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Kaur K, Kapur J, Parmar A, Sood ML. Kinetics of antibody response by Dot-ELISA in rabbits immunized with adult Haemonchus contortus antigen. Parasite 2002; 9:363-5. [PMID: 12514952 DOI: 10.1051/parasite/2002094363] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Whole adult soluble extract of Haemonchus contortus as an antigen along with Freund's complete adjuvant, was used to immunize rabbits. Antisera from immunized rabbits were collected at intervals of 30, 60, 90, 120, 150 and 180 days. For the detection and titration of anti-H. contortus antibodies in these sera, Dot-ELISA was developed. Sera collected 30 days post-immunization exhibited a titre of 1:5,000 in all the rabbits except one, where a titre of 20,000 was recorded. Later, all the rabbits attained the highest titre of 40,000 at different periods of post-immunizations, which were maintained 150-180 days. These high titre sera can be of immense use in the identification and characterization of immunodominant antigens of adult H. contortus.
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Kaur K, Arora S, Kumar S, Nagpal A. Antimutagenic activities of acetone and methanol fractions of Terminalia arjuna. Food Chem Toxicol 2002; 40:1475-82. [PMID: 12387312 DOI: 10.1016/s0278-6915(02)00078-9] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The antimutagenic effect of benzene, chloroform, acetone and methanol fractions from Terminalia arjuna, a well-known medicinal plant, was determined against Acid Black dye, 2-aminofluorene (2AF) and 4-nitro-o-phenylenediamine (NPD) in TA98 Frameshift mutagen tester strain of Salmonella typhimurium. Among the different fractions, the antimutagenic effect of acetone and methanol fractions was more than that observed with other fractions. Co-incubation and pre-incubation modes of experimentation did not show much difference in the antimutagenic activity of the extracts. Moreover, these fractions inhibited the S9-dependent mutagens, 2AF and Acid Black dye more effectively than the direct-acting mutagens. Studies are under way to isolate and elucidate the nature of the antimutagenic factor in acetone and methanol fractions.
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Kaur K, Kapur J, Parmar A, Sood ML. Identification of immunodominant antigens of adult Haemonchus contortus (Nematoda: Trichostrongylidae). JOURNAL OF VETERINARY MEDICINE. B, INFECTIOUS DISEASES AND VETERINARY PUBLIC HEALTH 2002; 49:260-2. [PMID: 12121049 DOI: 10.1046/j.1439-0450.2002.00542.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Kaur S, Arora S, Kaur K, Kumar S. The in vitro antimutagenic activity of Triphala--an Indian herbal drug. Food Chem Toxicol 2002; 40:527-34. [PMID: 11893411 DOI: 10.1016/s0278-6915(01)00101-6] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
A study to evaluate an antimutagenic potential of water, chloroform and acetone extracts of Triphala has been made in an Ames histidine reversion assay using TA98 and TA100 tester strains of Salmonella typhimurium against the direct-acting mutagens, 4-nitro-o-phenylenediamine (NPD) and sodium azide, and the indirect-acting promutagen, 2-aminofluorene (2AF), in the presence of phenobarbitone-induced rat hepatic S9. A combination drug 'Triphala' - a composite mixture of Terminalia bellerica, T. chebula and Emblica officinalis, has been used in traditional system of medicine for the treatment of many malaises, such as heart ailments and hepatic diseases. The drug was sequentially extracted with water, acetone and chloroform at room temperature. The study revealed that water extract was ineffective in reducing the revertants induced by the mutagens. The results with chloroform and acetone extracts showed inhibition of mutagenicity induced by both direct and S9-dependent mutagens. A significant inhibition of 98.7% was observed with acetone extract against the revertants induced by S9-dependent mutagen, 2AF, in co-incubation mode of treatment. Various spectroscopic techniques, namely 1H-NMR, normal 13C-NMR, distortionless enhancement by polarization transfer (DEPT-90 and DEPT-135), UV and IR, are under way to identify the polyphenolic compounds from an acetone extract.
