Equine and Animal Cognition Reference Database -- Query Results

	Equine and Animal Cognition Reference Database Home \| Show All \| Simple Search \| Advanced Search	Login Quick Search: Field: contains: ...
	11-20 of 40 records found matching your query:

Search & Display Options

Select All Deselect All

<< 1 2 3 4 >>

List View

Citations

Details

	Records
	Author	Bayley, P.; Martin, S.; Anson, M.
	Title	Temperature-jump circular dichroism: observation of chiroptical relaxation processes at millisecond time resolution			Type	Journal Article
	Year	1975	Publication	Biochemical and Biophysical Research Communications	Abbreviated Journal	Biochem Biophys Res Commun
	Volume	66	Issue	1	Pages	303-308
	Keywords	*Alcohol Oxidoreductases/metabolism; Animals; Circular Dichroism; Horses; Kinetics; Liver/enzymology; Mathematics; Protein Conformation; Temperature; Time Factors
	Abstract
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language	English	Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0006-291X	ISBN		Medium
	Area		Expedition		Conference
	Notes	PMID:1172440			Approved	no
	Call Number	Equine Behaviour @ team @			Serial	3816
Permanent link to this record



	Author	Haruta, N.; Kitagawa, T.
	Title	Time-resolved UV resonance Raman investigation of protein folding using a rapid mixer: characterization of kinetic folding intermediates of apomyoglobin			Type	Journal Article
	Year	2002	Publication	Biochemistry	Abbreviated Journal	Biochemistry
	Volume	41	Issue	21	Pages	6595-6604
	Keywords	Animals; Apoproteins/chemistry; Circular Dichroism; Holoenzymes/chemistry; Horses; Hydrochloric Acid/chemistry; Hydrogen-Ion Concentration; Imidazoles/chemistry; Kinetics; Models, Molecular; Myoglobin/chemistry; Peptide Fragments/chemistry; Protein Folding; Protein Structure, Secondary; Spectrum Analysis, Raman/methods; Tryptophan/*chemistry; Ultraviolet Rays; Whales
	Abstract	The 244-nm excited transient UV resonance Raman spectra are observed for the refolding intermediates of horse apomyoglobin (h-apoMb) with a newly constructed mixed flow cell system, and the results are interpreted on the basis of the spectra observed for the equilibrium acid unfolding of the same protein. The dead time of mixing, which was determined with the appearance of UV Raman bands of imidazolium upon mixing of imidazole with acid, was 150 micros under the flow rate that was adopted. The pH-jump experiments of h-apoMb from pH 2.2 to 5.6 conducted with this device demonstrated the presence of three folding intermediates. On the basis of the analysis of W3 and W7 bands of Trp7 and Trp14, the first intermediate, formed before 250 micros, involved incorporation of Trp14 into the alpha-helix from a random coil. The frequency shift of the W3 band of Trp14 observed for this process was reproduced with a model peptide of the A helix when it forms the alpha-helix. In the second intermediate, formed around 1 ms after the start of refolding, the surroundings of both Trp7 and Trp14 were significantly hydrophobic, suggesting the formation of the hydrophobic core. In the third intermediate appearing around 3 ms, the hydrophobicity was relaxed to the same level as that of the pH 4 equilibrium intermediate, which was investigated in detail with the stationary state technique. The change from the third intermediate to the native state needs more time than 40 ms, while the appearance of the native spectrum after the mixing of the same solutions was confirmed separately.
	Address	School of Mathematical and Physical Sciences, The Graduate University for Advanced Studies, Myodaiji, Okazaki 444-8585, Japan
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language	English	Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0006-2960	ISBN		Medium
	Area		Expedition		Conference
	Notes	PMID:12022863			Approved	no
	Call Number	Equine Behaviour @ team @			Serial	3785
Permanent link to this record



