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Peng WD, Xu SB, Peng X. Inhibitory effect of suberogorgin on acetylcholinesterase. ZHONGGUO YAO LI XUE BAO = ACTA PHARMACOLOGICA SINICA 1996; 17:369-72. [PMID: 9812727] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
AIM To study the selection, reversibility, and kinetics of suberogorgin (Sub) on acetylcholinesterase (AChE). METHODS The human plasma was used as butyrylcholinesterase (BuChE). The activity of ChE was determined with colorimetry. RESULTS Sub obviously inhibited the AChE in vitro with pl50 4.03, 4.92, 3.82, and 4.67 in RBC membranes (of rat and human) and tissue extracts (of rat brain and earthworm dorsal muscle), respectively. No inhibition on BuChE was observed. The inhibition of Sub on AChE was far lower than that of physostigmine, but was close to that of galanthamine. Sub decreased the AChE activity to the lowest within 3 min after it was incubated with AChE. Centrifugalization washing reactivated the AChE which had been inhibited by Sub. The double-reciprocal plots of different concentrations of Sub on AChE showed parallel lines. CONCLUSION Sub was a selective, reversible, and contra-competetive inhibitor of AChE at the binding site on the peripheral anion region of AChE.
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527
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Peng X, Maruo T, Samoto T, Mochizuki M. Comparison of immunocytologic localization of insulin-like growth factor binding protein-4 in normal and polycystic ovary syndrome human ovaries. Endocr J 1996; 43:269-78. [PMID: 8886620 DOI: 10.1507/endocrj.43.269] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
The cytologic localization and cellular levels of insulin-like growth factor binding protein-4 (IGFBP-4) in follicular and stromal compartments of normal and polycystic ovary syndrome (PCOS) ovaries during follicular growth and regression were investigated by the avidin/biotin immunoperoxidase method with a polyclonal antibody to human IGFBP-4, and a comparative assessment of IGFBP-4 expression in normal and PCOS ovaries was provided. In normal human ovaries, IGFBP-4 was immunolocalized to the oocyte throughout follicular growth, while the surrounding granulosa and theca cells were negligible for IGFBP-4 immunostaining in primordial, preantral and antral follicles. IGFBP-4 immunostaining became apparent, however, in the lutein cells of corpora lutea and the granulosa and theca cells of atretic follicles. In PCOS ovaries, prominent immunostaining for IGFBP-4 was apparent not only in the oocyte, but also in the surrounding granulosa cells in preantral follicles. In antral follicles from PCOS women without hyperinsulinemia, IGFBP-4 immunostaining was more prominent in the granulosa cells than the theca cells, whereas in antral follicles from PCOS women with hyperinsulinemia IGFBP-4 immunostaining was more prominent in the theca cells than the granulosa cells. Furthermore, in atretic follicles within PCOS ovaries IGFBP-4 immunostaining was prominent in the theca cells, regardless of the association of hyperinsulinemia. These results demonstrate for the first time that there is a great difference in cellular expression of IGFBP-4 between normal and PCOS human ovaries. In light of the high affinity of IGFBP-4 for IGF-1, the abundant expression of IGFBP-4 in granulosa and theca cells of preantral and antral follicles of PCOS ovaries may lead to decreases in the bioavailability of IGF-I in those follicles. The decrease in IGF-I-mediated stimulation of gonadotropin actions on granulosa and theca cells in preantral and antral follicles may impair the induction of aromatase activity, causing an androgenic microenvironment which is characteristic of atretic follicles and PCOS follicles.
