重组α_Ⅰb干扰素软膏对豚鼠皮肤疱疹病毒感染的作用

报道了重组α1b干扰素软膏对豚鼠皮肤单纯疱疹病毒感染的局部治疗的效果。目的是在疱疹病毒感染的动物模型上证实α1b干扰素软膏的治疗作用 ,为该药的临床应用提供临床前药效学资料。结果表明α1b干扰素软膏对疱疹病毒的皮肤感染具有缩短病程 ,促进结痂及痊愈的效果 ,可作为一种外用抗疱疹病毒药物应用于临床。     

生态系统服务价值评估研究进展——国外学者观点

生态系统服务的价值评估是目前生态学研究热点和存在较多争议的领域之一。争论的焦点主要集中在生态系统服务货币化评估的必要性和有效性。通过对大量文献的检索,较为系统地总结了国外学者的观点,特别是引起诸多争论的主要原因：一是由于生态系统本身的复杂性,各项服务之间存在着相互依赖的关系,使生态系统服务的分类本身就缺乏严格的标准,同时存在着时间和空间上复杂的尺度转换问题,从而使生态系统服务的价值评估容易出现重复计算;二是由于经济学方法本身存在着一定的局限性,对于不同的评估对象和评估目标往往需要选取不同的评估方法,每一种生态系统服务通常可以有几种不同的评估方法,评估结果在很大的程度上依赖于选择的不同方法．从而使得到的结果间缺乏可比性;三是由于生态系统不同于经济系统。有时用经济学方法对生态系统进行评估时往往很难反映出自然系统的价值,特别是当人类对生态系统服务的偏好随着时间和新信息的出现而发生变化时,可能会出现更大的差异。今后的研究应当着力于上述困难的解决,以便使生态系统的评估结果更加客观可信,为生态补偿机制建立和生态系统管理等提供有力支撑。     

城市建成区自生草本植物群落的物种多样性与功能多样性——以深圳市为例

城市自生草本植物的物种多样性和功能多样性直接影响城市生态系统的功能和稳定性,但目前相关研究依然很缺乏。以深圳市为例,基于建成区600个1hm²样地的现场调查数据,分析自生草本植物的群落结构、物种多样性、群落功能特征及功能多样性。结果显示:①调查共记录自生草本植物61科178属273种,其中多年生草本占54.6%,乡土植物占65.6%。②占明显优势的功能特征有中小型叶(91.85%)、草质叶(42.59%)、纸质叶(32.96%)、叶片无毛或近无毛(56.67%)、中等密度绒毛(40.37%)、叶面较粗糙(52.59%)、花期4-6个月(50.78%)、果期4-6个月(49.22%)、干果(86.03%)。③群落类型间功能丰富度FDp、功能离散度Rao二次熵差异极显著(P ＜ 0.01)、功能均匀度FEve差异显著(P ＜ 0.05)。④公园绿地的物种多样性指数明显高于其他三类绿地;不同绿地类型间的功能丰富度和功能离散度在滞尘、降噪、降温增湿及生物多样性保护方面都有极显著差异(P ＜ 0.01),功能均匀度只在滞尘及生物多样性保护方面差异极显著(P ＜ 0.01)。⑤各功能多样性指数均与Margalef指数、Simpson指数及Shannon-Wiener指数呈极显著正相关关系(P ＜ 0.01)。研究结论和方法为维护城市生态系统稳定性、建设生态宜居城市、促进城市可持续发展提供理论依据。     

The Influence of Arginine-specific Reagents on Nitrate Uptake by Corn Seedlings

The effects of three arginine-specific reagents on uptake were studied using corn seedlings (Zea mays L., GoldenCross Bantam). In the presence of borate, 0.25 mM 2, 3-butanedione(BD) and 1.0 mM 1, 2-cyclohexanedione (CHD) inhibited uptake by 76% and 68%, respectively, compared tothe controls. However, in the absence of borate, only 18% and38% inhibition was observed for 0.25 mM BD and 1.0 mM CHD, respectively.Similarly, 0.5 mM phenylglyoxal (PGO) resulted in 75% inhibition.The degree of inhibition of nitrate uptake exhibited a concentration-dependencewith respect to the reagents. Corn seedlings are 2- or 3-foldmore sensitive to BD than to PGO and CHD, respectively, presumablydue to the unfavourable steric effects of the benzal ring. Uptakeof was partially restored after removal of BD, CHD, and PGO from the uptake medium. No significant differenceswere observed for the ATPase and plasma membrane-associatedvanadate-sensitive H⁺-ATPase or K⁺-stimulated ATPase activityin homogenates and microsomal fractions prepared from corn seedlingswhich had been incubated for 2 h in the presence or absenceof 0.5 mM BD or 1.0 mM PGO. This suggests that inhibition ofnitrate uptake by the arginine-specific reagents was not causedby the indirect effect of their binding and inhibiting H⁺-ATPase.The fact that the arginine-specific reagents strongly inhibit uptake indicates that the transport system has arginine residues at or near the activesite. Key words: Arginine-specific reagents, borate effect, nitrate uptake, reversibility     

关于链格孢的毒性及其产毒条件的研究

本文报告了从食管癌高发区林县分离的具有强烈毒性和致突变性的链格孢(Alternariaalternata)“D_(10)-A_2”菌株粗提物半数致死量的测定,结果为71.25g 培养物/kg 体重;7个菌株粗提物的程序外 DNA 合成(UDS)试验,6个菌株粗提物的 DNA 合成抑制(DSI)试验。结果 UDS 试验6个菌株为阳性,DSI 试验5个菌株为阳性。说明互隔交链孢提取物可致人体细胞 DNA 的损伤。本文还报道了链格孢适宜的产毒条件。链格孢在一般粮食上均能生长繁殖产毒,适温为25℃,适宜的湿度根据粮食品种不同而为33—50％含水量。在北方侵染的主要粮食为小麦,当麦粒灌浆成熟期遇到较长时间的阴雨天气,或在收割脱粒时遇到连阴雨,麦粒被雨水浸泡。污染非发生于贮存期。     

Molecular Cascades in UV Induced Melanogenesis: A Central Role for Melanotropins?

