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1.
本文观察了番茄叶水提物对小鼠的急性毒性及其对脂多糖诱导急性炎症模型大鼠的影响。采用经典的急性毒性试验方法,观察小鼠口服给予番茄叶水提物的死亡率,按寇氏法计算半数致死量(LD50)。50只SD大鼠随机分为正常组、模型组、阳性药泼尼松5 mg/kg组与番茄叶水提物3.19、1.59 g/kg组,连续给药10 d,每天一次。以腹腔注射脂多糖(LPS)建立急性炎症模型,ELISA法测定血清白细胞介素1(IL-1)、白细胞介素6(IL-6)、肿瘤坏死因子(TNF-α)。结果显示,番茄叶水提物单次灌胃给药的LD50为46.44g/kg,95%可信限为39.52~54.60 g/kg。3.19 g/kg番茄叶水提物可明显降低LPS诱导的急性炎症小鼠血清IL-1、IL-6和TNF-α水平。番茄叶水提物抑制LPS诱导急性炎症的作用机制可能与其降低血清炎症因子水平有关。  相似文献   

2.
本文以牛大力(Millettia speciosa Champ.)为对象,利用小鼠爬杆和负重游泳为实验模型,研究了其多糖的抗疲劳作用。实验随机将小鼠分为五组,分别为空白对照组、阳性药(人参蜂王浆,7 mL/kg)对照组、牛大力多糖低剂量组[212.5 mg/(kg·d)]、中剂量组[425 mg/(kg·d)]、高剂量组[850 mg/(kg·d)],灌胃给药14 d后,考察其对小鼠爬杆时间、负重游泳时间以及血乳酸(LD)、血乳酸脱氢酶(LD-H)、血中尿素氮(BUN)含量的影响。结果表明,牛大力多糖能延长小鼠爬杆时间,增加小鼠游泳耐力,降低LD、BUN的含量、提高血中LD-H含量。且中剂量的药效与阳性药对照组的基本相当。  相似文献   

3.
本文研究了沙棘籽渣水提物(Aqueous extract of seabuckthorn seed residues,ASSR)对正常及糖尿病小鼠血糖、血脂代谢的影响。首先采用ASSR灌胃昆明种小鼠的急性毒性试验评价了ASSR的安全性;继而以250mg/kg和500 mg/kg剂量的ASSR连续灌胃正常小鼠3周;以250、500和800 mg/kg剂量的ASSR连续灌胃Al-loxan诱导的糖尿病小鼠3周,监测血糖,测定体重、血清胰岛素、总胆固醇和甘油三酯水平。结果显示:ASSR的LD50大于9.8 g/kg体重;连续给药3周,ASSR对正常小鼠的血糖和血脂代谢没有明显影响,但能明显降低糖尿病小鼠的血清葡萄糖和甘油三酯水平。上述结果表明:ASSR的LD50大于5 g/kg体重,按WHO急性毒性分级标准属于实际无毒级,其在实验性1型糖尿病小鼠模型上具有降血糖和降甘油三酯活性。  相似文献   

4.
南瓜多糖的降血脂作用研究   总被引:4,自引:0,他引:4  
研究了南瓜多糖对正常小鼠和四氧嘧啶型糖尿病小鼠血脂的影响.对正常小鼠灌胃高低两个剂量(200、400mg/kg)的南瓜多糖水溶液;对建模成功的小鼠随机分为模型对照组、南瓜多糖组(400mg/kg的PP)和优降糖组(15mg/kg的优降糖),灌胃给药.对两种类型小鼠的处理均设立正常对照组,给予等体积的生理盐水,测定小鼠的TC、 TG、 LDL-C、 HDL-C的含量.结果表明高剂量的南瓜多糖对正常小鼠的降血脂效果优于低剂量;南瓜多糖使糖尿病小鼠的TC、 TG、 LDL-C显著降低,HDL-C极显著升高;并且南瓜多糖的降血脂效果与优降糖相比无显著差异.  相似文献   

