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1.
Using a mathematical methodology based upon the theory of pattern recognition, the adequacy of this methodology being confirmed by the corroborative results obtained with neuro-net non-parametric methods of analysis, it proved possible to discriminate reliably between generalized organism's statuses, as described with a big number of laboratory indices, of the inhabitants of different areas of a big industrial city which differ in levels of radioactive and non-radioactive environmental pollution.  相似文献   

2.
Brain-derived neurotrophic factor is selectively expressed at relatively high levels in the rat hippocampal formation (for review, see Ref. 12; see also Refs 8, 13, 19, 20, 27) where it is thought to be involved in mechanisms of neurodegeneration and/or neural protection related to the plasticity of hippocampal neurons. Functional responses to brain-derived neurotrophic factor appear to be mediated by a tyrosine receptor kinase B with the possible involvement of the p75 low-affinity nerve growth factor receptor protein. Among the many characteristics of Alzheimer's disease is an upregulation of immune mediators in and around senile plaques in Alzheimer's disease. Recently, interleukin-1 has been shown to be detrimental to the long-term survival of embryonic hippocampal neurons in culture. Thus, if the same occurs in vivo, it is possible that the accumulation of interleukin-1 in Alzheimer's disease hippocampus may be responsible for altered hippocampal neuron synaptic plasticity. This may occur either by a direct action of interleukin-1 on hippocampal neurons or possibly indirectly by stimulating beta-amyloid production. Other indirect mechanisms may involve growth or survival factors such as the neurotrophin brain-derived neurotrophic factor which is thought to play an important role in the plastic responses of hippocampal neurons. A recent study showed that brain-derived neurotrophic factor mRNA is selectively decreased in the dentate gyrus in Alzheimer's disease. The reason(s) for the decrease of brain-derived neurotrophic factor mRNA is not known, but one possibility may be associated with the enhanced expression of interleukin-1 in the hippocampus of Alzheimer's disease patients.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

3.
PURPOSE: To quantify S-antigen-specific (S-Ag) T cells in the retina after adoptive transfer, and to evaluate their role in the initiation and progress of destructive ocular inflammation in experimental autoimmune uveoretinitis (EAU). METHODS: Lewis rats were administered 10 x 10(6) S-Ag-specific T cells from the SP35 cell line or 10 x 10(6) concanavalin A-stimulated syngeneic spleen cell lymphoblasts labeled with lipophilic PKH26 fluorescent dye immediately before intravenous inoculation. Labeled cells in each retina were counted at various times from 4 to 120 hours after cell transfer by fluorescence microscopic analysis of each dissociated retina. Recipient eyes were examined within the same period by light and confocal microscope. RESULTS: SP35 T cells showed a biphasic distribution in the retina. The first peak of 160 cells/retina was noted at 24 hours. A steady decline of labeled cells at 48 and 72 hours was followed by a rapid increase at 96 and 120 hours. Concanavalin A-stimulated, control-labeled cell populations showed an identical peak at 24 hours but a persistent decline thereafter; only two or three T cells were present in each retina at 120 hours. Concurrent inoculation of SP35 cells and nonspecific T cell blasts did not produce more SP35 cells than control cells in the retina at any time. Microscopic analysis showed mononuclear cell infiltration of the iris, ciliary body, and aqueous humor at 48 hours, which intensified rapidly and persisted through 120 hours. Retinal inflammation did not begin until 80 hours. Mononuclear cell adherence to vascular endothelium and perivascular macrophage infiltration of the innermost layers progressed to edema, and profound destructive inflammation and loss of retinal stratification were observed at 120 hours. CONCLUSIONS: There is no evidence of a blood-ocular or blood-retinal barrier to activated T cell blasts. Autologous S-Ag does not provoke a more rapid entry of specific T cells at that site. The data confirm that anterior segment inflammation precedes retinal inflammation, even though S-Ag-specific T cells were present in the retina within a few hours after cell transfer. Because S-Ag is clearly present in the retina, delay in antigen presentation at that site may account for the temporal difference between retinal and anterior segment inflammation.  相似文献   