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Kaur K, Lan MJ, Pratt RF. Mechanism of inhibition of the class C beta-lactamase of Enterobacter cloacae P99 by cyclic acyl phosph(on)ates: rescue by return. J Am Chem Soc 2001; 123:10436-43. [PMID: 11673973 DOI: 10.1021/ja011094v] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
As previously described (Pratt, R. F.; Hammar, N. J. J. Am. Chem. Soc. 1998, 120, 3004.), 1-hydroxy-4,5-benzo-2,6-dioxaphosphorinone(3)-1-oxide (salicyloyl cyclic phosphate) inactivates the class C beta-lactamase of Enterobacter cloacae P99 in a covalent fashion. The inactivated enzyme slowly reverts to the active form. This paper shows that reactivation involves a recyclization reaction that regenerates salicyloyl cyclic phosphate rather than hydrolysis of the covalent intermediate. The inactivation, therefore, is a slowly reversible covalent modification of the active site. The thermodynamic dissociation constant of the inhibitor from the inactivated enzyme is 0.16 microM. Treatment of the inactivated enzyme with alkali does not produce salicylic acid but does, after subsequent acid hydrolysis, yield one molar equivalent of lysinoalanine. This result proves that salicyloyl cyclic phosphate inactivates the enzyme by (slowly reversible) phosphorylation of the active site serine residue. This result contrasts sharply with the behavior of acyclic acyl phosphates which transiently inactivate the P99 beta-lactamase by acylation (Li, N.; Pratt, R. F. J. Am. Chem. Soc. 1998, 120, 4264.). This chemoselectivity difference is explored by means of molecular modeling. Rather counterintuitively, in view of the relative susceptibility of phosphates and phosphonates to nucleophilic attack at phosphorus, 1-hydroxy-4,5-benzo-2-oxaphosphorinanone(3)-1-oxide, the phosphonate analogue of salicyloyl cyclic phosphate, did not appear to inactivate the P99 beta-lactamase in a time-dependent fashion. It was found, however, to act as a fast reversible inhibitor (K(i) = 10 microM). A closer examination of the kinetics of inhibition revealed that both on and off rates (9.8 x 10(3) s(-1) x M(-1) and 0.098 s(-1), respectively) were much slower than expected for noncovalent binding. This result strongly indicates that the inhibition reaction of the phosphonate also involves phosphylation of the active site. Hence, unlike the situation with bacterial DD-peptidases covalently inactivated by beta-lactams, the P99 beta-lactamase inactivated by the above cyclic acyl phosph(on)ates can be rescued by return. Elimination of the recyclization reaction would lead to more effective inhibitors.
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Kaur K, Pratt RF. Mechanism of reaction of acyl phosph(on)ates with the beta-lactamase of Enterobacter cloacae P99. Biochemistry 2001; 40:4610-21. [PMID: 11294628 DOI: 10.1021/bi002243+] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A series of acyl phosph(on)ates has been prepared to more closely examine the details of the interactions of this class of molecule with beta-lactamases. In general, they were found to react with the class C beta-lactamase of Enterobacter cloacae P99 in two ways, by acylation and by phosphylation. The acyl-enzymes generated by the former reaction were transiently stable with half-lives of between 3 and 45 s, of comparable lifetime therefore to those generated by the inhibitory beta-lactams cefotaxime, cefuroxime, and cefoxitin. On the other hand, phosphylation led to a completely inactive enzyme. In general, the second-order rate constants for acylation (k(cat)/K(m)) were larger than for phosphylation (k(i)). As expected on chemical grounds, phosphylation was found to be relatively more effective for the phosphonates than the phosphates. The acyl phosphates were much more effective acylating agents however. The acylation reaction was found to be enhanced by hydrophobic substituents in both the acyl and leaving group moieties. Thus, the most reactive compound in this series was benzo[b]thiophene-2-carbonyl 2'-naphthyl phosphate with a K(m) value of 0.15 microM and a k(cat) of 0.2 s(-1); k(cat)/K(m) is therefore 1.3 x 10(6) s(-1) M(-1), making this compound the most specific acyclic acylation reagent for this beta-lactamase yet described. Significant substrate inhibition by this compound suggested that further binding regions may be available for exploitation in inhibitor design. A linear free energy analysis showed that the transition states for acylation of the beta-lactamase by aroyl phosphates are analogues of the corresponding aryl boronic acid adducts. Molecular modeling suggested that the aroyl phosphates react with the P99 beta-lactamase with the aroyl group in the side chain/acyl group site of normal substrates and the phosphate in the leaving group site. In this orientation, the phosphate leaving group interacts strongly with Lys 315.
