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71.
72.
B L Reid 《Medical hypotheses》1989,29(2):127-144
A previous paper in this series described experiments and observations which could have been produced by properties derived from the quality of laboratory space. In particular, action at a distance was of commonplace occurrence. It was argued that support for this idea was forthcoming from two recent developments in physics, that of non-linear thermodynamics and that of quantum mechanics followed by quantum electrodynamics. The first permitted the concept of a formative or structuring role for energy permeating matter the second the concept of a structure and function for space. One of these functions was to provide for the creation of subatomic particles and thus of matter. This creativity is achieved from an origin in a non-observable world where the equations have no terms for distance or time. The demonstration of the insignificance of distance in the experiments reported using both crystal and biological growth was used to infer that events in this growth process were similarly preceeded by events in the non-observable world. The implications of such an origin for growth and new growth are discussed. 相似文献
73.
Rawatmal B. Surana Syed K. Rafi Kevi L. Christopher Thomas J. Reid Raymond B. Weiss 《Clinical genetics》1995,47(6):321-323
An apparently balanced de novo reciprocal translocation t(5;21) (q13;q22) was demonstrated in a girl with acrobrachycephaly, ventriculomegaly, pulmonary stenosis and anal malformation. The possible relationships between her karyotype and malformations are discussed. 相似文献
74.
R B Rothman V Bykov A Reid B R De Costa A H Newman A E Jacobson K C Rice 《Neuropeptides》1988,12(3):181-187
Norbinaltorphimine (nor-BNI) is a bifunctional reagent developed as a selective antagonist of the kappa opioid receptor. In this paper we examined the in vitro selectivity of nor-BNI, 6-desoxy-6 beta-fluoronaltrexone (cycloFOXY), and the enantiomer of cycloFOXY, among opioid receptor subtypes. Nor BNI exhibited the highest affinity for kappa binding sites labeled by 3H-U69593 (Ki = 1.8nM), and was 27- to 29-fold less potent at mu and delta binding sites. In contrast, cycloFOXY had the highest affinity for mu binding sites (Ki = 2.62 nM), and bound to kappa and delta binding sites with Ki's of 9.3 nM and 89 nM, respectively. The enantiomer of cycloFOXY, did not inhibit binding even at concentrations greater than 10 microM, validating in part the use of 18F-labeled (+)-cycloFOXY to estimate "non-specific binding" in positron emission tomography. Additionally, we report that (S,S)-U50 488 and (R.R)-U50 488 bind to kappa binding sites labeled by 3H-U69 593 with Ki's of 0.89 nM and 299 nM, respectively. 相似文献
75.
Imaging of cerebral blood flow markers in Huntington''s disease using single photon emission computed tomography.
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I C Reid J A Besson P V Best P F Sharp H G Gemmell F W Smith 《Journal of neurology, neurosurgery, and psychiatry》1988,51(10):1264-1268
Single photon emission computed tomography (SPECT) imaging of six Huntington's disease patients revealed a striking reduction in regional uptake of cerebral blood flow markers in vivo. Similar changes were found in one patient with "early stage" disease. The findings are compared with parallel magnetic resonance imaging (MRI) studies, and in one case, results of postmortem examination. 相似文献
76.
Sternson LA Stobaugh JF Reid TJ de Montigny P 《Journal of pharmaceutical and biomedical analysis》1988,6(6-8):657-668
The bioanalysis of drugs used in the management of cancer is often complicated by the lack of selectivity and sensitivity. Chemical derivatization of these drugs prior to their chromatographic analysis represents a viable strategy to improve chromatographic resolution and to enhance detectability. This review provides examples of how this approach can meet these objectives. Derivatization of racemic cyclophosphamide with a chiral acylating agent, following hydroxyalkylation to introduce a reactive centre into the molecule, provides the basis for its stereospecific analysis. The analysis of dianhydrogalactitol is described, in which diethyldithiocarbamate is used as a nucleophilic derivatizing agent that improves chromatographic behaviour and analytical sensitivity. The final example that is described is the design and preparation of improved fluorogenic reagents (o-phthalaldehyde analogues) for the derivatization of peptides and application of these reagents to the trace analysis of leu-enkephalin in plasma. 相似文献
77.
L. J. Dowie J. E. Smith A. J. MacGilchrist R. Fraser J. W. Honour J. L. Reid C. J. Kenyon 《European journal of clinical pharmacology》1988,35(6):625-629
Summary The site of omeprazole inhibition of adrenal steroidogenesis has been sought in vivo by analyzing the patterns of urinary steroid metabolite excretion after 6 days of treatment with placebo/omeprazole.Excretion rates of androsterone, aetiocholanolone, dehydroepiandrosterone, 11 hydroxyandrosterone, tetrahydrocortisone, tetrahydrocortisol and cortolone were reduced, indicating a block at an early step in steroidogenesis, possibly cholesterol side-chain cleavage. In vitro studies have confirmed this finding by measuring conversion of added precursors to cortisol in isolated bovine adrenocortical cells. Cortisol synthesis from added 20 hydroxycholesterol was inhibited by 83% in the presence of 100 µg omeprazole/ml. Conversion from pregnenolone and progesterone and their 17 hydroxylated derivatives was inhibited by 20–40% whereas cortisol production from added 11 deoxycortisol was not affected.These data suggest that omeprazole primarily inhibits cholesterol cleavage and does not inhibit 3 hydroxysteroid dehydrogenase, 17 hydroxylase or 11 hydroxylation; 21 hydroxylase activity may be marginally attenuated. 相似文献
78.