When human skin is exposed to ultraviolet (UV) light, a highly complex cascade of events ensues that culminates, among other things, in increased skin melanin content. From analyses at the tissue and cellular level, it has been shown that following exposure to UV light there is an increase in the number of active melanocytes in the basal layer of the epidermis, and individual melanocytes are stimulated to produce more melanin. In addition, the rate of transfer of melanosomes from melanocytes to keratinocytes is apparently increased, although the role of UV light in this process remains to be demonstrated. Recent biochemical evidence is reviewed on factors that regulate these processes. A plausible explanation for the effects of UV on pigmentation is that there are mechanisms in the skin for the orderly, regulated reception of UV signals that are then transduced to initiate the cascade. The signals involve both melanocytes and keratinocytes, and avail-able evidence supports a model in which melanotropins and their receptors play a central role in the process.     

兴奋性氨基酸介导的膜电流可被吗啡阻断

在Ｓｐｒａｙｕｅ－Ｄａｗｉｅｙ大鼠的含有孤束核中央亚核及疑核神经元密集区的脑薄片上,吗啡（３—５ｐｍｏｌ）对疑核细胞内记录到的自发兴奋性突触后电位有抑制作用;向灌流液内注入吗啡可使电刺激孤束核在疑核记录到的兴奋性突触后电位的幅度降低７１．１±６．２％（Ｐ＜Ｏ．００１）,纳洛酮（５０ｎｍｏｌ／Ｌ）可翻转这种抑制效应;含有１０μｍｏｌ／Ｌ吗啡的灌流液对ＮＭＤＡ（０．５—１ｐｍｏｌ）、乙酰胆碱（３ｐｍｏｌ）及ＱＵｉｓｑｕａｌａｔｅ（０．１—０．５ｐｍｏｌ）引起的细胞膜去极化有不同程度的抑制作用,分别为３８．１±５．７％（Ｐ＜０．００１）,３２．８±５．５％（Ｐ＜０．０１）和２９．６±７．１％（Ｐ＜０．０５）。这些结果可能是由于吗啡兴奋μ和δ受体后,增加了Ｋ＋电流而降低Ｎａ＋,Ｃａ２＋离子通透性的缘故。     

Increment of hFIX expression with endogenous intron 1 in Vitro

This paper probes into the feasibility of increasing expression level of hFIX gene with endogenous intron 1 sequence.hFIX minigene was obtained with middle sequence truncated intron 1 inserted into the relative site of hFIX cDNA,and plasmid vector pKG5i‘IX,retroviral vector G1NaCi‘IX were constructed.These vectors were transduced into target cells of PA317,C2C12,primary rabbit skin fibroblasts (RSF) and primary human skin fibroblasts (HSF).The expression level of mixed colonies are PA317/pKG5i‘IX,151 ng/10^6 cells/24h;PA317/G1NaCi‘IX,308 ng/10^6 cells/24 h;C2C12/G1NaCi‘IX,186 ng/10^6 cells/24 h;RSF/G1NaCi‘IX,1929 ng/10^6 cells/24 h;HSF/G1NaCi‘IX,1646 ng/10^6 cells/24 h.These results indicated that hFIX minigene with intron l is able to increase the expression level to about 3 times of that of hFIX cDNA.Meanwhile,in order to study the application of hFIX minigene in the retroviral-mediated gene transfer system and refrain from intron splicing during viral production,a retroviral vector G1NaCi‘IXR with reversely inserted hFIX minigene expression cassette was constructed.The expression level of reverse constructor in PA317 cells was 390 ng/10^6 cells/24 h with 79% of bioactivity.PCR detection of HT/G1NaCi‘IXR cells infected with PA317/G1NaCi‘IXR supernatant confirmed the existence of intron 1 sequence.These results suggested that expression vector with forward-inserted intronl-carrying hFIX expression cassette can be used in directed gene transfer,but when using the retroviral-mediated gene transfer system,reversely-inserted intronl-carrying hFIX expression cassette should be considered.     

刺激交感神经对大鼠多觉型伤害性感受器诱发和自发放电的不同作用

多觉型伤害性感受器是皮肤内专一性较强的痛觉感受器。本实验用剥制神经细束的技术,引导大鼠尾神经C类纤维的传入放电反映多觉型伤害性感受器的活动,以判定刺激交感神经对外周痛觉感受过程的调制作用。测试了57个该类感受器的单位放电,发现下述两个主要事实:(1)刺激腰骶部交感干外周端,可以显著抑制伤害性刺激(包括机械压力,直流电-钾离子,热烫等)诱发的多觉型伤害性感受器的单位放电,其作用出现较快,可使放电数减少1/3左右,后作用延续十多分钟。局部动脉注射去甲肾上腺素也产生类似的抑制效应。从而证实交感神经具有抑制痛觉感受器的作用。(2)交感神经对部分多觉型伤害性感受器活动的调制具有双重作用的特点,即对同一单位因外加刺激引起的诱发放电有抑制作用,对其自发放电则有易化作用。讨论了交感神经这一双重作用的临床意义以及针刺通过交感神经调制外周痛觉感受过程的设想。