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Le S, Moore JK, Haber JE, Greider CW. RAD50 and RAD51 define two pathways that collaborate to maintain telomeres in the absence of telomerase. Genetics 1999; 152:143-52. [PMID: 10224249 PMCID: PMC1460580 DOI: 10.1093/genetics/152.1.143] [Citation(s) in RCA: 301] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Telomere length is maintained by the de novo addition of telomere repeats by telomerase, yet recombination can elongate telomeres in the absence of telomerase. When the yeast telomerase RNA component, TLC1, is deleted, telomeres shorten and most cells die. However, gene conversion mediated by the RAD52 pathway allows telomere lengthening in rare survivor cells. To further investigate the role of recombination in telomere maintenance, we assayed telomere length and the ability to generate survivors in several isogenic DNA recombination mutants, including rad50, rad51, rad52, rad54, rad57, xrs2, and mre11. The rad51, rad52, rad54, and rad57 mutations increased the rate of cell death in the absence of TLC1. In contrast, although the rad50, xrs2, and mre11 strains initially had short telomeres, double mutants with tlc1 did not affect the rate of cell death, and survivors were generated at later times than tlc1 alone. While none of the double mutants of recombination genes and tlc1 (except rad52 tlc1) blocked the ability to generate survivors, a rad50 rad51 tlc1 triple mutant did not allow the generation of survivors. Thus RAD50 and RAD51 define two separate pathways that collaborate to allow cells to survive in the absence of telomerase.
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Abstract
Two new yeast genes, ASF1 (Anti-Silencing Function) and ASF2, as well as a C-terminal fragment of SIR3, were identified as genes that derepressed the silent mating type loci when overexpressed. ASF2 overexpression caused a greater derepression than did ASF1. ASF1 overexpression also weakened repression of genes near telomeres, but, interestingly, ASF2 had no effect on telomeric silencing. Sequences of these two genes revealed open reading frames of 279 and 525 amino acids for ASF1 and ASF2, respectively. The ASF1 protein was evolutionarily conserved, MCB motifs, sequences commonly present upstream of genes transcribed specifically in S phase, were found in front of both genes, and, indeed, both genes were transcribed specifically in the S phase of the cell cycle. While an asf2 mutant was viable and had no obvious phenotypes, an asf1 mutant grew poorly. Neither mutant exhibited derepression of the silent mating type loci. The asf1 mutant was sensitive to methyl methane sulfonate, slightly UV-sensitive and somewhat deficient in minichromosome maintenance. It also lowered the restrictive temperature of a cdc13ts mutant. These phenotypes suggested a role for ASF1 in DNA repair and chromosome maintenance.
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Kakkis E, McEntee M, Vogler C, Le S, Levy B, Belichenko P, Mobley W, Dickson P, Hanson S, Passage M. Intrathecal enzyme replacement therapy reduces lysosomal storage in the brain and meninges of the canine model of MPS I. Mol Genet Metab 2004; 83:163-74. [PMID: 15464431 DOI: 10.1016/j.ymgme.2004.07.003] [Citation(s) in RCA: 135] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/31/2004] [Revised: 07/05/2004] [Accepted: 07/07/2004] [Indexed: 11/19/2022]
Abstract
Enzyme replacement therapy (ERT) has been developed for several lysosomal storage disorders, including mucopolysaccharidosis I (MPS I), and is effective at reducing lysosomal storage in many tissues and in ameliorating clinical disease. However, intravenous ERT does not adequately treat storage disease in the central nervous system (CNS), presumably due to effects of the blood-brain barrier on enzyme distribution. To circumvent this barrier, we studied whether intrathecal (IT) recombinant human alpha-L-iduronidase (rhIDU) could penetrate and treat the brain and meninges. An initial dose-response study showed that doses of 0.46-4.14 mg of IT rhIDU successfully penetrated the brain of normal dogs and reached tissue levels 5.6 to 18.9-fold normal overall and 2.7 to 5.9-fold normal in deep brain sections lacking CSF contact. To assess the efficacy and safety in treating lysosomal storage disease, four weekly doses of approximately 1 mg of IT rhIDU were administered to MPS I-affected dogs resulting in a mean 23- and 300-fold normal levels of iduronidase in total brain and meninges, respectively. Quantitative glycosaminoglycan (GAG) analysis showed that the IT treatment reduced mean total brain GAG to normal levels and achieved a 57% reduction in meningeal GAG levels accompanied by histologic improvement in lysosomal storage in all cell types. The dogs did develop a dose-dependent immune response against the recombinant human protein and a meningeal lymphocytic/plasmacytic infiltrate. The IT route of ERT administration may be an effective way to treat the CNS disease in MPS I and could be applicable to other lysosomal storage disorders.
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Le S, Sternglanz R, Greider CW. Identification of two RNA-binding proteins associated with human telomerase RNA. Mol Biol Cell 2000; 11:999-1010. [PMID: 10712515 PMCID: PMC14826 DOI: 10.1091/mbc.11.3.999] [Citation(s) in RCA: 105] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Telomerase plays a crucial role in telomere maintenance in vivo. To understand telomerase regulation, we have been characterizing components of the enzyme. To date several components of the mammalian telomerase holoenzyme have been identified: the essential RNA component (human telomerase RNA [hTR]), the catalytic subunit human telomerase reverse transcriptase (hTERT), and telomerase-associated protein 1. Here we describe the identification of two new proteins that interact with hTR: hStau and L22. Antisera against both proteins immunoprecipitated hTR, hTERT, and telomerase activity from cell extracts, suggesting that the proteins are associated with telomerase. Both proteins localized to the nucleolus and cytoplasm. Although these proteins are associated with telomerase, we found no evidence of their association with each other or with telomerase-associated protein 1. Both hStau and L22 are more abundant than TERT. This, together with their localization, suggests that they may be associated with other ribonucleoprotein complexes in cells. We propose that these two hTR-associated proteins may play a role in hTR processing, telomerase assembly, or localization in vivo.
