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S Jones

Publications and source records attributed to S Jones.

At least 307 records · Page 17Linked to original sources
PubMed1996

Mucosal addressin cell adhesion molecule-1: a structural and functional analysis demarcates the integrin binding motif.

The leukocyte integrin receptor, alpha 4 beta 7, and the mucosal addressin cell adhesion molecule-1 (MAdCAM-1) are postulated to be important in regulating lymphocyte trafficking to normal intestine. Here we provide the first description of MAdCAM-1 expression in inflamed intestine. Using mouse models of experimentally induced colitis, we show a concordant increase in MAdCAM-1 expression associated with increased cellular infiltrates in areas of intestinal inflammation. To understand more of the molecular nature of the interactions between MAdCAM-1 and its leukocyte ligand, the alpha 4 beta 7 integrin receptor, we have analyzed the structural and functional properties of chimeric recombinant MAdCAM-1 proteins in vitro. Using site-directed mutagenesis and molecular modeling, we demarcate the alpha 4 beta 7 binding motif as three linear residues within the C-D loop in the first domain of MAdCAM-1. Mutation of residue L40, D41, or T42 in the first domain completely abrogates alpha 4 beta 7+ cell binding and cellular activation. Mutagenesis of other residues in the first domain do not impact these functions. We have modeled peptides based on the predicted structure of the alpha 4 beta 7 integrin binding motif on MAdCAM-1 and are able to show specific and selective blocking of cell binding. These observations suggest that the amino acid residues LDT on MAdCAM-1 play a role in the interaction with alpha 4 beta 7 in cell adherence and cell activation.

Amino Acid Sequence↗
PubMed1996

Expression of rat neuronal nitric oxide synthase in Saccharomyces cerevisiae.

The rat neuronal nitric oxide synthase (nNOS) cDNA was expressed in Saccharomyces cerevisiae under the control of a hybrid PGK/GAL promoter, PAL. Galactose induction resulted in the production of a soluble 160 kDa protein that was recognised by anti-neuronal NOS antibody. NOS activity was detected by the conversion of [3H]arginine to [3H]citrulline and required the addition of the cofactors, calmodulin and tetrahydrobiopterin. The activity was inhibited by the arginine analogues NG-nitro-L-arginine and NG-nitro-L-arginine methyl ester.

Animals↗
PubMed1996

Dental health related behaviours in toddlers in low and high caries areas in St Helens, north west England.

The aim of this investigation was to compare the dental health behaviour of toddlers in low caries (A) and high caries (B) communities in St Helens. Parents of 60 children aged between 17 and 20 months in community A, and 68 in community B were interviewed at home. Using 24-hour dietary recall, sugar intake was recorded as sugar episodes-a sugar episode being a half-hour period during which any amount of non-milk extrinsic sugars (NMES) was consumed. Exposure to fluoride was recorded according to the number of times fluoride toothpaste was used and whether a fluoride supplement was given in the 24-hour period. The median sugar episode score for community A was 6 per 24-hour period (interquartile range 5 to 8), compared with 10.5 (7 to 13) for community B. Sixty per cent of parents in community A compared with 37% in community B reported brushing their child's teeth twice daily with fluoride toothpaste. The respective figures for use of fluoride supplements were 12% and 6%. It is concluded that patterns of dental health behaviour are established early in children's lives, and that marked differences exist between communities within the same district. Recommendations are made for oral health promotion policy.

Dental Care↗
PubMed1996

Generation of a free radical from calphostin C by microsomal cytochrome P450 reductase in rat and human liver.

Calphostin C (cal C) is a potent and specific protein kinase C inhibitor that is thought to be photoactivated to generate a reactive perylenesemiquinone free radical intermediate. In this electron spin resonance spectrometry study, we show, for the first time, an enzymatic light-independent mechanism of cal C free radical formation. Such a free radical was generated in liver microsomes from rat and humans, and its formation was dependent on the presence of NADPH, functional microsomes, and protein and cal C concentrations. Inhibitor and purified enzyme studies showed that cytochrome P450 reductase is responsible for the cal C free radical observed, which is probably a perylenesemiquinone.

Animals↗
PubMed1996

Principles of protein-protein interactions.

