In vivo MRI of cancer cell fate at the single-cell level in a mouse model of breast cancer metastasis to the brain.

Metastasis (the spread of cancer from a primary tumor to secondary organs) is responsible for most cancer deaths. The ability to follow the fate of a population of tumor cells over time in an experimental animal would provide a powerful new way to monitor the metastatic process. Here we describe a magnetic resonance imaging (MRI) technique that permits the tracking of breast cancer cells in a mouse model of brain metastasis at the single-cell level. Cancer cells that were injected into the left ventricle of the mouse heart and then delivered to the brain were detectable on MR images. This allowed the visualization of the initial delivery and distribution of cells, as well as the growth of tumors from a subset of these cells within the whole intact brain volume. The ability to follow the metastatic process from the single-cell stage through metastatic growth, and to quantify and monitor the presence of solitary undivided cells will facilitate progress in understanding the mechanisms of brain metastasis and tumor dormancy, and the development of therapeutics to treat this disease.     

A Neuromagnetic Study of the Functional Organization of the Sensorimotor Cortex

Movement-related neuromagnetic fields from eight healthy human subjects were investigated in a Bereitschaftspotential paradigm. The three conditions studied were right-sided mouth, index finger and foot movement. The neuromagnetic field patterns corresponding to the motor field and the movement-evoked field I were analysed using a moving dipole model. For both components a somatotopic organization was found: the estimated dipole locations for the mouth were more lateral and those for the foot more medial than the estimated dipole positions for the index finger movement. With regard to possible clinical applications, e.g. non-invasive mapping of the sensorimotor cortex and studies of plasticity of the motor function, the present results suggest that the investigation of movement-evoked field I for the index finger condition is most likely to yield further results.     

Propriospinal myoclonus: utility of magnetic resonance diffusion tensor imaging and fiber tracking.

Propriospinal myoclonus (PSM) is a rare movement disorder characterized by involuntary spinal-generated muscular jerks that spread rostrally and caudally to other spinally innervated muscles. Most patients have no clear etiology, and conventional MRI of the spinal cord is generally normal. Here we report the use of magnetic resonance diffusion tensor imaging (DTI) and fiber tracking to detect tract-specific abnormalities in a patient with propriospinal myoclonus. As the patient had the fragile-X premutation and antithyroid antibodies, spinal cord DTI abnormalities may be related to these conditions. Tract-specific analysis may provide new insights into the pathophysiology of propriospinal myoclonus.     

关于引进双源CT的可行性分析

本文就双源CT的市场需求、特点和用途进行了详细分析,为医院引进双源CT提供参考。     

《内经》俞、输、腧探源

《素问》用“俞”，《灵枢》用“输”与“腧”表示腧穴，三字用法基本相同。“俞”源于用船运送，“输”源于用车运送，均引申为转运气血的穴位。“腧”是“俞”的今字，其字形代表的意义最符合中医学中腧穴的含义。应以“腧”作为规范的词语，表示腧穴的各种意义。     

一例~(192)Ir极不均匀外照射局部极重度放射损伤的临床观察

目的对１例１９２Ｉｒ极不均匀外照射局部极重度放射损伤病人进行临床观察。方法系统观察了病变的临床过程和应用红外线热成像技术测定了损伤部位的温度变化。结果照射后２小时出现肢体麻木、抽搐，最早照后４小时出现红斑、肿胀，５４小时出现水疱，第５天出现坏死和剧痛，最晚出现红斑、肿胀是照射后４１天，４７天出现水疱和糜烂创面。红外线热成像显示：损伤早期温度升高，水疱、坏死区和损伤后期温度降低，温度升高越早，损伤越重，温度改变区域与损伤范围相一致。结论大剂量极不均匀外照射放射损伤的初期反应早，放射病与局部损伤相互加重病情，症状先后不一，轻重不等，致残率高和疼痛剧烈，红外线热成像温度变化可以作为临床诊断的指标之一。     

A slim needle-shaped multiwire microelectrode for intracerebral recording

The construction of a needle-shaped multiwire microelectrode is described. It can be made with simple mechanical tools. The presented electrode assembly consists of 12 insulated nichrome wires (core diameter 25 μm) which are embedded in epoxylite resin. The straight-cut wire tips are aligned lengthwise and have a relative spacing of 150 μm. Outer dimensions vary from 100 × 180 μm at the level of the 1st electrode channel, to 100 × 100 μm at the level of the 12th channel at the tip. The configuration of this electrode was determined by its application: the laminar analysis of evoked potentials in the cortex of the rat. However, the number of channels, the diameter of the (nichrome) wire which determines the surface area of these channels, and the channel spacing can be easily adjusted during construction to meet other experimental requirements, such as the recording of single-unit activity. The electrode which is composed of biocompatible materials is suited for the study of field potentials and multiple-unit activity, in both acute and chronic experiments, and can be used repeatedly. To demonstrate the performance of the electrode assembly, a depth profile of field potentials is presented, accompanied by the corresponding current source density distribution. The potentials were recorded in the somatosensory cortex of the rat following stimulation of the median nerve under ketamine anesthesia.     

Cerebral perfusion assessment by bolus tracking using hyperpolarized 13C.

Cerebral perfusion was assessed with 13C MRI in a rat model after intravenous injections of the 13C-labeled compound bis-1,1-(hydroxymethyl)-1-13C-cyclopropane-D8 in aqueous solutions hyperpolarized by dynamic nuclear polarization (DNP). Since the tracer acted as a direct signal source, several of the problems associated with techniques based on traditional dynamic susceptibility contrast (DSC) MRI contrast agents were avoided. Maps of cerebral blood flow (CBF), cerebral blood volume (CBV), and mean transit time (MTT) were calculated. The MTT was determined to be 2.8 +/- 0.8 sec. However, arterial partial-volume effects in the animal model prevented accurate absolute quantification of CBF and CBV. It was demonstrated that depolarization of the hyperpolarized 13C tracer via relaxation and the imaging sequence had little influence on CBF assessment when the time resolution of the imaging sequence was short compared to the MTT. However, CBV and MTT were increasingly underestimated as MTT or the depolarization rate increased if depolarization was not taken into account. With a modified bolus-tracking theory depolarization could be compensated for, assuming that the depolarization rate was known. Three separate compensation methods were investigated experimentally and by numerical simulations.     

消毒器械供应链的信息化管理

[目的]对国内外消毒器械供应链的管理进行分析，为国内消毒器械供应链的跟踪管理提供依据。[方法]对国内外消毒器械供应链的信息化管理方式进行分析。[结果]消毒器械跟踪管理系统在国外已有成功应用的实例，效果良好；国内医疗机构至今还没有成功应用器械跟踪管理系统的相关报道。[结论]消毒器械跟踪管理系统是目前管理消毒器械供应链的有效途径。     

基于信任源模型的全科医疗服务医患信任问题及对策建议

在全科医疗服务制度背景下,增强医患信任是提升医疗服务质量的关键。基于医患信任源模型,结合文献分析,本文对全科医疗服务中的医患信任问题进行了深入探索,得出卫生行政部门对签约服务的监督力度、社区卫生服务机构的设施环境、全科医生提供的服务质量、居民自身的信任倾向是影响医患信任的关键因素。基于此,文章从四方主体角度出发,提出要加强卫生行政部门监管力度、提升制度信任、加强医患沟通、增强人际信任、发挥居民的社会监督力量等建议,以进一步提高居民对基层医疗卫生服务的利用意愿和全科医疗的服务质量。