Effects of adrenergic agents, theophylline and other drugs on dextran edema and histamine release in rats

Pretreatment of rats with various catecholamines, theophylline and dibutyryl cyclic AMP decreased the reaction to dextran and reduced the associated release of histamine into the plasma. Protection by the catecholamines was inhibited by the β-blocker, propranolol. Some of these protective drugs owed their effectiveness in large part to the production of hyperglycemia. However, it appeared likely that they also acted directly on the mast cells to prevent the release of histamine and other vasoactive factors, as previously observed in vitro. Phenoxybenzamine, nicotinamide and ethanol also afforded protection not explainable by effects on blood sugar.     

Drinking induced by dextran and histamine: relation to kidneys and renin

Intravenous injection of dextran (M.W. 70,000) to rats caused an increased water intake which was accompanied by elevation of plasma renin activity (PRA). The thirst-inducing effect of dextran was abolished by nephrectomy but was unaffected by ureteral ligature. Dextran-induced thirst was blocked by propranolol and by diphenhydramine but the elevation of PRA caused by dextran was not reduced by either of these drugs. Histamine injected subcutaneously to rats increased water intake and elevated PRA. Histamine-induced thirst was only partly reduced after nephrectomy or following administration of propranolol but was completely abolished by diphenhydramine. The elevation of PRA by dextran outlasted the period of increased drinking. The mechanisms involved in the drinking induced by dextran with relation to the kidney, renin and site of action of various blockers are discussed.     

Inhibitory effects of carbohydrates on histamine release and mast cell disruption by dextran

Alloxan diabetic rats failed to show the skin reaction (blue spot) evoked by dextran, whereas the effects produced by histamine and compound 48/80 were not altered. When dextran and glucose were injected simultaneously into the skin the reaction was inhibited. In vitro, mast cell alterations produced by dextran occurred simultaneously with histamine release; both processes were inhibited by glucose, other carbohydrates related to glucose, and inhibitors of anaphylaxis. These experiments suggest that dextran releases histamine by a mechanism similar to that found with 48/80 and anaphylaxis in the rat. The inhibitory effect of carbohydrates may be understood on the basis of a competitive mechanism.     

脑星形细胞瘤瘤周水肿与肿瘤血管生成的相关性研究

目的 探讨星形细胞瘤瘤周水肿与肿瘤血管生成及病理分级的相关性。方法 分析了60例经病理证买及免疫组化染色的星形细胞瘤的瘤周水肿与微血管密度（MVD）、肿瘤恶性程度、部位和大小的关系。结果 瘤周水肿与MVD、肿瘤的良恶性、部位及大小呈正相关，Ⅰ级星形细胞瘤的瘤周水肿轻，Ⅱ～Ⅳ级瘤周水肿明显；位于皮髓交界区的肿瘤，瘤周水肿最明显；肿瘤越大，水肿越明显。结论 星形细胞瘤瘤周水肿与MVD、病理分级、部位及大小关系密切，Ⅱ度以上的瘤周水肿，97．4％为Ⅱ～Ⅳ级星形细胞瘤；肿瘤直径大于5．8cm，多为Ⅱ～Ⅳ级星形细胞瘤。     

Selective inhibition by vasocortin of histamine release induced by dextran and concanavalin-A from rat peritoneal cells

Vasocortin, a glucocorticoid-induced anti-inflammatory protein, has been purified from the peritoneal lavage fluid of dexamethasone-treated rats. Vasocortin inhibited the release of histamine from rat peritoneal cells stimulated by dextran or concanavalin A but did not alter the release induced by calcium ionophore A23187 or compound 48/80. This selective effect exhibited by vasocortin mimics the glucocorticoid inhibition of histamine release from rat mast cells.     