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Le S, Connors TJ, Maroney AC. c-Jun N-terminal kinase specifically phosphorylates p66ShcA at serine 36 in response to ultraviolet irradiation. J Biol Chem 2001; 276:48332-6. [PMID: 11602589 DOI: 10.1074/jbc.m106612200] [Citation(s) in RCA: 84] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Mice lacking expression of the p66 isoform of the ShcA adaptor protein (p66(ShcA)) are less susceptible to oxidative stress and have an extended life span. Specifically, phosphorylation of p66(ShcA) at serine 36 is critical for the cell death response elicited by oxidative damage. We sought to identify the kinase(s) responsible for this phosphorylation. Utilizing the SH-SY5Y human neuroblastoma cell model, it is demonstrated that p66(ShcA) is phosphorylated on serine/threonine residues in response to UV irradiation. Both c-Jun N-terminal kinases (JNKs) and p38 mitogen-activated protein kinases are activated by UV irradiation, and we show that both are capable of phosphorylating serine 36 of p66(ShcA) in vitro. However, treatment of cells with a multiple lineage kinase inhibitor, CEP-1347, that blocks UV-induced JNK activation, but not p38, phosphatidylinositol 3-kinase, or MEK1 inhibitors, prevented p66(ShcA) phosphorylation in SH-SY5Y cells. Consistent with this finding, transfected activated JNK1, but not the kinase-dead JNK1, leads to phosphorylation of serine 36 of p66(ShcA) in Chinese hamster ovary cells. In conclusion, JNKs are the kinases that phosphorylate serine 36 of p66(ShcA) in response to UV irradiation in SH-SY5Y cells, and blocking p66(ShcA) phosphorylation by intervening in the JNK pathway may prevent cellular damage due to light-induced oxidative stress.
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Lockyer S, Okuyama K, Begum S, Le S, Sun B, Watanabe T, Matsumoto Y, Yoshitake M, Kambayashi J, Tandon NN. GPVI-deficient mice lack collagen responses and are protected against experimentally induced pulmonary thromboembolism. Thromb Res 2006; 118:371-80. [PMID: 16139873 DOI: 10.1016/j.thromres.2005.08.001] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2005] [Revised: 07/14/2005] [Accepted: 08/02/2005] [Indexed: 11/24/2022]
Abstract
Platelet glycoprotein VI (GPVI) is now considered to be a major player in platelet-collagen adhesive interactions leading to thrombus formation. GPVI blockade, or its depletion, has been shown in mice to result in complete protection against arterial thrombosis, without significant prolongation of bleeding time. GPVI may therefore represent a useful antithrombotic target. In order to reaffirm the role of GPVI in platelet-collagen interactions, we developed GPVI(null) mice by targeted disruption methodology. GPVI(null) mice platelets failed to respond to a high dose of fibrillar collagen, or convulxin, a GPVI agonist, but showed a normal response to other agonists such as ADP, PMA and arachidonic acid. We report, for the first time, that a proportion of GPVI(null) mice is protected against lethal thromboembolism, induced by the infusion of a mixture of collagen and epinephrine. Greater than 55% of GPVI(null) mice survived the challenge, whereas the maximal survival from the other genotypes was 17% (n=18 per genotype). Washed platelets obtained from GPVI(null) mice showed >90% reduction in adhesion to fibrillar collagen under static conditions. Platelet adhesion to collagen under dynamic conditions using a high shear rate (2600 s(-1)) was dramatically reduced using blood from GPVI(null) mice, while platelets from wild-type and heterozygous animals showed a similar amount of adhesion. Animals from each genotype had essentially similar tail bleeding time, suggesting that a complete deficiency of GPVI, at least in mice, does not result in an enhanced bleeding tendency. These observations clearly establish that blockade of GPVI may attenuate platelet-collagen interactions without adversely affecting the bleeding time.
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Halliday GM, Le S. Transforming growth factor-beta produced by progressor tumors inhibits, while IL-10 produced by regressor tumors enhances, Langerhans cell migration from skin. Int Immunol 2001; 13:1147-54. [PMID: 11526095 DOI: 10.1093/intimm/13.9.1147] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The induction of epidermal immunity depends on activation of local dendritic cells (DC), Langerhans cells (LC), to migrate from the skin to local lymph nodes and mature into potent immunostimulatory cells. We have previously shown that progressor skin tumors, which evade immunological destruction, prevent contact sensitizer-induced LC migration from the skin to draining lymph nodes. In contrast, regressor tumors, which evoke protective immunity, did not inhibit DC mobilization. In this study we utilized the skin explant model to determine the factors produced by skin tumors which regulate LC migration from the skin. Supernatants from two progressor squamous cell carcinoma lines both inhibited LC migration, whereas supernatants from two regressor squamous cell carcinoma lines both enhanced LC mobilization. Transforming growth factor (TGF)-beta1 inhibited, while IL-10 enhanced, LC migration from cultured skin. Both reduced the ability of LC to mature into potent allostimulators. Antibody neutralization identified that TGF-beta1 produced by the progressor tumor was responsible for inhibition of LC migration, while IL-10 produced by the regressor tumor enhanced LC mobilization. Thus these studies show that skin tumors influence DC mobilization from tumors by production of cytokines, and that TGF-beta1 is one factor produced by tumors which can immobilize LC and keep them in an immature form. This is likely to be an important mechanism of tumor escape from the immune system as progressor tumors inhibited, while regressor tumors enhanced DC mobilization.
