51
|
Packer L, Geng X, Bonazzi V, Mahon C, Ju R, Stephenson S, Pollock P. Combination of BGJ398 with either a pan-PI3K inhibitor or a specific PIK3CA inhibitor shows synergy in FGFR2 mutant endometrial cancer cell lines. Eur J Cancer 2016. [DOI: 10.1016/s0959-8049(16)61523-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
52
|
Geng X, Bo CX, Shao H. [Effects of malathion on testicular enzyme activities and sperm quality of male rats]. ZHONGHUA LAO DONG WEI SHENG ZHI YE BING ZA ZHI = ZHONGHUA LAODONG WEISHENG ZHIYEBING ZAZHI = CHINESE JOURNAL OF INDUSTRIAL HYGIENE AND OCCUPATIONAL DISEASES 2016; 34:329-32. [PMID: 27514410 DOI: 10.3760/cma.j.issn.1001-9391.2016.05.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
OBJECTIVE The aim of this study is to investigate the effects of sub chronic exposure to malathion on testicular enzyme activities and sperm quality of male rats. METHODS Forty male rats were divided into four groups: three exposure groups and a control group. Malathion was administered orally to male rats at 0, 33.75, 54.00, and 108.00 mg/kg for 60 days to evaluate the toxic alterations in sperm dynamics and testicular enzyme activities including ACP,LDH,SDH and γ-GT. The control rats were administered with an equivalent volume of distilled water in the same manner.After sacrificed, the testes were collected and weighed. RESULTS The body weight and the testis weight of animals showed a decreasing tendency, and there was a statistical difference between the 54.00, 108.00 mg/kg groups, and the control group (P<0.05). Malathion brought about marked reduction in testicular sperm counts, sperm motility, and significant growth of sperm malformation rate in 108.00 mg/kg group. A significant decrease in the activities of testicular enzyme ACP and γ-GT was observed in malathion exposed rats, while the activities of LDH was significant increased and there were no obvious effects on the activities of SDH. The activities of ACP, γ-GT and LDH showed a statistical difference between the 108.00 mg/kg groups, and the control group. CONCLUSION Malathion reduced the sperm counts and sperm motility, increased the malformation rate and reduced the activities of testicular enzymies of male rats.
Collapse
|
53
|
Geng X, Doitsh G, Yang Z, Galloway NLK, Greene WC. Erratum: Efficient delivery of lentiviral vectors into resting human CD4 T cells. Gene Ther 2016; 23:320-2. [DOI: 10.1038/gt.2015.115] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
54
|
Geng X, Qian Z. On an inversion theorem for Stratonovich’s signatures of multidimensional diffusion paths. ANNALES DE L'INSTITUT HENRI POINCARÉ, PROBABILITÉS ET STATISTIQUES 2016. [DOI: 10.1214/14-aihp644] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
|
55
|
Cai L, Stevenson J, Peng C, Xin R, Rastogi R, Liu K, Geng X, Gao Z, Ji X, Rafols JA, Ji Z, Ding Y. Adjuvant therapies using normobaric oxygen with hypothermia or ethanol for reducing hyperglycolysis in thromboembolic cerebral ischemia. Neuroscience 2016; 318:45-57. [PMID: 26794589 DOI: 10.1016/j.neuroscience.2016.01.010] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2015] [Revised: 11/25/2015] [Accepted: 01/06/2016] [Indexed: 01/08/2023]
Abstract
BACKGROUND AND PURPOSE Normobaric oxygen (NBO), ethanol (EtOH), and therapeutic hypothermia (TH) delivered alone or in combination have neuroprotective properties after acute stroke. We used an autologous thromboembolic rat stroke model to assess the additive effects of these treatments for reducing the deleterious effects of hyperglycolysis post-stroke in which reperfusion is induced with recombinant tissue plasminogen activator (rt-PA). METHODS Sprague-Dawley rats were subjected to middle cerebral artery (MCA) occlusion with an autologous embolus. One hour after occlusion, rt-PA was administered alone or with NBO (60%), EtOH (1.0 g/kg), TH (33 °C), either singly or in combination. Infarct volume and neurological deficit were assessed at 24h after rt-PA-induced reperfusion with or without other treatments. The extent of hyperglycolysis, as determined by cerebral glucose and lactate levels was evaluated at 3 and 24h after rt-PA administration. At the same time points, expressions of glucose transporter 1 (Glut1), glucose transporter 3 (Glut3), phosphofructokinase1 (PFK-1), and lactate dehydrogenase were (LDH) measured by Western blotting. RESULTS Following rt-PA in rats with thromboembolic stroke, NBO combined with TH or EtOH most effectively decreased infarct volume and neurological deficit. As compared to rt-PA alone, EtOH or TH but not NBO monotherapies significantly reduced post-stroke hyperglycolysis. The increased utilization of glucose and production of lactate post-stroke was prevented most effectively when NBO was combined with either EtOH or TH after reperfusion with rt-PA, as shown by the significantly decreased Glut1, Glut3, PFK-1, and LDH levels. CONCLUSIONS In a rat thromboembolic stroke model, both EtOH and TH used individually offer neuroprotection after the administration of rt-PA. While NBO monotherapy does not appear to be effective, it significantly potentiates the efficacy of EtOH and TH. The similar neuroprotection and underlying mechanisms pertaining to the attenuation of hyperglycolysis provided by EtOH or TH in combination with NBO suggest a possibility of substituting EtOH for TH. Thus a combination of NBO and EtOH, which are widely available and easily used, could become a novel and effective neuroprotective strategy in the clinical setting.
