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1.
The human trapezius muscle has an origin that is more extensive than that of any other body muscle; it has a complex macroscopic structure with fibers running in different directions. Histochemical analysis of multiple samples, obtained from different parts of the trapezius muscle from five males, showed marked differences in the distribution and the cross-sectional fiber area of the fiber types among different parts of the muscle as well as among individuals. As revealed by the mATPase activity, after different levels of alkaline and acidic preincubations, the lower third of the descending portion, the transverse, and the ascending portions of the muscle had a predominance of type I fibers (low mATPase activity at pH 9.4), whereas the most superior parts of pars descendens had a higher frequency of type II fibers (high mATPase activity at pH 9.4). The fibers of the most superior parts of the muscle were considerably smaller compared with those in all the other parts. In sections stained for NADH-TR, moth-eaten fibers were observed within parts of the descending portion. Their location and their larger fiber area, compared with that of ordinary type I fibers, may be related to frequent and/or continuous use of these fibers. In conclusion, the differences in fiber type composition between the different parts of the muscle probably reflect different functional demands on the trapezius muscle in various head, neck, and shoulder movements. We suggest that the interindividual differences in muscle fiber composition are due, at least in part, to genetic factors.  相似文献   

2.
The character of evoked potentials (EPs) dynamics to signal light stimulus during elaboration of avoidance reaction, allows to assert that during formation of adaptive activity functional balance is established of sensory and integrative-triggering brain parts or functional balance of "motor" and "sensory" integration regimes. Each of the studied subcortical structures is characterized by simultaneous but specific functioning both in the motor and sensory regimes; such conclusion is based on different dynamics of their EPs parameters: the changes of ones correspond to EPs dynamics in the visual cortical area, of the others--in the motor area. During chronic haloperidol administration, the reorganizations of intercentral relations are observed in 10--12 days after the beginning of drug administration. They may be considered as a succession of disturbances of functional balance between "sensory" and "motor" integration regimes: at first the sensory regime domination appears in which subcortical structures are chiefly and uniformly involved (ncd, pall and n. acc.); "motor" regime is weakened; then, as a result, a distortion of the "motor" regime of integration takes place. In this case a bradykinesia is developed.  相似文献   

3.
A study was carried out on 8 adult cats of functional role of the frontal, parietal and occipital parts of the neocortex, and also of the dorsal hippocampus, mediodorsal thalamic nucleus and caudate nucleus head, in realization of a delayed spatial choice (DSCh) before and after compensatory reorganizations of the brain activity caused by multiple electrical stimulation of the frontal part of the cerebral cortex. Compensatory reorganization led to a change of functional significance of these structures. While before this change the frontal cortex, hippocampus and mediodorsal thalamic nucleus were critically necessary brain areas for the realization of the DSCh, after it parietal and occipital cortical areas acquired such significance. The obtained data are discussed proceeding from the principle of the integrity in the brain activity.  相似文献   

4.
Agglutinin from Pemtigera aphthosa (L.) Willd. was isolated and its characteristics were obtained. It is a glycoprotein lectin with D-galactose specificity. Lectin concentration decreases from the apical parts of the thallus to its basal region. Finer differences in the agglutinating activity of different parts of the thallus reflect physiological differences in certain areas and their role in the functioning of lichen symbiosis.  相似文献   

5.
The generation of somites, and the subsequent formation of their major derivatives, muscle-, cartilage-, dermis- and tendon-cell lineages, is tightly orchestrated and, to different extents, these are also mutually supporting processes. They involve complex and timely reorganizations of the paraxial mesoderm, such as multiple phases of epithelial-mesenchymal rearrangements and vice-versa, cellular movements and migrations, and modifications of both cell shape and cell cycle properties. These morphogenetic changes are triggered by local environmental signals and are tightly associated to a genetic program imparting cell-specific fates. Elucidating these signals and their downstream effectors, in addition to determining the state of specification of responsive cell subsets and that of single progenitors in the various domains, is only beginning.  相似文献   

6.
In 13 healthy subjects dynamic characteristics of potentials spatial-temporal organization (PSTO) in the cortical left and right hemispheres at presentation of emotionally coloured and indifferent graphic images were studied by the method of quantitative evaluation of subsequent electroencephalotopograms. It is shown that, in contrast to the state of calm alertness, presentation of emotional and indifferent images leads to a decrease of the time of discordance in the hemispheres activity i.e. to synchronization increase. At the action of emotionally coloured images differences were found between the reorganizations of the left and right hemispheres, while there were no such differences at the presentation of indifferent images.  相似文献   

