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Sample records for cationic protein-induced apoptosis

  1. Research of BH3 domain protein inducing cell apoptosis

    Institute of Scientific and Technical Information of China (English)

    FENG Wan-yu; LIU Yang; ZHANG Zhi-cheng

    2008-01-01

    Objective BH3 domain protein plays an important role in control mechanism of cell apoptosis. The article mainly discusses its mechanism of promoting cell apoptosis and control. Methods The article analyzed and evaluated the mechanism of BH3 domain protein promoting cell apoptosis by internal and overseas literature. Results Activation of BH3 domain protein could promote the increase of mitochondrial membrane permeability, then it would start mitoehondrial apoptosis pathway, and at the last the cell apoptosis. Conclusions BH3 domain protein is the necessary condition of starting cell apoptosis. Its activation can cause cell apoptosis.

  2. TGEV nucleocapsid protein induces cell cycle arrest and apoptosis through activation of p53 signaling

    Energy Technology Data Exchange (ETDEWEB)

    Ding, Li [College of Veterinary Medicine, Northwest A and F University, Yangling, Shaanxi 712100 (China); College of Life Sciences, Hainan Normal University, Haikou, Hainan 571158 (China); Huang, Yong; Du, Qian; Dong, Feng; Zhao, Xiaomin; Zhang, Wenlong; Xu, Xingang [College of Veterinary Medicine, Northwest A and F University, Yangling, Shaanxi 712100 (China); Tong, Dewen, E-mail: dwtong@nwsuaf.edu.cn [College of Veterinary Medicine, Northwest A and F University, Yangling, Shaanxi 712100 (China)

    2014-03-07

    Highlights: • TGEV N protein reduces cell viability by inducing cell cycle arrest and apoptosis. • TGEV N protein induces cell cycle arrest and apoptosis by regulating p53 signaling. • TGEV N protein plays important roles in TGEV-induced cell cycle arrest and apoptosis. - Abstract: Our previous studies showed that TGEV infection could induce cell cycle arrest and apoptosis via activation of p53 signaling in cultured host cells. However, it is unclear which viral gene causes these effects. In this study, we investigated the effects of TGEV nucleocapsid (N) protein on PK-15 cells. We found that TGEV N protein suppressed cell proliferation by causing cell cycle arrest at the S and G2/M phases and apoptosis. Characterization of various cellular proteins that are involved in regulating cell cycle progression demonstrated that the expression of N gene resulted in an accumulation of p53 and p21, which suppressed cyclin B1, cdc2 and cdk2 expression. Moreover, the expression of TGEV N gene promoted translocation of Bax to mitochondria, which in turn caused the release of cytochrome c, followed by activation of caspase-3, resulting in cell apoptosis in the transfected PK-15 cells following cell cycle arrest. Further studies showed that p53 inhibitor attenuated TGEV N protein induced cell cycle arrest at S and G2/M phases and apoptosis through reversing the expression changes of cdc2, cdk2 and cyclin B1 and the translocation changes of Bax and cytochrome c induced by TGEV N protein. Taken together, these results demonstrated that TGEV N protein might play an important role in TGEV infection-induced p53 activation and cell cycle arrest at the S and G2/M phases and apoptosis occurrence.

  3. Telencephalin protects PAJU cells from amyloid beta protein-induced apoptosis by activating the ezrin/radixin/moesin protein family/phosphatidylinositol-3-kinase/protein kinase B pathway

    Institute of Scientific and Technical Information of China (English)

    Heping Yang; Dapeng Wu; Xiaojie Zhang; Xiang Wang; Yi Peng; Zhiping Hu

    2012-01-01

    Telencephalin is a neural glycoprotein that reduces apoptosis induced by amyloid beta protein in the human neural tumor cell line PAJU.In this study,we examined the role of the ezrin/radixin/moesin protein family/phosphatidylinositol-3-kinase/protein kinase B pathway in this process.Western blot analysis demonstrated that telencephalin,phosphorylated ezrin/radixin/moesin and phosphatidylinositol-3-kinase/protein kinase B were not expressed in PAJU cells transfected with empty plasmid,while they were expressed in PAJU cells transfected with a telencephalin expression plasmid.After treatment with 1.0 nM amyloid beta protein 42,expression of telencephalin and phosphorylated phosphatidylinositol-3-kinase/protein kinase B in the transfected cells gradually diminished,while levels of phosphorylated ezrin/radixin/moesin increased.In addition,the high levels of telencephalin,phosphorylated ezrin/radixin/moesin and phosphatidylinositol-3-kinase/protein kinase B expression in PAJU cells transfected with a telencephalin expression plasmid could be suppressed by the phosphatidylinositol-3-kinase inhibitor LY294002.These findings indicate that telencephalin activates the ezrin/radixin/moesin family/phosphatidylinositol-3-kinase/protein kinase B pathway and protects PAJU cells from amyloid beta protein-induced apoptosis.

  4. RBP-J-interacting and tubulin-associated protein induces apoptosis and cell cycle arrest in human hepatocellular carcinoma by activating the p53–Fbxw7 pathway

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Haihe [The Key Laboratory of Molecular Diagnosis in Laboratory Medicine, Department of Pathogenobiology, Daqing Branch of Harbin Medical University, Daqing 163319 (China); Yang, Zhanchun [Department of General Surgery of Fifth Clinical Hospital of Harbin Medical University, Daqing 163319 (China); Liu, Chunbo; Huang, Shishun; Wang, Hongzhi; Chen, Yingli [The Key Laboratory of Molecular Diagnosis in Laboratory Medicine, Department of Pathogenobiology, Daqing Branch of Harbin Medical University, Daqing 163319 (China); Chen, Guofu, E-mail: zhangyanjie3@aliyun.com [Department of General Surgery of Fifth Clinical Hospital of Harbin Medical University, Daqing 163319 (China)

    2014-11-07

    Highlights: • RITA overexpression increased protein expression of p53 and Fbxw7 and downregulated the expression of cyclin D1, cyclin E, CDK2, Hes-1 and NF-κB p65. • RITA can significantly inhibit the in vitro growth of SMMC7721 and HepG2 cells. • RITA exerts tumor-suppressive effects in hepatocarcinogenesis through induction of G0/G1 cell cycle arrest and apoptosis and suggest a therapeutic application of RITA in HCC. - Abstract: Aberrant Notch signaling is observed in human hepatocellular carcinoma (HCC) and has been associated with the modulation of cell growth. However, the role of Notch signaling in HCC and its underlying mechanism remain elusive. RBP-J-interacting and tubulin-associated (RITA) mediates the nuclear export of RBP-J to tubulin fibers and downregulates Notch-mediated transcription. In this study, we found that RITA overexpression increased protein expression of p53 and Fbxw7 and downregulated the expression of cyclin D1, cyclin E, CDK2, Hes-1 and NF-κB p65. These changes led to growth inhibition and induced G0/G1 cell cycle arrest and apoptosis in SMMC7721 and HepG2 cells. Our findings indicate that RITA exerts tumor-suppressive effects in hepatocarcinogenesis through induction of G0/G1 cell cycle arrest and apoptosis and suggest a therapeutic application of RITA in HCC.

  5. Anti-tumor Necrosis Factor Alpha (Infliximab) Attenuates Apoptosis, Oxidative Stress, and Calcium Ion Entry Through Modulation of Cation Channels in Neutrophils of Patients with Ankylosing Spondylitis.

    Science.gov (United States)

    Ugan, Yunus; Nazıroğlu, Mustafa; Şahin, Mehmet; Aykur, Mehmet

    2016-08-01

    Ankylosing Spondylitis (AS) is known to be associated with increased neutrophil activation and oxidative stress, however, the mechanism of neutrophil activation is still unclear. We have hypothesized that the antioxidant and anti-tumor necrosis factor properties of infliximab may affect intracellular Ca(2+) concentration in the neutrophils of AS patients. The objective of this study was to investigate the effects of infliximab on calcium signaling, oxidative stress, and apoptosis in neutrophils of AS patients. Neutrophils collected from ten patients with AS and ten healthy controls were used in the study. In a cell viability test, the ideal non-toxic dose and incubation time of infliximab were found as 100 μM and 1 h, respectively. In some experiments, the neutrophils were incubated with the voltage-gated calcium channel (VGCC) blockers verapamil + diltiazem (V + D) and the TRPM2 channel blocker 2-aminoethyl diphenylborinate (2-APB). Intracellular Ca(2+) concentration, lipid peroxidation, apoptosis, caspase 3, and caspase 9 values were high in neutrophils of AS patients and were reduced with infliximab treatment. Reduced glutathione level and glutathione peroxidase activity were low in the patients and increased with infliximab treatment. The intracellular Ca(2+) concentrations were low in 2-APB and V + D groups. In conclusion, the current study suggests that infliximab is useful against apoptotic cell death and oxidative stress in neutrophils of patients with AS, which seem to be dependent on increased levels of intracellular Ca(2+) through activation of TRPM2 and VGCC. PMID:26956056

  6. Molecular mechanisms of protein induced hyperinsulinaemic hypoglycaemia

    Institute of Scientific and Technical Information of China (English)

    Suresh; Chandran; Fabian; Yap; Khalid; Hussain

    2014-01-01

    The interplay between glucose metabolism and that of the two other primary nutrient classes, amino acids and fatty acids is critical for regulated insulin secretion. Mitochondrial metabolism of glucose, amino acid and fatty acids generates metabolic coupling factors(such as ATP, NADPH, glutamate, long chain acyl-CoA and diacylglycerol) which trigger insulin secretion. The observation of protein induced hypoglycaemia in patients with mutations in GLUD1 gene, encoding the enzyme glutamate dehydrogenase(GDH) and HADH gene, encoding for the enzyme short-chain 3-hydroxyacyl-CoA dehydrogenase has provided new mechanistic insights into the regulation of insulin secretion by amino acid and fatty acid metabolism. Metabolic signals arising from amino acid and fatty acid metabolism converge on the enzyme GDH which integrates both signals from both pathways and controls insulin secretion. Hence GDH seems to play a pivotal role in regulating both amino acid and fatty acid metabolism.

  7. Apoptin induces apoptosis in an oral cancer mouse model

    NARCIS (Netherlands)

    R.A.L. Schoop (Remilio); R.J. Baatenburg de Jong (Robert Jan); M.H.M. Noteborn (Mathieu)

    2008-01-01

    textabstractApoptin, a chicken anemia virus-derived protein, induces apoptosis in various tumor cell lines and xenografted tumors. Its apoptotic activity is not hampered by tumor-suppressor p53 mutations or overexpression of anti-apoptosis proteins Bcl-2 or Bcl-xL. We report for the first time the e

  8. Protooncogenes as mediators of apoptosis.

    Science.gov (United States)

    Teng, C S

    2000-01-01

    Apoptosis has been well established as a vital biological phenomenon that is important in the maintenance of cellular homeostasis. Three major protooncogene families and their encoded proteins function as mediators of apoptosis in various cell types and are the subject of this chapter. Protooncogenic proteins such as c-Myc/Max, c-Fos/c-Jun, and Bcl-2/Bax utilize a synergetic effect to enhance their roles in the pro- or antiapoptotic action. These family members activate and repress the expression of their target genes, control cell cycle progression, and execute programmed cell death. Repression or overproduction of these protooncogenic proteins induces apoptosis, which may vary as a result of either cell type specificity or the nature of the apoptotic stimuli. The proapoptotic and antiapoptotic proteins exert their effects in the membrane of cellular organelles. Here they generate cell-type-specific signals that activate the caspase family of proteases and their regulators for the execution of apoptosis.

  9. Allostery through protein-induced DNA bubbles.

    Science.gov (United States)

    Traverso, Joseph J; Manoranjan, Valipuram S; Bishop, A R; Rasmussen, Kim Ø; Voulgarakis, Nikolaos K

    2015-01-01

    Allostery through DNA is increasingly recognized as an important modulator of DNA functions. Here, we show that the coalescence of protein-induced DNA bubbles can mediate allosteric interactions that drive protein aggregation. We propose that such allostery may regulate DNA's flexibility and the assembly of the transcription machinery. Mitochondrial transcription factor A (TFAM), a dual-function protein involved in mitochondrial DNA (mtDNA) packaging and transcription initiation, is an ideal candidate to test such a hypothesis owing to its ability to locally unwind the double helix. Numerical simulations demonstrate that the coalescence of TFAM-induced bubbles can explain experimentally observed TFAM oligomerization. The resulting melted DNA segment, approximately 10 base pairs long, around the joints of the oligomers act as flexible hinges, which explains the efficiency of TFAM in compacting DNA. Since mitochondrial polymerase (mitoRNAP) is involved in melting the transcription bubble, TFAM may use the same allosteric interaction to both recruit mitoRNAP and initiate transcription.

  10. Allostery through protein-induced DNA bubbles

    Science.gov (United States)

    Traverso, Joseph J.; Manoranjan, Valipuram S.; Bishop, A. R.; Rasmussen, Kim Ø.; Voulgarakis, Nikolaos K.

    2015-03-01

    Allostery through DNA is increasingly recognized as an important modulator of DNA functions. Here, we show that the coalescence of protein-induced DNA bubbles can mediate allosteric interactions that drive protein aggregation. We propose that such allostery may regulate DNA's flexibility and the assembly of the transcription machinery. Mitochondrial transcription factor A (TFAM), a dual-function protein involved in mitochondrial DNA (mtDNA) packaging and transcription initiation, is an ideal candidate to test such a hypothesis owing to its ability to locally unwind the double helix. Numerical simulations demonstrate that the coalescence of TFAM-induced bubbles can explain experimentally observed TFAM oligomerization. The resulting melted DNA segment, approximately 10 base pairs long, around the joints of the oligomers act as flexible hinges, which explains the efficiency of TFAM in compacting DNA. Since mitochondrial polymerase (mitoRNAP) is involved in melting the transcription bubble, TFAM may use the same allosteric interaction to both recruit mitoRNAP and initiate transcription.

  11. A cationic cholesterol based nanocarrier for the delivery of p53-EGFP-C3 plasmid to cancer cells.

    Science.gov (United States)

    Misra, Santosh K; Naz, Sarwat; Kondaiah, Paturu; Bhattacharya, Santanu

    2014-01-01

    The p53 protein mediated anti-tumor strategy is limited due to the lack of suitable delivery agent with insignificant immunogenic response, serum compatibility, and early and easy detection of the transfected cell population. To overcome these problems, we generated a p53-EGFP-C3 fusion construct which expressed easily detectable green fluorescence protein (GFP) and allowed an estimation of p53 mediated anti-tumor activity. A mixture of cationic cholesterol gemini (Chol-5L) with natural lipid, DOPE (molar ratio 1:4), acronymed as Chol-5LD, formed a nano-liposome as characterized by various physical methods. The prepared clone was evaluated for the expression of GFP and functional p53 in HeLa and two additional cell lines with varied p53 status namely, H1299 (p53(-/-)) and HEK293T (p53(+/+)). Transfected cells were screened using RT-PCR, Western blotting, FACS analysis, MTT, Trypan blue assay and visualized under a fluorescence microscope. The p53-EGFP-C3 fusion protein induced apoptosis in cancer cells as evident from DNA fragmentation, cell cycle analysis, Annexin-V staining and PARP cleavage assays. The transfection and apoptosis induction efficiency of Chol-5LD was significantly higher than commercial reagents Lipofectamine2000 and Effectene irrespective of the cell lines examined. Further it significantly decreases the xenograft tumor volume in nude mice tumors via apoptosis as observed in H&E staining. PMID:24211075

  12. Food protein induced enterocolitis syndrome caused by rice beverage

    OpenAIRE

    Caminiti, Lucia; Salzano,Giuseppina; Crisafulli, Giuseppe; Porcaro, Federica; Pajno, Giovanni Battista

    2013-01-01

    Food protein-induced enterocolitis syndrome (FPIES) is an uncommon and potentially severe non IgE-mediated gastrointestinal food allergy. It is usually caused by cow’s milk or soy proteins, but may also be triggered by ingestion of solid foods. The diagnosis is made on the basis of clinical history and symptoms. Management of acute phase requires fluid resuscitation and intravenous steroids administration, but avoidance of offending foods is the only effective therapeutic option. Infant with ...

  13. Food protein induced enterocolitis syndrome caused by rice beverage.

    Science.gov (United States)

    Caminiti, Lucia; Salzano, Giuseppina; Crisafulli, Giuseppe; Porcaro, Federica; Pajno, Giovanni Battista

    2013-05-14

    Food protein-induced enterocolitis syndrome (FPIES) is an uncommon and potentially severe non IgE-mediated gastrointestinal food allergy. It is usually caused by cow's milk or soy proteins, but may also be triggered by ingestion of solid foods. The diagnosis is made on the basis of clinical history and symptoms. Management of acute phase requires fluid resuscitation and intravenous steroids administration, but avoidance of offending foods is the only effective therapeutic option.Infant with FPIES presented to our emergency department with vomiting, watery stools, hypothension and metabolic acidosis after ingestion of rice beverage. Intravenous fluids and steroids were administered with good clinical response. Subsequently, a double blind placebo control food challenge (DBPCFC) was performed using rice beverage and hydrolyzed formula (eHF) as placebo. The "rice based formula" induced emesis, diarrhoea and lethargy. Laboratory investigations reveal an increase of absolute count of neutrophils and the presence of faecal eosinophils. The patient was treated with both intravenous hydration and steroids. According to Powell criteria, oral food challenge was considered positive and diagnosis of FPIES induced by rice beverage was made. Patient was discharged at home with the indication to avoid rice and any rice beverage as well as to reintroduce hydrolyzed formula. A case of FPIES induced by rice beverage has never been reported. The present case clearly shows that also beverage containing rice proteins can be responsible of FPIES. For this reason, the use of rice beverage as cow's milk substitute for the treatment of non IgE-mediated food allergy should be avoided.

  14. Food protein induced enterocolitis syndrome caused by rice beverage.

    Science.gov (United States)

    Caminiti, Lucia; Salzano, Giuseppina; Crisafulli, Giuseppe; Porcaro, Federica; Pajno, Giovanni Battista

    2013-01-01

    Food protein-induced enterocolitis syndrome (FPIES) is an uncommon and potentially severe non IgE-mediated gastrointestinal food allergy. It is usually caused by cow's milk or soy proteins, but may also be triggered by ingestion of solid foods. The diagnosis is made on the basis of clinical history and symptoms. Management of acute phase requires fluid resuscitation and intravenous steroids administration, but avoidance of offending foods is the only effective therapeutic option.Infant with FPIES presented to our emergency department with vomiting, watery stools, hypothension and metabolic acidosis after ingestion of rice beverage. Intravenous fluids and steroids were administered with good clinical response. Subsequently, a double blind placebo control food challenge (DBPCFC) was performed using rice beverage and hydrolyzed formula (eHF) as placebo. The "rice based formula" induced emesis, diarrhoea and lethargy. Laboratory investigations reveal an increase of absolute count of neutrophils and the presence of faecal eosinophils. The patient was treated with both intravenous hydration and steroids. According to Powell criteria, oral food challenge was considered positive and diagnosis of FPIES induced by rice beverage was made. Patient was discharged at home with the indication to avoid rice and any rice beverage as well as to reintroduce hydrolyzed formula. A case of FPIES induced by rice beverage has never been reported. The present case clearly shows that also beverage containing rice proteins can be responsible of FPIES. For this reason, the use of rice beverage as cow's milk substitute for the treatment of non IgE-mediated food allergy should be avoided. PMID:23672828

  15. Baicalin induced dendritic cell apoptosis in vitro

    Directory of Open Access Journals (Sweden)

    Huahua eZhang

    2011-03-01

    Full Text Available This study was aimed to investigate the effects of Baicalin (BA, a major flavonoid constituent found in the herb Baikal skullcap, on dendritic cells (DCs. DCs were generated by culturing murine bone marrow cells for 6 days with granulocyte-macrophage colony-stimulating factor and interleukin-4, and lipopolysaccharide (LPS was added on day 5 to stimulate DCs maturation. The expression levels of DC maturity markers (CD80/CD86 were assessed by flow cytometry using direct immunofluorescence method. Interleukin-12 (IL-12 levels in the culture supernatants were assayed by ELISA. Apoptosis of DCs was analyzed by flow cytometry after Annexin V/propidium iodide staining. The mitochondrial membrane potential changes were measured by using the J-aggregate forming lipophilic cation 5,5',6,6'-tetrachloro-1,1',3,3'-tetraethylbenzimidazolcarbocyanine iodide (JC-1. Exposure of DCs to BA (2-50 microM during bone marrow cell differentiation showed no effects on the up-regulation of CD80/CD86 expression on DCs in response to LPS stimulation, but reduced DCs recovery by inducing apoptosis, and significantly inhibited the release of IL-12 to culture supernatants. BA induced DC apoptosis in a time- and dose-dependent way, and immature DCs were more sensitive for BA-induced apoptosis than mature DC. BA also induced mitochondrial membrane potential changes in DCs. These results demonstrate that BA induces selective apoptosis in immature DCs possibly through mitochondria-mediated pathway.

  16. A novel firefly luciferase biosensor enhances the detection of apoptosis induced by ESAT-6 family proteins of Mycobacterium tuberculosis

    International Nuclear Information System (INIS)

    Highlights: • We developed a novel firefly luciferase based biosensor to detect apoptosis. • The novel biosensor 233-DnaE-DEVDG was reliable, sensitive and convenient. • 233-DnaE-DEVDG faithfully indicated ESAT-6 family proteins of Mycobacterium tuberculosis induced apoptosis. • EsxA, esxT and esxL in ESAT-6 family proteins induced apoptosis. • Activation of nuclear factor-κB (NF-κB) participated in esxT-induced apoptosis. - Abstract: The activation of caspase-3 is a key surrogate marker for detecting apoptosis. To quantitate caspase-3 activity, we constructed a biosensor comprising a recombinant firefly luciferase containing a caspase-3 cleavage site. When apoptosis was induced, caspase-3 cleavage of the biosensor activated firefly luciferase by a factor greater than 25. The assay conveniently detected apoptosis in real time, indicating that it will facilitate drug discovery. We screened ESAT-6 family proteins of Mycobacterium tuberculosis and found that esxA, esxT and esxL induced apoptosis. Further, activation of nuclear factor-κB (NF-κB) and the NF-κB-regulated genes encoding tumor necrosis factor-α (TNF-α) and tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) participated in esxT-induced apoptosis. We conclude that this assay is useful for high-throughput screening to identify and characterize proteins and drugs that regulate apoptosis

  17. A novel firefly luciferase biosensor enhances the detection of apoptosis induced by ESAT-6 family proteins of Mycobacterium tuberculosis

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Junwei; Zhang, Huan; Fang, Liurong; Xi, Yongqiang; Zhou, Yanrong; Luo, Rui; Wang, Dang, E-mail: wangdang511@126.com; Xiao, Shaobo; Chen, Huanchun

    2014-10-03

    Highlights: • We developed a novel firefly luciferase based biosensor to detect apoptosis. • The novel biosensor 233-DnaE-DEVDG was reliable, sensitive and convenient. • 233-DnaE-DEVDG faithfully indicated ESAT-6 family proteins of Mycobacterium tuberculosis induced apoptosis. • EsxA, esxT and esxL in ESAT-6 family proteins induced apoptosis. • Activation of nuclear factor-κB (NF-κB) participated in esxT-induced apoptosis. - Abstract: The activation of caspase-3 is a key surrogate marker for detecting apoptosis. To quantitate caspase-3 activity, we constructed a biosensor comprising a recombinant firefly luciferase containing a caspase-3 cleavage site. When apoptosis was induced, caspase-3 cleavage of the biosensor activated firefly luciferase by a factor greater than 25. The assay conveniently detected apoptosis in real time, indicating that it will facilitate drug discovery. We screened ESAT-6 family proteins of Mycobacterium tuberculosis and found that esxA, esxT and esxL induced apoptosis. Further, activation of nuclear factor-κB (NF-κB) and the NF-κB-regulated genes encoding tumor necrosis factor-α (TNF-α) and tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) participated in esxT-induced apoptosis. We conclude that this assay is useful for high-throughput screening to identify and characterize proteins and drugs that regulate apoptosis.

  18. Ion exchange behaviour of polymeric zirconium cations

    International Nuclear Information System (INIS)

    Polymeric zirconium cations formed in weakly acid solutions (pH2) are taken up strongly into macroporous cation exchange resins, while uptake into normal cation exchange resins (pore diameter about 1 nm) is low. Macroporous cation exchange resins loaded with polymeric Zr cations are shown to function as ligand exchange sorbents. (Authors)

  19. Apoptosis in the Retina

    OpenAIRE

    Crisanti, Patricia; Lecain, Eric; Omri, Boubaker

    2007-01-01

    Retinal degenerations are a common cause of blindness in Western countries. Despite various origins of retinal degeneration it is well recognised that. Apoptosis is the final pathway of photoreceptor neuron cell death in these diseases. So that Ivana Scovassi presents the historical development of our knowledge in: apoptosis, its difference with other forms of cell death as necrosis and analyses when and how apoptosis arises, discussing also the molecular markers in this form of cell death. T...

  20. Inhibitor of apoptosis proteins and apoptosis

    Institute of Scientific and Technical Information of China (English)

    Yunbo Wei; Tingjun Fan; Miaomiao Yu

    2008-01-01

    Apoptosis is a physiological cell death process that plays a critical role in development, homeostasis, and immune defense of multicellular animals. Inhibitor of apoptosis proteins (IAPs) constitute a family of proteins that possess between one and three baculovirus IAP repeats. Some of them also have a really interesting new gene finger domain, and can prevent cell death by binding and inhibiting active caspases, but are regulated by IAP antagonists. Some evidence also indicates that IAP can modulate the cell cycle and signal transduction. The three main factors, IAPs, IAP antagonists, and caspases, are involved in regulating the progress of apoptosis in many species. Many studies and assumptions have been focused on the anfractuous interactions between these three main factors to explore their real functional model in order to develop potential anticancer drugs.In this review, we describe the classification, molecular structures, and properties of IAPs and discuss the mechanisms of apoptosis. We also discuss the promising significance of clinical applications of IAPs in the diagnosis and treatment of malignancy.

  1. Liquid-solid extraction of cationic metals by cationic amphiphiles

    International Nuclear Information System (INIS)

    In the field of selective separation for recycling of spent nuclear fuel, liquid-liquid extraction processes are widely used (PUREX, DIAMEX..) in industrial scale. In order to guarantee a sustainable nuclear energy for the forthcoming generations, alternative reprocessing techniques are under development. One of them bases on the studies from Heckmann et al in the 80's and consists in selectively precipitating actinides from aqueous waste solutions by cationic surfactants (liquid-solid extraction). This technique has some interesting advantages over liquid-liquid extraction techniques, because several steps are omitted like stripping or solvent washing. Moreover, the amount of waste is decreased considerably, since no contaminated organic solvent is produced. In this thesis, we have carried out a physico-chemical study to understand the specific interactions between the metallic cations with the cationic surfactant. First, we have analysed the specific effect of the different counter-ions (Cl-, NO3-, C2O42-) and then the effect of alkaline cations on the structural properties of the surfactant aggregation in varying thermodynamical conditions. Finally, different multivalent cations (Cu2+, Zn2+, UO22+, Fe3+, Nd3+, Eu3+, Th4+) were considered; we have concluded that depending on the anionic complex of these metals formed in acidic media, we can observe either an adsorption at the micellar interface or not. This adsorption has a large influence of the surfactant aggregation properties and determines the limits of the application in term of ionic strength, temperature and surfactant concentration. (author)

  2. Duck tembusu virus and its envelope protein induce programmed cell death.

    Science.gov (United States)

    Shaozhou, Wulin; Li, Chenxi; Zhang, Qingshan; Meng, Runzhe; Gao, Youlan; Liu, Hongyu; Bai, Xiaofei; Chen, Yuhuan; Liu, Ming; Liu, Siguo; Zhang, Yun

    2015-08-01

    The cytopathic effect produced in cells infected with duck tembusu virus (DTMUV) suggests that this emerging virus may induce apoptosis in primary cultures of duck embryo fibroblasts (DEF). Here, we present evidence that DTMUV infection of cultured cells activates apoptosis and that the ability of DTMUV to induce apoptosis is not restricted to cell type because DTMUV-induced apoptosis in duck and mammalian host cells. We further investigated which viral components induce apoptosis in DTMUV-infected host cells. The major envelope glycoprotein (E) was investigated for its apoptotic activities in expressed cells. Transient expression of the E protein alone triggered apoptosis in DEF, Vero, and BHK cells. Expression of the E protein resulted in activation of caspase-3-like proteases in cultured cells. These results indicate that infection of cells with DTMUV or expression of DTMUV E protein alone induces apoptosis, providing the basis for future to define the molecules that play key roles in the fate of DTMUV-infected cells. PMID:26056013

  3. Caspases: An apoptosis mediator

    Directory of Open Access Journals (Sweden)

    Tapan Kumar Palai

    2015-03-01

    Full Text Available The process of programmed cell death, or apoptosis, is generally characterized by distinct morphological characteristics and energy - dependent biochemical mechanisms. Apoptosis is a widely conserved phenomenon helping many processes, including normal cell turnover, proper development and functioning of the immune system, hormone dependent atrophy etc. Inappropriate apoptosis (either low level or high level leads to many developmental abnormalities like, neurodegenerative diseases, ischemic damage, autoimmune disorders and many types of cancer. To use cells for therapeutic purposes through generating cell lines, it is critical to study the cell cycle machinery and signalling pathways that controls cell death and apoptosis. Apoptotic pathways provide a fundamental protective mechanism that decreases cellular sensitivity to damaging events and allow proper developmental process in multi-cellular organisms. Major mediator of apoptosis is a family of proteins known as caspases. There are mainly fourteen types of caspases but out of them only ten caspasese have got essential role in controlling the process of apoptosis. These ten caspases have been categorized into either initiator caspases (caspase 2, 8, 9, 10 or executioner caspases (caspase 3, 6, 7. Although various types of caspases have been identified so far, the exact mechanisms of action of these groups of proteins is still to be fully understood. The aim of this review is to provide a detail overview of role of different caspases in regulating the process of apoptosis.

  4. Trace elements and apoptosis

    Energy Technology Data Exchange (ETDEWEB)

    Koudrine, A.V. [Orenburg State Medical Academy, Orenburg (Russian Federation)

    1998-07-01

    It is known that apoptosis is considered to be responsible for selective deletion of cells during embryogenesis, the homeostasis of cell populations in continuously renewing tissues (i.e., serving as a counterbalance to mitosis), and tissue involution in response to chemical or physical stimuli. There are many publications on these questions. On the other hand, the intracellular processes that contribute to apoptosis are incompletely understood. Therefore, the role of apoptosis in the intracellular accumulation and outflow of minerals is of considerable importance in light of both their essential functions and toxic effects. (orig.)

  5. DNA fragmentation in apoptosis

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Cleavage of chromosomal DNA into oligonucleosomal size fragments is an integral part of apoptosis. Elegant biochemical work identified the DNA fragmentation factor (DFF) as a major apoptotic endonuclease for DNA fragmentation in vitro. Genetic studies in mice support the importance of DFF in DNA fragmentation and possibly in apoptosis in vivo. Recent work also suggests the existence of additional endonucleases for DNA degradation. Understanding the roles of individual endonucleases in apoptosis, and how they might coordinate to degrade DNA in different tissues during normal development and homeostasis, as well as in various diseased states, will be a major research focus in the near future.

  6. Apoptosis in Pneumovirus Infection

    Directory of Open Access Journals (Sweden)

    Reinout A. Bem

    2013-01-01

    Full Text Available Pneumovirus infections cause a wide spectrum of respiratory disease in humans and animals. The airway epithelium is the major site of pneumovirus replication. Apoptosis or regulated cell death, may contribute to the host anti-viral response by limiting viral replication. However, apoptosis of lung epithelial cells may also exacerbate lung injury, depending on the extent, the timing and specific location in the lungs. Differential apoptotic responses of epithelial cells versus innate immune cells (e.g., neutrophils, macrophages during pneumovirus infection can further contribute to the complex and delicate balance between host defense and disease pathogenesis. The purpose of this manuscript is to give an overview of the role of apoptosis in pneumovirus infection. We will examine clinical and experimental data concerning the various pro-apoptotic stimuli and the roles of apoptotic epithelial and innate immune cells during pneumovirus disease. Finally, we will discuss potential therapeutic interventions targeting apoptosis in the lungs.

  7. A novel cationic lipid with intrinsic antitumor activity to facilitate gene therapy of TRAIL DNA.

    Science.gov (United States)

    Luo, Cong; Miao, Lei; Zhao, Yi; Musetti, Sara; Wang, Yuhua; Shi, Kai; Huang, Leaf

    2016-09-01

    Metformin (dimethylbiguanide) has been found to be effective for the treatment of a wide range of cancer. Herein, a novel lipid (1,2-di-(9Z-octadecenoyl)-3-biguanide-propane (DOBP)) was elaborately designed by utilizing biguanide as the cationic head group. This novel cationic lipid was intended to act as a gene carrier with intrinsic antitumor activity. When compared with 1,2-di-(9Z-octadecenoyl)-3-trimethylammonium-propane (DOTAP), a commercially available cationic lipid with a similar structure, the blank liposomes consisting of DOBP showed much more potent antitumor effects than DOTAP in human lung tumor xenografts, following an antitumor mechanism similar to metformin. Given its cationic head group, biguanide, DOBP could encapsulate TNF-related apoptosis-inducing ligand (TRAIL) plasmids into Lipid-Protamine-DNA (LPD) nanoparticles (NPs) for systemic gene delivery. DOBP-LPD-TRAIL NPs demonstrated distinct superiority in delaying tumor progression over DOTAP-LPD-TRAIL NPs, due to the intrinsic antitumor activity combined with TRAIL-induced apoptosis in the tumor. These results indicate that DOBP could be used as a versatile and promising cationic lipid for improving the therapeutic index of gene therapy in cancer treatment. PMID:27344367

  8. Cationic speciation in nonaqueous media

    International Nuclear Information System (INIS)

    Electronic spectra of solutions of d transition elements in the superacids HF, H2SO4, HSO3F, and CF3SO3H and in chloroaluminate melts indicate that in acidic monaqueous media the elements are present as solvated cations, whereas in basic media the speciation is anionic, the same situation as in aqueous solutions. Further, in very highly acidic media, cations in very low oxidation states are stable (e.g., Ti2+), but these disproportionate on addition of base to the system. In this paper spectra, where available, of U, Np, and Pu in oxidation states III and IV in aqueous media, in protonic superacids, and in chloroaluminates are presented to postulate cationic speciation of these early actinides in highly acidic media

  9. Protein induced by vitamin K absence or antagonist II-producing gastric cancer

    OpenAIRE

    Takahashi, Yoshihisa; Inoue, Tohru; Fukusato, Toshio

    2010-01-01

    Protein induced by vitamin K absence or antagonist II (PIVKA-II) is a putative specific marker of hepatocellular carcinoma (HCC), but it may also be produced by a small number of gastric cancers. To date, 16 cases of PIVKA-II-producing gastric cancer have been reported, 2 of which were reported by us and all of which were identified in Japan. There are no symptoms specific to PIVKA-II-producing gastric cancer, and the representative clinical symptoms are general fatigue, appetite loss, and up...

  10. Induction of apoptosis in purified animal and plant nuclei by Xenopus egg extracts

    Institute of Scientific and Technical Information of China (English)

    JIANGZHENGFAN; SHANZHU; 等

    1999-01-01

    We have developed a cell-free system that can trigger the nuclei purified from mouse liver and suspensioncultured carrot cells to undergo apoptosis as defined by the formation of apoptotic bodies and nucleosomal DNA fragments.The effects of different divalent cations and cycloheximide on DNA cleavage in this system were assessed.The fact that nuclei of plant cells can be induced to undergo apoptosis in a cell-free animal system suggests that animals and plants share a common signal transduction pathway triggering in the initiation stage of apoptosis.

  11. Research progress in cation-π interactions

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Cation-π interaction is a potent intermolecular interaction between a cation and an aromatic system,which has been viewed as a new kind of binding force,as being compared with the classical interactions(e.g. hydrogen bonding,electrostatic and hydrophobic interactions). Cation-π interactions have been observed in a wide range of biological contexts. In this paper,we present an overview of the typical cation-π interactions in biological systems,the experimental and theoretical investigations on cation-π interactions,as well as the research results on cation-π interactions in our group.

  12. Research progress in cation-π interactions

    Institute of Scientific and Technical Information of China (English)

    CHENG JiaGao; LUO XiaoMin; YAN XiuHua; LI Zhong; TANG Yun; JIANG HuaLiang; ZHU WeiLiang

    2008-01-01

    Cation-π interaction is a potent intermolecular interaction between a cation and an aromatic system, which has been viewed as a new kind of binding force, as being compared with the classical interac-tions (e.g. hydrogen bonding, electrostatic and hydrophobic interactions). Cation-π interactions have been observed in a wide range of biological contexts. In this paper, we present an overview of the typi-cal cation-π interactions in biological systems, the experimental and theoretical investigations on cation-π interactions, as well as the research results on cation-π interactions in our group.

  13. Radiolabeled Apoptosis Imaging Agents for Early Detection of Response to Therapy

    Directory of Open Access Journals (Sweden)

    Kazuma Ogawa

    2014-01-01

    Full Text Available Since apoptosis plays an important role in maintaining homeostasis and is associated with responses to therapy, molecular imaging of apoptotic cells could be useful for early detection of therapeutic effects, particularly in oncology. Radiolabeled annexin V compounds are the hallmark in apoptosis imaging in vivo. These compounds are reviewed from the genesis of apoptosis (cell death imaging agents up to recent years. They have some disadvantages, including slow clearance and immunogenicity, because they are protein-based imaging agents. For this reason, several studies have been conducted in recent years to develop low molecule apoptosis imaging agents. In this review, radiolabeled phosphatidylserine targeted peptides, radiolabeled bis(zinc(II-dipicolylamine complex, radiolabeled 5-fluoropentyl-2-methyl-malonic acid (ML-10, caspase-3 activity imaging agents, radiolabeled duramycin, and radiolabeled phosphonium cation are reviewed as promising low-molecular-weight apoptosis imaging agents.

  14. Tripodal Receptors for Cation and Anion Sensors

    NARCIS (Netherlands)

    Kuswandi, Bambang; Nuriman,; Verboom, Willem; Reinhoudt, David N.

    2006-01-01

    This review discusses different types of artificial tripodal receptors for the selectiverecognition and sensing of cations and anions. Examples on the relationship between structure andselectivity towards cations and anions are described. Furthermore, their applications as potentiometricion sensing

  15. Features definition exchange cations in sedimentary rocks.

    OpenAIRE

    Bilec'ka V.A.

    2008-01-01

    The research method of determination of exchange cations in calcareous sedimentary rocks of different extractants, the influence of the ratio between the solid and liquid phases on extrusion exchange cations.

  16. Features definition exchange cations in sedimentary rocks.

    Directory of Open Access Journals (Sweden)

    Bilec'ka V.A.

    2008-05-01

    Full Text Available The research method of determination of exchange cations in calcareous sedimentary rocks of different extractants, the influence of the ratio between the solid and liquid phases on extrusion exchange cations.

  17. LYMPHOCYTE APOPTOSIS IN PSORIASIS

    Directory of Open Access Journals (Sweden)

    О. M. Kapuler

    2006-01-01

    Full Text Available Abstract. Forty-two patients with progressive vulgar psoriasis (PASI = 19.7 ± 1.5 and 40 healthy volunteers were under investigation. Psoriatic patients were characterized by increased number of CD4+ CD95+ peripheral blood T lymphocytes, which correlates with clinical psoriatic score, and by increased levels of soluble Fas (sFas in serum, as compared to controls (resp., 1868.1 ± 186.8 pg/ml vs. 1281.4 ± 142.5 pg/ml, PLSD = 0.019. The levels of spontaneous lymphocyte apoptosis and anti-Fas (Mab-induced apoptosis in psoriatic patients did not differ from the controls. However, apoptosis induced by “oxidative stress” (50 M Н202, 4 hrs was depressed in the patients. Moreover, a simultaneous assessment of cell cycle structure (metachromatic staining with Acridine Orange, apoptosis and Fas receptor expression (AnnV-FITC/antiFas mAbs-PE staining following a short-term mitogenic stimulation (PHA-P, 5 µg/ml, 24 hrs were performed. We found no marked differences in mitogenic reactivity, activation-induced apoptosis, and activation-induced Fas receptor expression when studying lymphocytes from healthy donors and psoriatic patients. However, PHA-activated lymphocytes from psoriatic patients displayed a significantly decreased ratio of AnnV+CD95+ to the total AnnV+ subpopulation, thus suggesting a decreased role of Fas-dependent mechanisms of apoptosis during the cell activation. The data obtained confirm a view, that an abnormal lymphocyte “apoptotic reactivity”, which plays a crucial role in the mechanisms of autoimmunity, may also of importance in the pathogenesis of psoriasis.

  18. Apoptosis: una muerte silenciosa

    OpenAIRE

    Isis Casadelvalle Pérez

    2006-01-01

    La apoptosis o muerte celular programada es un tipo de muerte presente en todas las células eucarióticas. Es un proceso ordenado y esencial del desarrollo normal y de mantenimiento de la homeostasis de un organismo. En el presente trabajo se resumen las principales características fisiológicas, bioquímicas y moleculares de la muerte por apoptosis, evento que ocurre de forma apagada o silenciosa, o sea, sin daño celular aparente diferenciándose claramente del proceso de necrosis celular. En es...

  19. Apoptosis - Methods and Protocols

    Directory of Open Access Journals (Sweden)

    CarloAlberto Redi

    2010-03-01

    Full Text Available Apoptosis - Methods and ProtocolsSecond edition, 2009; Peter Erhardt and Ambrus Toth (Eds; Springer Protocols - Methods in molecular biology, vol. 559; Humana press, Totowa, New Jersey (USA; Pages: 400; €88.35; ISBN: 978-1-60327-016-8The editors rightly begin the preface telling us that: “The ability to detect and quantify apoptosis, to understand its biochemistry and to identify its regulatory genes and proteins is crucial to biomedical research”. Nowadays this is a grounding concept of biology and medicine. What is particularly remarkable...

  20. Cationic electrodepositable coating composition comprising lignin

    Science.gov (United States)

    Fenn, David; Bowman, Mark P; Zawacky, Steven R; Van Buskirk, Ellor J; Kamarchik, Peter

    2013-07-30

    A cationic electrodepositable coating composition is disclosed. The present invention in directed to a cationic electrodepositable coating composition comprising a lignin-containing cationic salt resin, that comprises (A) the reaction product of: lignin, an amine, and a carbonyl compound; (B) the reaction product of lignin, epichlorohydrin, and an amine; or (C) combinations thereof.

  1. Organometallic cation-exchanged phyllosilicates

    OpenAIRE

    Fleming, Shay

    1991-01-01

    Organotin (IV) complexes formed between 0 01 M dimethyltin dichloride solutions prepared at pH 2 6 and 4 0, and trimethyltin chloride prepared at pH 3 4, with Na- 119 montmori 1lonite clay have been characterised using Sn Mflssbauer spectroscopy, X-ray diffraction, thermogravimetric analysis and water sorption isotherms Following cation exchange, Mttssbauer spectroscopy identified two tin species in the dimethyltin (IV)-exchanged clay prepared at pH 2 6 A cis specie...

  2. Mediastinal Yolk Sac Tumor Producing Protein Induced by Vitamin K Absence or Antagonist-II.

    Science.gov (United States)

    Akutsu, Noriyuki; Adachi, Yasushi; Isosaka, Mai; Mita, Hiroaki; Takagi, Hideyasu; Sasaki, Shigeru; Yamamoto, Hiroyuki; Arimura, Yoshiaki; Ishii, Yoshifumi; Masumori, Naoya; Endo, Takao; Shinomura, Yasuhisa

    2015-01-01

    Extragonadal yolk sac tumors (YSTs) are rare. We herein report the case of a 66-year-old man with mediastinal, lung and liver tumors. The largest mass was located in the liver and contained a high concentration of protein induced by vitamin K absence or antagonist-II (PIVKA-II) and alpha-fetoprotein. Therefore, the lesion was difficult to distinguish from hepatocellular carcinoma. Finally, YST was diagnosed based on the results of a liver biopsy. Although chemotherapy was effective, the patient died of respiratory failure. The autopsy revealed primary mediastinal YST. In the current report, we describe this case of PIVKA-II-producing YST and review previous cases of PIVKA-II-producing tumors other than hepatoma.

  3. Mediastinal Yolk Sac Tumor Producing Protein Induced by Vitamin K Absence or Antagonist-II.

    Science.gov (United States)

    Akutsu, Noriyuki; Adachi, Yasushi; Isosaka, Mai; Mita, Hiroaki; Takagi, Hideyasu; Sasaki, Shigeru; Yamamoto, Hiroyuki; Arimura, Yoshiaki; Ishii, Yoshifumi; Masumori, Naoya; Endo, Takao; Shinomura, Yasuhisa

    2015-01-01

    Extragonadal yolk sac tumors (YSTs) are rare. We herein report the case of a 66-year-old man with mediastinal, lung and liver tumors. The largest mass was located in the liver and contained a high concentration of protein induced by vitamin K absence or antagonist-II (PIVKA-II) and alpha-fetoprotein. Therefore, the lesion was difficult to distinguish from hepatocellular carcinoma. Finally, YST was diagnosed based on the results of a liver biopsy. Although chemotherapy was effective, the patient died of respiratory failure. The autopsy revealed primary mediastinal YST. In the current report, we describe this case of PIVKA-II-producing YST and review previous cases of PIVKA-II-producing tumors other than hepatoma. PMID:26073245

  4. Food Protein-Induced Enterocolitis Syndrome as a Cause for Infant Hypotension

    Directory of Open Access Journals (Sweden)

    Marna Rayl Greenberg

    2011-05-01

    Full Text Available Infants with food protein-induced enterocolitis syndrome (FPIES may present to the emergency department (ED with vomiting and hypotension. A previously healthy, 5-month-old male presented with vomiting and hypotension 2 to 3 hours after eating squash. The patient was resuscitated with intravenous fluids, antibiotics, and admitted for presumed sepsis. No source of infection was ever found and the patient was discharged. The patient returned 8 days later with the same symptoms after eating sweet potatoes; the diagnosis of FPIES was made during this admission. Two additional ED visits occurred requiring hydration after new food exposure. FPIES should be considered in infants presenting with gastrointestinal complaints and hypotension. A dietary history, including if a new food has been introduced in the last few hours, may help facilitate earlier recognition of the syndrome. [West J Emerg Med. 2011;12(4:512–514.

  5. Apoptosis and inflammation

    Directory of Open Access Journals (Sweden)

    C. Haanen

    1995-01-01

    Full Text Available During the last few decades it has been recognized that cell death is not the consequence of accidental injury, but is the expression of a cell suicide programme. Kerr et al. (1972 introduced the term apoptosis. This form of cell death is under the influence of hormones, growth factors and cytokines, which depending upon the receptors present on the target cells, may activate a genetically controlled cell elimination process. During apoptosis the cell membrane remains intact and the cell breaks into apoptotic bodies, which are phagocytosed. Apoptosis, in contrast to necrosis, is not harmful to the host and does not induce any inflammatory reaction. The principal event that leads to inflammatory disease is cell damage, induced by chemical/physical injury, anoxia or starvation. Cell damage means leakage of cell contents into the adjacent tissues, resulting in the capillary transmigration of granulocytes to the injured tissue. The accumulation of neutrophils and release of enzymes and oxygen radicals enhances the inflammatory reaction. Until now there has been little research into the factors controlling the accumulation and the tissue load of granulocytes and their histotoxic products in inflammatory processes. Neutrophil apoptosis may represent an important event in the control of intlamtnation. It has been assumed that granulocytes disintegrate to apoptotic bodies before their fragments are removed by local macrophages. Removal of neutrophils from the inflammatory site without release of granule contents is of paramount importance for cessation of inflammation. In conclusion, apoptotic cell death plays an important role in inflammatory processes and in the resolution of inflammatory reactions. The facts known at present should stimulate further research into the role of neutrophil, eosinophil and macrophage apoptosis in inflammatory diseases.

  6. Use of laser induced photoacoustic spectroscopy (LIPAS) to determine equilibrium constants of cation-cation complexes

    International Nuclear Information System (INIS)

    Laser Induced PhotoAcoustic Spectroscopy (LIPAS) is a relatively new, photothermal technique to examine solutions. Studies in the past have shown it to be more sensitive than conventional absorption spectroscopy, while, yielding the same information thus allowing lower concentrations to be used. This study is using LIPAS to examine solutions to determine the equilibrium constants of cation-cation complexes. It has been found that actinyl(V) cations form cation-cation complexes with a variety of cations, including actinyl(VI) cations. The radioactive nature of the actinide elements requires special handling techniques and also require limits be placed on the amount of material that can be used. The sensitivity of some oxidation states of the actinides to oxygen also presents a problem. Preliminary results will be presented for actinyl(V)-actinyl(VI) cation-cation complexes that were studied using a remote LIPAS system incorporating fiber optics for transmission of laser signals

  7. The Free Tricoordinated Silyl Cation Problem

    Directory of Open Access Journals (Sweden)

    Čičak, H.

    2010-03-01

    Full Text Available As the importance and abundance of silicon in our environment is large, it has been thought that silicon might take the place of carbon in forming a host of similar compounds and silicon-based life. However, until today there is no experimental evidence for such a hypothesis and carbon is still unique among the elements in the vast number and variety of compounds it can form. Also, the corresponding derivatives of the two elements show considerable differences in their chemical properties.The essential debate concerning organosilicon chemistry relates to the existence of the free planar tricoordinated silyl cations in condensed phase (R3Si+, in analogy to carbocations (R3C+ which have been known and characterized as free species. Although silyl cations are thermodynamically more stable than their carbon analogs, they are very reactive due to their high inherent electrophilicity and the ability of hypervalent coordination. On the other hand, stabilization by inductive and hyperconjugative effects and larger steric effects of carbocations make them less sensitive to solvation or other environmental effects than silyl cations. Hence, observation of free silyl cations in the condensed phase proved extremely difficult and the actual problem is the question of the degree of the (remaining silyl cation character.The first free silyl cation, trimesitylsilyl cation, and in analogy with it tridurylsilyl cation, were synthesized by Lambert et al. Free silyl cations based on analogy to aromatic ions (homocyclopropenylium and tropylium have also been prepared. However, in these silyl cations the cationic character is reduced by internal π -conjugation. Čičak et al. prepared some silyl-cationic intermediates (Me3Si--CH≡CR+in solid state. With the help of quantum-mechanical calculations it was concluded that these adducts have much more silyl cation than carbocation character.

  8. Apoptosis and survival

    Directory of Open Access Journals (Sweden)

    Manjul Tiwari

    2011-01-01

    Full Text Available The term apoptosis first appeared in the biomedical literature in 1972, to delineate a structurally distinctive mode of cell death responsible for cell loss within living tissues. The cardinal morphological features are cell shrinkage, accompanied by transient but violent bubbling and blebbing from the surface, and culminating in separation of the cell into a cluster of membrane-bounded bodies. Changes in several cell surface molecules also ensure that, in tissues, apoptotic cells are immediately recognised and phagocytosed by their neighbours. However, it is important to note that apoptosis is only one form of cell death and the particular death pathway that is the most important determinant for cancer therapy is not necessarily that which has the fastest kinetics, as is the bias in many laboratories, but rather that which displays the most sensitive dose-response relationship.

  9. Fullerene and apoptosis

    Directory of Open Access Journals (Sweden)

    M. A. Orlova

    2013-01-01

    Full Text Available Fullerene derivatives superfamily attracts a serious attention as antiviral and anticancer agents and drug delivery carriers as well. A large number of such fullerene С60 derivatives obtained to date. However, there is an obvious deficit of information about causes and mechanisms of immediately and long-term consequences of their effects in vivo which is a true obstacle on the way leading to practical medical use of them. First, this concerns their impact on the proliferation, apoptosis and necrosis regulation. Fullerene nanoparticle functionalization type, their sizes and surface nanopathology are of great importance to further promoting of either cytoprotective or cytotoxic effects. This lecture provides modern concept analysis regarding fullerenes effects on apoptosis pathway in normal and tumor cells.

  10. Fullerene and apoptosis

    Directory of Open Access Journals (Sweden)

    M. A. Orlova

    2014-07-01

    Full Text Available Fullerene derivatives superfamily attracts a serious attention as antiviral and anticancer agents and drug delivery carriers as well. A large number of such fullerene С60 derivatives obtained to date. However, there is an obvious deficit of information about causes and mechanisms of immediately and long-term consequences of their effects in vivo which is a true obstacle on the way leading to practical medical use of them. First, this concerns their impact on the proliferation, apoptosis and necrosis regulation. Fullerene nanoparticle functionalization type, their sizes and surface nanopathology are of great importance to further promoting of either cytoprotective or cytotoxic effects. This lecture provides modern concept analysis regarding fullerenes effects on apoptosis pathway in normal and tumor cells.

  11. Apoptosis: una muerte silenciosa

    Directory of Open Access Journals (Sweden)

    Isis Casadelvalle Pérez

    2006-01-01

    Full Text Available La apoptosis o muerte celular programada es un tipo de muerte presente en todas las células eucarióticas. Es un proceso ordenado y esencial del desarrollo normal y de mantenimiento de la homeostasis de un organismo. En el presente trabajo se resumen las principales características fisiológicas, bioquímicas y moleculares de la muerte por apoptosis, evento que ocurre de forma apagada o silenciosa, o sea, sin daño celular aparente diferenciándose claramente del proceso de necrosis celular. En ese proceso se destaca la mitocondria, como organelo celular donde mediado por la activación de las caspasas se inicia el paso hacia la muerte celular programada. En el momento actual, la apoptosis ha cobrado un verdadero valor para la mejor comprensión de los procesos biológicos normales en los que este evento está involucrado y que con anterioridad no era tomado en cuenta. En este sentido, se comentan las principales técnicas de detección de muerte celular programada y se aclara que la elección de algunas de ellas depende del modelo de estudio. Tambi én se dan a conocer algunas de las patologías generales en las que este proceso representa un papel determinante y se discute acerca de cómo algunas alteraciones en los mecanismos de regulación de la apoptosis inducen la aparici ón de varias enfermedades, incluyendo aquellos desórdenes en los que ocurre acumulación celular (cáncer, alteración cardiaca, neurodegeneración y SIDA. El estudio y caracterización de este complejo mecanismo ha cambiado profundamente la comprensión de numerosas patologías en los organismos eucariotas.

  12. Mitochondrial dynamics and apoptosis

    OpenAIRE

    Suen, Der-Fen; Norris, Kristi L.; Youle, Richard J.

    2008-01-01

    In healthy cells, mitochondria continually divide and fuse to form a dynamic interconnecting network. The molecular machinery that mediates this organelle fission and fusion is necessary to maintain mitochondrial integrity, perhaps by facilitating DNA or protein quality control. This network disintegrates during apoptosis at the time of cytochrome c release and prior to caspase activation, yielding more numerous and smaller mitochondria. Recent work shows that proteins involved in mitochondri...

  13. A novel cationic liposome formulation for efficient gene delivery via a pulmonary route

    Science.gov (United States)

    Li, Peng; Liu, Donghua; Sun, Xiaoli; Liu, Chunxi; Liu, Yongjun; Zhang, Na

    2011-06-01

    The clinical success of gene therapy for lung cancer is not only dependent on efficient gene carriers but also on a suitable delivery route. A pulmonary delivery route can directly deliver gene vectors to the lung which is more efficient than a systemic delivery route. For gene carriers, cationic liposomes have recently emerged as leading non-viral vectors in worldwide gene therapy clinical trials. However, cytotoxic effects or apoptosis are often observed which is mostly dependent on the cationic lipid used. Therefore, an efficient and safe cationic lipid, 6-lauroxyhexyl lysinate (LHLN), previously synthesized by our group was first used to prepare cationic liposomes. Physicochemical and biological properties of LHLN-liposomes were investigated. LHLN-liposome/DNA complexes showed positive surface charge, spherical morphology, a relatively narrow particle size distribution and strong DNA binding capability. Compared with Lipofectamine2000, the new cationic liposome formulation using LHLN exhibited not only lower cytotoxicity (P transfection efficiency in A549 and HepG2 lung cancer cells for in vitro tests. When administered by intratracheal instillation into rat lungs for in vivo evaluation, LHLN-liposome/DNA complexes exhibited higher pulmonary gene transfection efficiency than Lipofectamine2000/DNA complexes (P < 0.05). These results suggested that LHLN-liposomes may have great potential for efficient pulmonary gene delivery.

  14. A novel cationic liposome formulation for efficient gene delivery via a pulmonary route

    International Nuclear Information System (INIS)

    The clinical success of gene therapy for lung cancer is not only dependent on efficient gene carriers but also on a suitable delivery route. A pulmonary delivery route can directly deliver gene vectors to the lung which is more efficient than a systemic delivery route. For gene carriers, cationic liposomes have recently emerged as leading non-viral vectors in worldwide gene therapy clinical trials. However, cytotoxic effects or apoptosis are often observed which is mostly dependent on the cationic lipid used. Therefore, an efficient and safe cationic lipid, 6-lauroxyhexyl lysinate (LHLN), previously synthesized by our group was first used to prepare cationic liposomes. Physicochemical and biological properties of LHLN-liposomes were investigated. LHLN-liposome/DNA complexes showed positive surface charge, spherical morphology, a relatively narrow particle size distribution and strong DNA binding capability. Compared with Lipofectamine2000, the new cationic liposome formulation using LHLN exhibited not only lower cytotoxicity (P < 0.05) but also similar transfection efficiency in A549 and HepG2 lung cancer cells for in vitro tests. When administered by intratracheal instillation into rat lungs for in vivo evaluation, LHLN-liposome/DNA complexes exhibited higher pulmonary gene transfection efficiency than Lipofectamine2000/DNA complexes (P < 0.05). These results suggested that LHLN-liposomes may have great potential for efficient pulmonary gene delivery.

  15. Severe Food Protein-Induced Enterocolitis Syndrome to Cow’s Milk in Infants

    Directory of Open Access Journals (Sweden)

    Min Yang

    2015-12-01

    Full Text Available Cow’s milk is the most common cause of food-protein-induced enterocolitis syndrome (FPIES. The aim of this study was to examine the clinical features and treatment outcomes of infants with severe FPIES to cow’s milk. We reviewed all infants ≤12 months of age who were hospitalized and diagnosed with severe FPIES to cow’s milk between 1 January 2011 and 31 August 2014 in a tertiary Children’s Medical Center in China. Patients’ clinical features, feeding patterns, laboratory tests, and treatment outcomes were reviewed. A total of 12 infants met the inclusion criteria. All infants presented with diarrhea, edema, and hypoalbuminemia. Other main clinical manifestations included regurgitation/vomiting, skin rashes, low-grade fever, bloody and/or mucous stools, abdominal distention, and failure to thrive. They had clinical remission with resolution of diarrhea and significant increase of serum albumin after elimination of cow’s milk protein (CMP from the diet. The majority of infants developed tolerance to the CMP challenge test after 12 months of avoidance. In conclusion, we reported the clinical experience of 12 infants with severe FPIES to cow’s milk, which resulted in malnutrition, hypoproteinemia, and failure to thrive. Prompt treatment with CMP-free formula is effective and leads to clinical remission of FPIES in infants.

  16. The Oncogenic Properties Of The Redox Inflammatory Protein Inducible Nitric Oxide Synthase In ER(- Breast Cancer

    Directory of Open Access Journals (Sweden)

    David A. Wink

    2015-08-01

    Full Text Available Inflammation generates reactive chemical species that induce conditions of oxidative nitrosative stress as emerged as factor in poor outcome of many cancers. Our recent findings show that in the inflammatory protein inducible nitric oxide synthase (iNOS is a strong predictor of poor outcome in ER(- patients (Glynn et al. JCI 2010. Furthermore 46 genes, of which 23 were associated with basal like breast cancer, were elevated when iNOS high. In vitro studies using ER(- cell lines showed that fluxes of nitric oxide (NO delivered by NO donors surprising mimic this relationship in the patient cohort. Using this model, we show that NO at different specific concentrations stimulate pro-oncogenic mechanisms such as AKT, ERK, NFkB, AP-1, and HIF-1α that lead to increase of metastatic and cancer stem cells proteins. In addition, we show that tumor suppressor gene BRCA1 and PP2A are inhibited by these NO levels. Similarly other studies show that these concentrations of NO increase immunosuppressive proteins TGF-β and IL-10 in leukocytes to decrease efficacy of some anticancer therapies further contributing to pro-tumorigenic environment. Using this model we have identified several new compounds that have efficacy in xenographic models. These finding have provided a model that shows how NO can affect numerous mechanism that leads to a more aggressive phenotype.

  17. Afrikaans Syllabification Patterns

    Directory of Open Access Journals (Sweden)

    Tilla Fick

    2010-01-01

    Full Text Available In contrast to English, automatic hyphenation by computer of Afrikaans words is a problem that still needs to be addressed, since errors are still often encountered in printed text. An initial step in this task is the ability to automatically syllabify words. Since new words are created continuously by joining words, it is necessary to develop an “intelligent” technique for syllabification. As a first phase of the research, we consider only the orthographic information of words, and disregard both syntactic and morphological information. This approach allows us to use machine-learning techniques such as artificial neural networks and decision trees that are known for their pattern recognition abilities. Both these techniques are trained with isolated patterns consisting of input patterns and corresponding outputs (or targets that indicate whether the input pattern should be split at a certain position, or not. In the process of compiling a list of syllabified words from which to generate training data for the  syllabification problem, irregular patterns were identified. The same letter patterns are split differently in different words and complete words that are spelled identically are split differently due to meaning. We also identified irregularities in and between  the different dictionaries that we used. We examined the influence range of letters that are involved in irregularities. For example, for their in agter-ente and vaste-rente we have to consider three letters to the left of r to be certain where the hyphen should be inserted. The influence range of the k in verstek-waarde and kleinste-kwadrate is four to the left and three to the right. In an analysis of letter patterns in Afrikaans words we found that the letter e has the highest frequency overall (16,2% of all letters in the word list. The frequency of words starting with s is the highest, while the frequency of words ending with e is the highest. It is important to

  18. Apoptosis and DNA Methylation

    Energy Technology Data Exchange (ETDEWEB)

    Meng, Huan X.; Hackett, James A. [MRC Human Genetics Unit, IGMM, Western General Hospital, Edinburgh EH4 2XU (United Kingdom); Nestor, Colm [MRC Human Genetics Unit, IGMM, Western General Hospital, Edinburgh EH4 2XU (United Kingdom); Breakthrough Research Unit, University of Edinburgh, Western General Hospital, Edinburgh EH4 2XU (United Kingdom); Dunican, Donncha S.; Madej, Monika; Reddington, James P. [MRC Human Genetics Unit, IGMM, Western General Hospital, Edinburgh EH4 2XU (United Kingdom); Pennings, Sari [Queen' s Medical Research Institute, University of Edinburgh, Edinburgh EH16 4TJ (United Kingdom); Harrison, David J. [Breakthrough Research Unit, University of Edinburgh, Western General Hospital, Edinburgh EH4 2XU (United Kingdom); Meehan, Richard R., E-mail: Richard.Meehan@hgu.mrc.ac.uk [MRC Human Genetics Unit, IGMM, Western General Hospital, Edinburgh EH4 2XU (United Kingdom); Breakthrough Research Unit, University of Edinburgh, Western General Hospital, Edinburgh EH4 2XU (United Kingdom)

    2011-04-01

    Epigenetic mechanisms assist in maintaining gene expression patterns and cellular properties in developing and adult tissues. The molecular pathology of disease states frequently includes perturbation of DNA and histone methylation patterns, which can activate apoptotic pathways associated with maintenance of genome integrity. This perspective focuses on the pathways linking DNA methyltransferases and methyl-CpG binding proteins to apoptosis, and includes new bioinformatic analyses to characterize the evolutionary origin of two G/T mismatch-specific thymine DNA glycosylases, MBD4 and TDG.

  19. Apoptosis and DNA Methylation

    Directory of Open Access Journals (Sweden)

    Richard R. Meehan

    2011-04-01

    Full Text Available Epigenetic mechanisms assist in maintaining gene expression patterns and cellular properties in developing and adult tissues. The molecular pathology of disease states frequently includes perturbation of DNA and histone methylation patterns, which can activate apoptotic pathways associated with maintenance of genome integrity. This perspective focuses on the pathways linking DNA methyltransferases and methyl-CpG binding proteins to apoptosis, and includes new bioinformatic analyses to characterize the evolutionary origin of two G/T mismatch-specific thymine DNA glycosylases, MBD4 and TDG.

  20. Localization versus delocalization in diamine radical cations

    DEFF Research Database (Denmark)

    Brouwer, A.M.; Wiering, P.G.; Zwier, J.M.;

    1997-01-01

    The optical absorption spectrum of the radical cation of 1,4-diphenylpiperazine 2a shows a strong transition in the near-IR, and only a weak band at 445 nm, in the region where aniline radical cations normally absorb strongly. This indicates that the charge and spin are delocalized over the two...

  1. Tripodal Receptors for Cation and Anion Sensors

    Directory of Open Access Journals (Sweden)

    David N. Reinhoudt

    2006-08-01

    Full Text Available This review discusses different types of artificial tripodal receptors for the selectiverecognition and sensing of cations and anions. Examples on the relationship between structure andselectivity towards cations and anions are described. Furthermore, their applications as potentiometricion sensing are emphasised, along with their potential applications in optical sensors or optodes.

  2. Apoptosis Resistance in Endometriosis

    Directory of Open Access Journals (Sweden)

    Liselotte Mettler

    2011-08-01

    Full Text Available Introduction: In a cytological analysis of endometriotic lesions neither granulocytes nor cytotoxic T-cells appear in an appreciable number. Based on this observation we aimed to know, whether programmed cell death plays an essential role in the destruction of dystopic endometrium. Disturbances of the physiological mechanisms of apoptosis, a persistence of endometrial tissue could explain the disease. Another aspect of this consideration is the proliferation competence of the dystopic mucous membrane. Methods: Endometriotic lesions of 15 patients were examined through a combined measurement of apoptosis activity with the TUNEL technique (terminal deoxyribosyltransferase mediated dUTP Nick End Labeling and the proliferation activity (with the help of the Ki-67-Antigens using the monoclonal antibody Ki-S5. Results: Twelve out of 15 women studied showed a positive apoptotic activity of 3-47% with a proliferation activity of 2-25% of epithelial cells. Therefore we concluded that the persistence of dystopic endometrium requires proliferative epithelial cells from middle to lower endometrial layers. Conclusion: A dystopia misalignment of the epithelia of the upper layers of the functionalism can be rapidly eliminated by apoptotic procedures.

  3. Apoptosis : Target of cancer therapy

    NARCIS (Netherlands)

    Ferreira, CG; Epping, M; Kruyt, FAE; Giaccone, G

    2002-01-01

    Recent knowledge on apoptosis has made it possible to devise novel approaches, which exploit this process to treat cancer. In this review, we discuss in detail approaches to induce tumor cell apoptosis, their mechanism of action, stage of development, and possible drawbacks. Finally, the obstacles y

  4. Nuclear Apoptosis Contributes to Sarcopenia

    OpenAIRE

    Alway, Stephen E.; Parco M. Siu

    2008-01-01

    Apoptosis results in DNA fragmentation and, subsequently, destruction of cells containing a single nucleus. Our hypothesis is that multinucleated cells such as muscle fibers can experience apoptotic-induced loss of single nuclei (nuclear apoptosis) without destruction of the entire fiber. The loss of nuclei likely contributes to atrophy and sarcopenia. Furthermore, increased chronic activity attenuates apoptotic signaling, which may reduce sarcopenia.

  5. Cardiovascular molecular imaging of apoptosis

    Energy Technology Data Exchange (ETDEWEB)

    Wolters, S.L.; Reutelingsperger, C.P.M. [Maastricht University, Department of Biochemistry, Cardiovascular Research Institute Maastricht, Maastricht (Netherlands); Corsten, M.F.; Hofstra, L. [Maastricht University, Department of Cardiology, Cardiovascular Research Institute Maastricht, P.O. Box 616, Maastricht (Netherlands); Narula, J. [University of California Irvine, Department of Cardiology, Irvine (United States)

    2007-06-15

    Molecular imaging strives to visualise processes at the molecular and cellular level in vivo. Understanding these processes supports diagnosis and evaluation of therapeutic efficacy on an individual basis and thereby makes personalised medicine possible. Apoptosis is a well-organised mode of cell suicide that plays a role in cardiovascular diseases (CVD). Apoptosis is associated with loss of cardiomyocytes following myocardial infarction, atherosclerotic plaque instability, congestive heart failure and allograft rejection of the transplanted heart. Thus, apoptosis constitutes an attractive target for molecular imaging of CVD. Our current knowledge about the molecular players and mechanisms underlying apoptosis offers a rich palette of potential molecular targets for molecular imaging. However, only a few have been successfully developed so far. This review highlights aspects of the molecular machinery and biochemistry of apoptosis relevant to the development of molecular imaging probes. It surveys the role of apoptosis in four major areas of CVD and portrays the importance and future perspectives of apoptosis imaging. The annexin A5 imaging protocol is emphasised since it is the most advanced protocol to measure apoptosis in both preclinical and clinical studies. (orig.)

  6. High Prevalence of Neutrophil Cytoplasmic Autoantibodies in Infants with Food Protein-Induced Proctitis/Proctocolitis: Autoimmunity Involvement?

    Directory of Open Access Journals (Sweden)

    Alena Sekerkova

    2015-01-01

    Full Text Available Background. Food protein-induced proctitis/proctocolitis (FPIP is the most common noninfectious colitis in children in the first year of life. Along with the overall clinical symptoms, diarrhoea and rectal bleeding are the main manifestations of the disease. There is no routine noninvasive test that would be specific for this type of colitis. The aim of our study was to find a noninvasive laboratory test or tests that may be helpful in differential diagnosis of food protein-induced proctitis/proctocolitis. Methods. ANA, ANCA, ASCA, a-EMA, a-tTg, specific IgE, total IgE, IgG, IgA, IgM, and concentration of serum calprotectin were measured in a group of 25 patients with colitis and 18 children with other diagnoses. Results. Atypical-pANCA antibodies of IgG isotype were detected in the sera of 24 patients by the method of indirect immunofluorescence, and 5 patients showed also the positivity of IgA isotype. In control samples these autoantibodies were not detected. Other autoantibodies were not demonstrated in either patient or control group. Conclusions. Of the parameters tested in noninfectious colitis, atypical-pANCA on ethanol-fixed granulocytes appears to be a suitable serological marker of food protein-induced proctitis/proctocolitis and suggests a possible involvement of an autoimmune mechanisms in the pathogenesis of this disease.

