Metabolism of 3β-hydroxycholest-5-en-26-oic acid in hamsters

Summary Metabolism of 26-hydroxycholesterol to 3-hydroxychol-5-en-24-oic acid and other C24-bile acids has been expected to occur by way of 3-hydroxycholest-5-en-26-oic acid in studies in vitro. 3-Hydroxycholest-5-en-26-oic acid was infused intravenously into bile fistula hamsters and the following C24-bile acids were identified: 3-hydroxychol-5-en-24-oic acid, lithocholic acid, chenodeoxycholic acid, and a small amount of cholic acid.     

BP网络应用于黄河水质的预测研究

利用黄河兰州段水质指标浓度时间序列作为学习样本，选取了DO、COD、氨氮、重金属离子等l0项指标作为输出参数，运用人工神经网络BP模型中的Levenberg—Marguardt优化算法对学习样本优化建模，将优化好的网络的预测结果与实测结果进行了比较，表明BP网络可以很好地用于黄河水质指标值及水质类别的预测。     

Mutations in a human homologue of Drosophila crumbs cause retinitis pigmentosa (RP12).

Retinitis pigmentosa (RP) comprises a clinically and genetically heterogeneous group of diseases that afflicts approximately 1.5 million people worldwide. Affected individuals suffer from a progressive degeneration of the photoreceptors, eventually resulting in severe visual impairment. To isolate candidate genes for chorioretinal diseases, we cloned cDNAs specifically or preferentially expressed in the human retina and the retinal pigment epithelium (RPE) through a novel suppression subtractive hybridization (SSH) method. One of these cDNAs (RET3C11) mapped to chromosome 1q31-q32.1, a region harbouring a gene involved in a severe form of autosomal recessive RP characterized by a typical preservation of the para-arteriolar RPE (RP12; ref. 3). The full-length cDNA encodes an extracellular protein with 19 EGF-like domains, 3 laminin A G-like domains and a C-type lectin domain. This protein is homologous to the Drosophila melanogaster protein crumbs (CRB), and denoted CRB1 (crumbs homologue 1). In ten unrelated RP patients with preserved para-arteriolar RPE, we identified a homozygous AluY insertion disrupting the ORF, five homozygous missense mutations and four compound heterozygous mutations in CRB1. The similarity to CRB suggests a role for CRB1 in cell-cell interaction and possibly in the maintenance of cell polarity in the retina. The distinct RPE abnormalities observed in RP12 patients suggest that CRB1 mutations trigger a novel mechanism of photoreceptor degeneration.     

Gemini表面活性剂在气/液界面上的微区形貌随表面压的变化

测定了Gemini表面活性剂在pH值为10．86,NaBr浓度为1．0mol／L的溶液气／液界面上的表面压一分子面积的等温线。用自制的Brewster角显微镜(BAM)观察了由Gemini表面活性剂在界面上所形成单分子膜的微区形貌随表面压的变化。结果表明：当pH值为10．86时,Gemini表面活性剂在1．0mol／L NaBr溶液的气／液界面上生成了凝聚态的单分子膜;当表面压较低时,观察到在界面上形成了同心圆结构;随着表面压的增加,这些同心圆可发生聚并而形成多中心结构。     

石羊河流域空气传播孢粉的初步研究

为了确定风长距离搬运的孢粉对干旱区尾闾型湖泊沉积物孢粉谱的贡献率，对干旱区典型的小流域--石羊河流域空气中的孢粉进行了分析．石羊河流域云杉树盛花期时，3个样点8个空气样孢粉分析显示，空气样孢粉组合与取样点植被状况大致相当，孢粉组合的空间变化基本上受现代植被分布状况控制，影响空气样孢粉谱和孢粉浓度的因素主要是取样时间和地点．在一定的范围内，干旱区风搬运孢粉的能力很强，可大量地搬运孢粉；但风长距离搬运孢粉的能力有限，超过一定距离，风搬运的孢粉数量还是很小的，风搬运的流域上游森林带的孢粉对中下游地区空气样孢粉谱的贡献率很小．     

Integrative taxonomy of the gymnophthalmid lizard Neusticurus rudis Boulenger, 1900 identifies a new species in the eastern Pantepui region,north-eastern South America

ABSTRACT

The gymnophthalmid lizard genus Neusticurus Duméril and Bibron, 1839 currently contains six described species. One of them, Neusticurus rudis Boulenger, 1900 has a long history of taxonomic confusion, and uncertainty remains about the number of species involved under that name, especially in the Pantepui region. Our molecular phylogenetic (concatenation and species tree) and morphological (morphometrics, external and hemipenial morphology) analyses confirm Neusticurus rudis as a species complex with several candidate species in the eastern Pantepui region. Neusticurus rudis is here redescribed based on the re-examination of the holotype and 10 specimens from the vicinity of the type locality (ca. 15 km airline) in Guyana. The geographic distribution of N. rudis sensu stricto is restricted to east of the Venezuelan Gran Sabana, extending from the slopes of Mount Roraima in Venezuela through the slopes of Maringma-tepui and Wayalayeng to Mount Ayanganna in Guyana, between 678 and 1500 m elevation. Populations tentatively assigned to N. rudis also occur from Mount Wokomung in the Pakaraima Mountains of Guyana to the Iwokrama Forest Reserve in Guyana, between 159 and 1234 m elevation. A new Neusticurus species is described from the uplands and highlands of the eastern Pantepui region, west of the Venezuelan Gran Sabana in Brazil and Venezuela, between 900 and 2200 m elevation. Populations provisionally assigned to the new species were also found from the La Escalera region to Chivatón, the summit of Abakapá-tepui and the slopes and summit of Auyán-tepui, Venezuela, between 1100 and 2203 m elevation. Our results suggest the Gran Sabana as a possible recent biogeographical barrier for the genus in the region and indicate that tepui-summit Neusticurus populations derive from uplands populations that shifted their habitat preference.

www.zoobank.org/lsid:zoobank.org:pub:33DCF862-11CF-4FD0-B4D6-706E2C6A339E     

Impairment of growth and pancreatic hypertrophy in rats fed trypsin inhibitor from raw peanuts

Zusammenfassung Trypsinhemmende Präparate aus rohen Erdnüssen (Arachis hypogaea) wurden während 6 Wochen jungen Ratten verfüttert. Das normale Wachstum wurde verzögert und eine Hypertrophie des Pankreas mit gleichzeitiger Hyperplasie der serösen Drüsenzellen bewirkt. Hitzebehandelte Präparate hingegen waren wirkungslos.