7.
8.
The expression of genomic instability was studied at the phenotypical (morphological characters, electrophoretic spectra of seed storage proteins) and molecular (DNA amplification products) levels in interspecific hybrids (ISHs) from crosses of inbred lines of cultivated sunflower Helianthus annuus with perennial species of the genus Helianthus and in introgressive lines (ILs) produced on their basis. Unstable state of the locus determining the trait of lower branching was proved by the method of hybridological analysis. It was shown with the use of RAPD markers that the IL genome is characterized by instability even after long-term inbreeding (in generations F8-F12). In progenies of different combinations of interspecific crosses, identical polymorphic variants were revealed for a seed storage protein, helianthinin, and for DNA fragments homologous to structural genes of functionally important proteins, suggesting the nonrandom character of ISH genome variation. This variation may be determined by genome reorganizations under the action of a genome shock induced by interspecific hybridization. The factors inducing reorganizations in the genome include the activity of mobile genetic elements (MGEs). Using primers specific to different MGE families, nucleotide sequences with a high level of homology to the sequences of fragments of the mobile elements MuDR, Far1, CACTA, Stowaway, and Tourist were identified in the sunflower genome. The possibility of using MGE fragments for sunflower genotyping was demonstrated.  相似文献   

9.
It was shown that the activity of alpha-amylase in the pancreas tissue, intestine content and blood, as well as kinetic characteristics in different substratum concentration changed in males and females after unitary oral administration of chloride cadmium in the dose 5 mg/kg. It was revealed that, after a single administration of chloride cadmium, growth of the pancreas weight, contents of protein and activity of alpha-amylase in the pancreatic tissue increased with parallel reduction of activity of enzyme in the small intestine. In acute cadmium intoxication, functional reorganizations in the pancreas are identical to initial stages of carcinogenic shifts. Such shifts are more expressed in females in comparison with males, especially after the cadmium intoxication.  相似文献   

10.
A tumor promoter phorbol 12-myristate 13-acetate (PMA) induces characteristic reversible changes in the cell shape in certain fibroblastic lines. This reaction to PMA may be regarded as a prototype of reorganizations involving formation of stable cytoplasmic processes. Two specific drugs, Taxol and Colcemid, were used to study the role of microtubules and vimentin-containing intermediate filaments (IF) in the development of PMA-induced reorganizations. A short (I h) exposure to PMA induced formation of processes in the control cells rather than in the Colcemid treated cells having depolymerized microtubules and the IF that collapsed around the nucleus. A longer (3-4 h) exposure to PMA of the colcemid-treated cells induced a partial reversal of the IF collapse; those parts of peripheral lamellae that contained IF were transformed into narrow noncontractile processes. It is suggested that the local interaction of the IF with the actin system is an essential step in the formation of processes from lamellae.  相似文献   

11.
Hypokinesia lasting 40 and 90 days causes a number of ultramicroscopic reorganizations in neurons, synapses and glial elements of the singular cortex and the central amygdaloid nucleus. The longer the time of hypokinesia, the more numerous and variable the reorganizations become. For the amygdaloid body presence of neurons with various degree of chromatolysis, reactive and destructive changes of organells, agglutination and reduction in number of the synaptic vesicles, increasing number of synapses, possessing certain features of low functional activity are most specific. For the singular cortes are peculiar convolution of nuclear and cellular membranes, synaptic contact, increasing intercellular spaces, as well as changes in the structure of some axo-spine synapses, the spine apparatus including.  相似文献   

