In order to clarify human mucosal and systemic immunity against influenza viral infection, the serum titers of anti-influenza virus-specific nasal secretory IgA and serum IgG and their changes after subcutaneous vaccination were measured in a Japanese healthy adult population in the present study. We recruited 155 healthy adults in 2006, with an average age of 24.1 years (range: 19-60 years). The male-female ratio was 1: 1. Nasopharyngeal lavage fluid and serum specimens were obtained prior to vaccination and a month after subcutaneous vaccination with a trivalent influenza ether split hemagglutinin vaccine of the A (H1N1), A (H3N2) subtypes and type B influenza viruses. Nasopharyngeal lavage fluid specimens were obtained by the nasal spray and aspiration method. The anti-influenza virus-specific IgA titers in the nasopharyngeal lavage fluid and IgG titers in the serum against the A (H1N1), A (H3N2) subtype and type B influenza viruses were measured by ELISA. The anti-influenza virus-specific nasal lavage fluid IgA titers were represented as a ratio to the total IgA titers. About 70% of the subjects had nasal anti-viral IgA against the A (H1N1), A (H3N2) subtype and type B influenza viruses, and almost all had serum anti-viral IgG against the A (H1N1), A (H3N2) subtype and type B viruses. The serum antiviral IgG titers, but not the nasal antiviral IgA titers, were significantly elevated at 1 month after the subcutaneous vaccination. Moreover, the serum antiviral IgG titers were significantly elevated after vaccination only in subjects with low pre-vaccination IgG titers, and not in those with high pre-vaccination IgG titers. The nasal antiviral IgA titers in the subjects of our present study were significantly higher than those in patients with influenza infection reported from our previous study. The presence of nasal anti-influenza virus-specific IgA in about 70% of Japanese adults is considered as being suggestive of a history of influenza infection. The presence of anti-influenza virus-specific IgG in the serum in almost all Japanese adults could suggest a history of influenza infection or influenza vaccination. Currently available subcutaneous influenza vaccines induce systemic immunity, with the appearance of anti-viral IgG in the serum, in adults. However, subcutaneous vaccination does not appear to be capable of inducing mucosal immunity with the induction of antiviral secretory IgA in the nasopharynx. The present findings suggest that subcutaneous influenza vaccination can suppress the progression of influenza infection by inducing the appearance of antiviral IgG in serum, but not by inducing the appearance of antiviral IgA in the nasopharynx. The findings also suggest that subjects with low antiviral secretory IgA titers in the nasopharynx are at a higher risk of influenza infection.

　The diagnostic criteria for Persistent Postural-Perceptual Dizziness (PPPD) was defined by the Committee for the Classification of Vestibular Disorders of the Barany Society, and published in the Journal of Vestibular Research in 2017. PPPD is characterized by chronic vestibular syndrome persisting for >3 months, that is typically preceded by acute vestibular disorders. Antidepressant medication, vestibular rehabilitation, and cognitive behavioral therapy have been reported to be useful for the treatment of PPPD. In this study, we evaluated the efficacy of pharmacotherapy with antidepressants in 90 patients diagnosed as having PPPD. A selective serotonin reuptake inhibitor (SSRI)(escitalopram, 10-20mg/day), serotonin and noradrenaline reuptake inhibitor (SNRI)(venlafaxine, 75mg/day), and noradrenergic and specific serotonergic antidepressant (NaSSA)(mirtazapine, 15mg/day) were used in this study. Antidepressant therapy led to improvement of the Dizziness Handicap Inventory (DHI) score, suggesting that it was effective for reducing the dizziness in patients with PPPD. On the other hand, in the non-treated group, consisting of patients who, for some reason, could not receive medication, there was no significant improvement in dizziness during the approximately 1-year follow-up period, suggesting the usefulness of therapeutic intervention for PPPD. While antidepressant drug therapy was shown to be effective, the incidence of adverse effects was high for all the drug classes, and the treatment continuation rate tended to decrease as the incidence of adverse effects increased, suggesting that appropriate control of adverse effects is important to achieve better treatment efficacy.