  7. Apoptosis Evaluation by Electrochemical Techniques.

    Science.gov (United States)

    Yin, Jian; Miao, Peng

    2016-03-01

    Apoptosis has close relevance to pathology, pharmacology, and toxicology. Accurate and convenient detection of apoptosis would be beneficial for biological study, clinical diagnosis, and drug development. Based on distinct features of apoptotic cells, a diversity of analytical techniques have been exploited for sensitive analysis of apoptosis, such as surface plasmon resonance, electrochemical methods, flow cytometry, and some imaging assays. Among them, the features of simplicity, easy operation, low cost, and high sensitivity make electrochemical techniques powerful tools to investigate electron-transfer processes of in vitro biological systems. In this contribution, a general overview of current knowledge on various technical approaches for apoptosis evaluation is provided. Furthermore, recently developed electrochemical biosensors for detecting apoptotic cells and their advantages over traditional methods are summarized. One of the main considerations focuses on designing the recognition elements based on various biochemical events during apoptosis.

  8. Caspase Family Proteases and Apoptosis

    Institute of Scientific and Technical Information of China (English)

    Ting-Jun FAN; Li-Hui HAN; Ri-Shan CONG; Jin LIANG

    2005-01-01

    Apoptosis, or programmed cell death, is an essential physiological process that plays a critical role in development and tissue homeostasis. The progress of apoptosis is regulated in an orderly way by a series of signal cascades under certain circumstances. The caspase-cascade system plays vital roles in the induction, transduction and amplification of intracellular apoptotic signals. Caspases, closely associated with apoptosis, are aspartate-specific cysteine proteases and members of the interleukin-1β-converting enzyme family. The activation and function of caspases, involved in the delicate caspase-cascade system, are regulated by various kinds of molecules, such as the inhibitor of apoptosis protein, Bcl-2 family proteins, calpain,and Ca2+. Based on the latest research, the members of the caspase family, caspase-cascade system and caspase-regulating molecules involved in apoptosis are reviewed.

  9. Cationic Bolaamphiphiles for Gene Delivery

    Science.gov (United States)

    Tan, Amelia Li Min; Lim, Alisa Xue Ling; Zhu, Yiting; Yang, Yi Yan; Khan, Majad

    2014-05-01

    Advances in medical research have shed light on the genetic cause of many human diseases. Gene therapy is a promising approach which can be used to deliver therapeutic genes to treat genetic diseases at its most fundamental level. In general, nonviral vectors are preferred due to reduced risk of immune response, but they are also commonly associated with low transfection efficiency and high cytotoxicity. In contrast to viral vectors, nonviral vectors do not have a natural mechanism to overcome extra- and intracellular barriers when delivering the therapeutic gene into cell. Hence, its design has been increasingly complex to meet challenges faced in targeting of, penetration of and expression in a specific host cell in achieving more satisfactory transfection efficiency. Flexibility in design of the vector is desirable, to enable a careful and controlled manipulation of its properties and functions. This can be met by the use of bolaamphiphile, a special class of lipid. Unlike conventional lipids, bolaamphiphiles can form asymmetric complexes with the therapeutic gene. The advantage of having an asymmetric complex lies in the different purposes served by the interior and exterior of the complex. More effective gene encapsulation within the interior of the complex can be achieved without triggering greater aggregation of serum proteins with the exterior, potentially overcoming one of the great hurdles faced by conventional single-head cationic lipids. In this review, we will look into the physiochemical considerations as well as the biological aspects of a bolaamphiphile-based gene delivery system.

  10. Cationic ruthenium alkylidene catalysts bearing phosphine ligands

    OpenAIRE

    Endo, Koji; Grubbs, Robert H.

    2016-01-01

    The discovery of highly active catalysts and the success of ionic liquid immobilized systems have accelerated attention to a new class of cationic metathesis catalysts. We herein report the facile syntheses of cationic ruthenium catalysts bear-ing bulky phosphine ligands. Simple ligand exchange using silver(I) salts of non-coordinating or weakly coordinating anions pro-vided either PPh3 or chelating Ph2P(CH2)nPPh2 (n = 2 or 3) ligated cationic catalysts. The structures of these newly reported...

  11. Cation locations and dislocations in zeolites

    Science.gov (United States)

    Smith, Luis James

    The focus of this dissertation is the extra-framework cation sites in a particular structural family of zeolites, chabazite. Cation sites play a particularly important role in the application of these sieves for ion exchange, gas separation, catalysis, and, when the cation is a proton, acid catalysis. Structural characterization is commonly performed through the use of powder diffraction and Rietveld analysis of powder diffraction data. Use of high-resolution nuclear magnetic resonance, in the study of the local order of the various constituent nuclei of zeolites, complements well the long-range order information produced by diffraction. Recent developments in solid state NMR techniques allow for increased study of disorder in zeolites particularly when such phenomena test the detection limits of diffraction. These two powerful characterization techniques, powder diffraction and NMR, offer many insights into the complex interaction of cations with the zeolite framework. The acids site locations in SSZ-13, a high silica chabazite, and SAPO-34, a silicoaluminophosphate with the chabazite structure, were determined. The structure of SAPO-34 upon selective hydration was also determined. The insensitivity of X-rays to hydrogen was avoided through deuteration of the acid zeolites and neutron powder diffraction methods. Protons at inequivalent positions were found to have different acid strengths in both SSZ-13 and SAPO-34. Other light elements are incorporated into zeolites in the form of extra-framework cations, among these are lithium, sodium, and calcium. Not amenable by X-ray powder diffraction methods, the positions of such light cations in fully ion-exchanged versions of synthetic chabazite were determined through neutron powder diffraction methods. The study of more complex binary cation systems were conducted. Powder diffraction and solid state NMR methods (MAS, MQMAS) were used to examine cation site preferences and dislocations in these mixed-akali chabazites

  12. Cycloaliphatic epoxide resins for cationic UV - cure

    International Nuclear Information System (INIS)

    This paper introduces the cyclo - aliphatic epoxide resins used for the various applications of radiation curing and their comparison with acrylate chemistry. Radiation curable coatings and inks are pre - dominantly based on acrylate chemistry but over the last few years, cationic chemistry has emerged successfully with the unique properties inherent with cyclo - aliphatic epoxide ring structures. Wide variety of cationic resins and diluents, the formulation techniques to achieve the desired properties greatly contributes to the advancement of UV - curing technology

  13. Cations and activated sludge floc structure

    OpenAIRE

    Park, Chul

    2002-01-01

    This research was designed to investigate the effect of cations on activated sludge characteristics and also to determine their influence on digestion performance. For this purpose, cations in solution and in floc were evaluated along with various activated sludge characteristics and the collected waste activated sludge underwent both anaerobic and aerobic digestion. It was found that large amounts of biopolymer (protein + polysaccharide) remained in the effluent of WWTP that received high in...

  14. Test procedure for cation exchange chromatography

    International Nuclear Information System (INIS)

    The purpose of this test plan is to demonstrate the synthesis of inorganic antimonate ion exchangers and compare their performance against the standard organic cation exchangers. Of particular interest is the degradation rate of both inorganic and organic cation exchangers. This degradation rate will be tracked by determining the ion exchange capacity and thermal stability as a function of time, radiation dose, and chemical reaction

  15. Silica-based cationic bilayers as immunoadjuvants

    OpenAIRE

    Carmona-Ribeiro Ana M; da Costa Maria; Faquim-Mauro Eliana; Santana Mariana RA; Lincopan Nilton

    2009-01-01

    Abstract Background Silica particles cationized by dioctadecyldimethylammonium bromide (DODAB) bilayer were previously described. This work shows the efficiency of these particulates for antigen adsorption and presentation to the immune system and proves the concept that silica-based cationic bilayers exhibit better performance than alum regarding colloid stability and cellular immune responses for vaccine design. Results Firstly, the silica/DODAB assembly was characterized at 1 mM NaCl, pH 6...

  16. Myelin basic protein induces neuron-specific toxicity by directly damaging the neuronal plasma membrane.

    Directory of Open Access Journals (Sweden)

    Jie Zhang

    Full Text Available The central nervous system (CNS insults may cause massive demyelination and lead to the release of myelin-associated proteins including its major component myelin basic protein (MBP. MBP is reported to induce glial activation but its effect on neurons is still little known. Here we found that MBP specifically bound to the extracellular surface of the neuronal plasma membrane and induced neurotoxicity in vitro. This effect of MBP on neurons was basicity-dependent because the binding was blocked by acidic lipids and competed by other basic proteins. Further studies revealed that MBP induced damage to neuronal membrane integrity and function by depolarizing the resting membrane potential, increasing the permeability to cations and other molecules, and decreasing the membrane fluidity. At last, artificial liposome vesicle assay showed that MBP directly disturbed acidic lipid bilayer and resulted in increased membrane permeability. These results revealed that MBP induces neurotoxicity through its direct interaction with acidic components on the extracellular surface of neuronal membrane, which may suggest a possible contribution of MBP to the pathogenesis in the CNS disorders with myelin damage.

  17. APOPTOSIS IN WHOLE MOUSE OVARIES

    Science.gov (United States)

    Apoptosis in Whole Mouse Ovaries Robert M. Zucker Susan C. Jeffay and Sally D. Perreault Reproductive Toxicology Division, National Health and Environmental Effects Research Laboratory, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina, 27711.

  18. Porcine circovirus-2 capsid protein induces cell death in PK15 cells

    Energy Technology Data Exchange (ETDEWEB)

    Walia, Rupali; Dardari, Rkia, E-mail: rdardari@ucalgary.ca; Chaiyakul, Mark; Czub, Markus

    2014-11-15

    Studies have shown that Porcine circovirus (PCV)-2 induces apoptosis in PK15 cells. Here we report that cell death is induced in PCV2b-infected PK15 cells that express Capsid (Cap) protein and this effect is enhanced in interferon gamma (IFN-γ)-treated cells. We further show that transient PCV2a and 2b-Cap protein expression induces cell death in PK15 cells at rate similar to PCV2 infection, regardless of Cap protein localization. These data suggest that Cap protein may have the capacity to trigger different signaling pathways involved in cell death. Although further investigation is needed to gain deeper insights into the nature of the pathways involved in Cap-induced cell death, this study provides evidence that PCV2-induced cell death in kidney epithelial PK15 cells can be mapped to the Cap protein and establishes the need for future research regarding the role of Cap-induced cell death in PCV2 pathogenesis. - Highlights: • IFN-γ enhances PCV2 replication that leads to cell death in PK15 cells. • IFN-γ enhances nuclear localization of the PCV2 Capsid protein. • Transient PCV2a and 2b-Capsid protein expression induces cell death. • Cell death is not dictated by specific Capsid protein sub-localization.

  19. Apoptosis in cancer: therapeutic implications

    OpenAIRE

    Negoescu, A.

    2000-01-01

    This review outlines the principal limitations of the mechanisms of active cell death (ACD, apoptosis) as the basis of tumorigenesis and the rationale of almost all therapies of malignancy. The concentration of cancer therapy in the directon of ACD induction is presented as both the result of progressive understanding of the mechanisms of apoptosis and that of the favourable tumor environment for ACD signal transmission. The latter property induces the by-stand...

  20. Invertebrate Iridovirus Modulation of Apoptosis

    Institute of Scientific and Technical Information of China (English)

    Trevor Williams; Nllesh S. Chitnis; Sh(a)n L. Bilimoria

    2009-01-01

    Programmed cell death (apoptosis) is a key host response to virus infection. Viruses that can modulate host apoptotic responses are likely to gain important opportunities for transmission. Here we review recent studies that demonstrate that particles of Invertebrate iridescent virus 6 (IIV-6) (Iridoviridae, genus Iridovirus), or an IIV-6 virion protein extract, are capable of inducing apoptosis in lepidopteran and coleopteran cells, at concentrations 1000-fold lower than that required to shut-off host macromolecular synthesis. Induction of apoptosis depends on endocytosis of one or more heat-sensitive virion component(s). Studies with a JNK inh ibitor(SP600125) indicated that the JNK signaling pathway is significantly involved in apoptosis in IIV-6 infections of Choristoneurafumiferana ceils. The genome of IIV-6 codes for an inhibitor of apoptosis iap gene (193R) that encodes a protein of 208 aa with 15% identity and 28% similarity in its amino acid sequence to IAP-3 from Cydia pomonella ganulovirus (CpGV). Transcription of IIV-6 iap did not require prior DNA or protein synthesis, indicating that it is an immediate-early class gene. Transient expression and gene knockdown studies have confirmed the functional nature of the IIV-6 iap gene. We present a tentative model for IIV-6 induction and inhibition of apoptosis in insect cells and discuss the potential applications of these findings in insect pest control.

  1. Optimizing an Aversion Feeding Therapy Protocol for a Child with Food Protein-Induced Enterocolitis Syndrome (FPIES)

    OpenAIRE

    Mattingly, Rhonda; Mukkada, Vincent; Smith, Alan; Pitts, Teresa

    2015-01-01

    This case study examines the difficulties of treating food aversion in a 9-month old child with a diagnosis of Food Protein-Induced Enterocolitis Syndrome (FPIES). Given the need to first identify a set of “safe foods” with which to work, the twin goals of doing food challenges and minimizing aversion are initially not complimentary, and require an approach outside the standard of care. The chosen plan encouraged flexibility and a positive relationship with feeding-related items, while only i...

  2. Clinical utility of protein induced by vitamin K absence in patients with chronic hepatitis B virus infection

    OpenAIRE

    TRUONG, BUI XUAN; Yano, Yoshihiko; VAN, VU TUONG; Seo, Yasushi; Nam, Nguyen Hoai; TRACH, NGUYEN KHANH; Utsumi, Takako; Azuma, Takeshi; Hayashi, Yoshitake

    2012-01-01

    Hepatitis B virus (HBV) is a leading cause of hepatocellular carcinoma (HCC). α-fetoprotein (AFP) is a common tumor marker for the diagnosis of HCC, although not for protein induced by the absence of vitamin K or antagonist-II (PIVKA-II). The present study aimed to evaluate the role of PIVKA-II in the diagnosis of HCC in HBV-infected Vietnamese patients. A total of 166 consecutive HBV-infected Vietnamese patients were enrolled, including 41 HCC, 43 liver cirrhosis (LC), 26 chronic hepatitis (...

  3. Innate cation sensitivity in a semiconducting polymer.

    Science.gov (United States)

    Althagafi, Talal M; Algarni, Saud A; Grell, Martin

    2016-09-01

    Water-gated organic thin film transistors (OTFTs) using the hole transporting semiconducting polymer, poly(2,5-bis(3-hexadecylthiophen-2-yl)thieno[3,2-b]thiophene) (PBTTT), show an innate response of their threshold voltage to the addition of divalent metal cations to the gating water, without deliberately introducing an ion-sensitive component. A similar threshold response is shown for several divalent cations, but is absent for monovalent cations. Response is absent for transistors using the inorganic semiconductor ZnO, or the similar organic semiconductor poly(3-hexylthiophene) (rrP3HT), instead of PBTTT. We assign innate cation sensitivity to residues of the organometallic Pd(0) complex used as catalyst in PBTTT synthesis which bears strong resemblance to typical metal chelating agents. Organometallic Pd(0) residues are absent from ZnO, and also from rrP3HT which is polymerised with a different type of catalyst. However, when Pd(0) complex is deliberately added to rrP3HT casting solutions, resulting OTFTs also display threshold response to a divalent cation. PMID:27343580

  4. Cordycepin promotes apoptosis by modulating the ERK-JNK signaling pathway via DUSP5 in renal cancer cells.

    Science.gov (United States)

    Hwang, Jung-Hoo; Joo, Jong Cheon; Kim, Dae Joon; Jo, Eunbi; Yoo, Hwa-Seung; Lee, Kyung-Bok; Park, Soo Jung; Jang, Ik-Soon

    2016-01-01

    Constitutive activation of extracellular signal regulated kinase (ERK)-Jun NH2-terminal kinase (JNK) signaling commonly occurs in tumors. The activation of ERK promotes cell proliferation, whereas that of JNK induces cell apoptosis. However, the apoptotic mechanism of ERK-JNK signaling in cancer is not well understood. Recently, we identified that apoptosis and activation of the JNK signaling pathway were induced after cordycepin treatment in human renal cancer, suggesting that JNK signaling might contribute to TK-10 cell apoptosis. We investigated the apoptotic effects of cordycepin by evaluating the activation of the ERK-JNK signaling pathway in renal cancer TK-10 cells. We found that cordycepin downregulated ERK and DUSP5, upregulated phosphorylated-JNK (p-JNK), and induced apoptosis. Moreover, we showed that siRNA-mediated inhibition of ERK downregulated DUSP5, whereas ERK overexpression upregulated DUSP5, and that DUSP5 knockdown by siRNA upregulated p-JNK. The JNK-specific inhibitor SP600125 upregulated nuclear translocation of β-catenin, and downregulated Dickkopf-1 (Dkk1), which has been shown to be a potent inhibitor of Wnt signaling. Dkk1 knockdown by siRNA upregulated nuclear β-catenin, suggesting the involvement of the Wnt/β-catenin signaling pathway. DUSP5 overexpression in TK-10 cells decreased p-JNK and increased nuclear β-catenin. The decreased Bax activation markedly protected against cordycepin-induced apoptosis. Bax subfamily proteins induced apoptosis through caspase-3. Taken together, we show that JNK signaling activation by cordycepin mediated ERK inhibition, which might have induced Bax translocation and caspase-3 activation via regulation of DUSP5 in TK-10 cells, thereby promoting the apoptosis of TK-10 cells. Targeting ERK-JNK signaling via the apoptotic effects of cordycepin could be a potential therapeutic strategy to treat renal cancer. PMID:27648363

  5. A Triterpenoid from Thalictrum fortunei Induces Apoptosis in BEL-7402 Cells Through the P53-Induced Apoptosis Pathway

    Directory of Open Access Journals (Sweden)

    Lvyi Chen

    2011-11-01

    Full Text Available Thalictrum fortunei S. Moore, a perennial plant distributed in the southeastern part of China, has been used in Traditional Chinese Medicine for thousands of years for its antitumor, antibacterial and immunoregulatory effects. In order to investigate the active components and the mechanism of the anti-tumor effects of Thalictrum fortunei, the growth inhibitory effects of eight triterpenoids isolated from the aerial parts of the plant on tumor cell lines were examined by 3-(4,5-dimethylthiazoy1-3,5-diphenyltetrazolium bromide (MTT assay. The MTT-assay results showed that the inhibitory activity of 3-O-β-D-glucopyranosyl-(1→4-β-D-fucopyranosyl(22S,24Z-cycloart-24-en-3β,22,26-triol 26-O-β-D-glucopyranoside (1 was stronger than that of the other seven tested triterpenoids on human hepatoma Bel-7402 cell line (Bel-7402, human colon lovo cells (LoVo, human non-small cells lung cancer NCIH-460 cells (NCIH-460 and human gastric carcinoma SGC-7901 cells (SGC-7901 after 48 h treatment in vitro, with the IC50 values of 66.4, 84.8, 73.5, 89.6 μM, respectively. Moreover, the antitumor mechanism of compound 1 on Bel-7402 cell was explored through nucleus dyeing, fluorescence assay, flow cytometry and western blot. The flow cytometric analysis results revealed that compound 1 caused apoptosis and mitochondrial membrane potential (MMP loss in Bel-7402 cells. A fluorescence assay indicated that intracellular reactive oxygen species (ROS were markedly provoked by compound 1 treatment compared to control cells. Immunoblot results showed that compound 1 significantly increased the expression levels of cleaved caspase-3, P53 and Bax protein, and decreased the expression level of Bcl-2 protein. These findings indicate that compound 1 inhibits the growth activity of tumor cells, probably through the P53 protein-induced apoptosis pathway.

  6. Activation of JNK by TPA promotes apoptosis via PKC pathway in gastric cancer cells

    Institute of Scientific and Technical Information of China (English)

    Yan Chen; Qiao Wu; Si-Yang Song; Wen-Jin Su

    2002-01-01

    AIM: JNK cascade plays an important role in cell proliferation, differentiation and apoptosis. However, the exact function of JNK cascade for apoptosis induction remains largely unknown. In this study, the role of JNK activation stimulated by TPA in the process of apoptosis induction and its signaling transduction pathway in gastric cancer cells were investigated and determined.METHODS: Expressions of mRNA and protein were detected by Northern blot and Western blot. Transcription activity was measured by transient transfection and CAT assay. Apoptotic cells were displayed through staining the nucleus with DAPI and were observed under fluorescence microscope. The apoptotic index was determined by counting 1000 cells randomly.RESULTS: JNK protein was stimulated rapidly by TPA, and reached its highest peak within 3 hr, then decreased in a time-dependent manner, but the expression level of JNK protein induced by TPA was always keeping higher than that in untreated cells. Similar pattern was seen in c-jun mRNA level induced by TPA. TPA significantly activated the transcriptional activity of activator protein-1 with a TPA-closedependent manner. Furthermore, activation of JNK was mediated through PKC pathway. Treatment of cells with PKC specific inhibitor, Wortmannin, led to repression of JNK even in the presence of TPA. More importantly, all these effects were associated with induction of apoptosis in gastric cancer cells. TPA inducted apoptosis obviously in gastric cancer cells. The apoptotic cells became smaller and rounded, and their nuclei became condensation and fragmentation with brightly stained chromatin. However, suppression of JNK by PKC specific inhibitor, Wortmannin, resulted in the decrease of apoptosis induced by TPA in a time-dependent manner, apoptotic index dramatically decreased from 32.56 % to 8.71%.CONCLUSION: TPA stimulates JNK cascade, including upregulation of JNK protein expression level and c-jun mRNA expression level, and activation of activator

  7. Protective effects of baicalin on amyloid beta 25-35- induced apoptosis in human neuroblastoma SH-SY5Y cells

    Institute of Scientific and Technical Information of China (English)

    Miao Geng; Hongyan Chen; Jianhua Wang; Yazhuo Hu; Jianwei Liu; Jing Liu; Jingkun Pan; Yuhong Gao

    2010-01-01

    Baicalin, a type of flavanoid, effectively prevents cellular apoptosis induced by various factors. However, little evidence is available regarding its role on amyloid β (Aβ) -induced neuronal apoptosis. The present study investigated the protective mechanisms of baicalin on Aβ-induced neuronal apoptosis. Flow cytometry and cation dye 5, 5', 6, 6'-tetrachloro-1, 1', 3, 3'-tetraethyl- benzimidazoly lcarbocyanine iodide (JC-1) were employed to measure mitochondrial membrane potential, and nitric oxide secretion and apoptotic-related factors, such as caspase-3, were comprehensively analyzed. Results demonstrated a protective effect of baicalin on Aβ-treated SH-SY5Y cell viability; the rate of apoptosis decreased, nitric oxide generation and expression of caspase-3 were effectively inhibited, and mitochondrial membrane potential was effectively protected. Baicalin inhibited Aβ-induced neuronal apoptosis via multiple targets and multiple pathways, such as the inhibition of free radical damage, reduction of caspase-3 expression, and protection of normal mitochondrial functions.

  8. Forging Colloidal Nanostructures via Cation Exchange Reactions

    Science.gov (United States)

    2016-01-01

    Among the various postsynthesis treatments of colloidal nanocrystals that have been developed to date, transformations by cation exchange have recently emerged as an extremely versatile tool that has given access to a wide variety of materials and nanostructures. One notable example in this direction is represented by partial cation exchange, by which preformed nanocrystals can be either transformed to alloy nanocrystals or to various types of nanoheterostructures possessing core/shell, segmented, or striped architectures. In this review, we provide an up to date overview of the complex colloidal nanostructures that could be prepared so far by cation exchange. At the same time, the review gives an account of the fundamental thermodynamic and kinetic parameters governing these types of reactions, as they are currently understood, and outlines the main open issues and possible future developments in the field. PMID:26891471

  9. Cationically polymerizable monomers derived from renewable sources

    Energy Technology Data Exchange (ETDEWEB)

    Crivello, J.V.

    1992-10-01

    The objectives of this project are to design and synthesize novel monomers which orginate from renewable biological sources and to carry out their rapid, efficient, pollution-free and energy efficient cationic polymerization to useful products under the influence of ultraviolet light or heat. A summary of the results of the past year's research on cationically polymerizable monomers derived from renewable sources is presented. Three major areas of investigation corresponding to the different classes of naturally occurring starting materials were investigated; epoxidized terpenes and natural rubber and vinyl ethers from alcohols and carbohydrates.

  10. Mixed cation effect in sodium aluminosilicate glasses

    DEFF Research Database (Denmark)

    Kjeldsen, Jonas; Smedskjær, Morten Mattrup; Mauro, John C.;

    , network structure, and the resistances associated with the deformation processes in mixed cation glasses by partially substituting magnesium for calcium and calcium for lithium in sodium aluminosilicate glasses. We use Raman and 27Al NMR spectroscopies to obtain insights into the structural...... and topological features of these glasses and we use AFM to quantify the resistances associated with each deformation process under Vickers indentation. We demonstrate that the mixed cation effect manifests itself as a maximum in the amount of bonded tetrahedral units and as a minimum in liquid fragility index...

  11. Cation Effect on Copper Chemical Mechanical Polishing

    Institute of Scientific and Technical Information of China (English)

    WANG Liang-Yong; LIU Bo; SONG Zhi-Tang; FENG Song-Lin

    2009-01-01

    We examine the effect of cations in solutions containing benzotriazole (BTA) and H2O2 on copper chemical mechanical polishing (CMP). On the base of atomic force microscopy (AFM) and material removal rate (MRR) results, it is found that ammonia shows the highest MRR as well as good surface after CMP, while KOH demon-strates the worst performance. These results reveal a mechanism that sma//molecules with lone-pairs rather than molecules with steric effect and common inorganic cations are better for copper CMP process, which is indirectly confirmed by open circuit potential (OCP).

  12. Cardiomyocytic apoptosis and heart failure

    Institute of Scientific and Technical Information of China (English)

    Quanzhou Feng

    2008-01-01

    Heart failure is a major disease seriously threatening human health.Once left ventricular dysfunction develops,cardiac function usually deteriorates and progresses to congestive heart failure in several months or years even if no factors which accelerate the deterioration repeatedly exist.Mechanism through which cardiac function continually deteriorates is still unclear.Cardiomyocytic apoptosis can occur in acute stage of ischemic heart diseases and the compensated stage of cardiac dysfunction.In this review,we summarize recent advances in understanding the role of cardiomyocytic apoptosis in heart failure.

  13. Monitoring apoptosis in real time.

    Science.gov (United States)

    Green, Allan M; Steinmetz, Neil D

    2002-01-01

    Many therapeutically active anticancer treatments exert their effect by the induction of apoptosis and necrosis. Serial biopsies in breast cancer patients have suggested that response to therapy correlates with early posttreatment increases in tumor apoptotic index. Radiolabeled technetium Tc 99m-recombinant human (rh) annexin V provides a noninvasive technique for imaging treatment-induced cell death. Annexin V is a naturally occurring human protein that binds avidly to membrane-associated phosphatidylserine (PS). PS is normally found only on the inner leaflet of the cell membrane double layer, but it is actively transported to the outer layer as an early event in apoptosis and becomes available for annexin binding. Annexin also gains access to PS as a result of the membrane fragmentation associated with necrosis. In vitro studies of apoptosis using fluorescein annexin have shown good correlation with assessments of apoptosis documented by nuclear DNA degradation and caspase activation. In vivo localization of intravenously administered Tc 99m-annexin V has been demonstrated in numerous preclinical models of apoptosis, including anti-Fas-mediated hepatic apoptosis, rejection of allogeneic heterotopic cardiac allografts, cyclophosphamide treatment of murine lymphoma, cyclophosphamide-induced apoptosis in bone marrow, and leukocyte apoptosis associated with abscess formation. Scintigraphic studies in humans using Tc 99m-rh annexin V have demonstrated the feasibility of imaging cell death in acute myocardial infarction, in tumors with a high apoptotic index, and in response to anti-tumor chemotherapy of non-small cell lung cancer, small-cell lung cancer, breast cancer, lymphoma, and sarcoma. Increased localization of Tc 99m-rh annexin V within 1 to 3 days of chemotherapy has been noted in some, but not all, subjects with these tumors. To date, most subjects showing increased Tc 99m-rh annexin V uptake after the first course of chemotherapy have shown objective

  14. Cation Selectivity in Biological Cation Channels Using Experimental Structural Information and Statistical Mechanical Simulation.

    Directory of Open Access Journals (Sweden)

    Justin John Finnerty

    Full Text Available Cation selective channels constitute the gate for ion currents through the cell membrane. Here we present an improved statistical mechanical model based on atomistic structural information, cation hydration state and without tuned parameters that reproduces the selectivity of biological Na+ and Ca2+ ion channels. The importance of the inclusion of step-wise cation hydration in these results confirms the essential role partial dehydration plays in the bacterial Na+ channels. The model, proven reliable against experimental data, could be straightforwardly used for designing Na+ and Ca2+ selective nanopores.

  15. Water adsorption on free cobalt cluster cations

    NARCIS (Netherlands)

    D.M. Kiawi; J.M. Bakker; J. Oomens; W.J. Buma; Z. Jamshidi; L. Visscher; L.B.F.M. Waters

    2015-01-01

    Cationic cobalt clusters complexed with water Con+-​H2O (n = 6-​20) are produced through laser ablation and investigated via IR multiple photon dissocn. (IR-​MPD) spectroscopy in the 200-​1700 cm-​1 spectral range. All spectra exhibit a resonance close to the 1595 cm-​1 frequency of the free water b

  16. Simultaneous anion and cation mobility in polypyrrole

    DEFF Research Database (Denmark)

    Skaarup, Steen; Bay, Lasse; Vidanapathirana, K.;

    2003-01-01

    Polypyrrole (PPy) polymer films permanently doped with large, immobile anion dodecyl benzene sulfonate (DBS) have been characterized by cyclic voltammetry in order to clarify the roles of cations and anions in the aqueous electrolyte as mobile ions in the film. Aqueous solutions of 0.05-0.1 M alk...

  17. Resonance raman studies of phenylcyclopropane radical cations

    NARCIS (Netherlands)

    Godbout, J.T.; Zuilhof, H.; Heim, G.; Gould, I.R.; Goodman, J.L.; Dinnocenzo, J.P.; Myers Kelley, A.

    2000-01-01

    Resonance Raman spectra of the radical cations of phenylcyclopropane and trans-1-phenyl-2-methylcyclopropane are reported. A near-UV pump pulse excites a photosensitizer which oxidizes the species of interest, and a visible probe pulse delayed by 35 ns obtains the spectrum of the radical ion. The tr

  18. Anionic/cationic complexes in hair care.

    Science.gov (United States)

    O'Lenick, Tony

    2011-01-01

    The formulation of cosmetic products is always more complicated than studying the individual components in aqueous solution. This is because there are numerous interactions between the components, which make the formulation truly more than the sum of the parts. This article will look at interactions between anionic and cationic surfactants and offer insights into how to use these interactions advantageously in making formulations.

  19. Cationic lipids and cationic ligands induce DNA helix denaturation: detection of single stranded regions by KMnO4 probing.

    Science.gov (United States)

    Prasad, T K; Gopal, Vijaya; Rao, N Madhusudhana

    2003-09-25

    Cationic lipids and cationic polymers are widely used in gene delivery. Using 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP) as a cationic lipid, we have investigated the stability of the DNA in DOTAP:DNA complexes by probing with potassium permanganate (KMnO4). Interestingly, thymidines followed by a purine showed higher susceptibility to cationic ligand-mediated melting. Similar studies performed with other water-soluble cationic ligands such as polylysine, protamine sulfate and polyethyleneimine also demonstrated melting of the DNA but with variations. Small cations such as spermine and spermidine and a cationic detergent, cetyl trimethylammonium bromide, also rendered the DNA susceptible to modification by KMnO4. The data presented here provide direct proof for melting of DNA upon interaction with cationic lipids. Structural changes subsequent to binding of cationic lipids/ligands to DNA may lead to instability and formation of DNA bubbles in double-stranded DNA.

  20. Downregulation of miRNA-30c and miR-203a is associated with hepatitis C virus core protein-induced epithelial–mesenchymal transition in normal hepatocytes and hepatocellular carcinoma cells

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Dongjing [Hepatobiliary and Enteric Surgery Research Center, Xiangya Hospital, Central South University, Changsha 410008 (China); Wu, Jilin, E-mail: 6296082@qq.com [Hepatobiliary and Enteric Surgery Research Center, Xiangya Hospital, Central South University, Changsha 410008 (China); Liu, Meizhou [Department of Medical Service, Shenzhen Second People' s Hospital, Shenzhen, Guangdong 518035 (China); Yin, Hui [Staff' s Hospital, Central South University, Changsha, Hunan 410078 (China); He, Jiantai [Hepatobiliary and Enteric Surgery Research Center, Xiangya Hospital, Central South University, Changsha 410008 (China); Zhang, Bo, E-mail: zhangbo8095@126.com [Department of Ultrasonography, Xiangya Hospital, Central South University, Changsha, Hunan 410008 (China)

    2015-09-04

    Hepatitis C virus (HCV) Core protein has been demonstrated to induce epithelial–mesenchymal transition (EMT) and is associated with cancer progression of hepatocellular carcinoma (HCC). However, how the Core protein regulates EMT is still unclear. In this study, HCV Core protein was overexpressed by an adenovirus. The protein levels of EMT markers were measured by Western blot. The xenograft animal model was established by inoculation of HepG2 cells. Results showed that ectopic expression of HCV core protein induced EMT in L02 hepatocytes and HepG2 tumor cells by upregulating vimentin, Sanl1, and Snal2 expression and downregulating E-cadherin expression. Moreover, Core protein downregulated miR-30c and miR-203a levels in L02 and HepG2 cells, but artificial expression of miR-30c and miR-203a reversed Core protein-induced EMT. Further analysis showed that ectopic expression of HCV core protein stimulated cell proliferation, inhibited apoptosis, and increased cell migration, whereas artificial expression of miR-30c and miR-203a significantly reversed the role of Core protein in these cell functions in L02 and HepG2 cells. In the HepG2 xenograft tumor models, artificial expression of miR-30c and miR-203a inhibited EMT and tumor growth. Moreover, L02 cells overexpressing Core protein can form tumors in nude mice. In HCC patients, HCV infection significantly shortened patients' survival time, and loss of miR-30c and miR-203 expression correlated with poor survival. In conclusion, HCV core protein downregulates miR-30c and miR-203a expression, which results in activation of EMT in normal hepatocytes and HCC tumor cells. The Core protein-activated-EMT is involved in the carcinogenesis and progression of HCC. Loss of miR-30c and miR-203a expression is a marker for the poor prognosis of HCC. - Highlights: • HCV core protein downregulates miR-30c and miR-203a expression. • Downregulation of miR-30c and miR-203a activates EMT. • Activated-EMT is involved in the

  1. Downregulation of miRNA-30c and miR-203a is associated with hepatitis C virus core protein-induced epithelial–mesenchymal transition in normal hepatocytes and hepatocellular carcinoma cells

    International Nuclear Information System (INIS)

    Hepatitis C virus (HCV) Core protein has been demonstrated to induce epithelial–mesenchymal transition (EMT) and is associated with cancer progression of hepatocellular carcinoma (HCC). However, how the Core protein regulates EMT is still unclear. In this study, HCV Core protein was overexpressed by an adenovirus. The protein levels of EMT markers were measured by Western blot. The xenograft animal model was established by inoculation of HepG2 cells. Results showed that ectopic expression of HCV core protein induced EMT in L02 hepatocytes and HepG2 tumor cells by upregulating vimentin, Sanl1, and Snal2 expression and downregulating E-cadherin expression. Moreover, Core protein downregulated miR-30c and miR-203a levels in L02 and HepG2 cells, but artificial expression of miR-30c and miR-203a reversed Core protein-induced EMT. Further analysis showed that ectopic expression of HCV core protein stimulated cell proliferation, inhibited apoptosis, and increased cell migration, whereas artificial expression of miR-30c and miR-203a significantly reversed the role of Core protein in these cell functions in L02 and HepG2 cells. In the HepG2 xenograft tumor models, artificial expression of miR-30c and miR-203a inhibited EMT and tumor growth. Moreover, L02 cells overexpressing Core protein can form tumors in nude mice. In HCC patients, HCV infection significantly shortened patients' survival time, and loss of miR-30c and miR-203 expression correlated with poor survival. In conclusion, HCV core protein downregulates miR-30c and miR-203a expression, which results in activation of EMT in normal hepatocytes and HCC tumor cells. The Core protein-activated-EMT is involved in the carcinogenesis and progression of HCC. Loss of miR-30c and miR-203a expression is a marker for the poor prognosis of HCC. - Highlights: • HCV core protein downregulates miR-30c and miR-203a expression. • Downregulation of miR-30c and miR-203a activates EMT. • Activated-EMT is involved in the

  2. Cation-cation interactions, magnetic communication and reactivity of the pentavalent uraniumion [U(NR)2]+

    Energy Technology Data Exchange (ETDEWEB)

    Spencer, Liam P [Los Alamos National Laboratory; Schelter, Eric J [Los Alamos National Laboratory; Boncella, James M [Los Alamos National Laboratory; Yang, Ping [Los Alamos National Laboratory; Gsula, Robyn L [NON LANL; Scott, Brian L [Los Alamos National Laboratory; Thompson, Joe D [Los Alamos National Laboratory; Kiplinger, Jacqueline L [Los Alamos National Laboratory; Batista, Enrique R [Los Alamos National Laboratory

    2009-01-01

    The dimeric bis(imido) uranium complex [{l_brace}U(NtBu)2(I)(tBu2bpy){r_brace}2] (see picture; U green, N blue, I red) has cation-cation interactions between [U(NR)2]+ ions. This f1-f1 system also displays f orbital communication between uranium(V) centers at low temperatures, and can be oxidized to generate uranium(VI) bis(imido) complexes.

  3. Structurally Distinct Cation Channelrhodopsins from Cryptophyte Algae.

    Science.gov (United States)

    Govorunova, Elena G; Sineshchekov, Oleg A; Spudich, John L

    2016-06-01

    Microbial rhodopsins are remarkable for the diversity of their functional mechanisms based on the same protein scaffold. A class of rhodopsins from cryptophyte algae show close sequence homology with haloarchaeal rhodopsin proton pumps rather than with previously known channelrhodopsins from chlorophyte (green) algae. In particular, both aspartate residues that occupy the positions of the chromophore Schiff base proton acceptor and donor, a hallmark of rhodopsin proton pumps, are conserved in these cryptophyte proteins. We expressed the corresponding polynucleotides in human embryonic kidney (HEK293) cells and studied electrogenic properties of the encoded proteins with whole-cell patch-clamp recording. Despite their lack of residues characteristic of the chlorophyte cation channels, these proteins are cation-conducting channelrhodopsins that carry out light-gated passive transport of Na(+) and H(+). These findings show that channel function in rhodopsins has evolved via multiple routes. PMID:27233115

  4. Radiation chemistry of aromatic dimer radical cations

    International Nuclear Information System (INIS)

    π-π Interactions of aromatic molecules are paid attention much in many fields, especially biology, chemistry, and applied physics, represented as protein, DNA, electron donor-accepter complexes, charge transfers, and self assembly molecules. Aromatic molecules including benzene rings are the simplest case to study the π-π interactions. To interpret the charge resonance (CR) structure in the dimer radical cations, spectroscopic and ESR methods have been carried out. The spectroscopic study on the dimer radical ion of molecules with two chromophores would be profitable to identify the electronic and configurational properties. In this article, dynamics of the dimer radical cation of benzenes, polystyrenes, and resist polymers is described on the basis of direct observation of CR band by the nanosecond pulse radiolysis and low temperature γ-radiolysis methods. (author)

  5. Alkaline earth cation extraction from acid solution

    Science.gov (United States)

    Dietz, Mark; Horwitz, E. Philip

    2003-01-01

    An extractant medium for extracting alkaline earth cations from an aqueous acidic sample solution is described as are a method and apparatus for using the same. The separation medium is free of diluent, free-flowing and particulate, and comprises a Crown ether that is a 4,4'(5')[C.sub.4 -C.sub.8 -alkylcyclohexano]18-Crown-6 dispersed on an inert substrate material.

  6. Cation Permeability in Soybean Aleurone Layer

    OpenAIRE

    Noda, Hiroko; Fukuda, Mitsuru

    1998-01-01

    The permeation of water and ions into bean seeds is essential for processing and cooking of beans. The permeability of cations, K, Na, Ca, and Mg ions, into soybean seed tissue, especially aleurone layer, during water uptake was investigated to characterize the ion permeation into soybeans. Aleurone layers and seed coats contained relatively high concentration of endogenous K and Ca ions, and endogenous Ca ion, respectively. The amounts of Ca ion entered seed coats and aleurone layers were gr...

  7. Low cation coordination in oxide melts

    Energy Technology Data Exchange (ETDEWEB)

    Skinner, Lawrie [State University of New York, Stony Brook; Benmore, Chris J [Argonne National Laboratory (ANL); Du, Jincheng [University of North Texas; Weber, Richard [Argonne National Laboratory (ANL); Neuefeind, Joerg C [ORNL; Tumber, Sonia [Materials Development, Inc., Evanston, IL; Parise, John B [Stony Brook University (SUNY)

    2014-01-01

    The complete set of Faber-Ziman partial pair distribution functions for a rare earth oxide liquid were measured for the first time by combining aerodynamic levitation, neutron diffraction, high energy x-ray diffraction and isomorphic substitution using Y2 O3 and Ho2 O3 melts. The average Y- O coordination is measured to be 5.5(2), which is significantly less than the octahedral coordination of crystalline Y2 O3 (or Ho2 O3 ). Investigation of high temperature La2 O3 , ZrO2 , SiO2 , and Al2 O3 melts by x-ray diffraction and molecular dynamics simulations also show lower-than-crystal cation- oxygen coordination. These measurements suggest a general trend towards lower M-O coordination compared to their crystalline counterparts. It is found that this coordination number drop is larger for lower field strength, larger radius cations and is negligible for high field strength (network forming) cations. These findings have broad implications for predicting the local structure and related physical properties of metal-oxide melts and oxide glasses.

  8. Low Cation Coordination in Oxide Melts

    Science.gov (United States)

    Skinner, L. B.; Benmore, C. J.; Weber, J. K. R.; Du, J.; Neuefeind, J.; Tumber, S. K.; Parise, J. B.

    2014-04-01

    The complete set of partial pair distribution functions for a rare earth oxide liquid are measured by combining aerodynamic levitation, neutron and x-ray diffraction on Y2O3, and Ho2O3 melts at 2870 K. The average Y-O (or Ho-O) coordination of these isomorphic melts is measured to be 5.5(2), which is significantly less than the octahedral coordination of crystalline Y2O3 (or Ho2O3). Investigation of La2O3, ZrO2, and Al2O3 melts by x-ray diffraction and molecular dynamics simulations also show lower-than-crystal cation-oxygen coordination. These measurements suggest a general trend towards lower coordination compared to their crystalline counterparts. It is found that the coordination drop is larger for lower field strength, larger radius cations and is negligible for high field strength (network forming) cations, such as SiO2. These findings have broad implications for predicting the local structure and related physical properties of metal-oxide melts and oxide glasses.

  9. Limited data speaker identification

    Indian Academy of Sciences (India)

    H S Jayanna; S R Mahadeva Prasanna

    2010-10-01

    In this paper, the task of identifying the speaker using limited training and testing data is addressed. Speaker identification system is viewed as four stages namely, analysis, feature extraction, modelling and testing. The speaker identification performance depends on the techniques employed in these stages. As demonstrated by different experiments, in case of limited training and testing data condition, owing to less data, existing techniques in each stage will not provide good performance. This work demonstrates the following: multiple frame size and rate (MFSR) analysis provides improvement in the analysis stage, combination of mel frequency cepstral coefficients (MFCC), its temporal derivatives $(\\Delta,\\Delta \\Delta)$, linear prediction residual (LPR) and linear prediction residual phase (LPRP) features provides improvement in the feature extraction stage and combination of learning vector quantization (LVQ) and gaussian mixture model – universal background model (GMM–UBM) provides improvement in the modelling stage. The performance is further improved by integrating the proposed techniques at the respective stages and combining the evidences from them at the testing stage. To achieve this, we propose strength voting (SV), weighted borda count (WBC) and supporting systems (SS) as combining methods at the abstract, rank and measurement levels, respectively. Finally, the proposed hierarchical combination (HC) method integrating these three methods provides significant improvement in the performance. Based on these explorations, this work proposes a scheme for speaker identification under limited training and testing data.

  10. Differential effect of HOE642 on two separate monovalent cation transporters in the human red cell membrane

    DEFF Research Database (Denmark)

    Bernhardt, Ingolf; Weiss, Erwin; Robinson, Hannah C;

    2007-01-01

    Residual K(+) fluxes in red blood cells can be stimulated in conditions of low ionic strength. Previous studies have identified both the non-selective, voltage-dependent cation (NSVDC) channel and the K(+)(Na(+))/H(+) exchanger as candidate pathways mediating this effect, although it is possible...... showed that HOE642 exerted differential effects on the NSVDC channel and the K(+)(Na(+))/H(+) exchanger, confirming that the salt loss observed in low ionic strength solutions represents contributions from at least two independent ion transport pathways. The findings are discussed in the context of red...... blood cell apoptosis (eryptosis) and disease....

  11. Apoptosis in irradiated murine tumors.

    Science.gov (United States)

    Stephens, L C; Ang, K K; Schultheiss, T E; Milas, L; Meyn, R E

    1991-09-01

    Early radiation responses of transplantable murine ovarian (OCaI) and hepatocellular (HCaI) carcinomas were examined at 6, 24, 48, 96, and 144 h after single photon doses of 25, 35, or 45 Gy. Previous studies using tumor growth delay and tumor radiocurability assays had shown OCaI tumors to be relatively radiosensitive and HCaI tumors to be radioresistant. At 6 h, approximately 20% of nuclei in OCaI tumors showed aberrations characteristic of cell death by apoptosis. This contrasted to an incidence of 3% in HCaI tumors. Mitotic activity was eliminated in OCaI tumors but was only transiently suppressed in HCaI tumors. At 24-96 h, OCaI tumors continued to display apoptosis and progressive necrosis, whereas HCaI tumors responded by exhibiting marked pleomorphism. Factors other than mitotic activity may influence tumor radiosensitivity, and one of these may be susceptibility to induction of apoptosis (programmed cell death), because this was a prominent early radiation response by the radiosensitive OCaI tumors.

  12. Apoptosis in irradiated murine tumors.

    Science.gov (United States)

    Stephens, L C; Ang, K K; Schultheiss, T E; Milas, L; Meyn, R E

    1991-09-01

    Early radiation responses of transplantable murine ovarian (OCaI) and hepatocellular (HCaI) carcinomas were examined at 6, 24, 48, 96, and 144 h after single photon doses of 25, 35, or 45 Gy. Previous studies using tumor growth delay and tumor radiocurability assays had shown OCaI tumors to be relatively radiosensitive and HCaI tumors to be radioresistant. At 6 h, approximately 20% of nuclei in OCaI tumors showed aberrations characteristic of cell death by apoptosis. This contrasted to an incidence of 3% in HCaI tumors. Mitotic activity was eliminated in OCaI tumors but was only transiently suppressed in HCaI tumors. At 24-96 h, OCaI tumors continued to display apoptosis and progressive necrosis, whereas HCaI tumors responded by exhibiting marked pleomorphism. Factors other than mitotic activity may influence tumor radiosensitivity, and one of these may be susceptibility to induction of apoptosis (programmed cell death), because this was a prominent early radiation response by the radiosensitive OCaI tumors. PMID:1886987

  13. Alkali cation specific adsorption onto fcc(111) transition metal electrodes.

    Science.gov (United States)

    Mills, J N; McCrum, I T; Janik, M J

    2014-07-21

    The presence of alkali cations in electrolyte solutions is known to impact the rate of electrocatalytic reactions, though the mechanism of such impact is not conclusively determined. We use density functional theory (DFT) to examine the specific adsorption of alkali cations to fcc(111) electrode surfaces, as specific adsorption may block catalyst sites or otherwise impact surface catalytic chemistry. Solvation of the cation-metal surface structure was investigated using explicit water models. Computed equilibrium potentials for alkali cation adsorption suggest that alkali and alkaline earth cations will specifically adsorb onto Pt(111) and Pd(111) surfaces in the potential range of hydrogen oxidation and hydrogen evolution catalysis in alkaline solutions.

  14. Induction of apoptosis in human cancer cells by targeting mitochondria with gold nanoparticles

    Science.gov (United States)

    Mkandawire, M. M.; Lakatos, M.; Springer, A.; Clemens, A.; Appelhans, D.; Krause-Buchholz, U.; Pompe, W.; Rödel, G.; Mkandawire, M.

    2015-06-01

    A major challenge in designing cancer therapies is the induction of cancer cell apoptosis, although activation of intrinsic apoptotic pathways by targeting gold nanoparticles to mitochondria is promising. We report an in vitro procedure targeting mitochondria with conjugated gold nanoparticles and investigating effects on apoptosis induction in the human breast cancer cell line Jimt-1. Gold nanoparticles were conjugated to a variant of turbo green fluorescent protein (mitoTGFP) harbouring an amino-terminal mitochondrial localization signal. Au nanoparticle conjugates were further complexed with cationic maltotriose-modified poly(propylene imine) third generation dendrimers. Fluorescence and transmission electron microscopy revealed that Au nanoparticle conjugates were directed to mitochondria upon transfection, causing partial rupture of the outer mitochondrial membrane, triggering cell death. The ability to target Au nanoparticles into mitochondria of breast cancer cells and induce apoptosis reveals an alternative application of Au nanoparticles in photothermal therapy of cancer.A major challenge in designing cancer therapies is the induction of cancer cell apoptosis, although activation of intrinsic apoptotic pathways by targeting gold nanoparticles to mitochondria is promising. We report an in vitro procedure targeting mitochondria with conjugated gold nanoparticles and investigating effects on apoptosis induction in the human breast cancer cell line Jimt-1. Gold nanoparticles were conjugated to a variant of turbo green fluorescent protein (mitoTGFP) harbouring an amino-terminal mitochondrial localization signal. Au nanoparticle conjugates were further complexed with cationic maltotriose-modified poly(propylene imine) third generation dendrimers. Fluorescence and transmission electron microscopy revealed that Au nanoparticle conjugates were directed to mitochondria upon transfection, causing partial rupture of the outer mitochondrial membrane, triggering cell

  15. A Quantitative Theoretical Framework For Protein-Induced Fluorescence Enhancement–Förster-Type Resonance Energy Transfer (PIFE-FRET)

    Science.gov (United States)

    2016-01-01

    Single-molecule, protein-induced fluorescence enhancement (PIFE) serves as a molecular ruler at molecular distances inaccessible to other spectroscopic rulers such as Förster-type resonance energy transfer (FRET) or photoinduced electron transfer. In order to provide two simultaneous measurements of two distances on different molecular length scales for the analysis of macromolecular complexes, we and others recently combined measurements of PIFE and FRET (PIFE-FRET) on the single molecule level. PIFE relies on steric hindrance of the fluorophore Cy3, which is covalently attached to a biomolecule of interest, to rotate out of an excited-state trans isomer to the cis isomer through a 90° intermediate. In this work, we provide a theoretical framework that accounts for relevant photophysical and kinetic parameters of PIFE-FRET, show how this framework allows the extraction of the fold-decrease in isomerization mobility from experimental data, and show how these results provide information on changes in the accessible volume of Cy3. The utility of this model is then demonstrated for experimental results on PIFE-FRET measurement of different protein–DNA interactions. The proposed model and extracted parameters could serve as a benchmark to allow quantitative comparison of PIFE effects in different biological systems. PMID:27184889

  16. Identification of avocado (Persea americana) root proteins induced by infection with the oomycete Phytophthora cinnamomi using a proteomic approach.

    Science.gov (United States)

    Acosta-Muñiz, Carlos H; Escobar-Tovar, Lina; Valdes-Rodríguez, Silvia; Fernández-Pavia, Silvia; Arias-Saucedo, Luis J; de la Cruz Espindola Barquera, Maria; Gómez Lim, Miguel Á

    2012-01-01

    Avocado root rot, caused by Phytophthora cinnamomi, is the most important disease that limits avocado production. A proteomic approach was employed to identify proteins that are upregulated by infection with P. cinnamomi. Different proteins were shown to be differentially expressed after challenge with the pathogen by two-dimensional (2-D) gel electrophoresis. A densitometric evaluation of protein expression indicated differential regulation during the time-course analyzed. Some proteins induced in response to the infection were identified by standard peptide mass fingerprinting using matrix-assisted laser desorption/ionization-time of flight-mass spectrometry and sequencing by MALDI LIFT-TOF/TOF tandem mass spectrometry. Of the 400 protein spots detected on 2-D gels, 21 seemed to change in abundance by 3 hours after infection. Sixteen proteins were upregulated, 5 of these were only detected in infected roots and 11 showed an increased abundance. Among the differentially expressed proteins identified are homologs to isoflavone reductase, glutathione S-transferase, several abscisic acid stress-ripening proteins, cinnamyl alcohol dehydrogenase, cinnamoyl-CoA reductase, cysteine synthase and quinone reductase. A 17.3-kDa small heat-shock protein and a glycine-rich RNA-binding protein were identified as downregulated. Our group is the first to report on gene induction in response to oomycete infection in roots from avocado, using proteomic techniques.

  17. Förster resonance energy transfer and protein-induced fluorescence enhancement as synergetic multi-scale molecular rulers

    Science.gov (United States)

    Ploetz, Evelyn; Lerner, Eitan; Husada, Florence; Roelfs, Martin; Chung, Sangyoon; Hohlbein, Johannes; Weiss, Shimon; Cordes, Thorben

    2016-09-01

    Advanced microscopy methods allow obtaining information on (dynamic) conformational changes in biomolecules via measuring a single molecular distance in the structure. It is, however, extremely challenging to capture the full depth of a three-dimensional biochemical state, binding-related structural changes or conformational cross-talk in multi-protein complexes using one-dimensional assays. In this paper we address this fundamental problem by extending the standard molecular ruler based on Förster resonance energy transfer (FRET) into a two-dimensional assay via its combination with protein-induced fluorescence enhancement (PIFE). We show that donor brightness (via PIFE) and energy transfer efficiency (via FRET) can simultaneously report on e.g., the conformational state of double stranded DNA (dsDNA) following its interaction with unlabelled proteins (BamHI, EcoRV, and T7 DNA polymerase gp5/trx). The PIFE-FRET assay uses established labelling protocols and single molecule fluorescence detection schemes (alternating-laser excitation, ALEX). Besides quantitative studies of PIFE and FRET ruler characteristics, we outline possible applications of ALEX-based PIFE-FRET for single-molecule studies with diffusing and immobilized molecules. Finally, we study transcription initiation and scrunching of E. coli RNA-polymerase with PIFE-FRET and provide direct evidence for the physical presence and vicinity of the polymerase that causes structural changes and scrunching of the transcriptional DNA bubble.

  18. Förster resonance energy transfer and protein-induced fluorescence enhancement as synergetic multi-scale molecular rulers.

    Science.gov (United States)

    Ploetz, Evelyn; Lerner, Eitan; Husada, Florence; Roelfs, Martin; Chung, SangYoon; Hohlbein, Johannes; Weiss, Shimon; Cordes, Thorben

    2016-01-01

    Advanced microscopy methods allow obtaining information on (dynamic) conformational changes in biomolecules via measuring a single molecular distance in the structure. It is, however, extremely challenging to capture the full depth of a three-dimensional biochemical state, binding-related structural changes or conformational cross-talk in multi-protein complexes using one-dimensional assays. In this paper we address this fundamental problem by extending the standard molecular ruler based on Förster resonance energy transfer (FRET) into a two-dimensional assay via its combination with protein-induced fluorescence enhancement (PIFE). We show that donor brightness (via PIFE) and energy transfer efficiency (via FRET) can simultaneously report on e.g., the conformational state of double stranded DNA (dsDNA) following its interaction with unlabelled proteins (BamHI, EcoRV, and T7 DNA polymerase gp5/trx). The PIFE-FRET assay uses established labelling protocols and single molecule fluorescence detection schemes (alternating-laser excitation, ALEX). Besides quantitative studies of PIFE and FRET ruler characteristics, we outline possible applications of ALEX-based PIFE-FRET for single-molecule studies with diffusing and immobilized molecules. Finally, we study transcription initiation and scrunching of E. coli RNA-polymerase with PIFE-FRET and provide direct evidence for the physical presence and vicinity of the polymerase that causes structural changes and scrunching of the transcriptional DNA bubble. PMID:27641327

  19. A Quantitative Theoretical Framework For Protein-Induced Fluorescence Enhancement-Förster-Type Resonance Energy Transfer (PIFE-FRET).

    Science.gov (United States)

    Lerner, Eitan; Ploetz, Evelyn; Hohlbein, Johannes; Cordes, Thorben; Weiss, Shimon

    2016-07-01

    Single-molecule, protein-induced fluorescence enhancement (PIFE) serves as a molecular ruler at molecular distances inaccessible to other spectroscopic rulers such as Förster-type resonance energy transfer (FRET) or photoinduced electron transfer. In order to provide two simultaneous measurements of two distances on different molecular length scales for the analysis of macromolecular complexes, we and others recently combined measurements of PIFE and FRET (PIFE-FRET) on the single molecule level. PIFE relies on steric hindrance of the fluorophore Cy3, which is covalently attached to a biomolecule of interest, to rotate out of an excited-state trans isomer to the cis isomer through a 90° intermediate. In this work, we provide a theoretical framework that accounts for relevant photophysical and kinetic parameters of PIFE-FRET, show how this framework allows the extraction of the fold-decrease in isomerization mobility from experimental data, and show how these results provide information on changes in the accessible volume of Cy3. The utility of this model is then demonstrated for experimental results on PIFE-FRET measurement of different protein-DNA interactions. The proposed model and extracted parameters could serve as a benchmark to allow quantitative comparison of PIFE effects in different biological systems. PMID:27184889

  20. Respiratory syncytial virus matrix protein induces lung epithelial cell cycle arrest through a p53 dependent pathway.

    Science.gov (United States)

    Bian, Tao; Gibbs, John D; Örvell, Claes; Imani, Farhad

    2012-01-01

    Respiratory syncytial virus (RSV) is the major cause of viral respiratory infections in children. Our previous study showed that the RSV infection induced lung epithelial cell cycle arrest, which enhanced virus replication. To address the mechanism of RSV-induced cell cycle arrest, we examined the contribution of RSV-matrix (RSV-M) protein. In this report, we show that in both the A549 cell line and primary human bronchial epithelial (PHBE) cells, transfection with RSV-M protein caused the cells to proliferate at a slower rate than in control cells. The cell cycle analysis showed that RSV-M protein induced G1 phase arrest in A549 cells, and G1 and G2/M phase arrest in PHBE cells. Interestingly, RSV-M expression induced p53 and p21 accumulation and decreased phosphorylation of retinoblastoma protein (Rb). Further, induction of cell cycle arrest by RSV-M was not observed in a p53-deficient epithelial cell line (H1299). However, cell cycle arrest was restored after transfection of p53 cDNA into H1299 cells. Taken together, these results indicate that RSV-M protein regulates lung epithelial cell cycle through a p53-dependent pathway, which enhances RSV replication. PMID:22662266

  1. Respiratory syncytial virus matrix protein induces lung epithelial cell cycle arrest through a p53 dependent pathway.

    Directory of Open Access Journals (Sweden)

    Tao Bian

    Full Text Available Respiratory syncytial virus (RSV is the major cause of viral respiratory infections in children. Our previous study showed that the RSV infection induced lung epithelial cell cycle arrest, which enhanced virus replication. To address the mechanism of RSV-induced cell cycle arrest, we examined the contribution of RSV-matrix (RSV-M protein. In this report, we show that in both the A549 cell line and primary human bronchial epithelial (PHBE cells, transfection with RSV-M protein caused the cells to proliferate at a slower rate than in control cells. The cell cycle analysis showed that RSV-M protein induced G1 phase arrest in A549 cells, and G1 and G2/M phase arrest in PHBE cells. Interestingly, RSV-M expression induced p53 and p21 accumulation and decreased phosphorylation of retinoblastoma protein (Rb. Further, induction of cell cycle arrest by RSV-M was not observed in a p53-deficient epithelial cell line (H1299. However, cell cycle arrest was restored after transfection of p53 cDNA into H1299 cells. Taken together, these results indicate that RSV-M protein regulates lung epithelial cell cycle through a p53-dependent pathway, which enhances RSV replication.

  2. Characterization of vegetative storage protein (VSP) and low molecular proteins induced by water deficit in stolon of white clover.

    Science.gov (United States)

    Lee, Bok-Rye; Lee, Dong-Gi; Avice, Jean-Christophe; Kim, Tae-Hwan

    2014-01-01

    In stolon of white clover (Trifolium repens L.), the 17.3 kDa protein has been newly identified as a vegetative storage protein (VSP) which has preponderant roles in N accumulation and mobilization to sustain growth when capacity of N uptake is strongly reduced. To characterize the water deficit effect on this protein, the kinetic pattern of soluble protein, SDS-PAGE, Western blotting, and proteomic analysis was studied in the stolon of white clover during 28 days of water-deficit. Water deficit led to decrease protein concentration. SDS-PAGE revealed that two major proteins of 17.3 and 16 kDa were accumulated to high level in response to water stress. These proteins cross-reacted positively with antibodies raised against the 17.3 kDa VSP, a protein which shared biochemical features with stress proteins implied in dehydration tolerance. Using two-dimensional electrophoresis (2-DE) gel and matrix-assisted laser desorption/ionization time-of-flight mass spectrometer (MALDI-TOF-MS) analysis, it was demonstrated that 19.5 and 17.3 kDa protein spots were up-regulated by water stress, and both spots were identical to nucleoside diphosphate kinase (NDPK) and lipid transfer proteins (LTPs), respectively. These results suggest that low molecular proteins induced by water-deficit in the stolon of white clover act as an alternative N reserves or play significant roles in plant protection against water-deficit stress. PMID:24299955

  3. A Quantitative Theoretical Framework For Protein-Induced Fluorescence Enhancement-Förster-Type Resonance Energy Transfer (PIFE-FRET).

    Science.gov (United States)

    Lerner, Eitan; Ploetz, Evelyn; Hohlbein, Johannes; Cordes, Thorben; Weiss, Shimon

    2016-07-01

    Single-molecule, protein-induced fluorescence enhancement (PIFE) serves as a molecular ruler at molecular distances inaccessible to other spectroscopic rulers such as Förster-type resonance energy transfer (FRET) or photoinduced electron transfer. In order to provide two simultaneous measurements of two distances on different molecular length scales for the analysis of macromolecular complexes, we and others recently combined measurements of PIFE and FRET (PIFE-FRET) on the single molecule level. PIFE relies on steric hindrance of the fluorophore Cy3, which is covalently attached to a biomolecule of interest, to rotate out of an excited-state trans isomer to the cis isomer through a 90° intermediate. In this work, we provide a theoretical framework that accounts for relevant photophysical and kinetic parameters of PIFE-FRET, show how this framework allows the extraction of the fold-decrease in isomerization mobility from experimental data, and show how these results provide information on changes in the accessible volume of Cy3. The utility of this model is then demonstrated for experimental results on PIFE-FRET measurement of different protein-DNA interactions. The proposed model and extracted parameters could serve as a benchmark to allow quantitative comparison of PIFE effects in different biological systems.

  4. Förster resonance energy transfer and protein-induced fluorescence enhancement as synergetic multi-scale molecular rulers

    Science.gov (United States)

    Ploetz, Evelyn; Lerner, Eitan; Husada, Florence; Roelfs, Martin; Chung, SangYoon; Hohlbein, Johannes; Weiss, Shimon; Cordes, Thorben

    2016-01-01

    Advanced microscopy methods allow obtaining information on (dynamic) conformational changes in biomolecules via measuring a single molecular distance in the structure. It is, however, extremely challenging to capture the full depth of a three-dimensional biochemical state, binding-related structural changes or conformational cross-talk in multi-protein complexes using one-dimensional assays. In this paper we address this fundamental problem by extending the standard molecular ruler based on Förster resonance energy transfer (FRET) into a two-dimensional assay via its combination with protein-induced fluorescence enhancement (PIFE). We show that donor brightness (via PIFE) and energy transfer efficiency (via FRET) can simultaneously report on e.g., the conformational state of double stranded DNA (dsDNA) following its interaction with unlabelled proteins (BamHI, EcoRV, and T7 DNA polymerase gp5/trx). The PIFE-FRET assay uses established labelling protocols and single molecule fluorescence detection schemes (alternating-laser excitation, ALEX). Besides quantitative studies of PIFE and FRET ruler characteristics, we outline possible applications of ALEX-based PIFE-FRET for single-molecule studies with diffusing and immobilized molecules. Finally, we study transcription initiation and scrunching of E. coli RNA-polymerase with PIFE-FRET and provide direct evidence for the physical presence and vicinity of the polymerase that causes structural changes and scrunching of the transcriptional DNA bubble. PMID:27641327

  5. High glucose induced oxidative stress and apoptosis in cardiac microvascular endothelial cells are regulated by FoxO3a.

    Directory of Open Access Journals (Sweden)

    Chaoming Peng

    Full Text Available AIM: Cardiac microvascular endothelial cells (CMECs dysfunction contributes to cardiovascular complications in diabetes, whereas, the underlying mechanism is not fully clarified. FoxO transcription factors are involved in apoptosis and reactive oxygen species (ROS production. Therefore, the present study was designed to elucidate the potential role of FoxO3a on the CMECs injury induced by high glucose. MATERIALS AND METHODS: CMECs were isolated from hearts of adult rats and cultured in normal or high glucose medium for 6 h, 12 h and 24 h respectively. To down-regulate FoxO3a expression, CMECs were transfected with FoxO3a siRNA. ROS accumulation and apoptosis in CMECs were assessed by dihydroethidine (DHE staining and TUNEL assay respectively. Moreover, the expressions of Akt, FoxO3a, Bim and BclxL in CMECs were assessed by Western blotting assay. RESULTS: ROS accumulation in CMECs was significantly increased after high glucose incubation for 6 to 24 h. Meanwhile, high glucose also increased apoptosis in CMECs, correlated with decreased the phosphorylation expressions of Akt and FoxO3a. Moreover, high glucose incubation increased the expression of Bim, whereas increased anti-apoptotic protein BclxL. Furthermore, siRNA target FoxO3a silencing enhanced the ROS accumulation, whereas suppressed apoptosis in CMECs. FoxO3a silencing also abolished the disturbance of Bcl-2 proteins induced by high glucose in CMECs. CONCLUSION: Our data provide evidence that high glucose induced FoxO3a activation which suppressed ROS accumulation, and in parallel, resulted in apoptosis of CMECs.

  6. Molecular signal transduction in vascular cell apoptosis

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Apoptosis is a form of genetically programmed cell death, which plays a key role in regulation of cellularity in a variety of tissue and cell types including the cardiovascular tissues. Under both physiological and pathophysiological conditions, various biophysiological and biochemical factors, including mechanical forces, reactive oxygen and nitrogen species, cytokines, growth factors, oxidized lipoproteins, etc., may influence apoptosis of vascular cells. The Fas/Fas ligand/caspase death-signaling pathway, Bcl-2 protein family/mitochondria, the tumor suppressive gene p53, and the proto-oncogene c-myc may be activated in atherosclerotic lesions, and mediates vascular apoptosis during the development of atherosclerosis. Abnormal expression and dysfunction of these apoptosis-regulating genes may attenuate or accelerate vascular cell apoptosis and affect the integrity and stability of atherosclerotic plaques. Clarification of the molecular mechanism that regulates apoptosis may help design a new strategy for treatment of atherosclerosis and its major complication, the acute vascular syndromes.

  7. Apoptosis in normal oral tissues and odontogenesis

    OpenAIRE

    Ruchita Bali; Akhilesh Chandra; Renuka Verma

    2013-01-01

    Programmed cell death or apoptosis is considered a vital component of various processes including normal cell turnover, proper development and functioning of the immune system, hormone-dependent atrophy, embryonic development, and chemical-induced cell death. Inappropriate apoptosis (either too little or too much) is a factor in many human conditions including neurodegenerative diseases, ischemic damage, autoimmune disorders, and many types of cancers. The process of apoptosis is generally ch...

  8. Apoptosis: A Review of Programmed Cell Death

    OpenAIRE

    Elmore, Susan

    2007-01-01

    The process of programmed cell death, or apoptosis, is generally characterized by distinct morphological characteristics and energy-dependent biochemical mechanisms. Apoptosis is considered a vital component of various processes including normal cell turnover, proper development and functioning of the immune system, hormone-dependent atrophy, embryonic development and chemical-induced cell death. Inappropriate apoptosis (either too little or too much) is a factor in many human conditions incl...

  9. Complex Macromolecular Architectures by Living Cationic Polymerization

    KAUST Repository

    Alghamdi, Reem D.

    2015-05-01

    Poly (vinyl ether)-based graft polymers have been synthesized by the combination of living cationic polymerization of vinyl ethers with other living or controlled/ living polymerization techniques (anionic and ATRP). The process involves the synthesis of well-defined homopolymers (PnBVE) and co/terpolymers [PnBVE-b-PCEVE-b-PSiDEGVE (ABC type) and PSiDEGVE-b-PnBVE-b-PSiDEGVE (CAC type)] by sequential living cationic polymerization of n-butyl vinyl ether (nBVE), 2-chloroethyl vinyl ether (CEVE) and tert-butyldimethylsilyl ethylene glycol vinyl ether (SiDEGVE), using mono-functional {[n-butoxyethyl acetate (nBEA)], [1-(2-chloroethoxy) ethyl acetate (CEEA)], [1-(2-(2-(t-butyldimethylsilyloxy)ethoxy) ethoxy) ethyl acetate (SiDEGEA)]} or di-functional [1,4-cyclohexanedimethanol di(1-ethyl acetate) (cHMDEA), (VEMOA)] initiators. The living cationic polymerizations of those monomers were conducted in hexane at -20 0C using Et3Al2Cl3 (catalyst) in the presence of 1 M AcOEt base.[1] The PCEVE segments of the synthesized block terpolymers were then used to react with living macroanions (PS-DPE-Li; poly styrene diphenyl ethylene lithium) to afford graft polymers. The quantitative desilylation of PSiDEGVE segments by n-Bu4N+F- in THF at 0 °C led to graft co- and terpolymers in which the polyalcohol is the outer block. These co-/terpolymers were subsequently subjected to “grafting-from” reactions by atom transfer radical polymerization (ATRP) of styrene to afford more complex macromolecular architectures. The base assisted living cationic polymerization of vinyl ethers were also used to synthesize well-defined α-hydroxyl polyvinylether (PnBVE-OH). The resulting polymers were then modified into an ATRP macro-initiator for the synthesis of well-defined block copolymers (PnBVE-b-PS). Bifunctional PnBVE with terminal malonate groups was also synthesized and used as a precursor for more complex architectures such as H-shaped block copolymer by “grafting-from” or

  10. Aggregate Formed by a Cationic Fluorescence Probe

    Institute of Scientific and Technical Information of China (English)

    TIAN, Juan; SANG, Da-Yong; JI, Guo-Zhen

    2007-01-01

    The aggregation behavior of a cationic fluorescence probe 10-(4,7,10,13,16-pentaoxa-1-azacyclooctadecyl-methyl)anthracen-9-ylmethyl dodecanoate (1) was observed and studied by a fluorescence methodology in acidic and neutral conditions. By using the Py scale, differences between simple aggregates and micelles have been discussed. The stability of simple aggregates was discussed in terms of hydrophobic interaction and electrostatic repulsion. The absence of excimer emission of the anthrancene moiety of probe 1 in neutral condition was attributed to the photoinduced electron transfer mechanism instead of photodimerization.

