克服早胚发育阻断的兔输卵管因子“DPF-1”的初步研究

兔64 kDa输卵管蛋白(DPF-1)具克服小鼠早胚发育阻断的作用。进一步分析的结果表明DPF-1的等电点介于7.2-8.1;其合成与分泌对雌激素或孕激素无明显依赖性,能穿越透明带,紧密附着在早胚细胞膜周围。借助于Western blotting分析法,发现DPF-1的分布具组织专一性,仅存在于输卵管,而新西兰白兔子宫、卵巢、肝脏、心脏、肺、脾脏、骨骼肌、小肠和脑等组织中皆未发现;在所检测的小鼠和金黄田鼠输卵管中,也显示出DPF-1相关分子,小鼠的为71 kDa和32 kDa输卵管蛋白,金黄田鼠的为68 kDa和49 kDa输卵管蛋白。值得注意的是,以DPF-1主动免疫的雌性小鼠,经交配,输卵管中的44.8%早胚发育遭阻断,提示DPF-1在克服早胚发育阻断并实现由母型向合子型基因调控过渡的过程中可能起决定性作用。     

Protein farnesyltransferase in plants: molecular characterization and involvement in cell cycle control.

Farnesylation is required for membrane targeting, protein-protein interactions, and the biological activity of key regulatory proteins, such as Ras small GTPases and protein kinases in a wide range of eukaryotes. In this report, we describe the molecular identification of a plant protein farnesyltransferase (FTase) and evidence for its role in the control of the cell cycle in plants. A pea gene encoding a homolog of the FTase beta subunit was previously cloned using a polymerase chain reaction-based strategy. A similar approach was used to clone a pea gene encoding a homolog of the FTase alpha subunit. The biochemical function of the pea FTase homologs was demonstrated by the reconstitution of FTase enzyme activity using FTase fusion proteins coexpressed in Escherichia coll. RNA gel blot analyses showed that levels of FTase mRNAs are generally higher in tissues, such as those of nodules, that are active in cell division. The relationship of FTase to cell division was further analyzed during the growth of suspension-cultured tobacco BY-2 cells. A biphasic fluctuation of FTase enzyme activity preceded corresponding changes in mitotic activity at the early log phase of cell growth. Moreover, manumycin, a specific inhibitor of FTase, was effective in inhibiting mitosis and growth in these cells. Using synchronized BY-2 cells, manumycin completely blocked mitosis when added at the early S phase but not when added at the G2 phase. These data suggest that FTase is required for the plant cell cycle, perhaps by modulating the progression through the S phase and the transition from G1 to the S phase.     

河南舞阳大岗细石器地点发掘报告

本文记述的是河南省舞阳县大岗细石器地点第４层出土的石制品,它属于以楔状石核为特征的细石器技术传统,上覆的第３层属于新石器时代裴李岗文化晚期,它的发现对研究细石器技术传统的分布和发展,探讨中原细石器遗存与新石器时代早期文化的关系等都具有一定的意义。     

Greater capillary-fiber interface per fiber mitochondrial volume in skeletal muscles of old rats.

The objective was to examine whether muscle structural capacity for O2 flux (i.e., capillary-to-fiber surface ratio) relative to fiber mitochondrial volume deteriorates with the muscle atrophy of aging in predominantly slow- (soleus, S) and fast-twitch (extensor digitorum longus, EDL) muscles of old (24 mo) and very old (35 mo) F344BN rats compared with adult (12 mo old). Wet muscle mass decreased 29% (196 +/- 4 to 139 +/- 5 mg) in S and 22% (192 +/- 3 to 150 +/- 3 mg) in EDL between 12 and 35 mo of age, without decline in body mass. Capillary density increased 65% (1,387 +/- 54 to 2,291 +/- 238 mm(-2)) in S and 130% (964 +/- 95 to 2,216 +/- 311 mm(-2)) in EDL, because of the muscle fiber atrophy, whereas capillary per fiber number remained unchanged. Altered capillary geometry, i.e., lesser contribution of tortuosity and branching to capillary length, was found in S at 35 compared with 12 and 24 mo, and not in EDL. Accounting for capillary geometry revealed 55% (1,776 +/- 78 to 2,750 +/- 271 mm(-2)) and 113% (1,194 +/- 112 to 2,540 +/- 343 mm(-2)) increases in capillary length-to-fiber volume ratio between 12 and 35 mo of age in S and EDL, respectively. Fiber mitochondrial volume density was unchanged over the same period, causing mitochondrial volume per micrometer fiber length to decrease in proportion to the fiber atrophy in both muscles. As a result of the smaller fiber mitochondrial volume in the face of the unchanged capillary-to-fiber number ratio, capillary-to-fiber surface ratio relative to fiber mitochondrial volume not only did not deteriorate, but in fact increased twofold in both muscles between 12 and 35 mo of age, independent of their different fiber type.     