	Author	Touma, C.; Sachser, N.; Mostl, E.; Palme, R.
	Title	Effects of sex and time of day on metabolism and excretion of corticosterone in urine and feces of mice			Type	Journal Article
	Year	2003	Publication	General and Comparative Endocrinology	Abbreviated Journal	Gen Comp Endocrinol
	Volume	130	Issue	3	Pages	267-278
	Keywords	Animals; Chromatography, High Pressure Liquid; Circadian Rhythm/physiology; Corticosterone/metabolism/urine; Feces/*chemistry; Female; Immunoenzyme Techniques; Kinetics; Male; Mice; Mice, Inbred C57BL; Reference Values; Sex Factors; Stress/metabolism; Time Factors; Tritium
	Abstract	Non-invasive techniques to monitor stress hormones in small animals like mice offer several advantages and are highly demanded in laboratory as well as in field research. Since knowledge about the species-specific metabolism and excretion of glucocorticoids is essential to develop such a technique, we conducted radiometabolism studies in mice (Mus musculus f. domesticus, strain C57BL/6J). Each mouse was injected intraperitoneally with 740 kBq of 3H-labelled corticosterone and all voided urine and fecal samples were collected for five days. In a first experiment 16 animals (eight of each sex) received the injection at 9 a.m., while eight mice (four of each sex) were injected at 9 p.m. in a second experiment. In both experiments radioactive metabolites were recovered predominantly in the feces, although males excreted significantly higher proportions via the feces (about 73%) than females (about 53%). Peak radioactivity in the urine was detected within about 2h after injection, while in the feces peak concentrations were observed later (depending on the time of injection: about 10h postinjection in experiment 1 and about 4h postinjection in experiment 2, thus proving an effect of the time of day). The number and relative abundance of fecal [3H]corticosterone metabolites was determined by high performance liquid chromatography (HPLC). The HPLC separations revealed that corticosterone was extensively metabolized mainly to more polar substances. Regarding the types of metabolites formed, significant differences were found between males and females, but not between the experiments. Additionally, the immunoreactivity of these metabolites was assessed by screening the HPLC fractions with four enzyme immunoassays (EIA). However, only a newly established EIA for 5alpha-pregnane-3beta,11beta,21-triol-20-one (measuring corticosterone metabolites with a 5alpha-3beta,11beta-diol structure) detected several peaks of radioactive metabolites with high intensity in both sexes, while the other EIAs showed only minor immunoreactivity. Thus, our study for the first time provides substantial information about metabolism and excretion of corticosterone in urine and feces of mice and is the first demonstrating a significant impact of the animals' sex and the time of day. Based on these data it should be possible to monitor adrenocortical activity non-invasively in this species by measuring fecal corticosterone metabolites with the newly developed EIA. Since mice are extensively used in research world-wide, this could open new perspectives in various fields from ecology to behavioral endocrinology.
	Address	Department of Behavioral Biology, Institute of Neuro and Behavioral Biology, University of Muenster, Badestrasse 9, D-48149 Muenster, Germany. touma@uni-muenster.de
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language	English	Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0016-6480	ISBN		Medium
	Area		Expedition		Conference
	Notes	PMID:12606269			Approved	no
	Call Number	Equine Behaviour @ team @			Serial	4086
Permanent link to this record



	Author	Hoang, L.; Maity, H.; Krishna, M.M.G.; Lin, Y.; Englander, S.W.
	Title	Folding units govern the cytochrome c alkaline transition			Type	Journal Article
	Year	2003	Publication	Journal of Molecular Biology	Abbreviated Journal	J Mol Biol
	Volume	331	Issue	1	Pages	37-43
	Keywords	Animals; Cytochrome c Group/chemistry; Horses; Hydrogen/chemistry; Hydrogen-Ion Concentration; Kinetics; Models, Molecular; Protein Folding; Protein Structure, Tertiary; Spectrum Analysis; Titrimetry
	Abstract	The alkaline transition of cytochrome c is a model for protein structural switching in which the normal heme ligand is replaced by another group. Stopped flow data following a jump to high pH detect two slow kinetic phases, suggesting two rate-limiting structure changes. Results described here indicate that these events are controlled by the same structural unfolding reactions that account for the first two steps in the reversible unfolding pathway of cytochrome c. These and other results show that the cooperative folding-unfolding behavior of protein foldons can account for a variety of functional activities in addition to determining folding pathways.
	Address	Department of Biochemistry and Biophysics, University of Pennsylvania School of Medicine, Philadelphia, PA 19104-6059, USA. lhoang@mail.upenn.edu
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language	English	Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0022-2836	ISBN		Medium
	Area		Expedition		Conference
	Notes	PMID:12875834			Approved	no
	Call Number	Equine Behaviour @ team @			Serial	3781
Permanent link to this record



