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Biomedical subjects

W J Moore

Publications and source records attributed to W J Moore.

At least 19 recordsLinked to original sources

A study of facial growth in the sooty mangabey Cercocebus atys.

This study examines the pattern of facial bone growth remodelling in the sooty mangabey (Cercocebus atys) by scanning electron microscopy (SEM) of high-accuracy replicas. The efficacy of the technique is appraised by SEM interpretations of facial remodelling in the crab-eating macaque (Macaca fascicularis) and correlative histological examination. The results indicate that the distribution of depository and resorptive areas in Cercocebus closely parallels that which has been observed in Macaca. It is suggested that the different adult facial morphologies in the sooty mangabey and crab-eating macaque are the result of changes in the rates of remodelling events that may be coupled with different patterns of sutural growth (which could not be studied by SEM).

Animals

The variability of patterns of sexual dimorphism in the hominoid skull.

Univariate and multivariate statistical analyses are applied to a number of cranial dimensions and angles from living hominoids in order to investigate the patterns of sexual dimorphism in these groups. Clear differences in patterns of cranial sexual dimorphisms are demonstrated not only between genera but also within a single species (Homo). These differences overlay the common finding of a sexual size difference in all groups. The results imply that caution is required in using the sexual dimorphisms of living hominoids as models for those anticipated in fossils.

Animals

Treatment of rapidly progressive glomerulonephritis due to Behçet's syndrome with intravenous cyclophosphamide.

A patient with Behçet's syndrome developed hematuria, proteinuria, and rapidly progressive, severe, renal failure. Renal biopsy confirmed the presence of crescentic, necrotizing glomerulonephritis. Treatment with intravenous corticosteroids and oral cyclophosphamide (CTX) failed to arrest the decline in renal function. Intravenous pulse CTX was administered monthly for four treatment cycles with consequent improvement and stabilization of renal function, albeit at a markedly depressed glomerular filtration rate. The literature of case reports concerning crescentic glomerulonephritis in Behçet's syndrome is briefly reviewed, and fails to provide a uniformly accepted method of treating this rare complication. Intravenous CTX may prove to be another therapeutic option for rapidly progressive glomerulonephritis in the setting of Behçet's syndrome.

Behcet Syndrome

Characterization of dodecylphosphocholine/myelin basic protein complexes.

The stoichiometry of myelin basic protein (MBP)/dodecylphosphocholine (DPC) complexes and the location of protein segments in the micelle have been investigated by electron paramagnetic resonance (EPR), ultracentrifugation, photon correlation light scattering, 31P, 13C, and 1H nuclear magnetic resonance (NMR), and electron microscopy. Ultracentrifugation measurements indicate that MBP forms stoichiometrically well-defined complexes consisting of 1 protein molecule and approximately 140 detergent molecules. The spin-labels 5-, 12-, and 16-doxylstearate have been incorporated into DPC/MBP aggregates. EPR spectral parameters and 13C and 1H NMR relaxation times indicate that the addition of MBP does not affect the environment and location of the labels or the organization of the micelles except for a slight increase in size. Previous results indicating that the protein lies primarily near the surface of the micelle have been confirmed by comparing 13C NMR spectra of the detergent with and without protein with spectra of protein/detergent aggregates containing spin-labels. Electron micrographs of the complexes taken by using the freeze-fracture technique confirm the estimated size obtained by light-scattering measurements. Overall, these results indicate that mixtures of MBP and DPC can form highly porous particles with well-defined protein and lipid stoichiometry. The structural integrity of these particles appears to be based on protein-lipid interactions. In addition, electron micrographs of aqueous DPC/MBP suspensions show the formation of a small amount of material consisting of large arrays of detergent micelles, suggesting that MBP is capable of inducing large changes in the overall organization of the detergent.

Animals

NMR studies of myelin basic protein. XIII. Assignment of histidine residues in rabbit, bovine and porcine proteins.

Myelin basic protein from three species (rabbit, cow and pig) and peptides from enzymatic digests or cleavage of the proteins have been examined in aqueous solutions by proton nuclear magnetic resonance (NMR) at 400 MHz. The epsilon 1-CH and delta 2-CH resonances of all the histidine residues in the three proteins have been assigned and the pK values have been measured. The heterogeneity of chemical shifts among these resonances can be variously ascribed to persistent localized secondary structures and to effects arising from charged side-chains, particularly those of aspartic acid residues, and from side-chains of aromatic moieties.

Animals

Conformation of two antigenic regions in myelin basic protein.

Four different regions of myelin basic protein from various species have been reported to be the antigenic sites (epitopes) for seven monoclonal antibodies evoked in rats or mice by guinea pig or monkey basic protein. The structures of the epitopes located in the amino-terminal region and in the eight-residue sequence including S-133, were examined by proton n. m. r at 400 MHz in aqueous solutions of peptides obtained by enzymatic cleavage of the rabbit protein. The data suggest conformational similarities between the two regions.

Amino Acid Sequence

N.m.r. studies of myelin basic protein. Conformation of a peptide that is an antigenic determinant for B-cell reactivity.

The peptide Gly-Arg-Ala-Ser-Asp-Tyr-Lys-Ser, derived from myelin basic protein (MBP), is part of an epitope to monoclonal antibodies to human MBP. Its conformation has been studied in aqueous solution by high-resolution one- and two-dimensional 1H and 13C n.m.r. Two-dimensional correlated spectroscopy, pH titrations and one-dimensional spin-decoupling techniques were employed to assign the spectra observed from both nuclei. Amide proton temperature coefficients, coupling constants, 13C spin-lattice relaxation times and nuclear-Overhauser-effect data provide evidence that the solution conformations of the octapeptide include a type-II beta-turn with a hydrogen bond between the CO group of Arg2 and the NH group of Asp5. The results are discussed in view of a possible conformation of the antibody receptor site.

