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排序方式: 共有1997条查询结果,搜索用时 31 毫秒
911.
912.
MB Katan JP Deslypere AP van Birgelen M Penders M Zegwaard 《Canadian Metallurgical Quarterly》1997,38(10):2012-2022
Tissue levels of n-3 fatty acids reflect dietary intake, but quantitative data about rate of incorporation and levels as a function of intake are scarce. We fed 58 men 0, 3, 6, or 9 g/d of fish oil for 12 months and monitored fatty acids in serum cholesteryl esters, erythrocytes, and subcutaneous fat during and after supplementation. Eicosapentaenoic acid (EPA) in cholesteryl esters plateaued after 4-8 weeks; the incorporation half-life was 4.8 days. Steady-state levels increased by 3.9 +/- 0.3 mass % points (+/- SE) for each extra gram of EPA eaten per day. Incorporation of docosahexaenoic acid (DHA) was erratic; plateau values were 1.1 +/- 0.1 mass % higher for every g/d ingested. Incorporation of EPA into erythrocyte membranes showed a half-life of 28 days; a steady state was reached after 180 days. Each g/d increased levels by 2.1 +/- 0.1 mass %. C22:5n-3 levels increased markedly. Changes in DHA were erratic and smaller. EPA levels in adipose tissue rose also; the change after 6 months was 67% of that after 12 months in gluteal and 75% in abdominal fat. After 12 months each gram per day caused an 0.11 +/- 0.01 mass % rise in gluteal fat for EPA, 0.53 +/- 0.07 for C22:5n-3, and 0.14 +/- 0.03 for DHA. Thus, different (n-3) fatty acids were incorporated with different efficiencies, possibly because of interconversions or different affinities of the enzymatic pathways involved. EPA levels in cholesteryl esters reflect intake over the past week or two, erythrocytes over the past month or two, and adipose tissue over a period of years. These findings may help in assessing the intake of (n-3) fatty acids in epidemiological studies. 相似文献
913.
AP Weston PT Krmpotich R Cherian A Dixon M Topalosvki 《Canadian Metallurgical Quarterly》1997,92(3):407-413
OBJECTIVES: Barrett's esophagus is associated with adenocarcinoma of the cardia and esophagus, regardless of its extent. The aim of this study was to compare the prevalence and incidence of dysplasia and adenocarcinoma in short segment and traditional long segment Barrett's esophagus. METHODS: Seventy-four patients with short segment Barrett's and 78 with traditional Barrett's entered the study. RESULTS: There were no significant differences in age or gender between the two groups of patients with Barrett's esophagus. A greater percentage of patients with short segment barrett's were black (p = 0.04). The prevalence of dysplasia at diagnosis in patients with short segment Barrett's was 8.1% versus 24.4% in patients with traditional Barrett's (p < 0.007). Adenocarcinoma was noted at diagnosis only in patients with traditional Barrett's (p < 0.0005). Twenty-six patients with short segment Barrett's and 29 with traditional Barrett's were followed prospectively for 12-40 months. Dysplasia developed during follow-up in two patients with short segment Barrett's and in six patients with traditional Barrett's (p < 0.05). Neither high grade dysplasia nor cancer developed in any patients with short segment Barrett's. High grade dysplasia did develop in two patients with traditional Barrett's esophagus, and mucosal adenocarcinoma developed in one. The frequency of dysplasia on the latest surveillance examination continued to be significantly higher for patients with traditional Barrett's (p = 0.03). Follow-up surveillance biopsy specimens of Barrett's mucosa frequently demonstrated an absence of goblet cells in patients with short segment Barrett's compared with patients with traditional Barrett's (p < 0.0001). CONCLUSIONS: The prevalence of dysplasia or adenocarcinoma and the incidence of dysplasia in patients with traditional Barrett's esophagus are significantly higher than in patients with short segment Barrett's esophagus. Further prospective surveillance is required to determine whether the incidence of adenocarcinoma in patients with short segment Barrett's esophagus is significantly lower. 相似文献
914.
915.
