Perception of breast cancer: eye-position analysis of mammogram interpretation

RATIONALE AND OBJECTIVE: The author performed this study to determine how image-based elements are translated into decisions by radiologists with different levels of experience in the reading of mammograms. MATERIALS AND METHODS: Three full-time mammographers and four radiology residents read 40 two-view mammogram cases. The observers' eye position was tracked while they searched the mammograms for malignancies. Spatial frequency analysis was performed to relate what the observers reported with where they looked. RESULTS: Statistically significant differences were found between lesion-containing areas that attracted visual attention and were correctly interpreted and those that were visually inspected but not reported. In addition, an artificial neural network was successfully trained to map the image characteristics in the visually selected areas on a mammogram and to linkthem to a likely decision by the observer. CONCLUSION: Spatial frequency analysis can be used to derive trends for how mammographers and radiology residents will respond to mammograms.     

Liquid-Crystal Display Monitors and Cathode-Ray Tube Monitors: A Comparison of Observer Performance in the Detection of Small Solitary Pulmonary Nodules

Objective

To compare observer performance using liquid-crystal display (LCD) and cathode-ray tube (CRT) monitors in the interpretation of soft-copy chest radiographs for the detection of small solitary pulmonary nodules.

Materials and Methods

By reviewing our Medical Center''s radiologic information system, the eight radiologists participating in this study (three board-certified and five resident) retrospectively collected 40 chest radiographs showing a solitary noncalcified pulmonary nodule approximately 1 cm in diameter, and 40 normal chest radiographs. All were obtained using a storage-phosphor system, and CT scans of the same patients served as the gold standard for the presence of a pulmonary nodule. Digital images were displayed on both high-resolution LCD and CRT monitors. The readers were requested to rank each image using a five-point scale (1 = definitely negative, 3 = equivocal or indeterminate, 5 = definitely positive), and the data were interpreted using receiver operating characteristic (ROC) analysis.

Results

The mean area under the ROC curve was 0.8901±0.0259 for the LCD session, and 0.8716±0.0266 for the CRT session (p > 0.05). The reading time for the LCD session was not significantly different from that for the CRT session (37.12 and 41.46 minutes, respectively; p = 0.889).

Conclusion

For detecting small solitary pulmonary nodules, an LCD monitor and a CRT monitor are comparable.     

Chest radiograph interpretation by medical students

AIM: To assess the ability of final year medical students to interpret conventional chest radiographs. MATERIALS AND METHODS: Ten conventional chest radiographs were selected from a teaching hospital radiology department library that were good radiological examples of common conditions. All were conditions that a medical student should be expected to recognize by the end of their training. One normal radiograph was included. The radiographs were shown to 52 final year medical students who were asked to describe their findings. RESULTS: The median score achieved was 12.5 out of 20 (range 6-18). There was no difference between the median scores of male and female students (12.5 and 12.3, respectively, p=0.82) but male students were more likely to be certain of their answers than female students (median certainty scores 23.0 and 14.0, respectively). The overall degree of certainty was low. On no radiograph were more than 25% of students definite about their answer. Students had received little formal radiology teaching (2-42 h, median 21) and few expressed an interest in radiology as a career. Only two (3.8%) students thought they were good at interpreting chest radiographs, 17 (32.7%) thought they were bad or awful. CONCLUSION: Medical students reaching the end of their training do not perform well at interpreting simple chest radiographs. They lack confidence and have received little formal radiological tuition. Perhaps as a result, few are interested in radiology as a career, which is a matter for concern in view of the current shortage of radiologists in the UK.     

