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1.
Although cardiac function is depressed during endotoxic shock, it remains controversial whether the ventricular contractility and structure are altered during sepsis. To resolve this issue, rats were subjected to polymicrobial sepsis by cecal ligation and puncture (CLP). At 2, 5, and 10 h after CLP (i.e., the early, hyperdynamic stage of sepsis) or 20 h after CLP (the late, hypodynamic stage of sepsis, based on the depressed tissue perfusion), in vivo left ventricular contractility parameters such as maximal rate of the left ventricular pressure increase (+dP/dtmax) and decrease (-dP/dtmax), maximal rate of "pressure-normalized" change in ventricular pressure (dP/dtmax/P), and ventricular peak systemic pressure were determined using a Digi-Med Heart Performance Analyzer. In additional groups of animals, ultrastructure of the cardiac muscle in the left ventricle was examined at 5, 10, or 20 h after CLP, using a transmission electron microscope. The results indicate that +dP/dtmax and dP/dtmax/P increased significantly at 2-10 h after CLP. The values of -dP/dtmax and ventricular peak systemic pressure increased significantly at 2 and 5 h after the onset of sepsis, respectively. These in vivo ventricular contractility parameters, however, were not significantly different from shams at 20 h after CLP. Ultrastructural examination showed that enlarged T-tubules were prominent during the hyperdynamic stage of sepsis, which was correlated with the increased cardiac contractility. Although focal and moderate hypertrophy as well as expanded intermyocyte junctions could be observed occasionally, myocardial cells did not appear to be compromised at 20 h after CLP. Thus, the transition from the hyperdynamic to hypodynamic circulation during sepsis does not appear to be due to any depression in myocardial function because cardiac contractility and structure are not compromised even during the late, hypodynamic stage of sepsis. However, further investigation is required to determine whether cardiac function is depressed at the terminal stage of polymicrobial sepsis.  相似文献   

2.
Certain MHC class I molecules on target cells are known to inhibit the cytotoxic action of NK cells. By using monoclonal antibody (mAb) Cho-1, we have found inhibitory non-MHC class I cell surface molecules that are noncovalently-associated with 200 kDa and 40 kDa antigens. Poly I-C-induced rat NK cells were not cytotoxic to rat fetus-derived fibroblast WFB cell line. In contrast, NK cells were cytotoxic to H-ras oncogene-induced transformants of WFB, W14 and W31. FACS analysis indicated that mAb Cho-1 reacts with WFB, but not with W14 and W31 cells. Thus, this antigen may disappear concomitantly with cell growth and transformation. Cho-1 antigens were also expressed on other NK-resistant lines, such as mouse BALB3T3 fibroblast, EL-4 lymphoma and human fibroblast HEPM. However, they were not expressed on NK-sensitive mouse YAC-1 and H-ras transformant (Brash) of BALB3T3 cells. Furthermore, treatment of target cells with IFN-gamma clearly induced the cell surface expression of Cho-1 antigens, and conferred a resistance to NK cytolysis on target cells. These data strongly suggest that Cho-1 antigen expression may correlate with target cell susceptibility to NK cells. Indeed, treatment of NK-resistant WFB as well as HEPM cells with F(ab')2 fragments of mAb Cho-1 resulted in the acquisition of susceptibility to NK cytolysis. Cho-1 antigens may be novel molecules that regulate the NK resistance of cells.  相似文献   

3.
The release of certain cytokines, e.g. tumour necrosis factor (TNF)-alpha, in the amniotic fluid has been suggested to be a cause of preterm birth. The predisposition to excessive liberation of cytokines from peripheral leukocytes has been shown to depend partly on the individual's HLA-DR genotype. The HLA-DR1 and -DR3 alleles have previously been reported as being associated with a TNF-alpha high responder status and have also been associated with unexplained recurrent spontaneous abortions. In the present study, HLA-DR typing was performed in 10 women who had experienced recurrent very early preterm births resulting in perinatal death, or late spontaneous abortions under a clinical picture resembling that traditionally attributed to cervical incompetence. All patients had had at least one mid-trimester miscarriage in spite of the insertion of a cervical cerclage. Nine out of 10 (90%) patients had the HLA-DR phenotypes DR1 and/or DR3 compared with 37% in the background population (P < 0.005). The results suggest that HLA-DR-associated immunological factors might play a part in recurrent late spontaneous abortions and extremely preterm births under a cervical incompetence-like picture, at least in the subset of cases not treatable by cervical cerclage.  相似文献   

