By Aebi [34]. An aliquot of lung homogenate was mixed with 10 times
By Aebi [34]. An aliquot of lung homogenate was mixed with 10 times its volume of PBSFollowing Acadesine supplier euthanasia of the animals with a high dose of pentobarbital (240 mg/kg/0.7 ml, i.p.), the lungs were fixed in situ with 10 neutral-buffered formalin for about 2 hr at a pressure of 20 mm of water. The lungs, along with the attached heart, were surgically removed through a vertical incision along the thorax, and fixed in 10 neutral-buffered formalin for an additional 48 hr. After excising any extrapulmonary structures with the help of a scalpel, the lungs were cut into pieces of a size suitable for histological processing, put though a standard embedding procedure in paraffin, sectioned on a microtome, and stained with H E. The sections where then examined for evidence of inflammation with the help of a light microscope.Bhavsar et al. Journal of Biomedical Science 2010, 17(Suppl 1):S19 http://www.jbiomedsci.com/content/17/S1/SPage 4 ofDetermination of lung injuryThe presence of lung injury in the tissue sections was graded using the scale described by Szarka et al. [37]. The following scoring values were used: 0 = no reaction in the alveolar walls, 1 = diffuse reaction in the alveolar walls but without thickening of the interstitium, 2 = diffuse PubMed ID:https://www.ncbi.nlm.nih.gov/pubmed/28607003 presence of inflammatory cells in the alveolar walls with a slight thickening of the interstitium, 3 = moderate interstitial thickening accompanied by inflammatory cell infiltrates, and 4 = interstitial thickening involving more than one-half of the microscopic field. Results were expressed as the average of the values from 50 microscopic fields.Immunocytochemistry of TNFRexamined, and the results were expressed as the mean number of TUNEL-positive cells per HPF.Statistical analysisThe experimental results are expressed as mean ?standard error of the mean (S.E.M.) for n = 6. A significant difference between control and treatment groups was determined by Student’s t-test followed by one-way analysis of variance (ANOVA) and Newman-Keuls multiple-range test. A P value 0.05 was taken as an indication of a statistically significant difference.ResultsEffects of LPS and TAU-LPS on indices of lung oxidative stressCytocentrifuged lung preparations were fixed with ethanol and permeated with an alcohol-acetic acid (2:1) mixture. Endogenous peroxidase activity was quenched with 0.3 H2 O 2 and nonspecific binding was blocked with goat serum (Vector Laboratories, Inc., Burlingame, CA). After an incubation with anti-mouse TNFR1 polyclonal antibody (Stressgen, Victoria, BC, Canada) at room temperature for 30 min, and a rinsing with PBS pH 7.4, the sample was successively incubated with biotinylated goat anti-rabbit antibody or rabbit anti-rat antibody (Stressgen, Victoria, BC, Canada) at room temperature for 1 hr, and with ABC reagent (Vector Laboratories, Inc., Burlingame, VT) for 1 hr, prior to staining with 3,3′-diaminobenzidine substrate in the dark, and counterstaining with methyl green. The slides were examined under a light microscope at 400x magnification for the presence of macrophages stained in brown. For comparative purposes, a negative control sample that had not been incubated with TNFR1 primary antiserum was also examined. The results were expressed as the number of macrophages staining for TNFR1 in a group of 200 cells counted in the same section. The number of macrophages staining for TNFR1 was reported as a percentage of the total number of macrophages examined.TUNEL staining for apoptosisEvidenc.
