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 31 毫秒
1.
Regulation of ICAM-1 Expression in Mouse Macrophages   总被引:2,自引:0,他引:2  
In a mouse model of silica (SI) induced lung injury, SI exposure increases expression of intercellular adhesion molecule-1 (ICAM-1) on lung (alveolar/interstitial) macrophages and alveolar type II epithelial cells. To investigate the regulation of SI induced ICAM-1 expression on mouse macrophages, freshly isolated macrophages (alveolar, peritoneal) and macrophage cell lines (MH-S, RAW 264.7) were evaluated for ICAM-1 expression elicited by the particle silica ( quartz; 20 g/ml; 6 g/cm2) or the inflammatory cytokine, TNF (20 ng/ml). TNF significantly increased ICAM-1 expression in all cell types whereas SI elicited an increase in peritoneal macrophages (PM) and the cell line, MH-S. This pattern of increased expression was confirmed by immunocytochemistry. To investigate the regulation of ICAM-1 expression, PM were incubated with SI, TNF or media concomitantly with anti-TNF antibody, the antioxidant, NAC, or the iNOS synthase inhibitor, L-NAME. Both anti-TNF and NAC, but not L-NAME, inhibited elicited (TNF, SI) as well as constitutive (media) ICAM-1 expression. These data demonstrate that both inflammatory cytokines and inorganic particles can increase ICAM-1 expression on mouse macrophages and that this expression is mediated, in part, by TNF and reactive oxygen species.  相似文献   

2.
Promastigote culture forms of the log growth phase ofLeishamania donovani stock LRC L 51 were investigated for expression of cell-surface carbohydrate-binding sites using 15 types of a chemically glycosylated enzyme termed neoglycoenzyme. Carbohydrate conjugation and coupling yield were kept constant to ensure that the type of carbohydrate moiety, was the only variable feature of the applied tools. Para-aminophenyl derivatives of the following carbohydrate residues were used for the glycosylation of -galactosidase fromEscherichia coli: -d-lactose, -d-thiogalactose, -d-mannose, -l-rhamnose, -d-N-acetylgalactosamine, -d-N-acetylgalactosamine, -d-N-acetylgalactosamine, -d-N-acetylgalactosamine, -d-N-acetylglucosamine, the - and -glucosides maltose and cellobiose, -d-xylose, -d-mannose-6-phosphate, the -galactoside melibiose, -l-fucose, and -d-glucuronic acid as well as sialic acid. Only melibiose, fucose, and glucuronic acid showed no binding affinity for the cultured flagellates; this served as an internal control reaction to exclude any binding to the linker group. This result demonstrates that many but not all sugar types can be recognized by appropriate receptor structure(s) on the surface of the promastigoteLeishmania. Transformation of the binding data for neoglycoenzymes exposing lactose, mannose, rhamnose, andN-acetylated hexose residues, which was carried out to obtain the dissociation constants and to estimate the number of binding sites at saturation, revealedK D values of around 100mm and around 104 binding sites for the polyvalent ligands.  相似文献   

3.
The most complex unconditioned reflexes of aim and freedom, discovered by I. P. Pavlov, are compared with the competence drive and the motivation of the resistance to coercion, respectively, described by contemporary ethologists. On the basis of the unconditioned reflex of purpose, conditioned reflexes were developed in which positive emotions arising in connection with the perfection of a skill, irrespective of its pragmatic significance at a given moment, serve as the reinforcement. The unconditioned reflex of freedom is regarded as a phylogenetic precursor of the will, and its acute extinction as the physiological mechanism of hypnosis. It was demonstrated experimentally that the appearance of the state of animal hypnosis (immobilization catatonia) in rabbits is accompanied by the predominance of electrical activity and heat production in the right hemisphere, i. e., by symptoms which are found in hypnosis in man.Translated from Zhurnal Vysshei Nervnoi Deyatel'nosti imeni I. P. Pavlova, Vol. 39, No. 3, pp. 415–420, May–June, 1989.  相似文献   

