bluuebunny/crossref_metadata_2025 huggingface dataset:
A new pyrethroid‐type ester with strong knockdown activity
Authors: Hirano Masachika , Itaya Nobushige , Ohno Isao , Fujita Yoshio , Yoshioka Hirosuke
Published: November 2006

Thirteen pyrethroid‐type esters of substituted 1(or 3)‐hydroxymethylimidazolidine‐2, 4‐dione were synthesised and their knockdown activities against houseflies, mosquitoes and cockroaches were examined. Knockdown activities of 2,4‐dioxo‐1‐prop‐2‐ynylimidazolidin‐3‐ylmethyl esters in oil solutions were higher than those of known knockdown pyrethroids; three of the compounds also possessed strong knockdown and flushing‐out activities against cockroaches.
Evaluation of chemical fungicides for control of onion white rot
Authors: Utkhede Rajeshwar S. , Rahe James E.
Published: November 2006

Nine chemicals in 1976 and six in 1977 were evaluated in a five × five simple lattice design for control of Sclerotium cepivorum Berk., the causal agent of white rot of onions. The trial was conducted on organic muck soil in Burnaby, British Columbia, with uniform high levels of added (1976) or natural (1977) inoculum. The percentage of white rot infection, weight of healthy bulbs harvested and percentage of emergence were measured. There were significant differences, according to treatment, in the percentage of white rot infection of onion at harvest. Two chemicals, vinclozolin and iprodione, provided promising results as broadcast treatments on organic muck soils. A comparison of the results, in relation to differences in the distribution of inoculuin between the 1976 and 1977 trials, suggested that the major point of control may have been against mycelial growth through soil from sclerotia, remote to onion seedlings and/or from infected plants to healthy plants.
Structure—activity relationships for some organotin molluscicides
Authors: Smith Peter J. , Crowe Alan J. , Das V. G. Kumar , Duncan John
Published: November 2006

Bioassay data are reported for 12 organotin compounds, R3SnX, against the adult snail, Biomphalaria glabrata, an intermediate host of schistosomiasis. The relationship between the molluscicidal activity and the nature of the R and X groups in the organotin compounds is discussed, as well as the possible mode of toxic action of these compounds.
The efficiency of methanol for the extraction of some herbicide residues from soil
Authors: Cotterill Edward G.
Published: November 2006

Methanol was more efficient than solvent systems based on acetonitrile or chloroform for the extraction of a number of weathered herbicide residues from soil. The presence of water in the soil improved recovery. Methanolic extracts, on examination by gas‐liquid chromatography, also gave lower background levels than the extracts with other solvents.
Further studies on amitraz as a veterinary acaricide
Authors: Harrison Ian R. , Palmer Bryan H.
Published: November 2006

Recent research on the control of animal ectoparasites with amitraz is summarised and reference made to its expellent action. Tickicides are an essential requirement for the rearing of cattle in tropical and sub‐tropical regions. The use of amitraz in these areas is well documented. More recently advantage has been taken of its broad acaricidal and insecticidal spectrum to develop the compound for use against lice, keds and, in particular, mites parasitic on farm animals. The outstanding miticidal activity of amitraz has been shown to extend to demodectic mange on dogs. Field trials in Central Europe and the Mediterranean region are used to illustrate the problem of animal pest control within the limits imposed by established farm practices. Finally, mention is made of some attempts to utilise the pesticidal properties of amitraz in less conventional ways, including pasture spraying for the control of ticks.
Kinetics of chemical degradation of organophosphorus pesticides; hydrolysis of chlorpyrifos and chlorpyrifos‐methyl in the presence of copper(II)
Authors: Blanchet Pierre‐F. , St‐George Augustin
Published: November 2006

The kinetics of the hydrolysis reactions of chlorpyrifos‐methyl and chlorpyrifos, in the presence of copper(II), have been measured in buffered aqueous solutions. For each reaction, a rate law of the type ‐d[pesticides]/dt= k2[pesticides][Cu2+] was observed. As the concentration of copper(II) increased, a corresponding increase in the rate of hydrolysis was observed until the concentration of copper(II) reached about 1.0 × 10−2M. At this point, the rate of hydrolysis became independent of the concentration of copper(II) in both reactions. Using the experimental data, a mechanism for each reaction is proposed, in which the copper(II) ion forms a six‐membered ring complex with the nitrogen in the ring structure and the sulphur of the phosphorothioate moiety. The rate of hydrolysis increased with increasing pH. At higher pH values, precipitation of Cu2+ was observed and general base‐hydrolysis reactions became more and more important. The differences in the rate constant observed is explained using the inductive effect theory of the alkyl group.
The mode of action of S‐benzyl O, O‐di‐isoproyl phosphorothiaote and of dicloran on aspergillus nidulans
Authors: Craig Gordon D. , Peberdy John F.
Published: November 2006

S‐Benzyl O, O‐di‐isopropyl phosphorothoiate (IBP) and dicloran inhibit spore germination and mycelial growth in Aspergillus nidulans. The physiological and biochemical effects of both fungicides were studied at their Ec50 values (EC50 is the concentration that inhibits mycelial growth by 50%). IBP inhibited chitin synthase activity in vivo and in vitro and this appeared to be the primary mode of action, although it also caused a slight decrease in total lipid synthesis. Dicloran caused an increase in nucleic acid synthesis, particularly RNA synthesis, but a decrease in total lipid biosynthesis.
Herbicide residues in waste waters from ricefields
Authors: Cabras Paolo , Diana Paolo , Meloni Marco , Pirisi Filippo M. , Pirisi Renzo
Published: November 2006