  11. HIV-1 protein induced modulation of primary human osteoblast differentiation and function via a Wnt/β-catenin-dependent mechanism.

    LENUS (Irish Health Repository)

    Butler, Joseph S

    2013-02-01

    HIV infection is associated with metabolic bone disease resulting in bone demineralization and reduced bone mass. The molecular mechanisms driving this disease process have yet to be elucidated. Wnt\\/β-catenin signaling plays a key role in bone development and remodeling. We attempted to determine the effects of the HIV-1 protein, gp120, on Wnt\\/β-catenin signaling at an intracellular and transcriptional level in primary human osteoblasts (HOBs). This work, inclusive of experimental controls, was part of a greater project assessing the effects of a variety of different agents on Wnt\\/β-catenin signaling (BMC Musculoskelet Disord 2010;11:210).We examined the phenotypic effects of silencing and overexpressing the Wnt antagonist, Dickkopf-1 (Dkk1) in HOBs treated with gp120. HOBs exposed to gp120 displayed a significant reduction in alkaline phosphatase activity (ALP) activity and cell proliferation and increased cellular apoptosis over a 48 h time course. Immunocytochemistry demonstrated a significant reduction in intracytosolic and intranuclear β-catenin in response to HIV-1 protein exposure. These changes were associated with a reduction of TCF\\/LEF-mediated transcription, the transcriptional outcome of canonical Wnt β-catenin signaling. Silencing Dkk1 expression in HOBs exposed to gp120 resulted in increased ALP activity and cell proliferation, and decreased cellular apoptosis relative to scrambled control. Dkk1 overexpression exacerbated the inhibitory effect of gp120 on HOB function, with decreases in ALP activity and cell proliferation and increased cellular apoptosis relative to vector control. Wnt\\/β-catenin signaling plays a key regulatory role in HIV-associated bone loss, with Dkk1, aputative central mediator in this degenerative process. © 2012 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 31: 218-226, 2013.

  12. The cellular decision between apoptosis and autophagy

    Institute of Scientific and Technical Information of China (English)

    Yong-Jun Fan; Wei-Xing Zong

    2013-01-01

    Apoptosis and autophagy are important molecular processes that maintain organismal and cellular homeostasis,respectively.While apoptosis fulfills its role through dismantling damaged or unwanted cells,autophagy maintains cellular homeostasis through recycling selective intracellular organelles and molecules.Yet in some conditions,autophagy can lead to cell death.Apoptosis and autophagy can be stimulated by the same stresses.Emerging evidence indicates an interplay between the core proteins in both pathways,which underlies the molecular mechanism of the crosstalk between apoptosis and autophagy.This review summarizes recent literature on molecules that regulate both the apoptotic and autophagic processes.

  13. Selenium, apoptosis, and colorectal adenomas.

    OpenAIRE

    Connelly-Frost, Alexandra; Poole, Charles; Satia, Jessie A.; Kupper, Lawrence L.; Millikan, Robert C.; Sandler, Robert S.

    2006-01-01

    Dietary modulation of carcinogenesis-related pathwaysDietary item or component studied:seleniumPathways studied:apoptosisStudy type (in vitro, animals, humans): humansStudy design (if human):cross-sectional studyStudy size (if human):803 participantsTissue/biological material/sample size: serum, 2 colon biopsiesMode of exposure (if in vivo) (acute, chronic, root of exposure):dietary & lifestyle questionnairesImpact on pathway (including dose-response):for 50-120 μgr/l selenium Pe~0.5-0.3For ...

  14. Cationic Antimicrobial Polymers and Their Assemblies

    Directory of Open Access Journals (Sweden)

    Ana Maria Carmona-Ribeiro

    2013-05-01

    Full Text Available Cationic compounds are promising candidates for development of antimicrobial agents. Positive charges attached to surfaces, particles, polymers, peptides or bilayers have been used as antimicrobial agents by themselves or in sophisticated formulations. The main positively charged moieties in these natural or synthetic structures are quaternary ammonium groups, resulting in quaternary ammonium compounds (QACs. The advantage of amphiphilic cationic polymers when compared to small amphiphilic molecules is their enhanced microbicidal activity. Besides, many of these polymeric structures also show low toxicity to human cells; a major requirement for biomedical applications. Determination of the specific elements in polymers, which affect their antimicrobial activity, has been previously difficult due to broad molecular weight distributions and random sequences characteristic of radical polymerization. With the advances in polymerization control, selection of well defined polymers and structures are allowing greater insight into their structure-antimicrobial activity relationship. On the other hand, antimicrobial polymers grafted or self-assembled to inert or non inert vehicles can yield hybrid antimicrobial nanostructures or films, which can act as antimicrobials by themselves or deliver bioactive molecules for a variety of applications, such as wound dressing, photodynamic antimicrobial therapy, food packing and preservation and antifouling applications.

  15. Cobalt 60 cation exchange with mexican clays

    International Nuclear Information System (INIS)

    Mexican clays can be used to remove radioactive elements from contaminated aqueous solutions. Cation exchange experiments were performed with 60 Co radioactive solution. In the present work the effect of contact time on the sorption of Co 2+ was studied. The contact time in hydrated montmorillonite was from 5 to 120 minutes and in dehydrated montmorillonite 5 to 1400 minutes. The Co 2+ uptake value was, in hydrated montmorillonite, between 0.3 to 0.85 m eq/g and in dehydrated montmorillonite, between 0.6 to 1.40 m eq/g. The experiments were done in a pH 5.1 to 5.7 and normal conditions. XRD patterns were used to characterize the samples. The crystallinity was determined by X-ray Diffraction and it was maintained before and after the cation exchange. DTA thermo grams showed the temperatures of the lost humidity and crystallization water. Finally, was observed that dehydrated montmorillonite adsorb more cobalt than hydrated montmorillonite. (Author)

  16. Photodissociation of Cerium Oxide Nanocluster Cations.

    Science.gov (United States)

    Akin, S T; Ard, S G; Dye, B E; Schaefer, H F; Duncan, M A

    2016-04-21

    Cerium oxide cluster cations, CexOy(+), are produced via laser vaporization in a pulsed nozzle source and detected with time-of-flight mass spectrometry. The mass spectrum displays a strongly preferred oxide stoichiometry for each cluster with a specific number of metal atoms x, with x ≤ y. Specifically, the most prominent clusters correspond to the formula CeO(CeO2)n(+). The cluster cations are mass selected and photodissociated with a Nd:YAG laser at either 532 or 355 nm. The prominent clusters dissociate to produce smaller species also having a similar CeO(CeO2)n(+) formula, always with apparent leaving groups of (CeO2). The production of CeO(CeO2)n(+) from the dissociation of many cluster sizes establishes the relative stability of these clusters. Furthermore, the consistent loss of neutral CeO2 shows that the smallest neutral clusters adopt the same oxidation state (IV) as the most common form of bulk cerium oxide. Clusters with higher oxygen content than the CeO(CeO2)n(+) masses are present with much lower abundance. These species dissociate by the loss of O2, leaving surviving clusters with the CeO(CeO2)n(+) formula. Density functional theory calculations on these clusters suggest structures composed of stable CeO(CeO2)n(+) cores with excess oxygen bound to the surface as a superoxide unit (O2(-)). PMID:27035210

  17. Cytokine Expression in CD3+ Cells in an Infant with Food Protein-Induced Enterocolitis Syndrome (FPIES: Case Report

    Directory of Open Access Journals (Sweden)

    F. Mori

    2009-01-01

    Full Text Available Food protein-induced enterocolitis syndrome (FPIES is a non-IgE-mediated food allergy characterized by severe vomiting, diarrhea, and often failure to thrive in infants. Symptoms typically resolve after the triggering food-derived protein is removed from the diet and recur within few hours after the re-exposure to the causal protein. The diagnosis is based on clinical symptoms and a positive food challenge. In this study, we report a case of FPIES to rice in an 8-month-old boy. We performed a double-blind placebo-controlled food challenge (DBPCFC to rice and we measured the intracellular T cell expression of interleukin-4 (IL-4; IL-10, and interferon (IFN- pre-and post-challenge during an acute FPIES reaction and when tolerance to rice had been achieved. For the first time we describe an increase in T cell IL-4 and decrease in IFN- expression after a positive challenge with rice (i.e. rice triggered a FPIES attack and an increase in T cell IL-10 expression after rice challenge 6 months later after a negative challenge (i.e., the child had acquired tolerance to rice in an 8 month old with documented FPIES to rice. A Th2 activation associated with high IL-4 levels may contribute to the pathophysiology of the disease. On the other hand, T cell-derived IL-10 may play a role in the acquisition of immunotolerance by regulating the Th1 and Th2 responses.

  18. Clinical utility of protein induced by vitamin K absence in patients with chronic hepatitis B virus infection

    Science.gov (United States)

    TRUONG, BUI XUAN; YANO, YOSHIHIKO; VAN, VU TUONG; SEO, YASUSHI; NAM, NGUYEN HOAI; TRACH, NGUYEN KHANH; UTSUMI, TAKAKO; AZUMA, TAKESHI; HAYASHI, YOSHITAKE

    2013-01-01

    Hepatitis B virus (HBV) is a leading cause of hepatocellular carcinoma (HCC). α-fetoprotein (AFP) is a common tumor marker for the diagnosis of HCC, although not for protein induced by the absence of vitamin K or antagonist-II (PIVKA-II). The present study aimed to evaluate the role of PIVKA-II in the diagnosis of HCC in HBV-infected Vietnamese patients. A total of 166 consecutive HBV-infected Vietnamese patients were enrolled, including 41 HCC, 43 liver cirrhosis (LC), 26 chronic hepatitis (CH) and 56 asymptomatic carriers (ASC). AFP was examined using ELISA, while PIVKA-II was analyzed using Eitest PIVKA-II. The cut-off level of AFP and PIVKA-II was 20 ng/ml and 40 mAU/ml, respectively. Although the markers, AFP (344±356 ng/ml) and PIVKA-II (16,200±25,386 mAU/ml), were the highest in the HCC groups, only PIVKA-II in HCC was significantly higher compared to the other groups (P<0.001). The univariate analysis demonstrated that age over 50, male, genotype C, AFP and PIVKA-II were risk factors of LC and HCC. Results of the receiver operating characteristics (ROC) analysis showed that PIVKA-II was more sensitive to HCC compared to AFP. Moreover, PIVKA-II was strongly correlated with the portal venous thrombosis in HCC, as opposed to AFP. Results of the multivariate analysis demonstrated that PIVKA-II was the strongest independent risk factor of LC and HCC. In conclusion, PIVKA-II is likely to be a better marker for the diagnosis of HCC in chronic HBV-infected Vietnamese patients. PMID:24648907

  19. Clinical utility of protein induced by vitamin K absence in patients with chronic hepatitis B virus infection.

    Science.gov (United States)

    Truong, Bui Xuan; Yano, Yoshihiko; VAN, Vu Tuong; Seo, Yasushi; Nam, Nguyen Hoai; Trach, Nguyen Khanh; Utsumi, Takako; Azuma, Takeshi; Hayashi, Yoshitake

    2013-01-01

    Hepatitis B virus (HBV) is a leading cause of hepatocellular carcinoma (HCC). α-fetoprotein (AFP) is a common tumor marker for the diagnosis of HCC, although not for protein induced by the absence of vitamin K or antagonist-II (PIVKA-II). The present study aimed to evaluate the role of PIVKA-II in the diagnosis of HCC in HBV-infected Vietnamese patients. A total of 166 consecutive HBV-infected Vietnamese patients were enrolled, including 41 HCC, 43 liver cirrhosis (LC), 26 chronic hepatitis (CH) and 56 asymptomatic carriers (ASC). AFP was examined using ELISA, while PIVKA-II was analyzed using Eitest PIVKA-II. The cut-off level of AFP and PIVKA-II was 20 ng/ml and 40 mAU/ml, respectively. Although the markers, AFP (344±356 ng/ml) and PIVKA-II (16,200±25,386 mAU/ml), were the highest in the HCC groups, only PIVKA-II in HCC was significantly higher compared to the other groups (PPIVKA-II were risk factors of LC and HCC. Results of the receiver operating characteristics (ROC) analysis showed that PIVKA-II was more sensitive to HCC compared to AFP. Moreover, PIVKA-II was strongly correlated with the portal venous thrombosis in HCC, as opposed to AFP. Results of the multivariate analysis demonstrated that PIVKA-II was the strongest independent risk factor of LC and HCC. In conclusion, PIVKA-II is likely to be a better marker for the diagnosis of HCC in chronic HBV-infected Vietnamese patients.

  20. Ground state of naphthyl cation: Singlet or triplet?

    Energy Technology Data Exchange (ETDEWEB)

    Dutta, Achintya Kumar; Vaval, Nayana, E-mail: np.vaval@ncl.res.in; Pal, Sourav, E-mail: s.pal@ncl.res.in [Physical Chemistry Division, CSIR-National Chemical Laboratory, Pune 411008 (India); Manohar, Prashant U. [Department of Chemistry, BITS Pilani, Pilani Campus (India)

    2014-03-21

    We present a benchmark theoretical investigation on the electronic structure and singlet-triplet(S-T) gap of 1- and 2-naphthyl cations using the CCSD(T) method. Our calculations reveal that the ground states of both the naphthyl cations are singlet, contrary to the results obtained by DFT/B3LYP calculations reported in previous theoretical studies. However, the triplet states obtained in the two structural isomers of naphthyl cation are completely different. The triplet state in 1-naphthyl cation is (π,σ) type, whereas in 2-naphthyl cation it is (σ,σ{sup ′}) type. The S-T gaps in naphthyl cations and the relative stability ordering of the singlet and the triplet states are highly sensitive to the basis-set quality as well as level of correlation, and demand for inclusion of perturbative triples in the coupled-cluster ansatz.

  1. Influence of interlayer cations on organic intercalation of montmorillonite.

    Science.gov (United States)

    Wu, Limei; Liao, Libing; Lv, Guocheng

    2015-09-15

    The influence of the types of interlayer cations on organic intercalation of montmorillonite (Mt) was studied in this paper. The distribution of Na(+), K(+), Mg(2+), Ca(2+) and Fe(3+) in montmorillonite interlayer, their interaction with structure layers and the effect of interlayer cations on the basal spacing of Mt, the amount of binding water for different interlayer cations and the binding force between them were investigated systematically. 1-Hexadecy1-3-methylimidazolium chloride monohydrate (C16mimCl) was intercalated into montmorillonites with different interlayer cations. The influence of interlayer cations on organic intercalation was investigated. Molecular dynamics (MD) modeling was used to speculate the interlayer microstructures of the organically intercalated Mt with different interlayer cations. These simulations help to predict the microstructure of organo-Mt and guide their relevant engineering applications. PMID:26001131

  2. Bespoke cationic nano-objects via RAFT aqueous dispersion polymerisation

    OpenAIRE

    Williams, M.; Penfold, NJW; Lovett, JR; Warren, NJ; Douglas, CWI; Doroshenko, N; Verstraete, P; Smets, J; Armes, SP

    2016-01-01

    A range of cationic diblock copolymer nanoparticles are synthesised via polymerisation-induced self-assembly (PISA) using a RAFT aqueous dispersion polymerisation formulation. The cationic character of these nanoparticles can be systematically varied by utilising a binary mixture of two macro-CTAs, namely non-ionic poly(glycerol monomethacrylate) (PGMA) and cationic poly[2-(methacryloyloxy)ethyl]trimethylammonium chloride (PQDMA), with poly(2-hydroxypropyl methacrylate) (PHPMA) being selected...

  3. Development of Recombinant Cationic Polymers for Gene Therapy Research

    OpenAIRE

    Canine, Brenda F.; Hatefi, Arash

    2010-01-01

    Cationic polymers created through recombinant DNA technology have the potential to fill a void in the area of gene delivery. The recombinant cationic polymers to be discussed here are amino acid based polymers synthesized in E.coli with the purpose to not only address the major barriers to efficient gene delivery but offer safety, biodegradability, targetability and cost-effectiveness. This review helps the readers to get a better understanding about the evolution of recombinant cationic poly...

  4. Performance of Protein Induced by Vitamin K Absence or Antagonist-II (PIVKA-II) for Hepatocellular Carcinoma Screening in Chinese Population

    OpenAIRE

    Yu, Rentao; Ding, Shitao; Tan, Wenting; Tan, Shun; Tan, Zhaoxia; Xiang, Shiqing; Zhou, Yi; Mao, Qing; Deng, Guohong

    2015-01-01

    Background: Alpha-fetoprotein (AFP) has long been used as an effective biomarker for hepatocellular carcinoma (HCC) screening; however, not all HCC patients can be detected with an elevated AFP level, especially in early HCC patients. Protein Induced by vitamin K absence or antagonist-II (PIVKA-II) is another serum biomarker linked to HCC; however, sensitivity and specificity remain controversial and data in Chinese groups is even rarer. Objectives: To evaluate the performance of PIVKA-II alo...

  5. Postoperative changes in protein-induced vitamin K absence or antagonist II levels after hepatectomy in patients with hepatocellular carcinoma: relationship to prognosis

    OpenAIRE

    Nanashima, A.; Sumida, Y.; Tobinaga, S.; Shibata, K.; Shindo, H; Obatake, M.; Shibasaki, S.; Ide, N.; Nagayasu, Takeshi

    2006-01-01

    Background. α-Fetoprotein (AFP) has been used as a marker for hepatocellular carcinoma (HCC). However, AFP levels are often high in patients with chronic hepatitis or cirrhosis. Protein-induced vitamin K absence or antagonist II (PIVKA-II) is more sensitive for the diagnosis of HCC and prediction of patient survival. Changes in these markers after treatment may reflect treatment curability and patient outcome. Methods. We conducted a retrospective analysis of prognosis of 63 HCC patients with...

  6. Sulphoraphane, a naturally occurring isothiocyanate induces apoptosis in breast cancer cells by targeting heat shock proteins

    Energy Technology Data Exchange (ETDEWEB)

    Sarkar, Ruma; Mukherjee, Sutapa [Department of Environmental Carcinogenesis and Toxicology, Chittaranjan National Cancer Institute, 37, SP Mukherjee Road, Kolkata 700 026 (India); Biswas, Jaydip [Chittaranjan National Cancer Institute, 37, SP Mukherjee Road, Kolkata 700 026 (India); Roy, Madhumita, E-mail: mitacnci@yahoo.co.in [Department of Environmental Carcinogenesis and Toxicology, Chittaranjan National Cancer Institute, 37, SP Mukherjee Road, Kolkata 700 026 (India)

    2012-10-12

    Highlights: Black-Right-Pointing-Pointer HSPs (27, 70 and 90) and HSF1 are overexpressed in MCF-7 and MDA-MB-231 cells. Black-Right-Pointing-Pointer Sulphoraphane, a natural isothiocyanate inhibited HSPs and HSF1 expressions. Black-Right-Pointing-Pointer Inhibition of HSPs and HSF1 lead to regulation of apoptotic proteins. Black-Right-Pointing-Pointer Alteration of apoptotic proteins activate of caspases particularly caspase 3 and 9 leading to induction of apoptosis. Black-Right-Pointing-Pointer Alteration of apoptotic proteins induce caspases leading to induction of apoptosis. -- Abstract: Heat shock proteins (HSPs) are involved in protein folding, aggregation, transport and/or stabilization by acting as a molecular chaperone, leading to inhibition of apoptosis by both caspase dependent and/or independent pathways. HSPs are overexpressed in a wide range of human cancers and are implicated in tumor cell proliferation, differentiation, invasion and metastasis. HSPs particularly 27, 70, 90 and the transcription factor heat shock factor1 (HSF1) play key roles in the etiology of breast cancer and can be considered as potential therapeutic target. The present study was designed to investigate the role of sulphoraphane, a natural isothiocyanate on HSPs (27, 70, 90) and HSF1 in two different breast cancer cell lines MCF-7 and MDA-MB-231 cells expressing wild type and mutated p53 respectively, vis-a-vis in normal breast epithelial cell line MCF-12F. It was furthermore investigated whether modulation of HSPs and HSF1 could induce apoptosis in these cells by altering the expressions of p53, p21 and some apoptotic proteins like Bcl-2, Bax, Bid, Bad, Apaf-1 and AIF. Sulphoraphane was found to down-regulate the expressions of HSP70, 90 and HSF1, though the effect on HSP27 was not pronounced. Consequences of HSP inhibition was upregulation of p21 irrespective of p53 status. Bax, Bad, Apaf-1, AIF were upregulated followed by down-regulation of Bcl-2 and this effect was prominent

  7. Crosstalk between apoptosis and inflammation in atherosclerosis

    NARCIS (Netherlands)

    Westra, Marijke Marianne

    2010-01-01

    In this thesis the role of several apoptosis regulating proteins in the development of atherosclerosis and atherosclerotic plaque stability is investigated. Apoptosis of different cell types in atherosclerotic plaques, such as macrophages and smooth muscle cells may inhibit or promote plaque develop

  8. Apoptosis in odontogenesis - a brief review

    OpenAIRE

    Nair, Bindu J

    2010-01-01

    Tooth formation is an excellent example of epithelial mesenchymal interaction As the developingtooth passes through the various morphologic stages it is observed that apoptosis occurs selectively incertain locations. Here a review is done to throw light into the role of apoptosis and the factorsgoverning the same during odontogenesis .

  9. Apoptosis in odontogenesis - a brief review

    Directory of Open Access Journals (Sweden)

    Bindu J. Nair

    2010-01-01

    Full Text Available Tooth formation is an excellent example of epithelial mesenchymal interaction As the developingtooth passes through the various morphologic stages it is observed that apoptosis occurs selectively incertain locations. Here a review is done to throw light into the role of apoptosis and the factorsgoverning the same during odontogenesis .

  10. HN protein of Newcastle disease virus sensitizes HeLa cells to TNF-α-induced apoptosis by downregulating NF-κB expression.

    Science.gov (United States)

    Rajmani, R S; Gupta, Shishir Kumar; Singh, Prafull Kumar; Gandham, Ravi Kumar; Sahoo, A P; Chaturvedi, Uttara; Tiwari, Ashok K

    2016-09-01

    Hemagglutinin neuraminidase (HN) is a membrane protein of Newcastle disease virus (NDV) with the ability to induce apoptosis in many transformed cell lines. TNF-α is a multi-factorial protein that regulates cell survival, differentiation and apoptosis. In a previous study, we reported that HN protein induces apoptosis by downregulating NF-κB expression. Further, we speculated that downregulation of NF-κB expression might sensitize HeLa cells to TNF-α-mediated apoptosis. Therefore, the present study was undertaken to investigate if HN protein could sensitize HeLa cells to TNF-α and to examine the apoptotic potential of the HN protein and TNF-α in combination. The results revealed that the pro-apoptotic effects were more pronounced with the combination of HN and TNF-α than with HN or TNF-α alone, which indicates that the HN protein indeed sensitized the HeLa cells to TNF-α-induced cell death. The results of the study provide a mechanistic insight into the apoptotic action of HN protein along with TNF-α, which could be valuable in treating tumor types that are naturally resistant to TNF-α. PMID:27294845

  11. APOPTOSIS AFTER SPINAL CORD INJURY IN RATS

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Objective To confirm the role played by apoptosis in spinal cord injury. Methods 36 rats models of spinal cord injury were made by Allen method. Histological examinations using HE staining and in situ end-labeling were used to observe apoptosis in spinal cord tissues from 1h to 21d after injury. Results HE staining sections showed hemorrhage and necrosis, neuronal degeneration and gliai cell proliferation. In situ end-labeling sections showed the appearance of apoptosis in both gray and white matter as well as in both central and surrounding region. The number of apoptotic cells increased from 12h after injury, increased to the peak at 4d and declined to normal at 21d. Conclu sion The results suggest that apoptosis, especially glial apoptosis, plays a role in the pathogenesis of spinal cord in jury.

  12. Hepatitis C virus infection and apoptosis

    Institute of Scientific and Technical Information of China (English)

    Richard Fischer; Thomas Baumert; Hubert E Blum

    2007-01-01

    Apoptosis is central for the control and elimination of viral infections. In chronic hepatitis C virus (HCV) infection,enhanced hepatocyte apoptosis and upregulation of the death inducing ligands CD95/Fas, TRAIL and TNFα occur.Nevertheless, HCV infection persists in the majority of patients. The impact of apoptosis in chronic HCV infection is not well understood. It may be harmful by triggering liver fibrosis, or essential in interferon (IFN)induced HCV elimination. For virtually all HCV proteins,pro- and anti-apoptotic effects have been described,especially for the core and NS5A protein. To date, it is not known which HCV protein affects apoptosis in vivo and whether the infectious virions act pro- or antiapoptotic. With the availability of an infectious tissue culture system, we now can address pathophysiologically relevant issues. This review focuses on the effect of HCV infection and different HCV proteins on apoptosis and of the corresponding signaling cascades.

  13. Study of apoptosis in human liver cancers

    Institute of Scientific and Technical Information of China (English)

    Chang-Min Shan; Juan Li

    2002-01-01

    AIM: To investigate the action of apoptosis in occurrence ofliver cacinornas in vivo and the biological effect of Solanumlyratum Thumb on BEL-7404 cell line inducing apoptosis invitro.METHODS: The apoptosis in the liver carcinoma wasdetected with terminal deoxynucl neotidyl transferasemediated dUTP nick end labelling (TUNEL); the cancer cellscultured in DMED medium were treated with extract ofSolanum lyratum Thumb and observed under microscope,and their DNA was assayed by gel electrophoresis.RESULTS: In vivo apoptotic cells in the cancer adjacenttissues inceased; in vitro treatment of liver cancers withextract of Solanum lyratum Thumb could induce the cells tomanifest a typical apoptotic morphology. Their DNA wasfractured and a characteristic ladder pattem could be foundusing electrophoresis.CONCLUSION: In vivo the apoptosis of carcinomas waslower; maybe the cells divided quickly and then the cancersoccurred. In the cancer adjacent tissues, the apoptosispricked up, and in vitro Solarium lyratum Thumb couldinduce the apoptosis of BEL-7404 cells.

  14. Apoptosis in normal oral tissues and odontogenesis

    Directory of Open Access Journals (Sweden)

    Ruchita Bali

    2013-01-01

    Full Text Available Programmed cell death or apoptosis is considered a vital component of various processes including normal cell turnover, proper development and functioning of the immune system, hormone-dependent atrophy, embryonic development, and chemical-induced cell death. Inappropriate apoptosis (either too little or too much is a factor in many human conditions including neurodegenerative diseases, ischemic damage, autoimmune disorders, and many types of cancers. The process of apoptosis is generally characterized by distinct morphological characteristics and energy-dependent biochemical mechanisms. An understanding of its role in the pathophysiology of oral tissues is pertinent to the development of novel therapeutic approaches. The developing tooth passes through the various morphologic stages and apoptosis is observed selectively in certain locations. This review focuses on the current knowledge of apoptosis emphasizing its role in normal oral tissues and odontogenesis.

  15. Hydration Structure of the Quaternary Ammonium Cations

    KAUST Repository

    Babiaczyk, Wojtek Iwo

    2010-11-25

    Two indicators of the hydropathicity of small solutes are introduced and tested by molecular dynamics simulations. These indicators are defined as probabilities of the orientation of water molecules\\' dipoles and hydrogen bond vectors, conditional on a generalized distance from the solute suitable for arbitrarily shaped molecules. Using conditional probabilities, it is possible to distinguish features of the distributions in close proximity of the solute. These regions contain the most significant information on the hydration structure but cannot be adequately represented by using, as is usually done, joint distance-angle probability densities. Our calculations show that using our indicators a relative hydropathicity scale for the interesting test set of the quaternary ammonium cations can be roughly determined. © 2010 American Chemical Society.

  16. Univalent-cation-elicited acidification by yeasts.

    Science.gov (United States)

    Kotyk, A; Georghiou, G

    1994-08-01

    Addition of univalent cations to sugar-metabolizing Saccharomyces cerevisiae, Schizosaccharomyces pombe and Lodderomyces elongisporus brought about a powerful acidification of the external medium with rates up to nearly 20 nmol H+ per min per mg dry wt. in S. cerevisiae, over 15 nmol in S. pombe, and 4.7 nmol in L. elongisporus. These rates were as much as 20 times, 5.5 times and 10.3 times, respectively. higher than in the absence of K+. Use of galactose-induced cells, of H(+)-ATPase-deficient mutants and observations over the entire growth curve indicated that the K+ effect on H+ extrusion is not connected with the H(+)-ATPase function as such but rather depends on metabolic reactions producing ATP. The effect has apparently nothing to do with the electrical potential across the plasma membrane. PMID:7804140

  17. Retention of Cationic Starch onto Cellulose Fibres

    Science.gov (United States)

    Missaoui, Mohamed; Mauret, Evelyne; Belgacem, Mohamed Naceur

    2008-08-01

    Three methods of cationic starch titration were used to quantify its retention on cellulose fibres, namely: (i) the complexation of CS with iodine and measurement of the absorbency of the ensuing blue solution by UV-vis spectroscopy; (ii) hydrolysis of the starch macromolecules followed by the conversion of the resulting sugars to furan-based molecules and quantifying the ensuing mixture by measuring their absorbance at a Ι of 490 nm, using the same technique as previous one and; finally (iii) hydrolysis of starch macromolecules by trifluoro-acetic acid and quantification of the sugars in the resulting hydrolysates by high performance liquid chromatography. The three methods were found to give similar results within the range of CS addition from 0 to 50 mg per g of cellulose fibres.

  18. Capturing dynamic cation hopping in cubic pyrochlores

    Science.gov (United States)

    Brooks Hinojosa, Beverly; Asthagiri, Aravind; Nino, Juan C.

    2011-08-01

    In direct contrast to recent reports, density functional theory predicts that the most stable structure of Bi2Ti2O7 pyrochlore is a cubic Fd3¯m space group by accounting for atomic displacements. The displaced Bi occupies the 96g(x,x,z) Wyckoff position with six equivalent sites, which create multiple local minima. Using nudged elastic band method, the transition states of Bi cation hopping between equivalent minima were investigated and an energy barrier between 0.11 and 0.21 eV was determined. Energy barriers associated with the motion of Bi between equivalent sites within the 96g Wyckoff position suggest the presence of dielectric relaxation in Bi2Ti2O7.

  19. Interaction of actinide cations with synthetic polyelectrolytes

    International Nuclear Information System (INIS)

    The binding of Am+3, Th+4 and UO2+2 to polymaleic acid, polyethylenemaleic acid and polymethylvinylethermaleic acid has been measured by a solvent extraction technique at 250C and either 0.02 or 0.10 M ionic strength. The solutions were buffered over a pH range such that the percent of carboxylate groups ionized ranged from 25 to 74%. The binding was described by two constants, β1 and β2, which were evaluated after correction for complexation of the actinide cations by acetate and hydrolysis. For comparable degrees of ionization, all three polyelectrolytes showed similar binding strengths. In general, these results indicated that the binding of actinides to these synthetic polyelectrolytes is basically similar to that of natural polyelectrolytes such as humic and fulvic acids. (orig.)

  20. Antiviral effect of cationic compounds on bacteriophages

    Directory of Open Access Journals (Sweden)

    Mai Huong eChatain-Ly

    2013-03-01

    Full Text Available The antiviral activity of several cationic compounds - cetytrimethylammonium (CTAB, chitosan, nisin and lysozyme - was investigated on the bacteriophage c2 (DNA head and non-contractile tail infecting Lactococcus strains and the bacteriophage MS2 (F-specific RNA infecting E.coli. Firstly, these activities were evaluated in a phosphate buffer pH 7- 10 mM. The CTAB had a virucidal effect on the Lactococcus bacteriophages, but not on the MS2. After 1 min of contact with 0.125 mM CTAB, the c2 population was reduced from 6 log(pfu/mL to 1,5 log(pfu/mL and completely deactivated at 1 mM. On the contrary, chitosan inhibited the MS2 more than it did the bacteriophages c2. No antiviral effect was observed for the nisin or the lysozyme on bacteriophages after 1 min of treatment. A 1 and 2.5 log reduction was respectively observed for nisin and lysozyme when the treatment time increased (5 or 10 min. These results showed that the antiviral effect depended both on the virus and structure of the antimicrobial compounds. The antiviral activity of these compounds was also evaluated in different physico-chemical conditions and in complex matrices. The antiviral activity of CTAB was impaired in acid pH and with an increase of the ionic strength. These results might be explained by the electrostatic interactions between cationic compounds and negatively charged particles such as bacteriophages or other compounds in a matrix. Milk proved to be protective suggesting the components of food could interfere with antimicrobial compounds.

  1. Role of extracellular cations in cell motility, polarity, and chemotaxis

    Directory of Open Access Journals (Sweden)

    Soll D

    2011-04-01

    Full Text Available David R Soll1, Deborah Wessels1, Daniel F Lusche1, Spencer Kuhl1, Amanda Scherer1, Shawna Grimm1,21Monoclonal Antibody Research Institute, Developmental Studies, Hybridoma Bank, Department of Biology, University of Iowa, Iowa City; 2Mercy Medical Center, Surgical Residency Program, Des Moines, Iowa, USAAbstract: The concentration of cations in the aqueous environment of free living organisms and cells within the human body influence motility, shape, and chemotaxis. The role of extracellular cations is usually perceived to be the source for intracellular cations in the process of homeostasis. The role of surface molecules that interact with extracellular cations is believed to be that of channels, transporters, and exchangers. However, the role of Ca2+ as a signal and chemoattractant and the discovery of the Ca2+ receptor have demonstrated that extracellular cations can function as signals at the cell surface, and the plasma membrane molecules they interact with can function as bona fide receptors that activate coupled signal transduction pathways, associated molecules in the plasma membrane, or the cytoskeleton. With this perspective in mind, we have reviewed the cationic composition of aqueous environments of free living cells and cells that move in multicellular organisms, most notably humans, the range of molecules interacting with cations at the cell surface, the concept of a cell surface cation receptor, and the roles extracellular cations and plasma membrane proteins that interact with them play in the regulation of motility, shape, and chemotaxis. Hopefully, the perspective of this review will increase awareness of the roles extracellular cations play and the possibility that many of the plasma membrane proteins that interact with them could also play roles as receptors.Keywords: extracellular cations, chemotaxis, transporters, calcium, receptors

  2. Efficient delivery of Notch1 siRNA to SKOV3 cells by cationic cholesterol derivative-based liposome

    Science.gov (United States)

    Zhao, Yun-Chun; Zhang, Li; Feng, Shi-Sen; Hong, Lu; Zheng, Hai-Li; Chen, Li-Li; Zheng, Xiao-Ling; Ye, Yi-Qing; Zhao, Meng-Dan; Wang, Wen-Xi; Zheng, Cai-Hong

    2016-01-01

    A novel cationic cholesterol derivative-based small interfering RNA (siRNA) interference strategy was suggested to inhibit Notch1 activation in SKOV3 cells for the gene therapy of ovarian cancer. The cationic cholesterol derivative, N-(cholesterylhemisuccinoyl-amino-3-propyl)-N, N-dimethylamine (DMAPA-chems) liposome, was incubated with siRNA at different nitrogen-to-phosphate ratios to form stabilized, near-spherical siRNA/DMAPA-chems nanoparticles with sizes of 100–200 nm and zeta potentials of 40–50 mV. The siRNA/DMAPA-chems nanoparticles protected siRNA from nuclease degradation in 25% fetal bovine serum. The nanoparticles exhibited high cell uptake and Notch1 gene knockdown efficiency in SKOV3 cells at an nitrogen-to-phosphate ratio of 100 and an siRNA concentration of 50 nM. They also inhibited the growth and promoted the apoptosis of SKOV3 cells. These results may provide the potential for using cationic cholesterol derivatives as efficient nonviral siRNA carriers for the suppression of Notch1 activation in ovarian cancer cells.

  3. Induction of Apoptosis by L-NMMA, via FKHRL1/ROCK Pathway in Human Gastric Cancer Cells

    Institute of Scientific and Technical Information of China (English)

    YONG-ZHONG WANG; ZHEN-QING FENG

    2006-01-01

    To investigate the apoptosis-inducing effect of endogenous nitric oxide (NO) suppression in gastric cancer cells and its mechanisms. Methods Apoptosis of gastric cancer cells was detected by flow cytometry. Expression of phosphorylated FKHRL1 (thr-32, ser-253) and FKHRL1 in gastric cancer cells was analyzed using Western blotting.Immunofluorescence assay was performed to localize the intracellular phosphorylated FKHRL1 (thr-32, ser-253) and FKHRL1.Transfection of FKHRL1-HA wild type and mutant FKHRL1-HA T32A constructs was performed by lipofectamine plus reagent. NO generation was determined by Griess reaction. Results Gastric cancer cells were significantly apoptotic after treatment with NG-monomethyl-L-arginine (L-NMMA, a nitric oxide synthase inhibitor), compared with the control (P<0.01).The apoptosis of gastric cancer cells induced by L-NMMA was dose-dependent and time-independent. However, the Z-DEVD-fmk, a caspase-3, 6, 7, 8, 10 inhibitor, did not prevent the apoptosis. The immunofluorescence assays showed that FKHRL1 protein was strongly expressed in the nucleu and p-FKHRL1 thr-32 protein was strongly expressed in the cytoplasm of SGC-7901 cells when endogenous nitric oxide generation was blocked by L-NMMA, but no change in FKHRL1 ser-253phosphorylation. Nevertheless, ROCK protein was strongly expressed in p-FKHRL1 thr-32-positive SGC-7901 cells. The wortmannin, an inhibitor of phosphoinositol-3-OH kinase (PI3K), did not block the phosphorylated FKHRL1 thr-32 protein induced by L-NMMA. However, Y-27632, a specific inhibitor of the protein kinase ROCK, significantly blocked apoptosis induced by phosphorylated FKHRL1 thr-32 (P<0.01), which was mediated by L-NMMA. A significant decrease in NO generation (P<0.01) and a significant increase in apoptosis (P<0.01) were observed when FKHRL1-HA wild-type cells were transfected, which caused increased FKHRL1 thr-32 phosphorylation. Conclusions L-NMMA triggers gastric carcinoma cell apoptosis, possibly by

  4. The Effect of Hydration on the Cation-π Interaction Between Benzene and Various Cations

    Indian Academy of Sciences (India)

    VIKASH DHINDHWAL; N SATHYAMURTHY

    2016-10-01

    The effect of hydration on cation-π interaction in Mq+ BmWn (B = benzene; W = water; Mq+ =Na⁺, K⁺, Mg²⁺, Ca²⁺, Al³⁺, 0 ≤ n,m ≤ 4, 1≤ m + n ≤ 4) complexes has been investigated using ab initio quantum chemical methods. Interaction energy values computed at the MP2 level of theory using the 6-31G(d,p) basis set reveal a qualitative trend in the relative affinity of different cations for benzene and water in these complexes. The π–cloud thickness values for benzene have also been estimated for these systems.

  5. Crystal structure of channelrhodopsin, a light-gated cation channel - all cations lead through the monomer.

    Science.gov (United States)

    Kato, Hideaki E; Nureki, Osamu

    2013-01-01

    Channelrhodopsin (ChR) is a light-gated cation channel derived from green algae. Since the inward flow of cations triggers the neuron firing, neurons expressing ChRs can be optically controlled even within freely moving mammals. Although ChR has been broadly applied to neuro-science research, little is known about its molecular mechanisms. We determined the crystal structure of chimeric ChR at 2.3 Å resolution and revealed its molecular architecture. The integration of structural, electrophysio-logical, and computational analyses provided insight into the molecular basis for the channel function of ChR, and paved the way for the principled design of ChR variants with novel properties. PMID:27493541

  6. In vivo toxicity of cationic micelles and liposomes

    DEFF Research Database (Denmark)

    Knudsen, Kristina Bram; Northeved, Helle; Ek, Pramod Kumar;

    2015-01-01

    This study investigated toxicity of nanocarriers comprised of cationic polymer and lipid components often used in gene and drug delivery, formulated as cationic micelles and liposomes. Rats were injected intravenously with 10, 25 or 100 mg/kg and sacrificed after 24 or 48 h, or 24 h after the las...

  7. Stable polyfluorinated cycloalkenyl cations and their NMR spectra

    International Nuclear Information System (INIS)

    New stable 1-methoxyperfluoro-2-ethylcyclobutenyl, 1-methoxyperfluoro-2-methylcyclo-pentenyl, and 1-methoxyperfluoro-2-ethylcyclohexenyl cations were obtained by the action of antimony pentafluoride on the corresponding olefins. The distribution of the charges in the investigated polyfluorinated cycloalkenyl cations was investigated by 13C NMR method

  8. Photodynamic Inactivation of Bacteria and Biofilms Using Cationic Bacteriochlorins

    Science.gov (United States)

    Meerovich, G. A.; Tiganova, I. G.; Makarova, E. A.; Meerovich, I. G.; Romanova Ju., M.; Tolordova, E. R.; Alekseeva, N. V.; Stepanova, T. V.; Yu, Koloskova; Luk'anets, E. A.; Krivospitskaya, N. V.; Sipailo, I. P.; Baikova, T. V.; Loschenov, V. B.; Gonchukov, S. A.

    2016-02-01

    This work is devoted to the study of two new synthetic bacteriochlorins with four and eight cationic substitutes as the photosensitizers in the photodynamic process. The spectral and antibacterial properties of these photosensitizers in saline solution were investigated. It is shown, that the aggregation ability decreases and the antibacterial efficiency grows as the cationic substitute number increases.

  9. Effects of metallic cations in the beryl flotation

    International Nuclear Information System (INIS)

    The beryl zeta potential in microelectrophoretic cell is studied in the presence of neutral electrolyte, cations of calcium, magnesium and iron. The petroleum sulfonate is used how collector in Hallimond tube. Hydroxy complex of metallic cations seems activate the ore and precipitates of colloidal metallic hidroxies seems lower him when added to the mixture. (M.A.C.)

  10. Honey and Apoptosis in Human Gastric Mucosa

    Directory of Open Access Journals (Sweden)

    Alireza Ostadrahimi

    2012-07-01

    Full Text Available Background: Gastric cancer is the fourth most common malignancy in the world. Honey is acomplex mixture of special biological active constituents. Honey possesses antioxidant and antitumorproperties. Nutritional studies have indicated that consumption of honey modulates therisk of developing gastric cancer. On the other hand, apoptosis has been reported to play a decisiverole in precancerous changes. Our chief study was conducted to assess the relationship betweenconsumption of honey and apoptosis in human gastric mucosa.Method: This cross-sectional study was conducted on 98 subjects over 18 years old, referred totwo hospitals in Tabriz, Iran. Subjects were undergone an upper gastrointestinal endoscopy, 62subjects were finally enrolled. Honey consumption was assessed by a Food Frequency Questionnaire(FFQ and apoptosis was detected by TUNEL technique. We tested polynomial curve tofind the best fit between honey consumption and apoptosis.Results: A positive relation between honey consumption and apoptosis was found (P=0.024.Our results indicated that the final and the best fit curve was: apoptosis = 1.714+1.648(honeyamount - 0.533(honey amount2 +1.833×10-5(honey amount7.Conclusion: Honey consumption had positive effects on gastric cancer by inducing apoptosis ingastric mucosa.

  11. Do Cation-π Interactions Exist in Bacteriorhodopsin

    Institute of Scientific and Technical Information of China (English)

    HU Kun-Sheng; WANG Guang-Yu; HE Jin-An

    2001-01-01

    Metal ions are essential to the structure and physiological functions of bacteriorhodopsin. Experimental evidence suggests the existence of specific cation binding to the negatively charged groups of Asp85 and Asp212 via an electrostatic interaction. However, only using electrostatic force is not enough to explain the role of the metal cations because the carboxylate of Asp85 is well known to be protonated in the M intermediate. Considering the presence of some aromatic amino acid residues in the vicinity of the retinal pocket, the existence of cation-π interactions between the metal cation and aromatic amino acid residues is suggested. Obviously, introduction of this kind of interaction is conducive to understanding the effects of the metal cations and aromatic amino acid residues inside the protein on the structural stability and proton pumping of bacteriorhodopsin.

  12. Cytochrome c and insect cell apoptosis

    Institute of Scientific and Technical Information of China (English)

    Kai-Yu Liu; Hong Yang; Jian-Xin Peng; Hua-Zhu Hong

    2012-01-01

    The role ofcytochrome c in insect cell apoptosis has drawn considerable attention and has been subject to considerable controversy.In Drosophila,the majority of studies have demonstrated that cytochrome c may not be involved in apoptosis,although there are conflicting reports.Cytochrome c is not released from mitochondria into the cytosol and activation of the initiator caspase Dronc or effector caspase Drice is not associated with cytochrome c during apoptosis in Drosophila SL2 cells or BG2 cells.Cytochrome c failed to induce caspase activation and promote caspase activation in Drosophila cell lysates,but remarkably caused caspase activation in extracts from human cells.Knockdown of cytochrome c does not protect cells from apoptosis and over-expression of cytochrome c also does not promote apoptosis.Structural analysis has revealed that cytochrome c is not required for Dapaf-1 complex assembly.In Lepidoptera,the involvement of cytochrome c in apoptosis has been demonstrated by the accumulating evidence.Cytochrome c release from mitochondria into cytosol has been observed in different cell lines such as Spodoptera frugiperda Sf9,Spodoptera litura S1-1 and Lymantria dispar LdFB.Silencing of cytochrome c expression significantly affected apoptosis and activation of caspase and the addition of cytochrome c to cell-free extracts results in caspase activation,suggesting the activation of caspase is dependent on cytochrome c.Although Apaf- 1 has not been identified in Lepidoptera,the inhibitor of apoptosome formation can inhibit apoptosis and caspase activation.Cytochrome c may be exclusively required for Lepidoptera apoptosis.

  13. Repurposing Cationic Amphiphilic Antihistamines for Cancer Treatment

    DEFF Research Database (Denmark)

    Ellegaard, Anne-Marie; Dehlendorff, Christian; Vind, Anna C.;

    2016-01-01

    Non-small cell lung cancer (NSCLC) is one of the deadliest cancers worldwide. In search for new NSCLC treatment options, we screened a cationic amphiphilic drug (CAD) library for cytotoxicity against NSCLC cells and identified several CAD antihistamines as inducers of lysosomal cell death. We the...... of loratadine, astemizole and ebastine sensitized NSCLC cells to chemotherapy and reverted multidrug resistance in NSCLC, breast and prostate cancer cells. Thus, CAD antihistamines may improve the efficacy of cancer chemotherapy...... then performed a cohort study on the effect of CAD antihistamine use on mortality of patients diagnosed with non-localized cancer in Denmark between 1995 and 2011. The use of the most commonly prescribed CAD antihistamine, loratadine, was associated with significantly reduced all-cause mortality among patients...... with non-localized NSCLC or any non-localized cancer when compared with use of non-CAD antihistamines and adjusted for potential confounders. Of the less frequently described CAD antihistamines, astemizole showed a similar significant association with reduced mortality as loratadine among patients with any...

  14. Repurposing Cationic Amphiphilic Antihistamines for Cancer Treatment

    Directory of Open Access Journals (Sweden)

    Anne-Marie Ellegaard

    2016-07-01

    Full Text Available Non-small cell lung cancer (NSCLC is one of the deadliest cancers worldwide. In search for new NSCLC treatment options, we screened a cationic amphiphilic drug (CAD library for cytotoxicity against NSCLC cells and identified several CAD antihistamines as inducers of lysosomal cell death. We then performed a cohort study on the effect of CAD antihistamine use on mortality of patients diagnosed with non-localized cancer in Denmark between 1995 and 2011. The use of the most commonly prescribed CAD antihistamine, loratadine, was associated with significantly reduced all-cause mortality among patients with non-localized NSCLC or any non-localized cancer when compared with use of non-CAD antihistamines and adjusted for potential confounders. Of the less frequently described CAD antihistamines, astemizole showed a similar significant association with reduced mortality as loratadine among patients with any non-localized cancer, and ebastine use showed a similar tendency. The association between CAD antihistamine use and reduced mortality was stronger among patients with records of concurrent chemotherapy than among those without such records. In line with this, sub-micromolar concentrations of loratadine, astemizole and ebastine sensitized NSCLC cells to chemotherapy and reverted multidrug resistance in NSCLC, breast and prostate cancer cells. Thus, CAD antihistamines may improve the efficacy of cancer chemotherapy.

  15. Repurposing Cationic Amphiphilic Antihistamines for Cancer Treatment.

    Science.gov (United States)

    Ellegaard, Anne-Marie; Dehlendorff, Christian; Vind, Anna C; Anand, Atul; Cederkvist, Luise; Petersen, Nikolaj H T; Nylandsted, Jesper; Stenvang, Jan; Mellemgaard, Anders; Østerlind, Kell; Friis, Søren; Jäättelä, Marja

    2016-07-01

    Non-small cell lung cancer (NSCLC) is one of the deadliest cancers worldwide. In search for new NSCLC treatment options, we screened a cationic amphiphilic drug (CAD) library for cytotoxicity against NSCLC cells and identified several CAD antihistamines as inducers of lysosomal cell death. We then performed a cohort study on the effect of CAD antihistamine use on mortality of patients diagnosed with non-localized cancer in Denmark between 1995 and 2011. The use of the most commonly prescribed CAD antihistamine, loratadine, was associated with significantly reduced all-cause mortality among patients with non-localized NSCLC or any non-localized cancer when compared with use of non-CAD antihistamines and adjusted for potential confounders. Of the less frequently described CAD antihistamines, astemizole showed a similar significant association with reduced mortality as loratadine among patients with any non-localized cancer, and ebastine use showed a similar tendency. The association between CAD antihistamine use and reduced mortality was stronger among patients with records of concurrent chemotherapy than among those without such records. In line with this, sub-micromolar concentrations of loratadine, astemizole and ebastine sensitized NSCLC cells to chemotherapy and reverted multidrug resistance in NSCLC, breast and prostate cancer cells. Thus, CAD antihistamines may improve the efficacy of cancer chemotherapy. PMID:27333030

  16. Therapeutic potential of cationic steroid antibacterials.

    Science.gov (United States)

    Salmi, Chanaz; Brunel, Jean M

    2007-08-01

    Antibiotics were one of the great health successes of the 20th century. Antibiotics, both naturally derived and synthetic, have resulted in huge decreases in both morbidity and mortality from bacterial infections. As a consequence, the 'antibiotic age' has changed public expectations about the results of infectious disease. However, this has led to high levels of inappropriate prescribing, where antibiotics may be administered to fulfil patient expectations rather than for clinical benefit. Along with unwise uses in agriculture and elsewhere, this has contributed to recent rises in numbers of antibiotic-resistant bacteria. As a result, many commentators have described this as the end of the antibiotic age and the term 'superbug' has entered the common vocabulary for multi-drug-resistant bacteria such as vancomycin-resistant Enterococcus, multi-drug-resistant Staphylococcus aureus and multi-drug-resistant Pseudomonas aeruginosa. In this context, an attractive approach for the development of antibacterial agents is the use of a new class of cationic steroidal compounds mimicking polymyxin activities. The permeabilization properties of these agents of the outer membranes of Gram-negative bacteria are reported in this review, as well as a discussion of literature results. PMID:17685865

  17. Crystal structure of pseudouridine synthase RluA: indirect sequence readout through protein-induced RNA structure.

    Science.gov (United States)

    Hoang, Charmaine; Chen, Junjun; Vizthum, Caroline A; Kandel, Jason M; Hamilton, Christopher S; Mueller, Eugene G; Ferré-D'Amaré, Adrian R

    2006-11-17

    RluA is a dual-specificity enzyme responsible for pseudouridylating 23S rRNA and several tRNAs. The 2.05 A resolution structure of RluA bound to a substrate RNA comprising the anticodon stem loop of tRNA(Phe) reveals that enzyme binding induces a dramatic reorganization of the RNA. Instead of adopting its canonical U turn conformation, the anticodon loop folds into a new structure with a reverse-Hoogsteen base pair and three flipped-out nucleotides. Sequence conservation, the cocrystal structure, and the results of structure-guided mutagenesis suggest that RluA recognizes its substrates indirectly by probing RNA loops for their ability to adopt the reorganized fold. The planar, cationic side chain of an arginine intercalates between the reverse-Hoogsteen base pair and the bottom pair of the anticodon stem, flipping the nucleotide to be modified into the active site of RluA. Sequence and structural comparisons suggest that pseudouridine synthases of the RluA, RsuA, and TruA families employ an equivalent arginine for base flipping.

  18. Molecular imaging of apoptosis in cancer

    Energy Technology Data Exchange (ETDEWEB)

    Hakumaeki, Juhana M. [Cellular and Molecular Imaging Group, Department of Biomedical NMR, A.I. Virtanen Institute for Molecular Sciences, University of Kuopio, P.O. Box 1627, FI-70211 Kuopio (Finland) and Department of Clinical Radiology, Kuopio University Hospital, P.O. Box 1777, FI-70211 Kuopio (Finland)]. E-mail: juhana.hakumaki@uku.fi; Liimatainen, Timo [Cellular and Molecular Imaging Group, Department of Biomedical NMR, A.I. Virtanen Institute for Molecular Sciences, University of Kuopio, P.O. Box 1627, FI-70211 Kuopio (Finland)

    2005-11-01

    Apoptosis plays an important role in cancer. Mechanisms hindering its action are implicated in a number of malignancies. Also, the induction of apoptosis plays a pivotal role in non-surgical cancer treatment regimes such as irradiation, chemotherapy, or hormones. Recent advanced in imaging science have made it now possible for us to detect and visualize previously inaccessible and even unrecognized biological phenomena in cells and tissue undergoing apoptosis in vivo. Not only are these imaging techniques painting an intriguing picture of the spatiotemporal characteristics and metabolic and biophysical of apoptosis in situ, but they are expected to have an ever increasing impact in preclinical testing and design of new anticancer agents as well. Rapid and accurate visualization of apoptotic response in the clinical settings can also be of significant diagnostic and prognostic worth. With the advent of molecular medicine and patient-tailored treatment options and therapeutic agents, such monitoring techniques are becoming paramount.

  19. [The comeback of mitochondria in Drosophila apoptosis].

    Science.gov (United States)

    Clavier, Amandine; Rincheval-Arnold, Aurore; Mignotte, Bernard; Guénal, Isabelle

    2016-05-01

    The role of the mitochondrion in mammalian cell apoptosis has been established since the mid-1990s. However, the importance of this organelle in non-mammalian apoptosis has long been regarded as minor, notably because of the absence of a crucial role for cytochrome c in caspase activation. Recent results indicate that the control of caspase activation and apoptosis in Drosophila cell death occurs at the mitochondrial level. Numerous proteins that appear key for Drosophila apoptosis regulation constitutively or transiently bind to mitochondria. They participate in the cell death process at different levels such as degradation of an IAP caspase inhibitor, production of mitochondrial reactive oxygen species or stimulation of the mitochondrial fission machinery. The aim of this review is to take stock of these events that might have their counterpart in humans. PMID:27225920

  20. Competitive Effects of 2+ and 3+ Cations on DNA Compaction

    CERN Document Server

    Tongu, C; Yoshikawa, Y; Zinchenko, A A; Chen, N; Yoshikawa, K

    2016-01-01

    By using single-DNA observation with fluorescence microscopy, we observed the effects of divalent and trivalent cations on the higher-order structure of giant DNA (T4 DNA with 166 kbp). It was found that divalent cations, such as Mg(2+) and Ca(2+), inhibit DNA compaction induced by a trivalent cation, spermidine (SPD(3+)). On the other hand, in the absence of SPD(3+), divalent cations cause the shrinkage of DNA. These experimental observations are inconsistent with the well-established Debye-Huckel scheme regarding the shielding effect of counter ions, which is given as the additivity of contributions of cations with different valences. We interpreted the competition between 2+ and 3+ cations in terms of the change in the translational entropy of the counter ions before and after the folding transition of DNA. For the compaction with SPD(3+), we considered the increase in translational entropy due to the ion-exchange of the intrinsic monovalent cations condensing on a highly-charged polyelectrolyte, double-st...

  1. Cations bind only weakly to amides in aqueous solutions.

    Science.gov (United States)

    Okur, Halil I; Kherb, Jaibir; Cremer, Paul S

    2013-04-01

    We investigated salt interactions with butyramide as a simple mimic of cation interactions with protein backbones. The experiments were performed in aqueous metal chloride solutions using two spectroscopic techniques. In the first, which provided information about contact pair formation, the response of the amide I band to the nature and concentration of salt was monitored in bulk aqueous solutions via attenuated total reflection Fourier transform infrared spectroscopy. It was found that molar concentrations of well-hydrated metal cations (Ca(2+), Mg(2+), Li(+)) led to the rise of a peak assigned to metal cation-bound amides (1645 cm(-1)) and a decrease in the peak associated with purely water-bound amides (1620 cm(-1)). In a complementary set of experiments, the effect of cation identity and concentration was investigated at the air/butyramide/water interface via vibrational sum frequency spectroscopy. In these studies, metal ion-amide binding led to the ordering of the adjacent water layer. Such experiments were sensitive to the interfacial partitioning of cations in either a contact pair with the amide or as a solvent separated pair. In both experiments, the ordering of the interactions of the cations was: Ca(2+) > Mg(2+) > Li(+) > Na(+) ≈ K(+). This is a direct cationic Hofmeister series. Even for Ca(2+), however, the apparent equilibrium dissociation constant of the cation with the amide carbonyl oxygen was no tighter than ∼8.5 M. For Na(+) and K(+), no evidence was found for any binding. As such, the interactions of metal cations with amides are far weaker than the analogous binding of weakly hydrated anions.

  2. APOPTOSIS, OXIDATIVE STRESS AND NEUROLOGICAL DISEASE

    Directory of Open Access Journals (Sweden)

    P. Formichi

    2012-01-01

    Full Text Available Apoptosis is a selective cell deletion process which requires the triggering of a specific cell death programme. Two main pathways determining cell death have been identified: the extrinsic or receptor-mediated pathway, activated in response to extracellular pro-apoptotic signals, and the intrinsic pathway, activated by extracellular receptor-independent stimuli or by intracellular insults, such as DNA damage and oxidative stress. All these stress signals are integrated by mitochondria which participate by releasing the main effectors of this process: a family of aspartic-specific proteases known as caspase. Today there is much evidence to suggest that deregulation of apoptosis is a key feature of many neurodegenerative disease. Our group sought cell models for the study of apoptotic pathways and for the evaluation of the role of apoptosis in specific neurodegenerative diseases. We focused on oxidative stress-induced apoptosis and activation of the intrinsic mitochondrial pathway. In our in-vitro model, lymphocytes from patients and control subjects were cultured both in basal conditions and with 2-deoxy-D-ribose (dRib, a reducing sugar which induces apoptosis through oxidative stress. In the last ten years, we evaluated the role of apoptosis in the pathogenesis of several neurodegenerative diseases: Ataxiatelangiectasia,Rett syndrome, Mitochondrial disease, Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL. Here we report some of our ongoing and recently published articles.

  3. Epithelial Cell Apoptosis and Lung Remodeling

    Institute of Scientific and Technical Information of China (English)

    Kazuyoshi Kuwano

    2007-01-01

    Lung epithelium is the primary site of lung damage in various lung diseases. Epithelial cell apoptosis has been considered to be initial event in various lung diseases. Apoptosis signaling is classically composed of two principle pathways. One is a direct pathway from death receptor ligation to caspase cascade activation and cell death. The other pathway triggered by stresses such as drugs, radiation, infectious agents and reactive oxygen species is mediated by mitochondria. Endoplasmic reticulum has also been shown to be the organelle to mediate apoptosis.Epithelial cell death is followed by remodeling processes, which consist of epithelial and fibroblast activation,cytokine production, activation of coagulation pathway, neoangiogenesis, re-epithelialization and fibrosis.Epithelial and mesenchymal interaction plays important roles in these processes. Further understanding of apoptosis signaling and its regulation by novel strategies may lead to effective treatments against various lung diseases. We review the recent advances in the understanding of apoptosis signaling and discuss the involvement of apoptosis in lung remodeling.

  4. Effect of sevoflurane on human neutrophil apoptosis.

    LENUS (Irish Health Repository)

    Tyther, R

    2012-02-03

    BACKGROUND AND OBJECTIVE: Both chronic occupational exposure to volatile anaesthetic agents and acute in vitro exposure of neutrophils to isoflurane have been shown to inhibit the rate of apoptosis of human neutrophils. It is possible that inhibition of neutrophil apoptosis arises through delaying mitochondrial membrane potential collapse. We assessed mitochondrial depolarization and apoptosis in unexposed neutrophils and neutrophils exposed to sevoflurane in vivo. METHODS: A total of 20 mL venous blood was withdrawn pre- and postinduction of anaesthesia, the neutrophils isolated and maintained in culture. At 1, 12 and 24 h in culture, the percentage of neutrophil apoptosis was assessed by dual staining with annexin V-FITC and propidium iodide. Mitochondrial depolarization was measured using the dual emission styryl dye JC-1. RESULTS: Apoptosis was significantly inhibited in neutrophils exposed to sevoflurane in vivo at 24 (exposed: 38 (12)% versus control: 28 (11)%, P = 0.001), but not at 1 or 12 h, in culture. Mitochondrial depolarization was not delayed in neutrophils exposed to sevoflurane. CONCLUSIONS: The most important findings are that sevoflurane inhibits neutrophil apoptosis in vivo and that inhibition is not mediated primarily by an effect on mitochondrial depolarization.

  5. [Protein kinase C activation induces platelet apoptosis].

    Science.gov (United States)

    Zhao, Li-Li; Chen, Meng-Xing; Zhang, Ming-Yi; Dai, Ke-Sheng

    2013-10-01

    Platelet apoptosis elucidated by either physical or chemical compound or platelet storage occurs wildly, which might play important roles in controlling the numbers and functions of circulated platelets, or in the development of some platelet-related diseases. However, up to now, a little is known about the regulatory mechanisms of platelet apoptosis. Protein kinase C (PKC) is highly expressed in platelets and plays central roles in regulating platelet functions. Although there is evidence indicating that PKC is involved in the regulation of apoptosis of nucleated cells, it is still unclear whether PKC plays a role in platelet apoptosis. The aim of this study was to investigate the role of PKC in platelet apoptosis. The effects of PKC on mitochondrial membrane potential (ΔΨm), phosphatidylserine (PS) exposure, and caspase-3 activation of platelets were analyzed by flow cytometry and Western blot. The results showed that the ΔΨm depolarization in platelets was induced by PKC activator in time-dependent manner, and the caspase-3 activation in platelets was induced by PKC in concentration-dependent manner. However, the platelets incubated with PKC inhibitor did not results in ΔΨm depolarization and PS exposure. It is concluded that the PKC activation induces platelet apoptosis through influencing the mitochondrial functions and activating caspase 3. The finds suggest a novel mechanism for PKC in regulating platelet numbers and functions, which has important pathophysiological implications for thrombosis and hemostasis.

  6. Host-pathogen interactions during apoptosis

    Indian Academy of Sciences (India)

    Seyed E Hasnain; Rasheeda Begum; K V A Ramaiah; Sudhir Sahdev; E M Shajil; Tarvinder K Taneja; Manjari Mohan; M Athar; Nand K Sah; M Krishnaveni

    2003-04-01

    Host pathogen interaction results in a variety of responses, which include phagocytosis of the pathogen, release of cytokines, secretion of toxins, as well as production of reactive oxygen species (ROS). Recent studies have shown that many pathogens exert control on the processes that regulate apoptosis in the host. The induction of apoptosis upon infection results from a complex interaction of parasite proteins with cellular host proteins. Abrogation of host cell apoptosis is often beneficial for the pathogen and results in a successful host invasion. However, in some cases, it has been shown that induction of apoptosis in the infected cells significantly imparts protection to the host from the pathogen. There is a strong correlation between apoptosis and the host protein translation machinery: the pathogen makes all possible efforts to modify this process so as to inhibit cell suicide and ensure that it can survive and, in some cases, establish latent infection. This review discusses the significance of various pathways/steps during virus-mediated modulation of host cell apoptosis.

  7. Diagnostic Performance of Alpha-Fetoprotein, Protein Induced by Vitamin K Absence, Osteopontin, Dickkopf-1 and Its Combinations for Hepatocellular Carcinoma

    OpenAIRE

    Eun Sun Jang; Sook-Hyang Jeong; Jin-Wook Kim; Yun Suk Choi; Philippe Leissner; Christian Brechot

    2016-01-01

    Background & Aims Alpha-fetoprotein (AFP) is the most widely used serum biomarker for hepatocellular carcinoma (HCC), despite its limitations. As complementary biomarkers, protein induced by vitamin K absence (PIVKA-II), osteopontin (OPN), and Dickkopf-1 (DKK-1) have been proposed. This study aimed to perform a head-to-head comparison of the diagnostic performance of AFP, PIVKA-II, OPN and DKK-1 as single or in combination to seek the best biomarker or panel, and to investigate the clinical f...

  8. Prolonged Survival in a Case of Chemotherapy-Sensitive Gastric Cancer That Produced Alpha-Fetoprotein and Protein Induced by Vitamin K Antagonist-II

    OpenAIRE

    Ogasawara, Naotaka; Takahashi, Emiko; Matsumoto, Tomoko; Amaike, Manami; Nohara, Mako; Nagao, Kazuhiro; Ebi, Masahide; Funaki, Yasushi; Sasaki, Makoto; Kasugai, Kunio

    2015-01-01

    The number of reported cases of alpha-fetoprotein (AFP)-producing gastric cancer has gradually increased, with a reported prevalence of 1.3–1.5% of all gastric cancer cases. However, reports of gastric cancer accompanied by elevated serum levels of both AFP and protein induced by vitamin K antagonist-II (PIVKA-II) are rare. The prognosis of AFP- and PIVKA-II-producing gastric cancer has been reported to be very poor because the tumor cells were considered to have a high malignant potential an...

  9. The Significance of Gastric Juice Analysis for a Positive Challenge by a Standard Oral Challenge Test in Typical Cow's Milk Protein-Induced Enterocolitis

    OpenAIRE

    Hwang, Jin-Bok; Song, Jeong-Yoon; Kang, Yu Na; Kim, Sang Pyo; Suh, Seong-Il; Kam, Sin; Choi, Won Joung

    2008-01-01

    This study was performed to investigate the significance of gastric juice analysis (GJA) as a diagnostic criterion of a positive challenge in a standard oral cow's milk challenge (OCC) to confirm typical cow's milk protein-induced enterocolitis (CMPIE). Data from 16 CMPIE patients (aged 14 to 44 days) were analyzed. A standard OCC was openly executed using 0.15 g/kg of protein. Three symptoms (vomiting, lethargy, and bloody or pus-like stool), and four laboratory findings (GJA [3 hr], changes...

  10. Competitive Solvation of the Imidazolium Cation by Water and Methanol

    CERN Document Server

    Chaban, Vitaly

    2014-01-01

    Imidazolium-based ionic liquids are widely used in conjunction with molecular liquids for various applications. Solvation, miscibility and similar properties are of fundamental importance for successful implementation of theoretical schemes. This work reports competitive solvation of the 1,3-dimethylimidazolium cation by water and methanol. Employing molecular dynamics simulations powered by semiempirical Hamiltonian (electronic structure level of description), the local structure nearly imidazolium cation is described in terms of radial distribution functions. Although water and methanol are chemically similar, water appears systematically more successful in solvating the 1,3-dimethylimidazolium cation. This result fosters construction of future applications of the ternary ion-molecular systems.

  11. Pyridine radical cation and its fluorine substituted derivatives

    Science.gov (United States)

    Bondybey, V.E.; English, J.H.; Shiley, R.H.

    1982-01-01

    The spectra and relaxation of the pyridine cation and of several of its fluorinated derivatives are studied in low temperature Ne matrices. The ions are generated by direct photoionization of the parent compounds. Of the compounds studied, laser induced → and → fluorescence is observed only for the 2, 6‐difluoropyridine cation. The analysis of the spectrum indicates that the ion is planar both in the and states. The large variety in the spectroscopic and relaxation behavior of fluoropyridine radical cations is explained in terms of their electronic structure and of the differential shifts of the individual electronic states caused by the fluorine substitution.

  12. Isomerization of propargyl cation to cyclopropenyl cation: Mechanistic elucidations and effects of lone pair donors

    Indian Academy of Sciences (India)

    Zodinpuia Pachuau; Kiew S Kharnaior; R H Duncan Lyngdoh

    2013-03-01

    This ab initio study examines two pathways (one concerted and the other two-step) for isomerization of the linear propargyl cation to the aromatic cyclopropenyl cation, also probing the phenomenon of solvation of this reaction by simple lone pair donors (NH3, H2O, H2S and HF) which bind to the substrate at two sites. Fully optimized geometries at the B3LYP/6-31G(d) level were used, along with single point QCISD(T)/6-311+G(d,p) and accurate G3 level calculations upon the DFT optimized geometries. For the unsolvated reaction, the two-step second pathway is energetically favoured over the one-step first pathway. Lone pair donor affinity for the various C3H$^{+}_{3}$ species follows the uniform order NH3 > H2S>H2O>HF. The activation barriers for the solvated isomerizations decrease in the order HF>H2O>H2S>NH3 for both pathways. The number of lone pairs on the donor heteroatom as well as the heteroatom electronegativity are factors related to both these trends. Compared to the unsolvated cases, the solvated reactions have transition states which are usually ‘later’ in position along the reaction coordinate, validating the Hammond postulate.