Collapse
|
56
|
Saverot S, Geng X, Leng W, Vikesland PJ, Grove TZ, Bickford LR. Facile, tunable, and SERS-enhanced HEPES gold nanostars. RSC Adv 2016. [DOI: 10.1039/c6ra00450d] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The facile, green synthesis of gold nanostars (AuNSs) with tunable branch lengths for SERS applications.
Collapse
|
57
|
Kola A, Geng X, Podlaha E. Ag–W electrodeposits with high W content from thiourea–citrate electrolytes. J Electroanal Chem (Lausanne) 2016. [DOI: 10.1016/j.jelechem.2015.12.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
58
|
Wang S, Deng Z, Ye X, Geng X, Zhang C. Enterococcus faecalis attenuates osteogenesis through activation of p38 and ERK1/2 pathways in MC3T3-E1 cells. Int Endod J 2015; 49:1152-1164. [PMID: 26572053 DOI: 10.1111/iej.12579] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2015] [Accepted: 11/06/2015] [Indexed: 01/18/2023]
Abstract
AIM To explore the role of Enterococcus faecalis in the proliferation, apoptosis and differentiation of osteoblasts. METHODOLOGY Pre-osteoblastic MC3T3-E1 cells were treated with heat-killed E. faecalis ATCC 29212 and clinical E. faecalis P25RC strains, respectively. Cell proliferation, mineralized calcium deposition, alkaline phosphatase (ALP) activity and apoptosis were assessed at various time-points. The expression levels of osteogenic-related genes including ALP, osteocalcin (OC), runt-related protein 2 (Runx2) and collagen type 1 (COL1) were also analysed throughout the duration of the experiment. Additionally, the involvement of mitogen-activated protein kinases (MAPKs) signalling pathways was analysed by Western blotting. In the presence of culture supernatant from E. faecalis-treated murine macrophages, apoptosis of MC3T3-E1 cells was detected with flow cytometry. Data were analysed using analysis of variance (anova), and P < 0.05 was considered significantly different. RESULTS E. faecalis significantly inhibited proliferation (P < 0.05) and also significantly induced apoptosis of MC3T3-E1 cells (P < 0.05), whilst differentiation seemed to be unaffected after 7 days of E. faecalis treatment. However, osteogenic differentiation was significantly inhibited with 21-day E. faecalis treatment (P < 0.05). The p38 and ERK1/2 phosphorylation pathways associated with mineral deposition and apoptosis were significantly activated in MC3T3-E1 cells. The culture supernatants from E. faecalis-treated macrophages induced osteoblast apoptosis. CONCLUSIONS E. faecalis exerted an inhibitory effect on osteogenesis in pre-osteoblastic MC3T3-E1 cells via phosphorylation of p38 and ERK1/2.
