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61.
Howells LA 《Hormone research》2002,57(Z1):69-71
Adequate age-appropriate diabetes knowledge and skills are essential to the success of diabetes self- and parental care. Health professionals have a central role in providing diabetes education. A direct link between diabetes knowledge and diabetes regimen behaviour cannot be assumed. Health professionals have to help children and their parents to develop the emotional concept of 'self-efficacy for diabetes self-care', to ensure optimal diabetes control. 相似文献
62.
360 MHz PMR studies on the involvement of the Y-nucleoside in the conformation of 2''-OMeGpApApYpAppsi from torula yeast tRNAphe.
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360 MHz measurements of chemical shifts, 3J1'-2', and T1 as a function of temperature for various protons of the hexanucleotide 2'-OMeGpApApYpAppsi from torula yeast tRNAphe have revealed a unique involvement of the Yt base in the structure and conformation of this oligonucleotide. Whereas the adenosine residues in the anticodon triplet are relatively stable to temperature increase, the Yt readily undergoes destacking and a change in ribose conformation. The destacking most likely involves a torsional displacement of the Yt base occasioned by a rotation of the phosphate-ribose backbone. The possible relevance of this unusual behavior to the influence of the Yt residue in tRNA function in protein biosynthesis is discussed. 相似文献
63.
Active opiate binding sites have been solubilized from mammalian brain cell membranes. The presence of 0.5-0.1 M NaCl during treatment of membranes from rat brain, human frontal cortex, and bovine corpus striatum with glycodeoxycholate or digitonin resulted in the extraction of active opiate binding sites in yields ranging up to 43%. The criteria for solubility of the sites were their inability to sediment at 10(5) x g after 2 hr and their apparent molecular weight of 3- 4 x 10(5) as determined by gel filtration. The receptors in solution resemble the membrane-bound sites with respect to saturability, stereo-specificity, sensitivity to heat and reagents, and high affinity for opioid ligands. The interaction of solubilized sites with immobilized lectins was used to demonstrate the glycoprotein nature of the opiate receptor. Soluble receptors from all species studied were retained by wheat germ agglutinin(WGA)-agarose and could be specifically eluted with N-acetylglucosamine. No retention of solubilized material was observed with eight other lectins examined, including horseshoe crab lectin, a sialic acid specific agglutinin. The receptor protein eluted from WGA columns was enriched 25-50-fold over the crude soluble fraction. 相似文献
64.
Evaluation of the Applied Biosystems automated Taqman polymerase chain reaction system for the detection of meningococcal DNA 总被引:22,自引:0,他引:22
Guiver M Borrow R Marsh J Gray SJ Kaczmarski EB Howells D Boseley P Fox AJ 《FEMS immunology and medical microbiology》2000,28(2):173-179
In a period where the proportion of culture confirmed cases in the UK has been steadily declining, diagnosis by PCR has been used to increase the number of confirmed cases and provide additional epidemiological data. This report presents a comparative evaluation of the fluorogenic probe-based 5' exonuclease assay (Taqman) using the Perkin-Elmer Applied Biosystems automated sequence detection system 7700 with previously reported polymerase chain reaction enzyme-linked immunosorbent (PCR ELISA) assays for the detection of meningococcal DNA in CSF, plasma and serum samples. Taqman assays developed were based on the detection of a meningococcal capsular transfer gene (ctrA), the insertion sequence IS1106 and the sialytransferase gene (siaD) for serogroup B and C determination and compared with similar assays in a PCR ELISA format. The Taqman ctrA assay was specific for Neisseria meningitidis, however the IS1106 assay gave false positive reactions with a number of non-meningococcal isolates. Sensitivity of the Taqman ctrA, IS1106 and siaD assays testing samples from culture-confirmed cases were 64, 69 and 50%, respectively, compared with 26, 67 and 43% for the corresponding PCR ELISA assays. Improvements to the DNA extraction procedure has increased the sensitivity to 93 and 91% for the TaqMan ctrA and siaD assays, respectively, compared to culture confirmed cases. Since the introduction of Taqman PCR a 56% increase in laboratory confirmed cases of meningococcal disease has been observed compared to culture only confirmed cases. The developed Taqman assays for the diagnosis of meningococcal disease enables a high throughput, rapid turnaround of samples with considerable reduced risk of contamination. 相似文献
65.
66.
Sissi C Perdonà E Domenici E Feriani A Howells AJ Maxwell A Palumbo M 《Journal of molecular biology》2001,311(1):195-203
The conformational equilibria of the A subunit of DNA gyrase (GyrA), of its 59 kDa N-terminal fragment (GyrA59) and of the quinolone-resistant Ser-Trp83 mutant (GyrATrp83), were investigated in the presence of mono- and divalent metal ions and ciprofloxacin, a clinically useful antibacterial quinolone. The stability of the proteins was estimated from temperature denaturation, monitoring unfolding with circular dichroism spectroscopy. Two transitions were observed in GyrA and GyrATrp83, which likely reflect unfolding of the N and C-terminal protein domains. Accordingly, one thermal transition is observed for GyrA59.The melting profile of the GyrA subunit is dramatically affected by monovalent and divalent metal ions, both transitions being shifted to lower temperature upon increasing salt concentration. This effect is much more pronounced with divalent ions (Mg(2+)) and cannot be accounted for by changes in ionic strength only. The presence of ciprofloxacin shifts the melting transitions of the wild-type subunit to higher temperatures when physiological concentrations of Mg(2+) are present. In contrast, both the mutant protein and the 59 kDa fragment do not show evidence for quinolone-driven changes. These data suggest that ciprofloxacin binds to the wild-type subunit in an interaction that involves Ser83 of GyrA and that both C and N-terminal domains may be required for effective drug-protein interactions. The bell-shaped dependence of the binding process upon Mg(2+) concentration, with a maximum centred at 3-4 mM [Mg(2+)], is consistent with a metal-ion mediated GyrA-quinolone-interaction. Affinity chromatography data fully support these findings and additionally confirm the requirement for a free carboxylate to elicit binding of the quinolone to GyrA.We infer that the Mg(2+)-GyrA interaction at physiological metal ion concentration could bear biological relevance, conferring more conformational flexibility to the active enzyme. The results obtained in the presence of ciprofloxacin additionally suggest that the Mg(2+)-mediated quinolone binding to the enzyme might be involved in the mechanism of action of this family of drugs. 相似文献
67.
This paper presents a mechanism to vary the vigilance parameter in the RePART fuzzy neural network. This mechanism helps to smooth out the problem of category proliferation which affects ARTMAP-based networks. Empirical experiments show that the use of variable vigilance improves the performance of the RePART model while, at the same time, requiring a less complex structure. 相似文献
68.
W W Howells 《American journal of physical anthropology》1973,39(2):165-168
69.
Conclusions As a model for the behaviour of plutonium in bone, calcein data must be treated with some care. It does not label the same surfaces as plutonium which results in different distribution patterns at later times. However, it might be that if in man or a long lived animal, labelling occured over a period of weeks, so that most surfaces become labelled, the resultant distribution pattern at late times would more nearly model plutonium behaviour. The single biggest difference between the behaviour of the two substances is the build up of plutonium in the bone marrow, an effect seen only slightly with calcein. The other differences noted was the redeposition of plutonium, as a consequence of recycling of the radionuclide, maintaining a concentration of plutonium on endosteal surface. 相似文献
70.