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528
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Peng WD, Xu SB, Peng X. Effects of suberogorgin and its derivates on learning and memory in mice. ZHONGGUO YAO LI XUE BAO = ACTA PHARMACOLOGICA SINICA 1996; 17:215-8. [PMID: 9812738] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
AIM To study the relationship between the effects of suberogorgin (Sub) and its derivates on memory and their anti-acetylcholinesterase (AChE) actions. METHODS The step-down latency (SDL) and the escape latency (EL) of mice were determined at the same time in a passive avoidance task after Sub, N-suberogorgamide-N-N-dicyclohexyl urea (Sub-DU), or N-cyclohexyl suberogorgamide (N-CS) was injected i.p. The AChE activities in brain hemogenates were determined with colorimetry. RESULTS Sub 1.9, Sub-DU 3.0, or physostigmine (Phys) 0.15 mg.kg-1 obviously lengthened the SDL by 195%, 271%, and 210%, and shortened the EL by 56%, 61%, and 33%, and the two formers inhibited the brain AChE activities by 17% and 19%, respectively in aging (3-4 months) mice. These actions were decreased in a dose-dependent manner when Sub or Sub-DU was increased to 2.9-4.3 or 4.5-6.7 mg.kg-1 respectively. Sub 1.9, Sub-DU 2.0, and Phys 0.15 mg.kg-1 also lengthened the SDL by 187%, 209%, and 152%, and shortened the EL by 52%, 62%, and 57%, respectively in aged (12-14 months) mice. Sub 1.3-1.9, Sub-DU 0.9-2.0, or Phys 0.15 mg.kg-1 reversed the cycloheximide- or scopolamine-induced disruptions of memory retention. No obvious effect of N-CS on the acquisition of memory and the AChE activity in mice was observed. CONCLUSION The improvements of Sub and Sub-DU on memory were chiefly related to their anti-AChE actions.
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529
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Peng X, Angelastro JM, Greene LA. Tyrosine phosphorylation of extracellular signal-regulated protein kinase 4 in response to growth factors. J Neurochem 1996; 66:1191-7. [PMID: 8769883 DOI: 10.1046/j.1471-4159.1996.66031191.x] [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: 02/02/2023]
Abstract
Extracellular signal-regulated protein kinases (ERKs) are members of the mitogen-activated protein kinase family that are rapidly phosphorylated and activated in response to various extracellular stimuli, including growth factors. Of these, the ERK1 and ERK2 forms are by far the most abundant and the most studied. Much less is known about other ERK forms, including one previously designated ERK4 on the basis of its cross-reactivity with ERK1 and ERK2. We report here that ERK4 in rat PC12 pheochromocytoma cells can be immunoprecipitated by anti-ERK antiserum R2 and have used this re-agent to characterize this species further. We find that ERK4 rapidly becomes tyrosine-phosphorylated in response to nerve growth factor (NGF) and epidermal growth factor (EGF) and, to a lesser degree, in response to insulin and a permeant cyclic AMP analogue. As in the case of ERK1 and ERK2, tyrosine phosphorylation of ERK4 occurs by a ras-dependent pathway in response to NGF and EGF and shows prolonged kinetics for NGF but not EGF treatment. Recognition by multiple antisera directed against various domains of ERK1 supports classification of ERK4 within the ERK family; however, two-dimensional gel analysis clearly distinguishes ERK4 from isoforms of ERK1. These findings thus reveal an additional member of the ERK family that is responsive to growth factors and that could play a distinct role in intracellular signaling.
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530
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Lindstrom J, Anand R, Gerzanich V, Peng X, Wang F, Wells G. Structure and function of neuronal nicotinic acetylcholine receptors. PROGRESS IN BRAIN RESEARCH 1996; 109:125-37. [PMID: 9009699 DOI: 10.1016/s0079-6123(08)62094-4] [Citation(s) in RCA: 137] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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531
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Peng X, Hou Y. Demographic and social change in Jiangsu and Zhejiang between 1370 and 1900: a study of the genealogy of the Fan family. CHINESE JOURNAL OF POPULATION SCIENCE 1996; 8:361-72. [PMID: 12292590] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/19/2023]
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532
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Peng X, Coa S, Ke J. The effect of anisodamine on cerebral resuscitation of rats in acute cerebral ischemia from cardiac arrest. CHINESE MEDICAL SCIENCES JOURNAL = CHUNG-KUO I HSUEH K'O HSUEH TSA CHIH 1995; 10:237-239. [PMID: 8745587] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
In order to investigate the mechanisms of acute cerebral ischemia, and to look for effective drugs on cerebral resuscitation, we made a model of acute complete global brain ischemia, reperfusion and resuscitation on rats according to Garavilla's method. Our results showed that the event of cerebral ischemia and reperfusion injury could result in the increase of total brain calcium content, and anisodamine has the same reducing brain calcium contents as diltiazem's, while improving neurological outcome and alleviating injury to neurons.
