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Articles 511 - 540 of 592
Full-Text Articles in Chemistry
Sodium Nitrite Alone Protects The Brain O _I_ Microsomal Ca -Atpase Against Potassium Cyanide-Induced Neurotoxicity In Rats, Odutayo O. Odunuge, G.. A. Adenuga
Sodium Nitrite Alone Protects The Brain O _I_ Microsomal Ca -Atpase Against Potassium Cyanide-Induced Neurotoxicity In Rats, Odutayo O. Odunuge, G.. A. Adenuga
Faculty Publications
The effect of a short-term oral administration of potassium cyanide (KCN) (200 ppm in diet) with or without sodium nitrite (NaNO2) pretreatment on rat brain microsomal Ca2* ATPase was investigated. The specific activity value of the enzyme significantly decreased (p<0.05) by 50% compared with control and by 63% for KCN-treated rats compared with KCN-treated rats pretreated with NaNO;,. There was no significant difference at the h = 0.05 level between the values obtained for the control and KCN-treated rats pretreated with NaNO,. These results show both that feeding lowers brain microsomal Ca2f-ATPase activity and that NaNO, has a protective role (antidote function) in that respect.
Semiclassical Approach To The Hydrogen-Exchange Reaction- Reactive And Transition-State Dynamics, Sophya V. Garashchuk, Grossmann Frank, David Tannor
Semiclassical Approach To The Hydrogen-Exchange Reaction- Reactive And Transition-State Dynamics, Sophya V. Garashchuk, Grossmann Frank, David Tannor
Faculty Publications
Scattering matrix elements and symmetric transition-state resonances for the collinear H 2 + H → H + H 2 reaction are obtained using a time-dependent approach. The correlation function between reactant channel wavepackets and product channel wavepackets is used to determine the S-matrix elements. In a similar fashion, autocorrelation functions are used to extract the positions and widths of transition-state resonances. The time propagation of the wavepackets is performed by the improved semiclassical frozen Gaussian method of Herman and Kluk, which is an initial value, uniformly converged method. The agreement between the quantum and semiclassical results is far better …
Inhomogeneity In Gelation And Nonuniversality Of Sol-To-Gel Transitions Studied By A Computer Simulation Model, Yi-Min Liu, R.B. Pandey
Inhomogeneity In Gelation And Nonuniversality Of Sol-To-Gel Transitions Studied By A Computer Simulation Model, Yi-Min Liu, R.B. Pandey
Faculty Publications
No abstract provided.
Kinetics And Jamming Coverage In A Random Sequential Adsorption Of Polymer Chains, Jian-Sheng Wang, Ras B. Pandey
Kinetics And Jamming Coverage In A Random Sequential Adsorption Of Polymer Chains, Jian-Sheng Wang, Ras B. Pandey
Faculty Publications
No abstract provided.
The Advanced Glycation End Product, NE-(Carboxymethyl)Lysine, Is A Product Of Both Lipid Peroxidation And Glycoxidation Reactions, Min-Xin Fu, Jesus R. Requena, Alicia J. Jenkins, Timothy J. Lyons, John W. Baynes, Suzanne R. Thorpe
The Advanced Glycation End Product, NE-(Carboxymethyl)Lysine, Is A Product Of Both Lipid Peroxidation And Glycoxidation Reactions, Min-Xin Fu, Jesus R. Requena, Alicia J. Jenkins, Timothy J. Lyons, John W. Baynes, Suzanne R. Thorpe
Faculty Publications
Nepsilon-(Carboxymethyl)lysine (CML) is an advanced glycation end product formed on protein by combined nonenzymatic glycation and oxidation (glycoxidation) reactions. We now report that CML is also formed during metal-catalyzed oxidation of polyunsaturated fatty acids in the presence of protein. During copper-catalyzed oxidation in vitro, the CML content of low density lipoprotein increased in concert with conjugated dienes but was independent of the presence of the Amadori compound, fructoselysine, on the protein. CML was also formed in a time-dependent manner in RNase incubated under aerobic conditions in phosphate buffer containing arachidonate or linoleate; only trace amounts of CML were formed from …
Dynamics And Conformation Of Polymer Chains In A Porous Medium, Grace M. Foo, R.B. Pandey, D. Stauffer
Dynamics And Conformation Of Polymer Chains In A Porous Medium, Grace M. Foo, R.B. Pandey, D. Stauffer
Faculty Publications
No abstract provided.
