Takeo Kusumoto

Quantitative determination of bacterial endotoxin in middle ear effusions by chromogenic substrate method.

It is known that bacterial endotoxin on the outer surface of most gram-negative bacteria (GNB) is not only biologically active material, but also the modulator of the immune response. The earlier experiment documented that the endotoxin of killed Haemophilus influenzae was responsible for induction of chronic otitis media with effusion (OME). Recent study by DeMaria et al. determined the endotoxin of human middle ear effusion (MEE) by means of limulus amebocyte lysate assay. It was concluded the endotoxin was present in a high percentage of the effusion in human tympanic cavities. The present study was undertaken to quantitatively determine the endotoxin in human MEE by use of chromogenic substrate technique which is more sensitive and accurate than limulus assay. Sixty samples of mucoid and serous effusion were subjected to chromogenic substrate method. It was revealed that the mucoid effusion showed a significantly high level of endotoxin at 282 pg/ml in average, though the serous effusion contained only 35.9 pg/ml. It is assumed that the bacterial endotoxin may greatly contribute to the pathogenesis of otitis media with mucoid effusion.

Experimental Studies on Immunogenesis of Otitis Media with Effusion

In order to investigate otitis media with effusion from the systemic perspective, we have studied histological reactions of the mucous membrane in the both middle ears in the sensitized animals. Guinea pigs were initially immunized by injection of BSA conjugated with alum (BSA-alum) into unilateral tympanic cavity. The second challenge of BSA-alum was performed on the seventh day after primary sensitization under an appropriate schedule. The guinea pigs were sacrificed for histological examination at 3 days after the second administration. Histological changes of the middle ear mucosa in the sensitized ear were characterized by hypertrophy of mucosa with fibrosis. Numerous mononuclear cells also existed. In non-sensitized ear (opposite side), the changes were edema of the mucosa showing mild proliferation of fibroblast and vasodilation. Mainly mononuclear cells were scattered. It was noted that these reactions were weaker than those of the sensitized ear.

Malignant fibrous histiocytoma in a maxillary cavity 20 years after surgery and radiation therapy; A case report.

Malignant fibrous histiocytoma is rarely found in the head and neck.A 65-year-old man, who had been treated for right maxillary cancer with surgery and irradiation in 1963, presented with a tumor 40×30×25mm in the right maxillary cavity. This tumor was histologically diagnoed as malignant fibrous hstiocytoma showing a typical storiform pattern. The tumor was removed successfully with a LASER knife. The patient remains well without recurrence.This case was a so-called postirradiation malignant fibrous histiocytoma.

Clinical evaluation of IAP (Immunosuppressive acidic protein) in the serum of patients with malignant tumors of head and neck--with special reference to prognosis and immunological parameters.

The serum levels of IAP in patients with tumors of the head and neck were determined by single radial immunodiffusion. It was previously reported that the IAP level in these patients was commonly higher than normal. Statistical analysis of 58 patients revealed that the increase of IAP corresponded not only to the clinical stage of the tumor, but also to the probability of tumor recurrence. In addition, it was apparent that the IAP was significantly related to the PPD skin reaction representing delayed hypersensitivity and T-cell population capable of E-rosette formation.The evidence suggests that the determination of serum IAP is useful in understanding the immune defense of hosts against tumors.