Polymerization of lactams, 92. Non-activated anionic polymerization of ϵ-caprolactam initiated with the sodium salt of ϵ-caprolactam

The non-activated polymerization of ε-caprolactam initiated with the sodium salt of ε-caprolactam (CLNa), which was prepared in situ with sodium methoxide, was studied in the temperature range 170–230°C and at CLNa concentrations from 0.20 to 1.0 mol-%, and at 190°C in the presence of 2.0–10.0 mol-% CLNa. Apparent rate constants and values of apparent activation energy (E_a) were determined for the initial autoaccelerated stage of polymerization (E_a = 230 kJ·mol^–1) as well as for the stage characterized by a zero-order reaction with respect to the monomer (E_a = 120 kJ·mol^–1). Non-integral orders of the polyreaction with respect to the initiator indicate a highly complex polymerization mechanism. Degradation reactions accompany the polymerization at high polymer contents.     

TightRope?

Surgical treatment of horizontally or vertically unstable acromioclavicular (AC) joint dislocations covers a wide range of surgical techniques, e.g. stabilization via a tension band, hooked tie plate or Bosworth screw. Many of these techniques are often accompanied by various complications so that a stabilizing, low complication and approximately physiological surgical treatment has moved increasingly into the focus of scientific interest. Through further development of the dynamic TightRope? system in syndesmosis surgery there is now the possibility to treat unstable AC joint dislocations in a similar manner. Advantages include improved cosmetic aspects through a less stressful surgical access as well as the reduction of postoperative infections and the fact that a second intervention to remove the metal implants is no longer necessary. Within the framework of biomechanical studies scientists were able to show that the TightRope? treatment was able to create a stable situation and to provide a sufficient load capacity.     

Mitigation of septic shock in mice and rhesus monkeys by human chorionic gonadotrophin-related oligopeptides

The marked improvement of several immune‐mediated inflammatory diseases during pregnancy has drawn attention to pregnancy hormones as potential therapeutics for such disorders. Low molecular weight fractions derived from the pregnancy hormone human chorionic gonadotrophin (hCG) have remarkable potent immunosuppressive effects in mouse models of diabetes and septic shock. Based on these data we have designed a set of oligopeptides related to the primary structure of hCG and tested these in models of septic shock in mice and rhesus monkeys. We demonstrate that mice exposed to lipopolysaccharide (LPS) and treated subsequently with selected tri‐, tetra‐, penta‐ and hepta‐meric oligopeptides (i.e. MTR, VVC, MTRV, LQGV, AQGV, VLPALP, VLPALPQ) are protected against fatal LPS‐induced septic shock. Moreover, administration of a cocktail of three selected oligopeptides (LQGV, AQGV and VLPALP) improved the pathological features markedly and nearly improved haemodynamic parameters associated with intravenous Escherichia coli‐induced septic shock in rhesus monkeys. These data indicate that the designed hCG‐related oligopeptides may present a potential treatment for the initial hyperdynamic phase of septic shock in humans.     

肿瘤化学治疗的研究Ⅱ硫氢及硫氢氨基已酸及其衍生物的抗肿瘤作用

氨基酸及多肽是蛋白质分子结构的基本组成部分,因此研究这类化合物的类似物及衍生物的化学合成与生理作用是有很大意义的。很多氨基酸及多肽的化合物都是具有特殊药理及化学治疗作用的药物。例如维生素中的叶酸及泛酸是麦麸酸及β-丙氨酸的衍生物,催产素及加压素都是结构比较复杂的环状多肽激素,而青霉素则可视为由β,β-二甲基半胱氨酸与N-酰基綠氨酸所组成的双肽,在其他抗菌素中放綫菌C是一类典型的具有抗癌作用的多肽抗菌素,近年来还发现了不