4.
5.
Intravenous immunoglobulins (IVIG) are increasingly used for treatment of inflammatory diseases, and the modulation of complement may contribute to some of its beneficial effects. IVIG may bind C1q and activated C3 and C4, and enhance inactivation of C3b. We have previously shown that IVIG inhibited complement-mediated lysis solely via its Fc part through interaction with the classical pathway. In the present study we have investigated whole IVIG (Octagam, and Sandoglobulin) and the monomer, dimer and multimer fractions of Octagam with respect to complement activation in serum and inhibition of complement lysis of red cells. The isolated fractions were found to be stable, homogeneous (monomer, dimer or multimer) and pure (virtually only IgG). Both whole IVIG and its fractions significantly activated complement in serum and inhibited hemolysis compared with human albumin. These effects were most pronounced in the monomer, less in the multimer and least in the dimer fraction. The complement activation was shown to be mediated through the classical pathway since formation of C1rs-C1inh complexes and C4bc were increased, in contrast to Bb. Surprisingly, heat aggregation of Octagam was not followed by a corresponding increase in complement activation, as would be expected, unless it was dialysed before heating, suggesting that it is stabilized to avoid excess activation. In conclusion, the results support the hypothesis that IVIG causes a mild activation of complement in vitro. We suggest that this effect may contribute to the complement inhibitory properties of IVIG by diverting complement deposition from the target to the fluid phase.  相似文献   

6.
The permanent pancreas carcinoma cell line, PCI-24, was developed in order to analyse cytokine regulation on pancreas carcinoma and lymphokine-activated killer (LAK) cell interaction. PCI cells expressed ICAM-1 and HLA-ABC, but not HLA-DR antigens. PCI cells showed augmented ICAM-1 and HLA-ABC expression when incubated with interferon gamma (IFN gamma) and tumour necrosis factor alpha. A similar but weak augmentary effect on the HLA-ABC and ICAM-1 surface expression was seen with interleukin-1 beta treatment. Natural attachment of LAK to PCI cells was augmented by recombinant IFN gamma in close association with ICAM-1 up-regulation on PCI cells. In addition, natural attachment was significantly inhibited by anti-LFA-1 and anti-ICAM-1 antibody treatments. Cytotoxicity of the LAK cells against PCI cells was also significantly inhibited with the same treatment. Thus, the attachment of LAK cells to PCI cells through LFA-1/ICAM-1 molecules appeared to be essential for the cytotoxicity for PCI cells. Pretreatment of PCI cells, but not of LAK cells, with IFN gamma or other cytokines resulted in a decrease of susceptibility for LAK cell cytotoxicity. The decreased susceptibility inversely correlated with HLA-ABC expression on the PCI cells. The collective evidence indicates that, although LAK cell attachment to pancreas carcinoma cells through the LFA-1/ICAM-1 molecule is augmented by IFN gamma, IFN gamma treatment of pancreas carcinoma cells reduces LAK cell cytotoxicity possibly through an increase in HLA-ABC or a regulation of molecules closely associated to HLA-ABC expression.  相似文献   

7.
The effect of eccentric one-legged exercise on natural killer (NK) cell activity was studied in eight healthy males. To distinguish between local and systemic effects, blood samples were collected from veins in the exercising leg and resting arm. However, the results did not significantly differ between the leg and arm. To eliminate diurnal variations, the results were compared with a control group that did not exercise but had blood samples collected at the same time points. In the exercising group, plasma creatine kinase increased progressively during and up to 4 days after exercise. The percentage of CD16+ NK cells increased during exercise, which was paralleled by an increase in the NK cell activity per fixed number of blood mononuclear cells. The NK cell activity on a per NK cell basis did not change. The percentage of CD3+, CD4+, CD8+, CD19+, and CD14+ cells did not change significantly during exercise. The present study thus showed that eccentric exercise with a relatively small muscle mass (1 quadriceps femoris muscle) causes systemic effects on NK cells. It is suggested that the increase in plasma epinephrine during eccentric exercise is responsible for the observed increase in the percentage of CD16+ cells.  相似文献   

