阿斯匹林对小鼠正常体温的降低作用及其昼夜节律变化

一般认为水杨酸类药物仅降低处于高热状态的体温而不影响正常体温。但本文实验表明,大剂量阿斯匹林(ASP)(200mg·kg^-1,ip)使雄性ICR小鼠的正常体温明显下降,且该作用呈昼夜节律性变化。ASP用药后血浆水杨酸浓度也呈昼夜变化,但与药物的体温降低作用无明显的正相关关系。提示ASP用药后的体温降低作用的昼夜节律主要与动物体温的昼夜节律相关。     

Experimental and Monte Carlo-based determination of the beam quality specifier for TomoTherapyHD treatment units

Reference dosimetry by means of clinical linear accelerators in high-energy photon fields requires the determination of the beam quality specifier TPR_20,10, which characterizes the relative particle flux density of the photon beam. The measurement of TPR_20,10 has to be performed in homogenous photon beams of size 10 × 10 cm² with a focus-detector distance of 100 cm. These requirements cannot be fulfilled by TomoTherapy treatment units from Accuray. The TomoTherapy unit provides a flattening-filter-free photon fan beam with a maximum field width of 40 cm and field lengths of 1.0 cm, 2.5 cm and 5.0 cm at a focus-isocenter distance of 85 cm.For the determination of the beam quality specifier from measurements under nonstandard reference conditions Sauer and Palmans proposed experiment-based fit functions. Moreover, Sauer recommends considering the impact of the flattening-filter-free beam on the measured data.To verify these fit functions, in the present study a Monte Carlo based model of the treatment head of a TomoTherapyHD unit was designed and commissioned with existing beam data of our clinical TomoTherapy machine. Depth dose curves and dose profiles were in agreement within 1.5% between experimental and Monte Carlo-based data.Based on the fit functions from Sauer and Palmans the beam quality specifier TPR_20,10 was determined from field sizes 5 × 5 cm², 10 × 5 cm², 20 × 5 cm² and 40 × 5 cm² based on dosimetric measurements and Monte Carlo simulations. The mean value from all experimental values of TPR_20,10 resulted in $\overline{{\mathrm{TPR}}_{20,10}}=0.635\pm 0.4\%$. The impact of the non-homogenous field due to the flattening-filter-free beam was negligible for field sizes below 20 × 5 cm². The beam quality specifier calculated by Monte Carlo simulations was TPR_20,10 = 0.628 and TPR_20,10 = 0.631 for two different calculation methods.The stopping power ratio water-to-air $s_{w,a}^{\Delta }$ directly depends on the beam quality specifier. The value determined from all experimental TPR_20,10 data was $s_{w,a}^{\Delta }=1.126\pm 0.1\%$, which is in excellent agreement with the value directly calculated by Monte Carlo simulations. The agreement is a good indication that the equations proposed by Sauer and Palmans are able to calculate the beam quality specifier under reference conditions from measurements in arbitrary photon field sizes with high accuracy and are applicable for the TomoTherapyHD treatment unit.     

增生性玻璃体视网膜病变眼玻璃体中白细胞介素、肿瘤坏死因子含量变化及意义

目的探讨白细胞介素-12(interleukin-12,IL-12)、白细胞介素-2(interleukin-2,IL-2)、肿瘤坏死因子(tumor necrosis factor,TNF)在增生性玻璃体视网膜病变(prolifｅrative vitreoretinopathy,PVR)发病中的作用。方法PVR-18只眼于冷冻及玻璃体切割前经睫状体平坦部在显微镜直视下抽取玻璃体,单纯黄斑裂孔性视网膜脱离7只眼于玻璃体内注气前抽取玻璃体,对照眼4只于睫状体平坦部抽取玻璃体。玻璃体取出后－70 ℃冻存。用酶联免疫吸附试验(enzyme-linked immunosorbent assay,ELISA)检测其IL-12、IL-2及TNF,其结果用t检验、线性回归进行比较。结果①PVR眼玻璃体 中IL-12、IL-2、TNF的浓度(分别为73.5±64.4、456.3±347.0、460.7±437.6)与病变程度呈正相关性;②PVR组中IL-12、IL-2、TNF的浓度比单纯黄斑裂孔性视网膜脱离组相应值(分别为19.4±12.9、92.9±71.4、44.2±42.2)高(P<0.01);③单纯黄斑裂孔性视网膜脱离组中IL-12、IL-2、TNF的浓度比对照组相应值（未检测出IL-12、IL-2、TNF,各值为0）高。结论细胞因子IL-12、IL-2、TNF在PVR的发病中有一定的作用。(中华眼底病杂志,1999,15:75-77)     

