Cell Tracking Using Nanoparticles

Tracking cells in regenerative medicine is becoming increasingly important for basic cell therapy science, for cell delivery optimization and for accurate biodistribution studies. This report describes nanoparticles that utilize stable-isotope metal labels for multiple detection technologies in preclinical studies. Cells labeled with nanoparticles can be imaged by electron microscopy, fluorescence, and magnetic resonance. The nanoparticle-labeled cells can be quantified by neutron activation, thereby allowing, with the use of standard curves, the determination of the number of labeled cells in tissue samples from in vivo sources. This report describes the characteristics of these nanoparticles and methods for using these nanoparticles to label and track cells. Suggested reviewers: Timothy Henry, Anthony DeMaria, Bernard Gersh     

X-ray fluorescence analysis of bromine for the estimation of extracellular water

Three methods for extracellular water (ECW) estimation via analysis of the corrected bromine space (CBS) are presented. The methods are based on the application of stable bromine as an indicator and X-ray fluorescence analysis (XRF). The content of stable bromine can be determined in samples of ulna vein blood and daily urine (the first method) as well as in microsamples of finger blood (the second method) and mixed non-stimulated saliva (the third method). The precision and accuracy of the methods were compared using the results of both repeated analysis and CBS estimation by different procedures including the routine method with ⁸²Br as indicator. A device for XRF with a Si(Li) detector and ¹⁰⁹Cd sources was developed for bromine determination in biological fluids.     

造血因子治疗中子急性放射病的实验研究

目的通过观察造血生长因子-重组人白细胞介素-11(rhIL-11)和重组人粒细胞集落刺激因子(rhG-CSF)联合应用的方法对中子急性放射病狗的治疗效果,探讨中子损伤治疗的救治方法。方法14只雄性成年比格狗随机分为照射对照和rhIL-11+rhG-CSF治疗组。所有动物均接受90%裂变中子照射,治疗组于照后当天开始每天1次皮下注射rhG-CSF10μg·kg-1·d-1和rhIL-1150μg·kg-1·d-1,给药时间分别为14和21d。照射后观察动物的外周血象、外周血CD4+/CD8+比值变化、骨髓CFU-E及组织病理学改变。结果照射后早期对照组动物全部发生不同程度的呕吐,治疗组仅1只动物呕吐。照射后30d照射对照组死亡3只,治疗组动物全部存活。照后治疗组外周血白细胞数和恢复期血小板数明显高于照射对照组。照射后1、21和33d治疗组外周血CD4+/CD8+比值分别为照射对照组1·24、1·55和2·15倍。照射后1和33d治疗组动物骨髓CFU-E分别为照射对照组的5·25和2·34倍(P<0·01)。结论rhIL-11+rhG-CSF联合给药可明显促进中子照射所致骨髓型急性放射病狗的造血和免疫功能恢复,为细胞因子应用于中子急性放射病的临床治疗提供了实验依据。     

Advanced γ ray technology for scanning cargo containers

The shipping industry is striving to increase security for cargo containers without significantly impeding traffic. Three Science Applications International Corporation (SAIC) development programs are supporting this effort. SAIC's ICIS system combines SAIC's VACIS^® γ ray imaging, radiation scanning, OCR, elemental analysis and other technologies to scan containers for nuclear materials and other hazards in normal terminal traffic. SAIC's enhanced γ ray detector improves VACIS image resolution by a factor of three. And SAIC's EmptyView software analyzes VACIS images to automatically verify empty containers.     

15MV医用直线加速器光中子蒙特卡罗模拟

目的 研究高能医用直线加速器运行过程中因光核反应所形成的光中子辐射场。方法 利用蒙特卡罗(MC)程序模拟Clinic 2300CD型医用电子加速器15 MV X射线模式下光中子污染,掌握机头内不同位置光中子能谱和不同照射野下等中心处中子周围剂量当量变化,分析光中子在等中心平面内剂量分布和水模体中剂量衰减。结果 准直器关闭时,加速器机头内靶、主准直器、均整器和多叶准直器下表面的光中子平均能量分别为1.08、1.20、0.35、0.30MeV;等中心处中子周围剂量当量随着照射野的增大先增大后减少,在30 cm × 30 cm照射野下达到最大;随着测点在水模体中的深度增加,中子通量先增加后减小,而中子剂量却在逐渐减小;不同照射野下,光中子剂量率在水模体深度20 cm处,基本都接近本底。结论 探究高能医用直线加速器机头光中子谱和剂量分布特点,以及光中子在水模体内剂量沉积规律,能为进一步研究高能医用直线加速器光中子污染对患者产生的附加剂量提供支持。     

Long-term measurement of skeletal and lean body mass in Paget's disease of bone treated with synthetic human calcitonin

Summary Total body calcium (an index of skeletal mass), ulnar bone density, and total body potassium (lean body mass) were followed for up to 5 years in 38 patients with Paget's disease during treatment with synthetic human calcitonin. Calcium was measured by neutron activation, ulnar density by X-ray photodensitometry, and potassium by counting its natural⁴⁰K radioactivity. There was a significant rise in total skeletal mass in a group of 8 patients in the 12 months following the start of therapy, but overall, total bone mass and ulnar density remained constant during treatment. Small mean losses of body potassium were observed (∼4%) after several years elapsed on treatment. Over an average period of 12 months after discontinuation of therapy in 21 patients there was no significant mean change in calcium or potassium. The means of the ratios of total body calcium divided by predicted normal calcium (over the whole period of measurement) were 1.08 (males) and 0.99 (females) and were not significantly different. Comparison of the ulnar densities of patients and normal subjects gave similar results. The average ratio of measured to predicted normal potassium was 1.13 (both males and females). Thus there was no indication of depletion in skeletal mass below normal either in the untreated disease or resulting from treatment.     

A preliminary report on the clinical application of fast neutrons in Krakow

The neutron therapy facility based on the cyclotron installed in the Institute of Nuclear Physics in Kraków, Poland, is described. Fast neutrons are produced by bombarding a beryllium target with 12.5 MeV deuterons. The unit has been used for treatment of cancer patients by the medical team of the Institute of Oncology in Kraków since September, 1978. Fifty-three patients were treated; most of these patients had advanced head and neck cancer. On the basis of the radiobiological experiments, a standard tumor dose of 1320 rad_n,gamma in 20 fractions over 4 weeks was established. From among 34 patients with advanced head and neck cancer, treated with neutrons only, and observed for at least one year, 10 patients, (29%) are living free of cancer.     

Late reactions and complications in patients treated with high energy neutrons p (66MeV)Be(49MeV)

Eight of 22 patients who were followed for a year or more after neutron doses in excess of 20 Gy slowed significant late reactions. Late reactions were also observed in 6 of 20 patients who were treated with a neutron boost of 7.5 Gy following 50 Gy of photons for intraoral cancer, and in 5 of 9 ‘mixed beam’ patients who received 9 to 11 neutron Gy with 45 to 50 photon Gy concurrently over a seven week treatment period. Nine of 20 patients who were treated with curative doses of neutrons following recurrence after radical photon therapy had excessively severe late effects. In the neutron only group, a tentative isoeffect line (dose versus fractions) for cutaneous fibrosis could be drawn with an origin at 20 Gy and a slope of 0.04. A time-dose factors analysis of the whole series suggested that a TDF of 120 (±10) defined the threshold for severe stromal fibrosis and associated complications.