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Ling X, Lindsay BG, Smith KA, Dunning FB. Rydberg-atom collisions with SF6 and CCl4 at very high n. PHYSICAL REVIEW. A, ATOMIC, MOLECULAR, AND OPTICAL PHYSICS 1992; 45:242-246. [PMID: 9906719 DOI: 10.1103/physreva.45.242] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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177
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Popple RA, Durham MA, Marawar RW, Lindsay BG, Smith KA, Dunning FB. Velocity dependence of free-ion production in K(np)-SF6 collisions: Internal-to-translational energy transfer. PHYSICAL REVIEW. A, ATOMIC, MOLECULAR, AND OPTICAL PHYSICS 1992; 45:247-251. [PMID: 9906720 DOI: 10.1103/physreva.45.247] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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178
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Smith EW, Smith KA, Maibach HI, Andersson PO, Cleary G, Wilson D. The local side effects of transdermally absorbed nicotine. SKIN PHARMACOLOGY : THE OFFICIAL JOURNAL OF THE SKIN PHARMACOLOGY SOCIETY 1992; 5:69-76. [PMID: 1637561 DOI: 10.1159/000211021] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Percutaneous nicotine administration induces predominant sudorific and rubiform responses in the skin which may be accompanied by subtle piloerection, hyperalgesia and pruritus (although these signs are not overtly manifest). These dermal responses are complex and mechanisms have been proposed for the direct nicotine-stimulation of sweat glands, piloerection and vasoconstriction. These reactions are accompanied by secondary activation and release of vasodilator peptides which produce a predominating vasodilator tone following topical administration, this response masking the direct axon reflex-mediated vasoconstriction.
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179
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Watts ME, Murray JC, Smith KA, Woodcock M. Flavone acetic acid as a modifier of endothelial cell function. Int J Radiat Oncol Biol Phys 1992; 22:431-5. [PMID: 1735673 DOI: 10.1016/0360-3016(92)90847-b] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Flavone acetic acid (FAA) causes significant regression of larger established tumors in murine systems in vivo, but is only slightly toxic in vitro. This in vivo effect is thought to be indirect, or immunological, rather than a direct cytotoxic effect on tumor cells. Using the WHFIB fibrosarcoma, which grows both in vivo and in vitro, and the murine endothelial cell line B10, we have studied the effect of FAA on the survival of tumor and endothelial cells in vitro. The times taken for 1 mg ml-1 FAA to reduce survival to 0.1 surviving fraction were 63 hr for B10 and greater than 85 hr for WHFIB in vitro. WHFIB tumors in vivo were more sensitive than tumor cells in vitro, a single dose of 150 mg kg-1 FAA inducing a tumor growth delay of 10 days at treatment size + 2 mm. As FAA is more toxic to tumor-bearing animals than to those which are non-tumor bearing the effect of tumor conditioned medium on the cytotoxicity of FAA toward B10 cells was studied; no enhanced effect was seen. As FAA is only weakly cytotoxic in vitro to endothelial cells, and even less so to tumor cells, sublethal effects of FAA on endothelial cell function in vitro were studied. The permeability of monolayers of human unbilical vein endothelial cells (HUVEC) in vitro is transiently increased by FAA. Also, procoagulant activity of HUVEC is induced by FAA and this activity is further enhanced in the presence of a factor isolated from Meth-A tumor cells.
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180
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Afflitto J, Smith KA, Patel M, Esposito A, Jensen E, Gaffar A. 113Cd nuclear magnetic resonance (NMR) study of the inhibitory effect of methylvinylether/maleic acid (PVM/MA) copolymer on the alkaline phosphatase of Escherichia coli. Pharm Res 1991; 8:1384-8. [PMID: 1798674 DOI: 10.1023/a:1015897006182] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The inhibitory effect of PVM/MA copolymer on the alkaline phosphatase (AP) of E. coli was investigated. Kinetic studies indicated that enzyme inhibition was characterized by a reduction in both the Vmax and the Km. Addition of 1 mM zinc or magnesium ions to the reaction prevented inhibition of the enzyme by the copolymer. The inhibitory effect of the copolymer on alkaline phosphatase was also investigated using 113Cd NMR after exchange of the active center metal ions with 113Cd. The resulting Cd(II)6AP exhibited characteristic 113Cd resonances reflecting the environment of the A, B, and C metal binding sites of the enzyme's active center. Addition of copolymer resulted in a 113Cd NMR spectrum which indicated removal of 113Cd from the C site and formation of two distinct forms of the enzyme. Possible explanations for the 113Cd NMR results are discussed.
