Evolutionary trends of the mitochondrial lineage differentiation in species of genera Martes and Mustela

We compared partial sequences (402 bp) of the mitochondrial cytochrome b gene in 68 individuals of martens (Martes), weasels (Mustela) and their relatives from the Northern Hemisphere to identify the modes of geographic differentiation in each species. We then compared complete sequences (1140 bp) of the gene in 17 species of the family Mustelidae to know the spatial and temporal modes of speciation, constructing linearized trees with transversional substitutions for deeper lineage divergences and with transversions and transitions for younger lineages. Our data suggested that these lineages of Martes and Mustela differentiated in a stepwise fashion with five radiation stages from the generic divergences (stage I) to the intraspecific divergences (stage V), during the last 10 or 20 million years as the fossil evidence suggests. In the lineage of Martes, the first offshoots are of Martes flavigula, M. pennanti, and Gulo gulo (stage II), the second is M. foina (stage III), and the third are M. americana, M. martes, M. melampus, and M. zibellina (stage IV). The divergence of the lineages of Mustela is likely to have taken place concurrently with the radiations of the Martes. These divergence processes are attributable in part to the geographic allocation along the two continents, North America and Eurasia, as well as among peripheral insular domains, such as Taiwan and the Japanese Islands. In addition, the Eurasian continent itself was shown to have been involved in the species diversification in the martens and weasels.

Highly Functionalized Daphnane Diterpenoids from Trigonostemon thyrsoideum

Trigonothyrins A-C (1-3), which are highly functionalized daphnane diterpenoids, were isolated from the stems of Trigonostemon thyrsoideum. Compounds 1-3 represent the first examples of daphnanes with an oxygen-bridged four-membered-ring system, and a linkage mode of 12,13,14-orthoester. Compound 3 was observed to inhibit HIV-1 induced cytopathic effects. The EC50 value was 2.19 mu g/mL, and the therapeutic index (TI) was more than 90.

Q-switched and mode-locked diode-pumped Nd : GdVO4 laser with low temperature GaAs saturable absorber

Low temperature GaAs (LT-GaAs) was successfully grown at the temperature of 550 degrees C by metal organic vapor phase epitaxy on a semi-insular GaAs substrate. With such an absorber as well as an output coupler we obtain Q-switched mode-locked (QML) 1064 nm Nd:GdVO4 laser pumped by diode laser with high repetition rate, formed with a simple flat-flat cavity. The repetition rate of the Q-switched envelope increased from 100 to 660 kHz as the pump power increased from 2.28 to 7.29 W. The mode-locked pulses inside the Q-switched pulse envelope had a repetition rate of similar to 1.36 GHz. A maximum average output power of 953 mW was obtained. The dependence of the operational parameters on the pump power was also investigated experimentally. (C) 2005 Elsevier B.V. All rights reserved.

1. 快速扫视系统对瞳孔对光反射系统的调制作用2. 麻醉状态下纳洛酮对吗啡依赖大鼠的岛叶神经元的自发放的影响

一. 快速扫视系统对瞳孔对光反射系统的调制作用快速扫视系统是研究运动神经控制的一个很好的模型。瞳孔对光反射是由进入视网膜的光亮度的增加而引起的瞳孔的收缩。之前的实验研究表明这两个系统都是开放的系统。但是对快速扫视系统是否对瞳孔对光反射系统有调制作用并没有研究过。本实验研究了注视状态和快速扫视状态下的瞳孔对光反射的潜伏期和瞳孔直径的变化。结果显示在注视状态下的和出现快速扫视时瞳孔对光反射的潜伏期表现出显著不同。外展和内收会引起瞳孔对光反射的潜伏期和瞳孔相对收缩率不同变化。在出现外展运动时，瞳孔对光反射的潜伏期显著下降，而出现内收运动时，瞳孔对光反射的潜伏期表现出显著增加。而瞳孔相对收缩率在出现两种运动时与注视状态下相比也发生不同的变化：外展运动引起瞳孔对光反射的瞳孔相对收缩率的增加，而内收运动引起瞳孔相对收缩率的减少。尽管快速扫视本身会引起瞳孔的收缩，但是引起的瞳孔收缩的变化不等于在出现快速扫视时的瞳孔对光反射的瞳孔直径的变化，这个结果说明在出现快速扫视时的瞳孔对光反射的变化并不是来源于光效应和快速扫视效应的简单叠加。基于快速扫视出现时间的进一步分析说明在瞳孔对光反射周期内不同时间出现两种快速扫视引起的瞳孔对光反射的潜伏期和瞳孔相对收缩率的变化不同。这些结果说明两个系统是有相互作用的，快速扫视系统可以调节瞳孔对光反射系统。关键词：快速扫视 瞳孔对光反射 调制二. 麻醉状态下纳洛酮对吗啡依赖大鼠的岛叶神经元的自发放的影响药物成瘾是药物长期作用于脑而产生的一种慢性复吸性脑疾病。之前有研究表明岛叶参与成瘾的过程。本实验以CPP为检测手段，检测实验大鼠是否产生吗啡依赖(吗啡给药方式为隔天给药，腹腔注射(10mg/kg)，共三次。然后采用四合一电极对纳洛酮诱发戒断的麻醉大鼠的岛叶和体感皮层进行细胞外电生理记录。与对照组相比，在记录的神经元中，被激活的神经元的所占比例（71.43%）远远大于对照组。将对照组和实验组的发放显著增加的神经元在给药前后的相对平均发放进行比较，两组神经元发放增加并没有显著差异。采用卡方检验比较了对照组和实验组的发放模式，结果显示两组发放模式存在显著差异。说明岛叶参与的方式可能是有更多数目的神经元参与，而不是通过改变单个神经元的发放参与。这也在神经元水平上为岛叶参与成瘾过程提供了一个证据。