  13. Blocking lhh Signaling Pathway Inhibits the Proliferation and Pro-motes the Apoptosis of PSCs

    Institute of Scientific and Technical Information of China (English)

    Kai XU; Fengjing GUO; Shuwei ZHANG; Cheng LIU; Feixiong WANG; Zhiguo ZHOU; Anmin CHEN

    2009-01-01

    The roles of Indian hedgehog (Ihh) signaling pathway in the proliferation and apoptosis of precartilaginous stem cells (PSCs) were investigated.PSCs,labeled with fibroblast growth factor receptor 3 (FGFR-3),were isolated from neonatal rats by immanomagnetic separation.After identifi-cation with FGFR-3 and Col Ⅱ,the cells were incubated with different concentrations of cyclopamine (cyclo),the specific inhibitor of lhh signaling pathway.The morphologic changes of the cells were observed under the inverted phase contrast microscope.The mRNA expression levels of Ibh,para-thyroid hormonerelated peptide (PTHrP),protein Patched (Ptch),Bcl-2 and p21 were detected by RT-PCR.The protein expression levels of Ihh and Ptch were measured by Western blot.MTT assay was used to examine the effects of cyclo on proliferation of PSCs.Apoptosis rate of PSCs was exam-ined by Annexin V/PI assay of flow cytometric analyses.After PSCs were incubated with cyclo,ob-vious morphologic changes were observed as compared with the control group.The mRNA expres-sion levels of PTHrP,Ptch and Bcl-2 were decreased to varying degrees in a cyclo dose-dependent manner.However,the expression levels of lhh and p21 mRNA were increased.The protein expres-sion of Ptch and Ihh had the same change as the mRNA expression.Meanwhile,cyclo could obvi-ously inhibit the proliferation and promote the apoptosis of PSCs.The results indicated that Ihh sig-naling pathway plays an important role in regulating the proliferation and apoptosis of PSCs,which is probably mediated by Bcl-2 and p21.

  14. Morphologic criteria and detection of apoptosis.

    Science.gov (United States)

    Saraste, A

    1999-05-01

    Apoptosis is an organized, energy dependent process, which leads to cell death. Its definition is based on distinct morphological features [10] and demonstration of internucleosomal DNA degradation [27], executed by selectively activated DNAses [4, 22]. The morphologic hallmarks of apoptosis include chromatic margination, nuclear condensation and fragmentation, and condensation of the cell with preservation of organelles. The process is followed by fragmentation of the cell into membrane-bound apoptotic bodies, which undergo phagocytosis by nearby cells without associated inflammation [10, 11]. Apoptosis characteristically occurs in insolated single cells. The duration of apoptosis is estimated to be from 12 to 24 hours, but in cell culture visible morphologic changes are accomplished in less than two hours [10, 16]. Non-apoptotic cell death, a prototype of which is cell death due to ischemia (oncosis), is characterized by depletion of intracellular ATP stores, swelling of the cell with disruption of organelles and rupture of the plasma membrane [15]. Groups of necrotic cells and inflammation are found in tissues [10, 15]. The significance of apoptosis has mostly been studied using the TUNEL assay that detects DNA strand breaks in tissue sections and allows quantification of apoptotic cells by light microscopy [6]. Common experience seems to be that the TUNEL assay is prone to false positive or negative findings. This has been explained by the dependence of the staining kinetics on the reagent concentration [17], fixation of the tissue [2] and the extent of proteolysis [17]. Active RNA synthesis [12] and DNA damage in necrotic cells [17, 19] may cause non-specific staining. To obtain reliable and reproducible results, TUNEL assay should be carefully standardized by using tissue sections treated with DNAse (positive control of apoptosis). Quantification of apoptosis should include enough microscopic fields and identification of the cell type undergoing apoptosis

  15. Cationic drug-based self-assembled polyelectrolyte complex micelles: Physicochemical, pharmacokinetic, and anticancer activity analysis.

    Science.gov (United States)

    Ramasamy, Thiruganesh; Poudel, Bijay Kumar; Ruttala, Himabindu; Choi, Ju Yeon; Hieu, Truong Duy; Umadevi, Kandasamy; Youn, Yu Seok; Choi, Han-Gon; Yong, Chul Soon; Kim, Jong Oh

    2016-10-01

    Nanofabrication of polymeric micelles through self-assembly of an ionic block copolymer and oppositely charged small molecules has recently emerged as a promising method of formulating delivery systems. The present study therefore aimed to investigate the interaction of cationic drugs doxorubicin (DOX) and mitoxantrone (MTX) with the anionic block polymer poly(ethylene oxide)-block-poly(acrylic acid) (PEO-b-PAA) and to study the influence of these interactions on the pharmacokinetic stability and antitumor potential of the formulated micelles in clinically relevant animal models. To this end, individual DOX and MTX-loaded polyelectrolyte complex micelles (PCM) were prepared, and their physicochemical properties and pH-responsive release profiles were studied. MTX-PCM and DOX-PCM exhibited a different release profile under all pH conditions tested. MTX-PCM exhibited a monophasic release profile with no initial burst, while DOX-PCM exhibited a biphasic release. DOX-PCM showed a higher cellular uptake than that shown by MTX-PCM in A-549 cancer cells. Furthermore, DOX-PCM induced higher apoptosis of cancer cells than that induced by MTX-PCM. Importantly, both MTX-PCM and DOX-PCM showed prolonged blood circulation. MTX-PCM improved the AUCall of MTX 4-fold compared to a 3-fold increase by DOX-PCM for DOX. While a definite difference in blood circulation was observed between MTX-PCM and DOX-PCM in the pharmacokinetic study, both MTX-PCM and DOX-PCM suppressed tumor growth to the same level as the respective free drugs, indicating the potential of PEGylated polymeric micelles as effective delivery systems. Taken together, our results show that the nature of interactions of cationic drugs with the polyionic copolymer can have a tremendous influence on the biological performance of a delivery system. PMID:27318960

  16. DFT study on the cycloreversion of thietane radical cations.

    Science.gov (United States)

    Domingo, Luis R; Pérez-Ruiz, Raúl; Argüello, Juan E; Miranda, Miguel A

    2011-06-01

    The molecular mechanism of the cycloreversion (CR) of thietane radical cations has been analyzed in detail at the UB3LYP/6-31G* level of theory. Results have shown that the process takes place via a stepwise mechanism leading to alkenes and thiobenzophenone; alternatively, formal [4+2] cycloadducts are obtained. Thus, the CR of radical cations 1a,b(•+) is initiated by C2-C3 bond breaking, giving common intermediates INa,b. At this stage, two reaction pathways are feasible involving ion molecule complexes IMCa,b (i) or radical cations 4a,b(•+) (ii). Calculations support that 1a(•+) follows reaction pathway ii (leading to the formal [4+2] cycloadducts 5a). By contrast, 1b(•+) follows pathway i, leading to trans-stilbene radical cation (2b(•+)) and thiobenzophenone.

  17. Degradation Mechanism of Cationic Red X-GRL by Ozonation

    Institute of Scientific and Technical Information of China (English)

    Wei Rong ZHAO; Xin Hua XU; Hui Xiang SHI; Da Hui WANG

    2003-01-01

    The degradation mechanism of Cationic Red X-GRL was investigated when the intermediates, the nitrate ion and the pH were analyzed in the ozonation. The degradation of the Cationic Red X-GRL includes the de-auxochrome stage, the decolour stage, and the decomposition of fragment stage. During the degradation process, among the six nitrogen atoms of Cationic Red X-GRL, one is transferred into a nitrate ion, one becomes the form of an amine compound, and the rest four are transformed into two molecules of nitrogen. In the course of the ozonation of Cationic Red X-GRL, the direct attack of ozone is the main decolour effect.

  18. Condensation of nonstochiometric DNA/polycation complexes by divalent cations.

    Science.gov (United States)

    Budker, Vladimir; Trubetskoy, Vladimir; Wolff, Jon A

    2006-12-15

    This study found that divalent cations induced the further condensation of partially condensed DNA within nonstochiometric polycation complexes. The addition of a few mmol of a divalent cation such as calcium reduced by half the inflection point at which DNA became fully condensed by poly-L-lysine (PLL) and a variety of other polycations. The effect on DNA condensation was initially observed using a new method, which is based on the concentration-dependent self-quenching of fluorescent moieties (e.g., rhodamine) covalently linked to the DNA backbone at relatively high densities. Additional analyses, which employed ultracentrifugation, dynamic light scattering, agarose gel electrophoresis, and atomic force microscopy, confirmed the effect of divalent cations. These results provide an additional accounting of the process by which divalent cations induce greater chromatin compaction that is based on the representation of chromatin fibers as a nonstoichiometric polyelectrolyte complex. They also offer a new approach to assemble nonviral vectors for gene therapy.

  19. Apoptosis and apoptosis-associated parameters in relation to tamoxifen exposure in postmenopausal endometrium

    NARCIS (Netherlands)

    Mourits, MJE; Hollema, H; De Vries, EGE; Ten Hoor, KA; Willemse, PHB; Van der Zee, AGJ

    2002-01-01

    Tamoxifen increases endometrial cell proliferation and the incidence of endometrial cancer in postmenopausal women. The purpose of this study was to evaluate apoptosis and apoptosis-related factors in endometrium. in relation to tamoxifen exposure. We analyzed benign postmenopausal endometrium. from

  20. Cationic Polyamidoamine Dendrimers as Modulators of EGFR Signaling In Vitro and In Vivo.

    Directory of Open Access Journals (Sweden)

    Saghir Akhtar

    Full Text Available Cationic polyamidoamine (PAMAM dendrimers are branch-like spherical polymers being investigated for a variety of applications in nanomedicine including nucleic acid drug delivery. Emerging evidence suggests they exhibit intrinsic biological and toxicological effects but little is known of their interactions with signal transduction pathways. We previously showed that the activated (fragmented generation (G 6 PAMAM dendrimer, Superfect (SF, stimulated epidermal growth factor receptor (EGFR tyrosine kinase signaling-an important signaling cascade that regulates cell growth, survival and apoptosis- in cultured human embryonic kidney (HEK 293 cells. Here, we firstly studied the in vitro effects of Polyfect (PF, a non-activated (intact G6 PAMAM dendrimer, on EGFR tyrosine kinase signaling via extracellular-regulated kinase 1/2 (ERK1/2 and p38 mitogen-activated protein kinase (MAPK in cultured HEK 293 cells and then compared the in vivo effects of a single administration (10mg/kg i.p of PF or SF on EGFR signaling in the kidneys of normal and diabetic male Wistar rats. Polyfect exhibited a dose- and time-dependent inhibition of EGFR, ERK1/2 and p38 MAPK phosphorylation in HEK-293 cells similar to AG1478, a selective EGFR inhibitor. Administration of dendrimers to non-diabetic or diabetic animals for 24h showed that PF inhibited whereas SF stimulated EGFR phosphorylation in the kidneys of both sets of animals. PF-mediated inhibition of EGFR phosphorylation as well as SF or PF-mediated apoptosis in HEK 293 cells could be significantly reversed by co-treatment with antioxidants such as tempol implying that both these effects involved an oxidative stress-dependent mechanism. These results show for the first time that SF and PF PAMAM dendrimers can differentially modulate the important EGFR signal transduction pathway in vivo and may represent a novel class of EGFR modulators. These findings could have important clinical implications for the use of PAMAM

  1. Cationic Polyamidoamine Dendrimers as Modulators of EGFR Signaling In Vitro and In Vivo.

    Science.gov (United States)

    Akhtar, Saghir; Al-Zaid, Bashayer; El-Hashim, Ahmed Z; Chandrasekhar, Bindu; Attur, Sreeja; Yousif, Mariam H M; Benter, Ibrahim F

    2015-01-01

    Cationic polyamidoamine (PAMAM) dendrimers are branch-like spherical polymers being investigated for a variety of applications in nanomedicine including nucleic acid drug delivery. Emerging evidence suggests they exhibit intrinsic biological and toxicological effects but little is known of their interactions with signal transduction pathways. We previously showed that the activated (fragmented) generation (G) 6 PAMAM dendrimer, Superfect (SF), stimulated epidermal growth factor receptor (EGFR) tyrosine kinase signaling-an important signaling cascade that regulates cell growth, survival and apoptosis- in cultured human embryonic kidney (HEK 293) cells. Here, we firstly studied the in vitro effects of Polyfect (PF), a non-activated (intact) G6 PAMAM dendrimer, on EGFR tyrosine kinase signaling via extracellular-regulated kinase 1/2 (ERK1/2) and p38 mitogen-activated protein kinase (MAPK) in cultured HEK 293 cells and then compared the in vivo effects of a single administration (10mg/kg i.p) of PF or SF on EGFR signaling in the kidneys of normal and diabetic male Wistar rats. Polyfect exhibited a dose- and time-dependent inhibition of EGFR, ERK1/2 and p38 MAPK phosphorylation in HEK-293 cells similar to AG1478, a selective EGFR inhibitor. Administration of dendrimers to non-diabetic or diabetic animals for 24h showed that PF inhibited whereas SF stimulated EGFR phosphorylation in the kidneys of both sets of animals. PF-mediated inhibition of EGFR phosphorylation as well as SF or PF-mediated apoptosis in HEK 293 cells could be significantly reversed by co-treatment with antioxidants such as tempol implying that both these effects involved an oxidative stress-dependent mechanism. These results show for the first time that SF and PF PAMAM dendrimers can differentially modulate the important EGFR signal transduction pathway in vivo and may represent a novel class of EGFR modulators. These findings could have important clinical implications for the use of PAMAM dendrimers

  2. Metformin induces apoptosis of pancreatic cancer cells

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    AIM: To assess the role and mechanism of mefformin in inducing apoptosis of pancreatic cancer cells. METHODS: The human pancreatic cancer cell lines ASPC-1, BxPc-3, PANC-1 and SW1990 were exposed to mefformin. The inhibition of cell proliferation and colony formation via apoptosis induction and S phase arrest in pancreatic cancer cell lines of mefformin was tested.RESULTS: In each pancreatic cancer cell line tested, metformin inhibited cell proliferation in a dose dependent manner in MTS (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium assays). Flow cytometric analysis showed that metformin reduced the number of cells in G1 and increased the percentage of cells in S phase as well as the apoptotic fraction. Enzymelinked immunosorbent assay (EUSA) showed that metformin induced apaptosis in all pancreatic cancer cell lines. In Western blot studies, metformin induced oly-ADP-ribose polymerase(PARP) cleavage (an indicator of aspase activation) in all pancreatic cancer cell lines. The general caspase inhibitor (VAD-fmk) completely abolished metformin-induced PARP cleavage and apoptosis in ASPC-1 BxPc-3 and PANC-1, the caspase-8 specific inhibitor (IETD-fmk) and the caspase-9 specific inhibitor (LEHD-fmk) only partially abrogated metformin-induced apoptosis and PARP cleavage in BxPc-3 and PANC-1 cells. We also observed that metformin treatment ramatically reduced epidermal growth factor receptor (EGFR) and phosphorylated mitogen activated protein kinase (P-MAPK) in both a time- and dose-dependent manner in all cell lines tested.CONCLUSION: Metformin significantly inhibits cell proliferation and apoptosis in all pancreatic cell lines. And the metformin-induced apoptosis is associated with PARP leavage, activation of caspase-3, -8, and -9 in a time- and dose-dependent manner. Hence, both caspase-8 and -9-initiated apoptotic signaling pathways contribute to metforrnin-induced apoptosis in pancreatic cell lines.

  3. Sulfometuron incorporation in cationic micelles adsorbed on montmorillonite

    OpenAIRE

    Mishael, Y. G.; Undabeytia López, Tomás; Rytwo, Giora; Papahadjopoulos Sternberg, B.; Rubin, Baruch; Nir, Shlomo

    2002-01-01

    The aim of this study was to understand the interactions between alkylammonium cations present as monomers and micelles and a clay mineral, montmorillonite, to develop slow release formulations of anionic herbicides, such as sulfometuron (SFM) whose leaching in soils is an environmental and economic problem. In the proposed formulation the herbicide is incorporated in positively charged micelles of quaternary amine cations, which in turn adsorb on the negatively charged clay. The adsorption o...

  4. Microscopic Theory of Cation Exchange in CdSe Nanocrystals

    OpenAIRE

    Ott, Florian D.; Spiegel, Leo L.; Norris, David J.; Erwin, Steven C.

    2014-01-01

    Although poorly understood, cation-exchange reactions are increasingly used to dope or transform colloidal semiconductor nanocrystals (quantum dots). We used density-functional theory and kinetic Monte Carlo simulations to develop a microscopic theory that explains structural, optical, and electronic changes observed experimentally in Ag-cation-exchanged CdSe nanocrystals. We find that Coulomb interactions, both between ionized impurities and with the polarized nanocrystal surface, play a key...

  5. Migration of Cations and Anions in Amorphous Polymer Electrolytes

    Institute of Scientific and Technical Information of China (English)

    N.A.Stolwijk; S.H.Obeidi; M.Wiencierz

    2007-01-01

    1 Results Polymer electrolytes are used as ion conductors in batteries and fuel cells.Simple systems consist of a polymer matrix complexing an inorganic salt and are fully amorphous at the temperatures of interest.Both cations and anions are mobile and contribute to charge transport.Most studies on polymer electrolytes use the electrical conductivity to characterize the ion mobility.However,conductivity measurements cannot discriminate between cations and anions.This paper reports some recent results fr...

  6. Mercury release from deforested soils triggered by base cation enrichment.

    Science.gov (United States)

    Farella, N; Lucotte, M; Davidson, R; Daigle, S

    2006-09-01

    The Brazilian Amazon has experienced considerable colonization in the last few decades. Family agriculture based on slash-and-burn enables millions of people to live in that region. However, the poor nutrient content of most Amazonian soils requires cation-rich ashes from the burning of the vegetation biomass for cultivation to be successful, which leads to forest ecosystem degradation, soil erosion and mercury contamination. While recent studies have suggested that mercury present in soils was transferred towards rivers upon deforestation, little is known about the dynamics between agricultural land-use and mercury leaching. In this context, the present study proposes an explanation that illustrates how agricultural land-use triggers mercury loss from soils. This explanation lies in the competition between base cations and mercury in soils which are characterized by a low adsorption capacity. Since these soils are naturally very poor in base cations, the burning of the forest biomass suddenly brings high quantities of base cations to soils, destabilizing the previous equilibrium amongst cations. Base cation enrichment triggers mobility in soil cations, rapidly dislocating mercury atoms. This conclusion comes from principal component analyses illustrating that agricultural land-use was associated with base cation enrichment and mercury depletion. The overall conclusions highlight a pernicious cycle: while soil nutrient enrichment actually occurs through biomass burning, although on a temporary basis, there is a loss in Hg content, which is leached to rivers, entering the aquatic chain, and posing a potential health threat to local populations. Data presented here reflects three decades of deforestation activities, but little is known about the long-term impact of such a disequilibrium. These findings may have repercussions on our understanding of the complex dynamics of deforestation and agriculture worldwide. PMID:16781764

  7. Modulatory role of bivalent cations on reward system.

    Science.gov (United States)

    Nechifor, M; Chelărescu, D

    2008-01-01

    Bivalent cations (Ca, Mg, Zn, Mn etc.) modulate activity of reward system (RS). At physiologic levels they may influence all components of RS. There are influenced behavioral reactions at physiological stimuli and all essential elements of drug dependence (compulsive intake of substance, craving, reinforcement, withdrawal syndrom, relapse and reinstatement of intake) The fact that some cations (e.g. calcium) enhance some of the aspects of drug dependence and others (e.g. magnesium, zinc) decrease intensity of this process show that ratio between intra- and extracellular in the brain of these cations is important for the function of RS. Among actions of different cations at the level of RS there are important differences. Their mecahanism of action are common in part and specific in other. It is important the fact that modulatory action appear at physiologic cation concentrations (that could be reached at therapeutic doses). Modulatory action is related to ratio between concetrations of different bivalent cations and is exerted both in normal or pathologic conditions.

  8. Synthesis and characterisation of cationically modified phospholipid polymers.

    Science.gov (United States)

    Lewis, Andrew L; Berwick, James; Davies, Martyn C; Roberts, Clive J; Wang, Jin-Hai; Small, Sharon; Dunn, Anthony; O'Byrne, Vincent; Redman, Richard P; Jones, Stephen A

    2004-07-01

    Phospholipid-like copolymers based on 2-(methacryloyloxyethyl) phosphorylcholine were synthesised using monomer-starved free radical polymerisation methods and incorporating cationic charge in the form of the choline methacrylate monomer in amounts varying from 0 to 30 wt%, together with a 5 wt% silyl cross-linking agent in order to render them water-insoluble once thermally cured. Characterisation using a variety of techniques including nuclear magnetic resonance spectroscopy, high-pressure liquid chromatography and gel permeation chromatography showed the cationic monomer did not interfere with the polymerisation and that the desired amount of charge had been incorporated. Gravimetric and differential scanning calorimetry methods were used to evaluate the water contents of polymer membranes cured at 70 degrees C, which was seen to increase with increasing cation content, producing materials with water contents ranging from 50% to 98%. Surface plasmon resonance indicated that the coatings swelled rapidly in water, the rate and extent of swelling increasing with increasing cation level. Dynamic contact angle showed that coatings of all the polymers possessed a hydrophobic surface when dry in air, characteristic of the alkyl chains expressed at the surface (>100 degrees advancing angle). Rearrangement of the hydrophilic groups to the surface occurred once wet, to produce highly wettable surfaces with a decrease in advancing angle with increasing cation content. Atomic force microscopy showed all polymer films to be smooth with no features in topographical or phase imaging. Mechanical properties of the dry films were also unaffected by the increase in cation content.

  9. Complexation Between Cationic Diblock Copolymers and Plasmid DNA

    Science.gov (United States)

    Jung, Seyoung; Reineke, Theresa; Lodge, Timothy

    Deoxyribonucleic acids (DNA), as polyanions, can spontaneously bind with polycations to form polyelectrolyte complexes. When the polycation is a diblock copolymer with one cationic block and one uncharged hydrophilic block, the polyelectrolyte complexes formed with plasmid DNA (pDNA) are often colloidally stable, and show great promise in the field of polymeric gene therapy. While the resulting properties (size, stability, and toxicity to biological systems) of the complexes have been studied for numerous cationic diblocks, the fundamentals of the pDNA-diblock binding process have not been extensively investigated. Herein, we report how the cationic block content of a diblock influences the pDNA-diblock interactions. pDNA with 7164 base pairs and poly(2-deoxy-2-methacrylamido glucopyranose)-block-poly(N-(2-aminoethyl) methacrylamide) (PMAG-b-PAEMA) are used as the model pDNA and cationic diblock, respectively. To vary the cationic block content, two PMAG-b-PAEMA copolymers with similar PMAG block lengths but distinct PAEMA block lengths and a PAEMA homopolymer are utilized. We show that the enthalpy change from pDNA-diblock interactions is dependent on the cationic diblock composition, and is closely associated with both the binding strength and the pDNA tertiary structure.

  10. Tunable states of interlayer cations in two-dimensional materials

    Energy Technology Data Exchange (ETDEWEB)

    Sato, K.; Numata, K. [Department of Environmental Sciences, Tokyo Gakugei University, Koganei, Tokyo 184-8501 (Japan); Dai, W. [Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education), College of Chemistry, Nankai University, Tianjin 300071 (China); Hunger, M. [Institute of Chemical Technology, University of Stuttgart, 70550 Stuttgart (Germany)

    2014-03-31

    The local state of cations inside the Ångstrom-scale interlayer spaces is one of the controlling factors for designing sophisticated two-dimensional (2D) materials consisting of 2D nanosheets. In the present work, the molecular mechanism on how the interlayer cation states are induced by the local structures of the 2D nanosheets is highlighted. For this purpose, the local states of Na cations in inorganic 2D materials, in which the compositional fluctuations of a few percent are introduced in the tetrahedral and octahedral units of the 2D nanosheets, were systematically studied by means of {sup 23}Na magic-angle-spinning (MAS) nuclear magnetic resonance (NMR) and {sup 23}Na multiple-quantum MAS (MQMAS) NMR spectroscopy. In contrast with an uniform distribution of Na cations expected so far, various well-defined cation states sensitive to the local structures of the 2D nanosheets were identified. The tunability of the interlayer cation states along with the local structure of the 2D nanosheets, as the smallest structural unit of the 2D material, is discussed.

  11. The use of cationic nanogels to deliver proteins to myeloma cells and primary T lymphocytes that poorly express heparan sulfate.

    Science.gov (United States)

    Watanabe, Kozo; Tsuchiya, Yumiko; Kawaguchi, Yoshinori; Sawada, Shin-ichi; Ayame, Hirohito; Akiyoshi, Kazunari; Tsubata, Takeshi

    2011-09-01

    Fusion proteins containing protein transduction domain (PTD) are widely used for intracellular delivery of exogenous proteins. PTD-mediated delivery requires expression of heparan sulfate on the surface of the target cells. However, some of metastatic tumor cells and primary lymphocytes poorly express heparan sulfate. Here we demonstrate that proteins complexed with nanosize hydrogels formed by cationic cholesteryl group-bearing pullulans (cCHP) are efficiently delivered to myeloma cells and primary CD4(+) T lymphocytes probably by induction of macropinocytosis, although these cells are resistant to PTD-mediated protein delivery as a consequence of poor heparan sulfate expression. The anti-apoptotic protein Bcl-xL delivered by cCHP nanogels efficiently blocked apoptosis of these cells, establishing functional regulation of cells by proteins delivered by cCHP nanogels. Thus, cCHP nanogel is a useful tool to deliver proteins for development of new cancer therapy and immune regulation. PMID:21605901

  12. Measuring Apoptosis by Microscopy and Flow Cytometry.

    Science.gov (United States)

    Hollville, Emilie; Martin, Seamus J

    2016-02-02

    Apoptosis is a mode of programmed cell death that plays an important role during development and in the maintenance of tissue homeostasis. Numerous physiological as well as pathological stimuli trigger apoptosis such as engagement of Fas, TRAIL, or TNF receptors, growth factor deprivation, hypoxia, or exposure to cytotoxic drugs. Apoptosis is coordinated from within by members of the caspase family of cysteine proteases that, upon activation, trigger a series of morphological changes including cell shrinkage, extensive plasma membrane blebbing, chromatin condensation, DNA hydrolysis, and nuclear fragmentation. These dramatic structural and biochemical alterations result not only in the controlled dismantling of the cell, but also in the efficient recognition and removal of apoptotic cells by phagocytes. Necrosis, which is typically nonprogrammed or imposed upon the cell by overwhelming membrane or organelle damage, is characterized by rapid plasma membrane rupture followed by organelle and cell swelling. Necrosis is often provoked by infectious agents or a severe departure from physiological conditions. This unit describes protocols for the measurement of apoptosis and for distinguishing apoptosis from necrosis.

  13. Apoptosis signaling pathways and lymphocyte homeostasis

    Institute of Scientific and Technical Information of China (English)

    Guangwu Xu; Yufang Shi

    2007-01-01

    It has been almost three decades since the term "apoptosis" was first coined to describe a unique form of cell death that involves orderly, gene-dependent cell disintegration. It is now well accepted that apoptosis is an essential life process for metazoan animals and is critical for the formation and function of tissues and organs. In the adult mammalian body, apoptosis is especially important for proper functioning of the immune system. In recent years, along with the rapid advancement of molecular and cellular biology, great progress has been made in understanding the mechanisms leading to apoptosis. It is generally accepted that there are two major pathways of apoptotic cell death induction: extrinsic signaling through death receptors that leads to the formation of the death-inducing signaling complex (DISC), and intrinsic signaling mainly through mitochondria which leads to the formation of the apoptosome. Formation of the DISC or apoptosome, respectively, activates initiator and common effector caspases that execute the apoptosis process. In the immune system, both pathways operate; however, it is not known whether they are sufficient to maintain lymphocyte homeostasis. Recently, new apoptotic mechanisms including caspase-independent pathways and granzyme-initiated pathways have been shown to exist in lymphocytes. This review will summarize our understanding of the mechanisms that control the homeostasis of various lymphocyte populations.

  14. NMR exposure sensitizes tumor cells to apoptosis.

    Science.gov (United States)

    Ghibelli, L; Cerella, C; Cordisco, S; Clavarino, G; Marazzi, S; De Nicola, M; Nuccitelli, S; D'Alessio, M; Magrini, A; Bergamaschi, A; Guerrisi, V; Porfiri, L M

    2006-03-01

    NMR technology has dramatically contributed to the revolution of image diagnostic. NMR apparatuses use combinations of microwaves over a homogeneous strong (1 Tesla) static magnetic field. We had previously shown that low intensity (0.3-66 mT) static magnetic fields deeply affect apoptosis in a Ca2+ dependent fashion (Fanelli et al., 1999 FASEBJ., 13;95-102). The rationale of the present study is to examine whether exposure to the static magnetic fields of NMR can affect apoptosis induced on reporter tumor cells of haematopoietic origin. The impressive result was the strong increase (1.8-2.5 fold) of damage-induced apoptosis by NMR. This potentiation is due to cytosolic Ca2+ overload consequent to NMR-promoted Ca2+ influx, since it is prevented by intracellular (BAPTA-AM) and extracellular (EGTA) Ca2+ chelation or by inhibition of plasma membrane L-type Ca2+ channels. Three-days follow up of treated cultures shows that NMR decrease long term cell survival, thus increasing the efficiency of cytocidal treatments. Importantly, mononuclear white blood cells are not sensitised to apoptosis by NMR, showing that NMR may increase the differential cytotoxicity of antitumor drugs on tumor vs normal cells. This strong, differential potentiating effect of NMR on tumor cell apoptosis may have important implications, being in fact a possible adjuvant for antitumor therapies. PMID:16528477

  15. Apoptosis of beta cells in diabetes mellitus.

    Science.gov (United States)

    Anuradha, Rachakatla; Saraswati, Mudigonda; Kumar, Kishore G; Rani, Surekha H

    2014-11-01

    Diabetes mellitus is a multifactorial metabolic disorder characterized by hyperglycemia. Apoptosis in beta cells has been observed in response to diverse stimuli, such as glucose, cytokines, free fatty acids, leptin, and sulfonylureas, leading to the activation of polyol, hexosamine, and diacylglycerol/protein kinase-C (DAG/PKC) pathways that mediate oxidative and nitrosative stress causing the release of different cytokines. Cytokines induce the expression of Fas and tumor necrosis factor-alpha (TNF-α) by activating the transcription factor, nuclear factor-κb, and signal transducer and activator of transcription 1 (STAT-1) in the β cells in the extrinsic pathway of apoptosis. Cytokines produced in beta cells also induce proapoptotic members of the intrinsic pathway of apoptosis. The genetic alterations in apoptosis signaling machinery and the pathogenesis of diabetes include Fas, FasL, Akt, caspases, calpain-10, and phosphatase and tensin homolog (Pten). The other gene products that are involved in diabetes are nitric oxide synthase-2 (NOS2), small ubiquitin-like modifier (SUMO), apolipoprotein CIII (ApoCIII), forkhead box protein O1 (FOXO1), and Kruppel-like zinc finger protein Gli-similar 3 (GLIS3). The gene products having antiapoptotic nature are Bcl-2 and Bcl-XL. Epigenetic mechanisms play an important role in type I and type II diabetes. Further studies on the apoptotic genes and gene products in diabetics may be helpful in pharmacogenomics and individualized treatment along with antioxidants targeting apoptosis in diabetes. PMID:25093391

  16. G0/G1 arrest and apoptosis induced by SARS-CoV 3b protein in transfected cells

    Directory of Open Access Journals (Sweden)

    Chen Jiapei

    2005-08-01

    Full Text Available Abstract Severe Acute Respiratory Syndrome coronavirus (SARS-CoV, cause of the life-threatening atypical pneumonia, infects many organs, such as lung, liver and immune organ, and induces parenchyma cells apoptosis and necrosis. The genome of SARS-CoV, not closely related to any of the previously characterized coronavirus, encodes replicase and four major structural proteins and a number of non-structural proteins. Published studies suggest that some non-structural proteins may play important roles in the replication, virulence and pathogenesis of viruses. Among the potential SARS-CoV non-structural proteins, 3b protein (ORF4 is predicted encoding 154 amino acids, lacking significant similarities to any known proteins. Till now, there is no report about the function of 3b protein. In this study, 3b gene was linked with the EGFP tag at the C- terminus. Through cell cycle analysis, it was found that over-expression of 3b-EGFP protein in Vero, 293 and COS-7 cells could induce cell cycle arrest at G0/G1 phase, and that especially in COS-7 cells, expression of 3b-EGFP was able to induce the increase of sub-G1 phase from 24 h after transfection, which was most obvious at 48 h. The apoptosis induction of 3b fusion protein in COS-7 cells was further confirmed by double cell labeling with 7-AAD and Annexin V, the function of 3b protein inducing cell G0/G1 arrest and apoptosis may provide a new insight for further study on the mechanism of SARS pathogenesis.

  17. Apoptosis in Drosophila: which role for mitochondria?

    Science.gov (United States)

    Clavier, Amandine; Rincheval-Arnold, Aurore; Colin, Jessie; Mignotte, Bernard; Guénal, Isabelle

    2016-03-01

    It is now well established that the mitochondrion is a central regulator of mammalian cell apoptosis. However, the importance of this organelle in non-mammalian apoptosis has long been regarded as minor, mainly because of the absence of a crucial role for cytochrome c in caspase activation. Recent results indicate that the control of caspase activation and cell death in Drosophila occurs at the mitochondrial level. Numerous proteins, including RHG proteins and proteins of the Bcl-2 family that are key regulators of Drosophila apoptosis, constitutively or transiently localize in mitochondria. These proteins participate in the cell death process at different levels such as degradation of Diap1, a Drosophila IAP, production of mitochondrial reactive oxygen species or stimulation of the mitochondrial fission machinery. Here, we review these mitochondrial events that might have their counterpart in human. PMID:26679112

  18. Apoptosis: Therapeutic target in neurodegeneration and sepsis

    Directory of Open Access Journals (Sweden)

    Gonzalo Arboleda

    2005-12-01

    Full Text Available Cellular apoptosis has been considered as themain physiological mechanism underlyingneuronal demise associated to neurodegenerativediseases. Apoptosis has also been described inparenquimal and microvascular endotheliumin the acute phase of sepsis during multi-organicdysfunction. Therefore, strategies aimed toMuerte celular: blanco terapéutico enneurodegeneración y sepsisGonzalo Arboleda*, Luisa M. Matheus†prevent apoptosis (anti-apoptotic represent avaluable tool for prevention and/or retardationof the appearance of clinical symptoms in thesedisorders, which generate a large morbilitymortality,social and economic burden worldwide.The present review is aim to show that antiapoptoticstrategies hold a great therapeuticpotential. In this sense, we will review some ofthese potential therapies such as caspaseinhibitors, activated protein C, Bcl-2 family andthe PI3K/Akt signalling pathway.

  19. Dimerization of two novel apoptosis-inducing proteins and its function in regulating cell apoptosis

    Institute of Scientific and Technical Information of China (English)

    刘青珍; 甘淼; 齐义鹏; 李凌云; 齐兵

    2003-01-01

    Asy (apoptosis/saibousi Yutsudo) is a novel apoptosis-inducing gene found in 1999 by Yutsudo group in Japan. In 2000, Qi Bing et al. cloned another novel gene, named hap (homologue of ASY protein), which encoded the ASY interact ing protein, from human lung cell line (WI-38) cDNA library by using yeast two-h ybrid system. It has been proved that ASY formed homodimer in yeast and human ce ll line, ASY and HAP formed heterodimer in yeast cells, and both induced cell ap optosis in human tumor cell lines Sao2 and CGL4. This paper showed that HAP coul d form homodimer in yeast cells by yeast two-hybrid system; HAP and ASY could pr oduce heterodimer in human cell line by cross-immunoprecipitation test; by using apoptosis-testing technologies such as AnnexinV, TUNEL, DNA ladder and Flow Cyt ometry, the cell apoptosis in human normal or tumor cell lines transfected with hap or asy individually or cotransfected by the both was qualified or quantified . It was firstly demonstrated that ASY or HAP induced cell apoptosis not only in human tumor cell lines, but also in human normal cell lines. Moreover, we prove d that the heterodimer between ASY and HAP decreased apoptosis-inducing activity from the homodimer of ASY or HAP. It revealed that by choosing to form heterodi mer or homodimer between ASY and / or HAP is an important mechanism of regulatin g apoptosis in human cell lines.

  20. Apoptosis de fibroblastos gingivales en periodontitis

    OpenAIRE

    Roger Mauricio Arce; Oscar Tamayo; Armando Cortés

    2007-01-01

    Introducción: Los fibroblastos gingivales humanos (FGH) tienen un papel importante en la enfermedad periodontal, pues alteran su normal funcionamiento en respuesta a estímulos pro-inflamatorios. Se cree que los fibroblastos se pueden eliminar anormalmente por medio de apoptosis en periodontitis. El propósito de este estudio es determinar y cuantificar la apoptosis de FGH en biopsias del periodonto de individuos sanos y con enfermedad periodontal. Métodos: Se realizó un estudio clínico descrip...

  1. Apoptosis induced by dioscin in Hela cells.

    Science.gov (United States)

    Cai, Jing; Liu, Mingjie; Wang, Zhao; Ju, Yong

    2002-02-01

    Dioscin, a saponin extracted from the root of Polygonatum Zanlanscianense Pamp, markedly inhibited proliferation of Hela cells. The results indicated that Hela cells underwent apoptosis in dose- and time-dependent manners when treated with Dioscin. Caspase-3, -8 and -9 activities were also detected. The low enzymatic activity of caspase-8 and high activity of caspase-9 showed that the mitochondrial pathway was activated in apoptosis. The reduced expression of the survival protein Bcl-2 also confirmed this result. These studies may be significant in finding a new drug to treat human cervical cancer. PMID:11853164

  2. Ultrashort cationic lipopeptides and lipopeptoids: Evaluation and mechanistic insights against epithelial cancer cells.

    Science.gov (United States)

    Domalaon, Ronald; Findlay, Brandon; Ogunsina, Makanjuola; Arthur, Gilbert; Schweizer, Frank

    2016-10-01

    Peptides present an attractive scaffold for the development of new anticancer lead agents due to their accessibility and ease of modification. Synthetic ultrashort cationic lipopeptides, with four amino acids or less conjugated to a fatty acid, were developed to retain the biological activity of longer peptides in a smaller molecular size. Herein, we report the activity of amphiphilic lipotripeptides, lipotripeptoids and lipotetrapeptides against breast (MDA-MB-231, JIMT-1), prostate (DU145) and pancreas (MiaPaCa2) epithelial cancer cell lines. The lipotripeptide C16-KKK-NH2 and lipotetrapeptide C16-PCatPHexPHexPCat-NH2 were identified to possess anticancer activity. The latter lipotetrapeptide possess a short polyproline scaffold consisting of only two L-4R-aminoproline (PCat) and two L-4R-hexyloxyproline (PHex). However, all the prepared lipotripeptoids lack anticancer activity. The amphiphilic C16-PCatPHexPHexPCat-NH2 exhibited similar anticancer potency to the surfactant benzethonium chloride while superior activity was observed in comparison to myristylamine. Mechanistic studies revealed that the peptides do not lyse ovine erythrocytes nor epithelial cancer cells, thus ruling out necrosis as the mechanism of cell death. Surprisingly, the two lipopeptides exhibit different mechanisms of action that result in cancer cell death. The lipotripeptide C16-KKK-NH2 was found to induce caspase-mediated apoptosis while C16-PCatPHexPHexPCat-NH2 kills tumor cells independent of caspases. PMID:27486068

  3. Cationic amino acid transporter 2 enhances innate immunity during Helicobacter pylori infection.

    Directory of Open Access Journals (Sweden)

    Daniel P Barry

    Full Text Available Once acquired, Helicobacter pylori infection is lifelong due to an inadequate innate and adaptive immune response. Our previous studies indicate that interactions among the various pathways of arginine metabolism in the host are critical determinants of outcomes following infection. Cationic amino acid transporter 2 (CAT2 is essential for transport of L-arginine (L-Arg into monocytic immune cells during H. pylori infection. Once within the cell, this amino acid is utilized by opposing pathways that lead to elaboration of either bactericidal nitric oxide (NO produced from inducible NO synthase (iNOS, or hydrogen peroxide, which causes macrophage apoptosis, via arginase and the polyamine pathway. Because of its central role in controlling L-Arg availability in macrophages, we investigated the importance of CAT2 in vivo during H. pylori infection. CAT2(-/- mice infected for 4 months exhibited decreased gastritis and increased levels of colonization compared to wild type mice. We observed suppression of gastric macrophage levels, macrophage expression of iNOS, dendritic cell activation, and expression of granulocyte-colony stimulating factor in CAT2(-/- mice suggesting that CAT2 is involved in enhancing the innate immune response. In addition, cytokine expression in CAT2(-/- mice was altered from an antimicrobial Th1 response to a Th2 response, indicating that the transporter has downstream effects on adaptive immunity as well. These findings demonstrate that CAT2 is an important regulator of the immune response during H. pylori infection.

  4. Treating colon cancer with a suicide gene delivered by self-assembled cationic MPEG-PCL micelles

    Science.gov (United States)

    Duan, Xingmei; Wang, Pan; Men, Ke; Gao, Xiang; Huang, Meijuan; Gou, Maling; Chen, Lijuan; Qian, Zhiyong; Wei, Yuquan

    2012-03-01

    Biodegradable cationic micelles show promise for applications in gene delivery. In this article, we used DOTAP to modify monomethoxy poly(ethylene glycol)-poly(ε-caprolactone) (MPEG-PCL, MP) micelles in one step, creating novel cationic self-assembled DOTAP and MPEG-PCL hybrid micelles (DMP). These micelles had a mean particle size of 46 +/- 5.6 nm and a zeta potential of 41.8 +/- 0.5 mV, and had the capacity to bind DNA. Compared with PEI25K (the gold standard), DMP micelles had higher transfection efficiency and lower cytotoxicity. Moreover, we used DMP to deliver the Survivin-T34A gene (S-T34A, a suicide gene) to treat colon cancer. DMP delivered the Survivin-T34A gene (DMP/S-T34A) and could induce apoptosis in cancer cells, resulting in inhibition of the growth of C-26 colon cancer cells in vitro. An in vivo study indicated that intraperitoneal administration of DMP micelles delivered the Survivin-T34A gene and efficiently inhibited the growth of abdominal metastatic C-26 colon cancer and the malignant ascites. These data suggest that DMP may be a novel gene carrier, and its delivery of the S-T34A gene may have promising applications in the treatment of colon cancer.

  5. Stress response and apoptosis in pro- and antiinflammatory macrophages.

    Science.gov (United States)

    Malyshev, I Yu; Kruglov, S V; Bakhtina, L Yu; Malysheva, E V; Zubin, M; Norkin, M

    2004-08-01

    We showed that stress response and apoptosis in macrophages depend on the phenotype of their secretory activity and specific biological and physical characteristics of the factor inducing stress-response or apoptosis.

  6. Sustained release of hepatocyte growth factor by cationic self-assembling peptide/heparin hybrid hydrogel improves β-cell survival and function through modulating inflammatory response

    Science.gov (United States)

    Liu, Shuyun; Zhang, Lanlan; Cheng, Jingqiu; Lu, Yanrong; Liu, Jingping

    2016-01-01

    Inflammatory response is a major cause of grafts dysfunction in islet transplantation. Hepatocyte growth factor (HGF) had shown anti-inflammatory activity in multiple diseases. In this study, we aim to deliver HGF by self-assembling peptide/heparin (SAP/Hep) hybrid gel to protect β-cell from inflammatory injury. The morphological and slow release properties of SAPs were analyzed. Rat INS-1 β-cell line was treated with tumor necrosis factor α in vitro and transplanted into rat kidney capsule in vivo, and the viability, apoptosis, function, and inflammation of β-cells were evaluated. Cationic KLD1R and KLD2R self-assembled to nanofiber hydrogel, which showed higher binding affinity for Hep and HGF because of electrostatic interaction. Slow release of HGF from cationic SAP/Hep gel is a two-step mechanism involving binding affinity with Hep and molecular diffusion. In vitro and in vivo results showed that HGF-loaded KLD2R/Hep gel promoted β-cell survival and insulin secretion, and inhibited cell apoptosis, cytokine release, T-cell infiltration, and activation of NFκB/p38 MAPK pathways in β-cells. This study suggested that SAP/Hep gel is a promising carrier for local delivery of bioactive proteins in islet transplantation. PMID:27729786

  7. A novel method for detection of apoptosis

    Energy Technology Data Exchange (ETDEWEB)

    Zagariya, Alexander M., E-mail: zagariya@uic.edu

    2012-04-15

    There are two different Angiotensin II (ANG II) peptides in nature: Human type (ANG II) and Bovine type (ANG II*). These eight amino acid peptides differ only at position 5 where Valine is replaced by Isoleucine in the Bovine type. They are present in all species studied so far. These amino acids are different by only one atom of carbon. This difference is so small, that it will allow any of ANG II, Bovine or Human antibodies to interact with all species and create a universal method for apoptosis detection. ANG II concentrations are found at substantially higher levels in apoptotic, compared to non-apoptotic, tissues. ANG II accumulation can lead to DNA damage, mutations, carcinogenesis and cell death. We demonstrate that Bovine antiserum can be used for universal detection of apoptosis. In 2010, the worldwide market for apoptosis detection reached the $20 billion mark and significantly increases each year. Most commercially available methods are related to Annexin V and TUNNEL. Our new method based on ANG II is more widely known to physicians and scientists compared to previously used methods. Our approach offers a novel alternative for assessing apoptosis activity with enhanced sensitivity, at a lower cost and ease of use.

  8. Calpain Activator Dibucaine Induces Platelet Apoptosis

    Directory of Open Access Journals (Sweden)

    Jun Liu

    2011-03-01

    Full Text Available Calcium-dependent calpains are a family of cysteine proteases that have been demonstrated to play key roles in both platelet glycoprotein Ibα shedding and platelet activation and altered calpain activity is associated with thrombotic thrombocytopenic purpura. Calpain activators induce apoptosis in several types of nucleated cells. However, it is not clear whether calpain activators induce platelet apoptosis. Here we show that the calpain activator dibucaine induced several platelet apoptotic events including depolarization of the mitochondrial inner transmembrane potential, up-regulation of Bax and Bak, down-regulation of Bcl-2 and Bcl-XL, caspase-3 activation and phosphatidylserine exposure. Platelet apoptosis elicited by dibucaine was not affected by the broad spectrum metalloproteinase inhibitor GM6001. Furthermore, dibucaine did not induce platelet activation as detected by P-selectin expression and PAC-1 binding. However, platelet aggregation induced by ristocetin or α-thrombin, platelet adhesion and spreading on von Willebrand factor were significantly inhibited in platelets treated with dibucaine. Taken together, these data indicate that dibucaine induces platelet apoptosis and platelet dysfunction.

  9. Techniques to Distinguish Apoptosis from Necroptosis.

    Science.gov (United States)

    Feoktistova, Maria; Wallberg, Fredrik; Tenev, Tencho; Geserick, Peter; Leverkus, Martin; Meier, Pascal

    2016-04-01

    The processes by which cells die are as tightly regulated as those that govern cell growth and proliferation. Recent studies of the molecular pathways that regulate and execute cell death have uncovered a plethora of signaling cascades that lead to distinct modes of cell death, including "apoptosis," "necrosis," "autophagic cell death," and "mitotic catastrophe." Cells can readily switch from one form of death to another; therefore, it is vital to have the ability to monitor the form of death that cells are undergoing. A number of techniques are available that allow the detection of cell death and when combined with either knockdown approaches or inhibitors of specific signaling pathways, such as caspase or RIP kinase pathways, they allow the rapid dissection of divergent cell death pathways. However, techniques that reveal the end point of cell death cannot reconstruct the sequence of events that have led to death; therefore, they need to be complemented with methods that can distinguish all forms of cell death. Apoptotic cells frequently undergo secondary necrosis under in vitro culture conditions; therefore, novel methods relying on high-throughput time-lapse fluorescence video microscopy are necessary to provide temporal resolution to cell death events. Further, visualizing the assembly of multiprotein signaling hubs that can execute apoptosis or necroptosis helps to explore the underlying processes. Here we introduce a suite of techniques that reliably distinguish necrosis from apoptosis and secondary necrosis, and that enable investigation of signaling platforms capable of instructing apoptosis or necroptosis. PMID:27037077

  10. Wnt signaling control of bone cell apoptosis

    Institute of Scientific and Technical Information of China (English)

    Peter V N Bodine

    2008-01-01

    Wnts are a large family of growth factors that mediate essential biological processes like embryogenesis, morphogenesis and organogenesis. These proteins also play a role in oncogenesis, and they regulate apoptosis in many tissues. Wnts bind to a membrane receptor complex comprised of a frizzled (FZD) G-protein-coupled receptor and a low-density , lipoprotein (LDL) receptor-related protein (LRP). The formation of this ligand-receptor complex initiates a number of signaling cascades that include the canonical/beta-catenin pathway as well as several noncanonical pathways. In recent years, canonical Wnt signaling has been reported to play a significant role in the control of bone formation. Clinical studies have found that mutations in LRP-5 are associated with reduced bone mineral density (BMD) and fractures. Investigations of knockout and transgenic mouse models of Wnt pathway components have shown that canonical Wnt signaling modulates most aspects of osteoblast physiology including proliferation, differentiation, function and apoptosis. Transgenic mice expressing a gain of function mutant of LRP-5 in bone, or mice lacking the Wnt antagonist secreted frizzled-related protein-1, exhibit elevated BMD and suppressed osteoblast apoptosis. In addition, preclinical studies with pharmacologic compounds such as those that inhibit glycogen synthase kinase-3p support the importance of the canonical Wnt pathway in modulation of bone formation and osteoblast apoptosis.

  11. Bacterial DNA delays human eosinophil apoptosis

    OpenAIRE

    Ilmarinen, Pinja; Hasala, Hannele; Sareila, Outi; Moilanen, Eeva; Kankaanranta, Hannu

    2009-01-01

    Bacterial DNA delays human eosinophil apoptosis correspondance: Corresponding author. Tel.: +358 3 3551 6687; fax: +358 3 3551 8082. (Ilmarinen, Pinja) (Ilmarinen, Pinja) The Immunopharmacology Research Group--> , Medical School--> , University of Tampere and Research Unit--> , Tampere University Hospital--> , Tampere--> - FINLAND (Ilmarinen, Pinja) The Immunopharmacology ...

  12. Inhibitor of apoptosis proteins: new therapeutic targets in hematological cancer?

    NARCIS (Netherlands)

    Graaf, A.O. de; Witte, T.J.M. de; Jansen, J.H.

    2004-01-01

    Apoptosis is an essential process for the selection and survival of lymphocytes. Resistance to apoptosis can promote malignant transformation of hematopoietic cells. Proteins that regulate apoptosis may therefore be critically involved in the development of hematological cancer. A delicate balance b

  13. A covalent attraction between two molecular cation TTF·~+

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    The optimized structure of the tetrathiafulvalence radical-cation dimer(TTF·+-TTF·+) with all-real frequencies is obtained at MP2/6-311G level,which exhibits the attraction between two molecular cation TTF·+.The new attraction interaction is a 20-center-2-electron intermolecular covalent π /π bonding with a telescope shape.The covalent π /π bonding has the bonding energy of about -21 kcal·mol-1 and is concealed by the Coulombic repulsion between two TTF·+ cations.This intermolecular covalent attraction also influences the structure of the TTF·+ subunit,i.e.,its molecular plane is bent by an angle θ=5.6°.This work provides new knowledge on intermolecular interaction.

  14. Cationic lipids delay the transfer of plasmid DNA to lysosomes.

    Science.gov (United States)

    Wattiaux, R; Jadot, M; Laurent, N; Dubois, F; Wattiaux-De Coninck, S

    1996-10-14

    Plasmid 35S DNA, naked or associated with different cationic lipid preparations was injected to rats. Subcellular distribution of radioactivity in the liver one hour after injection, was established by centrifugation methods. Results show that at that time, 35S DNA has reached lysosomes. On the contrary, when 35S DNA was complexed with lipids, radioactivity remains located in organelles whose distribution after differential and isopycnic centrifugation, is clearly distinct from that of arylsulfatase, lysosome marker enzyme. Injection of Triton WR 1339, a specific density perturbant of lysosomes, four days before 35S DNA injection causes a density decrease of radioactivity bearing structures, apparent one hour after naked 35S DNA injection but visible only after more than five hours, when 35S DNA associated with a cationic lipid is injected. These observations show that cationic lipids delay the transfer to lysosomes, of plasmid DNA taken up by the liver.

  15. Cationization of Alpha-Cellulose to Develop New Sustainable Products

    Directory of Open Access Journals (Sweden)

    Ana Moral

    2015-01-01

    Full Text Available Papermaking has been using high quantities of retention agents, mainly cationic substances and organic compounds such as polyamines. The addition of these agents is related to economic and environmental issues, increasing contamination of the effluents. The aim of this work is to develop a cationic polymer for papermaking purposes based on the utilization of alpha-cellulose. The cationization of mercerized alpha-cellulose with 3-chloro-2-hydroxypropyltrimethylammonium chloride (CHPTAC is governed by a pseudo-second-order reaction. The initial amorphous fraction of cellulose is reacted with CHPTAC until the equilibrium value of nitrogen substitution is reached. Nitrogen is incorporated as a quaternary ammonium group in the polymer. Also, the kinetic constant increased with decreasing crystallinity index, showing the importance of the previous alkalization stage. The use of modified natural polysaccharides is a sustainable alternative to synthetic, nonbiodegradable polyelectrolytes and thus is desirable with a view to developing new products and new processes.

  16. Theoretical Studies on the Interactions of Cations with Diazine

    Institute of Scientific and Technical Information of China (English)

    CHEN Xing; WU Wen-Peng; ZHANG Jing-Lai; CAO Ze-Xing

    2006-01-01

    Density functional theory and MP2 calculations have been used to determine the geometries, stabilities, binding energies, and dissociative properties of cation-diazine complexes Mn+-C4H4N2 (Mn+ = Li+, B+, Al+, Be2+, Mg2+, Ca2+). The calculated results indicate that most complexes are stable except the π complexes of Ca2+-pyridazine, Ca2+-pyrazine, Al+-pyrimidine and Al+-pyrimidine. The σ complexes are generally much more stable than their π counterparts. Among the π complexes, the cation-pyrazine π complexes have slightly higher stability. The nature of the ion-molecule interactions has been discussed by the natural bond orbital analysis and frontier molecular orbital interactions. In these σ complexes, there is stronger covalent interaction between B+ and diazine. In the selected π complexes, B+ and Be2+ have stronger covalent interaction with diazine, while the other cations mainly have electrostatic interaction with diazine.

  17. Surface hopping investigation of the relaxation dynamics in radical cations

    Energy Technology Data Exchange (ETDEWEB)

    Assmann, Mariana; Matsika, Spiridoula, E-mail: smatsika@temple.edu [Department of Chemistry, Temple University, Philadelphia, Pennsylvania 19122 (United States); Weinacht, Thomas [Department of Physics, Stony Brook University, Stony Brook, New York 11794 (United States)

    2016-01-21

    Ionization processes can lead to the formation of radical cations with population in several ionic states. In this study, we examine the dynamics of three radical cations starting from an excited ionic state using trajectory surface hopping dynamics in combination with multiconfigurational electronic structure methods. The efficiency of relaxation to the ground state is examined in an effort to understand better whether fragmentation of cations is likely to occur directly on excited states or after relaxation to the ground state. The results on cyclohexadiene, hexatriene, and uracil indicate that relaxation to the ground ionic state is very fast in these systems, while fragmentation before relaxation is rare. Ultrafast relaxation is facilitated by the close proximity of electronic states and the presence of two- and three-state conical intersections. Examining the properties of the systems in the Franck-Condon region can give some insight into the subsequent dynamics.

  18. Strong and specific effects of cations on lysozyme chloride solubility.

    Science.gov (United States)

    Bénas, Philippe; Legrand, Laurent; Riès-Kautt, Madeleine

    2002-10-01

    The influence of salt nature and concentration on tetragonal lysozyme chloride crystal solubility is presented for a set of mono-, di- and trivalent cations (Cs(+), Rb(+), Mn(2+), Co(2+) and Yb(3+)). The results show that cations have as strong an effect on protein solubility as anions and that they present their own particular effects as co-ions. Indeed, after decreasing at low ionic strength, lysozyme solubility increases with high concentration of polyvalent cations, probably due to co-ion binding and therefore the concomitant increase of the net charge of the protein-salt complex. These new results are discussed in order to progress in the understanding of the crystallisation process at the atomic level. PMID:12351866

  19. A covalent attraction between two molecular cation TTF·~+

    Institute of Scientific and Technical Information of China (English)

    WANG FangFang; WANG Yi; WANG BingQiang; WANG YinFeng; MA Fang; Li ZhiRu

    2009-01-01

    The optimized structure of the tetrathiafulvalence radical-cation dimer (TTF·~+-TTF·~+) with all-real frequencies is obtained at MP2/6-311G level,which exhibits the attraction between two molecular cation TTF·~+.The new attraction interaction is a 20-center-2-electron intermolecular covalent π/π bonding with a telescope shape.The covalent π/π bonding has the bonding energy of about-21 kcal·mol~(-1) and is concealed by the Coulombic repulsion between two TTF·~+ cations.This intermolecular covalent attraction also influences the structure of the TTF·~+ subunit,I.e.,its molecular plane is bent by an angle θ=5.6°.This work provides new knowledge on intermolecular interaction.

  20. Low-Temperature Cationic Rearrangement in a Bulk Metal Oxide.

    Science.gov (United States)

    Li, Man-Rong; Retuerto, Maria; Stephens, Peter W; Croft, Mark; Sheptyakov, Denis; Pomjakushin, Vladimir; Deng, Zheng; Akamatsu, Hirofumi; Gopalan, Venkatraman; Sánchez-Benítez, Javier; Saouma, Felix O; Jang, Joon I; Walker, David; Greenblatt, Martha

    2016-08-16

    Cationic rearrangement is a compelling strategy for producing desirable physical properties by atomic-scale manipulation. However, activating ionic diffusion typically requires high temperature, and in some cases also high pressure in bulk oxide materials. Herein, we present the cationic rearrangement in bulk Mn2 FeMoO6 at unparalleled low temperatures of 150-300 (o) C. The irreversible ionic motion at ambient pressure, as evidenced by real-time powder synchrotron X-ray and neutron diffraction, and second harmonic generation, leads to a transition from a Ni3 TeO6 -type to an ordered-ilmenite structure, and dramatic changes of the electrical and magnetic properties. This work demonstrates a remarkable cationic rearrangement, with corresponding large changes in the physical properties in a bulk oxide at unprecedented low temperatures. PMID:27203790

  1. Modeling cation exchange using EQ3/6

    International Nuclear Information System (INIS)

    Geochemical modeling codes must be able to predict solid-solution and ion-exchange behavior of zeolites and smectites in order to design and assess strategies for containing and cleaning up toxic and/or radioactive wastes. Cation-exchange and solid-solution models have been implemented in the EQ3/6 geochemical modeling package and used to predict the composition of clinoptilolite under a variety of conditions. Published free energies of cation exchange on clinoptilolite at 25 degrees C were combined with the calorimetric data for clinoptilolite to derive free energies of formation of the component end members of a solid solution in which mixing is allowed only on the exchange site. The solid-solution model and component end-member data were incorporated into EQ3/6 and its data base. An option to treat cation exchange independently of the solid-solution model was also developed and implemented in EQ3/6. This option allows the user to model mixed-phase exchangers, multisite exchangers, and systems in which the exchanger is not in overall equilibrium with the solution. Two open-quotes idealclose quotes cation-exchange conventions [Vanselow (mole fraction) and Gapon (equivalent fraction)] are currently implemented in the code. A description of the cation-exchange models and their implementation into EQ3/6 is presented, and the relationship between the exchange formalisms and the solid-solution models is discussed. The advantages and limitations of the models and currently available thermodynamic data are addressed by comparing cation-exchange compositions of clinoptilolites with (1) published binary exchange data; (2) compositions of coexisting clinoptilolites and formation waters at Yucca Mountain; and (3) experimental sorption isotherms of Cs and Sr on zeolitized tuff

  2. THE APPLICATION OF CATIONIC POLYACRYLAMIDE AS DRAINAGE AND RETENTION AIDS

    Institute of Scientific and Technical Information of China (English)

    Jin Wang; Kefu Chen; Fushan Chen; Chuanshan Zhao; Rendang Yang

    2004-01-01

    Cationic polyacrylamide (CPAM) which was prepared through complex initiation system in laboratory and cationic polyacrylamide (Ciba) were used as retention and drainage aids for bleached wheat straw pulp. The influences of (polydiallyldimethlammonium chloride) PDADMAC and PDADMAC/CPAM on Zeta potential and drainability of pulp was investigated. The dual drainage and retention systems such as CPAM/modified bentonite, CPAM/colloidal SiO2,as well as their comparison between the two systems were discussed, and the optimal dosages of additives were determined. The results showed that: the complex systems can further enhance filler retention,drainability of pulp and strength properties of paper.

  3. Cationically polymerizable monomers derived from renewable sources. Annual performance report

    Energy Technology Data Exchange (ETDEWEB)

    Crivello, J.V.

    1992-10-01

    The objectives of this project are to design and synthesize novel monomers which orginate from renewable biological sources and to carry out their rapid, efficient, pollution-free and energy efficient cationic polymerization to useful products under the influence of ultraviolet light or heat. A summary of the results of the past year`s research on cationically polymerizable monomers derived from renewable sources is presented. Three major areas of investigation corresponding to the different classes of naturally occurring starting materials were investigated; epoxidized terpenes and natural rubber and vinyl ethers from alcohols and carbohydrates.

  4. Radiation-induced cationic curing of vinyl ethers

    International Nuclear Information System (INIS)

    Recently there has been an increasing interest in nonacrylate radiation-curable coatings. Vinyl ethers are particularly reactive under cationic polymerization reaction conditions. The high efficiency of the photoacid initiators combined with the high reactivity of vinyl ether monomers makes this a potentially very useful system. This chapter discusses the preparation of vinyl ethers, introduces vinyl ether-functional monomers and oligomers, describes radiation-induced cationic polymerization of vinyl ethers, and discusses various coating systems. Throughout the chapter, an emphasis is placed on radiation-curable coating applications. 64 refs., 5 figs., 11 tabs

  5. Crystal structure of channelrhodopsin, a light-gated cation channel – all cations lead through the monomer –

    OpenAIRE

    Kato, Hideaki E.; Nureki, Osamu

    2013-01-01

    Channelrhodopsin (ChR) is a light-gated cation channel derived from green algae. Since the inward flow of cations triggers the neuron firing, neurons expressing ChRs can be optically controlled even within freely moving mammals. Although ChR has been broadly applied to neuro-science research, little is known about its molecular mechanisms. We determined the crystal structure of chimeric ChR at 2.3 Å resolution and revealed its molecular architecture. The integration of structural, electrophys...

  6. pH dependent transfer of nano-pores into membrane of cancer cells to induce apoptosis

    Science.gov (United States)

    Wijesinghe, Dayanjali; Arachchige, Mohan C. M.; Lu, Andrew; Reshetnyak, Yana K.; Andreev, Oleg A.

    2013-12-01

    Proper balance of ions in intracellular and extracellular space is the key for normal cell functioning. Changes in the conductance of membranes for ions will lead to cell death. One of the main differences between normal and cancerous cells is the low extracellular pHe and the reverse pH gradient: intracellular pHi is higher than extracellular pHe. We report here pH-selective transfer of nano-pores to cancer cells for the dis-regulation of balance of monovalent cations to induce cell death at mildly acidic pHe as it is in most solid tumors. Our approach is based on the pH-sensitive fusion of cellular membrane with the liposomes containing gramicidin A forming cation-conductive β-helix in the membrane. Fusion is promoted only at low extracellular pH by the pH (Low) Insertion Peptide (pHLIP®) attached to the liposomes. Gramicidin channels inserted into the cancer cells open flux of protons into the cytoplasm and disrupt balance of other monovalent cations, which induces cell apoptosis.

  7. Regulatory mechanisms of apoptosis in regularly dividing cells

    Directory of Open Access Journals (Sweden)

    Ribal S Darwish

    2010-08-01

    Full Text Available Ribal S DarwishDepartment of Anesthesiology, Division of Critical Care Medicine, University of Maryland Medical Center, Baltimore, Maryland, USAAbstract: The balance between cell survival and death is essential for normal development and homeostasis of organisms. Apoptosis is a distinct type of cell death with ultrastructural features that are consistent with an active, inherently controlled process. Abnormalities and ­dysregulation of apoptosis contribute to the pathophysiology of multiple disease processes. Apoptosis is strictly regulated by several positive and negative feedback mechanisms that regulate cell death and determine the final outcome after cell exposure to apoptotic stimuli. Mitochondria and caspases are central components of the regulatory mechanisms of ­apoptosis. Recently, noncaspase pathways of apoptosis have been explored through the studies of ­apoptosis-inducing factor and endonuclease G. Multiple difficulties in the apoptosis research relate to apoptosis detection and imaging. This article reviews current understanding of the regulatory mechanisms of apoptosis.Keywords: caspases, apoptosis-inducing factor, apoptosis inhibitory proteins, cytochrome c, mitochondria 

  8. Paclitaxel induces apoptosis in human gastric carcinoma cells

    Institute of Scientific and Technical Information of China (English)

    Hai-Bo Zhou; Ju-Ren Zhu

    2003-01-01

    AIM: To investigate the apoptosis in gastric cancer cells induced by paclitaxel, and the relation between this apoptosis and expression of Bcl-2 and Bax.METHODS: In in vitro experiments, MTT assay was used to determine the cell growth inhibitory rate. Transmission electron microscope and TUNEL staining method were used to quantitatively and qualitively detect the apoptosis status of gastric cancer cell line SGC-7901 before and after the paditaxel treatment. Immunohistochemical staining was used to detect the expression of apoptosis-regulated gene Bcl-2and Bax.RESULTS: Paclitaxel inhibited the growth of gastric cancer cell line SGC-7901 in a dose-and time-dependent manner.Paclitaxel induced SGC-7901 cells to undergo apoptosis with typically apoptotic characteristics, including morphological changes of chromatin condensation, chromatin crescent formation, nucleus fragmentation and apoptotic body formation. Paclitaxel could reduce the expression of apoptosis-regulated gene Bcl-2, and improve the expression of apoptosis-regulated gene Bax.CONCLUSION: Paclitaxel is able to induce the apoptosis in gastric cancer. This apoptosis may be mediated by downexpression of apoptosis-regulated gene Bcl-2 and upexpression of apoptosis-regulated gene Bax.

  9. Calcium paradox induces apoptosis in the isolated perfused Rana ridibunda heart: involvement of p38-MAPK and calpain.

    Science.gov (United States)

    Aggeli, Ioanna-Katerina; Zacharias, Triantafyllos; Papapavlou, Georgia; Gaitanaki, Catherine; Beis, Isidoros

    2013-12-01

    "Calcium paradox" as a term describes the deleterious effects conferred to a heart perfused with a calcium-free solution followed by repletion, including loss of mechanical activity and sarcomere disruption. Given that the signaling mechanisms triggered by calcium paradox remain elusive, in the present study, we tried to investigate them in the isolated perfused heart from Rana ridibunda. Calcium paradox was found to markedly activate members of the MAPKs (p43-ERK, JNKs, p38-MAPK). In addition to lactate dehydrogenase (LDH) release in the perfusate (indicative of necrosis), we also confirmed the occurrence of apoptosis by using the TUNEL assay and identifying poly(ADP-ribose) polymerase (PARP) fragmentation and upregulated Bax expression. Furthermore, using MDL28170 (a selective calpain inhibitor), a role for this protease was revealed. In addition, various divalent cations were shown to exert a protective effect against the calcium paradox. Interestingly, SB203580, a p38-MAPK inhibitor, alleviated calcium-paradox-conferred apoptosis. This result indicates that p38-MAPK plays a pro-apoptotic role, contributing to the resulting myocardial dysfunction and cell death. To our knowledge, this is the first time that the calcium paradox has been shown to induce apoptosis in amphibians, with p38-MAPK and calpain playing significant roles.

  10. Planar Homotropenylium Cation : A Transition State with Reversed Aromaticity

    NARCIS (Netherlands)

    Gibson, Christopher M.; Havenith, Remco W. A.; Fowler, Patrick W.; Jenneskens, Leonardus W.

    2015-01-01

    In contrast to the equilibrium structure of the homoaromatic C-s homotropenylium cation, C8H9+ (1), which supports a pinched diatropic ring current, the C(2)v transition state (2) for inversion of the methylene bridge of 1 is antiaromatic and supports a two-lobe paratropic pi current, as detected by

  11. Inward Cationic Diffusion and Percolation Transition in Glass-Ceramics

    DEFF Research Database (Denmark)

    Smedsklaer, Morten Mattrup; Yue, Yuanzheng; Mørup, Steen

    2010-01-01

    We show the quantitative correlation between the degree of crystallization and the cationic diffusion extent in iron-containing diopside glass–ceramics at the glass transition temperature. We find a critical degree of crystallization, above which the diffusion extent sharply drops with the degree...

  12. Cationic zinc enolates as highly active catalysts for acrylate polymerization.

    Science.gov (United States)

    Garner, Logan E; Zhu, Hongping; Hlavinka, Mark L; Hagadorn, John R; Chen, Eugene Y-X

    2006-11-22

    Unprecedented cationic zinc enolates have been generated by a novel activation route involving the amido to imino ligand transformation with B(C6F5)3, structurally characterized, and utilized as highly active catalysts for the production of high molecular weight polyacrylates at ambient temperature. PMID:17105289

  13. Cationic amphiphilic non-hemolytic polyacrylates with superior antibacterial activity.

    Science.gov (United States)

    Punia, Ashish; He, Edward; Lee, Kevin; Banerjee, Probal; Yang, Nan-Loh

    2014-07-01

    Acrylic copolymers with appropriate compositions of counits having cationic charge with 2-carbon and 6-carbon spacer arms can show superior antibacterial activities with concomitant very low hemolytic effect. These amphiphilic copolymers represent one of the most promising synthetic polymer antibacterial systems reported. PMID:24854366

  14. Biosorption of radiocesium by deinococcus radiodurans influenced by cations

    International Nuclear Information System (INIS)

    Deinococcus radiodurans has a strong ability to withstand high doses of radiation, which makes it as an ideal candidate for bioremediation of sites contaminated with radionuclides and toxic chemicals. However, no data is available on whether D. radiodurans has a specific sorption capacity to radiocesium for bioremediation purpose. The radiocesium biosorption capacity of live cells of D. radiodurans in the presence of other interfering cations was investigated. The maximum biosorption capacity of radiocesium by D. radiodurans in equilibrium state was about 2,100 kBq/kg (fresh weight basis). Among the tested monovalent cations, NH4+ had the strongest antagonism on 134Cs biosorption for D. radiodurans. However, this antagonism could only be observed at a concentration as high as 100 mmol/L. Divalent cations, such as Ca2+ and Pb2+ could reduced the biosorption of radiocesium by D. radiodurans. Al3+ and Cr3+ were cytotoxic to D. radiodurans cells, the growth of D. radiodurans cells was inhibited when the concentrations of these cations were greater than 1 mmol/L. (authors)

  15. Cation Hydration Constants by Proton NMR: A Physical Chemistry Experiment.

    Science.gov (United States)

    Smith, Robert L.; And Others

    1988-01-01

    Studies the polarization effect on water by cations and anions. Describes an experiment to illustrate the polarization effect of sodium, lithium, calcium, and strontium ions on the water molecule in the hydration spheres of the ions. Analysis is performed by proton NMR. (MVL)

  16. Versatile cation transport in imidazolium based polymerized ionic liquids

    Science.gov (United States)

    Evans, Christopher; Segalman, Rachel

    Polymerized ionic liquids (PIL) with tethered imidazolium groups are able to conduct a diverse array of cations relevant for energy applications. The well-known complexation of imidazolium with transition metals is exploited to bind ions such as H +, Li+, Cu2+, and Ni2+ by doping the neutral PIL with the appropriate Cation-TFSI- salt. Conductivities were first determined via AC impedance indicating that H+ salts lead to the highest conductivity (due to low ion mass and potential Grotthus mechanism) followed by Cu2+, Li+, Ag+, and Ni2+. The equilibrium constant for imidazolium complexation is larger for Cu2+ relative to Li-, Ag-, and Ni-imidazolium complexes leading to greater salt dissociation and higher conductivities. For LiTFSI and CuTFSI2 salts, metallic lithium or copper electrodes were employed in battery cells to pass a steady DC current and confirm that the cations are in fact carrying current. Interestingly, the divalent Cu2+ also ionically crosslinks the polymer leading to a plateau in the viscosity. Thus, divalent ions provide an unique route to high conductivity, high modulus polymeric electrolytes. Future studies involving ZnTFSI2 and MgTFSI2 for battery applications are proposed to examine how versatile the PIL platform is for cation transport.