Fat mass is an important determinant of whole body bone density in premenopausal women but not in men. 总被引:18,自引:0,他引:18
I R Reid L D Plank M C Evans 《The Journal of clinical endocrinology and metabolism》1992,75(3):779-782
We recently reported that total body fat mass is the principal determinant of bone density in normal postmenopausal women. We have now reexamined the relationships among these variables and lean mass in 68 healthy premenopausal women and 51 men. Areal bone density (BMD), fat mass, and lean mass were measured in total body scans by dual-energy, x-ray absorptiometry. In women, BMD was correlated with weight (r = 0.69), fat mass (r = 0.60), and lean mass (r = 0.55). In men, the respective correlations were 0.56, 0.26 (NS), and 0.51. Multiple regression analysis confirmed a codependence of female BMD on fat and lean masses, whereas male BMD was related only to lean mass. Because BMD is an areal not volumetric density, it is dependent on body size. The analysis was therefore repeated using BMD/height as an index of "true" density. Correlations with fat mass were little changed but those with lean mass were reduced (women) or eliminated (men). By multiple regression, female BMD/height was related to fat mass alone, and in men there was a borderline effect of fat (P = 0.05) but none of lean mass. As a second method to exclude a scale artifact, fat mass was expressed as percent body weight. It was related to BMD (r = 0.48) only in women. It is concluded that bone density is closely related to fat mass in premenopausal women, but less so in men. In both sexes, apparent relationships between BMD and lean mass are artifacts attributable to the use of areal density (which is dependent on body size) as a surrogate for volumetric density. The mechanism of this fat-bone density relationship is an important question to be addressed in bone biology. 相似文献
79.
Clonal growth of tumors on tissue-specific biomatrices and correlation with organ site specificity of metastases 总被引:6,自引:0,他引:6
We have found that neoplastic transformation alters the ability of cells to grow on substrata of tissue extracts, "biomatrices", enriched in extracellular matrix. Tumor cells were able to survive and grow at lower densities and on more types of biomatrices than normal cells. When plated at high densities (greater than 10(5) cells/60 mm dish), tumor cells attached with equal efficiency and grew at similar rates and to equivalent saturation densities on biomatrices derived from all tissues. However, at low (10(2)-10(4)/60-mm dish) seeding densities, the tumor cells grew only on certain types of biomatrix. For the various hepatoma and mammary carcinoma cell lines tested, the tissue specificity in clonal growth on biomatrices correlated with their organ site specificity for metastasis in vivo in immunosuppressed, athymic nude mice. Analysis of the effects of purified matrix components (adhesion proteins, collagens, glycosaminoglycans) indicated that only the glycosaminoglycans influenced density-dependent survival and growth of tumor cells with effects that differed with respect to the cell's metastatic potential. The results indicate that the ability of tumor cells to colonize specific tissues represents, in part, regulation of low density survival and growth by extracellular matrix and are suggestive that one of the matrix components responsible may be proteoglycans or their glycosaminoglycan chains. 相似文献
80.
Variations in Helicobacter pylori lipopolysaccharide to evade the innate immune component surfactant protein D 总被引:2,自引:0,他引:2
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Khamri W Moran AP Worku ML Karim QN Walker MM Annuk H Ferris JA Appelmelk BJ Eggleton P Reid KB Thursz MR 《Infection and immunity》2005,73(11):7677-7686
Helicobacter pylori is a common and persistent human pathogen of the gastric mucosa. Surfactant protein D (SP-D), a component of innate immunity, is expressed in the human gastric mucosa and is capable of aggregating H. pylori. Wide variation in the SP-D binding affinity to H. pylori has been observed in clinical isolates and laboratory-adapted strains. The aim of this study was to reveal potential mechanisms responsible for evading SP-D binding and establishing persistent infection. An escape variant, J178V, was generated in vitro, and the lipopolysaccharide (LPS) structure of the variant was compared to that of the parental strain, J178. The genetic basis for structural variation was explored by sequencing LPS biosynthesis genes. SP-D binding to clinical isolates was demonstrated by fluorescence-activated cell sorter analyses. Here, we show that H. pylori evades SP-D binding through phase variation in lipopolysaccharide. This phenomenon is linked to changes in the fucosylation of the O chain, which was concomitant with slipped-strand mispairing in a poly(C) tract of the fucosyltransferase A (fucT1) gene. SP-D binding organisms are predominant in mucus in vivo (P = 0.02), suggesting that SP-D facilitates physical elimination. Phase variation to evade SP-D contributes to the persistence of this common gastric pathogen. 相似文献