Collapse
|
59
|
Wang L, Cui S, Ma L, Kong L, Geng X. Current advances in the novel functions of hypoxia-inducible factor and prolyl hydroxylase in invertebrates. INSECT MOLECULAR BIOLOGY 2015; 24:634-648. [PMID: 26387499 DOI: 10.1111/imb.12189] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Oxygen is essential for aerobic life, and hypoxia has very severe consequences. Organisms need to overcome low oxygen levels to maintain biological functions during normal development and in disease states. The mechanism underlying the hypoxic response has been widely investigated in model animals such as Drosophila melanogaster and Caenorhabditis elegans. Hypoxia-inducible factor (HIF), a key gene product in the response to oxygen deprivation, is primarily regulated by prolyl hydroxylase domain enzymes (PHDs). However, recent findings have uncovered novel HIF-independent functions of PHDs. This review provides an overview of how invertebrates are able to sustain hypoxic damages, and highlights some recent discoveries in the regulation of cellular signalling by PHDs. Given that some core genes and major pathways are evolutionarily conserved, these research findings could provide insight into oxygen-sensitive signalling in mammals, and have biomedical implications for human diseases.
Collapse
|
60
|
|
61
|
Liu S, Li Y, Qin Z, Geng X, Bao L, Kaltenboeck L, Kucuktas H, Dunham R, Liu Z. High-density interspecific genetic linkage mapping provides insights into genomic incompatibility between channel catfish and blue catfish. Anim Genet 2015; 47:81-90. [PMID: 26537786 DOI: 10.1111/age.12372] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/30/2015] [Indexed: 02/01/2023]
Abstract
Catfish is the leading aquaculture species in the United States. The interspecific hybrid catfish produced by mating female channel catfish with male blue catfish outperform both of their parent species in a number of traits. However, mass production of the hybrids has been difficult because of reproductive isolation. Investigations of genome structure and organization of the hybrids provide insights into the genetic basis for maintenance of species divergence in the face of gene flow, thereby helping develop strategies for introgression and efficient production of the hybrids for aquaculture. In this study, we constructed a high-density genetic linkage map using the hybrid catfish system with the catfish 250K SNP array. A total of 26,238 SNPs were mapped to 29 linkage groups, with 12,776 unique marker positions. The linkage map spans approximately 3240 cM with an average intermarker distance of 0.25 cM. A fraction of markers (986 of 12,776) exhibited significant deviation from the expected Mendelian ratio of segregation, and they were clustered in major genomic blocks across 15 LGs, most notably LG9 and LG15. The distorted markers exhibited significant bias for maternal alleles among the backcross progenies, suggesting strong selection against the blue catfish alleles. The clustering of distorted markers within genomic blocks should lend insights into speciation as marked by incompatibilities between the two species. Such findings should also have profound implications for understanding the genomic evolution of closely related species as well as the introgression of hybrid production programs in aquaculture.
Collapse
|
62
|
Lin J, Geng X, Su W, Chan K, Lee E, Chang W, Honer W, Chen E. The Impacts of Yoga On Cortical Thickness, Neural Connectivity and Cognitive Function in Early Psychosis: Preliminary Results From a Randomized Controlled Clinical Trial. Eur Psychiatry 2015. [DOI: 10.1016/s0924-9338(15)30615-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
|
63
|
Liang J, Zhang B, Shen RW, Liu JB, Gao MH, Geng X, Li Y, Li YY, Zhang W. The effect of antifibrotic drug halofugine on Th17 cells in concanavalin A-induced liver fibrosis. Scand J Immunol 2014; 79:163-72. [PMID: 24383550 DOI: 10.1111/sji.12144] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2013] [Accepted: 11/25/2013] [Indexed: 12/14/2022]
Abstract
Anti-inflammation strategy is one of the proposed therapeutic approaches to hepatic fibrosis. T helper (Th) 17 cells, which play a detrimental role in experimental murine models of inflammatory diseases, have been demonstrated to participate in the pathogenesis of liver damage. The inhibitory effect of halofuginone (HF), an active component of extracts derived from the plant alkaloid febrifugine, on collagen synthesis has been shown in animal models of the fibrotic disease. The aim of this study was to clarify the in vivo effect of HF on Th17 cells in concanavalin A-induced fibrosis rats. Haematoxylin-eosin (HE) staining and Masson staining were performed to observe collagen deposition. The presence of INF-gamma, TNF-alpha, IL-6, IL-17, IL-1beta, IL-33 and IL-10 in serum and the presence of ROR-γt, IL-17, TGF-β1 and α-SMA in liver tissue were detected. Flow cytometry was performed to analyse the percentage of Th17 cells. We observed significantly lower levels of INF-gamma, TNF-alpha, IL-6, IL-17, IL-1beta, TGF-β1 and α-SMA in HF-treated group of rats, and the percentage of Th17 cells in splenic lymphocyte was decreased well. Histological examination demonstrated that HF significantly reduced the severity of liver fibrosis in HF-treated rats. We concluded that HF (10 mg/kg) exerts an antifibrotic impact on Th17 cells and its relative cytokines in rats with ConA-induced fibrosis.
