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51.
52.
Kanchana Srisawat Katie Hesketh Matt Cocks Juliette Strauss Ben J. Edwards Paulo J. Lisboa Sam Shepherd Jatin G. Burniston 《Proteomics》2020,20(7)
The repeatability of dynamic proteome profiling (DPP), which is a novel technique for measuring the relative abundance (ABD) and fractional synthesis rate (FSR) of proteins in humans, is investigated. LC–MS analysis is performed on muscle samples taken from male participants (n = 4) that consumed 4 × 50 mL doses of deuterium oxide (2H2O) per day for 14 days. ABD is measured by label‐free quantitation and FSR is calculated from time‐dependent changes in peptide mass isotopomer abundances. One‐hundred one proteins have at least one unique peptide and are used in the assessment of protein ABD. Fifty‐four of these proteins meet more stringent criteria and are used in the assessment of FSR data. The median (M), lower‐, (Q1) and upper‐quartile (Q3) values for protein FSR (%/d) are M = 1.63, Q1 = 1.07, and Q3 = 3.24, respectively. The technical CV of ABD data has a median value of 3.6% (Q1 1.7% to Q3 6.7%), whereas the median CV of FSR data is 10.1% (Q1 3.5% to Q3 16.5%). These values compare favorably against other assessments of technical repeatability of proteomics data, which often set a CV of 20% as the upper bound of acceptability. 相似文献
53.
Nigel E. Hussey Sabine P. Wintner Sheldon F. J. Dudley Geremy Cliff David T. Cocks M. Aaron MacNeil 《The Journal of animal ecology》2010,79(1):184-193
1. Life-history theory predicts that organisms will provide an optimal level of parental investment for offspring survival balanced against the effects on their own survival and future reproductive potential.
2. Optimal resource allocation models also predict an increase in reproductive output with age as expected future reproductive effort decreases. To date, maternal investment in sharks has received limited attention.
3. We found that neonatal dusky sharks ( Carcharhinus obscurus ) are not independent from maternal resource allocation at the point of parturition but instead are provisioned with energy reserves in the form of an enlarged liver that constitutes approximately 20% of total body mass.
4. Analysis of long-term archived data sets showed that a large proportion of this enlarged liver is utilized during the first weeks or months of life suggesting that the reported weight loss of newborn sharks signifies a natural orientation process and is not necessarily related to prey abundance and/or indicative of high mortality rates.
5. Interrogation of near-term pup mass in two carcharhinids, the dusky and spinner shark ( Carcharhinus brevipinna ), further revealed an increase in reproductive output with maternal size, with evidence for a moderate decline in the largest mothers.
6. For the dusky shark, there was a trade-off between increasing litter size and near-term pup mass in support of optimal offspring size theory.
7. For both the dusky and spinner shark, there was a linear increase in near-term pup mass with month, which may indicate variable parturition strategies and/or that carcharhinids are able to adjust the length of the gestation period.
8. The identification of optimal size-specific reproductive output has direct implications for improving the reproductive potential of exploited shark populations and for structuring future management strategies. 相似文献
2. Optimal resource allocation models also predict an increase in reproductive output with age as expected future reproductive effort decreases. To date, maternal investment in sharks has received limited attention.
3. We found that neonatal dusky sharks ( Carcharhinus obscurus ) are not independent from maternal resource allocation at the point of parturition but instead are provisioned with energy reserves in the form of an enlarged liver that constitutes approximately 20% of total body mass.
4. Analysis of long-term archived data sets showed that a large proportion of this enlarged liver is utilized during the first weeks or months of life suggesting that the reported weight loss of newborn sharks signifies a natural orientation process and is not necessarily related to prey abundance and/or indicative of high mortality rates.
5. Interrogation of near-term pup mass in two carcharhinids, the dusky and spinner shark ( Carcharhinus brevipinna ), further revealed an increase in reproductive output with maternal size, with evidence for a moderate decline in the largest mothers.
6. For the dusky shark, there was a trade-off between increasing litter size and near-term pup mass in support of optimal offspring size theory.
7. For both the dusky and spinner shark, there was a linear increase in near-term pup mass with month, which may indicate variable parturition strategies and/or that carcharhinids are able to adjust the length of the gestation period.
8. The identification of optimal size-specific reproductive output has direct implications for improving the reproductive potential of exploited shark populations and for structuring future management strategies. 相似文献
54.
