非小细胞肺癌的放疗剂量分割

 放疗是非小细胞肺癌（NSCLC）重要的局部治疗方法。近年来,随着分子生物学、放疗技术的发展及设备的更新,不同剂量分割的放疗模式及放化疗综合治疗的理念逐渐应用于临床,并取得了较好的效果。     

不同方式治疗鼻咽癌的远期疗效分析

目的 :回顾性分析比较不同方式治疗鼻咽癌患者的远期疗效 ,并分析其它相关因素对其预后的影响。方法 :从 1988年 1月至 1996年 3月共收治住院 895例首程根治鼻咽癌患者。根据不同的治疗方法 ,分为常规放疗组、腔内放疗组、超分割放疗组和同期放化疗组。结果 :(1)本组病例总的 5年生存率为 5 0 6 4 % ,总的 10年生存率为 2 3 .2 9% ;其中常规组、腔内组、超分割组和同期放化疗组的 5年总生存率分别为 4 7. 33%、5 2. 6 7%、5 8. 82 %和 5 8 .85 % (P <0. 0 5 )。 (2 )Ⅰ、Ⅱ、Ⅲ、Ⅳ期病例的 5年总生存率分别为 88 89%、76 88%、5 6 . 6 7%和 31 .95 % (P <0 0 0 0 1)。 (3)局部控制率分别为 :常规组 83 95 %、腔内组 89. 4 0 %、超分割组 92. 4 5 %和放化疗组 96 . 0 6 %。 (4)用多因素逐步回归分析 ,N分期对生存率的影响最大 (P <0. 0 0 0 1) :不同的放疗方式及T分期对生存率亦有影响 (P <0 .0 5 ) ;加用化疗能提高生存率 (P <0 . 0 1)。结论 :采用不同的放疗方式 ,对生存率及局控率有影响 ;根治性放射治疗联合同期化疗对于N分期晚的鼻咽癌的远期疗效似有提高的趋势。     

An experimental evaluation of three preoperative radiation regimens for resectable rectal cancer

Background We investigated the degree of tumor cell killing after radiotherapy regimens commonly used in clinical practice in comparison with an accelerated schedule. Methods Mtln3 mammary adenocarcinoma tumor cells were inoculated subcutaneously in the hind leg of syngeneic Fischer 344 rats. Tumors were irradiated with 5×5 Gy in 5 days, 10×3 Gy over 10 days, or 5×(2×3) Gy in 5 days. After excision of the irradiated tumors, the dye exclusion, a tetrazolium-based colorimetric and the clonogenic assays were used to determine tumor cell viability and surviving fractions. Results Estimated potential doubling time values indicate a rapid proliferation capacity, comparable with potential doubling time values in human rectal cancer. The dye exclusion and clonogenic assays revealed a significantly higher degree of cell killing after the hypofractionated and the accelerated regimens of, respectively, 5×5 Gy and 5×(2×3) Gy over 5 days compared with 10×3 Gy over 10 days. Conclusions A shorter treatment time offered the best therapeutic efficacy. The schedule involving two daily fractions of 3 Gy over 5 days should be less toxic than 5×5 Gy and may therefore provide a therapeutic advantage.     

Fractionation of Aloe vera L. inner gel, purification and molecular profiling of activity

Products derived from the inner gel of the Aloe vera L. plant have demonstrated multiple clinical activities, and are used routinely to accelerate wound healing. However, typical of natural products, the complex nature of Aloe vera gels may contribute to diverse pharmacologic activities. Our focus on the hematopoietic activities of Aloe vera extracts is extended by these functional studies, which used purified fractions from Aloe vera gel and included a preliminary organ-specific in vitro molecular profile. Studies using a >99% pure carbohydrate fraction from Aloe vera extracts revealed increased hematopoietic and hematologic activity compared to the starting material. In addition, this fraction differentially regulated liver and lung cytokine mRNA levels, resulting in significant increases in message for hematopoietic cytokines [granulocyte colony stimulating factor (G-CSF) and stem cell factor (SCF)]. This profile of activity differed from another fraction obtained from Aloe vera, suggesting the potential for diverse pharmacologic activity. The molecular studies were undertaken using co-cultures of organ slices to limit the amount of purified material required. In summary, these studies revealed significant hematopoietic activity by both pharmacologic and molecular analysis using a >99% pure carbohydrate fraction from Aloe vera gels.     

