Improvement of oxygen metabolic reserve after extracranial-intracranial bypass surgery in patients with severe haemodynamic insufficiency

Summary The effectiveness of extracranial-intracranial arterial bypass (EC-IC bypass) surgery on impaired haemodynamic status was studied in 12 patients with reduced regional cerebral perfusion pressure (rCPP) and elevated regional oxygen extraction fraction (rOEF) in the area distal to the symptomatic arterial lesion. Postoperative positron emission tomography (PET) study demonstrated a statistically significant decrease of rOEF in the operated hemispheres with disappearance of the pre-operative interhemispheric rOEF difference. Regional cerebral blood flow (rCBF) and regional cerebral oxygen metabolism (rCMRO2) were also increased in the operated hemispheres with disappearance of the pre-operative interhemispheric differences. Regional CBF/regional cerebral blood volume (rCBV) ratios of the symptomatic hemispheres were increased after surgery, but were still lower than in the contralateral hemispheres. We conclude that EC-IC bypass surgery improves impaired cerebral oxygen metabolic reserve.     

An uncommon cause of acute right ventricular failure and high mixed venous oxygen saturation

Ruptured sinus of Valsalva aneurysms are rare. We report a case in which the usual clinical manifestations were not present and the patient was initially treated as an acute pulmonary embolus. Despite three negative echocardiograms an intra-cardiac shunt was suspected because of a persistently elevated mixed venous oxygen saturation. Cardiac catheterisation confirmed the diagnosis. Surgical repair was performed and post operative recovery was uneventful.     

Teaching medical students about the appropriateness of social and sexual contact between doctors and their patients: evaluation of a programme

The purpose of this study was to assess the impact of an educational intervention on medical students' attitudes toward social and sexual contact with patients by doctors from three medical specialties (general practice, obstetrics/gynaecology and psychiatry). Medical students from two consecutive fifth year classes at one medical school participated in one 3 hour session that included instruction on the standards of the profession that prohibit doctor–patient sexual contact. Students were assigned to either intervention groups or control groups and responded to an anonymous questionnaire (overall response rate 66·8% ; n=141). As many as 14·5% of control group students thought it was (sometimes or usually) appropriate for general practitioners to date their own patients and at least 3% thought it appropriate for members of any of these three medical specialties to engage in sexual contact with their own patients. However, there were no significant differences in attitudes toward hugging, dating or sexual contact with current patients between those who had attended the seminar and the control groups. The session significantly influenced attitudes regarding obstetrician/gynaecologists and psychiatrists hugging and having sexual contact with former patients. These findings are discussed in relation to a need for expansion of such instruction.     

Teaching sociology of medicine: the group process

As a part of any curriculum reorganization, new instructional methods are also tested. When the University of Turku sociology of medicine course was found to need renovation, its goals and objectives, content and instructional methods were closely examined and modified, in order to strengthen institutional and multiprofessional relations and reinforce sociocultural issues in doctors' competence with the patient. This paper discusses this change, emphasizing teaching and learning methodology.     

Effect of pentoxifylline on veno-occlusive priapism-induced corporeal tissule lipid peroxidation in a rat model

Objective: To investigate whether pentoxifylline could play a role in attenuation of the hazardous effects of ischemia/reperfusion on corporeal tissue in a rat model of veno-occlusive priapism (VOP). Materials and methods: Placebo and pentoxifylline were given to eight groups of rats prior to priapism being induced by a vacuum constrictive device for durations of 6 and 12 h, respectively. Half of the groups of rats that underwent the same duration of priapism (ischemic) were subjected to 1 h of detumescence after band removal (reperfusion). One group underwent no manipulation and no drug administration and served as a baseline determination (control). Corporeal homogenates were examined for lipid peroxidation (LP) derived malondialdehyde (MDA) accumulation via thiobarbituric acid assay. Results: MDA concentration differed significantly between VOP rats and controls (P < 0.001) but did not differ significantly between ischemic-only groups and reperfused groups (P > 0.05). In the pentoxifyllinepretreated groups, although MDA accumulation tended to be slightly lower than in the placebo groups, the difference was not statistically significant (P > 0.05) either in the 6- or 12-h duration priapic groups. Conclusions: LP, an indicator of radical oxygen metabolite (ROM) induced injury, occurs in rat corporeal tissue during and after abolishment of VOP. Single-dose pentoxifylline pretreatment failed to exert a protective effect on corporeal tissue in a rat model of VOP in terms of attenuation of LP.     

An analysis of paediatric diagnostic decision-making: how should students be taught?

