AIM: To study the mechanism of the inhibitory effect of human polymorphonuclear leukocytes (PMN) on the production of tumor necrosis factor-? (TNF-?) in U937 cells. METHODS: PMA differentiated U937 cells were cocultured with PMN in the presence of lipopolysaccharide. Sodium azide was added in the culture. The supernatants of cell culture were collected and TNF-? was assayed with ELISA. RESULTS:The inhibitory effect of PMN on the production of TNF-? in U937 cells was observed. Sodium azide restored the TNF-? production in U937 cells/PMN coculture to the extent of 45% in concentration of about 10～15 ?mol/L. These concentrations of sodium azide did not affect TNF-? production by U937 cells. The restoration effect of sodium azide on PMN inhibition was not related to blocking of myeloperoxidase (MPO) activity. The MPO inhibitors 3-amino-1,2,4,-triazole and 4-aminobenzoyl hydrazide had few effect on PMN inhibition. CONCLUSION: These results indicated that PMN inhibition depended on the cell-cell interactions. Sodium azide may be a useful reagent for further studying this mechanism.

Since the endotoxic fever is mediated essentially by endogenous pyrogen (EP), we have examined the possibility that the central cAMP is involved in the mechanism of biphasic fever induced by endotoxin, as in the case of biphasic fever induced by EP. The results showed that administration of endotoxin in rabbits elicited typical biphasic fever. The fluctuation of concentration of cAMP in cerebrospinal fluid (CSF) paralleled with the change of the rectal temperature, similar to that of the bipbasic fever caused by EP. Raised level of cAMP in plasma was observed only in the first phase. The cAMP concentration in CSF correlated positively with the febrile response. The correlation of cAMP levels in CSF and plasma was observed only in the first phase but not in all the febrilic periods. These findings indicated that the mechanism of endotoxic biphasic fever is associated with the Change of central cAMP. Content. The raised level of cAMP in CSF during fever is likely to represent the biosynthsis in brain regions. However, the possibility that the raised cAMP in plasma enters CSF in the first phase is not excluded.

The signals of body temperature from 4 different febrile patterns were sampled for power spectral analysis. The results showed that the spectrums had no difference between their distribution in frequency domain, only a low frequency peak has been seen. The values of the power spectrum varied directly to the intensity of the febrile responses. A high degree of relationship was found between the power spectral density and thermal response index (TRI).

A new method of calculating fractal dimension of short-term heart rate variability signals is presented. The method is based on wavelet transform and filter banks. The implementation of the method is: First of all we pick-up the fractal component from HRV signals using wavelet transform. Next, we estimate the power spectrum distribution of fractal component using auto-regressive model, and we estimate parameter 7 using the least square method. Finally according to formula D = 2- (gamma-1)/2 estimate fractal dimension of HRV signal. To validate the stability and reliability of the proposed method, using fractional brown movement simulate 24 fractal signals that fractal value is 1.6 to validate, the result shows that the method has stability and reliability.
Algorithms ; Electrocardiography ; Fourier Analysis ; Fractals ; Heart Rate ; physiology ; Humans ; Least-Squares Analysis ; Nonlinear Dynamics ; Signal Processing, Computer-Assisted

Objective To evaluate the prevalence of aspirin resistance in old-aged patients with cerebral infarction and to analyze the mechanisms and clinical predictors of aspirin resistance. Methods 300 old-aged patients with cerebra] infarction were selected and the platelet aggregation ratio was determined by nephelometry with CHRONO-LOG PA-meter. And some information of these patients, such as age, sex, smoking, taking non-steroid anti-inflammatory drug (NSAD)or proton pump inhibitor (PPI), obesity, coronary artery disease (CAD), peripheral vascular disease, hyperpiesia, diabetes and hyperlipemia were recorded. Results 112 cases (37.33%) were aspirin sensitiveness, 108 cases(36.0%) were aspirin semi-resistance and 80 cases (26.67%) were aspirin resistance. These cases were divided into two groups. One was aspirin sensitive (AS) group, which included 112 patients of aspirin sensitiveness. The other was aspirin resistant (AR) group, which consisted of 188 patients of aspirin semi-resistance and aspirin resistance. The prevalence of CAD, hypercho]esteremia and RBC count in AR group was higher than that in AS group The percentage of patients who took NSAD, PPI and smoke in AR group was also higher than that in AS group. Conclusion Aspirin resistance existed in old-aged patients with cerebral infarction to great extent, and which was correlated with CAD, hypercholesteremia, smoking, RBC count, taking NSAD and PPI.