Antibodies, Monoclonal

Proton-n.m.r. study of interaction of myelin basic protein with a monoclonal antibody.

Proton n.m.r. at 400 MHz has been applied to study the interactions of bovine or porcine myelin basic protein (b- or p-MBP) with a monoclonal antibody to human (h-) MBP. The antibody, an IgG immunoglobulin that contains a sequential epitopic region, cross-reacts with b-MBP but not with p-MBP, the presumed epitope being identical in h- and b-MBP. N.m.r. spectra were recorded from the Fab fragment of the antibody and for mixtures of Fab and MBP at various molar ratios. The n.m.r. spectrum of MBP in the mixture consists mostly of well resolved peaks against a broad background due to the Fab. With b-MBP, but not p-MBP, specific interactions are observed at the residue tyrosine-135, which is part of the epitopic sequence. Other interactions occur between the Fab and both b- and p-MBP at residues distant from the epitopic region. Standard radioassay techniques were employed to calculate the binding constants of both basic proteins with the immunoglobulin. The binding constant, Kb, for IgG to column-immobilized b-MBP at 298K is (0.95 +/- 0.07) X 10(7) dm3/mol. The value of Kb decreases with the ionic strength of the medium, suggesting a coulombic interaction between antigen and antibody. N.m.r. spectra were also measured for mixtures of the Fab fragment and peptides containing the epitopic site, with results in agreement with those for the whole protein.

Antibodies, Monoclonal

Infant feeding and subsequent risk of atopic eczema.

An attempted controlled trial of exclusively breast fed neonates with atopic parents, to assess the effectiveness of breast feeding in preventing atopic allergy, was not successfully achieved. Analysis of the data as an observational study, however, provided evidence that breast feeding offers some protection against eczema in genetically vulnerable infants. Feeds of soya preparations were associated with eczema as often as cows' milk based feeds.

Age Factors

Interaction of myelin basic protein with micelles of dodecylphosphocholine.

Interactions of myelin basic protein (MBP) and peptides derived from it with micelles of dodecylphosphocholine (DPC) and perdeuterated DPC have been studied by proton nuclear magnetic resonance (NMR) at 400 MHz and by circular dichroism (CD). When MBP binds to DPC micelles, it acquires about 18% alpha-helicity. The CD spectra of various peptides derived by cleavage of MBP indicate that a major alpha-helical region occurs in residues 85-99 just before the sequence of three prolyl residues 100-102. From line broadenings by fatty acid spin-labels in the micelles and from changes in chemical shifts, the NMR data identify specific residues in MBP that participate in lipid binding. One such sequence is an alpha-helical region from residues 85 to 95, and others occur around methionine-21 and between residues 117 and 135. The different effects of C5, C12, and C16 spin-labels suggest that some segments of the protein may penetrate beyond the dipolar interfacial region of the micelles into the hydrophobic interior, but no part of the protein is protected by the micelles against rapid exchange of its amide groups with the aqueous environment. Even at a lipid to protein molar ratio of 200/1, most NMR resonances from side chains of amino acid residues are not appreciably broadened, suggesting that much of the polypeptide remains highly mobile.

Animals

NMR studies of myelin basic protein. IX. Complete assignments of the tyrosine residues by proton NMR of proteins from six species.

All the proton resonances from the tyrosine residues are assigned in 400 MHz NMR spectra in aqueous solution of myelin basic proteins from human, cow, pig, rabbit, rat (small protein) and chicken. Assignments are based on species comparisons, spectra of enzymatic cleavage products of the basic protein, pH titrations, broadening effects of Gd(III), and nuclear Overhauser effects. The mobile extended polypeptide chain structure of the protein facilitates the detection of interactions between nearest neighbors. Evidence is found for reverse turns in the structure in regions of encephalitogenic determinants.

Animals

NMR studies of myelin basic protein. X. Conformation of a determinant encephalitogenic in the rabbit.

Residues 67 to 75 in myelin basic protein from several species comprise the sequence Thr-His-Tyr-Gly-Ser-Leu-Pro-Gln-Lys that acts as an encephalitogenic determinant in the rabbit. Proton magnetic resonance spectra of human, bovine and porcine proteins display nuclear Overhauser effects between the delta-CH of Tyr-69 and the delta-CH3 of Leu-72, which indicate reverse-turn conformations about the Gly-Ser residues. This effect occurs also in physiological saline solution at pH 6.0 but in dimethylsulfoxide solution the nuclear Overhauser effect disappears. Circular dichroism indicates that the protein when bound to ganglioside micelles acquires 30-40% alpha-helical conformation, but the reverse turn still persists in the sequence of the rabbit encephalitogen. These results suggest that the encephalitogenic region of the protein remains at the aqueous interface of the micelles.

Amino Acid Sequence

Conformations of P2 protein of peripheral nerve myelin by nuclear magnetic resonance spectroscopy.

High-resolution 1H NMR spectra of P2 protein from bovine peripheral nerve myelin indicate that the protein contains a high degree of tertiary structure in aqueous solution. Denaturation of the protein in urea solutions is a multi-step process. Binding of lysophosphatidylcholine micelles to the protein causes a conformational change and a broadening of NMR peaks from side chains of aromatic amino acid and methionine residues, with much less effect on upfield methyl resonances.

Animals