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533
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Peng X, Mount SM. Genetic enhancement of RNA-processing defects by a dominant mutation in B52, the Drosophila gene for an SR protein splicing factor. Mol Cell Biol 1995; 15:6273-82. [PMID: 7565780 PMCID: PMC230879 DOI: 10.1128/mcb.15.11.6273] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
SR proteins are essential for pre-mRNA splicing in vitro, act early in the splicing pathway, and can influence alternative splice site choice. Here we describe the isolation of both dominant and loss-of-function alleles of B52, the gene for a Drosophila SR protein. The allele B52ED was identified as a dominant second-site enhancer of white-apricot (wa), a retrotransposon insertion in the second intron of the eye pigmentation gene white with a complex RNA-processing defect. B52ED also exaggerates the mutant phenotype of a distinct white allele carrying a 5' splice site mutation (wDR18), and alters the pattern of sex-specific splicing at doublesex under sensitized conditions, so that the male-specific splice is favored. In addition to being a dominant enhancer of these RNA-processing defects, B52ED is a recessive lethal allele that fails to complement other lethal alleles of B52. Comparison of B52ED with the B52+ allele from which it was derived revealed a single change in a conserved amino acid in the beta 4 strand of the first RNA-binding domain of B52, which suggests that altered RNA binding is responsible for the dominant phenotype. Reversion of the B52ED dominant allele with X rays led to the isolation of a B52 null allele. Together, these results indicate a critical role for the SR protein B52 in pre-mRNA splicing in vivo.
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534
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Peng X, Wang G, Zhang F. [Familial exudative vitreoretinopathy]. [ZHONGHUA YAN KE ZA ZHI] CHINESE JOURNAL OF OPHTHALMOLOGY 1995; 31:426-9. [PMID: 8762569] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Familial exudative vitreoretinopathy (FEVR) is an autosomal dominant inherited disease. The developmental abnormality of retinal vessels is the basis of various lesions in FEVR. 11 affected members (21 eyes) from 5 families with FEVR were studied. The emphasis was placed on describing the changes of fundus and fundus fluorescein angiography of the disease. Argon laser photocoagulation was performed on 8 patients (14 eyes) and they were followed for 5 approximately 14 months. The diagnosis, differential diagnosis, complications and treatment of FEVR were discussed with some materials in this paper.
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535
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Gerzanich V, Peng X, Wang F, Wells G, Anand R, Fletcher S, Lindstrom J. Comparative pharmacology of epibatidine: a potent agonist for neuronal nicotinic acetylcholine receptors. Mol Pharmacol 1995; 48:774-82. [PMID: 7476906] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Pharmacological properties of the (+)- and (-)-isomers of synthetic epibatidine, exo-2-(6-chloro-3-pyridyl)-7-azabicyclo-[2.2.1]heptane, were compared with nicotine and acetylcholine on several subtypes of chicken and human nicotinic acetylcholine receptors (AChRs). Both isomers of epibatidine behaved as extremely potent full agonists on chicken (alpha 3 beta 2, alpha 3 beta 4, alpha 4 beta 2, alpha 7, and alpha 8) and human (alpha 3 beta 2, alpha 3 beta 4, and alpha 7) neuronal AChRs expressed in Xenopus oocytes. Currents induced by epibatidine were effectively blocked by the nicotinic antagonists hexamethonium and mecamylamine. Apparent affinity was 100 to 1000-fold higher for epibatidine than for nicotine or acetylcholine. EC50 values ranged from 1 nM (for homomeric chicken alpha 8) to 2 microM (for homomeric chicken alpha 7). Epibatidine showed comparatively lower affinity for muscle-type AChRs from Torpedo and humans (EC50 values, 1.6 and 16 microM respectively). In binding assays, epibatidine was used on AChR subtypes immunoisolated from chicken brain and retina (alpha 4 beta 2, alpha 7, and alpha 8), the human neuronal cell line SH-SY5Y (alpha 3 and alpha 7), Torpedo electric organ (alpha 1 beta 1 gamma delta), or the human rhabdomyosarcoma cell line TE671 (alpha 1 beta 1 gamma delta). Both isomers of epibatidine exhibited extremely high affinity for all neuronal AChRs tested, with KI values ranging from 0.6 pM (human alpha 3 AChRs) to 0.6 microM (chicken alpha 7 AChRs). In contrast, epibatidine had lower affinity for Torpedo muscle-type AChRs (KI approximately 5 microM). Racemic [3H]epibatidine was an effective labeling reagent for human alpha 3 beta 2 AChRs, exhibiting a KD (0.14 nM) similar to the KI values observed for unlabeled (+)-epibatidine (0.23 nM) or (-)-epibatidine (0.16 nM).
