The structure of memorized knowledge in students and clinicians: an explanation for diagnostic expertise

This paper provides for the first time evidence of a consistent difference in the memory structures of novice and expert clinicians. The diagnostic performance of first- and third-year clinical medical students, senior house officers, registrars and consultants on four clinical problems in general medicine was studied. Comparisons were made of all diagnostic interpretations offered and the forceful features (personally important pieces of information which act as a key to particular memory structures which in turn give rise to the clinical interpretation) from which these were derived. Results demonstrate that the numbers of interpretations made and the numbers of forceful features identified did not differ significantly between groups (P greater than 0.05). However, the actual interpretations made in three out of four cases, and the actual forceful features identified in all cases, did differ significantly between groups (P less than 0.05). The numbers of interpretations made by all groups were large and demonstrated enormous variability. Highly individualized multiple responses to clinical information are associated with easy diagnoses. We conclude that there is no difference between groups of differing clinical experience in the breadth of thought but that there are marked differences in the precise content and structure of thought. This allows coherent explanation of variation in diagnostic expertise with clinical experience. The significance of the findings is discussed.     

Comparison of the haemodynamic effects of intermittent positive pressure ventilation with high frequency jet ventilation

The cardiorespiratory effects of intermittent positive pressure ventilation and high frequency jet ventilation with and without positive end expiratory pressure were compared in patients following valvular heart surgery (mitral and/or aortic). Twenty patients received intermittent positive pressure ventilation and high frequency jet ventilation with 0, 0.5 and 1.0 kPa positive end expiratory pressure. High frequency jet ventilation was well tolerated. The addition of 1.0 kPa positive end expiratory pressure was associated with preservation of the arterial oxygen tension without any increase in shunt or significant adverse haemodynamic effect. The results are discussed and compared with a previous study of high frequency jet ventilation following aortocoronary bypass graft surgery.     

医学生营养知识与膳食状况调查

①目的了解医学生营养知识的掌握情况及对教育传播方式的需求意见，以加强营养知识教育，改善大学生的健康素质。②方法对762名在校大学生进行问卷调查。③结果医学院在校生对营养知识及常识掌握深度和广度都不够，但渴求得到营养知识的欲望比较高，对营养知识的重要性认识正确。有73．6％的学生认为营养知识对生活很重要。87．2％的学生愿意接受营养知识的教育，对营养知识教育的传播方式也表现出特有的需求意向。大学生的膳食结构不够合理，奶类、薯类、鱼虾禽类、豆制品摄入不足。④结论应加强医学生营养知识教育，使医学生做到科学合理的安排膳食，改善饮食行为，促进身体健康。     

消旋17-苯-18,19,20-失三碳前列腺素F2α甲酯及其15-差向异构体的合成

从中间体(4)出发,经醛(5),与鏻叶立德(3)或2-酮-4-苯丁烷磷酸酯(11)钠缩合成(6),再钠硼氢还原得3′α-醇(7A)及其差向异构体(7B),经硅胶柱色谱分开,分别经二异丁基铝氢还原,与溴化5-三苯鏻戊酸之Wittig试剂缩合,得17-苯-18,19,20-失三碳前列腺素F_2α(9A)及其15-差向异构体(9B),再用重氮甲烷甲酯化,分别得相应的17-苯-18,19,20-失三碳前列腺素F_2α甲酯(10A)及其15-差向异构体(10B)。     

Comparison of computer-assisted learning with tutorial teaching in a group of first-year dental students

Two identical groups of first-year dental students were instructed in the pathology of dental caries and periodontitis using computer-assisted learning (CAL) or tutorial teaching (TT). A cross-over arrangement, in which the first group was taught about dental caries by CAL and periodontitis by TT and the second group in the reverse order, allowed comparison of the two methods. The comparison included a knowledge test and completion of a questionnaire. CAL and TT were equally effective as far as acquisition of knowledge was concerned. Students felt pressurized with CAL and had problems with note-taking. They liked a teacher to be present. Nevertheless, CAL was an acceptable method of instruction and was more economical, in terms of staff involvement, than TT.     

Efficacy evaluation of gadoteridol for MR angiography of intracranial vascular lesions

A phase III multicenter study was conducted in 89 patients with known intracranial vascular lesions to evaluate an extracellular gadolinium contrast agent, gadoteridol, for intracranial magnetic resonance (MR) angiography. The pre- and postcontrast MR angiograms of 82 patients were evaluated by the unblinded investigators and by two blinded readers (A and B) for visualization of lesions; arterial and venous anatomy; extent, size, and number of lesions; and disease classification. The unblinded readers indicated that lesions were visualized better on postcontrast images in the following categories: venous anatomy, 87 (81%) of 107 lesions; arterial anatomy, 43 lesions (40%); and extent or size of lesions, 38 lesions (36%). In 29 (35%) of 82 patients, the unblinded readers determined that enhanced MR angiography provided more diagnostic information than unenhanced MR angiography. The blinded readers determined that enhanced MR angiography provided more information for visualization of vascular anatomy in more than 60% of cases. The additional information provided with gadoteridol would have changed the diagnosis in nine (8%) of 107 lesions seen by the unblinded readers, 11 (12%) of 90 lesions seen by reader A, and three (3%) of 93 lesions seen by reader B. The results confirm that the use of gadoteridol improves the visualization of intracranial vascular lesions with MR angiography. The authors conclude that development of new postprocessing algorithms will improve the utility of contrast-enhanced MR angiography.     

Raymond's syndrome following petrosal sinus sampling

Summary Inferior petrosal sinus sampling (IPSS) is used to evaluate the pituitary-dependency of Cushing's disease, and to predict the laterality of a microadenoma prior to transsphenoidal operation. A serious complication occured in a 14-year-old boy: he suffered brain stem ischaemia with abducens nerve palsy and hemiparesis (Raymond's syndrome). The case prompted us to reconsider the indication for this investigation.     

生物医学测量及控制技术新进展

介绍生物医学测量及控制技术领域中的一些研究进展。