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Ames RS, Li Y, Sarau HM, Nuthulaganti P, Foley JJ, Ellis C, Zeng Z, Su K, Jurewicz AJ, Hertzberg RP, Bergsma DJ, Kumar C. Molecular cloning and characterization of the human anaphylatoxin C3a receptor. J Biol Chem 1996; 271:20231-4. [PMID: 8702752 DOI: 10.1074/jbc.271.34.20231] [Citation(s) in RCA: 204] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
In a human neutrophil cDNA library, an orphan G-protein-coupled receptor, HNFAG09, with 37% nucleotide identity to the C5a receptor (C5a-R, CD88) was identified. A novel feature of this gene, unlike C5a-R and other G-protein-coupled receptors, is the presence of an extraordinarily large predicted extracellular loop comprised of in excess of 160 amino acid residues between transmembrane domains 4 and 5. Northern blot analysis revealed that expression of mRNA for this receptor in human tissues, while similar, was distinct from C5a-R expression. Although there were differences in expression, transcripts for both receptors were detected in tissues throughout the body and the central nervous system. Mammalian cells stably expressing HNFAG09 specifically bound 125I-C3a and responded to a C3a carboxyl-terminal analogue synthetic peptide and to human C3a but not to rC5a with a robust calcium mobilization response. HNFAG09 encodes the human anaphylatoxin C3a receptor.
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Elliott JD, Lago MA, Cousins RD, Gao A, Leber JD, Erhard KF, Nambi P, Elshourbagy NA, Kumar C, Lee JA. 1,3-Diarylindan-2-carboxylic acids, potent and selective non-peptide endothelin receptor antagonists. J Med Chem 1994; 37:1553-7. [PMID: 8201588 DOI: 10.1021/jm00037a003] [Citation(s) in RCA: 113] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
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3
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Bergsma DJ, Ellis C, Kumar C, Nuthulaganti P, Kersten H, Elshourbagy N, Griffin E, Stadel JM, Aiyar N. Cloning and characterization of a human angiotensin II type 1 receptor. Biochem Biophys Res Commun 1992; 183:989-95. [PMID: 1567413 DOI: 10.1016/s0006-291x(05)80288-8] [Citation(s) in RCA: 108] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
A human liver cDNA library was screened using a rat type 1 angiotensin II receptor cDNA coding sequence as a probe. cDNA clones were isolated which encoded a protein of 359 amino acids that shared 94.4% and 95.3% identify to rat and bovine type 1 angiotensin II receptors, respectively. Ligand binding studies of the cloned receptor expressed in COS cells suggested that it is pharmacologically a type 1 angiotensin II receptor subtype. Electrophysiological studies of the receptor expressed in Xenopus laevis oocytes revealed that it could functionally couple to a second messenger system leading to the mobilization of intracellular stores of calcium. Southern and Northern blot analyses indicated that the cloned receptor is represented as a single copy in the human genome and is expressed in many tissues of different histogenic origin with the exception of brain, where mRNA transcripts were barely detectable.
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Chance M, Powers L, Kumar C, Chance B. X-ray absorption studies of myoglobin peroxide reveal functional differences between globins and heme enzymes. Biochemistry 1986; 25:1259-65. [PMID: 3964675 DOI: 10.1021/bi00354a010] [Citation(s) in RCA: 74] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
X-ray absorption studies of myoglobin peroxide show that although it is not identical with compound I or II of horseradish peroxidase [Chance, B., Powers, L., Ching, Y., Poulos, T., Yamazaki, I., & Paul, K. G. (1984) Arch. Biochem. Biophys. 235, 596-611], it has some structural features in common with both. As seen in compound I, the Fe-O distance is short, but the iron-pyrrole nitrogen distance is contracted with a longer iron-histidine distance like compound II. The iron has a higher oxidation state than Fe3+, suggesting an oxyferryl ion type species. Comparison of the structures of various peroxidase and myoglobin compounds points out systematic differences that may explain the catalytic activity of the pi cation radical as well as some of the differences between globins and heme enzymes.
