bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis of N‐(3‐azido‐4‐chlorophenyl)‐N′‐[3H‐methyl] thiourea, an efficient photoaffinity probe for the urea carrier
Authors: Lamotte Herve , Degeilh Francoise , Neau Philippe , Ripochet Pierre , Rousseau Bernard
Published: October 2006

Starting from commercial 4‐chloro‐3‐nitroaniline, through a 5 step synthesis, was prepared 3‐azido‐4‐chlorophenylisothiocyanate 5 which was reacted with [3H]‐methylamine. The latter was obtained by three methods:

[3H]‐LiAlT4 reduction of benzylcarbamate gave rise to [3H]‐methylamine (S.A.: >70 Ci/mmol).

Catalytic reduction of HCN with 3H2 lead to [3H]‐CH3NH2 (S.A.: 0.7 Ci/mmol).

Schmidt rearrangement of [3H]‐sodium acetate gave [3H]‐CH3NH2 (S.A.: 29 Ci/mmol).

Compound 7 at the highest specific activity had a self radiolysis rate precluding its practical use in biological studies whilst 29 Ci/mmol [3H]‐7 was satisfactory.
Tritiation of organic compounds by polymer‐supported acid catalysts
Authors: Brewer J. R. , Jones J. R. , Lawrie K. W. M. , Saunders D. , Simmonds A.
Published: October 2006

A range of organic compounds have been tritiated (and in some cases deuteriated) via hydrogen isotope exchange reactions using polymer supported acid catalysts. The extent and regiospecificity of labeling were investigated as a function of substrate and catalyst type. Although all the catalysts were found to be active in the tritiation of both aromatic and heterocyclic compounds, there was clear evidence that the extent of hydrogen isotope exchange was influenced by the nature of the polymer support matrix.
Synthesis of (N‐[11C]methyl)Y‐29794, a competitive inhibitor of prolyl endopeptidase
Authors: Charalambous A. , Mangner T. J. , Kilbourn M. R.
Published: October 2006

Prolyl endopeptidase (PEP: [E.C.3.4.21.26]) is a widely distributed serine peptidase that cleaves a variety of oligopeptides in the brain and peripheral tissues. Y‐29794 ((2‐(8‐dimethylaminooctylthio)‐6‐isopropyl‐3‐pyridyl‐2‐thienyl ketone) is a potent competitive reversible inhibitor of this enzyme. In order to study the biodistribution of PEP in vivo we have synthesized (N‐[11C]methyl)Y‐29794, by [11C]alkylation of the N‐desmethyl precursor. The radiotracer was purified by silica gel Sep‐Pak and was obtained in 10‐17% yields (EOB: synthesis times shorter than 45 min) with >98% radiochemical purities and specific activities >550 Ci/mmol (EOS).
Preparation of 17‐amino‐22‐(4′‐azido‐3′‐125iodophenacyl)‐17‐demethoxygeldanamycin (1): An ansamycin for photoaffinity labeling
Authors: Schnur Rodney C. , Corman Michael L.
Published: October 2006

An azido‐125iodo‐ansamycin (1) in the geldanamycin family was prepared in two steps in one reacton vessel from 17‐amino‐22‐(4′‐aminophenacyl)‐17‐demethoxygeldanamycin (3). The title compound was suitable for photoaffinity labeling proteins that interacted with ansamycins. A alternative synthesis is reported for preparation of unlabeled title compound in order to afford practical amounts of (1) for conventional biochemical studies.
Synthesis of an [125I]‐labelled derivative of MK‐571, a tool for LTD4 receptor studies
Authors: Li Chun‐Sing , Leblanc Yves , Zamboni Robert , Young Robert N.
Published: October 2006

An [125I]‐labelled derivative of MK‐571 2 was synthesized from the arylstanne derivative 11 in 50% radiochemical yield. Compound 2 is a useful tool for LTD4 receptor studies. The arylstanne intermediate 11 was obtained from the coupling reaction of (±)‐3‐[[[3‐[2‐(7‐chloro‐2‐quinolinyl)‐(E)‐ethenyl]phenyl][[3‐[(3‐aminopropyl)amino]‐3‐oxopropyl]thio]methyl]thio]propionic acid 10 with N‐hydroxysuccinimidyl 4‐trimethylstannylphenylacetate 3. The synthesis of 3 could be easily achieved from 4‐bromophenethyl alcohol.
Synthesis of sodium [11C]thiocyanate using [11C]cyanogen bromide
Authors: Westerberg Göran , Långström Bengt
Published: October 2006

A method for the preparation of sodium (11C]thiocyanate from [11C]cyanogen bromide and sodium sulfide is described. Sodium [11C]thiocyanate was obtained in 94% decay‐corrected radiochemical yield with a specific radioactivity of 122 GBq μmol−1 (3.3 Ci μmol−1) in a synthesis time of 21 minutes. The sodium [11C]thiocyanate was used in the synthesis of ethyl‐, isopropyl‐, and benzyl [11C]thiocyanate in 78, 71 and 84% radiochemical yields, respectively.
A new simple synthesis of 1,3‐dideuterated malondialdehyde (3‐hydroxy[1,3‐2H2]‐2‐propenal)
Authors: Allevi Pietro , Anastasia Mario , Ciuffreda Pierangela
Published: October 2006

A synthetic route for obtaining 1‐butoxy‐1,3,3‐triethoxy[1,3‐2H2]propane a stable diacetal of the malondialdehyde, is described. The synthesis involves the condensation of deuterated butylvinyl ether with deuterated triethyl orthoformate in the presence of montmorillonite clay K‐10. The deuteration of butyl vinyl ether was accomplished via the intermediary formation of a stannane derivative which was quantitatively metallated by n‐butyllithium and then treated with 2H2O. From the diacetal the 1,3‐dideuterated malondialdehyde was obtained by a short treatment with acid ion exchange resin.
Synthesis of carbon‐14 and tritiated steroidal 5α‐reductase inhibitors
Authors: Shu Arthur Y. L. , Heys J. Richard
Published: October 2006