The herbicides bentazone, 2,4‐D, MCPA, propanil, molinate, and tiocarbazil, and the insecticide phenthoate, were applied to ricefields in Sardinia at rates equivalent to maximum aqueous concentrations of 0.4‐2.8 mg kg−1, assuming the water to be 20 cm deep. Their concentrations in water were measured by high‐performance liquid chromatography. Residues in 162 water samples, collected from 16 ricefields 1, 4, 7, 10, 12, 18, 21 and 120 days after the last spraying, were all below the limit of determination (0.03 mg kg−1). Residues in 40 water samples taken from five drainage canals were also less than 0.03 mg kg−1.
Fungicidal activity of substituted quinoxalines
Authors: Carter Geoffrey A. , Clark Terence , James Carolyn S. , Loeffler R. S. Thomas
Published: November 2006

Twenty substituted quinoxalines based on the structure of 6 (or 7)‐methyl‐3‐phenyl‐1, 2‐dihydroquinoxalin‐2‐one, a fungicidally active photodegradation product of quinomethionate, were synthesised. Eleven of these compounds had ED50 values, as protectant sprays against Podosphaera leucotricha, of 0.1 mmol or less; these compounds had an aromatic substituent at the 3‐position of the quinoxaline ring. They were less active as protectant leaf dips against Erysiphe graminis f. sp. hordei than against Podosphaera leucotricha; none showed any systemic activity as a soil‐applied treatment against Podosphaera leucotricha. One compound was more active than quinomethionate as an eradicant spray. In spore germination tests on fungi from different taxonomic groups, the quinoxaline derivatives were active against only one basidiomycete (Uromyces fabae), whereas quinomethionate showed a broad spectrum of activity. The possible significance of this difference in spectrum of activity with respect to the mode of action is discussed.
Action of bioresmethrin on the corpus cardiacum of Locusta migratoria
Authors: Singh Gur Jai Pal , Orchard Ian
Published: November 2006

The action of the pyrethroid insecticide bioresmethrin on the corpus cardiacum (CC) has been studied in Locusta migratoria. Bioresmethrin increased the spontaneous electrical activity recorded from both the glandular and storage lobes, and induced repetitive discharge in these lobes in response to single electrical stimulation of the nervus corpus cardiacum II (NCC II) and NCC I, respectively. Incubation of the isolated CC in low concentrations of bioresmethrin (0.1‐1.0 μmol) induced the release of bioassayable hyperlipaemic hormone. Injection of bioresmethrin into locusts was found to induce an elevation in the haemolymph lipid at a stage when there was no overt symptom of poisoning. It is concluded that bioresmethrin may act directly on the CC of locusts to modulate electrical activity and induce the release of hormones. The effects may precede overt symptoms of poisoning.
Pyridazinones as bioregulators in crop protection
Authors: Rittig Falk R. , Becker Rainer , Bleiholder Hermann , Feichtmayr Franz , Haedicke Erich , John Judith B. St.
Published: November 2006

Substituted pyridazinones induced specific decreases in the linolenic acid content accompanied by increases in the linoleic acid content of plant membranes. The ratio of linoleic acid to linolenic acid was used to establish structure‐activity correlations for a series of about 50 different substituted pyridazinones. The most active compound found was 4‐chloro‐5‐dimethylamino‐2‐phenylpyridazin‐3‐one. X‐ray structural analysis of this compound yielded three types of crystals differing in their molecular parameters. Application of computerised cluster analysis confirmed the specific biological activity of selected groups of compounds. Electron‐density calculations yielded substituents with specific activity on the linoleic acid/linolenic acid ratio. Correlation of this ratio, produced by different substituted pyridazinones, can be used to search for potentially more active compounds. Treatment of plants, moulds and insects with pyridazinones led to interesting results of importance to agriculture, and confirmed the bioregulator activity of some of these compounds.
Insect hormones and growth regulators
Authors: Jennings Richard C.
Published: November 2006

The endocrine system that controls development and reproduction in insects has many unique features that could provide targets for insecticides with novel modes of action. Such insecticides, which act by disrupting the growth and development, are often called insect growth regulators. Three components of the endocrine system are discussed in this context, and an example of the specific chemical disruption of one of them, which could form the basis for the development of such insecticides, is described.
The relationship of metabolism studies to the modes of action of herbicides
Authors: Kirkwood Ralph C.
Published: November 2006

Metabolism studies are necessary in the understanding of the mode of action of herbicides, their loss of activity and their selectivity. Molecular change of a herbicide may involve photochemical degradation, and non‐enzymic or enzymic reactions that normally inactivate, but in some cases activate, a compound. Molecular change resulting in activation is discussed with regard to the (2,4‐dichlorophenoxy)‐alkanoic acids, the pyridines paraquat and diquat, the anilides benzoylprop‐ethyl and flamprop‐methyl, and the thiocarbamates. Inactivation due to metabolism is reviewed with regard to herbicides applied to soil and foliage. Of the soil‐applied herbicides, the 1,3,5‐triazines and the nitrile dichlobenil are exemplified as cases in which selectivity may be due largely to interspecific differences in metabolism. Of the foliage‐applied translocated compounds, the metabolism of the phenoxyalkanoic acid herbicides has been extensively investigated and may involve conjugation, side‐chain degradation or extension, ring hydroxylation and protein binding. The mode of action of glyphosate, asulam, dalapon and aminotriazole in perennial weeds is discussed with particular reference to their metabolism.
Synthesis and juvenile hormone activities of some new ether derivatives of hydroquinone
Authors: Massardo Pietro , Bettarini Franco , Piccardi Paolo , Longoni Angelo
Published: November 2006

