ABSTRACT
In clinical practice, we have found that cognitive impairment frequently occurs in chronic obstructive pulmonary disease (COPD) patients, but little is known about its pathophysiological mechanism. Given that brain-derived neurotrophic factor (BDNF) is affected by many factors such as smoking, infection, hypoperfusion and hypoxia, the present study was to explore the expression of BDNF in COPD rats. The rat COPD model was established by passive smoking and intratracheal instillation of lipopolysaccharide (LPS). Rats with the same age and gender ratios were divided into 4 groups: the control group (n = 6), the smoking group (n = 6), the LPS group (n = 6) and the smoking + LPS group (n = 6, COPD model). Level of BDNF in serum was measured by ELISA. And the expression of BDNF in the hippocampus was assessed using the immunohistochemistry and image analysis. The results showed that BDNF in the hippocampus and serum significantly increased in the smoking, LPS and smoking + LPS groups, compared to that in the control group. However, the expression of BDNF was less in the smoking + LPS group than that in the smoking or LPS group both in the hippocampus and serum. In conclusion, the expression of BDNF in the hippocampus and serum is highly increased in the COPD group. Smoking and intratracheal instillation of LPS induce the increase of BDNF level in the hippocampus and serum.
Subject(s)
Animals , Female , Male , Rats , Brain-Derived Neurotrophic Factor , Blood , Metabolism , Disease Models, Animal , Hippocampus , Metabolism , Lipopolysaccharides , Pulmonary Disease, Chronic Obstructive , Metabolism , Rats, Sprague-Dawley , Tobacco Smoke PollutionABSTRACT
Two lab-scale expanded granular sludge bed reactors were operated using granular sludge and river sediments as seed sludge respectively, through gradually lowering down the inner pH values, acid-tolerant methanogenic granular sludge with good methanogenic activity were acquired and formed. Two EGSB reactors could be operated steadily under the condition of pH 5.8～6.2, and their volumetric loading rates were about 5.5～7.5 kg COD/(m3/d), the COD removal efficiencies were about 90%. The granular sludges taken from two reactors could maintain relatively higher methanogenic activity under low pH, and the relative activities of the granular could be 51.78% and 55.6% of the value with the condition of pH 7.0 when pH was 5.5. Studies on the diameter distribution, settling velocities, concentrations of different metal elements and microbiological characteristics of these acid-tolerant granular sludges were also conducted.