A New High Pressure Sapphire Nuclear Magnetic Resonance Cell, Shi Bai, Craig M. Taylor, Charles L. Mayne, Ronald J. Pugmire, David M. Grant
A New High Pressure Sapphire Nuclear Magnetic Resonance Cell, Shi Bai, Craig M. Taylor, Charles L. Mayne, Ronald J. Pugmire, David M. Grant
Faculty Publications
A new version of a single-crystal sapphire high pressure nuclear magnetic resonance (NMR) cell is described that is capable of controlling the sample pressure independent of the temperature. A movable piston inside the cell adjusts and controls the sample pressure from ambient conditions to 200 atm within plus or minus 0.3 atm. The linewidth at half-height for a 13C spectrum of carbon dioxide at 15degrees C and 57.8 atm is found to be 0.5 Hz. The carbon dioxide gas/liquid phase transition is clearly observed by measuring 13C chemical shifts as the sample pressure approaches equilibrium. The time required for this …
Galvanostatic Pulse And Pulse Reverse Plating Of Zinc-Nickel Alloys From Sulfate Electrolytes On A Rotating Disc Electrode, Branko N Popov, M. Ramasubramanian, S. N. Popova, Ralph E. White, K-M. Yin
Galvanostatic Pulse And Pulse Reverse Plating Of Zinc-Nickel Alloys From Sulfate Electrolytes On A Rotating Disc Electrode, Branko N Popov, M. Ramasubramanian, S. N. Popova, Ralph E. White, K-M. Yin
Faculty Publications
Galvanostatic pulse and pulse reverse techniques have been used to study the plating of zinc–nickel alloys in the presence of nonyl phenyl polyethylene oxide. The effects of average current density, rotation speed of disc electrode and the presence of nonyl phenyl polyethylene oxide in the electrolyte on deposition of zinc–nickel alloys were evaluated. Zinc–nickel plating bath solution chemistry was studied by determining the equilibrium concentrations at various pH levels. It was found that the alloy composition was determined by solution equilibria, mass transfer of the electroactive species within the diffusion layer and by the surface coverage of nonyl phenyl polyethylene …
Structure Factors Of Binary Fluids In A Dilute Gel, J.C. Lee
Structure Factors Of Binary Fluids In A Dilute Gel, J.C. Lee
Faculty Publications
The statio and dynamic structure factors of binary fluids in a dilute gel are computed using a two-dimensional kinetic Ising model. The wetting effect of the gel strands is modeled with ''gel atoms'' which are distributed randomly among the spins and impose a field on their neighboring spins, all in the same direction. The result for the static structure factor shows the presence of adsorption clusters which mask the gel atoms. The result for the dynamic Structure factor shows an extremely slow relaxation-at late times which cannot be fitted in the form of the activated dynamic scaling known for random-field …
Ultrastructural Immunolocalization Of Histones (H2b, H3, H4), Transition Protein (Tp1) And Protamine In Rabbit Spermatids And Spermatozoa Nuclei. Relation To Condensation Of The Chromatin, J L. Courtens, Wilson Stephen Kistler, L Plöen
Ultrastructural Immunolocalization Of Histones (H2b, H3, H4), Transition Protein (Tp1) And Protamine In Rabbit Spermatids And Spermatozoa Nuclei. Relation To Condensation Of The Chromatin, J L. Courtens, Wilson Stephen Kistler, L Plöen
Faculty Publications
The histones H2B, H3 and H4, the transition protein TP1 and protamine were localised using ultrastructural immunocytochemistry in nuclei of rabbit spermatids and spermatozoa. Histones are present in round spermatid nuclei and are lost during the elongation of nuclei. TP1 and protamine appear simultaneously in all nuclei during this period. TP1 is located at the periphery of chromatin cords, while protamine seems to be located at random in the same cords. TP1 is lost in most elongated sprematids during step 13 of spermiogenesis, and the protamine stays in all sperm nuclei. TP1 remains persent in some old spermatids and ejaculated …
Accuracy Of Deoxynucleotide Incorporation By Soybean Chloroplast Dna-Polymerases Is Independent Of The Presence Of A 3' To 5' Exonuclease, J. Clinton Bailey Ii, Sabine Heinhorst, Gordon C. Cannon
Accuracy Of Deoxynucleotide Incorporation By Soybean Chloroplast Dna-Polymerases Is Independent Of The Presence Of A 3' To 5' Exonuclease, J. Clinton Bailey Ii, Sabine Heinhorst, Gordon C. Cannon
