人体β-胡萝卜素的肠转化和吸收后转化的研究

目的 :为了解部分中国人体内 β 胡萝卜素 ( β carotene ,以下简称 β C)转化维生素A (vitaminA ,以下简称VA)的效率 ,开展了本研究。方法 :使用稳定同位素稀释法对 15名 5 0 60岁健康农村志愿者 (男 9,女6)进行β C人体代谢实验。 2周适应期和 5 6天实验期内 ,志愿者接受常规膳食 ,避免大量VA和 β C摄入以及烟、酒和营养补充剂。实验第 1天 ,给受试者含 6mg氘标记 β C( 2 H8β C)玉米油胶丸 ,随半流质早餐 (脂肪热能比 2 5 % )一起摄入。实验第 4天 ,受试者以同样方法摄入含 3mg氘标记醋酸视黄醇 ( 2 H8RAC)油剂胶丸。实验第 1天和第 4天摄入标记物后 0 ,3 ,5 ,7,9,11,13h时 ,实验第 2 ,3 ,5 ,6,7,8,9,10 ,14,2 1,2 8,3 5 ,42 ,49,5 6天晨空腹时 ,采静脉血。用高效液相色谱仪 (HPLC)分离血清 β C和VA组分 ,再分别使用气相质谱仪(GC MS)和液相质谱仪 (LC MS)测定VA和 β C组分的同位素丰度。根据VA和 β C的浓度和同位素丰度 ,描述标记VA和β C在体内应答的血液动力学曲线。 结果 :所有 15名受试者对2 H8RAC应答明显 ;但是在对2 H8β C的应答方面 ,只有 11名受试者2 H4视黄醇应答曲线明显 ,有 4名受试者血清2 H4视黄醇应答曲线非常微弱。经过对备份血清样品进行的多次重复GC MS测定 ,我们目前初步?     

Influence of stretch-shortening cycle on mechanical behaviour of triceps surae during hopping

Belli , A. & Bosco, A. 1992. Influence of stretch-shortening cycle on mechanical behaviour of triceps surae during hopping. Acta Physiol Scand 144 , 401408. Received 20 March 1 991 , accepted 3 December 1991. ISSN 0001–6772. Laboratories of Physiology, Universities of St Etienne and Lyon, France and Departments of Biology and Physical Activity, University of Jyväskylä, Finland. Six subjects performed a first series of vertical plantar flexions and a second series of vertical rebounds, both involving muscle triceps surae exclusively. Vertical displacements, vertical forces and ankle angles were recorded during the entire work period of 60 seconds per series. In addition, expired gases were collected during the test and recovery for determination of the energy expenditure. Triceps surae was mechanically modelled with a contractile component and with an elastic component. Mechanical behaviour and work of the different muscle components were determined in both series. The net muscular efficiency calculated from the work performed by the centre of gravity was 17.5±3.0% (mean ± SD) in plantar flexions and 29.9 ± 4.8% in vertical rebounds. The net muscle efficiency calculated from the work performed by the contractile component was 17.4 %% 2.9% in plantar flexions and 16.1 ± 1.47; in vertical rebounds. These results suggest that the muscular efficiency differences do not reflect muscle contractile component efficiency but essentially the storage and recoil of elastic energy. This is supported by the relationship (P < 0.01) found in vertical rebounds between the extra work and the elastic component work. A detailed observation of the mechanical behaviour of muscle mechanical components showed that the strategy to maximize the elastic work depends also on the force-velocity characteristics of the movement and that the eccentric-concentric work of the contractile component does not always correspond respectively to the ankle extension-flexion.     

铁道车祸危险因素与行车安全经济效益的探讨

作者以1380名机车乘务员为研究对象,测查其生理心理指标,探讨发生车祸的危险因素,分析34年车祸流行的规律,并对行车安全的社会经济效盖进行了估算。研究结果显示,社会安定是减少车祸、保证行车安全的重要因素。通过多因素分析,揭示车祸的危险因素是低文化程度、过度疲劳、睡眠不足、视运动反应迟钝和弱神经类型,其间存在交互作用。实践表明,推行安全行车千日活动,可获巨大社会经济效益(1∶7)。     

Preparation and evaluation of temperature sensitive liposomes containing adriamycin and cytarabine

Temperature sensitive liposomes (TSL) containing adriamycin (ADM) and cytarabine (Ara-C) were prepared. ADM and Ara-C were selected as model compounds of amphiphilic and hydrophilic drug, respectively. Encapsulation efficiency of ADM entrapped into TSL was about twice greater than that of Ara-C. It might be due to different polarity of the drugs. Lipid compositions of TSL had no effect on the encapsulation efficiency of drugs. Thermal behavior of TSL using a differential scanning calorimetry (DSC) was also investigated. Phase transition temperature (T_c) of TSL was dependent on the lipid compositions of TSL.ADM broadened thermogram of TSL but Ara-C did not. However, T_c of TSL was not changed by any drug. Release rate of drugs was highly dependent on temperature. The release profile of ADM was similar to that of Ara-C. The maximum release rate of drugs from TSL was occurred at the near T_c and observed at 39–41°C for DPPC (Dipalmitoylphosphatidylcholine) only, 52–54°C for DSPC (Distearoylphosphatidylcholine) only, 41–43°C for DPPC and DSPC (3∶1), and 43–45°C for DPPC and DSPC (1∶1), respectively. Effect of human serum albumin (HSA) on the release rate of ADM was investigated. HSA had no significant effect on the release of ADM below T_c. However, ADM release from TSL was increased at the near and above T_c. The HSA-induced leakage of drug may result from the interaction of liposomal constituents with HSA structure at the near T_c. From the fact that the release profiles of ADM from freshly prepared TSL and stored TSL for 1 week at 4°C was not changed, the TSL was considered to be stable for at least 1 week at 4°C. Based on these findings, TSL may be useful to deliver drugs to preheated target sites due to its thermal behaviors.     

