Crystallization and preliminary X-ray analysis of an anti-insect toxin BmK I6 from Buthus martensii Karsch scorpion

An excitatory anti-insect toxin from BmK scorpion, named BmK I6, has been purified and crystallized recently. Two crystal forms have been obtained by using ammonium sulfate as precipitant at different pH, one of which is single crystal. Diffraction data have been collected for the single crystal on a Mar Research 345 Image Plate. The analyses of the data show that the crystal can diffract to 0.28 nm resolution and belongs to the space group C2 with unit cell parameters a = 4.65 nm, b = 8.52 nm, c = 3.26 nm, α = γ = 90° ,β = 110.5° . There are 2 molecules per asymmetric unit according to its unit cell volume and molecular weight.     

速生抗病火炬松Pinus taeda苗的磁化培育和早期筛选技术研究

研究表明,利用磁场处理火炬松种子能显著提高种子发芽率、苗木抗病性和促进苗高生长,并以浸种后的冷藏期处理效果最好;利用病原菌的毒素粗提液可进行抗病苗的早期筛选。     

豇豆边缘细胞对铝胁迫的响应

以豇豆为材料,采用悬空培养法,研究了豇豆边缘细胞发育的特性及铝毒对豇豆边缘细胞的影响．研究表明,豇豆边缘细胞的发育和初生根的发育几乎同步,在豇豆根长15mm时边缘细胞数目达到最大值,在根长1mm时根冠的果胶甲基酯酶（PME）活性达到最大．豇豆离体边缘细胞在含铝溶液中存活不到24h;而黏附于根尖的边缘细胞在同样浓度的铝溶液处理下,48h后还保持85％的存活率．在处理时间相同的条件下,不同浓度的铝溶液处理间豇豆PME的活性不存在明显的差异,说明PME的活性受铝的影响较少,而主要与边缘细胞的脱落有关．     

我国海水养殖贝类弧菌病研究进展

综述了弧菌的致病机理,对我国主要养殖贝类的危害以及对其检测方法的进展,提出了养殖贝类弧菌病的一系列防治措施,另外对贝类弧菌病的研究方向也进行了探讨和展望。     

Effect of mycotoxin (T-2 toxin) on catecholamine and Na+, K+-ATPase levels in rat epididymis

Summary The effect of mycotoxin (T-2 toxin) on catecholamines and Na⁺, K⁺-ATPase activities in rat epididymis has been evaluated. Dopamine and norepinephrine levels were significantly elevated in the caput and corpus regions whereas their levels remained unchanged in the caudal part of the epididymis. Na⁺, K⁺-ATPase activity was significantly increased in all the three regions of rat epididymis as a result of the toxin treatment. These changes may suggest an adverse effect on epididymal functions in rats.     

Use of aggregating cell cultures for toxicological studies

Summary Relatively simple techniques are now available which allow the preparation of large quantities of highly reproducible aggregate cultures from fetal rat brain or liver cells, and to grow them in a chemically defined medium. Since these cultures exhibit extensive histotypic cellular reorganization and maturation, they offer unique possibilities for developmental studies. Therefore, the purpose of the present study was to investigate the usefulness of these cultures in developmental toxicology. Aggregating brain cell cultures were exposed at different developmental stages to model drugs (i.e., antimitotic, neurotoxic, and teratogenic agents) and assayed for their responsiveness by measuring a set of biochemical parameters (i.e., total protein and DNA content, cell type-specific enzyme activities) which permit a monitoring of cellular growth and maturation. It was found that each test compound elicited a distinct, dose-dependent response pattern, which may ultimately serve to screen and classify toxic drugs by using mechanistic criteria. In addition, it could be shown that aggregating liver cell cultures are capable of toxic drug activation, and that they can be used in co-culture with brain cell aggregates, providing a potential model for complementary toxicological and metabolic studies.     

蛔虫病导致昏迷的诊治

通过两例蛔虫寄生于人体后导致昏迷的病例,探讨其机理主要是毒素作用于中枢神经系统.及时诊断与治疗,可获痊愈。     

Implications of toxins in the ecology and evolution of plant pathogenic microorganisms: Bacteria

This review attempts to rationalise what is known about bacterial phytotoxins and associate it with the ecology and possible evolution of the producing organisms. Study of non-toxin producing variants gives insight into the ecological role of the toxin. Elucidation of chemical structures of phytotoxins has shown that many exist as families of analogous compounds. Studies on the variation of chemical structures and how they are distributed across species and genera can lead to development of hypotheses on evolutionary relationships. Knowledge on biosynthetic pathways to tosins allows recognition of specific enzymatic steps involved in developing the characteristic features of the structures. Phytotoxins often have a potent biochemical activity, and in some cases the producing organism has associated mechanisms to prevent action of the toxin upon itself; in such cases toxigenesis is clearly not a chance event. The various aspects of bacterial toxigenesis indicate that bacterial phytotoxins are special secondary metabolic products that play beneficial roles to the producing organisms in their various ecological niches.     

A型肉毒毒素在上半面部除皱中的应用

使用A型肉毒毒素（Botulinum Toxin A,BTX-A）注射治疗上半面部皱纹144例，其中额纹57例，眉间纹29例，鼻背部皱纹14例，双侧鱼尾纹144例。其结果144例皱纹中显效144例占79．17％；满意23例占15．97％；失败7例占4．86％，总有效率为95．14％。无一例发生中毒、过敏、上睑下垂、复视、下睑外翻等严重并发症，证明了A型肉毒毒素注射治疗上半面部皱纹，安全快速、侵袭性小，临床效果优良。