101
|
Bell HA, Marris GC, Bell J, Edwards JP. The biology of Meteorus gyrator (Hymenoptera: Braconidae), a solitary endoparasitoid of the tomato moth, Lacanobia oleracea (Lepidoptera: Noctuidae). BULLETIN OF ENTOMOLOGICAL RESEARCH 2000; 90:299-308. [PMID: 11020788 DOI: 10.1017/s0007485300000420] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
There is a need to identify potential biological control agents for use against lepidopterous pests in greenhouses. The solitary endoparasitoid Meteorus gyrator (Thunberg) attacks a range of macrolepidopterous larvae, including those of some important horticultural pest species. Laboratory trials designed to investigate the biology of M. gyrator on larvae of the tomato moth, Lacanobia oleracea Linnaeus, reveal that this parasitoid is capable of parasitizing all larval stages of its host, third instars being parasitized most frequently. Each female parasitoid lives for up to 40 days (at 25 degrees C), ovipositing into an average of 78 hosts. Preadult development is rapid ( approximately 2 weeks), and the sex ratio of offspring is 1:1. Parasitism by M. gyrator suppresses the growth of both early and late host instars, and there is a concomitant reduction in the amount of food consumed (overall feeding reduction over a 12 day period is 68%). Our results indicate that inoculative releases of M. gyrator could provide effective biological control of L. oleracea and other noctuid pests of greenhouses.
Collapse
|
102
|
Audsley N, Weaver RJ, Edwards JP. The significance of Manduca sexta allatostatin in the tomato moth Lacanobia oleracea. Ann N Y Acad Sci 2000; 897:330-41. [PMID: 10676460 DOI: 10.1111/j.1749-6632.1999.tb07903.x] [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: 11/30/2022]
Abstract
The nature and regulation of juvenile hormone (JH) biosynthesis have been investigated in isolated corpora allata (CA) of adult males and females, and larvae of the tomato moth Lacanobia oleracea (Noctuidae). Larval CA (Vth day 1 to VIth day 1) appear to synthesize JH at very low rates (< 0.5 fmol/pr/h). This synthesis was not affected by Manduca sexta allatostatin (Mas-AS) nor Manduca sexta allatotropin. In contrast, adult female CA synthesize relatively high levels of JHI and JHII (> 10 pmol/pr/h), each of which can be inhibited (approx. 60%) by Mas-AS. CA from adult male L. oleracea do not produce detectable levels of JH but would appear to synthesize JH-acids instead, which can also be inhibited (approx. 50%) by Mas-AS. When assayed on adult female L. oleracea CA, brain extracts separated by liquid chromatography show inhibitory activity. The major biologically active fraction also has the greatest Mas-AS-like immunoreactivity and co-elutes with synthetic Mas-AS, indicating that most of the allatostatic activity in brain extracts is due to a Mas-AS-like peptide. In adult male brains, even though relatively high levels of immunoreactivity co-elute with synthetic Mas-As, the majority of the Mas-AS-like immunoreactivity is more hydrophobic.
Collapse
|
103
|
Kong JW, Hamann LG, Ruppar DA, Edwards JP, Marschke KB, Jones TK. Effects of isosteric pyridone replacements in androgen receptor antagonists based on 1,2-dihydro- and 1,2,3,4-tetrahydro-2,2-dimethyl-6-trifluoromethyl-8-pyridono[5,6-g]quin olines. Bioorg Med Chem Lett 2000; 10:411-4. [PMID: 10743937 DOI: 10.1016/s0960-894x(00)00010-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
A series of nonsteroidal human androgen receptor (hAR) antagonists based on 8-substituted 1,2-dihydro- and 1,2,3,4-tetrahydro-2,2-dimethyl-6-trifluoromethylpyrido[3,2-g]quin olines was synthesized. Compounds in this series were tested for the ability to bind to hAR and inhibit hAR-dependent transcription in a mammalian cellular background.
