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71.
Several reports have described decreased oxygen extraction fractions in tumours relative to those in normal tissues as measured with the oxygen-15 steady state technique and positron emission tomography. The present simulation study was carried out to assess the influence of tissue heterogeneity on these measured values. It was found that, within the range analyzed, tissue heterogeneity always resulted in underestimations of mean values of oxygen extraction fraction. It must, therefore, be concluded that the oxygen-15 steady state technique is not an accurate method for the assessment of the oxygen status of tumours. This finding should also apply to other pathological conditions, where a significant degree of tissue heterogeneity can not be excluded. More generally, this study demonstrates the need for detailed analyses of sensitivities of tracer kinetic procedures to tissue heterogeneity.  相似文献   
72.
73.
Summary: Summary. A study was conducted to determine whether the attitudes of medical students to death and caring changed during the 3 months following exposure to cadaver dissection. All first-year students were invited to complete a questionnaire immediately before their initial cadaver dissection experience, after 6 weeks, and after a further 3 months. The questionnaire reflected attitudes to death, violent death, death of someone known to the respondent and caring when someone known to the respondent is seriously injured. Ethnicity and previous exposure to dying has no effect on responses, but overall men students' reactions were significantly less than for women ( P < 0.001). The responses given on the final part of the questionnaire after 3 months were significantly lower than those to most questions in the first part of the questionnaire. The exceptions were those questions where the subject in the given scenario was known to the respondent, where reactions were rated significantly greater ( P < 0.001) in the follow-up questionnaire and can be explained on the basis that they were a personal referent.
Students rapidly develop a coping mechanism which enables them to view cadaver dissection as an occupation quite divorced from living human beings. During these early months of training solicitude decreases for those who die who are unknown to them, but concern for personal referents increases. Educators should be aware of the dramatic change of attitudes among students and the process of professionalization which might influence their caring of future patients.  相似文献   
74.
Analgesia with preoperative naproxen after laparoscopic sterilization was assessed in a prospective, double-blind, randomized study of 80 women; 42 women received oral naproxen 1 g, approximately 90 min before surgery, and 38 received placebo. Preoperative naproxen did not significantly influence postoperative pain scores, but was associated with a reduction in parenteral opioid administration (P = 0.04).   相似文献   
75.
The role of open lung biopsy (OLB) in the diagnosis of the etiology of lung infiltrates in children was analyzed for a 10-year period 1979-1989 in a tertiary referral center. A total of 18 children had 19 lung biopsies to ascertain the cause of lung infiltrates. Thirteen of these children (72 %) were immunocompromised due to treatment of hematological/solid malignancies and bone marrow transplantation. The clinical diagnosis was bilateral lung infiltrates of unknown etiology in 17 of 18 children. Eight of these children were ventilated for respiratory failure. The biopsy was useful in achieving a histological diagnosis in 18 of 19 samples (diagnostic yield 95%) and an etiological diagnosis in 14 of 19 samples (etiological yield 74 %). Therapeutic strategy was altered in 14 of 18 patients based on the biopsy results. Five of 14 patients responded favorably to a change in specific treatment. The lime interval from onset of respiratory illness to biopsy was 2-60 days (mean 16 days). Despite the critical state of these children there were few complications associated with the biopsy and no mortality directly related to the procedure. We recommend that OLE be undertaken sooner rather than later in immunocompromised children with bilateral pulmonary infiltrates of unknown etiology.  相似文献   
76.
The objective of this study is to compare data about the quantity of alcohol consumed by university undergraduates using a prospective diary with those data collected using a retrospective diary. Five hundred and ninety-eight subjects were randomly selected and divided into two groups matched for age, sex, year of study and subject group; one group received a prospective and one a retrospective questionnaire-301 students received prospective and 297 retrospective questionnaires. Sixty-eight per cent responded to the prospective and 75 per cent to the retrospective survey. There was no significant difference in the median alcohol consumption detected for men or women in this study (p = 0.13; p = 0.47). However, the prospective diary recorded a greater proportion of heavy drinkers, this difference being significant for men and women (p less than 0.05). The quantitative results of the retrospective diary are similar to those obtained by a similar method in a previous survey. The conclusion is that a prospective diary detects a greater proportion of heavy drinkers than a retrospective diary. The prospective survey may be the most appropriate method for assessing alcohol use in certain situations.  相似文献   
77.
78.
Despite being constantly cited as a critical intervening variable in the recovery from alcohol problems, there is a paucity of literature on client motivation. This paper reviews the current literature which impacts on motivation and its importance in treatment and develops in a stepwise manner the revised expectancy/motivation hypothesis, tentatively explaining both motivation and denial as a natural process in behavioural change. Because of the revised expectancy/motivation hypothesis' distinctly defined stages which closely relate to the process of nursing and the qualitative and quantitative measurement it entails which the nursing process demands, it offers a particularly appropriate model for treatment within nurse practice.  相似文献   
79.
Fifty-nine patients with hyperlipoproteinaemia Type IIa and IIb who had failed to respond to 1-month's dietary therapy were treated over a 4-month period with either bezafibrate (600 mg/day) or gemfibrozil (1200 mg/day) in addition to their diet. Fasting serum lipid (cholesterol, HDL-cholesterol and triglycerides) and blood glucose levels were measured on entry and at monthly intervals, and routine laboratory investigations were carried out before and after treatment to monitor hepatic, renal and haematic tolerance. The results showed that whilst both drugs produced significant reductions from baseline in total cholesterol, LDL-cholesterol and triglyceride levels from Day 30 onwards, the reductions were more marked in the bezafibrate group. There was a trend for HDL-cholesterol levels to increase. Fasting blood glucose levels decreased significantly in the bezafibrate group and to a greater extent than in patients on gemfibrozil. Only 1 patient on bezafibrate did not tolerate bezafibrate whereas 13 patients on gemfibrozil reported side-effects, mainly gastro-intestinal, and 4 had to withdraw from the study during the first or second month.  相似文献   
80.
A study was conducted that analyzed the relationship between various characteristics of the preclinical curriculum and institutional performance on the Part I examination of the National Board of Medical Examiners (NBME) at a sample of 85 U.S. medical schools. Total scheduled hours per week was the single curriculum characteristic having a positive and significant relationship with institutional NBME examination performance. However, when the data were controlled by medical school selectivity in admissions and institutional policy on the taking of the examination, total scheduled hours per week failed to make a significant contribution to the prediction of performance. The results were viewed as failing to provide support and justification for intense preclinical curriculum loads on the basis that this would enhance NBME examination performance. The authors conclude that simple comparisons of schools on the basis of mean NBME examination performance are meaningless unless the entering abilities of students and school policies on the examination are taken into account. The authors also suggest that those schools that prescribe heavy and intense preclinical curriculum loads should reexamine those policies in light of recommendations of the Project Panel on the General Professional Education of the Physician and College Preparation for Medicine.  相似文献   
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