我国食品放射性含量及其所致居民内照射剂量估算

为获得我食品和膳食中放放射性核素含量并为制定?食品中放射性物质限制浓度标准?提供依据,在1982～1086年问由30个辐射防护单位协作,测定了我过14类(27种)特定食品种22种放射性核素浓度.按我国三种主要膳食食类型．从14个正常本底辐射的省或自治区及三个非正常地区采集样品进行分析测定.估算了这些地区居氏15种放射往核素的年摄人最及所致待积剂量毒量.我国正常本底辐射地区成年男子对这15种核索年总摄入量约为4．2×10⁴Bq,所致总待积剂量当量约为0．43×10⁴Sv.在两个天然放射性较高地区天然放射性核素的年摄入量和所致待积剂量当量比正常本底辐射地区高得多,而在该核工厂周围地区采集的食未明显放射性污染.文章还讨论了各类食品或放射性核素对总待积剂量当量的相对贡献.     

The relationship between receptor-effector unit heterogeneity and the shape of the concentration-effect profile: Pharmacodynamic implications

The apparent concentration-effect relationship is the ensemble of many effector units (such as individual cells or channels) that do not always exhibit a uniform stimulus-effect relationship. This concept is substantiated by many observations of heterogeneity in receptor-effector populations including hormone secreting cells, response to hormonal stimuli, activity pattern of second messengers, stimulus-evoked synaptic currents, and single ion channels. The relationship between drug concentration and magnitude of pharmacologic response is commonly described by the sigmoidalE _max model which was derived from the Hill equation. The sigmoidicity factor (N) in this model is assumed to be a pure mathematical parameter without physiological connotations. This work demonstrates that the numerical value ofN (measured empirically) is the product of two factors: (i) the degree of heterogeneity of the effector subunits, i.e., the elemental component that upon drug stimulus contributes its pharmacological effect independently and does not interact with other subunits (it could range from a single receptor up to a whole tissue), and (ii) value ofN ^*—the shape factor of the subunits' concentration-effect relationship. A special case of this approach occurs whenN ^*>5, which is an on-off case. HereN is determined by the distribution (density equation) of the subunit values. In case of heterogeneity of the microparameters of the effector subunits the apparentN will always have a lower value thanN ^*. According to this theory it can be concluded that without knowledge of the distribution of the microparameters no mechanistic interpretation can be deduced from the apparentN value. If in the futureN ^* can be determined by theoretical or experimental methods, the distribution function relatingN ^* toN can be calculated. The relevance of this theory is increased in view of the progress being made in advanced research techniques which may enable us to determine the concentration-effect relationship at the level of the individual effector unit.     

A 500‐ml plastic bottle: An effective spacer for children with asthma

Inhaled therapy using a metered‐dose inhaler (MDI) with attached spacer has been increasingly recognized as the optimal method for delivering asthma medication for acute attacks and chronic prophylaxis. However, in developing countries the cost and availability of commercially produced spacers limit the use of MDI‐spacer delivery systems. A 500‐ml plastic bottle has been recently adapted to function as a spacer. This article reviews the current data on the efficacy of this bottle‐spacer and discusses its advantages and limitations. It is concluded that a modified 500‐ml plastic bottle is an effective spacer; modification and use of this device should be incorporated into international guidelines for the management of children with asthma.     

几种抗艾滋病中药有效成分对解脲支原体和白色念珠菌体外抑制作用的实验研究

目的筛选对解脲支原体和白色念珠菌体外有明显抑制作用的抗H IV中药有效成分,为治疗H IV继发感染或性病奠定基础。方法以微量稀释法测定9种中药有效成分对解脲支原体和白色念珠菌的M IC50和M IC90,同时测定其中6种中药有效成分对H IV-1的EC50和TI值。结果所测药物对解脲支原体、白色念珠菌及H IV-1均有一定的抑制作用,对解脲支原体和白色念珠菌作用最好的分别是三七总皂苷、三七叶皂苷和化合物A,化合物A对H IV-1的抑制作用最好,其EC50为0.09,TI值大于10 000。结论化合物A对解脲支原体、白色念珠菌及H IV-1的抑制效果最好,值得进一步研究。     

