狭胸天牛成虫下颚须和下唇须化感器研究

狭胸天牛Ｐｈｉｂｌｕｓａｎｔｅｎｎａｔｕａ（Ｇｙｌｌ．）成虫下颚须具有约１２０个栓锥感受器，分为３种类型。下唇须具有约１００个栓锥感受器，分为两种类型。下颚须和下唇须都有探测寄主植物、配偶和产卵场所的作用。     

两种组胺受体拮抗剂对内毒素作用下雏鸡体温的影响

为了研究组胺H1、H2受体拮抗剂对内毒素攻毒后雏鸡体温的影响,探讨内源性组胺在内毒素攻毒时导致雏鸡发热的作用机理。采用100羽雏鸡随机分5组,即模型组、扑尔敏组、西咪替丁组、扑和西联合组和空白组。空白组中午腹腔注射生理盐水,其余各组注射等剂量的LPS,早、晚肌注相应药物。实验持续15 d,分别于攻毒后0 d、5 d、10 d、15 d,各组随机抽10个样本。在注射LPS后0 h、2 h、4 h6、h,测定雏鸡直肠温度,结果:(1)急性实验中,扑尔敏组2 h、4 h体温显著降低(P<0.05);而西咪替丁组和扑和西联合组在2h时体温极显著降低(P<0.01)。(2)慢性实验中,0 d5、d体温无显著差异;10 d、15 d扑尔敏组体温显著降低(P<0.05);15 d扑尔敏组、扑和西联合组体温显著降低(P<0.05)。结果表明:在内毒素引起的炎症反应中,内源性组胺主要是通过H1受体介导体温升高。     

Design of new α-conotoxins: from computer modeling to synthesis of potent cholinergic compounds

A series of 14 new analogs of α-conotoxin PnIA Conus pennaceus was synthesized and tested for binding to the human α7 nicotinic acetylcholine receptor (nAChR) and acetylcholine-binding proteins (AChBP) Lymnaea stagnalis and Aplysia californica. Based on computer modeling and the X-ray structure of the A. californica AChBP complex with the PnIA[A10L, D14K] analog, single and multiple amino acid substitutions were introduced in α-conotoxin PnIA aimed at compounds of higher affinity and selectivity. Three analogs, PnIA[L5H], PnIA[A10L, D14K] and PnIA[L5R, A10L, D14R], have high affinities for AChBPs or α7 nAChR, as found in competition with radioiodinated α-bungarotoxin. That is why we prepared radioiodinated derivatives of these α-conotoxins, demonstrated their specific binding and found that among the tested synthetic analogs, most had almost 10-fold higher affinity in competition with radioactive α-conotoxins as compared to competition with radioactive α-bungarotoxin. Thus, radioiodinated α-conotoxins are a more sensitive tool for checking the activity of novel α-conotoxins and other compounds quickly dissociating from the receptor complexes.     

The Nemertine Toxin Anabaseine and Its Derivative DMXBA (GTS-21): Chemical and Pharmacological Properties

Nemertines are a phylum of carnivorous marine worms that possess a variety of alkaloidal, peptidic or proteinaceous toxins that serve as chemical defenses against potential predators. The hoplonemertines additionally envenomate their prey with a mixture of proboscis alkaloids delivered with the help of a calcareous stylet that punctures the skin of the victim. Anabaseine, the first of these alkaloids to be identified, stimulates a wide variety of animal nicotinic acetylcholine receptors (AChRs), especially the neuromuscular [e.g., α1₂β1γδ (embryogenic) or α1₂β1γɛ (adult)] and α7 AChRs that are inhibited by the snake peptide α-bungarotoxin. A synthetic derivative, 3-(2,4-Dimethoxybenzylidene)-Anabaseine (DMXBA; also called GTS-21), improves memory in experimental animals and humans and is currently in clinical trials to determine whether it can ameliorate cognitive problems associated with schizophrenia. Here we summarize present knowledge concerning the chemistry and mechanisms of action of these two substances (anabaseine and DMXBA) on AChRs, especially those found in the mammalian brain.     

东海秋带鱼聚集分布与水团的关系

带鱼Trichiurus lepturus Linnaeus是我国海洋渔业中主要的中下层经济鱼类之一,渔业生产产量居第一位。但在长期的渔业生产实践中。主要靠经验凭机会探索中心渔场。由于缺乏鱼类集群与分布规律的理论依据,渔汛预报也常常是困难的。因而,就鱼类的分布特点,聚集状态和规律进行探讨研究,在理论上和实践上都有重要意义。本文试图以统计分析的方法,对带鱼在秋汛的聚集分布类型与规律作初步的探讨,以求索科学合理和切合实际的渔场预报方法,井对一些渔业上常见的现象进行分析证明。 鱼类的集群,除水温以外.还受到其它诸如风情,盐度,潮汐等因子的制约。本文由于资料有限,仅就海洋中水温,水团分布与鱼类聚集、分布的关系进行初步分析探讨。更进一步地研究海况诸因子,找出它们与鱼类聚集之间有规律性关系,对我们的渔情预报无疑是有帮助的。     

Effects of betaine on expression of GFAP,glycine and glycine receptor in hippocampus of pentylenetetrazole-induced epileptic rats

