Hideaki Kita

Interleukin-8 Secretion of Human Epithelial and Monocytic Cell Lines Induced by Middle Ear Pathogens

Otitis media with effusion (OME) is one of the most common diseases in children. Alloiococcus otitidis, a new Gram‐positive bacterial species, was isolated from the middle ear fluid of children with OME; however, the pathogenic role of this bacteria is yet unknown. In this study, the ability of cultured epithelial cell lines (Hep‐2 and Hela) and monocytic cell lines (THP‐1 and U 937) to secrete chemokine interleukin‐8 (IL‐8) in response to the A. otitidis organism and three bacterial organisms mainly detected from middle ear fluid in OME, and bacterial cell components was investigated. When stimulated with four viable bacterial cells, epithelial cells and monocytes secreted IL‐8 in a time‐dependent manner. The monocytes produced significantly higher levels of IL‐8 than the epithelial cells. Compared with that by viable bacterial cells, IL‐8 secretion by stimulated epithelial cells and monocytes was reduced when the bacteria were heated and treated with glutaraldehyde. With bacterial stimulations, cell treatment of interferon‐gamma caused monocytes to increase the induction of IL‐8 production, however, the induction of monocyte differentiation caused monocytes to reduce the induction of IL‐8 production. Furthermore, epithelial cells and monocytes stimulated by four viable bacterial organisms physically separated from cultured cells reduced the induction of IL‐8 compared with directly stimulated cells, and monocytes stimulated with soluble extracts prepared from A. otitidis organisms produced IL‐8 in a dose‐dependent manner. These results suggest that part of the IL‐8 stimulation of the A. otitidis organism may exist in a diffusable factor released by the bacteria or soluble components of the bacteria itself.

Cytokine and Chemokine Induction Using Cell Wall Component and Toxin Derived from Gram-Positive Bacteria in the Rat Middle Ear

Lipoteichoic acid (LTA) is one of the components present within the cell wall layer of most gram-positive bacteria. It plays an important role in the initiation and progression of bacterial infection. In this study, we performed a rat middle ear and nasal perfusion with LTA purified from two different gram-positive bacterial species. Using ELISA and RT-PCR, the production and mRNA expression of rat chemokine, GRO/CINC-1, proinflammatory cytokine, TNF-alpha, in rat middle ear lavage and mucosa were investigated. GRO/CINC-1 in middle ear lavage was produced by stimulation of LTA in a time-dependent fashion; however, TNF-alpha production into the lavage was not detectable using ELISA assay. The mRNA expressions of GRO/CINC-1 and TNF-alpha in the middle ear mucosa were both induced after LTA and exotoxin exposures. The expression of IL-10 mRNA was also induced after 6 h of LTA and exotoxin exposures. The profile of the production of GRO/CINC-1 and TNF-alpha in rat nasal lavage was similar to that in the middle ear; however, the mRNA expressions of GRO/CINC-1, TNF-alpha and IL-10 in the nasal mucosa were different from those in the middle ear mucosa. These results suggest that the cell wall component and exotoxin of gram-positive bacteria can induce several cytokines in vivo and play an important role in the initiation of the inflammatory cascade in the middle ear.

Effect of radiotherapy on the levels of secretory immunoglobulin A against indigenous and virulent streptococci

It is well known that the frequency of upper respiratory infection is clinically increased after radiotherapy of the head and neck region. This study found higher antibacterial secretory immunoglobulin A (S-IgA) activity against three indigenous streptococci (Streptococcus mitis, S. salivarius, and S. sanguis I) and S. pneumoniae in patients who had undergone radiation therapy of the head and neck region than in control subjects. This showed no relation to the extent of the radiation field. Compared with before radiotherapy, the S-IgA titer against S. pneumoniae and its ratio to the activities against the indigenous streptococci were significantly higher in patients with fully irradiated major salivary glands. These results indicated that the radiotherapy promoted the antigen-specific S-IgA production of virulent streptococci in most patients with head and neck cancer, even more than 6 months after radiotherapy. The resulting altered balance in the S-IgA system of normal indigenous streptococci may also impair the ability to maintain the stable bacterial interference between normal indigenous and virulent streptococci in the oropharyngeal cavity.

Neurofibromatosis with a Hematoma in a Left Parotic Lesion; A Case Report.

We present the case report of hematoma in a left parotic lesion in a neurofibromatosis patient.A 17-year-old man with neurofibromatosis VIII was admitted to our hospital. He complained of a soft mass which had been enlarging over the past few hours in a left parotic lesion. Computed tomography showed an enhanced area and aspiration yielded a bloody fluid. Therefore we diagnosed a sudden enlargement of hematoma and we decided to perform an operation to stop the bleeding. Bleeding was seen on the surface of the neurofibroma and we stopped the bleeding with sheets of hemostatic collagen fleece (Avitene sheet®). There has been no rebleeding since the surgery.

Pericutaneous Endoscopic Gastrostomy for Patients with Head and Neck Tumors.

Pericutaneous endoscopic gastrostomy (PEG) was initially introduced in 1980, and has been applied to feed patients with cerebrovascular diseases.Head and neck tumors and operations for such diseases often cause swallowing problems. Gastric tube insertion has been the most common method to resolve such conditions. However, several disadvantages such as necessity of frequent exchange of the tube, and gastroesophageal refiux have been reported. Intravenous hyper-alimentation is also a common strategy to feed patients. However, infections sometimes occur.We report here, our findings using PEG for patients with head and neck tumors pre- or postoperatively. We recommend PEG as a useful method to provide good nutrition to patients with swallowing disturbance.

Basal Cell Adenocarcinoma of the Submandibular Gland. A Rare Case of Malignancy of the Maj or Salivary Gland.

Basal cell adenocarcinoma, a new type of malignant tumor, was added to the classification of a salivary gland tumor by WHO in 1991. Most cases develop in major salivary glands, especially parotid glands.We report here a case of basal cell adenocarcinoma which developed in the submandibular gland of a 52 year-old man. A pathological diagnosis was based upon Haematoxylin-Eosin staining and immunohistochemistry. The specimen was obtained from total resection of the submandibular gland and upper neck dissection. The patient has survived for 3 years after operation without any signs of local recurrence of regional or distant lymph node metastasis.Clitical points at pathological diagnosis were also discussed.

Silent Thyroiditis after Head and Neck Surgery; A Case Report.

Silent thyroiditis is a transient form of hyperthyroidism characterized by a painless, nontender thyroid gland, elevated blood levels of thyroxine (T4) and triiodothyronine (T3), a low radioactive technesium uptake, and spontaneously resolving hyperthyroidism.We report a case of silent thyroiditis after head and neck surgery. Total laryngectomy and right hemithyroidectomy was performed on a 67-year old man with a diagnosis of recurrent laryngeal carcinoma. After this surgery, the patient had symptoms of thyrotoxicosis: hypertension, hyperglycemia, palpitation, tremor and weight loss. Silent thyroiditis was diagnosed on the basis of both the clinical course and the laboratory data: low uptake of radioactive technesium, and elevated blood levels of T3 and T4. We treated him with β-blocker and insulin. The symptoms disappeared within one month after the operation. This case suggests that silent thyroiditis can be a post-operative complication of head and neck surgery.