全波段紫外线照射对人T细胞亚群计数影响的体外研究

应用间接免疫荧光Ｔ细胞亚群标记技术，研究全波段紫外线（ＵＶ）照射人体外周血对Ｔ细胞亚群计数的影响。ＵＶ照射使ＣＤ和ｃｄ细胞显著减少，其作用在一定程度上与剂量有关；ＣＤ４／ＣＤ８比值也显著降低，ＣＤ细胞在ＵＶ照射后有所增加，但无统计学意义．结果表明，ＵＶ照射能选择性地作用于人Ｔ细胞不同亚群，提示ＵＶ照射可能影响Ｔ细胞不同亚群的功能，从而调控机体的免疫功能．     

低剂量γ射线全身照射对猴免疫功能的影响

目的　探索大动物低剂量全身照射的适宜剂量 ,以便评价低剂量全身照射应用于临床的可能性。方法　食蟹猴 32只随机分为 4组 ,用γ射线 (吸收剂量率为 0 175mGy min)分别照射0、30、5 0和 75mGy。分别在环磷酰胺处理前、后 ,亦即照射前和照射后 1、2、8、33和 5 0周检测淋巴细胞亚群、免疫球蛋白及自然肿瘤红细胞花环试验 (NTERT)。结果　结果显示白细胞释放细胞因子尤其是CD1 6 参与免疫调控 ,出现时间 剂量的反应 ;体液免疫中以IgA升高为特征 ,照射后第 8周 5 0和75mGy 2个剂量组与对照组相比差异有显著性 (P <0 0 5 ) ;NTERT结果显示 ,在照射后第 2周 ,第 1、2、3组分别与第 4组相比差异有显著性 (P <0 0 5 ) ,但第 1组分别与第 2、3组相比差异无显著性。结论　γ射线单次低剂量全身照射对免疫功能低下模型的食蟹猴红、白细胞免疫功能有增强其免疫功能的作用。     

头部X线照射后大鼠血清中皮质酮含量和脾细胞中糖皮质激素受体变化及其相互关系的研究

给Wistar大鼠以10Gy X射线头部照射后不同时间测定血清皮质酮含量和脾细胞中糖皮质激素受体,结果表明:头照后24h受体数已降到对照组的25％,以后逐渐回升,至第9天恢复到接近正常水平。头照后受体的最大结合容量有降低趋势,但差异不显著,而Kd值显著增大,亲和力降低。皮质酮含量的变化呈双峰曲线,第1天即显著增高,至第9天仍显著增高,皮质酮含量和受体的变化规律不一致。体外实验还证实了1～10倍血清浓度的皮质酮在短时间内不会引起所测定的GCR改变。证明皮质酮的变化虽然可能是引起受体变化的一个原因,但不是主要原因。     

Detection of refrigerator-associated 60 Hz alternating current as ventricular fibrillation by an implantable defibrillator.

This report describes a patient with an implantable defibrillator who suffered an inappropriate defibrillation shock upon retrieving some food items from his inadequately earthed refrigerator. Noise typical of electrical interference can be observed in the stored electrogram of the episode. The patient was instructed to earth his home appliances, but he decided to avoid his refrigerator altogether, and has had no subsequent shocks.     

X线辐射体外诱发大鼠肺成纤维细胞恶性转化

本文报告了X线辐射0.5、1.0、3.0及5.0Gy体外诱发WAL-F_1细胞系恶性转化的剂量-效应关系及其细胞生物学特征.细胞转化率(y,%)与剂量(D,Gy)有关,可用下式表达:?3.0Gy照射时转化率最高,为0.41×10~(-1)%.转化细胞生物学特性明显不同于对照细胞,(1)呈上皮样细胞形态;(2)具有持续增殖能力,没有衰老现象,复层生长;(3)染色体核型异常,出现异倍体或多倍体;(4)Con A凝集试验阳性;(5)在半固体琼脂培养基中形成集落;(6)接种于同种动物体内诱发肿瘤.本研究为肿瘤病因学、发病机理及防治研究提供一个良好的实验模型.     

血液辐射前后SOD、GSH－PX及LPO含量的变化

观察２０例心脏病患者血液辐射前后红细胞ＳＯＤ、全血ＧＳＨ－ＰＸ及血浆ＬＰＯ变化，并计算ＳＯＤ／ＬＰＯ比值，结果表明：血液辐射前后ＧＳＨ－ＰＸ、ＬＰＯ及ＳＯＤ／ＬＰＯ无明显改变，但辐射后ＳＯＤ活性明显升高，提示自血辐射疗法的作用机制可能部分是通过激活ＳＯＤ活性，抑制超氧阴离子产生，减少脂质过氢化损伤发挥治疗作用。     

β和γ射线照射肿瘤细胞的生物效应比较

目的 比较低剂量率β射线和高剂量率γ射线照射诱发肿瘤细胞生物效应特点。方法采用^32Pβ射线和^60Coγ射线照射人宫颈癌HeLa细胞系，用台盼蓝排除法和X-gal衰老细胞染色法比较两种照射肿瘤细胞死亡方式的差异。结果 ^32Pβ射线(0．375cGy/min)和^60Coγ射线(206cGy/min)照射HeLa细胞后72h的结果表明，低剂量率β射线抑制细胞增殖为渐进性，使多数的细胞在一个或几个细胞倍增周期后死亡，以增殖性死亡为主；高剂量率γ射线对细胞的抑制作用直接、迅速，细胞坏死比例高，增殖性死亡(衰老)比例低于持续低剂量照射方式。结论 不同的辐射方式对细胞的杀伤方式不同，了解其放射生物学机理有助于临床治疗方案的选择。     

Impact of Increasing Margin Around the Lumpectomy Cavity to Define the Planning Target Volume for 3D Conformal External Beam Accelerated Partial Breast Irradiation

The purpose of this study was to evaluate the dose to normal tissues as a function of increasing margins around the lumpectomy cavity in accelerated partial breast irradiation (APBI) using 3D-conformal radiotherapy (3DCRT). Eight patients with Stage 0-I breast cancer underwent treatment planning for 3DCRT APBI. The clinical target volume (CTV) was defined as a 15-mm expansion around the cavity limited by the chest wall and skin. Three planning target volumes (PTV1, PTV2, PTV3) were generated for each patient using a 0, 5-, and 10-mm expansion around the CTV, for a total margin of 15, 20, and 25 mm. Three treatment plans were generated for every patient using the 3 PTVs, and dose-volume analysis was performed for each plan. For each 5-mm increase in margin, the mean PTV:total breast volume ratio increased 10% and the relative increase in the mean ipsilateral breast dose was 15%. The mean volume of ipsilateral breast tissue receiving 75%, 50%, and 25% of the prescribed dose increased 6% to 7% for every 5 mm increase in PTV margin. Compared to lesions located in the upper outer quadrant, plans for medially located tumors revealed higher mean ipsilateral breast doses and 20% to 22% more ipsilateral breast tissue encompassed by the 25% IDL. The use of 3DCRT for APBI delivers higher doses to normal breast tissue as the PTV increases around the lumpectomy cavity. Efforts should be made to minimize the overall PTV when this technique is used. Ongoing studies will be necessary to determine the clinical relevance of these findings.