AIM：To study the effects of betaine on glial fibrillary acidic protein (GFAP), glycine (Gly) and glycine receptor (GlyR) expression in the hippocampus of rats with epilepsy induced by pentylenetetrazole (PTZ). METHODS：Forty-eight healthy male Wistar rats were randomly divided into control group, PTZ (35 mg·kg-1·d-1, intraperitoneal injection) group, PTZ+betaine (450 mg·kg-1·d-1, intragastric administration) group, PTZ+betaine (225 mg·kg-1·d-1, intragastric administration) group, PTZ+betaine (112.5 mg·kg-1·d-1, intragastric administration) group and PTZ+sodium valproate (200 mg·kg-1·d-1, intragastric administration) group. The rats in control group were intraperitoneally injected with saline at the same volume as PTZ injection, and those in control group and PTZ group received intragastric administration of saline at 1.0 mL·d-1. Rat behavior was recorded. Serum homocysteine (Hcy) level was measured. The expression of GFAP in the hippocampus was measured by immunofluorescence. Hippocampal Gly content was measured by an amino acid analysis system. The expression of GlyR was detected by immunofluorescence and Western blotting. RESULTS：There was no difference in the latency of grand mal seizures among groups (P>0.05). However, betaine treatment significantly decreased the duration of the first grand mal seizure compared with PTZ group (P<0.01). Serum Hcy level in PTZ group was significantly lowered compared with control group (P<0.01), and further decreased after betaine treatment (P<0.05). GFAP in PTZ group was significantly higher than that in control group (P<0.01), and decreased after betaine treatment (P<0.05). Gly in PTZ group was significantly lowered compared with control group (P<0.01), and increased after betaine treatment (P<0.05). The content of GlyR among groups showed the same trend as Gly. CONCLUSION：Betaine treatment shows antiepileptic effect, which may be related to its effects on the metabolites of Hcy and Gly.     

Synthesis,Structural and Pharmacological Characterizations of CIC,a Novel α-Conotoxin with an Extended N-Terminal Tail

Cone snails are venomous marine predators that rely on fast-acting venom to subdue their prey and defend against aggressors. The conotoxins produced in the venom gland are small disulfide-rich peptides with high affinity and selectivity for their pharmacological targets. A dominant group comprises α-conotoxins, targeting nicotinic acetylcholine receptors. Here, we report on the synthesis, structure determination and biological activity of a novel α-conotoxin, CIC, found in the predatory venom of the piscivorous species Conus catus and its truncated mutant Δ-CIC. CIC is a 4/7 α-conotoxin with an unusual extended N-terminal tail. High-resolution NMR spectroscopy shows a major influence of the N-terminal tail on the apparent rigidity of the three-dimensional structure of CIC compared to the more flexible Δ-CIC. Surprisingly, this effect on the structure does not alter the biological activity, since both peptides selectively inhibit α3β2 and α6/α3β2β3 nAChRs with almost identical sub- to low micromolar inhibition constants. Our results suggest that the N-terminal part of α-conotoxins can accommodate chemical modifications without affecting their pharmacology.     

徐州市尾水导流及农业灌溉工程生态风险分析

徐州市尾水导流及农业灌溉工程投资大,涉及的区域广,影响因子多而复杂,势必对沿线的生态环境产生长远的影响。利用生态风险分析的基本原理和方法,研究了导流工程生态风险受体,并且对导流河渠水环境、尾水农业灌溉等进行了深入的生态风险分析。研究表明,导流线路占用原有河道,尾水流域面积扩大,尾水中部分内分泌干扰物等污染物可能会对流域水环境产生长期的潜在危害;尾水沿途用于农业灌溉,可能会对灌区土壤生态系统、地下水等造成不同程度的影响。     

Signals that stop the rot: Regulation of secondary metabolite defences in cereals

Plants accumulate a vast arsenal of chemically diverse secondary metabolites for defence against pathogens. This review will focus on the signal transduction and regulation of defence secondary metabolite production in five food security cereal crops: maize, rice, wheat, sorghum and oats. Recent research advances in this field have revealed novel processes and chemistry in these monocots that make this a rich field for future research.     

鱼类黑素皮质素受体(MCR)研究进展

 黑素皮质素受体(melanocortin receptor, MCR)家族属于最小的G蛋白偶联受体家族之一, 具有7个跨膜的α螺旋, 在脊索动物生理活动中具有重要作用。在哺乳类及四肢类动物的MCR研究中共发现有5种不同功能的同源基因(MC1R、MC2R、MC3R、MC4R、MC5R), 它们在机体色素沉积、摄食行为、能量平衡、类固醇合成和性行为等方面发挥重要功能。近年来, 鱼类MCRs的研究逐渐得到学者们的普遍关注, 一些鱼类的MCRs亚型相继被克隆, 并对其功能进行了分析。鱼类作为脊椎动物进化中较为原始的类群, 具有与哺乳动物MCRs相似的保守特征, 同时也具有其特殊性。对鱼类MCRs的深入研究有利于揭示MCRs在脊椎动物中的进化规律, 掌握MCRs对鱼类生理功能的调控特征, 为促进渔业生产提供科学理论基础。本文主要对近年来鱼类MCRs的克隆、分子特征、药理学及生物学功能等方面的研究进展进行简要的综述。