共查询到20条相似文献,搜索用时 31 毫秒
1.
The duration of the cellular cycle and the diurnal rhythm of the amount of mitosis were studied in young rats in normality and under the influence of thyroxin. The parenchymal and connective-tissue cells of the liver and cells of the liver and the cells of the oesophagus epithelium basal layer were studied. It was found that under the influence of thyroxin there occured a shortening of the periods of the cellular cycle and a 3--6 h shift to the left of the diurnal rhythm curve of the amount of mitoses. In thyroxinized animals the 21--95% increase of the amount of mitoses in the period of maximum values of the mitotic index during a day was observed as compared with control animals. A conclusion is made about the diurnal rhythm of sensitivity of G0-phase cells to the synchronizing factor, suggesting the decisive significance of the state of the cell population in the interaction of the tissue and hormone cells. The data obatained in the work show that the thyroid hormones regulate the cellular reproduction in the organism by stimulating the cells in the division cycle, synchronization of greater amount of cells by the moment of beginning of the mitotic cycle at a definite time of day and by shortening the period of the cell mitotic cycle. 相似文献
2.
N K Nagradova 《Biokhimii?a (Moscow, Russia)》1977,42(3):379-395
The structure of the active center of glyceraldehyde-3-phosphate dehydrogenase and the arrangement of subunits in the tetrameric molecule is delineated. The mechanism of cooperative effects in the oligomer is considered, and the involvement of various regions of the active center and of different-subunit contact area in the realization of the cooperative phenomena is discussed. A special attention is paid to the effect of NAD+ bound to one of the subunits of the tetramer on the structure of an adjacent subunit and to the problem of the participation of the coenzyme in the creation of anion-binding sites of the enzyme. The conditions of reversible dissociation of the tetrameric apoenzyme molecule into dimers are depicted, and the role of NAD+ in the organization of the quaternary structure of the dehydrogenase is discussed. The problem of catalytic activity of the dimeric form of the enzyme is argued. 相似文献
3.
Kalamkarov GR Ostrovskiĭ MA 《Rossi?skii fiziologicheski? zhurnal imeni I.M. Sechenova / Rossi?skaia akademiia nauk》2004,90(5):658-675
In the first part of the paper, the results of the investigation of the rhodopsin arrestin interaction are presented. The results were mainly obtained with the technique of the selective labelling of the rhodopsin and arrestin SH-groups and the rhodopsin limited proteolysis. These results are discussed in the frame of the latest data on the three-dimensional structure of arrestin. In the second part of the paper, results of the antigenic properties of arrestin (S-antigen) and its role in the pathogenesis of the retina diseases are summarized. The data on the role of the autoimmune processes in the pathogenesis of diabetic retinopathy are presented. We have also described the results of the use of the elaborated technique of the immune diagnostics in the prognosis of the diabetic retinopathy and retinopathy of the premature babies. 相似文献
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The interferons (IFN's) are natural regulators of the immune response. This quality of IFN depends to a large extent on their capacity to change the expression of the antigens of the second (II) class of the Major Histocompatibility Complex. The most effective modulator of the expression of the antigens of the class II MHC is beta-IFN. The aim of this work is to explore with the aid of enzyme-linked immunosorbent assay (ELISA) peculiarities of an action of the preparations alpha- and beta-IFN's of a man on the expression of the antigens of the second class on macrophages of mice with using monoclonal antibodies to the products of subregions I-A and I-E MHC. As a result of exploration we have the following: both preparations IFN's (leukinterferon and beta-IFN) reinforce the expression of the antigens of the second class on the macrophages of mice spleens. With combined influence preparation alpha-IFN and beta-IFN show interweakened effect on the expression of the antigens of the class MHC. Exposed regularities of the expression have the same type for products of subregions I-A and I-E H-2 of mice complex. ELISA is the sensible method of determination of a level of the expression of the antigens of the class II MHC on the cell's populations. 相似文献
6.
N V Darinski? 《Biulleten' eksperimental'no? biologii i meditsiny》1975,80(7):9-11
Experiments were conducted on rats during the early postnatal period; a study was made of the membrane potential (MP) establishment of the fibers of the skeletal muscles of the neck, the anterior and the posterior limbs. At birth the most mature were the muscles of the neck, and the least -- the muscles of the posterior limb. Establishment of the stationary MP level in the muscles of the neck occurred during the first week after birth, in the muscles of the anterior limbs -- by the 10th-12th day, and of the posterior limbs -- by the 15th-20th day. The order of maturation of various groups of the skeletal muscles was associated with the peculiarities of the neuro-trophic influences at various age periods. Muscles of the neck were characterized at all the developmental stages by a rhythmic low-frequency electromyographic activity. In the muscles of the limbs the rhythmic electromyographic activity was transformed into the discharge high-frequency activity by the period of termination of increase of the MP of the muscles. 相似文献
7.