12.
Diatoms possess effective photoprotection mechanisms, which may involve reorganizations in the photosynthetic machinery. We have shown earlier, by using circular dichroism (CD) spectroscopy, that in Phaeodactylum tricornutum the pigment-protein complexes are arranged into chiral macrodomains, which have been proposed to be associated with the multilamellar organization of the thylakoid membranes and shown to be capable of undergoing light-induced reversible reorganizations (Szabó et al. Photosynth Res 95:237, 2008). Recently, by using small-angle neutron scattering (SANS) on the same algal cells we have determined the repeat distances and revealed reversible light-induced reorganizations in the lamellar order of thylakoids (Nagy et al. Biochem J 436:225, 2011). In this study, we show that in moderately heat-treated samples, the weakening of the lamellar order is accompanied by the diminishment of the psi-type CD signal associated with the long-range chiral order of the chromophores (psi, polymer or salt-induced). Further, we show that the light-induced reversible increase in the psi-type CD is associated with swelling in the membrane system, with magnitudes larger in high light than in low light. In contrast, shrinkage of the membrane system, induced by sorbitol, brings about a decrease in the psi-type CD signal; this shrinkage also diminishes the non-photochemical quenching capability of the cells. These data shed light on the origin of the psi-type CD signal, and confirm that both CD spectroscopy and SANS provide valuable information on the macro-organization of the thylakoid membranes and their dynamic properties; these parameters are evidently of interest with regard to the photoprotection in whole algal cells.  相似文献   

13.
Plants of the genus Dieffenbachia, very popular as indoor ornamental plants, are known for their toxic as well as therapeutic properties. Their toxic manifestations have been partly attributed to their proteolytic activity. The work described in the present paper shows that stem leaves and petiole of Dieffenbachia maculata Schott, a commonly grown species, contain significant proteolytic activity, different parts showing different types of protease activities. Stem showed the highest enzyme activity and this protease was purified about 55 fold by solvent precipitation, gel filtration and ion exchange chromatography. The enzyme has a relative molecular mass of 61 kDa as determined by SDS-PAGE and has an optimum pH of 8.0 and optimum temperature of 50 degrees C. Effects of various substrates, inhibitors and activators indicate that the enzyme is a cysteine protease with leucylpeptidase activity.  相似文献   

14.
The mouse mandible consists of several morphogenetic units that are usually grouped into two main modules: the alveolar region and the ascending ramus. The genetic/ontogenetic modularity of the two regions implies that they might evolve independently to some extent. In particular, evolutionary modularity in quantitative traits could arise during chromosomal speciation due to lower gene flow in rearranged chromosomes. With the aim of uncovering the autonomous evolution of the mandible modules, the form variation of each of them was assessed in the house mouse Robertsonian system from Barcelona, in which chromosomal variation and geographical distance may act as isolation factors. The association between these factors and morphological changes was analysed to determine their contribution to the differentiation of each module. Although size changes in the two modules were highly correlated, shape changes were not, and their association with karyotype differences, but not geographical distance, was dependent on the module. The results support the existence of two evolutionary modules and highlight the importance of size in morphological integration of the mandible. They also suggest that geographical distance and chromosomal reorganizations reduce gene flow between karyotypically divergent populations, but although geographical distance represents a global barrier to gene flow, the isolation produced by a set of chromosomal reorganizations only affects particular modules, probably depending on the number and location of loci with effects on a particular morphological region.  相似文献   

15.
Food and medicinal plants have been used for centuries against human diseases. The methanolic and aqueous extracts of different parts of Ocimum bacillicum Lam. (Niazboo or Sweet basil) of family Lamiaceae were investigated in vitro for their antibacterial properties against waterborne pathogens. The antibacterial properties of different parts of Ocimum bacillicum samples were assessed against Gram positive and Gram negative bacteria, which were isolated from water samples and identified by the API 20E method. The extracts from leaves and seeds of Ocimum bacillicum showed more antibacterial activities against Staphylococcus aureus, Pseudomonas aeruginosa, and E. coli at 37°C than those obtained from shoots, roots, and buds. The lowest minimum inhibitory concentrations and minimum bactericidal concentrations were observed for leaves and seeds as compared to other parts of the plant. No activity of alum was observed against the tested bacterial strains. The seeds of Ocimum bacillicum were associated with higher coagulation activity in comparison to other parts of the plant and were comparable with alum. These results suggest that parts of a plant offer a potential for antimicrobial treatment of drinking water, but needs further exploration.  相似文献   

16.
Cepaea nemoralis L., C. hortensis Mull, and Arianta arbustorum L. show differences in survival, rate of water-loss and behaviour under conditions of low humidity in laboratory studies. C. nemoralis survives better, ceases activity more rapidly, and loses proportionally less weight in low humidity than C. hortensis , which in turn shows the same properties with respect to A. arbustorum . The differences between these three species are reflected in differences in distribution in parts of Britain.  相似文献   