Collapse
|
104
|
Edwards JP, Hatton PA, Little RA, Pennington RA, Wareham AC. Increased quantal release of acetylcholine at the neuromuscular junction following scald injury in the rat. Muscle Nerve 1999; 22:1660-6. [PMID: 10567078 DOI: 10.1002/(sici)1097-4598(199912)22:12<1660::aid-mus7>3.0.co;2-j] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Following severe burns, patients frequently develop a profound resistance to nondepolarizing neuromuscular blockers. Several mechanisms have been proposed to account for this, including upregulation of nicotinic acetylcholine receptors. We investigated the effects of a 30% body surface area (BSA) scald on neuromuscular transmission in slow-twitch soleus (SOL) and fast-twitch extensor digitorum longus (EDL) of rats. Rats were sacrificed 72 h after the injury, a time at which sepsis is unlikely and body weight gain and core temperature have returned to normal. Further groups of rats were sham operated and either pair fed to the scalded rats or freely fed to assess the influence of food restriction. When compared with muscle from pair-fed control rats, scald resulted in an almost 50% increase in miniature endplate potential (mEPP) frequency in both SOL and EDL. However, scald did not increase mean mEPP amplitude in SOL, although it did cause a 10% increase in EDL. Scald injury did produce a significant increase in the size of the evoked endplate potential in SOL (33%) and EDL (37%). These data indicate that a significant increase in the quantal content of evoked transmitter released in SOL (38%) and EDL (30%) occurred by 72 h after scald. Such an increase may contribute to the resistance to nondepolarizing neuromuscular blockers documented in patients following thermal injury.
Collapse
|
105
|
Higuchi RI, Edwards JP, Caferro TR, Ringgenberg JD, Kong JW, Hamann LG, Arienti KL, Marschke KB, Davis RL, Farmer LJ, Jones TK. 4-Alkyl- and 3,4-dialkyl-1,2,3,4-tetrahydro-8-pyridono[5,6-g]quinolines: potent, nonsteroidal androgen receptor agonists. Bioorg Med Chem Lett 1999; 9:1335-40. [PMID: 10340624 DOI: 10.1016/s0960-894x(99)00186-9] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
A series of human androgen receptor (hAR) agonists based on 4-alkyl-; 4,4-dialkyl-; and 3,4-dialkyl-1,2,3,4-tetrahydro-8-pyridono[5,6-g]quinoline was synthesized and evaluated in competitive receptor binding assays and an androgen receptor cotransfection assay in a mammalian cell background. A number of compounds in this series demonstrated activity equal to or better than dihydrotestosterone in both assays and represent a novel class of compounds for use in androgen replacement therapy.
Collapse
|
106
|
Edwards JP, Higuchi RI, Winn DT, Pooley CL, Caferro TR, Hamann LG, Zhi L, Marschke KB, Goldman ME, Jones TK. Nonsteroidal androgen receptor agonists based on 4-(trifluoromethyl)-2H-pyrano[3,2-g]quinolin-2-one. Bioorg Med Chem Lett 1999; 9:1003-8. [PMID: 10230628 DOI: 10.1016/s0960-894x(99)00118-3] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
A series of 2H-pyrano[3,2-g]quinolin-2-ones was prepared and tested for the ability to modulate the transcriptional activity of the human androgen receptor (hAR). The parent compound, 4-(trifluoromethyl)-2H-pyrano[3,2-g]quinolin-2-one, displayed moderate interaction with hAR, but substituted analogues were potent hAR modulators in vitro as measured by an hAR cotransfection assay in CV-1 cells and bound to hAR with high affinity in a whole cell assay. Several analogues were able to activate hAR-mediated gene transcription more potently and efficaciously than dihydrotestosterone.
Collapse
|
107
|
Bellés X, Graham LA, Bendena WG, Ding QI, Edwards JP, Weaver RJ, Tobe SS. The molecular evolution of the allatostatin precursor in cockroaches. Peptides 1999; 20:11-22. [PMID: 10098619 DOI: 10.1016/s0196-9781(98)00155-7] [Citation(s) in RCA: 73] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Allatostatins (ASTs) of the Tyr/Phe-Xaa-Phe-Gly Leu/Ile-NH2 family are a group of insect neuropeptides that inhibit juvenile hormone biosynthesis by the corpora allata. We have obtained genomic DNA sequences that specify the preproallatostatin precursor for the cockroaches, Blatta orientalis, Blattella germanica, Blaberus (cranufer and Supella longipalpa. The sequences obtained are similar to those of Diploptera punctata and Periplaneta americana reported previously. The precursors of all these cockroach species are similar in size, and the organization of the ASTs that they contain (there are 13 or 14, depending on the species) have been conserved. With the sequences of these precursors, and using the homologous sequence in the orthopteran Schistocera gregari as an outgroup, a phylogenetic analysis using parsimony was carried out. The dendrograms obtained from these analyses. using the amino acid as well as the nucleotide sequences, are comparable with current models for cockroach phylogeny. Parsimony analysis was also used to study the genealogy of the different ASTs within the same precursor. Results suggest that the AST sequences were generated through a process of internal gene duplication which occurred before these species diverged from each other in evolutionary time.