V P Praznikov 《Biulleten' eksperimental'no? biologii i meditsiny》1984,98(9):264-266
In 12-day-old rats, L-DOPA, a precursor of catecholamine synthesis, provokes an increase in the rate of the motor reactions (MR) of the shudder type. Reserpine which promotes catecholamine release from the tissues, leads to the diminution of the rate of the MR of the shudder type in rats of the same age. Aminazine, an alpha-adrenoblocker and antagonist of dopamine receptors, decreases the rate of the MR of the shudder type. Administration of aminazine in a dose of 10 mg/kg at different age periods produces inconclusive changes in the diminution of the rate of the MR of the shudder type. During sudden changes in the growth, the rate of the above-described modulations substantially decreases. The high rate of the MR of the shudder type seen in rats in the early postnatal period is a consequence of the marked activity of the catecholaminergic (dopaminergic) systems during that period. Reduction in the effect of the decreased MR rate produced by the same dose of aminazine during the critical periods of the growth also attests to the high activity of the catecholaminergic (dopaminergic) system in rats at that period. 相似文献
8.
C R Piffer 《Acta anatomica》1979,105(2):121-133
The author studied the structure of the tissue components of the tunicae of the terminal segment of the sigmoid sinus, particularly at the level of the transition between the sigmoid sinus, the superior bulb of the jugular vein and the first portion of the human internal jugular vein; it was established that the transition between the sigmoid sinus and the first portion of the internal jugular vein occupies the whole extension of the superior bulb of the jugular vein up to the inferior third of the first portion of this vessel. These vascular walls exhibit a structure similar to that of the dura, i.e. the tunica adventitia is formed by fascicles of collagenic fibers which describe discontinuous spirals, more open proximal to the beginning of the first portion of the internal jugular vein. Approximately in the inferior third of the first portion of the internal jugular vein, there appear fascicles of smooth muscle fibers which are arranged similarly to those of the venous walls. The tunica intima of these vascular segments exhibits an endothelium resting on a network of elastic fibers which may play the role of an internal elastic lamina. From the bony border of the jugular foramen there originates a connective system whose fascicles of collagenic and elastic fibers incorporate to the wall of the internal jugular vein after describing a stretch in spiral around the vascular lumen. 相似文献
9.
1. In each stage of the differentiation of the growing cones of these two varieties of wheat, their morphological characters are the same as of the general wheat, their fourth stage being the sign of the beginning of their reproductive structures. 2. The sequence of the differentiation in the development of spikelets is as follows: first the outer glume, then the inner glume, the lemma of the first flower, the primordium of the first flower, the lemma of the second flower and finally the primordium of second flower, etc.; while it is the palea, the stamens, the pistil and the lodicules for the flower part. 3. The differentiations of the primordiums of stamens and pistil start at the same time as the appearance of the awn. 4. It was found that in Kansu 96 the rate of the differentiation of the growing cones is more rapid, its volume bigger, the number of its spikelets and flowers, the chance of fruitification and its yield higher, than those of Yu-Chung-Hung, but the average individual weight of the grain is lower than that of the latter. 5. The rate of the differentiation of the growing cones will be slowed, and the numbers of spikelets, flowers and grains increased if a high moisture content of soil is present. The shape of the spike is grand and close under irrigation, but under drought it is slender and soft. Although the yield of Yu-Chung-Hung is lower than that of Kansu 96, but it appears to have a higher hydronasty than the latter. 6. It was shown in our investigation that the Kansu 96 appears to be of drought resistance. 7. Under normal conditions and in the same variety, the appearances of the leaf and the node of the stem, and the developmental phases of plants may be suggested as an indication of the differentiation of the growing cones. It is recommended that they can be used as a field crop. 相似文献
10.
