Uncomfortable issues in radiation protection posed by low-dose radiobiology

This paper aims to stimulate discussion about the relevance for radiation protection of recent findings in low-dose radiobiology. Issues are raised which suggest that low-dose effects are much more complex than has been previously assumed. These include genomic instability, bystander effects, multiple stressor exposures and chronic exposures. To date, these have been accepted as being relevant issues, but there is no clear way to integrate knowledge about these effects into the existing radiation protection framework. A further issue which might actually lead to some fruitful approaches for human radiation protection is the need to develop a new framework for protecting non-human biota. The brainstorming that is being applied to develop effective and practical ways to protect ecosystems widens the debate from the narrow focus of human protection which is currently about protecting humans from radiation-induced cancers.     

Problems posed by the therapeutic use of photosensitizers in dermatology

Three phototherapeutic regimens with photosensitization are now used in dermatology: PUVA (psoralen + UVA), TUV (crude coaltar + UV), PRT (phototherapy with hematoporphyrin derivative). The efficiency of PUVA and TUV is well known in several dermatoses. PRT is now being tested experimentally. For TUV, the lack of a standardized regimen does not allow a clear-cut evaluation of the therapy. For PUVA, late side-effects, particularly carcinogenicity have to be considered. To improve efficiency and minimize the side-effects of PUVA some procedures, such as association with retino?ds, pharmaco-kinetic studies for individual adaptation of the therapeutic regimen and the use of new less mutagenic psoralens are helpful. The persistent phototoxicity following treatments with hematoporphyrin derivative constitutes the major side-effect observed, for this phototherapy.     

Legal challenges posed by the use of antimicrobials in food animal production

This review article provides a general analysis of the legal challenges presented by antimicrobial use in food animal production and the emerging public health responses to such use. The article stresses the importance of national and international law to the public health strategies and the interdependence between national and international law. The article argues that antimicrobial use in food animal production poses a challenge to the development of global health jurisprudence.     

Blood leukocyte responses to extracorporeal circulation. I. Short term extracorporeal circulation in dogs without and with extracorporeal irradiation

Short term (1 h) extracorporeal circulation without or with irradiation of blood was performed in two normal dogs in a series of experiments. The granulocyte count was constantly diminished, while the lymphocytes did not show any particular change in their concentration. In the majority of the experiments a decrease of the CFU-C content occurred to less than 70% of the initial level. There was no difference in the results of experiments with or without irradiation. In the "bag to bag" procedures, no significant change in the blood leukocyte counts including CFU-C, was established.     

体外循环中急性肺水肿分析

目的：强调重视和加强体外循环中对肺功能的保护。方法：分析16例在体外循环中发生肺水肿患者术前的肺动脉高压,血红蛋白,肾功能和心功能情况,经PEEP＋利尿药＋激素和超滤器为主,辅以强心,扩血管药的协同治疗。结果：所有患者经治疗后气道阻力下降,均减小至术前水平,无酸中毒,尿量＞100ml/min。平均2．5天拔管停呼吸机,11例患者术后第一天均顺利脱离呼吸机。15例患者出院,1例死于MOF。结论：中度肺动脉高压、贫血和心肾功能功能不全可能是体外循环中急性肺水肿的诱发因素,体外循环时应采取措施预防预防和减轻肺功能损伤。     

Hemodynamic-kinetic controlled extracorporeal circulation in heart surgery]

Mimicking the physiological characteristics of the circulatory system, pulsatile bloodflow has also been introduced into extracorporeal perfusion to avoid known postoperative complications. In a mathematical consideration of the situation bloodflow is seen as a function of time F(t) for approximately constant vessel diameter over a given time. The kinetic energy of a column of blood produced by the heart-lung machine is transmitted directly to the arterial circulation via the aorta. The nature of the energy release can give rise to both positive (organ perfusion) and negative (damage to endothelium) effects. This study investigates how this energy release can be optimised, using the following experimental approach. A Doppler flow-measuring probe is placed on the ascending aorta to monitor the extracorporeal circulation. At the same time, the blood pressure is measured and converted to a pressure-flow curve via an A/D converter. On the basis of the parameters thus obtained, the energy released by the heart-lung machine is calculated. By regulating the functional parameters of a new generation of heart-lung machines, the bloodflow can then be adapted to the physiological requirements. Within the pulse period (cycle) a 20% rise phase ending in a slightly increasing plateau is established. The energy increase within a cycle should not exceed 150 joules. To optimize the mode of functioning of the heart-lung machine, we introduced the "energy-equivalent pressure" (EEP). Adaptation of the EEP to the physiological conditions required a basic flow of 60% at a pulse rate of 60/min and a pulse duration of 35% within the pulsatile flow interval.     

Variations in plasma protein components during extracorporeal circulation

In this research we have determined the behaviour of proteic plasmatic pattern and some enzymes during extracorporeal circulation and we noted a constant increase of albumin and of the ratio Alb/Glob. We observed also variations of some enzymes. Our opinion according other AA. is that this changes are determined principally by the large dose of heparin necessary during the C.E.C.