Faculty Publications
DNA polymerase was purified from soybean (Glycine max) chloroplasts that were actively replicating DNA. The main form (form I) of the enzyme was associated with a low level of 3' to 5' exonuclease activity throughout purification, although the ratio of exonuclease to polymerase activity decreased with each successive purification step. A second form (form II) of DNA polymerase, which elutes from DEAE-cellulose at a higher salt concentration than form I, was devoid of any exonuclease activity. To assess the potential function of the 3' to 5' exonuclease in proofreading, the fidelity of deoxynucleotide incorporation was measured for form I DNA …
New Optical Cell Design For Laser Flash Photolysis Studies In Supercritical Fluids, Steven R. Goates, Milton L. Lee, Qin Ji, Edward M. Eyring, Rudi Van Eldik, Kedika Bal Reddy
New Optical Cell Design For Laser Flash Photolysis Studies In Supercritical Fluids, Steven R. Goates, Milton L. Lee, Qin Ji, Edward M. Eyring, Rudi Van Eldik, Kedika Bal Reddy
Faculty Publications
A high-pressure optical cell has been designed that achieves an effective separation between the chemical sample and the pressurizing medium and system. This design limits possible sample contamination and catalytic effects under supercritical fluid sample conditions. Laser flash photolysis experiments were carried out on molybdenum hexacarbonyl dissolved in supercritical CO2. The thermal ring closure reaction of the species Mo(CO)5L, where L is 2,2- bipyridine was found to proceed at rates comparable to those measured previously in liquid benzene or toluene. Much larger activation volumes were found for the reaction in supercritical CO2 than in liquid toluene.
Semiclassical Quantization Of A Nonintegrable System: Pushing The Fourier Method Into The Chaotic Regime, Karl Sohlberg, Randall B. Shirts
Semiclassical Quantization Of A Nonintegrable System: Pushing The Fourier Method Into The Chaotic Regime, Karl Sohlberg, Randall B. Shirts
Faculty Publications
Semiclassical Einstein–Brillouin–Keller (EBK) quantization of the nonintegrable Hénon–Heiles Hamiltonian succeeds using the Fourier transform method of Martens and Ezra. Two innovations are required for this success: (1) the use of tunneling corrected quantizing actions obtained from an approximate, one-dimensional Hamiltonian and (2) exploitation of intermediate-time approximate quasiperiodicity or "vague tori'' wherein the Fourier transform of chaotic motion over 10–100 vibrational periods allows the determination of frequencies and amplitudes which approximate motion during the time interval. Approximate tori, actions, and EBK energy levels are then straightforward. We use an interpolation method to smooth over small resonance zones that are not expected …
The Structure And Dynamics Of The Cs2 Molecular Ion, Karl Sohlberg, Chan Yibai
The Structure And Dynamics Of The Cs2 Molecular Ion, Karl Sohlberg, Chan Yibai
Faculty Publications
Several common elementary methods of computing molecular properties, prerequisite to molecular dynamics studies, are tested for their validity for CS+2. Judged sufficiently accurate, these methods are then used to aid in investigating the collisionally activated dissociation of CS+2 upon impact with xenon. Rice–Ramsperger–Kassel–Marcus (RRKM) unimolecular decay rate calculations are presented and compared to experimental studies employing collisional activation. RRKM theory is shown to reproduce the experimental results for collision energies near threshold. When corrected for vibrational anharmonicity, the RRKM calculation shows agreement with the experimental results over a slightly wider range of energies. A discussion is given on the applicability …
Purification And Characterization Of A Gamma-Like Dna-Polymerase From Chenopodium Album L., K. Meißner, Sabine Heinhorst, Gordon C. Cannon, T. Börner
Purification And Characterization Of A Gamma-Like Dna-Polymerase From Chenopodium Album L., K. Meißner, Sabine Heinhorst, Gordon C. Cannon, T. Börner
Faculty Publications
