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排序方式: 共有280条查询结果,搜索用时 15 毫秒
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Jennifer C. Chen Katrina L. Schmid Brian Brown Marion H. Edwards Bibianna SY Yu John KF Lew 《Clinical & experimental optometry》2003,86(5):323-330
Purpose: Caucasian children with myopia have elevated response accommodative vergence to accommodation (AC/A) ratios. The purpose of this study was twofold: to determine if response AC/A ratios vary with refractive error and with myopic progression rate in Hong Kong Chinese children, and to determine the effect of beta‐adrenergic antagonism with topical timolol application on AC/A ratios. Methods: Thirty children aged eight to 12 years participated in the study. All refractive errors were corrected with spectacle lenses. Accommodative responses were measured using a Shin‐Nippon autorefractor and concurrent changes in vergence were assessed using a vertical prism and a Howell‐Dwyer card at three metres and 0.33 metre. Accommodative demand was altered using plus or minus two dioptre lenses and lens‐ and distance‐induced response AC/A ratios were calculated. Measurements were repeated 30 minutes after the instillation of topical timolol maleate (0.5 per cent). Results: AC/A ratios appeared higher in progressing myopic children but the difference was not statistically significant. Timolol application reduced accommodative convergence (AC) in the stable myopes (reduction = ‐3 ± 1.14A) but not in the emmetropes (0.69 ± 0.9P) or progressing myopes (0.16 ± 0.43A) and this difference between refractive groups was statistically s ignificant (F2,27= 3.766; P= 0.036). However, timolol did not produce a significant change in the accommodative response to positive or negative lenses or response AC/A ratios. Conclusions: We did not find that AC/A ratios in myopic Chinese children were elevated and therefore, it is unlikely that elevated AC/A ratios are responsible for the high levels of myopia that occur in Hong Kong. The finding that timolol reduced AC in the stable myopes suggests that the autonomic control of accommodative convergence in these children may be different from that in emmetropic children and those with progressing myopia. 相似文献
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Leukotriene B4 (LTB4) and the protein kinase C activator, 4-beta-phorbol dibutyrate (PDBu), both induced a pronounced and concentration-dependent stimulation of hydrogen peroxide (H2O2) generation by purified guinea pig peritoneal eosinophils in the concentration range 1 nM-1 microM. The LTB4 response was inhibited competitively by the specific LTB4 receptor antagonist, U-75302, with a KB of 25 nM, while the concentration-response curves for both stimuli were shifted rightwards (3.8-fold and 2.8-fold for LTB4 and PDBu, respectively) by the competitive protein kinase C inhibitor, 1-O-hexadecyl-2-O-methylglycerol at a concentration of 300 microM. LTB4 appears, therefore, to induce respiratory burst in eosinophils via a receptor-mediated mechanism involving protein kinase C. 相似文献
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D. Pieber F. Zivkovic K. Tamussino G. Ralph G. Lippitt B. Fauland 《International urogynecology journal》1995,6(1):14-17
The authors compared intensive pelvic floor exercise alone (A) with intensive pelvic floor exercise plus vaginal cones (B) in premenopausal women with mild to moderate stress urinary incontinence. Forty-six patients (mean 43±6 years) were randomized into two training groups and treated for 3 months. Pre- and post-therapy urethral pressure profiles at rest and under stress and subjective results were obtained from 29 patients. The subjective improvement rate of the compliant patients after 12 weeks was 85% in group A and 84% in group B. When the dropouts (9 in group A and 8 in group B) were included in the subjective results an overall improvement rate of 48% in group A and 52% in group B was obtained. In group A one pressure transmission ratio (PTR) improved significantly at 6 weeks and the position of maximum urethral closure pressure was shifted proximally at 12 weeks. In group B one PTR in the midurethra was improved significantly at 6 weeks. The other urodynamic parameters were unchanged. There were no differences between groups A and B in subjective results or urodynamic findings. These results suggest that intensive pelvic floor exercise with or without vaginal cones improves the symptoms of mild to moderate stress incontinence in about 85% of premenopausal women, but that it has little effect on urodynamic parameters. Vaginal cones provided no additional benefit but may be useful for women for whom closely supervised pelvic floor exercise is not available.Editorial Comment: It is becoming increasingly clear from the literature that pelvic floor muscle exercises are effective in improving continence in many women with straightforward stress incontinence. An appropriate quest continues to determine how the exercises can best be taught and done. This article demonstrates that with frequent supervision, similar continence status is achieved both with and without the use of vaginal cones. It would be interesting to compare outcomes with and without cones in women who saw a health care provider only once for their initial teaching. If cones were found to be more effective in this setting, that would be a great aid to primary care physicians.The authors state that there was no correlation between the cone weight and the degree of improvement of symptoms: however, only 2 of the subjects progressed to the next heaviest cone weight. My understanding of the principles of athletic muscles training is that as one increases the resistance the muscle fibers hypertrophy and strengthen. This is the principle behind building biceps. Body-builders or power-lifters continue to increase the amount of weight (resistance) they lift in order to increase bulk and strength. I wonder if this same principle is the reason for the differences in results between this study and the one by Peattie et al. quoted by the authors. My major concern is that people begin to devalue the amount of effort required to perform effective pelvic floor exercises and make assumptions that such exercises are not as good as a permanent surgical cure. I believe that we have not yet begun to develop really effective muscle strengthening regimens for the pelvic floor, and attitudes such as the above will only serve to inhibit our progress. 相似文献
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Human high molecular weight kininogen (HMWK), a single-chain protein with mol wt 120,000, is cleaved by human urinary kallikrein (HUK) to release kinin from within a disulfide loop and form a two-chain protein that retains all the procoagulant activity of the native molecule. Cleavage of HMWK by HUK is associated with a reduction in size to mol wt 115,000, as assessed by SDS-PAGE of unreduced protein, whereas the two chains of the reduced protein present together as a single broad band with mol wt 64,000. The 64,000 chain with procoagulant activity was chromatographically separated from the nonfunctional chain of similar size. The homogeneous procoagulant chain had an amino acid composition similar to that of smaller procoagulant ("light") chains isolated by others upon cleavage of HMWK with plasma kallikrein and elicited an antiserum that was monospecific by Ouchterlony analysis and inhibited the procoagulant function of HMWK. Thus, the limited proteolysis of HMWK by HUK has permitted, for the first time, the isolation of a stable procoagulant chain that is equal in size to the nonfunctional chain. The common terminology of "heavy" and "light" chain for kinin-free kininogen obtained with plasma kallikrein reflects the continued degradation of the procoagulant carboxyterminal chain and is not appropriate for the initial two-chain product formed when kinin is released from HMWK. It is proposed that the initial cleavage products of HMWK be designated the A-chain, the B-fragment, and the C- chain, representing the amino-terminal chain, the released vasoactive peptide containing the bradykinin sequence, and the carboxy-terminal procoagulant chain, respectively. Thus, intact HMWK would contain, in sequence, A, B, and C regions. 相似文献
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The focus on quality of life issues in wound care has justly taken a far greater importance. With the acceptance that pain can be a major factor to the patient, and in particular, pain at dressing change comes the opportunity for avoidance and/or reduction strategies. Whilst pain has been associated with wound infection for millennia, it is only much more recently that this has received due attention from research and clinical practice. In this study, the nature of pain, changes in pain and pain associated with infection are the focal points. A Delphi approach, now a frequently used tool in wound care research, has been used to obtain expert opinion on these aspects of management. 相似文献
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