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536
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Xu Z, Peng X, Ma H. [Relationship between kidney insufficiency and some endocrine hormones in periodontitis patients]. ZHONGHUA KOU QIANG YI XUE ZA ZHI = ZHONGHUA KOUQIANG YIXUE ZAZHI = CHINESE JOURNAL OF STOMATOLOGY 1995; 30:301-3. [PMID: 8728975] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
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537
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Ersdal-Badju E, Lu A, Peng X, Picard V, Zendehrouh P, Turk B, Björk I, Olson ST, Bock SC. Elimination of glycosylation heterogeneity affecting heparin affinity of recombinant human antithrombin III by expression of a beta-like variant in baculovirus-infected insect cells. Biochem J 1995; 310 ( Pt 1):323-30. [PMID: 7646463 PMCID: PMC1135891 DOI: 10.1042/bj3100323] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
In order to promote homogeneity of recombinant antithrombin III interactions with heparin, an asparagine-135 to alanine substitution mutant was expressed in baculovirus-infected insect cells. The N135A variant does not bear an N-linked oligosaccharide on residue 135 and is therefore similar to the beta isoform of plasma antithrombin. Purified bv.hat3.N135A is homogeneous with respect to molecular mass, charge and elution from immobilized heparin. Second-order rate constants for thrombin and factor Xa inhibition determined in the absence and presence of heparin are in good agreement with values established for plasma antithrombin and these enzymes. Based on far- and near-UV CD, bv.hat3.N135A has a high degree of conformational similarity to plasma antithrombin. Near-UV CD, absorption difference and fluorescence spectroscopy studies indicate that it also undergoes an identical or very similar conformational change upon heparin binding. The Kds of bv.hat3.N135A for high-affinity heparin and pentasaccharide were determined and are in good agreement with those of the plasma beta-antithrombin isoform. The demonstrated similarity of bv.hat3.N135A and plasma antithrombin interactions with target proteinases and heparins suggest that it will be a useful base molecule for investigating the structural basis of antithrombin III heparin cofactor activity.
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538
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Peng X, Greene LA, Kaplan DR, Stephens RM. Deletion of a conserved juxtamembrane sequence in Trk abolishes NGF-promoted neuritogenesis. Neuron 1995; 15:395-406. [PMID: 7646892 DOI: 10.1016/0896-6273(95)90043-8] [Citation(s) in RCA: 130] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Deletion of a conserved juxtamembrane sequence (KFG) in the Trk NGF receptor resulted in impaired neurite outgrowth, somatic hypertrophy, and induction of c-fos, c-jun, and TIS1 immediate-early genes. In contrast, these receptors retained the ability to mediate NGF-promoted survival and TIS8 and TIS11 immediate-early gene induction. The mutated receptor also mediated unimpaired autophosphorylation; SHC, PLC-gamma 1, and ERK tyrosine phosphorylation; and PI-3 kinase and ERK activation. However, SNT protein tyrosine phosphorylation, which wild-type receptors mediate via a ras-independent pathway, was undetectable. These findings indicate that the KFG sequence is indispensable for activating a ras-independent NGF signaling pathway involved in promoting neuronal differentiation and highlight potential roles of non-tyrosine-containing receptor domains in growth factor signal transduction.
