下肢骨肉瘤的MRI与X线对照研究

目的 对比分析下肢骨肉瘤的X线与MRI表现，探讨MRI对骨肉瘤的诊断价值。方法 收集经手术或病理穿刺活检证实的下肢骨肉瘤15例，男11例，女4例，均行MRI平扫及增强扫描（4例行CT扫描），并摄有X线平片，对其MRI征象与X线征象作逐一对比。结果 MRI及X线平片对下肢骨肉瘤的诊断准确率均为100％，MRI在显示病变范围、放射状骨针、Codman三角两层结构以及跳跃病灶等方面明显优于X线平片检查。结论 X线平片是诊断骨肉瘤最简便而实用的方法，但MRI可以更好的显示病变的范围，发现早期病变。     

头皮原发性皮肤神经节细胞瘤

神经节细胞瘤是一种神经内分泌肿瘤，其发生与自主神经系统的交感或副交感神经节有关。罕见发生于膀胱、前列腺和子宫。本文作者报道1例发生于儿童头皮的原发性皮肤神经节细胞瘤。对此肿瘤进行了组织学、免疫组化和超微结构研究。该病例可能代表神经嵴细胞向鳃弓发育过程中的一种异常迁移。此外，研究结果还强调在胚胎发育过程中神经嵴和鳃弓／裂之间有复杂的相互作用。     

Analysis of standard and non-standard visual word format in the two hemispheres

A dual-route model for the recognition of written words is hypothesised. The model postulates that the two cerebral hemispheres differ in their sensitivity to the visual format of verbal stimuli. Such stimuli may be 'standard', that is in Standard Visual Format (SVF), or "non-standard", i.e. in non-standard Visual Format (NSVF). In the left hemisphere (LH), SVF words are routed directly to the lexicon, while NSVF words must go through an additional encoding phase prior to lexicon access. In the right hemisphere (RH) all words (SVF and NSVF) must proceed to an additional encoding phase prior to accessing the lexicon. Two lateralized lexical decision experiments are reported. In Section 2, angle of orientation was used to define SVF and NSVF. In Section 3, presentation of verbal stimuli was preceded by a cue indicating whether the coming lexical stimulus was in SVF or NSVF, while SVF was defined as in Section 2. The results showed that the difference in RT, favouring RVF stimulation was found for orientations up to 30 degrees. Greater angles of presentation significantly reduced RVF superiority. The largest differences between responses to stimuli presented to the two visual fields was found when word stimuli were in SVF (up to 30 degrees ) and presented after a priming cue. The results are discussed in terms of the model, but alternative explanations are suggested.     

Bihemispheric sensitivity to sentence anomaly

This study investigated cerebral asymmetries in sensitivity to sentence-level semantic anomaly. To separate the effects of anomalous message processing from those attributable to low sentence constraint, low-constraint sentence-fragment primes were followed by target words presented to the left or right visual fields. When completed by the target word, the sentences represented either normal or anomalous messages; in addition, one-half of the sentence primes contained a word strongly related to the target. Targets presented to both the left and right visual fields were advantaged by the presence of a related word, and disadvantaged by the presence of a semantically anomalous message. Contrary to some previous claims, this result implies that the right hemisphere can construct some message-level interpretations from sentences, such that semantic anomaly is registered, even if finer gradations of sentence constraint are not. This rudimentary integration of word meanings in sentences may provide a scaffolding for right hemisphere discourse processing. In light of these findings, we propose a revised view of left/right hemisphere differences in the processes used to interpret sentence meaning.     

一例AML中一种新的TCRδ基因重排及其分析方法

Ｔ细胞抗原受体（ＴＣＲ）功能的表达有赖于该基因在正常Ｔ淋巴细胞发育过程中的重排。近年来，已发现一些肿瘤及白血病中出现该基因的异常重排。我们采用聚合链反应（ＰＣＲ）、“磁珠”固相纯化方法和ＰＣＲ产物直接测序等方法，从一例ＡＭＬ中发现了一种在白血病中未报道过的ＴＣＲδ基因重排，该重排是一种新报道的Ｄδ区ＤδＸ片段的重排，为ＤδＸＤδＤδＪδ不完全重排。在研究白血病ＴＣＲ基因重排中，采用本文所报道的方法     

Epogam evening primrose oil treatment in atopic dermatitis and asthma

Essential fatty acids are claimed to have positive effects in atopic diseases. In a double blind, placebo controlled, parallel group study 58 out of 60 children, with atopic dermatitis and the need for regular treatment with topical skin steroids, completed a 16 weeks' treatment period with either Epogam evening primrose oil or placebo capsules. Twenty two of these subjects also had asthma. The parents used diaries to record symptom scores and concomitant medication. Peak expiratory flow was measured and disease activity was monitored by the clinician every four weeks. The plasma concentrations of essential fatty acids increased significantly in the group treated with Epogam capsules. The study demonstrated significant improvements of the eczema symptoms but no significant difference was found between the placebo and the Epogam groups. No therapeutic effect was shown on asthma symptoms or fidget.     

Pericardial effusion complicating a percutaneous central venous line in a neonate

A premature infant developed pericardial effusion four days after the insertion of a 25-gauge silastic percutaneous central venous catheter. The effusion contained parenteral nutrition fluid and resolved rapidly after withdrawal of the catheter. Pericardial effusion is a potential complication of percutaneous, as well as surgically placed, central venous catheters.     

The STR system in the human phenylalanine hydroxylase gene: true fragment length obtained with fluorescent labelled PCR primers

We present a simple, fast, non-radioactive method for the analysis of the polymorphic short tandem repeat (STR) system in the human phenylalanine hydroxylase gene. Previously, sizing of the STR marker involved radiolabelling of PCR amplified fragments and resolution on denaturing polyacrylamide gels using M13 sequencing ladder as a standard. However, this method consistently gave sizes 2 bp longer than the known sequence. The fluorescent method presented here employs internal lane standards and enables accurate sizing of the fragments. To avoid confusion, we suggest that the true fragment lengths are used as reference values in the future. The analysis of STR alleles is valuable for population genetic studies and for targeted mutation screening in phenylketonuria (PKU). It can replace RFLP-based haplotype analysis for carrier detection, and we report its use for prenatal diagnosis in a Northern Irish family with PKU. The analysis of 250 Northern Irish chromosomes, including 128 PKU alleles, showed no significant difference between normal and PKU alleles, with fragment lengths of 238 and 242 bp most common in both groups.     

Molecular analysis of PKU in Ireland

Classical phenylketonuria (PKU: McKusick No. 261600) is caused by mutations occurring at the phenylalanine hydroxylase (PAH) locus on chromosome 12 and has a prevalence in Ireland of 1 in 4500. We examined 304 independent alleles from 350 patients for the presence of six mutations and have characterized VNTR alleles within the minisatellite region 3' to the PAH gene in patients carrying the most prevalent mutation. R408W was the most common mutation found, with a relative frequency of 42%. All other mutations had relative frequencies of <10%. VNTR analysis showed that the R408W mutation is associated with the VNTR-8 allele in the Irish population, indicating that R408W is associated with RFLP haplotype 1. This differs from that reported from eastern Europe where R408W is associated with RFLP haplotype 2/VNTR-3; an observation which has led several groups to propose a Balto-Slavic origin for this mutation. These results support the hypothesis of a second, independent founding event for the R408W mutation on an RFLP haplotype 1 VNTR-8 chromsome background in the Irish/Celtic population.