Development and characterisation of a head calibration phantom for in vivo measurements of actinides.

The investigation of actinides' internal contamination in human body makes use of a variety of techniques. In large scale screening the technique of "in vivo" evaluation of bone 241Am burden via the determination of the nuclide activity in the skull is often used. For this purpose, adequate calibration procedures and standard phantoms are needed. The present paper summarises the studies and technical procedures followed for the development of a calibration phantom based on a commercial Alderson angiographic head in which a set of 24 241Am point sources were embedded. A theoretical study was first carried out, at the ENEA Institute for Radiation Protection, using the MCNP4-B Monte Carlo code to determine the point source distribution that closely approximates a homogeneous bone contamination. The numerical models were also used to evaluate the resulting degree of approximation. The point sources were prepared at the ENEA National Metrology Institute for ionising radiation quantities and were traceable to the Italian national standard of radionuclide activity. The sources were prepared by quantitatively dispensing a liquid solution onto a plastic disc. The activity of each source was checked by gamma-ray spectrometry and the reproducibility of the activity values was determined. Each source was then placed in the optimum position in the skull, given by the Monte Carlo modelling, by a precision mechanical device. The phantom was finally used to calibrate a whole body counter operating at the ENEA Institute for Radiation Protection. The paper reports the main theoretical and experimental aspects of this work, and also discusses the results of the first calibrations.     

外源核苷酸对免疫抑制小鼠胸腺细胞DNA损伤的影响

目的:检测外源核苷酸对经环磷酰胺诱导的免疫抑制小鼠胸腺细胞DNA损伤的影响。方法:采用18～20 g昆明种小鼠30只,雌雄各半,随机分成阴性对照组(NEC)、阳性对照组(POC)和核苷酸组(NTG),每组10只。NEC组和POC组小鼠均饲喂半纯合无核苷酸的基础日粮,NTG组则在基础日粮中添加0.25%的核苷酸,实验期为21 d。在实验结束前18 h POC组和NTG组小鼠按照150mg/kg bw的剂量腹腔注射环磷酰胺,NEC组注射生理盐水,实验结束时测定脾脏和胸腺脏器指数,并取胸腺细胞,做单细胞凝胶电泳,观察细胞DNA损伤情况。结果:在基础日粮中添加核苷酸对小鼠免疫器官重量没有显著影响(P>0.05),但能极显著降低受损胸腺细胞百分率(P<0.01)和受损细胞DNA尾长(P<0.01)。结论:外源核苷酸能显著降低免疫抑制小鼠受损胸腺细胞百分率和损伤程度。     

自我效能感与晕船症状的相关研究

目的探讨自我效能感与晕船症状的相关,以期寻找影响晕船的心理因素.方法对某院校参加海上实习的123名医疗本科学员用一般自我效能感量表、晕船自我效能感量表于出海作业前进行施测,用晕船症状评分量表于出海作业返回后进行评估.结果晕船自我效能感与晕船症状显著负相关(r=-0.470,P＜0.01),而一般自我效能感量表与晕船症状的相关无统计学意义(r=-0.102,P＞0.05).结论晕船自我效能感可能为个体发生晕船的心理影响因素之一.     

Prognostic significance of tumor necrosis in ovarian cancer patients treated with neoadjuvant chemotherapy and interval surgical debulking

The objective of this study was to study the significance of tumor necrosis documented at the time of interval surgical debulking after neoadjuvant chemotherapy. Retrospective chart reviews were carried out from 1997 to 2005 to identify ovarian cancer patients treated with neoadjuvant chemotherapy. Patients' demographics together with disease characteristics, treatment-related variables, and outcomes were recorded. Cox proportional hazard models were built to model time to progression using predictor variables such as age, cancer stage, tumor grade, residual disease, percentage change in CA125 level from baseline, and degree of necrosis in resected tumor specimens. One hundred one patients were included in the study. Optimal debulking was achieved in 74% of the patients. Cox regressions revealed three significant predictive variables of time to first progression: younger age (hazard ratio [HR] = 0.95, 95% CI 0.92-0.98, P= 0.004), residual disease (P= 0.048), and the absence/minimal tumor necrosis after three cycles of neoadjuvant chemotherapy (HR = 1.97, 95% CI 1.01-3.87, P= 0.048). The estimated median survival was 50.66 months (95% CI 46.12-55.20). The lack of or minimal tumor necrosis after neoadjuvant chemotherapy is an independent risk factor for recurrent disease.     

