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Gong K, Du F, Xia Z, Durstock M, Dai L. Nitrogen-Doped Carbon Nanotube Arrays with High Electrocatalytic Activity for Oxygen Reduction. Science 2009; 323:760-4. [DOI: 10.1126/science.1168049] [Citation(s) in RCA: 5907] [Impact Index Per Article: 369.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Academic Contribution Register] [Indexed: 11/02/2022]
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Qu L, Dai L, Stone M, Xia Z, Wang ZL. Carbon Nanotube Arrays with Strong Shear Binding-On and Easy Normal Lifting-Off. Science 2008; 322:238-42. [DOI: 10.1126/science.1159503] [Citation(s) in RCA: 616] [Impact Index Per Article: 36.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Academic Contribution Register] [Indexed: 11/02/2022]
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Dai L, Vorselen D, Korolev KS, Gore J. Generic Indicators for Loss of Resilience Before a Tipping Point Leading to Population Collapse. Science 2012; 336:1175-7. [DOI: 10.1126/science.1219805] [Citation(s) in RCA: 448] [Impact Index Per Article: 34.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Academic Contribution Register] [Indexed: 11/02/2022]
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Wang Q, Yang H, Liu X, Dai L, Ma T, Qi J, Wong G, Peng R, Liu S, Li J, Li S, Song J, Liu J, He J, Yuan H, Xiong Y, Liao Y, Li J, Yang J, Tong Z, Griffin BD, Bi Y, Liang M, Xu X, Qin C, Cheng G, Zhang X, Wang P, Qiu X, Kobinger G, Shi Y, Yan J, Gao GF. Molecular determinants of human neutralizing antibodies isolated from a patient infected with Zika virus. Sci Transl Med 2016; 8:369ra179. [DOI: 10.1126/scitranslmed.aai8336] [Citation(s) in RCA: 163] [Impact Index Per Article: 18.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Academic Contribution Register] [Received: 08/18/2016] [Revised: 08/26/2016] [Accepted: 10/28/2016] [Indexed: 01/10/2023]
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Field JB, Toprakcioglu C, Ball RC, Stanley HB, Dai L, Barford W, Penfold J, Smith G, Hamilton W. Determination of end-adsorbed polymer density profiles by neutron reflectometry. Macromolecules 2002. [DOI: 10.1021/ma00027a067] [Citation(s) in RCA: 147] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Academic Contribution Register] [Indexed: 11/29/2022]
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Gao M, Huang S, Dai L, Wallace G, Gao R, Wang Z. Aligned Coaxial Nanowires of Carbon Nanotubes Sheathed with Conducting Polymers M.G. is grateful for a joint scholarship from Wollongong University and CSIRO; S.H. and L.D. thank the support from the Department of Industry, Science, and Technology (DIST), Australia; R.P.G. and Z.L.W. thank the support of US NSF grants (DMR-9733160), and the NSF of China. Angew Chem Int Ed Engl 2000; 39:3664-3667. [PMID: 11091432 DOI: 10.1002/1521-3773(20001016)39:20<3664::aid-anie3664>3.0.co;2-y] [Citation(s) in RCA: 112] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Academic Contribution Register] [Indexed: 11/07/2022]
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Kruit JK, Kremer PHC, Dai L, Tang R, Ruddle P, de Haan W, Brunham LR, Verchere CB, Hayden MR. Cholesterol efflux via ATP-binding cassette transporter A1 (ABCA1) and cholesterol uptake via the LDL receptor influences cholesterol-induced impairment of beta cell function in mice. Diabetologia 2010; 53:1110-9. [PMID: 20229095 DOI: 10.1007/s00125-010-1691-2] [Citation(s) in RCA: 95] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Academic Contribution Register] [Received: 01/09/2010] [Accepted: 01/13/2010] [Indexed: 10/19/2022]
Abstract