5.
目的:考察满山红软胶囊的急性毒性反应。方法:本试验采用灌胃给药方法,测定小白鼠的LD50。结果:小白鼠的LD50为78.48g生药/kg,95%的可信限为74.47~82.30g生药/kg,约为临床拟用剂量的784.8倍。结论:满山红软胶囊具有较低的急性毒性。  相似文献   

6.
目的了解PLGA-奥沙利铂缓释微球和奥沙利铂小鼠皮下给药的急性毒性。方法采用Bliss法分别测定PLGA-奥沙利铂缓释微球和奥沙利铂小鼠皮下给药对动物的半数致死量(LD50)。结果PLGA-奥沙利铂缓释微球小鼠皮下给药时的LD50为660.90 mg/kg,奥沙利铂小鼠皮下给药时的LD50为15.24 mg/kg,相差达43.37倍。结论PLGA-奥沙利铂缓释微球能够显著降低药物对动物的急性毒性。  相似文献   

7.
目的:进行归辛胶囊急性毒性实验,对小鼠和大鼠可能产生的毒性反应及严重程度,确定无毒反应剂量,为拟定人用安全剂量提供参考。方法:依据《中药、天然药物急性毒性研究技术指导原则》进行急性毒性实验。取小鼠、大鼠各40只,随机分为空白、归辛胶囊低、中、高剂量4个组,每组10只,分别对小鼠、大鼠灌胃给药,给药后连续地观察14天,于给药第1、7、14天称量动物体重,并观察动物饮食、外观、行为、分泌物、排泄物、死亡情况及中毒情况,测定半数致死量(LD50);在药物毒性较低无法测出LD50时测定小鼠、大鼠的最大耐受量(MTD)。取小鼠、大鼠各40只,随机分为空白组和归辛胶囊高剂量组,每组20只,给药后连续观察14天测定最大耐受量(MTD),观察指标同测定LD50结果:实验动物未出现死亡无法测出LD50,继而测定MTD,小鼠为24.0g/kg,大鼠为16.0g/kg,各组动物主要脏器均未发现明显病理学改变。结论:归辛胶囊推荐临床日用剂量为0.09g/kg,按此剂量用药具有安全性。  相似文献   

8.
茯苓多糖对流感灭活疫苗的免疫增强作用   总被引:4,自引:0,他引:4  
探讨茯芩多糖作为流感病毒灭活疫苗佐剂的免疫增强作用.将不同剂量(200 μg或1000 μg)的茯苓多糖分别与低剂量(0.015 μg)或高剂量(1.5 μg)流感病毒(A/PR/8)灭活疫苗共同免疫小鼠,以相应剂量灭活疫苗的单独免疫组、灭活疫苗与氢氧化铝(100 μg)共同免疫组、PBS免疫组作为对照组.一次免疫后3周收集血清,ELISA检测血清中IgG、IgG1和IgG2a的抗体水平;并用致死量(40×LD<,50>)流感病毒(A/PR/8)攻击小鼠,通过观察小鼠的体重丢失率、肺部病毒量、存活率来反映佐剂的免疫增强效果和疫苗的保护作用.结果显示,茯苓多糖能显著增加血清抗体水平,并提高小鼠抗致死量流感病毒攻击的能力,其免疫增强效果与氢氧化铝相当.茯苓多糖可作为一种新型的流感病毒灭活疫苗的免疫佐剂.  相似文献   

9.
本文探讨了海带褐藻多糖硫酸酯(fucoidan from Laminaria japonica,FL)对腺嘌呤诱导的小鼠高尿酸血症的拮抗作用。首先利用腺嘌呤灌胃法建立高尿酸血症动物模型,再以不同剂量(0.100、0.150、0.200 g/kg)的海带褐藻多糖硫酸酯治疗4周,最后对小鼠血清尿酸、肌酐、肝脏匀浆液中腺苷脱氨酶(ADA)和黄嘌呤氧化酶(XOD)的活性及小鼠肾脏组织病理学变化进行检测(HE染色)。结果表明,与空白组相比,腺嘌呤能极显著升高小鼠血清尿酸、肌酐水平、肝脏XOD及ADA活性(P0.01)。与模型组相比,海带褐藻多糖硫酸酯各剂量均能极显著降低小鼠血清尿酸、肌酐水平、肝脏XOD及ADA活性(P0.01)。光镜观察结果显示,与模型组相比,海带褐藻多糖硫酸酯治疗组小鼠的肾损伤有一定程度恢复。综上所述,海带褐藻多糖硫酸酯对腺嘌呤诱导的小鼠高尿酸血症有一定程度的缓解作用。  相似文献   

