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Subramanian V, Chitra K, Sivanesan D, Amutha R, Sankar S. Ab initio potential energy surface of the Ne…CO complex. Chem Phys Lett 1999. [DOI: 10.1016/s0009-2614(99)00561-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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252
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Sivanesan D, Amutha R, Subramanian V, Nair B, Ramasami T. Assessment of the importance of the solvent in the calculation of condensed Fukui function: a self-consistent reaction field calculation study. Chem Phys Lett 1999. [DOI: 10.1016/s0009-2614(99)00587-4] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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253
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Subramanian V, Sivanesan D, Padmanabhan J, Lakshminarayanan N, Ramasami T. Atoms in molecules: Application to electronic structure of van der Waals complexes. J CHEM SCI 1999. [DOI: 10.1007/bf02871917] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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254
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Ramamoorthy U, Subramanian V, Ramasami T. Viscoelastic behavior of formaldehyde and basic chromium sulfate-crosslinked collagen. J Appl Polym Sci 1999. [DOI: 10.1002/(sici)1097-4628(19990328)71:13<2245::aid-app15>3.0.co;2-i] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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255
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Ramanathan AL, Subramanian V, Ramesh R, Chidambaram S, James A. Environmental geochemistry of the Pichavaram mangrove ecosystem (tropical), southeast coast of India. ACTA ACUST UNITED AC 1999. [DOI: 10.1007/s002540050380] [Citation(s) in RCA: 103] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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256
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Subramanian V, Meyer B, Evans GS. The murine Cdx1 gene product localises to the proliferative compartment in the developing and regenerating intestinal epithelium. Differentiation 1998; 64:11-8. [PMID: 9921649 DOI: 10.1046/j.1432-0436.1998.6410011.x] [Citation(s) in RCA: 71] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The mouse Cdx1 gene encodes a homeobox-containing transcription factor and is one of the few homeobox genes known to be expressed in endodermally derived tissues of the intestine in fetal and adult mice. A detailed and systematic study of the expression of the Cdx1 protein was carried out during embryonic intestinal development, postnatal cytodifferentiation and in the regenerating (after radiation-induced damage) intestine of the mouse. Using antibodies directed against Cdx1, we show for the first time that the Cdx1 protein is localised in the proliferating immature epithelium during intestinal development. It becomes restricted to the proliferative crypt compartment during postnatal differentiation, as well as in the adult intestine. The mesenchymal layer was completely negative both during embryonic development and in the postnatal intestine. The expression of the protein was first clearly detected throughout the simple columnar epithelium at day 15 of development. This expression progressively became restricted to the regions of epithelial proliferation in the crypts of the adult mouse by day 40 of post-natal development. There were occasional cells that were Cdx1 positive in the villi. During regeneration of the epithelium after radiation-induced damage, Cdx1 expression diminished during the initial phase of cellular regression. The expression was then very strong in the regenerating epithelial foci, but not in the quiescent sterilised crypts between day 4 and 6. The normal pattern was restored between day 6 and 7. The Paneth cells were negative. The physical segregation of Cdx1 with the proliferative compartment and the hierarchy of cell renewal in the intestinal epithelium is an important example of how regulatory genes function in the maintenance and in the dysfunction of renewing tissues.