糖尿病及非糖尿病视网膜病变患者玻璃体中 基质金属蛋白酶的表达

目的比较糖尿病视网膜病变(diabetic vitreoretinopathy, DR )及非糖尿病视网膜病变(non-DR)患者玻璃体中基质金属蛋白酶(matrix metalloprote inase, MMP)表达及活性;并探讨MMP表达的相关因素。方法以31例DR、17例non-DR(9例黄斑裂孔,8例视网膜前膜)玻璃体为样本,采用明胶酶谱(Zy mography)技术检测样本中MMP-2、9,并用Western印迹杂交方法证实MMP-2、9表达。结果所有样本中都检测到MMP-2表达,其中DR玻璃体中MMP-2活 性略高于non-DR,但差别无显著性意义。45．2%的DR玻璃体样本中有MMP-9表达,而 non-DR玻璃体样本中无一例有 MMP-9表达。DR玻璃体样本中,部分性玻璃体后脱离(post erior vitreous detachment, PVD)MMP-9表达的阳性率(66．7%)明显高于完全性PVD者( 15．4%)(P<0．01)Western印迹杂交结果进一步证实了MMP-2、9表达。结论DR及non-DR玻璃体样本中MMP-2活性无明显差异;non-DR玻璃体样本中未见MMP-9表达,而DR玻璃体样本中MMP-9表达率与部分性PVD密切相关。MMP-9可能与DR的发生有关。(中华眼底病杂志,2001,17:195-197     

Androgens and male aging：current evidence of safety and efficacy

Many signs of aging,such as sexual dysfunction,visceral obesity,impaired bone and muscle strength,bear a close resemblance to features of hypogonadism in younger men. The statistical decline of serum testosterone in aging men is solidly documented. It has been presumed that the above features of aging are related to the concurrent decline of androgens,and that correction of the lower-than-normal circulating levels of testosterone will lead to improvement of symptoms of aging. But in essence,the pivotal question whether the age-related decline of testosterone must be viewed as hypogonadism,in the best case reversed by testosterone treatment,has not been definitively resolved. Studies in elderly men with lower-than-normal testosterone report improvement of features of the metabolic syndrome,bone mineral density,of mood and of sexual functioning. But as yet there is no definitive proof of the beneficial effects of restoring testosterone levels to normal in elderly men on clinical parameters. Few of these studies meet as yet rigorous standards of scientific enquiry：double-blind,placebo-controlled design of the study. The above applies also to the assessment of safety of testosterone administration to elderly men. There is so far no convincing evidence that testosterone is a main factor in the development of prostate cancer in elderly men and guidelines for monitoring the development of prostate disease have been developed. It is of note that there are presently no long-term safety data with regard to the prostate. Polycythemia is another potential complication of testosterone treatment. It is dose dependent and can be managed with dose adjustment.     

Does IMRT increase the peripheral radiation dose? A comparison of treatment plans 2000 and 2010

