首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 640 毫秒
1.
Follow-up investigation of the blood sera from preparturient women and women with habitual abortions showed the presence of a factor which has an activating effect on smooth muscle preparations because it causes the release of prostaglandins. Gel-chromatographic counter flow separation and microelectrophoresis of the blood sera have shown that the isolated serum factor is a water soluble glycopeptide with a molecular weight of about 2000.  相似文献   

2.
Summary Follow-up investigation of the blood sera from preparturient women and women with habitual, abortions showed the presence of a factor which has an activating effect on smooth muscle preparations because it causes the release of prostaglandins. Gel-chromatographic counter flow separation and microelectrophoresis of the blood sera have shown that the isolated serum factor is a water soluble glycopeptide with a molecular weight of about 2000.  相似文献   

3.
Summary G. Mansfeld demonstrated that in the serum of overheated animals a substance (thermothyrine A) is present which, injected into normal animals, decreases O2-consumption. Serum of thyroidectomized animals has no effect.Dogs and rabbits were treated daily with 0.10 g per kg methylthiouracil during 4 weeks, and were than subjected for 5 hours to a temperature of 34–35° C which raised their body temperature by 0.5–1.5° C. 2.5 cm3 of serum obtained at the end of the 5 hours period failed to reduce O2-consumption of normal rats, while sera of untreated dogs and rabbits produced after similar exposure to high temperature a fall of O2-consumption by 14–48%. It is therefore evident that methylthiouracil not only inhibits the formation of thyroxine but of thermothyrine A as well.The fact that thermothyrine A contains no iodine proves conclusively that the action of thiouracil compounds cannot be exclusively an inhibition of iodinization.  相似文献   

4.
Summary By chromatographic method we have shown the existence of a complex system for galactose transfer from UDP-galactose and for nucleotide hydrolysis in urines from Balb/c YC8 and normal Balb/c mice. By action of sera from normal and ascitic mice as source of enzyme, we have been able to detect transfer for galactose in urines from ascitic mice and an important inhibitory effect of the nucleotide sugar hydrolysis by the sera with urines from normal mice.  相似文献   

5.
Summary Quantitative determination of bacteriolysis with different T1–7-phages confirms earlier observations that with substances inhibiting the action of T1-phage the normal respiratory metabolism of the protected bacteria is quantitatively restored in every detail.With T2-phage, showing a different respiratory course of bacteriolysis, no effect is obtained with the same substance, either on the respiration of the bacteria or on the typical course of respiration during bacteriolysis. The action of the phage inhibiting substance against T1-phage is therefore an effect of definite specificity.  相似文献   

6.
The antigens contained in a crude lipoprotein-lipase fraction from the Rabbit adipose tissue have no effect on Mice, even after daily injections for several months. But they induce an immune reaction in Sheep, allowing one to produce several immune sera with a high physiological activity, without any specific barrier between Rabbit and Mouse. After total absorption of these immune sera by normal Rabbit serum, the remaining antibodies have an activity against esterasic lipoproteins. Small doses of these antibodies induce in Mice marked hyperplastic and degenerative reactions of the adipose tissue and an extensive lysis of the pancreas. A correlative high lymphocytic activation, producing B and T immunoblasts, is induced.  相似文献   

7.
The aim of the paper is threefold. Its first aim is to defend Eric Watkins's claim that for Kant, a cause is not an event but a causal power: a power that is borne by a substance, and that, when active, brings about its effect, i.e. a change of the states of another substance, by generating a continuous flow of intermediate states of that substance. The second aim of the paper is to argue against Watkins that the Kantian concept of causal power is not the pre-critical concept of real ground but the category of causality, and that Kant holds with Hume that causal laws cannot be inferred non-inductively (that he accordingly has no intention to show in the Second analogy or elsewhere that events fall under causal laws). The third aim of the paper is to compare the Kantian position on causality with central tenets of contemporary powers ontology: it argues that unlike the variants endorsed by contemporary powers theorists, the Kantian variants of these tenets are resistant to objections that neo-Humeans raise to these tenets.  相似文献   

8.
Summary WhenNaegleria fowleri (Lee) was incubated in newborn calf and human serum an amebicidal effect was observed. Heat inactivation of both sera resulted in the recovery of viable amebae after incubation in these sera. Exogenous iron added to non-heat inactivated calf serum improved viability slightly but was without effect when added to human serum not heat inactivated. Exogenous iron greatly enhanced growth and/or viability in heat inactivated calf serum. Viability of amebae also was considerably enhanced in human serum which was heat inactivated when pH was lowered in conjunction with iron supplements.Appreciation is expressed to Dr Ronald R. Weik (Dept. Biochemistry, Louisiana State Univ., New Orleans, LA. 70119) and Dr David T. John (Dept. Microbiology, Medical College of Virginia, Richmond, VA. 23298) for providing theNaegleria fowleri (Lee) used in this investigation.  相似文献   

9.
Summary Extracts of lucerne with 0.1N HCl prepared and fractionated by the method ofAdler 16 give a filtrate which contains anantigonadal substance. This can be obtained from the extract after precipitation with lead acetate and evaporation. The residue after extraction with cold pyridin contains long needle-crystals insoluble in ethanol, methanol, ether and chloroform. A solution of these crystals injected into rats caused a decrease in weight of the seminal vesicles. In the mouse this substance is without effect.  相似文献   

