广龙昊膏药对大鼠腰椎间盘突出模型细胞因子IL-1、NO及组织胺的影响

为探讨IL-1、NO及组织胺在腰椎间盘突出中的作用及广龙昊膏药的治疗效果，将60只大鼠造模并随机分为正常组（A组）、造模组（B组）、广龙昊膏药组（C组）和奇正止痛膏组（D组），观察其神经根周围局部组织中IL-1、NO及组织胺的含量。结果显示，B组中的IL-1、NO及组织胺较A组显著升高（P〈0．01）。C组、D组较B组明显下降（P〈0．01）。表明大鼠腰椎间盘突出模型中细胞因子IL-1、NO及组织胺明显增加可能是腰椎间盘突出中的潜在始动或促进因素，而C组能显著降低神经根局部中IL-1、NO及组织胺的含量，说明广龙昊膏药作用部分是通过抑制炎性细胞因子的活性实现的。     

Improvement of endoneurial lipid abnormalities in experimental diabetic neuropathy by oxygen modification

Endoneurial hypoxia and a high frequency of closed capillaries have been found in chronic experimental diabetes and human diabetic sural nerve, respectively. These findings have led to the hypothesis that the pathogenesis of diabetic neuropathy is due to endoneurial hypoxia. To evaluate the role of endoneurial hypoxia in experimental diabetic neuropathy, the effects of supplementation and deprivation of oxygen on peripheral nerve lipid biosynthesis were studied in normal control and streptozotocin-induced diabetic rats. Defective lipid biosynthesis in diabetic nerve was partially prevented by oxygen supplementation. When normal rats were placed in a hypoxic chamber, lipid abnormalities similar to those observed in diabetic nerves were demonstrated in the absence of changes in nerve free sugars. These findings suggest that endoneurial hypoxia may underlie some key biochemical abnormalities encountered in experimental diabetic neuropathy.     

N-ω-Carbethoxypentyl-4-quinolones: A New Class of Leukotriene Biosynthesis Inhibitors

6-[(4-Quinolinyl)oxy]hexanoic acids and the corresponding esters were designed and synthesized as inhibitors of the production of arachidonic acid metabolites. The inhibitory activities were assayed in vitro by evaluation of serum leukotriene B₄ and thromboxane B₂ production. While all 6-[(4-quinolinyl)oxy]hexanoic acids and their esters proved to be inactive, the N-alkyl-4-quinolones, obtained as by-products in their synthesis, were found to be a new class of leukotriene biosynthesis inhibitors.     

Mutational specificity of the syn 1,2-dihydrodiol 3,4-epoxide of 5-methylchrysene

The mutational specificity of the syn dihydrodiol epoxide of 5-methylchrysene in the supF gene of the pSP189 vector was examined. Transversion mutations at GC pairs predominated with G → T and G → C changes accounting for 42 and 21% of total base change mutations. The types of mutations found reflect the previously determined chemical preference of this reactive species for reaction with deoxyguanosine residues in DNA.     

Integration of new regulatory strategies into the network of an endocrine control system: limitation of androgen secretion by rat testis is achieved by substrate-dependent modulation of P450XVII enzyme concentration and catalytic efficiency.

In addition to the well-known control circuits involved in the regulation and adaptation of testicular androgen biosynthesis, it is proposed that two new control strategies are involved in the maintenance of steady-state testosterone secretion rates by testicular Leydig cells. Cytochrome P450XVII (steroid-17 alpha-monooxygenase/steroid-17,20-lyase), one key enzyme in steroid hormone biosynthesis, responds to external human choriogonadotropin stimulation with an oxygen-dependent and substrate flux-dependent inactivation and decomposition, and increased substrate availability decreases the efficiency of androgen formation in favour of abortive intermediate leakage. These results are discussed as a paradigm of substrate-dependent modulation of cytochrome P450 activities.     

啤酒酵母在工业贮存期间的变化对生物合成1，6－二磷酸果糖的影响

随着工业贮存期的延长，啤酒酵母细胞的存活率及对葡萄糖连续磷酸化的速率迅速下降，１，６－二磷酸果糖在发酵液中的浓度由贮存前的７５ｇ／Ｌ降至贮存２个星期时的３０ｇ／Ｌ。