苯并恶唑类化合物的研究——Ⅰ.化合物的合成及光物理性能

合成了四种结构类型的苯并恶唑化合物共15个:测试了它们的红外吸收光谱,以及它们在DMF中的紫外吸收、荧光发射和激光发射光谱。苯基取代物的荧光量子产率在0.64～0.66,无激光性能。其余的化合物荧光量子产率都大于0.70,在最大吸收波长下的激光转换效率为2.5～5.9%。     

伽玛刀治疗全身肿瘤1168例初步报告

目的 探讨国内首创的OUR-QGD全身伽玛刀治疗头、颈、胸、腹、盆腔内肿瘤的疗效。方法 应用OUR-QCD全身伽玛刀治疗头、颈、胸、腹、盆腔内肿瘤1168例，男822例，女346例，其中肺癌664例。应用西门子SOMATOM-E spring型螺旋CT行薄层扫描，获得定位图像，在γ-TPS治疗规划系统上进行三维图像重建、显示；根据肿瘤性质、类型、部位及脑干、脊髓、血管、神经、气管、食管、胃、肠、膀胱的毗邻关系制订适合的治疗计划，再行治疗方案的模拟显示，评估、修正、确定最佳治疗方案。结果 在702例随访复查资料完整的病例中，伽玛刀治疗后3～6个月复查评价其近期疗效．肿瘤局部控制率(CR PR)91．7％(644／702)；症状、体征的改善率为90．9％。放射性食管炎、放射性肺炎、放射性肠炎等并发症仅8．3％，未见穿孔致死等严重并发症病例。1年、2年生存率正在统计中。结论 伽玛刀治疗全身肿瘤等病变是一种安全、有效，并发症较少的方法。采用放化疗配合伽玛刀进行综合治疗疗效更好，更为合理。     

抗癌新药3′,5′-环胞苷二棕榈酸酯脂质体的研究

将3′,5′-环胞苷二棕榈酸酯包封于脂质体中.药效学研究表明,药物的脂质体剂型对腹水型肝癌细胞的抑制率比游离药物以及阿糖胞苷脂质体的抑制率高1倍以上.化学动力学实验显示,在pH为6.9时,脂质体中药物的分解反应速度比游离药物慢得多,其有效期比游离药物长3倍以上.用荧光法研究药物分子在脂双层上的状态,探讨了药物包封于脂质体中抗癌活性及化学稳定性提高的原因.     

Phosphate end dialysis value : a misleading parameter of hemodialysis efficiency

Despite low end dialysis serum phosphate levels (P_e) the control of phosphate retention remains often unsatisfactory in dialyzed patients. In order to assess the value of P_e in dialyzed children as an indicator of dialytic phosphate removal, we studied serum phosphate kinetics over the period of dialysis and post dialysis and compared these with urea kinetics. A multicenter study was conducted in the 21 French pediatric hemodialysis units and included 144 children under 15 years of age. Blood urea and phosphate concentrations were measured at the beginning, at 45 min later, at the end of dialysis, and 30 min post dialysis. At 60 min and at 360 min post dialysis measurements were made only for a subgroup of 12 children. From the serum levels, reduction ratios for urea (URR) and phosphate (PRR) and post dialysis rebound for urea (PDUR) and phosphate (PDPR) were calculated. URR (over the dialysis session, 72%±9%) was higher than PRR (47%±12%). Moreover, urea removal continued throughout the dialysis period, while most of the reduction in phosphate occurred in the initial dialysis period. Post dialysis urea rebound was limited to the 60th min post dialysis, whereas post dialysis phosphate rebound occurred until the 360th min post dialysis; by this time the serum phosphate levels had almost reached the predialysis levels. In summary, serum phosphate kinetics over dialysis and post dialysis periods in children appear to be misleading for the quantification of phosphate removal, i. e., phosphate clearance is a poor indicator of dialytic phosphate removal. Received September 21, 1995; received in revised form and accepted June 11, 1996     

Trends in the structure,productivity, effectiveness and unit costs of the hospital and community health services workforce in England: 1979–1991

In this paper it is shown that there have been significant structural changes in the composition of the Hospital and Community Health Services (HCHS) workforce over the 1980s. The number of doctors, nurses and other medical professionals has grown at the expense of support staff such as ancillaries and maintenance workers. The number of agency and contract staff has risen rapidly, partly offsetting the loss of directly-employed support staff. Changes in the workforce have been compared with changes in activity, as measured by the cost-weighted activity index. According to this measure labour productivity has grown by a compound rate of 1.9% annually. Adjusting the labour force index for the wage bill of each group reveals productivity growth of 1.5%. The effectiveness of treatment, as proxied by the decline in avoidable perinatal mortality, has grown by 3.4% annually. Unit labour costs have fallen over the period at an average annual rate of 0.3%. The trend conceals wide fluctuations, with labour costs falling slowly during the first half of the decade, and rising strongly during the second half. Medical professionals benefited disproportionately from wage increases in comparison with other HCHS groups during the mid to late 1980s.