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1.
After chronic administration of propranolol (1 and 5 mg/kg, 14 days) to rats time-course of forced swimming changed with the decrease of rhythmical index of depression. The drug attenuated depressogenic properties of reserpine and clonidine. Propranolol antidepressive activity is attributed to blockade cerebral adrenoreceptors.  相似文献   

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Y. enterocolitica and Y. pseudotuberculosis have been experimentally found to penetrate into plants (cabbage, salad, pea, oat) from infected soil and water and to remain in different plant organs (roots, seeds, leaves) up to 30 days (the term of observation). The processes of S-R dissociation in Yersinia cultures isolated from plants, as well as changes in some enzymatic properties, have been established. In the test on Infusoria the cytotoxic action of strains isolated from plants has been noted. The possible role of plants in carrying pathogenic bacteria from the soil to the surface ecological systems and the subsequent infection of animals and humans is discussed.  相似文献   

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Certain problems in the dynamics of the human body are characterized by large displacements of the parts of the body compared to the deformations of the tissues themselves. In such problems, it is convenient to think of the human body as a chain of rigid links, representing the anatomical segments, with joints between the rigid links representing the articulations of the human body.

Skeletal muscles are capable of creating torques at the joints of the body. The joint torques of the rigid link model should portray the static strength of skeletal muscle, the degradation of muscle strength with rate of shortening, the feedback control of the stretch reflex, and the viscoelastic properties of the muscles, tendons, and joint capsules.

In this study a sinusoidal test is performed upon the knee joints of nine subjects. The increment of knee moment required to flex and extend the knee slightly for various conditions of knee angle, knee angular velocity, and steady knee moment is measured. The hip angle is maintained constant. After the effects of leg inertia are removed, the resulting data are shown to obey a Maxwell fluid model in which the model coefficients depend upon the absolute value of the knee moment.  相似文献   


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In experiments in white mice and rats the antidepressants pyrazidol (pirlindole), moclobemide and especially tetrindole possess anticalcium activity in tests of calcium chloride-induced lethality in mice and arrhythmia in rats. Tetrindole is as active as verapamil. Imipramine, azaphen and incazane were not active in these experiments. In vitro on isolated intestinal segments of guinea-pigs tetrindole exerts anticalcium action, but in less degree than verapamil. In all probability the anticalcium activity of tetrindole may play some role in the mechanism of action of this compound on the central nervous system.  相似文献   

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袁淑德  宋可钦 《生理学报》1991,43(5):512-517
The effect of fluorosis on lactation, lactotroph function and ultrastructure were studied in lactating rats. The results were as follows: 1) Inhibition of lactation in lactating rats with chronic fluorosis was assessed by stunting growth of pups and decrease in the amount of milk suckled by pups in 30 min. Metoclopramide, a blocker of dopamine receptor, could improve lactation in these rats. 2) During chronic fluorosis serum PRL level was decreased, however, PRL content in pituitary was increased. Electronmicroscopic examination showed accumulation of large mature secretory granules and appearance of extremely large abnormal secretory granules in lactotroph cytoplasma. These findings indicate that hormone release of pituitary lactotrophs is obstructed in lactating rats with fluorosis, and the toxic effect of fluoride is mediated by an enhanced function of dopaminergic system in hypothalamus.  相似文献   

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After REM sleep deprivation antidepressant shifts in forced swimming with increase of time of immobility and decrease of rhythmical index of depression were observed. Pinealectomy did not remove, but attenuated these behavioural changes.  相似文献   

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In experiments with mice a study was made of the radiosensitizing efficacy of 10 aromatic carbonic acid amides, benzene, naphthalene, pyridine and quinoline derivatives. It has been found, for this group of substances, that there is a direct correlation between the ability of the substance to reduce the splenic endocolonies production and the inhibitory activity with regard to poly(ADP-ribose) polymerase of thymocyte nuclei. Within the group of substances under study, new agents are found and described and new relationships are revealed between their chemical structure and biological activity.  相似文献   

