The bactericidal activity of pulsed Nd-YAG laser radiation in vitro

Pulsed Nd-YAG laser irradiation of bacteria has been suggested as a possible means of treating contaminated intra-oral sites although relatively few studies have been conducted. In this investigation, the antimicrobial activity of a pulsed Nd-YAG laser was assessed in vitro for a range of oral bacteria using several pulse energies and exposure durations. Pure cultures of each organism were lased in saline suspensions followed by standard colony counting techniques for test and control samples. Microbial inhibition was found to be organism-dependent and varied with energy dose and pulse energy. For all nine test species 120-mJ laser pulses proved more efficient than 80-mJ pulses, with 99.9% kills compared with around 90% kills after exposure to 1800 pulses. These killing activity levels compare favourably with those achieved with other lasers in vitro.     

Oxygenated and reoxygenated tumors show better local control in radiation therapy for cervical cancer

The presence of hypoxic cells is one of the major factors affecting resistance against radiation therapy. In the clinical setting, little information exists as to the relationship between intratumoral oxygen partial pressure (pO(2)) and outcome. This study involved 30 consecutive patients with cervical cancer, who were treated with a combination of external and high-dose rate intracavitary irradiation. The pO(2) was measured before radiation therapy and at 9 Gy, using a needle-type polarographic oxygen electrode. The mean intratumoral pO(2) before radiation therapy was 17.3 +/- 10.8 mm Hg. The 3-year local control rates of patients with pO(2)< or = 20 mm Hg and pO(2) > 20 mm Hg before radiation therapy were 52% and 100%, respectively, representing a significant difference (P= 0.035). At 9 Gy, mean intratumoral pO(2) was 23.6 +/- 9.1 mm Hg, a significant increase compared to the value before radiation therapy (P= 0.006). The 3-year local control rates of tumors with pO(2)< or = 20 mm Hg and pO(2) > 20 mm Hg at 9 Gy were 35% and 93%, respectively, representing a significant difference (P= 0.001). The significantly better local control for oxygenated tumors at 9 Gy as well as before radiation therapy indicated that the oxygen effect and reoxygenation by radiation played an important role in local control in radiation therapy for cervical cancer.     

常规染色体畸变分析法对AT细胞高辐射敏感性的研究

目的 研究毛细血管扩张性共济失调症(ataxia-telangiectasia,AT)患者皮肤的成纤维细胞系AT5BIVA(AT细胞)的高辐射敏感性。方法 以源于正常人皮肤的成纤维细胞系GM0639(GM细胞)为对照,用常规染色体畸变分析法,在AT细胞和GM细咆经60COγ射线0、1、2、3、4 Gy照射后,观察比较AT细胞和GM细胞之间染色体畸变率(CAF)的差异,并分别进行曲线拟合。结果 在0、1、2、3、4 Gy剂量下,AT细胞染色体畸变率明显高于GM细胞(P<0.05);AT和GM细胞染色体畸变率与剂量成正相关,均可拟合成剂量效应直线方程Y=a+bX,且AT细胞剂量效应直线回归方程斜率明显大于GM细胞(P<0.05)。结论 AT患者AT细胞的辐射敏感性显著高于GM细胞,具有高辐射敏感性。     

Late side-effects with cosmetic relevance following soft X-ray therapy of cutaneous neoplasias

Background Cosmetic changes are to be expected after radiotherapy for skin tumours. Objectives This study aimed to answer the questions: How frequent are cosmetic changes after soft X‐ray therapy? Do treatment parameters, tumour thickness, localization and size of the irradiated field have a major influence? Were patients irritated by the visual appearance of the irradiated field? Methods In total, 2474 examinations of 1149 irradiated fields were performed. Results Hypopigmentation was found in 64.7% of examinations more than 90 days after therapy, teleangiectases in 43.1%, erythema in 24.8%, and hyperpigmentation in 16.8%. The frequency of hypopigmentation, teleangiectases and hyperpigmentation increased with time from X‐ray exposure; more than 4 years after therapy hypopigmentation was diagnosed in 91.8% and teleangiectases in 82.2% of examinations. Total dose, the time–dose–fractionation factor (TDF), field size and dose per fraction were significantly related to the frequency of cosmetic changes. Incidence rates of cosmetic changes differed by less than 15% if different treatment conditions were compared: thicker vs. thinner tumours, larger vs. smaller fields, higher vs. lower total doses, doses per fraction, and TDF. Frequencies of hypopigmentation, teleangiectases, erythema and hyperpigmentation differed by more than 15% between some localizations on the head. Women reported irritation by the visual appearance of the irradiated field in 12.6% of 1116 interviews, and men in 4.4% of 1284 interviews. Conclusions Cosmetic changes after soft X‐ray therapy are relatively frequent. Treatment parameters, tumour thickness and field size have only a minor influence. Few patients, but more women than men, were irritated by the visual appearance of the irradiated field.     