8.
A time-resolved fluorometric assay for the simultaneous measurement of natural killer cell activity against three different lanthanide diethylenetriaminopentaacetate (LaDTPA) labelled target cell lines is described. The target cell line K-562 was labelled with SmDTPA, the cell line Molt with TbDTPA and the cell line Raji with EuDTPA. After co-incubation of the three target cell lines with effector cells the fluorescence of the lanthanides released from the lysed target cells was measured in an enhancer solution in which they formed highly fluorescent complexes. It was possible to differentiate the specific release from the three target cell lines because the emission lines of the europium, samarium and terbium complexes formed in the enhancer solution are well separated from each other. The autofluorescence from culture media supplemented with serum was avoided by the use of time-resolved fluorometry. The results show that applying fluorometry based on the combination of spectral and temporal resolution to natural killer cell assays, makes possible the simultaneous determination of lysis in up to three target cell lines in complex culture medium.  相似文献   

9.
Pentoxifylline used in the treatment of vascular diseases has also some immunological effects. Among of these effects the influence of pentoxifylline on the natural killer cell activity was studied. In in vitro experiments the human natural killer cell cytotoxicity was examined in the presence of pentoxifylline. In our clinical trial we investigated the topic whether this drug has an immunomodulatory effect while administering it for different periods. The natural cytotoxicity of macroangiopathic patients treated with pentoxifylline was compared with the values of healthy controls and patients suffering from vascular disease and obtaining no pentoxifylline therapy. Sixty two macroangiopathic patients and twenty healthy controls were investigated altogether. In the in vitro natural killer cell reaction we found that the pentoxifylline was able to suppress the cytotoxicity at any time of the reaction. The influence of pentoxifylline on natural killer cell activity was neither due to the expression of intercellular adhesion molecule-1, nor to the alteration of membrane fluidity. However, this drug significantly (p < 0.05) decreases the apoptosis of target cells. The natural killer cell activity of patients with chronic pentoxifylline therapy lasting for more than a year was proved to be significantly (p < 0.005) lower. The presence of vascular disease does not influence the natural killer activity by itself. Concluding our results we can state that the suppressing effect of pentoxifylline on natural killer cell activity needs to be taken into consideration in case of clinical diseases where this drug is administered chronically.  相似文献   

10.
OBJECTIVE: To study the role of chromosomal aberration in the causation of recurrent spontaneous abortion (RSA) in Chinese population. METHODS: A total of 514 Chinese couples with 2 or more spontaneous abortions at less than 24 weeks of gestation were included. For each proband, a minimum of 13 metaphases were analyzed by G-banding. Additional cells (usually 50-100 cells) were screened when mosaicism was suspected. Chi 2 test was used to compare the number and frequency of couples with and without balanced translocation with respect to whether liveborn was present or absent. Chi 2 test for trend was used to show whether a correlation existed between the occurrence of balanced translocation and the number of spontaneous abortions at ascertainment. RESULTS: The overall incidence of chromosome anomaly was 51 out of 514 (9.92%). Chi 2 test for trend analysis showed that the chance of one member of a couple being a balanced carrier increased with the number of spontaneous abortions. The chance of finding translocation in couples with liveborn was higher than that in couples without liveborn, but the difference was not statistically significant. We also found that pericentric inversion 9 did not play an important role in the causation of recurrent abortion. CONCLUSIONS: Cytogenetic analysis is indicated in couples with 2 or more spontaneous abortions and the chance of finding chromosomal aberration increases with the number of abortions at the time of ascertainment.  相似文献   