A DNA polymerase activity from mitochondria of the dicotyledonous angiosperm Chenopodium album L. was purified almost 9000 fold by successive column chromatography steps on DEAE cellulose, heparin agarose and ssDNA cellulose. The enzyme was characterized as a gamma-class polymerase, based on its resistance to inhibitors of the nuclear DNA polymerase alpha and its preference for poly(rA).(dT)12-18 over activated DNA in vitro. The molecular weight was estimated to be 80,000 - 90,000. A 3' to 5' exonuclease activity was found to be tightly associated with the DNA polymerase activity through all purification steps. This is the first report of an association …
Radially Symmetrical Flow Of Reacting Liquid With Changing Viscosity, S.E. Solovyov, V.A. Volpert, S.P. Davytan
Radially Symmetrical Flow Of Reacting Liquid With Changing Viscosity, S.E. Solovyov, V.A. Volpert, S.P. Davytan
Faculty Publications
Frontal regimens for one-dimensional flow of reacting liquid with changing viscosity are studied. Stationary solutions are investigated for the case of narrow reaction zones that shrink to a front. The results of numerical solution of the nonstationary problem are presented. Complex oscillations resulting from period-doubling bifurcations are found.
Formation Of O-Tyrosine And Dityrosine In Proteins During Radiolytic And Metal-Catalyzed Oxidation, Thomas G. Huggins, Mary C. Wells-Knecht, Nicholas A. Detorie, John W. Baynes, Suzanna R. Thorpe
Formation Of O-Tyrosine And Dityrosine In Proteins During Radiolytic And Metal-Catalyzed Oxidation, Thomas G. Huggins, Mary C. Wells-Knecht, Nicholas A. Detorie, John W. Baynes, Suzanna R. Thorpe
Faculty Publications
To evaluate their usefulness as chemical indicators of cumulative oxidative damage to proteins, we studied the kinetics and extent of formation of ortho-tyrosine (0-Tyr), dityrosine (DT), and dityrosine-like fluorescence (Ex = 3 17 nm, E,,, = 407 nm) in the model proteins RNase and lysozyme exposed to radiolytic and metalcatalyzed (H20z/Cu2+) oxidation (MCO). Although there were protein-dependent differences, o-Tyr, DT, and fluorescence increased coordinately during oxidation of the proteins in both oxidation systems. The contribution of DT to total dityrosine-like fluorescence in oxidized proteins varied from 2-10070, depending on the protein, type of oxidation, and extent of oxidative damage. In …
Oxidized Amino Acids In Lens Protein With Age: Measurement Of O-Tyrosine And Dityrosine In The Aging Human Lens, Mary C. Wells-Knect, Thomas G. Huggins, Daniel G. Dyer, Suzanne R. Thorpe, John W. Baynes
Oxidized Amino Acids In Lens Protein With Age: Measurement Of O-Tyrosine And Dityrosine In The Aging Human Lens, Mary C. Wells-Knect, Thomas G. Huggins, Daniel G. Dyer, Suzanne R. Thorpe, John W. Baynes
Faculty Publications
The concentrations of ortho-tyrosine (o-Tyr) and dityrosine (DT) were measured in noncataractous human lenses in order to assess the role of proteinoxidation reactions in the aging of lens proteins. The measurements were conducted by selected ion monitoring-gas chromatography/mass spectrometry using deuterium-labeled internal standards, which provided both high sensitivity and specificity for the quantitation of o-Tyr and DT. Between ages 1 and 78 years, the o-Tyr concentration in lens proteins varied from 0.3 to 0.9 mmol of o-Tyr/mol of Phe (n = 19), while DT ranged from 1 to 3 mumol of DT/mol of Tyr (n = 30). There were no …
Accumulation Of Maillard Reaction Products In Skin Collagen In Diabetes And Aging, Daniel G. Dyer, John A. Dunn, Suzanne R. Thorpe, Karen E. Bailie, Timothy L. Lyons, David R. Mccance, John W. Baynes
Accumulation Of Maillard Reaction Products In Skin Collagen In Diabetes And Aging, Daniel G. Dyer, John A. Dunn, Suzanne R. Thorpe, Karen E. Bailie, Timothy L. Lyons, David R. Mccance, John W. Baynes
Faculty Publications
To investigate the contribution of glycation and oxidation reactions to the modification of insoluble collagen in aging and diabetes, Maillard reaction products were measured in skin collagen from 39 type 1 diabetic patients and 52 nondiabetic control subjects. Compounds studied included fructoselysine (FL), the initial glycation product, and the glycoxidation products, N epsilon-(carboxymethyl) lysine (CML) and pentosidine, formed during later Maillard reactions. Collagen-linked fluorescence was also studied. In nondiabetic subjects, glycation of collagen (FL content) increased only 33% between 20 and 85 yr of age. In contrast, CML, pentosidine and fluorescence increased five-fold, correlating strongly with age. In diabetic patients, …