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Powers L, Chance B, Chance M, Campbell B, Friedman J, Khalid S, Kumar C, Naqui A, Reddy KS, Zhou Y. Kinetic, structural, and spectroscopic identification of geminate states of myoglobin: a ligand binding site on the reaction pathway. Biochemistry 1987; 26:4785-96. [PMID: 3663626 DOI: 10.1021/bi00389a028] [Citation(s) in RCA: 69] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Elementary steps or geminate states in the reaction of gaseous ligands with transport proteins delineate the trajectory of the ligand and its rebinding to the heme. By use of kinetic studies of the 765-nm optical "conformation" band, three geminate states were identified for temperatures less than approximately 100 K. MbCO, which is accumulated by photolysis between 1.2 and approximately 10 K, was characterized by our previous optical and X-ray absorption studies [Chance, B., Fischetti, R., & Powers, L. (1983) Biochemistry 22, 3820-3829]. Between 10 and approximately 100 K, geminate states that are also identified that have recombination rates of approximately 10(3) s-1 and approximately 10(-5) s-1 (40 K). Thus, it is possible to maintain a steady-state nearly homogeneous population of the slowest recombining geminate state, Mb, by regulated continuous illumination (optical pumping). Both X-ray absorption and resonance Raman studies under similar conditions of optical pumping show that the heme structure around the iron in Mb is similar to that of MbCO. In both geminate states, the iron-proximal histidine distance remains unchanged (+/- 0.02 A) from that of MbCO while the iron to pyrrole nitrogen average distance has not fully relaxed to that of the deoxy state. In MbCO the CO remains close to iron but not bound, and the Fe...CO angle, which is bent in MbCO (127 +/- 4 degrees C), is decreased by approximately 15 degrees [Powers, L., Sessler, J. L., Woolery, G. L., & Chance, B. (1984) Biochemistry 23, 5519-5523]. The CO molecule in Mb, however, has moved approximately 0.7 A further from iron. Computer graphics modeling of the crystal structure of MbCO places the CO in a crevice in the heme pocket that is just large enough for the CO molecule end-on. Above approximately 100 K resonance Raman studies show that this structure relaxes to the deoxy state.
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Bremner WG, Kumar CM. Delayed surgical emphysema, pneumomediastinum and bilateral pneumothoraces after postoperative vomiting. Br J Anaesth 1993; 71:296-7. [PMID: 8123411 DOI: 10.1093/bja/71.2.296] [Citation(s) in RCA: 60] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
We describe a case of surgical emphysema, pneumomediastinum and bilateral pneumothoraces which occurred some hours after general anaesthesia for a repeat laparoscopy and followed persistent nausea and vomiting. We report the case because of the unexpected and delayed appearance, which led to delay in diagnosis and management. We suggest that this intrathoracic air leak was a consequence of postoperative vomiting rather than a complication of laparoscopy.
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Case Reports |
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Koseoglu S, Lu Z, Kumar C, Kirschmeier P, Zou J. AKT1, AKT2 and AKT3-dependent cell survival is cell line-specific and knockdown of all three isoforms selectively induces apoptosis in 20 human tumor cell lines. Cancer Biol Ther 2014; 6:755-62. [PMID: 17426444 DOI: 10.4161/cbt.6.5.3995] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
AKT is a key serine/threonine kinase in the PTEN/PI3K/AKT pathway(1) and activationof AKT is often observed in human cancers. To explore the role of AKT in cell survival in different tumor cells, we tested 20 human tumor cell lines for response to knockdown of AKT by small interference RNA (siRNA) and/or a kinase-dead mutant AKT. siRNA-mediated knockdown of all three AKT isoforms in tumor cell lines led to a reduction of phosphorylation of AKT substrates. Knockdown of AKT resulted in apoptosis in six out of 11 tumor cells with activated AKT. In contrast, knockdown of AKT induced apoptosis in three out of nine cell lines with a low level of active AKT. The responsiveness of the cells to knockdown of AKT was not affected by mutational status of p53 but appeared correlated with overexpression of HER2. To assess the role of individual AKT isoforms, five of the cell lines responsive to knockdown of AKT were further characterized. In ZR-75 cells, AKT1 is the predominant isoform responsible for cell proliferation and survival. Conversely, in IGROV1 cells, AKT2 plays a major role in cell proliferation, but no single isoform is essential for cell survival. Thus, the relative importance of the AKT isoforms is cell line-specific. Our data suggest that inhibiting all three AKT isoforms is necessary to elicit maximal apoptotic response in tumor cells, and the level of activated AKT is a favorable but not always reliable biomarker for preselection of responsive tumor cell lines to AKT inhibitors.