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Subramanian V, Sivanesan D, Ramasami T. Electronic structure of Ne–H–Cl and Ne–Cl–H using the G1, G2 and MP4 methods. Chem Phys Lett 1998. [DOI: 10.1016/s0009-2614(98)00948-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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259
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Subramanian V, Sivanesan D, Amutha R, Padmanabhan J, Ramasami T. Hardness profile of interaction of H–F with He, Ne and Ar: a density functional and MP2 calculation. Chem Phys Lett 1998. [DOI: 10.1016/s0009-2614(98)00859-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Subramanian V, Sivanesan D, Ramasami T. The role of solvent on the base stacking properties of the stacked cytosine dimer. Chem Phys Lett 1998. [DOI: 10.1016/s0009-2614(98)00458-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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261
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Subramanian V, Ramasami T. Comparison of electronic structure of group IV A tetrahalides using MS-Xα calculations. J CHEM SCI 1997. [DOI: 10.1007/bf02875976] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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262
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Subramanian V. Density functional calculations of Van der Waals clusters: NeN+2 as a case study. Chem Phys Lett 1997. [DOI: 10.1016/s0009-2614(97)00821-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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263
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Subramanian V, Venkatesh K, Prabha D, Ramasami T. Density functional calculations of Van der Waals clusters: NeN2+ as a case study. Chem Phys Lett 1997. [DOI: 10.1016/s0009-2614(97)88027-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
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264
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Subramanian V, Shankaranarayanan C, Nair BU, Kanthimathi M, Manickkavachagam R, Ramasami T. Development of a force field for some copper(II) Schiff-base complexes. Chem Phys Lett 1997. [DOI: 10.1016/s0009-2614(97)00663-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Subramanian V, Anstead M, Cottrill CM, Kanga J, Gurley J. Tetralogy of Fallot with absent pulmonary valve and bronchial compression: treatment with endobronchial stents. Pediatr Cardiol 1997; 18:237-9. [PMID: 9142722 DOI: 10.1007/s002469900163] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Absent pulmonary valve syndrome (APVS) is a rare congenital cardiac lesion. The lesion includes ventricular septal defect, overriding aorta, and absence of the pulmonary valve, with resultant pulmonary incompetence. It has been suggested that the pulmonary incompetence induces intrauterine dilatation of the pulmonary artery, which leads to tracheobronchial compression. One of the presenting features in infants with APVS is severe airway obstruction, which may be difficult to manage. We report an infant who benefited from bilateral endobronchial endoscopic stent placement.
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Chakrapani GJ, Subramanian V. Fractionation of heavy metals and phosphorus in suspended sediments of the Yamuna river, India. ENVIRONMENTAL MONITORING AND ASSESSMENT 1996; 43:117-124. [PMID: 24193820 DOI: 10.1007/bf00398602] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
The Yamuna river is the largest tributary of the Ganges river system. It originates in the Himalayas and flows through a varied geological terrain encompassing a large basin area. Metals Fe, Mn, Pb, Zn, Cu in different chemical fractions of suspended sediments such as exchangeable, carbonates, Fe-Mn oxides, organics and residual fractions were studied. Phosphorus associated with different chemical forms are discussed. The metals are mostly associated with residual fractions in the sediments followed by organics, Fe-Mn oxides, exhangeable and carbonates. Intensive use of chemical fertilizers and pesticides in agriculture in the basin affects the high inorganic phosphorus content in sediments.
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Abstract
The relative bioavailabilities of orally administered nicardipine (Zenith Laboratories) and nicardipine (Cardene Syntex Laboratories) were compared following a single 30 mg dose under fasted conditions using a two-way crossover study with 34 healthy adult male subjects. In a separate study the effect of food on the relative bioavailabilities of these products was assessed following an identical dose by comparing the Zenith product under fasted conditions, the Zenith product under fed conditions, and the Syntex product under fed conditions using a three-way crossover study with 17 healthy adult male subjects. In the fasted study, 90% confidence intervals surrounding ratios (Zenith/Syntex) of least-squares means derived from 1n-transformed data were 0.84-1.02 for AUCt, 0.85-1.04 for AUCinfinity, and 0.86-1.05 for Cmax, clearly demonstrating bioequivalence of the two products. In the food-effect study ratios of least-squares means (Zenith under fed conditions/Zenith under fasted conditions) were 0.62 for AUCt, 0.65 for AUCinfinity, and 0.40 for Cmax, with tmax delayed from 0.906 +/- 0.337 h (Zenith under fasted conditions) to 2.33 +/- 0.717 h (Zenith under fed conditions) and 2.84 +/- 0.834 h (Syntex under fed conditions). Findings indicate that the presence of food in the gastrointestinal tract reduces the bioavailability of orally administered nicardipine. However, ratios under fed conditions (Zenith/Syntex) were very close to unity for each metric, suggesting that the observed food effect is independent of the product formulation. Findings further suggested that food effects on conventional pharmacokinetic metrics might be attributed to alteration of extent, rather than rate, of gastrointestinal absorption. Finally, these results question the applicability of the peak plasma concentration (Cmax) as an index of absorption rate in nicardipine studies.