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MESH Headings
- 1-Phosphatidylinositol 4-Kinase
- Adaptor Proteins, Signal Transducing
- Adaptor Proteins, Vesicular Transport
- Amino Acid Sequence
- Animals
- Calcium-Calmodulin-Dependent Protein Kinases/metabolism
- Cell Size
- Culture Media, Serum-Free
- Isoenzymes/metabolism
- Molecular Sequence Data
- Mutagenesis, Site-Directed
- Nerve Growth Factors/pharmacology
- Nerve Tissue Proteins/metabolism
- Neurites/drug effects
- Neurites/physiology
- Neurites/ultrastructure
- PC12 Cells
- Phospholipase C gamma
- Phosphorylation
- Phosphotransferases (Alcohol Group Acceptor)/metabolism
- Protein Processing, Post-Translational
- Proteins/metabolism
- Proto-Oncogene Proteins/chemistry
- Proto-Oncogene Proteins/genetics
- Proto-Oncogene Proteins/physiology
- Rats
- Receptor Protein-Tyrosine Kinases/chemistry
- Receptor Protein-Tyrosine Kinases/genetics
- Receptor Protein-Tyrosine Kinases/physiology
- Receptor, trkA
- Receptors, Nerve Growth Factor/chemistry
- Receptors, Nerve Growth Factor/genetics
- Receptors, Nerve Growth Factor/physiology
- Sequence Deletion
- Shc Signaling Adaptor Proteins
- Signal Transduction
- Src Homology 2 Domain-Containing, Transforming Protein 1
- Type C Phospholipases/metabolism
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539
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Zhang J, Peng X, Jonas A, Jonas J. NMR study of the cold, heat, and pressure unfolding of ribonuclease A. Biochemistry 1995; 34:8631-41. [PMID: 7612603 DOI: 10.1021/bi00027a012] [Citation(s) in RCA: 200] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The reversible cold, heat, and pressure unfolding of RNase A and RNase A--inhibitor complex were studied by 1D and 2D 1H NMR spectroscopy. The reversible pressure denaturation experiments in the pressure range from 1 bar to 5 kbar were carried out at pH 2.0 and 10 degrees C. The cold denaturation was carried out at 3 kbar, where the protein solution can be cooled down to -25 degrees C without freezing. Including heat denaturation experiments, the experimental data obtained allowed us to construct the pressure--temperature phase diagram of RNase A. The experimental results suggest the possibility that all three denaturation processes (cold, heat, and pressure) lead to non-cooperative unfolding. The appearance of a new histidine resonance in the cold-denatured and pressure-denatured RNase A spectra, compared to the absence of this resonance in the heat-denatured state, indicates that the pressure-denatured and cold-denatured states may contain partially folded structures that are similar to that of the early folding intermediate found in the temperature-jump experiment reported by Blum et al. [Blum, A. D., et al. (1978) J. Mol. Biol. 118, 305]. A hydrogen-exchange experiment was performed to confirm the presence of partially folded structures in the pressure-denatured state. Stable hydrogen-bonded structures protecting the backbone amide hydrogens from solvent exchange were observed in the pressure-denatured state. These experimental results suggest that the pressure-denatured RNase A displays the characteristics of a the inhibitor 3'-UMP show that the RNase A-inhibitor complex is more stable than RNase without the inhibitor.
