Human sympathetic nerve activity to glabrous skin does not increase during simulated diving

In humans, cardiovascular adjustment to simulated diving causes a marked increase in sympathetic outflow to intramuscular vessels and muscle vasoconstriction. Skin vasoconstriction in the hand also occurs during diving in humans. Skin nerve sympathetic activity (SSA), containing vasoconstrictor signals to glabrous skin, unexpectedly was reduced during diving in a previous study of SSA recorded in the peroneal nerve. SSA was recorded by microneurography in the median nerve in 13 healthy volunteers during simulated diving. Skin blood flow in the hand and one finger was monitored. The typical SSA response, irrespective of duration of diving and water temperature, was an increase during the control period immediately prior to immersion of the face and a sudden reduction of SSA when the face was immersed. The increase in SSA preceding the dive was accompanied by vasoconstriction, which continued during the dive, but re-dilation regularly occurred before the end of the dive. Inhibition of SSA was not total. Mental arithmetic during diving evoked strong bursts of SSA, similar to those seen normally during mental stress. It is concluded that the true response of SSA to simulated diving is an inhibition of the immediately preceding outflow, in agreement with observations of cutaneous blood flow in animals. The skin vasoconstriction recorded during simulated diving is a consequence of an SSA increase before the procedure, suggested to be a stress response before the forthcoming manoeuvre. The SSA response during simulated diving is the opposite to that of sympathetic outflow to muscle, which emphasizes the diversity of sympathetic regulation of different organ systems.     

A Hemodynamically Responsive Antitachycardia System: Theoretical Bases for Design

Current antitachycardia systems such as the automatic implantable cardioverter/defibrillator (AICD), detect tachyarrhythmias primarily by sensing rate and thereby perform inadequately in differentiating hemodynamically stable from unstable arrhythmias. As a result, these devices may discharge during stable tachycardias (such as sinus tachycardia), causing discomfort to the patient and depleting the device's limited energy supply. If a parameter which could reflect the particular hemodynamic state of a tachycardia were incorporated into the sensing algorithm of these systems, function may be more hemodynamically precise and discharge specificity may be improved.     

医学技术的进步与传统医学伦理的矛盾

此文全面论述了先进医学技术给传统医学伦理的医患关系模式、医生义务论、生命认识论、资源分配论等诸多方面带来的巨大冲击,并由此提出先进医学技术发展应遵循的伦理规则。     

Assessment of oxidative DNA damage in the oxyR-deficient SOS chromotest strain Escherichia coli PQ300.

The SOS chromotest is a simple short-term genotoxicity assay measuring the induction of gene sfiA in Escherichia coli K-12. The recent availability of SOS tester strains with additional mutations in DNA repair or protection systems allows testing of DNA damaging compounds for genotoxic specificity. E. coli PQ300 differs from the standard SOS tester strain PQ37 in that it contains an additional mutation in gene oxyR that renders it more sensitive to oxidative genotoxins. The generation of reactive oxygen intermediates (ROI) by hydroperoxides (H2O2, t-butyl hydroperoxide, cumene hydroperoxide), gamma-radiation, glucose oxidase, and xanthine oxidase resulted in a more vigorous SOS response in strain PQ300 compared to strain PQ37. PQ300 was also more sensitive than PQ37 for the detection of reducing agents such as ascorbic acid, cysteine, and glutathione, which also alter the redox status of the bacterial cells. However, intercalating agents (adriamycin, bleomycin, and mitomycin C) and the UV- and radiomimetic compound 4-nitroquinoline-1-oxide whose DNA damaging potential are known also to involve ROI did not show significant differences between strains PQ37 and PQ300. It is concluded that the oxyR-deficient strain PQ300 is useful for detecting certain classes of genotoxins that change the oxidative/antioxidative balance of tester bacteria in the SOS chromotest.     

论医学生和谐就业伦理观的培养

结合目前医学生在就业过程中出现的不和谐伦理现象,分析了其主客观原因,提出了医学生和谐就业伦理观培养的现实途径.     

利用外国政府贷款医疗项目操作程序及需要注意的问题

综合了申请利用外国政府贷款医疗项目所涉及的部门、政策规定、申请程序、工作要求等,并按照实际工作中的大体操作顺序作了较为具体的介绍。     

医生职业用语中的伦理问题

论述了医生职业语言的基本特征，分析了诊断和治疗过程两个环节中医患语言的基本特征，总结了医生职业用语基本的伦理原则。     

Assessment of the Severity of Asthma in a Family Practice

The objective of this study was to evaluate clinical history and self-perception of severity as predictors of asthma severity. A short-term longitudinal study was conducted in a family practice in Melbourne, Australia, utilizing peak flow monitoring, medication diary, and self-administered asthma severity questionnaire. Seventy-two asthmatic subjects with a positive bronchodilator or exercise test, aged between 6 and 79 years, were studied. Symptom and treatment items were correlated with peak flow variability and minimal peak expiratory flow rate (PEFR). An asthma severity scale was generated using the partial credit version of Item Response Theory and the participants' severity scores were validated against lung function tests and medication usage. Quantitative modeling procedures were used to investigate the interrelationships of factors associated with peak flow variability. Severity scores demonstrated significant relationships with peak flow variability (partial r = 0.34) and treatment items. Self-perceived severity of asthma in the preceding 2 weeks showed significant association with peak flow variability (partial rho = 0.46) and minimal PEFR (rho = -0.41). The severity module of the Monash Respiratory Questionnaire is a valid and reliable instrument. The most important symptoms appear to be the frequency of use of bronchodilator and frequency of nocturnal attacks. A carefully structured clinical history in conjunction with the peak flow criteria of variability and minimal peak flow rate would be appropriate in the evaluation of asthma severity. Patients' self-perception of the severity of their asthma needs further evaluation.     

Antibodies against dengue virus E protein peptide bind to human plasminogen and inhibit plasmin activity

Both mice and rabbits immunized with dengue virus E protein peptide spanning amino acids 100–119 (D4E) produced antibodies that reacted not only with the D4E peptide itself but also with human plasminogen, as shown by ELISA and Western blot. Sera from dengue virus-hyperimmunized mice and dengue patients also contained antibodies against D4E and plasminogen. Furthermore, such sera all contained plasmin inhibitory activity. Using affinity-purified anti-D4E antibodies and free D4E peptide for competitive inhibition, we demonstrated that the inhibition of plasmin activity was due to anti-D4E antibodies rather than other substances in the sera. Taken together, these results suggest dengue virus E protein amino acids 100–119 are a cross-reactive immunogenic region, and antibodies against this region may interfere with human fibrinolysis.     

Some Guidelines for the Use of Stimulus Modifications in Teaching Response Topography to People with Developmental Disabilities

The use of stimulus modifications in teaching involves altering the materials of a task in order to simplify its execution. Though their use in teaching stimulus discriminations to people with developmental disabilities has been extensively investigated, less attention has been given to their utilization in teaching response topography. This paper offers some general guidelines about their use for this purpose. In relation to their design, it is suggested that the aim should be to reduce the demands made by task components, to eliminate components, and/or to increase the attentional value of the discriminating features of the response topography. In relation to their application, guidelines are suggested about when they should be employed in conjunction with response prompts; when they should be used, either alone or in conjunction with response prompts, in preference to response prompts alone; whether one or a series of modifications is required; and at what point during teaching should probe trials on the unmodified task be introduced.