Maillard Reaction Products And Their Relation To Complications In Insulin-Dependent Diabetes Mellitus, David R. Mccance, Daniel G. Dryer, John A. Dunn, Karen E. Bailie, Suzanne R. Thorpe, John W. Baynes, Timothy J. Lyons
Maillard Reaction Products And Their Relation To Complications In Insulin-Dependent Diabetes Mellitus, David R. Mccance, Daniel G. Dryer, John A. Dunn, Karen E. Bailie, Suzanne R. Thorpe, John W. Baynes, Timothy J. Lyons
Faculty Publications
Glycation, oxidation, and browning of proteins have all been implicated in the development of diabetic complications. We measured the initial Amadori adduct, fructoselysine (FL); two Maillard products, N epsilon-(carboxymethyl) lysine (CML) and pentosidine; and fluorescence (excitation = 328 nm, emission = 378 nm) in skin collagen from 39 type 1 diabetic patients (aged 41.5 +/- 15.3 [17-73] yr; duration of diabetes 17.9 +/- 11.5 [0-46] yr, [mean +/- SD, range]). The measurements were related to the presence of background (n = 9) or proliferative (n = 16) retinopathy; early nephropathy (24-h albumin excretion rate [AER24] > or = 20 micrograms/min; n …
Development Of New Methods For Assessing Solidification/Stabilization Of Hazardous Waste Using Solid-State Nuclear Magnetic Resonance Techniques (Ph.D Dissertation, Lsu), Michael A. Janusa
Development Of New Methods For Assessing Solidification/Stabilization Of Hazardous Waste Using Solid-State Nuclear Magnetic Resonance Techniques (Ph.D Dissertation, Lsu), Michael A. Janusa
Faculty Publications
New methods for assessing solidification/stabilization (S/S) of hazardous waste using solid-state nuclear magnetic resonance are developed for the purpose of diagnosing on a microscopic level the performance of S/S as a hazardous waste disposal technique. There are four techniques developed and described in this dissertation: (1) Solid-state deuterium NMR spectroscopy is used to determine if a particular deuterated organic waste is effectively solidified/stabilized and to determine the lower limit of the bond strength between the waste and the cement matrix; (2) Constant time pulsed field gradient ^ NMR spectroscopy is tested on a liquid waste encapsulated within a solidified matrix …
Solid-State Deuterium Nmr Spectroscopy Of D5-Phenol In White Portland Cement: A New Method For Assessing Solidification/Stabilization, Michael A. Janusa
Solid-State Deuterium Nmr Spectroscopy Of D5-Phenol In White Portland Cement: A New Method For Assessing Solidification/Stabilization, Michael A. Janusa
Faculty Publications
We have developed a new NMR-based procedure for studying waste/cement interactions. This is the first use of deuterium NMR spectroscopy to study waste solidification/ stabilization (S/S). The main feature of deuterium NMR spectroscopy is the ability to monitor molecular reorientations over a wide range of reorientation rates. This technique allows one to determine if a particular deuterated organic waste is effectively solidified/ stabilized and to determine the lower limit of the bond strength between the waste and the cement matrix. Comparison of the predicted and experimental deuterium NMR spectra show that phenol is mainly dissolved in pore waters and, thus, …
Dna Replication In Chloroplasts, Sabine Heinhorst, Gordon C. Cannon
Dna Replication In Chloroplasts, Sabine Heinhorst, Gordon C. Cannon
Faculty Publications
Chloroplasts contain multiple copies of a DNA molecule (the plastome) that encodes many of the gene products required to perform photosynthesis. The plastome is replicated by nuclear-encoded proteins and its copy number seems to be highly regulated by the cell in a tissue-specific and developmental manner. Our understanding of the biochemical mechanism by which the plastome is replicated and the molecular basis for its regulation is limited. In this commentary we review our present understanding of chloroplast DNA replication and examine current efforts to elucidate its mechanism at a molecular level.