This review examines protein complexes in the Brookhaven Protein Databank to gain a better understanding of the principles governing the interactions involved in protein-protein recognition. The factors that influence the formation of protein-protein complexes are explored in four different types of protein-protein complexes--homodimeric proteins, heterodimeric proteins, enzyme-inhibitor complexes, and antibody-protein complexes. The comparison between the complexes highlights differences that reflect their biological roles.

Animals↗
PubMed1996

Contrast cine left ventriculography: comparison of two pigtail catheter shapes and analysis of factors determining the final quality.

Ventricular arrhythmias or inadequate opacification of the ventricular cavity during contrast-cine left ventriculography frequently interfere with evaluation of regional wall motion, ejection fraction or mitral regurgitation. In this prospective, randomized study traditional (straight) pigtail catheter was compared with a new, large loop pigtail catheter (both 6 French, large lumen) in terms of the quality of the cine left ventriculograms. Straight (Group I) and curved pigtail (Group II) groups were further subdivided randomly into a preset (13 cc per second for 3 seconds with a pressure rise time of 0.5 seconds) injection rate (Group IA, n = 46, and Group IIA, n = 48) or operator definded injection rate (Group IB, n = 49, and Group IIB, n = 45) subgroups. The ventricular tachycardia and couplets occurred at similar frequency among the groups. The curved pigtail subgroups showed significantly more frequent catheter induced mitral regurgitation. However, the opacification and overall quality of the left ventriculograms were distributed similarly between the groups. Because the catheter type and injection protocol did not affect the left ventriculogram quality in our study, variables determining opacification and overall quality rating are analyzed in the overall group of 190 patients. Left ventricular opacification was excellent in 72, acceptable in 108 and marginal in 10 patients. The patients with marginal opacification were significantly heavier (P = .004) with larger left ventricular enddiastolic volumes (P = .019), and smaller amount of contrast volume per enddiastolic volume (P = .005) and kilogram body weight (P = .003). The overall quality of left ventriculograms were excellent in 38, acceptable in 133, and marginal in 19 patients. The patients with excellent left ventriculograms were significantly younger (P = .019) and slightly less heavy (P = 0.09). Significantly more female patients were also in this group (P = .036). Ventricular tachycardia was the most common cause of unsatisfactory left ventriculograms. In the RAO view, deeper (more apical) placement of the catheter was associated with higher incidence of ventricular tachycardia (53%). The most "silent" area was the posterobasal area. In conclusion, the perfect left ventriculogram remains to be an elusive goal in routine clinical practice. When using 6F highflow pigtail catheters and nonionic contrast agents, more basal catheter position and higher contrast volume increase the quality of the left ventriculograms.

Adult↗
PubMed1996

MMPI-2 patterns in African-American females.

Researchers have reported conflicting conclusions about the relation of the MMPI (MMPI-2) clinical scale elevations and race. Consequently, this study examined the concurrent validity of the MMPI-2 in evaluating African-American females. Seventy-eight (78) African American college student volunteers were administered the MMPI-2, along with other measures of personality, achievement, and coping style. Scores revealed 76% of the sample had elevated profiles. Subjects were divided into three groups based on frequency of clinical scale code type. Subjects with the 5/9 profile elevations functioned as well as normals on measures of coping skills and mood disorders. Discussion emphasizes the importance of clinical interpretation of MMPI data in research programs and the relationship of the data to coping style.

Adaptation, Psychological↗
PubMed1996

Lesion discrimination in optic neuritis using high-resolution fat-suppressed fast spin-echo MRI.

Fast spin-echo (FSE) is a new sequence with acquisition times currently down to one-sixteenth of those obtained with conventional spin-echo sequences, which allows high-resolution (512 x 512 matrix) images to be acquired in an acceptable time. We compared the higher resolution of FSE with the medium resolution of a short inversion-time inversion-recovery (STIR) sequence in depicting the optic nerves of healthy controls and patients with optic neuritis. Optic nerve MRI examinations were performed in 18 patients with optic neuritis and 10 normal controls. Two sequences were obtained coronally: fat-suppressed FSE (FSE TR 3250 ms/TEef 68 ms, echo-train length 16, 4 excitations, 24 cm rectangular field of view, 3 mm interleaved contiguous slices, in-plane resolution 0.5 x 0.5 mm) and STIR (TR 2000 ms/TE 50 ms/TI 175 ms, in-plane resolution 0.8 x 0.8 mm, slice thickness 5 mm). FSE demonstrated much more anatomical detail than STIR, e.g. distinction of optic nerve and sheath. Lesions were seen in 20 of 21 symptomatic nerves using FSE and in 18 of 21 using STIR. Nerve swelling or partial cross-sectional lesions of the optic nerve were each seen only on FSE in 3 cases. Fat-suppressed FSE imaging of the optic nerve improves anatomical definition and increases lesion detection in optic neuritis.