Collapse
|
108
|
Zhi L, Tegley CM, Edwards JP, West SJ, Marschke KB, Gottardis MM, Mais DE, Jones TK. 5-Alkyl 1,2-dihydrochromeno[3,4-f]quinolines: a novel class of nonsteroidal progesterone receptor modulators. Bioorg Med Chem Lett 1998; 8:3365-70. [PMID: 9873735 DOI: 10.1016/s0960-894x(98)00608-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A series of nonsteroidal human progesterone receptor (hPR) agonists, 5-alkyl 1,2-dihydrochromeno[3,4-f]quinolines, was synthesized and evaluated in cotransfection and competitive receptor binding assays. The 5-alkyl substitution was shown to be responsible for the agonist activity and substitution at C9 dramatically enhanced the potency. A number of analogues in this series showed activities similar to or better than progesterone in the cotransfection and binding assays and analogue 15 exhibited similar in vivo activity as medroxyprogesterone acetate (MPA) in murine uterine wet weight/mammary gland morphology assays.
Collapse
|
109
|
Hamann LG, Winn DT, Pooley CL, Tegley CM, West SJ, Farmer LJ, Zhi L, Edwards JP, Marschke KB, Mais DE, Goldman ME, Jones TK. Nonsteroidal progesterone receptor antagonists based on a conformationally-restricted subseries of 6-aryl-1,2-dihydro-2,2,4-trimethylquinolines. Bioorg Med Chem Lett 1998; 8:2731-6. [PMID: 9873612 DOI: 10.1016/s0960-894x(98)00482-x] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
A series of nonsteroidal human progesterone receptor (hPR) antagonists based on conformationally-restricted analogues of a 6-aryl-1,2-dihydro-2,2,4-trimethylquinoline pharmacophore were synthesized and evaluated for their ability to bind to the human progesterone receptor and inhibit progesterone-stimulated reporter gene expression in mammalian cells.
Collapse
|
110
|
Pooley CL, Edwards JP, Goldman ME, Wang MW, Marschke KB, Crombie DL, Jones TK. Discovery and preliminary SAR studies of a novel, nonsteroidal progesterone receptor antagonist pharmacophore. J Med Chem 1998; 41:3461-6. [PMID: 9719599 DOI: 10.1021/jm9801915] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
A series of 6-aryl-1,2-dihydro-2,2,4-trimethylquinolines was synthesized and tested for functional activity on the human progesterone receptor isoform B (hPR-B) in mammalian (CV-1) cells. The lead compound LG001447 (1,2-dihydro-2,2, 4-trimethyl-6-phenylquinoline) was discovered via directed high throughput screening of a defined chemical library utilizing an hPR-B cotransfection assay. Electron-withdrawing substituents at the meta position of the C(6) aryl group afforded substantial improvements in hPR modulatory activity. Several analogues were able to potently block the effects of progesterone in vitro. Two compounds, 10 (LG120753) and 11 (LG120830) with potencies comparable or equal to the steroidal hPR antagonist onapristone (ZK98,299), were demonstrated to act as antiprogestins in vivo after oral administration to rodents. This is the first disclosure of orally active nonsteroidal antiprogestins.
Collapse
|
111
|
Edwards JP, Zhi L, Pooley CL, Tegley CM, West SJ, Wang MW, Gottardis MM, Pathirana C, Schrader WT, Jones TK. Preparation, resolution, and biological evaluation of 5-aryl-1, 2-dihydro-5H-chromeno[3,4-f]quinolines: potent, orally active, nonsteroidal progesterone receptor agonists. J Med Chem 1998; 41:2779-85. [PMID: 9667968 DOI: 10.1021/jm980190c] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Two potent nonsteroidal progestins from the 5-aryl-1, 2-dihydro-5H-chromeno[3,4-f]quinoline class (LG120746 and LG120747) were selected for scale-up, resolution, and biological evaluation of the purified enantiomers. For each quinoline, the levorotatory enantiomer was determined to be the more potent agonist of the human progesterone receptor isoform B (hPR-B) (EC50 < 3 nM), but the dextrorotatory enantiomers retained significant PR modulatory activity (EC50 < 200 nM). In two in vivo rodent models of progestational activity, a pregnancy maintenance assay and a uterine wet weight assay, the two eutomers displayed potent progesterone-like effects. In a third model for progestational activity, the mammary end bud assay, these compounds were significantly less active. These studies demonstrate that certain members of this class of selective progesterone receptor modulators display encouraging and potentially useful tissue-selective progestational effects.
