosis.
- Published
- 2011
- Full Text
- View/download PDF
32. The mechanism of sertraline-induced [Ca(2+) ](i) rise in human PC3 prostate cancer cells.
- Author
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Huang JK, Chang HT, Chou CT, Shu SS, Kuo CC, Tsai JY, Liao WC, Wang JL, Lin KL, Lu YC, Chen IS, Liu SI, Ho CM, and Jan CR
- Subjects
- Apoptosis, Calcium Signaling drug effects, Cell Line, Tumor, Cell Survival drug effects, Humans, Male, Manganese metabolism, Prostatic Neoplasms pathology, Type C Phospholipases physiology, Antidepressive Agents pharmacology, Calcium metabolism, Prostatic Neoplasms metabolism, Sertraline pharmacology
- Abstract
The effect of sertraline, an antidepressant, on cytosolic-free Ca(2+) levels ([Ca(2+) ](i) ) in human cancer cells is unclear. This study examined whether sertraline altered basal [Ca(2+) ](i) levels in suspended PC3 human prostate cancer cells by using fura-2 as a Ca(2+) -sensitive fluorescent probe. At concentrations of 10-150 μM, sertraline induced a [Ca(2+) ](i) rise in a concentration-dependent fashion. The Ca(2+) signal was reduced partly by removing extracellular Ca(2+) indicating that Ca(2+) entry and release both contributed to the [Ca(2+) ](i) rise. Sertraline induced Mn(2+) influx, leading to quench of fura-2 fluorescence suggesting Ca(2+) influx. This Ca(2+) influx was inhibited by the suppression of store-operated Ca(2+) channels or by the modulation of protein kinase C activity. In Ca(2+) -free medium, pre-treatment with the endoplasmic reticulum Ca(2+) pump inhibitor thapsigargin or 2,5-di-(t-butyl)-1,4-hydroquinone nearly abolished sertraline-induced Ca(2+) release. Conversely, pre-treatment with sertraline greatly reduced the inhibitor-induced [Ca(2+) ](i) rise, suggesting that sertraline released Ca(2+) from the endoplasmic reticulum. Inhibition of phospholipase C inhibited sertraline-induced [Ca(2+) ](i) rise. At 20-30 μM, sertraline killed cells in a concentration-dependent manner. The cytotoxic effect of sertraline was enhanced by chelating cytosolic Ca(2+) with 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid/AM. Annexin V-FITC data suggest that sertraline (20 and 30 μM) evoked apoptosis in a concentration-dependent manner. Together, in PC3 human prostate cancer cells, sertraline induced [Ca(2+) ](i) rises by causing phospholipase C-dependent Ca(2+) release from the endoplasmic reticulum and via multiple Ca(2+) influx pathways that involve store-operated Ca(2+) channels. Sertraline also induced apoptosis that was not triggered by [Ca(2+) ](i) rise., (© 2011 The Authors. Basic & Clinical Pharmacology & Toxicology © 2011 Nordic Pharmacological Society.)