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181
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Gao RS, Johnson LK, Smith GJ, Hakes CL, Smith KA, Lane NF, Stebbings RF, Kimura M. Collisions between H+ and H2 at kilo-electron-volt energies: Absolute differential cross sections for small-angle direct, single-, and double-charge-transfer scattering. PHYSICAL REVIEW. A, ATOMIC, MOLECULAR, AND OPTICAL PHYSICS 1991; 44:5599-5604. [PMID: 9906617 DOI: 10.1103/physreva.44.5599] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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182
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Smith GJ, Johnson LK, Gao RS, Smith KA, Stebbings RF. Absolute differential cross sections for electron capture and loss by kilo-electron-volt hydrogen atoms. PHYSICAL REVIEW. A, ATOMIC, MOLECULAR, AND OPTICAL PHYSICS 1991; 44:5647-5652. [PMID: 9906625 DOI: 10.1103/physreva.44.5647] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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183
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Thurston G, Smith KA, Murray JC. Anticoagulant treatment does not affect the action of flavone acetic acid in tumour-bearing mice. Br J Cancer 1991; 64:689-92. [PMID: 1911218 PMCID: PMC1977683 DOI: 10.1038/bjc.1991.382] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Flavone acetic acid (FAA) is a novel antitumour agent that has a profound effect on the vasculature in murine tumour models. Previously we have shown that FAA induces a coagulopathy and thrombocytopaenia in tumour-bearing mice, and the purpose of the present study was to determine the significance of the FAA-induced intravascular coagulation in the antitumour action of FAA. Several anticoagulant agents were tested for their effectiveness in altering ex vivo coagulation of murine plasma; heparin and ancrod were found to be most effective. These agents were administered to tumour-bearing mice prior to FAA and TNF treatment with little effect on the induced regrowth delay. However: the FAA-induced consumption of platelets in tumour-bearing mice was not blocked by anticoagulant treatment. These data suggest that platelet consumption occurs independently of the normal coagulation pathway, and further that fibrin deposition may not be a major factor in the antitumour action of FAA.
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184
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Smith KA, Frank E. Stereotaxic placement of a ventricular catheter and reservoir for the administration of morphine sulfate. AXONE (DARTMOUTH, N.S.) 1991; 13:12-5. [PMID: 1888669] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Patients with intractable pain due to cancer present a unique challenge to both medical and nursing personnel. This case study illustrates a unique home hospice managed pain control regime that has been implemented for a terminal cancer patient with intractable pain. A ventricular catheter attached to a reservoir was stereotaxically implanted for the administration of preservative-free morphine sulfate. The presentation will include the history of intraspinal morphine, the surgical placement of the ventricular access devise, and the procedure for intraventricular morphine administration. Also, the preoperative nursing assessment and patient family education will be discussed. Education of hospice nurses in the technique of injection, postoperative pain assessment, monitoring of side effects and discharge planning will conclude the presentation.
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185
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Smith KA, Thurston G, Murray JC. Systemic effects of FAA are enhanced by implanted tumours. Int J Radiat Biol 1991; 60:389-93. [PMID: 1678000 DOI: 10.1080/09553009114552211] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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186
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Smith KA. Documentation of blood for transfusion. J ROY ARMY MED CORPS 1991; 137:107-8. [PMID: 1908519] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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187
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Murray JC, Smith KA, Stern DM. Flavone acetic acid potentiates the induction of endothelial procoagulant activity by tumour necrosis factor. Eur J Cancer 1991; 27:765-70. [PMID: 1829921 DOI: 10.1016/0277-5379(91)90185-g] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Treatment of human umbilical vein endothelial cells with flavone acetic acid (FAA) at 800 micrograms/ml for 4 h resulted in a 3-11-fold increase in procoagulant activity. This increase was due to enhanced tissue factor expression on the endothelial cell surface, as evidenced by the blocking of the enhanced clotting with antibody to tissue factor, by substitution of normal with factor VII deficient plasma, or by simultaneous treatment of the endothelial cells with cycloheximide or actinomycin D. FAA was not toxic to endothelial cell at concentrations up to 1.6 mg/ml over 4 h. Combined treatment with FAA and tumour necrosis factor alpha (TNF-alpha) (100 pg/ml) produced a 675-fold (range 160-1980) increase in tissue factor activity, compared to 5-fold and 50-fold increases for the individual agents respectively. Northern blotting of total RNA from cells treated with the combination of agents or either agent alone, followed by probing with a cDNA to human tissue factor demonstrated a synergistic increase in tissue factor mRNA after combination treatment. In vivo, the combination of FAA and TNF-alpha could be shown to induce greater growth delay in two murine tumours than would be predicted on the basis of the activity of either agent alone.