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541
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Che J, Zhang J, Qu Z, Peng X. Effects of daurisoline on cytosolic free calcium in fetal rat cerebral cells. Chin Med J (Engl) 1995; 108:265-8. [PMID: 7789213] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Cytosolic free Ca2+ ([Ca2+]i) was measured in dissociated cerebral cells isolated from fetal rats with the fluorescent indicater fura-2. Increase in [Ca2+]i occurred rapidly following exposure of the cells to 50 mmol/L KCl, 10(-7) mol/L Bay K 8644 or 200 mumol/L glutamate (Glu). [Ca2+]i elevated by K(+)-depolarization was attenuated by pretreatment with 10(-7), 10(-6) mol/L daurisoline (Dau). The response of [Ca2+]i to K(+)-depolarization did not change when 10(-8) mol/L Dau was added. When 10(-8)-10(-6) mol/L Dau was added to the cell suspensions prior to exposure to Glu, the Glu-stimulated rises in [Ca2+]i were reduced significantly. However, Dau (10(-6), 10(-7) and 10(-8) mol/L) did not alter the response to Bay K 8644. These results indicate that Dau can inhibit the increase of [Ca2+]i in fetal rat cerebral cells induced by certain Ca2+ agonists, especially Glu, suggesting that this drug may have a protective effect against cerebral cellular injury.
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542
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Peng X, Jonas A, Jonas J. High pressure 2H-NMR study of the order and dynamics of selectively deuterated dipalmitoyl phosphatidylcholine in multilamellar aqueous dispersions. Biophys J 1995; 68:1137-44. [PMID: 7756533 PMCID: PMC1281836 DOI: 10.1016/s0006-3495(95)80288-2] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
High pressure 2H multipulse NMR techniques were used to investigate the effects of pressure on the structure and dynamics of selectively deuterated 1,2-dipalmitoyl-sn-glycero-3-phosphatidylcholine (DPPC) multilamellar aqueous dispersions. The samples were deuterated on both chains at positions 2, 9, or 13. The deuterium lineshapes, the spin-lattice relaxation times, T1, and the spin-spin relaxation times, T2, were measured as a function of pressure from 1 bar to 5 kbar at 50 degrees C for the three deuterated DPPC samples. This pressure range permitted us to explore the phase behavior of DPPC from the liquid-crystalline (LC) phase through various gel phases such as the Gel I (P beta), Gel II (L beta), Gel III, Gel X, and the interdigitated, Gel i, gel phase. Pressure had an ordering effect on all chain segments both in the LC phase and various high pressure gel phases as indicated by the increase in SCD bond order parameter and the first moment, M1, with pressure. Compared with the adjacent gel phases, the Gel i phase had the highest order. Also, in all gel phases the carbon-9 segment of the chains had the most restricted motions in contrast to the LC phase, where the carbon-2 segment was the most restricted. In the LC phase, T1 and T2 values for all segments decreased with pressure, indicative of the fast correlation time regime. Similarly, T1 decreased with pressure in the Gel I and the interdigitated Gel i gel phases but changed to the slow correlation time regime at the Gel i/Gel II phase transition. For T2, which reflects slow motions, the transition to the slow correlation time regime occurred already at LC/Gel I phase transition. Considering the various motions which contribute to relaxation, the behavior of T1 and T2 in the Gel 11 through Gel X phases showing discontinuities and slope changes at the phase transitions was, as expected, quite complex.In addition we found a straight line relationship for T-1 vs. S2D, and T-1 vs. S2CD for the deuterons in the 9 and 13 positions in the LC phase in the pressure range investigated.