鼻咽癌患者5-FU血药浓度与毒性及疗效的关系

背景与目的:5-氟尿嘧啶(5-fluorouracil,5-FU)对人体的作用有几条途径,不同个体对5-FU的代谢有很大的差异,故很难预测5-FU对不同个体的治疗效果和毒副作用。本研究拟探讨5-FU的稳态血药浓度在接受相同初始剂量(按体表面积计算)的患者之间的差异,以及其与不良反应、治疗反应之间的关系。方法:在接受顺铂(cisplatin,DDP)联合5-FU连续静脉灌注治疗的20例鼻咽癌患者中,开始5-FU治疗后24h采集血样,用高效液相色谱仪(HPLC)测定5-FU的血药浓度。HPLC条件:1mmol/L磷酸盐缓冲液作为流动相,流速1.3ml/min,波长260nm,柱温25℃。结果:5-FU血药浓度在鼻咽癌患者中呈正态分布,个体间有明显差异。5-FU血药浓度低于600μg/L时,患者均没有不良反应,而高于1000μg/L时,患者均出现较严重的不良反应。不同级别不良反应及不同的治疗反应所对应的5-FU血药浓度之间存在明显的统计学差异(P<0.05)。结论:5-FU血药浓度在接受相同初始剂量(按体表面积计算)的患者之间存在明显的差异。5-FU血药浓度与其毒副作用、治疗反应有关。     

实行院长负责制的背景、内容及对人员表现的影响

研究院长负责制的实施背景,内容及对人员表现的影响。选择社会经济水平不同的B县（较富裕）和C县（较贫困）两个县进行调查,以召开专题小组讨论（focus group discussion)和知情者访谈（key informant interview)的定性调查方法为主,结合医院收支,诊疗等方面的定量数据进行分析。结果提示院长负责制受到院长,卫技人员的普遍拥护,调动院长与职工的工作积极性。实行院长负责制期间,两个县医院的医疗活动,经济创收,满意度与人员培训方面均有所改善。分析“放权”政策的局限性以及改善人员表现应采取的措施。讨论袄地并完善院长负责制要正确处理扩大自主权和强化束约力的辩证关系和正确认识与理解新形势下的院长负责制等问题。     

Construct Validity of a Kinesiophysical Functional Capacity Evaluation Administered Within a Worker's Compensation Environment

The construct validity of a kinesiophysical Functional Capacity Evaluation (FCE) administered within a worker's compensation context was examined. A cross-sectional study design was employed. Clinical and demographic information on workers' compensation claimants was extracted from a rehabilitation facility's database. Measures of interest were the Isernhagen Work Systems' (Duluth, MN) FCE, the Pain Disability Index (PDI), and a pain visual analogue scale (VAS). A multitrait Pearson correlation matrix was created to observe the pattern of relationships between variables. The sample consisted of 321 subjects with work-related, medically stable low back pain of median duration of 307 days. FCE performance was moderately correlated with the PDI (r = –0.44–0.52) and with the pain VAS (r = 0.34–0.45). Pain intensity was correlated highly with the PDI (r = 0.79). The moderate relationship between FCE and the PDI supports the construct validity of FCE as a functional measure. However, kinesiophysical FCE performance was not unrelated to pain severity ratings as purported.     

Hospital efficiency targets

Cost-efficiency targets, used to encourage downward pressure on hospital unit costs, have been employed within the UK NHS for many years. There has been considerable speculation that these targets create incentives to reduce beds and increase occupancy rates at the expense of holding spare capacity to accommodate fluctuations in emergency admissions. This research used panel data for the period 1994/1995-1999/2000, supplemented by a series of semi-structured interviews, to explore the strategies Trusts employ to reduce unit costs. No relationship could be found between published targets and changes in unit costs, nor that targets were successful in reducing the dispersion of unit costs over time. Interviews revealed that efficiency gains required of Trusts, usually dictated by the local health economy, often bore no correspondence to the national or regional published targets. Results further indicated that contrary to prior speculation, Trusts divide into two distinct groups, those with high occupancy rates and those with a high proportion of free beds to accommodate emergencies, with Trust characteristics displaying stability over time. A pressing need for future work is the development of measures to encourage efficiency that take account of quality improvement.     