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Phipps RP, Pollock SJ, Kaur K, Kaufman J, Borrello MA, Graf BA, Nazarenko D, Roberts LJ, Morrow JD, Palis J, Ryan DJ, Bennett JM. Expression of cyclooxygenase-2 and prostaglandins by B-1 cells and B-CLL cells. Curr Top Microbiol Immunol 2001; 252:293-300. [PMID: 11187084 DOI: 10.1007/978-3-642-57284-5_30] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
MESH Headings
- Animals
- Antibodies, Anti-Idiotypic/pharmacology
- B-Lymphocyte Subsets/enzymology
- B-Lymphocyte Subsets/metabolism
- B-Lymphocyte Subsets/pathology
- CD40 Ligand/immunology
- Cell Differentiation
- Cyclooxygenase 1
- Cyclooxygenase 2
- Dinoprostone/biosynthesis
- Dinoprostone/genetics
- Enzyme Induction
- Gene Expression Regulation, Leukemic
- Humans
- Inflammation/enzymology
- Inflammation/metabolism
- Inflammation/pathology
- Interferon-gamma/pharmacology
- Isoenzymes/biosynthesis
- Isoenzymes/genetics
- Leukemia, Lymphocytic, Chronic, B-Cell/enzymology
- Leukemia, Lymphocytic, Chronic, B-Cell/metabolism
- Leukemia, Lymphocytic, Chronic, B-Cell/pathology
- Lipopolysaccharides/pharmacology
- Lymphocyte Activation/drug effects
- Macrophages/immunology
- Macrophages/pathology
- Membrane Proteins
- Mice
- Neoplasm Proteins/biosynthesis
- Neoplasm Proteins/genetics
- Neoplastic Stem Cells/enzymology
- Neoplastic Stem Cells/metabolism
- Prostaglandin-Endoperoxide Synthases/biosynthesis
- Prostaglandin-Endoperoxide Synthases/genetics
- Prostaglandins/biosynthesis
- Prostaglandins/genetics
- RNA, Messenger/biosynthesis
- Th2 Cells/immunology
- Tumor Cells, Cultured/metabolism
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Sidhu PK, Kaur K, Kumar I, Lata S. Glucose-6-phosphate dehydrogenase deficiency in blood donors: screening by micromethaemoglobin reduction test. INDIAN J PATHOL MICR 2001; 44:23-5. [PMID: 12561990] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/28/2023] Open
Abstract
500 blood donors were screened for G6PD deeiciency using micromethaemoglobin reduction (microMRT) test. Most of the blood donors were young adult males (95.8%). The overall incidence of G6PD deficiency was found to be 0.8%. There, was apparently decreased frequency of G6PD deficient blood donors with increasing age, and no relation could be ascertained between G6PD) deficiency and blood groups.