条件反射性免疫抑制及其脑机制的c-fos研究

To explore the neural mechanisms underlying conditioned immunomodulation, this study employed the classical taste aversion (CTA) behavioral paradigm to establish the conditioned humoral and cellular immunosuppression (CIS) in Wistar rats, by paring saccharin (CS) with intraperitoneal (i.p.) injection of an immunosuppressive drug cyclophophamide (UCS). C-fos immunohistochemistry method was used to observe the changes of the neuronal activities in the rat brain during the acquisition, expression and extinction of the conditioned immunosuppression (CIS). The followings are the main results: 1. Five days after one trial of CS-UCS paring, reexposure to CS alone significantly decreased the level of the anti-ovalbumin (OVA) IgG in the peripheral serum. Two trials of CS-UCS paring and three reexposures to CS not only resulted in further suppression of the primary immune response, but also reduced the numbers of peripheral lymphocytes and white blood cells. This finding indicates that CS can induce suppression of the immune function, and the magnitude of the effects is dependent on the intensity of training. 2. On day 5 following two trials of CS-UCS pairing, CS suppressed the spleen lymphocytes responsiveness to mitogens ConA, PHA and PWM, and decreased the numbers of peripheral lymphocytes and white blood cells. On day 15, only PHA induced lymphocyte proliferation was suppressed by CS. On day 30, presentation of CS did not have any effect on these immune parameters. These results suggest that the conditioned suppression of the cellular immune function can retain 5-15 days, and extinct after 30 days. 3. CTA was easily induced by one or two CS-UCS parings, and remained robust even after 30 days. These data demonstrate that CIS can be dissociated from CTA, and they may be mediated by different neural mechanisms. 4. Immunohistochemistry assays revealed a broad pattern of c-fos expression throughout the rat brain following the CS-UCS pairing and reexposure to CS, suggesting that many brain regions are involved in CIS. Some brain areas including the solitary tract nucleus (Sol), lateral parabrachial nucleus (LPB) and insular cortex (IC), showed high level c-fos expressions in response to both CS and UCS, suggesting that they may be involved in the transmission and integration of the CS and UCS signals in the brain. There were dense c-FOS positive neurons in the paraverntricular nucleus (PVN) and supraoptic nucleus (SO) of hypothalamus, subfornical organ (SFO) and area postrema (AP) etc. after two trials of CS-UCS paring and after the reexposure to CS 5 days later, but not in the first training and after the extinction of CIS (30 days later). The results reflect that these nuclei may have an important role in CIS expression, and may also response to the immunosuppression of UCS. The conditioned training and reexposure to CS 5 days later induced high level c-fos expression in the cingulate cortex (Cg), central amygdaloid nucleus (Ce), intermediate part of lateral septal nucleus (LSI) and ventrolateral parabrachial nucleus (VLPB) etc. But c-fos induction was not apparent when presenting CS 30 days later. These brain regions are mainly involved in CIS, and may be critical structures in the acquisition and expression of CIS. Some brain regions, including the frontal cortex (Fr), ventral orbital cortex (VO), IC, perirhinal cortex (PRh), LPB and the medial part of solitary nucleus (SolM), showed robust c-FOS expression following the conditioning training and reexposure to CS both on day 5 and day 30, suggesting that they are critically involved in CTA.