民航飞行员的个性心理特征研究

目的探讨民航飞行员个性特点倾向及心理健康状况。方法对某公司飞行部94名现役飞行员用EPQ问卷(成人版)及SCL-90进行调查,并与全国常模比较。结果民航飞行员P、N分明显低于常模,E分明显高于常模,并具有显著性差异(P<0.005)。在SCL-90各项因子得分上均低于常模,除恐怖因子外,其余各因子得分比较都具差异显著性(P<0.005)。结论民航飞行员具有良好的个性特征及良好的心理健康状态。     

Infection dynamics and virus-induced apoptosis in cell culture-based influenza vaccine production—Flow cytometry and mathematical modeling

Cell culture-based influenza vaccine manufacturing is of growing importance. Depending on virus strains, differences in infection dynamics, virus-induced apoptosis, cell lysis and virus yields are observed. Comparatively little is known concerning details of virus–host cell interaction on a cellular level and virus spreading in a population of cells in bioreactors. In this study, the infection of MDCK cells with different influenza A virus strains in lab-scale microcarrier culture was investigated by flow cytometry. Together with the infection status of cells, virus-induced apoptosis was monitored. A mathematical model has been formulated to describe changes in the concentration of uninfected and infected adherent cells, dynamics of virus particle release (infectious virions, hemagglutinin content), and the time course of the percentage composition of the cell population.     

东北地区农民工心理健康状况的调查与分析

目的为了解东北地区农民工的心理健康状况。方法采用SCL-90、EPQ，随机抽取东北地区四个城市470名民工进行调查，并与国内常模进行比较。结果农民工SCL-90的9个因子分均值及阳性项目数均显著高于国内常模（P〈0．001），女性民工有5个因子分均值及阳性项目数显著高于男性民工（P〈0．05）zEPQ农民工组的P、E分量表得分均显著高于常模组（P〈0．001），女性农民工N分量表得分显著高于男性（P〈0．05）。结论东北地区农民工心理健康水平低于全国正常人的平均水平，女性农民工心理健康水平低于男性。     

卵巢低反应患者大剂量超排卵的助孕结局

在辅助生殖助孕中通常采用控制性卵巢刺激(controlled ovarian hyperstimulation, COS),以获得适当数量的卵子用于体外受精,既希望获得理想的辅助生殖助孕成功率,又能降低卵巢过度刺激并发症.COS中约有9%~24%[1,2]的卵巢低反应发生率.卵巢低反应者获得有效卵子数少、可移植胚胎数少或无胚胎移植、取消治疗周期率高,累计成功率更低等,导致较差的治疗结局,是辅助生殖助孕中面临的棘手问题.针对卵巢低反应者,大多数辅助生殖中心仍会采用增加促性腺激素(Gn)的起始和(或)总用量以期获得提高助孕结局的目的.而大剂量Gn是否为改善低反应患者助孕结局的有效策略却仍存在争议.     

Successful treatment of periungual warts using photodynamic therapy: a pilot study

AIM: The aim of this pilot study was an investigation on photodynamic therapy (PDT) whether it is a good alternative for treating periungual and subungual warts of the hands. STUDY DESIGN: Twenty patients (mean age: 30.5 years) with a total of 40 periungual and subungual warts were treated with PDT. A photosensitizer, 20%delta-aminolevulinic acid was applied on the warts. After a mean incubation time of 4.6 h (SD: 1.2), the warts were irradiated with the VersaLight for 5-30 min (15.2 +/- 4.3 min). RESULTS: After a mean of 4.5 treatments a mean clearance of 100% was achieved in 90% of the patients. One patient (5%) showed a clearance of 50% and another showed no improvement. The subungual or periungual location of the wart had no influence on the number of treatments or end result (P > 0.05). There were two recurrences during the mean follow-up period of 5.9 months (SD: 7.6). Besides mainly pain and hyperpigmentation, most treatments had no side-effects. CONCLUSION: PDT can offer a good alternative for treating periungual warts of the hands. Larger studies are indicated.