Collapse
|
64
|
Geng X, Doitsh G, Yang Z, Galloway NLK, Greene WC. Efficient delivery of lentiviral vectors into resting human CD4 T cells. Gene Ther 2014; 21:444-9. [PMID: 24572792 DOI: 10.1038/gt.2014.5] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2013] [Revised: 12/18/2013] [Accepted: 01/03/2014] [Indexed: 02/07/2023]
Abstract
Resting human CD4 T cells are highly resistant to transfection or infection with lentiviral vectors derived from the human immunodeficiency virus. We now describe a flexible and efficient approach involving virus-like particles containing simian immunodeficiency virus lentiviral gene product protein X and pseudotyping with CXCR4-tropic HIV Env. This method permits effective genetic manipulation of these cells while preserving their naturally quiescent state. This technology can also be extended to primary lymphoid cultures where authentic cellular composition and functional relationships are preserved.
Collapse
|
65
|
Wang F, Chang GM, Geng X. Bioinformatics analysis of Exonic Splicing Enhancers (ESEs) for predicting potential regulatory elements of hTERT mRNA splicing. EUROPEAN REVIEW FOR MEDICAL AND PHARMACOLOGICAL SCIENCES 2014; 18:526-536. [PMID: 24610620] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
OBJECTIVES Alternative splicing of human telomerase reverse transcriptase (hTERT) has an important effect on regulating telomerase activity. Exonic splicing enhancers (ESEs) are a family of conserved splicing factors that participate in multiple steps of the splicing pathway. Our aim is to analyze the ESEs for predicting the potential regulatory elements of hTERT mRNA splicing. MATERIALS AND METHODS Enter the FASTA format of hTERT total sequences or individual exon as the input data in the main interface of ESEfinder3.0 and ESEfinder2.0 program. Analyze the data of output results and compare the differences between ESEfinder3.0 and ESEfinder2.0 program. RESULTS Five ESEs were predicted in exon 5 to exon 9 of hTERT. They were at position 108 located in hTERT exon 5, at position 92 located in exon 6, at position 22 located in exon 7, at position 73 located in exon 8 and at position 5 located in exon 9. There were no differences between ESEfinder 3.0 and ESEfinder 2.0 in our case. CONCLUSIONS The identification of these potential ESEs of hTERT might be helpful for the design of antisense oligonucleotides, which could modulate hTERT alternative splicing and inhibit telomerase activity.
Collapse
|
66
|
Geng X, Zhang R, Yang G, Jiang W, Xu C. Interleukin-2 and autoimmune disease occurrence and therapy. EUROPEAN REVIEW FOR MEDICAL AND PHARMACOLOGICAL SCIENCES 2012; 16:1462-1467. [PMID: 23111957] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
BACKGROUND Interleukin-2(IL-2), also called T-cell growth factor and primarily produced by antigen-activated T cells, is a kind of lymphoid factor with immunoregulatory effect which can promote T-cell-dependent immune responses. IL-2 was first used as a therapeutic approach to boost immune responses in patients with invasive cancer or advanced HIV disease. OBJECTIVES The purpose of the review is to refer the mechanism of autoimmune disease caused by IL-2 deletion and the application of IL-2 in curing autoimmune disease. STATE OF THE ART IL-2 signal plays a key role in promoting the development, homeostasis and the function of the regulatory T cells. The deletion of IL-2 in vivo causes T cell-mediated autoimmune diseases. Now it is being considered as a kind of medicine inhibiting immune responses. PERSPECTIVES Further studies with controlled clinical trials will be needed to prove the potential of IL-2 as a therapeutic strategy for autoimmune diseases. CONCLUSIONS The decreased production of IL-2 in patients with autoimmune disease leads to immune defects, such as decreased production of Treg cells, decreased AICD and cytotoxicity. Combination therapy based on IL-2 may prove to be beneficial in curing the immunological disorders.
