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41.
42.
The effectiveness of beta-carotene (betaC) as a vitamin A (VA) precursor may be influenced by the proportions of cis isomers of betaC consumed in the diet. Although the metabolic fates of cis isomers of betaC are poorly understood, their retinol equivalency has been assigned a value 50% that of all-trans (at) betaC. A dose-response design was used to estimate the relative VA value (VAV) of atbetaC, 9-cis (9c) betaC and 13-cis (13c) betaC in gerbils using total liver retinol as a measure of VAV. Ten groups of gerbils received a daily dose of oil with or without betaC isomer by gavage for 7 d. Nine groups (n = 5) were divided equally among the three betaC dosing treatments with each isomer provided at 141, 275 and 418 nmol/d. Total liver VA (171-259 nmol) in gerbils administered atbetaC was higher than total liver betaC (25-53 nmol). Stores of VA and betaC in livers from gerbils administered atbetaC were higher than stores of VA and betaC in livers from those given 9cbetaC or 13cbetaC. The relative VAV of cis betaC isomers was estimated by comparing slopes of dose-response lines of all three betaC isomers using atbetaC as a reference. Total liver VA and betaC increased linearly (P < 0.05) with increasing betaC intake in gerbils gavaged with all three betaC isomer oils. The relative VAV of 9cbetaC was less (38%) and 13cbetaC was more (62%) than the assigned value of 50% that of atbetaC. Thus, the proportions of cis isomers of betaC contained in a food could negatively affect the vitamin A value of the diet. 相似文献
43.
Lymphatic mapping and sentinel node identification in patients with cervix cancer undergoing radical hysterectomy and pelvic lymphadenectomy. 总被引:37,自引:0,他引:37
Charles Levenback Robert L Coleman Thomas W Burke W Michael Lin William Erdman Michael Deavers Ebrahim S Delpassand 《Journal of clinical oncology》2002,20(3):688-693
PURPOSE: The purpose of this study was to determine the feasibility of sentinel node identification in patients with invasive cervix cancer undergoing radical hysterectomy and pelvic lymphadenectomy using preoperative and intraoperative lymphatic mapping. PATIENTS AND METHODS: Thirty-nine patients at two institutions were enrolled onto this institutional review board-approved study. All underwent preoperative lymphoscintigraphy and intraoperative lymphatic mapping with blue dye and a handheld gamma probe. Radical hysterectomy was aborted in four patients because metastatic disease was discovered on frozen section analysis of the sentinel node. RESULTS: Preoperative lymphoscintigraphy revealed at least one sentinel node in 33 patients (85%), including 21 (55%) with bilateral sentinel nodes. All 39 patients had at least one sentinel node identified intraoperatively. Eighty percent of sentinel nodes were in three pelvic locations: iliac, obturator, and parametrial (in descending order of frequency). The remaining sentinel nodes were in the common iliac and para-aortic nodal basins. A total of 132 nodes were identified clinically as sentinel nodes; 65 (49%) were both blue and hot, 35 (27%) were blue only, and 32 (24%) were hot only. Eight patients (21%) had metastatic disease. In five of these patients, sentinel nodes were the only positive lymph nodes. One patient had false-negative sentinel nodes. She had four microscopically positive parametrial nodes that were resected in continuity with the uterus. The sensitivity of the sentinel node was 87.5% and the negative predictive value was 97%. CONCLUSION: Preoperative lymphoscintigraphy and intraoperative lymphatic mapping were highly successful at identifying sentinel nodes in patients undergoing radical hysterectomy. 相似文献
44.
van Domburg RT Scmidt Pedersen S van den Brand MJ Erdman RA 《Journal of psychosomatic research》2001,51(3):469-477
OBJECTIVE: To examine the independent prognostic value of the four subscales of the Heart Patients Psychological Questionnaire (HPPQ) on mortality in male and female patients 10 years following percutaneous transluminal coronary angioplasty (PTCA). METHODS: The HPPQ, which measures well-being, feelings of being disabled, despondency, and social inhibition, was administered to 356 patients (23% women) post-PTCA. The patients were followed for a median of 10 years. Clinical and demographic variables were sampled from medical records. RESULTS: During the follow-up period, 104 patients (29%) had died. Women scored significantly worse on all psychological subscales compared with men. Fifty-nine (72%) women and 92 (34%) men had a score indicating at least mild to moderate feelings of being disabled. Men scoring high on feelings of being disabled were at increased risk of mortality compared with men having a low score, adjusted for other cardiac risk factors (chi(2)=7; P=.008). No differences were found between women with low or high scores on feelings of being disabled (relative risk (RR): 1.2; 95% confidence interval (CI): 0.5-3.3). None of the other HPPQ subscales were related to mortality. CONCLUSION: Feelings of being disabled measured at least 1 year after hospital discharge is a significant predictor of mortality in men 10 years post-PTCA, but not in women. This finding adds to the increasing knowledge that psychosocial variables influence morbidity and mortality in cardiac patients. 相似文献
45.
A DNA endonuclease, isolated from the nuclei of normal human and xeroderma
pigmentosum complementation group A (XPA) cells, which recognizes
predominately pyrimidine dimers, was examined for the mechanism by which it
locates sites of damage on UVC-irradiated DNA. In reaction mixtures with
low ionic strengths (i.e. lacking KCl), the normal and XPA endonuclease
locate sites of UV damage on both naked and reconstituted nucleosomal DNA
by different mechanisms. On both of these substrates, the normal
endonuclease acts by a processive mechanism, meaning that it binds
non-specifically to DNA and scans the DNA for sites of damage, whereas the
XPA endonuclease acts by a distributive one, meaning that it randomly
locates sites of damage on DNA. However, while both the normal and XPA
endonucleases can incise UVC irradiated naked DNA, they differ in ability
to incise damaged nucleosomal DNA. The normal endonuclease showed increased
activity on UVC treated nucleosomal DNA compared with naked DNA, whereas
the XPA endonuclease showed decreased activity on the damaged nucleosomal
substrate. Since a processive mechanism of action is sensitive to the ionic
strength of the micro-environment, the KCl concentration of the reaction
was increased. At 70 mM KCI, the normal endonuclease switched to a
distributive mechanism of action and its ability to incise damaged
nucleosomal DNA also decreased. These studies show that there is a
correlation between the ability of these endonucleases to act by a
processive mechanism and their ability to incise damaged nucleosomal DNA;
the normal endonuclease, which acts processively, can incise damaged
nucleosomal DNA, whereas the XPA endonuclease, which acts distributively,
is defective in ability to incise this substrate.
相似文献
46.
47.
NRM Buist AP Prince KL Huntington JM Tuerck DD Waggoner 《Acta paediatrica (Oslo, Norway : 1992)》1994,83(S407):75-77
A new amino acid mixture for incorporation into medical foods for the treatment of hyperphenylalaninemia has been tested in a regular clinic. The mix is designed to be as unobtrusive as possible, consistent with good nutrition. After more than 1 year of trial as a beverage, we have shown that it is safe and well tolerated but that plasma phenylalanine is no better controlled than with some other products. The mix can be incorporated into a large number of different foods without affecting the taste. Occult monitoring of the quantity of medical foods purchased compared with the amounts reported to be consumed in diet histories provides an excellent way to monitor dietary compliance. 相似文献
48.
Magnetic resonance imaging of benign mediastinal masses 总被引:1,自引:0,他引:1
49.
50.