胸腹水中唾液酸含量在鉴别良恶性疾病上的价值

本文测定恶性、炎性和肝硬化3组胸腹水中的总唾液酸(TotalSialic Acid TSA)和脂质结合唾液酸(Lipid-bound Sialic Acid LSA)含量,结果表明恶性组和炎性组的 TSA 和 LSA 明显高于肝硬化组,但恶性组和炎性组的 TSA 和 LSA 则无明显差异。恶性、炎性和肝硬化组的 TSA 值分别为499.52±183.98mg/L、508.68±208.79mg/L 和117.71±70.46mg/L;LSA则分别为146.28±103.62mg/L、115.26±72.13mg/L 和58.90±35.46mg/L。以肝硬化组的 TSA+2SD 作为恶性组和肝硬化组的鉴别值,其敏感性为88%,特异性为90.47%,有效性为89.13%。LSA 则无鉴别价值。     

Identification of functional GRP-preferring bombesin receptors on human melanoma cells

Bombesin was originally isolated from amphibian skin, wherease its mammalian counterpart, gastrin-releasing peptide (GRP), was first identified in the nervous system of the gastrointestinal tract. Whether GRP is present in the human skin is not known. Bombesin-like peptides are also known to modulate growth. We therefore investigated whether human melanoma cell lines express functional GRP-preferring bombesin receptors and whether they alter growth or other specific cellular functions of these tumour cells. GRP receptor mRNA was found in HBL, D-10, Me-28 and A375-6 cell lines, but only A375-6 cells express a large number of high-affinity binding sites for [¹²⁵I]-[Tyr⁴] bombesin ( K _d 0.31 ± 0.04 nmol L⁻¹, 3880 ± 429 binding sites per cell). Bombesin dose-dependently increased cytosolic calcium, but did not alter interleukin (IL) 1β-induced reduction of cell viability or IL-6 secretion, both A375-6-specific cell functions. Growth of A375-6 cells was not altered by bombesin or the specific GRP receptor antagonist BIM26226 as measured by [³H]-thymidine incorporation or methylene blue assay, whereas insulin alone or in combination with other potential growth factors dose-dependently stimulated growth of these cells. The newly characterized GRP-preferring bombesin receptors on highly malignant human melanoma cells could initiate studies of growth effects on solid tumours or in vivo scanning using radiolabelled tracers.     

Differential changes of nicotinic receptors in the ratbrain following ibotenic acid and 192-IgG saporin lesionsof the nucleus basalis magnocellularis

The basal forebrain cholinergic neurons are implicated in the pathogenesis ofneurodegenerative diseases including Alzheimer^fn2s disease (AD). The nicotinic acetylcholine receptors (nAChRs) have been found to besignificantly afflicted in AD. To study the underlying mechanisms for dysfunction of the basalforebrain cholinergic neurons development of suitable animal models is warranted. In this studywe investigated the effects of bilateral lesions of the nucleus basalis magnocellularis on nAChRs inthe rat brain using the cholinergic system selective immunotoxin 192-IgG saporin andnon-selective excitotoxin ibotenic acid. Changes in nAChRs were measured by ³H-cytisineand ³H-epibatidine, two ligands with different selectivity for nAChRs subtypes. Inthe parietal cortex of ibotenic acid lesioned rates, the choline acetyltransferase activity (ChAT)was decreased by 24% while no changes were detected in the frontal cortex or hippocampus.Similarly, a 40% decrease was observed in the number of nAChRs labelled by ³H-cytisine,but not by ³H-epibatidine, in the parietal cortex, while no changes were found in thefrontal cortex or hippocampus. Although the 192-IgG saporin induced lesions reduced the ChATactivity in the frontal cortex, parietal cortex and hippocampus by 77, 50 and 21%, respectively, nochanges were observed in the number of nAChRs as studied by ³H-cytisine or ³H-epibatidine. The results indicate a difference in vulnerability of the cortical nAChRsubtypes to experimental lesions of the nucleus basalis magnocellularis. The findings in this studysuggest that a major portion of the nAChRs might be located on non-cholinergic neurons in thebrain.     

Growth and differentiation of adult rat hepatocytes regulated by the interaction between parenchymal and non-parenchymal liver cells

We have devised a medium which supports the continuous growth of hepatocytes without losing their replicative potential and differentiation capacity for a longer period. The medium HCGM, contains four key substances in addition to foetal bovine serum. They are epidermal growth factor, nicotinamide, ascorbic acid 2-phosphate and dimethylsulphoxide. When a non-parenchymal cell fraction containing small hepatocytes and non-parenchymal cells was cultured in HCGM, small hepatocytes grew clonally and differentiated into cells expressing either mature hepatocyte marker proteins or biliary cell marker proteins. Thus, for the first time, we showed the presence of a small compartment of bipotent and highly replicative clonogenic hepatocytes in the rat adult liver. HCGM also supported the growth of stellate cells (Ito cells) which were in the original preparation, suggesting the important role of stellate cells for the successful cultivation of hepatocytes. Together, these results suggest that a microenvironment is produced as a result of cooperative interactions between hepatocytes and stellate cells: one which stimulates the growth and differentiation of clonogenic hepatocytes.     