A new class of compounds, derived from hydroquinones, has been synthesised and bioassayed for juvenile hormone activity on yellow mealworm (Tenebrio molitor), confused flour beetle (Tribolium confusum), and mediterranean flour moth (Anagasta kuehniella). Structure‐biological activity relationships of the most significant products are tabulated and discussed. Two of the new compounds, 1, 4‐bis(5‐chloropent‐4‐ynyloxy) benzene (I) and 1‐(5‐chloropent‐4‐ynyloxy)‐4‐phenoxybenzene (II), showed outstanding activity in morphogenetic assay with T. molitor, and good field persistence. Product II is of particular interest for the control of various Homopteran species, mosquitoes, stored product pests and fire ants.
The use of small enclosures to assess the toxic effects of cypermethrin on fish under field conditions
Authors: Shires Stephen W.
Published: November 2006

An emulsion concentrate formulation of cypermethrin (‘Ripcord’) was applied at seven different dose rates (between 5 and 500 g a. i. ha−1) to the water surface of 1‐m3 stainless steel enclosures, located in a small outdoor pond, to which were introduced small rainbow trout and common carp. A range of water quality parameters were monitored frequently in all of the enclosures and in the open pond. At daily intervals, the concentration of cypermethrin was determined in water samples, collected from the enclosures treated with 5, 50 and 500 g a. i. ha‐−1. Two further water samples were collected from these enclosures, and their toxicity was assessed by bioassay, using Gammarus pulex as the test organism. The experiment was terminated 96 h after application, when all the fish were removed and examined for mortality or adverse toxic effects. Throughout the study, the water quality parameters in all the enclosures remained similar to those recorded in the open pond. Cypermethrin residues, in the enclosures treated with 5 and 50 g a. i. ha−1, attained peak concentrations 24 h after application, and thereafter declined to about 50% of this level. Maximum cypermethrin concentrations were not attained until about 72 h after application in the enclosure treated with 500 g a. i. ha−1. Highly consistent responses, closely correlated with the applied dose rates, were obtained with G. pulex and both species of fish. Rainbow trout appeared to be about three times more susceptible to cyper‐methrin than common carp, with calculated LD50 values of 92 and 300 g a. i. ha−1, respectively. It is therefore most unlikely that fish mortality would result from the use of cypermethrin in normal agricultural practice.
Development of resistance and cross‐resistance in fenvalerate and deltamethrin selected strains of Spodoptera littoralis (Boisd.)
Authors: Riskallah Medhat R. , Abd‐Elghafar Samir F. , Abo‐Elghar Mohamed R. , Nassar Moustafa E.
Published: November 2006

Resistances of 33‐ and 27‐fold to the pyrethroids fenvalerate and deltamethrin, respectively, have been induced in larvae of the Egyptian cotton leafworm Spodoptera littoralis (Boisd.) by selection of two subcolonies of a field population in the laboratory. Selected strains showed relatively high levels of resistance (11‐ to 36‐fold) to all the tested pyrethroids, moderate levels of cross‐resistance (3‐ to 13‐fold) to DDT and the carbamate aminocarb, and a slight increase in tolerance levels to endrin and lindane. The pyrethroid‐resistant strains, by contrast, manifested no cross‐resistance to the organophosphorus compounds that were tested. Moreover, a negative crossresistance was observed in the pyrethroid‐resistant strains to dicrotophos, methamidophos and the carbamate methomyl.
The use of dimensional analysis in a study of drop retention on barley
Authors: Lake John R. , Marchant John A.
Published: November 2006

Dimensional analysis was used to simplify an experimental investigation of the relationship between the variables thought to be involved in the retention process. Equipment was developed for applying drops of known size at a range of velocities to glasshouse‐grown barley leaves. This enabled experiments to be carried out to determine the velocity at which drops of a given size were retained on a leaf. Expressions were developed relating the groups of variables thought to affect retention. From these expressions, a graph was produced which can be used to predict the retention behaviour over the experimental range investigated. For example, if drops (100‐400 μm diameter) of water containing a surfactant are applied at their terminal velocitres to the leaves, it is predicted that (a) smaller drops will be retained better than larger drops, and (b) larger drops will be retained if the surface tension of the spray liquid is reduced.
Studies of plant cuticle and spray droplet interactions: A fresh approach
Authors: Baker Edward A. , Hunt Grace M. , Stevens Peter J. G.
Published: November 2006

The effects of cuticular properties on the impaction and redistribution of aqueous and oil solutions, emulsions and wettable powders were studied using a microapplicator, which dispensed monosize droplets (50‐400 μm), and a range of techniques including scanning electron microscopy, X‐ray analysis and microautoradiography. Lateral and transcuticular movement of active ingredients was monitored by stripping the outermost wax layers and adhering deposits with cellulose acetate films applied as a spray from an acetone solution. Spread factors, determined using fluorescent markers and a reflectance microscope, varied extensively. Oil formulations spread rapidly through layers of crystalline wax whereas aqueous solutions distributed most readily over smooth surfaces. An X‐ray analyser attachment to the scanning electron microscope proved particularly useful for investigating the complex interactions occurring between plant surfaces and diluted e. c. and w. p. formulations. Kamaps and elemental spectra confirmed that lipophilic materials partitioned preferentially into the organic phase which separated as a zone at the outer edge of the droplet residue, whereas water‐soluble compounds concentrated in the central region.
The persistence of spray droplets above two vegetation canopies
Authors: Symmons Philip M. , Dubs Andreas
Published: November 2006

