3种仙人掌多糖抗肿瘤作用的研究

研究3种仙人掌多糖对S180、H22荷瘤小鼠的抗肿瘤作用.通过腹腔注射给药,以抑瘤率、生命延长率及胸腺指数和脾指数为指标比较3种仙人掌多糖对荷瘤小鼠(S180和H22)的抑瘤作用.结果表明,3种多糖(食用仙人掌、药用仙人掌、仙人球)对S180荷瘤小鼠肿瘤有抑制作用,最大抑瘤率分别为46 38%,33 82%,36 23%;其对H22荷瘤小鼠有延长存活时间的作用,最大生命延长率分别为56 98%,45 53%,78 89%;另外,除药用仙人掌多糖低剂量组(50mg/kg)的胸腺指数及脾指数与生理盐水组无差异外(P>0 05),其他各多糖组的胸腺指数及脾指数均与生理盐水组及5-Fu组有显著差异(P<0 05,P<0 01).     

2012年秋季北京地区啮齿类实验动物健康状况的病理学调查和分析

随着现代科技的发展,实验动物在多方面起着越来越重要的作用。2012年10月,本实验室参与了北京市实验动物管理办公室组织的北京市啮齿类实验动物健康状况调查。采集心、肝、脾、肺、肾、大肠和小肠进行组织病理学观察,通过石蜡切片HE染色、冰冻切片油红O染色、PAS染色等方法对啮齿类实验动物的健康状况进行鉴定。结果显示,部分动物肝脏表现出不同程度的肝细胞肿胀、轻度肺脏病变,少数表现出肾脏管型、肾小囊腔蛋白样物质渗出和大肠寄生虫感染,但是啮齿类实验动物总体水平属健康状况。以上病变的出现可能与动物的生存环境、饲料营养成分和运输处死过程中的应激有关。     

有机硅改性酚醛树脂的研究

电导实验表明：有机硅的加入对合成的酚醛树脂的交联密度有影响.改性酚醛树脂的各项常规指标均优于普通酚醛树脂,其中残碳率可以达到50.75%,比普通酚醛树脂的残碳率（40.80%）提高了近10%.FESEM照片可以看到有机硅改性酚醛树脂在800℃碳化后生成了碳纤维,而且所生成半径大致为350～450 nm的SiO2粒子分布于酚醛树脂的碳化物中,分布较均匀且与基体的结合较好,有机-无机杂化改性有利于酚醛树脂力学性能的提高.     

树(鼠句)(Tupaia belangeri chinensis)消化器官和性腺LDH同工酶的电泳分析

采用0.5%琼脂糖凝胶电泳方法对云南树鼩的肝脏、胃、小肠、胰腺、睾丸和卵巢组织的乳酸脱氢酶同工酶进行电泳分析.结果表明,在6种不同组中,乳酸脱氢酶均呈现为5种不同分子形式的同工酶.其LDH_4至LDH_1同工酶随电泳迁移率的增大依次趋于阳极端,LDH_5同工酶则趋于阴极端.按分光光度比色定量法对各同工酶组分进行洗脱定量,分别测得6种组织中5种同工酶组分的相对百分含量.通过酶谱分析,提示在6种不同组织中由于A、B两种基因表达活性的差异,其酶谱特征也各不相同.文中对树鼩6种组织的LDH同工酶的H和M亚基百分率及H/M亚基比率进行了统计分析,提示这与各类组织的生物学功能及代谢类型相关.     