  17. Denatured Thermodynamics of Proteins in Weak Cation-exchange Chromatography

    Institute of Scientific and Technical Information of China (English)

    LI Rong; CHEN Guo-Liang

    2003-01-01

    The thermostability of some proteins in weak cation-exchange chromatography was investigated at 20-80 ℃. The results show that there is a fixed thermal denaturation transition temperature for each protein. The appearance of the thermal transition temperature indicates that the conformations of the proteins are destroyed seriously. The thermal behavior of the proteins in weak cation-exchange and hydrophobic interaction chromatographies were compared in a wide temperature range. It was found that the proteins have a higher thermostability in a weak cation-exchange chromatography system. The thermodynamic parameters(ΔH0, ΔS0) of those proteins were determined by means of Vant Hoff relationship(lnk-1/T). According to standard entropy change(ΔS0), the conformational change of the proteins was judged in the chromatographic process. The linear relationships between ΔH0 and ΔS0 can be used to evaluate "compensation temperature"(β) at the protein denaturation and identify the identity of the protein retention mechanism in weak cation-exchange chromatography.

  18. Metal Cations in G-Quadruplex Folding and Stability

    Science.gov (United States)

    Bhattacharyya, Debmalya; Mirihana Arachchilage, Gayan; Basu, Soumitra

    2016-09-01

    This review is focused on the structural and physico-chemical aspects of metal cation coordination to G-Quadruplexes (GQ) and their effects on GQ stability and conformation. G-Quadruplex structures are non-canonical secondary structures formed by both DNA and RNA. G-quadruplexes regulate a wide range of important biochemical processes. Besides the sequence requirements, the coordination of monovalent cations in the GQ is essential for its formation and determines the stability and polymorphism of GQ structures. The nature, location and dynamics of the cation coordination and their impact on the overall GQ stability are dependent on several factors such as the ionic radii, hydration energy and the bonding strength to the O6 of guanines. The intracellular monovalent cation concentration and the localized ion concentrations determine the formation of GQs and can potentially dictate their regulatory roles. A wide range of biochemical and biophysical studies on an array of GQ enabling sequences have generated at a minimum the knowledge base that allows us to often predict the stability of GQs in presence of the physiologically relevant metal ions, however, prediction of conformation of such GQs is still out of the realm.

  19. Structure and Reactivity of the Cysteine Methyl Ester Radical Cation

    NARCIS (Netherlands)

    Osburn, S.; Steill, J. D.; Oomens, J.; O' Hair, R. A. J.; Van Stipdonk, M.; Ryzhov, V.

    2011-01-01

    The structure and reactivity of the cysteine methyl ester radical cation, CysOMe(center dot+), have been examined in the gas phase using a combination of experiment and density functional theory (DFT) calculations. CysOMe(center dot+) undergoes rapid ion molecule reactions with dimethyl disulfide, a

  20. Cationic Organic/Inorganic Hybrids and Their Swelling Properties

    Institute of Scientific and Technical Information of China (English)

    E. S. Dragan; L. Ghimici; M. Cazacu

    2005-01-01

    @@ 1Introduction Specific properties of poly(dimethylsiloxanes), such as low glass transition temperature, low surface energy, good insulating properties, biological and chemical inertness, high diffusion coefficient of gases, make them very attractive for practical applications in the daily life. However, there is a great interest last time in the preparation of ionic organic/inorganic materials with new properties for new applications. Quaternary ammonium salt(QAS) groups included in siloxane copolymers could induce new interesting properties such as:permanent fungicidal and bactericidal properties, which make them very attractive as materials for sanitary applications, improved selectivity coefficients of the gas-separation membranes, ion-exchange properties and so forth. So far, QAS groups have been located in the side chain[1,2]. Our interest was focused on the preparation of some novel cationic polysiloxane copolymers containing QAS groups of both integral type and pendent type[3,4]. Our objectives for the present study concern the synthesis of some cationic organic/siloxane hybrid materials with swelling properties controlled by both the nature of cationic organic component and the ratio between the organic and inorganic counterparts. Such cationic hybrid materials could be of interest for the preparation of new stimuli-responsive hydrogels[5,6].

  1. Cation exchange interaction between antibiotic ciprofloxacin and montmorillonite

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Chih-Jen [Department of Earth Sciences, National Cheng Kung University, 1 University Road, Tainan 70101, Taiwan (China); Department of Geosciences, National Taiwan University, Taipei 10617, Taiwan (China); Li, Zhaohui, E-mail: li@uwp.edu [Department of Earth Sciences, National Cheng Kung University, 1 University Road, Tainan 70101, Taiwan (China); Department of Geosciences, University of Wisconsin - Parkside, Kenosha, WI 53144 (United States); Jiang, Wei-Teh, E-mail: atwtj@mail.ncku.edu.tw [Department of Earth Sciences, National Cheng Kung University, 1 University Road, Tainan 70101, Taiwan (China); Jean, Jiin-Shuh; Liu, Chia-Chuan [Department of Earth Sciences, National Cheng Kung University, 1 University Road, Tainan 70101, Taiwan (China)

    2010-11-15

    Exploring the interactions between antibiotics and soils/minerals is of great importance in resolving their fate, transport, and elimination in the environment due to their frequent detection in wastewater, river water, sewage sludge and soils. This study focused on determining the adsorption properties and mechanisms of interaction between antibiotic ciprofloxacin and montmorillonite (SAz-1), a swelling dioctahedral mineral with Ca{sup 2+} as the main interlayer cation. In acidic and neutral aqueous solutions, a stoichiometric exchange between ciprofloxacin and interlayer cations yielded an adsorption capacity as high as 330 mg/g, corresponding to 1.0 mmol/g. When solution pH was above its pK{sub a2} (8.7), adsorption of ciprofloxacin was greatly reduced due to the net repulsion between the negatively charged clay surfaces and the ciprofloxacin anion. The uptake of ciprofloxacin expanded the basal spacing (d{sub 001}) of montmorillonite from 15.04 to 17.23 A near its adsorption capacity, confirming cation exchange within the interlayers in addition to surface adsorption. Fourier transform infrared results further suggested that the protonated amine group of ciprofloxacin in its cationic form was electrostatically attracted to negatively charged sites of clay surfaces, and that the carboxylic acid group was hydrogen bonded to the basal oxygen atoms of the silicate layers. The results indicate that montmorillonite is an effective sorbent to remove ciprofloxacin from water.

  2. Cation exchange interaction between antibiotic ciprofloxacin and montmorillonite

    International Nuclear Information System (INIS)

    Exploring the interactions between antibiotics and soils/minerals is of great importance in resolving their fate, transport, and elimination in the environment due to their frequent detection in wastewater, river water, sewage sludge and soils. This study focused on determining the adsorption properties and mechanisms of interaction between antibiotic ciprofloxacin and montmorillonite (SAz-1), a swelling dioctahedral mineral with Ca2+ as the main interlayer cation. In acidic and neutral aqueous solutions, a stoichiometric exchange between ciprofloxacin and interlayer cations yielded an adsorption capacity as high as 330 mg/g, corresponding to 1.0 mmol/g. When solution pH was above its pKa2 (8.7), adsorption of ciprofloxacin was greatly reduced due to the net repulsion between the negatively charged clay surfaces and the ciprofloxacin anion. The uptake of ciprofloxacin expanded the basal spacing (d001) of montmorillonite from 15.04 to 17.23 A near its adsorption capacity, confirming cation exchange within the interlayers in addition to surface adsorption. Fourier transform infrared results further suggested that the protonated amine group of ciprofloxacin in its cationic form was electrostatically attracted to negatively charged sites of clay surfaces, and that the carboxylic acid group was hydrogen bonded to the basal oxygen atoms of the silicate layers. The results indicate that montmorillonite is an effective sorbent to remove ciprofloxacin from water.

  3. Fusion Pore Diameter Regulation by Cations Modulating Local Membrane Anisotropy

    Directory of Open Access Journals (Sweden)

    Doron Kabaso

    2012-01-01

    Full Text Available The fusion pore is an aqueous channel that is formed upon the fusion of the vesicle membrane with the plasma membrane. Once the pore is open, it may close again (transient fusion or widen completely (full fusion to permit vesicle cargo discharge. While repetitive transient fusion pore openings of the vesicle with the plasma membrane have been observed in the absence of stimulation, their frequency can be further increased using a cAMP-increasing agent that drives the opening of nonspecific cation channels. Our model hypothesis is that the openings and closings of the fusion pore are driven by changes in the local concentration of cations in the connected vesicle. The proposed mechanism of fusion pore dynamics is considered as follows: when the fusion pore is closed or is extremely narrow, the accumulation of cations in the vesicle (increased cation concentration likely leads to lipid demixing at the fusion pore. This process may affect local membrane anisotropy, which reduces the spontaneous curvature and thus leads to the opening of the fusion pore. Based on the theory of membrane elasticity, we used a continuum model to explain the rhythmic opening and closing of the fusion pore.

  4. Two different cationic positions in Cu-SSZ-13?

    Energy Technology Data Exchange (ETDEWEB)

    Kwak, Ja Hun; Zhu, Haiyang; Lee, Jong H.; Peden, Charles HF; Szanyi, Janos

    2012-04-18

    H2-TPR and FTIR were used to characterize the Cu ions present in Cu-SSZ-13 zeolite at different ion exchange levels. The results obtained are consistent with the presence of Cu ions in two distinct cationic positions of the SSZ-13 framework.

  5. Two different cationic positions in Cu-SSZ-13?

    Science.gov (United States)

    Hun Kwak, Ja; Zhu, Haiyang; Lee, Jong H; Peden, Charles H F; Szanyi, János

    2012-05-16

    H(2)-TPR and FTIR were used to characterize the nature of the Cu ions present in the Cu-SSZ-13 zeolite at different ion exchange levels. The results obtained are consistent with the presence of Cu ions at two distinct cationic positions in the SSZ-13 framework. PMID:22473309

  6. Metal Cations in G-Quadruplex Folding and Stability

    Science.gov (United States)

    Bhattacharyya, Debmalya; Mirihana Arachchilage, Gayan; Basu, Soumitra

    2016-01-01

    This review is focused on the structural and physicochemical aspects of metal cation coordination to G-Quadruplexes (GQ) and their effects on GQ stability and conformation. G-quadruplex structures are non-canonical secondary structures formed by both DNA and RNA. G-quadruplexes regulate a wide range of important biochemical processes. Besides the sequence requirements, the coordination of monovalent cations in the GQ is essential for its formation and determines the stability and polymorphism of GQ structures. The nature, location, and dynamics of the cation coordination and their impact on the overall GQ stability are dependent on several factors such as the ionic radii, hydration energy, and the bonding strength to the O6 of guanines. The intracellular monovalent cation concentration and the localized ion concentrations determine the formation of GQs and can potentially dictate their regulatory roles. A wide range of biochemical and biophysical studies on an array of GQ enabling sequences have generated at a minimum the knowledge base that allows us to often predict the stability of GQs in the presence of the physiologically relevant metal ions, however, prediction of conformation of such GQs is still out of the realm. PMID:27668212

  7. Copper cation removal in an electrokinetic cell containing zeolite.

    Science.gov (United States)

    Elsayed-Ali, Omar H; Abdel-Fattah, Tarek; Elsayed-Ali, Hani E

    2011-01-30

    Zeolites are used in environmental remediation of soil or water to immobilize or remove toxic materials by cation exchange. An experiment was conducted to test the use a low electric field to direct the toxic cations towards the zeolite. An electrokinetic cell was constructed using carbon electrodes. Synthetic Linde Type A (LTA) zeolite was placed in the cell. Copper(II) chloride dissolved in water was used as a contaminant. The Cu(2+) concentration was measured for ten hours with and without an applied electric field. The removal of the Cu(2+) ions was accelerated by the applied field in the first two hours. For longer time, the electric field did not improve the removal rate of the Cu(2+) ions. The presence of zeolite and applied electric field complicates the chemistry near the cathode and causes precipitation of Cu(2+) ions as copper oxide on the surface of the zeolite. With increased electric field the zeolite farther away from the cathode had little cation exchange due to the higher drift velocity of the Cu(2+) ions. The results also show that, in the LTA Zeolite A pellets, the cation exchange of Cu is limited to a shell of several tens of micrometers. PMID:21109348

  8. Peak metamorphic temperatures from cation diffusion zoning in garnet

    DEFF Research Database (Denmark)

    Smit, Matthijs Arjen; Scherer, Erik; Mezger, Klaus

    2013-01-01

    A model that relates the characteristic diffusion length and average cooling rate to peak temperature was developed for chemical diffusion in spherical geometries on the basis of geospeedometry principles and diffusion theory. The model is quantitatively evaluated for cation diffusion profiles in...

  9. Gene delivery by cationic lipid vectors : overcoming cellular barriers

    NARCIS (Netherlands)

    Zuhorn, Inge S; Engberts, Jan B F N; Hoekstra, Dirk

    2007-01-01

    Non-viral vectors such as cationic lipids are capable of delivering nucleic acids, including genes, siRNA or antisense RNA into cells, thus potentially resulting in their functional expression. These vectors are considered as an attractive alternative for virus-based delivery systems, which may suff

  10. Cr/nanodiamond composite plating with cobalt cation additive

    Institute of Scientific and Technical Information of China (English)

    Viet-Hue NGUYEN; Thi-Nam HOANG; Ngoc-Phong NGUYEN; Sik-Chol KWON; Man KIM; Joo-Yul LEE

    2009-01-01

    The effect of cationic additive on Cr/nanodiamond plating was studied. Chromium plating was performed in Sargent bath. Morphology of deposit was observed by scanning electron microscope(SEM); microhardness by hardness tester; wear rate by tribometer; amount of diamond in deposit by combustion method and passivity by potentiodynamic scan. Experimental results show that in the presence of cobalt cation, the amount of nanodiamond particle in the deposit is increased. With increasing diamond particle amount, the metallurgical, mechanical and electrochemical properties of Cr/nanodiamond deposit are improved. However, this improvement seems to be constrained. In the presence of 10 g/L of nanodiamond powder and 2.5 g/L of cobalt cation in the bath, the amount of diamond particle in deposit is increased by 4 times; and wear rate of Cr-Co/nanodiamond deposit is decreased by 2-3 times as compared with pure Cr/deposit. The passive current of Cr-Co/nanodiamond composite deposit is decreased from 18 to 8 ìA. The morphology of Cr/nanodiamond is smooth remarkably in the presence of cobalt cation.

  11. New cation-exchange membranes for hyperfiltration processes

    NARCIS (Netherlands)

    Velden, van der P.M.; Smolders, C.A.

    1977-01-01

    A new route for the preparation of cation exchange membranes from polystyrene-polyisoprene-polystyrene (SIS) block copolymers has been studied, using N-chlorosulfonyl isocyanate. At temperatures of 0° to 20°C, N-chlorosulfonyl isocyanate reacts readily with the olefin group in polyisoprenes, resulti

  12. Fibrin solubilizing properties of certain anionic and cationic detergents.

    Science.gov (United States)

    Chakrabarty, S

    1989-08-15

    The fibrinolytic (fibrin dissolving) properties of several anionic, cationic, nonionic and zwitterionic detergents were assessed in an in vitro fibrin agarose assay. Of the 4 anionic detergents tested, only sodium dodecyl sulfate (SDS) was found to be fibrinolytic. SDS was fibrinolytic either in the absence or presence of factor XIII. Four other cationic detergents were found to possess similar fibrinolytic properties. These cationic detergents were cetyltrimethylammonium bromide (CTAB), mix alkyltrimethyl ammonium bromide (MTAB), hexadecyltrimethylammonium bromide (HTAB) and cetylpyridium chloride (CPC). The nonionic (digitonin, triton X-100/tween 20) and zeitterionic (CHAPS, zeittergent 3-08) detergents were not fibrinolytic. Detergents mediated fibrinolysis, unlike that of tissue type plasminogen activator and urokinase, was independent of the presence of plasminogen. Non-detergents such as polyethylene glycol and highly charged compounds such as poly-1-lysine and poly-1-glutamic acid were not fibrinolytic. Fibrinolytic activity was observed for SDS and the cationic detergents at concentrations ranging from 0.1-10 percent. The effects of these fibrinolytic detergents (SDS, CTAB, MTAB, HTAB and CPC) on clot formation and on pre-formed clots were then assessed, using freshly drawn human venous blood. Incorporation of these detergents into blood inhibited the formation of clots in a concentration dependent manner. The detergents were also able to dissolve pre-formed clots in a similar fashion. SDS was found to be most potent in these properties. PMID:2510356

  13. Cationic polymers for nuclaic acid delivery to tumors

    NARCIS (Netherlands)

    Wolf, H.K. de

    2007-01-01

    In the field of cancer gene therapy, the use of gene carrier systems is considered indispensable. Cationic polymers are able to effectively condense plasmid DNA to nano-sized particles, further referred to as polyplexes. Compared to free DNA, polyplexes have shown improved nuclease-resistance, a mor

  14. Predictive model of cationic surfactant binding to humic substances

    NARCIS (Netherlands)

    Ishiguro, M.; Koopal, L.K.

    2011-01-01

    The humic substances (HS) have a high reactivity with other components in the natural environment. An important factor for the reactivity of HS is their negative charge. Cationic surfactants bind strongly to HS by electrostatic and specific interaction. Therefore, a surfactant binding model is devel

  15. Interactions between liposomes and cations in aqueous solution.

    Science.gov (United States)

    Ruso, Juan M; Besada, Lina; Martínez-Landeira, Pablo; Seoane, Laura; Prieto, Gerardo; Sarmiento, Félix

    2003-05-01

    An investigation on the dependence of electrophoretic mobilities of unilamellar vesicles of phosphatidylcholine-cholesterol-phosphatidylinositol (PC-Chol-PI) on the concentration of several cations with variations in the relation charge/radius in the range Na+, K+, Cs+, Mg2+, Ca2+, Ba2+, Al3+, and La3+ has been realized. Plots of zeta potential against ion concentration exhibit a maximum for all the cations under study, the position of the maximum is greatly affected by the charge of the ion. From the feature of these plots two phenomenon were observed: an initial binding of cations into the slipping plane for ion concentration below the maximum and a phenomenon of vesicle association for concentration above the maximum. To confirm these observations measurements on dynamic light scattering were performed to obtain the corresponding size distribution of the liposomes at different ion concentrations. Finally the ability of the Stern isotherm to describe the adsorption of the cations to vesicles was tested by two methods. The two main parameters of the theory: the total number of adsorption sites per unit area, N1, and the equilibrium constant, K; (and consequently the free energy of adsorption, deltaG0ads) were calculated for the different ions, showing good agreement. The equilibrium constants of adsorption have been found to obey a linear relationship with ion radius the slope of which decreases with the ion charge.

  16. Cold-inducible RNA-binding protein inhibits neuron apoptosis through the suppression of mitochondrial apoptosis.

    Science.gov (United States)

    Zhang, Hai-Tao; Xue, Jing-Hui; Zhang, Zhi-Wen; Kong, Hai-Bo; Liu, Ai-Jun; Li, Shou-Chun; Xu, Dong-Gang

    2015-10-01

    Cold-inducible RNA-binding protein (CIRP) is induced by mild hypothermia in several mammals, but the precise mechanism by which CIRP mediates hypothermia-induced neuroprotection remains unknown. We aimed to investigate the molecular mechanisms by which CIRP protects the nervous system during mild hypothermia. Rat cortical neurons were isolated and cultured in vitro under mild hypothermia (32°C). Apoptosis was measured by annexin V and propidium iodide staining, visualized by flow cytometry. Neuron ultrastructure was visualized by transmission electron microscopy. CIRP overexpression and knockdown were achieved via infection with pL/IRES/GFP-CIRP and pL/shRNA/F-CIRP-A lentivirus. RT(2) Profiler PCR Array Pathway Analysis and western blotting were used to evaluate the effects of CIRP overexpresion/knockdown on the neurons׳ transcriptome. Neuron late apoptosis was significantly reduced at day 7 of culture by 12h hypothermia, but neuron ultrastructure remained relatively intact. RT(2) Profiler PCR Array Pathway Analysis of 84 apoptosis pathway-associated factors revealed that mild hypothermia and CIRP overexpression induce similar gene expression profiles, specifically alterations of genes implicated in the mitochondrial apoptosis pathway. Mild hypothermia-treated neurons up-regulated 12 and down-regulated 38 apoptosis pathway-associated genes. CIRP-overexpressing neurons up-regulated 15 and down-regulated 46 genes. CIRP-knocked-down hypothermia-treated cells up-regulated 9 and down-regulated 40 genes. Similar results were obtained at the protein level. In conclusion, CIRP may inhibit neuron apoptosis through the suppression of the mitochondria apoptosis pathway during mild hypothermia.

  17. Photo-fragmentation spectroscopy of benzylium and 1-phenylethyl cations

    Energy Technology Data Exchange (ETDEWEB)

    Féraud, Géraldine; Dedonder-Lardeux, Claude; Jouvet, Christophe, E-mail: christophe.jouvet@univ-amu.fr [Physique des Interactions Ioniques et Moleculaires, UMR CNRS 7345, Aix-Marseille Université, Avenue Escadrille Normandie-Niémen, 13397 Marseille Cedex 20 (France); Soorkia, Satchin [Institut des Sciences Moléculaires d’Orsay, CNRS UMR 8214, Université Paris Sud 11, 91405 Orsay Cedex (France)

    2014-01-14

    The electronic spectra of cold benzylium (C{sub 6}H{sub 5}-CH{sub 2}{sup +}) and 1-phenylethyl (C{sub 6}H{sub 5}-CH-CH{sub 3}{sup +}) cations have been recorded via photofragment spectroscopy. Benzylium and 1-phenylethyl cations produced from electrosprayed benzylamine and phenylethylamine solutions, respectively, were stored in a cryogenically cooled quadrupole ion trap and photodissociated by an OPO laser, scanned in parts of the UV and visible regions (600–225 nm). The electronic states and active vibrational modes of the benzylium and 1-phenylethyl cations as well as those of their tropylium or methyl tropylium isomers have been calculated with ab initio methods for comparison with the spectra observed. Sharp vibrational progressions are observed in the visible region while the absorption features are much broader in the UV. The visible spectrum of the benzylium cation is similar to that obtained in an argon tagging experiment [V. Dryza, N. Chalyavi, J. A. Sanelli, and E. J. Bieske, J. Chem. Phys. 137, 204304 (2012)], with an additional splitting assigned to Fermi resonances. The visible spectrum of the 1-phenylethyl cation also shows vibrational progressions. For both cations, the second electronic transition is observed in the UV, around 33 000 cm{sup −1} (4.1 eV) and shows a broadened vibrational progression. In both cases the S{sub 2} optimized geometry is non-planar. The third electronic transition observed around 40 000 cm{sup −1} (5.0 eV) is even broader with no apparent vibrational structures, which is indicative of either a fast non-radiative process or a very large change in geometry between the excited and the ground states. The oscillator strengths calculated for tropylium and methyl tropylium are weak. Therefore, these isomeric structures are most likely not responsible for these absorption features. Finally, the fragmentation pattern changes in the second and third electronic states: C{sub 2}H{sub 2} loss becomes predominant at higher

  18. Autophagy and apoptosis: rivals or mates?

    Directory of Open Access Journals (Sweden)

    Yan Cheng

    2013-03-01

    Full Text Available Autophagy, a cellular process of "self-eating" by which intracellular components are degraded within the lysosome, is an evolutionarily conserved response to various stresses. Autophagy is associated with numerous patho-physiological conditions, and dysregulation of autophagy contributes to the pathogenesis of a variety of human diseases including cancer. Depending on context, activation of autophagy may promote either cell survival or death, two major events that determine pathological process of many illnesses. Importantly, the activity of autophagy is often associated with apoptosis, another critical cellular process determining cellular fate. A better understanding of biology of autophagy and its implication in human health and disorder, as well as the relationship between autophagy and apoptosis, has the potential of facilitating the development of autophagy-based therapeutic interventions for human diseases such as cancer.

  19. Autophagy and apoptosis: rivals or mates?

    Institute of Scientific and Technical Information of China (English)

    Yan Cheng; Jin-Ming Yang

    2013-01-01

    Autophagy,a cellular process of "self-eating" by which intracellular components are degraded within the lysosome,is an evolutionarily conserved response to various stresses.Autophagy is associated with numerous patho-physiological conditions,and dysregulation of autophagy contributes to the pathogenesis of a variety of human diseases including cancer.Depending on context,activation of autophagy may promote either cell survival or death,two major events that determine pathological process of many illnesses.Importantly,the activity of autophagy is often associated with apoptosis,another critical cellular process determining cellular fate.A better understanding of biology of autophagy and its implication in human health and disorder,as well as the relationship between autophagy and apoptosis,has the potential of facilitating the development of autophagy-based therapeutic interventions for human diseases such as cancer.

  20. Tumor necrosis factor-related apoptosis-inducing ligand-induced apoptosis in glioma U87 cells

    Institute of Scientific and Technical Information of China (English)

    Fei Zhong; Xiangyuan Wu; Chunkui Shao; Qu Lin; Min Dong; Jingyun Wen; Xiaokun Ma; Li Wei

    2010-01-01

    Studies have shown that tumor necrosis factor-related apoptosis-inducing ligand(TRAIL)exhibits strong induction of apoptosis in human glioma cells.It remains unclear whether the mitochondrion pathway,an important apoptosis signaling pathway,is involved in TRAIL-induced glioma cell apoptosis.In the present study,in vitro cultured human glioma U87 cells were treated with human recombinant soluble TRAIL.Apoptosis of glioma U87 cells,mitochondrial transmembrane potential(Δψm),cytoplasmic cytochrome c concentration and changes in caspase-3,-8 and-9 activity following human recombinant soluble TRAIL treatment were investigated to determine the mechanism of glioma U87 cell apoptosis induced by TRAIL.Additionally,blocking caspase-8resulted in TRAIL-induced mitochondrion pathway activation,suggesting that TRAIL,through activating caspase-8,initiated a series of mitochondrial events and resulted in apoptosis of glioma U87 cells.

  1. Reversibility of apoptosis in cancer cells

    OpenAIRE

    Tang, H. L.; Yuen, K L; Tang, H M; Fung, M C

    2008-01-01

    Apoptosis is a cell suicide programme characterised by unique cellular events such as mitochondrial fragmentation and dysfunction, nuclear condensation, cytoplasmic shrinkage and activation of apoptotic protease caspases, and these serve as the noticeable apoptotic markers for the commitment of cell demise. Here, we show that, however, the characterised apoptotic dying cancer cells can regain their normal morphology and proliferate after removal of apoptotic inducers. In addition, we demonstr...

  2. Poliovirus, pathogenesis of poliomyelitis, and apoptosis.

    OpenAIRE

    Blondel, B.; Colbère-Garapin, F.; Couderc, T.; Wirotius, A.; Guivel-Benhassine, F.

    2005-01-01

    Poliovirus (PV) is the causal agent of paralytic poliomyelitis, an acute disease of the central nervous system (CNS) resulting in flaccid paralysis. The development of new animal and cell models has allowed the key steps of the pathogenesis of poliomyelitis to be investigated at the molecular level. In particular, it has been shown that PV-induced apoptosis is an important component of the tissue injury in the CNS of infected mice, which leads to paralysis. In this review the molecular biolog...

  3. Cerulein Pancreatitis: Oxidative Stress, Inflammation, and Apoptosis

    OpenAIRE

    Kim, Hyeyoung

    2008-01-01

    Cerulein pancreatitis is similar to human edematous pancreatitis, manifesting with dysregulation of digestive enzyme production and cytoplasmic vacuolization, the death of acinar cells, edema formation, and infiltration of inflammatory cells into the pancreas. Reactive oxygen species are involved in nuclear factor-κB activation, cytokine expression, apoptosis and pathogenesis of pancreatitis. There is recent evidence that cerulein activates NADPH oxidase, which is a major source of reactive o...

  4. Honey and Apoptosis in Human Gastric Mucosa

    OpenAIRE

    Alireza Ostadrahimi; Jabiz Modaresi; Abdolrasoul Safaiyan; Mohammad H Somi; Aida Ghaffari

    2012-01-01

    Background: Gastric cancer is the fourth most common malignancy in the world. Honey is acomplex mixture of special biological active constituents. Honey possesses antioxidant and antitumorproperties. Nutritional studies have indicated that consumption of honey modulates therisk of developing gastric cancer. On the other hand, apoptosis has been reported to play a decisiverole in precancerous changes. Our chief study was conducted to assess the relationship betweenconsumption of honey and apop...

  5. Safrole oxide inhibits angiogenesis by inducing apoptosis.

    Science.gov (United States)

    Zhao, Jing; Miao, Junying; Zhao, Baoxiang; Zhang, Shangli; Yin, Deling

    2005-06-01

    Our previous studies indicate that 3, 4-(methylenedioxy)-1-(2', 3'-epoxypropyl)-benzene (safrole oxide), a newly synthesized compound, induces apoptosis in vascular endothelial cells (VECs) and A549 lung cancer cells. To our knowledge, the inhibition of angiogenesis by safrole oxide has not been reported yet. We report here that cultured rat aorta treated with safrole oxide exhibited a significant microvessel reduction as determined by counting the number of microvessels in a phase contrast microscope. There were more microvessels formed in the presence of A549 lung cancer cells in rat aorta model, while a dramatic inhibition of angiogenesis was obtained by adding 220-450 micromol l(-1) of safrole oxide to the growth medium (Psafrole oxide produced only some abortive endothelial cells but not microvessels. Furthermore, safrole oxide induced antiangiogenic effect in the chorioallantoic membranes (CAM) as a dose dependent manner. Eggs treated with 2-11 micromol 100 microl(-1) per egg of the safrole oxide for 48 h exhibited a significant reduction in blood vessel area of the CAM, a process likely mediated by apoptosis as demonstrated by DNA fragmentation. Our results suggest that safrole oxide has antiangiogenic activity and this effect might occur by induction of cellular apoptosis.

  6. Lipid Metabolism, Apoptosis and Cancer Therapy

    Directory of Open Access Journals (Sweden)

    Chunfa Huang

    2015-01-01

    Full Text Available Lipid metabolism is regulated by multiple signaling pathways, and generates a variety of bioactive lipid molecules. These bioactive lipid molecules known as signaling molecules, such as fatty acid, eicosanoids, diacylglycerol, phosphatidic acid, lysophophatidic acid, ceramide, sphingosine, sphingosine-1-phosphate, phosphatidylinositol-3 phosphate, and cholesterol, are involved in the activation or regulation of different signaling pathways. Lipid metabolism participates in the regulation of many cellular processes such as cell growth, proliferation, differentiation, survival, apoptosis, inflammation, motility, membrane homeostasis, chemotherapy response, and drug resistance. Bioactive lipid molecules promote apoptosis via the intrinsic pathway by modulating mitochondrial membrane permeability and activating different enzymes including caspases. In this review, we discuss recent data in the fields of lipid metabolism, lipid-mediated apoptosis, and cancer therapy. In conclusion, understanding the underlying molecular mechanism of lipid metabolism and the function of different lipid molecules could provide the basis for cancer cell death rationale, discover novel and potential targets, and develop new anticancer drugs for cancer therapy.

  7. Resveratrol induces apoptosis in pancreatic cancer cells

    Institute of Scientific and Technical Information of China (English)

    ZHOU Jia-hua; CHENG Hai-yan; YU Ze-qian; HE Dao-wei; PAN Zheng; YANG De-tong

    2011-01-01

    Background Pancreatic cancer is one of the most lethal human cancers with a very low survival rate of 5 years.Conventional cancer treatments including surgery, radiation, chemotherapy or combinations of these show little effect on this disease. Several proteins have been proved critical to the development and the progression of pancreatic cancer.The aim of this study was to investigate the effect of resveratrol on apoptosis in pancreatic cancer cells.Methods Several pancreatic cancer cell lines were screened by resveratrol, and its toxicity was tested by normal pancreatic cells. Western blotting was then performed to analyze the molecular mechanism of resveratrol induced apoptosis of pancreatic cancer cell lines.Results In the screened pancreatic cancer cell lines, capan-2 and colo357 showed high sensitivity to resveratrol induced apoptosis. Resveratrol exhibited insignificant toxicity to normal pancreatic cells. In resveratrol sensitive cells,capan-2 and colo357, the activation of caspase-3 was detected and showed significant caspase-3 activation upon resveratrol treatment; p53 and p21 were also detected up-regulated upon resveratrol treatment.Conclusion Resveratrol provides a promising anti-tumor stratagy to fight against pancreatic cancer.

  8. Lithium protects ethanol-induced neuronal apoptosis

    International Nuclear Information System (INIS)

    Lithium is widely used for the treatment of bipolar disorder. Recent studies have demonstrated its neuroprotective effect. Ethanol is a potent neurotoxin that is particularly harmful to the developing nervous system. In this study, we evaluated lithium's neuroprotection against ethanol-induced apoptosis. Transient exposure of infant mice to ethanol caused apoptotic cell death in brain, which was prevented significantly by administering a low dose of lithium 15 min later. In cultured cerebellar granule neurons, ethanol-induced apoptosis and activation of caspase-3/9, both of which were prevented by lithium. However, lithium's protection is not mediated by its commonly known inhibition of glycogen synthase3β, because neither ethanol nor lithium has significant effects on the phosphorylation of Akt (ser473) or GSK3β (ser9). In addition, the selective GSK-3β inhibitor SB-415286 was unable to prevent ethanol-induced apoptosis. These data suggest lithium may be used as a potential preventive measure for ethanol-induced neurological deficits

  9. Apoptosis de fibroblastos gingivales en periodontitis

    Directory of Open Access Journals (Sweden)

    Roger Mauricio Arce

    2007-09-01

    Full Text Available Introducción: Los fibroblastos gingivales humanos (FGH tienen un papel importante en la enfermedad periodontal, pues alteran su normal funcionamiento en respuesta a estímulos pro-inflamatorios. Se cree que los fibroblastos se pueden eliminar anormalmente por medio de apoptosis en periodontitis. El propósito de este estudio es determinar y cuantificar la apoptosis de FGH en biopsias del periodonto de individuos sanos y con enfermedad periodontal. Métodos: Se realizó un estudio clínico descriptivo de corte transversal en personas con diagnóstico de salud periodontal (S, gingivitis (G y periodontitis crónica (PC. Se tomaron biopsias escisionales y se hicieron tinciones inmunohistoquímicas (hematoxilina-eosina, caspasa-3 y vimentina. Las placas se interpretaron por histopatología y se digitalizaron para cuantificar las células apoptóticas. Todos los datos se analizaron con un software estadístico para encontrar diferencias significativas (p0.5, r²=0.02; mientras que para las células inflamatorias se encontró una relación proporcional significativa (p<0.05, r²=0.2018. Conclusiones: Los resultados permiten concluir que tanto los fibroblastos gingivales como las células inflamatorias presentan apoptosis manifiesta por la expresión de caspasa-3, y ésta se incrementa significativamente en gingivitis y enfermedad periodontal.

  10. Apoptosis signal-regulating kinase 1 mediates denbinobin-induced apoptosis in human lung adenocarcinoma cells

    Directory of Open Access Journals (Sweden)

    Pan Shiow-Lin

    2009-05-01

    Full Text Available Abstract In the present study, we explore the role of apoptosis signal-regulating kinase 1 (ASK1 in denbinobin-induced apoptosis in human lung adenocarcinoma (A549 cells. Denbinobin-induced cell apoptosis was attenuated by an ASK1 dominant-negative mutant (ASK1DN, two antioxidants (N-acetyl-L-cysteine (NAC and glutathione (GSH, a c-Jun N-terminal kinase (JNK inhibitor (SP600125, and an activator protein-1 (AP-1 inhibitor (curcumin. Treatment of A549 cells with denbinobin caused increases in ASK1 activity and reactive oxygen species (ROS production, and these effects were inhibited by NAC and GSH. Stimulation of A549 cells with denbinobin caused JNK activation; this effect was markedly inhibited by NAC, GSH, and ASK1DN. Denbinobin induced c-Jun phosphorylation, the formation of an AP-1-specific DNA-protein complex, and Bim expression. Bim knockdown using a bim short interfering RNA strategy also reduced denbinobin-induced A549 cell apoptosis. The denbinobin-mediated increases in c-Jun phosphorylation and Bim expression were inhibited by NAC, GSH, SP600125, ASK1DN, JNK1DN, and JNK2DN. These results suggest that denbinobin might activate ASK1 through ROS production to cause JNK/AP-1 activation, which in turn induces Bim expression, and ultimately results in A549 cell apoptosis.

  11. Embryo apoptosis identification: Oocyte grade or cleavage stage?

    Science.gov (United States)

    Bakri, Noraina Mohd; Ibrahim, Siti Fatimah; Osman, Nurul Atikah; Hasan, Nurhaslina; Jaffar, Farah Hanan Fathihah; Rahman, Zulaiha Abdul; Osman, Khairul

    2016-01-01

    Apoptosis is a programed cell death that is vital for tissue homeostasis. However, embryo apoptosis had been known to be related to embryo fragmentation which should be avoided in in vitro fertilization (IVF). The purpose of this study was to evaluate the relationship of embryo apoptosis with the grade of immature oocytes and cleavage stage of in vitro produced (IVP) cattle embryos. This study consisted of 345 oocytes collected through ovary slicing. Immature oocytes were graded as A, B and C. This grading was based on cumulus cell thickness and compactness. All oocytes then underwent an in vitro maturation (IVM) procedure. An IVF was done 24 h after IVM culture. Prior to staining, stage of cleaved embryos was determined and classified as either 2, 4, 8 or >8-cell embryo stage. Apoptosis status of cleaved IVP embryos was determined by using annexin V-FITC staining technique at 48 and 72 h post insemination (hpi). Apoptosis status for each embryo was classified as either early or late. The result showed that there was no significant difference (p > 0.05) of apoptosis status among grade A, B and C embryos. All grades of oocytes showed embryo apoptosis where 1.5% late apoptosis for grade A, 4.5% and 10.4% of early and late apoptosis for grade B and grade C. Early apoptosis was not seen in grade A embryo. We also noted no significant difference (p > 0.05) of apoptosis status between 2, 4, 8 and >8-cell embryo stage. Early apoptosis was also not seen in >8-cell stage. Even though there were no differences in apoptosis expression between the three classes, the cleavage rate of grade A oocytes was significantly higher (p quality and the cleavage stage of the embryo produced. PMID:26858565

  12. Intracoronary levosimendan during ischemia prevents myocardial apoptosis.

    Directory of Open Access Journals (Sweden)

    Markus eMalmberg

    2012-02-01

    Full Text Available Background. Levosimendan is a calcium-sensitizing inotropic agent that prevents myocardial contractile depression following cardiac surgery. Levosimendan has also anti-apoptotic properties, but the role of this mechanism is not clear. We studied whether levosimendan prevents cardiomyocyte apoptosis and post-operative stunning after either intracoronary administration or intravenous infusion in an experimental model. Methods. Pigs (n=24 were subjected to 40 minutes of global, cardioplegic ischemia under cardiopulmonary bypass and 240 minutes of reperfusion. L-IV group received intravenous infusion of levosimendan (65 μg/kg 40 minutes before ischemia and L-IC group received levosimendan (65 μg/kg during ischemia administered intracoronary. Control group was operated without levosimendan. Echocardiography was performed to all animals. Apoptosis was determined from transmyocardial biopsies taken from left ventricle using TUNEL assay and immunohistochemistry of active caspace-3. Results. Apoptosis was induced after ischemia-reperfusion in all groups (pre L-IV 0.002±0.004 % vs. post L-IV 0.020±0.017 % p=0.02, pre L-IC 0.001±0.004 % vs. post L-IC 0.020±0.017 % p<0.001, pre control 0.007±0.013 % vs. post control 0.062±0.044 % p=0.01. The amount of apoptosis was higher in the controls, compared with the L-IV (p=0.03 and the L-IC (p=0.03 groups. Longitudinal left ventricular contraction was significantly reduced in the L-IC and the control groups when compared to the L-IV group (L-IV 0.75±0.12 mm vs. L-IC 0.53±0.11 mm p=0.003, L-IV vs. control 0.54±0.11 p=0.01. Conclusions. Both intracoronary administration and pre-ischemic intravenous infusion of levosimendan equally prevented apoptosis, but intravenous administration was required for optimal preservation of the post-operative systolic left ventricle function.

  13. Spironolactone induces apoptosis in human mononuclear cells. Association between apoptosis and cytokine suppression

    DEFF Research Database (Denmark)

    Mikkelsen, Martin; Sønder, S U; Nersting, J;

    2006-01-01

    Spironolactone (SPIR) has been described to suppress accumulation of pro-inflammatory cytokines. Here, the suppression of TNF-alpha in lipopolysaccharide (LPS)-stimulated mononuclear cell cultures was confirmed. However, SPIR was also found to induce apoptosis, prompting the investigations...... of a possible association between the two effects: The apoptosis-inducing and the cytokine-suppressive effects of SPIR correlated with regard to the effective concentration range. Also, pre-incubation experiments demonstrated a temporal separation of the two effects of ... preceding apoptosis. An association between the two effects was also seen when testing several SPIR analogues. Contrary to TNF-alpha, the levels of IL-1beta increased in SPIR-treated cultures. However, the amount of IL-1beta in the supernatants depended upon the order of SPIR and LPS addition, as IL-1beta...

  14. Pharmacology of the human cell voltage-dependent cation channel. Part II: inactivation and blocking

    DEFF Research Database (Denmark)

    Bennekou, Poul; Barksmann, Trine L.; Kristensen, Berit I.;

    2004-01-01

    Human red cells; Nonselective voltage-dependent cation channel; NSVDC channel; Thiol group reagents......Human red cells; Nonselective voltage-dependent cation channel; NSVDC channel; Thiol group reagents...

  15. Enhancing microRNA transfection to inhibit survivin gene expression and induce apoptosis: could it be mediated by a novel combination of sonoporation and polyethylenimine?

    Institute of Scientific and Technical Information of China (English)

    CHEN Zhi-yi; LIANG Kun; QIURi-xiang; LUO Liang-ping

    2011-01-01

    Apoptosis is a physiologically essential mechanism of cell and plays an important role in reducing the development and progression of tumors.The appealing strategy for cancer therapy is to target the lesions that induce apoptosis in cancer colls.Survivin,the smallest member of the mammalian inhibitors of the apoptosis protein family,is upregulated in various malignancies to protect cells from apoptosis.Survivin knockdown could induco cancer cell apoptosis and inhibit tumor-angiogenesis.Survivin expression would be silenced by microRNA (miRNA)-mediated RNA interference.However,noninvasive and tissue-specific gene delivery techniques remain absent recently and the utilizations of miRNA expression vectors have been limited by inefficient delivery technique,especially in vivo.On the other hand,safe and promising technologies of gene transfection would be valuable in clinical gene therapy.Successful treatment of gene transfer method would lead to a new and readily available approach in the anticancer research.Sonoporation is an alternative technique of gene delivery that uses ultrasound targeted microbubble destruction to create pores in the cell membrane.Based on our previous studies,in this article,we postulated that the transfection of miRNA could be mediated by the combination of sonoporation and polyethylenimine (PEI) which was one of the most effective poly-cationic gene vectors and enhance the endocytosis of plasmids DNA and hypothesized that the gene silencing and apoptosis induction with miRNA targeting human Survivin would be improved by this novel technique.In our opinion,this novel combination of sonoporation and PEI could enhance targeted gene delivery effectively and might be a feasible,novel candidate for gene therapy.

  16. Star-like superalkali cations featuring planar pentacoordinate carbon.

    Science.gov (United States)

    Guo, Jin-Chang; Tian, Wen-Juan; Wang, Ying-Jin; Zhao, Xue-Feng; Wu, Yan-Bo; Zhai, Hua-Jin; Li, Si-Dian

    2016-06-28

    Superalkali cations, known to possess low vertical electron affinities (VEAs), high vertical detachment energies, and large highest occupied molecular orbital (HOMO)-lowest unoccupied molecular orbital (LUMO) energy gaps, are intriguing chemical species. Thermodynamically, such species need to be the global minima in order to serve as the promising targets for experimental realization. In this work, we propose the strategies of polyhalogenation and polyalkalination for designing the superalkali cations. By applying these strategies, the local-minimum planar pentacoordinate carbon (ppC) cluster CBe5 can be modified to form a series of star-like superalkali ppC or quasi-ppC CBe5X5 (+) (X = F, Cl, Br, Li, Na, K) cations containing a CBe5 moiety. Polyhalogenation and polyalkalination on the CBe5 unit may help eliminate the high reactivity of bare CBe5 molecule by covering the reactive Be atoms with noble halogen anions and alkali cations. Computational exploration of the potential energy surfaces reveals that the star-like ppC or quasi-ppC CBe5X5 (+) (X = F, Cl, Br, Li, Na, K) clusters are the true global minima of the systems. The predicted VEAs for CBe5X5 (+) range from 3.01 to 3.71 eV for X = F, Cl, Br and 2.12-2.51 eV for X = Li, Na, K, being below the lower bound of the atomic ionization potential of 3.89 eV in the periodic table. Large HOMO-LUMO energy gaps are also revealed for the species: 10.76-11.07 eV for X = F, Cl, Br and 4.99-6.91 eV for X = Li, Na, K. These designer clusters represent the first series of superalkali cations with a ppC center. Bonding analyses show five Be-X-Be three-center two-electron (3c-2e) σ bonds for the peripheral bonding, whereas the central C atom is associated with one 6c-2e π bond and three 6c-2e σ bonds, rendering (π and σ) double aromaticity. Born-Oppenheimer molecular dynamics simulations indicate that the CBe5 motif is robust in the clusters. As planar hypercoordination carbon species are often thermodynamically

  17. Star-like superalkali cations featuring planar pentacoordinate carbon

    Science.gov (United States)

    Guo, Jin-Chang; Tian, Wen-Juan; Wang, Ying-Jin; Zhao, Xue-Feng; Wu, Yan-Bo; Zhai, Hua-Jin; Li, Si-Dian

    2016-06-01

    Superalkali cations, known to possess low vertical electron affinities (VEAs), high vertical detachment energies, and large highest occupied molecular orbital (HOMO)-lowest unoccupied molecular orbital (LUMO) energy gaps, are intriguing chemical species. Thermodynamically, such species need to be the global minima in order to serve as the promising targets for experimental realization. In this work, we propose the strategies of polyhalogenation and polyalkalination for designing the superalkali cations. By applying these strategies, the local-minimum planar pentacoordinate carbon (ppC) cluster CBe5 can be modified to form a series of star-like superalkali ppC or quasi-ppC CBe5X5+ (X = F, Cl, Br, Li, Na, K) cations containing a CBe5 moiety. Polyhalogenation and polyalkalination on the CBe5 unit may help eliminate the high reactivity of bare CBe5 molecule by covering the reactive Be atoms with noble halogen anions and alkali cations. Computational exploration of the potential energy surfaces reveals that the star-like ppC or quasi-ppC CBe5X5+ (X = F, Cl, Br, Li, Na, K) clusters are the true global minima of the systems. The predicted VEAs for CBe5X5+ range from 3.01 to 3.71 eV for X = F, Cl, Br and 2.12-2.51 eV for X = Li, Na, K, being below the lower bound of the atomic ionization potential of 3.89 eV in the periodic table. Large HOMO-LUMO energy gaps are also revealed for the species: 10.76-11.07 eV for X = F, Cl, Br and 4.99-6.91 eV for X = Li, Na, K. These designer clusters represent the first series of superalkali cations with a ppC center. Bonding analyses show five Be-X-Be three-center two-electron (3c-2e) σ bonds for the peripheral bonding, whereas the central C atom is associated with one 6c-2e π bond and three 6c-2e σ bonds, rendering (π and σ) double aromaticity. Born-Oppenheimer molecular dynamics simulations indicate that the CBe5 motif is robust in the clusters. As planar hypercoordination carbon species are often thermodynamically unstable and

  18. Protein induced by vitamin K absence or antagonist-II production is a strong predictive marker for extrahepatic metastases in early hepatocellular carcinoma: a prospective evaluation

    International Nuclear Information System (INIS)

    Clinicians often experience extrahepatic metastases associated with hepatocellular carcinoma (HCC), even if no evidence of intrahepatic recurrence after treatment is observed. We investigated the pretreatment predictors of extrahepatic metastases in HCC patients. Patients diagnosed with HCC without evidence of extrahepatic metastases were prospectively enrolled. We evaluated the correlation between extrahepatic metastases and pretreatment clinical variables, including serum tumor markers. A total of 354 patients were included. Seventy-six patients (21%) had extrahepatic metastases during the observation period (median, 25.3 months; range, 0.6-51.3 months). Cox regression multivariate analysis showed that serum protein induced by vitamin K absence or antagonist-II (PIVKA-II) production levels, the intrahepatic tumor stage, platelet count, and portal vein thrombosis were independent risk factors for extrahepatic metastases. Patients with a PIVKA-II production ≥ 300 mAU/mL had a 2.7-fold (95% confidence interval; 1.5-4.8; P < 0.001) and 3.7-fold (95% confidence interval; 2.0-6.6; P < 0.001) increased risk for extrahepatic metastases after adjustment for stage, platelet count, alpha-fetoprotein ≥ 400 ng/mL, and portal vein thrombosis according to the AJCC and BCLC staging systems, respectively. PIVKA-II production levels might be a good candidate predictive marker for extrahepatic HCC metastases, especially in patients with smaller and/or fewer tumors in the liver with in stages regardless of serum alpha-fetoprotein

  19. Hepatoid carcinoma of the pancreas producing protein induced by vitamin K absence or antagonist II (PIVKA-II) and alpha-fetoprotein (AFP).

    Science.gov (United States)

    Matsueda, Kazuhiro; Yamamoto, Hiroshi; Yoshida, Yasuo; Notohara, Kenji

    2006-10-01

    We describe a rare case of hepatoid carcinoma of the pancreas with production of protein induced by vitamin K absence or antagonist II (PIVKA-II) and alpha-fetoprotein (AFP). The patient was a 49-year-old woman admitted because of high serum levels of PIVKA-II (1.63 AU/ml) and AFP (623 ng/ml) and abnormal ultrasonographic findings of the pancreas, found incidentally at medical checkup. Both ultrasonography and computed tomography showed swelling of the pancreas with small areas of low density, but no hepatic lesions. The serum levels of carcinoembryonic antigen and carbohydrate antigen 19-9 were not increased. A PIVKA-II and AFP-producing pancreatic cancer was strongly suspected, and total pancreatectomy was performed. Pathological examination showed that the tumor cells were arranged in trabecular and solid patterns with bile production, and were immunohistochemically positive for PIVKA-II and AFP, resembling hepatocellular carcinoma cells. The tumor was diagnosed as hepatoid carcinoma of the pancreas, and the patient has survived 48 months after initial diagnosis. It is important that hepatoid carcinoma be considered as a possible malignant tumor of the pancreas, and simultaneous measurement of the serum levels of AFP and PIVKA-II will enable earlier diagnosis. This is the first report describing hepatoid carcinoma of the pancreas producing PIVKA-II.

  20. Protein induced by vitamin K absence or antagonist-II production is a strong predictive marker for extrahepatic metastases in early hepatocellular carcinoma: a prospective evaluation

    Directory of Open Access Journals (Sweden)

    Yoon Jung-Hwan

    2011-10-01

    Full Text Available Abstract Background Clinicians often experience extrahepatic metastases associated with hepatocellular carcinoma (HCC, even if no evidence of intrahepatic recurrence after treatment is observed. We investigated the pretreatment predictors of extrahepatic metastases in HCC patients. Methods Patients diagnosed with HCC without evidence of extrahepatic metastases were prospectively enrolled. We evaluated the correlation between extrahepatic metastases and pretreatment clinical variables, including serum tumor markers. Results A total of 354 patients were included. Seventy-six patients (21% had extrahepatic metastases during the observation period (median, 25.3 months; range, 0.6-51.3 months. Cox regression multivariate analysis showed that serum protein induced by vitamin K absence or antagonist-II (PIVKA-II production levels, the intrahepatic tumor stage, platelet count, and portal vein thrombosis were independent risk factors for extrahepatic metastases. Patients with a PIVKA-II production ≥ 300 mAU/mL had a 2.7-fold (95% confidence interval; 1.5-4.8; P Conclusion PIVKA-II production levels might be a good candidate predictive marker for extrahepatic HCC metastases, especially in patients with smaller and/or fewer tumors in the liver with in stages regardless of serum alpha-fetoprotein.

  1. Prolonged Survival in a Case of Chemotherapy-Sensitive Gastric Cancer That Produced Alpha-Fetoprotein and Protein Induced by Vitamin K Antagonist-II

    Directory of Open Access Journals (Sweden)

    Naotaka Ogasawara

    2015-04-01

    Full Text Available The number of reported cases of alpha-fetoprotein (AFP-producing gastric cancer has gradually increased, with a reported prevalence of 1.3-1.5% of all gastric cancer cases. However, reports of gastric cancer accompanied by elevated serum levels of both AFP and protein induced by vitamin K antagonist-II (PIVKA-II are rare. The prognosis of AFP- and PIVKA-II-producing gastric cancer has been reported to be very poor because the tumor cells were considered to have a high malignant potential and the cancer progressed rapidly. We described a case of gastric cancer producing AFP and PIVKA-II in which chemotherapy was effective and resulted in prolonged survival, and these two tumor markers were useful for monitoring the treatment response. Routine health screening using upper abdominal ultrasonography revealed hepatic tumors in an apparently healthy 65-year-old man. Whole-body computed tomography (CT revealed multiple hepatic tumors, and an esophagogastroduodenoscopy (EGD revealed a Bormann type 3 tumor in the lower stomach. A biopsy specimen confirmed that the tumor was immunohistochemically positive for AFP, PIVKA-II, and human epidermal growth factor receptor 2. After chemotherapy, the gastric tumor appeared as a small elevated lesion on EGD, and CT revealed a remarkable reduction in the size of the metastatic liver tumors. The patient is still alive, 35 months after the initial chemotherapy.

  2. Prolonged Survival in a Case of Chemotherapy-Sensitive Gastric Cancer That Produced Alpha-Fetoprotein and Protein Induced by Vitamin K Antagonist-II.

    Science.gov (United States)

    Ogasawara, Naotaka; Takahashi, Emiko; Matsumoto, Tomoko; Amaike, Manami; Nohara, Mako; Nagao, Kazuhiro; Ebi, Masahide; Funaki, Yasushi; Sasaki, Makoto; Kasugai, Kunio

    2015-01-01

    The number of reported cases of alpha-fetoprotein (AFP)-producing gastric cancer has gradually increased, with a reported prevalence of 1.3-1.5% of all gastric cancer cases. However, reports of gastric cancer accompanied by elevated serum levels of both AFP and protein induced by vitamin K antagonist-II (PIVKA-II) are rare. The prognosis of AFP- and PIVKA-II-producing gastric cancer has been reported to be very poor because the tumor cells were considered to have a high malignant potential and the cancer progressed rapidly. We described a case of gastric cancer producing AFP and PIVKA-II in which chemotherapy was effective and resulted in prolonged survival, and these two tumor markers were useful for monitoring the treatment response. Routine health screening using upper abdominal ultrasonography revealed hepatic tumors in an apparently healthy 65-year-old man. Whole-body computed tomography (CT) revealed multiple hepatic tumors, and an esophagogastroduodenoscopy (EGD) revealed a Bormann type 3 tumor in the lower stomach. A biopsy specimen confirmed that the tumor was immunohistochemically positive for AFP, PIVKA-II, and human epidermal growth factor receptor 2. After chemotherapy, the gastric tumor appeared as a small elevated lesion on EGD, and CT revealed a remarkable reduction in the size of the metastatic liver tumors. The patient is still alive, 35 months after the initial chemotherapy. PMID:26034473

  3. Aspartame-induced apoptosis in PC12 cells.

    Science.gov (United States)

    Horio, Yukari; Sun, Yongkun; Liu, Chuang; Saito, Takeshi; Kurasaki, Masaaki

    2014-01-01

    Aspartame is an artificial sweetner added to many low-calorie foods. The safety of aspartame remains controversial even though there are many studies on its risks. In this study, to understand the physiological effects of trace amounts of artificial sweetners on cells, the effects of aspartame on apoptosis were investigated using a PC12 cell system. In addition, the mechanism of apoptosis induced by aspartame in PC12 cells and effects on apoptotic factors such as cytochrome c, apoptosis-inducing factor, and caspase family proteins were studied by Western blotting and RT-PCR. Aspartame-induced apoptosis in PC12 cells in a dose-dependent manner. In addition, aspartame exposure increased the expressions of caspases 8 and 9, and cytochrome c. These results indicate that aspartame induces apoptosis mainly via mitochondrial pathway involved in apoptosis due to oxigen toxicity.

  4. Regulation of apoptosis by the papillomavirus E6 oncogene

    Institute of Scientific and Technical Information of China (English)

    Ting-Ting Li; Li-Na Zhao; Zhi-Guo Liu; Ying Han; Dai-Ming Fan

    2005-01-01

    Infection with human papillomaviruses is strongly associated with the development of multiple cancers including esophageal squamous cell carcinoma. The HPV E6 gene is essential for the oncogenic potential of HPV.The recgulation of apoptosis by oncogene has been relatel to carcinogenesis closely; therefore, the modulation of E6 on cellular apoptosis has become a hot research topic recently. Inactivation of the pro-apoptotic tumor suppressor p53 by E6 is an important mechanism by which E6promotes cell growth; it is expected that inactivation of p53 by E6 should lead to a reduction in cellular apoptosis,numerous studies showed that E6 could in fact sensitize cells to apoptosis. The molecular basis for apoptosis modulation by E6 is poorly understood. In this article, we will present an overview of observations and current understanding of molecular basis for E6-induced apoptosis.

  5. Artesunate induces AIF-dependent apoptosis in A549 cells

    Science.gov (United States)

    Zhou, Chen-juan; Chen, Tong-Sheng

    2012-03-01

    Artesunate (ART), a semi-synthetic derivative of the sesquiterpene artemisinin extracted from the Chinese herb Artemisia annua, exerts a broad spectrum of clinical activity against human cancers. It has been shown that ART induces cancer cells death through apoptosis pathway. This study investigated whether ART treatment induced reactive oxygen species (ROS)-dependent cell death in the apoptosis fashion in human lung adenocarconoma A549 cell line and the proapoptotic protein apoptosis inducing factor (AIF) is involved in ART-induced apoptosis. Cells treated with ART exhibited typical apoptotic morphology as chromatin condensation, margination and shrunken nucleus. ART treatment also induced a loss of mitochondrial membrane potential and AIF release from mitochondria. Silencing AIF can remarkable attenuated ART-induced apoptosis. Collectively, ART induces apoptosis by caspase-independent intrinsic pathway in A549 cells.

  6. The Influence of Cationization on the Dyeing Performance of Cotton Fabrics with Direct Dyes

    Directory of Open Access Journals (Sweden)

    M. F. Shahin

    2015-08-01

    Full Text Available The effect of cationic modification of cotton fabrics, using cationic agent (Chromatech 9414 on direct dyeing characteristics was studied in this work. Cationization of cotton fabric at different conditions (pH, cationic agent concentration, temperature and time was investigated and the optimum conditions were determined . Nitrogen content of cotton samples pretreated with cationic agent was indicated. The results showed that increasing cationic agent concentration lead to higher nitrogen content on cotton fabric . The cationized cotton fabrics were dyed with two direct dyes (C.I. Direct Yellow 142 - C.I. Direct red 224 and the results were compared to untreated cotton fabrics. The parameters which may affect the dyeing process such as dye concn., addition of salt, time and temperature of dyeing were studied. The dyeing results illustrate that cationization improves the fabric dyeability compared to the uncationized cotton and the magnitude of increase in colour depth depends on the nitrogen content of the cationized cotton fabric .The results also refer to possibility of dyeing cationized cotton fabric with direct dyes without addition of electrolytes to give colour strength higher than that achieved on uncationized cotton using conventional dyeing method .Another important advantage of cationic treatment is in the saving of dye concn., energy ,dyeing time , rinse water and subsequently saving of waste water treatment , and finally minimizes the environmental pollution . The changes in surface morphology of fibres after cationization were identified by various methods such as wettability and scanning with the electron microscope. Different fastness properties were evaluated.

  7. Gene vectors based on DOEPC/DOPE mixed cationic liposomes : a physicochemical study

    NARCIS (Netherlands)

    Munoz-Ubeda, Monica; Rodriguez-Pulido, Alberto; Nogales, Aurora; Llorca, Oscar; Quesada-Perez, Manuel; Martin-Molina, Alberto; Aicart, Emilio; Junquera, Elena

    2011-01-01

    A double approach, experimental and theoretical, has been followed to characterize from a physicochemical standpoint the compaction process of DNA by means of cationic colloidal aggregates. The colloidal vectors are cationic liposomes constituted by a mixture of a novel cationic lipid, 1,2-dioleoyl-

  8. Structure of heavy cation molecules: from experiment to simulation

    Energy Technology Data Exchange (ETDEWEB)

    Den Auwer, C.; Fillaux, C.; Guilbaud, P.; Guillaumont, D.; Moisy, P. [CEA Marcoule DEN/DRCP/SCPS, 30207 Bagnols sur Ceze (France); Conradson, S.D. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Di Giandomenico, V.; Le Naour, C.; Simoni, E. [IPN Orsay, 91405 Orsay (France); Hennig, C. [Forschungszentrum Rossendorf, ROBL at ESRF, 38043 Grenoble (France)

    2008-07-01

    For industrial, environmental and public health purposes, actinide chemistry has been the subject of considerable efforts since the 50's. Aqueous redox chemistry, ionic selective recognition, uptake by specific biomolecules or compartments of the geosphere are some of the major fields of investigation. The physical-chemical properties of the actinide elements strongly depend on the 5f/6d electronic configuration. X-ray photons are an ideal spectroscopic tool for structure and bonding in actinide molecules. At high photon energies, actinide Extended X-ray Absorption Fine Structure (EXAFS) is a structural probe of the cation coordination sphere. Furthermore, coupling EXAFS with molecular dynamics or quantum chemical calculations leads to a better description of the 'cation in its close environment', like polyhedron, disorder, solvent effects etc.. (authors)

  9. Characterisation of heavy cations from dysprosium to plutonium

    International Nuclear Information System (INIS)

    For industrial, environmental and public health purposes, actinide chemistry has been the subject of considerable efforts since the 50's. Aqueous redox chemistry, ionic selective recognition, uptake by specific biomolecules or compartments of the geosphere are some of the major fields of investigation. The physical-chemical properties of the actinide and lanthanide elements strongly depend on the frontier orbital electronic configuration. This paper is divided in two parts. In the first one, coupling XAS with molecular dynamics allows to take into account solvent and disorder effects while fitting the EXAFS data of aqueous uranyl and dysprosium cations. In the second one EXAFS structural parameters of oxo-cations from protactinium to plutonium are compared to quantum chemical calculations. (authors)

  10. Two cationic peroxidases from cell walls of Araucaria araucana seeds.

    Science.gov (United States)

    Riquelme, A; Cardemil, L

    1995-05-01

    We have previously reported the purification and partial characterization of two cationic peroxidases from the cell walls of seeds and seedlings of the South American conifer, Araucaria araucana. In this work, we have studied the amino acid composition and NH2-terminal sequences of both enzymes. We also compare the data obtained from these analyses with those reported for other plant peroxidases. The two peroxidases are similar in their amino acid compositions. Both are particularly rich in glycine, which comprises more than 30% of the amino acid residues. The content of serine is also high, ca 17%. The two enzymes are different in their content of arginine, alanine, valine, phenylalanine and threonine. Both peroxidases have identical NH2-terminal sequences, indicating that the two proteins are genetically related and probably are isoforms of the same kind of peroxidase. The amino acid composition and NH2-terminal sequence analyses showed marked differences from the cationic peroxidases from turnip and horseradish. PMID:7786490

  11. Cation conductivity monitoring in cycling plants. A new approach

    Energy Technology Data Exchange (ETDEWEB)

    Turner, Randy C. [Swan Analytical USA, Wheeling, IL (United States)

    2012-09-15

    Due to substantial fuel costs, environmental issues, and economic impact, there has been increased pressure in recent years to reduce start-up times for all units, particularly combined cycle units. Any shortening of the time between start-up and reaching full load is of paramount importance. Cation conductivity is still the decisive measurement for the start-up of the steam turbine and the focus is now on how fast the cation conductivity results are available and how reliable they are. The time necessary to obtain correct and representative analysis values is greatly influenced by the design of the sampling and monitoring system. Employing various measures for the optimization of continuous monitoring equipment and employing optimally designed analyzers can reduce the response time of the instrumentation by more than half, thus providing significant economic rewards. The costs of the improvements are negligible compared to the benefits of reducing the time operating in bypass mode.

  12. Microstructure characterization and cation distribution of nanocrystalline cobalt ferrite

    Energy Technology Data Exchange (ETDEWEB)

    Abbas, Y.M., E-mail: ymabbas@live.com [Suez Canal University, Faculty of Science, Physics Department, Ismailia (Egypt); Mansour, S.A.; Ibrahim, M.H. [Suez Canal University, Faculty of Science, Physics Department, Ismailia (Egypt); Ali, Shehab E., E-mail: shehab_physics@yahoo.com [Suez Canal University, Faculty of Science, Physics Department, Ismailia (Egypt)

    2011-11-15

    Nanocrystalline cobalt ferrite has been synthesized using two different methods: ceramic and co-precipitation techniques. The nanocrystalline ferrite phase has been formed after 3 h of sintering at 1000 deg. C. The structural and microstructural evolutions of the nanophase have been studied using X-ray powder diffraction and the Rietveld method. The refinement result showed that the type of the cationic distribution over the tetrahedral and octahedral sites in the nanocrystalline lattice is partially an inverse spinel. The transmission electronic microscope analysis confirmed the X-ray results. The magnetic properties of the samples were characterized using a vibrating sample magnetometer. - Highlights: > The refinement result showed that the cationic distribution over the sites in the lattice is partially an inverse spinel. > The transmission electronic microscope analysis confirmed the X-ray results. > The magnetic properties of the samples were characterized using a vibrating sample magnetometer.

  13. Aggregation behavior of quaternary salt based cationic surfactants

    International Nuclear Information System (INIS)

    The aggregation behavior of pure cationic surfactants (quaternary salts) in water has been studied by electrical conductivity (at 293.15-333.15K), surface tension, dye solubilization and viscosity measurements (at 303.15K). Critical micelle concentrations (CMCs), degree of counter ion dissociation (β), aggregation number and sphere-to-rod transition for cationic surfactants are reported. Using law of mass action model, the thermodynamic parameters, viz. Gibbs energy (ΔGm-bar ), enthalpy (ΔHm-bar ) and entropy (ΔSm-bar ) were evaluated. The plots of differential conductivity (dk/dc)T,P, versus the total surfactant concentration enables us to determine the CMC values more precisely than the conventional method. Surfactants with longer hydrocarbon chain are adapted to rodlike micelle better than to a spherical micelle. The data are explained in terms of molecular characteristics of surfactants viz. nonpolar chain length, polar head group size and counter ion

  14. Structure of ionic liquids with cationic silicon-substitutions

    Science.gov (United States)

    Wu, Boning; Shirota, Hideaki; Lall-Ramnarine, Sharon; Castner, Edward W.

    2016-09-01

    Significantly lower viscosities result when a single alkyl carbon is replaced by a silicon atom on the side chain of an ionic liquid cation. To further explore this effect, we compare liquid structure factors measured using high-energy X-ray scattering and calculated using molecular dynamics simulations. Four ionic liquids are studied that each has a common anion, bis(trifluoromethylsulfonyl)amide ( NTf2 - ). The four cations for this series of NTf2 - -anion ionic liquids are 1-methyl-3-trimethylsilylmethylimidazolium (Si-mim+), 1-methyl-3-neopentylimidazolium (C-mim+), 1-methyl-3-pentamethyldisiloxymethylimidazolium (SiOSi-mim+), and 1-methyl-1-trimethylsilylmethylpyrrolidinium (Si-pyrr+). To achieve quantitative agreement between the structure factors measured using high-energy X-ray scattering and molecular dynamics simulations, new transferable parameters for silicon were calibrated and added to the existing force fields.

  15. Mobility of alkali cations in polypyrrole-dodecyl sulfate

    Energy Technology Data Exchange (ETDEWEB)

    Kupila, E.L. [Department of Chemistry, University of Turku, 20500 Turku (Finland); Kankare, J. [Department of Chemistry, University of Turku, 20500 Turku (Finland)

    1995-03-01

    Due to the immobility of the large dodecyl sulfate anion, the mobile ions in polypyrrole-dodecyl sulfate are small ions from the solution. Virgin PP-dodecyl sulfate does not contain other ionic species, but already the first reduction causes the incorporation of cations into the membrane. Using in situ AC conductimetry on a double-band platinum electrode, we show that the insertion of cations from the solution into the PP membrane proceeds as a non-conducting zone advancing from the solution interface toward the substrate. The model allows to estimate ion mobilities in the membrane giving 8.6x10{sup -7}cm{sup 2}s{sup -1}V{sup -1} for K{sup +}. (orig.)