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The decrease of learning ability by 50% as assessed by passive avoidance test and the increase 28% of microviscosity of synaptosomal membranes from brain cortex were observed in rats in a month after orchidectomy as compared with that of intact or sham--operated animals. The treatment of orchidectomized rats with piracetam either by single application or in the course of 10 days applications in the daily dose of 250 mg/kg intraperitoneally failed to improve learning ability of animals in passive avoidance test and to produce a normalizing effect on the structure of membrane lipid matrix. The testosterone content in blood of orchidectomized rats was 10 times lower as compared with control and was not affected by treatment with piracetam.  相似文献   

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A preclinical study of seven batches of lactoglobulin, a new biological preparation against opportunistic bacteria and salmonellae, has been carried out. High antibacterial activity of the preparation with respect to the virulent forms of Salmonella typhimurium, Salmonella enteritidis, Pseudomonas aeruginosa, Klebsiella pneumoniae, Proteus vulgaris, Proteus mirabilis has been established. The preparation has been shown to be safe and nontoxic. The 4-year term of its storage at a temperature of 6 degrees +/- 4 degrees C has been substantiated.  相似文献   

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A comparison of colchicine-treated and normal root tips of onion provides information on the role of the spindle in mitosis, and clearly indicates the value of colchicine in the analysis of karyotypes. An improved Feulgen-squash technique is recommended, with which high quality preparations of chromosomes can be obtained as a matter of routine. This cytological exercise requires little equipment and is suitable for undergraduate courses and advanced classes in schools.  相似文献   

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An experimental study on the self-reference effect   总被引:10,自引:0,他引:10  
Self-reference at encoding increases the probability of recollective experience in recognition memory. Self-reference effect (SRE) in memory is observed when the degree of self-reference of to-be-remembered materials is varied. Usually items encoded in terms of self-reference are associated with significantly higher recall performance relative to items encoded in other ways, including semantic encoding. In our three experiments, four orientating tasks formed four levels in a between-subjects design. The conditions were rating personality traits with reference to self, mother, Lu Xun (a famous Chinese writer) or rating the traits on a negative-positive dimension. In a recognition test, subjects first identified old items and then indicated which of these were accompanied by recollective experience ('remember' responses) and which were recognized on some other basis ('know' responses). Our results showed that both the self-reference condition and mother condition were associated with the same highest propo  相似文献   

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Self-reference at encoding increases the probability of recollective experience in recognition memory. Self-reference effect (SRE) in memory is observed when the degree of self-reference of to-be-remembered materials is varied. Usually items encoded in terms of self-reference are associated with significantly higher recall performance relative to items encoded in other ways, including semantic encoding. In our three experiments, four orientating tasks formed four levels in a between-subjects design. The conditions were rating personality traits with reference to self, mother, Lu Xun (a famous Chinese writer) or rating the traits on a negative-positive dimension. In a recognition test, subjects first identified old items and then indicated which of these were accompanied by recollective experience (‘remember’ responses) and which were recognized on some other basis (‘know’ responses). Our results showed that both the self-reference condition and mother condition were associated with the same highest proportion of correct remember responses and the same lowest proportion of correct know responses. In contrast, for Western subjects, the self-reference condition, relative to the mother condition, was associated with a higher proportion of correct remember responses and a lower proportion of correct know responses. We discussed the results with reference to the HERA model (hemispheric encoding/retrieval asymmetry).  相似文献   

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CD spectra have been measured in the vacuum-uv region to about 135 nm for cyclo(L alanyl-glycine), cyclo(L alanyl-L -alanine), and cyclo(L -prolyl-L -proline). In addition to the amide CD bands usually observed at wavelengths longer than 180 nm, a Independent systems calculations show that these intense short-wavelenght bands can be attributed to σσ* transitions of the backbone. Transitions of the amide chromophore expected at wavelenghts shorter than 180 nm cannot account for the observed CD.  相似文献   

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Musk-rats were infected simultaneously and at three-day interval with tularemia and Omsk hemorrhagic fever (OHF); the course of this mixed infection under the mentioned conditions were studied. Virological, microbiological and morphological data indicated that infection of musk-rats with OHF and tularemia caused development of mixed infection in them. A more severe course of mixed infection was associated with enhanced vascular affections caused by the action of the OHF virus. An inhibition of tularemia caused by the OHF development was noted in the course of mixed infection.  相似文献   

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