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The present study was undertaken to investigate the effect of human PMNs on the production of TNF-α by the human peripheral blood mononuclear cells (PBMCs) and to elucidate its tentative mechanism. Human PMNs and PBMCs were isolated from the venous blood of healthy donors by dextran sedimentation and density gradient centrifugation. In the presence of lipopolysaccharide (LPS), PMNs and PBMCs were cocultured at the ratio of 2:1 for 20 h and the concentration of TNF-α in the supernatant was measured by enzyme-linked immunosorbent assay. The binding rate of monocytes with the fluorescein isothiocyanate-labeled LPS (FITC-LPS) and the mean surface fluorescence intensity of monocytes were analyzed by flow cytometry. Results showed that PMNs were capable of inhibiting the TNF-α release from PBMCs (P＜0.05). PMNs suppressed the TNF-α release from PBMCs by 45% on average when PMNs and PBMCs cocultured at the ratio of 2:1. Paraformaldehyde-fixed PMNs still demonstrated the same inhibition (P＜0.05)，which proved that the inhibition was dependent on cell-to-cell contact and suggested that effector molecules responsible for this effect existed on the cell surface of PMNs. In the presence of PMNs, the binding rate of monocytes with the FITC-LPS and the mean surface fluorescence intensity of monocytes were not affected compared with PBMCs alone (P＞0.05). As incubation time was prolonged, the binding of FITC-LPS to monocytes increased (P＜0.05). Thus PMNs did not block the binding of LPS with monocytes. It was concluded that PMNs suppressed the TNF-α release from PBMCs via cell-to-cell interaction. In a cell-contact dependent manner, PMNs might interfere with the signal transduction pathway through which LPS activated PBMCs, thus attenuating the response of PBMCs to LPS and downregulating the TNF-α release.
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AIM and METHODS:To investigate the effect of electrical stimulation of VSA on the firing of thermosensitive neurons in preoptic anterior hypothalamus (POAH), the firing rate of thermosensitive neurons in POAH of 20 New Zealand white rabbits was recorded by using extracellular microelectrode techinque. RESULTS:(1)Electrical stimulation of ventral septal area (VSA) caused a significant increase in firing rate of warm-sensitive neurons in the preoptic area of the anterior hypothalamus(POAH).(2) The firing rate of cold-sensitive neurons was decreased remarkably in the POAH by electrical stimulation of VSA. CONCLUSION:VSA may play a controlling role in the thermoregulation through altering the firing rate of thermosensitive neurons in the POAH.
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AIM: To investigate the details of Th2 cell differentiation in septic mice. METHODS: Experimental septic mice were induced by cecal ligation and puncture (CLP). The exression of CD30 on CD4 +T cells at different time after CLP were estimated by flow cytometry following three-color immunofluorescent staining.RESULTS: CD30 expression on CD4 +T cell was different at each time point. The highest expression was showed at 38 h after CLP and declined later, which matched the changes in mortality of the animals. CONCLUSION: During sepsis, differentiation of Th2 cell changed with the development of sepsis and might be associated with the severity of the disease.
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AIM: The present study was undertaken to explore the effects of ?-MSH on partial biological activities of LPS. METHODS:Colorimetric method was used for the measurement of hydrogen peroxide(H_2O_2) production in mouse peritoneal macrophages, the apoptosis of polymorphonuclear leukocytes(PMNs) and the binding of LPS to monocytes were studied with flow cytometry. RESULTS: It was found that LPS strongly stimulated macrophages to release H_2O_2. When macrophages were cultured with ?-MSH in the presence of LPS, the H_2O_2 release was markedly suppressed (P0.05). In the presence of LPS, however, ?-MSH significantly promoted the apoptosis of PMNs (P
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AIM: To investigate the effect of human polymorphonuclear leukocytes (PMNs) on the release of TNF-? by the human peripheral blood mononuclear cells (PBMCs) and to elucidate its mechanism. METHODS: Human PMNs and PBMCs were isolated from the venous blood of healthy donors by dextran sedimentation and density gradient centrifugation. After the cells were cocultured at the ratio of 2:1 in the presence of lipopolysaccharide (LPS), the concentration of TNF-? in the supernatant was measured by enzyme-linked immunosorbent assay. The binding rate of monocytes with the fluorescein isothiocyanate-labeled LPS (FITC-LPS) and the mean surface fluorescence intensity of monocytes were analyzed by flow cytometry. RESULTS: PMNs do not produce detectable TNF-? in the presence of LPS. PMNs were capable of inhibiting the TNF-? release from PBMCs ( P
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AIM: To explore effects of glycine and polymyxin B mixture (Gly/PMB) on endotoxin-induced acute phase response in vivo . METHODS: Model of acute phase response was reconstructed by endotoxin (ET) in rabbits. Specimens of blood were collected at 1 hour after the highest body temperature. Leukocyte count, serum C-reactive protein and trace element were also detected. RESULTS: Pretreatment of half-dose Gly/PMB significantly inhibited acute phase response induced by ET ( P 0.05). CONCLUSION: These results suggested that glycine enhanced the inhibitory effect of polymyxin B on ET-induced acute phase response. The advantage of glycine and polymyxin B mixture was decreasing dosage and side effects of polymyxin B. [
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AIM: To investigate effects of Retinervus luffae fructus (RLF) on level of serum lipid and body weight in hyperlipidemia rats. METHODS: Thirty-two male SD rats were randomly divided into four groups: control group (A), hyperlipidemia group (B), hyperlipidemia + RLF group (C), RLF group (D). Both group A and C were fed normal diet every day, while group B and group D fed high fat diet. Meanwhile, group C and D were administered with RLF solution at the dose of 10 mL/kg, respectively for 14 days, while group A and B were administered with drinking water. RESULTS: (1) At the end of experiment, a significant reduction was found in the levels of serum total cholesterol (TC) and triglyceride (TG) of group C animals treated with RLF solution; (2) The levels of serum TC of group D was progressively decreased compared to the level of serum TC at the beginning of experiment; (3) The level of high-density lipoprotein cholesterol (HDL-C) of group C remained unaltered 8d after treatment with RLF solution; (4) The body weight in group C was obviously lower than that in group B. CONCLUSION: RLF had an obvious hypolipidemic effect on hyperlipidemia rats. It can inhibit the decrease in the HDL-C and the increase of body weight in rats. [
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AIM and METHODS: To investigate the effect of electrical stimulation of VSA on the firing of thermosensitive neurons in preoptic anterior hypothalamus (POAH), the firing rate of thermosensitive neurons in POAH of 20 New Zealand white rabbits was recorded by using extracellular microelectrode techinque. RESULTS: (1)Electrical stimulation of ventral septal area (VSA) caused a significant increase in firing rate of warm-sensitive neurons in the preoptic area of the anterior hypothalamus(POAH).(2) The firing rate of cold-sensitive neurons was decreased remarkably in the POAH by electrical stimulation of VSA. CONCLUSION: VSA may play a controlling role in the thermoregulation through altering the firing rate of thermosensitive neurons in the POAH .