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Rajan R, Subramanian V, Nair BU, Ramasami T. Force field calculation on the structure of transition metal complexes: Application to schiff-base complexes of Ti(IV). J CHEM SCI 1996. [DOI: 10.1007/bf02870101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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269
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Subramanian V, Ramanathan AL. Nature of Sediment Load in the Ganges-Brahmaputra River Systems in India. COASTAL SYSTEMS AND CONTINENTAL MARGINS 1996. [DOI: 10.1007/978-94-015-8719-8_8] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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270
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Subramanian V, Meyer BI, Gruss P. Disruption of the murine homeobox gene Cdx1 affects axial skeletal identities by altering the mesodermal expression domains of Hox genes. Cell 1995; 83:641-53. [PMID: 7585967 DOI: 10.1016/0092-8674(95)90104-3] [Citation(s) in RCA: 287] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Cdx1 is expressed along the embryonic axis from day 7.5 postcoitum until day 12, by which time the anterior limit of expression has regressed from the hindbrain level to the forelimb bud region. To assign a functional role for Cdx1 in murine embryonic development, we have inactivated the gene via homologous recombination. Viable fertile homozygous mutant mice were obtained that show anterior homeotic transformations of vertebrae. These abnormalities were concomitant with posterior shifts of Hox gene expression domains in the somitic mesoderm. The presence of putative Cdx1-binding sites in Hox gene control regions as well as in vitro transactivation of Hoxa-7 indicates a direct regulation.
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Brown WE, Nobile V, Subramanian V, Shapiro R. The mouse angiogenin gene family: structures of an angiogenin-related protein gene and two pseudogenes. Genomics 1995; 29:200-6. [PMID: 8530072 DOI: 10.1006/geno.1995.1232] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Angiogenin, a homologue of pancreatic ribonuclease, is a potent inducer of blood vessel formation. As an initial step toward investigating the in vivo functional role of this protein via gene disruption, we undertook the isolation of the angiogenin gene (Ang) from the 129 strain mouse, which will be used for generating targeting constructs. Unexpectedly, screening of a genomic library with an Ang gene probe obtained previously from the BALB/c strain yielded two new genes closely similar to Ang rather than Ang itself. One of these encodes a protein with 78% sequence identity to angiogenin and is designated "Angrp" for "angiogenin-related protein." The ribonucleolytic active site of angiogenin, which is critical for angiogenic activity, is completely conserved in Angrp, whereas a second essential site, thought to bind cellular receptors, is considerably different. Thus, the Angrp product may have a function distinct from that of angiogenin. The second gene obtained by library screening is a pseudogene, designated "Ang-ps1," that contains a frameshift mutation in the early part of the coding region. Although the Ang gene was not isolated from this library, it was possible to amplify this gene from 129 mouse genomic DNA by the polymerase chain reaction (PCR). Sequence analysis showed that the 129 strain Ang gene is identical to the BALB/c gene throughout the coding region. PCR cloning also yielded a second Ang-like pseudogene, designated "Ang-ps2." Southern blotting of genomic DNA confirmed the presence of Ang, Angrp, and at least one of the pseudogenes in an individual mouse and suggested that the mouse Ang gene family may contain more than the four members identified here.
