Laetrile — An Overview

The original theory in the 1920s on the mode of action of Laetrile is described along with the research that followed in light of this theory. For over 40 years, studies were conducted, using test animals, in an attempt to substantiate the theory. All of these studies have shown Laetrile does not preferentially kill cancer cells. In spite of these studies, the misconception persists that Laetrile prevents and cures cancer. The legal and socioeconomic implications of Laetrile are examined and the role of health education in combating this problem is explored.     

Myco-protein —a new food

Until recently the main contribution of micro-organisms to the human diet has been through fermentation, which is the basis of many traditional foods and drinks. The successful production of myco-protein marks a new role in the diet for microfungi, and is a good example of the modern application of biotechnology to food production.     

新型糖肽类抗生素——达巴万星

随着广谱抗菌药物及免疫抑制剂的使用，人口老龄化社会现象，抗菌药物耐药问题日益严重。和抗菌药物耐药相比，研制一种新型的抗菌药物的速度远远落后于前者。耐药的革兰阳性（G+）球菌是导致临床抗感染治疗失败的主要原因之一。达巴万星(dalbavancin)为Vicuron Pharmaceuticals公司开发的一种新型半合成糖肽类抗生素，为替考拉宁类似物A40926的衍生物，其化学结构式见图1。目前已完成了Ⅲ期临床试验，它对各类临床常见G+菌具有高度抗菌活性。达巴万星具有和替考拉宁相似的分子结构，但羧基肽基团末端的酰胺基修饰提高了达巴万星对葡萄球菌属，特别是凝固酶阴性葡萄球菌的抗菌活性；而亲脂支链和二聚体的形成提高了达巴万星的组织穿透性和与细菌细胞膜的亲和力。和替考拉宁等糖肽类抗生素一样，达巴万星通过与细菌细胞壁肽聚糖上D 丙氨酰 丙氨酸末端特异性结合，抑制细菌细胞壁肽聚糖的延伸和交联，阻止细胞壁合成而发挥杀菌作用。