Objective To acknowledge the incidence of sharp- appliance wound of trainee nurses and explore the relative countermeasures. Methods A retrospective investigation was carried out in 140 trainee nurses of grade 2003 about the incidence of sharp- appliance wounds, then the corresponding pre-ventive countermeasures were formulated and applied in the clinical practice of trainee nurses of grade 2004 and the incidence of sharp- appliance wound was investigated and compared with the results of those grade 2003.X2 test was adopted. Results The incidence rate of sharp- appliance wound in trainee nurses of grade 2004 was obviously lower than that of grade 2003. Conclusions Due to the weak safety con-sciousness, unfamiliar with operation and lack of clinical experience, the sharp- appliance wound will easily occur among trainee nurses. If the relative professional preventive knowledge is strengthened, the opera-tional procedures are observed strictly and the sense of responsibility of tutor teachers is facilitated, then the incidence of sharp- appliance wound of trainee nurses will drop.

Objective To investigate the relativity between morning blood pressure surge (MBPS) and carotid atheresclerosis. Methods Noninvasive ambulatory blood pressure monitor (ABPM) was per-formed on 97 patients with the first and second stage of essential hypertension and according the ABPM re-suits, the patients were classified into MP+ group (31 cases) and MP-group (66 cases). In the meantime, the carotid intima-media thickness (IMT) and the carotid atheresclerotic plaque was examined by the color Doppler ultrasound. The relationship among MBPS, carotid atherosclerotic plaque and IMT was analyzed.Results The IMT of common carotid artery (CCA), carotid artery bifurcation (CAB)and internal carotid artery (ICA) in MP+ group was significantly higher than that in MP- group [ (1.02±0.36)mm vs (0.86±0.22) mm, (1.14±0.39 ) mm vs(0.96±0.26) mm, (0.94±0.30 )mm vs ( 0.82±0.18 mm ), P<0.05 ]. The ratio of carotid atherosclerotie plaque in MP+ group was significantly higher than that in MP- group (64.5% vs 42.4%,P<0.05). Conclusions The MBPS is related to carotid atheroselerotie plaque and the carotid IMT. The MBPS may accelerate the forming and developing of atherosclerosis.

Objective To investigate the variations of serum levels of visfatin in pregnant women with different types of glucose intolerance and the associations with insulin resistance.metabolic parameters and newborn birth weight.Methods Totally,120 pregnant women in late trimester were divided into 3 groups according to the results of 50 g glucose challenge test(GCT)and 75 g oral glucose tolerance test:GDM group(n=45),GCT(+)group(n=20),and NGT group(n=55).Fasting levels of visfatin,insulin,total cholestrol and triglyceride were measured and the newborn birth weight was recorded.Results The serum visfatin level was significantly elevated in GDM group compared with the NGT group[(374.9±23.1)ng/ml vs(308.9±16.8)ng/ml,P＜0.05],but no significant difference was shown when compared with the GET(+)group[(346.5±23.1)ng/ml].Furthermore,serum visfatin levels had no relationship with insulin resistance,metabolic parameter and newbom birth weight.Conclusions Visfatin is elevated in GDM women and closely related with GDM,but not with insulin resistance,metabolic parameters and newborn birth weight.

Objective To study the relevance of peripheral blood mononuclear cell (PBMC) IL- 18 level in patients with chronic HBV infection and the activity of chronic hepatitis B as well as the ex- tent of hepatic tissue inflammation. Methods Flow cytometry was applied to measuring IL-18 level in PBMCs isolated from 147 patients with HBV infection; meanwhile, 22 cases with hepatitis B patients or HBV carriers underwent needling biopsy of liver for liver histopathologic examination. Results IL- 18 level was rising step by step in moderate chronic hepatitis, severe chronic hepatitis, chronic serious hepatitis and acute fatal hepatitis. Elevation of IL-18 level was correlative to the activity of hepatic tis- sue inflammation. Conclusion The expression level of IL-18 is different in various HBV infection states, which is correlative to the activity of chronic hepatitis B as well as the extent of hepatic tissue inflammation. Therefore, IL-18 may be used as an important index of evaluating therapeutic effect and prognosis.

Objective To get the information about the infection condition of blood in voluntary donors in Fuling District from 2001 to 2007, so as to take measures to improve blood quality and ensure blood safety.Methods Serum ALT was detected with Reitman-Frankel assay, and HBsAg, anti-HCV, anti-HIV and anti-TP were detected with ELISA.Results A total of 72 868 serum samples from blood donors were detected, in which 5 512 (7.56%) were positive. The positive rates of HBsAg, anti-HCV, anti-HIV and anti-TP were 3.09%, 0.48%, 0.07% and 1.27% respectively, and the abnormality rate of ALT was 2.73%. There was statistical difference of positive rate among various years (from 2001 to 2007).Conclusion The positive rate of blood in voluntary donors decreases year by year. HBsAg was the highest (1.16%), followed by ALT (2.73%), anti-TP (1.27%), anti-HCV and anti-HIV. It suggests that blood quality monitoring should be strengthed to assure blood safety.