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Le S, Zhu JJ, Anthony DC, Greider CW, Black PM. Telomerase activity in human gliomas. Neurosurgery 1998; 42:1120-4; discussion 1124-5. [PMID: 9588558 DOI: 10.1097/00006123-199805000-00099] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
OBJECTIVE Telomerase activity, which is undetectable in most mature normal tissues, has been identified in many types of human cancers, including neuroblastomas and oligodendrogliomas. These findings suggest that a novel mechanism in addition to activation of oncogenes and inactivation of tumor suppressor genes may play an important role in tumorigenesis. The goal of the present study was to assess and correlate the telomerase activity in astrocytic gliomas of different grades. METHODS Telomere repeat amplification protocol and Southern blot hybridization with telomere-specific probes were used to detect telomerase activity and to measure terminal restriction fragment length, respectively. RESULTS Telomerase activity was detected in 3 of 9 (33%) low-grade astrocytomas (World Health Organization Grade II), 5 of 11 (45%) anaplastic astrocytomas (World Health Organization Grade III), 36 of 41 (89%) glioblastomas multiforme (World Health Organization Grade IV), 3 of 4 (75%) oligodendrogliomas, and none of 4 normal brain specimens. CONCLUSION We demonstrated that telomerase activity is absent in normal brain tissues while present in most glioma samples (72%). The frequency of such activity increases with malignancy. These results suggest that telomerase activity may be used as a tumor marker and that the activation of telomerase may correlate with initiation and malignant progression of astrocytic tumors.
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Woodruff M, Ramonell R, Cashman K, Nguyen D, Saini A, Haddad N, Ley A, Kyu S, Howell JC, Ozturk T, Lee S, Chen W, Estrada J, Morrison-Porter A, Derrico A, Anam F, Sharma M, Wu H, Le S, Jenks S, Tipton CM, Hu W, Lee FEH, Sanz I. Dominant extrafollicular B cell responses in severe COVID-19 disease correlate with robust viral-specific antibody production but poor clinical outcomes. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2020. [PMID: 32511635 DOI: 10.1101/2020.04.29.20083717] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
A wide clinical spectrum has become a hallmark of the SARS-CoV-2 (COVID-19) pandemic, although its immunologic underpinnings remain to be defined. We have performed deep characterization of B cell responses through high-dimensional flow cytometry to reveal substantial heterogeneity in both effector and immature populations. More notably, critically ill patients displayed hallmarks of extrafollicular B cell activation as previously described in autoimmune settings. Extrafollicular activation correlated strongly with large antibody secreting cell expansion and early production of high levels of SARS-CoV-2-specific antibodies. Yet, these patients fared poorly with elevated inflammatory biomarkers, multi-organ failure, and death. Combined, the findings strongly indicate a major pathogenic role for immune activation in subsets of COVID-19 patients. Our study suggests that, as in autoimmunity, targeted immunomodulatory therapy may be beneficial in specific patient subpopulations that can be identified by careful immune profiling.
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Preprint |
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Wong SF, Ward C, Lee-Tannock A, Le S, Chan FY. Pulmonary artery/aorta ratio in simple screening for fetal outflow tract abnormalities during the second trimester. ULTRASOUND IN OBSTETRICS & GYNECOLOGY : THE OFFICIAL JOURNAL OF THE INTERNATIONAL SOCIETY OF ULTRASOUND IN OBSTETRICS AND GYNECOLOGY 2007; 30:275-80. [PMID: 17721863 DOI: 10.1002/uog.4105] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
OBJECTIVES Congenital heart disease is associated with high mortality and morbidity rates, being the most life-threatening defect in the first month of postnatal life and accounting for approximately half of all childhood mortality from birth defects. Despite this, the prenatal detection rate for congenital outflow tract anomalies by ultrasound imaging is relatively low. The aim of this study was to establish a nomogram for the pulmonary artery/aorta (PA/AO) ratio measured in the three-vessel view plane. This ratio was investigated as a simple screening tool for congenital cardiac outflow tract abnormalities. METHODS The study was a prospective evaluation of 966 singleton fetuses at 16-24 weeks of gestation and 46 fetuses with congenital cardiac outflow tract abnormalities. The diameters of the pulmonary artery and aorta were measured in the three-vessel view. The PA/AO ratio was calculated and a nomogram was constructed. The mean and 95% CI for the ratio were defined and the PA/AO ratios of cases with outflow tract abnormalities were plotted against the values for normal fetuses. RESULTS The gestational age of the normal group ranged from 16 to 24 weeks, with a median of 19 weeks. The pulmonary artery diameter measured between 2.1 and 4.93 mm (mean, 3.3 mm) and the aorta measured between 2.1 and 5.2 mm (mean, 2.93 mm). The mean (SD) PA/AO ratio was 1.16 (0.18) (95% CI, 0.87-1.58; range 0.61-1.86; median, 1.14). For fetuses with outflow tract abnormalities, the median gestation was 19 weeks and 37/43 (86%) had a PA/AO ratio outside the 95% CI. CONCLUSIONS The PA/AO ratio derived from measurements in the three-vessel view plane can be used as an initial screening tool for outflow tract anomalies and may have a sensitivity of up to 86%, with a 5% false-positive rate.
