新型重组纤维蛋白原受体拮抗剂的表达、纯化及活性研究

目的:构建两个预期能够成为纤维蛋白原受体拮抗剂的重组融合蛋白.方法:人工合成北美水蛭素Decorsin的基因序列,利用基因工程的方法构建两个重组蛋白,分别是AnnV-D39:Annexin V加上Decorsin全序列和AnnV-D27:Annexin V加上Decorsin的羧基端27个氨基酸序列.在AnnV-D39的Annexin V和Decorsin序列之间加入了由10个氨基酸组成的连接肽GGGGSGGGGS.利用质粒pET-28(a )作为载体,将上述融合蛋白在大肠杆菌E.coli BL21(DE3)中以包涵体的形式进行高效表达,纯化后,进行抗血小板聚集活性测试.结果:基因表达的产物在变性条件下用DEAE-Cellulose52和SepharoseCL-4B层析纯化.随后进行的血小板聚集分析表明,AnnV-D39具有良好的抗血小板凝集活性,而AnnV-D27没有显示相似活性.结论:AnnV-D39作为一种新的纤维蛋白原受体抑制剂显示了良好的活性,而Annv-D27需要进行进一步的修饰.     

白细胞介素-1受体拮抗剂(IL-1ra)对大鼠佐剂性关节炎的影响

研究IL-1 ra（Interleukin-1 Receptor Antagonist）对大鼠佐剂性关节炎的治疗作用。采用SD大鼠作为受试动物，一侧足爪注射完全弗氏佐剂造成大鼠佐剂性关节炎（Adjuvant arthritis，AA）模型，检测足爪肿胀度、脾淋巴细胞增殖反应和腹腔巨噬细胞产生IL-1的水平。结果：IL-1 ra能明显减轻AA大鼠足肿胀程度；明显减少AA大鼠足爪评分分值；明显降低AA大鼠B淋巴细胞增殖反应和腹腔巨噬细胞IL-1的产生，可恢复降低的T淋巴细胞增殖反应。病理组织学观察结果表明，IL-1 ra可明显减轻AA大鼠关节中炎性细胞浸润、滑膜增生、血管翳形成、软骨和骨的破坏。IL-1 ra对AA有明显的治疗作用     

Ondansetron reduces mood disturbance among biologically predisposed, alcohol-dependent individuals

BACKGROUND: Early-onset alcoholics (EOA) differ from late-onset alcoholics (LOA) by developing problem drinking during youth, experiencing severe behavioral problems, having a familial disease history, and possessing a tendency toward subsyndromal mood disturbance, including symptoms of depression, anxiety, and hostility. Subsyndromal mood disturbance is, therefore, an important component of the early-onset syndrome and may be mediated by serotonin dysfunction. Therefore, the serotonin-3 antagonist ondansetron, which has been shown to be effective at improving drinking outcomes and promoting abstinence among EOA, presumably by ameliorating serotonin dysfunction, also may exert its beneficial effects by alleviating mood disturbance among EOA. METHODS: After one lead-in week of single-blind placebo administration, subjects underwent 11 weeks of double-blind outpatient treatment using a 2 x 4 factorial design that examined age of onset (EOA versus LOA) and medication dose (placebo, or ondansetron 1, 4, or 16 microg/kg twice daily) combined with weekly standardized group cognitive-behavioral therapy. The placebo lead-in week was used to adjust for study entrance effects but not for excluding subjects. Assessments of mood were performed by using the overall score and subscales of the Profile of Mood States both at screening and at weekly intervals during the study. RESULTS: Subsyndromal mood disturbance was shown to be an important component of early-onset alcoholism. Ondansetron (16 microg/kg twice daily) showed greater therapeutic efficacy at alleviating symptoms of overall mood disturbance, fatigue, vigor, confusion/bewilderment, and depression among EOA compared with LOA. EOA-associated improvements in mood disturbance seemed to be independent of drinking behavior. CONCLUSIONS: Ondansetron has been shown to be an effective treatment for early-onset alcoholism. Ondansetron's ability to improve symptoms of depression, anxiety, and hostility among EOA may make an additional contribution to its therapeutic effect. Mechanistic studies are needed to delineate more clearly the relationship between serotonin dysfunction and pathophysiology among various subtypes of alcohol-dependent individuals.     