17β‐[N‐(1,1‐Dimethylethyl)carbamoyl]androsta‐3,5‐diene‐4‐14C‐3‐carboxylic acid ([14C]SK&F 105657) was prepared via a three‐step sequence (t‐butyl amidation, triflation and carbomethoxylation) starting from androst‐4‐en‐3‐one‐4‐14C‐17β‐carboxylic acid. Its A‐ring aromatic analog 17β‐[N‐(1,1‐dimethylethyl)carbamoyl]estra‐1,3,5‐(10)‐triene‐3‐carboxylic acid (SK&F 105656) was labeled with tritium by means of iridium‐mediated exchange methodology.
A simple synthesis of 13C6‐labelled flavone and 5‐methoxyflavone
Authors: Ares Jeffrey J. , Wehmeyer Kenneth R.
Published: October 2006

The 13C6‐labelled molecules, flavone and 5‐methoxyflavone, with the carbon‐13 label at all six carbons of the aromatic B ring, have been prepared for use as internal standards in isotope dilution‐mass spectrometry. The key step involves addition of a labelled benzoyl group to the methyl group of a hydroxyacetophenone, forming a 1,3‐diketone. Overall yields from 13C6‐benzoic acid were 38% for the labelled flavone and 45% for the labelled 5‐methoxyflavone.
Synthesis of ethyl ω‐2H5‐docosa‐4, 7, 10, 13, 16, 19‐hexaenoate
Authors: Taber Douglass F. , You Kamfia
Published: October 2006

The preparation and subsequent Wittig reaction of phosphonium salt 4, a useful synthon for the preparation of polyunsaturated fatty acids, are reported. Salt 4 is a key intermediate for the synthesis of ethyl ω‐2H5‐docosa‐4,7,10,13,16,19‐hexaenoate (3).
Radiosynthesis of a new radioiodinated ligand for serotonin‐5HT2‐receptors, a promising tracer for γ‐emission tomography
Authors: Mertens J. , Terriere D. , Sipido V. , Gommeren W. , Janssen P. M. F. , Leysen J. E.
Published: October 2006

4‐Amino‐N‐[1‐[3‐(4‐fluorophenoxy)propyl]‐4‐methyl‐4‐piperidinyl]‐2‐methoxy‐benzamide, a compound with high affinity for 5HT2‐receptors, was radioiodinated on the 2‐position of the phenoxygroup or the 5‐position of the methoxybenzamide group. The former (obtained by Cu1+‐assisted radioiodo for bromo exchange) showed high lipophilicity and high non‐specific binding to rat brain tissue both in vitro and in vivo. The second labelled compound, 125I‐4‐amino‐N‐[1‐[3‐(4‐fluorophenoxy)propyl]‐4‐methyl‐4‐piperidinyl]‐5‐iodo‐2‐methoxybenza‐mide, obtained by direct electrophilic substitution, showed high affinity (Kd of 0.11 ± 0.01 nM) and marked selectivity for 5HT2‐receptors in vitro. Moreover in vivo studies in rats over the course of 1‐3 hrs post i.v. injection of the radioactive ligand, showed steady preferential retention of radioactivity in the frontal cortex, which is enriched in 5HT2 receptors. (Frontal cortex (FC) / Cerebellum ratio of 10 and FC / Blood ratio of 6, amount compound / mg tissue).
Synthesis of phenylalanines regiospecifically labelled with deuterium in the aromatic ring
Authors: Nishiyama Kozaburo , Oba Makoto , Ueno Ryuichi , Morita Ayako , Nakamura Yoshikuni , Kainosho Masatsune
Published: October 2006

Phenylalanines regiospecifically labelled with deuterium in the aromatic ring can be prepared through the hydrogenolysis of tyrosine tetrazolyl ethers using D2 gas and a medium pressure catalytic hydrogenator.
2‐Octyl‐4H‐1,3,2‐benzodioxaphosphorin 2‐oxide labelled with tritium in the octyl and aryl moieties
Authors: Wu Shao‐Yong , Yoshida Minoru , Casida John E.
Published: October 2006

2‐Octyl‐4H‐1,3,2‐benzodioxaphosphorin 2‐oxide (octyl‐BDPO) was labelled with tritium in the 7,8‐octyl and 6‐BDPO positions at specific activities of 38 and 16 Ci/mmol, respectively, by catalytic reductions of the corresponding olefin and bromo precursors with tritium gas. This potent mechanism‐based inhibitor for neuropathy target esterase (NTE) (I50 = 0.25 nM) and delayed neurotoxicant (active in hens at 3 mg/kg) was designed to determine phosphorylated NTE which retains the octyl label and differentiate aging with or without intramolecular group transfer (“alkylation”) reactions at the NTE active site from the fate of the aryl label.
Heterogeneous palladium‐catalyzed exchange labelling of representative organic compounds with tritium gas
Authors: Williams Philip G. , Than Chit , Rabbani Sadegh , Long Mervyn A. , Garnett John L.
Published: October 2006

A range of organic substrates was successfully exchanged with tritium gas using NaBH4‐reduced palladium oxide or chloride as catalyst. Exchange conditions involved a reaction temperature of 100 °C, a reaction time of 3 days, and products were analyzed by radio‐gas chromatography and 3H NMR spectroscopy. Both aromatic and aliphatic compounds underwent exchange, 18 of the 22 substrates incorporated > 35% of the available tritium, and most products showed high radiochemical purity. 3H NMR analyses showed that both alkanes and the alkyl chains of alkylbenzenes were rapidly and evenly labelled. Some aromatic compounds showed general ring exchange while others showed high specificity. These results for bulk palladium catalyst are strikingly different from those obtained with bulk platinum and supported palladium catalysts. The results are discussed in terms of currently accepted mechanisms of heterogeneous metal catalyzed hydrogen isotope exchange reactions.
Synthesis of the antiinflammatory prodrug RS‐42169‐14C
Authors: Parnes Howard , Huang Glenn T.
Published: October 2006