Collapse
|
112
|
Edwards JP, Ringgenberg JD, Jones TK. Lewis-acid catalyzed reaction of 2-isopropenylaniline with ketones: Improved synthesis of 2,2,4-trisubstituted 1,2-dihydroquinolines. Tetrahedron Lett 1998. [DOI: 10.1016/s0040-4039(98)01010-7] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|
113
|
Edwards JP, West SJ, Pooley CL, Marschke KB, Farmer LJ, Jones TK. New nonsteroidal androgen receptor modulators based on 4-(trifluoromethyl)-2(1H)-pyrrolidino[3,2-g] quinolinone. Bioorg Med Chem Lett 1998; 8:745-50. [PMID: 9871534 DOI: 10.1016/s0960-894x(98)00107-3] [Citation(s) in RCA: 68] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
A series of 2(1H)-pyrrolidino[3,2-g]quinolinones was prepared and tested for the ability to modulate the transcriptional activity of the human androgen receptor (hAR). The parent compound, 4-(trifluoromethyl)-2(1H)-pyrrolidino[3,2-g]quinolinone, displayed moderate interaction with hAR, but more substituted analogues, particularly 6,7-disubstituted compounds, were potent hAR agonists in vitro.
Collapse
|
114
|
Edwards JP, Hatton PA, Wareham AC. Electrophysiology of the neuromuscular junction of the laminin-2 (merosin) deficient C57 BL/6J dy2J/dy2J dystrophic mouse. Brain Res 1998; 788:262-8. [PMID: 9555049 DOI: 10.1016/s0006-8993(98)00010-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The C57 BL/6J dy2J/dy2J dystrophic mouse expresses an abnormal truncated form of the alpha2 subunit of the protein laminin-2 (or merosin), which is unable to form a stable link between the extracellular matrix and the dystrophin-associated proteins, resulting in muscular dystrophy. Morphological abnormalities of the peripheral nervous system and neuromuscular junction have also been reported. The electrophysiological properties of the neuromuscular junctions of diaphragm, extensor digitorum longus (EDL), and soleus from C57 BL/6J dy2J/dy2J mice and controls are described. No evidence for the presence of denervated fibres were found. Mean MEPP amplitudes were significantly increased in EDL and soleus but reduced in the diaphragm from affected mice. Mean MEPP frequencies were raised in all the dy2J/dy2J muscles studied. dy2J/dy2J muscles were paralysed by low concentrations of mu-conotoxin suggesting that embryonic (tetrodotoxin and mu-conotoxin resistant) sodium channels are not widespread on dy2J/dy2J muscle as has previously been reported. EPP latencies were significantly prolonged in the diaphragm and EDL but not soleus from dy2J/dy2J mice. Quantal contents were higher in all dy2J/dy2J muscles. In the dy2J/dy2J diaphragm failures in neurotransmission occurred and a faster rate of rundown of EPPs were apparent. Some changes appear from a direct effect of dystrophy, whilst increased MEPP frequency and quantal content, and failures in neurotransmission indicate neuronal abnormalities.
Collapse
|
115
|
Hamann LG, Higuchi RI, Zhi L, Edwards JP, Wang XN, Marschke KB, Kong JW, Farmer LJ, Jones TK. Synthesis and biological activity of a novel series of nonsteroidal, peripherally selective androgen receptor antagonists derived from 1,2-dihydropyridono[5,6-g]quinolines. J Med Chem 1998; 41:623-39. [PMID: 9484511 DOI: 10.1021/jm970699s] [Citation(s) in RCA: 124] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
A new nonsteroidal antiandrogenic pharmacophore has been discovered using cell-based cotransfection assays with human androgen receptor (hAR). This series of AR antagonists is structurally characterized by a linear tricyclic 1,2-dihydropyridono[5,6-g]quinoline core. Analogues inhibit AR-mediated reporter gene expression and bind to AR as potently as or better than any known AR antagonists. Several analogues also showed excellent in vivo activity in classic rodent models of AR antagonism, inhibiting growth of rat ventral prostate and seminal vesicles, without accompanying increases in serum gonadotropin and testosterone levels, as is seen with other AR antagonists. Investigations of structure-activity relationships surrounding this pharmacophore resulted in molecules with complete specificity for AR, antagonist activity on an AR mutant commonly observed in prostate cancer patients, and improved in vivo efficacy. Molecules based on this series of compounds have the potential to provide unique and effective clinical opportunities for treatment of prostate cancer and other androgen-dependent diseases.
