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1.
G F Watts W Ahmed J Quiney R Houlston P Jackson C Iles B Lewis 《BMJ (Clinical research ed.)》1988,296(6617):235-237
The plasma lipid and lipoprotein responses to two modified isoenergetic diets including meat were studied in 15 free living men with hyperlipidaemia (mean plasma cholesterol and triglyceride concentrations 8·1 and 3·4 mmol/l). A reference diet (diet A, 42% energy from fat, ratio of polyunsaturated to saturated fatty acids (P:S ratio) 0·2) was compared with a fat reduced diet (diet B, 35% energy from fat, P:S ratio 0·5) and with a further fat modified diet supplemented with fibre (diet C, 27% energy from fat, P:S ratio 1·0). Daily intake of meat and meat products (180 g/day) was the same in each dietary period; that in diet A had a fat content typical of the average British diet, whereas that in diets B and C was based on very lean meat and meat products. During consumption of diet B the plasma cholesterol concentration fell by 8·6% and low density lipoprotein cholesterol by 11%. During consumption of diet C plasma cholesterol fell by 18·5% and low density lipoprotein cholesterol by 23·8%. Triglyceride and high density lipoprotein cholesterol concentrations and body weight did not change appreciably during the study.A modified diet including a moderate amount of lean meat and meat products is compatible with a reduced lipoprotein mediated risk of atherosclerotic heart disease. 相似文献
2.
Trimethyloxonium modification of single batrachotoxin-activated sodium channels in planar bilayers. Changes in unit conductance and in block by saxitoxin and calcium 总被引:13,自引:9,他引:4 下载免费PDF全文
Single batrachotoxin-activated sodium channels from rat brain were modified by trimethyloxonium (TMO) after incorporation in planar lipid bilayers. TMO modification eliminated saxitoxin (STX) sensitivity, reduced the single channel conductance by 37%, and reduced calcium block of inward sodium currents. These effects always occurred concomitantly, in an all-or-none fashion. Calcium and STX protected sodium channels from TMO modification with potencies similar to their affinities for block. Calcium inhibited STX binding to rat brain membrane vesicles and relieved toxin block of channels in bilayers, apparently by competing with STX for the toxin binding site. These results suggest that toxins, permeant cations, and blocking cations can interact with a common site on the sodium channel near the extracellular surface. It is likely that permeant cations transiently bind to this superficial site, as the first of several steps in passing inward through the channel. 相似文献
3.
Refined genetic localization for central core disease 总被引:4,自引:3,他引:1
J. C. Mulley H. M. Kozman H. A. Phillips A. K. Gedeon J. A. McCure D. E. Iles R. G. Gregg K. Hogan F. J. Couch D. H. MacLennan E. A. Haan 《American journal of human genetics》1993,52(2):398-405
Central core disease (CCO) is an autosomal dominant myopathy clinically distinct from malignant hyperthermia (MHS). In a large kindred in which the gene for CCO is segregating, two-point linkage analysis gave a maximum lod score, between the central core disease locus (CCO) and the ryanodine receptor locus (RYR1), of 11.8, with no recombination. Mutation within RYR1 is responsible for MHS, and RYR1 is also a candidate locus for CCO. A combination of physical mapping using a radiation-induced human-hamster hybrid panel and of multipoint linkage analysis using the Centre d'Etude du Polymorphisme Humain families established the marker order and sex-average map distances (in centimorgans) on the background map as D19S75–(5.2)–D19S9–(3.4)–D19S191–(2.2)–RYR1–(1.7)–D19S190–(1.6)-D19S47–(2.0)–CYP2B. Recombination was observed between CCO and the markers flanking RYR1. These linkage data are consistent with the hypothesis that CCO and RYR1 are allelic. The most likely position for CCO is near RYR1, with a multipoint lod score of 11.4, in 19q13.1 between D19S191 and D19S190, within the same interval as MHS (RYR1). 相似文献
4.
J. P. Monson R. M. Henderson J. A. Smith R. A. Iles M. Faus-Dader N. D. Carter R. Heath H. Metcalfe R. D. Cohen 《Bioscience reports》1984,4(10):819-825
In perfused rat liver a decrease of cytosol pH, determined with pH-sensitive microelectrodes7 from 7.2 to 6.85 is associated with a 50% fall in ureogenesis from ammonium chloride. In isolated rat hepatocytes the fall in ureogenesis due to acidosis is associated with decrease in the mitochondrial and cytosolic concentration of citrulline. Limitation of carbamoyl phosphate synthesis and thus citrulline supply could be responsible for the inhibition of ureogenesis observed. 相似文献
5.
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7.