　Dizziness is the one of the major complaints encountered in medical emergency rooms, and sometimes, the cause of the dizziness may be life-threating and/or result in serious sequelae. We analyzed the data of the patients with acute dizziness who were brought by emergency transportation to out hospital. We provided clinical information about these patients to the resident doctors and conducted a questionnaire survey of the resident doctors to enquire about their general practice for cases of acute dizziness. A total 224 patients with acute dizziness patients referred to our hospital were enrolled in this study. We studied the patient's background, symptoms associated with dizziness, and diagnosis in the hospitalized cases. A questionnaire on acute dizziness care was administered before and after the lecture on acute dizziness care. Among the 224 patients transported to our hospital for acute dizziness, 93 (41.5%) required hospitalization. Thirty-eight patients were hospitalized for peripheral dizziness, 29 for central dizziness, 15 for other systemic diseases, and 11 for unknown causes. The questionnaire survey of 42 resident doctors indicated that the majority were interested in acute dizziness care, but felt that they did not have sufficient knowledge on acute dizziness. We consider that appropriate diagnostic skill to differentiate among the different causes of dizziness is mandatory in acute dizziness care. We were able to share information about acute vertigo care by providing feedback from the results of this study to the resident doctors and emergency physicians.

　We conducted a retrospective analysis of the data, obtained from the medical records, of 210 patients with peritonsillar abscesses treated at our hospital between May 2017 and July 2020. There were 157 men and 53 women, with a median age of 37 years. The right side was affected in 49.5%, the left side in 49.5%, and both sides in 1% of the cases. The average duration of hospitalization was 5.8 days. The abscess site was of the superior type in 177 cases and of the inferior type in 33 cases. History of tonsillitis, smoking, and diabetes mellitus was present in 34.8%, 49.5%, and 2.9% of the patients, respectively. Incision and drainage was used for the treatment in 94.8% of the patients. The condition relapsed in only 11 patients (5.2%). Bacteriological analysis led to the isolation of anaerobes as the causative bacteria in 79 (57.3%) of the 138 patients. The most frequently isolated aerobic and anaerobic bacteria were α-hemolytic streptococci and Fusobacterium, respectively. We also analyzed the following 12 clinical factors in relation to the duration of hospitalization: age; sex; body mass index; duration of symptoms; history of diabetes mellitus, tonsillitis, and smoking; presence/absence of trismus; presence/absence of laryngeal edema; abscess site; serum white blood cell count; serum C-reactive protein level. The results showed that the duration of hospitalization was significantly longer in patients with the inferior type of abscess than in those with the superior type, and also longer in the patients with laryngeal edema than in those without. However, multivariate analysis identified the abscess site (superior/inferior aspect of the tonsil) as the sole variable associated with the duration of hospitalization. The relatively low recurrence rate in our study could possibly be attributed to the repeated incision and drainage sessions undertaken by us. However, the procedure needs to be meticulous, especially in the cases with inferior type. When a peritonsillar abscess is suspected to be of the inferior type, contrast-enhanced computed tomography can provide valuable information for accurate diagnosis and also enable appropriate treatment decisions to be made.

　The side effects of sublingual immunotherapy (SLIT) are mainly local allergic reactions, such as itching and mucosal swelling in the oral cavity, due to allergen exposure. Most patients have mild symptoms and do not require treatment. Herein, I report the case of a 37-year-old man who had no side effects during the up-dosing phase of house dust mite (HDM) SLIT, but experienced itching and swelling of the sublingual area on the first day of the maintenance phase. Two weeks later, the patient developed herpes simplex virus (HSV) infection of the sublingual mucosa. Following the start of treatment with an anti-HSV drug, the sublingual lesions gradually improved, and by 22 days after the onset, the lesions had healed completely, without leaving any after-effects. After conducting a review of the literature on the mechanism of onset of HSV infection, I concluded that this infection in my patient may have resulted from (1) reduced barrier function of the mucosal epithelium due to oral mucosal swelling and HDM protease activity, and (2) inadequate antiviral response due to reduced interferon-α-producing capacity of the plasmacytoid dendritic cells of the oral mucosa because of the HDM-SLIT. It is thus necessary to carefully monitor patients receiving HDM-SLIT for oral mucosal swelling so as to detect HSV infection early.