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Gupta LP, Subramanian V. Environmental geochemistry of the River Gomti: A tributary of the Ganges River. ACTA ACUST UNITED AC 1994. [DOI: 10.1007/bf00767084] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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273
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Murali K, Subramanian V, Rangarajan N, Lakshmanan A, Rangarajan S. Brush plated CdSe films and their photoelectrochemical characteristics. J Electroanal Chem (Lausanne) 1994. [DOI: 10.1016/0022-0728(93)03090-c] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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274
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Subramanian V. Phosphorus, Silicon, and Some Trace Contaminants in the Ganges Estuary. ACTA ACUST UNITED AC 1993. [DOI: 10.2307/1352593] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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275
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Jha PK, Vaithiyanathan P, Subramanian V. Mineralogical characteristics of the sediments of a Himalayan river: Yamuna River ? a tributary of the Ganges. ACTA ACUST UNITED AC 1993. [DOI: 10.1007/bf00775279] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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276
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Ramanathan AL, Vaithiyanathan P, Subramanian V, Das BK. Geochemistry of the Cauvery Estuary, East Coast of India. ACTA ACUST UNITED AC 1993. [DOI: 10.2307/1352594] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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277
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Acharya KR, Subramanian V, Shapiro R, Riordan JF, Vallee BL. Crystallization and preliminary X-ray analysis of human angiogenin. J Mol Biol 1992; 228:1269-70. [PMID: 1474591 DOI: 10.1016/0022-2836(92)90333-f] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Crystals of recombinant human angiogenin have been grown from solutions containing sodium potassium tartrate and polyethylene glycol as precipitants. They belong to the space group C222(1) (a = 83.36 A, b = 120.64 A, c = 37.72 A) and contain a single molecule in the asymmetric unit. The crystals diffract to at least 2.3 A resolution and are suitable for three-dimensional X-ray structural analysis.
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Schaefer WP, Subramanian V, Myers AG. Structure of an 11-membered cyclic silyl enol ether from condensation of methacrolein and a pseudoephedrine-derived O-silyl ketene N,O-acetal. Acta Crystallogr C 1992. [DOI: 10.1107/s0108270192006851] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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279
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Mbugua S, Ahrens R, Kigutha H, Subramanian V. Effect of fermentation, malted flour treatment and drum drying on nutritional quality of uji. Ecol Food Nutr 1992. [DOI: 10.1080/03670244.1992.9991280] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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280
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Pitchumani K, Subramanian V, Jegatheesan PP, Srinivasan C. Kinetics and mechanism of oxidation of N-substituted phenothiazines by chromium(VI). J CHEM SCI 1992. [DOI: 10.1007/bf02843527] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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281
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Naresh MD, Subramanian V, Arumugam V, Sanjeevi R. A study on the mechanism of failure in keratin. Colloid Polym Sci 1991. [DOI: 10.1007/bf00659913] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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282
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Murali K, Subramanian V, Rangarajan N, Lakshmanan A, Rangarajan S. Photoelectrochemical studies on pulse plated CdSe films. J Electroanal Chem (Lausanne) 1991. [DOI: 10.1016/0022-0728(91)85132-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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283
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284
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Rajagopalan V, Subramanian V. An analysis of laminar forced convection film boiling. CAN J CHEM ENG 1989. [DOI: 10.1002/cjce.5450670623] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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285