Collapse
|
67
|
Cifarelli V, Geng X, Styche A, Lakomy R, Trucco M, Luppi P. C-peptide reduces high-glucose-induced apoptosis of endothelial cells and decreases NAD(P)H-oxidase reactive oxygen species generation in human aortic endothelial cells. Diabetologia 2011; 54:2702-12. [PMID: 21773684 DOI: 10.1007/s00125-011-2251-0] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/14/2011] [Accepted: 06/20/2011] [Indexed: 11/28/2022]
Abstract
AIMS/HYPOTHESIS Reactive oxygen species (ROS) generated during hyperglycaemia are implicated in the development of diabetic vascular complications. High glucose increases oxidative stress in endothelial cells and induces apoptosis. A major source of ROS in endothelial cells exposed to glucose is the NAD(P)H oxidase enzyme. Several studies demonstrated that C-peptide, the product of proinsulin cleavage within the pancreatic beta cells, displays anti-inflammatory effects in certain models of vascular dysfunction. However, the molecular mechanism underlying this effect is unclear. We hypothesised that C-peptide reduces glucose-induced ROS generation by decreasing NAD(P)H oxidase activation and prevents apoptosis METHODS Human aortic endothelial cells (HAEC) were exposed to 25 mmol/l glucose in the presence or absence of C-peptide and tested for protein quantity and activity of caspase-3 and other apoptosis markers by ELISA, TUNEL and immunoblotting. Intracellular ROS were measured by flow cytometry using the ROS sensitive dye chloromethyl-2',7'-dichlorodihydrofluorescein diacetate (CM-H(2)-DCDFA). NAD(P)H oxidase activation was assayed by lucigenin. Membrane and cytoplasmic levels of the NAD(P)H subunit ras-related C3 botulinum toxin substrate 1 (rho family, small GTP binding protein Rac1) (RAC-1) and its GTPase activity were studied by immunoblotting and ELISA. RAC-1 (also known as RAC1) gene expression was investigated by quantitative real-time PCR. RESULTS C-peptide significantly decreased caspase-3 levels and activity and upregulated production of the anti-apoptotic factor B cell CLL/lymphoma 2 (BCL-2). Glucose-induced ROS production was quenched by C-peptide and this was associated with a decreased NAD(P)H oxidase activity and reduced RAC-1 membrane production and GTPase activity. CONCLUSIONS/INTERPRETATION In glucose-exposed endothelial cells, C-peptide acts as an endogenous antioxidant molecule by reducing RAC-1 translocation to membrane and NAD(P)H oxidase activation. By preventing oxidative stress, C-peptide protects endothelial cells from glucose-induced apoptosis.
Collapse
|
68
|
Chengli X, Geng X, Jianping L, Qiutian L. Transport through the maxillary ostium in the ethmoid infundibulum. B-ENT 2011; 7:273-276. [PMID: 22338240] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023] Open
Abstract
OBJECTIVE The aim of this study was to use transnasal endoscopy to observe transport through the maxillary ostia in the ethmoid infundibulum, to gain more basic scientific information about the nasal cavity and paranasal sinus. METHODS Transnasal observation of 512 patients in a supine or seated position was conducted with 0- and 70-degree nasal endoscopes. Drainage pathways of mucopurulence at the natural maxillary ostia were observed. A dye test was also performed in 53 patients to clearly observe real-time transport of activated carbon in the ethmoid infundibulum. RESULTS Among 914 ethmoid infundibula, mucopurulence and activated carbon were transported out of 31 and 53 natural maxillary ostia, respectively. All ethmoid infundibula drained at the inferior edges of the ostium, despite patients' supine or seated positions. Fourteen cases of mucopurulence and 17 cases of activated carbon flowed circularly in the ethmoid infundibula. The flow of activated carbon from the natural ostium to the nasopharynx could also be observed simultaneously or solely. However, there were 6 ostia through which no activated carbon flowed back into or drained out of the sinus, despite flow from the natural ostium to the nasopharynx or circular flow. CONCLUSIONS The drainage pathway of the maxillary ostium is its inferior edge. The accessory ostium is only necessary to promote circular flow. Mucopurulence or activated carbon, which flowed circularly in the ethmoid infundibulum, can also be gradually transported to the nasopharynx. Revision surgery may not be necessary for all patients with circular chronic maxillary sinuses.