T V Tiurina 《Arkhiv anatomii, gistologii i émbriologii》1985,89(11):75-81
By birth in the acromioclavicular joint the acromial end of the clavicle is osseous, and the acromion of the scapula is cartilaginous. The most intensive formation of the relief and configuration of the articular surfaces of the joint occurs from 1 to 3 years of age. In mature persons the form of the articular surface of the acromial end of the clavicle is often oval and that of the acromion of the scapula--ellipsoid. In newborns the areas of the articular surfaces are nearly equal. The area of the articular surface of the acromial end of the clavicle is significantly more than that of the acromion of the scapula during the periods from 1 to 3, from 13 to 17 and from 21 to 30 years of age. The articular cleft is revealed in the roentgenograms by 17 years of age, when synostosis process of the acromion of the scapula is completed. The thickness of the articular cartilage at different poles of the articular surfaces from birth up to 70 years of age is not equal and therefore it is possible to judge about nonequivalent functional loading on different areas of the articular cartilage. The articular cartilage of the acromial end of the clavicle from birth to 16 years of age is hyaline, after 17 years of age, they acquire the structure of the fibrous cartilage. In the articular cartilage of the acromion of the scapula, this rearrangement is realized more slowly: its fibrous structure is revealed after 23-24 years of age. Involutional changes in the joint are revealed during the fourth decade.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
11.
The characteristics of the bioelectrical reactions of structures of the medulla oblongata connected with lateral line electro- and mechanoreceptor were investigated in acute experiments on skates under urethane anesthesia. The parameters of the evoked potentials (EP) are characteristic of each of the lateral line nerves studied. A comparison of the characteristics of the fast and slow components of the EP obtained by stimulation of nerves of the medulla oblongata makes it possible to state a hypothesis concerning the presynaptic origin of the fast and the postsynaptic origin of the slow components of the EP. A dependence of the magnitude of the EP on the amplitude of the stimulus and on the location of the active electrode was found. The location of the focus of maximum activity was determined for each of the nerves investigated. A correlation was established between some parameters of the bioelectrical reactions of the medulla oblongata and the morphophysiological properties of the fibers which make up the nerves studied. The results obtained make it possible to assume the presence in the medulla oblongata of spatially arranged structures responsible for the development of the bioelectrical effects in response to stimulation of the lateral line nerves of fish.I. P. Pavlov Institute of Physiology, Academy of Sciences of the USSR, Leningrad. Translated from Neirofiziologiya, Vol. 3, No. 3, pp. 284–292, May–June, 1971. 相似文献
12.
随着我国医疗体制的改革,医院也面临着新形势下自身管理体系和管理方式的改革和创新。现代医院的管理模式也发生很大变化,从传统经验管理型逐步转变为现代管理型。现代医院管理采用科学的管理方法和管理技术,广泛地运用现代自然科学和社会科学的研究成果使管理手段现代化、科学化。现代医院药剂管理是医院管理工作的重要组成部分,对医疗质量及用药安全起着重要的作用。医院药剂管理的现代化可以保证用药的安全性,提高医疗质量,提高医院的核心竞争力,促进现代市场经济体制下医疗水平的提升和医院的发展。现代医院药剂管理的关键在于如何实现新模式下的管理目标及如何提高新模式下的药剂管理水平。本文结合我院在医疗改革背景下逐渐创新各个环节的管理模式,完善管理体系,突破管理瓶颈而获得的实践体会,进一步探讨现代医院药剂管理的方法及意义,为医院药剂管理工作提供理论指导。 相似文献
13.
I N Knipst 《Zhurnal vysshe? nervno? deiatelnosti imeni I P Pavlova》1991,41(6):1204-1214
Interhemispheric asymmetry was studied of spatial-temporal potentials organization (STPO) of the cortex in non-fixated animals in the states of deep rest, behavioural activity and in the transition period between them. Despite the intrahemispheric differences of the STPO in each of these states, interhemispheric divergences in the character of reconstructions of momentary topograms of the cortical potentials, recorded at 24-channels leading, are limited by 35% of the epoch analysis time. Comparison of the dynamics of intrahemispheric changes of topograms of cortical potentials in the left and right hemispheres in the states of rest and activity revealed a narrowing of temporal period of the absence of resemblance in reconstructions of successive topograms of the left and right hemispheres in comparison with transition processes. In the phase of rest the interhemispheric conjugation of spatial reconstructions in topograms became lowered mainly because of the disturbances of monotony of changes of their reliefs in one of the hemispheres in turn. In the active phase, deviations from STPO of the cortex, characteristic of the state of rest, were met more frequently in the right hemisphere; in that case oscillations of the topograms general mean level connected with the activity of non-specific activating subcortical brain system acquired a significant role in regulation of interhemispheric relations. Presence of interhemispheric resemblance of reconstructions of topograms reliefs in the active phase, despite the tendency to its lowering in comparison with the rest, testifies to the contribution also of the intracortical processes to the interhemispheric spatial synchronization of the cortical potentials in this state. 相似文献
14.
