‘Classical’ and ‘new’ diabetogens—comparison of their effects on isolated rat pancreatic islets in vitro

This study compares functional and morphological alterations caused by application of alloxan, streptozotocin, xanthine oxidase/hypoxanthine (generation of reactive oxygen species), or S-nitroso-N-acetyl-D,L-penicillamine (SNAP, liberation of nitric oxide) to isolated rat pancreatic islets in vitro. In perifusion experiments, membrane leakage—detected by non-stimulated insulin release—was found after application of all drugs, but showed a substance-specific time pattern. Twenty-four hours after application of the classical diabetogens (alloxan or streptozotocin), potassium chloride- and glucose-stimulated insulin secretion were markedly reduced, while a persistent reduction was observed neither after exposure to xanthine oxidase/hypoxanthine, nor to SNAP. Morphological analysis of the islets revealed that nearly all β-cells were destroyed following alloxan or streptozotocin treatment, while the majority of β-cells were configured regularly after application of xanthine oxidase/hypoxanthine or SNAP. Necrotic cells found after xanthine oxidase/hypoxanthine usually differed in morphology from those observed after application of the classical diabetogens. While the former cells were characterised by swollen nuclei, the latter had shrunken nuclei with irregular condensed chromatin. Apoptosis was found only following nitric oxide exposure. Due to these differences, it seems unlikely that alloxan, streptozotocin, xanthine oxidase/hypoxanthine, and nitric oxide have a common major feature in their toxic action. Received 16 September 1999; received after revision 15 November 1999; accepted 26 November 1999     

New species of Marionina (Oligochaeta: Enchytraeidae) from a wave-exposed rocky shore in SE Ireland

Marionina macgrathi sp. nov. and M. ulstrupae sp. nov. are described from rock crevices, animal mats and algal turf on a wave-exposed rocky shore at Carnsore Point, County Wexford. Both resemble M. appendiculata Nielsen and Christensen, 1959 in having sigmoid setae and lacking a muscular penial bulb, but differ in possessing seminal vesicles and larger sperm funnels. The new species differ from each other in characters of the sperm funnel, spermatheca, coelomocytes and clitellum. They are compared with material of M. appendiculata from three localities in Ireland and two in USA.     

油种以及微生物的降解作用对海水中石油烃风化模式的影响

在研究了海水中石油烃自然风化模式的基础上，以实验室模拟，研究了原油和燃料油自然风化速率的差异以及微生物含量对风化速率的影响，结果表明，原油的自然风化速率稍低于燃料油，尽管微生物含量增加使其对石油烃降解的绝对量明显增加，但对烃类被降解的百分率以及风化速率常数基本上没有影响。由于微生物的含量本身就是海水中石油烃含量的函数，因此石油烃的风化速率仅为油含量的函数，而与微生物的含量无关。     

Reclassification of Bracon mendocinus,a gall‐associated doryctine wasp,and description of a new closely related species of Allorhogas (Hymenoptera: Braconidae)

One of the first reported gall‐associated braconids, from 1910, Bracon mendocinus Kieffer and Jörgensen, is removed from the subfamily Braconinae and transferred to the doryctine genus Allorhogas, A. mendocinus (Kieffer and Jörgensen) comb. nov. A new species morphologically similar to A. mendocinus, A. joergenseni Martinez and Zaldivar‐Riverón sp. nov., is also described. Additionally a neotype is designated for B. mendocinus Kieffer and Jörgensen. We base our conclusions on the morphological examination of recently collected specimens from central Argentina associated with galls on Lycium chilense (Solanaceae), as well as on the DNA variation at 28S ribosomal RNA and cytochrome oxidase subunit I (COI) mitochondrial DNA genes.     

Description of two new species of Guernea (Crustacea,Amphipoda, Dexaminidae) from Japan,with tentative revision of subfamily Prophliantinae

Guernea minor sp. nov. and G. ezoensis sp. nov. are described from Japan. Based on these new species and the literature, a tentative revision of the subfamily Prophliantinae is proposed. The subgenus Prinassus of the genus Guernea is invalidated. The subgenus Haustoriopsis of the genus Guernea is re-elevated to a separate genus from Guernea. Dexaminoculus is transferred from Prophliantinae to Dexamininae.     

中国绳蚋一新种(双翅目:蚋科)(英文)

本文记述采自贵州省雷公山自然保护区的绳蚋一新种 ,即苗岭蚋 Simulium(Gomphostilbia) miaolingense sp.nov.该新种具有雄虫后足基跗节膨胀和蛹茧无前中突等合并特征 ,且其两性尾器构造特殊 ,包括雄性生殖腹板基侧突 ,中骨短宽 ;雌性生殖板肉缘分离而外展 ,生殖义突两后臂具骨化小侧突 ,可与其它近缘种相区别。模式标本存放于贵阳医学院。     

Ten new species of the subgenus Steganina (Diptera: Drosophilidae: Stegana) from southern China

Ten new species of the subgenus Stegana (Steganina) are described from southern to south-western China: S. (S.) convena sp. nov., S. (S.) cylindrica sp. nov., S. (S.) eurystoma sp. nov., S. (S.) hamata sp. nov., S. (S.) hirticeps sp. nov., S. (S.) latigena sp. nov., S. (S.) planiceps sp. nov., S. (S.) rhomboica sp. nov., S. (S.) setivena sp. nov. and S. (S.) sphaerica sp. nov. They cannot be placed under any established species groups. http://www.zoobank.org/urn:lsid:zoobank.org:pub:D4B6C5A7-3700-4B0C-8355-E4564C2A7296     

广西为害林木的阿异虫属1新种(虫目:异虫科)

记述阿异虫属１新种——黄色阿异虫Ａｒｕａｎｏｉｄｅａｆｌａｖｅｓｃｅｎｓｓｐ．ｎｏｖ．，对新种描述，与近缘种作了比较，并附主要特征图。模式标本保存于北京林业大学昆虫标本室。     

锦屏一二级水电站影响区的鱼类资源

研究了雅砻江下游锦屏一二级水电站影响区的鱼类资源组成，类型，利用现状，提出了合理利用与保护管理的建议，可供鱼类资源研究，渔业管理部门参考。