4.
Twenty-eight patients exposed to acute and chronic ionizing radiation were followed up. Radiation cataracts were diagnosed in 22 eyes. Localizations of changes in the lens after ionizing and solar radiation are similar. Opacities are localized under the posterior lenticular capsule, round the nucleus, and under the anterior capsule and do not depend on the type of radiation. Opacities caused by solar radiation are notably smaller and look as numerous small dots. Study of cataracts of different origin and assessment of the efficacies of different anticataract drugs were carried out for evaluating the progress of different types of cataracts (cellular, extracellular, and capsular forms).  相似文献   

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The comparative study of newly discovered pathogenic bacteria of the genus Francisella was carried out with the use of a complex of microbiological and serological methods. While having great similarity to the causative agent of tularemia, F. novicida, F. novicida-like bacteria and F. philomiragia had lesser growth requirements, some specific morphological and structural features, were capable of fermenting sucrose and exhibited low pathogenicity to experimental animals. The strains under study proved to be virulent with regard to golden hamsters, who were for this reason proposed as an adequate model for the isolation of these bacteria from environmental objects and pathological material obtained from patients. The use of immunoblotting made it possible to find out that all Francisella species had protein antigens, similar to their electrophoretic mobility and serological activity.  相似文献   

8.
Structurally related tetratricopeptide repeat motifs in steroid receptor-associated immunophilins and the STI1 homolog, Hop, mediate the interaction with a common cellular target, hsp90. We have identified the binding domain in hsp90 for cyclophilin 40 (CyP40) using a two-hybrid system screen of a mouse cDNA library. All isolated clones encoded the intact carboxyl terminus of hsp90 and overlapped with a common region corresponding to amino acids 558-724 of murine hsp84. The interaction was confirmed in vitro with bacterially expressed CyP40 and deletion mutants of hsp90beta and was delineated further to a 124-residue COOH-terminal segment of hsp90. Deletion of the conserved MEEVD sequence at the extreme carboxyl terminus of hsp90 precludes interaction with CyP40, signifying an important role for this motif in hsp90 function. We show that CyP40 and Hop display similar interaction profiles with hsp90 truncation mutants and present evidence for the direct competition of Hop and FK506-binding protein 52 with CyP40 for binding to the hsp90 COOH-terminal region. Our results are consistent with a common tetratricopeptide repeat interaction site for Hop and steroid receptor-associated immunophilins within a discrete COOH-terminal domain of hsp90. This region of hsp90 mediates ATP-independent chaperone activity, overlaps the hsp90 dimerization domain, and includes structural elements important for steroid receptor interaction.  相似文献   

9.
Investigated preferences among allocation procedures available for use by those distributing rewards for individual performance in a group effort. It was hypothesized that allocators would try to balance the payoff distribution in response to all available information about the individual members. A target person's level of contribution to the group effort and level of financial need were manipulated in questionnaires distributed to 304 undergraduates. Results show a main effect for both individual characteristics but no interaction between them, thereby supporting the hypothesis of independent additive effects. Whether group characteristics would serve only to modify the effects of the individual characteristics, was tested by manipulating 2 group characteristics: morale and task outcome. As predicted, no main effects for either group level variable emerged. Further, the effect of contribution was greater under failure than success and under low than high morale. The effect of need was greater under low morale but only for female allocators. (27 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

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Cytoarchitectonics of cerebral cortical fields 44 and 45 was studied in gifted people in comparison with the group of people without creative professional talents. Frontal paraffin sections 20 mkm thick were examined. Both histological and modern quantitative methods were used with the aid of "Videoplan" computer. Peculiarities in the cytoarchitectonics of cortical fields 44 and 45 and, in particular, in expression of the nerve cell horizontal and vertical orientation and in the characteristics of the certain cortical fields delimination were demonstrated. Increase of pyramidal neuron glial index and of peculiarities of neurons regrouping in cytoarchitectonic layers III and IV was noted.  相似文献   