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Evaluation Study |
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Moule CA, Angelis F, Kim GH, Le S, Malipatil S, Foo MS, Burrow MF, Thomas D. Resin bonding using an all-etch or self-etch adhesive to enamel after carbamide peroxide and/or CPP-ACP treatment. Aust Dent J 2007; 52:133-7. [PMID: 17687960 DOI: 10.1111/j.1834-7819.2007.tb00478.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND Limited evidence exists regarding the effect of carbamide peroxide and casein phosphopeptide amorphous calcium phosphate (CPP-ACP) on composite-enamel bonding. Microshear bond strengths, using either a total-etch or self-etching adhesive, to enamel treated with carbamide peroxide and/or CPP-ACP were investigated. MATERIALS AND METHODS Twenty-six extracted human third molars were sectioned into four parts, each being allocated into one of the four groups (n=26): bleach (Polanight, 16% carbamide peroxide), CPP-ACP (GC Tooth Mousse), bleach and then CPP-ACP, or untreated (control). The surfaces were bonded with a total-etch bonding system (Single Bond) or a self-etching primer system (Clearfil SE Bond) and tested using a microshear test. RESULTS A significant difference in bond strength was found between bonding systems. SE Bond showed the highest bond strength to untreated enamel (p < 0.05). The microshear bond strength of SE Bond decreased when the enamel was treated with carbamide peroxide, CPP-ACP or both (p < 0.05). Only combined use of carbamide peroxide and CPP-ACP significantly affected microshear bond strength with Single Bond. CONCLUSION These findings suggest the shear bond strength of resin to enamel using a self-etching priming adhesive may be affected if the enamel is treated with a bleaching agent or CPP-ACP.
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Journal Article |
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Haddad NS, Nguyen DC, Kuruvilla ME, Morrison-Porter A, Anam F, Cashman KS, Ramonell RP, Kyu S, Saini AS, Cabrera-Mora M, Derrico A, Alter D, Roback JD, Horwath M, O'Keefe JB, Wu HM, Wong AKI, Dretler AW, Gripaldo R, Lane AN, Wu H, Chu HY, Lee S, Hernandez M, Engineer V, Varghese J, Patel R, Jalal A, French V, Guysenov I, Lane CE, Mengistsu T, Normile KE, Mnzava O, Le S, Sanz I, Daiss JL, Lee FEH. One-Stop Serum Assay Identifies COVID-19 Disease Severity and Vaccination Responses. Immunohorizons 2021; 5:322-335. [PMID: 34001652 PMCID: PMC9190970 DOI: 10.4049/immunohorizons.2100011] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Accepted: 02/26/2021] [Indexed: 01/13/2023] Open
Abstract
SARS-CoV-2 has caused over 100,000,000 cases and almost 2,500,000 deaths globally. Comprehensive assessment of the multifaceted antiviral Ab response is critical for diagnosis, differentiation of severity, and characterization of long-term immunity, especially as COVID-19 vaccines become available. Severe disease is associated with early, massive plasmablast responses. We developed a multiplex immunoassay from serum/plasma of acutely infected and convalescent COVID-19 patients and prepandemic and postpandemic healthy adults. We measured IgA, IgG, and/or IgM against SARS-CoV-2 nucleocapsid (N), spike domain 1 (S1), S1-receptor binding domain (RBD) and S1-N-terminal domain. For diagnosis, the combined [IgA + IgG + IgM] or IgG levels measured for N, S1, and S1-RBD yielded area under the curve values ≥0.90. Virus-specific Ig levels were higher in patients with severe/critical compared with mild/moderate infections. A strong prozone effect was observed in sera from severe/critical patients-a possible source of underestimated Ab concentrations in previous studies. Mild/moderate patients displayed a slower rise and lower peak in anti-N and anti-S1 IgG levels compared with severe/critical patients, but anti-RBD IgG and neutralization responses reached similar levels at 2-4 mo after symptom onset. Measurement of the Ab responses in sera from 18 COVID-19-vaccinated patients revealed specific responses for the S1-RBD Ag and none against the N protein. This highly sensitive, SARS-CoV-2-specific, multiplex immunoassay measures the magnitude, complexity, and kinetics of the Ab response and can distinguish serum Ab responses from natural SARS-CoV-2 infections (mild or severe) and mRNA COVID-19 vaccines.