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Padilla J, Kaur K, Cao HJ, Smith TJ, Phipps RP. Peroxisome proliferator activator receptor-gamma agonists and 15-deoxy-Delta(12,14)(12,14)-PGJ(2) induce apoptosis in normal and malignant B-lineage cells. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2000; 165:6941-8. [PMID: 11120820 DOI: 10.4049/jimmunol.165.12.6941] [Citation(s) in RCA: 124] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The research described herein evaluates the expression and functional significance of peroxisome proliferator activator receptor-gamma (PPAR-gamma) on B-lineage cells. Normal mouse B cells and a variety of B lymphoma cells reflective of stages of B cell differentiation (e.g., 70Z/3, CH31, WEHI-231, CH12, and J558) express PPAR-gamma mRNA and, by Western blot analysis, the 67-kDa PPAR-gamma protein. 15-Deoxy-Delta(12,14)-PGJ(2) (15d-PGJ(2)), a PPAR-gamma agonist, has a dose-dependent antiproliferative and cytotoxic effect on normal and malignant B cells as shown by [(3)H]thymidine and 3-[4,5-dimethylthiazol-2-yl]-2, 5-diphenyltetrazolium bromide assays. Only PPAR-gamma agonists (thiazolidinediones), and not PPAR-alpha agonists, mimicked the effect of 15d-PGJ(2) on B-lineage cells, indicating that the mechanism by which 15d-PGJ(2) negatively affects B-lineage cells involves in part PPAR-gamma. The mechanism by which PPAR-gamma agonists induce cytotoxicity is via apoptosis, as shown by annexin V staining and as confirmed by DNA fragmentation detected using the TUNEL assay. Interestingly, addition of PGF(2alpha), which was not known to affect lymphocytes, dramatically attenuated the deleterious effects of PPAR-gamma agonists on B lymphomas. Surprisingly, 15d-PGJ(2) induced a massive increase in nuclear mitogen-activated protein kinase activation, and pretreatment with PGF(2alpha) blunted the mitogen-activated protein kinase activation. This is the first study evaluating PPAR-gamma expression and its significance on B lymphocytes. PPAR-gamma agonists may serve as a counterbalance to the stimulating effects of other PGs, namely PGE(2), which promotes B cell differentiation. Finally, the use of PGs, such as 15d-PGJ(2), and synthetic PPAR-gamma agonists to induce apoptosis in B-lineage cells may lead to the development of novel therapies for fatal B lymphomas.
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MESH Headings
- Animals
- Apoptosis/drug effects
- Apoptosis/immunology
- B-Lymphocytes/cytology
- B-Lymphocytes/drug effects
- B-Lymphocytes/metabolism
- Cell Lineage/immunology
- Cells, Cultured
- Chromans/pharmacology
- Dinoprost/pharmacology
- Hypoglycemic Agents/pharmacology
- Lymphoma, B-Cell/metabolism
- Lymphoma, B-Cell/pathology
- Male
- Mice
- Mice, Inbred C3H
- Mice, Inbred C57BL
- Mice, Inbred DBA
- Prostaglandin D2/analogs & derivatives
- Prostaglandin D2/physiology
- Prostaglandin D2/toxicity
- RNA, Messenger/biosynthesis
- Receptors, Cytoplasmic and Nuclear/agonists
- Receptors, Cytoplasmic and Nuclear/biosynthesis
- Receptors, Cytoplasmic and Nuclear/genetics
- Receptors, Cytoplasmic and Nuclear/physiology
- Thiazoles/pharmacology
- Thiazolidinediones
- Transcription Factors/agonists
- Transcription Factors/biosynthesis
- Transcription Factors/genetics
- Transcription Factors/physiology
- Troglitazone
- Tumor Cells, Cultured
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Kaur R, Kaur K. Effects of dietary selenium (SE) on morphology of testis and cauda epididymis in rats. INDIAN JOURNAL OF PHYSIOLOGY AND PHARMACOLOGY 2000; 44:265-72. [PMID: 10941613] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
Selenium is an essential micronutrient for animals. To determine whether its excess in diet induces morphological changes within the male reproductive system, a detailed qualitative and quantitative evaluation of the changes in the histology of the testis and cauda epididymis was undertaken in male rats. Adult male albino rats were fed 6 and 8 ppm Se in diet for 6 and 9 weeks. Each male consuming 6 ppm Se was mated with two untreated females, their offsprings were allowed to mature upto 12 weeks of age. The testes and cauda epididymes of male rats were prepared for light microscopy. Excess of dietary Se caused dose-time-dependent reduction in body weight and reproductive organ weights but increase in number of morphologically abnormal spermatozoa. Histopathological studies of the testes and cauda epididymis have revealed that Se-rich diets cause dose-time-dependent reduction in tubular diameter, epithelial height, number of spermatogenic cells and disintegration of cellular associations in the seminiferous tubules of testes along with reduction in the diameter of cauda epididymal tubules and pseudostratification of their epithelial lining. Progeny (feeding on normal diet) of paternally treated rats has shown retarded growth.