A facile synthesis of the antiinflammatory agent RS‐42169‐14C, based on a carbonation/cycloaddition sequence is described. The product was obtained in 36% yield from Ba14CO3 at a specific activity of 52 mCi/mmole. The design of the six step sequence was such that pure intermediates were isolated by extractive workup, and only a single chromatographic purification was required.
Synthesis of high specific activity [15,16‐3H2]buprenorphine
Authors: Ötvös Ferenc , Hosztafi Sándor , Simon Csaba , Tóth Géza
Published: October 2006

Tritium labelling of buprenorphine, a mixed agonist‐antagonist opioid ligand, was performed with a specific activity of 2.35 TBq/mmol (63.6 Ci/mmol) starting with 15,16‐didehydrobuprenorphine. Labels at positions 15 and 16 of the morphine skeleton proved to be sufficiently stable under strong acidic or basic conditions.
Synthesis and 15N NMR spectra of 1‐ and 4‐15N‐2,3,5‐trimethylpyrazines and their N‐oxides
Authors: Maeda Mikiko , Sakuma Chiseko , Kawachi Shinji , Tabei Katsumi , Kerim Ablikim , Kurihara Teruo , Ohta Akihiro
Published: October 2006

4‐15N‐2,3,5‐Trimethylpyrazine (1) was synthesized by dechlorination of 4‐15N‐6‐chloro‐2, 3, 5‐trimethylpyrazine (5) the key intermediate, derived from 15N‐DL‐alanine (3).

1‐15N‐2,3,5‐Trimethylpyrazine (2) was prepared by decarboxylation of 1‐15N‐2, 3, 5‐trimethyl‐pyrazine‐6‐carboxylic acid (10) obtained by the Pummerer type rearrangement of 1‐15N‐tetramethylpyrazine 1‐oxide (1) followed by oxidation.

1‐ And 4‐oxides and 1,4‐dioxides of the above 15Ntrimethylpyrazines were also obtained by treatment with sodium perborate in acetic acid.

15N NMR spectra of the compounds thus prepared were measured and the assignment of two 15N signals were certified.
Convenient synthesis of [2‐14C]‐methylglyoxal bis(guanylhydrazone), [14C]‐mitoguazone
Authors: Burgos Alain , Ellames George J.
Published: October 2006

[2‐14C]‐Methylglyoxal bis(guanylhydrazone) dihydrochloride, [14C]‐mitoguazone, 3, has been prepared in three steps from potassium [1‐14C]‐acetate in an overall radiochemical yield of 16%. The key steps in this procedure are the formation of the sodium salt of [acetone‐2‐14C]‐methylsulfinylacetone, 5, and Pummerer rearrangement to the [14C] labelled hemithioacetal, 6, which is trapped with two equivalents of aminoguanidine to afford the desired [14C] mitoguazone, 3.
Synthesis of the enantiomers of [3‐3H]‐2‐[[4‐[(7‐chloro‐4‐quinolinyl)‐amino]pentyl]ethylamino]ethanol, [3‐3H]‐hydroxychloroquine
Authors: Ellames George J. , Herbert John M. , Peace James E. , Smith David I. , Wedge Karen J.
Published: October 2006

The enantiomers of [3‐3H]‐2‐[[4‐[(7‐chloro‐4‐quinolinyl)amino]pentyl]ethylamino]ethanol,[3‐3H]‐hydroxychloroquine, (R)‐8 and (S)‐8, have been prepared in two steps from the known precursors 4,7‐dichloro‐3‐iodoquinoline,4, and the enantiomers of 2‐[(4‐aminopentyl)ethylamino]ethanol, (R)‐2 and (S)‐2, by formation of the enantiomers of 2‐[[4‐[(7‐chloro‐3‐iodo‐4‐quinolinyl)amino]pentyl]ethylamino]ethanol, (R)‐3 and (S)‐3, and subsequent reductive deiodination with tritium gas over 10% palladium on charcoal.
Synthesis and NMR characterization of selectively 15N‐labelled trans‐ and cis‐butenediamido‐linked bis‐netropsins
Authors: Plouvler Bertrand , Singh Malvinder P. , Lown J. William
Published: October 2006

The synthesis of specifically 15N labelled trans‐ and cis‐isomers of bis‐netropsins derived from 2‐butene‐1,4‐dicarboxylate as the central linker, namely the (E)‐ and (Z)‐forms of N‐[2‐[(3‐amino‐3‐iminopropyl)(15N)aminocarbonyl]‐1‐methylpyrrole‐4‐aminocarbonyl]‐1‐methylpyrrole‐4‐yl],N′‐[2‐[2‐[(3‐amino‐3‐Iminopropyl)aminocarbonyl]‐1‐methylpyrrole‐4‐aminocarbonyl]‐1‐methylpyrrol‐4‐yl]‐2‐butenediamide (18 & 28) are described. A highly convergent synthetic route was adopted for the preparation of the trans‐derivative starting from N‐methyl‐4‐nitro‐2‐trichloroacetylpyrrole and fumaroyl chloride. The most efficient methods of coupling aminopyrrole intermediates with activated carboxylic acid derivatives were utilized and the 15N‐labelled moleties were Incorporated In the later stages of the synthesis. The preparation of the cis‐derivative, starting with maleic anhydride, required a modification of the above strategy due to the nature of products formed upon Initial coupling with aminopyrrole derivatives. 1H‐ and 15N‐NMR were used to fully characterize the final products. The 1H NMR experiment allowed the assignment of an intramolecular hydrogen bond for the cis bis‐netropsin 28.
Synthesis of mycophenolate mofetil‐[14C], RS‐61443‐14C
Authors: Huang Glenn T. , Parnes Howard
Published: October 2006

Synthesis of the potent immunosuppressive agent, mycophenolate mofetil (1) labelled with carbon‐14 is described. Methoxyethoxymethyl (MEM) protected mycophenolate norbromide (9) was prepared from unlabelled mycophenolic acid (2) using a modified Hunsdiecker reaction. A three step synthesis furnished the title compound, having a specific activity of 53.8 mCi/mmol, in 49.5% overall yield from K14CN.
Deuteration of acetanilides and other substituted aromatics using [Ir(COD)(Cy3P)(Py)]PF6 as catalyst
Authors: Hesk D. , Das P. R. , Evans B.
Published: October 2006