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Matsumoto Y, Takizawa H, Gong X, Le S, Lockyer S, Okuyama K, Tanaka M, Yoshitake M, Tandon NN, Kambayashi J. Highly potent anti-human GPVI monoclonal antibodies derived from GPVI knockout mouse immunization. Thromb Res 2007; 119:319-29. [PMID: 16566959 DOI: 10.1016/j.thromres.2006.01.023] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2005] [Revised: 01/17/2006] [Accepted: 01/27/2006] [Indexed: 10/24/2022]
Abstract
Recent progress in the understanding of thrombus formation has suggested an important role for glycoprotein (GP) VI in this process. To clarify the exact role in detail, it is necessary to use specific, high affinity inhibitory antibodies. However, possibly due to the conserved structure of GPVI among species, it has been difficult to obtain potent antibodies. In this study, we developed highly potent anti-human GPVI monoclonal antibodies using GPVI knockout mice for immunization. Fab fragments of these antibodies, named OM1 and OM2, potently inhibit collagen-induced platelet aggregation. The IC(50) values for OM1 and OM2 are 0.6+/-0.05 and 1.7+/-0.5 microg/mL, respectively, showing potency greater than, or equal to that of abciximab (1.7+/-0.3 microg/mL), an anti-GPIIb/IIIa antibody. Fab fragments of OM1 and OM2 also potently inhibit collagen-induced ATP release, thromboxane A(2) formation, and platelet adhesion to immobilized collagen under static and flow conditions. Interestingly, platelet aggregation induced with collagen-related peptide was potently inhibited by OM2 but not OM1, indicating that OM1 recognizes an epitope that is different from collagen-related peptide-binding site on GPVI. These results suggest that OM1 and OM2 may be useful tools to understand the role of GPVI in thrombus formation. Furthermore, these antibodies have the potential to be developed as a new class of therapeutic tool.
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Leung MK, Le S, Houston S, Stefano GB. Degradation of Met-enkephalin by hemolymph peptidases in Mytilus edulis. Cell Mol Neurobiol 1992; 12:367-78. [PMID: 1334805 PMCID: PMC11567185 DOI: 10.1007/bf00711539] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/1992] [Accepted: 03/20/1992] [Indexed: 12/26/2022]
Abstract
1. Met-enkephalin is degraded by peptidases present in the hemolymph fluid and hemocyte membrane suspension of Mytilus edulis. Degradation of Met-enkephalin is rapid in the fluid and slower in the membrane. 2. Aminopeptidase activity is bestatin sensitive in hemocyte membrane and highest in the fluid of the hemolymph, which appears to have a component which is insensitive to inhibitor. 3. ACE activity is found only in the fluid of the hemolymph. 4. Carboxypeptidase and NEP (CD10: "enkephalinase") are membrane bound and the former appears to predominate. Phosphoramidon inhibits not only NEP, as expected, but the invertebrate carboxypeptidase as well.
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Park GY, Le S, Park KH, Le CT, Kim YW, Han SK, Shim YS, Yoo CG. Anti-inflammatory effect of adenovirus-mediated IkappaBalpha overexpression in respiratory epithelial cells. Eur Respir J 2001; 18:801-9. [PMID: 11757631 DOI: 10.1183/09031936.01.00099801] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Many studies into basic biological characteristics of inflammation and tissue injury have implicated pro-inflammatory cytokine-mediated tissue injury in the pathogenesis of inflammatory lung diseases. Because transcription of most proinflammatory cytokines is dependent on the activation of nuclear factor (NF)-kappaB, NF-kappaB could be a good potential target to suppress the cytokine cascade. Cytokine-induced activation of NF-kappaB requires phosphorylation and subsequent degradation of IkappaBa. Therefore, the blocking NF-kappaB activation by IkappaBalpha could inhibit the pro-inflammatory cytokine-induced tissue injury. To evaluate whether blocking of NF-kappaB activation shows an anti-inflammatory effect, this study investigated the effect of adenovirus-mediated overexpression of IkappaBalpha super-repressor (IkappaBalpha-SR) on the pro-inflammatory cytokine expression in respiratory epithelial cells. The transduction efficiency of adenovirus was >90% in both A549 and NCI-H157 cells. Ad5IkappaBalpha-SR-transduced cells expressed high levels of IkappaBalpha-SR, which was resistant to tumour necrosis factor (TNF)-alpha-induced degradation. Adenovirus-mediated overexpression of IkappaBalpha-SR blocked cytokine-induced nuclear translocation of p65 and NF-kappaB deoxyribonucleic acid binding activity without affecting total cellular expression level of NF-kappaB. Ad5IkappaBalpha-SR transduction suppressed cytokine-induced interleukin-8 and TNF-alpha expressions at both ribonucleic acid and protein levels. These results suggest that blocking the nuclear factor-kappaB pathway by adenovirus-mediated overexpression of IkappaBalpha-super-repressor shows an effective anti-inflammatory effect in respiratory epithelial cells.
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King A, Guignot N, Zerbino P, Boulard E, Desjardins K, Bordessoule M, Leclerq N, Le S, Renaud G, Cerato M, Bornert M, Lenoir N, Delzon S, Perrillat JP, Legodec Y, Itié JP. Tomography and imaging at the PSICHE beam line of the SOLEIL synchrotron. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2016; 87:093704. [PMID: 27782575 DOI: 10.1063/1.4961365] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
PSICHE (Pressure, Structure and Imaging by Contrast at High Energy) is the high-energy beam line of the SOLEIL synchrotron. The beam line is designed to study samples at extreme pressures, using diffraction, and to perform imaging and tomography for materials science and other diverse applications. This paper presents the tomograph and the use of the beam line for imaging, with emphasis on developments made with respect to existing instruments. Of particular note are the high load capacity rotation stage with free central aperture for installing large or complex samples and sample environments, x-ray mirror and filter optics for pink beam imaging, and multiple options for combining imaging and diffraction measurement. We describe how x-ray imaging techniques have been integrated into high-pressure experiments. The design and the specifications of the beam line are described, and several case studies drawn from the first user experiments are presented.