10.
李佐刚  王晨  雷兰  战祥友 《生物技术》2004,14(Z1):19-20
目的为保证临床用药安全,对蛇毒纤溶酶进行毒理学研究.方法急性毒性实验小鼠iv给药后,统计LD50及死亡率.亚慢性毒理学实验小鼠ip给药,家兔iv给药,观察动物的一般状态、死亡率、肝功能及血常规.结果LD50为19.30±1.77u/10g,急性毒性实验中,小鼠死亡时间在24~48h.亚慢性毒理学实验动物各项指标均正常.结论蛇毒纤溶酶的临床用量是安全的.  相似文献   

11.
12.
Ectogenesis, or the use of an artificial womb to allow a foetus to develop, will likely become a reality within a few decades, and could significantly affect the abortion debate. We first examine the implications for Judith Jarvis Thomson’s violinist analogy, which argues for a woman’s right to withdraw life support from the foetus and so terminate her pregnancy, even if the foetus is granted full moral status. We show that on Thomson’s reasoning, there is no right to the death of the foetus, and abortion is not permissible if ectogenesis is available, provided it is safe and inexpensive. This raises the question of whether there are persuasive reasons for the right to the death of the foetus that could be exercised in the context of ectogenesis. Eric Mathison and Jeremy Davis have examined several arguments for this right, doubting that it exists, while Joona Räsänen has recently criticized their reasoning. We respond to Räsänen’s analysis, concluding that his arguments are unsuccessful, and that there is no right to the death of the foetus in these circumstances.  相似文献   

13.
On the diversity of the Cladocera in the tropics   总被引:20,自引:13,他引:7  
The mythical concept of an impoverished tropical cladoceran fauna is refuted. On a planetary scale, around half of the cladoceran species presently known occur exclusively in the tropics-subtropics, often with considerable restriction to particular geographical subzones. On a regional (political) scale, the situation is often unclear because of the continued fragmentary nature of studies, and because political units are not a good basis for biogeographical comparisons. At the finest level of resolution (lake-perlake comparisons), there appears to be an upper limit of c. 50 cladoceran species per individual lake. No significant difference between lakes in the temperate zone and in the tropics could be established here. Daphnia is largely absent from the tropics, but is replaced by more Sidids, Moinids, and Bosminids, such that the average cladoceran community in the limnetic zone of a tropical lake is not characterized by less species but rather by lower population densities. This, in turn, is considered a consequence of higher prevalent predation levels in the tropics.  相似文献   

14.
Summary A tubular network was found in the terminal endings of the visual receptor cells in the human, the monkey (Macaca mulatta), the cat and the dog. These tubules are arranged in close groups in the vicinity of the synaptic lamellae and the invaginated dendrites. According to the form, diameter, density of the tubules and to the consistence of the network formed by them one can distinguish at these places an initial type (type I), a transitory (type II) and a vesicular one (type III). In the the type III branching, bizarre forms are frequent. The diameter of all the tubules reaches 500–600 Å, their density and walls being the same as in the synaptic vesicles.Similar networks also occur in the axons of the visual receptor cells of the monkey.
Zusammenfassung In den Endigungen der Photorezeptorzellen von Mensch, Affe (Macaca mulatta), Katze und Hund kommen aus Tubuli bestehende Komplexe vor. Organellenartig in geschlossenen Gruppen angeordnet, liegen sie in Nähe der synaptischen Lamellen und der invaginierten Dendriten. An diesen Stellen kann man nach Form, Durchmesser, Dichte und Konsistenz der von den Tubuli gebildeten Komplexe drei Typen unterscheiden: 1. einen initialen (Typus I), 2. einen Übergangstypus (Typus II) und 3. einen vesiculären Typus (Typus III). In letzterem kommen häufig verzweigte, bizarre Formen vor. Der Durchmesser sämtlicher Tubuli erreicht 500–600 Å. Ihre Dichte und ihre Wand gleicht denen der synaptischen Vesikel.Ähnliche Komplexe fanden wir auch in den Axonen der Photorezeptorzellen vom Affen.
  相似文献   