Drying Of Beulah-Zap Lignite, Karl S. Vorres, David L. Wertz, Vivak Malhotra, Yuhong Dang, J.T. Joseph, Ronald Fisher
Drying Of Beulah-Zap Lignite, Karl S. Vorres, David L. Wertz, Vivak Malhotra, Yuhong Dang, J.T. Joseph, Ronald Fisher
Faculty Publications
Lignite dried in a stream of dry nitrogen at moderate temperatures (20-80-degrees-C) loses water in two distinguishable modes. The first mode represents about 80-85% of the loss of moisture. The second represents the other 15-20% lost under these conditions. The rate follows a unimolecular mechanism (like radioactive decay) for each mode. The activation energy for the first mode is close to the heat of vaporization of water. The rate is dependent upon the gas flow around the sample and the weight (or thickness) of the sample. Work at Amoco Oil Company indicated that the oil yield was higher for the …
Viscoelastic Properties Of A Liquid-Crystalline Monomer And Its Dimer, Gregory A. Dilisi, Charles Rosenblatt, Anselm C. Griffin, Uma Hari
Viscoelastic Properties Of A Liquid-Crystalline Monomer And Its Dimer, Gregory A. Dilisi, Charles Rosenblatt, Anselm C. Griffin, Uma Hari
Faculty Publications
Quasielastic-light-scattering measurements are reported for a dialkoxyphenylbenzoate monomer and its dimer in their respective nematic phases. The splay and twist elastic moduli of the dimer are found to be nearly independent of molecular length. The dimer's bend modulus, however, shows an anomalous increase with decreasing temperature well below the nematic-isotropic phase transition. Monomer viscosities are consistent with typical literature values, although γ1/ηsplay and ηbend seem to be larger than expected for the dimer, where γ1 is the twist viscosity. The results are discussed in terms of viscoelastic properties of semiflexible rods. The elastic properties in …
Solid-State Nmr Characterization Of Organics In Cement, Michael A. Janusa
Solid-State Nmr Characterization Of Organics In Cement, Michael A. Janusa
Faculty Publications
Solid-state magic angle spinning nuclear magnetic resonance (MAS NMR) has been applied to cement samples containing water-soluble organics, ethylene glycol, phenol, pbromophenol and p-chlorophenol. Cement matrix development has been followed by 29Si and27Al NMR, which shows the organics, particularly ethylene glycol, to be promoters of silicate polymerization despite the fact that they reduce the compressive strength of the pastes. 13C NMR shows that phenol is completely ionized in cement pastes, but with substituted phenols in the presence of extra added metal salts, ionization is not always complete. 2H NMR on d5 …
Characterizations Of Antimony Tri‐Sulfide Chemically Deposited With Silicotungstic Acid, O. Savadogo, K. C. Mandal
Characterizations Of Antimony Tri‐Sulfide Chemically Deposited With Silicotungstic Acid, O. Savadogo, K. C. Mandal
Faculty Publications
No abstract provided.