Deuterium exchange labelling using [Ir(COD)(Cy3P)(Py)]PF6 as catalyst and deuterium gas was studied on a number of substituted acetanilides. In most cases products containing deuterium ortho to the anilide group were obtained with a high degree of enrichment. With one exception no evidence for meta, para or anilide methyl labelling was seen. The catalyst was also effective in the ortho deuteration of acetophenone, benzophenone and the β‐lactam containing compound Sch 48461.
The 18F‐labelled alkylating agent 2,2,2‐trifluoroethyl triflate: Synthesis and specific activity
Authors: Johnström Peter , Stone‐Elander Sharon
Published: October 2006

A method for synthesizing the alkylating agent 2,2,2‐trifluoroethyl triflate labelled with [18F]fluoride in the two position is presented. Ethyl [2‐18F]‐trifluoroacetate was synthesized by the nucleophilic reaction of [18F]F− with ethyl bromodifluoroacetate in DMSO (45‐60%, 5 min, 80 °C) and subsequently converted to [2‐18F]‐2,2,2‐trifluoroethanol using alane in THF (85‐95%, 2 min, 40 °C). Reaction with triflic anhydride in 2,6‐lutidine produced [2‐18F]‐2,2,2‐trifluoroethyl triflate (70‐80%, 1 min, 0 °C). In all three cases the product was removed from the reaction vessel by heating to distil under a stream of nitrogen. [2‐18F]‐2,2,2‐Trifluoroethyl triflate was used to label 2‐oxoquazepam by N‐alkylation in a toluene: DMF mixture (80‐85%, 20 min, 120 °C). Although no‐carrier‐added [18F]F− was used, considerable unlabelled ethyl trifluoroacetate was produced in the first reaction. Varying the conditions for the fluoro‐debromination reaction did not appreciably improve the relative ratio of labelled to unlabelled ester. The specific activity of the labelled 1,4‐benzodiazepine‐2‐one obtained from 1850 MBq [18F]F− was found to be ≈37 MBq/μmol (1 mCi/μmol).
Synthesis of [3H]DIPPA: A potent irreversible antagonist selective for the κ opioid receptor
Authors: Chang An‐Chih , Trometer Joseph D. , Portoghese Philip S.
Published: October 2006

2‐(3,4‐Dichlorophenyl)‐N‐methyl‐N‐[(1S)‐1‐(3‐isothiocyanatophenyl)‐2‐(1‐pyrrolidinyl)ethyl]acetamide (1, DIPPA) has been previously reported to be an opioid receptor affinity label that produces selective and long‐lasting κ opioid receptor antagonism in mice, High specific activity [3H]DIPPA (39.7 Ci/mmol) was prepared by bromination and catalytic tritiation of the amino precursor of DIPPA followed by conversion to the isothiocyanate with thiophosgene.
Synthesis and characterization of 7α‐O‐iodoallyl diprenorphine: A new ligand for potential spect imaging of opioid receptors
Authors: Wang R. F. , Tafani J. A. M. , Bergon M. , Tisnes P. , Coulais Y. , Zajac J. M. , Guiraud R.
Published: October 2006

The preparation and synthesis of [125I]7α‐O‐iodoallyl diprenorphine, a high affinity opioid receptor antagonist, is described using a versatile vinylstannane as prosthetic group for radioiodination at the tertiary alcohol group in the 7α‐side chain. Radioiododestannylation with selective conditions in one step occurs under mild, no‐carrier‐added‐conditions to give the corresponding [125I]7α‐O‐iodoallyl diprenorphine analogue in good radiolabelled yields (70‐90%) with specific radioactivity 80 TBq/mmol (2200 Ci/mmol) and radiochemical purity > 95%. Iodoallyl diprenorphine exhibited in vitro a very high affinity (Ki = 0.4 nM), so that this radioligand could be suitable for imaging opioid receptors in living humans by Single Photon Emission Computed Tomography (SPECT).
Syntheses of isotopically labeled 4‐[1‐(3,5,5,8,8‐pentamethyl‐5,6,7,8‐tetrahydro‐2‐naphthyl)ethenyl]benzoic acid (LGD1069), a potent retinoid x receptor‐selective ligand
Authors: Zhang Lin , Badea Beth Ann , Enyeart Debra , Berger Elaine M. , Mais Dale E. , Boehm Marcus F.
Published: October 2006

LGD1069, 4‐[1‐(3,5,5,8,8‐pentamethyl‐5,6,7,8‐tetrahydro‐2‐naphthyl)ethenyl] benzoic acid, is the first retinoid X receptor (RXR) selective retinoid to enter clinical trials for treatment of dermatological diseases and cancer. In order to examine biological properties such as receptor binding, metabolism and bioavailability, [13C]‐, [14C]‐, and [3H]‐labeled LGD1069 is required. Herein, we describe synthetic methods for preparing isotopically labeled homologs of LGD1069 as well as comparative competition binding data for [6,7‐3H]‐LGD1069 and [3H]‐9‐cis retinoic acid with RXR active retinoids. The final radiolabeled products, [6,7‐3H]‐LGD1069 and 3‐[14C]‐LGD1069 have specific activities of 56 Ci/mmol and 49 mCi/mmol, respectively. Radiochemical purities are 99.5% for [6,7‐3H]‐LGD1069 and 99.0% for 3‐[14C]‐LGD1069. The chemical purity is 99.0% for 3‐[13CD3]‐LGD1069. Competition binding studies with known retinoids show similar Kd values when either [6,7‐3H]‐LGD1069 or [3H]‐9‐cis retinoic acid is used as the radioligand.
Enantioselective synthesis of isotopically labelled L‐α‐amino acids preparation of 13C‐, 18O‐and 2H‐labelled L‐serines and L‐threonines
Authors: Karstens W. F. J. , Berger H. J. F. F. , Van Haren E. R. , Lugtenburg J. , Raap J.
Published: October 2006