AIMS/HYPOTHESIS Cellular cholesterol accumulation is an emerging mechanism for beta cell dysfunction in type 2 diabetes. Absence of the cholesterol transporter ATP-binding cassette transporter A1 (ABCA1) results in increased islet cholesterol and impaired insulin secretion, indicating that impaired cholesterol efflux leads to beta cell dysfunction. In this study, we aimed to determine the role of the LDL receptor (LDLr) in islet cholesterol uptake and to assess the contributions of cholesterol uptake compared with efflux to islet cholesterol levels. METHODS Islet cholesterol and beta cell function were assessed in mice lacking LDLr (Ldlr(-/-)), or apolipoprotein E (Apoe(-/-)), as well as in mice with beta-cell-specific deficiency of Abca1 crossed to Ldlr(-/-) mice. RESULTS Hypercholesterolaemia resulted in increased islet cholesterol levels and decreased beta cell function in Apoe(-/-) mice but not in Ldlr(-/-) mice, suggesting that the LDL receptor is required for cholesterol uptake leading to cholesterol-induced beta cell dysfunction. Interestingly, when wild-type islets with functional LDL receptors were transplanted into diabetic, hypercholesterolaemic mice, islet graft function was normal compared with Ldlr(-/-) islets, suggesting that compensatory mechanisms can maintain islet cholesterol homeostasis in a hypercholesterolaemic environment. Indeed, transplanted wild-type islets had increased Abca1 expression. However, lack of the Ldlr did not protect Abca1(-/-) mice from islet cholesterol accumulation, suggesting that cholesterol efflux is the critical regulator of cholesterol levels in islets. CONCLUSIONS/INTERPRETATION Our data indicate that islet cholesterol levels and beta cell function are strongly influenced by LDLr-mediated uptake of cholesterol into beta cells. Cholesterol efflux mediated by ABCA1, however, can compensate in hypercholesterolaemia to regulate islet cholesterol levels in vivo.
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MESH Headings
- ATP Binding Cassette Transporter 1
- ATP-Binding Cassette Transporters/genetics
- ATP-Binding Cassette Transporters/metabolism
- Analysis of Variance
- Animals
- Blotting, Western
- Cell Line, Tumor
- Cells, Cultured
- Cholesterol/metabolism
- Diabetes Mellitus, Experimental/metabolism
- Diabetes Mellitus, Experimental/physiopathology
- Enzyme-Linked Immunosorbent Assay
- Hypercholesterolemia/metabolism
- Insulin/metabolism
- Insulin Secretion
- Insulin-Secreting Cells/metabolism
- Islets of Langerhans Transplantation
- Male
- Mice
- Mice, Knockout
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Receptors, LDL/genetics
- Receptors, LDL/metabolism
- Reverse Transcriptase Polymerase Chain Reaction
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Dai L, Yuan W, Ni B, Jia L. Os odontoideum: etiology, diagnosis, and management. SURGICAL NEUROLOGY 2000; 53:106-8; discussion 108-9. [PMID: 10713186 DOI: 10.1016/s0090-3019(99)00184-6] [Citation(s) in RCA: 90] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Academic Contribution Register] [Indexed: 11/18/2022]
Abstract
BACKGROUND There have been few reports of os odontoideum since the initial description. METHODS Forty-four patients with os odontoideum treated during the period 1980 through 1996 were reviewed. There were 33 males and 11 females. Their ages ranged from 7 to 56 years, with an average of 24.6 years. Five patients with no symptoms were treated conservatively. Thirty-nine patients underwent operative treatment including nine posterior atlantoaxial fusions and 33 occipitocervical fusions. RESULTS The patients were followed up for one to 16 years, with an average of 6.5 years. Five patients treated conservatively have remained stable. All 39 treated patients achieved solid arthrodesis. The results were satisfactory. CONCLUSIONS We conclude that fusion is indicated if atlantoaxial instability or clinical symptoms are significant, and that occipitocervical fusion should be considered in the operative management of os odontoideum if atlantoaxial arthrodesis is impossible.