	Author	Hirota, S.; Suzuki, M.; Watanabe, Y.
	Title	Hydrophobic effect of trityrosine on heme ligand exchange during folding of cytochrome c			Type	Journal Article
	Year	2004	Publication	Biochemical and Biophysical Research Communications	Abbreviated Journal	Biochem Biophys Res Commun
	Volume	314	Issue	2	Pages	452-458
	Keywords	Amino Acids/chemistry; Animals; Cytochromes c/chemistry; Heme/chemistry; Histidine/chemistry; Horses; Hydrogen-Ion Concentration; Kinetics; Ligands; Myocardium/chemistry; Peptides/chemistry; Protein Folding; Spectrophotometry; Spectrum Analysis, Raman; Tyrosine/analogs & derivatives/chemistry
	Abstract	Effect of a hydrophobic peptide on folding of oxidized cytochrome c (cyt c) is studied with trityrosine. Folding of cyt c was initiated by pH jump from 2.3 (acid-unfolded) to 4.2 (folded). The Soret band of the 2-ms transient absorption spectrum during folding decreased its intensity and red-shifted from 397 to 400 nm by interaction with trityrosine, whereas tyrosinol caused no significant effect. The change in the transient absorption spectrum by interaction with trityrosine was similar to that obtained with 100 mM imidazole, which showed that the population of the intermediate His/His coordinated species increased during folding of cyt c by interaction with trityrosine. The absorption change was biphasic, the fast phase (82+/-9s(-1)) corresponding to the transition from the His/H(2)O to the His/Met coordinated species, whereas the slow phase (24+/-3s(-1)) from His/His to His/Met. By addition of trityrosine, the relative ratio of the slow phase increased, due to increase of the His/His species at the initial stage of folding. According to the resonance Raman spectra of cyt c, the high-spin 6-coordinate and low-spin 6-coordinate species were dominated at pH 2.3 and 4.2, respectively, and these species were not affected by addition of trityrosine. These results demonstrated that the His/His species increased by interaction with trityrosine at the initial stage of cyt c folding, whereas the heme coordination structure was not affected by trityrosine when the protein was completely unfolded or folded. Hydrophobic peptides thus may be useful to study the effects of hydrophobic interactions on protein folding.
	Address	Department of Physical Chemistry, Kyoto Pharmaceutical University, Yamashina-ku, 607-8414 Kyoto, Japan. hirota@mb.kyoto-phu.ac.jp
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language	English	Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0006-291X	ISBN		Medium
	Area		Expedition		Conference
	Notes	PMID:14733927			Approved	no
	Call Number	Equine Behaviour @ team @			Serial	3777
Permanent link to this record



	Author	Dirikolu, L.; Lehner, A.F.; Karpiesiuk, W.; Hughes, C.; Woods, W.E.; Boyles, J.; Harkins, J.D.; Troppmann, A.; Tobin, T.
	Title	Detection, quantification, metabolism, and behavioral effects of selegiline in horses			Type	Journal Article
	Year	2003	Publication	Veterinary Therapeutics : Research in Applied Veterinary Medicine	Abbreviated Journal	Vet Ther
	Volume	4	Issue	3	Pages	257-268
	Keywords	Administration, Oral; Animals; Behavior, Animal/drug effects; Female; Horses/metabolism; Mass Spectrometry/veterinary; Monoamine Oxidase Inhibitors/administration & dosage/blood/pharmacokinetics/pharmacology/urine; Selegiline/administration & dosage/blood/*pharmacokinetics/pharmacology/urine; Substance Abuse Detection/veterinary
	Abstract	Selegiline ([R]-[-]N,alpha-dimethyl-N-2- propynylphenethylamine or l-deprenyl), an irreversible inhibitor of monoamine oxidase, is a classic antidyskinetic and antiparkinsonian agent widely used in human medicine both as monotherapy and as an adjunct to levodopa therapy. Selegiline is classified by the Association of Racing Commissioners International (ARCI) as a class 2 agent, and is considered to have high abuse potential in racing horses. A highly sensitive LC/MS/MS quantitative analytical method has been developed for selegiline and its potential metabolites amphetamine and methamphetamine using commercially available deuterated analogs of these compounds as internal standards. After administering 40 mg of selegiline orally to two horses, relatively low (<60 ng/ml) concentrations of parent selegiline, amphetamine, and methamphetamine were recovered in urine samples. However, relatively high urinary concentrations of another selegiline metabolite were found, tentatively identified as N- desmethylselegiline. This metabolite was synthesized and found to be indistinguishable from the new metabolite recovered from horse urine, thereby confirming the chemical identity of the equine metabolite. Additionally, analysis of urine samples from four horses dosed with 50 mg of selegiline confirmed that N-desmethylselegiline is the major urinary metabolite of selegiline in horses. In related behavior studies, p.o. and i.v. administration of 30 mg of selegiline produced no significant changes in either locomotor activities or heart rates.
	Address	Department of Biomedical Sciences, College of Veterinary Medicine, Nursing and Allied Health, Tuskegee University, Tuskegee, AL 36088, USA
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language	English	Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	1528-3593	ISBN		Medium
	Area		Expedition		Conference
	Notes	PMID:15136987			Approved	no
	Call Number				Serial	1901
Permanent link to this record