15.
16.
Methods of amperometry and potentiometric titration were used to follow dark respiration (DR) and apparent photosynthesis (AP) in the fucoids Ascophyllum nodosum (L.) Le Jol, Fucus vesiculosus L., and F. serratus L. from the Barents Sea littoral by the end of the 40-day-long polar night. The macroalgae were shown to manifest species-specific low rates of photosynthesis and respiration. However, in spite of their low photosynthetic status due to the effects of subzero temperature and prolonged low or zero illumination, the macroalgae have been able to restore DR and AP to the initial level already by the day 9; the ability to restore AP depended on the level of illumination. The study of the changes in the carbonate–bicarbonate system in the light and darkness demonstrated that the macroalgae grown in darkness, in contrast to those grown in twilight, could absorb bicarbonate in darkness; however, they lost this capacity after two-day-long illumination at an irradiance of 7 mol/(m2 s). Bicarbonate uptake in darkness and the capacity to restore the systems of photosynthesis and respiration in fucoid cells are discussed in the context of algal energy metabolism under the polar night conditions.  相似文献   

17.
The voltage-gated potassium channel is currently one of the few membrane proteins where functional roles have been mapped onto specific segments of sequence. Although high-resolution structures of the transmembrane portions of three bacterial potassium channels, the tetramerization domain and the cytoplasmic ball are available, their relative spatial arrangement in mammalian channels remains a matter of ongoing debate. Cryo-electron microscopic images of the six transmembrane voltage-gated Kv channel have been reconstructed at up to 18 Å resolution, revealing that the T1 domain tetramerizes and is suspended below the transmembrane segments. However, the resolution of these images is insufficient to reveal the location of the third piece of the puzzle, the inactivating ball domain. We have used the aberrant interactions observed in a series of chimæric channels to establish that an assembled T1 domain restricts access to the cytoplasmic face of the channel, suggesting that the N-terminal ball and chain may be confined in the space between the T1 domain and the transmembrane portion of the channel.  相似文献   

18.
Summary According to light- and electron-microscopic observations the pineal organ of the 3-day-old chicken consists of a prominent end vesicle and a tapering parenchymal stalk. During this stage the pineal lumen is in open communication with the third ventricle. However, in the 40-day-old chicken, which still possesses a well-developed end vesicle, the proximal portion of the pineal stalk displays regressive changes leading to local fragmentation. At this stage the pineal stalk is reduced, and the pineal lumen is missing. In 1-year-old chickens the parenchyma of the proximal portion of the stalk is further diminished, and in 3-year-old domestic fowl is completely displaced by bundles of collagenous fibers, only some nerve fibers being present. This post-hatching pineal development may reflect the sequence of changes leading from pineal sense organs to pineal glands.This work was supported by a grant-in-aid for Scientific Research from the Ministry of Education, Science and Culture of Japan  相似文献   

19.
When constructing predictors on the basis of the linear model of time series of various indicators often the question arises on the dependence of forecasting accuracy and the changing prediction horizon. The dependency of the quadratic risk of the classical predictor and the time horizon is considered.  相似文献   

20.
基于吴征镒将中国全部种子植物3238个属的分布区划分为15个大类型和34个变型的基础上,简要地讨论了中国植物区系与其它地区区系的联系,以及它在被子植物起源方面的作用。主要论点如下:(1)与热带亚洲区系的联系。这种联系主要通过第7类型(热带亚洲分布)及其5个变型来体现的。本文列举了10个科,龙脑香料、狭义隐翼科、交让木科、五隔草科、五列木科、肉实树科、心翼果科、八宝树科、兰花蕉科和四数木科,来说明这  相似文献   

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