It has been reported in several papers and textbooks that IMRT treatments increase the peripheral dose in comparison with non-IMRT fields. But in clinical practice not only open fields have been used in the pre-IMRT era, but also fields with physical wedges or composed fields. The aim of this work is to test the hypothesis of increased peripheral dose when IMRT is used compared to standard conformal radiotherapy. Furthermore, the importance of the measured dose differences in clinical practice is discussed and compared with other new technologies for the cases where an increase of the peripheral dose was observed.For cancers of the head and neck, the cervix, the rectum and for the brain irradiation due to acute leukaemia, one to four plans have been calculated with IMRT or conformal standard technique (non-IMRT). In an anthropomorphic phantom the dose at a distance of 30 cm in cranio-caudal direction from the target edge was measured with TLDs using a linear accelerator Oncor ^® (Siemens) for both techniques. IMRT was performed using step-and-shoot technique (7 to 11 beams), non-IMRT plans with different techniques.The results depended on the site of irradiation. For head and neck cancers IMRT resulted in an increase of 0.05 - 0.09% of the prescribed total dose (Dptv) or 40 - 70 mGy (Dptv = 65 Gy), compared to non-IMRT technique without wedges or a decrease of 0.16% (approx. 100 mGy) of the prescribed total dose compared to non-IMRT techniques with wedges.For the cervical cancer IMRT resulted in an increased dose in the periphery (+ 0.07% - 0.15% of Dptv or 30 - 70 mGy at Dptv = 45 Gy), for the rectal cancer in a dose reduction (0.21 - 0.26% of Dptv or 100 - 130 mGy at Dptv = 50 Gy) and for the brain irradiation in an increase dose (+ 0.05% of Dptv = 18 Gy or 9 mSv). In summary IMRT does not uniformly cause increased radiation dose in the periphery in the model used.It can be stated that these dose values are smaller than reported in earlier papers. Slightly increased additional radiation dose in the periphery is likely to be counterbalanced by the much higher conformity and the often better homogeneity.     

Health-related quality of life and colorectal cancer-specific symptoms in patients with chemotherapy-refractory metastatic disease treated with panitumumab

Purpose  

Panitumumab monotherapy is approved for chemotherapy-refractory wild-type KRAS metastatic colorectal cancer (mCRC). Patient-reported outcomes—although important in the palliative setting—have not been reported in this patient population.     

中药玉竹有效成分研究

自江苏海门产百合科植物玉竹[Polygonatum odoratum(Mill.)Druce]根茎的乙醇提取物中分得六个单体化合物,根据化学性质和光谱解析,鉴定其化学结构分别为β-谷甾醇(S-A)),β-谷甾醇-3-O-β-D-吡喃葡萄糖甙(S-B),25(R,S)螺甾-5-烯-3β-醇-3-O-β-D-吡喃葡萄糖基-(1→2)-[β-D-吡喃木糖基-(1→3)]-β-D-吡喃葡萄糖基(1→4)-β-吡喃半乳糖甙(POD-I),25(R)螺甾-5-烯-3β,14a-二醇-3-0-β-D-吡喃葡萄糖基-(1→2)-[β-D-吡喃木糖基-(1→3)]-β-D-吡喃葡萄糖基-(1→4)-β-D-吡喃半乳糖甙(POD-II),25(R,S)螺甾-5-烯-3β,14a-二醇-3-O-β-D-吡喃葡萄糖基-(1→2)-[β-D-吡喃葡萄糖基-(1→3)]-β-D-吡喃葡萄糖基(1→4)-β-D-吡喃半乳糖甙(POD-III)和25(R,S)螺甾-5-烯-3β-醇-3-O-β-D-吡喃葡萄糖基-(1-2)-[β-D-吡喃葡萄糖基-(1→3)]-β-D-吡喃哺葡萄糖基(1→4)-β-D-吡喃半乳糖甙(POD-IV)。POD-II为首次分离得到的25(R)构型的纯品,POD-III和POD-IV为首次从玉竹中得到。经初步药理实验显示,POD-II有诱生集落刺激因子(CSF)的作用,POD-III能协同ConA和Lps对淋巴细胞转化有促进作用。     

Applicability of LLD in neutron dosimetry

The applicability of LLD in neutron dosimetry was tested and the optimum materials were determined. Investigations have been performed on lyoluminescence variations in sensitivity (X-rays and neutrons) for five different materials: the polyalcohols, mannitol and xylitol, the saccharides, trehalose and glucose and the amino acid, leucine. The decisive factor for the choice of a dosimetric material is its tissue equivalence. The results show striking differences in neutron and gamma sensitivities between the dosimetric materials. The different sensitivities for fast neutrons and gamma-rays can be used for simultaneous determination of neutron and gamma doses in mixed neutron photon radiation fields. The successful application of this dosimetric method can be shown by phantom- and in-vivo-measurements.