[3‐18O]‐L‐serine, [3‐13C]‐L‐serine, [3‐18O]‐L‐threonine, [3,4‐13C2]‐L‐threonine and [3‐2H]‐L‐threonine are prepared from simple commercially available, isotopically enriched starting materials like H218O, [13C]‐paraformaldehyde, [13C2]‐acetaldehyde and [1‐2H]‐acetaldehyde. The introduction of the side chain is based on the reaction of the anion of the bislactimether of cyclo‐(D‐Val‐Gly) with a suitable reagent. For serine this is isotopically labelled benzylchloromethylether, whereas for threonine labelled acetaldehyde is used in combination with chlorotitaniumtris[diethylamide], introducing both stereocentres in one single step. The isotopomers of serine and threonine are obtained on the gram scale in good yields and high enantiomeric and diasteriomeric excesses. New syntheses for [18O]‐benzylalcohol and isotopically enriched benzylchloromethylether are reported. Following the presented synthetic scheme these amino acids can be labelled at any position or at any combination of positions.
Synthese von 4, 4′ ‐Difluorbenzhydryl‐ [a14C] ‐1‐ Piperazin
Authors: Donnert D. , Schweer K. ‐H.
Published: October 2006

The synthesis of 4, 4′‐Difluorbenzhydryl‐[a14C] ‐1‐piperazin starting with Ba14CO3is described. The identity of the labelled compound was established by comparison with the unlabelled one, synthesized by the same method. The latter was identified with the aid of elementary analysis, mass‐ and infrared spectroscopy.
Embedded Design and Virtual Instrument Simplifies X-Ray Diffractometer Setup Automation
Authors: Jayapandian J. , Sheela O.K. , Thiruarul A. , Kalavathi S.
Published: October 2006

Embedded control programmable hardware and Windows-based Virtual Instruments (VI) simplify the design of automation in R&D laboratories. With minimal hardware and maximum support of software, the automation becomes more readily achievable (Jayapandian, J. Curr. Sci., 25 March 2006, 90(6) 765–70). A novel design is described for the control of a Siemens X-ray Diffractometer. The automation is achieved with custom-embedded hardware using an 89C2051 microcontroller that is compatible with a Universal Synchronous Bus port and a VI created using LabVIEW.
An Integrated High-Throughput System for mRNA Purification and Quantitation for Use in Identifying Gene Knockdown by RNA Interference
Authors: Wang Danhui , Douglas Derek , Kreader Carol , Van Dinther Jennifer , Valdes-Camin Rafael
Published: October 2006

Expression profiling and RNA interference (RNAi) studies require rapid and accurate ways to profile changes in gene expression. Such studies use methodologies for the isolation and subsequent analysis of mRNA because it is central to the transfer of genetic information within a cell. Quantitative reverse transcriptional PCR (RT-PCR) is routinely used to verify knockdown of gene expression mediated by RNAi, but its success is dependent upon the quality of the purified mRNA template. An automated system has been developed for the isolation and subsequent analysis of the mRNA. This system uses Sigma's SpyLine Poly A+ Capture Kit, a novel system for the rapid isolation of poly A+ mRNA from cultured mammalian cells for direct use in quantitative RT-PCR analysis. The automated method was used to identify effective RNAi gene knockdown. Results indicate that this approach has both the sensitivity and reproducibility necessary for measuring transcript levels following gene knockdown.
Problematic Bone Fixation with Pyrocarbon Implants in Proximal Interphalangeal Joint Replacement: Short-Term Results
Authors: HERREN D. B. , SCHINDELE S. , GOLDHAHN J. , SIMMEN B. R.
Published: October 2006

Seventeen pyrocarbon PIP prostheses were implanted into 14 patients, followed prospectively and reviewed clinically. The patients were assessed after a mean follow-up of 20.5 months subjectively by a VAS pain scale and radiographically. Significant pain relief was noted in all patients from a mean of 7.6 pre-operatively to 1.3 at final follow-up. Migration of one, or both, components was observed radiographically in eight joints and radiolucent lines were evident in three more cases. The clinical results of the implants which had migrated were less favourable for range of motion and grip strength than the stable joints of this series, although, statistically, the results were not significant. The number of possibly unstable prostheses in this series raises the question as to whether pyrocarbon is suitable for uncemented pressfit fixation in combination with early functional rehabilitation.
Linking Perceived Unfairness to Physical Health: The Perceived Unfairness Model
Authors: Jackson Benita , Kubzansky Laura D. , Wright Rosalind J.
Published: October 2006

Can perceiving unfairness influence physical health? To address this question the authors propose the Perceived Unfairness Model, synthesized from psychological and epidemiological research. The model starts from the premise that perceiving unfairness, directed at beings to which the perceiver is emotionally attached, activates a cascade of psychological and physical processes. This cascade may be experienced by low or high status group members, and by the target or observer of the perceived unfairness. With repeated episodes, the effects of perceiving unfairness may accumulate and compromise physical health. Whether perceiving unfairness is potentially toxic or benign is a function of two key components of social location: identity relevance and helplessness to redress the unfairness. The authors conclude by discussing directions for developing the model.
Neural evolution in the bat-free habitat of Tahiti: partial regression in an anti-predator auditory system
Authors: Fullard James H , Ratcliffe John M , ter Hofstede Hannah
Published: October 2006

Noctuid moths endemic to the mountains of Tahiti have evolved in an environment without bats and these insects have lost a defensive behaviour against these predators, the acoustic startle response (ASR). The ASR in noctuid moths is presumed to be activated by a single auditory receptor neuron (A2 cell) and we report that while this cell still exists in endemic species and possesses similar sensitivity thresholds compared to the A2 cell of recently introduced species, it exhibits reduced firing activity to ASR-evoking sounds. This partial neural regression suggests that the evolutionary disappearance of the ASR in these insects is incomplete and that sensoribehavioural integration decays gradually following the removal of stabilizing selective forces.
Seismic Rayleigh waves on an exponentially graded, orthotropic half-space
Authors: Destrade Michel
Published: October 2006