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188
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Smith KA, Salyers AA. Characterization of a neopullulanase and an alpha-glucosidase from Bacteroides thetaiotaomicron 95-1. J Bacteriol 1991; 173:2962-8. [PMID: 1708385 PMCID: PMC207879 DOI: 10.1128/jb.173.9.2962-2968.1991] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Previously, we constructed a gene disruption in the pullulanase I gene of Bacteroides thetaiotaomicron 5482A. This mutant, designated B. thetaiotaomicron 95-1, had a lower level of pullulanase specific activity than did wild-type B. thetaiotaomicron but still exhibited a substantial amount of pullulanase activity. Characterization of the remaining pullulanase activity present in B. thetaiotaomicron 95-1 has identified an alpha(1----4)-D-glucosidic bond cleaving pullulanase which has been tentatively designated a neopullulanase. The neopullulanase (pullulanase II) is a 70-kDa soluble protein which cleaves alpha(1----4)-D-glucosidic bonds in pullulan to produce panose. The neopullulanase also cleaved alpha(1----4) bonds in amylose and in oligosaccharides of maltotriose through maltoheptaose in chain length. An alpha-glucosidase from B. thetaiotaomicron 95-1 was characterized. The alpha-glucosidase was partially purified to a preparation containing three proteins of 80, 57, and 50 kDa. Pullulan and amylose were not hydrolyzed by the alpha-glucosidase. alpha(1----4)-D-Glucosidic oligosaccharides from maltose to maltoheptaose were hydrolyzed to glucose by the alpha-glucosidase. The alpha-glucosidase also hydrolyzed alpha(1----6)-linked oligosaccharides such as panose (the product of the pullulanase II action on pullulan) and isomaltotriose.
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189
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Zmuidzinas A, Mamon HJ, Roberts TM, Smith KA. Interleukin-2-triggered Raf-1 expression, phosphorylation, and associated kinase activity increase through G1 and S in CD3-stimulated primary human T cells. Mol Cell Biol 1991; 11:2794-803. [PMID: 1708096 PMCID: PMC360057 DOI: 10.1128/mcb.11.5.2794-2803.1991] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
To gain further insight into the role of Raf-1 in normal cell growth, c-raf-1 mRNA expression, Raf-1 protein production, and Raf-1-associated kinase activity in normal human T cells were analyzed. In contrast to the constitutive expression of Raf-1 in continuously proliferating cell lines, c-raf-1 mRNA and Raf-1 protein levels were barely detectable in freshly isolated G0 T lymphocytes. Previous work with fibroblasts has suggested that Raf-1 plays a signaling role in the G0-G1 phase transition. In T cells, triggering via the T-cell antigen receptor (TCR)-CD3 complex (TCR/CD3) resulted in an approximately fourfold increase in c-raf-1 mRNA. In addition, the promotion of G1 progression by interleukin 2 (IL-2) was associated with a 5- to 10-fold immediate/early induction of c-raf-1 mRNA, resulting in up to a 12-fold increase in Raf-1 protein expression. TCR/CD3 activation did not alter the phosphorylation state of Raf-1, whereas interleukin 2 receptor stimulation resulted in a rapid increase in the phosphorylation state of a subpopulation of Raf-1 molecules progressively increasing throughout G1. These findings were complemented by assays for Raf-1-associated kinase activity which revealed a gradual accumulation of serine and threonine autokinase activity in Raf-1 immunoprecipitates during G1, which remained elevated throughout DNA replication.