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Dai L, Yasuda A, Naoki H, Corzo G, Andriantsiferana M, Nakajima T. IsCT, a novel cytotoxic linear peptide from scorpion Opisthacanthus madagascariensis. Biochem Biophys Res Commun 2001; 286:820-5. [PMID: 11520071 DOI: 10.1006/bbrc.2001.5472] [Citation(s) in RCA: 90] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Academic Contribution Register] [Indexed: 11/22/2022]
Abstract
A novel cytotoxic linear peptide, IsCT, was characterized from scorpion Opisthacanthus madagascariensis. It is a linear peptide with a molecular weight of 1501.9 Da composed of 13 amino acid residues without cysteines. MS/MS analysis showed that its C-terminal is amidated. The identity of IsCT is re-confirmed by comparing the chemical synthesized peptide with the natural one. IsCT demonstrated antimicrobial activity against both gram-positive and gram-negative bacteria and hemolytic activity to sheep red blood cells. Also, it can release histamine from rat peritoneal mast cells. The CD absorption suggested that IsCT had an alpha-helix configuration in aqueous TFE. IsCT is one of the shortest natural cytotoxic peptides described, and it will be a suitable model for studying peptide-lipid interactions.
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Dai L, Bellugi U, Chen XN, Pulst-Korenberg AM, Järvinen-Pasley A, Tirosh-Wagner T, Eis PS, Graham J, Mills D, Searcy Y, Korenberg JR. Is it Williams syndrome? GTF2IRD1 implicated in visual-spatial construction and GTF2I in sociability revealed by high resolution arrays. Am J Med Genet A 2009; 149A:302-14. [PMID: 19205026 DOI: 10.1002/ajmg.a.32652] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Academic Contribution Register] [Indexed: 01/06/2023]
Abstract
Genetic contributions to human cognition and behavior are clear but difficult to define. Williams syndrome (WS) provides a unique model for relating single genes to visual-spatial cognition and social behavior. We defined a approximately 1.5 Mb region of approximately 25 genes deleted in >98% of typical WS and then rare small deletions, showing that visual-spatial construction (VSC) in WS was associated with the genes GTF2IRD1 and GTF2I. To distinguish the roles of GTF2IRD1 and GTF2I in VSC and social behavior, we utilized multiple genomic methods (custom high resolution oligonucleotide microarray, multicolor FISH and somatic cell hybrids analyzed by PCR) to identify individuals deleted for either gene but not both. We analyzed genetic, cognitive and social behavior in a unique individual with WS features (heart defects, small size, facies), but with an atypical deletion of a set of genes that includes GTF2IRD1, but not GTF2I. The centromeric breakpoint localized to the region 72.32-72.38 Mb and the telomeric breakpoint to 72.66 Mb, 10 kb downstream of GTF2IRD1. Cognitive testing (WPPSI-R, K-BIT, and PLS-3) demonstrated striking deficits in VSC (Block Design, Object Assembly) but overall performance 1.5-3 SD above WS means. We have now integrated the genetic, clinical and cognitive data with previous reports of social behavior in this subject. These results combine with previous data from small deletions to suggest the gene GTF2IRD1 is associated with WS facies and VSC, and that GTF2I may contribute to WS social behaviors including increased gaze and attention to strangers.