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Salomon RG, Kaur K, Podrez E, Hoff HF, Krushinsky AV, Sayre LM. HNE-derived 2-pentylpyrroles are generated during oxidation of LDL, are more prevalent in blood plasma from patients with renal disease or atherosclerosis, and are present in atherosclerotic plaques. Chem Res Toxicol 2000; 13:557-64. [PMID: 10898587 DOI: 10.1021/tx000007u] [Citation(s) in RCA: 84] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Free radical oxidation of human plasma low-density lipoprotein (LDL) produces 2-pentylpyrrole epitopes that are generated by reaction of 4-hydroxy-2-nonenal (HNE), a product of lipid oxidation, with protein lysyl residues. The HNE-derived 2-pentylpyrrole ("HNE-pyrrole") epitopes were detected with an enzyme-linked immunosorbent assay (ELISA) using antibodies (ON-KLH) raised against protein-bound 2-pentylpyrrole obtained by the reaction of 2-oxononanal (ON) with keyhole limpet hemocyanin (KLH). HNE-pyrrole epitopes in human plasma are not associated primarily with LDL protein, apolipoprotein (apo) B, since only 15% of the total HNE-pyrrole immunoreactivity is removed by immunoprecipitation of apo B. The levels of ON-KLH immunoreactivity detected in human plasma were found to be significantly elevated in renal failure and atherosclerosis patients when compared to those in healthy volunteers. HNE-pyrrole immunoreactivity was also detected in atherosclerotic plaques. The highest levels were associated with extracellular connective tissue. Levels of ON-KLH immunoreactivity in human plasma far exceed levels of free HNE, presumably because of the rapid clearance of free relative to protein-bound HNE. Therefore, HNE-pyrrole epitopes provide a more indelible marker of oxidative injury than levels of free HNE.
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Salomon RG, Batyreva E, Kaur K, Sprecher DL, Schreiber MJ, Crabb JW, Penn MS, DiCorletoe AM, Hazen SL, Podrez EA. Isolevuglandin-protein adducts in humans: products of free radical-induced lipid oxidation through the isoprostane pathway. BIOCHIMICA ET BIOPHYSICA ACTA 2000; 1485:225-35. [PMID: 10832102 DOI: 10.1016/s1388-1981(00)00038-x] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
A family of extremely reactive electrophiles, isolevuglandins (isoLGs), is generated in vivo by free radical-induced lipid oxidation and rearrangement of endoperoxide intermediates of the isoprostane pathway. Protein adducts of two different oxidized lipids, isoLGE(2) and iso[4]LGE(2), and the corresponding autoantibodies are present in human blood. Western blot analysis of a polyacrylamide gel electrophoresis gel detects several immunoreactive plasma proteins. Only a minor fraction of the isoLG-protein modifications is associated with low density lipoprotein since mean levels were decreased only 20-22% by immunoprecipitation of apolipoprotein B (apoB). Mean levels of both isoLGE(2) and iso[4]LGE(2)-protein adducts in plasma from patients with atherosclerosis (AS) (n=16) or end-stage renal disease (RD) (n=8) are about twice those in healthy individuals (n=25). These elevated levels are not related to variations in age, total cholesterol or apoB. A linear correlation (r=0.79) between plasma isoLGE(2) and iso[4]LGE(2)-protein adduct levels in all 49 individuals is consistent with a common free radical-induced mechanism for the production of both oxidized lipids in vivo. The correlation is even stronger (r=0.86) for patients with AS or RD. That isoLG-protein adduct levels are more strongly correlated with disease than are total cholesterol or apoB suggests an independent defect that results in an abnormally high level of oxidative injury associated with AS and RD.
