Both paranasal and middle ear cavities are surrounded by bony walls and are lined with upper respiratory mucosae. Thus it can be worthwhile to compare the biochemical and cytological characteristics of the fluids in these cavities, and this gives valuable information to help us to understand the pathogenesis of
otitis media with effusion. The fluids in the
otitis media with serous effusion (OME-S),
otitis media with mucoid effusion (OME-M) and acute
otitis media (OMA) were sampled for the middle ear diseases, and those in postoperative maxillary
cyst (
POMC) and acutely aggravated chronic
maxillary sinusitis (CMS) were chosen for maxillary sinus group. LDH (
lactate dehydrogenase). ALP (
alkaline phosphatase), CHO (total
cholesterol), LDH
isozymes and ALP
isozymes of these effusions were assayed and the results of each group were compared. Coincidently, through smear samples of these effusions, infiltrating cell count, cell differential count and
cholesterol crystals were observed microscopically. LDH activity of the fluids was extremely higher than those of the serum in all diseases. The LDH activity ratios to serum were CMS greater than or equal to OMA greater than or equal to OME-M greater than
POMC greater than OME-S in order of activity. LDH
isozyme analysis showed higher
LDH 4 and 5 than LDH 1 and 2 in all diseases. ALP activity ratios to serum were OME-S greater than or equal to OMA greater than OME-M much greater than
POMC greater than or equal to CMS in order of activity. Middle ear diseases manifested higher ALP activities than
maxillary diseases. CHO ratios to serum were POMS greater than OME-M greater than or equal to OME-S greater than CMS greater than or equal to OMA in order of quantity. This result agreed with the frequencies of
cholesterol crystallization of these fluids. The fluids of OME-M showed mild infiltration of cells, and cell differentiations were polymorphonuclear leucocyte greater than lymphocyte much greater than macrophage much greater than epithelial cell in order of cell numbers. There were few infiltrating cells in the fluids of OME-S and differentiations were lymphocyte greater than or equal to polymorphonuclear greater than or equal to macrophage in order of numbers. There were a few cells but were many cell debris in the fluids of
POMC, and cells were polymorphonuclear much greater than macrophage greater than lymphocyte in order of cell count.