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543
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Peng X. A new multipurpose CO2 laser therapy instrument. JOURNAL OF CLINICAL LASER MEDICINE & SURGERY 1995; 13:33-5. [PMID: 10150571 DOI: 10.1089/clm.1995.13.33] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
A new multipurpose CO2 laser therapy instrument has been developed. It is a highly efficient medical instrument. By use of high laser power density to coagulate, evaporate, and cut body tissue on the nidus, the operation can be controlled and has obvious curative effects. Unlike other kinds of CO2 laser therapy instruments, this device has an advanced switching power supply (SPS) and red guiding light system. With an overcurrent protective device, an overvoltage protective device, and a high-voltage shield device, it provides efficiency, stability, reliability, and low loss. The plastic casing does not leak electricity and the film switches are designed for clinical practice convenience. Additionally, the laser power is numerically displayed and can be set prior to the procedure. The distinct visible guiding light of the laser output makes the operation more convenient and accurate. Because of this unique design and properties, it is a leading model in China. The instrument can be widely used for surgery, gynecology, dermatology, and otolaryngology. The radiation therapy of low laser power density has the effect of being antiinflamatory, analgesic, and antipruritic, and promotes cure of the epithelium. Moreover, it is effective to treat all sorts of sprains, scapulohumeral periarthritis, arthritis, sciatica, and surface ulcers.
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544
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Liu J, Peng X, Mang K. cDNA cloning and sequence analysis of NIb gene of soybean mosaic virus. SCIENCE IN CHINA. SERIES B, CHEMISTRY, LIFE SCIENCES & EARTH SCIENCES 1995; 38:160-8. [PMID: 7755870] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
cDNA of soybean mosaic virus (Beijing isolate, SMV-BJ) has been synthesized, using viral genomic RNA as a template and random hexanucleotides as primers. Based on the sequences of SMV-BJ coat protein (CP) gene as well as SMV- and WMV-II-related regions, oligonucleotides were made as primers for polymerase chain reaction (PCR). NIb gene of SMV-BJ was amplified by PCR, and cloned into pBluescript SK. The complete sequence was determined. The comparison of NIb genes between SMV-BJ and WMV-II (USA) shows that similarities for nucleotide sequence reach 80.3%; and the deduced amino acid sequence, 91.3%. In consideration of the high identities in between the CP gene and the 3'-non-coding region between them, WMV-II might be considered as a watermelon strain of SMV. Besides, some unexpected sequences were found in the 3'-region of 2 NIb gene clones. Following modification and splicing, a binary vector of NIb gene has been constructed for its expression in higher plant for the purpose of studying the possible replicase-mediated resistance in polyviruses.
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545
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Peng X, Jonas A, Jonas J. One and two dimensional 1H-NMR studies of pressure and tetracaine effects on sonicated phospholipid vesicles. Chem Phys Lipids 1995; 75:59-69. [PMID: 7697783 DOI: 10.1016/0009-3084(94)02403-r] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
One and two dimensional 1H-NMR experiments have been performed to study the molecular order and dynamics of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) unilamellar vesicles under the influence of high pressure and the local anesthetic, tetracaine (TTC), which can also be considered as a model-charged amphiphile. The TTC molecules have an ordering effect on the headgroups but a disordering effect on the acyl chains, whereas, pressure has an ordering effect on the acyl chains. The results from 2D NOESY experiments on pure DPPC vesicles show that the intensities of NMe3/CH3, NMe3/(CH2)n, and CH3/(CH2)n cross-peaks increase with increasing pressure in the liquid-crystalline phase but decrease with pressure in the gel phase, further suggesting that the appearance of the cross-peaks between the two extremes of the DPPC molecules is due to spin-diffusion. For the DPPC/TTC vesicles, the 2D NOESY experiments confirm that charged TTC molecules are located in the headgroup region of the DPPC bilayers and, in the gel phase, also suggest the formation of an interdigitated gel phase.
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546
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Liu J, Huang S, Peng X, Liu W, Wang H. Studies on high salt tolerance of transgenic tobacco. CHINESE JOURNAL OF BIOTECHNOLOGY 1995; 11:275-80. [PMID: 8739106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
With E. coli mtlD gene (encoding mannitol 1-phosphate dehydrogenase) and gutD gene (encoding glucitol 6-phosphate dehydrogenase) cloned, plant expression vector pBIGM had been obtained by inserting mtlD and gutD genes into binary vector pBin438. Tobacco was transformed with A. tumefaciens LBA4404 containing pBIGM. Results of molecular hybridization of transformed plants indicated that mtlD and gutD genes had integrated into the genomic DNA of tobacco plants. Experiments of salt tolerance and analysis of sugar alcohols showed that the accumulation of different sugar alcohols in transgenic tobacco plants had increased salt tolerance of tobacco.