This study assesses the relative importance of history, examination and investigations in paediatric diagnosis, in the Paediatric Out-patient Department of the Central Middlesex Hospital, London, by means of a questionnaire-based record of 94 consecutive referrals. A diagnosis identical to the final diagnosis was made in 76% of referrals after taking a history. The general practitioner had proposed a diagnosis in 45% in the referral letter. Clinical examination changed the diagnosis in only 15% but increased diagnostic confidence in 33%. Ninety-one per cent of cases were diagnosed without recourse to investigations. Forty-two per cent of children referred had investigations performed. In the majority of paediatric cases the provisional diagnosis reached after taking a history was identical to that after examination or results of investigations were known. Although examination provided a final diagnosis in only 15% of all cases it played an important role in adding confidence in 33%. More educational effort should therefore be directed at clinical history-taking skills and the subsequent purpose of examination.     

医用氧舱检验与安全

本文介绍了医用氧舱的检验，医用氧舱的检验包括舱体、供排气、氧系统、电气系统等“硬件”设备的检验和设计、安装与使用管理的“软件”方面的检验。同时，针对检验过程中发现的影响医用氧舱安全使用的常见问题，本文进行了详细的讨论。     

关于加强医学生实践能力培养的研究

文章比较科学系统地提出了三种有效培养医学院校大学生实践能力的途径与方法,即以课堂教学活动为基点、以实践教学环节为中心和以课外实践活动为辅助。以期为各医学高等院校就如何加强医学生实践能力培养的问题提供有益的借鉴。     

Blockade of superoxide generation prevents high-affinity immunoglobulin E receptor-mediated release of allergic mediators by rat mast cell line and human basophils

BACKGROUND: Previous studies have shown that rat peritoneal mast cells and mast cell model rat basophilic leukaemia (RBL-2H3) cells generate intracellular reactive oxygen species (ROS) in response to antigen challenge. However, the physiological significance of the burst of ROS is poorly understood. OBJECTIVE: The present study was undertaken to investigate the role of superoxide anion in mediator release in rat and human cell systems. METHODS: RBL-2H3 cells were directly stimulated with anti-rat FcepsilonRI alpha-subunit monoclonal antibody (mAb). For the analysis of human cell system, leucocytes were isolated by dextran sedimentation from healthy volunteers or from patients, and challenged either with anti-human FcepsilonRI mAb or with the relevant antigens. Superoxide generation was determined by chemiluminescence-based methods. The releases of histamine and leukotrienes (LT)s were determined by enzyme-linked immunosorben assay (ELISA). RESULTS: Cross-linking of FcepsilonRI on RBL-2H3 cells or on human leucocytes from healthy donors by the anti-FcepsilonRI mAb resulted in a rapid generation of superoxide anion, as determined by chemiluminescence using superoxide-specific probes. Similarly, leucocytes from patients generated superoxide anion in response to the challenge with the relevant allergen but not with the irrelevant allergen. Furthermore, diphenyleneiodonium (DPI), a well-known inhibitor of flavoenzymes suppressed the superoxide generation and the release of histamine and LTC4 induced by the anti-FcepsilonRI mAb or by allergen in parallel. CONCLUSION: These results indicate that both RBL-2H3 cells and human basophils generate superoxide anion upon FcepsilonRI cross-linking either by antibody or by allergen challenge and that blockade of the generation prevents the release of allergic mediators. The findings strongly support the role of superoxide generation in the activation of mast cells and basophils under both physiological and pathological conditions. The findings suggest that drugs regulating the superoxide generation have potential therapeutic use for allergic disorders.     

Interviewing skills: self-evaluation by medical students

In an independent learning project, 52 third-year medical students carried out a structured self-assessment of two videotaped psycho-social interviews they had conducted with volunteer clients 1 year earlier, as part of a previous course. The interviews had been conducted in small tutorials with feedback from their clients, fellow students and tutors, facilitated by videotape playback. During the sequence of 16 tutorials each student had carried out an early and a late interview and had observed and participated in the discussion of the interviews of 14 peers. Students were asked to tally the frequencies of various interview behaviours, to evaluate the quality of their behaviours, and to establish priorities for future learning. The videotapes were also reliably rated by an independent observer. Students' overall self-assessments correlated 0.46 with those of the independent observer. This correlation was higher than is typically reported in studies of the validity of self-assessment. In absolute terms, the students' mean rating of interviewing performance was 3.2 (adequate plus) which was significantly lower than the observer's mean of 3.6 (adequate to good). Results are discussed in terms of Gordon's (1992) two recommendations for improving the validity of self-assessments and two further suggestions, for paired comparisons and low-threat learning environments, are added.