Predictive and prognostic biomarkers in colorectal cancer

Colorectal cancer is the third most common cancer and the second leading cause of cancer-related death in the United States.Three quarters of patients diagnosed with colorectal cancer will have early s...     

Molecular evolution of a long wavelength-sensitive opsin in mimetic Heliconius butterflies (Lepidoptera: Nymphalidae)

This study examines the pattern of opsin nucleotide and amino acid substitution among mimetic species 'rings' of Heliconius butterflies that are characterized by divergent wing colour patterns. A long wavelength opsin gene, OPS1 , was sequenced from each of seven species of Heliconius and one species of Dryas (Lepidoptera: Nymphalidae). A parsimony analysis of OPS1 nucleotide and amino acid sequences resulted in a phylogeny that was consistent with that presented by Brower & Egan in 1997, which was based on mitochondrial cytochrome oxidase I and II as well as nuclear wingless genes. Nodes in the OPS1 phylogeny were well supported by bootstrap analysis and decay indices. An analysis of specific sites within the gene indicates that the accumulation of amino acid substitutions has occurred independently of the morphological diversification of Heliconius wing colour patterns. Amino acid substitutions were examined with respect to their location within the opsin protein and their possible interactions with the chromophore and the G-protein. Of the 15 amino acid substitutions identified among the eight species, one nonconservative replacement (A226Q) was identified in a position that may be involved in binding with the G-protein.     

关于家蝇线粒体氧化磷酸化和亚显微结构的研究

本文报道有关家蝇胸肌线粒体氧化磷酸化作用和亚显微结构的实验和观察结果。试验证明,家蝇胸肌线粒体在离体条件下对`α``-甘油磷酸有很高的氧化和磷酸化活力,而对三羧酸循环各底物及其他氧化底物的氧化和磷酸化速率则极为微弱。胸肌匀浆以及线粒体与上清液的重组合试验结果和单独用分离的线粒体试验结果基本相同,从而有利于说明造成上述现象的原因可能不是由于线粒体在制备过程中受到损伤,而是家蝇胸肌线粒体膜对这些底物存在着特殊的透性屏障。在以`α``-甘油磷酸为氧化底物时,线粒体在下述保温条件下可获得很高的氧化速率和P/O比值:线粒体浓度较稀(2毫升反应液中含1—2毫克线粒体蛋白);保温时间较短(10—20分钟之内)以及外加一定量的牛血浆清蛋白(0.2%)。DDT对线粒体的氧化和磷酸化反应均表现强烈的抑制作用,但在正常家蝇和抗性家蝇中则表现出一定的差别。在离体试验的条件下,DDT(0.1m`M``)对正常家蝇线粒体的氧化抑制40%,对磷酸化抑制60.9%,而抗性家蝇则分别为23.4%和42.7%;在反应系统中外加牛血浆清蛋白时,DDT对正常家蝇线粒体的氧化抑制71.1%,磷酸化抑制94.8%,而抗性家蝇则分别为59.7%和87.1%。在DDT(5%)处理整体家蝇时,正常家蝇线粒体的氧化被抑制21%,磷酸化被抑制33%,而抗性家蝇则分别为11.5%和26.9%;在反应系统中外加牛血浆清蛋白时,DDT处理后的正常家蝇线粒体的氧化被抑制7.0%,磷酸化被抑制6.1%,而在抗性家蝇中则不表现任何抑制作用。电子显微镜的观察也证明,DDT处理后,正常家蝇线粒体的结构表现出明显的解体现象,但抗性家蝇线粒体仅在个别情况下表现为少数线粒体内膜的破坏,从而说明抗性家蝇线粒体在形态结构和生化功能两方面都表现出对DDT的一定程度的抗性。对本文的有关试验结果进行了讨论。     

A Check-List of the Species of the Genus Leucocytozoon (Apicomplexa,Plasmodiidae)*

SYNOPSIS. A list is given of 67 named species of Leucocytozoon considered valid at present. Another list is given of 1 reptilian and 146 avian hosts of named species of Leucocytozoon. A 3rd list is given of 34 synonyms. Leucocytozoon has been named from about 0.7% of the approximately 8600 species of birds that exist. The following new taxonomic names are included: L. danilewskyi var. hirundinis Sergent & Sergent, 1905 is emended to L. hirundinis; Saurocytozoon tupinambi Lainson & Shaw, 1969 is changed to Leucocytozoon (Saurocytozoon) tupinambi (Lainson & Shaw, 1969).     

腎上腺素和交感神經對貓胃分泌的作用

(一)靜脈注射腎上腺素對組織胺引起的貓胃分泌不論在急性或慢性實驗,通常是双相的,開頭抑制分泌,接着增加分泌,兩相大小相似,有時第二相還稍為大些。在一次注射0.02—0.1毫克腎上腺素之後,整個效應過程歷時約10—15分钟。若用較長的間隔如每10—30分鐘收集一次胃分泌,則此双相效應就會被掩蓋,因而得出腎上腺素對貓胃分泌無明顯效應或有增加分泌的效應的結論,如Baxter等人所得到的一樣。 (二)在急性實驗中,刺激大内臟神經對组織胺引起的貓胃分泌有顯著的抑制效應。与腎上腺素的效應不同,刺激大內臟神經的效應通常是單相的。我們在工作中经常得到馮德培所长的指导。谨致谢意.