Droplets were released from an ‘instantaneous line source’ perpendicular to the wind at heights of 4 and 7 m above the ground. Droplets were collected by rotating samplers at three heights; sets of samplers were positioned in a line parallel to the wind, downwind of the line source. Trials were carried out in moderately unstable conditions during the day, and under stable conditions shortly after dark, both over short rough stubble and over mature cotton. A substantial proportion of the small droplets were found to travel as far as 500 m over cotton; over grass, few of even the smallest droplets were collected 250 and 500 m downwind of the line source. Collection at the distant samplers was on average slightly, but not significantly, more when the spray was released at the greater height.
Anion‐controlled Syntheses and Crystal Structures of a Pair of Novel Azide‐bridged Copper(II) Complexes Constructed from 4‐Chloro‐2‐[(2‐dimethylaminoethylimino)methyl]phenol
Authors: You Zhong‐Lu , Jiao Qing‐Zhu , Niu Shu‐Yun , Chi Jing‐Yun
Published: November 2006

A pair of novel azide‐bridged polynuclear copper(II) complexes, [CuL(μ1,1‐N3)]n (1) and [Cu4L2(CH3COO)2(μ1,1‐N3)4] (2) (L = 4‐chloro‐2‐[(2‐dimethylaminoethylimino)methyl]phenolate), have been obtained from the same Schiff base ligand and an identical synthetic procedure using anions of the metal salts as the only independent variable. Complex 1 was synthesized using copper(II) nitrate, while complex 2 was synthesized using the copper(II) acetate as the salt. Both of the complexes show novel supramolecular structures in their crystals as elucidated by X‐ray analyses. The polynuclear complex 1 contains [CuL(μ1,1‐N3)]n units as the building blocks, crystallizes in the Pbca space group. The tetra‐nuclear complex 2 contains [Cu4L2(CH3COO)2(μ1,1‐N3)4] units as the building blocks, crystallizes in the $P{\bar 1}$ space group.
Syntheses, Characterization and Crystal Structures of Three Structurally Similar Dinuclear Schiff Base Cadmium(II) Complexes with Bridging Azide or Thiocyanate Ligands
Authors: You Zhong‐Lu , Jiao Qing‐Zhu , Niu Shu‐Yun , Chi Jing‐Yun
Published: November 2006

Three novel Schiff base cadmium(II) complexes, derived from the end‐on (μ‐1,1‐N3) azide or end‐to‐end (μ‐1,3‐NCS) thio cyanate bridges and similar tridentate Schiff base ligands, have been synthesized under similar synthetic procedures and their crystal structures determined by X‐ray diffraction methods. They are the dinuclear double end‐on azide‐bridged [Cd2(L1)2(N3)2(μ‐1,1‐N3)2] (1), the dinuclear double end‐on azide‐bridged [Cd2(L2)2(N3)2(μ‐1,1‐N3)2] (2), and the dinuclear double end‐to‐end thiocyanate‐bridged [Cd2(L3)2(NCS)2(μ1,3‐NCS)2] (3), where L1, L2 and L3 are three similar tridentate Schiff bases obtained by condensation of 2‐pyridylaldehyde with N,N‐diethylethane‐1,2‐diamine, of 2‐pyridylaldehyde with N‐isopropylethane‐1,2‐diamine, and of 2‐pyridylaldehyde with N,N‐dimethylpropane‐1,3‐diamine, respectively. Each cadmium(II) centre in the complexes is in a distorted octahedral coordination. There is a crystallographic inversion centre in each of the complexes. The similar small ligands used as the secondary ligands in the preparation of the cadmium(II) complexes with similar Schiff bases can result in similar structures.
Involvement of phospholipid molecular species in controlling structural order of vertebrate brain synaptic membranes during thermal evolution
Authors: Kitajka K. , Buda Cs. , Fodor E. , Halver J. E. , Farkas T.
Published: November 2006

Fluorescence anisotropy parameter of [p‐(6‐phenyl)‐1,3,5‐hexatrienyl]phenyl‐propionic acid (DPH‐PA) and 1‐(4‐trimethylammoniumphenyl)‐6‐phenyl‐1,3,5‐hexatriene (TMA‐DPH) embedded in synaptic plasma membranes prepared from brains of cold (5°C) and warm (22°C) adapted fish (Cyprinus carpio L.), rat (Rattus norvegicus) and bird (Branta canadensis), was studied. Fatty acid composition of total lipids as well as molecular species composition of diacyl phosphatidylcholines and phosphatidylethanolamines was also determined. The amount of long‐chain polyunsaturated fatty acids decreased with increasing body temperature. There was a nearcomplete compensation of membrane structural order for environmental/body tempeature over the evolutionary scale as seen by DPH‐PA. Using TMA‐DPH, the compensation was partial with rat and bird. Since DPH‐PA and TMA‐DPH differ in their charges, it is proposed, that the former reported membrane regions rich in cationic or zwitterionic (neutral) phospholipids and the latter, membrane regions rich in negatively charged phospholipids in the synaptic plasma membranes. Many different molecular species (20–25) of diacyl phosphatidylcholines and diacyl phosphatidylethanolamines were identified. The level of 16:0/22:6 phosphatidylcholine decreased while disaturated phosphatidylcholines increased with increase of environmental/body temperature from the fish through the bird. Level of 1‐monoenoic 2‐polyenoic phosphatidylethanolamines also decreased with an increase in environmental/body temperature. Experiments using vesicles made of mixed synthetic phosphatidylcholine vesicles (16:0/16:0, 16:0/18:1, 16:0/22:6 in various proportions) showed that increase in disaturated phosphatidylcholine species does not explain the observed complete adjustment of membrane structural order in synaptic plasma membranes. Change in level of 1‐monoenoic, 2‐polyenoic phosphatidylethanolamines might be one of the factors involved in controlling the biophysical properties of the membrane according to the temperature.
The effects of lidocaine and hypoxia on phospholipid biosynthesis in the isolated hamster heart
Authors: Wong Jason T. , Man Ricky Y. K. , Choy Patrick C.
Published: November 2006

