Novel inhibitors of enkephalin-degrading enzymes. II: N5'-substituted-4-thioxohydantoic acids as aminopeptidase inhibitors

Some 2-substituted-(2'-aminophenyl)-4-thioxohydantoic acids (o-amino PTC-amino acids) have antinociceptive activity when administered (icv) alone (IC50 = 0.04-0.87 microM/animal) and show a striking prolongation of the antinociceptive action of (D-Ala-2 D-Leu5)-enkephalin (DADL) in combination. The effects are thought to be mediated via opioid receptors since they are naloxone-reversible. Although inhibitors of the enkephalin degrading puromycin-insensitive, bestatin-sensitive aminopeptidase (possibly aminopeptidase M) their action is weak (IC50 = 32 microM leucine, 536 microM, glycine) and they might be considered to have a direct antinociceptive effect on opioid receptors. The titled compounds constitute novel 'lead' compounds for the development of potent aminopeptidase M inhibitors.     

乌桕桕脂中甾醇和其它成分分离鉴定

通过柱层析、薄层层析等化学方法,从乌桕桕脂中分离得到甾醇及脂肪酸酯类化合物。经气相色谱和气-质联用分析,鉴定出下列化合物:β-谷甾醇、菜油甾醇、Δ~7-豆甾烯醇、肉豆蔻酸甲酯、肉豆蔻酸乙酯、棕榈酸甲酯、硬酯酸甲酯和硬酯酸乙酯。     

烧伤后大鼠肠道菌群的改变及其易位

本文报告了25％烧伤后注射免疫抑制剂(地寨米松磷酸钠)大鼠7种肠道细菌的定量、内脏及血液的细菌培养和肠壁的病理形态学改变。单纯烧伤组(B组)和单纯注射免疫抑制剂组(Ⅰ组)动物肠壁的病理改变较轻,肠道菌群改变不明显,其肠道细菌易位率也很低。烧伤后注射免疫抑制剂的动物(BⅠ组)肠壁病变严重,肠道菌群改变明显。其中,肠杆菌在回肠、盲肠,结肠内容物中的菌量均明显升高;回肠内容物中拟杆菌的菌量明显减少;该组动物肠道细菌易位率也明显增高,达60％。此外,BⅠ组、Ⅰ组部分动物发生了由棒状杆菌及由棒状扦菌和肠杆菌混合引起的内源性感染。根据不同肠段肠壁病变严重程度、菌群变化的部位以及不同部位肠管生理功能的不同,我们推测,回肠以上肠段是肠道细菌易位的主要部位。     

Vasoactive properties of dihomo-gamma-linolenic acid and series one prostaglandins in a freshwater teleost, Channa maculata

1. Prostaglandins A1, B1, E1 and F1 alpha (2-120 micrograms/kg), arachidonic acid and dihomo-gamma-linolenic acid (0.1-2 mg/kg) were injected intravenously into Channa maculata and changes in arterial blood pressure were recorded. 2. Injection of PGF1 alpha had no significant effect on arterial blood pressure. Injection of PGA1 and PGE1 was followed by dose-dependent hypotension whereas injection of PGB1 elicited significant dose-dependent increase in arterial blood pressure. 3. Both dihomo-gamma-linolenic acid and arachidonic acid were also depressor agents but dihomo-gamma-linolenic acid was more potent. 4. A single bolus intravenous injection of indomethacin (5 mg/kg) or 4 daily intraperitoneal injections (4 x 10 mg/kg) significantly lowered arterial blood pressure. One hour after pre-treatment of indomethacin, the vascular effects of both prostaglandin precursors were abolished. 5. It appears that the vascular effects of prostaglandins in Channa maculata are qualitatively different from those reported for mammals.     

Phosphorylation of the carotenoid droplet protein p57 by the catalytic subunit of cyclic adenosine monophosphate-dependent protein kinase and the effect of fluoride

We have previously shown that the dispersion and aggregation of carotenoid droplets in goldfish xanthophores are regulated, respectively, by phosphorylation and dephosphorylation of a carotenoid droplet protein p57. There is a basal level of p57 phosphorylation of p57 in unstimulated cells, which is greatly stimulated by adrenocorticotropic hormone (ACTH) or cyclic adenosine monophosphate (cAMP) acting via cAMP-dependent protein kinase. We have also observed that, in permeabilized xanthophores, pigment dispersion can be induced when cAMP is replaced by fluoride. Since p57 has multiple phosphorylation sites, there is the question of whether all p57 phosphorylation is by cAMP-dependent protein kinase or whether phosphorylation by cAMP-independent protein kinase coupled with inhibition of phosphatase activity by fluoride can replace cAMP-dependent protein kinase and that the ability of fluoride to replace cAMP for pigment dispersion in permeabilized cells is probably due to activation of adenylcyclase. We also show that ACTH causes an approximately threefold increase in the level of cAMP in these cells.     

Tolerance of tannin by the shiitake mushroom,Lentinus edodes

Summary Tannin at 1% (w/v) did not inhibit the growth ofLentinus edodes, but did inhibitPleuroius florida, P. sajor-caju, P. cystidosus, Agaricus bisporus andVolvariella volvacea. The inhibition was not due to its acidity.

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Tolérance de Lentinus edodes aux ajouts de tannin

Résumé Le tannin à la concentration de 1% (p/v) n'inhibe pas la croissance deLentinus edodes, mais inhibe celle dePleurotus florida, P. sajor-caju, P. cystidosus, Agaricus bisporus, etVolvariella volvacea. L'inhibition n'est pas due à son acidité.

     

The 25-kilodalton hemolytic protein affinity-purified from parasporal inclusions ofBacillus thuringiensis strain PG-14 (serotype 8a∶8b)

A simple method using an antibody-mediated affinity chromatography was developed for rapid and specific purification of the 25-kilodalton protein from alkali-solubilized and silkworm (Bombyx mori) larval gut juice-digested parasporal inclusions of theBacillus thuringiensis strain PG-14 (serotype 8a8b). Affinity-purified 25-kilodalton protein was highly hemolytic to red blood cells (RBCs) of two avian (chicken and goose) and six mammalian (horse, mouse, cow, rabbit, guinea pig, and sheep) species. The concentration of the 25-kolodalton protein required for 100% hemolysis was in the range of 2–16 g/ml, and an apparent RBC species-dependent variation was observed in hemolytic activity of this protein. Of the RBCs tested, chicken and house RBCs were the most susceptible to hemolysis by this protein; sheep RBCs wre 4–8 times less susceptible than the others.     

微孔草油中脂肪酸的分离和鉴定

微孔草[Microula sikkimensis(Clarke)Hemsl.]种子含油45%,其油中含有γ-亚麻酸,(顺式-6,9,12-十八碳三烯酸)8.1%。通过硝酸银硅胶柱层析和高压液相色谱分离,采用高碘酸钠、高锰酸钾氧化裂解的方法和红外光谱,紫外光谱,气相色谱分析,质谱分析,对油中的γ-亚麻酸,顺式-6,9,12,15-十八碳四烯酸,顺式-11-廿碳烯酸,顺式-13-廿二碳烯酸,顺式-15-廿四碳烯酸进行了分离、鉴定。