Tomohiko Takasaki

Serum antibodies to human herpesvirus 7, human herpesvirus 6 and cytomegalovirus in patients with idiopathic facial nerve palsy or sudden deafness

The aetiology of idiopathic facial nerve palsy (Bells palsy) and sudden deafness are not known, although viruses have been suspected as a cause of them. We investigated the relationship between Bells palsy or sudden deafness, and reactivation of cytomegalovirus, human herpesvirus 6 (HHV-6) and 7 (HHV-7). Paired sera were collected from 22 patients with Bells palsy and 24 patients with sudden deafness. IgG antibody titres to HHV-7 were increased in one patient with Bells palsy. IgG antibody titres to HHV-6 were increased in one patient with Bells palsy and two with sudden deafness. IgG antibody titres to cytomegalovirus were increased in one patient with sudden deafness. Titres of the three viral antibodies were not increased simultaneously in any patients. These viruses may contribute to the development of Bells palsy or sudden deafness in some cases. It is, however, unlikely that these viruses are the main cause of Bells palsy and sudden deafness in the majority of patients.

Recurrent laryngeal papillomatosis developing into laryngeal carcinoma with human papilloma virus (HPV) type 18 : a case report

We report a case of recurrent laryngeal papillomatosis which developed into laryngeal squamous cell carcinoma 11 years after the first diagnosis. Interestingly, we could identify HPV type 18 DNA in the carcinoma tissue using the polymerase chain reaction (PCR). Other known risk factors of irradiation, smoking, exposure to chemical agents, or a hereditary tendency to malignant tumours were not present in this case. Our finding suggests that HPV type 18 is another aetiological agent for laryngeal carcinoma.

Human antibodies responsible for binding inhibition and polymerization inhibition of human immunodeficiency virus type 1 reverse transcriptase

Using a solid-phase non-radioisotopic (non-RI) reverse transcriptase (RT) assay, antibodies inhibiting human immunodeficiency virus type 1 (HIV-1) RT activity (RTI antibody) were investigated for their ability to inhibit binding of RT to a template-primer and DNA polymerization. The RTI antibody inhibited the binding of RT to the template-primer (BI antibody), and directly reacted with the RT-template-primer complex and inhibited enzymatic activity (PI antibody). The RTI antibody interfered with formation of the RT-template-primer complex suggesting that it recognized the antigenic site involved in template-primer binding of RT molecules. Since deoxynucleotide triphosphates (dNTPs) blocked inhibition of the RT activity by the PI antibody, the antigenic site recognized by the PI antibody may be closely related to the dNTP binding site. The seropositivities of the BI and PI antibodies were 84.6% and 91.2%, respectively, in HIV-1-infected individuals; healthy individuals, HTLV-I-positive individuals, autoimmune disease patients and leukemia patients were all seronegative. No significant correlation of residual RT activities was observed when BI and PI antibodies were compared (r = 0.688). It is possible that the epitopes recognized by the BI antibody differs from those recognized by the PI antibody. The assays described are able to detect BI and PI antibodies in the sera of HIV-1-infected individuals.

Malignant buccal hemangioendothelioma - A case report.

Malignant hemangioendothelioma of the buccal region was diagnosed. Light microscopy with hematoxylin and eosin stain, reticulin stain, periodic acid Schiff stain and factor VIII-associated protein stain by the peroxidase antiperoxidase technique showed different characteristics in different areas of the same tumor, such as hemangioendotheliomatous and hemangiopericytomatous areas with fibrosis. It was thought that this tumor was an immature vascular tumor, and it was called a “cellular hemangioma”.