Mr imaging of hepatic nodular regenerative hyperplasia

Nodular regenerative hyperplasia (NRH), a rare condition that is commonly associated with noncirrhotic portal hypertension, is not well described in the MR literature. Three patients at two institutions were identified who had both abdominal MR imaging and pathologic evidence of NRH. All examinations were performed at 1.5 T and included axial T1- and T2-weighted spin-echo (SE) images. The MR studies were reviewed by two radiologists in consensus. Two patients had multiple liver lesions that had high signal components on T1-weighted images and were predominantly isointense with liver on the T2-weighted images. One patient had no focal lesions identified. NRH, when visualized on MR images, appears as multifocal masses with shortened Tl and T2 similar to liver. NRH should be considered in the differential diagnosis of hepatocellular tumors, especially in patients with a predisposing condition.     

Immunology

A selection of interesting papers that were published in the two months before our press date in major journals most likely to report significant results in immunology.     

中医疲劳术语整理研究

以疲劳术语系列中的“倦类”为代表进行释义并阐述了整理疲劳术语的意义的目的。其意义和目的为：阐明中医疲劳的病因，病机，规范描述疲劳的术语，为探讨中医抗疲劳及调治亚健康的方药提供线索与依据。     

Single-shot ADC imaging for fMRI.

It has been suggested that apparent diffusion coefficient (ADC) contrast can be sensitive to cerebral blood flow (CBF) changes during brain activation. However, current ADC imaging techniques have an inherently low temporal resolution due to the requirement of multiple acquisitions with different b-factors, as well as potential confounds from cross talk between the deoxyhemoglobin-induced background gradients and the externally applied diffusion-weighting gradients. In this report a new method is proposed and implemented that addresses these two limitations. Specifically, a single-shot pulse sequence that sequentially acquires one gradient-echo (GRE) and two diffusion-weighted spin-echo (SE) images was developed. In addition, the diffusion-weighting gradient waveform was numerically optimized to null the cross terms with the deoxyhemoglobin-induced background gradients to fully isolate the effect of diffusion weighting from that of oxygenation-level changes. The experimental results show that this new single-shot method can acquire ADC maps with sufficient signal-to-noise ratio (SNR), and establish its practical utility in functional MRI (fMRI) to complement the blood oxygenation level-dependent (BOLD) technique and provide differential sensitivity for different vasculatures to better localize neural activity originating from the small vessels.     

Calretinin immunoreactive structures in the human hippocampal formation

The calcium-binding protein calretinin is present in an intrinsic GABAergic and an extrinsic non-GABAergic system in the rat and monkey hippocampal formation. Important species differences have been noted in hippocampal cell types immunostained for calretinin and the termination pattern of calretinin containing hypothalamic afferents in the hippocampus. In the present study, calretinin-containing neurons were visualized using immunocytochemistry in the human hippocampal formation of individuals which showed no significant neuropathological alterations. Calretinin-immunoreactivity was present exclusively in non-granule cells of the dentate gyrus and in non-pyramidal cells of Ammon's horn. Calretinin-positive neurons were found most frequently in the hilus of the fascia dentata and in strate radiatum and lacunosum-moleculare of CA1, whereas neurons in CA2 and CA3 were rarely immunostained. The majority of calretinin-immunoreactive neurons were small, bipolar or fusiform neurons. The dendritic trees of the calretinin-positive neurons were, for the most part, parallel to the dendrites of the principal cells. In the hilus, however, we observed cells with dendrites restricted to the hilar area. These dendrites were parallel to the granule cell layer. In the stratum lacunosum-moleculare, neurons with dendrites oriented parallel to the hippocampal fissure were frequently detected. In general, dendrites were smooth or sparsely spiny, displaying small conventional spines. The axons usually emerged from the proximal dendrite and could be followed over long distances. Axons were thin, had small varicosities and displayed only few collaterals which branched relatively far away from the cell body. Distinct bands of darkly stained calretinin-positive fibers occupied the innermost portion of the dentate molecular layer and the pyramidal cell layer of CA2. This distribution of calretinin-immunoreactive structures in the human hippocampus is similar to that observed in other primates but differs from that described in lower mammals, i.e., the rat. Our findings suggest that primates may share a common hippocampal calrtinin-containing system, presumably both the intrinsic GABAergic and the extrinsic hypothalamic non-GABAergic components. © 1995 Wiley-Liss, Inc.     

ATTITUDES TOWARDS AND KNOWLEDGE OF OCCUPATIONAL SKIN DISEASE AMONGST SUPPORT PERSONNEL

Liaison with support personnel is important in the management of workers with occupational skin disease (OSD). This study shows that there are many areas of concern regarding the knowledge and understanding of OSD in these groups. There needs to be a comprehensive education programme concerning OSD within the working community and support personnel. Dermatologists need to simplify their "language' in the reporting of OSD. Insurers need to take a more sympathetic attitude towards the partially fit worker. Rehabilitation personnel must become more familiar with OSD.     

台湾早期之教会医学

台湾如同中国本土一样,其现代医学的开端系来自西方基督教传教士的医疗。虽然１７世纪荷兰人曾带来了西方医学,但是当郑成功驱逐了荷兰人,西方医学也随之自台湾消失。１８６５年英国长老教会派遣马雅各医师来台从事医疗传教,才使西方医学在台湾生根。１９世纪最后的３０年是台湾近代医学史的关键时期。本文就台湾早期教会医学的三位重要人物：马雅各医师、马偕博士、兰大卫医师之主要事迹和他们对台湾近代医学的贡献加以整理叙述。     

Application of Akaike's information criterion (AIC) in the evaluation of linear pharmacokinetic equations

According to linear pharmacokinetics, the time course of plasma concentration of a drug, C_p,is expressed by a sum of exponential functions, C_p= _i=1 ⁿ a_i .This article describes a statistical technique to estimate the number of exponential terms, n,for the time course of drug by the application of Akaike's information criterion (AIC). Plasma concentrations of ethoxybenzamide, sulfisoxazole, bishydroxycoumarin, and diazepam measured following bolus intravenous injection were used as clinical examples for this method. Selection of models is compared between the AIC method and an Ftest method at significance levels of 5% and 1%.