Novel anti-HIV-1 activity produced by conjugating unsulfated dextran with polyL-lysine

A conjugate of polyL-lysine (PLL) with unsulfated dextran produced by reductive amination was found to have remarkable anti-HIV-1 activity against both the macrophage-tropic R5 virus Ba-L and T-cell line tropic X4 virus IIIB strains, although neither PLL nor dextran has such activity. The conjugate is a pseudoproteoglycan (pseudoPG) that simulates the structure of a proteoglycan. Conjugation with dextran was found to produce an antiviral effect in three kinds of assay systems including a human CD4(+) T-cell line, and the pseudoPG synthesized using 10 kDa PLL and 10 kDa dextran showed EC(50) 4-40 times lower than that of sulfated dextran or heparin against Ba-L and EC(50) equal to that against IIIB, indicating that PLL-dextran (PLL-Dex) was more effective against R5 virus than sulfated polysaccharides. PLL-Dex significantly suppressed a clinically isolated R5 virus from primary peripheral blood mononuclear cells. PLL-Dex interacted with the virus during adsorption to the cell and also decreased virus entry into the cell, suggesting PLL-Dex has multiple preventive mechanisms against HIV-1.     

Recent advances in molecular pharmacology of the histamine systems: immune regulatory roles of histamine produced by leukocytes

Accumulating evidence has highlighted the importance of histamine in immune responses. The H1 receptor is involved not only in allergic inflammatory reactions but also in augmentation of helper T cell (Th)1 responses, whereas H2 receptor suppresses Th responses and participates in immune tolerance through interleukin-10 and transforming growth factor-beta. Identification of the H4 receptor, which binds to histamine with high affinity and of which expression is limited to the hematopoietic system, has enhanced the importance of histamine in immune responses. However, since a majority of previous studies has evaluated the effects of exogenous histamine, it remains largely unknown how endogenously produced histamine is involved in regulation of such kinds of immune responses. Insight into precise roles of histamine in the immune system can not be obtained without correct understanding of both the predominance of a certain type of histamine receptor and the regulation of histamine synthesis. Here we review a part of the recent progress in histamine research in the field of immunology with attention to the source of involved histamine.     

骨创伤患者创伤后血浆D-二聚体水平与创伤程度的相关性研究

目的 研究骨创伤患者创伤后血浆D-二聚体水平与创伤程度的相关性.方法 选取骨创伤125例住院患者作为观察组,选取同时段进行健康体检的130例体检者作为对照组.比较对照组的血浆D-二聚体水平和观察组患者伤后不同时间点(第1、3、5、10天)的血浆D-二聚体水平.将观察组125例住院患者按照创伤程度的不同分为轻伤组、重伤组、严重伤组,统计不同创伤程度的各组各个检测时间点的血浆D-二聚体水平,分析骨创伤患者创伤后血浆D-二聚体水平与创伤程度的相关性.结果 观察组各个检测时间点血浆D-二聚体水平均高于对照组(P＜0.05),且随着骨创伤后时间的延长,观察组血浆D-二聚体水平有逐渐下降的趋势(F=53.2,P=0.02):观察组各个检测时间点血浆D-二聚体水平严重伤组＞重伤组＞轻伤组(P＜0.05);Person相关分析显示,骨创伤患者创伤后血浆D-二聚体水平与创伤程度呈正相关(r=0.61,P=0.03).结论 骨创伤后患者血浆D-二聚体水平快速升高,之后逐渐下降;骨创伤患者创伤后血浆D-二聚体水平与创伤程度呈正相关,临床上可将血浆D-二聚体水平作为辅助判断骨创伤患者病情轻重及预后的重要指标.     

Hypothermia produced in mice by histamine acting on the central nervous system

1. In mice 1-10 mug histamine injected intraventricularly produces hypothermia.2. This hypothermia was not antagonized by chlorcyclizine administered subcutaneously or intraventricularly, but chlorcyclizine injected intraventricularly was effective in antagonizing the hypothermia produced by a subcutaneous injection of histamine.3. Pretreatment with atropine was without effect on the hypothermia produced by an intraventricular injection of 10 mug histamine.4. Amphetamine and tranylcypromine not only effectively reduced the intensity of, or abolished, the hypothermia but also reversed the response to an intraventricular injection of 10 mug histamine so that hyperthermia was produced. Pargyline was without effect.5. Tolazoline strongly potentiated the hypothermia produced by the intraventricular injection of 10 mug histamine, but phentolamine did not.6. It is concluded that at least part of the hypothermia produced by a subcutaneous injection of histamine arises as a result of an action on the central nervous system.7. The possible mechanisms by which histamine acting on the central nervous system produces hypothermia and the suggestion that histamine may have a physiological role in thermoregulation are discussed in the light of these findings.     