Background
Cyclic nucleotides are ubiquitous intracellular messengers. Until recently, the roles of cyclic nucleotides in plant cells have proven difficult to uncover. With an understanding of the protein domains which can bind cyclic nucleotides (CNB and GAF domains) we scanned the completed genomes of the higher plants Arabidopsis thaliana (mustard weed) and Oryza sativa (rice) for the effectors of these signalling molecules. 相似文献55.
Rainer TH Jacobs P Ng YC Cheung NK Tam M Lam PK Wong R Cocks RA 《BMJ (Clinical research ed.)》2000,321(7271):1247-1251
ObjectivesTo investigate the cost effectiveness of intravenous ketorolac compared with intravenous morphine in relieving pain after blunt limb injury in an accident and emergency department.DesignDouble blind, randomised, controlled study and cost consequences analysis.SettingEmergency department of a university hospital in the New Territories of Hong Kong.Participants148 adult patients with painful isolated limb injuries (limb injuries without other injuries).ResultsNo difference was found in the median time taken to achieve pain relief at rest between the group receiving ketorolac and the group receiving morphine, but with movement the median reduction in pain score in the ketorolac group was 1.09 per hour (95% confidence interval 1.05 to 2.02) compared with 0.87 (0.84 to 1.06) in the morphine group (P=0.003). The odds of experiencing adverse events was 144.2 (41.5 to 501.6) times more likely with morphine than with ketorolac. The median time from the initial delivery of analgesia to the participant leaving the department was 20 (4.0 to 39.0) minutes shorter in the ketorolac group than in the morphine group (P=0.02). The mean cost per person was $HK44 (£4; $5.6) in the ketorolac group and $HK229 in the morphine group (P<0.0001). The median score for patients'' satisfaction was 6.0 for ketorolac and 5.0 for morphine (P<0.0001).ConclusionIntravenous ketorolac is a more cost effective analgesic than intravenous morphine in the management of isolated limb injury in an emergency department in Hong Kong, and its use may be considered as the dominant strategy. 相似文献
56.
The alpha adrenoceptors on endothelial cells 总被引:4,自引:0,他引:4
Endothelial cells release a powerful factor (endothelium-derived relaxing factor [EDRF]) that relaxes smooth muscle cells in response to some vasodilating agents such as acetylcholine. Contraction curves to norepinephrine (NE) in greyhound, mongrel dog, and pig coronary artery rings were studied in vitro in the presence of propranolol. Removal of endothelium increased the sensitivity and maximum contraction in response to NE. In other experiments pig coronary rings were precontracted with a thromboxane mimetic U 46619 in the presence of propranolol. NE relaxed these arteries only if endothelium was present. Methoxamine was without effect but the relaxation response to NE was antagonized by phentolamine, idazoxan, and yohimbine, which suggests that there are alpha 2 adrenoceptors on endothelial cells that mediate the release of EDRF. Greyhound and mongrel dog large coronary arteries relaxed to NE only if prazosin was present, which suggests that alpha 1-adrenoceptor stimulation on the vascular smooth muscle can override the relaxation response to EDRF. Comparison of NE responses in carotid, mesenteric, renal, and femoral large arteries of the pig, greyhound, and mongrel dog indicate the nonuniformity of distribution of alpha 2 adrenoceptors on endothelium and alpha 1 and alpha 2 adrenoceptors on vascular smooth muscle. The integrity of the endothelium must now be considered in interpreting the vascular responses to alpha-adrenoceptor agonists. 相似文献
57.
Toby J. Ellmers Adam J. Cocks Michail Doumas A. Mark Williams William R. Young 《PloS one》2016,11(11)
We examined the effect of increased cognitive load on visual search behavior and measures of gait performance during locomotion. Also, we investigated how personality traits, specifically the propensity to consciously control or monitor movements (trait movement ‘reinvestment’), impacted the ability to maintain effective gaze under conditions of cognitive load. Healthy young adults traversed a novel adaptive walking path while performing a secondary serial subtraction task. Performance was assessed using correct responses to the cognitive task, gaze behavior, stepping accuracy, and time to complete the walking task. When walking while simultaneously carrying out the secondary serial subtraction task, participants visually fixated on task-irrelevant areas ‘outside’ the walking path more often and for longer durations of time, and fixated on task-relevant areas ‘inside’ the walkway for shorter durations. These changes were most pronounced in high-trait-reinvesters. We speculate that reinvestment-related processes placed an additional cognitive demand upon working memory. These increased task-irrelevant ‘outside’ fixations were accompanied by slower completion rates on the walking task and greater gross stepping errors. Findings suggest that attention is important for the maintenance of effective gaze behaviors, supporting previous claims that the maladaptive changes in visual search observed in high-risk older adults may be a consequence of inefficiencies in attentional processing. Identifying the underlying attentional processes that disrupt effective gaze behaviour during locomotion is an essential step in the development of rehabilitation, with this information allowing for the emergence of interventions that reduce the risk of falling. 相似文献
58.