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MESH Headings
- Antigens, CD/physiology
- Antigens, Differentiation, T-Lymphocyte/physiology
- Blotting, Northern
- Blotting, Western
- CD3 Complex
- Cell Cycle
- Cells, Cultured
- Cycloheximide/pharmacology
- Cyclosporins/pharmacology
- Gene Expression/drug effects
- Humans
- Interleukin-2/pharmacology
- Phosphorylation
- Plasmids
- Protein-Tyrosine Kinases/genetics
- Protein-Tyrosine Kinases/metabolism
- Proto-Oncogene Proteins/genetics
- Proto-Oncogene Proteins/metabolism
- Proto-Oncogene Proteins c-raf
- Proto-Oncogenes
- RNA/genetics
- RNA/isolation & purification
- RNA, Messenger/drug effects
- RNA, Messenger/genetics
- Receptors, Antigen, T-Cell/physiology
- Resting Phase, Cell Cycle
- S Phase
- T-Lymphocytes/drug effects
- T-Lymphocytes/immunology
- T-Lymphocytes/physiology
- Transcription, Genetic/drug effects
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190
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Kaplan G, Britton WJ, Hancock GE, Theuvenet WJ, Smith KA, Job CK, Roche PW, Molloy A, Burkhardt R, Barker J. The systemic influence of recombinant interleukin 2 on the manifestations of lepromatous leprosy. J Exp Med 1991; 173:993-1006. [PMID: 2007862 PMCID: PMC2190819 DOI: 10.1084/jem.173.4.993] [Citation(s) in RCA: 62] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
14 patients with lepromatous leprosy received twice daily injections of 10 micrograms recombinant interleukin 2 (rIL-2), by the intradermal route, in the skin of the back for 8 d (total dose, 160 micrograms). Lymphokine administration was accomplished without drug toxicity, or the development of acute nerve damage. The majority of patients developed nontender axillary lymphadenopathy during the course of treatment. Local injection sites showed progressively larger zones of induration, peaking at 24 h and persisting for many days. Early 12-h reactions were of a macular, erythematous nature and exhibited an increasingly striking diurnal variation. The morning injection sites were three- to fourfold larger in diameter than those placed in the evening (9 am to 9 pm). Systemic manifestations of intradermal rIL-2 administration were noted. Peripheral blood T cells, including CD4+ and CD8+ phenotypes, increased 2-2.5-fold and NK cells increased sixfold. Elevations in [3H]TdR incorporation into peripheral blood mononuclear cells occurred to a variety of mycobacterial antigens, but not to those of Mycobacterium leprae. Within 2 wk, biopsies at sites far removed from the back showed increased infiltration of mononuclear cells in 12 of 14 patients. Immunocytochemistry revealed the presence of newly emigrated CD4+ T cells, monocytes, and dermal CD1+ Langerhans cells. Endothelial cells of small dermal vessels expressed major histocompatibility complex class II determinants on their surface. Transmission electron microscopy of these specimens revealed markedly enlarged endothelial cells with many surface projections extending into the lumen as well as extravasating lymphoid cells. The numbers of acid-fast M. leprae in the peripheral sites were examined by slit smear and in biopsies of matched leprosy lesions taken before and after IL-2 administration. Within 2 mo, slit smears showed a 0.5 log or greater reduction in 12 of 14 patients, with a mean for all patients tested of 0.5 log units. Biopsy specimens showed a 1 log unit or greater reduction in the bacterial index (B.I.) in 6 of 14 patients. Historical controls in this Nepalese population showed a 0.5 log unit reduction after multidrug therapy over a period of 12 mo. Thus, after 8 d of IL-2 injections, a fivefold reduction in B.I. was observed during the first 2 mo of the study. Antibody levels against M. leprae phenolic glycolipid 1 (PGL-1) and lipoarabinomanan B were markedly elevated after IL-2 injections, while PGL-1 antigen levels were reduced. We conclude that the administration of rIL-2 has had a significant effect in decreasing the total body burden of M. leprae.(ABSTRACT TRUNCATED AT 400 WORDS)
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191
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Landgraf BE, Williams DP, Murphy JR, Smith KA, Ciardelli TL. Conformational perturbation of interleukin-2: a strategy for the design of cytokine analogs. Proteins 1991; 9:207-16. [PMID: 2006138 DOI: 10.1002/prot.340090306] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Interleukin-2 (IL-2) is a representative of a growing family of small proteins termed lymphokines which are responsible for mediating cell differentiation, growth and function in the immune system. Many of these proteins are being evaluated for their clinical potential. From the perspective of drug development, structure-function analysis of these molecules and their receptors require the use methodologies different than those traditionally employed for small peptides and other natural products. However, similar pharmacologic principles apply and an understanding of ligand-receptor interactions and the associated responses is required in order to efficiently pursue agonist and antagonist design. Although IL-2 is a protein of only 133 amino acid residues for which a low resolution X-ray structure does exist, the complexity of its receptor system has provided an added challenge to structure-function studies. Consequently, little is known concerning the receptor contact residues for this protein. We have attempted to utilize established principles of protein and peptide structure to manipulate the conformation of IL-2 in a manner which has provided analogs helpful for receptor interaction studies. These proteins have not only providing useful information on the nature of the IL-2 receptor but have also revealed potential strategies for the design of IL-2 agonists and antagonists.
