白花前胡中白花前胡甙和Pd-C-I的分离和鉴定

从白花前胡(Peucedanum,praeruptorum)根中分得7个化合物,经化学方法和光谱分析分别鉴定为Pd-C-I(I),白花前胡甙(II),香草酸(III),没食子酸(IV),nodakenin(V),rutarin(VI)和isorutarin(VII)。II为新化合物,其化学结构为4-O-β-D-吡喃葡萄糖基-3-甲氧基苯丙酮,命名为白花前胡甙。I为首次从白花前胡中分得的线型二氢吡喃香豆素类化合物,这对前胡属植物化学分类学有一定意义。还利用2DNMR纠正了文献中关于化合物I和VII的个别碳信号归属的错误。     

华北白前中的C21甾体类化合物

从华北白前(Cynanchum hancockianum)干燥根的乙醇提取物中分离鉴定了6个C₂₁甾体化合物,其中白前甙元C(glaucogenin C,Ⅰ),白薇甙A(cynatratoside A,Ⅱ),白前甙元A(glaucogenin A,Ⅲ),脱水何拉得甙元(anhydrohirundigenin,Ⅳ)为已知化合物;华北白前甙元B(hancogenin B,Ⅴ),华北白前甙A(hancoside A,Ⅵ)为新化合物。提出了变型C₂₁甾体甙元质谱的裂解规律。药理实验发现化合物Ⅱ具有一定的抗肿瘤活性,化合物Ⅵ具有一定的抗内毒素作用。     

Carcinoma of the breast: detection with MR imaging versus xeromammography

Detectability of breast cancer with magnetic resonance (MR) imaging versus xeromammography was quantitatively compared. MR images were obtained of breasts of 120 women who underwent xeromammography. T1 values were determined for masses larger than 2 cm. Cancer was histologically confirmed in 39 breasts and was considered excluded from 81 due to results of biopsy, cyst aspiration, or sonography or absence of change in xeromammographic findings over time. Images were blindly interpreted by three observers, and results were expressed as receiver operating characteristic curves. Detectability of breast cancer was substantially better with xeromammography than with MR imaging for all observers (P less than .03, 10(-6), and .001). On MR images, spiculation of a mass, distorted architecture, skin thickening, and nipple or skin retraction were specific but relatively insensitive indicators of cancer. Masses with smooth, distinct margins and signal intensity greater than that of fat on T2-weighted images were always benign. Other findings and T1 values were not diagnostically useful. The authors conclude that xeromammography is superior to MR imaging in detection of breast cancer.     

Suspected leaking abdominal aortic aneurysm: use of sonography in the emergency room

To determine the value of sonography in the emergent evaluation of suspected leaking abdominal aortic aneurysms, the authors examined 60 patients in the emergency department using sonography and a protocol involving advance radio notification from the ambulance; arrival of sonographic personnel and equipment in the triage room before patient arrival; and, during other triage activities, rapid sonographic evaluation of the aorta for aneurysm and of the paraaortic region for extraluminal blood. Sonographic findings were correlated with surgical results and clinical outcome. When performed under these circumstances, sonography was accurate in demonstrating presence or absence of aneurysm (98%), but its sensitivity for extraluminal blood was poor (4%). A combination of sonographic confirmation of aneurysm, abdominal pain, and unstable hemodynamic condition resulted in the correct decision to perform emergent surgery in 21 of 22 patients (95%). An abbreviated sonographic examination done in the emergency room can provide accurate, useful information about the presence of aneurysm; this procedure does not significantly delay triage of these patients.     

Therapy of NAFLD: insulin sensitizing agents

Insulin resistance is an integral part of the underlying pathophysiology in most patients with nonalcoholic fatty liver disease (NAFLD). Insulin-sensitizing agents are therefore likely to be of key importance in the treatment of this disorder, especially in the histologically more severe form known as nonalcoholic steatohepatitis. Here we have reviewed the current literature on the two major insulin-sensitizing agents that have been studied in patients with NAFLD: the thiazolidinediones (or PPAR-gamma agonists) and metformin, the only available biguanide. Thiazolidinedione administration in human NAFLD has been shown to decrease hepatic fat by several different global measures and to decrease evidence of cellular injury, but it has also been associated with increased peripheral fat and weight gain. In contrast, metformin has been shown to improve biochemical markers without weight gain, but with more variable improvement in histology. Neither agent has been FDA approved for treating NAFLD, but existing studies have provided much hope for incorporating these medications into NAFLD management strategies in selected patients.     

Therapy of NAFLD: antioxidants and cytoprotective agents

Lipid peroxidation and secondary cellular injury are the dominant mechanism in the transition from relatively stable hepatic steatosis to potentially progressive steatohepatitis in nonalcoholic fatty liver disease (NAFLD). Oxidation of excessive fatty acids generates free radicals (reactive oxygen species) that damage organelles and stimulate signaling pathways leading to fibrosis and cellular injury. Both antioxidant agents (by breaking the chain reaction of lipid peroxidation) and cytoprotective agents (by stabilizing cellular and organelle phospholipid membranes) may be effective agents in treating an active steatohepatitis through amelioration of the driving force and attenuation of the secondary effects. Here we have reviewed the existing studies on such therapies, including vitamin E, S-adenosylmethionine (SAMe), betaine, and ursodeoxycholic acid. Small trials suggest possible improvement in liver enzymes with the use of these agents in NAFLD. However, controlled studies have not uniformly demonstrated benefit from these agents when compared with control groups treated with diet and weight loss alone, and measurement of reliable histologic endpoints is limited. These agents may show benefit in NAFLD through future larger controlled studies. Particular promise may exist in the use of these agents in combination therapy with ones that target other aspects in the pathogenesis of NAFLD, such as insulin-sensitizing agents.     

DEATH AS A STIMULUS TO IMPROVING THE AFRICAN ENVIRONMENT FOR MORE HEALTHFUL LIVING

In D. Leviton's (1991) conception of horrendous death , a poorly managed environment can contribute to widespread mortality, and the deaths so caused can further create an environment for subsequent death. The African environment in particular is characterized by a number of "deathogenic" factors that must be understood and confronted by health educators committed to minimizing or eliminating the impact of horrendous death on the African continent. In this comment, the author argues that attention to characteristic but preventable forms of death in the African context can lead to greater public advocacy among African health educators, contributing to the physical and psychological wellbeing of the populations they serve.