In this study, the effects of lidocaine and hypoxia on the biosynthesis of phospholipids in the hamster heart were examined. hamster hearts were perfused with [1,3‐3H]glycerol under normal and hypoxic conditions, and in the absence or presence of 0.5 mg/mL lidocaine. After perfusion, the radioactivity incorporated into the various phospholipid fractions was determined. With the exception of phosphatidylcholine, the synthesis of phospholipids was generally stimulated by lidocaine perfusion. In contrast, hypoxia caused a general decrease in phospholipid biosynthesis which was partially restored by lidocaine. ATP and CTP levels were severely reduced under hypoxic conditions, but their levels were not restored by lidocaine treatment. The activities of enzymes for phospholipid synthesis were determined under the various perfusion conditions. The activity of phosphatidic acid phosphatase was elevated by lidocaine and decreased by hypoxic treatment. The activity of CTP:phosphatidic acid cytidylyltransferase was increased under hypoxia, with or without lidocaine. Despite the reduction in phosphatidylcholine biosynthesis, no change in the activity of cytidine diphosphocholine (CDPcholine): diacylglycerol cholinephosphotransferase was detected following lidocaine or hypoxic perfusion. However, enzyme activity was inhibited by the presence of lidocaine in the assay mixture. Our results indicate that the reduction in phospholipid biosynthesis under hypoxic conditions was caused mainly by diminishing high‐energy nucleotide levels. The enhancement of phospholipid biosynthesis by lidocaine appeared to be mediated in part by modulation of enzyme activities.
Difficulties in the assay of phosphatidate phosphohydrolase activity. Influence of ionic strength, detergent, and selection of substrate
Authors: Stark Margareta , Humble Elisabet
Published: November 2006

In the present paper, problems in connection with assay of the activity of magnesium‐dependent rat liver phosphatidate phosphohydrolase (PAP) are discussed. PAP activity is usually measured by following the production of diacylglycerol or inorganic phosphate from the substrate phosphatidate. These two methods may give widely different results due to a number of factors that may affect the assay. One such factor is the composition of the substrate. Higher apparent enzyme activity was observed with dioleoyl‐phosphatidate than with dipalmitoyl‐phosphatidate. This substrate‐dependent difference in apparent PAP activity was 2‐2.5‐fold in the absence and 10‐fold in the presence of Triton X‐100, respectively. Triton X‐100 reduced the activity as measured with the dipalmitoyl‐phosphatidate substrate. In contrast, the activity of PAP as measured with dioleoyl‐phosphatidate was stimulated by Triton X‐100 The stimulatory effect of Triton was reduced or abolished when the ionic strength in the assay mixture was increased. Assays based on32P‐labeled substrate are rapid and sensitive. It is shown here that33P can be used as an alternative. This radionuclide has a longer half‐life and also emits particles with lower energy, thus posing less potential health hazards for the user.
Effect of dietary vitamin E levels on fatty acid profiles and nonenzymatic lipid peroxidation in the guinea pig liver
Authors: Barja G. , Cadenas S. , Rojas C. , Pérez‐Campo R. , López‐Torres M. , Prat J. , Pamplona R.
Published: November 2006

Guinea pigs were fed for five weeks with three diets containing different levels of vitamin E: LOW (but nondeficient, 15 mg of vitamin E/kg diet), MEDIUM (150 mg/kg diet), and HIGH (1,500 mg/kg diet). Dietary vitamin E supplementation did not change oxidative stress indicators in the hydrophilic compartment but increased liver α‐tocopherol in a dose‐dependent way and strongly decreased sensitivity to nonenzymaticin vitro liver lipid peroxidation. This last effect was already observed in group MEDIUM, and no further decrease inin vitro lipid peroxidation occurred from group MEDIUM to group HIGH. The protective effect of vitamin E againstin vitro lipid peroxidation was observed even though an optimum dietary concentration of vitamin C for this animal model was present in the three different vitamin E diets. Both HIGH and LOW vitamin E decreased percentage fatty acid unsaturation in all phospholipid fractions from membrane origin in relation to group MEDIUM. The results, together with previous information, show that both vitamin E and vitamin C at intermediate concentrations are needed for optimal protection against lipid peroxidation and loss of fatty acid unsaturation even in normal nonstressful conditions. These protective concentrations are higher than those needed to avoid deficiency syndromes.
Enhancement by ganglioside GT1b of annexin I phosphorylation in bovine mammary gland in the presence of phosphatidylserine and Ca2+
Authors: Katoh Norio , Miyamoto Toru
Published: November 2006