11.
In the current study, we investigated whether the naive, poly I:C or interleukin-2 (IL-2)-induced natural killer (NK)/lymphokine-activated killer (LAK) cells use perforin and/or Fas ligand (FasL) to mediated cytotoxicity. We correlated these findings with the ability of mice to reject syngeneic Fas+ and Fas- tumor cells either spontaneously or after IL-2 treatment. The spontaneous NK-cell-mediated cytotoxicity was primarily perforin based, whereas the poly I:C and IL-2-induced NK/LAK activity was both FasL and perforin dependent. L1210 Fas+ tumor targets were more sensitive than L1210 Fas- targets to poly I:C and IL-2-induced cytotoxicity in wild-type, gld/gld, and perforin knockout mice. When L1210 Fas+ and Fas- tumor cells were injected subcutaneously (sc) or intraperitoneally into syngeneic mice, Fas- tumor cells caused mortality earlier than Fas+ tumor cells. Also, approximately 20% of the mice injected sc with L1210 Fas+ tumor cells survived the challenge(>60 days), whereas all mice injected similarly with L1210 Fas- tumor cells died. When immunotherapy using IL-2 (10,000 U, three times/d for a week, followed by once/d for an additional week) was attempted in mice injected sc with tumor cells, IL-2 treatment was very effective against mice bearing L1210 Fas+ (40% survival) but not L1210 Fas- (0% survival) tumors. These data correlated with the finding that the LAK cells from IL-2-injected mice caused increased cytotoxicity against L1210 Fas+ when compared with L1210 Fas- targets. Also, L1210 Fas+ tumor-bearing mice showed increased tumor-specific cytotoxic T lymphocyte (CTL) activity when compared with those bearing L1210 Fas- tumor cells. Together our studies show for the first time that expression of Fas on tumor targets makes them more immunogenic as well as susceptible to CTL- and IL-2-induced LAK activity. The Fas+ tumor cells are also more responsive to immunotherapy with IL-2.  相似文献   

12.
The suppression of natural killer (NK) cell cytotoxicity by footshock stress can be attenuated by opioid antagonists, implicating endogenous opioids in its mediation. A stress paradigm that includes NK suppression that is not blocked by the opioid antagonist naltrexone is reported. This stress paradigm is also shown to cause analgesia and elevated plasma corticosterone levels that are not attenuated by naltrexone. In the first experiment, a significant suppression of NK cell cytotoxicity after forced swimming was demonstrated in Fischer 344 rats treated with either saline or naltrexone, compared with nonstressed controls. Significantly higher corticosterone levels were evident in both stressed groups. In the second experiment, the same stress paradigm was shown to cause significant analgesia in the tail-flick test. It is concluded that opioids need not always be involved in the suppression of NK cell cytotoxicity by stress. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

13.
The present study examines the expression and involvement of cAMP-dependent protein kinase (PKA) isozymes in cAMP-induced inhibition of natural killer (NK) cell-mediated cytotoxicity. Rat interleukin-2-activated NK cells express the PKA alpha-isoforms RIalpha, RIIalpha, and Calpha and contain both PKA type I and type II. Prostaglandin E2, forskolin, and cAMP analogs all inhibit NK cell lysis of major histocompatibility complex class I mismatched allogeneic lymphocytes as well as of standard tumor target cells. Specific involvement of PKA in the cAMP-induced inhibition of NK cell cytotoxicity is demonstrated by the ability of a cAMP antagonist, (Rp)-8-Br-adenosine 3',5'-cyclic monophosphorothioate, to reverse the inhibitory effect of complementary cAMP agonist (Sp)-8-Br-adenosine 3',5'-cyclic monophosphorothioate. Furthermore, the use of cAMP analog pairs selective for either PKA isozyme (PKA type I or PKA type II), shows a preferential involvement of the PKA type I isozyme, indicating that PKA type I is necessary and sufficient to completely abolish killer activatory signaling leading to NK cell cytotoxicity. Finally, combined treatment with phorbol ester and ionomycin maintains NK cell cytotoxicity and eliminates the cAMP-mediated inhibition, demonstrating that protein kinase C and Ca2+-dependent events stimulate the cytolytic activity of NK cells at a site distal to the site of cAMP/PKA action.  相似文献   