4.
Sections of bovine ovaries fixed in Bouin's fluid or methanol-acetic acid and embedded in paraffin were incubated with chicken polyclonal antibodies to HPLC-purified zona glycoproteins ZP3 and ZP3. Oocytes of primordial follicles as well as of primary follicles showed weak labelling with anti-ZP3 and anti-ZP3. No immunostaining could be observed in the follicle cells. The ZP of primary follicles displayed distinct immunoreactivity for both ZP3 and ZP3. In secondary follicles, distinct labelling with anti-ZP3 and weak labelling with anti-ZP3 could be seen in the oocyte. The ZP showed immunoreactivity with antibodies to ZP3 and ZP3. Both antibodies labelled single follicle cells. In tertiary follicles, the oocytes were weakly labelled with anti-ZP3 and anti-ZP3. Some granulosa cells showed staining for ZP3 and ZP3. The ZP displayed strong immunoreactivity for ZP3 and ZP3. Cells of the corona radiata were strongly immunopositive for ZP3 and ZP3. Similar histotopography of immunoreactive cells could be seen in preovulatory follicles. The characteristic pattern observed for the distribution of ZP3 and ZP3 strongly suggests that in the porcine ovary both the oocyte and the follicle cells contribute to the synthesis of the ZP, perhaps in sequence.  相似文献   

5.
Summary Three pig-tailed macaques were trained to select (match) from a pair of colored images that which they had seen (sample) and responded to 5–15 s previously. The anterior commissure (AC) and/or its radiation, various loci in basal ganglia, hippocampal formation and control areas, (splenium of corpus callosum, precentral gyrus, insular cortex), totalling 40 loci, were each tetanized for 4 s during presentation of the sample image, during the delay period, or when the monkey was required to select the matching image. For several loci in the hippocampal formation tetanization at any phase of the task reduced matching to chance levels and gave evidence of electrical after-discharge; but other comparable hippocampal loci had little or no effect. Response to sample or match stimuli were absent during tetanization of basal ganglia or anterior commissure. When finally made, upon cessation of tetanization, responses were equally correct for basal ganglia and control sites, but for AC were at chance levels.  相似文献   

6.
Summary The present study gives the results of a comparison of the recorded and true tibia-calcaneal angles in 17 normal subjects and in 14 patients with abnormally hypoextensible non contracting triceps. 1. For a minimal passive torque, the difference between true and recorded angles varied considerably from one individual to another. The means and ranges for the two groups were respectively: –8 (+7, –21) and –7 (+5, –20). 2. When the passive torque increased as a result of slow passive lengthening of the muscle, the true curve was steeper than the recorded one, owing to differences between the two angle measurements. For each of the two groups the differences in means and ranges were respectively: 6 (0, +13.5) and 8 (3, 12). 3. Subjects made isometric voluntary contractions of the triceps surae at fixed angles which corresponded to step by step muscle lengthening. The resulting true curve was much steeper than the recorded curve. The differences in means and ranges were: 7 (1.5, +15) in children of the two groups and respectively 3 (0, +9) and 12 (10, 14) in adults of the two groups. The present results show that this methodology was the only reliable way of correctly obtaining passive and active torque-angle curves, measuring differences between subjects, appreciating the effects of treatments and these by ascertaining whether or not trophic muscle regulation was defective.  相似文献   

7.
Summary Earlier studies concerning 1 gene regulation by the 4 protein, the major regulatory protein of herpes simplex virus 1 (HSV-1), in stably transformed cell lines, reported conflicting results, i.e., 4 protein positively regulated the 1 gB gene in 4/gB cells, while it negatively regulated the 1 gD gene in 4/BJ cells. Both cell lines were derived from a common parental cell line 4/c 113 that contains 1 copy of the 4 gene, and the only apparent difference between them was the relative copy number of the gB and gD sequences (1 and 30–50, respectively) resident in the cell genome. We investigated this disparity by constructing a cell line (BA 4) that contains one copy each of the 4 and 1 gD sequences, by fusion of 4/c 113 and BJt cells, containing and expressing respectively 1 copy of the 4 and gD genes. BA 4 cells constitutively expressed both the 4, gD genes inherited from the parental cell lines ( 4/c 113 and BJt). In BA 4 cells the 4 protein positively regulates the gD gene as evidenced from (i) higher levels of gD expression than the parental BJt cells lacking the 4 gene, and (ii) significant decrease in gD expression under conditions that render the 4 protein produced in BA 4 cells non-functional. In addition the 2gG gene contained within the DNA fragment encoding the gD gene, is also expressed in BA 4 cells. On the basis of these data, we propose that gene regulation by the 4 protein is affected by the relative copy number of these genes, resident in the cell genome.  相似文献   