Ganglioside GT1b and, to a lesser extent, GD3, enhanced phosphorylation of a 36 kDa protein (the substrate of protein kinase C) in the particulate fraction from bovine mammary gland. Sialic acids, asialogangliosides, and GM3 were without effect, and GD1a conversely inhibited phosphorylation of the 36 kDa protein. The enhanced phosphorylation by GT1b required the simultaneous presence of phosphatidylserine (PS) and Ca2+. The 36 kDa protein reacted with anti‐annexin I in Western blot analysis. Addition of purified annexin I to the reaction mixture containing the particulate fraction increased the extent of phosphorylated 36 kDa protein, and the phosphorylation was further enhanced by GT1b. The enhanced phosphorylation of annexin I by GT1b was also dependent on PS and Ca2+. When annexin I was phosphorylated by purified protein kinase C, GT1b inhibited the annexin I phosphorylation. Addition of epidermal growth factor or insulin to the particulate fraction had little effect on the enhancement. These results suggest that an enzyme or enzymes other than protein kinase C, epidermal growth factor receptor kinase, or insulin receptor kinase is responsible for the GT1b‐ and GD3‐enhanced phosphorylation of annexin I in the presence of PS and Ca2+.
Hydroperoxides of erythrocyte phospholipid molecular species formed by lipoxygenase correlate with α‐tocopherol levels
Authors: Therond Patrice , Couturier Martine , Demelier Jean François , Lemonnier Frédérique
Published: November 2006

The hydroperoxides corresponding to the main molecular species of phosphatidylcholine (PC) and phosphatidylethanolamine (PE) where determined after lipoxygenase treatment of erythrocyte membranes from healthy children. This work was a preliminary study prior to applying this analytical procedure to erythrocyte membranes from children with diseases associated with vitamin E deficiency. The total molecular species corresponding to 20:4 and 22:6 associated with 16:0 and 18:0 were significantly higher in PE (26.94±4.70 nmol/mg protein) than in PC (20.14±6.70 nmol/mg protein); these concentrations represented 63% of the total molecular species in PE and 22% in PC. However, the concentrations of hydroperoxides produced from these polyunsaturated fatty acid molecular species were in the same order of magnitude in PC (3.98±1.56 nmol/mg protein) and in PE (3.61±1.63 nmol/mg protein). In contrast, the molecular species concentrations containing two double bounds, such as 16:0/18:2 and 18:0/18:2 and their corresponding hydroperoxides, were clearly more elevated in PC than in PE. There was a positive relationship between the concentrations of α‐tocopherol and each hydroperoxide of PC and PE, and this association was particularly strong in PE (P≤0.0001). These results suggest that α‐tocopherol exerts a stabilizing effect toward hydroperoxides, limiting their further degradation into peroxyl radicals. The protective effect of α‐tocopherol could be more effective in PE because more polyunsaturated fatty acids were present.
n‐3 Polyunsaturated fatty acid‐induced changes in the molecular species composition of diradylglycerol in murine peritoneal macrophages remain stable during incubationex vivo
Authors: Marignani Paola A. , Sebaldt Rolf J.
Published: November 2006

Three‐ to four‐week‐old C57BL/6 mice were maintained for four weeks on diets in which the 10% lipid component was the ethyl esters of either corn oil or n‐3 polyunsaturated fatty acids (n‐3 PUFA). Incubation of macrophagesex vivo for 14 h, a normal incubation time used for macrophage studies, in the absence of fetal calf serum, did not diminish the extent of incorporation of 20∶5n‐3 (eicosapentaenoic acid) and 22∶6n‐3 (docosahexaenoic acid) moieties into membrane phospholipids and into diradylglycerol (DG) relative to that after a very abbreviated incubation time. We conclude that studies examining the effects of dietary n‐3 PUFA on DG formation and related physiological effects in macrophages can be performed after a normalex vivo incubation of at least 14 h without experiencing a significant loss of incorporated n‐3 PUFA.
Phosphatidate phosphatases of mammals, yeast, and higher plants
Authors: Kocsis Michael G. , Weselake Randall J.
Published: November 2006

Phosphatidate phosphatase (EC 3.1.3.4) catalyzes the hydrolysis of phosphatidate to yieldsn‐1,2‐diacylglycerol and inorganic phosphate. In mammalian systems, forms of phosphatidate phosphatase involved in glycerolipid synthesis and signal transduction have been identified. Forms of the enzyme involved in signal transduction have been purified and partially characterized. In yeast, phosphatidate phosphatases associated with the endoplasmic reticulum and mitochondria have also been purified and partially characterized. Information on phosphatidate phosphatases from mammals and yeast is useful in characterizing the enzyme from plant systems. This review examines progress on the characterization of phosphatidate phosphatases from mammals, yeast, and higher plants. The purification and characterization of the phosphatidate phosphatase involved in glycerolipid synthesis in developing oilseeds may lead to the identification of the encoding gene. Increasing our understanding of the enzymes of lipid synthesis in developing seeds will aid in the development of biotechnological strategies for seed oil modification.
Sterols of the phylum Zygomycota: Phylogenetic implications
Authors: Weete J. D. , Gandhi S. R.
Published: November 2006

The sterol composition of 42 fungal species representing six of the eight orders of the Zygomycota was determined using gas‐liquid chromatography‐mass spectrometry to assess whether the distribution of major sterols in this phylum has taxonomic or phylogenetic relevance. Ergosterol, 22‐dihydroergosterol, 24‐methyl cholesterol, cholesterol, and desmosterol were detected as the major sterols among the species studied. Ergosterol was the major sterol of the Dimargaritales, Zoopagales, and 13 of the 14 Mucorales families included in this study. Desmosterol appeared to be the characteristic sterol of the Mortierellaceae (Mucorales). 24‐Methyl cholesterol was the major sterol of the Entomophthorales genera Entomophthora, Conidiobolus and Basidiobolus, but cholesterol was the sole sterol detected in Delacroixia coronatus. The Kickxellales species analyzed in this study were characterized by 22‐dihydroergosterol as the major sterol. These results suggest that certain orders of the Zygomycota may be distinguished on the basis of major sterol. Also, if sterol structure has phylogenetic implications, then orders might be arranged in the order Kickxellales (C28Δ5,7) → Dimargaritales, Zoopagales and Mucorales (C28Δ5,7,22) on the basis of evolution of the predominant and presumably most competent sterol, ergosterol. Although the Entomophthorales would be expected to be more primitive than the above orders based on the predominance of C28Δ5,, it is not apparent from these data that members of the Zygomycota with ergosterol or its precursors as major sterols evolved from this taxon or the Chytridiomycota.
New Approaches to Fertility Awareness‐Based Methods: Incorporating the Standard Days and TwoDay Methods into Practice
Authors: Germano Elaine , Jennings Victoria
Published: November 2006