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Kumar CM, Eid H, Dodds C. Sub-Tenon's anaesthesia: complications and their prevention. Eye (Lond) 2011; 25:694-703. [PMID: 21455245 DOI: 10.1038/eye.2011.69] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
The advent of a new technique that is considered much safer than previously established one leads to its rapid adoption. This usually leads to the identification of previously unreported complications of the new technique, and a re-assessment of its position in clinical care, which is precisely the state of play with the sub-Tenon's block. The sub-Tenon's block was introduced into the clinical practice in early 1990. A systematic recent search of subject headings such as complications of sub-Tenon's block, subtenon, orbital block, orbital block complications, and orbital anaesthesia was performed in Medline, EMBASE, and Cochrane database. Indeed there are complications of sub-Tenon's block published as case reports and the exact incidence of these complications is not known. Management and preventive measures of these complications are described. Although the sub-Tenon's block appears to be relatively safer than needle-based blocks but a proper prospective, randomized, double-blind controlled trial is essential for scientific proof that sub-Tenon's block is better than needle-based blocks.
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Review |
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Phillips G, Garry R, Kumar C, Reich H. How much gas is required for initial insufflation at laparoscopy? ACTA ACUST UNITED AC 2001. [DOI: 10.1046/j.1365-2508.1999.00342.x] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Naqui A, Kumar C, Ching YC, Powers L, Chance B. Structure and reactivity of multiple forms of cytochrome oxidase as evaluated by X-ray absorption spectroscopy and kinetics of cyanide binding. Biochemistry 1984; 23:6222-7. [PMID: 6098312 DOI: 10.1021/bi00320a051] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The extended X-ray absorption fine structure (EXAFS) data show differences between the active site structures of different cytochrome oxidase preparations. In the resting (as isolated) state of the Yonetani preparation, the bridging atom between Fe3+a3 and Cu2+a3 is present [Powers, L., Chance, B., Ching, Y., & Angiolillo, P. (1981) Biophys. J. 34, 465], whereas in another preparation (e.g., Hartzell-Beinert), this atom seems to be bound only to Fe3+a3 in a significant fraction of the molecules. Both preparations bind cyanide in a multiphasic fashion, suggesting that the resting cytochrome oxidase is not homogeneous but rather is a mixture of several forms. The proportion of these forms as detected by cyanide binding kinetics differs for different preparations. However, upon reduction and reoxidation (conversion to the "oxygenated" form) the cyanide binding kinetics become monophasic and all preparations of the oxygenated form bind cyanide at the same rate. Thus, a combination of structural and kinetic approaches seems necessary for evaluation of the nature of the active site of cytochrome oxidase in its various forms.
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Kumar CM, McNeela BJ. Ultrasonic localization of anaesthetic fluid using sub-Tenon's cannulae of three different lengths. Eye (Lond) 2003; 17:1003-7. [PMID: 14704749 DOI: 10.1038/sj.eye.6700501] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
PURPOSE To study the distribution of anaesthetic fluid during sub-Tenon's block by B-scan ultrasonography using cannulae of three different lengths. METHODS A total of 30 patients undergoing routine phacoemulsification and lens implantation were studied after informed consent had been obtained. Ages ranged from 60 to 92 years and globe axial lengths from 21.50 to 27.00 mm. All were given a sub-Tenon's block and the patients were classified into three groups in which either a long, intermediate, or short cannula was used. B-scan ultrasonography was performed before administration of the anaesthetic agent, during injection, and 2 min after completion of the injection. RESULTS In all patients the optic nerve was identified. During the injection, anaesthetic fluid could be seen tracking behind the globe and opening up the posterior sub-Tenon's space (the previously described 'T'-sign). After 2 min very little or no fluid was seen, suggesting that it had dispersed into the surrounding tissues. There was no discernible difference in the distribution of fluid or in the quality of the block in the three groups. CONCLUSIONS B-scan ultrasonography can reliably identify the distribution of anaesthetic fluid during sub-Tenon's block. Anaesthetic agents can be successfully delivered into the sub-Tenon's space by long, intermediate, or short cannulae.