Moroz BB Deshevoĭ IuB Lyrshchikova AV Lebedev VG 《Radiatsionnaia biologiia, radioecologiia / Rossi?skaia akademiia nauk》2005,45(6):709-714
On lines of the mice genetically differing on the sensitivity on emotional stress (steady--of the mouse of the line C57BL/6 or sensitive--of the mouse of the line BALB/c), the research of the development of the adaptive reactions in the system of the blood on the emotional stress influencing animals on the background of the preliminary irradiation in a low dose (0.9 Gy) is carried out. The unirradiated mice of the line C57BL/6 adequately reacted on the stress, that was shown in a moderate behavioural reaction during the period of stress, and the development of high-grade adaptive reactions in the hemopoietic system. Among the mice of the line C57BL/6 in conditions of the combined influence of ionizing radiation and of the emotional stress was not revealed of the infringements of the adaptive reactions of the hemogenesis. As opposed to these data, among unirradiated mice of the line BALB/c the sharply expressed behavioural reactions during the stress were marked, that was accompanied by incomplete development of the adaptive reactions in the system of a blood on the stress. Under the influence of stress on the previously irradiated animal line BALB/c was observed the inhibition of the medullar hemopoiesis. 相似文献
15.
目的:对枕骨斜坡骨性结构及周围毗邻关系的解剖学测量,为经口咽入路行枕骨大孔扩大术提供详尽的解剖学数据及理论依据。方法:①选取成人干燥颅骨标本40例,分别测量斜坡颅底内面、颅底外面的长度;斜坡咽结节处宽度、斜坡最小厚度、中部厚度和最大厚度;斜坡与水平面的夹角;颈动脉管外口内缘、颈静脉孔内外口内缘、破裂孔内外口内缘、舌下神经内外口内缘、寰枕关节内缘与斜坡中线的距离。②选取完整头颈部标本20例,观察斜坡与周围血管神经的毗邻关系。结果:①斜坡颅底内面长(40.1±2.5)mm,外面长(28.2±3.1)mm;斜坡中部宽度(18.8±2.5)mm,;最小厚度(6.8±2.3)mm,;中部厚度(9.8±2.2)mm,最大厚度(11.5±1.7)mm;咽结节至枕骨大孔前缘距离(12.8±1.5)mm。②斜坡与水平面的夹角(46.8±4.5)°。③颈动脉管外口内缘距离斜坡中线(26.1±3.1)mm,颈静脉孔内口内缘距离斜坡中线(21.8±2.5)mm,颈静脉孔外口内缘距离斜坡中线(25.1±2.7)mm,破裂孔内口内缘距离斜坡中线(10.5±2.9)mm,破裂孔外口内缘距离斜坡中线(11.8±2.5)mm,舌下神经管内口内缘距离斜坡中线(13.8±2.3)mm,舌下神经管外口内缘距离斜坡中线(21.1±2.3)mm,寰枕关节内缘距离斜坡中线(10.5±2.3)mm。④斜坡上部距离后方基底动脉(7.6±1.0)mm,距离后方脑桥(8.3±1.2)mm,斜坡中部距离后方延髓脑桥沟(13.5±1.7)mm,斜坡下部距离后方延髓(6.5±0.8)mm。⑤斜坡上部与后方硬脑膜之间间隙为(1.8±0.2)mm,斜坡中部与后方硬脑膜之间间隙为(1.3±0.1)mm,斜坡下部与后方硬脑、脊膜之间间隙为(1.3±0.1)mm。⑥在斜坡开骨窗的宽度为20mm,高度为15mm,深度为6mm,可以满足经口咽入路枕骨大孔扩大术的要求,并有可靠的安全性。结论:本研究通过对斜坡骨性结构及周围毗邻关系的测量与观察,为临床斜坡区手术提供解剖学数据。 相似文献
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The ultrastructural study of chromatin condensation simultaneously with the evolution of the perinuclear organelles was conducted in the spermatids and epididymal and ejaculated spermatozoa of man with the aid of the “en bloc” alcoholic PTA staining and the EDTA regressive method. The round nuclei of young spermatids (steps 1, 2) were characterized by the persistence of nucleoli that were PTA positive, and the presence of a subacrosomal layer of well-stained peripheral chromatin. In the beginning of the phase of nuclear elongation (step 3), the central chromatin also became dense, like the peripheral chromatin, while the nuclear ring and the associated manchette and the two anlages of the postacrosomal dense lamina and the posterior ring appeared. During steps 4 and 5, the sliding of the nuclear ring and the manchette, the growth of the postacrosomal dense lamina, and the progression of the posterior ring towards the base of the nucleus were seen along with structural and cytochemical modifications of the chromatin. In the flattened nuclei of step 4 spermatids, coinciding with the loss of the nucleolar components, the chromatin achieved maximum compactness in the entire nucleus and was PTA positive. In the spermatids of step 5, the disappearance of peripheral dense chromatin and the specific staining of the chromatin granules marked the beginning of the second stage of transformation of the basic nucleo-proteins. The condensed nuclei of the mature spermatids were partially stained by PTA in step 6 and totally unstained in step 7. The PTA staining revealed the persistence of PTA-positive chromatin areas in the nuclei of certain spermatids otherwise mature. The morphological aspect of the chromatin then remained the same in the nuclei of epididymal and ejaculated spermatozoa. These observations suggest that in man, as in other mammals studied, new proteins accumulate in the elongating nuclei of spermatids and are replaced at the phase of maturation by sperm-specific nucleoproteins. The defects in condensation of the chromatin that occur during spermiogenesis could be related to the modalities of accumulation of intermediate nucleoproteins. 相似文献
18.