Comparison of single,fractionated and hyperfractionated irradiation on the development of normal tissue damage in rat lung

The effect of fractionated thoracic irradiation on the development of normal tissue damage in rats was compared to that produced by single doses. Animals received a single dose of 15 Gy, 30 Gy in 10 daily fractions of 3 Gy each (fractionation), or 30 Gy in 30 fractions of 1 Gy each 3 times a day (hyperfractionation). The treatments produced minimal lethality since a total of only 6 animals died between days 273 and 475 after the initiation of treatment, with no difference in survival observed between the control and any of the 3 treated groups. Despite the lack of lethality, evidence of lung damage was obtained by histological examination. At times less than 180 days after treatment, the lungs of animals receiving a single dose of 15 Gy displayed more severe changes than did animals from either fractionation group. At longer times after treatment (days 261 and 475), the histological appearances within each group were changed, collagen deposits and fibrosis being the most significant observations. Animals that had received either single doses or fractionated doses had more of the pulmonary parenchyma involved than did animals that had received hyperfractionated doses. We conclude that, in the rat lung model, a total radiation dose of 30 Gy fractionated over 14 days produces no more acute lethality nor damage to lung tissue than does 15 Gy delivered as a single dose. However, long-term effects as evidenced by deposits of collagen and development of fibrosis are significantly reduced by hyperfractionation when compared to single doses and daily fractionation.     

Fractionation of visual memory: agency detection and its impairment in autism.

It is known that the adult visual memory system is fractionable into functionally independent cognitive subsystems, selectively susceptible to brain damage. In addition, there have been hints from studies with individuals with autism that these cognitive subsystems can fractionate developmentally. However, there has been a paucity of systematic investigations. The present study involves the analysis of visual memory of a population of individuals with autism and age- and VIQ-matched comparison individuals. The individuals with autism presented selective impairments in face recognition in comparison to both the age- and VIQ-matched comparison populations. In addition, they were impaired relative to the age-matched comparison group on recognition memory for potential agents (i.e. objects capable of self-propelled motion) whether they were living (cats and horses) or non-living (motorbikes). In contrast, they were selectively superior relative to the VIQ-matched comparison group on recognition memory for such objects as topographical stimuli (buildings) and leaves that clearly do not have agency. The data is interpreted in terms of reduced sensitivity to agency cues in individuals with autism and general information processing capacity.     

Heavy metals in urban soils of central Jordan: should we worry about their environmental risks?

Forty soil samples collected from central Jordan were analyzed by atomic absorption spectrophotometry for Pb, Cd, Zn, Cr, and Hg. The samples were also investigated for mineralogy using X-ray, electron, and optical microscopes. Sequential extraction procedures were used to predict the percentages of the Pb, Zn, Cd, and Cr present in each of the soil geochemical phases. The clay mineral assemblage encountered in the analyzed samples is composed of kaolinite, smectite, illite, and illite/smectite mixed-layer. The nonclay minerals of the sand-sized fraction are composed mainly of quartz and calcite as major minerals with pyroxene, biotite, and feldspars as minor minerals. The enrichment factors of the measured heavy metals Pb, Cd, Zn, Cr, and Hg in the clay fraction (<2 microm) of the collected samples are 3.1, 16.6, 1.5, 0.9, and 4.5, respectively. According to the index of geoaccumulation, the soils of the study area are considered to be moderately contaminated with respect to Cd, uncontaminated to moderately contaminated with respect to Pb, Hg, and Zn, and uncontaminated with respect to Cr. The measured metals correlated positively with the determined physicochemical factors such as pH, clay content, organic matter content, and carbonate content. The relatively high concentrations of Cd, Pb, and Hg in the soils of the study area are related to anthropogenic sources such as cement industry, fertilizers, and vehicle exhausts. It was found that Pb, Zn, and Cr are associated mainly with the residual phases and are relatively immobile. On the other hand Cd is enriched in the carbonate phase of the analyzed soil samples. It is possible to suggest the sequence of mobility for Pb, Zn, Cd, and Cr in the analyzed soil samples as the following: Cd>Pb>Cr>Zn.     

The influence of the number of fractions and of overall treatment time on local control and late complication rate in squamous cell carcinoma of the larynx

Three hundred and ten patients with $\text{T}{}_3\text{T}{}_4$ N₀, M₀ squamous cell carcinoma were irradiated with 200 kV X rays with total doses ranging from 4,900 to 6,200 rad, given in 21 to 35 fractions in 32–63 days. After a minimum follow-up period of 3 years, the local control rate was 50% ; 21 severe late complications were observed among the patients. The dependence of local control rate and of late complication rate on the dose per fraction and on overall treatment time was analyzed by various statistical methods. Whereas the late complication rate depended significantly on dose per fraction, local tumor control depended strongly on overall treatment time.     

Dose-survival characteristics of mouse jejunal crypt cells

The survival of mouse jejunal crypt cells after multiple doses of ⁶⁰Co γ-rays has been measured with the microcolony technique. Fractionation protocols were designed with common dose fractions in regimens with different fraction numbers. An average number of 152 clonogens per crypt was estimated from the experiments. The survival curve has a broad shoulder, remaining near-exponential over the initial dose range 0 to 300 rad, with initial slope ₁D₀ = 357 rad. It is not possible to distinguish between the linear-quadratic (LQ) and two-component (TC) survival models on the basis of the results of these experiments.