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Okuda M, Lee HC, Kumar C, Chance B. Comparison of the effect of a mitochondrial uncoupler, 2,4-dinitrophenol and adrenaline on oxygen radical production in the isolated perfused rat liver. ACTA PHYSIOLOGICA SCANDINAVICA 1992; 145:159-68. [PMID: 1322018 DOI: 10.1111/j.1748-1716.1992.tb09351.x] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Using the isolated perfused rat liver, we examined the effect of stimulation of mitochondrial respiration by 2,4-dinitrophenol (2,4-DNP) and adrenaline on reactive oxygen species (ROS) production, liver damage and lipid peroxidation. ROS production was monitored by luminol- and lucigenin-enhanced chemiluminescence and oxygen uptake was measured simultaneously. Liver damage and lipid peroxidation were evaluated by measuring hepatic lactate dehydrogenase (LDH) and thiobarbituric acid reacting substances (TBARS) release. Tissue ROS level decreased and oxygen uptake increased soon after 2,4-DNP infusion. On termination of 2,4-DNP infusion, there was a sharp increase in lucigenin-enhanced chemiluminescence, which declined slowly, but luminol-enhanced chemiluminescence did not change prominently. Hepatic LDH and TBARS release increased gradually during 2,4-DNP infusion and were manifested by termination of the infusion. Allopurinol did not affect ROS production and TBARS release, but delayed increases in LDH release after termination of 2,4-DNP infusion. Adrenaline, which stimulates mitochondrial respiration without uncoupling caused similar but smaller ROS changes observed in 2,4-DNP. LDH and TBARS release were not affected significantly by adrenaline infusion. These results indicate that uncoupling of oxidative phosphorylation decreases ROS production and restoration of oxidative phosphorylation enhances ROS production and liver damage. Xanthine oxidase is unlikely to contribute to enhanced ROS production after termination of 2,4-DNP but has some protective effect during uncoupling.
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Comparative Study |
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Urbinati C, Mitola S, Tanghetti E, Kumar C, Waltenberger J, Ribatti D, Presta M, Rusnati M. Integrin alphavbeta3 as a target for blocking HIV-1 Tat-induced endothelial cell activation in vitro and angiogenesis in vivo. Arterioscler Thromb Vasc Biol 2005; 25:2315-20. [PMID: 16166568 DOI: 10.1161/01.atv.0000186182.14908.7b] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVE The transactivating factor (Tat) of HIV-1 binds to alphavbeta3 integrin present on endothelial cells contributing to neovascularization. Here, we investigated the biological consequences of Tat/alphavbeta3 interaction and the antagonist effect of an Arg-Gly-Asp (RGD)-based peptidomimetic. METHODS AND RESULTS Binding of Tat to endothelial alphavbeta3 triggers focal adhesion kinase and nuclear factor-kappaB activation, leading to endothelial cell proliferation, membrane ruffling, and motility in vitro and neovascularization in vivo. The RGD-peptidomimetic SCH221153 inhibits Tat/alphavbeta3 interaction in a solid phase binding assay and endothelial cell adhesion to immobilized Tat with a potency higher than that of RGD-containing peptides. Accordingly, SCH221153 inhibits Tat/alphavbeta3-dependent focal adhesion kinase and nuclear factor-kappaB activation, proliferation, membrane ruffling, and motility in endothelial cells. Finally, SCH221153 inhibits the angiogenic response triggered by Tat in the chick-embryo chorioallantoic membrane without affecting physiological vascularization. SCH221153 exerts these inhibitory effects without affecting the interaction of Tat with endothelial heparan sulfate proteoglycans or with the vascular endothelial growth factor receptor-2/kinase domain-containing receptor. In all the assays the negative control SCH216687 was ineffective. CONCLUSIONS These data provide new insights on the mechanism of endothelial cell activation by Tat and point to RGD peptidomimetics as prototypes for the development of novel Tat antagonists.