8.
Summary Cortisol-1, 2-H3 was incubated with rat liver homogenate and/or rat liver slices in the presence of a NADPH-generating system. The following metabolites could be identified in adult male rats: -cortol, allo--cortol, 3-allo--cortol, 20-hydroxy-cortisol, 11, 17, 20, 21-tetrahydroxy-5-pregnan-3-one, 3-allotetrahydrocortisol, tetrahydrocortisol, trace amounts of allotetrahydrocortisol and two highly polar metabolites only partly identified. In female rats only tetrahydrocortisol, allotetrahydrocortisol and allodihydrocortisol could be detected in significant amounts.The radioactive metabolites mentioned above were localized and quantitated on paper chromatograms by a 4-radiochromatogram scanner. A nearly perfect correlation was found between these results so obtained and those given by liquid-scintillation counting of each metabolite after its elution from the paper.Part of this work was supported by grant n° 695 of the National Fonds voor Wetenschappelijk Geneeskundig Onderzoek.Stagiair of the Nationaal Fonds voor Wetenschappelijk Onderzoek.  相似文献   

9.
Direct cytotoxicity and absorption analysis were used to detect HLA antigens on man/mouse somatic cell hybrids. Confirmation of the assignment of the Major Histocompatibility Complex to chromosome 6 was obtained. The same series of hybrids were used to study the interaction between HLA and 2m on the cell surface. Results obtained from a series of clones indicated that there was complete independence of expression of HLA and 2m. Human 2m was found to be unnecessary for the normal serological expression of HLA, suggesting that mouse 2m could possibly replace human 2m as a subunit of the HLA molecule. Evidence is presented demonstrating that this is in fact the case. Heteroantisera to human 2m and alloantiserum to HLA-A2 were used, together with complement, to selectively remove the chromosome coding for 2m and HLA from a hybrid clone. Manipulation of the karyotype in this way further confirmed the independence of HLA and 2m on somatic cell hybrids.  相似文献   

10.
Ohne Zusammenfassung1. Vorsitzender der Gesellschaft Deutscher Naturforscher und Ärzte 1956/58Festrede aus Anlaß der Eröffnung der 100. Tagung der Gesellschaft Deutscher Naturforscher und Ärzte, Wiesbaden 28. 9. 58.  相似文献   

11.
Summary A new method for the separation of isoenzymes of-glutamyl-transpeptidase is described, using electrophoresis on acetate cellulose gel and a developing solution composed by-glutamyl-naphthylamide, and a colored diazonium compound.The method permits the separation of up to four different isoenzymes, which we called-GT1,-GT2,-GT3,-GT4, the first two showing an electrophoretic migration similar to that of 1- and 2-globulins and the other two to that of-globulins.The present technique has proved its usefulness in detecting isoenzymes in serum with values of total-glutamyl-transpeptidase higher than 80 U/L.The application of this method in 52 patients with different types of biliary obstruction and hepatocellular damage has shown that it provides new possibilities in differential diagnosis.  相似文献   

12.
Summary Utilization of the anaphylactic reaction for distinguishing tumor antigens from antigens of normal tissues requires the preliminary investigation of 2 problems: 1) how should desensitization against major antigens be performed in order to be sure of its completeness, and 2) how does such desensitization affect the sensitivity of the animal to minor antigens? Experiments were carried out on guinea pigs which were sensitized by mixtures of two antigens (foreign serums, tissue nucleoproteins) mixed in different proportions. It was demonstrated that the desensitizing dose of a major antigen is several times as great as the shocking dose, and therefore that repeated injection is necessary to bring about complete desensitization. This causes a pronounced decrease of the sensitivity to the minor antigen. Therefore it is necessary to increase the dose of the preparation containing the mixture of antigens (for example, a tumor extract) in order to obtain a definite anaphylatic reaction. These findings should be taken into consideration in employing anaphylaxis for the demonstration of antigenic differences between tumors and normal tissues.  相似文献   