Artiukhov VG Kalaev VN 《Radiatsionnaia biologiia, radioecologiia / Rossi?skaia akademiia nauk》2005,45(5):619-628
The examination of cytogenetic characteristics (the mitotic activity, the time of passing of the mitotic stages by cells, the level and the spectrum of mitosis disturbances, the nucleoli characteristics) of seed progeny of common oak trees, exposed to the radiation exposure after the accident at the Chernobyl Nuclear Power Station and growing at the territories with different levels of anthropogenic contamination was held. In spite of the normalization of the radioactive level at the examined territories the changes of the cytogenetic characteristics of common oak seed progeny in comparison with the control were noticed. Obtained results are explained from the position of the radiation induced genomic instable and of the wave kinetic of the mutation process. The questions of the advisability and of the validity of using of the seed progeny of the common oak trees, exposed to the radiation exposure, in forest restoration measures are discussed. 相似文献
19.
The photo-dependent absorption changes of cytochrome f in bean chloroplasts and native leaves treated with the polyene antibiotics surgumycin and filipin were studied. Upon incubation of the chloroplasts or leaves with the antibiotics the value of the photo-induced signal of cytochrome f decreased considerably; however, the kinetics of the cytochrome oxidation under the effect of the exciting light and dark reduction remained unchanged. An addition of plastocyanin to the suspension of the antibiotic-treated chloroplasts, which contained no artificial donors and acceptors, only slightly increased the absolute value of the photo-induced signal of cytochrome f. An addition of plastocyanin to the chloroplasts containing the dichlorophenolindophenol-ascorbate-methylviologen system, sharply changed the kinetics of the cytochrome f photoconversions. A simultaneous registration of the photo-induced signal of cytochrome f and the photochemical activity of photosystem I of the antibiotic-treated chloroplasts revealed differences in the degree of inhibition of the photosystem I activity and decrease of the absolute value of the cytochrome f signal. The data obtained are discussed in terms of possible alternative pathways of electron transfer in the part of the electron transporting chain under study. 相似文献
20.
A L Zashikhin 《Arkhiv anatomii, gistologii i émbriologii》1976,71(12):43-49
Histological, histochemical and neurochemical methods were used in order to study the features of the histogenesis of structures of the atrioventricular area of the conducting system of the heart and the formation of their cholinergic innervation in the postnatal period of the hog. Under study were 175 hearts of embryos of the hog at the age of 3, 4, 5, 6, 8, 10, 12, 14 and 15 weeks and 22 hearts of adult hogs. The formation of different areas of this system was shown to be asynchronous. The atrioventricular fascicle is formed during the 4th week, the atrioventricular node -- during the 6th week and the conducting muscle fibres--during the 8th week of embryogenesis. The fascicle and the node have a complicated structure and different cellular composition. In the process of prenatal ontogenesis the increased amount of glycogen and increased activity of phosphorylase were noted in the cytoplasm of myocytes of the atrioventricular area of the conducting system of the heart. The cholinergic nerve fibres grow up to the structures of the atrioventricular area of the conducting system of the heart during the 6th week of embryogenesis, and by the end of the prenatal development they form a thick network in all its structures. 相似文献