Synthesis and Antitumour Activity of New Derivatives of Flavone-8-acetic Acid (FAA). Part 1: 6-Methyl Derivatives

A range of 17 derivatives of flavone-8-acetic acid (FAA) with a 6-methyl substituent have been prepared and their anti-tumour activity evaluated in vitro against a panel of human and murine tumour cell lines and in vivo against MAC 15A. While many of the compounds show activity comparable to FAA in vitro, this essentially disappears in vivo, possibly due to degradation before the compounds can reach the tumour site.     

酸性染料比色法测定甲氧异腈冻干品含量

本文采用酸性洒料比色法测定甲氧异腈冻干品的含量。结果表明，使用溴甲酚紫１．５ｍｌ，ＰＨ值为６．０的磷酸盐缓冲液５ｍｌ，氯仿５ｍｌ提取，经振摇２ｍｉｎ，静置１５ｍｉｎ为较理想比色条件，显色液稳定，甲氧异腈浓度在４－２０μｇ／ｍｌ范围内与吸收度呈良好线性关系。     

Constitutional heteromorphism of 9q13→q21 in a patient with chronic myelogenous leukemia

An apparently balanced de novo reciprocal translocation t(5;21) (q13;q22) was demonstrated in a girl with acrobrachycephaly, ventriculomegaly, pulmonary stenosis and anal malformation. The possible relationships between her karyotype and malformations are discussed.     

Niflumic acid-induced increase in potassium currents in frog motor nerve terminals: effects on transmitter release

The actions of the nonsteroidal antiinflammatory drug niflumic acid were studied on frog neuromuscular preparations by conventional electrophysiological techniques. Niflumic acid reduced the amplitude and increased the latency of endplate potentials in a concentration-dependent manner. Neuromuscular junctions pretreated with niflumic acid (0.05–0.5 mM) showed much less depression than control when they were stimulated with trains of impulses. Inhibition of acetylcholine release was reverted by raising the extracellular Ca²⁺ concentration but not by simply washing out the preparations with niflumic acid-free solutions. Pretreatment with indomethacin (0.1 mM), another nonsteroidal antiinflamatory drug, did not affect the niflumic acid-induced inhibition of evoked responses. Niflumic acid (0.1 mM) did not change the amplitude of miniature endplate potentials and had a dual action on the frequency of miniatures: it decreased their frequency at 0.1 mM whereas it produced an enormous increase in the rate of spontaneous discharge at 0.5 mM. Niflumic acid (0.1–1 mM) reversibly increased the amplitude and affected the kinetics of presynaptic voltage-activated K⁺ current and Ca²⁺-activated K⁺ current in a concentration-dependent manner. Niflumic acid (0.1–1 mM) irreversibly decreased the amplitude and reversibly affected the kinetics of the nodal Na⁺ current. Indomethacin (0.1 mM) had no effect on presynaptic currents. In conclusion, niflumic acid reduces acetylcholine release by increasing presynaptic K⁺ currents. This may shorten the depolarizing phase of the presynaptic action potential and may reduce the entry of Ca²⁺ with each impulse.     

酶活性法测定GAD抗体及其初步临床应用

目的建立测定谷氨酸脱羧酶（ＧＡＤ）抗体的方法，以探讨该抗体对胰岛素依赖型糖尿病（ＩＤＤＭ）的预测、早期诊断及其发病机制研究的意义。方法用专用酶反应试管建立放射性同位素底物测定ＧＡＤ活性的分析方法。结果底物浓度为４ｍｍｏｌ／ｍｌ（３７ｋＢｑ）时，酶活性测定在一定浓度范围内剂量效应呈直线关系（ｒ＝０９８９）。结合免疫沉淀与酶活性分析，建立了免疫沉淀酶活性分析测定ＧＡＤ抗体的方法，２份ＩＤＤＭ患者ＧＡＤ抗体阳性血清与酶活性免疫沉淀指数存在剂量效应关系。用免疫沉淀酶法测定１５例正常人及２０例病程１年以内的ＩＤＤＭ患者血清，两组酶活性免疫沉淀指数分别为０１９３±００８７和０３８１±０１２１，差异有显著性（Ｐ＜００１）。按照超过正常人组免疫沉淀指数ｘ＋２ｓ为阳性区分，２０例ＩＤＤＭ患者血清中ＧＡＤ抗体阳性９例，占４５％。结论该方法简单，能直接反映酶活性的改变，无需高纯度的ＧＡＤ，特别适用于刚开始从事ＧＡＤ抗体研究的实验室及阳性血清筛查。