12.
The study was conducted on 48 free-moving male rats to find out the role of the medial preoptic alpha2 receptors in the regulation of sleep and body temperature. Recording electrodes for assessment of sleep-wakefulness, and injector cannulae for injection of drugs in the medial preoptic area were chronically fixed on the skulls of the animals. The noradrenergic fibres projecting to the medial preoptic area were destroyed in 24 rats by administration of 6-hydroxydopamine at the ventral noradrenergic bundle. Though arousal was produced in normal rats by the injection of the alpha2 adrenergic agonist, clonidine, at the medial preoptic area, it induced sedation in rats with noradrenergic fibre lesion. Clonidine did not alter the rectal temperature in normal rats but it induced hypothermia in lesioned rats. Injection of alpha2 antagonist, yohimbine, at the medial preoptic area induced sleep in rats with intact noradrenergic fibres. However, the sleep inducing effect of this drug was very much attenuated in the lesioned animals. There was no significant change in body temperature, in both these groups of animals, after yohimbine administration. The study indicates the role of presynaptic alpha2 adrenergic receptors in arousal response and indirectly supports the contention that the alpha1 postsynaptic receptors at the medial preoptic area are involved in hypnogenesis. It also suggests that the thermal changes induced by adrenergic system are mediated through alpha1 postsynaptic receptors. But the thermal changes do not contribute towards the induced alterations in sleep-wakefulness. It is proposed that there should be separate sets of noradrenergic terminals for regulation of sleep and body temperature.  相似文献   

13.
Successful import of hundreds of nucleus-encoded proteins is essential for chloroplast biogenesis. The import of cytosolic precursor proteins relies on the Toc- (translocon at the outer chloroplast membrane) and Tic- (translocon at the inner chloroplast membrane) complexes. In Arabidopsis thaliana,precursor recognition is mainly mediated by outer membrane receptors belonging to two gene families: Toc34/33 and Toc159/132/120/90. The role in import and precursor selectivity of these receptors has been intensively studied,but the function of Toc90 still remains unclear. Here,we report the ability of Toc90 to support the import of Toc159 client proteins. We show that the overexpression of Toc90 partially complements the albino knockout of Toc159 and restores photoautotrophic growth. Several lines of evidence including proteome profiling demonstrate the import and accumulation of proteins essential for chloroplast biogenesis and functionality.  相似文献   

14.
A study has been made, using the transpiration technique, of the volatility of chromic oxide in oxygen-chlorine-argon mixtures in the temperature range 627 to 977°C. Under the conditions of the experiments, the volatilization is shown to occur by the reaction Cr2O3(s) + 2Cl2(g) + 1/2O2(g) = 2CrO2Cl2(g). The standard Gibbs free energy change is given by AG° = 90,900(±1200) + 16.46(±1.2)TJ, where the reference state for the gases is one standard atmosphere. Combination of this work with previous structural studies leads to a value for the heat of formation of CrO2Cl2 (g) at 298 K of + 518.2 (±2) kJ/mole.  相似文献   

15.
We present three experiments which serve to identify carbon and proton sidechain resonances in 13C-labeled proteins. The first is an improvement on the previously published H(C)CH-COSY experiment and comprises the application of gradients for coherence selection and a reduction in the phase cycle. The second experiment is a new (H)CCH-COSY with two carbon dimensions. The (H)CCH-COSY presents several advantages over the H(C)CH-COSY experiment in terms of better sensitivity, improved resolution and easier identification of amino acid spins systems. The third experiment is a 2D proton-edited (H)C(C)H-COSY that allows suppression of methylene resonances. All three HCCH-COSY experiments show good sensitivity and excellent solvent suppression. The 2D version can be acquired in as little as 45 minutes and the 3D versions acquired overnight. The experiments are demonstrated on a 13C-labeled sample of the second PDZ domain from human phosphatase PTP1E in H2O solution.  相似文献   