Validation of portable muscle tone measurement device for quantifying velocity-dependent properties in elbow spasticity.

The objective of this study is to develop a portable device for quantifying the velocity-dependent properties of spastic elbow muscles. Based on a motor-driven system, validation tests of the portable system such as accuracy and response of sensors were first examined. Furthermore, simulated modules (inertia, damper and spring) as well as elbow joints (15 control and 15 hemiplegic subjects) were manually stretched under four different frequencies (1/3, 1/2, 1 and 3/2 Hz) through 60 degrees range of motion. Joint resistance and displacement during sinusoidal stretch were collected for further analysis. Two quantitative parameters (i.e., viscous components under each frequency and averaged viscosity across four frequencies) were derived to estimate the velocity-dependent properties of elbow joint. Tests of simulated modules confirm the manual stretch protocol and data analysis are valid in estimating the velocity-dependent component during a sinusoidal stretch. Compared to normal control, viscous component in each stretch frequency and averaged viscosity were significantly higher in subjects with spasticity (P < 0.001). The viscous component and averaged viscosity were found highly correlated with the modified Ashworth scale. These findings suggest that measurements of viscous component and averaged viscosity during manual sinusoidal stretching using the portable device could be clinically useful in evaluating spasticity.     

土地利用变化情景下浑河-太子河流域的非点源污染模拟

近年来非点源污染已经成为水污染的主要来源,对非点源污染发生机理和控制方法的研究有着重要的科学和现实意义.为了研究不同土地利用方式对非点源污染的影响,本文基于土地利用变化模型CLUE-S模拟了城市规划、历史趋势和生态保护3个预案下浑河-太子河流域土地利用未来变化.应用SWAT模型对非点源污染进行了模拟研究,并结合实测数据对模拟结果进行了评价.结合两个模型研究了3个土地利用预案下非点源污染对土地利用和景观格局变化的响应.结果表明: SWAT模型在浑河-太子河流域模拟精度较高,该模型在研究区具有适用性.城市规划和历史趋势预案下非点源污染负荷不断增加,城市规划方案下最高,生态保护预案下非点源污染负荷呈不断下降趋势.不同土地利用和景观格局对非点源污染有一定的影响,科学合理的生态建设能够有效减少非点源污染负荷.研究结果可以为流域的非点源污染研究提供案例,为非点源污染防治和最佳管理措施的制定提供科学依据,为相关政策制定提供参考.     

Evaluation of flavonoids from <Emphasis Type="Italic">Zostera asiatica</Emphasis> as antioxidants and nitric oxide inhibitors

Zostera asiatica is one of the five members of the genus Zostera that can be found in Korea. Studies have reported the phytochemical properties and bioactivities of Zostera species. Current study focused on the antioxidant effects of Z. asiatica as a part of ongoing research for bioactive substances from marine resources. Results indicated that a crude extract of Z. asiatica not only scavenged on peroxynitrite in vitro and on intracellular reactive oxygen species (ROS) but also inhibited production of nitric oxide (NO). The crude extract was subjected to solvent fractionation for bioactivity-based separation using aforementioned three bioassay systems. From the active n-butanol fraction, two flavonoids were isolated and characterized as luteolin (1) and luteolin-3’-sulfate (2). Both flavonoids showed significant antioxidant effects. In conclusion, Z. asiatica was demonstrated to possess antioxidant effect partly attributed to isolated flavonoids, the first such effect reported from Z. asiatica, to the best of our knowledge.