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Research Support, Non-U.S. Gov't |
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Pessler F, Dai L, Diaz-Torne C, Gomez-Vaquero C, Paessler ME, Zheng DH, Einhorn E, Range U, Scanzello C, Schumacher HR. The synovitis of "non-inflammatory" orthopaedic arthropathies: a quantitative histological and immunohistochemical analysis. Ann Rheum Dis 2008; 67:1184-7. [PMID: 18203762 DOI: 10.1136/ard.2008.087775] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Academic Contribution Register] [Indexed: 11/04/2022]
Abstract
OBJECTIVE To quantify inflammatory changes in synovial membranes from orthopaedic "non-inflammatory" arthropathies (Orth. A). METHODS Synovial membranes from patients with femur fracture, avascular necrosis of the femur, plica syndrome, and meniscus and/or ligament injury (n = 23); rheumatoid arthritis (n = 28); osteoarthritis (OA; n = 25); and from normal controls (n = 10) were assessed by light microscopy, a histological synovitis score, immunostaining for CD3, CD20, CD38, CD68, Ki-67 and von Willebrand factor, and with an immunohistochemical inflammation score. RESULTS Orth. A histology varied between normal and markedly inflamed. Predominant abnormalities were mild lining hyperplasia, scattered inflammatory cells and small perivascular infiltrates. The synovitis score classified Orth. A as "mild synovitis". Inflammatory cells occurred frequently: CD68+ cells in 100% of Orth. A specimens; CD3+, 91%; CD38+, 70%; and CD20+, 39%. Orth. A had 36% greater lining thickness (p = 0.04), 40% higher vascular density (p = 0.009) and 51.3-fold higher CD38+ cell density (p = 0.02) than normal controls; and 60% fewer subintimal Ki-67+ cells (p = 0.003), 42% fewer CD68+ lining cells (p<0.01) and 40% fewer subintimal CD68+ cells (p<0.01) than OA. The immunohistochemical inflammation score was 2.2-fold higher in Orth. A than in controls (p = 0.048) and similar to OA, with three Orth. A specimens showing marked inflammation. CONCLUSIONS Synovial membranes from "non-inflammatory" arthropathies featured neovascularisation and inflammation intermediate between normal and OA synovium. These results expand previous findings that mechanical joint injury may lead to a mild-to-moderate synovitis.
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Research Support, N.I.H., Extramural |
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Dai L, Klibanov AM. Striking activation of oxidative enzymes suspended in nonaqueous media. Proc Natl Acad Sci U S A 1999; 96:9475-8. [PMID: 10449717 PMCID: PMC22233 DOI: 10.1073/pnas.96.17.9475] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Academic Contribution Register] [Accepted: 06/23/1999] [Indexed: 11/18/2022] Open
Abstract
The catalytic activity of four lyophilized oxidative enzymes-horseradish peroxidase, soybean peroxidase, Caldariomyces fumago chloroperoxidase, and mushroom polyphenol oxidase-is much lower when directly suspended in organic solvents containing little water than when they are introduced into the same largely nonaqueous media by first dissolving them in water and then diluting with anhydrous solvents. The lower the water content of the medium, the greater this discrepancy becomes. The mechanism of this phenomenon was found to arise from reversible denaturation of the oxidases on lyophilization: because of its conformational rigidity, the denatured enzyme exhibits very limited activity when directly suspended in largely nonaqueous media but renatures and thus yields much higher activity if first redissolved in water. Two independent means were discovered for dramatically minimizing the lyophilization-induced inactivation, both involving the addition of certain types of excipients to the aqueous enzyme solution before lyophilization. The first group of excipients consists of phenolic and aniline substrates as well as other hydrophobic compounds; these presumably bind to the hydrophobic pocket of the enzyme active site, thereby preventing its collapse during dehydration. The second group consists of general lyoprotectants such as polyols and polyethylen glycol that apparently preserve the overall enzyme structure during dehydration. The activation effects of such excipients can reach into the tens and hundreds of fold. Moreover, the activations afforded by the two excipient groups are additive, resulting in up to a complete protection against lyophilization-induced inactivation when representatives of the two are present together.