17.
The material properties of bone can vary considerably among skeletal elements from different parts of the body that serve different functions. However, functional demands placed on a specific type of skeletal element also can vary at a variety of scales, such as between different parts of the element, among individuals of a species, and across species. Variation in bone material properties might be correlated with differing functional demands at any of these scales. In this study we performed three-point bending tests on bone specimens extracted from antlers of moose (Alces alces) to test for three types of variation in bone material stiffness (Young's modulus): within the antler structure, between populations of moose, and between moose and other deer species. Because superficial portions of the antler are exposed to greater bending stress and strain than deeper portions, and because the antler beam (the basal shaft that attaches to the skull) is subjected to greater bending moments than more distal parts of the antler, we predicted that superficial bone and bone from the beam would be stiffer than bone from other parts of the antler. Instead, we identified no significant differences in these comparisons. There were also no significant differences in antler stiffness between moose from Michigan and the Yukon, even though the rapid growth required of antlers from northern latitudes like the Yukon has the potential to compromise bone material properties. However, moose have significantly stiffer antlers (11.6 +/- 0.45 GPa, mean +/- SE) than any other deer in the odocoileine lineage. Moreover, phylogenetic reconstructions of the evolution of antler stiffness in deer indicate a strong potential that high antler stiffness is a derived feature of moose. The unusual palmate shape of moose antlers likely subjects their antler beams to higher bending moments than found in other odocoileines, a factor that may have contributed to the evolutionary divergence of moose antler stiffness from that of other members of this clade. Although similarities in the mineral composition of bone across species likely limit the overall range of phylogenetic variation in bone material properties, our results demonstrate that evolutionary diversity in bone material properties can show correspondence with phylogenetic differences in mechanical or ecological demands on skeletal elements.  相似文献   

18.
Summary This paper is based on the results of Primate chromosome studies obtained using high resolution techniques in our and other laboratories. We discuss the origin and the evolution of the chromosomes in the human karyotype and the time in evolution of the Simiiformes when they acquired their present morphology. Our results indicate that the chromosomes that underwent a higher number of reorganizations during the evolution of the Simiiformes coincide with the chromosomes most often implicated in human chromosome pathology. We describe the main reorganizations that took place during Primate evolution. Centromere activation and inactivation and heterochromatin changes are discussed as mechanisms of chromosome evolution.  相似文献   

19.
Plant development results from controlled cell divisions, structural modifications, and reorganizations of the cell wall. Thereby, regulation of cell wall behaviour takes place at multiple length scales involving compositional and architectural aspects in addition to various developmental and/or environmental factors. The physical properties of the primary wall are largely determined by the nature of the complex polymer network, which exhibits time-dependent behaviour representative of viscoelastic materials. Here, a dynamic nanoindentation technique is used to measure the time-dependent response and the viscoelastic behaviour of the cell wall in single living cells at a micron or sub-micron scale. With this approach, significant changes in storage (stiffness) and loss (loss of energy) moduli are captured among the tested cells. The results reveal hitherto unknown differences in the viscoelastic parameters of the walls of same-age similarly positioned cells of the Arabidopsis ecotypes (Col 0 and Ws 2). The technique is also shown to be sensitive enough to detect changes in cell wall properties in cells deficient in the activity of the chromatin modifier ATX1. Extensive computational modelling of the experimental measurements (i.e. modelling the cell as a viscoelastic pressure vessel) is used to analyse the influence of the wall thickness, as well as the turgor pressure, at the positions of our measurements. By combining the nanoDMA technique with finite element simulations quantifiable measurements of the viscoelastic properties of plant cell walls are achieved. Such techniques are expected to find broader applications in quantifying the influence of genetic, biological, and environmental factors on the nanoscale mechanical properties of the cell wall.  相似文献   

20.
The contents of some elements in green and whitish yellow parts of the leaves of Hedera helix and Acer negundo were examined. The contents of N, P and K were considerably higher in whitish yellow parts of the leaves compared with the green ones, and contrary to Ca in both plant species. Mg behaved like N, P and K in Hedera but like Ca in Acer. The same results were obtained in the leaves which were completely green or whitish yellow. The metabolic activities in different parts of the leaves were evaluated on the basis of the content of the individual elements. Differently coloured parts of the leaves of variegata type show differences not only in morphology and structure but also in their metabolic activity.  相似文献   

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