Helping clients select and use appropriate family planning methods is a basic component of midwifery care. Many women prefer nonhormonal, nondevice methods, and may be interested in methods that involve understanding their natural fertility. Two new fertility awareness– based methods, the Standard Days Method and the TwoDay Method, meet the need for effective, easy‐to‐provide, easy‐to‐use approaches. The Standard Days Method is appropriate for women with most menstrual cycles between 26 and 32 days long. Women using this method are taught to avoid unprotected intercourse on potentially fertile days 8 through 19 of their cycles to prevent pregnancy. They use CycleBeads, a color‐coded string of beads representing the menstrual cycle, to monitor their cycle days and cycle lengths. The Standard Days Method is more than 95% effective with correct use. The TwoDay Method is based on the presence or absence of cervical secretions to identify fertile days. To use this method, women are taught to note everyday whether they have secretions. If they had secretions on the current day or the previous day, they consider themselves fertile. The TwoDay Method is 96% effective with correct use. Both methods fit well into midwifery practice.
Expression of TEL-JAK2 in primary human hematopoietic cells drives erythropoietin-independent erythropoiesis and induces myelofibrosis
in vivo
Authors: Kennedy J. A. , Barabé F. , Patterson B. J. , Bayani J. , Squire J. A. , Barber D. L. , Dick J. E.
Published: November 2006

Activation of JAK2 by chromosomal translocation or point mutation is a recurrent event in hematopoietic malignancies, including acute leukemias and myeloproliferative disorders. Although the effects of activated JAK2 signaling have been examined in cell lines and murine models, the functional consequences of deregulated JAK2 in the context of human hematopoietic cells are currently unknown. Here we report that expression of TEL-JAK2, a constitutively active variant of the JAK2 kinase, in lineage-depleted human umbilical cord blood cells results in erythropoietin-independent erythroid differentiation
in vitro
and induces the rapid development of myelofibrosis in an
in vivo
NOD/SCID xenotransplantation assay. These studies provide functional evidence that activated JAK2 signaling in primitive human hematopoietic cells is sufficient to drive key processes implicated in the pathophysiology of polycythemia vera and idiopathic myelofibrosis. Furthermore, they describe an
in vivo
model of myelofibrosis initiated with primary cells, highlighting the utility of the NOD/SCID xenotransplant system for the development of experimental models of human hematopoietic malignancies.
Structure of DNA polymerase β with a benzo[
c
]phenanthrene diol epoxide-adducted template exhibits mutagenic features
Authors: Batra Vinod K. , Shock David D. , Prasad Rajendra , Beard William A. , Hou Esther W. , Pedersen Lars C. , Sayer Jane M. , Yagi Haruhiko , Kumar Subodh , Jerina Donald M. , Wilson Samuel H.
Published: November 2006

We have determined the crystal structure of the human base excision repair enzyme DNA polymerase β (Pol β) in complex with a 1-nt gapped DNA substrate containing a template
N
2
-guanine adduct of the tumorigenic (−)-benzo[
c
]phenanthrene 4
R
,3
S
-diol 2
S
,1
R
-epoxide in the gap. Nucleotide insertion opposite this adduct favors incorrect purine nucleotides over the correct dCMP and hence can be mutagenic. The structure reveals that the phenanthrene ring system is stacked with the base pair immediately 3′ to the modified guanine, thereby occluding the normal binding site for the correct incoming nucleoside triphosphate. The modified guanine base is displaced downstream and prevents the polymerase from achieving the catalytically competent closed conformation. The incoming nucleotide binding pocket is distorted, and the adducted deoxyguanosine is in a syn conformation, exposing its Hoogsteen edge, which can hydrogen-bond with dATP or dGTP. In a reconstituted base excision repair system, repair of a deaminated cytosine (i.e., uracil) opposite the adducted guanine was dramatically decreased at the Pol β insertion step, but not blocked. The efficiency of gap-filling dCMP insertion opposite the adduct was diminished by >6 orders of magnitude compared with an unadducted templating guanine. In contrast, significant misinsertion of purine nucleotides (but not dTMP) opposite the adducted guanine was observed. Pol β also misinserts a purine nucleotide opposite the adduct with ungapped DNA and exhibits limited bypass DNA synthesis. These results indicate that Pol β-dependent base excision repair of uracil opposite, or replication through, this bulky DNA adduct can be mutagenic.
Audio‐Vestibular Disturbance in Patients With Behçet's Disease
Authors: Choung Yun‐Hoon , Cho Min Jung , Park Keehyun , Choi Seong Jun , Shin You Ree , Lee Eun‐So
Published: November 2006

Objective: The present study prospectively investigated the frequencies and characteristics of audio‐vestibular disturbance and the results of audiologic and vestibular function tests in patients with Behçet's disease.

Study Design:
A prospective study.

