Table 4.

Studies utilizing microarray technology to study COPD

Investigator	Microarray type	Species/Sample size	Summary/Key findings	Normalization procedure
	Number of genes	Type of tissue		Replications per data point
Koike et al.45	cDNA 450 genes	Rats AM	cDNA microarray analysis of gene expression in rat alveolar macrophages in response to organic extract of diesel exhausts particles.	G.I was normalized to the housekeeping G.I 2 replicates
Yamanaka et al.46	cDNA 18.432 genes	Human AEC	Gene expression profiles of human small airway epithelial cells treated with low doses of 14- and 16-membered macrolides.	G.I was normalized to the housekeeping G.I 3 replicates
Fuke et al.47	cDNA 77 genes	30 patients Lung tissue specimens	Chemokines in bronchiolar epithelium in the development of chronic obstructive pulmonary disease.	Signal normalized to a given gene transcript 3 replicates
Vuillemenot et al.48	Oligonucleotide 12.000 genes	10 mice Lung tissue specimens	Lymphoid tissue and emphysema in the lungs of transgenic mice inducibly expressing tumor necrosis factor-alpha.	Signal normalized to internal control 2 replicates
Hackett et al.50	cDNA 4.600 genes	22 individuals AEC	Variability of antioxidant-related gene expression in the airway epithelium of cigarette smokers.	Mean hybridization intensities of all probe sets on each array were scaled to an arbitrary, fixed level / 2 replicates
Morris et al.52	Oligonucleotide 6.500 genes	Mice Lung tissue samples	Loss of integrin alpha (v) beta6-mediated TGF-beta activation causes MMP-12-dependent emphysema.	Mean hybridization intensities of all probe sets on each array were scaled to an arbitrary, fixed level / 2 replicates
Golpon et al.53	Oligonucleotide 6.500 genes	Human/mice Lung tissue samples	HOX genes in human lung: altered expression in primary pulmonary hypertension and emphysema.	Gene expression levels normalized by a scaling factor multiplied to the average of differences of probe pairs/ 3 replicates

Abbreviations: AEC: Airway Epithelial Cells, AM: Alveolar Macrophages, COPD: Chronic Obstructive Pulmonary Disease, G.I: Gene Intensity, TGF-b: Transforming Growth Factor-beta, MMP: Metalloproteinase