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research-article |
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Field JB, Toprakcioglu C, Dai L, Hadziioannou G, Smith G, Hamilton W. Neutron reflectivity study of end-adsorbed diblock copolymers : cross-over from nushrooms to brushes. ACTA ACUST UNITED AC 1992. [DOI: 10.1051/jp2:1992262] [Citation(s) in RCA: 75] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Academic Contribution Register] [Indexed: 11/14/2022]
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75 |
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Ryou H, Niu LN, Dai L, Pucci CR, Arola DD, Pashley DH, Tay FR. Effect of biomimetic remineralization on the dynamic nanomechanical properties of dentin hybrid layers. J Dent Res 2011; 90:1122-8. [PMID: 21730254 DOI: 10.1177/0022034511414059] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Academic Contribution Register] [Indexed: 11/17/2022] Open
Abstract
The mineral and organic phases of mineralized dentin contribute co-operatively to its strength and toughness. This study tested the null hypothesis that there is no difference in nano-dynamic mechanical behavior (complex modulus-E*; loss modulus-E''; storage modulus-E'; in GPa) of dentin hybrid layers (baseline: E*, 3.86 ± 0.24; E'', 0.23 ± 0.05; E', 3.85 ± 0.24) created by an etch-and-rinse adhesive in the presence or absence of biomimetic remineralization after in vitro aging. Using scanning probe microscopy and nano-dynamic mechanical analysis, we demonstrated that biomimetic remineralization restored the nano-dynamic mechanical behavior of heavily remineralized, resin-sparse regions of dentin hybrid layers (E*, 19.73 ± 3.85; E'', 8.75 ± 3.97; E', 16.02 ± 2.58) to those of the mineralized dentin base (E*, 19.20 ± 2.42; E'', 6.57 ± 1.96; E', 17.39 ± 2.0) [p > 0.05]. Conversely, those resin-sparse, water-rich regions degraded in the absence of biomimetic remineralization, with significant decline [p < 0.05] in their complex and storage moduli (E*, 0.83 ± 0.35; E'', 0.88 ± 0.24; E', 0.62 ± 0.32). Intrafibrillar apatite deposition preserves the integrity of resin-sparse regions of hybrid layers by restoring their nanomechanical properties to those exhibited by mineralized dentin.
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Research Support, U.S. Gov't, Non-P.H.S. |
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Tang H, Wang H, Fang Y, Zhu JY, Yin J, Shen YX, Zeng ZC, Jiang DX, Hou YY, Du M, Lian CH, Zhao Q, Jiang HJ, Gong L, Li ZG, Liu J, Xie DY, Li WF, Chen C, Zheng B, Chen KN, Dai L, Liao YD, Li K, Li HC, Zhao NQ, Tan LJ. Neoadjuvant chemoradiotherapy versus neoadjuvant chemotherapy followed by minimally invasive esophagectomy for locally advanced esophageal squamous cell carcinoma: a prospective multicenter randomized clinical trial. Ann Oncol 2023; 34:163-172. [PMID: 36400384 DOI: 10.1016/j.annonc.2022.10.508] [Citation(s) in RCA: 65] [Impact Index Per Article: 32.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Academic Contribution Register] [Received: 05/08/2022] [Revised: 09/29/2022] [Accepted: 10/13/2022] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND Neoadjuvant therapy is recommended for locally advanced esophageal cancer, but the optimal strategy remains unclear. We aimed to evaluate the safety and efficacy of neoadjuvant chemoradiotherapy (nCRT) versus neoadjuvant chemotherapy (nCT) followed by minimally invasive esophagectomy (MIE) for locally advanced esophageal squamous cell carcinoma (ESCC). PATIENTS AND METHODS Eligible patients staged as cT3-4aN0-1M0 ESCC were randomly assigned (1 : 1) to the nCRT or nCT group stratified by age, cN stage, and centers. The chemotherapy, based on paclitaxel and cisplatin, was administered to both groups, while concurrent radiotherapy was added for the nCRT group; then MIE was carried out. The primary endpoint was 3-year overall survival. This study is registered with ClinicalTrials.gov (NCT03001596). RESULTS A total of 264 patients were eligible for the intention-to-treat analysis. By 30 November 2021, 121 deaths had occurred. The median follow-up was 43.9 months (interquartile range 36.6-49.3 months). The overall survival in the intention-to-treat population was comparable between the nCRT and nCT strategies [hazard ratio (HR) 0.82, 95% confidence interval (CI) 0.58-1.18; P = 0.28], with a 3-year survival rate of 64.1% (95% CI 56.4% to 72.9%) versus 54.9% (95% CI 47.0% to 64.2%), respectively. There were also no differences in progression-free survival (HR 0.83, 95% CI 0.59-1.16; P = 0.27) and recurrence-free survival (HR 1.07, 95% CI 0.71-1.60; P = 0.75), although the pathological complete response in the nCRT group (31/112, 27.7%) was significantly higher than that in the nCT group (3/104, 2.9%; P < 0.001). Besides, a trend of lower risk of recurrence was observed in the nCRT group (P = 0.063), while the recurrence pattern was similar (P = 0.802). CONCLUSIONS NCRT followed by MIE was not associated with significantly better overall survival than nCT among patients with cT3-4aN0-1M0 ESCC. The results underscore the pending issue of the best strategy of neoadjuvant therapy for locally advanced bulky ESCC.