13.
During the development of mammalian muscle the -subunit of the nicotinic acetylcholine receptor (AChR) is replaced by the -subunit to produce well-defined alterations in the conductance and gating of the channel. To gain a better unterstanding of the functional role of the and -subunits, we have studied the properties of an AChR channel lacking these subunits. The AChR expressed in Xenopus oocytes injected with the bovine -, and -subunit-specific mRNAs (referred to as -AChR) is unusual in that its channel opens spontaneously at a high frequency in the absence of agonist. From a comparison of the -AChR with complete receptors containing either the or -subunit, we conclude that the and -subunits influence most channel properties, including agonist binding, and are especially important for stabilizing the closed state of the unliganded receptor channel. The -AChR can form when a complete set of four subunit-specific mRNAs is injected. The ease with which it is assembled raises the possibility that the - AChR contributes to some of the variations in receptor properties that occur during development.  相似文献   

14.
Crithidia oncopelti, C. deanei, andC. desouzai are flagellates of the Trypanosomatidae family that present bacterium-like endosymbionts in their cytoplasm. Direct and indirect lectin-gold labeling techniques were used at the electron microscopic level in Lowicryl K4M-embedded cells to demonstrate the presence of intracellular lectin-binding sites. We used the lectinsUlex europaeus I, Griffonia simplicifolia II, Ricinus communis I, Arachis hypogaea, G. simplicifolia I, Wistaria floribunda, Limulus polyphemus, andCanavalia ensiformis, which recognize -l-fucose, - and -N-acetylglucosamine, -galactose and -N-acetylgalactosamine, -galactose, -galactose, -N-acetylgalactosamine, sialic acid and -d-mannose, and -d-glucose residues, respectively. The nucleus was the cellular structure most frequently labeled by the lectins. The Golgi complex was seldom labeled, whereas the endoplasmic reticulum and the flagellar pocket presented a large number of binding sites. Symbionts had their two unit membranes weakly labeled by the different lectins but displayed no labeling of the space between the membranes.  相似文献   

15.
A possible mechanism is proposed for the enhancement/weakening of those cortical signals in the cortex-basal ganglia-thalamus-cortex neural network which induce/do not induce opening of NMDA channels in the spiny neurons of the striatum and which can be regarded as strong/weak in terms of this measure. The mechanism is based on the modulatory influences of dopamine on changes in the efficiency of corticostriatal inputs. In the absence of dopamine, relative increases in the intensity of strong (weak) cortical signals can lead to the induction of long-term potentiation (depression) of corticostriatal synapses. In this case, because of the differently directed influences on thalamic cells of signals passing via strionigral and striopallidal cells, strong signals at the output of the thalamus are weakened, while weak signals are strengthened. Activation of dopamine D1 (D2) receptors on strionigral (striopallidal) neurons may facilitate increases in the extent of long-term potentiation/depression (decreases in the extent of long-term potentiation/depression or induction of long-term potentiation/depression). The consequence of this is that strong signals at the output of the thalamus can be strengthened synergistically, while weak signals cab be weakened synergistically. Background cortical signals evoking tonic release of dopamine in the striatum can decrease strengthening because of weakening of the modulatory influence of dopamine on the modification of corticostriatal synapses.  相似文献   

16.
The cytokines, interferon- (IFN-), tumor necrosis factor- (TNF-rpar;, and interleukin-2 (IL-2) are important endogenous proinflammatory proteins and have been linked to disease activity in multiple sclerosis. In this study, we use flow cytometric methodology to compare the secretion of IFN-, IL-2, and TNF- from peripheral blood-derived T cells of multiple sclerosis patients to the secretion in healthy controls. The percentages of IFN-, IL-2, and TNF- secreting cells are not significantly different between multiple sclerosis patients and controls. However, the TNF- secreting CDS cell percentage is correlated with the IFN- and IL-2 secreting CD3 cell percentages in multiple sclerosis patients. In the controls, only the TNF- secreting CD3 cell percentage is correlated with IFN-. These findings show that correlated secretion of cytokines occurs in multiple sclerosis and suggest that concerted intercytokine interactions may play an important role in the disease.  相似文献   

17.
    