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547
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Tan D, Wang H, Peng X. [Treatment of recurrent carcinoma of the uterine cervix]. ZHONGHUA ZHONG LIU ZA ZHI [CHINESE JOURNAL OF ONCOLOGY] 1995; 17:47-9. [PMID: 7656788] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
One hundred thirty seven patients with recurrent carcinoma of the uterine cervix were treated from 1964 through 1985. The primary treatment was surgery in 64 cases and radiation of 73 cases. Treatment consisted of surgery (n = 13) radiotherapy with or without Chinese medicine (n = 92), chemotherapy (n = 26), and chemotherapy plus radiation (n = 6). The mean 5-year survival rate of this series was 40.9%. One patient survived 28 year without tumor. Seven of 13 surgically treated patients were alive and free of disease for 5 to 28 years with an average 5-year survival rate of 53.8%. Thirty recurrent cases following radiotherapy were again treated by radiation, 11 of them (36.7%) were alive for 5 years.
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548
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Peng X, Lang CM, Kreider JW. Methylation of cottontail rabbit papillomavirus DNA and tissue-specific expression in transgenic rabbits. Virus Res 1995; 35:101-8. [PMID: 7538718 DOI: 10.1016/0168-1702(94)00080-v] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Transgenic rabbits carrying multiple copies of CRPV genomic DNA were described previously (Peng et al. (1993) J. Virol. 67, 1698-1701). CRPV DNA was detectable in all tissues of the transgenic rabbits, however, the transcripts of CRPV genes only were found in skin and skin tumors. Tumor development was also restricted to skin. To study the mechanism involving tissue-specific expression of CRPV genes in rabbits, cellular DNAs, isolated from different normal tissues and skin tumors, were digested with the two isoschizomeric restriction endonucleases MspI (methylation resistant) and HpaII (methylation sensitive), respectively, and analyzed by Southern blot. CRPV DNA, especially its upstream regulatory region (URR), was extensively methylated in all normal tissues, but methylation was remarkably reduced in skin tumors. These data suggest that extensive methylation of CRPV genome, especially in the URR, might be a factor in controlling its tissue-specific expression.
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549
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Dominguez del Toro E, Juiz JM, Peng X, Lindstrom J, Criado M. Immunocytochemical localization of the alpha 7 subunit of the nicotinic acetylcholine receptor in the rat central nervous system. J Comp Neurol 1994; 349:325-42. [PMID: 7852628 DOI: 10.1002/cne.903490302] [Citation(s) in RCA: 213] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Previous molecular cloning studies have revealed that alpha-bungarotoxin binding proteins present in the brain are members of the neuronal nicotinic acetylcholine receptor gene family. The alpha 7 subunit is structurally related to the agonist binding subunits present in the central and peripheral nervous systems and, when expressed in Xenopus oocytes, forms functional channels blockable by alpha-bungarotoxin. In the present study, three different monoclonal antibodies raised against the alpha 7 subunit were used to map its distribution throughout the central nervous system of the rat. Immunohistochemical localization revealed that the alpha 7 subunit is expressed in most regions of the brain, being, overall, well correlated with previous "in situ" localization of alpha 7 transcripts and alpha-bungarotoxin autoradiographic binding studies. Particularly strong immunoreactivity was observed in several sensory and motor nuclei of the brainstem as well as the red nucleus. At the cellular level, alpha 7 immunostaining was usually found both in somata and dendrites, whereas axonal and terminal labeling was not observed. The widespread distribution of the alpha 7 subunit polypeptide is consistent with immunoprecipitation data demonstrating that it is a component of the predominant subtype of brain alpha-bungarotoxin-sensitive nicotinic receptors.
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550
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Tu P, Peng X. China's population: status and challenges. CHINA POPULATION TODAY 1994; 11:13-5. [PMID: 12319285] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/26/2023]
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