focal thickening of alveolar membranes capillary congestion pulmonary oedema intra-alveolar haemorrhage interstitial neutrophil infiltration intra-alveolar neutrophil infiltration % expression Ki-67 % expression TUNEL test % expression p21 % expression p16 % expression p27 % expression cyclin B % expression cyclin D1 % expression cyclin E Chi-Square 33,523 21,803 18,236 28,149 31,234 19,196 32,011 36,001 36,042 32,825 33,272 31,454 30,130 32,874   P value ,000 ,001 ,003 ,000 ,000 ,002 ,000 ,000 ,000 ,000 ,000 ,000 ,000 ,000

Table 2: Comparisons of the median values of all variables with the non-parametric Kruskal-Wallis test.