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Wingerter S, Gupta S, Le S, Shamasunder S, Bernstein R, Rabitaille W, Kukuyeva Y, Downie S. Unusual origin of the flexor digiti minimi brevis muscle. Clin Anat 2003; 16:531-3. [PMID: 14566903 DOI: 10.1002/ca.10122] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
An unusual origin of the flexor digiti minimi brevis muscle of the right hand was discovered during cadaveric dissection. The muscle originated from the anterior aspect of the transverse fibers of the distal antebrachial fascia and inserted onto the base of the fifth proximal phalanx. When traction was applied to the proximal portion of the muscle, flexion was produced at the fifth metacarpophalangeal joint. Other intrinsic muscles of the hand and the muscles of the flexor forearm compartment had normal morphology. Although muscular anomalies in the hypothenar region have been described, the muscular variant described here was distinct in its origin and size from those previously reported. Knowledge of anomalous muscles in the hand has important clinical significance in routine surgery and in determining associated pathology.
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Le S, Chuong CJ, Parkening TA. Effect of ovariectomy and estrogen replacement on hypothalamic, pituitary and peripheral blood beta-endorphin levels in the rat. Neuropeptides 1991; 20:175-80. [PMID: 1762667 DOI: 10.1016/0143-4179(91)90128-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
This study was initiated to detect possible changes in beta-endorphin (beta-EP) levels of the hypothalamus, anterior pituitary gland, and peripheral blood of rats after ovariectomy and estrogen administration. Attempts were also made to determine the correlation between peripheral and central levels of beta-EP. Twenty-six Sprague-Dawley rats were decapitated. Nine had intact ovaries (Gr. INT), and 17 were ovariectomized 3 weeks before they were killed. Nine of the ovariectomized rats received estradiol benzoate (EB) (Gr. EB) and the other 8 received peanut oil (Gr. OVX) prior to the decapitation. A beta-EP radioimmunoassay was used to analyze homogenates of the hypothalamus and anterior pituitary, and peripheral blood. In the hypothalamus, beta-EP levels were significantly lower in Gr. INT and Gr. EB than in Gr. OVX. In the pituitary gland and peripheral blood, beta-EP levels were significantly higher in Gr. INT than in Gr. OVX. Pituitary beta-EP levels did not vary between Gr. OVX and Gr. EB, although beta-EP levels in peripheral blood were significantly higher in Gr. EB than in Gr. OVX. No significant correlations were noted in beta-EP levels between the hypothalamus, pituitary gland, and peripheral blood in either Gr. INT, Gr. OVX, or Gr. EB. It appears that EB exerts different effects on beta-EP levels in the hypothalamus, anterior pituitary gland, and peripheral blood, and that beta-EP levels in these regions may be independent of one another.
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Haddad NS, Nozick S, Kim G, Ohanian S, Kraft C, Rebolledo PA, Wang Y, Wu H, Bressler A, Le SNT, Kuruvilla M, Cannon LE, Lee FEH, Daiss JL. Novel immunoassay for diagnosis of ongoing Clostridioides difficile infections using serum and medium enriched for newly synthesized antibodies (MENSA). J Immunol Methods 2021; 492:112932. [PMID: 33221459 DOI: 10.1016/j.jim.2020.112932] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Revised: 11/12/2020] [Accepted: 11/16/2020] [Indexed: 01/13/2023]
Abstract
BACKGROUND Clostridioides difficile infections (CDI) have been a challenging and increasingly serious concern in recent years. While early and accurate diagnosis is crucial, available assays have frustrating limitations. OBJECTIVE Develop a simple, blood-based immunoassay to accurately diagnose patients suffering from active CDI. MATERIALS AND METHODS Uninfected controls (N = 95) and CDI patients (N = 167) were recruited from Atlanta area hospitals. Blood samples were collected from patients within twelve days of a positive CDI test and processed to yield serum and PBMCs cultured to yield medium enriched for newly synthesized antibodies (MENSA). Multiplex immunoassays measured Ig responses to ten recombinant C. difficile antigens. RESULTS Sixty-six percent of CDI patients produced measurable responses to C. difficile antigens in their serum or MENSA within twelve days of a positive CDI test. Fifty-two of the 167 CDI patients (31%) were detectable in both serum and MENSA, but 32/167 (19%) were detectable only in MENSA, and 27/167 (16%) were detectable only in serum. DISCUSSION We describe the results of a multiplex immunoassay for the diagnosis of ongoing CDI in hospitalized patients. Our assay resolved patients into four categories: MENSA-positive only, serum-positive only, MENSA- and serum-positive, and MENSA- and serum-negative. The 30% of patients who were MENSA-positive only may be accounted for by nascent antibody secretion prior to seroconversion. Conversely, the serum-positive only subset may have been more advanced in their disease course. Immunocompromise and misdiagnosis may have contributed to the 34% of CDI patients who were not identified using MENSA or serum immunoassays. IMPORTANCE While there was considerable overlap between patients identified through MENSA and serum, each method detected a distinctive patient group. The combined use of both MENSA and serum to detect CDI patients resulted in the greatest identification of CDI patients. Together, longitudinal analysis of MENSA and serum will provide a more accurate evaluation of successful host humoral immune responses in CDI patients.
