F wave studies after intrathecal methotrexate administration

Electrophysiological examinations were done on 20 patients aged 40–71 years with recently diagnosed high grade non-Hodgkin's lymphomas. General chemotherapy and intrathecal chemotherapy in order to prevent central nervous system (CNS) involvement were begun. On the first day of chemotherapeutic cycle patients received intrathecally methotrexate (ITMTX) and prednisolone. Electrophysiological study was carried out twice in each subject: before ITMTX injection and a day after injection. The study procedure included: a conventional nerve conduction examination (peripheral conduction velocity and compound muscle action potential amplitude), the F wave latency and amplitude measurement and F ratio (F-M-1/2M) calculation for peroneal and tibial nerve bilaterally. Results of the first and the second examinations were statistically compared by t-Student's test. No significant differences between values of estimated parameters were found. The study revealed no recent alterations in proximal, paraspinal motor conduction and motor neuron excitability due to antidromical activation after single ITMTX administration.     

高危出血患者应用吉派林抗凝血液透析疗效观察

目的：观察危重型肾功能衰竭合并高危出血患者选择抗凝药物进行血液透析治疗的效果。方法：应用吉派林(低分子肝素钠)作为抗凝剂进行血液透析。结果：129例病人进行血液透析386次，均没有出血发生。结论：吉派林在高危出血患者血液透析中使用方便，安全，效果良好。     

颅脑超声对高原新生儿缺氧缺血性脑病观察及探讨

本文对西宁地区新生儿缺氧缺血性脑病（ＨＩＥ）颅脑超声诊断分析脑缺氧缺血产生的原因、脑实质损伤程度及预后评估。提出对围产期窒息导致脑缺血性损害的预防措施。     

Functional aspects of serotonin transmission in the basal ganglia: a review and an in vivo approach using the push-pull cannula technique

Peripheral deafferentation of the rodent olfactory bulb results in loss of dopamine content, tyrosine hydroxylase activity and immunocytochemical staining for tyrosine hydroxylase in juxtaglomerular dopamine neurons. Reinnervation of the bulb by afferent neurons results in the return of all parameters to control levels suggesting that the dopamine neurons did not degenerate but that the expression of tyrosine hydroxylase enzyme was transneuronally regulated in a static population of juxtaglomerular cells. To evaluate this possibility, we determined the activity and immunocytochemical localization of the second enzyme in the dopamine biosynthetic pathway, DOPA decar?ylase. At a time when tyrosine hydroxylase activity was reduced to 25% of control values, DOPA decar?ylase activity in the lesioned bulb was maintained at about 65% of that in the unlesioned bulb. Immunocytochemical staining with antibodies to both enzymes, performed sequentially in the same sections, demonstrated that in the unlesioned bulb tyrosine hydroxylase and DOPA decar?ylase are co-localized in the same population of juxtaglomerular neurons. Similar results were obtained in adjacent sections each stained with one of the two antibodies. In contrast, in the deafferented bulb, about three times as many neurons were stained with DOPA decar?ylase as with tyrosine hydroxylase antibodies. The DOPA decar?ylase activity measurements and immunocytochemistry argue for the continued presence, in the lesioned olfactory bulb, of a population of tyrosine hydroxylase deficient dopamine neurons.The data suggest that olfactory receptor cell innervation transneuronally regulates the expression of tyrosine hydroxylase by mechanisms separate from those controlling the levels of DOPA decar?ylase.     

A sleep disturbance in high risk for SIDS infants

A developmentally immature sleep pattern has been identified in infants with a recent history of an unexplained life-threatening episode of sleep apnoea who are considered at risk for SIDS. In these infants there is a persistence of Sleep Onset REM Periods (SOREMPS) after prolonged wakefulness when compared to controls matched for age, sex, birthweight and race. This sleep characteristic has not been previously reported.     

基于线性调频信号的高帧率超声成像系统

基于有限衍射波束的高帧率超声成像系统能实现快速成像，但由于仅通过一次发射事件成像，信噪比较低，本研究针对该问题提出一种改进方案。它采用合成孔径雷达中所使用的线性调频信号作为激励信号，在接收端则利用线性调频信号的脉冲压缩比等于信号的时间带宽积的特征，将接收信号通过匹配滤波器处理。结果表明该方案不仅能显著提高成像系统的信噪比，改善重构图像的质量，增加成像深度，而且不损失分辨率。     

Multidimensional Chromatographic and Hyphenated Techniques for Hydrophilic Copolymers, 1

Summary: The chromatographic analysis of hydrophilic copolymers is complicated due to the fact that in most cases aqueous eluents must be used. In aqueous eluents different polar and ionic effects may disturb the selective interactions between the macromolecules and the stationary phase making it impossible to separate such copolymers with regard to chemical composition. Therefore, 2D chromatography combining a separation according to composition with a separation according to molar mass has been applied mostly to polymers that are soluble in organic solvents. The present contribution describes experimental approaches to analyze such hydrophilic copolymers by 2D‐chromatography. For a model polymer system resulting from the copolymerization of methacrylic acid and a poly(ethylene glycol) macromonomer, it is shown that different analytical techniques including SEC, LC‐CC, MALDI‐TOF MS and 2D chromatography can be used to analyze the different parameters of molecular heterogeneity of such copolymers.

2D separation of poly(MPEG‐MM 2), 1^st dimension: LC‐CC, 2^nd dimension: SEC.