The treatment of post-traumatic stiffness of the elbow

The authors present the results observed in 12 patients affected with post-traumatic stiffness of the elbow treated by an external fixator in distraction to obtain functional recovery of range of movement; in all of the cases anterior and posterior release and resection of the apex of the olecranon was carried out, while in 2 cases interposition arthroplasty with freeze-dried dura madre was associated. The series includes 12 cases with a long-term follow-up that ranges from 8 to 33 months after surgery. The mean arch of movement during the preoperative phase was 35 degrees (minimum 0 degree-maximum 90 degrees) in flexion extension and 80 degrees (minimum 0 degree-maximum 150 degrees) in pronosupination. Recovery of mean joint excursion in flexion-extension was 91 degrees and in pronosupination it was 127 degrees. Complications included loosening of the nails in 2 cases, breakage of the nails in 1 case, and transitory deficit of the ulnar nerve in 4 cases. A total of 11 patients (91.66%) declared that they were satisfied with the considerable improvement in their ability to do daily activities. The results of arthroplasty in distraction in the elbow are satisfactory even if much attention must be paid to the selection of the patients because of the intense collaboration that is required during postoperative rehabilitation.     

Assessment of chitosan derivatives as buccal and vaginal penetration enhancers.

The aim of the present work was to evaluate the mucoadhesive and penetration enhancement properties via the buccal and vaginal mucosae of four different chitosan derivatives: 5-methyl-pyrrolidinone chitosan (MPC), two low molecular weight chitosans (DC1 and DC2) and a partially reacetylated chitosan (RC). Chitosan HCl was used as a reference. Polymer solutions (4% w/w) were prepared in media simulating the buccal (pH 6.4 buffer or water) and the vaginal (pH 5.0 buffer) environments and subjected to rheological characterization. Acyclovir was added to the polymer solutions at 5% (w/w) concentration. The mucoadhesive properties of the polymer solutions were measured using excised porcine cheek or vaginal mucosa and mucin dispersions to simulate the buccal or vaginal environments, respectively. Drug permeation and penetration tests were carried out using porcine cheek and vaginal mucosae as model membranes. Acyclovir aqueous suspensions prepared in pH 6.4 and 5.0 buffers were used as blanks. Drug release measurements were also carried out in the same conditions employed for the permeation and penetration tests. Methyl-pyrrolidinone chitosan shows the best mucoadhesive and penetration enhancement properties in both buccal and vaginal environments. The capability to enhance the permeation/penetration of acyclovir was decreased by partial depolymerization of chitosan and disappeared after partial reacetylation.     

卡介菌多糖核酸辅助治疗对结核病患者血清可溶性白细胞介素2受体的影响

目的 观察结核病治疗的强化期联用卡介菌多糖核酸(BCG-PSN)(商品名:斯奇康)对患者血清可溶性白细胞介素2受体(sIL-2R)的影响.方法 将53例初治结核病患者随机分为观察组和对照组,在采用标准短程化疗方案(2HRZE/4HRE)的基础上,观察组在强化期加用臀部肌肉注射BCG-PSN,两组分别在治疗前后检查血清sIL-2R浓度.结果 两组治疗后血清sIL-2R均有明显降低,其中观察组已降至正常水平,与对照组相比有显著差异.结论 结核病治疗的强化期联用BCG-PSN能显著降低血清sIL-2R,提高结核病患者细胞免疫功能.     

113例原发性肝癌的临床病理分析

目的:探讨原发性肝癌临床及病理学特征。方法:对113例原发性肝癌的临床资料和病理资料进行回顾性分析。结果:113例原发性肝癌有91例为肝细胞癌,22例为胆管癌。91例肝细胞癌患者均为乙肝患者,其中86例伴发结节性肝硬化,87例AFP阳性;组织学类型小梁型56例,假腺型15例,实体型20例。22例胆管癌患者仅1例有乙肝病史,3例合并肝血吸虫病,5例合并胆管炎症或结石。结论:肝细胞癌与乙肝病毒感染密切相关,常见于结节性肝硬化患者,大部分患者AFP阳性,组织学类型以小梁型为主。胆管癌多见于女性,通常无肝硬化,与血吸虫感染或胆管炎症有较密切关系。     

四种粘结材料对纤维桩在不同深度根管内的固位力的影响——薄片推出实验

目的:比较4种不同树脂粘结材料在不同深度根管内粘固纤维桩的推出强度。方法:28个单根管离体前牙截冠后行根管充填和桩道预备,随机分为4组,分别用不同的粘结材料(Ⅰ:XP Bond-Dual Cure Calibra resincement;Ⅱ:XP Bond-Dual Cure Fluorocore2;Ⅲ:Excite DSC MultiCore Flow;Ⅳ:Multilink Primer A/B MultilinkAutomix)粘固纤维桩。粘固了纤维桩的牙根切割为1mm厚的试件并将其按照根管的深度分为上部、中部和下部3组,测试其推出强度。结果:Ⅰ组、Ⅱ组上部的推出强度均显著高于下部(P<0.05),Ⅲ组、Ⅳ组的推出强度在不同深度根管间无显著性差异(P>0.05)。结论:材料的类型和根管的深度对纤维桩的固位有影响。