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Randomized Controlled Trial |
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Dai L, Ni B, Yuan W, Jia L. Radiculopathy after laminectomy for cervical compression myelopathy. THE JOURNAL OF BONE AND JOINT SURGERY. BRITISH VOLUME 1998; 80:846-9. [PMID: 9768896 DOI: 10.1302/0301-620x.80b5.8580] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Academic Contribution Register] [Indexed: 11/05/2022]
Abstract
Postoperative radiculopathy is a complication of posterior cervical decompression associated with tethering of the nerve root. We reviewed retrospectively 287 consecutive patients with cervical compression myelopathy who had been treated by multilevel cervical laminectomy and identified 37 (12.9%) with postoperative radiculopathy. There were 27 men and ten women with a mean age of 56 years at the time of operation. The diagnosis was either cervical spondylosis (25 patients) or ossification of the posterior longitudinal ligament (12 patients). Radiculopathy was observed from four hours to six days after surgery. The most frequent pattern of paralysis was involvement of the C5 and C6 roots of the motor-dominant type. The mean time for recovery was 5.4 months (two weeks to three years). The results at follow-up showed that the rate of motor recovery was negatively related to the duration of complete recovery of postoperative radiculopathy (gamma=-0.832, p < 0.01) and that patients with spondylotic myelopathy had a significantly better rate of clinical recovery than those with ossification of the posterior longitudinal ligament (t=2.960, p < 0.01). Postoperative radiculopathy may be prevented by carrying out an anterior decompression in conjunction with spinal fusion, which will achieve stabilisation and directly remove compression of the cord at multiple levels.
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Abstract
STUDY DESIGN An imaging study was designed to evaluate disc degeneration and segmental instability in the cervical spine. OBJECTIVES To compare the magnetic resonance imaging assessment of disc degeneration with the conventional plain radiographic evaluation of cervical segmental instability. SUMMARY OF BACKGROUND DATA No studies have been conducted to investigate the association of disc degeneration with cervical instability. METHODS Two hundred sixty consecutive patients with suspected cervical spine disorders were analyzed for horizontal and angular displacements on lateral flexion and extension radiographs and disc degeneration on T2-weighted magnetic resonance images of the cervical vertebrae. RESULTS In all intervertebral levels, the grade of disc degeneration increased significantly (P < 0.01) with age. Cervical instability was identified in 151 segments (14.5%) and correlated with Grade 1 and Grade 2 degeneration in the intervertebral discs (P < 0.01). CONCLUSIONS Cervical segmental instability may indicate early degeneration of intervertebral disc in the cervical vertebrae.
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Comparative Study |
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Jian JK, Chen XL, Tu QY, Xu YP, Dai L, Zhao M. Preparation and Optical Properties of Prism-Shaped GaN Nanorods. J Phys Chem B 2004. [DOI: 10.1021/jp048420o] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Academic Contribution Register] [Indexed: 11/29/2022]
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Abstract
STUDY DESIGN A retrospective study on 24 patients with acute central cervical cord injury caused by traumatic disc herniation. OBJECTIVES To determine the correlation of disc herniation with central cord injury and to evaluate the role of anterior cervical decompression and interbody fusion in management of this injury. SUMMARY OF BACKGROUND DATA Acute cervical disc herniation has been documented as a causative factor in spinal cord injury but has been infrequently reported with central cord syndrome. METHODS Between 1989 and 1994, 24 patients with acute cervical disc herniation and central cord syndrome were studied. These patients underwent anterior decompression and fusion, and were followed for 2 to 7 years, with an average follow-up period of 3 years and 8 months. The degree of disc herniation and neurologic scores were rated. RESULTS During follow-up period, the American Spinal Injury Association motor score in 24 patients was increased to 86.46 +/- 10.22 from 47.79 +/- 19.66. The age of the patients was very negatively correlated with recovery rate (P < 0.01), but no correlation was observed between severity of cord compression and neurologic scores (P > 0.05). Postoperative neurologic improvement in patients with fracture or dislocation was very significantly slower (P < 0.01) than in those without these injuries. CONCLUSIONS Far more common than previously expected, acute disc herniation in cervical spine injury is the one of principal cause for central cord syndrome. Magnetic resonance imaging assessment and surgical intervention are required.
