title: [Comparison between diffuse interstitial pneumonia of unknown etiology and primary pulmonary hypertension--concept of pulmonary connective tissue disease (PCTD)].
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D005260:Female; D006801:Humans; D006976:Hypertension, Pulmonary / Q000150:complications / Q000453:epidemiology*; D007564:Japan; D008297:Male; D008875:Middle Aged; D008947:Mixed Connective Tissue Disease; D011658:Pulmonary Fibrosis / Q000150:complications / Q000453:epidemiology*