Daily changes in presynaptic cholinergic activity of rat sympathetic superior cervical ganglion

The in vitro capacity of sympathetic superior cervical ganglia (SCG) to take up [³H]choline from the extracellular medium, to synthesize acetylcholine from [³H]choline, and to release [³H]acetylcholine in response to a high K⁺ concentration, were examined in rats throughout a 24-h cycle. Both the release of [³H]acetylcholine and the synthesis of [³H]acetylcholine from [³H]choline exhibited significant diurnal variations, showing maxima during the first half of the night. After these maxima, nocturnal acetylcholine release and synthesis decayed to daytime levels and remained low until the end of the night. [³H]Choline uptake by rat SCG did not vary significantly throughout a 24-h period. A 1.5-h exposure of rats to darkness at the 5th hour of light phase of the daily photoperiod did not change significantly any parameter studied. A 20-min, 5-Hz, electrical stimulation of the preganglionic trunk of SCG excised from rats at noon increased significantly subsequent K⁺-induced [³H]acetylcholine release but did not change [³H]acetylcholine synthesis. In decentralized SCG of rats subjected to a unilateral SCG decentralization and a contralateral sham-operation 7 days earlier, [³H]acetylcholine release and synthesis were highly reduced or abolished at the decentralized side, while [³H]choline uptake remained unaltered. The present results suggest that an activation of preganglionic rat SCG neurons takes place during the first half of the scotophase.     

兔孤束核区微量注射γ-氨基丁酸的降压效应

在53只乌拉坦麻醉家兔身上,观察到延髓孤束核(NTS)区注射γ-氨基丁酸(GABA)使血压显著下降,安定(DZ)有相似的降压效应,荷包牡丹碱(BIC)和印防己毒素(PIC)则使血压升高;促甲状腺素释放激素(TRH)和甲硫脑啡肽(MTP)对血压无明显影响;延髓的另一些区域应用GABA等药物后血压变化不明显;提示GABA能神经递质系统参与心血管活动的抑制性中枢调节,NTS区是其作用部位之一。     

The Last 5 Years of Basic Science Investigation in Transplant Immunology

Many new insights have been gained over the past 5 years into the mechanisms that regulate immune reactivity to cell and organ transplants. This new knowledge is being applied to the development of innovative experimental strategies that may soon be evaluated in the clinic.     

血管细胞粘附分子调控造血的研究进展

本文简述了血管细胞粘附分子 (Vascularcelladhesionmolecule 1,VCAM 1)的结构和生物学功能 ,总结了VCAM 1在恶性血液病骨髓基质中的表达和意义 ,探讨了VCAM 1在造血干细胞动员和归巢中的作用 ,指出VCAM 1作用机制的深入研究将对恶性血液病的治疗提供更为有效的方法。     

Oral administration of an edible-mushroom-derived protein inhibits the development of food-allergic reactions in mice

BACKGROUND: Food allergy is a common disease without effective treatment. Since strict elimination of food allergens may be difficult, strategies for effective intervention are urgently needed. OBJECTIVE: The aim was to investigate the prophylactic use of orally administrated FIP-fve, an immunomodulatory protein isolated from the edible mushroom Flammulina velutipes, in a murine model of food allergy. METHODS: BALB/c mice were immunized twice intraperitoneally with ovalbumin (OVA), at an interval of 2 weeks. Before and during each period of immunization, FIP-fve (200 microg per mouse) or phosphate-buffered saline was given orally every other day with a total of five doses. Then OVA-specific antibodies and cytokine profiles were determined. Subsequently, the mice were orally challenged with OVA. Symptoms of anaphylaxis, levels of plasma histamine, and histology of intestines were examined. RESULTS: Mice receiving oral FIP-fve treatment during sensitization to OVA had an impaired OVA-specific IgE response with a Th1-predominant cytokine profile. These mice were protected from systemic anaphylaxis-like symptoms induced by subsequent oral challenge with OVA. CONCLUSION: Oral administration of FIP-fve has a Th1-skewing effect on the development of the allergen-specific immune response, and may serve the purpose of immunoprophylaxis for food allergy and other allergic diseases.     

Lack of effect of cimetidine on cigarette smoking

Summary The efficacy of cimetidine as a treatment that could reduce smoking in heavily dependent smokers has been determined. In a randomised, double-blind, double-crossover experiment, 43 heavy smokers were divided into two groups, one receiving cimetidine 400 mg orally three times a day, and the other receiving placebo for two weeks followed by the alternative treatment (placebo or cimetidine).No significant difference in the mean alveolar carbon monoxide, nicotine or cotinine levels was found between the two treatment groups compared to baseline. Since the alveolar carbon monoxide level reflects the intensity of smoking behaviour, the results suggest that no change in smoking behaviour occurred in the subjects.Contrary to our previous findings that cimetidine decreased the total body clearance of nicotine by 30% in a population of non-smokers, in the heavily dependent smokers, cimetidine did not appear to alter nicotine elimination. One possible explanation for the discrepancy is that tobacco smoking is known to induce nicotine metabolism and the induction might have offset any effect of cimetidine on nicotine elimination.Cimetidine does not appear to be a useful treatment leading to a reduction or cessation of cigarette smoking.