Collapse
|
69
|
Liu H, Shi L, Geng X, Su R, Cheng G, Xie S. Reactant-governing growth direction of indium nitride nanowires. NANOTECHNOLOGY 2010; 21:245601. [PMID: 20484787 DOI: 10.1088/0957-4484/21/24/245601] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Hexagonal wurtzite InN nanowires are grown via a vapor-liquid-solid (VLS) mechanism with an Au catalyst. Microstructure characterizations of a large number of nanowires demonstrate that the growth direction of InN nanowires is governed by variable NH(3) flux. InN nanowires at a NH(3) flux of 10 standard cubic centimeters per minute (sccm) grow preferentially in a hexagonal close-packed (hcp) <1010> direction, while those at 100 sccm NH(3) flux favor the hcp <0001> direction. A free energy minimization model is proposed to interpret this phenomenon. The first-principles calculations reveal that the <1010> oriented nucleus has the lowest energy at the lower NH(3) flux. In contrast, when NH(3) flux is high, the <0001> oriented nucleus has the lowest energy.
Collapse
|
70
|
Luppi P, Geng X, Cifarelli V, Drain P, Trucco M. C-peptide is internalised in human endothelial and vascular smooth muscle cells via early endosomes. Diabetologia 2009; 52:2218-28. [PMID: 19662378 DOI: 10.1007/s00125-009-1476-7] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/14/2009] [Accepted: 07/01/2009] [Indexed: 02/06/2023]
Abstract
AIMS/HYPOTHESIS There is increasing evidence that C-peptide exerts intracellular effects in a variety of cells and could be beneficial in patients with type 1 diabetes. Exactly how C-peptide achieves these effects, however, is unknown. Recent reports showed that C-peptide internalised in the cytoplasm of HEK-293 and Swiss 3T3 cells, where it was not degraded for at least 1 h after uptake. In this study, we investigated the hypothesis that C-peptide is internalised via an endocytic pathway and traffics to classic endocytic organelles, such as endosomes and lysosomes. METHODS We studied the internalisation of C-peptide in vascular endothelial and smooth muscle cells, two relevant targets of C-peptide activity, by using Alexa Fluor-labelled C-peptide probes in living cells and immunohistochemistry employing confocal laser-scanning microscopy. To examine trafficking to subcellular compartments, we used fluorescent constructs tagged to RAB5A, member RAS oncogene family (RAB5A) to identify early endosomes, or to lysosomal-associated membrane protein 1 (LAMP1) to identify lysosomes. RESULTS C-peptide internalised in the cytoplasm of cells within punctate structures identified as early endosomes. Internalisation was clearly detectable after 10 min of incubation and was blocked at 4 degrees C as well as with excess of unlabelled C-peptide. A minor fraction of vesicles, which increased with culture time, co-localised with lysosomes. Uptake of C-peptide was reduced by monodansylcadaverine, a pharmacological compound that blocks clathrin-mediated endocytosis, and by nocodazole, which disrupts microtubule assembly. CONCLUSIONS/INTERPRETATION C-peptide internalises in the cytoplasm of cells by endocytosis, as demonstrated by its localisation in early endosomes. Endosomes might represent a signalling station, through which C-peptide might achieve its cellular effects.
Collapse
|
71
|
Li YG, Geng X. A meta-analysis on the association of HER-2 overexpression with prognosis in human osteosarcoma. Eur J Cancer Care (Engl) 2009; 19:313-6. [PMID: 19709164 DOI: 10.1111/j.1365-2354.2008.00970.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Various studies examining the relationship between HER-2 overexpression and clinical outcome in patients with osteosarcoma have yielded inconclusive results. The purpose of the current study was to evaluate the relation of HER-2 status with clinical outcome in osteosarcoma. We conducted a meta-analysis of five studies that evaluated the relation between HER-2 status and 2-year survival. DerSimonian-Laird random effects analysis was used to estimate the effects of HER-2 overexpression on 2-year survival. The combined relative risk in patients with osteosarcoma for 2-year survival was 1.26 (95% confidence interval, 0.50-3.14; P = 0.63). HER-2-positive status tended to be associated with a worse 2-year survival, but the overall results were not formally statistically significant. An unfavourable prognostic effect of HER-2 overexpression in osteosarcoma was evident from the meta-analysis. However, because several studies were excluded by the current eligibility criteria, caution is needed in interpreting the results.