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Subramanian V. A malignant, stem cell-like somatic hybrid between a mouse teratocarcinoma and a rat ascitic hepatoma is differentiation competent. CELL DIFFERENTIATION AND DEVELOPMENT : THE OFFICIAL JOURNAL OF THE INTERNATIONAL SOCIETY OF DEVELOPMENTAL BIOLOGISTS 1989; 27:197-214. [PMID: 2478269 DOI: 10.1016/0922-3371(89)90700-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
A hybrid clone was developed by the fusion of a pluripotent mouse teratocarcinoma cell line PCC-4 AzaR to the Zajdela ascitic hepatoma (ZAH) of rat origin. This hybrid cell line, F2231A, possessed a predominantly teratocarcinoma morphology with a large nucleus and prominent nucleoli, and grew in nests. F2231A cells formed undifferentiated tumours in irradiated Sv/129 mice. It formed aggregates when subcultured at high densities in bacteriological Petri dishes. The hybrid cell line differentiated in response to retinoic acid and also underwent spontaneous differentiation upon overgrowth. Karyological analysis showed the presence of several rat chromosomes in the hybrid and upon isozyme analysis it was found that only the rat variant of the X-linked enzyme HGPRT was expressed. Analysis of the genomic DNA with a cloned probe, specific for rat repetitive sequences, gave strong positive signals in the hepatoma parent and F2231A cells while the parental embryonal carcinoma (EC) cells were negative. The hybrid cell line, like the PCC-4 cells, expressed the SSEA-1 surface marker but not SSEA-3, intercellular fibronectin and EGF receptors. Upon differentiation of F2231A cells there was a loss of expression of SSEA-1. The mRNA for alpha-fetoprotein was expressed by the hybrid cell line and in this respect it resembled the hepatoma parent. Albumin mRNA was not detectable in the hybrid cell line. The mRNA for the transformation-related protein, p53, was expressed at a high level in F2231A cells. The hybrid cell line F2231A retained several of the biochemical and immunological properties of the teratocarcinoma cells.
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Subramanian V, Ali AM. Milk plasma supports growth and differentiation of a mouse teratocarcinoma cell line. IN VITRO CELLULAR & DEVELOPMENTAL BIOLOGY : JOURNAL OF THE TISSUE CULTURE ASSOCIATION 1989; 25:391-2. [PMID: 2732192 DOI: 10.1007/bf02624620] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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287
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Subramanian V, Grieken R, Dack L. Heavy metals distribution in the sediments of ganges and Brahmaputra rivers. ACTA ACUST UNITED AC 1987. [DOI: 10.1007/bf02449940] [Citation(s) in RCA: 64] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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288
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Subramanian V, Liu TN, Yeh WK, Serdar CM, Wackett LP, Gibson DT. Purification and properties of ferredoxinTOL. A component of toluene dioxygenase from Pseudomonas putida F1. J Biol Chem 1985; 260:2355-63. [PMID: 2982815] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Toluene dioxygenase oxidizes toluene to (+)-cis-1(S),2(R)-dihydroxy-3-methylcyclohexa-3,5-diene. This reaction is catalyzed by a multienzyme system that is induced in cells of Pseudomonas putida F1 during growth on toluene. One of the components of toluene dioxygenase has been purified to homogeneity and shown to be an iron-sulfur protein that has been designated ferredoxinTOL. The molecular weight of ferredoxinTOL was calculated to be 15,300, and the purified protein was shown to contain 2 g of atoms each of iron- and acid-labile sulfur which appear to be organized as a single [2Fe-2S]cluster. Solutions of ferredoxinTOL were brown in color and showed absorption maxima at 277, 327, and 460 nm. A shoulder in the spectrum of the oxidized protein was discernible at 575 nm. Reduction with sodium dithionite or NADH and ferredoxinTOL reductase resulted in a decrease in visible absorbance at 460 and 575 nm, with a concomitant shift in absorption maxima to 382 and 438 nm. The redox potential of ferredoxinTOL was estimated to be -109 mV. In the oxidized state, the protein is diamagnetic. However, upon reduction it exhibited prominent electron paramagnetic resonance signals with anisotropy in g values (gx = 1.81, gy = 1.86, and gz = 2.01). Anaerobic reductive titrations revealed that ferredoxinTOL is a one-electron carrier that accepts electrons from NADH in a reaction that is mediated by a flavoprotein (ferredoxinTOL reductase). The latter is the first component in the toluene dioxygenase system. Reduced ferredoxinTOL can transfer electrons to cytochrome c or to a terminal iron-sulfur dioxygenase (ISP-TOL) which catalyzes the incorporation of molecular oxygen into toluene and related aromatic substrates.