Zusammenfassung Die aus den Fraktionen Hb A1 und Hb A1 hergestellten Globine liefern bei der Stärkegel Hochspannungselektrophorese praktisch identische Peptidketten-Auftrennungen. Die Aufspaltung der Hauptkomponente (Hb A1) des Erwachsenen-Hämoglobins (Hb A) in zwei Fraktionen (Hb A1, Hb A1) kann daher nicht durch eine Separation der- und-Peptidketten des Hämoglobinmoleküls bedingt sein. Vielmehr ist anzunehmen, daß das Molekül von Hb A1 in zwei symmetrische Hälften aufgespalten wird.  相似文献   

18.
Summary From 1978–1986, 63 patients (48–79 years) under coumarin derivatives had to be hospitalized neurosurgically because of intrcranial or intraspinal bleedings. This corresponds to a twelvefold increased risk compared to the untreated people. The male/female ratio was 1.5. At the time of the bleeding there was no true indication for anticoagulation in at least 60% of the patients. 80% with coma on admission died. Only for 2/7 with an intraspinal hemorrhage the outcome was better than paraplegic. Women proved to have a better chance of survival. — There is a need for more concise indications for chronic anticoagulation.

Abkürzungen CT Röntgen-Computertomographie - Cumarine für Cumarinderivate; hier zu 97% Phenprocoumon - ZNS-Blutung nur der Kürze wegen fürbegrifflich korrekt: intrakranielle und intraspinale Blutung Meinem Lehrer, Herrn Dr. med. Czeslaw Andrzejewski, zum 70. Geburtstag gewidmet!  相似文献   

19.
Summary Damage to the anterior limbic and motor regions of the brain cortex results in two types of distribution of degenerated fibers over the brain cortex in dogs. The first lateral type is characterized by a predominant fragmentation of a large number of thick horizontal or diagonal fibers of the lower cortical layers on the lateral surface; the second type, known as medial, by the fragmentation of single slender radial fibers and horizontal fibers of the first cortical layer on the medial surface.The lateral-type degenerated fibers are distributed over the cortex of the sigmoid, presplenial, suprasplenial and ectolateral convolutions (motor, parietal and occipital fields). They are most numerous in the motor (4) and optic (19, 18) areas. The medial-type degeneration is characteristic of the cingulum (gyrus cinguli) (limbic fields).An injury to the anterior and posterior portions of the sigmoid convolution causes a less extensive lateral-type degeneration than an injury to the genual convolution.Presented by Academician V. N. Chernigovskii Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 59, No. 3, pp. 18–22, March, 1965  相似文献   

20.
Summary In 9 adult anaesthetized cats, 22 lumbosacral Renshaw cells recorded with NaCl-filled micropipettes were activated by random stimulation of ventral roots or peripheral nerves. The stimulus patterns had mean rates of 9.5–13 or 20–23 or 45 pulses per second and were pseudo-Poisson; short intervals below ca. 5 ms (except in two cases) were excluded. The Renshaw cell responses were evaluated by two kinds of peristimulus-time histograms (PSTHs). Conventional PSTHs were calculated by averaging the Renshaw cell discharge with respect to all the stimuli in a train. These PSTHs showed an early excitatory response which was often followed by a longer-lasting slight reduction of the discharge probability. These two response components were positively correlated. Conditional PSTHs were determined by averaging the Renshaw cell discharge with respect to the second (test) stimulus in pairs of stimuli which were separated by varied intervals, . The direct effect of the first conditional response was subtracted from the excitation following the second (test) stimulus so as to isolate the effect caused by the second stimulus per se. After such a correction, the effect of the first conditioning stimulus showed pure depression, pure facilitation or mixed facilitation/depression. Analysis of such conditioning curves yielded two time constants of facilitation (ranges: ca. 4–35 ms and 93–102 ms) and two of depression (ranges: ca. 7–25 ms and 50–161 ms). It is concluded that these time constants are compatible with processes of short-term synaptic plasticity known from other synapses. Other processes such as afterhyperpolarization and mutual inhibition probably are of less importance.  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