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AIM and MEfTHODS: To clarify the role of inducible nitric oxide synthase (iNOS) in the regula- tion of blood pressure, in the present study, we examined the effect of aminoguanidine (AG), a selective inhibitor of iNOS on the hemodinamical response of Dahl salt - sensitive (DS) and Dahl salt - resistant (DR) rats to low (0. 3% ) or high (8%) sodium chloride (Nacl) infusion by chronical in vivo hemodynamic experiment, and the effect of NaCl or NaCl plus AG infusion on urinary nitrate (NO3)/nitrite (NO2), the end product of nitric oxide (NO),ex- cretion by Greiss Reaction. Furthermore, NOS activity assay was the dried out to probe the effect of NaCl and AG on calcium - dependent or independent NOS activity in renal tissue. RESULTS:1. High or low NaCl - infused DR rats and low NaCl - infused DS rats have no hemodinamical response to AG, however, the hpertensive effect of high NaCl (8% ) infusion on DS rats were gnatly amplified by co - infusion of AG. 2. Administration of high NaCl signif- icantly elevated the iNOS activity of renal tissue, and greatly increased urinary NO3/NO2 excretion. CONCLUSION: Ihducthle NOS is an important modulator of arterial pressure, especially in case of higher blood pressure.
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This experiment was carried out in 65 New Zealand rabbits. The resultsrevealed that the febrile response and increaed PGE_2 level in cerebrospipel fluid (CSF) were significantly reduced when the calcium-channel-blocking agent (verapamil) wasintravenously injected prior to ET. But, verapamil had no marked effect on the increasedcAMP level in csf during ET-induced fever. It was suggested that most likely this anti-pyretic action was due to the effect on biosynthesis of PGE in hypothalamus, while,cAMP might not be involved in the mechanism of this antipyretic action.
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AIM:To investigate the effects of rhTGF-?1 and TGF-?1 gene transfection on the proliferation of cultured rabbit corneal endothelial cells in vitro.METHODS:Cell growth induced by various concentrations of rhTGF-?1 was determined by MTT proliferation assay.Under the induction of liposomes,recombinant pSecTag2-TGF-?1MP vectors were transferred into the corneal endothelial cells.Morphological changes of transfected cells were observed by HE staining.The expression levels of TGF-?1 were assessed by ELISA.Cell cycle analysis was assessed by flow cytometry.DNA fragment analysis was used to confirm the presence of apoptosis.RESULTS:rhTGF-?1 in concentrations of 5-20 ?g/L showed a significant suppressive effect on the proliferation of corneal endothelial cells,0.5-1 ?g/L had no effect,0.05-0.1 ?g/L facilitated cell growth,as compared with negative controls.The morphous of transfected corneal cells had no significant abnormality compared with normal cells.According to the result of ELISA,the concentration of TGF-?1 in the supernatant was calculated to be(98?3)ng/L.Flow cytometry assay showed that S and G2/M phase of transfected cells decreased significantly compared with that of control group,but the cell cycle recovered normally after adding 10 ?g/L EGF into the culture medium.Agarose electrophoresis didn't show marked ladders in transfected group.CONCLUSION:Effects of rhTGF-?1 on the proliferation of corneal endothelial cells are different with various concentrations.TGF-?1 gene transfection shows suppressive effect on the proliferation of cultured corneal endothelial cells,but does not induce cell apoptosis.EGF is the antagonist of this suppressive effect.
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AIM: To observe the effect of cornus of ficinalis glycosides(COG) ophthalmic solution on the corneal allograft rejection by topical instillation. METHODS: The corneal transplantation model on the closed colony rats was established. The rejection time of all animals was recorded and compared by slit-lamp microscope. The pathologic changes were measured by immunohistochemistry and scanning electron microscope.RESULTS: The histopathological and immunohistochemistry findings showed that the lymphocytes, neovascularity and the expression of ICAM-1 in COG-treated group were significantly fewer than that in control group at 15 d after operation.CONCLUSION: COG ophthalmic solution prevents and suppresses the corneal allograft rejection.