多效唑在冬小麦上的应用技术及对群体器官结构的影响

本研究通过用多效唑对冬小麦浸种和各时期不同浓度的叶面喷施证明,在冬小麦上拔节期前4—5天,喷施多效唑196ppm为最合适。并从群体器官结构水平揭示了多效唑的作用,表现在能增强植株的抗倒伏能力;提高叶片叶绿素含量及厚度;稳定后期叶面积;改善产量因素结构。增产率小区试验(对照倒伏情况下)30.75％,大区试验为10.7—11.9％。     

福宝山莼莱营养器官解剖研究

莼菜的不定根生于地下茎节的两侧，呈蔟生状。解剖结构与莲藕相似，具有发达的通气腔，无机械组织的分化，莼菜地下茎匍匐于泥中，粗壮、锈褐色，能迅速伸长生长；地上茎浮生水中，多分枝，细长，绿色；二者都具有发达的通气腔和双韧维管束；但后者在未成熟时，其表皮上被有腺毛，成熟的盾叶解剖构造与莲藕相似，但未成熟叶的解剖构造特殊，下表皮上有发达的腺毛，上表皮由二层细胞构成；叶肉细胞不分化，外韧维管束。     

Cell cycle changes after denervation of the newt limb regenerate,studied in vitro

Summary The proliferation of the mesenchyme of medium bud stage blastemas ofPleurodeles, measured by³H-thymidine incorporation and mitotic index, decreases about 40–50% under denervated conditions when cultivated in vitro for 4 days; epidermis is not affected in this case. Autoradiography of blastemas after³H-thymidine long term labeling shows that 3/4 of the mesenchymal cells and 1/4 of the epidermal cells are cycling when the blastema is innervated; there is no significant change of these percentages when the blastema is denervated. The results show, contrary to in vivo experiments, that denervation does not provoke an exiting from the cell-cycle but only lengthening of the cycle of the mesenchymal cells (probably of the G₁ phase).     

Effect of epidermal growth factor on growth and maturation of fetal and neonatal rat small intestine in organ culture

Summary Small intestinal explants from pre- and post-natal rats were incubated in an organ culture system in the absence and presence of epidermal growth factor (EGF). The rate of synthesis of small intestinal DNA and protein as well as the activity of lactase and alkaline phosphatase increased rapidly between 17 and 20-day gestational age, whereafter they declined. The maximal incorporation of³H-thymidine and¹⁴C-alanine into DNA and protein, respectively, was significantly stimulated by EGF (100 ng/ml). EGF had no effect on the activity of either lactase or alkaline phosphatase in the small intestinal explants.Acknowledgment. The project was supported by grants from the Veterans Administration Research Service. The authors wish to thank Dr. M. C. Geokas, Chief, Department of Medicine, Veterans Administration Medical Center, Martinez, CA, for providing us with excellent laboratory facilities and for his encouragement in this study.     

Maturation of the pineal melatonin rhythm in long- and short-day reared Djungarian hamsters

Summary Male Djungarian hamsters, reared under long (16L/8D) or short (10L/14D) days, were sacrificed at various ages during the day or night, or at night following a 30-min light pulse. The pineal melatonin rhythm matured similarly under long and short days by 20 days of age. The results are discussed in context of the hypothesis that melatonin mediates the photoperiod effects which forestall puberty in short-day reared hamsters.Supported by NIH research grant HD-05481.     

Neural systems underlying photoperiodic time measurement: A blueprint

Summary This paper briefly reviews the formal properties of the photoperiodic time measurement apparatus of mammals and presents a hypothetical model for the operation of the neural systems responsible for reading and responding to the nocturnal pineal melatonin signal. The primary melatonin readout mechanism is held to be common to all species responsive to melatonin. It seems likely that this mechanism responds to relative changes in the duration and amplitude of the melatonin signal, rather than the absolute levels of melatonin encountered. A series of neural systems which exploit the calendar information provided by the primary readout is envisaged to vary between and within species, depending upon the neuroendocrine response under consideration. Of particular importance is a mechanism for comparing the relative duration of successive melatonin signals. These more complex elements are responsible for phenomena such as the effects of photopheriodic history and photorefractoriness. The brain may be able to encode an accumulated memory of melatonin signals and thereby define longer term intervals within the annual cycle. A series of response elements within the hypothalamus are engaged by the appropriately processed photoperiodic stimuli. For all elements of this model, their anatomical representations are poorly understood or, in certain cases, completely unknown.