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192
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Johnson KW, Smith KA. Molecular cloning of a novel human cdc2/CDC28-like protein kinase. J Biol Chem 1991; 266:3402-7. [PMID: 1704889] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
A homology probing approach was utilized to isolate a new human protein kinase. Deoxyoligonucleotide probes recognizing a conserved subdomain in the COOH-terminal portion of protein kinases identified a cDNA clone encoding a putative kinase with predicted serine/threonine phosphorylation specificity. The full-length, 1.7-kilobase pair cDNA hybridizes to 1.7- and 3.4-kilobase mRNA transcripts in a number of tissues. The size of the encoded protein is 454 amino acids and consists of an NH2-terminal 130-residue segment, which may represent a regulatory region, followed by a 324-residue catalytic domain. Comparisons and alignments of the primary sequence and predicted secondary structure of the catalytic region to other known kinases reveal that the new kinase, denoted "CLK" (for CDC-like kinase), represents a prototype for a new family of human protein kinases bearing significant homology to the yeast cdc2/CDC28 kinases that regulate the cell cycle.
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193
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Ehlers S, Smith KA. Differentiation of T cell lymphokine gene expression: the in vitro acquisition of T cell memory. J Exp Med 1991; 173:25-36. [PMID: 1898663 PMCID: PMC2118764 DOI: 10.1084/jem.173.1.25] [Citation(s) in RCA: 297] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
A simple in vitro experimental system was devised to reflect the in vivo generation of a T cell anamnestic response so that T cell differentiation could be examined at the level of lymphokine gene expression. Comparison of neonatal and adult T cells revealed that both populations expressed the genes for interleukin 2 (IL-2) and its receptor, but only adult T cells were capable of transcribing mRNAs for IL-3, IL-4, IL-5, IL-6, interferon gamma, and granulocyte/macrophage colony-stimulating factor. However, neonatal T cells could be induced to undergo functional differentiation in vitro, thereby acquiring the capacity to express the lymphokine gene repertoire characteristic for adult T cells. These data suggest that the T cells generated from neonatal blood by a primary stimulation in vitro are functionally indistinguishable from the T cells in adult blood that presumably have undergone primary stimulation in vivo. Therefore, we propose that the term "memory cell" be applied to those T cells that can be identified by their differentiated state of inducible effector-lymphokine gene expression.
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194
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195
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Zsebo KM, Wypych J, McNiece IK, Lu HS, Smith KA, Karkare SB, Sachdev RK, Yuschenkoff VN, Birkett NC, Williams LR. Identification, purification, and biological characterization of hematopoietic stem cell factor from buffalo rat liver--conditioned medium. Cell 1990; 63:195-201. [PMID: 2208278 DOI: 10.1016/0092-8674(90)90300-4] [Citation(s) in RCA: 562] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
We have identified a novel growth factor, stem cell factor (SCF), for primitive hematopoietic progenitors based on its activity on bone marrow cells derived from mice treated with 5-fluorouracil. The protein was isolated from the medium conditioned by Buffalo rat liver cells. It is heavily glycosylated, with both N-linked and O-linked carbohydrate. Amino acid sequence following removal of N-terminal pyroglutamate is presented. The protein has potent synergistic activities in semisolid bone marrow cultures in conjunction with colony-stimulating factors. It is also a growth factor for mast cells. In two companion papers, we present the sequences of partial SCF cDNAs, identify SCF as a c-kit ligand, and map the SCF gene to the Sl locus of the mouse.