The human ryanodine receptor gene: Its mapping to 19q13.1, placement in a chromosome 19 linkage group, and exclusion as the gene causing myotonic dystrophy 总被引:9,自引:1,他引:9 下载免费PDF全文
Alex E. MacKenzie Robert G. Korneluk Francesco Zorzato Junichi Fujii Michael Phillips David Iles B Wieringa Suzanne Leblond Jane Bailly Huntington F. Willard Catherine Duff Ronald G. Worton David H. MacLennan 《American journal of human genetics》1990,46(6):1082-1089
The recent cloning of cDNA encoding the Ca++ release channel (ryanodine receptor) of human sarcoplasmic reticulum has enabled us to use somatic cell hybrids to localize the ryanodine receptor gene (RYR) to the proximal long arm of human chromosome 19. Studies with additional hybrids containing deletions or translocations in chromosome 19 enabled us to localize RYR to 19q13.1 in a region distal to GPI/MAG and proximal to D19S18/DNF11. On the basis that the myotonic dystrophy (DM) locus maps near this region and that myotonia could result from a defect in the ryanodine receptor, we examined the linkage between the DM locus and RYR. Our results, showing several DM-RYR recombinants, rule out an RYR defect as the cause of DM. However, localization of RYR to a region of human chromosome 19 which is syntenic to an area of pig chromosome 6 containing the HAL gene responsible for porcine malignant hyperthermia supports the candidacy of RYR for this disorder. 相似文献
8.
Iles KE Dickinson DA Watanabe N Iwamoto T Forman HJ 《Free radical biology & medicine》2002,32(12):1304-1313
Reactive oxygen species released during the respiratory burst are known to participate in cell signaling. Here we demonstrate that hydrogen peroxide produced by the respiratory burst activates AP-1 binding. Stimulation of the macrophage cell line NR8383 with respiratory burst agonists ADP and C5a increased AP-1 binding activity. Importantly, this increase in binding was blocked by catalase, confirming mediation by endogenous H2O2. Moreover, exogenously added H2O2 mimicked the agonists, and also activated AP-1. Antibodies revealed that the activated AP-1 complex is composed predominantly of c-Fos/c-Jun heterodimers. Treatment of the cells with ADP, C5a and H2O2 (100 μM) all increased the phosphorylation of c-Jun. c-Fos protein was increased in cells treated with C5a or high dose (200 μM) H2O2, but not in cells treated with ADP. The MEK inhibitor, PD98059, partially blocked the C5a-mediated increase in AP-1 binding. A novel membrane-permeable peptide inhibitor of JNK, JNKi, also inhibited AP-1 activation. Together these data suggest that C5a-mediated AP-1 activation requires both the activation of the ERK and JNK pathways, whereas activation of the JNK pathway is sufficient to increase AP-1 binding with ADP. Thus, AP-1 activation joins the list of pathways for which the respiratory burst signals downstream events in the macrophage. 相似文献
9.
Extreme differences in rates of molecular evolution of foraminifera revealed by comparison of ribosomal DNA sequences and the fossil record 总被引:5,自引:3,他引:5
Pawlowski J; Bolivar I; Fahrni JF; de Vargas C; Gouy M; Zaninetti L 《Molecular biology and evolution》1997,14(5):498-505
Foraminifera have one of the best known fossil records among the
unicellular eukaryotes. However, the origin and phylogenetic relationships
of the extant foraminiferal lineages are poorly understood. To test the
current paleontological hypotheses on evolution of foraminifera, we
sequenced about 1,000 base pairs from the 3' end of the small subunit rRNA
gene (SSU rDNA) in 22 species representing all major taxonomic groups.
Phylogenies were derived using neighbor- joining, maximum-parsimony, and
maximum-likelihood methods. All analyses confirm the monophyletic origin of
foraminifera. Evolutionary relationships within foraminifera inferred from
rDNA sequences, however, depend on the method of tree building and on the
choice of analyzed sites. In particular, the position of planktonic
foraminifera shows important variations. We have shown that these changes
result from the extremely high rate of rDNA evolution in this group. By
comparing the number of substitutions with the divergence times inferred
from the fossil record, we have estimated that the rate of rDNA evolution
in planktonic foraminifera is 50 to 100 times faster than in some benthic
foraminifera. The use of the maximum-likelihood method and limitation of
analyzed sites to the most conserved parts of the SSU rRNA molecule render
molecular and paleontological data generally congruent.
相似文献
10.
Jolanda?HM?van Bilsen Josée?PA?Wagenaar-Hilbers Maarten?JF?van der Cammen Mariska?EA?van Dijk Willem?van Eden Marca?HM?WaubenEmail author 《Arthritis research & therapy》2002,4(4):R2
We have recently found that matrix metalloproteinases (MMPs) are targets for T-cell and B-cell reactivity in experimental
arthritis. In the present article, we investigate whether modulation of MMP-specific T-cell responses could influence the
course of adjuvant arthritis (AA). Lewis rats were treated nasally with MMP peptides prior to or after AA induction. Administration
of the MMP-10 or the MMP-16 peptide prior to AA induction reduced the arthritic symptoms. In contrast, administration of the
MMP-10 peptide after AA induction aggravated the arthritic symptoms. The present study shows the possible usefulness of MMP
peptides for immunotherapy. However, a clear understanding of proper timing of peptide administration is crucial for the development
of such therapies. 相似文献