The aim of this study was to determine whether the prevention of stroke with perindopril treatment in stroke-prone spontaneously hypertensive rats (SHRSP) is associated with the preservation of the myogenic properties of the cerebral arteries. After weaning at 4 weeks of age, male SHRSP were fed a Japanese-style rat diet with high salt to induce stroke development. Treatment with perindopril was given by gavage every morning beginning at 6 weeks of age. There were three experimental groups: two groups treated with 4 mg.kg-1.day-1 perindopril for different durations (8 or 12 weeks) and one control group consisting of littermates given distilled water. All the control animals developed stroke and died within 14 weeks of age, and myogenic response of the middle cerebral arteries (MCA) to pressure increase was lost in these animals. In contrast, all the treated SHRSP survived during the treatment period, and myogenic response of the MCA was preserved. After withdrawal of the treatment, SHRSP treated for a longer period (12 weeks) also survived longer than those treated for a shorter period (8 weeks). The subsequent development of stroke and death following treatment withdrawal after 8 or 12 weeks of treatment was associated with the loss of pressure-dependent constriction in MCA. A longer treatment duration also increased the stiffness of the MCA, MCA from SHRSP after 12 weeks of treatment had smaller external and lumen diameters, and thicker walls than those from the 8-week treatment group. In a separate study, we found that treatment of SHRSP with 1 or 4 mg.kg-1.day-1 of perindopril for 24 weeks beginning at 6 weeks of age also protected them against death related to stroke, because these rats survived up to 43 weeks of age, when the experiment was terminated. We conclude that there is an association between the absence of myogenic response in cerebral arteries and stroke development in SHRSP. Perindopril treatment preserves the myogenic response of MCA in SHRSP and prevents the stroke development in these animals. A prolonged treatment could increase the survival of SHRSP through a remodelling of the MCA and increasing the stiffness of the cerebral arteries. 相似文献
916.
AP Prodeus S Goerg LM Shen OO Pozdnyakova L Chu EM Alicot CC Goodnow MC Carroll 《Canadian Metallurgical Quarterly》1998,9(5):721-731
The role of complement in the maintenance of self-tolerance has been examined in two models: an immunoglobulin transgenic model of peripheral tolerance and a lupus-like murine model of CD95 (Fas) deficiency. We find that self-reactive B lymphocytes deficient in complement receptors CD21/CD35 or transferred into mice deficient in the complement protein C4 are not anergized by soluble self-antigen. In the second model, deficiency in CD21/CD35 or C4 combined with CD95 deficiency results in high titers of anti-nuclear antibodies leading to severe lupus-like disease. These findings suggest a novel role for the complement system in B cell tolerance and provide insight into the genetic association of complement deficiency with susceptibility to systemic lupus erythematosus. 相似文献
917.
AP Houdijk ER Rijnsburger J Jansen RI Wesdorp JK Weiss MA McCamish T Teerlink SG Meuwissen HJ Haarman LG Thijs PA van Leeuwen 《Canadian Metallurgical Quarterly》1998,352(9130):772-776
BACKGROUND: Infections are an important cause of morbidity and mortality in patients with multiple trauma. Studies in both animals and human beings have suggested that glutamine-enriched nutrition decreases the number of infections. METHODS: Patients with multiple trauma with an expected survival of more than 48 h, and who had an Injury Severity Score of 20 or more, were randomly allocated glutamine supplemented enteral nutrition or a balanced, isonitrogenous, isocaloric enteral-feeding regimen along with usual care. Each patient was assessed every 8 h for infection, the primary endpoint. Data were analysed both per protocol, which included enteral feeding for at least 5 days, and by intention to treat. FINDINGS: 72 patients were enrolled and 60 received enteral feeding (29 glutamine-supplemented) for at least 5 days. Five (17%) of 29 patients in the glutamine-supplemented group had pneumonia compared with 14 (45%) of 31 patients in the control group (p<0.02). Bacteraemia occurred in two (7%) patients in glutamine group and 13 (42%) in the control group (p<0.005). One patient in the glutamine group had sepsis compared with eight (26%) patients in the control group (p<0.02). INTERPRETATION: There was a low frequency of pneumonia, sepsis, and bacteraemia in patients with multiple trauma who received glutamine-supplemented enteral nutrition. Larger studies are needed to investigate whether glutamine-supplemented enteral nutrition reduces mortality. 相似文献
918.