Beta-endorphin modulation of lymphocyte proliferation: effects of ethanol

BACKGROUND: We have previously shown that alcohol suppresses the natural killer (NK) cell activity of splenic lymphocytes partly by reducing the secretion of opioid peptide beta-endorphin (beta-EP) and its positive influence on NK-cell cytolytic activity in rats. The inhibition of NK-cell cytolytic activity was also associated with a reduced number of NK cells after chronic ethanol administration. Hence, the possibility arises that chronic ethanol may alter NK cell proliferation, survival, or both. In this study, we investigated whether ethanol treatment for 1 to 4 weeks reduces the proliferation of other lymphocyte subsets and whether beta-EP regulates ethanol's effect on lymphocyte proliferation. METHODS: Male rats were ad libitum-fed rat chow, pair-fed with isocaloric liquid diet, or fed with ethanol-containing liquid diet for 1, 2, 3, or 4 weeks. Groups of these rats were infused with beta-EP with or without the delta-receptor antagonist naltrindol into the paraventricular nucleus of the hypothalamus. Splenocytes were isolated and used for flow cytometric analysis of the changes in the number of various lymphocyte subsets. Lymphocyte proliferation was determined by mitogen stimulation assays. RESULTS: Ethanol consumption resulted in a reduction of the number of CD161+ NK cells, CD3+ T lymphocytes, CD4+ T-helper cells, and CD8a+ cytotoxic T cells in a time-dependent fashion. Alcohol consumption also suppressed the proliferative response of lymphocyte subsets to concanavalin A, phytohemagglutinin, and lipopolysaccharide. Beta-EP promoted the lymphocytes' proliferative response to mitogens, whereas naltrindol blocked the effects of the opioid. Chronic alcohol consumption reduced the proliferative response of lymphocytes to beta-EP. CONCLUSIONS: These results suggest that chronic alcohol administration reduces immune function partly by decreasing the opioid-regulated mitogen-stimulated proliferation of lymphocyte subsets.     

A1 Adenosine receptors can occur manifesting two kinetic components of 8-cyclopentyl-1,3-[3H]dipropylxanthine ([3H]DPCPX) binding

The results described in this paper show, for the first time, that At adenosine receptors can have two kinetic components for the binding of the antagonist [³H]DPCPX. At low ionic strength ( 42mmo1/l), dissociation of [³H]DPCPX bound to A₁ receptors fitted better to a two kinetic components model than to a one kinetic component model. The kinetic constants were consistent with comparable Kd values for the two components of the antagonist binding, and therefore these two components cannot be distinguished by saturation isotherm analysis. Correspondence to: E.I. Canela at the above address     

蛙皮素及其样肽与肿瘤的关系

综述蛙皮素及其样肽与肿瘤之间的关系以及抗蛙皮素肿瘤治疗的研究进展.蛙皮素及其样肽作为自分泌或旁分泌生长因子刺激各种肿瘤细胞的增殖,这种作用是通过受体介导的,在许多肿瘤中均发现有蛙皮素及其受体的异常表达.因此蛙皮素已成为抗肿瘤治疗的一个有希望的靶点.     

Short-term changes in neck muscle and eye movement responses following unilateral vestibular neurectomy in the cat

The purpose of this study was to investigate changes in neck muscle and eye movement responses during the early stages of vestibular compensation (first 3 weeks after unilateral vestibular neurectomy, UVN). Electromyographic (EMG) activity from antagonist neck extensor (splenius capitis) and flexor (longus capitis) muscles and eye movements were recorded during sinusoidal visual and/or otolith vertical linear stimulations in the 0.05–1 Hz frequency range (corresponding acceleration range 0.003–1.16 g) in the head-fixed alert cat. Preoperative EMG activity from the splenius and longus capitis muscles showed a pattern of alternate activation of the antagonist neck muscles in all the cats. After UVN, two motor strategies were observed. For three of the seven cats, the temporal activation of the individual neck muscles was the same as that recorded before UVN. For the other four cats, UVN resulted in a pattern of coactivation of the flexor and extensor neck muscles because of a phase change of the splenius capitis. In both subgroups, the response patterns of the antagonist neck muscles were consistent for each cat independently of the experimental conditions, throughout the 3 weeks of testing. Cats displaying alternate activation of antagonist neck muscles showed an enhanced gain of the visually induced neck responses, particularly in the high range of stimulus frequency, and a gain decrease in the otolith-induced neck responses at the lowest frequency (0.25 Hz) only. By contrast, for cats with neck muscle coactivation, the gain of the visually induced neck responses was basically unaffected relative to preoperative values, whereas otolith-induced neck responses were considerably decreased in the whole range of stimulation. As concerns oculomotor responses, results in the two subgroups of cats were similar. The optokinetic responses were not affected by the vestibular lesion. On the contrary, otolith-induced eye responses showed a gain reduction and a phase lead. Deficits and short-term changes after UVN of otolith- and semicircular canal-evoked collic and ocular responses are compared. Received: 15 April 1997 / Accepted: 29 December 1997     

Foot equilibrium position controls partition of voluntary command to antagonists during foot oscillations