Efforts at modelling the propagation of seismic waves in half-spaces with continuously varying properties have mostly been focused on shear-horizontal waves. Here, a sagittally polarized (Rayleigh type) wave travels along a symmetry axis (and is attenuated along another) of an orthotropic material with stiffnesses and mass density varying in the same exponential manner with depth. In contrast to what could be expected at first sight, the analysis is very similar to that of the homogeneous half-space, with the main and capital difference that the Rayleigh wave is now dispersive. The results are illustrated numerically for (i) an orthotropic half-space typical of horizontally layered and vertically fractured shales and (ii) for an isotropic half-space made of silica. In both the examples, the wave travels at a slower speed and penetrates deeper than in the homogeneous case. In the second example, the inhomogeneity can force the wave amplitude to oscillate as well as decay with depth, in marked contrast with the homogeneous isotropic general case.
The re-emergence of felid camouflage with the decay of predator recognition in deer under relaxed selection
Authors: Stankowich Theodore , Coss Richard G
Published: October 2006

When a previously common predator disappears owing to local extinction, the strong source of natural selection on prey to visually recognize that predator becomes relaxed. At present, we do not know the extent to which recognition of a specific predator is generalized to similar looking predators or how a specific predator-recognition cue, such as coat pattern, degrades under prolonged relaxed selection. Using predator models, we show that deer exhibit a more rapid and stronger antipredator response to their current predator, the puma, than to a leopard displaying primitive rosettes similar to a locally extinct predator, an early jaguar. Presentation of a novel tiger with a striped coat engendered an intermediate speed of predator recognition and strength of antipredator behaviour. Responses to the leopard model slightly exceeded responses to a non-threatening deer model, suggesting that thousands of years of relaxed selection have led to the loss of recognition of the spotted coat as a jaguar-recognition cue, and that the spotted coat has regained its ability to camouflage the felid form. Our results shed light on the evolutionary arms race between adoption of camouflage to facilitate hunting and the ability of prey to quickly recognize predators by their formerly camouflaging patterns.
How slow breeding can be selected in seabirds: testing Lack's hypothesis
Authors: Dobson F. Stephen , Jouventin Pierre
Published: October 2006

The historical debate of the 1960s between group and individual selection hinged on how the slow breeding of seabirds could be explained. While this debate was settled by the ascendance of individual selection, championed by David Lack, explanations for slow breeding in seabirds remain to be tested. We examined the slowest breeding of these birds, the albatrosses and petrels (order Procellariiformes), using analyses that statistically controlled for variations in body size and phylogeny. Incubation and fledging periods appeared strongly correlated, but this turned out to be largely explained by phylogeny. Nonetheless, developmental and reproductive rates were associated with the distance to the foraging range, as predicted under the hypothesis of ecological constraints on breeding pairs, and these results were independent of body size and phylogeny. Slower breeding in these seabirds appeared associated with the rigors of farther pelagic feeding, as Lack originally hypothesized.
Sex differences in the onset of seasonal reproductive quiescence in hamsters
Authors: Beery Annaliese K , Trumbull Justin J , Tsao Jyeming M , Costantini Ruth M , Zucker Irving
Published: October 2006

Day length is the primary cue used by many mammals to restrict reproduction to favourable spring and summer months, but it is unknown for any mammal whether the seasonal loss of fertility begins at the same time and occurs at the same rate in females and males; nor it established whether the termination of mating behaviour in males and females coincides with the loss of fertility. We speculated that females, owing to their greater energetic investment in reproduction, are the limiting sex in terminating offspring production in short days (SDs). Oestrous cycles and production of young were monitored in Syrian hamsters (
Mesocricetus auratus
) transferred from long days (LDs) to SDs. Females were mated to LD males after three to eight weeks of SD treatment; in a parallel experiment, males housed in SDs were mated to LD females. After five and eight weeks in SDs, at least twice as many males as females were fertile. Both males and females continued to copulate for several weeks after becoming infertile. The onset of seasonal infertility occurs earlier in females than males and the decline in fertility precedes the seasonal loss of mating behaviour in both sexes.
Stepping stones towards a new prokaryotic taxonomy
Authors: Gevers Dirk , Dawyndt Peter , Vandamme Peter , Willems Anne , Vancanneyt Marc , Swings Jean , De Vos Paul
Published: October 2006

Technological developments provide new insights into prokaryotic evolution and diversity and provoke a continuous need to update taxonomy and revise classification schemes. Our present species concept and definition are being challenged by the growing amount of whole genomic information, which should allow improvements in the natural species definition. The continuous quest for an objective and stable method for sorting strains into coherent homogeneous groups is inherent to prokaryotic systematics and nomenclature. Morphological, biochemical, physiological, phenotypic and chemotaxonomic criteria have been complemented by molecular data and pragmatic, purpose built, species definitions are being replaced by more natural ones based on evolutionary insights. It is imperative to give due consideration to both fundamental and applied aspects of future species concepts and definitions. The present paper discusses the present practice in prokaryotic taxonomy of how this system developed and how it may evolve in the future.
The bacterial species definition in the genomic era
Authors: Konstantinidis Konstantinos T , Ramette Alban , Tiedje James M
Published: October 2006

The bacterial species definition, despite its eminent practical significance for identification, diagnosis, quarantine and diversity surveys, remains a very difficult issue to advance. Genomics now offers novel insights into intra-species diversity and the potential for emergence of a more soundly based system. Although we share the excitement, we argue that it is premature for a universal change to the definition because current knowledge is based on too few phylogenetic groups and too few samples of natural populations. Our analysis of five important bacterial groups suggests, however, that more stringent standards for species may be justifiable when a solid understanding of gene content and ecological distinctiveness becomes available. Our analysis also reveals what is actually encompassed in a species according to the current standards, in terms of whole-genome sequence and gene-content diversity, and shows that this does not correspond to coherent clusters for the environmental
Burkholderia
and
Shewanella
genera examined. In contrast, the obligatory pathogens, which have a very restricted ecological niche, do exhibit clusters. Therefore, the idea of biologically meaningful clusters of diversity that applies to most eukaryotes may not be universally applicable in the microbial world, or if such clusters exist, they may be found at different levels of distinction.
Mismatch induced speciation inSalmonella: model and data
Authors: Falush Daniel , Torpdahl Mia , Didelot Xavier , Conrad Donald F , Wilson Daniel J , Achtman Mark
Published: October 2006