Adult↗
PubMed1996

Comparative profile of novel potent bradykinin antagonists at human B1 and B2 receptors.

We have undertaken a comparative pharmacological profile of novel bradykinin antagonists on human B1 and B2 receptor binding and functional assays. We found that there was an excellent correlation between binding and functional data for the compounds at the B1 receptor. In general, although there was a good correlation between the binding and functional data at the B2 receptor there was a greater degree of scatter in the correlation, particularly with compounds that possessed both B1 and B2 binding and antagonist activity. Of the compounds that were highly selective for the B2 receptor, CP-0597 had high binding activity but showed an unexpectedly low functional potency in the human ileum. The reason for this discrepancy is unclear. In general we found that binding activity with both the B1 and B2 antagonist compounds correlated well with their functional activity.

Adult↗
PubMed1996

Three-dimensional cultures of fetal mouse cerebral cortex in a collagen matrix.

A 3-dimensional tissue culture system for fetal mouse cerebral cortex was devised in order to study neuronal migration in vitro. The dorsolateral cerebral mantle of E16 mouse was dissected into slices of 250-350 microns. Explants were embedded in a matrix formed of thin layers of collagen gel above and below the tissue. The optimal conditions for maintaining explant survival within the matrix included (1) placing the explants on membrane inserts with large (70 microns) pores which permits access of nutrient to the cultures from below as well as from above, and (2) intermittent exposure of the explants to ambient oxygen (20% O2 with 5% CO2) by partially covering the upper surface with medium and placing the cultures on a rocking platform. Thickness measurements of serially sectioned intact cultures at 6 days in vitro ranged from 128 to 210 microns (average: 172 microns). In intact explants, maintained for up to 14 days in vitro, the preservation of neurones, neuronal subtypes and glia was confirmed with immunofluorescence staining for neurone-specific nucleoprotein (NeuN), microtubule-associated protein (MAP-2), a glutamate receptor subunit (GluR 1), GABA and glial fibrillary acidic protein (GFAP) respectively. Some cortical differentiation was obtained in vitro, at 6 days, with the development of upper and lower cortical layers, similar to that seen in an P1 animal.

Animals↗
PubMed1996

Role of magnetic resonance imaging in the diagnosis of osteomyelitis in diabetic foot infections.

PURPOSE: The role of magnetic resonance imaging (MRI) in the diagnosis of osteomyelitis in foot infections in diabetics was investigated. The accuracy, sensitivity, and specificity of MRI, plain radiography, and nuclear scanning were determined for diagnosing osteomyelitis, and a cost comparison was made. METHODS: Twenty-seven patients with diabetic foot infections were studied prospectively. All patients underwent MRI and plain radiography. Twenty-two patients had technetium bone scans, and 19 patients had Indium scans. Nineteen patients had all four tests performed. Patients with obvious gangrene or a fetid foot were excluded. RESULTS: The diagnosis of osteomyelitis was established by pathologic specimen (n = 18), bone culture (n = 3), or successful response to medical management (n = 6). Osteomyelitis was confirmed in nine of the pathologic specimens. The diagnostic sensitivity, specificity, and accuracy for MRI was 88%, 100%, and 95%, respectively, for plain radiography it was 22%, 94%, and 70%, respectively, for technetium bone scanning it was 50%, 50%, and 50%, respectively, and for Indium leukocyte scanning it was 33%, 69%, and 58%, respectively. The data were analyzed statistically with the two-tailed Fisher's exact test. MRI was the only test that was statistically significant (p < 0.01). CONCLUSIONS: MRI appeared to be the single best test for the diagnosis of osteomyelitis associated with diabetic foot infections. It had a better diagnostic accuracy than conventional modalities and appeared to be more cost-effective than the frequently used Indium scan.

Adult↗