During low-frequency (<1.5 Hz) voluntary oscillations of the foot, placed on a rotating platform, onset of the Tibialis Anterior (TA) EMG paradoxically phase-lags the onset of dorsiflexion, suggesting that initial dorsiflexion is sustained by recoil of elastic structures that were stretched during plantarflexion. It is argued that the lag would disappear if the EMG onset were referred to the foot passive equilibrium position rather than to the movement onset. This hypothesis was tested in ten subjects who, after assessment of foot equilibrium position, voluntarily oscillated their foot at various frequencies (0.2–3 Hz) over three angular ranges: a mid range (foot crossing the equilibrium symmetrically), a high range (whole excursion above equilibrium) and a low range (whole excursion below equilibrium). In the mid range, phase relations were measured between the crossing of equilibrium position and the onset of the TA EMG during dorsiflexion or the onset of Soleus EMG during plantarflexion. In both cases, the paradoxical lag of EMG on movement was absent, phase curves started around zero and could be well fitted by a second order model. Phase curves with similar features were also obtained in the high and low ranges (no crossing of equilibrium) but correlating the onset of the EMG burst to the onset of the related movement. Altogether, these findings show that in all ranges of the joint excursion, the homology is between the EMG onset and the moment when the foot draws away from equilibrium. Based on the observed pattern of muscular activation, we suggest that voluntary foot oscillation in any movement range is sustained by one sinusoidal central command that, when equilibrium is crossed, is clipped in two half-waves reciprocally distributed to the couple of antagonist muscles. A simple neural circuit for this operation is proposed.     

生长抑素增强丙谷胺抑制裸鼠胃癌生长的实验研究

研究胃泌素受体拮抗剂——丙谷胺(PGL)对裸鼠胃癌的抑制作用,以及短期应用生长抑素(SST)能否增强PGL的作用。方法:建立胃癌细胞株MKN_(45)裸鼠移植瘤的动物模型。荷瘤裸鼠30只随机分成:对照组、PGL组(500mg/kg)、SST组(200μg/kg)和PGL SST组。观察PGL、SST及PGL SST对胃癌移植瘤的面积、重量、胃癌细胞DNA的影响及其副作用。结果:第16、28天时,PGL组和PGL SST组移植瘤的面积、重量均低于对照组,且此两组胃癌细胞DNA指数、平均DNA含量及S期细胞比例均较对照组为低,尤以PGL SST组更明显;各组胃、结肠及胰腺的重量均相近。结论:PGL能抑制裸鼠胃癌细胞株MKNe移植瘤的生长;短期应用SST能增强PGL的作用,且对其他脏器无明显副作用,为他们的临床应用于治疗胃癌提供了理论依据。     

Regional brain distribution of risperidone and its active metabolite 9-hydroxy-risperidone in the rat

Risperidone is a new benzisoxazole antipsychotic. 9-Hydroxy-risperidone is the major plasma metabolite of risperidone. The pharmacological properties of 9-hydroxy-risperidone were studied and appeared to be comparable to those of risperidone itself, both in respect of the profile of interactions with various neurotransmitters and its potency, activity, and onset and duration of action. The absorption, plasma levels and regional brain distribution of risperidone, metabolically formed 9-hydroxy-risperidone and total radioactivity were studied in the male Wistar rat after single subcutaneous administration of radiolabelled risperidone at 0.02 mg/kg. Concentrations were determined by HPLC separation, and off-line determination of the radioactivity with liquid scintillation counting. Risperidone was well absorbed. Maximum plasma concentrations were reached at 0.5–1 h after subcutaneous administration. Plasma concentrations of 9-hydroxy-risperidone were higher than those of risperidone from 2 h after dosing. In plasma, the apparent elimination half-life of risperidone was 1.0 h, and mean residence times were 1.5 h for risperidone and 2.5 h for its 9-hydroxy metabolite. Plasma levels of the radioactivity increased dose proportionally between 0.02 and 1.3 mg/kg. Risperidone was rapidly distributed to brain tissues. The elimination of the radioactivity from the frontal cortex and striatum—brain regions with high concentrations of 5-HT₂ or dopamine-D₂ receptors—became more gradual with decreasing dose levels. After a subcutaneous dose of 0.02 mg/kg, the ED₅₀ for central 5-HT₂ antagonism in male rats, half-lives in frontal cortex and striatum were 3–4 h for risperidone, whereas mean residence times were 4–6 h for risperidone and about 12 h for 9-hydroxy-risperidone. These half-lives and mean residence times were 3–5 times longer than in plasma and in cerebellum, a region with very low concentrations of 5-HT₂ and D₂ receptors. Frontal cortex and striatum to plasma concentration ratios increased during the experiment. The distribution of 9-hydroxy-risperidone to the different brain regions, including frontal cortex and striatum, was more limited than that of risperidone itself. This indicated that 9-hydroxy-risperidone contributes to the in vivo activity of risperidone, but to a smaller extent than would be predicted from plasma levels. AUCs of both active compounds in frontal cortex and striatum were 10–18 times higher than those in cerebellum. No retention of metabolites other than 9-hydroxy-risperidone was observed in any of the brain regions investigated.