  16. Removal of both cationic and anionic contaminants by amphoteric starch.

    Science.gov (United States)

    Peng, Huanlong; Zhong, Songxiong; Lin, Qintie; Yao, Xiaosheng; Liang, Zhuoying; Yang, Muqun; Yin, Guangcai; Liu, Qianjun; He, Hongfei

    2016-03-15

    A novel amphoteric starch incorporating quaternary ammonium and phosphate groups was applied to investigate the efficiency and mechanism of cationic and anionic contaminant treatment. Its flocculation abilities for kaolin suspension and copper-containing wastewater were evaluated by turbidity reduction and copper removal efficiency, respectively. And the kinetics of formation, breakage and subsequent re-formation of aggregates were monitored using a Photometric Dispersion Analyzer (PDA) and characterized by flocculation index (FI). The results showed that amphoteric starch possessed the advantages of being lower-dosages-consuming and being stronger in shear resistance than cationic starch, and exhibited a good flocculation efficiency over a wide pH range from 3.0 to 11.0. PMID:26794754

  17. Sulfonated polyvinyl chloride fibers for cation-exchange microextraction.

    Science.gov (United States)

    Xu, Li; Lee, Hian Kee

    2009-09-18

    Polyvinyl chloride (PVC) fiber was derivatized by concentrated sulfuric acid to yield sulfonated PVC (PVC-SO3H). The PVC-SO3H fiber had dual properties as a sorbent, based on cation-exchange and hydrophobicity. In the present study, the novel fiber was used directly as an individual device for extraction purposes in the cation-exchange microextraction of anaesthetics, followed by high-performance liquid chromatography-UV analysis. The results demonstrated that this PVC-SO3H fiber-based microextraction afforded convenient operation and cost-effective application to basic analytes. The limits of detection for four anaesthetics ranged from 1.2 to 6.0 ng/mL. No carryover (because of its disposable usage), and no loss of sorbent phase (which normally occurs in stir-bar sorptive extraction) during extraction were observed.

  18. Structure, spectra and dynamics of alkali cation microhydration clusters

    OpenAIRE

    Schulz, Franziska

    2005-01-01

    The main focus of this work was the theoretical investigation of alkali cation microhydration clusters with sodium, potassium, and caesium as central ion and up to 24 water molecules per cluster. Structures were obtained applying global geometry optimisation, using a specialised version of genetic algorithms and the common TIP4P/OPLS model potential. The global and most important local minimum energy structures have been investigated and the results obtained constitute a first complete and sy...

  19. Identification of bilinear systems using differential evolution algorithm

    Indian Academy of Sciences (India)

    Saban Ozer; Hasan Zorlu

    2011-06-01

    In this work, a novel identification method based on differential evolution algorithm has been applied to bilinear systems and its performance has been compared to that of genetic algorithm. Box–Jenkins system and different type bilinear systems have been identified using differential evolution and genetic algorithms. The simulation results have shown that bilinear systems can be successfully and efficiently identified using these algorithms.

  20. THE CHARACTERISTICS OF HIGH MOLECULAR WEIGHT CATIONIC POLYACRYLAMIDE

    Institute of Scientific and Technical Information of China (English)

    Hongjie Zhang; Huiren Hu; Fushan Chen

    2004-01-01

    In this paper, the cationic polyacrylamide (CPAM)with high molecular weight was prepared in aqueous solution through a complex initiator system. The CPAM was characterized by Fourier transform infrared spectroscopy (FTIR) and 13C nuclear magnetic resonance spectroscopy (13C NMR), and the charge density of the CPAM was determined by colloid titration. The results obtained indicated that the copolymerization technology used in the experiment was successful.

  1. Collectins and Cationic Antimicrobial Peptides of the Respiratory Epithelia

    OpenAIRE

    Grubor, B.; Meyerholz, D. K.; Ackermann, M R

    2006-01-01

    The respiratory epithelium is a primary site for the deposition of microorganisms that are acquired during inspiration. The innate immune system of the respiratory tract eliminates many of these potentially harmful agents preventing their colonization. Collectins and cationic antimicrobial peptides are antimicrobial components of the pulmonary innate immune system produced by respiratory epithelia, which have integral roles in host defense and inflammation in the lung. Synthesis and secretion...

  2. Natural zeolite reactivity towards ozone: The role of compensating cations

    International Nuclear Information System (INIS)

    Highlights: ► Chemical and thermal treatment enhances catalytic activity of natural zeolite. ► Modified natural zeolite exhibits high stability after thermal treatment. ► Reducing the compensating cation content leads to an increase on ozone abatement. ► Surface active atomic oxygen was detected using the DRIFT technique. ► The highest reactivity toward ozone was performed by NH4Z3 zeolite sample. - Abstract: Among indoor pollutants, ozone is recognised to pose a threat to human health. Recently, low cost natural zeolites have been applied as alternative materials for ozone abatement. In this work, the effect of compensating cation content of natural zeolite on ozone removal is studied. A Chilean natural zeolite is used here as starting material. The amount of compensating cations in the zeolite framework was modified by ion exchange using an ammonium sulphate solution (0.1 mol L−1). Characterisation of natural and modified zeolites were performed by X-ray powder diffraction (XRD), nitrogen adsorption at 77 K, elemental analysis, X-ray fluorescence (XRF), thermogravimetric analysis coupled with mass spectroscopy (TGA-MS), and temperature-programmed desorption of ammonia (NH3-TPD). Ozone adsorption and/or decomposition on natural and modified zeolites were studied by diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). Results show that the zeolite compensating cation content affects ozone interaction with zeolite active sites. Ammonium ion-exchange treatments followed by thermal out-gassing at 823 K, reduces ozone diffusion resistance inside the zeolite framework, increasing ozone abatement on zeolite surface active sites. Weak and strong Lewis acid sites of zeolite surface are identified here as the main active sites responsible of ozone removal.

  3. Natural zeolite reactivity towards ozone: The role of compensating cations

    Energy Technology Data Exchange (ETDEWEB)

    Valdes, Hector, E-mail: hvaldes@ucsc.cl [Laboratorio de Tecnologias Limpias (F. Ingenieria), Universidad Catolica de la Santisima Concepcion, Alonso de Ribera 2850, Concepcion (Chile); Alejandro, Serguei; Zaror, Claudio A. [Departamento de Ingenieria Quimica (F. Ingenieria), Universidad de Concepcion, Concepcion (Chile)

    2012-08-15

    Highlights: Black-Right-Pointing-Pointer Chemical and thermal treatment enhances catalytic activity of natural zeolite. Black-Right-Pointing-Pointer Modified natural zeolite exhibits high stability after thermal treatment. Black-Right-Pointing-Pointer Reducing the compensating cation content leads to an increase on ozone abatement. Black-Right-Pointing-Pointer Surface active atomic oxygen was detected using the DRIFT technique. Black-Right-Pointing-Pointer The highest reactivity toward ozone was performed by NH4Z3 zeolite sample. - Abstract: Among indoor pollutants, ozone is recognised to pose a threat to human health. Recently, low cost natural zeolites have been applied as alternative materials for ozone abatement. In this work, the effect of compensating cation content of natural zeolite on ozone removal is studied. A Chilean natural zeolite is used here as starting material. The amount of compensating cations in the zeolite framework was modified by ion exchange using an ammonium sulphate solution (0.1 mol L{sup -1}). Characterisation of natural and modified zeolites were performed by X-ray powder diffraction (XRD), nitrogen adsorption at 77 K, elemental analysis, X-ray fluorescence (XRF), thermogravimetric analysis coupled with mass spectroscopy (TGA-MS), and temperature-programmed desorption of ammonia (NH{sub 3}-TPD). Ozone adsorption and/or decomposition on natural and modified zeolites were studied by diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). Results show that the zeolite compensating cation content affects ozone interaction with zeolite active sites. Ammonium ion-exchange treatments followed by thermal out-gassing at 823 K, reduces ozone diffusion resistance inside the zeolite framework, increasing ozone abatement on zeolite surface active sites. Weak and strong Lewis acid sites of zeolite surface are identified here as the main active sites responsible of ozone removal.

  4. Proton and sodium cation affinities of harpagide: a computational study.

    Science.gov (United States)

    Colas, Cyril; Bouchonnet, Stéphane; Rogalewicz-Gilard, Françoise; Popot, Marie-Agnès; Ohanessian, Gilles

    2006-06-15

    The aim of this work was to estimate the proton and sodium cation affinities of harpagide (Har), an iridoid glycoside responsible for the antiinflammatory properties of the medicinal plant Harpagophytum. Monte Carlo conformational searches were performed at the semiempirical AM1 level to determine the most stable conformers for harpagide and its protonated and Na+-cationized forms. The 10 oxygen atoms of the molecule were considered as possible protonation and cationization sites. Geometry optimizations were then refined at the DFT B3LYP/6-31G level from the geometries of the most stable conformers found. Final energetics were obtained at the B3LYP/6-311+G(2d,2p)//B3LYP/6-31G level. The proton and sodium ion affinities of harpagide have been estimated at 223.5 and 66.0 kcal/mol, respectively. Since harpagide mainly provides HarNa+ ions in electrospray experiments, the DeltarG298 associated with the reaction of proton/sodium exchange between Har and methanol, MeOHNa+ + HarH+ --> MeOH2+ + HarNa+ (1), has been calculated; it has been estimated to be 1.9 kcal/mol. Complexing a methanol molecule to each reagent and product of reaction 1 makes the reaction become exothermic by 1.7 kcal/mol. These values are in the limit of the accuracy of the method and do not allow us to conclude definitely whether the reaction is endo- or exothermic, but, according to these very small values, the cation exchange reaction is expected to proceed easily in the final stages of the ion desolvation process. PMID:16759142

  5. Effect of cationic polyelectrolytes addition in cement cohesion

    OpenAIRE

    Edison Albert Zuluaga-Hernández; Bibian A Hoyos

    2014-01-01

    Here is studied the variation in cohesion of cement main phase (C-S-H) as a result of cationic polyelectrolytes addition (quaternary amines spermine and norspermidine). Cohesion study was carried out by molecular simulation techniques (Monte Carlo) using a primitive model in a canonical ensemble (NVT). The proposed model takes into account the influence of ionic size of each particle and the addition of polyelectrolytes with different charge number and separation. The results obtained show th...

  6. Interactions of microfibrillated cellulose and cellulosic fines with cationic polyelectrolytes

    OpenAIRE

    Taipale, Tero

    2010-01-01

    The overall aim of this work was to produce and characterize different types of cellulosic fines and microfibrillated cellulose; to study their interactions with high molar mass cationic polyelectrolytes; and to demonstrate novel examples of their utilization. The work was performed, and its results discussed mainly from papermaking point of view, but the results are also well applicable in other fields of industry. Cellulosic fines are an essential component of papermaking fiber suspens...

  7. DNA Methylation and Apoptosis Resistance in Cancer Cells

    OpenAIRE

    Pierre-François Cartron; François Marie Vallette; Eric Hervouet; Mathilde Cheray

    2013-01-01

    Apoptosis is a cell death programme primordial to cellular homeostasis efficiency. This normal cell suicide program is the result of the activation of a cascade of events in response to death stimuli. Apoptosis occurs in normal cells to maintain a balance between cell proliferation and cell death. A deregulation of this balance due to modifications in the apoptosic pathway leads to different human diseases including cancers. Apoptosis resistance is one of the most important hallmarks of cance...

  8. Epithelial Cell Apoptosis Causes Acute Lung Injury Masquerading as Emphysema

    OpenAIRE

    Mouded, Majd; Egea, Eduardo E.; Brown, Matthew J.; Hanlon, Shane M.; Houghton, A. McGarry; Tsai, Larry W; Ingenito, Edward P.; Shapiro, Steven D

    2009-01-01

    Theories of emphysema traditionally revolved around proteolytic destruction of extracellular matrix. Models have recently been developed that show airspace enlargement with the induction of pulmonary cell apoptosis. The purpose of this study was to determine the mechanism by which a model of epithelial cell apoptosis caused airspace enlargement. Mice were treated with either intratracheal microcystin (MC) to induce apoptosis, intratracheal porcine pancreatic elastase (PPE), or their respectiv...

  9. Embryo apoptosis identification: Oocyte grade or cleavage stage?

    OpenAIRE

    Bakri, Noraina Mohd; Ibrahim, Siti Fatimah; Osman, Nurul Atikah; Hasan, Nurhaslina; Jaffar, Farah Hanan Fathihah; Rahman, Zulaiha Abdul; Osman, Khairul

    2015-01-01

    Apoptosis is a programed cell death that is vital for tissue homeostasis. However, embryo apoptosis had been known to be related to embryo fragmentation which should be avoided in in vitro fertilization (IVF). The purpose of this study was to evaluate the relationship of embryo apoptosis with the grade of immature oocytes and cleavage stage of in vitro produced (IVP) cattle embryos. This study consisted of 345 oocytes collected through ovary slicing. Immature oocytes were graded as A, B and C...

  10. Epithelial apoptosis: cause or consequence of ulcerative colitis?

    DEFF Research Database (Denmark)

    Seidelin, Jakob Benedict; Nielsen, Ole Haagen

    2009-01-01

    were cultured. Apoptosis was determined by flow cytometry. Cells were stimulated with Fas ligand. The disease was characterized by endoscopic findings, microscopic inflammation grade, surrogate markers of disease activity (hemoglobin level, white blood cell count, C-reactive protein, or albumin......), and the clinical course 6 months after biopsy. RESULTS: Epithelial apoptosis correlated with local inflammation, both macroscopic (psurrogate markers of disease activity did not correlate with apoptosis rate. However, increased microscopic...

  11. Apoptosis and Its Significance in Oral Diseases: An Update

    Directory of Open Access Journals (Sweden)

    Megha Jain

    2013-01-01

    Full Text Available Apoptosis is a well defined mode of cell death which plays an imperative role in the development, regulation, and maintenance of the cell populations in multicellular organisms. Apoptosis is implicated in both health and diseases. Errors in apoptotic mechanisms have been allied to a wide range of pathologies including oral diseases. This review presents an update focused on the role and significance of apoptosis in various oral diseases ranging from reactive to benign and malignant pathologies.

  12. Molecular mechanisms of TRAIL-induced apoptosis of cancer cells

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    @@Tumor Necrosis Factor-related Apoptosis-inducing Ligand (TRAIL) is a recently identified member of the tumor necrosis factor (TNF) family[1]. Numerous studies indicate that TRAIL can induce apoptosis of cancer cells but not of normal cells, pointing to the possibility of de-veloping TRAIL into a cancer drug[2-4]. This review will summary the molecular mechanisms of TRAIL-induced apoptosis and discuss the questions to be resolved in this field.

  13. Prevention of osteocyte and osteoblast apoptosis by bisphosphonates and calcitonin

    OpenAIRE

    Plotkin, Lilian I.; Weinstein, Robert S; Parfitt, A. Michael; Roberson, Paula K.; Manolagas, Stavros C.; Bellido, Teresita

    1999-01-01

    Glucocorticoid-induced osteoporosis may be due, in part, to increased apoptosis of osteocytes and osteoblasts, and bisphosphonates (BPs) are effective in the management of this condition. We have tested the hypothesis that BPs suppress apoptosis in these cell types. Etidronate, alendronate, pamidronate, olpadronate, or amino-olpadronate (IG9402, a bisphosphonate that lacks antiresorptive activity) at 10–9 to 10–6 M prevented apoptosis of murine osteocytic MLO-Y4 cells, whether it was induced ...

  14. Synthesis of cationic star polymers by simplified electrochemically mediated ATRP

    Directory of Open Access Journals (Sweden)

    P. Chmielarz

    2016-10-01

    Full Text Available Cyclodextrin-based cationic star polymers were synthesized using β-cyclodextrin (β-CD core, and 2-(dimethylamino ethyl methacrylate (DMAEMA as hydrophilic arms. Star-shaped polymers were prepared via a simplified electrochemically mediated ATRP (seATRP under potentiostatic and galvanostatic conditions. The polymerization results showed molecular weight (MW evolution close to theoretical values, and maintained narrow molecular weight distribution (MWD of obtained stars. The rate of the polymerizations was controlled by applying more positive potential values thereby suppressing star-star coupling reactions. Successful chain extension of the ω-functional arms with a hydrophobic n-butyl acrylate (BA formed star block copolymers and confirmed the living nature of the β-CD-PDMAEMA star polymers prepared by seATRP. Novelty of this work is that the β-CD-PDMAEMA-b-PBA cationic star block copolymers were synthesized for the first time via seATRP procedure, utilizing only 40 ppm of catalyst complex. The results from 1H NMR spectral studies support the formation of cationic star (copolymers.

  15. Selective Facet Reactivity During Cation Exchange in Cadmium Sulfide Nanorods

    Energy Technology Data Exchange (ETDEWEB)

    Sadtler, Bryce; Demchenko, Denis; Zheng, Haimei; Hughes, Steven; Merkle, Maxwell; Dahmen, Ulrich; Wang, Lin-Wang; Alivisatos, A. Paul

    2008-12-18

    The partial transformation of ionic nanocrystals through cation exchange has been used to synthesize nanocrystal heterostructures. We demonstrate that the selectivity for cation exchange to take place at different facets of the nanocrystal plays an important role in determining the resulting morphology of the binary heterostructure. In the case of copper I (Cu+) cation exchange in cadmium sulfide (CdS) nanorods, the reaction starts preferentially at the ends of the nanorods such that copper sulfide (Cu2S) grows inwards from either end. The resulting morphology is very different from the striped pattern obtained in our previous studies of silver I (Ag+) exchange in CdS nanorods where non-selective nucleation of silver sulfide (Ag2S) occurs. From interface formation energies calculated for several models of epitaxialconnections between CdS and Cu2S or Ag2S, we infer the relative stability of each interface during the nucleation and growth of Cu2S or Ag2S within the CdS nanorods. The epitaxial connections of Cu2S to the end facets of CdS nanorods minimize the formation energy, making these interfaces stable throughout the exchange reaction. However, as the two end facets of wurtzite CdS nanorods are crystallographically nonequivalent, asymmetric heterostructures can be produced.

  16. Mono- and di-cationic hydrido boron compounds.

    Science.gov (United States)

    Ghadwal, Rajendra S; Schürmann, Christian J; Andrada, Diego M; Frenking, Gernot

    2015-08-28

    Brønsted acid HNTf2 (Tf = SO2CF3) mediated dehydrogenative hydride abstraction from (L(1))BH3 () and (L(2))BH3 () (L(1) = IPrCH2 = 1,3-(2,6-di-isopropylphenyl)imidazol-2-methylidene (); L(2) = SIPrCH2 = 1,3-(2,6-di-isopropylphenyl)imidazolidin-2-methylidiene ()) affords thermally stable hydride bridged mono-cationic hydrido boron compounds [{(L(1))BH2}2(μ-H)](NTf2) () and [{(L(2))BH2}2(μ-H)](NTf2) (). Furthermore, hydride abstraction yields di-cationic hydrido boron compounds [{(L(1))BH}2(μ-H)2](NTf2)2 () and [{(L(2))BH}2(μ-H)2](NTf2)2 (). Unique cationic boron compounds with CH2BH2(μ-H)BH2CH2 ( and ) and CH2BH(μ-H)2BHCH2 ( and ) moieties feature a 3c-2e bond and have been fully characterized. Interesting electronic and structural features of compounds are analysed using spectroscopic, crystallographic, and computational methods. PMID:26200103

  17. Solidification cracking in austenitic stainless steel welds

    Indian Academy of Sciences (India)

    V Shankar; T P S Gill; S L Mannan; S Sundaresan

    2003-06-01

    Solidification cracking is a significant problem during the welding of austenitic stainless steels, particularly in fully austenitic and stabilized compositions. Hot cracking in stainless steel welds is caused by low-melting eutectics containing impurities such as S, P and alloy elements such as Ti, Nb. The WRC-92 diagram can be used as a general guide to maintain a desirable solidification mode during welding. Nitrogen has complex effects on weld-metal microstructure and cracking. In stabilized stainless steels, Ti and Nb react with S, N and C to form low-melting eutectics. Nitrogen picked up during welding significantly enhances cracking, which is reduced by minimizing the ratio of Ti or Nb to that of C and N present. The metallurgical propensity to solidification cracking is determined by elemental segregation, which manifests itself as a brittleness temperature range or BTR, that can be determined using the varestraint test. Total crack length (TCL), used extensively in hot cracking assessment, exhibits greater variability due to extraneous factors as compared to BTR. In austenitic stainless steels, segregation plays an overwhelming role in determining cracking susceptibility.

  18. Transformation of anthracene on various cation-modified clay minerals.

    Science.gov (United States)

    Li, Li; Jia, Hanzhong; Li, Xiyou; Wang, Chuanyi

    2015-01-01

    In this study, anthracene was employed as a probe to explore the potential catalytic effect of clay minerals in soil environment. Clay minerals saturated with various exchangeable cations were tested. The rate of anthracene transformation follows the order: Fe-smectite > Cu-smectite > Al-smectite ≈ Ca-smectite ≈ Mg-smectite ≈ Na-smectite. This suggests that transition-metal ions such as Fe(III) play an important role in anthracene transformation. Among Fe(III)-saturated clays, Fe(III)-smectite exhibits the highest catalytic activity followed by Fe(III)-illite, Fe(III)-pyrophyllite, and Fe(III)-kaolinite, which is in agreement with the interlayer Fe(III) content. Moreover, effects by two common environmental factors, pH and relative humidity (RH), were evaluated. With an increase in pH or RH, the rate of anthracene transformation decreases rapidly at first and then is leveled off. GC-MS analysis identifies that the final product of anthracene transformation is 9,10-anthraquinone, a more bioavailable molecule compared to anthracene. The transformation process mainly involves cation-π bonding, electron transfer leading to cation radical, and further oxidation by chemisorbed O2. The present work provides valuable insights into the abiotic transformation and the fate of PAHs in the soil environment and the development of contaminated land remediation technologies.

  19. Cationic lipid membranes-specific interactions with counter-ions

    International Nuclear Information System (INIS)

    Lipids bearing net electric charges in their hydrophilic headgroups are ubiquitous in biological membranes. Recently, the interest in cationic lipids has surged because of their potential as non-viral transfection vectors. In order to utilize cationic lipids in transfer of nucleic acids and to elucidate the role of charged lipids in cellular membranes in general, their complex interactions within the membrane and with the molecules in the surrounding media need to be thoroughly characterized. Yet, even interactions between monovalent counter-ions and charged lipids are inadequately understood. We studied the interactions of the cationic gemini surfactant (2R,3R)-2,3-dimethoxy-1,4- bis(N-hexadecyl-N,N-dimethylammonium)butane dibromide (RR-1) with chloride, bromide, fluoride, and iodide as counter-ions by differential scanning calorimetry and Langmuir balance. Chloride interacts avidly with RR-1, efficiently condensing the monolayer, decreasing the collapse pressure, and elevating the main transition temperature. With bromide and iodide clearly different behaviour was observed, indicating specific interactions between RR-1 and these counter-ions. Moreover, with fluoride as a counter-ion and in pure water identical results were obtained, demonstrating inefficient electrostatic screening of the headgroups of RR-1 and suggesting fluoride being depleted on the surface of RR-1 membranes

  20. Cationic lipid membranes-specific interactions with counter-ions

    Energy Technology Data Exchange (ETDEWEB)

    Ryhaenen, Samppa J; Saeily, V Matti J; Kinnunen, Paavo K J [Helsinki Biophysics and Biomembrane Group, Institute of Biomedicine, Biomedicum, University of Helsinki, PO Box 63 (Haartmaninkatu 8), Helsinki FIN-00014 (Finland)

    2006-07-19

    Lipids bearing net electric charges in their hydrophilic headgroups are ubiquitous in biological membranes. Recently, the interest in cationic lipids has surged because of their potential as non-viral transfection vectors. In order to utilize cationic lipids in transfer of nucleic acids and to elucidate the role of charged lipids in cellular membranes in general, their complex interactions within the membrane and with the molecules in the surrounding media need to be thoroughly characterized. Yet, even interactions between monovalent counter-ions and charged lipids are inadequately understood. We studied the interactions of the cationic gemini surfactant (2R,3R)-2,3-dimethoxy-1,4- bis(N-hexadecyl-N,N-dimethylammonium)butane dibromide (RR-1) with chloride, bromide, fluoride, and iodide as counter-ions by differential scanning calorimetry and Langmuir balance. Chloride interacts avidly with RR-1, efficiently condensing the monolayer, decreasing the collapse pressure, and elevating the main transition temperature. With bromide and iodide clearly different behaviour was observed, indicating specific interactions between RR-1 and these counter-ions. Moreover, with fluoride as a counter-ion and in pure water identical results were obtained, demonstrating inefficient electrostatic screening of the headgroups of RR-1 and suggesting fluoride being depleted on the surface of RR-1 membranes.

  1. Specific cationic emission of cisplatin following ionization by swift protons

    Science.gov (United States)

    Moretto-Capelle, Patrick; Champeaux, Jean-Philippe; Deville, Charlotte; Sence, Martine; Cafarelli, Pierre

    2016-05-01

    We have investigated collision-induced ionization and fragmentation by 100 keV protons of the radio sensitizing molecule cisplatin, which is used in cancer treatments. A large emission of HCl+ and NH2+ is observed, but surprisingly, no cationic fragments containing platinum are detected, in contrast to ionization-dissociation induced by electronic collision. Theoretical investigations show that the ionization processes take place on platinum and on chlorine atoms. We propose new ionization potentials for cisplatin. Dissociation limits corresponding to the measured fragmentation mass spectrum have been evaluated and the theoretical results show that the non-observed cationic fragments containing platinum are mostly associated with low dissociation energies. We have also investigated the reaction path for the hydrogen transfer from the NH3 group to the Cl atom, as well as the corresponding dissociation limits from this tautomeric form. Here again the cations containing platinum correspond to lower dissociation limits. Thus, the experimental results suggest that excited states, probably formed via inner-shell ionization of the platinum atom of the molecule, correlated to higher dissociation limits are favored.

  2. Naphthoxy Bounded Ferrocenium Salts as Cationic Photoinitiators for Epoxy Photopolymerization

    Directory of Open Access Journals (Sweden)

    Zh. Q. Li

    2009-01-01

    Full Text Available To improve the absorption and the bulk of arene ligands, two naphthoxy bounded ferrocenium salts as new cationic photoinitiators, (η6-α-naphthoxybenzene (η5-cyclopentadienyl iron hexafluorophosphate (NOFC-1 and (η6-β-naphthoxybenzene (η5-cyclopentadienyl iron hexafluorophosphate (NOFC-2, were synthesized, characterized, and studied. NOFC-1 and NOFC-2 were prepared by the reaction of nucleophilic substitution (SNAr with naphthol and chlorobenzene-cyclopentadienyliron salt. Their activity as cationic photoinitiators was studied using real-time infrared spectroscopy. The results obtained showed that NOFC-1 and NOFC-2 are capable of photoinitiating the cationic polymerization of epoxy monomer directly on irradiation with long-wavelength UV light (365 nm. Comparative studies also demonstrated that they exhibited better efficiency than cyclopentadienyl-Fe-cymene hexafluorophosphate (I-261. When NOFC-1 and NOFC-2 were used to efficiently initiate polymerization of epoxide, both rate of polymerization and final conversion increased using benzoyl peroxide (BPO as sensitizer. DSC studies showed that NOFC-1 and NOFC-2 photoinitiators in epoxides possess good thermal stability in the absence of light.

  3. Effect of heavy metal cations on the activity of cathepsin D (in vitro study) Effect of heavy metal cations on the activity of cathepsin D (in vitro study)

    OpenAIRE

    Alicja Karwowska; Radosław Łapiński; Marek Gacko; Ewa Grzegorczyk; Joanna Żurawska; Jan K. Karczewski

    2012-01-01

    We studied the effect of heavy metal cations: Fe 2+, Cu2+, Zn2+, Cd2+, Hg2+, Pb2+ on the activity of
    cathepsin D in human aorta homogenate and blood serum. The concentration of cations was 1 mmol/l. Hemoglobin
    was the cathepsin D substrate. The activity of cathepsin D was determined at pH 3.5. Only Hg2+ cations
    inhibit the activity of cathepsin D. Cations Hg2+ damage lysosomes and release cathepsin D from these organelles.We studied the effect of heavy metal c...

  4. Induction of Apoptosis in Protoplasts and Suspension Cultures of Plant Cells

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Many studies have showed that apoptosis exists in plants. Our study shows that (1) menadione(VK3) induces apoptosis in suspension cultures of carrot cells; (2) heat shock induces apoptosis in suspension cultures of tobacco cells; and (3) ethrel induces apoptosis in carrot protoplasts. Some important indications of apoptosis were observed, including DNA laddering, TUNEL-positive reaction, condensation and degradation of nuclei.

  5. Carbamate Pesticide-Induced Apoptosis in Human T Lymphocytes

    Directory of Open Access Journals (Sweden)

    Qing Li

    2015-04-01

    Full Text Available We previously found that carbamate pesticides induced significant apoptosis in human natural killer cells. To investigate whether carbamate pesticides also induce apoptosis in human T lymphocytes, in the present study Jurkat human T cells were treated in vitro with thiram, maneb, carbaryl or ziram. Apoptosis was determined by FITC-Annexin-V/PI staining. To explore the mechanism of apoptosis, intracellular levels of active caspase 3 and mitochondrial cytochrome-c release were determined by flow cytometry. We found that thiram, ziram, maneb and carbaryl also induced apoptosis in a time- and dose-dependent manner in the human T cells. However, the strength of the apoptosis-inducing effect differed among the pesticides, with the: thiram > ziram > maneb > carbaryl. Moreover, thiram significantly increased the intracellular level of active caspase 3 and caspase inhibitors significantly inhibited apoptosis. Thiram also significantly caused mitochondrial cytochrome-c release. These findings indicate that carbamate pesticides can induce apoptosis in human T cells, and the apoptosis is mediated by the activation of caspases and the release of mitochondrial cytochrome-c.

  6. Shifting the balance of mitochondrial apoptosis: therapeutic perspectives

    Directory of Open Access Journals (Sweden)

    Simone eFulda

    2012-10-01

    Full Text Available Signaling via the intrinsic (mitochondrial pathway of apoptosis represents one of the critical signal transduction cascades that control the regulation of cell death. This pathway is typically altered in human cancers, thereby providing a suitable target for therapeutic intervention. Members of the Bcl-2 family of proteins as well as cell survival signaling cascades such as the PI3K/Akt/mTOR pathway are involved in the regulation of mitochondria-mediated apoptosis. Therefore, further insights into the molecular mechanisms that form the basis for the control of mitochondria-mediated apoptosis will likely open new perspectives to bypass evasion of apoptosis and treatment resistance in human cancers.

  7. Apoptosis of gingival fibroblasts in periodontitis.

    Directory of Open Access Journals (Sweden)

    Roger Mauricio Arce

    2009-11-01

    Full Text Available Introducción: Los fibroblastos gingivales humanos (FGH tienen un papel importante en la enfermedad periodontal, pues alteran su normal funcionamiento en respuesta a estímulos pro-inflamatorios. Se cree que los fibroblastos se pueden eliminar anormalmente por medio de apoptosis en periodontitis. El propósito de este estudio es determinar y cuantificar la apoptosis de FGH en biopsias del periodonto de individuos sanos y con enfermedad periodontal. Métodos: Se realizó un estudio clínico descriptivo de corte transversal en personas con diagnóstico de salud periodontal (S, gingivitis (G y periodontitis crónica (PC. Se tomaron biopsias escisionales y se hicieron tinciones inmunohistoquímicas (hematoxilina-eosina, caspasa-3 y vimentina. Las placas se interpretaron por histopatología y se digitalizaron para cuantificar las células apoptóticas. Todos los datos se analizaron con un software estadístico para encontrar diferencias significativas (p Resultados: La población celular total de fibroblastos tuvo un promedio de 430±67.6 en los individuos sanos y una disminución significativamente progresiva en gingivitis (270±37.1 y periodontitis crónica (206.5±69.8 (p0.5, r²=0.02; mientras que para las células inflamatorias se encontró una relación proporcional significativa (p Conclusiones: Los resultados permiten concluir que tanto los fibroblastos gingivales como las células inflamatorias presentan apoptosis manifiesta por la expresión de caspasa-3, y ésta se incrementa significativamente en gingivitis y enfermedad periodontal.

  8. Crystal structure of channelrhodopsin, a light-gated cation channel – all cations lead through the monomer –

    Science.gov (United States)

    Kato, Hideaki E.; Nureki, Osamu

    2013-01-01

    Channelrhodopsin (ChR) is a light-gated cation channel derived from green algae. Since the inward flow of cations triggers the neuron firing, neurons expressing ChRs can be optically controlled even within freely moving mammals. Although ChR has been broadly applied to neuro-science research, little is known about its molecular mechanisms. We determined the crystal structure of chimeric ChR at 2.3 Å resolution and revealed its molecular architecture. The integration of structural, electrophysio-logical, and computational analyses provided insight into the molecular basis for the channel function of ChR, and paved the way for the principled design of ChR variants with novel properties. PMID:27493541

  9. Ultrasonic dyeing of cationized cotton fabric with natural dye. Part 1: cationization of cotton using Solfix E.

    Science.gov (United States)

    Kamel, M M; El Zawahry, M M; Ahmed, N S E; Abdelghaffar, F

    2009-02-01

    The dyeing of cationized cotton fabric with Solfix E using colouring matter extracted from Cochineal dye has been studied using both conventional and ultrasonic techniques. Factors affecting dye extraction such as ultrasound power, particle size, extraction temperature and time were studied. The results indicated that the extraction by ultrasound at 300 W was more effective at lower temperature and time than conventional extraction. The effect of various factors of dye bath such as pH, salt concentration, ultrasound power, dyeing time and temperature were investigated. The colour strength values obtained were found to be higher with ultrasound than with conventional techniques. The results of fastness properties of the dyed fabrics were fair to good. The scanning electron microscope (SEM) images of the morphological and X-ray analyzes were measured for cationized cotton fabrics dyed with both conventional and ultrasound methods, thus showing the sonicator efficiency. PMID:18812264

  10. Adsorption of reovirus to clay minerals: effects of cation-exchange capacity, cation saturation, and surface area.

    OpenAIRE

    Lipson, S M; Stotzky, G

    1983-01-01

    The adsorption of reovirus to clay minerals has been reported by several investigators, but the mechanisms defining this association have been studied only minimally. The purpose of this investigation was to elucidate the mechanisms involved with this interaction. More reovirus type 3 was adsorbed, in both distilled and synthetic estuarine water, by low concentrations of montmorillonite than by comparable concentrations of kaolinite containing a mixed complement of cations on the exchange com...

  11. Differences in toxicity of anionic and cationic PAMAM and PPI dendrimers in zebrafish embryos and cancer cell lines.

    Science.gov (United States)

    Bodewein, Lambert; Schmelter, Frank; Di Fiore, Stefano; Hollert, Henner; Fischer, Rainer; Fenske, Martina

    2016-08-15

    Dendrimers are an emerging class of polymeric nanoparticles with beneficial biomedical applications like early diagnostics, in vitro gene transfection or controlled drug delivery. However, the potential toxic impact of exposure on human health or the environment is often inadequately defined. Thus, polyamidoamine (PAMAM) dendrimers of generations G3.0, 3.5, 4.0, 4.5 and 5.0 and polypropylenimine (PPI) dendrimers G3.0, 4.0 and 5.0 were tested in zebrafish embryos for 96h and human cancer cell lines for 24h, to assess and compare developmental in vivo toxicity with cytotoxicity. The zebrafish embryo toxicity of cationic PAMAM and PPI dendrimers increased over time, with EC50 values ranging from 0.16 to just below 1.7μM at 24 and 48hpf. The predominant effects were mortality, plus reduced heartbeat and blood circulation for PPI dendrimers. Apoptosis in the embryos increased in line with the general toxicity concentration-dependently. Hatch and dechorionation of the embryos increased the toxicity, suggesting a protective role of the chorion. Lower generation dendrimers were more toxic in the embryos whereas the toxicity in the HepG2 and DU145 cell lines increased with increasing generation of cationic PAMAMs and PPI dendrimers. HepG2 were less sensitive than DU145 cells, with IC50 values≥402μM (PAMAMs) and ≤240μM (PPIs) for HepG2 and ≤13.24μM (PAMAMs) and ≤12.84μM (PPIs) for DU145. Neither in fish embryos nor cells toxicity thresholds were determinable for anionic PAMAM G3.5 and G4.5. The study demonstrated that the cytotoxicity underestimated the in-vivo toxicity of the dendrimers in the fish embryos. PMID:27288734

  12. Lysosomotropic cationic drugs induce cytostatic and cytotoxic effects: Role of liposolubility and autophagic flux and antagonism by cholesterol ablation.

    Science.gov (United States)

    Parks, Alexandre; Marceau, François

    2016-08-15

    Cation trapping in acidic cell compartments determines an antiproliferative effect that has a potential interest in oncology, as shown by clinical data and trials involving chloroquine and hydroxychloroquine. To further characterize the mechanism of this effect, we studied a series of 6 substituted triethylamine (s-Et3N) drugs that encompasses a wide range of liposolubility (amiodarone, quinacrine, chloroquine, hydroxychloroquine, lidocaine, and procainamide). Three tumor cell lines and primary human endothelial cells were exploited in proliferation assays (48h, cell counts). Accumulation of the autophagic effector LC3 II and the apoptotic marker cleaved PARP1 (immunoblots), cytotoxicity, cell cycle analysis and endocytic function were further tested in the p53-null histiocytic lymphoma U937 line. A profound and desynchronized antiproliferative effect was observed in response to all s-Et3Ns with essentially no cell type specificity. Predictors of s-Et3N potency were liposolubility and the acute accumulation of the autophagic effector LC3 II (6h-treatments). For each s-Et3N, there was an antiproliferative concentration range where cytotoxicity and apoptosis were not triggered in U937 cells (24-48h-treatments). Quinacrine was the most potent cytostatic drug (1-5μM). Co-treatment of cells with inhibitors of cholesterol, β-cyclodextrin or lovastatin, partially reversed the antiproliferative effect of each s-Et3N. The cytopathology induced by cationic drug accumulation includes a cytostatic effect. Its intensity is cell type- and p53-independent, but predicted by the inhibition of autophagic flux and by the liposolubility of individual drugs and alleviated by cholesterol ablation. The superiority of quinacrine, biomarker value of LC3 II and antagonism by a statin may be clinically relevant. PMID:27288732

  13. Lipolysis stimulating peptides of potato protein hydrolysate effectively suppresses high-fat-diet-induced hepatocyte apoptosis and fibrosis in aging rats

    Science.gov (United States)

    Chiang, Wen-Dee; Huang, Chih Yang; Paul, Catherine Reena; Lee, Zong-Yan; Lin, Wan-Teng

    2016-01-01

    Background Non-alcoholic fatty liver disease (NAFLD) is one of the most common outcomes of obesity and is characterized by the accumulation of triglycerides, increased tissue apoptosis, and fibrosis. NAFLD is more common among elderly than in younger age groups, and it causes serious hepatic complications. Objective In this study, alcalase treatment derived potato protein hydrolysate (APPH) with lipolysis-stimulating property has been evaluated for its efficiency to provide hepato-protection in a high-fat-diet (HFD)-fed aging rats. Design Twenty-four-month-old SD rats were randomly divided into six groups (n=8): aged rats fed with standard chow, HFD-induced aged obese rats, HFD with low-dose (15 mg/kg/day) APPH treatment, HFD with moderate (45 mg/kg/day) APPH treatment, HFD with high (75 mg/kg/day) APPH treatment, and HFD with probucol. Results APPH was found to reduce the NAFLD-related effects in rat livers induced by HFD and all of the HFD-fed rats exhibited heavier body weight than those with control chow diet. However, the HFD-induced hepatic fat accumulation was effectively attenuated in rats administered with low (15 mg/kg/day), moderate (45 mg/kg/day), and high (75 mg/kg/day) doses of APPH. APPH oral administration also suppressed the hepatic apoptosis- and fibrosis-related proteins induced by HFD. Conclusions Our results thus indicate that APPH potentially attenuates hepatic lipid accumulation and anti-apoptosis and fibrosis effects in HFD-induced rats. APPH may have therapeutic potential in the amelioration of NAFLD liver damage. PMID:27415158

  14. Lipolysis stimulating peptides of potato protein hydrolysate effectively suppresses high-fat-diet-induced hepatocyte apoptosis and fibrosis in aging rats

    Directory of Open Access Journals (Sweden)

    Wen-Dee Chiang

    2016-07-01

    Full Text Available Background: Non-alcoholic fatty liver disease (NAFLD is one of the most common outcomes of obesity and is characterized by the accumulation of triglycerides, increased tissue apoptosis, and fibrosis. NAFLD is more common among elderly than in younger age groups, and it causes serious hepatic complications. Objective: In this study, alcalase treatment derived potato protein hydrolysate (APPH with lipolysis-stimulating property has been evaluated for its efficiency to provide hepato-protection in a high-fat-diet (HFD-fed aging rats. Design: Twenty-four-month-old SD rats were randomly divided into six groups (n=8: aged rats fed with standard chow, HFD-induced aged obese rats, HFD with low-dose (15 mg/kg/day APPH treatment, HFD with moderate (45 mg/kg/day APPH treatment, HFD with high (75 mg/kg/day APPH treatment, and HFD with probucol. Results: APPH was found to reduce the NAFLD-related effects in rat livers induced by HFD and all of the HFD-fed rats exhibited heavier body weight than those with control chow diet. However, the HFD-induced hepatic fat accumulation was effectively attenuated in rats administered with low (15 mg/kg/day, moderate (45 mg/kg/day, and high (75 mg/kg/day doses of APPH. APPH oral administration also suppressed the hepatic apoptosis- and fibrosis-related proteins induced by HFD. Conclusions: Our results thus indicate that APPH potentially attenuates hepatic lipid accumulation and anti-apoptosis and fibrosis effects in HFD-induced rats. APPH may have therapeutic potential in the amelioration of NAFLD liver damage.

  15. The role of casein-specific IgA and TGF-β in children with Food Protein-Induced Enterocolitis Syndrome to milk

    Science.gov (United States)

    Konstantinou, George N.; Bencharitiwong, Ramon; Grishin, Alexander; Caubet, Jean-Christoph; Bardina, Luda; Sicherer, Scott H.; Sampson, Hugh A.; Nowak-Węgrzyn, Anna

    2014-01-01

    Background Food protein-induced enterocolitis syndrome (FPIES) is a gastrointestinal hypersensitivity disorder with a poorly understood pathophysiology and no biomarkers to aid in diagnosis. Objective To investigate humoral and cellular responses to casein in children with milk-FPIES, including the role of casein-specific (cs) IgA and T-cell mediated TGF-β responses. Patients and methods Thirty-one children previously diagnosed with milk-FPIES were challenged with milk. Twelve age-matched children with FPIES to other foods and 6 milk-tolerant children without a history of FPIES were used as controls. Casein-specific IgE, IgG, IgG4 and IgA were measured in serum and TGF-β levels in supernatants of casein-stimulated PBMCs. Result Twenty-six children with milk-FPIES reacted (active milk-FPIES) and five tolerated milk (milk-FPIES-resolved) during food challenge. All of them had significantly lower levels of csIgG, csIgG4 and csIgA than control children (p-value<0.001). There were no TGF-β responses in supernatants of active milk-FPIES children. Conclusion Children with milk-FPIES have low levels of csIgG, csIgG4 and csIgA. In particular, children with active FPIES to cow’s milk have deficient T-cell mediated TGF-β responses to casein, rendering TGF-β a promising biomarker in identifying children who are likely to experience FPIES reactions to this allergen. Prospective studies are needed to validate these findings, elucidate their role in FPIES pathophysiology and establish the diagnostic utility of TGF-β in milk-induced FPIES. PMID:25283440

  16. Diagnostic Performance of Alpha-Fetoprotein, Protein Induced by Vitamin K Absence, Osteopontin, Dickkopf-1 and Its Combinations for Hepatocellular Carcinoma.

    Directory of Open Access Journals (Sweden)

    Eun Sun Jang

    Full Text Available Alpha-fetoprotein (AFP is the most widely used serum biomarker for hepatocellular carcinoma (HCC, despite its limitations. As complementary biomarkers, protein induced by vitamin K absence (PIVKA-II, osteopontin (OPN, and Dickkopf-1 (DKK-1 have been proposed. This study aimed to perform a head-to-head comparison of the diagnostic performance of AFP, PIVKA-II, OPN and DKK-1 as single or in combination to seek the best biomarker or panel, and to investigate the clinical factors affecting their performance.Using 401 stored plasma samples obtained from 208 HCC patients and 193 liver cirrhosis control patients, plasma AFP, PIVKA-II, OPN and DKK-1 levels were measured by ELISA, and receiver operating characteristic curve analyses were performed for each biomarker and for every combination of two to four markers.Of the four biomarkers, AFP showed the highest area under the curve (0.786. The sensitivity and specificity for each single biomarker was 62% and 90.2% (AFP>20 ng/mL, 51.0% and 91.2% (PIVKA-II>10 ng/mL, 46.2% and 80.3% (OPN>100 ng/mL, and 50.0% and 80.8% (DKK-1>500 pg/mL, respectively. Among the combinations of two biomarkers, AFP>20 ng/mL or DKK-1>500 pg/mL showed the best diagnostic performance (sensitivity 78.4%, specificity 72.5%. Triple or quadruple combination did not improve the diagnostic performance further. The patient's age, etiology and tumor invasiveness of HCC affected the performance of each marker.AFP was the most useful single biomarker for HCC diagnosis, and the combined measurement of AFP and DKK-1 could maximize the diagnostic yield. Clinical decision should be based on the consideration of various factors affecting the diagnostic performance of each biomarker. Efforts to seek novel HCC biomarkers should be continued.

  17. Effects of Hofmeister salt series on gluten network formation: Part I. Cation series.

    Science.gov (United States)

    Tuhumury, H C D; Small, D M; Day, L

    2016-12-01

    Different cationic salts were used to investigate the effects of the Hofmeister salt series on gluten network formation. The effects of cationic salts on wheat flour dough mixing properties, the rheological and the chemical properties of the gluten extracted from the dough with different respective salts, were investigated. The specific influence of different cationic salts on the gluten structure formation during dough mixing, compared to the sodium ion, were determined. The effects of different cations on dough and gluten of different flours mostly followed the Hofmeister series (NH4(+), K(+), Na(+), Mg(2+) and Ca(2+)). The impacts of cations on gluten structure and dough rheology at levels tested were relatively small. Therefore, the replacement of sodium from a technological standpoint is possible, particularly by monovalent cations such as NH4(+), or K(+). However the levels of replacement need to take into account sensory attributes of the cationic salts. PMID:27374596

  18. Helicobacter pylori vacuolating toxin A and apoptosis

    Directory of Open Access Journals (Sweden)

    Rassow Joachim

    2011-11-01

    Full Text Available Abstract VacA, the vacuolating cytotoxin A of Helicobacter pylori, induces apoptosis in epithelial cells of the gastic mucosa and in leukocytes. VacA is released by the bacteria as a protein of 88 kDa. At the outer surface of host cells, it binds to the sphingomyelin of lipid rafts. At least partially, binding to the cells is facilitated by different receptor proteins. VacA is internalized by a clathrin-independent mechanism and initially accumulates in GPI-anchored proteins-enriched early endosomal compartments. Together with early endosomes, VacA is distributed inside the cells. Most of the VacA is eventually contained in the membranes of vacuoles. VacA assembles in hexameric oligomers forming an anion channel of low conductivity with a preference for chloride ions. In parallel, a significant fraction of VacA can be transferred from endosomes to mitochondria in a process involving direct endosome-mitochondria juxtaposition. Inside the mitochondria, VacA accumulates in the mitochondrial inner membrane, probably forming similar chloride channels as observed in the vacuoles. Import into mitochondria is mediated by the hydrophobic N-terminus of VacA. Apoptosis is triggered by loss of the mitochondrial membrane potential, recruitment of Bax and Bak, and release of cytochrome c.

  19. The Adipokine Chemerin Induces Apoptosis in Cardiomyocytes

    Directory of Open Access Journals (Sweden)

    Diego Rodríguez-Penas

    2015-08-01

    Full Text Available Background: The adipokine chemerin has been associated with cardiovascular disease. We investigated the effects of chemerin on viability and intracellular signalling in murine cardiomyocytes, and the effects of insulin and TNF-α on cardiomyocyte chemerin production. Methods: Hoechst dye vital staining and cell cycle analysis were used to analyse the viability of murine cardiac cells in culture. Western blot was used to explore the phosphorylation of AKT and caspase-9 activity in neonatal rat cardiomyocytes and HL-1 cells. Finally, RT-qPCR, ELISA and western blot were performed to examine chemerin and CMKLR1 expression after insulin and TNF-α treatment in cardiac cells. Results: Chemerin treatment increased apoptosis, reduced phosphorylation of AKT at Thr308 and increased caspase-9 activity in murine cardiomyocytes. Insulin treatment lowered chemerin and CMKLR1 mRNA and protein levels, and the amount of chemerin in the cell media, while TNF-α treatment increased chemerin mRNA and protein levels but decreased expression of the CMKLR1 gene. Conclusion: Chemerin induces apoptosis, reduces AKT phosphorylation and increases the cleavage of caspase-9 in murine cardiomyocytes. The expression of chemerin is regulated by important metabolic (insulin and inflammatory (TNF-α mediators at cardiac level. Our results suggest that chemerin could play a role in the physiopathology of cardiac diseases.

  20. Mitochondria in human pluripotent stem cell apoptosis.

    Science.gov (United States)

    TeSlaa, Tara; Setoguchi, Kiyoko; Teitell, Michael A

    2016-04-01

    Human pluripotent stem cells (hPSCs) have great potential in regenerative medicine because they can differentiate into any cell type in the body. Genome integrity is vital for human development and for high fidelity passage of genetic information across generations through the germ line. To ensure genome stability, hPSCs maintain a lower rate of mutation than somatic cells and undergo rapid apoptosis in response to DNA damage and additional cell stresses. Furthermore, cellular metabolism and the cell cycle are also differentially regulated between cells in pluripotent and differentiated states and can aid in protecting hPSCs against DNA damage and damaged cell propagation. Despite these safeguards, clinical use of hPSC derivatives could be compromised by tumorigenic potential and possible malignant transformation from failed to differentiate cells. Since hPSCs and mature cells differentially respond to cell stress, it may be possible to specifically target undifferentiated cells for rapid apoptosis in mixed cell populations to enable safer use of hPSC-differentiated cells in patients. PMID:26828436

  1. Effect of heavy metal cations on the activity of cathepsin D (in vitro study Effect of heavy metal cations on the activity of cathepsin D (in vitro study

    Directory of Open Access Journals (Sweden)

    Alicja Karwowska

    2012-10-01

    Full Text Available We studied the effect of heavy metal cations: Fe 2+, Cu2+, Zn2+, Cd2+, Hg2+, Pb2+ on the activity of
    cathepsin D in human aorta homogenate and blood serum. The concentration of cations was 1 mmol/l. Hemoglobin
    was the cathepsin D substrate. The activity of cathepsin D was determined at pH 3.5. Only Hg2+ cations
    inhibit the activity of cathepsin D. Cations Hg2+ damage lysosomes and release cathepsin D from these organelles.We studied the effect of heavy metal cations: Fe 2+, Cu2+, Zn2+, Cd2+, Hg2+, Pb2+ on the activity of
    cathepsin D in human aorta homogenate and blood serum. The concentration of cations was 1 mmol/l. Hemoglobin
    was the cathepsin D substrate. The activity of cathepsin D was determined at pH 3.5. Only Hg2+ cations
    inhibit the activity of cathepsin D. Cations Hg2+ damage lysosomes and release cathepsin D from these organelles.

  2. Electronic spectra of isolated cations in supersonic jets by mass-selected ion-dip spectroscopy. Cations of benzene, p-difluorobenzene, and 1,3,5-trifluorobenzene

    Science.gov (United States)

    Tsuchiya, Yuko; Fujii, Masaaki; Ito, Mitsuo

    1989-06-01

    The electronic transitions of the cations of benzene, p-difluorobenzene (p-DFB), and 1,3,5-trifluorobenzene (1,3,5-TFB) have been measured by mass-selected ion-dip spectroscopy which utilizes the dissociation of a parent cation in an excited state. This spectroscopy was successfully applied to the vibrational level selected cation in the ground electronic state which was prepared by 1+1 REMPI (resonant enhanced multiphoton ionization) of the neutral molecule in a supersonic jet. For all the cations, the spectra due to the transition from the ground state to the excited π,π state were observed. Ion-dip spectra having sharp vibrational structures were found for p-DFB and 1,3,5-TFB cations, while a broad spectrum was observed for a benzene cation. It was also found that the vibrational structure of the ion-dip spectrum of the 1,3,5-TFB cation is quite different from that of the fluorescence excitation spectrum. The assignments of the ion-dip spectra and dissociation mechanisms of the excited cations will be discussed.

  3. Reduced hepatic uptake and intestinal excretion of organic cations in mice with a targeted disruption of the organic cation transporter 1 (Oct1 [Slc22a1]) gene

    NARCIS (Netherlands)

    Jonker, JW; Wagenaar, E; Mol, CAAM; Buitelaar, M; Koepsell, H; Smit, JW; Schinkel, AH

    2001-01-01

    The polyspecific organic cation transporter 1 (OCT1 [SLC22A1]) mediates facilitated transport of small (hydrophilic) organic cations. OCT1 is localized at the basolateral membrane of epithelial cells in the liver, kidney, and intestine and could therefore be involved in the elimination of endogenous

  4. Cations form sequence selective motifs within DNA grooves via a combination of cation-pi and ion-dipole/hydrogen bond interactions.

    Directory of Open Access Journals (Sweden)

    Mikaela Stewart

    Full Text Available The fine conformational subtleties of DNA structure modulate many fundamental cellular processes including gene activation/repression, cellular division, and DNA repair. Most of these cellular processes rely on the conformational heterogeneity of specific DNA sequences. Factors including those structural characteristics inherent in the particular base sequence as well as those induced through interaction with solvent components combine to produce fine DNA structural variation including helical flexibility and conformation. Cation-pi interactions between solvent cations or their first hydration shell waters and the faces of DNA bases form sequence selectively and contribute to DNA structural heterogeneity. In this paper, we detect and characterize the binding patterns found in cation-pi interactions between solvent cations and DNA bases in a set of high resolution x-ray crystal structures. Specifically, we found that monovalent cations (Tl⁺ and the polarized first hydration shell waters of divalent cations (Mg²⁺, Ca²⁺ form cation-pi interactions with DNA bases stabilizing unstacked conformations. When these cation-pi interactions are combined with electrostatic interactions a pattern of specific binding motifs is formed within the grooves.

  5. Bacterial pathogens modulate an apoptosis differentiation program in human neutrophils

    OpenAIRE

    Kobayashi, Scott D.; Braughton, Kevin R.; Whitney, Adeline R.; Voyich, Jovanka M.; Schwan, Tom G.; Musser, James M.; DeLeo, Frank R.

    2003-01-01

    Human polymorphonuclear leukocytes (PMNs or neutrophils) are essential to the innate immune response against bacterial pathogens. Recent evidence suggests that PMN apoptosis facilitates resolution of inflammation during bacterial infection. Although progress has been made toward understanding apoptosis in neutrophils, very little is known about transcriptional regulation of this process during bacterial infection. To gain insight into the molecular processes that facilitate resolution of infe...

  6. Resveratrol induces apoptosis in human esophageal carcinoma cells

    Institute of Scientific and Technical Information of China (English)

    Hai-Bo Zhou; Yun Yan; Ya-Ni Sun; Ju-Ren Zhu

    2003-01-01

    AIM: To investigate the apoptosis in esophageal cancer cells induced by resveratrol, and the relation between this apoptosis and expression of Bcl-2 and Bax.METHODS: In in vitro experiments, MTr assay was used to determine the cell growth inhibitory rate. Transmission electron microscope and TUNEL staining method were used to quantitatively and qualitively detect the apoptosis status of esophageal cancer cell line EC-9706 before and after the resveratrol treatment. Immunohistochemical staining was used to detect the expression of apoptosis-regulated gene Bcl-2 and Bax.RESULTS: Resveratrol inhibited the growth of esophageal cancer cell line EC-9706 in a dose-and time-dependent manner. Resveratrol induced EC-9706 cells to undergo apoptosis with typically apoptotic characteristics, including morphological changes of chromatin condensation, chromatin crescent formation, nucleus fragmentation and apoptotic body formation. TUNEL assay showed that after the for 24 to 96 hours, the AIs were apparently increased with treated time (P<0.05). Immunohistochemical staining showed that after the treatment of EC-9706 cells with proteins were apparently reduced with treated time (P<0.05)and the PRs of Bax proteins were apparently increased with treated time (P<0.05).CONCLUSION: Resveratrol is able to induce the apoptosisin esophageal cancer. This apoptosis may be mediated by down-regulating the apoptosis-regulated gene Bcl-2 and upregulating the expression of apoptosis-regulated gene bax.

  7. Apoptosis and T cell depletion during feline infectious peritonitis

    NARCIS (Netherlands)

    Horzinek, M.C.; Haagmans, B.L.; Egberink, H.F.

    1996-01-01

    Cats that have succumbed to feline infectious peritonitis, an immune- mediated disease caused by variants of feline coronaviruses, show apoptosis and T-cell depletion in their lymphoid organs. The ascitic fluid that develops in the course of the condition causes apoptosis in vitro but only in activa

  8. Anion and cation diffusion in barium titanate and strontium titanate

    International Nuclear Information System (INIS)

    Perovskite oxides show various interesting properties providing several technical applications. In many cases the defect chemistry is the key to understand and influence the material's properties. In this work the defect chemistry of barium titanate and strontium titanate is analysed by anion and cation diffusion experiments and subsequent time-of-flight secondary ion mass spectrometry (ToF-SIMS). The reoxidation equation for barium titanate used in multi-layer ceramic capacitors (MLCCs) is found out by a combination of different isotope exchange experiments and the analysis of the resulting tracer diffusion profiles. It is shown that the incorporation of oxygen from water vapour is faster by orders of magnitude than from molecular oxygen. Chemical analysis shows the samples contain various dopants leading to a complex defect chemistry. Dysprosium is the most important dopant, acting partially as a donor and partially as an acceptor in this effectively acceptor-doped material. TEM and EELS analysis show the inhomogeneous distribution of Dy in a core-shell microstructure. The oxygen partial pressure and temperature dependence of the oxygen tracer diffusion coefficients is analysed and explained by the complex defect chemistry of Dy-doped barium titanate. Additional fast diffusion profiles are attributed to fast diffusion along grain boundaries. In addition to the barium titanate ceramics from an important technical application, oxygen diffusion in cubic, nominally undoped BaTiO3 single crystals has been studied by means of 18O2/16O2 isotope exchange annealing and subsequent determination of the isotope profiles in the solid by ToF-SIMS. It is shown that a correct description of the diffusion profiles requires the analysis of the diffusion through the surface space-charge into the material's bulk. Surface exchange coefficients, space-charge potentials and bulk diffusion coefficients are analysed as a function of oxygen partial pressure and temperature. The data

  9. Embryo apoptosis identification: Oocyte grade or cleavage stage?

    Science.gov (United States)

    Bakri, Noraina Mohd; Ibrahim, Siti Fatimah; Osman, Nurul Atikah; Hasan, Nurhaslina; Jaffar, Farah Hanan Fathihah; Rahman, Zulaiha Abdul; Osman, Khairul

    2015-01-01

    Apoptosis is a programed cell death that is vital for tissue homeostasis. However, embryo apoptosis had been known to be related to embryo fragmentation which should be avoided in in vitro fertilization (IVF). The purpose of this study was to evaluate the relationship of embryo apoptosis with the grade of immature oocytes and cleavage stage of in vitro produced (IVP) cattle embryos. This study consisted of 345 oocytes collected through ovary slicing. Immature oocytes were graded as A, B and C. This grading was based on cumulus cell thickness and compactness. All oocytes then underwent an in vitro maturation (IVM) procedure. An IVF was done 24 h after IVM culture. Prior to staining, stage of cleaved embryos was determined and classified as either 2, 4, 8 or >8-cell embryo stage. Apoptosis status of cleaved IVP embryos was determined by using annexin V-FITC staining technique at 48 and 72 h post insemination (hpi). Apoptosis status for each embryo was classified as either early or late. The result showed that there was no significant difference (p > 0.05) of apoptosis status among grade A, B and C embryos. All grades of oocytes showed embryo apoptosis where 1.5% late apoptosis for grade A, 4.5% and 10.4% of early and late apoptosis for grade B and grade C. Early apoptosis was not seen in grade A embryo. We also noted no significant difference (p > 0.05) of apoptosis status between 2, 4, 8 and >8-cell embryo stage. Early apoptosis was also not seen in >8-cell stage. Even though there were no differences in apoptosis expression between the three classes, the cleavage rate of grade A oocytes was significantly higher (p < 0.01) than grade B and grade C. In conclusion, the apoptosis expression in the embryo can occur regardless of the oocyte quality and the cleavage stage of the embryo produced. PMID:26858565

  10. Relationship between osteocyte apoptosis and orbital bone development in rabbits

    Institute of Scientific and Technical Information of China (English)

    MA Jian-min; LI Zhi-hui

    2004-01-01

    Objective To investigate whether the osteocyte apoptosis exists in orbital bones and to discuss its effect on the orbital development.Methods Seven young Newzealand white rabbits were selected as experimental animals.At two-month-old ,all rabbits were killed and then zygomas were made into paraffin and electron microscope sections after they were decalcified.Apoptosis of osteocytes was observed by light microscope and transmission electron microscopes and detected by TUNEL staining.Results The classical apoptosis of osteocytes was found under light and transmission electron microscopes.Apoptosis of osteocytes was diffused irregularly in the zygomatic tissue. Conclusion Osteocyte can apoptosis and it may participate in the development of the bony orbit.

  11. Apoptosis in skeletal muscle and its relevance to atrophy

    Institute of Scientific and Technical Information of China (English)

    Esther E Dupont-Versteegden

    2006-01-01

    Apoptosis is necessary for maintaining the integrity of proliferative tissues, such as epithelial cells of the gastrointestinal system. The role of apoptosis in post mitotic tissues, such as skeletal muscle, is less well defined. Apoptosis during muscle atrophy occurs in both myonuclei and other muscle cell types. Apoptosis of myonuclei likely contributes to the loss of muscle mass, but the mechanisms underlying this process are largely unknown. Caspase-dependent as well as -independent pathways have been implicated and the mode by which atrophy is induced likely determines the apoptotic mechanisms that are utilized. It remains to be determined whether a decrease in apoptosis will alleviate atrophy and distinct research strategies may be required for different causes of skeletal muscle loss.

  12. [GPI-Pr Deficiency and Apoptosis of PNH Granulocytes

    Science.gov (United States)

    Liu, Hai-Li; Xu, Cai-Min; Liu, Fu-Qiang; Lu, Zhao-Jiang; Pan, Hua-Zhen; Zhang, Zhi-Nan

    2001-09-01

    To study the relationship of Glycosyl phosphatidylinositol anchored proteins (GIP-Pr) and apoptosis of paroxysmal nocturnal hemoglobinuria (PNH) cells, we isolated peripheral granulocytes from 10 patients with PNH and 10 normal controls and measured apoptosis induced by serum starvation. The FCM analysis of phosphotidylserine (ps) externalization in granulocytes was determined using Annexin-V-FLUOS labeling. After the cells were induced for apoptosis in serum-free medium for 20 hours, the percentage of externalization was 78.6% in normal control cells but 39.5% in PNH cells. The results of FCM analysis of PI stained granulocytes showed that the PI positive rate was 51.5% in control cells and 30.2% in PNH cells. The gel electrophoresis analysis of DNA fragmentation all indicate that PNH granulocytes were relatively resistant to apoptosis as compared with normal controls. This resistance to apoptosis might not be related to the percentage of CD59 deficient granulocytes. PMID:12578597

  13. Apoptosis of Cancer Cells Induced by HAP Nanoparticles

    Institute of Scientific and Technical Information of China (English)

    HU Sheng; LI Shipu; YAN Yuhua; WANG Youfa; CAO Xianying

    2005-01-01

    To confirm apoptosis is one of the hepatoma cells death pathways after HAP nanoparticles absorption, hepatoma cells were collected for ultrathin sections preparation and examined under a transmission electron microscope (TEM) after 1 h incubation with HAP nanoparticle. Apoptosis was detected by TUNEL technique. After absorption, some vacuoles with membrane containing HAP nanoparticles were found in cytoplasma.The nuclear envelope shrinked, and some area pullulated from nucleus. The karyotin became pycnosis and assembled at the edge. An apoptosis body was found. And the data of IOD and numbers of the positive apoptosic signals in nuclear area of slides could illustrate much more apoptosis in the HAP group than those in the control group ( P < 0.001 ). The experimental results indicate that the HAP nanoparticles can induce cancer cells apoptosis.

  14. Holographic Grating Formation in Cationic Photopolymers with Dark Reaction

    Institute of Scientific and Technical Information of China (English)

    WEI Hao-Yun; CAO Liang-Cai; GU Claire; XU Zhen-Feng; HE Ming-Zhao; HE Qing-Sheng; HE Shu-Rong; JIN Guo-Fan

    2006-01-01

    @@ We propose a new formula to describe the dynamics of holographic grating formation under low intensity pulse exposures in cationic photopolymers, in which the dark reaction contributes dominantly to the grating strength.The formula is based on the living polymerization mechanism and the diffusion-free approximation. The analytical solution indicates that the grating formation time depends on the termination rate constant, while the final grating strength depends linearly on the total exposure energy. These theoretical predictions are verified experimentally using the Aprilis HMC-400μm photopolymer. The results can provide guidelines for the control and optimization of the holographic recording conditions in practical applications.

  15. Stretch-activated cation channel from larval bullfrog skin

    OpenAIRE

    Hillyard, Stanley D.; Willumsen, Niels J.; Marrero, Mario B.

    2010-01-01

    Cell-attached patches from isolated epithelial cells from larval bullfrog skin revealed a cation channel that was activated by applying suction (−1 kPa to −4.5 kPa) to the pipette. Activation was characterized by an initial large current spike that rapidly attenuated to a stable value and showed a variable pattern of opening and closing with continuing suction. Current–voltage plots demonstrated linear or inward rectification and single channel conductances of 44–56 pS with NaCl or KCl Ringer...

  16. Extracytoplasmic Stress Responses Induced by Antimicrobial Cationic Polyethylenimines

    OpenAIRE

    Lander, Blaine A.; Checchi, Kyle D.; Koplin, Stephen A.; Smith, Virginia F.; Domanski, Tammy L.; Isaac, Daniel D.; Lin, Shirley

    2012-01-01

    The ability of an antimicrobial, cationic polyethylenimine (PEI+) to induce the three known extracytoplasmic stress responses of Escherichia coli was quantified. Exposure of E. coli to PEI+ in solution revealed specific, concentration-dependent induction of the Cpx extracytoplasmic cellular stress response, ~2.0-2.5 fold at 320 μg/mL after 1.5 hours without significant induction of the σE or Bae stress responses. In comparison, exposure of E. coli to a non-antimicrobial polymer, polyethylene ...

  17. Incorporation of Monovalent Cations in Sulfate Green Rust

    DEFF Research Database (Denmark)

    Christiansen, B. C.; Dideriksen, K.; Katz, A.;

    2014-01-01

    Green rust is a naturally occurring layered mixed-valent ferrous-ferric hydroxide, which can react with a range of redox-active compounds. Sulfate-bearing green rust is generally thought to have interlayers composed of sulfate and water. Here, we provide evidence that the interlayers also contain...... with water showed that Na+ and K+ were structurally fixed in the interlayer, whereas Rb+ and Cs+ could be removed, resulting in a decrease in the basal layer spacing. The incorporation of cations in the interlayer opens up new possibilities for the use of sulfate green rust for exchange reactions with both...

  18. Spontaneous Superlattice Formation in Nanorods through PartialCation Exchange

    Energy Technology Data Exchange (ETDEWEB)

    Robinson, Richard D.; Sadtler, Bryce; Demchenko, Denis O.; Erdonmez, Can K.; Wang, Lin-Wang; Alivisatos, A. Paul

    2007-03-14

    Lattice mismatch strains are widely known to controlnanoscale pattern formation in heteroepitaxy, but such effects have notbeen exploited in colloidal nanocrystal growth. We demonstrate acolloidal route to synthesizing CdS-Ag2S nanorod superlattices throughpartial cation exchange. Strain induces the spontaneous formation ofperiodic structures. Ab initio calculations of the interfacial energy andmodeling of strain energies show that these forces drive theself-organization. The nanorod superlattices exhibit high stabilityagainst ripening and phase mixing. These materials are tunablenear-infrared emitters with potential applications as nanometer-scaleoptoelectronic devices.

  19. Spectroscopy and interactions of metal and metal cation complexes

    OpenAIRE

    Plowright, Richard J.

    2010-01-01

    The work in this thesis looks at the spectroscopy and interactions of metals and metal cation complexes. There are two aspects of this vast subject that are considered: the electronic spectroscopy of Au-RG complexes and the ion-molecule chemistry of metals important in the mesosphere-lower thermosphere (MLT) region of the atmosphere. The spectroscopy of the molecular states in the vicinity of the strong Au 2P3/2, 1/2 ← 2S1/2 atomic transition, have been studied for the Au-RG (RG = Ne, Ar...

  20. Blackbody-induced radiative dissociation of cationic SF 6 clusters

    DEFF Research Database (Denmark)

    Toker, Jonathan; Rahinov, I.; Schwalm, D.;

    2012-01-01

    The stability of cationic SF5+(SF6)n−1 clusters was investigated by measuring their blackbody-induced radiative dissociation (BIRD) rates. The clusters were produced in a supersonic expansion ion source and stored in an electrostatic ion-beam trap at room temperature, where their abundances...... and lifetimes were measured. Using the “master equation” approach, relative binding energies of an SF6 unit in the clusters could be extracted from the storage-time dependence of the survival probabilities. The results allow for a deeper insight into the effect of a localized charge on the structure...... and stability of SF6-based clusters....

  1. Synthesis of Branch Fluorinated Cationic Surfactant and Surface Properties

    Directory of Open Access Journals (Sweden)

    Hongke Wu

    2014-01-01

    Full Text Available A novel fluorinated quaternary ammonium salt cationic surfactant N,N,N-trimethyl-2-[[4-[[3,4,4,4-tetrafluoro-2-[1,2,2,2-tetrafluoro-1-(trifluoromethylethyl]-1,3-bis(tri-fluoromethyl-1-buten-1-yl]oxy]-benzoyl]amino]-iodide (FQAS was synthesized successfully, and its structure was characterized by FTIR, 1H-NMR, 19F-NMR, and MS. The surface activities of FQAS and the effect of temperature, electrolyte, and combination with hydrocarbon surfactant were investigated. The results showed that FQAS exhibited excellent surface activity and combination with hydrocarbon surfactant.

  2. Gas-phase folding and unfolding of cytochrome c cations.

    OpenAIRE

    Wood, T D; Chorush, R A; Wampler, F M; Little, D P; O'Connor, P B; McLafferty, F. W.

    1995-01-01

    Water is thought to play a dominant role in protein folding, yet gaseous multiply protonated proteins from which the water has been completely removed show hydrogen/deuterium (H/D) exchange behavior similar to that used to identify conformations in solution. Indicative of the gas-phase accessibility to D2O, multiply-charged (6+ to 17+) cytochrome c cations exchange at six (or more) distinct levels of 64 to 173 out of 198 exchangeable H atoms, with the 132 H level found at charge values 8+ to ...