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MESH Headings
- Animals
- Aorta/cytology
- Benzimidazoles/pharmacology
- Cattle
- Cell Line, Transformed
- Chick Embryo
- Chickens
- Endothelium, Vascular/cytology
- Endothelium, Vascular/drug effects
- Endothelium, Vascular/virology
- Gene Products, tat/antagonists & inhibitors
- Gene Products, tat/metabolism
- HIV Infections/drug therapy
- HIV Infections/metabolism
- HIV Infections/physiopathology
- HIV-1
- Humans
- In Vitro Techniques
- Integrin alphaVbeta3/metabolism
- Neovascularization, Pathologic/drug therapy
- Neovascularization, Pathologic/metabolism
- Neovascularization, Pathologic/virology
- Oligopeptides/metabolism
- Peptide Fragments/antagonists & inhibitors
- Peptide Fragments/metabolism
- Signal Transduction/drug effects
- Swine
- Umbilical Veins/cytology
- tat Gene Products, Human Immunodeficiency Virus
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Research Support, Non-U.S. Gov't |
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Abstract
Serious complications following orbital regional anesthesia are rare, but occur following both needle and blunt cannula (sub-Tenon's) techniques. Each technique of orbital regional anesthesia has its own risk/benefit profile. This article reviews the etiology, risk factors, treatment and prevention of complications of commonly used akinetic orbital blocks. Ophthalmologists and ophthalmic anesthesiologists must be prepared to deal with rare, but serious complications, that can occur with any technique of orbital regional anesthesia.
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Abstract
The place of sub-Tenon's block in ophthalmic surgery is now established. This block was introduced into clinical practice in the early 1990s as a simple, safe and effective technique. Since then, techniques have evolved, newer cannulae have been introduced and many complications, both minor as well as major, have been reported. This review deals with the recent developments in sub-Tenon's block.
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Chance B, Kumar C, Powers L, Ching YC. "Peroxidatic" form of cytochrome oxidase as studied by X-ray absorption spectroscopy. Biophys J 1983; 44:353-63. [PMID: 6318841 PMCID: PMC1434835 DOI: 10.1016/s0006-3495(83)84309-4] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
X-ray absorption spectroscopy shows pulsed oxidase to be similar to resting oxidase but to lack the sulfur bridge between iron and copper of active sites (Powers, L., Y. Ching, B. Chance, and B. Muhoberac, 1982, Biophys. J., 37[2, Pt. 2]: 403a. [Abstr.] ) The first shell ligands and bond lengths of the pulsed oxidase active site heme most clearly fit the ferric peroxidases from horseradish and yeast, and the pulsed oxidase cyanide compound resembles the low spin hemoprotein cyanide compounds. The structural results are consistent with an aquo or a peroxo form for pulsed oxidase as is also observed by optical studies. These structural and chemical data are consistent with a role for the pulsed forms in a cyclic peroxidatic side reaction in which the pulsed and pulsed peroxide compounds act as peroxide scavengers. The peroxidatic role of cytochrome oxidase in the nonsulfur bridged form suggests the renaming of the "oxygenated" or "pulsed" forms on a functional basis as "peroxidatic" forms of cytochrome oxidase.
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research-article |
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Daouti S, Latario B, Nagulapalli S, Buxton F, Uziel-Fusi S, Chirn GW, Bodian D, Song C, Labow M, Lotz M, Quintavalla J, Kumar C. Development of comprehensive functional genomic screens to identify novel mediators of osteoarthritis. Osteoarthritis Cartilage 2005; 13:508-18. [PMID: 15922185 DOI: 10.1016/j.joca.2005.02.003] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/17/2004] [Accepted: 02/06/2005] [Indexed: 02/02/2023]
Abstract
OBJECTIVE The aim of this study was to develop high-throughput assays for the analysis of major chondrocyte functions that are important in osteoarthritis (OA) pathogenesis and methods for high-level gene expression and analysis in primary human chondrocytes. METHODS In the first approach, complementary DNA (cDNA) libraries were constructed from OA cartilage RNA and full-length clones were selected. These cDNAs were transferred into a retroviral vector using Gateway Technology. Full-length clones were over-expressed in human articular chondrocytes (HAC) by retroviral-mediated gene transfer. The induction of OA-associated markers, including aggrecanase-1 (Agg-1), matrix metalloproteinase-13 (MMP-13), inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), collagen IIA and collagen X was measured by quantitative real-time polymerase chain reaction (QPCR). Induction of a marker gene was verified by independent isolation of 2-3 clones per gene, re-transfection followed by QPCR as well as nucleotide sequencing. In the second approach, whole cDNA libraries were transduced into chondrocytes and screened for chondrocyte cluster formation in three-dimensional agarose cultures. RESULTS Using green fluorescent protein (eGFP) as a marker gene, it was shown that the retroviral method has a transduction efficiency of >90%. A total of 40 verified hits were identified in the QPCR screen. The first set of 19 hits coordinately induced iNOS, COX-2, Agg-1 and MMP-13. The most potent of these genes were the tyrosine kinases Axl and Tyro-3, receptor interacting kinase-2 (RIPK2), tumor necrosis factor receptor 1A (TNFR1A), fibroblast growth factor (FGF) and its receptor FGFR, MUS81 endonuclease and Sentrin/SUMO-specific protease 3. The second set of seven hits induced both Agg-1 and MMP-13 but none of the other markers. Five of these seven genes regulate the phosphoinositide-3-kinase pathway. The most potently induced OA marker was iNOS. This marker was induced 20-500 fold by seven genes. Collagen IIA was also induced by seven genes, the most potent being transforming growth factor beta (TGFbeta)-stimulated protein TSC22, vascular endothelial growth factor (VEGF) and splicing factor 3a. This screening assay did not identify inducers of collagen X. The second chondrocyte cluster formation screen identified 14 verified hits. Most of the genes inducing cluster formation were kinases. Additional genes had not been previously known to regulate chondrocyte cluster formation or any other chondrocyte function. CONCLUSIONS The methods developed in this study can be applied to screen for genes capable of inducing an OA-like phenotype in chondrocytes on a genome-wide scale and identify novel mediators of OA pathogenesis. Thus, coordinated functional genomic approaches can be used to delineate key genes and pathways activated in complex human diseases such as OA.