Determining the evolutionary potential of a gene 总被引:4,自引:0,他引:4
In addition to information for current functions, the sequence of a gene
includes potential information for the evolution of new functions. The
wild-type ebgA (evolved beta-galactosidase) gene of Escherichia coli
encodes a virtually inactive beta-galactosidase, but that gene has the
potential to evolve sufficient activity to replace the lacZ gene for growth
on the beta-galactoside sugars lactose and lactulose. Experimental
evidence, which has suggested that the evolutionary potential of Ebg enzyme
is limited o two specific amino acid replacements, is limited to examining
the consequences of single base- substitutions. Thirteen
beta-galactosidases homologous with the Ebg beta-galactosidase are widely
dispersed, being found in gram-negative and gram-positive eubacteria and in
a eukaryote. A comparison of Ebg beta-galactosidase with those 13
beta-galactosidases shows that Ebg is part of an ancient clade that
diverged from the paralogous lacZ beta- galactosidase over 2 billion years
ago. Ebg differs from other members of its clade at only 2 of the 15
active-site residues, and the two mutations required for full Ebg
beta-galactosidase activity bring Ebg into conformity with the other
members of its clade. We conclude that either these are the only acceptable
amino acids at those positions, or all of the single-base-substitution
replacements that must arise as intermediates on the way to other
acceptable amino acids are so deleterious that they constitute a deep
selective valley that has not been traversed in over 2 billion years. The
evolutionary potential of Ebg is thus limited to those two replacements.
相似文献
59.
EFFECT OF THYROID HORMONE ON THE BIOCHEMICAL MATURATION OF RAT BRAIN: CONVERSION OF GLUCOSE-CARBON INTO AMINO ACIDS 总被引:8,自引:2,他引:6
- 1 The rapid and extensive conversion of glucose-carbon into amino acids is an index of the final coordination of the mechanisms underlying energy metabolism in the adult brain. This phenomenon develops in the rat during a short period extending from 10 to about 19 days after birth. The underlying factors have been analysed.
- 2 The development of the pattern of distribution of glucose-carbon characteristic of the adult brain was markedly influenced by the thyroid state of the animals. The age-curve for the conversion of glucose-carbon into brain amino acids was displaced to the left after treatment with thyroid hormone (T3) in infancy thus indicating an accelerated maturation. Conversely, neonatal thyroidectomy resulted in a significant retardation in the conversion of glucose-carbon into amino acids.
- 3 The specific radioactivity of glutamate increased five-fold in the brain of normal rats from the 10th to the 19th day of age. The values (as a percentage of those for littermate controls) were 220 in the case of the 10 day-old thyroid treated rats and about 30 for the 19 day-old thyroid deficient animals. At the age of 10 days neither treatment affected the concentration of glutamate which was also only slightly less than the control values in the brain of 19 day-old thyroid deficient animals (–17 per cent).
- 4 Specific pool(s) of glutamate associated with the formation of GABA can be demonstrated in the brain of 19 day-old rats after administration of [U-14C]glucose as a result of anoxia post mortem. These pools did not develop in the brain of 10 day-old animals. Neonatal thyroidectomy retarded the development of these glutamate pools.
- 5 Evidence is summarized which indicates that the development of the rapid conversion of glucose-carbon into amino acids reflects the enlargement, during maturation, of the metabolic compartments which are associated with neuronal processes.
60.
An immunological approach has been used for the study of alkaline phosphatase evolution in bacteria of the family Enterobacteriaceae. Antisera were prepared against alkaline phosphatase from Escherichia coli and Klebsiella aerogenes and tested against the unpurified alkaline phosphatases of 32 strains of enterobacteria by double diffusion and quantitative micro-complement fixation. The immunological relationships detected among the alkaline phosphatases of enterobacteria agree approximately with those reported for five other enzymes, as well as with the tryptic peptide pattern similarities found for two other enzymes, and with the relationships detected by interspecific deoxyribonucleic acid hybridization tests. 相似文献