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Ruqiao L, Yueli C, Xuelan Z, Huifen L, Xin Z, Danjie Z, Le S, Yanxue Z. Rhizoma Atractylodis macrocephalae: a review of photochemistry, pharmacokinetics and pharmacology. DIE PHARMAZIE 2021; 75:42-55. [PMID: 32213234 DOI: 10.1691/ph.2020.9738] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 09/29/2022]
Abstract
Rhizoma Atractylodis macrocephalae is commonly used in Traditional Chinese Medicine. Its traditional functions include treating hypofunction of the spleen with the loss of appetite, abdominal distension diarrhea, phlegm drink dizziness palpitation, edema, fetal movement restless. A literature search was conducted by systematic searching multiple electronic databases including Web of Science, PubMed, CNKI and Google Scholar. Chemical composition analysis of RAM showed that the main compositions were volatile oil, lactones, polysaccharides, amino acids, vitamins and resins. Pharmacological studies indicated that RAM possessed antitumor activities, neuroprotective effect, anti-hepatotoxicity, immune and anti-inflammatory activity, etc. This review gives a detailed description of the chemical constituents, pharmacology and pharmacokinetics of RAM and provides reliable basis for clinical development and application.
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Haddad NS, Nguyen DC, Kuruvilla ME, Morrison-Porter A, Anam F, Cashman KS, Ramonell RP, Kyu S, Saini AS, Cabrera-Mora M, Derrico A, Alter D, Roback JD, Horwath M, O'Keefe JB, Wu HM, Ian Wong AK, Dretler AW, Gripaldo R, Lane AN, Wu H, Lee S, Hernandez M, Engineer V, Varghese J, Le S, Sanz I, Daiss JL, Eun-Hyung Lee F. Elevated SARS-CoV-2 Antibodies Distinguish Severe Disease in Early COVID-19 Infection. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2020. [PMID: 33299998 DOI: 10.1101/2020.12.04.410589] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Background SARS-CoV-2 has caused over 36,000,000 cases and 1,000,000 deaths globally. Comprehensive assessment of the multifaceted anti-viral antibody response is critical for diagnosis, differentiation of severe disease, and characterization of long-term immunity. Initial observations suggest that severe disease is associated with higher antibody levels and greater B cell/plasmablast responses. A multi-antigen immunoassay to define the complex serological landscape and clinical associations is essential. Methods We developed a multiplex immunoassay and evaluated serum/plasma from adults with RT-PCR-confirmed SARS-CoV-2 infections during acute illness (N=52) and convalescence (N=69); and pre-pandemic (N=106) and post-pandemic (N=137) healthy adults. We measured IgA, IgG, and/or IgM against SARS-CoV-2 Nucleocapsid (N), Spike domain 1 (S1), receptor binding domain (S1-RBD) and S1-N-terminal domain (S1-NTD). Results To diagnose infection, the combined [IgA+IgG+IgM] or IgG for N, S1, and S1-RBD yielded AUC values -0.90 by ROC curves. From days 6-30 post-symptom onset, the levels of antigen-specific IgG, IgA or [IgA+IgG+IgM] were higher in patients with severe/critical compared to mild/moderate infections. Consistent with excessive concentrations of antibodies, a strong prozone effect was observed in sera from severe/critical patients. Notably, mild/moderate patients displayed a slower rise and lower peak in anti-N and anti-S1 IgG levels compared to severe/critical patients, but anti-RBD IgG and neutralization responses reached similar levels at 2-4 months. Conclusion This SARS-CoV-2 multiplex immunoassay measures the magnitude, complexity and kinetics of the antibody response against multiple viral antigens. The IgG and combined-isotype SARS-CoV-2 multiplex assay is highly diagnostic of acute and convalescent disease and may prognosticate severity early in illness. One Sentence Summary In contrast to patients with moderate infections, those with severe COVID-19 develop prominent, early antibody responses to S1 and N proteins.
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Rivera-Calonje F, Chen SYE, Lo C, Le S, Nagoshi M. Urgent surgery for COVID-19-positive pediatric patient. JA Clin Rep 2021; 7:57. [PMID: 34292420 PMCID: PMC8297428 DOI: 10.1186/s40981-021-00461-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2021] [Revised: 07/11/2021] [Accepted: 07/12/2021] [Indexed: 12/03/2022] Open
Abstract
Background We present a case of COVID-19–positive pediatric patient for urgent urological surgery by spinal anesthesia to avoid aerosolizing procedure. Case presentation A 12-year-old, COVID-19–positive boy presented for urgent wound incision and drainage at the circumcision site. Our anesthetic plan consisted of spinal anesthesia with sedation. He was transported from the COVID-19 isolation floor to the negative pressure operating room. He was placed in lateral decubitus position and oxygen was delivered through facemask. Under sedation, spinal anesthesia was achieved at first attempt. The patient maintained spontaneous ventilation without airway intervention. Patient was recovered in the operation room then transported back to the floor. Conclusion Spinal anesthesia is a safe alternative to general endotracheal anesthesia for many pediatric urology procedures. Effective team communication and preparation are keys when caring COVID-19–positive patient in perioperative setting to avoid minimize the risk to healthcare providers.
