ABSTRACT
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.
ABSTRACT
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.
ABSTRACT
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.
ABSTRACT
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 explore the effect of L-arginine (L-Arg) on the arrhythmia induced by ischemia/reperfusion (IR) of the right coronary artery in rabbits. METHODS: 48 healthy adult rabbits were divided into 4 groups (n=12 of each) randomly: IRa group (120 min reperfusion after 30 min ischemia), IRb group (120 min reperfusion after 120 min ischemia), IRa+L-Arg group and IRb+L-Arg group. I/R model was established by occluding and loosening the root of the right coronary artery in rabbits. The changes of ECG and arrhythmia were recorded and graded. RESULTS: ① The longer time of IR was, the higher the score of the arrhythmia was found. The incidence of atrial-ventricular block (AVB), sinus-atrial block (SAB), even sinus arrest were detected and aggravated gradually. ② The incidence of AVB was decreased and from Ⅲ?→Ⅱ?→Ⅰ? markedly, some of sinus and atrial arrhythmia were transformed into sinus rhythm gradually, and all of the arrhythmia scores in IRa group were decreased significantly as compared with the same time phases of IRb group (P
ABSTRACT
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 .
ABSTRACT
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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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.