14.
Anesthesia (Avertin, halothane, isoflurane, ether, or ketamine/xylazan) of mice inhibits subsequent stimulation of splenic natural killer cell (NK) cytotoxicity by interferon (IFN) treatment either in vitro and in vivo. The current data demonstrate (a) in vitro depletion of CD8+ cells from mononuclear splenocytes of anesthetized mice restored the ability of NK cells to respond in vitro to IFN stimulation and (b) coincubation of CD8+ splenocytes from anesthetized mice with CD8- splenocytes of naive mice resulted in a significant reduction of the IFN-induced stimulation of NK activity in the coculture. These results suggest that anesthesia induces CD8+ cells that suppress stimulation of NK cytotoxicity by IFN.  相似文献   

15.
We investigated natural killer (NK) cell activity in an animal model of ethanol-induced immunoglobulin A (IgA) nephropathy. Two groups, of 10 rats each, received a continuous intragastric infusion of liquid diet through a permanent cannula for 6 weeks. The alcoholic group was infused additionally with intragastric ethanol, representing from 32% to 40% of the caloric requirement. The group of control rats received an isocaloric diet supplemented with glucose instead of alcohol. IgA nephropathy was observed in all the alcoholic rats but in none of the controls. NK cell activity was investigated in the two groups by measuring the cytotoxicity of spleen cells using the chromium release method. NK cell activity was found to be significantly increased in the alcoholic rats. In view of the known modulation of IgA synthesis by NK cells, we suggest that increased NK cell activity may be a contributing factor to the high levels of circulating IgA seen in IgA nephropathy secondary to chronic alcohol consumption.  相似文献   

16.
PURPOSE: to demonstrate and document TIPSS-induced changes of the perfusion pattern of the liver with special reference to several rheologic, morphologic, functional and biochemical parameters. Our analysis was based on a study in 100 consecutive cases. PATIENTS AND METHODS: Evaluation and assessment of the following parameters before and within a 30-day post TIPSS period: portosystemic gradient; morphologic delineation of the portal circulation; invasive scintigraphic determination of the portal perfusion fraction (PPF) and the total liver perfusion (GLP); transcatheter intraarterial flow change measurement; serum levels of albumin and bilirubin; assessment of hepatic encephalopathy by appropriate testing; assessment of recurrent variceal bleeding RESULTS: by TIPSS variceal filling was widely reduced; as assessed morphologically and rheologically portal liver perfusion was significantly reduced. However, there was immediate onset of compensated liver perfusion by increased arterial inflow. Total liver perfusion was not significantly altered. In TIPSS portal decompression was readily achieved with reduction of the portosystemic gradient from an average of 24 mmHg to 10.5 mmHg. In our series we could not demonstrate an increased incidence of hepatic encephalopathy during the 30-day post TIPSS period. Bilirubin levels were significantly increased after TIPSS from 2.45 to 2.61 mg/dl (p = 0.0067), while albumin levels were not altered. Early mortality was 4% and early re-bleeding rate 3%, respectively. CONCLUSION: the concept of TIPSS represents an individually calibrated H-shunt. The significant reduction of post TIPSS portal perfusion appears to be compensated by increased arterial inflow. This is reflected by invasive flow measurement results and by the clinical results. Letality of TIPSS is low.  相似文献   

17.
We classified CD56+ CD3- natural killer (NK) cells into CD2- CD56dim (CD2- NK), CD2+ CD56dim (CD2+ NK) and CD2+ CD56bright populations, and investigated mainly functional differences between the former two populations. CD2- and CD2+ NK cells were the same in their morphology and several surface molecules except for CD2. The percentages of CD2- NK cells in total NK cells were higher in the cord blood and marrow than in the peripheral blood of adults or children. Freshly isolated CD2- NK cells had CD2 in the cytoplasm, and gradually expressed it on the surface upon incubation with interleukin-2 (IL-2). These results demonstrated that CD2 is an antigen which appears on the surface during the maturation of NK cells. The granule-mediated cytotoxicities, which are mainly performed by the perforin molecule, of CD2+ NK cells against K562 and Daudi cells were higher than those of CD2- NK cells, and they were inhibited to the levels of CD2- NK cells by the addition of a blocking anti-CD2 monoclonal antibody (mAb). Fas ligand (FasL) mRNA was expressed in freshly isolated CD2+ NK cells but not in the CD2- NK cells. Neither freshly isolated NK populations showed FasL-mediated cytotoxicity, and only CD2+ NK cells lysed Fas-transfected targets after the 24-hr incubation with IL-2. Based on these results, CD2- NK cells have already developed granule-mediated cytotoxicity equal to that of CD2+ NK cells except for the CD2-associated activity, but they, unlike CD2+ NK cells, totally lack FasL-mediated cytotoxicity. These findings suggest that FasL-mediated cytotoxicity may be acquired at more mature stages of NK-cell maturation than granule-mediated cytotoxicity.  相似文献   