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Le S, Zhang Y, Voutilainen A, Tan X, Laukkanen J, Wang C, Cheng S. Differences in cardiometabolic risk profiles between Chinese and Finnish older adults with glucose impairment and central obesity. J Endocrinol Invest 2022; 45:1427-1437. [PMID: 35325446 PMCID: PMC9184414 DOI: 10.1007/s40618-022-01777-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Accepted: 02/23/2022] [Indexed: 12/06/2022]
Abstract
BACKGROUND Obesity and ethnicity play important roles in cardiovascular complications in patients with type 2 diabetes mellitus (T2DM). This study aimed to compare cardiometabolic risk profiles between Chinese and Finnish older adults of central obesity with prediabetes or T2DM. METHODS Study subjects were 60-74 years old and originated from two population samples. The Finnish subjects came from the Kuopio Ischemic Heart Disease (KIHD) study (n = 1089), and the Chinese subjects came from the Shanghai High-risk Diabetic Screen (SHiDS) study (n = 818). The KIHD and SHiDS studies used similar questionnaires to determine participants' baseline characteristics regarding the history of medication use and diseases and lifestyle factors. All study subjects participated in glucose tolerance tests and anthropometry assessments, including waist circumference measurements. RESULTS Among study subjects of central obesity with prediabetes (n = 298), fasting and 2-h glucose, and fasting insulin and insulin resistance were significantly higher in Chinese than in Finnish (p < 0.0001-0.016). In addition, triglyceride (TG) level was higher and the low-density lipoprotein cholesterol (LDL) and LDL to high-density lipoprotein cholesterol (HDL) ratio were lower in Chinese than in Finnish (p < 0.0001-0.003). Among subjects of central obesity with T2DM (n = 251), Chinese subjects had significantly less proportions of antihypertensive, glycaemic control medication, and statin users as well as lower level of physical activity (p < 0.0001 for all), while higher blood pressure (p = 0.002 for systolic blood pressure and p < 0.0001 for diastolic blood pressure), TG levels (p < 0.05) and HDL (p = 0.002) than the Finnish counterparts. There were no differences in β-cell function (HOMA-β) between Chinese and Finnish both in prediabetes and T2DM. CONCLUSIONS Our results indicated that Chinese and Finnish older adults of central obesity with prediabetes and T2DM had similar β-cell function. However, Chinese individuals with prediabetes are prone to insulin resistance. Meanwhile, lipid metabolism dysfunction is also different between Chinese and Finnish. Chinese older adults of central obesity with prediabetes showed higher TG, but Finnish showed higher LDL and LDL/HDL. Strategic for T2DM prevention and treatment should be ethnically specific.
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Lo C, Ross PA, Le S, Kim E, Keefer M, Rosales A. Engaging Parents in Analgesia Selection and Racial/Ethnic Differences in Analgesia Given to Pediatric Patients Undergoing Urologic Surgery. CHILDREN-BASEL 2020; 7:children7120277. [PMID: 33297304 PMCID: PMC7762314 DOI: 10.3390/children7120277] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Revised: 12/02/2020] [Accepted: 12/04/2020] [Indexed: 01/07/2023]
Abstract
BACKGROUND Family-centered care aims to consider family preferences and values in care delivery. Our study examines parent decisions regarding anesthesia type (caudal regional block or local anesthesia) among a diverse sample of children undergoing urologic surgeries. Differences in anesthesia type were examined by known predictors of health disparities, including child race/ethnicity, parental English proficiency, and a proxy for household income. METHODS A retrospective review of 4739 patients (including 25.4% non-Latino/a White, 8.7% non- Latino/a Asians, 7.3% non-Latino/a Black, 23.1% Latino/a, and 35.4% others) undergoing urologic surgeries from 2016 to 2020 using univariate and logistic regression analyses. RESULTS 62.1% of Latino/a parents and 60.8% of non-Latino/a Black parents did not agree to a regional block. 65.1% of Spanish-speaking parents with limited English Proficiency did not agree to a regional block. Of parents from households below poverty lines, 61.7% did not agree to a caudal regional block. In regression analysis, Latino/a and non- Latino/a Black youth were less likely to receive caudal regional block than non- Latino/a White patients. CONCLUSIONS We found disparities in the use of pediatric pain management techniques. Understanding mechanisms underlying Latino/a and non- Latino/a Black parental preferences may help providers reduce these disparities.
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Wong JYA, Le S, Lo C, Costandi A, Chernishof V, Kim E. Hyaluronic acid injections for treatment of pediatric sickle cell avascular necrosis of the humeral head. Reg Anesth Pain Med 2021; 47:136-138. [PMID: 34642239 DOI: 10.1136/rapm-2021-102842] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Accepted: 09/22/2021] [Indexed: 11/04/2022]
Abstract
BACKGROUND Avascular necrosis (AVN) can impact up to 50% of patients with sickle cell disease (SCD) and can result in significant pain, decline in physical function and decreased quality of life. While hyaluronic acid (HA) has been used in the adult population for shoulder osteoarthritic pain, we present the first published pediatric case of HA injections in the glenohumeral joint, used to improve function and pain control. CASE PRESENTATION The patient is a 12-year-old woman with SCD, who suffered from chronic pain due to AVN of the humeral and femoral head. Despite engaging in a multidisciplinary pain management plan, she continued to have severe decline in physical functioning and became a wheelchair user. As a result, she was scheduled for a right total hip arthroplasty, which necessitated aggressive postoperative therapies using the glenohumeral joint. To improve this pain and to facilitate postoperative recovery, the patient underwent 4 weekly HA injections into the glenohumeral joint. Over a 2-month period, the patient was able to improve physical functioning, decrease opiate use and participate in all postoperative therapies. CONCLUSION Conservative options to improve functioning and pain are especially important in pediatric patients where it may be desirable to delay surgical interventions until skeletal maturity. Our case report demonstrates the benefits of intra-articular HA as part of a multidisciplinary pain management plan to improve function and decrease pain related to AVN of the humeral head. Future studies should assess the long-term benefits of HA injections for AVN in the setting of SCD.
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