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Gu L, Kim YK, Liu Y, Ryou H, Wimmer CE, Dai L, Arola DD, Looney SW, Pashley DH, Tay FR. Biomimetic analogs for collagen biomineralization. J Dent Res 2011; 90:82-7. [PMID: 20940362 PMCID: PMC3143382 DOI: 10.1177/0022034510385241] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Academic Contribution Register] [Received: 05/12/2010] [Revised: 06/26/2010] [Accepted: 06/28/2010] [Indexed: 11/17/2022] Open
Abstract
Inability of chemical phosphorylation of sodium trimetaphosphate to induce intrafibrillar mineralization of type I collagen may be due to the failure to incorporate a biomimetic analog to stabilize amorphous calcium phosphates (ACP) as nanoprecursors. This study investigated adsorption/desorption characteristics of hydrolyzed and pH-adjusted sodium trimetaphosphate (HPA-Na(3)P(3)O(9)) to collagen. Based on those results, a 5-minute treatment time with 2.8 wt% HPA-Na(3)P(3)O(9) was used in a single-layer reconstituted collagen model to confirm that both the ACP-stabilization analog and matrix phosphoprotein analog must be present for intrafibrillar mineralization. The results of that model were further validated by complete remineralization of phosphoric-acid-etched dentin treated with the matrix phosphoprotein analog and lined with a remineralizing lining composite, and with the ACP-stabilization analog supplied in simulated body fluid. An understanding of the basic processes involved in intrafibrillar mineralization of reconstituted collagen fibrils facilitates the design of novel tissue engineering materials for hard tissue repair and regeneration.
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Research Support, N.I.H., Extramural |
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Anagnostopoulou P, Dai L, Schatterny J, Hirtz S, Duerr J, Mall MA. Allergic airway inflammation induces a pro-secretory epithelial ion transport phenotype in mice. Eur Respir J 2010; 36:1436-47. [PMID: 20413543 DOI: 10.1183/09031936.00181209] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Academic Contribution Register] [Indexed: 11/05/2022]
Abstract
The airway epithelium is a central effector tissue in allergic inflammation and T-helper cell (Th) type 2-driven epithelial responses, such as mucus hypersecretion contribute to airflow obstruction in allergic airway disease. Previous in vitro studies demonstrated that Th2 cytokines also act as potent modulators of epithelial ion transport and fluid secretion, but the in vivo effect of allergic inflammation on airway ion transport remains unknown. We, therefore, induced allergic inflammation by intratracheal instillation of Aspergillus fumigatus extract or interleukin-13 in mice and determined effects on ion transport in native tracheal and bronchial tissues. We demonstrate that allergic inflammation enhanced basal Cl(-) secretion in both airway regions and inhibited epithelial Na(+) channel (ENaC)-mediated Na(+) absorption and increased Ca²(+)-dependent Cl(-) secretion in bronchi. Allergen-induced alterations in bronchial ion transport were associated with reduced transcript levels of α-, β- and γENaC, and were largely abrogated in signal transducer and activator of transcription (Stat)6(-/-) mice. Our studies demonstrate that Th2-dependent airway inflammation produced a pro-secretory ion transport phenotype in vivo, which was largely Stat6-dependent. These results suggest that Th2-mediated fluid secretion may improve airway surface hydration and clearance of mucus that is hypersecreted in allergic airway diseases such as asthma, and identify epithelial Stat6 signalling as a potential therapeutic target to promote mucus hydration and airway clearance.