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Kumar V, Kumar C, Raghunathan P. Studies on lecithin reverse micelles: Optical birefringence, viscosity, light scattering, electrical conductivity, and electron microscopy. J Colloid Interface Sci 1984. [DOI: 10.1016/0021-9797(84)90118-8] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Okuda M, Ikai I, Chance B, Kumar C. Oxygen radical production during ischemia-reperfusion in the isolated perfused rat liver as monitored by luminol enhanced chemiluminescence. Biochem Biophys Res Commun 1991; 174:217-21. [PMID: 1989601 DOI: 10.1016/0006-291x(91)90508-5] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
We have applied the Luminol enhanced chemiluminescence technique to the isolated perfused rat liver during ischemia and reperfusion to monitor the production of oxygen radicals in tissue. Livers under perfusion with Luminol-containing buffer were subjected to 30 minutes of global ischemia followed by 60 minutes of reperfusion. Their chemiluminescence was continuously monitored to obtain the time course of oxygen radical production. Transient bursts of oxygen radical production were observed in the livers as indicated by chemiluminescence changes on reperfusion. Superoxide dismutase treatment abolished while catalase treatment enhanced the reperfusion-induced chemiluminescence transient.
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Prasad N, Kumar CM, Patil BB, Dowd TC. Subjective visual experience during phacoemulsification cataract surgery under sub-Tenon's block. Eye (Lond) 2003; 17:407-9. [PMID: 12724704 DOI: 10.1038/sj.eye.6700370] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
In a prospective survey, 121 patients received sub-Tenon's block and were interviewed on the same day after their phacoemulsification cataract surgery regarding their visual experience in the operated eye during surgery. Majority of patients (81%) reported that they could see some light during surgery and various colours were seen by 56%. Movements of various descriptions were also reported by 40% of patients. The majority of patients (93%) found the visual experience acceptable but 4% thought it to be unpleasant and 3% found it frightening. Patients undergoing phacoemulsification surgery under sub-Tenon's block experience a variety of visual sensations and some patients may be frightened. All patients should receive appropriate preoperative warning.
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Abstract
A prospective, randomized blind study was conducted in 40 patients undergoing phacoemulsification and posterior chamber intraocular lens implantation. They received anaesthetic infiltration of 2% lidocaine with 1:200,000 epinephrine and hyaluronidase 150 U ml(-1) in a volume of 2, 3, 4 or 5 ml into the sub-Tenon's fascial space through a Greenbaum cannula after a conjunctival incision. Reduction of ocular movements, anaesthesia, pain on injection and any incidental complications were recorded. Akinesia and anaesthesia occurred within 5 min with 4 and 5 ml of local anaesthetic, and no supplementary injections were required. There were marked reductions in the frequency of forced eyelid movements with these volumes. Chemosis and conjunctival haemorrhage were noted in the majority of patients but caused no intraoperative problems. Approximately 10-15% of patients reported slight discomfort at the time of injection. Four to 5 ml of 2% lidocaine with 1:200,000 epinephrine and 150 U ml(-1) of hyaluronidase is the optimum volume to achieve adequate akinesia, anaesthesia and reduction of lid movements during the Greenbaum sub-Tenon's block.