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Subramanian V, Liu TN, Yeh WK, Serdar CM, Wackett LP, Gibson DT. Purification and properties of ferredoxinTOL. A component of toluene dioxygenase from Pseudomonas putida F1. J Biol Chem 1985. [DOI: 10.1016/s0021-9258(18)89561-8] [Citation(s) in RCA: 78] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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290
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Finette BA, Subramanian V, Gibson DT. Isolation and characterization of Pseudomonas putida PpF1 mutants defective in the toluene dioxygenase enzyme system. J Bacteriol 1984; 160:1003-9. [PMID: 6501223 PMCID: PMC215809 DOI: 10.1128/jb.160.3.1003-1009.1984] [Citation(s) in RCA: 81] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Pseudomonas putida PpF1 degraded toluene via a dihydrodiol pathway to tricarboxylic acid cycle intermediates. The initial reaction was catalyzed by a multicomponent enzyme, toluene dioxygenase, which oxidized toluene to (+)-cis-1(S),2(R)-dihydroxy-3-methylcyclohexa-3,5-diene (cis-toluene dihydrodiol). The enzyme consisted of three protein components: NADH-ferredoxintol oxidoreductase (reductasetol), ferredoxintol, and a terminal oxygenase which is an iron-sulfur protein (ISPtol). Mutants blocked in each of these components were isolated after mutagenesis with nitrosoguanidine. Mutants occurred as colony morphology variants when grown in the presence of toluene on indicator plates containing agar, mineral salts, a growth-supporting nutrient (arginine), 2,3,5-triphenyltetrazolium chloride (TTC), and Nitro Blue Tetrazolium (NBT). Under these conditions, wild-type colonies appeared large and red as a result of TTC reduction. Colonies of reductasetol mutants were white or white with a light blue center, ferredoxintol strains were light blue with a dark blue center, and strains that lacked ISPtol gave dark blue colonies. Blue color differences in the mutant colonies were due to variations in the extent of NBT reduction. Strains lacking all three components appeared white. Toluene dioxygenase mutants were characterized by assaying toluene dioxygenase activity in crude cell extracts which were complemented with purified preparations of each protein component. Between 40 and 60% of the putative mutants selected from the NBT-TTC indicator plates were unable to grow with toluene as the sole source of carbon and energy. This method should prove extremely useful in isolating mutants in other multicomponent oxygenase enzyme systems.
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Subramanian V, Vaidyanathan CS. Anthranilate hydroxylase from Aspergillus niger: new type of NADPH-linked nonheme iron monooxygenase. J Bacteriol 1984; 160:651-5. [PMID: 6501219 PMCID: PMC214784 DOI: 10.1128/jb.160.2.651-655.1984] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Anthranilate hydroxylase from Aspergillus niger catalyzes the oxidative deamination and dihydroxylation of anthranilic acid to 2,3-dihydroxybenzoic acid. This enzyme has been purified to homogeneity and has a molecular weight of 89,000. The enzyme is composed of two subunits of 42,000 with 2 gram-atoms of nonheme iron per mol. Fe2+-chelators like alpha,alpha'-dipyridyl and o-phenanthroline are potent inhibitors of the enzyme activity. Absorption and fluorescence spectra of the enzyme offer no evidence for the presence of other cofactors like flavin. Flavins and flavin-specific inhibitors like atebrin have no effect on the activity of the enzyme. The enzyme incorporates one atom of oxygen each from 18O2 and H218O into the product 2,3-dihydroxybenzoic acid. Based on these studies, it is concluded that anthranilate hydroxylase from A. niger is a new type of NADPH-linked nonheme iron monooxygenase.