Single and choice reaction time during prolonged exercise in trained subjects: influence of carbohydrate availability

The aim of the present study was to examine the effects of prolonged exercise at the ventilatory threshold and carbohydrate ingestion on single (SRT) and choice (CRT) reaction time. Eight well-trained triathletes completed three testing sessions within a 3-week period. Maximal oxygen uptake was determined in the first test, whereas the second and the third sessions were composed of a 100-min run (treadmill 15 min, overground 70 min, treadmill 15 min) performed at the velocity associated with the ventilatory threshold. During these submaximal tests, the subjects ingested (in random order) 8 ml·kg^–1 body weight of either a placebo (Pl) or 5.5% carbohydrate (CHO) solution prior to the first submaximal run and 2 ml·kg^–1 body weight every 15 min after that. The cognitive tasks were performed before and after exercise for CRT, and before, during each submaximal run and after exercise for SRT. Furthermore, at the end of each submaximal test subjects were asked to report their rating of perceived exertion (RPE). Results showed a significant positive effect of CHO ingestion on RPE and CRT performance at the end of exercise, while no effect of exercise duration was found in the Pl condition. After a 100-min run, during the CHO condition, CRT mean (SD) group values decreased from 688.5 (51) ms to 654 (63) ms, while during the Pl condition, RPE mean group values increased from 11 (2) to 16 (1.02) and CRT mean values remained stable [688 (104) ms vs 676 (73.4) ms, P>0.05]. No similar effect was observed for SRT. These results suggest that CHO-electrolyte ingestion during a100-min run results in an improvement in the complex cognitive performance measured at the end of that run. Electronic Publication     

Cholesterol esterase activities in commercial pancreatic enzyme preparations and implications for use in pancreatic insufficient cystic fibrosis

BACKGROUND: Although clinical symptoms in pancreatic insufficiency are often dramatically improved by pancreatic preparations, these often fail to normalize biochemical indicators of malabsorption. It seemed relevant, therefore, to investigate the amounts of cholesterol esterase in these preparations and, using in-vitro methods, some of the activities of this enzyme. The enzyme is just as physiologically important as lipase in accomplishing lipid digestion and absorption. METHODS: Cholesterol esterase was assayed in commercial pancreatic extract preparations, lyophilized pig pancreas and human duodenal fluid. The in-vitro activities of the enzyme were also investigated on single and mixed dietary substrates. RESULTS: Other than Creon, the commercial preparations showed negligible cholesterol esterase activities, whereas considerable activities were found in pancreatic tissue and duodenal fluids. In-vitro, pig cholesterol esterase was confirmed to be dependent on 3-hydroxy bile salt concentration for hydrolysis and synthesis and that the rate for hydrolysis greatly exceeds that of synthesis in normal concentrations of bile salts. However, with mixed lipid substrates, no bile salt concentration was found at which hydrolysis or synthesis predominates. CONCLUSIONS: When pancreatic or hepato-biliary function is compromised, optimum lipid hydrolysis may not be achieved in therapeutic use, and the pig enzyme may perform differently to the human enzyme. In-vivo trials may reveal whether augmentation of the commercial products with this enzyme would be worthwhile.     

The effects of unit morale and interpersonal relations on conflict in the nursing unit

BACKGROUND: Health care organizations face major changes, and these changes are likely to increase conflict in organizations. Although numerous studies have focused on conflict management, few have considered causes and effect of conflict in nursing units. METHODS: The investigation tested a structural equation that examined the relationships among individual and contextual variables and intragroup conflict, job satisfaction, team performance effectiveness, and anticipated turnover. The nonrandom sample consisted of 141 nurses employed on 13 inpatient units at a state-supported, 597-bed academic medical centre in a southeastern city. RESULTS: Intragroup conflict was higher on smaller units with a higher ratio of RNs to total staff. Intragroup conflict was not associated with satisfaction with pay or anticipated turnover. In the final model, the unit morale and interpersonal relations dimension of team performance effectiveness was negatively associated with intragroup conflict and anticipated turnover, and positively associated with satisfaction with pay. High perceptions of unit morale and interpersonal relations buffered the effect of unit size and skill mix on intragroup conflict. Goodness of fit statistics indicated a good fit of the model to data. CONCLUSION: The findings have implications for nursing educators and administrators, and provide direction for future research.