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Research Support, Non-U.S. Gov't |
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Qin Z, Dai L, Bratoeva M, Slomiany MG, Toole BP, Parsons C. Cooperative roles for emmprin and LYVE-1 in the regulation of chemoresistance for primary effusion lymphoma. Leukemia 2011; 25:1598-609. [PMID: 21660043 DOI: 10.1038/leu.2011.144] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Academic Contribution Register] [Indexed: 12/13/2022]
Abstract
The Kaposi's sarcoma-associated herpesvirus is the causative agent of primary effusion lymphoma (PEL), for which cytotoxic chemotherapy represents the standard of care. The high mortality associated with PEL may be explained in part by resistance of these tumors to chemotherapy. The membrane-bound glycoprotein emmprin (CD147) enhances chemoresistance in tumors through effects on transporter expression, trafficking and interactions. Interactions between hyaluronan and hyaluronan receptors on the cell surface also facilitate emmprin-mediated chemoresistance. Whether emmprin or hyaluronan-receptor interactions regulate chemotherapeutic resistance for virus-associated malignancies is unknown. Using human PEL tumor cells, we found that PEL sensitivity to chemotherapy is directly proportional to expression of emmprin, the lymphatic vessel endothelial hyaluronan receptor-1 (LYVE-1) and a drug transporter known as the breast cancer resistance protein/ABCG2 (BCRP), and that emmprin, LYVE-1 and BCRP interact with each other and colocalize on the PEL cell surface. In addition, we found that emmprin induces chemoresistance in PEL cells through upregulation of BCRP expression, and RNA interference targeting of emmprin, LYVE-1 or BCRP enhances PEL cell apoptosis induced by chemotherapy. Finally, disruption of hyaluronan-receptor interactions using small hyaluronan oligosaccharides reduces expression of emmprin and BCRP while sensitizing PEL cells to chemotherapy. Collectively, these data support interdependent roles for emmprin, LYVE-1 and BCRP in chemotherapeutic resistance for PEL.
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Dai L, Li W, Hou X. Effect of the molecular structure of mixed nonionic surfactants on the temperature of miniemulsion formation. Colloids Surf A Physicochem Eng Asp 1997. [DOI: 10.1016/s0927-7757(96)03859-9] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Academic Contribution Register] [Indexed: 11/29/2022]
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Brookes PS, Zhang J, Dai L, Zhou F, Parks DA, Darley-Usmar VM, Anderson PG. Increased sensitivity of mitochondrial respiration to inhibition by nitric oxide in cardiac hypertrophy. J Mol Cell Cardiol 2001; 33:69-82. [PMID: 11133224 DOI: 10.1006/jmcc.2000.1276] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Academic Contribution Register] [Indexed: 11/22/2022]
Abstract
Cardiac hypertrophy is a significant risk factor for the development of congestive heart failure (CHF). Mitochondrial defects are reported in CHF, but no consistent mitochondrial alterations have yet been identified in hypertrophy. In this study selective metabolic inhibitors were used to determine thresholds for respiratory inhibition and to reveal novel mitochondrial defects in hypertrophy. Cardiac hypertrophy was produced in rats by aortic banding. Mitochondria were isolated from left ventricular tissue and the effects of inhibiting respiratory complexes I and IV on mitochondrial oxygen consumption were measured. At 8 weeks post-surgery, 65+/-2% complex IV inhibition was required to inhibit respiration half maximally in control mitochondria. In contrast, only 52+/-6% complex IV inhibition was required to inhibit respiration half maximally in mitochondria from hypertrophied hearts (P=0.046). This effect persisted at 22 weeks post-surgery and was accompanied by a significant upregulation of inducible nitric oxide synthase (iNOS, 3.0+/-0.7-fold, P=0.006). We conclude that respiration is more sensitive to complex IV inhibition in hypertrophy. Nitric oxide is a well documented inhibitor of complex IV, and thus the combination of increased NO(.)from iNOS and an increased sensitivity to inhibition of one of its targets could result in a bioenergetic defect in hypertrophy that may be a harbinger of CHF.
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