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196
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Johnson KW, Smith KA. cAMP regulation of IL-2 receptor expression. Selective modulation of the p75 subunit. THE JOURNAL OF IMMUNOLOGY 1990. [DOI: 10.4049/jimmunol.145.4.1144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Abstract
As previous experiments have shown that IL-2 activity is abrogated by cAMP, its effect on IL-2R expression by normal and leukemic T lymphocytes was evaluated in detail. The exposure of murine or human T cells to dibutyryl cAMP or the cAMP-elevating drug, forskolin, resulted in a decrease in high affinity IL-2 binding. Equilibrium binding analyses revealed that elevation of cAMP for 4 to 5 h produced a 40 to 50% decrease in the number of detectable receptors, whereas the affinity of the IL-2R interaction remained unchanged. The effect of cAMP could be attributed to a selective effect on the 75-kDa chain of the IL-2R (p75) subunit of the 55-kDa chain of the IL-2R/p75 heterodimer. The mechanism for the decreased expression of high affinity IL-2R appears to be due to a dual effect of cAMP, which functions to both increase the rate of IL-2R internalization, and to decrease the rate of expression of new receptors. Moreover, the effect of cAMP on IL-2 binding to p75 subunits is post-transcriptional, because the steady state levels of p75 mRNA expression are not altered within a time interval that produced nearly a 50% reduction in p75 binding.
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197
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Johnson KW, Smith KA. cAMP regulation of IL-2 receptor expression. Selective modulation of the p75 subunit. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 1990; 145:1144-51. [PMID: 2166109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
As previous experiments have shown that IL-2 activity is abrogated by cAMP, its effect on IL-2R expression by normal and leukemic T lymphocytes was evaluated in detail. The exposure of murine or human T cells to dibutyryl cAMP or the cAMP-elevating drug, forskolin, resulted in a decrease in high affinity IL-2 binding. Equilibrium binding analyses revealed that elevation of cAMP for 4 to 5 h produced a 40 to 50% decrease in the number of detectable receptors, whereas the affinity of the IL-2R interaction remained unchanged. The effect of cAMP could be attributed to a selective effect on the 75-kDa chain of the IL-2R (p75) subunit of the 55-kDa chain of the IL-2R/p75 heterodimer. The mechanism for the decreased expression of high affinity IL-2R appears to be due to a dual effect of cAMP, which functions to both increase the rate of IL-2R internalization, and to decrease the rate of expression of new receptors. Moreover, the effect of cAMP on IL-2 binding to p75 subunits is post-transcriptional, because the steady state levels of p75 mRNA expression are not altered within a time interval that produced nearly a 50% reduction in p75 binding.
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198
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Abstract
Children with myelomeningocele have a variety of health and psychosocial needs that must be dealt with by the family, by health care providers, and by school staff. Bowel and bladder dysfunction are problems that are common in most of these children. Bladder dysfunction can lead to renal complications and, ultimately, may threaten the child's life. Bowel problems, including constipation and incontinence, can lead to medical complications and to severe social problems. This article discusses the pathophysiology of these problems and suggests nursing interventions, especially as they apply to children in the school setting.
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199
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Gao RS, Johnson LK, Hakes CL, Smith KA, Stebbings RF. Collisions of kilo-electron-volt H+ and He+ with molecules at small angles: Absolute differential cross sections for charge transfer. PHYSICAL REVIEW. A, ATOMIC, MOLECULAR, AND OPTICAL PHYSICS 1990; 41:5929-5933. [PMID: 9902992 DOI: 10.1103/physreva.41.5929] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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200
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Korybut-Woroniecka MI, Smith KA, Booyens J. Lipid composition of human colostrum in mothers having followed a diet devoid of either butter or margarine during pregnancy. Prostaglandins Leukot Essent Fatty Acids 1990; 40:161. [PMID: 2385614 DOI: 10.1016/0952-3278(90)90160-m] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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