Methods: Seventeen patients with Behçet's disease (mean age 41.2 [30–56] years, 5 males and 12 females), as well as age‐ and sex‐matched healthy controls, were included in this study. All subjects satisfied the diagnostic criteria of the International Study Group for Behçet's Disease. Information on the subjects was obtained through questionnaires. Tests, including those for hearing impairment, tinnitus, ear fullness, and dizziness, pure‐tone audiometry, and vestibular function, were performed.

Results: Auditory symptoms were reported by 7 (41.2%) and dizziness by 14 (82.4%) of the subjects. Sensorineural hearing loss was present in four (23.5%) subjects. One was treated with a cochlear implantation because of bilateral sudden deafness. Spontaneous nystagmus was detected in two (11.8%) subjects. Abnormal findings were noted in 1 (5.9%) in saccadic movement, 5 (29.4%) in the bithermal caloric tests, and 10 (58.9%) in the rotation chair tests. In total, audiologic or vestibular disturbance were noted in 16 (94.1%) of the subjects. However, audio‐vestibular abnormalities were not noted in the healthy controls.

Conclusion: Audio‐vestibular disturbance is not rare in Behçet's disease patients compared with healthy controls. We believe that audio‐vestibular assessment and management may be helpful for the diagnosis and treatment of patients with Behçet's disease.
Association of neuropeptides with Th1/Th2 balance and allergic sensitization in children
Authors: Herberth G. , Daegelmann C. , Weber A. , Röder S. , Giese T. , Krämer U. , Schins R. P. F. , Behrendt H. , Borte M. , Lehmann I. ,   for the LISAplus study group
Published: November 2006

Background
Among neurogenic factors, the neuropeptides have an important regulatory influence on immune system activity and may lead to allergic sensitization.

Objective
The aim of our study was to investigate the relationship of the neuropeptides vasoactive intestinal peptide (VIP), somatostatin (SOM) and substance P (SP) on modulation of Th1/Th2 balance and allergic sensitization in children.

Methods
Within the LISAplus (Life style–Immune system–Allergy) study, blood samples of 321 six‐year‐old children were analysed for concentration of neuropeptides, Th1 and Th2 cytokines, transcription factors for T cell regulation and suppressors of cytokine signalling. In addition, samples were screened for specific IgE against inhalant and food allergens.

Results
Children with high SOM values showed a Th2 polarization and a reduced expression of FOXP3, the marker for regulatory T cells. High (VIP) levels correlated inversely with the expression of T cell transcription factors (Tbet and SOCS3). In contrast, elevated levels of SP were associated with reduced GATA3 and SOCS3 expression and with increased IFN‐γ concentrations. Allergic sensitization was more prevalent in children with higher SOM and VIP concentrations but not associated with SP levels.

Conclusion
Our data reveal an association between neuropeptides and modulatory effects on immune cells in vivo, especially on Th1/Th2 balance with a correlation to allergic sensitization in children. We suggest that elevated SOM and VIP concentrations and the inducing factors should be considered as allergy risk factors.
Gut–Brain Axis: Regulation of Glucose Metabolism
Authors: Heijboer A. C. , Pijl H. , Van den Hoek A. M. , Havekes L. M. , Romijn J. A. , Corssmit E. P. M.
Published: November 2006

Obesity and type II diabetes mellitus have reached epidemic proportions. From this perspective, knowledge about the regulation of satiety and food intake is more important than ever. The gut releases several peptides upon feeding, which affect hypothalamic pathways involved in the regulation of satiety and metabolism. Within the hypothalamus, there are complex interactions between many nuclei of which the arcuate nucleus is considered as one of the most important hypothalamic centres that regulates food intake. The neuropeptides, which are present in the hypothalamus and are involved in regulating food intake, also play a key role in regulating glucose metabolism and energy expenditure. In synchrony with the effects of those neuropeptides, gastrointestinal hormones also affect glucose metabolism and energy expenditure. In this review, the effects of the gastrointestinal hormones ghrelin, cholecystokinin, peptide YY, glucagon‐like peptide, oxyntomodulin and gastric inhibitory polypeptide on glucose and energy metabolism are reviewed. These gut hormones affect glucose metabolism at different levels: by altering food intake and body weight, and thereby insulin sensitivity; by affecting gastric delay and gut motility, and thereby meal‐related fluctuations in glucose levels; by affecting insulin secretion, and thereby plasma glucose levels, and by affecting tissue specific insulin sensitivity of glucose metabolism. These observations point to the notion of a major role of the gut–brain axis in the integrative physiology of whole body fuel metabolism.
Pharmacological approaches towards rationalizing the use of endoparasitic drugs in small animals
Authors: SANCHEZ BRUNI S. F. , JONES D. G. , MCKELLAR Q. A.
Published: November 2006

Parasitic diseases are an important health concern to small animal veterinarians worldwide, and their zoonotic potential is also of relevance to human medicine. The treatment and control of such conditions relies heavily on pharmaceutical intervention using a range of antiparasitic drugs and/or their biologically active metabolites. Broad spectrum agents have been produced, although narrow and even monospecific drugs are used in some situations. Their efficacy may depend on dosage, the target pathogen(s), the host species and/or the site of infection. Optimal use of antiparasitics requires a detailed consideration of the pharmacokinetic and pharmacodynamic properties of the drugs in specific clinical contexts. This review summarizes the present status of knowledge on the metabolism, and physicochemical and pharmacological properties of the major antiparasitic drugs currently used in small animal veterinary practice. In addition, data relevant to therapeutic dosage, efficacy and clinical indication/contraindication, particularly in relation to combination drug therapy, are included.