HNO3和有机介质中U（Ⅳ）的稳定性研究

研究了ＨＮＯ＿３和ＴＢＰ－煤油介质中Ｕ（Ⅳ）的稳定性。测定了两种介质中Ｕ（Ⅳ）、ＨＮＯ＿３、ＴＢＰ浓度和气相中氧浓度对Ｕ（Ⅳ）氧化速率的影响。Ｕ（Ⅳ）的氧化速率都随温度提高而明显增加．其表观活化能分别为９１ｋＪ／ｍｏｌ（ＨＮＯ＿３介质）和４２ｋＪ／ｍｏｌ（ＴＢＰ－煤油介质）。对两种介质中Ｕ（Ⅳ）的氧化速率规律进行了比较。     

Diagnostic value of the study of caffeine elimination in chronic liver diseases

Data from the past few years have shown that as caffeine metabolizes solely in the liver, caffeine elimination can serve as a liver function test. We have collected data by monitoring 40 persons with liver diseases (11 chronic alcoholic hepatitis, 24 liver cirrhosis, 5 non-cirrhotic liver disease). Eight subjects served as controls. The patients with liver cirrhosis were classified according to the Child--Pugh scoring system. To determine caffeine elimination blood samples were collected before and at 3, 6, 9 and 12 hours after oral administration of 0.2 g caffeine. Fasting serum caffeine concentration and concentration 12 hours after administration, serum clearance, half life, peak concentration and volume of distribution have been compared. The respective values measured in patients with non-cirrhotic liver diseases did not differ significantly from the controls. The disappearance of caffeine was significantly decreased in cirrhotics. Our results demonstrated a good correlation between impairment of caffeine elimination and assessment of severity of liver disease by the Child--Pugh classification. Measuring serum levels in samples taken 12 hours after caffeine administration is a simple and useful method in the diagnosis of liver diseases at cirrhotic stage.     

小剂量辐射对肿瘤细胞K_（562）及肿瘤病人天然杀伤细胞（NK）活性的影响

已知小剂量辐射可增强机体免疫功能。从对高本底地区的调查发现，该地区居民肿瘤死亡率及某些肿瘤发病率有所降低（１）。ＮＫ细胞能直接杀伤肿瘤细胞，在肿瘤免疫中起着重要的作用。本文观察小剂量辐射对肿瘤病人和正常人外周血淋巴细胞ＮＫ活性的相对效应以及对人红白血病细胞（Ｋ（５６２）细胞）的影响，以期从体外买验来探索较小剂量辐射对肿瘤治疗的影响     

The influence of semantic encoding on recognition memory in Alzheimer's disease

Within the framework of the distinction between episodic and semantic memory, it has been argued that these two memory systems are organised in a hierarchical way. The hierarchical hypothesis assumes that episodic memory is a specific subsystem of semantic memory and therefore implies that episodic memory cannot exist without semantic memory. If this hypothesis is correct, it should be expected that patients with impaired semantic memory also have impaired episodic memory. In the present study, two experiments investigated the influence of semantic encoding on recognition memory performance in a population of 20 patients with Alzheimer's disease and 18 normal controls. Both experiments assessed recognition memory for semantically-related items. In Experiment 2, but not in Experiment 1, subjects were explicitly instructed to make a semantic association between the items. Alzheimer's disease patients were impaired, compared to the normal controls, on the recognition memory performance of both experiments. The ability to make a semantic association between two items was significantly and positively correlated with the subjects' performance on the recognition tasks. A further analysis showed that patients who were impaired on the semantic association task did significantly worse on the recognition task of Experiment 2 than normal controls and patients who were unimpaired on the semantic association task. These findings are discussed in the context of memory deficits in Alzheimer's disease, and are interpreted as supporting the view that episodic memory for an item is affected by the level of semantic awareness of that same item.     

Clinical chemistry of common apolipoprotein E isoforms

Apolipoprotein E plays a central role in clearance of lipoprotein remnants by serving as a ligand for low-density lipoprotein and apolipoprotein E receptors. Three common alleles (apolipoprotein E(2), E(3) and E(4)) give rise to six phenotypes. Apolipoprotein E(3) is the ancestral form. Common apolipoprotein E isoforms derive from nucleotide substitutions in codons 112 and 158. Resulting cysteine-arginine substitutions cause differences in: affinities for low-density lipoprotein and apolipoprotein E receptors, low-density lipoprotein receptor activities, distribution of apolipoprotein E among lipoproteins, low-density lipoprotein formation rate, and cholesterol absorption. Accompanying changes in triglycerides, cholesterol and low-density lipoprotein may promote atherosclerosis development. Over 90% of patients with familial dysbetalipoproteinaemia have apolipoprotein E(2)/E(2). Apolipoprotein E(4) may promote atherosclerosis by its low-density lipoprotein raising effect. Establishment of apolipoprotein E isoforms may be important for patients with diabetes mellitus and several non-atherosclerotic diseases. Apolipoprotein E phenotyping exploits differences in isoelectric points. Isoelectric focusing uses gels that contain pH 4-7 ampholytes and urea. Serum is directly applied, or prepurified by delipidation, lipoprotein precipitation or dialysation. Isoelectric focusing is followed by immunofixation/protein staining. Another approach is electro- or diffusion blotting, followed by protein staining or immunological detection with anti-apolipoprotein E antibodies and an enzyme-conjugated second antibody. Apolipoprotein E genotyping demonstrates underlying point mutations. Analyses of polymerase chain reaction products are done by allele-specific oligonucleotide probes, restriction fragment length polymorphism, single-stranded conformational polymorphism, the primer-guided nucleotide incorporation assay, or denaturating gradient gel electrophoresis. Detection with primers that either or not initiate amplification is performed with the amplification refractory mutation system. Disparities between phenotyping and genotyping may derive from isoelectric focusing methods that do not adequately separate apolipoprotein E posttranslational variants, storage artifacts or faint isoelectric focusing bands.     

Decision by the Principle Board of the Polish Allergy Society

A review of isolates of Neisseria meningitidis and other laboratory evidence of meningococcal infection was carried out for the period 1990-1995. Thirty-three patients with evidence of meningococcal disease were identified over the six year period. Group B organisms were the most commonly identified, but an increase in Group C has occurred and is almost equal in number. Data from clinical, laboratory and public health sources should be centralized in a National Surveillance Centre.