局部进展期胰腺癌调强放疗剂量递增临床研究

目的探索调强放射治疗 (IMRT)提高进展期胰腺癌局部肿瘤靶区剂量以及减少周围正常组织照射剂量的可能性。　方法 2 1例局部进展期胰腺癌患者接受同期放化疗。放射治疗分第一阶段予常规放射治疗 ,剂量30Gy/ 15次 / 3周 ;第二阶段强调放射治疗 ,肿瘤靶区分割剂量 3Gy/次 ,总剂量为 2 1～30Gy ,在 2周内分 7～10次完成。总剂量递增水平 :5 1、5 4、5 7、6 0Gy。在放射治疗过程中 ,每个治疗日 5 -FU静脉点滴。　结果 16例完成治疗计划 ,分别为 5 1Gy 3例、5 4Gy 3例、5 7Gy 3例 ,6 0Gy 7例。 13例治疗前CA19- 9值升高 ,中位值治疗前后分别为 716、2 5 5U/ml(P <0 .0 0 1)。 14例以疼痛为主的患者至少减少 1/ 3～1/ 2的麻醉药品用量 ,其中 5例疼痛症状完全消失。10例患者治疗后卡氏评分有提高。　结论局部进展期胰腺癌患者接受适形调强放疗并同期应用 5 -Fu化疗增敏 ,可获得确切的姑息治疗作用 ,肿瘤剂量 6 0Gy分 2 5次在 5周完成 ,无严重的放射治疗相关的急性毒性反应     

乌克兰四零八军区医院抢救切尔诺贝利核电站事故伤员的经验

切尔诺贝利核电站事故发生后,先后有30万左右的军人参加事故救援.本文介绍了乌克兰四零八军区医院对切尔诺贝利核电站事故伤员救治工作的任务.介绍了医疗救援三个阶段的时间划分、任务重点、兵力的投入及其结构组成.介绍了医院内部专门科室的建立、对受照剂量为0.25～0.50Gy的594例伤员健康状况的分析,其血液学改变的发生率随受照剂量增加而增多.介绍了参与救治工作医师们研究的主要内容,强调要考虑小剂量辐射对心血管系统和胃肠道的远期效应.根据救治工作的经验,分析了救治过程中存在的问题.     

Clinical Course and Autopsy Findings of a Patient with Clival Chordoma Who Underwent Multiple Surgeries and Radiation during a 10-Year Period.

The management of clival chordoma remains problematic. We present the case of a 48-year-old woman with clival chordoma who underwent multiple surgeries and radiation therapy, including gamma knife stereotactic radiosurgery (GK-SRS), during a 10-year clinical course. The tumor was initially removed by gross total resection via the trans-sphenoidal approach, followed by external linac radiation therapy. The tumor recurred at the clivus 5 years after the initial operation. After repeated trans-sphenoidal removal of recurrent tumors, she twice underwent GK-SRS for a tumor remnant adjacent to the brainstem. Although this part of the tumor was controlled by GK-SRS, there was further tumor extension toward the sphenoid and maxillary sinuses. Ultimately, lower cranial nerve dysfunction developed due to tumor extension into the lower part of the clivus and the patient died of respiratory failure. Autopsy revealed the tumor to extend from the lower clivus to the bilateral middle fossae. The lower part of the tumor extended to the nasal cavity and to the posterior wall of the pharynx, resulting in compression of the upper pharyngeal region. The tumor around the jugular foramen compressed the lower cranial nerves bilaterally. Tumor cells did not, however, invade the intradural space microscopically. Although chordoma is not biologically malignant, this tumor can show massive extension with destruction of bony structures and extracranial invasion of connective tissues. Therefore, the optimal treatment strategy is to remove the tumor mass as extensively as possible, including normal bony structures and connective tissues surrounding the tumor, using skull base surgical techniques.     

极重度骨髓型和肠型急性放射病细菌感染的防治

目的 探讨极重度骨髓型和肠型急性放射病细菌感染的防治经验,为今后急性放射病的治疗提供治疗经验.方法 2例急性放射病患者整个病程中均合并不同菌种的感染,通过观察患者的临床症状、影像学检查及相关的病原体检测而给予不同强度的抗细菌和真菌治疗,通过观察临床症状、影像学检查及病原学检测评价疗效.结果 2例急性放射病患者在治疗中均出现多次反复的细菌感染,同时伴有持续的真菌感染,经强有力的抗细菌和真菌治疗后细菌感染得到暂时控制,真菌感染始终没有控制.病例A于受照后14天出现急性腹膜炎,照后19天出现肺部感染,经泰能加万古霉素等抗生素治疗细菌感染得到控制,于照后33天死于真菌感染败血症和多脏器功能衰竭.病例B于受照后反复出现肺部感染,且于照后55天和照后71天出现G-杆菌败血症,经泰能加万古霉素等抗生素治疗后细菌感染均控制,但真菌感染一直存在,于照后75天因多脏器功能衰竭抢救无效死亡.结论 极重度骨髓型和肠型急性放射病患者的细菌感染呈阶段性.全身性阶段性应用高强抗生素是防治细菌感染的主要有效措施.     

乌克兰居民在切尔诺贝利核电站事故后的健康状况

本文报告了切尔诺贝利事故后受到影响的乌克兰三个人群(救援人员、30km区域内撤离人员、儿童和少年)在1990～2004年间健康状况的观察结果.受害者的总人数有22.5万人.受照剂量在0.25～0.70Gy的救援人员有7 400人.观察的指标有随机性效应(甲状腺癌、白血病、妇女乳腺癌和其他恶性肿瘤的发病率)和确定性效应(急性放射病、白内障、非肿瘤性疾病,以及儿童和少年的健康状况),证明上述人群中这些效应的危险性有所增加.报告还分析了非照射因素在这些效应发生中所起的作用,说明这些疾病在发病原因上的多样性.