  3. A NEW METHOD TO SYNTHESIZE THE CATIONIC GRAFT STARCH

    Institute of Scientific and Technical Information of China (English)

    Lin Li; Bingyue Liu; Yafeng Cao

    2004-01-01

    The cationic graft copolymer was synthesized by reversed phase emulsion copolymerization of starch with diallydimethyl ammoniumlchlorid (DADMAC)and acrylamide (AM). The copolymerization was carried out using (NH4)2S2O8-NH2CONH2 redox as initiator and selecting Span-20 as emulsifier. The effects of emulsifier content in oil phase, volume ratio of oil to water, initiator concentration and mole ratio of DADMAC to AM on the graft copolymerization were discussed. The optimum condition of synthetics was found with the orthogonal test method.

  4. Searching for Naphthalene Cation Absorption in the Interstellar Medium

    Science.gov (United States)

    Searles, Justin M.; Destree, Joshua D.; Snow, Theodore P.; Salama, Farid; York, Donald G.; Dahlstrom, Julie

    2011-05-01

    Interstellar naphthalene cations (C10H+ 8) have been proposed by a study to be the carriers of a small number of diffuse interstellar bands (DIBs). Using an archive of high signal-to-noise spectra obtained at the Apache Point Observatory, we used two methods to test the hypothesis. Both methods failed to detect significant absorption at lab wavelengths of interstellar spectra with laboratory spectra. We thereby conclude that C10H+ 8 is not a DIB carrier in typical reddened sight lines.

  5. SEARCHING FOR NAPHTHALENE CATION ABSORPTION IN THE INTERSTELLAR MEDIUM

    International Nuclear Information System (INIS)

    Interstellar naphthalene cations (C10H+8) have been proposed by a study to be the carriers of a small number of diffuse interstellar bands (DIBs). Using an archive of high signal-to-noise spectra obtained at the Apache Point Observatory, we used two methods to test the hypothesis. Both methods failed to detect significant absorption at lab wavelengths of interstellar spectra with laboratory spectra. We thereby conclude that C10H+8 is not a DIB carrier in typical reddened sight lines.

  6. Protic Cationic Oligomeric Ionic Liquids of the Urethane Type

    DEFF Research Database (Denmark)

    Shevchenko, V. V.; Stryutsky, A. V.; Klymenko, N. S.;

    2014-01-01

    Protic oligomeric cationic ionic liquids of the oligo(ether urethane) type are synthesized via the reaction of an isocyanate prepolymer based on oligo(oxy ethylene)glycol with M = 1000 with hexamethylene-diisocyanate followed by blocking of the terminal isocyanate groups with the use of amine...... derivatives of imidazole, pyridine, and 3-methylpyridine and neutralization of heterocycles with ethanesulfonic acid and p-toluenesulfonic acid. The structures and properties of the synthesized oligomeric ionic liquids substantially depend on the structures of the ionic groups. They are amorphous at room...

  7. Temperature-controlled interaction of thermosensitive polymer-modified cationic liposomes with negatively charged phospholipid membranes.

    Science.gov (United States)

    Kono, K; Henmi, A; Takagishi, T

    1999-09-21

    To obtain cationic liposomes of which affinity to negatively charged membranes can be controlled by temperature, cationic liposomes consisting of 3beta-[N-(N', N'-dimethylaminoethane)carbamoyl]cholesterol and dioleoylphosphatidylethanolamine were modified with poly(N-acryloylpyrrolidine), which is a thermosensitive polymer exhibiting a lower critical solution temperature (LCST) at ca. 52 degrees C. The unmodified cationic liposomes did not change its zeta potential between 20-60 degrees C. The polymer-modified cationic liposomes revealed much lower zeta potential values below the LCST of the polymer than the unmodified cationic liposomes. However, their zeta potential increased significantly above this temperature. The unmodified cationic liposomes formed aggregates and fused intensively with anionic liposomes consisting of egg yolk phosphatidylcholine and phosphatidic acid in the region of 20-60 degrees C, due to the electrostatic interaction. In contrast, aggregation and fusion of the polymer-modified cationic liposomes with the anionic liposomes were strongly suppressed below the LCST. However, these interactions were enhanced remarkably above the LCST. In addition, the polymer-modified cationic liposomes did not cause leakage of calcein from the anionic liposomes below the LCST, but promoted the leakage above this temperature as the unmodified cationic liposomes did. Temperature-induced conformational change of the polymer chains from a hydrated coil to a dehydrated globule might affect the affinity of the polymer-modified cationic liposomes to the anionic liposomes. PMID:10561483

  8. Cytotoxic activity and apoptosis induction by gaillardin.

    Science.gov (United States)

    Moghadam, Maryam Hamzeloo; Naghibi, Farzaneh; Atoofi, Azadeh; Rezaie, Mitra Asgharian; Irani, Mahboobeh; Mosaddegh, Mahmoud

    2013-01-01

    Cytotoxic activity of gaillardin, a sesquiterpene lactone isolated from Inula oculus-christi L. (Asteraceae), was assessed in the human breast adenocarcinoma cell line MCF-7, human hepatocellular carcinoma cell line HepG-2, human non-small cell lung carcinoma cell line A-549, and human colon adenocarcinoma cell line HT-29, resulting in IC50 values of 6.37, 6.20, 4.76, and 1.81 microg/mL, respectively, in the microculture tetrazolium-formazan MTT assay. In vitro apoptosis-inducing properties of gaillardin were also evaluated in MCF-7 cells with the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling (TUNEL) assay. The results suggest gaillardin as a candidate for further studies in cancer therapy PMID:23819305

  9. Insect cells are superior to Escherichia coli in producing malaria proteins inducing IgG targeting PfEMP1 on infected erythrocytes

    Directory of Open Access Journals (Sweden)

    Joergensen Louise

    2010-11-01

    Full Text Available Abstract Background The PFD1235w Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1 antigen is associated with severe malaria in children and can be expressed on the surface of infected erythrocytes (IE adhering to ICAM1. However, the exact three-dimensional structure of this PfEMP1 and its surface-exposed epitopes are unknown. An insect cell and Escherichia coli based system was used to express single and double domains encoded by the pfd1235w var gene. The resulting recombinant proteins have been evaluated for yield and purity and their ability to induce rat antibodies, which react with the native PFD1235w PfEMP1 antigen expressed on 3D7PFD1235w-IE. Their recognition by human anti-malaria antibodies from previously infected Tanzanian donors was also analysed. Methods The recombinant proteins were run on SDS-PAGE and Western blots for quantification and size estimation. Insect cell and E. coli-produced recombinant proteins were coupled to a bead-based Luminex assay to measure the plasma antibody reactivity of 180 samples collected from Tanzanian individuals. The recombinant proteins used for immunization of rats and antisera were also tested by flow cytometry for their ability to surface label 3D7PFD1235w-IE. Results All seven pAcGP67A constructs were successfully expressed as recombinant protein in baculovirus-infected insect cells and subsequently produced to a purity of 60-97% and a yield of 2-15 mg/L. By comparison, only three of seven pET101/D-TOPO constructs expressed in the E. coli system could be produced at all with purity and yield ranging from 3-95% and 6-11 mg/L. All seven insect cell, but only two of the E. coli produced proteins induced antibodies reactive with native PFD1235w expressed on 3D7PFD1235w-IE. The recombinant proteins were recognized in an age- and transmission intensity-dependent manner by antibodies from 180 Tanzanian individuals in a bead-based Luminex assay. Conclusions The baculovirus based insect cell

  10. Cation charge dependence of the forces driving DNA assembly.

    Science.gov (United States)

    DeRouchey, Jason; Parsegian, V Adrian; Rau, Donald C

    2010-10-20

    Understanding the strength and specificity of interactions among biologically important macromolecules that control cellular functions requires quantitative knowledge of intermolecular forces. Controlled DNA condensation and assembly are particularly critical for biology, with separate repulsive and attractive intermolecular forces determining the extent of DNA compaction. How these forces depend on the charge of the condensing ion has not been determined, but such knowledge is fundamental for understanding the basis of DNA-DNA interactions. Here, we measure DNA force-distance curves for a homologous set of arginine peptides. All forces are well fit as the sum of two exponentials with 2.4- and 4.8-Å decay lengths. The shorter-decay-length force is always repulsive, with an amplitude that varies slightly with length or charge. The longer-decay-length force varies strongly with cation charge, changing from repulsion with Arg¹ to attraction with Arg². Force curves for a series of homologous polyamines and the heterogeneous protein protamine are quite similar, demonstrating the universality of these forces for DNA assembly. Repulsive amplitudes of the shorter-decay-length force are species-dependent but nearly independent of charge within each species. A striking observation was that the attractive force amplitudes for all samples collapse to a single curve, varying linearly with the inverse of the cation charge. PMID:20959102

  11. Nitrogen-doped zirconia: A comparison with cation stabilized zirconia

    International Nuclear Information System (INIS)

    The conductivity behavior of nitrogen-doped zirconia is compared with that of zirconia doped with lower-valent cations and discussed in the framework of defect-defect interactions. While nominally introducing the same number of vacancies as yttrium, nitrogen dopants introduced in the anion sublattice of zirconia lead to substantially different defect kinetics and energetics. Compared to the equivalent yttrium doping nitrogen doping in the Y-Zr-O-N system substantially increases the activation energy and correspondingly decreases the conductivity at temperatures below 500-bar C in the vacancy range below 4mol%. The comparison of N-doped zirconia and zirconia systems doped with size-matched cation stabilizers, such as Sc, Yb and Y, shows that elastically driven vacancy-vacancy ordering interactions can phenomenologically account for the temperature- and composition-dependence. It is striking that materials with superior high-temperature conductivities due to weak dopant-vacancy interactions undergo severe deterioration at low temperature due to the strong vacancy-ordering. The analysis also explains qualitatively similar effects of Y co-doping in Yb-, Sc-, and N-doped zirconia. Small amount of Y in N-doped zirconia as well as in Sc-doped zirconia appears to hinder the formation of the long-range ordered phase and thus enhance the conductivity substantially

  12. Cationic zinc organyls as precatalysts for hydroamination reactions.

    Science.gov (United States)

    Chilleck, Maren A; Hartenstein, Larissa; Braun, Thomas; Roesky, Peter W; Braun, Beatrice

    2015-02-01

    The cationic zinc triple-decker complex [Zn2 Cp*3 ](+) [BAr(F) 4 ](-) (BAr(F) 4 =B(3,5-(CF3 )2 C6 H3 )4 ) exhibits catalytic activity in intra- and intermolecular hydroamination reactions in the absence of a cocatalyst. These hydroaminations presumably proceed through the activation of the C-C multiple bond of the alkene or alkyne by a highly electrophilic zinc species, which is formed upon elimination of the Cp* ligands. The reaction of [Zn2 Cp*3 ](+) [BAr(F) 4 ](-) with henylacetylene gives the hydrocarbonation product (Cp*)(Ph)CCH2 , which might be formed via a similar reaction pathway. Additionally, several other structurally well-defined cationic zinc organyls have been examined as precatalysts for intermolecular hydroamination reactions without the addition of a cocatalyst. These studies reveal that the highest activity is achieved in the absence of any donor ligands. The neutral complex [ZnCp(2S) 2 ] (Cp(2S) =C5 Me4 (CH2 )2 SMe) shows a remarkably high catalytic activity in the presence of a Brønsted acid. PMID:25522205

  13. Metal cations inserted in vanadium-oxide nanotubes

    International Nuclear Information System (INIS)

    Vanadium-oxide nanotubes (VO x-NTs) consist of nanosize cylinders of thin, easily bent vanadyl (VO x) wall chains, which are open at both ends. Surfactant molecules (e.g. C12H27N) can be easily trapped in the interior of the nanotube walls. The structure of as-synthesized VO x-NTs are observed to collapse to an amorphous vanadium oxide at temperatures greater than 250 deg, C. This happens, even under a protective atmosphere. This property makes the VO x-NTs unusable as a catalyst at temperatures between 400-500 deg, C, which is the temperature range where many applications would exist. In order to increase the thermal stability of VO x-NTs several exchange reactions have been used to modify the original nanotubes. In these reactions metallic cations (Cd2+, Co2+, Mn2+ or Zn2+) were introduced. It was observed that that the morphology of the nanotubes remained unchanged after the exchange reactions were performed. In order to characterize the exchanged VO x-NTs the following analytic techniques were used: scanning electron microscopy, X-ray powder diffraction, Fourier transform infrared, particle-induced X-ray emission and Rutherford backscattering spectrometry. The results showed that the VO x-NTs exchanged with metallic cations have preserved their tubular morphology. However, it has not been possible to fully perform a 100% efficient exchange reaction

  14. Cationic Nanocylinders Promote Angiogenic Activities of Endothelial Cells

    Directory of Open Access Journals (Sweden)

    Jung Bok Lee

    2016-01-01

    Full Text Available Polymers have been used extensively taking forms as scaffolds, patterned surface and nanoparticle for regenerative medicine applications. Angiogenesis is an essential process for successful tissue regeneration, and endothelial cell–cell interaction plays a pivotal role in regulating their tight junction formation, a hallmark of angiogenesis. Though continuous progress has been made, strategies to promote angiogenesis still rely on small molecule delivery or nuanced scaffold fabrication. As such, the recent paradigm shift from top-down to bottom-up approaches in tissue engineering necessitates development of polymer-based modular engineering tools to control angiogenesis. Here, we developed cationic nanocylinders (NCs as inducers of cell–cell interaction and investigated their effect on angiogenic activities of human umbilical vein endothelial cells (HUVECs in vitro. Electrospun poly (l-lactic acid (PLLA fibers were aminolyzed to generate positively charged NCs. The aninolyzation time was changed to produce two different aspect ratios of NCs. When HUVECs were treated with NCs, the electrostatic interaction of cationic NCs with negatively charged plasma membranes promoted migration, permeability and tubulogenesis of HUVECs compared to no treatment. This effect was more profound when the higher aspect ratio NC was used. The results indicate these NCs can be used as a new tool for the bottom-up approach to promote angiogenesis.

  15. Cationic gadolinium chelate for magnetic resonance imaging of cartilaginous defects.

    Science.gov (United States)

    Nwe, Kido; Huang, Ching-Hui; Qu, Feini; Warden-Rothman, Robert; Zhang, Clare Y; Mauck, Robert L; Tsourkas, Andrew

    2016-05-01

    The ability to detect meniscus defects by magnetic resonance arthrography (MRA) can be highly variable. To improve the delineation of fine tears, we synthesized a cationic gadolinium complex, (Gd-DOTA-AM4 )(2+) , that can electrostatically interact with Glycosaminoglycans (GAGs). The complex has a longitudinal relaxivity (r1) of 4.2 mM(-1) s(-1) and is highly stable in serum. Its efficacy in highlighting soft tissue tears was evaluated in comparison to a clinically employed contrast agent (Magnevist) using explants obtained from adult bovine menisci. In all cases, Gd-DOTA-AM4 appeared to improve the ability to detect the soft tissue defect by providing increased signal intensity along the length of the tear. Magnevist shows a strong signal near the liquid-meniscus interface, but much less contrast is observed within the defect at greater depths. This provides initial evidence that cationic contrast agents can be used to improve the diagnostic accuracy of MRA. Copyright © 2016 John Wiley & Sons, Ltd.

  16. High and rapid alkali cation storage in ultramicroporous carbonaceous materials

    Science.gov (United States)

    Yun, Young Soo; Lee, Seulbee; Kim, Na Rae; Kang, Minjee; Leal, Cecilia; Park, Kyu-Young; Kang, Kisuk; Jin, Hyoung-Joon

    2016-05-01

    To achieve better supercapacitor performance, efforts have focused on increasing the specific surface area of electrode materials to obtain higher energy and power density. The control of pores in these materials is one of the most effective ways to increase the surface area. However, when the size of pores decreases to a sub-nanometer regime, it becomes difficult to apply the conventional parallel-plate capacitor model because the charge separation distance (d-value) of the electrical double layer has a similar length scale. In this study, ultramicroporous carbonaceous materials (UCMs) containing sub-nanometer-scale pores are fabricated using a simple in situ carbonization/activation of cellulose-based compounds containing potassium. The results show that alkali cations act as charge carriers in the ultramicropores (<0.7 nm), and these materials can deliver high capacitances of ∼300 F g-1 at 0.5 A g-1 and 130 F g-1, even at a high current rate of 65 A g-1 in an aqueous medium. In addition, the UCM-based symmetric supercapacitors are stable over 10,000 cycles and have a high energy and power densities of 8.4 Wh kg-1 and 15,000 W kg-1, respectively. This study provides a better understanding of the effects of ultramicropores in alkali cation storage.

  17. Cation distribution and magnetic properties of natural chromites

    Energy Technology Data Exchange (ETDEWEB)

    Rais, A.; Yousif, A.A.; Al-shihi, M.H.; Al-rawas, A.D.; Gismelseed, A.M.; El-zain, M.E. [Department of Physics, College of Science, Sultan Qaboos University (Oman)

    2003-10-01

    Ten specimens of chromites from Oman ophiolites have been studied using magnetic susceptibility {chi} measurements, Moessbauer spectroscopy (MS), Scanning electron microscopy (SEM), and X-ray diffraction (XRD). XRD shows that all samples have a face-centered cubic spinel structure. MS analysis and SEM data at room temperature enabled to derive the chemical formula and the cations distribution among tetrahedral (A1 and A2) and octahedral (B) sites. For all specimens, paramagnetic variations of 1/{chi} with the temperature T show a systematic curve bending at a critical temperature T{sub 0}, which indicates a change of the effective paramagnetic moment {mu}{sub eff}. This deviation from Curie-Weiss law is interpreted as due to spin inversion of a fraction {delta} of Cr{sup 3+} cations located in the octahedral sites of the spinel structure. This interpretation is supported by a decrease in the Moessbauer peak areas of Fe{sup 2+} located in A1 sites from 300 to 80 K at the expense of Fe{sup 2+} located in A2 sites. The values of {delta} and {mu}{sub eff} for each specimen are calculated by fitting this model separately to the experimental 1/{chi} versus T above and below T{sub 0}. (Abstract Copyright [2003], Wiley Periodicals, Inc.)

  18. Cationic Polyene Phospholipids as DNA Carriers for Ocular Gene Therapy

    Directory of Open Access Journals (Sweden)

    Susana Machado

    2014-01-01

    Full Text Available Recent success in the treatment of congenital blindness demonstrates the potential of ocular gene therapy as a therapeutic approach. The eye is a good target due to its small size, minimal diffusion of therapeutic agent to the systemic circulation, and low immune and inflammatory responses. Currently, most approaches are based on viral vectors, but efforts continue towards the synthesis and evaluation of new nonviral carriers to improve nucleic acid delivery. Our objective is to evaluate the efficiency of novel cationic retinoic and carotenoic glycol phospholipids, designated C20-18, C20-20, and C30-20, to deliver DNA to human retinal pigmented epithelium (RPE cells. Liposomes were produced by solvent evaporation of ethanolic mixtures of the polyene compounds and coformulated with 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE or cholesterol (Chol. Addition of DNA to the liposomes formed lipoplexes, which were characterized for binding, size, biocompatibility, and transgene efficiency. Lipoplex formulations of suitable size and biocompatibility were assayed for DNA delivery, both qualitatively and quantitatively, using RPE cells and a GFP-encoding plasmid. The retinoic lipoplex formulation with DOPE revealed a transfection efficiency comparable to the known lipid references 3β-[N-(N′,N′-dimethylaminoethane-carbamoyl]-cholesterol (DC-Chol and 1,2-dioleoyl-sn-glycero-3-ethylphosphocholine (EPC and GeneJuice. The results demonstrate that cationic polyene phospholipids have potential as DNA carriers for ocular gene therapy.

  19. Dendrisomes: vesicular structures derived from a cationic lipidic dendron.

    Science.gov (United States)

    Al-Jamal, Khuloud T; Sakthivel, Thiagarajan; Florence, Alexander T

    2005-01-01

    The behavior of a novel synthetic lipidic cationic lysine-based dendron (partial dendrimer) in aqueous media and its ability, with and without cholesterol, to self-assemble into higher order structures was studied to gain an understanding of these structures as potential drug carriers. The dendron was prepared by solid-phase peptide synthesis. A reverse-phase evaporation (REV) technique was used to prepare cationic vesicular aggregates of the dendron with different molar ratios of cholesterol. The size and zeta potential of these supramolecular aggregates or "dendrisomes" was determined by photon correlation spectroscopy (PCS). Dendrisome morphology and thermotropic properties were studied by transmission electron microscopy (TEM) and differential scanning calorimetry (DSC). Radiolabeled penicillin G was used as a model of a negatively charged water-soluble compound to investigate the encapsulation efficiency of the dendrisomes. In vitro release of the drug was determined using as a comparator a REV liposome formulation. Dendrisomes of all compositions have higher encapsulation efficiencies and slower release rates compared to the comparator. Cholesterol was found both to increase the size of the aggregates from around 310 to 560 nm and to increase shape irregularities, but did not change the positive zeta potential, in the order of +50 mV, of the dendrisomes. Cholesterol decreases penicillin G entrapment efficiency but increases solute leakage at 25 degrees C. PMID:15761934

  20. Source of Lake Vostok Cations Constrained with Strontium Isotopes

    Science.gov (United States)

    Lyons, William; Welch, Kathleen; Priscu, John; Tranter, Martyn; Royston-Bishop, George

    2016-08-01

    Lake Vostok is the largest sub-glacial lake in Antarctica. The primary source of our current knowledge regarding the geochemistry and biology of the lake comes from the analysis of refrozen lake water associated with ice core drilling. Several sources of dissolved ions and particulate matter to the lake have been proposed, including materials from the melted glacier ice, the weathering of underlying geological materials, hydrothermal activity and underlying, ancient evaporitic deposits. A sample of Lake Vostok Type 1 accretion ice has been analyzed for its 87Sr/86Sr signature as well as its major cation and anion and Sr concentrations. The strontium isotope ratio of 0.71655 and the Ca/Sr ratio in the sample strongly indicate that the major source of the Sr is from aluminosilicate minerals from the continental crust. These data imply that at least a portion of the other cations in the Type 1 ice also are derived from continental crustal materials and not hydrothermal activity, the melted glacier ice, or evaporitic sources.

  1. Diffusion of anions and cations in compacted sodium bentonite

    International Nuclear Information System (INIS)

    The thesis presents the results of studies on the diffusion mechanisms of anions and cations in compacted sodium bentonite, which is planned to be used as a buffer material in nuclear waste disposal in Finland. The diffusivities and sorption factors were determined by tracer experiments. The pore volume accessible to chloride, here defined as effective porosity, was determined as a function of bentonite density and electrolyte concentration in water, and the Stern-Gouy double-layer model was used to explain the observed anion exclusion. The sorption of Cs+ and Sr2+ was studied in loose and compacted bentonite samples as a function of the electrolyte concentration in solution. In order to obtain evidence of the diffusion of exchangeable cations, defined as surface diffusion, the diffusivities of Cs+ and Sr2+ in compacted bentonite were studied as a function of the sorption factor, which was varied by electrolyte concentration in solution. The measurements were performed both by a non-steady state method and by a through-diffusion method. (89 refs., 35 fig., 4 tab.)

  2. Lethal bacterial trap: Cationic surface for endodontic sealing.

    Science.gov (United States)

    Kesler Shvero, Dana; Zaltsman, Nathan; Weiss, Ervin I; Polak, David; Hazan, Ronen; Beyth, Nurit

    2016-02-01

    Insoluble antibacterial cationic nanoparticles have been previously shown to have potent and long-lasting antibacterial properties. Our tested hypothesis was that root canal pathogens will be attracted to and eliminated when exposed to epoxy resin-based surfaces incorporating cationic nanoparticles. In our research, an epoxy resin-based surface incorporating quaternary ammonium polyethyleneimine (QPEI) nanoparticles was evaluated. Surface characterization was performed using atomic force microscopy and X-ray photoelectron spectra. The surface anti-Enterococcus faecalis effect was evaluated in an anti-gravitational model. Cell membrane potential, viability, biofilm thickness, and biomass were tested using flow cytometry and confocal laser scanning microscopy. Additionally, the antibiofilm activity of the bacterial supernatant was assessed. The surface characterization showed QPEI nanoparticle embedment on the modified sealer. The epoxy resin-based surface incorporating the QPEI nanoparticles actively attracted bacteria, causing membrane destabilization, and bacterial death. The supernatant of bacteria pre-exposed to QPEI showed an antibacterial effect. In conclusion, the tested epoxy resin-based surface incorporating QPEI nanoparticles traps and kills bacteria. The nanoparticles attracted bacteria, reducing their viability, and promoting cell death. PMID:26418438

  3. Influence of a cationic polysaccharide on starch functionality.

    Science.gov (United States)

    Raguzzoni, Josiane C; Delgadillo, Ivonne; Lopes da Silva, José A

    2016-10-01

    Fundamental rheology, differential scanning calorimetry and infrared spectroscopy have been used to evaluate the effect of a cationic polysaccharide, chitosan, on the gelatinization, gel formation and retrogradation of maize starch samples, under acidic aqueous conditions. Moderate acidic conditions (0.1molL(-1) acetic acid) have shown a (slight) positive effect on starch gelatinization process and structure development. The presence of chitosan increased the DSC onset gelatinization temperature and also shifted the onset of the storage modulus increase to higher temperatures. Formation of the starch gel, mainly gelation of the leached-out amylose, is somehow hindered by the presence of the cationic polysaccharide and, therefore, the retrogradation of starch at very early stage can be delayed by addition of chitosan. However, long-term retrogradation was slightly increased. FTIR pectroscopy did not reveal any significant interaction between both polysaccharides what is in accordance with the observed rheological behavior. Small additions of chitosan to starch-rich systems may be a useful strategy to obtain new textures with novel phase transition behaviors. PMID:27312647

  4. USING COLLOIDAL LAYERED DOUBLE HYDROXIDES AS CATIONIC MICROPARTICULATE COMPONENT

    Institute of Scientific and Technical Information of China (English)

    Songlin Wang; Wenxia Liu

    2004-01-01

    Layered double hydroxides consisting of layers with cationic charges may be potential candidates of cationic microparticles forming synergetic retention effect with anionic polyacrylamide. In this work, the layered double hydroxides with various molar ratios of Mg/Al were synthesized by co-precipitation of magnesium chloride and aluminum chloride and peptized by intense washing with water. The chemical formula, particle size, Zeta potential of the layered double hydroxide were analyzed. It was found that positively charged magnesium aluminum hydroxide with particle diameter in nanoparticle size could be prepared. The Zeta potential and particle size vary with the feed molar ratio of Mg/Al and the peptizing process, respectively. The Zeta potential is also pH dependent. The retention experiments carried out on DDJ show that when used together with anionic polyacrylamide, the positively charged colloidal double hydroxide greatly improves the retention of reed pulps. The chemical formula, particle size and Zeta potential of the colloidal double hydroxide all affect its retention behavior.

  5. Role of Reverse Divalent Cation Diffusion in Forward Osmosis Biofouling.

    Science.gov (United States)

    Xie, Ming; Bar-Zeev, Edo; Hashmi, Sara M; Nghiem, Long D; Elimelech, Menachem

    2015-11-17

    We investigated the role of reverse divalent cation diffusion in forward osmosis (FO) biofouling. FO biofouling by Pseudomonas aeruginosa was simulated using pristine and chlorine-treated thin-film composite polyamide membranes with either MgCl2 or CaCl2 draw solution. We related FO biofouling behavior-water flux decline, biofilm architecture, and biofilm composition-to reverse cation diffusion. Experimental results demonstrated that reverse calcium diffusion led to significantly more severe water flux decline in comparison with reverse magnesium permeation. Unlike magnesium, reverse calcium permeation dramatically altered the biofilm architecture and composition, where extracellular polymeric substances (EPS) formed a thicker, denser, and more stable biofilm. We propose that FO biofouling was enhanced by complexation of calcium ions to bacterial EPS. This hypothesis was confirmed by dynamic and static light scattering measurements using extracted bacterial EPS with the addition of either MgCl2 or CaCl2 solution. We observed a dramatic increase in the hydrodynamic radius of bacterial EPS with the addition of CaCl2, but no change was observed after addition of MgCl2. Static light scattering revealed that the radius of gyration of bacterial EPS with addition of CaCl2 was 20 times larger than that with the addition of MgCl2. These observations were further confirmed by transmission electron microscopy imaging, where bacterial EPS in the presence of calcium ions was globular, while that with magnesium ions was rod-shaped.

  6. Cationic gadolinium chelate for magnetic resonance imaging of cartilaginous defects.

    Science.gov (United States)

    Nwe, Kido; Huang, Ching-Hui; Qu, Feini; Warden-Rothman, Robert; Zhang, Clare Y; Mauck, Robert L; Tsourkas, Andrew

    2016-05-01

    The ability to detect meniscus defects by magnetic resonance arthrography (MRA) can be highly variable. To improve the delineation of fine tears, we synthesized a cationic gadolinium complex, (Gd-DOTA-AM4 )(2+) , that can electrostatically interact with Glycosaminoglycans (GAGs). The complex has a longitudinal relaxivity (r1) of 4.2 mM(-1) s(-1) and is highly stable in serum. Its efficacy in highlighting soft tissue tears was evaluated in comparison to a clinically employed contrast agent (Magnevist) using explants obtained from adult bovine menisci. In all cases, Gd-DOTA-AM4 appeared to improve the ability to detect the soft tissue defect by providing increased signal intensity along the length of the tear. Magnevist shows a strong signal near the liquid-meniscus interface, but much less contrast is observed within the defect at greater depths. This provides initial evidence that cationic contrast agents can be used to improve the diagnostic accuracy of MRA. Copyright © 2016 John Wiley & Sons, Ltd. PMID:26853708

  7. Structural Insights into Mitochondrial Calcium Uniporter Regulation by Divalent Cations.

    Science.gov (United States)

    Lee, Samuel K; Shanmughapriya, Santhanam; Mok, Mac C Y; Dong, Zhiwei; Tomar, Dhanendra; Carvalho, Edmund; Rajan, Sudarsan; Junop, Murray S; Madesh, Muniswamy; Stathopulos, Peter B

    2016-09-22

    Calcium (Ca(2+)) flux into the matrix is tightly controlled by the mitochondrial Ca(2+) uniporter (MCU) due to vital roles in cell death and bioenergetics. However, the precise atomic mechanisms of MCU regulation remain unclear. Here, we solved the crystal structure of the N-terminal matrix domain of human MCU, revealing a β-grasp-like fold with a cluster of negatively charged residues that interacts with divalent cations. Binding of Ca(2+) or Mg(2+) destabilizes and shifts the self-association equilibrium of the domain toward monomer. Mutational disruption of the acidic face weakens oligomerization of the isolated matrix domain and full-length human protein similar to cation binding and markedly decreases MCU activity. Moreover, mitochondrial Mg(2+) loading or blockade of mitochondrial Ca(2+) extrusion suppresses MCU Ca(2+)-uptake rates. Collectively, our data reveal that the β-grasp-like matrix region harbors an MCU-regulating acidic patch that inhibits human MCU activity in response to Mg(2+) and Ca(2+) binding.

  8. Effect of cationic monomer on properties of fluorinated acrylate latex

    Institute of Scientific and Technical Information of China (English)

    Li Jun Chen

    2012-01-01

    Cationic fluorinated acrylate latex was prepared via semi-continuous emulsion copolymerization of cationic monomer and other monomers.The resultant latex and its film were characterized with dynamic light scattering detector and contact angle meter.Influences of amount of DMDAAC on the properties of resultant latex and its film were investigated in detail.Results show that the particle size of the latex has the minimum value and the zeta potential of the latex is increased when the amount of DMDAAC is increased.In addition,the particle size of the latex is unimodal distribution when the amount of DMDAAC is not more than 2.5%.However,the particle size of the latex is bimodal distribution when the amount of DMDAAC is more than 2.5%.The contact angle is varied slightly with the increase of amount of DMDAAC when it is not more than 2.5%.Nevertheless,the contact angle is decreased with the increase of the amount of DMDAAC when it is more than 25%.

  9. Role of Reverse Divalent Cation Diffusion in Forward Osmosis Biofouling.

    Science.gov (United States)

    Xie, Ming; Bar-Zeev, Edo; Hashmi, Sara M; Nghiem, Long D; Elimelech, Menachem

    2015-11-17

    We investigated the role of reverse divalent cation diffusion in forward osmosis (FO) biofouling. FO biofouling by Pseudomonas aeruginosa was simulated using pristine and chlorine-treated thin-film composite polyamide membranes with either MgCl2 or CaCl2 draw solution. We related FO biofouling behavior-water flux decline, biofilm architecture, and biofilm composition-to reverse cation diffusion. Experimental results demonstrated that reverse calcium diffusion led to significantly more severe water flux decline in comparison with reverse magnesium permeation. Unlike magnesium, reverse calcium permeation dramatically altered the biofilm architecture and composition, where extracellular polymeric substances (EPS) formed a thicker, denser, and more stable biofilm. We propose that FO biofouling was enhanced by complexation of calcium ions to bacterial EPS. This hypothesis was confirmed by dynamic and static light scattering measurements using extracted bacterial EPS with the addition of either MgCl2 or CaCl2 solution. We observed a dramatic increase in the hydrodynamic radius of bacterial EPS with the addition of CaCl2, but no change was observed after addition of MgCl2. Static light scattering revealed that the radius of gyration of bacterial EPS with addition of CaCl2 was 20 times larger than that with the addition of MgCl2. These observations were further confirmed by transmission electron microscopy imaging, where bacterial EPS in the presence of calcium ions was globular, while that with magnesium ions was rod-shaped. PMID:26503882

  10. Enhanced apoptosis of ovarian cancer cells via nanocarrier-mediated codelivery of siRNA and doxorubicin

    Directory of Open Access Journals (Sweden)

    Zou S

    2012-07-01

    Full Text Available Seyin Zou,1,3,† Nuo Cao,1,† Du Cheng,2 Rongqin Zheng,4 Jin Wang,4 Kangshun Zhu,4 Xintao Shuai1,2 1Center of Biomedical Engineering, Zhongshan School of Medicine, 2PCFM Lab of Ministry of Education, School of Chemistry and Chemical Engineering, 3Department of Laboratory Medicine,The Third Affiliated Hospital, Guangzhou Medical University, 4The Third Affiliated Hospital, Sun Yat-Sen University, Guangzhou, China †These authors contributed equally to this workAbstract: A folate conjugated ternary copolymer, FA–PEG–PEI–PCL, of poly(ethylene glycol (PEG, poly(ethylene imine (PEI, and poly(ε-caprolactone (PCL was synthesized. The copolymer self-assembled into cationic micelles capable of co-delivering siRNA and the anticancer drug doxorubicin (DOX. This dual functional nanocarrier demonstrated low cytotoxicity and high performance in drug/siRNA delivery. Upon the codelivery of siRNA, targeting the Bcl-2 gene, and DOX, using the folate-targeted nanocarrier, DOX-induced apoptosis in the skov-3 cells overexpressing folate receptor was significantly enhanced through a mechanism of downregulating the antiapoptotic protein Bcl-2, while simultaneously upregulating the proapoptotic protein Bax. This work suggested that the combination of Bcl-2 siRNA and DOX therapies is feasible, based on our dual functional nanocarrier, which set up a good basis for a future in vivo test.Keywords: codelivery, gene silencing, chemotherapy, apoptosis, tumor targeting

  11. A Novel Method for the Determination of Membrane Hydration Numbers of Cations in Conducting Polymers

    DEFF Research Database (Denmark)

    Jafeen, M.J.M.; Careem, M.A.; Skaarup, Steen

    2012-01-01

    Polypyrrole polymer films doped with the large, immobile dodecy lbenzene sulfonate anions operating in alkali halide aqueous electroly tes has beenused as a novel physico-chemical environment to develop a more direct way of obtaining reliable values for the hydration numbers of cations. Simultane......Polypyrrole polymer films doped with the large, immobile dodecy lbenzene sulfonate anions operating in alkali halide aqueous electroly tes has beenused as a novel physico-chemical environment to develop a more direct way of obtaining reliable values for the hydration numbers of cations...... reduction process. The goal was to investigate both the effects of cation size and of cation charge. The membrane hydration number values obtained by this simple and direct method for a number of cations are: The hydration number for all of these cations seems to follow the same simple relation....

  12. Flexible polyelectrolyte conformation in the presence of cationic and anionic surfactants

    Science.gov (United States)

    Passos, C. B.; Kuhn, P. S.; Diehl, A.

    2015-11-01

    In this work we have studied the conformation of flexible polyelectrolyte chains in the presence of cationic and anionic surfactant molecules. We developed a simple theoretical model for the formation of the polyelectrolyte-cationic surfactant complexes and mixed micelles formed by cationic and anionic surfactant molecules, in the framework of the Debye-Hückel-Bjerrum-Manning and Flory theories, with the hydrophobic interaction included explicitly as an effective short-ranged attraction between the surfactant hydrocarbon tails. This simple model allows us to calculate the extension of the polyelectrolyte-cationic surfactant complexes as a function of the anionic surfactant concentration, for different types of cationic and anionic surfactant molecules. A discrete conformational transition from a collapsed state to an elongated coil was found, for all surfactant chain lengths we have considered, in agreement with the experimental observations for the unfolding of ​DNA-cationic surfactant complexes.

  13. Atomistic understanding of cation exchange in PbS nanocrystals using simulations with pseudoligands

    Science.gov (United States)

    Fan, Zhaochuan; Lin, Li-Chiang; Buijs, Wim; Vlugt, Thijs J. H.; van Huis, Marijn A.

    2016-05-01

    Cation exchange is a powerful tool for the synthesis of nanostructures such as core-shell nanocrystals, however, the underlying mechanism is poorly understood. Interactions of cations with ligands and solvent molecules are systematically ignored in simulations. Here, we introduce the concept of pseudoligands to incorporate cation-ligand-solvent interactions in molecular dynamics. This leads to excellent agreement with experimental data on cation exchange of PbS nanocrystals, whereby Pb ions are partially replaced by Cd ions from solution. The temperature and the ligand-type control the exchange rate and equilibrium composition of cations in the nanocrystal. Our simulations reveal that Pb ions are kicked out by exchanged Cd interstitials and migrate through interstitial sites, aided by local relaxations at core-shell interfaces and point defects. We also predict that high-pressure conditions facilitate strongly enhanced cation exchange reactions at elevated temperatures. Our approach is easily extendable to other semiconductor compounds and to other families of nanocrystals.

  14. Retinoids induce Nur77-dependent apoptosis in mouse thymocytes.

    Science.gov (United States)

    Kiss, Beáta; Tóth, Katalin; Sarang, Zsolt; Garabuczi, Éva; Szondy, Zsuzsa

    2015-03-01

    Nur77 is a transcription factor, which plays a determinant role in mediating T cell receptor-induced cell death of thymocytes. In addition to regulation of transcription, Nur77 contributes to apoptosis induction by targeting mitochondria, where it can convert Bcl-2, an anti-apoptotic protein into a proapoptotic molecule. Previous studies have demonstrated that retinoids are actively produced in the mouse thymus and can induce a transcription-dependent apoptosis in mouse thymocytes. Here we show that retinoic acids induce the expression of Nur77, and retinoid-induced apoptosis is completely dependent on Nur77, as retinoids were unable to induce apoptosis in Nur77 null thymocytes. In wild-type thymocytes retinoids induced enhanced expression of the apoptosis-related genes FasL, TRAIL, NDG-1, Gpr65 and Bid, all of them in a Nur77-dependent manner. The combined action of these proteins led to Caspase 8-dependent Bid cleavage in the mitochondria. In addition, we could demonstrate the Nur77-dependent induction of STAT1 leading to enhanced Bim expression, and the mitochondrial translocation of Nur77 leading to the exposure of the Bcl-2/BH3 domain. The retinoid-induced apoptosis was dependent on both Caspase 8 and STAT1. Our data together indicate that retinoids induce a Nur77-dependent cell death program in thymocytes activating the mitochondrial pathway of apoptosis. PMID:25576519

  15. Apoptosis of human pancreatic cancer cells induced by Triptolide

    Institute of Scientific and Technical Information of China (English)

    Guo-Xiong Zhou; Xiao-Ling Ding; Jie-Fei Huang; Hong Zhang; Sheng-Bao Wu; Jian-Ping Cheng; Qun Wei

    2008-01-01

    AIM:To investigate apoptosis in human pancreatic cancer ceils induced by Triptolide (TL),and the relationship between this apoptosis and expression of caspase-3' bcl-2 and bax.METHODS:Human pancreatic cancer cell line SW1990 was cultured in DIEM media for this study.MTT assay was used to determine the cell growth inhibitory rate in vitro.Flow cytometry and TUNEL assay were used to detect the apoptosis of human pancreatic cancer cells before and after TL treatment.RT-PCR was used to detect the expression of apoptosis-associated gene caspase-3' bcl-2 and bax.RESULTS:TL inhibited the growth of human pancreatic cancer cells in a dose-and time-dependent manner.TL induced human pancreatic cancer cells to undergo apoptosis with typically apoptotic characteristics.TUNEL assay showed that after the treatment of human pancreatic cancer cells with 40 ng/mL TL for 12 h and 24 h,the apoptotic rates of human pancreatic cancer cells increased significantly.RT-PCR demonstrated that caspase-3 and bax were significantly up-regulated in SW1990 cells treated with TL while bcl-2 mRNA was not.CONCLUSION:TL is able to induce the apoptosis in human pancreatic cancer cells.This apoptosis may be mediated by up-regulating the expression of apoptosisassociated caspase-3 and bax gene.

  16. APOPTOSIS OF HYPERPLASIA AND CANCER OF THE GALLBLADDER WITH CALCULAS

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Objective:To investigate the relation between different extent of proliferation caused by gallstone and gallbladder cancer by counting the proliferation and the apoptosis of the gallbladder cancer for the clinically prevention of the gallbladder carcinoma.Methods:The TUNEL method was used to detect the apoptosis of the specimens and the mean apoptosis indices obtained by quantification of apoptosis cells flurescence by laser scanning confocal microscope were compared among the varible pathological paterns,Results:The mean apoptosis indexed in the mormal and abnormal specimens with cholecystits,simple hyperplasia,low-grade dysplasia,mid-grade dysplasia,high-grade dysplasia and carcinoma were 5.11,5.49,6.32,8.65,12.27,25.24,39.62,119.8,respectively.There was significant difference among the variable pathological patterns and as the lesion progressing,the index went up gradually with the carcinoma had the highest index.Conclusion:the apoptosis indexes increase with the pathological progress during the carcinogenesis of gallbladder cancer caused by lithiasis,which stimulate the epithelium for long time and result in an increasing of the apoptosis;and it may play an important role in the carcinogenesis of gallbladder cancer.

  17. APOPTOSIS OF HYPERPLASIA AND CANCER OF THE GALLBLADDER WITH CALCULAS

    Institute of Scientific and Technical Information of China (English)

    赵凤林; 石景森; 朱爱军; 王健生; 韩月

    2002-01-01

    Objective To investigate the relation between dif ferent extent of proliferation caused by gallstone and gallbladder cancer by cou nting the proliferation and the apoptosis of the gallbladder cancer for the clin ically prevention of the gallbladder carcinoma.Methods The TUNE L method was used to detect the apoptosis of the specimens and the mean apoptosi s indices obtained by quantification of apoptosis cells fluorescence by laser sc anning confocal microscope were compared among the variable pathological pattern s.Results The mean apoptosis indexes in the mormal and abnormal specimens with cholecystitis,simple hyperplasia, low-grade dysplasia, mid-gra de dysplasia, high-grade dysplasia and carcinoma were 5.11, 5.49, 6.32, 8.65, 1 2.27, 25.24, 39.62, 119.8, respectively. There was significant difference among the variable pathological patterns and as the lesion progressing, the index went up gradually with the carcinoma had the highest index. Conclusion The apoptosis indexes increase with the pathological progress during the car cinogenesis of gallbladder cancer caused by lithiasis, which stimulate the epith elium for long time and result in an increasing of the apoptosis; and it may pla y an important role in the carcinogenesis of gallbladder cancer.

  18. Recovering drug-induced apoptosis subnetwork from Connectivity Map data.

    Science.gov (United States)

    Yu, Jiyang; Putcha, Preeti; Silva, Jose M

    2015-01-01

    The Connectivity Map (CMAP) project profiled human cancer cell lines exposed to a library of anticancer compounds with the goal of connecting cancer with underlying genes and potential treatments. Since the therapeutic goal of most anticancer drugs is to induce tumor-selective apoptosis, it is critical to understand the specific cell death pathways triggered by drugs. This can help to better understand the mechanism of how cancer cells respond to chemical stimulations and improve the treatment of human tumors. In this study, using CMAP microarray data from breast cancer cell line MCF7, we applied a Gaussian Bayesian network modeling approach and identified apoptosis as a major drug-induced cellular-pathway. We then focused on 13 apoptotic genes that showed significant differential expression across all drug-perturbed samples to reconstruct the apoptosis network. In our predicted subnetwork, 9 out of 15 high-confidence interactions were validated in the literature, and our inferred network captured two major cell death pathways by identifying BCL2L11 and PMAIP1 as key interacting players for the intrinsic apoptosis pathway and TAXBP1 and TNFAIP3 for the extrinsic apoptosis pathway. Our inferred apoptosis network also suggested the role of BCL2L11 and TNFAIP3 as "gateway" genes in the drug-induced intrinsic and extrinsic apoptosis pathways. PMID:25883971

  19. The interplays between autophagy and apoptosis induced by enterovirus 71.

    Directory of Open Access Journals (Sweden)

    Xueyan Xi

    Full Text Available BACKGROUND: Enterovirus 71 (EV71 is the causative agent of human diseases with distinct severity, from mild hand, foot and mouth disease to severe neurological syndromes, such as encephalitis and meningitis. The lack of understanding of viral pathogenesis as well as lack of efficient vaccine and drugs against this virus impedes the control of EV71 infection. EV71 virus induces autophagy and apoptosis; however, the relationship between EV71-induced autophagy and apoptosis as well as the influence of autophagy and apoptosis on virus virulence remains unclear. METHODOLOGY/PRINCIPAL FINDINGS: In this study, it was observed that the Anhui strain of EV71 induced autophagy and apoptosis in human rhabdomyosarcoma (RD-A cells. Additionally, by either applying chemical inhibitors or knocking down single essential autophagic or apoptotic genes, inhibition of EV71 induced autophagy inhibited the apoptosis both at the autophagosome formation stage and autophagy execution stage. However, inhibition of autophagy at the stage of autophagosome and lysosome fusion promoted apoptosis. In reverse, the inhibition of EV71-induced apoptosis contributed to the conversion of microtubule-associated protein 1 light chain 3-I (LC3-I to LC3-II and degradation of sequestosome 1 (SQSTM1/P62. Furthermore, the inhibition of autophagy in the autophagsome formation stage or apoptosis decreased the release of EV71 viral particles. CONCLUSIONS/SIGNIFICANCE: In conclusion, the results of this study not only revealed novel aspect of the interplay between autophagy and apoptosis in EV71 infection, but also provided a new insight to control EV71 infection.

  20. Apoptosis of circulating lymphocytes during pediatric cardiac surgery

    Science.gov (United States)

    Bocsi, J.; Pipek, M.; Hambsch, J.; Schneider, P.; Tárnok, A.

    2006-02-01

    There is a constant need for clinical diagnostic systems that enable to predict disease course for preventative medicine. Apoptosis, programmed cell death, is the end point of the cell's response to different induction and leads to changes in the cell morphology that can be rapidly detected by optical systems. We tested whether apoptosis of T-cells in the peripheral blood is useful as predictor and compared different preparation and analytical techniques. Surgical trauma is associated with elevated apoptosis of circulating leukocytes. Increased apoptosis leads to partial removal of immune competent cells and could therefore in part be responsible for reduced immune defence. Cardiovascular surgery with but not without cardiopulmonary bypass (CPB) induces transient immunosuppression. Its effect on T-cell apoptosis has not been shown yet. Flow-cytometric data of blood samples from 107 children (age 3-16 yr.) who underwent cardiac surgery with (78) or without (29) CPB were analysed. Apoptotic T-lymphocytes were detected based on light scatter and surface antigen (CD45/CD3) expression (ClinExpImmunol2000;120:454). Results were compared to staining with CD3 antibodies alone and in the absence of antibodies. T-cell apoptosis rate was comparable when detected with CD45/CD3 or CD3 alone, however not in the absence of CD3. Patients with but not without CPB surgery had elevated lymphocyte apoptosis. T-cell apoptosis increased from 0.47% (baseline) to 0.97% (1 day postoperatively). In CPB patients with complication 1.10% significantly higher (ANOVA p=0.01) comparing to CPB patients without complications. Quantitation of circulating apoptotic cells based on light scatter seems an interesting new parameter for diagnosis. Increased apoptosis of circulating lymphocytes and neutrophils further contributes to the immune suppressive response to surgery with CPB. (Support: MP, Deutsche Herzstiftung, Frankfurt, Germany)

  1. Tryptophan fluorescence quenching by alkaline earth metal cations in deionized bacteriorhodopsin.

    Science.gov (United States)

    Wang, G; Wang, A J; Hu, K S

    2000-12-01

    Tryptophan quenching by the addition of alkaline earth metal cations to deionized bacteriorhodopsin suspensions was determined. The results show that the addition of cation primarily quenches fluorescence from surface tryptophan residues. The quenched intensity exhibits a 1/R dependence, where R is the ionic radius of the corresponding metal ion. This observation results from a stronger energy transfer coupling between the tryptophan and the retinal. The membrane curvature may be involved as a result of cations motion and correlated conformational changes. PMID:11332888

  2. Removal of metal cations from wastewater using recycled wool-based non-woven material

    OpenAIRE

    MAJA RADETIC; DARINKA RADOJEVIC; VESNA ILIC; DRAGAN JOCIC; DRAGAN POVRENOVIC; BRANISLAV POTKONJAK; NEVENA PUAC; PETAR JOVANCIC

    2007-01-01

    In this study, the effect of low-temperature air plasma, biopolymer chitosan and hydrogen peroxide treatment of recycled wool-based non-woven material on metal cation uptake was investigated. Recycled wool-based material either as an untreated or modified material showed ability to bind all investigated metal cations in the following order: Pb2+>Cu2+>Zn2+>Co2+. Material performed good selectivity due to distinct sorption rates of studied metal cations.

  3. The interaction of gold and silver nanoparticles with a range of anionic and cationic dyes

    OpenAIRE

    Kitching, H; Kenyon, A. J.; Parkin, I. P.

    2014-01-01

    We describe the synthesis of charge-stabilised gold and silver nanoparticles by a modified Turkevich method and their interaction with a selection of cationic and anionic dyes. It was found that gold nanoparticles interact strongly with cationic dyes and in some cases enhanced absorption was observed by UV-visible spectroscopy. It is also shown that addition of cationic dyes to gold nanoparticles triggers aggregation of the nanoparticles into large, micrometre-scale clusters. Simultaneous fra...

  4. Calcium-sensing receptor activation contributed to apoptosis stimulates TRPC6 channel in rat neonatal ventricular myocytes

    International Nuclear Information System (INIS)

    Capacitative calcium entry (CCE) refers to the influx of calcium through plasma membrane channels activated on depletion of endoplasmic sarcoplasmic/reticulum (ER/SR) Ca2+ stores, which is performed mainly by the transient receptor potential (TRP) channels. TRP channels are expressed in cardiomyocytes. Calcium-sensing receptor (CaR) is also expressed in rat cardiac tissue and plays an important role in mediating cardiomyocyte apoptosis. However, there are no data regarding the link between CaR and TRP channels in rat heart. In this study, in rat neonatal myocytes, by Ca2+ imaging, we found that the depletion of ER/SR Ca2+ stores by thapsigargin (TG) elicited a transient rise in cytoplasmic Ca2+ ([Ca2+]i), followed by sustained increase depending on extracellular Ca2+. But, TRP channels inhibitor (SKF96365), not L-type channels or the Na+/Ca2+ exchanger inhibitors, inhibited [Ca2+]i relatively high. Then, we found that the stimulation of CaR with its activator gadolinium chloride (GdCl3) or by an increased extracellular Ca2+([Ca2+]o) increased the concentration of intracelluar Ca2+, whereas, the sustained elevation of [Ca2+]i was reduced in the presence of SKF96365. Similarly, the duration of [Ca2+]i increase was also shortened in the absence of extracellular Ca2+. Western blot analysis showed that GdCl3 increased the expression of TRPC6, which was reversed by SKF96365. Additionally, SKF96365 reduced cardiomyocyte apoptosis induced by GdCl3. Our results suggested that CCE exhibited in rat neonatal myocytes and CaR activation induced Ca2+-permeable cationic channels TRPCs to gate the CCE, for which TRPC6 was one of the most likely candidates. TRPC6 channel was functionally coupled with CaR to enhance the cardiomyocyte apoptosis.

  5. Influence of competing inorganic cations on the ion exchange equilibrium of the monovalent organic cation metoprolol on natural sediment.

    Science.gov (United States)

    Niedbala, Anne; Schaffer, Mario; Licha, Tobias; Nödler, Karsten; Börnick, Hilmar; Ruppert, Hans; Worch, Eckhard

    2013-02-01

    The aim of this study was to systematically investigate the influence of the mono- and divalent inorganic ions Na(+) and Ca(2+) on the sorption behavior of the monovalent organic cation metoprolol on a natural sandy sediment at pH=7. Isotherms for the beta-blocker metoprolol were obtained by sediment-water batch tests over a wide concentration range (1-100000 μg L(-1)). Concentrations of the competing inorganic ions were varied within freshwater relevant ranges. Data fitted well with the Freundlich sorption model and resulted in very similar Freundlich exponents (n=0.9), indicating slightly non-linear behavior. Results show that the influence of Ca(2+) compared to Na(+) is more pronounced. A logarithmic correlation between the Freundlich coefficient K(Fr) and the concentration or activity of the competing inorganic ions was found allowing the prediction of metoprolol sorption on the investigated sediment at different electrolyte concentrations. Additionally, the organic carbon of the sediment was completely removed for investigating the influence of organic matter on the sorption of metoprolol. The comparison between the experiments with and without organic carbon removal revealed no significant contribution of the organic carbon fraction (0.1%) to the sorption of metoprolol on the in this study investigated sediment. Results of this study will contribute to the development of predictive models for the transport of organic cations in the subsurface.

  6. Executionary pathway for apoptosis: lessons from mutant mice

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Apoptosis or programmed cell death (PCD) is an evolutionarily conserved cellular process that is essential for normal development and homeostasis of multicellular organisms. Defects in the apoptosis signaling result in many diseases including autoimmune diseases and cancer. The apoptosis signaling pathway was first described genetically in the nematode Caenorhabditis elegans which serves as a framework for the more complex apop totic pathways that exist in mammals. In this review, we will discuss the apoptotic pathways that are emerging in mammals as elucidated by studies of gene-targeted mutant mice.

  7. INHIBITION OF SPONTANEOUS APOPTOSIS IN HUMAN BREAST CANCER

    Institute of Scientific and Technical Information of China (English)

    邵志敏; 江明; 吴炅; 余黎民; 韩企夏; 张延璆; 沈镇宙

    1996-01-01

    Breast tumorigenesis proceeds through an accumulation of specific genetic alteration. Breast malignant transformation is dependent on not only the rate of cell production but also on apoptcsis,a genetically prograined process of autonomous ceil death. We investigated whether breast tumorigenesis involved an altered susceptibility to apoptosis and proliferation by examining normal breast epithelium and breast cancer sampies. We found there is a great inhibition of spontaneous apoptosis in breast cancer ceils compared with normal breast epithelium. The inhibition of apoptosis in breast cancer may contribute to neoplastic transformation.

  8. Stochastic modeling of p53-regulated apoptosis upon radiation damage

    CERN Document Server

    Bhatt, Divesh; Bahar, Ivet

    2011-01-01

    We develop and study the evolution of a model of radiation induced apoptosis in cells using stochastic simulations, and identified key protein targets for effective mitigation of radiation damage. We identified several key proteins associated with cellular apoptosis using an extensive literature survey. In particular, we focus on the p53 transcription dependent and p53 transcription independent pathways for mitochondrial apoptosis. Our model reproduces known p53 oscillations following radiation damage. The key, experimentally testable hypotheses that we generate are - inhibition of PUMA is an effective strategy for mitigation of radiation damage if the treatment is administered immediately, at later stages following radiation damage, inhibition of tBid is more effective.

  9. Photoinduced apoptosis using a peptide carrying a photosensitizer.

    Science.gov (United States)

    Watanabe, Kazunori; Fujiwara, Hayato; Kitamatsu, Mizuki; Ohtsuki, Takashi

    2016-07-01

    A novel molecule, TatBim-Alexa, consisting of the HIV1 Tat cell-penetrating peptide, the Bim apoptosis-inducing peptide, and Alexa Fluor 546 was synthesized for photoinducion of apoptosis. The Alexa Fluor 546 was used as a photosensitizer and covalently attached at the C-terminus of TatBim peptide by the thiol-maleimide reaction. Photo-dependent cytosolic internalization of TatBim-Alexa and photo-dependent apoptosis using TatBim-Alexa were demonstrated in several kinds of mammalian cells including human cancer cell lines. PMID:27165853

  10. Effect of heavy metal cations on the activity of cathepsin D (in vitro study).

    Science.gov (United States)

    Karwowska, Alicja; Łapiński, Radosław; Gacko, Marek; Grzegorczyk, Ewa; Żurawska, Joanna; Karczewski, Jan K

    2012-01-01

    We studied the effect of heavy metal cations: Fe²⁺, Cu²⁺, Zn²⁺, Cd²⁺, Hg²⁺, Pb²⁺ on the activity of cathepsin D in human aorta homogenate and blood serum. The concentration of cations was 1 mmol/l. Hemoglobin was the cathepsin D substrate. The activity of cathepsin D was determined at pH 3.5. Only Hg²⁺ cations inhibit the activity of cathepsin D. Cations Hg²⁺ damage lysosomes and release cathepsin D from these organelles. PMID:23042275

  11. Effects of aluminum and other cations on the structure of brain and liver chromatin.

    Science.gov (United States)

    Walker, P R; LeBlanc, J; Sikorska, M

    1989-05-01

    The reactivity of aluminum and several other divalent and trivalent metallic cations toward chromatin from rat brain and liver has been investigated. Two criteria are used to determine the relative reactivity of these cations toward chromatin. The first involves the ability of the ions to compact the chromatin fibers to the point where chromatin precipitates. The second criterion measures the ability of cations to interfere with the accessibility of exogenous structural probes (nucleases) to chromatin. Of the divalent cations tested, nickel, cobalt, zinc, cadmium, and mercury were the most reactive toward chromatin, on the basis of their ability to induce precipitation of chromatin in the micromolar concentration range. The divalent cations magnesium, calcium, copper, strontium, and barium were much less effective, although all cations precipitate chromatin if their concentration is increased. Of the trivalent cations tested, aluminum, indium, and gallium were very effective precipitants, whereas iron and scandium were without effect at the concentrations tested. Of all the cations tested, aluminum was the most reactive. Aluminum's ability to alter the structure of chromatin was investigated further by testing its ability to interfere with nuclease accessibility. This test confirmed that aluminum does induce considerable changes in chromatin structure at micromolar concentrations. Furthermore, chromatin from cortical areas of the brain was much more sensitive to aluminum than chromatin from liver. These results are discussed in light of the known toxicity of these cations, with particular emphasis on the possible role of aluminum in Alzheimer's disease. PMID:2752000

  12. SANS study on the complex of cationic micelles and anionic polyelectrolytes

    International Nuclear Information System (INIS)

    We investigated the complex of cationic micelles and anionic polyelectrolytes. The cationic micelles have the composition of nonionic surfactant, Octa-ethyleneglycol mono n-tetradecyl ether (C14E8) and cationic surfactant, Tetradecyltrimethylammonium Bromide (TTAB), and the polyelectrolyte is Poly Styrene Sulfonic Acid, Sodium Salt (Mw.= 73900, PSS80k). By the charge interaction, they formed the complexes in the aqueous solution. This complex was studied by Small Angle Neutron Scattering (SANS). SANS study showed that the size distribution changed by the cationic surfactant-to-polyelectrolyte charge ratio. The structure of this complex was also studied

  13. Induction of Apoptosis and expression of Apoptosis-related gene products in response to radiation in murine tumors

    International Nuclear Information System (INIS)

    To analyze the involvement of apoptosis regulatory genes p53, p21waf1/cip1, bax and bcl-2 in induction of apoptosis by radiation in murine tumors. The radiation-sensitive ovarian carcinoma OCa-I and the radiation-resistant hepatocarcinoma HCa-I were used. Tumors, 8mm in diameter, were irradiated with 25Gy and at various times after irradiation, ranging from 1 to 48 h, were analyzed histologically for apoptosis and by western blot for alterations in the expression of these genes. The p53 status of the tumors were determined by the polymerase chain reaction-single strand conformation polymorphism assay. Both tumors were positive for wild-type p53. Radiation induced apoptosis in OCa-I but not in HCa-I. Apoptosis developed rapidly, peaked at 2 h after irradiation and returned to almost the background level at 48 h. In OCa-I radiation upregulated the expression of p53, p21waf1/cip1, and the bcl-2/bax ratio was decreased. In HCa-I radiation increased the expression of both p53 and p21waf1/cip1, although the increase of the latter was small. The bcl-2/bax ratio was greatly increased. In general the observed changes occurred within a few hours after irradiation, and either preceded or coincided with development of apoptosis. The development of apoptosis required upregulation of both p53 and p21waf1/cip1 as well as a decrease in bcl-2/bax ratio. In contrast, an increase in bcl-2/bax ratio prevented apoptosis in the presence of upregulated p53 and p21waf1/cip1. These findings identified the involvement of multiple oncogenes in apoptosis regulation in vivo and demonstrate the complexity that may be associated with the use of a single oncogene assessment for predicting the outcome of cancer therapy with cytotoxic agents. (author)

  14. Overexpressed TP73 induces apoptosis in medulloblastoma

    Directory of Open Access Journals (Sweden)

    Perlaky Laszlo

    2007-07-01

    Full Text Available Abstract Background Medulloblastoma is the most common malignant brain tumor of childhood. Children who relapse usually die of their disease, which reflects resistance to radiation and/or chemotherapy. Improvements in outcome require a better understanding of the molecular basis of medulloblastoma growth and treatment response. TP73 is a member of the TP53 tumor suppressor gene family that has been found to be overexpressed in a variety of tumors and mediates apoptotic responses to genotoxic stress. In this study, we assessed expression of TP73 RNA species in patient tumor specimens and in medulloblastoma cell lines, and manipulated expression of full-length TAp73 and amino-terminal truncated ΔNp73 to assess their effects on growth. Methods We analyzed medulloblastoma samples from thirty-four pediatric patients and the established medulloblastoma cell lines, Daoy and D283MED, for expression of TP73 RNA including the full-length transcript and the 5'-terminal variants that encode the ΔNp73 isoform, as well as TP53 RNA using quantitative real time-RTPCR. Protein expression of TAp73 and ΔNp73 was quantitated with immunoblotting methods. Clinical outcome was analyzed based on TP73 RNA and p53 protein expression. To determine effects of overexpression or knock-down of TAp73 and ΔNp73 on cell cycle and apoptosis, we analyzed transiently transfected medulloblastoma cell lines with flow cytometric and TUNEL methods. Results Patient medulloblastoma samples and cell lines expressed full-length and 5'-terminal variant TP73 RNA species in 100-fold excess compared to non-neoplastic brain controls. Western immunoblot analysis confirmed their elevated levels of TAp73 and amino-terminal truncated ΔNp73 proteins. Kaplan-Meier analysis revealed trends toward favorable overall and progression-free survival of patients whose tumors display TAp73 RNA overexpression. Overexpression of TAp73 or ΔNp73 induced apoptosis under basal growth conditions in vitro and

  15. Cation-Induced Coiling of Vanadium Pentoxide Nanobelts

    Directory of Open Access Journals (Sweden)

    Liu Jun

    2010-01-01

    Full Text Available Abstract Single-crystalline V2O5·xH2O nanorings and microloops were chemically assembled via an ion-induced chemical spinning route in the designed hydrothermal system. The morphology and structure of products were investigated by means of scanning electron microscopy (SEM and transmission electron microscopy (TEM. X-ray powder diffraction (XRD measurement, energy-dispersive X-ray spectroscopy (EDS microanalysis and thermal gravimetric analysis (TGA revealed that the composition of nanorings and microloops is V2O5·1·1H2O. For these oxide nanorings and microloops, the cation-induced coiling growth mechanism of vanadium pentoxide nanobelts has been proposed on the basis of crystallographic structure of vanadium pentoxide. Our proposed chemical spinning process and the rational solution-phase synthesis route can also be extended to prepare novel 1D materials with layered or more complex structures.

  16. A spectroscopic study of interaction of cationic dyes with heparin

    Directory of Open Access Journals (Sweden)

    R. Nandini

    2010-01-01

    Full Text Available The interaction of two cationic dyes namely, acridine orange and pinacyanol chloride with an anionic polyelectrolyte, heparin, has been investigated by spectrophotometric method.The polymer induced metachromasy in the dyes resulting in the shift of the absorption maxima of the dyes towards shorter wavelengths. The stability of the complexes formed between acridine orange and heparin was found to be lesser than that formed between pinacyanol chloride and heparin. This fact was further confirmed by reversal studies using alcohols, urea and surfactants. The interaction of acridine orange with heparin has also been investigated fluorimetrically.The interaction parameters revealed that binding between acridine orange and heparin arises due to electrostatic interaction while that between pinacyanol chloride and heparin is found to involve both electrostatic and hydrophobic forces. The effect of the structure of the dye in inducing metachromasy has also been discussed.

  17. Ion dynamics in cationic lipid bilayer systems in saline solutions

    DEFF Research Database (Denmark)

    Miettinen, Markus S; Gurtovenko, Andrey A; Vattulainen, Ilpo;

    2009-01-01

    concentration on the dynamical properties of these cationic lipid bilayer systems. We find that, despite the fact that DMPCs form complexes via Na(+) ions that bind to the lipid carbonyl oxygens, NaCl concentration has a rather minute effect on lipid diffusion. We also find the dynamics of Cl(-) and Na(+) ions...... at the water-membrane interface to differ qualitatively. Cl(-) ions have well-defined characteristic residence times of nanosecond scale. In contrast, the binding of Na(+) ions to the carbonyl region appears to lack a characteristic time scale, as the residence time distributions displayed power-law features....... As to lateral dynamics, the diffusion of Na(+) ions within the water-membrane interface consists of two qualitatively different modes of motion: very slow diffusion when ions are bound to DMPC, punctuated by fast rapid jumps when detached from the lipids. Overall, the prolonged dynamics of the Na(+) ions...

  18. Investigation on the aggregation properties of cationic [60]fullerene derivative

    Institute of Scientific and Technical Information of China (English)

    WANG Guanwu; ZHAO Guoxia; YAN Lifeng

    2004-01-01

    The UV-Vis spectra, HRTEM and AFM images of cationic fullerene derivative 1 with ammonium head group directly connected to C60 skeleton in tetrahydrofuran (THF)-water (H2O) binary mixtures and in pure H2O were investigated. It was found that the UV-Vis spectra of ammonium 1 in the THF-H2O mixtures with THF% ≥ 20% were nearly overlapped, while those with THF% < 20% showed broadened and red-shifted peaks, indicating the formation of aggregates. Corresponding to the UV-Vis spectral changes,the solvatochromism of ammonium 1 in THF-H2O mixtures was observed. Ammonium 1 in binary THF-H2O mixtures existing as the monomer state could aggregate upon prolonged standing. Higher temperature and lower concentration speeded up the aggregation process.

  19. Ab initio study of the transition-metal carbene cations

    Institute of Scientific and Technical Information of China (English)

    李吉海; 冯大诚; 冯圣玉

    1999-01-01

    The geometries and bonding characteristics of the first-row transition-metal carbene cations MCH2+ were investigated by ab initio molecular orbital theory (HF/LANL2DZ). All of MCH2+ are coplanar. In the closed shell structures the C bonds to M with double bonds; while in the open shell structures the partial double bonds are formed, because one of the σ and π orbitals is singly occupied. It is mainly the π-type overlap between the 2px orbital of C and 4px, 3dxz, orbitals of M+ that forms the π orbitals. The dissociation energies of C—M bond appear in periodic trend from Sc to Cu. Most of the calculated bond dissociation energies are close to the experimental ones.

  20. Quantitative mapping of intracellular cations in the human amniotic membrane

    Science.gov (United States)

    Moretto, Ph.; Llabador, Y.; Simonoff, M.; Razafindrabe, L.; Bara, M.; Guiet-Bara, A.

    1993-05-01

    The effect of magnesium and taurine on the permeability of cell membranes to monovalent cations has been investigated using the Bordeaux nuclear microprobe. PIXE and RBS techniques have been used to provide quantitative measurements and ion distributions in the isolated amniotic membrane. This physiological model for cellular exchanges allowed us to reveal the distribution of most elements involved in cellular pathways and the modifications under different experimental conditions of incubation in physiological fluids. The PIXE microanalysis provided an original viewpoint on these mechanisms. Following this first study, the amnion compact lamina was found to play a role which was not, up to now, taken into account in the interpretation of electrophysiological experimentations. The release of some ionic species, such as K +, from the epithelial cells, during immersion in isotonic fluids, could have been hitherto underestimated.

  1. Modulation of mechanosensitive calcium-selective cation channels by temperature

    Science.gov (United States)

    Ding, J. P.; Pickard, B. G.

    1993-01-01

    Gating of associations of mechanosensitive Ca(2+)-selective cation co-channels in the plasmalemma of onion epidermis has a strong and unusual temperature dependence. Tension-dependent activity rises steeply as temperature is lowered from 25 degrees C to about 6 degrees C, but drops to a low level at about 5 degrees C. Under the conditions tested (with Mg2+ and K+ at the cytosolic face of outside-out membrane patches), promotion results both from more bursting at all observed linkage levels and from longer duration of bursts of co-channels linked as quadruplets and quintuplets. Co-channel conductance decreases linearly, but only modestly, with declining temperature. It is proposed that these and related mechanosensitive channels may participate in a variety of responses to temperature, including thermonasty, thermotropism, hydrotropism, and both cold damage and cold acclimation.

  2. Interpnictogen cations: exploring new vistas in coordination chemistry.

    Science.gov (United States)

    Robertson, Alasdair P M; Gray, Paul A; Burford, Neil

    2014-06-10

    Pnictine derivatives can behave as both 2e(-) donors (Lewis bases) and 2e(-) acceptors (Lewis acids). As prototypical ligands in the coordination chemistry of transition metals, amines and phosphines also form complexes with p-block Lewis acids, including a variety of pnictogen-centered acceptors. The inherent Lewis acidity of pnictogen centers can be enhanced by the introduction of a cationic charge, and this feature has been exploited in recent years in the development of compounds resulting from coordinate Pn-Pn and Pn-Pn' interactions. These compounds offer the unusual opportunity for homoatomic coordinate bonding and the development of complexes that possess a lone pair of electrons at the acceptor center. This Review presents new directions in the systematic extension of coordination chemistry from the transition series into the p-block.