Collapse
|
116
|
Edwards JP, West SJ, Marschke KB, Mais DE, Gottardis MM, Jones TK. 5-Aryl-1,2-dihydro-5H-chromeno[3,4-f]quinolines as potent, orally active, nonsteroidal progesterone receptor agonists: the effect of D-ring substituents. J Med Chem 1998; 41:303-10. [PMID: 9464361 DOI: 10.1021/jm9705770] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Several 5-(4-chlorophenyl)-1,2-dihydro-5H-chromeno[3,4-f]quinolines were prepared to determine the effects of substitution at C(8) and C(9) on the progestational activity of this pharmacophore. In combination with a halogen (F or Cl) at C(9), replacement of the C(5) aryl group with variously substituted aryl groups resulted in optimization of the progestational activity, affording compounds with in vitro activity greater than that of progesterone as measured by a cotransfection assay using human progesterone receptor subtype-B (hPR-B). Binding affinities (Ki) to hPR-A were subnanomolar in many cases. These in vitro effects were verified in vivo using a rodent model. Compound 10 (LG120794, 9-chloro-5-(4-chlorophenyl)-1,2-dihydro-2,2,4-trimethyl-5H-chromeno++ +[3,4-f] quinoline) was more potent than medroxyprogesterone acetate at counterpoising the effects of estradiol benzoate in the uterine wet weight assay using immature rats.
Collapse
|
117
|
Denmark SE, Stavenger RA, Faucher AM, Edwards JP. Cyclopropanation with Diazomethane and Bis(oxazoline)palladium(II) Complexes. J Org Chem 1997; 62:3375-3389. [PMID: 11671727 DOI: 10.1021/jo970044z] [Citation(s) in RCA: 208] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Studies toward the development of an enantioselective diazomethane-based cyclopropanation reagent derived from bis(oxazoline)palladium(II) complexes are reported. Several simple palladium chelates, 2 and 7, in addition to the novel carbon-bound complexes 15 were synthesized and evaluated in the cyclopropanation of various electron-deficient olefins. The X-ray crystal structure of aryl-bis(oxazoline)palladium complex 15c is described. Although all catalysts efficiently affected cyclopropanation, all products were racemic. An intriguing relationship between substitution on the oxazoline ring, particularly the commonly-derivatized 4-position, and catalyst efficiency was discovered. The results are rationalized by either partial or complete bis(oxazoline) decomplexation during the course of the reaction.
Collapse
|
118
|
Daub GW, Edwards JP, Okada CR, Allen JW, Maxey CT, Wells MS, Goldstein AS, Dibley MJ, Wang CJ, Ostercamp DP, Chung S, Cunningham PS, Berliner MA. Acyclic Stereoselection in the Ortho Ester Claisen Rearrangement. J Org Chem 1997; 62:1976-1985. [PMID: 11671499 DOI: 10.1021/jo9614250] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The ortho ester Claisen rearrangement of trisubstituted allylic alcohols exhibits significant levels of diastereoselection. In E allylic alcohols, a 1,3-diaxial interaction develops in the chairlike transition state leading to the anti isomer, rendering the reaction syn selective by a factor of 3-5 to 1. In Z allylic alcohols, the 1,3-diaxial interaction develops in the transition state leading to the syn isomer, generating an anti:syn selectivity of 6-15 to 1. The relative stereochemistry of the syn isomer was confirmed independently by the synthesis of the mycotoxin botryodiplodin.