- Published
- 2011
- Full Text
- View/download PDF
33. Effect of thapsigargin on Ca²+ fluxes and viability in human prostate cancer cells.
- Author
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Huang JK, Chou CT, Chang HT, Shu SS, Kuo CC, Tsai JY, Liao WC, Wang JL, Lin KL, Lu YC, Chen IS, Liu SI, Ho CM, and Jan CR
- Subjects
- Apoptosis drug effects, Aristolochic Acids pharmacology, Cell Line, Tumor, Cell Survival drug effects, Estrenes pharmacology, Fluorescence, Fura-2 metabolism, Humans, Intracellular Space drug effects, Intracellular Space metabolism, Male, Manganese metabolism, Prostatic Neoplasms enzymology, Pyrrolidinones pharmacology, Type C Phospholipases metabolism, Calcium metabolism, Calcium Signaling drug effects, Prostatic Neoplasms metabolism, Prostatic Neoplasms pathology, Thapsigargin pharmacology
- Abstract
Effect of the carcinogen thapsigargin on human prostate cancer cells is unclear. This study examined if thapsigargin altered basal [Ca²⁺](i) levels in suspended PC3 human prostate cancer cells by using fura-2 as a Ca²⁺-sensitive fluorescent probe. Thapsigargin at concentrations between 10 nM and 10 µM increased [Ca²⁺](i) in a concentration-dependent fashion. The Ca²⁺ signal was reduced partly by removing extracellular Ca²⁺ indicating that Ca²⁺ entry and release both contributed to the [Ca²⁺](i) rise. This Ca²⁺ influx was inhibited by suppression of phospholipase A2, but not by inhibition of store-operated Ca²⁺ channels or by modulation of protein kinase C activity. In Ca²⁺-free medium, pretreatment with the endoplasmic reticulum Ca²⁺ pump inhibitor 2,5-di-(t-butyl)-1,4-hydroquinone (BHQ) nearly abolished thapsigargin-induced Ca²⁺ release. Conversely, pretreatment with thapsigargin greatly reduced BHQ-induced [Ca²⁺](i) rise, suggesting that thapsigargin released Ca²⁺ from the endoplasmic reticulum. Inhibition of phospholipase C did not change thapsigargin-induced [Ca²⁺](i) rise. At concentrations of 1-10 µM, thapsigargin induced cell death that was partly reversed by chelation of Ca²⁺ with BAPTA/AM. Annexin V/propidium iodide staining data suggest that apoptosis was partly responsible for thapsigargin-induced cell death. Together, in PC3 human prostate cancer cells, thapsigargin induced [Ca²⁺](i) rises by causing phospholipase C-independent Ca²⁺ release from the endoplasmic reticulum and Ca²⁺ influx via phospholipase A2-sensitive Ca²⁺ channels. Thapsigargin also induced cell death via Ca²⁺-dependent pathways and Ca²⁺-independent apoptotic pathways.
- Published
- 2011
- Full Text
- View/download PDF
34. Effect of methoxychlor on Ca2+ handling and viability in OC2 human oral cancer cells.
- Author
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Tseng LL, Shu SS, Kuo CC, Chou CT, Hsieh YD, Chu ST, Chi CC, Liang WZ, Ho CM, and Jan CR
- Subjects
- Analysis of Variance, Apoptosis, Calcium Signaling drug effects, Cell Death, Cell Line, Tumor, Cytosol metabolism, Egtazic Acid analogs & derivatives, Egtazic Acid metabolism, Endoplasmic Reticulum drug effects, Endoplasmic Reticulum pathology, Estrenes metabolism, Fura-2, Humans, Hydroquinones metabolism, Nifedipine metabolism, Protein Kinase C metabolism, Pyrrolidinones metabolism, Type C Phospholipases antagonists & inhibitors, Calcium metabolism, Cell Survival drug effects, Insecticides pharmacology, Methoxychlor pharmacology, Mouth Neoplasms pathology
- Abstract
The effect of the insecticide methoxychlor on the physiology of oral cells is unknown. This study aimed to explore the effect of methoxychlor on cytosolic Ca(2+) concentrations ([Ca(2+)](i)) in human oral cancer cells (OC2) by using the Ca(2+)-sensitive fluorescent dye fura-2. Methoxychlor at 5-20 μM increased [Ca(2+)](i) in a concentration-dependent manner. The signal was reduced by 70% by removing extracellular Ca(2+). Methoxychlor-induced Ca(2+) entry was not affected by nifedipine, econazole, SK&F96365 and protein kinase C modulators but was inhibited by the phospholipase A2 inhibitor aristolochic acid. In Ca(2+)-free medium, treatment with the endoplasmic reticulum Ca(2+) pump inhibitor thapsigargin or 2,5-di-tert-butylhydroquinone (BHQ) inhibited or abolished methoxychlor-induced [Ca(2+)](i) rise. Incubation with methoxychlor also inhibited thapsigargin- or BHQ-induced [Ca(2+)](i) rise. Inhibition of phospholipase C with U73122 did not alter methoxychlor-induced [Ca(2+)](i) rise. At 5-20 μM, methoxychlor killed cells in a concentration-dependent manner. The cytotoxic effect of methoxychlor was not reversed by chelating cytosolic Ca(2+) with 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid/AM (BAPTA/AM). Annexin V-FITC data suggest that methoxychlor (10 and 20 μM) evoked apoptosis in a concentration-dependent manner. Together, in human OC2, methoxychlor induced a [Ca(2+)](i) rise probably by inducing phospholipase C-independent Ca(2+) release from the endoplasmic reticulum and Ca(2+) entry via phospholipase A(2)-sensitive channels. Methoxychlor induced cell death that may involve apoptosis., (© 2011 The Authors. Basic & Clinical Pharmacology & Toxicology © 2011 Nordic Pharmacological Society.)
- Published
- 2011
- Full Text
- View/download PDF
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