Collapse
|
72
|
Shin W, Geng X, Gu H, Yang Y. A New Brain Tissue Segmentation Algorithm Using Quantitative T1. Neuroimage 2009. [DOI: 10.1016/s1053-8119(09)71148-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
|
73
|
Geng X. Differential expression of human telomerase reverse transcriptase β-site remaining alternative splicing variants (hTERT β+ ASV) in gastric carcinogenesis. J Clin Oncol 2009. [DOI: 10.1200/jco.2009.27.15_suppl.e15641] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
e15641 Background: To investigate the changes of hTERT alternative splicing variants pattern in gastric cancer, precancerous lesions and normal gastric mucosa tissue. Methods: Three alternative splicing sites (α, β, γ) were selected and designed PCR primer. The expression of 8 hTERT alternative splicing variants (ASVs) in gastric cancer, precancerous lesions and normal gastric mucosa were detected by Semi-nested RT-PCR. The expression of β-site remaining ASV (β+ASV) in specimens of gastric cancer and specimens of precancerous lesions was detected by SYBER Green real-time PCR. Telomerase enzyme activity was evaluated associated with the different hTERT ASVs. Results: The positive rate of active full-length (α+β+γ+ ) ASV was significantly higher in gastric cancer than in precancerous lesions and normal mucosa (94.7% vs. 40.0% and 0, P<0.05). The positive rates of other ASVs were not different among the 3 groups(P>0.05). The positive rates of β+ ASVs (including α+β+γ+ASV, α-deletion ASV, γ-deletion ASV, αγ-deletion ASV) were 11.1% in normal mucosa,40.0% in precancerous lesions and 94.7% in gastric cancer (P<0.05). SYBR Green real-time RT-PCR showed that the expression level of β+ASV was 6.99 times higher in gastric cancer than in precancerous lesions. Further, increased telomerase enzyme activity was only associated with expression of the full-length hTERT isoform. Conclusions: hTERT alternative splicing pattern is different during gastric carcinogenesis. β+ASV was widely expressed in gastric carcinogenesis and may provide some information for diagnosis of gastric cancer or precancerous lesions. The gene expression patterns of hTERT alternative splicing variants may provide some useful information for diagnosis of gastric cancer and precancerous lesions. No significant financial relationships to disclose.
Collapse
|
74
|
Ebert EC, Panja A, Das KM, Praveen R, Geng X, Rezac C, Bajpai M. Patients with inflammatory bowel disease may have a transforming growth factor-beta-, interleukin (IL)-2- or IL-10-deficient state induced by intrinsic neutralizing antibodies. Clin Exp Immunol 2009; 155:65-71. [PMID: 19076830 DOI: 10.1111/j.1365-2249.2008.03802.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Ulcerative colitis (UC) and Crohn's disease (CD) are considered to be immunologically mediated disorders that share certain features with murine models of colitis. Whether any of these models are physiologically relevant to the human condition remains controversial. The hypothesis is that increased amounts of antibodies neutralizing transforming growth factor (TGF)-beta, interleukin (IL)-2 or IL-10 create a relative immunodeficient state in inflammatory bowel disease (IBD) that predisposes to disease. To evaluate this, serum samples from patients with UC or CD and from normal healthy individuals were studied by enzyme-linked immunosorbent assays. Antibodies recognizing TGF-beta were most prevalent in UC (P<0.01); anti-IL-10 antibodies were elevated in CD (P<0.05), while anti-IL-2 antibodies were the same for all three groups. Importantly, the percentage of IBD patients with at least one of the antibody levels greater than any control value was 30% for UC and 33% for CD. To verify the presence of these antibodies, immobilized TGF-beta was exposed to UC sera and the attached proteins identified by Western blot assay. The proteins proved to be exclusively immunoglobulin (Ig) G. To evaluate the neutralizing activity of these antibodies, cytokine-specific IgG from subjects in each group of patients was incubated with TGF-beta, IL-2 or IL-10 before addition to a bioassay with changes in viability determined by a colorimetric analysis. Antibodies from most individuals in all three groups neutralized the action of each cytokine. This study shows that about one-third of IBD patients may have a relative deficiency of TGF-beta, IL-2 or IL-10 due to an increase in neutralizing antibodies in their sera.
Collapse
|
75
|
Fu Y, Sun J, Ma J, Geng X, Sun J, Liu J, Song Y, Chen S. The neuroprotection of prodromal transient ischaemic attack on cerebral infarction. Eur J Neurol 2008; 15:797-801. [DOI: 10.1111/j.1468-1331.2008.02188.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|