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This study was designed to test the reproducibility of a food frequency questionnaire used in a population‐based case‐control study on diet and pancreatic cancer. Repeat questionnaires covering the same time period were obtained using 63 male and female population controls, 35–79 years of age. For selected food items included in the case‐control study, the attenuation of the odds ratios due to random error was estimated. Using 54 male and female population controls, 35–79 years of age, we conducted a second study to examine the agreement between original and repeat interviews when the time interval between interview and the period of interest was constant.

In the first study, the median correlation coefficient was 0.72 for foods (ranging from 0.36 and 0.59 for subgroups of vegetables to 0.96 for alcoholic beverages) and 0.77 for nutrients (ranging from 0.62 for β‐carotene to 0.85 for energy and 0.91 for ethanol). In the second study, the median correlation coefficient was 0.68 for foods (ranging from 0.28 for eggs to 0.87 for alcoholic beverages) and 0.75 for nutrients (ranging from 0.48 for β‐carotene to 0.76 for energy).

We conclude that for most items the agreement between original and repeat estimates was moderate (r> 0.50) to high (r > 0.70). Moderate agreement was found for 28 of 33 food items (85%) and for all 21 nutrient items (100%) and high agreement for 19 of 33 of food items (56%) and 15 of 21 nutrient items (71 %). In the second study, agreement was somewhat lower but closely paralleled the results of the first study. On average, random error presumably attenuated most of the observed diet‐cancer relationships only moderately; i.e., an observed odds ratio of 1.5 and a correlation coefficient of 0. 70 yield an unattenuated odds ratio of 2.1.  相似文献   
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The purpose of the study was to investigate the sequence of processes occurring during and after hypoxia-induced acidemia. We used proton nuclear magnetic resonance spectroscopy, which provides an overview of metabolites in cerebrospinal fluid (CSF), reflecting neuronal metabolism and damage. The pathophysiological condition of acute fetal asphyxia was mimicked by reducing maternal uterine blood flow in 14 unanesthetized pregnant ewes. CSF metabolites were measured during hypoxia-induced acidemia, and during the following recovery period, including the periods at 24 and 48 h after the hypoxic insult. Maximum values of the following CSF metabolites were reached during severe hypoxia (pH 相似文献   
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Although reproductive factors have been shown to be related to the composition of bile and functioning of the biliary system, their relationship with biliary tract cancer has not been studied in detail. Between 1984 and 1987 we conducted a case-control study of 75 women with cancer of the biliary tract and 252 controls from the general population. An interviewer-administered questionnaire was used to collect information on reproductive history. The information was obtained from the responders themselves (direct response) or from relatives (indirect response). Our results indicate that younger age at menarche, early age at first pregnancy, higher number of pregnancies and prolonged fertility may enhance the risk of cancer of the biliary tract. Overall, increased exposure to endogenous oestrogens and progesterone constitutes a higher risk. © 1994 Wiley-Liss, Inc.  相似文献   
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This study was designed to test the reproducibility of a food frequency questionnaire used in a population-based case-control study on diet and pancreatic cancer. Repeat questionnaires covering the same time period were obtained using 63 male and female population controls, 35-79 years of age. For selected food items included in the case-control study, the attenuation of the odds ratios due to random error was estimated. Using 54 male and female population controls, 35-79 years of age, we conducted a second study to examine the agreement between original and repeat interviews when the time interval between interview and the period of interest was constant. In the first study, the median correlation coefficient was 0.72 for foods (ranging from 0.36 and 0.59 for subgroups of vegetables to 0.96 for alcoholic beverages) and 0.77 for nutrients (ranging from 0.62 for beta-carotene to 0.85 for energy and 0.91 for ethanol). In the second study, the median correlation coefficient was 0.68 for foods (ranging from 0.28 for eggs to 0.87 for alcoholic beverages) and 0.75 for nutrients (ranging from 0.48 for beta-carotene to 0.76 for energy). We conclude that for most items the agreement between original and repeat estimates was moderate (r > 0.50) to high (r > 0.70). Moderate agreement was found for 28 of 33 food items (85%) and for all 21 nutrient items (100%) and high agreement for 19 of 33 of food items (56%) and 15 of 21 nutrient items (71%). In the second study, agreement was somewhat lower but closely paralleled the results of the first study. On average, random error presumably attenuated most of the observed diet-cancer relationships only moderately; i.e., an observed odds ratio of 1.5 and a correlation coefficient of 0.70 yield an unattenuated odds ratio of 2.1.  相似文献   
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Background  

Condensation on the scope’s lens resulting from differences between room temperature and intraabdominal temperature is a disturbing problem for laparoscopic surgeons. Anti lens condensation solutions prevent fogging in the intraabdominal environment but are troublesome to apply to the scope.  相似文献   
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In terminally-ill patients in the Netherlands deep sedation by means of a continuous subcutaneous infusion with midazolam occurs more frequently than euthanasia and assisted suicide. Deep terminal sedation is applied to relieve symptoms during the phase of dying, but in contrast to euthanasia and assisted suicide, does not hasten death. In three terminally-ill patients, a 65-year-old man suffering from pulmonary carcinoma, a 94-year-old woman with general malaise, nausea and anorexia, and a 79-year-old woman in the final stage of ovarian carcinoma, a general-practitioner advisor was consulted about an end-of-life decision--deep terminal sedation versus euthanasia or assisted suicide. The first two patients were given deep sedation until death, in both cases a day and a half later. The third patient's request for euthanasia was considered to meet the legal criteria for euthanasia. Compliance with the Dutch statutory criteria for due care in euthanasia and assisted suicide might also be helpful when deciding about terminal deep sedation, but the role and responsibility of the attending physician may differ. However, the radical effects of sedation on the terminally-ill patient and the rapid changes in the clinical situation of the patient when the decision to sedate is taken, both emphasize the need for consultation with another physician.  相似文献   
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