Mast cells in the pinna of Balb/c 'nude' (nu/nu) and heterozygotes (ny/+)mice.

The relative number of mast cells in the ear lobes' skin (pinna) of nude (athymic) nu/nu and normal (thymic) nu/+ heterozygotes of Balb/c mice was similar. The results obtained contradict some suggestions about the general influence of the thymus on the number of mast cells in the skin and suggest the existence of some local factor(s) in regulation of skin mast cell numbers.     

The effect of D-6-methyl-8-[β-isopropylaminoethyl] ergoline-I on the lactation in nursing rats

D-6-Methyl-8-[-isopropylaminoethyl] ergoline-I [VÚFB-10726], beginning from the dose of 0.05 mg/kg p.o., suppresses lactation through the inhibition of prolactin secretion in nursing rats.     

Effect of 723-1723-1723-1on ethanol withdrawal in mice

Summary ⁹ (10 mg/kg, i.p.) administered to mice immediately after withdrawal from a 3-day exposure to ethanol vapor was found to intensify withdrawal reactions. No effect was seen when ⁹ was administered chronically during the exposure to ethanol.     

南澳岛及其附近岛屿夏季鸟类的初步调查

作者一行于 2 0 0 1年夏季对南澳及其附近岛屿的鸟类资源状况进行了调查研究 .结果发现 ,南澳及其附近岛屿有鸟类 51种 ,隶属 1 3目 2 8科 ,其中雀形目 2 3种 ,占所发现种类的 45% ,非雀形目 2 8种 ,占 55% ;国家一、二级保护动物各一种 ,分别为 :白腹军舰鸟 (F regataandrewsi)和岩鹭 (Egretta sacra) .按鸟类的栖息和迁徙习惯划分 ,有海鸟 8种 ,湿地候鸟 2种 ,湿地留鸟 9种 ,陆地候鸟 4种 ,陆地留鸟 2 8种 .在所有鸟类中以褐翅燕鸥 (Sterna anae-thetus)为优势种 ,数量最大 ,分布最广 .     

海南岛万泉河口沉积环境演变

根据对柱样沉积物²¹⁰Pb定年及有机碳、硫和有机碳同位素含量分析, 研究万泉河口沉积环境演变. 硫和δ¹³C均自19世纪初期开始持续减少, 硫从1.92%逐渐减少到0.36%, δ¹³C从−20.63‰减少到−23.64‰. C/S比在20世纪之前一直很稳定, 处于0.47~0.80之间, 有机碳与硫呈正相关; 在此之后, C/S比急剧增加, 至表层为3.94, 硫的含量与有机碳的增加没有相关关系. 结果表明在19世纪之前万泉河口尚为开阔的海湾, 处于正常海洋环境,未形成被沙坝围封的泻湖, 海水能够直接出入. 19世纪初期开始, 随着玉带滩沙坝向北发育, 河口逐渐被围拦成泻湖型, 进入的海水量逐渐减少; 在19与20世纪之交, 水体已开始明显淡化, 发展成为今天近乎淡水的泻湖.     

高灵敏度离子分子的吸收光谱

介绍了光外差-磁旋转-速度调制吸收光谱技术对离子分子的研究,该技术综合了光外差光谱技术、磁旋转光谱技术和速度调制光谱技术三者的特点,形成可以对离子分子高灵敏度测量的光谱技术.该技术不仅保留了速度调制光谱技术对离子分子选择性探测的特点,避免了来自中性分子光谱线的干扰,同时利用光外差光谱技术降低来自光源的幅度涨落噪声,消除放电过程的干扰,再结合磁旋转光谱技术可以对顺磁性分子进行选择性测量以及进一步提高测量信噪比.介绍了光外差-磁旋转-速度调制光谱技术的基本原理、实验方案以及对N2+,CO+,H2O+等离子分子的测量研究结果.     

Differential effects of the serotonin receptors on cultured rat cerebral cortical neurons

Effects of serotonin (5-HT) on cerebral cortical neurons were examined by patch clamp techniques. 5-HT produced a variety of responses such as outward (19/73 patches/neurons), slow inward (15/73 patches/neurons), fast inward (8/73 patches/neurons), and mixed currents (initially fast inward deflection followed by an outward response: 2/73 patches/neurons), with a latency of 12 sec, 15 sec, 0 sec, and 0 sec respectively, at a holding potential of −60 mV in whole-cell patches. The fast inward currents were again evoked by a selective 5-HT3 receptor agonist, 1-(m-chlorophenyl)-biguanide hydrochloride (CPBG). In the cell-attached patch clamp configuration, 5-HT inside the patch pipette elicited single channel currents with slope conductances of 42 pS and 132 pS (4/42 patches/neurons). CPBG inside the patch pipette evoked inward single channel currents with a lower slope conductance of 41 pS (3/23 patches/neurons). In contrast, application of 5-HT or a 5-HT₂ receptor agonist, α-methyl-5-hydroxytryptamine-maleate, outside the patch pipette induced outward single channel currents with a major slope conductance of 140 pS (8/30 patches/neurons) or 135 pS (6/20 patches/neurons), respectively. These results indicate that the outward and fast inward currents may be mediated respectively by the 5-HT₂ receptor, which is coupled to a G-protein, and by the 5-HT₃ receptor, which contains the non-selective cation channel, and that the mixed type may be caused by both the 5-HT₂ and 5-HT₃ receptors. Received 27 September 1996; received after revision 4 November 1996; accepted 7 November 1996     

Effect of hydrogen peroxide on the binding of Merocyanine 540 to human erythrocytes

The fluorescent dye Merocyanine 540 (MC540) is often used as a probe to monitor the molecular packing of phospholipids in the outer leaflet of biomembranes. In a previous study we showed that the increased staining of erythrocytes with a perturbed membrane structure was mainly due to an increase in the fluorescence yield of cell-bound MC540, rather than to an increase of the number of bound molecules. Erythrocytes and ghosts exposed to continuous fluxes of H₂O₂ exhibited pronounced lipid peroxidation. Further, red blood cells subjected to this form of oxidative stress also showed increased staining with MC540. It appeared that this was caused by a strong increase in binding of MC540, together with a slight red shift of the fluorescence emission maximum and a small increase in the fluorescence yield of bound MC540. The changed MC540 binding characteristics were not observed when lipid peroxidation was suppressed by the presence of the antioxidant BHT in the incubation medium. However, open ghosts exposed to H₂O₂ showed no increase of MC540 binding, excluding a direct involvement of lipid peroxidation. Measurement of fluorescence emission spectra and gel filtration studies showed that MC540 can bind to H₂O₂-exposed hemoglobin. Experiments with erythrocytes lysed in hypotonic medium after exposure to H₂O₂ revealed that peroxidation of lipids with H₂O₂ induced a non-specific permeabilization of the plasma membrane to MC540, thereby allowing MC540 to bind to the oxidatively denatured, more hydrophobic hemoglobin. These results indicate that conclusions about packing of phospholipids in the outer leaflet of the membrane based on increased MC540-staining should be drawn with care. Received 27 September 1996; received after revision 5 November 1996; accepted 27 November 1996