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89
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Jain D, Kaur K, Sundaravadivel B, Salunke DM. Structural and functional consequences of peptide-carbohydrate mimicry. Crystal structure of a carbohydrate-mimicking peptide bound to concanavalin A. J Biol Chem 2000; 275:16098-102. [PMID: 10821862 DOI: 10.1074/jbc.275.21.16098] [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: 11/06/2022] Open
Abstract
The functional consequences of peptide-carbohydrate mimicry were analyzed on the basis of the crystal structure of concanavalin A (ConA) in complex with a carbohydrate-mimicking peptide, DVFYPYPYASGS. The peptide binds to the non-crystallographically related monomers of two independent dimers of ConA in two different modes, in slightly different conformations, demonstrating structural adaptability in ConA-peptide recognition. In one mode, the peptide has maximum interactions with ConA, and in the other, it shows relatively fewer contacts within this site but significant contacts with the symmetry-related subunit. Neither of the peptide binding sites overlaps with the structurally characterized mannose and trimannose binding sites on ConA. Despite this, the functional mimicry between the peptide and carbohydrate ligands was evident. The peptide-inhibited ConA induced T cell proliferation in a dose-dependent manner. The effect of the designed analogs of the peptide on ConA-induced T cell proliferation and their recognition by the antibody response against alpha-d-mannopyranoside indicate a role for aromatic residues in functional mimicry. Although the functional mimicry was observed between the peptide and carbohydrate moieties, the crystal structure of the ConA-peptide complex revealed that the two peptide binding sites are independent of the methyl alpha-d-mannopyranoside binding site.
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90
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Padilla J, Kaur K, Harris SG, Phipps RP. PPAR-gamma-mediated regulation of normal and malignant B lineage cells. Ann N Y Acad Sci 2000; 905:97-109. [PMID: 10818446 DOI: 10.1111/j.1749-6632.2000.tb06542.x] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Prostaglandins of the E-series stimulate B lymphocytes by enhancing immunoglobulin-class switching and antibody production. Little is known about whether or not other prostaglandins affect B lineage cells and perhaps counterbalance the stimulatory effects of PGE2. PGD2 is a major product of cyclooxygenase in bone marrow and in macrophages, suggesting a role for this lipid product in immunological responses. PGD2 undergoes dehydration to the biologically active prostaglandin 15-deoxy-delta 12,14-PGJ2 (15d-PGJ2) that binds to the nuclear receptor known as peroxisome proliferator-activated receptor gamma (PPAR-gamma). We found that normal mouse B cells and a variety of B lymphoma cells (e.g., 70Z/3, WEHI-231, CH12, and J558) express PPAR-gamma mRNA and the 67-kDa PPAR-gamma protein. 15d-PGJ2 had a dose-dependent antiproliferative/cytotoxic effect on normal and malignant B cells, as shown by 3H-thymidine and MTT assays. Only PPAR-gamma agonists (i.e., thiazolidinediones) mimicked the effect of 15d-PGJ2 on B lineage cells, indicating that the mechanism by which 15d-PGJ2 negatively affects B lineage cells involves PPAR-gamma. The mechanism whereby PPAR-gamma agonists induced cytotoxicity is via apoptosis, as shown by Annexin V assay. PPAR-gamma agonists may serve as a counterbalance to the stimulating effects of PGE2, which promotes B-cell differentiation. The use of prostaglandins, such as 15d-PGJ2, and synthetic PPAR-gamma agonists to induce apoptosis in B lineage cells may lead to the development of therapies for fatal PGE2-resistant B lymphomas.