Collapse
|
119
|
Gray KJ, Porter C, Hawkey PM, Compton SG, Edwards JP. Roger's ants: a new pest in hospitals. BMJ (CLINICAL RESEARCH ED.) 1995; 311:129. [PMID: 7613391 PMCID: PMC2550188 DOI: 10.1136/bmj.311.6997.129b] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
|
120
|
Glinka AV, Braun RP, Edwards JP, Wyatt GR. The use of a juvenile hormone binding protein for the quantitative assay of juvenile hormone. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 1995; 25:775-781. [PMID: 7633465 DOI: 10.1016/0965-1748(94)00098-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
The suitability of the haemolymph juvenile hormone binding protein (JHBP) of Locusta migratoria for use in a competition assay for juvenile hormone (JH) III has been investigated, and a simple quantitative assay procedure using this protein has been developed. JHBP partially purified from haemolymph of precocene treated adult locusts gives rapid and stable binding of [3H]10R-JH III, and can be separated from the unbound hormone with hydroxylapatite (HAP). The sensitivity of the method is such that 0.15 pmol (40 pg) 10R-JH III gives 50% displacement of [3H]10R-JH III from the binding protein. Competition by JH II is about 5 times less and JH I about 10 times less than that by JH III, JH III diol and acid compete at least 1000 times less strongly. A procedure for extraction and assay of JH from 50 microliters haemolymph samples is described, the interference by non-specific haemolymph components is shown to be relatively small, and some data on JH III titres in maturing adult locusts are presented.
Collapse
|
121
|
Edwards JP, Lee CC, Duchen LW. The evolution of an experimental distal motor axonopathy. Physiological studies of changes in neuromuscular transmission caused by cycloleucine, an inhibitor of methionine adenosyltransferase. Brain 1994; 117 ( Pt 5):959-74. [PMID: 7953605 DOI: 10.1093/brain/117.5.959] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Cycloleucine (CL), a synthetic amino acid is known to cause degeneration of motor nerve terminals. This paper describes the changes in neuromuscular transmission, the morphology of motor end-plates and the responses of muscle spindles after a single dose of CL was administered to weanling and adult mice. Animals were allowed to survive for between 12 h and 7 days. Twitch and tetanic responses of muscles stimulated through their nerves fell dramatically within 24 h in both young and adult mice and intracellular recordings revealed that a large proportion of end-plates in calf muscles became denervated, whilst at other end-plates intermittent failure of transmission and end-plate potentials (EPPs) with prolonged latency were demonstrated. End-plates with an abnormally high frequency of miniature end-plate potentials (mEPPs) were found in young mice at 12 h, and in the adult mice at 24 h. Morphological abnormalities in intramuscular nerves and nerve terminals included areas of electron lucent axoplasm, swollen degenerative mitochondria and loss of synaptic vesicles. Over the next 2-3 days further reductions occurred in the number of end-plates at which mEPPs or EPPs could be demonstrated. At 7 days a limited recovery of function occurred in distal muscles but proximal muscles, hitherto unaffected, now began to show abnormalities of transmission. Muscle spindles were found to be both functionally and structurally intact. It is suggested that this acute distal motor axonopathy is due to abnormalities in phospholipid composition of the axolemma of motor nerve terminals resulting from the failure of methyl-transfer pathways. These abnormalities in phospholipid composition might cause an increase in microviscosity of the axolemma and hence a decrease in efficiency of ion channels and pumps responsible for maintaining electrochemical gradients, essential for the structural and functional integrity of the neuromuscular junction.
Collapse
|
122
|
Rowland-Jones SL, Phillips RE, Nixon DF, Gotch FM, Edwards JP, Ogunlesi AO, Elvin JG, Rothbard JA, Bangham CR, Rizza CR. Human immunodeficiency virus variants that escape cytotoxic T-cell recognition. AIDS Res Hum Retroviruses 1992; 8:1353-4. [PMID: 1466955 DOI: 10.1089/aid.1992.8.1353] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
|
123
|
|
124
|
Phillips RE, Rowland-Jones S, Nixon DF, Gotch FM, Edwards JP, Ogunlesi AO, Elvin JG, Rothbard JA, Bangham CR, Rizza CR. Human immunodeficiency virus genetic variation that can escape cytotoxic T cell recognition. Nature 1991; 354:453-9. [PMID: 1721107 DOI: 10.1038/354453a0] [Citation(s) in RCA: 797] [Impact Index Per Article: 24.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
In a longitudinal study of HIV seropositive patients, there were fluctuations in the specificity of cytotoxic T cells for the virus. This was matched by variability in proviral gag DNA epitope sequences in the lymphocytes of these patients. Some of these viral variants are not recognized by autologous T cells. Accumulation of such mutations in T-cell antigenic targets would provide a mechanism for immune escape.
Collapse
|
125
|
Weber T, Edwards JP, Denmark SE. Modified Proline Auxiliaries for Selective Addition of Organocerium Reagents to Hydrazones. Synlett 1989. [DOI: 10.1055/s-1989-20337] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|