18.
A slime factor produced by Staphylococcus epidermidis was a complex glycoconjugate extracted by the phenol extraction method. The potential stimulatory or inhibitory capacity of the phenol-extracted slime (PES) was tested on human natural killer cell cytotoxic activity. Various concentrations of the PES preparation were incubated with the effector cells 30 min before and during the assay period. The PES factor inhibited natural killer cell cytotoxic activity at a concentration of 250 micrograms/ml and at higher concentrations (p < 0.05). The inhibition of natural killer cell cytotoxic activity may probably be related to the complex composition of the slime substance.  相似文献   

19.
The establishment of the human placenta in early pregnancy is characterized by the presence of large numbers of natural killer (NK) cells within the maternal decidua in close proximity to the fetally-derived invading extravillous trophoblast which expresses at least two HLA class I molecules, HLA-G and HLA-C. These NK cells have an unusual phenotype, CD56(bright) CD16, distinguishing them from adult peripheral blood NK cells. They may control key events in trophoblast migration and therefore placentation. Human NK cells in peripheral blood express receptors for polymorphic HLA class I molecules. This family of receptors, known as killer cell inhibitory receptors (KIR), are expressed on overlapping subsets of NK cells to give an NK cell repertoire which differs between individuals. Using a panel of monoclonal antibodies to several members of the KIR family and analysis by flow cytometry, we have found that KIR are expressed by decidual NK cells. There is variation in both the percentage of cells expressing a particular receptor and the density of receptor expression between decidual NK cells from different individuals. Comparison of NK cells from decidua and peripheral blood of the same individual showed that NK cells from these two different locations express different repertoires of KIR. Receptors are present in individuals who do not possess the relevant class I ligand, raising the possibility that these NK receptors may be involved in recognition of the allogeneic fetus by the mother at the implantation site.  相似文献   

20.
The treatment of a 14-membered ring macrolide, clarithromycin (CAM), prolongs the survival time of patients with unresectable nonsmall cell lung cancer, and improves the host factor. As we previously reported, one of the underlying mechanisms is that the treatment of CAM increases the bioactivity of interleukin-12 (IL-12). In the present study, we administered CAM to murine lung cancer treatment models with Lewis lung carcinoma and to 18 patients with unresectable non-small lung cancer whose anticancer treatment had been terminated. The timing of CAM administration was examined and the time course of NK activity was measured. In the murine lung cancer treatment models, administration of CAM 7 days after anticancer chemotherapy more strongly inhibited the tumor growth and more rapidly and significantly increased NK activity, compared to the concomitant use of CAM with an anticancer chemotherapy. In humans, the NK activity which had decreased after anticancer treatment, tended to be increased after one month of treatment with CAM (p = 0.06). One month of treatment with CAM significantly increased the NK activity (p < 0.05) of the following subjects: patients with stage III in the clinical stages, patients with squamous cell carcinoma, patients who had received radiotherapy alone as pretreatment therapy, and patients whose pretreatment therapy effect was partial response (PR). We conjectured that increasing NK activity was one of the underlying mechanisms of the macrobiotic effect of CAM. CAM was especially effective for patients in the early clinical stages and patients who responded well to pretreatment therapy. Murine lung cancer models showed that non-concomitant use of CAM with anticancer chemotherapy was more effective.  相似文献   

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