AP Goldman RC Tasker S Hosiasson T Henrichsen DJ Macrae 《Canadian Metallurgical Quarterly》1997,112(3):752-758
OBJECTIVE: To examine whether the early response to inhaled nitric oxide (iNO) is a measure of reversibility of lung injury and patient outcome in children with acute hypoxemic respiratory failure (AHRF). DESIGN: Retrospective review study. SETTING: Pediatric ICUs. PATIENTS: Thirty infants and children, aged 1 month to 13 years (median, 7 months) with severe AHRF (mean alveolar arterial oxygen gradient of 568+/-9.3 mm Hg, PaO2/fraction of inspired oxygen of 56+/-2.3, oxygenation index [OI] of 41+/-3.8, and acute lung injury score of 2.8+/-0.1). Eighteen patients had ARDS. INTERVENTIONS: The magnitude of the early response to iNO was quantified as the percentage change in OI occurring within 60 min of initiating 20 ppm iNO therapy. This response was compared to patient outcome data. MEASUREMENTS AND RESULTS: There was a significant association between early response to iNO and patient outcome (Kendall tau B r=0.43, p < 0.02). All six patients who showed < 15% improvement in OI died; 4 of the 11 patients (36%) who had a 15 to 30% improvement in OI survived, while 8 of 13 (61%) who had a > 30% improvement in OI survived. Overall, 12 patients (40%) survived, 9 with ongoing conventional treatment including iNO, and 3 with extracorporeal support. CONCLUSIONS: In AHRF in children, greater early response to iNO appears to be associated with improved outcome. This may reflect reversibility of pulmonary pathophysiologic condition and serve as a bedside marker of disease stage. 相似文献
919.
AS Van Der Burght AP Kreikamp GJ Horbach W Seinen M Van Den Berg 《Canadian Metallurgical Quarterly》1998,72(10):630-636
We have developed a mathematical algorithm to compare and distinguish matrix-assisted laser desorption/ionization (MALDI) mass spectra of whole bacteria cells. This fingerprint matching technique eliminates the subjectivity involved in visually comparing two spectra to determine whether they match and it provides a quantitative measure of spectral similarity. Using it, we have distinguished twenty five different strains of a single bacteria species, E. coli. Cells are grown in culture, samples are prepared, and MALDI-TOF mass spectra are recorded for each strain. Pairs of spectra are compared by a modified cross-correlation procedure. This modified approach increases the sensitivity of correlation analysis to small spectral differences. The technique can be fine-tuned by varying the number of intervals into which spectra are divided. 相似文献
920.
An observational study of 144 (mean age 50 [range 45-57] years) perimenopausal women randomly selected from the National Register was conducted in order, to study long term effects of vaginal deliveries on anorectal function. The mean number of vaginal deliveries was two (range 0-6). Measurements were perineal position at rest and during straining, anal mucosa electrosensitivity, maximum resting pressure, maximum squeeze pressure of the anal sphincters, and pudendal nerve terminal motor latency. All tests were performed by a single investigator (AMR) who had no knowledge of the subject's parity. Increasing parity correlated with a lowered perineal position at rest (correlation coefficient (r) = 0.26, p = 0.003) and during straining (r = 0.24, p = 0.006), an increased threshold of anal sensibility (r = 0.22, p = 0.008), and an increased pudendal nerve terminal motor latency (r = 0.27, p = 0.002). No effect of parity on the maximum resting pressure (r = 0.06, p = 0.70) and maximum squeeze pressure (r = 0.06, p = 0.36) was found. The number of vaginal deliveries only accounted for a minor fraction of the total variability (between 3.6-5.7%). It is concluded that repeated vaginal deliveries have a long term adverse effect on anorectal function in a population of randomly selected healthy perimenopausal women. 相似文献