FibroScan技术与乙肝肝硬化患者食管静脉曲张程度的相关性分析

目的：探讨瞬时弹性成像(FibroScan)与乙型肝炎(乙肝)肝硬化患者食管静脉曲张程度的相关性,以评价FibroScan对乙肝肝硬化患者食管静脉曲张程度的诊断价值。方法231例行胃镜检查的乙型肝炎肝硬化患者,应用FibroScan检测肝硬度值(LSM)得出轻、中、重度食管静脉曲张分别为119、31、81例,分别作为轻、中、重度食管静脉曲张组,同时检测相关生化指标。结果轻、中、重度食管静脉曲张患者的LSM平均值分别是(17.04±11.73)kPa、(22.63±18.70)kPa、(29.20±19.14)kPa。三组间比较差异有统计学意义(F=14.52, P<0.01);组间两两比较,轻、重度食管静脉曲张患者差异有统计学意义(P<0.01)。结论 FibroScan检测可以用来判断乙型肝炎肝硬化患者食管静脉曲张程度,值得临床推广应用。     

不同厂家替硝唑片含量及溶出度考察

目的对4个不同厂家替硝唑片进行质量考察.方法采用高效液相色谱法测定替硝唑片中替硝唑含量,转篮法结合紫外分光光度法测定替硝唑片溶出度.结果不同厂家替硝唑片含量、溶出度有统计学意义上的差异.结论 4个不同厂家替硝唑片含量、溶出度均符合质量标准.     

Effect of N-5' on histamine release from rat peritoneal exudate cells induced by calcium ionophore and ATP

We studied the effect of N-(3,4-dimethoxycinnamoyl)anthranilic acid (N-5'), an orally applicable anti-allergic drug, on the histamine release induced by calcium ionophores (A23187 and X537A) and ATP from rat peritoneal exudate cells (PEC). X537A (0.1-33.3 micrograms/ml) induced histamine release in a concentration-related manner, and 2.0 micrograms/ml of X537A induced release to the same extent as allergic histamine release. Histamine release induced by 2.0 micrograms/ml of X537A increased with longer incubation time, reaching a peak of about 100% at 120 min. N-5' had no effect on histamine release induced by X537A at the concentrations used (1-1000 microM), but DSCG exhibited significant inhibition at 1-100 microM. A23187 (0.05-0.5 microgram/ml) induced histamine release in a concentration-related manner, and it seemed that 0.033 microgram/ml of A23187 induces the same degree of histamine release as the allergic one. A23187 induced rapid histamine release which attained maximum 1 min after the addition. N-5' exhibited a significant concentration-dependent inhibitory effect on histamine release induced by A23187, and DSCG also exhibited significant inhibition (10 and 1000 microM). N-5' significantly inhibited histamine release induced by 100 microM ATP. These results indicate that N-5' and DSCG effect the histamine release induced by ionophore A23187 and X537A by different manners, and they suggest the possibility that N-5' inhibits some Ca++-dependent processes in histamine release, including the influx of Ca++ into cells, which is a trigger of the A23187 and ATP effects.     

The histamine content of oriental foods

Several of the symptoms of scombroid poisoning (i.e. histamine toxicity) resemble those observed in people suffering from Chinese restaurant syndrome. Therefore, the histamine content of representative Chinese cuisine, which included 31 common dishes, 12 condiments and 12 basic ingredients from several sources, was measured using a sensitive and specific radioenzymatic assay. A further enzymatic procedure involving diamine oxidase was used to verify that the substance measured was histamine. A total of 184 assays were performed on 57 samples in the study. High levels of histamine were found in the cheeses, which were used as positive controls (863.6 micrograms histamine/g blue cheese and 107.4 micrograms histamine/g Parmesan cheese), and in some common condiments, including tamari (2392.2 micrograms histamine/g sample) and one brand of soy sauce (220.4 micrograms histamine/g sample). The histamine content of four condiments and three common dishes was over 10 micrograms histamine/g sample, while four condiments and 16 common dishes contained less than 1 microgram histamine/g sample. Calculations involving representative amounts of food that can be consumed at a typical oriental meal suggest that, in some cases, histamine intake may approach toxic levels. The results are discussed with regard to the possible role of histamine in reactions associated with restaurant meals.