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In this report we present the full-length cDNA and deduced 587 amino acid sequence of a putative rat intestinal Na+/dicarboxylate cotransporter. It shows sequence and structural similarity to a rabbit renal Na+/dicarboxylate cotransporter. An unexpected fining was the presence of a C-terminal transmembrane region that is homologous with an 87 amino acid hydrophobic region of a rat intestinal mucin, M2. Mucin-related sequences in transporter proteins have not been described before.  相似文献   

18.
A participation of nonopiate peptide brain systems in the mechanism of individual pain sensation was studied. The experiments were carried out on rats of two inbred strains, Fischer-344 and WAG/G, which exhibit different threshold of thermal pain sensation. The action of nonopiate oligopeptides (substance P, bradykinin, and thiroliberin) on the latent period of tail immersion from hot water was studied. It was found that significant analgesic action of substance P, bradykinin, and thiroliberin is more pronounced in rats more sensitive to thermal stimuli (WAG/G). The rats with reduced thermal sensitivity (Fischer-344) are shown to be insensitive to analgesic action of substance P, bradykinin, and thiroliberin.  相似文献   

19.
A murine monoclonal antibody, CP.B8, specific for the extracellular portion of the human common gamma (gammac) chain, and its Fab fragment are shown to block the binding of IL-2 to COS-7 cells transfected with the cDNA for the full-length IL-2 receptor beta (IL-2Rbeta) and gammac chains, components which together comprise the intermediate affinity IL-2 receptor (IL-2R) expressed on the surface of resting T cells, NK cells, and on certain intestinal epithelial cells. To investigate the mechanism of this inhibition, the extracellular portions of the IL-2Rbeta and gammac chains were expressed and purified, and their interactions with each other and with IL-2 were studied by gel filtration and by surface plasmon resonance (SPR). By gel filtration, a stable ternary complex was formed by association of the three proteins, while no stable binary complexes were detected between any two of the three proteins. By SPR analysis, IL-2 was shown to associate rapidly with IL-2Rbeta, forming a binary complex with an equilibrium dissociation constant (Kd) of 800 nM, which permitted subsequent association of the gammac chain. Dissociation of the IL-2/IL-2Rbeta/gammac chain complex was significantly slower than dissociation of the IL-2/IL-2Rbeta complex. Using these model systems, we tested the ability of mAb CP.B8 to inhibit the association of the gammac chain with IL-2 and IL-2Rbeta. By gel filtration, mAb CP.B8 formed a stable complex with the gammac chain, preventing its association with IL-2 and IL-2Rbeta. MAb CP.B8 was also capable of dissociating the gammac chain already complexed with IL-2 and IL-2Rbeta. SPR analysis confirmed these findings and showed, in addition, that the Fab fragment of CP.B8 was also capable of inhibiting the association of the gammac chain with the IL-2/IL-2Rbeta complex. We conclude that mAb CP.B8 blocks the second step in the formation of the intermediate affinity IL-2R on the surface of transfected COS-7 cells by binding at or close to a region on the gammac chain that is involved in contact with IL-2 and/or IL-2Rbeta.  相似文献   

20.
1. The present study shows the effects of imipramine in a single dose (10 mg kg(-1), p.o.) or following repeated (14 days, twice a day) treatment on the level of mRNA coding for D2 dopamine receptors in the rat caudate putamen (CP). Repeated administration of imipramine resulted in the increase of the level of mRNA coding for D2 dopamine receptors. 2. Radioligand binding studies with the D2 receptor agonist, [3H]-N-0437, indicated, that following imipramine administration, the affinity of the agonist for the D2 dopamine receptor significantly increased, though without any alterations in the Bmax. 3. Pharmacological manipulations (by use of forskolin, GppNHp and quinpirole) of the cyclic AMP generating system, ex vivo following administration of imipramine indicated that an up-regulation of factors inhibiting cyclic GMP formation takes place. 4. Most probably it is the D2 dopamine receptor which undergoes functional up-regulation, resulting from the enhancement of its biosynthesis.  相似文献   

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