10.
The circadian clock in the unicellular alga Gonyaulax polyedra is accelerated by a substance in extracts from the cells themselves. The extracts have been fractionated using the circadian rhythm of bioluminescence as bioassay. The active substance, termed gonyauline, has been isolated and characterized as a novel low molecular weight cyclopropanecarboxylic acid (S-methyl-cis-2-(methylthio) cyclopropanecarboxylic acid). Synthetic gonyauline has a similar shortening effect on the period of the circadian clock.  相似文献   

11.
Mice infected with non-capsulated Staphylococcus aureus strains highly resistant to methicillin survived after the administration of specific immunoglobulin extracted from pooled human sera by using homologous capsular type strains, but no protective effect was shown with a conventional immunoglobulin preparation and methicillin, even with high doses.  相似文献   

12.
In the cycling female Rat, administration of substance P antisera performed at noon on the proestrous day provokes a significant increase in LH and FSH serum level, right before or after the preovulatory surges, but had no effect on its occurrence or magnitude. These results suggest that substance P has a normal physiological inhibitory role in gonadotropin regulation.  相似文献   

13.
Using anterior pituitary cells cultured for 7 days and then incubated for 4 hrs, substance P, an undecapeptide, inhibited the stimulatory effect of LH-RH on the release of LH-RH on the release of LH and FSH. This inhibitory effect, which was similar for both gonadotropins was only observed when the adenopituitary cells were put in culture at DI and Proestrus stages of the oestrous cycle. Furthermore substance P partly inhibited the basal release of FSH at DI and DII stages but did never affected that of LH.  相似文献   

14.
Summary Mice infected with non-capsulatedStaphylococcus aureus strains highly resistant to methicillin survived after the administration of specific immunoglobulin extracted from pooled human sera by using homologous capsular type strains, but no protective effect was shown with a conventional immunoglobulin preparation and methicillin, even with high doses.  相似文献   

15.
Summary The circadian clock in the unicellular algaGonyaulax polyedra is accelerated by a substance in extracts from the cells themselves. The extracts have been fractionated using the circadian rhythm of bioluminescence as bioassay. The active substance, termed gonyauline, has been isolated and characterized as a novel low molecular weight cyclopropanecarboxylic acid (S-methyl-cis-2-(methylthio) cyclopropanecarboxylic acid). Synthetic gonyauline has a similar shortening effect on the period of the circadian clock.  相似文献   

16.
Summary It has been demonstrated that terpinenol-4, contained in juniper-berry oil, has a marked diuretic effect. On the basis of this finding, it is assumed that this substance is the proper diuretic factor of juniper-berries.  相似文献   

17.
目的观察手性旋光异构体德氮吡格(TNBG)对6株人体肿瘤细胞增殖的影响,初步探讨其抗肿瘤作用机制。方法运用MTT法检测手性TNBG对6株肿瘤细胞生长抑制情况;油红O染色法观察QGY-7701细胞中脂质聚集情况;流式细胞仪检测手性TNBG对人肝癌细胞株QGY-7701细胞周期分布和凋亡影响。结果手性TNBG能不同程度抑制肿瘤细胞增殖,且呈剂量依赖性;油红O染色提取显示QGY-7701细胞内脂质量与给药剂量呈正相关;流式细胞仪检测到有s期细胞增加,并且手性TNBG还能诱导QGY-7701细胞发生凋亡。结论手性TNBG在体外具有良好的抗肿瘤活性,其抗肿瘤作用机制可能是通过促使肿瘤细胞产生脂质聚集,抑制肿瘤细胞增殖、诱导其凋亡从而达到抗肿瘤效应。总体看(+)TNBG体外抗肿瘤活性比(-)TNBG更强。  相似文献   

18.
The basis of peripheral blood lymphopenia observed in patients with chronic alcoholism and liver disease was investigated by examining the effect of sera of these patients on in vitro transformation of normal human peripheral blood lymphocytes. A positive correlation was demonstrated between the serum inhibition of phytohaemagglutinin- and pokeweed mitogen-induced transformation and the degree of lymphopenia. Thus serum factors may contribute to the observed lymphopenia by inhibiting lymphocyte production in vivo.  相似文献   

19.
In this paper I take a close look at the SI base quantity “amount of substance”, and its unit, the mole. The mole was introduced as a base unit in the SI in 1971, and there is currently a proposal to change its definition. The current definition of the mole shows a certain ambiguity regarding the nature of the quantity “amount of substance”. The proposed new definition removes the ambiguity, but at a cost: it becomes difficult to justify treating amount of substance as having its own dimension, and hence its own unit, the mole. I argue that the difficulties with amount of substance result from its role as a mediator between macroscopic and microscopic scales. To understand why amount of substance might have its own dimension, we need to connect amount of substance to mass, contra current proposals to separate them.  相似文献   

20.
    
Summary Freshly dissolved heparin substance, in contrast to heparin which is commercially available, causes no decontraction of the isolated atropinized guinea-pig ileum contracted in response to histamine. Phenol and Cresol, in the amounts in which they are normally present in commercially available heparin preparations, have the same effect as commercial heparin.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号