Electron bolus design for radiotherapy treatment planning: bolus design algorithms.

Computer algorithms to design bolus for electron beam radiotherapy treatment planning were investigated. Because of the significant electron multiple scatter, there is no unique solution to the problem of bolus design. However, using a sequence of operators, a bolus can be designed that attempts to meet three important criteria: adequate dose delivery to the target volume, avoidance of critical structures, and dose homogeneity within the target volume. Initial calculation of bolus shape was based upon creation operators forcing either the physical or the effective depths of the distal surface of the target volume to a specified value. Modification operators were then applied to the bolus to alter the shape to better meet the design criteria. Because the operators each address a single dosimetric issue, they can often adversely affect some other attribute of the dose distribution. In addition, an extension operator is used to design the bolus thickness outside the target volume. Application of these operators is therefore carried out in certain sequences and each may be used more than once in the design of a particular bolus. The effects of these operators on both the bolus and the resulting dose distribution are investigated for test geometries and patient geometries in the nose, parotid, and paraspinal region.     

战伤绿脓杆菌感染源及防治研究

本文对云南老山前、后方医院环境及战伤感染标本中绿脓杆菌(简称PA)进行调查,对所分离的333株PA进行血清学分型及药物敏感性测定。结果可看出除炸伤时创口易被泥土中PA污染外,前、后方医院环境也是感染源之一。提示各级医疗单位在战伤救治中对PA的监控十分重要。本文结果直接有益于前、后方医院对战创伤PA的防治。     

肝癌及癌旁组织中丙型肝炎病毒基因负链的研究

运用巢式聚合酶链反应（ＰＣＲ）等方法检测了５例丙型肝炎病毒核糖核酸（ＨＣＶ—ＲＮＡ）阳性患者的肝癌、癌旁组织和周围血清中ＨＣＶ—ＲＮＡ正链和负链，其中男４例，女１例。结果，正链检测：血清及癌旁组织全部阳性，癌组织中３例阳性。负链检测：血清中均阴性，癌组织３例阳性，癌旁组织５例均阳性。本组５例患者肝脏ＨＣＶ—ＲＮＡ负链阳性，推测ＨＣＶ以ＨＣＶ—ＲＮＡ负链作为模板在感染的肝脏组织中复制，ＨＣＶ持续存在于肝脏组织中对肝癌的发生起了一定的作用。     

国人心壁内血管系统的研究——左心室壁心外膜区微血管形态计量学研究

为探察人左心室壁心外膜区微血管的三维空间构型和形态计量学指标。本研究应用微血管腐蚀铸型/扫描电子显微镜技术和酶组化(碱性磷酸酶反应)染色方法,观察10例心脏标本,得出心外膜区的毛细血管直径为7.2±1.9μm(±S.D),微血管密度是3484.44/mm~2。获得左心室壁心外膜区从微动脉-动脉端毛细血管-毛细血管网-静脉端毛细血管-“萝卜根样”微静脉这个微循环单位的三维空间构型资料。     

热疗与放疗并用治疗体表恶性肿瘤的初步探讨

本文对12例体表恶性肿瘤病人采用放射治疗与微波加热治疗并用的方法取得了较好的效果,总有效率100%。     

Genetic polymorphism of MHC class III and GLO in Chinese Yao nationality

Yao nationality is one of the minority nationalities living mainly in South China (Guangxi Province). The purpose of this study was to provide data of MHC classI and GLO in Chinese Yao nationality and the different genetic background of Yao and Han nationality, the latter representing the major nationality in China. The genetic polymorphism of MHC classI and GLO in Chinese Yao nationality was determined. Previously the Japanese were considered to have the lowest C*₂C frequencies (0.9386), but now we ascertained that the Yao have the lowest C2*C frequencies (0.9336). The data concerning gene frequencies of Yao are presented. They were also compared with the available data of Han.     

CO and particle pollution of indoor air in Beijing and its elemental analysis

Three representative types of houses in Beijing were selected and, in each type, smoking and nonsmoking households were compared, IP, RP, and CO concentrations in the living room and kitchen were monitored during each season, and the level of COHb in the heads of the households were measured. The study showed that indoor air pollution was rather severe, especially during winter, when particulate concentrations markedly exceeded the standard and CO concentration was as high as 47 ppm. Indoor air pollution was closely related to the type of house, particularly to the mode of heating. In houses, of the same type, pollution improved greatly after central heating facilities were installed. Analysis of 30 elements revealed that pollution was typically caused by coal burning, aggravated by dusty wind, but high indoor Pb levels were probably due to the use of LPG for cooking. In our study the effect of cigarette smoking was sometimes masked by the severe indoor pollution.     

Effect of ethanol on hepatotoxicity and hepatic DNA-binding of aflatoxin B1 in rats

The hepatocarcinogen aflatoxin B1 is converted to reactive metabolites that bind covalently to cellular macromolecules. These metabolites may also react with glutathione, resulting in the formation of glutathione conjugates and detoxication of the reactive metabolite. When rats were pretreated with ethanol by gastric intubation at a dose of 100 mmol/kg, 6 hr (the time of maximal GSH depletion) before the administration of aflatoxin B1, the covalent binding of 8,9-epoxide-aflatoxin B1 to DNA in vivo was increased by 47% and the hepatotoxicity was also potentiated. However, the covalent binding was not increased by pretreatment with ethanol 18 hr (time with approximately normal GSH levels) before administration of the toxin, and no potentiation of hepatotoxicity was observed. Pretreatment with a non-toxic dose of ethanol had no effects on the activity of glutathione S-transferase and glutathione peroxidase. These results suggest that the depletion of GSH and the increased formation of DNA-adduct from the liver constitute an important mechanism for the potentiation of aflatoxin B1-induced hepatotoxicity by ethanol.     

血清脂质结合唾液酸测定对肺部病变的诊断价值

本文介绍正常人113名,肺部恶性病变49例及肺部良性病变33例的血清LSA测定结果,正常人血清LSA含量平均值为0.1243±0.0358g/L。特异性97.40％,男女间无差异,48例肺癌血清LSA平均值0.2698±0.0915g/L,敏感性85.40％;33例良性病变LSA平均值0.1712±0.0767g/L,特异性78.79％。肺癌患者血清LSA较良性病变明显升高,故测定血清LSA对鉴别良恶性病变有一定价值。