In bacteria, DNA sequence mismatches act as a barrier to recombination between distantly related organisms and can potentially promote the cohesion of species. We have performed computer simulations which show that the homology dependence of recombination can causede novospeciation in a neutrally evolving population once a critical population size has been exceeded. Our model can explain the patterns of divergence and genetic exchange observed in the genusSalmonella, without invoking either natural selection or geographical population subdivision. If this model was validated, based on extensive sequence data, it would imply that the named subspecies ofSalmonella entericacorrespond to good biological species, making species boundaries objective. However, multilocus sequence typing data, analysed using several conventional tools, provide a misleading impression of relationships withinS. entericasubspeciesentericaand do not provide the resolution to establish whether new species are presently being formed.
The Liverwort Marchantia polymorpha Expresses Orthologs of the Fungal Agaricus bisporus Agglutinin Family
Authors: Peumans Willy J. , Fouquaert Elke , Jauneau Alain , Rougé Pierre , Lannoo Nausicaä , Hamada Hiroki , Alvarez Richard , Devreese Bart , Van Damme Els J.M.
Published: October 2006

A lectin different from the previously described mannose-binding agglutinins has been isolated from the liverwort Marchantia polymorpha. Biochemical characterization of the purified lectin combined with the data from earlier transcriptome analyses demonstrated that the novel M. polymorpha agglutinin is not related to any of the known plant lectin families, but closely resembles the Agaricus bisporus-type lectins, which hitherto have been found exclusively in fungi. Immunolocalization studies confirmed that lectin is exclusively associated with plant cells, ruling out the possibility of a fungal origin. Extensive screening of publicly accessible databases confirmed that, apart from fungi, the occurrence of A. bisporus-type lectins is confined to M. polymorpha and the moss Tortula ruralis. Expression of a typical fungal protein in a liverwort and a moss raises the question of the origin of the corresponding genes. Regardless of the evolutionary origin, the presence of a functional A. bisporus lectin ortholog in M. polymorpha provides evidence for the expression of an additional carbohydrate-binding domain in Viridiplantae.
SIZ1 Small Ubiquitin-Like Modifier E3 Ligase Facilitates Basal Thermotolerance in Arabidopsis Independent of Salicylic Acid
Authors: Yoo Chan Yul , Miura Kenji , Jin Jing Bo , Lee Jiyoung , Park Hyeong Cheol , Salt David E. , Yun Dae-Jin , Bressan Ray A. , Hasegawa Paul M.
Published: October 2006

Small ubiquitin-like modifier (SUMO) conjugation/deconjugation to heat shock transcription factors regulates DNA binding of the peptides and activation of heat shock protein gene expression that modulates thermal adaptation in metazoans. SIZ1 is a SUMO E3 ligase that facilitates SUMO conjugation to substrate target proteins (sumoylation) in Arabidopsis (Arabidopsis thaliana). siz1 T-DNA insertional mutations (siz1-2 and siz1-3; Miura et al., 2005) cause basal, but not acquired, thermosensitivity that occurs in conjunction with hyperaccumulation of salicylic acid (SA). NahG encodes a salicylate hydroxylase, and expression in siz1-2 seedlings reduces endogenous SA accumulation to that of wild-type levels and further increases thermosensitivity. High temperature induces SUMO1/2 conjugation to peptides in wild type but to a substantially lesser degree in siz1 mutants. However, heat shock-induced expression of genes, including heat shock proteins, ascorbate peroxidase 1 and 2, is similar in siz1 and wild-type seedlings. Together, these results indicate that SIZ1 and, by inference, sumoylation facilitate basal thermotolerance through processes that are SA independent.
A Pentatricopeptide Repeat Protein Facilitates the trans-Splicing of the Maize Chloroplast rps12 Pre-mRNA
Authors: Schmitz-Linneweber Christian , Williams-Carrier Rosalind E. , Williams-Voelker Pascale M. , Kroeger Tiffany S. , Vichas Athea , Barkan Alice
Published: October 2006

The pentatricopeptide repeat (PPR) is a degenerate 35–amino acid repeat motif that is widely distributed among eukaryotes. Genetic, biochemical, and bioinformatic data suggest that many PPR proteins influence specific posttranscriptional steps in mitochondrial or chloroplast gene expression and that they may typically bind RNA. However, biological functions have been determined for only a few PPR proteins, and with few exceptions, substrate RNAs are unknown. To gain insight into the functions and substrates of the PPR protein family, we characterized the maize (Zea mays) nuclear gene ppr4, which encodes a chloroplast-targeted protein harboring both a PPR tract and an RNA recognition motif. Microarray analysis of RNA that coimmunoprecipitates with PPR4 showed that PPR4 is associated in vivo with the first intron of the plastid rps12 pre-mRNA, a group II intron that is transcribed in segments and spliced in trans. ppr4 mutants were recovered through a reverse-genetic screen and shown to be defective for rps12 trans-splicing. The observations that PPR4 is associated in vivo with rps12-intron 1 and that it is also required for its splicing demonstrate that PPR4 is an rps12 trans-splicing factor. These findings add trans-splicing to the list of RNA-related functions associated with PPR proteins and suggest that plastid group II trans-splicing is performed by different machineries in vascular plants and algae.
A p67Phox-Like Regulator Is Recruited to Control Hyphal Branching in a Fungal–Grass Mutualistic Symbiosis
Authors: Takemoto Daigo , Tanaka Aiko , Scott Barry
Published: October 2006