  3. Reaction between sulfur dioxide and iron oxide cationic clusters

    Institute of Scientific and Technical Information of China (English)

    YIN Shi; HE ShengGui; HE ShengGui; GE MaoFa; GE MaoFa

    2009-01-01

    The reactivity of sulfur dioxide (SO_2) molecules toward iron oxide cationic clusters (Fe_mO_n~+) is studied by a homemade time-of-flight mass spectrometer coupled with a laser ablation/supersonic expansion cluster source and a fast flow reactor.The association products Fe_mO_nSO_2~+ can be observed for most of the clusters.The interesting result is that the cooperation effect of SO_2 and water is in favor of the adsorption of gas phase water on specific scale iron oxide clusters (Fe_2O_2~+ and Fe_3O_3~+).The reactivity information obtained may be useful to investigate atmospheric heterogeneous chemistry of related systems.

  4. Synthesis and Properties of Gemini Cationic Surfactants with Amide Spacers

    Institute of Scientific and Technical Information of China (English)

    DENG Qi-gang; YU Hong-wei; LIN Hong; JIA Li-hua; GUO Xiang-feng; ZHOU De-rui

    2005-01-01

    Four gemini cationic surfactants {N,N'-di[2-(lauryldimethylamino)acetyl]polymethylenediamine dichloride, LAA-s-LAA, s=2,3,4,6} were synthesized by using four bis(α-chloroacetamide)s and N,N-dimethyllaurylamine, respectively. The molecular structures were characterized by means of IR, 1H NMR, 13C NMR and MS, and the behavior of their aqueous solutions was studied. The critical micell concentrations(CMC) of LAA-s-LAA were one order of magnitude lower than that of dodecyltrimethyl ammonium chloride(DTAC). With the change of the length of spacer chain(s), their CMC values change, and CMC reaches the top value at s=4.

  5. EXCHANGE ADSORPTION EQUILIBRIA OF AMMONIUM ON CATION-VERMICULITE MINERALS

    Institute of Scientific and Technical Information of China (English)

    GUO Yaping; XIE Lianwu; WU Xiaofu

    2006-01-01

    Experiment was designed under different pH and temperature conditions to analysis the NH4+ exchange capacity of Na+-vermiculite, Ca2+-vermiculite and Mg2+-vermiculite clay minerals pre-treated using NaCl, CaCl2 and MgCl2 solutions respectively. The results indicated that the exchange reactions occurred most rapidly at the proceeding 80 minutes and approached to equilibrium by about 120 minutes. The exchange quantity of ammonium on the vermiculite (at initial ammonium concentration of 673mg/L ) varied with pH with a peak value of 28.36mg/g on Na+-vermiculite, 23.01mg/g on Ca2+-vermiculite, 20.14mg/g on Mg2+-vermiculite, 18.04mg/g on natural vermiculite at pH 7. The exchange and adsorption isotherm of NH4+ on cation-vermiculite can be described by Langmuir equation.

  6. Porphyrin Analogues of a Trityl Cation and Anion.

    Science.gov (United States)

    Kato, Kenichi; Kim, Woojae; Kim, Dongho; Yorimitsu, Hideki; Osuka, Atsuhiro

    2016-05-17

    Porphyrin-stabilized meso- or β-carbocations were generated upon treatment of the corresponding bis(4-tert-butylphenyl)porphyrinylcarbinols with trifluoroacetic acid (TFA). Bis(4-tert-butylphenyl)porphyrinylcarbinols were treated with TFA to generate the corresponding carbocations stabilized by a meso- or β-porphyrinyl group. The meso-porphyrinylmethyl carbocation displayed more effective charge delocalization with decreasing aromaticity compared with the β-porphyrinylmethyl carbocation. A propeller-like porphyrin trimer, tris(β-porphyrinyl)carbinol, was also synthesized and converted to the corresponding cation that displayed a more intensified absorption reaching over the NIR region. meso-Porphyrinylmethyl carbanion was generated as a stable species upon deprotonation of bis(4-tert-butylphenyl)(meso-porphyrinyl)methane with potassium bis(trimethylsilyl)amide (KHMDS) and [18]crown-6, whereas β-porphyrinylmethyl anions were highly unstable. PMID:26991021

  7. Study on synthesis and flocculation property of cation-polyacrylamide

    Institute of Scientific and Technical Information of China (English)

    NIE Rong-chun; GUO Li-ying; XU Chu-yang

    2008-01-01

    On the basis of flocculating settling experimentation on flotation waste coal in Wangfenggang coal preparation plant, influence of medical dosage and cationization (CD) of CPAM samples on coal slurry's flocculating effect was studied, difference of flocculating effect on coal slurry among different categories of polyacrylamide was discussed. Experi-mental results show that when the dosage of flocculant reaches 2~4 g/m3 flotation waste,and the CD of CPAM is 5%, flocculating effect is the best, light transmittance of super-natant liquor reaches 93%. Taking 3types of sample CPAM, PAM and PHP, which formula weight vary a little, to deal with the same concn of coal slurry, when medicine dosage is 3 g/m3, flocculating effect of CPAM is the best, light transmittance of supernatant liquor reaches 92%.

  8. Organic non-aqueous cation-based redox flow batteries

    Energy Technology Data Exchange (ETDEWEB)

    Jansen, Andrew N.; Vaughey, John T.; Chen, Zonghai; Zhang, Lu; Brushett, Fikile R.

    2016-03-29

    The present invention provides a non-aqueous redox flow battery comprising a negative electrode immersed in a non-aqueous liquid negative electrolyte, a positive electrode immersed in a non-aqueous liquid positive electrolyte, and a cation-permeable separator (e.g., a porous membrane, film, sheet, or panel) between the negative electrolyte from the positive electrolyte. During charging and discharging, the electrolytes are circulated over their respective electrodes. The electrolytes each comprise an electrolyte salt (e.g., a lithium or sodium salt), a transition-metal free redox reactant, and optionally an electrochemically stable organic solvent. Each redox reactant is selected from an organic compound comprising a conjugated unsaturated moiety, a boron cluster compound, and a combination thereof. The organic redox reactant of the positive electrolyte is selected to have a higher redox potential than the redox reactant of the negative electrolyte.

  9. Supramolecular Explorations: Exhibiting the Extent of Extended Cationic Cyclophanes.

    Science.gov (United States)

    Dale, Edward J; Vermeulen, Nicolaas A; Juríček, Michal; Barnes, Jonathan C; Young, Ryan M; Wasielewski, Michael R; Stoddart, J Fraser

    2016-02-16

    Acting as hosts, cationic cyclophanes, consisting of π-electron-poor bipyridinium units, are capable of entering into strong donor-acceptor interactions to form host-guest complexes with various guests when the size and electronic constitution are appropriately matched. A synthetic protocol has been developed that utilizes catalytic quantities of tetrabutylammonium iodide to make a wide variety of cationic pyridinium-based cyclophanes in a quick and easy manner. Members of this class of cationic cyclophanes with boxlike geometries, dubbed Ex(n)Boxm(4+) for short, have been prepared by altering a number of variables: (i) n, the number of "horizontal" p-phenylene spacers between adjoining pyridinium units, to modulate the "length" of the cavity; (ii) m, the number of "vertical" p-phenylene spacers, to modulate the "width" of the cavity; and (iii) the aromatic linkers, namely, 1,4-di- and 1,3,5-trisubstituted units for the construction of macrocycles (ExBoxes) and macrobicycles (ExCages), respectively. This Account serves as an exploration of the properties that emerge from these structural modifications of the pyridinium-based hosts, coupled with a call for further investigation into the wealth of properties inherent in this class of compounds. By variation of only the aforementioned components, the role of these cationic receptors covers ground that spans (i) synthetic methodology, (ii) extraction and sequestration, (iii) catalysis, (iv) molecular electronics, (v) physical organic chemistry, and (vi) supramolecular chemistry. Ex(1)Box(4+) (or simply ExBox(4+)) has been shown to be a multipurpose receptor capable of binding a wide range of polycyclic aromatic hydrocarbons (PAHs), while also being a suitable component in switchable mechanically interlocked molecules. Additionally, the electronic properties of some host-guest complexes allow the development of artificial photosystems. Ex(2)Box(4+) boasts the ability to bind both π-electron-rich and -poor aromatic

  10. Aqueous behaviour of cationic surfactants containing a cleavable group.

    Science.gov (United States)

    Samakande, Austin; Chaghi, Radhouane; Derrien, Gaelle; Charnay, Clarence; Hartmann, Patrice C

    2008-04-01

    The aggregation behaviour of two novel cationic RAFT agents (transfer surfactants); N,N-dimethyl-N-(4-(((phenylcarbonothioyl)thio)methyl)benzyl)ethanammonium bromide (PCDBAB) and N-(4-((((dodecylthio)-carbonothioyl)thio)methyl)benzyl)-N,N-dimethylethanammonium bromide (DCTBAB) in diluted solutions have been investigated by surface tension, conductimetry and microcalorimetry measurements. The thermodynamic parameters i.e. the critical micelle concentration (cmc), the degree of micelle ionization (alpha), the head group surface area (a 0), Delta H mic, Delta G mic and T Delta S mic are reported at 303 K. The thermodynamic parameters have been compared to those of the conventional surfactant cetyltrimethylammonium bromide (CTAB) in order to specify structural relationships. The obtained results have been discussed considering the hydrophobic behaviour of the S-C=S- linkage and the specific interactions that arise from the introduction of the benzene ring into the hydrophobic part.

  11. Dilution thermodynamics of the biologically relevant cation mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Kaczyński, Marek, E-mail: marek.kaczynski@pwr.wroc.pl; Borowik, Tomasz, E-mail: office@novel-id.pl; Przybyło, Magda, E-mail: magdalena.przybylo@pwr.wroc.pl; Langner, Marek, E-mail: marek.langner@pwr.wroc.pl

    2014-01-10

    Graphical abstract: - Highlights: • Dilution energetics of Ca{sup 2+} can be altered by the aqueous phase ionic composition. • Dissipated heat upon Ca{sup 2+} dilution is drastically reduced in the K{sup +} presence. • Reduction of the enthalpy change upon Ca{sup 2+} dilution is K{sup +} concentration dependent. • The cooperativity of Ca{sup 2+} hydration might be of great biological relevance providing a thermodynamic argument for the specific ionic composition of the intracellular environment. - Abstract: The ionic composition of intracellular space is rigorously controlled by a variety of processes consuming large quantities of energy. Since the energetic efficiency is an important evolutional criterion, therefore the ion fluxes within the cell should be optimized with respect to the accompanying energy consumption. In the paper we present the experimental evidence that the dilution enthalpies of the biologically relevant ions; i.e. calcium and magnesium depend on the presence of monovalent cations; i.e. sodium and potassium. The heat flow generated during the dilution of ionic mixtures was measured with the isothermal titration calorimetry. When calcium was diluted together with potassium the dilution enthalpy was drastically reduced as the function of the potassium concentration present in the solution. No such effect was observed when the potassium ions were substituted with sodium ones. When the dilution of magnesium was investigated the dependence of the dilution enthalpy on the accompanying monovalent cation was much weaker. In order to interpret experimental evidences the ionic cluster formation is postulated. The specific organization of such cluster should depend on ions charges, sizes and organization of the hydration layers.

  12. Understanding electrochromic processes initiated by dithienylcyclopentene cation-radicals.

    Science.gov (United States)

    Guirado, Gonzalo; Coudret, Christophe; Hliwa, Mohamed; Launay, Jean-Pierre

    2005-09-22

    Simple photochromic dithienylethylenes with either a perfluoro or a perhydro cyclopentene ring, and a variety of substituents (chlorine, iodine, trimethylsilyl, phenylthio, aldehyde, carboxylic acid, and ethynylanisyl), have been prepared and their electrochemical behavior was explored by cyclic voltammetry. All dithienylethylenes present two-electron irreversible oxidation waves in their open form, but the cation-radical of the open isomers can follow two different reaction pathways: dimerization or ring closure, whereas the halogen derivatives follow a dimerization mechanism, the presence of donor groups, such as the phenylthio-substituted compound, promote an efficient oxidative ring closure following an ECE/DISP mechanism. Electrochromic properties are also found in the corresponding ring-closed isomers. Depending on the substituents on the thiophene ring, and the perfluro or perhydro cyclopentene ring, open isomers can be obtained from oxidation (chemical or electrochemical) of the corresponding ring-closed isomers via an EC mechanism. This reaction pathway is favored by the presence of electron-withdrawing groups in the molecule. For all these compounds, closed or open, the oxidation lies between 0.8 and 1.5 V vs SCE, and provokes a permanent modification of the color, even after an oxidation-reduction cycle. This could be qualified as "electrochromism with memory". On the other hand, the ring-closed electron-rich isomers (E degrees electrochromism", for which no structural changes are observed. The experimental study was completed by theoretical calculations at the DFT level, using B3LYP density functional, which gave information on the total energy, the geometry, and the electronic structures of several representative compounds, either in the neutral form or in the cation-radical state. These results are important for the potential design of photochromic systems, such as three-state conjugated systems and photoelectrical molecular switching devices. PMID

  13. Non-Surface Activity of Cationic Amphiphilic Diblock Copolymers

    Energy Technology Data Exchange (ETDEWEB)

    Nayak, Rati Ranjan; Yamada, Tasuku; Matsuoka, Hideki, E-mail: ratiranjan@immt.res.in, E-mail: matsuoka@star.polym.kyoto-u.ac.jp [Department of Polymer Chemistry, Graduate School of Engineering, Kyoto University, Nishikyo-ku, Kyoto 615-8510 (Japan)

    2011-09-19

    Cationic amphiphilic diblock copolymers containing quaternized poly (2-vinylpyridine) chain as a hydrophilic segment (PIp-b-PNMe2VP) were synthesized by living anionic polymerization. By IR measurement, we confirmed the quaternization of the polymer (PIp-b-PNMe2VP), and determined the degree of quaternization by conductometric titration. The surface tension experiment showed that the polymers are non-surface active in nature. The foam formation of the polymer solutions was also investigated with or without added salt. Almost no foam formation behavior was observed without added salt, while a little foam was observed in the presence of 1M NaCl. The critical micelle concentration (cmc) of the diblock copolymers with 3 different chain lengths was measured by the static light scattering method. The cmc values obtained in this study were much lower than the values obtained for anionic non-surface active diblock polymers studied previously. The hydrodynamic radii of the polymer micelle increased slightly in the presence of 1 M NaCl. The transmission electron microscopic images revealed spherical micelles in pure water. In the presence of salt, the cmc values increased as was the case for anionic polymers, which is unlike conventional surfactant systems but consistent with non-surface active anionic block copolymers. The microviscosity of the micelle core was evaluated using Coumarin-153 as a fluorescent anisotropy probe using steady-sate fluorescence depolarization. Non-surface activity has been proved to be universal for ionic amphiphilic block copolymers both for anionic and cationic. Hence, the origin of non-surface activity is not the charged state of water surface itself, but should be an image charge repulsion at the air/water interface.

  14. Helicobacter pylori Outer Membrane Vesicle Proteins Induce Human Eosinophil Degranulation via a β2 Integrin CD11/CD18- and ICAM-1-Dependent Mechanism

    Directory of Open Access Journals (Sweden)

    Su Hyuk Ko

    2015-01-01

    Full Text Available Eosinophil cationic protein (ECP, a cytotoxic protein contained in eosinophils granules, can contribute to various inflammatory responses. Although Helicobacter pylori infection increases infiltration of eosinophils, the mechanisms of eosinophil degranulation by H. pylori infection are largely unknown. The goal of this study was to investigate the role of H. pylori outer membrane vesicles (OMVs in modulating eosinophil degranulation. We found that eosinophils treated with H. pylori OMVs released significantly more ECP compared with untreated controls. In addition, eosinophils cocultured with OMV-preexposed primary gastric epithelial cells exhibited significantly increased ECP release. Similarly, eosinophils cocultured with culture supernatant (CM from primary gastric epithelial cells exposed to OMVs (OMV-CM released significantly higher amounts of ECP compared with eosinophils cocultured with CM from unexposed control cells. Furthermore, OMVs and OMV-CM both induced the upregulation of ICAM-1 on gastric epithelial cells and β2 integrin CD11b on eosinophils. In addition, both transduction of ICAM-1 shRNA into gastric epithelial cells and treatment with neutralizing mAbs to CD18 significantly decreased OMV-mediated or OMV-CM-mediated release of ECP. These results suggest that the eosinophil degranulation response to H. pylori OMVs occurs via a mechanism that is dependent on both β2 integrin CD11/CD18 and ICAM-1.

  15. Experimental Study on Apoptosis in Leukemia Cells Induced by Econazole

    Institute of Scientific and Technical Information of China (English)

    LIUFang; ZOUPing; ZHANGMin; WUYaohui; XIAOJuan

    2005-01-01

    Objective: To investigate apoptosis in monse leukemia cell (WEHI-3) induced by Econazole and its mechanisin. Methods: Apoptosis induced by Econazole was examined by flow cytometry. Free calcium ([Ca2+]i) was determined by Fura-2 fluorescein load technique. The protein was isolated from endoplasinic reticulum of WEHI-3 cells, and then the expression of caspase-12 and caspase-7 was detected by Western blot. Results: WEHI-3 cells exhibited typical change of apoptosis when they were treated by Econazole.[Ca2+]i was significantly higher in Econazole-treated group t han in control group. The expression of caspase-12 and caspase-7 was increased with the increase of Econazole concentration. Conclusion: Caspase-12 may play a key role in WEHI-3 apoptosis induced by Econazole.

  16. Apoptosis and the target genes of microRNA-21

    Institute of Scientific and Technical Information of China (English)

    Lindsey E. Becker Buscaglia; Yong Li

    2011-01-01

    MicroRNA-21 (miR-21) is frequently up-regulated in cancer and the majodty of its reported targets are tumor suppressors. Through functional suppression, miR-21 is implicated in practically every walk of oncogenic life: the promotion of cell proliferation, invasion and metastasis, genome instability and mutation, inflammation, replicative immortalization, abnormal metabolism, angiogenesis, and evading apoptosis, immune destruction, and growth suppressors. In particular, miR-21 is strongly involved in apoptosis. In this article, we reviewed the experimentally validated targets of miR-21 and found that two thirds are linked to intrinsic and/or extrinsic pathways of cellular apoptosis. This suggests that miR-21 is an oncogene which plays a key role in resisting programmed cell death in cancer cells and that targeting apoptosis is a viable therapeutic option against cancers expressing miR-21.

  17. Transcriptional profiling of apoptosis-deficient Drosophila mutants

    Directory of Open Access Journals (Sweden)

    Fumiaki Obata

    2014-12-01

    Full Text Available Apoptosis is a fundamental way to remove damaged or unwanted cells during both developmental and post-developmental stages. Apoptosis deficiency leads to various diseases including cancer. To know the physiological changes in apoptosis-deficient mutants, we conducted non-biased transcriptomic analysis of Drosophila darkcd4 mutants. As recently reported, combined with metabolome and genetic analysis, we identified systemic immune response, energy wasting, as well as alteration in S-adenosyl-methionine metabolism in response to necrotic cells [1]. Here, we describe in detail how we obtained validated microarray dataset deposited in Gene Expression Omnibus (GSE47853. Our data provide a resource for searching transcriptional alterations in Drosophila apoptosis-deficient mutants.

  18. ING1 induces apoptosis through direct effects at the mitochondria

    DEFF Research Database (Denmark)

    Bose, P; Thakur, S; Thalappilly, S;

    2013-01-01

    The ING family of tumor suppressors acts as readers and writers of the histone epigenetic code, affecting DNA repair, chromatin remodeling, cellular senescence, cell cycle regulation and apoptosis. The best characterized member of the ING family, ING1,interacts with the proliferating cell nuclear...... translocates to the mitochondria of primary fibroblasts and established epithelial cell lines in response to apoptosis inducing stimuli, independent of the cellular p53 status. The ability of ING1 to induce apoptosis in various breast cancer cell lines correlates well with its degree of translocation...... to the mitochondria after UV treatment. Endogenous ING1 protein specifically interacts with the pro-apoptotic BCL2 family member BAX, and colocalizes with BAX in a UV-inducible manner. Ectopic expression of a mitochondria-targeted ING1 construct is more proficient in inducing apoptosis than the wild type ING1 protein...

  19. Accelerated apoptosis of neutrophils in familial Mediterranean fever

    DEFF Research Database (Denmark)

    Manukyan, Gayane; Aminov, Rustam; Hakobyan, Gagik;

    2015-01-01

    The causative mutations for familial Mediterranean fever (FMF) are located in the MEFV gene, which encodes pyrin. Pyrin modulates the susceptibility to apoptosis via its PYD domain, but how the mutated versions of pyrin affect apoptotic processes are poorly understood. Spontaneous and induced rates...... of systemic neutrophil apoptosis as well as the levels of proteins involved in apoptosis were investigated ex vivo in patients with FMF using flow cytometry and RT-qPCR. The freshly collected neutrophils from the patients in FMF remission displayed a significantly larger number of cells spontaneously entering...... apoptosis compared to control (6.27 ± 2.14 vs. 1.69 ± 0.18%). This elevated ratio was retained after 24 h incubation of neutrophils in the growth medium (32.4 ± 7.41 vs. 7.65 ± 1.32%). Correspondingly, the mRNA level for caspase-3 was also significantly increased under these conditions. In response...

  20. Effect of Celecoxib on Apoptosis of Endometrial Carcinoma Cell

    Institute of Scientific and Technical Information of China (English)

    SHENG Xiu-jie; FANG Zhao

    2007-01-01

    Objective: To investigate the effect of Celecoxib on proliferation and apoptosis of the endometrial carcinoma cell HEC-1B and the effect on the expression of Fas and Survivin mRNA. Methods: The inhibition on the growth of human endometrial carcinoma cell HEC-1B was investigated by cell culture and MTT experiment when treated with different concentrations of Celecoxib. The cell apoptosis was detected by flow cytometry and DNA Ladder Electrophoresis. The change of the expression of Fas and Survivin mRNA after the treatment of Celecoxib was detected With RT-PCR. Results: Celecoxib could effectively inhibit the growth of HEC-1B cells and induce apoptosis. Survivin mRNA expression was decreased and Fas mRNA expression was increased after treating with Celecoxib. Conclusion: Celecoxib could inhibit HEC-1B cell proliferation and induce its apoptosis.

  1. Nosema Tolerant Honeybees (Apis mellifera) Escape Parasitic Manipulation of Apoptosis

    DEFF Research Database (Denmark)

    Kurze, Christoph; Le Conte, Yves; Dussaubat, Claudia;

    2015-01-01

    Apoptosis is not only pivotal for development, but also for pathogen defence in multicellular organisms. Although numerous intracellular pathogens are known to interfere with the host’s apoptotic machinery to overcome this defence, its importance for host-parasite coevolution has been neglected. We...... apoptotic processes in the gut epithelium, we visualised apoptotic cells using TUNEL assays and measured the relative expression levels of subset of candidate genes involved in the apoptotic machinery using qPCR. Our results suggest that N. ceranae reduces apoptosis in sensitive honeybees by enhancing...... inhibitor of apoptosis protein-(iap)-2 gene transcription. Interestingly, this seems not be the case in Nosema tolerant honeybees. We propose that these tolerant honeybees are able to escape the manipulation of apoptosis by N. ceranae, which may have evolved a mechanism to regulate an anti-apoptotic gene...

  2. Induction of Apoptosis by Hypertension Via Endoplasmic Reticulum Stress

    Directory of Open Access Journals (Sweden)

    Yingying Sun

    2015-02-01

    Full Text Available Background/Aims: Endoplasmic reticulum (ER stress is one of the intrinsic apoptosis pathways, and cardiac apoptosis can occur in cardiovascular diseases, such as hypertension. However, the mechanisms by which ER stress leads to apoptosis remain enigmatic, particularly in the progression from cardiac hypertrophy to diastolic heart failure due to hypertension. Methods: We used spontaneously hypertensive rats (SHRs to investigate possible signalling pathways for ER stress. Results: We found that cardiac protein and mRNA levels of glucose-regulated protein 78 were up-regulated. In addition, the CHOP- and caspase-12-dependent pathways, but not that of JNK, were activated in the SHR rats. Conclusions: These results suggest that ER stress can contribute to myocardial apoptosis during hypertensive disease.

  3. The effect of cation source and dietary cation-anion difference on rumen ion concentrations in lactating dairy cows.

    Science.gov (United States)

    Catterton, T L; Erdman, R A

    2016-08-01

    Many studies have focused on the influence of dietary cation-anion difference (DCAD) on animal performance but few have examined the effect of DCAD on the rumen ionic environment. The objective of this study was to examine the effects of DCAD, cation source (Na vs. K), and anion source (Cl vs. bicarbonate or carbonate) on rumen environment and fermentation. The study used 5 rumen-fistulated dairy cows and 5 dietary treatments that were applied using a 5×5 Latin square design with 2-wk experimental periods. Treatments consisted of (1) the basal total mixed ration (TMR); (2) the basal TMR plus 340mEq/kg of Na (dry matter basis) using NaCl; (3) the basal TMR plus 340mEq/kg of K using KCl; (4) the basal TMR plus 340mEq/kg of Na using NaHCO3; and (5) the basal TMR plus 340mEq/kg of K using K2CO3. On the last day of each experimental period, rumen samples were collected and pooled from 5 different locations at 0, 1.5, 3, 4.5, 6, 9, and 12h postfeeding for measurement of rumen pH and concentrations of strong ions and volatile fatty acids (VFA). Dietary supplementation of individual strong ions increased the corresponding rumen ion concentration. Rumen Na was decreased by 24mEq/L when K was substituted for Na in the diet, but added dietary Na had no effect on rumen K. Rumen Cl was increased by 10mEq/L in diets supplemented with Cl. Cation source had no effect on rumen pH or total VFA concentration. Increased DCAD increased rumen pH by 0.10 pH units and increased rumen acetate by 4mEq/L but did not increase total VFA. This study demonstrated that rumen ion concentrations can be manipulated by dietary ion concentrations. If production and feed efficiency responses to DCAD and ionophores in the diet are affected by rumen Na and K concentrations, then manipulating dietary Na and K could be used either to enhance or diminish those responses. PMID:27289159

  4. Visualizing Vpr-induced G2 arrest and apoptosis.

    Directory of Open Access Journals (Sweden)

    Tomoyuki Murakami

    Full Text Available Vpr is an accessory protein of human immunodeficiency virus type 1 (HIV-1 with multiple functions. The induction of G2 arrest by Vpr plays a particularly important role in efficient viral replication because the transcriptional activity of the HIV-1 long terminal repeat is most active in G2 phase. The regulation of apoptosis by Vpr is also important for immune suppression and pathogenesis during HIV infection. However, it is not known whether Vpr-induced apoptosis depends on the ability of Vpr to induce G2 arrest, and the dynamics of Vpr-induced G2 arrest and apoptosis have not been visualized. We performed time-lapse imaging to examine the temporal relationship between Vpr-induced G2 arrest and apoptosis using HeLa cells containing the fluorescent ubiquitination-based cell cycle indicator2 (Fucci2. The dynamics of G2 arrest and subsequent long-term mitotic cell rounding in cells transfected with the Vpr-expression vector were visualized. These cells underwent nuclear mis-segregation after prolonged mitotic processes and then entered G1 phase. Some cells subsequently displayed evidence of apoptosis after prolonged mitotic processes and nuclear mis-segregation. Interestingly, Vpr-induced apoptosis was seldom observed in S or G2 phase. Likewise, visualization of synchronized HeLa/Fucci2 cells infected with an adenoviral vector expressing Vpr clearly showed that Vpr arrests the cell cycle at G2 phase, but does not induce apoptosis at S or G2 phase. Furthermore, time-lapse imaging of HeLa/Fucci2 cells expressing SCAT3.1, a caspase-3-sensitive fusion protein, clearly demonstrated that Vpr induces caspase-3-dependent apoptosis. Finally, to examine whether the effects of Vpr on G2 arrest and apoptosis were reversible, we performed live-cell imaging of a destabilizing domain fusion Vpr, which enabled rapid stabilization and destabilization by Shield1. The effects of Vpr on G2 arrest and subsequent apoptosis were reversible. This study is the first to

  5. APOPTOSIS INDUCTION BY THE RECOMBINANT FUSION APOPTOSIS INDUCING FACTOR ON HELA CELLS

    Institute of Scientific and Technical Information of China (English)

    于翠娟; 孟艳玲; 桂俊豪; 赵晶; 金明; 王智; 王成济; 杨安钢

    2003-01-01

    Objective: To obtain the recombinant fusion AIF genes inserted into the eukaryotic expression vector Pires2-EGFP, to observe the expression and location of the fusion AIF genes (3NE: PE(280-358)-AIFΔ1-120, and 4NE: PE(280-364)-AIFΔ1-120), and to detect and compare their apoptosis inducing effects on the transfected HeLa cells. Methods: Full-length human AIF gene was cloned by RT-PCR, and its N-terminal mitochondrial localization sequence (MLS) was replaced by part sequence of Psuedomonas exotoxin A (PE) translocation domain (PEII(280-358/364)), then the recombinant fusion genes were inserted into the Pires2-EGFP eukaryotic expression vector. After these genes were transiently transfected into HeLa cells with LipofectAmine, the expression of the recombinant fusion AIF genes and their effects on HeLa cells were detected by fluorescent microscopy, laser confocal microscopy and electron microscopy. Results: The eukaryotic expression vectors containing the recombinant fusion AIF genes (Pires2-EGFP-PEII(280-358/364)- AIFΔ1- 120) were constructed successfully. It was demonstrated that the fusion AIF protein genes were expressed effectively in the transfected cells, with the GFP comco-expressed in cells by indirect immunofluorescence staining analysis. After transfection, expression of the genes could induce HeLa cells to exhibit the typical apoptosis features: such as plasma membrane blebbing and peripheral chromatin condensation. As compared with control groups, the untreated cells and the void vector transfected cells, the living cell number of the AIF gene transfected cells reduced distinctly. Conclusion: Our data prove that the expression of the recombinant human AIF fusion genes could induce apoptosis in transfected HeLa cells, which provides new strategy for cancer killing.

  6. Accelerated Apoptosis Contributes to Aging-Related Hyperinflammation in Endotoxemia

    OpenAIRE

    Zhou, Mian; Wu, Rongqian; Dong, Weifeng; Leong, Jennifer; Ping WANG

    2010-01-01

    Sepsis is associated with an increase in circulating levels of bacterial endotoxin. Sepsis is a particularly serious problem in the geriatric population due to the high mortality associated with it. However, it remains unknown whether this phenomenon is related to an increase of apoptosis in splenic cells. To study this, male Fischer-344 rats (young: 3-months old; aged: 24-months old) were subjected to endotoxemia by injection of LPS. Splenic samples were collected 4 h thereafter. Apoptosis w...

  7. Cerebral ischemia—induced neuronal apoptosis mediated by nitric oxide

    Institute of Scientific and Technical Information of China (English)

    NomuY

    2002-01-01

    To elucidate the cellular and molecular mechanism of cerebral ischemia-induced neuronal apoptosis mediated by nitric oxide (NO) in the brain,we investigated:(1)cell death in hippocampal CA1 neurons of rats after a rransient four vessel occlusion (4VO)/reperfusion and (2) apoptosis induced by NOC18(NO releaser) using SHSY5Y cells,a human neuroblastoma cell line.We found that 4VO caused expression of inducible type of NO synthase (iNOS) in glial cells and neuronal apoptosis in CA1 region of rats.Next we examined in vitro apoptotic effects of NOC18 on SHSY5Y cells and suggest that NO decrease mitochondrial membrane potential,release cytochrome C from mitochondria,activates caspase-3,degrade inhibitor of caspase-activated DNase(Icad),and activated DNase translocate into nucleus and induce DNA fragmentation.Thus we conclude that the excess amount of NO produced by glial iNOS at cerebral ischemia could be involved in neuronal apoptosis in CA1 region.Regarding NO action on neurons,we further obtained that NO propects neuronal apoptosis in PC12 cells perhaps by nitrosylation of caspase,subsequent reduction of proteolytic activity.Taken together,we suggest that NO seem to exert dual effects(toxic and beneficial) on neuronal apoptosis,the one (toxic);apoptosis-induction throuth the decrease in mitochondrial membrane potentials and cytochrome C release and the othe (beneficial);protection against apoptosis through the inhibition of caspase activity.

  8. Apoptosis of human primary gastric carcinoma cells induced by genistein

    Institute of Scientific and Technical Information of China (English)

    Hai-Bo Zhou; Juan-Juan Chen; Wen-Xia Wang; Jian-Ting Cai; Qin Du

    2004-01-01

    AIM: To investigate the apoptosis in primary gastric cancer cells induced by genistein, and the relationship between this apoptosis and expression of bcl-2 and bax.METHODS: MTT assay was used to determine the cell growth inhibitory rate in vitro. Transmission electron microscope and TUNEL staining were used to quantitatively and qualitatively detect the apoptosis of primary gastric cancer cells before and after genistein treatment. Immunohistochemical staining and RT-PCR were used to detect the expression of apoptosisassociated genes bcl-2 and bax.RESULTS: Genistein inhibited the growth of primary gastric cancer cells in dose-and time-dependent manner. Genistein induced primary gastric cancer cells to undergo apoptosis with typically apoptotic characteristics. TUNEL assay showed that after the treatment of primary gastric cancer cells with genistein for 24 to 96 h, the apoptotic rates of primary gastric cancer cells increased time-dependently. Immunohistochemical staining showed that after the treatment of primary gastric cancer cells with genistein for 24 to 96 h, the positivity rates of Bcl-2 proteins were apparently reduced with time and the positivity rates of Bax proteins were apparently increased with time. After exposed to genistein at 20 μmol/L for 24,48, 72 and 96 respectively, the density of bcl-2 mRNA decreased progressively and the density of bax mRNA increased progressively with elongation of time.CONCLUSION: Genistein is able to induce the apoptosis in primary gastric cancer cells. This apoptosis may be mediated by down-regulating the apoptosis- associated bcl-2 gene and up-regulating the expression of apoptosis-associated bax gene.

  9. Induction of apoptosis in frog virus 3-infected cells.

    Science.gov (United States)

    Chinchar, V G; Bryan, Locke; Wang, J; Long, Scott; Chinchar, G D

    2003-02-15

    The ability of frog virus 3 (FV3), the type species of the family Iridoviridae, to induce apoptosis was examined by monitoring DNA cleavage, chromatin condensation, and cell-surface expression of phosphotidylserine (PS) in fathead minnow (FHM) and baby hamster kidney (BHK) cells. In productively infected FHM cells, DNA fragmentation was first noted at 6-7 h postinfection and was clearly seen by 17 h postinfection, while chromatin condensation was detected at 8.5 h postinfection. As with some other viruses, FV3-induced apoptosis did not require de novo viral gene expression as both heat-inactivated and UV-inactivated virus readily triggered DNA fragmentation in FHM cells. Moreover, FV3-induced apoptosis was blocked in FHM cells by the pan-caspase inhibitor Z-VAD-FMK, suggesting that virus infection triggers programmed cell death through activation of the caspase cascade. FV3 infection also triggered apoptosis in BHK cells as monitored by TUNEL and annexin V binding assays. To determine whether FV3, similar to other large DNA viruses, encoded proteins that block or delay apoptosis, mock- and FV3-infected FHM cells were osmotically shocked and assayed for DNA fragmentation 3 hours later. DNA fragmentation was clearly seen whether or not shocked cells were previously infected with FV3, indicating that infection with FV3 did not block apoptosis induced by osmotic shock in FHM cells. The above results demonstrate that iridoviruses triggered apoptosis and that the induction of programmed cell death did not require viral gene expression. However, it remains to be determined if virion attachment to target cells is sufficient to induce cell death, or if apoptosis is triggered directly or indirectly by one or more virion-associated proteins. PMID:12642103

  10. Neuronal apoptosis in morphine addiction and its molecular mechanism

    OpenAIRE

    Liu, Li-wei; Lu, Jun; Wang, Xin-Hua; Fu, Shu-kun; Li, Quan; Lin, Fu-qing

    2013-01-01

    Objective: This study aimed to investigate neuronal apoptosis and expression of apoptosis related proteins (Fas, Caspase-3 and Bcl-2) in the brain of rates with morphine addiction. Methods: A total of 48 adult male Sprague-Dawley rats weighing 190-210 g were randomly divided into 3 groups (n=16 per group): morphine addiction group, morphine abstinence group and control group. Rats in the addiction group and the abstinence group were intraperitoneally treated with morphine for 13 days to induc...

  11. Peptides Regulate Cortical Thymocytes Differentiation, Proliferation, and Apoptosis

    Directory of Open Access Journals (Sweden)

    V. Kh. Khavinson

    2011-01-01

    Full Text Available The processes of differentiation, proliferation, and apoptosis were studied in a cell culture of human cortical thymocytes under the influence of short peptides T-32 (Glu-Asp-Ala and T-38 (Lys-Glu-Asp. Peptides T-32 and T-38 amplified cortical thymocytes differentiation towards regulatory T cells, increased their proliferative activity, and decreased the level of apoptosis. Moreover, peptides under study stimulated proliferative and antiapoptotic activity of the mature regulatory T cells.

  12. A feedback control perspective on models of apoptosis signal transduction

    International Nuclear Information System (INIS)

    Apoptosis is a key regulator for replacing unused, old and damaged cells. Here we analyse three models of apoptosis. We deconstruct these models by linearising the models about the life steady state and applying methods from linear control theory. This control viewpoint uncovers a decentralised control scheme with a clear separation of plant and controller and reveals that the caspase inhibitors act as decentralised phase lead controllers

  13. Social apoptosis in honey bee superorganisms.

    Science.gov (United States)

    Page, Paul; Lin, Zheguang; Buawangpong, Ninat; Zheng, Huoqing; Hu, Fuliang; Neumann, Peter; Chantawannakul, Panuwan; Dietemann, Vincent

    2016-01-01

    Eusocial insect colonies form superorganisms, in which nestmates cooperate and use social immunity to combat parasites. However, social immunity may fail in case of emerging diseases. This is the case for the ectoparasitic mite Varroa destructor, which switched hosts from the Eastern honeybee, Apis cerana, to the Western honey bee, Apis mellifera, and currently is the greatest threat to A. mellifera apiculture globally. Here, we show that immature workers of the mite's original host, A. cerana, are more susceptible to V. destructor infestations than those of its new host, thereby enabling more efficient social immunity and contributing to colony survival. This counterintuitive result shows that susceptible individuals can foster superorganism survival, offering empirical support to theoretical arguments about the adaptive value of worker suicide in social insects. Altruistic suicide of immature bees constitutes a social analogue of apoptosis, as it prevents the spread of infections by sacrificing parts of the whole organism, and unveils a novel form of transgenerational social immunity in honey bees. Taking into account the key role of susceptible immature bees in social immunity will improve breeding efforts to mitigate the unsustainably high colony losses of Western honey bees due to V. destructor infestations worldwide. PMID:27264643

  14. Tributyltin stimulates apoptosis in rat thymocytes.

    Science.gov (United States)

    Aw, T Y; Nicotera, P; Manzo, L; Orrenius, S

    1990-11-15

    Treatment of rat thymocytes with micromolar concentrations of tributyltin caused a rapid increase in the cytosolic free Ca2+ concentration that was inhibited by Ni2+, which blocks Ca2+ influx through membrane channels. The elevation of cytosolic Ca2+ was associated with extensive DNA fragmentation, which was prevented by pretreatment of the cells with either of the intracellular Ca2+ chelators quin-2 or 1,2-bis(2-amino-phenoxy)ethane-N',N',N',N',-tetraacetic acid. Loss of thymocyte viability, which followed DNA fragmentation, was also prevented by the two Ca2+ chelators or by removing extracellular Ca2+ with ethylene glycol bis(beta-aminoethyl ether)N,N'-tetraacetic acid. The pattern of DNA fragmentation was characteristic of that produced by agents which activate a Ca2(+)- and Mg2(+)-dependent endogenous endonuclease during apoptosis or programmed cell death. Additional studies showed that other organotin compounds, including trimethyltin, triphenyltin, and dibutyltin had minimal effects on cytosolic Ca2+, DNA fragmentation, and cell viability. These results are consistent with a greater susceptibility of thymocytes to tributyltin and provide a basis for understanding its selective immunotoxicity in vivo. PMID:2241174

  15. Coronavirus infection, ER stress and Apoptosis

    Directory of Open Access Journals (Sweden)

    TO SING eFUNG

    2014-06-01

    Full Text Available The replication of coronavirus, a family of important animal and human pathogens, is closely associated with the cellular membrane compartments, especially the endoplasmic reticulum (ER. Coronavirus infection of cultured cells was previously shown to cause ER stress and induce the unfolded protein response (UPR, a process that aims to restore the ER homeostasis by global translation shutdown and increasing the ER folding capacity. However under prolonged ER stress, UPR can also induce apoptotic cell death. Accumulating evidence from recent studies has shown that induction of ER stress and UPR may constitute a major aspect of coronavirus-host interaction. Activation of the three branches of UPR modulates a wide variety of signaling pathways, such as mitogen-activated protein (MAP kinases activation, autophagy, apoptosis and innate immune response. ER stress and UPR activation may therefore contribute significantly to the viral replication and pathogenesis during coronavirus infection. In this review, we summarize current knowledge on coronavirus-induced ER stress and UPR activation, with emphasis on their cross-talking to apoptotic signaling.

  16. Social apoptosis in honey bee superorganisms

    Science.gov (United States)

    Page, Paul; Lin, Zheguang; Buawangpong, Ninat; Zheng, Huoqing; Hu, Fuliang; Neumann, Peter; Chantawannakul, Panuwan; Dietemann, Vincent

    2016-01-01

    Eusocial insect colonies form superorganisms, in which nestmates cooperate and use social immunity to combat parasites. However, social immunity may fail in case of emerging diseases. This is the case for the ectoparasitic mite Varroa destructor, which switched hosts from the Eastern honeybee, Apis cerana, to the Western honey bee, Apis mellifera, and currently is the greatest threat to A. mellifera apiculture globally. Here, we show that immature workers of the mite’s original host, A. cerana, are more susceptible to V. destructor infestations than those of its new host, thereby enabling more efficient social immunity and contributing to colony survival. This counterintuitive result shows that susceptible individuals can foster superorganism survival, offering empirical support to theoretical arguments about the adaptive value of worker suicide in social insects. Altruistic suicide of immature bees constitutes a social analogue of apoptosis, as it prevents the spread of infections by sacrificing parts of the whole organism, and unveils a novel form of transgenerational social immunity in honey bees. Taking into account the key role of susceptible immature bees in social immunity will improve breeding efforts to mitigate the unsustainably high colony losses of Western honey bees due to V. destructor infestations worldwide. PMID:27264643

  17. Bisphenol A induces spermatocyte apoptosis in rare minnow Gobiocypris rarus.

    Science.gov (United States)

    Zhang, Yingying; Cheng, Mengqian; Wu, Lang; Zhang, Guo; Wang, Zaizhao

    2016-10-01

    Bisphenol A (BPA) is an endocrine disruptor, and could induce germ cells apoptosis in the testis of mammals. But whether it could affect fish in the same mechanism has not' been studied till now. In the present study, to investigate the influence of BPA on testis germ cells in fish, adult male rare minnow Gobiocypris rarus were exposed to 225μgL(-1) (0.99μM) BPA for 1, 3 and 9 weeks. Through TdT-mediated dUTP nick end labeling (TUNEL) and transmission electron microscope (TEM) analysis, we found that the amount of apoptotic spermatocytes significantly increased in a time dependent manner following BPA exposure. Western Blot results showed that the ratio of Bcl2/Bax, the important apoptosis regulators in intrinsic mitochondrial apoptotic pathway, was significantly decreased. qPCR showed that mRNA expression of several genes in mitochondrial apoptotic pathway including bcl2, bax, casp9, cytc and mcl1b were significantly changed following BPA exposure. In addition, mRNA expression of meiosis regulation genes (kpna7 and wee2), and genes involved in both apoptosis and meiosis (birc5, ccna1, and gsa1a) were also affected by BPA. Taken together, the present study demonstrated that BPA could induce spermatocytes apoptosis in rare minnow testis, and the apoptosis was probably under regulation of intrinsic mitochondrial apoptotic pathway. Moreover, the spermatocyte apoptosis was likely initiated by BPA induced meiosis arrest. PMID:27561114

  18. Detection of radiation-induced apoptosis using the comet assay

    International Nuclear Information System (INIS)

    The electrophoresis pattern of apoptotic cells detected by the comet assay has a characteristic small head and spread tail. This image has been referred to as an apoptotic comet, but it has not been previously proven to be apoptotic cells by any direct method. In order to identify this image obtained by the comet assay as corresponding to an apoptotic cell, the frequency of appearance of apoptosis was examined using CHO-K1 and L5178Y cells which were exposed to gamma irradiation. As a method for detecting apoptosis, the terminal deoxynucleotidyl transferase mediated dUTP nick end labeling (TUNEL) assay was used. When the frequency of appearance of apoptotic cells following gamma irradiation was observed over a period of time, there was a significant increase in appearance of apoptosis when using the TUNEL assay. However, there was only a slight increase when using the comet assay. In order to verify the low frequency of appearance of apoptosis when using the comet assay, we attempted to use the TUNEL assay to satin the apoptotic comets detected in the comet assay. The apoptotic comets were TUNEL positive and the normal comets were TUNEL negative. This indicates that the apoptotic comets were formed from DNA fragments with 3'-hydroxy ends that are generated as cells undergo apoptosis. Therefore, it was understood that the characteristic pattern of apoptotic comets detected by the comet assay corresponds to cells undergoing apoptosis. (author)

  19. Paclitaxel sensitizes gastric cancer cells to TRAIL-induced apoptosis

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    Objective:Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) holds promise for cancer therapy as it has unique capacity to selectively trigger apoptosis in cancer cells. We reported here that paclitaxel sensitized gastric cancer cells to TRAIL-induced apoptosis.Methods: After drug exposure, apoptosis rate and caspase activation were examined. Various proteins were detected by western blot. Several interventions, including pharmacological inhibitors and siRNA transfection were used. hTe growth inhibition of tumors was evaluated in SGC-7901-implanted nude mice model.Results:We found gastric cancer cellsshowed a mixed response to TRAIL. Combined treatment with paclitaxel markedly enhanced TARIL-induced apoptosis in vitro and in vivo. The underlying mechanisms involved in synergistical activation of caspase proteins, up-regulation of receptors, down-regulation of antiapoptotic proteins and inactivation of MAPKs.Conclusion:TRAIL-induced cytotoxicity and apoptosis can be synergistically enhanced by paclitaxel, suggesting the therapeutic potential of combining TARIL plus paclitaxel in gastric cancer treatment.

  20. Differential Apoptosis Radiosensitivity of Neural Progenitors in Adult Mouse Hippocampus

    Directory of Open Access Journals (Sweden)

    Yu-Qing Li

    2016-06-01

    Full Text Available Mammalian tissue-specific stem cells and progenitors demonstrate differential DNA damage response. Neural progenitors in dentate gyrus of the hippocampus are known to undergo apoptosis after irradiation. Using a mouse model of hippocampal neuronal development, we characterized the apoptosis sensitivity of the different neural progenitor subpopulations in adult mouse dentate gyrus after irradiation. Two different bromodeoxyuridine incorporation paradigms were used for cell fate mapping. We identified two apoptosis sensitive neural progenitor subpopulations after irradiation. The first represented non-proliferative and non-newborn neuroblasts and immature neurons that expressed doublecortin, calretinin or both. The second consisted of proliferative intermediate neural progenitors. The putative radial glia-like neural stem cells or type-1 cells, regardless of proliferation status, were apoptosis resistant after irradiation. There was no evidence of radiation-induced apoptosis in the absence of the Trp53 (p53 gene but absence of Cdkn1a (p21 did not alter the apoptotic response. Upregulation of nuclear p53 was observed in neuroblasts after irradiation. We conclude that adult hippocampal neural progenitors may demonstrate differential p53-dependent apoptosis sensitivity after irradiation.

  1. Cell Survival and Apoptosis Signaling as Therapeutic Target for Cancer: Marine Bioactive Compounds

    OpenAIRE

    Kim Se-Kwon; Senthilkumar Kalimuthu

    2013-01-01

    Inhibition of apoptosis leads to activation of cell survival factors (e.g., AKT) causes continuous cell proliferation in cancer. Apoptosis, the major form of cellular suicide, is central to various physiological processes and the maintenance of homeostasis in multicellular organisms. A number of discoveries have clarified the molecular mechanism of apoptosis, thus clarifying the link between apoptosis and cell survival factors, which has a therapeutic outcome. Induction of apoptosis and inhib...

  2. Ultrastructural study shows morphologic features of apoptosis and para-apoptosis in megakaryocytes from patients with idiopathic thrombocytopenic purpura

    NARCIS (Netherlands)

    Houwerzijl, EJ; Blom, NR; van der Want, JJL; Esselink, MT; Koornstra, JJ; Smit, JW; Louwes, H; Vellenga, E; de Wolf, JTM

    2004-01-01

    To investigate whether altered megakaryocyte morphology contributes to reduced platelet production in idiopathic thrombocytopenic purpura (ITP), ultrastructural analysis of megakaryocytes was performed in 11 ITP patients. Ultrastructural abnormalities compatible with (para-)apoptosis were present in

  3. The Expression of Apoptosis-Related Genes Bcl-2 and Bax Protein and Apoptosis Positivity in Cervical Carcinoma during Irradiation

    Institute of Scientific and Technical Information of China (English)

    ZHAODongli; SHIJingsen; LIMingzhong; SONGLiping; WANGShuwen

    2005-01-01

    Objective: To evaluate the apoptosis positivity, the expression of Bcl-2. bax proteins in 30 patients with squamous cell cervix carcinoma before and after radiotherapy. Methods: By using immunohistochemical and TDT-dUTP nick end labelling techniques. 30 cases of squamous cell cervical carcinoma were analyzed. Results: The apoptosis positivity before and after irradiation was 76.7%, and 100% respectively, with the difference being significant (P<0.05); The positive rates of Bcl-2 protein before and after irradiation were 73.3% and 46.7% respectively, with the difference being significant (P<0.05): The positive rates of bax protein before and after irradiation were 86% and 100 respectively, with the difference being significant (P<0.05). Conclusion: bax and Bcl-2 protein play an important role in apoptosis induced by fractionated radiation therapy. Apoptosis induced by irradiation is contributed to upregulation of bax protein or downregulation of Bcl-2 protein.

  4. Binding properties of oxacalix[4]arenes derivatives toward metal cations; Interactions entre cations metalliques et derives des oxacalix[4]arenes

    Energy Technology Data Exchange (ETDEWEB)

    Mellah, B

    2006-11-15

    The objective of this work was to establish the binding properties of oxacalix[4]arene derivatives with different numbers of the oxa bridges, functional groups (ketones, pyridine, ester, amide and methoxy) and conformations. Their interactions with alkali and alkaline-earth, heavy and transition metal cations have been evaluated according to different approaches: (i) extraction of corresponding picrates from an aqueous phase into dichloromethane; (ii) determination of the thermodynamic parameters of complexation in methanol and/or acetonitrile by UV-spectrophotometry and micro-calorimetry; (iii) determination of the stoichiometry of the complexes by ESI-MS; (iv) {sup 1}H-NMR titrations allowing to localize the metal ions in the ligand cavity. In a first part dealing on homo-oxacalix[4]arenes, selectivities for Na{sup +}, K{sup +}, Ca{sup 2+}, Pb{sup 2+} and Mn{sup 2+} of ketones derivatives was shown. The presence of oxa bridge in these derivatives increases their efficiency while decreasing their selectivity with respect to related calixarenes. The pyridine derivative prefers transition and heavy metal cations, in agreement with the presence of the soft nitrogen atoms. In the second part, di-oxacalix[4]arene ester and secondary amide derivatives were shown to be less effective than tertiary amide counterparts but to present high selectivities for Li{sup +}, Ba{sup 2+}, Zn{sup 2+} and Hg{sup 2+}. A third part devoted to the octa-homo-tetra-oxacalix[4]arene tetra-methoxy shows that the 1:1 metal complexes formed are generally more stable than those of calixarenes, suggesting the participation of the oxygen atoms of the bridge in the complexation. Selectivity for Cs{sup +}, Ba{sup 2+}, Cu{sup 2+} and Hg{sup 2+} were noted. (author)

  5. Photochemical generation of a primary vinyl cation from (E)-bromostyrene: Mechanisms of formation and reaction

    NARCIS (Netherlands)

    Gronheid, R.; Zuilhof, H.; Hellings, M.G.

    2003-01-01

    The photochemistry of (E)-bromostyrene was investigated to determine the nature of the product-forming intermediates and to clarify the mechanism of formation of vinylic cations and vinylic radicals. Both a cation- and a radical-derived product are formed, and the ionic origin of the former product

  6. Coordination Chemistry of Alkali and Alkaline-Earth Cations with Macrocyclic Ligands.

    Science.gov (United States)

    Dietrich, Bernard

    1985-01-01

    Discusses: (l) alkali and alkaline-earth cations in biology (considering naturally occurring lonophores, their X-ray structures, and physiochemical studies); (2) synthetic complexing agents for groups IA and IIA; and (3) ion transport across membranes (examining neutral macrobicyclic ligands as metal cation carriers, transport by anionic carriers,…

  7. Comparison of Cationic and Unmodified Starches in Reactive Extrusion of Starch-Polyacrylamide Graft Copolymers

    Science.gov (United States)

    Graft copolymers of starch and polyacrylamide (PAAm) were prepared using reactive extrusion in a corotating twin screw extruder. The effect of cationic starch modification was examined using unmodified and cationic dent starch (approximately 23% amylose) and waxy maize starch (approximately 2% amyl...

  8. Chemical mechanical polishing of transparent conductive layers using spherical cationic polymer microbeads

    Energy Technology Data Exchange (ETDEWEB)

    Nagaoka, Shoji, E-mail: nagaoka@kmt-iri.go.jp [Kumamoto Industrial Research Institute, 3-11-38 Higashimachi, Higashiku, Kumamoto 862-0901 (Japan); Department of Applied Chemistry and Biochemistry, Kumamoto University, 2-39-1 Kurokami, Chuouku, Kumamoto 860-8555 (Japan); Kumamoto Institute for Photo-Electro Organics (Phoenics), 3-11-38 Higashimachi, Higashiku, Kumamoto 862-0901 (Japan); Ryu, Naoya [Kumamoto Industrial Research Institute, 3-11-38 Higashimachi, Higashiku, Kumamoto 862-0901 (Japan); Yamanouchi, Akio [Department of Applied Chemistry and Biochemistry, Kumamoto University, 2-39-1 Kurokami, Chuouku, Kumamoto 860-8555 (Japan); Shirosaki, Tomohiro [Kumamoto Industrial Research Institute, 3-11-38 Higashimachi, Higashiku, Kumamoto 862-0901 (Japan); Kumamoto Institute for Photo-Electro Organics (Phoenics), 3-11-38 Higashimachi, Higashiku, Kumamoto 862-0901 (Japan); Horikawa, Maki [Kumamoto Industrial Research Institute, 3-11-38 Higashimachi, Higashiku, Kumamoto 862-0901 (Japan); Department of Applied Chemistry and Biochemistry, Kumamoto University, 2-39-1 Kurokami, Chuouku, Kumamoto 860-8555 (Japan); Kumamoto Institute for Photo-Electro Organics (Phoenics), 3-11-38 Higashimachi, Higashiku, Kumamoto 862-0901 (Japan); Sakurai, Hideo; Takafuji, Makoto; Ihara, Hirotaka [Department of Applied Chemistry and Biochemistry, Kumamoto University, 2-39-1 Kurokami, Chuouku, Kumamoto 860-8555 (Japan); Kumamoto Institute for Photo-Electro Organics (Phoenics), 3-11-38 Higashimachi, Higashiku, Kumamoto 862-0901 (Japan)

    2015-02-02

    Spherical cationic polymer microbeads were used to chemically mechanically polish transparent conductive oxide (TCO) layers without the need for inorganic abrasives. Poly(methyl acrylate) (PMA) was used as the polymer matrix. Surface cationization of the spherical PMA microbeads was achieved by aminolysis using 1,2-diaminoethane. The amino group content of the microbeads was controlled using the aminolysis reaction time. The surface roughness of the TCO polished using the cationic polymer microbeads was similar to that of TCO polished with an inorganic abrasive. The microbead-polished TCO layer was slightly thinner than the unpolished TCO layer. The sheet resistance of the TCO layer polished using the microbeads was lower than that polished using the inorganic abrasive. The TCO polishing ability of the microbeads was dependent on their cationic properties and softness. - Highlights: • Indium tin oxide (ITO) layer was planarized using cationic polymer microbeads. • Cationic polymer microbeads planarized, while retaining ITO layer thickness • Cationic polymer microbeads did not degrade the sheet resistance of ITO. • Cationic polymer microbeads could planarize the ITO surface without damaging.

  9. Biodistribution of rhodamine B fluorescence-labeled cationic nanoparticles in rats

    DEFF Research Database (Denmark)

    Knudsen, K. B.; Northeved, H.; Gjetting, Torben;

    2014-01-01

    were used. The animals were randomly allocated to five groups receiving either cationic micelles or cationic liposomes by single intravenous (IV) administration at a dose of 100 mg/kg bodyweight by single intracerebroventricular (ICV) injection at a dose of 50 μg or no treatment. ICV administration...

  10. Chemical Surface, Thermal and Electrical Characterization of Nafion Membranes Doped with IL-Cations

    Directory of Open Access Journals (Sweden)

    María del Valle Martínez de Yuso

    2014-04-01

    Full Text Available Surface and bulk changes in a Nafion membrane as a result of IL-cation doping (1-butyl-3-methylimidazolium tetrafluoroborate or BMIM+BF4 and phenyltrimethylammonium chloride or TMPA+Cl− were studied by X-ray photoelectron spectroscopy (XPS, contact angle, differential scanning calorimetry (DSC and impedance spectroscopy (IS measurements performed with dry samples after 24 h in contact with the IL-cations BMIM+ and TMPA+. IL-cations were selected due to their similar molecular weight and molar volume but different shape, which could facilitate/obstruct the cation incorporation in the Nafion membrane structure by proton/cation exchange mechanism. The surface coverage of the Nafion membrane by the IL-cations was confirmed by XPS analysis and contact angle, while the results obtained by the other two techniques (DSC and IS seem to indicate differences in thermal and electrical behaviour depending on the doping-cation, being less resistive the Nafion/BMIM+ membrane. For that reason, determination of the ion transport number was obtained for this membrane by measuring the membrane or concentration potential with the samples in contact with HCl solutions at different concentrations. The comparison of these results with those obtained for the original Nafion membrane provides information on the effect of IL-cation BMIM+ on the transport of H+ across wet Nafion/BMIM+ doped membranes.

  11. Novel Cholesterol-Based Cationic Lipids as Transfecting Agents of DNA for Efficient Gene Delivery

    Directory of Open Access Journals (Sweden)

    Jia Ju

    2015-03-01

    Full Text Available The design, synthesis and biological evaluation of the cationic lipid gene delivery vectors based on cholesterol and natural amino acids lysine or histidine are described. Cationic liposomes composed of the newly synthesized cationic lipids 1a or 1b and neutral lipid DOPE (1,2-dioleoyl-l-α-glycero-3-phosphatidyl-ethanolamine exhibited good transfection efficiency. pEGFP-N1 plasmid DNA was transferred into 293T cells by cationic liposomes formed from cationic lipids 1a and 1b, and the transfection activity of the cationic lipids was superior (1a or parallel (1b to that of the commercially available 3β-[N-(N',N'-dimethylaminoethyl-carbamoyl] cholesterol (DC-Chol derived from the same cholesterol backbone with different head groups. Combined with the results of agarose gel electrophoresis, transfection experiments with various molar ratios of the cationic lipids and DOPE and N/P (+/− molar charge ratios, a more effective formulation was formed, which could lead to relatively high transfection efficiency. Cationic lipid 1a represents a potential agent for the liposome used in gene delivery due to low cytotoxicity and impressive gene transfection activity.

  12. Cationic cell-penetrating peptides induce ceramide formation via acid sphingomyelinase: implications for uptake.

    NARCIS (Netherlands)

    Verdurmen, W.P.R.; Thanos, M.; Ruttekolk, I.R.R.; Gulbins, E.; Brock, R.E.

    2010-01-01

    Cationic cell-penetrating peptides (CPP) are receiving increasing attention as molecular transporters of membrane-impermeable molecules. Import of cationic CPP occurs both via endocytosis and - at higher peptide concentrations - in an endocytosis-independent manner via localized regions of the plasm

  13. SEQUESTRATION OF ORGANIC CATIONS BY ACIDIFIED HEPATIC ENDOCYTIC VESICLES AND IMPLICATIONS FOR BILIARY-EXCRETION

    NARCIS (Netherlands)

    VANDYKE, RW; FABER, ED; MEIJER, DKF

    1992-01-01

    A number of cationic amine drugs that are taken up by liver and excreted into bile may accumulate in acidified intracellular organelles such as lysosomes and endosomes. These studies were undertaken to assess directly the uptake and accumulation of three types of model organic cationic amines by end

  14. Base cation deposition in Europe - Part II. Acid neutralization capacity and contribution to forest nutrition

    NARCIS (Netherlands)

    Draaijers, G.P.J.; Leeuwen, E.P. van; Jong, P.G.H. de; Erisman, J.W.

    1997-01-01

    An assessment was made of the capacity of base cations to neutralize acid deposition and of the contribution of base cation deposition to forest nutrition in Europe. In large parts of southern Europe more than 50% of the potential acid deposition was found counteracted by deposition of non-sea salt

  15. Serum insensitive, intranuclear protein delivery by the multipurpose cationic lipid SAINT-2

    NARCIS (Netherlands)

    van der Gun, Bemardina T. F.; Monami, Amlie; Laarmann, Sven; Rasko, Tamas; Slaska-Kiss, Krystyna; Weinhold, Elmar; Wasserkort, Reinhold; de Leij, Lou F. M. H.; Ruiters, Marcel H. J.; Kiss, Antal; McLaughlin, Pamela M. J.

    2007-01-01

    Cationic liposomal compounds are widely used to introduce DNA and siRNA into viable cells, but none of these compounds are also capable of introducing proteins. Here we describe the use of a cationic amphiphilic lipid SAINT-2:DOPE for the efficient delivery of proteins into cells (profection). Label

  16. Chemical mechanical polishing of transparent conductive layers using spherical cationic polymer microbeads

    International Nuclear Information System (INIS)

    Spherical cationic polymer microbeads were used to chemically mechanically polish transparent conductive oxide (TCO) layers without the need for inorganic abrasives. Poly(methyl acrylate) (PMA) was used as the polymer matrix. Surface cationization of the spherical PMA microbeads was achieved by aminolysis using 1,2-diaminoethane. The amino group content of the microbeads was controlled using the aminolysis reaction time. The surface roughness of the TCO polished using the cationic polymer microbeads was similar to that of TCO polished with an inorganic abrasive. The microbead-polished TCO layer was slightly thinner than the unpolished TCO layer. The sheet resistance of the TCO layer polished using the microbeads was lower than that polished using the inorganic abrasive. The TCO polishing ability of the microbeads was dependent on their cationic properties and softness. - Highlights: • Indium tin oxide (ITO) layer was planarized using cationic polymer microbeads. • Cationic polymer microbeads planarized, while retaining ITO layer thickness • Cationic polymer microbeads did not degrade the sheet resistance of ITO. • Cationic polymer microbeads could planarize the ITO surface without damaging

  17. Avenanthramides Prevent Osteoblast and Osteocyte Apoptosis and Induce Osteoclast Apoptosis in Vitro in an Nrf2-Independent Manner

    Directory of Open Access Journals (Sweden)

    Gretel G. Pellegrini

    2016-07-01

    Full Text Available Oats contain unique bioactive compounds known as avenanthramides (AVAs with antioxidant properties. AVAs might enhance the endogenous antioxidant cellular response by activation of the transcription factor Nrf2. Accumulation of reactive oxygen species plays a critical role in many chronic and degenerative diseases, including osteoporosis. In this disease, there is an imbalance between bone formation by osteoblasts and bone resorption by osteoclasts, which is accompanied by increased osteoblast/osteocyte apoptosis and decreased osteoclast apoptosis. We investigated the ability of the synthethic AVAs 2c, 2f and 2p, to 1-regulate gene expression in bone cells, 2-affect the viability of osteoblasts, osteocytes and osteoclasts, and the generation of osteoclasts from their precursors, and 3-examine the potential involvement of the transcription factor Nrf2 in these actions. All doses of AVA 2c and 1 and 5 µM dose of 2p up-regulated collagen 1A expression. Lower doses of AVAs up-regulated OPG (osteoprotegerin in OB-6 osteoblastic cells, whereas 100 μM dose of 2f and all concentrations of 2c down-regulated RANKL gene expression in MLO-Y4 osteocytic cells. AVAs did not affect apoptosis of OB-6 osteoblastic cells or MLO-Y4 osteocytic cells; however, they prevented apoptosis induced by the DNA topoisomerase inhibitor etoposide, the glucocorticoid dexamethasone, and hydrogen peroxide. AVAs prevented apoptosis of both wild type (WT and Nrf2 Knockout (KO osteoblasts, demonstrating that AVAs-induced survival does not require Nrf2 expression. Further, KO osteoclast precursors produced more mature osteoclasts than WT; and KO cultures exhibited less apoptotic osteoclasts than WT cultures. Although AVAs did not affect WT osteoclasts, AVA 2p reversed the low apoptosis of KO osteoclasts. These in vitro results demonstrate that AVAs regulate, in part, the function of osteoblasts and osteocytes and prevent osteoblast/osteocyte apoptosis and increase osteoclast

  18. Avenanthramides Prevent Osteoblast and Osteocyte Apoptosis and Induce Osteoclast Apoptosis in Vitro in an Nrf2-Independent Manner.

    Science.gov (United States)

    Pellegrini, Gretel G; Morales, Cynthya C; Wallace, Taylor C; Plotkin, Lilian I; Bellido, Teresita

    2016-01-01

    Oats contain unique bioactive compounds known as avenanthramides (AVAs) with antioxidant properties. AVAs might enhance the endogenous antioxidant cellular response by activation of the transcription factor Nrf2. Accumulation of reactive oxygen species plays a critical role in many chronic and degenerative diseases, including osteoporosis. In this disease, there is an imbalance between bone formation by osteoblasts and bone resorption by osteoclasts, which is accompanied by increased osteoblast/osteocyte apoptosis and decreased osteoclast apoptosis. We investigated the ability of the synthethic AVAs 2c, 2f and 2p, to 1-regulate gene expression in bone cells, 2-affect the viability of osteoblasts, osteocytes and osteoclasts, and the generation of osteoclasts from their precursors, and 3-examine the potential involvement of the transcription factor Nrf2 in these actions. All doses of AVA 2c and 1 and 5 µM dose of 2p up-regulated collagen 1A expression. Lower doses of AVAs up-regulated OPG (osteoprotegerin) in OB-6 osteoblastic cells, whereas 100 μM dose of 2f and all concentrations of 2c down-regulated RANKL gene expression in MLO-Y4 osteocytic cells. AVAs did not affect apoptosis of OB-6 osteoblastic cells or MLO-Y4 osteocytic cells; however, they prevented apoptosis induced by the DNA topoisomerase inhibitor etoposide, the glucocorticoid dexamethasone, and hydrogen peroxide. AVAs prevented apoptosis of both wild type (WT) and Nrf2 Knockout (KO) osteoblasts, demonstrating that AVAs-induced survival does not require Nrf2 expression. Further, KO osteoclast precursors produced more mature osteoclasts than WT; and KO cultures exhibited less apoptotic osteoclasts than WT cultures. Although AVAs did not affect WT osteoclasts, AVA 2p reversed the low apoptosis of KO osteoclasts. These in vitro results demonstrate that AVAs regulate, in part, the function of osteoblasts and osteocytes and prevent osteoblast/osteocyte apoptosis and increase osteoclast apoptosis; further

  19. Increased expression of cytokines, soluble cytokine receptors, soluble apoptosis ligand and apoptosis in dengue.

    Science.gov (United States)

    Arias, Julia; Valero, Nereida; Mosquera, Jesús; Montiel, Milagros; Reyes, Eduardo; Larreal, Yraima; Alvarez-Mon, Melchor

    2014-03-01

    Several studies have been performed to determine biomarkers that define the risk factors to developing severe forms of dengue. In this study, the levels of TNF-α, IL-6, IL-1, IL-17, soluble interleukin-1 receptor like 1 protein (sST2), soluble TNF-related apoptosis-inducing ligand (sTRAIL), IL-12 and soluble receptors for TNF (sTNF-RI and sTNF-RII) were determined by ELISA in dengue patients and monocyte/macrophage cultures. Dengue was classified as dengue without warning symptoms (DNWS), with warning symptoms (DWWS) and severe dengue (SD). High values of IL-6, sTNFRI, sTNFRII and sST2 were observed in DWWS and/or SD and IL-12 and sTRAIL in DNWS. TNF-α and IL-17 were increased not associated to the disease severity. High production of TNF-α, IL-1β, IL-12, IL-17, sST2 and sTRAIL and apoptosis expression were observed in dengue monocyte/macrophage cultures. This study shows that beneficial or deleterious biomarkers can be present in dengue regardless the disease severity and that monocytes may be in part the source of studied molecules.

  20. Eutrophication of mangroves linked to depletion of foliar and soil base cations.

    Science.gov (United States)

    Fauzi, Anas; Skidmore, Andrew K; Heitkönig, Ignas M A; van Gils, Hein; Schlerf, Martin

    2014-12-01

    There is growing concern that increasing eutrophication causes degradation of coastal ecosystems. Studies in terrestrial ecosystems have shown that increasing the concentration of nitrogen in soils contributes to the acidification process, which leads to leaching of base cations. To test the effects of eutrophication on the availability of base cations in mangroves, we compared paired leaf and soil nutrient levels sampled in Nypa fruticans and Rhizophora spp. on a severely disturbed, i.e. nutrient loaded, site (Mahakam delta) with samples from an undisturbed, near-pristine site (Berau delta) in East Kalimantan, Indonesia. The findings indicate that under pristine conditions, the availability of base cations in mangrove soils is determined largely by salinity. Anthropogenic disturbances on the Mahakam site have resulted in eutrophication, which is related to lower levels of foliar and soil base cations. Path analysis suggests that increasing soil nitrogen reduces soil pH, which in turn reduces the levels of foliar and soil base cations in mangroves.