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Clinical Trial |
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Newton RA, Phipps SL, Flanigan TP, Newberry NR, Carey JE, Kumar C, McDonald B, Chen C, Elliott JM. Characterisation of human 5-hydroxytryptamine2A and 5-hydroxytryptamine2C receptors expressed in the human neuroblastoma cell line SH-SY5Y: comparative stimulation by hallucinogenic drugs. J Neurochem 1996; 67:2521-31. [PMID: 8931486 DOI: 10.1046/j.1471-4159.1996.67062521.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Stable transfection of the human neuroblastoma cell line SH-SY5Y with the human 5-hydroxytryptamine2A (5-HT2A) or 5-HT2C receptor cDNA produced cell lines demonstrating ligand affinities that correlated closely with those for the corresponding endogenous receptors in human frontal cortex and choroid plexus, respectively. Stimulation of the recombinant receptors by 5-HT induced phosphoinositide hydrolysis with higher potency but lower efficacy at the 5-HT2C receptor (pEC50 = 7.80 +/- 0.06) compared with the 5-HT2A receptor (pEC50 = 7.30 +/- 0.08). Activation of the 5-HT2A receptor caused a transient fourfold increase in intracellular Ca2+ concentration. Whole-cell recordings of cells clamped at -50 mV demonstrated a small inward current (2 pA) in response to 10 microM 5-HT for both receptors. There were no differences in potency or efficacy of phosphoinositide hydrolysis among four hallucinogenic [d-lysergic acid diethylamide (LSD), 1-(4-iodo-2,5-dimethoxyphenyl)-2-aminopropane (DOI), 5-methoxy-N,N-dimethyltryptamine, and mescaline] and three nonhallucinogenic drugs (m-chlorophenylpiperazine, quipazine, and ergotamine). Comparison of equipotent doses producing 20% of the maximal response induced by 5-HT revealed selective activation of the 5-HT2A receptor by LSD and to a lesser degree by DOI, mescaline, and ergotamine. Quipazine and 5-methoxy-N,N-dimethyltryptamine were relatively nonselective, whereas m-chlorophenylpiperazine selectively activated the 5-HT2C receptor. It is unlikely therefore that hallucinosis is mediated primarily by activity at the 5-HT2C receptor, whereas activity at the 5-HT2A receptor may represent an important but not unique mechanism associated with hallucinogenic drug action.
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Kumar C, Balasubramanian D. Spectroscopic studies on the microemulsions and lamellar phases of the system triton X-100:hexanol:water in cyclohexane. J Colloid Interface Sci 1980. [DOI: 10.1016/0021-9797(80)90170-8] [Citation(s) in RCA: 35] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Chakraborty S, Garg P, Ramamurthy T, Thungapathra M, Gautam JK, Kumar C, Maiti S, Yamasaki S, Shimada T, Takeda Y, Ghosh A, Nair GB. Comparison of antibiogram, virulence genes, ribotypes and DNA fingerprints of Vibrio cholerae of matching serogroups isolated from hospitalised diarrhoea cases and from the environment during 1997-1998 in Calcutta, India. J Med Microbiol 2001; 50:879-888. [PMID: 11599737 DOI: 10.1099/0022-1317-50-10-879] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
This study identified 17 matching serogroups of Vibrio cholerae belonging to serogroups other than O1 and O139 isolated from human cases and from the environment during a concurrent clinical and environmental study conducted in Calcutta, a cholera endemic area. Isolates within these matching serogroups were compared by various phenotypic and genotypic traits to determine if the environment was the source of the organisms associated with the disease. Clinical strains of V. cholerae were resistant to a greater number of drugs and exhibited multi-drug resistance compared with their environmental counterparts. Except for the presence of the genes for the El Tor haemolysin and the regulatory element ToxR in most of the strains of V. cholerae examined, non-O1, non-O139 V. cholerae strains lacked most of the other known virulence traits associated with toxigenic V. cholerae O1 or O139. Restriction fragment-length polymorphism of virulence-associated genes, ribotypes and DNA fingerprints of strains of matched serogroups showed considerable diversity, although some gene polymorphisms and ribotypes of a few strains of different serogroups were similar. It is concluded that despite sharing the same serogroup, environmental and clinical isolates were genetically heterogeneous and were of different lineages.
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