Key requirements for microbes to initiate and establish mutualistic symbiotic interactions with plants are evasion of potential host defense responses and strict control of microbial growth. Reactive oxygen species (ROS) produced by a specific NADPH oxidase isoform, NoxA, regulate hyphal growth in the mutualistic interaction between the fungal endophyte Epichloë festucae and its grass host Lolium perenne. Unlike mammalian systems, little is known about the fungal NADPH oxidase complex and its response to differentiation signals. We identify an E. festucae p67phox-like regulator, NoxR, dispensable in culture but essential in planta for the symbiotic interaction. Plants infected with a noxR deletion mutant show severe stunting and premature senescence, whereas hyphae in the meristematic tissues show increased branching leading to increased fungal colonization of pseudostem and leaf blade tissue. Inhibition of ROS production or overexpression of noxR recapitulates the hyperbranching phenotype in culture. NoxR interacts in vitro with the small GTP binding protein RacA and requires a functional RacA binding site to complement the noxR mutant and restore the wild-type plant interaction phenotype. These results show that NoxR is a key regulator of NoxA in symbiosis, where it acts together with RacA to spatially regulate ROS production and control hyphal branching and patterning.
Low dose recombinant human growth hormone normalizes bone metabolism and cortical bone density and improves trabecular bone density in growth hormone deficient adults without causing adverse effects
Authors: Amato Giovanni , Izzo Giovanni , La Montagna Giovanni , Bellastella Antonio
Published: October 2006

OBJECTIVES Prolonged GH deficiency Induces alterations In bone metabolism and structure. Trials In GH deficient adults (GHDA) employing high dose GH replacement therapy produced conflicting results, and caused several adverse effects. This prompted us to study the effects of rhGH treatment on bone metabolism and structure at lowest doses so far used.

DESIGN Nine GHDA (7 males and 2 females, aged 25–34 years) were studied before, after 12 months of rhGH treatment (70 μg/kg/week, divided Into 3 Injections, administered s.c. at 2000 h on Monday, Wednesday and Friday, respectively) and after 12 months off therapy.

MEASUREMENTS Serum IGF‐I, IGFBP‐3, bone‐gla‐protein (BOP), procollagen‐III (PIIINP), PTH and vitamin D, and bone mineral density (BMD) at proximal (Prox) and ultradistal (Dist) sites of the radius were measured.

RESULTS Before treatment, IGF‐I, IGFBP‐3, BGP and PIIINP levels, as well as both Prox and Dist BMD, were significantly lower than In controls. GH therapy normalized all these parameters, except for the Dist value, which nonetheless Increased. No significant changes In PTH and vitamin D variation were seen. After 12 months off therapy all parameters returned to pretreatment levels.

CONCLUSIONS Our results suggest that 12 months of rhGH treatment at the lowest doses so far used normalizes bone metabolism and cortical bone density, and Improves trabecular bone density without causing adverse events.
Effect of fenfluramine on episodic ACTH and cortisol secretion
Authors: Schürmeyer Thomas H. , Brademann Götz , von zur Mühlen Alexander
Published: October 2006

OBJECTIVE The central serotoninergic system is known to modulate the activity of the hypothalamic‐pituitary‐adrenal axis, but the effect of fenfluramine, a serotonin reuptake inhibitor, on ACTH and cortisol secretion is not well understood. We have therefore evaluated its effects on the hypothalamic‐pituitary‐adrenal axis in healthy controls.

DESIGN Episodic secretion of ACTH and cortisol was Investigated in 6 healthy volunteers under basal conditions and again during treatment with 20 and 60 mg fenfluramine given orally every 8 hours. On all occasions blood samples were obtained at 10‐minute Intervals for 24 hours and the mode of hormone secretion was analysed by three different methods (PULSAR, CLUSTER, DESADE). In addition ACTH and cortisol responses to CRH were tested at the end of the sampling period.

RESULTS At the lower dose fenfluramine had no effect on ACTH and cortisol secretion. At the higher dose a significant increase of mean plasma ACTH (+ 85%) and cortisol (+129%) levels as well as of urinary free cortisol secretion (+44%) was observed. Fenfluramine did not modulate the frequency, but increased the amplitudes of ACTH and cortisol secretory episodes. ACTH and cortisol responses to CRH injection remained unchanged. Maximum plasma levels of d‐fenfluramine and d‐nortenfluramine were documented 2–4 hours after the ingestlon of the drug.

CONCLUSION Fenfluramine stimulates the activity of the hypothalamic‐pituitary‐adrenal axis at a suprapituitary level by modulating the amplitude of ACTH and cortisol secretory bursts.
Access to stroke care units in Australian public hospitals: facts and temporal progress
Authors: Cadilhac D. A. , Lalor E. E. , Pearce D. C. , Levi C. R. , Donnan G. A.
Published: October 2006

Background: There is level I evidence that management of stroke patients in stroke units (SU) improves outcomes (death and institutionalization) by approximately 20%. In Australia, there is uncertainty as to the proportion of incident cases that have access to SU. Recent national and State‐based policy initiatives to increase access to SU have been taken. However, objective evidence related to SU implementation progress is lacking. The aims of the study were (i) to determine the number of SU in Australian acute public hospitals in 2004, (ii) to describe hospitals according to national SU policy criteria and (iii) to compare results to the 1999 survey to track progress.

Methods: The method used in the study was a cross‐sectional, postal survey technique. The participants were clinical representatives considered appropriate to describe stroke care within survey hospitals.

Results: The outcome of the study was presence of a SU according to an accepted definition. Response rate was 261/301 (87%). Sixty‐one sites (23%) had either a SU and/or a dedicated stroke team. Fifty sites claimed to have a SU (19%). New South Wales with 23 had the most number of SU. Based on policy criteria, up to 64 sites could have a SU. In 1999, there were 35 public hospitals with a SU.

Conclusion: Access to SU in Australian public hospitals remains low compared with other countries (Sweden, 70%). Implementation strategies supported by appropriate health policy to improve access are needed.