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92
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Kaur K, Harris SG, Padilla J, Graf BA, Phipps RP. Prostaglandin E2 as a modulator of lymphocyte mediated inflammatory and humoral responses. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2000; 469:409-12. [PMID: 10667360 DOI: 10.1007/978-1-4615-4793-8_59] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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93
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Salomon RG, Kaur K, Batyreva E. Isolevuglandin-protein adducts in oxidized low density lipoprotein and human plasma: a strong connection with cardiovascular disease. Trends Cardiovasc Med 2000; 10:53-9. [PMID: 11150730 DOI: 10.1016/s1050-1738(00)00040-2] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Isolevuglandins (isoLGs) are extremely reactive gamma-ketoaldehydes that avidly bind covalently with proteins and cause protein-protein as well as DNA-protein crosslinking. IsoLG-protein adducts are generated upon oxidation of low-density lipoprotein (LDL), and may contribute to atherogenesis since such adducts cause recognition and endocytosis of the modified LDL by macrophage cells. Levels of isoLG-protein adducts in human blood plasma are more closely correlated with disease than are the classical risk factors LDL or total cholesterol. We review the basic research that eventuated in the discovery of isoLGs and describe what is known about their natural occurrence and close connection with cardiovascular disease.
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94
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95
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Kaur K, Singh M. Role of prolactin in human reproduction. Int J Gynaecol Obstet 2000. [DOI: 10.1016/s0020-7292(00)81445-9] [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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96
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Klinge CM, Kaur K, Swanson HI. The aryl hydrocarbon receptor interacts with estrogen receptor alpha and orphan receptors COUP-TFI and ERRalpha1. Arch Biochem Biophys 2000; 373:163-74. [PMID: 10620335 DOI: 10.1006/abbi.1999.1552] [Citation(s) in RCA: 102] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The molecular mechanisms underlying the apparent "cross-talk" between estrogen receptor (ER)- and arylhydrocarbon receptor (AHR)-mediated activities are unknown. To determine how AHR ligand 2, 3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) may inhibit ER action and, conversely, to examine how 17-beta-estradiol (E(2)) affects AHR activity, we examined discrete activities of each receptor, i.e., protein-protein interactions, DNA binding, and transcriptional activation. We report that AHR interacts directly with ERalpha, COUP-TF, and ERRalpha1, in a ligand-specific manner in vitro. Unoccupied or beta-napthoflavone (beta-NF)-occupied AHR showed stronger interaction with ERalpha, COUP-TF, and ERRalpha1 than when AHR was occupied by the partial antagonist alpha-naphthoflavone (alpha-NF), indicating a role for ligand in AHR interaction with these proteins. We also report that AHR interacts with COUP-TF in transfected CV-1 cells. In contrast, the AHR nuclear translocator protein (ARNT) did not interact with COUP-TF, ERRalpha1, or ERalpha. We next examined the interaction of either ERalpha or COUP-TF with a consensus xenobiotic response element (XRE). Purified ERalpha did not bind the consensus XRE, but COUP-TFI bound the consensus XRE, suggesting a role for COUP-TF as a AHR/ARNT competitor for XRE binding. In transiently transfected MCF-7 human breast cancer cells, overexpression of COUP-TFI inhibited TCDD-activated reporter gene activity from the CYP1A1 promoter. TCDD inhibited estradiol (E(2))-activated reporter gene activity from a consensus ERE and from the EREs in the pS2 and Fos genes, and COUP-TFI did not block the antiestrogenic activity of TCDD. The specific interaction of COUP-TF with XREs and AHR together with the inhibition of TCDD-induced gene expression by COUP-TF suggests that COUP-TF may regulate AHR action both by direct DNA binding competition and through protein-protein interactions.