Formation Of Pentosidine During Nonenzymatic Browning Of Proteins By Glucose, Daniel G. Dyer, James A. Blackledge, Suzanne R. Thorpe, John W. Baynes
Formation Of Pentosidine During Nonenzymatic Browning Of Proteins By Glucose, Daniel G. Dyer, James A. Blackledge, Suzanne R. Thorpe, John W. Baynes
Faculty Publications
A fluorescent compound has been detected in proteins browned during Maillard reactions with glucose in vitro and shown to be identical to pentosidine, a pentose- derived fluorescent cross-link formed between arginine and lysine residues in collagen (Sell, D. R., and Monnier, V. M. (1989) J. Biol. Chem. 264, 21597- 2 1602). Pentosidine was the major fluorophore formed during nonenzymatic browning of ribonuclease and lysozyme by glucose, but accounted for <1% of nondisulfide cross-links in protein dimers formed during the reaction. Pentosidine was formed in greatest yields in reactions of pentoses with lysine and arginine in model systems but was also formed from glucose, fructose, ascorbate, Amadori compounds, 3-deoxyglucosone, and other sugars. Pentosidine was not formed from peroxidized polyunsaturated fatty acids or malondialdehyde. Its formation from carbohydrates was inhibited under nitrogen or anaerobic conditions and by aminoguanidine, an inhibitor of advanced glycation and browning reactions. Pentosidine was detected in human lens proteins, where its concentration increased gradually with age, but it did not exceed trace concentrations (55 Fmol/mol lysine), even in the 80-year-old lens. Although its precise carbohydrate source in vivo is uncertain and it is present in only trace concentrations in tissue proteins, pentosidine appears to be a useful biomarker for assessing cumulative damage to proteins by nonenzymatic browning reactions with carbohydrates.
Decrease In Skin Collagen Glycation With Improved Glycemic Control In Patients With Insulin-Dependent Diabetes Mellitus, Timothy J. Lyons, Karen E. Bailie, Daniel G. Dyer, John A. Dunn, John W. Baynes
Decrease In Skin Collagen Glycation With Improved Glycemic Control In Patients With Insulin-Dependent Diabetes Mellitus, Timothy J. Lyons, Karen E. Bailie, Daniel G. Dyer, John A. Dunn, John W. Baynes
Faculty Publications
Glycation, oxidation, and nonenzymatic browning of protein have all been implicated in the development of diabetic complications. The initial product of glycation of protein, fructoselysine (FL), undergoes further reactions, yielding a complex mixture of browning products, including the fluorescent lysine-arginine cross-link, pentosidine. Alternatively, FL may be cleaved oxidatively to form N(epsilon)-(carboxymethyl)lysine (CML), while glycated hydroxylysine, an amino-acid unique to collagen, may yield N(epsilon)-(carboxymethyl)hydroxylysine (CMhL). We have measured FL, pentosidine, fluorescence (excitation = 328 nm, emission = 378 nm), CML, and CMhL in insoluble skin collagen from 14 insulin-dependent diabetic patients before and after a 4-mo period of intensive therapy to …
X-Ray Study Of The Crystallization Processes In Amorphous (Zro. 64ni0. 36) 1-Xalx Alloys. [Abstract], W. D. Bruton, T. O. Callaway, Richard H. Langley, B. H. Zhang, D. G. Naugle
X-Ray Study Of The Crystallization Processes In Amorphous (Zro. 64ni0. 36) 1-Xalx Alloys. [Abstract], W. D. Bruton, T. O. Callaway, Richard H. Langley, B. H. Zhang, D. G. Naugle
Faculty Publications
The short range order in (Zr0.64Ni0.36)1−xAlx metallic glasses for values of x between 0 and 0.25 was investigated using X-ray diffraction. X-ray intensity patterns and the derived structural functions for the as-quenched samples differed only slightly with the change in aluminum concentration, suggesting that the addition of aluminum does not significantly alter the relative coordination of the zirconium and nickel atoms. Only the first two alloys in the series (x = 0, 0.05) exhibited multiple transitions in the DSC thermograms. The intermediate phase for the x = 0.05 alloy has an …