	Author	Guo, G.L.; Moffit, J.S.; Nicol, C.J.; Ward, J.M.; Aleksunes, L.A.; Slitt, A.L.; Kliewer, S.A.; Manautou, J.E.; Gonzalez, F.J.
	Title	Enhanced acetaminophen toxicity by activation of the pregnane X receptor			Type	Journal Article
	Year	2004	Publication	Toxicological sciences : an official journal of the Society of Toxicology	Abbreviated Journal	Toxicol Sci
	Volume	82	Issue	2	Pages	374-380
	Keywords	Acetaminophen/pharmacokinetics/toxicity; Analgesics, Non-Narcotic/pharmacokinetics/toxicity; Animals; Aryl Hydrocarbon Hydroxylases/biosynthesis; Biotransformation; Blotting, Northern; Chromatography, High Pressure Liquid; Cytochrome P-450 CYP3A; Membrane Proteins; Mice; Mice, Knockout; Oxidoreductases, N-Demethylating/biosynthesis; Pregnenolone Carbonitrile/pharmacology; Receptors, Cytoplasmic and Nuclear/drug effects; Receptors, Steroid/drug effects; Sulfhydryl Compounds/metabolism
	Abstract	The pregnane X receptor (PXR) is a ligand-activated transcription factor and member of the nuclear receptor superfamily. Activation of PXR represents an important mechanism for the induction of cytochrome P450 3A (CYP3A) enzymes that can convert acetaminophen (APAP) to its toxic intermediate metabolite, N-acetyl-p-benzoquinone imine (NAPQI). Therefore, it was hypothesized that activation of PXR plays a major role in APAP-induced hepatotoxicity. Pretreatment with the PXR activator, pregnenolone 16alpha-carbonitrile (PCN), markedly enhanced APAP-induced hepatic injury, as revealed by increased serum ALT levels and hepatic centrilobular necrosis, in wild-type but not in PXR-null mice. Further analysis showed that following PCN treatment, PXR-null mice had lower CYP3A11 expression, decreased NAPQI formation, and increased maintenance of hepatic glutathione content compared to wild-type mice. Thus, these results suggest that PXR plays a critical role in APAP-induced hepatic toxicity, probably by inducing CYP3A11 expression and hence increasing bioactivation.
	Address	Laboratory of Metabolism, CCR, NCI, NIH, Bethesda, Maryland 20892, USA
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language	English	Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	1096-6080	ISBN		Medium
	Area		Expedition		Conference
	Notes	PMID:15456926			Approved	no
	Call Number	refbase @ user @			Serial	71
Permanent link to this record



	Author	Abbruzzetti, S.; Viappiani, C.; Sinibaldi, F.; Santucci, R.
	Title	Kinetics of histidine dissociation from the heme Fe(III) in N-fragment (residues 1-56) of cytochrome c			Type	Journal Article
	Year	2004	Publication	The Protein Journal	Abbreviated Journal	Protein J
	Volume	23	Issue	8	Pages	519-527
	Keywords	Animals; Cytochromes c/chemistry; Enzyme Activation; Histidine/chemistry; Horses; Hydrogen-Ion Concentration; Kinetics; Lasers; Ligands; Peptide Mapping; Photolysis; Spectrophotometry
	Abstract	We have here investigated the dissociation kinetics of the His side chains axially ligated to the heme-iron in the ferric (1-56 residues) N-fragment of horse cyt c. The ligand deligation induced by acidic pH-jump occurs as a biexponential process with different pre-exponential factors, consistent with a structural heterogeneity in solution and the presence of two differently coordinated species. In analogy with GuHCl-denatured cyt c, our data indicate the presence in solution of two ferric forms of the N-fragment characterized by bis-His coordination, as summarized in the following scheme: His18-Fe(III)-His26 <==> His18-Fe(III)-His33. We have found that the pre-exponential factors depend on the extent of the pH-jump. This may be correlated with the different pKa values shown by His26 and His33; due to steric factors, His26 binds to the heme-Fe(III) less strongly than His33, as recently shown by studies on denatured cyt c. Interestingly, the two lifetimes are affected by temperature but not by the extent of the pH-jump. The lower pKa for the deligation reaction required the use of an improved laser pH-jump setup, capable of inducing changes in H+ concentration as large as 1 mM after the end of the laser pulse. For the ferric N-fragment, close activation entropy values have been determined for the two histidines coordinated to the iron; this result significantly differs from that for GuHCl-denatured cyt c, where largely different values of activation entropy were calculated. This underlines the role played by the missing segment (residues 57-104) peptide chain in discriminating deligation of the “nonnative” His from the sixth coordination position of the metal.
	Address	Dipartimento di Fisica, Universita degli Studi di Parma, Parco Area delle Scienze 7/A 43100 Parma, Italy
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language	English	Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	1572-3887	ISBN		Medium
	Area		Expedition		Conference
	Notes	PMID:15648974			Approved	no
	Call Number	Equine Behaviour @ team @			Serial	3770
Permanent link to this record