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McCarren M, Zalenski RJ, McDermott M, Kaur K. Predicting recovery from acute asthma in an emergency diagnostic and treatment unit. Acad Emerg Med 2000; 7:28-35. [PMID: 10894239 DOI: 10.1111/j.1553-2712.2000.tb01887.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
OBJECTIVE Optimal use of emergency diagnostic and treatment unit (EDTU) resources for treatment of acute asthma should be facilitated by the selection of patients with a high probability of discharge from the EDTU. The study goal was to identify characteristics of the patient or exacerbation that could be used to predict recovery of pulmonary function within 12 hours. METHODS Comprehensive cohort design in an urban public hospital. The subjects were 269 patients with moderately severe asthma exacerbations. Data were collected for historical and presenting features and response to treatment over 12 hours. Two outcomes were examined: 1) discharge from the EDTU and 2) achieving 50% predicted peak expiratory flow rate (PEFR) within 12 hours. RESULTS The two outcomes showed good concordance. The third-treatment PEFR was found to be predictive of both discharge and reaching 50% predicted PEFR within 12 hours. Since the objective measure of reaching 50% predicted PEFR is more readily defined and thus more generalizable, the authors focused on this outcome when describing prediction zones. Patients with 40% or higher PEFR after third treatment had an 89% probability of reaching 50% predicted in 12 hours, while those with a third-treatment PEFR lower than 32% predicted had only a 22% probability. CONCLUSIONS A simple objective measure of pulmonary function early in treatment discriminated among those with high, low, and intermediate probabilities of achieving a specified level of PEFR within 12 hours. Awareness of this probability could assist clinicians attempting to predict discharge from the EDTU and facilitate decision making regarding utilization of EDTU resources.
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Sengwa RJ, Kaur K. Microwave absorption in oligomers of ethylene glycol. INDIAN JOURNAL OF BIOCHEMISTRY & BIOPHYSICS 1999; 36:325-9. [PMID: 10844983] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
The dielectric properties of biologically and pharmaceutically important low-molecular weight ethylene glycols H(-OCH2CH2-)n -OH (n = 1,2,4,6) were investigated to clarify the effect of chain length on the dielectric properties. The measurement of dielectric constant and dielectric loss was carried out over the frequency range 200 MHz to 20 GHz at temperatures of 25 degrees C to 55 degrees C. It is found that in these molecules microwave dielectric losses are significant. The dispersion behaviour of these molecules can be represented by Cole-Cole equation. The dielectric properties of these homologous ethylene glycols are discussed in terms of the effects of chain length and intermolecular hydrogen bonds regarding the molecular conformations. These wide frequency range dielectric data have also been discussed in view of the suitable selection of the oligomer of ethylene glycol for cosmetic preparations and other pharmaceutical applications with the intention of protection of the skin from weak microwave radiations present in the surrounding environment. These systematic microwave dielectric data with frequency and temperature variation are not available and are provided in this paper.
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Virk S, Kaur K. Impact of mixture of nickel and chromium on the protein content of flesh and liver of Cyprinus carpio during spawning and post-spawning phases. BULLETIN OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 1999; 63:499-502. [PMID: 10501728 DOI: 10.1007/s001289901008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Cooksey JA, Kaur K, Matters MD, Simone B, Chun E, Hoekstra A. Community health centers: unrecognized partners in health professions education. J Health Care Poor Underserved 1999; 10:349-61. [PMID: 10436733 DOI: 10.1353/hpu.2010.0551] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Increasing demand for health professionals with training in ambulatory and primary care practice is placing stress on existing training site capacity. Community health centers can serve as model training sites, offering comprehensive multidisciplinary health care services and teaching clinician role models. In this study, 32 Illinois community and migrant health centers and federally qualified health centers were surveyed to asses their involvement with training in the past three years. Thirty centers had offered training to students from many disciplines, with nursing (27 centers) and medicine (24) the most frequent. Most centers had established formal relationships with training institutions but generally had limited involvement with course planning. Continued participation will likely require adequate funding, with some centers also seeking stronger institutional relationships and better integration of community health issues. Educators and policy makers may need to take a more active role in supporting centers, acquiring funds, and other enabling factors.
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