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Srivatsa AN, Subramanian V, Sharma TR. Packaging Problems-Present and Future of Service Rations. DEFENCE SCI J 1984. [DOI: 10.14429/dsj.34.6067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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293
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Weksler BB, Pett SB, Alonso D, Richter RC, Stelzer P, Subramanian V, Tack-Goldman K, Gay WA. Differential inhibition by aspirin of vascular and platelet prostaglandin synthesis in atherosclerotic patients. N Engl J Med 1983; 308:800-5. [PMID: 6339916 DOI: 10.1056/nejm198304073081402] [Citation(s) in RCA: 370] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
We studied the ability of a single oral dose of aspirin to inhibit prostacyclin synthesis by human arterial and venous tissue and to inhibit thromboxane A2 synthesis by platelets in 70 patients who were undergoing aortocoronary bypass. A dose of 40, 80, or 325 mg of aspirin was administered 12 to 16 hours before surgery. The generation of thromboxane in serum--which provides an estimate of platelet thromboxane production--was reduced from the control value by 77, 95, and 99 per cent after single doses of 40, 80, and 325 mg of aspirin, respectively. By contrast, prostacyclin production in aortic tissue that was removed at operation was reduced by only 35, 38, and 75 per cent, respectively, in response to these doses. Production of prostacyclin in saphenous-vein tissue (not tested after 40 mg of aspirin) fell only slightly and not significantly after 80 mg but was reduced by 85 per cent after 325 mg. These findings indicate that a low dose of aspirin (40 to 80 mg) can largely inhibit platelet aggregation and thromboxane synthesis but has much less effect on prostacyclin production in arterial and venous endothelium.
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Subramanian V, Hall SR. Normalized structure factors. I. Choice of scaling function. ACTA ACUST UNITED AC 1982. [DOI: 10.1107/s0567739482001235] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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296
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Hall SR, Subramanian V. Normalized structure factors. II. Estimating a reliable value ofB. ACTA ACUST UNITED AC 1982. [DOI: 10.1107/s0567739482001247] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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297
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Hochreiter C, Goldstein J, Borer JS, Tyberg T, Goldberg HL, Subramanian V, Rosenfeld I. Myocardial free-wall rupture after acute infarction: survival aided by percutaneous intraaortic balloon counterpulsation. Circulation 1982; 65:1279-82. [PMID: 7074787 DOI: 10.1161/01.cir.65.6.1279] [Citation(s) in RCA: 33] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
After his first acute myocardial infarction, a 69-year-old male suffered the usually lethal complication of ventricular free-wall rupture. Early suspicion of possible rupture and immediate percutaneous insertion of an intraaortic balloon pump assist device afforded sufficient hemodynamic stability to proceed with cardiac catheterization. The diagnosis of ventricular free-wall rupture was confirmed and the extent of coronary artery disease defined. The patient underwent repair of the free-wall rupture and coronary artery bypass grafting and has returned to full activity.
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Abstract
A percutaneous wire-guided double lumen intraaortic balloon pump was tested in 44 patients, 15 with cardiogenic shock. The balloon volume is 40 ml, the material is Avcothane, and the central lumen will pass a 0.035 inch (0.889 mm) wire guide. Standard Seldinger technique was followed by successful insertion in 40 patients (90 percent) with no recognized vascular trauma. Counterpulsation was excellent and central pressure monitoring through the balloon lumen showed good fidelity. Iliofemoral thrombosis occurred in 5 percent of patients. The overguide technique is simple, successful and atraumatic.
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299
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Hall SR, Subramanian V. The estimation of sigma| E( h)| and its application in phasing procedures. Acta Crystallogr A 1981. [DOI: 10.1107/s0108767381089897] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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300
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Subramanian V, Hall SR. Estimation of reliable normalized structure factors. Acta Crystallogr A 1981. [DOI: 10.1107/s0108767381089903] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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