	Author	Steinhoff, H.J.; Schrader, J.; Schlitter, J.
	Title	Temperature-jump studies and polarized absorption spectroscopy of methemoglobin-thiocyanate single crystals			Type	Journal Article
	Year	1992	Publication	Biochimica et Biophysica Acta	Abbreviated Journal	Biochim Biophys Acta
	Volume	1121	Issue	3	Pages	269-278
	Keywords	Animals; Crystallization; Horses; Kinetics; Methemoglobin/chemistry; Solutions; Spectrum Analysis; Temperature; Thiocyanates/chemistry
	Abstract	Association equilibria and association kinetics of the thiocyanate binding reaction to methemoglobin in single crystals and solution are studied using temperature-jump technique and polarized absorption spectroscopy. Different kinetic constants are found for the reaction in solution and crystal phase for the alpha- and beta-subunits of the methemoglobin tetramer. The reduction of the reactivity of the alpha- and beta-subunits in crystalline phase is 6-fold and 2.4-fold, respectively, compared to the values found in solution. The intramolecular binding reaction of the N epsilon of the distal histidine E7 which is observed in methemoglobin in solution cannot be detected in single crystals. Our results suggest that crystallization of hemoglobin has little influence on small-scale structural fluctuations which are necessary for ligands to get to the binding sites and large-scale structural motions are suppressed.
	Address	Institut fur Biophysik, Ruhr-Universitat Bochum, Germany
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language	English	Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0006-3002	ISBN		Medium
	Area		Expedition		Conference
	Notes	PMID:1627604			Approved	no
	Call Number	Equine Behaviour @ team @			Serial	3800
Permanent link to this record



	Author	Bykov, S.; Lednev, I.; Ianoul, A.; Mikhonin, A.; Munro, C.; Asher, S.A.
	Title	Steady-state and transient ultraviolet resonance Raman spectrometer for the 193-270 nm spectral region			Type	Journal Article
	Year	2005	Publication	Applied Spectroscopy	Abbreviated Journal	Appl Spectrosc
	Volume	59	Issue	12	Pages	1541-1552
	Keywords	Animals; Equipment Design; Equipment Failure Analysis; Horses; Kinetics; Metmyoglobin/analysis; Myocardium/metabolism; Reproducibility of Results; Sensitivity and Specificity; Spectrophotometry, Ultraviolet/instrumentation/methods; Spectrum Analysis, Raman/instrumentation/methods
	Abstract	We describe a state-of-the-art tunable ultraviolet (UV) Raman spectrometer for the 193-270 nm spectral region. This instrument allows for steady-state and transient UV Raman measurements. We utilize a 5 kHz Ti-sapphire continuously tunable laser (approximately 20 ns pulse width) between 193 nm and 240 nm for steady-state measurements. For transient Raman measurements we utilize one Coherent Infinity YAG laser to generate nanosecond infrared (IR) pump laser pulses to generate a temperature jump (T-jump) and a second Coherent Infinity YAG laser that is frequency tripled and Raman shifted into the deep UV (204 nm) for transient UV Raman excitation. Numerous other UV excitation frequencies can be utilized for selective excitation of chromophoric groups for transient Raman measurements. We constructed a subtractive dispersion double monochromator to minimize stray light. We utilize a new charge-coupled device (CCD) camera that responds efficiently to UV light, as opposed to the previous CCD and photodiode detectors, which required intensifiers for detecting UV light. For the T-jump measurements we use a second camera to simultaneously acquire the Raman spectra of the water stretching bands (2500-4000 cm(-1)) whose band-shape and frequency report the sample temperature.
	Address	Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, USA
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language	English	Summary Language		Original Title
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0003-7028	ISBN		Medium
	Area		Expedition		Conference
	Notes	PMID:16390595			Approved	no
	Call Number	Equine Behaviour @ team @			Serial	3767
Permanent link to this record

Select All Deselect All

<< 1 2 3 4 >>

Details

CQL Search | Library Search | Show Record | Extract Citations

Help